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Gallic acid (GA) has a good therapeutic effect in bacteriological inhibition and plays a variety of functions in maintaining the stability of the immune system. The aim of the present study was to investigate the effect of GA on the bactericidal activity of macrophages against Vibrio vulnificus (Vv). A cell counting kit-8 (CCK-8) assay was carried out to test the cytotoxicity of GA on J774A.1 cells. Concentration of proinflammatory cytokines in J774A.1 cells were evaluated by ELISA. The internalization and degradation of Vv in the phagosomes were observed by transmission electron microscopy (TEM). The phagosome acidification and phagolysosome formation were detected to evaluate the bacteria-clearing function of J774A.1 cells. The bactericidal activity of GA in vivo was also investigated by collecting the survival time of Vv infected mice and observing the inflammatory infiltration of organs. Our results demonstrated that GA at 50 μM significantly inhibited the proinflammatory cytokines levels, promoted phagosome acidification and phagolysosome formation in J774A.1 cells with Vv infection. This may be related to the activation of NLRP3/mTOR signaling pathway. Additionally, GA treatment improves the survival and bactericidal activity of mice infected with Vv. In summary, GA exerts bactericidal activity against Vv infection by regulating the formation and acidification of phagocytic lysosomes in macrophages. [ABSTRACT FROM AUTHOR]

The current model for the insulin system focuses excessively on the interplay between insulin and blood glucose, and could be called a 'glucosestat'. The response of insulin to feeding is mainly governed by the glucoincretin effect, which depends on the secretion of glucoincretins, which is not specific to glucose. The insulin system during fasting is governed by the adipoincretin effect, which operates as a feedback control system governed by adipocyte phosphoinositide-3 kinase (PI3K) signaling. Under fasting conditions, the insulin system behaves as a 'cruise control' system for lipolysis, which can be described as an 'adipostat'. The current paradigm for the insulin system focuses on the phenomenon of glucose-stimulated insulin secretion and insulin action on blood glucose control. This historical glucose-centric perspective may have introduced a conceptual bias in our understanding of insulin regulation. A body of evidence demonstrating that in vivo variations in blood glucose and insulin secretion can be largely dissociated motivated us to reconsider the fundamental design of the insulin system as a control system for metabolic homeostasis. Here, we propose that a minimal glucose-centric model does not accurately describe the physiological behavior of the insulin system and propose a new paradigm focusing on the effects of incretins, arguing that under fasting conditions, insulin is regulated by an adipoincretin effect. The current paradigm for the insulin system focuses on the phenomenon of glucose-stimulated insulin secretion and insulin action on blood glucose control. This historical glucose-centric perspective may have introduced a conceptual bias in our understanding of insulin regulation. A body of evidence demonstrating that in vivo variations in blood glucose and insulin secretion can be largely dissociated motivated us to reconsider the fundamental design of the insulin system as a control system for metabolic homeostasis. Here, we propose that a minimal glucose-centric model does not accurately describe the physiological behavior of the insulin system and propose a new paradigm focusing on the effects of incretin, arguing that under fasting conditions, insulin is regulated by an adipoincretin effect. [ABSTRACT FROM AUTHOR]

• EA improves cognitive function in MCAO rats. • EA reduces inflammation and autophagy in MCAO rats. • EA upregulates miR-135a-5p to inhibit autophagy in MCAO rats. • MiR-135a-5p targets mTOR/NLRP3 axis to repress autophagy. Post-stroke cognitive impairment is a significant challenge with limited treatment options. Electroacupuncture (EA) has shown promise in improving cognitive function after stroke. Our study explores the underlying mechanism of EA in alleviating cognitive impairment through the inhibition of autophagy. We utilized a rat model of stroke induced by middle cerebral artery occlusion (MCAO) to evaluate the efficacy of EA. Treatment with EA was observed to markedly improve cognitive function and reduce inflammation in MCAO rats, as evidenced by decreased neurological deficit scores, shorter latencies in the water maze test, and diminished infarct volumes. EA also attenuated tissue damage in the hippocampus and lowered the levels of pro-inflammatory cytokines and oxidative stress markers. Although autophagy was upregulated in MCAO rats, EA treatment suppressed this process, indicated by a reduction in autophagosome formation and alteration of autophagy-related protein expression. The protective effects of EA were reversed by the autophagy activator rapamycin. EA treatment elevated the levels of microRNA (miR)-135a-5p expression, and suppression of this elevation attenuated the remedial efficacy of EA in addressing cognitive impairment and inflammation. MiR-135a-5p targeted mammalian target of rapamycin (mTOR)/NOD-like receptor protein 3 (NLRP3) signaling to repress autophagy. EA treatment inhibits autophagy and alleviates cognitive impairment in post-stroke rats. It exerts its beneficial effects by upregulating miR-135a-5p and targeting the mTOR/NLRP3 axis. [ABSTRACT FROM AUTHOR]

Metabolic reprogramming of vascular smooth muscle cell (VSMC) plays a critical role in the pathogenesis of thoracic aortic dissection (TAD). Previous researches have mainly focused on dysregulation of fatty acid or glucose metabolism, while the impact of amino acids catabolic disorder in VSMCs during the development of TAD remains elusive. Here, we identified branched-chain amino acid (BCAA) catabolic defect as a metabolic hallmark of TAD. The bioinformatics analysis and data from human aorta revealed impaired BCAA catabolism in TAD individuals. This was accompanied by upregulated branched-chain α-ketoacid dehydrogenase kinase (BCKDK) expression and BCKD E1 subunit alpha (BCKDHA) phosphorylation, enhanced vascular inflammation, and hyperactivation of mTOR signaling. Further in vivo experiments demonstrated that inhibition of BCKDK with BT2 (a BCKDK allosteric inhibitor) treatment dephosphorylated BCKDHA and re-activated BCAA catabolism, attenuated VSMCs phenotypic switching, alleviated aortic remodeling, mitochondrial reactive oxygen species (ROS) damage and vascular inflammation. Additionally, the beneficial actions of BT2 were validated in a TNF-α challenged murine VSMC cell line. Meanwhile, rapamycin conferred similar beneficial effects against VSMC phenotypic switching, cellular ROS damage as well as inflammatory response. However, co-treatment with MHY1485 (a classic mTOR activator) reversed the beneficial effects of BT2 by reactivating mTOR signaling. Taken together, the in vivo and in vitro evidence showed that impairment of BCAA catabolism resulted in aortic accumulation of BCAA and further caused VSMC phenotypic switching, mitochondrial ROS damage and inflammatory response via mTOR hyperactivation. BCKDK and mTOR signaling may serve as the potential drug targets for the prevention and treatment of TAD. [Display omitted] • Aortic BCAA catabolic defect is a previously unrecognized contributor to the pathogenesis of TAD. • Aortic BCAA catabolic defect results from the inhibitory phosphorylation of BCKDHA by BCKDK. • Aortic BCAA catabolic defect induced VSMC phenotypic switching and inflammatory response via mTOR hyperactivation. • BCKDK and mTOR signaling may serve as the potential drug targets for the treatment of TAD. [ABSTRACT FROM AUTHOR]

Background: Genetic variations in Sestrin2/Sestrin3/mTOR axis may cause obesity-associated metabolic syndrome, including lipid accumulation and insulin resistance thereby increasing individual's risk of diabetes. In this study, we explored the association between single nucleotide polymorphisms (SNPs) of these genes and new onset diabetes after transplantation in Hispanic renal transplant recipients (RTRs). Methods: Nine potential functional polymorphisms in Sestrin2. Sestrin3 and mTOR genes were genotyped using the Taqman qPCR method in this study. We compared 160 Hispanic RTRs with no evidence of pre-existing diabetes, who developed new onset diabetes after transplantation (NODAT) with 152 controls with no history of diabetes. The logistic proportional hazard model was used to examine risks for NODAT. Nongenetic and genetic characteristics were included in the multivariate risk model. Results: Significant associations were observed between NODAT and mTOR TT (rs2295080 OR = 1.79, 95% Cl = 1.14-2.82, p = 0.01), Sestrin2 AA (rs580800, OR = 0.42, 95% Cl =0.27-0.67, p = 0.002), and Sestrin3 AA (rs684856, OR = 0.45, 95% CI = 0.27-0.75, p = 0.001). Sestrin2 AA (rs580800), Sestrin3 AA (rs684856) and mTOR TT (rs2295080) remained significantly associated with NODAT after adjusting for acute rejection and sirolimus use. No interactions observed between the mTOR rs2295080 and Sestrin3 rs684856 and risk of NODAT (mTOR rs2295080 and Sestrin3 rs684856, p 0.123 and mTOR rs2295080 and Sestrin2 rs580800, p 0.167). Of the nongenetic factors, use of sirolimus and older age were associated with an increased risk for NODAT. Conclusion: Polymorphisms in the Sestrin2/Scstrin3/mTOR gene may confer certain protection/predisposition for NODAT. [ABSTRACT FROM AUTHOR]

One of the central regulators of cell growth, proliferation, and metabolism is the mammalian target of rapamycin, mTOR, which exists in two structurally and functionally different complexes: mTORC1 and mTORC2; unlike m TORC2, mTORC1 is activated in response to the sufficiency of nutrients and is inhibited by rapamycin. mTOR complexes have critical roles not only in protein synthesis, gene transcription regulation, proliferation, tumor metabolism, but also in the regulation of the programmed cell death mechanisms such as autophagy and apoptosis. Autophagy is a conserved catabolic mechanism in which damaged molecules are recycled in response to nutrient starvation. Emerging evidence indicates that the mTOR signaling pathway is frequently activated in tumors. In addition, dysregulation of autophagy was associated with the development of a variety of human diseases, such as cancer and aging. Since mTOR can inhibit the induction of the autophagic process from the early stages of autophagosome formation to the late stage of lysosome degradation, the use of mTOR inhibitors to regulate autophagy could be considered a potential therapeutic option. The present review sheds light on the mTOR and autophagy signaling pathways and the mechanisms of regulation of mTOR-autophagy. [ABSTRACT FROM AUTHOR]

As a p53-regulated gene, Wip1 regulates proliferation, migration, apoptosis, and senescence of several type cells, but its biological functions in keratinocytes and endothelial cells which are involved wound healing are not fully understood. This study aims to reveal the function and underlying mechanism of Wip1 in wound healing using models of transgenic animal, keratinocytes, and endothelial cells. Using Wip1 knockout C57 BL/6 mice, we investigated effect of Wip1 deficiency on wound healing and angiogenesis; And using HaCaT and HUVEC as keratinocytes and endothelial cells, combined using primary keratinocytes from Wip1 knockout mice, we studied the effects of Wip1 knockdown/knockout or overexpression on proliferation, migration, and protein expressions of signaling components in ATM-p53 and mTOR pathway. Wip1 deficiency in mice impaired the wound repair and endothelial angiogenesis, reduced the thickness of granulation tissue, and decreased the number of Ki67-positive cells and CD31 positive vessels in granulation tissue. Knockdown of Wip1 by shRNAs suppressed the proliferation and migration of HaCaT and HUVEC cells and induced notably apoptosis in the two cells. In western blot, Wip1 knockdown enriched p53 and ATM proteins, while decreased activated AKT, mTOR and activated S6 ribosomal protein (pS6) levels in HaCaT and HUVEC cells. Ectopic expression of Wip1 decreased the p53 and ATM proteins, while increased activated AKT, mTOR and pS6 levels in HaCaT and HUVEC cells. And in primary keratinocytes from mice tail skin, Wip1 knockout increased p53 and ATM, while decreased activated AKT, mTOR and pS6 protein levels. Our study directly supports that Wip1 regulated skin wound healing possibly by affecting bioactivities including proliferation, migration and apoptosis of keratinocytes and endothelial cells at least through by modulating ATM-p53 and mTOR signaling. • Wip1 participated in mice wound repair and endothelial angiogenesis. • Wip1 regulated thickness of granulation tissue and the number of Ki67-positive cells and CD31 positive vessels in granulation tissue. • Wip1 affected the proliferation, migration and apoptosis of keratinocytes and endothelial cells by modulating ATM-p53 and mTOR signaling. [ABSTRACT FROM AUTHOR]

Although genetic causes of drug-resistant focal epilepsy and selected focal malformations of cortical development (MCD) have been described, a limited number of studies comprehensively analysed genetic diagnoses in patients undergoing pre-surgical evaluation, their outcomes and the effect of genetic diagnosis on surgical strategy. We analysed a prospective cohort of children enrolled in epilepsy surgery program over January 2018–July 2022. The majority of patients underwent germline and/or somatic genetic testing. We searched for predictors of surgical outcome and positive result of germline genetic testing. Ninety-five patients were enrolled in epilepsy surgery program and 64 underwent resective epilepsy surgery. We ascertained germline genetic diagnosis in 13/74 patients having underwent germline gene testing (pathogenic or likely pathogenic variants in CHRNA4, NPRL3, DEPDC5, FGF12, GRIA2, SZT2, STXBP1) and identified three copy number variants. Thirty-five patients underwent somatic gene testing; we detected 10 pathogenic or likely pathogenic variants in genes SLC35A2, PTEN, MTOR, DEPDC5, NPRL3. Germline genetic diagnosis was significantly associated with the diagnosis of focal epilepsy with unknown seizure onset. Germline and somatic gene testing can ascertain a definite genetic diagnosis in a significant subgroup of patients in epilepsy surgery programs. Diagnosis of focal genetic epilepsy may tip the scales against the decision to proceed with invasive EEG study or surgical resection; however, selected patients with genetic focal epilepsies associated with MCD may benefit from resective epilepsy surgery and therefore, a genetic diagnosis does not disqualify patients from presurgical evaluation and epilepsy surgery. • Germline and somatic gene testing can ascertain genetic diagnosis in patients enrolled in epilepsy surgery programs. • Patients with focal genetic DRE not amenable for resective procedures represent an important subgroup of patients enrolled in presurgical evaluation. • Diagnosis of focal genetic DRE without MCD may reverse the decision to proceed with invasive EEG study or resection. • Selected patients with genetic focal epilepsies associated with MCD may benefit from resective epilepsy surgery. [ABSTRACT FROM AUTHOR]

[Display omitted] • MAF1 is a novel intrinsic inhibitor of spontaneous recovery after ischemic stroke. • MAF1 is upregulated and activated in neurons of peri-infarct cortex in the cerebral hemisphere. • In addition to Pol III, MAF1 represses Pol II-transcribed CREB-related genes. • MAF1 knockdown markedly enhances global protein synthetic capacity and CREB-mediated neural repair in peri-infarct cortex. • Targeting MAF1 could potentiate neural plasticity and functional recovery after ischemic stroke and other CNS injuries. Spontaneous recovery after CNS injury is often very limited and incomplete, leaving most stroke patients with permanent disability. Maf1 is known as a key growth suppressor in proliferating cells. However, its role in neuronal cells after stroke remains unclear. We aimed to investigate the mechanistic role of Maf1 in spontaneous neural repair and evaluated the therapeutic effect of targeting Maf1 on stroke recovery. We used mouse primary neurons to determine the signaling mechanism of Maf1, and the cleavage-under-targets-and-tagmentation-sequencing to map the whole-genome promoter binding sites of Maf1 in isolated mature cortical neurons. Photothrombotic stroke model was used to determine the therapeutic effect on neural repair and functional recovery by AAV-mediated Maf1 knockdown. We found that Maf1 mediates mTOR signaling to regulate RNA polymerase III (Pol III)-dependent rRNA and tRNA transcription in mouse cortical neurons. mTOR regulates neuronal Maf1 phosphorylation and subcellular localization. Maf1 knockdown significantly increases Pol III transcription, neurite outgrowth and dendritic spine formation in neurons. Conversely, Maf1 overexpression suppresses such activities. In response to photothrombotic stroke in mice, Maf1 expression is increased and accumulates in the nucleus of neurons in the peripheral region of infarcted cortex, which is the key region for neural remodeling and repair during spontaneous recovery. Intriguingly, Maf1 knockdown in the peri-infarct cortex significantly enhances neural plasticity and functional recovery. Mechanistically, Maf1 not only interacts with the promoters and represses Pol III-transcribed genes, but also those of CREB-associated genes that are critical for promoting plasticity during neurodevelopment and neural repair. These findings indicate Maf1 as an intrinsic neural repair suppressor against regenerative capability of mature CNS neurons, and suggest that Maf1 is a potential therapeutic target for enhancing functional recovery after ischemic stroke and other CNS injuries. [ABSTRACT FROM AUTHOR]

Post-traumatic stress disorder (PTSD) is a mental illness caused by either experiencing or observing a traumatic event that is perceived to pose a serious risk to one's life. (2 R ,6 R)-HNK has an alleviating effect on negative emotions, nevertheless, the mechanism of (2 R ,6 R)-HNK action is unclear. In this study, the single prolonged stress and electric foot shock (SPS&S) method was used to establish a rat model of PTSD. After determining the validity of the model, (2 R ,6 R)-HNK was administered to the NAc by microinjection using a concentration gradient of 10, 50, and 100 μM, and the effects of the drug in the SPS&S rat model were evaluated. Moreover, our study measured changes in related proteins in the NAc (BDNF, p-mTOR/mTOR, and PSD95) and synaptic ultrastructure. In the SPS&S group, the protein expression of brain-derived neurotrophic factor (BDNF), mammalian target of rapamycin (mTOR), and PSD95 was reduced and synaptic morphology was damaged in the NAc. In contrast, after the administration of 50 μM (2 R ,6 R)-HNK, SPS&S-treated rats improved their exploration and depression-linked behavior, while protein levels and synaptic ultrastructure were also restored in the NAc. With the administration of 100 μM (2 R ,6 R)-HNK, locomotor behavior, and social interaction improved in the PTSD model. The mechanism of BDNF-mTOR signaling after (2 R ,6 R)-HNK administration was not explored. (2 R ,6 R)-HNK may ameliorate negative mood and social avoidance symptoms in PTSD rats by regulating BDNF/mTOR-mediated synaptic structural plasticity in the NAc, providing new targets for the development of anti-PTSD drugs. • The nucleus accumbens is a component of protecting against or alleviating PTSD. • (2 R ,6 R)-hydroxynorketamine relieves various PTSD symptoms at different concentrations. • BDNF-mTOR pathway in NAc as a therapeutic target of therapeutic efficacy for PTSD [ABSTRACT FROM AUTHOR]

Mechanistic target of rapamycin (mTOR), a highly conserved serine/threonine kinase, is involved in cellular metabolism, protein synthesis, and cell death. Programmed cell death (PCD) assists in eliminating aging, damaged, or neoplastic cells, and is indispensable for sustaining normal growth, fighting pathogenic microorganisms, and maintaining body homeostasis. mTOR has crucial functions in the intricate signaling pathway network of multiple forms of PCD. mTOR can inhibit autophagy, which is part of PCD regulation. Cell survival is affected by mTOR through autophagy to control reactive oxygen species production and the degradation of pertinent proteins. Additionally, mTOR can regulate PCD in an autophagy-independent manner by affecting the expression levels of related genes and phosphorylating proteins. Therefore, mTOR acts through both autophagy-dependent and -independent pathways to regulate PCD. It is conceivable that mTOR exerts bidirectional regulation of PCD, such as ferroptosis, according to the complexity of signaling pathway networks, but the underlying mechanisms have not been fully explained. This review summarizes the recent advances in understanding mTOR-mediated regulatory mechanisms in PCD. Rigorous investigations into PCD-related signaling pathways have provided prospective therapeutic targets that may be clinically beneficial for treating various diseases. [Display omitted] • A summary of various mechanisms of mTOR inhibiting autophagy. • Autophagy serving as a bridge between mTOR and programmed cell death. • mTOR regulating programmed cell death through autophagy-independent mechanisms. • Therapeutic advances applying mechanisms of mTOR regulating programmed cell death. [ABSTRACT FROM AUTHOR]

• The m6A methyltransferase Mettl14 is involved in the generation of in vitro-induced Tregs (iTregs). • The methyltransferase Mettl14 is necessary for the maintenance of functional iTregs. • Mettl14-mediated m6A modification disrupted iTregs polarization by activating the mTOR-dependent pathway. • Our findings revealed that Mettl14 as a positive regulator has great relevance for improving the iTregs stability and function. Induced regulatory T cell (iTregs) can be generated in vitro. Thus, iTregs-based therapeutics are receiving increased attention for their potential to treat autoimmune diseases and prevent transplant rejection. However, iTregs fail to maintain FoxP3 expression and suppressive activity, which limits their clinical application. Increasing lines of evidence suggest that methyltransferase-like 14 (METTL14), a critical component of the m6A writer complex, regulates the stability and function of the Treg cells. However, beyond meeting the epigenetic modification of Treg cells, whether Mettl14 plays a role in the fate determination of iTregs is unclear. Here, we systemically investigated the potential function of METTL14 in iTregs differentiation and regulatory activity. In our study, iTregs were generated from CD4+ naïve T cells under iTreg-polarizing conditions, we found that the expression of METTL14 was increased in iTregs compared with CD4+naïve T cells. Subsequently, the expression of METTL14 was knocked down by siRNA-METTL14 interference in CD4+ naïve T cells and cultured under iTreg-polarizing conditions. According to the results, Mettl14 deficiency resulted in the disruption of iTregs differentiation evidenced by the limited FoxP3 expression. Meanwhile, inflammatory cytokines such as IFN-γ and IL-17a were upregulated in cultured iTregs. We next determined the functional change in METTL14-deficient iTregs. The results of the colitis development in Rag1 −/− mice and CFSE assays revealed that loss of METTL14 significantly compromised the suppressive function of iTregs in vivo and in vitro. We further checked the altered signaling pathway in METTL14-deficient iTregs. We found that reduced METTL14 leads to activation of the mTOR pathway with increased p-mTOR and p-p70S6K, which are known to modulate the suppressive function of iTregs. In conclusion, our study revealed that Mettl14 plays a critical role in the development and suppressive function of iTregs in vitro and could thus serve as a regulatory element for stabilizing iTregs in cell-based therapy. [ABSTRACT FROM AUTHOR]

Statins have been reported to have potential anti-proliferative effects through an unknown mechanism. This study aims to investigate the anti-proliferative activities of five statins, including simvastatin, rosuvastatin, fluvastatin, atorvastatin, and pravastatin, against five different cancer cell lines; cervical epithelial carcinoma DoTc2 4510, malignant melanoma A-375, muscle Ewing's sarcoma A-673, hepatocellular carcinoma HUH-7, as well as breast cancer cells MCF-7. At 100 µM, simvastatin and atorvastatin significantly inhibited 70% of cellular proliferation. At the same concentration, rosuvastatin and fluvastatin showed about 50% of inhibition only in A-375 and A-673 cancer cells in a time- and dose-dependent manner. Of all the statin drugs used, pravastatin had the least inhibitory effect on all the cancer cell lines. Western Blot analysis showed a decrease in mTOR level, and the expression of p53 tumour suppression and BCL-2 proteins was relatively elevated compared to the untreated cells. Simvastatin and atorvastatin may inhibit cellular proliferation via BCL-2/p53, Bax/Bak, and PI3K/Akt/mTOR signalling pathways. This is the first research to evaluate the anti-cancer effects of simvastatin, rosuvastatin, fluvastatin, atorvastatin, and pravastatin against five different cell lines from distinct origins and provided a relevant comparison of their efficacies for their anti-proliferative activity. [ABSTRACT FROM AUTHOR]

Mammalian target of rapamycin complex 1 (mTORC1) plays a crucial role in cellular physiology. Amino acids lead to mTORC1 lysosomal translocation where it is activated by growth factors via Rheb. Phospholipase D (PLD) and its lipid metabolite phosphatidic acid (PA) are required for both amino acid and growth factor input to mTORC1. PA induces mTORC1 lysosomal translocation and activation in the absence of amino acids, Rag GTPases, growth factors, and Rheb. We review recent structural findings and propose that PA binds to a highly conserved sequence on the α4 helix of the FK506 binding protein 12 (FKB12)/rapamycin-binding (FRB) domain of mTOR. Crucially, by binding to two adjacent positively charged amino acids, PA disrupts the helix, with consequences for substrate binding and catalytic activity. Disruption of the α4 helix by PA allows binding of S6K to the FRB domain, but not of PRAS40 or rapamycin. It also induces FRB conformational changes that allow mTORC1 catalytic activity in the absence of Rheb. mTORC1, the mammalian target of rapamycin complex 1, is a key regulator of cellular physiology. The lipid metabolite phosphatidic acid (PA) binds to and activates mTORC1 in response to nutrients and growth factors. We review structural findings and propose a model for PA activation of mTORC1. PA binds to a highly conserved sequence in the α4 helix of the FK506 binding protein 12 (FKBP12)/rapamycin-binding (FRB) domain of mTOR. It is proposed that PA binding to two adjacent positively charged amino acids breaks and shortens the C-terminal region of helix α4. This has profound consequences for both substrate binding and the catalytic activity of mTORC1. [ABSTRACT FROM AUTHOR]

Th17-polarized CD4+ effector T-cells together with their immunosuppressive regulatory T-cell (Treg) counterparts, with transcriptional profiles governed by the lineage transcription factors RORγt/RORC2 and FOXP3, respectively, are important gatekeepers at mucosal interfaces. Alterations in the Th17/Treg ratios, due to the rapid depletion of Th17 cells and increased Treg frequencies, are a hallmark of both HIV and SIV infections and a marker of disease progression. The shift in Th17/Treg balance, in favor of increased Treg frequencies, contributes to gut mucosal permeability, immune dysfunction, and microbial translocation, subsequently leading to chronic immune activation/inflammation and disease progression. Of particular interest, Th17 cells and Tregs share developmental routes, with changes in the Th17 versus Treg fate decision influencing the pro-inflammatory versus anti-inflammatory responses. The differentiation and function of Th17 cells and Tregs rely on independent yet complementary metabolic pathways. Several pathways have been described in the literature to be involved in Th17 versus Treg polarization, including 1) the activity of ectonucleotidases CD39/CD73; 2) the increase in TGF-β1 production; 3) a hypoxic environment, and subsequent upregulation in hypoxia-inducible factor-1α (HIF-1α); 4) the increased mTOR activity and glycolysis induction; 5) the lipid metabolism, including fatty acid synthesis, fatty acids oxidation, cholesterol synthesis, and lipid storage, which are regulated by the AMPK, mevalonate and PPARγ pathways; and 6) the tryptophan catabolism. These metabolic pathways are understudied in the context of HIV-1 infection. The purpose of this review is to summarize the current knowledge on metabolic pathways that are dysregulated during HIV-1 infection and their impact on Th17/Treg balance. [Display omitted] • HIV infection shifts the Th17/Treg imbalance in favor of Tregs, contributing to chronic immune dysfunction. • Th17 cells and Tregs share developmental routes regulated by their metabolism and microenvironment. • HIV infection upregulates mTOR, glycolysis, fatty acid synthesis and HIF-1α, related to Th17 cell differentiation. • HIV infection upregulates TGF-β1, purinergic and Kynurenine pathways, in favor of Tregs differentiation. • HIV infection downregulates AMKP, mevalonate pathway and PPAR-γ activity, which are related to Treg differentiation. [ABSTRACT FROM AUTHOR]

Treatment resistance often occurs with BRAF inhibitor (BRAFi) therapy for melanoma, bringing in a great challenge to the treatment of melanoma patients harboring mutant BRAF gene. Recent studies revealed redox vulnerability constitutes a novel opportunity to overcome BRAFi resistance. Previously we found Sestrin2 provided protection to metastatic melanoma cells by detoxifying reactive oxygen species (ROS) induced by anoikis, but its defensive role against redox stimuli elicited by BRAFi was unclear. In-depth explored the role of Sestrin2 in BRAFi-resistant melanoma. Vemurafenib-resistant melanoma cells were established using 451Lu and UACC62 cell lines carrying BRAFV600E mutation. Mechanistic studies were subsequently performed by transfection of lentiviral vectors encoding an shRNA against SESN2 or embedded with the coding sequences of SESN2 cDNA. Elevated Sestrin2 expression was found in vemurafenib-resistance melanoma cells. Further mechanistic studies revealed that BRAFi-resistant melanoma cells employ Sestrin2 to adapt to higher oxidative stress under vemurafenib exposure. It was also demonstrated that mTOR signaling was significantly activated following Sestrin2 knockdown. Given the known promoting role of active mTOR signaling in melanoma proliferation and survival, the effects of mTOR blocker and Sestrin2 ablation on BRAFi-resistant melanoma cells were further tested, and the combination was found to result in enhanced inhibition of melanoma cell growth. Our findings demonstrated the contribution of Sestrin2 to the development of BRAFi resistance and the fact that the combination of mTOR blocker assisted Sestrein2 ablation in eliminating BRAFi resistance of melanoma. Therefore, mTOR and Sestrin2 may be novel combinatorial therapeutic targets to overcome BRAFi resistance of melanoma. • BRAFi resistant melanoma cells experienced significant increased level of Sestrin2, gaining protection from reactive oxidative stress (ROS)- induced cell death under BRAFi exposure. • The activity of mTOR signaling elevated following Sestrin2 ablation. • The combination of mTOR blocker and Sestrin2 knockdown generated enhanced growth suppression effects on BRAFi-resistant melanoma cells. [ABSTRACT FROM AUTHOR]

Vorolanib is a highly potent tyrosine kinase inhibitor (TKI) targeting vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor. This three-arm, randomised, registered study aimed to assess the combination of vorolanib and everolimus or vorolanib alone versus a control arm of everolimus as second-line treatment in patients with metastatic renal cell carcinoma (RCC). Patients with advanced or metastatic RCC who had received one prior VEGFR-TKI were randomised (1:1:1) to receive the combination of vorolanib and everolimus or either monotherapy. Patients with brain metastases were excluded. The primary end-point was progression-free survival (PFS) assessed by the independent review committee per Response Evaluation Criteria in Solid Tumours v1.1. Between 10th March 2017 and 30th May 2019, 399 patients (133 in each group) were enrolled. By the cutoff date (30th April 2020), a significant improvement in PFS was detected in the combination group compared with the everolimus group (10.0 versus 6.4 months; hazard ratio, 0.70; P = 0.0171). PFS was similar between the vorolanib group and the everolimus group (median: 6.4 versus 6.4 months; hazard ratio, 0.94; P = 0.6856). A significantly higher objective response rate was observed in the combination group than in the everolimus group (24.8% versus 8.3%; P = 0.0003), whereas there was no significant difference between the vorolanib group and the everolimus group (10.5% versus 8.3%; P = 0.5278). The overall survival data were immature. A total of 96 (72.2%), 52 (39.1%) and 71 (53.4%) grade 3 or higher treatment-related adverse events occurred in the combination group, vorolanib group and everolimus group, respectively. The addition of vorolanib to everolimus as 2nd-line treatment for patients with advanced or metastatic RCC who have experienced cancer progression after VEGFR-TKI therapy provided a better objective response rate and PFS than everolimus alone with a manageable safety profile. ClinicalTrials.gov, NCT03095040 ; Chinadrugtrials, CTR20160987. • The combination of vorolanib and everolimus showed promising efficacy. • Vorolanib plus everolimus was well-tolerated with manageable safety profile. • This study provided a new option for previously treated patients with metastatic renal cell carcinoma. [ABSTRACT FROM AUTHOR]

Arrhythmogenic cardiomyopathy (ACM), a fatal heart disease characterized by fibroadipocytic replacement of cardiac myocytes, accounts for 20% of sudden cardiac death and lacks effective treatment. It is often caused by mutations in desmosome proteins, with Desmoglein-2 (DSG2) mutations as a common etiology. However, the mechanism underlying the accumulation of fibrofatty in ACM remains unknown, which impedes the development of curative treatment. Here we investigated the fat accumulation and the underlying mechanism in a mouse model of ACM induced by cardiac-specific knockout of Dsg2 (CS- Dsg2 −/−). Heart failure and cardiac lipid accumulation were observed in CS- Dsg2 −/− mice. We demonstrated that these phenotypes were caused by decline of fatty acid (FA) β -oxidation resulted from impaired mammalian target of rapamycin (mTOR) signaling. Rapamycin worsened while overexpression of mTOR and 4EBP1 rescued the FA β -oxidation pathway in CS- Dsg2 −/− mice. Reactivation of PPAR α by fenofibrate or AAV9- Pparα significantly alleviated the lipid accumulation and restored cardiac function. Our results suggest that impaired mTOR–4EBP1–PPAR α -dependent FA β -oxidation contributes to myocardial lipid accumulation in ACM and PPAR α may be a potential target for curative treatment of ACM. Deletion of Dsg2 in cardiomyocytes leads to downregulation of the mTOR–4EBP1–PPAR α signaling pathway, resulting in impaired fatty acid β -oxidation pathway and the development of arrhythmogenic cardiomyopathy. [Display omitted] [ABSTRACT FROM AUTHOR]

Nitrous oxide (N 2 O) is a noncompetitive inhibitor of NMDA receptors that appears to have ketamine-like rapid antidepressant effects in patients with treatment-resistant major depression. In preclinical studies, ketamine enhances glutamate-mediated synaptic transmission in the hippocampus and prefrontal cortex. In this study, we examined the effects of N 2 O on glutamate transmission in the hippocampus and compared its effects to those of ketamine. Glutamate-mediated synaptic transmission was studied in the CA1 region of hippocampal slices from adult albino rats using standard extracellular recording methods. Effects of N 2 O and ketamine at subanesthetic concentrations were evaluated by acute administration. Akin to 1 μM ketamine, 30% N 2 O administered for 15–20 minutes resulted in persistent enhancement of synaptic responses mediated by both AMPA receptors and NMDA receptors. Synaptic enhancement by both N 2 O and ketamine was blocked by co-administration of a competitive NMDA receptor antagonist at saturating concentration, but only ketamine was blocked by an AMPA receptor antagonist. Synaptic enhancement by both agents involved TrkB (tropomyosin receptor kinase B), mTOR (mechanistic target of rapamycin), and NOS (nitric oxide synthase) with some differences between N 2 O and ketamine. N 2 O potentiation occluded enhancement by ketamine, and in vivo N 2 O exposure occluded further potentiation by both N 2 O and ketamine. These results indicate that N 2 O has ketamine-like effects on hippocampal synaptic function at a subanesthetic, but therapeutically relevant concentration. These 2 rapid antidepressants have similar, but not identical mechanisms that result in persisting synaptic enhancement, possibly contributing to psychotropic actions. [ABSTRACT FROM AUTHOR]

The progressive decline of the anatomical architecture and loss of functional integrity of an individual is aging. Accumulation of degenerative cellular and molecular changes in the aging cells increases the fragility at the cellular and molecular levels. It pushes towards age-associated diseases like Alzheimer's disease, hypertension, cancer, cardiovascular diseases, etc. The impaired T cell function in aging is a leading contributor to increased susceptibility to pathogens, minimized vaccine response, and skewed inflammation. Recent studies about the role of T cells in the remodelling of the immune system have provided ways to examine and explore aging puzzles and their correlation with T cell functions. Here we review the metabolic aspect of T cell function and its possible restoration. IL-7 and mTOR mediated pathways and their association with reactivation of effector T cell function could help understanding the dark side of the compromised adaptive immune system, particularly T cell response, in aging. Understanding these crucial fundamentals could help design and target new molecules to prevent loss of T cell functionality in aging. [ABSTRACT FROM AUTHOR]

Chronic hepatitis B virus (HBV) infection continues to pose a significant global health challenge. However, therapeutic measures for a cure are lacking in clinical practice. Manganese, an essential trace element, has garnered attention due to its potential to activate innate immune pathways and its significant role in antiviral and antitumor immunity. Yet, the specific impact of manganese on chronic hepatitis B has been largely unexplored. Our research reveals that manganese substantially inhibits HBV replication in hepatocellular carcinoma cells at non-toxic levels. This suppression occurs independently of well-known anti-HBV innate immune pathways, such as the cGAS-STING pathway. Mechanistically, manganese decreases HBV transcription by diminishing the levels of liver-specific transcription factors. Furthermore, it activates the mTOR pathway, enhancing HBsAg ubiquitination through the upregulation of the ubiquitin ligase β-TrCP and increasing proteasome activity via the augmentation of its subunits, leading to a ubiquitin-dependent degradation of HBsAg. Significantly, our study also uncovers a notable clinical correlation between manganese levels and chronic hepatitis B infection. These findings position manganese as a critical element in diminishing HBV replication, offering a new direction in the management of chronic hepatitis B. • Manganese inhibits HBV replication at non-toxic levels. • Manganese at non-toxic levels inhibits HBV replication independent of the innate immune pathways. • Manganese decreases HBV transcription by diminishing the levels of liver-specific transcription factors. • Manganese accelerates the degradation of HBsAg by activating the mTOR/UPS pathway. • This study reveals a significant clinical correlation between manganese levels and chronic hepatitis B infection. [ABSTRACT FROM AUTHOR]

Ischaemic stroke (IS) is the second leading cause of death and a major cause of disability worldwide. Currently, the clinical management of IS still depends on restoring blood flow via pharmacological thrombolysis or mechanical thrombectomy, with accompanying disadvantages of narrow therapeutic time window and risk of haemorrhagic transformation. Thus, novel pathophysiological mechanisms and targeted therapeutic candidates are urgently needed. The autophagy-lysosomal pathway (ALP), as a dynamic cellular lysosome-based degradative process, has been comprehensively studied in recent decades, including its upstream regulatory mechanisms and its role in mediating neuronal fate after IS. Importantly, increasing evidence has shown that IS can lead to lysosomal dysfunction, such as lysosomal membrane permeabilization, impaired lysosomal acidity, lysosomal storage disorder, and dysfunctional lysosomal ion homeostasis, which are involved in the IS-mediated defects in ALP function. There is tightly regulated crosstalk between transcription factor EB (TFEB), mammalian target of rapamycin (mTOR) and lysosomal function, but their relationship remains to be systematically summarized. Notably, a growing body of evidence emphasizes the benefits of naturally derived compounds in the treatment of IS via modulation of ALP function. However, little is known about the roles of natural compounds as modulators of lysosomes in the treatment of IS. Therefore, in this context, we provide an overview of the current understanding of the mechanisms underlying IS-mediated ALP dysfunction, from a lysosomal perspective. We also provide an update on the effect of natural compounds on IS, according to their chemical structural types, in different experimental stroke models, cerebral regions and cell types, with a primary focus on lysosomes and autophagy initiation. This review aims to highlight the therapeutic potential of natural compounds that target lysosomal and ALP function for IS treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] Mitochondrial dysfunction is associated with hyperglycemic conditions and insulin resistance leading to cellular damage and apoptosis of cardiomyocytes in diabetic cardiomyopathy. The dysregulation of glucagon-like peptide-1 (GLP-1) receptor and mammalian target of rapamycin (mTOR) is linked to cardiomyopathies and myocardial dysfunctions mediated by hyperglycemia. However, the involvements of mTOR for GLP-1 receptor-mediated cardioprotection against high glucose (HG)-induced mitochondrial disturbances are not clearly identified. The present study demonstrated that HG-induced cellular stress and mitochondrial damage resulted in impaired ATP production and oxidative defense markers such as catalase and SOD2, along with a reduction in survival markers such as Bcl-2 and p-Akt, while an increased expression of pro-apoptotic marker Bax was observed in H9c2 cardiomyoblasts. In addition, the autophagic marker LC3-II was considerably reduced, together with the disruption of autophagy regulators (p-mTOR and p-AMPKα) under the hyperglycemic state. Furthermore, there was a dysregulated expression of several indicators related to mitochondrial homeostasis, including MFN2, p-DRP1, FIS1, MCU, UCP3, and Parkin. Remarkably, treatment with either exendin-4 (GLP-1 receptor agonist) or rapamycin (mTOR inhibitor) significantly inhibited HG-induced mitochondrial damage while co-treatment of exendin-4 and rapamycin completely reversed all mitochondrial abnormalities. Antagonism of GLP-1 receptors using exendin-(9–39) abolished these cardioprotective effects of exendin-4 and rapamycin under HG conditions. In addition, exendin-4 attenuated HG-induced phosphorylation of mTOR, and this inhibitory effect was antagonized by exendin-(9–39), indicating the regulation of mTOR by GLP-1 receptor. Therefore, improvement of mitochondrial dysfunction by stimulating the GLP-1 receptor/AMPK/Akt pathway and inhibiting mTOR signaling could ameliorate cardiac abnormalities caused by hyperglycemic conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] Chronic Kidney Disease (CKD) is a significant global health issue linked to dietary habits, especially high salt intake. However, the precise mechanisms driving this progression remain incompletely understood. This study reveals that a high-salt diet intensifies macrophage trained immunity, leading to a marked pro-inflammatory response upon repeated pathogenic exposures, as evidenced by increased renal damage and fibrosis. Under high-salt conditions, there was an induction of CD45+F4/80+ macrophage infiltration into the renal tissue, accompanied by heightened production of inflammatory cytokines. Distinct responses were observed between circulating and resident renal macrophages to a high-salt diet, with a notable upsurge in the migration of pro-inflammatory macrophages, driven by CCL2-CCR2 signaling and aberrant mTORC1 pathway activation. Treatment with rapamycin-liposome effectively reduced this inflammatory cascade by mitigating mTORC1 signaling. Transplantation of monocytes from CKD mice with a high-salt diet significantly exacerbates renal inflammatory damage in the host mice, showing increased migratory tendency and inflammatory activity. The cell co-culture experiment further confirmed that macrophages derived from CKD mice, particularly those under conditions of high salt exposure, significantly induced apoptosis and inflammatory responses in renal tubular cells. Taken together, recurrent exposure to LPS elicits the activation of trained immunity, consequently augmenting inflammatory response of monocytes/macrophages in the involved kidneys. The high-salt diet exacerbates this phenomenon, attributable at least in part to the overactivation of the mTORC1 pathway. This research emphasizes the importance of dietary modulation and targeted immunological interventions in slowing CKD progression, providing new insights into mTORC1-mediated pathophysiological mechanisms and potential management strategies for CKD. [ABSTRACT FROM AUTHOR]

Glucose transporter-2 (GLUT2), a unique high capacity/low affinity, highly efficient membrane transporter and sensor, regulates hypothalamic astrocyte glucose phosphorylation and glycogen metabolism. The phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway participates in glucose homeostasis, but its sensitivity to glucose-sensory cues is unknown. Current research used a hypothalamic astrocyte primary culture model to investigate whether glucoprivation causes PI3K/Akt/mTOR pathway activation in one or both sexes by GLUT2-dependent mechanisms. Glucoprivation did not alter astrocyte PI3K levels, yet up-regulated both phosphorylated derivatives in female and down-regulated male p60 phosphoprotein expression. GLUT2 siRNA pretreatment diminished glucoprivic patterns of PI3K and phospho-PI3K expression in each sex. Astrocyte Akt and phospho-Akt/Thr308 proteins exhibited divergent, sex-contingent responses to GLUT2 gene knockdown or glucoprivation. GLUT2 siRNA pretreatment exacerbated glucoprivic-associated Akt diminution in the female, and either amplified (male) or reversed (female) glucoprivic regulation of phospho-Akt/Thr308 expression. GLUT2 gene silencing down- (male) or up-(female) regulated mTOR protein, and phospho-mTOR protein in male. Male astrocyte mTOR and phospho-mTOR profile were refractory to glucoprivation, but glucose-deprived females showed GLUT2-independent mTOR inhibition and GLUT2-dependent phospho-mTOR up-augmentation. Results identify a larger number of glucoprivic-sensitive PI3K/Akt/mTOR pathway proteins in female versus male astrocytes, and document divergent responses of common glucose-sensitive targets. GLUT2 stimulates phosphoPI3K protein expression in each sex, but imposes differential control of PI3K, Akt, phospho-Akt/Thr308, mTOR, and phospho-mTOR profiles in male versus female. Data implicate GLUT2 as a driver of distinctive pathway protein responses to glucoprivation in female, but not male. [Display omitted] • The high-capacity glucose transporter-2 (GLUT2) functions as a glucose sensor in brain. • GLUT2 regulation of hypothalamic astrocyte PI3K/Akt/mTOR signal cascade is unknown. • Female astrocytes express more glucoprivic-sensitive PI3K/Akt/mTOR proteins than male. • Glucose-sensitive cascade proteins show divergent, sex-specific responses to glucoprivation. • GLUT2 drives PI3K/Akt/mTOR protein responses to glucoprivation in female, not male. [ABSTRACT FROM AUTHOR]

• Sestrin2 overexpression in POMC neurons alleviates diet-induced obesity and the associated metabolic dysregulation. • Sestrin2 overexpression in POMC neurons decreases adipocyte size, triggers sympathetic activation, and stimulates lipolysis. • Sestrin2 overexpression in POMC neurons increases energy expenditure after HFD feeding. • Sestrin2 overexpression in POMC neurons inhibits the mTOR pathway activation. Sestrin2 is a highly conserved protein that can be induced under various stress conditions. Researches have revealed that the signaling pathway of the mammalian target of rapamycin (mTOR) is essential in modulating both glucose and lipid metabolism. However, the precise involvement of Sestrin2 in the hypothalamus, particularly in pro-opiomelanocortin (POMC) neurons, in control of energy homeostasis remains uncertain. In this study, we aimed to investigate the functional role of Sestrin2 in hypothalamic POMC neurons in regulation of energy balance, as well as revealing the underlying mechanisms. Therefore, cre-dependent AAV virus encoding or silencing Sestrin2 was injected into the hypothalamic ARC of pomc-cre transgenic mice. The results demonstrated that Sestrin2 overexpression in POMC neurons ameliorated high-fat diet (HFD)-induced obesity and increased energy expenditure. Conversely, Sestrin2 deficiency in POMC neurons predisposed mice to HFD induced obesity. Additionally, the thermogenesis of brown adipose tissue and lipolysis of inguinal white adipose tissue were both enhanced by the increased sympathetic nerve innervation in Sestrin2 overexpressed mice. Further exploration revealed that Sestrin2 overexpression inhibited the mTOR signaling pathway in hypothalamic POMC neurons, which may account for the alleviation of systematic metabolic disturbance induced by HFD in these mice. Collectively, our findings demonstrate that Sestrin2 in POMC neurons plays a pivotal role in maintaining energy balance in a context of HFD-induced obesity by inhibiting the mTOR pathway, providing new insights into how hypothalamic neurons respond to nutritional signals to protect against obesity-associated metabolic dysfunction. [ABSTRACT FROM AUTHOR]

Erjingpill, a well-known prescription documented in the classic Chinese medical text "Shengji Zonglu," has been proven to have effective alleviating effects on neuroinflammation in Alzheimer's disease (AD). Although the alterations in microglial cell glycolysis are known to play a crucial role in the development of neuroinflammation, it remains unclear whether the anti-neuroinflammatory effects of Erjingpill are associated with its impact on microglial cell glycolysis. This study aims to determine whether Erjingpill exerts anti-neuroinflammatory effects by influencing microglial cell glycolysis. Firstly, Erjingpill decoction was prepared into an Erjingpill bionic cerebrospinal fluid (EBCF) through a process of in vitro intestinal absorption, hepatocyte incubation, and blood-brain barrier (BBB) transcytosis. Subsequently, UPLC/Q-TOF-MS/MS technology was used to analyze the compounds in Erjingpill and EBCF. Next, an in vitro neuroinflammation model was established by LPS-induced BV2 cells. The impact of EBCF on BV2 cell proliferation activity was evaluated using the CCK-8 assay, while the NO release was assessed using the Griess assay. Additionally, mRNA levels of pro-inflammatory factors (IL-1β, IL-6, TNF-α, and COX-2), anti-inflammatory factors (IL-10, IL-4, Arg-1, and TGF-β), M1 microglial markers (iNOS, CD86), M2 microglial markers (CD36, CD206), and glycolytic enzymes (HK2, GLUT1, PKM, and LDHA) were measured using qPCR. Furthermore, protein expression of microglial activation marker Iba-1, M1 marker iNOS, and M2 marker CD206 were identified through immunofluorescence, while concentrations of pro-inflammatory cytokines IL-1β and TNF-α were measured using ELISA. Enzymatic activity of glycolytic enzymes (HK, PK, and LDH) was assessed using assay kits, and the protein levels of pro-inflammatory factors (IL-1β, iNOS, and COX-2), anti-inflammatory factors (IL-10 and Arg-1), and key glycolytic proteins GLUT1 and PI3K/AKT/mTOR were detected by Western blot. Through the analysis of Erjingpill and EBCF, 144 compounds were identified in Erjingpill and 40 compounds were identified in EBCF. The results demonstrated that EBCF effectively inhibited the elevation of inflammatory factors and glycolysis levels in LPS-induced BV2 cells, promoted polarization of M1 microglial cells towards the M2 phenotype, and suppressed the PI3K/AKT/mTOR inflammatory pathway. Moreover, EBCF alleviated LPS-induced BV2 cell inflammatory response by modulating mTOR to inhibit glycolysis. EBCF exhibits significant anti-neuroinflammatory effects, likely attributed to its modulation of mTOR to inhibit microglial cell glycolysis. This study furnishes experimental evidence supporting the clinical utilization of Erjingpill for preventing and treating AD. [Display omitted] • Using UPLC/Q-TOF-MS/MS, 144 chemicals were identified in Erjingpill and 40 in its bionic cerebrospinal fluid (EBCF). • EBCF significantly inhibited the inflammatory response in LPS-induced BV2 cells. • EBCF markedly suppressed the elevation of glycolysis levels in LPS-induced BV2 cells. • EBCF exerts anti-neuroinflammatory effects by modulating mTOR to inhibit glycolysis in microglial cells. [ABSTRACT FROM AUTHOR]

• Cataract is a leading cause of global blindness; it is crucial to understand its pathogenesis to improve cataract prevention. • Hyperhomocysteine is associated with cataracts. • hyperhomocysteine inhibits autophagy and connexin expression in the lens epithelial cells by activation of the mTOR. Hyperhomocysteine has been recognized as an independent risk factor of multiple diseases, including several eye diseases. In this study, we aim to investigate whether increased homocysteine (Hcy) is related to cataracts, and to explore whether dysregulation of mTOR-mediated autophagy and connexin expression are underlying mechanisms. We first developed a method of liquid chromatography tandem mass spectrometry to accurately measure serum concentrations of Hcy in 287 cataract patients and 334 healthy controls. Next, we treated human lens epithelial (HLC-B3) cells with Hcy at different concentrations and durations, and then analyzed expression of autophagy-related markers and connexins, as well as phosphorylated mTOR (p-mTOR) in these cells by Western blotting. Formation of autophagic vacuoles and intracellular Ca2+ in the Hcy-treated cells were observed by fluorescence microscopy. Further, we performed a rescue experiment in the Hcy-treated HLC-B3 cells by pre-incubation with rapamycin, an mTOR inhibitor. The serum levels of Hcy in patients with cataracts were significantly increased compared to those in healthy controls. In cultured HLC-B3 cells, expression of autophagy related markers (LC3B and Beclin1) and connexins (Cx43 and Cx50) was inhibited by Hcy treatment in a dose- and duration-dependent manner. Accumulation of Ca2+ in the Hcy-treated lens epithelial cells was observed as a consequence of reduced connexin expression. Meanwhile, expression of p-mTOR increased, representing up-regulation of the mTOR pathway. Importantly, inhibition of autophagy and connexin expression due to hyperhomocysteine was rescued via mTOR suppression by pretreatment with rapamycin in HLC-B3 cells. Our results demonstrate that hyperhomocysteine might promote cataract development through two mTOR-mediated pathways in the lens epithelial cells: 1) dysregulation of autophagy and 2) accumulation of intracellular calcium via decreased connexin expression. [ABSTRACT FROM AUTHOR]

• CD4+T cells occurred pyroptosis along with mTOR overactivation in septic mice. • Inhibited PPARγ-Nrf2 axis impaired antioxidant response and promoted pyroptosis. • mTOR contributed to pyroptosis in CD4 + T cells by suppressing PPARγ-Nrf2 pathway. Sepsis is a systemic inflammatory response syndrome caused by a dysregulated host response to infection. CD4+T cell reduction is crucial to sepsis-induced immunosuppression. Pyroptosis, a programmed necrosis, is concerned with lymphocytopenia. Peroxisome proliferator-activated receptor gamma (PPARγ) regulated by upstream mTOR, exerts anti-pyroptosis effects. To investigate the potential effects of mTOR-PPARγ on sepsis-induced CD4+T cell depletion and the underlying mechanisms, we observed mTOR activation and pyroptosis with PPARγ-Nrf suppression through cecal ligation and puncture (CLP) sepsis mouse model. Further mechanism research used genetically modified mice with T cell-specific knockout mTOR or Tuberous Sclerosis Complex1 (TSC1). It revealed that mTOR mediated CD4 + T cell pyroptosis in septic mice by negatively regulating the PPARγ-Nrf2 signaling pathway. Taken together, mTOR–PPARγ-Nrf2 signaling mediated the CD4+ T cell pyroptosis in sepsis, contributing to CD4+T cell depletion and immunosuppression. [ABSTRACT FROM AUTHOR]

Seizures induce hippocampal subregion dependent enhancements in microglia/macrophage phagocytosis and cytokine release that may contribute to the development of epilepsy. As a model of hyperactive mTOR induced epilepsy, neuronal subset specific phosphatase and tensin homolog (NS- Pten) knockout (KO) mice exhibit hyperactive mTOR signaling in the hippocampus, seizures that progress with age, and enhanced hippocampal microglia/macrophage activation. However, it is unknown where microglia/macrophages are most active within the hippocampus of NS- Pten KO mice. We quantified the density of IBA1 positive microglia/macrophages in the CA1, CA2/3, and dentate gyrus of NS- Pten KO and wildtype (WT) male and female mice at 4, 10, and 15 weeks of age. NS- Pten KO mice exhibited an overall increase in the number of IBA1 positive microglia/macrophages in each subregion and in the entire hippocampus. After accounting for differences in size, the whole hippocampus of NS- Pten KO mice still exhibited an increased density of IBA1 positive microglia/macrophages. Subregion analyses showed that this increase was restricted to the dentate gyrus of both male and female NS- Pten KO mice and to the CA1 of male NS- Pten KO mice. These data suggest enhanced microglia/macrophage activity may occur in the NS- Pten KO mice in a hippocampal subregion and sex-dependent manner. Future work should seek to determine whether these region-specific increases in microgliosis play a role in the progression of epilepsy in this model. [Display omitted] • Study confirms heightened microglia response in NS-Pten KO mice. • NS-Pten KO mice show increased microglial density in dentate gyrus. • NS-Pten KO mice display distinct microgliosis patterns. • Sex-specific differences observed in microglial density. • Enhanced microglial accumulation in CA1 and dentate gyrus. [ABSTRACT FROM AUTHOR]

Accumulation of senescent cells is a recognized feature in hepatocellular carcinoma (HCC), but their specific types and prognostic implications remain under investigation. This study aimed to delineate senescent cell types and their senescent patterns in HCC using publicly available bulk and single-cell mRNA sequencing data. Through gene expression and gene set enrichment analysis, we identified distinct senescent patterns within HCC samples. Notably, unconventional T cells, specifically natural killer T cells and γδT cells, were found to be the predominant senescent cell types. These cells exhibited enriched pathways related to DNA damage, senescence and the negative regulation of lymphocyte activation. Furthermore, we observed upregulation of the mTOR signaling pathway, which correlated positively with the expression of senescence-associated genes. This suggests a potential regulatory role for mTOR in the senescence of HCC. Strikingly, patients with elevated expression of senescence markers, including p16 INK4A , p21 , and GLB1 , demonstrated significantly reduced overall survival rates. Our findings indicate that immunosenescence in unconventional T cells may play a role in HCC progression. The potential therapeutic implications of targeting the mTOR pathway or eliminating senescent unconventional T cells warrant further exploration to improve HCC patient outcomes. [Display omitted] • Unconventional T cells including NKT cells and γδT cells showed a predominant senescent signature in HCC. • Senescent unconventional T cells in HCC might weaken the immune system against tumor development and lead to a worse overall survival rate. • Expression of mTOR showed a positively correlation with senescence associated genes in HCC. [ABSTRACT FROM AUTHOR]

Intestinal barrier dysfunction characterized by the functional loss of the intestinal epithelium's tight junction (TJ) barrier is a key factor in the pathogenesis of ulcerative colitis (UC). Although rapamycin, an mTOR (mechanistic target of rapamycin) inhibitor, has shown promise in inducing clinical remission and mucosal healing in inflammatory bowel disease, its underlying mechanism remains elusive. Thus, this study investigated the role of the mTOR pathway in regulating the intestinal barrier. To investigate the molecular mechanism regulating the intestinal barrier, specific intestinal epithelial phenazine biosynthesis-like domain-containing protein (PBLD)-deficient (PBLDIEC−/−) mice and control wild-type (WT) mice were intraperitoneally injected with rapamycin or MHY1485. To determine the relevance of the findings for UC, we analyzed transcriptome data and single-cell expression profiles from public databases and intestinal mucosal tissues obtained from patients with active UC or colon cancer. We observed that mTOR activation in the intestinal epithelium of patients with active UC. Moreover, in vivo, rapamycin markedly increased the expressions of PBLD and TJ proteins and reduced intestinal inflammation in mice with dextran sulfate sodium-induced enteritis. However, the therapeutic efficacy of rapamycin was notably reduced in PBLDIEC−/− mice. In vitro, rapamycin influenced PBLD expression by modulating the nuclear transcription of transcription factor EB (TFEB). Angiomotin (AMOT) could directly bind to PBLD, and rapamycin could not effectively increase the expression of TJ proteins after the knockdown of PBLD or AMOT. In summary, the administration of rapamycin is a potential treatment for UC, and targeting the mTOR/PBLD/AMOT axis is a potential novel approach for UC treatment. In patients with ulcerative colitis (UC), mTOR is markedly activated in the intestinal epithelium. The inhibition of mTOR increases the expression of PBLD through TFEB. mTOR suppression enables PBLD to directly interact with AMOT, consequently influencing the expression of TJ proteins and enhancing the intestinal barrier. [Display omitted] • mTOR is activated in intestinal epithelium in patients with active UC. • PBLD can directly bind to AMOT and the interaction between AMOT and PBLD regulates the expression of tight junction proteins. • mTOR affects the expression of PBLD by influencing the nuclear transcription of TFEB. • The mTOR/PBLD/AMOT axis plays an important role in regulating the repair of the intestinal epithelial barrier in UC. [ABSTRACT FROM AUTHOR]

The regulation of iron (Fe) levels is essential to maintain an adequate supply for erythropoiesis, among other processes, and to avoid possible toxicity. The liver-produced peptide hepcidin is regarded as the main regulator of Fe absorption in enterocytes and release from hepatocytes and macrophages, as it impairs Fe export through ferroportin. The glycoprotein erythropoietin (Epo) drives erythroid progenitor survival and differentiation in the bone marrow, and has been linked to the mobilization of Fe reserves necessary for hemoglobin production. Herein we show that Epo inhibits hepcidin expression directly in the HepG2 hepatic cell line, thus leading to a decrease in intracellular Fe levels. Such inhibition was dependent on the Epo receptor-associated kinase JAK2, as well as on the PI3K/AKT/mTOR pathway, which regulates nutrient homeostasis. Epo was also found to decrease binding of the C/EBP-α transcription factor to the hepcidin promoter, which could be attributed to an increased expression of its inhibitor CHOP. Epo did not only hinder the stimulating effect of C/EBP-α on hepcidin transcription, but also favored hepcidin inhibition by HIF-1α, by increasing is nuclear translocation as well as its protein levels. Moreover, in assays with the inhibitor genistein, this transcription factor was found necessary for Epo-induced hepcidin suppression. Our findings support the involvement of the PI3K/AKT/mTOR pathway in the regulation of Fe levels by Epo, and highlight the contrasting roles of the C/EBP-α and HIF-1α transcription factors as downstream effectors of the cytokine in this process. [Display omitted] • Erythropoietin (Epo) downregulates hepcidin directly in the HepG2 cell line. • This requires the activation of EpoR followed by the JAK2/PI3K/AKT/mTOR pathway. • Epo affects binding of the C/EBP-α transcription enhancer to the hepcidin promoter. • The inhibitory effect of HIF-1α on hepcidin expression is also stimulated by Epo. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silychristin, silybin, and isosilybin were the silymarin components in MT extract. • MT extract topical application attenuated IMQ-induced psoriasis in mice. • Psoriasis was reduced by MT via PI3K/AKT/mTOR molecular cascade inhibition. • MT extract suppressed KEAP1/NF-κB and augmented NRF2. • Combined anti-inflammatory & antioxidant effects contribute to MT's benefit. Silybum marianum , known as milk thistle (MT), is traditionally used to manage liver diseases. This study aimed to investigate the role of MT extract topical application as a potential treatment for imiquimod (IMQ)-induced psoriatic lesions in mice with particular emphasis on phosphoinositol-3 Kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) and Kelch-like ECH-associated protein 1 (KEAP1)/ nuclear factor erythroid-2-related factor (NRF2)/ nuclear factor-kappa B (NF-κB) molecular cascades involvement. To address this aim, forty male Swiss albino mice were subdivided into four groups (n = 10 mice/group): control, IMQ model, standard group where mice were treated topically with IMQ, then the anti-psoriatic mometasone cream, and MT extract-treated group where mice were treated topically with IMQ followed by MT extract. In most measured parameters, MT extract, rich in silymarin, exhibited potent anti-psoriatic activity comparable to the standard cortisone treatment. MT extract mitigated dorsal skin erythema, scaling, and epidermal thickening, reflected by lowering the Psoriasis Area Severity Index (PASI) score. Moreover, it alleviated IMQ-induced splenomegaly. Mechanistically, the PI3K/AKT/mTOR pathway was the main functional pathway behind such improvements, where it was significantly inhibited by MT extract application. This led to NRF2 activation via KEAP1 downregulation with subsequent anti-inflammatory effect proven by reducing NF-κB, interleukin (IL)–23, and IL-17A and antioxidant ability proven by boosting the antioxidant glutathione and heme oxygenase-1. Such improvements were confirmed by alleviating the histopathological alteration. Thus, MT extract could be a promising therapeutic agent for psoriasis treatment by inhibiting PI3K/AKT/mTOR cascade, along with NRF2 signaling activation. [ABSTRACT FROM AUTHOR]

Calorie restriction (CR) extends lifespan and healthspan in diverse species. Comparing ad libitum - and CR-fed mice is challenging due to their significantly different feeding patterns, with CR-fed mice consuming their daily meal in 2 h and then subjecting themselves to a prolonged daily fast. Here, we examine how ad libitum - and CR-fed mice respond to tests performed at various times and fasting durations and find that the effects of CR—insulin sensitivity, circulating metabolite levels, and mechanistic target of rapamycin 1 (mTORC1) activity—result from the specific temporal conditions chosen, with CR-induced improvements in insulin sensitivity observed only after a prolonged fast, and the observed differences in mTORC1 activity between ad libitum - and CR-fed mice dependent upon both fasting duration and the specific tissue examined. Our results demonstrate that much of our understanding of the effects of CR are related to when, relative to feeding, we choose to examine the mice. [Display omitted] • The observed effects of calorie restriction (CR) depend upon when the mice last ate • CR mice are insulin resistant relative to ad libitum mice when examined post-prandially • CR does not suppress muscle and hepatic mTORC1 activity • CR animals reprogram their metabolism to adapt to a daily fast Pak et al. find that many canonical effects of calorie restriction, including insulin sensitivity, result from the specific temporal conditions chosen. Feeding time, fasting duration, and the time of day the study is conducted have critical effects on the metabolic and molecular response to calorie restriction. [ABSTRACT FROM AUTHOR]

• Semisynthetic and inspired synthetic modifications of cucurbitacins are discussed. • Biological activities, and mechanistic pathways of these derivatives are covered. • An overview of SAR of these derivatives is presented. Cucurbitacins are natural products of the Cucurbitaceae family (cucumber, melon, gourd, etc.) and contain cucurbitane skeleton. They are oxygenated triterpenoids containing three six-membered rings, A, B, and C, and one five/seven-membered ring D. Traditionally, cucurbitacins containing plants are well-known to treat various diseases, including inflammation, cancer, and diabetes. The steroidal skeleton serves as a framework for numerous activities, yet simple substitutions in the skeleton's hotspots can significantly influence the bioactivities of naturally occurring cucurbitacins. We herein aim to comprehensively discuss and analyze various semisynthetic and inspired synthetic strategies of therapeutically pre-assembled cucurbitacins reported to date, emphasizing their potency, efficacy, and drug delivery improvement. Furthermore, a snapshot of the structure-activity relationships (SAR), biological activities, and mechanistic pathways of chemically modified cucurbitacins have also been deliberated. [Display omitted] [ABSTRACT FROM AUTHOR]

Skeletal muscle ischaemia-reperfusion injury (IRI) is a prevalent condition encountered in clinical practice, characterised by muscular dystrophy. Owing to limited treatment options and poor prognosis, it can lead to movement impairments, tissue damage, and disability. This study aimed to determine and verify the influence of transient receptor potential canonical 6 (TRPC6) on skeletal muscle IRI, and to explore the role of TRPC6 in the occurrence of skeletal muscle IRI and the signal transduction pathways activated by TRPC6 to provide novel insights for the treatment and intervention of skeletal muscle IRI. In vivo ischaemia/reperfusion (I/R) and in vitro hypoxia/reoxygenation (H/R) models were established, and data were comprehensively analysed at histopathological, cellular, and molecular levels, along with the evaluation of the exercise capacity in mice. By comparing TRPC6 knockout mice with wild-type mice, we found that TRPC6 knockout of TRPC6 could reduced skeletal muscle injury after I/R or H/R, of skeletal muscle, so as therebyto restoringe some exercise capacity inof mice. TRPC6 knockdown can reduced Ca2+ overload in cells, therebyo reducinge apoptosis. In additionAdditionally, we also found that TRPC6 functionsis not only a key ion channel involved in skeletal muscle I/R injury, but also can affects Ca2+ levels and then phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signalling pathway. by knocking downTherefore, knockdown of TRPC6, so as to alleviated the injury inducedcaused by skeletal muscle I/R or and H/R. These findingsdata indicate that the presence of TRPC6 exacerbatescan aggravate the injury of skeletal muscle injury after I/Rischemia/reperfusion, leading towhich not only causes Ca2+ overload and apoptosis., Additionally, it impairsbut also reduces the self- repair ability of cells by inhibiting the expression of the PI3K/Akt/mTOR signalling pathway. ETo exploringe the function and role of TRPC6 in skeletal muscle maycan presentprovide a novelew approachidea for the treatment of skeletal muscle ischemia/reperfusion injury. • knockout of TRPC6 can reduce ischemia ischemia-reperfusion injury of skeletal muscle. • Discovery that TRPC6 can regulate apoptosis of skeletal muscle during ischemia-reperfusion through the PI3K/Akt/mTOR pathway. • TRPC6 knockout decreases intracellular calcium levels in skeletal muscle. • TRPC6 knockout can reduce the apoptosis of skeletal muscle during ischemia reperfusion. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is an autoimmune disease, governed by oligodendrocyte (OL) dystrophy and central nervous system (CNS) demyelination manifesting variable neurological impairments. Mitochondrial mechanisms may drive myelin biogenesis maintaining the axo-glial unit according to dynamic requisite demands imposed by the axons they ensheath. The promotion of OL maturation and myelination by actively transporting thyroid hormone (TH) into the CNS and thereby facilitating key transcriptional and metabolic pathways that regulate myelin biogenesis is fundamental to sustain the profound energy demands at each axo-glial interface. Deficits in regulatory functions exerted through TH for these physiological roles to be orchestrated by mature OLs, can occur in genetic and acquired myelin disorders, whereby mitochondrial efficiency and eventual dysfunction can lead to profound oligodendrocytopathy, demyelination and neurodegenerative sequelae. TH-dependent transcriptional and metabolic pathways can be dysregulated during acute and chronic MS lesion activity depriving OLs from critical acetyl-CoA biochemical mechanisms governing myelin lipid biosynthesis and at the same time altering the generation of iron metabolism that may drive ferroptotic mechanisms, leading to advancing neurodegeneration • People living with progressive MS exhibit expanding lesions independent of relapse activity. • Oligodendrocyte and axonal damage during progressive MS show mitochondrial dysfunction that may promulgate demyelinated lesions. • Thyroid hormone non-genomic mitochondrial signaling may be deficient in the oligodendrocytes near brain lesions in people living with MS. • Thyroid hormone signaling through the PI3K/Akt/mTor pathway for mitochondrial acetyl-CoA. [ABSTRACT FROM AUTHOR]

Caspase-8, a caspase protein, is involved in the regulation of multiple cell death modes and has a predominant role in cell death. Cancer-associated mutations in the protein-coding region of caspase-8 have been widely reported in several solid tumors and might lead to the loss of its apoptotic function and contribute to the pathogenesis of tumors. However, the specific function and molecular mechanisms of mutant caspase-8 in the development of esophageal squamous cell carcinoma (ESCC) remain unknown. Here, we identified caspase-8 mutants exert tumor-promoting properties in ESCC, patients with the mutants presented a worse prognosis, and caspase-8 mutants lost the suppressive effect on tumor growth in ESCC cells. In addition, we demonstrated that caspase-8 mutants gain a new function of abolishing excess reactive oxygen species (ROS) to maintain ESCC cell growth under oxidative stress. An Nrf2 inhibitor reduced the effects of caspase-8 mutants against oxidative stress. Caspase-8 mutants combined with mTOR to phosphorylate SQSTM1 at Ser349, facilitating the interaction of SQSTM1 and Keap1 and reducing the degradation of the Nrf2 protein. Therefore, our study demonstrated that caspase-8 mutants gain a new function of protecting against oxidative stress via the mTOR/SQSTM1/Keap1/Nrf2 axis in ESCC. Caspase-8 status may be a new prognostic factor for survival in ESCC patients. [Display omitted] • Caspase-8 mutants exert tumor-promoting properties in ESCC. • Caspase-8 mutants gain a new function of abolishing excess ROS to maintain ESCC cell growth under oxidative stress. • Caspase-8 mutants protects against oxidative stress via the mTOR/SQSTM1/KEAP1/NRF2 axis. [ABSTRACT FROM AUTHOR]

• A phosphoproteomic survey of muscle stem cell progeny reveals that syndecans-3 regulates tyrosine kinase receptor-mediated signal transduction at multiple levels, including insulin/INSR signaling as one of the most enriched pathways. • The presence of syndecan-3 in muscle stem cells during the early stages of myogenesis inhibits insulin/INSR signaling via AKT/mTOR leading to muscle stem cell progeny expansion. • Syndecan-3 downregulation during the late stages of myogenesis releases the block on AKT/mTOR activation by insulin/INSR, leading to muscle stem cell progeny differentiation. • Syndecan-3 acts as a timekeeper of myogenesis, by functioning as a molecular switch for insulin signaling in muscle stem cell progeny. Muscle stem cells (MuSCs) are indispensable for muscle regeneration. A multitude of extracellular stimuli direct MuSC fate decisions from quiescent progenitors to differentiated myocytes. The activity of these signals is modulated by coreceptors such as syndecan-3 (SDC3). We investigated the global landscape of SDC3-mediated regulation of myogenesis using a phosphoproteomics approach which revealed, with the precision level of individual phosphosites, the large-scale extent of SDC3-mediated regulation of signal transduction in MuSCs. We then focused on INSR/AKT/mTOR as a key pathway regulated by SDC3 during myogenesis and mechanistically dissected SDC3-mediated inhibition of insulin receptor signaling in MuSCs. SDC3 interacts with INSR ultimately limiting signal transduction via AKT/mTOR. Both knockdown of INSR and inhibition of AKT restore Sdc3−/− MuSC differentiation to wild type levels. Since SDC3 is rapidly downregulated at the onset of differentiation, our study suggests that SDC3 acts a timekeeper to restrain proliferating MuSC response and prevent premature differentiation. [ABSTRACT FROM AUTHOR]

Background: Available anti-seizure medications (ASMs) target the symptomatology of the disease rather than any significant disease/epileptogenesis modifying actions. There are critical concerns of drug resistance and seizure recurrence during epilepsy management. So, drug repurposing is evolving as a paradigm change in the quest for novel epilepsy treatment strategies. Metformin, a well-known anti-diabetic drug has shown multiple pieces of evidence of its potential antiepileptic action.Objective: This review elucidates various mechanisms underlying the beneficial role of metformin in seizure control and modulation of the epileptogenesis process.Methods: Preclinical and clinical evidence involving metformin's role in epilepsy and special conditions like tuberous sclerosis have been reviewed in this paper. The putative mechanisms of epileptogenesis modulation through the use of metformin are also summarised.Results: This review found the efficacy of metformin in different seizure models including genetic knockout model, chemical induced, and kindling models. Only one clinical study of metformin in tuberous sclerosis has shown a reduction in seizure frequency and tumor volume compared to placebo. The suggested mechanisms of metformin relevant to epileptogenesis modulation mainly encompass AMPK activation, mTOR inhibition, protection against blood-brain-barrier disruption, inhibition of neuronal apoptosis, and reduction of oxidative stress. In addition to seizure protection, metformin has a potential role in attenuating adverse effects associated with epilepsy and ASMs such as cognition and memory impairment.Conclusion: Metformin has shown promising utility in epilepsy management and epileptogenesis modulation. The evidence in this review substantiates the need for a robust clinical trial to explore the efficacy and safety of metformin in persons with epilepsy. [ABSTRACT FROM AUTHOR]

Metabolic reprogramming is a hallmark of cancer and allows tumour cells to meet the increased energy demands required for rapid proliferation, invasion, and metastasis. Indeed, many tumour cells acquire distinctive metabolic and bioenergetic features that enable them to survive in resource-limited conditions, mainly by harnessing alternative nutrients. Several recent studies have explored the metabolic plasticity of cancer cells with the aim of identifying new druggable targets, while therapeutic strategies to limit the access to nutrients have been successfully applied to the treatment of some tumours. Cholangiocarcinoma (CCA), a highly heterogeneous tumour, is the second most common form of primary liver cancer. It is characterised by resistance to chemotherapy and poor prognosis, with 5-year survival rates of below 20%. Deregulation of metabolic pathways have been described during the onset and progression of CCA. Increased aerobic glycolysis and glutamine anaplerosis provide CCA cells with the ability to generate biosynthetic intermediates. Other metabolic alterations involving carbohydrates, amino acids and lipids have been shown to sustain cancer cell growth and dissemination. In this review, we discuss the complex metabolic rewiring that occurs during CCA development and leads to unique nutrient addiction. The possible role of therapeutic interventions based on metabolic changes is also thoroughly discussed. [ABSTRACT FROM AUTHOR]

ESK reverses LPS-induced depression-like behavior by activating mTOR to inhibit autophagic impairments, while the mTOR inhibitor rapamycin opposes ESK. [Display omitted] • ESK reverses LPS-induced depression-like behavior and alleviates both neuroinflammation and apoptosis. • The inhibition of autophagy by activating the mTOR-BDNF pathway is an essential mechanism for the antidepressant effect of ESK. • The combination of ESK with 3-MA did not enhance the antidepressant effect. Depression is a serious physical and mental disease, with major depressive disorder (MDD) being a hard-to-treat, life-threatening form of the condition. Currently, esketamine (ESK) is used in the clinical treatment of MDD, but the drug mechanisms continue to be unclear. In this study, we explored the therapeutic efficacy of ESK against lipopolysaccharide (LPS)-induced neuroinflammatory, autophagic, and depressive symptoms and the possible mechanisms behind them. Our study demonstrated that LPS increased cytokine levels (TNF-α, IL-1β, IL-6), induced neuroinflammation, led to increased levels of autophagy markers, and enhanced autophagy activation, which ultimately caused depressive symptoms in mouse models. ESK inhibited autophagy via the mTOR-BDNF signaling pathway and significantly alleviated the adverse effects induced by LPS, mainly in the form of reduced levels of cytokines, apoptotic factors, and autophagic markers; elevated BDNF levels; and improved depression-like behavior. Furthermore, we were interested to know if ESK in combination with other autophagy inhibitors would have a better antidepressant effect, and we chose the autophagy inhibitor 3-MA for this attempt. Interestingly, the use of 3-MA did not attenuate or even enhance the therapeutic effect of ESK. The results suggest that, in the LPS-induced depression models, ESK conveyed an antidepressant effect via the inhibition of autophagy through the mTOR-BDNF pathway. [ABSTRACT FROM AUTHOR]

Cadmium (Cd)-induced bone damage may be mediated through activating osteoclastogenesis. However, the underlying mechanism is unknown. The purpose of this study was to explore the effect and possible mechanism of CdCl 2 -induced osteoclastogenesis in RAW264.7 cells. We found that a low concentration of CdCl 2 (0.025 and 0.050 µM) did not affect the viability of RAW264.7 cells, but promoted osteoclastogenesis. A low concentration of CdCl 2 increased the mRNA and protein expression of osteoclastogenesis-related genes. TRAP staining and transmission electron microscopy (TEM) also demonstrated that CdCl 2 promoted osteoclastogenesis. A low concentration of CdCl 2 upregulated the levels of LC3-II and Beclin-1, and decreased p62 expression. TEM showed relatively abundant autophagic vacuoles (autophagosomes) after CdCl 2 exposure. A low concentration of CdCl 2 downregulated the expression levels of Mtor and p70S6K1 , and the relative protein expression ratios of p-mTOR/mTOR and p-p70S6K1/p70S6K1. When cells were treated with the autophagy inhibitor chloroquine (CQ) or mTOR activator MHY1485 combined with CdCl 2 , the expressions of osteoclastogenesis related-genes were decreased and autophagy was attenuated compared with cells treated with CdCl 2 alone. Deficiencies in autophagosomes and osteoclasts were also observed. Taken together, the results indicate that a low concentration of CdCl 2 promotes osteoclastogenesis by enhancing autophagy via inhibiting the mTOR/p70S6K1 signaling pathway. • CdCl 2 promotes RANKL-induced osteoclastogenesis in RAW264.7 cells by enhancing autophagy. • CdCl 2 inhibites the activities of mTOR and p70S6K1 in RANKL-induced osteoclastogenesis of RAW264.7 cells. • mTOR-mediated autophagy is involved in CdCl 2 -induced osteoclastogenesis. [ABSTRACT FROM AUTHOR]

• Picralima nitida (P. nitida) (Stapf.) T.A. Durand & H. Durand is an understory tree with antidiabetic effects. • P. nitida mitigates oxidative stress in the pancreas and liver of diabetic rats. • P. nitida alleviates oxidative stress by modulating the Nrf2-Keap 1 pathway in the liver and pancreas of diabetic rats. • P. nitida improve glucose metabolism by modulating the insulin signaling pathway in the liver and pancrease of diabetic rats. The aqueous leaf extract of Picralima nitida has been shown to produce antipyretic and anti-inflammatory effects in the management of several disease conditions, including diabetes. This study examined the ameliorative effect of aqueous seed extract of Picralima nitida on elevated liver enzymes, oxidative stress parameters, and impaired insulin pathway in high fat-fed streptozotocin-induced diabetic rats. Experimental rats (8 weeks old) were fed a control diet or a high-fat diet for 30 days, followed by a one-time intraperitoneal (i.p.) injection of streptozotocin (45 mg/kg). P. nitida (50, 100, and 150 mg/kg dose) and metformin (50 mg/kg dose) were administered orally to the rats for 21 days. The liver enzymes, antioxidant enzyme markers as well as certain metabolic genes implicated in the insulin signaling system, were also evaluated. When compared to the conventional antidiabetic drug metformin, P. nitida at 150 mg/kg causes a significant decrease in blood glucose and ameliorated liver damage in diabetic rats. Treatment with P. nitida at 150 mg/kg also showed a significant increase in the level of superoxide dismutase (SOD) and catalase (CAT) but a significant decrease in the level of malonaldehyde (MDA) in the diabetic rats. Furthermore, at all experimental doses assayed, P. nitida strongly raised the mRNA expression of Nrf2, PI3K, AKT, and mTOR, but dramatically downregulated the mRNA expression of Keap1 and PTEN. The study has thus far shown that P. nitida holds significant promise in mitigating liver damage, oxidative stress, and aberrations in insulin signaling pathway associated with high-fat diet streptozotocin-induced diabetes. [ABSTRACT FROM AUTHOR]

In response to environmental changes, signaling pathways rewire gene expression programs through transcription factors. Epigenetic modification of the transcribed RNA can be another layer of gene expression regulation. N6-adenosine methylation (m6A) is one of the most common modifications on mRNA. It is a reversible chemical mark catalyzed by the enzymes that deposit and remove methyl groups. m6A recruits effector proteins that determine the fate of mRNAs through changes in splicing, cellular localization, stability, and translation efficiency. Emerging evidence shows that key signal transduction pathways including TGFβ (transforming growth factor-β), ERK (extracellular signal-regulated kinase), and mTORC1 (mechanistic target of rapamycin complex 1) regulate downstream gene expression through m6A processing. Conversely, m6A can modulate the activity of signal transduction networks via m6A modification of signaling pathway genes or by acting as a ligand for receptors. In this review, we discuss the current understanding of the crosstalk between m6A and signaling pathways and its implication for biological systems. [ABSTRACT FROM AUTHOR]

In addition to their central functions in translation, ribosomes can adopt inactive structures that are fully assembled yet devoid of mRNA. We describe how the abundance of idle eukaryotic ribosomes is influenced by a broad range of biological conditions spanning viral infection, nutrient deprivation, and developmental cues. Vacant ribosomes may provide a means to exclude ribosomes from translation while also shielding them from degradation, and the variable identity of factors that occlude ribosomes may impart distinct functionality. We propose that regulated changes in the balance of idle and active ribosomes provides a means to fine-tune translation. We provide an overview of idle ribosomes, describe what is known regarding their function, and highlight questions that may clarify their biological roles. Idle, or vacant, ribosomes are broadly conserved, from prokaryotes to eukaryotes. Starvation, stress, development, and viral infection can influence the formation and elimination of vacant eukaryotic ribosomes. Recent structures reveal numerous protein factors that occlude functional sites on the ribosome, rendering them inactive. Idle ribosomes may represent means to regulate ribosome stoichiometry and subunit availability, amongst other yet-to-be determined functions potentially linked to nutrient sensing. [ABSTRACT FROM AUTHOR]

Adiponectin (AdipoQ) is a hormone that regulates food intake and energy homeostasis in mammals. The globular adiponectin (gAd) has been reported involved in the regulation of appetite, but the regulatory role and mechanism in fish remains unelucidated. Using Siberian sturgeon as a model of Chondrostei, the recombinant gAd protein of Siberian sturgeon (SsgAd) was produced by Escherichia coli expression system and verified using western blotting. Intraperitoneal injection of recombinant SsgAd protein at 100 ng/g BW suppressed food intake 1 h after administration. Peripheral injection of SsgAd protein caused the upregulation of anorexigenic pyy expression in the valvula intestine, but did not affect cck expression in the valvula intestine and orexigenic ghrelin expression in the stomach. The SsgAd administration significantly increased the hypothalamic expressions of pomc and decreased npy , agrp , and cart expression. In addition, SsgAd recombinant protein promoted adipor1 , ampkα2 , akt , and mtor mRNA expressions within the hypothalamus, whereas inhibited ampkβ1 , ampkβ2 and ampkγ2 mRNA expression, suggesting AMPK and mTOR signaling pathways might be related to SsgAd protein-mediated anorexia activity. Furthermore, the injection of an mTOR antagonist (rapamycin) reversed the reduced food intake and npy , agrp , and cart expression due to the peripheral injection of SsgAd, as well as the increased pomc expression induced by SsgAd, which were not observed after AMPK antagonist (dorsomorphin) treatment. In summary, the current study, for the first time, suggest that the anorexigenic function of SsgAd might bind with AdipoR1 and activate the mTOR signal pathway to affect the expression of hypothalamic appetite factors in Siberian sturgeon. This study provides new insight into the molecular mechanism of AdipoQ in feeding regulation in fish, and a basis for further exploration on physiological function of AdipoQ. • This study for the fist time demonstrated that SsgAd effectively inhibited food intake of Siberian sturgeon. • Peripheral SsgAd affected appetite factors expression in the hypothalamus and valvula intestine of Siberian sturgeon. • AdipoR1 rather than AdipoR2 was implicated in activation of hypothalamic appetite signals by SsgAd. • The inhibitory effect on food intake induced by peripheral SsgAd was reversed by mTOR antagonist in Siberian sturgeon. [ABSTRACT FROM AUTHOR]

[Display omitted] • Diabetic atria exhibited enhanced chemokine/cytokine-mediated signaling and inflammatory response. • Salidroside dose-dependently reduced atrial remodeling and AF susceptibility in diabetic mice. • Overactivation of mTOR-STAT3 signaling mediated the production of MCP1 and diabetes-related atrial damage. • Salidroside mitigated atrial inflammation and AF susceptibility by reducing mTOR-STAT3 signaling. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinic, and type 2 diabetes mellitus (T2DM) is an independent risk factor for AF. Salidroside (Sal), the active ingredient of the Rhodiola rosea , has hypoglycemic, anti-inflammatory, anti-fibrotic and anti-arrhythmic effects. The aim of this study is to investigate the effects and underlying molecular mechanisms of Sal on T2DM associated atrial inflammation and the pathogenesis of AF. In the in vivo study, T2DM mice model was established by high-fat diet and intraperitoneal injection of streptozotocin (STZ). Sal (25 mg/kg/d, 50 mg/kg/d, and 100 mg/kg/d) was administered orally for 4 weeks. T2DM caused atrial electrical and structural remodeling and significantly increased the susceptibility of AF. Meanwhile, mTOR-STAT3-MCP-1 signaling and inflammatory markers were also significantly enhanced in diabetic atria. However, Sal dose-dependently ameliorated cardiac dysfunction, mitigated atrial structural and electrical remodeling, and reduced atrial inflammation. Moreover, Sal-treated group exhibited remarkably down-regulated activity of mTOR-STAT3-MCP-1 pathway, and decreased atrial monocyte/macrophage infiltration. In palmitic acid (PA)-challenged HL-1 cells, Sal attenuated cytotoxicity, downregulated the expressions of TNF-α, IL-6, MCP-1, and inhibited the activation of mTOR-STAT3 signaling. However, co-treatment with MHY1485 (a mTOR agonist) reversed these effects. Taken together, the present study demonstrates that Sal treatment decreases the susceptibility of AF in diabetic mice by reducing mTOR-STAT3-MCP-1 signaling and atrial monocyte/macrophage infiltration. Sal treatment may represent a novel preventive therapy for cardiac arrhythmia and atrial fibrillation in diabetic patients. [ABSTRACT FROM AUTHOR]