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Rab11 family interacting protein 4 (Rab11-FIP4) regulates endocytic trafficking. A possible role for Rab11-FIP4 in the regulation of lysosomal function has been proposed, but its precise function in the regulation of cellular homeostasis is unknown. By mRNA array and protein analysis, we found that Rab11-FIP4 is downregulated in the lysosomal storage disease cystinosis, which is caused by genetic defects in the lysosomal cystine transporter, cystinosin. Rescue of Rab11-FIP4 expression in Ctns-/- fibroblasts re-established normal autophagosome levels and decreased LC3B-II expression in cystinotic cells. Furthermore, Rab11-FIP4 reconstitution increased the localization of the chaperone-mediated autophagy receptor LAMP2A at the lysosomal membrane. Treatment with genistein, a phytoestrogen that upregulates macroautophagy, or the CMA activator QX77 (CA77) restored Rab11-FIP4 expression levels in cystinotic cells supporting a cross-regulation between two independent autophagic mechanisms, lysosomal function and Rab11-FIP4. Improved cellular homeostasis in cystinotic cells rescued by Rab11-FIP4 expression correlated with decreased endoplasmic reticulum stress, an effect that was potentiated by Rab11 and partially blocked by expression of a dominant negative Rab11. Restoring Rab11-FIP4 expression in cystinotic proximal tubule cells increased the localization of the endocytic receptor megalin at the plasma membrane, suggesting that Rab11-FIP4 reconstitution has the potential to improve cellular homeostasis and function in cystinosis.

BCL-2 family members are known to be implicated in survival in numerous biological settings. Here, we provide evidence that in injury and repair processes in lungs, BCL-2 mainly acts to attenuate endoplasmic reticulum (ER) stress and limit extracellular matrix accumulation. Days after an intratracheal bleomycin challenge, mice lose a fraction of their alveolar type II epithelium from terminal ER stress driven by activation of the critical ER sensor and stress effector IRE1α. This fraction is dramatically increased by BCL-2 inhibition, because IRE1α activation is dependent on its physical association with the BCL-2-proapoptotic family member BAX, and we found BCL-2 to disrupt this association in vitro. In vivo, navitoclax (a BCL-2/BCL-xL inhibitor) given 15-21 days after bleomycin challenge evoked strong activation of IRE-1α in mesenchymal cells and markers of ER stress, but not apoptosis. Remarkably, after BCL-2 inhibition, bleomycin-exposed mice demonstrated persistent collagen accumulation at Day 42, compared with resolution in controls. Enhanced fibrosis proved to be due to the RNAase activity of IRE1α downregulating MRC2 mRNA and protein, a mediator of collagen turnover. The critical role of MRC2 was confirmed in precision-cut lung slice cultures of Day-42 lungs from bleomycin-exposed wild-type and MRC2 null mice. Soluble and tissue collagen accumulated in precision-cut lung slice cultures from navitoclax-treated, bleomycin-challenged mice compared with controls, in a manner nearly identical to that of challenged but untreated MRC2 null mice. Thus, apart from mitochondrial-based antiapoptosis, BCL-2 functions to attenuate ER stress responses, fostering tissue homeostasis and injury repair.

Mutations in myocilin (MYOC) are the leading known genetic cause of primary open-angle glaucoma, responsible for about 4% of all cases. Mutations in MYOC cause a gain-of-function phenotype in which mutant myocilin accumulates in the endoplasmic reticulum (ER) leading to ER stress and trabecular meshwork (TM) cell death. Therefore, knocking out myocilin at the genome level is an ideal strategy to permanently cure the disease. We have previously utilized CRISPR/Cas9 genome editing successfully to target MYOC using adenovirus 5 (Ad5). However, Ad5 is not a suitable vector for clinical use. Here, we sought to determine the efficacy of adeno-associated viruses (AAVs) and lentiviruses (LVs) to target the TM. First, we examined the TM tropism of single-stranded (ss) and self-complimentary (sc) AAV serotypes as well as LV expressing GFP via intravitreal (IVT) and intracameral (IC) injections. We observed that LV_GFP expression was more specific to the TM injected via the IVT route. IC injections of Trp-mutant scAAV2 showed a prominent expression of GFP in the TM. However, robust GFP expression was also observed in the ciliary body and retina. We next constructed lentiviral particles expressing Cas9 and guide RNA (gRNA) targeting MYOC (crMYOC) and transduction of TM cells stably expressing mutant myocilin with LV_crMYOC significantly reduced myocilin accumulation and its associated chronic ER stress. A single IVT injection of LV_crMYOC in Tg-MYOCY437H mice decreased myocilin accumulation in TM and reduced elevated IOP significantly. Together, our data indicates, LV_crMYOC targets MYOC gene editing in TM and rescues a mouse model of myocilin-associated glaucoma.

The placenta is a temporary organ that forms during pregnancy and is essential for fetal development and maternal health. As an endocrine organ, proper placental function requires continual production, folding, and transport of proteins and lipids. Central to these processes is the endoplasmic reticulum (ER), a dynamic organelle responsible for maintaining cellular protein and lipid synthesis and processing. ER stress occurs when there is an accumulation of unfolded or misfolded proteins, which triggers the activation of cellular pathways collectively called the unfolded protein response. Unfolded protein response pathways act to alleviate the misfolded protein burden and restore ER homeostasis, or if unresolved, initiate cell death. While prolonged ER stress has been linked to deficient placental function and adverse pregnancy outcomes, basal activation of unfolded protein response pathways is required for placental development and function. This review explores the importance of ER homeostasis in placental development and function, examining how disruptions in ER stress responses may contribute to adverse pregnancy outcomes. [ABSTRACT FROM AUTHOR]

The obstacle in delivering therapeutics to glioblastoma (GBM) is tumor-induced angiogenesis which leads to the formation of abnormal vessels and a dysfunctional blood-tumor barrier. Here, we elucidated the effect of endothelial-monocyte activating polypeptide II (EMAP II) on the GBM-induced angiogenesis as well as its potential mechanisms. Our results proved that EMAP II inhibited the viability, mitochondrial membrane potential, migration and tube formation of GBM-induced endothelial cells (GECs) by inducing cell autophagy, demonstrated by cell viability assay, JC-1 staining assay, transwell assay and tube formation assay, respectively. Cell autophagy was induced by EMAP II through the observation of autophagic vacuoles formation and the up-regulation of microtubule-associated protein-1 light chain-3 (LC3)-II and p62/SQSTM1 expression, demonstrated by transmission electron microscopy analysis, immunofluorescence assay and Western blot assay. The activity of PI3K/AKT/mTOR signal pathway could be inhibited by the EMAP II treatment. Furthermore, unfolded protein response (UPR)-related proteins (GRP78, eIF2α, and CHOP) were up-regulated by EMAP II, which suggest that GECs exposed to EMAP II experienced endoplasmic reticulum stress. Further, mechanistic investigations found that EMAP II reduced the miR-96 expression which could directly target the 3′-UTR of these UPR-related proteins, and over-expression of miR-96 inhibited LC3 and p62/SQSTM1 expression by down-regulating these UPR-related proteins in GECs. Moreover, the combination of EMAP II with miR-96 inhibitor showed the inhibitory effect on the viability, migration, and in vitro tube formation of GECs, which are critical for angiogenesis. Taken together, we have demonstrated the fact that EMAP II resulted in the decreased GBM-induced angiogenesis by inducing autophagy, which might contribute to establishing potential strategies for human GBM treatment. [ABSTRACT FROM AUTHOR]

Background: Periprosthetic osteolysis and subsequent aseptic loosening are the leading causes of failure following total joint arthroplasty. Osteogenic impairment induced by wear particles is regarded as a crucial contributing factor in the development of osteolysis, with endoplasmic reticulum (ER) stress identified as a key underlying mechanism. Therefore, identifying potential therapeutic targets and agents that can regulate ER stress adaption in osteoblasts is necessary for arresting aseptic loosening. Osthole (OST), a natural coumarin derivative, has demonstrated promising osteogenic properties and the ability to modulate ER stress adaption in various diseases. However, the impact of OST on ER stress-mediated osteogenic impairment caused by wear particles remains unclear. Methods: TiAl6V4 particles (TiPs) were sourced from the prosthesis of patients who underwent revision hip arthroplasty due to aseptic loosening. A mouse calvarial osteolysis model was utilized to explore the effects of OST on TiPs-induced osteogenic impairment in vivo. Primary mouse osteoblasts were employed to investigate the impact of OST on ER stress-mediated osteoblast apoptosis and osteogenic inhibition induced by TiPs in vitro. The mechanisms underlying OST-modulated alleviation of ER stress induced by TiPs were elucidated through Molecular docking, immunochemistry, PCR, and Western blot analysis. Results: In this study, we found that OST treatment effectively mitigated TiAl6V4 particles (TiPs)-induced osteolysis by enhancing osteogenesis in a mouse calvarial model. Furthermore, we observed that OST could attenuate ER stress-mediated apoptosis and osteogenic reduction in osteoblasts exposed to TiPs in vitro and in vivo. Mechanistically, we demonstrated that OST exerts bone-sparing effects on stressed osteoblasts upon TiPs exposure by specifically suppressing the ER stress-dependent PERK signaling cascade. Conclusion: Osthole ameliorates wear particle-induced osteogenic impairment by mitigating endoplasmic reticulum stress via PERK signaling cascade. These findings suggest that OST may serve as a potential therapeutic agent for combating wear particle-induced osteogenic impairment, offering a novel alternative strategy for managing aseptic prosthesis loosening. [ABSTRACT FROM AUTHOR]

Background: The increased degradation of the insulin receptor β subunit (InsRβ) in lysosomes contributes to the development of insulin resistance and type 2 diabetes mellitus. Endoplasmic reticulum (ER) stress contributes to insulin resistance through several mechanisms, including the reduction of InsRβ levels. Here, we examined how peroxisome proliferator-activated receptor (PPAR)β/δ regulates InsRβ levels in mouse skeletal muscle and C2C12 myotubes exposed to the ER stressor tunicamycin. Methods: Wild-type (WT) and Ppard−/− mice, WT mice treated with vehicle or the PPARβ/δ agonist GW501516, and C2C12 myotubes treated with the ER stressor tunicamycin or different activators or inhibitors were used. Results: Ppard−/− mice displayed reduced InsRβ protein levels in their skeletal muscle compared to wild-type (WT) mice, while the PPARβ/δ agonist GW501516 increased its levels in WT mice. Co-incubation of tunicamycin-exposed C2C12 myotubes with GW501516 partially reversed the decrease in InsRβ protein levels, attenuating both ER stress and the increase in lysosomal activity. In addition, the protein levels of the tyrosine kinase ephrin receptor B4 (EphB4), which binds to the InsRβ and facilitates its endocytosis and degradation in lysosomes, were increased in the skeletal muscle of Ppard−/− mice, with GW501516 reducing its levels in the skeletal muscle of WT mice. Conclusions: Overall, these findings reveal that PPARβ/δ activation increases InsRβ levels by alleviating ER stress and lysosomal degradation. [ABSTRACT FROM AUTHOR]

All-trans-retinal (atRAL)-induced photoreceptor atrophy and retinal degeneration are hallmark features of dry age-related macular degeneration (AMD) and Stargardt disease type 1 (STGD1). The toxicity of atRAL is closely related to the generation of reactive oxygen species (ROS). Quercetin, a natural product, is known for its potent antioxidant properties; however, its effects in mitigating atRAL-mediated retinal damage remains unclear. This study investigated the protective effects of quercetin against atRAL-induced photoreceptor damage. Using atRAL-loaded 661W photoreceptor cells, we evaluated cell viability, ROS generation, and endoplasmic reticulum (ER) stress under quercetin treatment. Quercetin significantly restored the cell viability (to 70%) and reduced ROS generation in atRAL-treated 661W cells. Additionally, Western blot analysis demonstrated that quercetin mitigated protein kinase RNA-like ER kinase (PERK) signaling, preventing ER stress-induced apoptosis. Importantly, in Abca4−/−Rdh8−/− mice, an animal model of light-induced atRAL accumulation in the retina, quercetin treatment effectively alleviated light-exposed photoreceptor atrophy and retinal degeneration by attenuating PERK signaling. Thus, quercetin protected photoreceptor cells from atRAL-induced damage by inhibiting ROS generation and PERK signaling, which suggests its potential as a therapeutic agent for atRAL-related retinal degeneration. [ABSTRACT FROM AUTHOR]

Epidemiological studies have linked fine dust pollution to depression, yet the underlying mechanisms remain unclear. Oxidative stress and endoplasmic reticulum (ER) stress are known contributors to depression, but their induction by particulate matter (PM), particularly PM2.5, in animal models has been limited. This study aimed to establish a rat model of PM2.5-induced depression-like behaviors and elucidate the underlying molecular mechanisms. Adult male Sprague–Dawley rats received daily intranasal PM2.5 for four weeks. Behavioral assessments, including the open field test (OFT), forced swim test (FST), and light-dark box (LDB) test, were conducted weekly. PM2.5-exposed rats displayed depressive-like behaviors, particularly in the FST, reflecting decreased motivation and learned helplessness. Molecular analyses indicated a specific increase in ER stress markers (CHOP, eIF2α, GRP78, and P16) and NOX4 in the hypothalamus, while other brain regions (striatum, cortex, and hippocampus) were not as pronounced. Additionally, PM2.5 exposure reduced tyrosine hydroxylase (TH) levels in the hypothalamus, suggesting impaired dopamine synthesis. These findings indicate that PM2.5 induces depressive-like behaviors via hypothalamic ER stress and oxidative stress pathways, leading to dopaminergic dysfunction. Targeting oxidative and ER stress within the hypothalamus may offer new therapeutic strategies for treating depression associated with environmental pollutants. [ABSTRACT FROM AUTHOR]

Background/Objectives: Peroxisome proliferator–activated receptor γ (PPARγ) plays a key role in mediating anti-inflammatory and anticancer effects in the tumor microenvironment. Kaurenoic acid (KA), a diterpene compound isolated from Sphagneticola trilobata (L.) Pruski, has been demonstrated to exert anti-inflammatory, anticancer, and antihuman immunodeficiency virus effects. Methods: In this study, we identified KA as a novel activator of PPARγ with potent anti-inflammatory and antitumor effects both in vitro and in vivo. Given the potential of PPARγ regulators in overcoming radioresistance and chemoresistance in cancer therapies, we hypothesized that KA may enhance the efficacy of breast cancer radiotherapy. Results: In a lipopolysaccharide (LPS)-induced mouse inflammation model, KA treatment reduced the levels of pro-inflammatory cytokines, including COX-2, IL-6, IL-1β, and TNFα. In a xenograft mouse mode of breast cancer, KA treatment inhibited tumor growth. Specifically, KA treatment enhanced caspase-3 activity and cytotoxicity against MDA-MB-231 and MCF-7 breast cancer cells. When KA was co-treated with a caspase inhibitor, Z-VAD-FMK, caspase-dependent apoptosis was suppressed in these cells. KA was found to induce the generation of cytosolic calcium ions (Ca2+) and reactive oxygen species (ROS), triggering endoplasmic reticulum (ER) stress via the PERK-ATF4-CHOP axis. Hence, the ER stressor thapsigargin (TG) synergized with KA treatment to enhance apoptosis in these cells, while the loss of the PERK or CHOP function inhibited this phenomenon. KA treatment was shown to induce oxidative stress via the NADPH oxidase 4 (NOX4) and stimulate ROS production. Specifically, NOX4 knockdown (KD) and antioxidant treatment (N-acetyl cysteine or diphenyleneiodonium) suppressed such ER stress–mediated apoptosis by inhibiting KA-enhanced caspase-3 activity, cytotoxicity, and intracellular ROS production in the treated cells. In radioresistant MDA-MB-231R and MCF-7R cells, KA combined with 2 Gy radiation overcame radioresistance by upregulating PPARγ and modulating epithelial–mesenchymal transition (EMT) markers, such as E-cadherin, N-cadherin, and vimentin. In PPARγ KD MDA-MB-231R and MCF-7R cells, this phenomenon was inhibited due to reduced PPARγ and NOX4 expression. Conclusions: In conclusion, these findings demonstrated KA as a novel PPARγ regulator with promising potential to enhance the efficacy of breast cancer radiotherapy. [ABSTRACT FROM AUTHOR]

Regulation of endoplasmic reticulum (ER) homeostasis plays a critical role in maintaining cell survival. When ER stress occurs, a network of three pathways called the unfolded protein response (UPR) is activated to reestablish homeostasis. While it is known that there is cross-talk between these pathways, how this complex network is regulated is not entirely clear. Using human cancer and non-cancer cell lines, two different genome-wide approaches, and two different ER stress models, we searched for miRNAs that were decreased during the UPR and surprisingly found only one, miR-1244, that was found under all these conditions. We also verified that ER-stress related downregulation of miR-1244 expression occurred with 5 different ER stressors and was confirmed in another human cell line (HeLa S3). These analyses demonstrated that the outcome of this reduction during ER stress supported both IRE1 signaling and elevated BIP expression. Further analysis using inhibitors specific for IRE1, ATF6, and PERK also revealed that this miRNA is impacted by all three pathways of the UPR. This is the first example of a complex mechanism by which this miRNA serves as a regulatory check point for all 3 pathways that is switched off during UPR activation. In summary, the results indicate that ER stress reduction of miR-1244 expression contributes to the pro-survival arm of UPR. [ABSTRACT FROM AUTHOR]

Aberrant regulation of unfolded protein response (UPR)/endoplasmic reticulum (ER) stress pathway is associated with cancer development, metastasis, and relapse, and the UPR signal transducer ATF6 has been proposed as a diagnostic and prognostic marker for many cancers. However, a causal molecular link between ATF6 activation and carcinogenesis is not established. Here, it is found that tumor protein D52 (TPD52) integrates ER stress and UPR signaling with the chaperone machinery by promoting S2P‐mediated cleavage of ATF6. Although TPD52 has been generally considered as an oncogene, TPD52 is identified as a novel tumor suppressor in bladder cancer. Significantly, attenuation of the ER stress via depletion of TPD52 facilitated tumorigenesis in a subset of human carcinomas. Furthermore, the APCCdc20 E3 ligase is validated as the upstream regulator marking TPD52 for polyubiquitination‐mediated proteolysis. In addition, inactivation of Cdc20 sensitized cancer cells to treatment with the ER stress inducer in a TPD52‐dependent manner. Thus, the study suggests that TPD52 is a novel Cdc20 substrate that may modulate ER stress to prevent tumorigenesis. [ABSTRACT FROM AUTHOR]

Aberrant regulation of unfolded protein response (UPR)/endoplasmic reticulum (ER) stress pathway is associated with cancer development, metastasis, and relapse, and the UPR signal transducer ATF6 has been proposed as a diagnostic and prognostic marker for many cancers. However, a causal molecular link between ATF6 activation and carcinogenesis is not established. Here, it is found that tumor protein D52 (TPD52) integrates ER stress and UPR signaling with the chaperone machinery by promoting S2P‐mediated cleavage of ATF6. Although TPD52 has been generally considered as an oncogene, TPD52 is identified as a novel tumor suppressor in bladder cancer. Significantly, attenuation of the ER stress via depletion of TPD52 facilitated tumorigenesis in a subset of human carcinomas. Furthermore, the APCCdc20 E3 ligase is validated as the upstream regulator marking TPD52 for polyubiquitination‐mediated proteolysis. In addition, inactivation of Cdc20 sensitized cancer cells to treatment with the ER stress inducer in a TPD52‐dependent manner. Thus, the study suggests that TPD52 is a novel Cdc20 substrate that may modulate ER stress to prevent tumorigenesis. [ABSTRACT FROM AUTHOR]

An ellagitannin-derived metabolite, Urolithin A (UA), has emerged as a potential therapeutic agent for metabolic disorders due to its antioxidant, anti-inflammatory, and mitochondrial function-improving properties, but its efficacy in protecting against ER stress remains underexplored. The endoplasmic reticulum (ER) is a cellular organelle involved in protein folding, lipid synthesis, and calcium regulation. Perturbations in these functions can lead to ER stress, which contributes to the development and progression of metabolic disorders such as metabolic-associated fatty liver disease (MAFLD). In this study, we identified a novel target protein of UA and elucidated its mechanism for alleviating palmitic acid (PA)-induced ER stress. Cellular thermal shift assay (CETSA)-LC-MS/MS analysis revealed that UA binds directly to the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase (SERCA), an important regulator of calcium homeostasis in mitochondria-associated ER membranes (MAMs). As an agonist of SERCA, UA attenuates abnormal calcium fluctuations and ER stress in PA-treated liver cells, thereby contributing to cell survival. The lack of UA activity in SERCA knockdown cells suggests that UA regulates cellular homeostasis through its interaction with SERCA. Collectively, our results demonstrate that UA protects against PA-induced ER stress and enhances cell survival by regulating calcium homeostasis in MAMs through SERCA. This study highlights the potential of UA as a therapeutic agent for metabolic disorders associated with ER stress. [ABSTRACT FROM AUTHOR]

Morbillivirus canis, commonly named Canine distemper virus (CDV), is a morbillivirus implicated in several signs in the Canidae family. In dogs (Canis lupus familiaris), common signs of infection include conjunctivitis, digital hyperkeratosis and neuropathologies. Even with vaccination, the canine distemper disease persists worldwide so the molecular pathways implicated in the infection processes have been an interesting and promising area in new therapeutic drugs research in recent years. It is known that in the process of virus infection, the endoplasmic reticulum (ER) loses its homeostasis, inducing stress and the subsequent unfolded protein response or UPR in which three ER-trans-membrane proteins are implicated: PERK, IRE1 and ATF6. Moreover, in prolonged ER stress, the apoptosis is induced through the CHOP, as a final step of viral infection. Cell culture and molecular techniques such as RT-qPCR and RT-PCR were used in the present study. We demonstrate the activation in vitro of the three UPR pathways after infection with an attenuated strain of CDV. Also, the implication of a MAPK pathway through the p38 protein and the apoptotic CHOP was demonstrated to contribute to the process of infection. Even more, our study suggested that CDV replication occurs in a PERK-dependent manner. [ABSTRACT FROM AUTHOR]

Type 1 diabetes (T1D) is a chronic autoimmune disorder characterised by an autoimmune response specifically mounted against the insulin-producing beta cells. Within the islet, high cellular connectivity and extensive vascularisation facilitate intra-islet communication and direct crosstalk with the surrounding tissues and the immune system. During the development of T1D, cytokines and extracellular vesicles released by beta cells can contribute to the recruitment of immune cells, further amplifying autoimmunity and aggravating beta cell damage and dysfunction. In this review, we will evaluate the role of beta-cell-derived extracellular vesicles as mediators of the autoimmune response and discuss their potential for early diagnosis and new therapeutic strategies in T1D. [ABSTRACT FROM AUTHOR]

High-grade serious ovarian cancer (HGSOC) is an aggressive malignancy that remains refractory to current immunotherapies. While advanced stage disease has been extensively studied, the cellular and molecular mechanisms that promote early immune escape in HGSOC remain largely unexplored. Here, we report that primary HGSO tumors program neutrophils to inhibit T cell anti-tumor function by activating the endoplasmic reticulum (ER) stress sensor IRE1α. We found that intratumoral neutrophils exhibited overactivation of ER stress response markers compared with their counterparts at non-tumor sites. Selective deletion of IRE1α in neutrophils delayed primary ovarian tumor growth and extended the survival of mice with HGSOC by enabling early T cell-mediated tumor control. Notably, loss of IRE1α in neutrophils sensitized tumor-bearing mice to PD-1 blockade, inducing HGSOC regression and long-term survival in ~ 50% of the treated hosts. Hence, neutrophil-intrinsic IRE1α facilitates early adaptive immune escape in HGSOC and targeting this ER stress sensor might be used to unleash endogenous and immunotherapy-elicited immunity that controls metastatic disease. [ABSTRACT FROM AUTHOR]

Prostate cancer is initially androgen‐dependent but often relapses to an androgen‐independent state called castration‐resistant prostate cancer (CRPC). Currently approved therapies have limited efficacy against CRPC, highlighting the need for novel therapeutic strategies. To address this need, we conducted a drug screen in our previously established aggressive CRPC cell model. We found that formycin A induced cell death in CRPC model cells but not in parental prostate cancer cells. In addition, formycin A upregulated death receptor 5 through the induction of endoplasmic reticulum stress, activating the "extrinsic" apoptosis pathway in CRPC model cells. Moreover, formycin A showed in vivo antitumor efficacy against CRPC xenografts in castrated nude mice. Thus, our findings highlight the potential of formycin A as a CRPC therapeutic. [ABSTRACT FROM AUTHOR]

The extract of the rhizome of Cnidium officinale Makino has potential anti-cancer and anti-inflammatory effects in many diseases, such as cancer. However, the biological functions of falcarindiol (FAD) in breast cancer are not fully understood. This study proved the anti-inflammatory and anti-cancer effects of FAD in breast cancer. Breast cancer models confirmed that FAD reduces cell viability and decreases the tumor volume of xenograft mouse models in a dose-dependent manner. FAD mediated caspase-3-dependent apoptosis in MDA-MB-231 and MCF-7 cells, whereas Z-VAD-FMK in combination with FAD inhibited caspase-3-induced apoptosis. FAD mediates apoptosis through cytosolic reactive oxygen species (ROS) and calcium (Ca2+) production and ER stress signaling pathways. In addition, FAD combined with thapsigargin (TG) exerts a synergistic apoptotic cell death effect. In the loss-of-function experiments, PERK or CHOP ablation suppressed intracellular ROS and Ca2+ release and ER stress-induced apoptosis in FAD-treated breast cancer models. Since there is a relationship between ROS and NADPH Oxidase 4 (NOX4), Nox4 ablation blocked ER stress-mediated apoptotic cell death by inhibiting ROS release in FAD-induced breast cancer models. Radioresistant models, such as MCF-7R and MDA-MB-231R, were developed to address the cellular radioresistance in clinical radiotherapy. FAD combined with radiation (2 Gy) overcame radioresistance via the inhibition of the epithelial–mesenchymal transition (EMT) phenomenon, such as the upregulation of PPARγ, VIM, and CDH2 and the downregulation of CDH1. Consequently, these results show that FAD may be a novel treatment as a breast cancer therapy. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a common autoimmune disease that can lead to irreversible joint damage when it occurs, but its pathogenesis has not yet been elucidated. In this study, we explored the roles of macrophage migration inhibitory factor (MIF), endoplasmic reticulum stress (ER stress), and Th17 cells in the pathogenesis of RA. We have preliminarily confirmed that MIF expression in CD4+T cells and the proportion of Th17 cells are increased in active RA patients. We also found that ER stress is activated, initiating ATF6 pathway in the UPR. Additionally, using in vitro stimulation and co-immunoprecipitation experiments, we have confirmed the interaction between MIF and ATF6, which enhances protein expression in ATF6 pathway. Subsequently, in the chromatin immunoprecipitation assay, we observed the enrichment of ATF6 subunit on the promoter sequences of the Th17 cell differentiation genes STAT3 and RORC. Additionally, the differentiation of Th17 cells was disrupted by Ceapin-A7 (ATF6 inhibitor). In summary, our results indicate that MIF enhances ATF6 pathway signaling, which promotes the differentiation of Th17 cells. This could be a potential mechanism underlying the pathogenesis of RA, offering a new direction for the clinical treatment of RA. [ABSTRACT FROM AUTHOR]

ER stress is a crucial factor in the progression of vascular cell diseases. Notably, octanoic acid (OA; C8:0) and decanoic acid (DA; C10:0), prominent components of medium‐chain fatty acids (MCFAs), may provide potential health benefits. However, their effects on vascular smooth muscle cells (VSMCs) remain unknown. Given the link between ER stress and vascular cell pathological conditions, the primary goal of this research is to investigate the protective effects of OA and DA against ER stress induction in rat aortic smooth muscle cells (RASMCs). To achieve this objective, RASMCs were pretreated with OA and DA at concentrations of 250 and 500 μM for 24 h. Subsequently, the cells were exposed to 1 μg/mL of tunicamycin, an ER stress inducer, for an additional 24 h. Apoptosis was assessed using DAPI staining, while DCFH2‐DA probe was used to measure ROS levels. Furthermore, the gene expression of ER stress markers, such as CHOP, GRP78, ATF4, and eIF2α, as well as contractile markers like αSMA and MYH11, was assessed using real‐time reverse transcription polymerase chain reaction. Moreover, the αSMA protein level was measured using immunocytochemistry techniques. The study revealed that OA and DA significantly mitigated cell death caused by tunicamycin, decreased ROS production, and inhibited the gene expression of ER stress markers (CHOP, GRP78, and eIF2α). Notably, OA and DA also inhibited the expression of contractile genes (α-SMA and MYH11) and reduced the number of α‐SMA‐positive cells in tunicamycin‐treated RASMCs. These findings indicate that OA and DA offer protection against ER stress–stimulated cell death and ROS generation in VSMCs, thereby supporting their potential therapeutic applications for safeguarding these cells. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis (OA) is a common degenerative joint disease, leading to pain and restricted mobility. Age-related endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of OA, but the underlying mechanisms remain unclear. This study aims to explore the relationship between age-related ER stress, YAP overexpression, and chondrocyte phenotype loss in the development of OA. Methods: Cartilage samples were collected from patients undergoing amputation, and age-related ER stress markers and YAP expression were assessed using immunohistochemical staining and qPCR. Transgenic mice with cartilage-specific YAP overexpression (YAPOE) were created, and Pamrevlumab was administered to evaluate its therapeutic effects. Results: Higher expression of ER stress markers and YAP were showed in aged tissues compared to younger tissues. YAP overexpression led to decreased levels of cartilage phenotype markers and increased osteogenesis-related proteins. In vivo , YAPOE mice exhibited OA-like cartilage degeneration, which was mitigated by Pamrevlumab treatment. Conclusion: Age-related ER stress induces YAP overexpression, contributing to OA pathogenesis. Pamrevlumab effectively prevents this phenotype loss in YAPOE mice, suggesting its potential as a therapeutic agent for OA. These findings provide new insights into the molecular mechanisms of OA and highlight the importance of targeting the ER stress-YAP-CTGF signaling pathway in OA treatment and prevention. [ABSTRACT FROM AUTHOR]

Background: In China, Tongguanteng injection (TGT) is widely used in the treatment or adjuvant treatment of various types of cancer. However, the effect and mechanism of TGT in osteosarcoma is not clear. Methods: The 143B and MG-63 cells were treated with different concentrations of TGT. Cell proliferation, migration, invasion and apoptosis were detected using CCK8 assay, transwell assay and flow cytometry. Differentially expressed genes (DEGs) were screened using RNA sequencing (RNA-seq). The identified mRNA and protein expression associated with the IRE1/CHOP pathway was validated by RT-PCR and western blot assay. To explore the underlying mechanisms, 4-phenylbutyric acid (4-PBA) was selected as a specific endoplasmic reticulum (ER) stress inhibitor. Small interfering RNA (siRNA) or pEX‐3-ERN1 plasmid was transfected into 143B cells to silence or overexpress IRE1, respectively. The potential downstream proteins, including CHOP, and apoptosis associated proteins, caspase-3 and PARP1 were determined. Furthermore, the effect of TGT was demonstrated in 143B cell tumor-bearing mice in vivo. H&E staining, TUNEL staining and immunohistochemistry were conducted in tumor tissues obtained from the xenograft mouse model. Results: TGT was shown to dramatically suppress the proliferation, migration and invasion, and induce apoptosis of osteosarcoma 143B and MG-63 cells in vitro. The identified DEGs included HSPA5 (encoding BiP) and ERN1 (encoding the IRE1 protein), as well as apoptosis-associated gene DDIT3 (encoding the CHOP protein). The term "IRE1-mediated unfolded protein response" was screened to be the most enriched biological process GO term. The expression of ER stress-associated proteins including ATF6, BiP, p-IRE1, XBP1s and CHOP, as well as apoptosis-associated cleaved caspase-3 and cleaved PARP1 proteins, was significantly upregulated by TGT treatment in osteosarcoma 143B cells, suggesting that TGT might promote the apoptosis of osteosarcoma 143B cells through the IRE1/CHOP pathway. Furthermore, knocking down IRE1 with si-IRE1 or inhibiting of ER stress with 4-PBA suppressed the expression of ATF6, BiP, XBP1s and CHOP induced by TGT, as well as the expression of cleaved caspase-3 and cleaved PARP1. On the contrary, overexpressing IRE1 promoted CHOP expression and induced osteosarcoma cell apoptosis. Consistent with in vitro results, TGT dramatically inhibited the tumor growth and promoted the expression of p-IRE1 and CHOP in tumor-bearing mice. Conclusion: The findings suggest that TGT exerts an anti-osteosarcoma effect in vitro and in vivo. The underlying mechanism might be associated with the activation of IRE1/CHOP pathway in ER stress. Our findings suggest that targeting IRE1/CHOP pathway might be a potential novel approach for osteosarcoma treatment. [ABSTRACT FROM AUTHOR]

Immunotherapy represents a widely employed modality in clinical oncology, leveraging the activation of the human immune system to target and eradicate cancer cells and tumor tissues via endogenous immune mechanisms. However, its efficacy remains constrained by inadequate immune responses within "cold" tumor microenvironment (TME). In this study, a multifunctional nanoscale pyroptosis inducer with cascade enzymatic activity (IMZF), comprising superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and glutathione oxidase (GSHOx), is dissociated within the acidic and glutathione‐rich TME. The vigorous enzymatic activity not only generates oxygen (O2) to alleviate hypoxia and promote M2 to M1 macrophage polarization but also yields reactive oxygen species (ROS) and depletes glutathione (GSH) within the TME. Functioning as an immunogenic cell death (ICD) activator and pyroptosis inducer, IMZF synergistically triggers dendritic cell maturation and inflammatory lymphocyte infiltration via ICD‐associated pyroptosis, thereby reversing immune suppression within the TMEs. Consequently, it exerts inhibitory effects on both primary and distal tumors. This cascade enzymatic platform‐based pyroptosis inducer offers an intelligent strategy for effectively overcoming immune suppression within "cold" tumors, thereby providing a promising avenue for advanced immunotherapeutic interventions. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease (PD) is a chronic neurodegenerative disorder that currently has no curable strategies. More and more evidence suggests that endoplasmic reticulum (ER) stress plays an essential role in PD pathogenesis. Periplaneta americana L. (P. americana) is a traditional Chinese medicine with diverse therapeutic properties. This study aims to investigate the neuroprotective effect and underlying mechanism of P. americana in in vitro and in vivo PD models. Methods: The exposure of SH-SY5Y cells to 1-methyl-4-phenyl-pyridinium (MPP+) was used as the in vitro PD model. MTT assay, Hoechst staining, Calcein AM-PI staining and flow cytometry were performed to measure the cell viability and apoptosis. DCFH-DA and JC-1 assay were used to measure the intracellular ROS and mitochondrial membrane potential (Δψm), respectively. Western-blot and immunostaining were conducted to detect the expression of key molecules related with ER stress. For the in vivo PD model induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydro-pyridine (MPTP), the motor function of mice was assessed by behavioral tests, the level of TH was examined by western-blot and immunostaining, the expression of key molecules related with ER stress was measured by western-blot. Results: Periplaneta americana ethanol extract (PAE) concentration-dependently inhibited MPP+-induced cell loss and increased cell viability. PAE also remarkably attenuated ROS accumulation, the decline of Δψm as well as the excessive ER stress. The neuroprotective effects of PAE could be blocked by ROS inducer trimethylamine N-Oxide or ER stress activator tunicaymycin, while the antioxidant N-Acetyl-L-cysteine or ER stress inhibitor sodium 4-phenylbutyrate mimicked the effects of PAE. Furthermore, we found that PAE could activate AKT/GSK3β/β-catenin pathway. The effect of PAE on ROS production, Δψm and ER stress was blocked by AKT inhibitor MK-2206. In in vivo model, PAE significantly improved motor function, prevented dopaminergic neuronal loss and attenuated ER stress in substantia nigra and striatum of MPTP-treated mice. Similarly, the effects of PAE on MPTP-treated mice were also abolished by MK-2206. Conclusions: Our results suggest that P. americana exerts neuroprotective effects through inhibiting ER stress via AKT-dependent pathway. Periplaneta americana may represent a promising therapeutic agent for PD treatment and is worthy of further being exploited. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress has been shown to play a pivotal role in the pathogenesis of asthma. DEPTOR (DEP Domain Containing MTOR Interacting Protein) is an endogenous mTOR inhibitor that participates in various physiological processes such as cell growth, apoptosis, autophagy, and ER homeostasis. However, the role of DEPTOR in the pathogenesis of asthma is still unknown. In this study, an ovalbumin (OVA)-induced mice model and IL-13 induced 16HBE cells were used to evaluate the effect of DEPTOR on asthma. A decreased DEPTOR expression was shown in the lung tissues of OVA-mice and IL-13 induced 16HBE cells. Upregulation of DEPTOR attenuated airway goblet cell hyperplasia, inhibited mucus hypersecretion, decreased the expression of mucin MUC5AC, and suppressed the level of inflammatory factors IL-4 and IL-5, which were all induced by OVA treatment. The increased protein expression of ER stress markers GRP78, CHOP, unfolded protein response (UPR) related proteins, and apoptosis markers in OVA mice were also inhibited by DEPTOR overexpression. In IL-13 induced 16HBE cells, overexpression of DEPTOR decreased IL-4, IL-5, and MUC5AC levels, preventing ER stress response and UPR process. Furthermore, from the proteomics results, we identified that SOD1 (Cu/Zn Superoxide Dismutase 1) may be the downstream factor of DEPTOR. Similar to DEPTOR, upregulation of SOD1 alleviated asthma progression. Rescue experiments showed that SOD1 inhibition abrogates the remission effect of DEPTOR on ER stress in vitro. In conclusion, these data suggested that DEPTOR attenuates asthma progression by suppressing endoplasmic reticulum stress through SOD1. [ABSTRACT FROM AUTHOR]

In plants, the BAX inhibitor-1 (BI-1) gene plays a crucial part in controlling cell death under stress conditions. This mechanism of Programmed Cell Death (PCD) is genetically regulated and is crucial for the elimination of unwanted or damaged cells in a controlled manner, which is essential for normal development and tissue maintenance. A study on cucumber identified and characterized five BI-1 genes: CsBI1, CsBI2, CsBI3, CsBI4, and CsBI5. These genes share conserved domains, indicating common evolutionary history and function. Physicochemical analysis revealed their molecular weights and isoelectric points, while subcellular localization showed their presence in different cellular compartments. The phylogenetic analysis highlighted evolutionary relationships with related crops. Chromosomal distribution and synteny analysis suggested segmental or tandem duplications within the gene family. Protein-protein interaction analysis revealed extensive interactions with other cucumber proteins. Cis-regulatory elements in the promoter regions provided insights into potential functions and transcriptional regulation. miRNAs showed diverse regulatory mechanisms, including mRNA cleavage and translational inhibition. The CsBI3, CsBI4 and CsBI5 genes exhibit elevated expression levels during cold stress, suggesting their vital involvement in cucumber plant defense mechanisms. The application of chitosan oligosaccharides externally confirms their distinct expression patterns. The qRT-PCR confirms the upregulation of CsBI genes in ToLCNDV-infected plants, indicating their potential to mitigate biotic and abiotic stresses. The comprehensive genome-wide exploration provides opportunities for the development of cold-tolerant and virus-resistant cucumber variants by traditional breeding or gene. [ABSTRACT FROM AUTHOR]

Islet transplantation is a promising approach for treating patients with unstable T1DM. However, it is confronted with numerous obstacles throughout the various stages of the transplantation procedure. Significant progress has been made over the last 25 years in understanding the mechanisms behind the loss of functional islet mass and in developing protective strategies. Nevertheless, at present, two to three pancreases are still needed to treat a single patient, which limits the maximal number of patients who can benefit from islet transplantation. Thus, this publication provides an overview of recent scientific findings on the various issues affecting islet transplantation. Specifically, we will focus on the understanding of the mechanisms involved and the strategies developed to alleviate these problems from the isolation stage to the post-transplantation phase. Finally, we hope that this review will highlight new avenues of action, enabling us to propose pancreatic islet transplantation to a maximum number of patients with T1DM. [ABSTRACT FROM AUTHOR]

Background: Diabetic retinopathy is the most common retinal vascular disease, affecting the retina's blood vessels and causing chronic inflammation, oxidative stress, and, ultimately, vision loss. Diabetes-induced elevated glucose levels increase glycolysis, the main methylglyoxal (MGO) formation pathway. MGO is a highly reactive dicarbonyl and the most rapid glycation compound to form endogenous advanced glycation end products (AGEs). MGO can act both intra- and extracellularly by glycating molecules and activating the receptor for AGEs (RAGE) pathway. Conclusions: This review summarizes the sources of MGO formation and its actions on various cell pathways in retinal cells such as oxidative stress, glycation, autophagy, ER stress, and mitochondrial dysfunction. Finally, the detoxification of MGO by glyoxalases is discussed. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (ER) is the organelle mainly involved in maintaining cellular homeostasis and driving correct protein folding. ER-dependent defects or dysfunctions are associated with the genesis/progression of several pathological conditions, including cancer, inflammation, and neurodegenerative disorders, that are directly or indirectly correlated to a wide set of events collectively named under the term "ER stress". Despite the recent increase in interest concerning ER activity, further research studies are needed to highlight all the mechanisms responsible for ER failure. In this field, recent discoveries paved the way for the comprehension of the strong interaction between ER stress development and the endocannabinoid system. The activity of the endocannabinoid system is mediated by the activation of cannabinoid receptors (CB), G protein-coupled receptors that induce a decrease in cAMP levels, with downstream anti-inflammatory effects. CB activation drives, in most cases, the recovery of ER homeostasis through the regulation of ER stress hallmarks PERK, ATF6, and IRE1. In this review, we focus on the CB role in modulating ER stress, with particular attention to the cellular processes leading to UPR activation and oxidative stress response extinguishment, and to the mechanisms underlying natural cannabinoids' modulation of this complex cellular machine. [ABSTRACT FROM AUTHOR]

Abstract Regulation of endoplasmic reticulum (ER) homeostasis plays a critical role in maintaining cell survival. When ER stress occurs, a network of three pathways called the unfolded protein response (UPR) is activated to reestablish homeostasis. While it is known that there is cross-talk between these pathways, how this complex network is regulated is not entirely clear. Using human cancer and non-cancer cell lines, two different genome-wide approaches, and two different ER stress models, we searched for miRNAs that were decreased during the UPR and surprisingly found only one, miR-1244, that was found under all these conditions. We also verified that ER-stress related downregulation of miR-1244 expression occurred with 5 different ER stressors and was confirmed in another human cell line (HeLa S3). These analyses demonstrated that the outcome of this reduction during ER stress supported both IRE1 signaling and elevated BIP expression. Further analysis using inhibitors specific for IRE1, ATF6, and PERK also revealed that this miRNA is impacted by all three pathways of the UPR. This is the first example of a complex mechanism by which this miRNA serves as a regulatory check point for all 3 pathways that is switched off during UPR activation. In summary, the results indicate that ER stress reduction of miR-1244 expression contributes to the pro-survival arm of UPR.

Quantum dots have diverse biomedical applications, from constructing biological infrastructures like medical imaging to advancing pharmaceutical research. However, concerns about human health arise due to the toxic potential of quantum dots based on heavy metals. Therefore, research on quantum dots has predominantly focused on oxidative stress, cell death, and other broader bodily toxicities. This study investigated the toxicity and cellular responses of mouse embryonic stem cells (mESCs) and mouse adult stem cells (mASCs) to nitrogen-doped carbon quantum dots (NCQDs) made of non-metallic materials. Cells were exposed to NCQDs, and we utilized a fluorescent ubiquitination-based cell system to verify whether NCQDs induce cytotoxicity. Furthermore, we validated the differentiation-inducing impact of NCQDs by utilizing embryonic stem cells equipped with the Oct4 enhancer-GFP reporter system. By analyzing gene expression including Crebzf, Chop, and ATF6, we also observed that NCQDs robustly elicited endoplasmic reticulum (ER) stress. We confirmed that NCQDs induced cytotoxicity and abnormal differentiation. Interestingly, we also confirmed that low concentrations of NCQDs stimulated cell proliferation in both mESCs and mASCs. In conclusion, NCQDs modulate cell death, proliferation, and differentiation in a concentration-dependent manner. Indiscriminate biological applications of NCQDs have the potential to cause cancer development by affecting normal cell division or to fail to induce normal differentiation by affecting embryonic development during pregnancy. Therefore, we propose that future biomedical applications of NCQDs necessitate comprehensive and diverse biological studies.

Abstract Rheumatoid arthritis (RA) is a common autoimmune disease that can lead to irreversible joint damage when it occurs, but its pathogenesis has not yet been elucidated. In this study, we explored the roles of macrophage migration inhibitory factor (MIF), endoplasmic reticulum stress (ER stress), and Th17 cells in the pathogenesis of RA. We have preliminarily confirmed that MIF expression in CD4+T cells and the proportion of Th17 cells are increased in active RA patients. We also found that ER stress is activated, initiating ATF6 pathway in the UPR. Additionally, using in vitro stimulation and co-immunoprecipitation experiments, we have confirmed the interaction between MIF and ATF6, which enhances protein expression in ATF6 pathway. Subsequently, in the chromatin immunoprecipitation assay, we observed the enrichment of ATF6 subunit on the promoter sequences of the Th17 cell differentiation genes STAT3 and RORC. Additionally, the differentiation of Th17 cells was disrupted by Ceapin-A7 (ATF6 inhibitor). In summary, our results indicate that MIF enhances ATF6 pathway signaling, which promotes the differentiation of Th17 cells. This could be a potential mechanism underlying the pathogenesis of RA, offering a new direction for the clinical treatment of RA.

Abstract Background In China, Tongguanteng injection (TGT) is widely used in the treatment or adjuvant treatment of various types of cancer. However, the effect and mechanism of TGT in osteosarcoma is not clear. Methods The 143B and MG-63 cells were treated with different concentrations of TGT. Cell proliferation, migration, invasion and apoptosis were detected using CCK8 assay, transwell assay and flow cytometry. Differentially expressed genes (DEGs) were screened using RNA sequencing (RNA-seq). The identified mRNA and protein expression associated with the IRE1/CHOP pathway was validated by RT-PCR and western blot assay. To explore the underlying mechanisms, 4-phenylbutyric acid (4-PBA) was selected as a specific endoplasmic reticulum (ER) stress inhibitor. Small interfering RNA (siRNA) or pEX‐3-ERN1 plasmid was transfected into 143B cells to silence or overexpress IRE1, respectively. The potential downstream proteins, including CHOP, and apoptosis associated proteins, caspase-3 and PARP1 were determined. Furthermore, the effect of TGT was demonstrated in 143B cell tumor-bearing mice in vivo. H&E staining, TUNEL staining and immunohistochemistry were conducted in tumor tissues obtained from the xenograft mouse model. Results TGT was shown to dramatically suppress the proliferation, migration and invasion, and induce apoptosis of osteosarcoma 143B and MG-63 cells in vitro. The identified DEGs included HSPA5 (encoding BiP) and ERN1 (encoding the IRE1 protein), as well as apoptosis-associated gene DDIT3 (encoding the CHOP protein). The term “IRE1-mediated unfolded protein response” was screened to be the most enriched biological process GO term. The expression of ER stress-associated proteins including ATF6, BiP, p-IRE1, XBP1s and CHOP, as well as apoptosis-associated cleaved caspase-3 and cleaved PARP1 proteins, was significantly upregulated by TGT treatment in osteosarcoma 143B cells, suggesting that TGT might promote the apoptosis of osteosarcoma 143B cells through the IRE1/CHOP pathway. Furthermore, knocking down IRE1 with si-IRE1 or inhibiting of ER stress with 4-PBA suppressed the expression of ATF6, BiP, XBP1s and CHOP induced by TGT, as well as the expression of cleaved caspase-3 and cleaved PARP1. On the contrary, overexpressing IRE1 promoted CHOP expression and induced osteosarcoma cell apoptosis. Consistent with in vitro results, TGT dramatically inhibited the tumor growth and promoted the expression of p-IRE1 and CHOP in tumor-bearing mice. Conclusion The findings suggest that TGT exerts an anti-osteosarcoma effect in vitro and in vivo. The underlying mechanism might be associated with the activation of IRE1/CHOP pathway in ER stress. Our findings suggest that targeting IRE1/CHOP pathway might be a potential novel approach for osteosarcoma treatment.

Abstract Endoplasmic reticulum (ER) stress has been shown to play a pivotal role in the pathogenesis of asthma. DEPTOR (DEP Domain Containing MTOR Interacting Protein) is an endogenous mTOR inhibitor that participates in various physiological processes such as cell growth, apoptosis, autophagy, and ER homeostasis. However, the role of DEPTOR in the pathogenesis of asthma is still unknown. In this study, an ovalbumin (OVA)-induced mice model and IL-13 induced 16HBE cells were used to evaluate the effect of DEPTOR on asthma. A decreased DEPTOR expression was shown in the lung tissues of OVA-mice and IL-13 induced 16HBE cells. Upregulation of DEPTOR attenuated airway goblet cell hyperplasia, inhibited mucus hypersecretion, decreased the expression of mucin MUC5AC, and suppressed the level of inflammatory factors IL-4 and IL-5, which were all induced by OVA treatment. The increased protein expression of ER stress markers GRP78, CHOP, unfolded protein response (UPR) related proteins, and apoptosis markers in OVA mice were also inhibited by DEPTOR overexpression. In IL-13 induced 16HBE cells, overexpression of DEPTOR decreased IL-4, IL-5, and MUC5AC levels, preventing ER stress response and UPR process. Furthermore, from the proteomics results, we identified that SOD1 (Cu/Zn Superoxide Dismutase 1) may be the downstream factor of DEPTOR. Similar to DEPTOR, upregulation of SOD1 alleviated asthma progression. Rescue experiments showed that SOD1 inhibition abrogates the remission effect of DEPTOR on ER stress in vitro. In conclusion, these data suggested that DEPTOR attenuates asthma progression by suppressing endoplasmic reticulum stress through SOD1.

Abstract Background Parkinson’s disease (PD) is a chronic neurodegenerative disorder that currently has no curable strategies. More and more evidence suggests that endoplasmic reticulum (ER) stress plays an essential role in PD pathogenesis. Periplaneta americana L. (P. americana) is a traditional Chinese medicine with diverse therapeutic properties. This study aims to investigate the neuroprotective effect and underlying mechanism of P. americana in in vitro and in vivo PD models. Methods The exposure of SH-SY5Y cells to 1-methyl-4-phenyl-pyridinium (MPP+) was used as the in vitro PD model. MTT assay, Hoechst staining, Calcein AM-PI staining and flow cytometry were performed to measure the cell viability and apoptosis. DCFH-DA and JC-1 assay were used to measure the intracellular ROS and mitochondrial membrane potential (Δψm), respectively. Western-blot and immunostaining were conducted to detect the expression of key molecules related with ER stress. For the in vivo PD model induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydro-pyridine (MPTP), the motor function of mice was assessed by behavioral tests, the level of TH was examined by western-blot and immunostaining, the expression of key molecules related with ER stress was measured by western-blot. Results Periplaneta americana ethanol extract (PAE) concentration-dependently inhibited MPP+-induced cell loss and increased cell viability. PAE also remarkably attenuated ROS accumulation, the decline of Δψm as well as the excessive ER stress. The neuroprotective effects of PAE could be blocked by ROS inducer trimethylamine N-Oxide or ER stress activator tunicaymycin, while the antioxidant N-Acetyl-L-cysteine or ER stress inhibitor sodium 4-phenylbutyrate mimicked the effects of PAE. Furthermore, we found that PAE could activate AKT/GSK3β/β-catenin pathway. The effect of PAE on ROS production, Δψm and ER stress was blocked by AKT inhibitor MK-2206. In in vivo model, PAE significantly improved motor function, prevented dopaminergic neuronal loss and attenuated ER stress in substantia nigra and striatum of MPTP-treated mice. Similarly, the effects of PAE on MPTP-treated mice were also abolished by MK-2206. Conclusions Our results suggest that P. americana exerts neuroprotective effects through inhibiting ER stress via AKT-dependent pathway. Periplaneta americana may represent a promising therapeutic agent for PD treatment and is worthy of further being exploited.

Abstract In plants, the BAX inhibitor-1 (BI-1) gene plays a crucial part in controlling cell death under stress conditions. This mechanism of Programmed Cell Death (PCD) is genetically regulated and is crucial for the elimination of unwanted or damaged cells in a controlled manner, which is essential for normal development and tissue maintenance. A study on cucumber identified and characterized five BI-1 genes: CsBI1, CsBI2, CsBI3, CsBI4, and CsBI5. These genes share conserved domains, indicating common evolutionary history and function. Physicochemical analysis revealed their molecular weights and isoelectric points, while subcellular localization showed their presence in different cellular compartments. The phylogenetic analysis highlighted evolutionary relationships with related crops. Chromosomal distribution and synteny analysis suggested segmental or tandem duplications within the gene family. Protein-protein interaction analysis revealed extensive interactions with other cucumber proteins. Cis-regulatory elements in the promoter regions provided insights into potential functions and transcriptional regulation. miRNAs showed diverse regulatory mechanisms, including mRNA cleavage and translational inhibition. The CsBI3, CsBI4 and CsBI5 genes exhibit elevated expression levels during cold stress, suggesting their vital involvement in cucumber plant defense mechanisms. The application of chitosan oligosaccharides externally confirms their distinct expression patterns. The qRT-PCR confirms the upregulation of CsBI genes in ToLCNDV-infected plants, indicating their potential to mitigate biotic and abiotic stresses. The comprehensive genome-wide exploration provides opportunities for the development of cold-tolerant and virus-resistant cucumber variants by traditional breeding or gene.