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Caloric restriction (CR) can extend the organism life- and health-span by improving glucose homeostasis. How CR affects the structure-function of pancreatic beta cells remains unknown. We used single nucleus transcriptomics to show that CR increases the expression of genes for beta cell identity, protein processing, and organelle homeostasis. Gene regulatory network analysis reveal that CR activates transcription factors important for beta cell identity and homeostasis, while imaging metabolomics demonstrates that beta cells upon CR are more energetically competent. In fact, high-resolution microscopy show that CR reduces beta cell mitophagy to increase mitochondria mass and the potential for ATP generation. However, CR beta cells have impaired adaptive proliferation in response to high fat diet feeding. Finally, we show that long-term CR delays the onset of beta cell aging hallmarks and promotes cell longevity by reducing beta cell turnover. Therefore, CR could be a feasible approach to preserve compromised beta cell structure-function during aging and diabetes.

A decline in mitochondrial function is a hallmark of aging and neurodegenerative diseases. It has been proposed that changes in mitochondrial morphology, including fragmentation of the tubular mitochondrial network, can lead to mitochondrial dysfunction, yet the mechanism of this loss of function is unclear. Most proteins contained within mitochondria are nuclear-encoded and must be properly targeted to the mitochondria. Here, we report that sustained mRNA localization and co-translational protein delivery leads to a heterogeneous protein distribution across fragmented mitochondria. We find that age-induced mitochondrial fragmentation drives a substantial increase in protein expression noise across fragments. Using a translational kinetic and molecular diffusion model, we find that protein expression noise is explained by the nature of stochastic compartmentalization and that co-translational protein delivery is the main contributor to increased heterogeneity. We observed that cells primarily reduce the variability in protein distribution by utilizing mitochondrial fission-fusion processes rather than relying on the mitophagy pathway. Furthermore, we are able to reduce the heterogeneity of the protein distribution by inhibiting co-translational protein targeting. This research lays the framework for a better understanding of the detrimental impact of mitochondrial fragmentation on the physiology of cells in aging and disease.

Activation of PINK1 and Parkin in response to mitochondrial damage initiates a response that includes phosphorylation of RAB7A at Ser72. Rubicon is a RAB7A binding negative regulator of autophagy. The structure of the Rubicon:RAB7A complex suggests that phosphorylation of RAB7A at Ser72 would block Rubicon binding. Indeed, in vitro phosphorylation of RAB7A by TBK1 abrogates Rubicon:RAB7A binding. Pacer, a positive regulator of autophagy, has an RH domain with a basic triad predicted to bind an introduced phosphate. Consistent with this, Pacer-RH binds to phosho-RAB7A but not to unphosphorylated RAB7A. In cells, mitochondrial depolarization reduces Rubicon:RAB7A colocalization whilst recruiting Pacer to phospho-RAB7A-positive puncta. Pacer knockout reduces Parkin mitophagy with little effect on bulk autophagy or Parkin-independent mitophagy. Rescue of Parkin-dependent mitophagy requires the intact pRAB7A phosphate-binding basic triad of Pacer. Together these structural and functional data support a model in which the TBK1-dependent phosphorylation of RAB7A serves as a switch, promoting mitophagy by relieving Rubicon inhibition and favoring Pacer activation.

The central nervous system coordinates peripheral cellular stress responses, including the unfolded protein response of the mitochondria (UPRMT); however, the contexts for which this regulatory capability evolved are unknown. UPRMT is up-regulated upon pathogenic infection and in metabolic flux, and the olfactory nervous system has been shown to regulate pathogen resistance and peripheral metabolic activity. Therefore, we asked whether the olfactory nervous system in Caenorhabditis elegans controls the UPRMT cell nonautonomously. We found that silencing a single inhibitory olfactory neuron pair, AWC, led to robust induction of UPRMT and reduction of oxidative phosphorylation dependent on serotonin signaling and parkin-mediated mitophagy. Further, AWC ablation confers resistance to the pathogenic bacteria Pseudomonas aeruginosa partially dependent on the UPRMT transcription factor atfs-1 and fully dependent on mitophagy machinery. These data illustrate a role for the olfactory nervous system in regulating whole-organism mitochondrial dynamics, perhaps in preparation for postprandial metabolic stress or pathogenic infection.

Mitophagy degrades damaged mitochondria, but we show here that it can also target functional mitochondria. This latter scenario occurs during programmed mitophagy and involves the mitophagy receptors NIX and BNIP3. Although AMP-activated protein kinase (AMPK), the energy-sensing protein kinase, can influence damaged-induced mitophagy, its role in programmed mitophagy is unclear. We found that AMPK directly inhibits NIX-dependent mitophagy by triggering 14-3-3-mediated sequestration of ULK1, via ULK1 phosphorylation at two sites: Ser556 and an additional identified site, Ser694. By contrast, AMPK activation increases Parkin phosphorylation and enhances the rate of depolarization-induced mitophagy, independently of ULK1. We show that this happens both in cultured cells and tissues in vivo , using the mito -QC mouse model. Our work unveils a mechanism whereby AMPK activation downregulates mitophagy of functional mitochondria but enhances that of dysfunctional/damaged ones. [Display omitted] • AMPK activation blocks NIX-dependent mitophagy • AMPK phosphorylates ULK1 to trigger inhibitory 14-3-3 binding • NIX-dependent mitophagy can target functioning mitochondria • Parkin-dependent mitophagy is enhanced by AMPK independently of ULK1 Under energetic stress, it is essential to balance dysfunctional versus healthy mitochondrial turnover. Longo and Bishnu et al. uncover a mechanism by which AMPK activation achieves this. They find that although AMPK enhances Parkin-mediated mitophagy upon mitochondrial damage, it blocks NIX-mediated mitophagy, which they now show can target functioning mitochondria. [ABSTRACT FROM AUTHOR]

During PINK1- and Parkin-mediated mitophagy, autophagy adaptors are recruited to damaged mitochondria to promote their selective degradation. Autophagy adaptors such as optineurin (OPTN) and NDP52 facilitate mitophagy by recruiting the autophagy-initiation machinery, and assisting engulfment of damaged mitochondria through binding to ubiquitinated mitochondrial proteins and autophagosomal ATG8 family proteins. Here, we demonstrate that OPTN and NDP52 form sheet-like phase-separated condensates with liquid-like properties on the surface of ubiquitinated mitochondria. The dynamic and liquid-like nature of OPTN condensates is important for mitophagy activity, because reducing the fluidity of OPTN-ubiquitin condensates suppresses the recruitment of ATG9 vesicles and impairs mitophagy. Based on these results, we propose a dynamic liquid-like, rather than a stoichiometric, model of autophagy adaptors to explain the interactions between autophagic membranes (i.e., ATG9 vesicles and isolation membranes) and mitochondrial membranes during Parkin-mediated mitophagy. This model underscores the importance of liquid-liquid phase separation in facilitating membrane-membrane contacts, likely through the generation of capillary forces. Synopsis: Autophagy adaptors undergo liquid-liquid phase separation, but it remains unclear how this contributes to selective mitochondrial autophagy. This study shows that the mitophagy adaptors OPTN and NDP52 phase-separate to facilitate mitochondrial recognition and mitophagy. OPTN and NDP52 form sheet-like condensates on ubiquitinated mitochondria during Parkin-mediated mitophagy. The liquid-like property of these adaptor condensates is important for mitophagy. Capillary forces of these condensates between mitochondria and autophagic membranes (i.e., ATG9 vesicles and isolation membranes) are likely to promote the attachment of these membranes. Damaged mitochondria are engulfed by autophagosomes through adhesive forces generated by wetting. [ABSTRACT FROM AUTHOR]

Mitochondrial dysfunction causes devastating disorders, including mitochondrial myopathy, but how muscle senses and adapts to mitochondrial dysfunction is not well understood. Here, we used diverse mouse models of mitochondrial myopathy to show that the signal for mitochondrial dysfunction originates within mitochondria. The mitochondrial proteins OMA1 and DELE1 sensed disruption of the inner mitochondrial membrane and, in response, activated the mitochondrial integrated stress response (mt-ISR) to increase the building blocks for protein synthesis. In the absence of the mt-ISR, protein synthesis in muscle was dysregulated causing protein misfolding, and mice with early-onset mitochondrial myopathy failed to grow and survive. The mt-ISR was similar following disruptions in mtDNA maintenance (Tfam knockout) and mitochondrial protein misfolding (CHCHD10 G58R and S59L knockin) but heterogenous among mitochondria-rich tissues, with broad gene expression changes observed in heart and skeletal muscle and limited changes observed in liver and brown adipose tissue. Taken together, our findings identify that the DELE1 mt-ISR mediates a similar response to diverse forms of mitochondrial stress and is critical for maintaining growth and survival in early-onset mitochondrial myopathy. Synopsis: Mitochondrial myopathies caused by diverse mitochondrial stressors, including mitochondrial DNA (mtDNA) depletion or mitochondrial protein misfolding, activate a similar transcriptional response in muscle. This report shows that this transcriptional response is predominately mediated by the DELE1-dependent mitochondrial integrated stress response (mt-ISR) pathway and is critical for maintaining growth and survival in mouse models. DELE1 is responsible for a protective ISR in response diverse mitochondrial stressors, including mtDNA depletion and mitochondrial protein misfolding. The DELE1-dependent mt-ISR is especially critical for growth and survival in the setting of early-onset mitochondrial stress. DELE1 and OMA1 have overlapping but separable protective effects in mitochondrial myopathies. The DELE1 mt-ISR increases the building blocks for cellular protein synthesis but fails to restore OXPHOS or resolve defects in mitochondrial structure. DELE1 is required to maintain folding of newly synthesized proteins in skeletal muscle under stress. DELE1, a mitochondrial stress signal, protects striated muscle cells by suppressing the misfolding of newly translated proteins. [ABSTRACT FROM AUTHOR]

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer lacking hormone receptors and HER2 expression, leading to limited treatment options and poor prognosis. Mitophagy, a selective autophagy process targeting damaged mitochondria, plays a complex role in cancer progression, yet its prognostic significance in TNBC is not well understood. Methods: This study utilized single-cell RNA sequencing data from the TCGA and GEO databases to identify mitophagy-related genes (MRGs) associated with TNBC. A prognostic model was developed using univariate Cox analysis and LASSO regression. The model was validated across multiple independent cohorts, and correlations between MRG expression, immune infiltration, and drug sensitivity were explored. Results: Nine key MRGs were identified and used to stratify TNBC patients into high-risk and low-risk groups, with the high-risk group showing significantly worse survival outcomes. The model demonstrated strong predictive accuracy across various datasets. Additionally, the study revealed a correlation between higher MRG expression levels and increased immune cell infiltration, as well as potential responsiveness to specific chemotherapeutic agents. Conclusion: The mitophagy-related prognostic model offers a novel method for predicting outcomes in TNBC patients and highlights the role of mitophagy in influencing the tumor microenvironment, with potential applications in personalized treatment strategies. [ABSTRACT FROM AUTHOR]

Contrast-induced acute kidney injury (CI-AKI) is one of the main causes of hospital-acquired renal failure, and still lacks of effective treatments. Previously, we demonstrated that αKlotho, which is an anti-aging protein that highly expresses in the kidney, has therapeutic activity in CI-AKI through promoting autophagy. However, the specific mechanism underlying αKlotho-mediated autophagy remains unclear. The RNA sequencing analysis of renal cortex revealed that the differentially expressed genes related to autophagy between αKlotho-treated CI-AKI mice and vehicle-treated CI-AKI mice were found to be associated with mitophagy and apoptosis. In the kidney of CI-AKI mice and HK-2 cells exposed to Iohexol, we revealed that αKlotho promoted mitophagy and decreased cell apoptosis. Mechanistically, αKlotho attenuated mitochondria damage, decreased mitochondrial ROS by upregulating BNIP3-mediated mitophagy. BNIP3 deletion abolished the beneficial effects of αKlotho both in vivo and in vitro. Moreover, we further demonstrated that αKlotho upregulated FoxO3 nuclear expression in Iohexol-treated HK-2 cells. Knockdown of FOXO3 gene inhibited αKlotho-promoted BNIP3-mediated mitophagy and subsequently increased the oxidative injury and cell apoptosis. Taken together, our results indicated a critical role of αKlotho in alleviating CI-AKI via mitophagy promotion involving the FoxO3-BNIP3 pathway. [ABSTRACT FROM AUTHOR]

Postoperative cognitive dysfunction (POCD) is a frequent neurological complication encountered during the perioperative period with unclear mechanisms and no effective treatments. Recent research into the pathogenesis of POCD has primarily focused on neuroinflammation, oxidative stress, changes in neural synaptic plasticity and neurotransmitter imbalances. Given the high-energy metabolism of neurons and their critical dependency on mitochondria, mitochondrial dysfunction directly affects neuronal function. Additionally, as the primary organelles generating reactive oxygen species, mitochondria are closely linked to the pathological processes of neuroinflammation. Surgery and anesthesia can induce mitochondrial dysfunction, increase mitochondrial oxidative stress, and disrupt mitochondrial quality-control mechanisms via various pathways, hence serving as key initiators of the POCD pathological process. We conducted a review on the role and potential mechanisms of mitochondria in postoperative cognitive dysfunction by consulting relevant literature from the PubMed and EMBASE databases spanning the past 25 years. Our findings indicate that surgery and anesthesia can inhibit mitochondrial respiration, thereby reducing ATP production, decreasing mitochondrial membrane potential, promoting mitochondrial fission, inducing mitochondrial calcium buffering abnormalities and iron accumulation, inhibiting mitophagy, and increasing mitochondrial oxidative stress. Mitochondrial dysfunction and damage can ultimately lead to impaired neuronal function, abnormal synaptic transmission, impaired synthesis and release of neurotransmitters, and even neuronal death, resulting in cognitive dysfunction. Targeted mitochondrial therapies have shown positive outcomes, holding promise as a novel treatment for POCD. [ABSTRACT FROM AUTHOR]

Mitophagy, the process by which cells eliminate damaged mitochondria, is mediated by PINK1 (PTEN induced kinase 1). Our recent research indicates that PINK1 functions as a tumor suppressor in colorectal cancer by regulating cellular metabolism. Interestingly, PINK1 ablation activated the NLRP3 (NLR family pyrin domain containing 3) inflammasome, releasing IL1B (interleukin 1 beta). However, inhibiting the NLRP3-IL1B signaling pathway with an IL1R (interleukin 1 receptor) antagonist or NLRP3 inhibitor did not hinder colon tumor growth after PINK1 loss. To identify druggable targets in PINK1-deficient tumors, ribonucleic acid sequencing analysis was performed on colon tumors from pink1 knockout and wild-type mice. Gene Set Enrichment Analysis highlighted the enrichment of iron ion transmembrane transporter activity. Subsequent qualitative polymerase chain reaction and western blot analysis revealed an increase in mitochondrial iron transporters, including mitochondrial calcium uniporter, in PINK1-deficient colon tumor cells and tissues. Live-cell iron staining demonstrated elevated cellular and mitochondrial iron levels in PINK1-deficient cells. Clinically used drugs deferiprone and minocycline reduced mitochondrial iron and superoxide levels, resulting in decreased colon tumor cell growth in vitro and in vivo. Manipulating the mitochondrial iron uptake protein MCU (mitochondrial calcium uniporter) also affected cell and xenograft tumor growth. This study suggests that therapies aimed at reducing mitochondrial iron levels may effectively inhibit colon tumor growth, particularly in patients with low PINK1 expression.Abbreviation: ANOVA: analysis of variance; APC: adenomatous polyposis coli; cAMP: cyclic adenosine monophosphate; CDX2: caudal type homeobox 2; CGAS: cyclic GMP-AMP synthase; CRC: colorectal cancer; DNA: deoxyribonucleic acid; DFP: deferiprone; DMEM: Dulbecco’s modified Eagle medium; DSS: dextran sodium sulfate; ERT2-Cre: Cre recombinase fused to a triple mutant form of the human estrogen receptor; EV: empty vector; GLB: glybenclamide/glyburide; H&E: hematoxylin and eosin; ICP-MS: inductively coupled plasma mass spectrometer; IL1B: interleukin 1 beta; kDa: kilodalton; MCU: mitochondrial calcium uniporter; MKI67: marker of proliferation Ki-67; mRNA: messenger ribonucleic acid; MTT: 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide; NLRP3: NLR family pyrin domain containing 3; OE: overexpression; PBS: phosphate-buffered saline; p-CREB: phosphorylated cAMP responsive element binding protein; PINK1: PTEN induced kinase 1; p-PRKAA/AMPK: phosphorylated protein kinase AMP-activated catalytic subunit alpha; qPCR: qualitative polymerase chain reaction; RNA-seq: ribonucleic acid sequencing; ROS: reactive oxygen species; sg: single guide; sh: short hairpin; SLC25A28: solute carrier family 25 member 28; SLC25A37/MFRN: solute carrier family 25 member 37; STING1: stimulator of interferon response cGAMP interactor 1; TP53/p53: tumor protein p53; TUBA: tubulin alpha; µL: microliter; µm: micrometer; µM: micromolar; mm: millimeter. [ABSTRACT FROM AUTHOR]

Background: Although the exact role of mitophagy in the pathogenesis of diabetic cardiomyopathy (DCM) caused by type 2 diabetes mellitus (T2DM) remains controversial, recent studies revealed inhibition of mitophagy exacerbates cardiac injury in DCM. The zinc transporter ZIP7 has been reported to be upregulated by high glucose in cardiomyocytes and ZIP7 upregulation leads to inhibition of mitophagy in mouse hearts in the setting of ischemia/reperfusion. Nevertheless, little is known about the role of ZIP7 and its relationship with mitophagy in DCM caused by T2DM. Methods: T2DM was induced with high-fat diet (HFD) and streptozotocin. The cardiac-specific ZIP7 conditional knockout (ZIP7 cKO) mice were generated by adopting CRISPR/Cas9 system. Cardiac function was evaluated with echocardiography. Mitophagy was assessed by detecting mito-LC3II, mitoKeima, and mitoQC. Reactive oxygen species (ROS) were detected with DHE and mitoB. Results: ZIP7 was upregulated by T2DM in mouse hearts and ZIP7 cKO reduced mitochondrial ROS generation in mouse hearts with T2DM. Mitophagy was suppressed by T2DM in mouse hearts, which was prevented by ZIP7 cKO. T2DM inhibited PINK1 and Parkin accumulation in cardiac mitochondria, an effect that was prevented by ZIP7 cKO, pointing to that ZIP7 upregulation mediates T2DM-induced suppression of mitophagy by inhibiting the PINK1/Parkin pathway. T2DM induced mitochondrial hyperpolarization and decrease of mitochondrial Zn2+ and this was blocked by ZIP7 cKO, indicating that upregulation of ZIP7 leads to mitochondrial hyperpolarization by reducing Zn2+ within mitochondria. Finally, ZIP7 cKO prevented cardiac dysfunction and fibrosis caused by T2DM. Conclusions: ZIP7 upregulation mediates the inhibition of mitophagy by T2DM in mouse hearts by suppressing the PINK1/Parkin pathway. Reduction of mitochondrial Zn2+ due to upregulation of ZIP7 accounts for the inhibition of the PINK1/Parkin pathway. Prevention of ZIP7 upregulation is essential for the treatment of T2DM-induced cardiomyopathy. [ABSTRACT FROM AUTHOR]

Pulmonary fibrosis is a chronic interstitial lung disease with no curative therapeutic treatment, leading to significant mortality. The aims of this study were to investigate the regulatory mechanisms of mitophagy in the progression of pulmonary fibrosis. Through bioinformatics analysis, we identified the downregulation of long-chain fatty acyl-CoA synthetase 1 (ACSL1) as being associated with the severity of pulmonary fibrosis. A pulmonary fibrosis model was established through bleomycin (BLM) exposure both in vivo and in vitro. Mitoquinone (MitoQ) pretreatment significantly decreased redox damage, stabilized mitochondrial membrane potential (MMP), improved mitochondrial dynamics, and activated PINK1/Parkin-mediated mitophagy, thereby alleviating pulmonary fibrosis. In vitro, overexpression of ACSL1 mitigated mitochondrial damage and restored PINK1/Parkin-mediated mitophagy under BLM exposure. In contrast, ACSL1 inhibition exacerbated pulmonary fibrosis, and these adverse effects could not be reversed by MitoQ treatment. Taken together, our study reveals a novel mechanism underlying the pathogenesis of pulmonary fibrosis and suggests a potential therapeutic target for its treatment. [ABSTRACT FROM AUTHOR]

Asynchronous nuclear and cytoplasmic maturation in human oocytes is believed to cause morphological anomalies after controlled ovarian hyperstimulation. Vacuolar protein sorting 34 (VPS34) is renowned for its pivotal role in regulating autophagy and endocytic trafficking. To investigate its impact on oocyte development, oocyte‐specific knockout mice (ZcKO) are generated, and these mice are completely found infertile, with embryonic development halted at 2‐ to 4‐cell stage. This infertility is related with a disruption on autophagic/mitophagic flux in ZcKO oocytes, leading to subsequent failure of zygotic genome activation (ZGA) in derived 2‐cell embryos. The findings further elucidated the regulation of VPS34 on the activity and subcellular translocation of RAS‐related GTP‐binding protein 7 (RAB7), which is critical not only for the maturation of late endosomes and lysosomes, but also for initiating mitophagy via retrograde trafficking. VPS34 binds directly with RAB7 and facilitates its activity conversion through TBC1 domain family member 5 (TBC1D5). Consistent with the cytoplasmic vacuolation observed in ZcKO oocytes, defects in multiple vesicle trafficking systems are also identified in vacuolated human oocytes. Furthermore, activating VPS34 with corynoxin B (CB) treatment improved oocyte quality in aged mice. Hence, VPS34 activation may represent a novel approach to enhance oocyte quality in human artificial reproduction. [ABSTRACT FROM AUTHOR]

Leber's hereditary optic neuropathy (LHON), a maternally inherited ocular disease, is predominantly caused by mitochondrial DNA (mtDNA) mutations. Mitochondrial tRNA variants are hypothesized to amplify the pathogenic impact of three primary mutations. However, the exact mechanisms remained unclear. In the present study, the synergistic effect of the tRNAGlu 14693A > G and ND6 14484T > C mutations in three Chinese families affected by LHON is investigated. The m.14693A > G mutation nearly abolishes the pseudouridinylation at position 55 of tRNAGlu, leading to structural abnormalities, decreased stability, aberrant mitochondrial protein synthesis, and increased autophagy. In contrast, the ND6 14484T > C mutation predominantly impairs complex I function, resulting in heightened apoptosis and virtually no induction of mitochondrial autophagy compared to control cell lines. The presence of dual mutations in the same cell lines exhibited a coexistence of both upregulated cellular stress responses to mitochondrial damage, indicating a scenario of autophagy and mutation dysregulation within these dual‐mutant cell lines. The data proposes a novel hypothesis that mitochondrial tRNA gene mutations generally lead to increased mitochondrial autophagy, while mutations in genes encoding mitochondrial proteins typically induce apoptosis, shedding light on the intricate interplay between different genetic factors in the manifestation of LHON. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial dysfunction in the thyroid due to defective mitophagy has been observed in lymphocytic thyroiditis (LT). However, the effect of impaired mitophagy on the pathogenesis of LT is not well understood. The aim of this study is to investigate the role of mitophagy dysregulation in the thyroid gland. Methods: We analyzed RNA sequencing data of human thyroid glands with/without LT from Genotype-Tissue Expression (GTEx; n = 653) and performed RNA sequencing in thyroid glands of phosphatase and tensin homolog-induced putative protein kinase 1 (Pink1) knock-out and wild-type mice. We evaluated the phenotypic and histopathologic characteristics of the human (n = 16) and mouse thyroids. Additionally, we assessed cell proliferation, reactive oxygen species (ROS) production, and cytokine secretion of human thyroid epithelial cells (HTori-3) treated with PINK1 siRNA or a mitophagy inhibitor. Results: We found that expression of PINK1, a key regulator of mitophagy, was compromised in human thyroids with LT. Thyroid glands of Pink1-deficient mice exhibited increased inflammatory responses and nodular hyperplasia. Furthermore, mitophagy defects led to the production of pro-inflammatory cytokines and ROS in thyroid cells, resulting in immune cell recruitment. Notably, these mitophagy defects upregulated both the RNA expression and protein secretion of amphiregulin (AREG), an epidermal growth factor receptor (EGFR) ligand, in thyroid cells, while decreasing the protein expression of cAMP response element-binding protein (CREB), a transcription factor that suppresses AREG transcription. Finally, we demonstrated that aberrant cell proliferation in thyroid cells, driven by mitophagy defects, was mitigated after treatment with cetuximab, an EGFR inhibitor. Conclusions: In this study, we observed that mitophagy defects in the thyroid not only intensify inflammation through the accumulation of ROS, cytokine production, and immune cell recruitment but also contribute to hyperplasia via the EGFR pathway, facilitated by increased secretion of AREG from thyroid cells. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is widely recognized as the prevailing joint disease associated with aging. The ketogenic diet (KD) has been postulated to impede the advancement of various inflammatory ailments. β‐Hydroxybutyrate (βOHB), a prominent constituent of ketone bodies, has recently been proposed to possess crucial signaling capabilities. In this study, we propose to explore the role and mechanism of βOHB in OA. Tissue staining and inflammatory factor assay were employed to evaluate the impacts of KD and βOHB on OA rats. The oxidative stress conditions in chondrocytes were induced using tert‐butyl hydroperoxide (TBHP). The mechanisms were determined using the siRNA of hydroxycarboxylic acid receptor 2 (HCAR2), the antagonist of adenosine monophosphate‐activated protein kinase (AMPK), and the inhibitor of mitophagy. The administration of KD demonstrated a reduction in pathological damage to cartilage, as well as a decrease in plasma levels of inflammatory factors. Furthermore, it resulted in an increase in the concentration of βOHB in the blood and synovial fluid. In vitro experiments showed that βOHB facilitated mitophagy and adenosine triphosphate production. Besides, βOHB mitigated chondrocyte senescence, inflammatory factors secretion, extracellular matrix degradation, and apoptosis induced by TBHP. Subsequent investigations indicated that the protective effects of βOHB were no longer observed following the knockdown of HCAR2, the antagonist of AMPK, or the inhibitor of mitophagy. Moreover, in vivo studies suggested that βOHB played a protective role by targeting the HCAR2‐AMPK‐PINK1 axis. In conclusion, βOHB enhanced chondrocyte mitophagy through the HCAR2/AMPK/PINK1/Parkin pathway, offering a potential therapeutic approach for the treatment of OA. [ABSTRACT FROM AUTHOR]

Radiation-induced intestinal injury (RIII) constitutes a challenge in radiotherapy. Ionizing radiation (IR) induces DNA and mitochondrial damage by increasing reactive oxygen species (ROS). Sodium–glucose cotransporter 1 (SGLT1) is abundant in the gastrointestinal tract and the protective effects of inhibited SGLT1 in kidney and cardiovascular disease have been widely reported. However, the function of SGLT1 in RIII remains unclear. Herein, we reported that IR induced intestinal epithelial cell damage along with upregulation of SGLT1 in vivo and in vitro, which was alleviated by inhibition of SGLT1. Specifically, maintaining intestinal cell homeostasis was detected through cellular proliferation, apoptosis, and DNA damage assays, promoting epithelial regeneration and lifespan extension. Considering the importance of mitochondrial function in cell fate, we next confirmed that SGLT inhibition maintains mitochondrial homeostasis through enhanced mitophagy in intestinal epithelial cells. Finally, based on the bioinformatics analysis and cell validation, we demonstrated that inhibition of SGLT1 suppresses the PI3K/AKT/mTOR pathway to enhance mitophagy activation post-irradiation. In addition, we preliminarily demonstrate that SGLT inhibitors do not affect the radiosensitivity of tumors. Hence, our findings suggest that inhibition of SGLT is a promising therapeutic strategy to protect against RIII. To the best of our knowledge, this is the first report on the potential effect of SGLT1 inhibition in RIII. [Display omitted] • IR leads to intestinal epithelial cells damage along with upregulation of SGLT1. • Inhibition of SGLT1 can alleviate radiation induced intestinal injury by regulating mitophagy and oxidative stress. • Inhibition of SGLT1 enhances PINK1/parkin-dependent mitophagy through the PI3K/Akt/mTOR pathway. • SGLT1 could be a potential therapeutic target and pharmaceutical against radiation induced intestinal injury. [ABSTRACT FROM AUTHOR]

Oxidative stress plays a critical role in early brain injury (EBI) following subarachnoid hemorrhage (SAH). The small molecule ULK1 agonist, BL-918, demonstrated neuroprotective effects in other central nervous system diseases; however, its role in SAH has not yet been explored. This study aimed to evaluate whether BL-918 could provide neuroprotective effects in rats following SAH. An SAH model was established in Sprague-Dawley rats using endovascular perforation. BL-918 was administered intraperitoneally after SAH, while the ULK1 inhibitor SBI was given intraperitoneally prior to SAH modeling. PINK1 siRNA was administered into the lateral ventricle before SAH induction. The neuroprotective effects and mechanisms of BL-918 were assessed through SAH grading, brain water content measurement, blood-brain barrier permeability, neurobehavioral tests, Western blot, immunofluorescence, TUNEL staining, DHE staining, and transmission electron microscopy (TEM). After SAH, the expression levels of p-ULK1, PINK1, Parkin, and LC3Ⅱ increased, peaking at 24 h post-SAH. BL-918 treatment improved neurological function in rats, reduced brain water content and blood-brain barrier permeability, and exhibited anti-oxidative stress and anti-apoptotic effects. Western blot analysis revealed that BL-918 increased the expression of p-ULK1, PINK1, Parkin, LC3Ⅱ, Bcl-xl, and Bcl-2 while inhibiting the expression of Bax and Cleaved Caspase-3. Oxidative stress-related indicators showed that BL-918 alleviated oxidative stress. Immunofluorescence and TEM results demonstrated that BL-918 promoted mitophagy and preserved mitochondrial morphology. Furthermore, the positive effects of BL-918 were reversed by SBI and PINK1 siRNA, respectively. BL-918 improved both short-term and long-term neurological impairments in rats after SAH and reduced oxidative stress by promoting mitophagy, at least partially through the ULK1/PINK1/Parkin signaling pathway. [Display omitted] • p-ULK1 expression increased after SAH. • BL-918 treatment improved neurological function in rats after SAH. • BL-918 promoted mitophagy through the ULK1/PINK1/Parkin pathway to alleviate oxidative stress and apoptosis in rats after SAH. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is a neurodegenerative disorder marked by the loss of dopaminergic neurons and the formation of α-synuclein aggregates. Mitochondrial dysfunction and oxidative stress are pivotal in PD pathogenesis, with impaired mitophagy contributing to the accumulation of mitochondrial damage. Hederagenin (Hed), a natural triterpenoid, has shown potential neuroprotective effects; however, its mechanisms of action in PD models are not fully understood. We investigated the effects of Hed on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in SH-SY5Y cells by assessing cell viability, mitochondrial function, and oxidative stress markers. Mitophagy induction was evaluated using autophagy and mitophagy inhibitors and fluorescent staining techniques. Additionally, transgenic Caenorhabditis elegans (C. elegans) models of PD were used to validate the neuroprotective effects of Hed in vivo by focusing on α-synuclein aggregation, mobility, and dopaminergic neuron integrity. Hed significantly enhanced cell viability in 6-OHDA-treated SH-SY5Y cells by inhibiting cell death and reducing oxidative stress. It ameliorated mitochondrial damage, evidenced by decreased mitochondrial superoxide production, restored membrane potential, and improved mitochondrial morphology. Hed also induced mitophagy, as shown by increased autophagosome formation and reduced oxidative stress; these effects were diminished by autophagy and mitophagy inhibitors. In C. elegans models, Hed activated mitophagy and reduced α-synuclein aggregation, improved mobility, and mitigated the loss of dopaminergic neurons. RNA interference targeting the mitophagy-related genes pdr-1 and pink-1 partially reversed these benefits, underscoring the role of mitophagy in Hed's neuroprotective actions. Hed exhibits significant neuroprotective effects in both in vitro and in vivo PD models by enhancing mitophagy, reducing oxidative stress, and mitigating mitochondrial dysfunction. These findings suggest that Hed holds promise as a therapeutic agent for PD, offering new avenues for future research and potential drug development. [Display omitted] • Hederagenin (Hed) enhances mitophagy in SH-SY5Y cells and C. elegans. • Hed protects mitochondria and decreases oxidative stress via mitophagy induction. • Hed reduces α-synuclein aggregation and improves mobility in NL5901 worms. • Hed reduces the loss of neurons and improves mobility in 6-OHDA-induced BZ555 worms. • Hed exhibits neuroprotection via activating mitophagy through Pdr-1 and pink-1 genes. [ABSTRACT FROM AUTHOR]

Cerebral ischemia-reperfusion injury (CI/RI) is a complex process leading to neuronal damage and death, with mitophagy implicated in its pathogenesis. However, the significance of mitophagy in CI/RI remains debated. We hypothesized that TRIM25 reduces ATAD3A expression by ubiquitinating ATAD3A, promoting mitophagy via the PINK1/Parkin pathway, and aggravating CI/RI. Rat middle cerebral artery occlusion (MCAO) followed by reperfusion and oxygen-glucose deprivation and reoxygenation (OGD/R) in PC12 cells were used as animal and cell models, respectively. To evaluate the success of the CI/R modeling, TTC and HE staining were employed. The determination of serum biochemical indexes was carried out using relative assay kits. The Western Blot analysis was employed to assess the expression of ATAD3A, TRIM25, as well as mitophagy-related proteins (PINK1, Parkin, P62, and LC3II/LC3I). The mRNA levels were detected using QRT-PCR. Mitochondrial membrane potential was assessed through JC-1 staining. Mitosox Red Assay Kit was utilized to measure mitochondrial reactive oxygen species levels in PC12 cells. Additionally, characterization of the mitophagy structure was performed using transmission electron microscopy (TEM). Our findings showed down-regulation of ATAD3A and up-regulation of TRIM25 in both in vivo and in vitro CI/RI models. Various experimental techniques such as Western Blot, JC-1 staining, Mitosox assay, Immunofluorescence assay, and TEM observation supported the occurrence of PINK1/Parkin signaling pathway-mediated mitophagy in both models. ATAD3A suppressed mitophagy, while TRIM25 promoted it during CI/RI injury. Additionally, the results indicated that TRIM25 interacted with and ubiquitinated ATAD3A via the proteasome pathway, affecting ATAD3A protein stability and expression. TRIM25 promoted Pink1/Parkin-dependent excessive mitophagy by destabilizing ATAD3A, exacerbating CI/RI. Targeting TRIM25 and ATAD3A may offer therapeutic strategies for mitigating CI/RI and associated neurological damage. [Display omitted] • We introduced a previously unidentified interaction between TRIM25 and ATAD3A. • This research highlighted the role of TRIM25 in ubiquitinating ATAD3A. • TRIM25 enhanced Pink1/Parkin-dependent mitophagy by destabilizing ATAD3A. • Ubiquitination of ATAD3A by TRIM25 worsens cerebral ischemia-reperfusion injury. [ABSTRACT FROM AUTHOR]

To investigate the protective effect of lanthanum chloride on kidney injury in chronic kidney disease and its mechanism. 1. Patients with CKD stage 2–5 were selected to analyze the effect of lanthanum-containing preparations on CKD. 2. Sixty healthy male Wistar rats were randomly divided into control group, model group, lanthanum chloride groups (0.03 ng/kg, 0.1 ng/kg, 0.3 ng/kg, q.3d., i.v.), and lanthanum carbonate group (0.3 g/kg, q.d., p.o.). The model group was given 2 % adenine suspension (200 mg/kg, q.d., p.o.) for the first two weeks, followed by adenine (200 mg/kg, b.i.d., p.o.) for 2 weeks, and all animals were sacrificed after eight weeks of administration. 3. The serum and kidneys of rats in each group were collected to detect the oxidative stress indicators and the expressions of LC3B-Ⅱ/Ⅰ, p62, Bcl-2, Bax, Caspase-3 and Cleaved Caspase-3. 4. Human renal tubular epithelial cells (HK-2 cells) were divided into control group, model group, lanthanum chloride group, pyrophosphate (PPI) group, chloroquine (CQ) group, rapamycin group, doxorubicin (DOX) group and N-acetyl-L-cysteine (NAC) group. The mitochondrial status, mitophagy and apoptosis levels were detected. 1.Lanthanum-containing preparations can significantly reduce the biochemical indexes of kidney injury in patients with CKD. 2. In the model group, the glomerular and renal tubular edema, the mitochondria were short and round, and the expression of LC3B-Ⅱ/Ⅰ and Bax increased, while the expression of P62, Bcl-2 and Caspase-3 decreased, and there was a significant improvement in the administration group, especially the 0.1 ng/kg group and lanthanum carbonate group. 3. In the HK-2 cell model group, mitochondrial membrane potential decreased, morphology changed and the results were reversed by lanthanum chloride. Lanthanum chloride may alter the morphology of nano-hydroxyapatite, thereby inhibiting its induced mitophagy and mitochondria-mediated apoptosis, and ultimately improve CKD renal injury effectively. [Display omitted] • Lanthanum chloride has a protective effect against kidney injury in CKD. • Nano-hydroxyapatite was found in both in vitro and in vivo CKD models, and it plays a major role in alleviating CKD. • Lanthanum chloride may change nano-hydroxyapatite morphology, inhibiting mitophagy and apoptosis, improving CKD renal injury. [ABSTRACT FROM AUTHOR]

Airway remodeling is an important pathological of airflow limitation in chronic obstructive pulmonary disease (COPD).However,its mechanism still needs to be further clarify. Animals:Healthy male C57BL/6 mice aged 4–6 weeks were randomly divided into control group and cigarette smoke(CS)group. Mice in the CS group were placed in a homemade glass fumigator, 5 cigarettes/time, 40 min/time, 4 times/day, 5 days/week, for 24 weeks. Mice in the control group were placed in a normal air environment.Cells:BEAS-2B cells were stimulated with 0.1%cigarette smoke extract(CSE).HE staining, immunohistochemical staining and Masson staining were used to observe the pathological of lung tissues, transmission electron microscopy was used to observe the structural of mitochondria in bronchial epithelial cells.Western blotting was used to detect the expression of STAT3,transforming growth factor-β1(TGF-β1),microtubule-associated protein 1A/1B-light chain3(LC3),PINK1,Parkin,E-cadherin,zonula occludens1(ZO-1),vimentin and snail family transcriptional inhibitor1 (Snail1),and MitoSOX Red was used to detect mitochondrial reactive oxygen species(mtROS). CS exposure causes lung parenchymal destruction and airway remodeling in mice.Compared to the control group,the expression of p-STAT3,TGF-β1 and EMT in the whole lung homogenate of the CS group was increased.Mitochondrial architecture disruption in bronchial epithelial cells of CS mice, with impaired PINK1-Parkin-dependent mitophagy.In vitro experiments showed that CSE exposure led to STAT3 activation, increased TGF-β1,EMT and enhanced PINK1-Parkin-mediated mitophagy.STAT3 inhibition reversed TGF-β1 upregulation induced by CSE and improved CSE-induced EMT and mitophagy.Inhibition of mitophagy improves EMT induced by CSE. Inhibition of mitophagy reduces STAT3-induced EMT. CS activates the STAT3,and activated STAT3 promotes EMT in bronchial epithelial cells by enhancing PINK1-Parkin-mediated mitophagy and TGF-β1 signaling.Moreover, activated STAT3 can promote EMT directly.This may be one of the mechanisms by which CS causes small airway remodeling in COPD. [Display omitted] • STAT3 and TGF-β1 were activated in CS-exposed mice. • CS exposure leads to mitochondrial structure damage accompanied by PINK1-Parkin-mediated mitophagy damage. • Inhibition of STAT3 reversed CSE-induced TGF-β1 and EMT. • STAT3 may induce EMT by promoting mitophagy. [ABSTRACT FROM AUTHOR]

Mitophagy plays a crucial role in maintaining the homeostasis of intervertebral disc (IVD). Early Growth Response 1 (EGR1), a conservative transcription factor, is commonly upregulated under oxidative stress conditions and participates in regulating cellular senescence, apoptosis, and inflammatory responses. However, the specific role of EGR1 in nucleus pulposus (NP) cell senescence and mitophagy remains unclear. In this study, through bioinformatics analysis and validation using human tissue specimens, we found that EGR1 is significantly upregulated in IVD degeneration (IDD). Further experimental results demonstrate that knockdown of EGR1 inhibits TBHP-induced NP cell senescence and mitochondrial dysfunction while promoting the activation of mitophagy. The protective effect of EGR1 knockdown on NP cell senescence and mitochondrion disappears upon inhibition of mitophagy with mdivi1. Mechanistic studies reveal that EGR1 suppresses NP cell senescence and mitochondrial dysfunction by modulating the PINK1-Parkin dependent mitophagy pathway. Additionally, EGR1 knockdown delays acupuncture-induced IDD in rats. In conclusion, our study demonstrates that under TBHP-induced oxidative stress, EGR1 knockdown mitigates NP cell senescence and mitochondrial dysfunction through the PINK1-Parkin dependent mitophagy pathway, thereby alleviating IDD. [Display omitted] • Knocking down EGR1 inhibits TBHP-induced nucleus pulposus cell senescence. • Knocking down EGR1 promotes mitophagy. • Knocking down EGR1 inhibits nucleus pulposus cell senescence by activating PINK1-Parkin-regulated mitophagy. [ABSTRACT FROM AUTHOR]

Mutations in the SLC1A4 transporter lead to neurodevelopmental impairments, spastic tetraplegia, thin corpus callosum and microcephaly in children. SLC1A4 catalyses obligatory amino acid exchange between neutral amino acids, but the physiopathology of SLC1A4 disease mutations and progressive microcephaly remain unclear. Here, we examined the phenotype and metabolic profile of three Slc1a4 mouse models: a constitutive Slc1a4-knockout mouse; a knock-in mouse with the major human Slc1a4 mutation (Slc1a4-K256E); and a selective knockout of Slc1a4 in brain endothelial cells (Slc1a4tie2-cre). We show that Slc1a4 is a bona fide L- serine transporter at the blood–brain barrier (BBB) and that acute inhibition or deletion of Slc1a4 leads to a decrease in serine influx into the brain. This results in microcephaly associated with decreased L- serine content in the brain, accumulation of atypical and cytotoxic 1-deoxysphingolipids, neurodegeneration, synaptic and mitochondrial abnormalities and behavioural impairments. Prenatal and early postnatal oral administration of L- serine at levels that replenish the serine pool in the brain rescued the observed biochemical and behavioural changes. Administration of L- serine until the second postnatal week also normalized brain weight in Slc1a4-E256K mice. Our observations suggest that the transport of 'non-essential' amino acids from the blood through the BBB is at least as important as that of essential amino acids for brain metabolism and development. We propose that SLC1A4 mutations cause a BBB aminoacidopathy with deficits in serine import across the BBB, required for optimal brain growth, leading to a metabolic microcephaly, which may be amenable to treatment with L- serine. [ABSTRACT FROM AUTHOR]

Heat shock protein 90 (HSP90) is recognized for its protective effects against heat stress damage; however, the specific functions and underlying molecular mechanisms of HSP90 in heat-stressed cardiomyocytes remain largely unexplored, particularly in tropical species. In our study, Wenchang chickens (WCCs) were classified into two groups: the heat stress survival (HSS) group and the heat stress death (HSD) group, based on their survival following exposure to heat stress. Heat stress resulted in significant cardiomyocyte damage, mitochondrial dysfunction, and apoptosis in the HSD group, while the damage was less pronounced in the HSS group. We further validated these findings in primary cardiomyocytes derived from Wenchang chickens (PCWs). Additionally, heat stress was found to upregulate Pink1/Parkin-mediated mitophagy, which was accompanied by an increase in HSP90 expression in both cardiomyocytes and PCWs. Our results demonstrated that HSP90 overexpression enhances PINK1/Parkin-mediated mitophagy, ultimately inhibiting apoptosis and oxidative stress in heat-stressed PCWs. However, the application of Geldanamycin (GA) reversed these effects. Notably, we discovered that HSP90 interacts with Beclin-1 through mitochondrial translocation and directly regulates mitophagy levels in PCWs. In summary, we have elucidated a novel role for HSP90 and mitophagy in regulating heat stress-induced acute cardiomyocyte injury. [ABSTRACT FROM AUTHOR]

Although significant progress has been made, there is still an urgent need to develop more effective therapies for neurodegenerative diseases (NDs). Recently, mitophagy activation has garnered significant interest as a potential therapeutic target for NDs. There have been advances in understanding how mitophagy functions and its specificity in different cell types, particularly in the central nervous system (CNS). Recent mechanistic insights, combined with the disease-relevant models, enable the rational design and development of mitophagy-activating drugs for the CNS. Mitophagy, the selective degradation of mitochondria, is impaired in many neurodegenerative diseases (NDs), resulting in an accumulation of dysfunctional mitochondria and neuronal damage. Although enhancing mitophagy shows promise as a therapeutic strategy, the clinical significance of mitophagy activators remains uncertain due to limited understanding and poor representation of mitophagy in the central nervous system (CNS). This review explores recent insights into which mitophagy pathways to target and the extent of modulation necessary to be therapeutic towards NDs. We also highlight the complexities of mitophagy in the CNS, highlighting the need for disease-relevant models. Last, we outline crucial aspects of in vitro models to consider during drug discovery, aiming to bridge the gap between preclinical research and clinical applications in treating NDs through mitophagy modulation. [ABSTRACT FROM AUTHOR]

Photoperiod is a pivotal factor in affecting testicular function and spermatogenesis in seasonal‐breeding animals. Mitophagy is essential for spermatogenesis, but its association with seasonal photoperiods has not been studied extensively. To explore this, we exposed male Brandt's voles (Lasiopodomys brandtii) to long‐photoperiod (LP, 16 h/day) and short‐photoperiod (SP, 8 h/day) conditions from their embryonic stages. Our results indicated that testis weight, volume, and relative testes weight were all significantly increased in LP compared to SP. Additionally, blood testosterone levels were markedly higher in LP than SP. Histological examination revealed that seminiferous diameter and epithelium thickness were greater in LP, with an increased abundance of germ cell types and cell numbers compared to SP. RT‐qPCR analysis showed that mitophagy‐promoting genes, such as Pink1, Prkn, Tomm7, Mnf2, Lc3, Optn, Gabarap, and Nbr1 were all upregulated in LP. Fluorescence in situ hybridization indicated that Pink1 expression was present in spermatogonia in SP, while in LP, Pink1 expression extended to almost all germ cell types with significantly higher mean optical density. Prkn expression was found in all germ cell types in both LP and SP, with a significantly higher mean optical density of 10‐week‐old LP males. Transmission electron microscopy showed normal mitochondrial morphology with clear membranes in SP, while the LP group had reduced cristae in mitochondria and damaged mitochondria undergoing autophagy. This study suggests that mitophagy may be involved in the photoperiodic spermatogenesis in Brandt's voles, providing insights into the role of photoperiod in seasonal reproduction in wild animals. [ABSTRACT FROM AUTHOR]

Mitochondrial abnormalities in lung epithelial cells have been associated with chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke (CS) can induce alterations in the molecular pathways regulating mitochondrial function in lung epithelial cells. Recently, heated tobacco products (HTPs) have been marketed as harm reduction products compared with regular cigarettes. However, the effects of HTP emissions on human alveolar epithelial cell metabolism and on the molecular mechanisms regulating mitochondrial content and function are unclear. In this study, human alveolar epithelial cells (A549) were exposed to cigarette or HTP emissions in the form of liquid extracts. The oxygen consumption rate of differently exposed cells was measured, and mRNA and protein abundancy of key molecules involved in the molecular regulation of mitochondrial metabolism were assessed. Furthermore, we used a mitophagy detection probe to visualize mitochondrial breakdown over time in response to the extracts. Both types of extracts induced increases in basal-, maximal- and spare respiratory capacity, as well as in cellular ATP production. Moreover, we observed alterations in the abundancy of regulatory molecules controlling mitochondrial biogenesis and mitophagy. Mitophagy was not significantly altered in response to the extracts, as no significant differences compared to vehicle-treated cells were observed. • cigarette smoke extract (CSE) and heated tobacco product extract (HTPE) induce an increase in cellular respiration in human alveolar epithelial cells. • CSE and HTPE affect the transcriptional program driving mitochondrial biogenesis. • Mitophagy was not induced by CSE or HTPE treatment. • Our study suggests a similar impact of cigarette and HTP emission on mitochondrial energy metabolism and on the molecular mechanisms regulating mitochondrial activity and content. [ABSTRACT FROM AUTHOR]

Objective(s): This study aimed to investigate the effect of 8-week high-intensity interval training (HIIT) on lactate-induced mitophagy in the hippocampus of rats with type 2 diabetes. Materials and Methods: 28 Wistar male rats were divided into four groups randomly: (i) control (Co), (ii) exercise (EX), (iii) type 2 diabetes (T2D), and (iv) type 2 diabetes + exercise (T2D + Ex). The rats in the T2D and T2D + Ex groups were fed a high-fat diet for two months, then a single dose of STZ (35 mg/kg) was injected to induce diabetes. The EX and T2D + Ex groups performed 4-10 intervals of treadmill running at 80-100% of Vmax. Serum and hippocampal levels of lactate, as well as hippocampal levels of monocarboxylate transported (MCT2), sirtuin1 (SIRT1), forkhead box protein O (FOXO3), light chain 3 (LC3), PTEN-induced kinase 1 (PINK1), parkin, beta-amyloid (Aβ), hyperphosphorylated tau protein (TAU), Malondialdehyde (MDA), and antioxidant enzymes were measured. One-way ANOVA and Tukey post-hoc tests were used to analyze the data. Results: Serum and hippocampal levels of lactate as well as hippocampal levels of MCT2, SIRT1, FOXO3, LC3, PINK1, Parkin, and antioxidant enzymes were higher while hippocampal levels of Aβ, TAU, and MDA were lower in T2D+EX compared to T2D group (P-value<0.05) Conclusion: HIIT could improve mitophagy through Lactate-SIRT1-FOXO3-PINK1/Parkin signaling in the hippocampus of rats with T2D reducing the accumulation of Tau and Aβ, which may reduce the risk of memory impairments. [ABSTRACT FROM AUTHOR]

Objectives: Osteoarthritis (OA) is the most common chronic joint degenerative disease. Herein, we investigated long non-coding RNA Opa-interacting protein 5-antisense transcript 1's (OIP5-AS1) in regulating mitophagy during OA. Methods: RNA immunoprecipitation and RNA pull-down verified the relationship between molecules. Cell counting kit-8 detected cell viability. Enzyme-linked immunosorbent assay evaluated inflammatory cytokines secretion. Flow cytometry measured the contents of reactive oxygen species (ROS) and calcium. Immunofluorescence staining analysed TOMM20 and LC3B levels. JC-1 staining was adopted to measure mitochondrial membrane potential. The changes of mitophagy were analysed by transmission electron microscopy. Results: Lipopolysaccharide (LPS) treatment contributed to the decrease of chondrocyte viability, and calcium level and inhibited mitochondrial membrane potential, while elevating the secretion of inflammatory factors, ROS, and TOMM20 expression. OIP5-AS1 overexpression inhibited LPS-induced chondrocyte injury and activated mitophagy. OIP5-AS1 upregulated the peroxisome proliferator–activated receptor-γ (PPAR-γ) mRNA level to regulate adenosine monophosphate–activated protein kinase (AMPK)/v-akt murine thymoma viral oncogene homolog (Akt)/mammalian target of rapamycin (mTOR) signalling by interacting with FUS. PPAR-γ overexpression alleviated LPS-induced chondrocyte injury by activating AMPK/Akt/mTOR signalling. PPAR-γ knockdown reversed the promotion of OIP5-AS1 upregulation on mitophagy. Conclusions: OIP5-AS1 promotes PPAR-γ expression to activate the AMPK/Akt/mTOR signalling, thereby enhancing mitophagy and alleviating OA progression. [ABSTRACT FROM AUTHOR]

Plant pathogens cause devastating diseases, leading to serious losses to agriculture. Mechanistic understanding of pathogenesis of plant pathogens lays the foundation for the development of fungicides for disease control. Mitophagy, a specific form of autophagy, is important for fungal virulence. The role of cardiolipin, mitochondrial signature phospholipid, in mitophagy and pathogenesis is largely unknown in plant pathogenic fungi. The functions of enzymes involved in cardiolipin biosynthesis and relevant inhibitors were assessed using a set of assays, including genetic deletion, plant infection, lipidomics, chemical‐protein interaction, chemical inhibition, and field trials. Our results showed that the cardiolipin biosynthesis‐related gene MoGEP4 of the rice blast fungus Magnaporthe oryzae regulates growth, conidiation, cardiolipin biosynthesis, and virulence. Mechanistically, MoGep4 regulated mitophagy and Mps1‐MAPK phosphorylation, which are required for virulence. Chemical alexidine dihydrochloride (AXD) inhibited the enzyme activity of MoGep4, cardiolipin biosynthesis and mitophagy. Importantly, AXD efficiently inhibited the growth of 10 plant pathogens and controlled rice blast and Fusarium head blight in the field. Our study demonstrated that MoGep4 regulates mitophagy, Mps1 phosphorylation and pathogenesis in M. oryzae. In addition, we found that the MoGep4 inhibitor, AXD, displays broad‐spectrum antifungal activity and is a promising candidate for fungicide development. Summary Statement: This study demonstrated that MoGep4 regulates mitophagy, Mps1 activation and pathogenesis in Magnaporthe oryzae. Additionally, we found that the MoGep4 inhibitor, alexidine dihydrochloride, displays broad‐spectrum antifungal activity and is effective in disease control in the field. [ABSTRACT FROM AUTHOR]

Osteopenia and osteoporosis are among the most common metabolic bone diseases and represent major public health problems, with sufferers having an increased fracture risk. Diabetes is one of the most common diseases contributing to osteopenia and osteoporosis. However, the mechanisms underlying diabetes-induced osteopenia and osteoporosis remain unclear. Bone reconstruction, including bone formation and absorption, is a dynamic process. Large-conductance Ca2+-activated K+ channels (BK channels) regulate the function of bone marrow-derived mesenchymal stem cells, osteoblasts, and osteoclasts. Our previous studies revealed the relationship between BK channels and the function of osteoblasts via various pathways under physiological conditions. In this study, we reported a decrease in the expression of BK channels in mice with diabetes-induced osteopenia. BK deficiency enhanced mitochondrial Ca2+ and activated classical PINK1 (PTEN induced putative kinase 1)-PRKN/Parkin (parkin RBR E3 ubiquitin protein ligase)-dependent mitophagy, whereas the upregulation of BK channels inhibited mitophagy in osteoblasts. Moreover, SLC25A5/ANT2 (solute carrier family 25 (mitochondrial carrier, adenine nucleotide translocator), member 5), a critical inner mitochondrial membrane protein participating in PINK1-PRKN-dependent mitophagy, was also regulated by BK channels. Overall, these data identified a novel role of BK channels in regulating mitophagy in osteoblasts, which might be a potential target for diabetes-induced bone diseases. Abbreviations: AGE, advanced glycation end products; Baf A1, bafilomycin A1; BK channels, big-conductance Ca2+-activated K+ channels; BMSCs, bone marrow-derived mesenchymal stem cells; BSA, bovine serum albumin; FBG, fasting blood glucose; IMM, inner mitochondrial membrane; ITPR1, inositol 1,4,5-trisphosphate receptor 1; MAM, mitochondria-associated ER membrane; OMM, outer mitochondrial membrane; PINK1, PTEN induced putative kinase 1; PPID/CyP-D, peptidylprolyl isomerase D (cyclophilin D); PRKN/PARK2, parkin RBR E3 ubiquitin protein ligase; ROS, reactive oxygen species; SLC25A5/ANT2, solute carrier family 25 (mitochondrial carrier, adenine nucleotide translocator), member 5; STZ, streptozotocin. [ABSTRACT FROM AUTHOR]

Myocardial injury induced by ischemia–reperfusion (I/R) remains a difficult clinical problem. However, the exact mechanisms underlying I/R‐induced have yet to be clarified. CARD9 is an important cytoplasmic‐binding protein. In this study, an immunocoprecipitation assay showed that SUMOylation of the CARD9 protein promoted the binding of CARD9 to HOXB5, but hindered the O‐GlcNAc glycosylation of HOXB5, a predicted transcription factor of Parkin and a key factor in mitophagy. O‐GlcNAc glycosylation is an important signal for translocation of proteins from the cytoplasm to the nucleus. CARD9 protein SUMOylation is regulated by PIAS3, which is related to I/R‐induced myocardial injury. Therefore, we propose that knockdown of PIAS3 inhibits SUMOylation of the CARD9 protein, facilitates the dissociation of CARD9 and HOXB5, which increases the O‐GlcNAc‐mediated glycosylation of HOXB5, while the resulting HOXB5 nuclear translocation promotes Parkin‐induced mitophagy and alleviates myocardial I/R injury. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is a progressive neurogenerative movement disorder characterized by dopaminergic cell death within the substantia nigra pars compacta (SNpc) due to the aggregation-prone protein α-synuclein. Accumulation of α-synuclein is implicated in mitochondrial dysfunction and disruption of the autophagic turnover of mitochondria, or mitophagy, which is an essential quality control mechanism proposed to preserve mitochondrial fidelity in response to aging and stress. Yet, the precise relationship between α-synuclein accumulation, mitochondrial autophagy, and dopaminergic cell loss remains unresolved. Here, we determine the kinetics of α-synuclein overexpression and mitophagy using the pH-sensitive fluorescent mito-QC reporter. We find that overexpression of mutant A53T α-synuclein in either human SH-SY5Y cells or rat primary cortical neurons induces mitophagy. Moreover, the accumulation of mutant A53T α-synuclein in the SNpc of rats results in mitophagy dysregulation that precedes the onset of dopaminergic neurodegeneration. This study reveals a role for mutant A53T α-synuclein in inducing mitochondrial dysfunction, which may be an early event contributing to neurodegeneration. [ABSTRACT FROM AUTHOR]

Background: Sepsis-induced myocardial injury (SIMI) is a severe complication of sepsis, contributing significantly to mortality. Mitochondrial dysfunction and dysregulated autophagy are implicated in SIMI pathogenesis. Long non-coding RNA MALAT1 has been associated with various diseases, including sepsis, but its role in SIMI remains unclear. Objective: This study aimed to investigate the role of lncRNA MALAT1 in SIMI, specifically in the regulation of mitochondrial autophagy. Methods: A sepsis-induced cardiomyopathy model was established in mice, and the cardiac tissues were analyzed. The expression of lncRNA MALAT1 was modulated and its effects on mitochondrial autophagy, myocardial injury, inflammation, and apoptosis were assessed. Furthermore, the interaction between MALAT1 and miR-146a was explored, as well as the involvement of the TLR4/NF-kB/MAPK signaling pathway. Results: Activation of mitochondrial autophagy by urolithin A (UA) alleviated SIMI, inflammation, and cardiac dysfunction. Downregulation of MALAT1 enhanced mitochondrial autophagy, stabilized the mitochondrial membrane potential, and inhibited mitochondrial reactive oxygen species (ROS) production, leading to improved cell viability and reduced myocardial injury. Furthermore, MALAT1 interacted with miR-146a, and their modulation influenced mitochondrial autophagy, myocardial injury, and inflammation. The TLR4/NF-kB/MAPK signaling pathway was implicated in these processes. Conclusion: Our findings suggest that lncRNA MALAT1 plays a crucial role in SIMI by modulating miR-146a-mediated mitochondrial autophagy and the TLR4/NF-kB/MAPK signaling pathway. These results provide new insights into the pathogenesis of SIMI and potential therapeutic targets. [ABSTRACT FROM AUTHOR]

To uncover the possible role of TRAF3IP3 in the progression of myocardial infarction (MI), clarify its role in mitophagy and mitochondrial function, and explore the underlying mechanism. GEO chip analysis, RT-qPCR, and LDH release assay were used to detect the expression of TRAF3IP3 in tissues and cells and its effects on cell damage. Immunostaining and ATP product assays were performed to examine the effects of TRAF3IP3 on mitochondrial function. Co-IP, CHX assays, Immunoblot and Immunostaining assays were conducted to determine the effects of TRAF3IP3 on mitophagy. TRAF3IP3 was highly expressed in IR rats and HR-induced H9C2 cells. TRAF3IP3 knockdown can alleviate H/R-induced H9C2 cell damage. In addition, TRAF3IP3 knockdown can induce mitophagy, thus enhancing mitochondrial function. We further revealed that TRAF3IP3 can promote the degradation of NEDD4 protein. Moreover, TRAF3IP3 knockdown suppressed myocardial injury in I/R rats. TRAF3IP3 blocks mitophagy to exacerbate myocardial injury induced by I/R via mediating NEDD4 expression. [ABSTRACT FROM AUTHOR]

The intake of high dietary fat has been correlated with the progression of age‐related macular degeneration (AMD), affecting the function of the retinal pigment epithelium through oxidative stress. A high‐fat diet (HFD) can lead to lipid metabolism disorders, excessive production of circulating free fatty acids, and systemic inflammation by aggravating the degree of oxidative stress. Deletion of the retinal G‐protein‐coupled receptor (RGR‐d) has been identified in drusen. In this study, we investigated how the RGR‐d exacerbates AMD‐like changes under oxidative stress, both in vivo and in vitro. Fundus atrophy became evident, at 12 months old, particularly in the RGR‐d + HFD group, and fluorescence angiography revealed narrower retinal vessels and a reduced perfusion area in the peripheral retina. Although rod electroretinography revealed decreasing trends in the a‐ and b‐wave amplitudes in the RGR‐d + HFD group at 12 months, the changes were not statistically significant. Mice in the RGR‐d + HFD group showed a significantly thinner and more fragile retinal morphology than those in the WT + HFD group, with disordered and discontinuous pigment distribution in the RGR‐d + HFD mice. Transmission electron microscopy revealed a thickened Bruch's membrane along the choriocapillaris endothelial cell wall in the RGR‐d + HFD mice, and the outer nuclear layer structure appeared disorganized, with reduced nuclear density. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated significantly lower levels of 25(OH)‐vitamin D3 metabolites in the RGR‐d + HFD group. Under oxidative stress, RGR‐d localized to the mitochondria and reduced the levels of the PINK1–parkin pathway. RGR‐d mice fed an HFD were used as a new animal model of dry AMD. Under high‐fat‐induced oxidative stress, RGR‐d accumulated in the mitochondria, disrupting normal mitophagy and causing cellular damage, thus exacerbating AMD‐like changes both in vivo and in vitro. [ABSTRACT FROM AUTHOR]

Mitochondria are crucial organelles that play a central role in cellular metabolism and programmed cell death in eukaryotic cells. Mitochondrial autophagy (mitophagy) is a selective process where damaged mitochondria are encapsulated and degraded through autophagic mechanisms, ensuring the maintenance of both mitochondrial and cellular homeostasis. Excessive programmed cell death in neurons can result in functional impairments following cerebral ischemia and trauma, as well as in chronic neurodegenerative diseases, leading to irreversible declines in motor and cognitive functions. Neuroinflammation, an inflammatory response of the central nervous system to factors disrupting homeostasis, is a common feature across various neurological events, including ischemic, infectious, traumatic, and neurodegenerative conditions. Emerging research suggests that regulating autophagy may offer a promising therapeutic avenue for treating certain neurological diseases. Furthermore, existing literature indicates that various small molecule autophagy regulators have been tested in animal models and are linked to neurological disease outcomes. This review explores the role of mitophagy in programmed neuronal death and its connection to neuroinflammation. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is a highly heterogeneous hematological malignancy that is currently incurable. Individualized therapeutic approaches based on accurate risk assessment are essential for improving the prognosis of MM patients. Nevertheless, current prognostic models for MM exhibit certain limitations and prognosis heterogeneity still an unresolved issue. Recent studies have highlighted the pivotal involvement of mitochondrial autophagy in the development and drug sensitivity of MM. This study seeks to conduct an integrative analysis of the prognostic significance and immune microenvironment of mitophagy-related signature in MM, with the aim of constructing a novel predictive risk model. GSE4581 and GSE47552 datasets were acquired from the Gene Expression Omnibus database. MM-differentially expressed genes (DEGs) were identified by limma between MM samples and normal samples in GSE47552. Mitophagy key module genes were obtained by weighted gene co-expression network analysis in the Cancer Genome Atlas (TCGA)-MM dataset. Mitophagy DEGs were identified by the overlap genes between MM-DEGs and mitophagy key module genes. Prognostic genes were selected through univariate Cox regression and least absolute shrinkage and selection operator (LASSO) analysis, and a risk model was subsequently constructed based on these prognostic genes. Subsequently, the MM samples were stratified into high- and low-risk groups based on their median risk scores. The validity of the risk model was further evaluated using the GSE4581 dataset. Moreover, a nomogram was developed using the independent prognostic factors identified from the risk score and various clinical indicators. Additionally, analyses were conducted on immune infiltration, immune scores, immune checkpoint, and chemotherapy drug sensitivity. The 17 mitophagy DEGs were obtained by intersection of 803 MM-DEGs and 1084 mitophagy key module genes. Five prognostic genes (CDC6, PRIM1, SNRPB, TOP2A, and ZNF486) were selected via LASSO and univariate cox regression analyses. The predictive performance of the risk model, which was constructed based on the five prognostic genes, demonstrated favorable results in both TCGA-MM and GSE4581 datasets as indicated by the receiver operating characteristic (ROC) curves. In addition, calibration curve, ROC curve, and decision curve analysis curve corroborated that the nomogram exhibited superior predictive accuracy for MM. Furthermore, immune analysis results indicated a significant difference in stromal scores of two risk groups categorized on median risk scores. And four immune checkpoints (CD274, CTLA4, LAG3, and PDCD1LG2) showed significant differences in different risk groups. The analysis of chemotherapy drug sensitivity revealed that etoposide and doxorubicin, which target TOP2A, exhibited superior treatment outcomes in the high-risk group. A novel prognostic model for MM was developed and validated, demonstrating significant potential in predicting patient outcomes and providing valuable guidance for personalized immunotherapy counseling. [ABSTRACT FROM AUTHOR]

Background and Purpose Experimental approach Key Results Conclusions and Implications Dihydro‐resveratrol (DHR), a polyphenol derivative, that has been demonstrated to suppress inflammation‐mediated injury. However, it is still unknown whether it has anti‐neuroinflammatory and neuroprotective effects, and a therapeutic action in Alzheimer's disease (AD).The anti‐inflammatory and anti‐Alzheimer's disease actions of dihydro‐resveratrol were investigated using lipopolysaccharide (LPS) and AD mice models, and primary microglial cells. The changes in behaviour in mice were detected by the Morris water maze test and open‐field test. Flow cytometry assay, western blotting, immunofluorescence assays and co‐immunoprecipitation were used to investigate the changes in the NLRP3 inflammasome activation and mitophagy.In this study, in vivo observations indicated that the administration of dihydro‐resveratrol (DHR) dramatically restored spatial learning, memory ability, autophagy and mitophagy, attenuated NLRP3 inflammasome activation, neuroinflammation and amyloid precursor protein pathology in LPS mice and AD mice. In addition, the inhibition of autophagy and mitophagy, or the activation of NLRP3 in vivo greatly abolished DHR‐generated therapeutic efficacy on neuroinflammation, amyloid precursor protein pathology and cognitive loss. Further examination indicated that the application of DHR after the LPS and ATP exposure significantly inhibited the NLRP3 inflammasome activation, neuroinflammation and enhanced autophagic and mitophagic activation in microglia. Additionally, in vitro results show that DHR protects microglial cells against LPS and ATP‐induced cytotoxicity by inhibiting NLRP3 inflammasome through activating Bnip3‐dependent mitophagy and ULK phosphorylation.In summary, these findings suggest that dihydro‐resveratrol (DHR) possesses potent anti‐neuroinflammatory property and can act as a potential therapeutic agent for the treatment of AD. [ABSTRACT FROM AUTHOR]

Cancer cells compensate with increasing mitochondria-derived vesicles (MDVs) to maintain mitochondrial homeostasis, when canonical MAP1LC3B/LC3B (microtubule associated protein 1 light chain 3 beta)-mediated mitophagy is lacking. MDVs promote the transport of mitochondrial components into extracellular vesicles (EVs) and induce tumor metastasis. Although HSP90 (heat shock protein 90) chaperones hundreds of client proteins and its inhibitors suppress tumors, HSP90 inhibitors-related chemotherapy is associated with unexpected metastasis. Herein, we find that HSP90 inhibitor causes mitochondrial damage but stimulates the low LC3-induced MDVs and the release of MDVs-derived EVs. However, why LC3 decreases and what is the transcriptional regulatory mechanism of MDVs formation under HSP90 inhibition remain unknown. Because TFEB (transcription factor EB) is the most important mitophagy transcription factor, and the HSP90 client HCFC1 (host cell factor C1) regulates TFEB transcription, there should be a hidden connection between TFEB, HCFC1 and HSP90 in MDVs formation. Our results support the idea that HSP90 N-terminal inhibition reduces TFEB transcription via decreased HSP90AA1-HCFC1 interaction, which prevents HCFC1 from binding to the TFEB proximal promoter region. Decreased TFEB transcription and consequently reduced LC3, ultimately promoted MDVs formation. Blocking MDVs formation with the microtubule inhibitor nocodazole (NOC) activates the HCFC1-TFEB-LC3 axis, weakens HSP90 inhibitors-induced MDVs and the release of MDVs-derived EVs, inhibits the growth of tumor cell spheres and primary liver tumors, and reduces the extravasation of cancer cells to secondary metastatic sites. Taken together, these data suggest that combination therapy should be used to reduce the metastatic risk of low TFEB-triggered-MDVs formation caused by HSP90 inhibitors.Abbreviation: ACIs: ATP-competitive inhibitors; BaFA1: bafilomycin A1; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; ChIP: chromatin immunoprecipitation; CHX: cycloheximide; CTD: C-terminal domain; EVs: extracellular vesicles; HCFC1: host cell factor C1; HSP90: heat shock protein 90; ILVs: intralumenal vesicles; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MD: middle domain; MDVs: mitochondria-derived vesicles; MQC: mitochondrial quality control; ΔΨm: mitochondrial membrane potential; MVBs: multivesicular bodies; NB: novobiocin; TEM: transmission electron microscopy; TFEB: transcription factor EB; TFs: transcription factors. NOC: nocodazole; NTD: N-terminal nucleotide binding domain; OCR: oxygen consumption rate; RFP: red fluorescent protein; ROS: reactive oxygen species; STA9090: Ganetespib; VPS35: VPS35 retromer complex component. [ABSTRACT FROM AUTHOR]

In sepsis, inflammation, and nutrient deficiencies endanger cellular homeostasis and survival. Autophagy is primarily a mechanism of cellular survival under fasting conditions. However, autophagy-dependent cell death, known as autophagic cell death, is proinflammatory and can exacerbate sepsis. Autophagy also regulates various types of non-inflammatory and inflammatory cell deaths. Non-inflammatory apoptosis tends to suppress inflammation, however, inflammatory necroptosis, pyroptosis, ferroptosis, and autophagic cell death lead to the release of inflammatory cytokines and damage-associated molecular patterns (DAMPs) and amplify inflammation. The selection of cell death mechanisms is complex and often involves a mixture of various styles. Similarly, protective autophagy and lethal autophagy may be triggered simultaneously in cells. How cells balance the regulatory mechanisms of these processes is an area of interest that is still under investigation. Therapies aimed at modulating autophagy are considered promising. Enhancing autophagy helps clear and recycle damaged organelles and reduce the burden of inflammatory processes while inhibiting excessive autophagy, which could prevent autophagic cell death. In this review, we introduce recent advances in research and the complex regulatory system of autophagy in sepsis. [ABSTRACT FROM AUTHOR]

Cisplatin-based chemotherapy serves as the standard of care for individuals with advanced stages of gastric cancer. Nevertheless, the emergence of chemoresistance in GC has detrimental impacts on prognosis, yet the underlying mechanisms governing this phenomenon remain elusive. Level of mitophagy and ferroptosis of GC cells were detected by fluorescence, flow cytometry, GSH, MDA, Fe2+ assays, and to explore the specific molecular mechanisms between NPR1 and cisplatin resistance by performing western blot and coimmunoprecipitation (co-IP) assays. These results indicates that NPR1 positively correlated with cisplatin-resistance and played a crucial part in conferring resistance to cisplatin in gastric cancer cells. Mechanistically, NPR1 affected levels of mitophagy and ferroptosis in human cisplatin-resistance GC cells with cisplatin treatment. Specifically, NPR1 inhibited mitophagy-dependent ferroptosis by reducing the ubiquitination-mediated degradation of PARL; moreover, NPR1 promoted PARL stabilization by disrupting the PARL–MARCH8 complex, which ultimately led to the development of chemoresistance in GC cells. Considering our findings, NPR1 appears to play an important role in chemotherapy for GC. NPR1 could potentially be used to overcome chemotherapy resistance. 1. NPR1 is highly expressed in cisplatin-resistant GC cells and promotes the cisplatin resistance. 2. According to IP-MS, NPR1 inhibits mitophagy-dependent ferroptosis through its downstream protein PARL. 3. NPR1 promoted PARL stabilization by disrupting the PARL–MARCH8 complex to inhibit the ubiquitination-mediated degradation of PARL. [ABSTRACT FROM AUTHOR]

PurposeMethodsResultsConclusionPancreatic β-cells play a critical role in regulating plasma insulin levels and glucose metabolism balance, with their dysfunction being a key factor in the progression of diabetes. This review aims to explore the role of autophagy, a vital cellular self-maintenance process, in preserving pancreatic β-cell functionality and its implications in diabetes pathogenesis.We examine the current literature on the role of autophagy in β-cells, highlighting its function in maintaining cell structure, quantity, and function. The review also discusses the effects of both excessive and insufficient autophagy on β-cell dysfunction and glucose metabolism imbalance. Furthermore, we discuss potential therapeutic agents that modulate the autophagy pathway to influence β-cell function, providing insights into therapeutic strategies for diabetes management.Autophagy acts as a self-protective mechanism within pancreatic β-cells, clearing damaged organelles and proteins to maintain cellular stability. Abnormal autophagy activity, either overactive or deficient, can disrupt β-cell function and glucose regulation, contributing to diabetes progression.Autophagy plays a pivotal role in maintaining pancreatic β-cell function, and its dysregulation is implicated in the development of diabetes. Targeting the autophagy pathway offers potential therapeutic strategies for diabetes management, with agents that modulate autophagy showing promise in preserving β-cell function. [ABSTRACT FROM AUTHOR]

Background: Overconsumption of retinoic acid (RA) or its analogues/derivatives has been linked to severe craniomaxillofacial malformations, such as cleft palate and midface hypoplasia. It has been noted that RA disturbed the proliferation and migration of embryonic palatal mesenchymal (EPM) cells in these malformations, yet the exact mechanisms underlying these disruptions remained unclear. Methods: A model of retinoic acid (RA)-induced cleft palate in fetal mice was successfully established. Histological alterations in the palate were evaluated using Hematoxylin and Eosin (H&E) staining and RNA in situ hybridization (RNAscope). Cellular proliferation levels were quantified via the Cell Counting Kit-8 (CCK-8) assay and EdU incorporation assay, while cell migration capabilities were investigated using wound healing and Transwell assays. Mitochondrial functions were assessed through Mito-Tracker fluorescence, mitochondrial reactive oxygen species (ROS) measurement, ATP level quantification, and mitochondrial DNA (mtDNA) copy number analysis. Differential gene expression and associated signaling pathways were identified through bioinformatics analysis. Alterations in the transcriptional and translational levels of Lhx6 and genes associated with mitophagy were quantified using quantitative PCR (qPCR) and Western blot analysis, respectively. Mitochondrial morphology and the mitochondrial autophagosomes within cells were examined through transmission electron microscopy (TEM). Results: Abnormal palatal development in mice, along with impaired proliferation and migration of human embryonic palatal mesenchymal (HEPM) cells, was associated with RA affecting mitochondrial function and concomitant downregulation of Lhx6. Knockdown of Lhx6 in HEPM cells resulted in altered cell proliferation, migration, and mitochondrial function. Conversely, the aberrant mitochondrial function, proliferation, and migration observed in RA-induced HEPM cells were ameliorated by overexpression of Lhx6. Subsequent research demonstrated that Lhx6 ameliorated RA-induced dysfunction in HEPM cells by modulating PINK1/Parkin-mediated mitophagy, thereby activating the MAPK signaling pathways. Conclusion: Lhx6 is essential for mitochondrial homeostasis via tuning PINK1/Parkin-mediated mitophagy and MAPK signaling pathways. Downregulation of Lhx6 by RA transcriptionally disturbs the mitochondrial homeostasis, which in turn leads to the proliferation and migration defect in HEPM cells, ultimately causing the cleft palate. [ABSTRACT FROM AUTHOR]

As one of the most prevalent malignancies, lung cancer displays considerable biological variability in both molecular and clinical characteristics. Lung cancer is broadly categorized into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) with the latter being most prevalent. The primary histological subtypes of NSCLC are lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). In the present work, we primarily extracted mRNA count data from a publicly accessible database followed by differentially expressed genes (DEGs) and differentially expressed mitophagy-related genes (DEMRGs) identification in case of both LUAD and LUSC cohorts. Next, we identified important DEMRGs via clustering approach followed by enrichment, survival, and mutational analyses. Lastly, the finalized prognostic biomarker was validated using wet-lab experimentations. Primarily, we obtained 986 and 1714 DEGs across LUAD and LUSC cohorts. Only 7 DEMRGs from both cohorts had significant membership values as indicated by the clustering analysis. Most significant pathway, Gene Ontology (GO)-biological process (BP), GO-molecular function (MF), GO-cellular compartment (CC) terms were macroautophagy, GTP metabolic process, magnesium ion binding, mitochondrial outer membrane. Among all, only TDRKH reported significant overall survival (OS) and 14% amplification across LUAD patients. Lastly, we validated TDRKH via immunohistochemistry (IHC) and semi-quantitative polymerase chain reaction (PCR). In conclusion, our findings advocate for the exploration of TDRKH and their genetic alterations in precision oncology therapeutic approaches for LUAD, emphasizing the potential for target-driven therapy and early diagnostics. [ABSTRACT FROM AUTHOR]

Glaucoma is a leading cause of irreversible visual impairment worldwide, characterized by the progressive death of retinal ganglion cells (RGCs). Deubiquitinating enzyme (DUB) inhibitors have shown promise as pharmacological interventions for neurodegenerative disorders. Our study focuses on the pan-DUB inhibitor PR-619 and its potential neuroprotective effects on RGCs through modulation of parkin-mediated mitophagy in experimental glaucoma models. The results show that impaired mitophagy exists in RGCs of our experimental glaucomatous model. In vivo, PR-619 increased RGCs survival in glaucomatous rats. In vitro, it protected RGCs against excitotoxicity and reduced ubiquitin-specific protease (USP) 15 expression. Additionally, PR-619 upregulated parkin expression, increased LC3-II/LC3-I ratios, and elevated LAMP1 levels, indicating enhanced mitophagy in vivo and in vitro. Moreover, numbers of mitophagosomes were increased in optic nerves of PR-619-treated ocular hypertensive rats in vivo. Furthermore, parkin knockdown negated the salutary effects of PR-619 and attenuated expression of parkin-dependent mitophagy effectors in RGCs subjected to glutamate excitotoxicity in vitro. Collectively, these findings implicate augmented parkin-mediated mitophagy as the mechanistic substrate underscoring the neuroprotective capacity of PR-619 in experimental glaucoma. These revelations engender the prospect that pharmacological agents or biotherapeutics augmenting parkin-mediated mitophagy may proffer viable therapeutic modalities for glaucomatous neurodegeneration characterized by impaired mitophagy. [ABSTRACT FROM AUTHOR]

Intervertebral disc degeneration (IVDD) is a primary contributor to low back pain and poses a considerable burden to society. However, the molecular mechanisms underlying IVDD remain to be elucidated. PR/SET domain 1 (PRDM1) regulates cell proliferation, apoptosis, and inflammatory responses in various diseases. Despite these regulatory functions, the mechanism of action of PRDM1 in IVDD remains unexplored. In this study, we investigated the role and underlying mechanisms of action of PRDM1 in IVDD progression. The expression of PRDM1 in nucleus pulposus (NP) tissues and NP cells (NPCs) was assessed using western blotting, immunohistochemistry, and immunofluorescence. The effects of PRDM1 on IVDD progression were investigated in vitro and in vivo. Mechanistically, mRNA sequencing, chromatin immunoprecipitation, and dual-luciferase reporter assays were performed to confirm that PRDM1 triggered CASP1 transcription. Our study demonstrated for the first time that PRDM1 expression was substantially upregulated in degenerated NP tissues and NPCs. PRDM1 overexpression promoted NPCs pyroptosis by inhibiting mitophagy and exacerbating IVDD progression, whereas PRDM1 silencing exerted the opposite effect. Furthermore, PRDM1 activated CASP1 transcription, thereby promoting NPCs pyroptosis in vitro. Notably, CASP1 silencing reversed the effects of PRDM1 on the NPCs. To the best of our knowledge, this study is the first to demonstrate that PRDM1 silencing inhibits NPCs pyroptosis by repressing CASP1 transcription, which may be a promising new therapeutic target for IVDD. [ABSTRACT FROM AUTHOR]

Diabetic encephalopathy (DE) is a severe complication of diabetes, but its pathogenesis remains unclear. This study aimed to investigate the roles and underlying mechanisms of high glucose (HG)- and advanced glycosylation end product (AGE)-induced oxidative stress (OS) in the cognitive decline in DE. The DE mouse model was established using a high-fat diet and streptozotocin, and its cognitive functions were evaluated using the Morris Water Maze, novel object recognition, and Y-maze test. The results revealed increased reactive oxygen species (ROS) generation, mitophagy inhibition, and decreased prohibitin 2 (PHB2) expression in the hippocampal neurons of DE mice and HG- or AGE-treated HT-22 cells. However, overexpression of PHB2 reduced ROS generation, reversed mitophagy inhibition, and improved mitochondrial function in the HG- or AGE-treated HT-22 cells and ameliorated cognitive decline, improved mitochondrial structural damage, and reversed mitophagy inhibition of hippocampal neurons in DE mice. Further analysis revealed that the Kelch-like ECH-associated protein 1 (Keap1)–nuclear factor erythroid 2-related factor 2 (Nrf2) pathway was involved in the HG- or AGE-mediated downregulation of PHB2 in HT-22 cells. These results demonstrate that HG- or AGE-induced OS inhibits the mitophagy of hippocampal neurons via the Keap1–Nrf2–PHB2 pathway, thereby contributing to the cognitive decline in DE. [ABSTRACT FROM AUTHOR]