Search Results (444)

Cadmium (Cd), a pervasive environmental and industrial toxicant, bioaccumulates and exerts severe detrimental effects on skeletal integrity across diverse animal species. Cd-induced bone injury manifests as osteoporosis, osteomalacia, and increased fracture risk, posing significant health and welfare concerns for wildlife and livestock inhabiting contaminated ecosystems. The pathogenesis hinges critically on the disruption of bone remodeling, a tightly regulated process orchestrated by osteoclasts (OCs) responsible for bone resorption and osteoblasts (OBs) responsible for bone formation. This comprehensive review synthesizes the latest mechanistic insights into how Cd disturbs OC and OB function and their intricate crosstalk, leading to net bone loss. Cd directly impairs OB proliferation, differentiation, and mineralization capacity through multiple pathways, including the inhibition of Wnt/β-catenin signaling, induction of oxidative stress and mitochondrial dysfunction, promotion of apoptosis and senescence, and disruption of extracellular matrix protein synthesis. Simultaneously, Cd potently stimulates excessive OC formation and activity. It achieves this by upregulating the RANKL/OPG axis, enhancing reactive oxygen species (ROS) production which activates key OC transcription factors, modulating key signaling pathways, and promoting pro-osteoclastogenic inflammatory cytokine release from bone marrow and immune cells. Critically, Cd disrupts the vital communication between OBs and OCs, perturbing the coupling signals essential for balanced remodeling. Emerging evidence highlights roles for Cd-induced epigenetic modifications and autophagy/mitophagy flux alterations. This narrative review integrates the findings from in vivo animal models and in vitro cellular studies, providing potential therapeutic interventions and mitigation strategies for Cd-induced bone toxicity. Understanding these complex and interacting mechanisms provides a foundation for identifying potential therapeutic targets to mitigate Cd bone toxicity in animals and informs ecological risk assessment and management strategies in contaminated environments. Full article

Renal oncocytoma (RO) is a benign renal neoplasm characterized by dense accumulation of dysfunctional mitochondria possibly resulting from increased mitochondrial biogenesis and decreased mitophagy; however, the mechanisms controlling these mitochondrial changes are unclear. ROs harbor recurrent inactivating mutations in mitochondrial genes encoding the Electron Transport Chain (ETC) Complex I, and we hypothesize that Complex I loss in ROs directly impairs mitophagy. Our analysis of ROs and normal kidney (NK) tissues shows that a significant portion (8 out of 17) of ROs have mtDNA Complex I loss-of-function mutations with high variant allele frequency (>50%). ROs indeed exhibit reduced Complex I expression and activity. Analysis of the various steps of mitophagy pathway demonstrates that AMPK activation in ROs leads to induction of mitochondrial biogenesis, autophagy, and formation of autophagosomes. However, the subsequent steps involving lysosome biogenesis and function are defective, resulting in an overall inhibition of mitophagy. Inhibiting Complex I in a normal kidney cell line recapitulated the observed lysosomal and mitophagy defects. Our data suggest Complex I loss in RO results in defective mitophagy due to lysosomal loss and dysfunction. Full article

Various biomaterials are currently employed for dermal biostimulation and filling purposes, with hyaluronic acid (HA)-based fillers among those with the most favorable safety profile, albeit exhibiting a limited biostimulatory effect. This study suggests that hyaluronic acid and succinic acid (SA) can significantly induce beneficial effects on skin cells by targeting key aging hallmarks. Human dermal senescent fibroblasts and aged adipocytes were treated with HA + SA, and various aging characteristics were examined through gene expression analysis and microscopy staining. HA was found to stimulate autophagy gene expression, while SA modulated senescence-gene expression, and the combination of these compounds induced mitophagy in senescent fibroblasts. Additionally, the HA + SA promoted adipogenesis, increased IGF1, and decreased TNFA gene expression in aged adipocytes. Furthermore, the conditioned medium from adipocytes treated with HA + SA upregulated key dermal genes such as COL3A1 and EGF. The findings of this study suggest that HA and SA compounds can be used for the biostimulation of aged skin through the regulation of senescence-associated gene expression and cell communication between dermal fibroblasts and subcutaneous adipocytes. Full article

Organ functions generally decline with age, but the ovary is a prototypical organ that undergoes functional loss over time. Autophagy plays a crucial role in maintaining organ homeostasis, and age-related upregulation of the autophagy inhibitor protein, Rubicon, has been linked to cellular and tissue dysfunction. This review describes how granulosa cell autophagy supports follicular growth and oocyte selection and maturation by regulating cellular energy metabolism and protein quality control. We then introduce the role of selective autophagy, including mitophagy or lipophagy, in steroidogenesis and cellular remodeling during luteinization. In aged ovaries, Rubicon accumulation suppresses autophagic flux, leading to diminished oxidative-stress resilience and enhanced DNA damage. Moreover, impaired autophagy drives the accumulation of ATP citrate lyase, which correlates with poor oocyte quality and reduced ovarian reserve. Following fertilization, oocytes further upregulate autophagy to provide the energy required for blastocyst transition. Conversely, in infertility-related disorders, such as premature ovarian insufficiency, endometriosis, and polycystic ovary syndrome, either deficient or excessive autophagy contributes to disease pathogenesis. Both autophagy inhibitors (e.g., Rubicon) and activators (e.g., Beclin1) could be emerging as promising biomarkers for assessing ovarian autophagy status. Therapeutically, Rubicon inhibition by trehalose in aged ovaries and autophagy suppression by agents such as hydroxychloroquine in polycystic ovary syndrome and endometriosis hold potential. Establishing robust methods to evaluate ovarian autophagy will be essential for translating these insights into targeted treatments. Full article

Nanoplastics (NPs), an emerging class of environmental pollutants, are increasingly recognized for their potential to interfere with critical cellular processes. Autophagy, a conserved degradative pathway essential for maintaining cellular homeostasis and adaptation to stress, has recently become a focal point of nanotoxicology research. This review synthesizes current evidence on the interactions between NPs and autophagic pathways across diverse biological systems. Findings indicate that NPs can trigger autophagy as an early cellular response; however, prolonged exposure may lead to autophagic dysfunction, contributing to impaired cell viability and disrupted signaling. Particular attention is given to the physiochemical properties of NPs such as size, surface charge, and polymer type, which influence cellular uptake and intracellular trafficking. We also highlight key mechanistic pathways, including oxidative stress and mTOR modulation. Notably, most available studies focus almost exclusively on polystyrene (PS)-based NPs, with limited data on other types of polymers, and several reports lack comprehensive assessment of autophagic flux or downstream effects. In conclusion, a better understanding of NP–autophagy crosstalk—particularly beyond PS—is crucial to evaluate the real toxic potential of NPs and guide future research in human health and nanotechnology. Full article

Cocaine misuse induces microglial activation and neuroinflammation, contributing to neurodegeneration and behavioral impairments. Prior studies have shown that cocaine induces mitochondrial dysfunction, dysregulated mitophagy, and lysosomal impairment in microglia. Here, we investigated the therapeutic potential of N-acetylcysteine (NAC) in mitigating cocaine-induced microglial activation and neuroinflammation. Mouse primary microglial cells (MPMs) were pretreated with NAC (5 mM) for 1 h prior to cocaine exposure (10 µM, 24 h) and analyzed for markers of microglial activation, mitophagy, and lysosomal integrity using Western blot, Seahorse assays, lysosomal pH, and membrane potential measurements. In vivo, C57BL/6N mice received NAC (200 mg/kg, i.p.) 1 h before daily cocaine injections (20 mg/kg, i.p.) for 7 days. Behavioral assays (open field, novel object recognition) and brain biomarker analyses (frontal cortex, hippocampus) were performed. Cocaine exposure elevated CD11b, mitophagy markers (PINK1, PARK, and DLP1), and autophagy proteins (Beclin1, and p62), while impairing mitochondrial and lysosomal functions. NAC pretreatment restored mitochondrial and lysosomal function, reduced reactive oxygen species, and normalized protein expression. In vivo, NAC also alleviated cocaine-induced microglial activation and behavioral deficits. These findings highlight NAC as a promising therapeutic agent to counteract cocaine-mediated neuroinflammation and neurotoxicity. Full article

The mitochondrial regulator MNRR1 is reduced in several pathologies, including the mitochondrial heteroplasmic disease MELAS, and genetic restoration of its level normalizes the pathological phenotype. Here, we investigate the upstream mechanism that reduces MNRR1 levels. We have identified the hypoxic regulator HIF2α to bind the MNRR1 promoter and inhibit transcription by competing with RBPJκ. In MELAS cells, there is a pseudohypoxic state that transcriptionally induces HIF2α and stabilizes HIF2α protein. MELAS cybrids harboring the m.3243A > G mutation display reduced levels of prolyl hydroxylase 3 (PHD3), which contributes to the HIF2α stabilization. These results prompted a search for compounds that could increase MNRR1 levels pharmacologically. The screening of a 2400-compound library uncovered the antifungal drug nitazoxanide and its metabolite tizoxanide as enhancers of MNRR1 transcription. We show that treating MELAS cybrids with tizoxanide restores cellular respiration, enhances mitophagy, and, importantly, shifts heteroplasmy toward wild-type mtDNA. Furthermore, in fibroblasts from MELAS patients, the compound improves mitochondrial biogenesis, enhances autophagy, and protects from LPS-induced inflammation. Mechanistically, nitazoxanide reduces HIF2α levels by increasing PHD3. Chemical activation of MNRR1 is thus a potential strategy to improve mitochondrial deficits seen in MELAS. Finally, our data suggests a broader physiological pathway wherein two proteins, induced under severe (1% O2; HIF2α) and moderate (4% O2; MNRR1) hypoxic conditions, regulate each other inversely. Full article

Background/Objectives: Aging and its related disorders are important issues nowadays, and ROS overproduction is one of the primary contributors to this physio-pathological condition. In this regard, ascorbic acid is a strong antioxidant molecule and its anti-aging proprieties are well known. Our previous data demonstrated that Voghera sweet pepper (VP), a peculiar type of pepper cultivated in Italy, is particularly rich in ascorbic acid and displayed a potential anti-aging effect in both young and aged in vitro models, regulating oxidative stress and senescence/proliferation. Based on these data, the anti-aging effect mediated by the extract of the edible part of VP, in terms of regulation of specific cell death mechanisms, was evaluated in an in vitro model of both young and old Normal Human Dermal Fibroblasts (NHDF). Methods: Immunofluorescence analyses were performed to assess the expression levels of specific markers related to autophagy (p62, LC3b) and mitophagy (Pink1, Parkin), as well as the apoptotic marker caspase-3. In addition, transmission electron microscopy (TEM) was used to analyze cellular ultrastructure and to provide further morphological evidence of the extract’s impact. Results: Immunofluorescence analyses revealed that VP extract led to modulated expression levels of p62, LC3b, Pink1, and Parkin, along with a reduction in caspase-3 activity, indicating decreased apoptosis. TEM ultrastructural analysis supported these findings, showing morphological changes consistent with the modulatory effects of VP extract during aging. Conclusions: Based on these results, we may suppose that Voghera pepper (VP) is able to modulate different mechanisms of regulated cell death (RCD) in our in vitro aging model. Full article

Cortisol, the main glucocorticoid in teleost, plays a central role in mediating the physiological response to stress by regulating metabolism, immune function, and growth. While its transcriptional effects are well known, its role in modulating chromatin accessibility in fish skeletal muscle remains poorly understood. In this study, we investigated the epigenomic and transcriptomic changes induced by cortisol in a juvenile rainbow trout’s (Oncorhynchus mykiss) skeletal muscle using ATAC-seq and RNA-seq. Fish were treated with a single intraperitoneal dose of cortisol (10 mg/kg) or vehicle, and muscle samples were collected 3 h post-treatment. ATAC-seq analysis revealed a total of 163,802 differentially accessible regions (DARs), with an important enrichment of open regions near transcription start sites and promoters. A total of 1612 and 1746 differentially accessible genes (DAGs) were identified in the cortisol and control groups, respectively. Motif enrichment analysis identified 89 transcription factors to be significantly enriched, among which key stress-responsive regulators such as Fos, AP-1, FoxO1/3, Mef2a/b/c, Klf5/10, and ATF4 were prominently represented. RNA-seq analysis identified 4050 differentially expressed genes (DEGs), with 2204 upregulated genes involved in autophagy, mitophagy, and FoxO signaling, while 1864 downregulated genes were enriched in spliceosome and chromatin remodeling pathways. Integrative analysis revealed 174 overlapping genes between ATAC-seq and RNA-seq datasets, highlighting pathways linked to autophagy and ATP-dependent chromatin remodeling. Four selected DEGs (sesn1, sesn2, cullin3, samtor) were validated by qPCR, showing high concordance with transcriptomic data. These findings provide new insights into cortisol-mediated regulation of chromatin dynamics and gene expression in teleost skeletal muscle and underscore the importance of epigenetic mechanisms in fish stress responses. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder marked by neuronal loss, cognitive decline, and pathological hallmarks such as amyloid-beta (Aβ) plaques and tau neurofibrillary tangles. Recent evidence highlights autophagy as a pivotal mechanism in cellular homeostasis, mediating the clearance of misfolded proteins and damaged organelles. However, impaired autophagy contributes significantly to AD pathogenesis by disrupting proteostasis, exacerbating neuroinflammation, and promoting synaptic dysfunction. This review aims to scrutinize the intricate relationship between autophagy dysfunction and AD progression, explaining key pathways including macroautophagy, chaperone-mediated autophagy (CMA), and selective autophagy processes such as mitophagy and aggrephagy. This further extends the discussion beyond the central nervous system, evaluating the role of hepatic autophagy in Aβ clearance and systemic metabolic regulation. An understanding of autophagy’s involvement in AD pathology via various mechanisms could give rise to a novel therapeutic strategy targeting autophagic modulation to mitigate disease progression in the future. Full article

The pathogenesis of psoriasis is complex and many specific immunopathogenic mechanisms still remain unclear. Our goal was to identify novel pathways involved in the pathogenesis of psoriasis by analyzing differentially expressed genes, and to conduct pathway and cluster analysis by comparing lesional and non-lesional skin with healthy controls. Accordingly, 2 mm punch biopsies were taken from lesional elbow skin and non-affected adjacent skin of 23 patients with plaque-type psoriasis and from the elbow skin of 25 healthy controls. Differentially expressed genes were analyzed through RNA sequencing, and gene set enrichment analysis was used to analyze biological pathways. Our results showed downregulation of the pathway clusters “Mitophagy” and “Respiratory Electron Transport” when comparing both lesional and non-lesional skin to control skin. The pathway “Signaling by ROBO receptors” was downregulated in all three comparisons. Conversely, pathways relating to SUMOylation were upregulated when comparing lesional skin to both non-lesional and control skin, and those relating to the synthesis of PIPs at the early endosome membrane were found to be upregulated in lesional skin compared to control skin. The dysregulation of pathways relating to mitophagy (involved in the removal of damaged mitochondria), complex I biogenesis (a component of the mitochondrial respiratory chain), signaling by ROBO receptors (important for cell migration), and the synthesis of PIPs at the early endosome membrane (with a pivotal role in endocytic pathways and autophagy) suggests their potential role in psoriasis. Further research into the mechanisms of these dysregulated pathways, along with confirmation of protein expression levels, is necessary to validate their roles in psoriasis pathogenesis. Full article

The crosstalk between autophagy and oxidative stress is a cornerstone of stem cell biology. These processes are tightly interwoven, forming a regulatory network that impacts stem cell survival, self-renewal, and differentiation. Autophagy, a cellular recycling mechanism, ensures the removal of damaged organelles and proteins, thereby maintaining cellular integrity and metabolic balance. Oxidative stress, driven by the accumulation of reactive oxygen species (ROS), can act as both a signalling molecule and a source of cellular damage, depending on its levels and context. The interplay between autophagy and oxidative stress shapes stem cell fate by either promoting survival under stress conditions or triggering senescence and apoptosis when dysregulated. Recent evidence underscores the bidirectional relationship between these processes, where autophagy mitigates oxidative damage by degrading ROS-generating organelles, and oxidative stress can induce autophagy as a protective response. This crosstalk is critical not only for preserving stem cell function but also for addressing age-related decline and enhancing regenerative potential. Understanding the molecular mechanisms that govern this interplay offers novel insights into stem cell biology and therapeutic strategies. This review delves into the intricate molecular dynamics of autophagy and oxidative stress in stem cells, emphasizing their synergistic roles in health, disease, and regenerative medicine applications. Full article

Mitochondrial dysfunction is a pivotal driver in the pathogenesis of acute kidney injury (AKI), chronic kidney disease (CKD), and congenital anomalies of the kidney and urinary tract (CAKUT). The kidneys, second only to the heart in mitochondrial density, rely on oxidative phosphorylation to meet the high ATP demands of solute reabsorption and filtration. Disrupted mitochondrial dynamics, such as excessive fission mediated by Drp1, exacerbate tubular apoptosis and inflammation in AKI models like ischemia–reperfusion injury. In CKD, persistent mitochondrial dysfunction drives oxidative stress, fibrosis, and metabolic reprogramming, with epigenetic mechanisms (DNA methylation, histone modifications, non-coding RNAs) regulating genes critical for mitochondrial homeostasis, such as PMPCB and TFAM. Epigenetic dysregulation also impacts mitochondrial–ER crosstalk, influencing calcium signaling and autophagy in renal pathology. Mitophagy, the selective clearance of damaged mitochondria, plays a dual role in kidney disease. While PINK1/Parkin-mediated mitophagy protects against cisplatin-induced AKI by preventing mitochondrial fragmentation and apoptosis, its dysregulation contributes to fibrosis and CKD progression. For instance, macrophage-specific loss of mitophagy regulators like MFN2 amplifies ROS production and fibrotic responses. Conversely, BNIP3/NIX-dependent mitophagy attenuates contrast-induced AKI by suppressing NLRP3 inflammasome activation. In diabetic nephropathy, impaired mitophagy correlates with declining eGFR and interstitial fibrosis, highlighting its diagnostic and therapeutic potential. Emerging therapeutic strategies target mitochondrial dysfunction through antioxidants (e.g., MitoQ, SS-31), mitophagy inducers (e.g., COPT nanoparticles), and mitochondrial transplantation, which mitigates AKI by restoring bioenergetics and modulating inflammatory pathways. Nanotechnology-enhanced drug delivery systems, such as curcumin-loaded nanoparticles, improve renal targeting and reduce oxidative stress. Epigenetic interventions, including PPAR-α agonists and KLF4 modulators, show promise in reversing metabolic reprogramming and fibrosis. These advances underscore mitochondria as central hubs in renal pathophysiology. Tailored interventions—ranging from Drp1 inhibition to mitochondrial transplantation—hold transformative potential to mitigate kidney injury and improve clinical outcomes. Additionally, dietary interventions and novel regulators such as adenogens are emerging as promising strategies to modulate mitochondrial function and attenuate kidney disease progression. Future research should address the gaps in understanding the role of mitophagy in CAKUT and optimize targeted delivery systems for precision therapies. Full article

Cold-inducible RNA-binding protein (CIRBP) has been reported to be involved in various cellular functions by regulating programmed cell death (PCD). However, the specific mechanism and function of CIRBP in regulating mitochondrial autophagy are still unclear. In this study, we found that CIRBP induced mitophagy through the AMPK/mTOR pathway to improve the function of yak cumulus cells (YCCs). We observed that low temperatures (32 °C) activated autophagy, increased E2 and P4 secretion, and up-regulated CIRBP expression. CIRBP overexpression activated mitophagy in YCCs, promoted cumulus diffusion, enhanced E2 and P4 synthesis and secretion, and inhibited apoptosis. CIRBP overexpression significantly attenuated the dysfunction of YCCs induced by the inhibition of mitophagy, whereas the activation of mitophagy exerted the same effect as CIRBP overexpression. DOX HCL is an AMPK/mTOR pathway inhibitor. CIRBP overexpression can successfully alleviate the inhibition of mitophagy caused by DOX HCL inhibiting the AMPK/mTOR pathway and can significantly enhance the mitophagy induced by AMPK/mTOR pathway activation in YCCs. Furthermore, we found that the increased expression of CIRBP protein alleviated the apoptosis caused by AKT pathway activation. In summary, CIRBP promoted mitophagy by activating AMPK/mTOR pathway, thereby promoting the synthesis and secretion of steroid hormones and cumulus diffusion in YCCs and enhancing YCCs survival through activating autophagy and AKT signaling pathway, and then improve the function of YCCs. Our research provided new perspectives on CIRBP’s regulation of cell death and highlighted its potential role in female reproductive systems. Full article

In older adults with reduced physical performance, an increase in the labile iron pool within skeletal muscle is observed. This accumulation is associated with an altered expression of mitochondrial quality control (MQC) markers and increased mitochondrial DNA damage, supporting the hypothesis that impaired MQC contributes to muscle dysfunction during aging. The autophagy–lysosome system plays a critical role in MQC by tagging and engulfing proteins and organelles for degradation in lysosomes. The endolysosomal system is also instrumental in transferrin recycling, which, in turn, regulates cellular iron uptake. In the neuromuscular system, the autophagy–lysosome system supports the structural integrity of neuromuscular junctions, and its dysfunction contributes to muscle atrophy. While MQC was thought to protect against iron-induced cell death, the discovery of ferroptosis, a form of iron-dependent cell death, has highlighted a complex interplay between MQC and iron-inflicted damage. Ferritinophagy, the autophagic degradation of ferritin, if overactivated, can induce ferroptosis. Alternatively, aging may impair ferritinophagy, leading to ferritin accumulation and the release of toxic labile iron under stress, exacerbating oxidative damage and cellular senescence. Physical activity supports muscle health also by preserving mitochondrial quantity and quality and enhancing bioenergetics. However, therapeutic strategies for preventing or reversing physical function decline in aging are still lacking due to the insufficient understanding of the underlying mechanisms. Unveiling how disruptions in iron homeostasis impact muscle quality in older adults may allow for the development of therapeutic strategies targeting iron handling to alleviate age-associated muscle decline. Full article