Recovery of the injured neural system through gene delivery to surviving neurons in Parkinson's disease

A critical unaddressed problem in Parkinson's disease is the lack of therapy that slows or hampers neurodegeneration. While medications effectively manage symptoms, they offer no long-term benefit because they fail to address the underlying neuronal loss. This highlights that the elusive goals of halting progression and restoring damaged neurons limit the long-term impact of current approaches. Recent clinical trials using gene therapy have demonstrated the safety of various vector delivery systems, dosages, and transgenes expressed in the central nervous system, signifying tangible and substantial progress in applying gene therapy as a promising Parkinson's disease treatment. Intriguingly, at diagnosis, many dopamine neurons remain in the substantia nigra, offering a potential window for recovery and survival. We propose that modulating these surviving dopamine neurons and axons in the substantia nigra and striatum using gene therapy offers a potentially more impactful therapeutic approach for future research. Moreover, innovative gene therapies that focus on preserving the remaining elements may have significant potential for enhancing long-term outcomes and the quality of life for patients with Parkinson's disease. In this review, we provide a perspective on how gene therapy can protect vulnerable elements in the substantia nigra and striatum, offering a novel approach to addressing Parkinson's disease at its core.

Nobiletin ameliorates monosodium urate-induced gouty arthritis in mice by enhancing AMPK/mTOR-mediated autophagy to inhibit NF-κB/NLRP3 inflammasome activation

BACKGROUND

Gouty arthritis (GA) is a common rheumatic disease caused by the release of monosodium urate crystal (MSU) deposits into joint space. Nobiletin is a polymethoxylated flavonoid isolated from citrus fruits and has many beneficial activities. This study aimed to elucidate the therapeutic efficacy of nobiletin in GA and to reveal its potential mechanisms.

METHODS

Phorbol-12-myristate-13-acetate (PMA)-differentiated THP-1 macrophages were primed with lipopolysaccharide (LPS) and then stimulated with MSU crystals in the presence or absence of nobiletin. Cell viability as well as the levels of proinflammatory cytokines, pathway-related proteins, NLRP3 inflammasomes, and autophagy-related proteins were evaluated. MSU was used to induce GA in mice. Hematoxylin-eosin staining was conducted to assess histological morphology changes. Immunofluorescence staining was performed to measure LC3 expression in THP-1 cells and ankle joint tissues.

RESULTS

For in vitro analysis, nobiletin reduced LPS and MSU-induced cell viability inhibition. Additionally, nobiletin inhibited inflammation and NF-κB/NLRP3 pathway in THP-1 cells. Moreover, nobiletin inhibited the activation of NLRP3 inflammasome by promoting AMPK/mTOR-mediated autophagy. For in vivo analysis, nobiletin attenuated MSU-induced GA in mice. Additionally, nobiletin suppressed inflammation and NF-κB/NLRP3 pathway and promoted tissue autophagy in GA mice.

CONCLUSION

Nobiletin prevents MSU-induced GA in mice by inhibiting NF-κB/NLRP3 inflammasome activation through AMPK/mTOR-mediated autophagy.

Effects of maternal smoking on inflammation, autophagy/mitophagy, and miRNAs in endothelial cells: Influence of newborn sex

Maternal smoking (MS) during pregnancy is linked to well-documented adverse health effects for the mother and foetus, however the role of fetal sex was largely overlooked. Primary cultures of male and female human umbilical vein endothelial cells (MHUVECs and FHUVECs, respectively) were used. IL-6, IL-8, and TNF-α levels were measured in HUVECs supernatant. The expression of genes and proteins (oestrogen receptors (ERs), Hsp90, Beclin-1, p62, LC3, LAMP-1 and Parkin), as well as the expression of miR-29a-3p, miR-29b-3p, miR-126-3p, miR-133a-3p, and miR-146a-5p were analysed in cells obtained from foetuses born to non-smoking and smoking mothers. In HUVECs from foetuses born to non-smoking mothers, Beclin-1 protein was higher in MHUVECs (1.8 fold increase), while Parkin, Hsp90 proteins, and miR-146a-5p were elevated in FHUVECs (2.2, 2.6, and 2.1 fold increase, respectively), with no other significant differences. MS amplified these sex differences, with specific effects based on foetus sex. FHUVECs obtained from foetus born to smoking mothers showed higher levels of IL-8 (1399.36 ± 123.96 pg/ml for FHUVECs vs 655.11 ± 215.94; pg/ml for MHUVECs; P < 0.001), Hsp90 gene and protein (3.3 and 2.6 fold increase), and ERβ protein and Beclin-1 gene (2.1, and 4.9 fold increase), and lower levels of miR-29b-3p, miR-133a-3p, and miR-146a-5p than MHUVECs (0.27, 0.68, and 0.1 fold change, respectively). This study shows that primary HUVECs from fetuses born to smoking mothers retain a memory of smoking effects, with sex differences in gene expression, miRNA profiles, and autophagic responses, suggesting that maternal smoking impacts endothelial cell physiology in a sex-dependent manner.

Betulinic acid enhances autopahgy to promote microglial M2 polarization and alleviate inflammation via AMPK-HDAC5-KLF2 signaling pathways in spinal cord injury

Spinal cord injury (SCI) leads to neuroinflammation and activates microglia, which are crucial contributors to neurological deficits. Betulinic acid (BA), a naturally occurring pentacyclic triterpenoid, has demonstrated effectiveness in treating inflammatory and neurological disorders. This study aims to explore the potential role and underlying mechanism of BA in modulating microglial activation and inflammation in the context of SCI. Using a mouse SCI model, we assessed motor recovery via Basso Mouse Scale (BMS) and neuronal survival via H&E/Nissl staining. Western blotting, qPCR, immunofluorescence, and flow cytometry were employed to analyze microglial polarization, autophagy, and AMPK-HDAC5-KLF2 signaling in vivo and in LPS-stimulated BV2 cells. Our findings reveal that BA significantly enhances functional recovery and reduces neuronal apoptosis following SCI. Furthermore, BA facilitates the phenotypic transition of microglia from the M1 to M2 phenotype, thereby decreasing inflammatory factors in both the SCI model and LPS-stimulated BV2 cells. BA treatment restores the disrupted autophagy flux in microglia induced by SCI or LPS, which in turn mitigates M1 polarization and inflammation. Mechanistically, BA restores autophagy flux by activating the AMPK-HDAC5-KLF2 axis, thereby shifting microglia from pro-inflammatory M1 to anti-inflammatory M2 phenotype.

Autophagy in Schwann cells: A potential pharmacotherapeutic target in diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes and is characterized by sensory and motor impairments resulting from neural injury. Schwann cells (SCs), which are important for peripheral nerve function, are compromised under hyperglycemic conditions, leading to impaired axonal regeneration and demyelination. Autophagy, a cellular degradation process, is essential for SC function and significantly influences DPN progression. This article highlights the significance of autophagy in SCs and its potential as a pharmacotherapeutic target in DPN. We discuss the mechanisms of autophagy in SCs, including the mammalian target of rapamycin, adenosine monophosphate-activated protein kinase, and phosphatase and tensin homolog-induced putative kinase/parkin pathways, and their dysregulation in DPN. This article also examines various natural products and chemical agents that modulate autophagy and enhance the efficacy of DPN treatment. These agents target key signaling pathways, such as adenosine monophosphate-activated protein kinase/mammalian target of rapamycin and demonstrate potential in promoting nerve regeneration and restoring SC function. The roles of exosomes, long non-coding RNA, and proteins in the regulation of autophagy have also been explored. In conclusion, targeting autophagy in SCs is a promising strategy for DPN treatment and offers new insights into therapeutic interventions. Further research is warranted to fully exploit these targets for clinical applications.

Unraveling rosmarinic acid anticancer mechanisms in oral cancer malignant transformation

Oral squamous cell carcinoma (OSCC) is expected to rise ca. 40 % by 2040. Rosmarinic acid (RA) has been recognized for its anticancer properties, although its role in OSCC has been neglected. This work exploits the activity of RA in 2D and 3D models of OSCC cells to compel a roadmap for its anticancer properties. The results demonstrated that RA significantly reduced cell mass and metabolic activity in a dose, time, and cell-type-dependent manner, predominantly in highly-invasive OSCC, without compromising normal mucosa in therapeutic doses. RA decreased mitochondria membrane potential and increased redox state, which was corroborated by pioneering observations on the metabolome landscape of OSCC cells (glutathione reduction and acetate and fumarate release). RA triggered autophagy, upregulating BNIP3 and BCNL1 and downregulating BIRC5. The upregulation of CADM1 and downregulation of VIM, CADM2, SNAIL1, and SOX9 highlighted the modulation of epithelial-mesenchymal transition and the remodeling of the extracellular matrix by the downregulation of MMP-2 and MMP-9. RA interacts with P-glycoprotein with the highest docking score of -6.4 kcal/mol. The HSC-3 cell surface charge decreased after RA treatment (-22.6 ± 0.3 mV vs. -26.3 ± 0.3 mV, p < 0.0001), suggesting a reversion of cell polarity and the impairment of invasion. RA also shrank the growth and the metabolic activity of multicellular tumor spheroids. Its modest protein binding with human saliva sheds light on its administration by the oromucosal route. Overall, this work supports the need for further research on the anticancer potential of RA in OSCC, either in monotherapy, combined with conventional treatments, or conveyed in nanosystems.

Autophagy is influenced by vitamin D3 level in people with HIV-1

BACKGROUND

Autophagy is the primary catabolic process responsible for degrading intracellular components and potentially harmful cytosolic entities by delivering them to lysosomes. Notably, this mechanism is crucial for controlling intracellular pathogens, with significant implications for both innate and adaptive immunity. In the context of HIV-1 infection, emerging evidence suggests that autophagy contributes to immune responses against the virus. Various compounds can modulate autophagy, among which vitamin D₃ is particularly effective due to its ability to prevent inflammation and slow HIV-1 disease progression. Indeed, vitamin D₃ contributes to regulating both innate and adaptive immunity, thereby modulating antiviral and antibacterial inflammatory responses. Importantly, vitamin D₃ deficiency is highly prevalent among people with HIV (PWH) and has been associated with an increased risk of severe disease progression.

RESULTS

In this study, we investigated the relationship between serum vitamin D₃ levels and the expression of autophagy markers in peripheral blood mononuclear cells from different categories of PWH: PWH under antiretroviral therapy (ART) with either normal vitamin D₃ levels or hypovitaminosis, and treatment-naïve PWH with either normal vitamin D₃ levels or hypovitaminosis. Our results show that low vitamin D₃ blood levels is associated with lower expression of the main factors involved in the autophagy mechanism, particularly in treatment-naïve PWH.

CONCLUSIONS

Our findings suggest that normal blood level of vitamin D₃ may play a crucial role in promoting autophagy in PWH. The observed differences in autophagy-related protein expression between ART-treated and untreated individuals underscore the intricate relationship between vitamin D₃ levels, ART exposure, and autophagic regulation. This is a preliminary exploration of the effects of vitamin D₃ on autophagy in PWH. Further studies are needed to deepen and explore the interplay between vitamin D₃ and autophagy in greater depth. A better understanding of these mechanisms could help to develop novel therapeutic strategies aimed at mitigating immune depletion and chronic inflammation, ultimately improving clinical outcomes for individuals living with HIV.

The imidazoline I2 receptor agonist 2-BFI enhances cytotoxic activity of hydroxychloroquine by modulating oxidative stress, energy-related metabolism and autophagic influx in human colorectal adenocarcinoma cell lines

Recently, interest in imidazoline receptors (IRs) has been increasing. Over the years, a growing number of studies have highlighted the therapeutic potential of ligands targeting these receptors, however, the potential role of imidazoline I2 receptor agonists in cancer treatment has not been thoroughly investigated. Colorectal cancer (CRC) is among the most prevalent and lethal forms of cancer worldwide. The complexity of CRC necessitates individualized approaches. One promising area of research within CRC therapy is the regulation of autophagy. Recent studies have explored the relationship between autophagy and cancer progression, revealing that autophagy modulation could be a potential strategy for CRC treatment. However, the mechanisms underlying autophagy regulation remain poorly understood. This study aimed to evaluate the effect of the imidazoline I2 receptor agonist, namely 2-(2-benzofuranyl)-2-imidazoline hydrochloride (2-BFI), on colorectal cancer cells, HT-29 and HCT-116 cell lines, particularly its impact when co-incubated with the autophagy inhibitor, hydroxychloroquine (HCQ). The results showed that 2-BFI synergistically increased the cytotoxic effect of HCQ by inducing oxidative stress and apoptosis. Furthermore, our investigation indicated impairment autophagic influx in colon cancer cells treated by 2-BFI. The comprehensive metabolomic analysis revealed significant alterations in key metabolic pathways including MAO activity, oxidative stress responses, energy-related metabolites and amino acids metabolism. Altogether, these findings demonstrate potential a new therapeutic strategy based on autophagy regulation and the selective induction of oxidative stress in colorectal cancer cells. Moreover, this study provides a foundation for further investigation into the therapeutic potential of imidazoline receptor agonists in cancer therapy.

Structure of the human autophagy factor EPG5 and the molecular basis of its conserved mode of interaction with Atg8-family proteins

The multi-step macroautophagy/autophagy process ends with the cargo-laden autophagosome fusing with the lysosome to deliver the materials to be degraded. The metazoan-specific autophagy factor EPG5 plays a crucial role in this step by enforcing fusion specificity and preventing mistargeting. How EPG5 exerts its critical function and how its deficiency leads to diverse phenotypes of the rare multi-system disorder Vici syndrome are not fully understood. Here, we report the first structure of human EPG5 (HsEPG5) determined by cryo-EM and AlphaFold2 modeling. Our structure revealed that HsEPG5 is constructed from helical bundles analogous to tethering factors in membrane trafficking pathways but contains a unique protruding thumb domain positioned adjacent to the atypical tandem LIR motifs involved in interaction with the GABARAP subfamily of Atg8-family proteins. Our NMR spectroscopic, molecular dynamics simulations and AlphaFold modeling studies showed that the HsEPG5 tandem LIR motifs only bind the canonical LIR docking site (LDS) on GABARAP without engaging in multivalent interaction. Our co-immunoprecipitation analysis further indicated that full-length HsEPG5-GABARAP interaction is mediated primarily by LIR1. Finally, our biochemical affinity isolation, X-ray crystallographic analysis, affinity measurement, and AlphaFold modeling demonstrated that this mode of binding is observed between Caenorhabditis elegans EPG-5 and its Atg8-family proteins LGG-1 and LGG-2. Collectively our work generated novel insights into the structural properties of EPG5 and how it potentially engages with the autophagosome to confer fusion specificity.ABBREVIATIONS: ATG: autophagy related; CSP: chemical shift perturbation; eGFP: enhanced green fluoresent protein; EM: electron microscopy; EPG5: ectopic P-granules 5 autophagy tethering factor; GST: glutathione S-transferase; HP: hydrophobic pocket; HSQC: heteronuclear single-quantum correlation; ITC: isothermal titration calorimetry; LDS: LC3 docking site; LIR: LC3-interacting region; MD: molecular dynamics; NMR: nuclear magnetic resonance; TEV: tobacco etch virus.

ESRRA (estrogen related receptor, alpha) induces ribosomal protein RPLP1-mediated adaptive hepatic translation during prolonged starvation

Protein translation is an energy-intensive ribosome-driven process that is reduced during nutrient scarcity to conserve cellular resources. During prolonged starvation, cells selectively translate specific proteins to enhance their survival (adaptive translation); however, this process is poorly understood. Accordingly, we analyzed protein translation and mRNA transcription by multiple methods in vitro and in vivo to investigate adaptive hepatic translation during starvation. While acute starvation suppressed protein translation in general, proteomic analysis showed that prolonged starvation selectively induced translation of lysosome and autolysosome proteins. Significantly, the expression of the orphan nuclear receptor, ESRRA (estrogen related receptor, alpha) increased during prolonged starvation and served as a master regulator of this adaptive translation by transcriptionally stimulating Rplp1 (ribosomal protein lateral stalk subunit P1) gene expression. Overexpression or siRNA knockdown of Esrra in vitro or in vivo led to parallel changes in Rplp1 gene expression, lysosome and macroautophagy/autophagy protein translation, and autophagy activity. Remarkably, we have found that ESRRA had dual functions by not only regulating transcription but also controlling adaptive translation via the ESRRA-RPLP1-lysosome-autophagy pathway during prolonged starvation.

Autophagy in Acute Lung Injury

Acute lung injury (ALI) is a critical condition marked by rapid-onset respiratory failure due to extensive inflammation and increased pulmonary vascular permeability, often progressing to acute respiratory distress syndrome (ARDS) with high mortality. Autophagy, a cellular degradation process essential for removing damaged organelles and proteins, plays a crucial role in regulating lung injury and repair. This review examines the protective role of autophagy in maintaining cellular function and reducing inflammation and oxidative stress in ALI. It underscores the necessity of precise regulation to fully harness the therapeutic potential of autophagy in this context. We summarize the mechanisms by which autophagy influences lung injury and repair, discuss the interplay between autophagy and apoptosis, and examine potential therapeutic strategies, including autophagy inducers, targeted autophagy signaling pathways, antioxidants, anti-inflammatory drugs, gene editing, and stem cell therapy. Understanding the role of autophagy in ALI could lead to novel interventions for improving patient outcomes and reducing mortality rates associated with this severe condition.

A FOX transcription factor phosphorylated for regulation of autophagy facilitates fruiting body development in Sclerotinia sclerotiorum

Autophagy is a recycling process by which eukaryotic cells degrade their own components, and the fruiting body (sexual structure) is a necessary structure for some plant pathogenic fungi to start the infection cycle. However, the transcriptional regulation of plant pathogenic fungal autophagy and autophagy regulating sexual reproduction remains elusive. Here, we provide the report linking autophagy transcription and fruiting body development in phytopathogenic fungi. The forkhead box transcription factor (FOX TF) SsFoxE2 in Sclerotinia sclerotiorum (Ss) binds to the promoters of ATG genes, thus promoting their transcription. SsFoxE2 is phosphorylated by AMP-activated protein kinase (AMPK) SsSnf1, and the phosphorylated SsFoxE2 interacts with (translationally controlled tumor protein) SsTctp1, leading to enhanced stability and ATG transcription activity of SsFoxE2. Importantly, the regulation of autophagy by SsFoxE2 affects the balance of the ubiquitination system and the early development of the fruiting body, which directly determines the occurrence and prevalence of plant disease. Furthermore, transcriptional binding of FOX TF to ATG gene promoters is conserved in phytopathogenic fungi. Taken together, our results bring new insights into pathogen initiation in phytopathogenic fungi and connect it to other autophagy-regulated processes in plant pathogens.

Autophagic stagnation: a key mechanism in kidney disease progression linked to aging and obesity

Autophagy, a critical intracellular degradation and recycling pathway mediated by lysosomes, is essential for maintaining cellular homeostasis through the quality control of proteins and organelles. Our research focused on the role of proximal tubular autophagy in the pathophysiology of aging, obesity, and diabetes. Using a novel method to monitor autophagic flux in kidney tissue, we revealed that age-associated high basal autophagy supports mitochondrial quality control and delays kidney aging. However, an impaired ability to upregulate autophagy under additional stress accelerates kidney aging. In obesity induced by a high-fat diet, lysosomal dysfunction disrupts autophagy, leading to renal lipotoxicity. Although autophagy is initially activated to repair organelle membranes and maintain proximal tubular cell integrity, this demand overwhelms lysosomes, resulting in "autophagic stagnation" characterized by phospholipid accumulation. Similar lysosomal phospholipid accumulation was observed in renal biopsies from elderly and obese patients. We identified TFEB-mediated lysosomal exocytosis as a mechanism to alleviate lipotoxicity by expelling accumulated phospholipids. Therapeutically, interventions such as the SGLT2 inhibitor empagliflozin and eicosapentaenoic acid restore lysosomal function and autophagic activity. Based on these findings, we propose a novel disease concept, "Obesity-Related Proximal Tubulopathy." This study underscores autophagic stagnation as a key driver of kidney disease progression in aging and obesity, offering insights into the pathophysiology of kidney diseases and providing a foundation for targeted therapeutic strategies.

FUT2-dependent fucosylation of LAMP1 promotes the apoptosis of colorectal cancer cells by regulating the autophagy-lysosomal pathway

Fucosyltransferase 2 (FUT2) is an enzyme that adds fucose to proteins or lipids via α-1,2-fucosylation in the intestinal mucosa. While FUT2 deficiency is linked to increased susceptibility to inflammatory bowel disease (IBD), its role in colorectal cancer (CRC) is unclear, and the molecular mechanisms involved remain largely unknown. We established an azoxymethane (AOM) and dextran sulfate sodium (DSS) model to induce CRC. FUT2 expression was assessed in human CRC tissues, AOM/DSS-induced mouse models, and CRC cell lines using qRT-PCR, western blotting, and UEA-I staining. FUT2 knockout (FUT2△IEC) mice were treated with AOM/DSS, and FUT2-overexpressing CRC cells were created to evaluate the effects of FUT2 on apoptosis in both in vitro and in vivo settings through Western blot analyses and functional assays. N-glycoproteomics, UEA-I chromatography, and co-immunoprecipitation were utilized to identify regulatory mechanisms and target fucosylated proteins. FUT2 expression and α-1,2-fucosylation were significantly decreased in CRC. FUT2 deficiency worsened AOM/DSS-induced CRC and reduced tumor apoptosis, while FUT2 overexpression induced apoptosis and inhibited proliferation in CRC cells and xenografts. Mechanistically, FUT2 appears to suppress autophagy by impairing lysosomal function and directly targeting and fucosylating LAMP1, contributing to lysosomal dysfunction. Our study reveals a fucosylation-dependent antitumor mechanism of FUT2 in CRC, suggesting potential therapeutic strategies for CRC treatment.

Host-directed therapy in diabetes and tuberculosis comorbidity toward global tuberculosis elimination

Host-directed therapy could potentially revolutionize tuberculosis control as an adjunct to traditional antibiotics for the treatment of tuberculosis disease and as a strategy to prevent disease progression following Mycobacterium tuberculosis infection. The growing type 2 diabetes pandemic is hampering tuberculosis control worldwide, as people with diabetes have an increased risk of developing tuberculosis disease as well as worse treatment outcomes. Pulmonary tuberculosis is characterized by an inflammatory response that can cause alveolar tissue destruction and cavitation, and this inflammation is exacerbated in people with tuberculosis-diabetes comorbidity. Thus, the reduction of the inflammatory response is a key goal of host-directed therapy to dampen immunopathology, but it is vital that the inflammatory response is not suppressed too much, or the immune system will not be able to react to M. tuberculosis and mycobacterial replication will intensify. Furthermore, the type I interferon response and host cell metabolism are further dysregulated in tuberculosis-diabetes comorbidity, likely contributing to poor treatment outcomes. Achieving the right balance in terms of modulating the inflammatory and immune responses, both quantitatively and temporally, is more complex in tuberculosis-diabetes comorbidity, and this population should be included specifically in clinical trials of new regimens. In this regard, mathematical modeling has a key role in elucidating which biologic pathways should be targeted in different people. Host-directed therapy for people with tuberculosis-diabetes comorbidity will reduce immunopathology and post-tuberculosis lung disease, as well as boost microbiologic cure and treatment outcomes, and thus help in the fight toward global tuberculosis elimination.

Autophagy and the peroxisome proliferator-activated receptor signaling pathway: A molecular ballet in lipid metabolism and homeostasis

Lipids, which are indispensable for cellular architecture and energy storage, predominantly consist of triglycerides (TGs), phospholipids, cholesterol, and their derivatives. These hydrophobic entities are housed within dynamic lipid droplets (LDs), which expand and contract in response to nutrient availability. Historically perceived as a cellular waste disposal mechanism, autophagy has now been recognized as a crucial regulator of metabolism. Within this framework, lipophagy, the selective degradation of LDs, plays a fundamental role in maintaining lipid homeostasis. Dysregulated lipid metabolism and autophagy are frequently associated with metabolic disorders such as obesity and atherosclerosis. In this context, peroxisome proliferator-activated receptors (PPARs), particularly PPAR-γ, serve as intracellular lipid sensors and master regulators of gene expression. Their regulatory influence extends to both autophagy and lipid metabolism, indicating a complex interplay between these processes. This review explores the hypothesis that PPARs may directly modulate autophagy within the realm of lipid metabolism, thereby contributing to the pathogenesis of metabolic diseases. By elucidating the underlying molecular mechanisms, we aim to provide a comprehensive understanding of the intricate regulatory network that connects PPARs, autophagy, and lipid homeostasis. The crosstalk between PPARs and other signaling pathways underscores the complexity of their regulatory functions and the potential for therapeutic interventions targeting these pathways. The intricate relationships among PPARs, autophagy, and lipid metabolism represent a pivotal area of research with significant implications for understanding and treating metabolic disorders.

DNA hypermethylation-induced suppression of ALKBH5 is required for folic acid to alleviate hepatic lipid deposition by enhancing autophagy in an ATG12-dependent manner

Nonalcoholic fatty liver disease (NAFLD) occurs when too much fat builds up in the liver. As a growing worldwide epidemic, NAFLD is strongly linked with multiple metabolic diseases including obesity, insulin resistance, and dyslipidemia. However, very few effective treatments are currently available. Folate, an essential B-group vitamin with important biological functions including DNA and RNA methylation regulation, has been shown to have a protective effect against NAFLD with its underlying mechanism remains largely unclear. Here, we show that administration of folic acid significantly improves glucose tolerance, insulin sensitivity, and dyslipidemia in high-fat diet (HFD) fed mice. Moreover, folic acid treatment significantly inhibits lipid deposition in hepatocytes both in vivo and in vitro. Mechanically, folic acid reduces the expression of m6A demethylase AlkB homolog 5 (ALKHB5) via promoter DNA hypermethylation. Decreased ALKBH5 causes increased m6A modification and increased expression of ATG12 in a demethylase activity-dependent manner, thereby promoting autophagy and preventing hepatic steatosis. Inhibition of ATG12 induced by overexpression of ALKBH5 could impair autophagy and the inhibitory effect of folic acid on lipid accumulation in hepatocytes. Together, these findings provide novel insights into understanding the protective role of folic acid in the treatment of NAFLD and suggest that folic acid may be a potential agent for combating NAFLD.

The role of RAB12 in inhibiting osteogenic differentiation and driving metabolic dysregulation in osteoporosis

AIMS

The osteogenic differentiation of mesenchymal stem cells (MSCs) is crucial in osteoporosis, and the metabolic level of the bone microenvironment directly affects metabolic dysregulation in postmenopausal women. RAB12 is a member of the small GTPase Rab family proteins, known to play an important role in autophagy. However, the role of RAB12 in the osteogenic differentiation of osteoporotic hMSCs remains unclear.

MATERIALS AND METHOD

Immunohistochemical staining was used to validate the high expression of RAB12 in aged osteoporotic mouse models and ovariectomized (OVX) mouse models. Co-immunoprecipitation (Co-IP) and LC-MS/MS were employed to explore downstream proteins that may interact with RAB12. Adenovirus containing RAB12 siRNA sequences was injected into the tail vein of OVX osteoporotic mice to analyze the impact of the RAB12/PCBP1/GLUT1 axis on MSC osteogenic differentiation.

KEY FINDINGS

We found that RAB12 expression is upregulated in elderly osteoporotic patients and in osteoporotic mouse models. RAB12 negatively regulates the osteogenic differentiation of hMSCs both in vivo and in vitro. RAB12 interacts with the PCBP1 protein, affecting its autophagic degradation when its expression levels change. RAB12 regulates the transcriptional level of GLUT1 by influencing the autophagic degradation of PCBP1, thereby affecting MSC's regulation of glucose uptake, which in turn impacts MSC osteogenic differentiation and metabolic changes.

SIGNIFICANCE

RAB12 negatively regulates osteogenic differentiation through the PCBP1/GLUT1 axis, affecting glucose metabolism levels in the bone microenvironment. RAB12 may serve as a potential target for the treatment of osteoporosis and postmenopausal metabolic dysregulation.

Beclin-1-dependent autophagy protects perivascular adipose tissue function from hyperaldosteronism effects

Hyperaldosteronism (HA), characterized by excessive production of aldosterone (Aldo), contributes to cardiovascular damage and perivascular adipose tissue (PVAT) dysfunction. Previous studies have shown that Aldo can impair autophagy in various tissues. However, it remains unclear whether this impairment occurs specifically in PVAT and whether it involves disruption of autophagic flux through Beclin-1 (BCN1), a key regulator of autophagosome formation and maturation. We hypothesize that BCN1-dependent autophagy plays a protective role in PVAT by limiting inflammation and preserving its anticontractile function in the context of HA. Male and female C57BL/6J [wild type (WT)] and BCN1 knock-in mice, aged 10-12 wk, underwent 14-day aldosterone infusion (600 µg/kg/day) using an osmotic minipump. Vascular function was assessed in PVAT-intact thoracic aortae, and blood pressure was monitored via radiotelemetry. HA disrupted PVAT autophagic flux, leading to the accumulation of LC3II/I and p62 proteins and reduced BCN1 expression/activity. In WT mice, PVAT exhibited an anticontractile effect, which was abolished by HA. In contrast, BCN1-knock-in mice were protected from this loss of PVAT function. HA also induced oxidative stress and inflammation in PVAT, as evidenced by increased reactive oxygen species generation and elevated mRNA levels of TNF-α, IL-6, IL-1β, and IL-17. These proinflammatory and prooxidative changes were not observed in BCN1-knock-in mice, indicating preserved PVAT homeostasis. Furthermore, pharmacological induction of autophagy via spermidine and activation of BCN1 with TB peptide improved PVAT function in HA-treated WT mice. Finally, BCN1-knock-in mice exhibited partial protection against HA-induced hypertension, highlighting the systemic vascular benefits of enhanced autophagic flux. In summary, our findings demonstrate that the activation of autophagy provides protection against HA-induced PVAT inflammation, dysfunction, and hypertension. Consequently, the activation of BCN1 could serve as a pharmacological strategy to prevent the harmful cardiovascular effects associated with HA.NEW & NOTEWORTHY Elevated aldosterone levels, as seen in primary hyperaldosteronism, obesity, and hypertension, impair autophagic flux in perivascular adipose tissue (PVAT), leading to increased inflammation and loss of anticontractile function. The Beclin-1-dependent autophagic pathway plays a key role in maintaining PVAT homeostasis and vascular tone. Disrupted autophagy contributes to oxidative stress and hypertension. Activating this pathway may offer a novel therapeutic strategy to mitigate aldosterone's harmful vascular effects in hypertension by restoring PVAT function and vascular inflammation.

Bilateral asymmetrical variation of median artery in coexistence with bifid median nerve and variation in the origin and course of its palmar cutaneous branch: a case study with clinical implications

The median artery typically regresses after two months of intrauterine life, although it may persist into adulthood in some individuals. The presence of a persistent median artery (PMA) may be associated with other anatomical variations including a bifid median nerve. In the present cadaveric study, we report a rare variation of bilateral asymmetry of PMA associated with the bifid median nerve, and unilateral variation of the origin and course of the palmar cutaneous branch of the median nerve (PCBMN) which to our knowledge, is the first study to report all these variations in an individual. Classical dissection of the upper limb was performed on a 45-year-old male cadaver. The cadaver was donated to the Department of Anatomy at Kerman University of Medical Sciences. Bilateral PMA was observed in both upper limbs. The PMA originated from the ulnar artery and contributed to the formation of an incomplete superficial palmar arch (SPA) on both sides; however, the branching pattern of these arteries was different between the right and left hands. Also, a bilateral high division of the median nerve was observed proximal to the carpal tunnel. We also encountered a very rare variation of PCBMN, in which it originated from the ulnar side of the median nerve, and passed beneath the flexor retinaculum of the left hand. Awareness of anatomical variations of the median nerve and also the presence of PMA is of utmost importance due to their implication in carpal tunnel syndrome and surgical complications.

Mito-Kaede photoactivation and chase experiment for mitophagy: mitophagy flux response toward various stimulations

Mitophagy, a crucial mitochondrial quality control system for cellular stress adaptation, is a key focus in pathophysiology and drug discovery. Developing a simple and versatile mitophagy flux assay is vital for advancing our understanding of cellular responses. Addressing a gap in systematic methods, we employ the photoactivatable fluorescent protein mito-Kaede in C2C12 myocytes, demonstrating its remarkable versatility in quantifying mitophagy flux responses under various stimuli, including carbonyl cyanide m-chlorophenyl hydrazone (CCCP), TNF-α, lipopolysaccharide (LPS), and hypoxia. This study underscores the validity and distinctive advantages of the mito-Kaede assay through comparative analysis with conventional assays including Western blotting (WB), potentially providing valuable insights for both mitophagy flux analysis and drug development.

Dual Modulation of Autophagy and Apoptosis as Anticancer Mechanism of Action of Khaya grandiofoliola in Colon Carcinoma Cells

Khaya grandiofoliola (Kh) is a medicinal plant with therapeutic properties. Studies have reported on the general bioactivity and anticancer potentials of the plant, but no investigations have yet investigated its anticancer mechanism of action. This study presents the first examination of the anticancer mechanism of action of the methanolic extract of Kh, alongside phytochemical profiling of its anticancer constituents. We conducted in vitro investigations into the mechanism of action of Kh and performed bioactivity-guided fractionation, with subsequent identification of its anticancer phytochemicals using HPLC and GC-MS, respectively. Kh posed a potent antiproliferative effect against colon carcinoma cells and an antioxidant property at low microgram levels. Furthermore, the treatment of Kh in Caco-2 cells led to the accumulation of p62 puncta, indicating inhibition of autophagic flux degradation. Kh impacts microtubule, induced G1 arrest, and late apoptosis induction in Caco-2 cells. Phytochemicals belonging to sesquiterpene alcohols were found most abundant in the Kh bioactive fractions. The identified phytochemicals are potential inducers of apoptosis, autophagy flux inhibition, and G1-phase arrest. Our findings suggest that the anticancer property of Kh is mediated through the dual modulation of autophagy and apoptosis. Further studies are needed to isolate the active compounds responsible for these effects and further elucidate the underlying molecular mechanisms.

Nuclear basket nucleoporin MoNup50 is essential for fungal development, pathogenicity, and autophagy in Magnaporthe oryzae

Autophagy is crucial for appressorium development and host invasion by phytopathogenic fungi, including Magnaporthe oryzae. During appressorium maturation, many organelles, such as nuclei, in the conidia need to be degraded through autophagy to be recycled in appressorium. However, the interplay between autophagy and nuclear membrane systems remains poorly understood. In this study, we functionally characterized MoNup50, a nuclear pore-associated protein. Despite sharing limited sequence identity with human and yeast Nup proteins, MoNup50 contains conserved domains typical of nuclear pore complex proteins. Observation under fluorescence microscopy revealed that MoNup50 localizes at the nuclear membrane in M. oryzae. Deletion of MoNUP50 resulted in reduced hyphal growth, spore production, appressorium formation, and pathogenicity, while increasing sensitivity to osmotic stress and cell wall disruption. Notably, MoNup50 interacts with the key autophagy protein MoAtg7, which regulates MoAtg8-PE synthesis during autophagy. Moreover, MoNUP50 deletion led to elevated autophagy levels and increased phosphorylation of the MAPKs Osm1 and Mps1. These findings suggest that MoNup50 is involved in appressorium morphogenesis and pathogenicity by modulating autophagy and MAPK pathways, highlighting the critical role of nuclear pore proteins in M. oryzae pathogenicity and their potential cross-talk with autophagic and MAPK signaling.

Ginsenoside Rg1 attenuates T2DM-induced renal damage and fibrosis by inhibiting TRPC6-ChREBP-TXNIP signaling

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, ginseng has many benefits, including regulating blood sugar, blood pressure and so on. Ginsenoside Rg1 is the main active component of ginseng and has been found to significantly improve renal pathological injury in type 2 diabetes mellitus (T2DM) mice. However, the effects and mechanisms of Rg1 in attenuating T2DM are not fully understood.

AIM OF THE STUDY

This study aims to investigate the role of Rg1 in the treatment of renal damage and fibrosis induced by T2DM and its molecular mechanism.

MATERIALS AND METHODS

T2DM models were constructed on mice and cells respectively and were administered with corresponding drugs. SA-β-Gal and Oil Red O were used to observe cell senescence and lipid droplet deposition; H&E and PAS were used to observe pathological changes in the kidney; masson and sirius red were used to evaluate the level of renal fibrosis. Immunohistochemistry, immunofluorescence and Western blotting were performed to analyze the relevant indexes which resulted in the detection of ROS levels in vitro and in vivo. Calcium imaging was used to test the level of [Ca2+]i.

RESULTS

Rg1 and Trpc6 knockout could significantly improve kidney dysfunction, attenuate renal injury and fibrosis and also decrease the expression levels of TRPC6, CaN, TXNIP, ChREBP, p-ASK1 and NLRP3 inflammasome. Meanwhile, Rg1 and Trpc6 knockout significantly inhibited mitochondrial damage and apoptosis protein release. Additionally, Rg1 treatment has been shown to markedly reduce lipid deposition and ROS accumulation in T2DM, while Trpc6 knockout exhibited no effect on these parameters.

CONCLUSION

Rg1 treatment can inhibit the TRPC6-ChREBP-TXNIP pathway, thereby improving chronic T2DM-induced renal injury and fibrosis.

Induction of the ISR by AB5 subtilase cytotoxin drives type-I IFN expression in pDCs via STING activation

We demonstrate that exposure to the AB5 subtilase cytotoxin (SubAB) induces the unfolded protein response (UPR) in human peripheral blood mononuclear cells, concomitant with a proinflammatory response across distinct cell subsets. Notably, SubAB selectively induces type-I interferon (IFN) expression in plasmacytoid dendritic cells, acting synergistically with Toll-like receptor 7 stimulation. The induction of type-I IFN in response to SubAB relies on stimulator of interferon genes (STING) activation, coupled with protein synthesis inhibition mediated by protein kinase R-like endoplasmic reticulum kinase (PERK) and phosphorylation of the eukaryotic translation initiation factor 2 subunit-alpha. By impeding mRNA translation through the integrated stress response, SubAB precipitates the downregulation of the negative innate signaling feedback regulator Tax1-binding protein 1. This downregulation is necessary to unleash TANK-binding kinase 1 signaling associated with STING activation. These findings shed light on how UPR-inducing conditions may regulate the immune system during infection or pathogenesis.

Therapeutic Potential of Plant-Derived Small Extracellular Vesicles in Sepsis: A Network Meta-analysis

Sepsis is a life-threatening condition characterized by systemic inflammation and multi-organ dysfunction. Plant-derived small extracellular vesicles (sEVs) have emerged as promising therapeutic agents due to their antioxidant, anti-inflammatory, and immunomodulatory properties. This study conducted a network meta-analysis to identify the most effective plant-derived sEVs for reducing sepsis-induced inflammation and oxidative stress. The analysis included 13 studies evaluating 10 plant-derived sEVs in sepsis-mimicking conditions, with primary outcomes focused on cytokine levels and reactive oxygen species (ROS) production in vitro and in vivo. Secondary outcomes included nuclear factor erythroid 2-related factor 2 (Nrf2) expression and cell viability. The study protocol was registered with PROSPERO (CRD420251011005). Ginger-derived sEVs were identified as the most effective, significantly reducing pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor-α), increasing the anti-inflammatory cytokine (interleukin-10), and suppressing ROS production. They also enhanced Nrf2 expression and improved cell viability, highlighting their role in antioxidant defense and cytoprotection. In conclusion, ginger-derived sEVs are the most effective plant-derived sEVs for mitigating sepsis-induced inflammation and oxidation in both in vitro and in vivo sepsis-mimicking models.

A versatile electrochemical, colorimetric, and visible light excitable turn-on fluorescent probe for stress-induced H2S detection

Hydrogen sulfide (H2S) holds a distinct role in cell biology. Its level is intricately linked to the homeostasis of the biological environment, underscoring the significance of developing techniques capable of detecting H2S in biological systems. A single probe that offers versatility across different detection techniques opens opportunities for advancements in sensing H2S in various fields. A nitronaphthalimide derivative, NMO prepared using a simple synthetic protocol, has been studied as an electrochemical, colorimetric, and turn-on fluorescence probe for H2S. NMO displayed a detection limit of 9.95 mM and 4.36 mM in the UV-visible and colorimetric studies, respectively, whereas the fluorometric and square wave techniques confirmed lower detection limits of 98.4 μM and 1.24 mM, correspondingly. Further, the real-time imaging of HEK293T cells using NMO during stress-induced autophagy is demonstrated.

Rest, Repair, Repeat: The Complex Relationship of Autophagy and Sleep

Autophagy and sleep are two evolutionary conserved mechanisms across the animal kingdom. Autophagy is a pathway for the degradation of cytoplasmic material in the lysosome, playing important roles in the homeostasis and health of the organism. On the other hand, sleep is a homeostatically regulated state with numerous presumed essential roles, including the restoration of tissue and physiological functions, such as brain waste clearance via the activation of the glymphatic systems. Given that sleep and autophagy are crucial processes tightly linked to homeostasis and maintenance of good health, understanding how they interact is of great interest, especially as sleep quality decreases in our modern 24-hour societies. Autophagy represents a promising target for therapeutic interventions in this context. Here, we review the contrasted and complementary roles of autophagy and sleep in maintaining homeostasis. Specifically, we focus on recent evidence suggesting that sleep impairment may increase autophagy, while autophagosome levels may modulate the amount of sleep. We discuss outstanding questions at the intersection of these two fields, highlighting methodological shortcomings in the current literature. Overcoming these limitations will be instrumental to design new experiments with the aim of answering one of the greatest mysteries of our time - why do we sleep?

Reticulon-dependent ER-phagy mediates adaptation to heat stress in C. elegans

The selective degradation of endoplasmic reticulum (ER) by autophagy, named ER-phagy, promotes the recovery of ER homeostasis after stress. Depending on the ER stress, different types of ER-phagy involve various selective autophagy receptors. In this study, we report a macroER-phagy induced by the fragmentation of tubular ER in response to acute heat stress. We identified a novel ER-phagy receptor encoded by the reticulon long isoform RET-1d. RET-1d is mainly expressed in the nervous system and the epidermis and colocalizes with the ubiquitin-like autophagy protein LGG-1/GABARAP during heat-stress-induced autophagy. Two LC3-interacting region (LIR) motifs in the long intrinsically disordered region of RET-1d mediate its interaction with the LGG-1 protein. The specific depletion of the RET-1d isoform or the mutations of the LIRs resulted in a defective ER-phagy and a decrease in the capacity of animals to adapt to heat stress. Our data revealed a RET-1d- and LGG-1-dependent ER-phagy mechanism that takes place in neurons and epidermis and participates in the adaptation of C. elegans to heat stress.

Vacuolar Proteases of Candida auris from Clades III and IV and Their Relationship with Autophagy

Candida auris is a multidrug-resistant pathogen with a high mortality rate and widespread distribution. Additionally, it can persist on inert surfaces for extended periods, facilitating its transmissibility in hospital settings. Autophagy is a crucial cellular mechanism that enables fungal survival under adverse conditions. A fundamental part of this process is mediated by vacuolar proteases, which play an essential role in the degradation and recycling of cellular components. The present work explores the relationship between C. auris vacuolar peptidases and autophagy, aiming to establish a precedent for understanding the survival mechanisms of this emerging fungus. Thus, eight genes encoding putative vacuolar peptidases in the C. auris genomes were identified: PEP4, PRB1, PRC1, ATG42, CPS, LAP4, APE3, and DAP2. Analysis of the protein domains and their phylogenetic relationships suggests that these enzymes are orthologs of Saccharomyces cerevisiae vacuolar peptidases. Notably, both vacuolar protease gene expression and the proteolytic activity of cell-free extracts increased under nutritional stress and rapamycin. An increase in the expression of the ATG8 gene and the presence of autophagic bodies were also observed. These results suggest that proteases could play a role in yeast autophagy and survival during starvation conditions.

Effect of NiCl2 Intake Through Respiratory Tract on Antioxidant Capacity, Lung, and Trace Element Content in Mice

This study examined the acute respiratory toxicity of NiCl2 in mice, focusing on oxidative stress, tissue damage, and trace element dysregulation. Forty male KM mice were allocated to a saline control group and three NiCl2 exposure groups (20, 60, 115 mg/kg; n = 10/group). Serum analysis assessed oxidative stress (MDA, GSH, SOD), liver (AST, ALT), kidney (Cr, BUN) function, and TP. Lung and tracheal tissues were examined for histopathological/ultrastructural pathological changes and apoptosis. Tissue levels of Ni, Zn, Cu, Fe, Ca, Mg, and Mn were measured using spectrophotometry. Results revealed dose-responsive elevations in serum AST, ALT, BUN, Cr, and MDA, accompanied by diminished GSH, TP, and T-SOD (P < 0.05). Nickel exposure caused tracheal pseudostratified columnar epithelium detachment, alveolar structural wall thickening and widened septa, capillary congestion, mitochondrial swelling in alveolar type-II cells, and increased pulmonary apoptosis (P < 0.05). Ni accumulated predominantly in the liver, lung, and kidney, with concurrent Zn upregulation and Cu/Fe depletion (P < 0.05), while Ca, Mg, and Mn levels remained stable. These findings demonstrate that acute NiCl2 inhalation induces oxidative stress, impairs liver/kidney function, and provokes pulmonary apoptosis and mitochondrial damage. Ni disrupted Cu/Zn/Fe homeostasis but exhibited negligible effects on Ca, Mg, or Mn metabolism.

Roles of class III phosphatidylinositol 3-kinase, Vps34, in phagocytosis, autophagy, and endocytosis in retinal pigmented epithelium

Phosphatidylinositol-3-phosphate (PI(3)P) is important for multiple functions of retinal pigmented epithelial (RPE) cells, but its functions in RPE have not been studied. In RPE from mouse eyes and in cultured human RPE cells, PI(3)P-enriched membranes include endosomes, the trans-Golgi network, phagosomes, and autophagophores. Mouse RPE cells lacking activity of the PI-3 kinase, Vps34, lack detectable PI(3)P and die prematurely. Phagosomes containing rod discs accumulate, as do membrane aggregates positive for autophagosome markers. These autophagy-related membranes recruit LC3/Atg8 without Vps34, but phagosomes do not. Vps34 loss leads to accumulation of lysosomes which do not fuse with phagosomes or membranes with autophagy markers. Thus, Vps34-derived PI(3)P is not needed for initiation of phagocytosis or endocytosis, nor for formation of membranes containing autophagy markers. In contrast, Vps34 and PI(3)P are essential for intermediate and later stages, including membrane fusion with lysosomes.

Recovery of Lysosomal Acidification and Autophagy Flux by Attapulgite Nanorods: Therapeutic Potential for Lysosomal Disorders

Dysfunction of the lysosome and autophagy-lysosome pathway is closely associated with various diseases, such as neurodegenerative diseases, non-alcoholic fatty liver disease (NAFLD), etc. Additionally, chloroquine is a clinically widely used drug for treating malaria and autoimmune diseases, but long-term or high-dose administration may lead to significant toxic side effects. Attapulgite (ATT), a natural nanomaterial with excellent adsorption capacity and biocompatibility, herein demonstrated a novel biological function in regulating the lysosomal and autophagy-lysosome pathway. ATT could be effectively internalized into lysosome-related acidic compartments. Further study revealed that ATT could restore lysosomal pH, activate cathepsin D, alleviate autophagy blockage in chloroquine-treated cells, and reduce chloroquine-elicited cell death. In a cell model related to Huntington's disease, treatment with ATT reinforced the degradation of the mutant huntingtin proteins by increasing cathepsin D maturation and autophagy flux. ATT could also promote lipid droplet clearance in hepatocytes with palmitic acid-induced steatosis, reduce hepatic lipid accumulation, and improve fasting blood glucose in high-fat-diet-induced NAFLD mice. These findings establish ATT as a lysosomal modulator, providing a foundation for its therapeutic potential in mitigating the adverse effects associated with long-term chloroquine use, especially improving neurodegenerative and metabolic disorders.

LncRNA-induced lysosomal localization of NHE1 promotes increased lysosomal pH in macrophages leading to atherosclerosis

ANRIL, also referred to as CDKN2B-AS1, is a lncRNA gene implicated in the pathogenesis of multiple human diseases including atherosclerotic coronary artery disease, however, definitive in vivo evidence is lacking and the underlying molecular mechanism is largely unknown. In this study, we show that ANRIL overexpression causes atherosclerosis in vivo as transgenic mouse overexpression of full-length ANRIL (NR_003529) increases inflammation and aggravates atherosclerosis under ApoE-/- background (ApoE-/-ANRIL mice). Mechanistically, ANRIL reduces the expression of miR-181b-5p, which leads to increased TMEM106B expression. TMEM106B is significantly up-regulated in atherosclerotic lesions of both human CAD patients and ApoE-/-ANRIL mice. TMEM106B interacts and co-localizes with Na+-H+ exchanger NHE1, which results in mis-localization of NHE1 from cell membranes to lysosomal membranes, leading to increased lysosomal pH in macrophages. Large truncation and point mutation analyses define the critical amino acids for TMEM106B-NHE1 interaction and lysosomal pH regulation as F115 and F117 on TMEM106B and I537, C538, and G539 on NHE1. Topological analysis suggests that both N-terminus and C-terminus of NHE1 are located inside lysosomal lumen, and NHE1 is an important new proton efflux channel involved in raising lysosomal pH. A short TMEM106B peptide (YGRKKRRQRRR-L111A112V113F114F115L116F117) disrupting the TMEM106B-NHE1 interaction normalized lysosomal pH in macrophages with ANRIL overexpression. Our data demonstrate that ANRIL promotes atherosclerosis in vivo and identify the ANRIL/miR-181b-5p/TMEM106B-NHE1/lysosomal pH axis as the underlying molecular pathogenic mechanism for the chromosome 9p21.3 genetic locus for coronary artery disease.

Time-restricted feeding attenuated hypertension-induced cardiac remodeling by modulating autophagy levels in spontaneously hypertensive rats

To investigate whether time-restricted feeding (TRF) can alleviate cardiac remodeling in spontaneously hypertensive rats (SHRs) by regulating autophagy levels. A 16-week TRF intervention was conducted on Wistar Kyoto (WKY) rats and SHRs, with dietary intake confined to the interval from 9:00 am to 5:00 pm each day. The study examined the impact of TRF on blood pressure (BP), cardiac morphology and function, and the expression levels of key proteins involved in autophagy and its associated signaling cascades. Transmission Electron Microscopy (TEM) was utilized to further evaluate autophagic changes in left ventricular (LV) tissues. TRF significantly mitigated systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) in SHRs. Additionally, TRF improved ejection fraction (EF) and diminished interventricular septal thickness at end-diastole (IVS-d). The study further revealed that TRF enhanced the expression of microtubule-associated protein-I light chain 3 (LC3-I), while reducing that of microtubule-associated protein-II light chain 3 (LC3-II). Moreover, TRF suppressed the expression levels of Beclin-1, phosphorylated phosphoinositide 3-kinase (p-PI3K), phosphorylated protein kinase B (p-AKT), and phosphorylated mechanistic target of rapamycin (p-mTOR) in the LV tissues. TEM analysis confirmed that TRF could inhibit autophagy levels in the LV tissues. TRF can attenuate cardiac remodeling in SHRs by regulating autophagy levels.

Regulation of autophagy: Insights into O-GlcNAc modification mechanisms

Autophagy is a "self-eating" biological process that degrades cytoplasmic contents to ensure cellular homeostasis. Its response to stimuli occurs in two stages: Within a few to several hours of exposure to a stress condition, autophagic flow rapidly increases, which is mediated by post-translational modification (PTM). Subsequently, the transcriptional program is activated and mediates the persistent autophagic response. O-linked β-N-acetylglucosamine (O-GlcNAc) modification is an inducible and dynamically cycling PTM; mounting evidence suggests that O-GlcNAc modification participates in the total autophagic process, including autophagy initiation, autophagosome formation, autophagosome-lysosome fusion, and transcriptional process. In this review, we summarize the current knowledge on the emerging role of O-GlcNAc modification in regulating autophagy-associated proteins and explain the different regulatory effects on autophagy exerted by O-GlcNAc modification.

TRIM23 mediates cGAS-induced autophagy in anti-HSV defense

The cGAS-STING pathway, well-known to elicit interferon (IFN) responses, is also a key inducer of autophagy upon virus infection or other stimuli. Whereas the mediators for cGAS-induced IFN responses are well characterized, much less is known about how cGAS elicits autophagy. Here, we report that TRIM23, a unique TRIM protein harboring both ubiquitin E3 ligase and GTPase activity, is crucial for cGAS-STING-dependent antiviral autophagy. Genetic ablation of TRIM23 impairs autophagic control of HSV-1 infection. HSV-1 infection or cGAS-STING stimulation induces TBK1-mediated TRIM23 phosphorylation at S39, which triggers TRIM23 autoubiquitination and GTPase activity and ultimately elicits autophagy. Fibroblasts from a patient with herpes simplex encephalitis heterozygous for a dominant-negative, kinase-inactivating TBK1 mutation fail to activate autophagy by TRIM23 and cGAS-STING. Our results thus identify the cGAS-STING-TBK1-TRIM23 axis as a key autophagy defense pathway and may stimulate new therapeutic interventions for viral or inflammatory diseases.

SARS-CoV-2 ORF3a drives dynamic dense body formation for optimal viral infectivity

SARS-CoV-2 hijacks multiple organelles for virion assembly, of which the mechanisms have not been fully understood. Here, we identified a SARS-CoV-2-driven membrane structure named the 3a dense body (3DB). 3DBs are unusual electron-dense and dynamic structures driven by the accessory protein ORF3a via remodeling a specific subset of the trans-Golgi network (TGN) and early endosomal membrane. 3DB formation is conserved in related bat and pangolin coronaviruses but was lost during the evolution to SARS-CoV. During SARS-CoV-2 infection, 3DB recruits the viral structural proteins spike (S) and membrane (M) and undergoes dynamic fusion/fission to maintain the optimal unprocessed-to-processed ratio of S on assembled virions. Disruption of 3DB formation resulted in virions assembled with an abnormal S processing rate, leading to a dramatic reduction in viral entry efficiency. Our study uncovers the crucial role of 3DB in maintaining maximal SARS-CoV-2 infectivity and highlights its potential as a target for COVID-19 prophylactics and therapeutics.

NLRP3 inflammasome inhibits mitophagy during the progression of temporal lobe epilepsy

Epilepsy is a neurological disorder involving mitochondrial dysfunction and neuroinflammation. This study examines the relationship between NLRP3 inflammasome activation and mitophagy in the temporal lobe epilepsy, which has not been reported before. A pilocarpine-induced epileptic rat model was used to assess seizure activity and neuronal loss. Pyroptosis markers (NLRP3, cleaved Gasdermin D, IL-1β/IL-18), and autophagy/mitophagy activity (LC3B-II/I, BNIP3, TOMM20/LC3B colocalization) were analyzed via immunofluorescence, Western blot, and transmission electron microscopy. NLRP3 inhibitors and anti-IL-1β antibodies were administered to evaluate therapeutic effects. Epileptic rats exhibited progressive neuronal loss and seizure aggravation, correlating with NLRP3 inflammasome activation and pyroptosis. While general autophagy was upregulated, mitophagy was selectively impaired in the hippocampus. NLRP3 activation promoted IL-1β release, which suppressed mitophagy via PPTC7 upregulation. NLRP3 activation inhibitor (MCC950) and anti-IL-1β treatment restored mitophagy and reduced seizures. NLRP3 inflammasome-driven pyroptosis exacerbates epilepsy by impairing mitophagy activity via IL-1β/PPTC7. Targeted NLRP3 inhibition mitigates this cascade, offering a promising strategy for refractory epilepsy.

SLC35A2-mediated bisected GlcNAc-modified extracellular vesicles enhance immune regulation in breast cancer lung metastasis

This study investigates the role of SLC35A2-mediated bisected GlcNAc-modified small extracellular vesicles (sEVs) in breast cancer (BC) lung metastasis. By modulating B3GALT1 expression, these sEVs regulate the pre-metastatic immune microenvironment, enhancing CD8+ T cell infiltration and reducing immune evasion. The use of β-peptide-loaded sEVs further amplifies anti-metastatic effects, as demonstrated in vivo mouse models and molecular analyses. These findings underscore the therapeutic potential of glycosylation-modified sEVs in enhancing immune responses and controlling BC metastasis.

Dual Role of Natural Killer Cells in Early Pregnancy: Immunopathological Implications and Therapeutic Potential in Recurrent Spontaneous Abortion and Recurrent Implantation Failure

Natural killer (NK) cells are critical regulators of immune processes during early pregnancy, playing a key role in maintaining maternal-foetal immune tolerance and supporting successful implantation. In particular, uterine NK cells, a specialised subset of NK cells, facilitate trophoblast invasion, spiral artery remodelling and placental establishment. Dysregulation of NK cell activity, however, has been implicated in pregnancy complications, notably recurrent spontaneous abortion (RSA) and recurrent implantation failure (RIF). Aberrant NK cell functions, such as heightened cytotoxicity or defective immune signalling, can disrupt the balance between immune tolerance and response, leading to impaired placental development, reduced trophoblast activity and compromised uteroplacental blood flow. This review examines the role of NK cells in early pregnancy, emphasising their contributions to immune modulation and placentation. It also investigates the mechanisms by which NK cell dysfunction contributes to RSA and RIF, and explores therapeutic strategies aimed at restoring NK cell balance to improve pregnancy outcomes. A deeper understanding of NK cell interactions during early pregnancy may provide critical insights into the pathogenesis of pregnancy failure and facilitate targeted immunotherapeutic approaches.

Autophagic activity in the midgut cells of three arachnids responds selectively to different modes of overwintering in caves

Autophagy is a highly conserved metabolic process that regulates cellular homeostasis and energy supply by degrading dysfunctional and excess cell constituents and reserve materials into products that are reused in metabolic and biosynthetic pathways. Macroautophagy is the best studied form of autophagy in invertebrates. Starvation is a common stress factor triggering autophagy in overwintering animals. In arachnids, the midgut diverticula cells perform many vital metabolic functions and are therefore critically involved in the response to starvation. Here we studied macroautophagy in three species which apply different modes for overwintering in caves: the harvestmen Gyas annulatus in diapause, Amilenus aurantiacus with ongoing ontogenesis under fasting conditions, and the spider Meta menardi, which feeds opportunistically even in winter. The main goal was to find eventual qualitative and quantitative differences in autophagic processes by inspecting TEM micrographs. In all three species, the rates of midgut epithelial cells with autophagic structures gradually increased during overwintering, but were significantly lower in G. annulatus in the middle and at the end of overwintering than in the other two species, owing to metabolic activity having been more suppressed. Decomposition of mitochondria and glycogen took place in autophagic structures in all three species. Moreover, spherite disintegration in A. aurantiacus and a special form of lipid disintegration through "lipid bubbly structures" in M. menardi indicate the crucial involvment of selective autophagy, while no specific autophagy was observed in G. annulatus. We conclude that autophagic activities support overwintering in different ways in the species studied.

Intermittent time-restricted eating may increase autophagic flux in humans: an exploratory analysis

Autophagy slows age-related pathologies and is stimulated by nutrient restriction in animal studies. However, this has never been shown in humans. We measured autophagy using a physiologically relevant measure of autophagic flux (flux of MAP1LC3B isoform II/LC3B-II in peripheral blood mononuclear cells in the context of whole blood) in 121 humans with obesity who were randomised to standard care (SC, control condition), calorie restriction (CR) or intermittent fasting plus time-restricted eating (iTRE) for 6 months. While the differences in change from baseline between groups was not significant at 2 months, we observed a significant difference in change from baseline between iTRE compared to SC at 6 months (P = 0.04, post hoc analysis). This effect may be driven partly by a tendency for autophagy to decrease in the SC group. The difference in change from baseline between CR and SC was not significant. Uncorrected analysis of correlations showed a negative relationship between change in autophagy and change in blood triglycerides. Data on the specificity and performance of the methods used to measure human autophagy are also presented. This shows autophagy may be increased by intermittent nutrient restriction in humans. If so, this is a demonstration that nutrient restriction can be used to improve a primary hallmark of biological ageing and provides a mechanism for how fasting could delay the onset of age-related disease. KEY POINTS: Autophagy slows biological ageing, and dysfunction of autophagy has been implicated in age-related disease - an effective way of increasing autophagy in cells and animal models is nutrient restriction. However, the impact of different types of nutrient restriction on physiological autophagic flux in humans has not been extensively researched. Here we measure the effect of intermittent time-restricted eating (iTRE) and calorie restriction on physiological autophagic flux in peripheral blood mononuclear cells. After 6 months, there was a significant difference in change from baseline between the iTRE and the standard care control group, with flux being higher in the iTRE group at this timepoint. However, there was no significant increase from baseline within the iTRE group, showing that although autophagy may be modified by nutrient restriction in humans, further studies are required.

Autophagy induction by piplartine ameliorates axonal degeneration caused by mutant HSPB1 and HSPB8 in Charcot-Marie-Tooth type 2 neuropathies

HSPB1 [heat shock protein family B (small) member 1] and HSPB8 are essential molecular chaperones for neuronal proteostasis, as they prevent protein aggregation. Mutant HSPB1 and HSPB8 primarily harm peripheral neurons, resulting in axonal Charcot-Marie-Tooth neuropathies (CMT2). Macroautophagy/autophagy is a shared mechanism by which HSPB1 and HSPB8 mutations cause neuronal dysfunction. Autophagosome formation is reduced in mutant HSPB1-induced pluripotent stem-cell-derived motor neurons from CMT type 2F patients. Likewise, the HSPB8K141N knockin mouse model, mimicking CMT type 2 L, exhibits axonal degeneration and muscle atrophy, with SQSTM1/p62-positive deposits. We show here that mouse embryonic fibroblasts isolated from a HSPB8K141N/green fluorescent protein (GFP)-LC3 model have diminished autophagosome production under conditions of MTOR inhibition. To correct the autophagic deficits in the HSPB1 and HSPB8 models, we screened by high-throughput autophagosome quantification the repurposing Spectrum Collection library for molecules that could boost the autophagic activity above the canonical MTOR inhibition. Hit compounds were validated on motor neurons obtained by differentiation of HSPB1P182L and HSPB8K141N patient-derived induced pluripotent stem cells, focusing on autophagy induction as well as neurite network density, axonal degeneration, and mitochondrial morphology. We identified molecules that specifically stimulate autophagosome formation in the HSPB8K141N cells, without affecting autophagy flux. Two top lead compounds induced autophagy and reduced axonal degeneration, thus promoting neuronal network maturation in the CMT2 patient-derived motor neurons. Based on these findings, the phenotypical screen revealed that piplartine rescued autophagy deficiencies in both the HSPB1 and HSPB8 models, demonstrating autophagy induction as an effective therapeutic strategy for CMT neuropathies and other chaperonopathies.

Mitophagy is induced in human engineered heart tissue after simulated ischemia and reperfusion

The paradoxical exacerbation of cellular injury and death during reperfusion remains a problem in the treatment of myocardial infarction. Mitochondrial dysfunction plays a key role in the pathogenesis of myocardial ischemia and reperfusion injury. Dysfunctional mitochondria can be removed by mitophagy, culminating in their degradation within acidic lysosomes. Mitophagy is pivotal in maintaining cardiac homeostasis and emerges as a potential therapeutic target. Here, we employed beating human engineered heart tissue (EHT) to assess mitochondrial dysfunction and mitophagy during ischemia and reperfusion simulation. Our data indicate adverse ultrastructural changes in mitochondrial morphology and impairment of mitochondrial respiration. Furthermore, our pH-sensitive mitophagy reporter EHTs, generated by a CRISPR/Cas9 endogenous knock-in strategy, revealed induced mitophagy flux in EHTs after ischemia and reperfusion simulation. The induced flux required the activity of the protein kinase ULK1, a member of the core autophagy machinery. Our results demonstrate the applicability of the reporter EHTs for mitophagy assessment in a clinically relevant setting. Deciphering mitophagy in the human heart will facilitate development of novel therapeutic strategies.

Percutaneous ultrasound guided retrograde lacertus fibrosus release

The purpose of this technical note is to present a microinvasive percutaneous ultrasound-guided release of the lacertus fibrosus of the biceps brachii for lacertus syndrome, i.e., median nerve entrapment at the elbow. Using the Walant technique (wide awake local anesthesia and no tourniquet), the entry point is made with a 19G needle to introduce the hook distally from the distal border of the lacertus fibrosus. The hook is then slid along the pronator teres fascia to the proximal border of the lacertus fibrosus. The cut is ultrasound-guided from proximal to distal. The cut is effective when the back of the force is observed in the 3 targeted muscles (flexor carpi radialis, flexor pollicis longus and flexor digitorum profundus). This minimally invasive surgical procedure is efficient in terms of lacertus fibrosus sectioning. Real-time ultrasound monitoring may improve safety. The technique could be considered as a new ultrasound-guided alternative to open surgery. When performed superficially to the pronator teres muscle under WALANT anesthesia and percutaneously, ultrasound-guided lacertus fibrosus release may be an effective treatment for lacertus syndrome in the interventional ultrasound unit.

GPNMB disrupts SNARE complex assembly to maintain bacterial proliferation within macrophages

Xenophagy plays a crucial role in restraining the growth of intracellular bacteria in macrophages. However, the machinery governing autophagosome‒lysosome fusion during bacterial infection remains incompletely understood. Here, we utilize leprosy, an ideal model for exploring the interactions between host defense mechanisms and bacterial infection. We highlight the glycoprotein nonmetastatic melanoma protein B (GPNMB), which is highly expressed in macrophages from lepromatous leprosy (L-Lep) patients and interferes with xenophagy during bacterial infection. Upon infection, GPNMB interacts with autophagosomal-localized STX17, leading to a reduced N-glycosylation level at N296 of GPNMB. This modification promotes the degradation of SNAP29, thus preventing the assembly of the STX17-SNAP29-VAMP8 SNARE complex. Consequently, the fusion of autophagosomes with lysosomes is disrupted, resulting in inhibited cellular autophagic flux. In addition to Mycobacterium leprae, GPNMB deficiency impairs the proliferation of various intracellular bacteria in human macrophages, suggesting a universal role of GPNMB in intracellular bacterial infection. Furthermore, compared with their counterparts, Gpnmbfl/fl Lyz2-Cre mice presented decreased Mycobacterium marinum amplification. Overall, our study reveals a previously unrecognized role of GPNMB in host antibacterial defense and provides insights into its regulatory mechanism in SNARE complex assembly.