Investigation of Impact of Oxidative Stress on Human Periodontal Ligament Cells Exposed to Static Compression

Oxidative stress (OS) is a common feature of many inflammatory diseases, oral pathologies, and aging processes. The impact of OS on periodontal ligament cells (PDLCs) in relation to oral pathologies, including periodontal diseases, has been investigated in different studies. However, its impact on orthodontic tooth movement (OTM) remains poorly understood. This study used an in vitro model with human PDLCs previously exposed to H2O2 to investigate the effects of OS under a static compressive force which simulated the conditions of OTM. Human PDLCs were treated with varying concentrations of H2O2 to identify sub-lethal doses that affected viability minimally. To mimic compromised conditions resembling OTM under OS, the cells were pretreated with the selected H2O2 concentrations for 24 h. Using an in vitro loading model, a static compressive force (2 g/cm2) was applied for an additional 24 h. The cell viability, proliferation, and cytotoxicity were evaluated using live/dead and resazurin assays. Apoptosis induction was assessed based on caspase-3/7 activity. The gene expression related to bone remodeling (RUNX2, TNFRSF11B/OPG, BGLAP), inflammation (IL6, CXCL8/IL8, PTGS2/COX2), apoptosis (CASP3, CASP8), and autophagy (MAP1LC3A/LC3, BECN1) was analyzed using RT-qPCR. This study suggests an altering effect of previous OS exposure on static-compression-related mechanosensing. Further research is needed to fully elucidate these mechanisms.

Oleanolic Acid Modulates DNA Damage Response to Camptothecin Increasing Cancer Cell Death

Targeting DNA damage response (DDR) pathways represents one of the principal approaches in cancer therapy. However, defects in DDR mechanisms, exhibited by various tumors, can also promote tumor progression and resistance to therapy, negatively impacting patient survival. Therefore, identifying new molecules from natural extracts could provide a powerful source of novel compounds for cancer treatment strategies. In this context, we investigated the role of oleanolic acid (OA), identified in fermented Aglianico red grape pomace, in modulating the DDR in response to camptothecin (CPT), an inhibitor of topoisomerase I. Specifically, we found that OA can influence the choice of DNA repair pathway upon CPT treatment, shifting the repair process from homologous recombination gene conversion to single-strand annealing. Moreover, our data demonstrate that combining sub-lethal concentrations of OA with CPT enhances the efficacy of topoisomerase I inhibition compared to CPT alone. Overall, these findings highlight a new role for OA in the DDR, leading to a more mutagenic DNA repair pathway and increased sensitivity in the HeLa cancer cell line.

Pathology and Treatments of Alzheimer's Disease Based on Considering Changes in Brain Energy Metabolism Due to Type 2 Diabetes

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with cognitive dysfunction, memory decline, and behavioral disturbance, and it is pathologically characterized by the accumulation of amyloid plaques and neurofibrillary tangles in the brain. Although various hypotheses have been proposed to explain the pathogenesis of AD, including the amyloid beta hypothesis, oxidative stress hypothesis, and abnormal phosphorylation of tau proteins, the exact pathogenic mechanisms underlying AD remain largely undefined. Furthermore, effective curative treatments are very limited. Epidemiologic studies provide convincing evidence for a significant association between type 2 diabetes and AD. Here, we showed energy metabolism using glucose, lactate, ketone bodies, and lipids as energy substrates in a normal brain, and changes in such energy metabolism due to type 2 diabetes. We also showed the influences of such altered energy metabolism due to type 2 diabetes on the pathology of AD. Furthermore, we comprehensively searched for risk factors related with type 2 diabetes for AD and showed possible therapeutic interventions based on considering risk factors and altered brain energy metabolism due to type 2 diabetes for the development of AD.

Bee Pollen as a Source of Biopharmaceuticals for Neurodegeneration and Cancer Research: A Scoping Review and Translational Prospects

Bee Pollen (BP) has many advantageous properties relying on its multitargeting potential, a new tendency in managing many challenging illnesses. In cancer and neurodegeneration, the multiple effects of BP could be of unequaled importance and need further investigation. Although still limited, available data interestingly spotlights some floral sources with promising activities in line with this investigation. Adopting scoping review methodology, we have identified many crucial bioactivities that are widely recognized to individual BP compounds but remain completely untapped in this valuable bee cocktail. A wide range of these compounds have been recently found to be endowed with great potential in modulating pivotal processes in neurodegeneration and cancer pathophysiology. In addition, some ubiquitous BP compounds have only been recently isolated, while the number of studied BPs remains extremely limited compared to the endless pool of plant species worldwide. We have also elucidated that clinical profits from these promising perspectives are still impeded by challenging hurdles such as limited bioavailability of the studied phytocompounds, diversity and lack of phytochemical standardization of BP, and the difficulty of selective targeting in some pathophysiological mechanisms. We finally present interesting insights to guide future research and pave the way for urgently needed and simplified clinical investigations.

Investigating the Impact of Glycogen-Depleting Exercise Combined with Prolonged Fasting on Autophagy and Cellular Health in Humans: A Randomised Controlled Crossover Trial

IMPORTANCE

Although prolonged fasting has become increasingly popular, the favourable biological adaptations and possible adverse effects in humans have yet to be fully elucidated.

OBJECTIVE

To investigate the effects of a three-day water-only fasting, with or without exercise-induced glycogen depletion, on autophagy activation and the molecular pathways involved in cellular damage accumulation and repair in healthy humans.

DESIGN

A randomised, single-centre, two-period, two-sequence crossover trial. The primary outcome is autophagic activity, assessed as flux in peripheral blood mononuclear cells (PBMCs) measured in the context of whole blood. Secondary outcomes include changes in body composition, heart rate variability, endothelial function, and genomic, epigenomic, metabolomic, proteomic, and metagenomic adaptations to fasting in plasma, platelets, urine, stools, and PBMCs. Detailed profiling of circulating immune cell populations and their functional states will be assessed by flow cytometry.

SETTING

All clinical investigations will be undertaken at the Charles Perkins Centre Royal Prince Alfred Hospital clinic, University of Sydney, Australia.

PARTICIPANTS

Twenty-four individuals aged 18 to 70 years, with a BMI of 20-40 kg/m2, free of major health conditions other than obesity.

DISCUSSION

While autophagic flux induction through fasting has garnered interest, there is a notable lack of human studies on this topic. This trial aims to provide the most detailed and integrated analysis of how three days of prolonged water-only fasting, combined with glycogen-depleting exercise, affects autophagy activation and other crucial metabolic and molecular pathways linked to cellular, metabolic, and immune health. Insights from this study may pave the way for safe and effective strategies to induce autophagy, offering potential preventive interventions for a range of chronic conditions.

Hapalindole Q suppresses autophagosome-lysosome fusion by promoting YAP1 degradation via chaperon-mediated autophagy

Autophagy is a conserved catabolic process crucial for maintaining cellular homeostasis and has emerged as a promising therapeutic target for many diseases. Mechanistically novel small-molecule autophagy regulators are highly desirable from a pharmacological point of view. Here, we report the macroautophagy-inhibitory effect of hapalindole Q, a member of the structurally intriguing but biologically understudied hapalindole family of indole terpenoids. This compound promotes the noncanonical degradation of Yes-associated protein 1 (YAP1), the downstream effector of the Hippo signaling pathway, via chaperone-mediated autophagy, disrupting proper distribution of Rab7 and suppressing autophagosome-lysosome fusion in macroautophagy. Its binding to YAP1 is further confirmed by using biophysical techniques. A preliminary structure-activity relationship study reveals that the hapalindole Q scaffold, rather than the isothiocyanate group, is essential for YAP1 binding and degradation. This work not only identifies a macroautophagy inhibitor with a distinct mechanism of action but also provided a molecular scaffold for direct targeting of YAP1, which may benefit the development of therapeutics for both autophagy-related and Hippo-YAP-related diseases.

Gene-Silencing Therapeutic Approaches Targeting PI3K/Akt/mTOR Signaling in Degenerative Intervertebral Disk Cells: An In Vitro Comparative Study Between RNA Interference and CRISPR-Cas9

The mammalian target of rapamycin (mTOR), a serine/threonine kinase, promotes cell growth and inhibits autophagy. The following two complexes contain mTOR: mTORC1 with the regulatory associated protein of mTOR (RAPTOR) and mTORC2 with the rapamycin-insensitive companion of mTOR (RICTOR). The phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR signaling pathway is important in the intervertebral disk, which is the largest avascular, hypoxic, low-nutrient organ in the body. To examine gene-silencing therapeutic approaches targeting PI3K/Akt/mTOR signaling in degenerative disk cells, an in vitro comparative study was designed between small interfering RNA (siRNA)-mediated RNA interference (RNAi) and clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein 9 (Cas9) gene editing. Surgically obtained human disk nucleus pulposus cells were transfected with a siRNA or CRISPR-Cas9 plasmid targeting mTOR, RAPTOR, or RICTOR. Both of the approaches specifically suppressed target protein expression; however, the 24-h transfection efficiency differed by 53.8-60.3% for RNAi and 88.1-89.3% for CRISPR-Cas9 (p < 0.0001). Targeting mTOR, RAPTOR, and RICTOR all induced autophagy and inhibited apoptosis, senescence, pyroptosis, and matrix catabolism, with the most prominent effects observed with RAPTOR CRISPR-Cas9. In the time-course analysis, the 168-h suppression ratio of RAPTOR protein expression was 83.2% by CRISPR-Cas9 but only 8.8% by RNAi. While RNAi facilitates transient gene knockdown, CRISPR-Cas9 provides extensive gene knockout. Our findings suggest that RAPTOR/mTORC1 is a potential therapeutic target for degenerative disk disease.

Autophagy and nutrigenomics: a winning team against chronic disease and tumors

Autophagy, a vital cell process, has garnered attention for its role in various diseases and potential therapeutic interventions. Dysregulation of autophagy contributes to conditions such as metabolic diseases, neurodegenerative disorders, and cancer. In diseases such as diabetes, autophagy plays a crucial role in islet β-cell maintenance and glucose homeostasis, offering potential targets for therapeutic intervention. Nutrigenomics, which explores how dietary components interact with the genome, has emerged as a promising avenue for disease management. It sheds light on how diet influences gene expression and cellular processes, offering personalized approaches to disease prevention and management. Studies have showed the impact of specific dietary components, such as polyphenols and omega-3 fatty acids, on autophagy processes, suggesting their potential therapeutic benefits in neurodegenerative conditions and metabolic disorders. In cancer, autophagy's dual role in either suppressing tumorigenesis or promoting cancer cell survival underscores the importance of understanding its modulation through dietary interventions. Combined with conventional chemotherapy drugs, dietary compounds show synergistic effects in cancer treatment. Furthermore, phytochemicals such as indicaxanthin have been found to epigenetically regulate genes involved in autophagy, offering novel insights into personalized cancer therapies. This comprehensive review has the aim to study the autophagy in a combined view with nutrigenomics effects of some dietary molecules in maintaining cellular homeostasis and responding to pathological stimuli. Overall, the intersection of autophagy and nutrigenomics effect of bioactive compounds holds promise for developing targeted interventions for various diseases, emphasizing the significance of dietary interventions in disease prevention and management.

The effect of Ramadan intermittent fasting on anthropometric, hormonal, metabolic, inflammatory, and oxidative stress markers in pre-and post-menopausal women: a prospective cohort of Saudi women

Background

The menopausal transition significantly affects cardiometabolic health, primarily due to changes in reproductive hormones, particularly decreased estrogen levels and relative androgen excess. Adult Muslim women, both pre-and post-menopausal, are mandated to observe Ramadan intermittent fasting (RIF) every year. Therefore, the current study was designed to investigate RIF's effects on pre-menopausal (PRE-M) and post-menopausal (POST-M) healthy women's cardiometabolic health markers. This study further evaluated the relationship between tested markers and the participant's basic variables, such as BMI and body fatness. Due to differences in physiological and metabolic biomarkers between groups, RIF is likely to impact PRE-M and POST-M women differently.

Methods

This study included 62 healthy women (31 PRE-M, aged 21-42 years, and 31 POST-M, aged 43-68 years) who observed RIF. Anthropometrics, sex hormones, lipid profile, pro-inflammatory (TNF-α), anti-inflammatory (IL-10) cytokines, the oxidative stress markers malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and aging biomarker insulin-like growth factor-1 (IGF-1); all were tested 1 week before and at the fourth week of Ramadan.

Results

Body weight, BMI, waist circumference, body fat percentage (BFP), fat mass, fat mass index, triglycerides, and diastolic blood pressure significantly (p < 0.05) decreased at the end of Ramadan in both groups in comparison to the pre-fasting period. Contrarily, HDL, SOD, GPx, and IL-10 significantly (p < 0.05) increased in both groups. Estrogen levels significantly (p < 0.05) decreased in PRE-M women, whereas significantly (p < 0.05) increased in POST-M women. The progesterone levels, TAC, MDA, and IGF-1 remained unchanged in both groups. TNF-α significantly decreased in both groups, but the magnitude of reduction was higher in PRE-M women. Sex hormones and some metabolic biomarkers, especially in POST-M women, variably exhibited positive or negative relationships to BMI and BFP. RIF may influence the levels of estrogen, TNF-α, and IL-10 through improvements in metabolic health, reductions in body fat, activation of autophagy, modulation of immune responses, and changes in hormonal regulation.

Conclusion

The RIF was generally associated with improved anthropometric, metabolic, inflammatory, and oxidative stress markers in both PRE-M and POST-M healthy women. Adhering to healthy dietary and lifestyle guidelines by pre-and post-menopausal women during Ramadan may foster the health benefits gained.

Human adenovirus type 7 (HAdV-7) infection induces pulmonary vascular endothelial injury through the activation of endothelial autophagy

BACKGROUND

HAdV-7 is a prevalent pathogen that can cause severe pneumonia in children. Previous studies have shown a significant increase in serum levels of vascular permeability factor (VPF/VEGF) and viral load in pediatric patients with fatal HAdV-7 infection, suggesting potential damage to the pulmonary vascular endothelium. Further research is necessary to elucidate the underlying mechanism.

METHODS

The human lung microvascular endothelial cell line-5a and human CD46 mice were used for in vitro and in vivo experiments, respectively. RNA-seq was employed for correlative omics analysis. Viral infection and copy status were examined using transmission electron microscopy to observe virus particles, immunofluorescence to detect the viral protein Hexon, and qPCR to assess HAdV-7 fiber gene copies. Various methods, including ELISAs for VEGF and other injury markers, the CCK8 assay for cell viability, and flow cytometry for endothelium numbers, were employed to evaluate endothelial damage. Acute lung injury severity was evaluated by scoring pathological inflammation and measuring pulmonary vascular permeability. Autophagy activation was assessed by observing autophagosomes and validating marker proteins.

RESULTS

GSEA analysis showed significant enrichment of gene sets related to endothelial functions (barrier, defense, and regeneration) and ALI in the HAdV-7-infected group. GO analysis indicated an enrichment of autophagy-related pathways linked to cell death. Subsequently, successful signs of HAdV-7 infection and replication were observed in the endothelium, including cytopathic effects, intracellular virions, and increased HAdV-7 fiber gene copies. Endothelial injury, including mitochondrial damage, decreased endothelium, and elevated levels of endothelial injury markers such as VEGF, sICAM-1, sVCAM-1, E-selectin, ESM1, MCP1, and IL1β were observed after HAdV-7 infection. Additionally, evidence of leaky lung blood vessels and ALI was observed, including progressive weight loss, elevated pulmonary vascular permeability, and severe lung consolidation. Furthermore, HAdV-7 infection induced autophagosome formation in the endothelium and triggered complete cell autophagy. Importantly, inhibiting autophagic flux reduced VEGF levels and other endothelial injury markers, decreased viral load, improved cell survival rate, alleviated pulmonary vessel leakage, and mitigated lung inflammation.

CONCLUSIONS

HAdV-7 successfully infects pulmonary vascular endothelium and replicates effectively, causing injury to the endothelium, high VEGF expression and viral load in the serum, as well as ALI/ARDS. Autophagy inhibitors can alleviate endothelial injury, inhibit viral replication, relieve leakage from the vasculature, and reduce lung inflammation.

The Underestimated Role of Iron in Frontotemporal Dementia: A Narrative Review

The term frontotemporal dementia (FTD) comprises a group of neurodegenerative disorders characterized by the progressive degeneration of the frontal and temporal lobes of the brain with language impairment and changes in cognitive, behavioral and executive functions, and in some cases motor manifestations. A high proportion of FTD cases are due to genetic mutations and inherited in an autosomal-dominant manner with variable penetrance depending on the implicated gene. Iron is a crucial microelement that is involved in several cellular essential functions in the whole body and plays additional specialized roles in the central nervous system (CNS) mainly through its redox-cycling properties. Such a feature may be harmful under aerobic conditions, since it may lead to the generation of highly reactive hydroxyl radicals. Dysfunctions of iron homeostasis in the CNS are indeed involved in several neurodegenerative disorders, although it is still challenging to determine whether the dyshomeostasis of this essential but harmful metal is a direct cause of neurodegeneration, a contributor factor or simply a consequence of other neurodegenerative mechanisms. Unlike many other neurodegenerative disorders, evidence of the dysfunction in brain iron homeostasis in FTD is still scarce; nonetheless, the recent literature intriguingly suggests its possible involvement. The present review aims to summarize what is currently known about the contribution of iron dyshomeostasis in FTD based on clinical, imaging, histological, biochemical and molecular studies, further suggesting new perspectives and offering new insights for future investigations on this underexplored field of research.

The convergence of mTOR signaling and ethanol teratogenesis

Ethanol is one of the most common teratogens and causes of human developmental disabilities. Fetal alcohol spectrum disorders (FASD), which describes the wide range of deficits due to prenatal ethanol exposure, are estimated to affect between 1.1 % and 5.0 % of births in the United States. Ethanol dysregulates numerous cellular mechanisms such as programmed cell death (apoptosis), protein synthesis, autophagy, and various aspects of cell signaling, all of which contribute to FASD. The mechanistic target of rapamycin (mTOR) regulates these cellular mechanisms via sensing of nutrients like amino acids and glucose, DNA damage, and growth factor signaling. Despite an extensive literature on ethanol teratogenesis and mTOR signaling, there has been less attention paid to their interaction. Here, we discuss the impact of ethanol teratogenesis on mTORC1's ability to coordinate growth factor and amino acid sensing with protein synthesis, autophagy, and apoptosis. Notably, the effect of ethanol exposure on mTOR signaling depends on the timing and dose of ethanol as well as the system studied. Overall, the overlap between the functions of mTORC1 and the phenotypes observed in FASD suggest a mechanistic interaction. However, more work is required to fully understand the impact of ethanol teratogenesis on mTOR signaling.

ATF4/PHGDH mediates the effects of ER stress on cadmium-induced autophagy and glycolysis

Cadmium (Cd) has been classified as a Class I carcinogen, but the mechanism of its carcinogenicity is still unknown. Our previous study demonstrated that 2 μM CdCl2 induced autophagy in A549 cells. In this study, we investigated the role of ATF4/PHGDH in Cd-induced autophagy and increased glycolysis. First, BALB/c mice were subcutaneously injected with A549 cells co-treated with or without Cd and siPHGDH to establish a xenograft tumor model, which demonstrated that PHGDH promotes Cd-induced autophagy in vivo. Cd-exposed A549 cells were treated with siPHGDH and 0.4 mM glycine (Gly), respectively. Western blot analysis and Acridine orange staining revealed that PHGDH promotes Cd-induced autophagy. Using 4-PBA (5 mM), the inhibitor of ER stress, or Tm (0.1 μg/ml), the inducer of ER stress, inhibited Cd-induced PHGDH expression. After co-treatment with siPHGDH, PHGDH was determined to mediate ER stress-induced autophagy. Furthermore, transfection with siATF4 inhibited Tm-induced PHGDH expression. ChIP-qPCR experiments demonstrated the transcription regulatory mechanism of ATF4 on PHGDH. Meanwhile, the role of ER stress/PHGDH/autophagy in Cd-promoted cell migration was explored by scratch assay. Finally, the role of ER stress/PHGDH/autophagy in Cd-induced glycolysis was unveiled. In summary, the transcriptional regulation of PHGDH by ATF4 plays a crucial role in Cd-induced autophagy triggered by ER stress. The axis of ER stress/PHGDH/autophagy is important in Cd-induced cell migration by enhancing glycolysis.

Multiplex genomic tagging of mammalian ATG8s to study autophagy

Atg8 proteins play a crucial role in autophagy. There is a single Atg8 isoform in yeast, while mammals have up to seven homologs categorized into LC3s and GABARAPs. The GABARAP subfamily consists of GABARAP, GABARAPL1, and GABARAPL2/GATE16, implicated in various stages along the pathway. However, the intricacies among GABARAP proteins are complex and require a more precise delineation. Here, we introduce a new cellular platform to study autophagy using CRISPR/Cas9-mediated tagging of endogenous genes of the GABARAP subfamily with different fluorescent proteins. This platform allows robust examination of autophagy by flow cytometry of cell populations and monitoring of GABARAP homologs at single-cell resolution using fluorescence microscopy. Strikingly, the simultaneous labeling of the different endogenous GABARAPs allows the identification and isolation of autophagosomes differentially marked by these proteins. Using this system, we found that the different GABARAPs are associated with different autophagosomes. We argue that this new cellular platform will be crucial in studying the unique roles of individual GABARAP proteins in autophagy and other putative cellular processes.

Ubiquitin regulatory X (UBX) domain-containing protein 6 is essential for autophagy induction and inflammation control in macrophages

Ubiquitin regulatory X (UBX) domain-containing protein 6 (UBXN6) is an essential cofactor for the activity of the valosin-containing protein p97, an adenosine triphosphatase associated with diverse cellular activities. Nonetheless, its role in cells of the innate immune system remains largely unexplored. In this study, we report that UBXN6 is upregulated in humans with sepsis and may serve as a pivotal regulator of inflammatory responses via the activation of autophagy. Notably, the upregulation of UBXN6 in sepsis patients was negatively correlated with inflammatory gene profiles but positively correlated with the expression of Forkhead box O3, an autophagy-driving transcription factor. Compared with those of control mice, the macrophages of mice subjected to myeloid cell-specific UBXN6 depletion exhibited exacerbated inflammation, increased mitochondrial oxidative stress, and greater impairment of autophagy and endoplasmic reticulum-associated degradation pathways. UBXN6-deficient macrophages also exhibited immunometabolic remodeling, characterized by a shift to aerobic glycolysis and elevated levels of branched-chain amino acids. These metabolic shifts amplify mammalian target of rapamycin pathway signaling, in turn reducing the nuclear translocation of the transcription factor EB and impairing lysosomal biogenesis. Together, these data reveal that UBXN6 serves as an activator of autophagy and regulates inflammation to maintain immune system suppression during human sepsis.

HucMSC extracellular vesicles increasing SATB 1 to activate the Wnt/β-catenin pathway in 6-OHDA-induced Parkinson's disease model

Parkinson's disease (PD) is a degenerative disorder of the nervous system characterized by the loss of dopaminergic neurons and damage of neurons in the substantia nigra (SN) and striatum, resulting in impaired motor functions. This study aims to investigate how extracellular vesicles (EVs) derived from human umbilical cord mesenchymal stem cells (HucMSC) regulate Special AT-rich sequence-binding protein-1 (SATB 1) and influence Wnt/β-catenin pathway and autophagy in PD model. The PD model was induced by damaging SH-SY5Y cells and mice using 6-OHDA. According to the study, administering EVs every other day for 14 days improved the motor behavior of 6-OHDA-induced PD mice and reduced neuronal damage, including dopaminergic neurons. Treatment with EVs for 12 hours increased the viability of 6-OHDA-induced SH-SY5Y cells. The upregulation of SATB 1 expression with EV treatment resulted in the activation of the Wnt/β-catenin pathway in PD model and led to overexpression of β-catenin. Meanwhile, the expression of LC3 II was decreased, indicating alterations in autophagy. In conclusion, EVs could mitigate neuronal damage in the 6-OHDA-induced PD model by upregulating SATB 1 and activating Wnt/β-catenin pathway while also regulating autophagy. Further studies on the potential therapeutic applications of EVs for PD could offer new insights and strategies.

Unraveling the mechanisms underlying diabetic cataracts: insights from Mendelian randomization analysis

BACKGROUND

Diabetic cataract (DC) is a major cause of blindness, with its pathogenesis involving oxidative stress and ferroptosis, according to recent studies.

METHODS

We performed a Mendelian Randomization (MR) study using GWAS data to select SNPs and assess the causal link between diabetes and cataracts. DC datasets were analyzed for differential gene expression, WGCNA, and protein-protein interactions to identify key oxidative stress and ferroptosis genes. An SVM-RFE algorithm developed a diagnostic model, and ImmuCellAI analyzed immune infiltration patterns.

RESULTS

MR analysis confirmed diabetes as a cataract risk factor and identified core genes related to oxidative stress and ferroptosis in DC. Four key genes (Hspa5/Nfe2l2/Atf3/Stat3) linked to both processes were discovered. Immune infiltration analysis revealed an imbalance associated with these genes.

CONCLUSIONS

A functional interaction between oxidative stress and ferroptosis genes in DC is suggested, with a 4-gene model, indicating their potential as a 'bridge' in DC pathogenesis.

Obeticholic acid ameliorates sepsis-induced renal mitochondrial damage by inhibiting the NF-κb signaling pathway

Acute kidney injury (AKI), a common complication of sepsis, might be caused by overactivated inflammation, mitochondrial damage, and oxidative stress. However, the mechanisms underlying sepsis-induced AKI (SAKI) have not been fully elucidated, and there is a lack of effective therapies for AKI. To this end, this study aimed to investigate whether obeticholic acid (OCA) has a renoprotective effect on SAKI and to explore its mechanism of action. Through bioinformatics analysis, our study confirmed that the mitochondria might be a critical target for the treatment of SAKI. Thus, a septic rat model was established by cecal ligation puncture (CLP) surgery. Our results showed an evoked inflammatory response via the NF-κB signaling pathway and NLRP3 inflammasome activation in septic rats, which led to mitochondrial damage and oxidative stress. OCA, an Farnesoid X Receptor (FXR) agonist, has shown anti-inflammatory effects in numerous studies. However, the effects of OCA on SAKI remain unclear. In this study, we revealed that pretreatment with OCA can inhibit the inflammatory response by reducing the synthesis of proinflammatory factors (such as IL-1β and NLRP3) via blocking NF-κB and alleviating mitochondrial damage and oxidative stress in the septic rat model. Overall, this study provides insight into the excessive inflammation-induced SAKI caused by mitochondrial damage and evidence for the potential use of OCA in SAKI treatment.

Cepharanthine inhibits the proliferation of glioblastoma cells by blocking the autophagy-lysosomal pathway

Cepharanthine (CEP) is a Stephania cepharantha-derived bioactive alkaloid that can inhibit the progression of numerous tumors. However, the effects and specific mechanisms of CEP performance in glioblastoma (GBM) remain unclear. Thus, this study focused on exploring the effects of CEP on GBM and clarifying the underlying mechanisms. U251 and U87 cells were selected to estimate the anti-GBM effects of CEP, and the possible targets of CEP were analyzed using RNA sequencing (RNA-seq). Validation experiments based on RNA-seq data were performed to clarify the key pathway by which CEP mediates GBM cells response. Results showed that CEP administration successfully inhibited the proliferation and induced the cell cycle arrest and apoptosis of the GBM cells. RNA-seq analysis after CEP administration identified 386 differentially expressed genes, which were highly enriched in the autophagy-lysosomal pathway. Subsequent findings demonstrated that CEP exhibited the potential to curb GBM progression by causing lysosomal and autophagic dysfunction. Taken together, our results indicate that CEP is a potential drug candidate for GBM intervention.

A glance at structural biology in advancing rice blast fungus research

The filamentous fungus Magnaporthe oryzae is widely recognized as a notorious plant pathogen responsible for causing rice blasts. With rapid advancements in molecular biology technologies, numerous regulatory mechanisms have been thoroughly investigated. However, most recent studies have predominantly focused on infection-related pathways or host defence mechanisms, which may be insufficient for developing novel structure-based prevention strategies. A substantial body of literature has utilized cryo-electron microscopy and X-ray diffraction to explore the relationships between functional components, shedding light on the identification of potential drug targets. Owing to the complexity of protein extraction and stochastic nature of crystallization, obtaining high-quality structures remains a significant challenge for the scientific community. Emerging computational tools such as AlphaFold for structural prediction, docking for interaction analysis, and molecular dynamics simulations to replicate in vivo conditions provide novel avenues for overcoming these challenges. In this review, we aim to consolidate the structural biological advancements in M. oryzae, drawing upon mature experimental experiences from other species such as Saccharomyces cerevisiae and mammals. We aim to explore the potential of protein construction to address the invasion and proliferation of M. oryzae, with the goal of identifying new drug targets and designing small-molecule compounds to manage this disease.

RAB37-mediated autophagy guards ovarian homeostasis and function

Loss of ovarian homeostasis is associated with ovary dysfunction and female diseases; however, the underlying mechanisms responsible for the establishment of homeostasis and its function in the ovary have not been fully elucidated. Here, we showed that conditional knockout of Rab37 in oocytes impaired macroautophagy/autophagy proficiency in the ovary and interfered with follicular homeostasis and ovary development in mice. Flunarizine treatment upregulated autophagy, thus rescuing the impairment of follicular homeostasis and ovarian dysfunction in rab37 knockout mice by reprogramming of homeostasis. Notably, both the E2F1 and EGR2 transcription factors synergistically activated Rab37 transcription and promoted autophagy. Thus, RAB37-mediated autophagy ensures ovary function by maintaining ovarian homeostasis.Abbreviations: AMH: anti-Mullerian hormone; ATG: autophagy related; BECN1: beclin 1; cKO: conditional knockout; Cre: cyclization recombination enzyme; dpp: days postpartum; E2: estradiol; E2F1: E2F transcription factor 1; EBF1: EBF transcription factor 1; EGR2: early growth response 2; FSH: follicle stimulating hormone; LH: luteinizing hormone; mpp: months postpartum; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; RAB37: RAB37, member RAS oncogene family; SQSTM1: sequestosome 1; TFEB: transcription factor EB; Zp3: zona pellucida glycoprotein 3.

Pharmacological inhibition of USP14 delays proteostasis-associated aging in a proteasome-dependent but foxo-independent manner

Aging is often accompanied by a decline in proteostasis, manifested as an increased propensity for misfolded protein aggregates, which are prevented by protein quality control systems, such as the ubiquitin-proteasome system (UPS) and macroautophagy/autophagy. Although the role of the UPS and autophagy in slowing age-induced proteostasis decline has been elucidated, limited information is available on how these pathways can be activated in a collaborative manner to delay proteostasis-associated aging. Here, we show that activation of the UPS via the pharmacological inhibition of USP14 (ubiquitin specific peptidase 14) using IU1 improves proteostasis and autophagy decline caused by aging or proteostatic stress in Drosophila and human cells. Treatment with IU1 not only alleviated the aggregation of polyubiquitinated proteins in aging Drosophila flight muscles but also extended the fly lifespan with enhanced locomotive activity via simultaneous activation of the UPS and autophagy. Interestingly, the effect of this drug disappeared when proteasomal activity was inhibited, but was evident upon proteostasis disruption by foxo mutation. Overall, our findings shed light on potential strategies to efficiently ameliorate age-associated pathologies associated with perturbed proteostasis.Abbreviations: AAAs: amino acid analogs; foxo: forkhead box, sub-group O; IFMs: indirect flight muscles; UPS: ubiquitin-proteasome system; USP14: ubiquitin specific peptidase 14.

MST1 interactomes profiling across cell death in esophageal squamous cell carcinoma

Objectives

Resistance to apoptosis in esophageal squamous cell carcinoma (ESCC) constitutes a significant impediment to treatment efficacy. Exploring alternative cell death pathways and their regulatory factors beyond apoptosis is crucial for overcoming drug resistance and enhancing therapeutic outcomes in ESCC.

Methods

Mammalian Ste 20-like kinase 1 (MST1) is implicated in regulating various cell deaths, including apoptosis, autophagy, and pyroptosis. Employing enhanced ascorbate peroxidase 2 (APEX2) proximity labeling coupled with immunoprecipitation-mass spectrometry (IP-MS), we elucidated the interactomes of MST1 across these three cell death paradigms.

Results

Proteomic profiling unveiled the functional roles and subcellular localization of MST1 and its interacting proteins during normal proliferation and various cell death processes. Notably, MST1 exhibited an expanded interactome during cell death compared to normal proliferation and chromosome remodeling functions consistently. In apoptosis, there was a notable increase of mitosis-associated proteins such as INCENP, ANLN, KIF23, SHCBP1 and SUPT16H, which interacted with MST1, alongside decreased expression of the pre-apoptotic protein STK3. During autophagy, the bindings of DNA repair-related proteins CBX8 and m6A reader YTHDC1 to MST1 were enhanced. In pyroptosis, LRRFIP2 and FLII which can inhibit pyroptosis increasingly binding to MST1.

Conclusions

Our findings delineate potential mechanisms through which MST1 and its interactomes regulate cell death, paving the way for further investigation to validate and consolidate these observations.

In situ stoichiometry amounts of p62 and poly-ubiquitin exceed the increase of alpha-synuclein during degeneration of catecholamine cells induced by autophagy inhibition in vitro

Neurodegenerative disorders are typically featured by the occurrence of neuronal inclusions. In the case of Parkinson's disease (PD) these correspond to Lewy bodies (LBs), which are routinely defined as proteinaceous inclusions composed of alpha-synuclein (alpha-syn). In turn, alpha-syn is considered to be the key protein in producing PD and fostering its progression. Recent studies challenged such a concept and emphasized the occurrence of other proteins such as p62 and poly-ubiquitin (Poly-ub) in the composition of LBs, which are also composed of large amounts of tubulo-vesicular structures. All these components, which accumulate within the cytosol of affected neurons in PD, may be the consequence of a dysfunction of major clearing pathways. In fact, autophagy-related systems are constantly impaired in inherited PD and genetic models of PD. The present study was designed to validate whether a pharmacological inhibition of autophagy within catecholamine cells produces cell damage and accumulation of specific proteins and tubulo-vesicular structures. The stoichiometry counts of single proteins, which accumulate within catecholamine neurons was carried out along with the area of tubulo-vesicular structures. In these experimental conditions p62 and Poly-ub accumulation exceeded at large the amounts of alpha-syn. In those areas where Poly-ub and p62 were highly expressed, tubulo-vesicular structures were highly represented compared with surrounding cytosol. The present study confirms new vistas about LBs composition and lends substance to the scenario that autophagy inhibition rather than a single protein dysfunction as key determinant of PD.

Autophagy in oral cancer: Promises and challenges (Review)

Autophagy captures damaged or dysfunctional proteins and organelles through the lysosomal pathway to achieve proper cellular homeostasis. Autophagy possesses distinct characteristics and is given recognized functions in numerous physiological and pathological conditions, such as cancer. Early stage cancer development can be stopped by autophagy. After tumor cells have successfully undergone transformation and progressed to a late stage, the autophagy-mediated system of dynamic degradation and recycling will support cancer cell growth and adaptation to various cellular stress responses while preserving energy homeostasis. In the present study, the dual function that autophagy plays in various oral cancer development contexts and stages, the existing arguments for and against autophagy, and the ways in which autophagy contributes to oral cancer modifications, such as carcinogenesis, drug resistance, invasion, metastasis and self-proliferation, are reviewed. Special attention is paid to the mechanisms and functions of autophagy in oral cancer processes, and the most recent findings on the application of certain conventional drugs or natural compounds as novel agents that modulate autophagy in oral cancer are discussed. Overall, further research is needed to determine the validity and reliability of autophagy promotion and inhibition while maximizing the difficult challenge of increasing cancer suppression to improve clinical outcomes.

High-Intensity Interval Training Mitigates Sarcopenia and Suppresses the Myoblast Senescence Regulator EEF1E1

BACKGROUND

The optimal exercise regimen for alleviating sarcopenia remains uncertain. This study aimed to investigate the efficacy of high-intensity interval training (HIIT) over moderate-intensity continuous training (MICT) in ameliorating sarcopenia.

METHODS

We conducted a randomized crossover trial to evaluate plasma proteomic reactions to acute HIIT (four 4-min high-intensity intervals at 70% maximal capacity alternating with 4 min at 30%) versus MICT (constant 50% maximal capacity) in inactive adults. We explored the relationship between a HIIT-specific protein relative to MICT, identified via comparative proteomic analysis, eukaryotic translation elongation factor 1 epsilon 1 (EEF1E1) and sarcopenia in a paired case-control study of elderly individuals (aged over 65). Young (3 months old) and aged (20 months old) mice were randomized to sedentary, HIIT and MICT groups (five sessions/week for 4 weeks; n = 8 for each group). Measurements included skeletal muscle index, hand grip strength, expression of atrophic markers Atrogin1 and MuRF1 and differentiation markers MyoD, myogenin and MyHC-II via western blotting. We examined the impact of EEF1E1 siRNA and recombinant protein on D-galactose-induced myoblast senescence, measuring senescence-associated β-galactosidase and markers like p21 and p53.

RESULTS

The crossover trial, including 10 sedentary adults (32 years old, IQR 31-32) demonstrated significant alterations in the abundance of 21 plasma proteins after HIIT compared with MICT. In the paired case-control study of 84 older adults (84 years old, IQR 69-81; 52% female), EEF1E1 was significantly increased in those with sarcopenia compared to those without (14.68 [95%CI, 2.02-27.34] pg/mL, p = 0.03) and was associated with skeletal muscle index (R2 = 0.51, p < 0.001) and hand grip strength (R2 = 0.54, p < 0.001). In the preclinical study, aged mice exhibited higher EEF1E1 mRNA and protein levels in skeletal muscle compared to young mice, accompanied by a lower muscle mass and strength, increased cellular senescence and protein degradation markers and reduced muscle differentiation efficiency (all p < 0.05). HIIT reduced EEF1E1 expression and mitigated age-related muscle decline and atrophy in aged mice more effectively than MICT. Notably, EEF1E1 downregulation via siRNA significantly counteracted D-galactose-induced myoblast senescence as evidenced by reduced markers of muscle protein degradation and improved muscle differentiation efficiency (all p < 0.05). Conversely, treatments that increased EEF1E1 levels accelerated the senescence process (p < 0.05). Further exploration indicated that the decrease in EEF1E1 was associated with increased SIRT1 level and enhanced autophagy.

CONCLUSIONS

This study highlights the potential of HIIT as a promising approach to prevent and treat sarcopenia while also highlighting EEF1E1 as a potential intervention target.

A systematic review of salivary biomarkers in Parkinson's disease

The search for reliable and easily accessible biomarkers in Parkinson's disease is receiving a growing emphasis, to detect neurodegeneration from the prodromal phase and to enforce disease-modifying therapies. Despite the need for non-invasively accessible biomarkers, the majority of the studies have pointed to cerebrospinal fluid or peripheral biopsies biomarkers, which require invasive collection procedures. Saliva represents an easily accessible biofluid and an incredibly wide source of molecular biomarkers. In the present study, after presenting the morphological and biological bases for looking at saliva in the search of biomarkers for Parkinson's disease, we systematically reviewed the results achieved so far in the saliva of different cohorts of Parkinson's disease patients. A comprehensive literature search on PubMed and SCOPUS led to the discovery of 289 articles. After screening and exclusion, 34 relevant articles were derived for systematic review. Alpha-synuclein, the histopathological hallmark of Parkinson's disease, has been the most investigated Parkinson's disease biomarker in saliva, with oligomeric alpha-synuclein consistently found increased in Parkinson's disease patients in comparison to healthy controls, while conflicting results have been reported regarding the levels of total alpha-synuclein and phosphorylated alpha-synuclein, and few studies described an increased oligomeric alpha-synuclein/total alpha-synuclein ratio in Parkinson's disease. Beyond alpha-synuclein, other biomarkers targeting different molecular pathways have been explored in the saliva of Parkinson's disease patients: total tau, phosphorylated tau, amyloid-β1-42 (pathological protein aggregation biomarkers); DJ-1, heme-oxygenase-1, metabolites (altered energy homeostasis biomarkers); MAPLC-3beta (aberrant proteostasis biomarker); cortisol, tumor necrosis factor-alpha (inflammation biomarkers); DNA methylation, miRNA (DNA/RNA defects biomarkers); acetylcholinesterase activity (synaptic and neuronal network dysfunction biomarkers); Raman spectra, proteome, and caffeine. Despite a few studies investigating biomarkers targeting molecular pathways different from alpha-synuclein in Parkinson's disease, these results should be replicated and observed in studies on larger cohorts, considering the potential role of these biomarkers in determining the molecular variance among Parkinson's disease subtypes. Although the need for standardization in sample collection and processing, salivary-based biomarkers studies have reported encouraging results, calling for large-scale longitudinal studies and multicentric assessments, given the great molecular potentials and the non-invasive accessibility of saliva.

The clinicopathological significance and potential function of ULK1 in colon cancer

Uncoordinated 51-like kinase 1 (ULK1) is an essential part involved in autophagy to maintain cell viability and homeostasis. Herein, the expression levels of ULK1 in colon cancer (CC) were investigated, and its clinicopathological features and potential function were analyzed. Data of ULK1 were obtained from a public database. UCSC XENA RNAseq data were uniformly processed by using the Toil process. STRING was employed for identification of co-expression genes and development of PPI networks whose interaction scores exceeded 0.4. The level of immune cells for tumor infiltration was calculated by means of single-sample GSEA (ssGSEA) on the basis of mRNA data of CC. The ULK1 expression was upregulated compared with both paired and unpaired normal tissues. The mRNA expression of ULK1 was upregulated in CC patients with lymph node metastasis, lymphatic invasion, and pathological stages of 3 and 4. The disease-specific survival (DSS), progression-free interval (PFI), and the overall survival (OS) of patients with upregulated mRNA expression of ULK1 were drastically reduced. Functionally, any changes related to the biological process of ULK1 may be related to macroautophagy, autophagosome organization and autophagosome assembly. As a co-expressed gene (CEG), ATG101 was up-regulated in CC tissues and indicated poor survival. ULK1 is closely related to immune cells. ULK1 expression is upregulated in CC cells and upregulation of ULK1 may serve as an accurate prognostic factor, thereby providing novel intervention targets for therapy.

Mechanical forces inducing oxaliplatin resistance in pancreatic cancer can be targeted by autophagy inhibition

Pancreatic cancer remains one of the most lethal malignancies, with limited treatment options and poor prognosis. A common characteristic among pancreatic cancer patients is the biomechanically altered tumor microenvironment (TME), which among others is responsible for the elevated mechanical stresses in the tumor interior. Although significant research has elucidated the effect of mechanical stress on cancer cell proliferation and migration, it has not yet been investigated how it could affect cancer cell drug sensitivity. Here, we demonstrated that mechanical stress triggers autophagy activation, correlated with increased resistance to oxaliplatin treatment in pancreatic cancer cells. Our results demonstrate that inhibition of autophagy using hydroxychloroquine (HCQ) enhanced the oxaliplatin-induced apoptotic cell death in pancreatic cancer cells exposed to mechanical stress. The combined treatment of HCQ with losartan, a known modulator of mechanical abnormalities in tumors, synergistically enhanced the therapeutic efficacy of oxaliplatin in murine pancreatic tumor models. Furthermore, our study revealed that the use of HCQ enhanced the efficacy of losartan to alleviate mechanical stress levels and restore blood vessel integrity beyond its role in autophagy modulation. These findings underscore the potential of co-targeting mechanical stresses and autophagy as a promising therapeutic strategy to overcome drug resistance and increase chemotherapy efficacy.

Emerging mechanisms of lipid peroxidation in regulated cell death and its physiological implications

Regulated cell death (RCD) refers to the form of cell death that can be regulated by various biomacromolecules. Each cell death modalities have their distinct morphological changes and molecular mechanisms. However, intense evidences suggest that lipid peroxidation can be the common feature that initiates and propagates the cell death. Excessive lipid peroxidation alters the property of membrane and further damage the proteins and nucleic acids, which is implicated in various human pathologies. Here, we firstly review the classical chain process of lipid peroxidation, and further clarify the current understanding of the myriad roles and molecular mechanisms of lipid peroxidation in various RCD types. We also discuss how lipid peroxidation involves in diseases and how such intimate association between lipid peroxidation-driven cell death and diseases can be leveraged to develop rational therapeutic strategies.

Cardiovascular and nonalcoholic fatty liver disease: Sharing common ground through SIRT1 pathways

As a non-communicable disease, cardiovascular disorders have become the leading cause of death for men and women. Of additional concern is that cardiovascular disease is linked to chronic comorbidity disorders that include nonalcoholic fatty liver disease (NAFLD). NAFLD, also termed metabolic-dysfunction-associated steatotic liver disease, is the greatest cause of liver disease throughout the world, increasing in prevalence concurrently with diabetes mellitus (DM), and can progress to nonalcoholic steatohepatitis that leads to cirrhosis and liver fibrosis. Individuals with metabolic disorders, such as DM, are more than two times likely to experience cardiac disease, stroke, and liver disease that includes NAFLD when compared individuals without metabolic disorders. Interestingly, cardiovascular disorders and NAFLD share a common underlying cellular mechanism for disease pathology, namely the silent mating type information regulation 2 homolog 1 (SIRT1; Saccharomyces cerevisiae). SIRT1, a histone deacetylase, is linked to metabolic pathways through nicotinamide adenine dinucleotide and can offer cellular protection though multiple avenues, including trophic factors such as erythropoietin, stem cells, and AMP-activated protein kinase. Translating SIRT1 pathways into clinical care for cardiovascular and hepatic disease can offer significant hope for patients, but further insights into the complexity of SIRT1 pathways are necessary for effective treatment regimens.

Chinese herbal medicine-derived extracellular vesicles as novel biotherapeutic tools: present and future

Extracellular vesicles (EVs) are phospholipid bilayer-enclosed biological particles that are secreted by almost all living cells including animals, plants, and microorganisms. Chinese herbal medicines (CHM) have a long history of using plant-based remedies to treat and prevent human diseases. Chinese herbal medicine-derived extracellular vesicle (CHMEV) generic term refers to nanoscale membrane structures isolated from medicinal plants such as ginseng, ginger, and Panax notoginseng. In recent years, CHMEVs have garnered substantial attention as a novel class of functional components due to their high bioavailability, safety, easy accessibility, and diverse therapeutic effects, indicating their great potential for development as a new dosage form of CHM. Research on CHMEVs in traditional Chinese medicine (TCM) has become a prominent area of interest, opening new avenues for further exploration into the therapeutic effects and functional mechanisms of CHM. Nonetheless, as an emerging field, there is much unknown about these vesicles, and current research remains inconsistent. The review comprehensively summarizes the biogenesis, isolation methods, and physical, and biochemical characterizations of CHMEVs. Additionally, we highlight their biomedical applications as therapeutic agents and drug delivery carriers, including anti-inflammatory, anticancer, regenerative, and antiaging activities. Finally, we propose current challenges and future perspectives. By summarizing the existing literature, we aim to offer valuable clues and inspiration for future CHMEV research, thereby facilitating research standardization of CHMEVs in the treatment of human diseases and drug discovery.

Interaction between coronaviruses and the autophagic response

In recent years, the emergence and widespread dissemination of the coronavirus SARS-CoV-2 has posed a significant threat to global public health and social development. In order to safely and effectively prevent and control the spread of coronavirus diseases, a profound understanding of virus-host interactions is paramount. Cellular autophagy, a process that safeguards cells by maintaining cellular homeostasis under diverse stress conditions. Xenophagy, specifically, can selectively degrade intracellular pathogens, such as bacteria, fungi, viruses, and parasites, thus establishing a robust defense mechanism against such intruders. Coronaviruses have the ability to induce autophagy, and they manipulate this pathway to ensure their efficient replication. While progress has been made in elucidating the intricate relationship between coronaviruses and autophagy, a comprehensive summary of how autophagy either benefits or hinders viral replication remains elusive. In this review, we delve into the mechanisms that govern how different coronaviruses regulate autophagy. We also provide an in-depth analysis of virus-host interactions, particularly focusing on the latest data pertaining to SARS-CoV-2. Our aim is to lay a theoretical foundation for the development of novel coronavirus vaccines and the screening of potential drug targets.

The Estrogen-Autophagy Axis: Insights into Cytoprotection and Therapeutic Potential in Cancer and Infection

Macroautophagy, commonly referred to as autophagy, is an essential cytoprotective mechanism that plays a significant role in cellular homeostasis. It has emerged as a promising target for drug development aimed at treating various cancers and infectious diseases. However, the scientific community has yet to reach a consensus on the most effective approach to manipulating autophagy, with ongoing debates about whether its inhibition or stimulation is preferable for managing these complex conditions. One critical factor contributing to the variability in treatment responses for both cancers and infectious diseases is estrogen, a hormone known for its diverse biological effects. Given the strong correlations observed between estrogen signaling and autophagy, this review seeks to summarize the intricate molecular mechanisms that underlie the dual cytoprotective effects of estrogen signaling in conjunction with autophagy. We highlight recent findings from studies that involve various ligands, disease contexts, and cell types, including immune cells. Furthermore, we discuss several factors that regulate autophagy in the context of estrogen's influence. Ultimately, we propose a hypothetical model to elucidate the regulatory effects of the estrogen-autophagy axis on cell fate. Understanding these interactions is crucial for advancing our knowledge of related diseases and facilitating the development of innovative treatment strategies.

Phagolysosomes break down the membrane of a non-apoptotic corpse independent of macroautophagy

Cell corpses must be cleared in an efficient manner to maintain tissue homeostasis and regulate immune responses. Ubiquitin-like Atg8/LC3 family proteins promote the degradation of membranes and internal cargo during both macroautophagy and corpse clearance, raising the question how macroautophagy contributes to corpse clearance. Studying the clearance of non-apoptotic dying polar bodies in Caenorhabditis elegans embryos, we show that the LC3 ortholog LGG-2 is enriched inside the polar body phagolysosome independent of autophagosome formation. We demonstrate that ATG-16.1 and ATG-16.2, which promote membrane association of lipidated Atg8/LC3 proteins, redundantly promote polar body membrane breakdown in phagolysosomes independent of their role in macroautophagy. We also show that the lipid scramblase ATG-9 is needed for autophagosome formation in early embryos but is dispensable for timely polar body membrane breakdown or protein cargo degradation. These findings demonstrate that macroautophagy is not required to promote polar body degradation, in contrast to recent findings with apoptotic corpse clearance in C. elegans embryos. Determining how factors regulating Atg8/LC3 promote the breakdown of different types of cell corpses in distinct cell types or metabolic states is likely to give insights into the mechanisms of immunoregulation during normal development, physiology, and disease.

Autophagy modulates Arabidopsis male gametophyte fertility and controls actin organization

Autophagy, a crucial mechanism for cellular degradation, is regulated by conserved autophagy-related (ATG) core proteins across species. Impairments in autophagy result in significant developmental and reproductive aberrations in mammals. However, autophagy is thought to be functionally dispensable in Arabidopsis thaliana since most of the ATG mutants lack severe growth and reproductive defects. Here, we challenge this perception by unveiling a role for autophagy in male gametophyte development and fertility in Arabidopsis. A detailed re-assessment of atg5 and atg7 mutants found that reduced autophagy activity in germinated pollen accompanied by partial aberrations in sperm cell biogenesis and pollen tube growth, leading to compromised seed formation. Furthermore, we revealed autophagy modulates the spatial organization of actin filaments via targeted degradation of actin depolymerization factors ADF7 and Profilin2 in pollen grains and tubes through a key receptor, Neighbor of BRCA1 (NBR1). Our findings advance the understanding of the evolutionary conservation and diversification of autophagy in modulating male fertility in plants contrasting to mammals.

Evolutionary conservation and metabolic significance of autophagy in algae

Autophagy is a highly conserved 'self-digesting' mechanism used in eukaryotes to degrade and recycle cellular components by enclosing them in a double membrane compartment and delivering them to lytic organelles (lysosomes or vacuoles). Extensive studies in plants have revealed how autophagy is intricately linked to essential aspects of metabolism and growth, in both normal and stress conditions, including cellular and organelle homeostasis, nutrient recycling, development, responses to biotic and abiotic stresses, senescence and cell death. However, knowledge regarding autophagic processes in other photosynthetic organisms remains limited. In this review, we attempt to summarize the current understanding of autophagy in algae from a metabolic, molecular and evolutionary perspective. We focus on the composition and conservation of the autophagy molecular machinery in eukaryotes and discuss the role of autophagy in metabolic regulation, cellular homeostasis and stress adaptation in algae. This article is part of the theme issue 'The evolution of plant metabolism'.

Transcription Factor Deformed Wings Is an Atg8a-Interacting Protein That Regulates Autophagy

LC3 (microtubule-associated protein 1 light chain 3, called Atg8 in yeast and Drosophila) is one of the most well-studied autophagy-related proteins. LC3 controls the selectivity of autophagic degradation by interacting with LIR (LC3-interacting region) motifs also known as AIM (Atg8-interacting motifs) on selective autophagy receptors that carry cargo for degradation. Although the function of Atg8 family proteins is primarily cytoplasmic, they are also enriched in the nucleus. Despite the accumulating evidence indicating the presence of Atg8 proteins in the nucleus, the mechanisms by which they are targeted to the nucleus, their interactions with nuclear components, and their nuclear role in remain poorly understood. Here, we used yeast two-hybrid screening, and we identified transcription factor Deformed wings (Dwg) as an Atg8a-interacting protein in Drosophila. Dwg-Atg8a interaction is LIR motif-dependent. We have created Dwg Y129A/I132A LIR mutant flies and shown that they exhibit elevated autophagy, improved resistance to oxidative stress, and starvation. Our results provide novel insights into the transcriptional regulation of autophagy in Drosophila.

Overexpression of autophagy enhancer PACER/RUBCNL in neurons accelerates disease in the SOD1G93A ALS mouse model

Amyotrophic lateral sclerosis (ALS) is a debilitating and fatal paralytic disorder associated with motor neuron death. Mutant superoxide dismutase 1 (SOD1) misfolding and aggregation have been linked to familial ALS, with the accumulation of abnormal wild-type SOD1 species being also observed in postmortem tissue of sporadic ALS cases. Both wild-type and mutated SOD1 are reported to contribute to motoneuron cell death. The autophagic pathway has been shown to be dysregulated in ALS. Recent evidence suggests a dual time-dependent role of autophagy in the progression of the disease. PACER, also called RUBCNL (Rubicon-like), is an enhancer of autophagy and has been found diminished in its levels during ALS pathology in mice and humans. Pacer loss of function disturbs the autophagy process and leads to the accumulation of SOD1 aggregates, as well as sensitizes neurons to death. Therefore, here we investigated if constitutive overexpression of PACER in neurons since early development is beneficial in an in vivo model of ALS. We generated a transgenic mouse model overexpressing human PACER in neurons, which then was crossbred with the mutant SOD1G93A ALS mouse model. Unexpectedly, PACER/SOD1G93A double transgenic mice exhibited an earlier disease onset and shorter lifespan than did littermate SOD1G93A mice. The overexpression of PACER in neurons in vivo and in vitro increased the accumulation of SOD1 aggregates, possibly due to impaired autophagy. These results suggest that similar to Pacer loss-of function, Pacer gain-of function is detrimental to autophagy, increases SOD1 aggregation and worsens ALS pathogenesis. In a wider context, our results indicate the requirement to maintain a fine balance of PACER protein levels to sustain proteostasis.

MicroRNA-mediated autophagy and drug resistance in cancer: mechanisms and therapeutic strategies

This paper provides an exhaustive overview of the intricate interplay between microRNAs (miRNAs) and autophagy in the context of human cancers, underscoring the pivotal role these non-coding RNAs play in modulating autophagic pathways and their implications for cancer development, progression, and resistance to therapy. MiRNAs, as critical regulators of gene expression post-transcription, influence various biological processes, including autophagy, a catabolic mechanism essential for cellular homeostasis, stress response, and survival. The review meticulously delineates the mechanisms through which miRNAs impact autophagy by targeting specific genes and signaling pathways, thereby affecting cancer cell proliferation, metastasis, and response to chemotherapy. It highlights several miRNAs with dual roles, acting either as oncogenes or tumor suppressors based on the cellular context and the specific autophagic pathways they regulate. The paper further explores the therapeutic potential of targeting miRNA-autophagy axis, offering insights into novel strategies for cancer treatment through modulation of this axis. Emphasizing the complexity of the miRNA-autophagy relationship, the review calls for more in-depth studies to unravel the nuanced regulatory networks between miRNAs and autophagy in cancer, which could pave the way for the development of innovative therapeutic interventions and diagnostic tools.

Emerging Role of Ubiquitin Proteasome System and Autophagy in Pediatric Demyelinating Leukodystrophies and Therapeutic Opportunity

Leukodystrophies represent a heterogeneous group of disorders characterized by specific genetic mutations, metabolic abnormalities, and degeneration of white matter in the central nervous system. These disorders are classified into several categories, with X-linked adrenoleukodystrophy (X-ALD), metachromatic leukodystrophy (MLD), and globoid cell leukodystrophy (GLD) being the most prevalent demyelinating leukodystrophies in pediatric populations. Maintaining proteostasis, which is critical for normal cellular function, relies fundamentally on the ubiquitin-proteasome system (UPS) and autophagy for the degradation of misfolded and damaged proteins. Compelling evidence has highlighted the critical roles of UPS and autophagy dysfunction in the pathogenesis of neurodegenerative diseases. Given the complex and poorly understood pathomechanisms underlying demyelinating leukodystrophies, coupled with the pressing need for effective therapeutic strategies, this review aims to systemically analyze the molecular and pathological evidence linking UPS and autophagy dysfunction to demyelinating leukodystrophies, specifically X-ALD and GLD. Furthermore, we will assess the therapeutic potential of autophagy modulators in the management of X-ALD and GLD, with the objective to inspire further research into therapeutic approaches that target autophagy and UPS pathways. Novel therapies that enhance autophagy and UPS function hold promise as complementary regimens in combination therapies aimed at achieving comprehensive correction of the pathogenic mechanisms in demyelinating leukodystrophies.

The phospholamban R14del generates pathogenic aggregates by impairing autophagosome-lysosome fusion

Phospholamban (PLN) plays a crucial role in regulating sarcoplasmic reticulum (SR) Ca2+ cycling and cardiac contractility. Mutations within the PLN gene have been detected in patients with cardiomyopathy, with the heterozygous variant c.40_42delAGA (p.R14del) of PLN being the most prevalent. Investigations into the mechanisms underlying the pathology of PLN-R14del have revealed that cardiac cells from affected patients exhibit pathological aggregates containing PLN. Herein, we performed comprehensive molecular and cellular analyses to delineate the molecular aberrations associated with the formation of these aggregates. We determined that PLN aggregates contain autophagic proteins, indicating inefficient degradation via the autophagy pathway. Our findings demonstrate that the expression of PLN-R14del results in diminished autophagic flux due to impaired fusion between autophagosomes and lysosomes. Mechanistically, this defect is linked to aberrant recruitment of key membrane fusion proteins to autophagosomes, which is mediated in part by changes in Ca2+ homeostasis. Collectively, these results highlight a novel function of PLN-R14del in regulating autophagy, that may contribute to the formation of pathogenic aggregates in patients with cardiomyopathy. Prospective strategies tailored to ameliorate impaired autophagy may hold promise against PLN-R14del disease.

Stenosing Crohn's disease patients display gut autophagy/oxidative stress imbalance

In this pilot study, we assessed the role of autophagy in Crohn's Disease (CD), particularly in patients with a stenosing phenotype. Through the analysis of biopsied specimens from 36 patients, including 11 controls and 25 CD patients, categorized into inflammatory and stenosing groups, we identified a significant reduction in the autophagosomal marker Lc3b-II in patients with active inflammation and stenosis. This was paralleled by an increase in oxidative stress markers, including sNOX2-dp and H2O2, and a decrease in the antioxidant capacity measured by HBA, suggesting an imbalance in autophagy and oxidative stress mechanisms. Additionally, our findings show a correlation between autophagy markers and oxidative stress levels, indicating that autophagy dysfunction may play a pivotal role in CD and in the progression of a stenosing disease phenotype, by failing to eliminate detrimental molecules and pathogenic bacteria, thereby promoting fibrosis. This study is the first to demonstrate in vivo autophagy inhibition in stenosing CD patients and suggests that stimulating autophagic processes could offer a new avenue for the prevention and treatment of intestinal fibrosis in CD. Our results highlight the importance of exploring the interactions between autophagy, the fibrotic process, and the inflammatory cascade, opening avenues for potential therapeutic interventions in CD management.

Dexmedetomidine alleviates intestinal ischemia/reperfusion injury by modulating intestinal neuron autophagy and mitochondrial homeostasis via Nupr1 regulation

Intestinal ischemia/reperfusion injury (I/R) is a common yet challenging-to-treat condition, presenting a significant clinical challenge. This study aims to investigate the protective mechanisms of Dexmedetomidine (Dex) against I/R injury, with a particular focus on its role in regulating autophagy activity in intestinal neurons and maintaining mitochondrial homeostasis. Experimental findings demonstrate that Dex can mitigate intestinal damage induced by I/R through the modulation of autophagy activity and mitochondrial function in intestinal neurons by suppressing the expression of Nupr1. This discovery sheds light on a new molecular mechanism underlying the potential efficacy of Dex in treating intestinal I/R injury, offering valuable insights for clinical therapy.

Lactylation stabilizes TFEB to elevate autophagy and lysosomal activity

The transcription factor TFEB is a major regulator of lysosomal biogenesis and autophagy. There is growing evidence that posttranslational modifications play a crucial role in regulating TFEB activity. Here, we show that lactate molecules can covalently modify TFEB, leading to its lactylation and stabilization. Mechanically, lactylation at K91 prevents TFEB from interacting with E3 ubiquitin ligase WWP2, thereby inhibiting TFEB ubiquitination and proteasome degradation, resulting in increased TFEB activity and autophagy flux. Using a specific antibody against lactylated K91, enhanced TFEB lactylation was observed in clinical human pancreatic cancer samples. Our results suggest that lactylation is a novel mode of TFEB regulation and that lactylation of TFEB may be associated with high levels of autophagy in rapidly proliferating cells, such as cancer cells.

Migfilin promotes autophagic flux through direct interaction with SNAP29 and Vamp8

Autophagy plays a crucial role in cancer cell survival by facilitating the elimination of detrimental cellular components and the recycling of nutrients. Understanding the molecular regulation of autophagy is critical for developing interventional approaches for cancer therapy. In this study, we report that migfilin, a focal adhesion protein, plays a novel role in promoting autophagy by increasing autophagosome-lysosome fusion. We found that migfilin is associated with SNAP29 and Vamp8, thereby facilitating Stx17-SNAP29-Vamp8 SNARE complex assembly. Depletion of migfilin disrupted the formation of the SNAP29-mediated SNARE complex, which consequently blocked the autophagosome-lysosome fusion, ultimately suppressing cancer cell growth. Restoration of the SNARE complex formation rescued migfilin-deficiency-induced autophagic flux defects. Finally, we found depletion of migfilin inhibited cancer cell proliferation. SNARE complex reassembly successfully reversed migfilin-deficiency-induced inhibition of cancer cell growth. Taken together, our study uncovers a new function of migfilin as an autophagy-regulatory protein and suggests that targeting the migfilin-SNARE assembly could provide a promising therapeutic approach to alleviate cancer progression.

NKX3-2 Induces Ovarian Cancer Cell Migration by HDAC6-Mediated Repositioning of Lysosomes and Inhibition of Autophagy

Several soluble factors secreted by the stromal cells and cancer cells within the tumor microenvironment facilitate the progression and invasiveness of ovarian cancer. In ovarian cancer cells, lysophosphatidic acid (LPA) modulates the transcriptome profile and promotes cell invasiveness by the downregulation of autophagy. Here, we further elucidate this mechanism by focusing on the molecular and cellular events regulating autophagy. Transcriptomic and Western blotting analyses revealed NKX3-2, a transcriptional factor, to be among the genes hyperexpressed in LPA-stimulated ovarian cancer cells. Bioinformatic analyses revealed that in ovarian cancer patients, the expression of NKX3-2 positively correlates with genes involved in cell motility and migration, while it negatively correlates with macromolecular catabolic pathways. In various ovarian cancer cell lines, NKX3-2 silencing abrogated LPA-induced cell migration. Mechanistically, this effect is linked to the restoration of the HDAC6-mediated relocation of the lysosomes in the para-golgian area, and this results in an increase in autolysosome formation and the overall upregulation of autophagy. Silencing the expression of ATG7 or BECN1, two autophagy genes, rescued the migratory phenotype of the NKX3-2-silenced ovarian cancer cells. Taken together, these data reveal the mechanism by which the LPA-NKX3-2 axis promotes the invasiveness of ovarian cancer cells and supports the possibility of targeting NKX3-2 to reduce the migratory capacity of cancer cells in response to a permissive microenvironment.

Cysteine Leukotriene Receptor Antagonist-Montelukast Effects on Diabetic Retinal Microvascular Endothelial Cells Curtail Autophagy

Purpose

Diabetic macular edema (DME) is the primary cause of vision impairment in diabetic retinopathy (DR) patients. A previous study has shown the efficacy of montelukast, a cysteinyl leukotriene receptor (CysLTR)1 antagonist, in a diabetic mouse model. This study aims to understand the CysLTR1 signaling in retinal endothelial cells and the impact of montelukast.

Methods

Primary human retinal microvascular endothelial cells (HRECs) challenged with 20 ng/mL TNF-α and 30 mM D-glucose (D-glu) for six to 24 hours served as a model of endothelial activation. HRECs were incubated with L-glucose (L-glu) as an osmotic control. CysLTR1 knockdown and montelukast pretreatment assessed CysLTR1 antagonism. Gene expression, protein expression, and cell-permeable dyes were utilized to measure autophagy and inflammation. Transendothelial electrical resistance (TER) and transendothelial migration of mononuclear leukocytes across HRECs monolayer were measured as a functional assessment of vascular permeability.

Results

Endothelial activation induced by hyperglycemia and inflammation increased CysLTR1 expression, triggering autophagy within two to six hours, IL-1β production, loss of junction integrity, decreased TER, and increased leukocyte migration within six to 24 hours. Pretreatment with montelukast effectively alleviated these effects, demonstrating its dependence on CysLTR1.

Conclusions

Dysfunctional retinal endothelium initiates a self-reinforcing loop of inflammation, autophagy, and compromised integrity associated with heightened CysLTR1 levels. The antagonistic effect of montelukast against CysLTR1 effectively mitigates these detrimental changes. This study reveals CysLTR1 as a potential therapeutic target in treating DME and offers a novel strategy to mitigate detrimental changes in DR.