Hypoxia-induced degradation of FTO promotes apoptosis by unmasking RACK1-mediated activation of MTK1-JNK1/2 pathway

INTRODUCTION

Hypoxia, a condition characterized by inadequate oxygen supply to tissues, triggers various cellular responses, including apoptosis. The RNA demethylase FTO has been shown to exert anti-apoptotic effects, but its functions independent of RNA demethylase-particularly those involving protein-protein interactions-during hypoxia remain unclear.

OBJECTIVES

This study aimed to elucidate the cytoprotective mechanism of FTO in preventing apoptosis under hypoxic stress.

METHODS

NIH/3T3 cells, MEF cells, and mouse granulosa cells were cultured under hypoxia (1 % O2) and treated with inhibitors (chloroquine, MG132, cycloheximide) to identify FTO degradation pathways. RNA interference was used to knock down atg7, nedd4, and fto. Mass spectrometry identified FTO-associated proteins, and their interactions with FTO were analyzed with immunoprecipitation assays. FTO localization was examined through nuclear and cytoplasmic fractionation and fluorescence microscopy. Apoptosis was evaluated by flow cytometry (annexin V/PI). The role of FTO independent of its m6A demethylase activity was determined by inhibiting FTO function using FB23-2 or an H228A/D230A mutant lacking m6A demethylase activity.

RESULTS

Upon hypoxia exposure, FTO relocated from the nucleus to the cytoplasm and underwent degradation through a regulatory pathway in which the E1-like ubiquitin-activating enzyme ATG7 and the E3 ubiquitin ligase NEDD4 cooperatively activated both the ubiquitin-proteasome system (UPS) and the autophagic-lysosomal pathway (ALP) in NIH/3T3 cells, MEF cells, and mouse granulosa cells. Furthermore, knocking down atg7 resulted in FTO accumulation in the cytoplasm, where FTO exerted its protective effect by binding with RACK1, which impairs the interaction between RACK1 and MTK1, thereby blocking activation of JNK1/2 and subsequently preventing apoptosis in hypoxic cells.

CONCLUSION

This study reveals a novel function of cytoplasmic FTO in disrupting the RACK1-MTK1-JNK1/2-apoptosis cascade during hypoxia, positioning the functional context of FTO at the layer of protein-protein interactions, which extends its mechanistic role beyond RNA demethylation.

The Type III Intermediate Filament Protein Peripherin Regulates Lysosomal Degradation Activity and Autophagy

Peripherin belongs to heterogeneous class III of intermediate filaments, and it is the only intermediate filament protein selectively expressed in the neurons of the peripheral nervous system. It has been previously discovered that peripherin interacts with proteins important for the endo-lysosomal system and for the transport to late endosomes and lysosomes, such as RAB7A and AP-3, although little is known about its role in the endocytic pathway. Here, we show that peripherin silencing affects lysosomal abundance but also positioning, causing the redistribution of lysosomes from the perinuclear area to the cell periphery. Moreover, peripherin silencing affects lysosomal activity, inhibiting EGFR degradation and the degradation of a fluorogenic substrate for proteases. Furthermore, we demonstrate that peripherin silencing affects lysosomal biogenesis by reducing the TFEB and TFE3 contents. Finally, in peripherin-depleted cells, the autophagic flux is strongly inhibited. Therefore, these data indicate that peripherin has an important role in regulating lysosomal biogenesis, and positioning and functions of lysosomes, affecting both the endocytic and autophagic pathways. Considering that peripherin is the most abundant intermediate filament protein of peripheral neurons, its dysregulation, affecting its functions, could be involved in the onset of several neurodegenerative diseases of the peripheral nervous system characterized by alterations in the endocytic and/or autophagic pathways.

Rapamycin improves satellite cells' autophagy and muscle regeneration during hypercapnia

Both CO2 retention, or hypercapnia, and skeletal muscle dysfunction predict higher mortality in critically ill patients. Mechanistically, muscle injury and reduced myogenesis contribute to critical illness myopathy, and while hypercapnia causes muscle wasting, no research has been conducted on hypercapnia-driven dysfunctional myogenesis in vivo. Autophagy flux regulates myogenesis by supporting skeletal muscle stem cell - satellite cell - activation, and previous data suggest that hypercapnia inhibits autophagy. We tested whether hypercapnia worsens satellite cell autophagy flux and myogenic potential and if autophagy induction reverses these deficits. Satellite cell transplantation and lineage-tracing experiments showed that hypercapnia undermined satellite cells' activation, replication, and myogenic capacity. Bulk and single-cell sequencing analyses indicated that hypercapnia disrupts autophagy, senescence, and other satellite cell programs. Autophagy activation was reduced in hypercapnic cultured myoblasts, and autophagy genetic knockdown phenocopied these changes in vitro. Rapamycin stimulation led to AMPK activation and downregulation of the mTOR pathway, which are both associated with accelerated autophagy flux and cell replication. Moreover, hypercapnic mice receiving rapamycin showed improved satellite cell autophagy flux, activation, replication rate, and posttransplantation myogenic capacity. In conclusion, we have shown that hypercapnia interferes with satellite cell activation, autophagy flux, and myogenesis, and systemic rapamycin administration improves these outcomes.

Evolutionary patterns and research frontiers in autophagy in podocytopathies: a bibliometric analysis

Introduction

Podocytopathies are a uniquely renal disease syndrome, in which direct or indirect podocyte injury leads to proteinuria or nephrotic syndrome. Of the many factors that contribute to podocytopathies, the abnormal regulation of autophagy, such insufficient or excessive autophagy levels, have been proposed to play a significant role in the occurrence and development of podocytopathies. However, there still has been a lack of systematic and comparative research to elucidate exact role of autophagy in podocytopathies and its current research status. This study aims to utilize bibliometric analysis to clarify the role of autophagy in the pathogenesis of podocytopathies, analyze the research focus in this area, as well as explore the future research trends.

Methods

We retrieved original articles and review papers with respect to autophagy in podocytopathies research published between the year 2008 and 2022 from the Web of Science Core Collection (WOSCC). Then, VOSviewer and CiteSpace software were employed to reveal the leading subjects and generate visual maps of countries/regions, organizations, authors, journals, and keyword networks in this field.

Results and discussion

A total of 825 publications regarding autophagy in podocytopathies published between 2008 and 2022 were included, with China contributing the most followed by the United States and Japan. Professor Koya Daisuke, Professor He Qiang, and Professor Jin Juan are the most prolific researchers in this field. Oxidative stress, the NLRP3 inflammasome, and therapeutic targets were the knowledge base for the research in this special field. Taken together, this bibliometric analysis helps us reveal the current research hotspots and guide future research directions, which provides a reference for scholars to further investigate the role of autophagy in podocytopathies as well as conduct clinical trial with autophagy regulators in podocytopathies.

Evaluation of autophagic and apoptotic markers during infection with animal virus causing hemorrhagic fever in rabbits

Introduction

Lagovirus europaeus/GI.1 and GI.2 cause severe Rabbit Haemorrhagic Disease, and immune processes are among the important pathomechanisms of the disease. Autophagy and apoptosis are two key mechanisms involved in the host antiviral response. Both of these processes have been characterized in infection with GI.1 strains, while data on infection with GI.2 strains still need to be studied. This is particularly important because infection with different strains is associated with a different host immune response profile.

Methods

In this work, we analyzed the expression of selected genes and proteins involved in autophagic flux in the liver, spleen, kidney and peripheral blood, but also apoptotic cell death in the liver and peripheral blood of rabbits infected with the GI.2 strain.

Results

As a result, we showed that autophagy is strongly activated in the liver, spleen and kidney of infected rabbits, and confirmed the activation of apoptosis in the liver.

Discussion

This study highlights the role of apoptosis and autophagy in the immune response in rabbits infected with Lagovirus europaeus/GI.2.

Insight into interplay between PANoptosis and autophagy: novel therapeutics in ischemic stroke

PANoptosis is a novelly defined mode of programmed cell death that involves the activation of multiple cellular death pathways, including pyroptosis, apoptosis, and necroptosis, triggering robust inflammatory reactions. Autophagy is a crucial cellular process that maintains cellular homeostasis and protects cells from various stresses. PANoptosis and autophagy, both vital players in the intricate pathological progression of ischemic stroke (IS), a brain ailment governed by intricate cell death cascades, have garnered attention in recent years for their potential interplay. While mounting evidence hints at a crosstalk between these two processes in IS, the underlying mechanisms remain elusive. Therefore, this review delves into and dissects the intricate mechanisms that underpin the intersection of PANoptosis and autophagy in this devastating condition. In conclusion, the crosstalk between PANoptosis and autophagy in IS presents a promising target for the development of novel stroke therapies. Understanding the interplay between these two pathways offers a much-needed insight into the underlying mechanisms of IS and opens the possibility for new therapeutic strategies.

Socci N, Bale TA, Davis C, Dixon SAH, Zhang C, Wade Clapp D, Neel BG, Parada LF. Hydroxychloroquine prevents resistance and potentiates the antitumor effect of SHP2 inhibition in NF1-associated malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive sarcomas and the primary cause of mortality in patients with neurofibromatosis type 1 (NF1). These malignancies develop within preexisting benign lesions called plexiform neurofibromas (PNs). PNs are solely driven by biallelic NF1 loss eliciting RAS pathway activation, and they respond favorably to MEK inhibitor therapy. MPNSTs harbor additional mutations and respond poorly to MEK inhibition. Our analysis of genetically engineered and orthotopic patient-derived xenograft MPNST models indicates that MEK inhibition has poor antitumor efficacy. By contrast, upstream inhibition of RAS through the protein-tyrosine phosphatase SHP2 reduced downstream signaling and suppressed NF1 MPNST growth, although resistance eventually emerged. To investigate possible mechanisms of acquired resistance, kinomic analyses of resistant tumors were performed, and data analysis identified enrichment of activated autophagy pathway protein kinases. Combining SHP2 inhibition with hydroxychloroquine (HQ) resulted in durable responses in NF1 MPNSTs in both genetic and orthotopic xenograft mouse models. Our studies could be rapidly translated into a clinical trial to evaluate SHP2 inhibition in conjunction with HQ as a unique treatment approach for NF1 MPNSTs.

Changes to the Autophagy-Related Muscle Proteome Following Short-Term Treatment with Ectoine in the Duchenne Muscular Dystrophy Mouse Model mdx

The most severe form of muscular dystrophy (MD), known as Duchenne MD (DMD), remains an incurable disease, hence the ongoing efforts to develop supportive therapies. The dysregulation of autophagy, a degradative yet protective mechanism activated when tissues are under severe and prolonged stress, is critically involved in DMD. Treatments that harness autophagic capacities therefore represent a promising therapeutic approach. Osmolytes are protective organic molecules that regulate osmotic pressure and cellular homeostasis and may support tissue-repairing autophagy. We therefore explored the effects of the osmolyte ectoine in the standard mouse model of DMD, the mdx, focusing on the autophagy-related proteome. Mice were treated with ectoine in their drinking water (150 mg/kg) or through daily intraperitoneal injection (177 mg/kg) until they were 5.5 weeks old. Hind limb muscles were dissected, and samples were prepared for Western blotting for protein quantification and for immunofluorescence for an evaluation of tissue distribution. We report changes in the protein levels of autophagy-related 5 (ATG5), Ser366-phosphorylated sequestosome 1 (SQSTM1), heat shock protein 70 (HSP70), activated microtubule-associated protein 1A/1B-light chain 3 (LC3 II) and mammalian target of rapamycin (mTOR). Most importantly, ectoine significantly improved the balance between LC3 II and SQSTM1 levels in mdx gastrocnemius muscle, and LC3 II immunostaining was most pronounced in muscle fibers of the tibialis anterior from treated mdx. These findings lend support for the further investigation of ectoine as a potential therapeutic intervention for DMD.

Extracellular acyl-CoA-binding protein as an independent biomarker of COVID-19 disease severity

Background

Factors leading to severe COVID-19 remain partially known. New biomarkers predicting COVID-19 severity that are also causally involved in disease pathogenesis could improve patient management and contribute to the development of innovative therapies. Autophagy, a cytosolic structure degradation pathway is involved in the maintenance of cellular homeostasis, degradation of intracellular pathogens and generation of energy for immune responses. Acyl-CoA binding protein (ACBP) is a key regulator of autophagy in the context of diabetes, obesity and anorexia. The objective of our work was to assess whether circulating ACBP levels are associated with COVID-19 severity, using proteomics data from the plasma of 903 COVID-19 patients.

Methods

Somalogic proteomic analysis was used to detect 5000 proteins in plasma samples collected between March 2020 and August 2021 from hospitalized participants in the province of Quebec, Canada. Plasma samples from 903 COVID-19 patients collected during their admission during acute phase of COVID-19 and 295 hospitalized controls were assessed leading to 1198 interpretable proteomic profiles. Levels of anti-SARS-CoV-2 IgG were measured by ELISA and a cell-binding assay.

Results

The median age of the participants was 59 years, 46% were female, 65% had comorbidities. Plasma ACBP levels correlated with COVID-19 severity, in association with inflammation and anti-SARS-CoV-2 antibody levels, independently of sex or the presence of comorbidities. Samples collected during the second COVID-19 wave in Quebec had higher levels of plasma ACBP than during the first wave. Plasma ACBP levels were negatively correlated with biomarkers of T and NK cell responses interferon-γ, tumor necrosis factor-α and interleukin-21, independently of age, sex, and severity.

Conclusions

Circulating ACBP levels can be considered a biomarker of COVID-19 severity linked to inflammation. The contribution of extracellular ACBP to immunometabolic responses during viral infection should be further studied.

Betaine inhibits the stem cell-like properties of hepatocellular carcinoma by activating autophagy via SAM/m6A/YTHDF1-mediated enhancement on ATG3 stability

Background: Stem cell-like properties are known to promote the recurrence and metastasis of hepatocellular carcinoma (HCC), contributing to a poor prognosis for HCC patients. Betaine, an important phytochemical and a methyl-donor related substance, has shown protective effects against liver diseases. However, its effect on HCC stem cell-like properties and the underlying mechanisms remains uninvestigated. Methods: We measured the effects of betaine on the stem cell-like properties and malignant progression of HCC using patient-derived xenografts, cell-derived xenografts, tail vein-lung metastasis models, in vitro limiting dilution, tumor sphere formation, colony formation, and transwell assays. Mechanistic exploration was conducted using western blots, dot blots, methylated RNA immunoprecipitation-qPCR, RNA stability assays, RNA immunoprecipitation-qPCR, RNA pull-down, and gene mutation assays. Results: A cohort study of HCC found that a higher serum concentration of betaine was associated with decreased levels of stemness-related markers. Furthermore, in HCC cells and xenograft mice, betaine suppressed the stem cell-like properties of HCC by activating autophagy. Mechanistically, betaine increased the m6A modification in HCC by producing S-adenosylmethionine (SAM) via betaine-homocysteine S-methyltransferase (BHMT). This increase in SAM subsequently triggered autophagy by enhancing the stability of autophagy-related protein 3 (ATG3) via YTHDF1 in an m6A-dependent manner, thereby inhibiting the stem cell-like properties of HCC cells. Conclusions: These findings indicate that betaine inhibits the stem cell-like properties of HCC via the SAM/m6A/YTHDF1/ATG3 pathway. This study underscores the potential anti-tumor effects of betaine on HCC and offers novel therapeutic prospects for HCC patients.

ATG8 delipidation is not universally critical for autophagy in plants

Intracellular recycling via autophagy is governed by post-translational modifications of the autophagy-related (ATG) proteins. One notable example is ATG4-dependent delipidation of ATG8, a process that plays critical but distinct roles in autophagosome formation in yeast and mammals. Here, we aim to elucidate the specific contribution of this process to autophagosome formation in species representative of evolutionarily distant green plant lineages: unicellular green alga Chlamydomonas reinhardtii, with a relatively simple set of ATG genes, and a vascular plant Arabidopsis thaliana, harboring expanded ATG gene families. Remarkably, the more complex autophagy machinery of Arabidopsis renders ATG8 delipidation entirely dispensable for the maturation of autophagosomes, autophagic flux, and related stress tolerance; whereas autophagy in Chlamydomonas strictly depends on the ATG4-mediated delipidation of ATG8. Importantly, we also demonstrate the distinct impact of different Arabidopsis ATG8 orthologs on autophagosome formation, especially prevalent under nitrogen depletion, providing new insight into potential drivers behind the expansion of the ATG8 family in higher plants. Our findings underscore the evolutionary diversification of the molecular mechanism governing the maturation of autophagosomes in eukaryotic lineages and highlight how this conserved pathway is tailored to diverse organisms.

Targeting CFTR restoring aggrephagy to suppress HSC activation and alleviate liver fibrosis

BACKGROUND AND AIMS

Multiple studies have shown that hepatic fibrosis, a progressive condition that represents the endpoint of various chronic liver diseases, is primarily marked by the extensive activation of hepatic stellate cells (HSCs). However, the exact impact of cystic fibrosis transmembrane conductance regulator (CFTR) on HSCs during the development of hepatic fibrosis remains unclear.

METHODS

In our study, we measured CFTR levels in tissue samples and in HSCs activated by TGF-β stimulation. We established mouse models of liver fibrosis using carbon tetrachloride (CCl4) and bile duct ligation (BDL). In vitro, we investigated the specific mechanisms of CFTR action in HSCs by exploring aggrephagy. We employed co-immunoprecipitation (co-IP) experiments to identify potential downstream targets of CFTR. Finally, through rescue experiments, we examined the impact of GTPase-activating protein - binding protein 1 (G3BP1) on CFTR-mediated activation of hepatic stellate cells.

RESULT

In activated HSCs induced by TGF-β, the reduction of CFTR, various liver fibrosis models, and fibrotic tissue samples were identified. In vitro functional experiments confirmed that CFTR promoted the expression of fibrosis-related markers and aggrephagy in HSCs. Mechanistically, we found that CFTR directly interacts with G3BP1, thereby further promoting the TGF-β/Smad2/3 pathway. The inhibition of G3BP1 caused by CFTR knockdown reduced extracellular matrix deposition, contributing to alleviating liver fibrosis.

CONCLUSION

We emphasize that CFTR activates aggrephagy and promotes HSC activation and hepatic fibrosis by targeting G3BP1, participating in the TGF-β/Smad2/3 signaling pathway. Overall, CFTR has been identified as a potential therapeutic target for liver fibrosis.

Live and let die: analyzing ultrastructural features in cell death

Cell death is an important process that supports morphogenesis during development and tissue homeostasis during adult life by removing damaged or unwanted cells and its dysregulation is associated with numerous disease states. There are different pathways through which a cell can undergo cell death, each relying on peculiar molecular mechanisms and morpho-ultrastructural features. To date, however, while molecular and genetic approaches have been successfully integrated into the field, cell death studies rarely incorporate ultrastructural data from electron microscopy. This review article reports a gallery of original transmission electron microscopy images to describe the ultrastructural features of cells undergoing different types of cell death programs, including necrosis, apoptosis, autophagy, mitotic catastrophe, ferroptosis, methuosis, and paraptosis. TEM has been an important technology in cell biology for well over 50 years and still continues to offer significant advantages in the area of cell death research. TEM allows detailed characterization of the ultrastructural changes within the cell, such as the alteration of organelles and subcellular structures, the nuclear reorganization, and the loss of membrane integrity that enable a distinction between the different forms of cell death based on morphological criteria. Possible pitfalls are also described.

Relationship between autophagy and NLRP3 inflammasome during articular cartilage degradation in oestrogen-deficient rats with streptozotocin-induced diabetes

BACKGROUND

Estrogen deficiency and Diabetes mellitus (DM) cause joint tissue deterioration, although the mechanisms are uncertain. This study evaluated the immunoexpression of autophagy and NLRP3-inflammasome markers, in rat articular cartilage with estrogen deficiency and DM.

METHODS

Twenty rats were sham-operated (SHAM) or ovariectomized (OVX) and equally allocated into four groups: SHAM and OVX groups administered with vehicle solution; SHAM and OVX groups treated with 60 mg/kg/body weight of streptozotocin, intraperitoneally, to induce DM (SHAM-DM and OVX-DM groups). After seven weeks, the rats were euthanized, and their joint knees were processed for paraffin embedding. Sections were stained with haematoxylin-eosin, toluidine blue, safranin-O/fast-green or subjected to picrosirius-red-polarisation method; immunohistochemistry to detect beclin-1 and microtubule-associated protein 1B-light chain 3 (autophagy markers), NLRP3 and interleukin-1β (IL-1β) (inflammasome activation markers), along with matrix metalloproteinase-9 (MMP-9), Nuclear factor-kappa B (NFκB), and Vascular endothelial growth factor A (VEGF-A) were performed.

RESULTS

Deterioration of articular cartilage and subchondral bone were greater in SHAM-DM and OVX-DM groups. Higher percentages of immunolabeled chondrocytes to NLRP3, IL-1β, MMP-9, NFκB, and VEGF-A, as well as lower percentages of chondrocytes immunolabeled to autophagy markers, were noticed in estrogen-deficient and diabetic groups. These differences were greater in the OVX-DM group. Percentages of immunolabeled chondrocytes showed negative correlation between autophagy markers v.s IL-1β, NLRP-3, MMP-9, NFκB, and VEGF-A, along with positive correlation between VEGF-A vs. MMP-9, NFκB, IL-1β, and NLRP3, and MMP-9 vs. NFκB.

CONCLUSIONS

In conclusion, autophagy reduction and NLRP3 inflammasome activation in chondrocytes may be implicated in articular cartilage degradation, under estrogen-deficient and DM conditions. Moreover, the combination of estrogen deficiency and DM may potentiate those effects.

Niraparib perturbs autophagosome-lysosome fusion in pancreatic ductal adenocarcinoma and exhibits anticancer potential against gemcitabine-resistant PDAC

While poly (adenosine diphosphate-ribose) polymerase inhibitors (PARPi) have achieved specific clinical benefits in a subset of pancreatic ductal adenocarcinoma (PDAC) patients, the potential role of the PARPi niraparib in PDAC necessitates further exploration. In this study, we demonstrated that Niraparib exhibited a pronounced inhibitory effect on autophagy in PDAC both in vitro and in vivo. Mechanistically, this inhibition was primarily attributed to niraparib's ability to disrupt the fusion process between autophagosomes and lysosomes, while potentially exerting a relatively minor impact on the initial stage of autophagy. The blockade effect observed may be mediated via modulation of the ERK signaling pathway, and this effect can be mitigated by the application of an ERK inhibitor (FR180204). Notably, the combined treatment regimen of niraparib and gemcitabine failed to elicit the anticipated synergistic effects in wild-type PANC-1 cells, instead exhibiting pronounced antagonistic interactions. However, in gemcitabine-resistant PANC-1 cells, the combination of niraparib and gemcitabine exhibited modest additive effects. Furthermore, niraparib demonstrated a heightened cytotoxic potency against gemcitabine-resistant PANC-1 cells compared to wild-type PANC-1 cells, both in vitro and in vivo. Our research established that niraparib inhibits late-stage autophagy in PDAC, potentially representing a valuable salvage therapy for gemcitabine-resistant PDAC. Further clinical studies are justified.

Doramectin Induces Apoptosis in B16 Melanoma Cells

INTRODUCTION/OBJECTIVE

Metastatic melanoma resists current pharmacological regimens that act through apoptosis. This indicates that therapies acting via non-apoptotic cell-death pathways could be pursued. Doramectin has shown promising results in another cancer of neural crest origin, neuroblastoma, through the inhibition of growth via autophagy. Our research hypothesis is that doramectin induces autophagy in B16F10 melanoma cells.

METHODS

Cells were treated with doramectin (15 uM) or a combination of both doramectin and a cell-death inhibitor, compared to untreated control cells (media), and then analyzed with MTT analysis. Likewise, MDC analysis was completed to detect autophagy involvement with doramectin treatment. Flow cytometry and TUNEL Assay were conducted to observe cell death-related effects.

RESULTS

MTT analysis of doramectin-treated cells displayed a decrease in cell growth compared to control. Apoptotic morphology was prominent in melanoma cells treated with doramectin. Increased autophagy was not detected by fluorometric microscopic analysis. Flow cytometry analysis of doramectin-treated cells showed apoptosis as a major mode of cell death with some necrosis.

CONCLUSION

Doramectin induces a novel cell-death mechanism in melanoma compared to other forms of cancer and should be studied as an effective anti-cancer agent for melanoma treatment.

CT Angiography of the Upper Extremities: Review of Acute Arterial Entities

Historically, evaluation of the upper extremity vasculature was performed using digital subtraction angiography. With the advancement of cross-sectional imaging and submillimeter isotropic data acquisition, CT angiography (CTA) has become an excellent noninvasive diagnostic tool for evaluation of the vasculature of the upper extremities. CTA allows quick evaluation of vessel patency and irregularity and achievement of the anatomic detail needed in preoperative planning. When interpreting CTA of the upper extremities, radiologists must be familiar with the normal vascular anatomy, common vascular anomalies, and pitfalls or artifacts that may mimic or mask abnormality. In this review, the authors provide an overview of the utility of CTA of the upper extremities. Also discussed are CTA techniques and the use of several newer technologies including dual-energy and photon-counting detector CT. The utility of CTA in patients with upper extremity trauma is explored, with a focus on assessing vascular injury. Other vascular abnormalities including infection, acute limb ischemia, and vasculitis are discussed. It is imperative for radiologists to be accustomed to CTA of the upper extremities in diagnosing acute vascular abnormalities and to recognize common pitfalls and mimics of these abnormalities. ©RSNA, 2025 Supplemental material is available for this article.

Dendrobium nobile Lindl. alkaloids protect CCl4-induced acute liver injury via upregulating LAMP1 expression and activating autophagy flux

Dendrobium nobile Lindl. alkaloids (DNLA) are considered important active ingredients of Dendrobium, which have a variety of pharmacological functions. Recent studies indicate that DNLA has beneficial activity in acute liver injury. However, the specific mechanism by which DNLA produces liver protective effects is stills unclear. This study was designed to determine whether regulation of autophagy is involved in the mode of action of DNLA in liver protection. Using CCl4-induced acute liver injury (ALI) and cell culture models, the molecular mechanism of DNLA-mediated autophagy regulation was studied. The results showed that DNLA significantly improved CCl4-induced liver damage and oxidative stress, which was confirmed in AML-12 cells. DNLA promoted autophagy in cells treated with CCl4, manifested by reduced protein expressions of p62 and LC3-II. Fluorescence imaging showed a decrease in the number of autophagosomes in AML-12 cells transfected with mCherry-GFP-LC3B. In addition, DNLA inhibited lysosomal membrane permeabilization by upregulating lysosomal associated membrane protein-1 (LAMP1), thereby promoting autophagy, preventing CCl4-induced mitochondrial dysfunction, and reducing the production of mitochondrial reactive oxygen species (ROS). While pretreatment of cells with lysosomal inhibitor chloroquine weakened mitochondrial protection elicited by DNLA, overexpression of mitochondrial-targeted SOD2 in AML-12 cells significantly blocked CCl4 induced downregulation of LAMP1, thereby improving lysosome integrity and promoting lysosome dependent autophagy, suggesting that there may exist a bidirectional regulation between mitochondrial ROS and lysosome-autophagy activation. Collectively, these results demonstrated that DNLA can protect the liver injury mediated by dysregulation of lysosome-autophagy process through promoting ROS-lysosome-autophagy axis and improving mitochondrial damage.

Monitoring Autophagy with GFP-LC3 Reporter

Autophagy is a key process that maintains cellular homeostasis. Autophagy contributes to various physiological and pathophysiological processes. Development of methodologies for autophagy detection has greatly facilitated the research on autophagy. Among these methodologies, GFP-LC3 reporter has been popularly used in the literature. In this chapter, we will detail step-by-step the GFP-LC3 reporter protocol we have adapted in our lab. This protocol begins with the generation of lentivirus expressing GFP-LC3. Then, the cells are transduced with titrated virus. After selecting the positive cells, single colonies are isolated, characterized, validated, and used in further study.

Inhibition of TrkB kinase activity impairs autophagy in cervical motor neurons of young but not old mice

Ageing-related neuromuscular dysfunction is associated with reduced tropomyosin-related kinase receptor subtype B (TrkB) signalling and accumulation of damaged cytoplasmic aggregates in motor neurons. Autophagy functions to remove these damaged aggregates, and we previously reported increased cervical motor neuron expression of LC3 and p62 in old age. We hypothesized that inhibition of TrkB kinase activity results in an increase in the relative expression of both LC3 and p62 in cervical motor neurons, consistent with impaired progression of autophagy. TrkBF616A mice, which possess a mutation that renders TrkB kinase activity susceptible to rapid inhibition by 1NMPP1, were treated at 6, 18 or 24 months of age with vehicle or 1NMPP1 for 7 days. Immunofluorescence intensity was measured to determine LC3 and p62 expression in choline acetyltransferase-positive motor neurons in the cervical spinal cord. The effect of inhibiting TrkB kinase activity on progression of autophagy was age dependent. In 6-month-old mice, inhibiting TrkB kinase activity increased cervical motor neuron expression of LC3 by 11% (P < 0.001) and p62 by 8% (P = 0.019) compared with vehicle treatment. In 18- and 24-month-old mice, there was no effect of inhibiting TrkB kinase activity on motor neuron LC3 or p62 expression. We provide evidence that inhibition of TrkB signalling impairs progression of autophagy in motor neurons of young mice, similar to the response to ageing. Accordingly, a reduction of TrkB signalling in old age might contribute to neuromuscular dysfunction by impairing progression of autophagy in motor neurons.

The effect of high-intensity exercise in temperate and hot ambient conditions on autophagy and the cellular stress response in young and older females

The process of autophagy is vital in maintaining normal cellular function, especially during exposure to elevated states of physiological stress associated with exercise and hot ambient temperatures. Although prior observations are primarily limited to responses in males, the autophagic response to acute physiological stress in females represents a considerable knowledge gap. Therefore, we assessed autophagy and related pathways of cellular stress in peripheral blood mononuclear cells (PBMCs) from 20 healthy young [n = 10, mean (SD): aged 23 yr (3)] and older [n = 10, aged 69 yr (3)] females in response to 30 min of semi-recumbent high-intensity cycling exercise (70% of predetermined maximal oxygen consumption) in temperate (25°C) and hot (40°C) ambient conditions (15% relative humidity). Mean body temperature (rectal and skin) was measured throughout, whereas cellular responses were evaluated before and after exercise, including up to 6 h of seated recovery. Proteins associated with autophagy and related pathways were assessed via Western blot. Mean body temperature was elevated after exercise in both conditions, with significant elevations observed after exercise in the heat (all, P ≤ 0.05). Although young females displayed signs of elevated autophagic activity [elevations in microtubule-associated light chain 3B (LC3)-II and beclin-2] in response to exercise performed in both temperate and hot ambient conditions (all, P ≤ 0.05), responses were attenuated in older females. This was accompanied by elevations in chaperone-mediated autophagy in young but not in older females in response to exercise independent of ambient temperature. Our findings indicate exercise, with and without ambient heat exposure may stimulate the autophagic response in young but not in older females.NEW & NOTEWORTHY We show for the first time that an acute bout (30 min) of high-intensity intensity exercise stimulates autophagy in young females irrespective of ambient heat exposure. However, older females did not display the same increase in autophagy as their younger counterparts when high-intensity exercise was performed in temperate or hot ambient conditions. Consequently, older females may be at an elevated risk of heat-induced cellular damage during exertional heat stress.

Evidence for cytoprotective autophagy in response to HER2-targeted monoclonal antibodies

The advent of HER2-targeted monoclonal antibodies such as trastuzumab has significantly improved the clinical outcomes for patients with breast cancer overexpressing HER2 and, more recently, also for gastric cancers. However, the development of resistance, as is frequently the case for other antineoplastic modalities, constrains their clinical efficacy. Multiple molecular mechanisms and signaling pathways have been investigated for their potential involvement in the development of resistance to HER2-targeted therapies, among which is autophagy. Autophagy is an inherent cellular mechanism whereby cytoplasmic components are selectively degraded to maintain cellular homeostasis via the generation of energy and metabolic intermediates. Although the cytoprotective form of autophagy is thought to predominate, other forms of autophagy have also been identified in response to chemotherapeutic agents in various tumor models; these include cytotoxic, cytostatic, and nonprotective functional forms of autophagy. In this review, we provide an overview of the autophagic machinery induced in response to HER2-targeted monoclonal antibodies, with a focus on trastuzumab and trastuzumab-emtansine, in an effort to determine whether autophagy targeting or modulation could be translated clinically to increase their effectiveness and/or overcome the development of resistance. SIGNIFICANCE STATEMENT: This manuscript is one in a series of papers that interrogate the role(s) of the autophagy induced in response to antineoplastic agents in various cancer models. This series of papers was developed in an effort to establish whether autophagy targeting or modulation is likely to be an effective adjuvant strategy to increase the efficacy of cancer chemotherapeutic agents. This review explores the relationship between the autophagic machinery and HER2-targeted therapies.

Thrombosis of the Persistent Median Artery: A Rare Cause of Carpal Tunnel Syndrome

Persistent median artery (PMA) is a rare vascular anomaly that, when thrombosed, can compress the median nerve, leading to carpal tunnel syndrome. This case report presents a 29-year-old female with acute right wrist pain, numbness, and tingling in the thumb and index finger. Ultrasound and magnetic resonance imaging (MRI) revealed a thrombosed PMA causing a mass effect on a bifid median nerve. Conservative treatment with anti-edema measures and anticoagulants led to significant symptom resolution within 2 weeks. Untreated thrombosis of the PMA can result in complications such as chronic nerve compression, muscle atrophy, digital ischemia, and permanent loss of hand function. Early diagnosis using Doppler ultrasound and MRI is essential to prevent such outcomes. Although conservative management is often effective, surgical intervention may be needed in persistent or severe cases. This report highlights the importance of recognizing PMA as a rare but significant cause of carpal tunnel syndrome to ensure timely diagnosis and intervention.

Summary of evidence on Traditional Chinese Medicine nursing interventions in hospice care for patients with advanced cancer

BACKGROUND

Patients with advanced cancer experience physical and psychological pain that affects their quality of life. This review aimed to systematically search, evaluate, and summarize the best evidence on Traditional Chinese Medicine (TCM) nursing interventions in hospice care for patients with advanced cancer and to provide an evidence-based foundation for clinical care. The time limit for the search was from 2010 to September 2024.

METHODS

A top-down search of relevant literature was conducted according to the "6S" evidence model, including clinical decisions, guidelines, best practices, evidence summaries, systematic reviews, expert consensus, and randomized controlled trials (RCTs). The literature was evaluated, and evidence was extracted independently by two researchers. The evidence was appraised using the Appraisal of Guidelines Research and Evaluation (AGREE) tool and integrated with an evidence-based team consisting of six members.

RESULTS

Thirty-three publications were included, including four guidelines, two expert consensus, two clinical decisions, two evidence summaries, twenty-one systematic reviews, and two RCTs. Thirty-six indicators of best evidence were summarized from eight areas: TCM therapy, acupuncture therapy, moxibustion therapy, acupressure therapy, music therapy, traditional Chinese exercise therapy, auricular therapy, and aromatherapy.

CONCLUSION

This review summarizes the best evidence for TCM nursing interventions in hospice care for patients with advanced cancer, which can be used by clinical healthcare professionals to develop appropriate TCM nursing interventions in combination with the actual situation and with full consideration of the needs and wishes of the patients and their families to improve the patients' quality of life in advanced stages.

Characterization of Bitter Taste Receptor-Dependent Autophagy in Oral Epithelial Cells

Microbial dysbiosis is an important trigger in the development of oral diseases. Oral keratinocytes or gingival epithelial cells (GECs) offer protection against various microbial insults. Recent studies suggest that GECs expressed higher level of bitter taste receptor 14 (T2R14) compared to other taste receptors and toll-like receptors and act as innate immune sentinels. Macroautophagy or autophagy is a cellular conserved process involved in the regulation of host innate immune responses against microbial infection. Here, we describe a robust method for evaluation of T2R14-dependent autophagy flux in GECs. Autophagy flux was detected using Western blot analysis in GECs and further was confirmed using Acridine Orange-dependent flow cytometry analysis.

Mechanisms of myosin II force generation: insights from novel experimental techniques and approaches

Myosin II is a molecular motor that converts chemical energy derived from ATP hydrolysis into mechanical work. Myosin II isoforms are responsible for muscle contraction and a range of cell functions relying on the development of force and motion. When the motor attaches to actin, ATP is hydrolyzed and inorganic phosphate (Pi) and ADP are released from its active site. These reactions are coordinated with changes in the structure of myosin, promoting the so-called "power stroke" that causes the sliding of actin filaments. The general features of the myosin-actin interactions are well accepted, but there are critical issues that remain poorly understood, mostly due to technological limitations. In recent years, there has been a significant advance in structural, biochemical, and mechanical methods that have advanced the field considerably. New modeling approaches have also allowed researchers to understand actomyosin interactions at different levels of analysis. This paper reviews recent studies looking into the interaction between myosin II and actin filaments, which leads to power stroke and force generation. It reviews studies conducted with single myosin molecules, myosins working in filaments, muscle sarcomeres, myofibrils, and fibers. It also reviews the mathematical models that have been used to understand the mechanics of myosin II in approaches focusing on single molecules to ensembles. Finally, it includes brief sections on translational aspects, how changes in the myosin motor by mutations and/or posttranslational modifications may cause detrimental effects in diseases and aging, among other conditions, and how myosin II has become an emerging drug target.

Autophagy in myocardial ischemia and ischemia/reperfusion

Myocardial infarction (MI) is a life-threatening condition that leads to loss of viable heart tissue. The best way to treat acute MI and limit the infarct size is to re-open the occluded coronary artery and restore the supply of oxygenated and nutrient-rich blood, but reperfusion can cause additional damage. Autophagy is an intracellular process that recycles damaged cytoplasmic components (molecules and organelles) by loading them into autophagosomes and degrading them in autolysosomes. Autophagy is increased in in vivo animal models of permanent ischemia and ischemia/reperfusion but by different molecular mechanisms. While autophagy is protective during permanent ischemia, it is detrimental during ischemia/reperfusion. Its modulation is being investigated as a potential target to reduce reperfusion injury. This review provides a synopsis of the current knowledge about autophagy, summarizes findings specifically in permanent ischemia and ischemia/reperfusion, and briefly discusses the potential implication of experimental findings.

Plant-derived exosome-like nanoparticles for microRNA delivery in cancer treatment

Plant-derived exosome-like nanoparticles (PELNs) are natural nanocarriers and effective delivery systems for plant microRNAs (miRNAs). These PELN-carrying plant miRNAs can regulate mammalian genes across species, thereby increasing the diversity of miRNAs in mammals and exerting multi-target effects that play a crucial role in diseases, particularly cancer. PELNs demonstrate exceptional stability, biocompatibility, and targeting capabilities that protect and facilitate the up-take and cross-kingdom communication of plant miRNAs in mammals. Primarily ingested and absorbed within the gastrointestinal tract of mammals, PELNs preferentially act on the intestine to regulate intestinal homeostasis through functional miRNA activity. The oncogenesis and progression of cancer are closely associated with disruptions in intestinal barriers, ecological imbalances, as well as secondary changes, such as abnormal inflammatory reactions caused by them. Therefore, it is imperative to investigate whether PELNs exert their anticancer effects by regulating mammalian intestinal homeostasis and inflammation. This review aims to elucidate the intrinsic crosstalk relationships and mechanisms of PELNs-mediated miRNAs in maintaining intestinal homeostasis, regulating inflammation and cancer treatment. Furthermore, serving as exceptional drug delivery systems for miRNAs molecules, PELNs offer broad prospects for future applications, including new drug research and development along with drug carrier selection within targeted drug delivery approaches for cancer therapy.

Itaconic acid ameliorates necrotizing enterocolitis through the TFEB-mediated autophagy-lysosomal pathway

Excessive autophagy has been implicated in the pathogenesis of necrotizing enterocolitis (NEC), yet the molecular underpinnings of the autophagy-lysosomal pathway (ALP) in NEC are not well characterized. This study aimed to elucidate alterations within the ALP in NEC by employing RNA sequencing on intestinal tissues obtained from affected infants. Concurrently, we established animal and cellular models of NEC to assess the therapeutic efficacy of itaconic acid (ITA). Our results indicate that the ALP is significantly disrupted in NEC. Notably, ITA was found to modulate the ALP, enhancing autophagic flux and lysosomal function, which consequently alleviated NEC symptoms. Further analysis revealed that ITA's beneficial effects are mediated through the promotion of TFEB nuclear translocation, thereby augmenting the ALP. These findings suggest that targeting the ALP with ITA to modulate TFEB activity may represent a viable therapeutic approach for NEC.

Measurement of Autophagic Activity in Cancer Cells with Flow Cytometric Analysis Using Cyto-ID Staining

Autophagy is an evolutionarily conserved process providing the energy that cells need to survive, especially in stress situations, through catabolic processes. Considering the dual role of autophagy in cancer cells depending on the cellular context, it is crucial to comprehend the effect of drug candidates put forward to prevent cancer through the autophagy pathway. The CYTO-ID® Autophagy Detection Kit allows a rapid, specific and quantitative measurement of autophagic activity at the cellular level using a 488 nm-excitable green fluorescent detection reagent via flow cytometer. In this chapter, we present the CYTO-ID® Autophagy Detection method with a stepwise protocol to monitor the autophagy flux after the application of any compound to suspension cancer cell lines with flow cytometric analysis.

Spermidine Recovers the Autophagy Defects Underlying the Pathophysiology of Cell Trafficking Disorders

Cell trafficking alterations are a growing group of disorders and one of the largest categories of Inherited Metabolic Diseases. They have complex and variable clinical presentation. Regarding neurological manifestations they can present a wide repertoire of symptoms ranging from neurodevelopmental to neurodegnerative disorders. The study of monogenic cell trafficking diseases draws an scenario to understanding this complex group of disorders and to find new therapeutic avenues. Within their pathophysiology, alterations in autophagy outstand as a targetable mechanism of disease, ammended to be modulated through different strategies. In this work we have studied the pathophysiology of two cell trafficking disorders due to mutations in SYNJ1 and NBAS genes. Specifically, we have assesed the autophagic flux in primary fibroblast cultures of the patients and gender/age-matched controls and whether it could be address with a therapeutic purpose. The results have shaped autophagy as one of the hallmarks of the disease. Moreover, we tested in vitro the effect of spermidine, a natural polyamine that acts as an autopagy inductor. Due to the positive results, its efficacy was evaluated later on the patients as well, in a series of n-of-1 clinical trials, achieving improvement in some clinical aspects related to motricity and cognition. Defining autophagy alterations as a common feature in the pathophysiology of cell trafficking disorders is a great step towards their treatment, as it represents a potential actionable target for the personalized treatement of these disorders.

ISO-upregulated BECN1 specifically promotes LC3B-dependent autophagy and anticancer activity in invasive bladder cancer

Isorhapontigenin (ISO), an active compound isolated from the Chinese herb Gnetum Cleistostachyum, exhibited strong preventive and therapeutic effects on bladder cancer (BC) both in vitro and in vivo. Our previous studies revealed that ISO-induced autophagy is crucial for its anti-cancer activity. However, the underlying mechanism remains unclear. Here, we showed that BECN1, an important autophagic protein, was induced by ISO treatment and played crucial roles in ISO-induced late phase of LC3B-dependent, and LC3A-independent autophagy, as well as anti-cancer activity. Downregulation of BECN1 was observed in human BCs and BBN-induced mouse invasive BC tissues, whereas co-treatment with ISO completely reversed BECN1 downregulation in BBN-induced mouse invasive BCs. Consistently, ISO treatment significantly increased BECN1 expression in vitro in a dose- and time-dependent manner. Depletion of BECN1 significantly impaired LC3B-dependent autophagy following ISO treatment, as well as abolished the inhibitory effect of ISO on anchorage-independent growth of human BC cells. Mechanistic studies revealed that BECN1 induction was mediated by ISO downregulation of c-Myc, which resulted in miR-613 reduction, in turn leading to increased NCL translation and further promoting NCL binding to BECN1 mRNA, subsequently stabilizing BECN1 mRNA. In conclusion, our results demonstrate that by activating c-Myc/miR-613/NCL axis, ISO treatment results in BECN1 posttranscriptional upregulation, which specifically initiates LC3B-dependent autophagy and anti-cancer activity. Our findings further strengths our application of ISO for therapy of high-grade invasive BC (HGIBC) patients.

The Chorioallantoic Membrane (CAM) Assay for the Analysis of Starvation-Induced Autophagy

During avian development, the chorioallantoic membrane (CAM) is generated around 4 days after fertilization following the fusion of the allantois and the chorion. The CAM develops rapidly over the next several days and gets heavily vascularized and therefore has been explored widely as a tool for the study of angiogenesis. Additionally, being immunodeficient, the CAM can be used for tumor growth of human origin and its metastasis. Of note, the CAM assay is minimally invasive for the chicken embryo and lacks innervation, which gives this in vivo model a low ethical burden. Here, we describe the protocol for the generation of microtumors from human colorectal cancer cell lines on the CAM, incubated in a nutrient-deficient medium for the activation of autophagy. We show that pre-inoculation markers of autophagy induced through nutrient deficiency are retained in the microtumors generated on the CAM.

Selective autophagy receptor hinders antitumor immunity

Autophagy has a dual role in tumor progression and therapy, influenced by specific receptors and cargo selection. Recent research published in Cell by Herhaus et al. identifies immunity-related GTPase Q (IRGQ) as a novel autophagy receptor that facilitates immune evasion in hepatocellular carcinoma (HCC) by degrading histocompatibility complex class I (MHC-I) molecules, highlighting a potential target to enhance immunotherapy.

Perfluorooctane sulfonate induces hepatotoxicity through promoting inflammation, cell death and autophagy in a rat model

Perfluorooctane sulfonate (PFOS) is reported to cause hepatotoxicity in animals and humans. However, the underlying mechanism by which it affects organelle toxicity in the liver are not well elucidated yet. This study aimed to investigate the mechanisms underlying PFOS-induced hepatic toxicity, focusing on inflammation, cell death, and autophagy. We established a PFOS-exposed Sprague-Dawley (SD) rat liver injury model by intraperitoneal injection of PFOS (1 mg/kg and 10 mg/kg body weight) every alternate day for 15 days. Our findings indicated that PFOS increased liver weight, caused lipid disorder and hepatic steatosis in rats. Meanwhile, PFOS disrupted the structure of mitochondria, increased accumulation of reactive oxygen species (ROS), repressed superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) levels, and elevated malondialdehyde (MDA) and nitric oxide synthase (NOS) amounts. We found PFOS induced inflammation as evidenced by activation of NOD-like receptor protein 3 (NLRP3), Cleaved cysteine-aspartic acid protease (caspase)1, tumor necrosis factor (TNF)α and interleukin (IL)-1β levels. Moreover, PFOS exposure significantly decreased B-cell lymphoma2 (Bcl2)/Bcl2 associated X (Bax) ratio and increased the protein expression of Cleaved caspase-3. Compared with the control group, PFOS upregulated the protein expression of necroptotic markers and autophagy-related proteins. In conclusion, PFOS induced inflammation, cell death, and autophagy through oxidative stress by ROS overload, thereby providing a mechanistic explanation for PFOS-induced hepatotoxicity.

An update on autophagy disorders

Macroautophagy is a highly conserved cellular pathway for the degradation and recycling of defective cargo including proteins, organelles, and macromolecular complexes. As autophagy is particularly relevant for cellular homeostasis in post-mitotic tissues, congenital disorders of autophagy, due to monogenic defects in key autophagy genes, share a common "clinical signature" including neurodevelopmental, neurodegenerative, and neuromuscular features, as well as variable abnormalities of the eyes, skin, heart, bones, immune cells, and other organ systems, depending on the expression pattern and the specific function of the defective proteins. Since the clinical and genetic resolution of EPG5-related Vici syndrome, the paradigmatic congenital disorder of autophagy, the widespread use of massively parallel sequencing has resulted in the identification of a growing number of autophagy-associated disease genes, encoding members of the core autophagy machinery as well as related proteins. Recently identified monogenic disorders linking selective autophagy, vesicular trafficking, and other pathways have further expanded the molecular and phenotypical spectrum of congenital disorders of autophagy as a clinical disease spectrum. Moreover, significant advances in basic research have enhanced the understanding of the underlying pathophysiology as a basis for therapy development. Here, we review (i) autophagy in the context of other intracellular trafficking pathways; (ii) the main congenital disorders of autophagy and their typical clinico-pathological signatures; and (iii) the recommended primary health surveillance in monogenic disorders of autophagy based on available evidence. We further discuss recently identified molecular mechanisms that inform the current understanding of autophagy in health and disease, as well as perspectives on future therapeutic approaches.

The Impact of Obesity on Autophagy in Human Adipose-Derived Mesenchymal Stromal Cells

Mesenchymal stromal cells (MSCs) possess therapeutic properties, which can be blunted by obesity. Autophagy, a cellular recycling process, is essential for MSC function. We investigated the mechanisms by which obesity affects the properties of MSCs, with a focus on autophagy. Adipose tissue was obtained from kidney donors [body mass index (BMI) <30 kg/m2, non-obese] or individuals undergoing weight loss surgery (BMI ≥30 kg/m2, obese) for MSC harvesting (n = 11 each); samples were randomized to sequencing (seq; n = 5 each) or functional studies (n = 6 each). MSCs were sequenced to determine their epigenetic (5-hydroxymethylcytosine) and transcriptomic profiles across autophagy-related genes using hydroxymethylated DNA immunoprecipitation sequencing and mRNA-seq, respectively. Genes with shared trends in both datasets underwent Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR) validation. During functional studies, 2-h starvation was used to induce autophagy in vitro, enabling detection of changes in the protein expression of microtubule-associated protein 1A/1B-light chain-3 and in autophagic flux. Obesity amplified a starvation-induced reduction in autophagic flux in MSCs while promoting earlier generation of new autophagosomes during autophagy initiation. Integrated analysis of the two sequencing datasets revealed 124 differentially hydroxymethylated genes and 30 differentially expressed mRNAs. Among six overlapping autophagy-related genes, three exhibited same-direction trends. Of these, STX12 and SLC25A4 may be implicated in the impact of obesity on autophagic changes in MSCs. Therefore, human obesity may alter autophagy in adipose tissue-derived MSC, and thereby their metabolism and function.

Monitoring Autophagy During Drosophila Oogenesis

Macroautophagy (autophagy hereafter) is an evolutionarily conserved mechanism that maintains the health of cells by degrading toxic proteins and damaged organelles within the lysosomes. Tissues like ovary are made up of heterogeneous cell types and each cell type has distinct levels of autophagy. Studying autophagy in a cell-type specific manner helps better understand the role of autophagy during oogenesis. Here, we describe assays for monitoring autophagy during oogenesis in Drosophila using the two protein markers, Atg8a and Ref(2)P.

TP53AIP1 induce autophagy via the AKT/mTOR signaling pathway in the breast cancer cells

Breast cancer ranks the first in the incidence of female cancer and is the most common cancer threatening the life and health of women worldwide.Tumor protein p53-regulated apoptosis-inducing protein 1 (TP53AIP1) is a pro-apoptotic gene downstream of p53. However, the role of TP53AIP1 in BC needs to be investigated. In vitro and in vivo experiments were conducted to assess the biological functions and associated mechanisms. Several bioinformatics analyses were made, CCK8 assay, wound healing, transwell assays, colony formation assay, EDU, flow cytometry, Immunofluorescence, qRT-PCR and Western-blotting were performed. In our study, we discovered that BC samples had low levels of TP53AIP1 expression, which correlated with a lower survival rate in BC patients. When TP53AIP1 was up-regulated, it caused a decrease in cell proliferation, migration, and invasion. It also induced epithelial-to-mesenchymal transition (EMT) and protective autophagy. Furthermore, the over-expression of TP53AIP1 suppressed tumor growth when tested in vivo. We also noticed that TP53AIP1 up-regulation resulted in decreased levels of phosphorylation in AKT and mTOR, suggesting a mechanistic role. In addition, we performed functional rescue experiments where the activation of AKT was able to counteract the impact of TP53AIP1 on the survival and autophagy in breast cancer cell lines. This suggests that TP53AIP1 acts as an oncogene by controlling the AKT/mTOR pathway. These findings reveal TP53AIP1 as a gene that suppresses tumor growth and triggers autophagy through the AKT/mTOR pathway in breast cancer cells. As a result, TP53AIP1 presents itself as a potential target for novel therapeutic approaches in treating breast cancer.

Axonal distribution of mitochondria maintains neuronal autophagy during aging via eIF2β

Neuronal aging and neurodegenerative diseases are accompanied by proteostasis collapse, while cellular factors that trigger it are not identified. Impaired mitochondrial transport in the axon is another feature of aging and neurodegenerative diseases. Using Drosophila, we found that genetic depletion of axonal mitochondria causes dysregulation of protein degradation. Axons with mitochondrial depletion showed abnormal protein accumulation and autophagic defects. Lowering neuronal ATP levels by blocking glycolysis did not reduce autophagy, suggesting that autophagic defects are associated with mitochondrial distribution. We found that eIF2β was increased by the depletion of axonal mitochondria via proteome analysis. Phosphorylation of eIF2α, another subunit of eIF2, was lowered, and global translation was suppressed. Neuronal overexpression of eIF2β phenocopied the autophagic defects and neuronal dysfunctions, and lowering eIF2β expression rescued those perturbations caused by depletion of axonal mitochondria. These results indicate the mitochondria-eIF2β axis maintains proteostasis in the axon, of which disruption may underly the onset and progression of age-related neurodegenerative diseases.

Oxidative Stress and Autophagy: Unraveling the Hidden Threat to Boars' Fertility

This review systematically examines the influence of oxidative stress on the reproductive function of male livestock, with a particular focus on the modulation of autophagy. Spermatogenesis, a highly precise biological process, is vulnerable to a range of internal and external factors, among which oxidative stress notably disrupts autophagic processes within the testes. This disruption results in diminished sperm quality, impaired testosterone synthesis, and compromised integrity of the blood-testis barrier. Furthermore, this review elucidates the molecular mechanisms by which oxidative stress-induced autophagy dysfunction impairs spermatogenesis and mitochondrial function, consequently reducing sperm motility. These findings aim to provide a theoretical foundation and serve as a reference for improving reproductive performance and sperm quality in livestock.

Chloroquine Affects Presynaptic Membrane Retrieval in Diaphragm Neuromuscular Junctions of Old Mice

Aging disrupts multiple homeostatic processes, including autophagy, a cellular process for the recycling and degradation of defective cytoplasmic structures. Acute treatment with the autophagy inhibitor chloroquine blunts the maximal forces generated by the diaphragm muscle, but the mechanisms underlying neuromuscular dysfunction in old age remain poorly understood. We hypothesized that chloroquine treatment increases the presynaptic retention of the styryl dye FM 4-64 following high-frequency nerve stimulation, consistent with the accumulation of unprocessed bulk endosomes. Diaphragm-phrenic nerve preparations from 24-month-old male and female C57BL/6 × 129 J mice were incubated with FM 4-64 (5 µM) and either chloroquine (50 µM) or vehicle during 80 Hz phrenic nerve stimulation. Acute chloroquine treatment significantly decreased FM 4-64 intensity at diaphragm neuromuscular junctions following 80 Hz phrenic nerve stimulation, consistent with disrupted synaptic vesicle recycling. A similar reduction was evident in regions with the greatest FM 4-64 fluorescence intensity, which most likely surround synaptic vesicle release sites. In the absence of nerve stimulation, chloroquine treatment significantly increased FM 4-64 intensity at diaphragm neuromuscular junctions. These findings highlight the importance of autophagy in regulating presynaptic vesicle retrieval (including vesicle recycling and endosomal processing) and support the role of autophagy impairments in age-related neuromuscular dysfunction.

Dysregulation of mitochondria, apoptosis and mitophagy in Leber's hereditary optic neuropathy with MT-ND1 3635G>A mutation

Leber's hereditary optic neuropathy (LHON) is a maternal inherited disorder, primarily due to mitochondrial DNA (mtDNA) mutations. This investigation aimed to assess the pathogenicity of m.3635G>A alteration known to confer susceptibility to LHON. The disruption of electrostatic interactions among S110 of the MT-ND1 and the side chain of E4, along with the carbonyl backbone of M1 in the NDUFA1, was observed in complex I of cybrids with m.3635G>A. This disturbance affected the complex I assembly activity by changing the mitochondrial respiratory chain composition and function. In addition, the affected cybrids exhibited notable deficiencies in complex I activities, including impaired mitochondrial respiration and depolarization of its membrane potential. Apoptosis was also stimulated in the mutant group, as witnessed by the secretion of cytochrome c and activation of PARP, caspase 3, 7, and 9 compared to the control. Furthermore, the mutant group exhibited decreased levels of autophagy protein light chain 3, accumulation of autophagic substrate P62, and impaired PINK1/Parkin-dependent mitophagy. Overall, the current study has confirmed the crucial involvement of the alteration of the m.3635G>A gene in the development of LHON. These findings contribute to a deeper comprehension of the pathophysiological mechanisms underlying LHON, providing a fundamental basis for further research.

Sesamin alleviates lipid accumulation induced by elaidic acid in L02 cells through TFEB regulated autophagy

Introduction

Non-alcoholic fatty liver disease (NAFLD) is a common chronic disease seriously threatening human health, with limited treatment means, however. Sesamin, a common lignan in sesame seed oil, exhibits anti-inflammatory, antioxidant, and anticancer properties. Our previous studies have shown an ameliorative effect of sesamin on lipid accumulation in human hepatocellular carcinoma (HePG2) induced by oleic acid, with its protective effects unclear in the case of 9-trans-C18:1 elaidic acid (9-trans-C18,1).

Methods

L02 cells, an important tool in scientific researches due to its high proliferation ability, preserved hepatocyte function, and specificity in response to exogenous factors, were incubated with 9-trans-C18:1 to establish an in vitro model of NAFLD in our study. The lipid accumulation in cells and the morphology of mitochondria and autolysosomes were observed by Oil Red O staining and transmission electron microscopy. The effects of sesamin on oxidative stress, apoptosis, mitochondrial function, autophagy as well as related protein levels in L02 cells were also investigated in the presence of 9-trans-C18:1.

Results

The results showed that sesamin significantly accelerated the autophagy flux of L02 cells induced by 9-trans-C18:1 as well as elevated protein levels of transcription factor EB (TFEB) and its downstream target lysosome-associated membrane protein 1(LAMP1), along with up-regulated levels of TFEB and LAMP1 in the nucleus indicated by Immunofluorescence. In addition, PTEN-induced putative kinase 1 and Parkin mediated mitophagy was activated by sesamin. The direct inhibitor Eltrombopag and indirect inhibitor MHY1485 of TFEB reversed the protective effect of sesamin, suggesting the involvement of autophagy in the lipid-lowering process of sesamin.

Discussion

This work suggests that sesamin regulates autophagy through TFEB to alleviate lipid accumulation in L02 cells induced by 9-trans-C18:1, providing a potential target for the prevention and treatment of NAFLD.

Spns1-dependent endocardial lysosomal function drives valve morphogenesis through Notch1-signaling

Autophagy-lysosomal degradation is a conserved homeostatic process considered to be crucial for cardiac morphogenesis. However, both its cell specificity and functional role during heart development remain unclear. Here, we introduced zebrafish models to visualize autophagic vesicles in vivo and track their temporal and cellular localization in the larval heart. We observed a significant accumulation of autolysosomal and lysosomal vesicles in the atrioventricular and bulboventricular regions and their respective valves. We addressed the role of lysosomal degradation based on the Spinster homolog 1 (spns1) mutant (not really started, nrs). n rs larvae displayed morphological and functional cardiac defects, including abnormal endocardial organization, impaired valve formation and retrograde blood flow. Single-nuclear transcriptome analyses revealed endocardial-specific differences in lysosome-related genes and alterations of notch1-signalling. Endocardial-specific overexpression of spns1 and notch1 rescued features of valve formation and function. Altogether, our results reveal a cell-autonomous role of lysosomal processing during cardiac valve formation affecting notch1-signalling.

Autophagy in reproduction and pregnancy-associated diseases

As advantageous as sexual reproduction is during progeny generation, it is also an expensive and treacherous reproductive strategy. The viviparous eukaryote has evolved to survive stress before, during, and after pregnancy. An important and conserved intracellular pathway for the control of metabolic stress is autophagy. The autophagy process occurs in multiple stages through the coordinated action of autophagy-related genes. This review summarizes the evidence that autophagy is an integral component of reproduction. Additionally, we discuss emerging in vitro techniques that will enable cellular and molecular studies of autophagy and its associated pathways in reproduction. Finally, we discuss the role of autophagy in the pathogenesis and progression of several pregnancy-related disorders such as preterm birth, preeclampsia, and intra-uterine growth restriction, and its potential as a therapeutic target.

Nek6 regulates autophagy through the mTOR signaling pathway to alleviate cerebral ischemia-reperfusion injury

OBJECTIVE

Cerebral ischemia-reperfusion injury (CIRI) is a major obstacle to neurological recovery after clinical treatment of ischemic stroke. The aim of this study was to investigate the molecular mechanism of Nek6 alleviating CIRI through autophagy after cerebral ischemia.

MATERIALS AND METHODS

A mouse model of CIRI was constructed by middle cerebral artery occlusion (MCAO). TUNEL staining was used to observe the apoptosis of neuronal cells. The oxygen glucose deprivation/reoxygenation (OGD/R) model was established by hypoxia and reoxygenation. The cell apoptosis and activity was detected. Western blot was performed to detect the expression of autophagy-related proteins, protein kinase B (Akt)/mammalian target of rapamycin (mTOR) and adenosine 5'-monophosphate-activated protein kinase (AMPK)/mTOR signaling pathway-related proteins. Cellular autophagy flux was observed by fluorometric method. NIMA-related kinase 6 (Nek6) mRNA stability was detected by actinomycin D treatment. Methylation RNA immunoprecipitation technique was used to detect Nek6 methylation level.

RESULTS

Nek6 expression was increased in both MCAO and OGD/R models. Overexpression of Nek6 in OGD/R inhibited apoptosis, decreased LC3II and Beclin-1 expression, increased p62 expression, and occurred lysosome dysfunction. Interference with Nek6 has opposite results. Nek6 overexpression promoted p-Akt and p-mTOR protein expressions, inhibited p-AMPK and p-UNC-51-like kinase 1 protein expressions and cell apoptosis, while LY294002, Rapamycin or RSVA405 treatment reversed this effect. Abnormal methyltransferase·like protein 3 (METTL3) expression in CIRI enhanced m6A modification and promoted Nek6 expression level.

CONCLUSION

This study confirmed that Nek6 regulates autophagy and alleviates CIRI through the mTOR signaling pathway, which provides a novel therapeutic strategy for patients with ischemic stroke in the future.

Deptor protects against myocardial ischemia-reperfusion injury by regulating the mTOR signaling and autophagy

Deptor knockout mice were constructed by crossing Deptor Floxp3 mice with myh6 Cre mice, establishing a myocardial ischemia-reperfusion (I/R) model. Deptor knockout mice exhibited significantly increased myocardial infarction size and increased myocardial apoptosis in vivo. ELISA analysis indicated that the expression of CK-MB, LDH, and CtnT/I was significantly higher in the Deptor knockout mice. Deptor siRNA significantly reduced cell activity and increased myocardial apoptosis after I/R-induced in vitro. Deptor siRNA also significantly up-regulated the expression of p-mTOR, p-4EBP1, and p62, and down-regulated the expression of LC3 after I/R induction. Immunofluorescence indicated that LC3 dual fluorescence was weakened by Deptor knockout, and was enhanced after transfection with Deptor-overexpression plasmids. Treatment with OSI027, a co-inhibitor of mTORC1 and mTORC2, in either Deptor knockout mice or Deptor knockout H9C2 cells, resulted in a significant reduction in infarction size and apoptotic cardiomyocytes. ELISA analysis also showed that the expression of CK-MB, LDH, and CtnT/I were significantly down-regulated by treatment with OSI027. CCK-8 cell viability indicated that cell viability was enhanced, and the number of apoptotic cells was decreased in vitro following treatment with OSI027. These results revealed that OSI027 exerts a protective effect on myocardial ischemia/reperfusion injury in both an in vivo and in an in vitro model of I/R. These findings demonstrate that Deptor protects against I/R-induced myocardial injury by inhibiting the mTOR pathway and by increasing autophagy.

Momordicine-I suppresses head and neck cancer growth by modulating key metabolic pathways

One of the hallmarks of cancer is metabolic reprogramming which controls cellular homeostasis and therapy resistance. Here, we investigated the effect of momordicine-I (M-I), a key bioactive compound from Momordica charantia (bitter melon), on metabolic pathways in human head and neck cancer (HNC) cells and a mouse HNC tumorigenicity model. We found that M-I treatment on HNC cells significantly reduced the expression of key glycolytic molecules, SLC2A1 (GLUT-1), HK1, PFKP, PDK3, PKM, and LDHA at the mRNA and protein levels. We further observed reduced lactate accumulation, suggesting glycolysis was perturbed in M-I treated HNC cells. Metabolomic analyses confirmed a marked reduction in glycolytic and TCA cycle metabolites in M-I-treated cells. M-I treatment significantly downregulated mRNA and protein expression of essential enzymes involved in de novo lipogenesis, including ACLY, ACC1, FASN, SREBP1, and SCD1. Using shotgun lipidomics, we found a significant increase in lysophosphatidylcholine and phosphatidylcholine loss in M-I treated cells. Subsequently, we observed dysregulation of mitochondrial membrane potential and significant reduction of mitochondrial oxygen consumption after M-I treatment. We further observed M-I treatment induced autophagy, activated AMPK and inhibited mTOR and Akt signaling pathways and leading to apoptosis. However, blocking autophagy did not rescue the M-I-mediated alterations in lipogenesis, suggesting an independent mechanism of action. M-I treated mouse HNC MOC2 cell tumors displayed reduced Hk1, Pdk3, Fasn, and Acly expression. In conclusion, our study revealed that M-I inhibits glycolysis, lipid metabolism, induces autophagy in HNC cells and reduces tumor volume in mice. Therefore, M-I-mediated metabolic reprogramming of HNC has the potential for important therapeutic implications.

CD40 ligation-induced ERK activation leads to enhanced radiosensitivity in cervical carcinoma cells via promoting autophagy

CD40, a member of the tumor necrosis factor (TNF) receptor superfamily, plays an important role not only in the immune system but also in tumor progression. CD40 ligation reportedly promotes autophagy in immune cells. However, the effects of CD40 ligation on autophagy and its mechanism in solid tumor cells are still unclear. In this study, we find that CD40 ligation promotes autophagosome formation and consequently promotes autophagic flux in cervical cancer cells. Mechanistically, this effect relies on ERK contributing to CD40 ligation-induced ATG13 upregulation by p53. Furthermore, we demonstrate that CD40 ligation-induced autophagy increases the radiosensitivity of cervical cancer cells. Taken together, our results provide new evidence for the involvement of the CD40 pathway in autophagy and radiotherapy in cervical cancer cells.