Dual targeting PD-L1 and 4-1BB to overcome dendritic cell-mediated lenalidomide resistance in follicular lymphoma

Immunomodulatory agent lenalidomide is effective in treating follicular lymphoma (FL). We conducted the first trial of immunotherapy rituximab plus lenalidomide in newly diagnosed FL in China (NCT03715309). One-hundred and fifteen patients were enrolled and treated with rituximab 375 mg/m2 intravenously on day 0 and lenalidomide 25 mg orally on day 1-10 for 6 cycles of induction treatment, as well as lenalidomide for 6 cycles and rituximab for 8 cycles of maintenance treatment. We found that inferior progression-free survival of the patients was significantly associated with elevated serum β2m and lymph node >6 cm, linking to decreased lymphoma cell autophagy and dendritic cell infiltration within the tumor microenvironment. PU.1 transcriptionally downregulated PD-L1 (Programmed death ligand 1) expression and upregulated 4-1BBL (4-1BB ligand) expression, increased lymphoma cell autophagy and dendritic cell maturation via PD-1/PD-L1 and 4-1BB/4-1BBL interaction. In vitro in co-culture system and in vivo in murine xenograft model, knockdown of PU.1 induced lenalidomide resistance, but sensitized FL cells to bi-specific PD-L1/4-1BB antibody or combined treatment of PD-L1 inhibitor and 4-1BB agonist. Collectively, PU.1 is essential in immunomodulatory effect of FL through PD-1/PD-L1- and 4-1BB/4-1BBL-mediated microenvironmental modulation. Dual targeting PD-L1 and 4-1BB could be an alternative immunotherapeutic strategy in the chemo-free era of FL treatment.

Inhibiting Autophagy by Chemicals During SCAPs Osteodifferentiation Elicits Disorganized Mineralization, While the Knock-Out of Atg5/7 Genes Leads to Cell Adaptation

SCAPs (Stem Cells from Apical Papilla), derived from the apex of forming wisdom teeth, extracted from teenagers for orthodontic reasons, belong to the MSCs (Mesenchymal Stromal Cells) family. They have multipotent differentiation capabilities and are a potentially powerful model for investigating strategies of clinical cell therapies. Since autophagy-a regulated self-eating process-was proposed to be essential in osteogenesis, we investigated its involvement in the SCAP model. By using a combination of chemical and genetic approaches to inhibit autophagy, we studied early and late events of osteoblastic differentiation. We showed that blocking the formation of autophagosomes with verteporfin did not induce a dramatic alteration in early osteoblastic differentiation monitored by ALP (alkaline phosphatase) activity. However, blocking the autophagy flux with bafilomycin A1 led to ALP repression. Strikingly, the mineralization process was observed with both compounds, with calcium phosphate (CaP) nodules that remained inside cells under bafilomycin A1 treatment and numerous but smaller CaP nodules after verteporfin treatment. In contrast, deletion of Atg5 or Atg7, two genes involved in the formation of autophagosomes and essential to trigger canonical autophagy, indicated that both genes could be involved differently in the mineralization process with a modification of the ALP activity while final mineralization was not altered.

Microlipophagy from Simple to Complex Eukaryotes

Lipophagy is a selective degradation of lipid droplets in lysosomes or vacuoles. Apart from its role in generating energy and free fatty acids for membrane repair, growth, and the formation of new membranes, lipophagy emerges as a key player in other cellular processes and disease pathogenesis. While fungal, plant, and algal cells use microlipophagy, the most prominent form of lipophagy in animal cells is macrolipophagy. However, recent studies showed that animal cells can also use microlipophagy to metabolize their lipid droplets. Therefore, to no surprise, microlipophagy is conserved from simple unicellular to the most complex multicellular eukaryotes, and many eukaryotic cells can operate both forms of lipophagy. Macrolipophagy is the most studied and better understood at the molecular level, while our understanding of microlipophagy is very sparse. This review will discuss microlipophagy from the perspective of its conservation in eukaryotes and its importance in diseases. To better appreciate the conserved nature of microlipophagy, different organisms and types of cells in which microlipophagy has been reported are also shown in a tabular form. We also point toward the gaps in our understanding of microlipophagy, including the signaling behind microlipophagy, especially in the cells of complex multicellular organisms.

Beclin 1-Mediated Autophagy Is Potentiated by an Interaction with the Neuronal Adaptor FE65

Autophagy is a vital cellular pathway in eukaryotic cells, including neurons, where it plays significant roles in neurodevelopment and maintenance. A crucial step in autophagy is the formation of the class III phosphatidylinositol 3-kinase complex 1 (PI3KC3-C1), which is essential for initiating autophagosome biogenesis. Beclin 1 is the key component of PI3KC3-C1, and its interactors have been reported to affect autophagy. The brain-enriched adaptor protein FE65 has been shown to interact with Alzheimer's disease amyloid precursor protein (APP) to alter the processing of APP. Additionally, FE65 has been implicated in various cellular pathways, including autophagy. We demonstrate here that FE65 positively regulates autophagy. FE65, through its C-terminus, has been shown to interact with Beclin 1. Notably, the overexpression of FE65 enhances Beclin 1-mediated autophagy, whereas this process is attenuated in FE65 knockout cells. Moreover, the stimulatory effect of FE65 on Beclin 1-mediated autophagy is diminished by an FE65 C-terminus deletion mutant that disrupts the FE65-Beclin 1 interaction. Lastly, we have found that the FE65-Beclin 1 interaction modulates the kinase activity of the PI3KC3-C1 complex. Together, we have identified FE65 as a novel Beclin 1 interactor, and this interaction potentiates autophagy.

Progress report on multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) syndrome is an autosomal dominant disorder caused by a germline pathogenic variant in the MEN1 tumor suppressor gene. Patients with MEN1 have a high risk for primary hyperparathyroidism (PHPT) with a penetrance of nearly 100%, pituitary adenomas (PitAd) in 40% of patients, and neuroendocrine neoplasms (NEN) of the pancreas (40% of patients), duodenum, lung, and thymus. Increased MEN1-related mortality is mainly related to duodenal-pancreatic and thymic NEN. Management of PHPT differs from that of patients with sporadic disease, as the surgical approach in MEN1-related PHPT includes near-total or total parathyroidectomy because of multigland hyperplasia in most patients and the consequent high risk of recurrence. NEN management also differs from patients with sporadic disease due to multiple synchronous and metasynchronous neoplasms. In addition, the lifelong risk of developing NEN requires special considerations to avoid excessive surgeries and to minimize damage to the patient's function and well-being. This progress report will outline current insights into surveillance and management of the major clinical manifestation of MEN1 syndrome in children and adults with MEN1 diagnosis. In addition, we will discuss MEN1-like clinical presentation with negative MEN1-genetic workup and future clinical and research directions.

The anti-senescence effect of D-β-hydroxybutyrate in Hutchinson-Gilford progeria syndrome involves progerin clearance by the activation of the AMPK-mTOR-autophagy pathway

D-β-hydroxybutyrate, BHB, has been previously proposed as an anti-senescent agent in vitro and in vivo in several tissues including vascular smooth muscle. Moreover, BHB derivatives as ketone esters alleviate heart failure. Here, we provide evidence of the potential therapeutic effect of BHB on Hutchinson-Gilford progeria syndrome (HGPS), a rare condition characterized by premature aging and heart failure, caused by the presence of progerin, the aberrant protein derived from LMNA/C gene c.1824C > T mutation. We have assessed several hallmarks of HGPS-senescent phenotype in vitro, such as progerin levels, nuclear morphometric aberrations, nucleolar expansion, cellular senescent morphology, SA-βGal-positive cells, H3K9me3 heterochromatin, γH2AX foci, Lamin B1, p21Waf1/Cip1 and p16CDKN2A abundance, and autophagy. Strikingly, BHB improved nuclear and nucleolar morphometrics, diminished the senescence-phenotype, and unstuck autophagy in HGPS as observed by an enhanced degradation of the cargo protein receptor SQSTM1/p62, suggesting the stimulation of the autophagic flux. Additionally, we observed a decrease in progerin abundance, the cause of senescence in HGPS. Furthermore, compound C, an inhibitor of AMPK, and SBI-0206965, an inhibitor of ULK1/2 and AMPK, which prevent autophagy activation, reversed BHB-induced progerin decline as well as its anti-senescent effect in an AMPK-mTORC1 dependent manner. Altogether, these results suggest that the anti-senescence effect of BHB involves progerin clearance by autophagy activation supporting the potential of BHB for HGPS therapeutics and further preclinical trials.

Hypoxia-triggered ERRα acetylation enhanced its oncogenic role and promoted progression of renal cell carcinoma by coordinating autophagosome-lysosome fusion

Estrogen-related receptor α (ERRα) is dysregulated in many types of cancer and exhibits oncogenic activity by promoting tumorigenesis and metastasis of cancer cells. However, its defined role in renal cell carcinoma (RCC) has not been fully elucidated. To reveal the biological function of ERRα and determine the underlying regulatory mechanism in RCC, the quantitative proteomics analysis and mechanism investigation were conducted. The results demonstrated that ERRα promoted the proliferation and tumorigenesis of RCC cells by maintaining lysosome-dependent autophagy flux. ERRα inhibition impaired the transcriptional expression of LAMP2 and VAMP8 and blocked the fusion of autophagosomes with lysosomes, causing the impairment of the autophagy-lysosome pathway and tumor repression in RCC. Moreover, VHL mutant-induced hyperactive hypoxia signaling in RCC triggered p300/CBP-mediated acetylation at the DNA-binding domain of ERRα, and this acetylation promoted its affinity toward targeting DNA and Parkin-mediated ubiquitination and proteasome-dependent degradation. This regulatory model enhanced ERRα transactivation on the expression of LAMP2 and VAMP8, which then maintained autophagy flux and RCC progression. Pharmaceutical inhibition on ERRα acetylation-mediated autophagy-lysosome pathway led to growth repression and sunitinib sensitivity of RCC cells. Taken together, this study uncovered a novel regulatory mechanism of acetylation contributing to the transcriptional performance and the oncogenic role of ERRα in RCC progression by modulating the autophagy-lysosome pathway. These findings might provide a novel approach for the clinical diagnosis and resolution of sunitinib resistance of RCC.

PLIN5 contributes to lipophagy of hepatic stellate cells induced by inorganic arsenic

Arsenic exposure triggers the activation of hepatic stellate cells (HSCs), resulting in liver fibrosis (LF). A significant decrease in lipid droplets marks the activation of HSCs. However, the exact underlying molecular mechanism remains elusive. Lipophagy, a specialized form of selective autophagy, is crucial for the degradation of lipid droplets to maintain intracellular lipid metabolism homeostasis. In this study, arsenic treatment induced lipophagy, as evidenced by the co-localization of LC3 with lipid droplets. Remarkably, arsenic exposure increased the expression levels of Perilipin 5 (PLIN5), a lipid droplet-associated protein, both at the mRNA and protein levels. Moreover, silencing PLIN5 influenced arsenic-induced lipolysis. Consequently, the results of this study indicate that PLIN5 serves as a substrate protein involved in arsenic-induced lipophagy. This research offers a novel perspective on the mechanisms of arsenic-induced HSCs activation and liver lipid metabolism, potentially guiding new strategies for the prevention and treatment of arsenic-related liver diseases.

Diabetes mellitus and glymphatic dysfunction: Roles for oxidative stress, mitochondria, circadian rhythm, artificial intelligence, and imaging

Diabetes mellitus (DM) is a debilitating disorder that impacts all systems of the body and has been increasing in prevalence throughout the globe. DM represents a significant clinical challenge to care for individuals and prevent the onset of chronic disability and ultimately death. Underlying cellular mechanisms for the onset and development of DM are multi-factorial in origin and involve pathways associated with the production of reactive oxygen species and the generation of oxidative stress as well as the dysfunction of mitochondrial cellular organelles, programmed cell death, and circadian rhythm impairments. These pathways can ultimately involve failure in the glymphatic pathway of the brain that is linked to circadian rhythms disorders during the loss of metabolic homeostasis. New studies incorporate a number of promising techniques to examine patients with metabolic disorders that can include machine learning and artificial intelligence pathways to potentially predict the onset of metabolic dysfunction.

Xiaoai Jiedu recipe reduces cell survival and induces apoptosis in hepatocellular carcinoma by stimulating autophagy via the AKT/mTOR pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Xiaoai Jiedu recipe (XJR) is a traditional Chinese medicine formulation used in clinical settings to treat liver cancer. It has shown promising effectiveness by combining herbal and animal-derived ingredients, offering a new approach to cancer treatment. However, its mechanism of action is poorly understood.

AIM OF THE STUDY

The molecular processes underlying the inhibitory effects of the XJR on hepatocellular cancer (HCC) were investigated.

MATERIALS AND METHODS

The primary chemical components of XJR and associated disease targets relevant to HCC were anticipated and compiled using a database. The potential targets and processes by which XJR influenced HCC were investigated using GO and KEGG enrichment analyses, as well as protein-protein interaction (PPI) networks. Transmission electron microscopy, laser confocal microscopy, and Western blotting were used to evaluate autophagy, while CCK-8 assays measured cell viability and Western blotting and flow cytometry evaluated apoptosis. In vivo assays were conducted employing an HCC xenograft mouse model.

RESULTS

Network pharmacology analysis identified 456 intersecting targets between XJR and HCC. The top five active components are quercetin, cholesterol, jaceosidine, eupafolin, and oleanolic acid. The key targets include TP53, AKT1, IL6, EGFR, SRC, HSP90AA1, TNF, IL1B, MYC, and CASP3. Additionally, the autophagy pathway was found to be one of the main pathways through which XJR intervenes in HCC. The increased quantity of autophagosomes and autolysosomes, the overexpression of Beclin1 and LC3A/B-II proteins, and the downregulation of P62 all suggest that XJR stimulated autophagy in HCC cells. Functional tests employing pathway-specific activators and inhibitors and siRNA-based knockdown demonstrated that XJR promoted autophagy by blocking AKT/mTOR signaling. Furthermore, XJR reduced the viability of HCC cells and promoted apoptosis by upregulating apoptosis proteins. Autophagy inhibitors and Beclin1 silencing reversed these effects. Research conducted in vivo showed that XJR activated autophagy through the AKT/mTOR axis, thereby markedly reducing tumor growth and inducing tumor cell demise.

CONCLUSIONS

These studies show that XJR activates autophagy in both cellular and animal models to induce apoptosis and decrease HCC cell proliferation, as shown by network pharmacology and verification assays. Further, these findings provide experimental evidence that the anti-tumor activity of XJR involves autophagy stimulation.

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.

Resilience mechanisms underlying Alzheimer's disease

Alzheimer's disease (AD) consists of two main pathologies, which are the deposition of amyloid plaque as well as tau protein aggregation. Evidence suggests that not everyone who carries the AD-causing genes displays AD-related symptoms; they might never acquire AD as well. These individuals are referred to as non-demented individuals with AD neuropathology (NDAN). Despite the presence of extensive AD pathology in their brain, it was found that NDAN had better cognitive function than was expected, suggesting that they were more resilient (better at coping) to AD due to differences in their brains compared to other demented or cognitively impaired patients. Thus, identification of the mechanisms underlying resilience is crucial since it represents a promising therapeutic strategy for AD. In this review, we will explore the molecular mechanisms underpinning the role of genetic and molecular resilience factors in improving resilience to AD. These include protective genes and proteins such as APOE2, BDNF, RAB10, actin network proteins, scaffolding proteins, and the basal forebrain cholinergic system. A thorough understanding of these resilience mechanisms is crucial for not just comprehending the development of AD but may also open new treatment possibilities for AD by enhancing the neuroprotective pathway and targeting the pathogenic process.

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.

CPT1 deficiency blocks autophagic flux to promote lipid accumulation induced by co-exposure to polystyrene microplastic and cadmium

Introduction

Cadmium (Cd) and polystyrene microplastics (PS-MPs), two ubiquitous environmental contaminants, produce unique synergistic toxicity when co-existing. Key unanswered questions include specific effects on liver function and potential mechanisms.

Methods

In this study, C57BL/6 mice and AML12 cells were used to establish in vivo and in vitro models to elucidate the effects of combined exposure to PS-MPs and Cd on the liver and their mechanisms.

Results

The results showed that the combined effects of PS-MPs and Cd caused significantly more liver damage than exposure alone. As observed by transmission electron microscopy (TEM), the number of autophagosomes was significantly increased in the PS-MPs and Cd co-treated group. In addition, autophagic flux was assayed by RFP-GFP-LC3, a reporter system expressing dual fluorescent proteins, which showed an overwhelming enhancement of autophagic flux damage by co-exposure to PS-MPs and Cd compared to exposure alone. To further investigate the involvement of carnitine palmitoyltransferase1(CPT1) in liver injury induced by co-exposure to Cd and PS-MPs, we co-exposed Baicalin, an activator of CPT1, with PS-MPs and Cd, and showed that activation of CPT1 alleviated the impairment of autophagic fluxes induced by co-exposure of Cd and PS-MPs and further alleviated the changes in lipid accumulation and associated protein levels.

Discussion

In conclusion, the concurrent exposure of PS-MPs and Cd resulted in the blockage of hepatic lipid accumulation and autophagic pathway and further aggravated the toxic damage to the liver. Activation of CPT1 could alleviate the PS-MPs and Cd-induced lipid accumulation and autophagy pathway blockage thus reducing liver injury.

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.

Central SGLT2 mediate sympathoexcitation in hypertensive heart failure via attenuating subfornical organ endothelial cGAS ubiquitination to amplify neuroinflammation: Molecular mechanism behind sympatholytic effect of Empagliflozin

BACKGROUND

Sodium/glucose co-transporter 2 (SGLT2) inhibitors have transformed heart failure (HF) treatment, offering sympatholytic effects whose mechanisms are not fully understood. Our previous studies identified Cyclic GMP-AMP synthase (cGAS)-derived neuroinflammation in the Subfornical organ (SFO) as a promoter of sympathoexcitation, worsening myocardial remodeling in HF. This research explored the role of central SGLT2 in inducing endothelial cGAS-driven neuroinflammation in the SFO during HF and assessed the impact of SGLT2 inhibitors on this process.

METHODS

Hypertensive HF was induced in mice via Angiotensin II infusion for four weeks. SGLT2 expression and localization in the SFO were determined through immunoblotting and double-immunofluorescence staining. AAV9-TIE-shRNA (SGLT2) facilitated targeted SGLT2 knockdown in SFO endothelial cells (ECs), with subsequent analyses via immunoblotting, staining, and co-immunoprecipitation to investigate interactions with cGAS, mitochondrial alterations, and pro-inflammatory pathway activation. Renal sympathetic nerve activity and heart rate variability were measured to assess sympathetic output, alongside evaluations of cardiac function in HF mice.

RESULTS

In HF model mice, SGLT2 levels are markedly raised in SFO ECs, disrupting mitochondrial function and elevating oxidative stress. SGLT2 knockdown preserved mitochondrial integrity and function, reduced inflammation, and highlighted the influence of SGLT2 on mitochondrial health. SGLT2's interaction with cGAS prevented its ubiquitination and degradation, amplifying neuroinflammation and HF progression. Conversely, Empagliflozin counteracted these effects, suggesting that targeting the SGLT2-cGAS interaction as a novel HF treatment avenue.

CONCLUSION

This study revealed that SGLT2 directly reduced cGAS degradation in brain ECs, enhancing neuroinflammation in the SFO, and promoting sympathoexcitation and myocardial remodeling. The significance of the central SGLT2-cGAS interaction in cardiovascular disease mechanisms is emphasized.

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.

Mitochondria-targeting therapeutic strategies for chronic kidney disease

Chronic kidney disease (CKD) is a multifactorial health issue characterised by kidney impairment that has significant morbidity and mortality in the global population. Current treatments for CKD fail to prevent progression to end-stage kidney disease, where management is limited to renal replacement therapy or kidney transplantation. Mitochondrial dysfunction has been implicated in the pathogenesis of CKD and can be broadly categorised into abnormalities related to excessive oxidative stress, reduced mitochondrial biogenesis, excess mitochondrial fission and dysregulated mitophagy. Mitochondria-targeting therapeutic strategies target many of the outlined mechanisms of mitochondrial dysfunction, and an overview of recent evidence for mitochondria-targeting therapeutic strategies is explored in this review, including naturally derived compounds and novel approaches such as fusion proteins. Mitochondria-targeting therapeutic strategies using these approaches show the potential to stabilise or improve renal function, and clinical studies are needed to further confirm their safety and efficacy in human contexts.

DAXX is associated with early recurrence of pancreatic neuroendocrine tumors after R0 resection

INTRODUCTION

ATRX, DAXX, MEN1, and PTEN mutations are proposed drivers of pancreatic neuroendocrine tumor tumorigenesis and independent prognostic factors for metastasis and mortality. However, their implications after R0 resection remain debated. Thus, we sought to identify genomic signatures of pancreatic neuroendocrine tumor disease-specific mortality and recurrence after surgery for curative intent.

METHODS

Pancreatic neuroendocrine tumor patients who underwent whole exome sequencing with available survival data were identified using cBioPortal. Clinicopathologic variables, genomics, and outcomes were analyzed.

RESULTS

Seventy patients who underwent R0 resection were identified. Forty-five of 70 patients were disease free at last follow-up, whereas 25 of 70 patients had disease-specific mortality or recurrent disease and therefore were categorized as part of the recurrent cohort. There were no significant differences in age (P = .245), sex (P = .201), or median follow-up (38.9 vs 33.7 months, P = .122) between groups. Clinicopathologically, the recurrent cohort had significantly greater tumor size (median 5.0 cm vs 3.2 cm, P = .012) and were more likely to have vascular invasion (88% vs 40%, P = .000), positive lymph nodes (68.0% vs 35.6%, P = .013), and metastatic disease (44% vs 4.4%, P < .000). For both cohorts, most tumors were well or moderately differentiated. Tumor mutation burden was greater in the recurrent cohort (median 0.77 vs 0.43 mutations/Mb, P = .004). DAXX mutations were more frequent in the recurrent cohort (36% vs 11%, P = .026) and in those with vascular invasion (51% vs 92%, P = .010).

CONCLUSION

Our analysis demonstrated the prognostic significance of DAXX mutations after curative-intent surgery. Future studies investigating DAXX mutations as a biomarker for aggressive features to guide treatment are warranted.

Aptamer BT200 is protective against myocardial ischemia-reperfusion injury in mice

BACKGROUND

Myocardial ischemia-reperfusion (MI/R) injury tends to affect cardiac function and leads to poor patient prognosis, and there is still no effectively targeted drug to develop anti-von Willebrand factor (VWF) aptamer in acute coronary heart disease. However, the newly anti-VWF aptamer BT200 is applied not only for stroke and hemophilia but also for antithrombolism function in clinical development. The role of BT200 in acute myocardial injury during MI/R is still unknown.

OBJECTIVES

To investigate the cardioprotective effect of aptamer BT200 in a mouse model of MI/R.

METHODS

C57BL/6 mice were subjected to 30-minute ischemia and 24-hour reperfusion to establish MI/R model. Mice were treated with intravenous injection of cy3-labeled BT200 and were observed by an in vivo imaging system at different time points. Then, mice were sampled and evaluated by echocardiography, Evans triphenyltetrazolium chloride staining, histopathologic, western blotting, and real-time quantitative polymerase chain reaction assays to detect cardiac injury and inflammation response after 24-hour reperfusion.

RESULTS

BT200 aptamer can enter and infiltrate into the ischemic myocardium after 24-hour reperfusion. BT200 was shown to inhibit VWF A1 activity and prolong bleeding time in MI/R mice. Moreover, BT200-treated mice had a significant reduction in infarct size and an improvement in cardiac function post-MI/R. BT200 treatment can also alleviate MI/R-induced microvascular obstruction, inflammation response, and cardiomyocyte apoptosis.

CONCLUSION

Pharmacologic targeting of VWF with BT200 alleviates acute MI/R injury in a murine model and may be a novel therapy strategy for acute myocardial infarction.

Mitochondrial bioenergetics stimulates autophagy for pathological MAPT/Tau clearance in tauopathy neurons

Hyperphosphorylation and aggregation of MAPT (microtubule-associated protein tau) is a pathogenic hallmark of tauopathies and a defining feature of Alzheimer disease (AD). Pathological MAPT/tau is targeted by macroautophagy/autophagy for clearance after being sequestered within autophagosomes, but autophagy dysfunction is indicated in tauopathy. While mitochondrial bioenergetic deficits have been shown to precede MAPT/tau pathology in tauopathy brains, it is unclear whether energy metabolism deficiency is involved in the pathogenesis of autophagy defects. Here, we reveal that stimulation of anaplerotic metabolism restores defective oxidative phosphorylation (OXPHOS) in tauopathy neurons which, strikingly, leads to pronounced MAPT/tau clearance by boosting autophagy functionality through enhancements of mitochondrial biosynthesis and supply of phosphatidylethanolamine for autophagosome biogenesis. Furthermore, early anaplerotic stimulation of OXPHOS elevates autophagy activity and attenuates MAPT/tau pathology, thereby counteracting memory impairment in tauopathy mice. Taken together, our study sheds light on a pivotal role of mitochondrial bioenergetic deficiency in tauopathy-related autophagy defects and suggests a new therapeutic strategy to prevent the buildup of pathological MAPT/tau in AD and other tauopathy diseases.Abbreviation: AA: antimycin A; AD, Alzheimer disease; ATP, adenosine triphosphate; AV, autophagosome/autophagic vacuole; AZ, active zone; Baf-A1: bafilomycin A1; CHX, cycloheximide; COX, cytochrome c oxidase; DIV, days in vitro; DRG, dorsal root ganglion; ETN, ethanolamine; FRET, Förster/fluorescence resonance energy transfer; FTD, frontotemporal dementia; Gln, glutamine; HA: hydroxylamine; HsMAPT/Tau, human MAPT; IMM, inner mitochondrial membrane; LAMP1, lysosomal-associated membrane protein 1; LIs, lysosomal inhibitors; MDAV, mitochondria-derived autophagic vacuole; MmMAPT/Tau, murine MAPT; NFT, neurofibrillary tangle; OCR, oxygen consumption rate; Omy: oligomycin; OXPHOS, oxidative phosphorylation; PPARGC1A/PGC-1alpha: peroxisome proliferative activated receptor, gamma, coactivator 1 alpha; PE, phosphatidylethanolamine; phospho-MAPT/tau, hyperphosphorylated MAPT; PS, phosphatidylserine; PISD, phosphatidylserine decarboxylase;SQSTM1/p62, sequestosome 1; STX1, syntaxin 1; SYP, synaptophysin; Tg, transgenic; TCA, tricarboxylic acid; TEM, transmission electron microscopy.

tsRNA-5006c regulates hippocampal neurons ferroptosis to ameliorate perioperative neurocognitive disorders in aged male mice

The aim of this research is to investigate whether ferroptosis occurs in the pathogenesis of perioperative neurocognitive disorders (PND), and to explore the function and underlying molecular mechanism of tsRNA in the regulation of ferroptosis in PND. A PND aged mice model was established and behavioral changes and ferroptosis occurrence were confirmed. The effect of ferroptosis inhibitor ferrostatin-1 (Fer-1) on PND mice was detected. tsRNA expression profile in PND mice and the effect of tsRNA on ferroptosis in vitro were perfomed. We found that anxious exploration behavior and short-term working memory was declined in PND mice compared with control mice, and the levels of S100β and IL-6 were increased. Meanwhile, hippocampal neurons of PND mice were damaged and accompanied by ferroptosis. Fer-1 can improve cognitive impairment in PND mice, as reflected by improved anxious exploration behavior and short-term working memory, and the levels of S100β and IL-6 were decreased. The expression profile of tsRNA in PND mice is disordered, and the dysregulated tsRNAs were mainly enriched in biologic functions related to neuronal development and ferroptosis. The tsRNA-5006c, identified as a pivotal player, significantly suppressed ferroptosis in primary mice neurons. This study shows for the first time that the pathophysiological process of PND is accompanied by ferroptosis of neurons, and reveals that tsRNA-5006c regulates ferroptosis of hippocampal neurons to ameliorate PND, which is of great significance for the development of new treatment strategies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-04176-3.

Targeting protein-protein interactions in drug discovery: Modulators approved or in clinical trials for cancer treatment

Protein-protein interactions (PPIs) form complex cellular networks fundamental to many key biological processes, including signal transduction, cell proliferation and DNA repair. In consequence, their perturbation is often associated with many human diseases. Targeting PPIs offers a promising approach in drug discovery and ongoing advancements in this field hold the potential to provide highly specific therapies for a wide range of complex diseases. Despite the development of PPI modulators is challenging, advances in the genetic, proteomic and computational level have facilitated their discovery and optimization. Focusing on anticancer drugs, in the last years several PPI modulators have entered clinical trials and venetoclax, which targets Bcl-2 family proteins, has been approved for treating different types of leukemia. This review discusses the clinical development status of drugs modulating several PPIs, such as MDM2-4/p53, Hsp90/Hsp90, Hsp90/CDC37, c-Myc/Max, KRAS/SOS1, CCR5/CCL5, CCR2/CCL2 or Smac/XIAP, in cancer drug discovery.

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.

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.

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.

Screening and surveillance practices for Multiple Endocrine Neoplasia type 1-related Neuroendocrine Tumours in European Neuroendocrine Tumor Society Centers of Excellence (ENETS CoE)-An ENETS MEN1 task force questionnaire study

Multiple Endocrine Neoplasia type 1 (MEN1) Clinical Practice Guidelines (2012) are predominantly based on expert opinion due to limited available evidence at the time, leaving room for interpretation and variation in practices. Evidence on the natural course of MEN1-related neuroendocrine tumours (NET) and the value of screening programs has increased and new imaging techniques have emerged. The aim of this study is to provide insight in the current practices of screening and surveillance for MEN1-related NETs in ENETS Centers of Excellence (CoEs). A clinical practice questionnaire was distributed among all 65 ENETS CoEs. Response rate was 91% (59/65). In 14% of CoEs <10 patients, in 50% 10-49, in 31% 50-100 and in 3 centres (5%) >100 patients with MEN1 are seen. Practices with regard to screening and surveillance of NETs were markedly heterogeneous. Differences between countries were noted in the use of gut hormones for biochemical screening and the choice for imaging modality for screening/surveillance of pancreatic NETs (PanNETs). Magnetic resonance imaging (MRI) is the preferred modality for screening and surveillance of PanNETs, whereas this is computed tomography (CT) for thoracic NETs. Practices regarding screening for thoracic NETs were more homogeneous among larger volume CoEs, with longer screening intervals. The majority of CoEs tailored the surveillance of small pancreatic and lung NETs to observed growth rate. 68% of CoEs advise patients with clinical MEN1 with negative genetic testing to undergo periodic screening like mutation-positive patients. In conclusion, there is still marked heterogeneity in practice, although there are also common trends. Differences were sometimes associated with volume or country, but often no association was found. This underscores the need for clear and evidence-based practice recommendations.

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.

Wild-Type and rtA181T/sW172* Mutant Strains of Hepatitis B Virus Drive Hepatocarcinogenesis via Distinct GRP78-Mediated ER Stress Pathways

Glucose-regulated protein 78 kDa (GRP78), a key marker of endoplasmic reticulum stress (ERS), is upregulated in hepatocellular carcinoma (HCC) tissues, but its role in hepatitis B virus (HBV)-induced tumorigenesis remains unclear. This study aimed to investigate the contribution of GRP78 to HBV-associated tumor development and explore the ERS pathways involved. The results showed that increased GRP78 expression in patients with HBV-related HCC was associated with a poor prognosis within the first 2 years following diagnosis. Furthermore, using wild-type HBV strain and the oncogenic HBV rtA181T/sW172* mutant, this study demonstrated that the HBV-induced GRP78 expression correlated with elevated reactive oxygen species (ROS) levels. Moreover, GRP78 expression enhanced hepatocyte proliferation and resistance to apoptosis. In wild-type HBV-infected hepatocytes, GRP78 suppressed apoptosis by inhibiting the PERK/p38 pathway. In contrast, the HBV rtA181T/sW172* mutation led to increased GRP78 expression and inhibition of cell apoptosis through activation of the IRE-1α/XBP1/BCL-2 pathway. In conclusion, GRP78 plays a pivotal role in HBV-induced hepatocarcinogenesis by modulating distinct ERS pathways. Targeting these pathways may aid in the therapeutic management of HBV-associated hepatocarcinogenesis.

miRNA profile in pancreatic neuroendocrine tumors: Preliminary results

OBJECTIVE

Our understanding of the pathophysiology of pancreatic neuroendocrine tumors (PanNETs) remains incomplete, largely due to their historically underestimated incidence and the perception of these tumors as rare and slow-growing cancers. Additionally, conventional reliance on histological examination alone is gradually being supplemented by the exploration and introduction of molecular biomarkers, such as microRNAs (miRNAs). As miRNAs modulate the expression of multiple genes and pathways involved in the tumorigenesis of PanNETs, these biomarkers hold considerable promise for diagnosis and prognosis applications. In this study, we aimed to identify miRNAs as tissue markers associated with the diagnosis of PanNETs.

METHODS

We conducted a case-control study including: 7 PanNETs and 19 nontumoral pancreatic tissues obtained from Romanian patients. The samples underwent miRNA profiling via quantitative RT-PCR to assess the expression of 84 miRNAs. Our results were compared with those obtained by reanalyzing a public dataset. Furthermore, we structured our miRNA expression data according to their targeted mRNAs and their roles in signaling pathways.

RESULTS

Fourteen miRNAs (miR-1, miR-133a-3p, miR-210-3p, miR-7-5p, miR-10a-5p, miR-92b-3p, miR-132-3p, miR-221-3p, miR-29b-3p, miR-107, miR-103a-3p, let-7b-5p, miR-148a-3p, and miR-202-3p) were identified as differentially expressed by comparing PanNETs with pancreatic nontumoral tissues, with six miRNAs (miR-7-5p, miR-92b-3p, miR-29b-3p, miR-107, miR-103a-3p, and miR-148a-3p) also found in the public dataset analyzed. Bioinformatic analysis revealed that the 14 identified miRNAs target 17 genes. Reanalyzing two public gene expression datasets, five of these genes have been found differentially expressed in PanNET compared to controls.

CONCLUSIONS

Our preliminary results, albeit limited by a small sample size, highlighted a specific miRNA expression pattern able to distinguish tumoral from normal pancreatic tissue. The diagnostic performance of these miRNAs, matching with circulating miRNAs and validated in more homogeneous and large cohorts, could represent a starting point for improving the diagnostic accuracy of PanNETs.