PPARG-mediated autophagy activation alleviates inflammation in rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease characterized by joint inflammation and bone damage, that not only restricts patient activity but also tends to be accompanied by a series of complications, seriously affecting patient prognosis. Peroxisome proliferator-activated receptor gamma (PPARG), a receptor that controls cellular metabolism, regulates the function of immune cells and stromal cells. Previous studies have shown that PPARG is closely related to the regulation of inflammation. However, the role of PPARG in regulating the pathological processes of RA is poorly understood.

MATERIALS AND METHODS

PPARG expression was examined in the synovial tissues and peripheral blood mononuclear cells (PBMCs) from RA patients and the paw of collagen-induced arthritis (CIA) model rats. Molecular biology experiments were designed to examine the effect of PPARG and cannabidiol (CBD) on RAW264.7 cells and CIA rats.

RESULTS

The results reveal that PPARG accelerates reactive oxygen species (ROS) clearance by promoting autophagy, thereby inhibiting ROS-mediated macrophage polarization and NLRP3 inflammasome activation. Notably, CBD may be a promising candidate for understanding the mechanism by which PPARG regulates autophagy-mediated inflammation.

CONCLUSIONS

Taken together, these findings indicate that PPARG may have a role for distinguishing between RA patients and healthy control, and for distinguishing RA activity; moreover, PPARG could be a novel pharmacological target for alleviating RA through the mediation of autophagy. CBD can act as a PPARG agonist that alleviates the inflammatory progression of RA.

18β-Glycyrrhetinic acid protects against deoxynivalenol-induced liver injury via modulating ferritinophagy and mitochondrial quality control

Deoxynivalenol (DON), a widespread mycotoxin, represents a substantial public health hazard due to its propensity to contaminate agricultural produce, leading to both acute and chronic health issues in humans and animals upon consumption. The role of ferroptosis in DON-induced hepatic damage remains largely unexplored. This study investigates the impact of 18β-glycyrrhetinic acid (GA), a prominent constituent of glycyrrhiza, on DON hepatotoxicity and elucidates the underlying mechanisms. Our results indicate that GA effectively attenuates liver injury inflicted by DON. This was achieved by inhibiting nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy and ferroptosis, as well as by adjusting mitochondrial quality control (MQC). Specifically, GA curtails ferritinophagy by diminishing NCOA4 expression without affecting the autophagic flux. At a molecular level, GA binds to and stabilizes programmed cell death protein 4 (PDCD4), thereby inhibiting its ubiquitination and subsequent degradation. This stabilization of PDCD4 leads to the downregulation of NCOA4 via the JNK-Jun-NCOA4 axis. Knockdown of PDCD4 weakened GA's protective action against DON exposure. Furthermore, GA improved mitochondrial function and limited excessive mitophagy and mitochondrial division induced by DON. Disrupting GA's modulation of MQC nullified its anti-ferroptosis effects. Overall, GA offers protection against DON-induced ferroptosis by blocking ferritinophagy and managing MQC. ENVIRONMENTAL IMPLICATION: Food contamination from mycotoxins, is a problem for agricultural and food industries worldwide. Deoxynivalenol (DON), the most common mycotoxins in cereal commodities. A survey in 2023 showed that the positivity rate for DON contamination in food reached more than 70% globally. DON can damage the health of humans whether exposed to high doses for short periods of time or low doses for long periods of time. We have discovered 18β-Glycyrrhetinic acid (GA), a prominent constituent of glycyrrhiza. Liver damage caused by low-dose DON can be successfully treated with GA. This study will support the means of DON control, including antidotes.

Biochanin a ameliorates DSS-induced ulcerative colitis by improving colonic barrier function and protects against the development of spontaneous colitis in the Muc2 deficient mice

There is an increasing appreciation that colonic barrier function is closely related to the development and progression of colitis. The mucus layer is a crucial component of the colonic barrier, responsible for preventing harmful bacteria from invading the intestinal epithelium and causing inflammation. Furthermore, a defective mucus barrier is also a significant characteristic of ulcerative colitis (UC). Biochanin A (BCA), an isoflavonoid, has garnered increasing interest due to its significant biological activities. However, the impact of BCA on UC has not been reported yet. In this study, we used a dextran sodium sulfate (DSS)-induced ulcerative colitis model and the Muc2 deficient (Muc2-/-) mice spontaneous colitis model to explore the mechanisms of BCA in the treatment of UC. Here, we verified that DSS-induced UC was observably attenuated and spontaneous colitis in Muc2-/- mice was relieved by BCA. Treatment with BCA improved colitis-related symptoms and reduced intestinal permeability by upregulating the levels of goblet cells and tight junction (TJ) proteins. In addition, we confirmed that BCA promotes autophagy through the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) pathway, thereby alleviating DSS-induced UC. In addition, the administration of BCA was able to reduce apoptosis and promote proliferation by suppressing Cleaved Caspase-3 (Cleaved Cas-3) expression, and increasing PCNA and Ki67 levels. Further research revealed that BCA treatment ameliorated spontaneous colitis and alleviated epithelial damage in Muc2-/- mice by restoring the intestinal barrier and promoting autophagy. Our results demonstrated that BCA alleviated UC by enhancing intestinal barrier function and promoting autophagy. These findings indicate that BCA may be a novel treatment alternative for UC.

The association between oxidized low-density lipoprotein and cancer: An emerging targeted therapeutic approach?

Lipids play an important role in varying vital cellular processes including cell growth and division. Elevated levels of low-density lipoprotein (LDL) and oxidized-LDL (ox-LDL), and overexpression of the corresponding receptors including LDL receptor (LDLR), lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), and cluster of differentiation 36 (CD36), have shown strong correlations with different facets of carcinogenesis including proliferation, invasion, and angiogenesis. Furthermore, a high serum level of LOX-1 is considered as a poor prognostic factor in many types of cancer including colorectal cancer. Ox-LDL could contribute to cancer progression and metastasis through endothelial-to-mesenchymal transition (EMT) and autophagy. Thus, many studies have shed light on the significant role of ox-LDL as a potential therapeutic target for cancer therapy. In various repurposing approaches, anti-dyslipidemia agents, phytochemicals, autophagy modulators as well as recently developed ldl-like nanoparticles have been investigated as potential tumor therapeutic agents by targeting oxidized-LDL/LOX-1 pathways. Herein, we reviewed the role of oxidized-LDL and LOX-1 in cancer progression, invasion, metastasis, and also cancer-associated angiogenesis. Moreover, we addressed therapeutic utility of several compounds that proved to be capable of targeting the metabolic moieties in cancer. This review provides insights on the potential impact of targeting LDL and ox-LDL in cancer therapy and their future biomedical implementations.

Perfluoroalkyl sulfonate induces cardiomyocyte apoptosis via endoplasmic reticulum stress activation and autophagy flux inhibition

Perfluoroalkyl sulfonate (PFOS) is a commonly used chemical compound that often found in materials such as waterproofing agents, food packaging, and fire retardants. Known for its stability and persistence in the environment, PFOS can enter the human body through various pathways, including water and the food chain, raising concerns about its potential harm to human health. Previous studies have suggested a cardiac toxicity of PFOS, but the specific cellular mechanisms remained unclear. Here, by using AC16 cardiomyocyte as a model to investigate the molecular mechanisms potential the cardiac toxicity of PFOS. Our findings revealed that PFOS exposure reduced cell viability and induces apoptosis in human cardiomyocyte. Proteomic analysis and molecular biological techniques showed that the Endoplasmic Reticulum (ER) stress-related pathways were activated, while the cellular autophagy flux was inhibited in PFOS-exposed cells. Subsequently, we employed strategies such as autophagy activation and ER stress inhibition to alleviate the PFOS-induced apoptosis in AC16 cells. These results collectively suggest that PFOS-induced ER stress activation and autophagy flux inhibition contribute to cardiomyocyte apoptosis, providing new insights into the mechanisms of PFOS-induced cardiomyocyte toxicity.

Inhibition of miR-146b-5p alleviates isoprenaline-induced cardiac hypertrophy via regulating DFCP1

Pathological cardiac hypertrophy often precedes heart failure due to various stimuli, yet effective clinical interventions remain limited. Recently, microRNAs (miRNAs) have been identified as critical regulators of cardiovascular development. In this study, we investigated the role of miR-146b-5p and its underlying mechanisms of action in cardiac hypertrophy. Isoprenaline (ISO) treatment induced significant hypertrophy and markedly enhanced the expression of miR-146b-5p in cultured neonatal rat cardiomyocytes and hearts of C57BL/6 mice. Transfection with the miR-146b-5p mimic led to cardiomyocyte hypertrophy accompanied by autophagy inhibition. Conversely, miR-146b-5p inhibition significantly alleviated ISO-induced autophagy depression, thereby mitigating cardiac hypertrophy both in vitro and in vivo. Our results showed that the autophagy-related mediator double FYVE domain-containing protein 1 (DFCP1) is a target of miR-146b-5p. MiR-146b-5p blocked autophagic flux in cardiomyocytes by suppressing DFCP1, thus contributing to hypertrophy. These findings revealed that miR-146b-5p is a potential regulator of autophagy associated with the onset of cardiac hypertrophy, suggesting a possible therapeutic strategy involving the inhibition of miR-146b-5p.

6PPD induced cardiac dysfunction in zebrafish associated with mitochondrial damage and inhibition of autophagy processes

The compound 6PPD is widely acknowledged for its antioxidative properties; however, concerns regarding its impact on aquatic organisms have spurred comprehensive investigations. In our study, we advanced our comprehension by revealing that exposure to 6PPD could induce cardiac dysfunction, myocardial injury and DNA damage in adult zebrafish. Furthermore, our exploration unveiled that the exposure of cardiomyocytes to 6PPD resulted in apoptosis and mitochondrial injury, as corroborated by analyses using transmission electron microscopy and flow cytometry. Significantly, our study demonstrated the activation of the autophagy pathway in both the heart of zebrafish and cardiomyocytes, as substantiated by transmission electron microscopy and immunofluorescent techniques. Importantly, the increased the expression of P62 in the heart and cardiomyocytes suggested an inhibition of the autophagic process. The reduction in autophagy flux was also verified through in vivo experiments involving the infection of mCherry-GFP-LC3. We further identified that the fusion of autophagosomes and lysosomes was impaired in the 6PPD treatment group. In summary, our findings indicated that the impaired fusion of autophagosomes and lysosomes hampered the autophagic degradation process, leading to apoptosis and ultimately resulting in cardiac dysfunction and myocardial injury. This study discovered the crucial role of the autophagy pathway in regulating 6PPD-induced cardiotoxicity. SYNOPSIS: 6PPD exposure inhibited the autophagic degradation process and induced mitochondrial injury and apoptosis in the heart of adult zebrafish.

Dimorphic effect of TFE3 in determining mitochondrial and lysosomal content in muscle following denervation

BACKGROUND

Muscle atrophy is a common consequence of the loss of innervation and is accompanied by mitochondrial dysfunction. Mitophagy is the adaptive process through which damaged mitochondria are removed via the lysosomes, which are regulated in part by the transcription factor TFE3. The role of lysosomes and TFE3 are poorly understood in muscle atrophy, and the effect of biological sex is widely underreported.

METHODS

Wild-type (WT) mice, along with mice lacking TFE3 (KO), a transcriptional regulator of lysosomal and autophagy-related genes, were subjected to unilateral sciatic nerve denervation for up to 7 days, while the contralateral limb was sham-operated and served as an internal control. A subset of animals was treated with colchicine to capture mitophagy flux.

RESULTS

WT females exhibited elevated oxygen consumption rates during active respiratory states compared to males, however this was blunted in the absence of TFE3. Females exhibited higher mitophagy flux rates and greater lysosomal content basally compared to males that was independent of TFE3 expression. Following denervation, female mice exhibited less muscle atrophy compared to male counterparts. Intriguingly, this sex-dependent muscle sparing was lost in the absence of TFE3. Denervation resulted in 45% and 27% losses of mitochondrial content in WT and KO males respectively, however females were completely protected against this decline. Decreases in mitochondrial function were more severe in WT females compared to males following denervation, as ROS emission was 2.4-fold higher. In response to denervation, LC3-II mitophagy flux was reduced by 44% in females, likely contributing to the maintenance of mitochondrial content and elevated ROS emission, however this response was dysregulated in the absence of TFE3. While both males and females exhibited increased lysosomal content following denervation, this response was augmented in females in a TFE3-dependent manner.

CONCLUSIONS

Females have higher lysosomal content and mitophagy flux basally compared to males, likely contributing to the improved mitochondrial phenotype. Denervation-induced mitochondrial adaptations were sexually dimorphic, as females preferentially preserve content at the expense of function, while males display a tendency to maintain mitochondrial function. Our data illustrate that TFE3 is vital for the sex-dependent differences in mitochondrial function, and in determining the denervation-induced atrophy phenotype.

High glucose-induced p66Shc mitochondrial translocation regulates autophagy initiation and autophagosome formation in syncytiotrophoblast and extravillous trophoblast

BACKGROUND

p66Shc, as a redox enzyme, regulates reactive oxygen species (ROS) production in mitochondria and autophagy. However, the mechanisms by which p66Shc affects autophagosome formation are not fully understood.

METHODS

p66Shc expression and its location in the trophoblast cells were detected in vivo and in vitro. Small hairpin RNAs or CRISPR/Cas9, RNA sequencing, and confocal laser scanning microscope were used to clarify p66Shc's role in regulating autophagic flux and STING activation. In addition, p66Shc affects mitochondrial-associated endoplasmic reticulum membranes (MAMs) formation were observed by transmission electron microscopy (TEM). Mitochondrial function was evaluated by detected cytoplastic mitochondrial DNA (mtDNA) and mitochondrial membrane potential (MMP).

RESULTS

High glucose induces the expression and mitochondrial translocation of p66Shc, which promotes MAMs formation and stimulates PINK1-PRKN-mediated mitophagy. Moreover, mitochondrial localized p66Shc reduces MMP and triggers cytosolic mtDNA release, thus activates cGAS/STING signaling and ultimately leads to enhanced autophagy and cellular senescence. Specially, we found p66Shc is required for the interaction between STING and LC3II, as well as between STING and ATG5, thereby regulates cGAS/STING-mediated autophagy. We also identified hundreds of genes associated several biological processes including aging are co-regulated by p66Shc and ATG5, deletion either of which results in diminished cellular senescence.

CONCLUSION

p66Shc is not only implicated in the initiation of autophagy by promoting MAMs formation, but also helps stabilizing active autophagic flux by activating cGAS/STING pathway in trophoblast.

Sirt1 alleviates osteoarthritis via promoting FoxO1 nucleo-cytoplasm shuttling to facilitate autophagy

This study aims to investigate the role and underlying mechanisms of Sirt1 in the pathophysiological process of OA. Safranine O and HE staining were utilized to identify pathological changes in the cartilage tissue. Immunohistochemistry was employed to evaluate the expression levels of proteins. IL-1β treatment and TamCartSirt1flox/flox mice were utilized to induce OA model both in vitro and in vivo. Key autophagy-related transcription factors, autophagy-related genes, and chondrocyte extracellular matrix (ECM) breakdown enzyme markers were examined using multi assays. Immunofluorescence staining revealed subcellular localization and gene expression patterns. ChIP assay and Co-immunoprecipitation assay were conducted to investigate the interactions between FoxO1 and the promoter regions of Atg7 and Sirt1. Our results demonstrate that Sirt1 deficiency exhibited inhibitory effects on ECM synthesis and autophagy, as well as exacerbated angiogenesis. Moreover, Atg7, Foxo1, and Sirt1 could form a protein complex. Sirt1 was observed to facilitate nuclear translocation of FoxO1, enhancing its transcriptional activity. Furthermore, FoxO1 was found to bind to the promoter regions of Atg7 and Sirt1, potentially regulating their expression. This study provides valuable insights into the involvement of Sirt1-Atg7-FoxO1 loop in OA, opening new avenues for targeted therapeutic interventions aiming to mitigate cartilage degradation and restore joint function.

Interleukin-17 prevents oxidative stress from damaging osteoblast formation by inhibiting autophagic degradation of metallothionein-2

Interleukin 17A (IL-17A) is a key cytokine promoting osteoblast formation, which contributes to osteogenesis. IL-17A functions in autophagy inhibition within osteoblasts. Metallothionein-2 (MT-2), as an important reactive oxygen species (ROS)-scavenging molecule, prevents oxidative stress from damaging osteoblast formation. The relationship between IL-17A-regulated autophagy and MT-2 production under oxidative stress deserves further exploration. In this study, we first investigated the roles of IL-17A in osteoblastic differentiation and ROS production in osteoblast precursors in the presence of hydrogen peroxide (H2O2). Next, we explored the effects of IL-17A on autophagic activity and MT-2 protein expression in osteoblast precursors in the presence of H2O2. Ultimately, by using autophagic pharmacological agonist (rapamycin) and lentiviral transduction technology, the relationship between autophagy, IL-17A-regulated MT-2 protein expression and IL-17A-regulated ROS production was further elucidated. Our results showed that in the presence of H2O2, IL-17A promoted osteoblastic differentiation and inhibited ROS production. Moreover, in the presence of H2O2, IL-17A inhibited autophagic activity and promoted MT-2 protein expression in osteoblast precursors. Importantly, IL-17A-promoted MT-2 protein levels and -inhibited ROS production were reversed by autophagy activation with rapamycin. Furthermore, IL-17A-inhibited ROS production were blocked by MT-2 silencing. In conclusion, IL-17A promotes ROS clearance by inhibiting autophagic degradation of MT-2, thereby protecting osteoblast formation from oxidative stress.

LncRNA STARD7-AS1 suppresses cervical cancer cell proliferation while promoting autophagy by regulating miR-31-5p/TXNIP axis to inactivate the mTOR signaling

OBJECTIVE

Cervical cancer (CC) is a serious gynecologic health issue for women worldwide. Long non-coding RNA (lncRNA) has been well-documented in controlling malignant behavior of various cancer cells. The role of lncRNA STARD7-AS1 in regulating CC cell proliferation and autophagy and its possible mechanism were investigated in this work.

METHODS

RNA expression and protein levels were quantified by reverse transcription quantitative polymerase chain reaction and western blotting. The location of STARD7-AS1 in CC cells was examined using subcellular fraction assays. Cell Counting Kit-8 assays and colony forming assays were performed to measure CC cell viability and proliferation. Autophagy in CC cells was evaluated using macrophage-derived chemokine (MDC) staining and transmission electron microscopy. The binding between microRNA (miR)-31-5p and STARD7-AS1 (or thioredoxin-interacting protein [TXNIP]) was determined by performing luciferase reporter, RNA pull-down or RNA immunoprecipitation assays.

RESULTS

STARD7-AS1 overexpression significantly suppressed CC cell viability and proliferation while notably inducing autophagy. STARD7-AS1 upregulated TXNIP expression via interaction with miR-31-5p. In addition, the effects of STARD7-AS1 on CC cell proliferation and autophagy were reversed by TXNIP silencing. The suppressive effect of STARD7-AS1 overexpression on phosphorylated levels of mTOR and S6K1 was countervailed by TXNIP deficiency.

CONCLUSION

In conclusion, lncRNA STARD7-AS1 inhibits CC cell proliferation and promotes cell autophagy by targeting the miR-31-5p/TXNIP axis to inactivate the mTOR signaling.

AMPK/autophagy-mediated alleviation of tendinopathy by IL-38: A novel strategy for the treatment of obesity-related tendinopathy

The effect of interleukin-38 (IL-38), a recently identified member of the IL-1 family with potential applications in various inflammation-related conditions, on ER stress has not been explored. Furthermore, its role in obesity-associated tendinopathy has not been investigated. In this study, human primary tenocytes were treated with palmitate (200 or 400 μM) and palmitate plus IL-38 (0-50 ng/mL) for 24 h. Western blotting was used to assess ER stress and tendinopathogenic markers in tenocytes. Monodansylcadaverine (MDC) staining was used to evaluate autophagosomes. Apoptosis was determined by cell viability assays, caspase 3 activity assays and TUNEL assays. Cell migration was evaluated by a cell scratch assay. Small interfering (si) RNA transfection was used for target gene silencing. Treatment of tenocytes with IL-38 attenuated apoptosis, restored the balance between MMPs and TIMP-1, and alleviated ER stress under palmitate conditions. IL-38 treatment enhanced AMPK phosphorylation and promoted the expression of autophagy markers related to LC3 conversion, p62 degradation, and autophagosome formation in cultured tenocytes. The effects of IL-38 on ER stress, apoptosis, and MMP-9, MMP-13, and TIMP-1 expression in palmitate-treated tenocytes were abrogated by AMPK siRNA or 3-methyladenine (3MA). These results suggest that IL-38 alleviates ER stress through the AMPK/autophagy pathway, thereby reducing apoptosis and preventing extracellular matrix (ECM) degradation in tenocytes under hyperlipidemic conditions. This study provides a promising therapeutic avenue for treating obesity-related tendinopathy using an endogenous compound such as IL-38.

LncRNA MIR210HG promotes phenotype switching of pulmonary arterial smooth muscle cells through autophagy-dependent ferroptosis pathway

Hypoxic pulmonary hypertension (HPH) is a pathophysiological syndrome in which pulmonary vascular pressure increases under hypoxic stimulation and there is an urgent need to develop emerging therapies for the treatment of HPH. LncRNA MIR210HG is a long non-coding RNA closely related to hypoxia and has been widely reported in a variety of tumor diseases. But its mechanism in hypoxic pulmonary hypertension is not clear. In this study, we identified for the first time the potential effect of MIR210HG on disease progression in HPH. Furthermore, we investigated the underlying mechanism through which elevated levels of MIR210HG promotes the transition from a contractile phenotype to a synthetic phenotype in PASMCs under hypoxia via activation of autophagy-dependent ferroptosis pathway. While overexpression of HIF-2α in PASMCs under hypoxia significantly reversed the phenotypic changes induced by MIR210HG knockdown. We further investigated the potential positive regulatory relationship between STAT3 and the transcription of MIR210HG in PASMCs under hypoxic conditions. In addition, we established both in vivo and in vitro models of HPH to validate the differential expression of specific markers associated with hypoxia. Our findings suggest a potential mechanism of LncRNA MIR210HG in the progression of HPH and offer potential targets for disease intervention and treatment.

ADNP dysregulates methylation and mitochondrial gene expression in the cerebellum of a Helsmoortel-Van der Aa syndrome autopsy case

BACKGROUND

Helsmoortel-Van der Aa syndrome is a neurodevelopmental disorder in which patients present with autism, intellectual disability, and frequent extra-neurological features such as feeding and gastrointestinal problems, visual impairments, and cardiac abnormalities. All patients exhibit heterozygous de novo nonsense or frameshift stop mutations in the Activity-Dependent Neuroprotective Protein (ADNP) gene, accounting for a prevalence of 0.2% of all autism cases worldwide. ADNP fulfills an essential chromatin remodeling function during brain development. In this study, we investigated the cerebellum of a died 6-year-old male patient with the c.1676dupA/p.His559Glnfs*3 ADNP mutation.

RESULTS

The clinical presentation of the patient was representative of the Helsmoortel-Van der Aa syndrome. During his lifespan, he underwent two liver transplantations after which the child died because of multiple organ failure. An autopsy was performed, and various tissue samples were taken for further analysis. We performed a molecular characterization of the cerebellum, a brain region involved in motor coordination, known for its highest ADNP expression and compared it to an age-matched control subject. Importantly, epigenome-wide analysis of the ADNP cerebellum identified CpG methylation differences and expression of multiple pathways causing neurodevelopmental delay. Interestingly, transcription factor motif enrichment analysis of differentially methylated genes showed that the ADNP binding motif was the most significantly enriched. RNA sequencing of the autopsy brain further identified downregulation of the WNT signaling pathway and autophagy defects as possible causes of neurodevelopmental delay. Ultimately, label-free quantification mass spectrometry identified differentially expressed proteins involved in mitochondrial stress and sirtuin signaling pathways amongst others. Protein-protein interaction analysis further revealed a network including chromatin remodelers (ADNP, SMARCC2, HDAC2 and YY1), autophagy-related proteins (LAMP1, BECN1 and LC3) as well as a key histone deacetylating enzyme SIRT1, involved in mitochondrial energy metabolism. The protein interaction of ADNP with SIRT1 was further biochemically validated through the microtubule-end binding proteins EB1/EB3 by direct co-immunoprecipitation in mouse cerebellum, suggesting important mito-epigenetic crosstalk between chromatin remodeling and mitochondrial energy metabolism linked to autophagy stress responses. This is further supported by mitochondrial activity assays and stainings in patient-derived fibroblasts which suggest mitochondrial dysfunctions in the ADNP deficient human brain.

CONCLUSION

This study forms the baseline clinical and molecular characterization of an ADNP autopsy cerebellum, providing novel insights in the disease mechanisms of the Helsmoortel-Van der Aa syndrome. By combining multi-omic and biochemical approaches, we identified a novel SIRT1-EB1/EB3-ADNP protein complex which may contribute to autophagic flux alterations and impaired mitochondrial metabolism in the Helsmoortel-Van der Aa syndrome and holds promise as a new therapeutic target.

Aurora kinase A inhibition plus Tumor Treating Fields suppress glioma cell proliferation in a cilium-independent manner

Tumor Treating Fields (TTFields) extend the survival of glioblastoma (GBM) patients by interfering with a broad range of tumor cellular processes. Among these, TTFields disrupt primary cilia stability on GBM cells. Here we asked if concomitant treatment of TTFields with other agents that interfere with GBM ciliogenesis further suppress GBM cell proliferation in vitro. Aurora kinase A (AURKA) promotes both cilia disassembly and GBM growth. Inhibitors of AURKA, such as Alisertib, inhibit cilia disassembly and increase ciliary frequency in various cell types. However, we found that Alisertib treatment significantly reduced GBM cilia frequency in gliomaspheres across multiple patient derived cell lines, and in patient biopsies treated ex vivo. This effect appeared glioma cell-specific as it did not reduce normal neuronal or glial cilia frequencies. Alisertib-mediated depletion of glioma cilia appears specific to AURKA and not AURKB inhibition, and attributable in part to autophagy pathway activation. Treatment of two different GBM patient-derived cell lines with TTFields and Alisertib resulted in a significant reduction in cell proliferation compared to either treatment alone. However, this effect was not cilia-dependent as the combined treatment reduced proliferation in cilia-depleted cell lines lacking, ARL13B, or U87MG cells which are naturally devoid of ARL13B+ cilia. Thus, Alisertib-mediated effects on glioma cilia may be a useful biomarker of drug efficacy within tumor tissue. Considering Alisertib can cross the blood brain barrier and inhibit intracranial growth, our data warrant future studies to explore whether concomitant Alisertib and TTFields exposure prolongs survival of brain tumor-bearing animals in vivo.

LncRNA NEAT1 promotes MPP+ induced injury of PC12 cells and accelerates the progression of Parkinson's disease in mice through FUS mediated inhibition of PI3K/AKT/mTOR signalling pathway

Long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) is involved in the progression of Parkinson's disease (PD), but the specific regulatory role needs further exploration. This study showed that the expression of NEAT1 was upregulated in the cerebrospinal fluid (CSF) and peripheral blood of patients with different stages of PD. 1-Methyl-4-phenylpyridine (MPP)-treated PC 12 cells were transfected with si-NEAT1, and MPP treatment promoted cell apoptosis, oxidative stress and inflammatory factor secretion. Si-NEAT1 reversed the effects of MPP. NEAT1 silencing eliminated the effect of MPP on the protein expression levels of LC3-II and p62/SQSTM1. By using an online bioinformatics database, Fused in Sarcoma (FUS) was confirmed to be an RNA binding protein of NEAT1, and it was highly expressed in the CSF and peripheral blood of patients with PD. Si-FUS was transfected into MPP-treated PC 12 cells to detect cell apoptosis, oxidative stress, inflammatory factor secretion and autophagy, and the results were the same as those of transfection of si-NEAT1. Furthermore, MPP treatment reduced the phosphorylation levels of PI3K, Akt and mTOR, whereas si-FUS reversed the effects of MPP. In vivo, compared with the model group, the PD mice showed reduced NEAT1 and FUS expression levels and activated PI3K pathway after being injected with si-NEAT1. The brain tissue of NEAT1-silenced PD mice had decreased inflammatory infiltration and apoptosis and increased neurological scores. In conclusion, NEAT1 is involved in PD progression through FUS-mediated inhibition of the PI3K/AKT/mTOR signalling pathway.

Exercise promotes osteogenic differentiation by activating the long non-coding RNA H19/microRNA-149 axis

BACKGROUND

Regular physical activity during childhood and adolescence is beneficial to bone development, as evidenced by the ability to increase bone density and peak bone mass by promoting bone formation.

AIM

To investigate the effects of exercise on bone formation in growing mice and to investigate the underlying mechanisms.

METHODS

20 growing mice were randomly divided into two groups: Con group (control group, n = 10) and Ex group (treadmill exercise group, n = 10). Hematoxylin-eosin staining, immunohistochemistry, and micro-CT scanning were used to assess the bone formation-related indexes of the mouse femur. Bioinformatics analysis was used to find potential miRNAs targets of long non-coding RNA H19 (lncRNA H19). RT-qPCR and Western Blot were used to confirm potential miRNA target genes of lncRNA H19 and the role of lncRNA H19 in promoting osteogenic differentiation.

RESULTS

Compared with the Con group, the expression of bone morphogenetic protein 2 was also significantly increased. The micro-CT results showed that 8 wk moderate-intensity treadmill exercise significantly increased bone mineral density, bone volume fraction, and the number of trabeculae, and decreased trabecular segregation in the femur of mice. Inhibition of lncRNA H19 significantly upregulated the expression of miR-149 and suppressed the expression of markers of osteogenic differentiation. In addition, knockdown of lncRNA H19 significantly downregulated the expression of autophagy markers, which is consistent with the results of autophagy-related protein changes detected in mouse femurs by immunofluorescence.

CONCLUSION

Appropriate treadmill exercise can effectively stimulate bone formation and promote the increase of bone density and bone volume in growing mice, thus enhancing the peak bone mass of mice. The lncRNA H19/miR-149 axis plays an important regulatory role in osteogenic differentiation.

OPA1 mutation affects autophagy and triggers senescence in autosomal dominant optic atrophy plus fibroblasts

In several cases of mitochondrial diseases, the underlying genetic and bioenergetic causes of reduced oxidative phosphorylation (OxPhos) in mitochondrial dysfunction are well understood. However, there is still limited knowledge about the specific cellular outcomes and factors involved for each gene and mutation, which contributes to the lack of effective treatments for these disorders. This study focused on fibroblasts from a patient with Autosomal Dominant Optic Atrophy (ADOA) plus syndrome harboring a mutation in the Optic Atrophy 1 (OPA1) gene. By combining functional and transcriptomic approaches, we investigated the mitochondrial function and identified cellular phenotypes associated with the disease. Our findings revealed that fibroblasts with the OPA1 mutation exhibited a disrupted mitochondrial network and function, leading to altered mitochondrial dynamics and reduced autophagic response. Additionally, we observed a premature senescence phenotype in these cells, suggesting a previously unexplored role of the OPA1 gene in inducing senescence in ADOA plus patients. This study provides novel insights into the mechanisms underlying mitochondrial dysfunction in ADOA plus and highlights the potential importance of senescence in disease progression.

Toxic gain-of-function mechanisms in C9orf72 ALS-FTD neurons drive autophagy and lysosome dysfunction

Hexanucleotide repeat expansions in the C9orf72 gene are the primary genetic cause for both amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two related neurodegenerative diseases. Significant advances in the elucidation of the disease mechanisms responsible for C9orf72 ALS-FTD have revealed both a toxic gain-of-function and a loss-of-function mechanism as possible underlying disease cause. As the differential contribution of both gain and loss of function in C9orf72 ALS-FTD pathogenesis remains debated, we investigated disease mechanisms in motor neurons derived from both authentic human patient C9orf72 ALS-FTD iPSCs as well as a C9orf72 knockout iPSC line. We found that patient neurons presented with less motile and enlarged lysosomes, a decrease in autophagic flux and an increase in SQSTM1/p62 puncta and insoluble TARDBP/TDP-43 species. Importantly, we found that C9orf72 knockout barely has any influence on these phenotypes and mainly results in impaired endosomal maturation. Together, our data suggest that toxic gain-of-function, rather than loss-of-function, mechanisms in C9orf72 ALS-FTD impair the autophagy-lysosome system in neurons.

FoxG1 as a Potential Therapeutic Target for Alzheimer's Disease: Modulating NLRP3 Inflammasome via AMPK/mTOR Autophagy Pathway

An increasing body of research suggests that promoting microglial autophagy hinders the neuroinflammation initiated though the NLRP3 inflammasome activation in Alzheimer's disease (AD). The function of FoxG1, a crucial transcription factor involved in cell survival by regulating mitochondrial function, remains unknown during the AD process and neuroinflammation occurs. In the present study, we firstly found that Aβ peptides induced AD-like neuroinflammation upregulation and downregulated the level of autophagy. Following low-dose Aβ25-35 stimulation, FoxG1 expression and autophagy exhibited a gradual increase. Nevertheless, with high-concentration Aβ25-35 treatment, progressive decrease in FoxG1 expression and autophagy levels as the concentration of Aβ25-35 escalated. In addition, FoxG1 has a positive effect on cell viability and autophagy in the nervous system. In parallel with the Aβ25-35 stimulation, we employed siRNA to decrease the expression of FoxG1 in N2A cells. A substantial reduction in autophagy level (Beclin1, LC3II, SQSTM1/P62) and a notable growth in inflammatory response (NLRP3, TNF-α, and IL-6) were observed. In addition, we found FoxG1 overexpression owned the effect on the activation of AMPK/mTOR autophagy pathway and siRNA-FoxG1 successfully abolished this effect. Lastly, FoxG1 suppressed the NLRP3 inflammasome and enhanced the cognitive function in AD-like mouse model induced by Aβ25-35. Confirmed by cellular and animal experiments, FoxG1 suppressed NLRP3-mediated neuroinflammation, which was strongly linked to autophagy regulated by AMPK/mTOR. Taken together, FoxG1 may be a critical node in the pathologic progression of AD and has the potential to serve as therapeutic target.

The Multifaceted Role of Intracellular Glycosylation in Cytoprotection and Heart Disease

The modification of nuclear, cytoplasmic, and mitochondrial proteins by O-linked β-N-acetylglucosamine (O-GlcNAc) is an essential post-translational modification common in metazoans. O-GlcNAc is cycled on and off proteins in response to environmental and physiological stimuli impacting protein function, which, in turn, tunes pathways that include transcription, translation, proteostasis, signal transduction, and metabolism. One class of stimulus that induces rapid and dynamic changes to O-GlcNAc is cellular injury, resulting from environmental stress (for instance, heat shock), hypoxia/reoxygenation injury, ischemia reperfusion injury (heart attack, stroke, trauma hemorrhage), and sepsis. Acute elevation of O-GlcNAc before or after injury reduces apoptosis and necrosis, suggesting that injury-induced changes in O-GlcNAcylation regulate cell fate decisions. However, prolonged elevation or reduction in O-GlcNAc leads to a maladaptive response and is associated with pathologies such as hypertrophy and heart failure. In this review, we discuss the impact of O-GlcNAc in both acute and prolonged models of injury with a focus on the heart and biological mechanisms that underpin cell survival.

Phloridzin reduces synovial hyperplasia and inflammation in rheumatoid arthritis rat by modulating mTOR pathway

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease and management of it still a challenge. Given report evaluates protective effect of phlorizin on RA and also postulates the molecular mechanism of its action. Bovine type II collagen (CIA) and Freund's incomplete adjuvant (1:1 and 1 mg/ml) was administered on 1st and 8th day of protocol to induce RA in rats and treatment with phlorizin 60 and 120 mg/kg was started after 4th week of protocol. Level of inflammatory cytokines and expression of proteins were estimated in phlorizin treated RA rats. Moreover in-vitro study was performed on Fibroblast-like synoviocytes (FLSs) and effect of phlorizin was estimated on proliferation, apoptosis and expression of mTOR pathway protein after stimulating these cell lines with Tumour Necrosis Factor alpha (TNF-α). Data of study suggest that phlorizin reduces inflammation and improves weight in CIA induced RA rats. Level of inflammatory cytokines in the serum and expression of Akt/PI3K/mTOR proteins in the join tissue was reduced in phlorizin treated RA rats. Phlorizin also reported to reverse the histopathological changes in the joint tissue of RA rats. In-vitro study supports that phlorizin reduces proliferation and no apoptotic effect on TNF-α stimulated FLSs. Expression of Akt/PI3K/mTOR proteins also downregulated in phlorizin treated TNF-α stimulated FLSs. In conclusion, phlorizin protects inflammation and reduces injury to the synovial tissues in RA, as it reduces autophagy by regulating Akt/PI3K/mTOR pathway.

Liver cancer wars: plant-derived polyphenols strike back

Liver cancer currently represents the leading cause of cancer-related death worldwide. The majority of liver cancer arises in the context of chronic inflammation and cirrhosis. Surgery, radiation therapy, and chemotherapy have been the guideline-recommended treatment options for decades. Despite enormous advances in the field of liver cancer therapy, an effective cure is yet to be found. Plant-derived polyphenols constitute a large family of phytochemicals, with pleiotropic effects and little toxicity. They can drive cellular events and modify multiple signaling pathways which involves initiation, progression and metastasis of liver cancer and play an important role in contributing to anti-liver cancer drug development. The potential of plant-derived polyphenols for treating liver cancer has gained attention from research clinicians and pharmaceutical scientists worldwide in the last decades. This review overviews hepatic carcinogenesis and briefly discusses anti-liver cancer mechanisms associated with plant-derived polyphenols, specifically involving cell proliferation, apoptosis, autophagy, angiogenesis, oxidative stress, inflammation, and metastasis. We focus on plant-derived polyphenols with experiment-based chemopreventive and chemotherapeutic properties against liver cancer and generalize their basic molecular mechanisms of action. We also discuss potential opportunities and challenges in translating plant-derived polyphenols from preclinical success into clinical applications.

Fangji Huangqi Decoction alleviates rheumatoid arthritis through regulating HIF-1α mediated the angiogenesis and the balance between autophagy and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Fangji Huangqi Decoction (FHD) is frequently prescribed for the clinical treatment of wind-cold and wind-dampness pathogenic superficial deficiency syndrome. It also has a notable curative effect on rheumatoid arthritis (RA).

AIM OF THE STUDY

The study aimed to explore the possible mechanism of FHD against RA and provided a theoretical basis for alternative therapies for RA.

MATERIALS AND METHODS

We used UPLC-Q-TOF-MS to analysis the ingredients and absorbed blood components of FHD. At the same time, the collagen-induced arthritis (CIA) rat model was established to estimate the therapeutic effects on FHD by considering body weight, arthritis score, paw swelling, autonomous movement ability, and synovial microvessel counts. Subsequently, immunofluorescence, immunohistochemistry, and Western blot were employed to detect the anti-angiogenic capacity of FHD in vivo, as well as the levels of apoptosis and autophagy in the synovial tissue. In addition, flow cytometry and Western blot were used to assess the effects of FHD on apoptosis and autophagy in MH7A cells. The effects of FHD on the proliferation and migration of MH7A cells were measured by CCK8 assay, cell migration and, invasion experiments. Finally, a tube formation assay was performed to evaluate the angiogenic capacity of FHD in co-cultures of MH7A cells and HUVEC cells.

RESULTS

Through testing of FHD's original formula, a total of 26 active ingredients have been identified, with 17 of them being absorbed into the bloodstream. FHD significantly improved the pathological symptoms and synovial hyperplasia of CIA rats. FHD could suppress the expression of HIF-1α, promote apoptosis in CIA rat synovial tissue, and suppress autophagy and angiogenesis. In vitro experiments showed that serum containing FHD inhibited the proliferation, migration, and invasion of MH7A cells, and also suppressed the expression of autophagy-related proteins while promoting apoptosis. FHD markedly repressed the expression of HIF-1α protein in TNF-α-stimulated MH7A cells and inhibited the tube formation capacity induced by MH7A cells in HUVEC cells.

CONCLUSIONS

The study had proven that FHD played an excellent anti-RA role, which may be attributed to its potential mechanism of regulating the balance between autophagy and apoptosis in RA FLS by suppressing the HIF-1α, thus contributing to its anti-angiogenic activities.

The involvement of ROS-regulated programmed cell death in hepatocellular carcinoma

Reactive oxidative species (ROS) is a crucial factor in the regulation of cellular biological activity and function, and aberrant levels of ROS can contribute to the development of a variety of diseases, particularly cancer. Numerous discoveries have affirmed that this process is strongly associated with "programmed cell death (PCD)," which refers to the suicide protection mechanism initiated by cells in response to external stimuli, such as apoptosis, autophagy, ferroptosis, etc. Research has demonstrated that ROS-induced PCD is crucial for the development of hepatocellular carcinoma (HCC). These activities serve a dual function in both facilitating and inhibiting cancer, suggesting the existence of a delicate balance within healthy cells that can be disrupted by the abnormal generation of reactive oxygen species (ROS), thereby influencing the eventual advancement or regression of a tumor. In this review, we summarize how ROS regulates PCD to influence the tumorigenesis and progression of HCC. Studying how ROS-induced PCD affects the progression of HCC at a molecular level can help develop better prevention and treatment methods and facilitate the design of more effective preventative and therapeutic strategies.

A phosphodiesterase 4 (PDE4) inhibitor, amlexanox, reduces neuroinflammation and neuronal death after pilocarpine-induced seizure

Epilepsy, a complex neurological disorder, is characterized by recurrent seizures caused by aberrant electrical activity in the brain. Central to this study is the role of lysosomal dysfunction in epilepsy, which can lead to the accumulation of toxic substrates and impaired autophagy in neurons. Our focus is on phosphodiesterase-4 (PDE4), an enzyme that plays a crucial role in regulating intracellular cyclic adenosine monophosphate (cAMP) levels by converting it into adenosine monophosphate (AMP). In pathological states, including epilepsy, increased PDE4 activity contributes to a decrease in cAMP levels, which may exacerbate neuroinflammatory responses. We hypothesized that amlexanox, an anti-inflammatory drug and non-selective PDE4 inhibitor, could offer neuroprotection by addressing lysosomal dysfunction and mitigating neuroinflammation, ultimately preventing neuronal death in epileptic conditions. Our research utilized a pilocarpine-induced epilepsy animal model to investigate amlexanox's potential benefits. Administered intraperitoneally at a dose of 100 ​mg/kg daily following the onset of a seizure, we monitored its effects on lysosomal function, inflammation, neuronal death, and cognitive performance in the brain. Tissue samples from various brain regions were collected at predetermined intervals for a comprehensive analysis. The study's results were significant. Amlexanox effectively improved lysosomal function, which we attribute to the modulation of zinc's influx into the lysosomes, subsequently enhancing autophagic processes and decreasing the release of inflammatory factors. Notably, this led to the attenuation of neuronal death in the hippocampal region. Additionally, cognitive function, assessed through the modified neurological severity score (mNSS) and the Barnes maze test, showed substantial improvements after treatment with amlexanox. These promising outcomes indicate that amlexanox has potential as a therapeutic agent in the treatment of epilepsy and related brain disorders. Its ability to combat lysosomal dysfunction and neuroinflammation positions it as a potential neuroprotective intervention. While these findings are encouraging, further research and clinical trials are essential to fully explore and validate the therapeutic efficacy of amlexanox in epilepsy management.

Emodin activates autophagy to suppress oxidative stress and pyroptosis via mTOR-ULK1 signaling pathway and promotes multi-territory perforator flap survival

BACKGROUND

Multi-territory perforator flap reconstruction has been proven effective in treating large skin and soft tissue defects in clinical settings. However, in view of that the multi-territory perforator flap is prone to partial postoperative necrosis, increasing its survival is the key to the success of reconstruction. In this study, we aimed to clarify the effect of emodin on multi-territory perforator flap survival.

METHODS

Flap survival was assessed by viability area analysis, infrared laser imaging detector, HE staining, immunohistochemistry, and angiography. Western blotting, immunofluorescence assays, and real-time fluorescent quantitative PCR were performed to detect the indicators of oxidative stress, pyroptosis and autophagy.

RESULTS

After emodin treatment, the multi-territory perforator flap showed a significantly increased survival rate, which was shown to be closely related to the inhibition of oxidative stress and pyroptosis and enhanced autophagy. Meanwhile, the use of autophagy inhibitor 3 MA was found to reverse the inhibitory effects of emodin on oxidative stress and pyroptosis and weaken the improving effect of emodin on flap survival, suggesting that autophagy plays a critical role in emodin-treated flaps. Interestingly, our mechanistic investigations revealed that the positive effect of emodin on multi-territory perforator flap was attributed to the mTOR-ULK1 signaling pathway activation.

CONCLUSIONS

Emodin can inhibit oxidative stress and pyroptosis by activating autophagy via the mTOR-ULK1 pathway, thereby improving the multi-territory perforator flap survival.

CCAAT enhancer binding protein delta activates vesicle associated membrane protein 3 transcription to enhance chemoresistance and extracellular PD-L1 expression in triple-negative breast cancer

BACKGROUND

Chemoresistance and immunosuppression are two major obstacles in the current anti-cancer treatments. This study investigates the involvements of a CCAAT enhancer binding protein delta (CEBPD)/vesicle associated membrane protein 3 (VAMP3) axis in paclitaxel (PTX) resistance and immune evasion in triple-negative breast cancer (TNBC).

METHODS

PTX resistance-related genes were screened by bioinformatics. CEBPD and VAMP3 expression in clinical TNBC samples was examined by immunohistochemistry. Three PTX-resistant TNBC cell lines (MDA-MB-231/PTX, MDA-MB-468/PTX and MDA-MB-453/PTX) were generated, and their drug resistance was analyzed. Autophagy of cells was analyzed by immunofluorescence staining. Interaction between CEBPD and VAMP3 promoter was identified by immunoprecipitation and luciferase assays. The extracellular expression of programmed cell death-ligand 1 (PD-L1) in TNBC cells was detected. Extracellular vesicles (EVs) from TNBC cells were isolated to examine their effects on CD8+ T cell exhaustion.

RESULTS

CEBPD and VAMP3 were upregulated in chemo-resistant tissue samples and in PTX-resistant TNBC cells. The CEBPD downregulation enhanced PTX sensitivity of cells. However, further upregulation of VAMP3 in cells restored PTX resistance, which was likely due to the activation of autophagy, as the autophagy antagonist chloroquine enhanced PTX sensitivity of cells. CEBPD was found to bind to the VAMP3 promoter to activate its transcription. The CEBPD/VAMP3 axis also increased the PD-L1 expression in the conditioned medium of TNBC cells. The TNBC cell-derived EVs increased the exhaustion of co-cultured CD8+ T cells.

CONCLUSION

This study provides novel evidence that CEBPD plays a key role in enhancing PTX resistance in TNBC cells across various subtypes through VAMP3-mediated autophagy activation. Additionally, the CEBPD/VAMP3 axis also increases extracellular PD-L1 level, delivered by cancer cell-derived EVs, to suppress CD8+ T cell-mediated anti-tumor immune response. These significant observations may provide new insights into the treatment of TNBC, suggesting CEBPD and VAMP3 as promising targets to overcome treatment resistance.

Targeting peptide based therapeutics: Integrated computational and experimental studies of autophagic regulation in host-parasite interaction

Cutaneous leishmaniasis caused by the intracellular parasite Leishmania major, exhibits significant public health challenge worldwide. With limited treatment options available, the identification of novel therapeutic targets is of paramount importance. Present study manifested the crucial role of ATG8 protein as a potential target in combating L. major infection. Using machine learning algorithms, we identified non-conserved motifs within the ATG8 in L. major. Subsequently, a peptide library was generated based on these motifs, and three peptides were selected for further investigation through molecular docking and molecular dynamics simulations. Surface Plasmon Resonance (SPR) experiments confirmed the direct interaction between ATG8 and the identified peptides. Remarkably, these peptides demonstrated the ability to cross the parasite membrane and exert profound effects on L. major. Peptide treatment significantly impacted parasite survival, inducing alterations in the cell cycle and morphology. Furthermore, the peptides were found to modulate autophagosome formation, particularly under starved conditions, indicating their involvement in autophagy regulation within L. major. In vitro studies revealed that the selected peptides effectively decreased the parasite load within the infected host cells. Encouragingly, in vivo experiments corroborated these findings, demonstrating a reduction in parasite burden upon peptide administration. Additionally, the peptides were observed to affect the levels of LC3II, a known autophagy marker within the host cells. Collectively, our findings highlight the efficacy of these novel peptides in targeting L. major ATG8 and disrupting parasite survival, wherein P2 is showing prominent effect on L. major as compared to P1. These results provide valuable insights into the development of innovative therapeutic strategies against leishmaniasis.

Heme oxygenase activates calcium release from the endoplasmic reticulum of bovine mammary epithelial cells to promote TFEB entry into the nucleus to reduce the intracellular load of Mycoplasma bovis

Heme oxygenase HO-1 (HMOX) regulates cellular inflammation and apoptosis, but its role in regulation of autophagy in Mycoplasma bovis infection is unknown. The objective was to determine how the HO-1/CO- Protein kinase RNA-like endoplasmic reticulum kinase (PERK)-Ca2+- transcription factor EB (TFEB) signaling axis induces autophagy and regulates clearance of M. bovis by bovine mammary epithelial cells (bMECs). M. bovis inhibited autophagy and lysosomal biogenesis in bMECs and suppressed HO-1 protein and expression of related proteins, namely nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (keap1). Activation of HO-1 and its production of carbon monoxide (CO) were required for induction of autophagy and clearance of intracellular M. bovis. Furthermore, when HO-1 was deficient, CO sustained cellular autophagy. HO-1 activation increased intracellular calcium (Ca2+) and cytosolic localization activity of TFEB via PERK. Knockdown of PERK or chelation of intracellular Ca2+ inhibited HO-1-induced M. bovis autophagy and clearance. M. bovis infection affected nuclear localization of lysosomal TFEB in the MiT/TFE transcription factor subfamily, whereas activation of HO-1 mediated dephosphorylation and intranuclear localization of TFEB, promoting autophagy, lysosomal biogenesis and autophagic clearance of M. bovis. Nuclear translocation of TFEB in HO-1 was critical to induce M. bovis transport and survival of infected bMECs. Furthermore, the HO-1/CO-PERK-Ca2+-TFEB signaling axis induced autophagy and M. bovis clearance, providing a viable approach to treat persistent M. bovis infections.

Stanniocalcin 2 regulates autophagy and ferroptosis in mammary epithelial cells of dairy cows through the mTORC1 pathway

BACKGROUND

Stanniocalcin 2 (STC2), a glycoprotein hormone, is extensively expressed in various organs and tissues, particularly in the mammary gland. STC2 plays a crucial role in enabling cells to adapt to stress conditions and avert apoptosis. The efficiency of milk production is closely linked to both the quantity and quality of mammary cells. Yet there remains a dearth of research on the impact of STC2 on mammary cells activity in dairy cows.

OBJECTIVE

The objective of this study was to investigate the effects of STC2 on the viability of mammary epithelial cells in dairy cows and to elucidate the underlying mechanisms.

METHODS

Firstly, the GEPIA database was employed to perform survival analysis on STC2 expression in relation to prognosis using TCGA and GETx data. Subsequently, the basic physical and chemical properties, gene expression, and potential signaling pathways involved in the growth of dairy cow mammary epithelial cells were determined using STC2 knockdown.

RESULTS

STC2 knockdown significantly suppressed autophagy in mammary epithelial cells of dairy cows. Moreover, STC2 knockdown upregulated GPX4 protein expression, elicited an elevation in Lipid ROS levels, and inhibited the mTORC1 signaling pathway, consequently repressing downstream genes involved in lipid synthesis regulated by mTORC1 and ultimately inducing ferroptosis.

CONCLUSIONS

The findings of our study suggest that STC2 suppresses autophagy and ferroptosis through the activation of mTORC1. Mechanically, STC2 exerts an inhibitory effect on ferroptosis by activating antioxidative stress-related proteins, such as GPX4, to suppress Lipid ROS production and stimulating the mTORC1 signaling pathway to enhance the expression of genes associated with lipid synthesis.

EPAS1 expression contributes to maintenance of the primordial follicle pool in the mouse ovary

Oxygen availability can have profound effects on cell fate decisions and survival, in part by regulating expression of hypoxia-inducible factors (HIFs). In the ovary, HIF expression has been characterised in granulosa cells, however, any requirement in oocytes remains relatively undefined. Here we developed a Hif2a/Epas1 germline-specific knockout mouse line in which females were fertile, however produced 40% fewer pups than controls. No defects in follicle development were detected, and quality of MII oocytes was normal, as per assessments of viability, intracellular reactive oxygen species, and spindle parameters. However, a significant diminishment of the primordial follicle pool was evident in cKO females that was attributed to accelerated follicle loss from postnatal day 6 onwards, potentially via disruption of the autophagy pathway. These data demonstrate the importance of HIF signalling in oocytes, particularly at the primordial follicle stage, and lend to the importance of controlling oxygen tension in the development of in vitro growth and maturation approaches for assisted reproduction.

Rosmarinic acid alleviates toosendanin-induced liver injury through restoration of autophagic flux and lysosomal function by activating JAK2/STAT3/CTSC pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Rosmarinic acid (RA), a natural polyphenol abundant in numerous herbal remedies, has been attracting growing interest owing to its exceptional ability to protect the liver. Toosendanin (TSN), a prominent bioactive compound derived from Melia toosendan Siebold & Zucc., boasts diverse pharmacological properties. Nevertheless, TSN possesses remarkable hepatotoxicity. Intriguingly, the potential of RA to counteract TSN-induced liver damage and its probable mechanisms remain unexplored.

AIM OF THE STUDY

This study is aimed at exploring whether RA can alleviate TSN-induced liver injury and the potential mechanisms involved autophagy.

MATERIALS AND METHODS

CCK-8 and LDH leakage rate assay were used to evaluate cytotoxicity. Balb/c mice were intraperitoneally administered TSN (20 mg/kg) for 24 h after pretreatment with RA (0, 40, 80 mg/kg) by gavage for 5 days. The autophagic proteins P62 and LC3B expressions were detected using western blot and immunohistochemistry. RFP-GFP-LC3B and transmission electron microscopy were applied to observe the accumulation levels of autophagosomes and autolysosomes. LysoTracker Red and DQ-BSA staining were used to evaluate the lysosomal acidity and degradation ability respectively. Western blot, immunohistochemistry and immunofluorescence staining were employed to measure the expressions of JAK2/STAT3/CTSC pathway proteins. Dual-luciferase reporter gene was used to measure the transcriptional activity of CTSC and RT-PCR was used to detect its mRNA level. H&E staining and serum biochemical assay were employed to determine the degree of damage to the liver.

RESULTS

TSN-induced damage to hepatocytes and livers was significantly alleviated by RA. RA markedly diminished the autophagic flux blockade and lysosomal dysfunction caused by TSN. Mechanically, RA alleviated TSN-induced down-regulation of CTSC by activating JAK2/STAT3 signaling pathway.

CONCLUSION

RA could protect against TSN-induced liver injury by activating the JAK2/STAT3/CTSC pathway-mediated autophagy and lysosomal function.

Micro(nano)-plastics exposure induced programmed cell death and corresponding influence factors

Plastic products have played an indispensable role in our daily lives for several decades, primarily due to their cost-effectiveness and unmatched convenience. Nevertheless, recent developments in nanotechnology have propelled our attention toward a distinct category of plastic fine particulates known as micro(nano)-plastics (MPs/NPs). The investigation of the cytotoxic effects of MPs/NPs has emerged as a central and burgeoning area of research in environmental toxicology and cell biology. In the scope of this comprehensive review, we have meticulously synthesized recent scientific inquiries to delve into the intricate interplay between MPs/NPs and programmed cell death mechanisms, which encompass a range of highly regulated processes. First, the signaling pathways and molecular mechanisms of different programmed death modalities induced by MPs/NPs were elaborated, including apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. The causes of different programmed deaths induced by MPs/NPs, such as size, surface potential, functional group modification, aging, biological crown, and co-exposure of MPs/NPs are further analyzed. In contrast, the various cellular programmed death modes induced by MPs/NPs are not alone most of the time, and lastly, the connections between different cellular programmed death modes induced by MPs/NPs, such as interconversion, mutual promotion, and mutual inhibition, are explained. Our primary objective is to unveil the multifaceted toxicological implications of MPs/NPs on the intricate web of cellular fate and biological homeostasis. This endeavor not only broadens our understanding of the potential risks associated with MPs/NPs exposure but also underscores the urgent need for comprehensive risk assessments and regulatory measures in the context of environmental health.

The mechanism by which SIRT1 regulates autophagy and EMT in drug-resistant oesophageal cancer cells

Cancer cell resistance presents a significant clinical challenge. The mechanisms underlying drug resistance in cancer cells are intricate and remain incompletely understood. Notably, tumor cell resistance often coincides with the epithelial-mesenchymal transition (EMT). In this study, we observed an elevation in autophagy levels following the development of drug resistance in oesophageal cancer cells. Inhibition of autophagy led to a reduction in drug-resistant cell migration and the inhibition of EMT. Furthermore, we identified an upregulation of SIRT1 expression in drug-resistant oesophageal cancer cells. Subsequent inhibition of SIRT1 expression in drug-resistant cells resulted in the suppression of autophagy levels, migration ability, and the EMT process. Our additional investigations revealed that a SIRT1 inhibitor effectively curbed tumor growth in human oesophageal cancer xenograft model mice (TE-1, TE-1/PTX) without evident toxic effects. This mechanism appears to be associated with the autophagy levels within the tumor tissue.

Naringenin alleviates liver fibrosis by triggering autophagy-dependent ferroptosis in hepatic stellate cells

Inhibition of activated hepatic stellate cells (HSCs) is a promising approach for treating liver fibrosis, and the ferroptosis has emerged as a pivotal mechanism to achieve this inhibition. The effects of naringenin, a flavonoid with anti-inflammatory properties, have not been thoroughly examined in liver fibrosis. Therefore, we used cholestasis model to study the effect of naringenin on liver fibrosis. Our findings demonstrated a significant exacerbation of liver tissue damage and fibrosis in mice subjected to bile duct ligation (BDL), accompanied by a substantial upregulation of fibrogenesis-related gene expression. Notably, naringenin administration markedly alleviated liver injury and fibrosis in these mice. Furthermore, naringenin exhibited inhibitory effects on the activation of HSCs, concurrently inducing ferroptosis. Importantly, naringenin significantly increased autophagic activity in HSCs. This effect was counteracted by co-administration of the autophagy inhibitor 3-MA, leading to a notable reduction in naringenin-induced HSC ferroptosis. In BDL model mice, naringenin demonstrated a mitigating effect on liver fibrosis, suggesting a potential correlation with naringenin-induced ferroptosis of HSCs. These results provide novel insights into the molecular mechanisms of naringenin-induced ferroptosis and highlight autophagy-dependent ferroptosis as a promising therapeutic strategy for liver fibrosis.

Deciphering pancreatic neuroendocrine tumors: Unveiling through circulating small extracellular vesicles

The survival rate over a five-year period for rare pancreatic neuroendocrine tumors (PanNET) is notably lower compared to other neuroendocrine tumors due to late-stage detection, which is a consequence of the absence of suitable diagnostic markers; therefore, there exists a critical need for an early-stage biomarker-specific to PanNETs. This study introduces a novel approach, investigating the impact of small extracellular vesicles (sEV) in PanNET growth and metastasis. As proof of concept, this study shows a correlation between sEV concentration in controls and PanNET. Notably, higher sEV concentrations were observed in PanNETs than in controls (p < 0.0001) with a sensitivity of 100%. Further, apparent differences were observed in the sEV concentrations between controls and grades 1 PanNET (p = 0.005). The expression of sEV markers was confirmed using CD63, TSG101, CD9, Flotillin-1, and GAD65 antibodies. Additionally, the expression of cancer marker BIRC2/cIAP1 (p = 0.002) and autophagy marker Beclin-1 (p = 0.02) were observed in plasma-derived sEVs and PanNET tissue. This study represents the first to indicate the increased secretion of sEV in PanNET patients' blood plasma, proposing potential function of sEV as a new biomarker for early-stage PanNET detection.

Crosstalk between autophagy and ferroptosis mediate injury in ischemic stroke by generating reactive oxygen species

Stroke represents a significant threat to global human health, characterized by high rates of morbidity, disability, and mortality. Predominantly, strokes are ischemic in nature. Ischemic stroke (IS) is influenced by various cell death pathways, notably autophagy and ferroptosis. Recent studies have increasingly highlighted the interplay between autophagy and ferroptosis, a process likely driven by the accumulation of reactive oxygen species (ROS). Post-IS, either the inhibition of autophagy or its excessive activation can escalate ROS levels. Concurrently, the interaction between ROS and lipids during ferroptosis further augments ROS accumulation. Elevated ROS levels can provoke endoplasmic reticulum stress-induced autophagy and, in conjunction with free iron (Fe2+), can trigger ferroptosis. Moreover, ROS contribute to protein and lipid oxidation, endothelial dysfunction, and an inflammatory response, all of which mediate secondary brain injury following IS. This review succinctly explores the mechanisms of ROS-mediated crosstalk between autophagy and ferroptosis and the detrimental impact of increased ROS on IS. It also offers novel perspectives for IS treatment strategies.

DNA damage-regulated autophagy modulator 1 prevents glioblastoma cells proliferation by regulating lysosomal function and autophagic flux stability

Glioblastoma (GBM) is the most aggressive and life-threatening brain tumor, characterized by its highly malignant and recurrent nature. DNA damage-regulated autophagy modulator 1 (DRAM-1) is a p53 target gene encoding a lysosomal protein that induces macro-autophagy and damage-induced programmed cell death in tumor growth. However, the precise mechanisms underlying how DRAM-1 affects tumor cell proliferation through regulation of lysosomal function and autophagic flux stability remain incompletely understood. We found that DRAM-1 expressions were evidently down-regulated in high-grade glioma and recurrent GBM tissues. The upregulation of DRAM-1 could increase mortality of primary cultured GBM cells. TEM analysis revealed an augmented accumulation of aberrant lysosomes in DRAM-1-overexpressing GBM cells. The assay for lysosomal pH and stability also demonstrated decreasing lysosomal membrane permeabilization (LMP) and impaired lysosomal acidity. Further research revealed the detrimental impact of lysosomal dysfunction, which impaired the autophagic flux stability and ultimately led to GBM cell death. Moreover, downregulation of mTOR phosphorylation was observed in GBM cells following upregulation of DRAM-1. In vivo and in vitro experiments additionally illustrated that the mTOR inhibitor rapamycin increased GBM cell mortality and exhibited an enhanced antitumor effect.

Chondroprotective effects of Apolipoprotein D in knee osteoarthritis mice through the PI3K/AKT/mTOR signaling pathway

BACKGROUND

Because the pathophysiology of osteoarthritis (OA) has not been fully elucidated, targeted treatments are lacking. In this study, we assessed the role and underlying mechanism apolipoprotein D (APOD) on the development of OA.

METHODS

To establish an in vitro OA model, we extracted primary chondrocytes from the cartilage of C57BL/6 mice and stimulated the chondrocytes with IL-1β. After APOD intervention or incubation with an overexpressing plasmid, we detected inflammatory-related markers using RT-qPCR, Western blotting, and ELISA. To detect apoptosis and autophagy-related markers, we used flow cytometry, immunofluorescence, and transmission electron microscopy (TEM). Finally, we measured the level of oxidative stress. We also used RNA-seq to identify the APOD-regulated downstream signaling pathways. We used an in vivo mice OA model of the anterior cruciate ligament transection (ACLT) and administered intra-articular adenovirus overexpressing APOD. To examine cartilage damage severity, we used immunohistochemical analysis (IHC), micro-CT, scanning electron microscopy (SEM), and Safranin O-fast green staining.

RESULTS

Our results showed that APOD inhibited chondrocyte inflammation, degeneration, and apoptosis induced by IL-1β. Additionally, APOD reversed autophagy inhibition and oxidative stress and also blocked activation of the PI3K/AKT/mTOR signaling pathway induced by IL-1β. Finally, overexpression of the APOD gene through adenovirus was sufficient to mitigate OA progression.

CONCLUSIONS

Our findings revealed that APOD had a chondroprotective role in OA progression by the PI3K/AKT/mTOR signaling pathway.

LncRNA MALAT1 suppresses monocyte-endothelial cell interactions by targeting miR-30b-5p and enhancing ATG5-mediated autophagy

Background

Monocyte-endothelial cell (EC) interactions are one of the earliest events in the development of atherosclerosis and play a crucial role in atherosclerotic plaque formation. Although attempts have been made to modulate this interaction, the underlying molecular signalling mechanisms remain unclear. This study aimed to investigate the role of long non-coding RNA MALAT1 in monocyte-EC interactions.

Methods

The expression of MALAT1, ICAM-1, VCAM-1, P-selectin, CCL2 and CXCL1 was evaluated in ApoE-/- mouse aortic tissues and inflamed human umbilical vein endothelial cells (HUVECs). The regulatory impact of MALAT1 on cell adhesion molecules, monocyte-EC adhesion, and autophagy was assessed. The interactions between MALAT1 and microRNAs (miRNAs) were evaluated using dual-luciferase reporter and RNA pull-down assays.

Results

MALAT1 expression decreased in ApoE-/- mouse aortic tissues and inflammatory HUVECs. MALAT1 overexpression suppressed the expression of ICAM-1, VCAM-1 and CXCL1, and reduced the migration and adhesion of monocytes to ECs. Inhibition of MALAT1 promoted cell adhesion molecule expression and monocyte-EC interactions. Mechanistically, MALAT1 binds directly to miR-30b-5p and decreases its effective expression by functioning as an endogenous sponge, thereby increasing the expression of autophagy-related gene 5 (ATG5) and stimulates endothelial autophagy.

Conclusions

Our findings suggest that MALAT1 suppresses monocyte-EC interactions by targeting miR-30b-5p and enhancing ATG5-mediated endothelial autophagy. These data imply that MALAT1 may play a protective role at the early stages of the atherosclerotic process.

Tl(I) and Tl(III)-induce genotoxicity, reticulum stress and autophagy in PC12 Adh cells

Thallium (Tl) and its two cationic species, Tl(I) and Tl(III), are toxic for most living beings. In this work, we investigated the effects of Tl (10-100 µM) on the viability and proliferation capacity of the adherent variant of PC12 cells (PC12 Adh cells). While both Tl(I) and Tl(III) halted cell proliferation from 24 h of incubation, their viability was ~ 90% even after 72 h of treatment. At 24 h, increased levels of γH2AX indicated the presence of DNA double-strand breaks. Simultaneously, increased expression of p53 and its phosphorylation at Ser15 were observed, which were associated with decreased levels of p-AKTSer473 and p-mTORSer2448. At 72 h, the presence of large cytoplasmic vacuoles together with increased autophagy predictor values suggested that Tl may induce autophagy in these cells. This hypothesis was corroborated by images obtained by transmission electron microscopy (TEM) and from the decreased expression at 72 h of incubation of SQSTM-1 and increased LC3β-II to LC3β-I ratio. TEM images also showed enlarged ER that, together with the increased expression of IRE1-α from 48 h of incubation, indicated that Tl-induced ER stress preceded autophagy. The inhibition of autophagy flux with chloroquine increased cell mortality, suggesting that autophagy played a cytoprotective role in Tl toxicity in these cells. Together, results indicate that Tl(I) or Tl(III) are genotoxic to PC12 Adh cells which respond to the cations inducing ER stress and cytoprotective autophagy.

Human β-defensin-1 affects the mammalian target of rapamycin pathway and autophagy in colon cancer cells through long non-coding RNA TCONS_00014506

BACKGROUND

Colorectal cancer has a low 5-year survival rate and high mortality. Human β-defensin-1 (hBD-1) may play an integral function in the innate immune system, contributing to the recognition and destruction of cancer cells. Long non-coding RNAs (lncRNAs) are involved in the process of cell differentiation and growth.

AIM

To investigate the effect of hBD-1 on the mammalian target of rapamycin (mTOR) pathway and autophagy in human colon cancer SW620 cells.

METHODS

CCK8 assay was utilized for the detection of cell proliferation and determination of the optimal drug concentration. Colony formation assay was employed to assess the effect of hBD-1 on SW620 cell proliferation. Bioinformatics was used to screen potentially biologically significant lncRNAs related to the mTOR pathway. Additionally, p-mTOR (Ser2448), Beclin1, and LC3II/I expression levels in SW620 cells were assessed through Western blot analysis.

RESULTS

hBD-1 inhibited the proliferative ability of SW620 cells, as evidenced by the reduction in the colony formation capacity of SW620 cells upon exposure to hBD-1. hBD-1 decreased the expression of p-mTOR (Ser2448) protein and increased the expression of Beclin1 and LC3II/I protein. Furthermore, bioinformatics analysis identified seven lncRNAs (2 upregulated and 5 downregulated) related to the mTOR pathway. The lncRNA TCONS_00014506 was ultimately selected. Following the inhibition of the lncRNA TCONS_00014506, exposure to hBD-1 inhibited p-mTOR (Ser2448) and promoted Beclin1 and LC3II/I protein expression.

CONCLUSION

hBD-1 inhibits the mTOR pathway and promotes autophagy by upregulating the expression of the lncRNA TCONS_00014506 in SW620 cells.

13-Oxyingenol-dodecanoate inhibits the growth of non-small cell lung cancer cells by targeting ULK1

Lung cancer is the leading cause of cancer deaths worldwide. Non-small cell lung cancer (NSCLC) accounts for 80-85% of all lung cancers. Euphorbia kansui yielded 13-oxyingenol-dodecanoate (13OD), an ingenane-type diterpenoid, which had a strong cytotoxic effect on NSCLC cells. The underlying mechanism and potential target, however, remained unknown. The study found that 13OD effectively inhibited the cell proliferation and colony formation of NSCLC cells (A549 and H460 cells), with less toxicity in normal human lung epithelial BEAS-2B cells. Moreover, 13OD can cause mitochondrial dysfunction, and apoptosis in NSCLC cells. Mechanistically, the transcriptomics results showed that differential genes were mainly enriched in the mTOR and AMPK signaling pathways, which are closely related to cellular autophagy, the related indicators were subsequently validated. Additionally, bafilomycin A1 (Baf A1), an autophagy inhibitor, reversed the mitochondrial damage caused by 13OD. Furthermore, the Omics and Text-based Target Enrichment and Ranking (OTTER) method predicted ULK1 as a potential target of 13OD against NSCLC cells. This hypothesis was further confirmed using molecular docking, the cellular thermal shift assay (CETSA), and Western blot analysis. Remarkably, ULK1 siRNA inhibited 13OD's toxic activity in NSCLC cells. In line with these findings, 13OD was potent and non-toxic in the tumor xenograft model. Our findings suggested a possible mechanism for 13OD's role as a tumor suppressor and laid the groundwork for identifying targets for ingenane-type diterpenoids.

Acupoints catgut embedding recovers leptin resistance via improving autophagy progress mediated by AMPK-mTOR signaling in obese mice

Purpose

Leptin resistance represents a primary pathological manifestation in obesity. Investigating potential treatments and associated mechanisms to restore leptin sensitivity is crucial for effective obesity management. This study aimed to explore the therapeutic potential of acupoints catgut embedding (ACE) in addressing obesity and its associated leptin resistance.

Methods

A simple obesity model was established by subjecting C57 male mice to a high-fat diet (HFD) for 12 weeks, followed by ACE treatment administered to half of the obese mice for a duration of 4 weeks. The levels of leptin and its receptor-lepRb, were assessed using enzyme-linked immunosorbent assay (ELISA) and Western blot analysis, respectively. Autophagy progression markers were evaluated through quantitative polymerase chain reaction (qPCR) and Western blot analysis. Also, the liver autophagosomes were photographed using electron microscopy. The role of autophagy in regulating leptin resistance was elucidated using an autophagy suppression model.

Results

Comparative analyses demonstrated that ACE treatment resulted in a significant reduction in body weight and blood lipid levels compared to the HFD group. Furthermore, serum leptin levels decreased, while liver lepRb expression increased following ACE treatment. The mRNA and protein expression levels of autophagy in liver were adjusted by ACE treatment. Interestingly, the beneficial effects of ACE were attenuated upon the administration of an autophagy inhibitor. Additionally, ACE treatment led to the activation of the AMPK-mTOR signaling pathway, a crucial regulator of autophagy.

Conclusion

These findings suggest that ACE therapy holds promise for recovering leptin resistance by enhancing autophagy progression, mediated via the AMPK-mTOR signaling pathway in liver.

Suppression of hypoxia-induced CAV1 autophagic degradation enhances nanoalbumin-paclitaxel transcytosis and improves therapeutic activity in pancreatic cancer

Nanoalbumin-paclitaxel (nab-paclitaxel) is a standard chemotherapy for pancreatic cancer but has shown limited efficacy. However, the mechanism through which circulating nab-paclitaxel passes through the tumour vascular endothelium has not been determined. In our study, a new nonradioactive and highly sensitive method for analysing nab-paclitaxel transcytosis was established. Based on these methods, we found that hypoxia significantly enhanced the autophagic degradation of CAV1 and therefore attenuated caveolae-mediated nab-paclitaxel transcytosis across endothelial cells (ECs). In a proof-of-concept experiment, higher levels of CAV1, accompanied by lower levels of LC3B, were observed in the vascular endothelium of pancreatic cancer tissues collected from patients who showed a good response to nab-paclitaxel compared with those from patients who showed a poor response to nab-paclitaxel. Furthermore, both in vivo and in vitro studies confirmed that suppressing the autophagic degradation of CAV1 via EC-specific ATG5 knockdown or hydroxychloroquine sulfate (HCQ) treatment significantly enhanced nab-paclitaxel translocation across the endothelial barrier into pancreatic cancer cells and amplified the inhibitory effect of nab-paclitaxel on pancreatic tumour growth. The stimulation of CAV1 expression by EC-specific overexpression of exogenous CAV1 or administration of gemcitabine hydrochloride (GE) had the same effect. These results demonstrated that suppressing CAV1 autophagic degradation is a novel translatable strategy for enhancing nab-paclitaxel chemotherapeutic activity in the treatment of pancreatic cancer.

Acute lung injury: a view from the perspective of necroptosis

BACKGROUND

ALI/ARDS is a syndrome of acute onset characterized by progressive hypoxemia and noncardiogenic pulmonary edema as the primary clinical manifestations. Necroptosis is a form of programmed cell necrosis that is precisely regulated by molecular signals. This process is characterized by organelle swelling and membrane rupture, is highly immunogenic, involves extensive crosstalk with various cellular stress mechanisms, and is significantly implicated in the onset and progression of ALI/ARDS.

METHODS

The current body of literature on necroptosis and ALI/ARDS was thoroughly reviewed. Initially, an overview of the molecular mechanism of necroptosis was provided, followed by an examination of its interactions with apoptosis, pyroptosis, autophagy, ferroptosis, PANOptosis, and NETosis. Subsequently, the involvement of necroptosis in various stages of ALI/ARDS progression was delineated. Lastly, drugs targeting necroptosis, biomarkers, and current obstacles were presented.

CONCLUSION

Necroptosis plays an important role in the progression of ALI/ARDS. However, since ALI/ARDS is a clinical syndrome caused by a variety of mechanisms, we emphasize that while focusing on necroptosis, it may be more beneficial to treat ALI/ARDS by collaborating with other mechanisms.

Targeting PNPO to suppress tumor growth via inhibiting autophagic flux and to reverse paclitaxel resistance in ovarian cancer

Our previous study showed that pyridoxine 5'-phosphate oxidase (PNPO) is a tissue biomarker of ovarian cancer (OC) and has a prognostic implication but detailed mechanisms remain unclear. The current study focused on PNPO-regulated lysosome/autophagy-mediated cellular processes and the potential role of PNPO in chemoresistance. We found that PNPO was overexpressed in OC cells and was a prognostic factor in OC patients. PNPO significantly promoted cell proliferation via the regulation of cyclin B1 and phosphorylated CDK1 and shortened the G2M phase in a cell cycle. Overexpressed PNPO enhanced the biogenesis and perinuclear distribution of lysosomes, promoting the degradation of autophagosomes and boosting the autophagic flux. Further, an autolysosome marker LAMP2 was upregulated in OC cells. Silencing LAMP2 suppressed cell growth and induced cell apoptosis. LAMP2-siRNA blocked PNPO action in OC cells, indicating that the function of PNPO on cellular processes was mediated by LAMP2. These data suggest the existence of the PNPO-LAMP2 axis. Moreover, silencing PNPO suppressed xenographic tumor formation. Chloroquine counteracted the promotion effect of PNPO on autophagic flux and inhibited OC cell survival, facilitating the inhibitory effect of PNPO-shRNA on tumor growth in vivo. Finally, PNPO was overexpressed in paclitaxel-resistant OC cells. PNPO-siRNA enhanced paclitaxel sensitivity in vitro and in vivo. In conclusion, PNPO has a regulatory effect on lysosomal biogenesis that in turn promotes autophagic flux, leading to OC cell proliferation, and tumor formation, and is a paclitaxel-resistant factor. These data imply a potential application by targeting PNPO to suppress tumor growth and reverse PTX resistance in OC.

Evaluation of Mitochondrial Phagy (Mitophagy) in Human Non-small Adenocarcinoma Tumor Cells

Non-small cell lung cancer (NSCLC) is a predominant form of lung cancer characterized by its aggressive nature and high mortality rate, primarily due to late-stage diagnosis and metastatic spread. Recent studies underscore the pivotal role of mitophagy, a selective form of autophagy targeting damaged or superfluous mitochondria, in cancer biology, including NSCLC. Mitophagy regulation may influence cancer cell survival, proliferation, and metastasis by modulating mitochondrial quality and cellular energy homeostasis. Herein, we present a comprehensive methodology developed in our laboratory for the evaluation of mitophagy in NSCLC tumor cells. Utilizing a combination of immunoblotting, immunocytochemistry, and fluorescent microscopy, we detail the steps to quantify early and late mitophagy markers and mitochondrial dynamics. Our findings highlight the potential of targeting mitophagy pathways as a novel therapeutic strategy in NSCLC, offering insights into the complex interplay between mitochondrial dysfunction and tumor progression. This study not only sheds light on the significance of mitophagy in NSCLC but also establishes a foundational approach for its investigation, paving way for future research in this critical area of cancer biology.