Background & Aims: The pathological hallmark of nonalcoholic fatty liver disease (NAFLD) is an imbalance in hepatic lipid homeostasis, in which lipophagy has been found to play a vital role. However, the underlying molecular mechanisms remain unclear. We investigated the role of chaperone-mediated autophagy (CMA) in the pathogenesis of NAFLD. Methods: CMA activity was evaluated in liver tissues from NAFLD patients and highfat diet (HFD)-fed mice. Liver-specific LAMP2A-knockout mice and HepG2 cells lacking LAMP2A [L2A(-) cells] were used to investigate the influence of CMA on lipolysis in hepatocytes. The expression of Plin5, a lipid droplet (LD)-related protein, was also evaluated in human and mouse liver tissues and in [L2A(-)] cells. Results: Here, we found disrupted CMA function in the livers of NAFLD patients and animal models, displaying obvious reduction of LAMP2A and concurrent with decreased levels of CMA-positive regulators. More LDs and higher serum triglycerides accumulated in liver-specific LAMP2A-knockout mice and L2A(-) cells under high-fat challenge. Meanwhile, deleting LAMP2A hindered LD breakdown but not increased LD formation. In addition, the LD-associated protein Plin5 is a CMA substrate, and its degradation through CMA is required for LD breakdown. Conclusions: We propose that the disruption of CMA-induced Plin5 degradation obstacles LD breakdown, explaining the lipid homeostasis imbalance in NAFLD.

Background Despite emerging evidence on the therapeutic potential of mesenchymal stem cells (MSCs) for liver fibrosis, the underlying mechanisms remain unclear. At present, MSC-derived exosomes (MSC-EXOs) are widely accepted as crucial messengers for intercellular communication. This study aimed to explore the therapeutic effects of MSC-EXOs on liver fibrosis and identify the mechanisms underlying the action of MSC-EXOs. Methods Carbon tetrachloride was used to induce a liver fibrosis model, which was intravenously administered with MSCs or MSC-EXOs to assess treatment efficacy. The resulting histopathology, fibrosis degree, inflammation and macrophage polarization were analyzed. RAW264.7 and BMDM cells were used to explore the regulatory effects of MSC-EXOs on macrophage polarization. Then, the critical miRNA mediating the therapeutic effects of MSC-EXOs was screened via RNA sequencing and validated experimentally. Furthermore, the target mRNA and downstream signaling pathways were elucidated by luciferase reporter assay, bioinformatics analysis and western blot. Results MSCs alleviated liver fibrosis largely depended on their secreted exosomes, which were visualized to circulate into liver after transplantation. In addition, MSC-EXOs were found to modulate macrophage phenotype to regulate inflammatory microenvironment in liver and repair the injury. Mechanically, RNA-sequencing illustrates that miR-148a, enriched in the MSC-EXOs, targets Kruppel-like factor 6 (KLF6) to suppress pro-inflammatory macrophages and promote anti-inflammatory macrophages by inhibiting the STAT3 pathway. Administration of miR-148a-enriched MSC-EXOs or miR-148a agomir shows potent ameliorative effects on liver fibrosis. Conclusions These findings suggest that MSC-EXOs protect against liver fibrosis via delivering miR-148a that regulates intrahepatic macrophage functions through KLF6/STAT3 signaling and provide a potential therapeutic target for liver fibrosis.

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BackgroundEvidence from prevailing studies show that hepatocellular carcinoma (HCC) is among the top cancers with high mortality globally. Gene regulation at post-transcriptional level orchestrated by RNA-binding proteins (RBPs) is an important mechanism that modifies various biological behaviors of HCC. Currently, it is not fully understood how RBPs affects the prognosis of HCC. In this study, we aimed to construct and validate an RBP-related model to predict the prognosis of HCC patients.MethodsDifferently expressed RBPs were identified in HCC patients based on the GSE54236 dataset from the Gene Expression Omnibus (GEO) database. Integrative bioinformatics analyses were performed to select hub genes. Gene expression patterns were validated in The Cancer Genome Atlas (TCGA) database, after which univariate and multivariate Cox regression analyses, as well as Kaplan-Meier analysis were performed to develop a prognostic model. Then, the performance of the prognostic model was assessed using receiver operating characteristic (ROC) curves and clinicopathological correlation analysis. Moreover, data from the International Cancer Genome Consortium (ICGC) database were used for external validation. Finally, a nomogram combining clinicopathological parameters and prognostic model was established for the individual prediction of survival probability.ResultsThe prognostic risk model was finally constructed based on two RBPs (BOP1 and EZH2), facilitating risk-stratification of HCC patients. Survival was markedly higher in the low-risk group relative to the high-risk group. Moreover, higher risk score was associated with advanced pathological grade and late clinical stage. Besides, the risk score was found to be an independent prognosis factor based on multivariate analysis. Nomogram including the risk score and clinical stage proved to perform better in predicting patient prognosis.ConclusionsThe RBP-related prognostic model established in this study may function as a prognostic indicator for HCC, which could provide evidence for clinical decision making.

Background: Primary biliary cholangitis (PBC) is an immune-mediated chronic cholestasis, in which T cell homeostasis plays an important role. Lysosomal-associated membrane protein 2 isoform A (LAMP-2A) has been implicated in the regulation of CD4 + T cell responses.Methods: We comprehensively evaluated the immunobiology of CD4 + T cells in patients with PBC (PBC, n=42), chronic hepatitis B (CHB, n=20), and healthy control subjects (HC, n=20) by flow cytometry including activation status and LAMP-2A expression. Additionally, we investigated the activation responses of PBC-naïve CD4 + T cells by stimulation in vitro and tested the changes caused by deleting the gene encoding LAMP-2A.Results: Firstly, we found an increased activation status of circulating CD4 + T cells from PBC patients compared to the HC subjects, and PBC-naïve CD4 + T cells showed enhanced responses after stimulation in vitro. Secondly, PBC-naïve CD4 + T cells expressed a significantly higher level of LAMP-2A compared to the HC and CHB groups [

<abstract> <p>Immune checkpoint genes (ICGs) have recently been proven to perform instrumental functions in the maintenance of immune homeostasis and represent a promising therapeutic strategy; however, their expression patterns and prognostic values are not fully elucidated in hepatocellular carcinoma (HCC). In this investigation, we focused on establishing and validating a prognostic gene signature to facilitate decision-making in clinical practice. Clinical information, as well as transcriptome data, was obtained from the Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) database. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) Cox method were employed to build a multi-gene signature in the TCGA database, while the ICGC database was used for validation. Subsequently, utilizing the six-gene signature, we were able to categorize patients into high- and low-risk groups. In two cohorts, survival analysis findings revealed a dismal outlook for the high-risk group. The receiver operating characteristic curves were utilized to estimate the gene signature's prediction ability. Moreover, correlation analysis showed high-risk group was linked to advanced pathological stage, infiltration of immune cells and therapeutic response. In summary, this unique gene profile might serve not only as a useful prognostic indicator but also as a marker of therapy responsiveness in HCC.</p> </abstract>

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