Hyaluronan synthase 2, a target of miR-200c, promotes carbon tetrachloride-induced acute and chronic liver inflammation via regulation of CCL3 and CCL4

Fully Bioactive Nanodrugs: Stem Cell-Derived Exosomes Engineered with Biomacromolecules to Treat CCl4- and Extreme Hepatectomy-Induced Acute Liver Failure

Acute liver failure (ALF) is a serious global disease characterized by rapid onset and high mortality. Currently, the clinical treatment of ALF faces considerable hurdles due to limited medication options and the scarcity of liver transplants. Despite biomacromolecules such as hepatocyte growth factor (HGF) and glutathione (GSH) having been applied for ALF symptom relief in the clinic, they still face substantial challenges including poor stability, difficulty in acting on intracellular targets, and inadequate therapeutic outcome. In this work, by taking advantage of the innate targeting and regenerative capabilities of mesenchymal stem cells (MSCs), we harnessed MSC-derived exosomes as natural bioactive carriers for the simultaneous delivery of HGF and GSH, forming a fully bioactive nanodrug termed HG@Exo. Impressively, the HG@Exo demonstrated potent therapeutic effects against both carbon tetrachloride (CCl4)- and extreme hepatectomy-induced ALF through multiple mechanisms, including regulation of oxidative stress, reduction of inflammation, and promotion of hepatocyte regeneration, which were facilitated by its inflammation-targeting to damaged liver tissues. Furthermore, an FDA-approved near-infrared fluorescent dye, indocyanine green (ICG), has been incorporated into the exosomes (HGI@Exo) to endow them with real-time in vivo tracking capability, which showed favorable liver accumulation of the HGI@Exo in both CCl4- and surgery-induced ALF animal models, providing crucial insights into their biodistribution and therapeutic efficacy. Overall, the presented fully bioactive nanodrugs with targeting and theranostic abilities hold significant promise for potentiating the therapeutic efficacy of biomacromolecules for the improved treatment of ALF and other inflammatory diseases.

Quercetin-primed BMSC-derived extracellular vesicles ameliorate chronic liver damage through miR-136-5p and GNAS/STAT3 signaling pathways

BACKGROUND

Chronic liver damage (CLD) is a long-term and progressive liver condition characterized by inflammation, fibrosis, and impaired liver function, which ultimately lead to severe complications such as cirrhosis or liver cancer. Quercetin (Que), a flavonoid in various plants, possesses anti-inflammatory, antiviral, anti-ischemic, and anticancer properties. Recently, extracellular vesicles (EVs) derived from pretreated bone marrow mesenchymal stem cells (BMSCs) have shown immense potential in treating various diseases, including CLD. Thus, this study evaluated the regulatory effects of Que-preconditioned BMSC-derived EVs (Que-EVs) on LPS-stimulated RAW264.7 cells and their therapeutic effects on mice with CLD.

METHODS

Que-EVs and control-EVs were harvested from the cell culture supernatant of BMSCs. The EVs were characterized using western blot, transmission electron microscopy, and nanoparticle tracking analysis. Further, the DIR labeling of EVs was used to detect in vitro and in vivo uptake. Next, LPS pre-stimulated RAW264.7 cells were treated with Que-EVs and control-EVs for 24 h. The relative expression of inflammatory cytokines and macrophage polarization markers genes was assessed using RT-qPCR, and western blot was conducted to evaluate the GNAS, PI3K, ERK, and STAT3 gene and protein expressions in RAW264.7 cells. Furthermore, transfection techniques were employed to induce miR-136-5p inhibition and GNAS overexpression in RAW264.7 cells to validate the role of miR-136-5p in alleviating inflammation through the GNAS/PI3K/ERK/STAT3 pathway. Subsequently, the outcomes were validated via in vitro experiments.

RESULTS

Que enhanced miR-136-5p expression in BMSC-EVs. Furthermore, it was shown that EVs delivered miR-136-5p to macrophages, thereby attenuating M1-type macrophage polarisation through the GNAS/PI3K/ERK/STAT3 pathway, reducing liver inflammation, improving liver function and treating CLD.

Non-invasive diagnosis of liver fibrosis via MRI using targeted gadolinium-based nanoparticles

INTRODUCTION

Accurate diagnosis of liver fibrosis is crucial for preventing cirrhosis and liver tumors. Liver fibrosis is driven by activated hepatic stellate cells (HSCs) with elevated CD44 expression. We developed hyaluronic acid (HA)-coated gadolinium-based nanoprobes to specifically target CD44 for diagnosing liver fibrosis using T1-weighted magnetic resonance imaging (MRI).

MATERIALS AND METHODS

NaGdF4 nanoparticles (NPs) were synthesized via thermal decomposition and modified with polyethylene glycol (PEG) to obtain non-targeting NaGdF4@PEG NPs. These were subsequently coated with HA to target HSCs, resulting in liver fibrosis-targeting NaGdF4@PEG@HA nanoprobes. Characterization includedd transmission electron microscopy and X-ray diffraction. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8). Internalization of NaGdF4@PEG@HA nanoprobes by mouse HSCs JS1 cells via ligand-receptor interaction was observed using flow cytometry and confocal laser scanning microscopy (CLSM). Liver fibrosis was induced in C57BL/6 mice using a methionine-choline deficient (MCD) diet. MRI performance and nanoprobe distribution in fibrotic and normal livers were analyzed using a GE Discovery 3.0T MR 750 scanner.

RESULTS

NaGdF4@PEG@HA nanoprobes exhibited homogeneous morphology, low toxicity, and a high T1 relaxation rate (7.645 mM⁻¹s⁻¹). CLSM and flow cytometry demonstrated effective phagocytosis of NaGdF4@PEG@HA nanoprobes by JS1 cells compared to NaGdF4@PEG. MRI scans revealed higher T1 signals in fibrotic livers compared to normal livers after injection of NaGdF4@PEG@HA. NaGdF4@PEG@HA demonstrated higher targeting ability in fibrotic mice.

CONCLUSIONS

NaGdF4@PEG@HA nanoprobes effectively target HSCs with high T1 relaxation rate, facilitating efficient MRI diagnosis of liver fibrosis.

Atractylodes Lancea and Its Constituent, Atractylodin, Ameliorates Metabolic Dysfunction-Associated Steatotic Liver Disease via AMPK Activation

Metabolic dysfunction-associated steatotic liver disease (MASLD), which encompasses a spectrum of conditions ranging from simple steatosis to hepatocellular carcinoma, is a growing global health concern associated with insulin resistance. Since there are limited treatment options for MASLD, this study investigated the therapeutic potential of Atractylodes lancea, a traditional herbal remedy for digestive disorders in East Asia, and its principal component, atractylodin, in treating MASLD. Following 8 weeks of high-fat diet (HFD) feeding, mice received oral doses of 30, 60, or 120 mg/kg of Atractylodes lancea. In HFD-fed mice, Atractylodes lancea treatment reduced the body weight; serum triglyceride, total cholesterol, and alanine aminotransferase levels; and hepatic lipid content. Furthermore, Atractylodes lancea significantly ameliorated fasting serum glucose, fasting serum insulin, and homeostatic model assessment of insulin resistance levels in response to HFD. Additionally, a glucose tolerance test demonstrated improved glucose homeostasis. Treatment with 5 or 10 mg/kg atractylodin also resulted in anti-obesity, anti-steatosis, and glucose-lowering effects. Atractylodin treatment resulted in the downregulation of key lipogenic genes (Srebf1, Fasn, Scd2, and Dgat2) and the upregulation of genes regulated by peroxisome proliferator-activated receptor-α. Notably, the molecular docking model suggested a robust binding affinity between atractylodin and AMP-activated protein kinase (AMPK). Atractylodin activated AMPK, which contributed to SREBP1c regulation. In conclusion, our results revealed that Atractylodes lancea and atractylodin activated the AMPK signaling pathway, leading to improvements in HFD-induced obesity, fatty liver, and glucose intolerance. This study suggests that the phytochemical, atractylodin, can be a treatment option for MASLD.

Knockdown of Hyaluronan synthase 2 suppresses liver fibrosis in mice via induction of transcriptomic changes similar to 4MU treatment

Hepatic fibrosis remains a significant clinical challenge due to ineffective treatments. 4-methylumbelliferone (4MU), a hyaluronic acid (HA) synthesis inhibitor, has proven safe in phase one clinical trials. In this study, we aimed to ameliorate liver fibrosis by inhibiting HA synthesis. We compared two groups of mice with CCl4-induced fibrosis, treated with 4-methylumbelliferone (4MU) and hyaluronan synthase 2 (HAS2) targeting siRNA (siHAS2). The administration of 4MU and siHAS2 significantly reduced collagen and HA deposition, as well as biochemical markers of hepatic damage induced by repeated CCl4 injections. The transcriptomic analysis revealed converging pathways associated with downstream HA signalling. 4MU- and siHAS2-treated fibrotic livers shared 405 upregulated and 628 downregulated genes. These genes were associated with xenobiotic and cholesterol metabolism, mitosis, endoplasmic reticulum stress, RNA processing, and myeloid cell migration. The functional annotation of differentially expressed genes (DEGs) in siHAS2-treated mice revealed attenuation of extracellular matrix-associated pathways. In comparison, in the 4MU-treated group, DEGs were related to lipid and bile metabolism pathways and cell cycle. These findings confirm that HAS2 is an important pharmacological target for suppressing hepatic fibrosis using siRNA.

A thioacetamide-induced liver fibrosis model for pre-clinical studies in microminipig

Drug-induced liver fibrosis models are used in normal and immunosuppressed small animals for transplantation and regenerative medicine to improve liver fibrosis. Although large animal models are needed for pre-clinical studies, they are yet to be established owing to drug sensitivity in animal species and difficulty in setting doses. In this study, we evaluated liver fibrosis by administering thioacetamide (TA) to normal microminipig and thymectomized microminipig; 3 times for 1 week (total duration: 8 weeks). The pigs treated with TA showed elevated blood cytokine levels and a continuous liver injury at 8 weeks. RNA-seq of the liver showed increased expression of fibrosis-related genes after TA treatment. Histopathological examination showed degenerative necrosis of hepatocytes around the central vein, and revealed fibrogenesis and hepatocyte proliferation. TA treatment caused CD3-positive T cells and macrophages scattered within the hepatic lobule to congregate near the center of the lobule and increased αSMA-positive cells. Thymectomized pigs showed liver fibrosis similar to that of normal pigs, although the clinical signs tended to be milder. This model is similar to pathogenesis of liver fibrosis reported in other animal models. Therefore, it is expected to contribute to research as a drug discovery and pre-clinical transplantation models.

Human embryonic stem cell-derived immunity-and-matrix regulatory cells promote intrahepatic cell renewal to rescue acute liver failure

Acute liver failure (ALF) is a clinical syndrome characterized by the accelerated development of hepatocyte necrosis and significant mortality. Given that liver transplantation is now the only curative treatment available for ALF, there is an urgent need to explore innovative therapies. Mesenchymal stem cells (MSCs) have been applied in preclinical studies for ALF. It had been demonstrated that human embryonic stem cell-derived immunity-and-matrix regulatory cells (IMRCs) met the properties of MSCs and had been employed in a wide range of conditions. In this study, we conducted a preclinical evaluation of IMRCs in the treatment of ALF and investigated the mechanism involved. ALF was induced in C57BL/6 mice via intraperitoneal administration of 50% CCl₄ (6 mL/kg) mixed with corn oil, followed by intravenous injection of IMRCs (3 × 10⁶ cells/each). IMRCs improved histopathological changes in the liver and reduced alanine transaminase (ALT) or aspartate transaminase (AST) levels in serum. IMRCs also promoted cell renewal in the liver and protected it from CCl₄ damage. Furthermore, our data indicated that IMRCs protected against CCl₄-induced ALF by regulating the IGFBP2-mTOR-PTEN signaling pathway, which is associated with the repopulation of intrahepatic cells. Overall, IMRCs offered protection against CCl₄-induced ALF and were capable of preventing apoptosis and necrosis in hepatocytes, which provided a new perspective for treating and improving the prognosis of ALF.

Hyaluronan in liver fibrosis: basic mechanisms, clinical implications, and therapeutic targets

Hyaluronan (HA), also known as hyaluronic acid, is a glycosaminoglycan that is a critical component of the extracellular matrix (ECM). Production and deposition of ECM is a wound-healing response that occurs during chronic liver disease, such as cirrhosis. ECM production is a sign of the disease progression of fibrosis. Indeed, the accumulation of HA in the liver and elevated serum HA levels are used as biomarkers of cirrhosis. However, recent studies also suggest that the ECM, and HA in particular, as a functional signaling molecule, facilitates disease progression and regulation. The systemic and local levels of HA are regulated by de novo synthesis, cleavage, endocytosis, and degradation of HA, and the molecular mass of HA influences its pathophysiological effects. However, the regulatory mechanisms of HA synthesis and catabolism and the functional role of HA are still poorly understood in liver fibrosis. This review summarizes the role of HA in liver fibrosis at molecular levels as well as its clinical implications and discusses the potential therapeutic uses of targeting HA in liver fibrosis.

Analysis of potential immune-related genes involved in the pathogenesis of ischemia-reperfusion injury following liver transplantation

Background

Hepatic ischemia-reperfusion (I/R) injury is an unavoidable pathological process that occurs after liver transplantation. However, the immune-related molecular mechanism still remains unclear. This study aims to further explore the biological mechanisms of immune-related genes in hepatic I/R injury.

Methods

Gene microarray data was downloaded from the Gene Expression Omnibus (GEO) expression profile database and the differentially expressed genes (DEGs) were taken for intersection. After identifying common DEGs, functional annotation, protein-protein interaction (PPI) network, and modular construction were performed. The immune-related hub genes were obtained, which their upstream transcription factors and non-RNAs were predicted. Validation of the hub genes expression and immune infiltration were performed in a mouse model of hepatic I/R injury.

Results

A total of 71 common DEGs were obtained from three datasets (GSE12720, GSE14951, GSE15480). The GO and KEGG enrichment analysis results indicated that immune and inflammatory response played an important role in hepatic I/R injury. Finally, 9 immune-related hub genes were identified by intersecting cytoHubba with immune-related genes, including SOCS3, JUND, CCL4, NFKBIA, CXCL8, ICAM1, IRF1, TNFAIP3, and JUN.

Conclusion

Our study revealed the importance of the immune and inflammatory response in I/R injury following liver transplantation and provided new insights into the therapeutic of hepatic I/R injury.

Role of noncoding RNAs in liver fibrosis

Liver fibrosis is a wound-healing response following chronic liver injury caused by hepatitis virus infection, obesity, or excessive alcohol. It is a dynamic and reversible process characterized by the activation of hepatic stellate cells and excess accumulation of extracellular matrix. Advanced fibrosis could lead to cirrhosis and even liver cancer, which has become a significant health burden worldwide. Many studies have revealed that noncoding RNAs (ncRNAs), including microRNAs, long noncoding RNAs and circular RNAs, are involved in the pathogenesis and development of liver fibrosis by regulating signaling pathways including transforming growth factor-β pathway, phosphatidylinositol 3-kinase/protein kinase B pathway, and Wnt/β-catenin pathway. NcRNAs in serum or exosomes have been reported to tentatively applied in the diagnosis and staging of liver fibrosis and combined with elastography to improve the accuracy of diagnosis. NcRNAs mimics, ncRNAs in mesenchymal stem cell-derived exosomes, and lipid nanoparticles-encapsulated ncRNAs have become promising therapeutic approaches for the treatment of liver fibrosis. In this review, we update the latest knowledge on ncRNAs in the pathogenesis and progression of liver fibrosis, and discuss the potentials and challenges to use these ncRNAs for diagnosis, staging and treatment of liver fibrosis. All these will help us to develop a comprehensive understanding of the role of ncRNAs in liver fibrosis.