A Novel Hepatic Anti-Fibrotic Strategy Utilizing the Secretome Released from Etanercept-Synthesizing Adipose-Derived Stem Cells

The secretome obtained under hypoxic preconditioning from human adipose-derived stem cells exerts promoted anti-apoptotic potentials through upregulated autophagic process

BACKGROUND

Hypoxic preconditioning (HP) is a stem cell preconditioning modality designed to augment the therapeutic effects of mesenchymal stem cells (MSCs). Although autophagy is expected to play a role in HP, very little is known regarding the relationship between HP and autophagy.

METHODS AND RESULTS

The adipose-derived stem cell (ASC)-secretome obtained under normoxia (NCM) and ASC-secretome obtained under HP (HCM) were obtained by culturing ASCs for 24 h under normoxic (21% partial pressure of O₂) and hypoxic (1% partial pressure of O₂) conditions, respectively. Subsequently, to determine the in vivo effects of HCM, each secretome was injected into 70% partially hepatectomized mice, and liver specimens were obtained. HCM significantly reduced the apoptosis of thioacetamide-treated AML12 hepatocytes and promoted the autophagic processes of the cells (P < 0.05). Autophagy blockage by either bafilomycin A1 or ATG5 siRNA significantly abrogated the anti-apoptotic effect of HCM (P < 0.05), demonstrating that HCM exerts its anti-apoptotic effect by promoting autophagy. The effect of HCM - reduction of cell apoptosis and promotion of autophagic process - was also demonstrated in a mouse model.

CONCLUSIONS

HP appears to induce ASCs to release a secretome with enhanced anti-apoptotic effects by promoting the autophagic process of ASCs.

Evaluation of the Mechanism of Jiedu Huazhuo Quyu Formula in Treating Wilson's Disease-Associated Liver Fibrosis by Network Pharmacology Analysis and Molecular Dynamics Simulation

The Jiedu Huazhuo Quyu formula (JHQ) shows significant beneficial effects against liver fibrosis caused by Wilson's disease (WD). Hence, this study aimed to clarify the mechanisms of the JHQ treatment in WD-associated liver fibrosis. First, we collected 103 active compounds and 527 related targets of JHQ and 1187 targets related to WD-associated liver fibrosis from multiple databases. Next, 113 overlapping genes (OGEs) were obtained. Then, we built a protein-protein interaction (PPI) network with Cytoscape 3.7.2 software and performed the Gene Ontology (GO) term and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analyses with GENE DENOVO online sites. Furthermore, module analysis was performed, and the core target genes in the JHQ treatment of WD-associated liver fibrosis were obtained. Pathway and functional enrichment analyses, molecular docking studies, molecular dynamic (MD) simulation, and Western blot (WB) were then performed. The results indicated that 8 key active compounds including quercetin, luteolin, and obacunone in JHQ might affect the 6 core proteins including CXCL8, MAPK1, and AKT1 and 107 related signaling pathways including EGFR tyrosine kinase inhibitor resistance, Kaposi sarcoma-associated herpesvirus infection, and human cytomegalovirus infection signaling pathways to exhibit curative effects on WD-associated liver fibrosis. Mechanistically, JHQ might inhibit liver inflammatory processes and vascular hyperplasia, regulate the cell cycle, and suppress both the activation and proliferation of hepatic stellate cells (HSCs). This study provides novel insights for researchers to systematically explore the mechanism of JHQ in treating WD-associated liver fibrosis.

Ferrostatin-1 Ameliorates Liver Dysfunction via Reducing Iron in Thioacetamide-induced Acute Liver Injury in Mice

Background and Aims: Hepatic iron overload always leads to oxidative stress, which has been found to be involved in the progression of liver disease. However, whether iron disorder is involved in acute liver disease and the further molecular mechanisms remain unclear.

Methods: A mice model of acute liver injury (ALI) was established via intraperitoneal injection of thioacetamide (TAA) (250 mg/kg/day) for 3 consecutive days. Ferrostatin-1 (Fer-1) was administered intraperitoneally (2.5 μM/kg/day) starting 3 days before TAA treatment. Deferoxamine (DFO) was intraperitoneally injected (200 mg/kg/day) with TAA treatment for 3 days. We further observed the effect of Fer-1 on TAA model with high-iron diet feeding. ALI was confirmed using histological examination and liver function activity. Moreover, expressions of iron metabolism and ferroptosis proteins were measured by Western blot analysis.

Results: The study revealed that the iron accumulation and ferroptosis contributed to TAA-induced ALI pathogenesis. TAA induced prominent inflammation and vacuolar degeneration in the liver as well as liver dysfunction. In addition, protein expression of the cystine/glutamate antiporter SLC7A11 (xCT) and glutathione peroxidase 4 (GPX4) was significantly decreased in the liver, while transferrin receptor 1 (TfR1), ferroportin (Fpn) and light chain of ferritin (Ft-L) expression levels were increased after TAA exposure. As the same efficiency as DFO, pre-administration of Fer-1 significantly decreased TAA-induced alterations in the plasma ALT, AST and LDH levels compared with the TAA group. Moreover, both Fer-1 and DFO suppressed TfR1, Fpn and Ft-L protein expression and decreased iron accumulation, but did not affect xCT or GPX4 expression in the liver. Both Fer-1and DFO prevented hepatic ferroptosis by reducing the iron content in the liver. Furthermore, Fer-1 also reduced iron and reversed liver dysfunction under iron overload conditions.

Conclusion: These findings indicate a role of TAA-induced iron accumulation and ferroptosis in the pathogenesis of ALI model. The effect of Fer-1 was consistent with that of DFO, which prevented hepatic ferroptosis by reducing the iron content in the liver. Thus, Fer-1 might be a useful reagent to reverse liver dysfunction and decreasing the iron content of the liver may be a potential therapeutic strategy for ALI.

A promising antifibrotic drug, pyridoxamine attenuates thioacetamide-induced liver fibrosis by combating oxidative stress, advanced glycation end products, and balancing matrix metalloproteinases

Liver fibrosis is a common chronic hepatic disease. This study was done to examine the effect of pyridoxamine against thioacetamide-induced hepatic fibrosis. Animals were divided into four groups (1) control group; (2) Thioacetamide group (200 mg/kg, i.p.) twice a week for eight weeks; (3) Pyridoxamine-treated group treated with pyridoxamine (100 mg/kg/day, i.p.) for eight weeks; (4) Thioacetamide and pyridoxamine group, in which pyridoxamine was given (100 mg/kg/day, i.p.) during thioacetamide injections. Thioacetamide treatment resulted in hepatic dysfunction manifested by increased serum levels of bilirubin, gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). Oxidative stress was noted by increased hepatic lipid peroxidation and decreased glutathione (GSH). Increased concentrations of total nitrite/nitrate, advanced glycation end products (AGEs), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), matrix metalloproteinases (MMP-2&9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were noticed in hepatic tissues. Immunostaining sections also revealed overexpression of MMP-2, MMP-9 and collagen IV. Liver fibrosis was confirmed by severe histopathological changes. Pyridoxamine improved the assessed parameters. Moreover, histopathological and immunohistological studies supported the ability of pyridoxamine to reduce liver fibrosis. The findings of the present study provide evidence that pyridoxamine is a novel target for the treatment of liver fibrosis.

Application of adipose-derived stem cells in treating fibrosis

Fibrosis is the hyperactivation of fibroblasts that results in excessive accumulation of extracellular matrix, which is involved in numerous pathological changes and diseases. Adipose-derived stem cells (ASCs) are promising seed cells for regenerative medicine due to their bountiful source, low immunogenicity and lack of ethical issues. Their anti-fibrosis, immunomodulation, angiogenesis and other therapeutic effects have made them suitable for treating fibrosis-related diseases. Here, we review the literature on ASCs treating fibrosis, elaborate and discuss their mechanisms of action, changes in disease environment, ways to enhance therapeutic effects, as well as current preclinical and clinical studies, in order to provide a general picture of ASCs treating fibrotic diseases.

Potential of Mesenchymal Stem Cells in the Rejuvenation of the Aging Immune System

Rapid growth of the geriatric population has been made possible with advancements in pharmaceutical and health sciences. Hence, age-associated diseases are becoming more common. Aging encompasses deterioration of the immune system, known as immunosenescence. Dysregulation of the immune cell production, differentiation, and functioning lead to a chronic subclinical inflammatory state termed inflammaging. The hallmarks of the aging immune system are decreased naïve cells, increased memory cells, and increased serum levels of pro-inflammatory cytokines. Mesenchymal stem cell (MSC) transplantation is a promising solution to halt immunosenescence as the cells have excellent immunomodulatory functions and low immunogenicity. This review compiles the present knowledge of the causes and changes of the aging immune system and the potential of MSC transplantation as a regenerative therapy for immunosenescence.