Deficiency of Cathelicidin Attenuates High-Fat Diet Plus Alcohol-Induced Liver Injury through FGF21/Adiponectin Regulation

Chrysanthemum morifolium attenuates metabolic and alcohol-associated liver disease via gut microbiota and PPARα/γ activation

BACKGROUND

Metabolic and alcohol-associated liver disease (MetALD) shows a high prevalence rate in liver patients, but there is currently no effective treatment for MetALD. As a typical edible traditional Chinese medicinal herb, the anti-inflammatory, antioxidant, and hepatoprotective properties of water extract of Chrysanthemum morifolium Ramat. (WECM) has been demonstrated. However, its therapeutic effect on MetALD and the associated mechanisms remain unclear.

PURPOSE

To investigate the underlying mechanisms of WECM against MetALD.

METHODS

We constructed a MetALD rat model following a high-fat & high-sucrose plus alcohol diet (HFHSAD). MetALD rats were treated with WECM at 2.1, 4.2, and 8.4 g/kg/d for six weeks. Efficacy was determined, and pathways associated with WECM against MetALD were predicted through serum and hepatic biochemical marker measurement, histopathological section analysis, 16S rDNA sequencing of the gut microbiota and untargeted serum metabolomics analyses. Changes in genes and proteins in the peroxisome proliferator-activated receptor alpha (PPARα) and gamma (PPARγ) signaling pathways were detected by RT‒PCR and Western blotting.

RESULTS

WECM treatment significantly attenuated hepatic steatosis, hyperlipidemia and markers of liver injury in MetALD rats. Moreover, WECM improved vascular endothelial function, hypertension, and systematic oxidative stress. Mechanistically, WECM treatment altered the overall structure of the gut microbiota through maintaining Firmicutes/Bacteroidota ratio and reducing harmful bacterial abundances such as Clostridium, Faecalibaculum, and Herminiimonas. Notably, WECM promoted 15-deoxy-△12, 14-prostaglandin J2 (15d-PGJ2) release and further activated the PPARγ to reduce serum TNF-α, IL-1β, and IL-6 levels. Additionally, WECM upregulated PPARα and downregulated the levels of CD36 and FABP4 to improve lipid metabolism.

CONCLUSION

Our findings provide the first evidence that WECM treatment significantly improved hepatic steatosis, oxidative stress and inflammation in MetALD rats by regulating the gut microbiota and activating the 15d-PGJ2/PPARγ and PPARα signaling pathway.

Fibroblast growth factor 21: An emerging pleiotropic regulator of lipid metabolism and the metabolic network

Fibroblast growth factor 21 (FGF21) was originally identified as an important metabolic regulator which plays a crucial physiological role in regulating a variety of metabolic parameters through the metabolic network. As a novel multifunctional endocrine growth factor, the role of FGF21 in the metabolic network warrants extensive exploration. This insight was obtained from the observation that the FGF21-dependent mechanism that regulates lipid metabolism, glycogen transformation, and biological effectiveness occurs through the coordinated participation of the liver, adipose tissue, central nervous system, and sympathetic nerves. This review focuses on the role of FGF21-uncoupling protein 1 (UCP1) signaling in lipid metabolism and how FGF21 alleviates non-alcoholic fatty liver disease (NAFLD). Additionally, this review reveals the mechanism by which FGF21 governs glucolipid metabolism. Recent research on the role of FGF21 in the metabolic network has mostly focused on the crucial pathway of glucolipid metabolism. FGF21 has been shown to have multiple regulatory roles in the metabolic network. Since an adequate understanding of the concrete regulatory pathways of FGF21 in the metabolic network has not been attained, this review sheds new light on the metabolic mechanisms of FGF21, explores how FGF21 engages different tissues and organs, and lays a theoretical foundation for future in-depth research on FGF21-targeted treatment of metabolic diseases.

Bo's abdominal acupuncture improves disordered metabolism in obese type 2 diabetic rats through regulating fibroblast growth factor 21 and its related adipokines

OBJECTIVE

To investigate the effect of Bo's abdominal acupuncture (BOAA) on fibroblast growth factor 21 (FGF21) and its related adipokines in type 2 diabetes mellitus (T2DM) rats.

METHODS

This study established obese T2DM rat model by high-fat diet (HFD) with a dose of streptozotocin (STZ, 30 mg/kg). Obese T2DM rats were randomly subdivided into four groups (n = 10): negative, BOAA, conventional acupuncture (COA group) and metformin group (Met group) groups. The biochemical parameters, mRNAs, and proteins were analyzed using enzyme-lined immunoassays kits, quantitative polymerase chain reaction and Western blot.

RESULTS

Treatment with BOAA attenuated the histopathological changes in visceral fat and restored the alterations in the levels of body weight, fasting blood glucose (FBG), homeostasis model assessment for insulin resistance (HOMA-IR). BOAA treatment significantly decreased the levels of triglyceride, total cholesterol, low density lipoprotein cholesterol, leptin, and increased the serum levels of high-density lipoprotein cholesterol, fibroblast growth factor 21 (FGF21), adiponectin (ADP), peroxisome proliferator-activated receptor γ (PPAR-γ), C-peptide (C-P) in obese T2DM rats. Furthermore, BOAA treatment significantly increased the mRNA expressions of FGF21, ADP, leptin, PPAR-γ, PPAR-α and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Besides, BOAA treatment upregulated the protein expressions of fibroblast growth factor receptors3 (FGFR3), PPAR-α, extracellular signal-regulated kinase (ERK), phosphorylated ERK (p-ERK), AMPK, p-AMPK, Liver kinase B1 (LKB1), phosphorylated LKB1 (p-LKB1), acetyl-CoA carboxylase (ACC) and phosphorylated ACC (p-ACC), while downregulated the protein expressions of FGF21 and PPAR-γ in visceral fat.

CONCLUSIONS

BOAA treatment reduced FBG and body weight, and improved insulin sensitivity through regulating FGF21 signaling pathway and its related adipokine in obese T2DM rats.

Cardiac Hepatopathy: New Perspectives on Old Problems through a Prism of Endogenous Metabolic Regulations by Hepatokines

Cardiac hepatopathy refers to acute or chronic liver damage caused by cardiac dysfunction in the absence of any other possible causative reasons of liver injury. There is a large number of evidence of the fact that cardiac hepatopathy is associated with poor clinical outcomes in patients with acute or actually decompensated heart failure (HF). However, the currently dominated pathophysiological background does not explain a role of metabolic regulative proteins secreted by hepatocytes in progression of HF, including adverse cardiac remodeling, kidney injury, skeletal muscle dysfunction, osteopenia, sarcopenia and cardiac cachexia. The aim of this narrative review was to accumulate knowledge of hepatokines (adropin; fetuin-A, selenoprotein P, fibroblast growth factor-21, and alpha-1-microglobulin) as adaptive regulators of metabolic homeostasis in patients with HF. It is suggested that hepatokines play a crucial, causative role in inter-organ interactions and mediate tissue protective effects counteracting oxidative stress, inflammation, mitochondrial dysfunction, apoptosis and necrosis. The discriminative potencies of hepatokines for HF and damage of target organs in patients with known HF is under on-going scientific discussion and requires more investigations in the future.

Advancements in the Alcohol-Associated Liver Disease Model

Alcohol-associated liver disease (ALD) is an intricate disease that results in a broad spectrum of liver damage. The presentation of ALD can include simple steatosis, steatohepatitis, liver fibrosis, cirrhosis, and even hepatocellular carcinoma (HCC). Effective prevention and treatment strategies are urgently required for ALD patients. In previous decades, numerous rodent models were established to investigate the mechanisms of alcohol-associated liver disease and explore therapeutic targets. This review provides a summary of the latest developments in rodent models, including those that involve EtOH administration, which will help us to understand the characteristics and causes of ALD at different stages. In addition, we discuss the pathogenesis of ALD and summarize the existing in vitro models. We analyse the pros and cons of these models and their translational relevance and summarize the insights that have been gained regarding the mechanisms of alcoholic liver injury.