Yohimbine ameliorates liver inflammation and fibrosis by regulating oxidative stress and Wnt/β-catenin pathway

Qiwei Jinggan Ling regulates oxidative stress and lipid metabolism in alcoholic liver disease by activating AMPK

BACKGROUND

Alcoholic liver disease (ALD) is a severe public health concern worldwide and there is still a lack of effective treatments. Qiwei Jinggan Ling (QJL) has protective effects against various liver injuries, but its pharmacological action on ALD has received little attention.

PURPOSE

To investigate the effect and mechanism of QJL on ALD in vivo and in vitro.

METHODS

In vivo, an ALD mouse model was established by alcohol combined with a high-fat diet (HFD) and treated with QJL. Biochemical indicators, HE staining, and Oil Red O staining were employed to assess hepatic oxidative stress, steatosis, and alcohol metabolism. RNA sequencing analysis was performed, and the results were verified by qRT-PCR and Western blot to elucidate the hepatoprotective mechanism of QJL. In vitro, HepG2 cells were co-stimulated with NaOA (sodium oleate) and EtOH (ethanol), followed by intervention with Compound C (CC, AMPK inhibitor) and QJL-containing serum. Oil Red O, BODIPY (boron-dipyrromethene), and ROS (reactive oxygen species) staining were applied to validate the efficacy and mechanism of QJL-containing serum. The expression of AMP-activated protein kinase (AMPK) pathway-related factors was analyzed through qRT-PCR and Western blot for additional corroboration. Moreover, the key pharmacodynamic components of QJL were identified by UPLC-MS/MS and molecular docking.

RESULTS

In vivo, QJL ameliorated liver structural disorders, steatosis, oxidative stress, and impaired alcohol metabolism, as indicated by biochemical indicators and histopathological assays. RNA sequencing analysis revealed that QJL reversed the expression of genes related to alcohol metabolism, fatty acid metabolism, and cholesterol metabolism. The results of qRT-PCR and Western blot were in line with those of RNA sequencing. Furthermore, it was discovered that QJL significantly upregulated the expression of p-AMPK and downregulated the expression of sterol regulatory element binding transcription factor 1 (SREBP-1c). In vitro, biochemical indicators and staining assays demonstrated that QJL-containing serum inhibited lipid accumulation and oxidative stress. The qRT-PCR and Western blot analysis revealed that QJL-containing serum markedly enhanced the expression of p-AMPK and carnitine palmitoyltransferase 1a (Cpt1a), while suppressing the expression of SREBP-1c, fatty acid synthase (Fasn), and acetyl-coenzyme A carboxylase 1 (ACC-1). However, CC inhibited the above pharmacological activities of QJL-containing serum. Additionally, (2S)-Liquiritigenin, Glycyrrhetinate, Isovitexin, Taxifolin, and Yohimbine were proved to be the key active components of QJL.

CONCLUSION

QJL had the potential to be a therapeutic drug for ALD by activating the AMPK pathway, thereby regulating lipid metabolism and inhibiting oxidative stress.

Signaling pathways that activate hepatic stellate cells during liver fibrosis

Liver fibrosis is a complex process driven by various factors and is a key feature of chronic liver diseases. Its essence is liver tissue remodeling caused by excessive accumulation of collagen and other extracellular matrix. Activation of hepatic stellate cells (HSCs), which are responsible for collagen production, plays a crucial role in promoting the progression of liver fibrosis. Abnormal expression of signaling pathways, such as the TGF-β/Smads pathway, contributes to HSCs activation. Recent studies have shed light on these pathways, providing valuable insights into the development of liver fibrosis. Here, we will review six signaling pathways such as TGF-β/Smads that have been studied more in recent years.

Yohimbine Treatment Alleviates Cardiac Inflammation/Injury and Improves Cardiac Hemodynamics by Modulating Pro-Inflammatory and Oxidative Stress Indicators

Acute myocarditis, also known as myocardial inflammation, is a self-limited condition caused by systemic infection with cardiotropic pathogens, primarily viruses, bacteria, or fungi. Despite significant research, inflammatory cardiomyopathy exacerbated by heart failure, arrhythmia, or left ventricular dysfunction and it has a dismal prognosis. In this study, we aimed to evaluate the therapeutic effect of yohimbine against lipopolysaccharide (LPS) induced myocarditis in rat model. The anti-inflammatory activity of yohimbine was assessed in in-vitro using RAW 264.7 and H9C2 cells. Myocarditis was induced in rats by injecting LPS (10 mg/kg), following the rats were treated with dexamethasone (2 mg/kg) or yohimbine (2.5, 5, and 10 mg/kg) for 12 h and their therapeutic activity was examined using various techniques. Yohimbine treatment significantly attenuated the LPS-mediated inflammatory markers expression in the in-vitro model. In-vivo studies proved that yohimbine treatment significantly reduced the LPS-induced increase of cardiac-specific markers, inflammatory cell counts, and pro-inflammatory markers expression compared to LPS-control samples. LPS administration considerably affected the ECG, RR, PR, QRS, QT, ST intervals, and hemodynamic parameters, and caused abnormal pathological parameters, in contrast, yohimbine treatment substantially improved the cardiac parameters, mitigated the apoptosis in myocardial cells and ameliorated the histopathological abnormalities that resulted in an improved survival rate. LPS-induced elevation of cardiac troponin-I, myeloperoxidase, CD-68, and neutrophil elastase levels were significantly attenuated upon yohimbine treatment. Further investigation showed that yohimbine exerts an anti-inflammatory effect partly by modulating the MAPK pathway. This study emphasizes yohimbine's therapeutic benefit against LPS-induced myocarditis and associated inflammatory markers response by regulating the MAPK pathway.

Structure-Based Drug Design of ADRA2A Antagonists Derived from Yohimbine

Yohimbine, a natural indole alkaloid and a nonselective adrenoceptor antagonist, possesses potential benefits in treating inflammatory disorders and sepsis. Nevertheless, its broader clinical use faces challenges due to its low receptor selectivity. A structure-activity relationship study of novel yohimbine analogues identified amino esters of yohimbic acid as potent and selective ADRA2A antagonists. Specifically, amino ester 4n, in comparison to yohimbine, showed a 6-fold higher ADRA1A/ADRA2A selectivity index (SI > 556 for 4n) and a 25-fold higher ADRA2B/ADRA2A selectivity index. Compound 4n also demonstrated high plasma and microsomal stability, moderate-to-low membrane permeability determining its limited ability to cross the blood-brain barrier, and negligible toxicity on nontumor normal human dermal fibroblasts. Compound 4n represents an important complementary pharmacological tool to study the involvement of adrenoceptor subtypes in pathophysiologic conditions such as inflammation and sepsis and a novel candidate for further preclinical development to treat ADRA2A-mediated pathologies.

MicroRNA-204-5p Ameliorates Renal Injury via Regulating Keap1/Nrf2 Pathway in Diabetic Kidney Disease

Background

Diabetic kidney disease (DKD) is characterized by renal fibrosis, and the pathogenesis of renal fibrosis is still not definitely confirmed. MiR-204-5p plays an important role in the regulation of fibrosis, autophagy and oxidative stress. In this study, we aimed to investigate the role of miR-204-5p on renal damage in diabetic kidneys and the underlying mechanisms involved.

Methods

In vivo, AAV-Ksp-miR-204-5p mimics were injected into mice via tail vein. In vitro, high glucose-induced HK-2 cells were treated with miR-204-5p inhibitor, miR-204-5p mimics, ATG5 siRNA, tertiary butyl hydroquinone (TBHQ), ML385, or 3-Methyladenine (3-MA). FISH and qRT-PCR were used to detect miR-204-5p expression. The expressions of protein and mRNA were detected by Western blotting, immunofluorescence, immunohistochemistry and qRT-PCR. The concentration of fibronectin in HK-2 cells culture medium was detected by ELISA.

Results

The expression of miR-204-5p in diabetic kidneys was significantly inhibited than that in control group. Delivering miR-204-5p mimics increased miR-204-5p expression, improved renal function, inhibited renal fibrosis and oxidative stress, and restored autophagy in db/db mice. In vitro, the expression of miR-204-5p was inhibited by HG treatment in HK-2 cells. MiR-204-5p mimics effectively increased miR-204-5p expression and reduced fibronectin and collagen I expression, restored autophagy dysfunction, and increased Nrf2 expression, whereas these alterations were abrogated by Nrf2 inhibitor ML385, autophagy inhibitor 3-methyladenine (3-MA, 5 mM) treatment or ATG5 siRNA transfection in HG-induced HK-2 cells. In addition, miR-204-5p inhibitor significantly inhibited miR-204-5p expression and aggravated HG-induced fibronectin and collagen I expression, autophagy dysfunction, and decreased Nrf2 expression, while these alterations were abolished by Nrf2 activator TBHQ. Furthermore, the binding of miR-204-5p with Keap1 was confirmed by luciferase reporter assay and miR-204-5p negatively regulated Keap1 expression, resulting in the activation of Nrf2 pathway.

Conclusion

MicroRNA-204-5p protects against the progression of diabetic renal fibrosis by restoring autophagy via regulating Keap1/Nrf2 pathway.