Xanthohumol Inhibits TGF-β1-Induced Cardiac Fibroblasts Activation via Mediating PTEN/Akt/mTOR Signaling Pathway

Abstract

Background

Xanthohumol (Xn) is the most abundant prenylated flavonoid in Hops (Humulus lupulus L.), and exhibits a range of pharmacological activities. This study aimed to investigate the effect of Xn on TGF-β1-induced cardiac fibroblasts activation and elucidate the underlying mechanism.

Materials and Methods

The cellTiter 96^® AQueous one solution cell proliferation assay kit was adopted to determine the cell viability of cardiac fibroblasts, and the proliferation was detected through 5-ethynyl-2ʹ-deoxyuridine (EdU) incorporation assay. The α-SMA protein expression was measured by using immunofluorescence and Western blotting. Western blotting was conducted to test the protein expressions of collagen I and III, PTEN, p-Akt, Akt, p-mTOR, mTOR, p-Smad3, Smad3 and GAPDH. The mRNA levels of α-SMA, collagen I and III were determined by quantitative real-time polymerase chain reaction (PCR).

Results

Xn inhibited the TGF-β1-induced proliferation, differentiation and collagen overproduction of cardiac fibroblasts. TGF-β1 induced the down-regulated PTEN expression, Akt and mTOR phosphorylation. These effects of TGF-β1 were suppressed by Xn, while blocking of PTEN reduced Xn-mediated inhibitory effect on cardiac fibroblasts activation induced by TGF-β1.

Conclusion

Xn inhibits TGF-β1-induced cardiac fibroblasts activation via mediating PTEN/Akt/mTOR signaling pathway.

Keywords:

• xanthohumol; Xn
• cardiac fibrosis
• cardiac fibroblasts
• TGF-β1
• PTEN/AKT/mTOR pathway

Acknowledgments

This study was supported by grants of the National Natural Scientific Foundation of China (No. 81703518, 81673614, 81973406, 81701577), Hunan Provincial Natural Scientific Foundation (No. 2018JJ3571, 2019JJ50849, 2020JJ4823, 2020JJ8064), Scientific Research Project of Hunan Provincial Health and Family Planning Commission (No. B20180253, B2019089), and Fundamental Research Funds for the Central Universities of Central South University (No. 2020zzts822).

Ethics Approval

The animals were treated and cared for in accordance with the National Institutes of Health Guide (NIH publications № 8023). These animals were purchased from Laboratory Animal Center, Xiangya School of Medicine, Central South University (Changsha, China), and approved by the Medicine Animal Welfare Committee of Xiangya School of Medicine (Ref No. SYXK-2015/0017).

Disclosure

The authors declare no conflicts of interest.