Total flavonoids from Smilax glabra Roxb blocks epithelial‐mesenchymal transition and inhibits renal interstitial fibrosis by targeting miR‐21/PTEN signaling

Abstract

Background: Smilax glabra Roxb, a traditional Chinese herb, has been widely used in folk medicine. The current study was performed to investigate the protective effect of S. glabra Roxb extract, pure total flavonoids from Smilax glabra Roxb (PTFS), on renal interstitial fibrosis (RIF) and its underlying mechanism.Methods: First, a surgical model of unilateral ureteral obstruction was established in rats to induce RIF. Then, rats were grouped and treated with PTFS at different concentration. Second, HK-2 cells underwent an epithelial-mesenchymal transition (EMT) by the addition of transforming growth factor-β1 (TGF-β1). Additionally, HK-2 cells after inducing for EMT were transfected with microRNA-21 (miR-21) mimic or inhibitor. These HK-2 cells were grouped and treated with PTFS at different concentration. Finally, real-time polymerase chain reaction and Western blot analysis were performed to detect the expression of possible signaling factor involved in RIF in renal tissues or HK-2 cells after PTFS treatment. Results: In vivo and in vitro experiments indicated that PTFS treatment could decrease the expression of α-smooth muscle actin (α-SMA; mesenchymal marker) and increase the expression of E-cadherin (epithelial marker) in both messenger RNA and protein level. Moreover, PTFS also attenuated the expression of TGF-β1/Smad signaling in both renal tissues and HK-2 cells that underwent EMT. Overexpression or inhibition of miR-21 in HK-2 cells activated or blocked the PI3K/Akt signaling via targeting phosphatase and tension homolog (PTEN), and then promoted or suppressed the progress of TGF-β1-induced EMT by regulating the expression of α-SMA and E-cadherin. Furthermore, PTFS treatment inhibited TGF-β1-induced EMT progress by blocking miR-21/PTEN/PI3K/Akt signaling.Conclusion: PTFS has strong anti-EMT and antifibrosis effects both in vitro and in vivo. The mechanism underlying these effects may be related to inhibition of TGF-β1/Smad, and their downstream miR-21/PTEN signaling, leading to blocks of EMT process during RIF.

miR-21 promotes bevacizumab induced epithelial-mesenchymal transition in retinal pigment epithelial cells by regulating Snail expression via TGFβ1/smad2/3 signaling pathway

“…Gain-and loss-offunction studies revealed that miR-21 positively regulated BEV-induced EMT by decreasing the expression of E-cadherin and increasing the expression of α-SMA. Many researches about the relationship of miR-21 and EMT in other tissues[21][22][23]32] are consistent with our results, which further prove our conclusion. However, miR-21-5p were downregulated in TGFβ2-induced EMT in human RPE cells[31].…”

“…Usui-Ouchi A et al found that upregulation of miR-21 levels in the vitreous humor is associated with development of proliferative vitreoretinal disease by promoted cell proliferation and migration in RPE cells [20]. Many studies in other organs have shown that miR-21 is involved in the EMT of cells [21][22][23][24]. Snail is a zincfinger transcription factor and one of the best-known functions of Snail is to regulate EMT during tumorigenesis and fibrosis.…”

miR‑21/PTEN pathway mediates the cardioprotection of geniposide against oxidized low‑density�lipoprotein‑induced endothelial injury via suppressing oxidative stress and inflammatory response

“…3A). Studies have revealed that PTEN is the negatively regulated target of miR-21 (31,32). Western blot analysis revealed that the miR-21 mimic led to a significant downregulation of PTEN expression, whereas the miR-21 inhibitor led to a significant upregulation of PTEN expression ( Fig.…”

Protective Effects of Smilax glabra Roxb. Against Lead-Induced Renal Oxidative Stress, Inflammation and Apoptosis in Weaning Rats and HEK-293 Cells

“…The main compounds in S. glabra extract are flavonoids; the content is ~687 mg rutin equivalents/g dry extract. Pure total flavonoids from S. glabra Roxb have affects against renal fibrosis and epithelial-mesenchymal transition in vitro and in vivo ( Luo et al., 2019 ). The n-butyl alcohol fraction of S. glabra extract has been shown to inhibit the swelling rate of paws and levels of IL-1β, IL-6 and TNF-α in carrageenan-induced arthritic rats ( Bao et al., 2018 ).…”