scholarly journals Astragaloside IV attenuated TGF-β1- induced epithelial-mesenchymal transition of renal tubular epithelial cells via connexin43 and Akt/mTOR signaling pathway

Author(s):  
Yonghong Lian ◽  
Cuiqiong Li ◽  
Jianchun Li ◽  
Yongxiang Xie ◽  
Qiancheng Liu ◽  
...  

Abstract INTRODUCTION: The objective of the study was to observe whether Cx43 could regulate EMT of RTECs by influencing Akt/mTOR signaling pathway, and whether ASV could inhibit the development of renal interstitial fibrosis by regulating Cx43. METHODS: Lentivirus infection was transfected into RTECs with the final concentration of 50×PFU/ cell to regulate the expression of Cx43.And RTECs were intervened by different doses of ASV. After synchronous culture of RTECs in each group,cell morphological changes were observed and the expression levels of EMT-related indicators, and the expression levels of Cx43, the protein expressions and phosphorylation levels AKT and mTOR in different groups were detected by WB. RESULTS: When the expression of Cx43 in RTECs was regulated by lentivirus infection, the degree of EMT induced by TGF‑β1 and the phosphorylation level of Akt and mTOR were changed accordingly, indicating that Akt/mTOR pathway might be a downstream molecular mechanism by which Cx43 could regulate EMT. After intervention with different doses of ASV, the expression level of Cx43 increased with obvious concentration dependence, and the expression levels of p-Akt and p- mTOR were significantly altered, suggesting that ASV could effectively increase the protein expressions of TGF‑β1-induced Cx43 in RTECs and inhibit the phosphorylation levels of Akt and mTOR. CONCLUSION: Cx43 is the main material basis of RTECs’injury, and ASV could inhibit TGF-β1 induced RTECs transdifferentiation. In-depth study of the mechanism may provide a broad application prospect for the treatment of renal interstitial fibrosis.

Author(s):  
Liming Guo ◽  
Kuibi Tan ◽  
Qun Luo ◽  
Xu Bai

Diabetic nephropathy (DN) is the most common complication of diabetes and is prone to kidney failure. Dihydromyricetin (DHM) has been reported to have a variety of pharmacological activities. This study aims to explore the effect of DHM on DN and the underlying molecular mechanism. An in vivo DN rat model was established. The degree of renal interstitial fibrosis (RIF) was detected by hematoxylin-eosin (HE) staining, Masson's trichrome staining, and immunohistochemistry (IHC). In vitro, NRK-52E cells were divided into four groups: normal glucose (NG), high glucose (HG), HG+DHM, and HG+rapamycin (autophagy inhibitor). The levels of autophagy- and fibrosis-related proteins were analyzed by western blotting. The expression of miR-155-5p and phosphatase and tensin homolog deleted on chromosome ten (PTEN) and their relationship were assessed by quantitative reverse transcription (qRT)-PCR and dual luciferase reporter gene assay. Our results showed that RIF was increased in DN rat model and in HG-induced NRK-52E cells. DHM treatment attenuated the increased RIF and also increased autophagy. MiR-155-5p expression was increased, while PTEN expression was decreased in DN rat and cell model, and DHM reversed both effects. Dual luciferase assay showed that PTEN was the target gene of miR-155-5p. DHM inhibited HG-induced fibrosis and promoted autophagy by inhibiting miR-155-5p expression in NRK-52E cells. In addition, DHM promoted autophagy by inhibiting the PI3K/AKT/mTOR signaling pathway. In conclusion, DHM promotes autophagy and attenuates RIF by regulating the miR-155-5p/PTEN signaling and PI3K/AKT/mTOR signaling pathway in DN.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769756 ◽  
Author(s):  
Hui Shi ◽  
Jin Pu ◽  
Xiao-Li Zhou ◽  
Yun-Ye Ning ◽  
Chong Bai

This study aimed to investigate the effects of long non-coding RNA ROR (regulator of reprogramming) on cisplatin (DDP) resistance in patients with non-small-cell lung cancer by regulating PI3K/Akt/mTOR signaling pathway. Human cisplatin-resistant A549/DDP cell lines were selected and divided into control group, negative control group, si-ROR group, ROR over-expression group, Wortmannin group, and ROR over-expression + Wortmannin group. MTT assay was used to determine the optimum inhibitory concentration of DDP. Quantitative real-time polymerase chain reaction and western blotting were applied to detect expressions of long non-coding RNA ROR, PI3K, Akt, and mTOR. Colony-forming assay, scratch test, Transwell assay, and flow cytometry were conducted to detect cell proliferation, migration, invasion, and apoptosis, respectively. Tumor-formation assay was performed to detect the growth of transplanted tumors. Long non-coding RNA ROR expression was high in human A549/DDP cell lines. Compared with the control and negative control groups, the mRNA and protein expressions of PI3K, Akt, mTOR, and bcl-2 decreased, whereas the mRNA and protein expression of bax and the sensitivity of cells to DDP significantly increased. Cell proliferation, migration, and invasion abilities decreased in the si-ROR and Wortmannin groups. In comparison with control and negative control groups, the mRNA and protein expressions of PI3K, Akt, mTOR, and bcl-2 increased, whereas the mRNA and protein expressions of bax decreased, the sensitivity of cells to DDP significantly increased, and cell proliferation, migration, and invasion abilities decreased in the ROR over-expression group. For nude mice in tumor-formation assay, compared with control and negative control groups, the tumor weight was found to be lighter (1.03 ± 0.15) g, the protein expressions of PI3K, Akt, mTOR, and bcl-2 decreased, and the protein expression of bax increased in the si-ROR group. Long non-coding RNA ROR may affect the sensitivity of lung adenocarcinoma cells to DDP by targeting PI3K/Akt/mTOR signaling pathway.


Author(s):  
Dongmei Zhan ◽  
Tengyang Ni ◽  
Haibo Wang ◽  
Mengying Lv ◽  
Masataka Sunagawa ◽  
...  

Background: This study aimed to determine the effect and mechanism of Celastrol inhibiting the proliferation and decreases drug resistance of cisplatin-resistant gastric cancer cells. Objective: To explore the effect and mechanism of Celastrol on proliferation and drug resistance of human gastric cancer cisplatin-resistant cells SGC7901/DDP. Methods: The thiazole blue (MTT) method was used to detect the sensitivity of human gastric cancer cisplatin-resistant cells SGC7901/DPP to cisplatin and Celastrol to determine the Drug resistance index (DRI). According to the half inhibitory concentration (IC50) value, the action concentration of the following experimental drugs was set to reduce the cytotoxicity; Annexin V-FITC/PI double staining method was used to detect the apoptosis of SGC7901/DDP cells induced by Celastrol; Western Blot was used to examine the expression levels of P-glycoprotein (P-gp), Multidrug Resistance Associated Protein 1 (MRP1), Breast Cancer Resistance Associated Protein (Breast Cancer Resistance)-relative protein (BCRP), and mechanistic Target of Rapamycin (mTOR) pathway related proteins; Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the mRNA expression levels of P-gp, MRP1, and BCRP. Results: (1) Compared with the control group (We set the untreated group as the control group), the proliferation of the SGC7901/DPP cells was significantly inhibited after treating with 0.1-6.4μmol/L Celastrol in a time- and concentration-dependent manner (P<0.05). The Drug resistance index DRI of the SGC7901/DPP cells to DDP was 5.64. (2) Compared with the control group, Celastrol could significantly inhibit the proliferation and induce the apoptosis of the SGC7901/DPP cells (P<0.05). (3) The mRNA and protein expression levels of P-gp, MRP1, and BCRP in the SGC7901/DPP cells were significantly higher than those in the SGC7901 cells. However, after treating with Celastrol, the expression levels of P-gp, MRP1, and BCRP in the SGC7901/DPP cells were significantly reduced (P<0.05). (4) Compared with the control group, the Celastrol treatment also reduced the expression of the mTOR signaling pathway related proteins, suggesting that the mTOR signaling pathway may be involved in the process of Celastrol inhibiting the proliferation of the SGC7901/DDP cells and reducing their drug resistance. (5) Significantly, the combination of Celastrol and DDP reduced the expression of P-gp, MRP1, and BCRP in the SGC7901/DPP cells. Conclusion: Celastrol can inhibit the proliferation of the SGC7901/DDP cells, induce their apoptosis, and reduce the expression of drug resistance genes, probably by inhibiting the expression of the proteins related to the mTOR signaling pathway.


2021 ◽  
Author(s):  
Huanfang Fan ◽  
Dehui Li ◽  
Na Guo ◽  
Chunxia Sun ◽  
Jingfei Dong ◽  
...  

Abstract Objective. To study the inhibitory effect of Xihuang Pill on the development of DMBA combined estrogen and progesterone induced breast precancerous lesions rats by PI3K/AKT/mTOR signaling pathway, and to explore the effect of Xihuang Pill in preventing and treating breast cancer. Method. Establishment of a rat model of breast precancerous lesion with DMBA combined estrogen and progesterone sequential induction for 10 weeks. Xihuang Pill was administered by gavage continuously for 4 weeks. Take rat breast tissue and stain with hematoxylin- eosin (HE). The pathomorphological changes were observed with light microscope; TUNEL staining to detect cell apoptosis in breast tissue; Western blot was used to detect the protein expression of P-PI3K, P-AKT (S473), P-AKT (T308), PTEN, P-Tuberin/TSC2, P-Tuberin (p-S939), p-mTOR, P-4E-BP1 in breast tissues. The qRT-PCR was used to detect the gene expression of PTEN mRNA and VEGF mRNA. Immunohistochemistry was used to detect the protein expression of P-S6, p-p70s6k and VEGF. Result. Compared with the disease model group, the low, middle and high dose Xihuang Pill groups could significantly reduce the degree of breast pathology, and the number of apoptosis of breast precancerous lesions cells increased with the increase of Xihuang Pill dose; The expression levels of P-PI3K, P-AKT (S473), P-AKT (T308), p-mTOR, P-4E-BP1, p-S6, p-p70S6K, VEGF protein and VEGF mRNA dropped with the increase of Xihuang Pill dose. The expression levels of PTEN, P-Tuberin/TSC2, P-Tuberin (p-S939) protein and PTEN mRNA elevated with the increase of Xihuang Pill dose. Conclusion. Xihuang Pill can promote the apoptosis of breast precancerous lesion cells and reduce the proliferation of vascular endothelial cells, and then inhibit the progression of breast precancerous lesions. Its mechanism probably associated with the regulation of PI3K/AKT/mTOR pathway related gene protein expression.


2019 ◽  
Vol 47 (11) ◽  
pp. 5787-5801
Author(s):  
Yun Xiao ◽  
Zhiwei Zhang ◽  
Yingyu Fu ◽  
Huizhi Shan ◽  
Sini Cui ◽  
...  

Objective To evaluate the effect of GSTA3 within the PI3K–Keap1/Nrf2 pathway in renal interstitial fibrosis (RIF). Methods An in vitro RIF model with TGF-β1 stimulation in NRK-52E cells was established to identify potential signaling pathways that modulate GSTA3. Changes in GSTA3 expression were observed in the RIF model after silencing or enhancing Nrf2 expression. Changes in GSTA3, Keap1, and Nrf2 expression were detected after blocking the upstream of the Keap1/Nrf2 signaling pathway (including MAPK and PI3K/Akt). The effect of Nrf2 on GSTA3 expression was evaluated by overexpressing Nrf2. Results Protein and mRNA levels of GSTA3, FN, Nrf2, and Keap1 were significantly increased after TGF-β1 stimulation. GSTA3 was also upregulated following overexpression of Nrf2. TGF-β1 activated the PI3K/Akt signaling pathway, leading to RIF. After blocking this pathway, the production of superoxide dismutase, reactive oxygen species, and fibronectin were reduced. The MAPK pathway was not involved in the development of RIF via regulating GSTA3 expression. Conclusions The PI3K–KEAP1/Nrf2–GSTA3 signaling pathway is a possible mechanism of resisting external stimulation of renal fibrosis factors, regulating oxidative stress, and preventing RIF.


2021 ◽  
Author(s):  
De-hui Li ◽  
Huan-fang Fan ◽  
Na Guo ◽  
Chun-xia Sun ◽  
Jing-fei Dong ◽  
...  

Abstract Background:To study the inhibitory effect of Xihuang pill on the development of DMBA combined with oestrogen- and progesterone-induced breast precancerous lesions in rats by the PI3K/AKT/mTOR signaling pathway and to explore the effect of Xihuang pill in preventing and treating breast cancer. Method: Establishment of a rat model of precancerous breast lesions with DMBA combined with oestrogen and progesterone sequential induction for 10 weeks. Xihuang pill was administered continuously by gavage for 4 weeks. Rat breast tissue was stained with haematoxylin-eosin (HE). The pathomorphological changes were observed with a light microscope. TUNEL staining was used to detect cell apoptosis in breast tissue. Western blotting was used to detect the protein expression of P-PI3K, P-AKT (S473), P-AKT (T308), PTEN, P-tuberin/TSC2, P-tuberin (p-S939), p-mTOR, and P-4E-BP1 in breast tissues. qRT-PCR was used to detect the gene expression of PTEN mRNA and VEGF mRNA. Immunohistochemistry was used to detect the protein expression of P-S6, p-p70s6k and VEGF.Result:Compared with the disease model group, the low-, middle- and high-dose Xihuang pill groups could significantly reduce the degree of breast pathology, and the number of apoptotic precancerous breast lesion cells increased with increasing Xihuang pill dose. The expression levels of P-PI3K, P-AKT (S473), P-AKT (T308), p-mTOR, P-4E-BP1, p-S6, p-p70S6K, VEGF protein and VEGF mRNA dropped with increasing Xihuang pill dose. The expression levels of PTEN, P-tuberin/TSC2, P-tuberin (p-S939) protein and PTEN mRNA increased with increasing Xihuang pill dose. Conclusion:Xihuang pill can promote the apoptosis of precancerous breast lesion cells, reduce the proliferation of vascular endothelial cells, and then inhibit the progression of precancerous breast lesions. Its mechanism is probably associated with the regulation of the PI3K/AKT/mTOR pathway related protein expression.


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