Forsythiaside A suppresses renal fibrosis and partial epithelial-mesenchymal transition by targeting THBS1 through the PI3K/AKT signaling pathway.

Renal fibrosis is a key feature of chronic kidney disease (CKD) progression, whereas no proven effective anti-fibrotic treatments. Forsythiaside A (FTA), derived from Forsythia suspense, has been found to possess nephroprotective properties. However, there is limited research on its anti-fibrotic effects, and its mechanism of action remains unknown. This study aimed to investigate the suppressive effects of FTA on renal fibrosis and explore the underlying mechanisms. In vitro, we established a HK2 cell model induced by transforming growth factor β1 (TGF-β1), and in vivo, we used a mice model induced by unilateral ureteral obstruction (UUO). CCK-8 assay, qRT-PCR, Western blotting, immunofluorescence, flow cytometry, histological staining, immunohistochemistry, TUNEL assay, RNA transcriptome sequencing, and molecular docking were performed. The results showed that FTA (40 μM or 80 μM) treatment improved cell viability and suppressed TGF-β1-induced fibrotic changes and partial epithelial-mesenchymal transition (EMT). Furthermore, FTA treatment reversed the activation of the PI3K/AKT signaling pathway, and THBS1 was identified as the target gene. We found that THBS1 knockdown suppressed the activation of the PI3K/AKT signaling pathway and reduced the fibrosis and partial EMT-related protein level. Conversely, THBS1 overexpression activated the PI3K/AKT signaling pathway and exacerbated renal fibrosis and partial EMT. In vivo, mice were administered FTA (30 or 60 mg/kg) for 2 weeks, and the results demonstrated that FTA administration significantly mitigated tubular injury, tubulointerstitial fibrosis, partial EMT, and apoptosis. In conclusion, FTA inhibited renal fibrosis and partial EMT by targeting THBS1 and inhibiting activation of the PI3K/AKT pathway.

Tuoheti K ，Bai X ，Yang L ，Wang X ，Cao Y ，Yisha Z ，Guo L ，Zhan S ，Wu Z ，Liu T ... -  《-》

Hydroxychloroquine alleviates renal interstitial fibrosis by inhibiting the PI3K/Akt signaling pathway.

Renal fibrosis is the ultimate presentation of chronic kidney disease, which progresses to end-stage renal disease. Hydroxychloroquine (HCQ) has been adapted for the treatment of autoimmune diseases; however, the potential mechanism underlying the role of HCQ in renal fibrosis remains unclear. C57BL/6 J mice were randomly divided into three groups (sham group, UUO group, and UUO + HCQ group (20 mg/kg)). HE and Masson staining were performed to assess kidney tissue damage and fibrosis, and western blotting was performed to assess the expression of epithelial-mesenchymal transition (EMT), extracellular matrix (ECM), PI3K/AKT, and NF-κB-related proteins. PCR and TUNEL were adopted to detect inflammatory factors and cell apoptosis. HK-2 cells treated with TGF-β1 were used for the in vitro experiments. HCQ may potentially have therapeutic effects on renal fibrosis mediated through 122 target genes, and the Kyoto Encyclopedia of Genes and Genomes pathways of these genes were enriched for PI3K/AKT signaling based on network pharmacology. UUO mice that received HCQ demonstrated significantly less tubular damage than the UUO mice. HCQ treatment additionally blunted EMT in UUO kidneys and TGF-β1-treated renal tubular epithelial cells, and alleviated ECM deposition in kidney tissue. Furthermore, HCQ treatment reduced UUO-induced inflammation and apoptosis. Mechanistically, HCQ treatment suppressed the activation of the PI3K/Akt and NF-kB pathways. This study demonstrated that HCQ ameliorated renal fibrosis by inhibiting the PI3K/AKT and NF-κB signaling pathways to attenuate inflammatory factors and the apoptotic function of renal tubular epithelial cells, thus providing renewed theoretical evidence for HCQ treatment of renal fibrosis.

Li D ，Yu K ，Feng F ，Zhang Y ，Bai F ，Zhang Y ，Sun N ，Fan J ，Liu L ，Yang H ，Yang X ... -  《-》

Hyperforin regulates renal fibrosis via targeting the PI3K-AKT/ICAM1 axis.

To explore the role and mechanism of hyperforin (one of the active components of Sophora flavescens) in renal fibrosis. The active compounds and target proteins of Sophora flavescens were first screened through TCMSP (https://tcmsp-e.com/). The renal fibrosis-related genes were analyzed through GeneCards (https://www.genecards.org/). The differentially expressed genes (DEGs) in renal fibrosis in GEO dataset GSE156181 were obtained. Metascape was applied for target protein enrichment analysis. TGF-β1-stimulated renal tubular epithelial cells were used for renal fibrosis cell model establishment. The unilateral ureteral obstruction (UUO) mouse model was used for the renal fibrosis in vivo model. Cell viability was detected using an MTT assay. Immunofluorescence staining was employed to detect cell morphology changes and the expression of α-SMA and collagen I. Hematoxylin and eosin (H&E) and Masson staining were employed to determine the renal morphologic change. qRT-PCR or Western blotting was applied to determine the expression levels of the target proteins. After intersecting the analysis results of TCMSP, GeneCards, and dataset GSE156181, hyperforin targeting ICAM1 was identified. Metascape pathway enrichment analysis results revealed that the effective compounds of Sophora flavescens were tightly associated with extracellular matrix (ECM) remodeling and inflammatory response. MTT assay demonstrated that hyperforin had no toxic effect on cells. Immunofluorescence staining results evidenced that hyperforin could partially restore TGF-β1-induced epithelial-mesenchymal transition (EMT), the PI3K/AKT pathway activation, and ICAM1 upregulation, and these effects of hyperforin could be reversed by ICAM1 overexpression. While the PI3K/AKT pathway activator IGF-1 effectively reversed the EMT inhibition effect of hyperforin on renal tubular epithelial cells. Moreover, the UUO mouse model further confirmed that hyperforin reduced renal fibrosis. Hyperforin inhibited renal fibrosis via the PI3K/AKT/ICAM1 axis.

Yang S ，Zhong S ，Deng Z ，Xie T ，Yin G ，Wang L ，Liu J ，Yang J ，Long Z ，Jiang X ，Tan J ... -  《-》

DNMT3a negatively regulates PTEN to activate the PI3K/AKT pathway to aggravate renal fibrosis.

Hu T ，Chen F ，Chen D ，Liang H ... -  《-》

Nrf2 signaling attenuates epithelial-to-mesenchymal transition and renal interstitial fibrosis via PI3K/Akt signaling pathways.

Nrf2 constitutes a therapeutic reference point for renal fibrosis and chronic kidney diseases. Nrf2-related signaling pathways are recognized to temper endothelial-to-mesenchymal transition (EMT) in fibrotic tissue. Nevertheless, the mechanism by which Nrf2 mitigates renal interstitial fibrosis is imprecise. The relationship between Nrf2 and renal interstitial fibrosis was investigated using the unilateral ureteral obstruction (UUO) model of Nrf2-/- mice. The mice were separated into four groups, based on the treatment and intervention: Nrf2-/- + UUO, Nrf2-/- + Sham, WT + UUO and WT + Sham. Histological examination of renal tissue following the hematoxylin-eosin and Masson staining was carried out, as well as immunohistochemical staining. Additionally, to confirm the in vivo discoveries, in vitro experiments with HK-2 cells were also performed. The Nrf2-/- + UUO group showed more severe renal interstitial fibrosis compared to the WT + UUO, Nrf2-/- + Sham and WT + Sham groups. Furthermore, the manifestations of α-SMA and Fibronectin significantly increased, and the manifestation of E-cadherin considerably decreased in kidney tissues from the group of Nrf2-/- + UUO, compared to the WT + UUO group. The Nrf2 protein level significantly decreased in HK-2 cells, in reaction to the TGF-β1 concentration. In addition, the overexpression of Nrf2 presented contradictory results. What is more, the PI3K/Akt signaling pathway was discovered to be activated in the proteins extracted from cultured cells, and treated with Nrf2 siRNA and kidney tissues from the Nrf2-/- + UUO group. The results we obtained demonstrate that Nrf2 signaling pathway may perhaps offset the development of EMT, prompted by TGF-β1 and renal interstitial fibrosis. Likewise, the anti-fibrotic effect of Nrf2 was imparted by the inactivation of PI3K/Akt signaling. From our discoveries, we deliver new insight related to the prevention and treatment of kidney fibrosis.

Wang J ，Zhu H ，Huang L ，Zhu X ，Sha J ，Li G ，Ma G ，Zhang W ，Gu M ，Guo Y ... -  《-》