Identification and analysis of differently expressed transcription factors in aristolochic acid nephropathy.

BACKGROUND: Aristolochic acid nephropathy (AAN) is a rapidly progressive interstitial nephropathy caused by Aristolochic acid (AA). AAN is associated with the development of nephropathy and urothelial carcinoma. It is estimated that more than 100 million people worldwide are at risk of developing AAN. However, the underlying mechanisms driving renal deterioration in AAN remain poorly understood, and the treatment options are limited. METHODS: We obtained GSE27168 and GSE136276 series matrix data from the Gene Expression Omnibus (GEO) related to AAN. Using the R Studio environment, we applied the limma package and WGCNA package to identify co-differently expressed genes (co-DEGs). By GO/KEGG/GSVA analysis, we revealed common biological pathways. Subsequently, co-DEGs were subjected to the String database to construct a protein-protein interaction (PPI) network. The MCC algorithms implemented in the Cytohubba plugin were employed to identify hub genes. The hub genes were cross-referenced with the transcription factor (TF) database to identify hub TFs. Immune infiltration analysis was performed to identify key immune cell groups by utilizing CIBERSORT. The expressions of AAN-associated hub TFs were verified in vivo and in vitro. Finally, siRNA intervention was performed on the two TFs to verify their regulatory effect in AAN. RESULTS: Our analysis identified 88 co-DEGs through the "limma" and "WGCNA" R packages. A PPI network comprising 53 nodes and 34 edges was constructed with a confidence level >0.4. ATF3 and c-JUN were identified as hub TFs potentially linked to AAN. Additionally, expressions of ATF3 and c-JUN positively correlated with monocytes, basophils, and vessels, and negatively correlated with eosinophils and endothelial cells. We observed a significant increase in protein and mRNA levels of these two hub TFs. Furthermore, it was found that siRNA intervention targeting ATF3, but not c-JUN, alleviated cell damage induced by AA. The knockdown of ATF3 protects against oxidative stress and inflammation in the AAN cell model. CONCLUSION: This study provides novel insights into the role of ATF3 in AAN. The comprehensive analysis sheds light on the molecular mechanisms and identifies potential biomarkers and drug targets for AAN treatment.

TGF-ß1/PTEN/PI3K signaling plays a critical role in the anti-proliferation effect of tetrandrine in human colon cancer cells.

The diagnosis and treatment for colon cancer have been greatly developed, but the prognosis remains unsatisfactory. There is still a great clinical need to explore new efficacious drugs for colon cancer treatment. Tetrandrine (Tet) is a bis-benzylisoquinoline alkaloid. It has been shown that Tet may be a potential candidate for cancer treatment, but the explicit mechanism underlying this activity remains unclear. In this study, we investigated the anticancer activity of Tet in human colon cancer cells and dissected the possible mechanism. With cell viability assay and flow cytometry analysis, we confirmed that Tet can effectively inhibit the proliferation and induce apoptosis in HCT116 cells. Mechanically, we found that Tet greatly increases the mRNA and protein level of TGF-ß1 in HCT116 cells. Exogenous TGF-ß1 enhances the anti-proliferation and apoptosis inducing effect of Tet in HCT116 cells, which has been partly reversed by TGF-ß1 inhibitor. Tet decreases the phosphorylation of Akt1/2/3 in HCT116 cells. This effect can be enhanced by exogenous TGF-ß1, but partly reversed by TGF-ß1 inhibitor. Tet exhibits no effect on total level of PTEN, but decreases the phosphorylation of PTEN; exogenous TGF-ß1 enhances the effect of Tet on decreasing the phosphorylation of PTEN, which was partly reversed by TGF-ß1 inhibitor. Our findings suggested that Tet may be a promising candidate for colon cancer treatment, and the anticancer activity may be mediated by inactivating PI3K/Akt signaling through upregulating TGF-ß1 to decrease the phosphorylation of PTEN.

Resveratrol inactivates PI3K/Akt signaling through upregulating BMP7 in human colon cancer cells.

Colon cancer is common worldwide and accounts for the significant cancer related morbidity and mortality in patients. Although extensive advancement has been made in colon cancer treatment and diagnosis in the last decades, there is still a giant gap between the clinical expectation. It has been reported that resveratrol (Res) may be a potential candidate for cancer treatment. However, the specific mechanism underlying this activity remains unclear. In this study, we investigated the anticancer activity of Res in human colon cancer cells, and unveiled the possible mechanism for this effect. With cell viability, flow cytometry, PCR and western blot analysis, we demonstrated the efficacious anticancer activity of Res in HCT116 cells. Mechanically, we found that Res greatly upregulates BMP7 in HCT116 cells. Exogenous BMP7 enhances the anticancer effect of Res in HCT116 cells, which was almost reversed by the BMP7 specific antibody. Res does not activate the BMPs/Smads signaling, but decreases the phosphorylation of Akt1/2/3 substantially in HCT116 cells. Exogenous BMP7 enhances the inhibitory effect of Res on the phosphorylation of Akt1/2/3, while BMP7 immunodepletion reverses this effect notably. Res markedly decreases the phosphorylation of PTEN, which can be enhanced by exogenous BMP7 but partly reversed by the BMP7 antibody. Our findings suggested that Res may be a promising candidate for colon cancer treatment, and the anticancer activity may be mediated by inactivating PI3K/Akt signaling through upregulating BMP7 to decrease, at least, the phosphorylation of PTEN.

Ursolic acid inhibits proliferation and induces apoptosis by inactivating Wnt/ß-catenin signaling in human osteosarcoma cells.

Although multiple chemotherapeutic agents have been used for osteosarcoma (OS) treatment, their mechanisms need further study. Ursolic acid (UA), a pentacyclic triterpenoid, can reduce cell proliferation and induce apoptosis in various cancer cells, such as OS. However, the exact mechanism underlying this function remains unclear. In this study, we investigated the anti­proliferative effect of UA in human OS 143B cells and dissected the possible molecular mechanism underlying this effect. We demonstrated that UA can reduce cell proliferation, induce apoptosis and arrest cell cycle in 143B cells, as well as inhibit OS tumor growth in a mouse xenograft model. Using a luciferase reporter assay, we found that the Wnt/ß­catenin signaling is inhibited by UA in 143B cells. Correspondingly, the expression level and nuclear translocation of ß­catenin are both decreased by UA. Exogenous expression of ß­catenin attenuates the anticancer effect of UA in 143B cells, while knockdown of ß­catenin enhances this effect. UA increases the expression level of p53 in a concentration­dependent manner, and inhibition of p53 reduces the anticancer effect of UA in 143B cells. Moreover, inhibition of p53 partly reverses the UA­induced downregulation of ß­catenin, as do the targets of Wnt/ß­catenin signaling, such as c­Myc and cyclin D1. Our findings indicated that UA can inhibit the proliferation of 143B OS cells through inactivation of Wnt/ß-catenin signaling, which may be mediated partly by upregulating the expression of p53.

All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts.

Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis.