Canagliflozin alleviates pulmonary hypertension by activating PPARγ and inhibiting its S225 phosphorylation.

Pulmonary hypertension (PH) is a progressive fatal disease with no cure. Canagliflozin (CANA), a novel medication for diabetes, has been found to have remarkable cardiovascular benefits. However, few studies have addressed the effect and pharmacological mechanism of CANA in the treatment of PH. Therefore, our study aimed to investigate the effect and pharmacological mechanism of CANA in treating PH. First, CANA suppressed increased pulmonary artery pressure, right ventricular hypertrophy, and vascular remodeling in both mouse and rat PH models. Network pharmacology, transcriptomics, and biological results suggested that CANA could ameliorate PH by suppressing excessive oxidative stress and pulmonary artery smooth muscle cell proliferation partially through the activation of PPARγ. Further studies demonstrated that CANA inhibited phosphorylation of PPARγ at Ser225 (a novel serine phosphorylation site in PPARγ), thereby promoting the nuclear translocation of PPARγ and increasing its ability to resist oxidative stress and proliferation. Taken together, our study not only highlighted the potential pharmacological effect of CANA on PH but also revealed that CANA-induced inhibition of PPARγ Ser225 phosphorylation increases its capacity to counteract oxidative stress and inhibits proliferation. These findings may stimulate further research and encourage future clinical trials exploring the therapeutic potential of CANA in PH treatment.

Microarray Expression Profile of Exosomal circRNAs from High Glucose Stimulated Human Renal Tubular Epithelial Cells.

Introduction: Circular RNA (circRNAs) are a type of non-coding RNA (ncRNAs) with a wealth of functions. Recently, circRNAs have been identified as important regulators of diabetic kidney disease (DKD), owing to their stability and enrichment in exosomes. However, the role of circRNAs in exosomes of tubular epithelial cells in DKD development has not been fully elucidated. Methods: In our study, microarray technology was used to analyze circRNA expression in cell supernatant exosomes isolated from HK-2 cells with or without high glucose (HG) treatment. The small interfering RNAs (siRNA) and plasmid overexpression were used to validate functions of differentially expressed circRNAs. Results: We found that exosome concentration was higher in HG-stimulated HK-2 cells than in controls. A total of 235 circRNAs were significantly increased and 458 circRNAs were significantly decreased in the exosomes of the HG group. In parallel with the microarray data, the qPCR results showed that the expression of circ_0009885, circ_0043753, and circ_0011760 increased, and the expression of circ_0032872, circ_0004716, and circ_0009445 decreased in the HG group. Rescue experiments showed that the effects of high glucose on regulation of CCL2, IL6, fibronetin, n cadherin, e cadherin and epcam expression can be reversed by inhibiting or overexpressing these circRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analyses indicated that circRNA parental genes are associated with glucose metabolism, lipid metabolism, and inflammatory processes, which are important in DKD development. Further analysis of circRNA/miRNA interactions indicated that 152 differentially expressed circRNAs with fold change (FC) ≥1.5 could be paired with 43 differentially expressed miRNAs, which are associated with diabetes or DKD. Discussion: Our results indicate that exosomal circRNAs may be promising diagnostic and therapeutic biomarkers, and may play a critical role in the progression of DKD.