Indoxyl sulfate (IS) is a recognized protein-binding enterogenous uremic toxin that accumulates in patients with chronic kidney disease (CKD) and can cause and promote the occurrence and development of CKD. This experiment explored whether IS could cause damage to human glomerular podocyte cytoskeleton and its possible mechanisms in vitro.

The human glomerular podocyte cell line cultured in vitro was taken as the research object. The cell viability was examined by trypan blue exclusion and MTT assay. Immunofluorescence was used to detect changes in podocyte cytoskeletal fibrous-actin (F-actin) and synaptopodin; Western blot was used to analyze the protein level of synaptopodin; RT-qPCR was used to detect the mRNA expression of synaptopodin; Agarose gel electrophoresis was used to analyze the protein kinase A (PKA) activity.

Fluorescence experiments showed that IS reduced the F-actin and synaptopodin protein expression of podocytes. IS also down-regulated the expression of synaptopodin mRNA (P<0.01). IS treatment increased PKA phosphorylation. PKA pathway blocker H89 upregulated the synaptopodin expression of both protein and mRNA (P<0.01).

IS could down-regulate the podocyte cytoskeleton expression of F-actin and synaptopodin; The PKA signaling pathway may partly participate in the regulatory mechanism of synaptopodin expression; The results of this study might provide new ideas and potential therapeutic targets for the prevention and intervention of CKD.