Hirudin Reduces the Expression of Markers of the Extracellular Matrix in Renal Tubular Epithelial Cells in a Rat Model of Diabetic Kidney Disease Through the Hypoxia-Inducible Factor-1α (HIF-1α)/Vascular Endothelial Growth Factor (VEGF) Signaling Pathway.

BACKGROUND This study aimed to investigate the effects of hirudin on the production of extracellular matrix (ECM) factors by renal tubular epithelial cells in a rat model of diabetic kidney disease (DKD) and HK-2 human renal tubule epithelial cells. MATERIAL AND METHODS Sprague-Dawley rats were divided into the normal control group (n=10), the normal control+hirudin group (n=10), the DKD model group (n=12) and the DKD+hirudin group (n=12). At the end of the study, renal histopathology was undertaken, and the expression of type IV collagen, fibronectin, hypoxia-inducible factor-1alpha (HIF-1alpha), and vascular endothelial growth factor (VEGF) were evaluated using immunohistochemistry, Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). HK-2 cells were cultured in glucose and treated with hirudin. Protein and mRNA expression of fibronectin, type IV collagen, HIF-1alpha, and VEGF were evaluated following knockdown or overexpression of HIF-1alpha. RESULTS Hirudin significantly improved renal function in the rat model of DKD (P<0.01), and significantly down-regulated the expression of fibronectin, type IV collagen, HIF-1alpha, and VEGF proteins (P<0.05). The expression of ECM associated proteins was increased in HK-2 cells treated with high glucose and reduced in the high glucose+shRNA HIF-1alpha group (P<0.05). Compared with the control group, the expression of ECM associated proteins was increased in the HIF-1alpha over-expressed group, and decreased following treatment with hirudin (P<0.05). CONCLUSIONS Hirudin reduced the expression of markers of ECM by inhibiting the HIF-1alpha/VEGF signaling pathway in DKD renal tubular epithelial cells.

Exploring the mechanism of hirudin in the treatment of diabetic kidney disease using network pharmacology combined with molecular docking verification.

OBJECTIVE: To explore the mechanism of hirudin in the treatment of diabetic kidney disease (DKD). METHOD: Cytoscape software was used to analyze the network between hirudin targets and active components in the treatment of DKD. The biological function and mechanism of effective targets of hirudin for DKD treatment were analyzed by the Database for Annotation, Visualization and Integrated Discovery (DAVID) database. Molecular docking technology was used to simulate the docking of key targets, and the DKD rat model was used to verify the first 4 key targets with high "Hydrogen number" among the top 10 targets verified by molecular docking. RESULTS: Total of 12334 DKD targets were screened in GeneCards, OMIM and other databases, Hirudin and DKD had 247 common target genes, and the protein interaction network got 2115 edges. The DAVID database was used for the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, confirming that hirudin in treatment of DKD involves multiple signaling pathways such as the forkhead box O signaling pathway, the phosphatidylinositol 3-kinase-protein kinase B signaling pathway, the vascular endothelial-derived growth factor signaling pathway and other signaling pathways. The top ten key targets of hirudin in treatment of DKD were verified by molecular docking. Animal experiments showed that hirudin could decrease the expression of caspase-3 in renal tissue of DKD rats, and increase the expression of RAC-alpha serine/threonine-protein kinase, Catalase, and Heat shock protein HSP 90-alpha in renal tissue of DKD rats. CONCLUSION: This study preliminarily reveals that hirudin treats DKD through multiple targets and pathways, and molecular docking and animal experiments indicates the feasibility of this study. Hirudin may be directly or indirectly involved in the regulation of cell metabolism, oxidative stress and other mechanisms in the treatment of DKD, which will lay the foundation for future molecular biological experiments of hirudin in the treatment of DKD.