Comprehensive study of altered proteomic landscape in proximal renal tubular epithelial cells in response to calcium oxalate monohydrate crystals.

BACKGROUND: Calcium oxalate monohydrate (COM), the major crystalline composition of most kidney stones, induces inflammatory infiltration and injures in renal tubular cells. However, the mechanism of COM-induced toxic effects in renal tubular cells remain ambiguous. The present study aimed to investigate the potential changes in proteomic landscape of proximal renal tubular cells in response to the stimulation of COM crystals. METHODS: Clinical kidney stone samples were collected and characterized by a stone component analyzer. Three COM-enriched samples were applied to treat human proximal tubular epithelial cells HK-2. The proteomic landscape of COM-crystal treated HK-2 cells was screened by TMT-labeled quantitative proteomics analysis. The differentially expressed proteins (DEPs) were identified by pair-wise analysis. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of DEPs were performed. Protein interaction networks were identified by STRING database. RESULTS: The data of TMT-labeled quantitative proteomic analysis showed that a total of 1141 proteins were differentially expressed in HK-2 cells, of which 699 were up-regulated and 442 were down-regulated. Functional characterization by KEGG, along with GO enrichments, suggests that the DEPs are mainly involved in cellular components and cellular processes, including regulation of actin cytoskeleton, tight junction and focal adhesion. 3 high-degree hub nodes, CFL1, ACTN and MYH9 were identified by STRING analysis. CONCLUSION: These results suggested that calcium oxalate crystal has a significant effect on protein expression profile in human proximal renal tubular epithelial cells.

Analyses of long non-coding RNA and mRNA profiling using RNA sequencing in calcium oxalate monohydrate-stimulated renal tubular epithelial cells.

To study the expression profiles of lncRNA and mRNA in the calcium oxalate monohydrate-attached HK-2 cells, and investigate the association between critical lncRNA expression level and renal injury. The HK-2 cells were treated with crystal suspension of calcium oxalate. The effects of calcium oxalate crystals on the growth of HK-2 cells were determined by MTT assay. Total RNA was extracted and the lncRNA and mRNA expression profiles were analyzed by high-throughput transcriptase sequencing platform HiSeq 2500. The profile of identified lncRNAs and mRNAs were verified by real-time PCR and their potential function was analyzed by Gene Ontology database and KEGG signal pathway analysis. Calcium oxalate crystals adhered to the surface of HK-2 cells in few minutes and showed obvious cytotoxicity. RNA seq results showed that there were 25 differentially expressed lncRNAs in HK-2 cells treated with calcium oxalate crystals, of which 9 were up-regulated and 16 were down-regulated. The difference was verified by real-time PCR which showed statistically significant (P < 0.05). Calcium oxalate crystals have a significant effect on lncRNA and mRNA expression in human renal epithelial cells, which may play critical roles in kidney stone-mediated renal injury.

[Expression characteristics of the USP24 gene in the mouse testis during spermatogenesis].

OBJECTIVE: To investigate the expression characteristics of the USP24 gene in the mouse testis and its role in spermatogenesis. METHODS: We examined the expression characteristics of USP24 in the testis tissues of wild-type mice at different postnatal weeks (PNW) and androgen receptor (AR)-knockout (ARKO) adult mice using real-time quantitative PCR and immunofluorescence, and detected the transcriptional activity of the USP24 promoter by dual-luciferase reporter gene assay. RESULTS: The expression of the USP24 gene was low in the testis tissue of the wild-type mice at PNW 1, increased dramatically at PNW 3 and stayed at a similar level till PNW 8. The USP24 protein was located mainly in the cytoplasm of Sertoli and spermatogenic cells. Compared with the wild-type, the adult ARKO mice showed a decreased expression of USP24 localized in the posterior head and mid-piece of the mature sperm in the testis. Dual-luciferase reporter gene assay showed that the transcriptional activity of the USP24 promoter was increased after testosterone stimulation. CONCLUSIONS: The increased expression of the USP24 gene was associated with the initiation of sexual development, and the USP24 protein was expressed in the mature sperm of the mice. USP24 is an AR-target gene, which may be involved in the regulation of spermatogenesis in mice.