RNA-seq reveals altered gene expression levels in proximal tubular cell cultures compared to renal cortex but not during early glucotoxicity

AbstractCell cultures are often used to study physiological processes in
health and disease. It is well-known that cells change their gene
expression in vitro compared to in vivo, but it is rarely experimentally
addressed. High glucose is a known trigger of apoptosis in proximal
tubular cells (PTC). Here we used RNA-seq to detect differentially
expressed genes in cultures of primary rat PTC, 3 days old,
compared to cells retrieved directly from rat outer renal cortex and
between PTC exposed to 15 mM glucose and control for
8 h. The expression of 6,174 genes was significantly up- or
downregulated in the cultures of PTC compared to the cells in the outer
renal cortex. Most altered were mitochondrial and metabolism related
genes. Gene expression of proapoptotic proteins were upregulated and gene
expression of antiapoptotic proteins were downregulated in PTC. Expression
of transporter related genes were generally downregulated. After
8 h, high glucose had not altered the gene expression in PTC. The
current study provides evidence that cells alter their gene expression in
vitro compared to in vivo and suggests that short-term high glucose
exposure can trigger apoptosis in PTC without changing the gene expression
levels of apoptotic proteins.