Acute and chronic exposure to high levels of glucose modulates tight junction-associated epithelial barrier function in a renal tubular cell line

• Published in: Life sciences (1973) Vol. 188; pp. 149 - 157
• Main Authors: Mongelli-Sabino, B.M., Canuto, L.P., Collares-Buzato, C.B.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.11.2017; Elsevier BV
• Subjects: Animals; Barriers; Cells, Cultured; Chronic exposure; Claudin-1 - metabolism; Claudin-2 - metabolism; Claudin-3 - metabolism; Claudins; Diabetes; Diabetes mellitus; Diabetic neuropathy; Dogs; Epithelial barrier; Epithelial Cells - drug effects; Epithelial Cells - physiology; Exposure; Glucose; Glucose - adverse effects; Hyperglycemia; Immunofluorescence; Kidney Tubules - cytology; Madin Darby Canine Kidney Cells; MDCK cells; Membrane Potentials - drug effects; Membrane Potentials - physiology; Nephropathy; Occludin; Occludin - metabolism; Paracellular transport; Permeability; Proteins; Renal function; Renal tubular epithelium; Selectivity; Tight junction; Tight Junctions - drug effects; Tight Junctions - metabolism; Tight Junctions - physiology; Type 2 diabetes mellitus; Zonula occludens-1 protein; Hyperglycemia; Claudins; MDCK cells; Paracellular transport; Epithelial barrier; Tight junction; Type 2 diabetes mellitus; Renal tubular epithelium; Occludin
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/j.lfs.2017.09.004

Type 2 diabetes mellitus (T2DM) is one of the most prevalent diseases worldwide. Diabetic nephropathy (DN) is a complication of diabetes and the mechanisms underlying onset and progression of this disease are not fully understood. It has been shown that hyperglycemia is an independent factor to predict the development of DN in individuals with T2DM, however, a link between high plasma glucose levels and renal tubular injuries in DN remains unknown. In this study, we investigated the effect of high levels of glucose (i.e. 180 or 360mg/dL) for up to 24h (acute) or over 72h (chronic) upon tight junction (TJ)-mediated epithelial barrier integrity of the kidney tubular cell line, MDCK. High levels of glucose (180 and 360mg/dL) induced a decrease in transepithelial electrical resistance associated with an increase in TJ cation selectivity at 24h or in TJ permeability to a paracellular marker, Lucifer Yellow, at 72h-exposure when compared to control group (exposed to 100mg/dL glucose). Immunofluorescence analyses showed that glucose treatment induced a significant decrease in the tight junctional content of claudins-1 and -3 as well as a significant increase in claudin-2 (particularly at 24h-exposure) and a time-dependent change in occludin/ZO-1 junctional content. The analyses of total cell content of these junctional proteins by Western blot did not reveal significant changes, except in claudin-2 expression. Our data suggest that high levels of glucose induce time-dependence changes in TJ structure in MDCK monolayers, suggesting a possible link between hyperglycemia-induced tubular epithelial barrier disruption and diabetic nephropathy.