[HTML][HTML] Insulin receptor signaling regulates renal collecting duct and intercalated cell antibacterial defenses

MJ Murtha, T Eichler, K Bender… - The Journal of …, 2018 - Am Soc Clin Investig
MJ Murtha, T Eichler, K Bender, J Metheny, B Li, AL Schwaderer, C Mosquera, C James…
The Journal of Clinical Investigation, 2018Am Soc Clin Investig
People with diabetes mellitus have increased infection risk. With diabetes, urinary tract
infection (UTI) is more common and has worse outcomes. Here, we investigate how
diabetes and insulin resistance impact the kidney's innate defenses and urine sterility. We
report that type 2 diabetic mice have increased UTI risk. Moreover, insulin-resistant
prediabetic mice have increased UTI susceptibility, independent of hyperglycemia or
glucosuria. To identify how insulin resistance affects renal antimicrobial defenses, we …
People with diabetes mellitus have increased infection risk. With diabetes, urinary tract infection (UTI) is more common and has worse outcomes. Here, we investigate how diabetes and insulin resistance impact the kidney’s innate defenses and urine sterility. We report that type 2 diabetic mice have increased UTI risk. Moreover, insulin-resistant prediabetic mice have increased UTI susceptibility, independent of hyperglycemia or glucosuria. To identify how insulin resistance affects renal antimicrobial defenses, we genetically deleted the insulin receptor in the kidney’s collecting tubules and intercalated cells. Intercalated cells, located within collecting tubules, contribute to epithelial defenses by acidifying the urine and secreting antimicrobial peptides (AMPs) into the urinary stream. Collecting duct and intercalated cell–specific insulin receptor deletion did not impact urine acidification, suppressed downstream insulin-mediated targets and AMP expression, and increased UTI susceptibility. Specifically, insulin receptor–mediated signaling regulates AMPs, including lipocalin 2 and ribonuclease 4, via phosphatidylinositol-3-kinase signaling. These data suggest that insulin signaling plays a critical role in renal antibacterial defenses.
The Journal of Clinical Investigation