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Sex Modulates Response to Renal-Tubule-Targeted Insulin Receptor Deletion in Mice
Insulin facilitates renal sodium reabsorption and attenuates gluconeogenesis. Sex differences in this regulation have not been well characterized. Using tetracycline-inducible Cre-lox recombination, we knocked out (KO) the insulin receptor (InsR) from the renal tubule in adult male (M) and female (F...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10178497/ https://www.ncbi.nlm.nih.gov/pubmed/37175762 http://dx.doi.org/10.3390/ijms24098056 |
Sumario: | Insulin facilitates renal sodium reabsorption and attenuates gluconeogenesis. Sex differences in this regulation have not been well characterized. Using tetracycline-inducible Cre-lox recombination, we knocked out (KO) the insulin receptor (InsR) from the renal tubule in adult male (M) and female (F) mice (C57Bl6 background) with a paired box 8 (PAX8) promoter. Body weights were not affected by the KO, but mean kidney weights were reduced in the KO mice (13 and 3%, in M and F, respectively, relative to wild-type (WT) mice). A microscopic analysis revealed 25 and 19% reductions in the proximal tubule (PT) and cortical collecting duct cell heights, respectively, in KOMs relative to WTMs. The reductions were 5 and 11% for KOFs. Western blotting of renal cortex homogenates showed decreased protein levels for the β and γ subunits of the epithelial sodium channel (ENaC) and the sodium-potassium-2-chloride cotransporter type 2 (NKCC2) in both sexes of KO mice; however, α-ENaC was upregulated in KOMs and downregulated in KOFs. Both sexes of KO mice cleared exogenously administered glucose faster than the WT mice and had lower semi-fasted, anesthetized blood glucose levels. However, KOMs (but not KOFs) demonstrated evidence of enhanced renal gluconeogenesis, including higher levels of renal glucose-6-phosphatase, the PT’s production of glucose, post-prandial blood glucose, and plasma insulin, whereas KOFs exhibited downregulation of renal high-capacity sodium glucose cotransporter (SGLT2) and upregulation of SGLT1; these changes appeared to be absent in the KOM. Overall, these findings suggest a sex-differential reliance on intact renal tubular InsR signaling which may be translationally important in type 2 diabetes, obesity, or insulin resistance when renal insulin signaling is reduced. |
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