Abstract: TH-PO327
Adrenal-Specific Knockout of the Circadian Clock Protein BMAL1 Alters Kidney Clock Gene Expression
Session Information
- Fluid, Electrolyte, and Acid-Base Disorders: Basic
November 03, 2022 | Location: Exhibit Hall, Orange County Convention Center‚ West Building
Abstract Time: 10:00 AM - 12:00 PM
Category: Fluid‚ Electrolyte‚ and Acid-Base Disorders
- 1001 Fluid‚ Electrolyte‚ and Acid-Base Disorders: Basic
Authors
- Costello, Hannah Mhairi, University of Florida, Gainesville, Florida, United States
- Mckee, Annalisse Ray, University of Florida, Gainesville, Florida, United States
- Crislip, G. Ryan, University of Florida, Gainesville, Florida, United States
- Cheng, Kityan, University of Florida, Gainesville, Florida, United States
- Juffre, Alexandria, University of Florida, Gainesville, Florida, United States
- Douma, Lauren G., University of Florida, Gainesville, Florida, United States
- Gumz, Michelle L., University of Florida, Gainesville, Florida, United States
Background
Circadian rhythms are internal variations in physiological function coordinated by the molecular clock, comprised of 4 core clock proteins – BMAL1, CLOCK, CRY, and PER. Our lab has an interest in how peripheral circadian clocks, including the kidney and adrenal clocks, contribute to renal function. Many renal processes exhibit a circadian rhythm, such as urine flow rate. It is known that kidney clocks contribute to its regulation, but the kidney clocks are disrupted in many animal models of kidney disease. However, little is known about how the kidney clocks tick. Previous data from the lab has shown that kidney-specific knockout (KO) of PER1 altered adrenal clock gene expression. This led to our hypothesis of adrenal-kidney clock cross talk and a role for the adrenal clock in the regulation of kidney clock expression.
Methods
To test this, we utilized the adrenal-specific aldosterone synthase Cre positive (AS)-BMAL1 KO mouse model. Kidneys from AS-BMAL1 KO male mice and littermate Cre negative, floxed control (CNTL) male mice (n=7-8/genotype) were collected at 6AM and 6PM. Kidneys were separated into cortex and medulla before RNA was isolated for clock gene expression analysis using qPCR.
Results
Here, we show significant differences in clock gene expression in the kidney cortex but no changes in the kidney medulla of AS-BMAL1 KO compared with CNTL. There was a significant interaction between time and genotype in Bmal1, Clock and Cry1 (ANOVA interaction p=0.010, p=0.043, and p=0.024, respectively) in the kidney cortex. Sidak multiple comparisons showed increases in Bmal1 (p=0.0070) and Cry1 (p=0.024) at 6AM in KO animals vs. CNTL, whereas Clock was reduced at 6PM (p=0.011). No genotype effects were detected in Cry2 and Per1 expression. There were no significant differences in clock gene expression in the kidney medulla between genotypes. All clock genes in both cortex and medulla demonstrated a significant time of day effect (p<0.01).
Conclusion
BMAL1 KO in the adrenal gland has differential effects on kidney clock gene expression in a region-specific manner, with changes only in the cortex. Future work will utilize tissue-specific clock KO models to focus on whether peripheral clock cross talk contributes to regulation of renal function and how they work together in a cell-specific manner.
Funding
- Private Foundation Support