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American Heart Association

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Final ID: 47

Deletion of PRR in AgRP Neurons of the Arcuate Nucleus Contributes to the Development of DOCA-Salt Hypertension

Abstract Body: Agouti-related protein (AgRP) neurons, a key neuronal population within the arcuate nucleus (ARC), are known for their pivotal roles in regulating energy- and glucose homeostasis. However, their involvement in cardiovascular regulation remains poorly understood. Using RNAscope in situ hybridization, we found that 95.4% of the ARCAgRP neurons express the (pro)renin receptor (PRR), a component of the brain renin-angiotensin system that is crucial for blood pressure (BP) regulation. We therefore hypothesized that PRR signaling in the ARCAgRP neurons plays a regulatory role in the development of hypertension. To test this hypothesis, we selectively deleted PRR in ARCAgRP neurons by crossing AgRP-IRES-Cre mice with PRRfl/fl mice. Using RNAscope, as expected, AgRPCre+PRRfl/y mice displayed a significantly lower PRR mRNA in the ARCAgRP neurons than WT mice (76.3 ± 6.1 vs. 127.7 ± 2.9 AFU, p < 0.05), indicating efficient ablation of PRR in ARCAgRP neurons. To examine the impact of PRR deletion in the ARCAgRP neurons on BP, the AgRPCre+PRRfl/y and control mice were implanted with telemetry probes to monitor BP continuously. After baseline recording, mice received DOCA-salt treatment (50 mg DOCA + saline as drinking water) for two weeks. BP variability and standard time domain heart rate variability (HRV) parameters, including overall HRV (SDNN) and short-term HRV (rMSSD), were analyzed from beat-to-beat intervals (n = 2-7 mice/group). At baseline, there was no difference between the two groups in BP, BP variability, and HRV. Two weeks of DOCA-salt induced a significantly higher BP in AgRPCre+PRRfl/y mice than the controls (156.2 ± 6 vs. 119.4 ± 3 mmHg, p < 0.05), while BP variability did not differ between the two groups. Noteworthy, AgRPCre+PRRfl/y mice exhibited lower SDNN than the controls (13.3 ± 4 vs. 19.4 ± 4 ms), indicating increased sympathetic and/or reduced parasympathetic nervous activity. This lower SDNN suggests impaired cardiac autonomic function and adaptability to physiological demands in AgRPCre+PRRfl/y mice. Concurrently, AgRPCre+PRRfl/y mice showed a lower rMSSD (4.7 ± 0.5 vs. 10.8 ± 3.5 ms), implying reduced parasympathetic activity. In conclusion, deletion of PRR in the ARCAgRP neurons results in compromised cardiac autonomic function associated with the development of hypertension. Our findings underscore a novel protective role of PRR signaling in the ARCAgRP neurons in BP regulation.
  • Pan, Shiyue  ( University of Nevada, Reno , Reno , Nevada , United States )
  • Mizuno, Yuma  ( UNIVERSITY OF NEVADA, RENO , Reno , Nevada , United States )
  • Chen, Gang  ( UNIVERSITY OF NEVADA, RENO , Reno , Nevada , United States )
  • Morton, Gregory  ( University of Washington , Seattle , Washington , United States )
  • Schwartz, Michael  ( University of Washington , Seattle , Washington , United States )
  • Feng Earley, Yumei  ( UNIVERSITY OF NEVADA, RENO , Reno , Nevada , United States )
  • Author Disclosures:
    Shiyue Pan: DO NOT have relevant financial relationships | Yuma Mizuno: No Answer | gang chen: No Answer | Gregory Morton: No Answer | Michael Schwartz: DO have relevant financial relationships ; Research Funding (PI or named investigator):Novo Nordisk:Active (exists now) ; Consultant:NodThera Inc:Active (exists now) | Yumei Feng Earley: DO NOT have relevant financial relationships
Meeting Info:
Session Info:

18.A TAC Oral Abstract Award Competition

Saturday, 09/07/2024 , 01:30PM - 03:00PM

Oral Abstract TAC Award

More abstracts on this topic:
More abstracts from these authors:
Prorenin Increases the Firing Activity of Hypothalamic Arcuate Nucleus AgRP Neurons

Zheng Haifeng, Pan Shiyue, Chen Gang, Morton Gregory, Schwartz Michael, Feng Earley Yumei

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