Balyssa Bell

Mentor: Kamal Rahmouni, PhD

Year Entered Into Program: 2012

PhD Institution: University of Iowa, 2018

Affiliations

  • Pharmacology

Research Description

Regulation of blood pressure and metabolism by hypothalamic mTOR signaling

My research is focused on the neurological regulation of obesity and hypertension by the PI3K-mTORC1 signaling pathway in the hypothalamus. The cardiovascular sympathetic effect of leptin appears to be mediated by neurons located in the arcuate nucleus of the hypothalamus. The first part of my work is focused on elucidating which neuronal populations in the arcuate control the metabolic and regional sympathetic effects of leptin. Using mouse models with conditional deletion of leptin receptors from proopiomelanocortin (POMC) or agouti-related protein (AgRP) neurons, I have been working to determine the relative contributions of these two cell types to the various downstream effects of leptin, demonstrating that while both contribute to leptin’s metabolic effects, the regional sympathetic effects of leptin are controlled by different neurons. Additionally, our lab has previously shown that hypothalamic mammalian target of rapamycin complex 1 (mTORC1) signaling is involved in the regulation of blood pressure and sympathetic nerve activity and mediates leptin responses. The goal of my work is to elucidate how the PI3K-mTORC1 axis contributes to leptin regulation of physiological processes using genetically modified mouse models with conditional deletion of components of this axis in leptin receptor expressing cells and specifically in POMC neurons, which are thought to mediate the sympathetic and arterial pressure responses induced by leptin. This will be determined by analyzing several physiological parameters including blood pressure, sympathetic nerve activity, food intake and body weight in mice fed normal chow or a high fat diet (45% kcal), as well as in response to leptin challenge.

Award(s)

  • University of Iowa Graduate Student Senate Travel Award, 2017
  • 4th Annual Abboud Cardiovascular Research Center Symposium Poster Session Travel Award, 2017
  • American Physiological Society Endocrinology and Metabolism Section Campbell Award Winner, 2017
  • Experimental Biology Featured Abstract Travel Award, 2017
  • Abboud Cardiovascular Research Center Symposium Poster Competition Winner, 2017
  • NIH / NRSA Predoctoral Fellowship (F31 HL134224), 2016-2018
  • American Heart Association Council on Hypertension Top Trainee Oral Abstract Award; Early Career Award Finalist, 2016
  • University of Iowa Graduate Student Senate Travel Award, 2016
  • American Heart Association Council on Hypertension Top Trainee Oral Abstract Award; Early Career Award Finalist, 2015
  • Iowa Physiological Society Outstanding Graduate Poster Presentation Award, 2015
  • Experimental Biology Feature Abstract Travel Award, March 2015
  • University of Iowa Graduate and Professional Student Government Travel Award, 2015
  • University of Iowa Graduate Student Senate Travel Awards, 2014, 2015
  • Fellowship appointment on the Pharmacological Sciences Training Program (NIH T32 GM067795), University of Iowa, 2013-2015

Publications

  1. Bell BB, Rahmouni K.:  Leptin as a Mediator of Obesity-induced Hypertension. Curr Obes Rep 5(4):397-404, 2016.  PMCID: PMC5119542

Awards since graduating the U of IA

  • Postdoctoral Fellowship on the Cardiovascular Institutional Research Fellowship, (T32 HL007121) NIH/NHLBI, University of Iowa, 2018-present