Evaluation of Hypothalamic Neural Stem Cell Niche – Implications on Obesity‐Induced Sympathoexcitation

Abstract

The newly discovered hypothalamic neural stem cell niche is emerging as a key player in the regulation of systemic homeostasis. Previous studies have shown that inflammation‐associated degenerative processes in the hypothalamic neural stem cell niche impairs central regulation of metabolism and contributes to the development of metabolic syndrome in obesity. In addition to energy homeostasis, hypothalamic nuclei specifically paraventricular nucleus, is a well‐known player in the regulation of sympathetic nerve activity and in turn cardiovascular function. How obesity‐induced degeneration of neural stem cell niche affects sympathetic regulation of blood pressure is still not understood. In the present study, we aim to characterize the neural stem cell population from the hypothalamic niche. In this pilot study, 3‐month‐old C57BL/6J mice fed with standard diet were sacrificed and brains were collected for further processing. Hypothalami were freshly isolated and minced. After series of enzymatic dissociation, washing and filtration, NSCs were cultured. On 14th day of culturing, neurospheres were observed without any changes in their structural integrity. Neurosphere counts were recorded, and cells were collected for RNA extraction to perform RT‐PCR analysis for characterization. Our PCR analysis confirmed the expression of NSC markers like nestin, SOX1 and SOX2 suggesting successful isolation and culturing of NSCs in our lab. Earlier studies in our lab, suggest that HFD‐induced obesity causes cellular senescence in the PVN, a region adjacent to the neurogenic niche of hypothalamus. Senescent cells are known to impair the regenerative potential of stem cells by impairment of tissue microenvironment through their secretome. Having established these techniques, future studies will investigate the link between hypothalamic neurogenesis, senescence (in the PVN) and sympathoexcitation in obesity.