Human iPSC-Derived Hypothalamic Neurons from Super Obese Patients Exhibit Obesogenic Transcriptional Profiles and Dysregulated Hormone Responses

The arcuate nucleus of the hypothalamus contains neurons responsible for feeding. They control metabolic processes by secretion of neuropeptides in response to hunger and satiety signals from the gastrointestinal tract, pancreas and adipose tissue. Here we aim at addressing the challenge of non-availability of developing human brain/hypothalamic tissues for study. To bridge this gap, we generated human induced pluripotent stem cells (hiPSCs) from lymphoblasts of super obese (body mass index (BMI) ≥ 50) and normal (BMI ≤ 25) subjects and differentiated them into hypothalamic-like neuronal cultures (iHTNs), specifically those expressing pro-opiomelanocortin (POMC), agouti-related peptide (AgRP), cocaine and amphetamine regulating transcript (CART) and neurons capable of secreting neuropeptides such as neuropeptide Y (NPY) and alpha-melanocyte stimulating hormone (MSH). Of the total number of neurons (approx.75% of cells in culture), we saw 42% MSH , 44% NPY , 28% AgRP and 20% POMC/CART neurons. Bioinformatics analyses of transcriptomics from day 40 differentiated iHTNs reveal that these neuronal cultures maintain predominantly a fetal hypothalamic identity. We further show that these neurons are capable of relevantly responding to physiological (exogenous) metabolic stimuli e.g. ghrelin and leptin. Notably, transcriptomics of iHTNs obtained from super obese individuals retained signatures of obesity showing specific dysregulation of obesity-related genes such as neuronal growth regulator 1 (NEGR1) and secretogranin 3 (SCG3). Ingenuity Pathway Analysis also highlighted dysregulation of several obesity-related metabolic pathways like leptin signaling, GPCR-mediated enteroendocrine signaling, as well as the ER stress and inflammasome pathways in super obese iHTNs when compared to controls. The methods and characterization of iHTNs described here could serve as a cellular platform for modeling and testing gene-environment interactions involved in metabolic diseases and obesity.