The hypothalamus contains neurons that integrate hunger and satiety endocrine signals from the periphery and are implicated in the pathophysiology of obesity. The limited availability of human hypothalamic neurons hampers our understanding of obesity disease mechanisms. To address this, we generated human induced pluripotent stem cells (hiPSCs) from multiple normal body mass index (BMI; BMI ≤ 25) subjects and super-obese (OBS) donors (BMI ≥ 50) with polygenic coding variants in obesity-associated genes. We developed a method to reliably differentiate hiPSCs into hypothalamic-like neurons (iHTNs) capable of secreting orexigenic and anorexigenic neuropeptides. Transcriptomic profiling revealed that, although iHTNs maintain a fetal identity, they respond appropriately to metabolic hormones ghrelin and leptin. Notably, OBS iHTNs retained disease signatures and phenotypes of high BMI, exhibiting dysregulated respiratory function, ghrelin-leptin signaling, axonal guidance, glutamate receptors, and endoplasmic reticulum (ER) stress pathways. Thus, human iHTNs provide a powerful platform to study obesity and gene-environment interactions. Human hypothalamic neurons (HTNs) implicated in obesity have a limited availability. This study describes a reliable method for generating functional hormone-responsive HTNs from multiple normal and obese patient reprogrammed hiPSCs. Obese-patient-induced HTNs retained transcriptome profiles and functional phenotypes of high BMI, exhibiting aberrant obesity-related metabolic and respiratory pathways.
Rajamani, U., Gross, A. R., Hjelm, B. E., Sequeira, A., Vawter, M. P., Tang, J., … Sareen, D. (2018). Super-Obese Patient-Derived iPSC Hypothalamic Neurons Exhibit Obesogenic Signatures and Hormone Responses. Cell Stem Cell, 22(5), 698-712.e9. https://doi.org/10.1016/j.stem.2018.03.009