👤 Candida Cristina Quarta

Hypothalamic pro-opiomelanocortin (POMC) neurons are classically viewed as mediators of satiety, acting in response to metabolic and hormonal cues and in opposition to Agouti-related protein (AgRP) neurons to maintain energy balance. This model, centered on the appetite-suppressant effects of the POMC-derived neuropeptide α-melanocyte-stimulating hormone (α-MSH) through its activation of melanocortin-4 receptors (MC4R), has shaped our understanding of feeding and body weight regulation for decades. However, recent discoveries have challenged and expanded this traditional view, revealing that POMC neurons are not a uniform population dedicated solely to satiety control. Single-cell transcriptomic analyses have revealed striking molecular heterogeneity, reflected in distinct anatomical distributions, receptor expression profiles, electrophysiological properties, and projection patterns - all supporting the idea of functional specialization within this neuronal population. In this review, we propose a conceptual framework that integrates POMC neuronal heterogeneity with the regulation of appetite, metabolic physiology, and behavior beyond feeding. We highlight emerging evidence showing that discrete POMC neuronal subpopulations respond to specific combinations of interoceptive and environmental cues to orchestrate diverse adaptive responses. This perspective underscores the developmental plasticity and functional versatility of POMC neurons, offering new insights into the mechanisms of obesity and potentially paving the way for novel targeted therapeutic strategies. Show less

Amyloid transthyretin (ATTR) amyloidosis is a rare, life-threatening disease frequently manifesting with cardiomyopathy (ATTR-CM), polyneuropathy (ATTR-PN) or both (ATTR-mixed). We retrospectively analysed US electronic health records and claims data to provide up-to-date estimates of ATTR amyloidosis epidemiology (overall and by phenotype). Data were extracted from the Clarivate Real-World Data repository (2016-2023). Given the lack of established coding for ATTR amyloidosis, we used different combinations of diagnostic codes to obtain narrow and broad estimates of incident and prevalent cases in the USA in 2022. Temporal trends (2019-2022) were also assessed. Using narrow definitions, the 2022 estimated incidence of ATTR amyloidosis overall, ATTR-CM, ATTR-PN and ATTR-mixed was 16.6, 12.7, 3.5 and 1.9 cases per million people, respectively; the corresponding prevalence estimates were 59.8, 41.1, 15.1 and 9.8 cases per million people. Estimates were consistently lower with the narrow (vs broad) definitions. Over time, the incidence and prevalence of ATTR amyloidosis overall increased, driven by ATTR-CM cases. No major changes were reported for the other phenotypes. This study provides comprehensive and up-to-date epidemiological data for ATTR amyloidosis in the USA. Our findings corroborate the need for appropriate differential diagnostic coding and standardised criteria. Show less

Hypothalamic AgRP and POMC neurons are conventionally viewed as the yin and yang of the body's energy status, since they act in an opposite manner to modulate appetite and systemic energy metabolism. However, although AgRP neurons' functions are comparatively well understood, a unifying theory of how POMC neuronal cells operate has remained elusive, probably due to their high level of heterogeneity, which suggests that their physiological roles might be more complex than initially thought. In this Perspective, we propose a conceptual framework that integrates POMC neuronal heterogeneity with appetite regulation, whole-body metabolic physiology and the development of obesity. We highlight emerging evidence indicating that POMC neurons respond to distinct combinations of interoceptive signals and food-related cues to fine-tune divergent metabolic pathways and behaviours necessary for survival. The new framework we propose reflects the high degree of developmental plasticity of this neuronal population and may enable progress towards understanding of both the aetiology and treatment of metabolic disorders. Show less

Pharmacological stimulation of brown adipose tissue (BAT) thermogenesis to increase energy expenditure is progressively being pursued as a viable anti-obesity strategy. Here, we report that pharmacological activation of the cold receptor transient receptor potential cation channel subfamily M member 8 (TRPM8) with agonist icilin mimics the metabolic benefits of cold exposure. In diet-induced obese (DIO) mice, treatment with icilin enhances energy expenditure, and decreases body weight, without affecting food intake. To further potentiate the thermogenic action profile of icilin and add complementary anorexigenic mechanisms, we set out to identify pharmacological partners next to icilin. To that end, we specifically targeted nicotinic acetylcholine receptor (nAChR) subtype alpha3beta4 (α3β4), which we had recognized as a potential regulator of energy homeostasis and glucose metabolism. Combinatorial targeting of TRPM8 and nAChR α3β4 by icilin and dimethylphenylpiperazinium (DMPP) orchestrates synergistic anorexic and thermogenic pathways to reverse diet-induced obesity, dyslipidemia, and glucose intolerance in DIO mice. Show less