New PNOC/NPY neuron population identified as a critical mediator of leptin's appetite-suppressing effects | Research

The takeaway

Hypothalamic PNOC/NPY neurons are a novel mediator of leptin action: leptin receptor loss in PNOC neurons causes obesity via NPY upregulation, and restoring leptin receptor expression substantially reduces body weight.

New appetite neuron discovered
PNOC/NPY neurons in the arcuate nucleus—distinct from classical AgRP/NPY neurons—are a critical new mediator of leptin's appetite-suppressing effect

What the researchers found

PNOC/NPY neurons (non-AgRP) identified in ARC. Lepr deletion in PNOC neurons → hyperphagia + obesity via NPY upregulation. Lepr restoration in PNOC neurons → substantial weight reduction. PNOC/NPY activation promotes feeding = all PNOCARC activation. NPY overexpression in PNOC → hyperphagia + obesity.

Why it matters

This discovers a fundamentally new brain circuit for appetite control, distinct from the well-known AgRP/NPY pathway. It reveals a new target for obesity therapeutics and deepens our understanding of how leptin controls body weight.

How the study worked

Genetic mouse models: Lepr deletion and restoration in PNOC neurons, chemogenetic (DREADD) activation, NPY overexpression in PNOCARC neurons. Body weight, food intake, gene expression analysis.

What this study cannot tell us

Mouse study—human PNOC/NPY neurons may differ. Genetic manipulations are artificial. No pharmacological intervention tested. Translation to human obesity uncertain.

How to read the evidence

Rigorous genetic mouse study with multiple complementary approaches (deletion, restoration, chemogenetics, overexpression). Strong mechanistic evidence.

When this study was published

Published in 2025.

The bigger picture

The leptin-NPY-appetite axis is more complex than previously understood. This PNOC/NPY population adds a new node to the appetite control circuit and a new target for anti-obesity drug development.

Questions still open

Could targeting PNOC/NPY neurons pharmacologically produce weight loss?
Do human hypothalami have equivalent PNOC/NPY populations?
How do PNOC/NPY neurons interact with existing appetite circuits (AgRP, POMC)?

Common questions

What are PNOC/NPY neurons?

These are newly identified brain cells in the hypothalamus that produce both prepronociceptin (PNOC) and neuropeptide Y (NPY)—two appetite-stimulating signals. They are different from the previously known AgRP/NPY neurons and represent a new pathway by which leptin controls appetite and body weight.

Could this lead to new weight loss drugs?

Potentially. Drugs that specifically target these PNOC/NPY neurons could suppress appetite through a completely new mechanism. Since restoring leptin signaling in these neurons dramatically reduced weight in obese mice, they represent a promising target for anti-obesity drug development.

Read the original research

Hypothalamic PNOC/NPY neurons constitute mediators of leptin-controlled energy homeostasis.

Cell, 188(13), 3550-3566.e22

View on PubMed ↗Publisher’s paper ↗

Citation

Solheim, Marie H; Stroganov, Sima; Chen, Weiyi; Subagia, P Sicilia; Bauder, Corinna A; Wnuk-Lipinski, Daria; Del Río-Martín, Almudena; Sotelo-Hitschfeld, Tamara; Beddows, Cait A; Klemm, Paul; Dodd, Garron T; Lundh, Sofia; Secher, Anna; Wunderlich, F Thomas; Steuernagel, Lukas; Brüning, Jens C. (2025). Hypothalamic PNOC/NPY neurons constitute mediators of leptin-controlled energy homeostasis.. Cell, 188(13), 3550-3566.e22. https://doi.org/10.1016/j.cell.2025.04.001