Nesfatin colocalization of other neuropeptide in mouse
Klaudia Sípos1, Rege Sugárka Papp1, Katalin Könczöl1, Dorina Guba1, Csaba Fekete1, Ferenc Erdélyi1, Máté Durst1, Zsuzsanna E Tóth1
Nesfatin-1 is a neurotransmitter derived from the nucleobindin 2 (NUCB2) precursor molecule. Nesfatin-1/NUCB2 (nesfatin) is widely distributed in the hypothalamus, and it is important in regulating the energy homeostasis, food and water intake and the stress response. Coexpression of nesfatin with different neuropeptides in the hypothalamus is well characterized in rats, but not in mice. Additionally, the exact role of nesfatin in the individual cell types is not known. We used double fluorescence immunohistochemistry to map and quantify coexpression of nesfatin with oxytocin in the supraoptic (SON) and paraventricular nuclei (PVN), as well as with proopiomelanocortin (POMC) in the arcuate nucleus (ARC) in mice. Additionally, to study the physiological role of nesfatin in the POMC neurons, we generated a Tg(POMC-cre) / nesfatin-1 LOXPflox mouse model, by floxing the NUCB2 gene at the 3rd exon and breeding the females with Tg (POMC-cre) males. Nesfatin was highly coexpressed with oxytocin both in the SON and PVN. Coexpression of POMC and nesfatin in the ARC was less abundant. Phenotype of Tg(POMC-cre) /nesfatin-1 LOXPflox mice was validated by double immunohistochemistry and showed the lack of nesfatin expression in the POMC neurons in the ARC in the homozygous floxed animals. The bodyweight and food intake of mice lacking nesfatin-1 in the POMC neurons did not alter significantly form controls, however preliminary results suggested that females lost less weight after 24h food deprivation compared to non-knock out littermates. The results suggest that nesfatin-1 in POMC cells may be important in the regulation of the energy homeostasis.