Abstract
Nesfatin-1, an anorexic nucleobindin-2 (NUCB2)-derived hypothalamic peptide, controls appetite and energy metabolism. Recent studies show that nesfatin-1/NUCB2 is expressed not only in the brain but also in gastric and adipose tissues. Thus, we investigated the distributions of nesfatin-1/NUCB2 in various tissues of male and female mice by real-time PCR, western blotting, and immunohistochemical staining. Real-time PCR analyses showed that NUCB2 mRNA was predominantly expressed in the pituitary and at lower levels in the hypothalamus, spleen, thymus, heart, liver, and muscle of both male and female mice. Expression was much higher in reproductive organs, such as the testis, epididymis, ovary, and uterus, than in the hypothalamus. Western blot analysis of the nesfatin-1 protein level showed similar results to the real-time PCR analyses in both male and female mice. These results suggest that nesfatin-1/NUCB2 have widespread physiological effects in endocrine and non-endocrine organs. In addition, immunohistochemical staining revealed that nesfatin-1 was localized in interstitial cells, including Leydig cells and in the columnar epithelium of the epididymis. Nesfatin-1 was also expressed in theca cells and interstitial cells in the ovary and in epithelial cells of the endometrium and uterine glands in the uterus. These results suggest that nesfatin-1 is a novel potent regulator of steroidogenesis and gonadal function in male and female reproductive organs. Further studies are required to elucidate the functions of nesfatin-1 in various organs of male and female mice.