Enhanced expression of nesfatin/nucleobindin-2 in white adipose tissue of ventromedial hypothalamus-lesioned rats

Abstract

Nesfatin-1, an anorexigenic protein, is ubiquitously expressed in the body. However, the exact mechanism underlying the in vivo regulation of production of nesfatin/nucleobindin-2 (NUCB2), a precursor protein of nesfatin-1, is unknown. We investigated the influence of modulation of autonomic nerve activity by a ventromedial hypothalamus (VMH) lesion and the subsequent effect on nesfatin/NUCB2 production in rat tissues innervated by the peripheral nervous system. Nesfatin/NUCB2 is strongly expressed in the pancreas and liver, moderately expressed in subcutaneous and visceral fat tissues and interscapular brown adipose tissue (iBAT), but is weakly expressed in the skeletal muscles. Our study results showed that the VMH lesion in VMH-lesioned rats did not affect nesfatin/NUCB2 expression in the pancreas, liver, skeletal muscle, and iBAT; however, the protein expression was significantly high in both subcutaneous and visceral fat tissues. In addition, continuous peripheral administration of carbachol for 5 days did not affect nesfatin/NUCB2 expression, but chemical sympathectomy using 6-hydroxydopamine mimicked the effect of VMH lesion by showing significantly high nesfatin/NUCB2 expression in the subcutaneous fat tissues. These results show that VMH lesion can modulate the autonomic nervous system activity and balance and increase nesfatin/NUCB2 expression in white adipose tissues of rats. Further, this action may be mediated via inhibition of the sympathetic nerve activity.