Objective(s): Adrenomedullin (AM) has high expression in the spinal cord. In this study, we investigated the expression of AM and its receptor components, including calcitonin receptor-like receptor (CLR) and receptor activity modifying proteins (RAMPs) in dorsal root ganglion (DRG) and spinal motor (SM) neurons. Furthermore, the effects of AM on cAMP/cAMP response element-binding protein (CREB), AKT/glycogen synthase kinase-3 beta (GSK-3β ) signaling pathways, and expressions of brainderived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) were evaluated. Materials and Methods: Rat embryonic DRG and SM neurons were isolated, purified, and cultured. Real-time PCR was used to assess expressions of AM, CLR, and RAMPs. cAMP levels, p-CREB, BDNF, and NT-3 were determined using an enzyme-linked immunosorbent assay. p-AKT and p-GSK-3β levels were determined by western blotting. Real-time PCR showed expressions of AM, CLR, RAMP2, and RAMP3 in both DRG and SM neurons. Results: AM increased cAMP accumulation and p-CREB levels in DRG and SM neurons. AM increased p-AKT and p-GSK-3β in DRG, but not SM neurons. AM significantly increased BDNF expression in both DRG and SM neurons. There was also an increase in NT-3 level in both DRG and SM neurons, which is statistically significant in SM neurons. Conclusion: These results showed both DRG and SM neurons are targets of AM actions in the spinal cord. An increase in BDNF expression by AM in both DRG and SM neurons suggests the possible beneficial role of AM in protecting, survival, and regeneration of sensory and motor neurons.

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system (CNS), in which axonal damage is a deteriorative factor. Brain-Derived Neurotrophic Factor (BDNF) is described as a neuronal-survival gene, also capable of exerting pleiotropic effects on the immune cells. Here, we aimed to investigate expression levels of BDNF and its antisense RNA, BDNF-AS, in Iranian MS patients. Our case-control study was based on collecting 50 whole blood samples of relapsing-remitting MS patients and 50 healthy controls. Then, expression analysis of BDNF and BDNF-AS was performed by Real-time quantitative PCR. We found a strong and positive correlation between BDNF and BDNF-AS in MS patients. This is while no significant difference in BDNF and BDNF-AS expression levels was seen between MS patients and controls (p>0. 05). A significant and strong positive correlation was found between the expression levels of BDNF-AS and BDNF (r=0. 785, p<0. 0001). Further, significant positive moderate correlations of BDNF and BDNF-AS with other lncRNAs (GSTT1-AS1 and IFNG-AS1) and genes (TNF and IFNG) were revealed (p<0. 0001). Additionally, there was no correlation between the BDNF and BDNF-AS expressions and disease duration, age at onset, and Expanded Disability Status Scale of Kurtzke (EDSS) (p>0. 05). BDNF and BDNF-AS expression levels revealed insignificant discrepancies in patients and controls. We found a strong and positive correlation between BDNF and BDNF-AS in MS patients, which is, based on previous studies, a quit novel finding and can be further discussed by future works to unravel its possible application in MS. We suggest evaluation of different leukocytes subsets separately along with large cohort studies comprising a higher number of individuals from different ages to unravel the effects of other possible aspects.