Expression and cellular localization of the classical progesterone receptor (PR) in the spinal cord of control subjects and amyotrophic lateral sclerosis (ALS) patients

GARGIULO MONACHELLI GM; CAMPOS MELO D; DROPPELMANN C; KELLER B; DE NICOLA AF; GONZALEZ DENISELLE M.C; VOLKENING K; STRONG MJ

Congreso; 64th Annual Meeting of the American Academy of Neurology; 2012

Objective: To determine the differential expression and cellular localization of the A and B isoforms of the PR (PRA, PRB) between control subjects and ALS affected spinal cords. Background: Progesterone is neuroprotective in the Wobbler mouse model of motor neuron degeneration and in traumatic CNS injury. The effects of progesterone are, in part, mediated by the PR which regulates gene expression. Design/Methods: The cervical and lumbar regions of spinal cords were obtained from age-/sex-matched controls and sporadic ALS patients. In these regions, we performed immunohistochemistry, immunofluorescence (IF) and semi-quantitative RT-PCR analysis. We used antibodies and primers recognizing both PRA+B or PRB only. IF was performed in PRA+B and using markers of endothelium (VWF), reactive astrocytes (GFAP), phosphorylated high molecular weight neurofilaments (SMI31) and neurons (NSE). Results: PRA+B mRNA expression at the lumbar level was significantly higher in ALS (n=6) than controls (n=3, p=0.04), whereas expression was similar in the cervical cord. In both spinal sections, PRB mRNA was 2-fold higher in ALS (p=ns). In ALS (n=9) and controls (n=7) PRA+B immunoreactivity (IR) was found in large caliber vessels and axonal processes. In vessels, IR was localized in endothelium and smooth muscle cells. Motor neurons were occasionally stained at the border of the plasma membrane and axon hillock but increased IR was found in the nerve roots. ALS patients presented higher IR than controls in these structures, in agreement with our mRNA data. Using IF, we observed the same localization of PRA+B, whereas no expression was observed in astrocytes. PRB was only observed in nuclei of endothelium and glia and also within some motor neurons. Conclusions: Both PR isoforms are present in human spinal cord and are possibly up-regulated in ALS. Blood vessels and nerve roots presented with the highest levels of IR. These findings suggest that PR may have a role in neo-vascularization, axonal integrity and myelination in ALS.