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 G; CAMPOS-MELO D; DROPPELMANN C; KELLER B; DE NICOLA A; GONZALEZ DENISELLE MC; VOLKENING K; STRONG MJ

New Orleans

Encuentro; 64th Annual Meeting of the American Academy of Neurology.; 2012

American Academy of Neurology

Expression and cellular localization of the classical progesterone receptor (PR) in the spinal cord of amyotrophic lateral sclerosis (ALS) patients Objective To determine the differential expression and cellular localization of isoforms A and B of the PR between controls and ALS-affected spinal cords. Background Progesterone is neuroprotective in the Wobbler mouse model of motor neuron degeneration. The effects of progesterone are mediated through the PR which regulates gene expression. Design/Methods Cervical and lumbar spinal cords were obtained from age-/sex-matched controls and sporadic ALS patients. We performed immunohistochemistry, immunofluorescence (IF) and semi-quantitative RT-PCR using these tissues. Antibodies and primers recognized either the PR A/B isoforms or the PR B isoform. IF was performed using markers of endothelium (VWF), reactive astrocytes (GFAP), phosphorylated high molecular weight neurofilament (SMI31), and motor neurons (NSE). Results No differential expression of PR A/B mRNA was observed in the cervical spinal cord between ALS (n=6) and controls (n=3), while significantly higher levels were observed at the lumbar level (p=0.04). In cervical and lumbar sections, PR B mRNA was 2-fold higher than in controls (p=ns). In both ALS (n=8) and controls (n=6) PR A/B immunoreactivity (IR) was found in large and small caliber vessels and axonal processes. IR in vessels consisted in endothelium and smooth muscle cells.  Motor neurons were occasionally stained at the border of the plasma membrane and axon hillock with increasing IR at the nerve roots. ALS patients presented with higher IR than controls in these structures, which further validated our mRNA expression observations. Using IF, we observed the same localization of PR A/B, whereas no expression was observed in astrocytes. PR B isoform was observed only in nuclei of endothelial and glial cells and also within motor neurons. Conclusions Both PR isoforms are present in human spinal cord and are up-regulated in ALS.  Blood vessles and nerve roots presented with the highest levels of IR. These findings suggest a role for PR in neo-vascularization, axonal integrity and myelination.