Transforming growth factor-beta: neuronal and glial expression in CNS degenerative diseases

We have previously shown that the brains of patients with Alzheimer's disease (AD) express transforming growth factor (TGF)-beta 2 in neurofibrillary tangle (NFT)-bearing neurons and reactive astrocytes. The present study was undertaken to determine whether other neurodegenerative diseases were also associated with an alteration of the TGF-beta's. The immunohistochemical expression of TGF-beta 1, -2 and -3 was assessed in the brains of patients with progressive supranuclear palsy (n = 2), amyotrophic lateral sclerosis (n = 3), Lewy body disease (n = 5), Parkinson's disease (n = 1), Shy-Drager syndrome (n = 1), Pick's disease (n = 3), lobar atrophy (n = 1), and corticobasal degeneration (n = 2). Our results were compared to norms for controls (n = 8). We found expression of TGF-beta 2 in both NFT bearing neurons and tangle-bearing glial cells in progressive supranuclear palsy and in neurons with age-related NFT formation. Widespread staining of reactive astrocytes for TGF-beta 2 was observed in all degenerative diseases. TGF-beta 1 and -3 staining was not selectively altered in these diseases. We conclude that induction of TGF-beta 2 may be an intrinsic part of the processes that underlie NFT formation and reactive gliosis in a variety of neurodegenerative diseases.