Transforming Growth Factor-β: 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)-β2 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-β's. The immunohistochemical expression of TGF-β1, -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-β2 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-β2 was observed in all degenerative diseases. TGF-β1 and -3 staining was not selectively altered in these diseases. We conclude that induction of TGF-β2 may be an intrinsic part of the processes that underlie NFT formation and reactive gliosis in a variety of neurodegenerative diseases.