Glial CellsMicroglial activation by the small heat shock protein, α-crystallinBhat, Narayan R.1,3; Sharma, Krishna K.2Author Information 1Department of Neurology, Medical University of South Carolina, Charleston, SC 29425 2Mason Eye Institute, Department of Ophthalmology, University of Missouri, Columbia, MO 65212, USA 3Corresponding Author: Narayan R. Bhat ACKNOWLEDGEMENTS: This study was supported by grants (RG2481 and RG2849) from the National Multiple Sclerosis Society. We thank Elaine Terry and Peisheng Zhang for their technical help and Sallie Bendt for excellent secretarial assistance. Received 6 July 1999; accepted 19 July 1999 NeuroReport: September 9, 1999 - Volume 10 - Issue 13 - p 2869-2873 Buy Abstract ACTIVATED microglia regulate immune and inflammatory responses in the CNS under a variety of stresses due to infection, injury and disease. In this study, we show that a stress-inducible small heat shock protein, α-crystallin, induces in vitro activation of microglia cultured from newborn rat brain. Exposure of microglia to α-crystallin resulted in an increased production of nitric oxide (NO) and the expression of the inducible NO synthase (iNOS) as determined by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses. α-Crystallin also stimulated the synthesis of the pro-inflammatory cytokine, TNFα. The results presented showing microglial induction of the two key immune regulatory and inflammatory molecules, i.e., NO and TNFα, in response to a stress-inducible protein, suggest a link between environmental stress and the CNS immune response. © 1999 Lippincott Williams & Wilkins, Inc.