Distribution of stomatin expressing in the central nervous system and its up-regulation in cerebral cortex of rat by hypoxia

Abstract

Stomatin is an important membrane raft protein which can combine skeleton protein, some ion channel, and transporter to regulate their functions. However, until now no data on its expression and function in CNS are available. In this study, we examined distribution of stomatin in CNS of rat, and investigated the effects of hypoxia exposure and glucocorticoid on stomatin expression in cerebral cortex of rat. Immunofluorescence staining revealed a broad expression of stomatin protein in many areas of adult rat brain and spinal cord, including the ventral horn of spinal cord, causal magnocellular nucleus of hypothalamus, the V layer of the cerebral cortex, solitary nucleus, 10 and 12 nuclei, and so on. Hypoxia or ischemic hypoxia significantly up-regulated stomatin expression in cerebral cortex, and the up-regulation was independent on adrenocortical steroids since it also occurred in adrenalectomized (ADX) rats. Moreover, treatment of ADX or sham-operated rats with dexamethasone, a synthetic glucocorticoid alone could significantly stimulate expression of stomatin in lung and heart, but not in cerebral cortex. However, dexamethasone could enhance the hypoxia-stimulated expression of stomatin in cerebral cortex of ADX rats. These findings suggested that stomatin might be involved in various physiological functions and cellular events of neurons in CNS under physiological conditions and play a potential protective role under hypoxic conditions.