In vitro Studie zur neurotrophen Wirkung des Augenlinsen-Proteins BetaH-Kristallin auf Motoneurone des embryonalen Hühnchens (Gallus gallus)

AbstractCrystallins are water soluble proteins expressed abundantly in the eye lens, where their cell-protective function is known. In the first part of this study, it was examined whether different HPLC-fractions of lenticular crystallins exert an increase of neurite outgrowth in the organotypically cultured spinal cord. Next, different concentrations of HPLC-fractionated lens proteins from the rat were compared to the neurotrophic factors NGF, CNTF and NT-4. It was shown here that all mammalian crystallins promote an increase in neurite outgrowth of spinal neurites in vitro. The a- and bH-crystallin fractions had the greatest maximal neurotrophic effect of all the crystallins and their effect was comparable to NGF and NT-4 in organotypic chick spinal cord culture. In the second part of this study the bH-crystallin was tested on dissociated spinal motor neurons. bH-crystallin promoted a direct increase of neurite length in motor neurons without involvement of microglia or macrophages. In the third part of this study it was determined if bB1-crystallin, a dominant subunit of bH-crystallin, showed a similar effect. Motor neurons in single cell culture were treated with recombinant human wildtype bB1-crystallin and it was found, that wildtype bB1-crystallin alone exerted the same growth promoting effect as the whole bH-crystallin fraction.