Differential expression of fibroblast growth factor-2 and fibroblast growth factor receptor 1 in a scarring and nonscarring model of CNS injury in the rat

Injury to the adult brain results in abortive axon regeneration and the deposition of a dense fibrous glial scar. Therapeutic strategies to promote postinjury axon regeneration are likely to require antiscarring strategies. In neonatal brain wounds, scar material is not laid down and axons grow across the lesion site, either by de novo growth or regeneration. To achieve the therapeutic goal of recapitulating the nonscarring neonatal response in the injured adult, an understanding of how ontogenic differences in scarring reflect developmental diversities in the trophic response to injury is required. Fibrobast growth factor-2 (FGF-2) expression is developmentally regulated and has been implicated as a regulator of the wounding response of the adult rat central nervous system. We have investigated the expression of FGF-2 and fibroblast growth factor receptor 1 (FGFR1) after penetrating lesions to the cerebral cortex of 5 days post partum (dpp) (nonscarring) and 16 dpp and adult (scarring) rats. In situ hybridization, immunohistochemistry and Western blotting showed robust and sustained increases in FGF-2 and FGFR1 mRNA and protein in reactive astrocytes around the lesion in scarring rats, a response that was attenuated substantially in the nonscarring neonate. These results demonstrate that changes in astrocyte FGF-2 and FGFR1 expression are coincident with the establishment of a mature pattern of glial scarring after injury in the maturing central nervous system, but it is premature to infer a causal relationship without further experiments.

Coordination of fibroblast growth factor receptor 1 (FGFR1) and fibroblast growth factor-2 (FGF-2) trafficking to nuclei of reactive astrocytes around cerebral lesions in adult rats

Traumatic injury to the adult central nervous system initiates a cascade of cellular and trophic events, culminating in the formation of a reactive gliotic scar through which transected axons fail to regenerate. Levels of fibroblast growth factor-2 (FGF-2), a potent gliogenic and neurotrophic factor, together with its full-length receptor, FGF receptor 1 (FGFR1) are coordinately and significantly increased postinjury in both nuclear and cytoplasmic fractions of extracted cerebral cortex biopsies after a penetrant injury. FGFR1 is colocalized with FGF-2 in the nuclei of reactive astrocytes, and here FGF-2 is associated with nuclear euchromatin. This study unequivocally demonstrates coordinate up-regulation and trafficking of FGF-2 and full-length FGFR1 to the nucleus of reactive astrocytes in an in vivo model of brain injury, thereby implicating a role in nuclear activity for these molecules. However, the precise contribution of nuclear FGF-2/FGFR1 to the pathophysiological response of astrocytes after injury is undetermined.

Comparison of sotalol hydrochloride and methyldopa in essential hypertension

In a non-blind randomized comparison of sotalol hydrochloride and methyldopa in essential hypertension, the two drugs were equivocal in effect in reaching a preset hypotensive aim, in the maximum decreases from the baseline and in the mean reductions per week from the baseline. Milligram for milligram, sotalol was about twice as potent as methyldopa. No volunteered side-effects were noted for methyldopa; 3/19 for sotalol.