TGF- β1 Regulation of P-JNK and L-Type Calcium Channel Cav1.2 in Cortical Neurons

AbstractCentral nervous system (CNS) diseases can cause a series of neuronal lesions, which may be improved by the anti-apoptotic neuroprotection of transforming growth factor-beta 1 (TGF- β1). In neurons, L-type Ca2+ channels (LTCC) are mainly composed of Cav1.2 subunits. Given the implication of TGF- β1 in numerous CNS diseases, we examined the neuroprotective effects of TGF-β1 on the Cav1.2 channel in the CNS. To simulate acute mechanical traumatic brain injury (TBI), we used a needle to create parallel scratches across plates, which were cultured for 9 h. Meanwhile, Fluo4-AM-loaded laser sc anning confocal microscopy with a dual wavelength of 488 nm/530 nm was employed to determine intracellular calcium concentrations ([Ca2+]i). We found that MAPK inhibitors impede TGF- β1-induced cell viability and that TGF-β1 recovered from the trauma-induced cell viability in neurons. Cav1.2 production was significantly decreased in the TGF-β1-treated (10 ng/mL) neurons. At this TGF-β1 concentration, Cav1.2 was significantly down-regulated in a time-dependent manner after 1 2 h. Moreover, TGF-β1 partially recovered the protein levels of Cav1.2 that were reduced by TBI. TGF-β1 significantly inhibited the fluorescence intensity of [Ca2+]i increased by KCl and delayed the time of the peak [Ca2+]i. The observed effects of TGF- β1 on Cav1.2 were regulated by MAPK inhibitors. The observed effects of TGF-β1 on P-JNK were also impeded by pre-incubation with the LTCC inhibitor (...
Source: Journal of Molecular Neuroscience - Category: Neuroscience Source Type: research