Brain research
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Hairy and enhancer of split 1 (Hes1), a downstream target of Notch signaling, has long been recognized as crucial in inhibiting neuronal differentiation. However, the role of Hes1 following traumatic brain injury (TBI) in adult neurogenesis in the mouse dentate gyrus (DG) remains partially understood. Here, we investigate the role of Hes1 in regulating neurogenesis in the DG of the adult hippocampus after TBI by up- or downregulating Hes1 expression. ⋯ Second, downregulation of Hes1 via RNA interference (RNAi) results in a significant increase in neuronal production and promotes the differentiation of NPCs into mature neurons in the DG, as assessed by BrdU and NeuN double staining. Furthermore, a Morris water maze (MWM) test clearly confirmed that the knockdown of Hes1 improves the spatial learning and memory capacity of adult mice following injury. Taken together, these observations suggest that Hes1 represents a negative regulator of adult neurogenesis post-TBI and that the precise space-time regulation of Hes1 expression in the DG may promote the recovery of neural function following TBI.
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Activation of signal transducer and activator of transcription-3 (STAT3) is suggested to be critically involved in the development of chronic pain, but the complex regulation of STAT3-dependent pathway and the functional significance of inhibiting this pathway during the development of neuropathic pain remain elusive. To evaluate the contribution of the JAK2/STAT3 pathway to neuropathic pain and the potentiality of this pathway as a novel therapeutic target, we examined the effects of the STAT3 inhibitor WP1066 by intrathecal administration in a rat model of bilateral chronic constriction injury (bCCI). The pain behavior tests were performed before the surgery and on postoperative day 3, 7, 14 and 21. ⋯ Our results found that the JAK2/STAT3 pathway in the spinal cord dorsal horn was significantly activated in the bCCI neuropathic pain rats. WP1066, which inhibited the STAT3 pathway specifically, could partially alleviate the pain behavior of the bCCI rats. So it may serve as a novel therapeutic strategy against neuropathic pain.