Wanhui Lin1,2, Wenli Huang1, Shenggen Chen1, Mingxing Lin3, Qingyu Huang1, Huapin Huang4. 1. Department of Neurology, Fujian Medical University Union Hospital, Fuzhou, China. 2. Department of Geriatrics, Fujian Medical University Union Hospital, Fuzhou, China. 3. Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China. 4. Department of Neurology Fujian Medical University Union Hospital, Fujian Key Laboratory of Molecular Neurology, Fuzhou, China.
Abstract
OBJECTIVE: Our primary objective is to verify whether 5-HTR6 is involved in the development of mossy fiber sprouting (MFS), and to determine how the progression of MFS is affected by 5-HTR6. METHODS: A total of 90 male adult Sprague-Dawley rats were allocated into either the control group (n=36) or the epileptic group (n=54). Status epilepticus (SE) of rats was induced by the intraperitoneal (i.p.) injection of LiCl-pilocarpine. We conducted our experiments in two stages. The first stage involves equally dividing 36 epileptic rats into three groups with treatments of none, 5-HTR6 antagonist SB-27104 (SB) and vehicle DMSO. Then behavior and electroencephalogram (EEG) of rats were monitored by video-EEG. The second stage involves dividing 126 epileptic rats into seven groups with treatments of none, 10% DMSO, SB (100 µg/kg), Fyn antagonist PP2 (50 µg/kg), p-ERK1/2 antagonist PD-98059 (30 µg/kg), SB (100 µg/ kg) + PP2 (50 µg/kg); SB (100 µg/kg) + PD-98059 (30 µg/kg). We also treated 18 rats in the control group of the first stage with 100 µg/kg 5-HTR6 agonist WAY-181187 (WAY). MFS of rats was detected through the approach of Timm's staining. Finally, expressions of 5-HTR6, Fyn, p-ERK1/2 and GAP-3 were qualified and semi-quantified via western blotting or RT-PCR. RESULTS: Induction of SE could stimulate formation of MFS and increased GAP-43 expressions. Expressions of 5-HTR6, Fyn and p-ERK1/2 were also up-regulated with increasing time after establishment of SE models. The development of MFS was remarkably inhibited by SB, PP2 and PD. Compared to the single antagonist, such an inhibitory effect was enhanced by SB+PD or SB+PP. Moreover, treatment of healthy rats with WAY would contribute to up-regulated Fyn and p-ERK1/2 expressions, as well as development of MFS (P < 0.05). Suppression of Fyn triggered a down-regulating trend of p-ERK1/2 (P < 0.05), however, suppressed p-ERK1/2 did not have such a significant effect on Fyn expression. CONCLUSION: HTR6 may affect the progression of MFS by activating both p-ERK1/2 and Fyn, which further modulate the expression of GAP-43.
OBJECTIVE: Our primary objective is to verify whether 5-HTR6 is involved in the development of mossy fiber sprouting (MFS), and to determine how the progression of MFS is affected by 5-HTR6. METHODS: A total of 90 male adult Sprague-Dawley rats were allocated into either the control group (n=36) or the epileptic group (n=54). Status epilepticus (SE) of rats was induced by the intraperitoneal (i.p.) injection of LiCl-pilocarpine. We conducted our experiments in two stages. The first stage involves equally dividing 36 epilepticrats into three groups with treatments of none, 5-HTR6 antagonist SB-27104 (SB) and vehicle DMSO. Then behavior and electroencephalogram (EEG) of rats were monitored by video-EEG. The second stage involves dividing 126 epilepticrats into seven groups with treatments of none, 10% DMSO, SB (100 µg/kg), Fyn antagonist PP2 (50 µg/kg), p-ERK1/2 antagonist PD-98059 (30 µg/kg), SB (100 µg/ kg) + PP2 (50 µg/kg); SB (100 µg/kg) + PD-98059 (30 µg/kg). We also treated 18 rats in the control group of the first stage with 100 µg/kg 5-HTR6 agonist WAY-181187 (WAY). MFS of rats was detected through the approach of Timm's staining. Finally, expressions of 5-HTR6, Fyn, p-ERK1/2 and GAP-3 were qualified and semi-quantified via western blotting or RT-PCR. RESULTS: Induction of SE could stimulate formation of MFS and increased GAP-43 expressions. Expressions of 5-HTR6, Fyn and p-ERK1/2 were also up-regulated with increasing time after establishment of SE models. The development of MFS was remarkably inhibited by SB, PP2 and PD. Compared to the single antagonist, such an inhibitory effect was enhanced by SB+PD or SB+PP. Moreover, treatment of healthy rats with WAY would contribute to up-regulated Fyn and p-ERK1/2 expressions, as well as development of MFS (P < 0.05). Suppression of Fyn triggered a down-regulating trend of p-ERK1/2 (P < 0.05), however, suppressed p-ERK1/2 did not have such a significant effect on Fyn expression. CONCLUSION:HTR6 may affect the progression of MFS by activating both p-ERK1/2 and Fyn, which further modulate the expression of GAP-43.
Authors: Guillermo González-H; Itzel Jatziri Contreras-García; Karla Sánchez-Huerta; Claudio M T Queiroz; Luis Ricardo Gallardo Gudiño; Julieta G Mendoza-Torreblanca; Sergio R Zamudio Journal: Brain Sci Date: 2020-09-11