Ganaxolone enhances microglial clearance activity and promotes remyelination in focal demyelination in the corpus callosum of ovariectomized rats
Ganaxolone enhances microglial clearance activity and promotes remyelination in focal demyelination in the corpus callosum of ovariectomized rats
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DOI：
10.1111/cns.13195
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发表时间：
2019-07-22
影响因子：
5.5
通讯作者：
Kalakh, Samah
中科院分区：
文献类型：
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作者：
Mouihate, Abdeslam;Kalakh, Samah
目的实验研究表明，孕酮代谢物异孕酮具有早髓鞘作用。这些早髓鞘作用的机制尚不清楚。因此，我们探讨了异孕酮的合成类似物加那洛酮对去卵巢大鼠胼胝体局灶性脱髓鞘后的再髓鞘形成和小胶质细胞激活的影响。方法去卵巢的成年大鼠在胼胝体中立体定向注射1%溶卵磷脂溶液2 μ L，然后每日注射加那洛酮（腹腔注射[i.p.p]）。], 2.5 mg/kg)或车辆。脱髓鞘损伤后3和7天，采用Luxol快速蓝染色和透射电镜观察脱髓鞘病变。Western blot检测髓磷脂蛋白（MBP， MAG， MOG, CNPase）的表达水平。采用免疫荧光染色（Iba1, dMBP， GFAP）和多重酶联免疫吸附测定（IL-1 β, tnf - α, IL-4, IL-10, IL-6）评估炎症反应和受损髓磷脂的清除。结果全身加那洛酮可促进溶卵磷脂诱导的脱髓鞘再生，上调髓磷脂主要蛋白的表达，增强受损髓磷脂的小胶质细胞清除。星形细胞增生以及局部产生的促炎和抗炎细胞因子不受加那洛酮治疗的影响。结论加那索龙对去卵巢大鼠胼胝体局灶性脱髓鞘有促进髓鞘再生的作用。这种作用至少部分是通过增强髓鞘碎片的小胶质细胞清除介导的，这为成功的髓鞘再生过程创造了有利的环境。
Aim Experimental studies have shown that the progesterone metabolite, allopregnanolone, is endowed with promyelinating effects. The mechanisms underlying these promyelinating effects are not well understood. Therefore, we explored the impact of allopregnanolone's synthetic analogue, ganaxolone, on remyelination and microglial activation following focal demyelination in the corpus callosum of ovariectomized rats. Methods Ovariectomized adult Sprague Dawley rats received a stereotaxic injection of 2 mu L of 1% lysolecithin solution in the corpus callosum followed by daily injections of either ganaxolone (intraperitoneal injection [i.p.], 2.5 mg/kg) or vehicle. The demyelination lesion was assessed 3 and 7 days postdemyelination insult using Luxol fast blue staining and transmission electron microscopy. The expression levels of myelin proteins (MBP, MAG, MOG, CNPase) were explored using Western blot. The inflammatory response and clearance of damaged myelin were evaluated using immunofluorescent staining (Iba1, dMBP, GFAP) and multiplex enzyme-linked immunosorbent assay (IL-1 beta, TNF-alpha, IL-4, IL-10, IL-6). Results Systemic administration of ganaxolone promoted remyelination of lysolecithin-induced demyelination, upregulated the expression of major myelin proteins, and enhanced microglial clearance of damaged myelin. Astrocytosis, as well as locally produced pro- and antiinflammatory cytokines, was not affected by ganaxolone treatment. Conclusion Ganaxolone promotes remyelination in response to focal demyelination of the corpus callosum of ovariectomized rats. This effect is, at least in part, mediated by enhancing microglial clearance of myelin debris, which creates a conducive environment for a successful remyelination process.