Yu Ping, Zhou Wei, Liu Lu, Tang Ya-Bin, Song Yun, Lu Juan-Juan, Hou Li-Na, Chen Hong-Zhuan, Cui Yong-Yao
a Department of Pharmacology , Shanghai Jiao Tong University School of Medicine , Shanghai , China.
b Shanghai Research Institute of Stomatology, Shanghai Ninth People's Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China.
Curr Eye Res. 2017 Sep;42(9):1319-1326. doi: 10.1080/02713683.2017.1315142. Epub 2017 Jun 20.
Muscarinic acetylcholine receptor (mAChR) agonists have been used to treat glaucoma due to their intraocular pressure-lowering effects. Recently, it has been reported that retinal mAChRs activation can also stimulate neuroprotective pathways.
In our study, we evaluated the potential neuroprotective effect of L-satropane, a novel mAChR agonist, on retinal neuronal injury induced by cobalt chloride (CoCl) and ischemia/reperfusion (I/R).
CoCl-induced hypoxia injury in cultured cell models and I/R-induced retinal neuronal damage in rats in vivo were used to evaluate the abilities of L-satropane. In detail, we measured the occurrence of retinal pathological changes including molecular markers of neuronal apoptosis and Aβ expression.
Pretreatment with L-satropane protects against CoCl-induced neurotoxicity in PC12 and primary retinal neuron (PRN) cells in a dose-dependent manner by increasing retinal neuron survival. CoCl or I/R-induced cell apoptosis by upregulating Bax expression and downregulating Bcl-2 expression, which resulted in an increased Bax/Bcl-2 ratio, and upregulating caspase-3 expression/activity was significantly reversed by L-satropane treatment. In addition, L-satropane significantly inhibited the upregulation of Aβ production in both retinal neurons and tissue. We also found that I/R-induced histopathological retinal changes including cell loss in the retinal ganglion cell layer (GCL) and increased TUNEL positive retinal ganglion cells in GCL and thinning of the inner plexiform layer (IPL) and inner nuclear layer (INL) were markedly improved by L-satropane. The effects of L-satropane were largely abolished by the nonselective mAChRs antagonist atropine and M1-selective mAChR antagonist pirenzepine.
These results demonstrated that L-satropane might be effective in preventing retinal neuron damage caused by CoCl or I/R. The neuroprotective effects of L-satropane may be attributed to decreasing cell apoptosis and Aβ production through activation of M1 mAChR.
毒蕈碱型乙酰胆碱受体（mAChR）激动剂因其降低眼压的作用而被用于治疗青光眼。最近，有报道称视网膜mAChR的激活也能刺激神经保护途径。
在我们的研究中，我们评估了新型mAChR激动剂L-托烷对氯化钴（CoCl）和缺血/再灌注（I/R）诱导的视网膜神经元损伤的潜在神经保护作用。
使用培养细胞模型中CoCl诱导的缺氧损伤和体内大鼠I/R诱导的视网膜神经元损伤来评估L-托烷的能力。具体而言，我们测量了视网膜病理变化的发生情况，包括神经元凋亡的分子标志物和Aβ表达。
L-托烷预处理通过提高视网膜神经元存活率，以剂量依赖的方式保护PC12和原代视网膜神经元（PRN）细胞免受CoCl诱导的神经毒性。CoCl或I/R通过上调Bax表达和下调Bcl-2表达诱导细胞凋亡，导致Bax/Bcl-2比值增加，并上调caspase-3表达/活性，而L-托烷处理可显著逆转这种情况。此外，L-托烷显著抑制视网膜神经元和组织中Aβ产生的上调。我们还发现，L-托烷显著改善了I/R诱导的视网膜组织病理学变化，包括视网膜神经节细胞层（GCL）中的细胞丢失、GCL中TUNEL阳性视网膜神经节细胞增加以及内网状层（IPL）和内核层（INL）变薄。非选择性mAChR拮抗剂阿托品和M1选择性mAChR拮抗剂哌仑西平在很大程度上消除了L-托烷的作用。
这些结果表明，L-托烷可能有效预防CoCl或I/R引起的视网膜神经元损伤。L-托烷的神经保护作用可能归因于通过激活M1 mAChR减少细胞凋亡和Aβ产生。
