Neuroprotection of muscarinic receptor agonist pilocarpine against glutamate-induced apoptosis in retinal neurons.
Neuroprotection offers potential as an alternative therapy for glaucoma. Pilocarpine, as a typical muscarinic receptor agonist, remains among the major intraocular pressure lowering drugs for the conventional treatment of glaucoma. However, whether pilocarpine also possesses neuroprotection against glutamate cytotoxicity in retinal neurons is still unknown. In rat primary retinal cultures, identification of neuron, cell viability, apoptosis, intracellular Ca(2+) concentration, mitochondrial membrane potential, gene expression were studied by immunofluorescence, MTT, High Content Scanning, confocal microscopy, reverse-transcription PCR, and western blot analysis, respectively. Pretreatment of pilocarpine could prevent glutamate-induced neuron death, which was blocked by the non-selective antagonist atropine and the M1-selective muscarinic receptor antagonist pirenzepine. The antiapoptotic effect of pilocarpine was associated with maintaining calcium homeostasis, recovering mitochondrial membrane potential, and regulating the expression of Bcl-2 and Caspase-3. These studies demonstrated that pilocarpine had effective protection against glutamate-induced neuronal apoptosis through M1 muscarinic receptor. The results may provide an insight into the new mechanism of glaucoma therapy that pilocarpine may potentially act as a retinal neuroprotectant.
Zhou
Wei
W
Department of Pharmacology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China.
Zhu
Xu
X
Zhu
Liang
L
Cui
Yong Yao
YY
Wang
Hao
H
Qi
Hong
H
Ren
Qiu Shi
QS
Chen
Hong Zhuan
HZ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D015870:Gene Expression / Q000187:drug effects; D005901:Glaucoma / Q000188:drug therapy* / Q000473:pathology; D018698:Glutamic Acid / Q000633:toxicity; D006706:Homeostasis / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018721:Muscarinic Agonists / Q000494:pharmacology*; D018696:Neuroprotective Agents / Q000494:pharmacology; D010862:Pilocarpine / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000187:drug effects*
D018721:Muscarinic Agonists; D018696:Neuroprotective Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D010862:Pilocarpine; D018698:Glutamic Acid; C505410:Casp3 protein, rat; D053148:Caspase 3; D002118:Calcium