title: Silencing TRPM7 in mouse cortical astrocytes impairs cell proliferation and migration via ERK and JNK signaling pathways.
abstract: Transient receptor potential melastatin 7 (TRPM7), a non-selective cation channel, is highly expressed expressed in the brain and plays a critical role in ischemic neuronal death. Astrocyte, the most abundant cell type in central nervous system (CNS), exerts many essential functions in the physiological and pathological conditions. Here we investigated the expression and functions of the TRPM7 channel in mouse cortical astrocytes. Using reverse transcription (RT)-PCR, immunostaining, western blot and patch clamp recording, we showed that functional TRPM7 channel is expressed in cultured mouse cortical astrocytes. Knocking down TRPM7 with specific siRNA impairs the proliferation and migration of astrocytes by 40.2% ± 3.9% and 40.1% ± 11.5%, respectively. Consistently, inhibition of TRPM7 with 2-aminoethoxydiphenyl borate (2-APB) also decreases astrocyte proliferation and migration by 46.1% ± 2.5% and 64.2% ± 2.4%. MAPKs and Akt signaling pathways have been shown to be implicated in TRPM7-mediated responses including cell proliferation and migration. Our data show that suppression of TRPM7 in astrocytes reduces the phosphorylation of extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinases (JNK), but not p38 mitogen-activated protein kinase and Akt. In addition, TRPM7, as a cation channel, has been involved in the Ca²⁺ and Mg²⁺ homeostasis in several types of cells. In our study, we found that silencing TRPM7 decreases the intracellular basal Mg²⁺ concentration without affecting Ca²⁺ concentration in astrocytes. However, an addition of Mg²⁺ to the growth medium could not rescue the impaired proliferation of astrocytes. Together, our data suggest that TRPM7 channel may play a critical role in the proliferation and migration of astrocytes via the ERK and JNK pathways.
authors: Cyrus Tang Hematology center, Collaborative Innovation Center of Hematology, MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Key Lab of Preventive and translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu, China.
authors: Zhao
authors: Z
authors: Zeng
authors: Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States of America.
authors: Tiandong
authors: T
authors: Leng
authors: Membrane Channel Research Laboratory and Key Laboratory for Applied Statistics of MOE, Northeast Normal University, Changchun, P.R. China.
authors: Xuechao
authors: X
authors: Feng
authors: Department of Cardiology, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors: Huawei
authors: H
authors: Sun
authors: Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States of America.
authors: Koichi
authors: K
authors: Inoue
authors: Cyrus Tang Hematology center, Collaborative Innovation Center of Hematology, MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Key Lab of Preventive and translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu, China.
authors: Li
authors: L
authors: Zhu
authors: Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States of America.
authors: Zhi-Gang
authors: ZG
authors: Xiong
mesh_terms: D000818:Animals; D017209:Apoptosis; D001253:Astrocytes / Q000166:cytology* / Q000378:metabolism; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D057809:HEK293 Cells; D006801:Humans; D007124:Immunoenzyme Techniques; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D050053:TRPM Cation Channels / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; D050053:TRPM Cation Channels; C421903:Trpm7 protein, mouse; D017346:Protein Serine-Threonine Kinases; C486583:TRPM7 protein, human; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D002118:Calcium