Kwon, Jea An, Heeyoung Sa, Moonsun Won, Joungha Shin, Jeong Im Lee, C. Justin 2024-01-20T02:30:43Z 2024-01-20T02:30:43Z 2021-09-01 2017-02 1226-2560 https://pubs.kist.re.kr/handle/201004/123159 Astrocytes are non-excitable cells in the brain and their activity largely depends on the intracellular calcium (Ca2+) level. Therefore, maintaining the intracellular Ca2+ homeostasis is critical for proper functioning of astrocytes. One of the key regulatory mechanisms of Ca2+ homeostasis in astrocytes is the store-operated Ca2+ entry (SOCE). This process is mediated by a combination of the Ca2+-store-depletion-sensor, Stim, and the store-operated Ca2+-channels, Orai and TrpC families. Despite the existence of all those families in astrocytes, previous studies have provided conflicting results on the molecular identification of astrocytic SOCE. Here, using the shRNA-based gene-silencing approach and Ca2+-imaging from cultured mouse astrocytes, we report that Stim1 in combination with Orai1 and Orai3 contribute to the major portion of astrocytic SOCE. Gene-silencing of Stim1 showed a 79.2% reduction of SOCE, indicating that Stim1 is the major Ca2+-store-depletion-sensor. Further gene-silencing showed that Orai1, Orai2, Orai3, and TrpC1 contribute to SOCE by 35.7%, 20.3%, 26.8% and 12.2%, respectively. Simultaneous gene-silencing of all three Orai subtypes exhibited a 67.6% reduction of SOCE. Based on the detailed population analysis, we predict that Orai1 and Orai3 are expressed in astrocytes with a large SOCE, whereas TrpC1 is exclusively expressed in astrocytes with a small SOCE. This analytical approach allows us to identify the store operated channel (SOC) subtype in each cell by the degree of SOCE. Our results propose that Stim1 in combination with Orai1 and Orai3 are the major molecular components of astrocytic SOCE under various physiological and pathological conditions. English KOREAN SOC BRAIN & NEURAL SCIENCE, KOREAN SOC NEURODEGENERATIVE DISEASE ALZHEIMERS-DISEASE CRAC CHANNEL RELEASE ACTIVATION COMPLEX MICE TRANSCRIPTOME PROTEINS DATABASE NEURONS Orai1 and Orai3 in Combination with Stim1 Mediate the Majority of Store-operated Calcium Entry in Astrocytes Article 10.5607/en.2017.26.1.42 1 EXPERIMENTAL NEUROBIOLOGY, v.26, no.1, pp.42 - 54 EXPERIMENTAL NEUROBIOLOGY 26 1 42 54 scie scopus kci ART002202505 000406862000005 2-s2.0-85013758248 Medicine, Research & Experimental Neurosciences Research & Experimental Medicine Neurosciences & Neurology Article ALZHEIMERS-DISEASE CRAC CHANNEL RELEASE ACTIVATION COMPLEX MICE TRANSCRIPTOME PROTEINS DATABASE NEURONS Astrocyte SOCE Stim1 Orai1 Orai3 TrpC1