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Background It has been found that fluoride may cause cell damage by inducing intracellular calcium overload. Store-operated calcium entry (SOCE) plays an important role in maintaining intracellular calcium homeostasis, but the effect of fluoride on renal SOCE is unknown. Objective To explore the renal toxicity and the expression levels of the key proteins of SOCE, stromal interaction molecule 1 (STIM1) and calcium release-activated calcium modulator 1 (ORAI1) in the kidney tissues of mice exposed to fluoride subchronically. Methods Twenty male ICR mice were randomly divided into four groups with five mice in each group, including 0 (control group), 0.3, 3, and 30 mg·L−1 fluoride groups. The mice were given drinking water containing designed fluoride for 12 weeks. Body weight and liver and kidney organ coefficients of the mice were measured after the exposure; histopathological changes of the mouse kidney were observed; 24 h urine was collected at the end of 12 weeks of exposure to determine the levels of urine creatinine (UCr), urine calcium (UCa), albumin (ALB), and β2-microglobulin (β2-MG); the protein expression levels of STIM1 and ORAI1 in the kidney were detected by Western blotting; the fluorescence co-localization of STIM1 and ORAI1 was used to further verify the expression levels of STIM1 and ORAI1. Results After the exposure, there were no differences in body weight as well as liver and kidney organ coefficients among the groups (P > 0.05). Under optical microscope, the renal tubular cell showed degeneration, apical protrusion, shedding, and dilation in the 3 and 30 mg·L−1 fluoride groups. There was no statistical difference in UCr among the mice in each group (P > 0.05). Compared with the control group, the levels of UCa adjusted by UCr in the 3 and 30 mg·L−1 fluoride groups were (0.075±0.014) and (0.081±0.012) mol·mol−1 (represent by UCr per mol), which had a rising trend but showed no statistical difference. No difference was identified in the level of ALB among the groups (P > 0.05). The levels of β2-MG showed difference in different exposure groups, and the level of urine β2-MG in the 30 mg·L−1 fluoride group was (0.077±0.014) g·mol−1, higher than that in the control group (P<0.05). Based on the results of Western blotting, the protein expression levels of STIM1 and ORAI1 showed significant differences among the groups (F=18.411, 6.853; P=0.001, 0.013); compared with the control group, the expression levels of STIM1 protein increased in the 3 and 30 mg·L−1 fluoride groups (P < 0.05), and the protein expression level of ORAI1 in the 30 mg·L−1 fluoride group was increased (P < 0.05). The fluorescence co-localization results of STIM1 and ORAI1 showed that the expressions of STIM1 and ORAI1 were up-regulated in the 3 and 30 mg·L−1 fluoride groups. Conclusion Subchronic exposure to fluoride through drinking water can up-regulate the expression levels of STIM1 and ORAI1 in renal tissues and induce renal injury.
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Stromal interaction molecule 1 (STIM1) is a sensor of calcium ions in the intracellular calcium store. It is mainly distributed on the membranes of the endoplasmic reticulum in the form of dimers. It is expressed in various cells, such as nerve cells, skeletal muscle cells, myocardial cells, epithelial cells, endothelial cells and immune cells. Its function is mainly to regulate the opening and closing of the store-operated calcium entry channels. It can affect the concentration of calcium ions, the intracellular second messenger, and regulate various cellular physiological functions, such as cell secretion, proliferation, gene transcription, differentiation, apoptosis, migration and adhesion. A series of studies have shown that STIM1 not only is associated with the malignant behaviors of tumor cells, such as proliferation, apoptosis, invasion and metastasis, but also activates the switch of immune cells in the body. What's more, it plays an important role in cardiovascular diseases and vital organ damage. Based on the structural characteristics, mechanism of action and function of STIM1, this paper is intended to elucidate its relationships with tumors, immune system diseases, cardiovascular diseases and other diseases with the hope of providing reference for the prevention and treatment of related diseases.
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Stromal interaction molecule 1 (STIM1) is a transmembrane protein of the endoplasmic reticulum (ER) , a Ca2+ transducer in ER that activates the store-operated calcium channel.Through Orai1 protein, STIM1 adjusts the intracellular and extracellular calcium concentration.This way is called a store-operated Ca2+ entry.STIM1 plays a key role in phenotypic transformation of vascular smooth muscle cells, proliferation of endothelial cells, myocardial hypertrophy and myocardial fibrosis to regulate lots of cardiovascular diseases, such as atherosclerosis, congestive heart failure and systemic hypertension.STIM1 is closely related to cardiovascular diseases through calcium signal.The research progress of STIM1 in cardiovascular diseases is mainly discussed in this article.
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BACKGROUND/AIMS: We investigated the role of representative endoplasmic reticulum proteins, stromal interaction molecule 1 (STIM1), and store-operated calcium entry-associated regulatory factor (SARAF) in pacemaker activity in cultured interstitial cells of Cajal (ICCs) isolated from mouse small intestine. METHODS: The whole-cell patch clamp technique applied for intracellular calcium ions ([Ca²+]i) analysis with STIM1 or SARAF overexpressed cultured ICCs from mouse small intestine. RESULTS: In the current-clamping mode, cultured ICCs displayed spontaneous pacemaker potentials. External carbachol exposure produced tonic membrane depolarization in the current-clamp mode, which recovered within a few seconds into normal pacemaker potentials. In STIM1-overexpressing cultured ICCs pacemaker potential frequency was increased, and in SARAF-overexpressing ICCs pacemaker potential frequency was strongly inhibited. The application of gadolinium (a non-selective cation channel inhibitor) or a Ca2+-free solution to understand Orai channel involvement abolished the generation of pacemaker potentials. When recording intracellular Ca²+ concentration with Fluo 3-AM, STIM1-overexpressing ICCs showed an increased number of spontaneous intracellular Ca²+ oscillations. However, SARAF-overexpressing ICCs showed fewer spontaneous intracellular Ca2+ oscillations. CONCLUSION: Endoplasmic reticulum proteins modulated the frequency of pacemaker activity in ICCs, and levels of STIM1 and SARAF may determine slow wave patterns in the gastrointestinal tract.
Subject(s)
Animals , Mice , Calcium , Carbachol , Endoplasmic Reticulum , Gadolinium , Gastrointestinal Motility , Gastrointestinal Tract , Interstitial Cells of Cajal , Intestine, Small , Ions , MembranesABSTRACT
Studies have shown that stromal interaction molecule 1(STIM1) is closely related to the development of tumors, and which is involved in the regulation of apoptosis, proliferation, migration and invasion in many human cancers. Blocking or knockdown of STIM1 can significantly inhibit the proliferation and migration of cancer cells. Elucidation of the regulatory mechanism of STIM1 in cancer cells will be helpful for the identification of new therapeutic targets. This paper reviews the mechanism of STIM1 molecule in different tumors and its clinical application.
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AIM:To investigate the interaction of Ca 2+-sensing proteins , stromal interaction molecule 1 (STIM1) and calcium release-activated calcium channel protein 1 (Orai1), in Ca2+-sensing receptor (CaSR)-mediated extracellular Ca2+ influx and production of nitric oxide ( NO).METHODS: Human umbilical vein endothlial cells (HUVECs) were incubated with CaSR agonist spermine [activating store-operated calcium channels (SOC) and receptor-operated calcium channels ( ROC) ] alone or combined with CaSR negative allosteric modulator Calhex 231+ROC analogue TPA (activating ROC, blocking SOC), protein kinase C (PKC) inhibitor Ro 31-8220, or PKCα/β1 selective inhibitor Go 6976 (activate SOC, blocking ROC).The protein expression of STIM1 and Orai1 was determined by the method of immu-nofluorescence .The interaction between STIM 1 and Orai1 was examined by co-immunoprecipitation .The second to third passages of HUVECs were divided into STIM 1 and Orai1 short hairpin RNA group ( shSTIM1+shOrai1 group ) , vehicle-STIM1+vehicle-Orai1 group and control group , and then incubated with the 4 different treatments above .The intracellular Ca2+concentration ( [ Ca2+] I ) was detected using the fluorescent Ca 2+indicator Fura-2/AM.The production of NO was also determined by DAF-FM DA fluorescent probe .RESULTS:The protein expression of STIM 1 and Orai1 was located in the cytoplasm.Compared with control group , the localization of STIM1 and Orai1 in the cytoplasm was reduced after the HUVECs were incubated with Calhex 231+TPA, Ro 31-8220 or Go 6976, and the interaction of STIM1 and Orai1 was de-creased significantly .The [ Ca2+] I and the net NO fluorescence intensity in shSTIM 1+shOrai1 group were significantly re-duced after the 4 different treatments (P<0.05).CONCLUSION:STIM1 and Orai1 are components of SOC and ROC in store-and receptor-operated Ca 2+entry and NO generation .
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AIM:To investigate the interaction of Ca 2+-sensing proteins , stromal interaction molecule 1 (STIM1) and calcium release-activated calcium channel protein 1 (Orai1), in Ca2+-sensing receptor (CaSR)-mediated extracellular Ca2+ influx and production of nitric oxide ( NO).METHODS: Human umbilical vein endothlial cells (HUVECs) were incubated with CaSR agonist spermine [activating store-operated calcium channels (SOC) and receptor-operated calcium channels ( ROC) ] alone or combined with CaSR negative allosteric modulator Calhex 231+ROC analogue TPA (activating ROC, blocking SOC), protein kinase C (PKC) inhibitor Ro 31-8220, or PKCα/β1 selective inhibitor Go 6976 (activate SOC, blocking ROC).The protein expression of STIM1 and Orai1 was determined by the method of immu-nofluorescence .The interaction between STIM 1 and Orai1 was examined by co-immunoprecipitation .The second to third passages of HUVECs were divided into STIM 1 and Orai1 short hairpin RNA group ( shSTIM1+shOrai1 group ) , vehicle-STIM1+vehicle-Orai1 group and control group , and then incubated with the 4 different treatments above .The intracellular Ca2+concentration ( [ Ca2+] I ) was detected using the fluorescent Ca 2+indicator Fura-2/AM.The production of NO was also determined by DAF-FM DA fluorescent probe .RESULTS:The protein expression of STIM 1 and Orai1 was located in the cytoplasm.Compared with control group , the localization of STIM1 and Orai1 in the cytoplasm was reduced after the HUVECs were incubated with Calhex 231+TPA, Ro 31-8220 or Go 6976, and the interaction of STIM1 and Orai1 was de-creased significantly .The [ Ca2+] I and the net NO fluorescence intensity in shSTIM 1+shOrai1 group were significantly re-duced after the 4 different treatments (P<0.05).CONCLUSION:STIM1 and Orai1 are components of SOC and ROC in store-and receptor-operated Ca 2+entry and NO generation .
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Aim To investigate the effect of store-oper-ated calcium channel( SOCC) on autophagy in rat arte-rial smooth muscle cells A7 R5 . Methods Lentiviruses containing STIM1 or Orai1 gene were packaged in 293 T cells and then were used to infect rat arterial smooth muscle cells A7 R5 . The expression levels of STIM1 , Orai1 and Beclin 1 , a critical autophagy-regu-lating protein, of lentivirus-infected A7R5 cells, were detected by Western-blot. Autophagy in lentivirus-in-fected A7 R5 cells was induced by starvation or rapamy-cin, an inhibitor of mammalian target of rapamycin ( mTOR ) . Autophagy marker LC3 of these cells was detected by Western-blot. Results The constructions of vector pLV-STIM1 and pLV-Orai1 were confirmed by restriction enzymes digestion analysis. Compared with the control group, expressions of STIM1 or Orai1 protein was significantly increased after lentivirusLV-STIM1 and LV-Orai1infection, whereas the expressions of autophagy related protein Beclin-1 were down-regu-lated. Starvation or rapamycin stimulated A7R5 auto-phagy but overexpression of STIM1 or Orai1 significant-ly inhibited starvation or rapamycin induced autoph-agy. Conclusion Overexpression of store-operated calcium channel components STIM1 and/or Orai1 in rat arterial smooth muscle cells A7 R5 inhibit autoph-agy. This mechanism might contribute to the develop-ment of pulmonary arterial hypertension.
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Aim To investigate the expression of stro-mal interaction molecule 1 (STIM1) in rat pulmonary arterial hypertension ( PAH ) tissues and effects of STIM1 on arterial muscle cells proliferation. Methods PAH was induced by a single intraperitoneal injec-tion of MCT at a dose of 60 mg·kg - 1 . The mRNA or protein expressions of STIM1 in monocrotaline-induced pulmonary hypertensive rats were measured by real-time PCR or Western blot, respectively. The arterial smooth muscle cells A7R5 were transiently transfected with STIM1 plasmids to prepare STIM1 overexpressed cells. Cell proliferations were detected by using CCK-8 kits. The expressions of Akt/ mTOR pathway molecules of A7R5 were measured by Western blot. Results The right ventricular systolic blood pressure ( RVSP) and right ventricular mass index ( RVMI ) were markedly elevated in MCT-treated rats (P < 0. 01) in comparison to control rats. The mRNA and protein ex-pression levels of STIM1 in monocrotaline-induced pul-monary hypertensive rats were 2. 19 and 1. 66 folds of control rats, respectively. STIM1 were transiently over-expressed in cultured A7R5. Cells transfected with STIM1 grew more quickly than non-transfected control. Overexpression of STIM1 significantly increased the phosphorylation of Akt, mTOR, p70-S6K, and 4E-BP1, but did not change their protein expression lev-els. Conclusion STIM1 are over-expressed in rat PAH tissues. Overexpression of STIM1 can promote ar-terial smooth muscle cells proliferation by regulating Akt/ mTOR pathway.
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As one of the chronic diseases,asthma,plays a serious impact on human daily life.Asthma in children has showed an increasing trend in recent years,but the mechanisms of asthma are not yet clear.Studies have found that store-operated calcium entry(SOCE) plays an important role in the physiological activity of the body.The enhanced SOCE activity can promote cell growth,proliferation,and migration of a variety of cell types.SOCE important molecules STIM1 and ORAI1 may be involved in the asthmatic airway occurrence of hyperresponsiveness and airway remodeling,and closely to the asthmatic development.
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Objective To explore the role of stromal interaction molecule 1(STIMI)on prohteration and intra- cellular Ca~(2+)change in vascular smooth muscle ceils(VSMC).Methods Rat VSMC were isolated from SD rats and primary cultured.Ad-si/rSTIM1 and Ad-hSTIM1 were transfected into VSMC.The protein of STIM1 was measured by Western blot,the proliferation of VSMC was analyzed by ~3H-thymidine(~3H-TdR)incorporation and cell count,the intracellular Ca~(2+)change was assessed By Aquaeosmos system.Ruselts Fourty-eight hours after transfection,as compared with Ad-hSTIMI group,the Ad-si/rSTIMI VSMC had lower expression of STIM1 protein (P
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Objective To investigate the expression changes of stromal interaction molecule 1 (STIM1) in vascular smooth muscle cells in balloon injury of carotid artery in rat in order to explore the proliferation mechanism of vascular smooth muscle cells. Methods A rat model of vascular restenosis induced by injury to the carotid arteries due to balloon dilatation was reproduced in present study. A total of 18 SD rats were randomly divided into 3 groups (6 each): control group, 7-day group and 14-day group after balloon injury to the carotid artery. The expression of STIM1 mRNA in vascular smooth muscle cells was assayed with reverse transcription polymerase chain reaction (RT-PCR), and the STIM1 protein was assessed by immunohistochemistry. The histopathology of the arteries was examined after by HE staining. Results Intima area/media area ratio (IA/MA) was significantly increased in 7-day group after balloon injury than in control group (P