The formation of axonal spheroid is a common feature following spinal cord injury.To further understand the source of Ca^(2+)that mediates axonal spheroid formation,we used our previously characterized ex vivo mouse s...The formation of axonal spheroid is a common feature following spinal cord injury.To further understand the source of Ca^(2+)that mediates axonal spheroid formation,we used our previously characterized ex vivo mouse spinal cord model that allows precise perturbation of extracellular Ca^(2+).We performed twophoton excitation imaging of spinal cords isolated from Thy1YFP+transgenic mice and applied the lipophilic dye,Nile red,to record dynamic changes in dorsal column axons and their myelin sheaths respectively.We selectively released Ca^(2+)from internal stores using the Ca^(2+)ionophore ionomycin in the presence or absence of external Ca^(2+).We reported that ionomycin dose-dependently induces pathological changes in myelin and pronounced axonal spheroid formation in the presence of normal 2 m M Ca^(2+)artificial cerebrospinal fluid.In contrast,removal of external Ca^(2+)significantly decreased ionomycin-induced myelin and axonal spheroid formation at 2 hours but not at 1 hour after treatment.Using mice that express a neuron-specific Ca^(2+)indicator in spinal cord axons,we confirmed that ionomycin induced significant increases in intra-axonal Ca^(2+),but not in the absence of external Ca^(2+).Periaxonal swelling and the resultant disruption in the axo-myelinic interface often precedes and is negatively correlated with axonal spheroid formation.Pretreatment with YM58483(500 n M),a well-established blocker of store-operated Ca^(2+)entry,significantly decreased myelin injury and axonal spheroid formation.Collectively,these data reveal that ionomycin-induced depletion of internal Ca^(2+)stores and subsequent external Ca^(2+)entry through store-operated Ca^(2+)entry contributes to pathological changes in myelin and axonal spheroid formation,providing new targets to protect central myelinated fibers.展开更多
AIM: To investigate the effect of polydatin (PD), a resveratrol glucoside, on mast cell degranulation and antiallergic activity. METHODS: After the rats were orally sensitized with ovalbumin (OVA) for 48 d and underwe...AIM: To investigate the effect of polydatin (PD), a resveratrol glucoside, on mast cell degranulation and antiallergic activity. METHODS: After the rats were orally sensitized with ovalbumin (OVA) for 48 d and underwent PD treatment for 4 d, all the rats were stimulated by 100 mg/mL OVA for24 h and then sacrificed for the following experiments. The small intestines from all the groups were prepared for morphology examination by hematoxylin and eosin staining. We also used a smooth muscle organ bath to evaluate the motility of the small intestines. The OVA-specific immunoglobulin E (IgE) production and interleu-kin-4 (IL-4) levels in serum or supernatant of intestinal mucosa homogenates were analyzed by enzyme-linked immunosorbent assay (ELISA). Using toluidine blue stain, the activation and degranulation of isolated rat peritoneal mast cells (RPMCs) were analyzed. Release of histamine from RPMCs was measured by ELISA, and regulation of PD on intracellular Ca 2+ mobilization was investigated by probing intracellular Ca 2+ with fluo-4 fluo-rescent dye, with the signal recorded and analyzed. RESULTS: We found that intragastric treatment with PD significantly reduced loss of mucosal barrier integrity in the small intestine. However, OVA-sensitization caused significant hyperactivity in the small intestine of allergic rats, which was attenuated by PD administration by 42% (1.26 ± 0.13 g vs OVA 2.18 ± 0.21 g, P < 0.01). PD therapy also inhibited IgE production (3.95 ± 0.53 ng/mL vs OVA 4.53 ± 0.52 ng/mL, P < 0.05) by suppressing the secretion of Th2-type cytokine, IL-4, by 34% (38.58 ± 4.41 pg/mLvs OVA 58.15 ± 6.24 pg/mL, P < 0.01). The ratio of degranulated mast cells, as indicated by vehicles (at least five) around the cells, dramatically increased in the OVA group by 5.5 fold (63.50% ± 15.51% vs phosphate-buffered saline 11.15% ± 8.26%, P < 0.001) and fell by 65% after PD treatment (21.95% ± 4.37% vs OVA 63.50% ± 15.51%, P < 0.001). PD mediated attenuation of mast cell degranulation was further confirmed by decreased histamine levels in both serum (5.98 ± 0.17 vs OVA 6.67 ± 0.12, P < 0.05) and intestinal mucosa homogenates (5.83 ± 0.91 vs OVA 7.35 ± 0.97, P < 0.05). Furthermore, we demonstrated that administration with PD significantly decreased mast cell degranulation due to reduced Ca 2+ influx through store-operated calcium channels (SOCs) (2.35 ± 0.39vs OVA 3.51 ± 0.38,P < 0.01).CONCLUSION: Taken together, our data indicate that PD stabilizes mast cells by suppressing intracellular Ca 2+ mobilization, mainly through inhibiting Ca 2+ entry via SOCs, thus exerting a protective role against OVA-sensitized food allergy.展开更多
The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (...The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (Isoc) in isolated rat hepatocytes after hepatic ischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC 50 value of 64.63±10.56 μmol/L (n=8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.展开更多
Neuroglial cells are homeostatic neural cells. Generally, they are electrically non-excitable and their activation is associated with the generation of complex intracellular Ca^2＋ signals that define the ＂Ca^2＋ exc...Neuroglial cells are homeostatic neural cells. Generally, they are electrically non-excitable and their activation is associated with the generation of complex intracellular Ca^2＋ signals that define the ＂Ca^2＋ excitability＂ of glia. In mammalian glial cells the major source of Ca^2＋ for this excitability is the lumen of the endoplasmic reticulum （ER）, which is ultimately （re）filled from the extracellular space. This occurs via store-operated Ca^2＋ entry （SOCE） which is supported by a specific signaling system connecting the ER with plasmalemmal Ca^2＋ entry. Here, emptying of the ER Ca^2＋ store is necessary and sufficient for the activation of SOCE, and without Ca^2＋ influx via SOCE the ER store cannot be refilled. The molecular arrangements underlying SOCE are relatively complex and include plasmalemmal channels, ER Ca^2＋ sensors, such as stromal interaction molecule, and possibly ER Ca^2＋ pumps （of the SERCA type）. There are at least two sets of plasmalemmal channels mediating SOCE, the Ca2＊-release activated channels, Orai, and transient receptor potential （TRP） channels. The molecular identity of neuroglial SOCE has not been yet identified unequivocally. However, it seems that Orai is predominantly expressed in microglia, whereas astrocytes and oligodendrocytes rely more on TRP channels to produce SOCE. In physiological conditions the SOCE pathway is instrumental for the sustained phase of the Ca^2＋ signal observed following stimulation of metabotropic receptors on glial cells.展开更多
Hepatitis B virus X（HBx） protein plays a pivotal role in the development of hepatitis B virus（HBV）-associated hepatocellular carcinoma.Although regulation of cytosolic calcium is essential for HBV replication and ...Hepatitis B virus X（HBx） protein plays a pivotal role in the development of hepatitis B virus（HBV）-associated hepatocellular carcinoma.Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein,the mechanism of HBx protein regulating intracellular calcium level remains poorly understood.The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry（SOCE） components,Orai1 and stromal interaction molecule 1,and then identified the targets of HBx protein,with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis.By employing co-immunoprecipitation and GST-pull-down assay,we found that Orai1 protein interacted with HBx protein,and the C-terminus of Orai1 was implicated in the interaction.Confocal microscopy also revealed that HBx protein could co-localize with full-length Orai1 protein in HEK293 cells.Moreover,live cell calcium imaging exhibited that HBx protein elevated intracellular calcium,possibly by binding to SOCE components.Our results suggest that HBx protein binds to STIM1-Orai1 complexes to positively regulate the activity of plasma membrane store-operated calcium channels.展开更多
OBJECTIVE To explore the effect of total flavonoids of Rhododendra simsii(TFR)on improving cerebral ischemia/reperfusion injury(CIRI)and its relationship with STIM/Orai-regulated operational Ca^(2+)influx(SOCE)pathway...OBJECTIVE To explore the effect of total flavonoids of Rhododendra simsii(TFR)on improving cerebral ischemia/reperfusion injury(CIRI)and its relationship with STIM/Orai-regulated operational Ca^(2+)influx(SOCE)pathway.METHODS Oxygen-glucose deprivation/reoxygenation(OGD/R)PC12 cells were used to simulate CIRI in vitro,and the intracellular Ca^(2+)concentration and apoptosis rate of PC12 cells were detected by laser confocal microscope and flow cytometry,respectively.The regulation of STIM/Orai on SOCE was analyzed by STIM/Orai gene silencing and STIM/O rai gene overexpression.The CIRI model was established by MCAO in SD rats.The activities of inflammatory cytokines IL^(-1),IL-6 and TNF-αin serum were detected by ELISA.The pathological changes of ischemic brain tissue and the infarction of rat brain tissue were detected by HE staining and TTC staining.The protein and mRNA expression levels of STIM1,STIM2,Orai1,caspase-3 and PKB in brain tissue were detected by Western blotting and RT-qPCR,respectively.RESULTS The results of in vitro experiment showed that the fluorescence intensity of Ca^(2+)and apoptosis rate in PC12 cells treated with TFR were significantly lower than those in OGD/R group,and this trend was enhanced by SOCE antagonist 2-APB.STIM1/STIM2/Orai1 gene silencing significantly reduced apoptosis and Ca^(2+)overload in OGD/R model,while TFR combined with overexpression of STIM1/STIM2/Orai1 aggravated apoptosis and Ca2+overload.In the in vivo experiment,TFR significantly reduced the brain histopathological damage,infarction of brain tissue,the contents of IL^(-1),IL-6 and TNF-αin the serum in MCAO rats and down-regulated the expression of STIM1,STIM2,Orai1 and caspase-3 protein and mRNA in the brain tissue,and up-regulated the expression of PKB.The above effects were enhanced by the addition of 2-APB.CONCLUSION The above results indicate that TFR may reduce the contents of inflammatory factors and apoptosis,decrease Ca2+overload and ameliorate brain injury by inhibiting SOCE pathway mediated by STIM and Orai,suggesting that it has a protective effect against subacute CIRI.展开更多
The intracellular calcium ions(Ca^(2+)) act as second messenger to regulate gene transcription,cell proliferation, migration and death. Accumulating evidences have demonstrated that intracellular Ca^(2+)homeostasis is...The intracellular calcium ions(Ca^(2+)) act as second messenger to regulate gene transcription,cell proliferation, migration and death. Accumulating evidences have demonstrated that intracellular Ca^(2+)homeostasis is altered in cancer cells and the alteration is involved in tumor initiation, angiogenesis,progression and metastasis. Targeting derailed Ca^(2+)signaling for cancer therapy has become an emerging research area. This review summarizes some important Ca^(2+)channels, transporters and Ca^(2+)-ATPases,which have been reported to be altered in human cancer patients. It discusses the current research effort toward evaluation of the blockers, inhibitors or regulators for Ca^(2+)channels/transporters or Ca^(2+)-ATPase pumps as anti-cancer drugs. This review is also aimed to stimulate interest in, and support for researchinto the understanding of cellular mechanisms underlying the regulation of Ca^(2+)signaling in different cancer cells, and to search for novel therapies to cure these malignancies by targeting Ca^(2+)channels or transporters.展开更多
文摘The formation of axonal spheroid is a common feature following spinal cord injury.To further understand the source of Ca^(2+)that mediates axonal spheroid formation,we used our previously characterized ex vivo mouse spinal cord model that allows precise perturbation of extracellular Ca^(2+).We performed twophoton excitation imaging of spinal cords isolated from Thy1YFP+transgenic mice and applied the lipophilic dye,Nile red,to record dynamic changes in dorsal column axons and their myelin sheaths respectively.We selectively released Ca^(2+)from internal stores using the Ca^(2+)ionophore ionomycin in the presence or absence of external Ca^(2+).We reported that ionomycin dose-dependently induces pathological changes in myelin and pronounced axonal spheroid formation in the presence of normal 2 m M Ca^(2+)artificial cerebrospinal fluid.In contrast,removal of external Ca^(2+)significantly decreased ionomycin-induced myelin and axonal spheroid formation at 2 hours but not at 1 hour after treatment.Using mice that express a neuron-specific Ca^(2+)indicator in spinal cord axons,we confirmed that ionomycin induced significant increases in intra-axonal Ca^(2+),but not in the absence of external Ca^(2+).Periaxonal swelling and the resultant disruption in the axo-myelinic interface often precedes and is negatively correlated with axonal spheroid formation.Pretreatment with YM58483(500 n M),a well-established blocker of store-operated Ca^(2+)entry,significantly decreased myelin injury and axonal spheroid formation.Collectively,these data reveal that ionomycin-induced depletion of internal Ca^(2+)stores and subsequent external Ca^(2+)entry through store-operated Ca^(2+)entry contributes to pathological changes in myelin and axonal spheroid formation,providing new targets to protect central myelinated fibers.
基金Supported by The Natural Science Foundation of China,No.81271950,to Ji QMProjects of International/HMT(Hong Kong,Macao,and Taiwan)Cooperation and Innovation Platform in Science and Technology of Guangdong Higher Education Institutions,No.2012gjhz0009,to Liu ZG+2 种基金Key Laboratory Construction Program of Shenzhen,No.SW201110010,to Liu ZGBasic Research Program of Shenzhen University,No.201101,to Liu ZGBasic Research Foundation of Shenzhen,No.JC201005250059A,JCYJ20120613115535998
文摘AIM: To investigate the effect of polydatin (PD), a resveratrol glucoside, on mast cell degranulation and antiallergic activity. METHODS: After the rats were orally sensitized with ovalbumin (OVA) for 48 d and underwent PD treatment for 4 d, all the rats were stimulated by 100 mg/mL OVA for24 h and then sacrificed for the following experiments. The small intestines from all the groups were prepared for morphology examination by hematoxylin and eosin staining. We also used a smooth muscle organ bath to evaluate the motility of the small intestines. The OVA-specific immunoglobulin E (IgE) production and interleu-kin-4 (IL-4) levels in serum or supernatant of intestinal mucosa homogenates were analyzed by enzyme-linked immunosorbent assay (ELISA). Using toluidine blue stain, the activation and degranulation of isolated rat peritoneal mast cells (RPMCs) were analyzed. Release of histamine from RPMCs was measured by ELISA, and regulation of PD on intracellular Ca 2+ mobilization was investigated by probing intracellular Ca 2+ with fluo-4 fluo-rescent dye, with the signal recorded and analyzed. RESULTS: We found that intragastric treatment with PD significantly reduced loss of mucosal barrier integrity in the small intestine. However, OVA-sensitization caused significant hyperactivity in the small intestine of allergic rats, which was attenuated by PD administration by 42% (1.26 ± 0.13 g vs OVA 2.18 ± 0.21 g, P < 0.01). PD therapy also inhibited IgE production (3.95 ± 0.53 ng/mL vs OVA 4.53 ± 0.52 ng/mL, P < 0.05) by suppressing the secretion of Th2-type cytokine, IL-4, by 34% (38.58 ± 4.41 pg/mLvs OVA 58.15 ± 6.24 pg/mL, P < 0.01). The ratio of degranulated mast cells, as indicated by vehicles (at least five) around the cells, dramatically increased in the OVA group by 5.5 fold (63.50% ± 15.51% vs phosphate-buffered saline 11.15% ± 8.26%, P < 0.001) and fell by 65% after PD treatment (21.95% ± 4.37% vs OVA 63.50% ± 15.51%, P < 0.001). PD mediated attenuation of mast cell degranulation was further confirmed by decreased histamine levels in both serum (5.98 ± 0.17 vs OVA 6.67 ± 0.12, P < 0.05) and intestinal mucosa homogenates (5.83 ± 0.91 vs OVA 7.35 ± 0.97, P < 0.05). Furthermore, we demonstrated that administration with PD significantly decreased mast cell degranulation due to reduced Ca 2+ influx through store-operated calcium channels (SOCs) (2.35 ± 0.39vs OVA 3.51 ± 0.38,P < 0.01).CONCLUSION: Taken together, our data indicate that PD stabilizes mast cells by suppressing intracellular Ca 2+ mobilization, mainly through inhibiting Ca 2+ entry via SOCs, thus exerting a protective role against OVA-sensitized food allergy.
基金This project was supported by the National Natural Sci ence Foundation of China (No. 30270532), the Trans Cen tury Excellent Talent Development Plan Fund of Ministry ofEducation of China (Official Letter No. 2002 48) and Shu guang Program Project of Shanghai Educational Committee(No. 02SG20).
文摘The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (Isoc) in isolated rat hepatocytes after hepatic ischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC 50 value of 64.63±10.56 μmol/L (n=8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.
基金supported by an Alzheimer’s Research Trust(UK)Programme Grant(ART/PG2004A/1)to A.V.by a National Science Foundation grant(CBET 0943343)to V.P
文摘Neuroglial cells are homeostatic neural cells. Generally, they are electrically non-excitable and their activation is associated with the generation of complex intracellular Ca^2＋ signals that define the ＂Ca^2＋ excitability＂ of glia. In mammalian glial cells the major source of Ca^2＋ for this excitability is the lumen of the endoplasmic reticulum （ER）, which is ultimately （re）filled from the extracellular space. This occurs via store-operated Ca^2＋ entry （SOCE） which is supported by a specific signaling system connecting the ER with plasmalemmal Ca^2＋ entry. Here, emptying of the ER Ca^2＋ store is necessary and sufficient for the activation of SOCE, and without Ca^2＋ influx via SOCE the ER store cannot be refilled. The molecular arrangements underlying SOCE are relatively complex and include plasmalemmal channels, ER Ca^2＋ sensors, such as stromal interaction molecule, and possibly ER Ca^2＋ pumps （of the SERCA type）. There are at least two sets of plasmalemmal channels mediating SOCE, the Ca2＊-release activated channels, Orai, and transient receptor potential （TRP） channels. The molecular identity of neuroglial SOCE has not been yet identified unequivocally. However, it seems that Orai is predominantly expressed in microglia, whereas astrocytes and oligodendrocytes rely more on TRP channels to produce SOCE. In physiological conditions the SOCE pathway is instrumental for the sustained phase of the Ca^2＋ signal observed following stimulation of metabotropic receptors on glial cells.
基金supported by grants from the National Natural Science Foundation of China(No.81001063)the Fundamental Research Funds for the Central Universities(No.2015QN150)
文摘Hepatitis B virus X（HBx） protein plays a pivotal role in the development of hepatitis B virus（HBV）-associated hepatocellular carcinoma.Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein,the mechanism of HBx protein regulating intracellular calcium level remains poorly understood.The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry（SOCE） components,Orai1 and stromal interaction molecule 1,and then identified the targets of HBx protein,with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis.By employing co-immunoprecipitation and GST-pull-down assay,we found that Orai1 protein interacted with HBx protein,and the C-terminus of Orai1 was implicated in the interaction.Confocal microscopy also revealed that HBx protein could co-localize with full-length Orai1 protein in HEK293 cells.Moreover,live cell calcium imaging exhibited that HBx protein elevated intracellular calcium,possibly by binding to SOCE components.Our results suggest that HBx protein binds to STIM1-Orai1 complexes to positively regulate the activity of plasma membrane store-operated calcium channels.
基金National Natural Science Foundation of China(81173596)and Major Project of Natural Science Foundation of the Department of Education of Anhui Province(KJ2019ZD32)。
文摘OBJECTIVE To explore the effect of total flavonoids of Rhododendra simsii(TFR)on improving cerebral ischemia/reperfusion injury(CIRI)and its relationship with STIM/Orai-regulated operational Ca^(2+)influx(SOCE)pathway.METHODS Oxygen-glucose deprivation/reoxygenation(OGD/R)PC12 cells were used to simulate CIRI in vitro,and the intracellular Ca^(2+)concentration and apoptosis rate of PC12 cells were detected by laser confocal microscope and flow cytometry,respectively.The regulation of STIM/Orai on SOCE was analyzed by STIM/Orai gene silencing and STIM/O rai gene overexpression.The CIRI model was established by MCAO in SD rats.The activities of inflammatory cytokines IL^(-1),IL-6 and TNF-αin serum were detected by ELISA.The pathological changes of ischemic brain tissue and the infarction of rat brain tissue were detected by HE staining and TTC staining.The protein and mRNA expression levels of STIM1,STIM2,Orai1,caspase-3 and PKB in brain tissue were detected by Western blotting and RT-qPCR,respectively.RESULTS The results of in vitro experiment showed that the fluorescence intensity of Ca^(2+)and apoptosis rate in PC12 cells treated with TFR were significantly lower than those in OGD/R group,and this trend was enhanced by SOCE antagonist 2-APB.STIM1/STIM2/Orai1 gene silencing significantly reduced apoptosis and Ca^(2+)overload in OGD/R model,while TFR combined with overexpression of STIM1/STIM2/Orai1 aggravated apoptosis and Ca2+overload.In the in vivo experiment,TFR significantly reduced the brain histopathological damage,infarction of brain tissue,the contents of IL^(-1),IL-6 and TNF-αin the serum in MCAO rats and down-regulated the expression of STIM1,STIM2,Orai1 and caspase-3 protein and mRNA in the brain tissue,and up-regulated the expression of PKB.The above effects were enhanced by the addition of 2-APB.CONCLUSION The above results indicate that TFR may reduce the contents of inflammatory factors and apoptosis,decrease Ca2+overload and ameliorate brain injury by inhibiting SOCE pathway mediated by STIM and Orai,suggesting that it has a protective effect against subacute CIRI.
基金supported by NIH R01-CA185055(to Zui Pan)Chaochu Cui received postgraduate student training of internationalization level promotion program from Sun Yat-sen University(02300-52114000)
文摘The intracellular calcium ions(Ca^(2+)) act as second messenger to regulate gene transcription,cell proliferation, migration and death. Accumulating evidences have demonstrated that intracellular Ca^(2+)homeostasis is altered in cancer cells and the alteration is involved in tumor initiation, angiogenesis,progression and metastasis. Targeting derailed Ca^(2+)signaling for cancer therapy has become an emerging research area. This review summarizes some important Ca^(2+)channels, transporters and Ca^(2+)-ATPases,which have been reported to be altered in human cancer patients. It discusses the current research effort toward evaluation of the blockers, inhibitors or regulators for Ca^(2+)channels/transporters or Ca^(2+)-ATPase pumps as anti-cancer drugs. This review is also aimed to stimulate interest in, and support for researchinto the understanding of cellular mechanisms underlying the regulation of Ca^(2+)signaling in different cancer cells, and to search for novel therapies to cure these malignancies by targeting Ca^(2+)channels or transporters.
