M. Debant, P. Hémon, C. Brigaudeau, Yves Renaudineau, O. Mignen
Ca(2+) signaling is a key regulator of B lymphocyte cell fate and defects in this signaling pathway have been reported in numerous diseases such as Chronic lymphocytic leukemia (CLL). CLL is a B cell clonal disorder characterized by the accumulation of mature monoclonal CD5(+) B cells. Although CLL could be considered to be a proliferative disease, most circulating CLL B cells are arrested in the G0 phase of the cell cycle and present both defects in calcium (Ca(2+)) homeostasis and signaling. The Ca(2+) response to antigen ligation is heterogeneous and related, in part, to defects arising from the incapacity to respond to B cell receptor (BCR) engagement (anergy), to the expression of T cell kinases (e.g. Zap70), and to the presence of negative feedback regulation by phosphatases (e.g. SHP-1). Anergic CD5(+) CLL B cells are characterized by an elevated basal Ca(2+) level, IgM/CD79 downregulation, a constitutive activation of BCR pathway kinases, and an activation of the nuclear factor of activated T cells (NF-AT). Based on the Ca(2+) response, patients are classified into three groups: unresponders, responders with apoptosis, and responders with entry in the cell cycle. Moreover, internal and direct interaction between leukemic BCR-HCDR3 epitopes at the plasma membrane and interaction between Bcl-2 and the IP3-receptor at the endoplasmic reticulum are also suspected to interfere with the intracellular Ca(2+) homeostasis in CLL-B cells. As a whole, the Ca(2+) pathway is emerging to play a key role in malignant CLL-B survival, disease progression, and last but not least, in the therapeutic response.
{"title":"Calcium signaling and cell fate: how can Ca2+ signals contribute to wrong decisions for Chronic Lymphocytic Leukemic B lymphocyte outcome?","authors":"M. Debant, P. Hémon, C. Brigaudeau, Yves Renaudineau, O. Mignen","doi":"10.1387/ijdb.150204om","DOIUrl":"https://doi.org/10.1387/ijdb.150204om","url":null,"abstract":"Ca(2+) signaling is a key regulator of B lymphocyte cell fate and defects in this signaling pathway have been reported in numerous diseases such as Chronic lymphocytic leukemia (CLL). CLL is a B cell clonal disorder characterized by the accumulation of mature monoclonal CD5(+) B cells. Although CLL could be considered to be a proliferative disease, most circulating CLL B cells are arrested in the G0 phase of the cell cycle and present both defects in calcium (Ca(2+)) homeostasis and signaling. The Ca(2+) response to antigen ligation is heterogeneous and related, in part, to defects arising from the incapacity to respond to B cell receptor (BCR) engagement (anergy), to the expression of T cell kinases (e.g. Zap70), and to the presence of negative feedback regulation by phosphatases (e.g. SHP-1). Anergic CD5(+) CLL B cells are characterized by an elevated basal Ca(2+) level, IgM/CD79 downregulation, a constitutive activation of BCR pathway kinases, and an activation of the nuclear factor of activated T cells (NF-AT). Based on the Ca(2+) response, patients are classified into three groups: unresponders, responders with apoptosis, and responders with entry in the cell cycle. Moreover, internal and direct interaction between leukemic BCR-HCDR3 epitopes at the plasma membrane and interaction between Bcl-2 and the IP3-receptor at the endoplasmic reticulum are also suspected to interfere with the intracellular Ca(2+) homeostasis in CLL-B cells. As a whole, the Ca(2+) pathway is emerging to play a key role in malignant CLL-B survival, disease progression, and last but not least, in the therapeutic response.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"9 1","pages":"379-89"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80443761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In various oocytes and eggs of animals, transient elevations in cytoplasmic calcium ion concentrations are known to regulate key processes during fertilization and the completion of meiosis. However, whether or not calcium transients also help to reinitiate meiotic progression at the onset of oocyte maturation remains controversial. This article summarizes reports of calcium signals playing essential roles during maturation onset (=germinal vesicle breakdown, GVBD) in several kinds of marine invertebrate oocytes. Conversely, other data from the literature, as well as previously unpublished findings for jellyfish oocytes, fail to support the view that calcium signals are required for GVBD. In addition to assessing the effects of calcium transients on GVBD in marine invertebrate oocytes, the ability of maturing oocytes to enhance their calcium-releasing capabilities after GVBD is also reviewed. Furthermore, possible explanations are proposed for the contradictory results that have been obtained regarding calcium signals during oocyte maturation in marine invertebrates.
{"title":"Calcium signals and oocyte maturation in marine invertebrates.","authors":"R. Deguchi, N. Takeda, S. A. Stricker","doi":"10.1387/ijdb.150239ss","DOIUrl":"https://doi.org/10.1387/ijdb.150239ss","url":null,"abstract":"In various oocytes and eggs of animals, transient elevations in cytoplasmic calcium ion concentrations are known to regulate key processes during fertilization and the completion of meiosis. However, whether or not calcium transients also help to reinitiate meiotic progression at the onset of oocyte maturation remains controversial. This article summarizes reports of calcium signals playing essential roles during maturation onset (=germinal vesicle breakdown, GVBD) in several kinds of marine invertebrate oocytes. Conversely, other data from the literature, as well as previously unpublished findings for jellyfish oocytes, fail to support the view that calcium signals are required for GVBD. In addition to assessing the effects of calcium transients on GVBD in marine invertebrate oocytes, the ability of maturing oocytes to enhance their calcium-releasing capabilities after GVBD is also reviewed. Furthermore, possible explanations are proposed for the contradictory results that have been obtained regarding calcium signals during oocyte maturation in marine invertebrates.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"52 1","pages":"271-80"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85330134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ca(2+) signals regulate a wide range of physiological processes. Intracellular Ca(2+) stores can be mobilized in response to extracellular stimuli via a range of signal transduction mechanisms, often involving recruitment of diffusible second messenger molecules. The Ca(2+) mobilizing messengers InsP 3 and cADPR release Ca(2+) from the endoplasmic reticulum via InsP 3 and ryanodine receptors, respectively, while a third messenger, NAADP, releases Ca(2+) from acidic endosomes and lysosomes. Bidirectional communication between the ER and acidic organelles has functional relevance for endolysosomal function as well as for the generation of Ca(2+) signals. The two-pore channels (TPCs) are currently strong candidates for being key components of NAADP-regulated Ca(2+) channels. Ca(2+) signals have been shown to play important roles in embryonic development and cell differentiation; however, much remains to be established about the exact signalling mechanisms involved. Investigation of the role of NAADP and TPCs in development and differentiation is still at an early stage, but recent studies have suggested that they play important roles at key developmental stages in vivo and are important mediators of differentiation of neurons, skeletal muscle cells and osteoclasts in vitro. NAADP signals and TPCs have also been implicated in autophagy, an important process in differentiation. Moreover, potential links between TPC2 and cancer have been recently identified. Further studies will be required to identify the precise mechanisms of action of TPCs and their link with NAADP signalling, and to relate these to their roles in differentiation and other key developmental processes in the cell and organism.
{"title":"Calcium signals regulated by NAADP and two-pore channels--their role in development, differentiation and cancer.","authors":"J. Parrington, P. Lear, A. Hachem","doi":"10.1387/ijdb.150211jp","DOIUrl":"https://doi.org/10.1387/ijdb.150211jp","url":null,"abstract":"Ca(2+) signals regulate a wide range of physiological processes. Intracellular Ca(2+) stores can be mobilized in response to extracellular stimuli via a range of signal transduction mechanisms, often involving recruitment of diffusible second messenger molecules. The Ca(2+) mobilizing messengers InsP 3 and cADPR release Ca(2+) from the endoplasmic reticulum via InsP 3 and ryanodine receptors, respectively, while a third messenger, NAADP, releases Ca(2+) from acidic endosomes and lysosomes. Bidirectional communication between the ER and acidic organelles has functional relevance for endolysosomal function as well as for the generation of Ca(2+) signals. The two-pore channels (TPCs) are currently strong candidates for being key components of NAADP-regulated Ca(2+) channels. Ca(2+) signals have been shown to play important roles in embryonic development and cell differentiation; however, much remains to be established about the exact signalling mechanisms involved. Investigation of the role of NAADP and TPCs in development and differentiation is still at an early stage, but recent studies have suggested that they play important roles at key developmental stages in vivo and are important mediators of differentiation of neurons, skeletal muscle cells and osteoclasts in vitro. NAADP signals and TPCs have also been implicated in autophagy, an important process in differentiation. Moreover, potential links between TPC2 and cancer have been recently identified. Further studies will be required to identify the precise mechanisms of action of TPCs and their link with NAADP signalling, and to relate these to their roles in differentiation and other key developmental processes in the cell and organism.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"73 1","pages":"341-55"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78796953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The characteristics of a cellular calcium signal (calcium signature) are determined, at least partly, by the expression of a subset of genes encoding proteins involved in calcium entry, calcium uptake and calcium modulation. Our aim in the present work was to characterize the set of genes involved in calcium signal generation that are differentially expressed in normal brain tissues versus brain tumor and/or glioma stem cells. Public datasets were analyzed according to a four step methodology consisting of: 1. detecting the outliers by using principal component analysis of the whole transcriptome; 2. building a calcium toolbox composed of 260 genes involved in the generation and modulation of the calcium signal; 3. analyzing the calcium toolbox transcriptome of different human brain areas and 4. detecting genes from the calcium toolbox preferentially expressed in tumor tissues or tumor cells compared to normal brain tissues. Our approach was validated on normal brain tissue. Tumor sample analysis allowed us to disclose a set of eighteen genes characteristic of glioblastoma tissues or glioma stem cells. Interpreting the set of genes highlighted in the study led us to propose that i) the mechanism of store operated calcium entry is strongly perturbed in cancer cells and tissues, ii) the process of calcium reuptake into mitochondria is more important in cancer cells and tissues than in their normal counterparts and iii) these two mechanisms may be coupled in at least one subgroup of the glioblastoma stem cells.
{"title":"Glioblastoma and calcium signaling--analysis of calcium toolbox expression.","authors":"N. Robil, F. Petel, M. Kilhoffer, J. Haiech","doi":"10.1387/ijdb.150200jh","DOIUrl":"https://doi.org/10.1387/ijdb.150200jh","url":null,"abstract":"The characteristics of a cellular calcium signal (calcium signature) are determined, at least partly, by the expression of a subset of genes encoding proteins involved in calcium entry, calcium uptake and calcium modulation. Our aim in the present work was to characterize the set of genes involved in calcium signal generation that are differentially expressed in normal brain tissues versus brain tumor and/or glioma stem cells. Public datasets were analyzed according to a four step methodology consisting of: 1. detecting the outliers by using principal component analysis of the whole transcriptome; 2. building a calcium toolbox composed of 260 genes involved in the generation and modulation of the calcium signal; 3. analyzing the calcium toolbox transcriptome of different human brain areas and 4. detecting genes from the calcium toolbox preferentially expressed in tumor tissues or tumor cells compared to normal brain tissues. Our approach was validated on normal brain tissue. Tumor sample analysis allowed us to disclose a set of eighteen genes characteristic of glioblastoma tissues or glioma stem cells. Interpreting the set of genes highlighted in the study led us to propose that i) the mechanism of store operated calcium entry is strongly perturbed in cancer cells and tissues, ii) the process of calcium reuptake into mitochondria is more important in cancer cells and tissues than in their normal counterparts and iii) these two mechanisms may be coupled in at least one subgroup of the glioblastoma stem cells.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"71 1","pages":"407-15"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86602428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ionic messengers signal several critical events in carcinogenesis, including metastasis, the leading cause of patient mortality. The aberrant metabolic, proliferative and anti-apoptotic nature of neoplastic cells can be traced to the abnormal expression of their ion transporters and related signalling networks. In this manuscript, we discuss Na(+)/H(+)flux, as mediated by the sodium-hydrogen exchanger isoform 1 (NHE1), a major ion transporter involved in tumourigenesis. Allosteric activation of NHE1 by external stimuli is controlled by phosphorylation of key amino acids on its cytosolic C-terminal tail, which also acts as a signal scaffold for its regulation by intracellular protein and lipid binding partners. In breast cancer cells, pH homeostasis and proton dynamics are disrupted early in transformation. This constitutively activates NHE1, causing a reversal of the plasma membrane pH gradient, resulting in a more alkaline intracellular pH and a more acidic extracellular pH. NHE1-mediated cellular alkalinization potentiates cytoskeletal remodelling, mobilizing cells for directed migration. Concomitant redistribution of NHE1 to invadopodia, where increased proton extrusion promotes proteolytic digestion of the extracellular matrix, primes cells for invasion into the bloodstream. NHE1 hyperactivity therefore heralds an important stage in cancer cell development, critically facilitating the acquisition of the invasive phenotype necessary for metastasis to occur. The potential for targeting NHE1 in the development of novel chemotherapeutic applications is explored.
{"title":"Na (+)/H (+)exchange in the tumour microenvironment: does NHE1 drive breast cancer carcinogenesis?","authors":"S. R. Amith, Sunny Fong, S. Baksh, L. Fliegel","doi":"10.1387/ijdb.140336lf","DOIUrl":"https://doi.org/10.1387/ijdb.140336lf","url":null,"abstract":"Ionic messengers signal several critical events in carcinogenesis, including metastasis, the leading cause of patient mortality. The aberrant metabolic, proliferative and anti-apoptotic nature of neoplastic cells can be traced to the abnormal expression of their ion transporters and related signalling networks. In this manuscript, we discuss Na(+)/H(+)flux, as mediated by the sodium-hydrogen exchanger isoform 1 (NHE1), a major ion transporter involved in tumourigenesis. Allosteric activation of NHE1 by external stimuli is controlled by phosphorylation of key amino acids on its cytosolic C-terminal tail, which also acts as a signal scaffold for its regulation by intracellular protein and lipid binding partners. In breast cancer cells, pH homeostasis and proton dynamics are disrupted early in transformation. This constitutively activates NHE1, causing a reversal of the plasma membrane pH gradient, resulting in a more alkaline intracellular pH and a more acidic extracellular pH. NHE1-mediated cellular alkalinization potentiates cytoskeletal remodelling, mobilizing cells for directed migration. Concomitant redistribution of NHE1 to invadopodia, where increased proton extrusion promotes proteolytic digestion of the extracellular matrix, primes cells for invasion into the bloodstream. NHE1 hyperactivity therefore heralds an important stage in cancer cell development, critically facilitating the acquisition of the invasive phenotype necessary for metastasis to occur. The potential for targeting NHE1 in the development of novel chemotherapeutic applications is explored.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"100 1","pages":"367-77"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81415099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Bernardini, A. Fiorio Pla, N. Prevarskaya, D. Gkika
Despite the intensive research of the last three decades into Transient Receptor Potential (TRP) cation channels, no precise and complete profiling of these channels is yet available regarding their involvement in physiopathology and carcinogenesis in particular. TRP channel activity is crucial for all the essential hallmarks of carcinogenesis such as proliferation, apoptosis, migration and angiogenesis, which is the reason why these channels have been proposed not only as clinical markers, but also as promising targets for anti-cancer therapy. However, in the majority of studies, each channel has been considered as a separate molecular entity and studied independently from the other TRPs, while a complete "transportome" of the specific stages of carcinogenesis is required for the effective use of these targets. This review focuses on the partial TRP expression profiles found in the literature and the means by which a full TRP signature could be achieved.
{"title":"Human transient receptor potential (TRP) channel expression profiling in carcinogenesis.","authors":"M. Bernardini, A. Fiorio Pla, N. Prevarskaya, D. Gkika","doi":"10.1387/ijdb.150232dg","DOIUrl":"https://doi.org/10.1387/ijdb.150232dg","url":null,"abstract":"Despite the intensive research of the last three decades into Transient Receptor Potential (TRP) cation channels, no precise and complete profiling of these channels is yet available regarding their involvement in physiopathology and carcinogenesis in particular. TRP channel activity is crucial for all the essential hallmarks of carcinogenesis such as proliferation, apoptosis, migration and angiogenesis, which is the reason why these channels have been proposed not only as clinical markers, but also as promising targets for anti-cancer therapy. However, in the majority of studies, each channel has been considered as a separate molecular entity and studied independently from the other TRPs, while a complete \"transportome\" of the specific stages of carcinogenesis is required for the effective use of these targets. This review focuses on the partial TRP expression profiles found in the literature and the means by which a full TRP signature could be achieved.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"53 1","pages":"399-406"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75091443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gametes are electrogenic cells that modify their electrical properties in response to different stimuli. This behavior is due to the occurrence of ion currents flowing through ion channels located on the plasma membranes. The modulation of ion channels has been described during the processes of gamete maturation, activation and fertilization in most of the animal models studied. In particular, predominant ions involved in physiological events in oocyte and sperm have been recognized to be sodium, potassium and calcium. In this review, we give an overview on the occurrence, modulation and function of ion fluxes, from gametogenesis to early fertilization events, from marine animals to human. The implications for a dynamic role of ion currents in gamete physiology and their possible clinical and technological applications are discussed.
{"title":"Ion currents involved in gamete physiology.","authors":"A. Gallo, E. Tosti","doi":"10.1387/ijdb.150202et","DOIUrl":"https://doi.org/10.1387/ijdb.150202et","url":null,"abstract":"Gametes are electrogenic cells that modify their electrical properties in response to different stimuli. This behavior is due to the occurrence of ion currents flowing through ion channels located on the plasma membranes. The modulation of ion channels has been described during the processes of gamete maturation, activation and fertilization in most of the animal models studied. In particular, predominant ions involved in physiological events in oocyte and sperm have been recognized to be sodium, potassium and calcium. In this review, we give an overview on the occurrence, modulation and function of ion fluxes, from gametogenesis to early fertilization events, from marine animals to human. The implications for a dynamic role of ion currents in gamete physiology and their possible clinical and technological applications are discussed.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"38 1","pages":"261-70"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83115099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The idea that electrical fields can influence the development of an organism is not new. Electrical fields in cells are mainly due to the presence of channels which are permeable and selective for different ions and transporters. Modulation of their activities can affect cell cycle properties, proliferation and differentiation.Electrical fields are important for embryonic patterning, regeneration and tumour development. Membrane potential is a permanent signal which allows communication between cells, tissues and organs and has to be considered to have the same importance as biochemical signals. The activity of ion channels and pumps which maintain the electrical fields can now be dissected and visualized with new tools involving fluorescent reporters.Despite the fact that our understanding, at the molecular level, of the role of bioelectric signaling pathways, ion currents, voltage and pH gradients in developmental biology and tumor progression is increasing, therapeutic applications of this knowledge still appears to be far away. For the moment, research priorities seem to be on establishing the links between biochemical events, genetic regulation, and network interactions.
{"title":"Ionic messengers in development and cancer.","authors":"M. Moreau, C. Leclerc","doi":"10.1387/ijdb.150215mm","DOIUrl":"https://doi.org/10.1387/ijdb.150215mm","url":null,"abstract":"The idea that electrical fields can influence the development of an organism is not new. Electrical fields in cells are mainly due to the presence of channels which are permeable and selective for different ions and transporters. Modulation of their activities can affect cell cycle properties, proliferation and differentiation.Electrical fields are important for embryonic patterning, regeneration and tumour development. Membrane potential is a permanent signal which allows communication between cells, tissues and organs and has to be considered to have the same importance as biochemical signals. The activity of ion channels and pumps which maintain the electrical fields can now be dissected and visualized with new tools involving fluorescent reporters.Despite the fact that our understanding, at the molecular level, of the role of bioelectric signaling pathways, ion currents, voltage and pH gradients in developmental biology and tumor progression is increasing, therapeutic applications of this knowledge still appears to be far away. For the moment, research priorities seem to be on establishing the links between biochemical events, genetic regulation, and network interactions.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"90 1","pages":"257-60"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73693613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jeffrey J. Kelu, Hayley Chan, S. Webb, Arthur H. Cheng, M. Ruas, J. Parrington, A. Galione, A. Miller
We have recently characterized essential inositol 1,4,5-trisphosphate receptor (IP 3R) and ryanodine receptor (RyR)-mediated Ca(2+) signals generated during the differentiation of slow muscle cells (SMCs) in intact zebrafish embryos. Here, we show that the lysosomal two-pore channel 2 (TPC2) also plays a crucial role in generating, and perhaps triggering, these essential Ca(2+) signals, and thus contributes to the regulation of skeletal muscle myogenesis. We used a transgenic line of zebrafish that expresses the bioluminescent Ca(2+) reporter, aequorin, specifically in skeletal muscle, in conjunction with morpholino (MO)-based and pharmacological inhibition of TPC2, in both intact embryos and isolated SMCs. MO-based knock-down of TPC2 resulted in a dramatic attenuation of the Ca(2+) signals, whereas the introduction of TPCN2-MO and TPCN2 mRNA together partially rescued the Ca(2+) signaling signature. Embryos treated with trans-ned-19 or bafilomycin A1, a specific NAADP receptor inhibitor and vacuolar-type H(+)ATPase inhibitor, respectively, also displayed a similar disruption of SMC Ca(2+) signaling. TPC2 and lysosomes were shown via immunohistochemistry and confocal laser scanning microscopy to be localized in perinuclear and striated cytoplasmic domains of SMCs, coincident with patterns of IP 3R and RyR expression. These data together imply that TPC2-mediated Ca(2+) release from lysosomes acts upstream from RyR- and IP 3R-mediated Ca(2+) release, suggesting that the former might act as a sensitive trigger to initiate the SR-mediated Ca(2+)-induced-Ca(2+)-release essential for SMC myogenesis and function.
{"title":"Two-Pore Channel 2 activity is required for slow muscle cell-generated Ca(2+) signaling during myogenesis in intact zebrafish.","authors":"Jeffrey J. Kelu, Hayley Chan, S. Webb, Arthur H. Cheng, M. Ruas, J. Parrington, A. Galione, A. Miller","doi":"10.1387/ijdb.150206am","DOIUrl":"https://doi.org/10.1387/ijdb.150206am","url":null,"abstract":"We have recently characterized essential inositol 1,4,5-trisphosphate receptor (IP 3R) and ryanodine receptor (RyR)-mediated Ca(2+) signals generated during the differentiation of slow muscle cells (SMCs) in intact zebrafish embryos. Here, we show that the lysosomal two-pore channel 2 (TPC2) also plays a crucial role in generating, and perhaps triggering, these essential Ca(2+) signals, and thus contributes to the regulation of skeletal muscle myogenesis. We used a transgenic line of zebrafish that expresses the bioluminescent Ca(2+) reporter, aequorin, specifically in skeletal muscle, in conjunction with morpholino (MO)-based and pharmacological inhibition of TPC2, in both intact embryos and isolated SMCs. MO-based knock-down of TPC2 resulted in a dramatic attenuation of the Ca(2+) signals, whereas the introduction of TPCN2-MO and TPCN2 mRNA together partially rescued the Ca(2+) signaling signature. Embryos treated with trans-ned-19 or bafilomycin A1, a specific NAADP receptor inhibitor and vacuolar-type H(+)ATPase inhibitor, respectively, also displayed a similar disruption of SMC Ca(2+) signaling. TPC2 and lysosomes were shown via immunohistochemistry and confocal laser scanning microscopy to be localized in perinuclear and striated cytoplasmic domains of SMCs, coincident with patterns of IP 3R and RyR expression. These data together imply that TPC2-mediated Ca(2+) release from lysosomes acts upstream from RyR- and IP 3R-mediated Ca(2+) release, suggesting that the former might act as a sensitive trigger to initiate the SR-mediated Ca(2+)-induced-Ca(2+)-release essential for SMC myogenesis and function.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"15 1","pages":"313-25"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82419039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Chan, Yiyun Chen, T. S. Hung, A. Miller, A. Shipley, S. Webb
During the first few cell division cycles in zebrafish, distinct Ca(2+) transients are localized to the early embryonic cleavage furrows, where they accompany (and are required for) furrow positioning, propagation, deepening and apposition. It has previously been shown that the endoplasmic reticulum (ER) acts as the primary store for generating these Ca(2+) transients via release through inositol 1,4,5-trisphosphate receptors (IP 3Rs). We hypothesised that maintaining the elevated levels of intracellular Ca(2+) required for deepening and apposition of the cleavage furrows in these large eggs might result in the depletion of the available ER Ca(2+) store, thus the role of store-operated Ca(2+) entry (SOCE) was examined. Newly fertilized, dechorionated embryos were incubated with various SOCE inhibitors, starting just prior to the onset of the first cell division cycle. The effect of these inhibitors on mitosis, furrow positioning, propagation, deepening and apposition, and the generation of the cytokinetic Ca(2+) transients was determined. Treatment with 2-APB or SKF 96365 had no major effect on mitosis, furrow positioning or propagation, but inhibited furrow deepening resulting in regression of the cleavage furrow. Both of these inhibitors also blocked the furrowing Ca(2+) transient, with SKF 96365 having a more profound inhibitory effect than 2-APB. In zebrafish, SOCE does not appear to be required for mitosis or the early stages of cytokinesis during the early embryonic cell division cycles, but it does appear to be essential for maintaining the elevated levels of [Ca(2+)]i for the extended periods that are required during furrow deepening and daughter cell apposition.
{"title":"Inhibition of SOCE disrupts cytokinesis in zebrafish embryos via inhibition of cleavage furrow deepening.","authors":"C. Chan, Yiyun Chen, T. S. Hung, A. Miller, A. Shipley, S. Webb","doi":"10.1387/ijdb.150209sw","DOIUrl":"https://doi.org/10.1387/ijdb.150209sw","url":null,"abstract":"During the first few cell division cycles in zebrafish, distinct Ca(2+) transients are localized to the early embryonic cleavage furrows, where they accompany (and are required for) furrow positioning, propagation, deepening and apposition. It has previously been shown that the endoplasmic reticulum (ER) acts as the primary store for generating these Ca(2+) transients via release through inositol 1,4,5-trisphosphate receptors (IP 3Rs). We hypothesised that maintaining the elevated levels of intracellular Ca(2+) required for deepening and apposition of the cleavage furrows in these large eggs might result in the depletion of the available ER Ca(2+) store, thus the role of store-operated Ca(2+) entry (SOCE) was examined. Newly fertilized, dechorionated embryos were incubated with various SOCE inhibitors, starting just prior to the onset of the first cell division cycle. The effect of these inhibitors on mitosis, furrow positioning, propagation, deepening and apposition, and the generation of the cytokinetic Ca(2+) transients was determined. Treatment with 2-APB or SKF 96365 had no major effect on mitosis, furrow positioning or propagation, but inhibited furrow deepening resulting in regression of the cleavage furrow. Both of these inhibitors also blocked the furrowing Ca(2+) transient, with SKF 96365 having a more profound inhibitory effect than 2-APB. In zebrafish, SOCE does not appear to be required for mitosis or the early stages of cytokinesis during the early embryonic cell division cycles, but it does appear to be essential for maintaining the elevated levels of [Ca(2+)]i for the extended periods that are required during furrow deepening and daughter cell apposition.","PeriodicalId":94228,"journal":{"name":"The International journal of developmental biology","volume":"29 1","pages":"289-301"},"PeriodicalIF":0.0,"publicationDate":"2015-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85001242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}