Pub Date : 2014-11-15DOI: 10.1186/s12899-014-0009-x
Barbara Serrano-Flores, Edith Garay, Francisco G Vázquez-Cuevas, Rogelio O Arellano
Background: The Xenopus oocyte is a useful cell model to study Ca2+ homeostasis and cell cycle regulation, two highly interrelated processes. Here, we used antisense oligonucleotides to investigate the role in the oocyte of stromal interaction molecule (STIM) proteins that are fundamental elements of the store-operated calcium-entry (SOCE) phenomenon, as they are both sensors for Ca2+ concentration in the intracellular reservoirs as well as activators of the membrane channels that allow Ca2+ influx.
Results: Endogenous STIM1 and STIM2 expression was demonstrated, and their synthesis was knocked down 48-72 h after injecting oocytes with specific antisense sequences. Selective elimination of their mRNA and protein expression was confirmed by PCR and Western blot analysis, and we then evaluated the effect of their absence on two endogenous responses: the opening of SOC channels elicited by G protein-coupled receptor (GPCR)-activated Ca2+ release, and the process of maturation stimulated by progesterone. Activation of SOC channels was monitored electrically by measuring the T in response, a Ca2+-influx-dependent Cl- current, while maturation was assessed by germinal vesicle breakdown (GVBD) scoring and electrophysiology.
Conclusions: It was found that STIM2, but not STIM1, was essential in both responses, and T in currents and GVBD were strongly reduced or eliminated in cells devoid of STIM2; STIM1 knockdown had no effect on the maturation process, but it reduced the T in response by 15 to 70%. Thus, the endogenous SOCE response in Xenopus oocytes depended mainly on STIM2, and its expression was necessary for entry into meiosis induced by progesterone.
背景:非洲爪蟾卵母细胞是研究Ca2+稳态和细胞周期调节这两个高度相关的过程的有用细胞模型。在这里,我们使用反义寡核苷酸来研究基质相互作用分子(STIM)蛋白在卵母细胞中的作用,STIM蛋白是储存操作钙进入(SOCE)现象的基本要素,因为它们既是细胞内储层中Ca2+浓度的传感器,也是允许Ca2+内流的膜通道的激活剂。结果:证实了内源性的STIM1和STIM2的表达,并且在注射特定反义序列的卵母细胞后48-72 h,它们的合成被抑制。通过PCR和Western blot分析证实了它们的mRNA和蛋白表达的选择性消除,然后我们评估了它们的缺失对两种内源性反应的影响:G蛋白偶联受体(GPCR)激活的Ca2+释放引发的SOC通道打开,以及黄体酮刺激的成熟过程。通过测量T响应来监测SOC通道的激活,这是一种依赖于Ca2+流入的Cl-电流,而成熟度通过生发囊泡破裂(GVBD)评分和电生理学来评估。结论:发现在这两种反应中,STIM2而不是STIM1是必需的,并且在缺乏STIM2的细胞中,T in current和GVBD强烈减少或消除;STIM1敲低对成熟过程没有影响,但它使T反应降低了15%至70%。由此可见,非洲爪蟾卵母细胞内源性SOCE反应主要依赖于STIM2,其表达是进入黄体酮诱导的减数分裂所必需的。
{"title":"Differential role of STIM1 and STIM2 during transient inward (T in) current generation and the maturation process in the Xenopus oocyte.","authors":"Barbara Serrano-Flores, Edith Garay, Francisco G Vázquez-Cuevas, Rogelio O Arellano","doi":"10.1186/s12899-014-0009-x","DOIUrl":"https://doi.org/10.1186/s12899-014-0009-x","url":null,"abstract":"<p><strong>Background: </strong>The Xenopus oocyte is a useful cell model to study Ca2+ homeostasis and cell cycle regulation, two highly interrelated processes. Here, we used antisense oligonucleotides to investigate the role in the oocyte of stromal interaction molecule (STIM) proteins that are fundamental elements of the store-operated calcium-entry (SOCE) phenomenon, as they are both sensors for Ca2+ concentration in the intracellular reservoirs as well as activators of the membrane channels that allow Ca2+ influx.</p><p><strong>Results: </strong>Endogenous STIM1 and STIM2 expression was demonstrated, and their synthesis was knocked down 48-72 h after injecting oocytes with specific antisense sequences. Selective elimination of their mRNA and protein expression was confirmed by PCR and Western blot analysis, and we then evaluated the effect of their absence on two endogenous responses: the opening of SOC channels elicited by G protein-coupled receptor (GPCR)-activated Ca2+ release, and the process of maturation stimulated by progesterone. Activation of SOC channels was monitored electrically by measuring the T in response, a Ca2+-influx-dependent Cl- current, while maturation was assessed by germinal vesicle breakdown (GVBD) scoring and electrophysiology.</p><p><strong>Conclusions: </strong>It was found that STIM2, but not STIM1, was essential in both responses, and T in currents and GVBD were strongly reduced or eliminated in cells devoid of STIM2; STIM1 knockdown had no effect on the maturation process, but it reduced the T in response by 15 to 70%. Thus, the endogenous SOCE response in Xenopus oocytes depended mainly on STIM2, and its expression was necessary for entry into meiosis induced by progesterone.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s12899-014-0009-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32817271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-11-06DOI: 10.1186/s12899-014-0008-y
Anke Schwarzenberger, Mark Christjani, Alexander Wacker
Background: The widespread occurrence of melatonin in prokaryotes as well as eukaryotes indicates that this indoleamine is considerably old. This high evolutionary age has led to the development of diverse functions of melatonin in different organisms, such as the detoxification of reactive oxygen species and anti-stress effects. In insects, i.e. Drosophila, the addition of melatonin has also been shown to increase the life span of this arthropod, probably by reducing age-related increasing oxidative stress. Although the presence of melatonin was recently found to exist in the ecological and toxicological model organism Daphnia, its function in this cladoceran has thus far not been addressed. Therefore, we challenged Daphnia with three different stressors in order to investigate potential stress-response attenuating effects of melatonin. i) Female and male daphnids were exposed to melatonin in a longevity experiment, ii) Daphnia were confronted with stress signals from the invertebrate predator Chaoborus sp., and iii) Daphnia were grown in high densities, i.e. under crowding-stress conditions.
Results: In our experiments we were able to show that longevity of daphnids was not affected by melatonin. Therefore, age-related increasing oxidative stress was probably not compensated by added melatonin. However, melatonin significantly attenuated Daphnia's response to acute predator stress, i.e. the formation of neckteeth which decrease the ability of the gape-limited predator Chaoborus sp. to handle their prey. In addition, melatonin decreased the extent of crowding-related production of resting eggs of Daphnia.
Conclusions: Our results confirm the effect of melatonin on inhibition of stress-signal responses of Daphnia. Until now, only a single study demonstrated melatonin effects on behavioral responses due to vertebrate kairomones, whereas we clearly show a more general effect of melatonin: i) on morphological predator defense induced by an invertebrate kairomone and ii) on life history characteristics transmitted by chemical cues from conspecifics. Therefore, we could generally confirm that melatonin plays a role in the attenuation of responses to different stressors in Daphnia.
{"title":"Longevity of Daphnia and the attenuation of stress responses by melatonin.","authors":"Anke Schwarzenberger, Mark Christjani, Alexander Wacker","doi":"10.1186/s12899-014-0008-y","DOIUrl":"https://doi.org/10.1186/s12899-014-0008-y","url":null,"abstract":"<p><strong>Background: </strong>The widespread occurrence of melatonin in prokaryotes as well as eukaryotes indicates that this indoleamine is considerably old. This high evolutionary age has led to the development of diverse functions of melatonin in different organisms, such as the detoxification of reactive oxygen species and anti-stress effects. In insects, i.e. Drosophila, the addition of melatonin has also been shown to increase the life span of this arthropod, probably by reducing age-related increasing oxidative stress. Although the presence of melatonin was recently found to exist in the ecological and toxicological model organism Daphnia, its function in this cladoceran has thus far not been addressed. Therefore, we challenged Daphnia with three different stressors in order to investigate potential stress-response attenuating effects of melatonin. i) Female and male daphnids were exposed to melatonin in a longevity experiment, ii) Daphnia were confronted with stress signals from the invertebrate predator Chaoborus sp., and iii) Daphnia were grown in high densities, i.e. under crowding-stress conditions.</p><p><strong>Results: </strong>In our experiments we were able to show that longevity of daphnids was not affected by melatonin. Therefore, age-related increasing oxidative stress was probably not compensated by added melatonin. However, melatonin significantly attenuated Daphnia's response to acute predator stress, i.e. the formation of neckteeth which decrease the ability of the gape-limited predator Chaoborus sp. to handle their prey. In addition, melatonin decreased the extent of crowding-related production of resting eggs of Daphnia.</p><p><strong>Conclusions: </strong>Our results confirm the effect of melatonin on inhibition of stress-signal responses of Daphnia. Until now, only a single study demonstrated melatonin effects on behavioral responses due to vertebrate kairomones, whereas we clearly show a more general effect of melatonin: i) on morphological predator defense induced by an invertebrate kairomone and ii) on life history characteristics transmitted by chemical cues from conspecifics. Therefore, we could generally confirm that melatonin plays a role in the attenuation of responses to different stressors in Daphnia.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s12899-014-0008-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32795256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-09-04DOI: 10.1186/s12899-014-0005-1
Benjamin Vandendriessche, An Goethals, Alba Simats, Evelien Van Hamme, Peter Brouckaert, Anje Cauwels
Background: MAPK-activated protein kinase 2 (MK2) plays a pivotal role in the cell response to (inflammatory) stress. Among others, MK2 is known to be involved in the regulation of cytokine mRNA metabolism and regulation of actin cytoskeleton dynamics. Previously, MK2-deficient mice were shown to be highly resistant to LPS/d-Galactosamine-induced hepatitis. Additionally, research in various disease models has indicated the kinase as an interesting inhibitory drug target for various acute or chronic inflammatory diseases.
Results: We show that in striking contrast to the known resistance of MK2-deficient mice to a challenge with LPS/D-Gal, a low dose of tumor necrosis factor (TNF) causes hyperacute mortality via an oxidative stress driven mechanism. We identified in vivo defects in the stress fiber response in endothelial cells, which could have resulted in reduced resistance of the endothelial barrier to deal with exposure to oxidative stress. In addition, MK2-deficient mice were found to be more sensitive to cecal ligation and puncture-induced sepsis.
Conclusions: The capacity of the endothelial barrier to deal with inflammatory and oxidative stress is imperative to allow a regulated immune response and maintain endothelial barrier integrity. Our results indicate that, considering the central role of TNF in pro-inflammatory signaling, therapeutic strategies examining pharmacological inhibition of MK2 should take potentially dangerous side effects at the level of endothelial barrier integrity into account.
{"title":"MAPK-activated protein kinase 2-deficiency causes hyperacute tumor necrosis factor-induced inflammatory shock.","authors":"Benjamin Vandendriessche, An Goethals, Alba Simats, Evelien Van Hamme, Peter Brouckaert, Anje Cauwels","doi":"10.1186/s12899-014-0005-1","DOIUrl":"https://doi.org/10.1186/s12899-014-0005-1","url":null,"abstract":"<p><strong>Background: </strong>MAPK-activated protein kinase 2 (MK2) plays a pivotal role in the cell response to (inflammatory) stress. Among others, MK2 is known to be involved in the regulation of cytokine mRNA metabolism and regulation of actin cytoskeleton dynamics. Previously, MK2-deficient mice were shown to be highly resistant to LPS/d-Galactosamine-induced hepatitis. Additionally, research in various disease models has indicated the kinase as an interesting inhibitory drug target for various acute or chronic inflammatory diseases.</p><p><strong>Results: </strong>We show that in striking contrast to the known resistance of MK2-deficient mice to a challenge with LPS/D-Gal, a low dose of tumor necrosis factor (TNF) causes hyperacute mortality via an oxidative stress driven mechanism. We identified in vivo defects in the stress fiber response in endothelial cells, which could have resulted in reduced resistance of the endothelial barrier to deal with exposure to oxidative stress. In addition, MK2-deficient mice were found to be more sensitive to cecal ligation and puncture-induced sepsis.</p><p><strong>Conclusions: </strong>The capacity of the endothelial barrier to deal with inflammatory and oxidative stress is imperative to allow a regulated immune response and maintain endothelial barrier integrity. Our results indicate that, considering the central role of TNF in pro-inflammatory signaling, therapeutic strategies examining pharmacological inhibition of MK2 should take potentially dangerous side effects at the level of endothelial barrier integrity into account.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s12899-014-0005-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32637748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-08-27DOI: 10.1186/s12899-014-0006-0
Hernan P Fainberg, Kayleigh L Almond, Dongfang Li, Cyril Rauch, Paul Bikker, Michael E Symonds, Alison Mostyn
Background: Maternal diet during pregnancy can modulate skeletal muscle development of the offspring. Previous studies in pigs have indicated that a fat supplemented diet during pregnancy can improve piglet outcome, however, this is in contrast to human studies suggesting adverse effects of saturated fats during pregnancy. This study aimed to investigate the impact of a fat supplemented (palm oil) "high fat" diet on skeletal muscle development in a porcine model. Histological and metabolic features of the biceps femoris muscle obtained from 7-day-old piglets born to sows assigned to either a commercial (C, n = 7) or to an isocaloric fat supplementation diet ("high fat" HF, n = 7) during pregnancy were assessed.
Results: Offspring exposed to a maternal HF diet demonstrated enhanced muscular development, reflected by an increase in fractional growth rate, rise in myofibre cross-sectional area, increased storage of glycogen and reduction in lipid staining of myofibres. Although both groups had similar intramuscular protein and triglyceride concentrations, the offspring born to HF mothers had a higher proportion of arachidonic acid (C20:4n6) and a reduction in α-linolenic acid (C18:3n3) compared to C group offspring. The HF group muscle also exhibited a higher ratio of C20:3n6 to C20:4n6 and total n-6 to n-3 in conjunction with up-regulation of genes associated with free fatty acid uptake and biogenesis.
Conclusion: In conclusion, a HF gestational diet accelerates the maturation of offspring biceps femoris muscle, reflected in increased glycolytic metabolism and fibre cross sectional area, differences accompanied with a potential resetting of myofibre nutrient uptake.
背景:孕期母体饮食可调节子代骨骼肌发育。先前对猪的研究表明,怀孕期间的脂肪补充饲料可以改善仔猪的结局,然而,这与人类研究表明的怀孕期间饱和脂肪的不利影响形成鲜明对比。这项研究旨在调查一种脂肪补充剂(棕榈油)的影响“高脂肪”饮食对猪骨骼肌发育的影响在妊娠期间,母猪分别饲喂商业饲粮(C, n = 7)和等热量脂肪补充饲粮(“高脂肪”HF, n = 7),对仔猪所生的7日龄仔猪的股二头肌的组织学和代谢特征进行了评估。结果:暴露于母体HF饮食的后代表现出增强的肌肉发育,反映在分数生长速率的增加,肌纤维横截面积的增加,糖原储存的增加和肌纤维脂质染色的减少。虽然两组的肌内蛋白和甘油三酯浓度相似,但与C组的后代相比,HF母亲所生的后代花生四烯酸(C20:4n6)的比例更高,α-亚麻酸(C18:3n3)的比例更低。HF组肌肉中C20:3n6比C20:4n6和总n-6比n-3的比例也更高,这与游离脂肪酸摄取和生物发生相关基因的上调有关。结论:总之,HF妊娠日粮加速了子代股二头肌的成熟,表现为糖酵解代谢和纤维横截面积的增加,这种差异伴随着肌纤维营养摄取的潜在重置。
{"title":"Impact of maternal dietary fat supplementation during gestation upon skeletal muscle in neonatal pigs.","authors":"Hernan P Fainberg, Kayleigh L Almond, Dongfang Li, Cyril Rauch, Paul Bikker, Michael E Symonds, Alison Mostyn","doi":"10.1186/s12899-014-0006-0","DOIUrl":"https://doi.org/10.1186/s12899-014-0006-0","url":null,"abstract":"<p><strong>Background: </strong>Maternal diet during pregnancy can modulate skeletal muscle development of the offspring. Previous studies in pigs have indicated that a fat supplemented diet during pregnancy can improve piglet outcome, however, this is in contrast to human studies suggesting adverse effects of saturated fats during pregnancy. This study aimed to investigate the impact of a fat supplemented (palm oil) \"high fat\" diet on skeletal muscle development in a porcine model. Histological and metabolic features of the biceps femoris muscle obtained from 7-day-old piglets born to sows assigned to either a commercial (C, n = 7) or to an isocaloric fat supplementation diet (\"high fat\" HF, n = 7) during pregnancy were assessed.</p><p><strong>Results: </strong>Offspring exposed to a maternal HF diet demonstrated enhanced muscular development, reflected by an increase in fractional growth rate, rise in myofibre cross-sectional area, increased storage of glycogen and reduction in lipid staining of myofibres. Although both groups had similar intramuscular protein and triglyceride concentrations, the offspring born to HF mothers had a higher proportion of arachidonic acid (C20:4n6) and a reduction in α-linolenic acid (C18:3n3) compared to C group offspring. The HF group muscle also exhibited a higher ratio of C20:3n6 to C20:4n6 and total n-6 to n-3 in conjunction with up-regulation of genes associated with free fatty acid uptake and biogenesis.</p><p><strong>Conclusion: </strong>In conclusion, a HF gestational diet accelerates the maturation of offspring biceps femoris muscle, reflected in increased glycolytic metabolism and fibre cross sectional area, differences accompanied with a potential resetting of myofibre nutrient uptake.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s12899-014-0006-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32640247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rainer U Pliquett, Sebastian Benkhoff, Oliver Jung, Ralf P Brandes
Background: Dysregulation of the autonomic nervous system is frequent in subjects with cardiovascular disease. The contribution of different forms of renovascular hypertension and the mechanisms contributing to autonomic dysfunction in hypertension are incompletely understood. Here, murine models of renovascular hypertension with preserved (2-kidneys-1 clip, 2K1C) and reduced (1-kidney-1 clip, 1K1C) kidney mass were studied with regard to autonomic nervous system regulation (sympathetic tone: power-spectral analysis of systolic blood pressure; parasympathetic tone: power-spectral analysis of heart rate) and baroreflex sensitivity of heart rate by spontaneous, concomitant changes of systolic blood pressure and pulse interval. Involvement of the renin-angiotensin system and the rho-kinase pathway were determined by application of inhibitors.
Results: C57BL6N mice (6 to 11) with reduced kidney mass (1K1C) or with preserved kidney mass (2K1C) developed a similar degree of hypertension. In comparison to control mice, both models presented with a significantly increased sympathetic tone and lower baroreflex sensitivity of heart rate. However, only 2K1C animals had a lower parasympathetic tone, whereas urinary norepinephrine excretion was reduced in the 1K1C model. Rho kinase inhibition given to a subset of 1K1C and 2K1C animals improved baroreflex sensitivity of heart rate selectively in the 1K1C model. Rho kinase inhibition had no additional effects on autonomic nervous system in either model of renovascular hypertension and did not change the blood pressure. Blockade of AT1 receptors (in 2K1C animals) normalized the sympathetic tone, decreased resting heart rate, improved baroreflex sensitivity of heart rate and parasympathetic tone.
Conclusions: Regardless of residual renal mass, blood pressure and sympathetic tone are increased, whereas baroreflex sensitivity is depressed in murine models of renovascular hypertension. Reduced norepinephrine excretion and/or degradation might contribute to sympathoactivation in renovascular hypertension with reduced renal mass (1K1C). Overall, the study helps to direct research to optimize medical therapy of hypertension.
{"title":"Sympathoactivation and rho-kinase-dependent baroreflex function in experimental renovascular hypertension with reduced kidney mass.","authors":"Rainer U Pliquett, Sebastian Benkhoff, Oliver Jung, Ralf P Brandes","doi":"10.1186/1472-6793-14-4","DOIUrl":"https://doi.org/10.1186/1472-6793-14-4","url":null,"abstract":"<p><strong>Background: </strong>Dysregulation of the autonomic nervous system is frequent in subjects with cardiovascular disease. The contribution of different forms of renovascular hypertension and the mechanisms contributing to autonomic dysfunction in hypertension are incompletely understood. Here, murine models of renovascular hypertension with preserved (2-kidneys-1 clip, 2K1C) and reduced (1-kidney-1 clip, 1K1C) kidney mass were studied with regard to autonomic nervous system regulation (sympathetic tone: power-spectral analysis of systolic blood pressure; parasympathetic tone: power-spectral analysis of heart rate) and baroreflex sensitivity of heart rate by spontaneous, concomitant changes of systolic blood pressure and pulse interval. Involvement of the renin-angiotensin system and the rho-kinase pathway were determined by application of inhibitors.</p><p><strong>Results: </strong>C57BL6N mice (6 to 11) with reduced kidney mass (1K1C) or with preserved kidney mass (2K1C) developed a similar degree of hypertension. In comparison to control mice, both models presented with a significantly increased sympathetic tone and lower baroreflex sensitivity of heart rate. However, only 2K1C animals had a lower parasympathetic tone, whereas urinary norepinephrine excretion was reduced in the 1K1C model. Rho kinase inhibition given to a subset of 1K1C and 2K1C animals improved baroreflex sensitivity of heart rate selectively in the 1K1C model. Rho kinase inhibition had no additional effects on autonomic nervous system in either model of renovascular hypertension and did not change the blood pressure. Blockade of AT1 receptors (in 2K1C animals) normalized the sympathetic tone, decreased resting heart rate, improved baroreflex sensitivity of heart rate and parasympathetic tone.</p><p><strong>Conclusions: </strong>Regardless of residual renal mass, blood pressure and sympathetic tone are increased, whereas baroreflex sensitivity is depressed in murine models of renovascular hypertension. Reduced norepinephrine excretion and/or degradation might contribute to sympathoactivation in renovascular hypertension with reduced renal mass (1K1C). Overall, the study helps to direct research to optimize medical therapy of hypertension.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1472-6793-14-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32438803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jennifer C Jones, Kellie A Kroscher, Anna C Dilger
Background: Genes that decline in expression with age and are thought to coordinate growth cessation have been identified in various organs, but their expression in skeletal muscle is unknown. Therefore, our objective was to determine expression of these genes (Ezh2, Gpc3, Mdk, Mest, Mycn, Peg3, and Plagl1) in skeletal muscle from birth to maturity. We hypothesized that expression of these genes would decline with age in skeletal muscle but differ between sexes and between wild type and myostatin null mice.
Results: Female and male wild type and myostatin null mice (C57BL/6J background) were sacrificed by carbon dioxide asphyxiation followed by decapitation at d -7, 0, 21, 42, and 70 days of age. Whole bodies at d -7, all muscles from both hind limbs at d 0, and bicep femoris muscle from d 21, 42 and 70 were collected. Gene expression was determined by quantitative real-time PCR. In general, expression of these growth-regulating genes was reduced at d 21 compared with day 0 and d -7. Expression of Gpc3, Mest, and Peg3 was further reduced at d 42 and 70 compared with d 21, however the expression of Mycn increased from d 21 to d 42 and 70. Myostatin null mice, as expected, were heavier with increased biceps femoris weight at d 70. However, with respect to sex and genotype, there were few differences in expression. Expression of Ezh2 was increased at d 70 and expression of Mdk was increased at d 21 in myostatin null mice compared with wild type, but no other genotype effects were present. Expression of Mdk was increased in females compared to males at d 70, but no other sex effects were present.
Conclusions: Overall, these data suggest the downregulation of these growth-regulating genes with age might play a role in the coordinated cessation of muscle growth similar to organ growth but likely have a limited role in the differences between sexes or genotypes.
{"title":"Reductions in expression of growth regulating genes in skeletal muscle with age in wild type and myostatin null mice.","authors":"Jennifer C Jones, Kellie A Kroscher, Anna C Dilger","doi":"10.1186/1472-6793-14-3","DOIUrl":"https://doi.org/10.1186/1472-6793-14-3","url":null,"abstract":"<p><strong>Background: </strong>Genes that decline in expression with age and are thought to coordinate growth cessation have been identified in various organs, but their expression in skeletal muscle is unknown. Therefore, our objective was to determine expression of these genes (Ezh2, Gpc3, Mdk, Mest, Mycn, Peg3, and Plagl1) in skeletal muscle from birth to maturity. We hypothesized that expression of these genes would decline with age in skeletal muscle but differ between sexes and between wild type and myostatin null mice.</p><p><strong>Results: </strong>Female and male wild type and myostatin null mice (C57BL/6J background) were sacrificed by carbon dioxide asphyxiation followed by decapitation at d -7, 0, 21, 42, and 70 days of age. Whole bodies at d -7, all muscles from both hind limbs at d 0, and bicep femoris muscle from d 21, 42 and 70 were collected. Gene expression was determined by quantitative real-time PCR. In general, expression of these growth-regulating genes was reduced at d 21 compared with day 0 and d -7. Expression of Gpc3, Mest, and Peg3 was further reduced at d 42 and 70 compared with d 21, however the expression of Mycn increased from d 21 to d 42 and 70. Myostatin null mice, as expected, were heavier with increased biceps femoris weight at d 70. However, with respect to sex and genotype, there were few differences in expression. Expression of Ezh2 was increased at d 70 and expression of Mdk was increased at d 21 in myostatin null mice compared with wild type, but no other genotype effects were present. Expression of Mdk was increased in females compared to males at d 70, but no other sex effects were present.</p><p><strong>Conclusions: </strong>Overall, these data suggest the downregulation of these growth-regulating genes with age might play a role in the coordinated cessation of muscle growth similar to organ growth but likely have a limited role in the differences between sexes or genotypes.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1472-6793-14-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32216464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sven Martin Jørgensen, Vicente Castro, Aleksei Krasnov, Jacob Torgersen, Gerrit Timmerhaus, Ernst Morten Hevrøy, Tom Johnny Hansen, Sissel Susort, Olav Breck, Harald Takle
Background: Atlantic salmon aquaculture operations in the Northern hemisphere experience large seasonal fluctuations in seawater temperature. With summer temperatures often peaking around 18-20°C there is growing concern about the effects on fish health and performance. Since the heart has a major role in the physiological plasticity and acclimation to different thermal conditions in fish, we wanted to investigate how three and eight weeks exposure of adult Atlantic salmon to 19°C, previously shown to significantly reduce growth performance, affected expression of relevant genes and proteins in cardiac tissues under experimental conditions.
Results: Transcriptional responses in cardiac tissues after three and eight weeks exposure to 19°C (compared to thermal preference, 14°C) were analyzed with cDNA microarrays and validated by expression analysis of selected genes and proteins using real-time qPCR and immunofluorescence microscopy. Up-regulation of heat shock proteins and cell signaling genes may indicate involvement of the unfolded protein response in long-term acclimation to elevated temperature. Increased immunofluorescence staining of inducible nitric oxide synthase in spongy and compact myocardium as well as increased staining of vascular endothelial growth factor in epicardium could reflect induced vascularization and vasodilation, possibly related to increased oxygen demand. Increased staining of collagen I in the compact myocardium of 19°C fish may be indicative of a remodeling of connective tissue with long-term warm acclimation. Finally, higher abundance of transcripts for genes involved in innate cellular immunity and lower abundance of transcripts for humoral immune components implied altered immune competence in response to elevated temperature.
Conclusions: Long-term exposure of Atlantic salmon to 19°C resulted in cardiac gene and protein expression changes indicating that the unfolded protein response, vascularization, remodeling of connective tissue and altered innate immune responses were part of the cardiac acclimation or response to elevated temperature.
{"title":"Cardiac responses to elevated seawater temperature in Atlantic salmon.","authors":"Sven Martin Jørgensen, Vicente Castro, Aleksei Krasnov, Jacob Torgersen, Gerrit Timmerhaus, Ernst Morten Hevrøy, Tom Johnny Hansen, Sissel Susort, Olav Breck, Harald Takle","doi":"10.1186/1472-6793-14-2","DOIUrl":"https://doi.org/10.1186/1472-6793-14-2","url":null,"abstract":"<p><strong>Background: </strong>Atlantic salmon aquaculture operations in the Northern hemisphere experience large seasonal fluctuations in seawater temperature. With summer temperatures often peaking around 18-20°C there is growing concern about the effects on fish health and performance. Since the heart has a major role in the physiological plasticity and acclimation to different thermal conditions in fish, we wanted to investigate how three and eight weeks exposure of adult Atlantic salmon to 19°C, previously shown to significantly reduce growth performance, affected expression of relevant genes and proteins in cardiac tissues under experimental conditions.</p><p><strong>Results: </strong>Transcriptional responses in cardiac tissues after three and eight weeks exposure to 19°C (compared to thermal preference, 14°C) were analyzed with cDNA microarrays and validated by expression analysis of selected genes and proteins using real-time qPCR and immunofluorescence microscopy. Up-regulation of heat shock proteins and cell signaling genes may indicate involvement of the unfolded protein response in long-term acclimation to elevated temperature. Increased immunofluorescence staining of inducible nitric oxide synthase in spongy and compact myocardium as well as increased staining of vascular endothelial growth factor in epicardium could reflect induced vascularization and vasodilation, possibly related to increased oxygen demand. Increased staining of collagen I in the compact myocardium of 19°C fish may be indicative of a remodeling of connective tissue with long-term warm acclimation. Finally, higher abundance of transcripts for genes involved in innate cellular immunity and lower abundance of transcripts for humoral immune components implied altered immune competence in response to elevated temperature.</p><p><strong>Conclusions: </strong>Long-term exposure of Atlantic salmon to 19°C resulted in cardiac gene and protein expression changes indicating that the unfolded protein response, vascularization, remodeling of connective tissue and altered innate immune responses were part of the cardiac acclimation or response to elevated temperature.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1472-6793-14-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32162950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Calvin Wu, Kanishk Sharma, Kyle Laster, Mohamed Hersi, Christina Torres, Thomas J Lukas, Ernest J Moore
Background: KCNQx genes encode slowly activating-inactivating K+ channels, are linked to physiological signal transduction pathways, and mutations in them underlie diseases such as long QT syndrome (KCNQ1), epilepsy in adults (KCNQ2/3), benign familial neonatal convulsions in children (KCNQ3), and hearing loss or tinnitus in humans (KCNQ4, but not KCNQ5). Identification of kcnqx potassium channel transcripts in zebrafish (Danio rerio) remains to be fully characterized although some genes have been mapped to the genome. Using zebrafish genome resources as the source of putative kcnq sequences, we investigated the expression of kcnq1-5 in heart, brain and ear tissues.
Results: Overall expression of the kcnqx channel transcripts is similar to that found in mammals. We found that kcnq1 expression was highest in the heart, and also present in the ear and brain. kcnq2 was lowest in the heart, while kcnq3 was highly expressed in the brain, heart and ear. kcnq5 expression was highest in the ear. We analyzed zebrafish genomic clones containing putative kcnq4 sequences to identify transcripts and protein for this highly conserved member of the Kcnq channel family. The zebrafish appears to have two kcnq4 genes that produce distinct mRNA species in brain, ear, and heart tissues.
Conclusions: We conclude that the zebrafish is an attractive model for the study of the KCNQ (Kv7) superfamily of genes, and are important to processes involved in neuronal excitability, cardiac anomalies, epileptic seizures, and hearing loss or tinnitus.
{"title":"Kcnq1-5 (Kv7.1-5) potassium channel expression in the adult zebrafish.","authors":"Calvin Wu, Kanishk Sharma, Kyle Laster, Mohamed Hersi, Christina Torres, Thomas J Lukas, Ernest J Moore","doi":"10.1186/1472-6793-14-1","DOIUrl":"https://doi.org/10.1186/1472-6793-14-1","url":null,"abstract":"<p><strong>Background: </strong>KCNQx genes encode slowly activating-inactivating K+ channels, are linked to physiological signal transduction pathways, and mutations in them underlie diseases such as long QT syndrome (KCNQ1), epilepsy in adults (KCNQ2/3), benign familial neonatal convulsions in children (KCNQ3), and hearing loss or tinnitus in humans (KCNQ4, but not KCNQ5). Identification of kcnqx potassium channel transcripts in zebrafish (Danio rerio) remains to be fully characterized although some genes have been mapped to the genome. Using zebrafish genome resources as the source of putative kcnq sequences, we investigated the expression of kcnq1-5 in heart, brain and ear tissues.</p><p><strong>Results: </strong>Overall expression of the kcnqx channel transcripts is similar to that found in mammals. We found that kcnq1 expression was highest in the heart, and also present in the ear and brain. kcnq2 was lowest in the heart, while kcnq3 was highly expressed in the brain, heart and ear. kcnq5 expression was highest in the ear. We analyzed zebrafish genomic clones containing putative kcnq4 sequences to identify transcripts and protein for this highly conserved member of the Kcnq channel family. The zebrafish appears to have two kcnq4 genes that produce distinct mRNA species in brain, ear, and heart tissues.</p><p><strong>Conclusions: </strong>We conclude that the zebrafish is an attractive model for the study of the KCNQ (Kv7) superfamily of genes, and are important to processes involved in neuronal excitability, cardiac anomalies, epileptic seizures, and hearing loss or tinnitus.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1472-6793-14-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32144152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RETRACTION: The effect of marathon on mRNA expression of anti-apoptotic and pro-apoptotic proteins and sirtuins family in male recreational long-distance runners.","authors":"","doi":"10.1186/1472-6793-13-13","DOIUrl":"https://doi.org/10.1186/1472-6793-13-13","url":null,"abstract":"","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1472-6793-13-13","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32018697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: Contractions and relaxations of the muscle layers within the digestive tract alter the external diameter and the internal pressures. These changes in diameter and pressure move digesting food and waste products. Defining these complex relationships is a fundamental step for neurogastroenterologists to be able define normal and abnormal gut motility.
Results: Utilising an in vitro technique that allows for the simultaneous recording of intraluminal pressure (manometry) and gut diameter (video) in an isolated section of rabbit colon, we developed a technique to help define the mechanical states of the muscle at any point in space and time during actual peristaltic movements. This was achieved by directly relating the changes in pressure to the changes in diameter along the length of the gut studied. For each individual measure of pressure or diameter, 3 dynamic state components were identified; increasing or decreasing changes or a stable period. Two additional static state components, fully contracted and fully distended, were defined for the diameter. Then qualitative mechanical states of the muscle activity were defined as combinations of these state components. A hidden Markov model was used to correlate adjacent-in-time samples, and the Viterbi algorithm was used to infer the most likely sequence of mechanical states based on the observed data. From this a spatiotemporal map of the mechanical states was produced, showing the regions of active contractions, active relaxations, or passive states along the length of the gut throughout the entire recording period.
Conclusions: The identification of mechanical muscles states based on gut diameter and intraluminal pressure was possible by modelling muscle activation with a hidden Markov model.
{"title":"Inference of mechanical states of intestinal motor activity using hidden Markov models.","authors":"Lukasz Wiklendt, Marcello Costa, Phil G Dinning","doi":"10.1186/1472-6793-13-14","DOIUrl":"https://doi.org/10.1186/1472-6793-13-14","url":null,"abstract":"<p><strong>Background: </strong>Contractions and relaxations of the muscle layers within the digestive tract alter the external diameter and the internal pressures. These changes in diameter and pressure move digesting food and waste products. Defining these complex relationships is a fundamental step for neurogastroenterologists to be able define normal and abnormal gut motility.</p><p><strong>Results: </strong>Utilising an in vitro technique that allows for the simultaneous recording of intraluminal pressure (manometry) and gut diameter (video) in an isolated section of rabbit colon, we developed a technique to help define the mechanical states of the muscle at any point in space and time during actual peristaltic movements. This was achieved by directly relating the changes in pressure to the changes in diameter along the length of the gut studied. For each individual measure of pressure or diameter, 3 dynamic state components were identified; increasing or decreasing changes or a stable period. Two additional static state components, fully contracted and fully distended, were defined for the diameter. Then qualitative mechanical states of the muscle activity were defined as combinations of these state components. A hidden Markov model was used to correlate adjacent-in-time samples, and the Viterbi algorithm was used to infer the most likely sequence of mechanical states based on the observed data. From this a spatiotemporal map of the mechanical states was produced, showing the regions of active contractions, active relaxations, or passive states along the length of the gut throughout the entire recording period.</p><p><strong>Conclusions: </strong>The identification of mechanical muscles states based on gut diameter and intraluminal pressure was possible by modelling muscle activation with a hidden Markov model.</p>","PeriodicalId":35905,"journal":{"name":"BMC Physiology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/1472-6793-13-14","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31947748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}