The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands.Using a hydroponic culture system,the secretion and accumulation of Na+ and K+ in Tamarix ramosissima and T...The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands.Using a hydroponic culture system,the secretion and accumulation of Na+ and K+ in Tamarix ramosissima and T.laxa under different salt stresses (NaCl,KCl and NaCl+KCl) were studied.Additionally,the effects of salt gland inhibitors (orthovanadate,Ba2+,ouabain,tetraethylammonium (TEA) and verapamil) on Na+ and K+ secretion and accumulation were examined.Treatment with NaCl (at 0-200 mmol L 1 levels) significantly increased Na+ secretion,whereas KCl treatment (at 0-200 mmol L 1 levels) significantly increased K+ secretion.The ratio of secretion to accumulation of Na+ was higher than that of K+.The changes in Na+ and K+ secretion differed after adding different ions into the single-salt solutions.Addition of NaCl to the KCl solution (at 100 mmol L 1 level,respectively) led to a significant decrease in K+ secretion rate,whereas addition of KCl to the NaCl solution (at 100 mmol L 1 level,respectively) had little impact on the Na+ secretion rate.These results indicated that Na+ secretion in Tamarix was highly selective.In addition,Na+ secretion was significantly inhibited by orthovanadate,ouabain,TEA and verapamil,and K+ secretion was significantly inhibited by ouabain,TEA and verapamil.The different impacts of orthovanadate on Na+ and K+ secretion might be the primary cause for the different Na+ and K+ secretion abilities of multicellular salt glands in Tamarix.展开更多
microRNAs(miRNAs)have emerged as key components in the eukaryotic gene regulatory network.We and others have previously identified many miRNAs in a unicellular green alga,Chlamydomonas reinhardtii.To investigate wheth...microRNAs(miRNAs)have emerged as key components in the eukaryotic gene regulatory network.We and others have previously identified many miRNAs in a unicellular green alga,Chlamydomonas reinhardtii.To investigate whether miRNA-mediated gene regulation is a general mechanism in green algae and how miRNAs have been evolved in the green algal lineage,we examined small RNAs in Volvox carteri,a multicellular species in the same family with Chlamydomonas reinhardtii.We identified 174 miRNAs in Volvox,with many of them being highly enriched in gonidia or somatic cells.The targets of the miRNAs were predicted and many of them were subjected to miRNA-mediated cleavage in vivo,suggesting that miRNAs play regulatory roles in the biology of green algae.Our catalog of miRNAs and their targets provides a resource for further studies on the evolution,biological functions,and genomic properties of miRNAs in green algae.展开更多
背景:组织工程骨构建体的血管化性能不足是限制骨组织工程用于修复大尺寸骨缺损临床应用的主要挑战。目的:对近年来利用骨形成细胞和血管生成细胞构建组织工程构建体(基于支架或无支架)在骨修复中的应用进行了概述,以期实现组织工程骨...背景:组织工程骨构建体的血管化性能不足是限制骨组织工程用于修复大尺寸骨缺损临床应用的主要挑战。目的:对近年来利用骨形成细胞和血管生成细胞构建组织工程构建体(基于支架或无支架)在骨修复中的应用进行了概述,以期实现组织工程骨可持续的血管生成及生成功能完善的血管,从而提高骨组织工程在大尺寸骨缺损修复应用中的细胞存活率、并为促进骨的形成和重塑提供参考。方法:应用计算机对中国知网、PubMed及Web of Science数据库2000-2021年发表的文献进行了检索,中文检索词为“骨组织工程、成骨成血管、多细胞”,英文检索词为“Bone Tissue Engineering,Osteogenesis and angiogenesis,Multicellular”,根据纳入和排除标准,最终纳入63篇文献进行结果分析。结果与结论:①目前最常用的骨形成细胞主要有间充质干细胞、脂肪干细胞和成骨细胞,常用的血管生成细胞有人脐静脉内皮细胞和内皮祖细胞。②支架内包封细胞在实现各类细胞的精准定位方面优于在支架上接种细胞。③将两种单一细胞膜片相叠加或者共培养单层细胞膜片相叠加的方法,可以调控各类细胞的位置,从而构建血管化网络。④目前,基于支架的组织工程技术还需克服支架降解速率与组织再生速率的不匹配性、细胞与生物材料相互作用不可控等问题,而基于无支架细胞膜片的组织工程还需要克服力学强度低的难题。⑤未来研究需构建具有临床所需大小的功能性3D血管化组织工程骨,还需关注包括细胞培养和生物学作用机制;结合组织工程、细胞工程和基因工程构建组织工程骨,有望实现刺激早期血管生成、保持血液循环,防止构建体内部的细胞死亡,并起到加速构建体修复临床大体积骨缺损的作用。展开更多
Multicellular magnetotactic prokaryotes （MMPs） are a group of aggregates composed of 7-45 gram-negative cells synthesizing intracellular magnetic crystals. Although they are thought to be globally distributed, MMPs ...Multicellular magnetotactic prokaryotes （MMPs） are a group of aggregates composed of 7-45 gram-negative cells synthesizing intracellular magnetic crystals. Although they are thought to be globally distributed, MMPs have been observed only in marine environments in America and Europe. Most MMPs share a rosette-like morphology and biomineralize iron sulfide crystals. In the present study, abundant MMPs were observed, with a density of 26 ind./cm^3, in the sediments of a coastal lagoon, Lake Yuehu, in the Yellow Sea. Optical microscopy showed that all of them were rosette shaped with a diameter of 5.5±0.8 μm. Transmission electron microscopy revealed that these MMPs were composed of 10- 16 ovoid cells and flagellated peritrichously. High-resolution transmission electron microscopy and energy dispersive X-ray analysis indicated that they biomineralized bullet-shaped magnetite crystals in highly organized parallel chains within which the magnetosomes were oriented in the same direction. This is the first report of MMPs from Asia and demonstrates the ubiquitous distribution of MMPs.展开更多
Following myocardial infarction(MI), cardiomyocytes and infarct size are the focus of our attention when evaluating the extent of cardiac injury, efficacy of therapies or success in repairing the damaged heart by stem...Following myocardial infarction(MI), cardiomyocytes and infarct size are the focus of our attention when evaluating the extent of cardiac injury, efficacy of therapies or success in repairing the damaged heart by stem cell therapy. Numerous interventions have been shown by pre-clinical studies to be effective in limiting infarct size, and yet clinical trials designed accordingly have yielded disappointing outcomes. The ultimate goal of cardiac protection is to limit the adverse cardiac remodeling. Accumulating studies have revealed that post-infarct remodeling can be attenuated without infarct size limitation. To reconcile this, one needs to appreciate the significance of various cellular and acellular myocardial components that, like cardiomyocytes, undergo significant damage and dysfunction, which impact the ultimate cardiac injury and remodelling. Microvascular injury following ischemia-reperfusion may influence infarct size and promote inflammation. Myocardial injury evokes innate immunity with massive inflammatory infiltration that, although essential for the healing process, exacerbates myocardial injury and damage to extracellular matrix leading to dilative remodeling. It is also important to consider the multiple non-cardiomyocyte components in evaluating therapeutic efficacy. Current research indicates the pivotal role of these components in achieving cardiac regeneration by cell therapy. This review summarizes findings in this field, highlights a broad consideration of therapeutic targets,and recommends cardiac remodeling as the ultimate target.展开更多
Recent studies have indicated that a special type of small noncoding RNAs, phased small-interfering RNAs(phasiRNAs) play crucial roles in many cellular processes of plant development. PhasiRNAs are generated from long...Recent studies have indicated that a special type of small noncoding RNAs, phased small-interfering RNAs(phasiRNAs) play crucial roles in many cellular processes of plant development. PhasiRNAs are generated from long RNA precursors at intervals of 21 or 24 nt in plants, and they are produced from both protein-coding gene and long noncoding RNA genes. Different from those in eudicots, grass phasiRNAs include a special class of small RNAs that are specifically expressed in reproductive organs.These grass phasiRNAs are associated with gametogenesis, especially with anther development and male fertility. In this review,we summarized current knowledge on these small noncoding RNAs in male germ cells and their possible biological functions and mechanisms in grass species.展开更多
基金supported by the Special Fund for Public Welfare Industrial(Agriculture) Research of China(Grant No. 200903001)Chinese Academy of Sciences Innovation Base Project for Agriculture(Grant No. KSCX1-YW-09-10),the Chinese Academy of Sciences Agricultural Projects (Grant No. KSCX2-YW-N-41)
文摘The present study aimed to determine the mechanism of cation-selective secretion by multicellular salt glands.Using a hydroponic culture system,the secretion and accumulation of Na+ and K+ in Tamarix ramosissima and T.laxa under different salt stresses (NaCl,KCl and NaCl+KCl) were studied.Additionally,the effects of salt gland inhibitors (orthovanadate,Ba2+,ouabain,tetraethylammonium (TEA) and verapamil) on Na+ and K+ secretion and accumulation were examined.Treatment with NaCl (at 0-200 mmol L 1 levels) significantly increased Na+ secretion,whereas KCl treatment (at 0-200 mmol L 1 levels) significantly increased K+ secretion.The ratio of secretion to accumulation of Na+ was higher than that of K+.The changes in Na+ and K+ secretion differed after adding different ions into the single-salt solutions.Addition of NaCl to the KCl solution (at 100 mmol L 1 level,respectively) led to a significant decrease in K+ secretion rate,whereas addition of KCl to the NaCl solution (at 100 mmol L 1 level,respectively) had little impact on the Na+ secretion rate.These results indicated that Na+ secretion in Tamarix was highly selective.In addition,Na+ secretion was significantly inhibited by orthovanadate,ouabain,TEA and verapamil,and K+ secretion was significantly inhibited by ouabain,TEA and verapamil.The different impacts of orthovanadate on Na+ and K+ secretion might be the primary cause for the different Na+ and K+ secretion abilities of multicellular salt glands in Tamarix.
基金supported by the National Natural Science Foundation of China(31225015)National Basic Research Program of China(2012CB910900)to Qi YiJun
文摘microRNAs(miRNAs)have emerged as key components in the eukaryotic gene regulatory network.We and others have previously identified many miRNAs in a unicellular green alga,Chlamydomonas reinhardtii.To investigate whether miRNA-mediated gene regulation is a general mechanism in green algae and how miRNAs have been evolved in the green algal lineage,we examined small RNAs in Volvox carteri,a multicellular species in the same family with Chlamydomonas reinhardtii.We identified 174 miRNAs in Volvox,with many of them being highly enriched in gonidia or somatic cells.The targets of the miRNAs were predicted and many of them were subjected to miRNA-mediated cleavage in vivo,suggesting that miRNAs play regulatory roles in the biology of green algae.Our catalog of miRNAs and their targets provides a resource for further studies on the evolution,biological functions,and genomic properties of miRNAs in green algae.
文摘背景:组织工程骨构建体的血管化性能不足是限制骨组织工程用于修复大尺寸骨缺损临床应用的主要挑战。目的:对近年来利用骨形成细胞和血管生成细胞构建组织工程构建体(基于支架或无支架)在骨修复中的应用进行了概述,以期实现组织工程骨可持续的血管生成及生成功能完善的血管,从而提高骨组织工程在大尺寸骨缺损修复应用中的细胞存活率、并为促进骨的形成和重塑提供参考。方法:应用计算机对中国知网、PubMed及Web of Science数据库2000-2021年发表的文献进行了检索,中文检索词为“骨组织工程、成骨成血管、多细胞”,英文检索词为“Bone Tissue Engineering,Osteogenesis and angiogenesis,Multicellular”,根据纳入和排除标准,最终纳入63篇文献进行结果分析。结果与结论:①目前最常用的骨形成细胞主要有间充质干细胞、脂肪干细胞和成骨细胞,常用的血管生成细胞有人脐静脉内皮细胞和内皮祖细胞。②支架内包封细胞在实现各类细胞的精准定位方面优于在支架上接种细胞。③将两种单一细胞膜片相叠加或者共培养单层细胞膜片相叠加的方法,可以调控各类细胞的位置,从而构建血管化网络。④目前,基于支架的组织工程技术还需克服支架降解速率与组织再生速率的不匹配性、细胞与生物材料相互作用不可控等问题,而基于无支架细胞膜片的组织工程还需要克服力学强度低的难题。⑤未来研究需构建具有临床所需大小的功能性3D血管化组织工程骨,还需关注包括细胞培养和生物学作用机制;结合组织工程、细胞工程和基因工程构建组织工程骨,有望实现刺激早期血管生成、保持血液循环,防止构建体内部的细胞死亡,并起到加速构建体修复临床大体积骨缺损的作用。
基金Supported by the National Natural Science Foundation of China(Nos. 40906069,40776094)Shangdong 908 Project (No. SD-908-02-08)+1 种基金the Haiwaijiechuxuezhe-Fund of Chinese Academy of Sciences (No.2006-1-15)K. C. WONG Education Foundation
文摘Multicellular magnetotactic prokaryotes （MMPs） are a group of aggregates composed of 7-45 gram-negative cells synthesizing intracellular magnetic crystals. Although they are thought to be globally distributed, MMPs have been observed only in marine environments in America and Europe. Most MMPs share a rosette-like morphology and biomineralize iron sulfide crystals. In the present study, abundant MMPs were observed, with a density of 26 ind./cm^3, in the sediments of a coastal lagoon, Lake Yuehu, in the Yellow Sea. Optical microscopy showed that all of them were rosette shaped with a diameter of 5.5±0.8 μm. Transmission electron microscopy revealed that these MMPs were composed of 10- 16 ovoid cells and flagellated peritrichously. High-resolution transmission electron microscopy and energy dispersive X-ray analysis indicated that they biomineralized bullet-shaped magnetite crystals in highly organized parallel chains within which the magnetosomes were oriented in the same direction. This is the first report of MMPs from Asia and demonstrates the ubiquitous distribution of MMPs.
基金supported by the National Health and Medical Research Council of Australia fellowship(ID1043026 to Xiaojun Du)
文摘Following myocardial infarction(MI), cardiomyocytes and infarct size are the focus of our attention when evaluating the extent of cardiac injury, efficacy of therapies or success in repairing the damaged heart by stem cell therapy. Numerous interventions have been shown by pre-clinical studies to be effective in limiting infarct size, and yet clinical trials designed accordingly have yielded disappointing outcomes. The ultimate goal of cardiac protection is to limit the adverse cardiac remodeling. Accumulating studies have revealed that post-infarct remodeling can be attenuated without infarct size limitation. To reconcile this, one needs to appreciate the significance of various cellular and acellular myocardial components that, like cardiomyocytes, undergo significant damage and dysfunction, which impact the ultimate cardiac injury and remodelling. Microvascular injury following ischemia-reperfusion may influence infarct size and promote inflammation. Myocardial injury evokes innate immunity with massive inflammatory infiltration that, although essential for the healing process, exacerbates myocardial injury and damage to extracellular matrix leading to dilative remodeling. It is also important to consider the multiple non-cardiomyocyte components in evaluating therapeutic efficacy. Current research indicates the pivotal role of these components in achieving cardiac regeneration by cell therapy. This review summarizes findings in this field, highlights a broad consideration of therapeutic targets,and recommends cardiac remodeling as the ultimate target.
基金supported by the National Natural Science Foundation of China (91640202, 91335104)the grants from Guangdong Province (2016A030308015) and Guangzhou (201707020018, 201710010029)
文摘Recent studies have indicated that a special type of small noncoding RNAs, phased small-interfering RNAs(phasiRNAs) play crucial roles in many cellular processes of plant development. PhasiRNAs are generated from long RNA precursors at intervals of 21 or 24 nt in plants, and they are produced from both protein-coding gene and long noncoding RNA genes. Different from those in eudicots, grass phasiRNAs include a special class of small RNAs that are specifically expressed in reproductive organs.These grass phasiRNAs are associated with gametogenesis, especially with anther development and male fertility. In this review,we summarized current knowledge on these small noncoding RNAs in male germ cells and their possible biological functions and mechanisms in grass species.
