Objective： To evaluate the effect of Heyan Kuntai Capsule （和颜坤泰胶囊, HYKT） on the ovarian function of aged mice and expressions of cohesion complexes in oocytes. Methods： Twenty-five 9-month-old female C57BL/6...Objective： To evaluate the effect of Heyan Kuntai Capsule （和颜坤泰胶囊, HYKT） on the ovarian function of aged mice and expressions of cohesion complexes in oocytes. Methods： Twenty-five 9-month-old female C57BL/6J mice were randomly divided into 5 groups by block randomization method （n=5 per group）, including the control group （saline）, 17β-estradiol group [E2, 100 μg/（kg·d）], and low-, medium-, and high- dose of HYKT groups [0.3, 0.9, 2.7 g/（kg·d）, respectively]. All mice were treated by intragastric administration for 4 weeks. Hematoxylin and eosin staining and anti-VASA staining were used to detect the amounts of follicles. The apoptosis of follicles was measured by anti-gamma H2A histone family member X （γ, H2AX） staining and TdT-mediated dUTP Nick-End Labeling （TUNEL） assay. The density of cohesin subunits, REC8 meiotic recombination protein （REC8）, structural maintenance of chromosome （SMC） 1 β and SMC3 in oocytes were evaluated by immunofluorescent staining. Results： After administration of E2 and high-dose of HYKT, the total number of follicles as well as the number of primordial and primary follicles were significantly increased （P〈0.05）. Anti-γ/H2AX staining and TUNEL assay demonstrated that high-dose of HYKT and E2 partly suppressed the apoptosis of follicles （P〈0.05）. Furthermore, it showed an increased trend in the levels of REC8 and SMC1 β, after administration with E2 and HYKT, and no obvious change in the level of SMC3. Conclusion： HYKT could enhance the number of follicles, suppress apoptosis of oocytes and have a trend to elevate the meiotic-specific cohesin subunits （REC8 and SMC1 β） in oocytes of aged mice, indicating a beneficial effect on the ovarian function in terms of the quantity and quality of follicles.展开更多
One of the main causes of pregnancy failure and fetus abortion is oocyte aneuploidy,which is increased with maternal aging.Numerous possible causes of oocyte aneuploidy in aged women have been proposed,including cross...One of the main causes of pregnancy failure and fetus abortion is oocyte aneuploidy,which is increased with maternal aging.Numerous possible causes of oocyte aneuploidy in aged women have been proposed,including cross-over formation defect,cohesin loss,spindle deformation,spindle assembly checkpoint malfunction,microtubule-kinetochore attachment failure,kinetochore mis-orientation,mitochondria dysfunction-induced increases in reactive oxygen species,protein over-acetylation,and DNA damage.However,it still needs to be answered if these aneuploidization factors have inherent relations,and how to prevent chromosome aneuploidy in aged oocytes.Epidemiologically,oocyte aneuploidy has been found to be weakly associated with higher homocysteine concentrations,obesity,ionizing radiation and even seasonality.In this review,we summarize the research progress and present an integrated view of oocyte aneuploidization.展开更多
Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chro...Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.展开更多
RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis,but the targets and molecular functions of RBM46 remain unknown.Here,we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of...RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis,but the targets and molecular functions of RBM46 remain unknown.Here,we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation.Using a recently reported,high-resolution technique known as LACE-seq and working with low-input cells,we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes.We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3'UTRs regions.In Rbm46 knockout mice,the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation,resulting in the failed assembly of axial elements,synapsis disruption,and meiotic arrest.Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.展开更多
In a series of publications a special, tetraploid diplochromosomal division system to only two types of progeny cells (4n/4C/G1 and 2n/4C para-diploid) has been suggested to initiate preneoplasia that can lead to a ca...In a series of publications a special, tetraploid diplochromosomal division system to only two types of progeny cells (4n/4C/G1 and 2n/4C para-diploid) has been suggested to initiate preneoplasia that can lead to a cancerous pathway. Colorectal and other preneoplasia are known with the pathogenic, histological phases of hyperplasia to arrested adenoma/nevi that can give rise to dysplasia with high risk for cancer development. The present theme is to find solutions to tumorigenic unsolved, biological problems (queries), explainable from the tetraploid 4n-system, which would support its operation in the cancerous pathway. Presently admitted, the mutational sequencing of the cancer genome (cancer chemistry) cannot discover so-called “dark matter”, which herein is considered to be the queries. The solutions from the 4n-system were largely supported by mutated APC-induced same type of tetraploidy from the mitotic slippage process. But importantly, these behaviors and consequences could be linked to the beginning of hyperplastic lesions and their development to the arrest-phase of preneoplasia (polyps/nevi). Function of HFSMs is mostly unknown, but for Barrett’s esophagus, HFSMs (p53, p16ink4a) caused inactivation of the Rb gene, leading to dysplasia with 4n, aneuploid, abnormal cell cycles. In vitro models of the 4n-system from normal human cells recapitulated preneoplasia-like histopathological changes. It was speculated that the “cancer-crucial” step to dysplasia could be therapy-vulnerable to CRISPR-caspase editing, and perhaps antibody treatment. Additionally, the 4n-system with spontaneous cell-behaviors together with preneoplasia molecular data promises construction of a more truthful cancer-paradigm than from sequencing data alone.展开更多
Production of economically viable bioethanol is potentially an environmentally and financially worthwhile endeavor.One major source for fermentable sugars is lignocellulose.However,lignocellulosic biomass is difficult...Production of economically viable bioethanol is potentially an environmentally and financially worthwhile endeavor.One major source for fermentable sugars is lignocellulose.However,lignocellulosic biomass is difficult to degrade,owing to its inherent structural recalcitrance.Cellulosomes are complexes of cellulases and associated polysaccharide-degrading enzymes bound to a protein scaffold that can efficiently degrade lignocellulose.Integration of the enzyme subunits into the complex depends on intermodular cohesin-dockerin interactions,which are robust but nonetheless non-covalent.The modular architecture of these complexes can be used to assemble artificial designer cellulosomes for advanced nanotechnological applications.Pretreatments that promote lignocellulose degradation involve high temperatures and acidic or alkaline conditions that could dismember designer cellulosomes,thus requiring separation of reaction steps,thereby increasing overall process cost.To overcome these challenges,we developed a means of covalently locking cohesin-dockerin interactions by integrating the chemistry of SpyCatcher-SpyTag approach to target and secure the interaction.The resultant cohesin-conjugated dockerin complex was resistant to high temperatures,SDS,and urea while high affinity and specificity of the interacting modular components were maintained.Using this approach,a covalently locked,bivalent designer cellulosome complex was produced and demonstrated to be enzymatically active on cellulosic substrates.The combination of affinity systems with SpyCatcher-SpyTag chemistry may prove of general use for improving other types of protein ligation systems and creating unconventional,biologically active,covalently locked,affinity-based molecular architectures.展开更多
Meiosis is a specialized eukaryotic cell division, in which diploid cells undergo a single round of DNA replication and two rounds of nuclear division to produce haploid gametes. In most eukaryotes, the core events of...Meiosis is a specialized eukaryotic cell division, in which diploid cells undergo a single round of DNA replication and two rounds of nuclear division to produce haploid gametes. In most eukaryotes, the core events of meiotic prophase I are chromosomal pairing,synapsis and recombination. To ensure accurate chromosomal segregation, homologs have to identify and align along each other at the onset of meiosis. Although much progress has been made in elucidating meiotic processes, information on the mechanisms underlying chromosome pairing is limited in contrast to the meiotic recombination and synapsis events. Recent research in many organisms indicated that centromere interactions during early meiotic prophase facilitate homologous chromosome pairing, and functional centromere is a prerequisite for centromere pairing such as in maize. Here, we summarize the recent achievements of chromosome pairing research on plants and other organisms, and outline centromere interactions, nuclear chromosome orientation,and meiotic cohesin, as main determinants of chromosome pairing in early meiotic prophase.展开更多
Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of th...Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.展开更多
a-kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes encoding four a-kleisins. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCCI orth...a-kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes encoding four a-kleisins. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCCI orthologs and function in mitosis. SYN3 is enriched in the nucleolus of meiotic and mitotic cells and is essential for megagametogenesis. It was recently shown that expression of SYN3-RNAi constructs in buds cause changes in meiotic gene expression that result in meiotic alterations. In this report we show that expression of SYN3 from the 35S promoter with either a c-terminal Myc or FAST tag causes a reduction in SYN1 mRNA levels that results in al- terations in sister chromatid cohesion, homologous chromosome synapsis female meiosis. and synaptonemal complex formation during both male and展开更多
基金Supported by the National Natural Science Foundation of China(No.31571196,81401171,30801502)the 2015 Program to Guide Medicine of the Shanghai Municipal Science and Technology Commission(No.15401932200)+4 种基金the FY2008 JSPS Postdoctoral Fellowship for Foreign Researchers(No.P08471)the Shanghai Pujiang Program(No.11PJ1401900)the Development Project of Shanghai Peak Disciplines-Integrated Chinese and Western Medicinethe Program for Outstanding Medical Academic LeaderDevelopment Project of Shanghai Peak Disciplines-Integrated Chinese and Western Medicine(No.20150407)
文摘Objective： To evaluate the effect of Heyan Kuntai Capsule （和颜坤泰胶囊, HYKT） on the ovarian function of aged mice and expressions of cohesion complexes in oocytes. Methods： Twenty-five 9-month-old female C57BL/6J mice were randomly divided into 5 groups by block randomization method （n=5 per group）, including the control group （saline）, 17β-estradiol group [E2, 100 μg/（kg·d）], and low-, medium-, and high- dose of HYKT groups [0.3, 0.9, 2.7 g/（kg·d）, respectively]. All mice were treated by intragastric administration for 4 weeks. Hematoxylin and eosin staining and anti-VASA staining were used to detect the amounts of follicles. The apoptosis of follicles was measured by anti-gamma H2A histone family member X （γ, H2AX） staining and TdT-mediated dUTP Nick-End Labeling （TUNEL） assay. The density of cohesin subunits, REC8 meiotic recombination protein （REC8）, structural maintenance of chromosome （SMC） 1 β and SMC3 in oocytes were evaluated by immunofluorescent staining. Results： After administration of E2 and high-dose of HYKT, the total number of follicles as well as the number of primordial and primary follicles were significantly increased （P〈0.05）. Anti-γ/H2AX staining and TUNEL assay demonstrated that high-dose of HYKT and E2 partly suppressed the apoptosis of follicles （P〈0.05）. Furthermore, it showed an increased trend in the levels of REC8 and SMC1 β, after administration with E2 and HYKT, and no obvious change in the level of SMC3. Conclusion： HYKT could enhance the number of follicles, suppress apoptosis of oocytes and have a trend to elevate the meiotic-specific cohesin subunits （REC8 and SMC1 β） in oocytes of aged mice, indicating a beneficial effect on the ovarian function in terms of the quantity and quality of follicles.
基金supported by the National Natural Science Foundation of China(31801245,81671425 and 81971357)Key Research&Development Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2019GZR110104001)
文摘One of the main causes of pregnancy failure and fetus abortion is oocyte aneuploidy,which is increased with maternal aging.Numerous possible causes of oocyte aneuploidy in aged women have been proposed,including cross-over formation defect,cohesin loss,spindle deformation,spindle assembly checkpoint malfunction,microtubule-kinetochore attachment failure,kinetochore mis-orientation,mitochondria dysfunction-induced increases in reactive oxygen species,protein over-acetylation,and DNA damage.However,it still needs to be answered if these aneuploidization factors have inherent relations,and how to prevent chromosome aneuploidy in aged oocytes.Epidemiologically,oocyte aneuploidy has been found to be weakly associated with higher homocysteine concentrations,obesity,ionizing radiation and even seasonality.In this review,we summarize the research progress and present an integrated view of oocyte aneuploidization.
基金supported by the Welch Foundation(I-1441 to H.Y.)the Clayton Foundation,and Cancer Prevention and Research Institute of Texas(RP110465-P3 and RP120717-P2 to H.Y.)
文摘Orderly execution of two critical events during the cell cycle––DNA replication and chromosome segregation––ensures the stable transmission of genetic materials. The cohesin complex physically connects sister chromatids during DNA replication in a process termed sister chromatid cohesion. Timely establishment and dissolution of sister chromatid cohesion is a prerequisite for accurate chromosome segregation, and is tight regulated by the cell cycle machinery and cohesin-associated proteins. In this review, we discuss recent progress in the molecular understanding of sister chromatid cohesion during the mitotic cell cycle.
基金supported by grants from the National Key R&D Program of China(2021YFC2700200)Academic Promotion Programme of Shandong First Medical University(2019U001)+5 种基金General Research Fund from Research Grants Council of Hong Kong(14103418)Basic Science Center Program of NFSC(31988101)the Shandong Provincial Key Research and Development Program(2020ZLYS02)a fund from A-Smart Group to support CUHKSDU Joint Laboratory on Reproductive Genetics of CUHK,Major Innovation Projects in Shandong Province(2021ZDSYS16)the Science Foundation for Distinguished Yong Scholars of Shandong(ZR2021JQ27)Taishan Scholars Program for Young Experts of Shandong Province(tsqn202103192).
文摘RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis,but the targets and molecular functions of RBM46 remain unknown.Here,we demonstrate that RBM46 binds at specific motifs in the 3'UTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation.Using a recently reported,high-resolution technique known as LACE-seq and working with low-input cells,we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes.We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3'UTRs regions.In Rbm46 knockout mice,the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation,resulting in the failed assembly of axial elements,synapsis disruption,and meiotic arrest.Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.
文摘In a series of publications a special, tetraploid diplochromosomal division system to only two types of progeny cells (4n/4C/G1 and 2n/4C para-diploid) has been suggested to initiate preneoplasia that can lead to a cancerous pathway. Colorectal and other preneoplasia are known with the pathogenic, histological phases of hyperplasia to arrested adenoma/nevi that can give rise to dysplasia with high risk for cancer development. The present theme is to find solutions to tumorigenic unsolved, biological problems (queries), explainable from the tetraploid 4n-system, which would support its operation in the cancerous pathway. Presently admitted, the mutational sequencing of the cancer genome (cancer chemistry) cannot discover so-called “dark matter”, which herein is considered to be the queries. The solutions from the 4n-system were largely supported by mutated APC-induced same type of tetraploidy from the mitotic slippage process. But importantly, these behaviors and consequences could be linked to the beginning of hyperplastic lesions and their development to the arrest-phase of preneoplasia (polyps/nevi). Function of HFSMs is mostly unknown, but for Barrett’s esophagus, HFSMs (p53, p16ink4a) caused inactivation of the Rb gene, leading to dysplasia with 4n, aneuploid, abnormal cell cycles. In vitro models of the 4n-system from normal human cells recapitulated preneoplasia-like histopathological changes. It was speculated that the “cancer-crucial” step to dysplasia could be therapy-vulnerable to CRISPR-caspase editing, and perhaps antibody treatment. Additionally, the 4n-system with spontaneous cell-behaviors together with preneoplasia molecular data promises construction of a more truthful cancer-paradigm than from sequencing data alone.
文摘Production of economically viable bioethanol is potentially an environmentally and financially worthwhile endeavor.One major source for fermentable sugars is lignocellulose.However,lignocellulosic biomass is difficult to degrade,owing to its inherent structural recalcitrance.Cellulosomes are complexes of cellulases and associated polysaccharide-degrading enzymes bound to a protein scaffold that can efficiently degrade lignocellulose.Integration of the enzyme subunits into the complex depends on intermodular cohesin-dockerin interactions,which are robust but nonetheless non-covalent.The modular architecture of these complexes can be used to assemble artificial designer cellulosomes for advanced nanotechnological applications.Pretreatments that promote lignocellulose degradation involve high temperatures and acidic or alkaline conditions that could dismember designer cellulosomes,thus requiring separation of reaction steps,thereby increasing overall process cost.To overcome these challenges,we developed a means of covalently locking cohesin-dockerin interactions by integrating the chemistry of SpyCatcher-SpyTag approach to target and secure the interaction.The resultant cohesin-conjugated dockerin complex was resistant to high temperatures,SDS,and urea while high affinity and specificity of the interacting modular components were maintained.Using this approach,a covalently locked,bivalent designer cellulosome complex was produced and demonstrated to be enzymatically active on cellulosic substrates.The combination of affinity systems with SpyCatcher-SpyTag chemistry may prove of general use for improving other types of protein ligation systems and creating unconventional,biologically active,covalently locked,affinity-based molecular architectures.
基金supported by the National Natural Science Foundation of China(31600994.31630049)
文摘Meiosis is a specialized eukaryotic cell division, in which diploid cells undergo a single round of DNA replication and two rounds of nuclear division to produce haploid gametes. In most eukaryotes, the core events of meiotic prophase I are chromosomal pairing,synapsis and recombination. To ensure accurate chromosomal segregation, homologs have to identify and align along each other at the onset of meiosis. Although much progress has been made in elucidating meiotic processes, information on the mechanisms underlying chromosome pairing is limited in contrast to the meiotic recombination and synapsis events. Recent research in many organisms indicated that centromere interactions during early meiotic prophase facilitate homologous chromosome pairing, and functional centromere is a prerequisite for centromere pairing such as in maize. Here, we summarize the recent achievements of chromosome pairing research on plants and other organisms, and outline centromere interactions, nuclear chromosome orientation,and meiotic cohesin, as main determinants of chromosome pairing in early meiotic prophase.
文摘Cohesin is an evolutionary conserved complex that controls chromosome segregation during mitosis. Here we show that, in response to DNA damage, Saccharomyces cerevisiae Scc3, one of the major regulatory subunits of the Smc1-Smc3-Scc1 cohesin ring, is phosphorylated on S/T-Q residues. This event depended on the Mec1 checkpoint kinase as well as on cell cycle arrest triggered by the DNA damage checkpoint network. This phosphorylation event also took place during mitosis of an unperturbed cell cycle. The present finding that S. cerevisiae Scc3 is phosphorylated during mitosis represents a potentially important new regulatory step in cohesin’s mitotic functions.
基金supported by a grant from the National Science Foundation of USA(No.MCB0718191)
文摘a-kleisins are core components of meiotic and mitotic cohesin complexes. Arabidopsis contains genes encoding four a-kleisins. SYN1, a REC8 ortholog, is essential for meiosis, while SYN2 and SYN4 appear to be SCCI orthologs and function in mitosis. SYN3 is enriched in the nucleolus of meiotic and mitotic cells and is essential for megagametogenesis. It was recently shown that expression of SYN3-RNAi constructs in buds cause changes in meiotic gene expression that result in meiotic alterations. In this report we show that expression of SYN3 from the 35S promoter with either a c-terminal Myc or FAST tag causes a reduction in SYN1 mRNA levels that results in al- terations in sister chromatid cohesion, homologous chromosome synapsis female meiosis. and synaptonemal complex formation during both male and
