14 results on '"Niu, Wanbao"'
Search Results
2. Determination and Prediction of Time-Varying Parameters of Mooney–Rivlin Model of Rubber Material Used in Natural Rubber Bearing under Alternating of Aging and Seawater Erosion.
- Author
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Niu, Wanbao, Li, Yanmin, Ma, Yuhong, and Zhao, Guifeng
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RUBBER bearings , *RUBBER , *EROSION , *SEAWATER - Abstract
In this paper, we examined the parameters of the Mooney–Rivlin model based on the effects of alternative aging and sea corrosion tests for natural rubber bearings and rubber materials in seawater. The model parameters for rubber material used in natural rubber bearings were determined using the least-squares method. Meanwhile, the time-varying law formula of the Mooney–Rivlin model parameters of rubber were fitted, and the fitting and calculated values were compared. Both fitting values and calculated values coincide with each other well. Then, the rubber material parameters were predicted based on the calculated results and combined with nonlinear auto-regressive (NAR). The predicted values were compared with both the fitting and calculated values. The average deviations between predicted and fitting values for C10 and C01 were 2.6% and 5.1%, respectively, and average deviations between predicted and calculated values for C10 and C01 were 5.2% and 4.1%. Compared results show that the predicted values are in good agreement with both the fitting and calculated values; meanwhile, the proposed time-varying law formula of the Mooney–Rivlin model parameters of rubber material have been well verified. [ABSTRACT FROM AUTHOR]
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- 2023
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3. CDC42 controls the activation of primordial follicles by regulating PI3K signaling in mouse oocytes
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Yan, Hao, Zhang, Jiawei, Wen, Jia, Wang, Yibo, Niu, Wanbao, Teng, Zhen, Zhao, Tongtong, Dai, Yanli, Zhang, Yan, Wang, Chao, Qin, Yingying, Xia, Guoliang, and Zhang, Hua
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- 2018
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4. S100A8, An Oocyte-Specific Chemokine, Directs the Migration of Ovarian Somatic Cells During Mouse Primordial Follicle Assembly.
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Teng, Zhen, Wang, Chao, Wang, Yijing, Huang, Kun, Xiang, Xi, Niu, Wanbao, Feng, Lizhao, Zhao, Lihua, Yan, Hao, Zhang, Hua, and Xia, Guoliang
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OVUM ,BIOLOGICAL assay ,CHEMOKINES ,SMALL interfering RNA ,CELL migration ,SOMATIC cells ,CHEMOTAXIS - Abstract
In the mammalian ovaries, the primordial follicle pool determines the reproductive capability over the lifetime of a female. The primordial follicle is composed of two cell members, namely the oocyte and the pre-granulosa cells that encircle the oocyte. However, it is unclear what factors are involved in the reorganization of the two distinct cells into one functional unit. This study was performed to address this issue. Firstly, in an in vitro reconstruction system, dispersed ovarian cells from murine fetal ovaries at 19.0 days post coitum (dpc) reassembled into follicle-like structures, independent of the physical distance between the cells, implying that either oocytes or ovarian somatic cells (OSCs) were motile. We then carried out a series of transwell assay experiments, and determined that it was in fact 19.0 dpc OSCs (as opposed to oocytes), which exhibited a significant chemotactic response to both fetal bovine serum and oocytes themselves. We observed that S100A8, a multi-functional chemokine, may participate in the process as it is mainly expressed in oocytes within the cysts/plasmodia. S100A8 significantly promoted the number of migrating OSCs by 2.5 times in vitro, of which 66.9% were FOXL2 protein-positive cells, implying that the majority of motile OSCs were pre-granulosa cells. In addition, an S100A8-specific antibody inhibited the formation of follicle-like reconstruction cell mass in vitro. And, the primordial follicle formation was reduced when S100a8-specific siRNA was applied onto in vitro cultured 17.5 dpc ovary. Therefore, S100A8 could be a chemokine of oocyte origin, which attracts OSCs to form the primordial follicles. J. Cell. Physiol. 230: 2998-3008, 2015. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]
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- 2015
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5. Mouse oocytes develop in cysts with the help of nurse cells.
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Niu, Wanbao and Spradling, Allan C.
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OOGENESIS , *OVARIAN reserve , *APOPTOSIS , *OVUM , *GERM cells , *NURSES , *NURSING models - Abstract
Mouse germline cysts, on average, develop into six oocytes supported by 24 nurse cells that transfer cytoplasm and organelles to generate a Balbiani body. We showed that between E14.5 and P5, cysts periodically activate some nurse cells to begin cytoplasmic transfer, which causes them to shrink and turnover within 2 days. Nurse cells die by a programmed cell death (PCD) pathway involving acidification, similar to Drosophila nurse cells, and only infrequently by apoptosis. Prior to initiating transfer, nurse cells co-cluster by scRNA-seq with their pro-oocyte sisters, but during their final 2 days, they cluster separately. The genes promoting oocyte development and nurse cell PCD are upregulated, whereas the genes that repress transfer, such as Tex14, and oocyte factors, such as Nobox and Lhx8, are under-expressed. The transferred nurse cell centrosomes build a cytocentrum that establishes a large microtubule aster in the primordial oocyte that organizes the Balbiani body, defining the earliest oocyte polarity. [Display omitted] • A comprehensive model of the nurse cell development in mice is presented • Mouse nurse cells die by a programmed cell death pathway like Drosophila nurse cells • Genetic changes associated with nurse cell activation are identified • Centrosome transfer and consolidation generate a large microtubule aster By providing a detailed investigation of nurse cells involved in mammalian oocyte development, this manuscript identifies evolutionarily conserved mechanisms of oocyte fate determination and development and addressed the question of why so many germ cells are initially made but only a subset eventually become oocytes and make up the ovarian reserve. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Follistatin288 Regulates Germ Cell Cyst Breakdown and Primordial Follicle Assembly in the Mouse Ovary.
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Wang, Zhengpin, Niu, Wanbao, Wang, Yijing, Teng, Zhen, Wen, Jia, Xia, Guoliang, and Wang, Chao
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FOLLISTATIN , *GERM cells , *OVARIAN follicle , *OVARIAN physiology , *LABORATORY mice - Abstract
In mammals, the primordial follicle pool represents the entire reproductive potential of a female. The transforming growth factor-β (TGF-β) family member activin (ACT) contributes to folliculogenesis, although the exact mechanism is not known. The role of FST288, the strongest ACT-neutralizing isoform of follistatin (FST), during cyst breakdown and primordial follicle formation in the fetal mice ovary was assessed using an in vitro culture system. FST was continuously expressed in the oocytes as well as the cuboidal granulosa cells of growing follicles in perinatal mouse ovaries. Treatment with FST288 delayed germ cell nest breakdown, particularly near the periphery of the ovary, and dramatically decreased the percentage of primordial follicles. In addition, there was a dramatic decrease in proliferation of granulosa cells and somatic cell expression of Notch signaling was impaired. In conclusion, FST288 impacts germ cell nest breakdown and primordial follicle assembly by inhibiting somatic cell proliferation. [ABSTRACT FROM AUTHOR]
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- 2015
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7. Effect of Different Culture Systems and 3, 5, 3'-Triiodothyronine/Follicle-Stimulating Hormone on Preantral Follicle Development in Mice.
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Zhang, Cheng, Wang, Xiaoxia, Wang, Zhengpin, Niu, Wanbao, Zhu, Baochang, and Xia, Guoliang
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TRIIODOTHYRONINE ,FOLLICLE-stimulating hormone ,DEVELOPMENTAL biology ,GENITALIA ,CELL physiology ,BIOCHEMISTRY ,GROWTH factors ,ENDOCRINOLOGY of human reproduction ,LABORATORY mice - Abstract
The mechanical method to isolate preantral follicle has been reported for many years. However, the culture systems in vitro are still unstable. The aim of this study was to analyze the effect of the culture system of mice preantral follicles on the follicular development in vitro. The results showed that the 96-well plate system was the most effective method for mice follicle development in vitro (volume change: 51.71%; survival rate: 89%, at day 4). Follicle-stimulating hormone (FSH) and Thyroid hormone (TH) are important for normal follicular development and dysregulation of hormones are related with impaired follicular development. To determine the effect of hormone on preantral follicular development, we cultured follicle with hormones in the 96-well plate culture system and found that FSH significantly increased preantral follicular growth on day 4. The FSH-induced growth action was markedly enhanced by T
3 although T3 was ineffective alone. We also demonstrated by QRT-PCR that T3 significantly enhanced FSH-induced up-regulation of Xiap mRNA level. Meanwhile, Bad, cell death inducer, was markedly down-regulated by the combination of hormones. Moreover, QRT-PCR results were also consistent with protein regulation which detected by Western Blotting analysis. Taken together, the findings of the present study demonstrate that 96-well plate system is an effective method for preantral follicle development in vitro. Moreover, these results provide insights on the role of thyroid hormone in increasing FSH-induced preantral follicular development, which mediated by up-regulating Xiap and down-regulating Bad. [ABSTRACT FROM AUTHOR]- Published
- 2013
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8. Rac1 modulates the formation of primordial follicles by facilitating STAT3-directed Jagged1, GDF9 and BMP15 transcription in mice.
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Zhao, Lihua, Du, Xinhua, Huang, Kun, Zhang, Tuo, Teng, Zhen, Niu, Wanbao, Wang, Chao, and Xia, Guoliang
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- 2016
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9. Conservation of oocyte development in germline cysts from Drosophila to mouse.
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Spradling AC, Niu W, Yin Q, Pathak M, and Maurya B
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- Female, Pregnancy, Mice, Animals, Germ Cells, Oocytes, Gametogenesis, Drosophila, Oogenesis
- Abstract
Recent studies show that pre-follicular mouse oogenesis takes place in germline cysts, highly conserved groups of oogonial cells connected by intercellular bridges that develop as nurse cells as well as an oocyte. Long studied in Drosophila and insect gametogenesis, female germline cysts acquire cytoskeletal polarity and traffic centrosomes and organelles between nurse cells and the oocyte to form the Balbiani body, a conserved marker of polarity. Mouse oocyte development and nurse cell dumping are supported by dynamic, cell-specific programs of germline gene expression. High levels of perinatal germ cell death in this species primarily result from programmed nurse cell turnover after transfer rather than defective oocyte production. The striking evolutionary conservation of early oogenesis mechanisms between distant animal groups strongly suggests that gametogenesis and early embryonic development in vertebrates and invertebrates share even more in common than currently believed., Competing Interests: AS, WN, QY, MP, BM No competing interests declared, (© 2022, Spradling et al.)
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- 2022
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10. ADAM10-Notch signaling governs the recruitment of ovarian pregranulosa cells and controls folliculogenesis in mice.
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Feng L, Wang Y, Cai H, Sun G, Niu W, Xin Q, Tang X, Zhang J, Wang C, Zhang H, and Xia G
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- Animals, Animals, Newborn, Cell Differentiation, Cell Proliferation, Female, Forkhead Box Protein L2, Forkhead Transcription Factors metabolism, Germ Cells metabolism, Granulosa Cells cytology, Mice, Receptors, G-Protein-Coupled metabolism, Stem Cells cytology, Stem Cells metabolism, ADAM10 Protein metabolism, Granulosa Cells metabolism, Organogenesis, Receptors, Notch metabolism, Signal Transduction
- Abstract
Ovarian follicles are the basic functional units of female reproduction in the mammalian ovary. We show here that the protein a disintegrin and metalloproteinase domain 10 (ADAM10), a cell surface sheddase, plays an indispensable role in controlling primordial follicle formation by regulating the recruitment of follicle supporting cells in mice. We demonstrate that suppressing ADAM10 in vitro or deletion of Adam10 in vivo disrupts germline cyst breakdown and primordial follicle formation. Using a cell lineage tracing approach, we show that ADAM10 governs the recruitment of ovarian follicle cells by regulating the differentiation and proliferation of LGR5-positive follicle supporting progenitor cells. By detecting the development of FOXL2-positive pregranulosa cells, we found that inhibiting ADAM10 reduced the number of FOXL2-positive cells in perinatal ovaries. Furthermore, inhibiting ADAM10 suppressed the activation of Notch signaling, and blocking Notch signaling also disrupted the recruitment of follicle progenitor cells. Taken together, these results show that ADAM10-Notch signaling in ovarian somatic cells governs the primordial follicle formation by controlling the development of ovarian pregranulosa cells. The proper recruitment of ovarian follicle supporting cells is essential for establishment of the ovarian reserve in mice., (© 2016. Published by The Company of Biologists Ltd.)
- Published
- 2016
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11. JNK signaling regulates E-cadherin junctions in germline cysts and determines primordial follicle formation in mice.
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Niu W, Wang Y, Wang Z, Xin Q, Wang Y, Feng L, Zhao L, Wen J, Zhang H, Wang C, and Xia G
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- Animals, Female, Gene Knockdown Techniques, JNK Mitogen-Activated Protein Kinases antagonists & inhibitors, Mice, Proteolysis, Proto-Oncogene Proteins c-mdm2 metabolism, Wnt4 Protein metabolism, Cadherins metabolism, Germ Cells metabolism, JNK Mitogen-Activated Protein Kinases metabolism, MAP Kinase Signaling System, Organogenesis, Ovarian Follicle metabolism
- Abstract
Physiologically, the size of the primordial follicle pool determines the reproductive lifespan of female mammals, while its establishment largely depends on a process of germline cyst breakdown during the perinatal period. The mechanisms regulating this process are poorly understood. Here we demonstrate that c-Jun amino-terminal kinase (JNK) signaling is crucial for germline cyst breakdown and primordial follicle formation. JNK was specifically localized in oocytes and its activity increased as germline cyst breakdown progressed. Importantly, disruption of JNK signaling with a specific inhibitor (SP600125) or knockdown technology (Lenti-JNK-shRNAs) resulted in significantly suppressed cyst breakdown and primordial follicle formation in cultured mouse ovaries. Our results show that E-cadherin is intensely expressed in germline cysts, and that its decline is necessary for oocyte release from the cyst. However, inhibition of JNK signaling leads to aberrantly enhanced localization of E-cadherin at oocyte-oocyte contact sites. WNT4 expression is upregulated after SP600125 treatment. Additionally, similar to the effect of SP600125 treatment, WNT4 overexpression delays cyst breakdown and is accompanied by abnormal E-cadherin expression patterns. In conclusion, our results suggest that JNK signaling, which is inversely correlated with WNT4, plays an important role in perinatal germline cyst breakdown and primordial follicle formation by regulating E-cadherin junctions between oocytes in mouse ovaries., (© 2016. Published by The Company of Biologists Ltd.)
- Published
- 2016
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12. Gap junctions are essential for murine primordial follicle assembly immediately before birth.
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Teng Z, Wang C, Wang Y, Huang K, Xiang X, Niu W, Feng L, Zhao L, Yan H, and Zhang H
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- Animals, Animals, Newborn, Connexin 43 antagonists & inhibitors, Connexin 43 genetics, Connexins antagonists & inhibitors, Connexins genetics, Female, Gap Junctions drug effects, Gap Junctions genetics, Gene Knockdown Techniques, Granulosa Cells cytology, Granulosa Cells drug effects, Male, Mice, Mice, Transgenic, Oocytes cytology, Oocytes drug effects, Ovarian Follicle cytology, Ovarian Follicle drug effects, Pregnancy, RNA, Small Interfering pharmacology, Gap Junction alpha-4 Protein, Cell Communication drug effects, Cell Communication genetics, Gap Junctions physiology, Granulosa Cells physiology, Oocytes physiology, Ovarian Follicle physiology, Parturition physiology
- Abstract
The reserve of primordial follicles determines the reproductive ability of the female mammal over its reproductive life. The primordial follicle is composed of two types of cells: oocytes and surrounding pre-granulosa cells. However, the underlying mechanism regulating primordial follicle assembly is largely undefined. In this study, we found that gap junction communication (GJC) established between the ovarian cells in the perinatal mouse ovary may be involved in the process. First, gap junction structures between the oocyte and surrounding pre-granulosa cells appear at about 19.0 dpc (days post coitum). As many as 12 gap junction-related genes are upregulated at birth, implying that a complex communication may exist between ovarian cells, because specifically silencing the genes of individual gap junction proteins, such as Gja1, Gja4 or both, has no influence on primordial follicle assembly. On the other hand, non-specific blockers of GJC, such as carbenoxolone (CBX) and 18α-glycyrrhetinic acid (AGA), significantly inhibit mouse primordial follicle assembly. We proved that the temporal window for establishment of GJC in the fetal ovary is from 19.5 dpc to 1 dpp (days postpartum). In addition, the expression of ovarian somatic cell (OSC)-specific genes, such as Notch2, Foxl2 and Irx3, was negatively affected by GJC blockers, whereas oocyte-related genes, such as Ybx2, Nobox and Sohlh1, were hardly affected, implying that the establishment of GJC during this period may be more important to OSCs than to oocytes. In summary, our results indicated that GJC involves in the mouse primordial follicle assembly process at a specific temporal window that needs Notch signaling cross-talking., (© 2016 Society for Reproduction and Fertility.)
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- 2016
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13. Cyclic AMP in oocytes controls meiotic prophase I and primordial folliculogenesis in the perinatal mouse ovary.
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Wang Y, Teng Z, Li G, Mu X, Wang Z, Feng L, Niu W, Huang K, Xiang X, Wang C, Zhang H, and Xia G
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- Analysis of Variance, Animals, Female, Fluorescent Antibody Technique, Immunoblotting, Mice, Microdissection, RNA Interference, Radioimmunoassay, Cyclic AMP metabolism, Meiotic Prophase I physiology, Oocytes metabolism, Organogenesis physiology, Ovarian Follicle embryology
- Abstract
In mammalian ovaries, a fixed population of primordial follicles forms during the perinatal stage and the oocytes contained within are arrested at the dictyate stage of meiotic prophase I. In the current study, we provide evidence that the level of cyclic AMP (cAMP) in oocytes regulates oocyte meiotic prophase I and primordial folliculogenesis in the perinatal mouse ovary. Our results show that the early meiotic development of oocytes is closely correlated with increased levels of intra-oocyte cAMP. Inhibiting cAMP synthesis in fetal ovaries delayed oocyte meiotic progression and inhibited the disassembly and degradation of synaptonemal complex protein 1. In addition, inhibiting cAMP synthesis in in vitro cultured fetal ovaries prevented primordial follicle formation. Finally, using an in situ oocyte chromosome analysis approach, we found that the dictyate arrest of oocytes is essential for primordial follicle formation under physiological conditions. Taken together, these results suggest a role for cAMP in early meiotic development and primordial follicle formation in the mouse ovary., (© 2015. Published by The Company of Biologists Ltd.)
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- 2015
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14. The effect of gonadotropin on glucose transport and apoptosis in rat ovary.
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Zhang C, Niu W, Wang Z, Wang X, and Xia G
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- Animals, Apoptosis physiology, Biological Transport, Active drug effects, Biological Transport, Active physiology, Female, Protein Isoforms metabolism, Rats, Rats, Sprague-Dawley, Apoptosis drug effects, Glucose metabolism, Glucose Transporter Type 1 metabolism, Gonadotropins pharmacology, Ovarian Follicle metabolism
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Although the effects of Gonadotropin on ovarian physiology have been known for many decades, its action on glucose uptake in the rat ovary remained poorly understood. Evidence also suggests that glucose uptake is mediated by a number of glucose transporter proteins (Glut). Therefore, we examined the rat ovary for the presence of Glut1-4 and blood glucose level after eCG (equine chorionic gonadotropin) and anti-eCG antiserum treatment. All of the glucose transports were present in the ovarian oocyte, granulosa cells and theca cells in different stage follicles. The expression of Glut in ovary was up-regulated by eCG, however, anti-eCG antiserum reversed eCG action. Western blot analysis also demonstrated the content of Glut1 was higher in eCG treatment group compared with anti-eCG antiserum and control group. The same tendency was shown in other glut isoforms. Moreover, there were no significant difference between the anti-eCG antiserum and control group. In additional, the level of serum glucose in eCG treatment group was significantly higher than others, which is similar with glut expression pattern. High glucose level in blood is correlated with increased expression of glucose transporter proteins in rat ovary. Meanwhile, anti-eCG antiserum increased granulosa cell apoptosis in antral follicle compared with those in eCG group. Our observations provide potential explanation for the effects of Glut on follicular development in rat ovary and a role for eCG in the regulation of ovarian glucose uptake.
- Published
- 2012
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