Suppression of SEMA6C promotes preantral follicles atresia with decreased cell junctions in mice ovaries

Mammalian oocytes go through a long and complex developmental process, while acquiring the competencies that are required for fertilization and embryogenesis. Recent studies revealed that the communication between oocytes and granulosa cells (GCs) is a critical process for female follicle development. In the current study, we aimed to study whether and how semaphorin 6C (Sema6c) regulated the cell junctions between oocytes and GCs in mice preantral follicles. The attenuation of SEMA6C expression by siRNA decreased the cell–cell junctions and accelerated follicle atresia in vitro. PI3K-AKT pathway was activated when SEMA6C expression was downregulated. And the LY294002, a PI3K inhibitor, could reverse the effect of low SEMA6C expression on cell junctions in preantral follicles. Our findings revealed that Sema6c was involved in follicle development, and the suppression of SEMA6C led to cell junction defection by activating the PI3K/AKT pathway, which might also provide valuable information for understanding premature ovarian failure and ovarian aging.     

Trends in incidence and survival from anal cancer and incidence of high-grade anal intraepithelial neoplasia in Denmark

ObjectiveThe aim of the current study was to assess temporal trends in incidence of anal squamous cell carcinomas (SCC) and high-grade anal intraepithelial lesions (AIN2/3), and estimate survival from anal cancer and factors related to 5-year mortality in Denmark.MethodsWe analyzed anal SCC and AIN2/3 cases in the period of 1998–2018 from the Danish Cancer Register and the Danish Registry of Pathology, respectively. Overall, period, gender, and histology specific age-standardized incidence rates, average annual percentage change (AAPC), and 5-year relative survival were estimated. Cox proportional hazards models were applied to evaluate the effect on 5-year mortality of period, age, gender, and stage of disease.ResultsAltogether 2580 anal cancers and 871 AIN2/3 were identified. The AIN2/3 incidence increased for women 1998–2007 (AAPC: 3.5% (95% CI −0.7, 8.0)) and then tended to decrease during 2008–2018(AAPC: −5.2% (95% CI −9.6, −0.6)). A similar pattern was observed for men, although at a lower incidence with the decrease starting later (2008–2012) and the trend not reaching statistical significance. The anal SCC incidence increased over the whole study period for both women and men (women AAPC: 4.0% (95% CI 3.2%, 4.9%) and men AAPC: 3.6% (95% CI 2.3%, 4.9%)). The relative survival improved over time (from 61% to 72%). Being older and male was associated with a higher risk of dying within 5 years.ConclusionsThere is a need to focus attention on anal cancer and its precursor lesions, as the cancer incidence continues to increase. Actions could include screening and gender-neutral HPV vaccination.     

Effects of angling on post‐release mortality,gonadal development and somatic condition of Australian bass Macquaria novemaculeata

This study assessed the protracted effects of two angling treatments (mild and harsh) on the post‐release mortality, gonadal development and somatic condition of Australian bass Macquaria novemaculeata in a pond‐based experiment. Angled fish were destructively sampled (along with controls) three times: immediately before, and 1 or 4 weeks after release into cages. Compared with the other groups, harshly angled fish had similar, low immediate and short‐term mortalities (≤5%), but significant delayed mortality (25%) and fed only minimally. None of these fish ejected ingested hooks. Forty‐six per cent of captive fish (across all groups) and 20% of wild fish had non‐ripening gonads (stage I) prior to, or during, the experiment. In females with ripening ovaries (stages II or III), neither angling treatment significantly reduced standardized gonadal mass. The mean per cent of atretic oocytes increased among females in all groups, but was significantly greater in those that were harshly angled. The results demonstrated that the gonadal development of M. novemaculeata could be suppressed or impaired (by angling, handling and confinement), and that further research is warranted. In particular, the timing and severity of angling in relation to the stage of gonadal development could have important implications for the introduction of temporal restrictions to angling.     

Influence of metabolic status on oocyte quality and follicular characteristics at different postpartum periods in primiparous rabbit does

Low reproductive performance of high-yield primiparous animals is closely associated with the metabolic stress caused by a simultaneous gestation and lactation. The aim of this work was (1) to analyze body composition and metabolic environment at three time points along lactation (at parturition time; in the lactation period [Day 11 postpartum]; and in the postweaning period [Day 32 postpartum]) of primiparous rabbit does (Oryctolagus cuniculus) and (2) to investigate the ovarian status at insemination time and the possible link with metabolic environment and with their reproductive performance. To this end, does were either submitted to a semi-intensive reproductive rhythm (Group S, inseminated on Day 11 postpartum) or an extensive rhythm (Group E, inseminated on Day 32 postpartum). Body energy (P < 0.05) and protein content (P < 0.001) as well as serum leptin (P < 0.05) and protein concentrations (P < 0.001) increased significantly along the postpartum period. At parturition, body lipid content was significantly lower and serum nonesterified fatty acids concentrations were significantly higher than that on Days 11 postpartum and 32 postpartum. Concerning ovarian status at insemination time, no significant differences were found in mean follicular stages, serum estradiol, progesterone, and prolactin (PRL) concentrations or in prolactin receptor (PRL-R) immunostaining. However, follicles in Group S showed a significantly higher apoptosis index than that of Group E (P < 0.001). The nuclear and cytoplasmic oocyte maturation rates of Group S were also significantly lower than that in Group E. In addition, conception rate and prolificacy were improved in Group E (P < 0.001 and P < 0.05, respectively). In conclusion, in the early postpartum period, metabolic status seems to impact negatively on ovarian follicle and oocyte quality leading to a poor reproductive outcome in primiparous rabbit does.     

七鳃鳗胆道闭锁过程中胆汁酸耐受机制研究进展

胆道闭锁(biliary atresia,BA)是一种罕见的婴幼儿肝胆疾病,其特征是纤维硬化性胆管病变,导致肝外胆管和肝内胆管阻塞或闭塞,胆汁不能向肠道排泄,胆汁酸对肝实质细胞造成严重损伤,最后导致肝硬化和肝衰竭危及生命.目前,胆道闭锁的发病机理尚不明确,临床上普遍采用"先葛西"、"后移植"的序贯性治疗方式.葛西手术(...     

Bidirectional signaling mediated by ephrin-B2 and EphB2 controls urorectal development

Incomplete urethral tubularization (hypospadias) and anorectal abnormalities are two common and poorly understood birth defects that affect the extreme caudal midline of the human embryo. We now show that cell surface molecules essential for proper axon pathfinding in the developing nervous system, namely ephrin-B2 and the ephrin receptors EphB2 and EphB3, also play major roles in cell adhesion events that tubularize the urethra and partition the urinary and alimentary tracts. Mice carrying mutations which disrupt the bidirectional signals that these molecules transduce develop with variably penetrant severe hypospadias and incomplete midline fusion of the primitive cloaca. We further show that animals completely lacking ephrin-B2 reverse signaling present a fully penetrant failure in cloacal septation. This results in severe anorectal malformations characterized by an absence of the terminal-most hindgut (rectum) and formation of a fistula that aberrantly connects the intestines to the urethra at the base of the bladder. Consistent with an apparent requisite for both forward and reverse signaling in these caudal remodeling events, EphB2 and ephrin-B2 are coexpressed at the midline in the fusing urethral/cloacal endoderm and underlying lateral mesoderm of the urorectal septum that migrates toward the caudal midline as the cloaca septates. Our data thus indicate that B-subclass Eph and ephrin molecules play an important role in these clinically significant midline cell-cell adhesion and fusion events.     

莫桑鼻给非鲫滤泡闭锁中卵黄溶致液晶的形变特征

运用透射电镜的超薄切片技术和冰冻蚀刻复型膜技术研究了莫桑鼻给非鲫滤泡闭锁过程中印黄溶致液晶YLLC的形态变化特征.结果表明、由颗粒细胞吞噬消化卵黄球所形成的YLLC通常是膜片层排列紧密的脂质体样结构,或为膜片层叠加排列的结构以及不规则的同心圆结构.这些YLLC结构不稳定,当被颗粒细胞释放后.因空间的扩大和水份的增加.YLLC吸水膨胀.形成规则的.膜间距增加的稳定脂质体样结构;YLLC能随体液流动,呈流体状.根据YLLC形态变化的行为,作者认为鱼类滤泡闭锁的生物学意义在于清除卵黄中不正常卵母细胞,并且使印黄物质重新吸收利用.但不参与内分泌激素的合成.