Cytosolic free Ca([Ca]i)was measured in dissociated cerebral cells isolated from fetal rats with the fluorescent indicater fura-2. Increase in[Ca]i occurred rapidly following explsure of the cells to 50 mmol/L KCI,1...Cytosolic free Ca([Ca]i)was measured in dissociated cerebral cells isolated from fetal rats with the fluorescent indicater fura-2. Increase in[Ca]i occurred rapidly following explsure of the cells to 50 mmol/L KCI,10mol/L Bayk 8644 or 200μmol/L glutamate（Glu）.[Ca]i elevated by展开更多
Background: There is evidence that sow heat stress(HS) during gestation affects fetal development with implications for impaired muscle growth. We have previously demonstrated that maternal HS during early to midgesta...Background: There is evidence that sow heat stress(HS) during gestation affects fetal development with implications for impaired muscle growth. We have previously demonstrated that maternal HS during early to midgestation compromised muscle fibre hyperplasia in developing fetal pigs. Thus, we hypothesised these phenotypic changes are associated with a change in expression of genes regulating fetal skeletal muscle development and metabolism. To test this, at d 60 of gestation, RNA sequencing and immunohistochemistry were performed on fetal longissimus dorsi(LD) muscle biopsies collected from pregnant gilts that had experienced either thermoneutral control(CON, 20 ℃, n = 7 gilts, 18 LD samples) or controlled HS(cyclic 28 to 33 ℃, n = 8 gilts, 23 LD samples)conditions for 3 weeks.Results: A total of 282 genes were differentially expressed between the HS and CON groups in female LD muscles(false discovery rate(FDR) ≤ 0.05), whereas no differentially expressed genes were detected in male LD muscles between the two groups(FDR > 0.05). Gestational HS increased the expression of genes associated with transcription corepressor activity, adipogenesis cascades, negative regulation of angiogenesis and pro-inflammatory signalling in female LD muscles. Immunohistochemical analyses revealed a decreased muscle vascularity density in fetuses from HS group for both sexes compared to those from the CON group(P = 0.004).Conclusions: These results reveal gilt HS during early to mid-gestation altered gene expression profiles in fetal LD muscles in a sexually dimorphic manner. The molecular responses, including transcription and angiogenesis repressions and enhanced adipogenesis cascades, were exclusively observed in females. However, the associated reductions in muscle vascularity were observed independently of sexes. Collectively this may indicate female fetal pigs are more adaptive to gestational HS in terms of gene expression changes, and/or there may be sexually dimorphic differences with respect to the timing of muscle molecular responses to gestational HS.展开更多
文摘Cytosolic free Ca([Ca]i)was measured in dissociated cerebral cells isolated from fetal rats with the fluorescent indicater fura-2. Increase in[Ca]i occurred rapidly following explsure of the cells to 50 mmol/L KCI,10mol/L Bayk 8644 or 200μmol/L glutamate（Glu）.[Ca]i elevated by
基金partially funded by Australian Pork Limited (APL2017/2216)the Postgraduate Research Scholarship and the Melbourne Research Scholarship from APL and The University of Melbourne,respectively
文摘Background: There is evidence that sow heat stress(HS) during gestation affects fetal development with implications for impaired muscle growth. We have previously demonstrated that maternal HS during early to midgestation compromised muscle fibre hyperplasia in developing fetal pigs. Thus, we hypothesised these phenotypic changes are associated with a change in expression of genes regulating fetal skeletal muscle development and metabolism. To test this, at d 60 of gestation, RNA sequencing and immunohistochemistry were performed on fetal longissimus dorsi(LD) muscle biopsies collected from pregnant gilts that had experienced either thermoneutral control(CON, 20 ℃, n = 7 gilts, 18 LD samples) or controlled HS(cyclic 28 to 33 ℃, n = 8 gilts, 23 LD samples)conditions for 3 weeks.Results: A total of 282 genes were differentially expressed between the HS and CON groups in female LD muscles(false discovery rate(FDR) ≤ 0.05), whereas no differentially expressed genes were detected in male LD muscles between the two groups(FDR > 0.05). Gestational HS increased the expression of genes associated with transcription corepressor activity, adipogenesis cascades, negative regulation of angiogenesis and pro-inflammatory signalling in female LD muscles. Immunohistochemical analyses revealed a decreased muscle vascularity density in fetuses from HS group for both sexes compared to those from the CON group(P = 0.004).Conclusions: These results reveal gilt HS during early to mid-gestation altered gene expression profiles in fetal LD muscles in a sexually dimorphic manner. The molecular responses, including transcription and angiogenesis repressions and enhanced adipogenesis cascades, were exclusively observed in females. However, the associated reductions in muscle vascularity were observed independently of sexes. Collectively this may indicate female fetal pigs are more adaptive to gestational HS in terms of gene expression changes, and/or there may be sexually dimorphic differences with respect to the timing of muscle molecular responses to gestational HS.
文摘胎儿生长受限(fetal growth restriction,FGR)是一种常见的产科疾病,其可导致新生儿低出生体质量和出生后肌肉量减少。这可能与肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和白细胞介素-6(interleukin-6,IL-6)的调控密切相关。研究发现,这两种炎症因子在FGR胎儿中表达水平异常,可通过影响成肌细胞的增殖和分化,干扰正常骨骼肌的发育。此外,TNF-α与IL-6还可以激活特定的信号通路,如核因子κB(nuclear factor-κB,NF-κB)、Janus激酶/信号转导及转录活化因子(Janus kinase/signal transducer and activator of transcription,JAK/STAT)、丝裂原激活的蛋白激酶(mitogen-activated protein kinase,MAPK)等信号通路,调节肌细胞的代谢和功能。如使用特定的抗炎药物或生物制剂来降低TNF-α和IL-6的活性,可能有助于改善FGR胎儿的骨骼肌发育。总的来说,TNF-α和IL-6在FGR胎儿骨骼肌发育中的作用是一个多层面、复杂的过程,需要进一步的深入研究来阐明其具体机制,帮助理解FGR的病理生理学,并为治疗FGR胎儿提供新的思路。
