Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of ...Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs.展开更多
作者采用中国渤海湾盐田固有的渤海湾孤雌生殖卤虫(Bohai Bay Artemia parthenogenetica,BHB)和分别源自美国旧金山湾盐田(SFB)与越南Vinh Chau人工养殖(VSFB)的两性生殖卤虫(A.franciscana),研究盐度(分别为70,125和180)对上述品系卤...作者采用中国渤海湾盐田固有的渤海湾孤雌生殖卤虫(Bohai Bay Artemia parthenogenetica,BHB)和分别源自美国旧金山湾盐田(SFB)与越南Vinh Chau人工养殖(VSFB)的两性生殖卤虫(A.franciscana),研究盐度(分别为70,125和180)对上述品系卤虫存活和生殖力的影响。结果表明,在实验盐度范围内,所有品系卤虫存活率随盐度升高而显著降低,但与BHB卤虫相比,SFB和VSFB卤虫对高盐度的耐受力较强。盐度显著影响BHB卤虫性成熟时间和产后代间隔时间,并随盐度的升高而延长,但对SFB和VSFB卤虫没有显著影响。所有品系卤虫每窝产幼体或产卵数量均随盐度升高而有降低的趋势。较低盐度(70)下,BHB卤虫以产幼体占绝对优势,VSFB产幼体较多,SFB产卵较多;而在较高盐度(125和180)下,VSFB以产幼体占绝对优势,SFB和BHB也以产幼体居多。总之,与SFB和BHB相比,VSFB在高盐环境下存活率较高,且以产幼体占绝对优势,表明VSFB卤虫更适应于高盐盐田环境,有利于该品系卤虫在盐场建立优势种群。展开更多
The interaction between silicotungstic heteropolyacid and bovine hemoglobin (BHb) was investigated using fluorescence and UV-Vis. The experimental results show that the fluorescence quenching of BHb by silicotungstic ...The interaction between silicotungstic heteropolyacid and bovine hemoglobin (BHb) was investigated using fluorescence and UV-Vis. The experimental results show that the fluorescence quenching of BHb by silicotungstic heteropolyacid is a result of the formation of SiW-BHb complex; and the quenching mechanism is mainly static quenching. The binding site number n, apparent binding constant KA and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BHb was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Electrostatic interaction plays a major role in stabilizing the complex. The effect of silicotungstic heteropolyacid on the conformation of BHb was analyzed using synchronous fluorescence spectroscopy.展开更多
基金supported by the grants from the National Key Research and Development Program of China(2023YFD1800804 and 2023YFD1801100)the National Natural Science Foundation of China(32172926)the China Agriculture Research System(CARS-36)。
文摘Ketosis,a common metabolic disease during early lactation,is associated with high circulating levels ofβ-hydroxybutyrate(BHB).A portion of BHB that reaches the mammary gland is utilized as precursor for synthesis of fatty acids.Recent findings from nonruminant studies revealed that long chain fatty acyl-CoA ligase 4(ACSL4)could play a role in the regulation of cellular fatty acid metabolism,but the mechanisms by which ACSL4 mediates cellular lipid metabolism in response to BHB remains unclear.To achieve the aims,we conducted in vivo or in vitro analyses using bovine mammary gland biopsies and the immortalized mammary epithelial cell line(MAC-T).The in vivo study(n=6 cows per group)involved healthy cows(plasma BHB<0.60 mmol L^(–1))or ketotic cows(plasma BHB>2.0 mmol L^(–1))from which mammary gland tissue was biopsied.In vitro,MAC-T cells were challenged with 0,0.3,0.6,1.2,or 2.4 mmol L^(–1)BHB for 24 h to determine an optimal dose.Subsequently,MAC-T were incubated with 1.2 mmol L^(–1)BHB for 0,3,6,12,24,or 48 h.Furthermore,MAC-T cells were treated with small interfering ACSL4(siACSL4)for 24 h or ACSL4 overexpression plasmid(pcACSL4)for 36 h followed by a challenge with 1.2 mmol L^(–1)BHB for 24 h.Results showed that increased mRNA and protein abundance of lipogenic genes were linked to both mammary gland and in vitro challenge with BHB.BHB increased fatty acid content by activating ACSL4 expression,whereas inhibition of ACSL4 reduced BHB-induced reactive oxygen species(ROS)overproduction,enhancement of mitochondrial membrane potential,increase in fatty acid content,and lipid droplet accumulation.Furthermore,we also elevated ACSL4 expression with an overexpression plasmid to clarify its molecular role in response to BHB challenge.ACSL4 overexpression enhances BHB-induced lipid droplet accumulation by increased fatty acid content.Overall,the information showed that ACSL4 is crucial for the process of producing fatty acids from exogenous BHB.Reduced ACSL4 decreased fatty acid content and lipid droplet accumulation,improved mitochondrial function,directed more fatty acids towards oxidation.Thus,ACSL4 plays an important role in determining the fate of intracellular fatty acids and BHB in BMECs.
文摘作者采用中国渤海湾盐田固有的渤海湾孤雌生殖卤虫(Bohai Bay Artemia parthenogenetica,BHB)和分别源自美国旧金山湾盐田(SFB)与越南Vinh Chau人工养殖(VSFB)的两性生殖卤虫(A.franciscana),研究盐度(分别为70,125和180)对上述品系卤虫存活和生殖力的影响。结果表明,在实验盐度范围内,所有品系卤虫存活率随盐度升高而显著降低,但与BHB卤虫相比,SFB和VSFB卤虫对高盐度的耐受力较强。盐度显著影响BHB卤虫性成熟时间和产后代间隔时间,并随盐度的升高而延长,但对SFB和VSFB卤虫没有显著影响。所有品系卤虫每窝产幼体或产卵数量均随盐度升高而有降低的趋势。较低盐度(70)下,BHB卤虫以产幼体占绝对优势,VSFB产幼体较多,SFB产卵较多;而在较高盐度(125和180)下,VSFB以产幼体占绝对优势,SFB和BHB也以产幼体居多。总之,与SFB和BHB相比,VSFB在高盐环境下存活率较高,且以产幼体占绝对优势,表明VSFB卤虫更适应于高盐盐田环境,有利于该品系卤虫在盐场建立优势种群。
文摘The interaction between silicotungstic heteropolyacid and bovine hemoglobin (BHb) was investigated using fluorescence and UV-Vis. The experimental results show that the fluorescence quenching of BHb by silicotungstic heteropolyacid is a result of the formation of SiW-BHb complex; and the quenching mechanism is mainly static quenching. The binding site number n, apparent binding constant KA and corresponding thermodynamic parameters were measured at different temperatures. The process of binding SiW molecule on BHb was a spontaneous molecular interaction procedure in which entropy increased and Gibbs free energy decreased. Electrostatic interaction plays a major role in stabilizing the complex. The effect of silicotungstic heteropolyacid on the conformation of BHb was analyzed using synchronous fluorescence spectroscopy.
