在围产期,奶牛在泌乳开始时会经历更高的能量需求,与减少的干物质摄入量配对,导致负能量平衡(NEB)。过度脂解驱动的脂肪组织重塑,由NEB触发,在围产期奶牛的酮症病中有显著的贡献。然而,外周血单核细胞(PBMC)在酮症发病机制和调节脂肪组织功能中的作用尚不清楚.这里,我们研究了酮症如何影响PBMC的转录谱和分泌组,以及它对内脏脂肪组织(VAT)和皮下脂肪组织(SAT)前脂肪细胞功能的影响.根据血液β-羟基丁酸酯(BHB)浓度筛选,将21头产后荷斯坦奶牛分为亚临床酮症(SCK;BHB≥1.0mM)或对照(CON;BHB<0.8mM)。静脉内收集血样用于分离PBMC和血清代谢谱。酮病升高了循环NEFA和BHB水平,但降低了总WBC和中性粒细胞计数。评估分离的PBMC的基因表达并用于产生条件培养基(PBMC-CM),在此期间用10ng/mLLPS刺激PBMC。PBMC的总体表型在SCK和CON奶牛之间基本一致,刺激后在免疫调节细胞因子表达和PBMC-CM组成中检测到最小差异。用PBMC-CM处理从非酮症奶牛分离的前脂肪细胞以评估PBMC分泌体对脂肪细胞功能的影响。无论储库如何,与用CONPBMC-CM处理的前脂肪细胞相比,用SCKPBMC-CM处理的前脂肪细胞显示出减少的脂质积累。SAT前脂肪细胞增加了脂质代谢相关基因的表达,包括DGAT1,LIPE,FASN,与用SCKPBMC-CM处理时的增值税相比。用来自LPS刺激的PBMC的CM处理的前脂肪细胞在IL1B和IL6中表现出上调,而与PBMC的储库或来源无关。一起,这些结果表明,尽管PBMC图谱显示出最小的差异,PBMC-CM处理的前脂肪细胞可能受到其他因素的影响,导致前脂肪细胞功能和基因表达改变,可能导致脂肪细胞功能障碍。
During the periparturient period, cows undergo heightened energy demands at lactation onset, paired with reduced dry matter intake, leading to negative energy balance (NEB). Excessive lipolysis-driven adipose tissue remodeling, triggered by NEB, significantly contributes to ketosis in periparturient dairy cows. However, the role of peripheral blood mononuclear cells (PBMCs) in the pathogenesis of ketosis and in modulating adipose tissue function remains poorly understood. Here, we investigated how ketosis affects the transcriptional profile and secretome of PBMCs and its influence on preadipocyte function in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Twenty-one postpartum Holstein dairy cows were categorized as either subclinical ketosis (SCK; BHB ≥ 1.0 mM) or control (CON; BHB < 0.8 mM) based on blood beta-hydroxybutyrate (BHB) concentration screening. Blood samples were collected intravenously for the isolation of PBMCs and serum metabolic profiling. Ketosis elevated circulating NEFA and BHB levels but reduced total WBC and neutrophil counts. Isolated PBMCs were evaluated for gene expression and used to produce conditioned media (
PBMC-CM), during which PBMCs were stimulated with 10 ng/mL LPS. The overall phenotype of PBMCs was largely consistent between SCK and CON cows, with minimal differences detected in immunomodulatory cytokine expression and PBMC-CM composition following stimulation. Preadipocytes isolated from non-ketotic cows were treated with
PBMC-CM to assess the effect of
PBMC secretomes on adipose cell function. Preadipocytes treated with SCK
PBMC-CM showed reduced lipid accumulation compared to those treated with CON
PBMC-CM regardless of the depot. SAT preadipocytes had heightened expression of lipid metabolism-related genes, including DGAT1, LIPE, and FASN, compared to VAT when treated with SCK PBMC-CM. Preadipocytes treated with CM from PBMC stimulated by LPS exhibited upregulation in IL1B and IL6 regardless of the depot or source of PBMCs. Together, these results indicate that although
PBMC profiles showed minimal differences, preadipocytes treated with PBMC-CM may be influenced by additional factors, leading to altered preadipocyte function and gene expression that may contribute to adipose cellular dysfunction.