Bajpai Geetika, Simmen Rosalia C M, Stenken Julie A
Department of Chemistry and Biochemistry and Program in Cell and Molecular Biology, University of Arkansas, Fayetteville, AR 72701, USA.
Mol Biosyst. 2014 Apr;10(4):806-12. doi: 10.1039/c3mb70308h. Epub 2014 Jan 24.
Adipocytes from white adipose tissue secrete cytokines and other bioactive proteins which are collectively termed adipokines. Adiposity has been linked with increased breast cancer risk as adipokines secreted by adipocytes significantly affect epithelial cells from which breast cancer arises. Measurement of extracellular adipokine concentrations that would be involved in signaling through mammary tissue is therefore of importance. In this work, microdialysis sampling was used to collect adipokines from the interstitial space of the mammary fat pad of female rats under isoflurane anesthesia. The adipokines CCL2 (MCP-1), leptin and IL-6 were quantified from dialysate samples and compared to total tissue concentrations surrounding the implanted probes. After three hours of microdialysis sampling at 1 μL min(-1), the respective median values for these adipokines in dialysate samples were approximately 175 pg mL(-1) (CCL2), 150 pg mL(-1) (IL-6) and 750 pg mL(-1) (leptin). Adipokine protein levels from dialysates were an order of magnitude lower than levels obtained directly from mammary tissue. However, the adipokine concentrations between excised tissue surrounding the microdialysis sampling probes and control tissue without implants did not differ. This work demonstrates the utility of microdialysis sampling to quantify mammary gland adipokine levels, with relevance to understanding mammary physiology.
白色脂肪组织中的脂肪细胞会分泌细胞因子和其他生物活性蛋白，这些物质统称为脂肪因子。肥胖与乳腺癌风险增加有关，因为脂肪细胞分泌的脂肪因子会显著影响乳腺癌起源的上皮细胞。因此，测量通过乳腺组织进行信号传导所涉及的细胞外脂肪因子浓度具有重要意义。在这项研究中，采用微透析采样法，在异氟烷麻醉下从雌性大鼠乳腺脂肪垫的间质空间收集脂肪因子。从透析液样本中对脂肪因子CCL2（单核细胞趋化蛋白-1）、瘦素和白细胞介素-6进行定量，并与植入探针周围的总组织浓度进行比较。以1 μL min⁻¹ 的速度进行三小时的微透析采样后，透析液样本中这些脂肪因子的各自中位数约为175 pg mL⁻¹（CCL2）、150 pg mL⁻¹（白细胞介素-6）和750 pg mL⁻¹（瘦素）。透析液中的脂肪因子蛋白水平比直接从乳腺组织获得的水平低一个数量级。然而，微透析采样探针周围的切除组织与未植入的对照组织之间的脂肪因子浓度没有差异。这项研究证明了微透析采样在定量乳腺脂肪因子水平方面的实用性，这对于理解乳腺生理学具有重要意义。
