van Beek E A, Bakker A H, Kruyt P M, Vink C, Saris W H, Franssen-van Hal N L W, Keijer J
RIKILT-Institute of Food Safety, Wageningen UR, Wageningen, The Netherlands.
Int J Obes (Lond). 2008 Jun;32(6):912-21. doi: 10.1038/ijo.2008.10. Epub 2008 Feb 19.
To obtain insight in the extent to which the human cell lines LiSa-2 and PAZ6 resemble isolated primary human adipocytes.
A combination of cDNA subtraction (representative difference analysis; RDA) and cDNA microarray analysis was used to select adipose specific genes to compare isolated (pre-)adipocytes with (un)differentiated LiSa-2 and PAZ6 cells.
RDA was performed on adipose tissue against lung tissue. A total of 1400 isolated genes were sequenced and cDNA microarray technology was used for further adipose related gene selection. 30 genes that were found to be enriched in adipose tissue were used to compare isolated human adipocytes and LiSa-2 and PAZ6 cells in the differentiated and undifferentiated states.
RDA and microarray analysis resulted in the identification of adipose enriched genes, but not in adipose specific genes. Of the 30 most differentially expressed genes, as expected, most were related to lipid metabolism. The second category consisted of methyltransferases, DNMT1, DNMT3a, RNMT and SHMT2, of which the expression was differentiation dependent and higher in differentiated adipocytes. Using the 30 adipose expressed genes, it was found that isolated adipocytes on one hand, and PAZ6 and LiSa-2 adipocytes on the other, differ primarily in lipid metabolism. Furthermore, LiSa-2 cells seem to be more similar to isolated adipocytes than PAZ6 cells.
The LiSa-2 cell line is a good model for differentiated adipocytes, although one should keep in mind that the lipid metabolism in these cells deviates from the in vivo situation Furthermore, our results imply that methylation may have an important function in terminal adipocyte differentiation.
了解人细胞系LiSa - 2和PAZ6在多大程度上类似于分离的原代人脂肪细胞。
采用cDNA消减（代表性差异分析；RDA）和cDNA微阵列分析相结合的方法，选择脂肪特异性基因，以比较分离的（前）脂肪细胞与未分化及分化的LiSa - 2和PAZ6细胞。
对脂肪组织与肺组织进行RDA。共对1400个分离的基因进行测序，并使用cDNA微阵列技术进一步选择与脂肪相关的基因。用30个在脂肪组织中富集的基因比较分离的人脂肪细胞以及处于分化和未分化状态的LiSa - 2和PAZ6细胞。
RDA和微阵列分析鉴定出了在脂肪组织中富集的基因，但未鉴定出脂肪特异性基因。在30个差异表达最显著的基因中，如预期的那样，大多数与脂质代谢有关。第二类包括甲基转移酶DNMT1、DNMT3a、RNMT和SHMT2，其表达依赖于分化，在分化的脂肪细胞中更高。利用这30个在脂肪组织中表达的基因发现，一方面分离的脂肪细胞与另一方面的PAZ6和LiSa - 2脂肪细胞，主要在脂质代谢方面存在差异。此外，LiSa - 2细胞似乎比PAZ6细胞更类似于分离的脂肪细胞。
LiSa - 2细胞系是分化脂肪细胞的良好模型，不过应该记住这些细胞中的脂质代谢与体内情况有所不同。此外，我们的结果表明甲基化可能在脂肪细胞终末分化中具有重要作用。
