Comparisons of extracellular matrix-related gene expression levels in different adipose tissues from Korean cattle

Adipose tissues are related to the meat quality and economic value of cattle. In particular, the extracellular matrix (ECM) is an important factor that influences adipose tissue remodeling. The objective of this study was to measure the expression levels of ECM-related genes in different adipose tissues from bulls, cows, and steers of Korean cattle (Hanwoo). The sample tissues were separated from omental (OM), subcutaneous (SC), and intramuscular (IM) adipose tissues. The expression levels of 24 ECM-related genes and proteins were determined using real-time PCR and Western blot analysis, respectively. We also observed that castration resulted in increased (P<0.05) expression of 17 genes, whereas it caused decreased (P<0.05) expression of COL1A2, MMP1, MMP3, MMP7, and VCAM1 in the OM adipose tissue of cows and steers compared to bulls. The mRNA levels of 24 ECM-related genes were similar between IM and SC adipose tissues. Furthermore, except for ITGB1 (IM), ICAM1 (IM), and COL1A1 (OM), the expression levels were generally similar between cows and steers compared to bulls. The FN1, MMP7, and LOX mRNA levels exhibited significantly strong (P<0.001) positive correlations (r=0.74, r=0.73, and r=0.74, respectively) with the marbling score. The protein levels can reflect the mRNA levels. Therefore, our findings suggest that castration affects the expression levels of ECM-related genes, which is in accordance with different fat depots.