Gene Expression of CCN Family Members in Young and Aged Human Skin In Vivo

Abstract

CCN family members are involved in a variety of cellular functions including proliferation, adhesion, migration, differentiation, and regulation of extracellular matrix production. Altered expression of CCN family members are associated with several pathological states, including tissue fibrosis, inflammation, and cancer. We have previously reported that CCN1 and CCN2 are predominantly expressed in dermal fibroblasts, and are involved in aberrant collagen homeostasis in aged skin (Quan et al. J Invest Dermatol 119: 499–506, 2002b; Quan et al., Am J Pathol 169: 482–90, 2006; Quan et al., J Invest Dermatol, 2009a). However, the role of the other four CCN proteins in the aging process is largely unknown. Here, we investigated gene expression of CCN3, CCN4, CCN5, and CCN6 in young and aged human skin in vivo. Transcripts for CCN3, CCN4, CCN5, and CCN6 genes were expressed in full-thickness young adult human skin in vivo. CCN5 was most highly expressed, followed by CCN3>CCN4>CCN6. Interestingly, mRNA levels of all four of these growth arrest-associated CCN members were significantly elevated in aged, compared to young human skin in vivo. These data provide a foundation for investigating the functional roles of CCN gene products in cutaneous biology and human skin aging.