Versican splice variants and mRNA levels in monocytes from systemic sclerosis patients and healthy controls. (A) Molecular structure of full-length versican (V0), which has numerous chondroitin sulfate (CS) chains attached to its glycosaminoglycan (GAG)-binding domain. (B) mRNA structures of versican splice variants (V0, V1, V2 and V3). Versican is composed of a hyaluronan binding region (HABR, green), GAG-binding domains (blue and yellow), and epidermal growth factor-like, lectin-like, and complement-regulatory-like domains (EELC, red). Individual mRNA components are shown in the same color as their corresponding protein structures. Arrows denote primers used to amplify each splice variant. (C) Levels of versican V0, V1, V2, and V3 mRNA in systemic sclerosis (SSc) and control monocytes, analyzed using semi-quantitative PCR. Relative mRNA levels were calculated as a ratio of the expression level of the gene of interest to that of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Each bar in the graph denotes the mean. Differences between the two groups were analyzed by Mann-Whitney U test. NS, not significant.