Meanwhile, hUC-MSCs administration clearly increased the production of the anti-inflammatory cytokines IL-10 and TNF-a stimulated gene/protein 6 which were main players in the anti-inflammatory cytokine profile of hUC-MSCs. The blood supply is the key to wound healing. Several studies have demonstrated that MSC-secreted paracrine some nutrition factors such as VEGF, basic fibroblast growth factor and hepatocyte growth factor promoted neovascularization of injured tissues. Several studies also revealed the capacity of MSCs to improve tissue vascularity by promoting endothelial cell sprouting through soluble factor secretion. Our study also found that hUC-MSCs increased the level of VEGF in severe burn wounds and promote wound angiogenesis. Furthermore, we speculated that hUC-MSCs accelerated the severely burned wound healing by paracrine VEGF to increase wound angiogenesis. Collagen as a structurally and functionally pivotal molecule, which builds a scaffold in the connective tissue, is also involved in every stage of wound healing. Collagen types I and III are the main collagen types of healthy skin. Furthermore, the ratio of collagen types I and III in wounds being predominantly determined wound healing process. Our results showed that hUC-MSCs can modify collagen types I and III accumulation and upregulated the ratio of collagen types I and III in the severely burned wound. A previous study also showed that MSCs promoted wound repair through secretion of collagen type I and alteration of gene expression in dermal fibroblasts. hUC-MSC transplantation accelerated the wound closure of severe burns by encouraging the migration of hUC-MSCs, modulating the inflammatory environment, promoting the formation of a well-vascularized granulation matrix and collagen scaffold. These data may thus provide a theoretical foundation for further clinical application of hUC-MSCs in severe burn patients. C1q/TNF-related proteins are secreted proteins with notable metabolic functions. CTRPs, and the insulin-sensitizing adipokine adiponectin, belong to the C1q family, resemble each other in overall domain structure and organization, and share sequence homology with the globular domain of immune complement C1q. Each CTRP has a unique tissue expression profile and most circulate in plasma as multimeric glycoproteins. Functional studies of CTRPs in mice suggest non-redundant metabolic, vasculoprotective, and cardioprotective functions for this class of secreted hormones. We identified CTRP2 as a secreted protein homologous to adiponectin. CTRP2 shares 42% amino acid identity with adiponectin at the presumed functional globular C1q domain and is expressed predominantly in adipose tissue. It also circulates as a trimeric glycoprotein in plasma. Expression of Ctrp2 transcript is up-regulated in young but not older leptin-deficient ob/ob mice; this is thought to be a compensatory response to leptin deficiency prior to the development of morbid obesity and severe insulin resistance. Recombinant CTRP2 activates the conserved energy sensor AMP-activated protein kinase in a dose-dependent manner, similar to adiponectin.