Objective  To evaluate the effect and mechanism of cysteine rich protein 61, namely CCN family member 1(CCN1) on the survival of adipose tissues in rats after autologous fat grafting.

  Methods  At 1 week after the establishment of autologous fat grafting rat models, all animals were randomly divided into the CCN1 group (n=20) and control group (n=20). The survival of fat grafts, the morphology of fat graft tissues, the proportion of active adipocytes and the number of new blood vessels of rats were statistically compared between two groups. The levels of differential expressed messenger ribonucleic acid (mRNA) in the fat graft tissues of rats were compared between two groups by high-throughput sequencing and subsequently subject to cluster analysis. The expression levels of related proinflammatory cytokines of fat graft tissues of rats were statistically compared between two groups.

  Results  The weight retention rate of adipose tissues in the CCN1 group was significantly higher than that in the control group (P < 0.05). In the CCN1 group, the integrity of adipocytes was considerably higher, the degree of vesiculation and vacuolation, the degree of inflammatory cell aggregation and the degree of fibrosis were significantly lower than those in the control group (all P < 0.000 1). Immunofluorescence staining demonstrated that the proportion of active adipocytes with uniform morphology was higher in the CCN1 group, whereas the proportion of active adipocytes was lower and the cells were observed in different sizes accompanied by vesiculation in the control group. Compared with the control group, the quantity of new blood vessels was significantly higher, and the expression levels of platelet derived growth factor (PDGF) and fibroblast growth factor (FGF) mRNA were remarkably higher in the CCN1 group (all P < 0.05). High-throughput sequencing analysis showed that the data at the transcriptome levels significantly differed between two groups. In the CCN1 group, the gene expression levels of cell surface markers, inflammatory cytokines and chemokines related to M1 macrophages tended to decline. Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) revealed that the mRNA expression levels of interleukin (IL)-8, IL-1 and Toll-like receptor (TLR) 2 in the CCN1 group were significantly lower than those in the control group (P < 0.01-0.05).

  Conclusions  During autologous fat grafting, supplement of exogenous CCN1 may effectively promote the neovascularization of adipose tissues and improve the survival rate of fat graft probably by mediating the transformation of macrophages into M2 phenotype via down-regulating the TLR2 expression level.