Regulatory mechanism of recombinant type Ⅲ humanized collagen protein improving photoaging skin in rats

Yang Lixia; Diao Liqin; Li Hua; Feng Yachan; Liu Xin; Yu Yuexin; Dou Xixi; Gu Huifeng; Xu Lanju

doi:10.12307/2026.565

Abstract：BACKGROUND:Type Ⅲ collagen plays an important regulatory role in skin damage and repair in the body,with properties such as anti-inflammatory,maintaining skin elasticity,and enhancing cell activity.However,the effect and specific mechanism of recombinant type Ⅲ humanized collagen in improving skin photoaging have not been elucidated. OBJECTIVE:To investigate the improvement effect and mechanism of recombinant type Ⅲ humanized collagen on photoaging skin in rats. METHODS:A total of 132 SD rats were randomly divided into 7 groups using a random number table method:except for the blank group(n=21),the ultraviolet irradiation model group(n=21),negative control group(n=18),positive control group(n=18),low-dose recombinant type Ⅲ humanized collagen group(n=18),medium-dose recombinant type Ⅲ humanized collagen group(n=18),and high-dose recombinant type Ⅲ humanized collagen group(n=18)were used to construct the skin photoaging model of the back skin of rats(irradiated once every 1 day for 12 consecutive weeks).At week 14 of modeling,the dermis of the irradiated skin of the negative control group and the positive control group was injected with normal saline and 0.5 mg/mL bovine type Ⅰ collagen solution,respectively.The dermis of the irradiated skin of the low-,medium-and high-dose recombinant type Ⅲ humanized collagen groups was injected with 0.2,0.5,and 5 mg/mL recombinant type Ⅲ humanized collagen solution,respectively.The injection was uniformly injected into 20 points,50 µL per point,once a week,for 5 consecutive weeks.The samples were collected 1,3,and 5 weeks after the injection,and hematoxylin-eosin staining,Masson staining and immunohistochemical staining were performed,respectively. RESULTS AND CONCLUSION:(1)The evaluation of the appearance of rat skin showed that the skin condition of rats treated with recombinant type Ⅲ humanized collagen was significantly improved,mainly manifested as fine and glossy skin,and wrinkles were significantly reduced or completely disappeared.(2)Hematoxylin-eosin staining results showed that with the increase of injection time,the degree of keratinization outside the epidermis of rats in the low,medium-,and high-dose recombinant type Ⅲ humanized collagen groups gradually decreased,and the collagen in the dermis gradually became neat,uniform and tight.Masson staining results showed that low-and medium-doses of recombinant type Ⅲ humanized collagen could quickly slow down the loss of collagen in tissues and promote collagen regeneration and repair in tissues.Immunohistochemical staining results showed that low-,medium-,and high-doses of recombinant type Ⅲ humanized collagen could significantly reduce the expression of matrix metalloproteinase 1 and interleukin 6 proteins in skin tissues,and increase the expression of type Ⅰ and type Ⅲ collagen.(3)The results showed that recombinant type Ⅲ humanized collagen regulated the structural composition and inflammatory infiltration of rat skin tissues through the interleukin 6/matrix metalloproteinase 1 signaling pathway,and improved the skin photoaging caused by ultraviolet irradiation in rats.