Study on wound healing and autophagy of yak achilles tendon collagen sponge in tanggulat burn rats

LI Yi; FENG Yanping; DUAN Rui; LYU Zhifeng; WANG Hua; WANG Hongjin

doi:10.3969/j.issn.1673-7040.2025.07.001

Abstract：Objective To study the effect of yak Achilles tendon collagen composite sponge on the healing of second-degree burn wounds in rats,and to clarify the regulatory effect of the composite sponge on the proliferation and autophagy of rat epidermal cells.Methods From January 2022 to December 2024,Department of Burn and Plastic Surgery,Qinghai Affiliated Hospital were randomly di-vided male SD rats into 4 groups(6 rats in each group):normal control group(Con),model group(Mod),yak Achilles tendon collagen sponge burn group(CPS)and Tanggulat burn liquid yak Achilles tendon collagen composite sponge burn group(CS).Three second-degree burn wounds with a diameter of 1.5 cm were caused on the back of rats,and the wound diameters were measured at 3,7,14 and 28 days,and the protein expressions of LC3,Beclin-1,TGF-β1 and PCNA in skin tissue homogenate were detected.Rat epidermal cells were treated synchronously after passage to the third passage,and they were intervened with normal serum(blank control),simulated burn serum,burn serum,burn serum+petroleum jelly gauze and burn serum+Tanggulat burn liquid yak Achilles tendon collagen composite sponge(composite sponge group)for 24 hours.The cell proliferation rate and the expression levels of PCNA,LC3 and Beclin-1 were measured.Results Animal experiments showed that compared with the normal control group(Con),the autophagy-related proteins Beclin-1 and LC3 in the model group(Mod)increased significantly after burns from the 3rd day,peaked on the 7th day,and basically recovered on the 28th day.The expression levels of these two proteins in rat tissues in the CPS and CS treatment groups were significantly lower than those in the Mod group,and the effect in the CS group was more obvious.In the Mod group,the proliferation-related protein PCNA was significantly increased in the early stage of treatment and decreased on the 28th day.The expression level of TGF-β1 was always lower than that in the Con group.The expressions of PCNA and TGF-β1 in the CPS and CS treatment groups were significantly higher than those in the Mod group,and the effect in the CS group was more significant.Cell experiments showed that compared with the normal serum group,the cell proliferation rate and PCNA protein concentration of each treatment group(burn serum group,burn serum+petroleum jelly gauze group,burn serum+composite sponge group)decreased,while the protein expression of Beclin-1 and LC3 increased.At the same time,the same trend was also shown in each treatment group compared with the simulated burn serum group.However,the cell proliferation rate and PCNA protein concentration of the burn serum+composite sponge group were higher than those of the burn serum group and the burn serum+petroleum jelly gauze group,and the expression of Beclin-1 and LC3 proteins also showed the same trend.Conclusion(1)Composite sponge can reduce the expression of Beclin-1 and LC3 in the skin tissue of burned rats,and alleviate the tissue damage caused by exces-sive autophagy.(2)The composite sponge increased the expression of TGF-β1 and PCNA in the skin of burned rats,and promoted cell pro-liferation and wound healing.(3)Early intervention of burn serum led to a decrease in the proliferation rate and PCNA of epidermal cells and an increase in autophagy-related proteins LC3 and Beclin-1.(4)Tangulat composite sponge can regulate the proliferation of epidermal cells and the expression of autophagy-related proteins after burn serum intervention.