Histopathological Observation Of The Supernatant Of HAMSCs To The Ance Inflammatory Rat Model

Objective To clarify the existence of anti-inflammatory cytokines IL-10 and IL-1 receptor antagonists in the supernatant of human amniotic mesenchymal stem cells(h AMSCs). To observe the effect of the supernatant to the acne rat model from gross and histopathological aspects, and clarify the anti-inflammatory action of h AMSCs. To assess the anti-inflammatory action of h AMSCs, hope to provide new experimental basis and clinical treatment of acne.Methods The IL-1ra、IL-10 level in the supernatant of h AMSCs were analyzed by double antibodies sandwich ABC-ELISA method. 40 SD rats, weighing 250±20g, were divided into 4 groups randomly: blank control group, saline-injected group, acne inflammation model group and the supernatant of h AMSCs injection group. Blank control group remained unhandled; 50μL physiological saline was injected into the central of left ears of SD rats in the group of saline-injected; in the acne inflammation model group, the Propionibacterium acnes was injected into the left ears of the rats; two days after the acne inflammation model established, 50μL supernatant of h AMSCs was injected into the lesions every two days. Observe the changes after the injection. Nine days later, the rats were sacrificed for histopathological observation. The number of inflammatory cells was counted at high magnification.Result The IL-1ra level in the supernatant of h AMSCs was 33.33±13.73pg/ml, while the IL-10 level was 5.57±4.10pg/ml. Gross observation revealed: no significant changes were observed in blank control group; after the injection, the ears of the rats in saline-injected group became swelling, 24 hours later, the swelling subsided; while in acne inflammation model group, the ears remained swelling, gradually formed some red papules at the local skin; in the supernatant of h AMSCs injection group, the persistent swelling gradually went down 2days later. An observation under microscope: in blank control group, epidermis, dermis and subcutaneous tissue were clear, no obvious inflammatory cells were found; in saline-injected group, each level of the skin was well-organized, and no obvious inflammatory cells were found in the other parts. In acne inflammation model group, the structure of subcutaneous tissue disappeared, inflammatory cells infiltrated, some part of the tissue abscessed, part of the hair follicle area and the pilosebaceous orifice expanded, sebaceous glands disappeared, in the supernatant of h AMSCs injection group, the sebaceous follicle had narrowed with a few inflammatory cells scattered. The inflammatory cells count showed: compared with the blank group, the inflammatory cells count in the normal saline group was not statistically significant(P>0.05). The number of the inflammatory cells of the supernatant of h AMSCs injection group was significantly lower than that of the inflammatory cells in acne inflammation model group(P<0.05). There was no statistically significant between the number of inflammatory cells in the saline-injected group compared with the supernatant of h AMSCs injection group(P>0.05).Conclusion The anti-inflammatory cytokines IL-10 and IL-1 receptor antagonists existed in the supernatant of h AMSCs. After the injection of the supernatant of h AMSCs, the inflammatory response in acne rat model reduced, and the number of the inflammatory cells was significantly lower than that of the inflammatory cells in acne inflammation model group, there was no statistically significant between the number of inflammatory cells in the saline-injected group. Revealed that the supernatant of h AMSCs had anti-inflammatory properties that could inhibit the inflammatory reaction caused by acne.