By vantal Histopathological observation results The frozen sections were stained with hematoxylin-eosin, and it was found that the dermal layer of bleomycin group was thickened, inflammatory cells infiltrated and skin appendages decreased. After the treatment of adipose-derived mesenchymal stem cells, the dermis of mouse skin became thinner and the skin appendages increased. Alveolar atrophy, collapse and cystic changes in bleomycin group and PBS group, accompanied by inflammatory cell infiltration; After treatment with adipose-derived mesenchymal stem cells, the infiltration of inflammatory cells decreased and the number of alveoli increased.In addition to these aspects, suture kit The performance in other aspects is also relatively good, which has attracted everyone’s attention and research. https://pinnaclemedics.com/
Mouse mouth gag
There was no significant difference between adipose-derived mesenchymal stem cells treatment group and normal control group, and there was no significant difference between bleomycin group and PBS control group.
2.6Masson staining results showed that there were few collagen fibers in skin tissue of normal control group mice; In bleomycin group, a large amount of collagen fibers were accumulated in the skin, and the collagen fiber bundles parallel to the epidermis increased and extended to the depths of the skin tissue in bleomycin group. The number of collagen fibers in adipose-derived mesenchymal stem cells treatment group decreased, while in PBS control group there were still many collagen fibers. Pulmonary interstitial and alveolar fibrosis were extensive in bleomycin group, and the amount of collagen fibers in lung tissue of mice in adipose-derived mesenchymal stem cells treatment group decreased.
2.7 The results of immunofluorescence detection showed that the expression of CD31 was mainly located in the cell membrane, while the expressions of collagen ◆, ■ and ▲ were mainly located in the extracellular matrix of skin and lung tissue. The levels of collagen ◆, ■ and ▲ in skin and lung tissue of normal control group and adipose-derived mesenchymal stem cells treatment group were significantly lower than those of bleomycin group. There was no significant difference in the levels of collagen ◆, ■ and ▲ in skin and lung tissue between adipose-derived mesenchymal stem cells treatment group and normal control group, and between bleomycin and PBS control group (P>0.05).
The level of CD31 protein in skin tissue of normal control group and adipose-derived mesenchymal stem cells treatment group was significantly higher than that of bleomycin group and PBS control group. There was no significant difference in CD31 protein level between adipose-derived mesenchymal stem cells treatment group and normal control group and between bleomycin and PBS treatment group (P>0.05). There was no significant difference in the expression level of CD31 protein in lung tissue among normal control group, adipose-derived mesenchymal stem cells group, bleomycin group and PBS group (P>0.05).
3. Discussion
Systemic sclerosis is an autoimmune disease with high morbidity and mortality, characterized by vascular disease and connective tissue fibrosis. At present, it is believed that its pathogenesis is related to immune abnormality, extracellular matrix metabolism abnormality and cytokine abnormality.
In the course of systemic sclerosis, the proliferation of fibroblasts will lead to excessive deposition of extracellular matrix molecules such as type ◆, type ■ and type ▲ collagen.
Mouse fixator
Most systemic sclerosis will involve the lungs, resulting in pulmonary interstitial fibrosis and pulmonary hypertension, which will cause ventilation dysfunction and ventilation dysfunction, which is the main cause of death in patients with systemic sclerosis. However, there is no effective treatment for systemic sclerosis in clinic. Because of the long course of systemic sclerosis, patients’ poor compliance, and often self-withdrawal, lost follow-up and other phenomena, clinical research often can not be carried out smoothly.
Therefore, it is very important to choose suitable animals to establish systemic sclerosis model for studying its pathogenesis and seeking new treatment methods. As early as 1999, YAMAMOTO et al. established a systemic sclerosis model mouse by using bleomycin, and proved the skin fibrosis of the model mouse by detecting the expression level of hydroxyproline. It was found that subcutaneous injection of bleomycin could induce inflammation and fibrosis for 4-6 weeks.