Microscopic Changes of Lung Inflammation in Pre-Clinical Stem Cell Therapy

Background: Acute respiratory distress syndrome (ARDS) is diffusive damage to the pulmonary parenchyma. Animal mod-els limitation of ARDS has disclosed the pathogenesis and pathophysiology of this clinical syndrome. Although progress in understanding the pathogenesis of ARDS and in intensive care medicine has been satisfactory, the treatment approach is still depending on the diagnosis of the clinical view. Apply-ing these models have evaluated different novel treatment ap-proaches for ARDS. There are many different reason which can initiate and induce ARDS. Animal experiments seem invaluable tools for exploring the pathogenesis and for evaluating novel treatment approaches to ARDS.Materials and Methods: Experimental model of ARDS were induced by intratracheal delivery of LPS in 10 males white New Zealand rabbits. Then, in the treatment group BM-MSCs were isolated and cultured and 107 cells were autographed and PBS was injected in the control group intratrachealy. The rabbits were sacrificed seven days after transplantation. Then, the tho-racic cavity was cut, and the lungs was ligatured, dissected and removed from the chest. Sections of the lungs were fixed and the process was routinely done.Results: Sections of the lung shows severe histopathological patterns in the control group compared to the treatment group as hemorrhage in parenchyma and alveoli, moderate to severe vascular hyperemia and interstitial pneumonia, severe alveolar injuries and edema, neutrophilic margination in the capillary vessels, abundant presence of inflammatory cells, epithelial cells and other cell debris in interstitial spaces and alveoli and thickness of inter-alveolar septum. But in the treatment group, BM-MSCs reduced the infiltration rate of inflammatory cells in intra-alveolar, hyperemia, hemorrhage and edema, and also lungs structure were approximately normal and the thickness of the alveolar septum were slightly increased.Conclusion: We demonstrated that MSCs could attenuate the inflammation by reducing pathological lung changes.