Abstract:

BACKGROUND: Previous studies demonstrated that many diseases can be effectively treated by using both bone marrow-derived mesenchymal-like stem cells (BM-MSCs) and bone marrow-derived mononuclear cells (BM-MNCs). BM-MSCs also have been used in lung fibrosis models. 
OBJECIIVE: To compare the curative effect of BM-MSCs and BM-MNCs for treating bleomycin A5-induced alveolitis and early fibrosis.
METHODS: BM-MSCs and BM-MNCs from Wistar male young rats were cultured and marked with 4, 6-diamidino-2-phenylindole (DAPI). A total of 21 female Wistar rats were intratracheally injected with bleomycin A5 to establish pulmonary fibrosis models. The rats were randomly divided into BM-MSCs group, BM-MNCs group and model group. The rats were sacrificed on day 7 following model induction. Pathological sections of pulmonary tissues were obtained to observe inflammation and fibrosis. Fluorocyte marked with DAPI was detected by fluorescence microscopy. The levels of hydroxyproline and tumor necrosis factors-α (TNF-α) were measured by enzyme linked immunosorbent assay (ELISA).  
RESULTS AND CONCLUSION: ①In BM-MSCs group and BM-MNCs group, BM-MSCs and BM-MNCs marked with DAPI were detected in lung frozen section. ②Pulmonary alveolitis was most serious in model group, pulmonary alveolitis and fibrosis in BM-MNCs group was more serious than BM-MSCs group, and significant differences were detected among groups (P < 0.05). ③Hydroxyproline and TNF-α levels were highest in model group, and lowest in the BM-MSCs group, and significant differences were detected among groups (P < 0.05). Results suggest that both BM-MSCs and BM-MNCs can be planted in the impaired lung tissue, and effectively prevent the development of bleomycin-induced pulmonary alveolitis and early fibrosis. The curative effect of BM-MSCs is better than that of BM-MNCs.