| Our aim in selecting an appropriate cell fraction and conditioned media (CM) was to
achieve the suitable candidate for ameliorating long-term chronic asthmatic changes of respiratory tract.
Thirty-six rats were classified into healthy and sensitized groups, which were further divided into three
subgroups; rats received systemically 50 μl volume of PBS, CM, or 2 × 106 rat bone marrow-derived
mesenchymal stem cells (rBMMSCs). Tracheal responsiveness (TR), immunologic responses, and
recruitment of rBMMSCs into the lungs were evaluated. A high degree of TR and total WBC and
percentages of eosinophils and neutrophils was significantly recorded in all sensitized groups rather than
of controls (p < 0.001 to p < 0.05). Concurrently, a significant improvement of TR and eosinophil and
neutrophil return toward normal levels was evident in sensitized rats receiving cells as compared to
parallel asthmatic animals. Flow cytometric monitoring of lymphocyte subpopulation revealed a
decrease in the number of CD3+CD4+ and concurrent increase in CD3+CD8+ in all sensitized rats as
compared to control (p < 0.001 to p < 0.05). Noticeably, no significant modulatory effects of either cell
or CM administration were achieved on the CD3+CD4+ and CD3+CD8+ populations in non-asthmatic
rats. Corroborating our results, the number of CD3+CD4+ tended to increase (p < 0.05) which coincided
with a decreased manner of CD3+CD8+ populations as compared to other asthmatic groups (p < 0.01 to
p < 0.05).Moreover, stem cells could efficiently transmigrate to the lung parenchyma, albeit the dynamic
of asthmatic changes stimulated the rate of recruited cells. Our study shed light on superior effects of
mesenchymal stem cells, but not CM, in attenuating chronic asthmatic changes in the model of rat. |