ABSTRACT
Objective To study the potential efficacy of transplanted bone marrow-derived mesenchymal stem cells (MSCs) in treating and repairing the acute lung injury in animal models. Methods MSCs were isolated from mouse bone marrow, cultrued and amplified in vitro. The lipopolysaccharide (LPS) was inhaled through postnasal tract to cause acute lung injury in mice and the MSCs labeled by Brdu were administrated via vein into the mice. The migration and differention of the cells were identified by immunostaining and double immunostaining. The pathological changes, pulmonary edema index and the content of IL-1β in lung homogenate were used to accese the therapeutical effect of MSCs. Results The cultured MSCs dispalyed a positive CD44 and a negative CD34. The Brdu-labeled cells were detected in the lungs of the recipient 4 days after transplantation, indicating its origin of MSCs. Theses cells also exhibited characteristics of aveolar epithelials, expressing the cytokeratin-the marker of epithelium. Compared with the injuried ones, the mice treated with MSCs showed a decreased pulmonary edema in-dex and IL-1β content in the lung homogenate. Conclusion These data suggest a therapeutical effects of MSCs in treating and repairing the mouse acute lung injury.
ABSTRACT
AIM and METHODS: The effects of angiotensin II(AngII) on the activation of three transcription factors were investigated by using EMSA and western-blot methods in endothelial cells respectively. RESULTS: The EMSA results showed that AngII stimulation could increase NF-κB, SP-1 and AP-1 activation in ECV304, which suggested that activity changes in these three transcription factors could partly contribute to the dysfunction of endothelial cells.The binding affinity of NF-κB, SP-1 and AP-1 with corresponding oligonucleotides in AngII-treated ECV-304 were respectively 10.98,3.89,1.33 times as large as in control. The nuclear appearance of AngII-activated NF-κB was examined by western-blot, which corroborates our results from EMSA analysis. While as the protein appearance of AP-1 and SP-1 in nucleus, were little higher than the control group. The result of western-blot suggested that AngII-induced EC activation of these three transcription factors maybe mainly due to the enhanced binding ability to its corresponding cis-acting factors. CONCLUSION: NF-κB, a ubiquitously exposed nuclear transcription factor, is involved, together with SP-1,AP-1, in the regulation of endothelial cell dysfunction related to cardiovascular diseases such as atherosclerosis and hypertension.
ABSTRACT
AIM: To determine whether the high mobility group protein I (HMGI) is able to bind to the upstream sequence of platelet-derived growth factor B-chain gene and to characterize the HMGI-binding AT-rich regions. METHODS: Recombinant human HMGI (rhHMGI) protein was prepared and electrophoresis mobility shift assay (EMSA) was used. RESULTS: The binding of rhHMGI to PDGF-B (-1 758 / +43 bp) was observed in vitro. Two major HMGI-binding fragments -1 392 / -1 180 bp and -188 / +43 bp were identified, which contained the same AT-rich sequence TTTATAAA (-1 333 / -1 326 bp, -1 314 / -1 307 bp and -30 / -23 bp). An oligonucleotide bound to the TTTATAAA and the GAGACC, the core sequence of the shear stress response element of the PDGF-B, could also bind to the HMGI. Furthermore, HMGI facilitated the binding of NF-?B to the GAGACC in the oligonucleotide. CONCLUSION: The HMGI could bind to the upstream sequence of the PDGF-B gene via the AT-rich sequence TTTATAAA, which may play a role in the transcriptional regulation of the PDGF-B gene.