ABSTRACT
Objective To study and confirm that mouse bone marrow-derived mesenchymal stem cells (MSCs) could promote the repair of mouse pulmonary microvascular endothelial cells (PMVECs) by transferring mitochondria, providing a new idea for the treatment of ARDS. Methods This study was divided into four groups: control group, injuryed group, group of MSC and MSC-oli (loss-of-function of mitochondrial). PMVECs induced by lipopolysaccharide (LPS) were co-cultured with MSC and MSC-oli in transwell chamber. The transfer of mitochondria was observed under confocal microscopy. The expression of mitochondria-associated proteins(CYP1A1,CYP1A2), synthesis-related proteins (eNOS, iNOS) and connexin protein (VE-cadherin) were detected by Western Blot. The permeability of endothelial cell was evaluated by fluorescein isothiocyanate-dextran method. And the apoptosis rate of endothelial cells was evaluated by flow cytometry and JC-1 membrane potential. Results It showed that both MSC and MSC-oli groups could deliver mitochondria from MSC to PMVEC under confocal fluorescence microscopy. The results of Western blot showed the expression of CYP1A1, CYP1A2 and eNOS in endothelial cells of MSC-oli group was significantly lower than that in MSC group (P<0.05). The expression of iNOS was significantly higher than that in MSC group (P<0.05). But there was no significant difference in the expression of VE-cadherin (P>0.05). The dextran method showed that the permeability was significant reduced in MSC-oli group compared with the MSC group (P<0.05). Flow cytometry and JC-1 membrane potential showed that the rate of apoptosis was lower in MSC-oli group compared to the MSC-oli group (P<0.05). Conclusion MSCs could alleviate the damage of PMVECs by transmitting mitochondria.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the feasibility of the tissue engineered submandibular gland constructed in vivo based on submandibular gland cells and silk fibroin-chitosan (SFCS).</p><p><b>METHODS</b>Submandibular gland cells were obtained and purified. The second generation cells labeled by 5'-BrdU were seeded on SFCS(5 mm × 5 mm × 5 mm). Submandibular gland cells seeded on SFCS was implanted beneath the skin on the back. At 3, 7, 14 d post-implantation, implant sites were examined local and systemic responses. After paraffin embedding, serial sections 6 mm thick were cut and stained with either hematoxylin and eosin or brdu tissue stain for immunohistochemical studies and examined the responses of tissue. Scanning electron microscope was used to observe the growth behavior submandibular gland cells on SFCS scaffolds.</p><p><b>RESULTS</b>General observation: at the 3, 7, 14 d after in vivo implantation, capsule formed in the surface of insert. Histological observation: in experimental group, submandibular gland cells proliferate on the SFCS scaffold fused to form unit 14 d after implantation. Brdu immunohistochemical observation: the results of labelled cells were positive by immunohistochemical method at each time point. Cytokeratin-8 (CK-8) immunohistochemical observation: the results of labelled cells were positive by immunohistochemical method at each time point. With time, the positive cells gradually increased. Scanning electron microscope: the shape of the SFCS scaffold was mesh. At earlier, submandibular gland cells presence in disorder at attach to the SFCS. At the 14 d submandibular gland cells proliferate on the SFCS scaffold and form functional unit.</p><p><b>CONCLUSIONS</b>Such constructed tissue engineered submandibular gland based on submandibular gland cells and SFCS is promising.</p>
Subject(s)
Animals , Female , Male , Rats , Cell Proliferation , Cells, Cultured , Chitosan , Chemistry , Fibroins , Chemistry , Keratin-8 , Metabolism , Rats, Sprague-Dawley , Submandibular Gland , Cell Biology , Metabolism , Tissue Engineering , Methods , Tissue Scaffolds , ChemistryABSTRACT
It is generally believed that liposomes modified with polyethylene glycol (PEG) have no or lower immunogenicity. However, based on many recent literatures, when the PEGylated liposomes were repeatedly applied to the same animal, the immune responses occurred. The first injection of PEGylated liposomes resulted in a reduction in the circulation time and an increase in hepatic and splenic accumulation of the second dose of PEGylated liposomes in a time-interval, which was called "accelerated blood clearance (ABC)" phenomenon. Such immunogenicity of PEGylated liposomes presents a barrier in the research of liposomal formulations and their use in the clinics. This review focused on the definition, the method of verification, the development of the reason for ABC phenomenon, influencing factors of ABC phenomenon, and discussed if other PEGylated nanocarriers also induce ABC phenomenon.