RESUMO
Engraftment of mesenchymal stem cells (MSC) in peripheral tissues for replenishing of local stem cell function has been proposed as a therapeutic approach to degenerative diseases. We have previously reported the development of an immortalized human telomerase reverse transcriptase transduced MSC line (hMSC-TERT). In the present study, we co-transduced hMSC-TERT with enhanced green fluorescent protein gene, and studied tissue distribution, engraftment, and cell survival after intracardiac and intravenous injections in immunodeficient mice. The pattern of organ distribution suggested that infused cells were efficiently arrested in microvasculature during first-pass, but only for a fraction of the infused cells was arrest followed by vascular emigration and tissue engraftment. Few engrafted cells in lungs, heart, and kidney glomeruli remained after 4 weeks. These observations are consistent with several reports on limited systemic transplantability of primary MSC. HMSC-TERT may constitute a valuable tool for mechanistic studies on how to control MSC homing and engraftment.
Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/citologia , Telomerase/genética , Telomerase/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Movimento Celular , Proteínas de Ligação a DNA , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Camundongos , Especificidade de Órgãos , Osteoblastos/citologia , Osteoblastos/metabolismo , Fenótipo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução GenéticaRESUMO
Rat monoclonal antibodies (MoAbs) against mouse mannan-binding lectin (MBL)-A and MBL-C were generated and assays for MBL-A and MBL-C were constructed. This allowed for the quantitative analysis of both proteins for the first time. Previously only MBL-A has been quantified using less standardized methods. In a mouse serum pool the concentrations were now determined at 7.5 microg MBL-A and 45 microg MBL-C per ml. On gel permeation chromatography of mouse serum, MBL-A eluted corresponding to a M(r) of 850 kDa whereas the majority of MBL-C eluted corresponding to a Mr of 950 kDa. On sucrose density gradient centrifugation the sedimentation velocities of MBL-A and MBL-C were estimated at 7.3 S and 10.8 S, respectively. The MBL-A and MBL-C levels in 10 laboratory mice strains were compared and found to vary between 4 microg/ml to 12 microg/ml, and 16 microg/ml to 118 microg/ml, respectively. After the induction of acute phase responses by intraperitoneal injection of either casein or lipopolysaccharide (LPS), MBL-A was found to increase approximately two-fold, with a maximum after 32 h, while MBL-C did not increase significantly. In comparison, serum amyloid A component (SAA) peaked at 15 h with an approximate 100-fold increase.