Résumé
Retinal pigment epithelial (RPE) is primarily impaired in age-related macular degeneration (AMD), leading to progressive loss of photoreceptors and sometimes choroidal neovascularization (CNV). mTOR has been proposed as a promising therapeutic target, while the usage of its specific inhibitor, rapamycin, was greatly limited. To mediate the mTOR pathway in the retina by a noninvasive approach, we developed novel biomimetic nanocomplexes where rapamycin-loaded nanoparticles were coated with cell membrane derived from macrophages (termed as MRaNPs). Taking advantage of the macrophage-inherited property, intravenous injection of MRaNPs exhibited significantly enhanced accumulation in the CNV lesions, thereby increasing the local concentration of rapamycin. Consequently, MRaNPs effectively downregulated the mTOR pathway and attenuate angiogenesis in the eye. Particularly, MRaNPs also efficiently activated autophagy in the RPE, which was acknowledged to rescue RPE in response to deleterious stimuli. Overall, we design and prepare macrophage-disguised rapamycin nanocarriers and demonstrate the therapeutic advantages of employing biomimetic cell membrane materials for treatment of AMD.
Résumé
Based on the natural affinity between macrophages and atherosclerotic lesions, we made a novel macrophage membrane-coated polylactic acid-glycolic acid copolymer (PLGA) nanoparticle (MPLNPs), and examined its ability targeting atherosclerotic lesions. PLGA nanoparticle (PLGANPs) were prepared by precipitation and MPLNPs were prepared by membrane extrusion. Their morphology, particle size and retainment of functional proteins were characterized. Their targeting capabilities were investigated with cell uptake assay in vitro and fluorescence imaging in vivo. The results showed that MPLNPs were spherical, with obvious core/shell structure, the average particle size was (167 ±6.12) nm, and integrin α4β1 was retained on the surface. Vascular cell adhesion molecule 1 (VCAM-1) receptor was highly expressed in the LPS (lipopolysaccharides)-HUVEC (human umbilical vein endothelial cells) and atherosclerotic lesions in ApoE-/- mouse model, and the nanoparticles could effectively recognize the VCAM-1 receptor and had good targeting properties in vitro and in vivo. The results suggest that the cell membrane biomimetic nano-carrier may provide a new approach for the targeting strategy in the treatment of atherosclerosis and related diseases.
Résumé
Macrophages are involved in many important biological processes and membrane proteins are the key effector molecules for their functions. However, membrane proteins are difficult to analyze by 2-DE based method because of their intrinsic tendency to self-aggregate during the first dimension separation (IEF). To circumvent the obstacle hampering membrane protein analysis, we combined one-dimensional SDS-PAGE with capillary liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using this technique, we identified 458 GO annotated membrane proteins with extremely high confidence, including most known markers of peritoneal macrophages (e.g., CD11b, F4/80, CD14, CD18, CD86, CD44, CD16 and Toll-like receptor). Thirteen other CD antigens and 18 Ras-related small GTPase were also identified. In addition to those known macrophage membrane proteins, a significant number of novel proteins have also been identified. This research provides a valuable data set of macrophage membrane proteins, thus allowing for more comprehensive study of membrane proteins and a better understanding of the function mechanisms of macrophages in many biological processes.
Résumé
Objective:To investigate the expression of membrane cofactor protein (MCP)?decay accelerating factor (DAF) and homologous restriction factor 20 (HRF 20) on the surface of CD16 +monocyte/macrophage (Mo/M?) in the urine of patients with glomerulonephritis(GN) Methods:The expression of MCP?DAF and HRF 20 on the surface of urinary CD16 +Mo/M? were tested by Flow Cytometry and the levels of urinary sC5b 9 by ELISA in 134 patients with GN that were divided into mini change (MC)?glomerulosclerosis (GS)?membranous nephropathy (MN) and proliferative glomerulonephritis (PGN) Results:The expressions of MCP?DAF and HRF 20 on the surface of urinary CD16 +Mo/M? and the levels of urinary sC5b 9 in the patients with GS ?MN or PGN were significantly higher than those in controls (P
Résumé
Macrophages from lepromatous leprosy patients showed poor adherence to Mycobacterium leprae. The phagocytic activity of the macrophages was not correlated to the influence on the adherence ability. Based on the phagocytic behaviour of macrophages from normal individuals and from lepromatous leprosy, patients as well as the action of neuraminidase in reversing the extent of adherence, it is suggested that macrophages from lepromatous leprosy patients differ from those from normal individuals in regard to their surface properties. There was no relationship between the degree of adherence and the concentration of Fc receptors of the macrophages. It was also shown that an extract of lysed macrophages from lepromatous leprosy patient was able to reduce the adherence of Mycobacterium leprae to normal macrophages. This study shows that adherence is a good indicator of the surface property of macrophages which in turn could play an important role in the cell mediated immunity of the patient. The observations suggest altered macrophage membrane structure in the long term-treated, otherwise normal, lepromatous leprosy patients.