OBJECTIVEReceptor activity-modifying proteins (RAMPs) determine the ligand specificity of the calcitonin receptor-like receptor (CRLR); co-expression of RAMP1 and CRLR results in a calcitonin gene related peptide (CGRP) receptor, whereas the association of RAMP2 or RAMP3 with CRLR gives an adrenomedullin(ADM) receptor. As CGRP and ADM may play a beneficial role in heart failure, this study aimed at the question whether RAMPs mRNAs are changed in heart failure.

METHODSSemi-quantitative reverse transcription-PCR (RT-PCR) was used to detect and quantify the mRNAs of RAMP1 and RAMP3 in the atria of heart failing patients.

RESULTSIt was found that the expressions of RAMP1, RAMP2 and RAMP3 mRNAs increased with the worsening of heart function, but the expressions of RAMP1 and RAMP2 mRNA decreased at level IV of heart failure.

CONCLUSIONThe above results demonstrated in the atria of heart failure patients an up-regulation of CGRP receptor by an increase of RAMP1 in association with CRLR and an up-regulation of ADM receptor by an increase of RAMP2 expression in association with CRLR, thus suggesting that CGRP and ADM receptors be playing a functional role in compensating the chronic heart failure in human.

Adult ; Calcitonin Receptor-Like Protein ; Female ; Heart Atria ; metabolism ; Heart Failure ; genetics ; physiopathology ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; physiology ; Male ; Membrane Proteins ; genetics ; physiology ; Receptor Activity-Modifying Protein 1 ; Receptor Activity-Modifying Protein 2 ; Receptor Activity-Modifying Protein 3 ; Receptor Activity-Modifying Proteins ; Receptors, Adrenomedullin ; Receptors, Calcitonin ; genetics ; physiology ; Receptors, Calcitonin Gene-Related Peptide ; genetics ; physiology ; Receptors, Peptide ; genetics ; physiology ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the impact of calcitonin gene-related peptide (CGRP) modified bone marrow mesenchymal stem cell (MSC) on the migration of vascular smooth muscle cell (VSMC) and related mechanisms.

METHODSThe MSC and VSMC were isolated from rats and cultured, CGRP was transfected to MSC with the high expression lentivirus vector, VSMC was transfected with high expression lentivirus vector of receptor activity modifying protein 1 (RAMP1) and the silence expression lentivirus vector of RAMP1. Then MSC was co-cultured with VSMC. Experimental groups were as follows: (1) Ang II group (MSC + VSMC + Ang II); (2) MSC(CGRP+) group (MSC(CGRP+) + VSMC + Ang II); (3) MSC(CGRP+) RAMP1(-) group (MSC(CGRP+) + VSMC(RAMP1-) + Ang II); (4) MSC(CGRP+) RAMP1(+) group (MSC(CGRP+) + VSMC(RAMP1+) + Ang II); (5) RAMP1(+) group (MSC + VSMC(RAMP1+) + Ang II). Transwell assay was applied to detect the migration of smooth muscle cells, Western blot was applied to detect the protein expression of cells in various groups.

RESULTSVSMC migration number was significantly lower in MSC(CGRP+) group compared with Ang II group (50.8 ± 2.6 vs. 71.4 ± 2.3, P < 0.05), but higher than in MSC(CGRP+) RAMP1(+) group (50.8 ± 2.6 vs. 30.4 ± 3.0, P < 0.05). When RAMP1 expression reduced in VSMC, compared with MSC(CGRP+) RAMP1(+) group, VSMC migration increased in the MSC(CGRP+) RAMP1(-) group compared to MSC(CGRP+)RAMP1(+) (69.0 ± 5.6 vs. 30.4 ± 3.0, P < 0.05) and was similar to Ang II group (69.0 ± 5.6 vs. 71.4 ± 2.3, P > 0.05) and RAMP1(+) group (71.6 ± 3.4). According to the result of Western blot, P-P65 protein expression in MSC(CGRP+) group was lower than that in Ang II group (0.475 ± 0.022 vs.0.642 ± 0.035, P < 0.05). P-P65 protein expression in MSC(CGRP+)RAMP1(-) group was higher than that in MSC(CGRP+) RAMP1(+) group (0.670 ± 0.030 vs. 0.373 ± 0.041, P < 0.05), and there was no difference between MSC(CGRP+)RAMP1(-) group and Ang II group (P > 0.05). P-P65 protein expression was similar between RAMP1(+) group (0.643 ± 0.039) and Ang II group (P > 0.05).

CONCLUSIONSCGRP inhibits VSMC migration through RAMP1. NF-κB and RAMP1 play crucial role in the inhibiting effects of CGRP on VSMC migration. Thus, RAMP1-CGRP signaling inhibits VSMC migration through NF-κB signal pathways.

Animals ; Bone Marrow Cells ; Calcitonin Gene-Related Peptide ; Cell Movement ; Coculture Techniques ; Hematopoietic Stem Cells ; In Vitro Techniques ; Muscle, Smooth, Vascular ; Myocytes, Smooth Muscle ; NF-kappa B ; Rats ; Receptor Activity-Modifying Protein 1 ; Signal Transduction ; Transfection

OBJECTIVETo investigate the effect of mesenchymal stem cells (MSCs) overexpressing human receptor activity modified protein 1 (hRAMP1) by adenovirus vector on infarction related inflammation and cardiac repair in a rabbit model of myocardial infarction (MI).

METHODSThirty rabbits underwent coronary artery ligation for 60 minutes followed by 24 hours reperfusion and divided into MSC(hRAMP1) group (intravenously injection of MSCs transfected with adenovirus vector encoding hRAMP1 gene enhanced green fluorescent protein, EGFP, n = 10), MSC(null) group (MSCs transfected with adenovirus vector encoding only EGFP without hRAMP1 gene, n = 10) and control group (equally volume of phosphate buffered saline, PBS, n = 10). The plasma level of tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were quantified by ELISA assay at before and 1, 3, 7, 28 days after induction of MI. The expression of nuclear factor-κB (NF-κB) and hRAMP1 in infracted myocardium were measured by Western blot at 1, 3, 7, 28 day following MI. The area of MI and collagen deposition and fibrosis were evaluated by TTC staining and Masson staining, respectively.

RESULTSArea of MI and collagen content were significantly reduced in MSC(hRAMP1) group compared those in MSC(null) and control group [(10.1 ± 2.9)% vs. (30.6 ± 2.7)% and (22.5 ± 3.2)%, P < 0.05]. Myocardial expression of NF-κB and plasma TNF-α[7 days after transplantation: (97.2 ± 6.7) pg/ml vs. (207.6 ± 12.7) pg/ml and (153.2 ± 9.9) pg/ml, P < 0.05] were also lower while plasma level of IL-10 [7 days after transplantation: (238.5 ± 17.5) pg/ml vs. (177.3 ± 19.8) pg/ml and (244.6 ± 27.3) pg/ml, P < 0.05] was significantly higher in MSC(hRAMP1) group than in MSC(null) and control group.

CONCLUSIONMSCs overexpression hRAMP1 could further reduce area of MI possibly through inhibiting the myocardial expression of NF-κB and reducing the plasma TNF-α level and raising plasma IL-10 level.

Amino Acid Motifs ; Animals ; Genetic Vectors ; Humans ; Inflammation ; metabolism ; Interleukin-10 ; blood ; Male ; Mesenchymal Stem Cell Transplantation ; methods ; Myocardial Infarction ; metabolism ; pathology ; surgery ; Myocardium ; metabolism ; Rabbits ; Receptor Activity-Modifying Protein 1 ; genetics ; Tumor Necrosis Factor-alpha ; blood

OBJECTIVETo investigate the influnce of receptor activity modifying protein 1(RAMP-1) overexpression on enhancing effect of calcitonin gene-related peptide on MG-63 cells proliferation.

METHODSCultured MG-63 osteoblasts in exponential phase of growth were randomly divided into three groups: RAMP-1 overexpression group, empty vector control group and negative control group. RAMP-1 eukaryotic expression vector was constructed and stably transfected into MG-63 cells. Realtime-polymerase chain reaction, Western blotting and immunofluroescence were used respectively to detect the expression of calcitonin receptor-like receptor (CRLR) in the cells and its distribution on cell membrane. The status of proliferation was detected respectively at 0, 24, 48, 72, 96 h by cell counting kit-8 (CCK-8) and cells were collected to analyze their cycle respectively at 0, 8, 16, 24 h by flow cytometry.

RESULTSCRLR protein and mRNA expression levels of MG-63 cells in RAMP-1 overexpression group were significantly higher than the other two groups (P < 0.05). The A value of RAMP-1 overexpression group at 24, 48, 72, 96 h were 0.628 ± 0.175, 0.896 ± 0.592, 1.055 ± 0.004, 1.179 ± 0.618, respectively, which were significantly higher than that of the other two groups (P < 0.05). The difference was most pronounced at 72 h. S-phase fraction of RAMP-1 overexpression group was (1.25 ± 0.13)%, (68.79 ± 0.56)%, (64.49 ± 1.59)%, (57.82 ± 0.75)%, respectively, which were significantly higher than the other two groups (P < 0.05). The difference was most pronounced at 8 h.

CONCLUSIONSRAMP-1 overexpression can promote CRLR distribution on MG-63 cell membrane and enhance CGRP's promotion effect on MG-63 cell proliferation.

Bone Neoplasms ; metabolism ; pathology ; Calcitonin Gene-Related Peptide ; genetics ; metabolism ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Genetic Vectors ; Humans ; Osteosarcoma ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Random Allocation ; Receptor Activity-Modifying Protein 1 ; genetics ; metabolism ; Transfection