Monocyte chemotactic protein 1 increases homing of mesenchymal stem cell to injured myocardium and neovascularization following myocardial infarction

Objective：To investigate the effect of MCP-1 on mesenchymal stem cells（MSCs） homing to injured myocardium in a rat myocardial infarction（MI） model. Methods：Rat myocardial infarction model was established by permanent left anterior descending branch ligation. Mesenchymal stem cells from donor rats were cultured in IMDM and labeled with BrdU. The Rats were divided into two groups. Monocyte chemotactic protein I（MCP-1） expression were measured by in situ hybridization and immunohistochemistry in the sham operated or infarcted hearts at 1, 2, 4, 7, 14 and 28 days post operation in MCP-1 detection group. The rats were injected with MCP-1, anti-MCP-1 antibody or saline 4 days after myocardial infarction in intervention group. Then, a total of 5 × 10^6 cells in 2.5 ml of PBS were injected through the tail vein. The number of the labeled MSCs in the infarcted hearts was counted 3 days post injection. Cardiac function and blood vessel density were assessed 28 days post injection. Results：Self-generating MCP-1 expression was increased at the first day, peaked at the 7^th day and decreased thereafter post MI and remained unchanged in sham operated hearts. The MSCs enrichment in the host hearts were more abundant in the MI groups than that in the non-MI group（P= 0.000）, the MSCs enrichment in the host hearts were more abundant in the MCP-1 injected group than that in the anti-MCP-1 antibody and saline injected groups （P = 0.000）. Cardiac function was improved more in MCP-1 injected group than anti-MCP-1 antibody and saline injected groups（P= 0.000）. Neovascularization in MCP-1 injected group significantly increased compared with that of other groups（P = 0.000）. Conclusion： Myocardial MCP-1 expression was increased only in the early phase post MI. MCP-1 may enhance MSCs homing to the injured heart and improve cardiac function by promoting neovascularization.

Monocyte chemotactic protein-inducing protein 1 negatively regulating asthmatic airway inflammation and mucus hypersecretion involvingγ-aminobutyric acid type A receptor signaling pathway in vivo and in vitro

Background:Mounting evidence,consistent with our previous study,showed thatγ-aminobutyric acid type A receptor(GABAAR)played an indispensable role in airway inflammation and mucus hypersecretion in asthma.Monocyte chemotactic protein-inducing protein 1(MCPIP1)was a key negative regulator of inflammation.Recent studies showed that inflammation was largely suppressed by enhanced MCPIP1 expression in many inflammatory diseases.However,the role and potential mechanism of MCPIP1 in airway inflammation and mucus hypersecretion in asthma were still not well studied.This study was to explore the role of MCPIP1 in asthmatic airway inflammation and mucus hypersecretion in both mice and BEAS-2B cells,and its potential mechanism.Methods:In vivo,mice were sensitized and challenged by ovalbumin(OVA)to induce asthma.Airway inflammation and mucus secretion were analyzed.In vitro,BEAS-2B cells were chosen.Interleukin(IL)-13 was used to stimulate inflammation and mucus hypersecretion in cells.MCPIP1 Lentiviral vector(LA-MCPIP1)and plasmid-MCPIP1 were used to up-regulate MCPIP1 in lung and cells,respectively.MCP-1,thymic stromal lymphopoietin(TSLP),mucin 5AC(MUC5AC),MCPIP1,and GABAARβ2 expressions were measured in both lung and BEAS-2B cells.Immunofluorescence staining was performed to observe the expression of GABAARβ2 in cells.Results:MCPIP1 was up-regulated by LA-MCPIP1(P<0.001)and plasmid-MCPIP1(P<0.001)in lung and cells,respectively.OVA-induced airway inflammation and mucus hypersecretion,OVA-enhanced MCP-1,TSLP,MUC5AC,and GABAARβ2 expressions,and OVA-reduced MCPIP1 were significantly blunted by LA-MCPIP1 in mice(all P<0.001).IL-13-enhanced MCP-1,TSLP,MUC5AC,and GABAARβ2 expressions,and IL-13-reduced MCPIP1 were markedly abrogated by plasmid-MCPIP1 in BEAS-2B cells(all P<0.001).Conclusion:The results of this study suggested that OVA and IL-13-induced airway inflammation and mucus hypersecretion were negatively regulated by MCPIP1 in both lung and BEAS-2B cells,involving GABAAR signaling pathway.

Inhibitory effect of CCR3 signal on alkali-induced corneal neovascularization

AIM: To investigate the effect of CC chemokine receptor 3 (CCR3) signal on corneal neovascularization (CRNV) induced by alkali burn and to explore its mechanism. METHODS: Specific pathogen-free male BALB/C mice (aged 6-8 weeks) were randomly divided into CCR3-antagonist treated group (experimental group) and control group. CRNV was induced by alkali burn in mice. The time kinetic CCR3 expression in injured corneas was examined by reverse transcription polymerase chain reaction (RT-PCR). CCR3-antagonist (SB-328437 at different concentration of 125 mu g/mL, 250 mu g/mL, and 500 mu g/mL) was locally administrated after alkali injury. The formation of CRNV was assessed by CD31 corneal whole mount staining at two weeks after injury. Monocyte chemotactic protein 1 (MCP-1), monocyte chemotactic protein 3 (MCP-3) expressions in the early phase after injury were quantified and compared by RT-PCR. Macrophage intracorneal accumulation in the early phase after injury was evaluated and compared by immunohistochemistry. RESULTS: Alkali injury induced the time kinetic intracorneal CCR3 expression. 500 mu g/mL of CCR3-antagonist treatment in the early phase but not the late phase resulted in significant impaired CRNV as compared to control group (P <0.05). CCR3-antagonist treatment in the early phase significantly reduced the intracorneal MCP-1 and MCP-3 enhancement compare to control group at day 2 and day 4 (P <0.05). Moreover, the number of intracorneal macrophage infiltration in the experimental group was reduced than those in control group at day 4 (P <0.05). CONCLUSION: CCR3 signal is involved in alkali-induced CRNV. CCR3-antagonist can inhibit alkali-induced CRNV by reducing the intracorneal MCP-1 and MCP-3 mRNA expression and the intracorneal macrophage infiltration.