Predictive models for cholesterol crystals and plaque vulnerability in acute myocardial infarction: Insights from an optical coherence tomography study.

BACKGROUND: Cholesterol crystals (CCs) are recognized as a risk factor for vulnerable atherosclerotic plaque rupture (PR) and major adverse cardiovascular events. However, their predictive factors and association with plaque vulnerability in patients with acute myocardial infarction (AMI) remain insufficiently explored. Therefore, This study aims to investigate the association between CCs and plaque vulnerability in culprit lesions of AMI patients, identify the factors influencing CCs formation, and develop a predictive model for CCs. METHODS: A total of 431 culprit lesions from AMI patients who underwent pre-intervention optical coherence tomography (OCT) imaging were analyzed. Patients were divided into groups based on the presence or absence of CCs and PR. The relationship between CCs and plaque vulnerability was evaluated. A risk nomogram for predicting CCs was developed using the least absolute shrinkage and selection operator and logistic regression analysis. RESULTS: CCs were identified in 64.5 % of patients with AMI. The presence of CCs was associated with a higher prevalence of vulnerable plaque features, such as thin-cap fibroatheroma (TCFA), PR, macrophage infiltration, neovascularization, calcification, and thrombus, compared to patients without CCs. The CCs model demonstrated an area under the curve (AUC) of 0.676 for predicting PR. Incorporating CCs into the TCFA model (AUC = 0.656) significantly enhanced predictive accuracy, with a net reclassification improvement index of 0.462 (95 % confidence interval [CI]: 0.263-0.661, p < 0.001) and an integrated discrimination improvement index of 0.031 (95 % CI: 0.013-0.048, p = 0.001). Multivariate regression analysis identified the atherogenic index of plasma (odds ratio [OR] = 2.417), TCFA (OR = 1.759), macrophage infiltration (OR = 3.863), neovascularization (OR = 2.697), calcification (OR = 1.860), and thrombus (OR = 2.430) as independent risk factors for CCs formation. The comprehensive model incorporating these factors exhibited reasonable discriminatory ability, with an AUC of 0.766 (95 % CI: 0.717-0.815) in the training set and 0.753 (95 % CI: 0.704-0.802) in the internal validation set, reflecting good calibration. Decision curve analysis suggested that the model has potential clinical utility within a threshold probability range of approximately 18 % to 85 %. CONCLUSIONS: CCs were associated with plaque vulnerability in the culprit lesions of AMI patients. Additionally, this study identified key factors influencing CCs formation and developed a predictive model with potential clinical applicability.

Relationship between stress hyperglycaemic ratio and incidence of in-hospital cardiac arrest in patients with acute coronary syndrome: a retrospective cohort study.

BACKGROUND: The stress hyperglycaemic ratio (SHR), a new marker that reflects the true hyperglycaemic state of patients with acute coronary syndrome (ACS), is strongly associated with adverse clinical outcomes in these patients. Studies on the relationship between the SHR and in-hospital cardiac arrest (IHCA) incidence are limited. This study elucidated the relationship between the SHR and incidence of IHCA in patients with ACS. METHODS: In total, 1,939 patients with ACS who underwent percutaneous coronary intervention (PCI) at the Affiliated Hospital of Zunyi Medical University were included. They were divided into three groups according to the SHR: group T1 (SHR ≤ 0.838, N = 646), group T2 (0.838< SHR ≤ 1.140, N = 646), and group T3 (SHR3 > 1.140, N = 647). The primary endpoint was IHCA incidence. RESULTS: The overall IHCA incidence was 4.1% (N = 80). After adjusting for covariates, SHR was significantly associated with IHCA incidence in patients with ACS who underwent PCI (odds ratio [OR] = 2.6800; 95% confidence interval [CI] = 1.6200-4.4300; p<0.001), and compared with the T1 group, the T3 group had an increased IHCA risk (OR = 2.1800; 95% CI = 1.2100-3.9300; p = 0.0090). In subgroup analyses, after adjusting for covariates, patients with ST-segment elevation myocardial infarction (STEMI) (OR = 3.0700; 95% CI = 1.4100-6.6600; p = 0.0050) and non-STEMI (NSTEMI) (OR = 2.9900; 95% CI = 1.1000-8.1100; p = 0.0310) were at an increased IHCA risk. After adjusting for covariates, IHCA risk was higher in patients with diabetes mellitus (DM) (OR = 2.5900; 95% CI = 1.4200-4.7300; p = 0.0020) and those without DM (non-DM) (OR = 3.3000; 95% CI = 1.2700-8.5800; p = 0.0140); patients with DM in the T3 group had an increased IHCA risk compared with those in the T1 group (OR = 2.4200; 95% CI = 1.0800-5.4300; p = 0.0320). The restriction cubic spline (RCS) analyses revealed a dose-response relationship between IHCA incidence and SHR, with an increased IHCA risk when SHR was higher than 1.773. Adding SHR to the baseline risk model improved the predictive value of IHCA in patients with ACS treated with PCI (net reclassification improvement [NRI]: 0.0734 [0.0058-0.1409], p = 0.0332; integrated discrimination improvement [IDI]: 0.0218 [0.0063-0.0374], p = 0.0060). CONCLUSIONS: In patients with ACS treated with PCI, the SHR was significantly associated with the incidence of IHCA. The SHR may be a useful predictor of the incidence of IHCA in patients with ACS. The addition of the SHR to the baseline risk model had an incremental effect on the predictive value of IHCA in patients with ACS treated with PCI.

Association of the triglyceride glucose-body mass index with the extent of coronary artery disease in patients with acute coronary syndromes.

BACKGROUND: Studies have shown that insulin resistance is strongly associated with the development of cardiovascular disease, and the triglyceride glucose-body mass index (TyG-BMI index) is considered to be a reliable surrogate marker of insulin resistance. There are limited studies on the relationship between TyG-BMI index and the extent of coronary artery disease in patients with acute coronary syndrome (ACS). This study aimed to investigate the relationship between TyG-BMI index and the extent of coronary artery disease in patients with ACS. METHODS: Overall, 2,317 patients with ACS who underwent percutaneous coronary intervention at the Affiliated Hospital of Zunyi Medical University were included in this study. The TyG-BMI index was grouped according to the tertile method. The extent of coronary artery disease in patients with ACS was quantitatively assessed using the SYNTAX score, which was categorised as low (≤ 22), intermediate (23-32), and high risk (≥ 33). RESULTS: In the overall population, multivariate logistic regression analyses showed that TyG-BMI index was associated with mid/high SYNTAX score in patients with ACS (odds ratio [OR] = 1.0041; 95% confidence interval [CI] = 1.0000-1.0079; p = 0.0310). Subgroup analyses showed that TyG-BMI index was an independent risk factor for mid/high SYNTAX score in female ACS patients after adjusting for multiple confounders (OR = 1.0100; 95% CI = 1.0000-1.0200; p = 0.0050), and that the risk of mid/high SYNTAX score was 2.49 times higher in the T3 group (OR = 2.4900; 95% CI = 1.2200-5.0600; p = 0.0120). Restricted cubic spline analysis showed a linear correlation between TyG-BMI index and complex coronary artery disease (SYNTAX score > 22) in women with ACS. In female ACS patients, inclusion of the TyG-BMI index did not improve the predictive power of the underlying risk model (net reclassification improvement: 0.0867 [-0.0256-0.1989], p = 0.1301; integrated discrimination improvement: 0.0183 [0.0038-0.0329], p = 0.0135). CONCLUSIONS: TyG-BMI index is linearly associated with the degree of complex coronary artery disease in female ACS patients. However, the inclusion of the TyG-BMI index did not improve the predictive power of the underlying risk model for female ACS patients.

Association of LDL-C level with neoatherosclerosis and plaque vulnerability in patients with late restenosis: an optical coherence tomography study.

Neoatherosclerosis (NA) is a significant contributor to late stent failure; however, predictors of late in-stent restenosis (ISR) with NA have not been systematically reported. This study aimed to identify predictors of NA incidence and plaque vulnerability in patients with late ISR and the role of low-density lipoprotein cholesterol (LDL-C) levels in this process. A total of 216 patients with 216 lesions who underwent optical coherence tomography (OCT) before interventional procedure for late drug-eluting stent ISR were enrolled and divided into NA and non-NA groups based on OCT findings. Results showed that higher LDL-C levels were associated with NA, thin-cap fibroatheroma (TCFA), intimal disruption, plaque erosion, and thrombosis. Multivariate regression analysis revealed that the LDL-C level was an independent risk factor for NA and TCFA. The LDL-C levels exhibited a significant predictive value for NA and TCFA, surpassing other factors such as stent age and other lipid types. In conclusion, a high LDL-C level is an independent predictor of NA incidence and plaque vulnerability in patients with late ISR.

Matrine regulates H2O2-induced oxidative stress through long non-coding RNA HOTAIR/miR-106b-5p axis via AKT and STAT3 pathways.

Matrine is a main active constituent of Chinese herb Sophora flavescens Ait (Kushen), which has shown various pharmacological effects, and has been reported to exhibit protective effects in heart failure. In the present study, the underlying mechanism of matrine was explored in H2O2-induced H9c2 cell line. It was confirmed that matrine could alleviate H2O2-induced injury in H9c2 cells. And the down-regulation of long non-coding RNA HOTAIR induced by H2O2 could be reversed by treating with matrine. Moreover, overexpression of HOTAIR promoted cell viability and superoxide dismutase (SOD) level, but inhibited cell apoptosis and lactate dehydrogenase (LDH) level. We found that miR-106b-5p was a target of HOTAIR and negatively regulated by HOTAIR. Moreover, up-regulation of miR-106b-5p restored the effects of HOTAIR overexpression on cell viability, apoptosis, and the levels of LDH and SOD. In addition, matrine protected H9c2 cells from H2O2-induced injury through HOTAIR/miR-106b-5p axis. Furthermore, we discovered that matrine exerted protective effects on H2O2-induced H9c2 cells through activating STAT3 and AKT pathway. In brief, matrine modulated H2O2-induced myocardial oxidative stress repair through HOTAIR/miR-106b-5p axis via AKT and STAT3 signaling pathway. Our study may provide a therapeutic target for the therapy of oxidative stress heart diseases.

Exosomes Derived from miR-214-Enriched Bone Marrow-Derived Mesenchymal Stem Cells Regulate Oxidative Damage in Cardiac Stem Cells by Targeting CaMKII.

Cardiac stem cells (CSCs) have emerged as one of the most promising stem cells for cardiac protection. Recently, exosomes from bone marrow-derived mesenchymal stem cells (BMSCs) have been found to facilitate cell proliferation and survival by transporting various bioactive molecules, including microRNAs (miRs). In this study, we found that BMSC-derived exosomes (BMSC-exos) significantly decreased apoptosis rates and reactive oxygen species (ROS) production in CSCs after oxidative stress injury. Moreover, a stronger effect was induced by exosomes collected from BMSCs cultured under hypoxic conditions (Hypoxic-exos) than those collected from BMSCs cultured under normal conditions (Nor-exos). We also observed greater miR-214 enrichment in Hypoxic-exos than in Nor-exos. In addition, a miR-214 inhibitor or mimics added to modulate miR-214 levels in BMSC-exos revealed that exosomes from miR-214-depleted BMSCs partially reversed the effects of hypoxia-induced exosomes on oxidative damage in CSCs. These data further confirmed that miR-214 is the main effector molecule in BMSC-exos that protects CSCs from oxidative damage. miR-214 mimic and inhibitor transfection assays verified that CaMKII is a target gene of miR-214 in CSCs, with exosome-pretreated CSCs exhibiting increased miR-214 levels but decreased CaMKII levels. Therefore, the miR-214/CaMKII axis regulates oxidative stress-related injury in CSCs, such as apoptosis, calcium homeostasis disequilibrium, and excessive ROS accumulation. Collectively, these findings suggest that BMSCs release miR-214-containing exosomes to suppress oxidative stress injury in CSCs through CaMKII silencing.

miR-21 increases c-kit+ cardiac stem cell proliferation in vitro through PTEN/PI3K/Akt signaling.

The low survival rate of cardiac stem cells (CSCs) in the ischemic myocardium is one of the obstacles in ischemic cardiomyopathy cell therapy. The MicroRNA (miR)-21 and one of its target protein, the tensin homolog deleted on chromosome ten (PTEN), contributes to the proliferation of many kinds of tissues and cell types. It is reported that miR-21 promotes proliferation through PTEN/PI3K/Akt pathway, but its effects on c-kit+ CSC remain unclear. The authors hypothesized that miR-21 promotes the proliferation in c-kit + CSC, and evaluated the involvement of PTEN/PI3K/Akt pathway in vitro. miR-21 up-regulation with miR-21 efficiently mimics accelerated cell viability and proliferation in c-kit + CSC, which was evidenced by the CCK-8, EdU and cell cycle analyses. In addition, the over-expression of miR-21 in c-kit + CSCs notably down-regulated the protein expression of PTEN although the mRNA level of PTEN showed little change. Gain-of-function of miR-21 also increased the phosphor-Akt (p-Akt) level. Phen, the selective inhibitor of PTEN, reproduced the pro-proliferation effects of miR-21, while PI3K inhibitor, LY294002, totally attenuated the pro-survival effect of miR-21. These results indicate that miR-21 is efficient in promoting proliferation in c-kit+ CSCs, which is contributed by the PTEN/PI3K/Akt pathway. miR-21 holds the potential to facilitate CSC therapy in ischemic myocardium.

[Impact and related mechanism of exogenous receptor activity modifying protein 1 on calcitonin gene-related peptide modified bone marrow mesenchymal stem cells on the migration of vascular smooth muscle cells in vitro].

OBJECTIVE: To 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. METHODS: The 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. RESULTS: VSMC 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). CONCLUSIONS: CGRP 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.

[Expression of SDF-1/CXCR4 in acute infarct myocardium after implantation of bone marrow mesenchymal stem cells in rats].

OBJECTIVE: To explore the role of stromal cell derived factor-1 (SDF-1)/CXCR4 axis in acute infarct myocardium after an implantation of bone marrow mesenchymal stem cells (MSCs) in rats. METHODS: The animals were anesthetized by an intraperitoneal injection of pentobarbital sodium. Left anterior thoracotomy through 3/4 intercostals region was performed and then left anterior descending coronary arteries were ligated for modeling acute myocardial infarction. The MSCs were injected into the area of acute infarct myocardium after a 10-minute ligation of left anterior descending coronary artery. The different concentration and expression of SDF-1/CXCR4 in the area of acute myocardial infarction and left ventricular function were analyzed. RESULTS: At day 28 post-transplantation, the vascular density in MSCs implant group were significantly higher than that in control group (P<0.05). And left ventricular function in MSCs implant group improved significantly than that in control group too (P<0.05). At the same time, the expressions of SDF-1 and CXCR4 in topical injection sites of infarct myocardium were significantly higher than those in control group (P<0.05). In MSCs implant group, the level of SDF-1/CXCR4 peaked at Day 1 post-transplantation and then it declined. CONCLUSIONS: After the implantation of MSCs into acute infarct myocardium, there is vascular regeneration and the level of SDF-1/CXCR4 increases so that left ventricular function improves. And the mechanism may be due to an up-regulation of SDF-1/CXCR4 axis.

Transplantation of mesenchymal stem cells carrying the human receptor activity-modifying protein 1 gene improves cardiac function and inhibits neointimal proliferation in the carotid angioplasty and myocardial infarction rabbit model.

Although transplanting mesenchymal stem cells (MSCs) can improve cardiac function and contribute to endothelial recovery in a damaged artery, natural MSCs may induce neointimal hyperplasia by directly or indirectly acting on vascular smooth muscle cells (VSMCs). Receptor activity-modifying protein 1 (RAMP1) is the component and the determinant of ligand specificity of calcitonin gene-related peptide (CGRP). It is recently reported that CGRP and its receptor involve the proliferation and the apoptosis in vivo and in vitro, and the exogenous RAMP1 enhances the antiproliferation effect of CGRP in VSMCs. Here, we investigated the effects of MSCs overexpressing the human receptor activity-modifying protein 1 (hRAMP1) on heart function and artery repair in rabbit models of myocardial infarction (MI) reperfusion and carotid artery injury. MSCs transfected with a recombinant adenovirus containing the hRAMP1 gene (EGFP-hRAMP1-MSCs) were injected into the rabbit models via the ear vein at 24 h after carotid artery injury and MI 7 days post-EGFP-hRAMP1-MSC transplantation. The cells that expressed both enhance green fluorescent protein (EGFP) and CD31 were detected in the neointima of the damaged artery via immunofluorescence. EGFP-hRAMP1 expression was observed in the injured artery and infarcted myocardium by western blot analysis, confirming that the engineered MSCs targeted the injured artery and infarcted myocardium and expressed hRAMP1 protein. Compared with the EGFP-MSCs group, the EGFP-hRAMP1-MSCs group had a significantly smaller infarcted area and improved cardiac function by 28 days after cell transplantation, as detected by triphenyltetrazolium chloride staining and echocardiography. Additionally, arterial hematoxylin-eosin staining revealed that the area of the neointima and the area ratio of intima/media were significantly decreased in the EGFP-hRAMP1-MSCs group. An immunohistological study showed that the expression of α-smooth muscle antigen and proliferating cell nuclear antigen in the neointima cells of the carotid artery of the EGFP-hRAMP1-MSCs group was approximately 50% lower than that of the EGFP-MSCs group, suggesting that hRAMP1 expression may inhibit VSMCs proliferation within the neointima. Therefore, compared with natural MSCs, EGFP-hRAMP1-engineered MSCs improved infarcted heart function and endothelial recovery from artery injury more efficiently, which will provide valuable information for the development of MSC-based therapy.

[Effects of hRAMP1 modified mesenchymal stem cells on restenosis and heart function in rabbit model of carotid angioplasty and myocardial infarction].

OBJECTIVE: To observe the effects of mesenchymal stem cells (MSC) modified by human receptor activity-modifying protein 1 (hRAMP1) on restenosis and cardiac function post-myocardial infarction (MI) and explore the therapeutic safety for gene modification of MSC. METHODS: The double-injury rabbit model with MI reperfusion and sacculus damaged atherosclerotic carotid were established according to the previous study. MSC were transfected with adenovirus vector with enhanced green fluorescence protein (EGFP) and then introduced into rabbit model. The animals were randomly divided into Ad-EGFP-hRAMP1-MSC transfection group (hRAMP1-MSC group, n = 24) and Ad-EGFP-MSC transfection group (MSC group, n = 24), and PBS transfection group (C group, n = 24). At Day 28 post-transplantation, the injured carotid arteries and infarction myocardium were harvested to detect the expression of EGFP-positive MSC and assess organization morphology by hematoxylin and eosin, triphenyltetrazolium chloride or immunohistochemical stains and heart function by echocardiography. RESULTS: On flow cytometry, most cells expressed CD29 and CD90 while few ones expressed CD45. MSC with EGFP and a continuous expression of CD31 were found in intima of damaged carotid of both hRAMP1-MSC and MSC, but the expression of EGFP was not found in the control group. At Day 28 post-transplantation, the improvement of heart function and the decrease of infarct size were found in the hRAMP1-MSC and MSC groups compared with that in the control group(EF: 60.6% ± 1.5%,50.8% ± 3.2% vs 38.2% ± 2.0%, infarct size: 20.7% ± 1.4%, 33.2% ± 3.7% vs 35.6% ± 2.7%, all P < 0.05), especially much higher in hRAMP1-MSC group. At Day 28 post-transplantation, the area of intima hyperplasia and the rate of neointima and media in the hRAMP1-MSC group were lower than those in the MSC and C groups (0.15 ± 0.05 and 0.33 ± 0.08 vs 0.77 ± 0.11, 0.24 ± 0.07 and 0.51 ± 0.11 vs 1.09 ± 0.23, all P < 0.05). Also the expression of α-SMA was found in the hyperplasia intima. The expression of proliferating cell nuclear antigen significantly decreased in the hRAMP1-MSC group than those of the MSC and control groups (0.120 ± 0.028 vs 0.366 ± 0.013 and 0.627 ± 0.049, both P < 0.05). And it was much lower in the MSC group than that in the control group. CONCLUSIONS: Compared with MSC alone, hRAMP1-modified MSC have the potency not only of more improvement on cardiac function and the recovery of damaged endothelium, but also of significant inhibition of the proliferation of vascular smooth muscle cells. The recombinant hRAMP1 adenovirus vectors do not affect the differentiation potential MSC into endothelial cells.

[Establishing an animal model for carotid artery stenosis in rabbits].

OBJECTIVE: To establish an animal model for carotid artery stenosis in rabbits. METHODS: Forty New Zealand White rabbits were randomly divided into two groups, for 4-week and 8-week experiment, respectively. All rabbits were fed with a diet with 1.5% cholesterol for one week before the experiment started. The right common carotid arteries (RCCA) of the rabbits were then injured with nitrogen gas (100 mL/min x 5 min), with the left common carotid arteries (LCCA) serving as a control (self control). An additional 5 rabbits were fed with high cholesterol diet only without exposure to nitrogen gas (control group). Angiography and pathology tests were performed to evaluate the stenosis of carotid arteries. RESULTS: Four weeks after exposure to nitrogen gas, early atheromatosis appeared, with lesions showing fatty streak and fibrous plaque, and thickened focal arterial walls. The lumens showed light-stenosis. The angiography showed 20%-30% artery stenosis. Eight weeks after exposure to nitrogen gas, the lesions proceeded to mature fibrous plaque or atheromatous plaque stages, with entire arterial walls thickened and remarkable lumens stenosis. The angiography showed 60% -80% artery stenosis, and two arteries were totally occluded. No artherosclerosis and stenosis were seen in the self control arteries and control groups. CONCLUSION: The animal model for carotid artery stenosis can be effectively established in rabbits with nitrogen gas injury along with high cholesterol-feeding.

[rhG-CSF promotes re-endothelialization and attenuates intima hyperplasia in carotid artery of rabbits post balloon catheter injury].

OBJECTIVE: To investigate the effect of rhG-CSF on mobilizing bone marrow-MSCs, re-endothelialization and intima hyperplasia in carotid artery of rabbits post balloon catheter injury. METHODS: Rabbits were treated with rhG-CSF (25 microg/kg, twice daily, i.p, n = 35) or saline (n = 32) for 5 days, then, carotid arteries of rabbits were injured by balloon catheter. The number of peripheral MSCs was detected with FACS. The morphology of injured artery was examined with hematoxylin and eosin stain, PCNA was determined with immunohistochemistry. RESULTS: (1) Number of peripheral MSCs was similar at baseline and significantly increased at 24 hours and peaked at 7 days and remained increased till 14 days post rhG-CSF. (2) Significant endothelial cell deletion was evidenced in the control group, while scatter endothelial cells was observed in the rhG-CSF group at 1 week post injury. Two weeks after injury, new endothelial area was significantly higher in rhG-CSF group compared to control group. At 4 weeks post injury, endothelial connection was evidenced and regularly displayed in rhG-CSF treated group. (3) PCNA-positive cells in the tunica intima were significantly lower in rhG-CSF treated rabbits at 7, 14 and 28 days compared that in control rabbits (all P < 0.01). CONCLUSION: rhG-CSF could mobilize the bone marrow-MSCs and promote re-endothelialization and attenuate intima hyperplasia post balloon catheter injury in carotid arteries of rabbits.