Silencing DOCK2 Attenuates Cardiac Fibrosis Following Myocardial Infarction in Mice Via Targeting PI3K/Akt and Wnt/ß-Catenin Pathways.

Cardiac fibrosis following myocardial infarction (MI) seriously affects the prognosis and survival rate of patients. This study aimed to determine the effect and regulation mechanism of the dedicator of cytokinesis 2 (DOCK2) during this process. Experiments were carried out in mice in vivo, and in Ang II treated cardiac fibroblasts (CFs) in vitro. DOCK2 was increased in mouse myocardial tissues after MI and Ang II-treated CFs. In MI mice, DOCK2 silencing improved cardiac function, and ameliorated cardiac fibrosis. DOCK2 knockdown suppressed the activation of CFs and decreased the expression of α-SMA, collagen I, and collagen III. Suppression of DOCK2 mitigated Ang II induced migration of CFs. DOCK2 inhibition reduced the activity of the PI3K/Akt and Wnt/ß-catenin pathways, while this change could be reversed by the pathway activators, SC79 and SKL2001. In summary, DOCK2 suppression improves cardiac dysfunction and attenuates cardiac fibrosis after MI via attenuating PI3K/Akt and Wnt/ß-catenin pathways.

Predictive value of atherogenic index of plasma and atherogenic index of plasma combined with low-density lipoprotein cholesterol for the risk of acute myocardial infarction.

Background and aims: Acute myocardial infarction (AMI) is a prevalent medical condition associated with significant morbidity and mortality rates. The principal underlying factor leading to myocardial infarction is atherosclerosis, with dyslipidemia being a key risk factor. Nonetheless, relying solely on a single lipid level is insufficient for accurately predicting the onset and progression of AMI. The present investigation aims to assess established clinical indicators in China, to identify practical, precise, and effective tools for predicting AMI. Methods: The study enrolled 267 patients diagnosed with acute myocardial infarction as the experimental group, while the control group consisted of 73 hospitalized patients with normal coronary angiography. The investigators collected general clinical data and relevant laboratory test results and computed the Atherogenic Index of Plasma (AIP) for each participant. Using acute myocardial infarction status as the dependent variable and controlling for confounding factors such as smoking history, fasting plasma glucose (FPG), low-density lipoprotein cholesterol (LDL-C), blood pressure at admission, and diabetes history, the researchers conducted multivariate logistic regression analysis with AIP as an independent variable. Receiver operating characteristic (ROC) curves were employed to determine the predictive value of AIP and AIP combined with LDL-C for acute myocardial infarction. Result: The results of the multivariate logistic regression analysis indicated that the AIP was an independent predictor of acute myocardial infarction. The optimal cut-off value for AIP to predict AMI was -0.06142, with a sensitivity of 81.3%, a specificity of 65.8%, and an area under the curve (AUC) of 0.801 (95% confidence interval [CI]: 0.743-0.859, P < 0.001). When AIP was combined with LDL-C, the best cut-off value for predicting acute myocardial infarction was 0.756107, with a sensitivity of 79%, a specificity of 74%, and an AUC of 0.819 (95% CI: 0.759-0.879, P < 0.001). Conclusions: The AIP is considered an autonomous determinant of risk for AMI. Utilizing the AIP index alone, as well as in conjunction with LDL-C, can serve as effective predictors of AMI.

LncRNA HOXA11-AS promotes vascular endothelial cell injury in atherosclerosis by regulating the miR-515-5p/ROCK1 axis.

AIMS: Long non-coding RNA HOXA11-AS participated in heart disease. In this study, we aim to evaluate the potential roles of HOXA11-AS in atherosclerosis and its underlying mechanisms. METHODS AND RESULTS: The expression levels of HOXA11-AS in ox-LDL-treated HUVECs and arch tissues of high-fat diet-fed ApoE-/- mice (n = 10) were assessed by qRT-PCR. The effects of HOXA11-AS knockdown on the development of atherosclerosis were evaluated using in vitro and in vivo models. Luciferase reporter and RNA immunoprecipitation (RIP) assays verified the potential relationships between HOXA11-AS or ROCK1 and miR-515-5p. The interactive roles between HOXA11-AS and miR-515-5p and between miR-515-5p and ROCK1 were further characterized in ox-LDL-treated HUVECs. Our data showed that HOXA11-AS was significantly up-regulated (P < 0.001), whereas miR-515-5p was dramatically down-regulated in AS mice tissues (P < 0.001) and ox-LDL-treated HUVECs (P < 0.01). Ox-LDL could induce endothelial injuries by inhibiting cell proliferation (P < 0.001) and SOD synthesis (P < 0.001), promoting apoptosis (P < 0.01), ROS (P < 0.001), and MDA production (P < 0.001), increasing Bax (P < 0.001) and cleaved Caspase-3 (P < 0.001), and decreasing Bcl-2 (P < 0.001) and phosphorylated eNOS (P < 0.01). HOXA11-AS knockdown attenuated endothelial injuries via increasing eNOS phosphorylation. Luciferase assay and RIP results confirmed that miR-515-5p is directly bound to HOXA11-AS and ROCK1. HOXA11-AS promoted ox-LDL-induced HUVECs injury by directly inhibiting miR-515-5p from increasing ROCK1 expression and subsequently decreasing the expression and phosphorylation of eNOS. MiR-515-5p mimics could partially reverse the effects of HOXA11-AS knockdown. CONCLUSIONS: HOXA11-AS contributed to atherosclerotic injuries by directly regulating the miR-515-5p/ROCK1 axis. This study provided new evidence that HOXA11-AS might be a candidate for atherosclerosis therapy.

LncRNA LINC00461 exacerbates myocardial ischemia-reperfusion injury via microRNA-185-3p/Myd88.

OBJECTIVE: Long non-coding RNAs (lncRNAs) play critically in the pathogenesis of myocardial ischemia-reperfusion (I/R) injury. Thus, it was proposed to investigate the mechanism of LINC00461 in the disease through mediating microRNA-185-3p (miR-185-3p)/myeloid differentiation primary response gene 88 (Myd88) axis. METHODS: miR-185-3p, LINC00461 and Myd88 expression in mice with I/R injury was measured. Mice with I/R injury were injected with the gene expression-modified vectors, after which cardiac function, hemodynamics, myocardial enzyme, oxidative stress, and cardiomyocyte apoptosis were analyzed. RESULTS: I/R mice showed LINC00461 and Myd88 up-regulation and miR-185-3p down-regulation. Down-regulating LINC00461 or up-regulating miR-185-3p recovered cardiac function, reduced myocardial enzyme levels, and attenuated oxidative stress and cardiomyocyte apoptosis in mice with I/R. miR-185-3p overexpression rescued the promoting effect of LINC00461 upregulation on myocardial injury in I/R mice. CONCLUSION: LINC00461 knockdown attenuates myocardial I/R injury via elevating miR-185-3p expression to suppress Myd88 expression.

Calcium and integrin binding protein 1 (CIB1) induces myocardial fibrosis in myocardial infarction via regulating the PI3K/Akt pathway.

Myocardial infarction (MI) is a severe coronary artery disease resulted from substantial and sustained ischemia. Abnormal upregulation of calcium and integrin binding protein 1 (CIB1) has been found in several cardiovascular diseases. In this study, we established a mouse model of MI by permanent ligation of the left anterior descending coronary artery. CIB1 was upregulated in the heart of MI mice. Notably, CIB1 knockdown by intramuscular injection of lentivirus-mediated short hairpin RNA (shRNA) targeting Cib1 improved cardiac function and attenuated myocardial hypertrophy and infarct area in MI mice. MI-induced upregulation of α-SMA, vimentin, Collagen I, and Collagen III, which resulted in collagen production and myocardial fibrosis, were regressed by CIB1 silencing. In vitro, cardiac fibroblasts (CFs) isolated from mice were subjected to angiotensin II (Ang II) treatment. Inhibition of CIB1 downregulated the expression of α-SMA, vimentin, Collagen I, and Collagen III in Ang II-treated CFs. Moreover, CIB1 knockdown inhibited Ang II-induced phosphorylation of PI3K-p85 and Akt in CFs. The effect of CIB1 knockdown on Ang II-induced cellular injury was comparable to that of LY294002, a specific inhibitor of the PI3K/Akt pathway. We demonstrated that MI-induced cardiac hypertrophy, myocardial fibrosis, and cardiac dysfunction might be attributed to the upregulation of CIB1 in MI mice. Downregulation of CIB1 alleviated myocardial fibrosis and cardiac dysfunction by decreasing the expression of α-SMA, vimentin, Collagen I, and Collagen III via inhibiting the PI3K/Akt pathway. Therefore, CIB1 may be a potential target for MI treatment.

Follow-up study of depressive state on patients with atrial fibrillation 1 year after radio-frequency ablation.

Objective: To analyze the effect of depression on the recurrence of atrial fibrillation (AF) 1 year after radio-frequency ablation. Methods: A total of 91 patients with AF admitted to our hospital from January 2020 to July 2021 were studied. All patients were followed up 1 year after radio-frequency ablation. A total of 91 subjects were divided into recurrence group (n = 30) and no recurrence group (n = 61) according to the recurrence situation 1 year after radio-frequency ablation. Age, disease course, body mass index (BMI), gender, echocardiography (left atrial diameter), blood inflammatory indicators (neutrophil count, lymphocyte count, and monocyte count), and Self-rating Depression Scale (SDS) scores were compared between the two groups. Logistic multivariate regression analysis was used to analyze the effect of SDS score and other indexes on the recurrence of AF 1 year after radio-frequency ablation. Results: The age of patients in relapse group was higher than that in no relapse group (P < 0.05) and the course of disease was longer than that of the no recurrence group (P < 0.05). The BMI was higher than that of the no recurrence group (P < 0.05) and the left atrial diameter was greater than that of the no recurrence group (P < 0.05). Neutrophil count and monocyte count were significantly higher than those in no recurrence group (P < 0.05) and the lymphocyte count was significantly lower than that in the no recurrence group (P < 0.05). There were significant differences in SDS score composition between the two groups (P < 0.05) and the composition ratio of patients with moderate and major depression in the relapsing group was significantly higher than that in the non-relapsing group. The composition ratio of patients without depression in the relapsing group was significantly lower than that in the non-relapsing group. Multivariate analysis showed that age, disease course, BMI, left atrial diameter, neutrophil count, lymphocyte count, monocyte count, and SDS score were all independent factors affecting the recurrence of AF patients 1 year after radio frequency ablation (P < 0.05). Compared with patients without depression, patients with mild, moderate and major depression had an increased risk of recurrence by 74.0, 98.2, and 151.2% 1 year after radio-frequency ablation, respectively (OR = 1.740, 1.982, and 2.512). Conclusion: There is a high rate of depression in patients with AF. Depression is an important factor affecting the early recurrence of patients with AF after radio-frequency ablation.

Ultrasound molecular imaging of arterial thrombi with novel microbubbles modified by cyclic RGD in vitro and in vivo.

Despite immense potential, ultrasound molecular imaging (UMI) of arterial thrombi remains very challenging because the high-shear arterial flow limits binding of site-targeted microbubbles to the thrombi. The linear Arg-Gly-Asp (RGD) peptides have been successfully applied to evaluate venous, atrial, and arteriolar thrombi, but have thus far failed in the detection of arterial thrombi. Cyclic RGD (Arg-Gly-Asp-D-Phe-Cys) is a cyclic conformation of linear RGD peptides, which has much higher binding-affinity and selectivity for binding to the glycoprotein (GP) IIb/IIIa receptor than its linear counterpart and thus is likely to be an optimal targeted molecular probe for ultrasound molecular imaging of arterial thrombi. In this study, we sought to assess the feasibility of a novel microbubble conjugated with cyclic RGD (Mb-cyclic RGD) in UMI of arterial thrombi in vitro and in vivo . As expected, Mb-cyclic RGD had greater GP IIb/IIIa-targeted binding capability in all shear stress conditions. In addition, the shear stress at half-maximal detachment of Mb-cyclic RGD was 5.7-fold higher than that of microbubbles with non-specific peptide (Mb-CON) (p<0.05). Mb-cyclic RGD enhanced the echogenicity of the platelet-rich thrombus in vitro whereas Mb-CON did not produce enhancement. In the in vivo setting, optimal signal enhancement of the abdominal aortic thrombus was displayed with Mb-cyclic RGD in all cases. Mean video intensity of the abdominal aortic thrombi with Mb-cyclic RGD was 3.2-fold higher than that with Mb-CON (p<0.05). The novel Mb-cyclic RGD facilitated excellent visualisation of arterial thrombi using UMI and showed great promise for clinical applications.

[Evaluation of tumor angiogenesis using microbubbles conjugated with RGD peptides and contrast enhanced ultrasound].

OBJECTIVE: To assess the feasibility of usage of microbubbles conjugated with RGD peptides and contrast enhanced ultrasound (CEU) in detection of tumor angiogenesis. METHODS: Lipid microbubbles (MB) were prepared, and the RGD peptides were covalently conjugated to the lipid shell of MB (MB(RGD)). Six nude mice with tumor created by dorsal inoculation of HepG2 tumor cells were used as the test group. Six nude mice without tumor were served as the control group. 10 minutes after bolus injection of MB and MB(RGD) randomly (30 min interval) via a tail vein catheter, CEU was performed on the tumors of the test group and the thigh skeletal muscles of control group. The video intensity (VI) of tumors and the skeletal muscles were measured. The tumors and the skeletal muscles were harvested for immunohistochemical examination. RESULTS: Only a slight contrast enhancement of the tumor was seen with MB, and the VI was 5.33 ± 1.71. While a remarkable enhancement of the tumor was observed after injection of MB(RGD). The VI was up to 17.03 ± 3.58, 3.18 folds higher as compared with that obtained by injection of MB (P < 0.05). As expected, there were no obvious contrast enhancement of the skeletal muscles with both MB(RGD) and MB. There was a high expression of αvß3-integrin in tumor neovascular endothelium, however, no apparent expression of αvß3-integrin was observed in the skeletal muscle vascular endothelium. CONCLUSION: CEU with MB(RGD) can be used to effectively evaluate the angiogenesis of tumors, and it may greatly contribute to the early judgement of the nature of tumor.

[Molecular imaging of thrombus with microbubbles targeted to alphavbeta3-integrin using an agarose flow chamber model].

OBJECTIVE: To assess the binding ability of microbubbles targeted to alphavbeta3-integrin (MBp) for thrombus-targeted contrast-enhanced ultrasound. METHODS: Targeted microbubbles were prepared by conjugating the monoclonal antibody against alphavbeta3-integrin to lipid shell of the microbubble via the avidin-biotin bridges. Equivalent isotype control microbubbles (MB) or targeted ultrasound microbubbles (MBp) were randomly added into the flow chamber. After a 30-min incubation with the thrombus fixed in an agarose flow chamber model, the thrombus was washed with a continuous flow of PBS solution (15 cm/s) for 2, 4, 6, 8 and 10 min, followed by thrombus imaging using contrast-enhanced ultrasound and measurement of the video intensity (VI) values of the images. RESULTS: The VI of the thrombus in MBp group was reduced by 28%-66%, while that in control MB group was decreased by 87%-94%, and the VI values of the thrombus group were significantly greater in former group at each of the time points (P<0.05). CONCLUSION: MBP has good targeting ability to the thrombus with resistance to the shear stress after adhesion to the thrombus. In vitro evaluation of the thrombus-binding capability of the targeted microbubble (MBp) by simulating the shear stress in vivo can be helpful for predicting the in vivo effects of ultrasonic molecular imaging using MBp.

[Evaluation of myocardial ischemia-reperfusion injury in mouse by molecular imaging of P-selectin with targeted contrast echocardiography].

OBJECTIVE: To assess the feasibility of evaluating myocardial ischemia-reperfusion injury in mouse with targeted myocardial contrast echocardiography (MCE). METHODS: Phospholipid microbubbles targeted to P-selectin (MBp) and control microbubbles (MBc) were created by conjugating monoclonal antibody against murine P-selectin or isotype control antibody with the lipid shell via "avidin-biotin" bridging. Ten mice with myocardial ischemia-reperfusion were injected intravenously of MBp and MBc in a random order with a 30 min interval. After 5 min of intravenous injection of microbubble, targeted MCE imaging was performed in all mice. And then the video intensity (VI) was determined. RESULTS: A significant ultrasonic enhancement was observed in ischemic region of MBp-group. Increment in VI value of ischemic region in MBp-group was great and it amounted to (26.0 +/- 6.2) U. However, increment in VI value of ischemic region in MBc-group was minor and it was merely (9.1 +/- 0.9) U. Difference was evident in ischemic region between of two groups (P < 0.05). In both MBp-group and MBc-group, the VI value of ischemic region was significantly greater than that of non-ischemic region (6.5 +/- 1.0) U vs (6.4 +/- 0.8) U (P < 0.05). There was no obvious difference in the VI of non-ischemic region between two groups. CONCLUSION: Molecular imaging of P-selectin with targeted contrast echocardiography can effectively evaluate myocardial ischemia-reperfusion injury.