Nicorandil-Pretreated Mesenchymal Stem Cell-Derived Exosomes Facilitate Cardiac Repair After Myocardial Infarction via Promoting Macrophage M2 Polarization by Targeting miR-125a-5p/TRAF6/IRF5 Signaling Pathway

Background

Exosomes derived from bone marrow mesenchymal stem cells (MSC-exo) have been considered as a promising cell-free therapeutic strategy for ischemic heart disease. Cardioprotective drug pretreatment could be an effective approach to improve the efficacy of MSC-exo. Nicorandil has long been used in clinical practice for cardioprotection. This study aimed to investigate whether the effects of exosomes derived from nicorandil pretreated MSC (MSCNIC-exo) could be enhanced in facilitating cardiac repair after acute myocardial infarction (AMI).

Methods

MSCNIC-exo and MSC-exo were collected and injected into the border zone of infarcted hearts 30 minutes after coronary ligation in rats. Macrophage polarization was detected 3 days post-infarction, cardiac function as well as histological pathology were measured on the 28th day after AMI. Macrophages were separated from the bone marrow of rats for in vitro model. Exosomal miRNA sequencing was conducted to identify differentially expressed miRNAs between MSCNIC-exo and MSC-exo. MiRNA mimics and inhibitors were transfected to MSCs or macrophages to explore the specific mechanism.

Results

Compared to MSC-exo, MSCNIC-exo showed superior therapeutic effects on cardiac functional and structural recovery after AMI and markedly elevated the ratio of CD68+ CD206+/ CD68+cells in infarcted hearts 3 days post-infarction. The notable ability of MSCNIC-exo to promote macrophage M2 polarization was also confirmed in vitro. Exosomal miRNA sequencing and both in vivo and in vitro experiments identified and verified that miR-125a-5p was an effector of the roles of MSCNIC-exo in vivo and in vitro. Furthermore, we found miR-125a-5p promoted macrophage M2 polarization by inhibiting TRAF6/IRF5 signaling pathway.

Conclusion

This study suggested that MSCNIC-exo could markedly facilitate cardiac repair post-infarction by promoting macrophage M2 polarization by upregulating miR-125a-5p targeting TRAF6/IRF5 signaling pathway, which has great potential for clinical translation.

Association Between Systemic Immune Inflammation Level and Poor Prognosis Across Different Glucose Metabolism Status in Coronary Artery Disease Patients

Background

Blood glucose levels significantly affect the clinical prognosis of patients with coronary artery disease (CAD), and systemic immune inflammation is a common risk factor for both CAD and diabetes. However, the relationship between immune inflammation levels and poor prognosis in patients with CAD with different glucose metabolic statuses remains unclear.

Methods

Between January 2007 and December 2020, we recruited 84,645 patients with CAD. The systemic immune inflammation index (SII) was used to comprehensively reflect the immune and inflammatory levels of patients and was calculated using the following formula: neutrophils × platelets/lymphocytes. The patients were classified into nine groups according to their glucose metabolism status (diabetes mellitus [DM], pre-diabetes mellitus [pre-DM], and normal glucose regulation [NGR]). Cox regression models and competing risk Fine and Gray models were used to investigate the association between SII and clinical outcomes.

Results

During the follow-up period, 12,578 patients died, including 5857 cardiovascular-related and 1251 cancer-related deaths. The risk of all-cause and cause-specific mortality increased with increasing SII tertiles in CAD patients with NGR, pre-DM, and DM. When considering glucose metabolism status, the multivariate cox regression revealed that CAD patients with DM and SII-H levels had the highest risk of all-cause mortality (1.69 [1.56-1.83]), cardiovascular mortality (2.29 [2.02-2.59]), and cancer mortality (1.29 [1.01-1.66]). Moreover, incorporating the SII into traditional risk factor models significantly improved the C-index for predicting all-cause and cardiovascular mortality.

Conclusion

Systemic immune inflammation levels on admission were correlated with a higher risk of all-cause and cause-specific mortality in patients with CAD, particularly in those with DM.

Elevation of Preprocedural Systemic Immune Inflammation Level Increases the Risk of Contrast-Associated Acute Kidney Injury Following Coronary Angiography: A Multicenter Cohort Study

Background

Inflammation and immune responses play an important role in the pathophysiology of contrast-associated acute kidney injury (CA-AKI), and systemic immune inflammation index (SII) has recently emerged as a new parameter for immune and inflammatory response evaluation. However, limited research has been undertaken to explore the relationship between SII and CA-AKI following coronary angiography (CAG).

Patients and Methods

From January 2007 to December 2020, 46,333 patients undergoing CAG were included from 5 Chinese tertiary hospitals. SII was calculated as total peripheral platelets count × neutrophil-to-lymphocyte ratio. Patients were categorized by preprocedural SII quartiles: Q1 ≤404.5, Q2 >404.5 and ≤631.7, Q3 >631.7 and ≤1082.8, Q4 >1082.8. Univariable and multivariable logistic regression were used to reveal the link between preprocedural SII and CA-AKI.

Results

A total of the 46,333 patients (62.9 ± 11.5 years, female 28.1%) were included in the study. The incidence of CA-AKI was 8.4% in Q1 group, 8.7% in Q2 group, 9.4% in Q3 group, 15.1% in Q4 group. In the multivariable model, comparing the highest (Q4 group) to lowest (Q1 group) SII level categories, preprocedural SII was related to a higher risk of CA-AKI after fully adjusting for well-known confounders, and there was no statistically difference in the other two SII level categories (Q2 and Q3 groups) compared with Q1 group (adjusted model 3: Q2 group: OR: 0.98, 95% CI: 0.87–1.11, P = 0.771; Q3 group: OR: 1.04, 95% CI: 0.92–1.18, P = 0.553; Q4: OR: 1.65, 95% CI: 1.45–1.88, p < 0.001; P for trend < 0.001). Similar results were found for all the subgroups analysis except for patients undergoing PCI, and the interaction analyses for age, PCI and AMI were significant. In addition, Kaplan–Meier curves demonstrated that the lowest quartile group showed the worst all-cause mortality in a significant SII level-dependent manner among the four groups (Log rank test; p < 0.0001).

Conclusion

Elevated preprocedural SII level was a significant and independent risk factor for CA-AKI following CAG. Higher-quality prospective studies are needed to validate the predictive value of SII for CA-AKI.