Critical role of miR-21/exosomal miR-21 in autophagy pathway

Activation of autophagy, a process of cellular stress response, leads to the breakdown of proteins, organelles, and other parts of the cell in lysosomes, and can be linked to several ailments, such as cancer, neurological diseases, and rare hereditary syndromes. Thus, its regulation is very carefully monitored. Transcriptional and post-translational mechanisms domestically or in whole organisms utilized to control the autophagic activity, have been heavily researched. In modern times, microRNAs (miRNAs) are being considered to have a part in post-translational orchestration of the autophagic activity, with miR-21 as one of the best studied miRNAs, it is often more than expressed in cancer cells. This regulatory RNA is thought to play a major role in a plethora of processes and illnesses including growth, cancer, cardiovascular disease, and inflammation. Different studies have suggested that a few autophagy-oriented genes, such as PTEN, Rab11a, Atg12, SIPA1L2, and ATG5, are all targeted by miR-21, indicating its essential role in the regulation.

Clinical implication of ticagrelor monotherapy in patients with small vessel coronary artery disease: results from the TICO randomized trial

Background

The aim of this study was to evaluate the efficacy and safety of ticagrelor monotherapy in patients with small vessel disease compared with ticagrelor-based DAPT within the Ticagrelor Monotherapy after 3 Months in the Patients Treated with New Generation Sirolimus Eluting Stent for Acute Coronary Syndrome (TICO) trial population.

Methods

Reference vessel diameter ≤2.5 mm was considered as small vessel disease. We conducted a comparison of the incidence of target lesion failure (TLF) and Bleeding Academic Research Consortium (BARC) type 3 or 5 bleeding. TLF was defined as a composite of cardiac death, target lesion myocardial infarction, stent thrombosis, and target lesion revascularization.

Results

652 patients among 3,056 TICO population (21.3%) had small vessel disease. Patients with small vessel disease showed a higher rate of TLF compared to those without small vessel disease (2.9% vs. 1.0%, log-rank p < 0.001). The presence of small vessel disease emerged as an independent predictor for 1-year TLF (HR 2.84, 95% CI 1.54-5.25), while it did not show a significant association with bleeding complications. The 12-month TLF rate was 1.6% for ticagrelor monotherapy after 3-month DAPT, and 4.2% for ticagrelor-based 12-month DAPT (p = 0.059) in patients with small vessel disease (HR 0.38, 95% CI 0.14-1.04, p for interaction = 0.261). The incidence of BARC type 3 or 5 bleeding rate 2.5% for ticagrelor monotherapy after 3-month DAPT, and 5.6% for ticagrelor-based 12-month DAPT (p = 0.052) in patients with small vessel disease (HR 0.44, 95% CI 0.19-1.01, p for interaction = 0.322). In the 3-month landmark analysis, ticagrelor monotherapy significantly reduced BARC type 3 or 5 bleeding in patients with small vessel disease (HR 0.09, 95% CI 0.01-0.69, log-rank p = 0.005) while demonstrating a similar incidence of TLF compared to ticagrelor based 12-month DAPT during the 3-12 months period.

Conclusions

There are no significant interactions between the antiplatelet strategy regarding the 12-month incidence of ischemic and bleeding complications. Ticagrelor monotherapy demonstrated a reduction in bleeding complications after a 3-month period of DAPT without increasing the rate of TLF, when compared to ticagrelor-based 12-month DAPT, specifically in patients with small vessel disease. Clinical Trial Registration: www.ClinicalTrials.gov, identifier, NCT02494895.

Long-term safety and efficacy of the Resolute stent: 5-year results from the RESOLUTE China Registry: RESOLUTE China Registry 5-year outcomes

AIMS

Long-term clinical outcome data for second-generation drug-eluting stents (DES) are critical for the assessment of safety and efficacy. Five-year results from the RESOLUTE China Registry are presented in this report.

METHODS AND RESULTS

The RESOLUTE China Registry is a prospective, multicentre, observational study for all-comers requiring coronary stent implantation. The primary endpoint was target lesion failure (TLF) at one year, and the main secondary endpoint was definite or probable stent thrombosis at one year. Additional secondary endpoints assessed up to 5 years include rates of all deaths, target vessel myocardial infarction (TVMI) and target lesion revascularisation (TLR). A total of 1,800 patients were enrolled from December 2010 to March 2012 at 30 sites in China and implanted with Resolute DES. At 5 years, TLF was 9.8%, TVMI 3.2%, TLR 4.6% and very late stent thrombosis 0.5%. Results of pre-specified subgroup analyses show 5-year TLF rates of 14.3% for diabetics and 13.4% for patients with chronic total occlusions.

CONCLUSIONS

The RESOLUTE China Registry is the largest study of Asian patients treated with second-generation Resolute DES. Clinical outcomes illustrate a robust safety and efficacy profile of Resolute DES in a real-word Asian population, including favourable performance in complex patient subsets.

1-Year Outcomes with COMBO Stents in Small-Vessel Coronary Disease: Subgroup Analysis From the COMBO Collaboration

BACKGROUND

Small vessel diameter is associated with higher risk of target lesion revascularization (TLR) after percutaneous coronary intervention (PCI). The COMBO sirolimus-eluting biodegradable-polymer stent has a proprietary anti-CD34 antibody layer to enhance homogeneous endothelialization, which may be advantageous in treating small vessels.

OBJECTIVE

We examined for differences in 1-year clinical outcomes after PCI by maximum implanted stent diameter from the COMBO collaboration.

METHODS

The COMBO collaboration (n = 3614) is a patient-level pooled dataset of patients undergoing PCI with COMBO stents in the MASCOT and REMEDEE multicenter registries. Stent diameter was available in 3590 (99.3%) patients. We compared patients receiving COMBO stents <3 mm versus ≥3 mm. The primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, target vessel-myocardial infarction (TV-MI) or clinically driven TLR. Secondary outcomes included stent thrombosis (ST). Adjusted outcomes were assessed using Cox regression methods.

RESULTS

The study included 792 (22%) patients with small stents <3 mm and 2798 (78%) patients with large stents ≥3 mm. Small stent patients included more women with lower body mass index and higher prevalence of diabetes but similar prevalence of acute coronary syndrome. Risk of 1-year TLF was similar in small and large stent groups (4.4% vs. 3.8%, HR 1.12, 95% CI 0.74-1.72, p = 0.58). There were no differences in the rates of cardiac death (1.7% vs. 1.5%, p = 0.74), TV-MI (1.4% vs. 1.2%, p = 0.58) or TLR (2.7% vs. 2.1%, p = 0.31). Definite or probable ST occurred in 1.3% of the small stent and 0.7% of the large stent PCI patients, p = 0.14, HR 2.13, 95% CI 0.93-5.00, p = 0.07.

CONCLUSIONS

One-year ischemic outcomes after COMBO PCI were similar irrespective of stent diameter in this all-comers international cohort.

Erythropoietin helix B surface peptide modulates miR-21/Atg12 axis to alleviates cardiomyocyte hypoxia-reoxygenation injury

BACKGROUND

The erythropoietin helix B surface peptide (HBSP) has been shown to have neuroprotective and repair-damaging myocardium effects similar to erythropoietin (EPO). However, the protective mechanism of HBSP on cardiomyocyte hypoxia-reoxygenation (H/R) injury is not clear.

METHODS

H9C2 cells were pretreated with HBSP and subjected to hypoxia/reoxygenation (H/R), changes in cell function, autophagy and apoptosis were assessed, respectively. Cells were transfected with miR-21 mimic and miR-NC, and the relative expression of miR-21 and Atg12 were detected by qRT-PCR. The target role of miR-21 and Atg12 was evaluated by dual-luciferase reporter. After transfected with si-Atg12 and si-NC, western blot was used to assess autophagy and apoptosis proteins, flow cytometry assay was used to detect apoptosis rate.

RESULTS

We found the expression of miR-21 was significantly down-regulated, accompanied by remarkably activated of autophagy and apoptosis in H9C2 cells during H/R injury. Pleasantly, HBSP pretreatment has a similar effect as transfection of miR-21 mimic, which is to evidently inhibit autophagy and apoptosis by up-regulating miR-21 expression. Moreover, Bioinformatics analysis and luciferase reporter assay revealed that Atg12 was directly bond to miR-21. To further understand whether Atg12 is involved in the process of miR-21 regulating autophagy, si-Atg12 and si-NC were transfected into H9C2 cell, the results showed that knockdown of Atg12 enhances the inhibition autophagy and apoptosis effect of HBSP.

CONCLUSION

These results demonstrate that HBSP inhibits myocardial H/R injury induced by autophagy over-activation and apoptosis via miR-21/Atg12 axis.