E3 Ubiquitin Ligase ASB14 Inhibits Cardiomyocyte Proliferation by Regulating MAPRE2 Ubiquitination.

The ubiquitin proteasome system is a highly specific and selective protein regulatory system that plays an essential role in the regulation of the cell cycle. Despite its significance, the role of ubiquitination in cardiomyocyte proliferation remains largely unclear. This study aimed to investigate the potential impact of E3 ubiquitin ligase ASB14 (Ankyrin Repeat And SOCS Box Containing 14) on cardiac regeneration. We conducted a microarray analysis of apical resection ventricle tissues, and our findings revealed that ASB14 was down-regulated during the cardiac regenerative response. Subsequently, we examined the effect of ASB14 silencing on cardiomyocyte nuclear proliferation both in vitro and in vivo. Our results indicated that ASB14 silencing promoted cardiomyocyte nuclear proliferation, suggesting that ASB14 may play a role in regulating cardiac regeneration. To further investigate the potential therapeutic implications of ASB14 deficiency, we examined the cardiac function of mice with ASB14 deficiency in response to ischemic injury. Our findings showed that mice with ASB14 deficiency exhibited preserved cardiac function and a therapeutic effect in response to ischemic injury, which was attributed to the enhancement of cardiomyocyte nuclear proliferation. To elucidate the underlying mechanisms, we investigated the effect of ASB14 on microtubule-associated protein RP/EB family member 2 (MAPRE2) protein degradation. Our results indicated that the loss of ASB14 decreased the degradation of MAPRE2 protein, subsequently promoting cardiomyocyte nuclear proliferation and enhancing cardiac repair after myocardial infarction (MI). In conclusion, our study provides evidence that inhibition of ASB14-mediated MAPRE2 ubiquitination promotes cardiomyocyte nuclear proliferation, which may serve as a potential target for treating heart failure induced by MI injury.

Outcome of multimodal MRI-guided intravenous thrombolysis in patients with stroke with unknown time of onset.

OBJECTIVE: Intravenous tissue plasminogen activator (tPA) is the standard therapy for patients with acute ischaemic stroke (AIS) within 4.5 hours of onset. Recent trials have expanded the endovascular treatment window to 24 hours. We investigated the efficacy and safety of using multimodal MRI to guide intravenous tPA treatment for patients with AIS of unknown time of onset (UTO). METHODS: Data on patients with AIS with UTO and within 4.5 hours of onset were reviewed. Data elements collected and analysed included: demographics, National Institutes of Health Stroke Scale (NIHSS) score at baseline and 2 hours, 24 hours, 7 days after thrombolysis and before discharge, the modified Rankin Scale (mRS) score at 3 months after discharge, imaging findings and any adverse event. RESULTS: Forty-two patients with UTO and 62 in control group treated within 4.5 hours of onset were treated with intravenous tPA. The NIHSS scores after thrombolysis and/or before discharge in UTO group were significantly improved compared with the baseline (p<0.05). Between the two groups, no significant differences in NIHSS score were observed (p>0.05). Utilising the non-inferiority test, to compare mRS scores (0-2) at 3 months between the two groups, the difference was 5.2% (92% CI, OR 0.196). Patients in the UTO group had mRS scores of 0-2, which were non-inferior to the control group. Their incidence of adverse events was similar. CONCLUSIONS: Utilising multimodal MRI to guide intravenous only thrombolysis for patients with AIS with UTO was safe and effective. In those patients with AIS between 6 and 24 hours of time of onset but without large arterial occlusion, intravenous thrombolysis could be considered an option.

Administration of tissue plasminogen activator without coagulation results in a Chinese population.

Routine coagulation test before intravenous tissue plasminogen activator (tPA) use increases the door to needle time (DNT). We sought to evaluate the safety of tPA use without coagulation results and its impact on prognosis. In our stroke registry, tPA was delivered with coagulation results from December 2015 to April 2016 and without coagulation results from May 2016 to December 2016. Differences of demographics, clinical characteristic, and prognosis between these two groups were analyzed. In addition, logistic regression analysis was conducted to identify predictors for DNT of over 60 min. A total of 201 stroke patients were included in the final analysis. Of these, 81 patients received tPA with coagulation results and 120 patients without coagulation results. Only one (0.8%) patient with abnormal coagulation results met the exclusion criteria of tPA use in patients without coagulation results. The difference of DNT between groups with (mean, 61.7 min) and without (mean, 41.9 min) coagulation results was significant (P = 0.00). The group without coagulation results had a higher rate of favorable 90-day outcome (74.2 vs 70.4%) and lower rates of symptomatic intracranial hemorrhage/nonintracranial hemorrhage (4.9 and 22.2% vs 1.7 and 19.2%) than the group with coagulation results did; these differences were not statistically significant. In multivariate analysis, only tPA use with coagulation results was the predictor for DNT of over 60 min (P = 0.0030, OR = 2.44, 95% CI 1.28-4.65). The present study suggests that tPA could be delivered safely without coagulation results in patients without suspected coagulopathy, and avoiding coagulation tests reduces significantly the DNT interval.

Validation of simplified FABS scale to predict stroke mimics in a Chinese population undergoing intravenous thrombolysis.

OBJECTIVES: A large number of suspected stroke patients undergoing intravenous thrombolysis are stroke mimics (SMs). In this study, we sought to revise the FABS scale for screening and stratifying SMs from acute ischemic stroke (AIS) in a Chinese stroke population receiving fibrinolytic therapy. PATIENTS AND METHODS: The simplified FABS (sFABS) scale includes 4 items with 1 point for each item present: absence of facial droop, negative history of atrial fibrillation, age <50years, systolic blood pressure <150mm Hg at presentation. We evaluated consecutive suspected stroke patients undergoing intravenous thrombolysis in our stroke center for validation of sFABS scale. Diagnosis of SMs was based on absence of acute ischemic lesions on first and second diffusion weight imaging sequence in addition to an alternate diagnosis at discharge. RESULTS: A total of 190 AIS patients and 28 SMs were included in this study from December 2015 to February 2017. The sFABS scale showed excellent discrimination (C statistic: 0.928, 95% CI: 0.887-0.969, P<0.001). The Hosmer and Lemeshow goodness of fit test showed that the sFABS scale also had a good calibration (Cox and Snell R2=0.294, Nagelkerke R2=0.549). The plot of observed versus predicted risk of SMs showed high correlation (Pearson correlation coefficient: 0.983) between observed and predicted risk in our registered stroke population. CONCLUSION: The sFABS scale had excellent discrimination and good calibration abilities to predict SMs among a Chinese stroke population receiving tPA therapy. Further imaging evaluation may be necessary before the use of tPA if the sFABS score is higher.

Minor Nonintracranial Hemorrhage and Poor Prognosis among Stroke Patients Undergoing Intravenous Thrombolysis.

BACKGROUND: Whether nonintracranial hemorrhage (NICH) associated with intravenous thrombolysis (IVT) is a predictor of intracranial hemorrhage (ICH) and poor prognosis is ambiguous. We sought to analyze the rate of NICH and the relationship between NICH and poor outcome in the ischemic stroke population undergoing IVT. METHODS: This is a single-center, hospital-based prospective study. All ischemic stroke patients undergoing IVT between December 2015 and November 2016 were included. NICH was defined according to the criteria of the Bleeding Academic Research Consortium (BARC). ICH associated with IVT was defined based on the European Cooperative Acute Stroke Study II definition. On the basis of the modified Rankin Scale (mRS), 90-day outcome was divided into favorable outcome (mRS score 0-1) versus unfavorable outcome (mRS score 2-6) and independency (mRS score 0-2) versus dependency and death (mRS score 3-6). RESULTS: A total of 212 patients undergoing IVT were included in the analysis. Forty-five NICH events were reported in 42 patients (19.8%). Older age was independently associated with NICH (P = .049, odds ratio [OR] = .97, 95% confidence interval [CI] .94-1.0). Neither NICH with BARC class 1 or higher (P = .56, OR = .61, 95% CI .11-3.24) nor NICH with BARC class 2 or higher (P = .87, OR = 1.19, 95% CI .14-10.23) was associated with ICH. NICH with BARC class 1 or higher was not associated with unfavorable outcome (P = .67, OR = 1.17, 95% CI .56-2.45) and dependence and death (P = .47, OR = .72, 95% CI .30-1.75), neither was NICH with BARC class 2 or higher (P = .97, OR = 1.02, 95% CI .46-2.27 and P = .30, OR = .59, 95% CI .22-1.62). CONCLUSIONS: NICH was common among ischemic stroke populations receiving IVT. NICH with BARC class 2 or lower was not associated with ICH and poor outcome.