miR-181c Activates Mitochondrial Calcium Uptake by Regulating MICU1 in the Heart.

Background Translocation of miR-181c into cardiac mitochondria downregulates the mitochondrial gene, mt-COX1. miR-181c/d-/- hearts experience less oxidative stress during ischemia/reperfusion (I/R) and are protected against I/R injury. Additionally, miR-181c overexpression can increase mitochondrial matrix Ca2+ ([Ca2+]m), but the mechanism by which miR-181c regulates [Ca2+]m is unknown. Methods and Results By RNA sequencing and analysis, here we show that hearts from miR-181c/d-/- mice overexpress nuclear-encoded Ca2+ regulatory and metabolic pathway genes, suggesting that alterations in miR-181c and mt-COX1 perturb mitochondria-to-nucleus retrograde signaling and [Ca2+]m regulation. Quantitative polymerase chain reaction validation of transcription factors that are known to initiate retrograde signaling revealed significantly higher Sp1 (specificity protein) expression in the miR-181c/d-/- hearts. Furthermore, an association of Sp1 with the promoter region of MICU1 was confirmed by chromatin immunoprecipitation-quantitative polymerase chain reaction and higher expression of MICU1 was found in the miR-181c/d-/- hearts. Conversely, downregulation of Sp1 by small interfering RNA decreased MICU1 expression in neonatal mouse ventricular myocytes. Changes in PDH activity provided evidence for a change in [Ca2+]m via the miR-181c/MICU1 axis. Moreover, this mechanism was implicated in the pathology of I/R injury. When MICU1 was knocked down in the miR-181c/d-/- heart by lentiviral expression of a short-hairpin RNA against MICU1, cardioprotective effects against I/R injury were abrogated. Furthermore, using an in vitro I/R model in miR-181c/d-/- neonatal mouse ventricular myocytes, we confirmed the contribution of both Sp1 and MICU1 in ischemic injury. Conclusions miR-181c regulates mt-COX1, which in turn regulates MICU1 expression through the Sp1-mediated mitochondria-to-nucleus retrograde pathway. Loss of miR-181c can protect the heart from I/R injury by modulating [Ca2+]m through the upregulation of MICU1.

Caplacizumab Treatment for Acquired Thrombotic Thrombocytopenic Purpura.

BACKGROUND: In acquired thrombotic thrombocytopenic purpura (TTP), an immune-mediated deficiency of the von Willebrand factor-cleaving protease ADAMTS13 allows unrestrained adhesion of von Willebrand factor multimers to platelets and microthrombosis, which result in thrombocytopenia, hemolytic anemia, and tissue ischemia. Caplacizumab, an anti-von Willebrand factor humanized, bivalent variable-domain-only immunoglobulin fragment, inhibits interaction between von Willebrand factor multimers and platelets. METHODS: In this double-blind, controlled trial, we randomly assigned 145 patients with TTP to receive caplacizumab (10-mg intravenous loading bolus, followed by 10 mg daily subcutaneously) or placebo during plasma exchange and for 30 days thereafter. The primary outcome was the time to normalization of the platelet count, with discontinuation of daily plasma exchange within 5 days thereafter. Key secondary outcomes included a composite of TTP-related death, recurrence of TTP, or a thromboembolic event during the trial treatment period; recurrence of TTP at any time during the trial; refractory TTP; and normalization of organ-damage markers. RESULTS: The median time to normalization of the platelet count was shorter with caplacizumab than with placebo (2.69 days [95% confidence interval {CI}, 1.89 to 2.83] vs. 2.88 days [95% CI, 2.68 to 3.56], P=0.01), and patients who received caplacizumab were 1.55 times as likely to have a normalization of the platelet count as those who received placebo. The percentage of patients with a composite outcome event was 74% lower with caplacizumab than with placebo (12% vs. 49%, P<0.001). The percentage of patients who had a recurrence of TTP at any time during the trial was 67% lower with caplacizumab than with placebo (12% vs. 38%, P<0.001). Refractory disease developed in no patients in the caplacizumab group and in three patients in the placebo group. Patients who received caplacizumab needed less plasma exchange and had a shorter hospitalization than those who received placebo. The most common adverse event was mucocutaneous bleeding, which was reported in 65% of the patients in the caplacizumab group and in 48% in the placebo group. During the trial treatment period, three patients in the placebo group died. One patient in the caplacizumab group died from cerebral ischemia after the end of the treatment period. CONCLUSIONS: Among patients with TTP, treatment with caplacizumab was associated with faster normalization of the platelet count; a lower incidence of a composite of TTP-related death, recurrence of TTP, or a thromboembolic event during the treatment period; and a lower rate of recurrence of TTP during the trial than placebo. (Funded by Ablynx; HERCULES ClinicalTrials.gov number, NCT02553317 .).

miR-181b regulates vascular stiffness age dependently in part by regulating TGF-ß signaling.

BACKGROUND: Endothelial dysfunction and arterial stiffening play major roles in cardiovascular diseases. The critical role for the miR-181 family in vascular inflammation has been documented. Here we tested whether the miR-181 family can influence the pathogenesis of hypertension and vascular stiffening. METHODS AND RESULTS: qPCR data showed a significant decrease in miR-181b expression in the aorta of the older mice. Eight miR-181a1/b1-/- mice and wild types (C57BL6J:WT) were followed weekly for pulse wave velocity (PWV) and blood pressure measurements. After 20 weeks, the mice were tested for endothelial function and aortic modulus. There was a progressive increase in PWV and higher systolic blood pressure in miR-181a1/b1-/- mice compared with WTs. At 21 weeks, aortic modulus was significantly greater in the miR-181a1/b1-/- group, and serum TGF-ß was found to be elevated at this time. A luciferase reporter assay confirmed miR-181b targets TGF-ßi (TGF-ß induced) in the aortic VSMCs. In contrast, wire myography revealed unaltered endothelial function along with higher nitric oxide production in the miR-181a1/b1-/- group. Cultured VECs and VSMCs from the mouse aorta showed more secreted TGF-ß in VSMCs of the miR-181a1/b1-/- group; whereas, no change was observed from VECs. Circulating levels of angiotensin II were similar in both groups. Treatment with losartan (0.6 g/L) prevented the increase in PWV, blood pressure, and vascular stiffness in miR-181a1/b1-/- mice. Immunohistochemistry and western blot for p-SMAD2/3 validated the inhibitory effect of losartan on TGF-ß signaling in miR-181a1/b1-/- mice. CONCLUSIONS: Decreased miR-181b with aging plays a critical role in ECM remodeling by removing the brake on the TGF-ß, pSMAD2/3 pathway.

A Bayesian approach for inference from a bridging study with binary outcomes.

To address concerns that ethnic differences in any clinical trial may affect the performance of a treatment, separate clinical trials may be required for different regions. If a drug is approved in one region based on a bigger clinical trial, a bridging study with smaller size may be conducted in a new region to evaluate the similarity of the earlier clinical data to the new population. This article applies a Bayesian strategy to combine a bridging study with reference studies to assess treatment effect similarity for binary endpoints. The methods have been illustrated with a numerical example using Markov-chain Monte Carlo (MCMC) techniques.

Randomized, investigator-blinded, multicenter, comparative study of gatifloxacin versus amoxicillin/clavulanate in recurrent otitis media and acute otitis media treatment failure in children.

BACKGROUND: Recurrent otitis media and acute otitis media treatment failure are commonly encountered in the pediatric population. OBJECTIVE: To compare the clinical efficacy of gatifloxacin with amoxicillin/clavulanate for the treatment of acute otitis media treatment failure and recurrent otitis media. METHODS: Three hundred fifty-four children 6 months-7 years with recurrent otitis media and/or acute otitis media failure were stratified according to age (younger than 2 years versus 2 years or older) and then randomly assigned to 10 days of treatment with gatifloxacin 10 mg/kg once daily or amoxicillin/clavulanate 90 mg/6.4 mg in 2 divided doses. Tympanocentesis was performed in 116 children with acute otitis media treatment failure and 52 with recurrent otitis media at study entry to validate the clinical diagnosis and provide microbiologic data. The primary outcome measure was clinical resolution of infection at the test-of-cure visit 3-10 days after completing treatment. RESULTS: Clinical resolution of acute otitis media was observed in 79.0% (49 of 62) of clinically evaluable children younger than 2 years and 90.3% (56 of 62) of those 2 years or older who were treated with gatifloxacin as compared with 77.6% (45 of 58) of children younger than 2 years and 79.7% (47 of 59) of children 2 years or older treated with amoxicillin/clavulanate. In patients with acute otitis media treatment failure, clinical response rates for children younger than 2 years and those 2 years or older were 87.5% (21 of 24) and 97.0% (32 of 33) with gatifloxacin versus 63.6% (14 of 22) and 83.9% (26 of 31) with amoxicillin/clavulanate. The corresponding clinical response rates in patients with recurrent otitis media were 79.2% (19 of 24) and 85.7% (18 of 21) with gatifloxacin and 90.5% (19 of 21) and 76.0% (19 of 25) with amoxicillin/clavulanate. Clinical success in those subjects having pretreatment middle ear fluid pathogens was similar for the 2 regimens [80.0% (24 of 30) gatifloxacin, 77.1% (27 of 35) amoxicillin/clavulanate]. Emergence of fluoroquinolone-resistant strains was not observed. Both drugs were generally well-tolerated. Diarrhea was the most common drug-related adverse event (10% gatifloxacin, 18% amoxicillin/clavulanate). No evidence of abnormal joint or gait findings was found during a 12-month follow-up. CONCLUSIONS: Gatifloxacin once daily is at least as effective and well-tolerated as amoxicillin/clavulanate twice daily in children with acute otitis media treatment failure or recurrent otitis media. There was no evidence of arthrotoxicity or emergence of fluoroquinolone-resistant bacteria in gatifloxacin-treated children.

Prostate specific antigen progression after radical prostatectomy in African-American men versus white men.

BACKGROUND: It is well established that African-American men (AAM) have a worse mortality from prostate carcinoma (PC) than White men (WM). Outcome data for men treated with radical prostatectomy for clinically localized PC demonstrate more advanced tumors and higher biochemical recurrence rates among AAM compared with WM. The objective of the current study was to characterize the pattern of prostate specific antigen (PSA) progression by race in patients experiencing disease recurrence after undergoing radical prostatectomy. Racial differences in the pattern of rising PSA would warrant different intervention strategies for reducing the disproportionality in survival outcomes between the two racial groups. METHODS: Between 1991-1996, 1080 consecutive men underwent radical prostatectomy for clinically localized PC at Wayne State University-affiliated Harper Hospital. Two hundred forty-one patients developed a biochemical recurrence on or before January, 1, 1999. The median follow-up was 39 months. Longitudinal PSA profiles of 77 men who met the study inclusion criteria were analyzed. Average relative velocities of PSA were compared between AAM and WM. Linear mixed effects regression was used to test the hypothesis that, after adjusting for age, preoperative PSA, stage and grade of disease, PSA levels increase at a faster rate in AAM compared with WM. RESULTS: The mean average relative velocity for AAM and WM experiencing a disease recurrence was 0.25 ng/mL and 0.11 ng/mL per month, respectively (P = 0.21). The relative rate of PSA increase in patients who developed a disease recurrence after radical prostatectomy was 18.9% per month for AAM and 16.3% per month for WM (P = 0.73). CONCLUSIONS: AAM and WM appear to have similar rates of PSA progression after undergoing radical prostatectomy.