HIV-1 Vpr Triggers Mitochondrial Destruction by Impairing Mfn2-Mediated ER-Mitochondria Interaction

Human immunodeficiency virus 1 (HIV-1) viral protein R (Vpr) has been shown to induce host cell death by increasing the permeability of mitochondrial outer membrane (MOM). The mechanism underlying the damage to the mitochondria by Vpr, however, is not clearly illustrated. In this study, Vpr that is introduced, via transient transfection or lentivirus infection, into the human embryonic kidney cell line HEK293, human CD4+ T lymphoblast cell line SupT1, or human primary CD4+ T cells serves as the model system to study the molecular mechanism of Vpr-mediated HIV-1 pathogenesis. The results show that Vpr injures MOM and causes a loss in membrane potential (MMP) by posttranscriptionally reducing the expression of mitofusin 2 (Mfn2) via VprBP-DDB1-CUL4A ubiquitin ligase complex, gradually weakening MOM, and increasing mitochondrial deformation. Vpr also markedly decreases cytoplasmic levels of dynamin-related protein 1 (DRP1) and increases bulging in mitochondria-associated membranes (MAM), the specific regions of endoplasmic reticulum (ER) which form physical contacts with the mitochondria. Overexpression of Mfn2 and DRP1 significantly decreased the loss of MMP and apoptotic cell death caused by Vpr. Furthermore, by employing time-lapse confocal fluorescence microscopy, we identify the transport of Vpr protein from the ER, via MAM to the mitochondria. Taken together, our results suggest that Vpr-mediated cellular damage may occur on an alternative protein transport pathway from the ER, via MAM to the mitochondria, which are modulated by Mfn2 and DRP1

Exclusive enteral nutrition with concomitant early thiopurine use was effective in maintaining steroid-free remission in a Southeast Asian cohort of children with Crohn’s disease

Abstract Background Exclusive enteral nutrition (EEN) is as effective as corticosteroids in inducing remission in children with Crohn’s disease (CD). However, over 50% of these children relapse by 12 months of diagnosis. Thiopurines are commonly prescribed as maintenance therapy for CD, but evidence for its efficacy is controversial. Data on the effectiveness of EEN in Southeast Asian (SEA) children with CD is scarce. This study aims to evaluate the efficacy of EEN induction therapy in a cohort of SEA children with newly diagnosed CD. The secondary aim was to evaluate concomitant early azathioprine (EAZ) use in determining remission rate at 6 and 12 months. Methods Case records of all children with newly diagnosed CD from 2011 to 2014 were reviewed and relevant demographic as well as clinical data were extracted. The primary outcome measure was the number of patients who completed EEN induction therapy and achieved remission (Paediatric Crohn’s Disease Activity Index; PCDAI≤10). Factors influencing duration of remission were evaluated in particular early azathioprine (EAZ) defined as starting azathioprine within one month of diagnosis versus late azathioprine (LAZ) use. Results Forty children with newly diagnosed CD were identified. Thirty-three children: 67% boys, median age 13y (range 3–17) completed 8 weeks of EEN induction therapy and 91% achieved remission. Significant improvements were seen in PCDAI scores (32.7 ± 9.2 to 4.2 ± 5.1; p < 0.001), mean BMI z-score (− 1.38 ± 1.57 to − 0.82 ± 1.27; p = 0.004) and baseline inflammatory markers: Erythrocyte Sedimentation Rate (51.6 ± 30.1 mm/h to 13.3 ± 7.1 mm/h; p < 0.0001) C-Reactive Protein (44.6 ± 51.0 mg/L to 5.2 ± 7.6 mg/L; p = 0.001), Albumin (30.7 ± 7.5 g/L to 38.7 ± 3.9 g/L; p < 0.0001), Platelets (464 ± 161 × 109 to 370 ± 111 × 109; p < 0.0001),. Early azathioprine initiation was associated with a remission rate of 80 and 73% at 6 and 12 months respectively. Remission was also maintained for longer duration in EAZ vs LAZ groups (p = 0.048). Conclusion EEN effectively induces remission in this cohort of SEA children with newly diagnosed CD. Early initiation of thiopurine with EEN induction therapy is effective in maintaining steroid-free remission for at least one year

Clinical Manifestations of Nontyphoid Salmonellosis in Children Younger than 2 Years Old—Experiences of a Tertiary Hospital in Southern Taiwan

Few published studies have explored the clinical manifestations of nontyphoid salmonellosis in children <2 years of age. The aim of this study was to investigate the clinical manifestations, microbiological features, complications, fecal excretion time, and responses to treatment in children <2 years of age with nontyphoid salmonellosis. Methods: Between January 2005 and December 2009, pediatric patients who were admitted to Kaohsiung Veterans General Hospital with positive cultures for nontyphoid Salmonella were enrolled. The following data were recorded: demographic, clinical, and microbiological features, underlying diseases, treatment regimen, complications, responses to treatment, and fecal excretion time. The clinical manifestations were compared between patients 2 years of age. Results: Of a total 279 enrolled patients, 179 were >2 years of age. Compared with the patients who were ≥2 years of age, patients <2 years of age demonstrated a significantly higher incidence of bloody stool, mixed infection, extraintestinal infection, longer course of antibiotics, longer course of diarrhea after admission, and more days spent in the hospital. The rates of insusceptibility of nontyphoid Salmonella to ampicillin, chloramphenicol, trimethoprim/sulfamethoxazole, ceftriaxone, and ciprofloxacin in patients <2 years of age were 37.87%, 29.09%, 23.73%, 3.26%, and 2.25%, respectively. Younger patients were generally more susceptible to antibiotics than patients ≥2 years of age, although this result was not statistically significant. Conclusion: The clinical manifestations of nontyphoid salmonellosis are more severe in younger children <2 years of age than older children. Local susceptibility patterns could serve as a guide for the prescription of antibiotics by clinicians

Overexpression of optic atrophy 1 protein increases cisplatin resistance via inactivation of caspase-dependent apoptosis in lung adenocarcinoma cells

Optic atrophy 1 protein, a 112-kd guanosine triphosphatase, is involved in the mitochondrial inner membrane fusion and anticancer drug-mediated cytotoxicity, which implicate an association with disease progression of the cancer. In this study, we investigated the prognostic value of optic atrophy 1 expression in patients with lung adenocarcinoma. Using immunohistochemical staining, expression of optic atrophy 1 was determined in 286 lung adenocarcinoma patients. Expression of optic atrophy 1 was confirmed by immunoblotting. The relationship between optic atrophy 1 expression and clinicopathological parameters was analyzed statistically by comparing survival between different groups using the log-rank test. The results showed that optic atrophy 1 overexpression was detected in 219 (76.6%) of lung adenocarcinoma patients. A significant difference was found in cumulative survival between patients with high optic atrophy 1 levels and those with low optic atrophy 1 levels (P = .0016). In the in vitro experiments with cell lines, silencing of optic atrophy 1 expression reduced cisplatin resistance, which was further shown via increased release of cytochrome c and activation of caspase-dependent apoptotic pathway. In conclusion, optic atrophy 1 is highly expressed in lung adenocarcinoma and indicates poor prognosis. (C) 2012 Elsevier Inc. All rights reserved

Protein supplementation versus standard feeds in underweight critically ill children : A pilot dual-centre randomised controlled trial protocol

Introduction Protein-energy malnutrition, increased catabolism and inadequate nutritional support leads to loss of lean body mass with muscle wasting and delayed recovery in critical illness. However, there remains clinical equipoise regarding the risks and benefits of protein supplementation. This pilot trial will determine the feasibility of performing a larger multicentre trial to determine if a strategy of protein supplementation in critically ill children with body mass index (BMI) z-score ≤-2 is superior to standard enteral nutrition in reducing the length of stay in the paediatric intensive care unit (PICU). Methods and analysis This is a randomised controlled trial of 70 children in two PICUs in Singapore. Children with BMI z-score ≤-2 on PICU admission, who are expected to require invasive mechanical ventilation for more than 48 hours, will be randomised (1:1 allocation) to protein supplementation of ≥1.5 g/kg/day in addition to standard nutrition, or standard nutrition alone for 7 days after enrolment or until PICU discharge, whichever is earlier. Feasibility outcomes for the trial include effective screening, satisfactory enrolment rate, timely protocol implementation (within first 72 hours) and protocol adherence. Secondary outcomes include mortality, PICU length of stay, muscle mass, anthropometric measurements and functional outcomes. Ethics and dissemination The trial protocol was approved by the institutional review board of both participating centres (Singhealth Centralised Institutional Review Board and National Healthcare Group Domain Specific Review Board) under the reference number 2020/2742. Findings of the trial will be disseminated through peer-reviewed journals and scientific conferences. Trial registration number NCT04565613.publishedVersionPeer reviewe