Regulation of caveolin-1 membrane trafficking by the Na/K-ATPase

Here, we show that the Na/K-ATPase interacts with caveolin-1 (Cav1) and regulates Cav1 trafficking. Graded knockdown of Na/K-ATPase decreases the plasma membrane pool of Cav1, which results in a significant reduction in the number of caveolae on the cell surface. These effects are independent of the pumping function of Na/K-ATPase, and instead depend on interaction between Na/K-ATPase and Cav1 mediated by an N-terminal caveolin-binding motif within the ATPase α1 subunit. Moreover, knockdown of the Na/K-ATPase increases basal levels of active Src and stimulates endocytosis of Cav1 from the plasma membrane. Microtubule-dependent long-range directional trafficking in Na/K-ATPase–depleted cells results in perinuclear accumulation of Cav1-positive vesicles. Finally, Na/K-ATPase knockdown has no effect on processing or exit of Cav1 from the Golgi. Thus, the Na/K-ATPase regulates Cav1 endocytic trafficking and stabilizes the Cav1 plasma membrane pool

Identification and Characterization of AES-135, a Hydroxamic Acid-Based HDAC Inhibitor That Prolongs Survival in an Orthotopic Mouse Model of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive, incurable cancer with a 20% 1 year survival rate. While standard-of-care therapy can prolong life in a small fraction of cases, PDAC is inherently resistant to current treatments, and novel therapies are urgently required. Histone deacetylase (HDAC) inhibitors are effective in killing pancreatic cancer cells in in vitro PDAC studies, and although there are a few clinical studies investigating combination therapy including HDAC inhibitors, no HDAC drug or combination therapy with an HDAC drug has been approved for the treatment of PDAC. We developed an inhibitor of HDACs, AES-135, that exhibits nanomolar inhibitory activity against HDAC3, HDAC6, and HDAC11 in biochemical assays. In a three-dimensional coculture model, AES-135 kills low-passage patient-derived tumor spheroids selectively over surrounding cancer-associated fibroblasts and has excellent pharmacokinetic properties in vivo. In an orthotopic murine model of pancreatic cancer, AES-135 prolongs survival significantly, therefore representing a candidate for further preclinical testing

Structural basis for the role of Serine-Rich Repeat Proteins from Lactobacillus reuteri in gut microbe-host interactions

Lactobacillus reuteri, a Gram-positive bacterial species inhabiting the gastrointestinal tract of vertebrates displays remarkable host adaptation. Previous mutational analyses of rodent strain L. reuteri 100-23C identified a gene encoding a predicted surface-exposed serine-rich repeat protein (SRRP100-23) that was vital for L. reuteri biofilm formation in mice. SRRPs have emerged as an important group of surface proteins on many pathogens but no structural information is available in commensal bacteria. Here we report the 2.00 Å and 1.92 Å crystal structures of the binding regions (BRs) of SRRP100-23 and SRRP53608 from L. reuteri ATCC 53608, revealing a unique “β-solenoid” fold in this important adhesin family. BRSRRP53608 boundto host epithelial cells and DNA at neutral pH and recognised polygalacturonic acid (PGA), rhamnogalacturonan I or chondroitin sulfate A at acidic pH. Mutagenesis confirmed the role of the BR putative binding site in the interaction of BRSRRP53608 with PGA. Long molecular dynamics simulations showed that SRRP53608 undergoes a pH-dependent conformational change. Together, these findings shed new mechanistic insights into the role of SRRPs in host-microbe interactions and open new avenues of research into the use of biofilm-forming probiotics against clinically important pathogens

Patient outcomes after hospitalisation with COVID-19 and implications for follow-up:results from a prospective UK cohort

The longer-term consequences of SARS-CoV-2 infection are uncertain. Consecutive patients hospitalised with COVID-19 were prospectively recruited to this observational study (n=163). At 8–12 weeks postadmission, survivors were invited to a systematic clinical follow-up. Of 131 participants, 110 attended the follow-up clinic. Most (74%) had persistent symptoms (notably breathlessness and excessive fatigue) and limitations in reported physical ability. However, clinically significant abnormalities in chest radiograph, exercise tests, blood tests and spirometry were less frequent (35%), especially in patients not requiring supplementary oxygen during their acute infection (7%). Results suggest that a holistic approach focusing on rehabilitation and general well-being is paramount

Ethical issues relating to the banking of umbilical cord blood in Mexico

<p>Abstract</p> <p>Background</p> <p>Umbilical cord banks are a central component, as umbilical cord tissue providers, in both medical treatment and scientific research with stem cells. But, whereas the creation of umbilical cord banks is seen as successful practice, it is perceived as a risky style of play by others. This article examines and discusses the ethical, medical and legal considerations that arise from the operation of umbilical cord banks in Mexico.</p> <p>Discussion</p> <p>A number of experts have stated that the use of umbilical cord goes beyond the mere utilization of human tissues for the purpose of treatment. This tissue is also used in research studies: genetic studies, studies to evaluate the effectiveness of new antibiotics, studies to identify new proteins, etc. Meanwhile, others claim that the law and other norms for the functioning of cord banks are not consistent and are poorly defined. Some of these critics point out that the confidentiality of donor information is handled differently in different places. The fact that private cord banks offer their services as "biological insurance" in order to obtain informed consent by promising the parents that the tissue that will be stored insures the health of their child in the future raises the issue of whether the consent is freely given or given under coercion. Another consideration that must be made in relation to privately owned cord banks has to do with the ownership of the stored umbilical cord.</p> <p>Summary</p> <p>Conflicts between moral principles and economic interests (non-moral principles) cause dilemmas in the clinical practice of umbilical cord blood storage and use especially in privately owned banks. This article presents a reflection and some of the guidelines that must be followed by umbilical cord banks in order to deal with these conflicts. This reflection is based on the fundamental notions of ethics and public health and seeks to be a contribution towards the improvement of umbilical cord banks' performance.</p

Modifying effect of dual antiplatelet therapy on incidence of stent thrombosis according to implanted drug-eluting stent type

Aim To investigate the putative modifying effect of dual antiplatelet therapy (DAPT) use on the incidence of stent thrombosis at 3 years in patients randomized to Endeavor zotarolimus-eluting stent (E-ZES) or Cypher sirolimus-eluting stent (C-SES). Methods and results Of 8709 patients in PROTECT, 4357 were randomized to E-ZES and 4352 to C-SES. Aspirin was to be given indefinitely, and clopidogrel/ticlopidine for ≥3 months or up to 12 months after implantation. Main outcome measures were definite or probable stent thrombosis at 3 years. Multivariable Cox regression analysis was applied, with stent type, DAPT, and their interaction as the main outcome determinants. Dual antiplatelet therapy adherence remained the same in the E-ZES and C-SES groups (79.6% at 1 year, 32.8% at 2 years, and 21.6% at 3 years). We observed a statistically significant (P = 0.0052) heterogeneity in treatment effect of stent type in relation to DAPT. In the absence of DAPT, stent thrombosis was lower with E-ZES vs. C-SES (adjusted hazard ratio 0.38, 95% confidence interval 0.19, 0.75; P = 0.0056). In the presence of DAPT, no difference was found (1.18; 0.79, 1.77; P = 0.43). Conclusion A strong interaction was observed between drug-eluting stent type and DAPT use, most likely prompted by the vascular healing response induced by the implanted DES system. These results suggest that the incidence of stent thrombosis in DES trials should not be evaluated independently of DAPT use, and the optimal duration of DAPT will likely depend upon stent type (Clinicaltrials.gov number NCT00476957

Mutations in tropomyosin 4 underlie a rare form of human macrothrombocytopenia.

Platelets are anuclear cells that are essential for blood clotting. They are produced by large polyploid precursor cells called megakaryocytes. Previous genome-wide association studies in nearly 70,000 individuals indicated that single nucleotide variants (SNVs) in the gene encoding the actin cytoskeletal regulator tropomyosin 4 (TPM4) exert an effect on the count and volume of platelets. Platelet number and volume are independent risk factors for heart attack and stroke. Here, we have identified 2 unrelated families in the BRIDGE Bleeding and Platelet Disorders (BPD) collection who carry a TPM4 variant that causes truncation of the TPM4 protein and segregates with macrothrombocytopenia, a disorder characterized by low platelet count. N-Ethyl-N-nitrosourea-induced (ENU-induced) missense mutations in Tpm4 or targeted inactivation of the Tpm4 locus led to gene dosage-dependent macrothrombocytopenia in mice. All other blood cell counts in Tpm4-deficient mice were normal. Insufficient TPM4 expression in human and mouse megakaryocytes resulted in a defect in the terminal stages of platelet production and had a mild effect on platelet function. Together, our findings demonstrate a nonredundant role for TPM4 in platelet biogenesis in humans and mice and reveal that truncating variants in TPM4 cause a previously undescribed dominant Mendelian platelet disorder.The research participants were enrolled in the Biomedical Research Centres/Units Inherited Diseases Genetic Evaluation (BRIDGE) Bleeding and Platelet Disorders (BPD) study (UK REC10/H0304/66). We are grateful to all the donors who allowed us to use their samples for this study. We thank Sofia Papadia from the NIHR BioResource for organizing the recalls of BRIDGE-BPD participants. The genome sequencing of the BRIDGE-BPD participants was supported by the NIHR BioResource–Rare Diseases (to ET, KD, and WHO). The NIHR BioResource–Rare Diseases is responsible for the delivery of the rare diseases pilot phase of the 100,000 Genomes Project and is funded by the National Institute for Health Research (NIHR; http://www.nihr.ac.uk). Research in the Ouwehand laboratory also receives funding support from the European Commission, NIHR, Wellcome Trust, Medical Research Council (MRC), and British Heart Foundation under numbers RP-PG-0310-1002 and RG/09/12/28096. SKW is supported by an MRC Clinical Training Fellowship (MR/K023489/1). ADM receives support from the Bristol NIHR Biomedical Research Unit for Cardiovascular Disease. This work was supported by a Project Grant (no. 575535), a Program Grant (no. 1016647), a Fellowship (1063008 to BTK and 1058344 to WSA), Project Grants (to PWG and ECH), and an Independent Research Institutes Infrastructure Support Scheme Grant (no. 361646) from the Australian National Health and Medical Research Council; a fellowship from the Sylvia and Charles Viertel Foundation (to BTK); a start-up grant, a fellowship, and a grant from the German Research Foundation (SFB 688, PL707/1-1 and PL707/2-1 to IP); the Kids’ Cancer Project (to PWG); a Fellowship from the European Hematology Association (to MRT) and the British Heart Foundation (PG/13/77/30375 to MRT); NHS Blood and Transplant (to WHO and MRT); the Australian Cancer Research Fund; and a Victorian State Government Operational Infrastructure Support Grant

Procalcitonin Is Not a Reliable Biomarker of Bacterial Coinfection in People With Coronavirus Disease 2019 Undergoing Microbiological Investigation at the Time of Hospital Admission

Abstract Admission procalcitonin measurements and microbiology results were available for 1040 hospitalized adults with coronavirus disease 2019 (from 48 902 included in the International Severe Acute Respiratory and Emerging Infections Consortium World Health Organization Clinical Characterisation Protocol UK study). Although procalcitonin was higher in bacterial coinfection, this was neither clinically significant (median [IQR], 0.33 [0.11–1.70] ng/mL vs 0.24 [0.10–0.90] ng/mL) nor diagnostically useful (area under the receiver operating characteristic curve, 0.56 [95% confidence interval, .51–.60]).</jats:p

Implementation of corticosteroids in treating COVID-19 in the ISARIC WHO Clinical Characterisation Protocol UK:prospective observational cohort study

BACKGROUND: Dexamethasone was the first intervention proven to reduce mortality in patients with COVID-19 being treated in hospital. We aimed to evaluate the adoption of corticosteroids in the treatment of COVID-19 in the UK after the RECOVERY trial publication on June 16, 2020, and to identify discrepancies in care. METHODS: We did an audit of clinical implementation of corticosteroids in a prospective, observational, cohort study in 237 UK acute care hospitals between March 16, 2020, and April 14, 2021, restricted to patients aged 18 years or older with proven or high likelihood of COVID-19, who received supplementary oxygen. The primary outcome was administration of dexamethasone, prednisolone, hydrocortisone, or methylprednisolone. This study is registered with ISRCTN, ISRCTN66726260. FINDINGS: Between June 17, 2020, and April 14, 2021, 47 795 (75·2%) of 63 525 of patients on supplementary oxygen received corticosteroids, higher among patients requiring critical care than in those who received ward care (11 185 [86·6%] of 12 909 vs 36 415 [72·4%] of 50 278). Patients 50 years or older were significantly less likely to receive corticosteroids than those younger than 50 years (adjusted odds ratio 0·79 [95% CI 0·70–0·89], p=0·0001, for 70–79 years; 0·52 [0·46–0·58], p80 years), independent of patient demographics and illness severity. 84 (54·2%) of 155 pregnant women received corticosteroids. Rates of corticosteroid administration increased from 27·5% in the week before June 16, 2020, to 75–80% in January, 2021. INTERPRETATION: Implementation of corticosteroids into clinical practice in the UK for patients with COVID-19 has been successful, but not universal. Patients older than 70 years, independent of illness severity, chronic neurological disease, and dementia, were less likely to receive corticosteroids than those who were younger, as were pregnant women. This could reflect appropriate clinical decision making, but the possibility of inequitable access to life-saving care should be considered. FUNDING: UK National Institute for Health Research and UK Medical Research Council