1
|
Statistical analysis plan for the replacing protein via enteral nutrition in a stepwise approach in critically ill patients (REPLENISH) randomized clinical trial. Trials 2024; 25:296. [PMID: 38698442 PMCID: PMC11064302 DOI: 10.1186/s13063-024-08105-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 04/10/2024] [Indexed: 05/05/2024] Open
Abstract
BACKGROUND The optimal amount and timing of protein intake in critically ill patients are unknown. REPLENISH (Replacing Protein via Enteral Nutrition in a Stepwise Approach in Critically Ill Patients) trial evaluates whether supplemental enteral protein added to standard enteral nutrition to achieve a high amount of enteral protein given from ICU day five until ICU discharge or ICU day 90 as compared to no supplemental enteral protein to achieve a moderate amount of enteral protein would reduce all-cause 90-day mortality in adult critically ill mechanically ventilated patients. METHODS In this multicenter randomized trial, critically ill patients will be randomized to receive supplemental enteral protein (1.2 g/kg/day) added to standard enteral nutrition to achieve a high amount of enteral protein (range of 2-2.4 g/kg/day) or no supplemental enteral protein to achieve a moderate amount of enteral protein (0.8-1.2 g/kg/day). The primary outcome is 90-day all-cause mortality; other outcomes include functional and health-related quality-of-life assessments at 90 days. The study sample size of 2502 patients will have 80% power to detect a 5% absolute risk reduction in 90-day mortality from 30 to 25%. Consistent with international guidelines, this statistical analysis plan specifies the methods for evaluating primary and secondary outcomes and subgroups. Applying this statistical analysis plan to the REPLENISH trial will facilitate unbiased analyses of clinical data. CONCLUSION Ethics approval was obtained from the institutional review board, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia (RC19/414/R). Approvals were also obtained from the institutional review boards of each participating institution. Our findings will be disseminated in an international peer-reviewed journal and presented at relevant conferences and meetings. TRIAL REGISTRATION ClinicalTrials.gov, NCT04475666 . Registered on July 17, 2020.
Collapse
|
2
|
Replacing protein via enteral nutrition in a stepwise approach in critically ill patients: the REPLENISH randomized clinical trial protocol. Trials 2023; 24:485. [PMID: 37518058 PMCID: PMC10388494 DOI: 10.1186/s13063-023-07507-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 07/11/2023] [Indexed: 08/01/2023] Open
Abstract
BACKGROUND Protein intake is recommended in critically ill patients to mitigate the negative effects of critical illness-induced catabolism and muscle wasting. However, the optimal dose of enteral protein remains unknown. We hypothesize that supplemental enteral protein (1.2 g/kg/day) added to standard enteral nutrition formula to achieve high amount of enteral protein (range 2-2.4 g/kg/day) given from ICU day 5 until ICU discharge or ICU day 90 as compared to no supplemental enteral protein to achieve moderate amount enteral protein (0.8-1.2 g/kg/day) would reduce all-cause 90-day mortality in adult critically ill mechanically ventilated patients. METHODS The REPLENISH (Replacing Protein Via Enteral Nutrition in a Stepwise Approach in Critically Ill Patients) trial is an open-label, multicenter randomized clinical trial. Patients will be randomized to the supplemental protein group or the control group. Patients in both groups will receive the primary enteral formula as per the treating team, which includes a maximum protein 1.2 g/kg/day. The supplemental protein group will receive, in addition, supplemental protein at 1.2 g/kg/day starting the fifth ICU day. The control group will receive the primary formula without supplemental protein. The primary outcome is 90-day all-cause mortality. Other outcomes include functional and quality of life assessments at 90 days. The trial will enroll 2502 patients. DISCUSSION The study has been initiated in September 2021. Interim analysis is planned at one third and two thirds of the target sample size. The study is expected to be completed by the end of 2025. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT04475666 . Registered on July 17, 2020.
Collapse
|
3
|
Tocilizumab Outcomes in Critically Ill COVID-19 Patients Admitted to the ICU and the Role of Non-Tocilizumab COVID-19-Specific Medical Therapeutics. J Clin Med 2023; 12:jcm12062301. [PMID: 36983304 PMCID: PMC10053430 DOI: 10.3390/jcm12062301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 02/15/2023] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
Background: Tocilizumab is a monoclonal antibody proposed to manage cytokine release syndrome (CRS) associated with severe COVID-19. Previously published reports have shown that tocilizumab may improve the clinical outcomes of critically ill patients admitted to the ICU. However, no precise data about the role of other medical therapeutics concurrently used for COVID-19 on this outcome have been published. Objectives: We aimed to compare the overall outcome of critically ill COVID-19 patients admitted to the ICU who received tocilizumab with the outcome of matched patients who did not receive tocilizumab while controlling for other confounders, including medical therapeutics for critically ill patients admitted to ICUs. Methods: A prospective, observational, multicenter cohort study was conducted among critically ill COVID-19 patients admitted to the ICU of 14 hospitals in Saudi Arabia between 1 March 2020, and October 31, 2020. Propensity-score matching was utilized to compare patients who received tocilizumab to patients who did not. In addition, the log-rank test was used to compare the 28 day hospital survival of patients who received tocilizumab with those who did not. Then, a multivariate logistic regression analysis of the matched groups was performed to evaluate the impact of the remaining concurrent medical therapeutics that could not be excluded via matching 28 day hospital survival rates. The primary outcome measure was patients’ overall 28 day hospital survival, and the secondary outcomes were ICU length of stay and ICU survival to hospital discharge. Results: A total of 1470 unmatched patients were included, of whom 426 received tocilizumab. The total number of propensity-matched patients was 1278. Overall, 28 day hospital survival revealed a significant difference between the unmatched non-tocilizumab group (586; 56.1%) and the tocilizumab group (269; 63.1%) (p-value = 0.016), and this difference increased even more in the propensity-matched analysis between the non-tocilizumab group (466.7; 54.6%) and the tocilizumab group (269; 63.1%) (p-value = 0.005). The matching model successfully matched the two groups’ common medical therapeutics used to treat COVID-19. Two medical therapeutics remained significantly different, favoring the tocilizumab group. A multivariate logistic regression was performed for the 28 day hospital survival in the propensity-matched patients. It showed that neither steroids (OR: 1.07 (95% CI: 0.75–1.53)) (p = 0.697) nor favipiravir (OR: 1.08 (95% CI: 0.61–1.9)) (p = 0.799) remained as a predictor for an increase in 28 day survival. Conclusion: The tocilizumab treatment in critically ill COVID-19 patients admitted to the ICU improved the overall 28 day hospital survival, which might not be influenced by the concurrent use of other COVID-19 medical therapeutics, although further research is needed to confirm this.
Collapse
|
4
|
Impact of a national collaborative project to improve the care of mechanically ventilated patients. PLoS One 2023; 18:e0280744. [PMID: 36716310 PMCID: PMC9886257 DOI: 10.1371/journal.pone.0280744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 12/19/2022] [Indexed: 02/01/2023] Open
Abstract
This prospective quasi-experimental study from the NASAM (National Approach to Standardize and Improve Mechanical Ventilation) collaborative assessed the impact of evidence-based practices including subglottic suctioning, daily assessment for spontaneous awakening trial (SAT), spontaneous breathing trial (SBT), head of bed elevation, and avoidance of neuromuscular blockers unless otherwise indicated. The study outcomes included VAE (primary) and intensive care unit (ICU) mortality. Changes in daily care process measures and outcomes were evaluated using repeated measures mixed modeling. The results were reported as incident rate ratio (IRR) for each additional month with 95% confidence interval (CI). A comprehensive program that included education on evidence-based practices for optimal care of mechanically ventilated patients with real-time benchmarking of daily care process measures to drive improvement in forty-two ICUs from 26 hospitals in Saudi Arabia (>27,000 days of observation). Compliance with subglottic suctioning, SAT and SBT increased monthly during the project by 3.5%, 2.1% and 1.9%, respectively (IRR 1.035, 95%CI 1.007-1.064, p = 0.0148; 1.021, 95% CI 1.010-1.032, p = 0.0003; and 1.019, 95%CI 1.009-1.029, p = 0.0001, respectively). The use of neuromuscular blockers decreased monthly by 2.5% (IRR 0.975, 95%CI 0.953-0.998, p = 0.0341). The compliance with head of bed elevation was high at baseline and did not change over time. Based on data for 83153 ventilator days, VAE rate was 15.2/1000 ventilator day (95%CI 12.6-18.1) at baseline and did not change during the project (IRR 1.019, 95%CI 0.985-1.053, p = 0.2812). Based on data for 8523 patients; the mortality was 30.4% (95%CI 27.4-33.6) at baseline, and decreased monthly during the project by 1.6% (IRR 0.984, 95%CI 0.973-0.996, p = 0.0067). A national quality improvement collaborative was associated with improvements in daily care processes. These changes were associated with a reduction in mortality but not VAEs. Registration The study is registered in clinicaltrials.gov (NCT03790150).
Collapse
|
5
|
Effect of Helmet Noninvasive Ventilation vs Usual Respiratory Support on Mortality Among Patients With Acute Hypoxemic Respiratory Failure Due to COVID-19: The HELMET-COVID Randomized Clinical Trial. JAMA 2022; 328:1063-1072. [PMID: 36125473 PMCID: PMC9490511 DOI: 10.1001/jama.2022.15599] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
IMPORTANCE Helmet noninvasive ventilation has been used in patients with COVID-19 with the premise that helmet interface is more effective than mask interface in delivering prolonged treatments with high positive airway pressure, but data about its effectiveness are limited. OBJECTIVE To evaluate whether helmet noninvasive ventilation compared with usual respiratory support reduces mortality in patients with acute hypoxemic respiratory failure due to COVID-19 pneumonia. DESIGN, SETTING, AND PARTICIPANTS This was a multicenter, pragmatic, randomized clinical trial that was conducted in 8 sites in Saudi Arabia and Kuwait between February 8, 2021, and November 16, 2021. Adult patients with acute hypoxemic respiratory failure (n = 320) due to suspected or confirmed COVID-19 were included. The final follow-up date for the primary outcome was December 14, 2021. INTERVENTIONS Patients were randomized to receive helmet noninvasive ventilation (n = 159) or usual respiratory support (n = 161), which included mask noninvasive ventilation, high-flow nasal oxygen, and standard oxygen. MAIN OUTCOMES AND MEASURES The primary outcome was 28-day all-cause mortality. There were 12 prespecified secondary outcomes, including endotracheal intubation, barotrauma, skin pressure injury, and serious adverse events. RESULTS Among 322 patients who were randomized, 320 were included in the primary analysis, all of whom completed the trial. Median age was 58 years, and 187 were men (58.4%). Within 28 days, 43 of 159 patients (27.0%) died in the helmet noninvasive ventilation group compared with 42 of 161 (26.1%) in the usual respiratory support group (risk difference, 1.0% [95% CI, -8.7% to 10.6%]; relative risk, 1.04 [95% CI, 0.72-1.49]; P = .85). Within 28 days, 75 of 159 patients (47.2%) required endotracheal intubation in the helmet noninvasive ventilation group compared with 81 of 161 (50.3%) in the usual respiratory support group (risk difference, -3.1% [95% CI, -14.1% to 7.8%]; relative risk, 0.94 [95% CI, 0.75-1.17]). There were no significant differences between the 2 groups in any of the prespecified secondary end points. Barotrauma occurred in 30 of 159 patients (18.9%) in the helmet noninvasive ventilation group and 25 of 161 (15.5%) in the usual respiratory support group. Skin pressure injury occurred in 5 of 159 patients (3.1%) in the helmet noninvasive ventilation group and 10 of 161 (6.2%) in the usual respiratory support group. There were 2 serious adverse events in the helmet noninvasive ventilation group and 1 in the usual respiratory support group. CONCLUSIONS AND RELEVANCE Results of this study suggest that helmet noninvasive ventilation did not significantly reduce 28-day mortality compared with usual respiratory support among patients with acute hypoxemic respiratory failure due to COVID-19 pneumonia. However, interpretation of the findings is limited by imprecision in the effect estimate, which does not exclude potentially clinically important benefit or harm. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT04477668.
Collapse
|
6
|
Favipiravir Efficacy And Safety For The Treatment Of Severe Coronavirus Disease 2019: A Retrospective Study. J Ayub Med Coll Abbottabad 2022; 34:397-402. [PMID: 36377144 DOI: 10.55519/jamc-03-10305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
BACKGROUND Corona virus disease is caused by the enveloped, single stranded RNA virus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) becoming the deadliest disease of the century. Its global outbreak has led researchers to develop drugs or vaccines to prevent the spread of the disease. Favipiravir is an approved orally administered antiviral drug that selectively inhibits RNA-dependent RNA polymerase, used off-label to treat COVID-19. Objectives: The purpose of this study was to assess the efficacy and safety of this drug for severe COVID-19 infection. METHODS This was an observational retrospective study, carried out at the ICU of King Saud Medical City (KSMC) from June 2020 to August 2020. Including a total of one thousand six hundred and ninety-nine patients (n=1699). Categorized into a treatment group (193 patients) who received Favipiravir along with standard care, and non-treatment group (1506 patients) who received standard care only. RESULTS ICU all-cause mortality was similar in both groups i.e., (Treated group 38.3% Vs Untreated group 39.4%, 95% CI of difference: -6.6% to +8.4%; p = 0.8). The subgroup analysis of survivors as compared to deceased in the treatment group showed that survivors had significantly lower age, international normalising ratio (INR), blood urea nitrogen (BUN), and creatinine. The mean ICU length of stay (LOS) was shorter for survivors compared to deceased (11.2± 8.03 Vs 16.7±9.8 days respectively), while hospital LOS was almost similar between the two groups. Advanced age (OR 1.03 [95% CI: 1.01-1.06]; p=0.004), higher INR and BUN were significantly associated with increased odds of mortality. Comparison of lab investigations at day 1 and day 10 in the treatment group (regardless of outcome) showed that there was a significant increase in Alanine transaminase (ALT), alkaline phosphatase (ALK), and Bilirubin, while an insignificant trend of increase in Aspartate transaminase (AST) and creatinine was recorded. CONCLUSIONS In this study, Favipiravir showed better therapeutic responses in patients with severe COVID-19 infection, in terms of average duration of stay in the intensive care unit and was well tolerated in the younger age, but showed no mortality benefit. However, elevated levels of inflammatory markers, including increased ALT, AST, BUN, bilirubin, and creatinine, needs to be carefully examined.
Collapse
|
7
|
Machine learning decision tree algorithm role for predicting mortality in critically ill adult COVID-19 patients admitted to the ICU. J Infect Public Health 2022; 15:826-834. [PMID: 35759808 PMCID: PMC9212964 DOI: 10.1016/j.jiph.2022.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 06/02/2022] [Accepted: 06/14/2022] [Indexed: 11/17/2022] Open
Abstract
Background Coronavirus disease-19 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is currently a major cause of intensive care unit (ICU) admissions globally. The role of machine learning in the ICU is evolving but currently limited to diagnostic and prognostic values. A decision tree (DT) algorithm is a simple and intuitive machine learning method that provides sequential nonlinear analysis of variables. It is simple and might be a valuable tool for bedside physicians during COVID-19 to predict ICU outcomes and help in critical decision-making like end-of-life decisions and bed allocation in the event of limited ICU bed capacities. Herein, we utilized a machine learning DT algorithm to describe the association of a predefined set of variables and 28-day ICU outcome in adult COVID-19 patients admitted to the ICU. We highlight the value of utilizing a machine learning DT algorithm in the ICU at the time of a COVID-19 pandemic. Methods This was a prospective and multicenter cohort study involving 14 hospitals in Saudi Arabia. We included critically ill COVID-19 patients admitted to the ICU between March 1, 2020, and October 31, 2020. The predictors of 28-day ICU mortality were identified using two predictive models: conventional logistic regression and DT analyses. Results There were 1468 critically ill COVID-19 patients included in the study. The 28-day ICU mortality was 540 (36.8 %), and the 90-day mortality was 600 (40.9 %). The DT algorithm identified five variables that were integrated into the algorithm to predict 28-day ICU outcomes: need for intubation, need for vasopressors, age, gender, and PaO2/FiO2 ratio. Conclusion DT is a simple tool that might be utilized in the ICU to identify critically ill COVID-19 patients who are at high risk of 28-day ICU mortality. However, further studies and external validation are still required.
Collapse
|
8
|
Helmet noninvasive ventilation for COVID-19 patients (Helmet-COVID): statistical analysis plan for a randomized controlled trial. Trials 2022; 23:105. [PMID: 35109898 PMCID: PMC8808278 DOI: 10.1186/s13063-021-05988-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 12/27/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Noninvasive respiratory support is frequently needed for patients with acute hypoxemic respiratory failure due to coronavirus disease 19 (COVID-19). Helmet noninvasive ventilation has multiple advantages over other oxygen support modalities but data about effectiveness are limited. METHODS In this multicenter randomized trial of helmet noninvasive ventilation for COVID-19 patients, 320 adult ICU patients (aged ≥14 years or as per local standards) with suspected or confirmed COVID-19 and acute hypoxemic respiratory failure (ratio of arterial oxygen partial pressure to fraction of inspired oxygen < 200 despite supplemental oxygen with a partial/non-rebreathing mask at a flow rate of 10 L/min or higher) will be randomized to helmet noninvasive ventilation with usual care or usual care alone, which may include mask noninvasive ventilation, high-flow nasal oxygen, or standard oxygen therapy. The primary outcome is death from any cause within 28 days after randomization. The trial has 80% power to detect a 15% absolute risk reduction in 28-day mortality from 40 to 25%. The primary outcome will be compared between the helmet and usual care group in the intention-to-treat using the chi-square test. Results will be reported as relative risk and 95% confidence interval. The first patient was enrolled on February 8, 2021. As of August 1, 2021, 252 patients have been enrolled from 7 centers in Saudi Arabia and Kuwait. DISCUSSION We developed a detailed statistical analysis plan to guide the analysis of the Helmet-COVID trial, which is expected to conclude enrollment in November 2021. TRIAL REGISTRATION ClinicalTrials.gov NCT04477668 . Registered on July 20, 2020.
Collapse
|
9
|
Comparison of severity of immunized versus non-immunized COVID-19 patients admitted to ICU: A prospective observational study. Ann Med Surg (Lond) 2021; 71:102951. [PMID: 34667593 PMCID: PMC8518130 DOI: 10.1016/j.amsu.2021.102951] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 12/20/2022] Open
Abstract
Background Vaccines against COVID-19 show high efficacy, yet, infection is still being detected among immunized patients, although with blunted severity. The purpose of this study was to assess the severity of COVID-19 infection among immunized versus non-immunized COVID-19 patients admitted to ICU. Method A prospective observational cohort study, including all COVID-19 patients admitted to intensive care unit between January 1st, 2021 and June 30th, 2021 were eligible for inclusion. A comparison of severity upon hospitalization of immunized versus non-immunized patients on a 7-level ordinal scale was conducted, using ordinal logistic regression. Results 592 patients were enrolled, 524 (88.5%) non-immunized, 63 (10.6%) partially immunized, and 5 (0.9%) fully immunized, partially and fully immunized patients were grouped together. Majority of immunized patients (86.7%) were symptomatic before 21 days of immunization. Non-immunized group had fewer patients in the lower severity categories, while more patients in the higher severity categories compared to immunized group. At least one dose of immunization was associated with reduction of odds of moving up severity scale (OR = 0.2 [95% CI: 0.15–0.4]; p < 0.001) in a well fitted ordinal logistic regression model. At least one dose of immunization was associated with lower adjusted odds of 30 day all-cause mortality (OR = 0.45 [95% CI: 0.23–0.89]; p = 0.02). Non-immunized group had higher mortality rate (43.9% versus 29.4% [95% CI: 1.5 to 25.8]; p = 0.02). Conclusion Most COVID-19 patients admitted to ICU were non-immunized, most of the partially immunized patients got infected before immunity could develop, and fully immunized patients were likely non-responders. At least one dose of immunization significantly decreases severity of the disease across all ordinal severity categories, and is significantly associated with lower 30 day all-cause mortality. Accordingly, immunization status may have to be considered when deciding on disposition of COVID-19 patients at the point of triage. Vaccines against COVID-19 show high efficacy in preventing hospitalization and death. In our report most COVID-19 patients admitted to ICU were non-immunized. At least one dose of immunization significantly decreases severity of the disease. Partially immunized patients get infected before immunity could develop. Fully immunized patients were likely non-responders.
Collapse
|
10
|
Al
2
O
3
and
CuO
nanoparticles as promising additives to improve the properties of
KCl
‐polymer mud: An experimental investigation. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.24285] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
11
|
Abstract
INTRODUCTION Non-invasive ventilation (NIV) delivered by helmet has been used for respiratory support of patients with acute hypoxaemic respiratory failure due to COVID-19 pneumonia. The aim of this study was to compare helmet NIV with usual care versus usual care alone to reduce mortality. METHODS AND ANALYSIS This is a multicentre, pragmatic, parallel randomised controlled trial that compares helmet NIV with usual care to usual care alone in a 1:1 ratio. A total of 320 patients will be enrolled in this study. The primary outcome is 28-day all-cause mortality. The primary outcome will be compared between the two study groups in the intention-to-treat and per-protocol cohorts. An interim analysis will be conducted for both safety and effectiveness. ETHICS AND DISSEMINATION Approvals are obtained from the institutional review boards of each participating institution. Our findings will be published in peer-reviewed journals and presented at relevant conferences and meetings. TRIAL REGISTRATION NUMBER NCT04477668.
Collapse
|
12
|
Role of phenazine-enzyme physiology for current generation in a bioelectrochemical system. Microb Biotechnol 2021; 14:1613-1626. [PMID: 34000093 PMCID: PMC8313257 DOI: 10.1111/1751-7915.13827] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/14/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023] Open
Abstract
Pseudomonas aeruginosa produces phenazine-1-carboxylic acid (PCA) and pyocyanin (PYO), which aid its anaerobic survival by mediating electron transfer to distant oxygen. These natural secondary metabolites are being explored in biotechnology to mediate electron transfer to the anode of bioelectrochemical systems. A major challenge is that only a small fraction of electrons from microbial substrate conversion is recovered. It remained unclear whether phenazines can re-enter the cell and thus, if the electrons accessed by the phenazines arise mainly from cytoplasmic or periplasmic pathways. Here, we prove that the periplasmic glucose dehydrogenase (Gcd) of P. aeruginosa and P. putida is involved in the reduction of natural phenazines. PYO displayed a 60-fold faster enzymatic reduction than PCA; PCA was, however, more stable for long-term electron shuttling to the anode. Evaluation of a Gcd knockout and overexpression strain showed that up to 9% of the anodic current can be designated to this enzymatic reaction. We further assessed phenazine uptake with the aid of two molecular biosensors, which experimentally confirm the phenazines' ability to re-enter the cytoplasm. These findings significantly advance the understanding of the (electro) physiology of phenazines for future tailoring of phenazine electron discharge in biotechnological applications.
Collapse
|
13
|
Critically ill patients with diabetes and Middle East respiratory syndrome: a multi-center observational study. BMC Infect Dis 2021; 21:84. [PMID: 33468070 PMCID: PMC7814976 DOI: 10.1186/s12879-021-05771-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 01/06/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Diabetes is a risk factor for infection with coronaviruses. This study describes the demographic, clinical data, and outcomes of critically ill patients with diabetes and Middle East Respiratory Syndrome (MERS). METHODS This retrospective cohort study was conducted at 14 hospitals in Saudi Arabia (September 2012-January 2018). We compared the demographic characteristics, underlying medical conditions, presenting symptoms and signs, management and clinical course, and outcomes of critically ill patients with MERS who had diabetes compared to those with no diabetes. Multivariable logistic regression analysis was performed to determine if diabetes was an independent predictor of 90-day mortality. RESULTS Of the 350 critically ill patients with MERS, 171 (48.9%) had diabetes. Patients with diabetes were more likely to be older, and have comorbid conditions, compared to patients with no diabetes. They were more likely to present with respiratory failure requiring intubation, vasopressors, and corticosteroids. The median time to clearance of MERS-CoV RNA was similar (23 days (Q1, Q3: 17, 36) in patients with diabetes and 21.0 days (Q1, Q3: 10, 33) in patients with no diabetes). Mortality at 90 days was higher in patients with diabetes (78.9% versus 54.7%, p < 0.0001). Multivariable regression analysis showed that diabetes was an independent risk factor for 90-day mortality (odds ratio, 2.09; 95% confidence interval, 1.18-3.72). CONCLUSIONS Half of the critically ill patients with MERS have diabetes; which is associated with more severe disease. Diabetes is an independent predictor of mortality among critically patients with MERS.
Collapse
|
14
|
Tocilizumab in the treatment of rapidly evolving COVID-19 pneumonia and multifaceted critical illness: A retrospective case series. Ann Med Surg (Lond) 2020; 60:417-424. [PMID: 33169088 PMCID: PMC7642808 DOI: 10.1016/j.amsu.2020.10.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/23/2020] [Accepted: 10/23/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND COVID-19 associated critical illness characterized by rapidly evolving acute respiratory failure (ARF) can develop, especially on the grounds of hyperinflammation. AIM AND METHODS A case-series of 61 patients admitted to our intensive care unit (ICU) between August 12 and September 12, 2020 with confirmed COVID-19 pneumonia and rapidly evolving ARF requiring oxygen support therapy and/or mechanical ventilation was retrospectively analyzed. We examined whether intravenous administration of tocilizumab, a monoclonal interleukin-6 receptor antibody, was associated with improved outcome. All patients received empiric antivirals, dexamethasone 6 mg/day for 7 days, antibiotics, and prophylactic anticoagulation. Tocilizumab was administered at a dosage of 8 mg/kg [two consecutive intravenous infusions 12 h apart]. Outcome measures such as mortality on day-14, ICU length of stay, and rate of nosocomial acquired bacterial infections were also analyzed. Results: Patients were males (88.2%) aged 51 [interquartile range (IQR): 42.5-58.75)], with admission Acute Physiology and Chronic Health Evaluation (APACHE) 4 score of 53 (IQR: 37.75-72.5), and had more than one comorbidity (62.3%). On admission, twenty nine patients (47.5%) were mechanically ventilated, and thirty two patients (52.5%) were receiving oxygen therapy. No serious adverse effects due to tocilizumab therapy were recorded. However, twelve patients (19.6%) developed nosocomial acquired infections. ICU length of stay was 13 (IQR: 9-17) days, and mortality on day-14 was 24.6%. Six patients were shifted to other hospitals but were followed-up. The overall mortality on day-30 was 31.1%. Non-mechanically ventilated patients had higher survival rates compared to mechanically ventilated patients although results were not significant [hazards ratio = 2.6 (95% confidence intervals: 0.9-7.7), p = 0.08]. Tocilizumab did not affect the mortality of critically ill COVID-19 patients. CONCLUSION Tocilizumab could be an adjunct safe therapy in rapidly evolving COVID-19 pneumonia and associated critical illness.
Collapse
|
15
|
Ribavirin and Interferon Therapy for Critically Ill Patients With Middle East Respiratory Syndrome: A Multicenter Observational Study. Clin Infect Dis 2020; 70:1837-1844. [PMID: 31925415 PMCID: PMC7108209 DOI: 10.1093/cid/ciz544] [Citation(s) in RCA: 177] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 06/21/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The objective of this study was to evaluate the effect of ribavirin and recombinant interferon (RBV/rIFN) therapy on the outcomes of critically ill patients with Middle East respiratory syndrome (MERS), accounting for time-varying confounders. METHODS This is a retrospective cohort study of critically ill patients with laboratory-confirmed MERS from 14 hospitals in Saudi Arabia diagnosed between September 2012 and January 2018. We evaluated the association of RBV/rIFN with 90-day mortality and MERS coronavirus (MERS-CoV) RNA clearance using marginal structural modeling to account for baseline and time-varying confounders. RESULTS Of 349 MERS patients, 144 (41.3%) patients received RBV/rIFN (RBV and/or rIFN-α2a, rIFN-α2b, or rIFN-β1a; none received rIFN-β1b). RBV/rIFN was initiated at a median of 2 days (Q1, Q3: 1, 3 days) from intensive care unit admission. Crude 90-day mortality was higher in patients with RBV/rIFN compared to no RBV/rIFN (106/144 [73.6%] vs 126/205 [61.5%]; P = .02]. After adjusting for baseline and time-varying confounders using a marginal structural model, RBV/rIFN was not associated with changes in 90-day mortality (adjusted odds ratio, 1.03 [95% confidence interval {CI}, .73-1.44]; P = .87) or with more rapid MERS-CoV RNA clearance (adjusted hazard ratio, 0.65 [95% CI, .30-1.44]; P = .29). CONCLUSIONS In this observational study, RBV/rIFN (RBV and/or rIFN-α2a, rIFN-α2b, or rIFN-β1a) therapy was commonly used in critically ill MERS patients but was not associated with reduction in 90-day mortality or in faster MERS-CoV RNA clearance.
Collapse
|
16
|
Abstract 3404: Inhibition of BCL10-MALT1 interaction to treat diffuse large B-cell lymphoma. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-3404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The CARMA1/BCL10/MALT1 (CBM) signaling complex mediates antigen receptor-induced activation of NF-kB in lymphocytes to support normal adaptive immunity. As the effector protein of the complex, MALT1 exhibits two activities: protease and scaffolding activities. Gain-of-function mutations in the CARMA1 moiety or its upstream regulators trigger antigen-independent assembly of oligomeric CBM complexes, leading to constitutive activation of MALT1, unregulated NF-kB activity, and development of Activated B-Cell subtype of Diffuse Large B-Cell Lymphoma (ABC-DLBCL). Existing MALT1 inhibitors block only MALT1 protease activity, causing incomplete and unbalanced inhibition of MALT1, and have the potential for inducing autoimmune side effects. Since MALT1 is recruited to the CBM complex via its interaction with BCL10, we sought to identify inhibitors of BCL10-MALT1 interaction in order to target both the protease and scaffolding activities of MALT1 to treat ABC-DLBCL.
Our previous work suggested that an antibody-epitope-like interface governs the interaction between BCL10 and MALT1, so that a therapeutic opportunity exists for developing a small molecule inhibitor of the interaction to terminate inappropriate CBM activity. Using co-immunoprecipitation studies, a mammalian two-hybrid system, and surface plasmon resonance (SPR), we confirmed that BCL10 residues 107-119 and the tandem Ig-like domains of MALT1 are critical for this interaction. We then performed a structure-guided in silico screen of 3 million compounds, based on a computational model of the BCL10-MALT1 interaction interface, to identify compounds with potential for disrupting the interaction.
Compound 1 from the initial screening hits showed dose-responsive inhibition of BCL10-MALT1 interaction in both SPR and ELISA-based assays. Functionally, Compound 1 inhibits both MALT1 protease and scaffolding activities in Jurkat T cells, as demonstrated by its inhibition of CD3/CD28-induced RelB and N4BP1 cleavage, and inhibition of IKK phosphorylation, respectively. Compound 1 also blocks IL-2 transcription and IL-2 secretion by PMA/ionomycin-treated Jurkat T cells, as well as constitutive CBM-dependent secretion of IL-6 and IL-10 by ABC-DLBCL cells. Accordingly, Compound 1 selectively suppresses the growth of ABC-DLBCL cell lines, but does not affect the growth of MALT1-independent GCB-DLBCL cell lines.
In conclusion, we have identified an early-stage small molecule compound that inhibits the BCL10-MALT1 interaction, MALT1 protease and scaffolding activities, downstream CBM-dependent signaling, and ABC-DLBCL cell growth. Structure-guided modification of this lead compound is underway to further develop a new class of protein-protein interaction inhibitors that could provide more efficacious blockade of MALT1, while offering protection from undesirable autoimmune side effects in the treatment of this aggressive form of lymphoma.
Citation Format: Heejae Kang, Dong Hu, Marcelo Murai, Ahmed Mady, Bill Chen, Zaneta Nikolovska-Coleska, Linda M. McAllister-Lucas, Peter C. Lucas. Inhibition of BCL10-MALT1 interaction to treat diffuse large B-cell lymphoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3404.
Collapse
|
17
|
Treatment of Middle East respiratory syndrome with a combination of lopinavir/ritonavir and interferon-β1b (MIRACLE trial): statistical analysis plan for a recursive two-stage group sequential randomized controlled trial. Trials 2020; 21:8. [PMID: 31900204 PMCID: PMC6942374 DOI: 10.1186/s13063-019-3846-x] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 10/24/2019] [Indexed: 11/17/2022] Open
Abstract
The MIRACLE trial (MERS-CoV Infection tReated with A Combination of Lopinavir/ritonavir and intErferon-β1b) investigates the efficacy of a combination therapy of lopinavir/ritonavir and recombinant interferon-β1b provided with standard supportive care, compared to placebo provided with standard supportive care, in hospitalized patients with laboratory-confirmed MERS. The MIRACLE trial is designed as a recursive, two-stage, group sequential, multicenter, placebo-controlled, double-blind randomized controlled trial. The aim of this article is to describe the statistical analysis plan for the MIRACLE trial. The primary outcome is 90-day mortality. The primary analysis will follow the intention-to-treat principle. The MIRACLE trial is the first randomized controlled trial for MERS treatment. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02845843. Registered on 27 July 2016.
Collapse
|
18
|
MON-PO611: Vitamin D Status and Inflammatory Bio-Markers in Critically Ill Patients with Sepsis. Clin Nutr 2019. [DOI: 10.1016/s0261-5614(19)32444-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
19
|
Corticosteroid Therapy for Critically Ill Patients with Middle East Respiratory Syndrome. Am J Respir Crit Care Med 2019; 197:757-767. [PMID: 29161116 DOI: 10.1164/rccm.201706-1172oc] [Citation(s) in RCA: 762] [Impact Index Per Article: 152.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
RATIONALE Corticosteroid therapy is commonly used among critically ill patients with Middle East Respiratory Syndrome (MERS), but its impact on outcomes is uncertain. Analyses of observational studies often do not account for patients' clinical condition at the time of corticosteroid therapy initiation. OBJECTIVES To investigate the association of corticosteroid therapy on mortality and on MERS coronavirus RNA clearance in critically ill patients with MERS. METHODS ICU patients with MERs were included from 14 Saudi Arabian centers between September 2012 and October 2015. We performed marginal structural modeling to account for baseline and time-varying confounders. MEASUREMENTS AND MAIN RESULTS Of 309 patients, 151 received corticosteroids. Corticosteroids were initiated at a median of 3.0 days (quartile 1 [Q1]-Q3, 1.0-7.0) from ICU admission. Patients who received corticosteroids were more likely to receive invasive ventilation (141 of 151 [93.4%] vs. 121 of 158 [76.6%]; P < 0.0001) and had higher 90-day crude mortality (112 of 151 [74.2%] vs. 91 of 158 [57.6%]; P = 0.002). Using marginal structural modeling, corticosteroid therapy was not significantly associated with 90-day mortality (adjusted odds ratio, 0.75; 95% confidence interval, 0.52-1.07; P = 0.12) but was associated with delay in MERS coronavirus RNA clearance (adjusted hazard ratio, 0.35; 95% CI, 0.17-0.72; P = 0.005). CONCLUSIONS Corticosteroid therapy in patients with MERS was not associated with a difference in mortality after adjustment for time-varying confounders but was associated with delayed MERS coronavirus RNA clearance. These findings highlight the challenges and importance of adjusting for baseline and time-varying confounders when estimating clinical effects of treatments using observational studies.
Collapse
|
20
|
Noninvasive ventilation in critically ill patients with the Middle East respiratory syndrome. Influenza Other Respir Viruses 2019; 13:382-390. [PMID: 30884185 PMCID: PMC6586182 DOI: 10.1111/irv.12635] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 01/08/2019] [Accepted: 01/21/2019] [Indexed: 12/13/2022] Open
Abstract
Background Noninvasive ventilation (NIV) has been used in patients with the Middle East respiratory syndrome (MERS) with acute hypoxemic respiratory failure, but the effectiveness of this approach has not been studied. Methods Patients with MERS from 14 Saudi Arabian centers were included in this analysis. Patients who were initially managed with NIV were compared to patients who were managed only with invasive mechanical ventilation (invasive MV). Results Of 302 MERS critically ill patients, NIV was used initially in 105 (35%) patients, whereas 197 (65%) patients were only managed with invasive MV. Patients who were managed with NIV initially had lower baseline SOFA score and less extensive infiltrates on chest radiograph compared with patients managed with invasive MV. The vast majority (92.4%) of patients who were managed initially with NIV required intubation and invasive mechanical ventilation, and were more likely to require inhaled nitric oxide compared to those who were managed initially with invasive MV. ICU and hospital length of stay were similar between NIV patients and invasive MV patients. The use of NIV was not independently associated with 90‐day mortality (propensity score‐adjusted odds ratio 0.61, 95% CI [0.23, 1.60] P = 0.27). Conclusions In patients with MERS and acute hypoxemic respiratory failure, NIV failure was very high. The use of NIV was not associated with improved outcomes.
Collapse
|
21
|
Abstract
NASAM (National Approach to Standardize and Improve Mechanical Ventilation) is a national collaborative quality improvement project in Saudi Arabia. It aims to improve the care of mechanically ventilated patients by implementing evidence-based practices with the goal of reducing the rate of ventilator-associated events and therefore reducing mortality, mechanical ventilation duration and intensive care unit (ICU) length of stay. The project plans to extend the implementation to a total of 100 ICUs in collaboration with multiple health systems across the country. As of March 22, 2019, a total of 78 ICUs have registered from 6 different health sectors, 48 hospitals, and 27 cities. The leadership support in all health sectors for NASAM speaks of the commitment to improve the care of mechanically ventilated patients across the kingdom.
Collapse
|
22
|
Critically ill healthcare workers with the middle east respiratory syndrome (MERS): A multicenter study. PLoS One 2018; 13:e0206831. [PMID: 30439974 PMCID: PMC6237307 DOI: 10.1371/journal.pone.0206831] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 10/19/2018] [Indexed: 12/29/2022] Open
Abstract
Background Middle East Respiratory Syndrome Coronavirus (MERS-CoV) leads to healthcare-associated transmission to patients and healthcare workers with potentially fatal outcomes. Aim We aimed to describe the clinical course and functional outcomes of critically ill healthcare workers (HCWs) with MERS. Methods Data on HCWs was extracted from a multi-center retrospective cohort study on 330 critically ill patients with MERS admitted between (9/2012–9/2015). Baseline demographics, interventions and outcomes were recorded and compared between survivors and non-survivors. Survivors were approached with questionnaires to elucidate their functional outcomes using Karnofsky Performance Status Scale. Findings Thirty-Two HCWs met the inclusion criteria. Comorbidities were recorded in 34% (11/32) HCW. Death resulted in 8/32 (25%) HCWs including all 5 HCWs with chronic renal impairment at baseline. Non-surviving HCW had lower PaO2/FiO2 ratios 63.5 (57, 116.2) vs 148 (84, 194.3), p = 0.043, and received more ECMO therapy compared to survivors, 9/32 (28%) vs 4/24 (16.7%) respectively (p = 0.02).Thirteen of the surviving (13/24) HCWs responded to the questionnaire. Two HCWs confirmed functional limitations. Median number of days from hospital discharge until the questionnaires were filled was 580 (95% CI 568, 723.5) days. Conclusion Approximately 10% of critically ill patients with MERS were HCWs. Hospital mortality rate was substantial (25%). Patients with chronic renal impairment represented a particularly high-risk group that should receive extra caution during suspected or confirmed MERS cases clinical care assignment and during outbreaks. Long-term repercussions of critical illness due to MERS on HCWs in particular, and patients in general, remain unknown and should be investigated in larger studies.
Collapse
|
23
|
Abstract 3658: Structure-guided de novo design of selective Mcl-1 Inhibitors: Synthesis, structural and biochemical characterization. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-3658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Myeloid cell leukemia-1 (Mcl-1) is a potent anti-apoptotic protein, member of the prosurvival Bcl-2 family. Amplification of the gene encoding the Mcl-1 protein is a common genetic aberration in human cancer. Overexpression of Mcl-1 is associated with high tumor grade, resistance to chemotherapy and poor prognosis in many types of cancers. Thus Mcl-1 is emerging as a critical survival factor in a broad range of human cancers and represents an attractive molecular target for development of a new class of cancer therapy. There is still need for developing BH3 mimetics that can efficiently and selectively target Mcl-1 protein.
Employing de-novo structure-based drug-design, we have designed a new class of potent small-molecule Mcl-1 inhibitors based on the initial lead compound discovered by high-throughput screening. Analyzing the binding model of this compound with Mcl-1 through computational docking supported by HSQC NMR studies, and using the structural information, we have designed and optimized a class of small-molecule inhibitors of Mcl-1 using a 2-(phenylsulfonamido) benzoic acid as a scaffold to reproduce the key interactions with Mcl-1 such as the conserved hydrogen bond between the aspartate in pro-apoptotic proteins and Arg263 in Mcl-1. Several co-crystal structures of this class inhibitors in complex with Mcl-1 have provided a basis for their further optimization which ultimately led to the discovery of ligands with low-nanomolar potency (Ki = 8 nM) and selectivity for Mcl-1. These compounds bind in the canonical BH3 binding groove. Interestingly, depending on the particular substitution pattern in the core scaffold, a “flip’ binding mode was observed where the substituents bind in a reverse orientation. These findings were confirmed by X-ray crystallography. The most potent compounds were further biologically characterized with a series of complementary biochemical and functional assays.
Citation Format: Ahmed Mady, Lei Miao, Andrej Perdih, Chenzhong Liao, Naval Bajwa, Jeanne Stuckey, Zaneta Nikolovska-Coleska. Structure-guided de novo design of selective Mcl-1 Inhibitors: Synthesis, structural and biochemical characterization. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3658. doi:10.1158/1538-7445.AM2015-3658
Collapse
|
24
|
Abstract 2469: Identification of novel Mcl-1 inhibitors using integrated screening approach: combining high throughput and virtual screening. Cancer Res 2013. [DOI: 10.1158/1538-7445.am2013-2469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Myeloid cell leukemia-1 (Mcl-1) is a potent anti-apoptotic protein, a member of the prosurvival Bcl-2 family, and its role is emerging as a critical survival factor in a broad range of human cancers. Mcl-1 represents a very attractive molecular target for development of a new class of cancer therapy and there is still need for developing BH3 mimetics that can efficiently and selectively target Mcl-1 protein. We employed integrated screening approach through combining high throughput and virtual screening, to identify novel chemical classes as Mcl-1 inhibitors. For this purpose we developed a dual-readout HTS assay that combines two assay technologies, FP and FRET, into one system using the Mcl-1 and labeled Noxa BH3 derived peptide and optimized in a 1,536-well ultra-HTS format. This assay was used for screening a library of 102,255 compounds. As two assay platforms were utilized for the same target simultaneously, hit information was enriched identifying 1214 compounds. To further improve the output and the quality of the identified inhibitors, as well as to incorporate the structure-based knowledge of the interactions between Mcl-1 and number of BH3 peptides, we have integrated in silico target-based screening for selection of the most promising hits for further validation. The complex structure between Mcl-1 and Noxa BH3 peptide (PDB ID: 2NLA) was used for the induced fit docking of 1214 hits. Followed by the scoring and ranking of the identified hits, 62 compounds were selected for further evaluation in a series of complementary biochemical, biophysical and functional assays. Several in vitro binding assays with different platform, FP, SPR, and (HSQC) NMR spectroscopy, were used to determine the binding affinity of the compounds. The binding data revealed that we have identified inhibitors with different selectivity profiles against five members of the Bcl-2 family: Mcl-1, Bcl-2, Bcl-xL, Bcl-w and A1. 15N HSQC spectra conclusively showed that newly identified compounds interact with the BH3 domain in Mcl-1 protein and affect many residues in the BH3 binding groove. Using pull down assay it was demonstrated that the identified compounds were able in a dose dependent manner to disrupt interactions between endogenous Mcl-1 protein and biotin labeled Noxa BH3 peptide. Functional studies showed that compounds can antagonize Mcl-1 function and induce cytochrome c and Smac release from the isolated mitochondria. By using murine embryonic fibroblasts (MEFs), wild type and deficient in both Bax and Bak (double knock out), it was further demonstrated that the cytotoxic activity and induction of apoptosis, depend on Bax and/or Bak, suggesting that the compounds function as BH3 mimetics. Collectively, these findings provide several different chemical classes for further chemical modifications and optimization toward developing a new class of anticancer drugs as Mcl-1 inhibitors.
Citation Format: Ahmed Mady, Chenzhong Liao, Fardokht Abulwerdi, Chenxi Shen, Yuhong Du, Jeanne Stuckey, Haian Fu, Zaneta Nikolovska-Coleska. Identification of novel Mcl-1 inhibitors using integrated screening approach: combining high throughput and virtual screening. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2469. doi:10.1158/1538-7445.AM2013-2469
Collapse
|
25
|
EVALUATION OF SOME RICE (Oryza sativa L.) GENOTYPES UNDER WATER STRESS CONDITIONS. JOURNAL OF PLANT PRODUCTION 2011; 2:307-326. [DOI: 10.21608/jpp.2011.85516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
|
26
|
|
27
|
A theoretical model investigation of the oxygen-electrode processes of an alkaline H2O2 fuel cell. ACTA ACUST UNITED AC 1986. [DOI: 10.1016/0166-1280(86)80058-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|