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1.
Chem Sci ; 15(13): 4860-4870, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38550687

ABSTRACT

Geometric isomerism in mechanically interlocked systems-which arises when the axle of a mechanically interlocked molecule is oriented, and the macrocyclic component is facially dissymmetric-can provide enhanced functionality for directional transport and polymerization catalysis. We now introduce a kinetically controlled strategy to control geometric isomerism in [2]rotaxanes. Our synthesis provides the major geometric isomer with high selectivity, broadening synthetic access to such interlocked structures. Starting from a readily accessible [2]rotaxane with a symmetrical axle, one of the two stoppers is activated selectively for stopper exchange by the substituents on the ring component. High selectivities are achieved in these reactions, based on coupling the selective formation reactions leading to the major products with inversely selective depletion reactions for the minor products. Specifically, in our reaction system, the desired (major) product forms faster in the first step, while the undesired (minor) product subsequently reacts away faster in the second step. Quantitative 1H NMR data, fit to a detailed kinetic model, demonstrates that this effect (which is conceptually closely related to minor enantiomer recycling and related processes) can significantly improve the intrinsic selectivity of the reactions. Our results serve as proof of principle for how multiple selective reaction steps can work together to enhance the stereoselectivity of synthetic processes forming complex mechanically interlocked molecules.

2.
Article in English | MEDLINE | ID: mdl-38377303

ABSTRACT

ABSTRACT: Healthcare avoidance of the LGBTQIA+ community is growing, in part, due to a knowledge gap in medical learners on LGBTQIA+-related topics. Barriers of including LGBTQIA+ topics in medical education include perceived lack of applicability and preceptor knowledge gaps. Advocating for a weave-like integration approach, topics such as personal biases, hormone replacement therapy, STI prevention, and health inequities should be included. It is imperative that PA educators use this call to action to avoid perpetuating the cultural incompetence of new graduate PAs.

3.
bioRxiv ; 2023 Sep 28.
Article in English | MEDLINE | ID: mdl-37808639

ABSTRACT

More than half of all women will experience a urinary tract infection (UTI) in their lifetime with most cases caused by uropathogenic Escherichia coli (UPEC). Bacterial motility enhances UPEC pathogenicity, resulting in more severe disease outcomes including kidney infection. Surprisingly, the connection between motility and iron limitation is mostly unexplored, despite the lack of free iron available in the host. Therefore, we sought to explore the potential connection between iron restriction and regulation of motility in UPEC. We cultured E. coli CFT073, a prototypical UPEC strain, in media containing an iron chelator. Under iron limitation, CFT073 had elevated fliC (flagella) promoter activity, driving motility on the leading edge of the colony. Furthermore, this iron-specific response was repressed by the addition of exogenous iron. We confirmed increased flagella expression in CFT073 by measuring fliC transcript, FliC protein, and surface-expressed flagella under iron-limited conditions. To define the regulatory mechanism, we constructed single knockouts of eight master regulators. The iron-regulated response was lost in crp, arcA, and fis mutants. Thus, we focused on the five genes regulated by all three transcription factors. Of the five genes knocked out, the iron-regulated motility response was most strongly dysregulated in an lpdA mutant, which also resulted in significantly lowered fitness in the murine model of ascending UTI. Collectively, we demonstrated that iron-mediated motility in CFT073 is regulated by lpdA , which contributes to the understanding of how uropathogens differentially regulate motility mechanisms in the iron-restricted host. Importance: Urinary tract infections (UTIs) are ubiquitous and responsible for over five billion dollars in associated health care costs annually. Both iron acquisition and motility are highly studied virulence factors associated with uropathogenic E. coli (UPEC), the main causative agent of uncomplicated UTI. This work is innovative by providing mechanistic insight into the synergistic relationship between these two critical virulence properties. Here, we demonstrate that iron limitation has pleiotropic effects with consequences that extend beyond metabolism, and impact other virulence mechanisms. Indeed, targeting iron acquisition as a therapy may lead to an undesirable enhancement of UPEC pathogenesis through increased motility. It is vital to understand the full breadth of UPEC pathogenesis to adequately respond to this common infection, especially with the increase of antibiotic resistant pathogens.

5.
BMC Plant Biol ; 23(1): 210, 2023 Apr 22.
Article in English | MEDLINE | ID: mdl-37085749

ABSTRACT

BACKGROUND: The floral volatile profile of Petunia x hybrida 'Mitchell diploid' (MD) is dominated by phenylpropanoids, many of which are derived from p-coumaric acid. However, the downstream processes involved in the production of caffeoyl-CoA and feruloyl-CoA from p-coumaric acid are complex, as the genes and biosynthesis steps are associated with flavonoids and lignin synthesis as well as floral volatiles benzenoid/phenylpropanoid (FVBP). Caffeoyl shikimate esterase (CSE) converts caffeoyl shikimate to caffeic acid and is considered one of the essential regulators in lignin production. Moreover, CSE in involved in phenylpropanoid production. To investigate the roles of CSE in FVBP biosynthesis, we used RNAi-mediated CSE down-regulated (ir-PhCSE) petunias. RESULTS: Lowered CSE transcript accumulation in ir-PhCSE plants resulted in reduced lignin layers in the stems and stunted growth, suggesting a positive correlation between lignin layers and lignin content. The altered CSE level influenced the expression of many FVBP genes, including elevated transcripts of p-coumarate-3-hydroxylase (C3H), hydroxycinnamoyl transferase (HCT), and 4-coumaric acid: CoA ligase (4CL). In particular, the expression of C4H in ir-PhCSE plants was more than twice the expression in MD plants. Moreover, the production of volatile compounds was alterend in ir-PhCSE plants. Most floral volatiles decreased, and the amounts of phenylalanine and caffeic acid were significantly lower. CONCLUSIONS: Reduced lignin layers in the stems and stunted growth in ir-PhCSE plants suggest that PhCSE is essential for lignin production and plant growth in petunia. The decreased CSE level influenced the expression of many FVBP genes, and interference of shikimate derivates altered volatile compound production. Significantly decreased caffeic acid, but not ferulic acid, in ir-PhCSE plants suggest that CSE is primarily involved in the reaction of caffeoyl shikimate. Higher C3H and C4H transcripts seem to alleviate accumulated p-coumaric acid resulting from altered CSE. Finally, alteration in C3H, HCT, and 4CL in CSE down-regulated plants suggests an interaction of the FVBP genes, leading to the regulation of floral volatiles of petunia.


Subject(s)
Esterases , Petunia , Esterases/genetics , Lignin/metabolism , Petunia/genetics , Petunia/metabolism , Down-Regulation , Plant Proteins/genetics , Plant Proteins/metabolism , Mixed Function Oxygenases/genetics , Gene Expression Regulation, Plant
6.
ASAIO J ; 69(2): 137-144, 2023 02 01.
Article in English | MEDLINE | ID: mdl-36355803

ABSTRACT

Extracorporeal membrane oxygenation (ECMO) poses unique thrombotic and hemorrhagic risks, and the optimal anticoagulant choice is unknown. We systematically searched Ovid EBM Reviews, Ovid Embase, Ovid Medline, Scopus, and Web of Science Core Collection for randomized-, crossover-, retrospective cohort-, or parallel-designed clinical studies of adult patients receiving ECMO that compared heparin recipients with bivalirudin recipients. Meta-analysis was performed with random-effects models. The ROBINS-I tool was used to assess the risk of bias. Six retrospective observational studies met the inclusion criteria for the qualitative summary. Five studies were suitable for meta-analysis. Those who received heparin were more likely to experience circuit-related thrombosis (odds ratio [OR] 2.05, 95% confidence interval [CI] 1.25-3.37, p = 0.005, I2 = 0%) and die (OR 1.62, 95% CI 1.19-2.21, p = 0.002, I2 = 0%) compared with those who received bivalirudin. There were no differences in major bleeding events between heparin and bivalirudin recipients (OR 1.83, 95% CI 0.55-6.09, p = 0.33, I2 = 82.7%). In retrospective settings compared with heparin anticoagulation, bivalirudin was associated with less circuit-related thrombotic events and greater survival in adults supported on ECMO, without contributing to more bleeding complications. Prospective controlled studies comparing heparin and bivalirudin in adult ECMO patients are warranted to corroborate these findings.


Subject(s)
Anticoagulants , Extracorporeal Membrane Oxygenation , Heparin , Peptide Fragments , Thrombosis , Adult , Humans , Anticoagulants/adverse effects , Anticoagulants/therapeutic use , Extracorporeal Membrane Oxygenation/adverse effects , Heparin/adverse effects , Heparin/therapeutic use , Hirudins/adverse effects , Hirudins/pharmacology , Peptide Fragments/adverse effects , Peptide Fragments/therapeutic use , Prospective Studies , Recombinant Proteins/adverse effects , Recombinant Proteins/therapeutic use , Retrospective Studies , Thrombosis/etiology , Thrombosis/prevention & control , Hirudin Therapy
7.
Ann Thorac Surg ; 115(4): 966-973, 2023 04.
Article in English | MEDLINE | ID: mdl-35973484

ABSTRACT

BACKGROUND: There is no consensus regarding postoperative anticoagulation after mitral valve repair (MVRep). We compared the outcomes of post-MVRep anticoagulation with apixaban compared to warfarin. METHODS: We reviewed data of 666 patients who underwent isolated robotic MVRep between January 2008 and October 2019. We excluded patients who had conversion to sternotomy and those discharged without anticoagulation or on clopidogrel (n = 40). Baseline and intraoperative characteristics and antiplatelet/anticoagulation records were collected. In-hospital and post-discharge complications and overall survival were compared. RESULTS: Among the 626 studied patients the median age was 58 years (interquartile range, 51-66), 71% were male, and 1% (n = 9) had atrial fibrillation. Eighty percent (n = 499) were discharged on warfarin and 20% on apixaban (n = 127). Almost all patients (126 of 127, 99%) in the apixaban group were also on aspirin at discharge, whereas in the warfarin group only 79% (n = 395) were also on aspirin at discharge. Baseline characteristics were similar, except that the apixaban group had more female patients (46 of 127, 36% vs 136 of 499, 27%, P = .047). There were no differences in in-hospital complications, including stroke. Readmission rate was higher in the apixaban group (15 of 127, 12% vs 30 of 499, 6%, P = .02), driven mostly by postoperative atrial fibrillation (6 of 127 [5%] vs 5 of 499 [1%], respectively; P = .01). There was no difference in other complications (including bleeding and thromboembolic events), or overall mortality within 3 years. Exclusion of patients who did not receive aspirin at discharge did not affect the results. CONCLUSIONS: Anticoagulation with apixaban after minimally invasive robotic MVRep is safe and has similar rates of bleeding and thromboembolism compared to patients treated with warfarin.


Subject(s)
Atrial Fibrillation , Robotic Surgical Procedures , Stroke , Thromboembolism , Male , Humans , Female , Middle Aged , Warfarin/therapeutic use , Atrial Fibrillation/complications , Anticoagulants/therapeutic use , Mitral Valve/surgery , Aftercare , Robotic Surgical Procedures/adverse effects , Patient Discharge , Stroke/etiology , Pyridones/therapeutic use , Hemorrhage/chemically induced , Thromboembolism/etiology , Thromboembolism/prevention & control , Aspirin/therapeutic use , Treatment Outcome
8.
Inj Epidemiol ; 9(Suppl 1): 34, 2022 Dec 21.
Article in English | MEDLINE | ID: mdl-36544193

ABSTRACT

BACKGROUND: The COVID-19 pandemic resulted in drastic decreases in volume for most pediatric emergency departments (ED). Injuries have persisted and there is concern that injuries may have increased during the pandemic. This study evaluates the impact of the COVID-19 pandemic on ED patient trends at a freestanding children's hospital. RESULTS: Despite an average annual increase of 1100 patients per year between 2017 and 2019, this ED saw a decrease of over 25,000 patients in 2020. The number of trauma alerts increased from 341 in 2017 to 571 in 2020 and those numbers remained stable (568-571) in 2020 compared to 2019. The percent of total volume accounted for by trauma alerts increased from 0.65 to 1.2% between 2019 and 2020 (following the trend of 0.48% in 2017 to 0.56% in 2018). Historically, motor vehicle crashes account for the majority of the trauma alerts, though the number of trauma alerts from firearm-related injuries increased from 36 per year in 2018 to 44 in 2019 to 66 (12% of total trauma alerts) in 2020. CONCLUSIONS: While total volumes of patients being seen decreased, the number of trauma alerts remained stable resulting in an increased percentage of trauma alert patients. This indicates that severe injuries requiring trauma alert activation did not diminish during the pandemic. These trends have implications for prevention as well as implications for ED staffing. Changing trends in types of severe injuries are noted.

9.
mSystems ; 7(6): e0082722, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36445110

ABSTRACT

For women in the United States, urinary tract infections (UTIs) are the most frequent diagnosis in emergency departments, comprising 21.3% of total visits. Uropathogenic Escherichia coli (UPEC) causes ~80% of uncomplicated UTIs. To combat this public health issue, it is vital to characterize UPEC strains as well as to differentiate them from commensal strains to reduce the overuse of antibiotics. It has been challenging to determine a consistent genetic signature that clearly distinguishes UPEC from other E. coli strains. Therefore, we examined whether phenotypic data could be predictive of uropathogenic potential. We screened 13 clinical strains of UPEC, isolated from cases of uncomplicated UTI in young otherwise healthy women, in a series of microbiological phenotypic assays using UPEC prototype strain CFT073 and nonpathogenic E. coli strain MG1655 K-12 as controls. Phenotypes included adherence, iron acquisition, biofilm formation, human serum resistance, motility, and stress resistance. By use of a well-established experimental mouse model of UTI, these data were able to predict the severity of the bacterial burden in both the urine and bladders. Multiple linear regression using three different phenotypic assays, i.e., growth in minimal medium, siderophore production, and type 1 fimbrial expression, was predictive of bladder colonization (adjusted R2 = 0.6411). Growth in ex vivo human urine, hemagglutination of red blood cells, and motility modeled urine colonization (adjusted R2 = 0.4821). These results showcase the utility of phenotypic characterization to predict the severity of infection that these strains may cause. We predict that these methods will also be applicable to other complex, genetically redundant, pathogens. IMPORTANCE Urinary tract infections are the second leading infectious disease worldwide, occurring in over half of the female population during their lifetime. Most infections are caused by uropathogenic Escherichia coli (UPEC) strains. These strains can establish a reservoir in the gut, in which they do not cause disease but, upon introduction to the urinary tract, can infect the host and elicit pathogenesis. Clinically, it would be beneficial to screen patient E. coli strains to understand their pathogenic potential, which may lead to the administration of prophylactic antibiotic treatment for those with increased risk. Others have proposed the use of PCR-based genetic screening methods to detect UPEC strains and differentiate them from other E. coli pathotypes; however, this method has not yielded a consistent uropathogenic genetic signature. Here, we used phenotypic characteristics such as growth rate, siderophore production, and expression of fimbriae to better predict uropathogenic potential.


Subject(s)
Escherichia coli Infections , Escherichia coli Proteins , Urinary Tract Infections , Female , Humans , Animals , Mice , Escherichia coli/genetics , Escherichia coli Infections/diagnosis , Siderophores , Virulence Factors/genetics , Escherichia coli Proteins/genetics , Urinary Tract Infections/diagnosis , Anti-Bacterial Agents , Phenotype
10.
Clin Radiol ; 77(10): e711-e718, 2022 10.
Article in English | MEDLINE | ID: mdl-35948490

ABSTRACT

AIM: To assess if radiomic feature analysis could help to differentiate between the lipid-poor adenomas and metastases to the adrenal glands. MATERIALS AND METHODS: Eighty-six patients (women:men 42:44; mean age 66 years) with biopsy-proven adrenal metastases and 55 patients (women:men 39:16; mean age 67 years) with lipid-poor adenomas who underwent contrast-enhanced, portal-venous phase CT of the abdomen. Radiomic features were extracted using the PyRadiomics extension for 3D Slicer. Following elastic net regularisation, seven of 1,132 extracted radiomic features were selected to build a radiomic signature. This was combined with patient demographics to create a predictive nomogram. The calibration curves in both the training and validation cohorts were assessed using a Hosmer-Lemeshow test. RESULTS: The radiomic signature alone yielded an area under the curve of 91.7% in the training cohort (n=93) and 87.1% in the validation cohort (n=48). The predictive nomogram, which combined age, a previous history of malignancy, and the radiomic signature, had an AUC of 97.2% in the training cohort and 90.4% in the validation cohort. CONCLUSION: The present nomogram has the potential to differentiate between a lipid-poor adrenal adenoma and adrenal metastasis on portal-venous CT.


Subject(s)
Adenoma , Adrenal Gland Neoplasms , Abdomen/pathology , Adenoma/diagnostic imaging , Adenoma/pathology , Adrenal Gland Neoplasms/diagnostic imaging , Adrenal Gland Neoplasms/secondary , Aged , Female , Humans , Lipids , Male , Retrospective Studies , Tomography, X-Ray Computed
11.
Clin Radiol ; 77(7): 514-521, 2022 07.
Article in English | MEDLINE | ID: mdl-35487779

ABSTRACT

AIM: To evaluate the change in diagnosis rates, disease severity at presentation, and treatment of acute appendicitis and diverticulitis during the COVID-19 shutdown. MATERIALS AND METHODS: Following institutional review board approval, 6,002 CT examinations performed at five hospitals for suspected acute appendicitis and/or diverticulitis over the 12 weeks preceding and following the shutdown were reviewed retrospectively. Semi-automated language analysis (SALA) of the report classified 3,676 CT examinations as negative. Images of the remaining 2,326 CT examinations were reviewed manually and classified as positive or negative. Positive cases were graded as non-perforated; perforated, contained; and perforated, free. RESULTS: CT examinations performed for suspected appendicitis and/or diverticulitis decreased from 3,558 to 2,200 following the shutdown. The rates of positive diagnoses before and after shutdown were 4% (144) and 4% (100) for appendicitis and 8% (284) and 7% (159) for diverticulitis (p>0.2 for both). For positive CT examinations, the rates of perforation, hospitalisation, surgery, and catheter drainage changed by -2%, -3%, -2%, and -3% for appendicitis (n=244, p>0.3 for all) and +6% (p=0.2) +9% (p=0.06), +4% (p=0.01) and +1% (p=0.6) for diverticulitis (n=443). CONCLUSION: CT examinations performed for suspected appendicitis or diverticulitis declined after the shutdown, likely reflecting patients leaving urban centres and altered triage of non-COVID-19 patients. The diagnosis rates, disease severity at presentation, and treatment approach otherwise remained mostly unchanged.


Subject(s)
Appendicitis , COVID-19 , Diverticulitis , Acute Disease , Appendicitis/diagnostic imaging , Appendicitis/surgery , COVID-19/diagnostic imaging , Diverticulitis/diagnostic imaging , Diverticulitis/surgery , Humans , Retrospective Studies , Tomography, X-Ray Computed/methods
12.
SEMERGEN, Soc. Esp. Med. Rural Gen. (Ed. Impr.) ; 48(3): 214-218, Abr. 2022. tab
Article in Spanish | IBECS | ID: ibc-205227

ABSTRACT

La terapia inhalada con broncodilatadores de acción larga es la base del tratamiento farmacológico de la EPOC. Con el fin conocer los que ofrecen un mejor control, se realizó una búsqueda en Medline (Pubmed). Se analizaron los estudios comparativos de terapia inhaladora en pacientes con EPOC. Tras la comparación entre la combinación fija LABA/LAMA frente LABA/CI en pacientes no exacerbadores, se concluye que hay un mejor control con LABA/LAMA. Dentro de las combinaciones LABA/CI, la combinación budesonida/formoterol ofreció un mejor control. En la terapia LAMA no hay grandes diferencias, pero comparada con LABA ofreció un mayor control. La triple terapia en un único dispositivo se muestra superior a la doble terapia y a la triple terapia en dos dispositivos, no habiendo diferencias relevantes entre las combinaciones disponibles (AU)


Inhaled therapy with long-acting bronchodilators is the base of pharmacological treatment in COPD. In order to find out those that offer better control, a search was carried out in Medline (Pubmed). Comparative studies of inhaler therapy in COPD patients were analyzed. The comparison between the fixed combination LABA/LAMA versus LABA/CI in non-exacerbating patients, revealed a better control with LABA/LAMA. Within the LABA/CI combinations, budesonide/formoterol combination offered better control. LAMA inhalers revealed no great differences, but when compared to LABA, it offered a better control. Regarding triple therapy in a single device, was superior to double therapy and to triple therapy in two devices, with no relevant differences among the available combinations(AU)


Subject(s)
Humans , Administration, Inhalation , Pulmonary Disease, Chronic Obstructive/drug therapy , Adrenal Cortex Hormones/administration & dosage , Adrenergic beta-2 Receptor Agonists/administration & dosage , Bronchodilator Agents/administration & dosage , Muscarinic Antagonists/administration & dosage , Drug Therapy, Combination
13.
Semergen ; 48(3): 214-218, 2022 Apr.
Article in Spanish | MEDLINE | ID: mdl-34493458

ABSTRACT

Inhaled therapy with long-acting bronchodilators is the base of pharmacological treatment in COPD. In order to find out those that offer better control, a search was carried out in Medline (Pubmed). Comparative studies of inhaler therapy in COPD patients were analyzed. The comparison between the fixed combination LABA/LAMA versus LABA/CI in non-exacerbating patients, revealed a better control with LABA/LAMA. Within the LABA/CI combinations, budesonide/formoterol combination offered better control. LAMA inhalers revealed no great differences, but when compared to LABA, it offered a better control. Regarding triple therapy in a single device, was superior to double therapy and to triple therapy in two devices, with no relevant differences among the available combinations.


Subject(s)
Adrenergic beta-2 Receptor Agonists , Pulmonary Disease, Chronic Obstructive , Administration, Inhalation , Adrenal Cortex Hormones , Bronchodilator Agents , Drug Combinations , Drug Therapy, Combination , Humans , Muscarinic Antagonists/therapeutic use , Pulmonary Disease, Chronic Obstructive/drug therapy
14.
Climacteric ; 25(2): 203-207, 2022 04.
Article in English | MEDLINE | ID: mdl-33949252

ABSTRACT

A growing body of literature has suggested that the perimenopause and the early postmenopausal years are associated with an increased risk of experiencing symptoms of depression and the development of first-onset and recurrent episodes of major depressive disorder. Multiple risk factors have been identified, including stressful life events and lower socioeconomic status, as well as early life adversity. The objective of the current study was to characterize the influence of early life childhood maltreatment and incident depression among women experiencing bothersome menopausal symptoms. Participants were recruited from two university-affiliated specialty clinics caring for women with bothersome menopausal symptoms. Assessments included the Childhood Trauma Questionnaire (CTQ), the Center for Epidemiological Studies - Depression (CES-D) scale and the Greene Climacteric Scale. Findings from this cross-sectional study indicate that adverse childhood experiences, as measured using the CTQ, were highly prevalent among women seeking care for bothersome menopausal symptoms (66%). Further, a greater score on the CTQ was significantly associated with higher CES-D scores, as well as with a greater burden of menopausal symptoms, after adjusting for confounding. Our findings lend support to the growing body of literature suggesting that early life stress affects mental health well into adulthood.


Subject(s)
Child Abuse , Depressive Disorder, Major , Adult , Child , Child Abuse/psychology , Cross-Sectional Studies , Depression/epidemiology , Female , Humans , Male , Menopause/psychology , Surveys and Questionnaires
15.
J Biol Chem ; 297(6): 101362, 2021 12.
Article in English | MEDLINE | ID: mdl-34756886

ABSTRACT

The Nsp9 replicase is a conserved coronaviral protein that acts as an essential accessory component of the multi-subunit viral replication/transcription complex. Nsp9 is the predominant substrate for the essential nucleotidylation activity of Nsp12. Compounds specifically interfering with this viral activity would facilitate its study. Using a native mass-spectrometry-based approach to screen a natural product library for Nsp9 binders, we identified an ent-kaurane natural product, oridonin, capable of binding to purified SARS-CoV-2 Nsp9 with micromolar affinities. By determining the crystal structure of the Nsp9-oridonin complex, we showed that oridonin binds through a conserved site near Nsp9's C-terminal GxxxG-helix. In enzymatic assays, oridonin's binding to Nsp9 reduces its potential to act as substrate for Nsp12's Nidovirus RdRp-Associated Nucleotidyl transferase (NiRAN) domain. We also showed using in vitro cellular assays oridonin, while cytotoxic at higher doses has broad antiviral activity, reducing viral titer following infection with either SARS-CoV-2 or, to a lesser extent, MERS-CoV. Accordingly, these preliminary findings suggest that the oridonin molecular scaffold may have the potential to be developed into an antiviral compound to inhibit the function of Nsp9 during coronaviral replication.


Subject(s)
Antiviral Agents/pharmacology , COVID-19 Drug Treatment , Diterpenes, Kaurane/pharmacology , RNA-Binding Proteins/metabolism , SARS-CoV-2/drug effects , Viral Nonstructural Proteins/metabolism , Virus Replication/drug effects , Animals , Antiviral Agents/chemistry , Binding Sites/drug effects , Biological Products/chemistry , Biological Products/pharmacology , COVID-19/metabolism , COVID-19/virology , Chlorocebus aethiops , Diterpenes, Kaurane/chemistry , Humans , Molecular Docking Simulation , RNA-Binding Proteins/chemistry , SARS-CoV-2/chemistry , SARS-CoV-2/physiology , Vero Cells , Viral Nonstructural Proteins/chemistry
16.
J Biol Chem ; 297(5): 101283, 2021 11.
Article in English | MEDLINE | ID: mdl-34626646

ABSTRACT

Ubiquinone (Coenzyme Q) is a vital respiratory cofactor and liposoluble antioxidant. In plants, it is not known how the C-6 hydroxylation of demethoxyubiquinone, the penultimate step in ubiquinone biosynthesis, is catalyzed. The combination of cross-species gene network modeling along with mining of embryo-defective mutant databases of Arabidopsis thaliana identified the embryo lethal locus EMB2421 (At1g24340) as a top candidate for the missing plant demethoxyubiquinone hydroxylase. In marked contrast with prototypical eukaryotic demethoxyubiquinone hydroxylases, the catalytic mechanism of which depends on a carboxylate-bridged di-iron domain, At1g24340 is homologous to FAD-dependent oxidoreductases that instead use NAD(P)H as an electron donor. Complementation assays in Saccharomyces cerevisiae and Escherichia coli demonstrated that At1g24340 encodes a functional demethoxyubiquinone hydroxylase and that the enzyme displays strict specificity for the C-6 position of the benzoquinone ring. Laser-scanning confocal microscopy also showed that GFP-tagged At1g24340 is targeted to mitochondria. Silencing of At1g24340 resulted in 40 to 74% decrease in ubiquinone content and de novo ubiquinone biosynthesis. Consistent with the role of At1g24340 as a benzenoid ring modification enzyme, this metabolic blockage could not be bypassed by supplementation with 4-hydroxybenzoate, the immediate precursor of ubiquinone's ring. Unlike in yeast, in Arabidopsis overexpression of demethoxyubiquinone hydroxylase did not boost ubiquinone content. Phylogenetic reconstructions indicated that plant demethoxyubiquinone hydroxylase is most closely related to prokaryotic monooxygenases that act on halogenated aromatics and likely descends from an event of horizontal gene transfer between a green alga and a bacterium.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Mitochondria , Mixed Function Oxygenases , Phylogeny , Ubiquinone , Arabidopsis/enzymology , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Mitochondria/enzymology , Mitochondria/genetics , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Ubiquinone/genetics , Ubiquinone/metabolism
17.
Clin Radiol ; 76(12): 879-888, 2021 12.
Article in English | MEDLINE | ID: mdl-34243943

ABSTRACT

The role of imaging in clinically staging colorectal cancer has grown substantially in the 21st century with more widespread availability of multi-row detector computed tomography (CT), high-resolution magnetic resonance imaging (MRI) with diffusion weighted imaging (DWI), and integrated positron-emission tomography (PET)/CT. In contrast to staging many other cancers, increasing colorectal cancer stage does not highly correlate with survival. As has been the case previously, clinical practice incorporates advances in staging and it is used to guide therapy before adoption into international staging guidelines. Emerging imaging techniques show promise to become part of future staging standards.


Subject(s)
Colorectal Neoplasms/diagnostic imaging , Colorectal Neoplasms/pathology , Neoplasm Staging , Humans , Magnetic Resonance Imaging , Multimodal Imaging , Positron-Emission Tomography , Tomography, X-Ray Computed , Whole Body Imaging
18.
J Biol Chem ; 297(3): 101018, 2021 09.
Article in English | MEDLINE | ID: mdl-34331944

ABSTRACT

The coronaviral nonstructural protein 9 (Nsp9) is essential for viral replication; it is the primary substrate of Nsp12's pseudokinase domain within the viral replication transcription complex, an association that also recruits other components during different stages of RNA reproduction. In the unmodified state, Nsp9 forms an obligate homodimer via an essential GxxxG protein-interaction motif, but its ssRNA-binding mechanism remains unknown. Using structural biological techniques, here we show that a base-mimicking compound identified from a small molecule fragment screen engages Nsp9 via a tetrameric Pi-Pi stacking interaction that induces the formation of a parallel trimer-of-dimers. This oligomerization mechanism allows an interchange of "latching" N-termini, the charges of which contribute to a series of electropositive channels that suggests a potential interface for viral RNA. The identified pyrrolo-pyrimidine compound may also serve as a potential starting point for the development of compounds seeking to probe Nsp9's role within SARS-CoV-2 replication.


Subject(s)
COVID-19/virology , Pyrimidine Nucleotides/metabolism , RNA-Binding Proteins/metabolism , SARS-CoV-2/metabolism , Viral Proteins/metabolism , Nuclear Magnetic Resonance, Biomolecular/methods , Protein Binding , RNA/metabolism , SARS-CoV-2/physiology , Virus Replication
20.
Cell Host Microbe ; 29(7): 1052-1062, 2021 07 14.
Article in English | MEDLINE | ID: mdl-34022154

ABSTRACT

COVID-19 can result in severe disease characterized by significant immunopathology that is spurred by an exuberant, yet dysregulated, innate immune response with a poor adaptive response. A limited and delayed interferon I (IFN-I) and IFN-III response results in exacerbated proinflammatory cytokine production and in extensive cellular infiltrates in the respiratory tract, resulting in lung pathology. The development of effective therapeutics for patients with severe COVID-19 depends on our understanding of the pathological elements of this unbalanced innate immune response. Here, we review the mechanisms by which SARS-CoV-2 both activates and antagonizes the IFN and inflammatory response following infection, how a dysregulated cytokine and cellular response contributes to immune-mediated pathology in COVID-19, and therapeutic strategies that target elements of the innate response.


Subject(s)
COVID-19/immunology , Immunity, Innate/immunology , Interferons/therapeutic use , SARS-CoV-2/immunology , Animals , Anti-Inflammatory Agents/therapeutic use , Cytokines/metabolism , Disease Models, Animal , Humans , Immune Evasion , Interferon Type I/metabolism , Interferons/metabolism , Kinetics , Interferon Lambda , COVID-19 Drug Treatment
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