Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 42
Filter
1.
Life Sci Alliance ; 7(3)2024 03.
Article in English | MEDLINE | ID: mdl-38195117

ABSTRACT

Juvenile neuronal ceroid lipofuscinosis (or Batten disease) is an autosomal recessive, rare neurodegenerative disorder that affects mainly children above the age of 5 yr and is most commonly caused by mutations in the highly conserved CLN3 gene. Here, we generated cln3 morphants and stable mutant lines in zebrafish. Although neither morphant nor mutant cln3 larvae showed any obvious developmental or morphological defects, behavioral phenotyping of the mutant larvae revealed hyposensitivity to abrupt light changes and hypersensitivity to pro-convulsive drugs. Importantly, in-depth metabolomics and lipidomics analyses revealed significant accumulation of several glycerophosphodiesters (GPDs) and cholesteryl esters, and a global decrease in bis(monoacylglycero)phosphate species, two of which (GPDs and bis(monoacylglycero)phosphates) were previously proposed as potential biomarkers for CLN3 disease based on independent studies in other organisms. We could also demonstrate GPD accumulation in human-induced pluripotent stem cell-derived cerebral organoids carrying a pathogenic variant for CLN3 Our models revealed that GPDs accumulate at very early stages of life in the absence of functional CLN3 and highlight glycerophosphoinositol and BMP as promising biomarker candidates for pre-symptomatic CLN3 disease.


Subject(s)
Induced Pluripotent Stem Cells , Neuronal Ceroid-Lipofuscinoses , Animals , Humans , Cholesterol Esters , Membrane Glycoproteins/genetics , Metabolomics , Molecular Chaperones , Neuronal Ceroid-Lipofuscinoses/genetics , Zebrafish/genetics
2.
J Patient Exp ; 10: 23743735231174759, 2023.
Article in English | MEDLINE | ID: mdl-37323758

ABSTRACT

The patient's financial experience is often complex and confusing.Recent regulations support bringing more transparency to healthcare billing processes.A patient journey map illustrates the patient experience in a healthcare process helping to identify improvement opportunities to better support patient-centered care.Price transparency can be increased by communicating the patient's financial responsibility early in the care process as well as simplifying patient communications.Digital health applications can help improve the patient financial experience and ultimately engagement in the payment process.Greater clarity and improved processes may occur if the patient's journey is visualized.

3.
J Inherit Metab Dis ; 44(6): 1323-1329, 2021 11.
Article in English | MEDLINE | ID: mdl-34176136

ABSTRACT

3-Hydroxyisobutyric acid (3HiB) is an intermediate in the degradation of the branched-chain amino acid valine. Disorders in valine degradation can lead to 3HiB accumulation and its excretion in the urine. This article describes the first two patients with a new metabolic disorder, 3-hydroxyisobutyrate dehydrogenase (HIBADH) deficiency, its phenotype and its treatment with a low-valine diet. The detected mutation in the HIBADH gene leads to nonsense-mediated mRNA decay of the mutant allele and to a complete loss-of-function of the enzyme. Under strict adherence to a low-valine diet a rapid decrease of 3HiB excretion in the urine was observed. Due to limited patient numbers and intrafamilial differences in phenotype with one affected and one unaffected individual, the clinical phenotype of HIBADH deficiency needs further evaluation.


Subject(s)
Alcohol Oxidoreductases/deficiency , Amino Acid Metabolism, Inborn Errors/diet therapy , Amino Acid Metabolism, Inborn Errors/diagnosis , Hydroxybutyrates/urine , Alcohol Oxidoreductases/metabolism , Child, Preschool , Diagnosis, Differential , Female , Humans , Hydroxybutyrates/chemistry , Hydroxybutyrates/metabolism , Infant , Male , Valine/metabolism
4.
Mar Pollut Bull ; 162: 111807, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33162055

ABSTRACT

Petroleum waxes (PWs) are recognized as ubiquitously emerging marine pollutants. However, knowledge on their occurrence, particularly as persistent floaters of small size (<5 mm) in marine surface water, is scarce. For this study, 24 samples were collected in the North Sea by net-sampling (100 µm-mesh). Particles of wax-like appearance were detected at 14 stations. Similar appearing PWs from six stations with highest abundances were pooled per station and analyzed by ATR-FTIR (Attenuated total reflectance Fourier-transform infrared spectroscopy) and gas chromatography. Samples contained paraffin particles, being partly accompanied by substances like fatty acids and fatty alcohols. Using both analytical techniques provided a reliable detection of PWs and more details on their chemical composition. Furthermore, exemplarily the presence of PWs of 20-500 µm size was proven by µFTIR imaging. This study gives valuable insights into PW pollution in the North Sea, emphasizing the need for harmonized detection methods, ideally accompanying microplastics monitoring.


Subject(s)
Petroleum , Water Pollutants, Chemical , Environmental Monitoring , North Sea , Paraffin , Plastics , Spectroscopy, Fourier Transform Infrared , Water Pollutants, Chemical/analysis , Waxes
5.
J Therm Spray Technol ; 30(1-2): 222-235, 2021.
Article in English | MEDLINE | ID: mdl-38624721

ABSTRACT

Besides conventional industrial demands, thermally sprayed coatings are increasingly used for innovative products. Such an application is the additive manufacturing of electrical components in automotive engineering. In particular, heating units are currently manufactured by a combination of various spray technologies. At present, simpler spraying processes like flame spraying are investigated with regard to their suitability as a future cost-effective alternative for fabricating isolating alumina coatings. In the present study, alumina cords were flame-sprayed using compressed air and argon as atomizing gases. The results demonstrate finely dispersed microstructures and a more regular and partially even higher surface and volume resistivity compared to past investigations in the literature as well as conventionally plasma-sprayed coatings despite a significantly reduced coating thickness. The content of alpha phase is clearly higher than for plasma-sprayed coatings, regardless of the atomizing gas used. Moreover, flame-sprayed coatings using argon reveal a higher resistivity in comparison to coatings sprayed with air. While the atomizing gas is found to mainly influence the ideal stand-off distance, the phase composition is not changed severely. In addition to the phase composition and kinematics, it can finally be concluded that humidity plays a major role in the coating properties.

6.
J Patient Exp ; 7(5): 657-664, 2020 Oct.
Article in English | MEDLINE | ID: mdl-33294595

ABSTRACT

The COVID-19 pandemic has led to rapid change in health care, accelerating the use of digital health services, including telehealth. Moreover, growth in value-based care has compelled consumers to become more engaged in care processes. It has also provided opportunities to enhance patient experiences by increasing patients' access to online health information and services. This study assessed online patient engagement practices for 6 common patient touchpoints by reviewing the websites of the top 32 hospitals, including the top 10 children's hospitals. The great majority of these hospitals provided some information related to these patient touchpoints. However, the scope and extent of task automation varied significantly and many options were not convenient. Based on this study, it is clear that patient experience can be enhanced by improving online patient engagement, particularly during the current global pandemic.

7.
J Appl Lab Med ; 5(3): 467-479, 2020 05 01.
Article in English | MEDLINE | ID: mdl-32445360

ABSTRACT

BACKGROUND: Deafness and hearing loss are common conditions that can be seen independently or as part of a syndrome and are often mediated by genetic causes. We sought to develop and validate a hereditary hearing loss panel (HHLP) to detect single nucleotide variants (SNVs), insertions and deletions (indels), and copy number variants (CNVs) in 166 genes related to nonsyndromic and syndromic hearing loss. METHODS: We developed a custom-capture next-generation sequencing (NGS) reagent to detect all coding regions, ±10 flanking bp, for the 166 genes related to nonsyndromic and syndromic hearing loss. Our validation consisted of testing 52 samples to establish accuracy, reproducibility, and analytical sensitivity. In addition to NGS, supplementary methods, including multiplex ligation-dependent probe amplification, long-range PCR, and Sanger sequencing, were used to ensure coverage of regions that had high complexity or homology. RESULTS: We observed 100% positive and negative percentage agreement for detection of SNVs (n = 362), small indels (1-22 bp, n = 25), and CNVs (gains, n = 8; losses, n = 17). Finally, we showed that this assay was able to detect variants with a variant allele frequency ≥20% for SNVs and indels and ≥30% to 35% for CNVs. CONCLUSIONS: We validated an HHLP that detects SNVs, indels, and CNVs in 166 genes related to syndromic and nonsyndromic hearing loss. The results of this assay can be utilized to confirm a diagnosis of hearing loss and related syndromic disorders associated with known causal genes.


Subject(s)
Genetic Predisposition to Disease , Genetic Testing , Hearing Loss/diagnosis , Hearing Loss/genetics , High-Throughput Nucleotide Sequencing , Alleles , Amino Acid Substitution , Chromosome Mapping , Computational Biology/methods , Genetic Association Studies , Genetic Testing/methods , Genotype , High-Throughput Nucleotide Sequencing/methods , High-Throughput Nucleotide Sequencing/standards , Humans , Molecular Diagnostic Techniques , Reproducibility of Results
8.
J Patient Exp ; 7(6): 1535-1542, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33457611

ABSTRACT

The need to provide patient-centered care has been recognized by major players in the health-care field. As such, attention has been placed on patients' experience of the health care they receive, and health-care organizations have been investing in patient experience initiatives and staffing to implement those initiatives. Given this, the objective for this study was to investigate the qualifications and skills US health-care organizations seek for patient experience positions through a content analysis of job postings. Results show that patient experience positions are largely found in health systems and hospitals. These positions include coordinators, directors, managers, specialists, and advisors. Five key skills were identified: collaborating with stakeholders; coordinating, planning, and executing service excellence programs; handling complaints and grievances; educating and training leadership and frontline employees; and providing excellent customer service. The skills vary depending on the position. The overall goal for patient experience positions is to ensure a complete and positive patient experience. As these patient experience positions are relatively new, requirements will likely evolve over time as organizations adapt patient experience strategies.

9.
J Cancer Educ ; 35(5): 897-904, 2020 10.
Article in English | MEDLINE | ID: mdl-31073869

ABSTRACT

Best practices to facilitate high-quality shared decision-making for lung cancer screening (LCS) are not well established. In our LCS program, patients are first referred to attend a free group education class on LCS, taught by designated clinician specialists, before a personal shared decision-making visit is scheduled. We conducted an evaluation on  the effectiveness of this class to enhance patient knowledge and shared decision-making about LCS. For quality improvement purposes, participants were asked to complete one-page surveys immediately before and after class to assess knowledge and decision-making capacity regarding LCS. To evaluate knowledge gained, we tabulated the distributions of correct, incorrect, unsure, and missing responses to eight true-false statements included on both pre- and post-class surveys and assessed pre-post differences in the number of correct responses. To evaluate decision-making capacity, we tabulated the distributions of post-class responses to items on decision uncertainty. From June 2017 to August 2018, 680 participants completed both pre- and post-class surveys. Participants had generally poor baseline knowledge about LCS. The proportion who responded correctly to each knowledge-related statement increased pre- to post-class, with a mean difference of 0.9 (paired t test, p < 0.0001) in the total number of correct responses between surveys. About 70% reported having all the information needed to make a screening decision. Our results suggest that a well-designed group education class is an effective system-level approach for initially educating and equipping patients with appropriate knowledge to make informed decisions about LCS.


Subject(s)
Decision Making , Early Detection of Cancer/psychology , Health Knowledge, Attitudes, Practice , Lung Neoplasms/diagnosis , Patient Education as Topic/methods , Aged , Aged, 80 and over , Educational Status , Female , Humans , Lung Neoplasms/psychology , Male , Middle Aged , Quality Improvement , Surveys and Questionnaires
10.
RNA ; 25(11): 1522-1531, 2019 11.
Article in English | MEDLINE | ID: mdl-31427457

ABSTRACT

If the A-form helix is the major structural motif found in RNA, the loops that cap them constitute the second most important family of motifs. Among those, two are overrepresented, GNRA and UNCG tetraloops. Recent surveys of RNA structures deposited in the PDB show that GNRA and UNCG tetraloops can adopt tertiary folds that are very different from their canonical conformations, characterized by the presence of a U-turn of a Z-turn, respectively. Crystallographic data from both a lariat-capping (LC) ribozyme and a group II intron ribozyme reveal that a given UUCG tetraloop can adopt a distinct fold depending on its structural environment. Specifically, when the crystal packing applies relaxed constraints on the loop, the canonical Z-turn conformation is observed. In contrast, a highly packed environment induces "squashing" of the tetraloop by distorting its sugar-phosphate backbone in a specific way that expels the first and fourth nucleobases out of the loop, and falls in van der Waals distance of the last base pair of the helix, taking the place of the pair formed between the first and fourth residues in Z-turn loops. The biological relevance of our observations is supported by the presence of similarly deformed loops in the highly packed environment of the ribosome and in a complex between a dsRNA and a RNase III. The finding that Z-turn loops change conformation under higher molecular packing suggests that, in addition to their demonstrated role in stabilizing RNA folding, they may contribute to the three-dimensional structure of RNA by mediating tertiary interactions with distal residues.


Subject(s)
Nucleic Acid Conformation , RNA/chemistry , Crystallography, X-Ray , Introns , RNA, Catalytic/chemistry
11.
Environ Pollut ; 252(Pt B): 1719-1729, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31284214

ABSTRACT

Microplastic pollution within the marine environment is of pressing concern globally. Accordingly, spatial monitoring of microplastic concentrations, composition and size distribution may help to identify sources and entry pathways, and hence allow initiating focused mitigation. Spatial distribution patterns of microplastics were investigated in two compartments of the southern North Sea by collecting sublittoral sediment and surface water samples from 24 stations. Large microplastics (500-5000 µm) were detected visually and identified using attenuated total reflection (ATR) Fourier transform infrared (FTIR) spectroscopy. The remaining sample was digested enzymatically, concentrated onto filters and analyzed for small microplastics (11-500 µm) using Focal Plane Array (FPA) FTIR imaging. Microplastics were detected in all samples with concentrations ranging between 2.8 and 1188.8 particles kg-1 for sediments and 0.1-245.4 particles m-3 for surface waters. On average 98% of microplastics were <100 µm in sediments and 86% in surface waters. The most prevalent polymer types in both compartments were polypropylene, acrylates/polyurethane/varnish, and polyamide. However, polymer composition differed significantly between sediment and surface water samples as well as between the Frisian Islands and the English Channel sites. These results show that microplastics are not evenly distributed, in neither location nor size, which is illuminating regarding the development of monitoring protocols.


Subject(s)
Environmental Monitoring/methods , Geologic Sediments/chemistry , Plastics/analysis , Water Pollutants, Chemical/analysis , North Sea , Polypropylenes/analysis , Polyurethanes/analysis , Seawater/chemistry , Spatial Analysis
12.
J Patient Exp ; 6(2): 103-107, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31218254

ABSTRACT

Patient-centered care is essential for achieving high-quality and cost-effective health care. This is particularly important for patients with chronic or complex conditions who utilize more health-care services and require comprehensive care coordination. This case report draws on a longitudinal journey map-a valuable tool to capture patient experience and inform the care process-for a patient with multiple chronic conditions who needed a hip replacement. An analysis of the patient journey revealed 3 critical needs for a more patient-centered process: (1) making the patient health goal visible; (2) instigating transparent, shared decision-making; and (3) using a closed-loop communication process. Although key challenges exist, systems can facilitate more patient-centered care enabling health-care organizations to improve the patient experience across the continuum and provide higher quality care.

13.
Int J Health Care Qual Assur ; 32(1): 281-295, 2019 Feb 11.
Article in English | MEDLINE | ID: mdl-30859866

ABSTRACT

PURPOSE: The purpose of this paper is to examine the competencies that US healthcare organizations require for quality and performance improvement positions. DESIGN/METHODOLOGY/APPROACH: A US healthcare improvement job posting content analysis was conducted using the HQ Essentials competency framework. FINDINGS: The HQ essentials competencies most desired for improvement positions include project management, training, data analysis and applied performance improvement methods. Competency requirements varied somewhat by job focus area: performance, quality, or process improvement, and Lean and Six Sigma. PRACTICAL IMPLICATIONS: Healthcare leaders may use the author's results to understand what competencies may be required for various improvement roles and to identify any gaps in required skills and knowledge areas that may need to be addressed. Educators and policy-makers should consider how these competencies align with employers' needs and what resources or professional development may be needed to address gaps. ORIGINALITY/VALUE: This is the first healthcare improvement competencies analysis based on job postings.


Subject(s)
Delivery of Health Care/organization & administration , Personnel Selection/organization & administration , Quality Improvement , Surveys and Questionnaires , Work Performance , Female , Humans , Job Application , Leadership , Male , Qualitative Research , Total Quality Management , United States
14.
J Am Med Inform Assoc ; 26(5): 383-391, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30830169

ABSTRACT

OBJECTIVE: Growth in big data and its potential impact on the healthcare industry have driven the need for more data scientists. In health care, big data can be used to improve care quality, increase efficiency, lower costs, and drive innovation. Given the importance of data scientists to U.S. healthcare organizations, I examine the qualifications and skills these organizations require for data scientist positions and the specific focus of their work. MATERIALS AND METHODS: A content analysis of U.S. healthcare data scientist job postings was conducted using an inductive approach to capture and categorize core information about each posting and a deductive approach to evaluate skills required. Profiles were generated for 4 job focus areas. RESULTS: There is a spectrum of healthcare data scientist positions that varies based on hiring organization type, job level, and job focus area. The focus of these positions ranged from performance improvement to innovation and product development with some positions more broadly defined to address organizational-specific needs. Based on the job posting sample, the primary skills these organizations required were statistics, R, machine learning, storytelling, and Python. CONCLUSIONS: These results may be useful to organizations as they deepen our understanding of the qualifications and skills required for data scientist positions and may aid organizations in identifying skills and knowledge areas that have been overlooked in position postings.


Subject(s)
Data Science , Health Workforce/statistics & numerical data , Job Description , Data Science/statistics & numerical data , Health Workforce/standards , Personnel Selection , United States
15.
Nucleic Acids Res ; 47(6): 3223-3232, 2019 04 08.
Article in English | MEDLINE | ID: mdl-30759226

ABSTRACT

Natural products that target the eukaryotic ribosome are promising therapeutics to treat a variety of cancers. It is therefore essential to determine their molecular mechanism of action to fully understand their mode of interaction with the target and to inform the development of new synthetic compounds with improved potency and reduced cytotoxicity. Toward this goal, we have previously established a short synthesis pathway that grants access to multiple congeners of the lissoclimide family. Here we present the X-ray co-crystal structure at 3.1 Å resolution of C45, a potent congener with two A-ring chlorine-bearing stereogenic centers with 'unnatural' configurations, with the yeast 80S ribosome, intermolecular interaction energies of the C45/ribosome complex, and single-molecule FRET data quantifying the impact of C45 on both human and yeast ribosomes. Together, these data provide new insights into the role of unusual non-covalent halogen bonding interactions involved in the binding of this synthetic compound to the 80S ribosome.


Subject(s)
Biological Products/chemistry , Diterpenes/chemistry , Models, Molecular , Ribosomes/chemistry , Succinimides/chemistry , Cryoelectron Microscopy , Crystallography, X-Ray , Diterpenes/chemical synthesis , Eukaryotic Cells/chemistry , Humans , Protein Binding , RNA, Ribosomal/chemistry , RNA, Ribosomal/genetics , Ribosomes/genetics , Saccharomyces cerevisiae/chemistry , Succinimides/chemical synthesis
16.
J Healthc Manag ; 63(6): 427-444, 2018.
Article in English | MEDLINE | ID: mdl-30418372

ABSTRACT

EXECUTIVE SUMMARY: Healthcare reform and the implementation of a national quality strategy in the United States have increased emphasis on quality improvement. Additionally, as healthcare organizations focus on value, they are paying more attention to quality in the context of cost and seeking to address these concerns through various performance improvement initiatives. Given the importance of these initiatives, this study analyzed the improvement job positions posted by U.S. healthcare organizations, specifically with respect to the qualifications and skills required. The author conducted a content analysis of improvement job postings using an inductive approach to capture and categorize core information about each posting and a deductive approach to evaluate skills required for selected job areas. The results show that healthcare organizations have invested in a breadth of improvement positions across all levels of the organization. Many positions are tied to strategic initiatives. The greatest number of positions posted were in the performance improvement area, followed by quality improvement, process improvement, Lean, Six Sigma, and Lean Six Sigma. These research results may be useful to healthcare organizations for strategic resource planning purposes and to educators and professional associations to target programs that offer students and members the opportunity to gain needed qualifications and skills.


Subject(s)
Employment , Professional Competence/standards , Quality Improvement , Quality of Health Care , Health Facilities , Quality of Health Care/standards , United States
17.
Structure ; 26(3): 416-425.e4, 2018 03 06.
Article in English | MEDLINE | ID: mdl-29429877

ABSTRACT

Alkaloids isolated from the Amaryllidaceae plants have potential as therapeutics for treating human diseases. Haemanthamine has been studied as a novel anticancer agent due to its ability to overcome cancer cell resistance to apoptosis. Biochemical experiments have suggested that hemanthamine targets the ribosome. However, a structural characterization of its mechanism has been missing. Here we present the 3.1 Å resolution X-ray structure of haemanthamine bound to the Saccharomyces cerevisiae 80S ribosome. This structure reveals that haemanthamine targets the A-site cleft on the large ribosomal subunit rearranging rRNA to halt the elongation phase of translation. Furthermore, we provide evidence that haemanthamine and other Amaryllidaceae alkaloids also inhibit specifically ribosome biogenesis, triggering nucleolar stress response and leading to p53 stabilization in cancer cells. Together with a computer-aided interpretation of existing structure-activity relationships of Amaryllidaceae alkaloids congeners, we provide a rationale for designing molecules with enhanced potencies and reduced toxicities.


Subject(s)
Amaryllidaceae Alkaloids/pharmacology , Antineoplastic Agents/pharmacology , Colonic Neoplasms/metabolism , Phenanthridines/pharmacology , Ribosomes/metabolism , Saccharomyces cerevisiae/metabolism , Amaryllidaceae Alkaloids/chemistry , Antineoplastic Agents/chemistry , Binding Sites , Cell Proliferation/drug effects , Colonic Neoplasms/drug therapy , Crystallography, X-Ray , HCT116 Cells , Humans , Models, Molecular , Molecular Conformation , Phenanthridines/chemistry , RNA, Ribosomal/chemistry , RNA, Ribosomal/metabolism , Ribosomes/chemistry , Saccharomyces cerevisiae Proteins/metabolism , Structure-Activity Relationship , Tumor Suppressor Protein p53/metabolism
18.
Proc Natl Acad Sci U S A ; 114(49): 12934-12939, 2017 12 05.
Article in English | MEDLINE | ID: mdl-29158377

ABSTRACT

Ribosomal RNAs (rRNAs) are main effectors of messenger RNA (mRNA) decoding, peptide-bond formation, and ribosome dynamics during translation. Ribose 2'-O-methylation (2'-O-Me) is the most abundant rRNA chemical modification, and displays a complex pattern in rRNA. 2'-O-Me was shown to be essential for accurate and efficient protein synthesis in eukaryotic cells. However, whether rRNA 2'-O-Me is an adjustable feature of the human ribosome and a means of regulating ribosome function remains to be determined. Here we challenged rRNA 2'-O-Me globally by inhibiting the rRNA methyl-transferase fibrillarin in human cells. Using RiboMethSeq, a nonbiased quantitative mapping of 2'-O-Me, we identified a repertoire of 2'-O-Me sites subjected to variation and demonstrate that functional domains of ribosomes are targets of 2'-O-Me plasticity. Using the cricket paralysis virus internal ribosome entry site element, coupled to in vitro translation, we show that the intrinsic capability of ribosomes to translate mRNAs is modulated through a 2'-O-Me pattern and not by nonribosomal actors of the translational machinery. Our data establish rRNA 2'-O-Me plasticity as a mechanism providing functional specificity to human ribosomes.


Subject(s)
Protein Biosynthesis , RNA, Ribosomal/metabolism , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , Gene Expression Regulation , Gene Knockdown Techniques , HeLa Cells , Humans , Methylation
19.
Nat Chem ; 9(11): 1140-1149, 2017 11.
Article in English | MEDLINE | ID: mdl-29064494

ABSTRACT

The lissoclimides are unusual succinimide-containing labdane diterpenoids that were reported to be potent cytotoxins. Our short semisynthesis and analogue-oriented synthesis approaches provide a series of lissoclimide natural products and analogues that expand the structure-activity relationships (SARs) in this family. The semisynthesis approach yielded significant quantities of chlorolissoclimide (CL) to permit an evaluation against the National Cancer Institute's 60-cell line panel and allowed us to obtain an X-ray co-crystal structure of the synthetic secondary metabolite with the eukaryotic 80S ribosome. Although it shares a binding site with other imide-based natural product translation inhibitors, CL engages in a particularly interesting and novel face-on halogen-π interaction between the ligand's alkyl chloride and a guanine residue. Our analogue-oriented synthesis provides many more lissoclimide compounds, which were tested against aggressive human cancer cell lines and for protein synthesis inhibitory activity. Finally, computational modelling was used to explain the SARs of certain key compounds and set the stage for the structure-guided design of better translation inhibitors.


Subject(s)
Diterpenes/chemical synthesis , Diterpenes/pharmacology , Protein Biosynthesis/drug effects , Succinimides/chemical synthesis , Succinimides/pharmacology , Animals , Antineoplastic Agents, Phytogenic/chemical synthesis , Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Biological Products/chemical synthesis , Biological Products/chemistry , Biological Products/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Crystallography, X-Ray , Diterpenes/chemistry , Drug Screening Assays, Antitumor , Eukaryotic Initiation Factors/antagonists & inhibitors , Eukaryotic Initiation Factors/metabolism , Humans , Mice , Models, Molecular , Molecular Conformation , Peptides, Cyclic , Succinimides/chemistry
20.
Cell Chem Biol ; 24(5): 605-613.e5, 2017 May 18.
Article in English | MEDLINE | ID: mdl-28457705

ABSTRACT

Protein synthesis plays an essential role in cell proliferation, differentiation, and survival. Inhibitors of eukaryotic translation have entered the clinic, establishing the translation machinery as a promising target for chemotherapy. A recently discovered, structurally unique marine sponge-derived brominated alkaloid, (-)-agelastatin A (AglA), possesses potent antitumor activity. Its underlying mechanism of action, however, has remained unknown. Using a systematic top-down approach, we show that AglA selectively inhibits protein synthesis. Using a high-throughput chemical footprinting method, we mapped the AglA-binding site to the ribosomal A site. A 3.5 Å crystal structure of the 80S eukaryotic ribosome from S. cerevisiae in complex with AglA was obtained, revealing multiple conformational changes of the nucleotide bases in the ribosome accompanying the binding of AglA. Together, these results have unraveled the mechanism of inhibition of eukaryotic translation by AglA at atomic level, paving the way for future structural modifications to develop AglA analogs into novel anticancer agents.


Subject(s)
Alkaloids/pharmacology , Antineoplastic Agents/pharmacology , Biological Products/pharmacology , Oxazolidinones/pharmacology , Protein Biosynthesis/drug effects , Alkaloids/metabolism , Antineoplastic Agents/metabolism , Biological Products/metabolism , Dose-Response Relationship, Drug , HeLa Cells , Humans , Molecular Docking Simulation , Oxazolidinones/metabolism , Protein Conformation , Ribosomes/drug effects , Ribosomes/genetics
SELECTION OF CITATIONS
SEARCH DETAIL
...