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1.
Crit Rev Toxicol ; : 1-14, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38832580

ABSTRACT

Despite the growing epidemiological evidence of an association between toxin exposure and developmental neurotoxicity (DNT), systematic testing of DNT is not mandatory in international regulations for admission of pharmaceuticals or industrial chemicals. However, to date around 200 compounds, ranging from pesticides, pharmaceuticals and industrial chemicals, have been tested for DNT in the current OECD test guidelines (TG-443 or TG-426). There are calls for the development of new approach methodologies (NAMs) for DNT, which has resulted in a DNT testing battery using in vitro human cell-based assays. These assays provide a means to elucidate the molecular mechanisms of toxicity in humans which is lacking in animal-based toxicity tests. However, cell-based assays do not represent all steps of the complex process leading to DNT. Validated models with a multi-organ network of pathways that interact at the molecular, cellular and tissue level at very specific timepoints in a life cycle are currently missing. Consequently, whole model organisms are being developed to screen for, and causally link, new molecular targets of DNT compounds and how they affect whole brain development and neurobehavioral endpoints. Given the practical and ethical restraints associated with vertebrate testing, lower animal models that qualify as 3 R (reduce, refine and replace) models, including the nematode (Caenorhabditis elegans) and the zebrafish (Danio rerio) will prove particularly valuable for unravelling toxicity pathways leading to DNT. Although not as complex as the human brain, these 3 R-models develop a complete functioning brain with numerous neurodevelopmental processes overlapping with human brain development. Importantly, the main signalling pathways relating to (neuro)development, metabolism and growth are highly conserved in these models. We propose the use of whole model organisms specifically zebrafish and C. elegans for DNT relevant endpoints.

2.
Neurotoxicology ; 102: 48-57, 2024 May.
Article in English | MEDLINE | ID: mdl-38552718

ABSTRACT

Developmental neurotoxicity (DNT) is not routinely evaluated in chemical risk assessment because current test paradigms for DNT require the use of mammalian models which are ethically controversial, expensive, and resource demanding. Consequently, efforts have focused on revolutionizing DNT testing through affordable novel alternative methods for risk assessment. The goal is to develop a DNT in vitro test battery amenable to high-throughput screening (HTS). Currently, the DNT in vitro test battery consists primarily of human cell-based assays because of their immediate relevance to human health. However, such cell-based assays alone are unable to capture the complexity of a developing nervous system. Whole organismal systems that qualify as 3 R (Replace, Reduce and Refine) models are urgently needed to complement cell-based DNT testing. These models can provide the necessary organismal context and be used to explore the impact of chemicals on brain function by linking molecular and/or cellular changes to behavioural readouts. The nematode Caenorhabditis elegans, the planarian Dugesia japonica, and embryos of the zebrafish Danio rerio are all suited to low-cost HTS and each has unique strengths for DNT testing. Here, we review the strengths and the complementarity of these organisms in a novel, integrative context and highlight how they can augment current cell-based assays for more comprehensive and robust DNT screening of chemicals. Considering the limitations of all in vitro test systems, we discuss how a smart combinatory use of these systems will contribute to a better human relevant risk assessment of chemicals that considers the complexity of the developing brain.


Subject(s)
Brain , Caenorhabditis elegans , Neurotoxicity Syndromes , Toxicity Tests , Animals , Neurotoxicity Syndromes/etiology , Brain/drug effects , Brain/growth & development , Toxicity Tests/methods , Caenorhabditis elegans/drug effects , Humans , Zebrafish , Planarians/drug effects , Behavior, Animal/drug effects , Animal Testing Alternatives/methods , Risk Assessment , High-Throughput Screening Assays
3.
Matrix Biol ; 128: 1-10, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38378098

ABSTRACT

The extracellular matrix (ECM) is a network of macromolecules that presents a vital scaffold for cells and enables multiple ways of cellular communication. Thus, it is essential for many physiological processes such as development, tissue morphogenesis, homeostasis, the shape and partially the size of the body and its organs. To ensure these, the composition of the ECM is tissue-specific and highly dynamic. ECM homeostasis is therefore tightly controlled by several mechanisms. Here, we show that FMI-1, the homolog of the Adhesion GPCR Flamingo/CELSR/ADGRC in the nematode Caenorhabditis elegans, modulates the composition of the ECM by controlling the production both of ECM molecules such as collagens and also of ECM modifying enzymes. Thereby, FMI-1 affects the morphology and functionality of the nematode´s cuticle, which is mainly composed of ECM, and also modulates the body size. Mechanistic analyses highlight the fact that FMI-1 exerts its function from neurons non-cell autonomously (trans) solely via its extracellular N terminus. Our data support a model, by which the activity of the receptor, which has a well-described role in the planar cell polarity (PCP) pathway, involves the PCP molecule VANG-1, but seems to be independent of the DBL-1/BMP pathway.


Subject(s)
Cadherins , Caenorhabditis elegans Proteins , Animals , Body Size , Cadherins/metabolism , Caenorhabditis elegans/genetics , Caenorhabditis elegans/physiology , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/metabolism , Cell Communication , Extracellular Matrix/metabolism
4.
J Med Chem ; 67(2): 1500-1512, 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38227216

ABSTRACT

Casitas B-lymphoma proto-oncogene-b (Cbl-b), a member of the Cbl family of RING finger E3 ubiquitin ligases, has been demonstrated to play a central role in regulating effector T-cell function. Multiple studies using gene-targeting approaches have provided direct evidence that Cbl-b negatively regulates T, B, and NK cell activation via a ubiquitin-mediated protein modulation. Thus, inhibition of Cbl-b ligase activity can lead to immune activation and has therapeutic potential in immuno-oncology. Herein, we describe the discovery and optimization of an arylpyridone series as Cbl-b inhibitors by structure-based drug discovery to afford compound 31. This compound binds to Cbl-b with an IC50 value of 30 nM and induces IL-2 production in T-cells with an EC50 value of 230 nM. Compound 31 also shows robust intracellular target engagement demonstrated through inhibition of Cbl-b autoubiquitination, inhibition of ubiquitin transfer to ZAP70, and the cellular modulation of phosphorylation of a downstream signal within the TCR axis.


Subject(s)
Proto-Oncogene Proteins c-cbl , Ubiquitin-Protein Ligases , Proto-Oncogene Proteins c-cbl/metabolism , Ubiquitin-Protein Ligases/metabolism , T-Lymphocytes/metabolism , Phosphorylation , Ubiquitin/metabolism
5.
NPJ Parkinsons Dis ; 9(1): 169, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38114496

ABSTRACT

Parkinson's disease (PD) is a chronic, progressive and disabling neurodegenerative disorder. The prevalence of PD has risen considerably over the past decades. A growing body of evidence suggest that exposure to environmental toxins, including pesticides, solvents and heavy metals (collectively called toxins), is at least in part responsible for this rapid growth. It is worrying that the current screening procedures being applied internationally to test for possible neurotoxicity of specific compounds offer inadequate insights into the risk of developing PD in humans. Improved screening procedures are therefore urgently needed. Our review first substantiates current evidence on the relation between exposure to environmental toxins and the risk of developing PD. We subsequently propose to replace the current standard toxin screening by a well-controlled multi-tier toxin screening involving the following steps: in silico studies (tier 1) followed by in vitro tests (tier 2), aiming to prioritize agents with human relevant routes of exposure. More in depth studies can be undertaken in tier 3, with whole-organism (in)vertebrate models. Tier 4 has a dedicated focus on cell loss in the substantia nigra and on the presumed mechanisms of neurotoxicity in rodent models, which are required to confirm or refute the possible neurotoxicity of any individual compound. This improved screening procedure should not only evaluate new pesticides that seek access to the market, but also critically assess all pesticides that are being used today, acknowledging that none of these has ever been proven to be safe from a perspective of PD. Importantly, the improved screening procedures should not just assess the neurotoxic risk of isolated compounds, but should also specifically look at the cumulative risk conveyed by exposure to commonly used combinations of pesticides (cocktails). The worldwide implementation of such an improved screening procedure, would be an essential step for policy makers and governments to recognize PD-related environmental risk factors.

6.
Health Promot Pract ; : 15248399231172760, 2023 May 11.
Article in English | MEDLINE | ID: mdl-37165856

ABSTRACT

Novel community-wide approaches that gamify physical activity through challenges and competition have become increasingly popular in recent years. However, little is known about the factors that help or hinder their implementation. This qualitative study aimed to address this gap in the literature by systematically investigating the facilitators (organizational and experiential) and barriers to successful implementation of a community-wide intervention delivered in Gloucester, the United Kingdom. A two-phased process evaluation was conducted. Phase 1 involved the thematical analysis of open question feedback from n = 289 adults. Phase 2 included three focus groups conducted with n = 12 participants. This research showed that promoting the initiative through primary education settings was fundamental to enhancing awareness and participation. Social elements of the intervention were identified as a motivating factor for, and a consequential outcome of, participation. A lack of promotion to wider-reaching proportions of the community was perceived to be a significant barrier to implementation, potentially limiting inclusivity and participation in the activity. Game dynamics, timing, and fears regarding sustainability represented further difficulties to implementation.

7.
MicroPubl Biol ; 20232023.
Article in English | MEDLINE | ID: mdl-36855740

ABSTRACT

Women are raising concerns about breast implant illness (BII), a collective term for a range of symptoms attributed to gel bleed. To study this, Caenorhabditis elegans was exposed to increasing duration of gel bleed from silicone breast implants (SBI) and the impact on health parameters observed. SBI exposure results in a slight reduction in total brood size with the progeny having impaired mobility. Nematodes displayed stress characteristics and silicones were detected inside the animals, suggesting silicone uptake after exposure to SBI. Our data highlights the need for more investigations into the mechanisms and pathways impacted by SBI.

8.
Dis Aquat Organ ; 153: 45-49, 2023 Feb 16.
Article in English | MEDLINE | ID: mdl-36794840

ABSTRACT

Managed care of cephalopods can be complicated by numerous factors including infectious and non-infectious disease, environmental stressors, and anatomic and physiological changes associated with senescence. The current report describes a unique case of nephrolithiasis in a senescent, >2 yr old female Pacific octopus Enteroctopus dofleini housed in a public aquarium. Clinical signs included generalized external pallor, inappetence progressing to anorexia, lethargy, and a slow healing mantle abrasion over a period of a year. Due to the animal's declining condition, humane euthanasia was elected. At necropsy, multiple, small, approximately 1-5 mm diameter crystalline deposits were reported throughout all sections of the renal appendages. Histopathology identified a large crystal expanding and rupturing a focal tubule, causing necrosis, ulceration, and hemocytic infiltration. Crystalline stone analysis revealed that the nephrolith was composed of 100% ammonium acid urate. Additional changes to the digestive gland included marked atrophy with fibrosis correlated to the animal's history of hyporexia/anorexia secondary to senescence. To our knowledge, this is the first report of nephrolithiasis in E. dofleini.


Subject(s)
Kidney Calculi , Octopodiformes , Animals , Female , Anorexia/veterinary , Kidney Calculi/veterinary , Kidney
9.
J Med Chem ; 66(4): 2918-2945, 2023 02 23.
Article in English | MEDLINE | ID: mdl-36727211

ABSTRACT

Herein, we report the optimization of a meta-substituted series of selective estrogen receptor degrader (SERD) antagonists for the treatment of ER+ breast cancer. Structure-based design together with the use of modeling and NMR to favor the bioactive conformation led to a highly potent series of basic SERDs with promising physicochemical properties. Issues with hERG activity resulted in a strategy of zwitterion formation and ultimately in the identification of 38. This compound was shown to be a highly potent SERD capable of effectively degrading ERα in both MCF-7 and CAMA-1 cell lines. The low lipophilicity and zwitterionic nature led to a SERD with a clean secondary pharmacology profile and no hERG activity. Favorable physicochemical properties resulted in good oral bioavailability in preclinical species and potent in vivo activity in a mouse xenograft model.


Subject(s)
Breast Neoplasms , Receptors, Estrogen , Mice , Humans , Animals , Female , Receptors, Estrogen/metabolism , Selective Estrogen Receptor Modulators/pharmacology , Estrogen Antagonists/therapeutic use , Breast Neoplasms/drug therapy , Estrogen Receptor alpha/metabolism , Cell Line
10.
Br J Soc Psychol ; 62(1): 241-263, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36097335

ABSTRACT

The phrase 'in it together' has been used liberally since the outbreak of COVID-19, but the extent that frontline workers felt 'in it together' is not well understood. Here, we consider the factors that built (or eroded) solidarity while working through the pandemic, and how frontline workers navigated their lives through periods of disconnection. Semi-structured interviews with 21 frontline workers, across all sectors, were conducted in the United Kingdom and Ireland. The qualitative data were analysed systematically using reflexive thematic analysis. The three themes identified in the data were: (1) Solidarity as central to frontline experiences; (2) Leadership as absent, shallow and divisive: highlighting 'us-them' distinctions and (3) The rise of 'us' and 'we' among colleagues. Our research offers insights into how frontline workers make sense of their experiences of solidarity and discordance during the first year of the COVID-19 pandemic, with relevance for government and organizational policy-makers shaping future conditions for frontline workers.


Subject(s)
COVID-19 , Humans , Ireland , Pandemics , United Kingdom , Emotions , Health Personnel
11.
Heliyon ; 8(8): e10108, 2022 Aug.
Article in English | MEDLINE | ID: mdl-36033279

ABSTRACT

Obesity is one of the most common global health problems for all age groups with obese people at risk of a variety of associated health complications. Consequently, there is a need to develop new therapies that lower body fat without the side effects. However, obesity is a complex and systemic disease, so that in vitro results are not easily translatable to clinical situations. A promising way to circumnavigate these issues is to reposition already approved drugs for new treatments, enabling a more streamlined drug discovery process due to the availability of pre-existing pharmacological and toxicological datasets. Chemical libraries, such as the Prestwick Chemical Library of 1200 FDA approved drugs, are available for this purpose. We have developed a simple semi-automated whole-organism approach to screening the Prestwick Chemical Library for those compounds which reduce fat content using the model organism Caenorhabditis elegans. Our whole-organism approach to high-throughput screening identified 9 "lead" compounds that reduced fat within 2 weeks in the model. Further screening and analysis provided 4 "hit" compounds (Midodrine, Vinpocetine, Fenoprofen and Lamivudine) that showed significant promise as drugs to reduce fat levels. The effects of these candidates were found to further reduce fat content in nematodes where an nhr-49/PPAR mutation resulted in "overweight" worms. Upon unblinding the "hit" compounds, they were found to have recently been shown to have anti-obesity effects in mammalian models too. In developing a whole-animal chemical screen to identify pharmacological agents as potential anti-obesity compounds, we demonstrate how chemical libraries can be rapidly and relatively cheaply profiled for active hits. Using the nematode Caenorhabditis elegans thus enables drugs to be assessed for applicability in humans and provides a new incentive to explore drug repurposing as a feasible and efficient way to identify new anti-obesity compounds.

12.
Pharmaceuticals (Basel) ; 15(5)2022 Apr 22.
Article in English | MEDLINE | ID: mdl-35631338

ABSTRACT

Despite Parkinson's Disease (PD) being the second most common neurodegenerative disease, treatment options are limited. Consequently, there is an urgent need to identify and screen new therapeutic compounds that slow or reverse the pathology of PD. Unfortunately, few new therapeutics are being produced, partly due to the low throughput and/or poor predictability of the currently used model organisms and in vivo screening methods. Our objective was to develop a simple and affordable platform for drug screening utilizing the nematode Caenorhabditis elegans. The effect of Levodopa, the "Gold standard" of PD treatment, was explored in nematodes expressing the disease-causing α-synuclein protein. We focused on two key hallmarks of PD: plaque formation and mobility. Exposure to Levodopa ameliorated the mobility defect in C. elegans, similar to people living with PD who take the drug. Further, long-term Levodopa exposure was not detrimental to lifespan. This C. elegans-based method was used to screen a selection of small-molecule drugs for an impact on α-synuclein aggregation and mobility, identifying several promising compounds worthy of further investigation, most notably Ambroxol. The simple methodology means it can be adopted in many labs to pre-screen candidate compounds for a positive impact on disease progression.

13.
Article in English | MEDLINE | ID: mdl-35627831

ABSTRACT

Kratom (Mitragyna speciosa Korth.) is a tree native to Southeast Asia with stimulant and opioid-like effects which has seen increased use in Europe and North America in recent years. Its safety and pharmacological effects remain under investigation, especially in regard to developmental and generational toxicity. In the current study, we investigated commercial kratom preparations using the nematode Caenorhabditis elegans as a translational model for toxicity and pharmacological effects. The pure alkaloids mitragynine and 7-hydroxymitragynine as well as aqueous, ethanolic, and methanolic extracts of three commercial kratom products were evaluated using a battery of developmental, genotoxic, and opioid-related experiments. As determined previously, the mitragynine and 7-hydroxymitragynine content in kratom samples was higher in the alcoholic extracts than the aqueous extracts. Above the human consumption range equivalent of 15-70 µg/mL, kratom dose-dependently reduced brood size and health of parent worms and their progeny. 7-hydroxymitragynine, but not mitragynine, presented with toxic and developmental effects at very high concentrations, while the positive control, morphine, displayed toxic effects at 0.5 mM. Kratom and its alkaloids did not affect pumping rate or interpump interval in the same way as morphine, suggesting that kratom is unlikely to act primarily via the opioid-signalling pathway. Only at very high doses did kratom cause developmental and genotoxic effects in nematodes, indicating its relative safety.


Subject(s)
Mitragyna , Analgesics, Opioid , Animals , Caenorhabditis elegans , Humans , Morphine Derivatives , Plant Leaves
14.
PLoS One ; 17(2): e0263414, 2022.
Article in English | MEDLINE | ID: mdl-35143546

ABSTRACT

Throughout the world social isolation and loneliness are common and both have several adverse impacts on health and wellbeing. We are designed to live in close-knit communities and we thrive in close co-operation, however, modern life isolates us from others. To reduce the burden of loneliness and social isolation we need to find strategies to reconnect people to each other, their place and provide a common purpose. Social movements aim to create healthier communities by connecting people to each other and giving people a common purpose. Interventions which create a social movement appear to be effective at engaging substantial portions of a community, however, it remains unclear why individuals are attracted to these initiatives, and if such reasons differ by sociodemographic characteristics. This study combined qualitative and quantitative methods to understand what motivated (different) people to take part in a social movement based intervention. This study suggests that it is not one but a combination of reasons people engage in interventions of this nature. This diversity needs to be acknowledged when promoting and communicating these interventions to potential participants to maximise engagement. Promoting an end reward or health/fitness may not be the most effective way to promote interventions to a large proportion of people. Instead, communications should be centred around what people value (i.e., being with their friends, doing what they enjoy and are good at).


Subject(s)
Motivation
15.
J Med Chem ; 65(4): 3306-3331, 2022 02 24.
Article in English | MEDLINE | ID: mdl-35133824

ABSTRACT

ATAD2 is an epigenetic bromodomain-containing target which is overexpressed in many cancers and has been suggested as a potential oncology target. While several small molecule inhibitors have been described in the literature, their cellular activity has proved to be underwhelming. In this work, we describe the identification of a novel series of ATAD2 inhibitors by high throughput screening, confirmation of the bromodomain region as the site of action, and the optimization campaign undertaken to improve the potency, selectivity, and permeability of the initial hit. The result is compound 5 (AZ13824374), a highly potent and selective ATAD2 inhibitor which shows cellular target engagement and antiproliferative activity in a range of breast cancer models.


Subject(s)
ATPases Associated with Diverse Cellular Activities/antagonists & inhibitors , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , DNA-Binding Proteins/antagonists & inhibitors , Cell Line, Tumor , Crystallography, X-Ray , Drug Discovery , Drug Screening Assays, Antitumor , Female , Humans , Models, Molecular , Small Molecule Libraries , Structure-Activity Relationship , Substrate Specificity , Tumor Stem Cell Assay
16.
BMC Nutr ; 8(1): 5, 2022 Jan 13.
Article in English | MEDLINE | ID: mdl-35027085

ABSTRACT

BACKGROUND: Members of the Rosaceae, Solanaceae and Zingiberaceae families which include fruits such as cherries, tomatoes and ginger are known to have health promoting effects. There is growing interest in consuming these "functional foods" as a means to increase health and healthy ageing. However, many studies explore the effect of these foods in isolation, not as a blend of multiple functional foods. METHODS: In this study, an extract containing the dried berries, fruits, and roots of members of these families was prepared, which we called Bioact®180. The nematode Caenorhabditis elegans was used to evaluate the effects of Bioact®180 on lifespan and health endpoints, including muscle and mitochondria structure and locomotion. RESULTS: Exposure to the 1000 µg/mL of Bioact®180 extract, containing 4% total phenols, were healthier, as observed by an increase in mean lifespan with and small but significant increase in maximal lifespan. Nematodes exposed to Bioact®180 displayed better mobility in mid-life stages as well as enhanced mitochondrial morphology, which was more comparable to younger animals, suggesting that these worms are protected to some degree from sarcopenia. CONCLUSIONS: Together, our findings reveal that Bioact®180, a blend of fruits and roots from Rosaceae, Solanaceae and Zingiberaceae family members has anti-aging effects. Bioact®180 promotes health and lifespan extension in C. elegans, corresponding to functional improvements in mobility.

17.
Psychol Health ; 37(2): 151-177, 2022 02.
Article in English | MEDLINE | ID: mdl-34187244

ABSTRACT

OBJECTIVE: Frontline workers have shown extraordinary resilience and sustained efforts since the outbreak of COVID-19. The present study used semi-structured interviews with 38 frontline workers in the UK and Ireland to explore the psychological impact of working through COVID-19. DESIGN: The qualitative data were analysed systematically using thematic analysis. RESULTS: Four themes were interpreted: 1)) "I've stopped turning the telly on. I've had to because the news was making me ill": An ecosystem of influence; 2) "Dead, dead, dead": The emotional and psychological toll: 3) "It's shone a light on what we're failing on as well": Injustices, hierarchies and heroes: and 4) "I definitely think COVID happened for a reason to stop us in our tracks and to slow us down": Unexpected positives. CONCLUSION: This research offers insights into how frontline workers make sense of their experiences during periods of enormous societal and occupational stress. The learnings generated have relevance for government and organisational policy-makers who have opportunities to shape future conditions for frontline workers.


Subject(s)
COVID-19 , Ecosystem , Health Personnel , Humans , Ireland , SARS-CoV-2 , United Kingdom
18.
Appl Biosaf ; 27(4): 231-236, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-37020568

ABSTRACT

Introduction: Healthcare organizations faced unique operational challenges during the COVID-19 pandemic. Assuring the safety of both patients and healthcare workers in hospitals has been the primary focus during the COVID-19 pandemic. Methods: The NIH Vaccine Program (VP) with the Vaccine Management System (VMS) was created based on the commitment of NIH leadership, program leadership, the development team, and the program team; defining Key Performance Indicators (KPIs) of the VP and the VMS; and the NIH Clinical Center's (NIH CC) interdisciplinary approach to deploying the VMS. Results: This article discusses the NIH business requirements of the VP and VMS, the target KPIs of the VP and the VMS, and the NIH CC interdisciplinary approach to deploying an organizational VMS for vaccinating the NIH workforce. The use of the DCRI Spiral-Agile Software Development Life Cycle enabled the development of a system with stakeholder involvement that could quickly adapt to changing requirements meeting the defined KPIs for the program and system. The assessment of the defined KPIs through a survey and comments from the survey support that the VP and VMS were successful. Conclusion: A comprehensive program to maintain a healthy workforce includes asymptomatic COVID testing, symptomatic COVID testing, contact tracing, vaccinations, and policy-driven education. The need to develop systems during the pandemic resulted in changes to build software quickly with the input of many more users and stakeholders then typical in a decreased amount of time.

19.
Elife ; 102021 07 28.
Article in English | MEDLINE | ID: mdl-34319231

ABSTRACT

Mutations within the kinase domain of the epidermal growth factor receptor (EGFR) are common oncogenic driver events in non-small cell lung cancer. Although the activation of EGFR in normal cells is primarily driven by growth-factor-binding-induced dimerization, mutations on different exons of the kinase domain of the receptor have been found to affect the equilibrium between its active and inactive conformations giving rise to growth-factor-independent kinase activation. Using molecular dynamics simulations combined with enhanced sampling techniques, we compare here the conformational landscape of the monomers and homodimers of the wild-type and mutated forms of EGFR ΔELREA and L858R, as well as of two exon 20 insertions, D770-N771insNPG, and A763-Y764insFQEA. The differences in the conformational energy landscapes are consistent with multiple mechanisms of action including the regulation of the hinge motion, the stabilization of the dimeric interface, and local unfolding transitions. Overall, a combination of different effects is caused by the mutations and leads to the observed aberrant signaling.


Subject(s)
Mutation , Carcinoma, Non-Small-Cell Lung/genetics , ErbB Receptors/genetics , ErbB Receptors/metabolism , Humans , Intercellular Signaling Peptides and Proteins/genetics , Lung Neoplasms/genetics , Molecular Dynamics Simulation , Protein Binding
20.
Proc Natl Acad Sci U S A ; 118(9)2021 03 02.
Article in English | MEDLINE | ID: mdl-33627403

ABSTRACT

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder characterized by progressive muscle degeneration and weakness due to mutations in the dystrophin gene. The symptoms of DMD share similarities with those of accelerated aging. Recently, hydrogen sulfide (H2S) supplementation has been suggested to modulate the effects of age-related decline in muscle function, and metabolic H2S deficiencies have been implicated in affecting muscle mass in conditions such as phenylketonuria. We therefore evaluated the use of sodium GYY4137 (NaGYY), a H2S-releasing molecule, as a possible approach for DMD treatment. Using the dys-1(eg33) Caenorhabditis elegans DMD model, we found that NaGYY treatment (100 µM) improved movement, strength, gait, and muscle mitochondrial structure, similar to the gold-standard therapeutic treatment, prednisone (370 µM). The health improvements of either treatment required the action of the kinase JNK-1, the transcription factor SKN-1, and the NAD-dependent deacetylase SIR-2.1. The transcription factor DAF-16 was required for the health benefits of NaGYY treatment, but not prednisone treatment. AP39 (100 pM), a mitochondria-targeted H2S compound, also improved movement and strength in the dys-1(eg33) model, further implying that these improvements are mitochondria-based. Additionally, we found a decline in total sulfide and H2S-producing enzymes in dystrophin/utrophin knockout mice. Overall, our results suggest that H2S deficit may contribute to DMD pathology, and rectifying/overcoming the deficit with H2S delivery compounds has potential as a therapeutic approach to DMD treatment.


Subject(s)
Caenorhabditis elegans Proteins/genetics , Dystrophin/genetics , Hydrogen Sulfide/pharmacology , Mitochondria, Muscle/drug effects , Morpholines/pharmacology , Muscle, Skeletal/drug effects , Muscular Dystrophy, Animal/drug therapy , Organophosphorus Compounds/pharmacology , Organothiophosphorus Compounds/pharmacology , Thiones/pharmacology , Animals , Caenorhabditis elegans/genetics , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Dystrophin/deficiency , Forkhead Transcription Factors/genetics , Forkhead Transcription Factors/metabolism , Gene Expression Regulation , Humans , Hydrogen Sulfide/metabolism , Locomotion/drug effects , Locomotion/genetics , Male , Mice , Mice, Inbred mdx , Mitochondria, Muscle/metabolism , Mitochondria, Muscle/pathology , Mitogen-Activated Protein Kinases/genetics , Mitogen-Activated Protein Kinases/metabolism , Morpholines/metabolism , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Muscular Dystrophy, Animal/genetics , Muscular Dystrophy, Animal/metabolism , Muscular Dystrophy, Animal/pathology , Muscular Dystrophy, Duchenne/drug therapy , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/metabolism , Muscular Dystrophy, Duchenne/pathology , Organophosphorus Compounds/metabolism , Organothiophosphorus Compounds/metabolism , Prednisone/pharmacology , Sirtuins/genetics , Sirtuins/metabolism , Thiones/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Utrophin/deficiency , Utrophin/genetics
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