Beyond chemicals: Opportunities and challenges of integrating non-chemical stressors in adverse outcome pathways.

The adverse outcome pathways (AOPs) were developed to accelerate evidence-based chemical risk assessment by leveraging data from new approach methodologies. Thanks to their stressor-agnostic approach, AOPs were seen as instrumental in other fields. Here, we present AOPs that report non-chemical stressors along with the challenges encountered for their development. Challenges regarding AOPs linked to nanomaterials include non-specific molecular initiating events, limited understanding of nanomaterial biodistribution, and needs for adaptations of the in silico modeling and testing systems. Development of AOPs for radiation face challenges in how to incorporate ionizing events type, dose rate, energy deposition, and how to account for targeting multiple macromolecules. AOPs for COVID-19 required the inclusion of SARS-CoV-2-specific replicative steps to capture the essential events driving the disease. Developing AOPs to evaluate efficacy and toxicity of cell therapies necessitates addressing the cellular nature and the therapeutic function of the stressor. Finally, addressing toxicity of emerging biological stressors like microbial pesticides can learn from COVID-19 AOPs. We further discuss that the adaptations needed to expand AOP applicability beyond chemicals are mainly at the molecular and cellular levels while downstream key events at tissue or organ level, such as inflammation, are shared by many AOPs initiated by various stressors. In conclusion, although it is challenging to integrate non-chemical stressors within AOPs, this expands opportunities to account for real-world scenarios, to identify vulnerable individuals, and to bridge knowledge on mechanisms of adversity.

The adverse outcome pathway (AOP) framework was developed to help predict whether chemicals have toxic effects on humans. Structuring available information in an accessible database can reduce animal testing. AOPs usually capture the path from the interaction of a stressor, usually a chemical, with the human body to an adverse outcome, e.g., a disease symptom. The concept of AOPs has now been expanded to include non-chemical stressors such as nanomaterials, radiation, viruses, cells used to treat patients, and microorganisms employed as pesticides. We use discuss how these stressors need to be accommodated within the framework and point out that pathways initiated by these stressors share downstream events like inflammation with chemical stressors. By integrating non-chemical stressors into the framework, real-world scenarios where people may be exposed to different stressor types can be considered, vulnerable individuals can be identified, and knowledge on toxic effects can be compounded.

A systematic scoping review of the neurological effects of COVID-19.

BACKGROUND: The global coronavirus 2019 (COVID-19) pandemic began in early 2020, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In mid-2020 the CIAO (Modelling the Pathogenesis of COVID-19 Using the Adverse Outcome Pathway Framework) project was established, bringing together over 75 interdisciplinary scientists worldwide to collaboratively investigate the underlying biological mechanisms of COVID-19 and consolidate the data using the Adverse Outcome Pathway (AOP) Framework. Neurological symptoms such as anosmia and encephalitis have been frequently reported to be associated with infection with SARS-CoV-2. OBJECTIVE: Within CIAO, a working group was formed to conduct a systematic scoping review of COVID-19 and its related neurological symptoms to determine which key events and modulating factors are most commonly reported and to identify knowledge gaps. DESIGN: LitCOVID was used to retrieve 86,075 papers of which 10,244 contained relevant keywords. After title and abstract screening, 2,328 remained and their full texts were reviewed based on predefined inclusion and exclusion criteria. 991 studies fulfilled the inclusion criteria and were retrieved to conduct knowledge synthesis. RESULTS: The majority of publications reported human observational studies. Early key events were less likely to be reported compared to middle and late key events/adverse outcomes. The majority of modulating factors described related to age or sex. Less recognised COVID-19 associated AO or neurological effects of COVID-19 were also identified including multiple sclerosis/demyelination, neurodegeneration/cognitive effects and peripheral neuronal effects. CONCLUSION: There were many methodological and reporting issues noted in the reviewed studies. In particular, publication abstracts would benefit from clearer reporting of the methods and endpoints used and the key findings, to ensure relevant papers are included when systematic reviews are conducted. The information extracted from the scoping review may be useful in understanding the mechanisms of neurological effects of COVID-19 and to further develop or support existing AOPs linking COVID-19 and its neurological key events and adverse outcomes. Further evaluation of the less recognised COVID-19 effects is needed.

CIAO: a living experiment in interdisciplinary large-scale collaboration facilitated by the Adverse Outcome Pathway framework.

Introduction: The CIAO project was launched in Spring 2020 to address the need to make sense of the numerous and disparate data available on COVID-19 pathogenesis. Based on a crowdsourcing model of large-scale collaboration, the project has exploited the Adverse Outcome Pathway (AOP) knowledge management framework built to support chemical risk assessment driven by mechanistic understanding of the biological perturbations at the different organizational levels. Hence the AOPs might have real potential to integrate data produced through different approaches and from different disciplines as experienced in the context of COVID-19. In this study, we aim to address the effectiveness of the AOP framework (i) in supporting an interdisciplinary collaboration for a viral disease and (ii) in working as the conceptual mediator of a crowdsourcing model of collaboration. Methods: We used a survey disseminated among the CIAO participants, a workshop open to all interested CIAO contributors, a series of interviews with some participants and a self-reflection on the processes. Results: The project has supported genuine interdisciplinarity with exchange of knowledge. The framework provided a common reference point for discussion and collaboration. The diagram used in the AOPs assisted with making explicit what are the different perspectives brought to the knowledge about the pathways. The AOP-Wiki showed up many aspects about its usability for those not already in the world of AOPs. Meanwhile their use in CIAO highlighted needed adaptations. Introduction of new Wiki elements for modulating factors was potentially the most disruptive one. Regarding how well AOPs support a crowdsourcing model of large-scale collaboration, the CIAO project showed that this is successful when there is a strong central organizational impetus and when clarity about the terms of the collaboration is brought as early as possible. Discussion: Extrapolate the successful CIAO approach and related processes to other areas of science where the AOP could foster interdisciplinary and systematic organization of the knowledge is an exciting perspective.

Reactive Oxygen Species in the Adverse Outcome Pathway Framework: Toward Creation of Harmonized Consensus Key Events.

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are formed as a result of natural cellular processes, intracellular signaling, or as adverse responses associated with diseases or exposure to oxidizing chemical and non-chemical stressors. The action of ROS and RNS, collectively referred to as reactive oxygen and nitrogen species (RONS), has recently become highly relevant in a number of adverse outcome pathways (AOPs) that capture, organize, evaluate and portray causal relationships pertinent to adversity or disease progression. RONS can potentially act as a key event (KE) in the cascade of responses leading to an adverse outcome (AO) within such AOPs, but are also known to modulate responses of events along the AOP continuum without being an AOP event itself. A substantial discussion has therefore been undertaken in a series of workshops named "Mystery or ROS" to elucidate the role of RONS in disease and adverse effects associated with exposure to stressors such as nanoparticles, chemical, and ionizing and non-ionizing radiation. This review introduces the background for RONS production, reflects on the direct and indirect effects of RONS, addresses the diversity of terminology used in different fields of research, and provides guidance for developing a harmonized approach for defining a common event terminology within the AOP developer community.

COVID-19 through Adverse Outcome Pathways: Building networks to better understand the disease - 3rd CIAO AOP Design Workshop.

On April 28-29, 2021, 50 scientists from different fields of expertise met for the 3rd online CIAO workshop. The CIAO project "Modelling the Pathogenesis of COVID-19 using the Adverse Outcome Pathway (AOP) framework" aims at building a holistic assembly of the available scientific knowledge on COVID-19 using the AOP framework. An individual AOP depicts the disease progression from the initial contact with the SARS-CoV-2 virus through biological key events (KE) toward an adverse outcome such as respiratory distress, anosmia or multiorgan failure. Assembling the individual AOPs into a network highlights shared KEs as central biological nodes involved in multiple outcomes observed in COVID-19 patients. During the workshop, the KEs and AOPs established so far by the CIAO members were presented and posi­tioned on a timeline of the disease course. Modulating factors influencing the progression and severity of the disease were also addressed as well as factors beyond purely biological phenomena. CIAO relies on an interdisciplinary crowd­sourcing effort, therefore, approaches to expand the CIAO network by widening the crowd and reaching stakeholders were also discussed. To conclude the workshop, it was decided that the AOPs/KEs will be further consolidated, inte­grating virus variants and long COVID when relevant, while an outreach campaign will be launched to broaden the CIAO scientific crowd.

An evaluation of a community pharmacy-based rural asthma management service.

OBJECTIVE: To compare the effect of a pharmacist-delivered rural asthma management service (RAMS) on health outcomes for people with asthma in a rural/regional area with 'standard care' delivered through community pharmacies. DESIGN: A parallel group controlled repeated measures study. SETTING: Community pharmacies in Central West New South Wales. INTERVENTION: Standardised protocols and resources based on national asthma management guidelines, delivered by specially trained community pharmacists. Patients visited the pharmacy at baseline and 1, 3 and 6 months after baseline in the intervention group and at baseline plus 6 months after baseline in the control group. PARTICIPANTS: The intervention pharmacists (n = 12) were trained to deliver the RAMS model, while control pharmacists (n = 8) provided standard asthma care to their recruited patients. Fifty-one and 39 patients were recruited by intervention and control pharmacists. MAIN OUTCOME MEASURE: Asthma severity score which was a composite score based on recency, frequency and severity of asthma symptoms, and asthma history. RESULTS: Data compared at the final visit between groups indicated that the RAMS patient group demonstrated a significant reduction in the asthma severity scores (7.9 +/- 2.6 versus 10.4 +/- 2.6, P < 0.001); a reduction in the risk of non-adherence to medication scores (1.6 +/- 0.7 versus 2.3 +/- 1.1, P < 0.001); and an increase in the proportion of patients owning a written action plan (50% versus 23%, P = 0.04). CONCLUSIONS: These results indicated that the community pharmacy-based RAMS model can improve asthma outcomes for patients in rural settings, and similar models for asthma and other chronic diseases should be tested rigorously and adopted in rural primary care practice.

Oligomerization of opioid receptors.

Opioid receptors belong to the family of G-protein-coupled receptors characterized by their seven transmembrane domains. The activation of these receptors by agonists such as morphine and endogenous opioid peptides leads to the activation of inhibitory G-proteins followed by a decrease in the levels of intracellular cAMP. Opioid receptor activation is also associated with the opening of K(+) channels and the inhibition of Ca(2+) channels. A number of investigations, prior to the development of opioid receptor cDNAs, suggested that opioid receptor types interacted with each other. Early pharmacological studies provided evidence for the probable interaction between opioid receptors. More recent studies using receptor selective antagonists, antisense oligonucleotides, or animals lacking opioid receptors further suggested that interactions between opioid receptor types could modulate their activity. We examined opioid receptor interactions using biochemical, biophysical, and pharmacological techniques. We used differential epitope tagging and selective immunoisolation of receptor complexes to demonstrate homotypic and heterotypic interactions between opioid receptor types. We also used the proximity-based bioluminescence resonance energy transfer assay to explore opioid receptor-receptor interactions in living cells. In this article we describe the biochemical and biophysical methods involved in the detection of receptor dimers. We also address some of the concerns and suggest precautions to be taken in studies examining receptor-receptor interactions.

A role for heterodimerization of mu and delta opiate receptors in enhancing morphine analgesia.

Opiates such as morphine are the choice analgesic in the treatment of chronic pain. However their long-term use is limited because of the development of tolerance and dependence. Due to its importance in therapy, different strategies have been considered for making opiates such as morphine more effective, while curbing its liability to be abused. One such strategy has been to use a combination of drugs to improve the effectiveness of morphine. In particular, delta opioid receptor ligands have been useful in enhancing morphine's potency. The underlying molecular basis for these observations is not understood. We propose the modulation of receptor function by physical association between mu and delta opioid receptors as a potential mechanism. In support of this hypothesis, we show that mu-delta interacting complexes exist in live cells and native membranes and that the occupancy of delta receptors (by antagonists) is sufficient to enhance mu opioid receptor binding and signaling activity. Furthermore, delta receptor antagonists enhance morphine-mediated intrathecal analgesia. Thus, heterodimeric associations between mu-delta opioid receptors can be used as a model for the development of novel combination therapies for the treatment of chronic pain and other pathologies.