Taking the leap toward human-specific nonanimal methodologies: The need for harmonizing global policies for microphysiological systems.

With a recent amendment, India joined other countries that have removed the legislative barrier toward the use of human-relevant methods in drug development. Here, global stakeholders weigh in on the urgent need to globally harmonize the guidelines toward the standardization of microphysiological systems. We discuss a possible framework for establishing scientific confidence and regulatory approval of these methods.

New horizons of microphysiological systems: India forging its path in human-relevant research.

The past decade has seen expeditious developments in our ability to grow and maintain a variety of human cells and tissues, with properties closely mimicking those in the human body. Prominent researchers and entrepreneurs from all over the world assembled in Hyderabad, India to discuss developments in this field that have not only aided fundamental understanding of organ development and disease processes but have served as good physiological models for toxicity testing and drug development. The speakers presented ingenious, cutting-edge technology and forward-thinking ideas. This report presents the salient aspects of their discussions, highlights the importance of identifying unmet needs, and discusses setting of standards that will help regulatory approvals as we move into a new era, with nominal animal use in research and effective drug discovery.

Mechanistic Understanding of the Olfactory Neuroepithelium Involvement Leading to Short-Term Anosmia in COVID-19 Using the Adverse Outcome Pathway Framework.

Loss of the sense of smell (anosmia) has been included as a COVID-19 symptom by the World Health Organization. The majority of patients recover the sense of smell within a few weeks postinfection (short-term anosmia), while others report persistent anosmia. Several studies have investigated the mechanisms leading to anosmia in COVID-19; however, the evidence is scattered, and the mechanisms remain poorly understood. Based on a comprehensive review of the literature, we aim here to evaluate the current knowledge and uncertainties regarding the mechanisms leading to short-term anosmia following SARS-CoV-2 infection. We applied an adverse outcome pathway (AOP) framework, well established in toxicology, to propose a sequence of measurable key events (KEs) leading to short-term anosmia in COVID-19. Those KEs are (1) SARS-CoV-2 Spike proteins binding to ACE-2 expressed by the sustentacular (SUS) cells in the olfactory epithelium (OE); (2) viral entry into SUS cells; (3) viral replication in the SUS cells; (4) SUS cell death; (5) damage to the olfactory sensory neurons and the olfactory epithelium (OE). This AOP-aligned approach allows for the identification of gaps where more research should be conducted and where therapeutic intervention could act. Finally, this AOP gives a frame to explain several disease features and can be linked to specific factors that lead to interindividual differences in response to SARS-CoV-2 infection.

A worldwide survey on the use of animal-derived materials and reagents in scientific experimentation.

The use of cell and tissue-based methods in basic, applied and regulatory science has been increasing exponentially. Animal-derived components, including serum, coating materials, growth factors and antibodies are routinely used in cell/tissue cultures and in general laboratory practices. In addition to ethical issues, the use and production of animal-derived materials and reagents raises many scientific concerns, generally associated with presence of undefined components and batch-to-batch variability, which may compromise experimental reproducibility. On the other hand, non-animal materials and reagents, such as human cells, alternatives to animal sera or non-animal recombinant antibodies, are becoming increasingly available, and their use is encouraged by the EU Directive 2010/63 and the Guidance Document on Good In vitro Method Practices (GIVIMP), published by the Organization for Economic Cooperation and Development (OECD). In an effort to map the current state of use of animal-derived reagents across different sectors and to identify the obstacles possibly hampering the implementation of non-animal derived alternatives, a global online survey addressed to scientists working on in vivo, in vitro, in silico methods, in academia as well as pharmaceutical or cosmetic companies, was conducted with the goal to understand: 1) the most commonly used animal-derived materials and reagents, 2) the main issues associated with the production and use of animal-derived materials and reagents, 3) the current level of knowledge on available non-animal alternative materials and reagents, and 4) what educational and information sources could be most useful or impactful to disseminate knowledge on non-animal alternatives. This paper provides an overview of the survey replies and discusses possible proposals to increase awareness, acceptance and use of non-animal ingredients.

Quality criteria for in vitro human pluripotent stem cell-derived models of tissue-based cells.

The advent of the technology to isolate or generate human pluripotent stem cells provided the potential to develop a wide range of human models that could enhance understanding of mechanisms underlying human development and disease. These systems are now beginning to mature and provide the basis for the development of in vitro assays suitable to understand the biological processes involved in the multi-organ systems of the human body, and will improve strategies for diagnosis, prevention, therapies and precision medicine. Induced pluripotent stem cell lines are prone to phenotypic and genotypic changes and donor/clone dependent variability, which means that it is important to identify the most appropriate characterization markers and quality control measures when sourcing new cell lines and assessing differentiated cell and tissue culture preparations for experimental work. This paper considers those core quality control measures for human pluripotent stem cell lines and evaluates the state of play in the development of key functional markers for their differentiated cell derivatives to promote assurance of reproducibility of scientific data derived from pluripotent stem cell-based systems.

Designing a national strategy to enable human-relevant research in India: A multistakeholder roundtable meeting report.

In the past few years, there has been a substantial increase in research and initiatives towards human-relevant technologies in India, particularly the use and development of microphysiological systems models in India. However, this rise has also been accompanied by significant roadblocks in the availability of infrastructure, training and education programs, supply chain issues, and lack of funding. A recent meeting between technology developers in academia and industry had led to suggestions to address these limitations. To take forward these suggestions, a first-of-its-kind multi-stakeholder meeting was held between participants from the Indian government and regulatory bodies, policy-makers, pharma companies, and academia. Several recommendations were proposed by the government and regulatory bodies to address the current limitations to developing MPS technologies in India. We end with strategies to achieve the proposed recommendations and envision that these initiatives would commence in the coming few months. This would assist in achieving the proposed goal of developing India as a key player in the development and usage of human-relevant technologies.

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.

The need to develop a framework for human-relevant research in India: Towards better disease models and drug discovery.

The low translational efficiency of animal models to humans, and the development of new-age methodologies that are human-cell based, is fuelling a paradigm change across the globe. In this perspectives paper, we discuss the current state of research, funding, and regulation in these 21st century technologies, including organoids and organ-on-chip in India. Recently, a road-map was drawn by Indian Council for Medical Research (ICMR) regarding alternatives to animals in research in India and it also held a special session in January 2018 to discuss latest developments in new human-relevant model systems. We document the regulatory and research landscape in this field in India. We also discuss the challenges present in this field which include lack of training and skills to handle embryonic or induced pluripotent stem cell (iPSC) lines, funding limitations, lack of domestic production of reagents leading to elevated costs, and lack of infrastructure, such as microfabrication facilities. In the end, we provide recommendations to enable innovation and application of human-relevant methodologies to develop India as a key player in this arena globally.