Biomedical Model Research Articles

Bridging the extracellular vesicle knowledge gap: insights from non-mammalian vertebrates, invertebrates, and early-diverging metazoans.

Extracellular vesicles (EVs) are lipid-enclosed structures that facilitate intercellular communication by transferring cargo between cells. Although predominantly studied in mammals, extracellular vesicles are ubiquitous across metazoans, and thus research in non-mammalian models is critical for fully elucidating extracellular vesicles biology. Recent advances demonstrate that extracellular vesicles mediate diverse physiological processes in non-mammalian vertebrates, including fish, amphibians, and reptiles. Piscine extracellular vesicles promote fin regeneration in zebrafish and carry heat shock proteins regulated by stress. Frog extracellular vesicles containing microRNAs modulate angiogenesis, while turtle extracellular vesicles coordinate reproductive functions. Venom from snakes contains extracellular vesicles that mirror the whole venom composition and interact with mammalian cells. Invertebrates also possess extracellular vesicles involved in immunity, development, and pathogenesis. Molluscan extracellular vesicles participate in shell formation and host interactions. Arthropod models, including Drosophila, genetically dissect conserved pathways controlling extracellular vesicles biogenesis and signalling. Nematode extracellular vesicles regulate larval development, animal communication, and ageing via conserved extracellular vesicles proteins. Ancient metazoan lineages utilise extracellular vesicles as well, with cnidarian extracellular vesicles regulating immunity and regeneration. Ultimately, expanding extracellular vesicles research beyond typical biomedical models to encompass phylogenetic diversity provides an unparalleled perspective on the conserved versus specialised aspects of metazoan extracellular vesicles roles over ∼500 million years. With a primary focus on the literature from the past 5years, this review aims to reveal fundamental insights into EV-mediated intercellular communication mechanisms shaping animal physiology.

Patients' and clinicians' views on shared decision making in cancer care: a qualitative study of Aotearoa New Zealand patients' and clinicians' perspectives.

Oncology stakeholders' view on shared decision making (SDM) in Aotearoa New Zealand is not well described in the literature. This study aimed to explore the perspectives of patients, clinicians and other cancer care stakeholders on shared decision making, and how and why shared decision making in cancer care can be viable and appropriate for patients and healthcare providers. Non-random, purposive sampling, combined with advertisement and snowball recruitment identified patient, whānau and healthcare provider participants for qualitative interviews. One-hour, semi-structured interviews were conducted to elicit perspectives on SDM. Data was analysed using Directed Content Analysis. Thirty-one participants were interviewed. SDM conceptualisations primarily concerned the sharing of information. Participants' stories highlighted patients' and whānau willingness to participate in making decisions about their care, to hold authority in this process, and to have their needs and preferences considered beyond the biomedical model. Patients and clinicians identified a range of factors moderating the extent of SDM, creating a gap between SDM expectations and practice. These data highlight the complexity of information needs in cancer care, and the discrepancy between patients' and their whānau and clinicians' views. This study increases our understanding of cancer stakeholders' expectations of SDM by highlighting various views on the meaning of SDM, informational needs and decision making engagement level. These findings can aid clinicians in creating space for patients to exercise their right to self-determination/rangatiratanga of health and wellbeing. Future work should explore approaches and implementations of SDM to facilitate an equitable experience of cancer care.

Learning functional conservation between human and pig to decipher evolutionary mechanisms underlying gene expression and complex traits

Assessment of genomic conservation between humans and pigs at the functional level can improve the potential of pigs as a human biomedical model. To address this, we developed a deep learning-based approach to learn the genomic conservation at the functional level (DeepGCF) between species by integrating 386 and 374 functional profiles from humans and pigs, respectively. DeepGCF demonstrated better prediction performance compared with the previous method. In addition, the resulting DeepGCF score captures the functional conservation between humans and pigs by examining chromatin states, sequence ontologies, and regulatory variants. We identified a core set of genomic regions as functionally conserved that plays key roles in gene regulation and is enriched for the heritability of complex traits and diseases in humans. Our results highlight the importance of cross-species functional comparison in illustrating the genetic and evolutionary basis of complex phenotypes.

Assessment of various standard fish diets on gut microbiome of platyfish Xiphophorus maculatus.

Diet is an external factor that affects the physiological baseline of research animals. It can shape gut microbiome, which can impact the host. As a result, dietary variation can challenge experimental reproducibility and data integration across studies when not appropriately considered. To control for diet-induced variation, reference diets have been developed for common biomedical models. However, such reference diets have not yet been developed for nontraditional model organisms, such as Xiphophorus species. In this study, we compared two diets designed for zebrafish, a commercial zebrafish diet (Gemma and GEM), and a proposed zebrafish reference diet developed by the Watts laboratory at the University of Alabama at Birmingham (WAT) to the Xiphophorus Genetic Stock Center custom diet (CON) to evaluate the influence of diet on the Xiphophorus gut microbiome. Xiphophorus maculatus were fed the three diets from 2 to 6 months of age. Feces were collected and the gut microbiome was assessed using 16S rRNA sequencing every month. We observed substantial diet-driven variation in the gut microbiome. Our results indicate that diets developed specifically for zebrafish can affect the gut microbiome composition and may not be optimal for Xiphophorus.

Using transfer learning-based causality extraction to mine latent factors for Sjögren's syndrome from biomedical literature

Understanding causality is a longstanding goal across many different domains. Different articles, such as those published in medical journals, disseminate newly discovered knowledge that is often causal. In this paper, we use this intuition to build a model that leverages causal relations to unearth factors related to Sjögren's syndrome from biomedical literature. Sjögren's syndrome is an autoimmune disease affecting up to 3.1 million Americans. Due to the uncommon nature of the illness, symptoms across different specialties coupled with common symptoms of other autoimmune conditions such as rheumatoid arthritis, it is difficult for clinicians to diagnose the disease timely. Due to the lack of a dedicated dataset for causal relationships built from biomedical literature, we propose a transfer learning-based approach, where the relationship extraction model is trained on a wide variety of datasets. We conduct an empirical analysis of numerous neural network architectures and data transfer strategies for causal relation extraction. By conducting experiments with various contextual embedding layers and architectural components, we show that an ELECTRA-based sentence-level relation extraction model generalizes better than other architectures across varying web-based sources and annotation strategies. We use this empirical observation to create a pipeline for identifying causal sentences from literature text, extracting the causal relationships from causal sentences, and building a causal network consisting of latent factors related to Sjögren's syndrome. We show that our approach can retrieve such factors with high precision and recall values. Comparative experiments show that this approach leads to 25% improvement in retrieval F1-score compared to several state-of-the-art biomedical models, including BioBERT and Gram-CNN. We apply this model to a corpus of research articles related to Sjögren's syndrome collected from PubMed to create a causal network for Sjögren's syndrome. The proposed causal network for Sjögren's syndrome will potentially help clinicians with a holistic knowledge base for faster diagnosis.

Demographic change and urban health: Towards a novel agenda for delivering sustainable and healthy cities for all

The focus is on the demographic drivers and demographic implications of urban health and wellbeing in towns and cities across the globe. The aim is to identify key linkages between demographic change and urban health – subjects of two largely disparate fields of research and practice – with a view to informing arguments and advocacy for urban health while identifying research gaps and priorities. The core arguments are threefold. First, urban health advocates should express a globalized perspective on demographic processes, encompassing age-structural shifts in addition to population growth and decrease, and acknowledging their uneven spatial distributions within and between urban settings in different contexts. Second, advocates should recognize the dynamic and transformational effects that demographic forces will exert on economic and political systems in all urban settings. While demographic forces underpin the production of (intra)urban inequities in health, they also present opportunities to address those inequities. Third, a demographic perspective may help to extend urban health thinking and intervention beyond a biomedical model of disease, highlighting the need for a multi-generational view of the changing societal bases for urban health, and enjoining significant advances in how interested parties collect, manage, analyse, and use demographic data. Accordingly, opportunities are identified to increase the availability of granular and accurate data to enable evidence-informed action on the demographic/health nexus.

Rapid Prototyping Technologies: 3D Printing Applied in Medicine.

Three-dimensional printing technology has been used for more than three decades in many industries, including the automotive and aerospace industries. So far, the use of this technology in medicine has been limited only to 3D printing of anatomical models for educational and training purposes, which is due to the insufficient functional properties of the materials used in the process. Only recent advances in the development of innovative materials have resulted in the flourishing of the use of 3D printing in medicine and pharmacy. Currently, additive manufacturing technology is widely used in clinical fields. Rapid development can be observed in the design of implants and prostheses, the creation of biomedical models tailored to the needs of the patient and the bioprinting of tissues and living scaffolds for regenerative medicine. The purpose of this review is to characterize the most popular 3D printing techniques.

A multi-omics analysis identifies molecular features associated with fertility in heifers (Bos taurus)

Infertility or subfertility is a critical barrier to sustainable cattle production, including in heifers. The development of heifers that do not produce a calf within an optimum window of time is a critical factor for the profitability and sustainability of the cattle industry. In parallel, heifers are an excellent biomedical model for understanding the underlying etiology of infertility because well-nourished heifers can still be infertile, mostly because of inherent physiological and genetic causes. Using a high-density single nucleotide polymorphism (SNP) chip, we collected genotypic data, which were analyzed using an association analysis in PLINK with Fisher’s exact test. We also produced quantitative transcriptome data and proteome data. Transcriptome data were analyzed using the quasi-likelihood test followed by the Wald’s test, and the likelihood test and proteome data were analyzed using a generalized mixed model and Student’s t-test. We identified two SNPs significantly associated with heifer fertility (rs110918927, chr12: 85648422, P = 6.7 × 10−7; and rs109366560, chr11:37666527, P = 2.6 × 10−5). We identified two genes with differential transcript abundance (eFDR ≤ 0.002) between the two groups (Fertile and Sub-Fertile): Adipocyte Plasma Membrane Associated Protein (APMAP, 1.16 greater abundance in the Fertile group) and Dynein Axonemal Intermediate Chain 7 (DNAI7, 1.23 greater abundance in the Sub-Fertile group). Our analysis revealed that the protein Alpha-ketoglutarate-dependent dioxygenase FTO was more abundant in the plasma collected from Fertile heifers relative to their Sub-Fertile counterparts (FDR < 0.05). Lastly, an integrative analysis of the three datasets identified a series of molecular features (SNPs, gene transcripts, and proteins) that discriminated 21 out of 22 heifers correctly based on their fertility category. Our multi-omics analyses confirm the complex nature of female fertility. Very importantly, our results also highlight differences in the molecular profile of heifers associated with fertility that transcend the constraints of breed-specific genetic background.

Exploring the Evidence for the Paradigms of Recovery and Social Work Converging in Mental Health Service Delivery Worldwide: Reflections from an Irish Case Study.

Recovery within mental health service delivery is no longer a new consideration in the Western world. However, it is well-documented how challenging its implementation and translation to practice and reality have been in contemporary mental health systems. In conjunction with this, mental health social work is continuously being challenged and debated in relation to its role, responsibilities, and identity in service delivery. This is largely the consequence of the continued dominance of the biomedical model in relation to service delivery. Yet, if we critically reflect on the philosophy and ethos of recovery, it becomes very clear that social work should be the key profession to lead the development and improvement of recovery-orientated services across the globe. To illustrate this argument, the authors first draw on empirical research undertaken by the lead author within the Republic of Ireland on how recovery is socially constructed within mental health service delivery. The key stakeholders involved in the Irish study included professionals, service users, family members, and policy influencers, with participants taking part in semi-structured interviews. Secondly, the authors reflect on some of the findings from this Irish study, presenting an argument for not only a more significant role for social work in an Irish mental health context but also making comparisons from an international perspective. This includes exploring the role of critical social work traditions for supporting services to move beyond a philosophy of recovery that has, to date, overlooked the intersectional injustices and inequalities faced by hard-to-reach populations. Finally, the authors conclude by providing some possibilities for how the paradigms of social work and recovery can and should continue to converge towards each other, opening a space for social work to become a more dominant perspective within mental health systems worldwide.

“Winging It”: An Exploration of the Self-Perceived Professional Identity of Social Prescribing Link Workers

The practice of social prescribing (SP) has been rapidly expanding throughout the UK in recent years. The role of SP link workers (SPLWs) currently has no nationally prescribed requirements in terms of qualifications, background, or experience. This qualitative study of 13 SPLWs using semi-structured interviews is believed to be the first exploration of perceptions of their professional identity and the agency and structure within their roles. SPLWs reported feeling caught between biomedical and biopsychosocial models of health. Some identified with clinical healthcare teams, whilst others preferred non-medical and community-based identities. SPLWs valued professional flexibility and freedom, though were concerned this was becoming increasingly restricted. They reported filling gaps in the health system and absorbing more risk and complexity than they believed was reflected in their training or pay. Despite this, SPLWs demonstrated consistent core values of person-centredness, holistic practice, and a strength-based approach. A more consistent approach to professional identity is recommended as a way forward for SP.

An optimized prime editing system for efficient modification of the pig genome.

Prime editing (PE) is a recent gene editing technology that can mediate insertions or deletions and all twelve types of base-to-base conversions. However, its low efficiency hampers the application in creating novel breeds and biomedical models, especially in pigs and other important farm animals. Here, we demonstrate that the pig genome is editable using the PE system, but the editing efficiency was quite low as expected. Therefore, we aimed to enhance PE efficiency by modulating both exogenous PE tools and endogenous pathways in porcine embryonic fibroblasts (PEFs). First, we modified the pegRNA by extending the duplex length and mutating the fourth thymine in a continuous sequence of thymine bases to cytosine, which significantly enhanced PE efficiency by improving the expression of pegRNA and targeted cleavage. Then, we targeted SAMHD1, a deoxynucleoside triphosphate triphosphohydrolase (dNTPase) that impedes the reverse transcription process in retroviruses, and found that treatment with its inhibitor, cephalosporin C zinc salt (CPC), increased PE efficiency up to 29-fold (4-fold on average), presumably by improving the reverse transcription process of Moloney murine leukemia virus reverse transcriptase (M-MLV RT) in the PE system. Moreover, PE efficiency was obviously improved by treatment with a panel of histone deacetylase inhibitors (HDACis). Among the four HDACis tested, panobinostat was the most efficient, with an efficiency up to 122-fold (7-fold on average), partly due to the considerable HDACi-mediated increase in transgene expression. In addition, the synergistic use of the three strategies further enhanced PE efficiency in PEFs. Our study provides novel approaches for optimization of the PE system and broadens the application scope of PE in agriculture and biomedicine.

Screening depression and anxiety in Indigenous peoples: A global scoping review.

Indigenous peoples' worldviews are intricately interconnected and interrelated with their communities and the environments in which they live. Their worldviews also manifest in a holistic view of health and well-being, which contrasts with those of the dominant western biomedical model. However, screening depression and/or anxiety in Indigenous peoples often occurs using standard western tools. Understandably, the cultural appropriateness of these tools has been questioned. The purpose of this scoping review was to map the literature that used any type of tool to screen depression or anxiety in Indigenous adults globally. A systematic scoping review method was used to search databases including, but not limited to, CINAHL, PubMed, Scopus and Google. Database-specific search terms associated with Indigenous peoples, depression and anxiety, and screening tools were used to identify literature. In addition, citation searches of related systematic reviews and relevant websites were conducted. The data set was limited to English language publications since database inception. Fifty-four publications met the review's inclusion criteria. Most studies were completed in community settings using standard western depression and anxiety screening tools. Thirty-three different tools were identified, with the Patient Health Questionnaire-9 being the most frequently used. The review's findings are concerning given repeated calls for culturally appropriate screening tools to be used with Indigenous peoples. Although there has been some work to cross-culturally adapt depression screening tools for specific Indigenous populations, clearly more clinicians and researchers need to be aware of, and use, culturally appropriate approaches to screening.

Psychosocial well-being in Long-Term Care in the Wake of COVID-19: Findings from a Qualitative Study in New Zealand

Drawing on Mason Durie’s (1985) New Zealand Whare Tapa Whā model of health (spiritual, emotional, physical, and family domains), the goal was to link a model of well-being with the lived reality for long-term care residents and bereaved family members during COVID-19. Interviews were conducted with five residents and six family members of previous residents of one long-term care in one urban centre between July and September 2020. The increased demands imposed by the pandemic highlighted the gaps in well-being for residents and families. In particular, the inability to connect with family during COVID-19 restrictions reduced perceptions of well-being for residents. Study findings indicate that the provision of well-being for older adults and families in long-term care extends beyond the narrow bounds of the biomedical model. The Whare Tapa Whā model provides a valuable framework describing the holistic balance needed between the four health domains.

Addiction phobia: Foucault, abstract governance, and the fascination with materiality in contemporary critical studies of addiction

ABSTRACT This article explores how the field of critical addiction studies – which can be traced back to the late twentieth century – has used Foucauldian social theory on governance to challenge dominant biomedical and moralistic models of addiction and to account for the ways in which addiction discourse and practice reproduce purifying, essentialist and singular assumptions about behaviour, bodies and desire. Starting from Foucault’s late critique of the neoliberalist phobia of the state, and Dean and Villadsen’s subsequent analysis of how this phobia ironically appears to haunt Foucauldian as well as other versions of poststructuralist social theory, the article asks whether a similar phobic tendency can be identified in Foucauldian accounts of addiction, although in this case directed towards addiction as a discursive centre. Analysing accounts of addiction provided by several critical addiction scholars, the article investigates how this more general tendency in relation to Foucauldian and poststructuralist theory is enacted in and structures a number of key points in contemporary critiques of addiction. Through detailed analyses of how critics have framed addiction as governmentality and an epidemics of the will, related addiction to habit, dealt with tensions within the discourse of addiction, raised issues of materiality, and aligned themselves with the heterogeneity of bodies, behaviours, and desires, the article claims that the field of critical addiction studies reduces addiction to abstract governance and avoids seriously engaging with the structure and dynamics of addiction from a decentred social theoretical perspective.

Developmental dynamics of the single nucleus regulatory landscape of pig hippocampus.

The hippocampus is a brain region associated with memory, learning and spatial navigation, its aging-related dysfunction is a common sign of Alzheimer's disease. Pig is a good model for human neurodegenerative disease, but our understanding of the regulatory program of the pig hippocampus and its cross-species conservation in humans remains limited. Here, we profiled chromatin accessibility in 33,409 high-quality nuclei and gene expression in 8,122 high-quality nuclei of the pig hippocampus at four postnatal stages. We identified 510,908 accessible chromatin regions (ACRs) in 12 major cell types, among which progenitor cells such as neuroblasts and oligodendrocyte progenitor cells showed a dynamic decrease from early to later developmental stages. We revealed significant enrichment of transposable elements in cell type-specific ACRs, particularly in neuroblasts. We identified oligodendrocytes as the most prominent cell type with the greatest number of genes that showed significant changes during the development. We identified ACRs and key transcription factors underlying the trajectory of neurogenesis (such as POU3F3 and EGR1) and oligodendrocyte differentiation (RXRA and FOXO6). We examined 27 Alzheimer's disease-related genes in our data and found that 15 showed cell type-specific activity (TREM2, RIN3 and CLU), and 15 genes displayed age-associated dynamic activity (BIN1, RABEP1 and APOE). We intersected our data with human genome-wide association study results to detect neurological disease-associated cell types. The present study provides a single nucleus-accessible chromatin landscape of the pig hippocampus at different developmental stages and is helpful for the exploration of pigs as a biomedical model in human neurodegenerative diseases.

Zebrafish Danio rerio exhibit positive growth profiles when fed dietary yeast and bacterial‐based single‐cell protein as a replacement for fish protein hydrolysate

AbstractObjectiveThe value of Zebrafish Danio rerio as a preclinical biomedical model has increased as nutritionally complete diets are being developed. Consequently, nutrients and nutrient sources can be used in evaluating the health status of Zebrafish, providing information that can be translated to human health. We have investigated the impact of commercially produced bacterial (MRD‐Pro) and yeast (DY‐Pro) single‐cell protein sources in formulated Zebrafish diets.MethodsThirty‐five days after fertilization Zebrafish were randomized to one of five dietary treatments including FPH100 (a control diet with primarily fish protein hydrolysate [FPH] as the protein source), MRD50 and MRD100 (diets that replaced half or all of the FPH with MRD, a bacterial protein), or DY50 and DY100 (diets that replaced half or all of the FPH with DY, a yeast protein) for 8 weeks (n = 8 tanks/diet treatment, 14 fish/tank).ResultFemale terminal wet weight was the same among all diets; however, male terminal wet weight was increased in fish consuming MRD diets. In addition, carcass lipid content was significantly lower in females consuming the DY and MRD diets than those fed FPH. Male lipid content was the same among all diets.ConclusionResults demonstrate that single‐cell protein sources are suitable replacements for FPH and, in female populations, may impart health benefits related to lean matter production and reduced adiposity.

MyKOA-Cope: the development of a culturally relevant integrative group psychological intervention for people with chronic knee osteoarthritis pain

Introduction: Knee osteoarthritis is a highly prevalent musculoskeletal condition that causes chronic pain and psychological distress. The biological aspects of arthritis pain can be effectively managed with medication, physiotherapy and surgical procedures. However, no known psychological interventions to manage the psychological aspects of chronic pain have been developed in Sri Lanka.Objective: The study aimed to develop a culturally relevant integrative group psychological intervention for patients with chronic knee osteoarthritis pain.Methods: The first phase involved a literature review of existing psychological interventions on chronic pain management, which was used to develop a culturally relevant group psychological intervention named as “MyKOA-Cope: Psychological intervention for chronic knee osteoarthritis”. In the second phase, a Delphi study and a focus group discussion were conducted to evaluate the feasibility of the newly developed intervention.Results: The MyKOA-Cope is a six-session, in-person group intervention that lasts 45-50 minutes per session. These sessions include: 1) orientation to the intervention; 2) relaxation training; 3) exercise and pacing; pleasant activity scheduling; 4) identify negative automatic thoughts; 5) cognitive restructuring and calming selfstatements and 6) termination and maintenance strategies.Conclusion: The present study developed a culturally appropriate psychological intervention to enhance paincoping skills among patients with chronic knee osteoarthritis. This intervention has the potential to address the psychological aspects of chronic pain and contribute to the biomedical model. Future research can validate and tailor the MyKOA-Cope to suit the needs of patients with different illness conditions, literacy levels, and those who speak in Tamil in Sri Lanka.

Localizing in-domain adaptation of transformer-based biomedical language models

In the era of digital healthcare, the huge volumes of textual information generated every day in hospitals constitute an essential but underused asset that could be exploited with task-specific, fine-tuned biomedical language representation models, improving patient care and management. For such specialized domains, previous research has shown that fine-tuning models stemming from broad-coverage checkpoints can largely benefit additional training rounds over large-scale in-domain resources. However, these resources are often unreachable for less-resourced languages like Italian, preventing local medical institutions to employ in-domain adaptation. In order to reduce this gap, our work investigates two accessible approaches to derive biomedical language models in languages other than English, taking Italian as a concrete use-case: one based on neural machine translation of English resources, favoring quantity over quality; the other based on a high-grade, narrow-scoped corpus natively written in Italian, thus preferring quality over quantity. Our study shows that data quantity is a harder constraint than data quality for biomedical adaptation, but the concatenation of high-quality data can improve model performance even when dealing with relatively size-limited corpora. The models published from our investigations have the potential to unlock important research opportunities for Italian hospitals and academia. Finally, the set of lessons learned from the study constitutes valuable insights towards a solution to build biomedical language models that are generalizable to other less-resourced languages and different domain settings.

The instituted and the real in the training of community health agents: a scoping review

Objective: To map the formation processes and ongoing education actions experienced by Community Health Agents (CHAs) in the context of family health, anchored in the concept of culture. Methodology: Scope review following the Joanna Briggs Institute (JBI) methodology and guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR). The search in databases such as BVS, EBSCO – Academic Search Premier, CINAHL, GreenFILE, SocINDEX, Embase, ERIC, Global Index Medicus, PUBMED, Scielo, Scopus, WOS, took place in November and December 2022. The search terms were: Community Health Workers, Professional Training, Continuing Education, Family Health Strategy, Primary Health Care. Studies analyzing training experiences and actions of Permanent Education in Health (PEH) for CHAs in the context of family health were included. Endnote and Rayyan software were used in managing the selection of findings. The review protocol was registered on the Open Science Framework (OSF). Results: The sample included 25 studies, generating two categories: The primacy of instrumental technical training culture; and The biomedical culture guiding PEH. CHA training involves disinvestment and invisibility, focusing on the biomedical model. On the other hand, even if sporadic, PEH actions are guided by emerging health themes. Final Considerations: The formative processes and PEH for CHAs involve paths of construction and deconstruction, progress, and setbacks, based on a culture that often restricts established rights.

The tree shrew as a new animal model for the study of periodontitis.

Periodontitis is an inflammatory, infectious disease of polymicrobial origin that can damage tooth-supporting bone and tissue. Tree shrews, evolutionarily closer to humans than commonly used rodent models, have been increasingly used as biomedical models. However, a tree shrew periodontitis model has not yet been established. Periodontitis was induced in male tree shrews/Sprague-Dawley rats by nylon thread ligature placement around the lower first molars. Thereafter, morphometric and histological analyses were performed. The distance from the cemento-enamel junction to the alveolar bone crest was measured using micro-computed tomography. Periodontal pathological tissue damage, inflammation and osteoclastogenesis were assessed using haematoxylin and eosin staining and quantitative immunohistochemistry, respectively. Post-operatively, gingival swelling, redness and spontaneous bleeding were observed in tree shrews but not in rats. After peaking, bone resorption decreased gradually until plateauing in tree shrews. Contrastingly, rapid and near-complete bone loss was observed in rats. Inflammatory infiltrates were observed 1 week post operation in both models. However, only the tree shrew model transitioned from acute to chronic inflammation. Our study revealed that a ligature-induced tree shrew model of periodontitis partly reproduced the pathological features of human periodontitis and provided theoretical support for using tree shrews as a potential model for human periodontitis.