Controversies in spine research: organ culture versus in vivo models for studies of the intervertebral disc

Intervertebral disc degeneration is a common cause of low back pain, the leading cause of disability worldwide. Appropriate preclinical models for intervertebral disc research are essential to achieving a better understanding of underlying pathophysiology and for the development, evaluation, and translation of more effective treatments. To this end, in vivo animal and ex vivo organ culture models are both widely used by spine researchers; however, the relative strengths and weaknesses of these two approaches are a source of ongoing controversy. In this article, members from the Spine and Preclinical Models Sections of the Orthopedic Research Society, including experts in both basic and translational spine research, present contrasting arguments in support of in vivo animal models versus ex vivo organ culture models for studies of the disc, supported by a comprehensive review of the relevant literature. The objective is to provide a deeper understanding of the respective advantages and limitations of these approaches, and advance the field toward a consensus with respect to appropriate model selection and implementation. We conclude that complementary use of several model types and leveraging the unique advantages of each is likely to result in the highest impact research in most instances

Caspase-3 Mediates the Pathogenic Effect of \u3cem\u3e Yersinia pestis \u3c/em\u3e YopM in Liver of C57BL/6 Mice and Contributes to YopM\u27s Function in Spleen

The virulence protein YopM of the plague bacterium Yersinia pestis has different dominant effects in liver and spleen. Previous studies focused on spleen, where YopM inhibits accumulation of inflammatory dendritic cells. In the present study we focused on liver, where PMN function may be directly undermined by YopM without changes in inflammatory cell numbers in the initial days of infection, and foci of inflammation are easily identified. Mice were infected with parent and ΔyopM-1 Y. pestis KIM5, and effects of YopM were assessed by immunohistochemistry and determinations of bacterial viable numbers in organs. The bacteria were found associated with myeloid cells in foci of inflammation and in liver sinusoids. A new in-vivo phenotype of YopM was revealed: death of inflammatory cells, evidenced by TUNEL staining beginning at d 1 of infection. Based on distributions of Ly6G+, F4/80+, and iNOS+ cells within foci, the cells that were killed could have included both PMNs and macrophages. By 2 d post-infection, YopM had no effect on distribution of these cells, but by 3 d cellular decomposition had outstripped acute inflammation in foci due to parent Y. pestis, while foci due to the Δ-1yopM strain still contained many inflammatory cells. The destruction depended on the presence of both PMNs in the mice and YopM in the bacteria. In mice that lacked the apoptosis mediator caspase-3 the infection dynamics were novel: the parent Y. pestis was limited in growth comparably to the ΔyopM-1 strain in liver, and in spleen a partial growth limitation for parent Y. pestis was seen. This result identified caspase-3 as a co-factor or effector in YopM\u27s action and supports the hypothesis that in liver YopM\u27s main pathogenic effect is mediated by caspase-3 to cause apoptosis of PMNs

AChBP-targeted α-conotoxin correlates distinct binding orientations with nAChR subtype selectivity

Neuronal nAChRs are a diverse family of pentameric ion channels with wide distribution throughout cells of the nervous and immune systems. However, the role of specific subtypes in normal and pathological states remains poorly understood due to the lack of selective probes. Here, we used a binding assay based on acetylcholine-binding protein (AChBP), a homolog of the nicotinic acetylcholine ligand-binding domain, to discover a novel α-conotoxin (α-TxIA) in the venom of Conus textile. α-TxIA bound with high affinity to AChBPs from different species and selectively targeted the α3β2 nAChR subtype. A co-crystal structure of Ac-AChBP with the enhanced potency analog TxIA(A10L), revealed a 20° backbone tilt compared to other AChBP–conotoxin complexes. This reorientation was coordinated by a key salt bridge formed between Arg5 (TxIA) and Asp195 (Ac-AChBP). Mutagenesis studies, biochemical assays and electrophysiological recordings directly correlated the interactions observed in the co-crystal structure to binding affinity at AChBP and different nAChR subtypes. Together, these results establish a new pharmacophore for the design of novel subtype-selective ligands with therapeutic potential in nAChR-related diseases

SNP‐based heritability and genetic architecture of tarsal osteochondrosis in North American Standardbred horses

Supplementary data for publication: AM McCoy, EM Norton, AM Kemper, SK Beeson, JR Mickelson, ME McCue. (2019). SNP‐based heritability and genetic architecture of tarsal osteochondrosis in North American Standardbred horses, Animal Genetics, 50(1); https://doi.org/10.1111/age.1273

Identification and Validation of Risk Loci for Osteochondrosis in Standardbreds.

Supplementary data for publication: AM McCoy, SK Beeson, S Lykkjen, SL Ralston, JR Mickelson, ME McCue. (2016). Identification and Validation of Risk Loci for Osteochondrosis in Standardbreds. BMC Genomics, 201617:41, DOI: 10.1186/s12864-016-2385-

Identification and Validation of Genetic Variants Predictive of Gait in Standardbred Horses

Supplementary data for publication: Annette M. McCoy, Samantha K. Beeson, Carl-Johan Rubin, Leif Andersson, Paul Caputo, Sigrid Lykkjen, Alison Moore, Richard J. Piercy, James R. Mickelson, Molly E. McCue. (2019). Identification and Validation of Genetic Variants Predictive of Gait in Standardbred Horses. PLoS Genet. 2019 May 28;15(5): e100814

The Scope of Big Data in One Medicine: Unprecedented Opportunities and Challenges

Advances in high-throughput molecular biology and electronic health records (EHR), coupled with increasing computer capabilities have resulted in an increased interest in the use of big data in health care. Big data require collection and analysis of data at an unprecedented scale and represents a paradigm shift in health care, offering (1) the capacity to generate new knowledge more quickly than traditional scientific approaches; (2) unbiased collection and analysis of data; and (3) a holistic understanding of biology and pathophysiology. Big data promises more personalized and precision medicine for patients with improved accuracy and earlier diagnosis, and therapy tailored to an individual’s unique combination of genes, environmental risk, and precise disease phenotype. This promise comes from data collected from numerous sources, ranging from molecules to cells, to tissues, to individuals and populations—and the integration of these data into networks that improve understanding of heath and disease. Big data-driven science should play a role in propelling comparative medicine and “one medicine” (i.e., the shared physiology, pathophysiology, and disease risk factors across species) forward. Merging of data from EHR across institutions will give access to patient data on a scale previously unimaginable, allowing for precise phenotype definition and objective evaluation of risk factors and response to therapy. High-throughput molecular data will give insight into previously unexplored molecular pathophysiology and disease etiology. Investigation and integration of big data from a variety of sources will result in stronger parallels drawn at the molecular level between human and animal disease, allow for predictive modeling of infectious disease and identification of key areas of intervention, and facilitate step-changes in our understanding of disease that can make a substantial impact on animal and human health. However, the use of big data comes with significant challenges. Here we explore the scope of “big data,” including its opportunities, its limitations, and what is needed capitalize on big data in one medicine