Tissue in horses refers to the various types of biological material that make up the body of the animal, including muscle, connective, epithelial, and nervous tissues. Each type of tissue has specific functions and characteristics, contributing to the overall physiology and health of the horse. Muscle tissue is responsible for movement and locomotion, connective tissue provides structural support and protection, epithelial tissue covers body surfaces and lines cavities, and nervous tissue is involved in transmitting signals for communication and coordination within the body. The study of equine tissue encompasses aspects such as growth, repair, and response to injury or disease. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and pathology of different tissue types in horses, offering insights into their role in equine health and disease management.
Meeremans M, Devriendt B, Bairiot S, Van Poucke M, Peelman L, Demeyere K, Meyer E, Van Vlierberghe S, De Schauwer C.Macrophages play key roles in tissue homeostasis and regeneration-associated inflammation. Unlike humans, a reliable protocol to obtain and polarise equine monocyte-derived macrophages is lacking. In this study the polarisation of equine macrophages, derived from CD172a peripheral blood monocytes is described. After differentiation, IFN-γ/LPS or IL-4 were used to induce pro- and anti-inflammatory phenotypes, respectively. Evaluation criteria included morphology, mRNA (RT-qPCR) and protein expression (flow cytometry, immunofluorescence), nitric oxide and arginase production, cytokine secretion...
James AL, Vettorato E, Moura RA, Azevedo TMBPR, Mallicote MF, Chiavaccini L.Sedation with α₂-agonists can impair microcirculation and oxygen delivery. This prospective randomized crossover study investigated whether administering acepromazine maleate before detomidine hydrochloride maintains higher peripheral tissue oxygen saturation (StO₂) in sedated horses. Eight healthy adult horses randomly received intravenous detomidine (10 μg/kg) either alone (D) or in combination with acepromazine (20 μg/kg; DA), with a one-week washout. Hemoglobin concentration and central venous oxygen saturation (ScvO₂) were measured at baseline. Tissue oxygen saturation, tissue ...
Graide H, Duysens J, Frank T, Mouithys-Mickalad A, Niesten A, Sandersen C, Ceusters J, Serteyn D.Musculoskeletal pathologies present challenges in athletic horses, often leading to functional impairment. The slow or limited regenerative capacity of bone, joint, and tendon/ligament injuries, coupled with the limitations of conventional treatments, highlights the need for innovative therapies such as ortho-biologics and mesenchymal stem/stroma cells. Traditional 2D cell culture systems with fetal bovine serum (FBS) fail to replicate the complexity of the in vivo environment, whereas 3D cultures more accurately mimic native tissue architecture and cell-cell interactions. This study describes...
Profaska M, Zarzycka M, Dubniewicz K, Witkowski M, Wieczorek J, Gil D, Wafula S, Lanh DK, Kotula-Balak M.Mare endometrosis remains a poorly understood pathological process. Objective: Mare endometrial tissue with endometrosis was used to determine the effects of relaxin (RLX). Healthy tissues that were left untreated (H), or treated with vehicle (Hveh), and tissues with endometrosis that were left untreated (E), treated with vehicle (Eveh), and treated with RLX (10, 25, 50 nM; ER) were used for an ex vivo system for 72 h. Methods: Tissue histological examination, and immunoenzymatic measurement of the concentrations of transforming growth factor β (TGF-β), interleukins (IL-6 and IL-8), and pr...
Sabzpoosh M, Hoveizi E, Gooraninejad S.This study aimed to extract and isolate endometrial stromal cells from Arabian mares and investigate their growth and differentiation potential. Endometrial biopsies were obtained from three healthy 6-year-old Arabian mares using a standardized, minimally invasive protocol. The isolated cells were characterized using flow cytometry and differentiation analysis. Flow cytometry revealed mesenchymal markers CD90 (95.2%) and CD105 (97.4%) and hematopoietic markers CD34 (1.17%) and CD45 (0.339%). The cells exhibited differentiation potential into adipocytes, osteoblasts, and chondrocytes. The findi...
Da Silva-Álvarez E, Martín-Cano FE, Alonso JM, Becerro-Rey L, Zabalo-Palomo C, Gil MC, Peña FJ, Ortega-Ferrusola C.This study aims to characterize and compare the uterine fluid proteome and cytokine profile of reproductively healthy mares (HM; n = 15) and mares with Streptococcus equi subsp. zooepidemicus (S. zooepidemicus)-associated endometritis (SAE; n = 9). Uterine flush samples collected during the follicular phase were analyzed by shotgun proteomics and multiplex cytokine assays. Equine proteins were mapped to human orthologs, and enrichment and network analyses were performed using g:Profiler, Metascape, ToppGene, and STRING/MCODE. SAE mares showed higher levels of IL-1α, IL-1β, GRO, IL12p...
Iwasaki N, Llewellyn J, Brown J, Zamboulis DE, Finding EJT, Wheeler-Jones CPD, Thorpe CT.Tendon degeneration is common, and its risk increases with age both in humans and horses. Tendon regeneration and healing is limited due to inherent low cell density and vascularisation, and current treatments are insufficient as indicated by scar tissue formation and a high re-injury rate. The tendon vasculature plays a crucial role in tendon homeostasis, regeneration and healing, making it a potential therapeutic target. However, the effect of ageing on the tendon microvasculature is poorly understood. Here, we provide the first comprehensive characterisation of the tendon microvasculature. ...
Partusch L, Rutland CS, Martens A, Du Cheyne C, De Spiegelaere W, Michler JK.Exuberant granulation tissue (EGT) is a second intention wound healing disorder. It commonly occurs in the distal limb of horses. EGT causes significant increase in the duration and cost of treatment, potentially leading to the decision not to pursue treatment and euthanize the patient. The underlying pathomechanisms of this fibroproliferative disorder remain unclear, particularly in terms of collagen composition and the association between myofibroblasts and blood vessels. This study investigated the collagen composition in naturally occurring EGT following trimming in 19 horses (EGT group). ...
Parker JL, Berghaus LJ, Gordon J, Mathews L, Akinde MA, Hall DB, Peroni JF.Mesenchymal stromal cells (MSCs) support wound healing through immunomodulation and by promoting tissue organization. Cell tracking studies demonstrate that MSCs must 'home' to injuries in order to participate in reparative processes. It has been reported that in vivo cell tracking labels, including superparamagnetic iron oxide particles (SPIOs), can alter MSC homing. Homing is thought to occur in coordinated steps including tethering, activation, arrest, diapedesis, and migration, guided by chemotactic stimuli. Equine distal limb injuries, which are commonly treated with MSCs, possess a disti...
DI Stefano DA, Coccoluto L, Panina-Bordignon P, Brambilla E, Ruffini F, Murtaj V, Orlando F, Colombo M, Frigerio C, DI Bona A, Recupero D, Morroni M....Bone grafting is a surgical procedure that involves the use of bone tissue or bone substitutes to repair damaged bone. In dentistry and maxillofacial surgery, bone graft substitutes from various sources are commonly used. Given their critical role in clinical outcomes, it is essential to thoroughly investigate the biological and mechanical properties of these materials. Methods: In this in vitro study, we evaluated the biological properties of two equine-derived bone graft substitutes in comparison to β-tricalcium phosphate. The materials included one equine-derived graft containing hydrolyze...
Mojsym W, Kowalik S, Chałabis-Mazurek A, Janczarek I, Kędzierski W.Some correlations between serum Cu, Zn and Se and cytokines have been reported in humans. Especially, the Cu:Zn ratio corresponded with inflammation. To date, relationships between microelements and proinflammatory proteins are poorly understood in horses. The aim of the study was to evaluate whether Cu, Zn and Se may influence turnover of IL-6, IL-8 and tissue factor (TF) in breeding and working horses. Blood samples obtained from 66 horses were analysed. There were 37 pregnant broodmares of different breeds, 13 barren broodmares and 16 race Thoroughbred horses. Serum Cu, Zn and Se concentrat...
Austin MMP, Ivey JLZ, Shepherd EA, Myer PR.Starvation in horses presents critical welfare, economic, and management challenges with underlying molecular mechanisms of metabolic modification and recovery left poorly defined. Prolonged caloric deprivation induces significant systemic shifts in carbohydrate, protein, and lipid metabolism, reflected in coordinated changes in tissue-specific gene expression. This review synthesizes current knowledge on equine metabolic responses to starvation, emphasizing pathways found through RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction (RT-qPCR) studies. Molecular investi...
Bollens J, Gheysen L, Verkade M, Stael J, Martens A, Segers P.Postoperative incisional complications are common in horses following abdominal surgery, which typically involves an incision through the abdominal wall along the linea alba. The linea alba is a fibrous band running in the craniocaudal direction along the ventral abdomen. This incision is closed with sutures, where the choice of suture pattern and surgical technique has shown to influence the rate of complications. Therefore, this study investigated how different suture patterns and variations influence the stresses in the tissue by combining experimental and computational biomechanics. The me...
Woodman MJ, Thomas MA, Colville MJ, Durgam S, McDonough SP, Reesink HL.To describe proteoglycan 4 (PRG4) expression, lubricin tissue distribution, and lubricin synovial fluid concentrations in healthy and injured equine flexor tendons and tenosynovial structures. Unassigned: Synovial fluid and tissues were collected over the span of 1 year. Proteoglycan 4 expression was quantified using quantitative real-time PCR, lubricin synovial fluid concentrations were measured using ELISAs, and lubricin tissue distribution was evaluated with immunohistochemistry. Histology and quantitative real-time PCR data for healthy samples were analyzed using paired t tests, repeated-m...
Lugo T, Myers S, Nguyen TA.In vitro models have revolutionized our understanding of biological pathways and mechanisms, offering a viable alternative to direct patient testing. However, there is a significant lack of models for different animals, particularly equine models. This study presents a novel primary cell culture extracted from a 3-year-old horse diagnosed with multisystemic eosinophilic epitheliotropic disease. Tissue samples were collected from lymph nodes at various locations. Growth curves of extracted primary cells were analyzed and the optimal conditions were assessed. Biomarkers, such as CD31, ZO-1, CD79...
Zhou Y, Yao X, Meng J, Wang J, Zeng Y, Li L, Ren W.The Kazakh horse is a highly valuable indigenous Chinese breed known for its use in both milk and meat production. However, the mechanisms underlying color variation in the abdominal adipose tissue of this breed remain poorly understood. In this study, the sequencing of non-coding RNAs (ncRNAs) was conducted on abdominal adipose tissue of different colors from Kazakh horses, with the aim of investigating the molecular mechanisms responsible for this variation. A total of 205 differentially expressed long non-coding RNAs (DELncRNAs) including , , and ; 52 differentially expressed microRNAs (DEm...
Robel M, Grest P, Riond B, Zablotski Y, Schoster A.Limited data are available on immune cells in the intestinal wall of healthy horses, hampering interpretation of results in case of disease. Objective: Characterize and quantify the immune cell populations and their distribution in duodenal and rectal biopsies of horses without gastrointestinal disease; compare immune cell counts (ICCTs) between full thickness- and mucosal biopsies. Methods: Twenty horses fit for slaughter, slaughtered for meat production. Methods: Full-thickness and endoscopic forceps obtained mucosal biopsies were taken within 30 min after slaughter from the duodenum and rec...
Guerri G, Bandera L, Straticò P, Palozzo A, Di Nunzio L, Celani G, Varasano V, Vignoli M, Petrizzi L.Superficial digital flexor tendon (SDFT) injuries cause progressive loss of its mechanical properties. Two-dimensional shear wave elastography (2D-SWE) provides information about tissue stiffness. Objective: To determine the feasibility, repeatability, and reproducibility of 2D-SWE of healthy and pathological forelimb SDFT. Methods: Prospective observational cohort study. Methods: Horses were divided into a noninjured Group (H) and a Group with tendinopathy of the SDFT (P). 2D-SWE of both fore SDFTs was performed at three metacarpal levels (A, B, and C, from proximal to distal). Qualitative an...
Cullen JN, Cieslak J, Petersen JL, Bellone RR, Finno CJ, Kalbfleisch TS, Calloe K, Capomaccio S, Cappelli K, Coleman SJ, Distl O, Durward-Akhurst SA....MicroRNAs (miRNAs) are essential regulators of gene expression, yet few comprehensive databases exist for miRNA expression in non-model species, limiting our ability to characterize their roles in gene regulation, development, and disease. Similarly, isomiRs - length and sequence isoforms of canonical miRNAs with potentially altered regulatory targets and functions - have received even less attention in non-model species, including the horse, leaving a critical gap in our understanding of their biological significance. To address these challenges, we developed an open-source, containerized pip...
Cequier A, Serrano MB, Soler-Monsó MT, Bernad E, Vázquez FJ, Vitoria A, Fuente S, Zaragoza P, Romero A, Rodellar C, Barrachina L.The allogeneic administration of equine mesenchymal stem/stromal cells (MSCs) has numerous advantages over autologous therapy, but their interactions with the patient's immune system need to be further elucidated. These interactions can be influenced by factors such as the compatibility between donor-receptor for the major histocompatibility complex (MHC) and by the MHC expression levels, which can change under different conditions like inflammatory exposure and chondrogeneic differentiation. In this study, we evaluated the local immune response induced by chondrogeneically differentiated (MSC...
Liu F, Zhang J, Kong L, Wu R, Jiang Q, Lu Y, Li X.As an interspecies hybrid inheriting genetic material from horse and donkey lineages, mules provide a unique model for studying allele-specific regulatory dynamics. Here, we isolated adult fibroblasts (AFs) and placental fibroblasts (PFs) from mule tissues and reprogrammed them into induced pluripotent stem cells (iPSCs). Intriguingly, placental fibroblast-derived iPSCs (mpiPSCs) exhibited reduced reprogramming efficiency compared to adult fibroblast-derived iPSCs (maiPSCs). Through allele-specific expression (ASE) analysis, we systematically dissected transcriptional biases in parental cell t...
Medina-Bolívar AL, Muñoz-Duque JD, Martínez-Aranzales JR.Information regarding Survivin protein expression in the gastric mucosa of equids is scarce. This protein has been associated with functions related to modulating apoptosis and promoting mitosis in epithelial cells and is considered part of gastric cytoprotection mechanisms in humans and mice, maintaining mucosal integrity and regulating cellular renewal. Objective: This study aimed to determine the expression of cytoplasmic and nuclear Survivin in gastric mucosae of equids (horses, donkeys, and mules). Methods: A total of 30 healthy stomachs, 10 from each species, were evaluated using histolo...
Tesena P, Vinijkumthorn R, Kingkaw A, Yanyongsirikarn P, Phasuk K, Ploypetch S, Phaonakrop N, Roytrakul S, Vongsangnak W, Prapaiwan N.Equine melanocytic neoplasm (EMN) is a skin tumor commonly observed in grey horses. Limited research has yet to investigate proteomic profiles of EMN, particularly in the early stages and their expression patterns. This study, therefore, aimed to identify signature proteins from tissue biopsies to distinguish early EMN, severe EMN, and normal groups. Results: Using proteomic analysis of 19 tissue samples (normal: n = 6, early EMN: n = 7, severe EMN: n = 6) through LC-MS/MS, 12,310 proteins were identified. Differentially expressed proteins (DEPs) and functional interaction analysi...
Scoggin KE, Adlan F, Fedorka CE, Rakha SI, Stout TAE, Troedsson MHT, Ali HE.The insulin-like growth factor (IGF) system regulates implantation, placental development, and angiogenesis in eutherian mammals. However, little is known about the changes in this system in equine placenta (chorioallantois; CA) and the endometrium (EN) during pregnancy, or the relationship to vascular endothelial growth factor () expression. The current study investigated the expression of the IGF system components, namely the ligands ( and ), their receptors (, , and ), and their binding proteins ( and s) in equine CA at 45 days, 4, 6, 10, and 11 months of gestational age (GA) and immediatel...
Böck MJ, Fernandez TJ, Pereira VP, da Veiga ML, de Mello Bertoncheli Dos Santos C, de Morais-Pinto L.We examined 52 horse aortas to characterize the morphological aspects of the aortic bulb wall and the ascending aorta. The morphometric data were analyzed using ImageJ®-Fiji 1.5 software. The Tunica intima was composed of endotheliocytes with scarce cytoplasm and ellipsoid nuclei, supported by a collagenous subendothelial stratum. The Tunica media was composed entirely of fascicles of vascular smooth muscle cells interspersed with bundles of collagen fibers and elastic lamellae, characterizing the aortic medial lamellar unit. The Tunica adventitia consisted of two distinct sub-layers: the ext...
Joostens Z, Audigié F, de la Rebière de Pouyade G, Garigliany MM, Busoni V.In human medicine, the enthesis, or tendon-to-bone insertion, is generally considered a linked entity or 'enthesis organ' and plays a crucial biomechanical role. This study aimed to histologically assess the equine proximal third interosseus muscle (suspensory ligament) enthesis in 10 pelvic limbs from 7 horses. The area of the proximal third interosseus muscle enthesis was divided into 6 compartments based on post-mortem computed tomography and prepared for histology using haematoxylin/eosin and trichrome staining. The proximal third interosseus muscle enthesis showed a fibrocartilaginous nat...
Durgam S.The mid-metacarpal SDFT, intrasynovial DDFT and suspensory ligament are frequently injured soft tissues in the equine athlete. The mid-metacarpal SDFT exhibits a hierarchical structure and encounters repetitive strains at its functional limit. The intrasynovial DDFT possesses fibrocartilage where opposing bony surfaces to facilitate resistance-free gliding and contains chondrocyte-like cells embedded in a proteoglycan-rich ECM. While suspensory ligament enthesis injuries are common, collagen and non-collagen ECM structure-function specializations at the bone-ligament interface are understudied...
Bertone AL, Reinemeyer C, Tsaprailis G, Ragland D, Leise B.The use of micro-particulate allografts is rising, but knowledge about the protein characterization and biocompatibility of umbilical cord-derived allografts (UC) in vivo is limited. Methods: Proteomic analyses using mass spectrometry (MS) determined equine UC protein relative quantification and functions using total spectral counts (TSC). UC cytokines were quantified by enzyme-linked immunosorbent assay (ELISA). Three in vivo studies assessed recipient clinical and tissue biocompatibility in joints and ligaments. Results: Proteomics revealed 2645 annotated TSCs. Proteins of > 89 TSC we...
Mohamed E, Van Cleemput J, Şahin B, Van den Broeck W, Boyen F, Nauwynck H.The equine respiratory and reproductive tract microbiomes are complex and subject to constant fluctuations. Among the microbial inhabitants, subsp. (SEZ) is recognized as the dominant bacterium. It is an opportunistic pathogen that may occasionally lead to various types of infections. A key virulence factor of SEZ is the streptolysin S (SLS) toxin, which is responsible for the characteristic β-hemolysis on blood agar and tissue damage. Viruses and bacteria may interact and aggravate lesions and disease. This study aimed to evaluate the impact of an SLS-containing supernatant from SEZ on the...
Ząbek T, Witarski W, Szmatoła T, Semik-Gurgul E, Sawicki S, Ropka-Molik K.We have explored the impact of DNA methylation changes on gene transcription in expanded equine chondrocytes treated with the histone deacetylase inhibitor (HDACi), Trichostatin A (TSA). The subjects were DNA and RNA samples prepared from articular cartilage cells derived from four animals in our previous study. Using Reduced Representation Bisulfite Sequencing (RRBS), we determined differentially methylated sites (DMS) and regions (DMRs) in the genomes of TSA-treated cells. We linked them to gene differential expression, as obtained from 3' mRNA sequencing data and the single-locus quantifica...
Abrahams M.The mechanical behaviour of horse and human tendon, as characterised by the stress-strain curve, has been examined with respect to load-strain cycling and strain rate. It was found that the tendon stress-strain curve for successive cycles was reporducible provided that strain on the specimen did not exceed 2·0–4·0%. If this strain level was exceeded, a permanent deformation occurred. This phenomenon was verified by histological studies on strained tendon which showed that some of the collagen fibres did not return to their original orientation. Variation in the rate of strain was found to ...
Hidaka C, Goodrich LR, Chen CT, Warren RF, Crystal RG, Nixon AJ.Cartilage has a limited capacity to heal. Although chondrocyte transplantation is a useful therapeutic strategy, the repair process can be lengthy. Previously we have shown that over expression of bone morphogenetic protein-7 (BMP-7) in chondrocytes by adenovirus-mediated gene transfer leads to increased matrix synthesis and cartilage-like tissue formation in vitro. In this context we hypothesized that implantation of genetically modified chondrocytes expressing BMP-7 would accelerate the formation of hyaline-like repair tissue in an equine model of cartilage defect repair. Methods: Chondrocyt...
Koch TG, Berg LC, Betts DH.This paper provides a bird's-eye perspective of the general principles of stem-cell therapy and tissue engineering; it relates comparative knowledge in this area to the current and future status of equine regenerative medicine.The understanding of equine stem cell biology, biofactors, and scaffolds, and their potential therapeutic use in horses are rudimentary at present. Mesenchymal stem cell isolation has been proclaimed from several equine tissues in the past few years. Based on the criteria of the International Society for Cellular Therapy, most of these cells are more correctly referred t...
Hoffmann C, Ellenberger C, Mattos RC, Aupperle H, Dhein S, Stief B, Schoon HA.This paper describes the histomorphological and immunohistochemical characterisation of phenotypic variations of endometrosis as well as potential etiological factors which may influence disease progression. In total, 779 endometrial biopsies were examined. These biopsies were taken in the breeding and non-breeding season (n=509), on defined days during the estrous cycle (n=70) and before and after experimentally induced bacterial endometritis (n=200). In addition to conventional histopathology, selected biopsies were investigated using alcianblue staining as well as immunohistochemical method...
Visser J, Levett PA, te Moller NC, Besems J, Boere KW, van Rijen MH, de Grauw JC, Dhert WJ, van Weeren PR, Malda J.Decellularized tissues have proven to be versatile matrices for the engineering of tissues and organs. These matrices usually consist of collagens, matrix-specific proteins, and a set of largely undefined growth factors and signaling molecules. Although several decellularized tissues have found their way to clinical applications, their use in the engineering of cartilage tissue has only been explored to a limited extent. We set out to generate hydrogels from several tissue-derived matrices, as hydrogels are the current preferred cell carriers for cartilage repair. Equine cartilage, meniscus, a...
Williams IF, McCullagh KG, Silver IA.During tissue response to injury the glycoproteins fibronectin and Type III collagen are synthesized in increased amounts. We have studied the distribution of these molecules in the healing tendon at various times after injury by comparison with that of the major constituent of normal tendon, Type I collagen. Immunofluorescent localization demonstrated the presence of fibronectin throughout the tendon within one week after injury. Staining was found in the matrix, both around capillaries and around fibroblast-like cells. Fibronectin was still apparent in the healing tendon at one month after i...
Sellon DC, Perry ST, Coggins L, Fuller FJ.In situ hybridization of tissues from two horses infected with the wild-type Wyoming strain of equine infectious anemia virus (EIAV) identified the liver, spleen, lymph nodes, kidney, lung, and adrenal gland as the primary host tissue sites for viral transcription during acute infection. Combined immunohistochemistry, with a monoclonal antibody recognizing a cytoplasmic antigen of equine mononuclear phagocytes, and in situ hybridization for viral RNA identified most infected cells as mature tissue macrophages. In contrast, in situ hybridization of adherent peripheral blood mononuclear cells co...
Hoynowski SM, Fry MM, Gardner BM, Leming MT, Tucker JR, Black L, Sand T, Mitchell KE.Stem cells are being evaluated in numerous human clinical trials and are commercially used in veterinary medicine to treat horses and dogs. Stem cell differentiation, homing to disease sites, growth and cytokine factor modulation, and low antigenicity contribute to their therapeutic success. Bone marrow and adipose tissue are the two most common sources of adult-derived stem cells in animals. We report on the existence of an alternative source of primitive, multipotent stem cells from the equine umbilical cord cellular matrix (Wharton's jelly). Equine umbilical cord matrix (EUCM) cells can be ...
da Silva Meirelles L, Sand TT, Harman RJ, Lennon DP, Caplan AI.Mesenchymal stem cells (MSCs) are multipotent cells that have the capacity to develop into different mature mesenchymal cell types. They were originally isolated from bone marrow, but MSC-like cells have also been isolated from other tissues. The common feature of all of these tissues is that they all house blood vessels. It is, thus, possible that MSCs are associated with perivascular locations. The objective of this work was to test the hypothesis that MSCs are associated with blood vessels by verifying if MSC frequency positively correlates with blood vessel density. To this end, samples fr...
Crovace A, Lacitignola L, Rossi G, Francioso E.The aim of this study was to compare treatment with cultured bone marrow stromal cells (cBMSCs), bone marrow Mononucleated Cells (BMMNCs), and placebo to repair collagenase-induced tendinitis in horses. In six adult Standardbred horses, 4000 IU of collagenase were injected in the superficial digital flexor tendon (SDFT). Three weeks after collagenase treatment, an average of either 5.5 x 10(6) cBMSCs or 1.2 x 10(8) BMMNCs, fibrin glue, and saline solution was injected intralesionally in random order. In cBMSC- and BMMNCS-treated tendons, a high expression of cartilage oligomeric matrix protein...
Birch HL, Bailey AJ, Goodship AE.Injuries to the superficial digital flexor tendon are common in horses required to gallop and jump at speed. Partial rupture of this tendon usually occurs in the central core of the midmetacarpal region and may be preceded by localised degenerative changes. Post mortem examination of apparently normal equine flexor tendons has revealed an abnormal macroscopic appearance in the central core, characterised by a reddish discolouration. We have previously shown that there is also physical damage to the collagen fibres. In the present study we tested the hypothesis that the abnormal appearance is a...
Rathi R, Honaramooz A, Zeng W, Turner R, Dobrinski I.Grafting of testis tissue from immature animals to immunodeficient mice results in complete spermatogenesis, albeit with varying efficiency in different species. The objectives of this study were to investigate if grafting of horse testis tissue would result in spermatogenesis, and to assess the effect of exogenous gonadotropins on xenograft development. Small fragments of testis tissue from 7 colts (2 week to 4 years of age) were grafted under the back skin of castrated male immunodeficient mice. For 2 donor animals, half of the mice were treated with gonadotropins. Xenografts were analyzed a...
Morisset S, Frisbie DD, Robbins PD, Nixon AJ, McIlwraith CW.Repair of cartilage defects involves sequential participation of specific hormones and growth factors with potential impairment by inflammatory cytokines. We explored an in vivo gene therapy treatment to supply adenoviral vectors carrying the genes of interleukin-1 receptor antagonist protein (IL-1ra) and insulinlike growth factor-1 (IGF-1), hoping to enhance repair of full-thickness equine chondral defects treated with microfracture. We asked whether our treatment could (1) increase proteoglycan and Type II collagen content in the repair tissue, (2) improve the macroscopic and histomorphometr...
Watts AE, Millar NL, Platt J, Kitson SM, Akbar M, Rech R, Griffin J, Pool R, Hughes T, McInnes IB, Gilchrist DS.Tendon injuries (tendinopathies) are common in human and equine athletes and characterized by dysregulated collagen matrix, resulting in tendon damage. We have previously demonstrated a functional role for microRNA29a (miR29a) as a post-transcriptional regulator of collagen 3 expression in murine and human tendon injury. Given the translational potential, we designed a randomized, blinded trial to evaluate the potential of a miR29a replacement therapy as a therapeutic option to treat tendinopathy in an equine model that closely mimics human disease. Tendon injury was induced in the superficial...
Stewart MC, Stewart AA.This article provides an overview of mesenchymal stem cell (MSC) biology. In the first section, the characteristics that are routinely used to define MSCs-adherence, proliferation, multi-lineage potential, and "cluster of differentiation" marker profiles-are discussed. In the second section, the major tissues and body fluids that are used as sources for equine MSCs are presented, along with the comparative biologic activities of MSCs from specific locations. Finally, the current understanding of the mechanisms by which MSCs influence repair and regeneration are discussed, with an emphasis on t...
Mocchi M, Dotti S, Bue MD, Villa R, Bari E, Perteghella S, Torre ML, Grolli S.Regenerative medicine aims to restore the normal function of diseased or damaged cells, tissues, and organs using a set of different approaches, including cell-based therapies. In the veterinary field, regenerative medicine is strongly related to the use of mesenchymal stromal cells (MSCs), which belong to the body repair system and are defined as multipotent progenitor cells, able to self-replicate and to differentiate into different cell types. This review aims to take stock of what is known about the MSCs and their use in the veterinary medicine focusing on clinical reports on dogs and hors...
Szóstek-Mioduchowska AZ, Lukasik K, Skarzynski DJ, Okuda K.Transforming growth factor (TGF)-β1 not only regulates cell growth, development, and tissue remodeling, but it also participates in the pathogenesis of tissue fibrosis. In the equine endometrium, the concentration of TGF-β1 is correlated with endometrosis (equine endometrial fibrosis). In other tissues, TGF-β1 induces differentiation of many cell types into myofibroblasts. These cells are characterized by α-smooth muscle actin (α-SMA) expression and an ability to deposit excessive amounts of extracellular matrix (ECM) components. The aim of the study was to determine whether TGF-β1 plays...
Lange-Consiglio A, Perrini C, Tasquier R, Deregibus MC, Camussi G, Pascucci L, Marini MG, Corradetti B, Bizzaro D, De Vita B, Romele P, Parolini O....Administration of horse amniotic mesenchymal cells (AMCs) and their conditioned medium (AMC-CM) improves the in vivo recovery of spontaneous equine tendon lesions and inhibits in vitro proliferation of peripheral blood mononuclear cells (PBMC). This process may involve microvesicles (MVs) as an integral component of cell-to-cell communication during tissue regeneration. In this study, the presence and type of MVs secreted by AMCs were investigated and the response of equine tendon cells to MVs was studied using a dose-response curve at different concentrations and times. Moreover, the ability ...
Youngstrom DW, LaDow JE, Barrett JG.Tendons are frequently damaged and fail to regenerate, leading to pain, loss of function, and reduced quality of life. Mesenchymal stem cells (MSCs) possess clinically useful tissue-regenerative properties and have been exploited for use in tendon tissue engineering and cell therapy. However, MSCs exhibit phenotypic heterogeneity based on the donor tissue used, and the efficacy of cell-based treatment modalities may be improved by optimizing cell source based on relative differentiation capacity. Equine MSCs were isolated from bone marrow (BM), adipose (AD), and tendon (TN), expanded in monola...
Barsby T, Bavin EP, Guest DJ.The natural reparative mechanisms triggered by tendon damage often lead to the formation of biomechanically inferior scar tissue that is prone to re-injury. Before the efficient application of stem cell-based regenerative therapies, the processes regulating tenocyte differentiation should first be better understood. Three-dimensional (3D) growth environments under strain and the exogenous addition of transforming growth factor beta3 (TGF-β3) have separately been shown to promote tendon differentiation. The aim of this study was to determine the ability of both of these factors to induce tendo...
Arun SS, Breuer W, Hermanns W.Five species of domestic animals were examined immunohistochemically and the light-chain ratios of the immunoglobulins produced by plasma cells analysed. Forty dogs, 11 cats, 10 horses, 11 cattle and 14 pigs were tested using the sequential indirect immunoperoxidase and immunophosphatase methods. Tissues from the tonsils, spleen and cervical lymph nodes were analysed. It could be seen that the lambda/kappa ratio in dogs, cats, horses and cattle is largely dominated by the lambda chains (lambda/kappa ratio in dogs: 91/9%, in cats; 92/8%; in horses: 96/4%; in cattle: 91/9%). A more or less balan...
Raabe O, Reich C, Wenisch S, Hild A, Burg-Roderfeld M, Siebert HC, Arnhold S.Adipose-derived stromal cells (ADSCs) are multipotent cells which, in the presence of appropriate stimuli, can differentiate into various lineages such as the osteogenic, adipogenic and chondrogenic. In this study, we investigated the effect of transforming growth factor beta 1 (TGF-β1) in comparison to hydrolyzed fish collagen in terms of the chondrogenic differentiation potential of ADSCs. ADSCs were isolated from subcutaneous fat of horses by liposuction. Chondrogenesis was investigated using a pellet culture system. The differentiation medium was either supplemented with TGF-β1 (5 ng/ml)...
Roth SP, Glauche SM, Plenge A, Erbe I, Heller S, Burk J.Decellularization of tendon tissue plays a pivotal role in current tissue engineering approaches for in vitro research as well as for translation of graft-based tendon restoration into clinics. Automation of essential decellularization steps like freeze-thawing is crucial for the development of more standardized decellularization protocols and commercial graft production under good manufacturing practice (GMP) conditions in the future. In this study, a liquid nitrogen-based controlled rate freezer was utilized for automation of repeated freeze-thawing for decellularization of equine superficia...
Harrold SM, Cook SJ, Cook RF, Rushlow KE, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV) infection of horses is characterized by recurring cycles of disease and viremia that typically progress to an inapparent infection in which clinical symptoms are absent as host immune responses maintain control of virus replication indefinitely. The dynamics of EIAV viremia and its association with disease cycles have been well characterized, but there has been to date no comprehensive quantitative analyses of the specific tissue sites of EIAV infection and replication in experimentally infected equids during acute disease episodes and during asymptomatic ...
Kon E, Muttini A, Arcangeli E, Delcogliano M, Filardo G, Nicoli Aldini N, Pressato D, Quarto R, Zaffagnini S, Marcacci M.The present in vivo preliminary experiment is aimed at testing mechanical and biological behaviour of a new nano-structured composite multilayer biomimetic scaffold for the treatment of chondral and osteochondral defects. The three-dimensional biomimetic scaffold (Fin-Ceramica Faenza S.p.A., Faenza-Italy) was obtained by nucleating collagen fibrils with hydroxyapatite nanoparticles, in two configurations, bi- and tri-layered, to reproduce, respectively, chondral and osteochondral anatomy. Chondral defects (lateral condyle) and deep osteochondral defects (medial condyle) were made in the distal...
Bussche L, Harman RM, Syracuse BA, Plante EL, Lu YC, Curtis TM, Ma M, Van de Walle GR.The prevalence of impaired cutaneous wound healing is high and treatment is difficult and often ineffective, leading to negative social and economic impacts for our society. Innovative treatments to improve cutaneous wound healing by promoting complete tissue regeneration are therefore urgently needed. Mesenchymal stromal cells (MSCs) have been reported to provide paracrine signals that promote wound healing, but (i) how they exert their effects on target cells is unclear and (ii) a suitable delivery system to supply these MSC-derived secreted factors in a controlled and safe way is unavailabl...
Youngstrom DW, Barrett JG, Jose RR, Kaplan DL.Natural extracellular matrix provides a number of distinct advantages for engineering replacement orthopedic tissue due to its intrinsic functional properties. The goal of this study was to optimize a biologically derived scaffold for tendon tissue engineering using equine flexor digitorum superficialis tendons. We investigated changes in scaffold composition and ultrastructure in response to several mechanical, detergent and enzymatic decellularization protocols using microscopic techniques and a panel of biochemical assays to evaluate total protein, collagen, glycosaminoglycan, and deoxyribo...
Reilly GC, Currey JD.During locomotion, the anterior cortex of the equine radius is loaded predominantly in tension, the posterior predominantly in compression. The anterior cortex is relatively strong in tension, the posterior in compression. We investigated the pattern of failure of specimens from the two cortices using laser scanning confocal microscopy. All specimens were loaded in four-point bending to increasingly higher loads. We quantified the amount of diffuse microcracking on the tensile side of these specimens by observing the amount of light emitted under laser illumination. The amount of light emitted...
Stewart AA, Byron CR, Pondenis H, Stewart MC.To determine whether fibroblast growth factor-2 (FGF-2) treatment of equine mesenchymal stem cells (MSCs) during monolayer expansion enhances subsequent chondrogenesis in a 3-dimensional culture system. Methods: 6 healthy horses, 6 months to 5 years of age. Methods: Bone marrow-derived MSCs were obtained from 6 horses. First-passage MSCs were seeded as monolayers at 10,000 cells/cm(2) and in medium containing 0, 1, 10, or 100 ng of FGF-2/mL. After 6 days, MSCs were transferred to pellet cultures (200,000 cells/pellet) and maintained in chondrogenic medium. Pellets were collected after 15 days....
Radtke CL, Nino-Fong R, Esparza Gonzalez BP, Stryhn H, McD￮ LA.To characterize equine muscle tissue- and periosteal tissue-derived cells as mesenchymal stem cells (MSCs) and assess their proliferation capacity and osteogenic potential in comparison with bone marrow- and adipose tissue-derived MSCs. Methods: Tissues from 10 equine cadavers. Methods: Cells were isolated from left semitendinosus muscle tissue, periosteal tissue from the distomedial aspect of the right tibia, bone marrow aspirates from the fourth and fifth sternebrae, and adipose tissue from the left subcutaneous region. Mesenchymal stem cells were characterized on the basis of morphology, ad...
