Aggregation in horses refers to the behavior of horses forming groups or herds, which is a natural social structure for these animals. This behavior is influenced by various factors, including environmental conditions, social dynamics, and individual horse characteristics. Aggregation can impact resource allocation, predator avoidance, and social interactions within the group. Research on equine aggregation examines the patterns and drivers of group formation, as well as the implications for horse welfare and management. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, benefits, and challenges associated with aggregation behavior in horses.
Miglio A, Falcinelli E, Cappelli K, Mecocci S, Mezzasoma AM, Antognoni MT, Gresele P.Training has a significant effect on the physiology of blood coagulation in humans and in horses. Several hemostatic changes have been reported after exercise in the horse but data available are inconclusive. The aim of this study was to investigate platelet activation and primary platelet-related hemostasis modifications in young never-trained Thoroughbreds in the first incremental training period in order to improve knowledge on this topic. Twenty-nine clinically healthy, untrained, 2-year-old Thoroughbred racehorses were followed during their incremental 4-month sprint exercise training. Bl...
Silva JA, Castañares M, Mouguelar H, Valenciano JA, Pellegrino MS.Endometritis, the inflammation of the endometrium, is the leading cause of subfertility in mares, and therefore responsible for major economic losses in the horse industry worldwide. It is generally treated with uterine lavages combined with ecbolic agents and local or systemic antibiotics. However, since antibiotic overuse has been associated with antimicrobial resistance in mares with persistent endometritis, new prevention and treatment alternatives are needed. One such alternative could be the use of probiotic lactic acid bacteria (LAB) isolated from the host. Thanks to their species speci...
Sola D, Artigas R, Mediano DR, Zaragoza P, Badiola JJ, Martín-Burriel I, Acín C.Prion diseases are fatal neurodegenerative disorders in which the main pathogenic event is the conversion of the cellular prion protein (PrP) into an abnormal and misfolded isoform known as PrP. Most prion diseases and their susceptibility and pathogenesis are mainly modulated by the PRNP gene that codes for PrP. Mutations and polymorphisms in the PRNP gene can alter PrP amino acid sequence, leading to a change in transmission efficiency depending on the place where it occurs. Horses are animals that are considered to be highly resistant to prions. Several studies have attempted to identify po...
Basso RM, Andrade DGA, Alves CEF, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Dwarfism is a skeletal disorder that causes abnormal growth. In Miniature horses, dwarfism can occur as chondrodysplastic dwarfism, an autosomal recessive disorder associated with five mutations (D1, D2, D3*, D4 and c.6465A > T variant) in the aggrecan (ACAN) gene. The aim of this study was to evaluate the expression of aggrecan (at the gene and protein level) and specific cytokines (IL-1β, IL-6, and TNF-α) in the articular cartilage of Miniature horses with chondrodysplastic dwarfism (D4/c.6465A > T genotype). Metatarsal bone samples from eight dwarf Miniature horses were collected fo...
Bourebaba L, Michalak I, Baouche M, Kucharczyk K, Marycz K.Chondrogenesis represents a highly dynamic cellular process that leads to the establishment of various types of cartilage. However, when stress-related injuries occur, a rapid and efficient regeneration of the tissues is necessary to maintain cartilage integrity. Mesenchymal stem cells (MSCs) are known to exhibit high capacity for self-renewal and pluripotency effects, and thus play a pivotal role in the repair and regeneration of damaged cartilage. On the other hand, the influence of certain pathological conditions such as metabolic disorders on MSCs can seriously impair their regenerative pr...
Golonka P, Szklarz M, Kusz M, Marędziak M, Irwin Houston JM, Marycz K.One of the most common reasons for horse lameness is subchondral bone cysts (SBCs), which are especially evident in young horse athletes. It is believed that SBC development is strongly associated with an individual's bone growth and/or bone microstructure impairment. Current methods of SBC treatment include pharmacological treatment or surgical procedures which may allow the bone within the cyst to rebuild and be restored to properly developed bone tissue. Thus, we propose filling the SBCs with a 3D complex of alginate hydrogel and autologous adipose derived mesenchymal stem cells (ASCs). We ...
De Angelis E, Ravanetti F, Martelli P, Cacchioli A, Ivanovska A, Corradi A, Nasi S, Bianchera A, Passeri B, Canelli E, Bettini R, Borghetti P.The present study investigated the biocompatibility of chitosan films and scaffolds modified with d-(+)raffinose and their capability to support the growth and maintenance of the differentiation of articular chondrocytes in vitro. Primary equine articular chondrocytes were cultured on films and scaffolds of modified d-(+) raffinose chitosan. Their behavior was compared to that of chondrocytes grown in conventional bi- and three-dimensional culture systems, such as micromasses and alginate beads. Chitosan films maintained the phenotype of differentiated chondrocytes (typical round morphology) a...
Roscher KA, Failing K, Schenk I, Moritz A.The reasons for this prospective experimental study were to determine a dosing scheme with loading and maintenance dose of aspirin inducing inhibition of platelet function measured by whole blood impedance aggregometry. Ten horses received aspirin orally in the morning with one loading dose of 4.7-5 mg/kg and maintenance doses of 1-1.3 mg/kg daily the following 4 days. Aggregometries (COLtest, ASPItest, ADPtest) and serum salicylic acid were measured. ASPItest showed significant difference in inhibition at 24 and 48 hr (p < .05) and 96 hr (p < .01). Significant change for ADPtes...
Rotkina AS, Pronina IV, Lazarev VN, Akhaev DN, Baskova IP.The purpose. Identifying the capacity of the medicinal leech novel original recombinant thrombolytic preparation Destabilase-Lysozyme-2 to inhibit the blood platelet aggregation. Gene of destabilase-lysozyme. ds2 (mlDL-Ds2 ), was cloned in E.coli cells. Recombinant protein was isolated in denaturing conditions using metal-chelate chromatography followed by denaturation of the polypeptide by rapid dilution in exact accordance with the procedure described by Kurdyumov A.S. et al. ( 2016, Russian Journal of Bioorganic Chemistry, v.42, s. 42-52). Blood was collected from the jugular vein of 18 hor...
Zayed MN, Schumacher J, Misk N, Dhar MS.Mesenchymal stromal cells (MSCs) have the capacity to differentiate into cells of mesenchymal lineage, such as chondrocytes, and have potential for use in regeneration of equine articular cartilage. MSCs instilled intra-articularly would be exposed to the inflamed environment associated with equine osteoarthritis (OA), which may compromise their function and ability to heal a cartilaginous defect. The aim of this study was to assess the ability of equine adult MSCs to differentiate into chondrocytes when stimulated with pro-inflammatory cytokines. MSCs derived from equine bone marrow (BM) and ...
Griffin DJ, Ortved KF, Nixon AJ, Bonassar LJ.Several studies have demonstrated the benefits of IGF-I gene therapy in enhancing the histologic and biochemical content of cartilage repaired by chondrocyte transplantation. However, there is little to no data on the mechanical performance of IGF-I augmented cartilage grafts. This study evaluated the compressive properties of full-thickness chondral defects in the equine femur repaired with and without IGF-I gene therapy. Animals were randomly assigned to one of three study cohorts based on chondrocyte treatment provided in each defect: (i) IGF-I gene delivered by recombinant adeno-associated...
Henderson SE, Santangelo KS, Bertone AL.To determine effects of various concentrations of retinoic acid (RA) or a synthetic RA receptor antagonist (LE135) on equine chondrocytes or bone marrow-derived equine mesenchymal stem cells (BMDMSCs) in monolayer cultures. Methods: Articular cartilage and BMDMSCs from 5 clinically normal horses. Methods: Monolayers of chondrocytes cultured in standard media and of BMDMSCs cultured in chondrogenic media were treated with RA at concentrations of 0, 0.1, 1, or 10 μM or LE135 at concentrations of 0, 0.1, 1, or 10 μM on day 0. On days 7 and 14, samples were analyzed for DNA concentration, chondr...
Frisbie DD, Mc Ilwraith CW, Arthur RM, Blea J, Baker VA, Billinghurst RC.Biomarkers have shown some in vivo promise for the detection of musculoskeletal injuries, but further study to assess biomarker levels in clinical orthopaedic disease is required. Objective: To assess 7 serum biomarkers for the detection of musculoskeletal injuries. Methods: Two- and 3-year-old racehorses were entered into the study (n = 238). Exit criteria were lack of training for >30 days, or completion of 10 study months. Data from horses with solitary musculoskeletal injuries and completion of >2 months were analysed. Musculoskeletal injury was considered intra-articular fragmentation (IA...
Peffers MJ, Milner PI, Tew SR, Clegg PD.SOX9 is a transcription factor that is essential for cartilage extracellular matrix (ECM) formation. Osteoarthritis (OA) is characterised by a loss of cartilage ECM. In chondrocytes SOX9 gene expression is regulated by osmotic loading. Here we characterise SOX9 mRNA regulation through static and cyclical application of hyperosmotic conditions in normal and OA monolayer equine chondrocytes. Furthermore, we investigate whether extracellular signal-regulated protein kinase (ERK)1/2 mitogen-activated protein kinases (MAPK) pathways have a role in this regulation of SOX9. Methods: Equine chondrocyt...
Stewart AA, Byron CR, Pondenis HC, Stewart MC.To determine whether expansion of equine mesenchymal stem cells (MSCs) by use of fibroblast growth factor-2 (FGF-2) prior to supplementation with dexamethasone during the chondrogenic pellet culture phase would increase chondrocytic matrix markers without stimulating a hypertrophic chondrocytic phenotype. Methods: MSCs obtained from 5 young horses. Methods: First-passage equine monolayer MSCs were supplemented with medium containing FGF-2 (0 or 100 ng/mL). Confluent MSCs were transferred to pellet cultures and maintained in chondrogenic medium containing 0 or 10(7)M dexamethasone. Pellets were...
Spengler MI, Bertoluzzo SM, Catalani G, Rasia ML.The aim of the present paper is to analyze whether membrane fluidity can be predicted from its lipid composition and to assay the possible relationship between such variable and the aggregating properties of erythrocytes from equine, bovine and human species due to the widely acknowledged differences in their tendency to form aggregates. The main difference between phospholipids from plasma membrane in these species lies in the concentration levels of sphyngomyelin (SM) and phosphatidilcoline (PC); more precisely, in the external hemilayer of the lipid bilayer. Membrane fluidity was estimated ...
Fradette ME, Céleste C, Richard H, Beauchamp G, Laverty S.To evaluate the effects of continuous oral administration of phenylbutazone on serum and synovial fluid biomarkers of skeletal matrix metabolism in horses. Methods: 11 adult female horses without clinical or radiographic evidence of joint disease. Methods: Horses were randomly assigned to control or treatment groups. Phenylbutazone was administered orally twice daily at a dose of 4.4 mg/kg for 3 days to the treatment group and subsequently at a dose of 2.2 mg/kg for 7 days. Serum and radiocarpal synovial fluid samples were obtained at baseline and thereafter at regular intervals for 4 weeks. B...
Uthamanthil RK, Edwards RB, Lu Y, Manley PA, Athanasiou KA, Markel MD.Chondromalacia can cause joint pain and synovial effusion with the potential for developing into osteoarthritis. Thermal chondroplasty using radiofrequency energy (RFE) has been reported to be superior to mechanical debridement for treating chondromalacia. We compared short-term changes in biomechanical properties of articular cartilage after treatment with monopolar (mRFE) or bipolar RFE (bRFE) or mechanical debridement (MD) on experimentally created grade II chondromalacia patellae. Chondromalacia patellae was created arthroscopically in both patellae of 15 ponies. Ten months after surgery, ...
Neil KM, Orth MW, Coussens PM, Chan PS, Caron JP.To determine whether glucosamine and chondroitin sulfate (CS) at concentrations approximating those achieved in plasma by oral administration would influence gene expression of selected mediators of osteoarthritis in cytokine-stimulated equine articular chondrocytes. Methods: Samples of grossly normal articular cartilage obtained from the metacarpophalangeal joint of 13 horses. Methods: Equine chondrocytes in pellet culture were stimulated with a subsaturating dose of recombinant equine interleukin (reIL)-1beta. Effects of prior incubation with glucosamine (2.5 to 10.0 microg/mL) and CS (5.0 t...
Frisbie DD, Oxford JT, Southwood L, Trotter GW, Rodkey WG, Steadman JR, Goodnight JL, McIlwraith CW.The current study investigated healing of large full-thickness articular cartilage defects during the first 8 weeks with and without penetration of the subchondral bone using microfracture in an established equine model of cartilage healing. Chondral defects in the weightbearing portion of the medial femoral condyle were made bilaterally; one defect in each horse was microfractured whereas the contralateral leg served as the control. The expression of cartilage extracellular matrix components (Types I and II collagen and aggrecan) was evaluated using histologic techniques, reverse transcriptio...
Mateos-Trigos G, Evans RJ, Heath MF.Horses show susceptibility to platelet-related disorders. Equine platelets differ from human platelets in some of their responses, so information available about human platelets must be validated in the horse. Aggregation of platelets by ADP involves both P2Y(1) and P2Y(12) receptors on the platelet surface. We have compared the effect of the P2Y(12) antagonist, AR-C67085, on equine and human platelets in vitro using turbidimetric aggregometry to measure the rate and final extent of aggregation. Aggregation profiles, concentration-response curves and pA(2) values show that the rate of aggregat...
Mateos-Trigos G, Evans RJ, Heath MF.Platelet activation by adenosine 5' -diphosphate (ADP) is via both P2Y(1 )and P2Y(12) receptors and leads to shape change and aggregation. The effects on ADP-induced platelet shape change of two P2Y(1) antagonists, adenosine 3'-phosphate, 5'-phosphosulfate (A3P5PS) and 2-deoxy-N(6)-methyladenosine 3', 5'-diphosphate (MRS-2179) and a P2Y(12) antagonist 2-propylthio-D-beta,gamma-dichloromethylene-adenosine 5'-triphosphate (AR-C67085MX) were determined by turbidimetric aggregometry and scanning electron microscopy (SEM) on equine and human platelets. The platelet aggregation was inhibited during ...
Jarvis GE, Atkinson BT, Snell DC, Watson SP.1. Various platelet membrane glycoproteins have been proposed as receptors for collagen, in some cases as receptors for specific collagen types. In this study we have compared the ability of a range of collagen types to activate platelets. 2. Bovine collagen types I-V, native equine tendon collagen fibrils and collagen-related peptide (CRP) all induced platelet aggregation and shape change. 3. Responses were abolished in FcRgamma chain-deficient platelets, which also lack GPVI, indicating a critical dependence on the GPVI/FcRgamma chain complex. 4. Responses to all collagens were unaffected in...
Spengler MI, Rasia M.The aggregation capacity of human erythrocytes lies between that of the non-aggregating bovine erythrocytes and the remarkably aggregating equine ones. As the ability to aggregate is attributed to cell factors and the composition of the plasma proteins, the role that plasma proteins play in the aggregation process in these three species was studied. Washed erythrocytes were suspended in phosphate-buffered saline (PBS; pH 7.4, 300 mOsm/L) plus polyvinylpyrrolidone (PVP) in a suitable concentration to obtain an average intensity of aggregation (control media). The superimposed effect of replacin...
Fortier LA, Balkman CE, Sandell LJ, Ratcliffe A, Nixon AJ.This study evaluated the constitutive insulin-like growth factor-I (IGF-I) gene expression pattern in spontaneously healing cartilage defects over the course of 16 weeks, and correlated the tissue morphology and matrix gene expression with IGF-I mRNA levels. Full-thickness 15 mm cartilage defects were debrided in the femoral trochlea of both femoropatellar joints of 8 horses and the healing defects examined 2, 4, 8, or 16 weeks after surgery. Samples were harvested for histologic assessment of tissue healing using H&E staining, toluidine blue histochemical reaction for proteoglycan deposition,...
Baskurt OK, Bor-Kucukatay M, Yalcin O, Meiselman HJ.Differences of red blood cell (RBC) aggregation among various mammalian species has been previously reported for whole blood, for RBC in autologous plasma, and for washed RBC re-suspended in polymer solutions. The latter observation implies the role of cellular factors, yet comparative studies of such factors are relatively limited. The present study thus investigated RBC aggregation and RBC electrophoretic mobility (EPM) for guinea pigs, rabbits, rats, humans and horses; RBC were re-suspended in isotonic 500 kDa dextran solutions for the EPM and aggregation measurements, with aggregation stud...
Ramirez S, Gaunt SD, McClure JJ, Oliver J.Horse mares carrying mule foals were immunized during the last trimester of pregnancy with whole acid-citrate-dextrose-anticoagulated donkey blood to experimentally induce neonatal alloimmune thrombocytopenia. Thrombocytopenia occurred in the neonatal mule foals born to immunized horse mares within 24 hours after ingestion of their dams' colostrum. Mule foals born to mares not immunized with donkey blood did not develop thrombocytopenia. These findings suggest that antibodies may have been directed against a donkey platelet antigen present in the mule foals but not present in their dams. The o...
MacLeod JN, Fubini SL, Gu DN, Tetreault JW, Todhunter RJ.To determine whether steady-state levels of type-II procollagen, aggrecan core protein, or fibronectin mRNA in articular chondrocytes are altered by synovitis or administration of methylprednisolone acetate (MPA). Methods: Articular cartilage specimens collected from 10 ponies, 2.5 to 3.5 years old and 200 to 300 kg. Methods: 4 experimental groups were compared, using the cartilage specimens: control, MPA-treated, lipopolysaccharide-induced synovitis, and lipopolysaccharide-induced synovitis with MPA treatment. RNA was isolated from articular cartilage and compared by northern blot analysis, u...
Weiss DJ, Evanson OA, McClenahan D, Fagliari JJ, Jenkins K.To determine whether platelets are hyperaggregable or form platelet-neutrophil aggregates during the prodromal stages of acute laminitis of ponies. Methods: Healthy adult ponies: 8 experimental and 6 control. Methods: Acute laminitis was induced by oral administration of corn starch and wood flour to 8 ponies, and indices of platelet activation were evaluated. Blood samples were collected before and at 4, 8, 12, 24, 28, and 32 hours after carbohydrate administration, and PCV, total plasma protein concentration, platelet count, activated clotting time, whole blood recalcification time, spontane...
Jarvis GE, Evans RJ, Heath MF.We have shown previously that endotoxin induces platelet aggregation in equine heparinised whole blood in a platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) dependent manner. ADP is an agonist of platelets and is present in platelet dense granules with ATP in high concentrations. An investigation was carried out to establish whether endotoxin-induced platelet activation was associated with release of platelet ATP and ADP. ADP-scavenging enzyme systems significantly inhibited endotoxin-induced aggregation. Plasma levels of adenine nucleotides were measured using ...
Frisbie DD, Oxford JT, Southwood L, Trotter GW, Rodkey WG, Steadman JR, Goodnight JL, McIlwraith CW.The current study investigated healing of large full-thickness articular cartilage defects during the first 8 weeks with and without penetration of the subchondral bone using microfracture in an established equine model of cartilage healing. Chondral defects in the weightbearing portion of the medial femoral condyle were made bilaterally; one defect in each horse was microfractured whereas the contralateral leg served as the control. The expression of cartilage extracellular matrix components (Types I and II collagen and aggrecan) was evaluated using histologic techniques, reverse transcriptio...
Zayed MN, Schumacher J, Misk N, Dhar MS.Mesenchymal stromal cells (MSCs) have the capacity to differentiate into cells of mesenchymal lineage, such as chondrocytes, and have potential for use in regeneration of equine articular cartilage. MSCs instilled intra-articularly would be exposed to the inflamed environment associated with equine osteoarthritis (OA), which may compromise their function and ability to heal a cartilaginous defect. The aim of this study was to assess the ability of equine adult MSCs to differentiate into chondrocytes when stimulated with pro-inflammatory cytokines. MSCs derived from equine bone marrow (BM) and ...
Jarvis GE, Atkinson BT, Snell DC, Watson SP.1. Various platelet membrane glycoproteins have been proposed as receptors for collagen, in some cases as receptors for specific collagen types. In this study we have compared the ability of a range of collagen types to activate platelets. 2. Bovine collagen types I-V, native equine tendon collagen fibrils and collagen-related peptide (CRP) all induced platelet aggregation and shape change. 3. Responses were abolished in FcRgamma chain-deficient platelets, which also lack GPVI, indicating a critical dependence on the GPVI/FcRgamma chain complex. 4. Responses to all collagens were unaffected in...
Uthamanthil RK, Edwards RB, Lu Y, Manley PA, Athanasiou KA, Markel MD.Chondromalacia can cause joint pain and synovial effusion with the potential for developing into osteoarthritis. Thermal chondroplasty using radiofrequency energy (RFE) has been reported to be superior to mechanical debridement for treating chondromalacia. We compared short-term changes in biomechanical properties of articular cartilage after treatment with monopolar (mRFE) or bipolar RFE (bRFE) or mechanical debridement (MD) on experimentally created grade II chondromalacia patellae. Chondromalacia patellae was created arthroscopically in both patellae of 15 ponies. Ten months after surgery, ...
Peffers MJ, Milner PI, Tew SR, Clegg PD.SOX9 is a transcription factor that is essential for cartilage extracellular matrix (ECM) formation. Osteoarthritis (OA) is characterised by a loss of cartilage ECM. In chondrocytes SOX9 gene expression is regulated by osmotic loading. Here we characterise SOX9 mRNA regulation through static and cyclical application of hyperosmotic conditions in normal and OA monolayer equine chondrocytes. Furthermore, we investigate whether extracellular signal-regulated protein kinase (ERK)1/2 mitogen-activated protein kinases (MAPK) pathways have a role in this regulation of SOX9. Methods: Equine chondrocyt...
Weng X, Cloutier G, Pibarot P, Durand LG.Erythrocyte aggregation levels in pig, horse, sheep, and calf blood samples were investigated and compared to that of normal human blood. The aggregation kinetics and adhesive forces between red cells, and an index of structure of the aggregates were determined with an erythroaggregameter (Regulest, France) at constant hematocrit (0.40 l/l) and temperature (37 degrees C). The adhesive forces and the index of structure in pig blood were close to those of normal human blood. The results for horse blood showed a very high level of aggregation kinetics and adhesive forces between red cells. For sh...
Frisbie DD, Mc Ilwraith CW, Arthur RM, Blea J, Baker VA, Billinghurst RC.Biomarkers have shown some in vivo promise for the detection of musculoskeletal injuries, but further study to assess biomarker levels in clinical orthopaedic disease is required. Objective: To assess 7 serum biomarkers for the detection of musculoskeletal injuries. Methods: Two- and 3-year-old racehorses were entered into the study (n = 238). Exit criteria were lack of training for >30 days, or completion of 10 study months. Data from horses with solitary musculoskeletal injuries and completion of >2 months were analysed. Musculoskeletal injury was considered intra-articular fragmentation (IA...
Griffin DJ, Ortved KF, Nixon AJ, Bonassar LJ.Several studies have demonstrated the benefits of IGF-I gene therapy in enhancing the histologic and biochemical content of cartilage repaired by chondrocyte transplantation. However, there is little to no data on the mechanical performance of IGF-I augmented cartilage grafts. This study evaluated the compressive properties of full-thickness chondral defects in the equine femur repaired with and without IGF-I gene therapy. Animals were randomly assigned to one of three study cohorts based on chondrocyte treatment provided in each defect: (i) IGF-I gene delivered by recombinant adeno-associated...
Fortier LA, Balkman CE, Sandell LJ, Ratcliffe A, Nixon AJ.This study evaluated the constitutive insulin-like growth factor-I (IGF-I) gene expression pattern in spontaneously healing cartilage defects over the course of 16 weeks, and correlated the tissue morphology and matrix gene expression with IGF-I mRNA levels. Full-thickness 15 mm cartilage defects were debrided in the femoral trochlea of both femoropatellar joints of 8 horses and the healing defects examined 2, 4, 8, or 16 weeks after surgery. Samples were harvested for histologic assessment of tissue healing using H&E staining, toluidine blue histochemical reaction for proteoglycan deposition,...
Bourebaba L, Michalak I, Baouche M, Kucharczyk K, Marycz K.Chondrogenesis represents a highly dynamic cellular process that leads to the establishment of various types of cartilage. However, when stress-related injuries occur, a rapid and efficient regeneration of the tissues is necessary to maintain cartilage integrity. Mesenchymal stem cells (MSCs) are known to exhibit high capacity for self-renewal and pluripotency effects, and thus play a pivotal role in the repair and regeneration of damaged cartilage. On the other hand, the influence of certain pathological conditions such as metabolic disorders on MSCs can seriously impair their regenerative pr...
Stewart AA, Byron CR, Pondenis HC, Stewart MC.To determine whether expansion of equine mesenchymal stem cells (MSCs) by use of fibroblast growth factor-2 (FGF-2) prior to supplementation with dexamethasone during the chondrogenic pellet culture phase would increase chondrocytic matrix markers without stimulating a hypertrophic chondrocytic phenotype. Methods: MSCs obtained from 5 young horses. Methods: First-passage equine monolayer MSCs were supplemented with medium containing FGF-2 (0 or 100 ng/mL). Confluent MSCs were transferred to pellet cultures and maintained in chondrogenic medium containing 0 or 10(7)M dexamethasone. Pellets were...
Neil KM, Orth MW, Coussens PM, Chan PS, Caron JP.To determine whether glucosamine and chondroitin sulfate (CS) at concentrations approximating those achieved in plasma by oral administration would influence gene expression of selected mediators of osteoarthritis in cytokine-stimulated equine articular chondrocytes. Methods: Samples of grossly normal articular cartilage obtained from the metacarpophalangeal joint of 13 horses. Methods: Equine chondrocytes in pellet culture were stimulated with a subsaturating dose of recombinant equine interleukin (reIL)-1beta. Effects of prior incubation with glucosamine (2.5 to 10.0 microg/mL) and CS (5.0 t...
Slauson DO, Skrabalak DS, Neilsen NR, Zwahlen RD.Equine neutrophils (PMN) were isolated from citrated normal blood by density gradient separation on Ficoll-Hypaque to greater than 96% purity and 98% viability and an average of 3.78 x 10(7) PMN/ml. The agonist C5a des Arg was used in serial dilutions of whole zymosan-activated equine plasma (ZAP) or was partially purified from ZAP by column chromatography. Purified equine PMN exhibited rapid aggregation following incubation with C5a des Arg which was further dependent on the availability of divalent cations, especially Mg++. The microfilament disruptive agent cytochalasin B (5 micrograms/50 m...
Henderson SE, Santangelo KS, Bertone AL.To determine effects of various concentrations of retinoic acid (RA) or a synthetic RA receptor antagonist (LE135) on equine chondrocytes or bone marrow-derived equine mesenchymal stem cells (BMDMSCs) in monolayer cultures. Methods: Articular cartilage and BMDMSCs from 5 clinically normal horses. Methods: Monolayers of chondrocytes cultured in standard media and of BMDMSCs cultured in chondrogenic media were treated with RA at concentrations of 0, 0.1, 1, or 10 μM or LE135 at concentrations of 0, 0.1, 1, or 10 μM on day 0. On days 7 and 14, samples were analyzed for DNA concentration, chondr...
Weiss DJ, Evanson OA, McClenahan D, Fagliari JJ, Jenkins K.To determine whether platelets are hyperaggregable or form platelet-neutrophil aggregates during the prodromal stages of acute laminitis of ponies. Methods: Healthy adult ponies: 8 experimental and 6 control. Methods: Acute laminitis was induced by oral administration of corn starch and wood flour to 8 ponies, and indices of platelet activation were evaluated. Blood samples were collected before and at 4, 8, 12, 24, 28, and 32 hours after carbohydrate administration, and PCV, total plasma protein concentration, platelet count, activated clotting time, whole blood recalcification time, spontane...
Spengler MI, Bertoluzzo SM, Catalani G, Rasia ML.The aim of the present paper is to analyze whether membrane fluidity can be predicted from its lipid composition and to assay the possible relationship between such variable and the aggregating properties of erythrocytes from equine, bovine and human species due to the widely acknowledged differences in their tendency to form aggregates. The main difference between phospholipids from plasma membrane in these species lies in the concentration levels of sphyngomyelin (SM) and phosphatidilcoline (PC); more precisely, in the external hemilayer of the lipid bilayer. Membrane fluidity was estimated ...
Johnstone IB, Viel L, Crane S, Whiting T.The purpose of this study was to determine whether a defect in hemostasis might be a factor in the etiology of exercise-induced pulmonary hemorrhage (EIPH). Hemostatic parameters were evaluated in 22 EIPH-positive and ten EIPH-negative racing horses while in a rested state. Nineteen EIPH-positive and ten EIPH-negative horses were further evaluated just before and immediately after a 15 min exercise period on a 260 m oval track. When EIPH-positive and EIPH-negative horses were compared at rest, there was no significant difference in any of the coagulation and fibrinolytic parameters studied. Th...
De Angelis E, Ravanetti F, Martelli P, Cacchioli A, Ivanovska A, Corradi A, Nasi S, Bianchera A, Passeri B, Canelli E, Bettini R, Borghetti P.The present study investigated the biocompatibility of chitosan films and scaffolds modified with d-(+)raffinose and their capability to support the growth and maintenance of the differentiation of articular chondrocytes in vitro. Primary equine articular chondrocytes were cultured on films and scaffolds of modified d-(+) raffinose chitosan. Their behavior was compared to that of chondrocytes grown in conventional bi- and three-dimensional culture systems, such as micromasses and alginate beads. Chitosan films maintained the phenotype of differentiated chondrocytes (typical round morphology) a...
Golonka P, Szklarz M, Kusz M, Marędziak M, Irwin Houston JM, Marycz K.One of the most common reasons for horse lameness is subchondral bone cysts (SBCs), which are especially evident in young horse athletes. It is believed that SBC development is strongly associated with an individual's bone growth and/or bone microstructure impairment. Current methods of SBC treatment include pharmacological treatment or surgical procedures which may allow the bone within the cyst to rebuild and be restored to properly developed bone tissue. Thus, we propose filling the SBCs with a 3D complex of alginate hydrogel and autologous adipose derived mesenchymal stem cells (ASCs). We ...
Baskurt OK, Bor-Kucukatay M, Yalcin O, Meiselman HJ.Differences of red blood cell (RBC) aggregation among various mammalian species has been previously reported for whole blood, for RBC in autologous plasma, and for washed RBC re-suspended in polymer solutions. The latter observation implies the role of cellular factors, yet comparative studies of such factors are relatively limited. The present study thus investigated RBC aggregation and RBC electrophoretic mobility (EPM) for guinea pigs, rabbits, rats, humans and horses; RBC were re-suspended in isotonic 500 kDa dextran solutions for the EPM and aggregation measurements, with aggregation stud...
Jarvis GE, Evans RJ, Heath MF.We have shown previously that endotoxin induces platelet aggregation in equine heparinised whole blood in a platelet-activating factor (PAF; 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) dependent manner. ADP is an agonist of platelets and is present in platelet dense granules with ATP in high concentrations. An investigation was carried out to establish whether endotoxin-induced platelet activation was associated with release of platelet ATP and ADP. ADP-scavenging enzyme systems significantly inhibited endotoxin-induced aggregation. Plasma levels of adenine nucleotides were measured using ...
MacLeod JN, Fubini SL, Gu DN, Tetreault JW, Todhunter RJ.To determine whether steady-state levels of type-II procollagen, aggrecan core protein, or fibronectin mRNA in articular chondrocytes are altered by synovitis or administration of methylprednisolone acetate (MPA). Methods: Articular cartilage specimens collected from 10 ponies, 2.5 to 3.5 years old and 200 to 300 kg. Methods: 4 experimental groups were compared, using the cartilage specimens: control, MPA-treated, lipopolysaccharide-induced synovitis, and lipopolysaccharide-induced synovitis with MPA treatment. RNA was isolated from articular cartilage and compared by northern blot analysis, u...
Mateos-Trigos G, Evans RJ, Heath MF.Horses show susceptibility to platelet-related disorders. Equine platelets differ from human platelets in some of their responses, so information available about human platelets must be validated in the horse. Aggregation of platelets by ADP involves both P2Y(1) and P2Y(12) receptors on the platelet surface. We have compared the effect of the P2Y(12) antagonist, AR-C67085, on equine and human platelets in vitro using turbidimetric aggregometry to measure the rate and final extent of aggregation. Aggregation profiles, concentration-response curves and pA(2) values show that the rate of aggregat...
Ramirez S, Gaunt SD, McClure JJ, Oliver J.Horse mares carrying mule foals were immunized during the last trimester of pregnancy with whole acid-citrate-dextrose-anticoagulated donkey blood to experimentally induce neonatal alloimmune thrombocytopenia. Thrombocytopenia occurred in the neonatal mule foals born to immunized horse mares within 24 hours after ingestion of their dams' colostrum. Mule foals born to mares not immunized with donkey blood did not develop thrombocytopenia. These findings suggest that antibodies may have been directed against a donkey platelet antigen present in the mule foals but not present in their dams. The o...
Basso RM, Andrade DGA, Alves CEF, Laufer-Amorim R, Borges AS, Oliveira-Filho JP.Dwarfism is a skeletal disorder that causes abnormal growth. In Miniature horses, dwarfism can occur as chondrodysplastic dwarfism, an autosomal recessive disorder associated with five mutations (D1, D2, D3*, D4 and c.6465A > T variant) in the aggrecan (ACAN) gene. The aim of this study was to evaluate the expression of aggrecan (at the gene and protein level) and specific cytokines (IL-1β, IL-6, and TNF-α) in the articular cartilage of Miniature horses with chondrodysplastic dwarfism (D4/c.6465A > T genotype). Metatarsal bone samples from eight dwarf Miniature horses were collected fo...
Mateos-Trigos G, Evans RJ, Heath MF.Platelet activation by adenosine 5' -diphosphate (ADP) is via both P2Y(1 )and P2Y(12) receptors and leads to shape change and aggregation. The effects on ADP-induced platelet shape change of two P2Y(1) antagonists, adenosine 3'-phosphate, 5'-phosphosulfate (A3P5PS) and 2-deoxy-N(6)-methyladenosine 3', 5'-diphosphate (MRS-2179) and a P2Y(12) antagonist 2-propylthio-D-beta,gamma-dichloromethylene-adenosine 5'-triphosphate (AR-C67085MX) were determined by turbidimetric aggregometry and scanning electron microscopy (SEM) on equine and human platelets. The platelet aggregation was inhibited during ...
Dillon AM, Heath MF.Protein tyrosine phosphorylation (PTP) in thrombin- and platelet-activating factor (PAF)-stimulated equine platelet activation was investigated in the absence and presence of 2 protein tyrosine kinase inhibitors (PTKIs), methyl 2,5-dihydroxycinnamate (MDHC) and genistein. Washed equine platelets aggregated irreversibly in response to thrombin or PAF in an agonist concentration dependent fashion. MDHC produced an MDHC concentration and time dependent inhibitory effect on rate and extent of thrombin- and PAF-induced aggregations, whereas the effect of genistein on the same parameters was only ge...
Poole AW, Heath MF, Evans RJ.Pre-incubation of equine platelets in platelet-rich plasma with adenosine 5'-diphosphate (ADP) induced a reduction in aggregation responsiveness to subsequent additions of ADP. The desensitisation was shown to be homologous since the responsiveness to platelet-activating factor, thrombin, collagen, 5-hydroxytryptamine or ionomycin remained unchanged. Adenosine 5'-(beta-thio)-diphosphate (ADP beta S), a non-hydrolysable analogue of ADP, was shown to act as an agonist inducing aggregation by interaction with the ADP receptor. ADP beta S was then used in the desensitisation studies in which resid...
Rotkina AS, Pronina IV, Lazarev VN, Akhaev DN, Baskova IP.The purpose. Identifying the capacity of the medicinal leech novel original recombinant thrombolytic preparation Destabilase-Lysozyme-2 to inhibit the blood platelet aggregation. Gene of destabilase-lysozyme. ds2 (mlDL-Ds2 ), was cloned in E.coli cells. Recombinant protein was isolated in denaturing conditions using metal-chelate chromatography followed by denaturation of the polypeptide by rapid dilution in exact accordance with the procedure described by Kurdyumov A.S. et al. ( 2016, Russian Journal of Bioorganic Chemistry, v.42, s. 42-52). Blood was collected from the jugular vein of 18 hor...
Heath MF, Evans RJ, Poole AW, Hayes LJ, McEvoy RJ, Littler RM.The responses of equine blood platelets in citrated platelet-rich plasma to arachidonic acid, U44069 (prostaglandin endoperoxide analogue), adenosine 5'-diphosphate, platelet-activating factor or collagen were investigated by turbidimetric aggregometry. Pre-treatment of the platelets with aspirin (1 mmol/l) or paracetamol (1.3 mmol/l) abolished shape change and aggregation in response to arachidonic acid; decreased the rate of aggregation in response to collagen, with no separate effect on shape change; had no marked effect on aggregation caused by the other agonists; but in no case transforme...
