Glycosaminoglycans (GAGs) are long unbranched polysaccharides consisting of repeating disaccharide units that are found in various tissues and fluids in horses. They are integral components of connective tissues, contributing to the structural integrity and function of cartilage, tendons, and synovial fluid. GAGs are involved in maintaining joint health and facilitating smooth movement by providing lubrication and shock absorption. Common types of glycosaminoglycans in horses include chondroitin sulfate, dermatan sulfate, and hyaluronic acid. Changes in GAG levels and composition can be indicative of joint disorders or degenerative conditions in horses. This page compiles peer-reviewed research studies and scholarly articles that explore the biochemical properties, physiological roles, and clinical implications of glycosaminoglycans in equine health.
Yates AC, Stewart AA, Byron CR, Pondenis HC, Kaufmann KM, Constable PD.To determine the effects of sodium hyaluronate (HA) in combination with methylprednisolone acetate (MPA) on interleukin-1 (IL-1)-induced inflammation in equine articular cartilage pellets. Methods: Chondrocytes collected from 7 horses euthanatized for problems unrelated to the musculoskeletal system. Methods: Chondrocyte pellets were treated with medium (negative control); medium containing IL-1 (positive control); or medium containing IL-1 with MPA only (0.05 or 0.5 mg/mL), HA only (0.2 or 2 mg/mL), or MPA (0.05 or 0.5 mg/mL) and HA (0.2 or 2 mg/mL) in combination. Proteoglycan (PG) synthesis...
Changoor A, Hurtig MB, Runciman RJ, Quesnel AJ, Dickey JP, Lowerison M.To improve osteochondral graft reconstruction of subchondral cystic lesions in the medial and lateral femoral condyles by matching the material properties of donor and recipient sites. Objective: To measure biomechanical and biochemical parameters that influence the function and healing of osteochondral grafts used to reconstruct subchondral cystic lesions. Objective: Suitable donor sites are available within the stifle joint for reconstructing the femoral condyles, despite considerable regional property variation. Methods: Fifty-six osteochondral cores were harvested from 6 distal femurs for ...
de Grauw JC, Brama PA, Wiemer P, Brommer H, van de Lest CH, van Weeren PR.To assess whether reported alterations in metabolism of cartilage matrix in young (0 to 24 months old) horses with osteochondritis dissecans (OCD) may also be found in older (24 to 48 months old) horses with clinical signs of OCD and to investigate the role of eicosanoids in initiating these clinical signs. Methods: Synovial fluid was collected from 38 tarsocrural joints of 24 warmblood horses with (22 joints of 16 horses) or without (16 joints of 8 horses) clinical signs and a radiographic diagnosis of OCD of the distal intermediate ridge of the tibia. Methods: Turnover of type II collagen wa...
Weaver RE, Sharif M, Livingston LA, Andrews KL, Fuller CJ.The objective of this study was to assess whether macroscopically normal articular cartilage taken from joints containing focal osteoarthritic lesions is histologically similar to articular cartilage taken from macroscopically normal joints. Metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints were obtained from 10 horses following euthanasia. Gross articular cartilage damage was scored and the cartilage assigned to one of two groups: (1) macroscopically normal cartilage from normal joints (control) and (2) macroscopically normal cartilage from diseased joints in wh...
Gregg AJ, Fortier LA, Mohammed HO, Mayr KG, Miller BJ, Haupt JL.To evaluate the effects of interleukin (IL)-1beta on proteoglycan metabolism in equine cartilage explants when cultured in the presence of synoviocytes. Methods: Samples of cartilage and synovium collected from the femoropatellar joints of three 2- to 3-year-old horses. Methods: 3 experimental groups were established: cartilage explants only, synoviocytes only, and cartilage explants-synoviocytes in coculture. In each group, samples were cultured with or without IL-1beta (10 ng/mL) for 96 hours. Glycosaminoglycan (GAG) content of cartilage and medium samples was measured by use of a spectropho...
Huser CA, Davies ME.The objective of this study was the development and characterization of an in vitro model of the initiation of traumatic osteoarthritis (OA). Articular cartilage was obtained from seven healthy horses and from four horses diagnosed with OA. Cartilage disks were subjected to a single-impact load (500 g from 25, 50, or 100 mm) using a simple drop-tower device and cultured in vitro for up to 20 days. Cartilage sections were examined histologically to observe surface damage and proteoglycan loss. Percentage cell death was determined using TUNEL, release of glycosaminoglycans (GAG) to the medium wa...
Bolam CJ, Hurtig MB, Cruz A, McEwen BJ.To study osteoarthritis in the equine medial femorotibial (MFT) joint after a single traumatic injury. Methods: 10 mature horses. Methods: In vitro explant cultures were used to determine injury threshold for stifle joint cartilage. Contusive impacts were applied to the medial femoral condyle (MFC), and horses were followed for 84 (n = 5) and 180 days (5). Synovial fluid samples were collected every 14 days for determination of sulphated glycosaminoglycan (sGAG) concentrations. Radiographic and lameness evaluations were performed. Gross and histologic descriptions, and immunohistochemistry, ca...
Barnewitz D, Endres M, Krüger I, Becker A, Zimmermann J, Wilke I, Ringe J, Sittinger M, Kaps C.The objective of our study was to evaluate the integration of autologous cartilage tissue engineering transplants based on resorbable polyglactin/polydioxanone scaffolds into full-thickness cartilage defects of horses. Cartilage biopsies were taken from the non-load-bearing area of the lateral talus of the left tibiotarsal joint of eight healthy Haflinger horses. Tissue engineering cartilage transplants were generated by three-dimensional arrangement of autologous chondrocytes in biocompatible and resorbable polymer scaffolds. Full-thickness cartilage defects of 8 mm in diameter were created i...
Garcia-Seco E, Wilson DA, Cook JL, Kuroki K, Kreeger JM, Keegan KG.To determine normal cartilage stiffness values in different weight-bearing and non-weight-bearing areas of 3 different equine joints, and to evaluate the relationship between cartilage stiffness and glycosaminoglycan (GAG) and collagen content. Methods: Compressive stiffness of the articular cartilage was measured in 8 horse cadaver femoropatellar (FP), tarsocrural (TC), and metatarsophalangeal (MT) joints. Gross evaluation, collagen content, GAG content, and histologic appearance were assessed for each measurement location. Methods: Eight equine cadavers (4 intact females, 4 castrated males; ...
Fortier LA.Systemic therapies for joint disease may be prescribed when a single joint is involved or when multiple sites are affected. The precise therapeutic regimen recommended depends on the duration,cause, and site(s) of injury and is often an adjunct to intra-articular or supportive therapies. If the clinical signs of joint disease are acute and moderate in severity, nonsteroidal anti-inflammatory drugs are often administered to alleviate pain and inflammation. When aiming for more of a generalized maintenance or chondro-protective regimen, an alternative medication, such as hyaluronan,polysulfated ...
Lin YL, Brama PA, Kiers GH, DeGroot J, van Weeren PR.To quantify and compare biochemical characteristics of the extracellular matrix (ECM) of specimens harvested from tensional and compressive regions of the superficial digital flexor tendon (SDFT) of horses in age classes that include neonates to mature horses. Methods: Tendon specimens were collected on postmortem examination from 40 juvenile horses (0, 5, 12, and 36 months old) without macroscopically visible signs of tendonitis. Methods: Central core specimens of the SDFT were obtained with a 4-mm-diameter biopsy punch from 2 loaded sites, the central part of the mid-metacarpal region and th...
Biros DJ, Brooks DE, Brown MP, Merritt KA, Kubilis PS.To determine regional and zonal variation in sulfation patterns of chondroitin sulfate in normal equine corneal stroma. Methods: 22 normal eyes from 11 horses. Methods: Corneas were collected within 24 hours of death from equine necropsy specimens. After papain-chondroitinase digestion of corneal tissue, disaccharides deltaDi4S and deltaDi6S were quantified by use of capillary zone electrophoresis in the superficial, middle, and deep zones of central and peripheral regions of the cornea. Results: For the 2 regions combined, deltaDi6S/deltaDi4S values were significantly lower in the deep and mi...
van der Harst MR, DeGroot J, Kiers GH, Brama PA, van de Lest CH, van Weeren PR.To assess whether site-related changes in biochemical composition are present in the cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis. Methods: Right metacarpophalangeal joints from 59 mature warmblood horses. Methods: Biochemical data (cross-link, amino acid, DNA, and ash contents; denatured collagen and glycosaminoglycan [GAG] concentrations; bone mineral density; and mineral composition) were obtained from 2 differently loaded sites of phalanx I cartilage and subchondral and trabecular bone samples; data were compared with pr...
Desantis S, Ventriglia G, Zubani D, Corriero A, Deflorio M, Acone F, Palmieri G, De Metrio G.We investigated the oligosaccharide sequence of glycoconjugates, mainly sialoglycoconjugates, in the horse oviductal ampulla during oestrus by means of lectin and pre-lectin methods such as the KOH-neuraminidase procedure to remove sialic acid residues and incubation with N-glycosidase F to cleave N-linked glycans. Ciliated cells displayed N-linked oligosaccharides throughout the cytoplasm. The cilia glycocalyx expressed both N- and O-linked (mucin-type) oligosaccharides, both showing a high variety of terminal sequences. In the most non-ciliated cells, the whole cytoplasm contained N-linked o...
van den Boom R, van de Lest CH, Bull S, Brama RA, van Weeren PR, Barneveld A.The importance of osteoarthritis (OA) in the horse and the difficulty in its early diagnosis have led to a search for potential biomarkers of joint disease. If the levels of such markers are to be interpreted accurately, clinicians and researchers need to know whether they are influenced by environmental factors and/or interventions such as exercise and repeated arthrocentesis. Objective: To investigate the influence of repeated arthrocentesis and exercise on nitric oxide (NO), prostaglandin E2 (PGE2) and glycosaminoglycan (GAG) concentrations in synovial fluid (SF) from normal equine joints. ...
Dechant JE, Baxter GM, Frisbie DD, Trotter GW, McIlwraith CW.Clinical trials in human and veterinary literature have documented the benefits of oral nutraceutical joint supplements containing glucosamine (GU) and chondroitin sulphate (CS) to treat mild to moderate osteoarthritis, but the effects of these components have not yet been conclusively determined. Objective: To assess varying dosages of GU and CS on normal and interleukin-1alpha (IL-1) conditioned equine cartilage explants and rationalise the use of these products. Objective: Treatment would not be detrimental to cartilage metabolism and higher dosages and the combination of GU and CS would be...
Egerbacher M, Helmreich M, Probst A, König H, Böck P.Digital cushions were studied in horses with particular reference to vascularization, tissue constituents and matrix components. The cushions mainly resembled a network of coarse collagen bundles. The areas inbetween the bundles were replenished with loosely woven interstitial connective tissue, myxoid tissue, and fibrocartilage. Expected masses of fat lobules were missing: only solitary adipocytes or small groups of adipocytes were seen. Vascular supply to the cushions was remarkably poor. The mucinous myxoid matrix largely consisted of hyaluronan with little sulphated glycosaminoglycans. Myx...
Petrov R, MacDonald MH, Tesch AM, Benton HP.To investigate the effect of adenosine kinase inhibition on interleukin (IL)-1beta- and lipopolysaccharide (LPS)-induced cartilage damage. Methods: Articular cartilage was obtained from the metacarpophalangeal joints of 10 young adult horses. Following a stabilization period, weighed cartilage explants were exposed to IL-1beta (10 ng/ml) or LPS (50 microg/ml) to induce cartilage degradation. To test the potential protective effects of adenosine, these explants were simultaneously exposed to adenosine (100 microM), the adenosine kinase inhibitor 5'iodotubercidin (ITU, 1 microM) or to both adeno...
Desantis S, Acone F, Corriero A, Deflorio M, Zubani D, Ventriglia G, Palmieri G, De Metrio G.The distribution of sialic acid residues as well as other glycosidic sugars has been investigated in the horse oviductal isthmus during anoestrus, oestrus and pregnancy by means of lectin and pre-lectin methods. Ciliated cells and non-ciliated (secretory) cells exhibited different lectin binding profiles that were found to change during the investigated stages. Ciliated cells did not show any reactivity in the basal cytoplasm, while the supra-nuclear cytoplasm displayed a few of oligosaccharides with terminal and internal alphamannose (Man) and/or alphaglucose (Glc) during oestrus and pregnanc...
Little CB, Flannery CR, Hughes CE, Goodship A, Caterson B.To determine whether the focal susceptibility to cartilage degeneration in joints is related to a differential response to cytokine stimulation. Methods: Compare aggrecan and collagen catabolism in in-vitro models of cartilage degradation induced by retinoic acid (RA), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF) and IL-1 plus oncostatin M (OSM). Glycosaminoglycan (GAG) and hydroxyproline (HyPro) quantification and Western immunoblot analyses of aggrecan and collagen degradation products were undertaken in explant cultures of normal cartilage from regions of equine joints with a kno...
Doyle AJ, Stewart AA, Constable PD, Eurell JA, Freeman DE, Griffon DJ.To determine effects of sodium hyaluronate (HA) on corticosteroid-induced cartilage matrix catabolism in equine articular cartilage explants. Methods: 30 articular cartilage explants from fetlock joints of 5 adult horses without joint disease. Methods: Articular cartilage explants were treated with control medium or medium containing methylprednisolone acetate (MPA; 0.05, 0.5, or 5.0 mg/mL), HA (0.1, 1.0, or 1.5 mg/mL), or both. Proteoglycan (PG) synthesis was measured by incorporation of sulfur 35-labeled sodium sulphate into PGs, and PG degradation was measured by release of radiolabeled PGs...
Benton HP, Esquivel AV, Rice AD, Giri SN.Pirfenidone is under investigation as an anti-inflammatory and anti-fibrotic agent in several organs including lung. Since important features of arthritic conditions include inflammation and long-term damage to articular cartilage, we have investigated whether PD can suppress chondrocyte responses to bacterial lipopolysaccharide (LPS) and interleukin 1 (IL-1); modulators that induce a cascade of inflammatory responses that lead to articular joint tissue damage. PD (0 - 5microM) showed no effect on cell number or viability when incubated with high density primary equine chondrocyte cultures for...
van den Boom R, van der Harst MR, Brommer H, Brama PA, Barneveld A, van Weeren PR, DeGroot J.Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting horses and leads to degeneration of articular cartilage. Diagnosis is based on clinical signs in combination with radiography, which is relatively insensitive and provides only an indication of accumulated damage. Alternative methods, such as molecular markers, are therefore needed that can quantitatively, reliably and sensitively detect osteoarthritic changes in the joints at an early stage of the disease. If such markers are to be used reliably, it is important to know the relationship between marker ...
Popot MA, Bonnaire Y, Guéchot J, Toutain PL.Hyaluronic acid (HA) is an endogenous glycosaminoglycan used in the treatment of joint diseases, but medication control is required by horseracing authorities. Therefore, a medication control policy needs to be established. Objective: To establish physiological plasma HA concentrations in post race horses, determine the HA endogenous production rate and document the disposition of HA after i.v. and intra-articular hyaluronic acid administration at recommended therapeutic doses. Methods: Hyaluronan concentrations in plasma were determined using an ELISA specific test; concentrations in synovial...
van der Harst MR, Brama PA, van de Lest CH, Kiers GH, DeGroot J, van Weeren PR.In articular joints, the forces generated by locomotion are absorbed by the whole of cartilage, subchondral bone and underlying trabecular bone. The objective of this study is to test the hypothesis that regional differences in joint loading are related to clear and interrelated differences in the composition of the extracellular matrix (ECM) of all three weight-bearing constituents. Methods: Cartilage, subchondral- and trabecular bone samples from two differently loaded sites (site 1, dorsal joint margin; site 2, central area) of the proximal articular surface of 30 macroscopically normal equ...
Iqbal J, Bird JL, Hollander AP, Bayliss MT.This study was carried out to investigate the effect of two enzymes (collagenase and chondroitinase) and two cytokines/metabolites (interleukin-1beta and retinoic acid) of known catabolic activity on the expression of cartilage metabolism/phenotype in equine articular cartilage. Articular cartilage explants from 11 horses (5-13 years old) were treated for 48 h and assayed for total sulphated glycosaminoglycan (GAG), the incorporation of 35S-sulphate, collagen degradation and mRNA expression of the proteoglycans collagen II, collagen IIA, collagen III, collagen IX, collagen X, collagen XI and g...
Dyson SJ.There is a lack of long-term follow-up data for outcome of medical treatment of superficial digital flexor (SDF) tendonitis. Objective: To determine whether intralesional injection of hyaluronan, beta aminoproprionitrile fumarate (BAPN) or polysulphated glycosaminoglycans (PSGAG) or systemic administration of PSGAG yielded better results than a controlled exercise programme alone in the management of SDF tendonitis, with a minimum follow-up period of 2 years after resumption of full work; and to determine whether reinjury rate was related to sports discipline and whether fibre alignment score ...
van den Boom R, Brama PA, Kiers GH, de Groot J, van Weeren PR.To assess the effects of age and joint disease on hydroxyproline and glycosaminoglycan (GAG) concentrations in synovial fluid from the metacarpophalangeal joint of horses and evaluate the association of those concentrations with severity of osteoarthritis and general matrix metalloproteinase (MMP) activity. Methods: Synovial fluid was collected from the metacarpophalangeal joints of foals at birth (n = 10), 5-month-old foals (10), 11-month-old foals (5), and adult horses (73). Methods: Hydroxyproline and GAG concentrations were determined in synovial fluid samples. The severity of osteoarthrit...
Popot MA, Bonnaire Y, Guéchot J, Toutain PL.Hyaluronic acid (HA) is an endogenous glycosaminoglycan used in the treatment of joint diseases, but medication control is required by horseracing authorities. Therefore, a medication control policy needs to be established. Objective: To establish physiological plasma HA concentrations in post race horses, determine the HA endogenous production rate and document the disposition of HA after i.v. and intra-articular hyaluronic acid administration at recommended therapeutic doses. Methods: Hyaluronan concentrations in plasma were determined using an ELISA specific test; concentrations in synovial...
Glade MJ, Krook L, Schryver HF, Hintz HF.Epiphyseal and articular cartilages were examined in pony foals treated with intramuscular injections of either 0.5 mg dexamethasone per 100 kg bodyweight daily for 3, 8 or 11 months, or 5.0 mg per 100 kg for 11 months, and in horse foals treated with 5.0 mg per 100 kg for 20 weeks. The proximal femoral growth plates exhibited increased spatial separation between chondrocyte columns, narrowed zones of disorganized columnar and hypertrophic cartilage, abnormal penetration of hypertrophic cartilage by metaphyseal capillaries, retained cartilage in the spongiosa, distal terminal plate formation, ...
White JL, Salinas EY, Link JM, Hu JC, Athanasiou KA.A significant portion of equine lameness is localized to the stifle joint. Effective cartilage repair strategies are largely lacking, however, recent advances in surgical techniques, biomaterials, and cellular therapeutics have broadened the clinical strategies of cartilage repair. To date, no studies have been performed directly comparing neonatal and adult articular cartilage from the stifle across multiple sites. An understanding of the differences in properties between the therapeutic target cartilage (i.e., adult cartilage) as well as potential donor cartilage (i.e., neonatal cartilage) c...
Glade MJ.Low molecular weight polysulfated glycosaminoglycan (PSGAG) stimulated net collagen and glycosaminoglycan synthesis by normal and arthritic equine fetlock cartilage tissues in organ culture. Arthritic tissues were more sensitive to PSGAG stimulation. The rates of cartilage-specific type-II collagen and chondroitin sulfate-rich glycosaminoglycan synthesis by confluent chondrocyte cell cultures obtained from normal and arthritic equine cartilage tissues were increased by 25 and 50 mg of PSGAG/ml. Cells from arthritic cartilage were also more sensitive to the presence of PSGAG. In addition, conce...
Armstrong S, Lees P.To examine effects of carprofen (enantiomers and a racemic mixture) on the metabolism of equine chondrocytes. Methods: Cartilage from clinically normal horses. Methods: Effects of carprofen on proteoglycan neosynthesis, glycosaminoglycan (GAG) release and prostaglandin (PG) E2 production by unstimulated chondrocyte monolayers and cartilage explants were examined, as were similar variables in monolayers and explants exposed to carprofen and recombinant human interleukin 1beta (IL-1). Carprofen (enantiomers and racemic mixture) was used alone or along with IL-1 on monolayers and explant cultures...
Vachon AM, McIlwraith CW, Keeley FW.Periosteal autografts were used for repair of large osteochondral defects in 10 horses aged 2 to 3 years old. In each horse, osteochondral defects measuring 1.0 x 1.0 cm2 were induced bilaterally on the distal articular surface of each radial carpal bone. Control and experimental defects were drilled. Periosteum was harvested from the proximal portion of the tibia and was glued into the principal defects, using a fibrin adhesive. Control defects were glued, but were not grafted. Sixteen weeks after the grafting procedure, the quality of the repair tissue of control and grafted defects was asse...
Dechant JE, Baxter GM, Frisbie DD, Trotter GW, McIlwraith CW.Clinical trials in human and veterinary literature have documented the benefits of oral nutraceutical joint supplements containing glucosamine (GU) and chondroitin sulphate (CS) to treat mild to moderate osteoarthritis, but the effects of these components have not yet been conclusively determined. Objective: To assess varying dosages of GU and CS on normal and interleukin-1alpha (IL-1) conditioned equine cartilage explants and rationalise the use of these products. Objective: Treatment would not be detrimental to cartilage metabolism and higher dosages and the combination of GU and CS would be...
MacDonald MH, Stover SM, Willits NH, Benton HP.Explant cultures were set up, using articular cartilage obtained from metatarsophalangeal joints of 11 horses. Explants from 2 horses were used to determine culture conditions appropriate for tissue viability. The cartilage explants maintained steady-state metabolism of proteoglycans during a 13-day evaluation period. The metabolic response of equine articular cartilage to incubation with recombinant human interleukin 1 (0.01 to 100 ng/ml) was studied, using cartilage obtained from the remaining 9 horses, age of which ranged from 3 months to 20 years. Interleukin 1 induced a dose-dependent rel...
van den Boom R, van der Harst MR, Brommer H, Brama PA, Barneveld A, van Weeren PR, DeGroot J.Osteoarthritis (OA) is one of the most prevalent and disabling chronic conditions affecting horses and leads to degeneration of articular cartilage. Diagnosis is based on clinical signs in combination with radiography, which is relatively insensitive and provides only an indication of accumulated damage. Alternative methods, such as molecular markers, are therefore needed that can quantitatively, reliably and sensitively detect osteoarthritic changes in the joints at an early stage of the disease. If such markers are to be used reliably, it is important to know the relationship between marker ...
Dahlgren LA, Nixon AJ, Brower-Toland BD.To investigate effects of beta-aminopropionitrile and a combination of insulin-like growth factor (IGF)-I and beta-aminopropionitrile on metabolism of equine tendon fibroblasts. Methods: Flexor tendon explants from 3 horses. Methods: Explants received 1 of 4 treatments (control, IGF-I, beta-aminopropionitrile, and IGF-I/beta-aminopropionitrile) for 10 days, and message expression for collagen types I and III was assessed by use of in situ hybridization. Histologic findings, new protein production, and quantitative determinations of glycosaminoglycan, DNA, and de novo collagen synthesis were ma...
Grady JG, Elder SH, Ryan PL, Swiderski CE, Rashmir-Raven AM.Hereditary equine regional dermal asthenia (HERDA) is an autosomal recessive skin disorder that has yet to be fully characterized. HERDA is predominately expressed in Quarter Horses, with the majority of these disseminating from elite cutting horse bloodlines, leading to the increased incidence of HERDA in recent years. Affected horses have loose, hyper-extensible, fragile skin and are frequently euthanized due to poor wound healing and disfiguring scars. This study sought to better characterize HERDA by analysis of the biomechanical parameters of tensile strength, modulus of elasticity, energ...
Dart AJ, Little CB, Hughes CE, Chu O, Dowling BA, Hodgson DR, Rose RJ, Johnson KA.Recombinant equine growth hormone (reGH) has recently been evaluated for effects on body condition and wound healing. It has the potential to influence articular cartilage via stimulation of IGF-1. Objective: To investigate effects of administration on synovial joint metabolism. Methods: Six mature horses were given 20 microg/kg bwt reGH daily for 8 weeks by i.m. injection. Three control horses were injected with sterile water. Serum and synovial fluid samples were collected at 6, 8, 11 and 16 weeks for GH and IGF-1 assays. Articular cartilage harvested at week 16 was evaluated by Western anal...
Loredo GA, MacDonald MH, Benton HP.To investigate whether recombinant human bone morphogenetic protein-2 (rhBMP-2) regulates glycosaminoglycan (GAG) synthesis and release from equine articular cartilage explant cultures. Methods: Equine articular cartilage explants were maintained in vitro for 7 days in the presence of 0 (control), 1, 10, or 100 ng of rhBMP-2/ml. Synthesis and release of GAG were assessed as measures of production and degradation of the extracellular matrix, respectively. Methods: 6 horses (age range, 2 to 25 years old) without clinically detectable musculoskeletal abnormalities. Methods: Rate of synthesis of G...
Kobayashi A, Sugisaka M, Takehana K, Yamaguchi M, Eerdunchaolu , Iwasa EK, Abe M.This report compares the morphology and the concentrations of glycos-aminoglycans (GAGs) in an injured superficial digital flexor tendon (SDFT) of a horse with those of a normal tendon. An injured 6-year-old male Thoroughbred exhibited heat and swelling around the SDFT of the right forelimb. On histopathological examination, exuberant granulation was observed in the affected tendon, with activated tenocytes, angiogenesis, haemorrhage, and infiltration of small numbers of leucocytes. The collagen fibres were loosely packed and irregularly arranged. The diameter of control collagen fibrils was 2...
Okumura M, Tagami M, Fujinaga T.The role of keratan sulphate (KS) as a marker of cartilage metabolism was evaluated by using an in vitro model of equine articular cartilage. Articular cartilage was harvested from clinically healthy 6-month-old foals (n=3). Chondrocytes were centrifuged and cultured as pellets. Chondrocyte pellets were stimulated by insulin-like growth factor (IGF)-Ialpha or interleukin (IL)-1alpha for 2 weeks. The sulfated glycosaminoglycans (GAG) and antigenic KS concentrations in the culture media were measured by a 1,9-dimethyl-methylene blue (DMMB) colorimetric assay and an inhibition ELISA using a 1/14/...
Bodó G, Vásárhelyi G, Hangody L, Módis L.One Arabian and 5 Hungarian half-bred horses were used to study the macroscopic and microscopic survival of autologous osteochondral grafts in the weight-bearing surface of the medial femoral condyle (MFC). Grafts were harvested from the cranial surface of the medial femoral trochlea (MFT) under arthroscopic control. Three of them were transplanted into the weight-bearing surface of the contralateral MFC using an arthrotomy approach. Three months later this transplantation procedure was repeated on the opposite stifle joints in the same animals, but at that time transplantation was performed a...
Yovich JV, Trotter GW, McIlwraith CW, Norrdin RW.The effect of intra-articular polysulfated glycosaminoglycan (PSG) on repair of chemical and physical articular cartilage injuries was evaluated in 8 horses. In each horse, a partial- and a full-thickness articular cartilage defect was made on the distal articular surface of the radial carpal bone. In the contralateral middle carpal joint, a chemical articular cartilage injury was induced by injecting 50 mg of Na monoiodoacetate (MIA). Four of the 8 horses were not treated (controls), and 4 horses were treated by intra-articular injection of 250 mg of PSG into both middle carpal joints once a ...
Mäkelä OT, Lammi MJ, Uusitalo H, Viitanen M, Hyttinen MM, Jurvelin JS, Vuorio E, Helminen HJ, Tulamo RM.To analyze the effect of radiosynovectomy with holmium-166 ferric hydroxide macroaggregate (166Ho-FHMA) on articular cartilage in 6 adult horses. Methods: Arthritic changes and mechanical properties of articular cartilage were evaluated with arthroscopy and postmortem microscopic analyses. Glycosaminoglycan content was measured by safranin-O staining combined with digital densitometry, uronic acid analyses, and dimethylene blue binding assay. 35S-sulfate labeling and autoradiography were used to localize proteoglycan synthesis and to characterize proteoglycan structures using SDS-agarose gel e...
Belacic ZA, Sullivan SN, Rice HC, Durgam SS.To investigate the effects of interleukin-1β (IL-1β) and methylprednisolone acetate (MPA) on equine intrabursal deep digital flexor tendon (DDFT) and navicular bone fibrocartilage (NBF) cells in vitro. Methods: Third passage DDFT and NBF cells from 5 healthy donor horses ages 11-17 years euthanized for reasons unrelated to musculoskeletal conditions. Methods: Aggregate cultures were incubated with culture medium alone (control), 10 ng/mL IL-1β, 10 ng/mL IL-1β + 0.05 mg/mL MPA, or 10 ng/mL IL-1β + 0.5 mg/mL MPA for 24 hours. Extracellular matrix (ECM) gene expressions were assessed via rea...
Todhunter RJ, Minor RR, Wootton JA, Krook L, Burton-Wurster N, Lust G.Our aim was to determine if mild to moderate postoperative exercise and intra-articular polysulfated glycosaminoglycan result in improved repair of large, experimentally induced osteochondral defects in a weight-bearing surface of equine joints. Arthroscopic debridement was used to produce full-thickness defects in a weight-bearing area of the radial carpal bones in 18 ponies. The ponies were randomly assigned to two groups balanced for age: nine animals in the exercise and nine in the no exercise group. Six ponies in each group were medicated weekly for 5 weeks with an intra-articular injecti...
Boere J, van de Lest CHA, de Grauw JC, Plomp SGM, Libregts SFWM, Arkesteijn GJA, Malda J, Wauben MHM, van Weeren PR.Extracellular vesicle (EV) concentration, characteristics and function in equine synovial fluid (SF) during normal growth and development has not previously been studied. Isolation of EVs was performed in SF from three healthy foals and two adult horses by differential ultracentrifugation (10,000g and 200,000g); EVs were purified by sucrose density gradient floatation and analysed by high-resolution flow cytometry (FCM), buoyant density and western blotting. Additionally, repeated biomarker analysis of sulphated glycosaminoglycans (GAG), matrix metalloproteinase (MMP), C-terminal crosslinked t...
Oikawa M, Katayama Y, Yoshihara T, Kaneko M, Yoshikawa T.The morphology of the arteries in the uterine wall was studied in three multiparous aged mares that had suffered repeated pregnancy failure. The uterine wall arteries exhibited elastosis of the intima or adventitia, or both, resembling "physiological pregnancy sclerosis". In areas affected by elastosis, degeneration of the pre-existing elastic fibres and increased glycosaminoglycans were frequently observed. Newly formed elastic fibres were not evident. Delayed resorption due to disordered metabolic turnover of the elastin was thought to be an important factor in the pathogenesis of the arteri...
Lillich JD, Bertone AL, Malemud CJ, Weisbrode SE, Ruggles AJ, Stevenson S.To compare the biochemical, histochemical, and immunohistochemical profiles of articular cartilage from horses with naturally acquired distal tibial osteochondrosis (OC) with cartilage from a similar location in clinically normal horses. Methods: 9 affected horses (group 1, 16 OC lesions) and 4 control horses (group 2, 8 normal osteochondral specimens). Methods: OC specimens were collected during arthroscopic removal of the fragment, and control specimens were collected by aseptic osteotomy. Uronic acid, total protein, total glycosaminoglycan (GAG), chondroitin sulfate (CS), and keratan sulfat...
Platt D, Wells T, Bayliss MT.Equine chondrocytes were cultured in vitro for 30 days in ionically gelled alginate beads. The alginate polymerises into a stable gel in the presence of divalent cations (calcium), and rapid depolymerisation in the presence of a calcium chelator releases the viable chondrocytes. The chondrocytes maintained a spherical appearance for 30 days in culture, in marked contrast to monolayer cultures, which develop a dedifferentiated fibroblastic morphology. The major proteoglycan molecule produced by the encapsulated chondrocytes was aggrecan, of similar hydrodynamic size to aggrecan molecules presen...
Bertone AL, McIlwraith CW, Jones RL, Norrdin RW, Radin MJ.Both tarsocrural joints of 4 horses were inoculated with 1.5 X 10(5) colony-forming units of Staphylococcus aureus. On days 1, 3, and 6, each horse had one tarsocrural joint lavaged with a balanced electrolyte solution and had the contralateral tarsocrural joint lavaged with 0.1% povidone-iodine solution. All horses were orally administered trimethoprim (5 mg/kg)/sufadiazine (25 mg/kg) combination twice daily and phenylbutazone (2 g) once daily for the duration of the study (21 days). On days 0, 1, 3, 6, 9, 14, and 21, synovial fluid specimens were collected and analyzed for color, clarity, to...
Frean SP, Cambridge H, Lees P.The concentration-effect relationships of phenylbutazone, indomethacin, betamethasone, pentosan polysulphate (PPS) and polysulphated glycosaminoglycan (PSGAG), on proteoglycan synthesis by equine cultured chondrocytes grown in monolayers, and articular cartilage explants were measured. The effect of PSGAG on interleukin-1beta induced suppression of proteogycan synthesis was also investigated. Proteoglycan synthesis was measured by scintillation assay of radiolabelled sulphate (35SO4) incorporation. Polysulphated glycosaminoglycan and PPS stimulated proteoglycan synthesis in chondrocyte monolay...
Schmidt S, Abinzano F, Mensinga A, Teßmar J, Groll J, Malda J, Levato R, Blunk T.Identification of articular cartilage progenitor cells (ACPCs) has opened up new opportunities for cartilage repair. These cells may be used as alternatives for or in combination with mesenchymal stromal cells (MSCs) in cartilage engineering. However, their potential needs to be further investigated, since only a few studies have compared ACPCs and MSCs when cultured in hydrogels. Therefore, in this study, we compared chondrogenic differentiation of equine ACPCs and MSCs in agarose constructs as monocultures and as zonally layered co-cultures under both normoxic and hypoxic conditions. ACPCs a...
van den Hoogen BM, van den Lest CH, van Weeren PR, van Golde LM, Barneveld A.In this study, the effect of different exercise regimens on proteoglycan metabolism of articular cartilage was examined in 43 newborn foals randomly divided into 3 groups: a) box-rest, b) box-rest with training and c) free pasture exercise. They were subjected to these exercise regimens from ages 1 week to 5 months and at 5 months, 24 foals (8 from each group) were sacrificed to assess short-term exercise effects. The remaining 19 foals were subjected to the same regimen of light exercise for an additional 6 months before being sacrificed to evaluate possible long-term effects. Articular carti...
Todhunter RJ, Altman NS, Kallfelz FA, Nersesian P, Lust G.Combined blood pool and delayed images produced by use of 99mTc-methylene diphosphonate (99mTcMDP) were evaluated as an objective measurement of the response of equine joints with osteochondral defects to postoperative exercise and intra-articularly administered polysulfated glycosaminoglycan (PSGAG). Osteochondral defects (approx 2.4 x 0.9 cm) were induced arthroscopically in the dorsodistal radial carpal bones of 18 ponies. These ponies were randomized (while balancing for age [range 2 to 15; median, 5.0; mean, 5.1 years]) to 2 treatment groups. Nine ponies were assigned to be exercised, and...
