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Topic:Flow Cytometry
Flow cytometry is a technology used to analyze the physical and chemical characteristics of cells or particles in horses. This technique involves suspending cells in a fluid stream and passing them through a laser beam, where they are individually measured for various parameters such as size, complexity, and fluorescence intensity. In equine research, flow cytometry is applied to study immune cell populations, assess cellular responses to pathogens, and evaluate hematological parameters. It is a valuable tool for veterinary diagnostics, allowing for detailed analysis of blood and tissue samples. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings related to flow cytometry in equine health and disease.
In vitro Characteristics of Heterogeneous Equine Hoof Progenitor Cell Isolates. Damage to an ectodermal-mesodermal interface like that in the equine hoof and human finger nail bed can permanently alter tissue structure and associated function. The purpose of this study was to establish and validate culture of primary progenitor cell isolates from the ectodermal-mesodermal tissue junction in equine hooves, the stratum internum, with and without chronic inflammation known to contribute to lifelong tissue defects. The following were evaluated in hoof stratum internum cell isolates up to 5 cell passages (P): expansion capacity by cell doublings and doubling time; plasticity ...
Nortropane alkaloids as pharmacological chaperones in the rescue of equine adipose-derived mesenchymal stromal stem cells affected by metabolic syndrome through mitochondrial potentiation, endoplasmic reticulum stress mitigation and insulin resistance alleviation. Equine metabolic syndrome (EMS) refers to a cluster of associated abnormalities and metabolic disorders, including insulin resistance and adiposity. The numerous biological properties of mesenchymal stem cells (MSCs), including self-renewal and multipotency, have been the subject of many in-depth studies, for the management of EMS; however, it has been shown that this cell type may be affected by the condition, impairing thus seriously their therapeutic potential. Therefore, an attempt to rescue EMS adipose-derived stem cells (ASCs) with calystegines (polyhydroxylated alkaloids) that are endow...
The effect of hypoxia on chondrogenesis of equine synovial membrane-derived and bone marrow-derived mesenchymal stem cells. Joint injury is extremely common in equine athletes and post-traumatic osteoarthritis (PTOA), a progressive and debilitating disease, is estimated to affect 60% of horses in the USA. The limited potential for intrinsic healing of articular cartilage has prompted intense efforts to identify a cell-based repair strategy to prevent progression of PTOA. Mesenchymal stem cells (MSCs) have the potential to become an ideal source for cell-based treatment of cartilage lesions; however, full chondrogenic differentiation remains elusive. Due to the relatively low oxygen tension in articular cartilage, h...
Comparison of the Chondrogenic Differentiation Potential of Equine Synovial Membrane-Derived and Bone Marrow-Derived Mesenchymal Stem Cells. Focal cartilage injury occurs commonly and often precipitates OA. Mesenchymal stem cells (MSCs) may be useful for repairing cartilage lesions, thereby preventing joint degeneration. Although MSCs isolated from bone marrow have been shown to have chondrogenic potential, synovial membrane-derived MSCs (SM-MSCs) may have superior chondrogenic abilities due to a common progenitor cell between synovium and cartilage. The objective of this study was to directly compare the immunophenotype, proliferative capabilities, and chondrogenic potential of equine SM-MSCs and bone marrow-derived MSCs (BM-MSCs)...
Hypoxia and mesenchymal stromal cells as key drivers of initial fracture healing in an equine in vitro fracture hematoma model. Fractures in horses-whether simple fractures with just one clean break, or incomplete greenstick with stress fractures, or complications such as shattered bones can all be either minimal or even catastrophic. Thus, improvement in fracture healing is a hallmark in equine orthopedics. The fracture healing process implements a complex sequence of events including the initial inflammatory phase removing damaged tissue, re-establishment of vessels and mesenchymal stromal cells, a soft and hard callus phase closing the fracture gap as well as the remodeling phase shaping the bone to a scar-free tiss...
RAPID COMMUNICATION: TLR4 expressed but with reduced functionality on equine B lymphocytes. Varying susceptibility exists among mammalian species to the development of potentially fatal endotoxemia due to gram-negative bacteria molecular component, lipopolysaccharide (LPS). Toll-like receptor 4 (TLR4) is responsible for LPS-associated immune response and is expressed on numerous immune cells including B lymphocytes. TLR4 is expressed in a functional form on mouse B lymphocytes, a species much less susceptible to endotoxemia compared with humans who are highly sensitive to endotoxin. Humans possess B lymphocytes that are not responsive to LPS. Likewise, horses are highly susceptible t...
Equine platelet concentrate preparation and validation. Development of equine platelet concentrate (PC) would aid management of cases requiring transfused platelets (PLTs), where adminstration of whole-blood or platelet-rich plasma (PRP) might be contraindicated. Objective: To test and validate a method for production of an equine PRP-PC product. Methods: Six healthy Thoroughbred geldings from a research herd. Methods: In this prospective experimental study, whole blood was collected and processed through multiple centrifugation steps to yield 120 mL of PC. The PC was stored at 22°C and gently and continuously agitated. Measurements of PLT count...
The effect of age on foal monocyte-derived dendritic cell (MoDC) maturation and function after exposure to killed bacteria. Neonatal foals are uniquely susceptible to certain infections early in life. Dendritic cells (DC) are vital in the transition between the innate and adaptive immune response to infection, but DC biology in foals is not fully characterized. Monocyte-derived DC represent a suitable in vitro model similar to DC that differentiate from monocytes recruited from circulation. We hypothesized that foal monocyte-derived DC (MoDC) would exhibit age-dependent phenotypic and functional differences compared to adult horse MoDC. MoDC generated from 9 horses (collected once) and from 8 foals (collected at 1,...
Viability of Equine Chondrocytes After Exposure to Mepivacaine and Ropivacaine In Vitro. Chondrocyte health is altered when exposed to local anesthetics, raising concerns as to the long-term effects of local anesthetics intra-articularly for diagnosis and analgesia. To investigate the drug with the lowest toxic potential, the effect of ropivacaine and mepivacaine on chondrocytes was evaluated. Articular cartilage from normal metacarpophalangeal joints of five equine cadaver specimens was used to establish chondrocyte cultures. Following seven days, chondrocytes were exposed to standard culture medium (DMEM), ropivacaine 7.5 mg/ml (ROP7.5), ropivacaine 10 mg/ml (ROP10), mepivacaine...
Optimization of donkey sperm vitrification: Effect of sucrose, sperm concentration, volume and package (0.25 and 0.5 mL straws). The aim of this study was to assess the effect of different factors affecting vitrification success of donkey sperm: extender, sperm concentration, volume and storage vessel type. In Experiment 1, sucrose supplementations at 0.25 and 0.1 M were compared using two base extenders (containing or not egg-yolk); in Experiment 2, three sperm concentrations were assessed: 100, 200 or 300 million sperm/mL; and in Experiment 3, three different sperm volumes (100, 160 and 200 μL) and two different storage vessels (0.25 and 0.5 mL straws) were assessed. Sperm motility variables (CASA), plasma memb...
Evaluation of alginate hydrogel encapsulated mesenchymal stem cell migration in horses. Osteoarthritis is an incapacitating disease characterized by pain and a progressive decrease in joint mobility. The implantation of mesenchymal stem cells (MSCs) has shown promising results for its treatment. The challenge remains to keep the cells longer at the site of action, increasing their therapeutic potential. The aim of this study was to evaluate the effectiveness of the Qtracker® 655 nanocrystal marking on allogeneic synovial membrane (SM) MSCs, encapsulated in alginate hydrogel, evaluating the migration of these cells. The 10 radiocarpal joints were submitted to arthroscopic surgery...
Impact of post-thaw supplementation of semen extender with antioxidants on the quality and function variables of stallion spermatozoa. During cryopreservation procedures, the spermatozoa are exposed to physical and chemical stressors that generate an increase in the intracellular concentration of reactive oxygen species (ROS). If ROS concentrations are too great, this can lead to a state of oxidative stress that are detrimental to sperm quality. The aim of this study was to ascertain the profile the ROS production and assess the effects of post-thaw supplementation of a semen extender with different antioxidant compounds on the quality and function variables of frozen-thawed stallion spermatozoa incubated in vitro. Frozen-tha...
The serine protease testisin is present on the surface of capacitated stallion spermatozoa and interacts with key zona pellucida binding proteins. Serine proteases are emerging as important players in the spermatozoon's acquisition of functional competence. This study aimed to characterize the serine protease testisin (PRSS21) in stallion spermatozoa, examining its surface expression, possible origins in the testis and epididymis, and changes in response to capacitation and acrosome reaction, as well as its capacity to form high molecular weight complexes and interact with other proteins. The role of serine proteases in spontaneous capacitation and acrosome reaction of stallion spermatozoa was established using the serine protease inhibi...
Extracellular vesicles in synovial fluid from juvenile horses: No age-related changes in the quantitative profile. 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...
Antigen-specific CD4+ and CD8+ T-cell responses in PBMC from pony mares immunized with either native or recombinant zona pellucida vaccines. Few studies have investigated the cell mediated immune response during zona pellucida-based immunocontraception, despite hypothesized cytotoxic T-cell involvement in ovarian dysfunction associated with these vaccines. This study aimed to investigate antigen-specific anamnestic responses of helper (CD4) and cytotoxic (CD8) T-lymphocytes in peripheral blood mononuclear cells (PBMC) isolated from pony mares before and after their treatment with native porcine zona pellucida (pZP), recombinant pZP3 and pZP4 antigens (reZP) or adjuvanted saline. Mares were randomly assigned to pZP, reZP and control...
Pharmacokinetics and Pharmacodynamics of an Oral Formulation of Apixaban in Horses After Oral and Intravenous Administration. Horses with inflammatory and infectious disorders are often treated with injectable heparin anticoagulants to prevent thrombotic complications. In humans, a new class of direct oral acting anticoagulants (DOAC) appear as effective as heparin, while eliminating the need for daily injections. Our study in horses evaluated apixaban, a newly approved DOAC for human thromboprophylaxis targeting activated factor X (Xa). Our goals were to: (1) Determine pharmacokinetics and pharmacodynamics of apixaban after oral (PO) and intravenous (IV) administration in horses; (2) Detect any inhibitory effects of...
CXCL10 production in equine monocytes is stimulated by interferon-gamma. C-X-C motif ligand 10 (CXCL10) is a pro-inflammatory chemokine and has been extensively evaluated in people and mice. In horses, CXCL10 and its involvement in host immunity has rarely been analyzed due to the lack of specific antibodies. We generated a mAb specific for the equine chemokine CXCL10 using hybridoma technology. Antibody specificity was confirmed by intracellular staining and flow cytometric analysis of Chinese Hamster Ovary (CHO) cells expressing equine rCXCL10, while CHO cells expressing equine rCXCL9 were not detected. Native CXCL10 expression in PBMC from horses of different ag...
Hyperactivated stallion spermatozoa fail to exhibit a rheotaxis-like behaviour, unlike other species. The journey of spermatozoa through the female genital tract is facilitated by rheotaxis, or the cell's preference to swim against a flow, as well as thigmotaxis, the wall tracking behaviour, which guides them to the site of fertilisation. The aim of this study was to characterise the rheotactic and thigmotactic response of stallion sperm within a microfluidic channel. Stallion sperm rheotaxis was assessed within the microfluidic channel with regard to: (i) A range of flow velocities, (ii) Varying media viscosity and (iii) Sperm hyperactivation. Sperm distribution across the microfluidic channe...
Cooling and Cryopreservation of Equine Platelet-Rich Plasma With Dimethyl Sulfoxide and Trehalose. Equine platelet-rich plasma (PRP) has been used in horses to repair bone, articular and tendinous lesions, laminitis, and even endometritis. However, platelets have a very limited lifespan, which makes it difficult to prepare and use PRP, except in loco. With the aim to produce PRP with higher platelet viability for clinical purposes, the effects of the cryoprotectants dimethyl sulfoxide (DMSO) and trehalose were evaluated on cooled (4°C) and cryopreserved (-196°C) equine PRP. The protocols of cooling and cryopreservation were performed independently, comparing the following treatments: fres...
Establishment of Monoclonal Antibody PMab-202 Against Horse Podoplanin. Podoplanin (PDPN), a type I transmembrane glycoprotein, is expressed in several body tissues, including podocytes of renal glomerulus, type I alveolar cells of lung, and lymphatic endothelial cells. PDPN activates platelet aggregation by binding to C-type lectin-like receptor-2 (CLEC-2) presented on platelets. Monoclonal antibodies (mAbs) against human-, mouse-, rat-, rabbit-, dog-, bovine-, and cat-PDPN have already been established. However, anti-horse PDPN mAbs have not yet been developed. In this study, we immunized mice with synthetic horse PDPN peptides and developed anti-horse PDPN mAbs...
Evaluation of apoptosis markers in different cell lines infected with equine arteritis virus. Equine arteritis virus (EAV) induces apoptosis in infected cells. Cell death caused by EAV has been studied mainly using three cell lines, BHK-21, RK-13 and Vero cells. The mechanism of apoptosis varies among cell lines and results cannot be correlated owing to differences in EAV strains used. We evaluated different markers for apoptosis in BHK-21, RK-13 and Vero cell lines using the Bucyrus EAV reference strain. Acridine orange/ethidium bromide staining revealed morphological changes in infected cells, while flow cytometry indicated the extent of apoptosis. We also observed DNA fragmentation,...
Freezing, Vitrification, and Freeze-Drying of Equine Spermatozoa: Impact on Mitochondrial Membrane Potential, Lipid Peroxidation, and DNA Integrity. Maintaining the integrity of equine sperm subjected to preservation protocols is essential for the successful development of assisted reproduction procedures. The aim of this study was to assess the mitochondrial membrane potential, lipid peroxidation, and DNA integrity of equine sperm subjected to freezing, vitrification, and freeze-drying. Eight ejaculates obtained from four Colombian Creole horses were subjected to programmable freezing, vitrification, and freeze-drying. After thawing or rehydration, sperm motility and kinetics were assessed through a CASA system. The mitochondrial membrane...
Effect of human tubal fluid medium and hyperactivation inducers on stallion sperm capacitation and hyperactivation. Conventional in vitro fertilization has not yet been implemented in the equine species. One of the main reasons has been the inability to develop a culture medium and incubation conditions supporting high levels of stallion sperm capacitation and hyperactivation in vitro. Although different culture media have been used for this purpose, human tubal fluid (HTF) medium, widely used in the manipulation of human and mice gametes, has not been reported so far in stallion sperm culture. The first part of this study aimed to compare HTF and Whitten's media on different stallion sperm quality and capa...
C-C motif chemokine ligand (CCL) production in equine peripheral blood mononuclear cells identified by newly generated monoclonal antibodies. Chemokines are soluble molecules directing immune cell trafficking and homing, mediating inflammation, and initiating immune responses to infection. In horses, the analysis of chemokines has been limited by the lack of specific antibodies. We generated mAbs specific for the equine C-C motif chemokine ligands (CCL) CCL2 (MCP-1), CCL3 (MIP-1α), CCL5 (RANTES) and CCL11 (eotaxin) using hybridoma technology. Antibody specificity was confirmed by intracellular staining of Chinese Hamster Ovary cells transfected with expression vectors encoding for CCL2, CCL3, CCL5, or CCL11. Transfectants were stai...
Effect of antigen challenge on dynamics of CD62P and CD41/61 expression on platelets in horses with recurrent airway obstruction (RAO). Recurrent airway obstruction (RAO), also known as heaves, is an allergic respiratory condition that develops in horses following an exposure to aeroallergens in hay and straw. This is manifested by airway hyperreactivity, inflammation, bronchoconstriction, as well as a leukocyte and platelet infiltration into the airways. Platelet activation and an increase in circulating platelet-leukocyte aggregates may lead to airway remodeling. The aim of this study was to explore the effect of seven-day antigen challenge on dynamics of platelet indices and CD41/61 and CD62 P expression on platelets in h...
The Fate of Autologous Endometrial Mesenchymal Stromal Cells After Application in the Healthy Equine Uterus. Because of their distinct differentiation, immunomodulatory, and migratory capacities, endometrial mesenchymal stromal cells (MSCs) may provide an optimum source of therapeutic cells not only in relation to the uterus but also for regeneration of other tissues. This study reports the fate of endometrial MSCs following intrauterine application in mares. Stromal cell fractions were isolated from endometrial biopsies taken from seven reproductively healthy mares, expanded, and fluorescence labeled in culture. Phosphate-buffered saline (PBS) or MSCs (15 × 10) were autologously infused into ea...
Addition of seminal plasma to thawed stallion spermatozoa did not repair cryoinjuries. Freezing and thawing processes induce structural and functional damage to sperm plasma membranes and internal organelles. Adding seminal plasma (SP) has been found to minimize or repair the cryoinjuries in some species. The objective of this study was to investigate whether adding SP from stallions of known freezability after thawing could repair cryoinjuries. Semen was collected from warmblood stallions (n = 8, three ejaculates/stallion) and processed by Single Layer Centrifugation (SLC) to remove SP prior to freezing. Pooled SP (5%) from bad freezer (BF) or good freezer (GF) stallions wa...
Cell specific microvesicles vary with season and disease predisposition in healthy and previously laminitic ponies. Microvesicles are small (up to 1 μm) vesicles found in plasma and other bodily fluids. They are recognised as part of the normal system of inter-cellular communication but altered numbers are also used as biomarkers of disease. Microvesicles have not been studied in detail in the horse but may be relevant to diseases such as laminitis. Identification of equine cell specific microvesicles was performed by developing a panel of cross reactive antibodies to use in flow cytometry to detect microvesicles of platelet, leucocyte and endothelial origin in plasma from healthy ponies and those predis...
Effect of feeding pomegranate seed oil as a source of conjugated linolenic acid on Arabian stallion semen quality in cooled and postthawed condition. The objective was to assess the influence of pomegranate seed oil supplementation on the quality of fresh, cooled and frozen-thawed Arabian breed stallion semen. Eight stallions (n = 4 per group) received their normal diet (control group) or normal diet top dressed with 200 ml of pomegranate seed oil (PSO group). Semen was collected every fifteen days for 90 days. Stallions were reversed across the treatments after a sixty-day interval. In cooled and stored condition (2, 12 and 24 hr), spermatozoa motion characteristics, membrane integrity, viability, morphology and lipid peroxidation wer...
Evaluation of Oxidative Stress and Mitophagy during Adipogenic Differentiation of Adipose-Derived Stem Cells Isolated from Equine Metabolic Syndrome (EMS) Horses. Mesenchymal stem cells (MSCs) are frequently used in both human and veterinary medicine because their unique properties, such as modulating the immune response and differentiating into multiple lineages, make them a valuable tool in cell-based therapies. However, many studies have indicated the age-, lifestyle-, and disease-related deterioration of MSC regenerative characteristics. However, it still needs to be elucidated how the patient's health status affects the effectiveness of MSC differentiation. In the present study, we isolated mesenchymal stem cells from adipose tissue (adipose-derive...
