Topic:Protein
Proteins are essential macromolecules that play diverse roles in the physiology and health of horses. They are composed of amino acids and are involved in various biological processes, including tissue growth, repair, and the synthesis of enzymes and hormones. Dietary proteins are a key component of equine nutrition, influencing muscle development, immune function, and overall performance. Horses require a balanced intake of essential amino acids, which must be obtained through their diet, as they cannot be synthesized endogenously. This page compiles peer-reviewed research studies and scholarly articles that explore the types, functions, and dietary requirements of proteins in horses, as well as their impact on equine health and performance.
Ageing does not result in a decline in cell synthetic activity in an injury prone tendon. Advancing age is a well-known risk factor for tendon disease. Energy-storing tendons [e.g., human Achilles, equine superficial digital flexor tendon (SDFT)] are particularly vulnerable and it is thought that injury occurs following an accumulation of micro-damage in the extracellular matrix (ECM). Several authors suggest that age-related micro-damage accumulates due to a failure of the aging cell population to maintain the ECM or an imbalance between anabolic and catabolic pathways. We hypothesized that ageing results in a decreased ability of tendon cells to synthesize matrix components and m...
Cloning and Expression of Iranian Turkmen-thoroughbred Horse Follicle Stimulating Hormone in Pichia pastoris. Follicle stimulating hormone (FSH) plays an essential role in reproductive physiology and follicular development. Objective: A new variant of the equine () gene was cloned, sequenced, and expressed in ) GS115 yeast expression system. Methods: The full-length cDNAs of the and chains were amplified by reverse transcription polymerase chain reaction (RT-PCR) using the total RNA isolated from an Iranian Turkmen-thoroughbred horse's anterior pituitary gland. The amplified chains were cloned into the pPIC9 vector and transferred into The secretion of recombined eFSH using expression system was...
Molecular dynamic simulations reveal the structural determinants of Fatty Acid binding to oxy-myoglobin. The mechanism(s) by which fatty acids are sequestered and transported in muscle have not been fully elucidated. A potential key player in this process is the protein myoglobin (Mb). Indeed, there is a catalogue of empirical evidence supporting direct interaction of globins with fatty acid metabolites; however, the binding pocket and regulation of the interaction remains to be established. In this study, we employed a computational strategy to elucidate the structural determinants of fatty acids (palmitic & oleic acid) binding to Mb. Sequence analysis and docking simulations with a horse (E...
AICAR administration affects glucose metabolism by upregulating the novel glucose transporter, GLUT8, in equine skeletal muscle. Equine metabolic syndrome is characterized by obesity and insulin resistance (IR). Currently, there is no effective pharmacological treatment for this insidious disease. Glucose uptake is mediated by a family of glucose transporters (GLUT), and is regulated by insulin-dependent and -independent pathways, including 5-AMP-activated protein kinase (AMPK). Importantly, the activation of AMPK, by 5-aminoimidazole-4-carboxamide-1-D-ribofuranoside (AICAR) stimulates glucose uptake in both healthy and diabetic humans. However, whether AICAR promotes glucose uptake in horses has not been established. I...
Characterization of the equine blood-testis barrier during tubular development in normal and cryptorchid stallions. The formation of the blood-testis barrier (BTB) is defined as occurring with the first appearance of spermatocytes at around puberty and is vital for normal spermatogenesis. This barrier between two adjacent Sertoli cells (SCs) consists of a cell junctional protein complex, which includes tight junctions (TJs), adherens junctions, and gap junctions. In many mammalian species, BTB composition has already been investigated, whereas little is known about the equine BTB. In the present study, immunohistochemistry and qualitative Western Blot analysis were used to assess the expression and distribu...
Characterising Non-Structural Protein NS4 of African Horse Sickness Virus. African horse sickness is a serious equid disease caused by the orbivirus African horse sickness virus (AHSV). The virus has ten double-stranded RNA genome segments encoding seven structural and three non-structural proteins. Recently, an additional protein was predicted to be encoded by genome segment 9 (Seg-9), which also encodes VP6, of most orbiviruses. This has since been confirmed in bluetongue virus and Great Island virus, and the non-structural protein was named NS4. In this study, in silico analysis of AHSV Seg-9 sequences revealed the existence of two main types of AHSV NS4, designat...
scAAVIL-1ra dosing trial in a large animal model and validation of long-term expression with repeat administration for osteoarthritis therapy. A gene therapeutic approach to treat osteoarthritis (OA) appears to be on the horizon for millions of people who suffer from this disease. Previously we described optimization of a scAAVIL-1ra gene therapeutic vector and initially tested this in an equine model verifying long-term intrasynovial IL-1ra protein at therapeutic levels. Using this vector, we carried out a dosing trial in six horses to verify protein levels and establish a dose that would express relevant levels of therapeutic protein for extended periods of time (8 months). A novel arthroscopic procedure used to detect green fluore...
Expression of leukaemia inhibitory factor at the conceptus?maternal interface during preimplantation development and in the endometrium during the oestrous cycle in the mare. Leukaemia inhibitory factor (LIF) plays a critical role in blastocyst development and implantation in several species. The present study investigated mRNA and protein expression for LIF, as well as the low-affinity LIF receptor (LIFR) and interleukin-6 signal transducer (IL6ST), in equine endometrium, trophoblast and histotroph during early pregnancy and in the endometrium during the oestrous cycle. Endometrial LIF mRNA expression was upregulated after Day 21 of pregnancy, whereas LIF immunoreactivity increased in the endometrium on Day 28. Expression of LIF mRNA in the yolk sac membrane incre...
The equine arteritis virus isolate from the 2010 Argentinian outbreak. A semen sample from a stallion infected during the 2010 equine arteritis virus (EAV) outbreak was received for viral isolation prior to castration of the animal. The virus was identified using a polyclonal antibody immunofluorescence test. Reverse-transcription polymerase chain reaction (RT-PCR) was used to amplify a region of the GP5 gene with primers GL105F and GL673R. The PCR products were purified and sequences of both strands were determined in a MegaBACE™1000 with inner primers CR2 and EAV32. A phylogenetic dataset was built with the previously reported sequences of five strains isolat...
Comprehensive protein profiling of synovial fluid in osteoarthritis following protein equalization. The aim of the study was to characterise the protein complement of synovial fluid (SF) in health and osteoarthritis (OA) using liquid chromatography mass spectrometry (LC-MS/MS) following peptide-based depletion of high abundance proteins. Methods: SF was used from nine normal and nine OA Thoroughbred horses. Samples were analysed with LC-MS/MS using a NanoAcquity™ LC coupled to an LTQ Orbitrap Velos. In order to enrich the lower-abundance protein fractions protein equalisation was first undertaken using ProteoMiner™. Progenesis-QI™ LC-MS software was used for label-free quantification. ...
Serum antibody immunoreactivity to equine zona protein after SpayVac vaccination. Immunocontraception with porcine ZP (pZP) can be an effective means of fertility control in feral horses. Previous studies suggest that antibodies produced after pZP vaccination may both inhibit fertilization and cause follicular dysgenesis. Zonastat-H, PZP-22, and SpayVac are three pZP vaccines proposed for use in horses. Although all these vaccines contain the pZP antigen, variations in antigen preparation and vaccine formulation lead to differences in antigenic properties among them. Likewise, despite numerous efficacy and safety studies of Zonastat-H and PZP-22, the contraceptive mechanism...
Proteomic alteration of equine monocyte-derived macrophages infected with equine infectious anemia virus. Similar to the well-studied viruses human immunodeficiency virus (HIV)-1 and simian immunodeficiency virus (SIV), equine infectious anemia virus (EIAV) is another member of the Lentivirus genus in the family Retroviridae. Previous studies revealed that interactions between EIAV and the host resulted in viral evolution in pathogenicity and immunogenicity, as well as adaptation to the host. Proteomic analysis has been performed to examine changes in protein expression and/or modification in host cells infected with viruses and has revealed useful information for virus-host interactions. In this ...
Species-specific effects on non-enzymatic metmyoglobin reduction in vitro. Our objectives were to determine the non-enzymatic metmyoglobin reduction properties of bovine, porcine, and equine myoglobins and to characterize the effects of pre-incubation of 4-hydroxy-2-nonenal (HNE) with myoglobins on non-enzymatic metmyoglobin reduction in vitro. Purified bovine, porcine, and equine metmyoglobins (0.05 mM) were reduced at pH 5.6 and 7.4 in the presence or absence of HNE. Rates of metmyoglobin reduction were monitored by spectrophotometry, and myoglobin adducts were characterized by high-resolution mass-spectrometry. Results showed that the species origins of individual...
Equine sperm-neutrophil binding. When mares are inseminated repeatedly, protein molecules from the seminal plasma (SP) prevent sperm-neutrophil binding and reduced fertility. The molecule(s) responsible for sperm-neutrophil binding is not known and the identification of beneficial SP proteins is complicated by their large numbers and abundant variation. We examined several important aspects of sperm-neutrophil binding to ultimately facilitate the identification and isolation of the molecule(s) responsible. First, we raised anti-equine P-selectin antibodies to determine the involvement of this adhesion molecule in sperm-neutro...
Novel monoclonal antibody against alphaX subunit from horse CD11c/CD18 integrin. The αX I-domain of the horse integrin CD11c was successfully expressed in Escherichia coli, purified, biochemically characterized and used as immunogen to generate murine monoclonal antibodies against horse CD11c, which are not yet commercially available. One monoclonal antibody mAb-1C4 against the αX I-domain, is an IgG2a able to interact with the recombinant I-domain, showing an EC50=2.4ng according to ELISA assays. By western blot with horse PBMCs lysates the mAb-1C4 recognized a protein of 150kDa which corresponds well with the CD11c molecule. Using immunohistochemistry in horse lymph no...
Structural characterisation of the virulence-associated protein VapG from the horse pathogen Rhodococcus equi. Virulence and host range in Rhodococcus equi depends on the variable pathogenicity island of their virulence plasmids. Notable gene products are a family of small secreted virulence-associated proteins (Vaps) that are critical to intramacrophagic proliferation. Equine-adapted strains, which cause severe pyogranulomatous pneumonia in foals, produce a cell-associated VapA that is necessary for virulence, alongside five other secreted homologues. In the absence of biochemical insight, attention has turned to the structures of these proteins to develop a functional hypothesis. Recent studies have ...
A new protein evaluation system for horse feed from literature data. Few data on apparent pre-caecal digestibility (APCD) of crude protein (CP) and particularly amino acids (AA) are available from studies with horses. Protein bound in cell walls (i.e. neutral detergent insoluble CP (NDICP)) is unlikely to be decomposed by digestive enzymes in the small intestine. In contrast the corresponding analytical fraction of neutral detergent soluble CP (NDSCP) (NDSCP = CP-NDICP) is likely to be available for auto-enzymatic digestion. A literature analysis on the relationship between NDICP/NDSCP and pre-caecal indigestible/digestible CP was carried out. There was a str...
Circulating immune complexes and markers of systemic inflammation in RAO-affected horses. The aim of this study was to investigate the levels of circulating immune complexes (CICs) and concentration of haptoglobin, fibrinogen and C-reactive protein in the serum of horses with recurrent airway obstruction and healthy controls. The study was conducted on a group of 14 adult Polish Konik horses, kept in uniform environmental and living conditions. Horses were divided into two groups: 7 horses were not affected by any respiratory problem (control group) and 7 horses had a history of recurrent airway obstruction (RAO) (study group). A clinical and laboratory evaluation, endoscopic exami...
Expression of monocarboxylate transporters I and IV and the ancillary protein CD147 in the intestinal tract of healthy horses and ponies. To characterize the expression of monocarboxylate transporters (MCTs) 1 and 4 and the ancillary protein CD147 in the intestinal tract of healthy equids and determine the cellular location of CD147 in the intestinal epithelium. Methods: 12 healthy horses and ponies slaughtered for meat production or euthanized for reasons unrelated to gastrointestinal tract disease. Methods: The entire gastrointestinal tract was removed from each equid within 45 minutes after slaughter or euthanasia. Tissue samples were obtained from the antimesenteric side of the duodenum, jejunum, ileum, middle part of the ce...
The recombinant equine LHβ subunit combines divergent intracellular traits of human LHβ and CGβ subunits. The pituitary LHβ and placental CGβ subunits are products of different genes in primates. The major structural difference between the two subunits is in the carboxy-terminal region, where the short carboxyl sequence of hLHβ is replaced by a longer O-glycosylated carboxy-terminal peptide in hCGβ. In association with this structural deviation, there are marked differences in the secretion kinetics and polarized routing of the two subunits. In equids, however, the CGβ and LHβ subunits are products of the same gene expressed in the placenta and pituitary (LHβ), and both contain a carboxy-te...
Distribution pattern(s) of sperm protein at 22 kDa (SP22) on fresh, cooled and frozen/thawed equine spermatozoa and expression of SP22 in tissues from the testes and epididymides of normal stallions. The objectives of this study were to (i) verify localization of SP22 on fresh, cooled, and frozen/thawed equine spermatozoa and to (ii) determine SP22 mRNA and protein expression in equine testicular and epididymal tissues. Immunocytochemistry and Western blots were performed on the spermatozoa samples. Northern blots and Western blots were performed on the tissue samples. The immunocytochemistry revealed the presence of SP22 in all samples tested. The fresh spermatozoa stained predominantly over the equatorial segment as did the samples cooled for 1 and 2 days. The samples cooled for 3 days, ...
Novel localization of peripherin 2, the photoreceptor-specific retinal degeneration slow protein, in retinal pigment epithelium. Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye. Since one typical feature of the autoimmune disease, equine recurrent uveitis (ERU), is the breakdown of this barrier, we recently performed comparative analysis of healthy and uveitic RPE. We identified for the first time peripherin 2, which is responsible for visual perception and retina development, to be localized in RPE. The purpose of this study was therefore to validate our findings by characterizing the expression patterns of peripherin 2 in RPE and retina. We also investigated whether peripherin 2 expr...
Comparative analysis of cryoprotective agents influence on thermodynamic and kinetic parameters of equine and human hemoglobin molecules. Critical to the understanding the mechanism of destruction and protection during cryopreservation of biological objects is the knowledge of the conformational transitions of biopolymers experiencing low temperatures in the presence of cryoprotective agents. This information may be derived from the kinetic and thermodynamic parameters of macromolecular thermal denaturation kinetics under different environmental conditions. Objective: The study deals with the influence of cryoprotective agents (glycerol, 1.2-propanediol (1.2-PD), and dimethyl sulfoxide (DMSO)) on thermodynamic and kinetic parame...
Alpha-fetoprotein is present in the fetal fluids and is increased in plasma of mares with experimentally induced ascending placentitis. The objectives of this study were to: (i) determine alpha-fetoprotein (AFP) concentrations in fetal fluids (FF), and (ii) compare plasma concentrations of AFP in mares with placentitis (n=17) and gestationally age-matched control mares (n=17). Fetal fluid sampling (FFS, n=7/group) was performed at 0, 5 and 12 days post inoculation (DPI) or until abortion. Plasma was harvested daily for 12 days or until abortion. Placentitis was induced via intracervical inoculation of Streptococcus equi ssp. zooepidemicus. Proteins present in the FF were resolved by 1D-SDS-PAGE, and immunoblotting was used to ...
The impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in eventing horses. This study was performed to evaluate the impact of dietary protein levels on nutrient digestibility and water and nitrogen balances in conditioning eventing horses. Twenty-four Brazilian Sport Horses, male and female (8.0 to 15.0 yr; 488 ± 32 kg BW), were used in a randomized design with 4 levels of CP diets: 7.5%, 9.0%, 11.0%, and 13.0%. A digestion assay was performed with partial feces collection over 4 d, followed by 1 d of total urine collection. Data were submitted to regression analysis and adjusted to linear and quadratic models (P < 0.05). No differences were observed in the intake o...
Tendon overload results in alterations in cell shape and increased markers of inflammation and matrix degradation. Tendon injury is thought to involve both damage accumulation within the matrix and an accompanying cell response. While several studies have characterized cell and matrix response in chronically injured tendons, few have assessed the initial response of tendon to overload-induced damage. In this study, we assessed cell response to cyclic loading. Fascicle bundles from the equine superficial digital flexor tendon were exposed to cyclic loading in vitro, designed to mimic a bout of high-intensity exercise. Changes in cell morphology and protein-level alterations in markers of matrix inflammation...
Immunological response and markers of cell damage in seropositive horses for Toxoplasma gondii. Toxoplasmosis is an important parasitic disease affecting several species of mammals, but little is known about this disease in horses. This study aimed to investigate the levels of several immunological variables and markers of cell damage in the serum of seropositive horses for Toxoplasma gondii. Sera samples of adult horses from the Santa Catarina State, Brazil used on a previous study were divided into groups according to their antibody levels for T. gondii determined by immunofluorescence assay, i.e. 20 samples from seronegative horses (Group A - control), 20 samples from horses with tite...
Differences in serum protein 2D gel electrophoresis patterns of Przewalski’s (Mongolian wild horse) and thoroughbred horses. The objective of this study was to assess differences in serum protein expression profiles of Przewalski's (Mongolian wild horse) and thoroughbred horses using proteome analysis. The serum proteins were separated by two-dimensional electrophoresis (2-DE) and five different gene products were identified. Proteins represented by the five spots were identified by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry (MS)/MS technology. The identities of all proteins were deduced based on their similarity to proteins in the human plasma protein database. Three pr...
Osteopontin expression in healing wounds of horses and in human keloids. Convincing evidence shows that persistent or excessive expression of osteopontin (OPN) is linked to fibroproliferation of various organs in laboratory animals and in man, such that its downregulation is a logical therapeutic objective. Objective: To investigate OPN expression in an equine model of wound healing and in clinical specimens of equine exuberant granulation tissue and human keloids in an effort to better understand the contribution of this protein to inflammation-associated skin fibrosis. Methods: Description of gene and protein expression in an experimental equine model of wound he...