Matrikine stimulation of equine synovial fibroblasts and chondrocytes results in an in vitro osteoarthritis phenotype.

Osteoarthritis (OA) is a debilitating disease that impacts millions of individuals and has limited therapeutic options. A significant hindrance to therapeutic discovery is the lack of in vitro OA models that translate reliably to in vivo preclinical animal models. An alternative to traditional inflammatory cytokine models is the matrikine stimulation model, in which fragments of matrix proteins naturally found in OA tissues and synovial fluid, are used to stimulate cells of the joint.

Ultrasoft platelet-like particles stop bleeding in rodent and porcine models of trauma.

Uncontrolled bleeding after trauma represents a substantial clinical problem. The current standard of care to treat bleeding after trauma is transfusion of blood products including platelets; however, donated platelets have a short shelf life, are in limited supply, and carry immunogenicity and contamination risks. Consequently, there is a critical need to develop hemostatic platelet alternatives.

Plasma and synovial fluid extracellular vesicles display altered microRNA profiles in horses with naturally occurring post-traumatic osteoarthritis: an exploratory study.

Objective: The objective of this study was to characterize extracellular vesicles (EVs) in plasma and synovial fluid obtained from horses with and without naturally occurring post-traumatic osteoarthritis (PTOA).

Animals: EVs were isolated from plasma and synovial fluid from horses with (n = 6) and without (n = 6) PTOA.

Methods: Plasma and synovial fluid EVs were characterized with respect to quantity, size, and surface markers.

IL-1β + TGF-β2 dual-licensed mesenchymal stem cells have reduced major histocompatibility class I expression and positively modulate tenocyte migration, metabolism, and gene expression.

Objective: The study objectives were to 1) determine the mesenchymal stem cell (MSC) surface expression of major histocompatibility complex (MHC) class I and transcriptome-wide gene expression changes following IL-1β + TGF-β2 dual licensing and 2) evaluate if IL-1β + TGF-β2 dual-licensed MSCs had a greater ability to positively modulate tenocyte function compared to naive MSCs.

Sample: Equine bone marrow-derived MSCs from 6 donors and equine superficial digital flexor tenocytes from 3 donors.

Methods: Experiments were performed in vitro.

Controlled Stiffness of Direct-Write, Near-Field Electrospun Gelatin Fibers Generates Differences in Tenocyte Morphology and Gene Expression.

Tendinopathy is a leading cause of mobility issues. Currently, the cell-matrix interactions involved in the development of tendinopathy are not fully understood. In vitro tendon models provide a unique tool for addressing this knowledge gap as they permit fine control over biochemical, micromechanical, and structural aspects of the local environment to explore cell-matrix interactions.

Mesenchymal stem cell licensing: enhancing MSC function as a translational approach for the treatment of tendon injury.

Tendon injuries are common in both veterinary and human clinical patients and result in morbidity, pain, and lost athletic performance. Consequently, utilizing naturally occurring injuries in veterinary patients as a comparative model could inform the development of novel therapies and increase translation for the treatment of human tendon injuries. Mesenchymal stem cells (MSCs) have shown considerable efficacy for the treatment of experimental and clinical superficial digital flexor tendon injury in the horse; however, the reinjury rate following treatment can remain high and MSC efficacy in treating other tendons is less well known.

Use of mesenchymal stem cells for tendon healing in veterinary and human medicine: getting to the "core" of the problem through a one health approach.

The purpose of this manuscript, which is part of the Currents in One Health series, is to take a comparative approach to stem cell treatment for tendon injury and consider how the horse might inform treatment in other veterinary species and humans. There is increasing experimental and clinical evidence for the use of bone marrow-derived mesenchymal stem cells to treat tendon injuries in the horse. The same evidence does not currently exist for other species.

Preclinical tendon and ligament models: Beyond the 3Rs (replacement, reduction, and refinement) to 5W1H (why, who, what, where, when, how).

Several tendon and ligament animal models were presented at the 2022 Orthopaedic Research Society Tendon Section Conference held at the University of Pennsylvania, May 5 to 7, 2022. A key objective of the breakout sessions at this meeting was to develop guidelines for the field, including for preclinical tendon and ligament animal models. This review summarizes the perspectives of experts for eight surgical small and large animal models of rotator cuff tear, flexor tendon transection, anterior cruciate ligament tear, and Achilles tendon injury using the framework: "Why, Who, What, Where, When, and How" (5W1H).

Biomechanical evaluation of interlocking nail and locking compression plating for stabilization of ovine critical-sized segmental tibia defects.

Background: Segmental large volume bone loss resulting from fracture or osseous neoplasia is a major challenge to orthopedic surgeons and there is an ongoing quest to identify treatments that optimize healing. To advance treatment, large animal translational models-such as the ovine critical-sized tibia defect model-are instrumental for testing of novel scaffolds for bone regeneration. However, little standardization in the implants utilized for defect stabilization has been determined and current commercially available implants may be inadequate to replicate the strength of the native tibia.

Pneumatic compression therapy using the EQ Press accelerates lymphatic flow in healthy equine forelimbs as determined by lymphoscintigraphy.

Objective: Limb lymphedema in horses can be debilitating and painful. Pneumatic compression therapy has shown significant benefits for people suffering from lymphedema. The objective of this study was to determine the effect of a novel, equine-specific pneumatic compression device on the lymphatic flow of healthy horse forelimbs as determined by Tc-99m sulfur colloid lymphoscintigraphy.

TGF-β2 enhances expression of equine bone marrow-derived mesenchymal stem cell paracrine factors with known associations to tendon healing.

Background: Mesenchymal stem cells (MSCs) secrete paracrine factors and extracellular matrix proteins that contribute to their ability to support tissue healing and regeneration. Both the transcriptome and the secretome of MSCs can be altered by treating the cells with cytokines, but neither have been thoroughly investigated following treatment with the specific cytokine transforming growth factor (TGF)-β2.

Methods: RNA-sequencing and western blotting were used to compare gene and protein expression between untreated and TGF-β2-treated equine bone marrow-derived MSCs (BM-MSCs).

Interleukin-1β in tendon injury enhances reparative gene and protein expression in mesenchymal stem cells.

Tendon injury in the horse carries a high morbidity and monetary burden. Despite appropriate therapy, reinjury is estimated to occur in 50-65% of cases. Although intralesional mesenchymal stem cell (MSC) therapy has improved tissue architecture and reinjury rates, the mechanisms by which they promote repair are still being investigated.

Clinical outcome of horses with guttural pouch infection following transpharyngeal fenestration.

Objective: To report the clinical outcomes of horses with chronic guttural pouch infection characterized by accumulation of mucopurulent material following transpharyngeal diode laser fenestration.

Animals: 13 client-owned horses.

Procedures: Horses undergoing diode laser fenestration for chronic guttural pouch infection were identified by medical record search.

Polyaxial pedicle screw external fixation to stabilize oblique mandibular fractures in three standing, sedated horses.

Objective: To report the radiographic, surgical and postoperative features in horses with unstable oblique mandibular fractures secured with polyaxial pedicle screws (PPS) external fixation construct and intraoral wiring.

Animals: Three client-owned horses.

Study Design: Short case series.

Laparoscopic Ovariectomy in a Domestic Yak.

Owners of a juvenile domestic yak elected bilateral ovariectomy to prevent future reproduction. The yak was noted to be healthy at presentation. Both ovaries were removed using a laparoscopic approach as follows: after induction and maintenance of general inhalant anesthesia, 15 degrees Trendelenburg positioning was required to view the ovaries.

Prospective randomized investigation of topical anesthesia during unilateral laparoscopic ovariectomy in horses.

Objective: To compare pain-related responses in mares receiving topical or injected anesthesia of the ovarian pedicle prior to standing unilateral laparoscopic ovariectomy.

Study Design: Prospective randomized, blinded, placebo-controlled study.

Animals: Fifteen healthy research mares.

Comparison of two techniques for transpharyngeal endoscopic auditory tube diverticulotomy in the horse.

Auditory tube diverticula, also known as guttural pouches, are naturally occurring dilations of the auditory tube in horses that communicate with the nasopharynx through a small ostium. Infection and select other conditions can result in inflammation and narrowing of the nasopharyngeal ostium, which prevents drainage of fluid or egress of air and can lead to persistent infection or guttural pouch tympany. Auditory tube diverticulotomy allows continuous egress from the auditory tube diverticula and is a feature of disease treatment in horses, in which medical treatment alone is not successful.