Equine Hoof Stem Progenitor Cells (HPC) CD29 + /Nestin + /K15 + – a Novel Dermal/epidermal Stem Cell Population With a Potential Critical Role for Laminitis Treatment

Laminitis is a life threating, extremely painful and frequently recurrent disease of horses which affects hoof structure. It results from the disruption of blood flow to the laminae, contributing to laminitis and in severe separation of bone from the hoof capsule. Still, the pathophysiology of the disease remains unclear, mainly due to its complexity. In the light of the presented data, in the extremally difficult process of tissue structure restoration after disruption, a novel type of progenitor cells may be involved. Herein, we isolated and performed the initial characterization of stem progenitor cells isolated from the coronary corium of the equine feet (HPC). Phenotype of the cells was investigated with flow cytometry and RT-qPCR revealing the presence of nestin, CD29, and expression of progenitor cell markers including SOX2, OCT4, NANOG and K14. Morphology of HPC was investigated with light, confocal and SEM microscopes. Cultured cells were characterised by spindle shaped morphology, eccentric nuclei, elongated mitochondria, and high proliferation rate. Plasticity and multilineage differentiation potential was confirmed by specific staining and gene expression analysis. We conclude that HPC exhibit in vitro expansion and plasticity similar to mesenchymal stem cells, which can be isolated from the equine foot, and may be directly involved in the pathogenesis and recovery of laminitis. Obtained results are of importance to the field of laminitis treatment as determining the repairing cell populations could contribute to the discovery of novel therapeutic targets and agents including and cell‐based therapies for affected animals.

Impact of Horse Hoof Wall with Different Solid Surfaces

This study aimed to investigate the impact of a horse hoof wall on three solid surfaces: steel, concrete and asphalt. Impact experiments were conducted for different impact angles and different initial impact velocities. The effect of impact surfaces, impact angles and initial impact velocities on the coefficient of restitution and the effective coefficient of friction were tested using one-way ANOVA. Analytical and numerical modeling of the impact were developed. The impact interval was divided into two phases: compression and restitution. For compression, a contact force with a damping term was used. The restitution was characterized by an elastic contact force. The stiffness and damping coefficients of the contact force were estimated from the normal impacts. The simulated velocities after the oblique impacts were compared to the velocities in the in vitro investigation. The coefficient of restitution varied significantly on different surfaces. The effective coefficient of friction was lower on steel compared to concrete and asphalt. The model presented in this study can be applied to refine the impact simulation of the equine hoof during locomotion.

Mechanical nociceptive assessment of the equine hoof following distal interphalangeal joint intra-articular anesthesia

Background With the hypothesis that equine dorsal lamellar tissue can be desensitized by anesthesia injection into distal interphalangeal joint (DIPJ), the objective was to assess the mechanical nociceptive threshold of hoof dorsal lamellae following intra-articular (IA) administration of lidocaine into this joint. Methods The DIPJ of the forelimbs of six adult healthy horses were injected with either 5 mL of lidocaine, or 5 mL of lactated Ringer’s solution. Treatments were randomly distributed, with each forelimb undergoing a single treatment. The hooves were evaluated pre- and post-injection at pre-selected times over 4 h, using a pressure algometry model. Mechanical nociceptive thresholds (MNTs) were recorded for the sole (dorsal, palmarolateral, and palmaromedial regions), coronary band (medial, lateral, and dorsal regions), heel bulbs (medial and lateral), and dorsal lamellar region (2 cm and 4 cm distal to the coronary band). The MNT means were compared over time using the Friedman test and between treatments using the Wilcoxon signed-rank test, with values of P < 0.05 considered statistically significant. Results There were no differences between treatments for any region of the hoof during the evaluation period. However, MNT values indicating analgesia were recorded in the dorsal lamellar region in 50% of hooves following adminstration of lidocaine into the DIPJ. Conclusion The administration of 5 mL of lidocaine into the DIPJ does not significantly increase the mechanical nociceptive threshold of the equine hoof.

Equine Hoof Canker: Bovine Papillomavirus Infection Is Not Associated With Impaired Keratinocyte Differentiation

Impaired keratinocyte differentiation has recently been suggested as a key event in equine hoof canker development. Koilocytotic appearance of keratinocytes, one of the most characteristic morphological alterations in hoof canker tissue, is also a common marker for papillomavirus (PV) infection, and bovine PV-1 and/or -2 (BPV-1/2) has previously been detected in equine canker patients. Therefore, the present study aimed to correlate the frequency and severity of koilocytotic keratinocytes with BPV detection in hoof canker samples. Hoof tissue of 5/18 canker-affected horses and 2/6 control horses tested positive for BPV-1/2 DNA using polymerase chain reaction. Thus, no association between the presence of BPV-1/2 papillomaviral DNA and koilocytotic appearance was found. Proteins associated with but not specific for PV infection were also investigated. Using immunohistochemistry, specific adhesion molecules (E-cadherin and β-catenin) and intermediate filaments (keratins 6 and 14) important for intact epidermal barrier function and keratinocyte differentiation were documented in control samples ( n = 6) and in hoof canker tissue samples ( n = 19). Altered expression patterns of intermediate filaments and adhesion molecules were demonstrated in canker tissue, confirming the importance of incomplete keratinocyte differentiation, as well as the crucial role of keratinocyte differentiation in hoof canker.