Overview of Equine Stem Cells: Sources, Practices, and Potential Safety Concerns.

Over the past 2 decades, equine veterinarians are turning increasingly to stem cell therapies to repair damaged tissues or to promote healing through modulation of the immune system. Research is ongoing into optimizing practices associated with stem cell product transport, dosage, and administration. Culture-expanded equine mesenchymal stem cell therapies seem safe, even when used allogeneically, but various safety concerns should be considered. Stem cells and cellular reprogramming tools hold great promise for future equine therapies.

Cytokine response as a biomarker for early diagnosis and outcome prediction of stem cell transplant recipients and acute leukemia patients with invasive aspergillosis.

We aimed to determine the role of serum cytokine expression in invasive aspergillosis (IA) diagnosis and outcome prediction in hematologic patients. In this multicenter study, serum cytokines (IL6, IL10, INF-gamma, IL12, IL4, TNF-alpha, IL17, and IL23) were prospectively recruited from all consecutive patients with hematologic malignances at IA diagnosis and compared to control patients matched by center, age, baseline disease, and therapeutic regimen. We included 36 patients with IA and 36 controls. Serum levels of IL6 and IL10 cytokines on day 0 were significantly increased in patients with IA when compared to controls (P = 0.001 and P = 0.025, respectively), even in those who were neutropenic. No differences were observed for the other cytokines. IL6 and IL10 predicted IA with an area under the ROC curve of 0.74 (95% CI 0.62-0.86) and 0.64 (95% CI 0.51-0.77), respectively. The best cutoff point in predicting IA was 20.85 pg/ml for IL6 (sensitivity 72.2%; specificity 77.8%; PPV 76.5% and NPV 73.7%), and 0.045 pg/ml for IL10 (sensitivity 62.9%; specificity 63.9%; PPV 62.9% and NPV 63.9%). IL6 levels were associated with increased mortality, with the best cutoff value being 65.59 pg/ml in mortality prediction. In conclusion, in addition to current tests in place, IL6 and IL10 levels-as measured in plasma-may help clinicians diagnose IA. High levels of IL6 at IA diagnosis are related with worse outcomes. LAY SUMMARY: We evaluated the role of serum cytokine expression in invasive aspergillosis (IA) diagnosis and outcome. Serum levels of IL6 and IL10 are increased in patients with IA compared to controls, and IL6 levels are associated with mortality.

Successful Spermatogonial Stem Cells Transplantation within Pleuronectiformes: First Breakthrough at inter-family Level in Marine Fish.

As a promising biotechnology, fish germ cell transplantation shows potentials in conservation germplasm resource, propagation of elite species, and generation of transgenic individuals. In this study, we successfully transplanted the Japanese flounder (P. olivaceus), summer flounder (P. dentatus), and turbot (S. maximus) spermatogonia into triploid Japanese flounder larvae, and achieved high transplantation efficiency of 100%, 75-95% and 33-50% by fluorescence tracking and molecular analysis, respectively. Eventually, donor-derived spermatozoa produced offspring by artificial insemination. We only found male and intersex chimeras in inter-family transplantations, while male and female chimeras in both intra-species and intra-genus transplantations. Moreover, the intersex chimeras could mature and produce turbot functional spermatozoa. We firstly realized inter-family transplantation in marine fish species. These results demonstrated successful spermatogonial stem cells transplantation within Pleuronectiformes, suggesting the germ cells migration, incorporation and maturation within order were conserved across a wide range of teleost species.

Male reproductive systems of Macaca mulatta: Gonadal development, spermatogenesis and applications in spermatogonia stem cell transplantation.

Rhesus macaque (Macaca mulatta) is widely applied in animal model construction of infertility, spermatogonia stem cell transplantation and male reproductive diseases. In this review, we describe the seasonal changes of the reproductive system in rhesus macaques, the regular pattern of spermatogenesis and spermatozoa maturation, and the differentiation of spermatogonia and spermatocytes. The duration of the M. mulatta spermatogenesis is approximately 10 days and seminiferous epithelium cycles mainly consist of 12 stages, which provide a suitable model for reproductive studies in non-human primates. Here, we summarize the features of gonadal development and sperm maturation in the rhesus monkeys, which provide important information in the studies of reproductive biology. Rhesus macaque is an excellent animal model in spermatogonia stem cell transplantation. We discuss the applications and progresses of assisted reproductive technologies in sperm liquefaction, semen cryopreservation and spermatogonia stem cell transplantation of rhesus macaques. Besides, we sort out recent proteomic analyses of male reproductive systems and semen samples in rhesus macaques. This review mainly focuses on male reproductive biology and application studies using M. mulatta, which would promote the development of new therapeutic interventions on assisted reproduction and reproductive disease studies in the future.

The Use of Bone Marrow-Derived Stem Cells in the Treatment of a Comminuted Tibiotarsal Fracture in a Juvenile Red-legged Seriema (Cariama cristata).

An adult red-legged seriema (Cariama cristata) presented with a comminuted fracture of the tibiotarsus and fibula. Surgery was performed, and a type II external fixator, with 2 distal and 2 proximal pins, was used to stabilize the fracture. After a 10-day stabilization period, the bird developed a second fracture on the same bone, proximal to the first fracture site. Another surgery was performed on the seriema similar to the first one. However, in this second surgical procedure a single pin, instead of 2 perpendicular pins, was placed proximally to the fracture site. After the second surgical procedure, bone marrow stem cells (BMSCs) from the seriema's left ulna were collected. Twenty-seven days after the second surgery, the BMSCs were transplanted, into the fracture sites. Twenty-four days after the stem cells were injected into the fractures (51 days after the second surgical procedure), radiographic images revealed healing bone calluses at the fracture sites. The fracture healing was relatively long for this case (a total of 75 days). The addition of bone marrow stem cell therapy to the use of external fixation may have contributed to the healing observed radiographically 24 days after administration; therefore, bone marrow stem cell therapy, in addition to traditional surgical fracture reduction and stabilization, may be a promising therapeutic approach for avian cases with similar injuries and bone anatomy. However, as this is a single case, this therapeutic modality deserves further application and study. Moreover, we suggest modifications in the bone marrow stem cell collection and therapy, which may be useful for future studies and application involving birds.

Aging- and temperature-related activity of spermatogonial stem cells for germ cell transplantation in medaka.

Spermatogonial transplantation can contribute to developing a novel method of producing seedlings for both aquaculture and biotic conservation. This study's purpose was to investigate aging- and temperature-related changes in the numbers and stem cell functions of type-A spermatogonia (ASG) in the model fish medaka (Oryzias latipes). The ASG numbers in medaka of different ages were quantified via histological observation and enzymatic dissociation of vasa-Gfp medaka testes. The ASG numbers were higher in eight-month-old medaka (maturation) than in four-month-old medaka (the onset of maturation). However, ASG numbers decreased in 18-month-old medaka (senescence). Low water temperature appeared to slow down both testis development and aging processes. To study the effects of aging on ASG stem cell activity, testicular cell suspensions containing GFP-expressed ASG were prepared from vasa-Gfp medaka donors at 4 and 18 months of age and transplanted into recipient hybrid larvae of medaka (O. latipes x O. curvinotus), which provided young stem-cell-niches. The findings revealed no significant differences in ASG colonization rates isolated from medaka of different ages. Each group displayed similar rates of germ-line transmission. Furthermore, water temperature had no significant effects on each ASG's stem cell activity. Taken together, these results indicated that aging and temperature affect ASG numbers. However, ASG isolated from medaka with different ages were transplanted into gonads with a young niche microenvironment, and there was no evidence of donor aging on stem cell activity.

Challenges of stem cell therapies in companion animal practice.

Regenerative medicine using stem cells from various sources are emerging treatment modality in several refractory diseases in veterinary medicine. It is well-known that stem cells can differentiate into specific cell types, self-renew, and regenerate. In addition, the unique immunomodulatory effects of stem cells have made stem cell transplantation a promising option for treating a wide range of disease and injuries. Recently, the medical demands for companion animals have been rapidly increasing, and certain disease conditions require alternative treatment options. In this review, we focused on stem cell application research in companion animals including experimental models, case reports and clinical trials in dogs and cats. The clinical studies and therapeutic protocols were categorized, evaluated and summarized according to the organ systems involved. The results indicate that evidence for the effectiveness of cell-based treatment in specific diseases or organ systems is not yet conclusive. Nonetheless, stem cell therapy may be a realistic treatment option in the near future, therefore, considerable efforts are needed to find optimized cell sources, cell numbers and delivery methods in order to standardize treatment methods and evaluation processes.

Successful transplantation of transfected enriched buffalo (Bubalus bubalis) spermatogonial stem cells to homologous recipients.

Genetic modification of spermatogonial stem cells (SSCs) is an alternative method to pronuclear microinjection and somatic cell nuclear transfer for transgenesis in large animals. In the present study, we optimized the process of homologous SSC transplantation in the water buffalo (Bubalus bubalis) using transfected enriched SSCs generated by a non-viral transfection approach. Firstly, the SSC enrichment efficiencies of extracellular matrix components viz. collagen, gelatin, and Datura stramonium agglutinin (DSA) lectin were determined either individually or in combination with Percoll density gradient centrifugation. The highest enrichment was achieved after differential plating with DSA lectin followed by Percoll density gradient centrifugation. Nucleofection showed greater transfection efficiency (68.55 ±â€¯4.56%, P < 0.05) for enriched SSCs in comparison to fugene HD (6.7 ±â€¯0.25%) and lipofectamine 3000 (15.57 ±â€¯0.74%). The transfected enriched SSCs were transplanted into buffalo males under the ultrasound guidance and testis was removed by castration after 7-8 weeks of transplantation. Persistence and localization of donor cells within recipient seminiferous tubules was confirmed using fluorescent microscopy. Further confirmation was done by flow cytometric evaluation of GFP expressing cells among those isolated from two-step enzymatic digestion of recipient testicular parenchyma. In conclusion, we demonstrated for the first time, generation of buffalo transfected enriched SSCs and their successful homologous transplantation in buffaloes. This study represents the first step towards genetic modifications in buffaloes using SSC transplantation technique.

Adipose stem cells in reparative goat mastitis mammary gland.

Mesenchymal stem cells have been widely used in the treatment of various chronic diseases. The objective of this survey was to evaluate the therapeutic and regenerative potential of stem cells from adipose tissue (ASCs) in the milk production recovery repair of tissue injury in mastitis goats treated with antimicrobial agents prior to cell therapy. After the diagnosis of mastitis and treatment with gentamicin, eight lactating goats were selected for cellular and subsequent therapy, physical-chemical analysis of milk, ultrasonographic and histopathological examinations. The ASCs were taken from the subcutaneous fat of a young goat cultivated in vitro, marked with Qdots-655 and injected in the left mammary gland, being the right mammary gland used as the control. After 30 days the ultrasonographic and histopathological analyzes were repeated and, in the first lactation period, the physical-chemical analysis of the milk was reapeated. Before the cellular therapy, the physical-chemical quality of the milk was compromised and the ultrasonographic and histopathological analysis revealed a chronic inflammatory process and fibrous tissue. The marking of the ASCs with Qdots enabled the tracking, by fluorescence microscopy (BX41-OLYMPUS), in the mammary tissue. In the ASCs therapy, cultures showed high cellularity and characteristics favorable to preclinical studies; with the therapy the physical-chemical parameters of the milk, fat, protein, temperature and pH showed significant differences among the groups; five animals treated with ASCs reconstituted the functionality of the gland and the connective tissue reduced in quantity and inflammatory infiltrate cells. ASCs have potential for the possible regeneration of fibrous mastitis lesions in the mammary gland, however, it would be necessary to increase injection time for the histopathological analysis, since the reconstitution of the glandular acini within the assessed period was not finalized. ASCs can be used to reestablish milk production in goat with chronic mastitis repair mammary lesions, with potential to be a promising clinical alternative for animal rehabilitation for productivity.

Bone marrow mononuclear cells versus mesenchymal stem cells from adipose tissue on bone healing in an Old World primate: can this be extrapolated to humans? / Células mononucleares de medula óssea versus células-tronco mesenquimais de tecido adiposo em cicatrização de lesão óssea em primata: pode ser extrapolado para humanos?

In veterinary medicine, the cell therapy is still unexplored and there are many unanswered questions that researchers tend to extrapolate to humans in an attempt to treat certain injuries. Investigating this subject in nonhuman primates turns out to be an unparalleled opportunity to better understand the dynamics of stem cells against some diseases. Thus, we aimed to compare the efficiency of bone marrow mononuclear cells (BMMCs) and mesenchymal stem cells (MSCs) from adipose tissue of Chlorocebus aethiops in induced bone injury. Ten animals were used, male adults subjected, to bone injury the iliac crests. The MSCs were isolated by and cultured. In an autologous manner, the BMMCs were infused in the right iliac crest, and MSCs from adipose tissue in the left iliac crest. After 4.8 months, the right iliac crests fully reconstructed, while left iliac crest continued to have obvious bone defects for up to 5.8 months after cell infusion. The best option for treatment of injuries with bone tissue loss in old world primates is to use autologous MSCs from adipose tissue, suggesting we can extrapolate the results to humans, since there is phylogenetic proximity between species.(AU)

Na medicina veterinária, a terapia celular ainda é inexplorada e há muitas perguntas não respondidas, o que leva os pesquisadores a uma tendência a estender a terapia para os seres humanos, na tentativa de tratar certas lesões. Investigar esse assunto em primatas não humanos revela-se uma oportunidade sem precedentes para compreender melhor a dinâmica das células-tronco contra algumas doenças. Assim, objetivou-se comparar a eficiência das células mononucleares de medula óssea (BMMCs) e das células-tronco mesenquimais (MSCs) do tecido adiposo de Chlorocebus aetiops na lesão óssea induzida. Foram utilizados 10 animais, adultos do sexo masculino, submetidos à lesão óssea nas cristas ilíacas. As MSCs foram isoladas e cultivadas; de forma autóloga, as BMMCs foram infundidas na crista ilíaca direita e as MSCs de tecido adiposo na crista ilíaca esquerda. Após 4,8 meses, a crista ilíaca direita foi totalmente reconstruída, enquanto a crista ilíaca esquerda continuou apresentando defeito ósseo evidente por até 5,8 meses após a infusão. A melhor opção para o tratamento de lesões com perda de tecido ósseo em primatas do Velho Mundo é a utilização de MSCs autólogas de tecido adiposo, sugerindo que se podem estender os resultados para seres humanos, uma vez que há proximidade filogenética entre as espécies.(AU)

Ultrasonic debridement with stem cell therapy of suspensory branch desmitis in an equine patient.

Ultrasonic debridement as a treatment for tendinopathy and desmitis is a relatively new approach in orthopedic surgery. Previously only used in limited cases, this procedure shows promise for treating ligament-bone and tendon-bone interface injuries. We present a case study of a 2-yr-old thoroughbred male horse, unable to train due to recalcitrant symptoms after extensive conservative management of suspensory branch desmitis. It was then treated with ultrasonic debridement and concurrent manubrial stem cell autograft injection, to treat the ultrasound visualized lesion. Post-surgically, the patient recovered quickly, began training within 16 wk, and went onto win several races. Repeat ultrasound imaging reveals a complete restoration of the internal fiber architecture of the ligament. With a 3-yr follow-up, there has been consistent training and race performance with no re-injury. This study is the first to document the successful outcome of ultrasonic debridement with concurrent stem cell injection in the treatment of equine desmitis.

Equine Mesenchymal Stem Cells: Properties, Sources, Characterization, and Potential Therapeutic Applications.

Properties like sustained multiplication and self-renewal, and homing and multilineage differentiation to undertake repair of the damaged tissues make stem cells the lifeline for any living system. Therefore, stem cell therapy is regarded to carry immense therapeutic potential. Though the dearth of understanding about the basic biological properties and pathways involved in therapeutic benefits currently limit the application of stem cells in humans as well as animals, there are innumerable reports that suggest clinical benefits of stem cell therapy in equine. Among various stem cell sources, currently adult mesenchymal stem cells (MSCs) are preferred for therapeutic application in horse owing to their easy availability, capacity to modulate inflammation, and promote healing. Also the cells carry very limited teratogenic risk compared to the pluripotent stem cells. Mesenchymal stem cells were earlier considered mainly for musculoskeletal tissues, but now may also be utilized in other diverse clinical problems in horse, and the results may be extrapolated even for human medicine. The current review highlights biological properties, sources, mechanisms, and potential therapeutic applications of stem cells in equine practice.

Spermatogonial Stem Cell Transplantation: Insights and Outlook for Domestic Animals.

The demand for food will increase to an unprecedented level over the next 30 years owing to human population expansion, thus necessitating an evolution that improves the efficiency of livestock production. Genetic gain to improve production traits of domestic animal populations is most effectively achieved via selective use of gametes from animals deemed to be elite, and this principle has been the basis of selective breeding strategies employed by humans for thousands of years. In modern-day animal agriculture, artificial insemination (AI) has been the staple of selective breeding programs, but it has inherent limitations for applications in beef cattle and pig production systems. In this review, we discuss the potential and current state of development for a concept termed Surrogate Sires as a next-generation breeding tool in livestock production. The scheme capitalizes on the capacity of spermatogonial stem cells to regenerate sperm production after isolation from donor testicular tissue and transfer into the testes of a recipient male that lacks endogenous germline, thereby allowing the surrogate male to produce offspring with the donor haplotype via natural mating. This concept provides an effective selective breeding tool to achieve genetic gain that is conducive for livestock production systems in which AI is difficult to implement.

Stem cells on regenerative and reproductive science in domestic animals.

Stem cells are undifferentiated and self-renewable cells that present new possibilities for both regenerative medicine and the understanding of early mammalian development. Adult multipotent stem cells are already widely used worldwide in human and veterinary medicine, and their therapeutic signalling, particularly with respect to immunomodulation, and their trophic properties have been intensively studied. The derivation of embryonic stem cells (ESCs) from domestic species, however, has been challenging, and the poor results do not reflect the successes obtained in mouse and human experiments. More recently, the generation of induced pluripotent stem cells (iPSCs) via the forced expression of specific transcription factors has been demonstrated in domestic species and has introduced new potentials in regenerative medicine and reproductive science based upon the ability of these cells to differentiate into a variety of cells types in vitro. For example, iPSCs have been differentiated into primordial germ-like cells (PGC-like cells, PGCLs) and functional gametes in mice. The possibility of using iPSCs from domestic species for this purpose would contribute significantly to reproductive technologies, offering unprecedented opportunities to restore fertility, to preserve endangered species and to generate transgenic animals for biomedical applications. Therefore, this review aims to provide an updated overview of adult multipotent stem cells and to discuss new possibilities introduced by the generation of iPSCs in domestic animals, highlighting the possibility of generating gametes in vitro via PGCL induction.

Subchondral bone cyst surgical treatment using the application of stem progenitor cells combined with alginate hydrogel in small joints in horses.

One of the most common reasons for horse lameness is subchondral bone cysts (SBCs), which are especially evident in young horse athletes. It is believed that SBC development is strongly associated with an individual's bone growth and/or bone microstructure impairment. Current methods of SBC treatment include pharmacological treatment or surgical procedures which may allow the bone within the cyst to rebuild and be restored to properly developed bone tissue. Thus, we propose filling the SBCs with a 3D complex of alginate hydrogel and autologous adipose derived mesenchymal stem cells (ASCs). We have observed at the in vitro level, that this hydrogel complex induces osteogenic and chondrogenic differentiation potential through the upregulation of bone morphogenetic protein, osteopontin, collagen type I and aggrecan mRNA levels. Moreover, we detected the creation of a 3D extracellular matrix (EM). To investigate the complex in vivo, we chose 8 horses of varying age suffering from SBC, which resulted in lameness, to undergo experimental surgery. We documented the horses' clinical appearance, lameness and radiographic appearance, to determine that there was clinical improvement in 87.75% of the patients (n=7, out of 8 horses) 6 months postoperatively and 100% (n=8, out of 8 horses) a year after surgery. These results are promising for the potential of this procedure to become the standard in SBC treatment.

Nerve Stimulator-guided Injection of Autologous Stem Cells Near the Equine Left Recurrent Laryngeal Nerve.

Recurrent laryngeal neuropathy (RLN) commonly affects horses and is characterized by abnormal respiratory sounds and exercise intolerance. The recurrent laryngeal nerve shows lesions of demyelination. The benefit of applying stem cells to demyelinated nerves has been demonstrated in various animal models. The aim of the study was to test the feasibility and safety of a peri-neuronal injection of autologous muscle-derived mesenchymal stem cells to the left recurrent laryngeal nerve in healthy horses by using an electrical nerve stimulator. Muscle-derived stems cell are obtained from five healthy Standardbred horses by sampling 20 mg of muscle tissue with a semi-automatic 14 G biopsy needle from the triceps muscle. Movements of the larynx are monitored via upper-airway video endoscopy. The left recurrent laryngeal nerve is approached with an insulated nerve block needle. Nerve stimulation is applied, starting at 2 mA, and the successful abduction of the left arytenoid is monitored. The stimulation intensity is reduced progressively. When a loss of the motor response is observed at 0.5 mA, 107 autologous muscle-derived stem cells are injected. Two examiners, who are blinded to the time point, score the laryngeal function of the horses prior to the treatment and at day 1, day 7, and day 28 after the injection of the cells. In a sixth horse, 1 mL of 2% lidocaine is injected to further confirm the correct positioning of the needle. This leads to a temporary paralysis of the left arytenoid cartilage. This study proves that the recurrent laryngeal nerve can be approached with the help of an electrical nerve stimulator and that the electrical stimulation of the nerve is well tolerated by the horses. No modification of the laryngeal function was observed in any of the horses after the injection of the stem cells. Further studies should be conducted to describe the effects of a peri-neuronal injection of autologous muscle-derived mesenchymal stem cells to horses suffering from RLN.

Estudio sobre quimerismo reverso y el efecto de la movilización de células madre de médula ósea sobre la expresión de citoquinas en un modelo experimental de trasplante de tejidos compuestos / Study on reverse chimerism and the effect of mobilization of bone marrow stem cells on the expression of cytokines in an experimental model of composite tissue transplantation

Introducción y Objetivo: Los trasplantes de tejidos compuestos sufren rechazo crónico modulado entre otros factores por citoquinas. El quimerismo reverso o quimerismo del aloinjerto se define como la repoblación del tejido trasplantado por células circulantes del receptor. Plerixafor produce la movilización de células madre de médula ósea CD34+ hacia la sangre periférica. El objetivo del estudio fue conocer los mecanismos moleculares que intervienen en el rechazo crónico y el quimerismo reverso tras la administración de plerixafor. Material y Método: Realizamos 16 trasplantes osteomusculares heterotópicos de pata posterior entre ratas Brown-Norway hembra y Wistar Lewis macho bajo inmunosupresión subterapéutica con tacrólimus. Establecimos 2 grupos de estudio según la administración postoperatoria de plerixafor. Transcurridas 9 semanas estudiamos la expresión de citoquinas y el infiltrado leucocitario en distintas localizaciones musculares, así como el grado de rechazo crónico y porcentaje de quimerismo reverso en diferentes tejidos del aloinjerto. Resultados: Encontramos diferencias estadísticas en la expresión de factor estimulante de colonias granulocíticas e interleucina 12 a nivel de los tercios medio y distal del aloinjerto, y de interleucina 6 a nivel del tercio medio del aloinjerto. La intensidad del infiltrado leucocitario fue mayor en el grupo que no recibió plerixafor. Ambos grupos desarrollaron rechazo crónico y pudimos observar la aparición de quimerismo reverso. Sin embargo no observamos diferencias significativas en el infiltrado leucocitario, el rechazo crónico ni el quimerismo reverso. Conclusiones: La movilización de células madre de médula ósea CD34+ se asoció con una menor expresión de factor estimulante de colonias granulocíticas, interleucina 6 e interleucina 12. Estos hallazgos contribuyen a elucidar los mecanismos moleculares que podrían conducir a la creación de quimeras en el aloinjerto

Background and Objective: Vascularized composite allotransplantation suffer chronic rejection modulated by cytokines. Reverse chimerism or allograft chimerism is defined as the repopulation of the transplanted tissue by circulating cells of the recipient. Plerixafor mobilizes CD34+ bone marrow stem cells to the peripheral blood. The aim of the study was to know the molecular mechanisms involved in chronic rejection and reverse chimerism after plerixafor administration. Methods: Sixteen heterotopic osteomuscular hindlimb transplants were performed between female Brown-Norway rats as donors and male Wistar Lewis rats as recipients under subtherapeutic immunosuppression with tacrolimus. Two groups were established according to the postoperative administration of plerixafor. After 9 weeks, expression of cytokines and leukocyte infiltration were studied in different muscle locations, as well as the degree of chronic rejection and percentage of reverse chimerism in different tissues of the allograft. Results: Statistical differences were found in granulocyte colony stimulating factor and interleukin 12 expression at middle and distal allograft thirds, and interleukin 6 expression at middle allograft third. The intensity of leukocyte infiltration was greater in the group that did not receive plerixafor. Both groups developed chronic rejection and the appearance of reverse chimerism could be observed. However, no significant differences were observed in leukocyte infiltration, chronic rejection or reverse chimerism. Conclusions: The mobilization of CD34+ bone marrow stem cells was associated with a lower expression of granulocytic colony stimulating factor, interleukin 6 and interleukin 12. These findings contribute to elucidate the molecular mechanisms that could lead to the creation of chimeras in the allograft

Combination therapy of canine osteosarcoma with canine bone marrow stem cells, bone morphogenetic protein and carboplatin in an in vivo model.

Osteosarcoma (OSA) is the most common malignant bone cancer in children and dogs. The therapeutic protocols adopted for dogs and humans are very similar, involving surgical options such as amputation. Besides surgical options, radiotherapy and chemotherapy also are adopted. However, hematologic, gastrointestinal and renal toxicity may occur because of chemotherapy treatments. Recent study clearly showed that mesenchymal stem cells (MSCs) combined with recombinant human bone morphogenetic protein (rhBMP-2) may be associated with decreases of the tumorigenic potential of canine OSA. The aim of this study was to analyse the efficacy of chemotherapy with carboplatin and rhBMP-2 with MSCs in a canine OSA in vivo model. Canine OSA cells were implanted in mice Balb-c/nude with MSCs, rhBMP-2 and carboplatin. Flow cytometry and PCR for markers involved in tumour suppression pathways were analysed. Results showed that the combination of MSCs and rhBMP-2 reduced tumour mass and infiltration of neoplastic cells in tissues more efficiently than carboplatin alone. Thus it was demonstrated that the use of rhBMP-2 and MSCs, in combination with conventional antineoplastic, may be an efficient treatment strategy.