Intravenous injection of allogenic canine mesenchymal stem cells in 40 client-owned dogs: a safety assessment in veterinary clinical trials.

BACKGROUND: The aim of this study was to evaluate the adverse effects of allogeneic mesenchymal stem cells (MSCs) transplanted via intravenous infusion in dogs and examine their safety. We performed a retrospective analysis of various clinical assessments, including physical examination, blood tests, and radiographs, and monitored the formation of neoplasms during a 6-month follow-up period in 40 client-owned dogs that received intravenous infusion of adipose tissue-derived MSCs (AT-MSCs) for the treatment of various underlying diseases between 2012 and 2018. RESULTS: No significant adverse effects of MSC therapy were detected by clinical assessment, blood tests, or radiographic examination in the 6-month follow-up period after the first MSC treatment. Additionally no new neoplasms were observed during this period. CONCLUSIONS: To our knowledge, this study is the first to evaluate the safety aspects (≥ 6 months) associated with intravenous allogeneic AT-MSC infusion. These results suggest that allogenic AT-MSC infusion could be a useful and relatively safe therapeutic approach in canines.

Mesenchymal stem cell transplantation: Systematic review, meta-analysis and clinical applications for acute kidney injury and chronic kidney disease in dogs and cats.

Chronic kidney disease (CKD) and acute kidney injury (AKI) are diseases which affect the urinary tract characterized by the loss of renal function. Their therapy requires different therapeutic goals. Mesenchymal stem cells (MSC) transplantation has spread over the years as a treatment for many diseases. In the urinary tract, studies report anti-inflammatory, antiapoptotic, antifibrotic, antioxidant and angiogenic effects. This work reports the results of a meta-analysis about the effects of the MSC application in serum levels of creatinine in dogs and cats with AKI and CKD. The work followed PRISMA guidelines. Data were screened, selected, and extracted with characteristics about the studies. The kinds of injury were classified according to their identification and the risk of bias was calculated by the system SYRCLE. The results of each group were combined by the inverse variance method. The heterogeneity was evaluated by the I2 test. For the mean of creatinine, a meta-analysis was performed according to the study group and number of applications and separately for the control and treatment groups according to the kind of injury, dose, application route, and moment. At all, 4742 articles were found. Of these, 40 were selected for eligibility, 16 underwent qualitative analysis and 9 to the quantitative. The results denote advantage to the group treated with MSC over placebo. A statistical difference was observed both in combined analysis and in the subgroups division. However, a high heterogeneity was found, which indicates considerable variation between the studies, which indicates caution in generalize the results.

Pulmonary passage of canine adipose tissue-derived mesenchymal stem cells through intravenous transplantation in mouse model.

IMPORTANCE: The intravenous administration of adipose tissue-derived mesenchymal stem cells (AdMSCs) in veterinary medicine is an attractive treatment option. On the other hand, it can result in severe complications, including pulmonary thromboembolism (PTE). OBJECTIVE: The present study assessed the occurrence of PTE after the intravenous infusion of canine AdMSCs (cAdMSCs) into experimental animals. METHODS: Five-week-old male BALB/c hairless mice were categorized into groups labeled A to G. In the control group (A), fluorescently stained 2 × 106 cAdMSCs were diluted in 200 µL of suspension and injected into the tail vein as a single bolus. The remaining groups included the following: group B with 5 × 106 cells, group C with 3 × 106 cells, group D with 1 × 106 cells, group E with 1 × 106 cells injected twice with a one-day interval, group F with 2 × 106 cells in 100 µL of suspension, and group G with 2 × 106 cells in 300 µL of suspension. RESULTS: Group D achieved a 100% survival rate, while none of the subjects in groups B and C survived (p = 0.002). Blood tests revealed a tendency for the D-dimer levels to increase as the cell dose increased (p = 0.006). The platelet count was higher in the low cell concentration groups and lower in the high cell concentration groups (p = 0.028). A histological examination revealed PTE in most deceased subjects (96.30%). CONCLUSIONS AND RELEVANCE: PTE was verified, and various variables were identified as potential contributing factors, including the cell dose, injection frequency, and suspension volume.

Evaluation of the restorative effect of ozone and chitosan-hyaluronic acid with and without mesenchymal stem cells on wound healing in rats.

This study evaluated the effect of ozone, chitosan-hyaluronic (Cs-HA) acid and mesenchymal stem cells (MSCs) on wound healing in rats. A total of 64 rats were randomly divided into four groups: control, ozone, Cs-HA + ozone and Cs-HA + ozone + MSCs. A 5 mm full-thickness wound was created on the back of each rat. The wound area was measured macroscopically on days 3, 5, 9 and 14. Tissue sections were prepared for histopathological evaluation of inflammation, collagen arrangement, neovascularization and epithelial tissue rearrangement. Macroscopic assessment showed differences in wound area on days 5, 9 and 14. Histopathological examination showed that the Cs-HA + ozone + MSCs and Cs-HA + ozone groups had significantly higher vascularization on day 3 compared to the ozone-treated and control groups. All treatment groups had significantly better collagen arrangement than the control group. On day 5, no significant difference was observed between different groups. On day 9, the inflammation level in the Cs-HA + ozone + MSCs group was significantly lower than in the other groups. All treatment groups had significantly better vascularization compared to the control group. On day 14, the rate of inflammation was significantly lower in the treatment groups than in the control group. Significantly higher collagen arrangement levels were observed in the Cs-HA + ozone and Cs-HA + ozone + MSCs groups compared to the control and ozone groups. All treatment groups had significantly better epithelial tissue rearrangement than the control group. Overall, the results of this study indicated that treatment with ozone, Cs-HA acid, Cs-HA and MSCs accelerated wound healing in rats. The effect of using Cs-HA acid with mesenchymal cells was better than the other types of treatment. Larger clinical trials are needed to assess these factors for improving chronic wound treatment.

Use of equine embryo -derived mesenchymal stromal cells and their extracellular vesicles as a treatment for persistent breeding-induced endometritis in susceptible mares.

Persistent breeding induced endometritis (PBIE) is a significant cause of infertility in mares. The development of a safe, universal, readily available therapeutic to manage PBIE and facilitate an optimal uterine environment for embryo development may improve pregnancy rates in susceptible mares. Mesenchymal stromal cells (MSCs) are being used increasingly as a therapeutic mediator for inflammatory conditions such as endometritis, and early gestational tissue provides a unique source of multipotent stem cells for creating MSCs. Extracellular vesicles (EVs) are mediators of cell communication produced by many different cell types. This study utilized embryo-derived mesenchymal stromal cells (EDMSCs) and their EVs as a potential therapeutic modality for PBIE in two groups: a) PBIE-susceptible mares challenged with pooled dead sperm (n=5); and b) client-owned mares diagnosed as susceptible to PBIE (n=37 mares and 40 estrous cycles). Mares pre-treated with intrauterine EDMSCs or their EVs resulted in a significant reduction in the accumulation of intrauterine fluid post-breeding. Nine of 19 (47 %) mares treated with EDMSCs prior to natural breeding and 13 of 20 (65 %) mares treated with EDMSC derived EVs were pregnant after the first cycle and 12 of 18 (67 %) mares treated with EDMSCs, and 15 of 19 (79 %) mares treated with EVs conceived by the end of the breeding season. These preliminary clinical studies are the first reports of the use of EDMSCs or their EVs as a potential intrauterine therapy for the management of PBIE susceptible mares.

Scoping review of the use of mesenchymal stem and stromal cell products in cats, Part 1: current logistics and safety.

Despite a pressing need for new therapies to address unmet veterinary medical need, no approved stem cell products are available for use in cats in the US. To evaluate the current state of mesenchymal stem or stromal cell (MSC) research in cats, a scoping review of published literature was performed, which identified 108 publications related to feline MSCs. Twenty-six of the articles described administration of MSC products to a total of 215 cats. Twelve of the studies included a control group. These experimental and clinical trials used 7 cell sources, 9 administration routes, 12 delivery vehicles, and a 300-fold range in dosages for initial studies in healthy cats and cats with 12 naturally occurring and induced diseases. The majority of studies administered 2 doses of allogeneic, adipose-derived MSC IV and monitored a median of 6.5 treated cats for a median of 90 days. The majority (150/215 [69.8%]) of cats had no reported adverse events associated with treatment. Although an increase in feline MSC publications in the past 10 years indicates progress, the wide variety and small number of studies using MSCs and MSC products in cats demonstrates that current evaluations are mostly still in the discovery phase, and several issues remain related to larger scale trials using MSC products in cats. The current available publications provide information to direct further clinical study development and informed owner consent for study enrollment.

Scoping review of the use of mesenchymal stem and stromal cell products in cats, Part 2: current scope and efficacy.

A scoping review of published literature found 108 articles related to mesenchymal stem or stromal cell (MSC) use in cats. Twenty-four of the publications summarized the treatment of 192 cats with MSC products for 12 naturally occurring and induced diseases. These trials used a variety of cell sources, administration routes, delivery vehicles, and dosages. The majority of studies did not have a control group. The disease with the largest number of cats administered MSCs thus far is chronic kidney disease (n = 59 cats). The majority of cats had no adverse events associated with treatment, which supports continued interest in the potential use of MSC products to address unmet medical needs. Treatment outcomes of the 192 cats have ranged from no response to long-term cure, depending on the disease being treated and the particular study. Some of these early studies show promise and provide significant information to direct both the design and focus of larger clinical trials investigating the safety and efficacy of MSC treatment for veterinary and human applications.

Minimal criteria for reporting mesenchymal stem cells in veterinary regenerative medicine.

The widespread application of mesenchymal stem cells (MSCs) in veterinary regenerative medicine highlights their promising therapeutic potential. However, the lack of standardized characterization and reporting practices across studies poses a significant challenge, compromising the assessment of their safety and efficacy. While criteria established for human MSCs serve as a foundation, the unique characteristics of animal-derived MSCs warrant updated guidelines tailored to veterinary medicine. A recent position statement outlining minimal reporting criteria for MSCs in veterinary research reflects efforts to address this need, aiming to enhance research quality and reproducibility. Standardized reporting criteria ensure transparency, facilitate evidence synthesis, and promote best practices adoption in MSC isolation, characterization, and administration. Adherence to minimal reporting criteria is crucial for maintaining scientific rigor and advancing the field of veterinary regenerative medicine. Ongoing collaboration among stakeholders is essential for effective implementation and adherence to updated guidelines, fostering excellence and innovation in MSC-based therapies for animal patients.

Evaluation of canine adipose-derived mesenchymal stem cells for neurological functional recovery in a rat model of traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) is a common condition in veterinary medicine that is difficult to manage.Veterinary regenerative therapy based on adipose mesenchymal stem cells seem to be an effective strategy for the treatment of traumatic brain injury. In this study, we evaluated therapeutic efficacy of canine Adipose-derived mesenchymal stem cells (AD-MSCs)in a rat TBI model, in terms of improved nerve function and anti-neuroinflammation. RESULTS: Canine AD-MSCs promoted neural functional recovery, reduced neuronal apoptosis, and inhibited the activation of microglia and astrocytes in TBI rats. According to the results in vivo, we further investigated the regulatory mechanism of AD-MSCs on activated microglia by co-culture in vitro. Finally, we found that canine AD-MSCs promoted their polarization to the M2 phenotype, and inhibited their polarization to the M1 phenotype. What's more, AD-MSCs could reduce the migration, proliferation and Inflammatory cytokines of activated microglia, which is able to inhibit inflammation in the central system. CONCLUSIONS: Collectively, the present study demonstrates that transplantation of canine AD-MSCs can promote functional recovery in TBI rats via inhibition of neuronal apoptosis, glial cell activation and central system inflammation, thus providing a theoretical basis for canine AD-MSCs therapy for TBI in veterinary clinic.

Stem cells and platelet-rich plasma for the treatment of naturally occurring equine tendon and ligament injuries: a systematic review and meta-analysis.

BACKGROUND: Platelet-rich plasma (PRP) and mesenchymal stromal or stem cells (MSCs) have been investigated as treatments for equine tendon and ligament injuries, but little consensus exists on the efficacy of these treatments. The study sought to evaluate the efficacy of PRP and MSC treatments by systematic review and meta-analysis. METHODS: A systematic review was performed using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Inclusion criteria required an original, peer-reviewed study where horses were administered MSCs or PRP (or both), and a comparator group was described. Studies were assessed for risk of bias and study quality. Random effects meta-analysis with inverse variance weighting was used to calculate pooled estimates of the ORs for the primary outcomes of return to performance and reinjury. RESULTS: The search criteria identified 764 unique studies, and 21 studies met the inclusion criteria for the systematic review. Seventeen studies were further assessed for the primary outcomes of return to performance and reinjury rate within a meta-analysis. Meta-analyses revealed no increase in the likelihood of a return to performance with any of the biologic treatments. However, MSCs and MSCs administered concurrently with PRP provide a reduced risk of reinjury. CLINICAL RELEVANCE: The current study identified a decrease in reinjury rate in horses administered MSCs or a combination of MSCs and PRP for tendinopathy and desmopathy. However, results should be interpreted with consideration of the heterogeneity of findings, poor study quality, and high risk of bias in the majority of studies.

Review of current and potential applications of mesenchymal stem cells in exotic animal species.

The discovery that a population of cells derived from adult tissues had regenerative properties and could be expanded and utilized therapeutically led to an abundance of research into the safety and efficacy of these cells for a variety of disease processes. Derived from tissues of mesenchymal origin, these cells were called mesenchymal stem cells or mesenchymal stromal cells (MSCs). MSCs were subsequently found to have a variety of anti-inflammatory, antimicrobial, and regenerative properties both in vitro and in vivo. These cells have been extensively studied and demonstrated to be effective in the treatment of autoimmune diseases, inflammatory diseases, infectious diseases, and other pathologic conditions. Multiple veterinary clinical trials have been performed for diseases such as osteoarthritis, soft tissue, and tendon injuries in addition to other inflammatory and infectious conditions. Exotic animal species can pose additional challenges to the treatment of common medical conditions such as osteoarthritis due to varying metabolism and tolerance to medications as well as potential difficulty to medicate or utilize other common forms of therapy such as physical therapy, laser, massage, and acupuncture. Current knowledge of MSC use in exotic species is limited, but there is a large potential for benefit to a variety of species utilizing this novel therapeutic tool. This review includes a brief overview of mechanisms and known applications of this therapy as well as current and potential applications of MSCs in exotic animal species.

Heterogeneity of mesenchymal stem cells as a limiting factor in their clinical application to inflammatory bowel disease in dogs and cats.

Inflammatory bowel disease (IBD) is a major subtype of chronic enteropathies in dogs and cats. Conventional drugs such as immunomodulatory medicines as glucocorticoids and/or other anti-inflammatory are mainly applied for treatment. However, these drugs are not always effective to maintain remission from IBD and are limited by unacceptable side effects. Hence, more effective and safe therapeutic options need to be developed. Mesenchymal stem cells (MSCs) are multipotent stem cells with a self-renewal capacity, and have immunomodulatory, anti-inflammatory, anti-fibrotic, and tissue repair properties. Therefore, the application of MSCs as an alternative therapy for IBD has great potential in veterinary medicine. The efficacy of adipose tissue-derived MSC (ADSC) therapy for IBD in dogs and cats has been reported, including numerous studies in animal models. However, treatment outcomes in clinical trials of human IBD patients have not been consistent with preclinical studies. MSC-based therapy for various diseases has received widespread attention, but various problems in such therapy remain, among which no consensus has been reached on the preparation and treatment procedures for MSCs, and cellular heterogeneity of MSCs may be an issue. This review describes the current status of ADSC therapy for canine and feline IBD and summarizes the cellular heterogeneity of canine ADSCs, to highlight the necessity for further reduction or elimination of MSCs heterogeneity and standardization of MSC-based therapies.

Targeted transcriptomic analysis of synovial tissues from horses with septic arthritis treated with immune-activated mesenchymal stromal cells reveals induction of T-cell response pathways.

OBJECTIVE: To investigate mechanistically the reported beneficial effects of immune-activated mesenchymal stromal cell (MSC) therapy to treat equine septic arthritis, leveraging Nanostring technology. ANIMALS: 8 Quarter Horses with induced tibiotarsal Staphylococcus aureus septic arthritis treated IA with either Toll-like receptor-3 agonist polyinosinic:polycytidylic acid-activated MSCs + vancomycin antimicrobials (TLR-MSC-VAN; n = 4) or antimicrobials (VAN; 4). METHODS: Synovial tissues were collected and fixed in neutral-buffered 10% formalin, and formalin-fixed paraffin-embedded synovial and osteochondral tissues were sequenced using a custom-designed 200-gene equine Nanostring nCounter immune panel to directly quantify expression of key immune and cartilage-related genes. Immunohistochemistry to detect CD3+ T cells was performed on synovial tissues to further quantify T-cell infiltration in TLR-MSC-VAN- versus VAN-treated joints. RESULTS: Comparison of synovial transcriptomes between groups revealed moderate changes in differential gene expression, with upregulated expression of 9 genes and downregulated expression of 17 genes with fold change ≥ 2 or ≤ -2 and a significant false discovery rate-adjusted P value of ≤ .05. The most upregulated genes in TLR-MSC-VAN-treated horses included those related to T-lymphocyte recruitment and function, while pathways related to innate immune activation and inflammation were significantly downregulated. Immunohistochemistry and quantitation of CD3+ T-cell infiltrates revealed a numerically greater infiltrate in synovial tissues of TLR-MSC-VAN-treated horses, which did not reach statistical significance in this small sample set (P = .20). CLINICAL RELEVANCE: Targeted transcriptomic analyses using an equine Nanostring immune and cartilage health panel provided new mechanistic insights into how innate and adaptive immune cells within synovial tissues respond to TLR-activated MSC treatment when used to treat septic arthritis.

Treatment of Naturally Occurring Tendon Disease with Allogeneic Multipotent Mesenchymal Stromal Cells: A Randomized, Controlled, Triple-Blinded Pilot Study in Horses.

The treatment of tendinopathies with multipotent mesenchymal stromal cells (MSCs) is a promising option in equine and human medicine. However, conclusive clinical evidence is lacking. The purpose of this study was to gain insight into clinical treatment efficacy and to identify suitable outcome measures for larger clinical studies. Fifteen horses with early naturally occurring tendon disease were assigned to intralesional treatment with allogeneic adipose-derived MSCs suspended in serum or with serum alone through block randomization (dosage adapted to lesion size). Clinicians and horse owners remained blinded to the treatment during 12 months (seven horses per group) and 18 months (seven MSC-group and five control-group horses) of follow-up including clinical examinations and diagnostic imaging. Clinical inflammation, lameness, and ultrasonography scores improved more over time in the MSC group. The lameness score difference significantly improved in the MSC group compared with the control group after 6 months. In the MSC group, five out of the seven horses were free of re-injuries and back to training until 12 and 18 months. In the control group, three out of the seven horses were free of re-injuries until 12 months. These results suggest that MSCs are effective for the treatment of early-phase tendon disease and provide a basis for a larger controlled study.

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. Additionally, the translation of MSC therapy to human tendon injury has remained poor. Recent evidence indicates that naïve MSC function can be enhanced through exogenous stimulation or manipulation of their environment. This stimulation or activation, herein termed MSC licensing, markedly alters MSC functions associated with immunomodulation, extracellular matrix remodeling, vascular development, bioactive factor production, and endogenous stromal/progenitor cell support. Additionally, a variety of licensing strategies has proven to influence MSC-secreted factors that have positively influenced outcome parameters in both in vitro and in vivo disease models separate from musculoskeletal tissues. Therefore, identifying the optimal licensing strategy for MSCs could ultimately provide an avenue for reliable and repeatable treatment of a broad range of tendon injuries of both veterinary and human clinical patients. This article details current evidence on the effects of licensed MSCs in both in vitro and in vivo disease models of different species and provides commentary on how those effector functions identified may be translated to the treatment of tendon injuries.

Use of Stem Cells for the Treatment of Musculoskeletal Injuries in Horses.

Mesenchymal stem cells (MSCs) are used as a regenerative therapy in horses for musculoskeletal injury since the late 1990s and in some regions are standard of care for certain injuries. Yet, there is no Food and Drug Administration-approved MSC therapeutic in the United States for horses. In humans, lack of regulatory approval in the United States has been caused by failure of late-phase clinical trials to demonstrate consistent efficacy, perhaps because of nonuniformity of MSC preparation and application techniques. This article discusses clinical evidence for musculoskeletal applications of MSCs in the horse and current challenges to marketing approval.

Amelioration of DSS-induced colitis in mice by TNF-α-stimulated mesenchymal stem cells derived from feline adipose tissue via COX-2/PGE2 activation.

BACKGROUND: Mesenchymal stem cells (MSCs) have been investigated as therapeutic agents for inflammatory bowel disease (IBD). Stimulation of MSCs with pro-inflammatory cytokines is an approach to enhance their immunomodulatory effects. However, further investigation is required to support their application in immune-mediated disorders and companion animals. OBJECTIVES: This study aimed to assess the therapeutic effect of tumor necrosis factor (TNF)-α-stimulated feline adipose tissue-derived MSCs (fAT-MSCs) in a dextran sulfate sodium (DSS)-induced colitis mouse model. METHODS: Colitis mice was made by drinking water with 3% DSS and fAT-MSCs were injected intraperitoneally. Colons were collected on day 10. The severity of the disease was evaluated and compared. Raw 264.7 cells were cultured with the conditioned medium to determine the mechanism, using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: TNF-α-stimulated fAT-MSCs more improved severity of DSS-induced colitis in disease activity, colon length, histologic score, and inflammatory cytokine. In sectionized colon tissues, the group comprising TNF-α-stimulated fAT-MSCs had higher proportion of CD11b+CD206+ macrophages than in the other groups. In vitro, TNF-α-stimulation increased cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) secretion from fAT-MSCs. The conditioned medium from TNF-α-stimulated fAT-MSCs enhanced the expression of interleukin-10 and arginase-1 in LPS-activated Raw 264.7 cells. CONCLUSIONS: These results represent that TNF-α-stimulated fat-mscs ameliorate the inflamed colon more effectively. Furthermore, we demonstrated that the effectiveness was interlinked with the COX-2/PGE2 pathway.

Comparison of allogeneic mesenchymal stem cells therapeutic potentials in rabbits' cartilage defects: Μacroscopic and histological outcomes.

Mesenchymal stem cells are safe and effective for treating joint injuries. However, the most suitable cell source remains controversial. This randomized controlled, double-blind study aimed to evaluate the potentials of rabbit allogeneic bone marrow- (BMSCs), adipose- (ASCs) and synovial membrane- (SDSCs) derived stem cells encapsulated in fibrin glue (FG) in vivo. The therapeutic properties of fibrin glue in critical-sized osteochondral defects (ODs) were also investigated. A 3 × 3 mm-sized OD was created in the femoral patellar groove on both knees of New Zealand rabbits, except from the left knees of the control group in which the OD was 2 × 3mm. The rabbits were randomly divided into four groups (right/left knee): 3 × 3 mm / 2 × 3 mm-sized OD control group, FG/FG with ASCs group, FG/FG with BMSCs group, FG/FG with SDSCs group. The International Cartilage Repair Society (ICRS) and the O'Driscoll scales were used to evaluate tissue characteristics after 12 weeks. FG promoted the production of reparative tissue with superior macroscopic features. Allogeneic MSCs combined with FG improved the macroscopic and histological scores more than the FG groups. The tissue in the SDSCs group was macroscopically and histologically better than the ASCs and BMSCs groups. The ICRS score differed among the SDSCs and the ASCs groups, while the empty critical-sized ODs were filled with inferior tissue compared to smaller ones. The preclinical feasibility of stem cells for OD regeneration in rabbits and the osteochondrogenic superiority of SDSCs was demonstrated. Additional tests and extended studies are required to reassure the long-term safety of these findings.

Canine amniotic membrane-derived mesenchymal stem cells ameliorate atopic dermatitis through regeneration and immunomodulation.

Mesenchymal stem cells (MSCs) are a promising tool for treating immune disorders. However, the immunomodulatory effects of canine MSCs compared with other commercialized biologics for treating immune disorders have not been well studied. In this study we investigated the characteristics and immunomodulatory effects of canine amnion membrane (cAM)-MSCs. We examined gene expression of immune modulation and T lymphocytes from activated canine peripheral blood mononuclear cell (PBMC) proliferation. As a result, we confirmed that cAM-MSCs upregulated immune modulation genes (TGF-ß1, IDO1 and PTGES2) and suppressed the proliferation capacity of T cells. Moreover, we confirmed the therapeutic effect of cAM-MSCs compared with oclacitinib (OCL), the most commonly used Janus kinase (JAK) inhibitor, as a treatment for canine atopic dermatitis (AD) using a mouse AD model. As a result, we confirmed that cAM-MSCs with PBS treatment groups (passage 4, 6 and 8) compared with PBS only (PBS) though scores of dermatologic signs, tissue pathologic changes and inflammatory cytokines were significantly reduced. In particular, cAM-MSCs were more effective than OCL in the recovery of wound dysfunction, regulation of mast cell activity and expression level of immune modulation protein. Interestingly, subcutaneous injection of cAM-MSCs induced weight recovery, but oral administration of oclacitinib induced weight loss as a side effect. In conclusion, this study suggests that cAM-MSCs can be developed as a safe canine treatment for atopic dermatitis without side effects through effective regeneration and immunomodulation.