Stem Cell Therapy

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.

Mesenchymal Stem Cell-Based Therapy as a New Approach for the Treatment of Systemic Sclerosis

Systemic sclerosis (SSc) is an intractable autoimmune disease with unmet medical needs. Conventional immunosuppressive therapies have modest efficacy and obvious side effects. Targeted therapies with small molecules and antibodies remain under investigation in small pilot studies. The major breakthrough was the development of autologous haematopoietic stem cell transplantation (AHSCT) to treat refractory SSc with rapidly progressive internal organ involvement. However, AHSCT is contraindicated in patients with advanced visceral involvement. Mesenchymal stem cells (MSCs) which are characterized by immunosuppressive, antifibrotic and proangiogenic capabilities may be a promising alternative option for the treatment of SSc. Multiple preclinical and clinical studies on the use of MSCs to treat SSc are underway. However, there are several unresolved limitations and safety concerns of MSC transplantation, such as immune rejections and risks of tumour formation, respectively. Since the major therapeutic potential of MSCs has been ascribed to their paracrine signalling, the use of MSC-derived extracellular vesicles (EVs)/secretomes/exosomes as a "cell-free" therapy might be an alternative option to circumvent the limitations of MSC-based therapies. In the present review, we overview the current knowledge regarding the therapeutic efficacy of MSCs in SSc, focusing on progresses reported in preclinical and clinical studies using MSCs, as well as challenges and future directions of MSC transplantation as a treatment option for patients with SSc.

Clinical application of mesenchymal stem cells therapy in musculoskeletal injuries in dogs-a review of the scientific literature

Mesenchymal stem cells (MSCs) are multipotent, which is defined by their ability to self-renew while maintaining the capacity to differentiate into a certain number of cells, presumably from their own germinal layer. MSCs therapy is based on their anti-inflammatory, immunomodulatory (immunosuppressive), and regenerative potential. This review aims to provide a clinical overview of the MSCs potential as a therapeutic option for orthopedic diseases in dogs. A total of 25 clinical studies published in the scientific literature in the last 15 years on various diseases will be presented: semitendinosus myopathy, supraspinatus tendinopathy, cruciate ligament rupture, bone fractures and defects, and also osteoarthritis (OA). All articles involved in this study include only diseases that have naturally occurred in canine patients. MSCs therapy in the veterinary orthopedic field has great potential, especially for OA. All studies presented promising results. However, MSCs bone healing capacity did not reveal such favorable outcomes in the long term. Besides, most of these clinical studies did not include immunohistochemistry, immunofluorescence, and histopathology to confirm that MSCs have differentiated and incorporated into the injured tissues. This review summarizes the current knowledge of canine MSCs biology, immunology, and clinical application in canine orthopedic diseases. Despite the positive results in its use, there is still a lack of defined protocols, heterogeneous samples, and concomitant medications used with MSCs therapy compromising therapeutic effects. Further studies are needed in the hope of overcoming its limitation in upcoming trials.

Immortalized canine adipose-derived mesenchymal stem cells alleviate gentamicin-induced acute kidney injury by inhibiting endoplasmic reticulum stress in mice and dogs

Adipose-derived mesenchymal stem cells have been used to treat acute kidney injury (AKI). The role of endoplasmic reticulum (ER) stress in AKI treatment with canine adipose-derived mesenchymal stem cells (cADSCs) remains unknown. This study intended to investigate the therapeutic effects of cADSCs cultured in different media on AKI in mice and dogs and reveal the role of ER stress in this process. The mice were divided into two branches: a control group and a gentamicin induced group (this group treated with low-serum ADSC or high-serum ADSC or 4-phenylbutyric acid (4-PBA)). The dogs were divided into control, model, and cell-injected groups. To suppress ER stress, mice were simultaneously treated with 4-PBA. The results showed there were improvements in renal function and tissue damage and a corresponding decrease in ER stress in the kidneys of the mice that received cell injection. However, the cells cultured with 2% FBS showed a better growth state and resulted in lower ER stress levels in treated kidneys. In the 4-PBA-treated group, ER stress was suppressed, and there was corresponding kidney injury recovery. Similarly, both kidney damage and ER stress were alleviated after AKI dogs were injected with the cells. Our findings reveal that both allogeneic and xenogeneic cADSCs were effective treatments for AKI by inhibiting ER stress. These results also provide evidence for a new clinical therapy for acute renal disease in pets.