An unfortunate emergence of a new virus SARS-CoV-2, causing a disease known as COVID-19, has spread all around the globe and has caused a pandemic. It primarily affects the respiratory tract and lungs in some cases causing severe organ damage and pneumonia due to overwhelming immune responses. Clinical reports show that the most commons symptoms are fever, dry cough, and shortness of breath, along with several other symptoms. It is thought that an immense cytokine dysregulation in COVID-19 patients is caused following the virus infection. Notably, if patients present with pre-existing specific comorbidities like diabetes or high blood pressure, rates of COVID-19 induced complications and deaths are escalated. Mesenchymal stem cell (MSC) therapy has been shown to alleviate pneumonia and acute respiratory syndrome (ARDS) symptoms, through their immunomodulatory activities in COVID-19 patients. Although more research studies and clinical trial results are needed to elucidate the exact mechanism by which MSCs provide relief to COVID-19 infected patients. Results from clinical trials are encouraging as patients treated with MSCs, regain lung functions and have restored levels of cytokines and trophic factors underscoring the fact that stem cell therapy can be, at least, a complementary therapy to alleviate sufferings in COVID-19 patients. This review discusses the possible therapeutic uses of MSCs for treating COVID-19. Graphical Abstract

Background: Normal skin pigmentation pattern is an extremely important component of the appearance of a person, as it can be a significant factor in the social context of any person. A condition known as vitiligo is caused by the death of melanocytes leading to pigmentation loss in the skin. This affects all races across the globe and sometimes leading to social avoidance as in some communities it is stigmatized. Although there are different pathobiological processes suspected because of the different underlying causes of vitiligo, autoimmunity and oxidative stress are suspected to be the most probable ones. Objective: In this review, we present an overview of the underlying mechanisms causing and developing the disease. Also, will be covered some of the most successful treatments along with the clinical applications of Mesenchymal Stem Cells (MSCs) as a comprehensive approach for treating this condition. Results: Autoreactive CD8+ T-cells are the primary suspect considered to be responsible for the destruction of melanocytes. Therefore, topical use of autoimmune inhibitors including those derived from MSCs, thanks to their immune-modulatory properties, have been reported to be successful in the promotion of repigmentation. MSCs can suppress the proliferation of CD8+T via the NKG2D pathway while inducing T-cell apoptosis. The use of pharmacological agents for reducing cellular oxidative stress with the help of topical application of antioxidants and growth factors also have been in use. Intravenous administration of MSCs has been shown to regulate the level of reactive oxidative species (ROS) in a mice model. Growth factors derived from platelet-rich-plasma (PRP) or from MSCs caused rapid tissue regeneration. Conclusions: Finally, MSC therapy also has been shown to stimulate the mobilization of healthy melanocytes, leading to successful repigmentation of skin lesions in vitiligo patients.

The primary diagnoses associated with their infertility included: diminished ovarian reserve (n¼9), male factor infertility (n¼3), endometriosis (n¼3), hypothalamic amenorrhea (n¼2), FSH receptor defect (n¼1), Grave's disease (n¼1), advanced maternal age (n¼1), unexplained infertility (n¼7), and PCOS (n¼17). Two patients were excluded due to insufficient RNA on endometrial biopsy. Chi-square analysis demonstrated patients with PCOS have a twofold (OR¼2.03; p¼0.29) increased likelihood of non-receptive endometrial lining by ERA analysis as compared to those without a diagnosis of PCOS.CONCLUSIONS: Though not statistically significant, the results of the study are clinically relevant as our investigation demonstrates that the odds of having non-receptive endometrial lining for patients with PCOS is at least two times that of patients who are not affected by PCOS. Further investigation on this subject is warranted as an early ERA may decrease the incidence of recurrent implantation failure in PCOS patients.IMPACT STATEMENT: Based on our findings, physicians may have a lower threshold to offer ERA to PCOS patients compared to other infertility diagnoses.

The development and complication of corneal ulcers (CU) in dogs has become a serious burden in pet health. Dogs with exaggerated juvenilelike craniofacial conformations, such as pug breed, are twenty times more prone to develop this condition. Although most of the cases are treated without surgical intervention, complicated and infected cases could lead to permanent blindness and other related complications. New approaches in treating this condition with mesenchymal stem cells (MSC) have been proposed with great results. Given their immunomodulation and regenerative properties, local administration of MSCs has proven to be safe and efficient in treating ocular related health conditions. This manuscript presents a complicated case of a canine CU treated with local infiltration of 1x10 6 canine dental pulp MSCs (cDMSCs). Stem cell therapy was performed at the Central Medica Veterinaria in Colima, Mexico with the consent of the owner, as it was hypothesized that the regenerative properties of MSCs could potentially alleviate the patient´s condition. Notorious improvement was reported after 12 hours of infiltration, and neovascularization process was observed within the next few days. The patient was discharged on the 29 th day of treatment, with minimal scar and fully regain normal vision.Therefore, using MSCs is a viable option for treating corneal ulcers in dogs.

Diabetes mellitus (DM) is a multifaceted pathological condition, which at present is being considered an epidemic disease keeping the rampant rate of its increase in almost all population groups of the world in consideration. Out of the two types of DM described, T1D is characterized as an autoimmune condition that leads to the destruction of pancreatic β-cells by macrophages and T-cells, thereby, adversely affecting the production of insulin. On the other hand, T2D, often caused by insulin resistance, is commonly related to unhealthy habits, and therefore, it can be prevented in most cases. In both of the conditions, high levels of proinflammatory cytokines like IL-6, TNF-α, and INF-ƴ, lead to chronic inflammation, and elevated oxidative stress resulting in apoptosis and destruction of tissues. Although several treatments are available to treat the symptoms, the underlying causes are not well addressed. One of the most promising approaches to tackle the ill effects and the primary causes of DM is mesenchymal stem cell (MSC) therapy. The use of MSC therapy, because of the immunomodulatory and regenerative properties recorded in this type of cells in a number of experiments carried out in animal models and clinical trials of the disease, has reported positive outcomes. This review covers the principal mechanisms of action induced during MSC therapy in reference to the described pathophysiological pathways of both T1D and T2D. In addition, how this therapeutic intervention can counteract the ill effects of this condition leading to the promotion of tissue regeneration has been covered.