Stem cell-derived exosome transplantation as a new cell-free therapy for liver regeneration
Stem cell transplantation has been used to treat some diseases with promising results. Stem cells stem cells can rescue injured tissues through various mechanisms, such as stimulation of growth factor secretion, activation of other/local stem cells, differentiation into specialized cells, and modulation of the immune system. However, stem cell transplantation also carries risks related to immune rejection as well as tumorigenesis. in recent years, more evidence has suggested that transplantation of stem cell-derived exosomes can induce effects similar to stem cell transplan- tation. Particularly, exosomes are less immunogenic than the parent cells due to their low content of membrane proteins. this review aims to summarize the characteristics of exosomes, including their physiological functions, and to highlight the therapeutic effects of exosome injection in hepatic regeneration.
ETV-2 activated proliferation of endothelial cells and attenuated acute hindlimb ischemia in mice
Ischemia is the reduction of blood flow to tissues by injury of blood vessels. Depending on the sites of tissues and grade of ischemia, ischemia can cause many serious complications. This study aimed to evaluate the effects of the E-twenty six (ETS) factor Ets variant 2 (ETV2) gene expression in angiogenesis and the effect of ETV2 gene therapy in a mouse model of hindlimb ischemia. The role of ETV2 on endothelial cell proliferation was evaluated in vitro. Knockdown of ETV2 expression was done using short hairpin RNA (shRNA) lentiviral viral particles. The ETV2 viral vector was injected into the skeletal muscles at the ligated and burned sites of the hindlimb and evaluated for its efficacy as a gene therapy modality for ischemia. Vascular regeneration in mice was indirectly evaluated by changes in mouse survival, necrotic grades of the leg, normal blood oxygen saturation level (SpO2), and blood flow by trypan blue injection assay. Preliminary data showed that ETV2 expression played a role in angiogenesis of endothelial cells. ETV2 overexpression could trigger and stimulate proliferation of skeletal endothelial cells. In vivo knockdown of ETV2 expression inhibited the auto-recovery of ischemic hindlimb, while overexpression of ETV2 helped to rescue leg loss and reduce necrosis, significantly improving angiogenesis in hindlimb ischemia. Our findings demonstrate that ETV2 gene therapy is a potentially effective modality for vascular regeneration.
Stem Cell Therapy for Avascular Femoral Head Necrosis: From Preclinical to Clinical Study
Avascular necrosis of the femoral head (AVNFH) is a condition involving low blood supply to the femoral head. Lacking blood, the femoral head degenerates. Although there are certain techniques to treat this disease, the treatment efficiency does not significantly improve the symptoms, especially in the late stage of AVNFH. Currently, AVNFH is treated with stem cells. Various sources of stem cells, such as bone marrow- and adipose tissue-derived stem cells, have been applied with promising results. This chapter reviews and summarizes some of the results of AVNFH treatment by stem cell transplantation from preclinical study to the clinic.
Adipose tissue derived stromal vascular fraction transplantation can recover spinal cord injury in mice
Introduction: Stem cell therapy is one of the most promising therapies for degenerative diseases and related injuries. Adipose tissue derived stem cells (ADSCs) exhibit some particular properties such as high production of paracrine factors. Indeed, ADSCs have been successfully used to treat diseases, including osteoarthritis, diabetic ulcer, etc. Methods: In this study, ADSCs were used to treat spinal cord injury (SCI) in a mouse model. Non-expanded ADSCs, from stromal vascular fractions (SVFs) isolated from both autologous and allogeneic adipose tissues, were injected into injured sites of mice at a specified dose. The SCI mouse model were generated by transection of spinal cord at vertebrae T8-T10. After 1 week of transection, mice exhibiting completed SCI were divided into 4 groups: group 1 was control (mice without any treatment), group 2 was placebo (mice treated with platelet rich plasma (PRP)), group 3 was allogeneic SVF transplantation (mice treated with allogeneic SVFs), and group 4 was autologous SVF transplantation (mice treated with autologous SVFs). For the treatment groups, mice were transplanted with 20 µL of activated PRP or/and with 10 6 cells of SVF (allogeneic or autologous) into the injured position through laminectomy. The recovery of SCI was evaluated by locomotor test, sensory test and sensory-motor test at 5 weeks after transplantation. The histology of the spinal cord also was checked after 5 weeks. Results: The results showed that in all groups with PRP injected with or without SVFs, the inflammation was efficiently controlled. The glial scar as well as myelin defragmentation were clearly reduced. However, a significant improvement of BBB score was only recorded in mice transplanted with autologous SVFs. Conclusion: The results of our study show that autologous SVF transplantation in combination with PRP can be a promising therapy for SCI.
Adipose tissue derived stromal vascular fraction transplantation can recover spinal cord injury in mice.
Autism spectrum disorders (ASDs) are complex neurodevelopmental disorders characterized by dysfunctions in social interactions, abnormal to absent verbal communication, restricted interests, and repetitive stereotypic verbal and non-verbal behaviors, influencing the ability to relate to and communicate. The core symptoms of ASDs entail the cognitive, emotional, and neuro-behavioural domains. Recent studies showed that ASDs closely relate to immune disorders. Some studies consider ASDs as autoimmune diseases. Stem cells, particularly mesenchymal stem cells (MSCs), have been used to treat a variety of autoimmune diseases. MSCs exhibit strong immune modulation both in vitro and in vivo. To date, about ten clinical trials have used MSCs to treat ASDs in different countries. Although some benefit from treatment have been observed, there is still controversy on the use of MSC transplantation for ASDs due to inadequate scientific evidence. This review aims to provide a concise summary of results related to ASD treatment by use of stem cell transplantation. Moreover, scientific rationale for the use of MSCs to treat ASDs will be presented.
Stem Cell Therapy for Autism.