Exosomes from Bone Marrow Mesenchymal Stem Cells Inhibit Neuronal Apoptosis and Promote Motor Function Recovery via the Wnt/β-catenin Signaling Pathway

Mesenchymal Stromal Cells Perspective: New Potential Therapeutic for the Treatment of Neurological Diseases

Several studies have shown that mesenchymal stromal/stem cells (MSCs) exert their neuroprotective and neurorestorative efficacy via the secretion of neurotrophic factors. Based on these studies, many clinical trials using MSCs for the treatment of neurological disorders have been conducted, and results regarding their feasibility and efficacy have been reported. The present review aims to highlight the characteristics and basic research regarding the role of MSCs in neurological disease and to discuss the recent progress in clinical trials using MSCs to treat various neurological disorders.

Spinal Cord Repair: From Cells and Tissue Engineering to Extracellular Vesicles

Spinal cord injury (SCI) is a debilitating condition, often leading to severe motor, sensory, or autonomic nervous dysfunction. As the holy grail of regenerative medicine, promoting spinal cord tissue regeneration and functional recovery are the fundamental goals. Yet, effective regeneration of injured spinal cord tissues and promotion of functional recovery remain unmet clinical challenges, largely due to the complex pathophysiology of the condition. The transplantation of various cells, either alone or in combination with three-dimensional matrices, has been intensively investigated in preclinical SCI models and clinical trials, holding translational promise. More recently, a new paradigm shift has emerged from cell therapy towards extracellular vesicles as an exciting "cell-free" therapeutic modality. The current review recapitulates recent advances, challenges, and future perspectives of cell-based spinal cord tissue engineering and regeneration strategies.

Bie Jia Jian pill enhances the amelioration of bone mesenchymal stem cells on hepatocellular carcinoma progression

Background

The therapeutic efficiency of Traditional Chinese Medicine (TCM) in suppressing the recurrence and metastasis of hepatocellular carcinoma (HCC) has been well proved.

Objective

The aim of this study is to investigate the role of Bie Jia Jian pill (BJJP) combined with bone mesenchymal stem cells (BMSCs) in HCC progression.

Methods

Flow cytometry was used to identify BMSCs isolated from BALB/c mice. The expressions of biomarkers and apoptosis rate of cancer stem cells (CSCs) enriched from Huh7 cells were also measured. The osteogenic differentiation and adipogenic differentiation ability of isolated BMSCs was determined by oil red O staining and Alizarin Red Staining. CSCs were used to establish the orthotopic HCC model. Histological changes in the liver tissues were examined by hematoxylin–eosin (H&E) staining and Van Gieson (VG) staining. The cell apoptotic rate in the cancer tissues was detected by TUNEL staining. The cell proliferation antigen Ki67 in the cancer tissues were detected by immunofluorescence assay and PCR, respectively. The levels of CSCs cellular surface markers (CD24, CD133 and EpCAM) and Wnt/β-catenin signal pathway related proteins were detected by PCR and western blot.

Results

Treatment of BJJP or BMSCs both improved the morphology induced by HCC and suppressed the differentiation ability of CSCs, as evidenced by down-regulated expressions of CD24, CD133, EpCAM and Ki67. The protective effect of BJJP or BMSCs in cancer tissues can be enhanced by the combination of BJJP and BMSCs. In addition to that, BJJP or BMSCs alone was found to increase the expression of miR-140 and promote cell apoptosis in CSCs, while down-regulation of miR-140 partially reversed the protective effect of BMSCs or BJJP + BMSCs on cancer tissues. BJJP + BMSCs treatment together also can down-regulate the expressions of Wnt3a and β-catenin.

Conclusions

These results proved the inhibitory role of BJJP + BMSCs in HCC development through regulating miR-140 and Wnt/β-catenin signal pathway.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11418-021-01548-4.

Increased endothelial sodium channel activity by extracellular vesicles in human aortic endothelial cells: Putative role of MLP1 and bioactive lipids

Extracellular vesicles (EVs) contain biological molecules and are secreted by cells into the extracellular milieu. The endothelial sodium channel (EnNaC) plays an important role in modulating endothelial cell stiffness. We hypothesized EVs secreted from human aortic endothelial cells (hAoEC) positively regulate EnNaC in an autocrine dependent manner. A comprehensive lipidomic analysis using targeted mass spectrometry was performed on multiple preparations of EVs isolated from the conditioned media of hAoEC or complete growth media of these cells. Cultured hAoEC challenged with EVs isolated from the conditioned media of these cells resulted in an increase in EnNaC activity when compared to the same concentration of media derived EVs or vehicle alone. EVs isolated from the conditioned media of hAoEC but not human fibroblast cells were enriched in MARCKS Like Protein 1 (MLP1). The pharmacological inhibition of the negative regulator of MLP1, protein kinase C, in cultured hAoEC resulted in an increase in EV size and release compared to vehicle or pharmacological inhibition of protein kinase D. The MLP1 enriched EVs increased the density of actin filaments in cultured hAoEC compared to EVs isolated from human fibroblast cells lacking MLP1. We quantified 141 lipids from glycerolipids, glycerophospholipids, and sphingolipids in conditioned media EVs that represented twice the number found in control media EVs. The concentrations of sphingomyelin, lysophosphatidylcholine and phosphatidylethanolamine were higher in conditioned media EVs. These results provide the first evidence for EnNaC regulation in hAoEC by EVs and provide insight into a possible mechanism involving MLP1, unsaturated lipids, and bioactive lipids.

A meta-analysis of exosome in the treatment of spinal cord injury

Context

There are no recommended therapeutic agents for acute spinal cord injury (SCI) due to the pathophysiological complexity of the injury.

Objective

The objective of this study is to investigate the efficacy of various exosomes and potential factors impacting the efficacy of exosomes.

Methods

We searched the PubMed, EMBASE, Web of Science, Medline, Scopus, and Cochrane Library databases to systematically collect articles comparing the locomotor function of SCI rodents undergoing exosome treatment and untreated SCI rodents. No language was preferred.

Results

Pooled analysis revealed that the locomotor function recovery of SCI rodents receiving exosomes was greatly improved (583 rats, 3.12, 95% CI: 2.56–3.67, p < 0.01; 116 mice, 2.46, 95% CI: 1.20–3.72, p < 0.01) compared to those of control rodents. The trial sequential analysis demonstrated the findings of the meta-analysis with the cumulative Z-curve crossing the upper monitoring boundary for the benefit and reaching the adjusted required information size. However, the origin of the exosome, SCI model, and administration method determined the therapeutic effect to some extent.

Conclusions

Despite the proven therapeutic effects of exosomes on SCI rodents, the results should be interpreted cautiously considering the diversity in vivo and in vitro in relation to future trials.

Emerging Exosomes and Exosomal MiRNAs in Spinal Cord Injury

Acute spinal cord injury (SCI) is a serious traumatic event to the spinal cord with considerable morbidity and mortality. This injury leads to short- and long-term variations in the spinal cord, and can have a serious effect on the patient's sensory, motor, or autonomic functions. Due to the complicated pathological process of SCI, there is currently no successful clinical treatment strategy. Exosomes, extracellular vesicles (EVs) with a double-layer membrane structure of 30-150 nm diameter, have recently been considered as critical mediators for communication between cells and tissues by transferring proteins, lipids, and nucleic acids. Further studies verified that exosomes participate in the pathophysiological process of several diseases, including cancer, neurodegenerative diseases, and cardiovascular diseases, and could have a significant impact in their treatment. As natural carriers of biologically active cargos, exosomes have emerged as pathological mediators of SCI. In this review article, we critically discuss the functions of exosomes as intracellular mediators and potential treatments in SCI and provide an outlook on future research.

The Potential Role of Inflammation in Modulating Endogenous Hippocampal Neurogenesis After Spinal Cord Injury

Currently there are approximately 291,000 people suffering from a spinal cord injury (SCI) in the United States. SCI is associated with traumatic changes in mobility and neuralgia, as well as many other long-term chronic health complications, including metabolic disorders, diabetes mellitus, non-alcoholic steatohepatitis, osteoporosis, and elevated inflammatory markers. Due to medical advances, patients with SCI survive much longer than previously. This increase in life expectancy exposes them to novel neurological complications such as memory loss, cognitive decline, depression, and Alzheimer's disease. In fact, these usually age-associated disorders are more prevalent in people living with SCI. A common factor of these disorders is the reduction in hippocampal neurogenesis. Inflammation, which is elevated after SCI, plays a major role in modulating hippocampal neurogenesis. While there is no clear consensus on the mechanism of the decline in hippocampal neurogenesis and cognition after SCI, we will examine in this review how SCI-induced inflammation could modulate hippocampal neurogenesis and provoke age-associated neurological disorders. Thereafter, we will discuss possible therapeutic options which may mitigate the influence of SCI associated complications on hippocampal neurogenesis.

Stem cell-derived exosomes as a cell free therapy against spinal cord injury

Recent evidence suggests that stem cell therapy has beneficial effects on spinal cord injury. It was subsequently established that these beneficial effects may be mediated through release of paracrine factors, a kind of extracellular vesicle known as exosomes. Stem cell-secreted nano-sized exosomes have shown great potential to reduce apoptosis and inflammation, enhance angiogenesis, and improve functional behavioral recovery following spinal cord injury. This review summarizes current knowledge about the influence of exosomes derived from stem cells on spinal cord protection and regeneration with their molecular mechanisms after injury.

Mesenchymal stem cells: Biological characteristics and application in disease therapy

Mesenchymal stem cells (MSCs) are multipotent stem cells. In addition to the capacity for self-renewal and multipotential differentiation, MSCs also have the following characteristics. MSCs can exert immunomodulatory functions through interaction with innate or adaptive immune cells, MSCs with poor immunogenicity can be used for allogeneic transplantation, and MSCs can "home" to inflammation and tumour sites. Based on these biological properties, MSCs demonstrate broad clinical application prospects in the treatment of tissue injury, autoimmune diseases, transplantation, cancer and other inflammation-related diseases. In this review we describe the biological characteristics of MSCs and discuss the research advances of MSCs in regenerative medicine, immunomodulation, oncology, and COVID-19, to fully understand the range of diseases in which MSC therapy may be beneficial.

MRI tracking/detection of bone marrow mesenchymal stromal cells transplantation for treatment of ischemic cerebral infarction

Background

Cerebral stroke is the second leading cause of death with high mortality and morbidity worldwide, currently it lacks effective therapies to improve the prognosis. This study was aimed to explore the role of bone marrow mesenchymal stem cells (BMSCs) transplantation in the recovery of brain structure and function after ischemic cerebral infarction by magnetic resonance imaging (MRI).

Methods

By applying internal carotid artery embolization, the ischemic cerebral infarction model in rats was established. MRI was performed to detect the imaging changes in the brain tissue after modeling, and the successful modeling was evidenced by the presence of obvious high-signal infarct areas in the brain. BMSCs were then injected into the lateral ventricles of rats, and the recovery of brain tissue and function were quantitatively evaluated by T2-weighted image (T2WI) and voxel-based morphology (VBM) after 28 days.

Results

The results showed that BMSCs were cell subsets with multiple differentiation potentials. Deficits caused by Ischemic cerebral infarction were relieved by BMSCs transplantation, including increase in damaged cerebral tissue and recovery of cerebral function. In addition, the combined imaging technology of VBM and T2WI quantitatively revealed the effectiveness of BMSCs in repairing damaged brain tissue structure and function.

Conclusion

Taken together, the results revealed that the transplantation of BMSCs into the lateral ventricle was beneficial to repair the structure and function of the damaged brain tissue after ischemic cerebral infarction. Moreover, the combination of VBM and T2WI technology can detect the level of brain injury in ischemic cerebral infarction dynamically and noninvasively, and evaluate the recovery of structure and function of damaged brain tissue.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: Regenerative Potential and Challenges

Evidence suggests that stem cells exert regenerative potential via the release of extracellular vesicles. Mesenchymal stem cell extracellular vesicles (MSCEVs) offer therapeutic benefits for various pathophysiological ailments by restoring tissues. Facts suggest that MSCEV action can be potentiated by modifying the mesenchymal stem cells culturing methodology and bioengineering EVs. Limited clinical trials of MSCEVs have questioned their superiority, culturing quality, production scale-up and isolation, and administration format. Translation of preclinically successful MSCEVs into a clinical platform requires paying attention to several critical matters, such as the production technique, quantification/characterization, pharmacokinetics/targeting/transfer to the target site, and the safety profile. Keeping these issues as a priority, the present review was designed to highlight the challenges in translating preclinical MSCEV research into clinical platforms and provide evidence for the regenerative potential of MSCEVs in various conditions of the liver, kidney, heart, nervous system, bone, muscle, cartilage, and other organs/tissues.

Extracellular Vesicles: Novel Roles in Neurological Disorders

Exosomes are small extracellular vesicles (EVs) secreted by almost all cells, which have been recognized as a novel platform for intercellular communication in the central nervous system (CNS). Exosomes are capable of transferring proteins, nucleic acids, lipids, and metabolites between neurons and glial cells, contributing to CNS development and maintenance of homeostasis. Evidence shows that exosomes originating from CNS cells act as suppressors or promoters in the initiation and progression of neurological disorders. Moreover, these exosomes have been shown to transfer molecules associated with diseases through the blood-brain barrier (BBB) and thus can be detected in blood. This unique feature enables exosomes to act as potential diagnostic biomarkers for neurological disorders. In addition, a substantial number of researches have indicated that exosomes derived from mesenchymal stem cells (MSCs) have repair effects on neurological disorders. Herein, we briefly introduce the roles of exosomes under physiological and pathological conditions. In particular, novel roles of exosomes as potential diagnostic biomarkers and therapeutic tools for neurological disorders are highlighted.

Mesenchymal stem cell-derived exosomes: therapeutic opportunities and challenges for spinal cord injury

Spinal cord injury (SCI) often leads to serious motor and sensory dysfunction of the limbs below the injured segment. SCI not only results in physical and psychological harm to patients but can also cause a huge economic burden on their families and society. As there is no effective treatment method, the prevention, treatment, and rehabilitation of patients with SCI have become urgent problems to be solved. In recent years, mesenchymal stem cells (MSCs) have attracted more attention in the treatment of SCI. Although MSC therapy can reduce injured volume and promote axonal regeneration, its application is limited by tumorigenicity, a low survival rate, and immune rejection. Accumulating literature shows that exosomes have great potential in the treatment of SCI. In this review, we summarize the existing MSC-derived exosome studies on SCI and discuss the advantages and challenges of treating SCI based on exosomes derived from MSCs.

Preclinical Experimental Applications of miRNA Loaded BMSC Extracellular Vesicles

Bone marrow mesenchymal stem cells have been investigated for many years, especially for tissue regeneration, and have inherent limitations. One of the rapidly developing fields in the scientific world in recent years is extracellular vesicles. Especially, bone marrow mesenchymal stem cell originated extracellular vesicles are known to have positive contributions in tissue regeneration, and these extracellular vesicles have also been used as gene transfer systems for cellular therapy. Through gene expression analysis and bioinformatics tools, it is possible to determine which genes have changed in the targeted tissue or cell and which miRNAs that can correct this gene expression disorder. This approach connecting the stem cell, extracellular vesicles, epigenetics regulation and bioinformatics fields is one of the promising areas for the treatment of diseases in the future. With this review, it is aimed to present the studies carried out for the use of bone marrow stem cell-derived extracellular vesicles loaded with targeted miRNAs in different in vivo and in vitro human disease models and to discuss recent developments in this field.

The Chemokine Receptors Ccr5 and Cxcr6 Enhance Migration of Mesenchymal Stem Cells into the Degenerating Retina

Cell therapy approaches hold great potential for treating retinopathies, which are currently incurable. This study addresses the problem of inadequate migration and integration of transplanted cells into the host retina. To this end, we have identified the chemokines that were most upregulated during retinal degeneration and that could chemoattract mesenchymal stem cells (MSCs). The results were observed using a pharmacological model of ganglion/amacrine cell degeneration and a genetic model of retinitis pigmentosa, from both mice and human retinae. Remarkably, MSCs overexpressing Ccr5 and Cxcr6, which are receptors bound by a subset of the identified chemokines, displayed improved migration after transplantation in the degenerating retina. They also led to enhanced rescue of cell death and to preservation of electrophysiological function. Overall, we show that chemokines released from the degenerating retinae can drive migration of transplanted stem cells, and that overexpression of chemokine receptors can improve cell therapy-based regenerative approaches.

Stem Cell-Derived Exosomes and Nanovesicles: Promotion of Cell Proliferation, Migration, and Anti-Senescence for Treatment of Wound Damage and Skin Ageing

Extracellular vesicles (EVs), such as exosomes, are nano-sized vesicles derived from endocytic membranes and contain biomolecules such as proteins, lipids, RNAs, and DNAs for the transfer of signals to recipient cells, playing significant roles in cell-to-cell communication. Discovery of exosomes has attracted attention for possible use as next generation therapies in clinical applications; however, several studies suggest that cells secrete exosomes that perform as mediators in the tumor niche and play several roles in tumorigenesis, angiogenesis, and metastasis. Recently, stem cell-derived exosomes have been suggested as a desirable source for regenerative medicine due to their roles in the promotion of angiogenesis via migratory and proliferative mechanisms. This review is aimed at demonstrating the present knowledge of stem cell-derived exosomes and cell-engineered nanovesicles (CNVs) as proliferative, migratory, and anti-senescent therapeutic biomaterial for use in tissue regeneration; wound healing and anti-ageing are explained. We conclude this review by discussing the future perspectives of stem cell-derived exosomes and CNVs as a platform in therapeutic strategies for treatment of wound damage and skin aging.

Caspase-3 Cleaves Extracellular Vesicle Proteins During Auditory Brainstem Development

Sound localization requires extremely precise development of auditory brainstem circuits, the molecular mechanisms of which are largely unknown. We previously demonstrated a novel requirement for non-apoptotic activity of the protease caspase-3 in chick auditory brainstem development. Here, we used mass spectrometry to identify proteolytic substrates of caspase-3 during chick auditory brainstem development. These auditory brainstem caspase-3 substrates were enriched for proteins previously shown to be cleaved by caspase-3, especially in non-apoptotic contexts. Functional annotation analysis revealed that our caspase-3 substrates were also enriched for proteins associated with several protein categories, including proteins found in extracellular vesicles (EVs), membrane-bound nanoparticles that function in intercellular communication. The proteome of EVs isolated from the auditory brainstem was highly enriched for our caspase-3 substrates. Additionally, we identified two caspase-3 substrates with known functions in axon guidance, namely Neural Cell Adhesion Molecule (NCAM) and Neuronal-glial Cell Adhesion Molecule (Ng-CAM), that were found in auditory brainstem EVs and expressed in the auditory pathway alongside cleaved caspase-3. Taken together, these data suggest a novel developmental mechanism whereby caspase-3 influences auditory brainstem circuit formation through the proteolytic cleavage of extracellular vesicle (EV) proteins.

Mesenchymal Stem Cell-Derived Exosomes: Hope for Spinal Cord Injury Repair

Spinal cord injury (SCI) is a devastating medical condition with profound social and economic impacts. Although research is ongoing, current treatment options are limited and do little to restore functionality. However, recent studies suggest that mesenchymal stem cell-derived exosomes (MSC-exosomes) may hold the key to exciting new treatment options for SCI patients. MSCs are self-renewing multipotent stem cells with multi-directional differentiation and can secrete a large number of exosomes (vesicles secreted into the extracellular environment through endocytosis, called MSC-exosomes). These MSC-exosomes play a critical role in repairing SCI through promoting angiogenesis and axonal growth, regulating inflammation and the immune response, inhibiting apoptosis, and maintaining the integrity of the blood-spinal cord barrier. Furthermore, they can be utilized to transport genetic material or drugs to target cells, and their relatively small size makes them able to permeate the blood-brain barrier. In this review, we summarize recent advances in MSC-exosome themed SCI treatments and cell-free therapies to better understand this newly emerging methodology.

Molecular Mechanism and Approach in Progression of Meningioma

Meningioma is the most common tumor of the central nervous system, most of which is benign. Even after complete resection, a high rate of recurrence of meningioma is observed. From in-depth study of its pathogenesis, it has been found that a number of chromosomal variations and abnormal molecular signals are closely related to the occurrence and development of malignancy in meningioma, which may provide the theoretical basis and potential direction for accurate and targeted treatment. We have reviewed advances in chromosomal variations and molecular mechanisms involved in the progression of meningioma, and have highlighted the association with malignant biological behavior including cell proliferation, angiogenesis, increased invasiveness, and inhibition of apoptosis. In addition, the chemotherapy of meningioma is summarized and discussed.

Mesenchymal stem cell-derived exosomes: Toward cell-free therapeutic strategies in regenerative medicine

Mesenchymal stem cells (MSCs) are multipotent stem cells with marked potential for regenerative medicine because of their strong immunosuppressive and regenerative abilities. The therapeutic effects of MSCs are based in part on their secretion of biologically active factors in extracellular vesicles known as exosomes. Exosomes have a diameter of 30-100 nm and mediate intercellular communication and material exchange. MSC-derived exosomes (MSC-Exos) have potential for cell-free therapy for diseases of, for instance, the kidney, liver, heart, nervous system, and musculoskeletal system. Hence, MSC-Exos are an alternative to MSC-based therapy for regenerative medicine. We review MSC-Exos and their therapeutic potential for a variety of diseases and injuries.

Exosomes Derived from MicroRNA-146a-5p-Enriched Bone Marrow Mesenchymal Stem Cells Alleviate Intracerebral Hemorrhage by Inhibiting Neuronal Apoptosis and Microglial M1 Polarization

Introduction

Intracerebral hemorrhage (ICH) is a devastating type of stroke with high mortality, and the effective therapies for ICH remain to be explored. Exosomes (Exos) have been found to play important roles in cell communication by transferring molecules, including microRNAs (miRNAs/miRs). MiRNAs are critical regulators of genes involved in many various biological processes and have been demonstrated to aggravate or alleviate brain damages induced by ICH. The aim of the present study was to investigate the effect of Exos derived from miR-146a-5p-enriched bone marrow mesenchymal stem cells (BMSCs-miR-146a-5p-Exos) on experimental ICH.

Methods

ICH was induced in adult male Sprague-Dawley rats by an intrastriatal injection of collagenase type IV. At 24 h after surgery, Exos were administrated. For detecting apoptotic cells, TUNEL staining was performed using an in situ Cell Death Detection Kit. Fluoro-Jade B staining was performed to detect degenerating neurons. Immunofluorescence assay was performed to detect the expression of myeloperoxidase (MPO) and OX-42. The binding of miR-146a-5p and its target genes was confirmed by luciferase reporter assay.

Results

At 24 h after surgery, BMSCs-miR-146a-5p-Exos administration significantly improved neurological function, reduced apoptotic and degenerative neurons, and inhibited inflammatory response. Furthermore, miR-146a-5p-enriched Exos obviously inhibited the M1 polarization of microglia after ICH in rats, accompanied by the reduced expression of pro-inflammatory mediators releasing by M1 microglia including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and monocyte chemoattractant protein-1 (MCP-1). Finally, we observed that miR-146a-5p directly targeted interleukin-1 receptor-associated kinase1 (IRAK1) and nuclear factor of activated T cells 5 (NFAT5), which contributed to the inflammation response and the polarization of M1 microglia/macrophages.

Conclusion

We demonstrated that miR-146a-5p-riched BMSCs-Exos could offer neuroprotection and functional improvements after ICH through reducing neuronal apoptosis, and inflammation associated with the inhibition of microglial M1 polarization by downregulating the expression of IRAK1 and NFAT5.

Stem Cell Conditioned Medium Treatment for Canine Spinal Cord Injury: Pilot Feasibility Study

Spinal cord injury (SCI) involves nerve damage and often leads to motor, sensory and autonomic dysfunctions. In the present study, we have designed a clinical protocol to assess the feasibility of systemic delivery of allogenic canine bone marrow tissue-derived mesenchymal stem cell conditioned medium (BMMSC CM) to dogs with SCI. Four client-owned dogs with chronic SCI lasting more than six months underwent neurological and clinical evaluation, MRI imaging and blood tests before being enrolled in this study. All dogs received four intravenous infusions with canine allogenic BMMSC CM within one month. Between the infusions the dogs received comprehensive physiotherapy, which continued for three additional months. No adverse effects or complications were observed during the one, three and six months follow-up periods. Neither blood chemistry panel nor hematology profile showed any significant changes. All dogs were clinically improved as assessed using Olby locomotor scales after one, three and six months of BMMSC CM treatment. Furthermore, goniometric measurements revealed partial improvement in the range of joint motion. Bladder function improved in two disabled dogs. We conclude that multiple delivery of allogenic cell-derived conditioned medium to dogs with chronic SCI is feasible, and it might be clinically beneficial in combination with physiotherapy.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Attenuate LPS-Induced ARDS by Modulating Macrophage Polarization Through Inhibiting Glycolysis in Macrophages

Macrophages play a key role in the development of sepsis-induced acute respiratory distress syndrome (ARDS). Recent evidence has proved that glycolysis plays an important role in regulating macrophage polarization through metabolic reprogramming. Bone marrow mesenchymal stem cells (BMSCs) can alleviate sepsis-induced lung injury and possess potent immunomodulatory and immunosuppressive properties via secreting exosomes. However, it is unknown whether BMSCs-derived exosomes exert their therapeutic effect against sepsis-induced lung injury by inhibiting glycolysis in macrophages. Therefore, the present study aimed to evaluate the anti-inflammatory effects of exosomes released from BMSCs on acute lung injury induced by lipopolysaccharide (LPS) in mice and explored the possible underlying mechanisms in vitro and in vivo. We found that BMSCs inhibited M1 polarization and promoted M2 polarization in MH-S cells (a murine alveolar macrophage cell line) by releasing exosomes. Further experiments showed that exosomes secreted by BMSCs modulated LPS-treated MH-S cells polarization by inhibiting cellular glycolysis. Moreover, our results showed that BMSCs-derived exosomes down-regulated the expression of several essential proteins of glycolysis via inhibition of hypoxia-inducible factor 1 (HIF-1)α. Finally, a model of LPS-induced ARDS in mice was established, we found that BMSCs-derived exosomes ameliorated the LPS-induced inflammation and lung pathological damage. Meanwhile, we found that intratracheal delivery of BMSCs-derived exosomes effectively down-regulated LPS-induced glycolysis in mice lung tissue. These findings reveal new mechanisms of BMSCs-derived exosomes in regulating macrophage polarization which may provide novel strategies for the prevention and treatment of LPS-induced ARDS.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Improves Spinal Cord Function After Injury in Rats by Activating Autophagy

Background

Spinal cord injury (SCI) is a global medical problem. The smallest membrane-bound nanovesicles, known as exosomes, have a role in complex intercellular communication systems and can be used directly as therapeutic agents by acting as important paracrine factors. Nevertheless, the use of exosomes derived from BMSCs (BMSC-Exos) to treat SCI has been less, and the specific mechanism has not yet been reported.

Methods

BMSC-Exos were characterized by TEM, NTA and Western blot. The effects of BMSC-Exos treatment were compared by SCI in vivo model and a series of in vitro experiments.

Results

BMSC-Exos were found to enhance the expression of autophagy-related proteins LC3IIB and Beclin-1 and enabled autophagosomes formation. After BMSC-Exos treatment, there was marked decline in the level of expression of proapoptotic protein cleaved caspase-3, while that of the antiapoptotic protein Bcl-2 was upregulated.

Conclusion

BMSC-Exos can attenuate neuronal apoptosis by promoting autophagy and promote the potential efficacy of functional behavior recovery in SCI rats. In summary, these findings expand the theoretical knowledge and forms a realistic route for the future treatment of SCI by BMSC-Exos.

Mesenchymal Stem Cell Derived Extracellular Vesicles for Tissue Engineering and Regenerative Medicine Applications

Mesenchymal stem cells (MSCs) are being extensively investigated for their potential in tissue engineering and regenerative medicine. However, recent evidence suggests that the beneficial effects of MSCs may be manifest by their released extracellular vesicles (EVs); typically not requiring the administration of MSCs. This evidence, predominantly from pre-clinical in vitro and in vivo studies, suggests that MSC-EVs may exhibit substantial therapeutic properties in many pathophysiological conditions, potentially restoring an extensive range of damaged or diseased tissues and organs. These benefits of MSC EVs are apparently found, regardless of the anatomical or body fluid origin of the MSCs (and include e.g., bone marrow, adipose tissue, umbilical cord, urine, etc). Furthermore, early indications suggest that the favourable effects of MSC-EVs could be further enhanced by modifying the way in which the donor MSCs are cultured (for example, in hypoxic compared to normoxic conditions, in 3D compared to 2D culture formats) and/or if the EVs are subsequently bio-engineered (for example, loaded with specific cargo). So far, few human clinical trials of MSC-EVs have been conducted and questions remain unanswered on whether the heterogeneous population of EVs is beneficial or some specific sub-populations, how best we can culture and scale-up MSC-EV production and isolation for clinical utility, and in what format they should be administered. However, as reviewed here, there is now substantial evidence supporting the use of MSC-EVs in tissue engineering and regenerative medicine and further research to establish how best to exploit this approach for societal and economic benefit is warranted.

Cell Death Pathways in Ischemic Stroke and Targeted Pharmacotherapy

Ischemic stroke is one of the significant causes of morbidity and mortality, affecting millions of people across the globe. Cell injury in the infarct region is an inevitable consequence of focal cerebral ischemia. Subsequent reperfusion exacerbates the harmful effect and increases the infarct volume. These cellular injuries follow either a regulated pathway involving tightly structured signaling cascades and molecularly defined effector mechanisms or a non-regulated pathway, also known as accidental cell death, where the process is biologically uncontrolled. Classical cell death pathways are long established and well reported in several articles that majorly define apoptotic cell death. A recent focus on cell death study also considers investigation on non-classical pathways that are tightly regulated, may or may not involve caspases, but non-apoptotic. Pathological cell death is a cardinal feature of different neurodegenerative diseases. Although ischemia cannot be classified as a neurodegenerative disease, it is a cerebrovascular event where the infarct region exhibits aberrant cell death. Over the past few decades, several therapeutic options have been implicated for ischemic stroke. However, their use has been hampered owing to the number of limitations that they possess. Ischemic penumbral neurons undergo apoptosis and become dysfunctional; however, they are salvageable. Thus, understanding the role of different cell death pathways is crucial to aid in the modern treatment of protecting apoptotic neurons.

miR106a Promotes the Growth of Transplanted Breast Cancer and Decreases the Sensitivity of Transplanted Tumors to Cisplatin

Objective

To explore the effect of miR106a on the growth of breast cancer xenografts and the sensitivity of chemotherapeutic agents.

Methods

Breast cancer cell lines (MDA-MB231 and MCF7) were transfected with an miR106 mimic and miR106a inhibitor. BALB/c female nude mice were selected to construct a transplanted-tumor model. Cisplatin treatment was performed 2 weeks after inoculation. After 5 weeks, tumor tissue was weighed. Apoptosis of tumor cells was detected by TUNEL staining. The expression of these proteins (Ki67, β-catenin, cyclin D1 and cMyc) was detected by immunohistochemistry. The contents of P53, RUNX3, ABCG2, β-catenin, BAX, and BCL2 mRNA were detected by qRT-PCR.

Results

The miR106a mimic (MM) group’s tumor volume and weight were significantly bigger than those of the model group. miR106a mRNA content was higher than the blank control group, and β-catenin and Ki67 protein were strongly positive. β-catenin, BCL2, and ABCG2 mRNA content was were increased. P53, BAX, and RUNX3 mRNA content was decreased. The number of positive cells on TUNEL staining was significantly lower in the miR106a inhibitor (MI) group. After cisplatin treatment, inhibition of tumor growth was most obvious in the MI+DDP (cisplatin) group. Compared with the MM group, tumor growth in the MM+FH535 (Wnt-pathway inhibitor) group was significantly lower, and Wnt-pathway activity was decreased.

Conclusion

Overexpression of miR106a can promote the growth of transplanted breast cancer and decrease the sensitivity of transplanted tumors to cisplatin. The mechanism may be related to abnormal activation of the Wnt-signaling pathway.