Comparison of gene expression of umbilical cord vein and bone marrow-derived mesenchymal stem cells

Annexin A family: A new perspective on the regulation of bone metabolism

Osteoblast-mediated bone formation and osteoclast-mediated bone resorption are critical processes in bone metabolism. Annexin A, a calcium-phospholipid binding protein, regulates the proliferation and differentiation of bone cells, including bone marrow mesenchymal stem cells, osteoblasts, and osteoclasts, and has gradually become a marker gene for the diagnosis of osteoporosis. As calcium channel proteins, the annexin A family members are closely associated with mechanical stress, which can target annexins A1, A5, and A6 to promote bone cell differentiation. Despite the significant clinical potential of annexin A family members in bone metabolism, few studies have reported on these mechanisms. Therefore, based on a review of relevant literature, this article elaborates on the specific functions and possible mechanisms of annexin A family members in bone metabolism to provide new ideas for their application in the prevention and treatment of bone diseases, such as osteoporosis.

The Mechanism of Pyroptosis and Its Application Prospect in Diabetic Wound Healing

Pyroptosis defines a form of pro-inflammatory-dependent programmed cell death triggered by gasdermin proteins, which creates cytoplasmic pores and promotes the activation and accumulation of immune cells by releasing several pro-inflammatory mediators and immunogenic substances upon cell rupture. Pyroptosis comprises canonical (mediated by Caspase-1) and non-canonical (mediated by Caspase-4/5/11) molecular signaling pathways. Numerous studies have explored the contributory roles of inflammasome and pyroptosis in the progression of multiple pathological conditions such as tumors, nerve injury, inflammatory diseases and metabolic disorders. Accumulating evidence indicates that the activation of the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome results in the activation of pyroptosis and inflammation. Current evidence suggests that pyroptosis-dependent cell death plays a progressive role in the development of diabetic complications including diabetic wound healing (DWH) and diabetic foot ulcers (DFUs). This review presents a brief overview of the molecular mechanisms underlying pyroptosis and addresses the current research on pyroptosis-dependent signaling pathways in the context of DWH. In this review, we also present some prospective therapeutic compounds/agents that can target pyroptotic signaling pathways, which may serve as new strategies for the effective treatment and management of diabetic wounds.

Efficacy of growth factor gene-modified stem cells for motor function after spinal cord injury in rodents: a systematic review and meta‑analysis

The efficacy of growth factor gene-modified stem cells in treating spinal cord injury (SCI) remains unclear. This study aims to evaluate the effectiveness of growth factor gene-modified stem cells in restoring motor function after SCI. Two reviewers searched four databases, including PubMed, Embase, Web of Science, and Scopus, to identify relevant records. Studies on rodents assessing the efficacy of transplanting growth factor gene-modified stem cells in restoring motor function after SCI were included. The results were reported using the standardized mean difference (SMD) with a 95% confidence interval (95% CI). Analyses showed that growth factor gene-modified stem cell transplantation improved motor function recovery in rodents with SCI compared to the untreated (SMD = 3.98, 95% CI 3.26-4.70, I2 = 86.8%, P < 0.0001) and stem cell (SMD = 2.53, 95% CI 1.93-3.13, I2 = 86.9%, P < 0.0001) groups. Using growth factor gene-modified neural stem/histone cells enhanced treatment efficacy. In addition, the effectiveness increased when viral vectors were employed for gene modification and high transplantation doses were administered during the subacute phase. Stem cells derived from the human umbilical cord exhibited an advantage in motor function recovery. However, the transplantation of growth factor gene-modified stem cells did not significantly improve motor function in male rodents (P = 0.136). Transplantation of growth factor gene-modified stem cells improved motor function in rodents after SCI, but claims of enhanced efficacy should be approached with caution. The safety of gene modification remains a significant concern, requiring additional efforts to enhance its clinical translatability.

Umbilical cord mesenchymal stem cell-derived apoptotic extracellular vesicles ameliorate cutaneous wound healing in type 2 diabetic mice via macrophage pyroptosis inhibition

BACKGROUND

Delayed healing of diabetic cutaneous wounds is one of the most common complications of type 2 diabetes mellitus (T2DM), which can bring great distress to patients. In diabetic patients, macrophages accumulate around skin wounds and produce NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasomes, which in turn undergo pyroptosis and produce inflammatory factors such as interleukin-1β that affect wound healing. Although our previous study revealed that apoptotic extracellular vesicles (ApoEVs) produced from mesenchymal stem cells (MSCs) improve cutaneous wound healing in normal C57BL/6 mice, whether ApoEVs can also improve diabetic wound healing remains unclear.

METHODS

Umbilical cord mesenchymal stem cells (UCMSCs) were cultured in vitro and apoptosis was induced. ApoEVs were extracted and identified and used in a T2DM mouse cutaneous wound model to evaluate the efficacy. The inhibitory effect of ApoEVs on macrophage pyroptosis was verified in vivo and in vitro, and the level of oxidative stress in macrophages was assessed to explore the mechanism by which ApoEVs play a role.

RESULTS

UCMSC-derived ApoEVs improved skin defect healing in T2DM mice. Moreover, UCMSC-derived ApoEVs inhibited macrophage pyroptosis in T2DM mice in vivo as well as in vitro under high-glucose culture conditions. In addition, we demonstrated that ApoEVs reduce oxidative stress levels, which is a possible mechanism by which they inhibit macrophage pyroptosis.

CONCLUSIONS

Our study confirmed that local application of UCMSC-derived ApoEVs improved cutaneous wound healing in T2DM mice. ApoEVs, as products of MSC apoptosis, can inhibit macrophage pyroptosis and regulate the death process by decreasing the level of oxidative stress.

Clinical utility of mesenchymal stem/stromal cells in regenerative medicine and cellular therapy

Mesenchymal stem/stromal cells (MSCs) have been carefully examined to have tremendous potential in regenerative medicine. With their immunomodulatory and regenerative properties, MSCs have numerous applications within the clinical sector. MSCs have the properties of multilineage differentiation, paracrine signaling, and can be isolated from various tissues, which makes them a key candidate for applications in numerous organ systems. To accentuate the importance of MSC therapy for a range of clinical indications, this review highlights MSC-specific studies on the musculoskeletal, nervous, cardiovascular, and immune systems where most trials are reported. Furthermore, an updated list of the different types of MSCs used in clinical trials, as well as the key characteristics of each type of MSCs are included. Many of the studies mentioned revolve around the properties of MSC, such as exosome usage and MSC co-cultures with other cell types. It is worth noting that MSC clinical usage is not limited to these four systems, and MSCs continue to be tested to repair, regenerate, or modulate other diseased or injured organ systems. This review provides an updated compilation of MSCs in clinical trials that paves the way for improvement in the field of MSC therapy.

Advances in Mesenchymal Stem Cell Therapy for Osteoarthritis: From Preclinical and Clinical Perspectives

The prevalence of osteoarthritis (OA), a degenerative disorder of joints, has substantially increased in recent years. Its key pathogenic hallmarks include articular cartilage destruction, synovium inflammation, and bone remodeling. However, treatment outcomes are unsatisfactory. Until recently, common therapy methods, such as analgesic and anti-inflammatory treatments, were aimed to treat symptoms that cannot be radically cured. Mesenchymal stem cells (MSCs), i.e., mesoderm non-hematopoietic cells separated from bone marrow, adipose tissue, umbilical cord blood, etc., have been intensively explored as an emerging technique for the treatment of OA over the last few decades. According to existing research, MSCs may limit cartilage degradation in OA by interfering with cellular immunity and secreting a number of active chemicals. This study aimed to examine the potential mechanism of MSCs in the treatment of OA and conduct a thorough review of both preclinical and clinical data.

Comparison of the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells and adipose-derived stem cells on erectile dysfunction in a rat model of bilateral cavernous nerve injury

Background: Cavernous nerve injury (CNI) is the leading cause of erectile dysfunction (ED) after radical prostatectomy and pelvic fracture. Transplantation of human adipose-derived stem cells (ASCs) has been widely used to restore erectile function in CNI-ED rats and patients. Umbilical cord blood-derived MSCs (CBMSCs) are similarly low immunogenic but much primitive compared to ASCs and more promising in large-scale commercial applications due to the extensive establishment of cord blood banks. However, whether CBMSCs and ASCs have differential therapeutic efficacy on CNI-ED and the underlying mechanisms are still not clear.

Materials and methods: A bilateral cavernous nerve injury (BCNI) rat model was established by crushing the bilateral cavernous nerves. After crushing, ASCs and CBMSCs were intracavernously injected immediately. Erectile function, Masson staining, and immunofluorescence analyses of penile tissues were assessed at 4 and 12 weeks. PKH-26-labeled ASCs or CBMSCs were intracavernously injected to determine the presence and differentiation of ASCs or CBMSCs in the penis 3 days after injection. In vitro experiments including intracellular ROS detection, mitochondrial membrane potential assay, EdU cell proliferation staining, cell apoptosis assay, and protein chip assay were conducted to explore the underlying mechanism of CBMSC treatment compared with ASC treatment.

Results: CBMSC injection significantly restored erectile function, rescued the loss of cavernous corporal smooth muscles, and increased the ratio of smooth muscle to collagen. PKH-26-labeled CBMSCs or ASCs did not colocalize with endothelial cells or smooth muscle cells in the corpus cavernosum. Moreover, the conditioned medium (CM) of CBMSCs could significantly inhibit the oxidative stress and elevate the mitochondria membrane potential and proliferation of Schwann cells. Better therapeutic effects were observed in the CBMSC group than the ASC group both in vivo and in vitro. In addition, the content of neurotrophic factors and matrix metalloproteinases in CBMSC-CM, especially NT4, VEGF, MMP1, and MMP3 was significantly higher than that of ASC-CM.

Conclusion: Intracavernous injection of CBMSCs exhibited a better erectile function restoration than that of ASCs in CNI-ED rats owing to richer secretory factors, which can promote nerve regeneration and reduce extracellular matrix deposition. CBMSC transplantation would be a promising therapeutic strategy for CNI-ED regeneration in the future.

Stem cells for treatment of liver fibrosis/cirrhosis: clinical progress and therapeutic potential

Cost-effective treatment strategies for liver fibrosis or cirrhosis are limited. Many clinical trials of stem cells for liver disease shown that stem cells might be a potential therapeutic approach. This review will summarize the published clinical trials of stem cells for the treatment of liver fibrosis/cirrhosis and provide the latest overview of various cell sources, cell doses, and delivery methods. We also describe the limitations and strengths of various stem cells in clinical applications. Furthermore, to clarify how stem cells play a therapeutic role in liver fibrosis, we discuss the molecular mechanisms of stem cells for treatment of liver fibrosis, including liver regeneration, immunoregulation, resistance to injury, myofibroblast repression, and extracellular matrix degradation. We provide a perspective for the prospects of future clinical implementation of stem cells.

Impact of Microenvironmental Changes during Degeneration on Intervertebral Disc Progenitor Cells: A Comparison with Mesenchymal Stem Cells

Intervertebral disc (IVD) degeneration occurs with natural ageing and is linked to low back pain, a common disease. As an avascular tissue, the microenvironment inside the IVD is harsh. During degeneration, the condition becomes even more compromised, presenting a significant challenge to the survival and function of the resident cells, as well as to any regeneration attempts using cell implantation. Mesenchymal stem cells (MSCs) have been proposed as a candidate stem cell tool for IVD regeneration. Recently, endogenous IVD progenitor cells have been identified inside the IVD, highlighting their potential for self-repair. IVD progenitor cells have properties similar to MSCs, with minor differences in potency and surface marker expression. Currently, it is unclear how IVD progenitor cells react to microenvironmental factors and in what ways they possibly behave differently to MSCs. Here, we first summarized the microenvironmental factors presented in the IVD and their changes during degeneration. Then, we analyzed the available studies on the responses of IVD progenitor cells and MSCs to these factors, and made comparisons between these two types of cells, when possible, in an attempt to achieve a clear understanding of the characteristics of IVD progenitor cells when compared to MSCs; as well as, to provide possible clues to cell fate after implantation, which may facilitate future manipulation and design of IVD regeneration studies.

Bone Regeneration and Angiogenesis by Co-transplantation of Angiotensin II-Pretreated Mesenchymal Stem Cells and Endothelial Cells in Early Steroid-Induced Osteonecrosis of the Femoral Head

Mesenchymal stem cells (MSCs) have been shown to exert a positive impact on osteonecrosis of the femoral head (ONFH) in preclinical experiments and clinical trials. After the femoral head suffers avascular necrosis, the transplanted MSCs undergo a great deal of stress-induced apoptosis and senescence in this microenvironment. So, survival and differentiation of MSCs in osteonecrotic areas are especially important in ONFH. Although MSCs and endothelial cells (ECs) co-culture enhancing proliferation and osteogenic differentiation of MSCs and form more mature vasculature in vivo, it remains unknown whether the co-culture cells are able to repair ONFH. In this study, we explored the roles and mechanisms of co-transplantation of angiotensin II (Ang II)-MSCs and ECs in repairing early ONFH. In vitro, when MSCs and ECs were co-cultured in a ratio of 5:1, both types of cells managed to proliferate and induce both osteogenesis and angiogenesis. Then, we established a rabbit model of steroid-induced ONFH and co-transplantation of Ang II-MSCs and ECs through the tunnel of core decompression. Four weeks later, histological and Western blot analyses revealed that ONFH treated with Ang II-MSCs and ECs may promote ossification and revascularization by increasing the expression of collagen type I, runt-related transcription factor 2, osteocalcin, and vascular endothelial growth factor in the femoral head. Our data suggest that co-transplantation of Ang II-MSCs and ECs was able to rescue the early steroid-induced ONFH via promoting osteogenesis and angiogenesis, which may be regarded as a novel therapy for the treatment of ONFH in a clinical setting.

Biological, chemical and mechanical factors regulating migration and homing of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are a population of primary and non-specialized cells, which can be isolated from various tissues. Currently, MSCs are key players in cellular therapy and regenerative medicine. However, the possibility of using MSCs in the treatment of many diseases needs to be preceded, though, by in-depth analysis of their properties, especially by determining the mechanism of tissue homing as well as the mechanism, due to which cells contribute to tissue regeneration. This review is intended to present information on recent findings regarding the mechanism of recruitment and tissue homing by MSCs and discuss current hypotheses for how MSCs can reach target tissues.

Ultrasonic Freezing Reduces Protein Oxidation and Myofibrillar Gel Quality Loss of Common Carp (Cyprinus carpio) during Long-Time Frozen Storage

Ultrasonic freezing (UF) is an effective method to increase the freezing speed and improve the quality of frozen food. The effect of UF on myofibrillar protein oxidation and gel properties of common carp (Cyprinus carpio) during frozen storage were investigated with air freezing (AF) and immersion freezing (IF) as controls. The results showed that the carbonyl and dityrosine content of UF samples were lower and the free amine content was higher than those of AF and IF samples during frozen storage indicating that UF inhibited protein oxidation caused by frozen storage. The particle size of UF myofibrillar protein was the smallest among all the groups indicating that UF inhibited the protein aggregation. The UF sample had higher G', G" value, gel strength and gel water holding capacity than AF and IF groups showing that UF reduced the loss of protein gel properties. The gel microstructure showed that UF protein gel was characterized by smaller and finer pores than other samples, which further proves that UF inhibited loss of gel properties during frozen storage. The UF sample had shorter T2 transition time than other samples demonstrating that UF decreased the mobility of water. In general, UF is an effective method to reduce protein oxidation and gel properties loss caused by frozen storage.

Neovascularization: The Main Mechanism of MSCs in Ischemic Heart Disease Therapy

Mesenchymal stem cell (MSC) transplantation after myocardial infarction (MI) has been shown to effectively limit the infarct area in numerous clinical and preclinical studies. However, the primary mechanism associated with this activity in MSC transplantation therapy remains unclear. Blood supply is fundamental for the survival of myocardial tissue, and the formation of an efficient vascular network is a prerequisite for blood flow. The paracrine function of MSCs, which is throughout the neovascularization process, including MSC mobilization, migration, homing, adhesion and retention, regulates angiogenesis and vasculogenesis through existing endothelial cells (ECs) and endothelial progenitor cells (EPCs). Additionally, MSCs have the ability to differentiate into multiple cell lineages and can be mobilized and migrate to ischemic tissue to differentiate into ECs, pericytes and smooth muscle cells in some degree, which are necessary components of blood vessels. These characteristics of MSCs support the view that these cells improve ischemic myocardium through angiogenesis and vasculogenesis. In this review, the results of recent clinical and preclinical studies are discussed to illustrate the processes and mechanisms of neovascularization in ischemic heart disease.

The Potentiality of Human Umbilical Cord Isolated Mesenchymal Stem/Stromal Cells for Cardiomyocyte Generation

Background

The new therapeutic strategy of managing cardiac diseases is based on cell therapy; it highly suggests the use of multipotent mesenchymal stem/stromal cells (MSCs). MSCs widely used in researches are known to be isolated from bone marrow. However, this research seeks to use a human umbilical cord (HUC) as an alternative source of MSCs. Since HUC Wharton's jelly (WJ)-isolated MSCs originate as fetal tissue they are highly preferable for their potential advantages over other adult tissues.

Methods

The researchers used enzymatic digestion to establish a primary HUC-WJ-isolated MSC line. Then, flow cytometry was used to characterize MSCs and hematopoietic stem cells (HSCs) markers' expression. In addition, the cardiac differentiation capacity of HUC-WJ-isolated MSCs in vitro was investigated by two protocols. Protocol-1 necessitates the dependence on merely 5-azacytidine (5-Aza), whereas in protocol-2, 5-Aza was supported by basic fibroblast growth factor (BFGF). The comparative study between the two protocols was applied by inspecting the ultrastructure of differentiated cells, measuring RT-PCR mRNA cardiac markers and the quantitative detection of cardiac proteins.

Results

HUC-WJ isolated MSCs were expressed by CD90^+ve, CD105^+ve, CD106^+ve, CD45^-ve, and CD146^-ve. Remarkable TNNT1, NKX2.5, and Desmin mRNA expression and higher quantitative LDH and cTnI were detected by applying protocol-2. This same protocol-2 induced cardiac morphological features that were revealed by identifying cardiomyocyte-like cells and typical sarcomeres.

Conclusion

HUC-WJ is proved to be an ethical and effective source of MSCs induced cardiac differentiation, whereas BFGF supports 5-Aza in MSCs-cardiomyocytes differentiation.

Co-transplantation of mesenchymal stem cells makes haploidentical HSCT a potential comparable therapy with matched sibling donor HSCT for patients with severe aplastic anemia

The application of haploidentical hematopoietic stem cell transplantation (HSCT) with mesenchymal stem cell (MSC) infusion as a treatment regimen for severe aplastic anemia (SAA) has been reported to be efficacious in single-arm trials. However, it is difficult to assess without comparing the results with those from a first-line, matched-sibling HSCT. Herein, we retrospectively reviewed 91 patients with acquired SAA. They received HSCT from haploidentical donors combined with MSC transfer (HID group). We compared these patients with 103 others who received first-line matched-sibling HSCT (MSD group) to evaluate relative treatment efficacy. Compared with the patients in the MSD group, those in the HID group presented with higher incidences of grades II–IV and III–IV acute graft versus host disease (aGvHD) and chronic graft versus host disease (cGvHD) (p < 0.05). However, the incidence of myeloid and platelet engraftment, graft failure, poor graft function, and extensive cGvHD were comparable for both groups. The median follow-up was 36.6 months and the 3-year overall survival rate was similar for both groups (83.5% versus 79.1%). Univariate and multivariate analyses revealed that time intervals greater than 4 months from diagnosis to transplantation, experienced graft failure, poor graft function, or grade III–IV aGvHD were significantly associated with adverse outcomes. All HID patients received MSC co-transplantation with hematopoietic stem cells. However, the infused MSCs were derived from umbilical cord (UC-MSC group; 43 patients) or bone marrow (BM-MSC group; 48 patients) and were administered at different medical centers. We first compared the outcomes between the two groups and detected that the BM-MSC group exhibited lower incidences of grade III–IV aGvHD and cGvHD (p < 0.05). This study suggests that co-transplantation of hematopoietic and MSCs significantly reduces the risk and incidence of graft rejection and may effectively improve overall survival in patients with SAA even in the absence of closely related histocompatible donor material.

Bone marrow coagulated and low-level laser therapy accelerate bone healing by enhancing angiogenesis, cell proliferation, osteoblast differentiation, and mineralization

The present study evaluated bone marrow aspirate (BMA) and low-level laser therapy (LLLT) on bone healing. It was created critical-size defects (CSD) of 5 mm diameter in rat calvaria of 64 rats. Animals were randomly divided into four groups: Control (blood clot), BMA (coagulated BMA), LLLT (laser irradiation and blood clot), and BMA/LLLT (laser irradiation and coagulated BMA). Euthanasia was performed at 15 or 30 days postoperative. Immunohistochemical reactions were performed to identify vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), runt-related transcription factor-2 (Runx2), bone morphogenetic protein-2 (BMP-2), osteocalcin (OCN), and osteopontin (OPN). The markers were quantified, and data were statistically analyzed. Groups BMA/LLLT and LLLT presented significantly higher VEGF expression than group control. Group BMA/LLLT presented a significantly higher expression of PCNA than all experimental groups. Groups BMA and BMA/LLLT presented significantly higher expression of BMP-2 than all experimental groups. Groups LLLT and BMA/LLLT presented significantly higher expression of OPN than groups control and BMA. Groups LLLT, BMA, and BMA/LLLT presented a significantly higher expression of OCN than group control. It can be concluded that the association of BMA and LLLT enhanced bone healing by improving expression of VEGF, PCNA, Runx2, BMP-2, OPN, and OCN.

Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells Accelerate Cutaneous Wound Healing by Enhancing Angiogenesis through Delivering Angiopoietin-2

The underlying mechanisms of human umbilical cord mesenchymal stem cells (hucMSCs) and their exosomes (hucMSC-Exs), which play significant roles in skin wound healing, remain poorly understood. By using a rat model of deep second-degree burn injury, the roles of hucMSC-Exs in angiogenesis and cutaneous wound healing in vivo were investigated. We found that hucMSC-Exs accelerated skin wound healing and angiogenesis, inducing a higher wound-closure rate and increased expression of CD31 in vivo. We also discovered that hucMSC-Exs contained angiopoietin-2 (Ang-2), and treatment with hucMSC-Exs enhanced the expression of the Ang-2 protein in the wound area and human umbilical vein endothelial cells (HUVECs) through exosomal-mediated Ang-2 transfer. Moreover, hucMSC-Exs promoted the proliferative, migratory, and tube-forming ability of HUVECs. Furthermore, overexpression of Ang-2 in hucMSC-Exs further enhanced HUVEC migration and tube formation and exerted therapeutic and proangiogenic effects in cutaneous wounds in rats, whereas knockdown of Ang-2 in hucMSC-Exs abrogated these therapeutic and proangiogenic effects. Taken together, our results indicated that hucMSC-Ex-derived Ang-2 plays a significant role in tube formation of HUVECs and promotion of angiogenesis, and further suggested that hucMSC-Ex-based therapy may serve as a promising therapeutic approach for promoting cutaneous wound healing.

From 2646 to 15: differentially regulated microRNAs between progenitors from normal myometrium and leiomyoma

BACKGROUND

Uterine leiomyomas (fibroids) are smooth muscle neoplasms of the myometrial layer of the uterus and are the most common benign tumors in women. Although their etiology is still unclear, progenitor cells seem to be implicated.

OBJECTIVE

To identify the dysregulated pathways involved in leiomyoma onset by microRNA profiling of progenitor cells isolated from normal myometrium and leiomyoma tissue.

MATERIALS AND METHODS

Pairs of normal myometrium and uterine fibroid specimens were collected from 12 myomectomy patients. Myometrial progenitor cells and leiomyoma progenitor cells were isolated and characterized for stemness. After total RNA extraction and profiling of their 2646 microRNAs, DIANA-miRPath analysis was applied to find any dysregulated pathways.

RESULTS

Only 30 microRNAs showed a significant differential regulation between myometrial progenitor cells and leiomyoma progenitor cells. Removal of those that had values close to the cut-off or that were not consistent among triplicates left 15 microRNAs, of which 7 were downregulated and 8 were upregulated in leiomyoma progenitor cells compared to myometrial progenitor cells. According to DIANA-miRPath analysis, the 7 downregulated microRNAs (hsa-miR-146b-5p; hsa-miR-335-3p; hsa-miR-335-5p; hsa-miR-135b-5p; hsa-miR-10a-3p; hsa-miR-10a-5p; hsa-miR-200a-3p) are all related to 3 pathways, "ECM-receptor interaction" (33 targeted genes), "Adherens junction" (33 targeted genes), and "Hippo signaling" (69 targeted genes), whereas the 8 upregulated miRNAs (hsa-miR-146a-5p; hsa-miR-576-3p; hsa-miR-122-5p; hsa-miR-1246; hsa-miR-595; hsa-miR-658; hsa-miR-4284; hsa-miR-924) are related to 4 pathways, "PI3K-Akt signaling pathway" (71 targeted genes), "Pathways in Cancer" (80 targeted genes), "Cell Cycle" (37 targeted genes), and "Regulation of actin cytoskeleton" (41 targeted genes).

CONCLUSION

The findings that only 15 of 2646 microRNAs are differentially regulated in normal myometrium and leiomyoma and that they are involved in 7 dysregulated pathways provides interesting insights into the development of uterine fibroids, and lends support to the hypothesis that leiomyoma onset is the result of alterations affecting progenitor cells.

Transcriptome and proteome profiles of human umbilical cord vein CD146+ stem cells

In this study we used two different techniques in order to isolate pericytes from the wall of human umbilical cord vein and get two different groups of cells were named as "pellet and primer cells". These groups were compared with each other according to their morphologies and stem cell marker expressions. Also, these two different populations were compared with each other and with human bone marrow mesenchymal stem cells (BM-MSCs) according to their transcriptomic profiles. Then, pellet cells proteomic profiles were determined. Our results showed that morphologies and cell surface marker expressions of pellet cells and primer cells are similar. On the other hand, according to immunofluorescence staining results, in contrast to primer cells, pellet cells showed positive NG2 and PDGFR-β staining. As a result of gene expression profiling, pellet cells have upregulated genes related with muscle, neural and immune cell differentiation, development and pluripotency. On the other hand, primer cells have upregulated adhesion pathway-related genes. In addition to differences between pellet and primer cells, the gene expression profiles of these cell groups are also different from BM-MSCs. The results of transcriptome and proteome analysis of pellet cells were in consistent with each other.

Will cell therapies provide the solution for the shortage of transplantable organs?

PURPOSE OF REVIEW

The potential to regenerate ischemically damaged kidneys while being perfused ex-vivo offers the best near-term solution to increasing kidney allografts for transplantation.

RECENT FINDINGS

There are a number of stem-cell sources including: stromal mesenchymal cells (MSC), induced adult pluripotent stem cells, fetal stem cells from placenta, membranes, amniotic fluid and umbilical cord and hematopoietic cells. MSC are increasingly the stem cell of choice and studies are primarily focused on novel induction immunosuppression to prevent rejection. Stem-cell therapies applied in vivo may be of limited benefit because the nonintegrating cells do not remain in the kidney and are not detectable in the body after several days. MSC therapies for transplantation have demonstrated early safety and feasibility. However, efficacy has not been clearly established. A more feasible application of a stem-cell therapy in transplantation is the administration of MSC to treat damaged renal allografts directly while being perfused ex vivo. Initial feasibility has been established demonstrating MSC-treatment results in statistically significant reduction of inflammatory responses, increased ATP and growth factor synthesis and mitosis.

SUMMARY

The ability to regenerate renal tissue ex-vivo sufficiently to result in immediate function could revolutionize transplantation by solving the chronic organ shortage.

Mesenchymal stem cells modifications for enhanced bone targeting and bone regeneration

In pathological bone conditions (e.g., osteoporotic fractures or critical size bone defects), increasing the pool of osteoblast progenitor cells is a promising therapeutic approach to facilitate bone healing. Since mesenchymal stem cells (MSCs) give rise to the osteogenic lineage, a number of clinical trials investigated the potential of MSCs transplantation for bone regeneration. However, the engraftment of transplanted cells is often hindered by insufficient oxygen and nutrients supply and the tendency of MSCs to home to different sites of the body. In this review, we discuss various approaches of MSCs transplantation for bone regeneration including scaffold and hydrogel constructs, genetic modifications and surface engineering of the cell membrane aimed to improve homing and increase cell viability, proliferation and differentiation.

Human Wharton's Jelly-Cellular Specificity, Stemness Potency, Animal Models, and Current Application in Human Clinical Trials

Stem cell therapies offer a great promise for regenerative and reconstructive medicine, due to their self-renewal and differentiation capacity. Although embryonic stem cells are pluripotent, their utilization involves embryo destruction and is ethically controversial. Therefore, adult tissues that have emerged as an alternative source of stem cells and perinatal tissues, such as the umbilical cord, appear to be particularly attractive. Wharton's jelly, a gelatinous connective tissue contained in the umbilical cord, is abundant in mesenchymal stem cells (MSCs) that express CD105, CD73, CD90, Oct-4, Sox-2, and Nanog among others, and have the ability to differentiate into osteogenic, adipogenic, chondrogenic, and other lineages. Moreover, Wharton's jelly-derived MSCs (WJ-MSCs) do not express MHC-II and exhibit immunomodulatory properties, which makes them a good alternative for allogeneic and xenogeneic transplantations in cellular therapies. Therefore, umbilical cord, especially Wharton's jelly, is a promising source of mesenchymal stem cells.

Mesenchymal Stem Cell Therapy for Spinal Cord Contusion: A Comparative Study on Small and Large Animal Models

Here, we provide a first comparative study of the therapeutic potential of allogeneic mesenchymal stem cells derived from bone marrow (BM-MSCs), adipose tissue (AD-MSCs), and dental pulp (DP-MSCs) embedded in fibrin matrix, in small (rat) and large (pig) spinal cord injury (SCI) models during subacute period of spinal contusion. Results of behavioral, electrophysiological, and histological assessment as well as immunohistochemistry and real-time polymerase chain reaction analysis suggest that application of AD-MSCs combined with a fibrin matrix within the subacute period in rats (2 weeks after injury), provides significantly higher post-traumatic regeneration compared to a similar application of BM-MSCs or DP-MSCs. Within the rat model, use of AD-MSCs resulted in a marked change in: (1) restoration of locomotor activity and conduction along spinal axons; (2) reduction of post-traumatic cavitation and enhancing tissue retention; and (3) modulation of microglial and astroglial activation. The effect of an autologous application of AD-MSCs during the subacute period after spinal contusion was also confirmed in pigs (6 weeks after injury). Effects included: (1) partial restoration of the somatosensory spinal pathways; (2) reduction of post-traumatic cavitation and enhancing tissue retention; and (3) modulation of astroglial activation in dorsal root entry zone. However, pigs only partially replicated the findings observed in rats. Together, these results indicate application of AD-MSCs embedded in fibrin matrix at the site of SCI during the subacute period can facilitate regeneration of nervous tissue in rats and pigs. These results, for the first time, provide robust support for the use of AD-MSC to treat subacute SCI.

Secretome Conveys the Protective Effects of ASCs: Therapeutic Potential Following Hemorrhagic Shock?

OBJECTIVES

We tested whether resuscitation supplemented with rat adipose-derived stem cells (ASCs) or secretome (conditioned media) of ASCs can ameliorate inflammation, cell/organ injury, and/or improve outcome after hemorrhagic traumatic shock (HTS).

INTERVENTIONS

Rats were subjected to HTS and a resuscitation protocol that mimics prehospital restrictive reperfusion followed by an adequate reperfusion phase. Twenty minutes into the restrictive reperfusion, animals received an intravenous bolus of 2 × 10 cells (ASC group) or the secretome produced by 2 × 10 ASCs/24 h (ASC-Secretome group). Controls received the vehicle (Vehicle group). All rats were observed for 28-day survival.

MEASUREMENTS AND MAIN RESULTS

HTS-induced inflammation represented by IL-6 was inhibited in the ASC (80%, P < 0.001) and in ASC-Secretome (59%, P < 0.01) group at 48 h compared with Vehicle group. At 24 h, HTS-induced liver injury reflected in plasma alanine aminotransferase was ameliorated by 36% (P < 0.001) in both the ASC and ASC-Secretome groups when compared with the Vehicle. There was no effect on kidney function and/or general cell injury markers. HTS induced a moderate 28-day mortality (18%) that was prevented (P = 0.08) in the ASC but not in the ASC-Secretome group (12%).

CONCLUSIONS

Our data suggest that the ASC-secretome supplemented resuscitation following HTS, in the absence of the stem cells, exerts anti-inflammatory and liver protective effects. Given its ease of preparation, storage, availability, and application (in contrast to the stem cells) we believe that the cell-free secretome has a better therapeutic potential in the early phase of an acute hemorrhagic shock scenario.

Bone Marrow Stromal Cells Alleviate Secondary Damage in the Substantia Nigra After Focal Cerebral Infarction in Rats

Transplantation of bone marrow stromal cells (BMSCs) is a promising therapy for ischemic stroke. Previously, we had reported that the secondary degeneration occurred in the ipsilateral substantia nigra (SN) after permanent distal branch of middle cerebral artery occlusion (dMCAO) in Sprague-Dawley rats. However, whether BMSCs have neurorestorative effects on the secondary damage in the SN after focal cerebral infarction has not known. In this study, rats were subjected to dMCAO followed by intravenous administration of BMSCs 1 day later. We found that transplanted BMSCs survived and migrated to cortical infarct areas and ipsilateral SN. Furthermore, BMSCs promoted neurogenesis through proliferation and differentiation in the SN after dMCAO. Rats implanted with BMSCs showed significant improvement in their performance of modified neurological severity scores and adhesive-removal test. Engrafted BMSCs enhanced survival of dopaminergic neuron, reduced gliosis in the ipsilateral SN, and increased contents of dopamine (DA) and its metabolites in the ipsilateral striatum after dMCAO. With pseudorabies virus-152 as a retrograde tracer, we also demonstrated that BMSCs could effectively enhance the cortico-striatum-nigral connections. These results suggest that BMSCs transplantation exerts neurorestorative effects after cortical infarction through promoting endogenous neurogenesis, increasing contents of DA and its metabolites, alleviating the secondary neuronal damage in the SN, enhancing the cortico-striatum-nigral projections pathway, and finally improving the neurological functional outcome.

Effect of cell source and osteoblast differentiation on gene expression profiles of mesenchymal stem cells derived from bone marrow or adipose tissue

Mesenchymal stem cells (MSCs) have been used in therapies for bone tissue healing. The aim of this study was to investigate the effect of cell source and osteoblast differentiation on gene expression profiles of MSCs from bone marrow (BM-MSCs) or adipose tissue (AT-MSCs) to contribute for selecting a suitable cell population to be used in cell-based strategies for bone regeneration. BM-MSCs and AT-MSCs were cultured in growth medium to keep MSCs characteristics or in osteogenic medium to induce osteoblast differentiation (BM-OBs and AT-OBs). The transcriptomic analysis was performed by microarray covering the entire rat functional genome. It was observed that cells from bone marrow presented higher expression of genes related to osteogenesis, whereas cells from adipose tissue showed a higher expression of genes related to angiogenesis and adipocyte differentiation, irrespective of cell differentiation. By comparing cells from the same source, MSCs from both sources exhibited higher expression of genes involved in angiogenesis, osteoblast differentiation, and bone morphogenesis than osteoblasts. The clustering analysis showed that AT-OBs exhibited a gene expression profile closer to MSCs from both sources than BM-OBs, suggesting that BM-OBs were in a more advanced stage of differentiation. In conclusion, our results suggest that in cell-based therapies for bone regeneration AT-MSCs could be considered for angiogenic purposes, whereas BM-MSCs and osteoblasts differentiated from either source could be better for osteogenic approaches.

Bone marrow vs Wharton's jelly mesenchymal stem cells in experimental sepsis: a comparative study

BACKGROUND

The use of mesenchymal stem cells (MSCs) is being extensively studied in clinical trials in the setting of various diseases including diabetes, stroke, and progressive multiple sclerosis. The unique immunomodulatory properties of MSCs also point them as a possible therapeutic tool during sepsis and septic shock, a devastating syndrome associated with 30-35% mortality. However, MSCs are not equal regarding their activity, depending on their tissue origin. Here, we aimed at comparing the in vivo properties of MSCs according to their tissue source (bone marrow (BM) versus Wharton's jelly (WJ)) in a murine cecal ligation and puncture (CLP) model of sepsis that mimics a human peritonitis. We hypothesized that MSC properties may vary depending on their tissue source in the setting of sepsis.

METHODS

CLP, adult, male, C57BL/6 mice were randomized in 3 groups receiving respectively 0.25 × 106 BM-MSCs, 0.25 × 106 WJ-MSCs, or 150 μL phosphate-buffered saline (PBS) intravenously 24 h after the CLP procedure.

RESULTS

We observed that both types of MSCs regulated leukocyte trafficking and reduced organ dysfunction, while only WJ-MSCs were able to improve bacterial clearance and survival.

CONCLUSION

This study highlights the importance to determine the most appropriate source of MSCs for a given therapeutic indication and suggests a better profile for WJ-MSCs during sepsis.

Stem cell therapies for wound healing

INTRODUCTION

Aberrant wound healing is a significant healthcare problem, posing a substantial burden on patients, their families, and the healthcare system. Existing treatment options remain only moderately effective and often fail to promote the closure of non-healing wounds in susceptible populations, such as aging and diabetic patients. Stem cell therapy has emerged as a promising treatment modality, with the potential to restore tissue to its pre-injured state. Of particular interest are mesenchymal stromal cells, which have been shown to accelerate wound healing by modulating the immune response and promoting angiogenesis.

AREAS COVERED

This review provides an overview of wound healing and current methods for the management of chronic wounds, as well as the current state and considerations for optimizing stem cell therapy. Considerations include stem cell types, tissue source, donor selection, cell heterogeneity, delivery methods, and genetic engineering.

EXPERT OPINION

A growing body of evidence has shown that delivery of stem cells, particularly mesenchymal stromal cells, has the potential to effectively improve the rate and quality of wound healing. However, significant additional basic and clinical research must be performed to optimize cell therapy, such as further elucidation of the therapeutic mechanisms of stem cells and standardization of clinical trial guidelines.

Therapeutic Implications of Human Umbilical Cord Mesenchymal Stromal Cells in Attenuating Influenza A(H5N1) Virus-Associated Acute Lung Injury

Background

Highly pathogenic avian influenza viruses can cause severe forms of acute lung injury (ALI) in humans, where pulmonary flooding leads to respiratory failure. The therapeutic benefits of bone marrow mesenchymal stromal cells (MSCs) have been demonstrated in a model of ALI due to influenza A(H5N1) virus. However, clinical translation is impractical and limited by a decline in efficacy as the age of the donor increases. Umbilical cord MSCs (UC-MSCs) are easier to obtain by comparison, and their primitive source may offer more-potent therapeutic effects.

Methods

Here we investigate the therapeutic efficacy of UC-MSCs on the mechanisms of pulmonary edema formation and alveolar fluid clearance and protein permeability of A(H5N1)-infected human alveolar epithelial cells. UC-MSCs were also tested in a mouse model of influenza ALI.

Results

We found that UC-MSCs were effective in restoring impaired alveolar fluid clearance and protein permeability of A(H5N1)-infected human alveolar epithelial cells. UC-MSCs consistently outperformed bone marrow MSCs, partly because of greater growth factor secretion of angiopoietin 1 and hepatocyte growth factor. Conditioned UC-MSC medium and UC-MSC exosomes were also able to recapitulate these effects. However, UC-MSCs only slightly improved survival of A(H5N1)-infected mice.

Conclusions

Our results suggest that UC-MSCs are effective in restoring alveolar fluid clearance and protein permeability in A(H5N1)-associated ALI and confer functional in addition to practical advantages over conventional bone marrow MSCs.

Osteogenic Potential of Human Umbilical Cord Mesenchymal Stem Cells on Coralline Hydroxyapatite/Calcium Carbonate Microparticles

Coralline hydroxyapatite/calcium carbonate (CHACC) is a biodegradable and osteoconductive bone graft material with promising clinical performance. CHACC has been shown to support proliferation and osteogenic differentiation of human bone marrow mesenchymal stem cells (MSCs) in vitro and demonstrated to work as a functional scaffold for bone formation in vivo. Umbilical cord matrix is a more accessible and abundant tissue source of MSCs, but its osteogenic capacity in comparison to human bone marrow when cultured on CHACC has not yet been demonstrated. In this study, we assessed the osteogenic differentiation capacity of human MSCs, isolated from bone marrow and umbilical cord matrix and characterised by flow cytometry, when cultured on 200–300 μm CHACC granules. The 3D cultures were characterised by brightfield and scanning electron microscopy (SEM). Osteogenic potential was assessed by immunocytochemistry and qPCR for key markers of bone differentiation (alkaline phosphatase, runx2, type I collagen, and osteocalcin). By day 1, the MSCs had enveloped the surface of the CHACC granules to form organoids, and by day 7, cells had proliferated to bridge nearby organoids. Extracellular matrix deposition and osteogenic differentiation were demonstrated by MSCs from both tissue sources at day 21. However, MSCs from bone marrow demonstrated superior osteogenic differentiation capability compared to those from umbilical cord matrix. In conclusion, it is possible to culture and induce osteogenic differentiation of umbilical cord matrix MSCs on CHACC. Further research is required to optimise the osteogenicity of umbilical cord matrix MSCs to release their full potential as a readily available, accessible, and abundant tissue source for bone tissue engineering.

Current Status of Canine Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Veterinary Medicine

Stem cell therapy has prompted the expansion of veterinary medicine both experimentally and clinically, with the potential to contribute to contemporary treatment strategies for various diseases and conditions for which limited or no therapeutic options are presently available. Although the application of various types of stem cells, such as bone marrow-derived mesenchymal stem cells (BM-MSCs), adipose tissue-derived mesenchymal stem cells (AT-MSCs), and umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), has promising potential to improve the health of different species, it is crucial that the benefits and drawbacks are completely evaluated before use. Umbilical cord blood (UCB) is a rich source of stem cells; nonetheless, isolation of mesenchymal stem cells (MSCs) from UCB presents technical challenges. Although MSCs have been isolated from UCB of diverse species such as human, equine, sheep, goat, and canine, there are inherent limitations of using UCB from these species for the expansion of MSCs. In this review, we investigated canine UCB (cUCB) and compared it with UCB from other species by reviewing recent articles published from February 2003 to June 2017 to gain an understanding of the limitations of cUCB in the acquisition of MSCs and to determine other suitable sources for the isolation of MSCs from canine. Our review indicates that cUCB is not an ideal source of MSCs because of insufficient volume and ethical issues. However, canine reproductive organs discarded during neutering may help broaden our understanding of effective isolation of MSCs. We recommend exploring canine reproductive and adipose tissue rather than UCB to fulfill the current need in veterinary medicine for the well-designed and ethically approved source of MSCs.

Chronic Inflammation May Enhance Leiomyoma Development by the Involvement of Progenitor Cells

Although the etiology of leiomyoma is unclear, a progenitor/undifferentiated cell population has been described whose dysregulation may be involved in the onset of uterine conditions. Moreover, inflammation is involved in the development of several tumors. The aim of this work was to understand if progenitor cells sustain a chronic inflammatory microenvironment that enhances leiomyoma development. Cells from 12 human leiomyoma and 12 normal myometrium samples of the same patients were in vitro isolated and exhaustively characterized (morphology, proliferation, cytofluorometry, differentiation, RT-PCR, immunofluorescence, immunohistochemistry, and Western blotting assays). Selected cytokines (ELISA) and inflammation-related genes (RT-PCR) were analyzed to identify healthy myometrium progenitor cells (MPCs) and leiomyoma progenitor cells (LPCs). Results show that (i) MPCs and LPCs share stemness features, such as immunophenotype and multidifferentiation assay, (ii) LPCs have a significantly shorter doubling time and a significantly higher expression of stemness genes (p < 0.05), and (iii) LPCs secreted significantly higher levels (p < 0.05) of cytokines related to chronic inflammation and significantly lower amounts (p < 0.05) of cytokines related to acute inflammation. Despite the limited sample size, comparisons between leiomyoma and normal myometrium tissue from each patient allowed normalization of patient-specific differences. The evidenced cytokine expression pattern related to chronic inflammation in LPCs may play a role in the increased risk of adverse obstetric outcomes (infertility, spontaneous miscarriage, and preterm birth) in women affected by leiomyomas. These women should be recognized as “high risk” and subjected to specialized management both before and during pregnancy.

Human liver organoids generated with single donor-derived multiple cells rescue mice from acute liver failure

BACKGROUND

Acute liver failure (ALF) is a life-threatening disease with a high mortality rate. However, there are limited treatments or devices available for ALF therapy. Here, we aimed to develop a new strategy for ALF treatment by transplanting functional liver organoids (LOs) generated from single donor-derived human induced pluripotent stem cell (hiPSC) endoderm, endothelial cells (ECs), and mesenchymal cells (MCs).

METHODS

First, we isolated ECs and MCs from a single donor umbilical cord (UC) through enzyme digestion and characterized the UC-ECs and UC-MCs by flow cytometry. Second, using a nonviral reprogramming method, we generated same donor-derived hiPSCs from the UC-ECs and investigated their hepatic differentiation abilities. Finally, we simultaneously plated EC-hiPSC endoderm, UC-ECs, and UC-MCs in a three-dimensional (3D) microwell culture system, and generated single donor cell-derived differentiated LOs for ALF mouse treatment.

RESULTS

We obtained ECs and MCs from a single donor UC with high purity, and these cells provided a multicellular microenvironment that promoted LO differentiation. hiPSCs from the same donor were generated from UC-ECs, and the resultant EC-hiPSCs could be differentiated efficiently into pure definitive endoderm and further into hepatic lineages. Simultaneous plating of EC-hiPSC endoderm, UC-ECs, and UC-MCs in the 3D microwell system generated single donor cell-derived LOs (SDC-LOs) that could be differentiated into functional LOs with enhanced hepatic capacity as compared to that of EC-hiPSC-derived hepatic-like cells. When these functional SDC-LOs were transplanted into the renal subcapsules of ALF mice, they rapidly assumed hepatic functions and improved the survival rate of ALF mice.

CONCLUSION

These results demonstrate that functional LOs generated from single donor cells can improve the condition of ALF mice. Functional SDC-LO transplantation provides a promising novel approach for ALF therapy.

Identification of new genes associated to senescent and tumorigenic phenotypes in mesenchymal stem cells

Although human mesenchymal stem cells (hMSCs) are a powerful tool for cell therapy, prolonged culture times result in replicative senescence or acquisition of tumorigenic features. To identify a molecular signature for senescence, we compared the transcriptome of senescent and young hMSCs with normal karyotype (hMSCs/n) and with a constitutional inversion of chromosome 3 (hMSC/inv). Senescent and young cells from both lineages showed differentially expressed genes (DEGs), with higher levels in senescent hMSCs/inv. Among the 30 DEGs in senescent hMSC/inv, 11 are new candidates for biomarkers of cellular senescence. The functional categories most represented in senescent hMSCs were related to cellular development, cell growth/proliferation, cell death, cell signaling/interaction, and cell movement. Mapping of DEGs onto biological networks revealed matrix metalloproteinase-1, thrombospondin 1, and epidermal growth factor acting as topological bottlenecks. In the comparison between senescent hMSCs/n and senescent hMSCs/inv, other functional annotations such as segregation of chromosomes, mitotic spindle formation, and mitosis and proliferation of tumor lines were most represented. We found that many genes categorized into functional annotations related to tumors in both comparisons, with relation to tumors being highest in senescent hMSCs/inv. The data presented here improves our understanding of the molecular mechanisms underlying the onset of cellular senescence as well as tumorigenesis.

Mesenchymal Stem Cells in Kidney Repair

Every year 13.3 million people suffer acute kidney injury (AKI), which is associated with a high risk of death or development of long-term chronic kidney disease (CKD) in a substantial percentage of patients besides other organ dysfunctions. To date, the mortality rate per year for AKI exceeds 50 % at least in patients requiring early renal replacement therapy and is higher than the mortality for breast and prostate cancer, heart failure and diabetes combined.Until now, no effective treatments able to accelerate renal recovery and improve survival post AKI have been developed. In search of innovative and effective strategies to foster the limited regeneration capacity of the kidney, several studies have evaluated the ability of mesenchymal stem cells (MSCs) of different origin as an attractive therapeutic tool. The results obtained in several models of AKI and CKD document that MSCs have therapeutic potential in repair of renal injury, preserving renal function and structure thus prolonging animal survival through differentiation-independent pathways. In this chapter, we have summarized the mechanisms underlying the regenerative processes triggered by MSC treatment, essentially due to their paracrine activity. The capacity of MSC to migrate to the site of injury and to secrete a pool of growth factors and cytokines with anti-inflammatory, mitogenic, and immunomodulatory effects is described. New modalities of cell-to-cell communication via the release of microvesicles and exosomes by MSCs to injured renal cells will also be discussed. The translation of basic experimental data on MSC biology into effective care is still limited to preliminary phase I clinical trials and further studies are needed to definitively assess the efficacy of MSC-based therapy in humans.

Coenzyme Q10 promotes osteoblast proliferation and differentiation and protects against ovariectomy-induced osteoporosis

Coenzyme Q10 (CoQ10) is a fat‑soluble vitamin‑like substance used for the treatment of a variety of disorders, including osteoporosis. The exact mechanism underlying CoQ10‑mediated protection against osteoporosis remains to be elucidated. The present study aimed to evaluate the effect of CoQ10 on osteoblastic cell proliferation and differentiation, and therapeutic effects on a rat model of osteoporosis. Following treatment with different concentrations of CoQ10, cell proliferation and differentiation of rat bone marrow stromal cells (BMSCs), and expression of osteoblastogenic markers, were measured. Rats with osteoporosis subjected to ovariectomy (OVX) were treated with different concentrations of CoQ10. Serum levels of estrogen and bone metabolism markers were measured. Micro computed tomography scans were used to analyze morphological changes in bones. In addition, mRNA and protein levels of phosphatidylinositol 3,4,5‑trisphosphate 3‑phosphatase and dual‑specificity protein phosphatase PTEN (PTEN)/phosphatidylinositol 4,5‑bisphosphate 3‑kinase (PI3K)/RAC‑alpha serine/threonine‑protein kinase(AKT), were determined. CoQ10 significantly increased the proliferation and osteogenic differentiation of BMSCs in a dose‑dependent manner, with an increased expression of osteogenic markers. CoQ10 significantly decreased bone resorption but exhibited no effect on serum E2 levels in vivo. CoQ10 markedly enhanced bone formation. Furthermore, the abundance of p‑PI3K and p‑AKT increased while PTEN levels decreased in a dose‑dependent manner following administration of CoQ10. CoQ10 stimulates the proliferation and differentiation of BMSCs and is effective for the treatment of OVX‑induced osteoporosis in rats. The above effects of CoQ10 may be mediated by activation of the PTEN/PI3K/AKT pathway.

DSP30 enhances the immunosuppressive properties of mesenchymal stromal cells and protects their suppressive potential from lipopolysaccharide effects: A potential role of adenosine

Multipotent mesenchymal stromal cells (MSC) are imbued with an immunosuppressive phenotype that extends to several immune system cells. In this study, we evaluated how distinct Toll-like receptor (TLR) agonists impact immunosuppressive properties of bone marrow (BM)-MSC and explored the potential mechanisms involved. We show that TLR4 stimulation by lipopolysaccharide (LPS) restricted the ability of MSC to suppress the proliferation of T lymphocytes, increasing the gene expression of interleukin (IL)-1β and IL-6. In contrast, stimulation of TLR9 by DSP30 induced proliferation and the suppressive potential of BM-MSC, coinciding with reducing tumor necrosis factor (TNF)-α expression, increased expression of transforming growth factor (TGF)-β1, increased percentages of BM-MSC double positive for the ectonucleotidases CD39+CD73+ and adenosine levels. Importantly, following simultaneous stimulation with LPS and DSP30, BM-MSC's ability to suppress T lymphocyte proliferation was comparable with that of non-stimulated BM-MSC levels. Moreover, stimulation of BM-MSC with LPS reduced significantly the gene expression levels, on co-cultured T lymphocyte, of IL-10 and interferon (IFN)γ, a cytokine with potential to enhance the immunosuppression mediated by MSC and ameliorate the clinical outcome of patients with graft-versus-host disease (GVHD). Altogether, our findings reiterate the harmful effects of LPS on MSC immunosuppression, besides indicating that DSP30 could provide a protective effect against LPS circulating in the blood of GVHD patients who receive BM-MSC infusions, ensuring a more predictable immunosuppressive effect. The novel effects and potential mechanisms following the stimulation of BM-MSC by DSP30 might impact their clinical use, by allowing the derivation of optimal "licensing" protocols for obtaining therapeutically efficient MSC.

Effects of Mesenchymal Stem Cell Derivatives on Hematopoiesis and Hematopoietic Stem Cells

Hematopoiesis is a balance among quiescence, self-renewal, proliferation, and differentiation, which is believed to be firmly adjusted through interactions between hematopoietic stem and progenitor cells (HSPCs) with the microenvironment. This microenvironment is derived from a common progenitor of mesenchymal origin and its signals should be capable of regulating the cellular memory of transcriptional situation and lead to an exchange of stem cell genes expression. Mesenchymal stem cells (MSCs) have self-renewal and differentiation capacity into tissues of mesodermal origin, and these cells can support hematopoiesis through release various molecules that play a crucial role in migration, homing, self-renewal, proliferation, and differentiation of HSPCs. Studies on the effects of MSCs on HSPC differentiation can develop modern solutions in the treatment of patients with hematologic disorders for more effective Bone Marrow (BM) transplantation in the near future. However, considerable challenges remain on realization of how paracrine mechanisms of MSCs act on the target tissues, and how to design a therapeutic regimen with various paracrine factors in order to achieve optimal results for tissue conservation and regeneration. The aim of this review is to characterize and consider the related aspects of the ability of MSCs secretome in protection of hematopoiesis.

Transplant of Hepatocytes, Undifferentiated Mesenchymal Stem Cells, and In Vitro Hepatocyte-Differentiated Mesenchymal Stem Cells in a Chronic Liver Failure Experimental Model: A Comparative Study

OBJECTIVES

Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure.

MATERIALS AND METHODS

Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed.

RESULTS

Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group.

CONCLUSIONS

Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.

Inhibition of IGF-1 receptor kinase blocks the differentiation into cardiomyocyte-like cells of BMSCs induced by IGF-1

Bone marrow mesenchymal stem cells (BMSCs) have the potential to transdifferentiate into cardiomyocyte-like cells (CLCs) if an appropriate cardiac environment is provided. Insulin-like growth factor-1 (IGF-1) plays an important role in the cell migration, survival and differentiation of BMSCs. However, the effect of IGF-1 on the cellular differentiation remains unclear. In the present study, BMSCs were isolated from rat femurs and tibias and the cells were purified at passage 6 (P6). IGF-1 and IGF-1 receptor (IGF-1R) kinase inhibitor I-OMe AG538 were added to detect if IGF-1 could induce BMSCs to transdifferentiate into CLCs and if I-OMe AG538 could inhibit IGF-1-mediated receptor activation and downstream signaling. Immunostaining demonstrated that all P6 BMSCs express CD29 and CD44 but not CD45. BMSCs induced by 15 ng/ml IGF-1 revealed positivity for cardiac troponin-T and cardiac troponin-I. The optimal induction time was 14 days but the expression of these proteins were incompletely inhibited by 300 nmol/l I-OMe AG538 and completely inhibited by 10 µmol/l I-OMe AG538. Western blotting showed that the level of IGF-1R autophosphorylation and the expression of cTnT and cTnI were higher when BMSCs were induced for 14 days. I-OMe AG538 selectively inhibited IGF-1-mediated growth and signal transduction and the inhibitory effect of I-OMe AG538 were not reverted in the presence of exogenous IGF-1. In addition, when a time course analysis of the effects of I-OMe AG538 on mitogen-activated protein kinase kinase and phosphatidylinositol 3-kinase signaling were done, we observed a transient inhibitory effect on Erk1/2 and Akt phosphorylation, in keeping with the inhibitory effects on cell growth. Taken together, these data indicate that I-OMe AG538 could inhibit IGF-1-induced CLCs in BMSCs and this effect is time- and concentration-dependent.

Therapeutic Effects of Human Umbilical Cord-Derived Mesenchymal Stem Cells in Acute Lung Injury Mice

The incidence and mortality of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) are still very high, but stem cells show some promise for its treatment. Here we found that intratracheal administration of human umbilical cord-mesenchymal stem cells (UC-MSCs) significantly improved survival and attenuated the lung inflammation in lipopolysaccharide (LPS)-induced ALI mice. We also used the proteins-chip and bioinformatics to analyze interactions between UC-MSCs treatment and immune-response alternations of ALI mice. Then we demonstrated that UC-MSCs could inhibit the inflammatory response of mouse macrophage in ALI mice, as well as enhance its IL-10 expression. We provide data to support the concept that the therapeutic capacity of UC-MSCs for ALI was primarily through paracrine secretion, particularly of prostaglandin-E2 (PGE2). Furthermore, we showed that UC-MSCs might secrete a panel of factors including GM-CSF, IL-6 and IL-13 to ameliorate ALI. Our study suggested that UC-MSCs could protect LPS-induced ALI model by immune regulation and paracrine factors, indicating that UC-MSCs should be a promising strategy for ALI/ARDS.

Follicular lymphoma (FL): Immunological tolerance theory in FL

The ultimate cause of follicular lymphoma (FL) remains unknown. Remarkably, almost nothing is known about immunological tolerance mechanisms that might contribute to FL development. Immunological tolerance mechanisms, like other stimuli, also induce persistent changes of B cell receptors that induce genetic instability and molecular aberrations promoting the development of a neoplasm. Using the same method as Burnet, we provide a new perspective taking advantage of the comparison of a normal linear B cell differentiation process and FL development within the framework of clonal selection theory. We propose that FL is a malignancy of cells that acquire both translocation t(14;18) and self-BCR, inducing them to proliferate and mature, resistant to negative selection. Additional genetic damage induced by non-apoptotic tolerance mechanisms, such as receptor editing, may transform a self-reactive B cell with t(14;18) into an FL. The result of tolerogenic mechanisms and genetic aberrations is the survival of FL B cell clones with similar markers and homogenous gene expression signatures despite the different stages of maturation at which the molecular damage occurs. To antagonize further growth advantage due to self-antigen recognition and chronic activation of tolerance mechanisms in the apoptosis-resistant background of FL B cells, inhibitors of BCR signaling may be promising therapeutic options.

Matrix directed adipogenesis and neurogenesis of mesenchymal stem cells derived from adipose tissue and bone marrow

Mesenchymal stem cells (MSCs) can differentiate into multiple lineages through guidance from the biophysical and biochemical properties of the extracellular matrix. In this work we conduct a combinatorial study of matrix properties that influence adipogenesis and neurogenesis including: adhesion proteins, stiffness, and cell geometry, for mesenchymal stem cells derived from adipose tissue (AT-MSCs) and bone marrow (BM-MSCs). We uncover distinct differences in integrin expression, the magnitude of traction stress, and lineage specification to adipocytes and neuron-like cells between cell sources. In the absence of media supplements, adipogenesis in AT-MSCs is not significantly influenced by matrix properties, while the converse is true in BM-MSCs. Both cell types show changes in the expression of neurogenesis markers as matrix cues are varied. When cultured on laminin conjugated microislands of the same adhesive area, BM-MSCs display elevated adipogenesis markers, while AT-MSCs display elevated neurogenesis markers; integrin analysis suggests neurogenesis in AT-MSCs is guided by adhesion through integrin αvβ3. Overall, the properties of the extracellular matrix guides MSC adhesion and lineage specification to different degrees and outcomes, in spite of their similarities in general characteristics. This work will help guide the selection of MSCs and matrix components for applications where high fidelity of differentiation outcome is desired.

STATEMENT OF SIGNIFICANCE

Mesenchymal stem cells (MSCs) are an attractive cell type for stem cell therapies; however, in order for these cells to be useful in medicine, we need to understand how they respond to the physical and chemical environments of tissue. Here, we explore how two promising sources of MSCs-those derived from bone marrow and from adipose tissue-respond to the compliance and composition of tissue using model extracellular matrices. Our results demonstrate a source-specific propensity to undergo adipogenesis and neurogenesis, and uncover a role for adhesion, and the degree of traction force exerted on the substrate in guiding these lineage outcomes.

Mesenchymal stem cells for tendon healing: what is on the horizon?

Tendon injuries are a noteworthy morbidity but at present there are few effective scientifically proven treatments. In recent decades, a number of new strategies including tissue engineering with mesenchymal stem cells (MSCs) have been proposed to enhance tendon healing. Although MSCs are an interesting and promising approach, many questions regarding their use in tendon repair remain unanswered. This descriptive overview of the literature of the last decade explores the in vivo studies on tendon healing, in small and large animal models, which used MSCs harvested from different tissues, and the state of the art in clinical applications. It was observed that there are still doubts about the optimum amount of MSCs to use and their source and the type of scaffolds to deliver the cells. Thus, further studies are needed to determine the best protocol for MSC use in tendon healing. Copyright © 2016 John Wiley & Sons, Ltd.

Therapeutic potential of mesenchymal stem cells for pulmonary complications associated with preterm birth

Preterm infants frequently suffer from pulmonary complications resulting in significant morbidity and mortality. Physiological and structural lung immaturity impairs perinatal lung transition to air breathing resulting in respiratory distress. Mechanical ventilation and oxygen supplementation ensure sufficient oxygen supply but enhance inflammatory processes which might lead to the establishment of a chronic lung disease called bronchopulmonary dysplasia (BPD). Current therapeutic options to prevent or treat BPD are limited and have salient side effects, highlighting the need for new therapeutic approaches. Mesenchymal stem cells (MSCs) have demonstrated therapeutic potential in animal models of BPD. This review focuses on MSC-based therapeutic approaches to treat pulmonary complications and critically compares results obtained in BPD models. Thereby bottlenecks in the translational systems are identified that are preventing progress in combating BPD. Notably, current animal models closely resemble the so-called "old" BPD with profound inflammation and injury, whereas clinical improvements shifted disease pathology towards a "new" BPD in which arrest of lung maturation predominates. Future studies need to evaluate the utility of MSC-based therapies in animal models resembling the "new" BPD though promising in vitro evidence suggests that MSCs do possess the potential to stimulate lung maturation. Furthermore, we address the mode-of-action of MSC-based therapies with regard to lung development and inflammation/fibrosis. Their therapeutic efficacy is mainly attributed to an enhancement of regeneration and immunomodulation due to paracrine effects. In addition, we discuss current improvement strategies by genetic modifications or precondition of MSCs to enhance their therapeutic efficacy which could also prove beneficial for BPD therapies.