Characteristics of human umbilical cord mesenchymal stem cells during ex vivo expansion

In Situ-Formed Fibrin Hydrogel Scaffold Loaded With Human Umbilical Cord Mesenchymal Stem Cells Promotes Skin Wound Healing

Healing of full-thickness skin wounds remains a major challenge. Recently, human umbilical cord mesenchymal stem cells (hUC-MSCs) were shown to possess an extraordinary potential to promote skin repair in clinical settings. However, their low survival rate after transplantation limits their therapeutic efficiency in treating full-thickness skin wounds. Hydrogels are considered an ideal cell transplantation vector owing to their three-dimensional mesh structure, good biosafety, and biodegradation. The objective of this study was to investigate the skin wound healing effect of a fibrin hydrogel scaffold loaded with hUC-MSCs. We found that the fibrin hydrogel had a three-dimensional mesh structure and low cytotoxicity and could prolong the time of cell survival in the peri-wound area. The number of green fluorescent protein (GFP)-labeled hUC-MSCs was higher in the full-thickness skin wound of mice treated with hydrogel-hUC-MSCs than those of mice treated with cell monotherapy. In addition, the combination therapy between the hydrogel and hUC-MSCs speed up wound closure, its wound healing rate was significantly higher than those of phosphate-buffered saline (PBS) therapy, hydrogel monotherapy, and hUC-MSCs monotherapy. Furthermore, the results showed that the combination therapy between hydrogel and hUC-MSCs increased keratin 10 and keratin 14 immunofluorescence staining, and upregulated the relative gene expressions of epidermal growth factor (EGF), transforming growth factor-β1 (TGF-β1), and vascular endothelial growth factor A (VEGFA), promoting epithelial regeneration and angiogenesis. In conclusion, the fibrin hydrogel scaffold provides a relatively stable sterile environment for cell adhesion, proliferation, and migration, and prolongs cell survival at the wound site. The hydrogel-hUC-MSCs combination therapy promotes wound closure, re-epithelialization, and neovascularization. It exhibits a remarkable therapeutic effect, being more effective than the monotherapy with hUC-MSCs or hydrogel.

Alginate microspheres-collagen hydrogel, as a novel 3D culture system, enhanced skin wound healing of hUCMSCs in rats model

While stem cell transplantation has emerged as a promising approach to improving wound healing outcomes, the application of stem cells to date has been limited by the poor survival and retention of these cells once transplanted. The survival, development, and migratory activity of transplanted cells can be improved through the use of three-dimensional (3D) culture systems. Here, a novel alginate microsphere-collage hydrogel (AMS-Col gel) 3D culture system was developed and found to improve human umbilical cord mesenchymal stem cell (hUCMSC) survival, permitting their sustained release so as to promote wound healing. Through hematoxylin and eosin staining and Masson's trichrome staining, the prepared hUCMSCs-AMS-Col gel was found to exhibit wound healing activity. On day 7 following the hUCMSCs-AMS-Col gel treatment of model wounds, improved collagen fiber deposition and re-epithelialization were evident, with complete epithelial regeneration as of day 14 and near-total wound healing was evident as of day 21. This hUCMSCs-AMS-Col gel was also associated with increased VEGF and FGF2 expression. Together, these data indicate that AMS-Col gels are a promising and novel form of 3D cell culture system capable of improving hUCMSC-mediated wound healing, highlighting the potential clinical utility of this regenerative strategy.

Anatomically and Biomechanically Relevant Monolithic Total Disc Replacement Made of 3D-Printed Thermoplastic Polyurethane

Various implant treatments, including total disc replacements, have been tried to treat lumbar intervertebral disc (IVD) degeneration, which is claimed to be the main contributor of lower back pain. The treatments, however, come with peripheral issues. This study proposes a novel approach that complies with the anatomical features of IVD, the so-called monolithic total disc replacement (MTDR). As the name suggests, the MTDR is a one-part device that consists of lattice and rigid structures to mimic the nucleus pulposus and annulus fibrosus, respectively. The MTDR can be made of two types of thermoplastic polyurethane (TPU 87A and TPU 95A) and fabricated using a 3D printing approach: fused filament fabrication. The MTDR design involves two configurations—the full lattice (FLC) and anatomy-based (ABC) configurations. The MTDR is evaluated in terms of its physical, mechanical, and cytotoxicity properties. The physical characterization includes the geometrical evaluations, wettability measurements, degradability tests, and swelling tests. The mechanical characterization comprises compressive tests of the materials, an analytical approach using the Voigt model of composite, and a finite element analysis. The cytotoxicity assays include the direct assay using hemocytometry and the indirect assay using a tetrazolium-based colorimetric (MTS) assay. The geometrical evaluation shows that the fabrication results are tolerable, and the two materials have good wettability and low degradation rates. The mechanical characterization shows that the ABC-MTDR has more similar mechanical properties to an IVD than the FLC-MTDR. The cytotoxicity assays prove that the materials are non-cytotoxic, allowing cells to grow on the surfaces of the materials.

A hybrid hydrogel encapsulating human umbilical cord mesenchymal stem cells enhances diabetic wound healing

BACKGROUND

Diabetic wound is a severe complication of diabetes. Stem cell is considered as a promising therapy for diabetic skin wounds. Hydrogel can supply niche for cells adhesion and survival to improve the efficacy of stem cell therapy, but the development of hydrogel with suitable properties remains a great challenge. Thus, our study was conducted to combine an optimized hydrogel with stem cell to improve complex diabetic wound treatment.

METHODS

This study constructed a hydrogel with low toxicity and adjustable mechanical properties from gelatin methacrylate (GelMA) and chitosan-catechol (Chi-C), and encapsulated human umbilical cord-mesenchymal stem cells (hUMSCs) to repair full-thickness diabetic wound.

RESULTS

We explored the relationship between mechanical stiffness and cell proliferation and differentiation potency, and found 10% GelMA hydrogel with an optimal stiffness improved hUMSCs adhesion, proliferation, and differentiation potency maintenance in vitro. Assistant with optimized hydrogel encapsulating hUMSCs, diabetic wound healing process was greatly accelerated, including accelerated wound closure, inhibited secretion of inflammatory factors TNF-α and IL-1β, promoted vascular regeneration and collagen deposition after treatment of hUMSCs.

CONCLUSIONS

The optimized hydrogel encapsulating hUMSCs improved diabetic wound healing, and has a broad implication for the treatment of diabetic complication. Diabetic wound is a severe complication of diabetes. Stem cell is considered as a promising therapy for diabetic skin wounds. Hydrogel can supply niche for cells adhesion and survival to improve the efficacy of stem cell therapy. This study constructed a hydrogel with low toxicity and adjustable mechanical properties from gelatin methacrylate (GelMA) and chitosan-catechol (Chi-C), and encapsulated human umbilical cord-mesenchymal stem cells (hUMSCs) to repair full-thickness diabetic wound. Hydrogel of 10% GelMA with an optimal stiffness improved hUMSCs adhesion, proliferation, and differentiation potency maintenance in vitro. Assistant with optimized hydrogel encapsulating hUMSCs, diabetic wound healing process was greatly accelerated, including accelerated wound closure, inhibited secretion of inflammatory factors TNF-α and IL-1β, promoted vascular regeneration and collagen deposition after treatment of hUMSCs. The study supplies an alternative treatment for diabetic complication. Hydrogel-hUMSCs combined treatment accelerates wound closure in diabetic mice. A. Representative images of wounds during 21-day in vivo experiments. B. Quantification of wound closure rate (%) over 21-day period. C. HE staining of wounds at days 7, 14 and 21. The bar corresponds to 200 μm.

Conditioned medium derived from bovine umbilical mesenchymal stem cells as an alternative source of cell-free therapy

Umbilical cord blood (UCB) cells are an important source of mesenchymal stem cells (MSCs). It is known that the umbilical cord is rich in hematopoietic stem cells, which influenced research on ontogeny and transplantation (allogeneic transplantation). In recent years, stem cell research has emerged as an area of major interest due to its prospective applications in various aspects of both human and veterinary medicine. Moreover, it is known that the application of MSCs has several weaknesses. The use of these cells has limitations in terms of tumorigenesis effect, delivery, safety, and variability of therapeutic response, which led to the use of secretomes as an alternative to cell-free therapy. The main obstacle in its use is the availability of human UCB as an origin of MSCs and MSCs’ secretomes, which are often difficult to obtain. Ethical issues regarding the use of stem cells based on human origin are another challenge, so an alternative is needed. Several studies have demonstrated that MSCs obtained from bovine umbilical cords have the same properties and express the same surface markers as MSCs obtained from human umbilical cords. Therefore, secretomes from MSCs derived from domestic animals (bovine) can possibly be used in human and veterinary medicine. This finding would contribute significantly to improve cell-free therapy. At present, the use of UCB MSCs derived from domestic animals, especially bovines, is very restricted, and only limited data about bovine UCB are available. Therefore, the aim of this review was to provide an updated overview of cell-free therapy and discuss the new possibilities introduced by the generation of this therapy derived from bovine umbilical MSCs as a promising tool in developing modern and efficient treatment strategies.

Alopecia treatment using minimally manipulated human umbilical cord-derived mesenchymal stem cells: Three case reports and review of literature

BACKGROUND

Alopecia areata (AA) is a common autoimmune disease characterized by hair loss. AA appears in extensive forms, such as progressive and diffusing hair loss (diffuse AA), a total loss of scalp hair (alopecia totalis), and complete loss of hair over the entire body (alopecia universalis). Recently, mesenchymal stem cells (MSCs) have been identified as a therapeutic alternative for autoimmune diseases. For this reason, preclinical and case studies of AA and related diseases using MSCs have been conducted.

CASE SUMMARY

Case 1: A 55-year-old woman suffered from AA in two areas of the scalp. She was given 15 rounds of minimally manipulated umbilical cord-MSCs (MM-UC-MSCs) over 6 mo. The AA gradually improved 3 mo after the first round. The patient was cured, and AA did not recur. Case 2: A 30-year-old woman, with history of local steroid hormone injections, suffered from AA in one area on the scalp. She was given two rounds of MM-UC-MSCs over 1 mo. The AA immediately improved after the first round. The patient was cured, and AA did not recur. Case 3: A 20-year-old woman, who was diagnosed with alopecia universalis at the age of 12, was given 14 rounds of MM-UC-MSCs over 12 mo. Her hair began to grow about 3 mo after the first round. The patient was cured, and alopecia universalis did not recur.

CONCLUSION

MM-UC-MSC transplantation potentially treats patients who suffer from AA and related diseases.

Intra-articular injection of human umbilical cord mesenchymal stem cells ameliorates monosodium iodoacetate-induced osteoarthritis in rats by inhibiting cartilage degradation and inflammation

Aims

This study aimed to investigate whether human umbilical cord mesenchymal stem cells (UC-MSCs) can prevent articular cartilage degradation and explore the underlying mechanisms in a rat osteoarthritis (OA) model induced by monosodium iodoacetate (MIA).

Methods

Human UC-MSCs were characterized by their phenotype and multilineage differentiation potential. Two weeks after MIA induction in rats, human UC-MSCs were intra-articularly injected once a week for three weeks. The therapeutic effect of human UC-MSCs was evaluated by haematoxylin and eosin, toluidine blue, Safranin-O/Fast green staining, and Mankin scores. Markers of joint cartilage injury and pro- and anti-inflammatory markers were detected by immunohistochemistry.

Results

Histopathological analysis showed that intra-articular injection of human UC-MSCs significantly inhibited the progression of OA, as demonstrated by reduced cartilage degradation, increased Safranin-O staining, and lower Mankin scores. Immunohistochemistry showed that human UC-MSC treatment down-regulated the expression of matrix metalloproteinase-13 (MMP13) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), and enhanced the expression of type II collagen and ki67 in the articular cartilage. Furthermore, human UC-MSCs significantly decreased the expression of interleukin (IL)-1β and tumour necrosis factor-α (TNF-α), while increasing TNF-α-induced protein 6 and IL-1 receptor antagonist.

Conclusion

Our results demonstrated that human UC-MSCs ameliorate MIA-induced OA by preventing cartilage degradation, restoring the proliferation of chondrocytes, and inhibiting the inflammatory response, which implies that human UC-MSCs may be a promising strategy for the treatment of OA.

Cite this article: Bone Joint Res 2021;10(3):226–236.

Repeated subarachnoid administrations of allogeneic human umbilical cord mesenchymal stem cells for spinal cord injury: a phase 1/2 pilot study

BACKGROUND AIMS

Stem cell transplantation is a potential treatment for intractable spinal cord injury (SCI), and allogeneic human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising candidate because of the advantages of immune privilege, paracrine effect, immunomodulatory function, convenient collection procedure and little ethical concern, and there is an urgent need to develop a safe and effective protocol regarding their clinical application.

METHODS

A prospective, single-center, single-arm study in which subjects received four subarachnoid transplantations of hUC-MSCs (1 × 10⁶ cells/kg) monthly and were seen in follow-up four times (1, 3, 6 and 12 months after final administration) was conducted. At each scheduled time point, safety and efficacy indicators were collected and analyzed accordingly. Adverse events (AEs) were used as a safety indicator. American Spinal Injury Association (ASIA) and SCI Functional Rating Scale of the International Association of Neurorestoratology (IANR-SCIFRS) total scores at the fourth follow-up were determined as primary efficacy outcomes, whereas these two indicators at the remaining time points as well as scores of pinprick, light touch, motor and sphincter, muscle spasticity and spasm, autonomic system, bladder and bowel functions, residual urine volume (RUV) and magnetic resonance imaging (MRI) were secondary efficacy outcomes. Subgroup analysis of primary efficacy indicators was also performed.

RESULTS

Safety and efficacy assessments were performed on 102 and 41 subjects, respectively. Mild AEs involving fever (14.1%), headache (4.2%), transient increase in muscle tension (1.6%) and dizziness (1.3%) were observed following hUC-MSC transplantation and resolved thoroughly after conservative treatments. There was no serious AE. ASIA and IANR-SCIFRS total scores revealed statistical increases when compared with the baselines at different time points during the study, mainly reflected in the improvement of pinprick, light touch, motor and sphincter scores. Moreover, subjects showed a continuous and remarkable decrease in muscle spasticity. Regarding muscle spasm, autonomic system, bladder and bowel functions, RUV and MRI, data/imaging at final follow-up showed significant improvements compared with those at first collection. Subgroup analysis found that hUC-MSC transplantation improved neurological functions regardless of injury characteristics, including level, severity and chronicity.

CONCLUSIONS

The authors' present protocol demonstrates that intrathecal administration of' allogeneic hUC-MSCs at a dose of 10⁶ cells/kg once a month for 4 months is safe and effective and leads to significant improvement in neurological dysfunction and recovery of quality of life.

Effects of degradable magnesium on paracrine signaling between human umbilical cord perivascular cells and peripheral blood mononuclear cells

Human mesenchymal stem cells (MSC) interact with numerous immune cells that can promote regenerative processes and inhibit inflammatory responses. We hypothesised that the cross-talk between human umbilical cord perivascular cells (HUCPV; an alternative source of MSC) and peripheral blood mononuclear cells (PBMC) could be influenced by degradable transwell magnesium (Mg). To study the correlations between paracrine signaling and specific cellular behaviour during the host response to Mg, we used a transwell coculture system for up to 7 days. The proliferation and viability of both cell types were not significantly influenced by Mg. When HUCPV were cultured with degradable Mg, a moderate inflammation (e.g., lower secretions of pro-inflammatory interleukin 1 beta and IL2, and tumour necrosis factor alpha, interferon gamma, anti-inflammatory interleukins 4, 5, 10, 13, and 1 receptor antagonists and granulocyte colony stimulating factor), and an increased pro-healing M2 macrophage phenotype were observed. Moreover, when PBMC were cultured with degradable Mg, the expression of migration/wound healing related cytokines (interleukin 8, granulocyte-macrophage colony-stimulating factor, monocyte chemoattractant protein 1 and macrophage inflammatory protein 1α/β) was upregulated, accompanied by an increase in the migration ability of HUCPV (cell scratch assay). In addition, an increased pro-osteogenic potential was demonstrated via an increase of osteoblastic markers (e.g., alkaline phosphatase activity, specific gene expression and cytokine release). These results collectively imply that Mg possesses osteo-immunomodulatory properties. They also help to design Mg-based bone substitute biomaterials capable of exhibiting desired immune reactions and good clinical performance.

Involvement of P2X7 Receptors in the Osteogenic Differentiation of Mesenchymal Stromal/Stem Cells Derived from Human Subcutaneous Adipose Tissue

The ionotropic P2X7 receptor (P2X7R) is involved in bone homeostasis but its role in osteogenesis is controversial. Thus, we investigated the expression of P2X7R and the effects exerted by its modulation in mesenchymal stromal cells from human subcutaneous adipose tissue (S-ASCs), which have potential therapeutic application in bone regenerative medicine. We found that undifferentiated S-ASCs expressed P2X7R and its functional splice variants P2X7AR and P2X7BR. Cell stimulation by P2X7R agonist BzATP (100 μM) neither modified proliferation nor caused membrane pore opening while increasing intracellular Ca²⁺ levels and migration. The P2X7R antagonist A438079 reversed these effects. However, 25-100 μM BzATP, administered to S-ASCs undergoing osteogenic differentiation, dose-dependently decreased extracellular matrix mineralization and expression of osteogenic transcription factors Runx2, alkaline phosphatase and osteopontin. These effects were not coupled to cell proliferation reduction or to cell death increase, but were associated to decrease in P2X7AR and P2X7BR expression. In contrast, expression of P2X7R, especially P2X7BR isoform, significantly increased during the osteogenic process. Noteworthy, the antagonist A438079, administered alone, at first restrained cell differentiation, enhancing it later. Accordingly, A438079 reversed BzATP effects only in the second phase of S-ASCs osteogenic differentiation. Apyrase, a diphosphohydrolase converting ATP/ADP into AMP, showed a similar behavior. Altogether, findings related to A438079 or apyrase effects suggest an earlier and prevailing pro-osteogenic activity by endogenous ATP and a later one by adenosine derived from endogenous ATP metabolism. Conversely, P2X7R pharmacological stimulation by BzATP, mimicking the effects of high ATP levels occurring during tissue injuries, depressed receptor expression/activity impairing MSC osteogenic differentiation.

Adult mesenchymal stem cells: is there a role for purine receptors in their osteogenic differentiation?

The role played by mesenchymal stem cells (MSCs) in contributing to adult tissue homeostasis and damage repair thanks to their differentiation capabilities has raised a great interest, mainly in bone regenerative medicine. The growth/function of these undifferentiated cells of mesodermal origin, located in specialized structures (niches) of differentiated organs is influenced by substances present in this microenvironment. Among them, ancestral and ubiquitous molecules such as adenine-based purines, i.e., ATP and adenosine, may be included. Notably, extracellular purine concentrations greatly increase during tissue injury; thus, MSCs are exposed to effects mediated by these agents interacting with their own receptors when they act/migrate in vivo or are transplanted into a damaged tissue. Here, we reported that ATP modulates MSC osteogenic differentiation via different P2Y and P2X receptors, but data are often inconclusive/contradictory so that the ATP receptor importance for MSC physiology/differentiation into osteoblasts is yet undetermined. An exception is represented by P2X7 receptors, whose expression was shown at various differentiation stages of bone cells resulting essential for differentiation/survival of both osteoclasts and osteoblasts. As well, adenosine, usually derived from extracellular ATP metabolism, can promote osteogenesis, likely via A2B receptors, even though findings from human MSCs should be implemented and confirmed in preclinical models. Therefore, although many data have revealed possible effects caused by extracellular purines in bone healing/remodeling, further studies, hopefully performed in in vivo models, are necessary to identify defined roles for these compounds in favoring/increasing the pro-osteogenic properties of MSCs and thereby their usefulness in bone regenerative medicine.

Umbilical Cord-Derived Mesenchymal Stem Cells Ameliorate Nephrocyte Injury and Proteinuria in a Diabetic Nephropathy Rat Model

Mesenchymal stem cells (MSCs) are shown to alleviate renal injury of diabetic nephropathy (DN) in rats. However, the underlying mechanism of this beneficial effect is not fully understood. The aims of this study are to evaluate effects of umbilical cord-derived mesenchymal stem cells (UC-MSCs) on renal cell apoptosis in streptozotocin- (STZ-) induced diabetic rats and explore the underlying mechanisms. Characteristics of UC-MSCs were identified by flow cytometry and differentiation capability. Six weeks after DN induction by STZ injection in Sprague-Dawley rats, the DN rats received UC-MSCs once a week for consecutive two weeks. DN-related physical and biochemical parameters were measured at 2 weeks after UC-MSC infusion. Renal histological changes were also assessed. Moreover, the apoptosis of renal cells and expression of apoptosis-related proteins were evaluated. Compared with DN rats, rats treated with UC-MSCs showed suppressed increase in 24-hour urinary total protein, urinary albumin to creatinine ratio, serum creatinine, and blood urea nitrogen. UC-MSC treatment ameliorated pathological abnormalities in the kidney of DN rats as evidenced by H&E, PAS, and Masson Trichrome staining. Furthermore, UC-MSC treatment reduced apoptosis of renal cells in DN rats. UC-MSCs promoted expression of antiapoptosis protein Bcl-xl and suppressed expression of high mobility group protein B1 (HMGB1) in the kidney of DN rats. Most importantly, UC-MSCs suppressed upregulation of thioredoxin-interacting protein (TXNIP), downregulation of thioredoxin 1 (TRX1), and activation of apoptosis signal-regulating kinase 1 (ASK1) and P38 MAPK in the kidney of DN rats. Our results suggest that UC-MSCs could alleviate nephrocyte injury and albuminuria of DN rats through their antiapoptotic property. The protective effects of UC-MSCs may be mediated by inhibiting TXNIP upregulation in part.

Human umbilical cord-derived mesenchymal stem cells conditioned medium attenuate interstitial fibrosis and stimulate the repair of tubular epithelial cells in an irreversible model of unilateral ureteral obstruction

AIM

The growing number of patients suffering from chronic renal disease (CKD) is a challenge for the development of innovative therapies. Researchers have studied the therapeutic effects of cell therapy in acute kidney injury (AKI). However, the therapeutic effect of conditional medium (CM) in the CKD models have been rarely reported. Here, we examined the effects of umbilical cord derived-mesenchymal stem cells (hUC-MSCs) CM on renal fibrosis in a rat model of unilateral ureteral obstruction (UUO).

METHODS

Animals were randomly divided into three groups: sham-operated, UUO, UUO + CM. CM was administered via the left renal artery after total ligation of the left ureter. Rats were killed after 14 days of obstruction. Histological changes and oxidative stress parameters were assessed. Western blotting and immunohistochemistry analysis were used to measure epithelial-mesenchymal transition (EMT) markers, including epithelial cadherin (E-cadherin), α-smooth muscle actin (α-SMA), tumour necrosis factor-α (TNF-α), Collagen-I, and transforming growth factor β1 (TGF-β1). Proliferation and apoptosis of renal tubular epithelial cells (RTEs) were also measured.

RESULTS

HucMSC-CM significantly reduced the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), and increased the activity of glutathione (GSH) induced by UUO. Moreover, CM significantly reduced the expression of TGF-β1, α-SMA, TNF-α and Collagen-I in UUO kidney, promoted the proliferation of RTEs and inhibited its apoptosis. In addition, the increased expression of E-cadherin also reflects the effective improvement of renal interstitial fibrosis.

CONCLUSION

This study shows that CM protects UUO-induced kidney damage and therefore could be a potential tool to prevent CKD progression.

Enhanced cutaneous wound healing by functional injectable thermo-sensitive chitosan-based hydrogel encapsulated human umbilical cord-mesenchymal stem cells

Human umbilical cord-mesenchymal stem cells (hUCMSCs) can secrete a variety of cytokines and growth factors promoting wound repair. Hydrogel is suitable biomaterial to supply niche for cells adhesion and survival. This study constructed a functional injectable thermo-sensitive hydrogel (chitosan/glycerol phosphate sodium/cellulose nanocrystals, CS/GP/CNC) encapsulated hUCMSCs to repair full-thickness cutaneous wound. Addition of CNC to the CS/GP system not only accelerated the gel speed, but also greatly improved the mechanical properties of the gel and decreased degradation rate. The novel hydrogel was injectable and low toxicity. Histological detection showed that hydrogel-hUCMSCs combination significantly accelerated wound closure, microcirculation, tissue remodeling, re-epithelialization and hair follicle regeneration, and inhibited over-inflammation in the central and surrounding wounds. The hydrogel-hUCMSCs combination promoted collagen deposition and keratinocyte mature marker K1 expression, decreased inflammatory factors secretion namely TNF-α and IL-1β. The present data provides a potential strategy for treatment of non-healing chronic cutaneous wounds.

Human Umbilical Cord Mesenchymal Stem Cells Alleviate Myocardial Endothelial-Mesenchymal Transition in a Rat Dilated Cardiomyopathy Model

BACKGROUND

Human umbilical cord-derived mesenchymal stem cells (HuMSCs) have been shown to suppress cardiac fibrosis; however, the underlying mechanisms are not fully understood. Recent studies have shown that endothelial-mesenchymal transition (EndMT) plays a crucial part in myocardial fibrosis. In the present study, we investigated the suppressive role of HuMSCs in cardiac fibrosis and related mechanisms in a rat dilated cardiomyopathy (DCM) model.

METHODS

Male Lewis rats were randomly divided into 3 groups. Rats without any treatment served as a negative control group, while the DCM rats, which were generated by immunization with porcine myosin, were divided into 2 groups: a HuMSC group, in which HuMSCs (1 × 10⁶ cells/rat) were injected intravenously, and a vehicle group, in which rats were injected with volume-matched solution containing no HuMSCs. Histologic and immunofluorescent measurements were used to evaluate the effects of HuMSCs on cardiac fibrosis and EndMT.

RESULTS

We observed a significant increase in myocardial fibrosis, and elevated EndMT in rats of the vehicle group were observed compared with those in the negative control group along with the increased activity of transforming growth factor (TGF)-β1/extracellular signal-regulated kinase (ERK) 1/2 signaling. Treatment with HuMSCs repressed the increase in myocardial fibrosis and EndMT observed in DCM rats, which correlated with decreased activity of TGF-β1/ERK1/2 signaling.

CONCLUSION

The HuMSCs attenuated cardiac fibrosis at least partly through the inhibition of TGF-β/ERK-induced EndMT.