Enhancing insulin sensitivity in type 2 diabetes mellitus using apelin-loaded small extracellular vesicles from Wharton's jelly-derived mesenchymal stem cells: a novel therapeutic approach

BACKGROUND

Type 2 diabetes mellitus (T2DM), characterized by β-cell dysfunction and insulin resistance (IR), presents considerable treatment challenges. Apelin is an adipocyte-derived factor that shows promise in improving IR; however, it is limited by poor targeting and a short half-life. In the present study, engineered small extracellular vesicles (sEVs) derived from Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) loaded with apelin were used to address the limitations of the therapeutic application of apelin.

METHODS

WJ-MSCs were transduced to obtain engineered sEVs loaded with overexpressed apelin (apelin-MSC-sEVs) and the control sEVs (MSC-sEVs). T2DM mice were injected with apelin-MSC-sEVs and MSC-sEVs, and blood glucose monitoring, glucose and insulin tolerance tests, confocal microscopy, and immunocytochemical analysis were performed. IR models of 3T3-L1 adipocytes were employed to detect GLUT4 expression in each group using western blotting; the affected pathways were determined by measuring the changes in Akt and AMPK signaling and phosphorylation.

RESULTS

Upon successful engineering, WJ-MSCs demonstrated significant overexpression of apelin. The genetic modification did not adversely impact the characteristics of sEVs, ranging from surface protein markers, morphology, to particle size, but generated apelin-overexpressed sEVs. Apelin-MSC-sEVs treatment resulted in notable enhancement of Akt and AMPK pathway activities within 3T3-L1 adipocytes and adipose tissues of T2DM mice. Furthermore, the apelin-loaded sEVs significantly reduced plasma glucose levels, increased pancreatic β-cell proliferation, improved insulin and glucose tolerance, and modulated pro-inflammatory cytokine profiles, compared to mice treated with the control sEVs.

CONCLUSION

Our study developed novel genetically engineered apelin-loaded sEVs derived from WJ-MSCs, and demonstrated their potent role in augmenting insulin sensitivity and regulating inflammatory responses, highlighting their therapeutic promise in T2DM management. The findings open new avenues for the development of clinically viable treatments for T2DM in humans using the apelin-loaded sEVs.

Carbonised Human Hair Incorporated in Agar/KGM Bioscaffold for Tissue Engineering Application: Fabrication and Characterisation

Carbon derived from biomass waste usage is rising in various fields of application due to its availability, cost-effectiveness, and sustainability, but it remains limited in tissue engineering applications. Carbon derived from human hair waste was selected to fabricate a carbon-based bioscaffold (CHAK) due to its ease of collection and inexpensive synthesis procedure. The CHAK was fabricated via gelation, rapid freezing, and ethanol immersion and characterised based on their morphology, porosity, Fourier transforms infrared (FTIR), tensile strength, swelling ability, degradability, electrical conductivity, and biocompatibility using Wharton’s jelly-derived mesenchymal stem cells (WJMSCs). The addition of carbon reduced the porosity of the bioscaffold. Via FTIR analysis, the combination of carbon, agar, and KGM was compatible. Among the CHAK, the 3HC bioscaffold displayed the highest tensile strength (62.35 ± 29.12 kPa). The CHAK also showed excellent swelling and water uptake capability. All bioscaffolds demonstrated a slow degradability rate (<50%) after 28 days of incubation, while the electrical conductivity analysis showed that the 3AHC bioscaffold had the highest conductivity compared to other CHAK bioscaffolds. Our findings also showed that the CHAK bioscaffolds were biocompatible with WJMSCs. These findings showed that the CHAK bioscaffolds have potential as bioscaffolds for tissue engineering applications.

Decreased Inhibition of Proliferation and Induction of Apoptosis in Breast Cancer Cell Lines (T47D and MCF7) from Treatment with Conditioned Medium Derived from Hypoxia-Treated Wharton's Jelly MSCs Compared with Normoxia-Treated MSCs

Background: Mesenchymal stem cells (MSCs) are an appealing source of adult stem cells for cell therapy due to the high rate of proliferation, self-renewal capability, and applicable therapy. Wharton’s jelly (WJ), the main component of the umbilical cord extracellular matrix, comprises multipotent stem cells with a high proliferation rate and self-renewal capability and has anti-cancer properties. MSCs have been reported to secrete a variety of cytokines that have a cytotoxic effect in various cancers. Oxygen tension affects MSCs proliferation, cytokines level but no in surface markers expression, MSCs’ differentiation.

We explored the cytotoxic effect and inducing apoptosis of Wharton’s jelly derived mesenchymal stem cells (WJMSCs) secretions from normoxic WJMSCs (WJMSCs-norCM) (CM: conditioned medium) and hypoxic WJMSCs (WJMSCs-hypoCM) in breast cancer cell lines (T47D and MCF7).

Materials and Methods: Cytotoxic activity was determined using the MTS assay. RT-PCR was performed to measure the expression of apoptosis-inducing genes, specifically P53, BAX, and CASP9, and the antiapoptotic gene BCL-2.

Results: WJMSCs-norCM and WJMSCs-hypoCM were potent inhibitors of the proliferation in both cell lines. WJMSCs-norCM had more anticancer activity in T47D and MCF7. The IC₅₀ value of WJMSCs-norCM on MCF7 was 42.34%, and on T47D was 42.36%. WJMSCs-norCM significantly induced the gene expression of apoptotic P53, BAX, and CASP9 and insignificantly decreased the antiapoptotic gene BCL-2 in both MCF7 and T47D cells. WJMSCs-CM has anticancer activity by inducing P53, BAX, and CASP9 apoptotic genes.

Conclusion: WJMSCs-norCM has more anticancer activity than WJMSCs-hypoCM.

H3K9ac of TGFβRI in human umbilical cord: a potential biomarker for evaluating cartilage differentiation and susceptibility to osteoarthritis via a two-step strategy

Background

Epidemiological investigation and our previous reports indicated that osteoarthritis had a fetal origin and was closely associated with intrauterine growth retardation (IUGR). Human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) could be programmable to “remember” early-life stimuli. Here, we aimed to explore an early-warning biomarker of fetal-originated adult osteoarthritis in the WJ-MSCs.

Methods

Firstly, two kinds of WJ-MSCs were applied to evaluate their chondrogenic potential in vitro through inducing chondrogenic differentiation as the first step of our strategy, one from newborns with IUGR and the other from normal newborns but treated with excessive cortisol during differentiation to simulate the excessive maternal glucocorticoid in the IUGR newborns. As for the second step of the strategy, the differentiated WJ-MSCs were treated with interleukin 1β (IL-1β) to mimic the susceptibility to osteoarthritis. Then, the expression and histone acetylation levels of transforming growth factor β (TGFβ) signaling pathway and the expression of histone deacetylases (HDACs) were quantified, with or without cortisol receptor inhibitor RU486, or HDAC4 inhibitor LMK235. Secondly, the histone acetylation and expression levels of TGFβRI were further detected in rat cartilage and human umbilical cord from IUGR individuals.

Results

Glycosaminoglycan content and the expression levels of chondrogenic genes were decreased in the WJ-MSCs from IUGR, and the expression levels of chondrogenic genes were further reduced after IL-1β treatment, while the expression levels of catabolic factors were increased. Then, serum cortisol level from IUGR individuals was found increased, and similar changes were observed in normal WJ-MSCs treated with excessive cortisol. Moreover, the decreased histone 3 lysine 9 acetylation (H3K9ac) level of TGFβRI and its expression were observed in IUGR-derived WJ-MSCs and normal WJ-MSCs treated with excessive cortisol, which could be abolished by RU486 and LMK235. At last, the decreased H3K9ac level of TGFβRI and its expression were further confirmed in the cartilage of IUGR rat offspring and human umbilical cords from IUGR newborn.

Conclusions

WJ-MSCs from IUGR individuals displayed a poor capacity of chondrogenic differentiation and an increased susceptibility to osteoarthritis-like phenotype, which was attributed to the decreased H3K9ac level of TGFβRI and its expression induced by high cortisol through GR/HDAC4. The H3K9ac of TGFβRI in human umbilical cord could be a potential early-warning biomarker for predicting neonatal cartilage dysplasia and osteoarthritis susceptibility.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02234-8.

Vitamin E pretreated Wharton's jelly-derived mesenchymal stem cells attenuate CCl4-induced hepatocyte injury in vitro and liver fibrosis in vivo

Oxidative microenvironment in fibrotic liver alleviates the efficacious outcome of mesenchymal stem cells (MSCs)-based cell therapy. Recent evidence suggests that pharmacological pretreatment is a rational approach to harness the MSCs with higher therapeutic potential. Here, we investigated whether Vitamin E pretreatment can boost the antifibrotic effects of Wharton's jelly-derived MSCs (WJMSCs). We used rat liver-derived hepatocytes injured by CCl₄ treatment in co-culture system with Vitamin E pretreated-WJMSCs (Vit E-WJMSCs) to evaluate the hepatoprotective effect of Vit E-WJMSCs. After 24 h of co-culturing, we found that Vit E-WJMSCs rescued injured hepatocytes as hepatocyte injury-associated medium (AST, ALT, and ALP) and mRNA (Cyp2e1, Hif1-α, and Il-1β) markers reduced to normal levels. Subsequently, CCl₄-induced liver fibrosis rat models were employed to examine the antifibrotic potential of Vit E-WJMSCs. After 1 month of cell transplantation, it was revealed that Vit E-WJMSCs transplantation ceased fibrotic progression, as evident by improved hepatic architecture and functions, more significantly in comparison to naïve WJMSCs. In addition, Vit E-WJMSCs transplantation decreased the expressions of fibrosis-associated gene (Tgf-β1, α-Sma, and Col1α1) markers in the liver parenchyma. Intriguingly, the results of tracing experiments discovered that more WJMSCs engrafted in the Vit E-WJMSCs treated rat livers compared to naïve WJMSCs treated livers. These findings implicate that pretreatment of WJMSCs with Vitamin E improves their tolerance to hostile niche of fibrotic liver; thereby further enhancing their efficacy for hepatic fibrosis.

Mesenchymal Stem Cells Derived from Wharton's Jelly Can Differentiate into Schwann Cell-Like Cells and Promote Peripheral Nerve Regeneration in Acellular Nerve Grafts

BACKGROUND

Schwann cells (SCs) secrete neurotrophic factors and provide structural support and guidance during axonal regeneration. However, nearby nerves may be damaged to obtain primary SCs, and there is a lack of nervous tissue donors. We investigated the potential of Wharton's Jelly-derived mesenchymal stem cells (WJ-MSCs) in differentiating into Schwann cell-like cells (WJ-SCLCs) as an alternative to SCs. We also examined whether implantation of WJ-SCLCs-laden acellular nerve grafts (ANGs) are effective in inducing functional recovery and nerve regeneration in an animal model of peripheral nerve injury.

METHODS

The differentiation of WJ-MSCs into WJ-SCLCs was determined by analyzing SC-specific markers. The secretion of neurotrophic factors was assessed by the Neuro Discovery antibody array. Neurite outgrowth and myelination of axons were found in a co-culture system involving motor neuron cell lines. The effects of ANGs on repairing sciatic nerves were evaluated using video gait angle test, isometric tetanic force analysis, and toluidine blue staining.

RESULTS

Compared with undifferentiated WJ-MSCs, WJ-SCLCs showed higher expression levels of SC-specific markers such as S100β, GFAP, KROX20, and NGFR. WJ-SCLCs also showed higher secreted amounts of brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, and granulocyte-colony stimulating factor than did WJ-MSCs. WJ-SCLCs effectively promoted the outgrowth and myelination of neurites in motor neuron cells, and WJ-SCLCs laden ANGs significantly facilitated peripheral nerve regeneration in an animal model of sciatic nerve injury.

CONCLUSION

WJ-MSCs were readily differentiated into WJ-SCLCs, which effectively promoted the regeneration of peripheral nerves. Transplantation of WJ-SCLCs with ANGs might be useful for assisting peripheral nerve regeneration.

Circ6401, a novel circular RNA, is implicated in repair of the damaged endometrium by Wharton's jelly-derived mesenchymal stem cells through regulation of the miR-29b-1-5p/RAP1B axis

Background

Accumulating evidence indicates that mesenchymal stem cells (MSCs) exert tissue repair effects and therapeutic angiogenesis through their noncoding RNAs (ncRNAs). Our previous studies showed that MSCs derived from Wharton’s jelly (WJ-MSCs) can ameliorate damaged human endometrium by promoting angiogenesis. There is limited information on the functions and mechanism of ncRNAs in MSC-induced endometrial repair, and additional studies are needed for more insights.

Methods

Here, WJ-MSCs were cocultured with or without endometrial stromal cells (ESCs) damaged by mifepristone (cocultured group versus non-cocultured group). TUNEL staining assays, EdU proliferation assays, flow cytometry apoptosis assays, and western blot assays were performed to observe the reparative effect of WJ-MSCs on damaged ESCs. Subsequently, circular RNA (circRNA) and microRNA microarrays were performed between the two groups. A subset of top upregulated circRNAs was validated by qRT-PCR. The functions of circ6401 (hsa_circ_0006401) in WJ-MSCs were investigated using lentivirus-mediated circRNA overexpression assays. The subcellular localization of circ6401 and miR-29b-1-5p in WJ-MSCs was identified by double RNA fluorescence in situ hybridization. Dual-luciferase reporter assays and western blot assays were performed to elucidate the regulatory mechanisms among circ6401, miR-29b-1-5p, and RAP1B.

Results

WJ-MSCs significantly improved ESC proliferation and upregulated the expression of vascular angiogenesis markers. Circ6401 was upregulated in WJ-MSCs cocultured with damaged ESCs, while miR-29b-1-5p was significantly downregulated. Furthermore, circ6401 was found to bind to miR-29b-1-5p and prevent it from decreasing the level of RAP1B, a crucial protein involved in the VEGF signaling pathway, which promoted angiogenesis and stimulated the proliferation of ESCs.

Conclusions

Our results showed the abundance and regulation profiles of ncRNAs of WJ-MSCs during repair of damaged ESCs and, for the first time, clarified the underlying mechanism by which circ6401 promotes endometrial repair by WJ-MSCs; thus, demonstrating that circ6401 may serve as a potential therapeutic target.

Pressure Stimuli Improve the Proliferation of Wharton's Jelly-Derived Mesenchymal Stem Cells under Hypoxic Culture Conditions

Mesenchymal stem cells (MSCs) are safe, and they have good therapeutic efficacy through their paracrine action. However, long-term culture to produce sufficient MSCs for clinical use can result in side-effects, such as an inevitable senescence and the reduction of the therapeutic efficacy of the MSCs. In order to overcome this, the primary culture conditions of the MSCs can be modified to simulate the stem cells’ niche environment, resulting in accelerated proliferation, the achievement of the target production yield at earlier passages, and the improvement of the therapeutic efficacy. We exposed Wharton’s jelly-derived MSCs (WJ-MSCs) to pressure stimuli during the primary culture step. In order to evaluate the proliferation, stemness, and therapeutic efficacy of WJ-MSCs, image, genetic, and Western blot analyses were carried out. Compared with standard incubation culture conditions, the cell proliferation was significantly improved when the WJ-MSCs were exposed to pressure stimuli. However, the therapeutic efficacy (the promotion of cell proliferation and anti-apoptotic effects) and the stemness of the WJ-MSCs was maintained, regardless of the culture conditions. Exposure to pressure stimuli is a simple and efficient way to improve WJ-MSC proliferation without causing changes in stemness and therapeutic efficacy. In this way, clinical-grade WJ-MSCs can be produced rapidly and used for therapeutic applications.

Comparative Proteomic Analysis Identifies EphA2 as a Specific Cell Surface Marker for Wharton's Jelly-Derived Mesenchymal Stem Cells

Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) are a valuable tool in stem cell research due to their high proliferation rate, multi-lineage differentiation potential, and immunotolerance properties. However, fibroblast impurity during WJ-MSCs isolation is unavoidable because of morphological similarities and shared surface markers. Here, a proteomic approach was employed to identify specific proteins differentially expressed by WJ-MSCs in comparison to those by neonatal foreskin and adult skin fibroblasts (NFFs and ASFs, respectively). Mass spectrometry analysis identified 454 proteins with a transmembrane domain. These proteins were then compared across the different cell-lines and categorized based on their cellular localizations, biological processes, and molecular functions. The expression patterns of a selected set of proteins were further confirmed by quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blotting, and immunofluorescence assays. As anticipated, most of the studied proteins had common expression patterns. However, EphA2, SLC25A4, and SOD2 were predominantly expressed by WJ-MSCs, while CDH2 and Talin2 were specific to NFFs and ASFs, respectively. Here, EphA2 was established as a potential surface-specific marker to distinguish WJ-MSCs from fibroblasts and for prospective use to prepare pure primary cultures of WJ-MSCs. Additionally, CDH2 could be used for a negative-selection isolation/depletion method to remove neonatal fibroblasts contaminating preparations of WJ-MSCs.

Changes in Stemness Properties, Differentiation Potential, Oxidative Stress, Senescence and Mitochondrial Function in Wharton's Jelly Stem Cells of Umbilical Cords of Mothers with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) has been associated with an increased risk of maternal and neonatal morbidity. The Wharton's jelly (WJ) of the umbilical cord (UC) is a useful indicator of the deleterious effects of hyperglycemia on fetal tissues as it represents the fetus embryologically, physiologically and genetically. We studied WJ mesenchymal stem cells (hWJSCs) from UC from mothers without GDM (Normal; n = 3); insulin-controlled GDM mothers (GDMi; n = 3) and diet-controlled GDM mothers (GDMd; n = 3)]. Cell proliferation, stemness markers, telomerase, osteogenic and chondrogenic differentiation, antioxidant enzymes and gene expression for mitochondrial function (ND2, TFAM, PGC1α, and NDUFB9) were significantly lower in GDMi-hWJSCs and GDMd-hWJSCs compared to normal hWJSCs (P < 0.05). On the other hand, cell cycle inhibitors (p16, p21, p27) and p53 were remarkably up-regulated in GDMi-hWJSCs and GDMd-hWJSCs compared to normal hWJSCs. The results from this study confirmed that maternal hyperglycemia even though managed with insulin or diet, induced changes in the properties of the WJ and its cells. These changes may also be observed in fetal tissues and if true, prevention of the onset of gestational diabetes should be a priority over management. Generation of tissues that simulate those of the fetus such as pancreatic and cardiovascular cells from GDM-hWJSCs by direct differentiation or via induced pluripotent stem cell reprogramming provide possible platforms to evaluate the effects of glucose on specific fetal organ.

Shockwave Therapy Combined with Autologous Adipose-Derived Mesenchymal Stem Cells Is Better than with Human Umbilical Cord Wharton's Jelly-Derived Mesenchymal Stem Cells on Knee Osteoarthritis

Extracorporeal shockwave therapy (ESWT) and mesenchymal stem cells (MSCs) have been reported to have chondroprotective effects in knee osteoarthritis (OA). Here, we examined whether autologous adipose-derived mesenchymal stem cells (ADMSCs) and human umbilical cord Wharton’s jelly-derived mesenchymal stem cells (WJMSCs) increased the efficacy of ESWT in knee OA, and compared the efficacy of the two. The treatment groups exhibited significant improvement of knee OA according to pathological analysis, micro-computed tomography (CT), and immunohistochemistry (IHC) staining. The ADMSCs and ESWT+ADMSCs groups exhibited increased trabecular thickness and bone volume as compared with the ESWT, WJMSCs, and ESWT+WJMSCs groups individually. According to the results of IHC staining, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) activity and caspase-3 were significantly reduced in the ADMSCs and ESWT+ADMSCs groups as compared with the WJMSCs and ESWT+WJMSC groups. In mechanistic factor analysis, the synergistic effect of ESWT+ADMSCs was observed as being greater than the efficacies of other treatments in terms of expressions of transforming growth factor (TGF)-β, runt-related transcription factor (RUNX)-2 and sex determining region Y-box (SOX)-9. The type II collagen was expressed at a higher level in the WJMSCs group than in the others. Furthermore, ESWT+ADMSCs reduced the expression of platelet-derived growth factor (PDGF)-BB and increased the expression of bone morphogenetic protein (BMP)-4. Therefore, we demonstrated that ESWT+ADMSCs had a synergistic effect greater than that of ESWT+WJMSCs for the treatment of early knee OA.

Wharton's jelly-derived mesenchymal stem cells attenuate sepsis-induced organ injury partially via cholinergic anti-inflammatory pathway activation

Sepsis induces organ dysfunction due to overexpression of the inflammatory host response, resulting in cardiopulmonary and autonomic dysfunction, thus increasing the associated morbidity and mortality. Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) express genes and secrete factors with anti-inflammatory properties, neurological and immunological protection, as well as improve survival in experimental sepsis. The cholinergic anti-inflammatory pathway (CAP) is mediated by α7-nicotinic acetylcholine receptors (α7nAChRs), which play an important role in the control of systemic inflammation. We hypothesized that WJ-MSCs attenuate sepsis-induced organ injury in the presence of an activated CAP pathway. To confirm our hypothesis, we evaluated the effects of WJ-MSCs as a treatment for cardiopulmonary injury and on neuroimmunomodulation. Male Wistar rats were randomly divided into four groups: control (sham-operated); cecal ligation and puncture (CLP) alone; CLP+WJ-MSCs (1 × 10⁶ cells, at 6 h post-CLP); and CLP+methyllycaconitine (MLA)+WJ-MSCs (5 mg/kg body wt, at 5.5 h post-CLP, and 1 × 10⁶ cells, at 6 h post-CLP, respectively). All experiments, including the assessment of echocardiographic parameters and heart rate variability, were performed 24 h after CLP. WJ-MSC treatment attenuated diastolic dysfunction and restored baroreflex sensitivity. WJ-MSCs also increased cardiac sympathetic and cardiovagal activity. WJ-MSCs reduced leukocyte infiltration and proinflammatory cytokines, effects that were abolished by administration of a selective α7nAChR antagonist (MLA). In addition, WJ-MSC treatment also diminished apoptosis in the lungs and spleen. In cardiac and splenic tissue, WJ-MSCs downregulated α7nAChR expression, as well as reduced the phospho-STAT3-to-total STAT3 ratio in the spleen. WJ-MSCs appear to protect against sepsis-induced organ injury by reducing systemic inflammation, at least in part, via a mechanism that is dependent on an activated CAP.

Differentiation of human mesenchymal stem cells (MSC) to dopaminergic neurons: A comparison between Wharton's Jelly and olfactory mucosa as sources of MSCs

The generation of dopaminergic neurons from stem cells is a potential therapeutic approach to treat neurodegenerative disorders, such as Parkinson's disease. The current study aims to investigate the potential of two different types of mesenchymal stem cells derived from human Wharton's jelly and nasal cavity for differentiation into dopaminergic neurons. The differentiation capacities of both cell types were evaluated using real-time PCR, immunocytochemistry, flow cytometry and HPLC. Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are noted for their capability to differentiate into mesodermal and non-mesodermal cells, including neurons. However, it was demonstrated that having the same neuroectodermal origin as the nervous system, the olfactory ectomesenchymal stem cells (OE-MSCs) expressed the neural marker MAP2 as well as dopaminergic markers such as tyrosine hydroxylase (TH), dopamine transporter (DAT) and PITX3 to a greater extent than the WJ-MSCs both at the level of mRNA and protein. Furthermore, quantitative flow cytometric evaluation of these markers at 12 days post-induction supported the above-mentioned results. Finally, the assessment of the functionality of differentiated cells and their ability to synthesize dopamine measured by HPLC revealed that the OE-MSC-derived dopaminergic cells released almost the same amount of dopamine as that secreted by WJ-MSC-derived cells. Thus it showed the difference in their functionality to be negligible. Overall, it may be concluded that higher proliferation and differentiation capacity of OE-MSCs, along with their easier harvestability and autologous transplantability compared with WJ-MSCs, makes them a better cell source for stem cell therapy of neurodegenerative disorders which are caused by degeneration of dopaminergic neurons.

Circular RNAs are abundantly expressed and upregulated during repair of the damaged endometrium by Wharton's jelly-derived mesenchymal stem cells

BACKGROUND

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) exhibit strong and powerful potential in repairing different diseases. The expression profile of circular RNA (circRNA) provides valuable insight for regulation of the repair process and exploration of reparative effect mechanisms.

METHODS

Human endometrial stromal cells (ESCs) were cultured with mifepristone to obtain damaged ESCs, which were then cocultured with or without WJ-MSCs (cocultured group versus non-cocultured group) to observe the reparative effect upon damaged ESCs by WJ-MSCs. CircRNA microarray was performed between the two groups. Based on the transcriptomics data, the differential gene expression profiles of the two groups were analyzed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and network analysis methods. Screening of a circRNA database was performed, and the results were confirmed by quantitative polymerase chain reaction (qPCR).

RESULTS

WJ-MSCs exerted a reparative effect upon damaged ESCs in the cocultured group such as improved cell morphology, higher proliferative ability, and lower apoptosis rate. CircRNA array showed that 7757 circRNAs were differentially expressed in ESCs from the cocultured group. Mitotic cell cycle, cell cycle process, and nuclear division ranked top in the GO upregulated list of the two groups, while DNA replication and cell cycle ranked top in the KEGG pathway analysis upregulated list of the two groups. The nine most aberrantly expressed circRNAs were selected for further verification in the same cohort of samples by microarray analysis. Seven of the nine most aberrantly circRNAs were confirmed to be significantly upregulated in the cocultured group. And four of the seven circRNAs (hsa_circ_0015825, hsa-circRNA4049-38, hsa-circRNA5028-15, and hsa_circ_0111659) expression both in ESCs and WJ-MSCs tended to decrease with time by qPCR. The levels of the remaining three circRNAs (hsa-circRNA8881-21, hsa_circ_0020492 and hsa_circ_ 0026141) did not change significantly over time in either ESCs or WJ-MSCs. Moreover, we focused on hsa_circRNA_0111659 and predicted its miRNAs and targeted mRNA. The association of circRNA-miRNA-mRNA is likely to be involved in regulating the repair of endometrial damage.

CONCLUSIONS

Our results presented the abundant and upregulated circRNAs profile during repair of the damaged endometrium by WJ-MSCs and provided a novel perspective for circRNAs in the regulation of WJ-MSCs for endometrial repair.

Extracellular matrix deposited by Wharton's jelly mesenchymal stem cells enhances cell expansion and tissue specific lineage potential

This article aims to explore whether Wharton's jelly (WJ) derived mesenchymal stem cells (MSCs) (WJ-MSCs) decellularized extracellular matrix (dECM) can rejuvenate MSCs during in vitro expansion. Passage 10 synovium-derived mesenchymal stem cells (SDSCs) and WJ-MSCs were expanded on plastic flasks (PL) or dECMs derived from SDSCs and WJ-MSCs. Flow cytometry was applied to evaluate surface phenotypes and proliferation capacity. Early (7 days) and late (21 days) chondrogenic potentials were assessed using histology, immunohistochemistry, and real-time polymerase chain reaction (PCR). Western blot analysis was applied to evaluate the potential involvement of MAPK and Wnts signals during the proliferation and chondrogenic processes. Cells were further evaluated for their osteogenic potential using alkaline phosphatase staining and RT-PCR and adipogenic potential using oil red O staining and RT-PCR. Compared to PL expanded cells, dECMs yielded expanded cells with better proliferation capacity as well as decreased percentage of HLA-DR positive SDSCs. Meanwhile, a decrease in CD105 median fluorescence intensity of WJ-MSCs groups were observed compared to the corresponding SDSCs groups. Moreover, both SDSCs and WJ-MSCs acquired better chondrogenic potential after dECM treatment, as evidenced by increased pellet sizes and increased expression of chondrogenic marker genes. WJ-MSCs dECM was inferior to SDSCs dECM in enhancing early stage chondrogenic differentiation, which was compensated during late stage chondrogenesis, despite causing an increased type X collagen accumulation. p-JNK and p-38 were implicated in the expansion and late chondrogenic differentiation stages, respectively. However, dECM preconditioning did not enhance either osteogenic or adipogenic potential of SDSCs and WJ-MSCs. WJ-MSCs dECM is superior to SDSCs dECM on enhancing proliferation, lowering immunogenicity and promoting late stage chondrogenesis.

Tracing GFP-labeled WJMSCs in vivo using a chronic salpingitis model: an animal experiment

Background

The present study was conducted to evaluate the distribution of Wharton’s jelly-derived mesenchymal stem cells (WJMSCs) and their repairing function on the oviduct.

Methods

WJMSCs were transfected with the LV3-GFP-PURO lentivirus. Female New Zealand rabbits (n = 24) were divided randomly into control A and B groups and experimental C and D groups to establish inflammation models. Sterile saline solution or WJMSCs were injected into rabbits via ear veins and/or genital tract perfusion once weekly for 3 weeks. All rabbits were humanely sacrificed 1 week after the last perfusion to collect the oviduct, uterus, liver, and bladder for examination. Green fluorescent protein (GFP) and cytokeratin 7 (CK7) were imaged using a Leica Qwin Plus V3 fluorescence confocal microscope and analyzed as mean optical densities in an Image-Pro Plus analysis system.

Results

We found that lentivirus expressing the GFP gene produced an efficient transfection. The mean optical density values of GFP and CK7 in the oviducts were higher in the experimental D group than those in the control A and experimental C groups. No GFP fluorescence deposits occurred in the bladder of the control A group or experimental C group. Colocalization of CK7 and WJMSCs was observed in the oviducts in all groups.

Conclusions

WJMSCs exhibited homing characteristics and migrated to the injured oviduct to promote epithelial cell growth. Additionally, local treatment resulted in higher efficiency.

Differentiation of human umbilical cord Wharton's jelly-derived mesenchymal stem cells into endometrial cells

BACKGROUND

Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are a novel and promising strategy for tissue engineering because of their ability to differentiate into many cell types. We characterized the differentiation of WJ-MSCs into endometrial epithelial cell (EEC)-like and endometrial stromal cell (ESC)-like cells and assessed the effect of 17β-estradiol and 8-Br-cAMP on the differentiation system.

METHODS

WJ-MSCs were treated in two ways to differentiate into EEC-like and ESC-like cells respectively: cocultured with ESCs in control/differentiation medium (17β-estradiol, growth factors); and cultured in control/differentiation medium (8-Br-cAMP alone or 8-Br-cAMP plus 17β-estrogen and growth factors). Three signaling pathway inhibitors (SB203580, PD98059, H89) were used to investigate the mechanism of WJ-MSC differentiation into ESC-like cells. Immunofluorescence, western blot and flow cytometry analyses were used to analyze expression of epithelial markers and stromal cell markers. Enzyme-linked immunosorbent assays were used to test the production of secretory proteins associated with the differentiation of ESC-like cells.

RESULTS

17β-estradiol at 1 μM downregulated vimentin and CD13 and upregulated cytokeratin and CD9 proteins, promoting the differentiation of WJ-MSCs into EEC-like cells in the coculture system. 8-Br-cAMP at 0.5 mM upregulated vimentin and CD13 and downregulated CK and CD9, promoting the differentiation of WJ-MSCs into ESC-like cells. Prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) were upregulated and the protein kinase A (PKA) signaling pathway was activated, whereas extracellular signal-regulated (ERK)1/2 and p38 mitogen-activated protein kinase (MAPK) were not affected.

CONCLUSIONS

17β-estradiol at 1 μM is a good inducer for facilitating the differentiation of WJ-MSCs into EEC-like cells. 8-Br-cAMP plus estrogen and growth factors can induce the differentiation of WJ-MSCs into ESC-like cells. During the differentiation of WJ-MSCs into ESC-like cells, PRL and IGFBP1 were upregulated by the treatment and the PKA signaling pathway was activated, whereas ERK1/2 and p38 MAPK were not affected. These findings suggest a promising approach to the treatment of endometrial damage and other endometrial diseases and suggest new applications for WJ-MSCs in clinical practice.

Treatment evaluation of Wharton's jelly-derived mesenchymal stem cells using a chronic salpingitis model: an animal experiment

Background

The present study was conducted to evaluate new methods to repair the reproductive function of the oviduct, thereby allowing gametes to combine and grow in vivo under natural circumstances.

Methods

Sixty pathogen-free female New Zealand rabbits were divided into three groups: a wild-type group, an untreated control group, and a treatment group. Disposable sterile newborn sputum suction tubes were inserted into the urogenital tract to instill an Escherichia coli suspension into the uterine cavity to establish the chronic salpingitis model. Wharton’s jelly-derived mesenchymal stem cells (WJMSCs) or normal saline were used to treat this infection via different methods. The therapeutic effect was assessed by evaluating morphology, inflammatory factors, proteinology, and pregnancy outcomes.

Results

Oviducts of New Zealand rabbits in the untreated control group showed structural failure and abnormal supermicrostructure of epithelial cells. WJMSCs could partially repair the structure and supermicrostructure of the tubal epithelium. The concentration of tumor necrosis factor (TNF)-α in the untreated control group was significantly higher than that in the wild-type group (P = 0.015). The concentration of TNF-α in the local treatment group was significantly lower than that in the untreated control group (P = 0.011). The expression of oviductal glycoprotein (OVGP) and OVGP mRNA in the wild-type group was significantly higher than those in the untreated control group (P = 0.024 and P = 0.013, respectively). The litter size of the treatment group was 2 ± 2.39 kits, which was higher than that of the untreated control group (P = 0.035).

Conclusion

Chronic inflammation can destroy the structure of the oviduct and the supermicrostructure of epithelial cells as well as leading to infertility. WJMSC transplantation therapy in rabbits with chronic salpingitis partially restored fertility. WJMSCs also repaired the structure of the tubal epithelium subjected to chronic inflammation, decreased the level of inflammatory factors, and partially restored the secretion level of OVGP.

Defined three-dimensional culture conditions mediate efficient induction of definitive endoderm lineage from human umbilical cord Wharton's jelly mesenchymal stem cells

Background

Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) are gaining increasing interest as an alternative source of stem cells for regenerative medicine applications. Definitive endoderm (DE) specification is a prerequisite for the development of vital organs such as liver and pancreas. Hence, efficient induction of the DE lineage from stem cells is crucial for subsequent generation of clinically relevant cell types. Here we present a defined 3D differentiation protocol of WJ-MSCs into DE cells.

Methods

WJ-MSCs were cultured in suspension to generate spheroids, about 1500 cells each, for 7 days. The serum-free differentiation media contained specific growth factors, cytokines, and small molecules that specifically regulate signaling pathways including sonic hedgehog, bone morphogenetic protein, Activin/Wnt, and Notch.

Results

We obtained more than 85 % DE cells as shown with FACS analysis using antibodies directed against the DE marker CXCR4. In addition, biochemical and molecular analysis of bona-fide DE markers revealed a time-course induction of Sox17, CXCR4, and FoxA2. Focused PCR-based array also indicated a specific induction into the DE lineage.

Conclusions

In this study, we report an efficient serum-free protocol to differentiate WJ-MSCs into DE cells utilizing 3D spheroid formation. Our approach might aid in the development of new protocols to obtain DE-derivative lineages including liver-like and pancreatic insulin-producing cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0426-9) contains supplementary material, which is available to authorized users.

Treatment With Human Wharton's Jelly-Derived Mesenchymal Stem Cells Attenuates Sepsis-Induced Kidney Injury, Liver Injury, and Endothelial Dysfunction

: The pathophysiology of sepsis involves complex cytokine and inflammatory mediator networks. Downregulation of endothelial nitric oxide synthase contributes to sepsis-induced endothelial dysfunction. Human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) are known to reduce expression of proinflammatory cytokines and markers of apoptosis. We hypothesized that treatment with WJ-MSCs would protect renal, hepatic, and endothelial function in a cecal ligation and puncture (CLP) model of sepsis in rats. Rats were randomly divided into three groups: sham-operated rats; rats submitted to CLP and left untreated; and rats submitted to CLP and intraperitoneally injected, 6 hours later, with 1 × 10(6) WJ-MSCs. The glomerular filtration rate (GFR) was measured at 6 and 24 hours after CLP or sham surgery. All other studies were conducted at 24 hours after CLP or sham surgery. By 6 hours, GFR had decreased in the CLP rats. At 24 hours, Klotho renal expression significantly decreased. Treatment with WJ-MSCs improved the GFR; improved tubular function; decreased the CD68-positive cell count; decreased the fractional interstitial area; decreased expression of nuclear factor κB and of cytokines; increased expression of eNOS, vascular endothelial growth factor, and Klotho; attenuated renal apoptosis; ameliorated hepatic function; increased glycogen deposition in the liver; and improved survival. Sepsis-induced acute kidney injury is a state of Klotho deficiency, which WJ-MSCs can attenuate. Klotho protein expression was higher in WJ-MSCs than in human adipose-derived MSCs. Because WJ-MSCs preserve renal and hepatic function, they might play a protective role in sepsis.

SIGNIFICANCE

Sepsis is the leading cause of death in intensive care units. Although many different treatments for sepsis have been tested, sepsis-related mortality rates remain high. It was hypothesized in this study that treatment with human Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) would protect renal, hepatic, and endothelial function in a model of sepsis in rats. Treatment with WJ-MSCs improved the glomerular filtration rate, improved tubular function, decreased expression of nuclear factor κB and of cytokines, increased expression of eNOS and of Klotho, attenuated renal apoptosis, and improved survival. Sepsis-induced acute kidney injury is a state of Klotho deficiency, which WJ-MSCs can attenuate.