HucMSCs Delay Muscle Atrophy After Peripheral Nerve Injury Through Exosomes by Repressing Muscle-Specific Ubiquitin Ligases.

Cell therapy based on mesenchymal stem cells (MSCs) alleviate muscle atrophy caused by diabetes and aging; however, the impact of human umbilical cord mesenchymal stem cells on muscle atrophy following nerve injury and the underlying mechanisms remain unclear. In this study, we evaluated the therapeutic efficacy of human umbilical cord MSCs (hucMSCs) and hucMSC-derived exosomes (hucMSC-EXOs) for muscle atrophy following nerve injury and identified the underlying molecular mechanisms. Sciatic nerve crush injury in rats and the induction of myotubes in L6 cells were used to determine the ameliorating effect of hucMSCs and hucMSC-EXOs on muscle atrophy. Q-PCR and Western blot analyses were used to measure the expression of muscle-specific ubiquitin ligases Fbxo32 (Atrogin1, MAFbx) and Trim63 (MuRF-1). Dual-luciferase reporter gene experiments were conducted to validate the direct binding of miRNAs to their target genes. Local injection of hucMSCs and hucMSC-EXOs mitigated atrophy in the rat gastrocnemius muscle following sciatic nerve crush injury. In vitro, hucMSC-EXOs alleviated atrophy in L6 myotubes. Mechanistic analysis indicated the upregulation of miR-23b-3p levels in L6 myotubes following hucMSC-EXOs treatment. MiR-23b-3p significantly inhibited the expression of its target genes, Fbxo32 and Trim63, and suppressed myotube atrophy. Notably, an miR-23b-3p inhibitor reversed the inhibitory effect of miR-23b-3p on myotube atrophy in vitro. These results suggest that hucMSCs and their exosomes alleviate muscle atrophy following nerve injury. MiR-23b-3p in exosomes secreted by hucMSCs contributes to this mechanism by inhibiting the muscle-specific ubiquitination ligases Fbxo32 and Trim63.

Human umbilical cord mesenchymal stem cell-derived exosomes ameliorate renal fibrosis in diabetic nephropathy by targeting Hedgehog/SMO signaling.

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease globally. Currently, there are no effective drugs for the treatment of DN. Although several studies have reported the therapeutic potential of mesenchymal stem cells, the underlying mechanisms remain largely unknown. Here, we report that both human umbilical cord MSCs (UC-MSCs) and UC-MSC-derived exosomes (UC-MSC-exo) attenuate kidney damage, and inhibit epithelial-mesenchymal transition (EMT) and renal fibrosis in streptozotocin-induced DN rats. Strikingly, the Hedgehog receptor, smoothened (SMO), was significantly upregulated in the kidney tissues of DN patients and rats, and positively correlated with EMT and renal fibrosis. UC-MSC and UC-MSC-exo treatment resulted in decrease of SMO expression. In vitro co-culture experiments revealed that UC-MSC-exo reduced EMT of tubular epithelial cells through inhibiting Hedgehog/SMO pathway. Collectively, UC-MSCs inhibit EMT and renal fibrosis by delivering exosomes and targeting Hedgehog/SMO signaling, suggesting that UC-MSCs and their exosomes are novel anti-fibrotic therapeutics for treating DN.

Exosomes derived from human umbilical cord mesenchymal stem cells pretreated by monosialoteterahexosyl ganglioside alleviate intracerebral hemorrhage by down-regulating autophagy.

PURPOSE: Intracerebral hemorrhage (ICH) results in substantial morbidity, mortality, and disability. Depleting neural cells in advanced stages of ICH poses a significant challenge to recovery. The objective of our research is to investigate the potential advantages and underlying mechanism of exosomes obtained from human umbilical cord mesenchymal stem cells (hUMSCs) pretreated with monosialoteterahexosyl ganglioside (GM1) in the prevention of secondary brain injury (SBI) resulting from ICH. PATIENTS AND METHODS: In vitro, hUMSCs were cultured and induced to differentiate into neuron-like cells after they were pretreated with 150 µg/mL GM1. The exosomes extracted from the culture medium following a 6-h pretreatment with 150 µg/mL GM1 were used as the treatment group. Striatal infusion of collagenase and hemoglobin (Hemin) was used to establish in vivo and in vitro models of ICH. RESULTS: After being exposed to 150 µg/mL GM1 for 6 h, specific cells displayed typical neuron-like cell morphology and expressed neuron-specific enolase (NSE). The rate of differentiation into neuron-like cells was up to (15.9 ± 5.8) %, and the synthesis of N-Acetylgalactosaminyltransferase (GalNAcT), which is upstream of GM1, was detected by Western blot. This study presented an increase in the synthesis of GalNAcT. Compared with the ICH group, apoptosis in the treatment group was remarkably reduced, as detected by TUNEL, and mitochondrial membrane potential was restored by JC-1. Additionally, Western blot revealed the restoration of up-regulated autophagy markers Beclin-1 and LC3 and the down-regulation of autophagy marker p62 after ICH. CONCLUSION: These findings suggest that GM1 is an effective agent to induce the differentiation of hUMSCs into neuron-like cells. GM1 can potentially increase GalNAcT production through "positive feedback", which generates more GM1 and promotes the differentiation of hUMSCs. After pretreatment with GM1, exosomes derived from hUMSCs (hUMSCs-Exos) demonstrate a neuroprotective effect by inhibiting autophagy in the ICH model. This study reveals the potential mechanism by which GM1 induces differentiation of hUMSCs into neuron-like cells and confirms the therapeutic effect of hUMSCs-Exos pretreated by GM1 (GM1-Exos) on an ICH model, potentially offering a new direction for stem cell therapy in ICH.

Umbilical cord MSC-derived exosomes improve alveolar macrophage function and reduce LPS-induced acute lung injury.

Acute lung injury (ALI) is a severe condition that can progress to acute respiratory distress syndrome (ARDS), with a high mortality rate. Currently, no specific and compelling drug treatment plan exists. Mesenchymal stem cells (MSCs) have shown promising results in preclinical and clinical studies as a potential treatment for ALI and other lung-related conditions due to their immunomodulatory properties and ability to regenerate various cell types. The present study focuses on analyzing the role of umbilical cord MSC (UC-MSC))-derived exosomes in reducing lipopolysaccharide-induced ALI and investigating the mechanism involved. The study demonstrates that UC-MSC-derived exosomes effectively improved the metabolic function of alveolar macrophages and promoted their shift to an anti-inflammatory phenotype, leading to a reduction in ALI. The findings also suggest that creating three-dimensional microspheres from the MSCs first can enhance the effectiveness of the exosomes. Further research is needed to fully understand the mechanism of action and optimize the therapeutic potential of MSCs and their secretome in ALI and other lung-related conditions.

HGF secreted by hUC-MSCs mitigates neuronal apoptosis to repair the injured spinal cord via phosphorylation of Akt/FoxO3a pathway.

Spinal cord injury (SCI) can cause severe and permanent neurological damage, and neuronal apoptosis could inhibit functional recovery of damaged spinal cord greatly. Human umbilical cord mesenchymal stem cells (hUC-MSCs) have great potential to repair SCI because of a series of advantages, including inhibition of neuronal apoptosis and multiple differentiation. The former may play an important role. However, the detailed regulatory mechanism associated with the inhibition of neuronal apoptosis after hUC-MSCs administration has not been elucidated. In this study, proteomics analysis of precious human cerebrospinal fluid (CSF) samples collected from SCI subjects receiving hUC-MSCs delivery indicated that hepatocyte growth factor (HGF) is largely involved in SCI repair. Furthermore, overexpression of HGF derived from hUC-MSCs could decrease reactive oxygen species to prevent neuron apoptosis to the maximum, and thus lead to significant recovery of spinal cord dysfunction. Moreover, HGF could promote phosphorylation of Akt/FoxO3a pathway to decrease reactive oxygen species to reduce neuron apoptosis. For the first time, our research revealed that HGF secreted by hUC-MSCs inhibits neuron apoptosis by phosphorylation of Akt/FoxO3a to repair SCI. This study provides important clues associated with drug selection for the effective treatment of SCI in humans.

hucMSCs Treatment Ameliorated Pulmonary Fibrosis via Downregulating the circFOXP1-HuR-EZH2/STAT1/FOXK1 Autophagic Axis.

This study was performed to determine the effect of human umbilical cord mesenchymal stem cells (hucMSCs) treatment on pulmonary fibrosis and investigate the circFOXP1-mediated autophagic mechanism of hucMSCs treatment. Pulmonary fibrosis models were established by spraying bleomycin in mice and TGF-ß1 treatment of MRC-5 cells. Results showed that hucMSCs were retained in lung and hucMSCs treatment alleviated pulmonary fibrosis. Morphological staining indicated that hucMSCs-treated mice had thinner alveolar walls, effectively improved alveolar structure, significantly reduced alveolar inflammation, and decreased collagen deposition than control mice. Fibrotic proteins, including vimentin, α-SMA, collagens I and III, and the differentiation-related protein S100 calcium-binding protein A4 was reduced considerably in the hucMSCs-treated group. The mechanistic study revealed that the inhibition of hucMSCs treatment on pulmonary fibrogenesis depended on downregulating circFOXP1, in which hucMSCs treatment promoted circFOXP1-mediated autophagy process via blocking the nuclear human antigen R (HuR) translocation and promoting the HuR degradation, leading to a marked decrease in autophagy negative regulators EZH2, STAT1, and FOXK1. In conclusion, hucMSCs treatment significantly improved pulmonary fibrosis by downregulating the circFOXP1-HuR-EZH2/STAT1/FOXK1 autophagic axis. hucMSCs can act as an effective treatment for pulmonary fibrosis.

Human umbilical cord mesenchymal stem cells-derived exosomal circDLGAP4 promotes angiogenesis after cerebral ischemia-reperfusion injury by regulating miR-320/KLF5 axis.

Accumulating evidence suggests that human umbilical cord mesenchymal stem cell-derived exosomes (hUC-MSCs-Exos) are a promising therapeutic strategy for cerebral ischemia-reperfusion injury (CIRI). However, the underlying mechanism remains unclear. hUC-MSCs-Exos were identified by electron microscopy, NTA, and Western blotting. In the hypoxia/reoxygenation (H/R) cell model, human brain microvascular endothelial cells (HBMECs) were cocultured with hUC-MSCs-Exos. Then, cell viability, migration, apoptosis, and tube formation were measured by MTT, flow cytometry, transwell, and tube formation assays. RT-qPCR and Western blotting were used to detect the changes in RNA and protein. RNA pull-down and dual luciferase reporter assays confirmed the relationship between circDLGAP4, miR-320, and KLF5. Ischemia-reperfusion (I/R) rat model was established for in vivo experiments. hUC-MSCs-Exos increased the expression levels of circDLGAP4 and KLF5 but decreased miR-320 in H/R-treated HBMECs by transferring exosomal circDLGAP4. Knockdown of circDLGAP4 in hUC-MSCs-Exos reversed the promoting effects of hUC-MSCs-Exos on cell viability, migration, and tube formation in H/R-treated HBMECs in vitro and also abolished the protective effects of hUC-MSCs-Exos on cerebrovascular injury in I/R rats. Mechanistically, exosomal circDLGAP4 negatively regulated miR-320 in HBMECs, which directly bound to KLF5. In addition, the downregulation of miR-320 could reverse the regulatory effect of exosomal shcircDLGAL5 in H/R-treated HBMECs by upregulating KLF5. hUC-MSCs-Exos-derived circDLGAP4 reduced cerebrovascular injury by regulating miR-320/KLF5 signaling. These results provide a stem cell-based approach to treat CIRI.

Extracellular vesicles derived from "serum and glucose" deprived HUCMSCs promoted skin wound healing through enhanced angiogenesis.

Extracellular vesicles (EVs) produced from MSCs were currently considered as a novel therapeutic agent for skin tissue regeneration and repair. Preconditioning stem cells may activate more molecular pathways and release more bioactive agents. In this study, we obtained EVs from normal (N-EVs) and serum- and glucose-deprived (SGD-EVs) human umbilical cord mesenchymal stem cells (HUCMSCs), and showed that SGD-EVs promoted the migration, proliferation, and tube formation of HUVECs in vitro. In vivo experiments utilizing a rat model show that both N-EVs and SGD-EVs boosted angiogenesis of skin defects and accelerated skin wound healing, while treating wounds with SGD-EVs led to faster skin healing and enhanced angiogenesis. miRNA sequencing showed that miR-29a-3p was abundant in SGD-EVs, and overexpressing miR-29a-3p enhanced the angiogenic ability of HUVECs, while inhibiting miR-29a-3p presented the opposite effect. Further studies demonstrated that miR-29a-3p directly targeted CTNNBIP1, which mediated angiogenesis of HUCMSCs-derived EVs through inhibiting CTNNBIP1 to activate Wnt/ß-catenin signaling pathway. Taken together, these findings suggested that SGD-EVs promote angiogenesis via transferring miR-29a-3p, and activation of Wnt/ß-catenin signaling pathway played a crucial role in SGD-EVs-induced VEGFA production during wound angiogenesis. Our results offered a new avenue for modifying EVs to enhance tissue angiogenesis and augment its role in skin repair.

Exosomes derived from human umbilical cord mesenchymal stem cells decrease neuroinflammation and facilitate the restoration of nerve function in rats suffering from intracerebral hemorrhage.

Exosomes derived from human umbilical cord mesenchymal stem cells (hUCMSC-ex) have become a hopeful substitute for whole-cell therapy due to their minimal immunogenicity and tumorigenicity. The present study aimed to investigate the hypothesis that hUCMSC-ex can alleviate excessive inflammation resulting from intracerebral hemorrhage (ICH) and facilitate the rehabilitation of the nervous system in rats. In vivo, hemorrhagic stroke was induced by injecting collagenase IV into the striatum of rats using stereotactic techniques. hUCMSC-ex were injected via the tail vein at 6 h after ICH model establishment at a dosage of 200 µg. In vitro, astrocytes were pretreated with hUCMSC-ex and then stimulated with hemin (20 µmol/mL) to establish an ICH cell model. The expression of TLR4/NF-κB signaling pathway proteins and inflammatory factors, including TNF-α, IL-1ß, and IL-10, was assessed both in vivo and in vitro to investigate the impact of hUCMSC-ex on inflammation. The neurological function of the ICH rats was evaluated using the corner turn test, forelimb placement test, Longa score, and Bederson score on the 1st, 3rd, and 5th day. Additionally, RT-PCR was employed to examine the mRNA expression of TLR4 following hUCMSC-ex treatment. The findings demonstrated that hUCMSC-ex downregulated the protein expression of TLR4, NF-κB/P65, and p-P65, reduced the levels of pro-inflammatory cytokines TNF-α and IL-1ß, and increased the expression of the anti-inflammatory cytokine IL-10. Ultimately, the administration of hUCMSC-ex improved the behavioral performance of the ICH rats. However, the results of PT-PCR indicated that hUCMSC-ex did not affect the expression of TLR4 mRNA induced by ICH, suggesting that hUCMSCs-ex may inhibit TLR4 translation rather than transcription, thereby suppressing the TLR4/NF-κB signaling pathway. We can conclude that hUCMSC-ex mitigates hyperinflammation following ICH by inhibiting the TLR4/NF-κB signaling pathway. This study provides preclinical evidence for the potential future application of hUCMSC-ex in the treatment of cerebral injury.

Allogenic umbilical cord-derived mesenchymal stromal cells improve motor function in prenatal surgical repair of myelomeningocele: An ovine model study.

OBJECTIVE: To investigate the effects of an adjuvant allogenic umbilical cord mesenchymal stromal cell (UC-MSC) patch applied during fetal surgery on motor and sphincter function in the ovine MMC model. DESIGN: MMC defects were surgically created at 75 days of gestation and repaired 14 days later. POPULATION: Ovine MMC model: fetal lambs. METHODS: We compared lambs that received a UC-MSC patch with a control group of lambs that received an acellular patch. MAIN OUTCOME MEASURES: Clinical neurological assessment was performed at 2 and 24 hours of life and included determination of the Sheep Locomotor Rating scale (SLR), which has been validated in the ovine MMC model. Electrophysical examinations, spine scans and histological analyses were also performed. RESULTS: Of the 13 operated lambs, nine were born alive: five had of these had received a UC-MSC patch and four an acellular patch. At 24 hours of life, lambs in the UC-MSC group had a significantly higher score (14 versus 5, P = 0.04). Amyotrophy was significantly more common in the control group (75% versus 0%, P = 0.02). All the lambs in the control group and none of those in the UC-MSC group were incontinent. No significant differences were observed between the UC-MSC and control groups in terms of the presence of spontaneous EMG activity, nerve conduction or spinal evoked potentials. In the microscopic examination, lambs in the UC-MSC group had less fibrosis between the spinal cord and the dermis (mean thickness, 453 versus 3921 µm, P = 0.03) and around the spinal cord (mean thickness, 47 versus 158 µm, P < 0.001). Examination of the spinal cord in the area of the MMC defect showed a higher large neuron density in the UC-MSC group (14.5 versus 5.6 neurons/mm2, P < 0.001). No tumours were observed. CONCLUSIONS: Fetal repair of MMC using UC-MSC patches improves motor and sphincter function as well as spinal preservation and reduction of fibrosis.

MSC microvesicles loaded G-quadruplex-enhanced circular single-stranded DNA-9 inhibits tumor growth by targeting MDSCs.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) promote tumor growth, metastasis, and lead to immunotherapy resistance. Studies revealed that miRNAs are also expressed in MDSCs and promote the immunosuppressive function of MDSCs. Currently, few studies have been reported on inducible cellular microvesicle delivery of nucleic acid drugs targeting miRNA in MDSCs for the treatment of malignant tumors. RESULTS AND CONCLUSION: In this study, we designed an artificial DNA named G-quadruplex-enhanced circular single-stranded DNA-9 (G4-CSSD9), that specifically adsorbs the miR-9 sequence. Its advanced DNA folding structure, rich in tandem repeat guanine (G-quadruplex), also provides good stability. Mesenchymal stem cells (MSCs) were prepared into nanostructured vesicles by membrane extrusion. The MSC microvesicles-encapsulated G4-CSSD9 (MVs@G4-CSSD9) was delivered into MDSCs, which affected the downstream transcription and translation process, and reduced the immunosuppressive function of MDSCs, so as to achieve the purpose of treating melanoma. In particular, it provides an idea for the malignant tumor treatment.

Comparative study on the efficacy of PRP gel and UC-MSCs gel as adjuvant therapies in the treatment of DFU wounds.

BACKGROUND: Diabetic foot ulcer (DFU) is a common and serious complication of diabetes, and its treatment is challenging. Platelet-rich plasma (PRP) gel and umbilical cord mesenchymal stem cells (UC-MSCs) gel have been concerned as new therapies for DFU in recent years, and comparative studies on the efficacy and mechanisms of these methods, however, are rarely reported. METHODS: Thirty patients with DFU were selected and divided into the PRP group and the UC-MSCs group, and wound healing, foot blood vessels (ABI index), infection index (CRP), neuropathy symptoms (TCSS score), and foot skin temperature before and after treatment were compared between the two groups. SPSS 21.0 was used for statistical analysis. RESULTS: The results showed that the efficacy of the UC-MSCs gel group was significantly better than that of the PRP group in terms of wound healing rate, time to complete wound closure, ABI index, CRP level and TCSS score. No statistically significant difference in foot skin temperature was observed between the two groups. CONCLUSION: The efficacy of UC-MSCs gel is significantly superior to that of PRP gel in the treatment of DFU, with shortened time to complete wound closure, increased wound healing rate, better pain and infection control, and improved vascular and neurological symptoms.

The Combined Anti-Aging Effect of Hydrolyzed Collagen Oligopeptides and Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells on Human Skin Fibroblasts.

Stem cell-derived exosomes (SC-Exos) are used as a source of regenerative medicine, but certain limitations hinder their uses. The effect of hydrolyzed collagen oligopeptides (HCOPs), a functional ingredient of SC-Exos is not widely known to the general public. We herein evaluated the combined anti-aging effects of HCOPs and exosomes derived from human umbilical cord mesenchymal stem cells (HucMSC-Exos) using a senescence model established on human skin fibroblasts (HSFs). This study discovered that cells treated with HucMSC-Exos + HCOPs enhanced their proliferative and migratory capabilities; reduced both reactive oxygen species production and senescence-associated ß-galactosidase activity; augmented type I and type III collagen expression; attenuated the expression of matrix-degrading metalloproteinases (MMP-1, MMP-3, and MMP-9), interleukin 1 beta (IL-1ß), and tumor necrosis factor-alpha (TNF-α); and decreased the expression of p16, p21, and p53 as compared with the cells treated with HucMSC-Exos or HCOPs alone. These results suggest a possible strategy for enhancing the skin anti-aging ability of HucMSC-Exos with HCOPs.

HMSCs exosome-derived miR-199a-5p attenuates sulfur mustard-associated oxidative stress via the CAV1/NRF2 signalling pathway.

Sulfur mustard (SM) is a blister-producing chemical warfare agent which could lead to a cascade of systemic damage, especially severe acute lung injury. Oxidative stress is considered to be vital processes for the SM toxicity mechanism. We previously proved the therapeutic effect of exosomes derived from bone marrow mesenchymal stromal cells in promoting the repair of alveolar epithelial barrier and inhibiting apoptosis. However, the key functional components in exosomes and the underlying mechanisms have not been fully elaborated. This research shed light on the function of the key components of human umbilical cord mesenchymal stem cell-derived exosomes (HMSCs-Ex). We noted that HMSCs-Ex-derived miR-199a-5p played a vital role in reducing pneumonocyte oxidative stress and apoptosis by reducing reactive oxygen species, lipid peroxidation products and increasing the activities of antioxidant enzymes in BEAS-2B cells and mouse models after exposure to SM for 24 h. Furthermore, we demonstrated that the overexpression of miR-199a-5p in HMSCs-Ex treatment induced a further decrease of Caveolin1 and the activation of the mRNA and protein level of NRF2, HO1 and NQO1, compared with HMSCs-Ex administration. In summary, miR-199a-5p was one of the key molecules in HMSCs-Ex that attenuated SM-associated oxidative stress via regulating CAV1/NRF2 signalling pathway.

Potential role of human umbilical cord stem cells-derived exosomes as novel molecular inhibitors of hepatocellular carcinoma growth.

Hepatocellular carcinoma (HCC) is one of the most critical cancers; thus, novel therapeutical regimens are of great need. In this study, we investigated the effects of umbilical cord mesenchymal stem cells (UC-MSCs) derived exosomes on HepG2 cell line, and the underlying mechanism to control HCC proliferation, to identify the potential clinical role of exosomes as a novel molecular therapeutic target. Proliferation, apoptosis, and angiogenesis effects were assessed together with the cell viability evaluation by MTT assay in HepG2 cells at 24/48 h. with or without UC-MSCs-derived exosomes. Gene expressions of TNF-α, caspase-3, VEGF, stromal cell-derived factor-1 (SDF-1), and CX chemokine receptor-4 (CXCR-4) were measured by quantitative real-time PCR technique. Expression of sirtuin-1 (SIRT-1) protein was detected by western blot. Treatment of HepG2 cells with UC-MSCs-derived exosomes for 24 and 48 h. demonstrated a significant reduction of cells survival compared to the control group (p < 0.05). The SIRT-1 protein, and VEGF, SDF-1, CXCR-4 expression levels were significantly lower, TNF-α and caspase-3 expression levels were significantly higher in exosomal-treated HepG2 cells for 24 and 48 h. than those in the control group. Moreover, our findings documented that the anti-proliferative, apoptotic, and anti-angiogenic effects were achieved in a time-dependent manner in which more effects were determined after 48 h supplementation compared to 24 h (p < 0.05). UC-MSCs-derived exosomes exert anticarcinogenic molecular effects on HepG2 cells through the involvement of SIRT-1, SDF-1, and CXCR-4. Hence, exosomes would be a potential novel therapy regimen against HCC. Large-scale studies are recommended to verify this conclusion.

Human umbilical cord mesenchymal stem cell-derived exosomes carrying miR-1827 downregulate SUCNR1 to inhibit macrophage M2 polarization and prevent colorectal liver metastasis.

microRNA-1827 (miR-1827) is proposed to be enriched in exosomes from mesenchymal stem cells (MSCs-Exos). A recent study has addressed the suppressive effect of exosomes from human umbilical cord mesenchymal stem cells (hUC-MSCs-Exos) on colorectal cancer (CRC) metastasis. Hence, our study aims at investigating whether hUC-MSCs-Exos can modulate the liver metastasis in CRC by mediating miR-1827. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were used to identify hUC-MSCs-Exos. Using gain- and loss-of-function approaches, the expression of miR-1827 and succinate receptor 1 (SUCNR1) was altered. Consequently, the biological functions of CRC cells were assessed by CCK-8 and Transwell assays and macrophage M2 polarization was assayed by flow cytometry. Dual-luciferase reporter assay was applied to clarify interaction between miR-1827 and SUCNR1. CRC cells were incubated with hUC-MSCs-Exos and tumor-bearing mice were injected with hUC-MSCs-Exos to examine the effects on CRC cell growth and metastasis. SUCNR1, lowly expressed in CRC, could promote CRC cell growth and macrophage M2 polarization. miR-1827 could target SUCNR1 and hence suppress the progression and metastasis of CRC. hUC-MSCs-Exos carried miR-1827 to inhibit M2 macrophage polarization by downregulating SUCNR1 expression, and inhibited proliferating, migrating and invading properties of CRC cells. Furthermore, hUC-MSCs-Exos carrying miR-1827 blocked CRC liver metastasis in vivo. These findings indicate hUC-MSCs-Exos as an inhibitor of M2 macrophage polarization and liver metastasis in CRC through inducing miR-1827-targeted inhibition of SUCNR1. This provides a theoretical basis for understanding the mechanisms underlying Exos-based target therapy for CRC.

Differentiation of umbilical cord mesenchymal stem cells into hepatocytes with CYP450 metabolic enzyme activity induced by a liver injury microenvironment.

The aim of this study was to observe the effect of a simulated liver tissue injury microenvironment on the directed differentiation of umbilical cord mesenchymal stem cells into hepatocytes with CYP450 metabolic activity in vitro, and to explore the mechanisms underlying this directed differentiation. Normal and damaged liver tissue homogenate supernatants (LHS and CCl4-LHS, respectively) were used as induction fluids. After induction for different durations, Western blot and RT-PCR were used to measure the protein and gene expression of the hepatocellular proteins AFP, CK18, ALB, and the CYP450 family. Simultaneously, the metabolic activity of CYP450 in hepatocytes was determined. Compared with the LHS and CCl4-LHS controls, the LHS and CCl4-LHS induction groups showed a significantly elevated protein and gene expression of AFP, CK18, ALB, CYP1A1/2, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4 (P < 0.05). The metabolic activity of CYP450 in hepatocytes was increased (P < 0.05). In addition, compared with the LHS group, the CCl4-LHS group induced cell differentiation more rapidly and with a higher efficiency. The results suggested that a liver injury microenvironment is conducive for the directed differentiation of umbilical cord mesenchymal stem cells into hepatocytes with metabolic enzyme activity.

Detrimental alteration of mesenchymal stem cells by an articular inflammatory microenvironment results in deterioration of osteoarthritis.

BACKGROUND: Articular injection of mesenchymal stem cells (MSCs) has been applied to treat knee osteoarthritis (kOA), but its clinical outcomes are controversial. This study investigated whether an articular inflammatory microenvironment (AIM) impacts MSC-based therapy in a rat model of kOA. METHODS: The biological change of MSCs and the functional change of MSCs on chondrocytes were evaluated under AIM. The key mediator and mechanism for the AIM impact on MSC therapy were explored via gain- and loss-of-function approaches. RESULTS: The results showed that MSCs exerted potent anti-kOA effects in vivo and in vitro, but that this therapy become chondrodestructive if a chronic AIM was present. Mechanistically, the overexpression of MMP13 in the injected MSCs via a MAPKs-AP1 signaling axis was revealed as the underlying mechanism for the detriment outcome. CONCLUSIONS: This study thus clarifies recent clinical findings while also suggesting a means to overcome any detrimental effects of MSC-based therapy while improving its efficacy.

Pretreatment of UC-MSCs with IFN-α2 improves treatment of liver fibrosis by recruiting neutrophils.

BACKGROUND: The use of umbilical cord mesenchymal stem cells (UC-MSCs) is a burgeoning method for the treatment of liver cirrhosis. However, the secretory phenotype and regulatory ability of UC-MSCs are easily affected by their microenvironment. Ensuring a specific microenvironment to enhance the UC-MSCs phenotype is a potential strategy for improving their therapeutic efficacy. The aim of this study was to explore therapeutic UC-MSCs phenotypes for improving liver fibrosis. METHODS: RNA-sequencing was used to analyze the response pattern of UC-MSCs after exposure to the serum of cirrhotic patients with HBV. Using immunohistochemistry, quantitative polymerase chain reaction, and immunofluorescence techniques, we evaluated the therapeutic effect of UC-MSCs pretreated with interferon alpha 2 (IFN-α2) (pre-MSCs) in an animal model of cirrhosis. Immunoblotting, ELISA, and other techniques were used to analyze the signaling pathways underlying the IFN-induced changes in UC-MSCs. RESULTS: UC-MSCs exposed to the serum of patients with hepatitis B-induced cirrhosis showed an enhanced response to type I IFN. The activated type I IFN signal induced the highest secretion of colony-stimulating factor 3 (CSF-3), interleukin (IL)-8, and chemokine (C-C motif) ligand 20 (CCL20) by the UC-MSCs. Pre-MSCs showed a higher therapeutic efficacy than untreated UC-MSCs in an animal model of liver fibrosis. Immunohistochemical analysis revealed that pre-MSCs could recruit neutrophils resulting in an increase in the secretion of matrix metalloprotease 8 that alleviated fibrosis. When neutrophils in animals were depleted, the therapeutic effect of pre-MSCs on fibrosis was inhibited. IFN-α2 altered the secretory phenotype of UC-MSCs by activating phosphorylated signal transducer and activator of transcription 1 and 2 (p-STAT1 and p-STAT2). CONCLUSIONS: Pre-MSCs exhibited enhanced secretion of CSF-3, IL-8, and CCL20 and recruited neutrophils to alleviate fibrosis. This new strategy can improve cell therapy for liver cirrhosis.

Curcumin-Primed Umbilical Cord Mesenchymal Stem Cells-Derived Extracellular Vesicles Improve Motor Functional Recovery of Mice with Complete Spinal Cord Injury by Reducing Inflammation and Enhancing Axonal Regeneration.

Background Transplantation of extracellular vesicles (EVs) from stem cells is a feasible scheme for traumatic spinal cord injury (SCI). However, there is no relevant report about stem cells derived EVs loaded with curcumin for SCI treatment. Methods Mouse umbilical cord mesenchymal stem cells (MUMSCs) were incubated in the medium containing curcumin (20 µM) for 48 h. Extracellular vesicles (EVs) and curcumin-primed EVs (Cur-EVs) were collected by ultracentrifugation. Characterizations of EVs/Cur-EVs were analyzed by western blotting with CD9 and CD81 antibodies, transmission electron microscopy and nano-tracking analysis. Curcumin in the Cur-EVs was analyzed by high performance liquid phase chromatography at 430 nm wavelength. Immunofluorescence and in vivo imaging methods were used to confirm biocompatibility of EVs/Cur-EVs in vitro and in vivo. Mice with complete SCI were treated with EVs/Cur-EVs to compare the differences of locomotor function, inflammation, histological changes and remyelination. Results The isolated EVs and Cur-EVs from MUMSCs have good biocompatibility. Compared with the model mice, the locomotor function, inflammation and axonal regeneration of mice were significantly improved after injection of Cur-EVs/EVs. Furthermore, it is more effective for structural and functional recovery of complete SCI after the Cur-EVs treatment compared with the EVs treatment. In the lesioned regions, the macrophage polarization from M1 to M2 phenotype and axonal regeneration were significantly improved in the Cur-EVs group compared with the EVs group. Conclusions Our data suggested that EVs from MUMSCs might be a promising drug delivery vehicle of curcumin for the efficient and biocompatible treatment of severe SCI.