Mesenchymal Cells Research Articles

HUCMSCs Regulate Bile Acid Metabolism to Prevent Heart Failure–Induced Intestinal Injury by Inhibiting the Activation of the STAT3/NF‐κB/MAPK Signaling Pathway via TGR5

ABSTRACTThe protective effects of human umbilical cord mesenchymal stem cells (hUCMSCs) on heart failure (HF)‐induced intestinal injury have not been fully understood. Flow cytometry and immunofluorescence analysis revealed that hUCMSCs renewed themselves, grew, and transformed into various cell types. Meanwhile, hUCMSCs safeguarded against intestinal damage, regulated imbalances in the intestinal flora and bile acid metabolism, and enhanced the levels of hyodeoxycholic acid (HDCA) in pigs with HF. HDCA protected against HF‐induced intestinal injury in mice through Takeda G protein–coupled receptor 5 (TGR5). Protein analysis showed that HDCA exerted protective effects on the intestines via the signal transducer and activator of transcription 3 (STAT3)/nuclear factor kappa B (NF‐κB)/mitogen‐activated protein kinase (MAPK) signaling pathway. Mouse experiments revealed that HDCA bound to TGR5 to inhibit MAPK and NF‐κB signaling pathway activation, which relies on the STAT3 signaling pathway. Moreover, hUCMSCs protected against intestinal injury in the pig model of HF by suppressing the activation of the STAT3/NF‐κB/MAPK signaling pathway via TGR5.

Conditioned Extracellular Vesicles Derived from Dedifferentiated Fat Cells Promote Bone Regeneration by Altering MicroRNAs

Background: Extracellular vesicles (EVs) derived from stem cells demonstrate significant potential in bone regeneration. Adipose tissue is regarded as a stem cell reservoir with abundant reserves and easy accessibility. Compared to adipose-derived stem cells (ASCs), dedifferentiated fat cells (DFATs) possess similar stem cell characteristics but exhibit greater proliferative capacity, higher homogeneity, and an enhanced osteogenic differentiation potential. This study is the first to examine the effect of DFATs-derived EVs on bone regeneration and elucidate their potential mechanisms of action. Methods: Primary DFATs were cultured using the “ceiling culture” method and EVs were isolated by ultracentrifugation and characterized. Experiments were performed to assess the impact of the EVs on the proliferation, migration, and osteogenesis of bone marrow mesenchymal stem cells (BMSCs). Subsequently, high-throughput miRNA sequencing was conducted on the EVs derived from DFATs that had undergone 0 days (0d-EVs) and 14 days (14d-EVs) of osteogenic differentiation. Results: The results indicated that the EVs derived from DFATs which experienced 14 days of osteogenic induction significantly promoted the proliferation, migration, and osteogenic differentiation of BMSCs. High-throughput sequencing results revealed that up-regulated miRNAs in the 14d-EVs were primarily involved in biological processes such as the Notch signaling pathway and the positive regulation of cell movement and migration. The target genes of these differently expressed miRNAs were enriched in osteogenesis-related signaling pathways. Conclusion: This study innovatively demonstrated that conditioned EVs (14d-EVs) derived from DFATs promoted the osteogenic differentiation of BMSCs via miRNAs, offering a promising cell-free therapeutic option for bone defect.

Protective effect of bone-marrow stromal cells on injured cortical neurons subjected to hemostimulation in vitro

Objective: Bone-marrow mesenchymal stem cells (BMSCs) are a subpopulation of cells found in the bone marrow stromal of mammals that have the potential to differentiate and form bone, cartilage, adipose, neural, and muscle cells, with strong proliferative ability, multidirectional differentiation potential, immunomodulatory function. Here, we reported the novel findings on the effect of BMSC in protecting injured cortical neurons induced by hemostimulation. Methods: Cortical neurons harvested from the neonatal rat and were isolated and incubated at 37°C in a 5% CO2 environment. During this process, part of cells was subjected to hemostimulation, and BMSC derived supernatant addition was performed to observe its effect on neuroprotection. Hoechst 33342/PI co-staining and CCK-8 cell viability assays were utilized to evaluate the effects of BMSC supernatant administration on primary cortical neurons. Results: BMSC derived supernatant administration effectively protects hemoglobin-induced neuronal damage, indicating by cell viability-detection. In addition, BMSCs exert optimal effect by inhibiting neuronal cell apoptosis. Conclusions: BMSC derived supernatant treatment effectively ameliorates hemoglobin-induced neuronal damage and attenuates neuronal apoptosis.

Efficient Production of Chondrocyte Particles from Human iPSC-Derived Chondroprogenitors Using a Plate-Based Cell Self-Aggregation Technique

The limited capacity of articular cartilage for self-repair is a critical challenge in orthopedic medicine. Here, we aimed to develop a simplified method of generating chondrocyte particles from human-induced pluripotent stem cell-derived expandable limb-bud mesenchymal cells (ExpLBM) using a cell self-aggregation technique (CAT). ExpLBM cells were induced to form chondrocyte particles through a stepwise differentiation protocol performed on a CAT plate (prevelex-CAT®), which enables efficient and consistent production of an arbitrary number of uniformly sized particles. Histological and immunohistochemical analyses confirmed that the generated chondrocyte particles expressed key cartilage markers, such as type II collagen and aggrecan, but not hypertrophic markers, such as type X collagen. Additionally, when these particles were transplanted into osteochondral defects in rats with X-linked severe combined immunodeficiency, they demonstrated successful engraftment and extracellular matrix production, as evidenced by Safranin O and Toluidine Blue staining. These data suggest that the plate-based CAT system offers a robust and scalable approach to produce a large number of chondrocyte particles in a simplified and efficient manner, with potential application to cartilage regeneration. Future studies will focus on refining the system and exploring its clinical applications to the treatment of cartilage defects.

Mesenchymal stem cells: a novel therapeutic approach for feline inflammatory bowel disease

BackgroundInflammatory bowel disease (IBD) poses a significant and growing global health challenge, affecting both humans and domestic cats. Research on feline IBD has not kept pace with its widespread prevalence in human populations. This study aimed to develop a model of feline IBD by incorporating dextran sulfate sodium (DSS) to evaluate the therapeutic potential of MSCs and to elucidate the mechanisms that enhance their action.MethodsWe conducted a comprehensive clinical assessment, including magnetic resonance imaging (MRI), endoscopy, and histopathological examination. Additionally, alterations in intestinal microbiota were characterized by 16 S rDNA sequencing, and the influence of MSCs on IBD-related gene expression was investigated through transcriptome analysis.ResultsAccording to our findings, MSC treatment significantly mitigated DSS-induced clinical manifestations, reduced inflammatory cell infiltration, decreased the production of inflammatory mediators, and promoted mucosal repair. Regarding the intestinal microbiota, MSC intervention effectively corrected the DSS-induced dysbiosis, increasing the presence of beneficial bacteria and suppressing the proliferation of harmful bacteria. Transcriptome analysis revealed the ability of MSCs to modulate various inflammatory and immune-related signaling pathways, including cytokine-cytokine receptor interactions, TLR signaling pathways, and NF-κB pathways.ConclusionThe collective findings indicate that MSCs exert multifaceted therapeutic effects on IBD, including the regulation of intestinal microbiota balance, suppression of inflammatory responses, enhancement of intestinal barrier repair, and modulation of immune responses. These insights provide a solid scientific foundation for employing MSCs as an innovative therapeutic strategy for IBD and pave the way for future clinical explorations.

Mesenchymal stem cell-derived exosomes in renal ischemia-reperfusion injury: a new therapeutic strategy.

Renal ischemia-reperfusion injury (RIRI) is a serious kidney condition that causes significant damage due to lack of blood flow. This injury leads to oxidative stress and inflammation, which can cause acute tubular necrosis and kidney failure. Stem cell-derived exosomes, small vesicles released by stem cells, have shown promise in treating RIRI. Mesenchymal stem cells (MSCs) have been used to mitigate RIRI, and their exosomes have been found to play a crucial role in repairing damaged tissues. This review explores the key roles of exosomes from different sources of MSCs in RIRI, the potential of MSC-derived exosomes in treating this disease, and future research directions.

Rapid DNA Repair in Mesenchymal Stem Cells and Bone Regeneration by Nanoparticle-Based Codelivery of Nrf2-mRNA and Dexamethasone.

Directional differentiation is a key factor determining the result of stem cell therapy. Herein, we developed a polyethylenimine (PEI)-coated poly(lactic-co-glycolic) acid (PLGA) nanoparticle (mPDN) carrying both nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA and dexamethasone (Dex) to human mesenchymal stem cells (hMSCs). The combination of Dex and Nrf2-mRNA delivered by mPDN promoted the osteogenic differentiation of hMSCs. In particular, Nrf2-mRNA rapidly reduced the DNA damage caused by ROS due to early and efficient gene expression at 3 h after treatment, which was not achieved in traditional pDNA systems. High and rapid transfection, effective ROS-scavenging effect, and protection of mitochondrial dynamics were observed in hMSCs after treatment with the resulting Nrf2-mPDN. Osteogenic differentiation was also observed in 3D pellets for up to 5 weeks. Finally, the effects of rapid DNA repair in hMSCs by Nrf2-mPDN and on in vivo bone regeneration were evaluated in a rat femoral bone defect model using CT. This study demonstrated the potential of an NP-based codelivery system and efficient transfection of mRNA at early stages in hMSCs for bone regeneration and stem cell therapy.

Post-symptomatic administration of hMSCs exerts therapeutic effects in SCA2 mice

BackgroundDefects in the ataxin-2 (ATXN-2) protein and CAG trinucleotide repeat expansion in its coding gene, Atxn-2, cause the neurodegenerative disorder spinocerebellar ataxia type 2 (SCA2). While clinical studies suggest potential benefits of human-derived mesenchymal stem cells (hMSCs) for treating various ataxias, the exact mechanisms underlying their therapeutic effects and interaction with host tissue to stimulate neurotrophin expression remain unclear specifically in the context of SCA2.MethodsHuman bone marrow-derived MSCs (hMSCs) were injected into the cisterna magna of 26-week-old wild-type and SCA2 mice. Mice were assessed for impaired motor coordination using the accelerating rotarod, open field test, and composite phenotype scoring. At 50 weeks, the cerebellum vermis was harvested for protein assessment and immunohistochemical analysis.ResultsSignificant loss of NeuN and calbindin was observed in 25-week-old SCA2 mice. However, after receiving multiple injections of hMSCs starting at 26 weeks of age, these mice exhibited a significant improvement in abnormal motor performance and a protective effect on Purkinje cells. This beneficial effect persisted until the mice reached 50 weeks of age, at which point they were sacrificed to study further mechanistic events triggered by the administration of hMSCs. Calbindin-positive cells in the Purkinje cell layer expressed bone-derived neurotrophic factor after hMSC administration, contributing to the protection of cerebellar neurons from cell death.ConclusionIn conclusion, repeated administration of hMSCs shows promise in alleviating SCA2 symptoms by preserving Purkinje cells, improving neurotrophic support, and reducing inflammation, ultimately leading to the preservation of locomotor function in SCA2 mice.

The Impact of Acute Myeloblastic Leukemia-Derived Small Extracellular Vesicles on the Bone Marrow Mesenchymal Stem Cells: Expression of G1 Cell Cycle Progression Genes

Background: Leukemia progression is intricately linked to interactions with neighboring cells within the bone marrow microenvironment (BMM), and small extracellular vesicles (sEVs) emerge as vital mediators in facilitating these interactions. Objectives: This study examined the proliferation effects of sEVs-derived from acute myeloid leukemia (AML) in the HL60 cell line on the cell cycle progression of bone marrow mesenchymal stem cells (BM-MSCs), a key element of the BMM. Methods: Small extracellular vesicles were isolated from the HL60 cell line supernatant, using the ExoCib kit, and characterized through flow cytometry, transmission electron microscopy (TEM), dynamic light scattering (DLS), and bicinchoninic acid (BCA) protein assay. bone marrow mesenchymal stem cells were cultured and treated with various concentrations (20 μg/mL, 50 μg/mL, and 80 μg/mL) of AML-derived sEVs for 24, 48, and 72 hours. The effects on cell proliferation and viability were assessed, using methylthiazole tetrazolium test (MTT) and Ki-67 assays, while cell cycle progression and apoptosis were analyzed via flow cytometry. RT-qPCR was performed to evaluate the expression levels of CCND1, CDK4, CDK6, and AKT1 genes. Results: The proliferation effects of AML-derived sEVs on BM-MSCs were both dose- and time-dependent, with optimal effects observed at 50 μg/mL after 48 hours. Flow cytometry analysis revealed a significant increase in the G1 phase, showing a 1.8-fold change compared to the control group (P < 0.0001). RT-qPCR results demonstrated a significant upregulation of CCND1 (3.5-fold, P < 0.0001), CDK4 (3.2-fold, P < 0.0001), CDK6 (2.5-fold, P < 0.0001), and AKT1 (3.2-fold, P < 0.0001) expression levels, along with increased Ki-67 (2.3-fold, P < 0.0001) levels. Moreover, treatment with 50 μg/mL of AML-derived sEVs resulted in a notable reduction in BM-MSC apoptosis (0.57-fold decrease, P < 0.0001). Conclusions: Our findings revealed that AML extracellular vesicles could alter the gene expression associated with the proliferation of BMSCs to increase their proliferation by stimulating the cell cycle of MSCs through the G1 phase.

Three-Dimensional Bioprinting of Tarsal Plates with Adipose-Derived Mesenchymal Stem Cells: Evaluation of Meibomian Gland Reconstruction in a Rat Model

Background: The aim of this study was to develop 3D-bioprinted scaffolds embedded with human adipose-derived stem cells (hADSCs) to reconstruct the tarsal plate in a rat model. Methods: Scaffolds were printed using a 3D bioprinter with a bioink composed of atelocollagen and alginate. hADSCs (5 × 105 cells/mL) were embedded within the bioink. A total of 30 male Sprague Dawley (SD) rats (300 g) were divided into three groups: group 1 (normal control, n = 10), group 2 (3D-bioprinted scaffolds, n = 10), and group 3 (3D-bioprinted scaffolds with hADSCs, n = 10). Four weeks after surgery, a histopathological analysis was performed using hematoxylin and eosin (H&E) staining, Masson’s trichrome (MT) staining, and immunofluorescence staining. Gene expression of SREBP-1, PPAR-γ, FADS-2, and FAS was assessed via real-time polymerase chain reaction (PCR). Results: No abnormalities were observed in the operated eyelids of any of the 30 rats. The histopathological analysis revealed lipid-secreting cells resembling meibocytes in both group 2 and group 3, with more pronounced meibocyte-like cells in group 3. Immunofluorescence staining for phalloidin expression showed a significant increase in group 3. Additionally, the RNA expression of SREBP-1, PPAR-γ, FADS-2, and FAS, all related to lipid metabolism, was elevated in group 3. Conclusions: The 3D-printed scaffolds combined with hADSCs were effective for tarsal plate reconstruction, with the hADSCs notably contributing to the generation of cells associated with lipid metabolism.

Mesenchymal stem cell application in pulmonary disease treatment with emphasis on their interaction with lung-resident immune cells

Due to the vital importance of the lungs, lung-related diseases and their control are very important. Severe inflammatory responses mediated by immune cells were among the leading causes of lung tissue pathology and damage during the COVID-19 pandemic. In addition, uncontrolled immune cell responses can lead to lung tissue damage in other infectious and non-infectious diseases. It is essential to control immune responses in a way that leads to homeostasis. Immunosuppressive drugs only suppress inflammatory responses and do not affect the homeostasis of reactions. The therapeutic application of mesenchymal stem cells (MSCs), in addition to restoring immune homeostasis, can promote the regeneration of lung tissue through the production of growth factors and differentiation into lung-related cells. However, the communication between MSCs and immune cells after treatment of pulmonary diseases is essential, and investigating this can help develop a clinical perspective. Different studies in the clinical phase showed that MSCs can reverse fibrosis, increase regeneration, promote airway remodeling, and reduce damage to lung tissue. The proliferation and differentiation potential of MSCs is one of the mechanisms of their therapeutic effects. Furthermore, they can secrete exosomes that affect the function of lung cells and immune cells and change their function. Another important mechanism is that MSCs reduce harmful inflammatory responses through communication with innate and adaptive immune cells, which leads to a shift of the immune system toward regulatory and hemostatic responses.

STEM CELL APPROACHES IN ORGAN REGENERATION AND REPAIR

Recent advances in stem cell research have provided new hope for treating a variety of diseases and conditions that currently have no effective cure. Stem cells have the unique ability to differentiate into various cell types, enabling them to support tissue growth and replace damaged or specialized cells throughout the lifespan. Among the most promising types of stem cells are mesenchymal stem cells (MSCs), which are easily harvested from adipose tissue and can be cultured and expanded in the lab. Due to their versatility, MSCs have become a focal point in tissue regeneration and have been widely used in animal studies and clinical trials involving humans. This review aims to summarize the current understanding of MSCs, focusing on the various types of stem cells isolated from different animal models such as horses, pigs, goats, dogs, rabbits, cats, rats, and mice. Given the growing interest in MSCs, we will also discuss their applications in veterinary and regenerative medicine. Current research highlights the potential of MSCs in treating conditions like heart failure, wound healing, and tooth regeneration, demonstrating their broad therapeutic potential. KEYWORDS: Mesenchymal stem cells (MSCs), animal models, cell-based therapy, regenerative medicine

Intraosseous Delivery of Mesenchymal Stem Cells for the Treatment of Bone and Hematological Diseases

Mesenchymal stem cells are used most in regenerative medicine due to their capacities in differentiation and immune modulation. The intraosseous injection of MSC into the bone has been recommended because of expected outcomes for retention, bioavailability, and enhanced therapeutic efficacy, particularly in conditions involving the bone, such as osteoporosis and osteonecrosis. A review of the intraosseous delivery of mesenchymal stem cells in comparison with intravenous and intra-arterial delivery methods will be subjected to critical examination. This delivery mode fares better regarding paracrine signaling and immunomodulation attributes, which are the cornerstone of tissue regeneration and inflammation reduction. The local complications and technical challenges still apply with this method. This study was more focused on further research soon to be conducted to further elucidate long-term safety and efficacy of intraosseous mesenchymal stem cell therapy. Though much has been achieved with very impressive progress in this field, it is worth noting that more studies need to be put into place so that this technique can be established as a routine approach, especially with further research in biomaterials, gene therapy, and personalized medicine.

A comprehensive evaluation system for ultrasound-guided infusion of human umbilical cord-derived MSCs in liver cirrhosis patients.

Infusion of mesenchymal stem cells (MSCs) via portal vein is one of the main ways for MSCs transplantation to treat liver cirrhosis (LC). As the tissue of LC showed diffuse fibrosis and thickened Glission sheath, the soft pig-tail catheter, or central venous catheter can not successfully insert the portal vein. Thus, our study used an improved method and performed a relatively comprehensive system to evaluate the effect for human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) transplantation. Fifteen patients with hepatitis B-related cirrhosis were enrolled in the study, and we performed hUC-MSCs transplantation via portal vein by using an 16-G needle and 0.035-inch guide wire combined with 7FR "retentional metal stiffner trocar" of pig-tail catheter under the guidance of contrast-enhanced ultrasound. Serum liver function, fibrotic indicators, tissue stiffness, coagulation function, and hemodynamics were measured at weeks 4, 12, and 24 after MSCs transplantation. Liver biopsy was performed before and 24 weeks after hUC-MSCs transplantation. After hUC-MSCs transplantation, the prothrombin time was lower than before. The levels of hyaluronic acid and IV-C(Type IV collagen) in fibrotic indicators were significantly reduced, and the Young's modulus was also decreased. Moreover, liver biopsy showed that the lytic necrosis of hepatocyte was decreased. In liver hemodynamics, the portal vein diameter was decreased after hUC-MSCs transplantation. hUC-MSCs transplantation can alleviate liver damage caused by LC. The improved "retentional metal stiffner trocar" of pig-tail catheter was safe and effective in the infusion of hUC-MSCs transplantation, which is worth promoting in clinical practice.

MicroRNA-505-5p/-3p Regulates the Proliferation, Invasion, Apoptosis, and Temozolomide Resistance in Mesenchymal Glioma Stem Cells by Targeting AUF1.

Mesenchymal glioma stem cells (MES-GSCs) are a major subtype of GSCs that reside within glioma tissues and contribute to metastasis, therapy resistance, and glioma recurrence. However, the precise molecular mechanisms governing MES-GSC functions remain elusive. Our findings revealed that expression levels of miR-505-5p/-3p are elevated in MES-GSCs compared with those in proneural (PN)-GSCs, glioma cell lines, and normal brain tissue and that miR-505-5p/-3p expression levels are decreased in differentiated MES-GSCs. We assumed that miR-505-5p/-3p would play distinctive roles in MES-GSCs and performed loss-of-function experiments targeting miR-505-5p/-3p. Knockdown of miR-505-5p/-3p increased proliferation and promoted differentiation in MES-GSCs while suppressing invasion, temozolomide resistance, and enhancing apoptosis in MES-GSCs. Mechanistically, miR-505-5p/-3p directly targets the 3' UTR of AUF1, leading to its repression in MES-GSCs. Notably, AUF1 expression levels were significantly lower in MES-GSCs compared with those in PN-GSCs, glioma cell lines, and normal brain tissues. Co-inhibition of AUF1 expression with miR-505-5p/-3p knockdown ameliorated the observed cellular phenotypes caused by miR-505-5p/-3p knockdown in MES-GSCs. These results suggest that miR-505-5p/-3p exerts MES-GSC-specific roles in regulating proliferation, differentiation, invasion, apoptosis, and temozolomide resistance by repressing AUF1 expression.

The Expression Level of Inflammation-Related Genes in Patients With Bone Nonunion and the Effect of BMP-2 Infected Mesenchymal Stem Cells Combined With nHA/PA66 on the Inflammation Level of Femoral Bone Nonunion Rats

Bone nonunion delays fracture end repair and is associated with inflammation. Although bone nonunion can be effectively repaired in clinical practice, many cases of failure. Studies have confirmed that BMP-2 and nHA/PA66 repaired bone defects successfully. There are few studies on the effects of the combined application of BMP-2 and NHA/PA66 on bone nonunion osteogenesis and inflammation. We aimed to investigate the expression level of inflammation-related genes in patients with bone nonunion and the effect of BMP-2-infected mesenchymal stem cells combined with nHA/PA66 on the level of inflammation in femur nonunion rats. We searched for a gene expression profile related to bone nonunion inflammation (GSE93138) in the GEO public database. Bone marrow mesenchymal stem cells (MSCs) of SD rats were cultured and passed through. We infected the third generation of MSCs with lentivirus carrying BMP-2 and induced the infected MSCs to bone orientation. We detected the expression level of BMP-2 by RT-PCR and the cell viability and alkaline phosphatase (ALP) activity by CCK8 and then analyzed the cell adhesion ability. Finally, the levels of related inflammatory factors, including C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and Erythrocyte Sedimentation Rate (ESR), were detected in nonunion rats. Our findings: The patients with nonunion had up-regulated expression of 26 differentially inflammatory genes. These genes are mainly enriched in innate immune response, extracellular region, calcium ion binding, Pantothenate and CoA biosynthesis pathways. The expression level of BMP-2 in the Lenti-BMP-2 group was higher (vs. empty lentivirus vector group: t=5.699; vs. uninfected group t=3.996). The cell activity of the MSCs + BMP-2 + nHA/PA66 group increased gradually. After being combined with nHA/PA66, MSCs transfected with BMP-2 spread all over the surface of nHA/PA66 and grew into the material pores. MSCs + BMP-2 + nHA/PA66 cells showed positive ALP staining, and the OD value of ALP was the highest. The levels of CRP, IL-6, TNF-α, and ESR in the MSCs + BMP-2 + nHA/PA66 group were lower than those in the MSCs and MSCs + nHA/PA66 group but higher than those in MSCs + BMP-2 group. The above comparisons were all P˂0.05. The findings demonstrated that the expression level of inflammation-related genes increased in the patients with bone nonunion. The infection of MSCs by BMP-2 could promote the directed differentiation of MSCs into osteoblasts in the bone marrow of rats, enhance the cell adhesion ability and ALP activity, and reduce inflammation in rats with bone nonunion.

Bioactive Peptide Hydrogel Scaffold with High Fluidity, Thermosensitivity, and Neurotropism in 3D Spatial Structure for Promoted Repair of Spinal Cord Injury.

Spinal cord injury (SCI) has been considered a clinically challenging disease that is characterized by local disturbance of the microenvironment, which inhibits post-injury neural regeneration. The simulation of a microenvironment conducive to the regeneration of spinal cord is beneficial for SCI repair. In this study, bioactive composite hydrogels are developed that mimic the regenerative microenvironment of spinal cord for enhanced SCI repair. The fabricated composite hydrogels (CRP) based on chitosan (CS), RADA16 nanofibers, and nerve-promoted peptide (PPFLMLLKGSTR) exhibit excellent injectability, superior biodegradability and biocompatibility. In addition, the CRP hydrogels can formquickly (a few minutes) by mixing three components at human body temperature, showing high potential as a biomimetic matrix for in situ repair of SCI. The in vitro studies demonstrate that the CRP hydrogels can not only promote the proliferation and migration of bone marrow mesenchymal stem cells but also induce the proliferation and differentiation of neural stem cells (NSCs) into neurons. Meanwhile, the hydrogels reveal the efficiency of protecting neurons and promoting axonal growth. Furthermore, the in vivo tests prove that the CRP hydrogels can reduce post-SCI inflammatory responses, inhibit reactive astrocyte over-proliferation, and promote the migration, proliferation, and differentiation of endogenous NSCs, which agree well with the in vitro results. The pre-clinical test demonstrates that the CRP hydrogels restore the motor function in completely transected spinal cord rats, and the SCI repair mechanism may involve the activation of the PI3K/AKT/mTOR pathway. It is believed that the strategies shown in this work will be valuable for the design and synthesis of novel hydrogels for biomedical and tissue engineering applications.

Umbilical cord mesenchymal stem cells combined with autologous platelet-rich plasma for lower extremity venous ulcers: A case report and literature review.

Nonhealing ulcers are difficult to manage because they deviate from the normal wound healing process. Conventional therapy cannot achieve satisfactory therapeutic effects. To verify the effectiveness of combined treatment with human umbilical cord mesenchymal stem cells (hUMSCs) and platelet-rich plasma (PRP) for nonhealing ulcers, we studied a patient with left lower limb venous ulcer (LEVU) treated with combined injection therapy. We present the case of a LEVU patient who has not healed for a long period of time (up to 1 year). LEVU was diagnosed with clinical symptoms. The hUMSCs plus PRP were injected into the wound edge and base (1 µL of cells/cm2 of wound surface), 0.5 mL at each point, with a distance of approximately 1 to 3 cm between points. The injection point was determined according to the extent of wound involvement. Seven days after hUMSC + PRP application, the wound area decreased by nearly 50%. The ulcers had almost completely healed by day 62, and no serious treatment-related toxic side effects were observed. hUMSCs can improve wound healing through re-epithelialization, increased angiogenesis, and granulation tissue formation. PRP has also been suggested to promote wound healing through the secretion of various nutritional factors. The combination of hUMSCs and PRP has a mutually reinforcing effect, which may achieve a 1 + 1 > 2 effect. Therefore, the combination of hUMSCs and PRP may be a safe and effective treatment option for LEVU.

Dental Pulp Stem Cell Conditioned Medium Enhance Osteoblastic Differentiation and Bone Regeneration.

Cell-free approaches, utilizing mesenchymal stem cell secretome, have promising prospects in various fields of regenerative medicine. In this study, we examined in vitro and in vivo the potential of dental pulp stem cell-conditioned medium (DPSC-CM) for bone regeneration. The secretome of undifferentiated stem cells from dental pulp were collected, and the effects of this DPSC-CM were assessed for osteodifferentiation of osteoblast-like cells (MG-63) and osteoblasts deriving from DPSC. Cell proliferation, alkaline phosphatase (ALP) activity, gene expression of Runt-related transcription factor 2 (Runx2), Bone Sialoprotein (BSP), Osteocalcin (OCN), and extracellular matrix mineralization were evaluated. The rat caudal vertebrae critical size defect model was to investigate the effect of DPSC-CM in vivo. Results showed that DPSC-CM induced cell growth, and increased ALP activity and the expression of key marker genes at an early stage of osteoblastic differentiation compared to control. A rat bone defect model was used to illustrate the effect of DPSC-CM in vivo. The bone density within the defects were improved using conditioned medium, even though there was no significant difference between the control and DPSC-CM groups. The analysis of DPSC-CM by human growth factor antibody array revealed the presence of several factors involved in osteogenesis. Taken together, these findings indicate that DPSC-CM is a promising therapeutic candidate for bone regenerative therapy, accelerating the maturation of osteoblastic cells. And even though safety and efficiency of DPSC-CM have to be confirmed in preclinical studies, these results represent a first step toward clinical application.

Extracellular vesicles derived from bone marrow mesenchymal stem cells ameliorate liver fibrosis via micro-7045-5p.

Liver fibrosis is a crucial pathological factor in the persistence and progression of chronic liver disease. Increasing evidence has demonstrated the significant potential of extracellular vesicles (EVs) secreted by bone marrow mesenchymal stem cells (BMSCs) in the clinical treatment of liver fibrosis. This study aimed to mechanistically investigate the impact of BMSC-derived EVs (BMSC-EVs) containing miR-7045-5p on the autophagy of activated hepatic stellate cells (HSCs) during liver fibrosis. BMSCs were isolated from the bilateral femurs and tibiae of mice. Their identity was confirmed via immunofluorescence staining for the BMSC marker CD44. EVs were harvested from BMSC culture medium at passages 3-5 and then DiR-labeled. Labeled BMSC-EVs were co-cultured with the HSC-T6 cell line to determine their uptake and sub-cellular localization in HSCs. Various methods, such as western blotting, qRT-PCR, and ELISA, were employed to assess the effects of BMSC-EVs on the fibrotic activation (marked by COL1-A1 and α-SMA expression) and autophagy (p62, Atg16L1, Beclin-1, and LC3 expression) of HSC-T6 cells. Additionally, the BMSC-EV-induced changes in autophagy-related signaling pathways (PI3K, AKT, and mTOR pathways) in these cells were evaluated. Finally, the gene-chip detection technology was utilized to predict the involvement of BMSC-EV-derived miRNAs (BMSC-EV-miRs) in the observed effects, with a focus on miR-7045-5p, and our findings were validated in HSCs transfected with a miR-7045-5p mimic. The gene-chip detection results indicated that miR-7045-5p was enriched in BMSC-EVs compared with BMSCs and targeted Akt. In the CCl4-induced mouse model of liver fibrosis, BMSC-EV-miR-7045-5p ameliorated the fibrosis and enhanced liver function by suppressing the PI3K/Akt/mTOR signaling pathway. Additionally, miR-7045-5p inhibited TGF-β1-induced fibrotic activation of HSC-T6 cells. BMSC-EVs promote autophagy in HSC-T6 cells and alleviate liver fibrosis by inhibiting the PI3K/Akt/mTOR signaling pathway at least in part by delivering anti-fibrotic miRNAs, such as miR-7045-5p.