Mesenchymal Cells Research Articles

Concrete-Inspired Bionic Bone Glue Repairs Osteoporotic Bone Defects by Gluing and Remodeling Aging Macrophages.

Osteoporotic fractures are characterized by abnormal inflammation, deterioration of the bone microenvironment, weakened mechanical properties, and difficulties in osteogenic differentiation. The chronic inflammatory state characterized by aging macrophages leads to delayed or non-healing of the fracture or even the formation of bone defects. The current bottleneck in clinical treatment is to achieve strong fixation of the comminuted bone fragments and effective regulation of the complex microenvironment of aging macrophages. Inspired by cement and gravel in concrete infrastructure, a biomimetic bone glue with poly(lactic-co-glycolic acid) microspheres is developed and levodopa/oxidized chitosan hydrogel stabilized on an organic-inorganic framework of nanohydroxyapatite, named DOPM. DOPM is characterized via morphological and mechanical characterization techniques, in vitro experiments with bone marrow mesenchymal stromal cells, and in vivo experiments with an aged SD rat model exhibiting osteoporotic bone defects. DOPM exhibited excellent adhesion properties, good biocompatibility, and significant osteogenic differentiation. Transcriptomic analysis revealed that DOPM improved the inflammatory microenvironment by inhibiting the NF-κB signaling pathway and promoting aging macrophage polarization toward M2 macrophages, thus significantly accelerating bone defect repair and regeneration. This biomimetic bone glue, which enhances osteointegration and reestablishes the homeostasis of aging macrophages, has potential applications in the treatment of osteoporotic bone defects.

Injectable calcium phosphate cement integrated with BMSCs-encapsulated microcapsules for bone tissue regeneration

Injectable calcium phosphate cement (CPC) offers significant benefits for the minimally invasive repair of irregular bone defects. However, the main limitations of CPC, including its deficiency in osteogenic properties and insufficient large porosity, require further investigation and resolution. In this study, alginate-chitosan-alginate (ACA) microcapsules were used to encapsulate and deliver rat bone mesenchymal stem cells (rBMSCs) into CPC paste, while a porous CPC scaffold was established to support cell growth. Our results demonstrated that the ACA cell microcapsules effectively protect the cells and facilitate their transport into the CPC paste, thereby enhancing cell viability post-implantation. Additionally, the ACA + CPC extracts were found to stimulate osteogenic differentiation of rBMSCs. Furthermore, results from a rat cranial parietal bone defect model showed that ACA microcapsules containing exogenous rBMSCs initially improved thein situosteogenic potential of CPC within bone defects, providing multiple sites for bone growth. Over time, the osteogenic potential of the exogenous cells diminishes, yet the pores created by the microcapsules persist in supporting ongoing bone formation by recruiting endogenous cells to the osteogenic sites. In conclusion, the utilization of ACA loaded stem cell microcapsules satisfactorily facilitate osteogenesis and degradation of CPC, making it a promising scaffold for bone defect transplantation.

Intrauterine adhesions repair with menstrual blood-derived mesenchymal stem cells via CXCL13-CXCR5 signal axis and its mechanism

BackgroudIntrauterine Adhesions (IUA) is a common gynecological disease which is seriously endangers the reproductive function of women without any ideal treatment. Some researchers found Menstrual Blood-derived Mesenchymal Stem Cells (MenSCs) can repair of damaged endometrium, however, has not been fully clarified. This study aims to evaluate the therapeutic effects of MenSCs in IUA and the repair mechanism in vivo.MethodsThis study is Laboratory-based study. To evaluate the therapeutic effects of MenSCs in IUA, We cultivated MenSCs, established mouse endometrial injury model, observed the uterine morphology and degree of endometrial fibrosis and compared the expression of CXC chemokine ligand-13 (CXCL13)、CXC chemokine receptor-5 (CXCR5)、Plasmin Activating Inhibitor-1(Pai-1), Transforming Growth Faction-β1(TGF- β1) and Matrix Metalloproteinase-9 (Mmp-9) among each groups. GraphPad Prism 8.0 was used for statistical processing. Data were expressed as mean ± SD. Statistical comparisons among groups were performed with one-way ANOVA. P < 0.05 were considered statistically significant.ResultsWe successfully cultured and identified MenSCs and established mice model of uterine adhesion. After treatment with MenSCs, endometrial morphology of mice was partially restored, endometrial thickness was increased, and glands were multipiled. The concentrations of CXCL13 and CXCR5 were significantly increased by immunofluorescence detection compared with the control group. The results of RT-qPCR showed that the expressions of Pai-1 and Mmp-9 were significantly lower than those of the control group.ConclusionsMenSCs may reduce endometrial fibrosis and the down-regulating expression of Pai-1、Mmp-9 and CXCL13-CXCR5 axis were involved in the process of MenSCs repaired IUA.

Extracellular Vesicles Derived from Adipose-Derived Mesenchymal Stem Cells Alleviate Apoptosis and Oxidative Stress of Retinal Pigment Epithelial Cells Through Activation of Nrf2 Signaling Pathway.

Purpose: To examine the potential protective effects of adipose-derived mesenchymal stem cell-derived extracellular vesicles (ASC-EVs) on ARPE-19 cells exposed to hydrogen peroxide (H2O2) stress and to evaluate their ability to delay retinal degeneration in Royal College of Surgeons (RCS) rats. Methods: ARPE-19 cells were pre-treated with ASC-EVs for 24 h, followed by exposure to 200 μM H2O2 for an additional 24 h. RCS rats received an intravitreal injection of phosphate-buffered saline in one eye and ASC-EVs in the other eye. Results: ASC-EV pretreatment significantly protected against H2O2 in the Cell Counting Kit-8 assay and was also effective in the lactate dehydrogenase-release assay. It notably reduced early apoptosis (Annexin V-fluorescein isothiocyanate/propidium iodide assay) and late apoptosis (Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling assay), while significantly decreasing intracellular reactive oxygen species, glutathione levels, and superoxide dismutase activity. NFE2L2, HMOX1, and NQO1 mRNA levels, along with Nrf2, HO-1, and NQO1 protein levels, were significantly elevated with ASC-EV pretreatment. Compared with ARPE-19-derived EVs, 11 miRNAs were upregulated and 34 were downregulated in ASC-EVs. In RCS rats, intravitreal injections of ASC-EVs led to significant preservation of the outer nuclear layer and photoreceptor segments, along with increased nuclear Nrf2 expression and elevated HO-1 and NQO1 levels in the inner retina. Eyes that received intravitreal injections of ASC-EVs demonstrated significantly preserved electroretinography a- and b-wave amplitudes at 1 week post-injection, though this effect faded by 2 weeks. Conclusions: ASC-EVs mitigated apoptosis and oxidative stress in ARPE-19 cells subjected to H2O2 exposure and temporarily slowed retinal degeneration in RCS rats via Nrf2 pathway activation by miRNAs.

Autologous Micrografts Containing Nanovesicles, Exosomes, and Follicle Stem Cells in Androgenetic Alopecia: In Vitro and In Vivo Analysis Through a Multicentric, Observational, Evaluator-Blinded Study.

The use of micrografts (MCGs) containing human follicle mesenchymal stem cells (HF-MSCs) is a hair loss (HL) treatment that needs to be standardized as seems to have promising effects on hair regrowth (HR-G) also thanks to the presence of extracellular vesicles (EVs). The study aims to report both the in vivo results, obtained in patients affected by androgenic alopecia (AGA) treated using MCGs, and in vitro analysis characterizing the EVs. A multicentric, retrospective, observational, evaluator-blinded study was conducted. Eighty-three AGA patients were initially enrolled [52 suffering from male pattern hair loss (MPHL) at stages I-III vertex by the Norwood-Hamilton scale and 31 suffering from female PHL (FPHL) at stages I-II by the Ludwig scale]. Sixty patients (20 females and 40 males) were treated and analyzed after exclusion and inclusion criteria assessment. The in vivo HR-G was evaluated through photography, physician's, and patient's global assessment scales, in addition to standardized photo-trichograms, during a follow-up for 1 year, while the in vitro analysis was performed through a quantitative, morphological, and dimensional characterization of the EVs population using transmission electron microscopy (TEM) and fluorescent microscopy. A hair density (HD) increase of 28 ± 4hairs/cm2 at T4 after 12 months in the targeted area (TA) of FPHL, compared with the baseline, was observed using computerized trichograms with a statistically significant difference (SSD) in hair regrowth (HR-G) (p = 0.0429). Regarding MPHL, an HD increase of 30 ± 5hairs/cm2 at T4 after 12 months in the TA was observed with an SSD in HR-G (p = 0.0012). The presence of EVs and their interaction with the surrounding cellular population were demonstrated. MCGs containing HF-MSCs and exosomes may fill in as a safe and viable alternative treatment against HL in mild and moderate degrees of AGA both in MPHL and in FPHL. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Potential of Cranberry to Stimulate Osteogenesis: An In Vitro Study

This study investigated the potential of Cranberry extract to stimulate osteogenesis in vitro. The total phenolic and monomeric anthocyanin contents in the Cranberry were determined. Liquid chromatography coupled with mass spectrometry was used to identify the Cranberry’s constituents. To assess the Cranberry’s cytotoxicity, a thiazolyl blue tetrazolium bromide assay was employed. Concerning the osteogenesis potential of Cranberry, alkaline phosphatase (ALP) activity, bone morphogenetic protein 2 (BMP-2) expression, and extracellular matrix mineralization were evaluated. The total phenolic content was 522.72 ± 9.80 mg GAE g-1 ES and 364.95 ± 12.49 mg GAE/g detected by the Fast Blue BB and Folin–Ciocalteu method, respectively. For monomeric anthocyanin, the content was 460 ± 30 mg ECG g-1 ES. Moreover, Cranberry concentrations ranged from 62.5 to 500 mg/mL and were found to be biocompatible with osteoblasts and mesenchymal stromal cells. Regarding osteogenesis, 20 mg/mL of Cranberry promoted 2-fold more ALP activity and almost 1.5-fold more BMP-2 than compared to the positive control group. Additionally, 200 mg/mL of Cranberry stimulated a 1.7-fold increase in extracellular matrix mineralization compared to the positive control group. In conclusion, Cranberry displayed potential in stimulating early and late markers of osteogenesis. Its ability to promote osteogenesis and its biocompatibility at higher concentrations hold promise for future application into biomaterials for bone regeneration.

Safety and Potential Efficacy of Expanded Umbilical Cord-Derived Mesenchymal Stromal Cells in Luminal Ulcerative Colitis Patients.

Inflammatory bowel disease (IBD) is characterized by periods of flare-ups and remission. It is likely to be an autoimmune in origin, presenting persistent therapeutic challenges despite current therapies. This study aims to investigate the potential of umbilical cord mesenchymal stromal cells (UCMSCs) in treating ulcerative colitis (UC). This study is a prospective phase 1 pilot, open-label, single-arm, and single-center study. UCMSCs were cultured under current Good Manufacturing Practice (cGMP) conditions and intravenously administered to six patients with UC. Safety and efficacy were evaluated using the Mayo Score/Disease Activity Index. Among the six enrolled adult patients, five completed long-term follow-ups. All exhibited at diagnosis active UC confirmed through comprehensive assessment methods. Each patient received three injections intravenously 2 weeks apart with a dose of 100 million UCMSC each. No significant short-term or intermediate-term adverse events were detected post-UCMSC administration. Long-term follow-up at 12 and 24 months showed sustained safety and no adverse events. Notably, three out of five patients achieved a Mayo score of 0 for UC, maintained at both 12 and 24 months, indicating a highly significant response (P < 0.001). This study demonstrates the safety and potential efficacy of UCMSCs in active UC. However, larger trials are warranted to validate these preliminary findings and to establish the role of UCMSC therapy as an option for managing UC.

Adipose-derived mesenchymal stem cells inhibit hepatic stellate cells activation to alleviate liver fibrosis via Hippo pathway

BackgroundLiver fibrosis is a common pathological process of chronic liver disease, characterized by excessive deposition of extracellular matrix (ECM). Mesenchymal stem cells (MSCs) have been found to have potential therapy effect on liver fibrosis, but the mechanism involved was still unclear. The objective of this study is to investigate the therapeutic efficacy of adipose-derived mesenchymal stem cells (ADMSCs) on the treatment of liver fibrosis, with particular emphasis on elucidating the underlying mechanism of action through which ADMSCs inhibit the activation of hepatic stellate cells (HSCs).MethodsADMSCs were isolated from adipose tissue and injected intravenously into hepatic fibrosis model of rats. The histopathological changes, liver function, collagen deposition, the expression of fibroin and Hippo pathway were evaluated. In vitro, ADMSCs were co-cultured with HSCs activated by transforming growth factor beta 1 (TGF-β1), and the inhibitor of Hippo pathway was used to evaluate the therapeutic mechanism of ADMSCs transplantation.ResultsThe results showed that after the transplantation of ADMSCs, the liver function of rats was improved, the degree of liver fibrosis and collagen deposition were reduced, and the Hippo signaling pathway was activated. In vitro, ADMSCs can effectively inhibit the proliferation and activation of HSCs induced by TGF-β1 treatment. However, the inhibitory effect of ADMSCs was weakened after blocking the Hippo signaling pathway.ConclusionsADMSCs inhibit HSCs activation by regulating YAP/TAZ, thereby promoting functional recovery after liver fibrosis. These findings lay a foundation for further investigation into the precise mechanism by which ADMSCs alleviate liver fibrosis.

Mesenchymal Stem Cells Engineered by Multicomponent Coassembled DNA Nanofibers for Enhanced Wound Healing.

A major challenge for stem cell therapies, such as using mesenchymal stem cells to treat skin injuries, is the stable engraftment of exogenous cells and the maintenance of their regenerative capacities in the wound areas. DNA-based self-assembly strategies can be used for artificial and multifunctional cell surface engineering to stabilize and enhance their functions for therapeutic applications. Here, we developed DNA nanofiber-decorated stem cells, in which DNA-based, multivalent fiber-like structures were self-assembled in situ on the cell surfaces. These engineered stem cells have demonstrated robust reactive oxygen species (ROS) scavenging effects, specific adhesion to damaged vascular endothelial cells, and the ability to enhance angiogenesis, which were effective and safe for acute or chronic wound healing in a mouse model with excisional skin injury. This DNA nanostructure-engineered stem cell provides a novel therapeutic platform for the treatment of tissue damage.

Advancements in Research on Mesenchymal Stem-Cell-Derived Exosomal miRNAs: A Pivotal Insight into Aging and Age-Related Diseases

Mesenchymal stem cells (MSCs) are capable of differentiating into various cell types and play a crucial role in repairing aging tissues and diseased organs. Aging manifests as a gradual loss of cellular, tissue, and organ function, leading to the progression of pathologies. Exosomes (Exos) are extracellular vesicles secreted by cells, which maintain cellular homeostasis, clear cellular debris, and facilitate communication between cells and organs. This review provides a comprehensive summary of the mechanisms for the synthesis and sorting of MSC–Exo miRNAs and summarizes the current research status of MSCs–Exos in mitigating aging and age-related diseases. It delves into the underlying molecular mechanisms, which encompass antioxidative stress, anti-inflammatory response, and the promotion of angiogenesis. Additionally, this review also discusses potential challenges in and future strategies for advancing MSC–Exo miRNA-based therapies in the treatment of aging and age-related diseases.

Cell Population-resolved Multi-Omics Atlas of the Developing Lung.

The lung is a vital organ that undergoes extensive morphological and functional changes during postnatal development. To disambiguate how different cell populations contribute to organ development, we performed proteomic and transcriptomic analyses of four sorted cell populations from the lung of human subjects aged 0 to 8 years-old with a focus on early life. The cell populations analyzed included epithelial, endothelial, mesenchymal, and immune cells. Our results revealed distinct molecular signatures for each of the sorted cell populations that enable the description of molecular shifts occurring in these populations during post-natal development. We confirmed that the proteome of the different cell populations was distinct regardless of age and identified functions specific to each population. We identified a series of cell population protein markers, including those located at the cell surface, that show differential expression and distribution on RNA in situ hybridization and immunofluorescence imaging. We validated the spatial distribution of AT1 and endothelial cell surface markers. Temporal analyses of the proteomes of the four populations revealed processes modulated during postnatal development and clarified the findings obtained from whole tissue proteome studies. Finally, the proteome was compared to a transcriptomics survey performed on the same lung samples to evaluate processes under post-transcriptional control.

Retraction Note: Therapeutic potential of non-adherent BM-derived mesenchymal stem cells in tissue regeneration.

Retraction Note: Therapeutic potential of non-adherent BM-derived mesenchymal stem cells in tissue regeneration.

The effect of conditioned medium isolated from dental pulp mesenchymal stem cells (DPSC) treated with curcumin on oral pathogens

The effect of conditioned medium isolated from dental pulp mesenchymal stem cells (DPSC) treated with curcumin on oral pathogens

Electrospinning Aligned SF/Magnetic Nanoparticles-Blend Nanofiber Scaffolds for Inducing Skeletal Myoblast Alignment and Differentiation.

In the realm of skeletal muscle tissue engineering, anisotropic materials that emulate natural tissues show substantial promise. Electrospun scaffolds, mimicking the fibrillar structure of the extracellular matrix, are commonly employed but often fall short in achieving optimal alignment and mechanical strength. Silk fibroin has emerged as a versatile material in tissue engineering, valued for its biocompatibility, mechanical robustness, and biodegradability. However, conventional electrospinning methods of SF result in randomly oriented fibers, limiting their efficacy. In this work, we developed a straightforward method to fabricate directional tissue scaffolds using silk fibroin. By integrating a magnetic field collecting device and incorporating Fe3O4 nanoparticles into the spinning solution, we successfully produced well-aligned silk nanofiber scaffolds. These aligned fibers not only improved scaffold orientation and mechanical properties but also exhibited magnetic responsiveness. The aligned SF scaffolds effectively guided the adhesion, proliferation, and differentiation of mesenchymal stem cells along the fiber direction. Cultured on these scaffolds, myoblast C2C12 cells demonstrated oriented growth, highlighting the potential of aligned SF fibers in advancing skeletal muscle engineering for biomedical applications.

An innovative 4D printing approach for fabrication of anisotropic collagen scaffolds

Collagen anisotropy is known to provide the essential topographical cues to guide tissue-specific cell function. Recent work has shown that extrusion-based printing using collagenous inks yield 3D scaffolds with high geometric precision and print fidelity. However, these scaffolds lack collagen anisotropy. In this study, extrusion-based 3D printing was combined with a magnetic alignment approach in an innovative 4D printing scheme to generate 3D collagen scaffolds with high degree of collagen anisotropy. Specifically, the 4D printing process parameters-collagen (Col):xanthan gum (XG) ratio (Col:XG; 1:1, 4:1, 9:1 v/v), streptavidin-coated magnetic particle concentration (SMP; 0, 0.2, 0.4 mg ml-1), and print flow speed (2, 3 mm s-1)-were modulated and the effects of these parameters on rheological properties, print fidelity, and collagen alignment were assessed. Further, the effects of collagen anisotropy on human mesenchymal stem cell (hMSC) morphology, orientation, metabolic activity, and ligamentous differentiation were investigated. Results showed that increasing the XG composition (Col:XG 1:1) enhanced ink viscosity and yielded scaffolds with good print fidelity but poor collagen alignment. On the other hand, use of inks with lower XG composition (Col:XG 4:1 and 9:1) together with 0.4 mg ml-1SMP concentration yielded scaffolds with high degree of collagen alignment albeit with suboptimal print fidelity. Modulating the print flow speed conditions (2 mm s-1) with 4:1 Col:XG inks and 0.4 mg ml-1SMP resulted in improved print fidelity of the collagen scaffolds while retaining high level of collagen anisotropy. Cell studies revealed hMSCs orient uniformly on aligned collagen scaffolds. More importantly, collagen anisotropy was found to trigger tendon or ligament-like differentiation of hMSCs. Together, these results suggest that 4D printing is a viable strategy to generate anisotropic collagen scaffolds with significant potential for use in tendon and ligament tissue engineering applications.

Retraction: Transplantation of copper-doped calcium polyphosphate scaffolds combined with copper (II) preconditioned bone marrow mesenchymal stem cells for bone defect repair.

Retraction: Transplantation of copper-doped calcium polyphosphate scaffolds combined with copper (II) preconditioned bone marrow mesenchymal stem cells for bone defect repair.

Intracavernosal mesenchymal stem cell therapy in ischaemic priapism: an experimental study.

The most common form of priapism is ischaemic and its prevalence in men has increased in recent years as a result of intracavernosal drug use. Currently, there is no approved specific treatment for ischaemic priapism other than cavernosal aspiration, which can only provide detumescence. This study aims to evaluate the efficacy of intracavernosal mesenchymal stem cell (MSC) therapy in an ischaemic priapism model. Thirty male Wistar albino rats were divided into three groups: sham (n = 6), priapism (n = 12) and priapism + MSC treatment (n = 12). The experimental groups were also divided into 1 and 12h subgroups of ischaemic priapism. The experimental model was created using a vacuum erection device and constrictive tape technique, and intracavernosal MSC were applied immediately after the tape was removed. After 4weeks, intracavernosal pressures (ICPs) and systemic mean arterial pressure (MAP) were measured. Penectomy was then performed to assess histopathological and molecular changes in the rats' penile tissues. In the ischaemic priapism model, MSC therapy showed significant improvements in peak and mean ICPs and mean ICP/MAP ratio. Histopathological analysis showed significant increases in smooth-muscle/collagen ratio and e-NOS and n-NOS expression. Although there was a decrease in fibrosis, it was not significant. At the molecular level, there were significant decreases in TGF-beta and VEGF mRNA expression, whilst NGF and BDNF mRNA-expression levels showed significant increases with MSC therapy. In terms of ICPs, the therapy showed more significant improvements in short-term priapism. However, when looking at histopathological and molecular parameters, the therapy had positive effects on a wider range of parameters in the long-term priapism. MSC treatment improved cavernosal physiology and had positive effects at the histopathological and molecular level in the ischaemic priapism model.

Transplantation of human umbilical cord-derived mesenchymal stem cells improves age-related ovarian functional decline via regulating the local renin–angiotensin system on inflammation and oxidative stress

BackgroundAge-related reproductive aging is a natural and irreversible physiological process, and delaying childbearing is increasingly common all over the world. Transplantation of mesenchymal stem cells (MSCs) is considered a new and effective therapy to restore ovarian function, but the relevant mechanisms remain unclear. Recently, it has been found that there is a local Renin–angiotensin system (RAS) in human ovary and it plays a key role.MethodsAfter collecting follicular fluid from women who received oocyte retrieval for pure male factor infertility, the level of RAS components in it were detected, and the correlation analysis by linear regression. Then, the in vivo experiments on female C57BL/6 mice were designed to measure ovarian function, and the transcription and translation levels of RAS pathway were detected by molecular biology methods. Moreover, the role of RAS in regulating inflammation and oxidative stress in the co-culture system were explored in in vitro experiments on KGN cells.ResultsFirst, a total of 139 samples of analyzable follicular fluid were obtained. The local RAS of ovary, which is independent of systemic RAS (P > 0.05), is affected by age (Pearson r < 0, P < 0.05) and related to ovarian function, inflammation, oxidative stress indexes and assisted reproduction laboratory outcomes (P < 0.05). Next, the ovary/body weight of aging mice decreased significantly and serum sex hormones levels changed significantly (P < 0.01). The number of functional follicles decreased, while the atresia follicles increased (P < 0.05). After MSCs transplantation, all the above measures have been partially recovered (P < 0.05). Although several RAS components in aging ovary changed, MSCs only improved the expression level of AT1R (P < 0.05). Furthermore, the secretion ability and mitochondrial membrane potential of aging KGN cells decreased, while the intracellular ROS level and the aging cells ratio increased (P < 0.01). All the above measures have been partially recovered when co-cultured with MSCs (P < 0.05). After Ang(1–7) were added into the co-culture system, the above have been more significantly restored compared with Ang II (P < 0.05). Nevertheless, there was no statistical difference in estradiol level no matter which one was added (P > 0.05).ConclusionsTogether, our findings indicate that a novel possible mechanism to explain how stem cells restore age-related ovarian functional decline.

L-arginine, aminoguanidine and mesenchymal stem cells reduce the level of endoplasmic reticulum stress markers and D-dimer in the lungs of mice with antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by damage to the intima of the microcirculatory blood vessels as a result of the formation of autoimmune antibodies to phospholipids of cell membranes. Recent data indicate a possible link between the occurrence of autoimmune diseases and endoplasmic reticulum stress, impaired nitric oxide availability, high plasma D-dimer level. The aim of the study was to estimate the effect of nitric oxide synthesis modulators L-arginine and aminoguanidine, and mesenchymal stem cells on the level of inositol-requiring enzyme-1a (IRE-1a), glucose-regulated protein 78 (GRP-78) as ER stress markers, and the level of D-dimer in the lung tissue of female BALB/c line mice with experimental APS induced with cardiolipin administration. 30 experimental animals were divided into five groups: 1 – control animals; 2 – mice with APS; 3 – mice with APS, injected intraperitoneally with L-arginine hydrochloride (25 mg/kg) and aminoguanidine (10 mg/kg); 4 – mice with APS, injected intraperitoneally with stem cells (5×106/kg); 5 – mice with APS, injected with L-arginine hydrochloride, aminoguanidine and stem cells in combination. After 10 days post APS formation animals were removed from the experiment, proteins were extracted from the lung tissue and their level was determined with Western blotting. It was established that in group with APS the levels of IRE-1, GRP-78 and D-dimer were substantially increased as compared to the control group. After separate administration of both arginine with aminoguanidine and MSC, as well as with their combined use, the level of IRE-1, GRP-78 and D-dimer decreased compared to the indices in animals with induced APS. The obtained data indicated that this effect is probably due to the reduction of ER stress through iNOS inhibition and the anti-inflammatory action of MSCs. Keywords: aminoguanidine, antiphospholipid syndrome, D-dimer, endoplasmic reticulume stress, GRP-78, IRE-1, L-arginine, lung, mesenchymal stem cells

Astragaloside promotes the secretion of MSC-derived exosomal miR-146a-5p by regulating TRAF6/NF-κB pathway to attenuate inflammation in high glucose-impaired endothelial cells.

This study aimed to explore the potential of using mesenchymal stem cell (MSC)-derived exosomes (MSC-Exos) pre-treated with Astragaloside IV (ASIV) to alleviate inflammation in high glucose (HG)-damaged endothelial cells. MSC-Exos were isolated from untreated MSCs and ASIV-pre-treated MSCs, and their characteristics were assessed. The expression of miR-146a-5p in MSC-Exos was determined, and it was found that ASIV treatment enhanced its expression. In order to assess the impact of highly miR-146a-5p-expressing MSC-Exos on HG-injured endothelial cells, we established a model of HG-induced inflammation using human umbilical vein endothelial cells (HUVECs). The study measured cell viability, apoptosis, tube formation, and levels of inflammatory cytokines among the different treatment groups. It was found that transferring MSC-Exos with high miR-146a-5p expression to HG-damaged HUVECs increased cell viability and tube formation ability while reducing the number of apoptotic cells. Additionally, changes in inflammatory factors indicated a reduction in the inflammatory response. Further investigation demonstrated that miR-146a-5p inhibited the expression of TNF receptor associated factor 6 (TRAF6) and phosphorylated NF-κB, which are involved in the inflammatory response. This resulted in the alleviation of inflammation in HG-damaged endothelial cells. In summary, our findings indicate that ASIV treatment stimulated the secretion of MSC-Exos that exhibited increased levels of miR-146a-5p. These exosomes, in turn, regulated the TRAF6/NF-κB pathway. As a result of this modulation, the inflammatory response in HG-damaged endothelial cells was alleviated. These findings offer a fresh approach to addressing vascular complications associated with diabetes, which could lead to novel treatment strategies in the field.