Search

Treatment of articular cartilage remains a great challenge due to its limited self-repair capability. In tissue engineering, a scaffold with both mechanical strength and regenerative capacity has been highly desired. This study developed a double-network scaffold based on natural biomaterials of silk fibroin (SF) and methacrylated hyaluronic acid (MAHA) using three-dimensional (3D) printing technology. Structural and mechanical characteristics of the scaffold was first investigated. To enhance its ability of recruiting endogenous bone marrow mesenchymal stem cells (BMSCs), the scaffold was conjugated with a proven BMSC-specific-affinity peptide E7, and its biocompatibility and capacity of cell recruitment were assessed in vitro. Animal experiments were conducted to evaluate cartilage regeneration after transplantation of the described scaffolds. The SF/HA scaffolds exhibited a hierarchical macro-microporous structure with ideal mechanical properties, and offered a 3D spatial microenvironment for cell migration and proliferation. In vitro experiments demonstrated excellent biocompatibility of the scaffolds to support BMSCs proliferation, differentiation, and extracellular matrix production. In vivo, superior capacity of cartilage regeneration was displayed by the SF/MAHA + E7 scaffold as compared with microfracture and unconjugated SF/MAHA scaffold based on macroscopic, histologic and imaging evaluation. In conclusion, this structurally and functionally optimized SF/MAHA + E7 scaffold may provide a promising approach to repair articular cartilage lesions in situ. [ABSTRACT FROM AUTHOR]

Diabetic osteoporosis (DO) presents significant clinical challenges. This study aimed to investigate the potential of magnetic nanoparticle-enhanced extracellular vesicles (GMNPE-EVs) derived from bone marrow mesenchymal stem cells (BMSCs) to deliver miR-15b-5p, thereby targeting and downregulating glial fibrillary acidic protein (GFAP) expression in rat DO models. Data was sourced from DO-related RNA-seq datasets combined with GEO and GeneCards databases. Rat primary BMSCs, bone marrow-derived macrophages (BMMs), and osteoclasts were isolated and cultured. EVs were separated, and GMNPE targeting EVs were synthesized. Bioinformatic analysis revealed a high GFAP expression in DO-related RNA-seq and GSE26168 datasets for disease models. Experimental results confirmed elevated GFAP in rat DO bone tissues, promoting osteoclast differentiation. miR-15b-5p was identified as a GFAP inhibitor, but was significantly downregulated in DO and enriched in BMSC-derived EVs. In vitro experiments showed that GMNPE-EVs could transfer miR-15b-5p to osteoclasts, downregulating GFAP and inhibiting osteoclast differentiation. In vivo tests confirmed the therapeutic potential of this approach in alleviating rat DO. Collectively, GMNPE-EVs can effectively deliver miR-15b-5p to osteoclasts, downregulating GFAP expression, and hence, offering a therapeutic strategy for rat DO. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cell (MSC)-derived exosomes are considered as alternative to cell therapy in various diseases. This study aimed to understand the effect of bone marrow MSC-derived exosomes (BMMSC-exos) on spinal cord injury (SCI) and to unveil its regulatory mechanism on ferroptosis. Exosomes were isolated from BMMSCs and the uptake of BMMSCs-exos by PC12 cells was determined using PKH67 staining. The effect of BMMSC-exos on SCI in rats was studied by evaluating pathological changes of spinal cord tissues, inflammatory cytokines, and ferroptosis-related proteins. Transcriptome sequencing was used to discover the differential expressed genes (DEGs) between SCI rats and BMMSC-exos-treated rats followed by functional enrichment analyses. The effect of BMMSC-exos on ferroptosis and interleukin 17 (IL-17) pathway was evaluated in SCI rats and oxygen–glucose deprivation (OGD)-treated PC12 cells. The results showed that particles extracted from BMMSCs were exosomes that could be taken up by PC12 cells. BMMSC-exos treatment ameliorated injuries of spinal cord, suppressed the accumulation of Fe2+, malondialdehyde (MDA), and reactive oxygen species (ROS), with the elevated glutathione (GSH). Also, BMMSC-exos downregulated the expression of acyl-CoA synthetase long chain family member 4 (ACSL4) and upregulated glutathione peroxidase 4 (GPX4) and cysteine/glutamate antiporter xCT. A total of 110 DEGs were discovered and they were mainly enriched in IL-17 signaling pathway. Further in vitro and in vivo experiments showed that BMMSC-exos inactivated IL-17 pathway. BMMSC-exos promote the recovery of SCI and inhibit ferroptosis by inhibiting the IL-17 pathway, which provides BMMSC-exos as an alternative to the management of SCI. [ABSTRACT FROM AUTHOR]

IntroductionOsteosarcoma is the most common primary bone tumor. Patients require chemotherapy drugs with high-targeting ability and low off-target toxicity to improve their survival. Exosomes are biological vesicles that mediate long-distance communication between cells and naturally target their source sites. Exosomes derived from bone marrow mesenchymal stem cells (BMSCs) naturally target bone tumor sites, suggesting their potential as effective anti-tumor therapy vectors. In this study, we evaluated the potential of BMSC-derived exosomes in targeting osteosarcoma and serving as a carrier for doxorubicin (DOX).MethodsWe isolated exosomes from human BMSCs and synthesized hybrid exosomes (HEs) by fusing these exosomes with liposomes. These HEs were loaded with DOX to produce a novel drug, HE/DOX.ResultsWe confirmed the successful synthesis of HE/DOX using fluorescence spectroscopy and estimated its size to be 151.1 ± 10.2 nm. HEs expressed the known exosomal proteins ALIX, CD63, and TSG101. Under acidic conditions similar to those observed in the tumor microenvironment, the drug release from HE/DOX was enhanced. In osteosarcoma cell lines and in a mouse osteosarcoma model, HE/DOX exhibited stronger tumor-inhibitory effects than free DOX.ConclusionsOur study demonstrates that BMSC-derived exosomes could effectively target osteosarcoma. Furthermore, HEs can serve as effective carriers of DOX, enabling the treatment of osteosarcoma. These findings highlight a promising direction for tumor-targeted therapy.

Abstract Background Exosomes (Exos) are involved in the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) on heart failure (HF). We investigated the molecular mechanisms underlying the involvement of BMSC-Exos in ferroptosis on HF. Methods A rat model of HF and cellular model of hypoxia were established. BMSC-Exos were injected into model rats or co-cultured with model cells. In model rats, the cardiac function (echocardiography), oxidative stress (commercial kits), pathological damage (HE staining), fibrosis (MASSON staining), iron deposition (Prussian blue staining), and cell apoptosis (TUNEL staining) were examined. Viability (cell counting kit-8; CCK-8), cell cycle (flow cytometry), oxidative stress, and Fe2+ levels were detected in the model cells. GAS5, UL3, YAP, and TAZ expression were detected using qRT-PCR, western blotting, and immunohistochemistry analyses. Results BMSC-Exos restored cardiac function and inhibited oxidative stress, apoptosis, pathological damage, fibrosis, and iron deposition in myocardial tissues of HF rats. In hypoxic cells, BMSC-Exos increased cell viability, decreased the number of G1 phase cells, decreased Fe2+ levels, and inhibited oxidative stress. Ferrostatin-1 (a ferroptosis inhibitor) exhibited a synergistic effect with BMSC-Exos. Additionally, GAS5 was upregulated in BMSC-Exos, further upregulating its target UL3 and Hippo pathway effectors (YAP and TAZ). The relieving effects of BMSC-Exos on HF or hypoxia-induced injury were enhanced by GAS5 overexpression, but weakened by UL3 silencing or verteporfin (a YAP inhibitor). Conclusions GAS5-harbouring BMSC-Exos inhibited ferroptosis by regulating the UL3/Hippo pathway, contributing to HF remission in vivo and in vitro.

Abstract Background A triplet chemotherapy regimen of docetaxel, cisplatin, and 5-fluorouracil (TPF) is used to treat head and neck squamous cell carcinoma; however, it is toxic to bone marrow mesenchymal stem cells (BMSCs). We previously demonstrated that Ganoderma spore lipid (GSL) protect BMSCs against cyclophosphamide toxicity. In this study, we investigated the protective effects of GSL against TPF-induced BMSCs and hematopoietic damage. Methods BMSCs and C57BL/6 mice were divided into control, TPF, co-treatment (simultaneously treated with GSL and TPF for 2 days), and pre-treatment (treated with GSL for 7 days before 2 days of TPF treatment) groups. In vitro, morphology, phenotype, proliferation, senescence, apoptosis, reactive oxygen species (ROS), and differentiation of BMSCs were evaluated. In vivo, peripheral platelets (PLTs) and white blood cells (WBCs) from mouse venous blood were quantified. Bone marrow cells were isolated for hematopoietic colony-forming examination. Results In vitro, GSL significantly alleviated TPF-induced damage to BMSCs compared with the TPF group, recovering their morphology, phenotype, proliferation, and differentiation capacity (p

Background: Exosomes (Exos) are involved in the therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) on heart failure (HF). We investigated the molecular mechanisms underlying the involvement of BMSC-Exos in ferroptosis on HF. Methods: A rat model of HF and cellular model of hypoxia were established. BMSC-Exos were injected into model rats or co-cultured with model cells. In model rats, the cardiac function (echocardiography), oxidative stress (commercial kits), pathological damage (HE staining), fibrosis (MASSON staining), iron deposition (Prussian blue staining), and cell apoptosis (TUNEL staining) were examined. Viability (cell counting kit-8; CCK-8), cell cycle (flow cytometry), oxidative stress, and Fe2+ levels were detected in the model cells. GAS5, UL3, YAP, and TAZ expression were detected using qRT-PCR, western blotting, and immunohistochemistry analyses. Results: BMSC-Exos restored cardiac function and inhibited oxidative stress, apoptosis, pathological damage, fibrosis, and iron deposition in myocardial tissues of HF rats. In hypoxic cells, BMSC-Exos increased cell viability, decreased the number of G1 phase cells, decreased Fe2+ levels, and inhibited oxidative stress. Ferrostatin-1 (a ferroptosis inhibitor) exhibited a synergistic effect with BMSC-Exos. Additionally, GAS5 was upregulated in BMSC-Exos, further upregulating its target UL3 and Hippo pathway effectors (YAP and TAZ). The relieving effects of BMSC-Exos on HF or hypoxia-induced injury were enhanced by GAS5 overexpression, but weakened by UL3 silencing or verteporfin (a YAP inhibitor). Conclusions: GAS5-harbouring BMSC-Exos inhibited ferroptosis by regulating the UL3/Hippo pathway, contributing to HF remission in vivo and in vitro. [ABSTRACT FROM AUTHOR]

Alterations to the human organism that are brought about by aging are comprehensive and detrimental. Of these, an imbalance in bone homeostasis is a major outward manifestation of aging. In older adults, the decreased osteogenic activity of bone marrow mesenchymal stem cells and the inhibition of bone marrow mesenchymal stem cell differentiation lead to decreased bone mass, increased risk of fracture, and impaired bone injury healing. In the past decades, numerous studies have reported the epigenetic alterations that occur during aging, such as decreased core histones, altered DNA methylation patterns, and abnormalities in noncoding RNAs, which ultimately lead to genomic abnormalities and affect the expression of downstream signaling osteoporosis treatment and promoter of fracture healing in older adults. The current review summarizes the impact of epigenetic regulation mechanisms on age‐related bone homeostasis imbalance. [ABSTRACT FROM AUTHOR]

Background: A triplet chemotherapy regimen of docetaxel, cisplatin, and 5-fluorouracil (TPF) is used to treat head and neck squamous cell carcinoma; however, it is toxic to bone marrow mesenchymal stem cells (BMSCs). We previously demonstrated that Ganoderma spore lipid (GSL) protect BMSCs against cyclophosphamide toxicity. In this study, we investigated the protective effects of GSL against TPF-induced BMSCs and hematopoietic damage. Methods: BMSCs and C57BL/6 mice were divided into control, TPF, co-treatment (simultaneously treated with GSL and TPF for 2 days), and pre-treatment (treated with GSL for 7 days before 2 days of TPF treatment) groups. In vitro, morphology, phenotype, proliferation, senescence, apoptosis, reactive oxygen species (ROS), and differentiation of BMSCs were evaluated. In vivo, peripheral platelets (PLTs) and white blood cells (WBCs) from mouse venous blood were quantified. Bone marrow cells were isolated for hematopoietic colony-forming examination. Results: In vitro, GSL significantly alleviated TPF-induced damage to BMSCs compared with the TPF group, recovering their morphology, phenotype, proliferation, and differentiation capacity (p < 0.05). Annexin V/PI and senescence-associated β-galactosidase staining showed that GSL inhibited apoptosis and delayed senescence in TPF-treated BMSCs (p < 0.05). GSL downregulated the expression of caspase-3 and reduced ROS formation (p < 0.05). In vivo, GSL restored the number of peripheral PLTs and WBCs and protected the colony-forming capacity of bone marrow cells (p < 0.05). Conclusions: GSL efficiently protected BMSCs from damage caused by TPF and recovered hematopoiesis. [ABSTRACT FROM AUTHOR]

To investigate the ability of sulfonated polyetheretherketone (SPEEK) to promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and compare the effects of different degrees of sulfonation (DS), SPEEK was made with two different DS. The L-SPEEK group had a lower DS, while the H-SPEEK group had a higher DS. The physicochemical properties of both species were evaluated by scanning electron microscopy (SEM), capitilize Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Then, proliferation and osteogenic differentiation between the two groups and with pure polyetheretherketone (PEEK) were compared after surface inoculation of bone marrow mesenchymal stem cells (BMSCs). Scanning electron microscopy (SEM) revealed that the surface of the PEEK substrates could be smooth or coarse, and the degree of roughness increased with increasing sulfonation. FTIR spectroscopy showed that both the L-SPEEK and H-SPEEK samples contained sulfonic acid. TGA and XRD revealed that the components in the two groups were the same, but the intensities were different. After BMSC inoculation, a CCK8 assay revealed that the cells proliferated more on the H-SPEEK surface and little on the L-SPEEK surface compared with the PEEK surface. Then, osteogenic differentiation was verified by immunofluorescence staining for OCN and Runx2, which indicated that H-SPEEK had the greatest effect on improving differentiation. The results of alizarin red staining (ARS) and alkaline phosphatase staining (APS) also revealed this trend. Sulfonation can change the microsurface of PEEK, which can improve both BMSC proliferation and osteogenic differentiation.

With rising society stress, depression-induced osteoporosis is increasing. However, the mechanism involved is unclear. In this study, we explored the effect of plasma exosomal miRNAs on bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation in a chronic unpredictable mild stress (CUMS)-induced depression rat model. After 12 weeks of CUMS-induced depression, the pathological changes in the bone tissue and markers of osteogenic differentiation were tested by micro-computed tomography, hematoxylin-eosin staining, and quantitative real-time reverse transcription PCR (qRT-PCR). Plasma exosomes from rats were isolated and co-incubated with BMSCs for 14 d to detect the effect on osteogenic markers. Next-generation sequencing identified the miRNAs in the plasma exosomes, and the differential miRNAs were analyzed and verified by qRT-PCR. BMSCs were infected with lentivirus to upregulate miRNA-30a-5p and incubated in a medium that induced osteogenic differentiation for 14 d. The effect of miR-30a-5p on osteogenic differentiation was determined by qPCR and alizarin red staining. CUMS-induced depression rat model was established successfully, and exhibited reduced bone mass and damaged bone microstructure compared to that of the controls. The observed pathological changes suggested the occurrence of osteoporosis in the CUMS group, and the mRNA expression of osteogenic markers was also significantly reduced. Incubation of BMSCs with plasma exosomes from the CUMS group for 14 d resulted in a significant decrease in the expression of osteogenic markers. Twenty-five differentially expressed miRNAs in plasma exosomes were identified and upregulation of miR-30a-5p was observed to significantly inhibit the expression of osteogenic markers in BMSCs. Our findings contributed to a comprehensive understanding of the mechanism of osteoporosis caused by depression, and demonstrated the potential of miR-30a-5p as a novel biomarker or therapeutic target for the treatment of osteoporosis.

Abstract Background Osteoarthritis is a chronic disease mainly involving the damage of articular cartilage and the whole articular tissue, which is the main cause of disability in the elderly. To explore more effective treatment measures, this study analyzed the regulatory role and molecular mechanism of lncRNA LINC00665 (LINC00665) in the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), providing a valuable theoretical basis for the pathogenesis and patient treatment of osteoarthritis. Methods Osteoarthritis tissues and healthy tissues were obtained from 52 patients with osteoarthritis and 34 amputated patients without osteoarthritis, and the levels of LINC00665 and miR-214-3p were assessed by RT-qPCR. BMSCs were cultured and induced chondrogenic differentiation. The proliferation ability of BMSCs was detected by CCK-8 method, and the apoptosis level of BMSCs was evaluated by flow cytometry. The content of proteoglycan-glycosaminoglycan (GAG) in cartilage matrix was determined by Alcian blue staining. In addition, the binding relationship between LINC00665 and miR-214-3p was verified by luciferase reporter assay, and the molecular mechanism was further analyzed. Results In osteoarthritis tissues, LINC00665 was elevated and miR-214-3p was down-regulated. With the chondrogenic differentiation of BMSCs, the level of GAG increased, and LINC00665 expression gradually decreased, while miR-214-3p level was on the contrary. After transfection of pcDNA3.1-LINC00665 in BMSCs, cell proliferation capacity was decreased, apoptosis rate was increased, and GAG content was reduced. Moreover, LINC00665 sponged miR-214-3p and negatively regulate its expression. Transfection of pcDNA3.1-LINC00665-miR-214-3p mimic changed the regulation of pcDNA3.1-LINC00665 on the viability and chondrogenic differentiation of BMSCs. Conclusions Overexpression of lncRNA LINC00665 inhibited the proliferation and chondrogenic differentiation of BMSCs by targeting miR-214-3p. The LINC00665/miR-214-3p axis may improve joint damage and alleviate the progression of osteoarthritis.

Introduction: Bones are easily damaged. Biomimetic scaffolds are involved in tissue engineering. This study explored polydopamine (PDA)-coated poly lactic-co-glycolic acid (PLGA)-magnesium oxide (MgO) scaffold properties and its effects on bone marrow mesenchymal stem cells (BMSCs) osteogenic differentiation. Methods: PLGA/MgO scaffolds were prepared by low-temperature 3D printing technology and PDA coatings were prepared by immersion method. Scaffold structure was observed by scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS), fourier transform infrared spectrometer (FTIR). Scaffold hydrophilicity, compressive/elastic modulus, and degradation rates were analyzed by water contact angle measurement, mechanical tests, and simulated-body fluid immersion. Rat BMSCs were cultured in scaffold extract. Cell activity on days 1, 3, and 7 was detected by MTT. Cells were induced by osteogenic differentiation, followed by evaluation of alkaline phosphatase (ALP) activity on days 3, 7, and 14 of induction and Osteocalcin, Osteocalcin, and Collagen I expressions. Results: The prepared PLGA/MgO scaffolds had dense microparticles. With the increase of MgO contents, the hydrophilicity was enhanced, scaffold degradation rate was accelerated, magnesium ion release rate and scaffold extract pH value were increased, and cytotoxicity was less when magnesium mass ratio was less than 10%. Compared with other scaffolds, compressive and elastic modulus of PLGA/MgO (10%) scaffolds were increased; BMSCs incubated with PLGA/MgO (10%) scaffold extract had higher ALP activity and Osteocalcin, Osteopontin, and Collagen I expressions. PDA coating was prepared in PLGA/MgO (10%) scaffolds and the mechanical properties were not affected. PLGA/MgO (10%)/PDA scaffolds had better hydrophilicity and biocompatibility and promoted BMSC osteogenic differentiation. Conclusion: Low-temperature 3D printing PLGA/MgO (10%)/PDA scaffolds had good hydrophilicity and biocompatibility, and were conducive to BMSC osteogenic differentiation.

AbstractContext Wen-Shen-Tong-Luo-Zhi-Tong (WSTLZT) Decoction is a Chinese prescription with antiosteoporosis effects, especially in patients with abnormal lipid metabolism.Objective To explore the effect and mechanism of WSTLZT on osteoporosis (OP) through adipocyte-derived exosomes.Materials and methods Adipocyte-derived exosomes with or without WSTLZT treated were identified by transmission electron microscopy, nanoparticle tracking analysis (NTA) and western blotting (WB). Co-culture experiments for bone marrow mesenchymal stem cells (BMSCs) and exosomes were performed to examine the uptake and effect of exosome in osteogenesis and adipogenic differentiation of BMSC. MicroRNA profiles, luciferase and IP were used for exploring specific mechanisms of exosome on BMSC. In vivo, 80 Balb/c mice were randomly divided into four groups: Sham, Ovx, Exo (30 μg exosomes), Exo-WSTLZT (30 μg WSTLZT-exosomes), tail vein injection every week. After 12 weeks, the bone microstructure and marrow fat distribution were analysed by micro-CT.Results ALP, Alizarin red and Oil red staining showed that WSTLZT-induced exosomes from adipocyte can regulate osteoblastic and adipogenic differentiation of BMSC. MicroRNA profiles observed that WSTLZT treatment resulted in 87 differentially expressed miRNAs (p

Treatment of articular cartilage remains a great challenge due to its limited self-repair capability. In tissue engineering, a scaffold with both mechanical strength and regenerative capacity has been highly desired. This study developed a double-network scaffold based on natural biomaterials of silk fibroin (SF) and methacrylated hyaluronic acid (MAHA) using three-dimensional (3D) printing technology. Structural and mechanical characteristics of the scaffold was first investigated. To enhance its ability of recruiting endogenous bone marrow mesenchymal stem cells (BMSCs), the scaffold was conjugated with a proven BMSC-specific-affinity peptide E7, and its biocompatibility and capacity of cell recruitment were assessed in vitro. Animal experiments were conducted to evaluate cartilage regeneration after transplantation of the described scaffolds. The SF/HA scaffolds exhibited a hierarchical macro-microporous structure with ideal mechanical properties, and offered a 3D spatial microenvironment for cell migration and proliferation. In vitro experiments demonstrated excellent biocompatibility of the scaffolds to support BMSCs proliferation, differentiation, and extracellular matrix production. In vivo, superior capacity of cartilage regeneration was displayed by the SF/MAHA + E7 scaffold as compared with microfracture and unconjugated SF/MAHA scaffold based on macroscopic, histologic and imaging evaluation. In conclusion, this structurally and functionally optimized SF/MAHA + E7 scaffold may provide a promising approach to repair articular cartilage lesions in situ.

Bone mesenchymal stem cell (BMSC)-derived exosome (BMSC-Exo) could be a treatment method for ischemic injury. In ischemic cerebrovascular disease (IC), microglia is pivotal in neuronal damage and remodeling. This study explores the mechanisms of BMSC-Exo miR-148b-3p in regulating oxygen-glucose deprivation/reoxygenation (OGD/R)-induced human microglial clone 3 (HMC3) cell activation. Transmission electron microscopy (TEM) and qNano were used to assess BMSC-Exo features. The functions of BMSC-Exo miR-148 b-3p in OGD/R-induced HMC3 cell activation were explored via MTT assay, flow cytometry, scratch, transwell, and enzyme-linked immunosorbent assay (ELISA) assays. A dual-luciferase reporter assay was performed to determine the relationship between miR-148b-3p and Delta-like ligand 4(DDL4) or neurogenic locus notch homolog protein 1 (Notch1). OGD/R decreased miR-148b-3p expression in HMC3 cells. After BMSC-Exo treatment, miR-148b-3p expression was upregulated, cell viability and migration were inhibited, cell cycles remained in the G0/G1 phase, and proinflammatory cytokines were decreased in OGD/R-induced HMC3 cells. More importantly, BMSC-Exo miR-148b-3p could further strengthen BMSC-Exo effects. DDL4 and Notch1 are direct targets of miR-148b-3p, respectively. Moreover, the knockdown of DLL4 or Notch1 could inhibit OGD/R-induced HMC3 cell activation. BMSC-Exo miR-148b-3p inhibited OGD/R-induced HMC3 cell activation via inhibiting DLL4 and Notch1 expression, which provided a new strategy for treating cerebral ischemia. • BMSCs-derived exosomes inhibit OGD/R-induced HMC3 cell activation. • BMSCs-derived exosomal miR-148b-3p inhibits OGD/R-induced HMC3 cell activation. • DLL4 and Notch1 are direct targets of miR-148b-3p. • Knockdown of DLL4 or Notch1 inhibits OGD/R-induced HMC3 cell activation. • BMSC-derived exosomal miR-148b-3p inhibits OGD/R-induced HMC3 cell activation via inhibiting DLL4 and Notch1 expression. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis is a chronic disease mainly involving the damage of articular cartilage and the whole articular tissue, which is the main cause of disability in the elderly. To explore more effective treatment measures, this study analyzed the regulatory role and molecular mechanism of lncRNA LINC00665 (LINC00665) in the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), providing a valuable theoretical basis for the pathogenesis and patient treatment of osteoarthritis. Methods: Osteoarthritis tissues and healthy tissues were obtained from 52 patients with osteoarthritis and 34 amputated patients without osteoarthritis, and the levels of LINC00665 and miR-214-3p were assessed by RT-qPCR. BMSCs were cultured and induced chondrogenic differentiation. The proliferation ability of BMSCs was detected by CCK-8 method, and the apoptosis level of BMSCs was evaluated by flow cytometry. The content of proteoglycan-glycosaminoglycan (GAG) in cartilage matrix was determined by Alcian blue staining. In addition, the binding relationship between LINC00665 and miR-214-3p was verified by luciferase reporter assay, and the molecular mechanism was further analyzed. Results: In osteoarthritis tissues, LINC00665 was elevated and miR-214-3p was down-regulated. With the chondrogenic differentiation of BMSCs, the level of GAG increased, and LINC00665 expression gradually decreased, while miR-214-3p level was on the contrary. After transfection of pcDNA3.1-LINC00665 in BMSCs, cell proliferation capacity was decreased, apoptosis rate was increased, and GAG content was reduced. Moreover, LINC00665 sponged miR-214-3p and negatively regulate its expression. Transfection of pcDNA3.1-LINC00665-miR-214-3p mimic changed the regulation of pcDNA3.1-LINC00665 on the viability and chondrogenic differentiation of BMSCs. Conclusions: Overexpression of lncRNA LINC00665 inhibited the proliferation and chondrogenic differentiation of BMSCs by targeting miR-214-3p. The LINC00665/miR-214-3p axis may improve joint damage and alleviate the progression of osteoarthritis. [ABSTRACT FROM AUTHOR]

Bone marrow mesenchymal stem cell (BM-MSC)-derived extracellular vesicles (ExoFlo) convey the immunomodulatory and regenerative properties of intact BM-MSCs. This study aimed to determine the safety and efficacy of ExoFlo as treatment for moderate to severe ARDS in patients with severe COVID-19. Do two doses of ExoFlo safely reduce mortality in COVID-19-associated moderate to severe ARDS compared with placebo? A prospective phase 2 multicenter double-anonymized randomized placebo-controlled dosing trial was conducted at five sites across the United States with infusions of placebo, 10 mL of ExoFlo, or 15 mL of ExoFlo on days 1 and 4. Patients (N = 102) with COVID-19-associated moderate to severe ARDS were enrolled and randomized to treatment. Adverse events were documented throughout the study. The primary outcome measure was all-cause 60-day mortality rate. Secondary outcomes included time to death (overall mortality); the incidence of treatment-emergent serious adverse events; proportion of discharged patients at 7, 30, and 60 days; time to hospital discharge; and ventilation-free days. No treatment-related adverse events were reported. Mortality (60-day) in the intention-to-treat population was reduced with 15 mL ExoFlo mixed with 85 mL normal saline (ExoFlo-15) compared with placebo (not significant, χ2, P =.1343). For the post hoc subgroup analyses, 60-day mortality was decreased with ExoFlo-15 compared with placebo (relative risk, 0.385; 95% CI, 0.159-0.931; P =.0340; n = 50). With ExoFlo-15, a relative risk of 0.423 (95% CI, 0.173-1.032; P =.0588; n = 24) was determined for participants aged 18 to 65 years with moderate to severe ARDS. Ventilation-free days improved with ExoFlo-15 (P =.0455; n = 50) for all participants aged 18 to 65 years. The 15 mL dose of ExoFlo was found to be safe in patients with severe or critical COVID-19-associated respiratory failure. In participants aged 18 to 65 years, the risk reduction in 60-day mortality was further improved from subjects of all ages in the intention-to-treat population after two doses of 15 mL of ExoFlo compared with placebo. ClinicalTrials.gov; No.: NCT04493242; URL: www.clinicaltrials.gov. [Display omitted] [ABSTRACT FROM AUTHOR]

Wen-Shen-Tong-Luo-Zhi-Tong (WSTLZT) Decoction is a Chinese prescription with antiosteoporosis effects, especially in patients with abnormal lipid metabolism. To explore the effect and mechanism of WSTLZT on osteoporosis (OP) through adipocyte-derived exosomes. Adipocyte-derived exosomes with or without WSTLZT treated were identified by transmission electron microscopy, nanoparticle tracking analysis (NTA) and western blotting (WB). Co-culture experiments for bone marrow mesenchymal stem cells (BMSCs) and exosomes were performed to examine the uptake and effect of exosome in osteogenesis and adipogenic differentiation of BMSC. MicroRNA profiles, luciferase and IP were used for exploring specific mechanisms of exosome on BMSC. In vivo, 80 Balb/c mice were randomly divided into four groups: Sham, Ovx, Exo (30 μg exosomes), Exo-WSTLZT (30 μg WSTLZT-exosomes), tail vein injection every week. After 12 weeks, the bone microstructure and marrow fat distribution were analysed by micro-CT. ALP, Alizarin red and Oil red staining showed that WSTLZT-induced exosomes from adipocyte can regulate osteoblastic and adipogenic differentiation of BMSC. MicroRNA profiles observed that WSTLZT treatment resulted in 87 differentially expressed miRNAs (p < 0.05). MiR-122-5p with the greatest difference was screened by q-PCR (p < 0.01). The target relationship between miR-122-5p and SPRY2 was tested by luciferase and IP. MiR-122-5p negatively regulated SPRY2 and elevated the activity of MAPK signalling pathway, thereby regulating the osteoblastic and adipogenic differentiation of BMSC. In vivo, exosomes can not only improve bone microarchitecture but also significantly reduce accumulation of bone marrow adipose. WSTLZT can exert anti-OP effect through SPRY2 via the MAKP signalling by miR-122-5p carried by adipocyte-derived exosomes. [ABSTRACT FROM AUTHOR]

Abstract Objective Osteogenesis is the key process of bone homeostasis differentiation. Numerous studies have manifested that circular RNA (circRNA) is a critical regulator of osteogenesis. The research was to explore circRNA-mediated mechanisms in osteogenesis. Methods Bone marrow mesenchymal stem cells (BMSCs) were cultured and induced to osteogenic differentiation (OD). Then, oe-circ-FKBP5, oe-NC, si-circ-FKBP5, si-NC, miR-205-5p mimic, mimic NC, miR-205-5p inhibitor, inhibitor NC, sh-RUNX2, or sh-NC were transfected into BMSCs. Alkaline phosphatase (ALP) activity was detected by ALP staining, cell mineralization was detected by alizarin red staining, cell proliferation was detected by CCK-8, and cell apoptosis was detected by flow cytometry. Then, the expression of circ-FKBP5, miR-205-5p, RUNX2 and osteogenic marker genes was detected by RT-qPCR, and the expression of RUNX2 protein was detected by Western blot. Finally, the targeting relationship between miR-205-5p and circ-FKBP5 or RUNX2 was verified by bioinformation website analysis and dual luciferase reporter gene detection. Results Circ-FK501 binding protein 51 (FKBP5) was distinctly elevated during OD of BMSCs. Elevated circ-FKBP5 boosted the proliferation and OD, as well as expression of osteogenic marker genes while reduced apoptosis of BMSCs. Down-regulation of circ-FKBP5 inhibited BMSCs proliferation, OD and osteogenic marker gene expression, and promoted apoptosis of BMSCs. Subsequently, circ-FKBP5 combined with miR-205-5p and constrained miR-205-5p expression. Silenced miR-205-5p boosted proliferation, OD, and expression of osteogenic marker genes and suppressed apoptosis of BMSCs. However, up-regulation of miR-205-5p inhibited BMSC proliferation, OD and osteogenic marker gene expression, and promoted apoptosis. Additionally, miR-205-5p targeted Runt-associated transcription factor 2 (RUNX2). Repression of RUNX2 turned around the effect of circ-FKBP5 overexpression on BMSCs. Conclusion In brief, circ-FKBP5 boosted BMSC proliferation and OD by mediating the miR-205-5p/RUNX2 axis.

Objective: Osteogenesis is the key process of bone homeostasis differentiation. Numerous studies have manifested that circular RNA (circRNA) is a critical regulator of osteogenesis. The research was to explore circRNA-mediated mechanisms in osteogenesis. Methods: Bone marrow mesenchymal stem cells (BMSCs) were cultured and induced to osteogenic differentiation (OD). Then, oe-circ-FKBP5, oe-NC, si-circ-FKBP5, si-NC, miR-205-5p mimic, mimic NC, miR-205-5p inhibitor, inhibitor NC, sh-RUNX2, or sh-NC were transfected into BMSCs. Alkaline phosphatase (ALP) activity was detected by ALP staining, cell mineralization was detected by alizarin red staining, cell proliferation was detected by CCK-8, and cell apoptosis was detected by flow cytometry. Then, the expression of circ-FKBP5, miR-205-5p, RUNX2 and osteogenic marker genes was detected by RT-qPCR, and the expression of RUNX2 protein was detected by Western blot. Finally, the targeting relationship between miR-205-5p and circ-FKBP5 or RUNX2 was verified by bioinformation website analysis and dual luciferase reporter gene detection. Results: Circ-FK501 binding protein 51 (FKBP5) was distinctly elevated during OD of BMSCs. Elevated circ-FKBP5 boosted the proliferation and OD, as well as expression of osteogenic marker genes while reduced apoptosis of BMSCs. Down-regulation of circ-FKBP5 inhibited BMSCs proliferation, OD and osteogenic marker gene expression, and promoted apoptosis of BMSCs. Subsequently, circ-FKBP5 combined with miR-205-5p and constrained miR-205-5p expression. Silenced miR-205-5p boosted proliferation, OD, and expression of osteogenic marker genes and suppressed apoptosis of BMSCs. However, up-regulation of miR-205-5p inhibited BMSC proliferation, OD and osteogenic marker gene expression, and promoted apoptosis. Additionally, miR-205-5p targeted Runt-associated transcription factor 2 (RUNX2). Repression of RUNX2 turned around the effect of circ-FKBP5 overexpression on BMSCs. Conclusion: In brief, circ-FKBP5 boosted BMSC proliferation and OD by mediating the miR-205-5p/RUNX2 axis. [ABSTRACT FROM AUTHOR]

Objective. This study aimed to explore the effects of bone marrow mesenchymal stem cell (BMSC)-derived exosomal miR-146a-5p on microglial polarization and the potential underlying mechanisms in oxygen-glucose deprivation (OGD)-exposed microglial cells. Methods. Exosomes were isolated from BMSCs, and their characteristics were examined. The effects of BMSC-derived exosomes on microglial polarization were investigated in OGD-exposed BV-2 cells. Differentially expressed miRNAs were identified and their biological function was explored using enrichment analyses. The regulatory role of miR-146a-5p in microglial polarization was studied via flow cytometry. Finally, the downstream target gene Traf6 was validated, and the role of the miR-146a-5p/Traf6 axis in modulating microglial polarization was investigated in OGD-exposed BV-2 cells. Results. BMSC-derived exosomes were successfully isolated and characterized. A total of 10 upregulated and 33 downregulated miRNAs were identified. Exosomal treatment resulted in significant changes in microglial polarization markers. miR-146a-5p was found to be significantly downregulated in OGD-exposed microglial cells treated with exosomes. Manipulation of miR-146a-5p expression modulated microglial polarization. Moreover, the miR-146a-5p/Traf6 axis regulated microglial polarization. Conclusion. Our findings demonstrate that BMSC-derived exosomal via miR-146a-5p modulates microglial polarization by targeting Traf6, providing a potential thermal target for the treatment of neurological diseases involving microglial activation. [ABSTRACT FROM AUTHOR]

Background: The inadequate regeneration of natural tissue (mainly fibrocartilage) between tendon and bone during rotator cuff (RC) repair results in an unsatisfactory quality of RC healing. Cell-free therapy based on stem cell exosomes is a safer and more promising approach for tissue regeneration. Here, we investigated the effect of exosomes from human urine-derived stem cells (USCs) and their subpopulations (CD133+USCs) on RC healing. Methods: USCs were isolated from urine and sorted by flow cytometry to obtain CD133+ urine-derived stem cells (CD133+ USCs). Urine-derived stem cell exosomes (USC-Exos) and CD133+ urine-derived stem cell exosomes (CD133+ USC-Exos) were subsequently isolated from the cell supernatant and identified by transmission electron microscopy (TEM), particle size analysis, and Western blot. We performed in vitro functional assays to evaluate the effects of USC-Exos and CD133+ USC-Exos on human bone marrow mesenchymal stem cells (BMSCs) proliferation, migration, osteogenic differentiation, and chondrogenic differentiation. In vivo experiments were performed by local injection of exosome–hydrogel complexes for the treatment of RC injury. The effects of CD133+ USC-Exos and USC-Exos on RC healing were assessed from imaging, histological, and biomechanical tests. Results: CD133+ USCs were positive for CD29, CD44, CD73, CD90, CD133, but negative for CD34 and CD45. Differentiation ability test results showed that both USCs and CD133+ USCs had the potential for osteogenic, chondrogenic, and adipogenic differentiation, but CD133+ USCs had stronger chondrogenic differentiation ability. CD133+ USC-Exos and USC-Exos could be efficiently taken up by BMSCs and promote their migration, osteogenic and chondrogenic differentiation. However, CD133+ USC-Exos could promote the chondrogenic differentiation of BMSCs more than USC-Exos. Compared with USC-Exos, CD133+ USC-Exos could promote the healing of bone-tendon interface (BTI) more effectively, which might be related to its ability to promote the differentiation of BMSCs into chondroblasts. Although the two exosomes exhibited the same effect in promoting subchondral bone repair in BTI, the CD133+ USC-Exos group had higher histological scores and stronger biomechanical properties. Conclusion: CD133+ USC-Exos hydrogel complex may become a promising therapeutic approach for RC healing based on stem cell exosomes. The translational potential of this article: This is the first study to assess the specific role of CD133+ USC-Exos in RC healing which may be related to the activation of BMSCs by CD133+ USC-Exos towards chondrogenic differentiation. Further, our study provides a reference for possible future treatment of BTI by applying CD133+ USC-Exos hydrogel complex.

Increasing the osteogenic differentiation ability and decreasing the adipogenic differentiation ability of bone marrow mesenchymal stem cells (BMSCs) is a potential strategy for the treatment of osteoporosis (OP). Naturally derived oligosaccharides have shown significant anti-osteoporotic effects. Nystose (NST), an oligosaccharide, was isolated from the roots of Morinda officinalis How. (MO). The aim of the present study was to investigate the effects of NST on bone loss in ovariectomized mice, and explore the underlying mechanism of NST in promoting differentiation of BMSCs to osteoblasts. Administration of NST (40, 80 and 160 mg/kg) and the positive control of estradiol valerate (0.2 mg/kg) for 8 weeks significantly prevented bone loss induced by ovariectomy (OVX), increased the bone mass density (BMD), improved the bone microarchitecture and reduced urine calcium and deoxypyridinoline (DPD) in ovariectomized mice, while inhibited the increase of body weight without significantly affecting the uterus weight. Furthermore, we found that NST increased osteogenic differentiation, inhibited adipogenic differentiation of BMSCs in vitro, and upregulated the expression of the key proteins of BMP and Wnt/β-catenin pathways. In addition, Noggin and Dickkopf-related protein-1 (DKK-1) reversed the effect of NST on osteogenic differentiation and expression of the key proteins in BMP and Wnt/β-catenin pathway. The luciferase activities and the molecular docking analysis further supported the mechanism of NST. In conclusion, these results indicating that NST can be clinically used as a potential alternative medicine for the prevention and treatment of postmenopausal osteoporosis.

Osteoarthritis (OA) is an extremely common type of chronic progressive disease in clinical practice. lncRNA TUC339 has a close association with bone marrow mesenchymal stem cell (BMSC) and an important impact on organismal inflammation. However, the mechanism of BMSC-derived lncRNA TUC339 on OA was poorly understood. In this study, we found that TUC339 was lower in the research group than in the control group and it was negatively correlated with IL-6, IL-8 and TNF-α. Prognosis TUC339 was lower in patients with recurrent OA than in those without recurrence, and ROC analysis manifested that TUC339 had a better predictive value for recurrence of OA. Phenotypic identification revealed elevated expression of CD29 and CD44 in BMSCs and TSG101, CD63 and CD81 in BMSCs-exosome (BMSCs-exo), with a stem cell versus exosome phenotype. Finally, animal experiments improved significantly in joint injury in the BMSCs-exo and TUC339-overexpression vector groups compared with control groups. Similarly, the activity of chondrocytes was enhanced, and apoptosis was reduced in the BMSCs-exo group versus the TUC339-overexpression vector group of rats. Study demonstrated that BMSCs-exo improves OA by elevating the expression of TUC339 to promote M1-type mø to M2-type polarization, suppressing inflammation and promoting chondrocyte activity, which provides a reliable basis for future transplantation therapy of MSCs for OA.

Pneumonia is one of the leading causes of death in patients with acute ischemic stroke (AIS). Antibiotics fail to improve prognosis of patients with post‐stroke pneumonia, albeit suppressing infection, due to adverse impacts on the immune system. The current study reports that bone marrow mesenchymal stem cells (BM‐MSC) downregulate bacterial load in the lungs of stroke mice models. RNA‐sequencing of the lung from BM‐MSC‐treated stroke models indicates that BM‐MSC modulates pulmonary macrophage activities after cerebral ischemia. Mechanistically, BM‐MSC promotes the bacterial phagocytosis of pulmonary macrophages through releasing migrasomes, which are migration‐dependent extracellular vesicles. With liquid chromatography‐tandem mass spectrometry (LC‐MS/MS), the result shows that BM‐MSC are found to load the antibacterial peptide dermcidin (DCD) in migrasomes upon bacterial stimulation. Besides the antibiotic effect, DCD enhances LC3‐associated phagocytosis (LAP) of macrophages, facilitating their bacterial clearance. The data demonstrate that BM‐MSC is a promising therapeutic candidate against post‐stroke pneumonia, with dual functions of anti‐infection and immunol modulation, which is more than a match for antibiotics treatment. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) has been shown to be a clinical risk factor for bone diseases including osteoporosis and fragility. Bone metabolism is a complicated process that requires coordinated differentiation and proliferation of bone marrow mesenchymal stem cells (BMSCs). Owing to the regenerative properties, BMSCs have laid a robust foundation for their clinical application in various diseases. However, mounting evidence indicates that the osteogenic capability of BMSCs is impaired under high glucose conditions, which is responsible for diabetic bone diseases and greatly reduces the therapeutic efficiency of BMSCs. With the rapidly increasing incidence of DM, a better understanding of the impacts of hyperglycemia on BMSCs osteogenesis and the underlying mechanisms is needed. In this review, we aim to summarize the current knowledge of the osteogenesis of BMSCs in hyperglycemia, the underlying mechanisms, and the strategies to rescue the impaired BMSCs osteogenesis. [ABSTRACT FROM AUTHOR]

Background: Disruption of intestinal barrier function and an imbalance in intestinal immunity are crucial for the occurrence and development of ulcerative colitis. Because of their important roles in regulating inflammation and immunity, exosomes (Exos) released from bone marrow mesenchymal stem cells (BMSCs) may be useful for treating ulcerative colitis. The EphB/EphrinB signaling pathway plays a crucial role in the inflammatory process and the development and function of immune cells, and can mediate long-distance intercellular communication through extracellular vesicles. This study was conducted to explore the effects of pre-modified BMSC-Exos expressing EphB2 (EphB2-Exos) on immunoregulation in vitro. Methods: We transfected a lentivirus vector encoding EphB2 into BMSCs and isolated EphB2-Exos from the culture supernatant. Inflammation and oxidative damage in the human colon adenocarcinoma cell line (Caco-2) were induced by dextran sulfate sodium/hydrogen peroxide. In addition, spleen CD4+ T lymphocytes of rats were sorted in vitro. We conducted a series of experiments to explore the biological functions of EphB2-Exos. Results: EphB2-Exos were successfully isolated and were found to significantly protect the activity, proliferation, and migration of Caco-2 cells that were inhibited by dextran sulfate sodium. EphB2-Exos alleviated inflammation and apoptosis and increased the activity of antioxidant enzymes while inhibiting oxidative stress in Caco-2 cells. EphB2-Exos restored intestinal barrier function by inhibiting the RhoA/ROCK pathway and regulated the polarization of CD4+T cells. Conclusion: EphB2-Exos enhanced intestinal barrier function and regulated the immune balance by inhibiting the RhoA/ROCK pathway in vitro. These findings suggest that EphB2-Exos can be applied as a cell-free therapy for ulcerative colitis. [ABSTRACT FROM AUTHOR]

Although many therapeutic interventions have shown promise in treating spinal cord injury, focusing on a single aspect of repair cannot achieve successful and functional regeneration in patients following spinal cord injury . In this study, we applied a combinatorial approach for treating spinal cord injury involving neuroprotection and rehabilitation, exploiting cell transplantation and functional sensorimotor training to promote nerve regeneration and functional recovery. Here, we used a mouse model of thoracic contusive spinal cord injury to investigate whether the combination of bone marrow mesenchymal stem cell transplantation and exercise training has a synergistic effect on functional restoration. Locomotor function was evaluated by the Basso Mouse Scale, horizontal ladder test, and footprint analysis. Magnetic resonance imaging, histological examination, transmission electron microscopy observation, immunofluorescence staining, and western blotting were performed 8 weeks after spinal cord injury to further explore the potential mechanism behind the synergistic repair effect. In vivo, the combination of bone marrow mesenchymal stem cell transplantation and exercise showed a better therapeutic effect on motor function than the single treatments. Further investigations revealed that the combination of bone marrow mesenchymal stem cell transplantation and exercise markedly reduced fibrotic scar tissue, protected neurons, and promoted axon and myelin protection. Additionally, the synergistic effects of bone marrow mesenchymal stem cell transplantation and exercise on spinal cord injury recovery occurred via the PI3K/AKT/mTOR pathway. In vitro, experimental evidence from the PC12 cell line and primary cortical neuron culture also demonstrated that blocking of the PI3K/AKT/mTOR pathway would aggravate neuronal damage. Thus, bone marrow mesenchymal stem cell transplantation combined with exercise training can effectively restore motor function after spinal cord injury by activating the PI3K/AKT/mTOR pathway.

Abstract Background This study probes into the function and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived exosomes loaded with miR-150-5p in mechanical allodynia. Methods BMSCs were infected with miR-150-5p inhibition lentiviruses to obtain exosomes with low miR-150-5p expression. A L5 spinal nerve ligation (SNL) model was established in rats where exosomes, NOTCH2 overexpression/inhibition plasmids, or microglial cells were intrathecally administered. Hind paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) of rats were measured. TUNEL staining was used to measure the apoptotic rate in rat spinal dorsal horn (SDH), ELISA to evaluate pro-inflammatory factor levels, and RT-qPCR, western blotting, and immunohistochemistry to detect miR-150-5p and NOTCH2 expression. Immunofluorescence was used for localizing exosomes and NOTCH2 and detecting the expression of OX42, a maker for microglia. Dual luciferase reporter and RNA pull down assays were performed to validate the putative binding between miR-150-5p and NOTCH2. Results NOTCH2 expressed at a high level and miR-150-5p was downregulated in SDH of SNL rats. Exosomes injected were localized in rat SDH. BMSC-exosomes or NOTCH2 downregulation increased PWT and PWL of SNL rats and reduced apoptosis and inflammation in SDH. In contrast, NOTCH2 overexpression aggravated mechanical allodynia and SDH injury. Moreover, inhibiting miR-150-5p in BMSC-exosomes offset the therapeutic effects of BMSC-exosomes. Microglia activation induced mechanical allodynia in wild rats, while intrathecal injection of microglial cells incubated with BMSC-exosomes showed alleviated mechanical allodynia in SNL rats. NOTCH2 was targeted by miR-150-5p. Conclusion BMSC-derived exosomal miR-150-5p alleviates mechanical allodynia by targeting NOTCH2 in microglial cells.

Interleukin (IL)− 33 is a tissue-derive proinflammatory cytokine that promotes fibrosis in systemic sclerosis (SSc). microRNA (miR)− 214 expression has been elaborated to be downregulated in SSc patients and exert anti-fibrotic and anti-inflammatory effects. This study elucidates the role of bone marrow mesenchymal stem cell-derived exosome (BMSC-Exos)-delivered miR-214 in SSc and the relationship between this miR and IL-33/ST2 axis. SSc clinical samples were obtained to evaluate levels of miR-214, IL-33, and ST2. Primary fibroblasts and BMSC-Exos were extracted, followed by the co-culture of PKH6-labeled BMSC-Exos and fibroblasts. Subsequently, Exos extracted from miR-214 inhibitor-transfected BMSCs were co-cultured with TGF-β1-stimulated fibroblasts, after which the expression of fibrotic markers, miR-214, IL-33, and ST2, as well as fibroblast proliferation and migration, was determined. A skin fibrosis mouse model was induced with bleomycin (BLM) and treated with BMSC-Exos. Collagen fiber accumulation, collagen content, α-SMA expression, and IL-33 and ST2 levels were examined in BLM-treated or IL-33-knockout mice. IL-33 and ST2 were upregulated and miR-214 was downregulated in SSc patients. Mechanistically, miR-214 targeted IL-33 and blocked the IL-33/ST2 axis. BMSC-Exos delivering miR-214 inhibitor augmented proliferation, migration, and fibrotic gene expression in TGF-β1-stimulated fibroblasts. Similarly, IL-33 induced migration, proliferation, and fibrotic gene expression in fibroblasts via ST2. In BLM-treated mice, IL-33 knockout suppressed skin fibrosis, and BMSC-Exos delivered miR-214 to suppress the IL-33/ST2 axis, thus mitigating skin fibrosis. Conclusively, BMSC-Exos alleviate skin fibrosis through the blockade of the IL-33/ST2 axis by delivering miR-214. • BMSC-exosomal miR-214 inhibits fibroblast growth, migration, and collagenation. • miR-214 targets and negatively regulates IL-33. • IL-33 knockout retards fibrotic progression of mouse skins. • IL-33 induces fibroblast growth, migration, and collagenation via ST2. • BMSC-Exo delivers miR-214 to inhibit skin fibrosis by suppressing IL-33/ST2. [ABSTRACT FROM AUTHOR]

Background. Bone mesenchymal stem cell (BMSC)-derived exosomes (B-exos) are attractive for applications in enabling alloantigen tolerance. An in-depth mechanistic understanding of the interaction between B-exos and dendritic cells (DCs) could lead to novel cell-based therapies for allogeneic transplantation. Objectives. To examine whether B-exos exert immunomodulatory effects on DC function and maturation. Materials and methods. After mixed culture of BMSCs and DCs for 48 h, DCs from the upper layer were collected to analyze the expression levels of surface markers and mRNAs of inflammation-related cytokines. Then, before being collected to detect the mRNA and protein expression levels of indoleamine 2,3-dioxygenase (IDO), the DCs were co-cultured with B-exos. Then, the treated DCs from different groups were cocultured with naïve CD4+ T cells from the mouse spleen. The proliferation of CD4+ T cells and the proportion of CD4+CD25+Foxp3+ T cells were analyzed. Finally, the skins of BALB/c mice were transplanted to the back of C57 mice in order to establish a mouse allogeneic skin transplantation model. Results. The co-culture of DCs with BMSCs downregulated the expression of the major histocompatibility complex class II (MHC-II) and CD80/86 costimulatory molecules on DCs. Moreover, B-exos increased the expression of IDO in DCs treated with lipopolysaccharide (LPS). The proliferation of CD4+CD25+Foxp3+ T cells increased when cultured with B-exos-exposed DCs. Finally, mice recipients injected with B-exos-treated DCs had significantly prolonged survival after receiving the skin allograft. Conclusions. Taken together, these data suggest that the B-exos suppress the maturation of DCs and increase the expression of IDO, which might shed light on the role of B-exos in inducing alloantigen tolerance. [ABSTRACT FROM AUTHOR]

Abstract Pneumonia is one of the leading causes of death in patients with acute ischemic stroke (AIS). Antibiotics fail to improve prognosis of patients with post‐stroke pneumonia, albeit suppressing infection, due to adverse impacts on the immune system. The current study reports that bone marrow mesenchymal stem cells (BM‐MSC) downregulate bacterial load in the lungs of stroke mice models. RNA‐sequencing of the lung from BM‐MSC‐treated stroke models indicates that BM‐MSC modulates pulmonary macrophage activities after cerebral ischemia. Mechanistically, BM‐MSC promotes the bacterial phagocytosis of pulmonary macrophages through releasing migrasomes, which are migration‐dependent extracellular vesicles. With liquid chromatography‐tandem mass spectrometry (LC‐MS/MS), the result shows that BM‐MSC are found to load the antibacterial peptide dermcidin (DCD) in migrasomes upon bacterial stimulation. Besides the antibiotic effect, DCD enhances LC3‐associated phagocytosis (LAP) of macrophages, facilitating their bacterial clearance. The data demonstrate that BM‐MSC is a promising therapeutic candidate against post‐stroke pneumonia, with dual functions of anti‐infection and immunol modulation, which is more than a match for antibiotics treatment.

Background: Tympanic membrane perforation (TMP) is a common disease in otology, and few acellular techniques have been reported for repairing this condition. Decellularized extracellular matrix (ECM) scaffolds have been used in organ reconstruction. Objective: This study on tissue engineering aimed to develop a tympanic membrane (TM) scaffold prepared using detergent immersion and bone marrow mesenchymal stem cells (BMSCs) as repair materials to reconstruct the TM. Results: General structure was observed that the decellularized TM scaffold with BMSCs retained the original intact anatomical ECM structure, with no cell residue, as observed using scanning electron microscopy (SEM), and exhibited low immunogenicity. Therefore, we seeded the decellularized TM scaffold with BMSCs for recellularization. Histology and eosin staining, SEM and immunofluorescence in vivo showed that the recellularized TM patch had a natural ultrastructure and was suitable for the migration and proliferation of BMSCs. The auditory brainstem response (ABR) evaluated after recellularized TM patch repair was slightly higher than that of the normal TM, but the difference was not significant. Conclusion: The synthetic ECM scaffold provides temporary physical support for the three‐dimensional growth of cells during the tissue developmental stage. The scaffold stimulates cells to secrete their own ECM required for tissue regeneration. The recellularized TM patch shows potential as a natural, ultrastructure biological material for TM reconstruction. [ABSTRACT FROM AUTHOR]

Hypothesis: We hypothesized that Lomecel‐B, an allogeneic medicinal signaling cell (MSC) therapeutic candidate for Alzheimer's disease (AD), is safe and potentially disease‐modifying via pleiotropic mechanisms of action. Key Predictions: We prospectively tested the predictions that Lomecel‐B administration to mild AD patients is safe (primary endpoint) and would provide multiple exploratory indications of potential efficacy in clinical and biomarker domains (prespecified secondary/exploratory endpoints). Strategy and Key Results: Mild AD patient received a single infusion of low‐ or high‐dose Lomecel‐B, or placebo, in a double‐blind, randomized, phase I trial. The primary safety endpoint was met. Fluid‐based and imaging biomarkers indicated significant improvement in the Lomecel‐B arms versus placebo. The low‐dose Lomecel‐B arm showed significant improvements versus placebo on neurocognitive and other assessments. Interpretation: Our results support the safety of Lomecel‐B for AD, suggest clinical potential, and provide mechanistic insights. This early‐stage study provides important exploratory information for larger efficacy‐powered clinical trials. [ABSTRACT FROM AUTHOR]

The comprehensive recognition of communications between bone marrow mesenchymal stem cells (bm-MSCs) and macrophages in the peri-implant microenvironment is crucial for implantation prognosis. Our previous studies have clarified the indirect influence of Ti surface topography in the osteogenic differentiation of bm-MSCs through modulating macrophage polarization. However, cell communication is commutative and multi-directional. As the immune regulatory properties of MSCs have become increasingly prominent, whether bm-MSCs could also play an immunomodulatory role on macrophages under the influence of Ti surface topography is unclear. To further illuminate the communications between bm-MSCs and macrophages, the bm-MSCs inoculated on Ti with nanoporous topography were indirectly co-cultured with macrophages, and by blocking exosome secretion or extracting the purified exosomes to induce independently, we bidirectionally confirmed that under the influence of TiO2 nanoporous topography with 80–100 nm tube diameters, bm-MSCs can exert immunomodulatory effects through exosome-mediated paracrine actions and induce M1 polarization of macrophages, adversely affecting the osteogenic microenvironment around the implant. This finding provides a reference for the optimal design of the implant surface topography for inducing better bone regeneration. [ABSTRACT FROM AUTHOR]

Today, communities and their health systems are facing with several challenges associated with the population ageing. Growing number of bone disorders is one of the most serious consequences of aging. According to the reports bone disorders won't just affect the elderly population. Mesenchymal stem cells (MSCs) are multipotent cells that could be derived from a variety of tissues including bone marrow, Wharton's Jelly, adipose tissue, and others. MSCs have been utilized in different researches in the field of regenerative medicine because of their immunosuppression and anti-inflammatory mechanisms (like: inhibiting the activity of antigen presenting cells, and suppressing the activity of T lymphocyte cells, macrophages, and so on.), migration to injured areas, and participation in healing processes. Bone marrow mesenchymal stem cells (BMMSCs) are a type of these cells which can be commonly used in bone research with the promising results. These cells function by releasing a large number of extracellular vesicles (EVs). Exosomes are the most major EVs products produced by BMMSCs. They have the same contents and properties as their parent cells; however, these structures don't have the defects of cell therapy. Proteins (annexins, tetraspannins, etc.), lipids (cholesterol, phosphoglycerides, etc.), nucleic acids (micro-RNAs, and etc.) and other substances are found in exosomes. Exosomes affect target cells, causing them to change their function. The features of BMMSC exosomes' mechanism in osteogenesis and bone regeneration (like: effects on other MSCs, osteoblasts, osteoclasts, and angiogenesis) and also the effects of their micro-RNAs on osteogenesis are the subject of the present review. [ABSTRACT FROM AUTHOR]

Background and Aim: Bone marrow-derived mesenchymal stem cells (BM-MSCs) transplantation and their hepatogenic differentiated cells (HDCs) can be applied for liver injury repair by tissue grafting. Regenerative potentiality in liver cirrhosis models was widely investigated; however, immunomodulation and anti-inflammation in acute hepatitis remain unexplored. This study aimed to explore the immunomodulatory and evaluate twice intravenous (IV) or intrahepatic (IH) administration of either BM-MSCs or middle-stage HDCs on aflatoxin (AF) acute hepatitis rat model. Materials and Methods: BM-MSCs viability, phenotypes, and proliferation were evaluated. Hepatogenic differentiation, albumin, and a-fetoprotein gene expression were assessed. AF acute hepatitis was induced in rats using AFB1 supplementation. The transplantation of BM-MSCs or their HDCs was done either by IV or IH route. Hepatic ultrasound was performed after 3-weeks of therapy. Cytokines profile (tumor necrosis factor-α [TNF-α], interleukin [IL]-4, and IL-10) was assessed. Hepatic bio-indices, serum, and hepatic antioxidant activity were evaluated, besides examining liver histological sections. Results: Acute AFB1 showed a significant increase in TNF-α (p

Abstract Background While prostate cancer (PCa) cells most often metastasize to bone in men, species-specific differences between human and mouse bone marrow mean that this pattern is not faithfully replicated in mice. Herein we evaluated the impact of partially humanizing mouse bone marrow with human bone marrow-derived stromal cells (BMSC, also known as "mesenchymal stem cells") on human PCa cell behaviour. Methods BMSC are key cellular constituents of marrow. We used intrafemoral injection to transplant 5 × 105 luciferase (Luc) and green fluorescence protein (GFP) expressing human BMSC (hBMSC-Luc/GFP) into the right femur of non-obese diabetic (NOD)-severe combined immunodeficiency (scid) interleukin (IL)-2γ−/− (NSG) mice. Two weeks later, 2.5 × 106 PC-3 prostate cancer cells expressing DsRed (PC-3-DsRed) were delivered into the mice via intracardiac injection. PC-3-DsRed cells were tracked over time using an In Vivo Imaging System (IVIS) live animal imaging system, X-ray and IVIS imaging performed on harvested organs, and PC-3 cell numbers in femurs quantified using flow cytometry and histology. Results Flow cytometry analysis revealed greater PC-3-DsRed cell numbers within femurs of the mice that received hBMSC-Luc/GFP. However, while there were overall greater PC-3-DsRed cell numbers in these animals, there were not more PC-3-DsRed in the femurs injected with hBMSC-Luc/GFP than in contralateral femurs. A similar proportion of mice in with or without hBMSC-Luc/GFP had bone lessions, but the absolute number of bone lesions was greater in mice that had received hBMSC-Luc/GFP. Conclusion PC-3-DsRed cells preferentially populated bones in mice that had received hBMSC-Luc/GFP, although PC-3-DsRed cells not specifically localize in the bone marrow cavity where hBMSC-Luc/GFP had been transplanted. hBMSC-Luc/GFP appear to modify mouse biology in a manner that supports PC-3-DsRed tumor development, rather than specifically influencing PC-3-DsRed cell homing. This study provides useful insights into the role of humanizing murine bone marrow with hBMSC to study human PCa cell biology.

Bone marrow mesenchymal stem cells (BMSCs) are integral to bone remodeling and homeostasis, as they are capable of differentiating into osteogenic and adipogenic lineages. This differentiation is substantially influenced by mechanosensitivity, particularly to tensile strain, which is a prevalent mechanical stimulus known to enhance osteogenic differentiation. This review specifically examines the effects of various cyclic tensile stress (CTS) conditions on BMSC osteogenesis. It delves into the effects of different loading devices, magnitudes, frequencies, elongation levels, dimensionalities, and coculture conditions, providing a comparative analysis that aids identification of the most conducive parameters for the osteogenic differentiation of BMSCs. Subsequently, this review delineates the signaling pathways activated by CTS, such as Wnt/β-catenin, BMP, Notch, MAPK, PI3K/Akt, and Hedgehog, which are instrumental in mediating the osteogenic differentiation of BMSCs. Through a detailed examination of these pathways, this study elucidates the intricate mechanisms whereby tensile strain promotes osteogenic differentiation, offering valuable guidance for optimizing therapeutic strategies aimed at enhancing bone regeneration. • Mechanical stimuli play a pivotal role in regulating bone marrow mesenchymal stem cells (BMSCs) lineage commitment. • Appropriate cyclic tensile strain (CTS) parameters contribute to enhance BMSCs differentiation toward osteogenic lineages. • CTS promotes BMSCs osteogenesis via Wnt/β-catenin, BMP, Notch, MAPK, PI3K/Akt and Hedgehog signaling pathways. [ABSTRACT FROM AUTHOR]

The culture system of bone marrow mesenchymal stem cells (bmMSCs) in the normoxic environment does not imitate the hypoxic milieu of typical biological conditions, thus hypoxic culture conditions may improve survival, and growth attributes of bmMSCs during in vitro culture. Therefore, the present study was conducted at ICAR-CIRG, Makhdoom during year 2020 with the objective to investigate the changes in biological characteristics of cultured caprine bmMSCs (cbmMSCs) including the cellular senescence, survival, rate of proliferation, immuno-phenotypic characteristics, and gene expression pattern in a normal and hypoxic microenvironment condition. For this, cbmMSCs isolated from bone marrow collected from iliac crest were enriched and grown under either hypoxic (5% O2) or normoxic (20% O2) conditions. Thereafter, the outcome of hypoxic (5% O2) culturing of cbmMSCs on growth characteristics, proliferation, senescence, and expression profile of important stemness-associated (OCT-4) and oxidative stress [glutathione peroxidase (GPx1) and copper-zinc superoxide dismutase (CuZnSOD)] marker genes was evaluated. cbmMSCs cultivated in hypoxic conditions showed higher proliferation and decreased population doubling time and senescence-associated β-GAL expression; however, the immune-phenotypic characteristics of the cells remain unchanged. Furthermore, the culture of cbmMSCs in hypoxia increased the expression of OCT-4, GPx1, and CuZnSOD, compared with the cells grown under normoxia. In conclusion, the culture condition with low O2 level improved the growth characteristics and proliferation of cbmMSCs. These outcomes would provide information to formulate strategies for the collection and efficient in vitro expansion of bmMSCs from goats and other farm animals before their downstream applications.

Hypoxic–ischemic brain damage (HIBD) is a major cause of brain injury in neonates. Bone marrow mesenchymal stem cells (BMSCs) show therapeutic potential for HIBD, and genetic modification may enhance their neuroprotective effects. The goal of this study was to investigate the neuroprotective effects of hepatocyte growth factor (HGF)-overexpressing BMSCs (BMSCs-HGF) against HIBD and their underlying mechanisms.

Background: This study probes into the function and mechanism of bone marrow mesenchymal stem cell (BMSC)-derived exosomes loaded with miR-150-5p in mechanical allodynia. Methods: BMSCs were infected with miR-150-5p inhibition lentiviruses to obtain exosomes with low miR-150-5p expression. A L5 spinal nerve ligation (SNL) model was established in rats where exosomes, NOTCH2 overexpression/inhibition plasmids, or microglial cells were intrathecally administered. Hind paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) of rats were measured. TUNEL staining was used to measure the apoptotic rate in rat spinal dorsal horn (SDH), ELISA to evaluate pro-inflammatory factor levels, and RT-qPCR, western blotting, and immunohistochemistry to detect miR-150-5p and NOTCH2 expression. Immunofluorescence was used for localizing exosomes and NOTCH2 and detecting the expression of OX42, a maker for microglia. Dual luciferase reporter and RNA pull down assays were performed to validate the putative binding between miR-150-5p and NOTCH2. Results: NOTCH2 expressed at a high level and miR-150-5p was downregulated in SDH of SNL rats. Exosomes injected were localized in rat SDH. BMSC-exosomes or NOTCH2 downregulation increased PWT and PWL of SNL rats and reduced apoptosis and inflammation in SDH. In contrast, NOTCH2 overexpression aggravated mechanical allodynia and SDH injury. Moreover, inhibiting miR-150-5p in BMSC-exosomes offset the therapeutic effects of BMSC-exosomes. Microglia activation induced mechanical allodynia in wild rats, while intrathecal injection of microglial cells incubated with BMSC-exosomes showed alleviated mechanical allodynia in SNL rats. NOTCH2 was targeted by miR-150-5p. Conclusion: BMSC-derived exosomal miR-150-5p alleviates mechanical allodynia by targeting NOTCH2 in microglial cells. [ABSTRACT FROM AUTHOR]

Bone marrow mesenchymal stem cell (BMSC) is previously reported to present a certain effect on treating spinal cord injury (SCI), while the underlying mechanism is largely uncovered. Therefore, the current study aimed to investigate the involvement of exosome-delivered circRNA profile in the BMSC's effect on pyroptosis for SCI treatment. H2O2 treated rat primary neurons were cultured with normal medium, BMSC, BMSC plus GW4869, and BMSC-derived exosome, respectively, then inflammasome-related pyroptosis markers, and circRNA profiles were detected. Subsequently, circ_003564-knockdown BMSC exosome was transfected into H2O2 treated rat primary neurons and NGF-stimulated PC-12 cells. Furthermore, in vivo validation was conducted. BMSC and BMSC-derived exosome both decreased inflammasome-related pyroptosis markers including cleaved caspase-1, GSDMD, NLRP3, IL-1β, and IL-18 in H2O2-treated neurons, while exosome-free BMSC (BMSC plus GW4869) did not obviously reduce these factors. Microarray assay revealed that BMSC (vs. exosome-free BMSC) and BMSC-derived exosome (vs. normal medium) greatly regulated circRNA profiles, which were enriched in neuroinflammation pathways (such as neurotrophin, apoptosis, and TNF). Among three functional candidate circRNAs (circ_015525, circ_008876, and circ_003564), circ_003564 was most effective to regulate inflammasome-related pyroptosis. Interestingly, circ_003564-knockdown BMSC exosome showed higher expression of inflammasome-related pyroptosis markers compared to negative-control-knockdown BMSC exosome in H2O2 treated primary neurons/NGF-stimulated PC-12 cells. In vivo, BMSC exosome improved the function recovery and decreased tissue injury and inflammasome-related pyroptosis in SCI rats, whose effect was attenuated by circ_003564 knockdown transfection. BMSC exosome attenuates inflammasome-related pyroptosis via delivering circ_003564, contributing to its treatment efficacy for SCI. [ABSTRACT FROM AUTHOR]

Background. In the bone marrow microenvironment of postmenopausal osteoporosis (PMOP), bone marrow mesenchymal stem cell (BMSC)-derived exosomal miRNAs play an important role in bone formation and bone resorption, although the patho-genesis has yet to be clarified. Methods. BMSC-derived exosomes from ovariectomized rats (OVX-Exo) and sham-operated rats (Sham-Exo) were co-cultured with bone marrow-derived macrophages to study their effects on osteoclast differentiation. Next-generation sequencing was utilized to identify the differentially expressed miRNAs (DE-miRNAs) between OVX-Exo and Sham-Exo, while target genes were analyzed using bioinformatics. The regulatory effects of miR-27a-3p and miR-196b-5p on osteogenic differentiation of BMSCs and osteoclast differentiation were verified by gain-of-function and loss-of-function analyses. Results. Osteoclast differentiation was significantly enhanced in the OVX-Exo treat-ment group compared to the Sham-Exo group. Twenty DE-miRNAs were identified between OVX-Exo and Sham-Exo, among which miR-27a-3p and miR-196b-5p promoted the expressions of osteogenic differentiation markers in BMSCs. In contrast, knockdown of miR-27a-3p and miR-196b-5p increased the expressions of osteoclastic markers in osteoclast. These 20 DE-miRNAs were found to target 11435 mRNAs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that these target genes were involved in several biological processes and osteoporosis-related signaling pathways. Conclusion. BMSC-derived exosomal miR-27a-3p and miR-196b-5p may play a positive regulatory role in bone remodeling. [ABSTRACT FROM AUTHOR]

Background/aim: Pelvic floor dysfunctions (PFDs), which encompass pelvic organ prolapse (POP), stress urinary incontinence (SUI), and anal incontinence (AI), are common degenerative diseases in women. Bone marrow mesenchymal stem cells (BMSCs) hold promise for the treatment of PFDs. Extracellular vesicles (EVs) derived from BMSCs, have displayed an extensive role in intercellular communication and tissue repair. However, efficacy of the treatment using EVs originated from BMSCs on mouse models of PFD remains unknown. This study investigated the therapeutic potential of BMSC-derived EVs in a female PFD mouse model induced by vaginal distension (VD)., Materials and Methods/results: Flow cytometry analysis confirmed the positive expression of BMSC-related markers, and successful induction of multilineage differentiation further validated their characteristics. As expected, the EVs extracted from BMSCs exhibited typical cup-shaped and circular-shaped structures. In the PFD model, BMSC-derived EVs significantly reduced the levels of inflammatory cytokines (p<0.05), improved tissue repair, and mitigated neutrophil infiltration. Furthermore, EVs promoted cell proliferation, decreased expression of relaxin receptors, increased expression of elastin, and elevated collagen content in the anterior vaginal wall tissue (p<0.05), suggesting beneficial effects on tissue regeneration and connective tissue restoration in PFD., Conclusion: BMSC-derived EVs effectively reduce tissue inflammation, promote tissue regeneration and connective tissue reconstruction, and improve pelvic support deficiency, thereby alleviating PFD induced by vaginal distension (VD) in vivo., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)