Ammonium Persulfate-Loaded Carboxylic Gelatin-Methacrylate Nanoparticles Promote Cardiac Repair by Activating Epicardial Epithelial-Mesenchymal Transition via Autophagy and the mTOR Pathway.

Restoring damaged myocardial tissue with therapeutic exogenous cells still has some limitations, such as immunological rejection, immature cardiac properties, risk of tumorigenicity, and a low cell survival rate in the ischemic myocardium microenvironment. Activating the endogenous stem cells with functional biomaterials might overcome these limitations. Research has highlighted the multiple differentiation potential of epicardial cells via epithelial-mesenchymal transition (EMT) in both heart development and cardiac regeneration. In our previous research, a carboxylic gelatin-methacrylate (carbox-GelMA) nanoparticle (NP) was fabricated to carry ammonium persulfate (APS), and APS-loaded carbox-GelMA NPs (NPs/APS) could drive the EMT of MCF-7 cells in vitro and promote cancer cell migration and invasion in vivo. The present study explored the roles of functional NPs/APS in the EMT of Wilms' tumor 1-positive (WT1+) epicardial cells and in the repair of myocardial infarction (MI). The WT1+ epicardial cells transformed into endothelial-like cells after being treated with NPs/APS in vitro, and the cardiac functions were improved significantly after injecting NPs/APS into the infarcted hearts in vivo. Furthermore, simultaneous activation of both autophagy and the mTOR pathway was confirmed during the NPs/APS-induced EMT process in WT1+ epicardial cells. Together, this study highlights the function of NPs/APS in the repair of MI.

Dural arteriovenous fistula with spinal dural arteriovenous fistula: a case report and review of the literature.

BACKGROUND: This paper analyzed the cases of dural arteriovenous fistula (DAVF) with spinal dural arteriovenous fistula (SDAVF) in the diagnosis and treatment process. CASE PRESENTATION: One case involving dural arteriovenous fistula (DAVF) with spinal dural arteriovenous fistula (SDAVF) from the 306th Hospital of PLA was retrospectively analyzed. The patient consulted the doctor due to lower limb sensory and motor disorders while exhibiting symptoms of urinary dysfunction. A computed tomographic angiography (CTA) and cerebral angiography confirmed the diagnosis of dural arteriovenous fistula (DAVF), necessitating surgical treatment. The patient was referred to our hospital for an magnetic resonance imaging (MRI) and a spinal angiography to obtain a confirmed diagnosis for spinal arteriovenous fistula, after which they underwent surgical fistula resection. The invasive intracranial dural arteriovenous fistula (DAVF) resection proceeded smoothly but did not ease the patient's symptoms. However, postoperative symptoms were partially relieved by the lumbar open spinal dural arteriovenous fistula adminstration. CONCLUSIONS: Since not enough is understood about these two diseases, the rate of misdiagnosis is significantly increased. Early diagnosis and treatment of spinal dural arteriovenous fistula (SDAVF) can play a positive role during the recovery from neural function damage.

Therapeutic effects of mesenchymal stem cells loaded with oncolytic adenovirus carrying decorin on a breast cancer lung metastatic mouse model.

Oncolytic adenoviruses (OAds) are alternative immune therapeutic strategies for tumors. However, liver uptake and antibody neutralization are two major barriers for systemic delivery during the treatment of tumor metastasis. Mesenchymal stem cells (MSCs) have emerged as potential vehicles to improve delivery. In this study, we loaded umbilical-cord-derived MSCs (UC-MSCs) with OAds expressing decorin (rAd.DCN) or without foreign genes (rAd.Null) to treat breast cancer lung metastasis. In vivo, rAd.Null, MSCs.Null, and rAd.DCN exhibited antitumor effects compared with other groups in a mouse model. Unexpectedly, MSCs.Null showed much greater antitumor responses than MSCs.DCN, including improved survival and reduced tumor burden. Compared with rAd.Null, both MSCs.Null and MSCs.DCN could improve the viral spread and distribution in metastatic tumor lesions in the lung. MSCs.DCN produced much more decorin in lungs than rAd.DCN; however, rAd.DCN reduced the downstream target genes of decorin much more strongly than MSCs.DCN, which was consistent with in vitro findings. In addition, rAd.DCN, MSCs.Null, and MSCs.DCN could reduce The cytokine levels in the lung. In conclusion, MSCs improved oncolytic adenoviral delivery and spread in tumor tissues and enhanced therapeutic effects. However, MSCs.DCN reduced OAd-evoked antitumor responses, possibly via a contact-dependent mechanism.

Dental Pulp Stem Cell-Derived Extracellular Vesicles Mitigate Haematopoietic Damage after Radiation.

Radiation therapy can cause haematopoietic damage, and mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) have been shown to reverse this damage. Our previous research showed that dental pulp stem cells (DPSCs) have a strong proliferation capacity and can produce abundant amounts of EVs to meet the requirements for use in vitro and in vivo. DPSCs derived EVs (DPSCs-EVs) are evaluated for their effect on reducing haematopoietic damage. Haematopoietic stem cell (HSC) numbers and function were assessed by flow cytometry, peripheral blood cell counts, histology and bone marrow transplantation. Epidermal growth factor (EGF) was used as a reference for evaluating the efficiency of EVs. miRNA microarray was employed to find out the changes of miRNA expression after cells being irradiated in vivo and the role they may play in mitigation the radiation caused injury. We observed the effect of DPSCs-EVs on promoting proliferation and inhibiting apoptosis of human umbilical vein endothelial cells (HUVECs) and FDC-P1 cells in vitro. We found that DPSCs-EVs and EGF could comparably inhibit the decrease in WBC, CFU count and KSL cells in vivo. We also verified that EVs could accelerate the recovery of long-term HSCs. In summary, DPSCs-EVs showed an apoptosis resistant effect on HUVECs and FDC-P1 cells after radiation injury in vitro. EVs from DPSCs were comparable to EGF in their ability to regulate haematopoietic regeneration after radiation injury in vivo. Radiation could alter the expression of some miRNAs in bone marrow cells, and EVs could correct these changes to some extent. Graphical abstract.

Effect of simulated microgravity conditions of hindlimb unloading on mice hematopoietic and mesenchymal stromal cells.

Conditions in space, such as microgravity, may affect the hematopoietic and bone marrow-derived mesenchymal stromal cells (BM-MSCs) of astronauts. However, to date, few detailed phenotype change data about the different type of hematopoietic cells have reported. In this study, C57BL/6 mice were randomly divided into two groups: a control group (control) and a hindlimb suspension group (treated). After four weeks of hindlimb suspension, we found that this simulated microgravity (sµg) condition could increase the percentage of monocytes and macrophages and decrease the percentage of B lymphocytes and mature red cells in bone marrow. The percentage of B lymphocytes in the spleen and the red blood cell count in peripheral blood also decreased, consistent with the response of bone marrow. The cytoskeleton in the BM-MSCs was disrupted. The expression levels of hematopoietic-related genes, such as fms-like tyrosine kinase-3 ligand, granulocyte-macrophage colony stimulating factor, interleukin-3, and adipogenic differentiation associated genes, leptin and proliferator-activated receptor γ type 2, were upregulated under sµg conditions. These results indicated that simulating microgravity can affect the phenotype of certain types of hematopoietic cells and the morphology and gene expression pattern of BM-MSCs.

Pulp stem cells with hepatocyte growth factor overexpression exhibit dual effects in rheumatoid arthritis.

BACKGROUND: To investigate the therapeutic effect of human dental pulp stem cells (DPSCs) transfected with adenovirus expressing hepatocyte growth factor (HGF) in a mouse model of collagen-induced arthritis (CIA). METHODS: DPSCs were modified with Ad-HGF to produce HGF-overexpressing DPSCs, DPSCs-HGF. In experimental mouse CIA model, DPSCs-HGF and DPSCs-Null (modified with Ad-Null) were engrafted via intravenously after disease onset, which was determined by the presence of joint swelling. The therapeutic effects on joints were evaluated at 49 days after collagen injection by histopathological analysis and microcomputed tomography imaging. The inflammatory cytokines were analyzed both in sera and joints via MILLIPLEX kit and immunohistochemical staining, respectively, and the regulatory T cells (Tregs) were analyzed in peripheral blood by using flow cytometry. Furthermore, primary fibroblast-like synoviocytes were isolated, colony formation analysis and FACS were performed to evaluate the effect of HGF on the proliferation and cell cycle of FLSs. Western blot assay was carried out to clarify the signal pathway of HGF-cMet. RESULTS: We found that without HGF modification, DPSC transfusion was helpful in controlling autoimmune status, local synovitis, and bone erosion after intravenous administration. However, HGF-modified DPSCs have dual role in rheumatoid arthritis (RA). In the early phase, HGF overexpression inhibited RA progression by its immunosuppressive effects, while in the late phase, HGF promoted synovitis by activating fibroblast-like synoviocytes to produce pathogenic IL-6, accelerating cell proliferation and inducing apoptosis resistance via phosphorylating the c-Met/Akt pathway. The overall effect of HGF modification attenuated the therapeutic effect of DPSCs. CONCLUSIONS: Our study provides a comprehensive evaluation of the therapeutic effect of DPSCs in the mouse model and a primary answer to the divergence of whether HGF is harmful or helpful in RA.

Spred2 inhibits epithelial­mesenchymal transition of colorectal cancer cells by impairing ERK signaling.

Downregulation of the sprouty­related EVH1 domain protein 2 (Spred2) is closely associated with highly metastatic phenotypes in various tumors. However, the roles of Spred2 in the development and progression of colorectal cancer (CRC) are still largely unexplored. As anticipated, Spred2 expression was significantly downregulated in clinical tumor tissues. To restore Spred2 levels, Ad.Spred2, an adenoviral vector expressing Spred2, was transduced into CRC cells. It was revealed that Ad.Spred2 inhibited the proliferation and decreased the survival and migration of SW480 cells. Epithelial­mesenchymal transition (EMT) is an essential event during tumor metastasis to distant sites. It was revealed that Ad.Spred2 markedly inhibited EMT by promoting F­actin reorganization, upregulating E­cadherin levels and reducing vimentin protein expression. Notably, extracellular­regulated kinase (ERK) signaling inhibition by PD98059 induced similar effects on EMT in CRC cells, indicating that Ad.Spred2 regulated EMT in CRC cells in an ERK­dependent manner. Transforming growth factor ß (TGF­ß), a well­known inducer of EMT, increased E­cadherin expression, decreased vimentin expression and promoted migration in CRC cells. However, neither Ad.Spred2 nor PD98059 had an obvious effect on the expression of SMAD2/3 or SMAD4 in SW480 cells, indicating that Ad.Spred2 inhibited EMT in a SMAD­independent manner. Notably, Ad.Spred2 transduction downregulated SAMD2/3 and SMAD4 levels in HCT116 cells in an ERK­independent manner. It was speculated that Ad.Spred2 inhibited the EMT of HCT116 cells by both blocking ERK signaling and reducing SMAD signaling. It was concluded that Spred2 inhibited EMT in CRC cells by interfering with ERK signaling, with or without reduced SMAD signaling. Therefore, the introduction of the clinical application of Spred2 has great potential for development as a gene therapy approach for CRC.

Effects of the Preparation Conditions and Reinforcement Mechanism of Polyvinyl Acetate Soil Stabilizer.

The significant criterion for evaluating the merits of a new type of high molecular polymer lies in its engineering properties and eco-friendliness. The focus of this study was to determine the effects of preparation conditions on the viscosity of the polyvinyl acetate (PVAc) emulsion, including reaction temperature (Tr), initiator concentration (CAPS), monomer concentration (CVA), pH value, and degree of dilution (Ddi). Based on the results of a series of laboratory tests, the range of viscosity value of PVAc was obtained under different conditions, and one set of viscosity values out of these was applied to soil reinforcement tests. Meanwhile, based on the test results, the engineering properties of PVAc solution were evaluated using strength and moisture retention tests, and the reinforcement mechanism was analyzed using scanning electron microscopy (SEM). In addition, it was proven through a vegetation growth test that the PVAc was eco-friendly.

Oncolytic Adenovirus rAd.DCN Inhibits Breast Tumor Growth and Lung Metastasis in an Immune-Competent Orthotopic Xenograft Model.

The majority of advanced breast cancer patients develop distal metastasis, including lung and bone metastasis. However, effective therapeutic strategies to prevent metastasis are still lacking. Decorin is a natural inhibitor of transforming growth factor ß, which plays a pivotal role in tumor metastasis. An oncolytic adenovirus expressing decorin, rAd.DCN, has been developed previously. In an immune-competent breast tumor (4T1) model, intratumoral (i.t.) as well as intravenous (i.v.) delivery of rAd.DCN inhibited growth of orthotopic tumors and spontaneous lung metastasis. It was shown that i.t. delivery of rAd.DCN produced higher levels of transgene expression and evoked stronger oncolysis of the tumors compared to i.v. delivery. However, i.v. delivery resulted in higher amount of virus accumulation in the lungs and produced stronger responses to prevent tumor lung metastasis. Oncolytic adenovirus-mediated decorin expression in the tumors downregulated the decorin target genes and decreased epithelial mesenchymal transition markers. Decorin expression in lung tissues also increased Th1 cytokine expression, such as interleukin (IL)-2, IL-12, and tumor necrosis factor α, and decreased Th2 cytokines, such as transforming growth factor ß and IL-6. Moreover, rAd.DCN treatment induced strong systemic inflammatory responses and upregulated CD8+ T lymphocytes. In conclusion, rAd.DCN inhibits tumor growth and lung metastasis of breast cancer via regulating wnt/ß-catenin, vascular endothelial growth factor (VEGF), and Met pathways, and modulating the antitumor inflammatory and immune responses. Considering that i.v. delivery was much more effective in preventing lung metastasis, systemic delivery of rAd.DCN might be a promising strategy to treat breast cancer lung metastasis.

Decorin-Modified Umbilical Cord Mesenchymal Stem Cells (MSCs) Attenuate Radiation-Induced Lung Injuries via Regulating Inflammation, Fibrotic Factors, and Immune Responses.

PURPOSE: To evaluate the therapeutic effects of decorin (DCN)-modified mesenchymal stem cells (MSCs) on radiation-induced lung injuries (RILIs) and to clarify the underlying mechanisms. METHODS AND MATERIALS: Umbilical cord-derived mesenchymal stem cells (MSCs) were modified with Ad(E1-).DCN to generate DCN-expressing MSCs (DCN-modified MSCs [MSCs.DCN]). In an experimental mouse model of RILI, MSCs.DCN and MSCs.Null [MSCs modified with Ad(E1-).Null] were intravenously engrafted at 6 hours or 28 days after irradiation. The therapeutic effects on lung inflammation and fibrosis were evaluated by histopathologic analysis at 28 days and 3 months after irradiation. Inflammatory cytokines and chemokines were analyzed in both sera and lung tissues, and subtypes of T lymphocytes including regulatory T cells (Tregs) were analyzed in the peripheral blood and spleen. RESULTS: Both MSC treatments could alleviate histopathologic injuries by reducing lymphocyte infiltration, decreasing apoptosis, increasing proliferation of epithelial cells, and inhibiting fibrosis in the later phase. However, treatment with MSCs.DCN resulted in much more impressive therapeutic effects. Moreover, we discovered that MSC treatment reduced the expression of chemokines and inflammatory cytokines and increased the expression of anti-inflammatory cytokines in both the peripheral blood and local pulmonary tissues. An important finding was that MSCs.DCN were much more effective in inducing interferon-γ expression, inhibiting collagen type III α1 expression in pulmonary tissues, and decreasing the proportion of Tregs. Furthermore, our data suggested that treatment during the acute phase (6 hours) after irradiation evoked much stronger responses both in attenuating inflammation and in inhibiting fibrosis than in the later phase (28 days). CONCLUSIONS: MSCs.DCN could attenuate acute inflammation after irradiation and significantly inhibit later fibrosis. Likewise, DCN enhanced the functions of MSCs by targeting profibrotic factors and Tregs.

Hepatocyte Growth Factor Gene Therapy for Ischemic Diseases.

Stem cells and gene therapy have become promising strategies for treating ischemic diseases and regenerating tissue. Hepatocyte growth factor (HGF) is an angiogenic growth factor with multiple functions, including promoting angiogenesis, regulating inflammation, inhibiting fibrosis, and activating tissue regeneration. Numerous preclinical experiments and clinical trials have demonstrated the feasibility and efficacy of HGF gene therapy in the treatment of ischemic diseases and tissue regeneration. This review summarizes the current advances of therapeutic angiogenesis using HGF gene transfer and modified stem cells. The physiological roles of HGF in angiogenesis and tissue regeneration are revisited. The current advances of clinical trials of plasmid and adenovirus HGF in the treatment of critical limb ischemia and coronary heart disease in China are introduced. Furthermore, valuable insight is provided into the prospective future of novel regenerative strategies using HGF-modified mesenchymal stem cells. HGF gene therapy is presented as a promising therapeutic approach in the treatment of ischemic diseases and regenerative medicine.

Improvement Effect of Water-Based Organic Polymer on the Strength Properties of Fiber Glass Reinforced Sand.

The mechanical properties of sandy soil can be effectively improved by the incorporation of water-based polymer and glass fibers. In order to study the reinforcement effects of a type of water-based organic polymer and fiber glass on sand, three strength tests (unconfined compression test, direct shear test and tensile test) and scanning electron microscopy were carried out. A series of polymer content, fiber content and dry density were selected for the tests. The results revealed that the composite reinforcement of water-based organic polymer and fiber glass can improve the strength. With an increase in polymer content and fiber content, the unconfined compression strength, the cohesion, and the tensile strength increase. The internal friction angles maintain a relatively stable state. All three strength properties increase with an increase in dry density. The results can be considered as the reference for sand reinforced engineering.

Effect of Sisal Fiber and Polyurethane Admixture on the Strength and Mechanical Behavior of Sand.

One major problem related to sandy soil is its low shear strength and cohesion in engineering. Although much effort has been made to strengthen sand mass with satisfactory performances, most undertakings lack environmental considerations. Thus, a combination of natural fiber and macromolecule polymer material attempts to achieve both strength and eco-friendliness. In the present investigation, sisal fiber (SF) and water-based polyurethane (PU) were used to reinforce sand. A series of unconfined compression tests were carried out on sand specimens at different percentages of fiber contents (0.2%, 0.4%, 0.6%, and 0.8% by weight of dry sand) and polymer contents (1%, 2%, 3%, and 4% by weight of dry sand). The results showed within our test range that the unconfined compressive strength (UCS) as well as post-peak strength of specimens increase with fiber and polymer contents. The inclusion of fiber and polymer significantly improve the ductility of specimens. The effect of dry densities on UCS were studied with three proportions. It is found that a high dry density led to an increase of UCS due to an effective contact area increase. The interactions were studied by observation through scanning electron microscopy (SEM) images. The presence of water-based polyurethane has the potential to improve the interparticle cohesion of sand due to its unique network membrane structure. The fiber reinforcement benefit depends strongly on the friction, interlocking force, and bond strength at the interface.

Transplantation of Hepatocyte Growth Factor-Modified Dental Pulp Stem Cells Prevents Bone Loss in the Early Phase of Ovariectomy-Induced Osteoporosis.

Investigations based on mesenchymal stem cells (MSCs) for osteoporosis have attracted attention recently. MSCs can be derived from various tissues, such as bone marrow, adipose, umbilical cord, placenta, and dental pulp. Among these, dental pulp-derived MSCs (DPSCs) and hepatocyte growth factor (HGF)-modified DPSCs (DPSCs-HGF) highly express osteogenic-related genes and have stronger osteogenic differentiation capacities. DPSCs have more benefits in treating osteoporosis. The purpose of this study was to investigate the roles of HGF gene-modified DPSCs in bone regeneration using a mouse model of ovariectomy (OVX)-induced bone loss. The HGF and luciferase genes were transferred into human DPSCs using recombinant adenovirus. These transduced cells were assayed for distribution or bone regeneration assay by transplantation into an OVX-induced osteoporosis model. By using bioluminogenic imaging, it was determined that some DPSCs could survive for >1 month in vivo. The DPSCs were mainly distributed to the lung in the early stage and to the liver in the late stage of OVX osteoporosis after administration, but they were scarcely distributed to the bone. The homing efficiency of DPSCs is higher when administrated in the early stage of a mouse OVX model. Micro-computed tomography indicated that DPSCs-Null or DPSCs-HGF transplantation significantly reduces OVX-induced bone loss in the trabecular bone of the distal femur metaphysis, and DPSCs-HGF show a stronger capacity to reduce bone loss. The data suggest that systemic infusion of DPSCs-HGF is a potential therapeutic approach for OVX-induced bone loss, which might be mediated by paracrine mechanisms.

[MiR-486 Regulates the Glycometabolism of Hematopoietic Cells by Targeting Sirt1].

OBJECTIVE: To investigate the effect and mechanism of miR-486 on glycometabolism of hematopoietic cells. METHODS: qRT-PCR was applied to detect the expression of miR-486 or Sirt1 on TF-1 cells under hypoxia. Lentivirus was used to mediate the overexpression or inhibition of miR-486 on TF-1 cells and qRT-PCR was used to detect the expressions of Sirt1, glucose transporter 1(Glut1) and glucose transporter 4(Glut4). Lentivirus-mediated Sirt1-shRNA transduction was used to knockdown Sirt1 expression which was detected by qRT-PCR and Western blot. The expressions of Glut1 and Glut4 were determined by qRT-PCR. RESULTS: Hypoxia promoted the expression of miR-486 and inhibited the expression of Sirt1. MiR-486 overexpression could inhibit the expression of Sirt1 and promote the expressions of Glut1 and Glut4, whereas miR-486 silencing upregulated the sirt1 expression and inhibited the expressions of Glut1 and Glut4. And inhibition of Sirt1 expression increased the expressions of Glut1 and Glut4. CONCLUSION: MiR-486 can regulate the glycometabolism of hematopoietic cells by targeting Sirt1.

New insight into mitochondrial changes in vascular endothelial cells irradiated by gamma ray.

PURPOSE: To investigate alterations of mitochondria in irradiated endothelial cells to further elucidate the mechanism underlying radiation-induced heart disease. MATERIALS AND METHODS: Experiments were performed using human umbilical vein endothelial cells (HUVECs). HUVECs were irradiated with single gamma ray dose of 0, 5, 10 and 20 Gy, respectively. Apoptosis was assessed by flow cytometry at 24, 48 and 72 h post-irradiation, respectively. The intracellular reactive oxygen species (ROS) was measured with 2',7'-dichlorofluorescein-diacetate (DCFH-DA) at 24 h post-irradiation. Mitochondrial membrane potential (ΔΨm) by JC-1 and the opening of mitochondrial permeability transition pore (mPTP) by a calcein-cobalt quenching method were detected at 24 h post-irradiation in order to measure changes of mitochondria induced by gamma ray irradiation. RESULTS: Gamma ray irradiation increased HUVECs apoptosis in a dose-dependent and time-dependent manner. Irradiation also promoted ROS production in HUVECs in a dose-dependent manner. At 24 h post-irradiation, the results showed that irradiation decreases ΔΨm, however, paradoxically, flow cytometry showed green fluorescence instensity higher in irradiated HUVECs than in control HUVECs in an irradiation dose-dependent manner which indicated gamma ray irradiation inhibited mPTP opening in HUVECs. CONCLUSIONS: Gamma ray irradiation induces apoptosis and ROS production of endothelial cells, and decreases ΔΨm meanwhile contradictorily inhibiting the opening of mPTP.

Exosomal miR-486 regulates hypoxia-induced erythroid differentiation of erythroleukemia cells through targeting Sirt1.

MicroRNAs (miRNAs) regulate the hypoxia-induced erythroid differentiation of hematopoietic cells. In this study, we identified that miR-486 was a rapid response miRNA to hypoxia in erythroleukemia TF-1 cells. Hypoxia exposure increased both intracellular and miR-486 levels of TF-1 cells. Ectopic miR-486 expression enhanced the growth and erythroid differentiation of TF-1 cells, whereas miR-486 inhibition suppressed their growth and erythroid differentiation. Treatment of TF-1 and cord blood CD34+ cells with exogenous containing miR-486 resulted in an increase of intracellular miR-486 level and enhanced erythroid differentiation. Furthermore, we identified that Sirt1 is a miR-486 target gene which modulates hypoxia-induced erythroid differentiation of TF-1 cells. Thus we identified a novel miRNA regulatory network that contributes to hypoxia-induced erythroid differentiation of hematopoietic cells.