The effects of a biodegradable Mg-based alloy on the function of VSMCs via immunoregulation of macrophages through Mg-induced responses.

BACKGROUND: Restenosis is one of the worst side effects of percutaneous coronary intervention (PCI) due to neointima formation resulting from the excessive proliferation and migration of vascular smooth muscle cells (VSMCs) and continuous inflammation. Biodegradable Mg-based alloy is a promising candidate material because of its good mechanical properties and biocompatibility, and biodegradation of cardiovascular stents. Although studies have shown reduced neointima formation after Mg-based CVS implantation in vivo, these findings were inconsistent with in vitro studies, demonstrating magnesium-mediated promotion of the proliferation and migration of VSMCs. Given the vital role of activated macrophage-driven inflammation in neointima formation, along with the well-demonstrated crosstalk between macrophages and VSMCs, we investigated the interactions of a biodegradable Mg-Nd-Zn-Zr alloy (denoted JDBM), which is especially important for cardiovascular stents, with VSMCs via macrophages. METHODS: JDBM extracts and MgCl2 solutions were prepared to study their effect on macrophages. To study the effects of the JDBM extracts and MgCl2 solutions on the function of VSMCs via immunoregulation of macrophages, conditioned media (CM) obtained from macrophages was used to establish a VSMC-macrophage indirect coculture system. RESULTS: Our results showed that both JDBM extracts and MgCl2 solutions significantly attenuated the inflammatory response stimulated by lipopolysaccharide (LPS)-activated macrophages and converted macrophages into M2-type cells. In addition, JDBM extracts and MgCl2 solutions significantly decreased the expression of genes related to VSMC phenotypic switching, migration, and proliferation in macrophages. Furthermore, the proliferation, migration, and proinflammatory phenotypic switching of VSMCs were significantly inhibited when the cells were incubated with CMs from macrophages treated with LPS + extracts or LPS + MgCl2 solutions. CONCLUSIONS: Taken together, our results suggested that the magnesium in the JDBM extract could affect the functions of VSMCs through macrophage-mediated immunoregulation, inhibiting smooth muscle hyperproliferation to suppress restenosis after implantation of a biodegradable Mg-based stent.

Role of SOCS3 in enhanced acute-phase protein genes by neonatal macrophages in response to IL-6.

BACKGROUND: Interleukin 6 (IL-6) induce the inflammatory response directly related with the morbidity and mortality of neonatal. Here we aimed to explore the mechanism of IL-6 in neonatal inflammatory response by studying the IL-6/STAT3 signaling pathway. METHODS: Cord blood samples from health term neonatal and peripheral venous blood from health volunteers were collected. The monocytes of adults and cord blood were isolated and induced into macrophages. Then the macrophages were pretreated with or without MG132 before IL-6 stimulation. Proteins were analyzed by Western blot, mRNA by real time PCR and membrane molecule by flow cytometry. RESULTS: The acute phase protein gene expression in neonatal macrophages after stimulated with IL-6 were higher than that in adult. Significantly enhanced phosphorylation of STAT3 was seen in neonatal macrophages. Both mRNA and protein expression of SOCS3 in neonatal macrophages were lower than that in adult. After pretreated with MG132, the expression of SOCS3 protein was increased which lead to attenuate the STAT3 phosphorylation and APP gene expression. CONCLUSION: Neonatal exhibit an enhanced expression of downstream target genes and IL-6/STAT3 signal pathway which is related with the diminished SOCS3. This provides a new sight into inflammatory responses in neonatal.

Role of Zc3h12a in enhanced IL-6 production by newborn mononuclear cells in response to lipopolysaccharide.

BACKGROUND: The uncontrolled inflammatory response following infection is closely related to the morbidity and mortality of neonates. Interleukin 6 (IL-6) plays an important role in the pathogenesis and prognosis of this process. To better elucidate the secretion of IL-6 following infection in neonates, we investigated the IL-6 level and mechanism of IL-6/TLR4 signaling pathways. METHODS: We compared the IL-6, procalcitonin (PCT), and CRP levels between septic neonates and toddlers. In vitro cord blood samples from healthy term neonates and peripheral venous blood from healthy adult volunteers were collected. Protein expression was analyzed by Western blotting, mRNA expression by real-time PCR and membrane molecule expression by flow cytometry. RESULTS: The IL-6 concentrations were significantly higher in the neonate group than in the toddler group (p < 0.05). In the toddler group, the IL-6 concentrations were correlated positively with both PCT and CRP (PCT: r = 0.451, p = 0.001; CRP: r = 0.243, p = 0.023). In vitro, the secretion of IL-6 increased with the rising concentrations of LPS; at 1000 ng/ml LPS, IL-6 secretion from the monocytes of neonates was significantly higher than that of adults. There was a marked decreased level of MyD88 in neonate monocytes compared with that in adult monocytes. Additionally, the mRNA levels of Zc3h12a in neonate monocytes were significantly lower than those in adult monocytes following LPS stimulation. CONCLUSION: Neonates displayed enhanced IL-6 production after infection. Our study, for the first time, reported a significant decrease in the expression of Zc3h12a in neonates. Thus, Zc3h12a may be a key factor for the aberrant increase in IL-6 after neonate infection.

Clinical characteristics and genetic profiles of 174 patients with X-linked agammaglobulinemia: Report from Shanghai, China (2000-2015).

X-linked agammaglobulinemia (XLA) is a humoral primary immunodeficiency. XLA patients typically present with very low numbers of peripheral B cells and a profound deficiency of all immunoglobulin isotypes. Most XLA patients carry mutations in Bruton tyrosine kinase (BTK) gene.The genetic background and clinical features of 174 Chinese patients with XLA were investigated. The relationship between specific BTK gene mutations and severity of clinical manifestations was also examined. Mutations were graded from mild to severe based on structural and functional prediction through bioinformatics analysis.One hundred twenty-seven mutations were identified in 142 patients from 124 families, including 45 novel mutations and 82 recurrent mutations that were distributed over the entire BTK gene sequence. Variation in phenotypes was observed, and there was a tendency of association between genotype and age of disease onset.This report constitutes the largest group of patients with BTK mutations in China. A genotype-phenotype correlation was observed in this study. Early diagnosis of congenital agammaglobulinemia should be based on clinical symptoms, family history, and molecular analysis of the BTK gene.

Effects of tumor microenviromental factors on VEGF expression.

The expression of vascular endothelial growth factor (VEGF) is regulated by microenvironmental factors within the tumors, such as hypoxia, free radicals, pH imbalance and nutrient deficiency. The purpose of this study was to observe VEGF activity in tumor cells under different stress conditions. A plasmid was generated, consisting of green fluorescent protein (GFP) fused to a 1,217-bp sequence, which was located downstream and upstream of the transcriptional start site of VEGF, respectively. The plasmid was stably transfected into 4T1 mouse breast carcinoma cells. Cells were cultured in a medium with nitric oxide (NO) donor sodium nitroprusside (SNP), hypoxia-mimetic agent deferoxamine mesylate (DFX), H2O2, absence of serum and lowered or elevated pH, or were heat-shocked, followed by measurement of VEGF activity by reverse transcription polymerase chain reaction (RT-PCR) and ELISA. Hypoxia, SNP and H2O2 led to increments of VEGF mRNA and protein expression, as well as of GFP expression. The pH alterations, serum deprivation and heat shock reduced VEGF mRNA expression, but had little effect on GFP expression. The results demonstrated that VEGF expression may be influenced by a number of microenvironmental factors and these factors may play important roles in regulating VEGF expression during tumorigenesis.

Low dosage 5-fluorouracil increases the transfection efficiency of Ad/VEGF-A in mouse lung carcinoma cell line LA795 and inhibits tumor growth.

BACKGROUND AND OBJECTIVE: Adenovirus vectors were widely used in gene therapy for tumors. We used adenovirus vector to transfer small interfering RNA (siRNA) against vascular epithelium growth factor A (VEGF-A) molecules to mouse lung adenoma LA795 cells and used low dose of chemotherapeutic drugs to further elevate the infection efficiency of adenovirus vector in and therapeutic effect of RNAi on tumor cells. METHODS: LA795 cells were infected by Ad/EGFP and treated with different dosages of gemcitabin, epirubicin, cisplatin, or 5-fluorouracil (5-FU). Cells were observed under fluorescence microscope continuously using green fluorescent protein (GFP) as the reporter gene. The percentage of GFP-positive cells and fluorescent intensity were tested by flow cytometry to determine optimum concentrations of drugs. Ad/siVEGF-A containing VEGF-A siRNA was constructed. Real-time PCR and ELISA were applied to measure the expression level of VEGF-A after LA795 cells were infected by Ad/siVEGF-A and treated with 5-FU. The combination of Ad/siVEGF-A and 5-FU was also applied in treating subcutaneous tumor in mice. RESULTS: Low dose of 5-FU elevated the Ad/EGFP infection in LA795 cells significantly, and also enhanced the effect of Ad/siVEGF-A in down-regulating VEGF-A mRNA and protein levels in tumor cells. When used in tumor in vivo, the combination strategy repressed tumor growth effectively. CONCLUSION: Low dose of 5-FU can enhance the capability of adenovirus infecting tumor cells and promote the efficiency of gene therapy by adenovirus.

Potent anti-tumor activity of telomerase-dependent and HSV-TK armed oncolytic adenovirus for non-small cell lung cancer in vitro and in vivo.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the leading cause of cancer related mortality, any improvements in therapeutic strategies are urgently required. In this study we generated a novel 'suicide gene' armed oncolytic adenoviral vector and investigated its antitumor effect both in vitro and in vivo. METHODS: Since the up-regulated expression of human telomerase reverse transcriptase (hTERT) is a hallmark of alltypes of NSCLC, we chose hTERT promoter to transcriptionally control E1A gene expression to obtain adenoviral replication in NSCLC. In order to further enhance anti-tumor effect of this oncolytic adenoviral vector, we inserted a 'suicide gene' i.e. Herpes Simplex Virus Thymidine Kinase (HSV-TK) into oncolytic adenoviral vector to engineer a novel armed oncolytic adenoviral vector 'Ad.hTERT-E1A-TK'. RESULTS: Ad.hTERT-E1A-TK efficiently killed different types of tumor cells including two types of NSCLC cells in vitro, causing no damage to normal primary fibroblasts. Furthermore, Ad.hTERT-E1A-TK infection combined with administration of prodrug gancyclovir (GCV) resulted in more potent cytotoxicity on NSCLC cells, and synergistically suppressed human NSCLC tumor growth in nude mice. CONCLUSION: The results from this study showed that Ad.hTERT-E1A-TK/GCV could be a potent but safe anti-tumor strategy for NSCLC biotherapy.

siRNA-mediated knockdown of VEGF-A, VEGF-C and VEGFR-3 suppresses the growth and metastasis of mouse bladder carcinoma in vivo.

The growth of solid tumors is highly dependent on the formation of new blood and/or lymph vessels. Furthermore, metastases often disperse via newly formed blood or lymphatic vessels within the tumor, particularly in the case of epithelium-derived tumors. Since vascular endothelial growth factor (VEGF) signaling plays a vital role in angiogenesis and lymphangiogenesis, we used the small interfering RNA (siRNA) approach to selectively down-regulate VEGF-A, VEGF-C or VEGF receptor 3 (VEGFR-3) expression in bladder transitional carcinoma cells derived from T739 mice in an attempt to suppress tumor growth and metastasis in vivo. The synthetic siRNA was introduced into the tumor tissues by in vivo electroporation. The knockdown of VEGF-A, VEGF-C and VEGFR-3 expression significantly delayed tumor growth and reduced tumor metastasis compared to the negative controls. Thus, electroporation-mediated siRNA delivery to block the VEGF signaling pathway may provide a novel approach for the treatment or prevention of solid tumor growth and metastasis.

[Enhanced transduction efficiency of adeno-associated virus on cancer cells with the help of low dose adenovirus].

OBJECTIVE: To investigate whether adeno-associated virus (AAV) could enhance its infection efficiency on cancer cells when combined with non-replicable adenovirus (Ad-null) in vitro as well as in vivo and to study its underlying mechanisms. METHODS: AAV2 particle was added into NCI-H460 tumor cell lines alone or in combination with different amount of adenovirus. 1 to 7 days after transduction, cells were observed and recorded with fluorescence microscope, the expression levels of report gene EGFP in tumor cells were examined by using flow cytometry and Western blotting, the expression of report genes luciferase was analyzed with luminometer to obtain the relative light units. After the establishment of tumor model, the nude mouse were administrated with AAV2 or AAV2 + Ad-null in tumors, and then tested their infection efficiency and expression levels with roperscientific bioluminescence tumor imaging system. RESULTS: The results obtained with the help of flow cytometry and luciferase assay suggested that the infection efficiency of AAV2 was enhanced significantly when combined with low dose Ad-null in vitro, the infection efficiency of AAV2 alone was 6.4% and it reached 55.2% when combined with 10 MOI Ad-null, Western blotting assay demonstrated that the protein expression level of reporter gene in tumor cells enhanced when combined with 10 MOI Ad-null compared with AAV2 infection alone, and the enhancement of reporter gene expression was observed in a concentration-dependent manner; real-time PCR analysis confirmed that Ad-null enhanced the mRNA level of AAV2-EGFP but not the copies of genomic DNA of AAV2-EGFP. Ad-null significantly augmented the infection efficiency when tested on NCI-H460 tumor model. With the help of Ad-null, the signal of luciferin in nude mouse was 4.5 times more than that of control. CONCLUSION: The infection efficiency of AAV was enhanced significantly when combined with low dose Ad-null in vitro and in vivo, and it offers basis for further study of gene therapy by AAV.

[Transduction efficacy of recombinant type 1 and type 2 adeno-associated virus in the retinal cells].

OBJECTIVE: To investigate the transduction and gene expression of the recombinant adeno-associated viruses (rAAV) of the serotypes 1 and 2 in the retinal cells. METHODS: rAAV vectors of type 1 and type 2 encoding EGFP were infected into the cultured retinal pigmentary epithelium (RPE) cells of the line CRL-2302 and primarily cultured retinal neural cells from normal SD rats, and primarily cultured RPE cells from an adult cornea donor. The cultured RPE cells transduced by rAAV2-EGFP or rAAV2/1-EGFP were harvested at the 7 th and 14 th day after infection to be detected by fluorescence-activated cell sorter. The onset of EGFP gene expression and EGFP positive rate were detected by flow cytometry and fluorescence microscopy. Then, rAAV2/1-EGFP and rAAV2-EGFP were injected into the subretinal spaces of 32 SD rats to investigate the onset of EGFP fluorescence and its distribution in the fundus in vivo via fluorescence stereoscope. HE staining and immunohistochemistry were used to observe the infected cell type and immune response in the retina. RESULTS: The percentage of EGFP positive cells and mean intensity of EGFP fluorescence in the cells transduced by rAAV2-EGFP 7 and 14 days after transduction were 13.50% +/- 1.70% and 15.60% +/- 0.82%, and 2.75 +/- 0.12 and 3.80 +/- 0.72 respectively; and the EGFP positive cells and mean intensity of EGFP fluorescence in the cells transduced by rAAV2/1-EGFP were 1.09% +/- 0.5% and 1.98% +/- 0.45%, and 1.12 +/- 0.09 and 1.75 +/- 0.2 respectively. The EGFP fluorescence area in the retina were (5389 +/- 211) microm(2), (9832 +/- 364) microm(2), (14 454 +/- 446) microm(2), (20 528 +/- 648) microm(2), and (20 264 +/- 683) microm(2) respectively 3, 7, 14, and 75 days, and 4 month after transduction by rAAV2-EGFP in vivo; In the rat retina transduced by rAAV2/1-EGFP, the EGFP fluorescence areas were (9666 +/- 348) microm(2), (12 160 +/- 439) microm(2), (19 794 +/- 621) microm(2), (26 172 +/- 923) microm(2), and (26 022 +/- 965) microm(2) respectively 3, 7, 14, and 75 days, and 4 month after infection. CONCLUSION: rAAV2 efficiently transduces retinal cells both in vitro and in vivo. rAAV2/1 is a more effective gene-transferring vector to be used in retinal cells in vivo than rAAV2.

[Inhibitation of tumor angiogenesis, growth and metastasis by blocking VEGF paracrine pathway].

Solid tumors require an adequate vascular supply to grow beyond a certain dimension. It is known that formation of new blood vessels in tumor is mediated by unbalanced expression of angiogenic factors and their inhibitors. Among the former, the vascular endothelial growth factor (VEGF) has been assumed prime candidacy as a major positive physiological effector. To investigate the role of VEGF in angiogenesis associated with development of breast cancer, a sense VEGF and an anti-sense VEGF expression plasmids were constructed, and then were introduced into a human breast carcinoma cell line, MCF-7, expressing middle level of endogenous VEGF. Anti-sense VEGF(121) transfected MCF-7 cells that expressed reduced constitutive levels of VEGF and showed the same growing potential as untransfected MCF-7 cells in vitro, but it showed longer latency, smaller tumor, slower growth and prolonged survival time compared to parental or sense VEGF(165) transfected MCF-7 cells in vivo. Moreover, the tumors derived from anti-sense VEGF(121) transfected MCF-7 cells characterized by minimal vascularization and extensive necrosis. Finally, mice with primary subcutaneous tumors treated with intratumoral administration of anti-sense VEGF, or the plasmid expressing extracellular domain of the Flk-1 VEGF receptor (sFlk-1) followed by electroporation, showed significant tumor suppression. These results suggest that VEGF plays a major angiogenic role in breast cancer and a strategy, which blocks the VEGF paracrine pathway, may provide a means to control tumor growth topically without the risk of systemic antiangiogenesis.