OBJECTIVETo explore the role and potential mechanism of human α-defensin 1 (HNP-1) on low-density lipoprotein (LDL) oxidation ability of human endothelial cells (EVC304).

METHODSPost incubation with LDL for 3 h, the malondialdehyde (MDA) and protein carbonyl (PCO) were detected in untreated ECV304 (control) and in HNP-1 transfected ECV304 in the presence and absence of siRNA against HNP-1. Flow cytometry and fluorescence microscopy were used to detect the generation of oxygen free radical in the ECV304 which have been pretreated by LDL, LPS and HNP-1, respectively.

RESULTCompared with control group, MDA level was significantly increased in HNP-1 transfected [(4.21 ± 0.03) vs. (3.15 ± 0.02) nmol/mg · pro] or in HNP-1 stimulated ECV304 cells [(14.49 ± 1.10) vs. (9.47 ± 1.18) nmol/mg · pro], which could be significantly downregulated by siRNA [(3.76 ± 0.48) vs. (4.54 ± 0.28) nmol/mg·pro, all P < 0.05]. PCO was also significantly increased in HNP-1 transfected ECV304 cells. The levels of free radical were significantly increased in HNP-1 transfected or HNP-1 stimulated ECV304 cells.

CONCLUSIONHNP-1 can enhance the LDL oxidation ability of human endothelial cells via promoting the generation of free radicals.

Cell Line ; Endothelial Cells ; metabolism ; Humans ; Lipoproteins, LDL ; metabolism ; RNA, Small Interfering ; Transfection ; alpha-Defensins ; genetics ; metabolism

DNA fragment containing human alpha-defensin 5 mature peptide (mHD-5) coding sequence with biased codons of E. coli was amplified by PCR, which was subsequently cloned into the plasmid pMAL-p2x in order to create pMAL-p2x-mHD-5 expression vector. The plasmid pMAL-p2x-mHD-5 was transferred into engineered strain BL21(DE3) to express heterogeneous fusion protein (MBP-mHD-5). The soluble MBP-mHD-5 targeted protein inducible expressed by IPTG was accounted for about 30% under optimized conditions. The recombinant mHD-5 (rmHD-5) peptide was successfully purified through a separation process including affinity chromatography, Factor Xa digestion and ion exchange chromatography. The bioactivity of rmHD-5 was examined by bacteria-inhibition tests in liquid culture. The growth of E. coli ATCC25922 was dramatically suppressed with an inhibition rate of 90%, with the presence of 62.5 microg/mL rmHD-5 in the media. These results indicate that the strategy of soluble expression of fusion protein in E. coli can be a useful and practical way to produce bioactive defensins.
Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Humans ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; isolation & purification ; Solubility ; Transformation, Bacterial ; alpha-Defensins ; biosynthesis ; genetics

Copy number variation has been associated with various autoimmune diseases. We investigated the copy number (CN) of the DEFA1 gene encoding alpha-defensin-1 in samples from Korean individuals with Behcet's disease (BD) compared to healthy controls (HC). We recruited 55 BD patients and 35 HC. A duplex Taqman(R) real-time PCR assay was used to assess CN. Most samples (31.1%) had a CN of 5 with a mean CN of 5.4 +/- 0.2. There was no significant difference in the CN of the DEFA1 gene between BD patients and HC. A high DEFA1 gene CN was significantly associated with intestinal involvement in BD patients. Variable DEFA1 gene CNs were observed in both BD patients and HC and a high DEFA1 gene CN may be associated with susceptibility to intestinal involvement in BD.
Adult ; Behcet Syndrome/*complications/*genetics ; Female ; Gene Dosage ; Genetic Predisposition to Disease ; Genotype ; Humans ; Intestinal Diseases/*etiology/*genetics ; Male ; Middle Aged ; Real-Time Polymerase Chain Reaction ; alpha-Defensins/*genetics

OBJECTIVE: The aim of this study is to investigate the effects of inhibitor HNP1 transfection on proliferation and tumor growth of human nasopharyngeal carcinoma cell line HNE1. METHOD: HNE1 cells were transfected with HNP1 by liposome, and the cytotoxic effect was detected by MTT, In vivo tumor growth test was performed in nude mice inoculated with transfected HNE1 cells. The therapeutic effect of HNP1 was evaluated in the inoculated tumors, alpha-defensin 1 expression was detected in implanted tumor tissues by immunohistochemical stain. RESULT: HNP1 transfection significantly inhibited the proliferation of HNE1 cells. MTT assay confirmed cytotoxic effect. In vivo study showed tumor volume was significantly smaller in HNP1 transfection group than that in control group (P < 0.01). Immunohistochemical stain showed alpha-defensin expression was increased in HNP1 transfection group. CONCLUSION HNP1 transfection can inhibit the proliferation of HNE1 cells, as well as tumor growth.
Animals ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Nasopharyngeal Neoplasms ; genetics ; pathology ; Transfection ; Tumor Burden ; alpha-Defensins ; genetics

BACKGROUNDEndocervical epithelial cells play early roles in the defense of upper female genital tract to pathogens. Toll-like receptors (TLRs) and human defensins (HD) have recently been identified as fundamental components of the innate immune responses to bacterial pathogens. We aimed to use in vitro model of human primary endocervical epithelial cells (HPECs) to investigate their roles in innate immune response of the endocervix.

METHODSTLR4 expression and distribution in HPECs and endocervix were investigated by immunofluorescence (IF). Cultured HPECs were divided into lipopolysaccharide (LPS) group which were treated by LPS for 0, 24 and 48 hours, and control group without treatment. At each time point, the levels of HD5, IL-6 and TNF-alpha in supernants were determined by ELISA. TLR4 and HD5 expressions of cells were detected by Western blotting simultaneously. HD5 expression pattern was also compared between the HeLa cell line and HPECs.

RESULTSEndocervix tissue surface and HPECs expressed TLR4. After incubated with LPS, HPECs expressed significantly higher levels of TLR4 than control group, especially after 24 hours (P < 0.01), however decreased after 48 hours with a similar level of TLR4 expression compared with control group. LPS could upregulate the secretion of HD5, IL-6 and TNF-alpha in a time-dependent manner (24 hours: P < 0.05; 48 hours: P < 0.01, compared with control group). Intracellular HD5 expression levels decreased over time. HD5 expression patterns in HPECs were different from HeLa cell line.

CONCLUSIONSTo respond to LPS stimulation, HPECs may function in the mucosal immune defense through TLR4 activation and HD5 secretion. HPEC is considered a significant model for immunological study.

Blotting, Western ; Cells, Cultured ; Cervix Uteri ; cytology ; Enzyme-Linked Immunospot Assay ; Epithelial Cells ; metabolism ; Female ; Fluorescent Antibody Technique ; HeLa Cells ; Humans ; Interleukin-6 ; metabolism ; Toll-Like Receptor 4 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; alpha-Defensins ; genetics ; metabolism

Mammalian epithelia produce the various antimicrobial peptides against the bacterial or viral infection, thereby acting as the active immune modulators in the innate immunity. In this study, we examined the effects of the various proinflammatory cytokines or LPS on cell viability and antimicrobial beta-defensin gene expressions in human corneal epithelial cells. Results showed that the cytokines or LPS did not exert severe cytotoxic effects on the cells, and that beta-defensin 1 was constitutively expressed, while beta-defensin 2 was specifically induced by IL-1beta, supporting the idea that these cytokines or LPS involve the defense mechanism in the cornea. Furthermore, the reporter and gel shift assay to define the induction mechanism of beta-defensin 2 by IL-1beta demonstrated that the most proximal NF-kB site on the promoter region of beta-defensin 2 was not critical for the process. Data obtained from the normal or patients with the varying ocular diseases showed that our in vitro results were relevant in the clinical settings. Our results clearly demonstrated that beta-defensin 1 and 2 are important antimicrobial peptides in the corneal tissues, and that the mechanistic induction process of beta-defensin 2 by IL-1beta is not solely dependent on proximal NF-kB site activation, thus suggesting that the long distal portion of the promoter is needed for the full responsiveness toward IL-1beta.
Binding, Competitive ; Cell Survival ; Cells, Cultured ; Corneal Diseases/metabolism ; Electrophoretic Mobility Shift Assay ; Epithelium, Corneal/drug effects/*immunology/metabolism ; Gene Expression ; Humans ; Interferon Type II/metabolism/pharmacology ; Interleukin-1/*pharmacology ; Lipopolysaccharides/metabolism/pharmacology ; NF-kappa B/metabolism ; Promoter Regions (Genetics)/drug effects/genetics ; Research Support, Non-U.S. Gov't ; Tumor Necrosis Factor-alpha/metabolism/pharmacology ; beta-Defensins/*biosynthesis/genetics/metabolism