OBJECTIVETo investigate the expression and the distribution of human beta defensin (hBD)-4 in healthy gingiva.

METHODSHealthy gingival specimens were collected. The expression of hBD-4 peptides in 18 gingival specimens were detected by immunohistochemistry. The hBD-4 mRNA were determined in freshly isolated gingival tissue by real time reverse transcription-polymerase chain reaction (real time RT-PCR) in 30 gingival specimens.

RESULTSIn 18 gingival specimens, hBD-4 peptides were expressed in 13 gingival specimens. In 30 gingival specimens, hBD-4 were detected in 4 gingival specimens by real time RT-PCR.

CONCLUSIONThe distribution and the expression levels of hBD-4 are different in healthy gingiva. This result may suggest that the hBD-4 play a role in maintaining the periodontal health.

There are at least three conserved protein folds shared by ion channel-targeted neurotoxins and antimicrobial defensins, including cysteine-stabilized α-helix and β-sheet fold (CSαβ), inhibitor cystine knot fold (ICK) and β-defensin fold (BDF). Based on a combined data of sequences, structures and functions, it has been proposed that these neurotoxins could originate from related ancient antimicrobial defensins by neofunctionalization. This provides an ideal system to study how a novel function emerged from a conserved structural scaffold during evolution. The elucidation of functional novelty of proteins not only has great significance in evolutionary biology but also will be helpful in guiding rational molecular design. This review describes recent progresses in origin of neurotoxins, focusing on the three conserved protein scaffolds.
Defensins ; chemistry ; Evolution, Molecular ; Neurotoxins ; chemistry ; Protein Structure, Secondary

BACKGROUND AND OBJECTIVES: It is believed that the innate immunity plays a critical role in protecting the tubotympanum from being infected because the middle ear cavity is normally sterile despite of a paucity of immune cells. Among known antibacterial molecules, defensins have been shown to contribute significantly to innate immunity. However, it is still unclear whether or not beta defensins are expressed in human middle ear mucosa. MATERIALS AND METHOD: Immunolabeling and RT-PCR were performed with the mucosal specimen from normal subjects and otitis media patients, respectively. Expression of beta defensin 2 mRNA was compared between the control group and experimental group that was treated by inflammatory stimuli in the animal models using RT-PCR. RESULTS: beta defensin 1 was expressed in both normal and inflamed middle ear mucosa of human, but beta defensin 2 and 3 were found only in the inflamed mucosa. The expression of beta defensin 2 mRNA was up-regulated when the interleukin-1alpha (IL-1alpha) or lipopolysaccharide (LPS) was treated in the middle ear mucosa of the experimental animals. CONCLUSION: We could show that beta defensins are expressed in the human middle ear mucosa and that beta defensin 2 is up-regulated by the inflammatory stimuli, IL-1alpha or LPS.
Animals ; beta-Defensins* ; Defensins ; Ear, Middle* ; Humans* ; Immunity, Innate ; Interleukin-1alpha ; Models, Animal ; Mucous Membrane* ; Otitis Media ; RNA, Messenger

PURPOSE: Defensins are important components of innate immune system. These peptides have antimicrobial activity against a wise variety of pathogens that associated with burn wound infection. In particular, human beta-defensins are expressed in normal epidermal region and showed differential expression of some skin disease. We investigated that expression of human beta-defensin by in vitro and ex-vivo by thermal condition. METHODS: To investigate the expression of human beta-defensins in acute burn condition, we cultured keratinocytes and used to rat's skin at this experiment. After thermal condition, we showed the expression of beta-defensins-2 (hBD-2), -3 (hBD-3), keratins, keratinocyte differentiation and junction protein levels by RT-PCR and immunohistochemistry (IHC). RESULTS: HBD-2 & involucrin were down-regulated from 1 hr to 8 hrs in mRNA level. But others were not changed in mRNA level. In protein level, hBD-3 was decreased but pan-cytokeratin and beta-catenin were not changed. CONCLUSION: HBD-2 was down-regulated in thermal injury. Because thermal injury could induce the influence of keratinocyte differentiation and the decrease of skin protection ability. Our results suggested that human beta-defensins plays an important role in protection by several injury.
beta Catenin ; beta-Defensins ; Burns ; Defensins ; Humans ; Immune System ; Immunohistochemistry ; Keratinocytes ; Keratins ; Peptides ; Protein Precursors ; RNA, Messenger ; Skin ; Skin Diseases ; Wound Infection

OBJECTIVETo investigate the expression of human beta-defensin-2 (HBD-2) in laryngeal squamous cell carcinoma (LSCC), and reveal the immune significance of HBD-2 in LSCC.

METHODSThe expression of HBD-2 and the infiltration of CD1a(+) dendritic cells were verified by immunohistochemistry strept actividin-biotin complex (SABC) method in thirty-four cases of LSCC's paraffin sections, and the expression of HBD-2 mRNA was detected in eighteen cases of postoperative tumor specimens and five cases of normal paracarcinoma tissue using cDNA probe by in situ hybridization. Based on the type and characteristic of datas, SPSS13.0 program package was used for statistical calculation.

RESULTS(1) The difference of expression of HBD-2 was significant among the grades of malignant cell differentiation (F = 6.809, P < 0.05), the expression of HBD-2 in well differentiated group was significantly increased compared with moderately and poorly differentiated group (P < 0.05), there wasn't significant difference with the clinical type, T status and lymphatic metastasis in the expression of HBD-2. (2) The difference of expression of HBD-2 mRNA among different grades of malignant cell differentiation was significant (F = 16.391, P < 0.05), less or no positive signal was observed in poorly differentiated group. (3) The infiltration of CD1a(+) dendritic cells had positive correlation with the expression of HBD-2 (r = 0.343, P < 0.05).

CONCLUSIONSThe expression of HBD-2 was related to the grade of malignant cell differentiation in LSCC, which was regulated at the level of transcription and translation. HBD-2 might play a role in anti-tumor immunity by chemo-attractiving and activating of immature dendritic cells.

OBJECTIVETo investigate the expression characteristics of human beta-defensin-2 (HBD-2) mRNA and protein in salivary gland benign and malignant tumor tissues, as well as in salivary gland inflammation.

METHODSThe expression of HBD-2 in salivary gland benign tumor, salivary gland cancer, inflammation tissues and normal salivary gland tissues were detected by polymerase chain reaction (PCR), real-time polymerase chain reaction (Real-Time PCR) and immunohistochemical. The differences expression of HBD-2 mRNA and protein were analyzed.

RESULTSRT-PCR results showed that HBD-2 mRNA expression in salivary gland benign tumors, salivary gland cancer, and inflammation tissues was 6.468-, 0.334-, and 10.563-fold higher than that in normal tissues, respectively (P < 0.05). HBD-2 was expressed in the nuclei of these organs and malignant tissues.

CONCLUSIONHBD-2 mRNA and protein expressions are significantly increased in salivary gland benign tumor tissues and inflammation tissues compared with those in normal salivary gland tissues, but are significantly decreased in salivary gland cancer. The protein nuclear transfer in salivary gland cancer tissues is also significantly increased.

Antimicrobial peptides (AMPs) are small molecules produced by a myriad of cells and play important roles not only in protecting against infections and sustaining skin barrier homeostasis but also in contributing to immune dysregulation under pathological conditions. Recently, increasing evidence has indicated that AMPs, including cathelicidin (LL-37), human β-defensins, S100 proteins, lipocalin 2, and RNase 7, are highly expressed in psoriatic skin lesions. These peptides broadly regulate immunity by interacting with various immune cells and linking innate and adaptive immune responses during the progression of psoriasis. In this review, we summarize the recent findings regarding AMPs in the pathogenesis of psoriasis with a main focus on their immunomodulatory abilities.
Adaptive Immunity ; Humans ; Immunity, Innate ; Pore Forming Cytotoxic Proteins ; Psoriasis ; Skin Diseases ; beta-Defensins

Defensins are endogenous cationic antimicrobial peptides rich in arginine and cysteine residues. They are important immune factors resisting pathogenic bacteria infection for mollusks. The 43 amino acid residues near the carboxyl terminal for Crassostrea gigas defensin (CgD) form its mature peptide region, responsible for the biological activity of CgD. First, two target genes, CgDH⁺ (with 6×His-tag at 3' end) and CgDH- (without 6×His-tag at 3' end) were separated and amplified by RT-PCR with specific primers from Crassostrea gigas mantle. These two target genes were ligated to the expression vector pPICZαA to construct recombinant expression vectors, pPICZαA-CgDH⁺ and pPICZαA-CgDH-, which were transformed into competent Pichia pastoris X-33 cells by electroporation respectively. The recombinant target proteins, CgDH⁺ and CgDH-, were induced for 72 h with 1% methanol at 29 °C and 250 r/min. The recombinant CgDH⁺ (5.78 kDa) was purified by immobilized metal affinity chromatography (IMAC), and identified by MALDI-TOF-TOF analysis, demonstrating that it was the expected target protein. Based on the concentration of the purified product, the estimated yield of recombinant CgDH⁺ was 2.32 mg/L. Antimicrobial assay showed that the culture medium supernatant containing recombinant CgDH⁺ and recombinant CgDH-, respectively, had activities against Staphylococcus aureus and Pseudomonas aeruginosa, indicating that the existence of 6×His tag in the recombinant proteins do not affect their biological activities.
Animals ; Anti-Bacterial Agents ; Antimicrobial Cationic Peptides ; Crassostrea ; Defensins ; Pichia ; Recombinant Proteins

The aim of this study was to screen the active regions and transcription factor binding sites in the promoter of the CBD103 gene related to Arctic fox coat color, and to provide a basis for revealing the molecular genetic mechanism of CBD103 gene regulating the coat color formation. The 5'-flanking region fragment 2 123 bp of Arctic fox CBD103 gene was cloned, and 4 truncated promoter reporter vectors of different lengths were constructed. The promoter activity was detected by the dual-luciferase reporter assay system. Point mutations were performed on the 3 predicted specificity protein 1 (Sp1) transcription factor binding sites in the highest promoter active region, and 3 mutant vectors were constructed. The activity was then detected by the dual-luciferase reporter assay system. The results showed that the region 1 656 (-1 604/+51) had the highest activity in the 4 truncated promoters of different lengths, and the promoter activity of the three mutant vectors constructed in this region were significantly lower than that of the wild type (fragment 1 656). The region of -1 604 /+51 was the core promoter region of CBD103 gene in Arctic fox and -1 552/-1 564, -1 439/-1 454 and -329/-339 regions were positive regulatory regions. This study successfully obtained the core promoter region and positive regulation regions of the Arctic fox CBD103 gene, which laid a foundation for further study on the molecular genetic mechanism of this gene regulating Arctic fox coat color.
Animals ; Binding Sites ; Foxes ; Luciferases ; Promoter Regions, Genetic ; Sp1 Transcription Factor ; beta-Defensins

OBJECTIVES: To investigate the effect of icariin (ICA) on early β-defensin-2 and T cell subsets in rats after tracheotomy. METHODS: A total of 54 SPF male Sprague-Dawley rats were randomly divided into a normal control group (group A), a model group (group B), and a model+ICA treatment group (group C), with 18 rats in each group. A tracheotomy intubation model of the B and C group was prepared. After 6 h of surgery, ICA intervention was given to group C. Groups A and B were given the same amount of normal saline. Lung tissue, alveolar lavage fluid and peripheral blood were taken at 24 h, 72 h and 168 h, respectively. The expression of rat β-defensin-2 mRNA in lung tissue was detected by RT-PCR. The content of β-defensin-2 in alveolar lavage fluid and peripheral blood serum was detected by ELISA. The content of peripheral blood T cell subsets (CD3, CD4, CD8) was detected by flow cytometry, and the ratio of CD4/CD8 was calculated. RESULTS: After tracheotomy, the levels of β-defensin-2 mRNA and β-defensin-2 in lung tissue from the group B were increased significantly at 24 h, then they were decreased gradually, and decreased most significantly at 168 h (<0.05). The content of β-defensin-2 in peripheral blood of group B decreased gradually, and the content of β-defensin-2 in 168 h was significantly lower than that in 24 h (<0.05), but there was no significant difference between group B and group A (>0.05). The level of CD3 T cells in peripheral blood was significantly lower than that in the group A (<0.05), but their was no significant difference in CD4 and CD8 T cells compared with group A (>0.05). After ICA intervention in group C: lung tissue, alveolar lavage fluid, peripheral blood serum β-defensin-2 content, and peripheral blood CD3 and CD4 T cell levels were gradually increased, significantly higher than those in the group B (<0.05). CD8 T cell level was significantly lower than that in the group A at 24 h (<0.05), the CD4/CD8 ratio was significantly higher at 168 h than those in the group A or B (both <0.01). CONCLUSIONS ICA can improve the early lung immune function in rats with tracheotomy, which might be related to up-regulation of β-defensin-2 in lung tissue and alveolar lavage fluid, concomitant with increases in CD3 and CD4 T cells and CD4/CD8 ratio in peripheral blood while reduction in CD8 cells.
Animals ; Flavonoids ; Male ; Rats ; Rats, Sprague-Dawley ; T-Lymphocyte Subsets ; Tracheotomy ; beta-Defensins