BACKGROUND: Defensins are small (3.5~5 kDa) cationic antimicrobial peptides that have a broad spectrum of activity that includes gram-negative bacterias, yeasts and enveloped viruses. The defensins contain six cysteine residues forming three disulfide bridges depending on the spacing of the cysteine residues and the connectivity of the disulfide bridge, defensins are classified into two families, the alpha-defensins (HNP) and beta-defensins (HBD). Recently two human epithelial beta defensins, HBD-1 and HBD-2 have been identified. HBD-1 has been detected in a number of normal mucosal sites, but HBD-2 is highly restricted in its expression by inflammatory stimulations. we invesigated the expression of hunam beta defensin in human male urogenital organs. METHODS: Specimens of normal human male testis, epididymis, prostate, seminal vesicles, vas deferens, urethra, bladder, ureter, kidney, pyelonephritis, epididymitis, clear renal cell carcinoma and transitional cell carcinoma of bladder were obtained as discarded material from urological surgery. Each sample was stored at snap frozen in liquid nitrogen subsequent to RNA extraction. Reverse transcription polymerase chain reaction (RT-PCR) was used to semiquantitate HBD-1 and HBD-2 mRNA using the housekeeping gene beta-actin as an internal control. Southern blotting and sequencing showed HBD-1, 2 expressions in male urogenital organs. RESULTS: We checked the expression of HBD-1, 2 mRNA in all specimen of normal human male urogenital organ, pyelonephritis, epididymitis, clear renal cell carcinoma and transitional cell carcinoma of bladder by RT-PCR and southern blotting analysis. We checked the homolgy of HBD-1, 2 by bands sequencing. CONCLUSION: Our study indicated that the normal male urogenital organs, infection and neoplasm in male urogenital organs expresses antimicrobial peptides. These may play an important role in the prevention of infections by bacterias, antimicrobial effects in infection and anticancer effects in neoplasm of male urogenital organs. These natural endogenous antibiotic peptides could be developed as novel therapeutic agents for fighting infections and neoplasms of the human male urogenital organs.
Actins ; alpha-Defensins ; Antimicrobial Cationic Peptides ; Bacteria ; beta-Defensins ; Blotting, Southern ; Carcinoma, Renal Cell ; Carcinoma, Transitional Cell ; Cysteine ; Defensins ; Epididymis ; Epididymitis ; Genes, Essential ; Gram-Negative Bacteria ; Humans* ; Kidney ; Male* ; Nitrogen ; Peptides ; Polymerase Chain Reaction ; Prostate ; Pyelonephritis ; Reverse Transcription ; RNA ; RNA, Messenger ; Seminal Vesicles ; Testis ; Ureter ; Urethra ; Urinary Bladder ; Vas Deferens ; Yeasts

<b>BACKGROUNDb>Antimicrobial peptides, including cathelicidin LL-37, human beta defensin (HBD)-2, and HBD-3, are important elements of the innate immune response and involved in modulation of the adaptive immunity, and they also play an important role in cutaneous defense against Mycobacterium tuberculosis.

<b>METHODSb>The fresh skin tissues and paraffin-embedded biopsy samples from three cutaneous tuberculosis, two tuberculids, and ten healthy individuals were collected. The expressions of LL-37, HBD-2, and HBD-3 mRNA in the lesions of three cutaneous tuberculosis and two tuberculids were detected by quantitative real-time polymerase chain reaction; the protein expressions were detected by immunohistochemistry and Western blotting methods.

<b>RESULTSb>The expressions of LL-37 mRNA and protein in the lesions of cutaneous tuberculosis and tuberculids were similar to that of normal skin. The expression of HBD-2 mRNA had an increasing trend in the lesions of cutaneous tuberculosis and tuberculids compared with that of normal skin; however, the expression of HBD-2 protein in the lesions of cutaneous tuberculosis had a decreasing trend compared with that of normal skin, and the expression of HBD-2 protein in the lesions of tuberculids was similar to that of normal skin. The expressions of HBD-3 mRNA and protein in lesions of cutaneous tuberculosis and tuberculids were similar to that of normal skin.

<b>CONCLUSIONSb>Our study indicated that the expression of HBD-2 and HBD-3 mRNA and protein in lesions of cutaneous tuberculosis may be not consistent with that of tuberculids. However, an inherent limitation of the present study was that the sample size was small, and the roles and regulation mechanisms of LL-37, HBD-2, and HBD-3 in cutaneous tuberculosis and tuberculids need to be further investigated.

Adult ; Aged ; Antimicrobial Cationic Peptides ; genetics ; Female ; Humans ; Male ; Middle Aged ; RNA, Messenger ; analysis ; Tuberculosis, Cutaneous ; metabolism ; beta-Defensins ; genetics

To evaluate the association of Toll-like receptors (TLRs), antimicrobial peptides (AMPs) and vitamin D receptors (VDRs) in psoriasis, lesional (PP) and perilesional skin (PN) from psoriasis, atopic dermatitis (AD) patients and healthy controls (NN) were studied by immunohistochemistry. Compared with PN, AD and NN skin, dysregulated expression of TLRs, AMPs and VDR was detected in PP skin. Noteworthy, our results showed altered correlation between TLR2 and VDR expression in PP and PN skin. Human beta defensin 2 (HBD2) and cathelicidin (LL-37) expressions in the PP skin were higher in serum vitamin D sufficient (VDS) groups than serum vitamin D deficient (VDD) groups. Negative correlation was found between TLR2 and VDR expression in the PP skin of VDD groups. However, positive correlation was noted in the PP skin of VDS groups. Based on the present results, therapies targeting the activity of TLRs, AMPs and vitamin D, including modulation of the TLR-VDR pathways, might provide new therapeutic approaches to the psoriasis and other inflammatory skin diseases.
Anti-Infective Agents/*metabolism ; Antimicrobial Cationic Peptides/*metabolism ; Female ; Humans ; Male ; Psoriasis/*metabolism ; Receptors, Calcitriol/metabolism ; Toll-Like Receptors/*metabolism ; Vitamin D/*blood ; beta-Defensins/metabolism

The current strategy in treating multi-drug resistant gram-negative bacterial (MDR-GNB) infections is salvage therapy by using polymyxins. However, the beginning emergence of polymyxin resistance should enforce strict antimicrobial stewardship programs to preserve polymyxin efficacy. Knowledge of structural characteristics, pharmacodynamic, and pharmacokinetic profiles of polymyxins, as well as consideration of efficacy, safety, suitability, and cost, will help in the choice of the appropriate polymyxin for therapy. Polymyxin B is the recommended polymyxin for systemic use, while colistin is recommended for lower urinary tract infections, intraventricular, and intrathecal use. Either polymyxin can be used for hospital-acquired and ventilator-associated pneumonia. Combination therapy over monotherapy remains to be advantageous due to synergism and decreased resistance development. The choice of the second drug to be used should be based on full susceptibility, or if unavailable, a drug with the least minimum inhibitory concentration relative to the breakpoint set by the Clinical and Laboratory Standards Institute. Using the mnemonic ESCAPE can also guide physicians in their polymyxin prescription process: (1) Checking if the pathogen is Extensively resistant or multi-drug resistant; (2) checking the patient’s clinical status if compatible with Significant infection; (3) using Combination therapy; (4) ensuring Adequate dosing; (5) Proper preparation and administration of drug; and (6) keeping an Eye for response and adverse effects.
Polymyxin B ; Colistin ; Polymyxins

Hepcidin can regulate cell irons' efflux transport. The expression of hepcidin can be influenced by the body signals (such as serum ferritin and erythropoietin levels) as well as inflammation, hypoxia and other disease states. These stimulus activate the signaling pathway of BMP-the SMAD, the JAK-STAT and HIF1 through the liver parenchymal cell surface type I transmembrane glycoprotein of HFE, transferrin receptor 1, 2, hepcidin regulatory proteins, thereby changing the hepcidin gene transcription, regulating the expression levels of hepcidin. However, the molecular mechanism that regulate hepcidin expression is unclear. From the signal factors that affect hepcidin expression and signaling pathways involved in its expression, the latest research progress on regulatory mechanism of hepcidin are summarized.
Animals ; Antimicrobial Cationic Peptides ; metabolism ; Hepcidins ; Humans ; Membrane Proteins ; metabolism ; Signal Transduction

Antimicrobial Cationic Peptides ; biosynthesis ; Hepacivirus ; pathogenicity ; Hepcidins ; Iron ; metabolism ; Liver ; chemistry ; metabolism ; pathology

Hepcidin is a small cystein-rich cationic peptide produced mainly by the liver. It was initially isolated from human plasma and exhibited antimicrobial activity. Recently, several lines of evidence have suggested that hepcidin is a key regulator of iron metabolism at the whole body level and is relative to inflammation, infection, hypoxia and anemia. Hepcidin, is implicated in duodenal iron absorption and iron mobilization from reticuloendothelial macrophages. The major mechanism of hepcidin function seems to be the regulation of transmembrane iron transport. As both iron deficiency and iron excess are associated with cellular dysfunction, so hepcidin or hepcidin-related therapeutics could find a place in the treatment of various diseases such as hemochromatosis and anemia of chronic disease. To elucidate biological function of hepcidin further and use it for other research, it is necessary to produce enough hepcidin through DNA recombinant technique. As a highly successful system for the production of a variety of heterologous proteins, the methylotrophic Pichia pastoris system has the probability for a high level production of hepcidin. The subject of this paper is to summarize the regulation of hepcidin gene expression and the understanding of functions of hepcidin. At last, giving a prospect of production hepcidin by gene engineer.
Antimicrobial Cationic Peptides ; biosynthesis ; genetics ; physiology ; Hepcidins ; Humans ; Iron ; metabolism ; Protein Engineering ; methods

Anemia of chronic disease is normocytic and normochromic. One of the mechanisms is misbalance of iron metabolism. Hepcidin, a kind of protein secreted by liver is considered to be the hormone regulating iron metabolism. It binds to ferroportin and induces the latter one's internalization. Thus, iron transportation from iron storage cells to serum is reduced. Cytokines are elevated in chronic disease. They stimulate hepcidin expression in liver through JAK2/STAT3 pathway. As a result, iron absorption and reabsorption is blocked, which leads to the misbalance of iron metabolism in anemia of chronic disease. In this article, the hepcidin and its relation to iron metabolism and anemia in chronic disease are reviewed.
Anemia ; metabolism ; Antimicrobial Cationic Peptides ; metabolism ; Chronic Disease ; Hepcidins ; Humans ; Iron ; metabolism

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

To investigate whether LL-37 and human beta defensin-2 (hBD-2) is related to the patients with psoriasis seldom having skin infections and explore the role of the two peptides and CCR6 (the receptor of hBD-2) in the pathogenesis of psoriasis, the expression levels of mRNA of LL-37, hBD-2, and CCR6 in skin lesions of patients with psoriasis vulgaris were detected by using RT-PCR. The results showed that the mRNA expression levels of the two peptides and CCR6 in psoriatic lesions all increased compared with the normal skin (P<0.001). It was suggested that up-regulated expression of LL-37 and hBD-2 might be the main reason that result in the the skin of patients with psoriasis being seldom infected, and the two peptides and CCR6 might play crucial roles in the pathogenesis of psoriasis.
Adult ; Antimicrobial Cationic Peptides ; biosynthesis ; genetics ; Female ; Humans ; Male ; Middle Aged ; Psoriasis ; genetics ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, CCR6 ; Receptors, Chemokine ; biosynthesis ; genetics ; Up-Regulation ; beta-Defensins ; biosynthesis ; genetics