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Background: Antimicrobial peptides (AMPs) play important roles in the innate immune system of all life forms and recently have been characterized as multifunctional peptides that have a variety of biological roles such as anticancer agents. However, detailed mechanism of antimicrobial peptides on cancer cells is still largely unknown.Methods: miRNA array and real-time qPCR were performed to reveal the behavior of miRNA in colon cancer HCT116 cells during the growth suppression induced by the AMPs. Establishment of miR-663a over-expressing HCT116 cells was carried out for the evaluation of growth both in vitro and in vivo. To identify the molecular mechanisms, we used western blotting analysis.Results: miR-663a is upregulated by administration of the human cathelicidin AMP, LL-37, and its analogue peptide, FF/CAP18, in the colon cancer cell line HCT116. Over-expression of miR-663a caused anti-proliferative effects both in vitro and in vivo. We also provide evidence supporting the view that these effects are attributed to suppression of the expression of the chemokine receptor CXCR4, resulting in the abrogation of phosphorylation of Akt and cell cycle arrest in G2/M via p21 activation.Conclusions: This study contributes to the understanding of the AMPs' mediated anti-cancer mechanisms in colon cancer cells and highlights the possibility of using AMPs and miRNAs towards developing future strategies for cancer therapy. [ABSTRACT FROM AUTHOR]

Pigs throughout the world are afflicted with leptospirosis, causing serious economic losses and potential hazards to human health. Although it has been known that leptospiral lipopolysaccharide ( L-LPS) is involved in an immunological reaction between an antigen and a host cell, little is known about how the immune system of pigs can respond to L-LPS. Here, we stimulated pig fibroblasts by L-LPS and then quantitatively measured gene and protein expression levels of two toll-like receptors ( TLRs), TLR2 and TLR4, by real-time PCR and Western blotting. As a result, expression of TLR2 was found to be significantly up-regulated within 24 h after L-LPS stimulation whereas induction of TLR4 expression was relatively weak. We also revealed that of myeloid differentiation primary response gene 88 ( MyD88), interleukin 6 ( IL-6) and IL-8 gene expressions were markedly up-regulated by L-LPS stimulation. These results may suggest that the pig cell can activate TLR2 rather than TLR4 by L-LPS stimulation, thereby inducing expression of cytokines. [ABSTRACT FROM AUTHOR]

The cathelicidin family is one of the several families of antimicrobial peptides ( AMPs). A bovine myeloid antimicrobial peptide ( BMAP-28) belongs to this family. Recently, the emergence of drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus ( MRSA) has become a big problem. AMPs are expected to be leading compounds of new antibiotics against drug-resistant bacteria. In this study, we focused on the activity of BMAP-28 against bacterial cell surfaces. First, we observed morphological change of MRSA caused by BMAP-28 using a scanning probe microscope. We also studied activities of BMAP-28 against adherence of S. aureus to fibronectin, collagen type I, collagen type IV. We confirmed whether BMAP-28 can bind to lipoteichoic acid ( LTA) of S. aureus. BMAP-28 was indicated as damaging the cell surface of MRSA. In a particular range of concentrations, BMAP-28 promoted adherence of S. aureus against fibronectin and collagens. It was revealed that BMAP-28 and LTA of S. aureus bound with each other. Our study showed the potential of BMAP-28 which can damage MRSA and interact with LTA of S. aureus but promote its adherence in some concentrations. This study provides new points of which to take notice when we use AMPs as medicines. [ABSTRACT FROM AUTHOR]

A bovine myeloid antimicrobial peptide antimicrobial peptide ( BMAP-28) is a member of the cathelicidin family and acts as a component of innate immunity. There are few reports of susceptibility difference of methicillin-resistant Staphylococcus aureus ( MRSA) and susceptible strains ( MSSA) against BMAP-28. This study aims to clarify how a few amino acid substitutions of BMAP-28 are related to its antimicrobial activity using four analog peptides of BMAP-28. We also compared cellular fatty acid components of MSSA and MRSA using gas chromatography. We found that a few amino acid substitutions of BMAP-28 do not change antimicrobial activity. It was also revealed that the percentage of cis-11-eicosenoic acid in total detected fatty acids of MRSA was significantly higher than that of MSSA. In addition, the percentage of palmitic acid in total detected fatty acids of MRSA tended to be lower than that of MSSA. Our results will provide new information to deal with the question of differences in bacterial susceptibility against BMAP-28. [ABSTRACT FROM AUTHOR]

In this study, retinal whole-mount specimens were prepared and stained with 0.1% cresyl violet for the ganglion cell study in the Ostrich (Struthio camelus). The total number, distribution, and size of these cells were determined in different retinal regions. The mean total number of ganglion cells (three retinas) was 1 435 052 with an average density of 652 cells/mm2. The temporo – nasal area of the retina with high cell density were identified with the peak of 7525 cells/mm2 in the central area. The size of most ganglion cells ranged from 113–403 µm2, with smaller cells predominating along the temporo-nasal streak above the optic disc and larger cells comprising more of the peripheral regions. The average thickness of the retina was 196 µm. The central area was the thickest area (268.6 µm), whereas the peripheral area was the thinnest area. Thus, the specialization of ganglion cell densities, their sizes and the thickness of the retina support the notion that the conduction of visual information towards the brain from all regions of the retina is not uniform, and suggests that the temporo – nasal streak is the fine quality area for vision in ostriches. [ABSTRACT FROM AUTHOR]

Leptospiral lipopolysaccharide (L-LPS) has shown potency in activating toll-like receptor 2 (TLR2) in pig fibroblasts (PEFs_NCC1), and causes the expression of proinflammatory cytokines. However, the stimulation by L-LPS was weak eliciting the function of TLR2 sufficiently in pig innate immunity responses during Leptospira infection. In this study, the immune response of pig embryonic fibroblast cell line (PEFs_SV40) was investigated and was found to be the high immune response, thus TLR2 is the predominate receptor of L-LPS in pig cells. Further, we found a strategy using the antibody against L-LPS, to prevent L-LPS interaction with TLR2 in pig cells which could impact on immune activation.