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Although naturally occurring membrane lytic antimicrobial peptides (AMPs) and their analogs hold enormous promise for antibiotics-resistant infectious disease therapies, significant challenges such as systemic toxicities, long peptide sequences, poor understanding of structure-activity relationships, and the potential for compromising innate host defense immunity have greatly limited their clinical applicability. To improve the clinical potential of AMPs, a facile approach is adopted to design a series of short synthetic β-sheet folding peptide amphiphiles comprised of short recurring (X1Y1X2Y2)n-NH2 sequences, where X1 and X2: hydrophobic residues (Val, Ile, Phe or Trp), Y1 and Y2: cationic residues (Arg or Lys), and n: number of repeat units; with systematic variations to the cationic and hydrophobic residues to obtain optimized AMP sequences bearing minimal resemblance to naturally occurring sequences. The designed β-sheet forming peptides exhibit broad spectrum antimicrobial activities against various clinically relevant microorganisms, including Gram-positive Staphylococcus epidermidis and Staphylococcus aureus, Gram-negative Escherichia coli and Pseudomonas aeruginosa, and yeast Candida albicans, with excellent selectivities for microbial membranes. Optimal synthetic peptides with n = 2 and n = 3 repeat units, i.e., (IRIK)2-NH2 and (IRVK)3-NH2, efficiently inhibit sessile biofilm bacteria growth leading to biomass reduction. Additionally, sequences with n = 3 repeat units effectively neutralize endotoxins while causing minimal cytotoxicities. Taken together, these findings clearly demonstrate that the rationally designed synthetic β-sheet folding peptides are highly selective, non-cytotoxic at antimicrobial levels and have tremendous potential for use as broad spectrum antimicrobial agents to overcome multidrug resistance in a wide range of localized, systemic, or external therapeutic applications. [ABSTRACT FROM AUTHOR]

Objective: To study the relationship between nitric oxide within cervical microenvironment and different HPV types as well as the effect of sodium nitroprusside (SNP), a nitric oxide donor, on the proliferation and apoptosis of cervical cancer cell lines., Methods: HPV typing test was assessed from 115 women by using high-risk HPV (HR-HPV) 21 typing test and the release of cervical nitric oxide (NO) was assessed as nitrate, nitrite in cervical fluid. Cervical NO was then compared between women showing different HPV types. Proliferation of Caski and HeLa cervical cells was determined by methyl thiazolyl tetrazolium (MTT) assay, cell apoptosis was detected by flow cytometry after 24 hours treated by different final concentration of SNP (0.125, 0.25, 0.5, 1.0 and 2.0 mmol/L, respectively). The expressions of HPV E6, E7 gene mRNA and p53 protein were detected by SYBR Green I quantitative real-time PCR and western blot., Results: (1) The cervical NO release of women with HR-HPV was higher compared to that in HPV negative women [(47.6±1.4) µmol/L vs (22.8±0.3) µmol/L; P<0.05]; but there was no statistical difference between low-risk HPV (LR-HPV) group [(24.1±1.2) µmol/L] and control group (P>0.05). (2) After 24 hours treated by different final concentration of SNP, the results shown that SNP could inhibited the proliferation and increased apoptosis rate in Caski and HeLa cells, in which the concentration of SNP≥1.0 mmol/L, there were significantly different (P<0.05), while when SNP≥2.0 mmol/L, the proliferation of cells inhibited seriously. Treated by SNP (1.0 mmol/L) 24 hours, the expressions of HPV18 E6, E7 mRNA in HeLa cells were reduced from 27.362±0.191, 22.962±0.053 to 19.181±0.360, 17.571±0.010 and the protein expression of p53 increased from 1.17±0.03 to 0.23±0.05, there were statistically significant differences between adding SNP group and the control group (P<0.05); but there were no statistically significant differences in HPV16 E6, E7 mRNA and that of p53 in Caski cells (P>0.05)., Conclusions: The presence of HR-HPV is associated with an increased release of NO in the human uterine cervix; NO could inhibit the growth and proliferation and enhance the apoptosis of cervical cancer cells, inhibit the expression of HPV18 E6, E7 mRNA in HeLa cells and activate the expression of p53 protein, the mechanism may be due to higher sensitivity of HeLa cells (cervical adenocarcinoma cell) to SNP. The increasing release of NO may play a role in regulating the elimination of HPV in cervical microenvironment, which is a part of mucous membrane immunity.

Objective: To investigate the effects of follicle stimulating hormone (FSH) on the proliferation, apoptosis, migration and invasion of ovarian cancer cells., Methods: Ovarian cancer cells of the lines SKOV-3 and ES-2 were cultured, and treated by FSH of the concentrations of 10, 20, 40, 80, and 160 mU/ml for 48 h or 24 h respectively. The cells without FSH treatment were used as control cells. The proliferative effects of the cells were detected by MTT colorimetry. The apoptosis and cell cycle were examined by flow cytometry. The matrix metalloproteinases-2 (MMP-2) protein levels in the supernatant were determined by zymography. The cytoplasm levels of MMP-2 protein in cells were tested by Western blotting. RT-PCR was used to detect the expression of MMP-2 mRNA in cells. The migration and invasion of the cells were examined., Results: The a values of the SKOV-3 treated with FSH of the concentrations of 10 - 160 mU/ml were all significantly higher than those without FSH treatment (all P < 0.01). The apoptosis rates of the SKOV-3 treated with FSH of the concentrations 10 - 160 mU/ml were (0.94 +/- 0.06)%, (0.71 +/- 0.03)%, (0.22 +/- 0.02)%, (0.32 +/- 0.02)%, and (0.55 +/- 0.05)% respectively, all significantly lower than those without FSH treatment [(1.30 +/- 0.10)%, all P < 0.01]. After treatment with FSH of the concentrations 40 to 160 mU/ml the percentages of the SKOV-3 at the stage G(0)/G(1) gradually decreased and the cells at the stage S gradually increased compared with the control groups (all P < 0.05). The MMP-2 mRNA and protein expression levels of the SKOV-3 increased with the concentration increase of FSH (P < 0.05 or P < 0.01). Boyden chamber invasive assay showed that the numbers of the SKOV-3 that penetrated the basement membrane were (157 +/- 20)/hp (x200), significantly higher than those of the control groups [(27 +/- 9)/hp, P < 0.01]. Scarification test showed that the distance between scratches of the FSH-treated SKOV-3 cells was significantly shorter than that of the control group (P < 0.01). FSH also induced similar results in ES-2 cells., Conclusion: FSH induces the proliferation, migration, and invasion and suppresses the apoptosis of ovarian cancer cells.