Characterization and functional analysis of cathelicidin-MH, a novel frog-derived peptide with anti-septicemic properties.

Antimicrobial peptides form part of the innate immune response and play a vital role in host defense against pathogens. Here we report a new antimicrobial peptide belonging to the cathelicidin family, cathelicidin-MH (cath-MH), from the skin of Microhyla heymonsivogt frog. Cath-MH has a single α-helical structure in membrane-mimetic environments and is antimicrobial against fungi and bacteria, especially Gram-negative bacteria. In contrast to other cathelicidins, cath-MH suppresses coagulation by affecting the enzymatic activities of tissue plasminogen activator, plasmin, ß-tryptase, elastase, thrombin, and chymase. Cath-MH protects against lipopolysaccharide (LPS)- and cecal ligation and puncture-induced sepsis, effectively ameliorating multiorgan pathology and inflammatory cytokine through its antimicrobial, LPS-neutralizing, coagulation suppressing effects as well as suppression of MAPK signaling. Taken together, these data suggest that cath-MH is an attractive candidate therapeutic agent for the treatment of septic shock.

Esc-1GN shows therapeutic potentials for acne vulgaris and inflammatory pain.

The inflammatory response plays important roles in acne vulgaris and pain pathogenesis. In previous study, Esc-1GN with anti-inflammatory, antimicrobial, and lipopolysacchride (LPS) binding activity was identified from the skin of the frog Hylarana guentheri. Here, we report its therapeutic potentials for acne vulgaris and inflammatory pain. Esc-1GN destroyed the cell membrane of Propionibacteria acnes in the membrane permeability assays. In addition, bacterial agglutination test suggested that Esc-1GN triggered the agglutination of P. acnes, which was affected by LPS and Ca2+ . Meanwhile, in vivo anti-P. acnes and anti-inflammatory effects of Esc-1GN were confirmed by reducing the counts of P. acnes in mice ear, relieving P. acnes-induced mice ear swelling, decreasing mRNA expression and the production of pro-inflammatory cytokines, and attenuating the infiltration of inflammatory cells. Moreover, Esc-1GN also displayed antinociceptive effect in mice induced by acetic acid and formalin. Therefore, Esc-1GN is a promising candidate drug for treatment of acne vulgaris and inflammatory pain.

Identification of relevant variables and construction of a multidimensional index for predicting mortality in COPD patients.

Background and objective: The Body mass index, airflow Obstruction, Dyspnea, and Exercise (BODE) index is a well-known metric for chronic obstructive pulmonary disease (COPD), but it is inadequate for predicting mortality. This study proposed a new index that combines inspiratory muscle training with the BODE index and verified its ability to predict mortality in patients with COPD. Methods: Cox regression identified predictors of mortality, which were then included in the new index. The receiver operating characteristic (ROC) curve verified the ability of the new index to predict mortality. The Kaplan-Meier curves compared the survival rates of patients with different scores on the new index. Results: Among the 326 patients, 48 died during follow-up (1-59 months). Cox regression showed that the fat-free mass index (FFMI), forced expiratory volume in one second/the predicted value (FEV1%), modified Medical Research Council (mMRC) score, six-minute-walk test (6MWT) distance, and maximal inspiratory pressure were predictors of mortality (P<0.05); these variables were included in the FODEP index. The AUC of the FODEP index (0.860, 95% CI: 95% CI: 0.817-0.896) was greater than that of the BODE index (0.778, 95% CI: 0.729-0.822). The Kaplan-Meier curves suggested that as the FODEP score increased, so did the risk of morality in patients with COPD. The cumulative survival in the group with the highest FODEP-value was significantly lower than that in the other groups (P<0.01). Conclusion: The FODEP index was more effective than the BODE index at predicting the risk of mortality in patients with COPD.

The anticancer properties and mechanism of action of tablysin-15, the RGD-containing disintegrin, in breast cancer cells.

αvß3 integrin expressed on cancer cell surfaces is associated with important cancer hallmarks including survival and metastasis and is thus a potential anticancer drug target. Tablysin-15 contains the RGD motif and is a high-affinity αvß3 integrin antagonist. The aim of this study was to investigate the antitumor effect and mechanism of action of tablysin-15 against αvß3 integrin high-expressing breast cancer cell lines in vitro and in vivo. Tablysin-15 dose-dependently inhibited the proliferation, migration, and invasion of two breast cancer cell lines via the αvß3 integrin in vitro. Proliferation inhibition was attributable to G0/G1 phase cell cycle arrest rather than apoptosis or necrosis. Furthermore, tablysin-15 downregulated the activity and mRNA expression of MMP-2/-9, VEGF, and COX-2 but upregulated TIMP-1/-2 mRNA in both cell lines. Further, tablysin-15 suppressed the expression of CDK2, CDK6, cyclin D1, and cyclin E, the phosphorylation of FAK, Akt, GSK-3ß, and ERK, and the nuclear translocation of NF-κB while increasing the expression of the CDK inhibitor p21waf1/C1. Lastly, tablysin-15 provided effective antitumor protection in vivo. Thus, tablysin-15 inhibits the metastasis and proliferation of breast cancer cells through binding αvß3 integrin and blocking FAK-associated signaling pathways as well as nuclear translocation of NF-κB.

Functional Characterization of a Novel Lipopolysaccharide-Binding Antimicrobial and Anti-Inflammatory Peptide in Vitro and in Vivo.

Antimicrobial peptides (AMPs) are key components of host immune defense of vertebrates against microbial invasions. Here, we report a new AMP (esculentin-1GN) characterized from the skin of the frog Hylarana guentheri. Esculentin-1GN (GLFSKKGGKGGKSWIKGVFKGIKGIGKEVGGDVIRTGIEIAACKIKGEC) with high amphipathic α-helical structure in membrane-mimetic environments has the microbial-killing activity by destruction of the cell membrane. Moreover, esculentin-1GN inhibits LPS-induced expression of proinflammatory nitric oxide, interleukin-1ß, interleukin-6, and tumor necrosis factor while it enhances expression of interleukin-10. Furthermore, esculentin-1GN can bind to d-(+)-galacturonic acid and LPS. Meanwhile, esculentin-1GN suppresses the activation of inflammatory response pathway induced by LPS. In addition, esculentin-1GN significantly reduces acute inflammation in carrageenan-induced mice paw. Taken together, the novel LPS-binding esculentin-1GN with antimicrobial and anti-inflammatory activities will be an excellent temple for designing new antibiotic formulations.