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Background Platelet activation plays a crucial role in the pathogenesis of coronary artery disease (CAD). Platelet P-selectin (CD62P) is a classic platelet activation indicator on the platelet surface, and soluble TREM-like transcript-1 (sTLT-1) is a new indicator. However, the relationship between these two markers and CAD, especially in acute coronary syndrome (ACS), has not been elucidated. This study aimed to investigate CD62P expression on the platelet surface and sTLT-1 expression in serum, as well as to assess their relationship with CAD. Methods We measured the levels of CD62P and sTLT-1 in 83 patients with CAD compared to 49 controls. The association of these indicators with age, blood pressure, lipid profile, body mass index, and liver injury marker level were also examined. Results CD62P concentration was higher in CAD patients than in the control group (P P P Conclusions The consistency of sTLT-1 and CD62P expression levels in CAD patients indicates that sTLT-1 level, the same as CD62P, may be a new marker of platelet activation that is positively related to CAD.

Hypertension is one of the main risks causing cardiovascular diseases. Long noncoding RNAs (lncRNAs) play a critical role in many physiological and pathological conditions. However, their role in hypertension is still unclear. In this study, 460 lncRNAs and 522 mRNA were identified to have different expressions in the thoracic aortas of spontaneously hypertensive rats compared with normotensive Wistar-Kyoto rats through next-generation sequencing. Several randomly selected lncRNAs including NONRATT011842 were validated by qRT-PCR and their potential functions were predicted by co-expression analysis with the help of bioinformatics. Moreover, this study focused on the function of lncRNA NONRATT011842 in the vascular smooth muscle cells (VSMCs) during hypertension and confirmed that NONRATT011842 could interact with PABPC1 to regulate the functions of VSMCs. Therefore, the intervention or utilization of certain lncRNAs could be a new biomarker for the diagnosis and prevention of hypertension.

An antimicrobial peptide, known as V13K, was utilized as the framework to study the effects of charge, hydrophobicity and helicity on the biophysical properties and biological activities of α-helical peptides. Six amino acids (Lys, Glu, Gly, Ser, Ala, and Leu) were individually used to substitute the original hydrophobic valine at the selected sixteenth location on the non-polar face of V13K. The results showed that the single amino acid substitutions changed the hydrophobicity of peptide analogs as monitored by RP-HPLC, but did not cause significant changes on peptide secondary structures both in a benign buffer and in a hydrophobic environment. The biological activities of the analogs exhibited a hydrophobicity-dependent behavior. The mechanism of peptide interaction with the outer membrane and cytoplasmic membrane of Gram-negative bacteria was investigated. We demonstrated that this single amino acid substitution method has valuable potential for the rational design of antimicrobial peptides with enhanced activities.

Enantiomeric amphipathic α-helical antibacterial peptides were synthesized and their biophysical and biological properties under different physiological conditions were studied. In the absence of physiological factors, the L- and D-peptides exhibited similar antimicrobial activities against a broad spectrum of bacteria, even against clinical isolates with resistance to traditional antibiotics. However, in the presence of NaCl, CaCl₂ or human serum albumin (HSA) at physiological concentrations, the enantiomers revealed bacterium-species dependent attenuations in antibacterial activity. In the presence of salts the electrostatic interaction between the peptides and the biomembrane was inhibited. Salts, especially CaCl₂ weakened the ability of the peptides to permeabilize the outer membrane of Gram-negative bacteria, as determined by a 1-N-phenylnaphthylamine uptake assay. HSA exhibited variable inhibitory effects on the activity of the peptides when incubated with different bacterial strains. The peptides showed different binding association abilities to HSA at different molar ratios, regardless of their chirality, resulting in reduced peptide biological activity. The D-peptide performed better than its L-enantiomer in all conditions tested because of its resistance to proteolysis, and may therefore represent a promising candidate for development as a therapeutic agent.

A 15-mer cationic α-helical antimicrobial peptide HPRP-A1 was used as the parent peptide to study the effects of peptide secondary structure on the biophysical properties and biological activities. Without changing the amino acid composition of HPRP-A1, we designed two α-helical peptides with either higher or lower helicity compared with the parent peptide, a β-sheet peptide and a random coiled peptide using de novo design approach. The secondary structures were confirmed by circular dichroism spectroscopy. The three α-helical peptides exhibited comparable antibacterial activities, but their hemolytic activity varied from extreme hemolysis to no hemolysis, which is correlated with their helicity. The β-sheet peptide shows poor antibacterial and strong hemolytic activities. More interestingly, the random coil peptide shows no antibacterial activity against Gram-negative bacteria, weak antibacterial activity against Gram-positive bacteria, and extremely weak hemolytic activity. Bacterial membrane permeabilization was also testified on peptides with different secondary structures. Tryptophan fluorescence experiment revealed that the peptide binding preference to the lipid vesicles for mimicking the prokaryotic or eukaryotic membranes was consistent with their biological activities. With the de novo design approach, we proved that it is important to maintain certain contents of amphipathic secondary structure for a desirable biological activity. We believe that the de novo design approach of relocation of the amino acids within a template sequence could be an effective approach in optimizing the specificity of an antimicrobial peptide.

To determine the effects of biophysical parameters (e.g. charge, hydrophobicity, helicity) of peptides on the mechanism of anticancer activity, we applied a single molecule technique—force spectroscopy based on atomic force microscope (AFM)—to study the interaction force at the single molecule level. The activity of the peptide and analogs against HeLa cells exhibited a strong correlation with the hydrophobicity of peptides. Our results indicated that the action mode between α-helical peptides and cancer cells was largely hydrophobicity-dependent.