Coagulation factors VII, IX and X are effective antibacterial proteins against drug-resistant Gram-negative bacteria.

Infections caused by drug-resistant "superbugs" pose an urgent public health threat due to the lack of effective drugs; however, certain mammalian proteins with intrinsic antibacterial activity might be underappreciated. Here, we reveal an antibacterial property against Gram-negative bacteria for factors VII, IX and X, three proteins with well-established roles in initiation of the coagulation cascade. These factors exert antibacterial function via their light chains (LCs). Unlike many antibacterial agents that target cell metabolism or the cytoplasmic membrane, the LCs act by hydrolyzing the major components of bacterial outer membrane, lipopolysaccharides, which are crucial for the survival of Gram-negative bacteria. The LC of factor VII exhibits in vitro efficacy towards all Gram-negative bacteria tested, including extensively drug-resistant (XDR) pathogens, at nanomolar concentrations. It is also highly effective in combating XDR Pseudomonas aeruginosa and Acinetobacter baumannii infections in vivo. Through decoding a unique mechanism whereby factors VII, IX and X behave as antimicrobial proteins, this study advances our understanding of the coagulation system in host defense, and suggests that these factors may participate in the pathogenesis of coagulation disorder-related diseases such as sepsis via their dual functions in blood coagulation and resistance to infection. Furthermore, this study may offer new strategies for combating Gram-negative "superbugs".

Tissue factor-targeted lidamycin inhibits growth and metastasis of colon carcinoma.

Colon cancer is the third most common cancer in the world. The overexpression of tissue factor (TF) in colon cancer cells makes it an ideal target for colon cancer therapy. The purpose of the present study was to develop a TF-targeting energized fusion protein, mlFVII-LDP-AE, which is composed of a mouse Factor VII light chain (mlFVII) as the targeting domain conjugated to the highly cytotoxic antibiotic lidamycin (LDM, LDP-AE) as the effector domain. The potential efficacy of mlFVII-LDP-AE for mouse colon cancer therapy was tested in a mouse colon cancer subcutaneous xenograft model and a live metastasis model in BALB/c mice. mlFVII-LDP-AE showed a tumor growth inhibition rate of 91.2% (at a dose of 0.8 mg/kg) and a tumor metastasis inhibition rate of 84.7% (at a dose of 0.6 mg/kg). The results showed that mlFVII-LDP-AE was able to effectively inhibit the growth and metastasis of mouse colon cancer. As human TF and FVII have features similar to those of mice, human FVII light chain (hlFVII)-targeted LDM (hlFVII-LDP-AE) may be expected to have therapeutic potential for human colon cancer.

Factor VII light chain-targeted lidamycin targets tissue factor-overexpressing tumor cells for cancer therapy.

The overexpression of tissue factor (TF) observed in numerous cancer cells and clinical samples of human cancers make TF an ideal target for cancer therapy. Here, we report an energized fusion protein, hlFVII-LDP-AE, which can be used for cancer therapy and is composed of a human Factor VII light chain (hlFVII) conjugated to the cytotoxic antibiotic lidamycin (LDM, LDP-AE). hlFVII-LDP-AE binds with specificity to TF expressed on tumor cells, resulting in internalization of the fusion protein and cytotoxicity induced by the LDM domain. The potential efficacy of hlFVII-LDP-AE for cancer therapy was examined in vitro by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and in vivo with a BALB/c nude mouse xenograft model of the human lung cancer line NCI-H292. hlFVII-LDP-AE caused chromatin condensation and cleavage of genomic DNA in NCI-H292 cells. In the MTT assays, the IC50 value of hlFVII- LDP-AE was 0.19 nM. In the in vivo tests, after two intravenous injections of hlFVII-LDP-AE at a dose of 0.6 mg/kg, the growth rate of the lung tumor xenograft was reduced to 15% of the control rate, and there was no excessive loss of body weight and inflammatory response in the mice. These findings suggest that hlFVII-LDP-AE is efficacious and tolerated in the mouse model of NCI-H292 human lung cancer examined and could have broad clinical applicability for treating cancer patients.

Rheological properties of a telechelic associative polymer in the presence of alpha- and methylated beta-cyclodextrins.

The viscosity of hydrophobic ethoxylated urethane (HEUR) solution decreased in the presence of alpha-CD or m-beta-CD; however their interactions were quite different. When the alpha-CD/hydrophobe molar ratio exceeded 5.0, the viscosity was close to that of a PEO solution of similar molecular weight. Oscillatory shear indicated that the mechanically active chains in HEUR solution decreased with the addition of alpha-CD. This agreed with the hypothesis that alpha-CD formed an inclusion complex with the hydrophobic moiety of the HEUR polymer, thereby destroying the transient hydrophobic associative network. The viscosity/temperature relationship of the alpha-CD/HEUR system (for HEUR with 70% of the PEO chains capped at both ends) did not obey the Arrhenius relationship for alpha-CD/hydrophobe molar ratio in the range 0.8-5.0. The low shear viscosity increased with increasing temperature at molar ratio of 1.0, and this was attributed to the competitive complexation of the alpha-CD/hydrophobe and the alpha-CD/PEO chain. Increasing temperature favored alpha-CD/PEO complexation. Comparison between the behavior of alpha-CD/HEUR and m-beta-CD/HEUR resulting from the different binding characteristics was discussed.