Expression of the K54 and O4 specific antigen has opposite effects on the bactericidal activity of squalamine against an extraintestinal isolate of Escherichia coli

From Marine Metabolites to the Drugs of the Future: Squalamine, Trodusquemine, Their Steroid and Triterpene Analogues

This review comprehensively describes the recent advances in the synthesis and pharmacological evaluation of steroid polyamines squalamine, trodusquemine, ceragenins, claramine, and their diverse analogs and derivatives, with a special focus on their complete synthesis from cholic acids, as well as an antibacterial and antiviral, neuroprotective, antiangiogenic, antitumor, antiobesity and weight-loss activity, antiatherogenic, regenerative, and anxiolytic properties. Trodusquemine is the most-studied small-molecule allosteric PTP1B inhibitor. The discovery of squalamine as the first representative of a previously unknown class of natural antibiotics of animal origin stimulated extensive research of terpenoids (especially triterpenoids) comprising polyamine fragments. During the last decade, this new class of biologically active semisynthetic natural product derivatives demonstrated the possibility to form supramolecular networks, which opens up many possibilities for the use of such structures for drug delivery systems in serum or other body fluids.

Synthesis and Biological Activities of Naturally Functionalized Polyamines: An Overview

Recently, extensive researches have emphasized the fact that polyamine conjugates are becoming important in all biological and medicinal fields. In this review, we will focus our attention on natural polyamines and highlight recent progress in both fundamental mechanism studies and interests in the development and application for the therapeutic use of polyamine derivatives.

Infecting mice with recombinant Ad5-BPI₂₃-Fcγ1 virus protects against systemic Escherichia coli challenge

Infections caused by Gram-negative bacteria (GNB) are increasingly common and can result in significant mortality rates due to the development of sepsis. To examine the potential usage of a recombinant Ad5-BPI(23)-Fcγ1 virus as a biological treatment against systemic infection by GNB, a construct containing the human bactericidal/permeability increasing protein (BPI) gene, encoding the functional N terminus (amino acid residues 1-199) of human BPI, and the Fcγ1 gene, encoding the Fc segment of human immunoglobulin G1, was inserted into an adenovirus serotype 5 (Ad5) chromosome to produce a recombinant Ad5-BPI(23)-Fcγ1 virus. Human A549 cells in culture and BALB/c mice were infected with the recombinant Ad5-BPI(23)-Fcγ1 virus and BPI(23)-Fcγ1 expression was confirmed by Western blot analysis and ELISA. The concentrations of BPI(23)-Fcγ1 protein were 5.59 µg ml(-1) in vitro and 21.37 ng ml(-1) in vivo and it was observed that these concentrations were sufficient to decrease endotoxin concentrations while enhancing bactericidal activity. In addition, mice treated with the recombinant Ad5-BPI(23)-Fcγ1 virus had decreased levels of IL-1β and TNF-α and were protected from an E. coli O111 : B4 challenge. Our data support the concept that Ad5-mediated BPI(23)-Fcγ1 gene delivery could be used as an ancillary biological treatment in the management of infection caused by GNB.