A novel multivalent DNA helix-based inhibitor showed enhanced anti-HIV-1 fusion activity
EUROPEAN JOURNAL OF PHARMACEUTICAL SCIENCES
Authors: Tang, Yongjia; Han, Zeye; Ren, Hongqian; Guo, Jiamei; Chong, Huihui; Tian, Yangli; Liu, Keliang; Xu, Liang
Abstract
DNA helix-based HIV-1 fusion inhibitors have been discovered as potent drug candidates, but further research is required to enhance their efficiency. The trimeric structure of the HIV-1 envelope glycoprotein provides a structural basis for multivalent drug design. In this work, a "multi-domain" strategy was adopted for design of an oligodeoxynucleotide with assembly, linkage, and activity domains. Built on the self-assembly of higher-order nucleic acid structure, a novel category of multivalent DNA helix-based HIV-1 fusion inhibitor could be easily obtained by a simple annealing course in solution buffer, with no other chemical synthesis for multivalent connection. An optimized multivalent molecule, M4, showed significantly higher anti-HIV-1 fusion activity than did corresponding monovalent inhibitors. Examination of the underlying mechanism indicated that M4 could interact with HIV-1 glycoproteins gp120 and gp41, thereby inhibiting 6HB formation in the fusion course. M4 also showed anti-RDDP and anti-RNase H activity of reverse transcriptase. Besides, these assembled molecules showed improved in vitro metabolic stability in liver homogenate, kidney homogenate, and rat plasma. Moreover, little acute toxicity was observed. Our findings aid in the structural design and understanding of the mechanisms of DNA helix-based HIV-1 inhibitors. This study also provides a general strategy based on a new structural paradigm for the design of other multivalent nucleic acid drugs.
HIV-1 Protein gp120 Induces Mouse Lung Fibroblast-to-Myofibroblast Transdifferentiation via CXCR4 Activation
AMERICAN JOURNAL OF THE MEDICAL SCIENCES
Authors: Marts, Lucian T.; Guidot, David M.; Sueblinvong, Viranuj
Abstract
Background: Individuals with HIV have similar to 2-fold increased risk of developing pulmonary fibrosis. The mechanism(s) by which this occurs has yet to be determined. HIV-1 protein gp120 activates CXCR4 in the lymphocyte, promoting a variety of intracellular signaling pathways including those common to TGF beta 1 associated with lung fibroblast-to-myofibroblast transdifferentiation. We hypothesized that gp120 promotes pulmonary fibrotic changes via activation of CXCR4 in the lung fibroblast. Methods: Mouse primary lung fibroblasts (PLFs) were cultured +/- gp120, then analyzed for alpha-SMA expression and stress fiber formation. In parallel, PLFs were cultured +/- gp120 +/- AMD3100 (a CXCR4 antagonist), and alpha-SMA, pan and phosphoAkt, and total and phospho-MAPK (or ERK1/2) protein expression was quantified. Finally, lungs and PLFs from wild-type and HIV-1 transgenic mice were analyzed for hydroxyproline and alpha-SMA content. Results: gp120 treatment increased alpha-SMA expression and myofibroblast differentiation in PLFs. gp120 treatment activated phosphorylation of ERK1/2, but not PI3K-Akt. Pretreatment with AMD3100 inhibited gp120-induced ERK1/2 phosphorylation and gp120-induced alpha-SMA expression. In parallel, there was a significant increase in hydroxyproline content in lungs from older HIV-1 transgenic mice and a >3-fold increase in alpha-SMA expression in PLFs isolated from HIV-1 transgenic mice. Conclusions: gp120 induces alpha-SMA expression and fibroblast-to-myofibroblast transdifferentiation by activating the CXCR4-ERK1/2 signaling pathway in mouse PLFs. Lungs of older HIV-1 transgenic mice contain higher hydroxyproline content and their PLFs have a striking increase in alpha-SMA expression. These results suggest a mechanism by which individuals with HIV are at increased risk of developing pulmonary fibrotic changes as they age.