Search

Previous studies have demonstrated that vascular endothelial growth factor (VEGF) is upregulated in patients with hereditary hemorrhagic telangiectasia (HHT). The use of Bevacizumab as an anti-angiogenic treatment agent seems promising. The purpose of the present in vitro study was to determine the efficacy and potential toxicity levels of bevacizumab on cell proliferation and VEGF concentrations in endothelial cells of HHT patients. In this in vitro study, endothelial cells from patients with HHT and HUVECs (control) were incubated with different concentration levels of bevacizumab (2, 4, 6, 8 or 10 mg/ml). After 24, 48 or 72 h, the cell proliferation was assessed by Alamar Blue® Assay and the VEGF levels in the cell culture supernatants were measured by VEGF-ELISA. All endothelial cells incubated with bevacizumab showed an initial decrease in cell proliferation. Cell proliferation recovered within 72 h in cell cultures incubated with concentration levels of up to 4 mg/ml bevacizumab, whereas those incubated with higher concentration levels showed a continuous decline in cell proliferation. VEGF expression decreased after 24 h in cell cultures incubated with bevacizumab concentration levels of 2 and 4 mg/ml but increased again after 48 h. Cell cultures incubated with bevacizumab concentration levels of 10 mg/ml showed a constant decline in VEGF expression without any tendency for recovery. Translating these results into daily clinical practice, the present study suggests that the intranasal submucosal injection of bevacizumab in HHT patients should not exceed a concentration level of 4 mg/ml. Overall, higher bevacizumab concentration levels not only reduce VEGF expression but pose a higher risk of toxic effects on endothelial cells as they jeopardize cell proliferation. [ABSTRACT FROM AUTHOR]

Chlamydia species infect a large range of vertebral hosts and have become of major economic and public health concern over the last decades. They are obligate intracellular bacteria that undergo a unique cycle of development characterized by the presence of two distinct bacterial forms. After infection of the host cell, Chlamydia are found inside a membrane-bound compartment, the inclusion. The surrounding membrane of the inclusion contributes to the host- Chlamydia interface and specific pathogen-derived Inc proteins shape this interface allowing interactions with distinct cellular proteins. In contrast to many other bacteria, Chlamydia species acquire sphingomyelin from the host cell. In recent years a clearer picture of how Chlamydia trachomatis acquires this lipid emerged showing that the bacteria interact with vesicular and non-vesicular transport pathways that involve the recruitment of specific RAB proteins and the lipid-transfer protein CERT. These interactions contribute to the development of a new sphingomyelin-producing compartment inside the host cell. Interestingly, recruitment of CERT is conserved among different Chlamydia species including Chlamydia psittaci . Here we discuss our current understanding on the molecular mechanisms used by C. trachomatis and C. psittaci to establish these interactions and to create a novel sphingomyelin-producing compartment inside the host cell important for the infection., (Copyright © 2019 Banhart, Schäfer, Gensch and Heuer.)

The ability to rewrite large stretches of genomic DNA enables the creation of new organisms with customized functions. However, few methods currently exist for accumulating such widespread genomic changes in a single organism. In this study, we demonstrate a rapid approach for rewriting bacterial genomes with modified synthetic DNA. We recode 200 kb of the Salmonella typhimurium LT2 genome through a process we term SIRCAS (stepwise integration of rolling circle amplified segments), towards constructing an attenuated and genetically isolated bacterial chassis. The SIRCAS process involves direct iterative recombineering of 10-25 kb synthetic DNA constructs which are assembled in yeast and amplified by rolling circle amplification. Using SIRCAS, we create a Salmonella with 1557 synonymous leucine codon replacements across 176 genes, the largest number of cumulative recoding changes in a single bacterial strain to date. We demonstrate reproducibility over sixteen two-day cycles of integration and parallelization for hierarchical construction of a synthetic genome by conjugation. The resulting recoded strain grows at a similar rate to the wild-type strain and does not exhibit any major growth defects. This work is the first instance of synthetic bacterial recoding beyond the Escherichia coli genome, and reveals that Salmonella is remarkably amenable to genome-scale modification., (© The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.)