Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema

BACKGROUND: Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. METHODS: Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. RESULTS: Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. CONCLUSION: The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers

SNARE Protein Mimicry by an Intracellular Bacterium

Many intracellular pathogens rely on host cell membrane compartments for their survival. The strategies they have developed to subvert intracellular trafficking are often unknown, and SNARE proteins, which are essential for membrane fusion, are possible targets. The obligate intracellular bacteria Chlamydia replicate within an intracellular vacuole, termed an inclusion. A large family of bacterial proteins is inserted in the inclusion membrane, and the role of these inclusion proteins is mostly unknown. Here we identify SNARE-like motifs in the inclusion protein IncA, which are conserved among most Chlamydia species. We show that IncA can bind directly to several host SNARE proteins. A subset of SNAREs is specifically recruited to the immediate vicinity of the inclusion membrane, and their accumulation is reduced around inclusions that lack IncA, demonstrating that IncA plays a predominant role in SNARE recruitment. However, interaction with the SNARE machinery is probably not restricted to IncA as at least another inclusion protein shows similarities with SNARE motifs and can interact with SNAREs. We modelled IncA's association with host SNAREs. The analysis of intermolecular contacts showed that the IncA SNARE-like motif can make specific interactions with host SNARE motifs similar to those found in a bona fide SNARE complex. Moreover, point mutations in the central layer of IncA SNARE-like motifs resulted in the loss of binding to host SNAREs. Altogether, our data demonstrate for the first time mimicry of the SNARE motif by a bacterium

Multi-genome identification and characterization of chlamydiae-specific type III secretion substrates: the Inc proteins

<p>Abstract</p> <p>Background</p> <p><it>Chlamydiae </it>are obligate intracellular bacteria that multiply in a vacuolar compartment, the inclusion. Several chlamydial proteins containing a bilobal hydrophobic domain are translocated by a type III secretion (TTS) mechanism into the inclusion membrane. They form the family of Inc proteins, which is specific to this phylum. Based on their localization, Inc proteins likely play important roles in the interactions between the microbe and the host. In this paper we sought to identify and analyze, using bioinformatics tools, all putative Inc proteins in published chlamydial genomes, including an environmental species.</p> <p>Results</p> <p>Inc proteins contain at least one bilobal hydrophobic domain made of two transmembrane helices separated by a loop of less than 30 amino acids. Using bioinformatics tools we identified 537 putative Inc proteins across seven chlamydial proteomes. The amino-terminal segment of the putative Inc proteins was recognized as a functional TTS signal in 90% of the <it>C. trachomatis </it>and <it>C. pneumoniae </it>sequences tested, validating the data obtained <it>in silico</it>. We identified a <it>macro </it>domain in several putative Inc proteins, and observed that Inc proteins are enriched in segments predicted to form coiled coils. A surprisingly large proportion of the putative Inc proteins are not constitutively translocated to the inclusion membrane in culture conditions.</p> <p>Conclusions</p> <p>The Inc proteins represent 7 to 10% of each proteome and show a great degree of sequence diversity between species. The abundance of segments with a high probability for coiled coil conformation in Inc proteins support the hypothesis that they interact with host proteins. While the large majority of Inc proteins possess a functional TTS signal, less than half may be constitutively translocated to the inclusion surface in some species. This suggests the novel finding that translocation of Inc proteins may be regulated by as-yet undetermined mechanisms.</p

Is adenomyosis the neglected phenotype of an endomyometrial dysfunction syndrome?

Since the dissociation between adenomyoma and endometriosis in the 1920s and the laparoscopic progress in the diagnosis and surgery of endometriosis, the literature has been greatly focused on the disease endometriosis. The study of adenomyosis, on the other hand, has been neglected as the diagnosis remained based on hysterectomy specimens. However, since the introduction of magnetic resonance and sonographic imaging techniques in the 1980s, the myometrial junctional zone has been identified as a third uterine zone and interest in adenomyosis was renewed. This has also been the start for the interest in the role of the myometrial junctional zone dysfunction and adenomyosis in reproductive and obstetrical disorders

Drug delivery to tumours using a novel 5-FU derivative encapsulated into lipid nanocapsules

In this work, a novel lipophilic 5-fluorouracil (5-FU) derivative was synthesised and encapsulated into lipid nanocapsules (LNC). 5-FU was modified with lauric acid to give a lipophilic mono-lauroyl-derivative (5-FU-C12, MW of about 342 g/mol, yield of reaction 70%). 5-FU-C12 obtained was efficiently encapsulated into LNC (encapsulation efficiency above 90%) without altering the physico-chemical characteristics of LNC. The encapsulation of 5-FU-C12 led to an increased stability of the drug when in contact with plasma being the drug detectable until 3 h following incubation. Cytotoxicity assay carried out using MTS on 2D cell culture showed that 5-FU-C12-loaded LNC had an enhanced cytotoxic effect on glioma (9L) and human colorectal (HTC-116) cancer cell line in comparison with 5-FU or 5-FU-C12. Then, HCT-116 tumour spheroids were cultivated and the reduction of spheroid volume was measured following treatment with drug-loaded LNC and drugs alone. Similar reduction on spheroids volume was observed following the treatment with drug-loaded LNC, 5-FU-C12 and 5-FU alone, while blank LNC displayed a reduction in cell viability only at high concentration. Globally, our data suggest that the encapsulation increased the activity of the 5-FU-C12. However, in-depth evaluations of LNC permeability into spheroids are needed to disclose the potential of these nanosystems for cancer treatment