Polar Invasion and Translocation of Neisseria meningitidis and Streptococcus suis in a Novel Human Model of the Blood-Cerebrospinal Fluid Barrier

Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens

Type 2 diabetes and its correlates in a first nationwide study among Cypriot adults

© 2017 Primary Care Diabetes Europe Obesity rates in Cyprus are very high and epidemiological information on type 2 diabetes mellitus is limited. The correlates of type 2 diabetes among adults remain unknown in the Cypriot population. Thus, the purpose of this study is to provide the first national estimate of the prevalence of type 2 diabetes and investigate its correlates. A randomly stratified nationally sample of 1001 adults aged 18–80 participated in the study. Only 950 subjects completed the study. All subjects were free of any diseases (known diabetes, kidney, liver), medication and supplementation. The overall prevalence of diabetes and pre-diabetes based on WHO criteria was 9.2% and 16.3%, respectively. After adjusting for age, energy intake, smoking and physical activity participants with obesity (BMI) (OR = 2.00, P \u3c 0.001), waist circumference (WC) (OR = 2.08, P \u3c 0.001), hypertension (HT) (OR = 1.99, P \u3c 0.001) and hypercholesterolemia (HC) (OR = 2.07, P \u3c 0.007) were most likely to develop T2DM compared with the normal ones. The odds of having diabetes were also found significant between subjects with high levels of triglycerides (TG) (OR = 1.49, P \u3c 0.007), compared with the normal ones and between subjects with low levels of HDL (OR = 1.44, P \u3c 0.008) compared with the ones with high levels of HDL. The prevalence of type 2 diabetes in Cyprus is relatively medium–high. However, the pre-diabetes rates are very high showing a promising increase toward total rates of type 2 diabetes. Obesity, HT, WC, TG, HC and low HDL are all strong correlates of type 2 diabetes. Healthy education programs should be initiated for young and older-aged people and those with described abnormal risk factors

Non-HDL and triglycerides are independently associated with anthropometrical indices in a cypriot population of healthy adults

BACKGROUND: The prevalence of overweight and obesity is increasing all over the world and is accompanied by multiple cardiovascular risk factors. Anthropometrical indices are closely related with traditional cardiovascular risk factors. However, data is limited in healthy adults from Cyprus. AIM: The aim of this study was to examine the relationship of different cardiovascular risk factors with anthropometrical indices in a healthy Cypriot population aged 18-80y. RESULTS: Age, Body Mass Index, Waist Circumference and Body Fat were positively correlated with SBP, DBP and Non-HDL in both sexes. In multiple regression analysis, BMI, WC and TBF were found to be independently associated with TG in the female group, (Beta: 0.009, %95 CI: 0.001-0.018, P\u3c0.033), (Beta: 0.005, %95 CI: 0.002-0.008, P\u3c0.01), (Beta: 0.003, %95 CI: 0.001-0.007, P\u3c0.046), respectively. In the male group, age and BMI were the only variables that have been found to be independently associated with Non-HDL (Beta: 0.527, %95 CI: 0.209- 0845, P\u3c0.01), (Beta: 0544, %95 CI: 0.44-1.045, P\u3c0.033), respectively. CONLUSION: Non-HDL and triglycerides seem to be independently associated with various anthropometrical indexes. Public health awareness and nutrition education are needed in order to monitor these CV factors

Double immunofluorescence microscopy of adherence and invasion of HIBCPP standard cultures infected with <i>S. suis</i> and <i>N. meningitidis</i>, respectively.

<p>HIBCPP grown in the standard culture system were inoculated with the indicated bacteria (MOI 10) and after 4 h subjected to double immunofluorescence microscopy to detect intracellular (green) and extracellular (yellow) bacteria. Cell nuclei were 4,6-diamidino-2-phenylindole (blue)-stained. The actin cytoskeleton was visualized with phalloidin (purple/magenta). Apotom images: bottom of each panel is an <i>xy</i> en face view of HIBCPP shown in a maximum-intensity projection through the <i>z</i>-axis of selected slices; top and side of each panel is a cross-section through the <i>z</i>-plane of multiple optical slices. The apical side of HIBCPP is oriented towards the top or the right side, respectively, of the top and side images of each panel. <i>S. suis</i> strains 10 (<b>A</b>) and 10 cpsΔEF (<b>B</b>) show adherence to the apical membrane but no invasion. <i>N. meningitidis</i> serogroup B strain MC58 (<b>C</b>) and its isogenic acapsular mutant (<b>D</b>) display strong adhesion, but only rare invasion events (arrows). Similarly, <i>N. meningitidis</i> serogroup C strain WUE2120 (<b>E</b>) and its derivatives WUE2517 (siaD⁻) (<b>F</b>), WUE4345 (opcA⁺) (<b>G</b>) and WUE4346 (siaD⁻ opcA⁺) (<b>H</b>) adhere strongly to the apical membrane; invasion is rarely detected. Shown are representative examples of four independent experiments, which gave similar results.</p

High TEER values correlate with low FITC-inulin flux through HIBCPP-layers.

<p>HIBCPP were grown until a TEER above 70Ω×cm² was measured (day 0) and subsequently cultured in 15%, 1%, or 0% FCS, respectively, as indicated. At the indicated days TEER (<b>A</b>) and the FITC-inulin flux (<b>B</b>) were determined. Cells were grown in the standard transwell filter system (1×10⁵ cells; left panels) or the inverted transwell filter system (4×10⁴ cells; right panels). Shown is the mean+/−SD of eight experiments performed in triplicates.</p

HIBCPP display continuous tight junction strands.

<p>HIBCPP grown in the inverted transwell filter system were stained for detection of ZO-1 (<b>A</b>), Occludin (<b>B</b>) and Claudin-1 (<b>C</b>). Pictures presented are Apotome-generated images; <i>bottom</i> of each panel is an <i>xy</i> en face view of a cell culture monolayer shown in a maximum-intensity projection through the z-axis; <i>top and side</i> of each panel is a cross section through the z-plane of multiple optical slices. The apical side of HIBCPP is oriented towards the top or the right side, respectively, of the top and side images of each panel. In A and B the actin cytoskeleton was in parallel stained with phalloidin-FITC. Since Claudin-1 samples were fixed with methanol we could not observe a qualitatively sufficient actin staining. In all samples nuclei were stained with DAPI. The images shown are representative example of multiple stainings.</p

HIBCPP develop high TEER in standard and inverted transwell filter systems.

<p>Throughout this study cells were grown either on the upper side (standard transwell filter system) or the lower side (inverted transwell filter system) of the filter supports (<b>A</b>; schematic representation). For experiments (<b>B</b>, <b>C</b>) HIBCPP were seeded on transwell filters in the amounts indicated in the legend. Cells were cultivated either in the standard transwell filter system (<b>B</b>) or the inverted transwell filter system (<b>C</b>). TEER was measured over time at the days after seeding of the cells as indicated on the x-axis. Shown is the mean+/−SD of four (standard culture) or five (inverted culture) experiments, respectively, each performed in triplicates.</p

Electron microscopic analysis of HIBCPP TJ structure.

<p>HIBCPP were grown on transwell filter supports in the standard (<b>A</b>, <b>C</b>) and the inverted (<b>B</b>, <b>D</b>) culture system, respectively. Transmission electron microscopy studies (<b>A</b>, <b>B</b>) show that in both culture systems the cells are connected by TJs (arrows), which are located close to the apical side as indicated by the presence of microvilli. Examination of HIBCPP by freeze fracture electron microscopy (<b>C</b>, <b>D</b>) revealed a broad band of closely meshed TJ strands. The diameter of meshes were in the magnitude of 0.2 to 0.4 µm.</p

Analysis of transmigrated <i>N. meningitidis</i> attached to the apical membrane of HIBCPP.

<p>HIBCPP grown in the inverted system were infected with <i>N. meningitidis</i> strain WUE4346 (siaD⁻ opcA⁺) at an MOI of 100 (<b>A</b>) or 10 (<b>B</b>) for 4 h and subsequently analysed by scanning electron microscopy. Single bacteria (<b>A</b>) and microcolonies (<b>A</b>, <b>B</b>) are located at the apical membrane, which can be identified by the presence of microvilli.</p

Double immunofluorescence microscopy of adherence and invasion of HIBCPP inverted cultures infected with <i>S. suis</i> and <i>N. meningitidis</i>, respectively.

<p>HIBCPP grown in the inverted culture system were inoculated with the indicated bacteria and analysed for intracellular (green) and extracellular (yellow) bacteria as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030069#pone-0030069-g007" target="_blank">Fig. 7</a>. <i>S. suis</i> strains 10 (<b>A</b>) and 10 cpsΔEF (<b>B</b>) invade HIBCPP from the basolateral side. Similarly, basolateral invasion is observed for <i>N. meningitidis</i> serogoup B strain MC58 (<b>C</b>) and its isogenic acapsular mutant (<b>D</b>). <i>N. meningitidis</i> serogroup C strain WUE2120 (<b>E</b>) and its derivatives WUE2517 (siaD⁻) (<b>F</b>), WUE4345 (opcA⁺) (<b>G</b>) and WUE4346 (siaD⁻ opcA⁺) (<b>H</b>) invade HIBCPP from the basolateral side and form microcolonies at the apical membrane. Arrows indicate invaded bacteria directly below apically adhered microcolonies. Shown are representative examples of four independent experiments, which gave similar results.</p