The levels of Brachyspira hyodysenteriae binding to porcine colonic mucins differ between individuals, and binding is increased to mucins from infected pigs with de novo MUC5AC synthesis

Brachyspira hyodysenteriae colonizes the pig colon, resulting in mucohemorrhagic diarrhea and growth retardation. Fecal mucus is a characteristic feature of swine dysentery; therefore, we investigated how the mucin environment changes in the colon during infection with B. hyodysenteriae and how these changes affect this bacterium's interaction with mucins. We isolated and characterized mucins, the main component of mucus, from the colon of experimentally inoculated and control pigs and investigated B. hyodysenteriae binding to these mucins. Fluorescence microscopy revealed a massive mucus induction and disorganized mucus structure in the colon of pigs with swine dysentery. Quantitative PCR (qPCR) and antibody detection demonstrated that the mucus composition of pigs with swine dysentery was characterized by de novo expression of MUC5AC and increased expression of MUC2 in the colon. Mucins from the colon of inoculated and control pigs were isolated by two steps of isopycnic density gradient centrifugation. The mucin densities of control and inoculated pigs were similar, whereas the mucin quantity was 5-fold higher during infection. The level of B. hyodysenteriae binding to mucins differed between pigs, and there was increased binding to soluble mucins isolated from pigs with swine dysentery. The ability of B. hyodysenteriae to bind, measured in relation to the total mucin contents of mucus in sick versus healthy pigs, increased 7-fold during infection. Together, the results indicate that B. hyodysenteriae binds to carbohydrate structures on the mucins as these differ between individuals. Furthermore, B. hyodysenteriae infection induces changes to the mucus niche which substantially increase the amount of B. hyodysenteriae binding sites in the mucus

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

The O-Linked Glycome and Blood Group Antigens ABO on Mucin-Type Glycoproteins in Mucinous and Serous Epithelial Ovarian Tumors.

Mucins are heavily O-glycosylated proteins where the glycosylation has been shown to play an important role in cancer. Normal epithelial ovarian cells do not express secreted mucins, but their abnormal expression has previously been described in epithelial ovarian cancer and may relate to tumor formation and progression. The cyst fluids were shown to be a rich source for acidic glycoproteins. The study of these proteins can potentially lead to the identification of more effective biomarkers for ovarian cancer.In this study, we analyzed the expression of the MUC5AC and the O-glycosylation of acidic glycoproteins secreted into ovarian cyst fluids. The samples were obtained from patients with serous and mucinous ovarian tumors of different stages (benign, borderline, malignant) and grades. The O-linked oligosaccharides were released and analyzed by negative-ion graphitized carbon Liquid Chromatography (LC) coupled to Electrospray Ionization tandem Mass Spectrometry (ESI-MSn). The LC-ESI-MSn of the oligosaccharides from ovarian cyst fluids displayed differences in expression of fucose containing structures such as blood group ABO antigens and Lewis-type epitopes.The obtained data showed that serous and mucinous benign adenomas, mucinous low malignant potential carcinomas (LMPs, borderline) and mucinous low-grade carcinomas have a high level of blood groups and Lewis type epitopes. In contrast, this type of fucosylated structures were low abundant in the high-grade mucinous carcinomas or in serous carcinomas. In addition, the ovarian tumors that showed a high level of expression of blood group antigens also revealed a strong reactivity towards the MUC5AC antibody. To visualize the differences between serous and mucinous ovarian tumors based on the O-glycosylation, a hierarchical cluster analysis was performed using mass spectrometry average compositions (MSAC).Mucinous benign and LMPs along with mucinous low-grade carcinomas appear to be different from serous and high-grade mucinous carcinomas based on their O-glycan profiles

Dynamic changes in mucus thickness and ion secretion during Citrobacter rodentium infection and clearance.

Citrobacter rodentium is an attaching and effacing pathogen used as a murine model for enteropathogenic Escherichia coli. The mucus layers are a complex matrix of molecules, and mucus swelling, hydration and permeability are affected by many factors, including ion composition. Here, we used the C. rodentium model to investigate mucus dynamics during infection. By measuring the mucus layer thickness in tissue explants during infection, we demonstrated that the thickness changes dynamically during the course of infection and that its thickest stage coincides with the start of a decrease of bacterial density at day 14 after infection. Although quantitative PCR analysis demonstrated that mucin mRNA increases during early infection, the increased mucus layer thickness late in infection was not explained by increased mRNA levels. Proteomic analysis of mucus did not demonstrate the appearance of additional mucins, but revealed an increased number of proteins involved in defense responses. Ussing chamber-based electrical measurements demonstrated that ion secretion was dynamically altered during the infection phases. Furthermore, the bicarbonate ion channel Bestrophin-2 mRNA nominally increased, whereas the Cftr mRNA decreased during the late infection clearance phase. Microscopy of Muc2 immunostained tissues suggested that the inner striated mucus layer present in the healthy colon was scarce during the time point of most severe infection (10 days post infection), but then expanded, albeit with a less structured appearance, during the expulsion phase. Together with previously published literature, the data implies a model for clearance where a change in secretion allows reformation of the mucus layer, displacing the pathogen to the outer mucus layer, where it is then outcompeted by the returning commensal flora. In conclusion, mucus and ion secretion are dynamically altered during the C. rodentium infection cycle

Hierarchical cluster analyses of <i>O</i>-glycans from serous and mucinous ovarian tumors.

<p>The clustering based on three variables Fuc, NeuAc and S (A) and also only the two variables NeuAc and S (B). The variables were evaluated using ROC AUC (C). The dendrograms (A, B) identify mucinous benign, LMPs and low-grade ovarian tumors as a distinct group (the group is marked by red color) separate from serous and high grade mucinous samples (the group marked in black). The exception is the LMP mucinous cyst fluid sample obtained from a non-secretor patient (green color). A separate cluster is generated by the two serous benign samples (violet color).</p

Examples of oligosaccharide epitopes expressed by mucin-type glycoproteins.

<p>Examples of oligosaccharide epitopes expressed by mucin-type glycoproteins.</p

Mucins identified by mass spectrometry in cyst fluid samples obtained from patients with serous and mucinous ovarian benign tumors and stage I, III EOC.

<p><b>Mw-</b>Molecular weight of apoprotein obtained from protein database.</p><p><b>Protein expectation value—log(e)</b>, the base 10 log of the expectation that the protein assignment was made at random. All identifications are of high confidence.</p><p><b>№ of peptides identified</b>-the number of unique and total peptides used in the identification.</p><p>Mucins identified by mass spectrometry in cyst fluid samples obtained from patients with serous and mucinous ovarian benign tumors and stage I, III EOC.</p

Localization of MUC5AC and MUC16 in mucinous adenocarcinoma.

<p>Serial sections from low-grade mucinous adenocarcinoma stage IV (¹⁰M-Low-IV) from (left-right) stained against MUC5AC and MUC16. The histological staining indicated that MUC5AC and MUC16 were expressed on discrete areas in the tumor.</p

Tissue localization of α-fucose, MUC5AC (gel-forming mucin) and MUC16/CA125 (trans-membrane mucin) in benign, low-grade and high-grade serous and mucinous ovarian tumor cells.

<p>The figure shows the tissues from mucinous benign (¹M-B), low-grade (⁷M-Low-IA), high-grade (¹³M-High-IB) as well as from serous benign (¹⁴S-B), low-grade (²⁰S-Low-III), high-grade (²¹S-High-IIIC) tumors (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130197#pone.0130197.t002" target="_blank">Table 2</a>). Tissues were stained with lectin (UEA I) against fucose, or mucin specific antibodies (anti-MUC5AC and anti-MUC16).</p

LC-ESI-MS spectra of <i>O</i>-linked oligosaccharides from mucinous and serous cyst fluids.

<p>Oligosaccharides was released by reductive β-elimination from acidic glycoproteins secreted into ovarian cyst fluids obtained from patients with high- and low-grade mucinous (A,B) and serous (C,D) OEC. Combined spectra of components eluted in the region 14–35 minutes in the chromatogram. Only major peaks identified are indicated. For all identified structures see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130197#pone.0130197.s001" target="_blank">S1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0130197#pone.0130197.s002" target="_blank">S2</a> Tables. Fig 1A shows high abundant structures in low grade mucinous samples that are terminating with blood group O/H and blood group A, while structures in high grade mucinous (Fig 1B) as well as both low and high grade serous samples are terminating with sialic acid. *<i>N</i>-linked oligosaccharides also observed in the spectra.</p