A key requirement for CD300f in innate immune responses of eosinophils in colitis

Eosinophils are traditionally studied in the context of type 2 immune responses. However, recent studies highlight key innate immune functions for eosinophils especially in colonic inflammation. Surprisingly, molecular pathways regulating innate immune activities of eosinophil are largely unknown. We have recently shown that the CD300f is highly expressed by colonic eosinophils. Nonetheless, the role of CD300f in governing innate immune eosinophil activities is ill-defined. RNA sequencing of 162 pediatric Crohn's disease patients revealed upregulation of multiple Cd300 family members, which correlated with the presence of severe ulcerations and inflammation. Increased expression of CD300 family receptors was also observed in active ulcerative colitis (UC) and in mice following induction of experimental colitis. Specifically, the expression of CD300f was dynamically regulated in monocytes and eosinophils. Dextran sodium sulfate (DSS)-treated Cd300f^-/- mice exhibit attenuated disease activity and histopathology in comparison with DSS-treated wild type (WT). Decreased disease activity in Cd300f^-/- mice was accompanied with reduced inflammatory cell infiltration and nearly abolished production of pro-inflammatory cytokines. Monocyte depletion and chimeric bone marrow transfer experiments revealed a cell-specific requirement for CD300f in innate immune activation of eosinophils. Collectively, we uncover a new pathway regulating innate immune activities of eosinophils, a finding with significant implications in eosinophil-associated gastrointestinal diseases.

The prognostic significance of faecal calprotectin in patients with inactive inflammatory bowel disease

BACKGROUND

Faecal calprotectin, an established biomarker used to assess mucosal inflammation, has been shown to correlate with endoscopic activity in inflammatory bowel disease (IBD). Longitudinal monitoring of faecal calprotectin, however, has rarely been employed beyond assessment of therapy response and post hoc analyses of clinical trials.

AIM

To study whether consecutive measurements of faecal calprotectin every third month are useful for monitoring patients with IBD in clinical remission.

METHODS

Patients aged 18 years or older, with a known diagnosis of IBD in clinical remission, were prospectively studied. Patients provided faecal samples every third month and were prospectively followed until the first clinical relapse or the end of the 2-year follow-up period. Measurements (EK-CAL, Bühlmann Lab. AG, Switzerland) were done at the end of the study. A Cox model with time-dependent covariates was used for analysis.

RESULTS

Among 104 patients, Crohn's disease (n = 49) and ulcerative colitis (n = 55), 37 had a relapse. A doubling of faecal calprotectin level between two consecutively collected samples was associated with a 101% increased risk of relapse (HR: 2.01; 95% CI: 1.53-2.65; P < 0.001). The relative risk of relapse attenuated with time (HR: 0.80; 95% CI: 0.75-0.86; P < 0.001), by a 20% decrease in risk of relapse per 3-month period since the sample was obtained.

CONCLUSIONS

By consecutively measuring faecal calprotectin every third month, we quantified the risk of relapse related to faecal calprotectin change and observed attenuation of the risk across time. Our data suggest that longitudinal monitoring of faecal calprotectin is informative in predicting relapse in IBD.

Abstract 116: Characterization of a Sodium Responsive Human Sodium Bicarbonate Transporter NBCe2 in Human Proximal Tubule

The electrogenic sodium bicarbonate cotransporter (NBCe2) is encoded by SLC4A5, variants of which have been associated with salt sensitivity of blood pressure (BP), which affects 25% of the adult population. NBCe2 is thought to mediate sodium bicarbonate cotransport primarily in the renal collecting duct, but NBCe2 mRNA is also found in the rodent renal proximal tubule (RPT), another site of bicarbonate transport. The protein expression or function of NBCe2 has not been demonstrated in the human RPT. We validated an NBCe2 antibody by siRNA and Western blot, as well as overexpression of an epitope-tagged NBCe2 construct in both RPT cells (RPTCs) and HEK293 cells. We immune-localized (peptide pre-absorbable) NBCe2 protein in the RPT of fresh and frozen human kidney slices, RPTCs isolated from human urine, and in isolated RPTC apical membrane. NBCe2 was primarily found in the Golgi while NBCe1, another electrogenic member of the same family, was primarily found at the basolateral membrane, under basal conditions. Following a short-term increase in intracellular sodium, NBCe2 expression increased at the apical membrane in cultured slices of human kidney (1.75±0.15 fold increase over basal, N=3, p<0.05) and polarized, immortalized RPTCs (0.08±0.015 vs 0.03±0.006 control, NBCe2/CD13 RFU, N=3, p<0.05), while the basolateral localization of NBCe1 was decreased (30.7±5.4% over basal, N=3, p<0.05). DIDS (electrogenic sodium bicarbonate inhibitor, 500 μM, 10 min) inhibitable bicarbonate dependent pH recovery in the presence of EIPA (NHE inhibitor,100 nM, 10 min) after ammonium chloride prepulse (20 mM, 5 min) was higher in the cells cultured under high salt conditions (26.7±7.2% over basal, N=3, p<0.05). Thus, NBCe2 appears to be important in apical sodium and bicarbonate cotransport under high salt conditions. Future studies will examine the role of NBCe2 in mediating increased renal sodium transport in human salt sensitivity of BP.

Registered Replication Report: Schooler and Engstler-Schooler (1990)

Trying to remember something now typically improves your ability to remember it later. However, after watching a video of a simulated bank robbery, participants who verbally described the robber were 25% worse at identifying the robber in a lineup than were participants who instead listed U.S. states and capitals-this has been termed the "verbal overshadowing" effect (Schooler & Engstler-Schooler, 1990). More recent studies suggested that this effect might be substantially smaller than first reported. Given uncertainty about the effect size, the influence of this finding in the memory literature, and its practical importance for police procedures, we conducted two collections of preregistered direct replications (RRR1 and RRR2) that differed only in the order of the description task and a filler task. In RRR1, when the description task immediately followed the robbery, participants who provided a description were 4% less likely to select the robber than were those in the control condition. In RRR2, when the description was delayed by 20 min, they were 16% less likely to select the robber. These findings reveal a robust verbal overshadowing effect that is strongly influenced by the relative timing of the tasks. The discussion considers further implications of these replications for our understanding of verbal overshadowing.

Infliximab as rescue therapy in hospitalised patients with steroid-refractory acute ulcerative colitis: a long-term follow-up of 211 Swedish patients

BACKGROUND

Rescue therapy with infliximab (IFX) has been proven effective in a steroid-refractory attack of ulcerative colitis (UC). The long-term efficacy is not well described.

AIM

To present a retrospective study of IFX as rescue therapy in UC. Primary end points were colectomy-free survival at 3 and 12 months.

METHODS

In this multicentre study, 211 adult patients hospitalised between 1999 and 2010 received IFX 5 mg/kg as rescue therapy due to a steroid-refractory, moderate-to-severe attack of UC. Exclusion criteria were duration of current flare for >12 weeks, corticosteroid treatment for >8 weeks before hospitalisation, previous IFX therapy or Crohn's disease.

RESULTS

Probability of colectomy-free survival at 3 months was 0.71 (95% CI, 0.64-0.77), at 12 months 0.64 (95% CI, 0.57-0.70), at 3 years 0.59 (95% CI, 0.52-0.66) and at 5 years 0.53 (95% CI, 0.44-0.61). Steroid-free, clinical remission was achieved in 105/211 (50%) and 112/209 (54%) patients at 3 and 12 months respectively. Of 75 colectomies during the first year, 48 (64%) were carried out during the first 14 days, 13 (17%) on days 15-90 and 14 (19%) between 3 and 12 months. There were three (1.4%) deaths during the first 3 months.

CONCLUSIONS

Infliximab is an effective rescue treatment, both short- and long-term, in a steroid-refractory attack of UC. Most IFX failures underwent surgery during the first 14 days, which calls for studies on how to optimise induction treatment with IFX. Serious complications, including mortality, were rare.

Involvement of a putative intercellular signal-recognizing G protein-coupled receptor in the engulfment of Salmonella by the protozoan Tetrahymena

In an effort to investigate the molecular basis of protozoa engulfment-mediated hypervirulence of Salmonella in cattle, we evaluated protozoan G protein-coupled receptors (GPCRs) as transducers of Salmonella engulfment by the model protozoan Tetrahymena. Our laboratory previously demonstrated that non-pathogenic protozoa (including Tetrahymena) engulf Salmonella and then exacerbate its virulence in cattle, but the mechanistic details of the phenomenon are not fully understood. GPCRs were investigated since these receptors facilitate phagocytosis of particulates by Tetrahymena, and a GPCR apparently modulates bacterial engulfment for the pathogenic protozoan Entamoeba histolytica. A database search identified three putative Tetrahymena GPCRs, based on sequence homologies and predicted transmembrane domains, that were the focus of this study. Salmonella engulfment by Tetrahymena was assessed in the presence of suramin, a non-specific GPCR inhibitor. Salmonella engulfment was also assessed in Tetrahymena in which expression of putative GPCRs was knocked-down using RNAi. A candidate GPCR was then expressed in a heterologous yeast expression system for further characterization. Our results revealed that Tetrahymena were less efficient at engulfing Salmonella in the presence of suramin. Engulfment was reduced concordantly with a reduction in the density of protozoa. RNAi-based studies revealed that knock-down of one the Tetrahymena GPCRs caused diminished engulfment of Salmonella. Tetrahymena lysates activated this receptor in the heterologous expression system. These data demonstrate that the Tetrahymena receptor is a putative GPCR that facilitates bacterial engulfment by Tetrahymena. Activation of the putative GPCR seemed to be related to protozoan cell density, suggesting that its cognate ligand is an intercellular signaling molecule.

Dissection of the aorta in Turner syndrome: two cases and review of 85 cases in the literature

Patients with Turner syndrome (TS) are at risk for aortic dissection, but the clinical profile for those at risk is not well described. In addition to reporting two new cases, we performed an electronic search to identify all reported cases of aortic dissection associated with TS. In total, 85 cases of aortic dissection in TS were reported between 1961 and 2006. Dissection occurred at a young age, 30.7 (range 4-64) years, which is significantly earlier than its occurrence in the general female population (68 years). Importantly, in 11% of the cases, neither hypertension nor congenital heart disease were identified, suggesting that TS alone is an independent risk factor for aortic dissection; however, the cases where no risk factors were identified were very poorly documented. A TS aortic dissection registry has been established to determine the natural history and risk factors better (http://www.turnersyndrome.org/).

Fecal levels of leukocyte markers reflect disease activity in patients with ulcerative colitis

OBJECTIVE

A prominent feature of inflammatory bowel disease (IBD) is the presence of inflammatory cells in the gut mucosa, and which contribute to the ongoing inflammatory process. The aim of the study was to evaluate fecal neutrophil, eosinophil, mast cell and macrophage markers in the assessment of disease activity in patients with ulcerative colitis (UC).

METHODS

Twenty-eight patients with active UC; 4 with proctitis, 16 with left-side colitis and 8 with total colitis, were included in the study. Patient history, endoscopy and histopathology were examined and fecal and serum samples were evaluated at inclusion and after 4 and 8 weeks of treatment. Fecal samples were analysed for myeloperoxidase (MPO), eosinophil protein X (EPX), mast cell tryptase, IL-1beta and TNF-alpha using immunoassays. Blood samples were analysed for MPO, EPX, C-reactive protein, orosomucoid and leucocyte counts.

RESULTS

Fecal MPO and IL-1beta levels were elevated in all patients at inclusion despite different disease extensions. Striking reductions in fecal levels of MPO, EPX, tryptase and IL-1beta were observed after 4 weeks of treatment in 20/28 patients with complete remission after 8 weeks. No further reductions were seen in 20/27 patients at 8 weeks. Endoscopic score correlated to IL-1beta at all visits (p<0.01), to MPO at visits 2 and 3 (p<0.05, p<0.001), EPX at visit 2 (p<0.05) and tryptase at visit 3 (p<0.01). Levels of fecal markers also related to histological indices of the disease.

CONCLUSIONS

Measurements of fecal MPO, EPX and IL-1beta could be objective complements to endoscopical and histopathological evaluations in the daily care of patients with UC.

Dissection of the aorta in Turner syndrome: two cases and review of 85 cases in the literature

Girls and women with Turner syndrome are at risk for catastrophic aortic dissection and rupture, but the clinical profile for those at risk is not well described. In addition to reporting two new cases, we performed an electronic search to identify all reported cases of aortic dissection associated with Turner syndrome. Particular attention was paid to the reporting of systemic hypertension (HTN) and congenital heart disease (CHD) which are known risk factors for aortic disease in the general population. In total, 85 cases of aortic dissection in TS were reported between 1961 and 2006. Dissection occurred at a young age, 30.7 (range 4-64) years, which is significantly earlier than its occurrence in the general female population (68 years). Of the cases for which HTN and CHD were explicitly assessed, 15% had HTN alone, 30% had CHD alone and 34% had both. Importantly, in 11% of the cases, neither HTN nor CHD were identified, suggesting that TS alone is an independent risk factor for aortic dissection; however, the cases where no risk factors were identified were very poorly documented. Dissection in women with TS undergoing assisted reproductive techniques (ART) frequently resulted in death. The literature on aortic dissection in TS is sparse and most cases are poorly documented, making it difficult to establish firm guidelines regarding monitoring and treatment. A TS aortic dissection registry has been established to better determine the natural history and risk factors (http://www.tssus.org/readweb.asp?wid = 3092).

Tacoma controls tastes and odours with ozone

The study is focussed on the conditions that would provide the best ozone oxidation to decrease the taste and odour of the water from Eagle Gorge Reservoir. This study incorporated advanced analytical methods, such as solid phase microextraction (SPME) and flavour profile analyses (FPA), to evaluate the best method for improving taste and odour. The study developed first-order relationships between ozone dose and the oxidation of several taste and odour compounds. The results focussed on the importance and interactions between ozone dose, pH, hydrogen peroxide and contact time.

Analysis of oncogenic signaling networks in glioblastoma identifies ASPM as a molecular target

Glioblastoma is the most common primary malignant brain tumor of adults and one of the most lethal of all cancers. Patients with this disease have a median survival of 15 months from the time of diagnosis despite surgery, radiation, and chemotherapy. New treatment approaches are needed. Recent works suggest that glioblastoma patients may benefit from molecularly targeted therapies. Here, we address the compelling need for identification of new molecular targets. Leveraging global gene expression data from two independent sets of clinical tumor samples (n = 55 and n = 65), we identify a gene coexpression module in glioblastoma that is also present in breast cancer and significantly overlaps with the "metasignature" for undifferentiated cancer. Studies in an isogenic model system demonstrate that this module is downstream of the mutant epidermal growth factor receptor, EGFRvIII, and that it can be inhibited by the epidermal growth factor receptor tyrosine kinase inhibitor Erlotinib. We identify ASPM (abnormal spindle-like microcephaly associated) as a key gene within this module and demonstrate its overexpression in glioblastoma relative to normal brain (or body tissues). Finally, we show that ASPM inhibition by siRNA-mediated knockdown inhibits tumor cell proliferation and neural stem cell proliferation, supporting ASPM as a potential molecular target in glioblastoma. Our weighted gene coexpression network analysis provides a blueprint for leveraging genomic data to identify key control networks and molecular targets for glioblastoma, and the principle eluted from our work can be applied to other cancers.

Classification of vascular dementia in the Cardiovascular Health Study Cognition Study

OBJECTIVE

To describe the diagnostic classification of subjects with incident vascular dementia (VaD) participating in the Cardiovascular Health Study (CHS) Cognition Study.

METHODS

The CHS classified 480 incident cases between 1994 and 1999 among 3,608 CHS participants who had brain MRI in 1992 through 1994 and in 1997 through 1998. The patients were diagnosed before and after reviewing the brain MRI.

RESULTS

The pre-MRI classification showed that 52 participants had VaD and 76 had both Alzheimer disease (AD) and VaD. The post-MRI classification showed that the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria classified 61 subjects as having VaD, the National Institute of Neurological Disorders and Stroke-Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) criteria classified 43 subjects as having probable VaD and 10 as possible VaD, and the State of California Alzheimer's Disease Diagnostic and Treatment Center (ADDTC) criteria classified 117 as having probable VaD and 96 as possible. The combination of the ADDTC and National Institute of Neurological and Communication Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria was used to examine the spectrum of vascular disease in dementia. The dementia was attributable to only vascular factors in 56 cases (probable VaD); VaD coexisted with AD in 61 cases, although the VaD component was the leading cause of dementia (probable VaD with AD); AD was the leading cause of dementia in 61 cases (possible VaD and probable AD); and in 29 cases, it was not clear that either AD or VaD was the primary diagnosis (possible AD and possible VaD).

CONCLUSIONS

None of the clinical criteria for VaD identified the same group of subjects. The diagnosis of vascular dementia is difficult in epidemiologic studies because poststroke dementia can be due to Alzheimer disease (AD) and evidence of vascular disease can be found in the MRI of dementia cases without clinical strokes. Whether the clinical progression is related to AD pathology or vascular disease is difficult to establish.

Eosinophil granulocytes are activated during the remission phase of ulcerative colitis

AIM

The aim of this study was to establish a method of investigating intestinal eosinophil and neutrophil granulocytes by flow cytometry, and to compare the distribution and activity of these cells in different stages of ulcerative colitis (UC).

METHODS

Biopsy samples were taken from six locations of the entire colon and from the terminal ileum in 10 patients with active total UC, 10 patients with inactive total UC, eight patients with active distal UC, and 11 control subjects. Cell suspensions from biopsies and from peripheral blood were incubated with fluorophore conjugated monoclonal antibodies. The use of scatter plot-gating and specific antibodies was established in a flow cytometry assay.

RESULTS

Eosinophils were more numerous and more active in patients with active UC than in controls. Interestingly, during inactive UC, the number of activated eosinophils was even larger. Eosinophil activity was high in the rectum of patients with distal colitis but was also slightly elevated in the proximal colon. Neutrophils were increased in number and activity during active but not inactive UC. In patients with distal colitis, activated neutrophils were only found in the sigmoid colon and rectum.

CONCLUSION

With this method, we confirm that neutrophils participate in the inflammatory process during active UC, and that they express a resting phenotype during remission. The finding of activated eosinophils in inflamed intestine strengthens the view of these cells as proinflammatory and tissue damaging. Nevertheless, our new finding of high eosinophil activation during inactive UC suggests that eosinophils play a role in repair of injured epithelium.

Statins and cognitive function in the elderly

OBJECTIVE

To examine the association of statin drug use on cognitive and MRI change in older adults.

METHODS

Participants in the Cardiovascular Health Study, a longitudinal study of people age 65 or older, were classified into three groups determined by whether they were taking statin drugs on a continuous basis, intermittently, or not at all. The untreated group was further divided into categories based on National Cholesterol Education Program recommendations for lipid-lowering treatment. Participants with prevalent or incident clinical TIA or stroke or with baseline Modified Mini-Mental State Examination (3MS) scores at or below 80 were excluded. Outcomes examined included rate of change on the 3MS over an average observational period of 7 years, along with changes in MRI white matter grade and measures of atrophy.

RESULTS

Three thousand three hundred thirty-four participants had adequate data for analysis. At baseline, the untreated group in which lipid-lowering drug treatment was recommended were slightly older, less likely to be on estrogen replacement, and had higher serum cholesterol and lower 3MS scores than the statin-treated group. The rate of decline on the 3MS was 0.48 point/year less in those taking statins compared with the untreated group for which treatment was recommended (p = 0.069) and 0.49 point/year less in statin users compared with the group in which lipid-lowering treatment was not recommended (p = 0.009). This effect remained after controlling for serum cholesterol levels. One thousand seven hundred thirty participants with baseline 3MS scores of > 80 underwent cranial MRI scans on two occasions separated by 5 years. There was no significant difference in white matter grade change or atrophy measures between groups.

CONCLUSION

Statin drug use was associated with a slight reduction in cognitive decline in an elderly population. This relationship could not be completely explained by the effect of statins on lowering of serum cholesterol.