Citations

AbstractBackgroundLate‐onset Alzheimer's disease (AD) is heritable with 20 genes showing genome‐wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease, we extended these genetic data in a pathway analysis.MethodsThe ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain.ResultsALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (P = 3.27 × 10−12 after multiple testing correction for pathways), regulation of endocytosis (P = 1.31 × 10−11), cholesterol transport (P = 2.96 × 10−9), and proteasome‐ubiquitin activity (P = 1.34 × 10−6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected P = .002–.05).ConclusionsThe immune response, regulation of endocytosis, cholesterol transport, and protein ubiquitination represent prime targets for AD therapeutics.

Ezetimibe inhibits intestinal cholesterol absorption and lowers low‐density lipoprotein cholesterol. Uncontrolled studies have suggested that it reduces liver fat as estimated by ultrasound in nonalcoholic steatohepatitis (NASH). Therefore, we aimed to examine the efficacy of ezetimibe versus placebo in reducing liver fat by the magnetic resonance imaging‐derived proton density‐fat fraction (MRI‐PDFF) and liver histology in patients with biopsy‐proven NASH. In this randomized, double‐blind, placebo‐controlled trial, 50 patients with biopsy‐proven NASH were randomized to either ezetimibe 10 mg orally daily or placebo for 24 weeks. The primary outcome was a change in liver fat as measured by MRI‐PDFF in colocalized regions of interest within each of the nine liver segments. Novel assessment by two‐dimensional and three‐dimensional magnetic resonance elastography was also performed. Ezetimibe was not significantly better than placebo at reducing liver fat as measured by MRI‐PDFF (mean difference between the ezetimibe and placebo arms ‐1.3%, P = 0.4). Compared to baseline, however, end‐of‐treatment MRI‐PDFF was significantly lower in the ezetimibe arm (15%‐11.6%, P < 0.016) but not in the placebo arm (18.5%‐16.4%, P = 0.15). There were no significant differences in histologic response rates, serum alanine aminotransferase and aspartate aminotransferase levels, or longitudinal changes in two‐dimensional and three‐dimensional magnetic resonance elastography‐derived liver stiffness between the ezetimibe and placebo arms. Compared to histologic nonresponders (25/35), histologic responders (10/35) had a significantly greater reduction in MRI‐PDFF (‐4.35 ± 4.9% versus ‐0.30 ± 4.1%, P < 0.019). Conclusions : Ezetimibe did not significantly reduce liver fat in NASH. This trial demonstrates the application of colocalization of MRI‐PDFF‐derived fat maps and magnetic resonance elastography‐derived stiffness maps of the liver before and after treatment to noninvasively assess treatment response in NASH. (H epatology 2015;61:1239–1250)

Despite successful treatment of the clonal plasma cell implicated in its pathogenesis, patients with AL amyloidosis (AL) experience significant morbidity related to underlying amyloid mediated organ dysfunction. While normalization of the serum free light chain measurements [normal ratio of involved and uninvolved free light chains (nFLCr)] is the goal of therapy and centerpiece of hematologic response criteria, achieving (or not achieving) meaningful organ response (OR) is clinically significant for its implications on long‐term symptomatology as well as overall survival (OS), and remains the ultimate goal of treatment. Expectations for organ recovery following successful therapy leading to nFLCr in AL remain poorly described. We evaluated the timeframe and predictive factors for OR, and long‐term outcome, in 313 AL patients who achieved nFLCr following therapy initiation. OR was seen in 80% of surviving AL patients within 1‐year of nFLCr. Patients achieving early OR within 1 year of nFLCr had superior OS compared with those who despite obtaining nFLCr did not achieve early OR. We further evaluated factors predicting OR and OS among patients achieving nFLCr. Higher values of dFLC (involved–uninvolved) at diagnosis predict OR, and early OR predicts improved OS following successful hematologic therapy in AL. Am. J. Hematol. 90:181–186, 2015. © 2014 Wiley Periodicals, Inc.

Abstract CD40 and BAFFR signaling play important roles in B cell proliferation and Ig production. In this study, we found that B cells from mice with deletion of Dbc1 gene (Dbc1−/−) show elevated proliferation, and IgG1 and IgA production upon in vitro CD40 and BAFF, but not BCR and LPS stimulation, indicating that DBC1 inhibits CD40/BAFF-mediated B cell activation in a cell-intrinsic manner. Microarray analysis and chromatin immunoprecipitation experiments reveal that DBC1 inhibits B cell function by selectively suppressing the transcriptional activity of alternative NF-κB members RelB and p52 upon CD40 stimulation. As a result, when immunized with nitrophenylated-keyhole limpet hemocyanin, Dbc1−/− mice produce significantly increased levels of germinal center B cells, plasma cells, and Ag-specific Ig. Finally, loss of DBC1 in mice leads to higher susceptibility to experimental autoimmune myasthenia gravis. Our study identifies DBC1 as a novel regulator of B cell activation by suppressing the alternative NF-κB pathway.

Background Atrial fibrillation ( AF ) is associated with increased risk of hospitalization. Little is known about the impact of AF on utilization of noninpatient health care or about sex or race differences in AF ‐related utilization. We examined rates of inpatient and outpatient utilization by AF status in the Atherosclerosis Risk in Communities study. Methods and Results Participants with incident AF enrolled in fee‐for‐service Medicare for at least 12 continuous months between 1991 and 2009 (n=932) were matched on age, sex, race and field center with up to 3 participants without AF (n=2729). Healthcare utilization was ascertained from Medicare claims and classified by primary International Classification of Diseases, ninth revision code. The average annual numbers of days hospitalized were 13.2 (95% CI 11.6 to 15.0) and 2.8 (95% CI 2.5 to 3.1) for those with and without AF , respectively. The corresponding numbers of annual outpatient claims were 53.3 (95% CI 50.5 to 56.3) and 22.9 (95% CI 22.1 to 23.8) for those with and without AF , respectively. Most utilization among AF patients was attributable to non‐ AF conditions. The adjusted rate ratio for annual days hospitalized for other cardiovascular disease–related reasons was 4.58 (95% CI : 3.41 to 6.16) for those with AF versus those without AF . The association between AF and healthcare utilization was similar among men and women and among white and black participants. Conclusions Participants with AF had considerably greater healthcare utilization, and the difference in utilization for other cardiovascular disease –related reasons was substantial. In addition to rate or rhythm treatment, AF management should focus on the accompanying cardiovascular comorbidities.

Abstract Purpose: To evaluate the relevance between lumican expression patterns and the clinical course of patients with pancreatic ductal adenocarcinoma (PDAC), and to investigate the role of lumican in PDAC progression. Experimental Design: One hundred thirty-one patient tumors were chosen for tissue microarray staining, and Cox regression analysis was used to test the associations between lumican expression and clinical, pathologic, and oncologic outcomes in all patients. Primary PDAC cells and recombinant human lumican protein were used to establish a working model to mimic the in vivo interactions between stromal lumican and PDAC cells. Using this model, we tested the effects of lumican on EGFR signaling via Akt and hypoxia-inducible factor-1α (HIF1α) and its subsequent influence on glucose consumption, lactate production, intracellular ATP, and apoptotic cell death. Results: Lumican was present in the stroma surrounding PDAC cells in roughly one-half of primary tumors and the direct xenografts. Patients with stromal lumican were associated with a profound reduction in metastatic recurrence after surgery and 3-fold longer survival than patients without stromal lumican. In PDAC cells, extracellular lumican reduced EGFR expression and phosphorylation through enhanced dimerization and internalization of EGFR and the resultant inhibition of Akt kinase activity. Lumican also reduced HIF1α expression and activity via Akt. PDAC cells with enhanced HIF1α activity were resistant to lumican-induced inhibition of glucose consumption, lactate production, intracellular ATP, and apoptosis. Conclusions: There is a positive association between stromal lumican in primary PDAC tumors and prolonged survival after tumor resection. Lumican plays a restrictive role in EGFR-expressing pancreatic cancer progression. Clin Cancer Res; 20(24); 6529–40. ©2014 AACR.

Abstract Phosphaturic mesenchymal tumours ( PMTs ) are uncommon soft tissue and bone tumours that typically cause hypophosphataemia and tumour‐induced osteomalacia ( TIO ) through secretion of phosphatonins including fibroblast growth factor 23 ( FGF23 ). PMT has recently been accepted by the World Health Organization as a formal tumour entity. The genetic basis and oncogenic pathways underlying its tumourigenesis remain obscure. In this study, we identified a novel FN1–FGFR1 fusion gene in three out of four PMTs by next‐generation RNA sequencing. The fusion transcripts and proteins were subsequently confirmed with RT‐PCR and western blotting. Fluorescence in situ hybridization analysis showed six cases with FN1–FGFR1 fusion out of an additional 11 PMTs . Overall, nine out of 15 PMTs (60%) harboured this fusion. The FN1 gene possibly provides its constitutively active promoter and the encoded protein's oligomerization domains to overexpress and facilitate the activation of the FGFR1 kinase domain. Interestingly, unlike the prototypical leukaemia‐inducing FGFR1 fusion genes, which are ligand‐independent, the FN1–FGFR1 chimeric protein was predicted to preserve its ligand‐binding domains, suggesting an advantage of the presence of its ligands (such as FGF23 secreted at high levels by the tumour) in the activation of the chimeric receptor tyrosine kinase, thus effecting an autocrine or a paracrine mechanism of tumourigenesis. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The serum immunoglobulin free light chain (FLC) assay quantitates free kappa (κ) and lambda (λ) light chains. FLC elevations in patients with diffuse large B‐cell lymphoma (DLBCL), Hodgkin lymphoma (HL), and chronic lymphocytic leukemia (CLL) are associated with an inferior survival. These increases in FLC can be monoclonal (as in myeloma) or polyclonal. The goal was to estimate the frequency of these elevations within distinct types of B‐cell and T‐cell non‐Hodgkin lymphoma (NHL) and whether the FLC measurements are associated with event‐free survival (EFS). We studied serum for FLC abnormalities using normal laboratory reference ranges to define an elevated κ or λ FLC. Elevations were further classified as polyclonal or monoclonal. Four hundred ninety‐two patients were studied: 453 B‐cell and 34 T‐cell NHL patients. Twenty‐nine % (142/453) of patients had an elevated FLC of which 10% were monoclonal elevations. Within B‐cell NHL, FLC abnormalities were most common in lymphoplasmacytic (79%), mantle cell (68%), and lymphomas of mucosa associated lymphoid tissue (31%); they were least common in follicular (15%). The hazard ratio (HR) for EFS in all patients was 1.41 (95% CI; 1.11–1.81); in all B‐cell NHL the HR was 1.44 (95% CI 1.11–1.96); in all T‐cell NHL the HR was 1.17 (95% CI 0.55–2.49). FLC abnormalities predicted an inferior OS (HR = 2.75, 95% CI: 1.93–3.90, P < 0.0001). The serum FLC assay is useful for prognosis in both B‐cell and T‐cell types of NHL. In B‐cell NHL further discrimination between a monoclonal and polyclonal elevation may be helpful and should be analyzed in prospective clinical trials. Am. J. Hematol. 89:1116–1120, 2014. © 2014 Wiley Periodicals, Inc.