Key Words: atherosclerosis Ⅲ immunity Ⅲ tumor necrosis factor receptor superfamily 14 Ⅲ matrix metalloproteinases Ⅲ foam cells T umor necrosis factor (TNF)-␣ and CD40L play pivotal roles in the atherogenesis. TNF-␣ was found to be expressed in atherosclerotic plaques, 1,2 and TNF-␣ was also found to be colocalized with foam cells, smooth muscle cells (SMCs), 3,4 and mast cells. 5 CD40, a member of the TNF receptor superfamily (TNFRSF), is an integral membrane protein found on the surface of B lymphocytes, dendritic cells, hematopoietic progenitor cells, epithelial cells, and carcinomas. CD40 binds to a ligand (CD40L) which is a member of the TNF superfamily (TNFSF). 6 In atherosclerotic plaques, the expression of CD40L in T cells and the coexpression of CD40 and CD40L in vascular endothelial cells, SMCs, and macrophages were detected. 7 The interaction between CD40 and CD40L, similar to the interaction between TNF-␣ and its receptor, elicits diverse biological responses involved in atherosclerosis, such as the secretion of proinflammatory cytokines and matrix metalloproteinases (MMPs), and the expression of adhesion molecules and tissue factor. 8,9 These responses are known to make the plaque unstable. See page 1873Recently, the list of molecules belonging to TNFRSF has expanded significantly. TNFRSF14 (HVEM/HveA/ LIGHTR/TR2/ATAR) was initially identified as a cellular coreceptor for herpes simplex virus entry, hence, the name HVEM (herpes virus entry mediator, later named HveA [herpes virus entry protein A]). 10 TNFRSF14 has a wide tissue distribution and is prominently expressed by cells in lymphoid tissue, such as the spleen, and on peripheral blood leukocytes. TNFRSF14 mRNA was detected on resting and activated CD4ϩ and CD8ϩ T cells, on CD19ϩ B cells, and on monocytes. 14 We hypothesized that TNFRSF14, like the CD40/CD40L system, has a role in atherosclerosis. We analyzed the expression of TNFRSF14 in atherosclerotic plaques and the expression of proatherogenic cytokines and MMPs after stimulation of TNFRSF14 in THP-1 cells. Methods Histological AnalysisFor immunohistochemical analysis, carotid endarterectomy specimens were obtained from 13 patients, aged 63 to 81 years, who underwent the surgery at Samsung Seoul Hospital. The study was approved by an institutional review committee, and the subjects gave informed consent. Atherosclerotic plaque specimens were washed with saline and embedded in OCT (Miles Laboratories) to make frozen sections. Standard 5-m sections were stained by use of the LSAB kit (DAKO) according to the manual provided by the manufacturer. Double staining of CD68 and TNFRSF14 was performed by using an Animal Research Kit (DAKO) according to the manual provided by the manufacturer. Cell CultureHuman monocytic leukemia THP-1 cells 15 were obtained from the American Type Culture Collection. For the analysis of peripheral blood monocytes, whole blood was collected either in heparin Vacutainer or CTAD Diatubes (Becton Dickinson/Diagnostica Stago) containing dipyridamole and theophylline to pr...

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Inflammation-mediated endothelial cell (EC) dysfunction likely contributes to the pathogenesis of several vascular diseases including atherosclerosis. We found that stimulation of human umbilical vein ECs with lipopolysaccharide induced secretion of cyclophilin (CyPA) an intracellular protein belonging to the immunophilin family. We then found that when added exogenously CyPA has direct effects on ECs in vitro. At low concentrations (10 to 100 ng/ml) CyPA increased EC proliferation, migration, invasive capacity, and tubulogenesis. Gelatin zymography indicated increased secretion of active matrix metalloproteinase-2, a mediator of cell migration and angiogenesis. At high concentrations (eg, 2 g/ml) CyPA had opposite effects, decreasing EC migration and viability, possibly in relation to induction of Toll-like receptor-4 expression, detected by immunocytochemistry and flow cytometry. In vivo CyPA expression was not detectable in the luminal ECs of normal mouse carotid arteries but was rapidly induced after systemic lipopolysaccharide injection. In an experimental mouse model of atherosclerosis, CyPA expression was detected in the ECs of neocapillaries of carotid artery lesions, supporting its association with pathological angiogenesis suggested by our in vitro results. In conclusion, we found that CyPA has a biphasic activity on ECs in vitro and is up-regulated in vivo in ECs under pathological states. Our results suggest that CyPA is a novel paracrine and autocrine modulator of EC functions in immune-mediated vascular disease.

Objective Much of the genetic basis for Alzheimer disease (AD) is unexplained. We sought to identify novel AD loci using a unique family-based approach that can detect robust associations with infrequent variants (minor allele frequency <0.10). Methods We conducted a genome-wide association study in the Framingham Heart Study (FHS) (discovery) and NIA-LOAD (replication) family-based cohorts using an approach that accounts for family structure and calculates a risk score for AD as the outcome. Links between the most promising gene candidate and AD pathogenesis were explored in silico as well as experimentally in cell-based models and in human brain. Results Genome-wide significant association was identified with a PLXNA4 SNP (rs277470) located in a region encoding the semaphorin-3A (SEMA3A) binding domain (meta-analysis p value [meta-P]=4.1×10−8). A test for association with the entire region was also significant (meta-P=3.2×10−4). Transfection of SH-SY5Y cells or primary rat neurons with full-length PLXNA4 (TS1) increased tau phosphorylation when stimulated by SEMA3A. The opposite effect was observed when transfected with shorter isoforms (TS2 and TS3). However, transfection of any isoform into HEK293 cells stably expressing APP did not result in differential effects on APP processing or Aβ production. Late-stage AD cases (n=9) compared to controls (n=5) had 1.9-fold increased expression of TS1 in cortical brain tissue (P=1.6×10−4). Expression of TS1 was significantly correlated with the Clinical Dementia Rating score (ρ=0.75, P=2.2×10−4), plaque density (ρ=0.56, P=0.01) and Braak stage (ρ=0.54, P=0.02). Interpretation Our results indicate that PLXNA4 has a role in AD pathogenesis through isoform-specific effects on tau phosphorylation.