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Background: Endothelial cell responses during inflammation are heterogeneous and key for selectivity in how leukocytes hone in on specific sites and why vascular diseases are highly bed specific. However, mechanisms for this specificity remain unclear., Methods and Results: Here, we exposed human endothelial cells isolated from 5 systemic arterial beds from 1 donor (to overcome donor-to-donor genetic/epigenetic differences), the umbilical vein, and pulmonary microvasculature to TNF-α, LPS, and IL-1β and assessed acute (ERK1/2 and p65) and chronic (ICAM-1, VCAM-1 total and surface expression) signaling responses and assessed changes in surface N-glycans and monocyte adhesion. Significant diversity in responses was evident by disparate changes in ERK1/2 and p65 NF-κB phosphorylation, which varied up to 5-fold between different cells and in temporal and magnitude differences in ICAM-1 and VCAM-1 expression (maximal VCAM-1 induction typically being observed by 4 hours, whereas ICAM-1 expression was increased further at 24 hours relative to 4 hours). N-glycan profiles both basally and with stimulation were also bed specific, with hypoglycosylated N-glycans correlating with increased THP-1 monocyte adhesion. Differences in surface N-glycan expression tracked with dynamic up- or downregulation of α-mannosidase activity during inflammation., Conclusions: These results demonstrate a critical role for the vascular bed of origin in controlling endothelial responses and function to inflammatory stimuli and suggest that bed-specific expression of N-linked sugars may provide a signature for select leukocyte recruitment.

Hyperglycemia is considered to be the major cause of microvascular complications of diabetes. Growing evidence highlights the importance of hyperglycemia-mediated inflammation in the initiation and progression of microvascular complications in type 1 diabetes. We hypothesize that lack of proinsulin C-peptide and lack of its anti-inflammatory properties contribute to the development of microvascular complications. Evidence gathered over the past 20 years shows that C-peptide is a biologically active peptide in its own right. It has been shown to reduce formation of reactive oxygen species and nuclear factor-κB activation induced by hyperglycemia, resulting in inhibition of cytokine, chemokine and cell adhesion molecule formation as well as reduced apoptotic activity. In addition, C-peptide stimulates and induces the expression of both Na⁺, K⁺-ATPase and endothelial nitric oxide synthase. Animal studies and small-scale clinical trials in type 1 diabetes patients suggest that C-peptide replacement combined with regular insulin therapy exerts beneficial effects on kidney and nerve dysfunction. Further clinical trials in patients with microvascular complications including measurements of inflammatory markers are warranted to explore the clinical significance of the aforementioned, previously unrecognized, C-peptide effects., (Copyright © 2013 John Wiley & Sons, Ltd.)

Cerebral malaria is a devastating complication of Plasmodium falciparum infection. Its pathogenesis is complex, involving both parasite- and immune-mediated events. CD8(+) T cells play an effector role in murine experimental cerebral malaria (ECM) induced by Plasmodium berghei ANKA (PbA) infection. We have identified a highly immunogenic CD8 epitope in glideosome-associated protein 50 that is conserved across rodent malaria species. Epitope-specific CD8(+) T cells are induced during PbA infection, migrating to the brain just before neurological signs manifest. They are functional, cytotoxic and can damage the blood-brain barrier in vivo. Such CD8(+) T cells are also found in the brain during infection with parasite strains/species that do not induce neuropathology. We demonstrate here that PbA infection causes brain microvessels to cross-present parasite antigen, while non-ECM-causing parasites do not. Further, treatment with fast-acting anti-malarial drugs before the onset of ECM reduces parasite load and thus antigen presentation in the brain, preventing ECM death. Thus our data suggest that combined therapies targeting both the parasite and host antigen-presenting cells may improve the outcome of CM patients., (© 2013 The Authors. Published by John Wiley and Sons, Ltd on behalf of EMBO.)

Background: Carcinomas of the salivary glands are uncommon and morphologically a diverse group of malignancies. To evaluate the prognostic value of CD34 immunostaining of the vessels in adenoid cystic carcinoma (AdCC) and mucoepidermoid carcinoma (MEC), an automated image analysis method was used., Method: In a nationwide study, covering salivary gland cancer (SGC) patients in Finland 1991-1996, 37 AdCC and 18 MEC patients (M 25, F 30, age 25-90, mean 63) were included. In addition to clinical characteristics the size, shape, staining intensity and vessel density in CD34 immunostained histologic samples were measured., Results: Altogether 4433 vessels were measured from AdCC and 2615 from MEC tumor. Of the total tumor vessels measured, 2651 were from patients who deceased with disease (Group I) and 4397 were from specimens derived from those who did not die of disease (Group II) during the 10-year follow-up. The staining intensity was significantly higher in MEC than in AdCC tumor (P = 0.0005). In MEC, the Group I patients had a higher staining intensity among high-grade patients compared with patients with low grade disease, whereas the tumors in Group II had a lower staining intensity among the high-grade compared with the low grade tumors (P = 0.018). A higher vessel density was found in patients with MEC in group II compared with group I (P = 0.017)., Conclusions: The staining intensity of CD34 positive vessels in MEC was higher than in AdCC. In MEC, higher staining intensity of vessels in high-grade tumors and lower vessel density in all MEC patients, predicted poor survival.

Background: Glypican-3 (GPC3) is frequently upregulated in hepatocellular carcinoma (HCC). Analysis of GPC3-deficient mice implies GPC3 involvement in macrophage-lineage cells., Aim: In this study, we first assessed the association of GPC3 expression with the macrophage population in liver tissues from 30 HCC patients using immunohistochemistry., Methods: The GPC3 expression was categorized into three patterns - one with GPC3-negative staining and two with GPC3-positive staining (one with unclear membrane staining and one with clear membrane staining, designated GPC3+/C). The number of macrophages that were stained with resident macrophage (rMvarphi) or pan-macrophage (pMvarphi) markers was counted for each GPC3 expression pattern., Results: GPC3 immunoreactivity was observed in 76.7% of the HCC specimens. No significant differences were observed in the number of rMvarphi marker-positive cells among the three expression patterns. In contrast, the GPC3+/C pattern showed a significantly higher number of pMvarphi-positive cells compared with the other two patterns, most of which tended to take on the morphology of migrating macrophages. A second experiment conducted to compare macrophage infiltration between the xenograft tissues of a GPC3-transfected HCC cell line and its parent GPC3-nonexpressing cell line revealed that the increase in macrophages was stimulated by membrane expression of GPC3., Conclusion: The observations suggest that the increased macrophages in the GPC3+/C pattern are likely to be recruited macrophages, not resident macrophages, and that the expression of GPC3 in the membrane is involved in macrophage recruitment.

Objective: Although enterobacteria are implicated in intestinal immune response, there has been no report on how intraluminal pathogens affect lymphocyte recruitment. The aim of this study was to determine how the presence of intestinal flora affects lymphocyte migration to intestine under physiological and lipopolysaccharide (LPS)-induced inflammatory conditions., Methods: Interaction of T-cells with ileal microvessels was monitored by using an intravital microscope in mice under germ-free (GF) and specific pathogen-free (SPF) conditions. LPS was administered into either the peritoneal cavity or duodenum before lymphocyte injection., Results: Adherence of T-cells was greater in SPF than in GF mice, indicating that the presence of enterobacteria upregulated migration under physiological conditions. Intraperitoneally administered LPS significantly increased the adherence of T-cells in both GF and SPF mice accompanied by the expression of adhesion molecules and proinflammatory cytokines. However, intraluminally administered LPS did not enhance the adherence of T-cells in SPF mice. A significant induction of increase in mRNA expression of IRAK-M, a negative regulator of TLR4 signaling, and transforming growth factor beta (TGF-beta), a regulatory cytokine, was observed in SPF mice after luminal LPS treatment., Conclusions: Tolerance to intraluminally administered LPS in the lymphocyte recruitment process was induced by enterobacteria, possibly via the induction of IRAK-M and TGF-beta.

Background: Some severe asthma patients are characterized by elevated levels of tumor necrosis factor alpha (TNF-alpha) and neutrophilic inflammation in the airways. Although such phenotypic changes in asthma might contribute to corticosteroid refractoriness, the role of TNF-alpha in the process remains unclear. TNF-alpha exerts its biological effects mainly by acting on the vascular endothelium, and thereby upregulates leukocyte recruitment into inflamed tissues. The aim of this study was to investigate the effects of dexamethasone (DEX) on the TNF-alpha-mediated responses of human microvascular endothelial cells from lung blood vessels (HMVEC-LBl) in vitro., Methods: HMVEC-LBl were cultured with TNF-alpha in the presence and absence of DEX. The effects of DEX on various TNF-alpha-mediated responses, such as the expressions of chemokines and cellular adhesion molecules, leukocyte adhesion were determined., Results: TNF-alpha significantly induced growth-related oncogene alpha (GRO-alpha), interleukin 8 (IL-8), regulated on activation, normal T-cell expressed and secreted (RANTES) and interferon-inducible protein 10 (IP-10) productions and cell surface expressions of intracellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) on HMVEC-LBl. TNF-alpha-induced GRO-alpha and IL-8 were slightly attenuated by DEX treatment (reaches to 89% and 79%, respectively), whereas expressions of IP-10, ICAM-1 and VCAM-1 were significantly enhanced by the same treatment (up to 172%, 152% and 139%, respectively). Correspondingly, in vitro adhesion of eosinophils and neutrophils to TNF-alpha-treated HMVEC-LBl were significantly enhanced by DEX., Conclusions: Some proinflammatory effects of DEX, a corticosteroid, were found in TNF-alpha-mediated in vitro reactions of pulmonary microvascular endothelial cells, i.e. chemokine productions and leukocyte adhesion. These in vitro results may explain, at least in part, the corticosteroid refractoriness accompanied by a marked increase in TNF-alpha production that is seen in severe asthmatic patients.

Objective: To identify in patients with Raynaud's phenomenon (RP) independent markers that predict progression to definite systemic sclerosis (SSc) and to determine in patients with progression to SSc the type and sequence of microvascular damage and its relationship to SSc-specific autoantibodies., Methods: Consecutive patients referred for evaluation of RP who had no definite connective tissue disease were evaluated for microvascular damage by nailfold capillary microscopy (NCM) and for anticentromere (anti-CENP-B), anti-Th/To, anti-topoisomerase I, and anti-RNA polymerase III (anti-RNAP III) autoantibodies by specific assays. Patients were studied prospectively., Results: Of the 586 patients who were followed up for 3,197 person-years, 74 (12.6%) developed definite SSc. A characteristic sequence of microvascular damage was identified, starting with enlarged capillaries, followed by capillary loss, and then by capillary telangiectases. Definite SSc was diagnosed in close temporal relationship to capillary loss. Enlarged capillaries, capillary loss, and SSc-specific autoantibodies independently predicted definite SSc. Anti-CENP-B and anti-Th/To antibodies predicted enlarged capillaries; these autoantibodies and anti-RNAP III predicted capillary loss. Each autoantibody was associated with a distinct time course of microvascular damage. At followup, 79.5% of patients with 1 of these autoantibodies and abnormal findings on NCM at baseline had developed definite SSc. Patients with both baseline predictors were 60 times more likely to develop definite SSc. The data validated the proposed criteria for early SSc., Conclusion: In RP evolving to definite SSc, microvascular damage is dynamic and sequential, while SSc-specific autoantibodies are associated with the course and type of capillary abnormalities. Abnormal findings on NCM at baseline together with an SSc-specific autoantibody indicate a very high probability of developing definite SSc, whereas their absence rules out this outcome.