T Follicular Helper Cell-Germinal Center B Cell Interaction Strength Regulates Entry into Plasma Cell or Recycling Germinal Center Cell Fate.

Higher- or lower-affinity germinal center (GC) B cells are directed either to plasma cell or GC recycling, respectively; however, how commitment to the plasma cell fate takes place is unclear. We found that a population of light zone (LZ) GC cells, Bcl6loCD69hi expressing a transcription factor IRF4 and higher-affinity B cell receptors (BCRs) or Bcl6hiCD69hi with lower-affinity BCRs, favored the plasma cell or recycling GC cell fate, respectively. Mechanistically, CD40 acted as a dose-dependent regulator for Bcl6loCD69hi cell formation. Furthermore, we found that expression of intercellular adhesion molecule 1 (ICAM-1) and signaling lymphocytic activation molecule (SLAM) in Bcl6loCD69hi cells was higher than in Bcl6hiCD69hi cells, thereby affording more stable T follicular helper (Tfh)-GC B cell contacts. These data support a model whereby commitment to the plasma cell begins in the GC and suggest that stability of Tfh-GC B cell contacts is key for plasma cell-prone GC cell formation.

Anti-Inflammatory Activity of Ferula assafoetida Oleo-Gum-Resin (Asafoetida) against TNF-α-Stimulated Human Umbilical Vein Endothelial Cells (HUVECs).

Inflammation is the body's biological reaction to endogenous and exogenous stimuli. Recent studies have demonstrated several anti-inflammatory properties of Ferula species. In this paper, we decided to study the anti-inflammatory effect of ethanolic extract of Ferula assafoetida oleo-gum-resin (asafoetida) against TNF-α-stimulated human umbilical vein endothelial cells (HUVECs). HUVECs were cultured in a flat-bottom plate and then treated with ethanolic extract of asafoetida (EEA, 0-500 µg/ml) and TNF-α (0-100 ng/ml) for 24 h. We used the MTT test to assess cell survival. In addition, the LC-MS analysis was performed to determine the active substances. HUVECs were pretreated with EEA and then induced by TNF-α. Intracellular reactive oxygen species (ROS) and adhesion of peripheral blood mononuclear cells (PBMCs) to HUVECs were evaluated with DCFH-DA and CFSE fluorescent probes, respectively. Gene expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin and surface expression of ICAM-1 protein were measured using real-time PCR and flow cytometry methods, respectively. While TNF-α significantly increased intracellular ROS formation and PBMC adhesion to TNF-α-induced HUVECs, the pretreatment of HUVECs with EEA (125 and 250 µg/ml) significantly reduced the parameters. In addition, EEA pretreatment decreased TNF-α-induced mRNA expression of VCAM-1 and surface protein expression of ICAM-1 in the target cells. Taken together, the results indicated that EEA prevented ROS generation, triggered by TNF-α, and inhibited the expression of VCAM-1 and ICAM-1, leading to reduced PBMC adhesion. These findings suggest that EEA can probably have anti-inflammatory properties.

Deoxycholic acid enhancement of lymphocyte migration through direct interaction with the intestinal vascular endothelium.

BACKGROUND AND AIM: The small intestine plays a central role in gut immunity, and enhanced lymphocyte migration is involved in the pathophysiology of various enteropathy. Bile acid (BA) is closely related to lipid metabolism and gut microbiota and essential for gut homeostasis. However, the effects of BA on gut immunity have not been studied in detail, especially on the small intestine and lymphocyte migration. Therefore, we aimed to investigate the effect of BA on small intestinal lymphocyte microcirculation. METHODS: The effect of deoxycholic acid (DCA), taurocholic acid (tCA), or cholic acid (CA) on the indomethacin (IND)-induced small intestinal enteropathy in mice was investigated. Lymphocyte movements were evaluated after exposure to BA using intravital microscopy. The effects of BA on surface expression of adhesion molecules on the vascular endothelium and lymphocytes through BA receptors were examined in vitro. RESULTS: IND-induced small intestinal enteropathy was histologically aggravated by DCA treatment alone. The expression of adhesion molecules ICAM-1 and VCAM-1 was significantly enhanced by DCA. Exposure to DCA increased lymphocyte adhesion in the microvessels of the ileum, which was partially blocked by anti-α4ß1 integrin antibody in vivo. The expression of ICAM-1 and VCAM-1 was significantly enhanced by DCA in vitro, which was partially suppressed by the sphingosine-1-phosphate receptor 2 (S1PR2) antagonist. The S1PR2 antagonist significantly ameliorated IND-induced and DCA-exaggerated small intestinal injury. CONCLUSION: DCA exacerbated IND-induced small intestinal enteropathy. DCA directly acts on the vascular endothelium and enhances the expression levels of adhesion molecules partially via S1PR2, leading to enhanced small intestinal lymphocyte migration.

Dendrobium catenatum Lindl. Water Extracts Attenuate Atherosclerosis.

OBJECTIVES: Dendrobium catenatum Lindl. (DH) is a Chinese herbal medicine, which is often used to make tea to improve immunity in China. Rumor has it that DH has a protective effect against cardiovascular disease. However, it is not clear how DH can prevent cardiovascular disease, such as atherosclerosis (AS). Therefore, the purpose of this study is to study whether DH can prevent AS and the underlying mechanisms. METHODS: Zebrafish larvae were fed with high-cholesterol diet (HCD) to establish a zebrafish AS model. Then, we used DH water extracts (DHWE) to pretreat AS zebrafish. The plaque formation was detected by HE, EVG, and oil red O staining. Neutrophil and macrophage counts were calculated to evaluate the inflammation level. Reactive oxygen species (ROS) activity, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity in zebrafish were measured to reflect oxidative stress. The cholesterol accumulation and the levels of lipid, triglyceride (TG), and total cholesterol (TC) were measured to reflect lipid metabolism disorder. Then, parallel flow chamber was utilized to establish a low shear stress- (LSS-) induced endothelial cell (EC) dysfunction model. EA.hy926 cells were exposed to LSS (3 dyn/cm2) for 30 min and treated with DHWE. The levels of ROS, SOD, MDA, glutathione (GSH), and glutathiol (GSSG) in EA.hy926 cells were analysed to determine oxidative stress. The release of nitric oxide (NO), endothelin-1 (ET-1), and epoprostenol (PGI2) in EA.hy926 cells was measured to reflect EC dysfunction. The mRNA expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in EA.hy926 cells was detected to reflect EC dysfunction inflammation. RESULTS: The results showed that DHWE significantly reduced cholesterol accumulation and macrophage infiltration in early AS. Finally, DHWE significantly alleviate the lipid metabolism disorder, oxidative stress, and inflammation to reduce the plaque formation of AS zebrafish larval model. Meanwhile, we also found that DHWE significantly improved LSS-induced EC dysfunction and oxidative stress in vitro. CONCLUSION: Our results indicate that DHWE could be used as a prevention method to prevent AS.

Protective Effects of Thymoquinone, an Active Compound of Nigella sativa, on Rats with Benzo(a)pyrene-Induced Lung Injury through Regulation of Oxidative Stress and Inflammation.

Benzopyrene [B(a)P] is a well-recognized environmental carcinogen, which promotes oxidative stress, inflammation, and other metabolic complications. In the current study, the therapeutic effects of thymoquinone (TQ) against B(a)P-induced lung injury in experimental rats were examined. B(a)P used at 50 mg/kg b.w. induced lung injury that was investigated via the evaluation of lipid profile, inflammatory markers, nitric oxide (NO), and malondialdehyde (MDA) levels. B(a)P also led to a decrease in superoxide dismutase (SOD) (34.3 vs. 58.5 U/mg protein), glutathione peroxidase (GPx) (42.4 vs. 72.8 U/mg protein), catalase (CAT) (21.2 vs. 30.5 U/mg protein), and total antioxidant capacity compared to normal animals. Treatment with TQ, used at 50 mg/kg b.w., led to a significant reduction in triglycerides (TG) (196.2 vs. 233.7 mg/dL), total cholesterol (TC) (107.2 vs. 129.3 mg/dL), and inflammatory markers and increased the antioxidant enzyme level in comparison with the group that was administered B(a)P only (p < 0.05). B(a)P administration led to the thickening of lung epithelium, increased inflammatory cell infiltration, damaged lung tissue architecture, and led to accumulation of collagen fibres as studied through haematoxylin and eosin (H&E), Sirius red, and Masson's trichrome staining. Moreover, the recognition of apoptotic nuclei and expression pattern of NF-κB were evaluated through the TUNEL assay and immunohistochemistry, respectively. The histopathological changes were found to be considerably low in the TQ-treated animal group. The TUNEL-positive cells increased significantly in the B(a)P-induced group, whereas the TQ-treated group showed a decreased apoptosis rate. Significantly high cytoplasmic expression of NF-κB in the B(a)P-induced group was seen, and this expression was prominently reduced in the TQ-treated group. Our results suggest that TQ can be used in the protection against benzopyrene-caused lung injury.

Human T-Cell Leukemia Virus Type 1 (HTLV-1) bZIP Factor Upregulates the Expression of ICAM-1 To Facilitate HTLV-1 Infection.

Human T-cell leukemia virus type 1 (HTLV-1) causes multiple pathological effects, ranging from a form of leukemia to a spectrum of inflammation-mediated diseases. These diseases arise from one or several infected CD4+ T cells among thousands acquiring proliferation and survival advantages and ultimately becoming pathogenic. Given the low incidence of HTLV-1-associated diseases among carriers, such cellular evolutionary processes appear to occur rarely. Therefore, infectious spread of HTLV-1 within the T-cell population may be one underlying factor influencing disease development. Free HTLV-1 virions are poorly infectious, so infection of T cells relies on direct contact between infected and target cells. Following contact, virions pass to target cells through a virological synapse or cellular conduits or are transferred to target cells within an extracellular matrix. Lymphocyte functioning antigen 1 (LFA-1) on the surface of the target cell engaging with its ligand, ICAM-1, on the surface of the infected cell (effector cell) initiates and stabilizes cell-cell contact for infection. We found that stable expression of an HTLV-1 accessory protein, HTLV-1 bZIP factor (HBZ), in Jurkat T cells increases homotypic aggregation. This phenotype was attributed to elevated ICAM-1 expression in the presence of HBZ. Using a single-cycle replication-dependent luciferase assay, we found that HBZ expression in Jurkat cells (used as effector cells) increases HTLV-1 infection. Despite this effect, HBZ could not replace the critical infection-related functions of the HTLV-1 regulatory protein Tax. However, in HTLV-1-infected T cells, knockdown of HBZ expression did lead to a decrease in infection efficiency. These overall results suggest that HBZ contributes to HTLV-1 infectivity.IMPORTANCE Human T-cell leukemia virus type 1 (HTLV-1) causes a variety of diseases, ranging from a fatal form of leukemia to immune-mediated inflammatory diseases. These diseases occur rarely, arising from one or a small subset of virally infected cells infrequently evolving into a pathogenic state. Thus, the process of HTLV-1 cell-to-cell transmission within the host helps influence the probability of disease development. HTLV-1 primarily infects T cells and initially spreads within this cell population when virally infected T cells dock to uninfected target T cells and then transfer HTLV-1 virus particles to the target cells. Here we found that the viral protein HTLV-1 bZIP factor (HBZ) promotes infectivity. HBZ accomplishes this task by increasing the surface abundance of a cellular adhesion protein known as intercellular adhesion molecule 1 (ICAM-1), which helps initiate and stabilize contact (docking) between infected and target T cells. These results define a novel and unexpected function of HBZ, diverging from its defined functions in cellular survival and proliferation.

Gliclazide attenuates acetic acid-induced colitis via the modulation of PPARγ, NF-κB and MAPK signaling pathways.

Ulcerative Colitis is a universal autoimmune disease with high incidence rates worldwide. It is characterized by the existence of many other concurrent immune-associated ailments, including diabetes. The used strategies for the management of this highly costing and complicated disease face great challenges. Therefore, the urge for new medication with fewer side effects and high efficacy is growing. The peroxisome proliferator-activated receptor-gamma (PPARγ) and nuclear factor Kappa-B (NF-κB) can be considered as crucial targets for the treatment of ulcerative colitis. Several studies reported the antioxidants, anti-inflammatory, and antiapoptotic actions of gliclazide and evaluated its cardioprotective and renoprotective effects. However, its impact on ulcerative colitis has never been investigated. This study delineated the effect of gliclazide administration on ulcerative colitis induced by acetic acid in rats and the underlying molecular mechanisms. Gliclazide (10 mg/kg; p.o) prominently decreased colon tissue injury as assessed by the histopathological analysis as well as myeloperoxidase, and intercellular adhesion molecule-1 levels. Gliclazide significantly alleviated the proinflammatory mediator, IL-6, promoted the anti-inflammatory cytokine, IL-10 and, withheld oxidative stress in the injured colon tissues. The protective effect of gliclazide was mediated through the upregulation of PPARγ and downregulation of NF-κB expression. The diminution of ulcerative colitis was also accompanied by an inhibition of the elevated activity and expression of mitogen-activated protein kinases and caspase-3 as assessed by Western blot and immunohistochemistry, respectively. Our findings spotlight, for the first time, the potential of the antidiabetic agent, gliclazide, to attenuate the experimentally induced ulcerative colitis. Therefore, gliclazide might be a propitious agent for the management of ulcerative colitis in diabetic patients.

The Roles of Lipoprotein in Psoriasis.

The association between psoriasis and cardiovascular disease risk has been supported by recent epidemiological data. Patients with psoriasis have an increased adjusted relative risk for myocardial infarction. As such, the cardiovascular risk conferred by severe psoriasis may be comparable to what is seen with other well-established risk factors, such as diabetes mellitus. Previous studies demonstrated that low-density lipoprotein (LDL) plays critical roles during atherogenesis. It may be caused by the accumulation of macrophages and lipoprotein in the vessel wall. Oxidized LDL (ox-LDL) stimulates the expression of adhesion molecules, such as ICAM-1 and VCAM-1, on endothelial cells and increases the attachment of mononuclear cells and the endothelium. Even though previous evidence demonstrated that psoriasis patients have tortuous and dilated blood vessels in the dermis, which results in the leakage of ox-LDL, the leaked ox-LDL may increase the expression of adhesion molecules and cytokines, and disturb the static balance of osmosis. Therefore, exploration of the relationship between hyperlipidemia and psoriasis may be another novel treatment option for psoriasis and may represent the most promising strategy.

Corticosterone Production during Repeated Social Defeat Causes Monocyte Mobilization from the Bone Marrow, Glucocorticoid Resistance, and Neurovascular Adhesion Molecule Expression.

Repeated social defeat (RSD) stress promotes the release of bone marrow-derived monocytes into circulation that are recruited to the brain, where they augment neuroinflammation and cause prolonged anxiety-like behavior. Physiological stress activates the sympathetic nervous system and hypothalamic-pituitary-adrenal gland (HPA) axis, and both of these systems play a role in the physiological, immunological, and behavioral responses to stress. The purpose of this study was to delineate the role of HPA activation and corticosterone production in the immunological responses to stress in male C57BL/6 mice. Here, surgical (adrenalectomy) and pharmacological (metyrapone) interventions were used to abrogate corticosterone signaling during stress. We report that both adrenalectomy and metyrapone attenuated the stress-induced release of monocytes into circulation. Neither intervention altered the production of monocytes during stress, but both interventions enhanced retention of these cells in the bone marrow. Consistent with this observation, adrenalectomy and metyrapone also prevented the stress-induced reduction of a key retention factor, CXCL12, in the bone marrow. Corticosterone depletion with metyrapone also abrogated the stress-induced glucocorticoid resistance of myeloid cells. In the brain, these corticosterone-associated interventions attenuated stress-induced microglial remodeling, neurovascular expression of the adhesion molecule intercellular cell adhesion molecule-1, prevented monocyte accumulation and neuroinflammatory signaling. Overall, these results indicate that HPA activation and corticosterone production during repeated social defeat stress are critical for monocyte release into circulation, glucocorticoid resistance of myeloid cells, and enhanced neurovascular cell adhesion molecule expression.SIGNIFICANCE STATEMENT Recent studies of stress have identified the presence of monocytes that show an exaggerated inflammatory response to immune challenge and are resistant to the suppressive effects of glucocorticoids. Increased presence of these proinflammatory monocytes has been implicated in neuropsychiatric symptoms and the development of chronic cardiovascular, autoimmune, and metabolic disorders. In the current study, we show novel evidence that corticosterone produced during stress enhances the release of proinflammatory monocytes from the bone marrow into circulation, augments their recruitment to the brain and the induction of a neuroinflammatory profile. Overproduction of corticosterone during stress is also the direct cause of glucocorticoid resistance, a key phenotype in individuals exposed to chronic stress. Inhibiting excess corticosterone production attenuates these inflammatory responses to stress.

Circulating plasmablasts are elevated and produce pathogenic anti-endothelial cell autoantibodies in idiopathic pulmonary arterial hypertension.

Idiopathic pulmonary arterial hypertension (IPAH) is a devastating pulmonary vascular disease in which autoimmune and inflammatory phenomena are implicated. B cells and autoantibodies have been associated with IPAH and identified as potential therapeutic targets. However, the specific populations of B cells involved and their roles in disease pathogenesis are not clearly defined. We aimed to assess the levels of activated B cells (plasmablasts) in IPAH, and to characterize recombinant antibodies derived from these plasmablasts. Blood plasmablasts are elevated in IPAH, remain elevated over time, and produce IgA autoantibodies. Single-cell sequencing of plasmablasts in IPAH revealed repertoires of affinity-matured antibodies with small clonal expansions, consistent with an ongoing autoimmune response. Recombinant antibodies representative of these clonal lineages bound known autoantigen targets and displayed an unexpectedly high degree of polyreactivity. Representative IPAH plasmablast recombinant antibodies stimulated human umbilical vein endothelial cells to produce cytokines and overexpress the adhesion molecule ICAM-1. Together, our results demonstrate an ongoing adaptive autoimmune response involving IgA plasmablasts that produce anti-endothelial cell autoantibodies in IPAH. These antibodies stimulate endothelial cell production of cytokines and adhesion molecules, which may contribute to disease pathogenesis. These findings suggest a role for mucosally-driven autoimmunity and autoimmune injury in the pathogenesis of IPAH.

Characterization of mesenchymal stem/stromal cells with lymphoid tissue organizer cell potential in tonsils from children.

Lymphoid tissue organizer (LTo) cells, identified in mouse and human embryos, are thought to be precursors of stromal cells in secondary lymphoid organs. Whether LTo cells are present in human adults, however remains unknown. We obtained 15 stromal cell lines from tonsils from children who underwent tonsillectomy, and studied the antigen phenotype of these tonsil stromal cell (TSC) lines by flow cytometry and RT-PCR. Cell lines met the minimal criteria proposed by the International Society for Cellular Therapy to define human mesenchymal stem/stromal cells (MSCs): plastic-adherent capacity; expression of CD73, CD90 and CD105, lack of CD45, CD19 and HLA-DR; and capacity to differentiate into adipocytes, osteoblasts and chondrocytes. Furthermore, our TSC lines exhibited an antigen phenotype and functional characteristics very similar to those seen in murine embryo LTo cells: they expressed chemokines CCL19, CCL21 and CXCL13, cytokines TRANCE and IL-7, and adhesion molecules ICAM-1, mucosal addressin cell adhesion molecule (MadCAM)-1 and VCAM-1. The expression of LTo cell-associated markers and functions were upregulated by lymphotoxin (LT)α1ß2 and TNF, two cytokines involved in the development and maturation of secondary lymphoid tissues. Our results show that TSCs are tonsil MSCs that differentiate into LTo-like cells in response to the effects of these cytokines.

Meningitic Escherichia coli-induced upregulation of PDGF-B and ICAM-1 aggravates blood-brain barrier disruption and neuroinflammatory response.

BACKGROUND: Blood-brain barrier (BBB) disruption and neuroinflammation are considered key mechanisms of pathogenic Escherichia coli invasion of the brain. However, the specific molecules involved in meningitic E. coli-induced BBB breakdown and neuroinflammatory response remain unclear. Our previous RNA-sequencing data from human brain microvascular endothelial cells (hBMECs) revealed two important host factors: platelet-derived growth factor-B (PDGF-B) and intercellular adhesion molecule-1 (ICAM-1), which were significantly upregulated in hBMECs after meningitic E. coli infection. Whether and how PDGF-B and ICAM-1 contribute to the development of E. coli meningitis are still unclear. METHODS: The western blot, real-time PCR, enzyme-linked immunosorbent assay, immunohistochemistry, and immunofluorescence were applied to verify the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in vivo and in vitro. Evan's blue assay and electric cell-substrate impedance sensing assay were combined to identify the effects of PDGF-B on BBB permeability. The CRISPR/Cas9 technology, cell-cell adhesion assay, and electrochemiluminescence assay were used to investigate the role of ICAM-1 in neuroinflammation subversion. RESULTS: We verified the significant induction of PDGF-B and ICAM-1 by meningitic E. coli in mouse as well as monolayer hBMECs models. Functionally, we showed that the increase of PDGF-B may directly enhance the BBB permeability by decreasing the expression of tight junction proteins, and the upregulation of ICAM-1 contributed to neutrophils or monocytes recruitment as well as neuroinflammation subversion in response to meningitic E. coli infection. CONCLUSIONS: Our findings demonstrated the roles of PDGF-B and ICAM-1 in mediating bacterial-induced BBB damage as well as neuroinflammation, providing new concepts and potential targets for future prevention and treatment of bacterial meningitis.

Anti-inflammatory property of quercetin through downregulation of ICAM-1 and MMP-9 in TNF-α-activated retinal pigment epithelial cells.

Quercetin is a flavonoid polyphenolic compound present in fruits and vegetables that has proven anti-inflammatory activity. The goal of the present investigation was to investigate the effects of quercetin on tumor necrosis factor-α (TNF-α)-induced inflammatory responses via the expression of ICAM-1 and MMP-9 in human retinal pigment epithelial cells (ARPE-19 cells). Real-time PCR, gelatin zymography, and Western blot analysis showed that TNF-α induced the expression of ICAM-1 and MMP-9 protein and mRNA in a time-dependent manner. These effects were attenuated by pretreatment of ARPE-19 cells with quercetin. Quercetin inhibited the TNF-α-induced phosphorylation of PKCδ, JNK1/2, ERK1/2. Quercetin, rottlerin, SP600125 and U0126 attenuated TNF-α-stimulated c-Jun phosphorylation and AP-1-Luc activity. Pretreatment with quercetin, rottlerin, SP600125, or Bay 11-7082 attenuated TNF-α-induced NF-κB (p65) phosphorylation, translocation and RelA/p65-Luc activity. TNF-α significantly increased MMP-9 promoter activity and THP-1 cell adherence, and these effects were attenuated by pretreatment with quercetin, rottlerin, SP600125, U0126, tanshinone IIA or Bay 11-7082. These results suggest that quercetin attenuates TNF-α-induced ICAM-1 and MMP-9 expression in ARPE-19 cells via the MEK1/2-ERK1/2 and PKCδ-JNK1/2-c-Jun or NF-κB pathways.

4-Hydroxypanduratin A and Isopanduratin A Inhibit Tumor Necrosis Factor α-Stimulated Gene Expression and the Nuclear Factor κB-Dependent Signaling Pathway in Human Lung Adenocarcinoma A549 Cells.

Tumor necrosis factor α (TNF-α), a pro-inflammatory cytokine, regulates inflammatory and immune responses by up-regulating gene expression in a manner that is dependent on the transcription factor nuclear factor κB (NF-κB). In the present study, we found that 4-hydroxypanduratin A and isopanduratin A, constituents of the rhizomes of Boesenbergia pandurata, inhibited the TNF-α-stimulated up-regulation of intercellular adhesion molecule-1 (ICAM-1) in human lung adenocarcinoma A549 cells. 4-Hydroxypanduratin A and isopanduratin A also reduced ICAM-1 mRNA expression and NF-κB-responsive luciferase activity in TNF-α-stimulated A549 cells. Moreover, 4-hydroxypanduratin A and isopanduratin A prevented the TNF-α-stimulated translocation of the NF-κB subunit p65 to the nucleus and the phosphorylation and proteasomal degradation of the inhibitor of the NF-κB α protein. The present results revealed that 4-hydroxypanduratin A and isopanduratin A inhibit TNF-α-stimulated gene expression and the NF-κB-dependent signaling pathway in A549 cells.

Changes in microparticle profiles by vitamin D receptor activation in chronic kidney disease - a randomized trial.

BACKGROUND: Microparticles (MPs) are biomarkers and mediators of disease through their expression of surface receptors, reflecting activation or stress in their parent cells. Endothelial markers, ICAM-1 and VCAM-1, are implicated in atherosclerosis and associated with cardiovascular risk. Chronic kidney disease (CKD) patients have endothelial dysfunction and high levels of endothelial derived MPs. Vitamin D treatment has been reported to ameliorate endothelial function in CKD patients. We aimed to examine cell specific MP profiles and concentrations of MPs expressing the atherosclerotic markers ICAM-1 and VCAM-1 after treatment with paricalcitol in patients with CKD stage 3-4. METHODS: Sub-study of the previously reported SOLID trial where 36 patients were randomly assigned to placebo, 1 or 2 µg paricalcitol, for 12 weeks. MPs were measured by flow cytometry after labelling with antibodies against endothelial (CD62E), platelet (CD62P, CD41, CD154) leukocyte (CD45) and vascular (CD54, CD106) markers. RESULTS: Patients had a mean age of 65 years with a mean eGFR of 40 mL/min/1.73m2. Concentrations of ICAM-1 positive MPs were significantly reduced by treatment (repeated measures ANOVA p = 0.04). Repeated measures MANOVA of concentrations of endothelial, platelet and leukocyte MPs showed sustained levels in the 2 µg treatment group (p = 0.85) but a decline in the 1 µg (p = 0.04) and placebo groups (p = 0.005). CONCLUSIONS: Treatment with paricalcitol reduces concentrations of ICAM-1 positive MPs. This is accompanied by sustained concentrations of all cell specific MPs in the 2 µg group, and decreasing concentrations in the other groups, possibly due to a more healthy and reactive endothelium with paricalcitol treatment.

The ICAM-1 expression level determines the susceptibility of human endothelial cells to simulated microgravity.

Microgravity is a principal risk factor hampering human cardiovascular regulation during space flights. Endothelial dysfunction associated with the impaired integrity and uniformity of the monolayer represents a potential trigger for vascular damage. We characterized the expression profile of the multi-step cascade of adhesion molecules (ICAM-1, VCAM-1, E-selectin, VE-cadherin) in umbilical cord endothelial cells (ECs) after 24 h of exposure to simulated microgravity (SMG), pro-inflammatory cytokine TNF-α, and the combination of the two. Random Positioning Machine (RPM)-mediated SMG was used to mimic microgravity effects. SMG stimulated the expression of E-selectin, which is known to be involved in slowing leukocyte rolling. Primary ECs displayed heterogeneity with respect to the proportion of ICAM-1-positive cells. ECs were divided into two groups: pre-activated ECs displaying high proportion of ICAM-1+ -cells (ECs-1) (greater than 50%) and non-activated ECs with low proportion of ICAM-1+ -cells (ECs-2) (less than 25%). Only non-activated ECs-2 responded to SMG by elevating gene transcription and increasing ICAM-1 and VE-cadherin expression. This effect was enhanced after cumulative SMG-TNF-α exposure. ECs-1 displayed an unexpected decrease in number of E-selectin- and ICAM-1-positive ECs and pronounced up-regulation of VCAM1 upon activation of inflammation, which was partially abolished by SMG. Thus, non-activated ECs-2 are quite resistant to the impacts of microgravity and even exhibited an elevation of the VE-cadherin gene and protein expression, thus improving the integrity of the endothelial monolayer. Pre-activation of ECs with inflammatory stimuli may disturb the EC adhesion profile, attenuating its barrier function. These alterations may be among the mechanisms underlying cardiovascular dysregulation in real microgravity conditions.

Long non-coding RNA GAS5 aggravates hypoxia injury in PC-12 cells via down-regulating miR-124.

One important feature of cerebral ischemia is hypoxia injury in nerve cells. Growth arrest-specific transcript 5 (GAS5) is widely reported as a tumor suppressor gene; however, the investigations about its role in cerebrovascular disease are relatively rare. This study was aimed to explore the impact of GAS5 on hypoxia response in nervous cells. PC-12 cells were incubated under anoxic condition to induce hypoxia injury. Regulatory effects of GAS5 on miR-124 and miR-124 on ICAM-1 expression were assessed by qRT-PCR and/or Western blot. Targeting effect of miR-124 on ICAM-1 3'-untranslated regions (UTR) was evaluated through dual luciferase activity assay. The potential regulatory mechanism on hypoxia injury in PC-12 cells was assessed by detecting key elements of NF-κB and Notch signaling pathways using Western blot. GAS5 ectopic expression accentuated hypoxia injury in PC-12 cells. miR-124 expression was negatively regulated by GAS5 expression. Cells with overexpressions of GAS5 and miR-124 alleviated hypoxia injury as in compassion with cells only with GAS5 overexpression. ICAM-1 expression was negatively regulated by miR-124 expression. ICAM-1 was a functional target of miR-124. ICAM-1 overexpression aggravated hypoxia injury, but inversely, ICAM-1 silence diminished hypoxia damage. Besides, ICAM-1 expression was negatively related with activation of NF-κB and Notch pathways. GAS5-miR-124-ICAM-1 axis could regulate hypoxia injury in PC-12 cells. GAS5 might aggravate hypoxia injury via down-regulating miR-124, then up-regulating ICAM-1, and further enhancing activations of NF-κB and Notch pathways.

Markers of Inflammation and Incident Breast Cancer Risk in the Women's Health Study.

Chronic inflammation may be a risk factor for the development and progression of breast cancer, yet it is unknown which inflammatory biomarkers and pathways are especially relevant. The present study included 27,071 participants (mean age = 54.5 years) in the Women's Health Study who were free of cancer and cardiovascular disease at enrollment (1992-1995), with baseline measures of 4 inflammatory biomarkers: high-sensitivity C-reactive protein, fibrinogen, N-acetyl side-chains of acute phase proteins, and soluble intercellular adhesion molecule-1. We used Cox proportional hazards regression models to evaluate associations between baseline concentrations of biomarkers and incident breast cancer, and adjusted for baseline and time-varying factors such as age and body mass index. Self-reported invasive breast cancer was confirmed against medical records for 1,497 incident cases (90% postmenopausal). We observed different patterns of risk depending on the inflammatory biomarker. There was a significant direct association between fibrinogen and breast cancer risk (for quintile 5 vs. quintile 1, adjusted hazard ratio = 1.25, 95% confidence interval: 1.03, 1.51; P for trend = 0.01). In contrast, soluble intercellular adhesion molecule-1 was inversely associated with breast cancer (for quintile 5 vs. quintile 1, adjusted hazard ratio = 0.79, 95% confidence interval: 0.66, 0.94; P for trend = 0.02). N-acetyl side-chains of acute phase proteins and high-sensitivity C-reactive protein were not associated with breast cancer. The complex association of chronic inflammation and breast cancer may be considered when formulating anti-inflammatory cancer prevention or intervention strategies.

ICAM-1-expressing neutrophils exhibit enhanced effector functions in murine models of endotoxemia.

Intracellular adhesion molecule-1 (ICAM-1) is a transmembrane glycoprotein expressed on the cell surface of numerous cell types such as endothelial and epithelial cells, vascular smooth muscle cells, and certain leukocyte subsets. With respect to the latter, ICAM-1 has been detected on neutrophils in several clinical and experimental settings, but little is known about the regulation of expression or function of neutrophil ICAM-1. In this study, we report on the de novo induction of ICAM-1 on the cell surface of murine neutrophils by lipopolysaccharide (LPS), tumor necrosis factor, and zymosan particles in vitro. The induction of neutrophil ICAM-1 was associated with enhanced phagocytosis of zymosan particles and reactive oxygen species (ROS) generation. Conversely, neutrophils from ICAM-1-deficient mice were defective in these effector functions. Mechanistically, ICAM-1-mediated intracellular signaling appeared to support neutrophil ROS generation and phagocytosis. In vivo, LPS-induced inflammation in the mouse cremaster muscle and peritoneal cavity led to ICAM-1 expression on intravascular and locally transmigrated neutrophils. The use of chimeric mice deficient in ICAM-1 on myeloid cells demonstrated that neutrophil ICAM-1 was not required for local neutrophil transmigration, but supported optimal intravascular and extravascular phagocytosis of zymosan particles. Collectively, the present results shed light on regulation of expression and function of ICAM-1 on neutrophils and identify it as an additional regulator of neutrophil effector responses in host defense.

The peptide lycosin-I attenuates TNF-α-induced inflammation in human umbilical vein endothelial cells via IκB/NF-κB signaling pathway.

OBJECTIVE: The peptide lycosin-I has anti-bacterial and anti-cancer capacities. However, the anti-inflammatory activity of lycosin-I remains unknown. We investigated whether lycosin-I could attenuate inflammation. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with lycosin-I before exposure to tumor necrosis factor-α (TNF-α). The expression of intercellular cell adhesion molecule-1 (ICAM-1), nuclear transcription factor-kappa B (NF-κB) p65 and inhibitory subunit of NF-κB alpha (IκBα) was evaluated by western blot. The expression of interleukin-6 (IL-6) and interleukin-8 (IL-8) was detected by quantitative RT-PCR or ELISA. Immunofluorescence analysis was used to determine the impact of lycosin-I on NF-κB pathway. C57BL/6 mice were pretreated with lycosin-I before exposure with lipopolysaccharide (LPS). RESULTS: Lycosin-I significantly reduced the TNF-α-enhanced expression of IL-6, IL-8 and ICAM-1. Lycosin-I also inhibited the human monocyte cells adhesion to HUVECs. We further demonstrated that lycosin-I could effectively suppress the reaction of endothelial cells to TNF-α by inhibiting IκBα degradation. Subsequently, the phosphorylation and translocation of NF-κB p65 could also be attenuated. Furthermore, lycosin-I exhibited a significant protection of C57BL/6 mice against LPS-induced death. CONCLUSIONS: Our results suggested that the anti-inflammatory activity of lycosin-I was associated with NF-κB activation and lycosin-I had potential to be a novel therapeutic candidate for inflammatory diseases.