Effects Of RAGE Research Articles

Receptor for advanced glycation end product blockade enhances the chemotherapeutic effect of cisplatin in tongue squamous cell carcinoma by reducing autophagy and modulating the Wnt pathway.

Tongue squamous cell carcinoma (TSCC) is one of the most severe types of cancer with poor outcomes. Cisplatin is used widely to treat cancer cells, but many patients develop acquired drug resistance. The receptor for advanced glycation end products (RAGE) is expressed widely in TSCC and associated with drug-induced chemotherapy resistance. However, the effect of RAGE and cisplatin on Tca-8113 cells remains unknown. We assayed the combined use of RAGE blockade and cisplatin effect on Tca-8113 cells' viability by MTT and apoptosis rate of Tca-8113 cells on RAGE blockade+cisplatin treatment; cisplatin alone; or RAGE blockade alone by flow cytometry. We observed the expressions of autophagy-related proteins beclin1, LC3II, p62; Wnt signaling-related proteins β-catenin, GSK3β, WNT5A, ROR-2; and apoptosis-related protein cleaved caspase-3, bcl-2-associated X proteins using western blot. We determined WNT5A and beclin1 expression on Tca-8113 cells by immunofluorescence. We further observed autophagy vacuoles by monodansylcadaverine staining. We found that RAGE blockade and cisplatin significantly decreased cell viability and increased the cell apoptosis rate compared with cisplatin alone. Furthermore, RAGE blockade suppressed the canonical Wnt pathway proteins β-catenin and GSK-3β, but upregulated noncanonical WNT5A and receptor ROR-2. We show that RAGE blockade suppressed the levels of autophagy-related protein LC3II/I, beclin1, accelerated degradation of autophagy for the increasing p62 expression, and increased cell apoptosis for the increasing expressions of cleaved caspase-3 and bcl-2-associated X proteins. We observed the location of WNT5A and beclin1 expressions on cells by immunofluorescence and their trends were consistent with western blotting. Taken together, our findings suggested that RAGE blockade+cisplatin improved chemotherapeutic effects by reducing autophagy and regulating Wnt/β-catenin to suppress the progression of TSCC.

Abstract 114: Macrophages Mediate the Ability of the Receptor for Advanced Glycation End Products to Prevent Formation of Abdominal Aortic Aneurysm in a Murine Model

INTRODUCTION: The pathophysiology of AAAs is multifactorial, involving chronic inflammation, increased MMP expression/activity, and medial elastic fiber destruction. RAGE transduces the biological impact of ligand families including AGEs, S100, and HMGB1 to upregulate inflammatory and tissue injury-provoking genes including MMPs. We previously identified increased RAGE expression in human AAAs and have shown that the absence of RAGE, whether by genetic deletion or pharmacologic blockade with sRAGE, prevents AAA formation in a mouse model. We sought to characterize the cellular mediators of this effect. METHODS: C57BL/6 wild-type (WT) and RAGE null (KO) mice underwent transient elastase perfusion to induce AAAs. Mice were sacrificed at day 14 and flow cytometry performed to characterize differences in activation (CD69+) of lymphocytes (CD4/8), neutrophils (GR1+/CD11b+), macrophages (F480), NK cells (NK1.1) (n=24/group). Immunohistochemistry was performed for Mac-3 and Arg 1 (M2 marker) or Arg 2 (M1 marker). Primary BMDMs were isolated and skewed towards M1 (LPS/IFN ¡) or M2 (LPS, IL-4, IL-13) with the addition of S100b or HMGB1 to determine the ligands' effect upon macrophage skewing by ELISA. RESULTS: Flow cytometry revealed increased aortic expression of activated CD8+ cells (p=0.002), macrophages (p-0.002), and NK cells (p=0.03). No differences were noted in cellular activation from spleens from the same animals. Immunohistochemistry revealed increased macrophage expression in WT vs KO aortae, highest at day 5 (p=0.04). Arg 1 and 2 expression on macrophages was elevated in WT vs KO animals (p=0.03). Skewing BMDMs from WT and KO towards M1 led to elevated TNFα with addition of either S100b (p=0.02) or HMGB1 (p=0.03). Skewing BMDMs towards M2 led to elevated IL-10 in KO vs WT cells with the addition of S100b (p=0.01). HMGB1 has no effect upon skewing towards M2. CONCLUSIONS: The effect of RAGE in the development of murine AAA appears to be mediated by macrophages. Differential macrophage skewing towards an M1 by both S100b and HMGB1 likely plays a role in this effect. Skewing towards M2 is mediated by S100b and not HMGB1. Further studies will seek to identify at which stage in AAA formation activation of the RAGE-ligand axis becomes functionally important.

The receptor for advanced glycation end products (RAGE) affects T cell differentiation in OVA induced asthma.

The receptor for glycation end products (RAGE) has been previously implicated in shaping the adaptive immune response. RAGE is expressed in T cells after activation and constitutively in T cells from patients with diabetes. The effects of RAGE on adaptive immune responses are not clear: Previous reports show that RAGE blockade affects Th1 responses. To clarify the role of RAGE in adaptive immune responses and the mechanisms of its effects, we examined whether RAGE plays a role in T cell activation in a Th2 response involving ovalbumin (OVA)-induced asthma in mice. WT and RAGE deficient wild-type and OT-II mice, expressing a T cell receptor specific for OVA, were immunized intranasally with OVA. Lung cellular infiltration and T cell responses were analyzed by immunostaining, FACS, and multiplex bead analyses for cytokines. RAGE deficient mice showed reduced cellular infiltration in the bronchial alveolar lavage fluid and impaired T cell activation in the mediastinal lymph nodes when compared with WT mice. In addition, RAGE deficiency resulted in reduced OT-II T cell infiltration of the lung and impaired IFNγ and IL-5 production when compared with WT mice and reduced infiltration when transferred into WT hosts. When cultured under conditions favoring the differentiation of T cells subsets, RAGE deficient T cells showed reduced production of IFNγ but increased production of IL-17. Our data show a stimulatory role for RAGE in T activation in OVA-induced asthma. This role is largely mediated by the effects of RAGE on T cell proliferation and differentiation. These findings suggest that RAGE may play a regulatory role in T cell responses following immune activation.

Associations of Receptor for Advanced Glycation End Products -374 T/A and Gly82 Ser and Peroxisome Proliferator-Activated Receptor Gamma Pro12Ala Polymorphisms in Turkish Coronary Artery Disease Patients

The aim of the present study was to investigate the individual and combined effects of receptor for advanced glycation end products (RAGE) -374T/A, RAGE Gly82Ser, and peroxisome proliferator-activated receptor gamma (PPAR-γ) Pro12Ala polymorphisms on the development of coronary artery disease (CAD). This study was carried out in 87 patients with CAD and 52 CAD-free healthy controls. Polymerase chain reaction, restriction fragment length polymorphism, and agarose gel electrophoresis techniques were used to determine RAGE -374T/A, RAGE Gly82 Ser, and PPAR-γ Pro12 Ala. Individual allele and genotype frequencies of RAGE -374T/A, RAGE Gly82Ser, and PPAR-γ Pro12Ala polymorphisms were not significantly different between study groups. However, compared with the control group, wild-type T allele frequency was found to be higher in patients with diabetes (p=0.009). To investigate the combined effects of RAGE and PPAR polymorphisms, haplotype analysis was elevated and there was no statistical difference between the haplotypes of RAGE Gly82Ser with RAGE-374T/A or PPAR Pro12Ala. However, the frequency of RAGE-374T/PPAR12Ala haplotype was found to be higher in both the patient group (p=0.024) and in patients without diabetes (p=0.037). The results of the present study demonstrated that possessing the A allele of RAGE -374T/A polymorphism by diabetic CAD patients and possessing the-374T/Ala12 haplotype of RAGE -374T/A and PPAR-γ Pro12 Ala polymorphisms by the patients group were the most important risk factors for CAD.

Abstract 1418: Receptor For Advanced-glycation End Products Inhibits Myocardin Function And Induces Msx2-dependent Osteoblastic Differentiation Of Vascular Smooth Muscle Cells

As an activator of diverse signaling pathways in the vascular cells, receptor for advanced-glycation end products (RAGE) has been related to atherosclerosis initiation and progression in the patients with diabetes and chronic renal failure (CRF). However, little is known about the efects of RAGE activation on the differentiation program of vascular smooth muscle cells (VSMC). We first examined effects of RAGE on expression of myosin heavy chain (MHC), a definitive VSMC marker. RT-PCR analyses showed that expression of MHC was diminished in VSMC transduced with adenovirus expressing RAGE. A RAGE ligand HMGB1, but not another ligand AGE2, enhanced RAGE-dependent MHC repression. Activation of HMGB1-RAGE pathway induced the endogenous RAGE expression, suggesting positive feedback loop in atherosclerotic lesion. In mesenchymal 10T1/2 cells, HMGB1-RAGE inhibited an induction of MHC gene expression by myocardin, a potent positive regulator of VSMC differentiation. We next examined the effects of RAGE on osteogenic conversion of VSMC by monitoring the expression and activity of alkaline phosphatase (ALP). RT-PCR analysis showed that expression of ALP was up-regulated in VSMC when RAGE was overexpressed by adenovirus. The degree of the ALP induction was dependent on the concentration of fetal bovine serum, suggesting that fetal bovine serum contains RAGE ligands. The induction of ALP was accompanied by ALP activity and an inducible expression of osteogenic transcription factors, Msx2 and Runx2 as well as an increase in osteopontin and bone morphogenic protein 2 (BMP2) expression. We further found that addition of BMP2 and RAGE synergistically enhanced expression of ALP mRNA and ALP activity. Immunohistochemistry revealed that RAGE antigen is present in calcified atherosclerotic plaque in a distribution overlapping with osteoblastic markers and calcium deposition detected by Kossa staining in human carotid artery. These findings suggest that RAGE induction in VSMC contributes to the development of calcifying atherosclerotic plaque characterizing the diabetes- and CRF-associated vascular lesion by repressing myocardin-induced VSMC differentiation and inducing Msx2-dependent osteogenic differentiation.

Episodic dyscontrol: A look back at anger

Abstract following the most trivial and impersonal causes there is the effect of rage with its motor accompaniments. They may be the most grotesque gesticulations, excessive movements of the face and a sharp explosiveness of speech; there will be cursing and outbreaks of violence which are often directed toward things; there may or may not be amnesia for these events afterwards. (Kaplan, 1899:295)

Explosive Rage Following Head Injury

In 1899 Kaplan described the “explosive diathesis” as follows: “Following the most trivial and impersonal causes, there is the effect of rage with its motor accompaniments. There may be the most grotesque gesticulation, excessive movements of the face, and a quick, sharp explosiveness of speech; there may be cursing and outbreaks of violence, which are often directed towards things; there may or may not be an amnesia for these afterwards. These outbursts may terminate in an epileptic fit. There is an excess in the reaction, with inadequate adaptation to the situation so remote from a well-considered purposeful act that it approaches a pure psychic reflex act in the shape of an almost or entirely unmodified explosion not unlike a convulsion. The explosive diathesis is not characteristic of head injuries, but is also found in hereditary degeneration, in alcoholic degeneration, etc.”