1
|
Neelofar KM, Ahmad J, Arif Z, Alam K. Elucidating the impact of glucosylation on human serum albumin: A multi-technique approach. Int J Biol Macromol 2016; 92:881-891. [PMID: 27492562 DOI: 10.1016/j.ijbiomac.2016.07.104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/28/2016] [Accepted: 07/30/2016] [Indexed: 11/16/2022]
Abstract
Early glycation products as well as advance glycation end products are involved in pathogenesis of diabetes. Most of studies carried out on AGEs and their possible role in assessing diabetes complications, whereas only a few were focused to highlight the role of Amadori products. In this study, an attempt has been made to investigate a structural and immunological characterizations of Amadori-albumin upon early glucosylation because albumin undergoes fast glycation under hyperglycaemic condition. Amadori-albumin formation was determined by NBT assay and Amadori adducts in glycated samples were confirmed by LC-MS. Structural alterations in Amadori-albumin were characterized by loss in fluorescence intensity, loss in secondary and tertiary structures, exposure of hydrophobic patches, shifting in Amide bands and increment in hydrodynamic radius. Further, presence to autoantibodies against Amadori-albumin in diabetes patients were confirmed by direct binding ELISA and inhibition ELISA. Immunological studies results showed that autoantibodies present in diabetic patients with and without chronic kidney disease (CKD) showed significant binding with Amadori-albumin in comparison to the native protein. Anti Amadori-albumin antibodies predominantly present in CKD patients compare to without CKD patients. Band shift assay results showed true interaction between Amadori-albumin and autoantibodies present in CKD patients. Glucosylation results showed structural alterations in Amadori-albumin and hence generation of neo-epitopes in HSA molecule. Such modifications rendering the protein highly immunogenic that may be recognized as foreign molecule by immune cells and induced autoantibodies in diabetic patients. These finding signify the role of Amadori-albumin in kidney dysfunction in diabetes and raised level of autoantibodies may be used as biomarker for progression of CKD.
Collapse
Affiliation(s)
- K M Neelofar
- Rajiv Gandhi Centre for Diabetes and Endocrinology, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh 202002, India
| | - Jamal Ahmad
- Rajiv Gandhi Centre for Diabetes and Endocrinology, Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh 202002, India.
| | - Zarina Arif
- Department of Biochemistry Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh 202002, India
| | - Khursheed Alam
- Department of Biochemistry Faculty of Medicine, J.N. Medical College, Aligarh Muslim University, Aligarh 202002, India
| |
Collapse
|
2
|
Bhat S, Mary S, Banarjee R, Giri AP, Kulkarni MJ. Immune response to chemically modified proteome. Proteomics Clin Appl 2014; 8:19-34. [PMID: 24375944 DOI: 10.1002/prca.201300068] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 11/10/2022]
Abstract
Both enzymatic and nonenzymatic PTMs of proteins involve chemical modifications. Some of these modifications are prerequisite for the normal functioning of cell, while other chemical modifications render the proteins as "neo-self" antigens, which are recognized as "non-self" leading to aberrant cellular and humoral immune responses. However, these modifications could be a secondary effect of autoimmune diseases, as in the case of type I diabetes, hyperglycemia leads to protein glycation. The enigma of chemical modifications and immune response is akin to the "chick-and-egg" paradox. Nevertheless, chemical modifications regulate immune response. In some of the well-known autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis, chemically modified proteins act as autoantigens forming immune complexes. In some instances, chemical modifications are also involved in regulating immune response during pathogen infection. Further, the usefulness of proteomic analysis of immune complexes is briefly discussed.
Collapse
Affiliation(s)
- Shweta Bhat
- Proteomics Facility, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
| | | | | | | | | |
Collapse
|
3
|
Cohen MP. Clinical, pathophysiological and structure/function consequences of modification of albumin by Amadori-glucose adducts. Biochim Biophys Acta Gen Subj 2013; 1830:5480-5. [PMID: 23624335 DOI: 10.1016/j.bbagen.2013.04.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 04/16/2013] [Accepted: 04/17/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND The nonenzymatic condensation of glucose with albumin results in the formation of albumin modified by Amadori glucose adducts, the principal form in which glycated albumin exists in vivo. SCOPE OF REVIEW This review focuses on (a) the utility of measurement of Amadori-modified glycated albumin (AGA) as a biomarker in diabetes, where elevated levels attend the hyperglycemic state; (b) the role of AGA as a causal factor in the pathogenesis of complications of diabetes; (c) effects on transport properties; and (d) structural and functional consequences of the modification of albumin by Amadori glucose adducts. It does not discuss counterparts with respect to Advanced Glycation Endproducts (AGE), which may be found in other publications. MAJOR CONCLUSIONS Nonenzymatic glycation of albumin, which is increased in diabetes, has clinical relevance and pathophysiologic importance, with ramifications for the management of this disease, the development of its complications, and the transport of endogenous and exogenous ligands. GENERAL SIGNIFICANCE Appreciation of the manifold consequences of AGA has afforded new avenues for assessing clinical management of diabetes, awareness of the impact of nonenzymatic glycation on albumin biology, insights into the pathogenesis of vascular complications of diabetes, and avenues of investigation of and intervention strategies for these complications. This article is part of a Special Issue on albumin. This article is part of a Special Issue entitled Serum Albumin.
Collapse
Affiliation(s)
- Margo P Cohen
- Glycadia, Inc., 1880 JFK Boulevard, Suite 200, Philadelphia, PA 19103, United States.
| |
Collapse
|
4
|
Arif B, Ashraf JM, Moinuddin, Ahmad J, Arif Z, Alam K. Structural and immunological characterization of Amadori-rich human serum albumin: role in diabetes mellitus. Arch Biochem Biophys 2012; 522:17-25. [PMID: 22516656 DOI: 10.1016/j.abb.2012.04.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 03/30/2012] [Accepted: 04/03/2012] [Indexed: 12/23/2022]
Abstract
Proteins modifications in diabetes may lead to early glycation products (EGPs) as well as advanced glycation end products (AGEs). Whereas no extensive studies have been carried out to assess the role of EGPs in secondary complications of diabetes, numerous investigators have demonstrated the role of AGEs. Early glycation involves attachment of glucose on ε-NH2 of lysine residues of proteins leading to generation of the Amadori product (an early glycation species). This study reports the structural and immunological characterization of EGPs of HSA because we believe that during persistent hyperglycemia the HSA, one of the major blood proteins, can undergo fast glycation. Glucose mediated generation of EGPs of HSA was quantitated as Amadori products by NBT assay and authenticated by boronate affinity chromatography and LC/MS. Compared to native HSA changes in glycated-HSA were characterized by hyperchromicity, loss in fluorescence intensity and a new peak in the FTIR profile. Immunogenicity of native- and glycated-HSA was evaluated by inducing antibodies in rabbits. Results suggest generation of neo-epitopes on glycated-HSA rendering it highly immunogenic compared to native HSA. Quantization of EGPs of HSA by authentic antibodies against HSA-EGPs can be used as marker for early detection of the initiation/progression of secondary complications of diabetes.
Collapse
Affiliation(s)
- Binish Arif
- Department of Biochemistry, Faculty of Medicine, A.M.U., Aligarh 202002, UP, India
| | | | | | | | | | | |
Collapse
|
5
|
Liu W, Xu GZ, Jiang CH, Tian J. Macrophage colony-stimulating factor and its receptor signaling augment glycated albumin-induced retinal microglial inflammation in vitro. BMC Cell Biol 2011; 12:5. [PMID: 21266043 PMCID: PMC3038972 DOI: 10.1186/1471-2121-12-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Accepted: 01/25/2011] [Indexed: 01/30/2023] Open
Abstract
Background Microglial activation and the proinflammatory response are controlled by a complex regulatory network. Among the various candidates, macrophage colony-stimulating factor (M-CSF) is considered an important cytokine. The up-regulation of M-CSF and its receptor CSF-1R has been reported in brain disease, as well as in diabetic complications; however, the mechanism is unclear. An elevated level of glycated albumin (GA) is a characteristic of diabetes; thus, it may be involved in monocyte/macrophage-associated diabetic complications. Results The basal level of expression of M-CSF/CSF-1R was examined in retinal microglial cells in vitro. Immunofluorescence, real-time PCR, immunoprecipitation, and Western blot analyses revealed the up-regulation of CSF-1R in GA-treated microglial cells. We also detected increased expression and release of M-CSF, suggesting that the cytokine is produced by activated microglia via autocrine signaling. Using an enzyme-linked immunosorbent assay, we found that GA affects microglial activation by stimulating the release of tumor necrosis factor-α and interleukin-1β. Furthermore, the neutralization of M-CSF or CSF-1R with antibodies suppressed the proinflammatory response. Conversely, this proinflammatory response was augmented by the administration of M-CSF. Conclusions We conclude that GA induces microglial activation via the release of proinflammatory cytokines, which may contribute to the inflammatory pathogenesis of diabetic retinopathy. The increased microglial expression of M-CSF/CSF-1R not only is a response to microglial activation in diabetic retinopathy but also augments the microglial inflammation responsible for the diabetic microenvironment.
Collapse
Affiliation(s)
- Wei Liu
- Department of Opthalmology, EENT Hospital, Eye Institute, Fudan University, Shanghai, 200031, China
| | | | | | | |
Collapse
|
6
|
Rodiño-Janeiro BK, González-Peteiro M, Ucieda-Somoza R, González-Juanatey JR, Alvarez E. Glycated albumin, a precursor of advanced glycation end-products, up-regulates NADPH oxidase and enhances oxidative stress in human endothelial cells: molecular correlate of diabetic vasculopathy. Diabetes Metab Res Rev 2010; 26:550-8. [PMID: 20818804 DOI: 10.1002/dmrr.1117] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND Hyperglycaemia induces non-enzymatic glycation reactions in proteins which generate Amadori products and advanced glycation end-products; the latter are thought to participate in the vascular complications of diabetic patients. However, the exact mechanisms concerning the effects of glycated proteins on vascular tissue remain to be determined. Therefore, the effects of glycated human serum albumin on human umbilical vein endothelial cells were studied. METHODS Reactive oxygen species production was measured by the cytochrome C reduction method and by 5(6)-carboxy-2',7'-dichlorofluorescein diacetate (c-DCF-DA) fluorescence after treating human umbilical vein endothelial cells with glycated human serum albumin (6-200 µg/mL). The expression of Nox4 and p22phox mRNAs were analysed by reverse transcription-quantitative polymerase chain reactions and the levels of their proteins were measured by immunofluorescence. RESULTS Low concentrations of glycated human serum albumin enhanced reactive oxygen species production in human umbilical vein endothelial cells after 4 h of treatment at both extracellular and intracellular sites. This enhanced production was sustained, although to a lesser extent, after 6 and 12 h of treatment. The gene expression study revealed that Nox4 and p22phox mRNA levels were elevated after 4 h of treatment with glycated human serum albumin. This mRNA elevation and enhanced reactive oxygen species production correlated with an increased expression of the Nox4 protein. CONCLUSIONS The results revealed that a circulating and abundant modified glycated human serum albumin protein in diabetic patients induced a sustained reactive oxygen species production in human endothelial cells. This effect may have been due to an up-regulation of Nox4, the main subunit of NADPH oxidase in the endothelium.
Collapse
Affiliation(s)
- Bruno K Rodiño-Janeiro
- Departamento de Medicina, Universidad de Santiago de Compostela and Servicio de Cardiología, Complejo Hospitalario Universitario de Santiago de Compostela, Coruña, Spain
| | | | | | | | | |
Collapse
|
7
|
Li Y, Wang S. Glycated albumin activates NADPH oxidase in rat mesangial cells through up-regulation of p47phox. Biochem Biophys Res Commun 2010; 397:5-11. [PMID: 20399741 DOI: 10.1016/j.bbrc.2010.04.084] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 04/12/2010] [Indexed: 01/26/2023]
Abstract
Glycated albumin, an early-glycation Amadori-modified protein, stimulates transforming growth factor-beta (TGF-beta) expression and increases the production of the extracellular matrix proteins in mesangial cells, contributing to the pathogenesis of diabetic nephropathy. Glycated albumin has been shown to increase NADPH oxidase-dependent superoxide formation in mesangial cells. However, the mechanisms are not well understood. Therefore, in the present studies, we determined the mechanisms by which glycated albumin activates NADPH oxidase in primary rat mesangial cells and its contribution to glycated albumin-induced TGF-beta expression and extracellular matrix protein production. Our data showed that glycated albumin treatment stimulated NADPH oxidase activity and increased the formation of superoxide formation in rat mesangial cells. Moreover, glycated albumin treatment stimulated the expression and phosphorylation of p47phox, one of the cytosolic regulatory subunits of the NADPH oxidase. However, the levels of other NADPH oxidase subunits including Nox1, Nox2, Nox4, p22phox, and p67phox were not altered by glycated albumin. Moreover, siRNA-mediated knockdown of p47phox inhibited glycated albumin-induced NADPH oxidase activity and superoxide formation. Glycated albumin-induced TGF-beta expression and extracellular matrix production (fibronectin) was also inhibited by p47phox knock down. Taken together, these data suggest that up-regulation of p47phox is involved in glycated albumin-mediated activation of NADPH oxidase, leading to glycated albumin-induced expression of TGF-beta and extracellular matrix proteins in mesangial cells and contributing to the development of diabetic nephropathy.
Collapse
Affiliation(s)
- Yanzhang Li
- Graduate Center for Nutritional Sciences, University of Kentucky, 900 S. Limestone Street, Lexington, KY 40536, USA
| | | |
Collapse
|
8
|
Li Y, Wang S. Glycated albumin upregulates upstream stimulatory factor 2 gene transcription in mesangial cells. Am J Physiol Renal Physiol 2010; 299:F121-7. [PMID: 20410211 DOI: 10.1152/ajprenal.00074.2010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Diabetic nephropathy (DN) is the most common cause of end-stage renal failure. We previously demonstrated that a transcription factor called upstream stimulatory factor 2 (USF2) was upregulated in the kidneys from diabetic animals in vivo as well as in mesangial cells (MCs) exposed to high-glucose media in vitro. USF2 mediates glucose-induced thrombospondin 1 expression and transforming growth factor-beta activity in MCs and plays a role in DN. Glycated proteins have been shown to accumulate in the kidneys of diabetic patients and contribute to DN. However, whether glycated proteins regulate USF2 expression in MCs and play a role in DN is unknown. In the present studies, we determined the effect of glycated albumin on UFS2 gene expression in primary rat MCs. We found that glycated albumin upregulated USF2 expression (mRNA and protein) in a dose- and time-dependent manner. We also demonstrated that glycated albumin stimulated USF2 gene expression at the transcriptional level. By using the luciferase-promoter deletion assay, site-directed mutagenesis, and transactivation assay, we identified a glycated albumin-responsive region in the USF2 gene promoter (-837 to -430, relative to the transcription start site) and demonstrated that glycated albumin-induced USF2 expression was mediated through NF-kappaB-dependent transactivation of the USF2 promoter. Furthermore, glycated albumin increased nuclear NF-kappaB subunit-p65 protein levels. siRNA-mediated p65 knockdown prevented glycated albumin-induced USF2 gene expression (promoter activity, mRNA, and protein levels). Taken together, these data suggest that glycated albumin upregulated USF2 gene transcription in MCs through NF-kappaB-dependent transactivation of the USF2 promoter.
Collapse
Affiliation(s)
- Yanzhang Li
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, Kentucky 40536, USA
| | | |
Collapse
|
9
|
Higai K, Satake M, Nishioka H, Azuma Y, Matsumoto K. Glycated human serum albumin enhances macrophage inflammatory protein-1β mRNA expression through protein kinase C-δ and NADPH oxidase in macrophage-like differentiated U937 cells. Biochim Biophys Acta Gen Subj 2008; 1780:307-14. [DOI: 10.1016/j.bbagen.2007.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 11/15/2007] [Accepted: 11/16/2007] [Indexed: 10/22/2022]
|
10
|
Higai K, Sano R, Satake M, Azuma Y, Matsumoto K. Glycated human serum albumin induces interleukin 8 mRNA expression through reactive oxygen species and NADPH oxidase-dependent pathway in monocyte-derived U937 cells. Biol Pharm Bull 2007; 30:1833-7. [PMID: 17917246 DOI: 10.1248/bpb.30.1833] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glycated human serum albumin (Glc-HSA) has previously been reported (Higai K., et al., 2006) to induce E-selectin expression on human umbilical vein endothelial cells through activation of NADPH oxidase; however, Glc-HSA signaling in monocytes remains obscure. To clarify the influence on human monocyte-derived U937 cells, U937 cells were stimulated with Glc-HSA and glycoaldehyde-dimer-modified HSA (GA-HSA) for 2 h in the absence and presence of the protein kinase C (PKC) inhibitor calphostin and the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) and NADPH oxidase inhibitor apocynin; interleukin-8 (IL-8) mRNA expression was determined by RT-PCR. As a result, IL-8 mRNA expression in U-937 cells was time- and dose-dependently enhanced by stimulation with Glc-HSA and GA-HSA. Furthermore, promoter activity of the IL-8 reporter gene was enhanced approximately 2-fold by stimulation with Glc-HSA and GA-HSA. Nuclear factor kappaB (NFkappaB) and activator protein-1 (AP-1) reporter genes were also enhanced although CCAAT/enhancer binding protein (C/EBP) was not affected. IL-8 mRNA expression was suppressed by NAC and apocynin but not calphostin in cells stimulated with Glc-HSA; however, its expression in cells stimulated with GA-HSA was suppressed by calphostin but not NAC. These results indicated that IL-8 mRNA expression was upregulated by NFkappaB and AP-1 in U937 cells stimulated with Glc-HSA and GA-HSA, but the signaling pathways were different.
Collapse
Affiliation(s)
- Koji Higai
- Department of Clinical Chemistry, School of Pharmaceutical Sciences, Toho University, Funahashi, Chiba, Japan.
| | | | | | | | | |
Collapse
|
11
|
Brandt R, Krantz S. Glycated albumin (Amadori product) induces activation of MAP kinases in monocyte-like MonoMac 6 cells. Biochim Biophys Acta Gen Subj 2006; 1760:1749-53. [PMID: 17049167 DOI: 10.1016/j.bbagen.2006.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 09/04/2006] [Accepted: 09/07/2006] [Indexed: 11/30/2022]
Abstract
Increased levels of glycated, Amadori-modified albumin are a risk factor for diabetic vascular disorders. Glycated albumin binds to specific receptors and induces cellular signaling pathways, the complexity of which is largely unknown. Binding of glycated albumin to MonoMac 6 cells leads to an activation of MAPK p44/42 (ERK1/2) and p38 with subsequent translocation of NF-kappaB into the nucleus. The activation of MAPK is in part mediated by protein kinase C activation, but a PKC-independent pathway via MEK-1 is also involved. Protein tyrosine kinases do not play a role in the activation of NF-kappaB. The results may have pathophysiological significance, because the MonoMac 6 cell line is not greatly different from blood monocytes.
Collapse
Affiliation(s)
- Rowena Brandt
- Institute of Medical Biochemistry and Molecular Biology, Ernst Moritz Arndt University, Klinikum Sauerbruchstrasse, D-17487 Greifswald, Germany.
| | | |
Collapse
|
12
|
Cohen MP, Ziyadeh FN, Chen S. Amadori-modified glycated serum proteins and accelerated atherosclerosis in diabetes: pathogenic and therapeutic implications. ACTA ACUST UNITED AC 2006; 147:211-9. [PMID: 16697768 PMCID: PMC1800931 DOI: 10.1016/j.lab.2005.12.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2005] [Revised: 12/21/2005] [Accepted: 12/21/2005] [Indexed: 10/24/2022]
Affiliation(s)
- Margo P Cohen
- University City Science Center, Philadelphia, Pennsylvania, USA.
| | | | | |
Collapse
|
13
|
Higai K, Shimamura A, Matsumoto K. Amadori-modified glycated albumin predominantly induces E-selectin expression on human umbilical vein endothelial cells through NADPH oxidase activation. Clin Chim Acta 2006; 367:137-43. [PMID: 16455066 DOI: 10.1016/j.cca.2005.12.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 12/03/2005] [Accepted: 12/03/2005] [Indexed: 11/28/2022]
Abstract
BACKGROUND Protein glycation is closely linked to endothelial-cell dysfunction and vascular complications in diabetes. Glycated albumin is reported to induce cellular signaling similar to advanced glycation endoproducts (AGEs), however, cellular signaling remains obscure. METHOD We stimulated human umbilical vein endothelial cells (HUVECs) by glycated human serum albumin (Glc-HSA), determined E-selectin expression by real-time PCR and immunometric methods, and estimated cellular signaling by using various signaling molecule inhibitors and confocal microscopy. RESULTS Glc-HSA-induced E-selectin expression was 10 or 20 times more than that induced with 3 kinds of AGEs-HSAs, which was not suppressed by anti-receptor for AGEs (RAGE) antibody. Glc-HSA-induced E-selectin expression was completely suppressed by the NADPH oxidase inhibitor diphenylene iodonium chloride and the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine. Confocal microscopic analysis also revealed intracellular accumulation of ROS. Glc-HSA-induced E-selectin expression was suppressed by the phosphatidylinositol 3 kinase (PI3K) inhibitors wortmannin and LY294002, the protein kinase B (PKB) inhibitor ML-9, the IkappaB kinase (IKK) inhibitor BAY117082, and the Jun N-terminal kinase (JNK) inhibitor SP600125, On the other hand, the protein kinase C inhibitors calphostin C and H-7 did not suppress Glc-HSA-induced E-selectin expression. CONCLUSION Glc-HSA induces activation of NADPH oxidase, PKB-IKK and JNK, then E-selectin gene transcription is upregulated by nuclear-translocated NF-kappaB and AP-1.
Collapse
Affiliation(s)
- Koji Higai
- Department of Clinical Chemistry, School of Pharmaceutical Sciences, Toho University Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan.
| | | | | |
Collapse
|