1
|
Kennon AM, Stewart JA. Paracrine Signals in Calcified Conditioned Media Elicited Differential Responses in Primary Aortic Vascular Smooth Muscle Cells and in Adventitial Fibroblasts. Int J Mol Sci 2023; 24:ijms24043599. [PMID: 36835011 PMCID: PMC9961433 DOI: 10.3390/ijms24043599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
Our goal was to determine if paracrine signals from different aortic layers can impact other cell types in the diabetic microenvironment, specifically medial vascular smooth muscle cells (VSMCs) and adventitial fibroblasts (AFBs). The diabetic hyperglycemic aorta undergoes mineral dysregulation, causing cells to be more responsive to chemical messengers eliciting vascular calcification. Advanced glycation end-products (AGEs)/AGE receptors (RAGEs) signaling has been implicated in diabetes-mediated vascular calcification. To elucidate responses shared between cell types, pre-conditioned calcified media from diabetic and non-diabetic VSMCs and AFBs were collected to treat cultured murine diabetic, non-diabetic, diabetic RAGE knockout (RKO), and non-diabetic RKO VSMCs and AFBs. Calcium assays, western blots, and semi-quantitative cytokine/chemokine profile kits were used to determine signaling responses. VSMCs responded to non-diabetic more than diabetic AFB calcified pre-conditioned media. AFB calcification was not significantly altered when VSMC pre-conditioned media was used. No significant changes in VSMCs signaling markers due to treatments were reported; however, genotypic differences existed. Losses in AFB α-smooth muscle actin were observed with diabetic pre-conditioned VSMC media treatment. Superoxide dismutase-2 (SOD-2) increased with non-diabetic calcified + AGE pre-conditioned VSMC media, while same treatment decreased diabetic AFBs levels. Overall, non-diabetic and diabetic pre-conditioned media elicited different responses from VSMCs and AFBs.
Collapse
Affiliation(s)
- Amber M. Kennon
- Department of Investigational Cancer, Division of Cancer Medicine, U.T.M.D Anderson Cancer Center, Houston, TX 77030, USA
| | - James A. Stewart
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS 38677, USA
- Correspondence: ; Tel.: +1-(662)-915-2309
| |
Collapse
|
2
|
Kennon AM, Stewart JA. RAGE Differentially Altered in vitro Responses in Vascular Smooth Muscle Cells and Adventitial Fibroblasts in Diabetes-Induced Vascular Calcification. Front Physiol 2021; 12:676727. [PMID: 34163373 PMCID: PMC8215351 DOI: 10.3389/fphys.2021.676727] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
The Advanced Glycation End-Products (AGE)/Receptor for AGEs (RAGE) signaling pathway exacerbates diabetes-mediated vascular calcification (VC) in vascular smooth muscle cells (VSMCs). Other cell types are involved in VC, such as adventitial fibroblasts (AFBs). We hope to elucidate some of the mechanisms responsible for differential signaling in diabetes-mediated VC with this work. This work utilizes RAGE knockout animals and in vitro calcification to measure calcification and protein responses. Our calcification data revealed that VSMCs calcification was AGE/RAGE dependent, yet AFBs calcification was not an AGE-mediated RAGE response. Protein expression data showed VSMCs lost their phenotype marker, α-smooth muscle actin, and had a higher RAGE expression over non-diabetics. RAGE knockout (RKO) VSMCs did not show changes in phenotype markers. P38 MAPK, a downstream RAGE-associated signaling molecule, had significantly increased activation with calcification in both diabetic and diabetic RKO VSMCs. AFBs showed a loss in myofibroblast marker, α-SMA, due to calcification treatment. RAGE expression decreased in calcified diabetic AFBs, and P38 MAPK activation significantly increased in diabetic and diabetic RKO AFBs. These findings point to potentially an alternate receptor mediating the calcification response in the absence of RAGE. Overall, VSMCs and AFBs respond differently to calcification and the application of AGEs.
Collapse
Affiliation(s)
- Amber M Kennon
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Mississippi, MS, United States
| | - James A Stewart
- Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Mississippi, MS, United States
| |
Collapse
|
3
|
Icer MA, Gezmen-Karadag M. The multiple functions and mechanisms of osteopontin. Clin Biochem 2018; 59:17-24. [PMID: 30003880 DOI: 10.1016/j.clinbiochem.2018.07.003] [Citation(s) in RCA: 316] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/03/2018] [Accepted: 07/08/2018] [Indexed: 12/12/2022]
Abstract
Osteopontin (OPN) is a highly phosphorylated glycophosphoprotein having acidic characteristics and rich in aspartic acid. OPN, a multifunctional protein, has important functions on cardiovascular diseases, cancer, diabetes and kidney stone diseases and in the process of inflammation, biomineralization, cell viability and wound healing. Osteopontin acts on organisms by playing a key role in secretion levels of interleukin-10 (IL-10), interleukin-12 (IL-12), interleukin-3 (IL-3), interferon-γ (IFN-γ), integrin αvB3, nuclear factor kappa B (NF-kB), macrophage and T cells, regulating the osteoclast function and affecting CD44 receptors. The aim of the present review is to address majority of different functions of OPN protein which are known, suspected or suggested through the data obtained about this protein yet.
Collapse
Affiliation(s)
- Mehmet Arif Icer
- Gazi University, Faculty of Health Sciences, Nutrition and Dietetics Department, 06500 Beşevler, Ankara, Turkey.
| | - Makbule Gezmen-Karadag
- Gazi University, Faculty of Health Sciences, Nutrition and Dietetics Department, 06500 Beşevler, Ankara, Turkey.
| |
Collapse
|
4
|
Bendix EF, Johansen E, Ringgaard T, Wolder M, Starup-Linde J. Diabetes and Abdominal Aortic Calcification-a Systematic Review. Curr Osteoporos Rep 2018; 16:42-57. [PMID: 29380116 DOI: 10.1007/s11914-018-0418-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE OF REVIEW A systematic literature review was performed to evaluate diabetes mellitus (DM) as a risk factor of abdominal aortic calcification (AAC), and address factors that might contribute to the development of AAC in DM patients. RECENT FINDINGS DM is an independent risk factor of AAC development. Bone metabolism along with lifestyle factors among DM patients makes them more prone to AAC. Hip and vertebral fractures, high phosphate, smoking, hypertension, and low osteocalcin could make DM patients prone to AAC. Low levels of high-density lipoprotein (HDL), high low-density lipoprotein (LDL), high total cholesterol/HDL ratio, low bone mineral density (BMD) may be risk factors, but the literature is more ambiguous. Body mass index (BMI) does not appear to increase risk of AAC. High phosphate levels and low osteocalcin levels seem to be biomarkers of AAC in patients with diabetes. However, the association between DM and AAC is complicated.
Collapse
Affiliation(s)
- Emilie Frey Bendix
- Department of Endocrinology, Aalborg University Hospital, Mølleparkvej 4, 9220, Aalborg Øst, Denmark
- Faculty of Health, Aalborg University, Niels Jernes Vej 10, 9220, Aalborg Øst, Denmark
| | - Eskild Johansen
- Department of Endocrinology, Aalborg University Hospital, Mølleparkvej 4, 9220, Aalborg Øst, Denmark
- Faculty of Health, Aalborg University, Niels Jernes Vej 10, 9220, Aalborg Øst, Denmark
| | - Thomas Ringgaard
- Department of Endocrinology, Aalborg University Hospital, Mølleparkvej 4, 9220, Aalborg Øst, Denmark
- Faculty of Health, Aalborg University, Niels Jernes Vej 10, 9220, Aalborg Øst, Denmark
| | - Martin Wolder
- Department of Endocrinology, Aalborg University Hospital, Mølleparkvej 4, 9220, Aalborg Øst, Denmark
- Faculty of Health, Aalborg University, Niels Jernes Vej 10, 9220, Aalborg Øst, Denmark
| | - Jakob Starup-Linde
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Tage Hansens Gade 2, 8000, Aarhus C, Denmark.
| |
Collapse
|
5
|
Is Osteopontin a Friend or Foe of Cell Apoptosis in Inflammatory Gastrointestinal and Liver Diseases? Int J Mol Sci 2017; 19:ijms19010007. [PMID: 29267211 PMCID: PMC5795959 DOI: 10.3390/ijms19010007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 12/11/2017] [Accepted: 12/19/2017] [Indexed: 12/15/2022] Open
Abstract
Osteopontin (OPN) is involved in a variety of biological processes, including bone remodeling, innate immunity, acute and chronic inflammation, and cancer. The expression of OPN occurs in various tissues and cells, including intestinal epithelial cells and immune cells such as macrophages, dendritic cells, and T lymphocytes. OPN plays an important role in the efficient development of T helper 1 immune responses and cell survival by inhibiting apoptosis. The association of OPN with apoptosis has been investigated. In this review, we described the role of OPN in inflammatory gastrointestinal and liver diseases, focusing on the association of OPN with apoptosis. OPN changes its association with apoptosis depending on the type of disease and the phase of disease activity, acting as a promoter or a suppressor of inflammation and inflammatory carcinogenesis. It is essential that the roles of OPN in those diseases are elucidated, and treatments based on its mechanism are developed.
Collapse
|
6
|
Ito M, Makino N, Matsuda A, Ikeda Y, Kakizaki Y, Saito Y, Ueno Y, Kawata S. High Glucose Accelerates Cell Proliferation and Increases the Secretion and mRNA Expression of Osteopontin in Human Pancreatic Duct Epithelial Cells. Int J Mol Sci 2017; 18:ijms18040807. [PMID: 28417915 PMCID: PMC5412391 DOI: 10.3390/ijms18040807] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/05/2017] [Accepted: 04/08/2017] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND The incidence of pancreatic cancer is increasing year-by-year in Japan. Among the diseases that complicate pancreatic cancer, diabetes is the most common. Recently, it has become evident that patients suffering from diabetes and obesity show increased expression of osteopontin (OPN). The purpose of this study was to investigate the effect of high glucose and high insulin culture conditions on a human pancreatic duct epithelial cell line (HPDE-6), focusing particularly on OPN expression. METHODS HPDE-6 were cultured under various conditions, employing several combinations of glucose (normal, 6 mM high, 30 mM, and 60 mM) and insulin (0.1 nM, 1 nM) concentration. RESULTS HPDE-6 cell proliferation was significantly accelerated under high glucose culture conditions in comparison to samples in 6 mM glucose, and was more prominent under high insulin conditions. At the same time, the expression of OPN mRNA was also increased significantly. In comparison with 6 mM glucose, the expression of 8-OHdG DNA was increased in high glucose culture. CONCLUSION HPDE-6 cells show accelerated proliferation and increased OPN expression when cultured under high glucose and high insulin conditions. Furthermore, the cells show increased oxidative stress in the presence of high glucose.
Collapse
Affiliation(s)
- Miho Ito
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Naohiko Makino
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Akiko Matsuda
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Yushi Ikeda
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Yasuharu Kakizaki
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Yoshihiko Saito
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Yoshiyuki Ueno
- Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585, Japan.
| | - Sumio Kawata
- Hyogo Prefectural Nishinomiya Hospital, Nishinomiya 662-0918, Japan.
| |
Collapse
|
7
|
Osteopontin in relation to Prognosis following Coronary Artery Bypass Graft Surgery. DISEASE MARKERS 2016; 2016:1868739. [PMID: 27597799 PMCID: PMC5002285 DOI: 10.1155/2016/1868739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/18/2016] [Indexed: 11/22/2022]
Abstract
Cardiovascular events may occur even after complete revascularization in patients with coronary artery disease. We measured preoperative osteopontin (OPN) levels in 131 consecutive patients (66.5 ± 10 years old, 117 men and 14 women) with left ventricular ejection fraction of 50.7 ± 9.2% and low logistic EuroScore (3.5 ± 3.2%) undergoing elective Coronary Artery Bypass Grafting (CABG) surgery. Patients were prospectively followed up for a median of 12 months (range 11–24). The primary study endpoint was the composite of cardiovascular death, nonfatal myocardial infarction, need for repeat revascularization, and hospitalization for cardiovascular events. Pre-op OPN plasma levels were 77.9 (49.5, 150.9). Patients with prior acute myocardial infarction (AMI) had significantly higher OPN levels compared to those without [131.5 (52.2, 219) versus 73.3 (45.1, 125), p = 0.007]. OPN levels were positively related to EuroScore (r = 0.2, p = 0.031). Pre-op OPN levels did not differ between patients who had a major adverse event during follow-up compared to those with no event (p = 0.209) and had no effect on the hazard of future adverse cardiac events [HR (95% CI): 1.48 (0.43–4.99), p = 0.527]. The history of AMI was associated with increased risk of subsequent cardiovascular events at follow-up (p = 0.02). OPN is associated with preoperative risk assessment prior to low-risk CABG but did not independently predict outcome.
Collapse
|
8
|
Kay AM, Simpson CL, Stewart JA. The Role of AGE/RAGE Signaling in Diabetes-Mediated Vascular Calcification. J Diabetes Res 2016; 2016:6809703. [PMID: 27547766 PMCID: PMC4980539 DOI: 10.1155/2016/6809703] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/19/2016] [Indexed: 11/26/2022] Open
Abstract
AGE/RAGE signaling has been a well-studied cascade in many different disease states, particularly diabetes. Due to the complex nature of the receptor and multiple intersecting pathways, the AGE/RAGE signaling mechanism is still not well understood. The purpose of this review is to highlight key areas of AGE/RAGE mediated vascular calcification as a complication of diabetes. AGE/RAGE signaling heavily influences both cellular and systemic responses to increase bone matrix proteins through PKC, p38 MAPK, fetuin-A, TGF-β, NFκB, and ERK1/2 signaling pathways in both hyperglycemic and calcification conditions. AGE/RAGE signaling has been shown to increase oxidative stress to promote diabetes-mediated vascular calcification through activation of Nox-1 and decreased expression of SOD-1. AGE/RAGE signaling in diabetes-mediated vascular calcification was also attributed to increased oxidative stress resulting in the phenotypic switch of VSMCs to osteoblast-like cells in AGEs-induced calcification. Researchers found that pharmacological agents and certain antioxidants decreased the level of calcium deposition in AGEs-induced diabetes-mediated vascular calcification. By understanding the role the AGE/RAGE signaling cascade plays diabetes-mediated vascular calcification will allow for pharmacological intervention to decrease the severity of this diabetic complication.
Collapse
Affiliation(s)
- Amber M. Kay
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - C. LaShan Simpson
- Department of Agricultural and Biological Engineering, Mississippi State University, Mississippi State, MS 39762, USA
| | - James A. Stewart
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| |
Collapse
|
9
|
Fu Q, Colgan SP, Shelley CS. Hypoxia: The Force that Drives Chronic Kidney Disease. Clin Med Res 2016; 14:15-39. [PMID: 26847481 PMCID: PMC4851450 DOI: 10.3121/cmr.2015.1282] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 09/30/2015] [Indexed: 12/15/2022]
Abstract
In the United States the prevalence of end-stage renal disease (ESRD) reached epidemic proportions in 2012 with over 600,000 patients being treated. The rates of ESRD among the elderly are disproportionally high. Consequently, as life expectancy increases and the baby-boom generation reaches retirement age, the already heavy burden imposed by ESRD on the US health care system is set to increase dramatically. ESRD represents the terminal stage of chronic kidney disease (CKD). A large body of evidence indicating that CKD is driven by renal tissue hypoxia has led to the development of therapeutic strategies that increase kidney oxygenation and the contention that chronic hypoxia is the final common pathway to end-stage renal failure. Numerous studies have demonstrated that one of the most potent means by which hypoxic conditions within the kidney produce CKD is by inducing a sustained inflammatory attack by infiltrating leukocytes. Indispensable to this attack is the acquisition by leukocytes of an adhesive phenotype. It was thought that this process resulted exclusively from leukocytes responding to cytokines released from ischemic renal endothelium. However, recently it has been demonstrated that leukocytes also become activated independent of the hypoxic response of endothelial cells. It was found that this endothelium-independent mechanism involves leukocytes directly sensing hypoxia and responding by transcriptional induction of the genes that encode the β2-integrin family of adhesion molecules. This induction likely maintains the long-term inflammation by which hypoxia drives the pathogenesis of CKD. Consequently, targeting these transcriptional mechanisms would appear to represent a promising new therapeutic strategy.
Collapse
Affiliation(s)
- Qiangwei Fu
- Kabara Cancer Research Institute, La Crosse, WI
| | - Sean P Colgan
- Mucosal Inflammation Program and University of Colorado School of Medicine, Aurora, CO
| | - Carl Simon Shelley
- University of Wisconsin School of Medicine and Public Health, Madison, WI
| |
Collapse
|
10
|
Nagao T, Okura T, Irita J, Jotoku M, Enomoto D, Desilva VR, Miyoshi KI, Kurata M, Matsui Y, Uede T, Higaki J. Osteopontin plays a critical role in interstitial fibrosis but not glomerular sclerosis in diabetic nephropathy. NEPHRON EXTRA 2012; 2:87-103. [PMID: 22619671 PMCID: PMC3346163 DOI: 10.1159/000337330] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND/AIMS Osteopontin (OPN) has been implicated in the pathology of several renal conditions. The aim of this study was to clarify the roles of OPN in diabetic nephropathy. METHODS Diabetes mellitus (DM) was induced in wild-type (WT) and OPN knockout (KO) mice by injecting streptozotocin. The mice were killed 20 weeks after induction of DM and their kidneys removed. RESULTS Renal mRNA expression of OPN was increased in WT-DM mice compared to WT-sham mice. Immunohistochemistry showed high levels of OPN expression in the proximal tubules of WT-DM mice. Kidney weight and urinary albumin excretion increased to similar levels in the WT-DM and KO-DM mice. Interstitial fibrosis was increased in WT-DM mice compared to KO-DM mice. However, there were no differences in the degree of mesangial expansion or glomerular hypertrophy between the two groups. F4/80-positive cells (macrophages) and FSP-1-positive cells (fibroblasts) showed significantly higher infiltration in WT-DM mice than in KO-DM mice. Renal mRNA expression of NADPH oxidase subunits and urinary 8-isoprostane excretion were also increased in WT-DM mice. CONCLUSIONS These results indicated that OPN is a key molecule that induces interstitial fibrosis in the diabetic kidney, but does not induce glomerular sclerosis.
Collapse
Affiliation(s)
- Tomoaki Nagao
- Department of Integrated Medicine and Informatics, Ehime University Graduate School of Medicine, Ehime, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Nilsson BO, Olde B, Leeb-Lundberg LMF. G protein-coupled oestrogen receptor 1 (GPER1)/GPR30: a new player in cardiovascular and metabolic oestrogenic signalling. Br J Pharmacol 2011; 163:1131-9. [PMID: 21250980 DOI: 10.1111/j.1476-5381.2011.01235.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Oestrogens are important sex hormones central to health and disease in both genders that have protective effects on the cardiovascular and metabolic systems. These hormones act in complex ways via both genomic and non-genomic mechanisms. The genomic mechanisms are relatively well characterized, whereas the non-genomic ones are only beginning to be explored. Two oestrogen receptors (ER), ERα and ERβ, have been described that act as nuclear transcription factors but can also associate with the plasma membrane and influence cytosolic signalling. ERα has been shown to mediate both anti-atherogenic effects and pro-survival effects in pancreatic β-cells. In recent years, a third membrane-bound ER has emerged, G protein-coupled receptor 30 or G protein-coupled oestrogen receptor 1 (GPER1), which mediates oestrogenic responses in cardiovascular and metabolic regulation. Both GPER1 knock-out models and pharmacological agents are now available to study GPER1 function. These tools have revealed that GPER1 activation may have several beneficial effects in the cardiovascular system including vasorelaxation, inhibition of smooth muscle cell proliferation, and protection of the myocardium against ischaemia/reperfusion injury, and in the metabolic system including stimulation of insulin release and protection against pancreatic β-cell apoptosis. Thus, GPER1 is emerging as a candidate therapeutic target in both cardiovascular and metabolic disease.
Collapse
Affiliation(s)
- Bengt-Olof Nilsson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | | | | |
Collapse
|
12
|
Jahns F, Wilhelm A, Jablonowski N, Mothes H, Radeva M, Wölfert A, Greulich KO, Glei M. Butyrate suppresses mRNA increase of osteopontin and cyclooxygenase-2 in human colon tumor tissue. Carcinogenesis 2011; 32:913-20. [PMID: 21459756 DOI: 10.1093/carcin/bgr061] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The short chain fatty acid (SCFA) butyrate, a product of fermentation of dietary fiber in the human colon, is found to exert multiple regulatory processes in colon carcinogenesis. The aim of this study was to find out whether butyrate affects the tumor-promoting genes osteopontin (OPN) and cyclooxygenase (COX)-2, their respective proteins and/or their functional activity in matched normal, adenoma and tumor colon tissues obtained from 20 individuals at colon cancer surgery. Quantitative real-time polymerase chain reaction experiments showed increased levels of OPN and COX-2 messenger RNA in tumor tissues when compared with the adjacent normal samples (P < 0.001). The addition of butyrate reduced OPN and COX-2 mRNA expression in all tissue types compared with the related medium controls (tumor: P < 0.05). In tumor samples, a downregulation of up to median 35% (COX-2) and 50% (OPN) was observed, respectively. Thereby, tumors with lower levels of OPN basal expression were more sensitive to inhibition and vice versa for COX-2 in normal tissue. At the protein and enzyme level, which were determined by using western blot and enzyme immunometric assays, the impact of the SCFA was not clearly visible anymore. The active proteins of OPN and COX-2 (determined by prostaglandin E(2)) were found to correlate with their respective mRNA expression only in 50-63% of analyzed donors. For the first time, our data reveal new insights into the chemoprotective potential of butyrate by showing the suppression of OPN and COX-2 mRNA in primary human colon tissue with the strongest effects observed in tumors.
Collapse
Affiliation(s)
- F Jahns
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich-Schiller-University Jena, Dornburger Straße 24, 07743 Jena, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Yan X, Sano M, Lu L, Wang W, Zhang Q, Zhang R, Wang L, Chen Q, Fukuda K, Shen W. Plasma concentrations of osteopontin, but not thrombin-cleaved osteopontin, are associated with the presence and severity of nephropathy and coronary artery disease in patients with type 2 diabetes mellitus. Cardiovasc Diabetol 2010; 9:70. [PMID: 21034455 PMCID: PMC2988001 DOI: 10.1186/1475-2840-9-70] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Accepted: 10/29/2010] [Indexed: 12/17/2022] Open
Abstract
Background The aim of the present cross-sectional study was to assess possible associations between osteopontin (OPN), and thrombin-cleaved (N-half) OPN, and nephropathy and coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM). Methods Plasma levels of OPN, N-half OPN, and high-sensitivity C-reactive protein (hsCRP) were determined in 301 diabetic patients with (n = 226) or without (n = 75) angiographically documented CAD (luminal diameter narrowing >50%), as well as in 75 non-diabetic controls with normal angiography. The estimated glomerular filtration rate (eGFR) was calculated in all patients. Results Plasma levels of OPN and hsCRP were significantly higher in patients with T2DM compared with controls. In addition, there was a higher occurrence of moderate renal insufficiency and lower eGFR in patients with T2DM (all P < 0.01). T2DM patients in whom OPN levels were greater than the median value had higher serum creatinine levels, a greater prevalence of mild or moderate renal insufficiency, a higher incidence of CAD, and lower eGFR (all P < 0.05) than T2DM patients in whom OPN levels were the same as or lower than the median value. However, there were no differences in these parameters when patients were stratified according to plasma N-half OPN levels. Furthermore, there was a significant correlation between OPN, but not N-half OPN, and the severity of nephropathy and CAD in diabetes. After adjustment for potential confounders and treatments, multiple linear regression analysis demonstrated an independent association between OPN, but not N-half OPN, and eGFR. Multivariate logistic regression revealed that higher OPN levels conferred a fourfold greater risk of renal insufficiency and CAD in patients with T2DM. Conclusions The results of the present study demonstrate that there is an independent association between plasma levels of OPN, but not N-half OPN, and the presence and severity of nephropathy and CAD in diabetes.
Collapse
Affiliation(s)
- Xiaoxiang Yan
- Department of Cardiology, Rui Jin Hospital, Jiaotong University School of Medicine, Shanghai, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Maile LA, Capps BE, Ling Y, Xi G, Clemmons DR. Hyperglycemia alters the responsiveness of smooth muscle cells to insulin-like growth factor-I. Endocrinology 2007; 148:2435-43. [PMID: 17255202 DOI: 10.1210/en.2006-1440] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
IGF-I stimulation of smooth muscle cell (SMC) migration and proliferation requires alphaVbeta3 ligand occupancy. We hypothesized that changes in the levels of extracellular matrix proteins induced by alterations in glucose concentrations may regulate the ability of SMCs to respond to IGF-I. IGF-I stimulated migration and proliferation of SMCs that had been maintained in 25 mM glucose containing media, but it had no stimulatory effect when tested using SMCs that had been grown in 5 mM glucose. IGF-I stimulated an increase in Shc phosphorylation and enhanced activation of the MAPK pathway in SMCs grown in 25 mM glucose, whereas in cells maintained in 5 mM glucose, IGF-I had no effect on Shc phosphorylation, and the MAPK response to IGF-I was markedly reduced. In cells grown in 25 mM glucose, the levels of alphaVbeta3 ligands, e.g. osteopontin, vitronectin, and thrombospondin, were all significantly increased, compared with cells grown in 5 mM glucose. The addition of these alphaVbeta3 ligands to SMCs grown in 5 mM glucose was sufficient to permit IGF-I-stimulated Shc phosphorylation and downstream signaling. Because we have shown previously that alphaVbeta3 ligand occupancy is required for IGF-I-stimulated Shc phosphorylation and stimulation of SMC growth, our data are consistent with a model in which 25 mM glucose stimulates increases in the concentrations of these extracellular matrix proteins, thus enhancing alphaVbeta3 ligand occupancy, which leads to increased Shc phosphorylation and enhanced cell migration and proliferation in response to IGF-I.
Collapse
Affiliation(s)
- Laura A Maile
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599-7170, USA.
| | | | | | | | | |
Collapse
|
15
|
San Martín A, Du P, Dikalova A, Lassègue B, Aleman M, Góngora MC, Brown K, Joseph G, Harrison DG, Taylor WR, Jo H, Griendling KK. Reactive oxygen species-selective regulation of aortic inflammatory gene expression in Type 2 diabetes. Am J Physiol Heart Circ Physiol 2007; 292:H2073-82. [PMID: 17237245 DOI: 10.1152/ajpheart.00943.2006] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vascular diseases are a major complication of diabetes mellitus (DM), although their etiology is poorly understood. NADPH oxidase-derived reactive oxygen species (ROS) production and inflammation are potential mediators of DM-associated vascular diseases. Using db/db mice as a Type 2 diabetes model, we examined the relationship between NADPH oxidase-derived ROS and vascular inflammation. When compared with control m+/+ mice, aortas from 4- and 12-wk-old db/db mice had higher NADPH oxidase activity and increased superoxide levels, leading to NADPH oxidase-dependent impaired vasodilation at 12 wk. Diabetes progression from 4 to 12 wk led to increased Nox1, Nox4, and p22(phox) subunit mRNAs and induced the expression of a group of matrix remodeling-related cytokines: connective tissue growth factor (CTGF), bone morphogenetic protein 4 (BMP-4), and osteopontin (OPN). After 8 wk of treatment with the superoxide scavenger Tempol, 12-wk-old db/db mice had lower superoxide production, reduced plasma glucose and lipids, and lower BMP-4 and OPN protein expression when compared with nontreated mice. No changes were observed with Tempol in CTGF or m+/+ mice. The ability of Tempol to reverse ROS production as well as OPN and BMP-4, but not CTGF, induction suggests that DM-induced vascular inflammation involves both ROS-sensitive and -insensitive pathways.
Collapse
Affiliation(s)
- Alejandra San Martín
- Division of Cardiology, Department of Medicine, Emory University, 1639 Pierce Dr., Atlanta, GA 30322, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Kato R, Momiyama Y, Ohmori R, Tanaka N, Taniguchi H, Arakawa K, Kusuhara M, Nakamura H, Ohsuzu F. High plasma levels of osteopontin in patients with restenosis after percutaneous coronary intervention. Arterioscler Thromb Vasc Biol 2006; 26:e1-2. [PMID: 16373617 DOI: 10.1161/01.atv.0000194157.26665.e6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
17
|
Liou YM, Chang LY, Liaw JM, Jiang MJ. Osteopontin gene expression in the aorta and the heart of propylthiouracil-induced hypothyroid mice. J Biomed Sci 2005; 12:869-80. [PMID: 16265595 DOI: 10.1007/s11373-005-9023-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Accepted: 08/17/2005] [Indexed: 10/25/2022] Open
Abstract
It is known that there is abnormal osteopontin (OPN) expression at the sites of atherosclerotic lesions. In the Apolipoprotein E gene knockout (ApoE-KO) mouse, a model of the atherosclerotic process, altered cholesterol metabolism with associated increase in OPN expression is evident at 12-22 weeks in the aorta and at 22 weeks in the heart. In this study, we analyzed another animal model of hypothyroid mice created by ingestion of propylthiouracil (PTU). After 2 weeks of PTU ingestion, the animals had significant decreases in thyroid hormones (T3 and T4) and immediate increases in blood lipids/cholesterol. Hypothyroid mice showed 1.3-, 1.5-, 2-fold increases in blood levels of total cholesterol, triglycerides, and low density lipoprotein-cholesterol respectively. Semi-quantitative RT-PCR analysis showed that hypothyroid mice had 1.4- to 2-fold increases of OPN mRNA expression in the aorta and 1.5-fold increases in the heart. Hypothyroid animals treated with T3 (5 microg/day for 6 days) or statin (0.2 mg/30 g for 2 weeks) reduce blood lipids and aortic OPN mRNA expression. Data obtained with ELISA analyses showed 1.5- and 1.7-fold increases in OPN protein in the aorta (10 weeks) and the heart (22 weeks), respectively. This increase is close to the mRNA expression in both tissues of hypothyroid mice. In addition, western blots showed several variants of OPN protein expressed in the aorta and the heart. The decrease in the 70 kDa OPN is accompanied by an increase in 45 kDa OPN in the aorta of hypothyroid mice. In contrast, only 45 kDa OPN is found in the heart of control and hypothyroid mice. These data indicate that the increase of OPN mRNA and protein expression occurs in cardiovascular tissues of hypothyroid mice.
Collapse
Affiliation(s)
- Y M Liou
- Department of Life Science, National Chung-Hsing University, 250 Kuokang Road, Taichung 402, Taiwan. ymlion@dragon. nchu.edu.tw
| | | | | | | |
Collapse
|
18
|
Taylor A, Shaw LJ, Fayad Z, O'Leary D, Brown BG, Nissen S, Rader D, Raggi P. Tracking atherosclerosis regression: a clinical tool in preventive cardiology. Atherosclerosis 2005; 180:1-10. [PMID: 15823269 DOI: 10.1016/j.atherosclerosis.2004.12.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Accepted: 12/16/2004] [Indexed: 11/30/2022]
Abstract
Progression of coronary artery disease was initially evaluated using quantitative coronary angiography with ensuing evidence indicating a strong relationship to adverse cardiovascular outcomes. Since then, several other atherosclerosis imaging techniques have emerged as new tools in cardiovascular medicine to evaluate the effectiveness of preventive therapies through serial monitoring of changes in atherosclerosis burden. Conducting large randomized trials to test new approaches for the medical management of atherosclerosis, with the goal of showing a reduction in event rates, may often be impractical in an era of cost containment and reduced societal resources. Recent evidence has unfolded that investigates alternative ways of assessing therapeutic results such as the attainment of surrogate goals with substantial outcome relevance. Atherosclerosis imaging modalities such as coronary computed tomography, carotid ultrasound, cardiovascular magnetic resonance imaging, and intravascular ultrasound each possess specific imaging abilities and inter-test characteristics that enable their serial use as intermediate endpoints in clinical trials and, increasingly, in individual patient management. The current review focuses on the application of these modalities as emerging tools in cardiovascular prevention.
Collapse
Affiliation(s)
- Allen Taylor
- Walter Reed Army Medical Center, Atlanta, GA, USA
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Junaid A, Amara FM. Osteopontin: correlation with interstitial fibrosis in human diabetic kidney and PI3-kinase-mediated enhancement of expression by glucose in human proximal tubular epithelial cells. Histopathology 2004; 44:136-46. [PMID: 14764057 DOI: 10.1111/j.1365-2559.2004.01771.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIMS To examine the expression and localization of osteopontin (OPN), a secreted phosphoprotein implicated in the development of tubulointerstitial inflammation in various models of renal disease, in human diabetic kidneys, and to study the regulation of OPN expression in primary cultures of human renal proximal tubular epithelial cells (RPTEC). METHODS AND RESULTS Differential gene expression profiling through subtractive hybridization demonstrated increased renal OPN mRNA expression in a patient with diabetic nephropathy. Immunohistochemical staining of normal and diabetic human kidney samples confirmed that OPN was localized to cortical tubular, interstitial and juxtaglomerular compartments. Quantification of OPN immunostaining revealed a marked increase in the percentage of OPN-positive tubular profiles in diabetic kidneys (47 +/- 9% versus 5 +/- 3%, diabetic versus minimal change disease) that correlated strongly with the degree of cortical scarring (r2 = 0.91). Results of Northern hybridization, flow cytometry and Western blotting indicated that glucose up-regulates OPN mRNA and protein expression in primary cultures of human RPTECs. This effect was independent of the osmotic effects of glucose and independent of insulin. Finally, glucose-stimulated OPN expression was inhibited by LY294002, an inhibitor of phosphatidylinositol 3-kinase activity, in a dose-dependent manner. CONCLUSIONS OPN is expressed in human diabetic kidneys and regulation of OPN expression is via a glucose-mediated, phosphatidylinositol 3-kinase-dependent pathway.
Collapse
MESH Headings
- Aged
- Amino Acid Sequence
- Blotting, Northern
- Blotting, Western
- Cells, Cultured
- Diabetic Nephropathies/complications
- Diabetic Nephropathies/metabolism
- Diabetic Nephropathies/pathology
- Enzyme Inhibitors/pharmacology
- Epithelial Cells/drug effects
- Epithelial Cells/metabolism
- Epithelial Cells/pathology
- Fibrosis/etiology
- Fibrosis/metabolism
- Fibrosis/pathology
- Flow Cytometry
- Gene Expression Profiling
- Glucose/pharmacology
- Humans
- Immunohistochemistry
- In Situ Hybridization
- Kidney Tubules, Proximal/drug effects
- Kidney Tubules, Proximal/metabolism
- Kidney Tubules, Proximal/pathology
- Male
- Molecular Sequence Data
- Nephritis, Interstitial/metabolism
- Nephritis, Interstitial/pathology
- Osteopontin
- Phosphatidylinositol 3-Kinases/drug effects
- Phosphatidylinositol 3-Kinases/metabolism
- RNA, Messenger/analysis
- Sequence Homology, Amino Acid
- Sialoglycoproteins/drug effects
- Sialoglycoproteins/metabolism
Collapse
Affiliation(s)
- A Junaid
- Department of Internal Medicine, University of Manitoba and St Boniface Hospital Research Centre, Winnipeg, Canada.
| | | |
Collapse
|
20
|
Abstract
Current vital statistics clearly indicate a continuing epidemic of cardiovascular disease in the Western hemisphere and strongly suggest that the most desirable approach to this ailment is prevention rather than delayed treatment. Over 7 million people in the United States suffer from coronary artery disease and more than 500,000 die from its complications annually. In the majority of cases, the event announcing the presence of atherosclerosis is either sudden death or a disabling myocardial infarction or stroke. Though recent trials indicate a need for treatment of very large segments of the population, a review of current clinical practices indicates that the preventive attitude of the majority of physicians is not sufficiently developed and remains limited in most training programs. Additionally, although traditional risk factors are very helpful in predicting the development of cardiovascular disease, many individuals suffer events in the absence of established risk factors for atherosclerosis. To meet the challenge of coronary artery disease, several tools have been developed to identify atherosclerotic disease in its preclinical stages, with the hope of modifying its natural history. In this article, we review the current literature on utilization of electron beam tomography for detection of coronary artery calcification as a tool to conduct risk stratification for coronary artery disease events in the general population.
Collapse
Affiliation(s)
- Paolo Raggi
- Section of Cardiology, Tulane University School of Medicine, 1430 Tulane Avenue, SL48, New Orleans, LA 70112-2699, USA.
| | | |
Collapse
|
21
|
Kawamura H, Yokote K, Asaumi S, Kobayashi K, Fujimoto M, Maezawa Y, Saito Y, Mori S. High glucose-induced upregulation of osteopontin is mediated via Rho/Rho kinase pathway in cultured rat aortic smooth muscle cells. Arterioscler Thromb Vasc Biol 2003; 24:276-81. [PMID: 14670931 DOI: 10.1161/01.atv.0000112012.33770.2a] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Osteopontin is upregulated in the diabetic vascular wall and in vascular smooth muscle cells cultured under high glucose concentration. In the present study, we analyzed the mechanism of high glucose-induced upregulation of osteopontin in cultured rat aortic smooth muscle cells. METHODS AND RESULTS We found that an inhibitor of Rho-associated protein kinase, Y-27632, suppressed osteopontin mRNA expression under high glucose concentration. Transfection of cells with a constitutive active Rho mutant, pSRalpha-myc-RhoDA, enhanced osteopontin mRNA expression. Furthermore, incubation of cells under high glucose concentration activated Rho, indicating that Rho/Rho kinase pathway mediates high-glucose-stimulated osteopontin expression. Treatment of cells with an inhibitor of protein kinase C, GF109203X, and azaserine, an inhibitor of the hexosamine pathway, suppressed high glucose-induced Rho activation. Glucosamine treatment was shown to activate Rho. Treatment of cells with an inhibitor of MEK1, PD98059, suppressed osteopontin mRNA expression under high glucose concentration. Incubation of cells under high glucose concentration activated ERK. Finally, transfection of cells with pSRalpha-myc-RhoDA also activated ERK. CONCLUSIONS In conclusion, our present findings support a notion that Rho/Rho kinase pathway functions downstream of protein kinase C and the hexosamine pathways and upstream of ERK in mediating high-glucose-induced upregulation of osteopontin expression.
Collapse
Affiliation(s)
- Harukiyo Kawamura
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670, Japan
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Abstract
Over 7 million people in this country have coronary artery disease, and more than 500,000 die from its complications annually. Over 1 million Americans have an acute myocardial infarction each year, and in the majority of cases the event announcing the presence of coronary atherosclerosis is either sudden death or a disabling myocardial infarction. Therefore, the most desirable approach to such an epidemic is prevention rather than delayed treatment. Yet, statistics from primary care and subspecialty practices indicate that the preventive attitude of the majority of physicians is not sufficiently developed and remains limited in most training programs. Though traditional risk factors are very helpful in predicting the development of cardiovascular disease, many individuals suffer events in the absence of established risk factors for atherosclerosis. To meet the challenge of coronary artery disease, several tools have been developed to identify atherosclerotic disease in its preclinical stages in the hope of modifying its natural history. This review deals with the utilization of electron beam tomography for detection of coronary artery calcification as an additional tool available for use by preventive cardiologists and internists.
Collapse
Affiliation(s)
- Paolo Raggi
- Section of Cardiology, Tulane University School of Medicine, New Orleans, LA 70112-2699, USA.
| |
Collapse
|
23
|
Beck GR, Knecht N. Osteopontin regulation by inorganic phosphate is ERK1/2-, protein kinase C-, and proteasome-dependent. J Biol Chem 2003; 278:41921-9. [PMID: 12920127 DOI: 10.1074/jbc.m304470200] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The generation of inorganic phosphate by alkaline phosphatase during osteoblast differentiation represents an important signaling event, although the molecular and cellular consequences are currently undefined. We have previously described osteopontin as a gene regulated by an increase in inorganic phosphate not only in osteoblasts but also in other cell types. We describe here the identification of specific signaling pathways required for the stimulation of osteopontin expression by inorganic phosphate. We have determined that phosphate selectively activates the extracellular signal-regulated kinase (ERK1/2) signaling pathway but does not activate the other mitogen-activated protein kinase signaling proteins, p38, or the c-Jun N-terminal kinase. In addition, our results suggest that cellular exposure to 10 mm inorganic phosphate causes a biphasic ERK1/2 activation. The second ERK1/2 activation is required for osteopontin regulation, whereas the first is not sufficient. Analysis of common protein kinase families has revealed that phosphate-induced osteopontin expression specifically uses a protein kinase C-dependent signaling pathway. In addition, our results suggest that protein kinase C and ERK1/2 are not part of the same pathway but constitute two distinct pathways. Finally, we have determined that the proteasomal activity is required not only for phosphate-induced expression of osteopontin but also for the induction of osteopontin in response to 12-O-tetradecanoylphorbol 13-acetate and okadaic acid. The data presented here define for the first time the ability of increased inorganic phosphate to stimulate specific signaling pathways resulting in functionally significant changes in gene expression and identify three important signaling pathways in the regulation of osteopontin.
Collapse
Affiliation(s)
- George R Beck
- National Cancer Institute-Frederick, Center for Cancer Research, Basic Research Laboratory, Bldg. 576 Rm. 110, Frederick, MD 21702, USA.
| | | |
Collapse
|
24
|
Ohmori R, Momiyama Y, Taniguchi H, Takahashi R, Kusuhara M, Nakamura H, Ohsuzu F. Plasma osteopontin levels are associated with the presence and extent of coronary artery disease. Atherosclerosis 2003; 170:333-7. [PMID: 14612215 DOI: 10.1016/s0021-9150(03)00298-3] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recently, osteopontin (OPN) mRNA was reported to be highly expressed in atherosclerotic plaques, most strikingly in calcified plaques. We examined if plasma OPN levels are associated with coronary stenosis and calcification in patients with coronary artery disease (CAD). We measured plasma OPN levels in 178 patients undergoing coronary angiography. Compared with 71 patients without CAD, 107 with CAD had higher OPN levels (616+/-308 ng/ml versus 443+/-237 ng/ml, P<0.001). A stepwise increase in OPN levels was found depending on the number of >50% stenotic coronary vessels: 540+/-293 ng/ml in 1-vessel, 615+/-230 ng/ml in 2-vessel, and 758+/-416 ng/ml in 3-vessel disease. OPN levels also correlated with the numbers of >50% and >25% stenotic segments (r=0.35 and 0.43, respectively, P<0.001). In multivariate analysis, OPN levels were significantly associated with CAD (odds ratio=1.21, 95% CI=1.05-1.39 for a 100 ng/ml increase) independent of traditional risk factors. Coronary calcification was found in 86 patients. OPN levels were higher in patients with calcification than in those without calcification (608+/-328 ng/ml versus 490+/-246 ng/ml, P<0.01) and correlated with the number of calcified segment (r=0.26, P<0.001). However, OPN levels were not independently associated with coronary calcification. Thus, plasma OPN levels were found to be associated with the presence and extent of CAD.
Collapse
Affiliation(s)
- Reiko Ohmori
- First Department of Internal Medicine, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | | | | | | | | | | | | |
Collapse
|
25
|
Fujimoto M, Maezawa Y, Yokote K, Joh K, Kobayashi K, Kawamura H, Nishimura M, Roberts AB, Saito Y, Mori S. Mice lacking Smad3 are protected against streptozotocin-induced diabetic glomerulopathy. Biochem Biophys Res Commun 2003; 305:1002-7. [PMID: 12767930 DOI: 10.1016/s0006-291x(03)00885-4] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Transforming growth factor-beta (TGF-beta) has been implicated in the development of diabetic glomerulopathy. In order to evaluate a role of Smad3, one of the major signaling molecules downstream of TGF-beta, in the pathogenesis of diabetic glomerulopathy, Smad3-null mice were made diabetic with streptozotocin injection and analyzed 4 weeks after induction of diabetes. Electron microscopy revealed that the thickness of glomerular basement membrane (GBM) in wild-type diabetic mice was significantly higher than that in non-diabetic mice, whereas no appreciable GBM thickening was found in Smad3-null diabetic mice. Urinary albumin excretion was dramatically increased in wild-type diabetic mice, whereas Smad3-null diabetic mice did not show any overt albuminuria. Northern blotting revealed that mRNA levels of fibronectin and alpha 3 chain of type IV collagen (alpha 3Col4) in renal cortex of wild-type diabetic mice were approximately twice as much as those of non-diabetic mice, whereas their mRNA levels were not increased in Smad3-null diabetic mice. Real-time polymerase chain reaction (PCR) also confirmed diabetes-induced upregulation of fibronectin and alpha 3Col4 in glomeruli of wild-type mice. Glomerular expression of TGF-beta 1, as assessed by real-time PCR, was enhanced to a similar degree in wild-type and smad3-null diabetic mice, indicating that the observed differences between wild-type and Smad3-null mice are not attributable to difference in the expression of TGF-beta 1. These data clearly demonstrate a critical role of Smad3 in the early phase of diabetic glomerulopathy. This may be due at least partly to the present findings that diabetes-induced upregulation of fibronectin and alpha 3Col4 is dependent on Smad3 function.
Collapse
Affiliation(s)
- Masaki Fujimoto
- Department of Clinical Cell Biology and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chiba 260-8670, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
Diabetes is associated with an increased prevalence of atherosclerotic vascular disease and cardiovascular mortality. In diabetic patients, medial calcification appears to be a strong independent predictor of cardiovascular mortality, it occurs particularly in those with neuropathy. Recent evidence suggests that medial calcification in diabetes is an active, cell-mediated process, similar to that observed in patients with end-stage renal disease (ESRD), in which vascular smooth muscle cells (VSMCs) express a number of bone matrix proteins that act to either facilitate or regulate the calcification process. Several bone-associated proteins (e.g., osteopontin, bone sialoprotein, alkaline phosphatase, type 1 collagen, osteocalcin) have been demonstrated in histologic sections of vessels obtained from patients with diabetes or ESRD. In in vitro experiments, high glucose induced cell proliferation and expression of osteopontin in cultured VSMCs. Hypoxia had additive effects of hyperglycemia on VSMCs. In addition, uremic serum upregulates osteoblast transcription factor Cbfa 1 and osteopontin expression in cultured VSMCs. The pathogenesis of vascular calcification in diabetes is not completely understood, although high glucose and other potential factors may play an important role by transforming VSMCs into osteoblast-like cells. Further understanding of the mechanism by which diabetes induces this complication is needed to design effective therapeutic strategies to intervene with this process.
Collapse
Affiliation(s)
- Neal X Chen
- Department of Medicine, Indiana University School of Medicine, 1001 West 10th Street, OPW 526, Indianapolis, IN 46202, USA.
| | | |
Collapse
|
27
|
Asaumi S, Takemoto M, Yokote K, Ridall AL, Butler WT, Fujimoto M, Kobayashi K, Kawamura H, Take A, Saito Y, Mori S. Identification and characterization of high glucose and glucosamine responsive element in the rat osteopontin promoter. J Diabetes Complications 2003; 17:34-8. [PMID: 12505755 DOI: 10.1016/s1056-8727(02)00189-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have previously reported that high glucose stimulates osteopontin (OPN) expression via a protein kinase C-dependent pathway and a hexosamine pathway in cultured rat aortic smooth muscle cells (SMCs) [Biochem. Biophys. Res. Commun. 258 (1999) 722.]. In the present study, we carried out functional OPN promoter assays using the luciferase expression vector system in cultured rat aortic SMCs to determine a high glucose/glucosamine responsive element. An extensive deletion analysis of the 5'-flanking region of the rat OPN gene revealed that an element involved in high glucose and glucosamine responses was present within a region between -112 and -62 bp of the OPN promoter. This region is highly conserved in the rat, mouse, and human promoters and contains a number of consensus regions, including an E-box and a GC-rich region. Mutation of the E-box or the GC-rich region resulted in a significant loss of both high glucose and glucosamine responses. These results suggest that two cis-acting elements, the E-box and the GC-rich region, are involved at least partly in high glucose/glucosamine-stimulated transcription of the rat OPN gene.
Collapse
Affiliation(s)
- Sunao Asaumi
- Department of Clinical Cell Biology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Goldberg HJ, Whiteside CI, Fantus IG. The hexosamine pathway regulates the plasminogen activator inhibitor-1 gene promoter and Sp1 transcriptional activation through protein kinase C-beta I and -delta. J Biol Chem 2002; 277:33833-41. [PMID: 12105191 DOI: 10.1074/jbc.m112331200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Increased flux through the hexosamine biosynthesis pathway (HBP) has been shown to stimulate the expression of a number of genes. We previously demonstrated in glomerular mesangial and endothelial cells that both high glucose concentrations and glucosamine activated the plasminogen activator inhibitor-1 (PAI-1) gene promoter through the transcription factor, Sp1; and that the glutamine:fructose-6-phosphate amidotransferase inhibitor, 6-diazo-5-oxonorleucine, inhibited the effect of high glucose, but not that of glucosamine. Here, we examined the role of protein kinase C (PKC) isoforms in the regulation of the PAI-1 promoter and Sp1 transcriptional activity by the HBP. In transient transfections, exposure to 2 mm glucosamine or 20 mm glucose for 4 days increased the activities of a PAI-1 promoter-luciferase reporter gene as well as the Sp1 transcriptional activation domain fused to the GAL4 DNA-binding domain cotransfected with a GAL4 promoter-luciferase reporter. Cotransfected dominant negative PKC-betaI and -delta completely blocked the induction of PAI-1 promoter transcription by both sugars, whereas only dominant negative PKC-betaI interfered with Sp1-GAL4 activation. Both glucosamine and high glucose stimulated the in vitro kinase activity of immunoprecipitated PKC-betaI and -delta. Furthermore, 6-diazo-5-oxonorleucine suppressed high glucose-induced PKC kinase activity and Sp1-GAL4 transcriptional activation. These findings demonstrate a requirement for the PKC-betaI and -delta signal transduction pathways in HBP-induced transcription.
Collapse
Affiliation(s)
- Howard J Goldberg
- Department of Medicine, Mount Sinai Hospital and University Health Network, 600 University Avenue, Suite 780, Toronto, Ontario M5G 1X5, Canada
| | | | | |
Collapse
|
29
|
Mori S, Takemoto M, Yokote K, Asaumi S, Saito Y. Hyperglycemia-induced alteration of vascular smooth muscle phenotype. J Diabetes Complications 2002; 16:65-8. [PMID: 11872370 DOI: 10.1016/s1056-8727(01)00189-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We have previously reported that high glucose stimulates osteopontin (OPN) expression through protein kinase C-dependent pathway, as well as the hexosamine pathway, in cultured rat aortic smooth muscle cells (SMC). The finding prompted us to study in vivo expression of OPN in diabetes mellitus. In the present study, we found by immunohistochemistry that medial layers of the carotid arteries of streptozotocin (STZ)-induced diabetic rats, as well as the forearm arteries of diabetic patients, stained positive with OPN antibodies, whereas the staining of control rats, as well as nondiabetic patients, was negative. We also found that OPN stimulated migration and enhanced platelet-derived growth factor (PDGF)-mediated DNA synthesis of cultured rat aortic SMC. OPN and PDGF synergistically activated focal adhesion kinase (FAK), as well as extracellular signal-regulated kinase (ERK), which seems to be a reason for OPN-induced enhancement of PDGF-mediated DNA synthesis. Taken together, our present results raise a possibility that OPN plays a role in the development of diabetic vascular complications.
Collapse
Affiliation(s)
- Seijiro Mori
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, 260-0856, Chiba, Japan
| | | | | | | | | |
Collapse
|
30
|
Weber GF. The metastasis gene osteopontin: a candidate target for cancer therapy. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1552:61-85. [PMID: 11825687 DOI: 10.1016/s0304-419x(01)00037-3] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Malignant tumors are characterized by dysregulated growth control, overcoming of replicative senescence, and metastasis formation. Current therapeutic regimens mostly exert their effects through inhibition of cell cycle progression, leaving two major components of transformation untouched. The cytokine osteopontin is essential for the dissemination of various cancers. Past research has implied several modes in which osteopontin and its main receptors on tumor cells can be suppressed. Osteopontin expression is inhibitable on the levels of gene transcription and the RNA message, and the osteopontin protein can be blocked with antibodies or synthetic peptides. The osteopontin receptor CD44 has been targeted by diverse therapeutic strategies, including cytotoxic and immunotherapeutic approaches. The receptor integrin alpha(V)beta(3) contributes not only to tumor cell dissemination, but also to angiogenesis and osteolysis in bone metastases. Small molecule inhibitors of this receptor are under study as drug candidates. Because receptors and cytokine ligands that mediate metastasis formation are sparsely expressed in the adult healthy organism and are more readily reached by pharmaceuticals than intracellular drug targets they may represent a particularly suitable focus for therapeutic intervention.
Collapse
Affiliation(s)
- G F Weber
- Department of Radiation Oncology, New England Medical Center and Tufts University Medical School, 750 Washington Street, NEMC #824, Boston, MA 02111, USA.
| |
Collapse
|
31
|
Denhardt DT, Giachelli CM, Rittling SR. Role of osteopontin in cellular signaling and toxicant injury. Annu Rev Pharmacol Toxicol 2001; 41:723-49. [PMID: 11264474 DOI: 10.1146/annurev.pharmtox.41.1.723] [Citation(s) in RCA: 265] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Osteopontin (OPN) is a glycosylated phosphoprotein found in all body fluids and in the proteinaceous matrix of mineralized tissues. It can function both as a cell attachment protein and as a cytokine, delivering signals to cells via a number of receptors including several integrins and CD44. Expression of OPN is enhanced by a variety of toxicants, especially those that activate protein kinase C. In its capacity as a signaling molecule, OPN can modify gene expression and promote the migration of monocytes/macrophages up an OPN gradient. It has both inflammatory and anti-inflammatory actions. Some experiments suggest that it may inhibit apoptosis, possibly contributing to the survival of cells in response to toxicant injury. Elevated OPN expression often correlates with malignancy and has been shown to enhance the tumorigenic and/or metastatic phenotype of the cancer cell. Recent studies have revealed that OPN plays critical roles in bone remodeling and cell-mediated immunity.
Collapse
Affiliation(s)
- D T Denhardt
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA.
| | | | | |
Collapse
|
32
|
Sodhi CP, Phadke SA, Batlle D, Sahai A. Hypoxia stimulates osteopontin expression and proliferation of cultured vascular smooth muscle cells: potentiation by high glucose. Diabetes 2001; 50:1482-90. [PMID: 11375351 DOI: 10.2337/diabetes.50.6.1482] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We examined the effect of hypoxia on proliferation and osteopontin (OPN) expression in cultured rat aortic vascular smooth muscle (VSM) cells. In addition, we determined whether hypoxia-induced increases in OPN and cell proliferation are altered under hyperglycemic conditions. Quiescent cultures of VSM cells were exposed to hypoxia (3% O(2)) or normoxia (18% O(2)) in a serum-free medium, and cell proliferation as well as the expression of OPN was assessed. Cells exposed to hypoxia for 24 h exhibited a significant increase in [(3)H]thymidine incorporation followed by a significant increase in cell number at 48 h in comparison with respective normoxic controls. Exposure to hypoxia produced significant increases in OPN protein and mRNA expression at 2 h followed by a gradual decline at 6 and 12 h, with subsequent significant increases at 24 h. Neutralizing antibodies to either OPN or its receptor beta3 integrin but not neutralizing antibodies to beta5 integrin prevented the hypoxia-induced increase in [(3)H]thymidine incorporation. Inhibitors of protein kinase C (PKC) and p38 mitogen-activated protein (MAP) kinase also reduced the hypoxia-induced stimulation of proliferation and OPN synthesis. Exposure to high-glucose (HG) (25 mmol/l) medium under normoxic conditions also resulted in significant increases in OPN protein and mRNA levels as well as the proliferation of VSM cells. Under hypoxic conditions, HG further stimulated OPN synthesis and cell proliferation in an additive fashion. In conclusion, hypoxia-induced proliferation of cultured VSM cells is mediated by the stimulation of OPN synthesis involving PKC and p38 MAP kinase. In addition, hypoxia also enhances the effect of HG conditions on both OPN and proliferation of cultured VSM cells, which may have important implications in the development of diabetic atherosclerosis associated with arterial wall hypoxia.
Collapse
Affiliation(s)
- C P Sodhi
- Division of Nephrology and Hypertension, Northwestern University Medical School, 303 E. Chicago Ave., Chicago, IL 60611, USA
| | | | | | | |
Collapse
|
33
|
Akimoto Y, Kreppel LK, Hirano H, Hart GW. Hyperglycemia and the O-GlcNAc transferase in rat aortic smooth muscle cells: elevated expression and altered patterns of O-GlcNAcylation. Arch Biochem Biophys 2001; 389:166-75. [PMID: 11339805 DOI: 10.1006/abbi.2001.2331] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hyperglycemia leads to vascular disease specific to diabetes mellitus. This pathology, which results from abnormal proliferation of smooth muscle cells in arterial walls, may lead to cataract, renal failure, and atherosclerosis. The hexosamine biosynthetic pathway is exquisitely responsive to glucose concentration and plays an important role in glucose-induced insulin resistance. UDP-GlcNAc: polypeptide O-N-acetylglucosaminyltransferase (O-GlcNAc transferase; OGTase) catalyzes the O-linked attachment of single GlcNAc moieties to serine and threonine residues on many cytosolic or nuclear proteins. Polyclonal antibody against OGTase was used to examine the expression of OGTase in rat aorta and aortic smooth muscle (RASM) cells. OGTase enzymatic activity and expression at the mRNA and protein levels were determined in RASM cells cultured at normal (5 mM) and at high (20 mM) glucose concentrations. OGTase mRNA and protein are expressed in both endothelial cells and smooth muscle cells in the aorta of normal rats. In both cell types, the nucleus is intensely stained, while the cytoplasm stains diffusely. Immunoelectron microscopy shows that OGTase is localized to euchromatin and around the myofilaments of smooth muscle cells. In RASM cells grown in 5 mM glucose, OGTase is also located mainly in the nucleus. Hyperglycemic RASM cells also display a relative increase in OGTase's p78 subunit and an overall increase protein and activity for OGTase. Biochemical analyses show that hyperglycemia qualitatively and quantitatively alters the glycosylation or expression of many O-GlcNAc-modified proteins in the nucleus. These results suggest that the abnormal O-GlcNAc modification of intracellular proteins may be involved in glucose toxicity to vascular tissues.
Collapse
Affiliation(s)
- Y Akimoto
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Alabama at Birmingham Station, Alabama 35294, USA.
| | | | | | | |
Collapse
|
34
|
Takemoto M, Kitahara M, Yokote K, Asaumi S, Take A, Saito Y, Mori S. NK-104, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, reduces osteopontin expression by rat aortic smooth muscle cells. Br J Pharmacol 2001; 133:83-8. [PMID: 11325797 PMCID: PMC1572762 DOI: 10.1038/sj.bjp.0704046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2000] [Revised: 02/19/2001] [Accepted: 02/19/2001] [Indexed: 11/09/2022] Open
Abstract
1. It has been suggested that osteopontin promotes the development of atherosclerosis, especially under diabetic conditions. 2. In the present study, we found that NK-104, a new potent synthetic inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, reduced osteopontin expression both at protein and mRNA levels in cultured rat aortic smooth muscle cells. 3. The inhibitory effect of NK-104 was almost completely reversed by mevalonate, suggesting that mevalonate or its metabolites play important roles in the regulation of osteopontin expression. 4. Furthermore, oral administration of NK-104 (3 mg kg(-1) day(-1) for 7 days) effectively suppressed abnormally upregulated expression of osteopontin mRNA in the aorta and kidney of streptozotocin-induced diabetic rats. 5. These data support a notion that NK-104 is a suitable drug for the treatment of diabetic patients with hypercholesterolaemia.
Collapse
MESH Headings
- Administration, Oral
- Animals
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Blotting, Western
- Cells, Cultured
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Gene Expression Regulation/drug effects
- Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology
- Kidney/drug effects
- Kidney/metabolism
- Male
- Mevalonic Acid/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Osteopontin
- Quinolines/administration & dosage
- Quinolines/antagonists & inhibitors
- Quinolines/pharmacology
- Quinolines/therapeutic use
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Sialoglycoproteins/biosynthesis
- Sialoglycoproteins/genetics
Collapse
Affiliation(s)
- Minoru Takemoto
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-0856, Japan
| | - Masaki Kitahara
- Shiraoka Research Station of Biological Science, Nissan Chemical Industries, Ltd., 1470 Shiraoka, Shiraoka-Machi, Minamisaitama, Saitama 349-0294, Japan
| | - Koutaro Yokote
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-0856, Japan
| | - Sunao Asaumi
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-0856, Japan
| | - Ayako Take
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-0856, Japan
| | - Yasushi Saito
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-0856, Japan
| | - Seijiro Mori
- Second Department of Internal Medicine, School of Medicine, Chiba University, 1-8-1 Inohana, Chiba 260-0856, Japan
| |
Collapse
|
35
|
Sodhi CP, Phadke SA, Batlle D, Sahai A. Hypoxia and high glucose cause exaggerated mesangial cell growth and collagen synthesis: role of osteopontin. Am J Physiol Renal Physiol 2001; 280:F667-74. [PMID: 11249858 DOI: 10.1152/ajprenal.2001.280.4.f667] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The effect of hypoxia on the proliferation and collagen synthesis of cultured rat mesangial cells was examined under normal-glucose (NG, 5 mM) and high-glucose (HG, 25 mM)-media conditions. In addition, a role for osteopontin (OPN) in mediating these processes was assessed. Quiescent cultures were exposed to hypoxia (3% O(2)) and normoxia (18% O(2)) in a serum-free medium with NG or HG, and cell proliferation, collagen synthesis, and OPN expression were assessed. Cells exposed to hypoxia in NG medium resulted in significant increases in [(3)H]thymidine incorporation, cell number, and [(3)H]proline incorporation, respectively. HG incubations also produced significant stimulation of these parameters under normoxic conditions, which were markedly enhanced in cells exposed to hypoxia in HG medium. In addition, hypoxia and HG stimulated the mRNA levels of type IV collagen, and the combination of hypoxia and HG resulted in additive increases in type IV collagen expression. Hypoxia and HG also stimulated OPN mRNA and protein levels in an additive fashion. A neutralizing antibody to OPN or its beta(3)-integrin receptor significantly blocked the effect of hypoxia and HG on proliferation and collagen synthesis. In conclusion, these results demonstrate for the first time that hypoxia in HG medium produces exaggerated mesangial cell growth and type IV collagen synthesis. In addition, OPN appears to play a role in mediating the accelerated mesangial cell growth and collagen synthesis found in a hyperglycemic and hypoxic environment.
Collapse
Affiliation(s)
- C P Sodhi
- Division of Nephrology and Hypertension, Northwestern University Medical School, Chicago, Illinois 60611, USA
| | | | | | | |
Collapse
|
36
|
Hasty AH, Shimano H, Yahagi N, Amemiya-Kudo M, Perrey S, Yoshikawa T, Osuga J, Okazaki H, Tamura Y, Iizuka Y, Shionoiri F, Ohashi K, Harada K, Gotoda T, Nagai R, Ishibashi S, Yamada N. Sterol regulatory element-binding protein-1 is regulated by glucose at the transcriptional level. J Biol Chem 2000; 275:31069-77. [PMID: 10913129 DOI: 10.1074/jbc.m003335200] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In vivo studies suggest that sterol regulatory element-binding protein (SREBP)-1 plays a key role in the up-regulation of lipogenic genes in the livers of animals that have consumed excess amounts of carbohydrates. In light of this, we sought to use an established mouse hepatocyte cell line, H2-35, to further define the mechanism by which glucose regulates nuclear SREBP-1 levels. First, we show that these cells transcribe high levels of SREBP-1c that are increased 4-fold upon differentiation from a prehepatocyte to a hepatocyte phenotype, making them an ideal cell culture model for the study of SREBP-1c induction. Second, we demonstrate that the presence of precursor and mature forms of SREBP-1 protein are positively regulated by medium glucose concentrations ranging from 5. 5 to 25 mm and are also regulated by insulin, with the amount of insulin in the fetal bovine serum being sufficient for maximal stimulation of SREBP-1 expression. Third, we show that the increase in SREBP-1 protein is due to an increase in SREBP-1 mRNA. Reporter gene analysis of the SREBP-1c promoter demonstrated a glucose-dependent induction of transcription. In contrast, expression of a fixed amount of the precursor form of SREBP-1c protein showed that glucose does not influence its cleavage. Fourth, we demonstrate that the glucose induction of SREBP could not be reproduced by fructose, xylose, or galactose nor by glucose analogs 2-deoxy glucose and 3-O-methyl glucopyranose. These data provide strong evidence for the induction of SREBP-1c mRNA by glucose leading to increased mature protein in the nucleus, thus providing a potential mechanism for the up-regulation of lipogenic genes by glucose in vivo.
Collapse
Affiliation(s)
- A H Hasty
- Department of Metabolic Diseasese, University of Tokyo, Tokyo 113-8655, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Takemoto M, Yokote K, Nishimura M, Shigematsu T, Hasegawa T, Kon S, Uede T, Matsumoto T, Saito Y, Mori S. Enhanced expression of osteopontin in human diabetic artery and analysis of its functional role in accelerated atherogenesis. Arterioscler Thromb Vasc Biol 2000; 20:624-8. [PMID: 10712383 DOI: 10.1161/01.atv.20.3.624] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have previously reported that high glucose stimulates osteopontin (OPN) expression through protein kinase C-dependent pathways as well as hexosamine pathways in cultured rat aortic smooth muscle cells. The finding prompted us to study in vivo expression of OPN in diabetes mellitus. In the present study, we found by immunohistochemistry that medial layers of the carotid arteries of streptozotocin-induced diabetic rats and the forearm arteries of diabetic patients stained positively for OPN antibodies, whereas the staining from arteries of control rats and nondiabetic patients was negative. We also found that OPN stimulated the migration and enhanced platelet-derived growth factor (PDGF)-mediated DNA synthesis of cultured rat aortic smooth muscle cells. OPN and PDGF synergistically activated focal adhesion kinase as well as extracellular signal-regulated kinase; this finding seems to explain the OPN-induced enhancement of PDGF-mediated DNA synthesis. Taken together, our present results raise a possibility that OPN plays a role in the development of diabetic vascular complications.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Animals
- Aorta/cytology
- Aorta/enzymology
- Arteriosclerosis/etiology
- Arteriosclerosis/metabolism
- Becaplermin
- Carotid Arteries/metabolism
- Cell Movement/drug effects
- Cell Movement/physiology
- Cells, Cultured
- DNA/biosynthesis
- DNA-Binding Proteins
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 2/metabolism
- Diabetic Angiopathies/metabolism
- Enzyme Activation/drug effects
- Female
- Focal Adhesion Kinase 1
- Focal Adhesion Protein-Tyrosine Kinases
- Forearm/blood supply
- Humans
- Male
- Microcirculation/physiology
- Middle Aged
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/enzymology
- Osteopontin
- Platelet-Derived Growth Factor/pharmacology
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-sis
- Rats
- Rats, Wistar
- Sialoglycoproteins/biosynthesis
- Sialoglycoproteins/pharmacology
- Transcription Factors
- ets-Domain Protein Elk-1
Collapse
Affiliation(s)
- M Takemoto
- Second Department of Internal Medicine, School of Medicine, Chiba University, Chiba, Japan.
| | | | | | | | | | | | | | | | | | | |
Collapse
|