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Zager RA, Johnson ACM. Early loss of glutathione -s- transferase (GST) activity during diverse forms of acute renal tubular injury. Physiol Rep 2022; 10:e15352. [PMID: 35748049 PMCID: PMC9226817 DOI: 10.14814/phy2.15352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/22/2022] [Accepted: 05/23/2022] [Indexed: 02/07/2023] Open
Abstract
Glutathione‐S‐transferases (GSTs) are a diverse group of phase II detoxification enzymes which primarily evoke tissue protection via glutathione conjugation to xenobiotics and reactive oxygen species. Given their cytoprotective properties, potential changes in GST expression during AKI has pathophysiologic relevance. Hence, we evaluated total GST activity, and the mRNA responses of nine cytosolic GST isotypes (GST alpha1, kappa1, mu1/5, omega1, pi1 sigma1, theta1, zeta1 mRNAs), in five diverse mouse models of AKI (glycerol, ischemia/reperfusion; maleate, cisplatin, endotoxemia). Excepting endotoxemia, each AKI model significantly reduced GST activity (~35%) during both the AKI “initiation” (0‐4 h) and “maintenance” phases (18 or 72 h). During the AKI maintenance phase, increases in multiple GST mRNAs were observed. However, no improvement in GST activity resulted. Increased urinary GST excretion followed AKI induction. However, this could not explain the reduced renal GST activity given that it also fell in response to ex vivo renal ischemia (i.e., absent urinary excretion). GST alpha, a dominant proximal tubule GST isotype, manifested 5–10‐fold protein increases following AKI, arguing against GST proteolysis as the reason for the GST activity declines. Free fatty acids (FFAs) and lysophospholipids, which markedly accumulate during AKI, are known to bind to, and suppress, GST activity. Supporting this concept, arachidonic acid addition to renal cortical protein extracts caused rapid GST activity reductions. Based on these results, we conclude that diverse forms of AKI significantly reduce GST activity. This occurs despite increased GST transcription/translation and independent of urinary GST excretion. Injury‐induced generation of endogenous GST inhibitors, such as FFAs, appears to be a dominant cause.
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Reddiar SB, Jin L, Wai DCC, Csoti A, Panyi G, Norton RS, Nicolazzo JA. Lipopolysaccharide influences the plasma and brain pharmacokinetics of subcutaneously-administered HsTX1[R14A], a K V1.3-blocking peptide. Toxicon 2021; 195:29-36. [PMID: 33689790 DOI: 10.1016/j.toxicon.2021.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 12/01/2022]
Abstract
KV1.3 is a voltage-gated potassium channel that is upregulated in neuroinflammatory conditions, such as Alzheimer's disease and Parkinson's disease. HsTX1[R14A] is a potent and selective peptide blocker of KV1.3 with the potential to block microglial KV1.3, but its brain uptake is expected to be limited owing to the restrictive nature of the blood-brain barrier. To assess its peripheral and brain exposure, a LC-MS/MS assay was developed to quantify HsTX1[R14A] concentrations in mouse plasma and brain homogenate that was reliable and reproducible in the range of 6.7-66.7 nM (r2 = 0.9765) and 15-150 pmol/g (r2 = 0.9984), respectively. To assess if neuroinflammation affected HsTX1[R14A] disposition, C57BL/6 mice were administered HsTX1[R14A] subcutaneously (2 mg/kg) 24 h after an intraperitoneal dose of Escherichia coli lipopolysaccharide (LPS), which is commonly used to induce neuroinflammation; brain and plasma concentrations of HsTX1[R14A] were then quantified over 120 min. LPS treatment significantly retarded the decline in HsTX1[R14A] plasma concentrations, presumably as a result of reducing renal clearance, and led to substantial brain uptake of HsTX1[R14A], presumably through disruption of brain inter-endothelial tight junctions. This study suggests that HsTX1[R14A] may reach microglia in sufficient concentrations to block KV1.3 in neuroinflammatory conditions, and therefore has the potential to reduce neurodegenerative diseases.
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Affiliation(s)
- Sanjeevini Babu Reddiar
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Liang Jin
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Dorothy C C Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Agota Csoti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Hungary
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Hungary
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, Victoria, Australia
| | - Joseph A Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
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Arai H, Takahashi R, Sakamoto Y, Kitano T, Mashita O, Hara S, Yoshikawa S, Kawasaki K, Ichinose H. Peripheral tetrahydrobiopterin is involved in the pathogenesis of mechanical hypersensitivity in a rodent postsurgical pain model. Pain 2020; 161:2520-2531. [PMID: 32541389 DOI: 10.1097/j.pain.0000000000001946] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Because treatment for postsurgical pain (PSP) remains a major unmet medical need, the emergence of safe and innovative nonopioid drugs has been strongly coveted. Tetrahydrobiopterin (BH4) is an interesting molecule for gaining a better understanding the pathological mechanism of neuropathic pain. However, whether BH4 and its pathway are involved in the pathogenesis of PSP remains unclear. In this study, we found that early in a rat paw incision model, the gene expression of GTP cyclohydrolase 1 (GTPCH) and sepiapterin reductase (SPR), BH4-producing enzymes in the de novo pathway, were significantly increased in incised compared with naive paw skin. Although a significant increase in GTPCH protein levels was observed in incised paw skin until only 1 day after incision, a significant increase in BH4 levels was observed until 7 days after incision. In vivo, Spr-knockout mice showed an antinociceptive phenotype in the hind paw incision compared with the wild-type and Spr heterozygote groups. Furthermore, QM385, the SPR inhibitor, showed a significant dose-dependent, antinociceptive effect, which was supported by a reduction in BH4 levels in incised skin tissues, with no apparent adverse effects. Immunohistochemical analysis demonstrated that macrophages expressing GTPCH protein were increased around the injury site in the rat paw incision model. These results indicate that BH4 is involved in the pathogenesis of PSP, and that inhibition of the BH4 pathway could provide a new strategy for the treatment of acute PSP.
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Affiliation(s)
- Hirokazu Arai
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
- Laboratory for Pharmacology, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Rina Takahashi
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yoshiaki Sakamoto
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Tatsuya Kitano
- Laboratory for Pharmacology, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Okishi Mashita
- Laboratory for Safety Assessment and ADME, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Satoshi Hara
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Satoru Yoshikawa
- Laboratory for Pharmacology, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Koh Kawasaki
- Laboratory for Pharmacology, Pharmaceuticals Research Center, Asahi Kasei Pharma Corporation, Shizuoka, Japan
| | - Hiroshi Ichinose
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
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Wang H, Zhang C, Chen H, Gu Z, Zhao J, Zhang H, Chen YQ, Chen W. Tetrahydrobiopterin Plays a Functionally Significant Role in Lipogenesis in the Oleaginous Fungus Mortierella alpina. Front Microbiol 2020; 11:250. [PMID: 32153536 PMCID: PMC7044132 DOI: 10.3389/fmicb.2020.00250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/03/2020] [Indexed: 11/13/2022] Open
Abstract
Tetrahydrobiopterin (BH4) is well-known as a cofactor of phenylalanine hydroxylase (PAH) and nitric oxide synthase (NOS), but its exact role in lipogenesis is unclear. In this study, the GTP cyclohydrolase I (GTPCH) gene was overexpressed to investigate the role of BH4 in lipogenesis in oleaginous fungus Mortierella alpina. Transcriptome data analysis reveal that GTPCH expression was upregulated when nitrogen was exhausted, resulting in lipid accumulation. Significant changes were also found in the fatty acid profile of M. alpina grown on medium that contained a GTPCH inhibitor relative to that of M. alpina grown on medium that lacked the inhibitor. GTPCH overexpression in M. alpina (the MA-GTPCH strain) led to a sevenfold increase in BH4 levels and enhanced cell fatty acid synthesis and poly-unsaturation. Increased levels of nicotinamide adenine dinucleotide phosphate (NADPH) and upregulated expression of NADPH-producing genes in response to enhanced BH4 levels were also observed, which indicate a novel aspect of the NADPH regulatory mechanism. Increased BH4 levels also enhanced phenylalanine hydroxylation and nitric oxide synthesis, and the addition of an NOS or a PAH inhibitor in the MA-GTPCH and control strain cultures decreased fatty acid accumulation, NADPH production, and the transcript levels of NADPH-producing genes. Our research suggests an important role of BH4 in lipogenesis and that the phenylalanine catabolism and arginine-nitric oxide pathways play an integrating role in translating the effects of BH4 on lipogenesis by regulating the cellular NADPH pool. Thus, our findings provide novel insights into the mechanisms of efficient lipid biosynthesis regulation in oleaginous microorganisms and lay a foundation for the genetic engineering of these organisms to optimize their dietary fat yield.
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Affiliation(s)
- Hongchao Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Chen Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Haiqin Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Zhennan Gu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China
| | - Yong Q Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China
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Li Y, Deng SL, Lian ZX, Yu K. Roles of Toll-Like Receptors in Nitroxidative Stress in Mammals. Cells 2019; 8:cells8060576. [PMID: 31212769 PMCID: PMC6627996 DOI: 10.3390/cells8060576] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/08/2019] [Accepted: 06/10/2019] [Indexed: 01/20/2023] Open
Abstract
Free radicals are important antimicrobial effectors that cause damage to DNA, membrane lipids, and proteins. Professional phagocytes produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) that contribute towards the destruction of pathogens. Toll-like receptors (TLRs) play a fundamental role in the innate immune response and respond to conserved microbial products and endogenous molecules resulting from cellular damage to elicit an effective defense against invading pathogens, tissue injury, or cancer. In recent years, several studies have focused on how the TLR-mediated activation of innate immune cells leads to the production of pro-inflammatory factors upon pathogen invasion. Here, we review recent findings that indicate that TLRs trigger a signaling cascade that induces the production of reactive oxygen and nitrogen species.
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Affiliation(s)
- Yao Li
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
| | - Shou-Long Deng
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Zheng-Xing Lian
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
| | - Kun Yu
- Beijing Key Laboratory for Animal Genetic Improvement, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics and Breeding of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
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Youn CK, Cho SI, Lee MY, Jeon YJ, Lee SK. Inhibition of ERK1/2 by silymarin in mouse mesangial cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 21:117-124. [PMID: 28066148 PMCID: PMC5214903 DOI: 10.4196/kjpp.2017.21.1.117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 01/31/2023]
Abstract
The present study aimed to show that pro-inflammatory cytokines [tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-1β] synergistically induce the production of nitric oxide (NO) production in mouse mesangial cells, which play an important role in inflammatory glomerular injury. We also found that co-treatment with cytokines at low doses (TNF-α; 5 ng/ml, IFN-γ; 5 ng/ml, and IL-1β; 1.25 U/ml) synergistically induced NO production, whereas treatment with each cytokine alone did not increase NO production at doses up to 100 ng/ml or 50 U/ml. Silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), attenuates cytokine mixture (TNF-α, IFN-γ, and IL-1β)-induced NO production. Western blot and RT-PCR analyses showed that silymarin inhibits inducible nitric oxide synthase (iNOS) expression in a dose-dependent manner. Silymarin also inhibited extracellular signal-regulated protein kinase-1 and -2 (ERK1/2) phosphorylation. Collectively, we have demonstrated that silymarin inhibits NO production in mouse mesangial cells, and may act as a useful anti-inflammatory agent.
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Affiliation(s)
- Cha Kyung Youn
- Department of Premedical Sciences, Chosun University College of Medicine, Gwangju 61452, Korea
| | - Sung Il Cho
- Department of Otolaryngology-Head and Neck Surgery, Chosun University College of Medicine, Gwangju 61452, Korea
| | - Min Young Lee
- Department of Pharmacology, Chosun University College of Medicine, Gwangju 61452, Korea
| | - Young Jin Jeon
- Department of Pharmacology, Chosun University College of Medicine, Gwangju 61452, Korea
| | - Seog Ki Lee
- Department of Thoracic and Cardiovascular Surgery, Chosun University College of Medicine, Gwangju 61452, Korea
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Toll-Like Receptor 4 Promotes NO Synthesis by Upregulating GCHI Expression under Oxidative Stress Conditions in Sheep Monocytes/Macrophages. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:359315. [PMID: 26576220 PMCID: PMC4630417 DOI: 10.1155/2015/359315] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 02/26/2015] [Indexed: 12/14/2022]
Abstract
Many groups of Gram-negative bacteria cause diseases that are harmful to sheep. Toll-like receptor 4 (TLR4), which is critical for detecting Gram-negative bacteria by the innate immune system, is activated by lipopolysaccharide (LPS) to initiate inflammatory responses and oxidative stress. Oxidation intermediates are essential activators of oxidative stress, as low levels of free radicals form a stressful oxidative environment that can clear invading pathogens. NO is an oxidation intermediate and its generation is regulated by nitric oxide synthase (iNOS). Guanosine triphosphate cyclohydrolase (GCHI) is the rate-limiting enzyme for tetrahydrobiopterin (BH4) synthesis, which is essential for the production of inducible iNOS. Previously, we made vectors to overexpress the sheep TLR4 gene. Herein, first generation (G1) of transgenic sheep was stimulated with LPS in vivo and in vitro, and oxidative stress and GCHI expression were investigated. Oxidative injury caused by TLR4 overexpression was tightly regulated in tissues. However, the transgenic (Tg) group still secreted nitric oxide (NO) when an iNOS inhibitor was added. Furthermore, GCHI expression remained upregulated in both serum and monocytes/macrophages. Thus, overexpression of TLR4 in transgenic sheep might accelerate the clearance of invading microbes through NO generation following LPS stimulation. Additionally, TLR4 overexpression also enhances GCHI activation.
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Bhargava R, Altmann CJ, Andres-Hernando A, Webb RG, Okamura K, Yang Y, Falk S, Schmidt EP, Faubel S. Acute lung injury and acute kidney injury are established by four hours in experimental sepsis and are improved with pre, but not post, sepsis administration of TNF-α antibodies. PLoS One 2013; 8:e79037. [PMID: 24265742 PMCID: PMC3827109 DOI: 10.1371/journal.pone.0079037] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 09/26/2013] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Acute kidney injury (AKI) and acute lung injury (ALI) are serious complications of sepsis. AKI is often viewed as a late complication of sepsis. Notably, the onset of AKI relative to ALI is unclear as routine measures of kidney function (BUN and creatinine) are insensitive and increase late. In this study, we hypothesized that AKI and ALI would occur simultaneously due to a shared pathophysiology (i.e., TNF-α mediated systemic inflammatory response syndrome [SIRS]), but that sensitive markers of kidney function would be required to identify AKI. METHODS Sepsis was induced in adult male C57B/6 mice with 5 different one time doses of intraperitoneal (IP) endotoxin (LPS) (0.00001, 0.0001, 0.001, 0.01, or 0.25 mg) or cecal ligation and puncture (CLP). SIRS was assessed by serum proinflammatory cytokines (TNF-α, IL-1β, CXCL1, IL-6), ALI was assessed by lung inflammation (lung myeloperoxidase [MPO] activity), and AKI was assessed by serum creatinine, BUN, and glomerular filtration rate (GFR) (by FITC-labeled inulin clearance) at 4 hours. 20 µgs of TNF-α antibody (Ab) or vehicle were injected IP 2 hours before or 2 hours after IP LPS. RESULTS Serum cytokines increased with all 5 doses of LPS; AKI and ALI were detected within 4 hours of IP LPS or CLP, using sensitive markers of GFR and lung inflammation, respectively. Notably, creatinine did not increase with any dose; BUN increased with 0.01 and 0.25 mg. Remarkably, GFR was reduced 50% in the 0.001 mg LPS dose, demonstrating that dramatic loss of kidney function can occur in sepsis without a change in BUN or creatinine. Prophylactic TNF-α Ab reduced serum cytokines, lung MPO activity, and BUN; however, post-sepsis administration had no effect. CONCLUSIONS ALI and AKI occur together early in the course of sepsis and TNF-α plays a role in the early pathogenesis of both.
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Affiliation(s)
- Rhea Bhargava
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Christopher J. Altmann
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Ana Andres-Hernando
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Ryan G. Webb
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Kayo Okamura
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Yimu Yang
- Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine, Aurora, Colorado, United States of America
| | - Sandor Falk
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
| | - Eric P. Schmidt
- Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine, Aurora, Colorado, United States of America
| | - Sarah Faubel
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, Colorado, United States of America
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Impact of lipopolysaccharide-induced inflammation on the disposition of the aminocephalosporin cefadroxil. Antimicrob Agents Chemother 2013; 57:6171-8. [PMID: 24080658 DOI: 10.1128/aac.01497-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The purpose of this study was to determine if the disposition of cefadroxil, an α-amino-containing β-lactam antibiotic, changes during lipopolysaccharide (LPS)-induced acute inflammation. Six hours after LPS or saline treatment, mice received 1 nmol/g cefadroxil intravenously along with inulin for glomerular filtration rate (GFR) determination. Serial blood samples, along with tissue and urine samples, were collected at predetermined time points. In order to determine inflammation-induced changes in GFR, renal tubular secretion, and reabsorption, it was necessary to coadminister 70 mg/kg probenecid. Changes in the expression of the mRNA of transporters involved in cefadroxil disposition in the kidneys and choroid plexus were also investigated 6 h after LPS treatment. The results demonstrated marked increases in blood, cerebrospinal fluid, and tissue cefadroxil concentrations with LPS treatment. Tissue-to-blood concentration ratios were decreased by 4.6-fold in the choroid plexus and by 2.5-fold in the kidneys during LPS-induced inflammation. Renal, but not choroid plexus, mRNA expression of peptide transporter 2, organic-anion transporter 1 (OAT1), OAT3, and multidrug resistance-associated protein 4 was mildly reduced in LPS-treated mice. The renal clearance of cefadroxil was substantially decreased by LPS treatment (3-fold). GFR was also reduced by 3-fold in LPS-treated mice, but no significant differences in the fractional reabsorption of cefadroxil and renal secretion once normalized by GFR were observed. These findings demonstrated that LPS-induced inflammation has a dramatic effect on the renal excretion of cefadroxil. It appears that changes in transporter expression played a minor role during LPS treatment but that renal dysfunction, associated with GFR reduction, was responsible for the substantial increase in plasma cefadroxil concentration-time profiles.
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Peng YL, Liu YN, Liu L, Wang X, Jiang CL, Wang YX. Inducible nitric oxide synthase is involved in the modulation of depressive behaviors induced by unpredictable chronic mild stress. J Neuroinflammation 2012; 9:75. [PMID: 22531370 PMCID: PMC3390904 DOI: 10.1186/1742-2094-9-75] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 04/25/2012] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Experiences and inflammatory mediators are fundamental in the provocation of major depressive disorders (MDDs). We investigated the roles and mechanisms of inducible nitric oxide synthase (iNOS) in stress-induced depression. METHODS We used a depressive-like state mouse model induced by unpredictable chronic mild stress (UCMS). Depressive-like behaviors were evaluated after 4 weeks of UCMS, in the presence and absence of the iNOS inhibitor N-(3-(aminomethyl)benzyl)acetamidine (1400 W) compared with the control group. Immunohistochemistry was used to check the loss of Nissl bodies in cerebral cortex neurons. The levels of iNOS mRNA expression in the cortex and nitrites in the plasma were measured with real-time reverse transcription PCR (RT-PCR) and Griess reagent respectively. RESULTS Results showed that the 4-week UCMS significantly induced depressive-like behaviors, including decreased sucrose preference in a sucrose preference test, increased duration of immobility in a forced swim test, and decreased hole-searching time in a locomotor activity test. Meanwhile, in the locomotor activity test, UCMS had no effect on normal locomotor activities, such as resting time, active time and total travel distance. Furthermore, the levels of iNOS mRNA expression in the cortex and nitrites in the plasma of UCMS-exposed mice were significantly increased compared with that of the control group. Neurons of cerebral cortex in UCMS-exposed mice were shrunken with dark staining, together with loss of Nissl bodies. The above-mentioned stress-related depressive-like behaviors, increase of iNOS mRNA expression in the cortex and nitrites in the plasma, and neuron damage, could be abrogated remarkably by pretreating the mice with an iNOS inhibitor (1400 W). Moreover, neurons with abundant Nissl bodies were significantly increased in the 1400 W + UCMS group. CONCLUSIONS These results support the notion that stress-related NO (derived from iNOS) may contribute to depressive-like behaviors in a mouse model, potentially concurrent with neurodegenerative effects within the cerebral cortex.
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Affiliation(s)
- Yun-Li Peng
- Department of Nautical Medicine, Second Military Medical University, Shanghai, P R China
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11
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Heemskerk S, Masereeuw R, Russel FGM, Pickkers P. Selective iNOS inhibition for the treatment of sepsis-induced acute kidney injury. Nat Rev Nephrol 2009; 5:629-40. [PMID: 19786992 DOI: 10.1038/nrneph.2009.155] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The incidence and mortality of sepsis and the associated development of acute kidney injury (AKI) remain high, despite intense research into potential treatments. Targeting the inflammatory response and/or sepsis-induced alterations in the (micro)circulation are two therapeutic strategies. Another approach could involve modulating the downstream mechanisms that are responsible for organ system dysfunction. Activation of inducible nitric oxide (NO) synthase (iNOS) during sepsis leads to elevated NO levels that influence renal hemodynamics and cause peroxynitrite-related tubular injury through the local generation of reactive nitrogen species. In many organs iNOS is not constitutively expressed; however, it is constitutively expressed in the kidney and, in humans, a relationship between the upregulation of renal iNOS and proximal tubular injury during systemic inflammation has been demonstrated. For these reasons, the selective inhibition of renal iNOS might have important implications for the treatment of sepsis-induced AKI. Various animal studies have demonstrated that selective iNOS inhibition-in contrast to nonselective NOS inhibition-attenuates sepsis-induced renal dysfunction and improves survival, a finding that warrants investigation in clinical trials. In this Review, the selective inhibition of iNOS as a potential novel treatment for sepsis-induced AKI is discussed.
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Affiliation(s)
- Suzanne Heemskerk
- Department of Intensive Care Medicine and the Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
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Du J, Wei N, Guan T, Xu H, An J, Pritchard KA, Shi Y. Inhibition of CDKS by roscovitine suppressed LPS-induced *NO production through inhibiting NFkappaB activation and BH4 biosynthesis in macrophages. Am J Physiol Cell Physiol 2009; 297:C742-9. [PMID: 19553566 PMCID: PMC2740392 DOI: 10.1152/ajpcell.00138.2009] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 06/23/2009] [Indexed: 11/22/2022]
Abstract
In inflammatory diseases, tissue damage is critically associated with nitric oxide ((*)NO) and cytokines, which are overproduced in response to cellular release of endotoxins. Here we investigated the inhibitory effect of roscovitine, a selective inhibitor of cyclin-dependent kinases (CDKs) on (*)NO production in mouse macrophages. In RAW264.7 cells, we found that roscovitine abolished the production of (*)NO induced by lipopolysaccharide (LPS). Moreover, roscovitine significantly inhibited LPS-induced inducible nitric oxide synthase (iNOS) mRNA and protein expression. Our data also showed that roscovitine attenuated LPS-induced phosphorylation of IkappaB kinase beta (IKKbeta), IkappaB, and p65 but enhanced the phosphorylation of ERK, p38, and c-Jun NH(2)-terminal kinase (JNK). In addition, roscovitine dose dependently inhibited LPS-induced expression of cyclooxygenase-2 (COX)-2, IL-1beta, and IL-6 but not tumor necrosis factor (TNF)-alpha. Tetrahydrobiopterin (BH(4)), an essential cofactor for iNOS, is easily oxidized to 7,8-dihydrobiopterin (BH(2)). Roscovitine significantly inhibited LPS-induced BH(4) biosynthesis and decreased BH(4)-to-BH(2) ratio. Furthermore, roscovitine greatly reduced the upregulation of GTP cyclohydrolase-1 (GCH-1), the rate-limiting enzyme for BH(4) biosynthesis. Using other CDK inhibitors, we found that CDK1, CDK5, and CDK7, but not CDK2, significantly inhibited LPS-induced (*)NO production in macrophages. Similarly, in isolated peritoneal macrophages, roscovitine strongly inhibited (*)NO production, iNOS, and COX-2 upregulation, activation of NFkappaB, and induction of GCH-1 by LPS. Together, our data indicate that roscovitine abolishes LPS-induced (*)NO production in macrophages by suppressing nuclear factor-kappaB activation and BH(4) biosynthesis, which might be mediated by CDK1, CDK5, and CDK7. Our results also suggest that roscovitine may inhibit inflammation and that CDKs may play important roles in the mechanisms by which roscovitine attenuates inflammation.
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Affiliation(s)
- Jianhai Du
- Division of Pediatric Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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Groeneveld ABJ, Vervloet MG. Treatment of septic renal injury by alkaline phosphatase: An emperor with new clothes*. Crit Care Med 2009; 37:740-1. [DOI: 10.1097/ccm.0b013e318194c12c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Many of the studies of acute renal injury have been conducted in young mice usually during their rapid growth phase; yet, the impact of age or growth stage on the degree of injury is unknown. To address this issue, we studied three forms of injury (endotoxemic-, glycerol-, and maleate-induced) in mice ranging in age from adolescence (3 weeks) to maturity (16 weeks). The severity of injury within each model significantly correlated with weight and age. We also noticed a progressive age-dependent reduction in renal cholesterol content, a potential injury modifier. As the animals grew and aged they also exhibited stepwise decrements in the mRNAs of HMG CoA reductase and the low density lipoprotein receptor, two key cholesterol homeostatic genes. This was paralleled by decreased amounts of RNA polymerase II and the transcription factor SREBP1/2 at the reductase and lipoprotein receptor gene loci as measured by chromatin immunoprecipitation. Our study shows that the early phase of mouse growth can profoundly alter renal susceptibility to diverse forms of experimental acute renal injury.
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