Danaparoid sodium reduces ischemia/reperfusion-induced liver injury in rats by attenuating inflammatory responses

2007 ◽  
Vol 97 (01) ◽  
pp. 81-87 ◽  
Author(s):  
Naoaki Harada ◽  
Hidefumi Kohmura ◽  
Mitsuhiro Uchiba ◽  
Tsutomu Tomita ◽  
Kenji Okajima

SummaryThis study was undertaken to examine the mechanism by which danaparoid sodium (DS), a heparinoid that contains mainly heparan sulfate, prevents reperfusion-induced hepatic damage in a rat model of ischemia/reperfusion (I/R)-induced liver injury. Administration of DS significantly reduced liver injury and inhibited the decrease in hepatic tissue blood flow in rats. DS attenuated hepatic I/R-induced increases in hepatic tissue levels of tumor necrosis factor (TNF) and myeloperoxidase (MPO) in vivo. In contrast, neither monocytic TNF production nor neutrophil activation was inhibited by DS in vitro. DS enhanced I/R-induced increases in levels of calcitonin-gene related peptide (CGRP), a neuropeptide released from sensory neurons, and of 6-ketoprostaglandin (PG) F1α, a stable metabolite of PGI2, in liver tissues. The therapeutic effects of DS were not seen in animals pretreated with capsazepine, an inhibitor of sensory neuron activation. The distribution of heparan sulfate in the perivascular area was significantly increased by DS administration in this rat model. DS significantly increased CGRP release from isolated rat dorsal root ganglion neurons (DRG) in vitro, while DX-9065a, a selective inhibitor of activated factor X, did not. DS enhanced anandamide-induced CGRP release from DRG in vitro. These observations strongly suggested that DS might reduce I/R-induced liver injury in rats by attenuating inflammatory responses. These therapeutic effects of DS might be at least partly explained by its enhancement of sensory neuron activation, leading to the increase the endothelial production of PGI2.

2006 ◽  
Vol 95 (05) ◽  
pp. 788-795 ◽  
Author(s):  
Naoaki Harada ◽  
Mitsuhiro Uchiba ◽  
Hiroki Kurihara ◽  
Naomi Nakagata ◽  
Kenji Okajima

SummaryWe recently demonstrated that antithrombin (AT) reduces ischemia/reperfusion (I/R)-induced liver injury in rats by increasing hepatic tissue levels of calcitonin gene-related peptide (CGRP),a neuropeptide released from the sensory nerve endings. In the present study, we examined the effect of AT on I/Rinduced liver injury in wild type mice (CGRP+/+) and congenitally αCGRP-deficient mice (CGRP−/−). We also investigated any effects of AT on CGRP release from dorsal root ganglion neurons (DRG) isolated from CGRP+/+. Based on results obtained in the present study, we attempted to determine if the anti-inflammatory activity of AT in vivo is dependent mainly on sensory neuron activation. AT enhanced ischemia/reperfusion-induced increases in hepatic tissue levels of CGRP and 6-keto-PGF1α , a stable metabolite of PGI2, in CGRP+/+, but it did not enhance these increases in CGRP−/−. AT inhibited reperfusion-induced increases in serum alanine aminotransferase levels by increasing hepatic tissue blood flow and by attenuating increases in hepatic levels of tumor necrosis factor and myeloperoxidase in CGRP+/+,although it showed neither of these therapeutic effects in CGRP−/−. AT increased CGRP release from cultured DRGs only in the presence of anandamide, and AT-induced increase in CGRP release was not observed in the presence KT5720, an inhibitor of protein kinase A (PKA).AT markedly increased intracellular levels of cAMP in the presence of anandamide. These results strongly suggest that AT might reduce I/R-induced liver injury by enhancing activation of the sensory neurons through activation of PKA in sensory neurons.


2005 ◽  
Vol 93 (01) ◽  
pp. 48-56 ◽  
Author(s):  
Naoaki Harada ◽  
Mehtap Yuksel ◽  
Hirotaka Isobe ◽  
Kenji Okajima

SummaryWe previously reported that antithrombin (AT) reduced ischemia/ reperfusion (I/R)-induced liver injury in rats by increasing endothelial production of prostacyclin (PGI2). However, the mechanism(s) underlying this phenomenon remains to be fully elucidated. We also demonstrated that activation of capsaicinsensitive sensory neurons increased endothelial production of PGI2 by releasing calcitonin gene-related peptide (CGRP) in rats subjected to hepatic I/R. In the present study, we investigated whether AT increases endothelial production of PGI2 through activation of the sensory neurons in rats subjected to hepatic I/R. AT significantly enhanced the I/R-induced increases in hepatic tissue levels of CGRP in rats. Increases in hepatic tissue levels of 6-keto-PGF1α, a stable metabolite of PGI2 , the increase in hepatic-tissue blood flow, and attenuation of both hepatic local inflammatory responses and liver injury in rats administered AT were completely reversed by administration of capsazepine, an inhibitor of sensory neuron activation and CGRP(8–37), a CGRP antagonist.AT did not show any protective effect on liver injury in animals undergoing functional denervation by administration of a large amount of capsaicin.AT significantly increased CGRP release from cultured dorsal root ganglion neurons isolated from rats in the presence of capsaicin.Taken together,these observations strongly suggested that AT might increase hepatic tissue levels of PGI2 via enhancement of hepatic I/R-induced activation of capsaicin-sensitive sensory neurons,thereby reducing liver injury in rats. In this process, CGRP-induced activation of both endothelial nitric oxide synthase and cyclooxygenase-1 might be critically involved.


2002 ◽  
Vol 88 (09) ◽  
pp. 473-480 ◽  
Author(s):  
Naoaki Harada ◽  
Shigeki Kushimoto ◽  
Mitsuhiro Uchiba ◽  
Kenji Okajima

SummaryAlthough tumor necrosis factor-α (TNF-α) has been shown to play a critical role in the pathologic process leading to ischemia/reperfusion (I/R)-induced liver injury in rats by activating neutrophils, it is not clear whether or not microthrombus formation induced by TNF-α contributes to the liver injury. In the present study, we investigated the role of microthrombus formation in I/R-induced liver injury in rats. Hepatic tissue levels of TNF-α were significantly increased after reperfusion, and these were higher in animals subjected to 120 min-hepatic I/R than in those subjected to 60 min-hepatic I/R. Fibrin deposition was observed histologically in the hepatic sinusoidal space only in animals subjected to 120 min-hepatic I/R. Both the decrease in hepatic tissue blood flow and the extent of liver injury in animals subjected to 60 minand 120 min-hepatic I/R were significantly inhibited by pretreatment with anti-rat TNF-α antibody. Although neutrophil elastase inhibitors inhibited the decrease in hepatic tissue blood flow and reduced liver injury in animals subjected to 60 min-hepatic I/R, anticoagulants did not show any effects. Both anticoagulants and neutrophil elastase inhibitors inhibited the decrease in hepatic tissue blood flow and reduced liver injury in animals subjected to 120 min-hepatic I/R. Therapeutic effects of anti-rat TNF-α antibody on the120 min-I/R-induced liver injury were more marked than those of each anticoagulant or each neutrophil elastase inhibitor, and were comparable to those of combined use of anticoagulants and neutrophil elastase inhibitors. These observations strongly suggest that TNF-α induces I/R-induced liver injury primarily by activating neutrophils, and it exacerbates liver injury by inducing microthrombus formation when the production of TNF-α is further increased.


2004 ◽  
Vol 92 (09) ◽  
pp. 550-558 ◽  
Author(s):  
Naoaki Harada ◽  
Mitsuhiro Uchiba ◽  
Shigeki Kushimoto ◽  
Hirotaka Isobe ◽  
Kenji Okajima

SummaryThis study was conducted to determine which isoform of cyclooxygenase (COX) is more significantly involved in the antithrombin (AT)-induced increase in prostaglandin production in the liver of rats, subjected to hepatic ischemia/reperfusion (I/R). Hepatic tissue levels of 6-keto-PGF1α, a stable metabolite of prostacyclin (PGI2), and PGE2 were transiently increased 1 hour after reperfusion. Thereafter, hepatic PGE2 levels were gradually increased until 6 hours after reperfusion, while hepatic 6-keto-PGF1α levels were decreased to the pre-ischemia levels at 6 hours after reperfusion. AT significantly enhanced increases in hepatic tissue levels of 6-keto-PGF1α and PGE2 seen 1 hour after reperfusion, while it inhibited increases in hepatic PGE2 levels seen 6 h after reperfusion. Neither dansyl-Glu-Gly-Arg-chloromethyl ketone-treated factor Xa (DEGR-Xa), a selective inhibitor of thrombin generation, nor Trp49-modified AT which lacks affinity for heparin, showed any effects on these changes. Pretreatment with indomethacin (IM), a non-selective inhibitor of COX, inhibited AT-induced increases in hepatic tissue levels of 6-keto-PGF1α and PGE2 seen 1 hour after reperfusion, whereas pretreatment with NS-398, a selective inhibitor of COX-2, did not. The increase in hepatic tissue blood flow and inhibition of hepatic inflammatory responses seen in animals given AT were reversed by pretreatment with IM, but were not affected by pretreatment with NS-398. Administration of iloprost, a stable analog of PGI2, and PGE2 produced effects similar to those induced by AT. Increases in hepatic tissue levels of PGE2 6 hours after reperfusion were inhibited by pretreatment with NS-398. Although AT did not affect COX-1 mRNA levels 1 hour after reperfusion, it inhibited the I/R-induced increases in hepatic tissue levels of both PGE2 and COX-2 mRNA 6 hours after reperfusion. These observations strongly suggested that AT might reduce the I/R-induced liver injury by increasing the production of PGI2 and PGE2 through activation of COX-1. Furthermore, since TNF-a is capable of inducing COX-2, inhibition of TNF-a production by AT might inhibit COX-2-mediated PGE2 production. These effects induced by AT might contribute to its anti-inflammatory activity.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Da Tang ◽  
Guang Fu ◽  
Wenbo Li ◽  
Ping Sun ◽  
Patricia A. Loughran ◽  
...  

Abstract Background Hepatic ischemia/reperfusion (I/R) injury can be a major complication following liver surgery contributing to post-operative liver dysfunction. Maresin 1 (MaR1), a pro-resolving lipid mediator, has been shown to suppress I/R injury. However, the mechanisms that account for the protective effects of MaR1 in I/R injury remain unknown. Methods WT (C57BL/6J) mice were subjected to partial hepatic warm ischemia for 60mins followed by reperfusion. Mice were treated with MaR1 (5-20 ng/mouse), Boc2 (Lipoxin A4 receptor antagonist), LY294002 (Akt inhibitor) or corresponding controls just prior to liver I/R or at the beginning of reperfusion. Blood and liver samples were collected at 6 h post-reperfusion. Serum aminotransferase, histopathologic changes, inflammatory cytokines, and oxidative stress were analyzed to evaluate liver injury. Signaling pathways were also investigated in vitro using primary mouse hepatocyte (HC) cultures to identify underlying mechanisms for MaR1 in liver I/R injury. Results MaR1 treatment significantly reduced ALT and AST levels, diminished necrotic areas, suppressed inflammatory responses, attenuated oxidative stress and decreased hepatocyte apoptosis in liver after I/R. Akt signaling was significantly increased in the MaR1-treated liver I/R group compared with controls. The protective effect of MaR1 was abrogated by pretreatment with Boc2, which together with MaR1-induced Akt activation. MaR1-mediated liver protection was reversed by inhibition of Akt. Conclusions MaR1 protects the liver against hepatic I/R injury via an ALXR/Akt signaling pathway. MaR1 may represent a novel therapeutic agent to mitigate the detrimental effects of I/R-induced liver injury.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Jian-Ping Zhang ◽  
Wei-Jing Zhang ◽  
Miao Yang ◽  
Hua Fang

Abstract Background Propofol, an intravenous anesthetic, was proven to protect against lung ischemia/reperfusion (I/R) injury. However, the detailed mechanism of Propofol in lung I/R injury is still elusive. This study was designed to explore the therapeutic effects of Propofol, both in vivo and in vitro, on lung I/R injury and the underlying mechanisms related to metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-144 (miR-144)/glycogen synthase kinase-3β (GSK3β). Methods C57BL/6 mice were used to establish a lung I/R injury model while pulmonary microvascular endothelial cells (PMVECs) were constructed as hypoxia/reperfusion (H/R) cellular model, both of which were performed with Propofol treatment. Gain- or loss-of-function approaches were subsequently employed, followed by observation of cell apoptosis in lung tissues and evaluation of proliferative and apoptotic capabilities in H/R cells. Meanwhile, the inflammatory factors, autophagosomes, and autophagy-related proteins were measured. Results Our experimental data revealed that Propofol treatment could decrease the elevated expression of MALAT1 following I/R injury or H/R induction, indicating its protection against lung I/R injury. Additionally, overexpressing MALAT1 or GSK3β promoted the activation of autophagosomes, proinflammatory factor release, and cell apoptosis, suggesting that overexpressing MALAT1 or GSK3β may reverse the protective effects of Propofol against lung I/R injury. MALAT1 was identified to negatively regulate miR-144 to upregulate the GSK3β expression. Conclusion Overall, our study demonstrated that Propofol played a protective role in lung I/R injury by suppressing autophagy and decreasing release of inflammatory factors, with the possible involvement of the MALAT1/miR-144/GSK3β axis.


2011 ◽  
Vol 32 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Amy E B Packard ◽  
Jason C Hedges ◽  
Frances R Bahjat ◽  
Susan L Stevens ◽  
Michael J Conlin ◽  
...  

Preconditioning induces ischemic tolerance, which confers robust protection against ischemic damage. We show marked protection with polyinosinic polycytidylic acid (poly-IC) preconditioning in three models of murine ischemia-reperfusion injury. Poly-IC preconditioning induced protection against ischemia modeled in vitro in brain cortical cells and in vivo in models of brain ischemia and renal ischemia. Further, unlike other Toll-like receptor (TLR) ligands, which generally induce significant inflammatory responses, poly-IC elicits only modest systemic inflammation. Results show that poly-IC is a new powerful prophylactic treatment that offers promise as a clinical therapeutic strategy to minimize damage in patient populations at risk of ischemic injury.


2012 ◽  
Vol 40 (02) ◽  
pp. 321-334 ◽  
Author(s):  
Jeong-Won Lee ◽  
Sok Cheon Pak ◽  
Songhee Jeon ◽  
Dong-Il Kim

Yukmijihwangtang (YM), a boiled extract of medicinal plants, has been prescribed for patients with kidney dysfunction in Korea; however, the mechanism underlying its therapeutic effects has not been fully elucidated. This study was conducted to evaluate the beneficial effects on bladder function by using modified YM (M-YM), which included Ulmi radicis cortex in addition to the six traditional medicinal plants in YM. Bladder irritation of the rats was caused by intravesical instillation of HCl . The animals were divided into six groups: sham group, cystitis-injury group with no treatment, cystitis-injury group with prednisolone treatment (5 mg/kg), and cystitis-injury with M-YM treatment (100, 200 or 500 mg/kg groups). Whole bladders were collected at day eight after injury. Samples were analyzed by histological and immunological examinations. An in vitro study was performed to determine whether M-YM extracts inhibit lipopolysaccharide (LPS)-induced nitric oxide (NO) production and I κ B phosphorylation in a human uroepithelial cell line of T24 cells. Administration of M-YM notably improved bladder histological changes, and suppressed IL-6/TNF α production and I κ B phosphorylation in a rat model of chronic cystitis. M-YM also inhibited LPS-induced NO production and I κ B phosphorylation in T24 cells. This study suggests that administration of M-YM might be an applicable therapeutic traditional medicine for the treatment of interstitial cystitis.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Qian-wei Li ◽  
Qin Yang ◽  
Hong-Yang Liu ◽  
Yu-ling Wu ◽  
Yu-Hua Hao ◽  
...  

Sepsis increases the risk of the liver injury development. According to the research works, coenzyme Q10 exhibits hepatoprotective properties in vivo as well as in vitro. Current work aimed at investigating the protective impacts of coenzyme Q10 against liver injury in septic BALB/c mice. The male BALB/c mice were randomly segregated into 4 groups: the control group, the coenzyme Q10 treatment group, the puncture and cecal ligation group, and the coenzyme Q10+cecal ligation and puncture group. Cecal ligation and puncture was conducted after gavagaging the mice with coenzyme Q10 during two weeks. Following 48 h postcecal ligation and puncture, we estimated hepatic biochemical parameters and histopathological changes in hepatic tissue. We evaluated the expression of factors associated with autophagy, pyroptosis, and inflammation. Findings indicated that coenzyme Q10 decreased the plasma levels in alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase in the cecal ligation and puncture group. Coenzyme Q10 significantly inhibited the elevation of sequestosome-1, interleukin-1β, oligomerization domain-like receptor 3 and nucleotide-binding, interleukin-6, and tumor necrosis factor-α expression levels; coenzyme Q10 also increased beclin 1 levels. Coenzyme Q10 might be a significant agent in the treatment of liver injury induced by sepsis.


Sign in / Sign up

Export Citation Format

Share Document