scholarly journals Vildagliptin Attenuates Hepatic Ischemia/Reperfusion Injury via the TLR4/NF-κB Signaling Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Iman O. Sherif ◽  
Nora H. Al-Shaalan

The Toll-like receptor-4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway is vital in the pathogenesis of hepatic ischemia/reperfusion (HIR) injury. Dipeptidyl peptidase-4 (DPP4) inhibitors exert protective effects on IR injury of the kidney, heart, and lung; however, their effect on the liver is still unknown. Thus, the purpose of this study was to examine whether pretreatment with vildagliptin (Vilda), a DPP4 inhibitor, produces hepatic protection against IR injury and to investigate its influence on TLR4/NF-κB signaling in a rat model. Thirty male Wistar rats were divided into 3 groups: the sham group: subjected to a sham operation and received normal saline; the HIR group: subjected to HIR and received normal saline; and the Vilda + HIR group: subjected to HIR with pretreatment of 10 mg/kg/day Vilda for 10 days intraperitoneally. Hepatic ischemia lasted for 45 minutes followed by 3-hour reperfusion; then blood and liver samples were collected for biochemical and histopathological examination. The HIR group produced a significant increase in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hepatic malondialdehyde (MDA), nitric oxide (NO), and tumor necrosis factor alpha (TNF-α) levels and a significant reduction in the hepatic catalase level in comparison to the sham group. Moreover, a significant upregulation of gene and protein expressions of TLR4, NF-κB, and high-mobility group box-1 (HMGB1) along with caspase-3 protein expression was observed in the HIR group when compared with the sham group. Histopathological examination of the liver from the HIR group showed necrosis, sinusoidal congestion, hemorrhage, and hepatocyte degeneration. Administration of Vilda ameliorated the biochemical and histopathological changes caused by HIR. Vildagliptin showed for the first time a hepatoprotective effect in HIR injury through downregulation of TLR4/NF-κB/HMGB1 and caspase-3 hepatic expressions.

2021 ◽  
Vol 11 (8) ◽  
pp. 1536-1542
Author(s):  
Zhao Hai-Fan ◽  
Li Chong ◽  
Hu Zhi-Duo ◽  
Chen Hong ◽  
Jiang Tao ◽  
...  

Purpose: Explore the dexmedetomidine’s therapeutic impact on hepatic ischemia-reperfusion (I/R) injury and the related principle. Methods: The work established the rats’ liver I/R model. Liver tissues’ pathological state from each rat was evaluated by HE staining. ELISA was utilized to confirm the activity of MDA and SOD in the liver tissue, AST in the serum, and the ALT’s concentration. The apoptotic state of liver tissue was detected by TUNEL assay. Bcl-2, Caspase-3, HO-1, and BAX’s expressions of each rat’s liver tissue had been confirmed through immunohistochemistry and western blot. Results: Rats’ liver injury from I/R group and DEX+A group was rat’s liver tissue had been confirmed through immunohistochemistry and western blot. severer than that from Sham group in terms of HE staining and ELISA. The injured tissue has been improved by the introduction of Dexmedetomidine. The TUNEL, Immunohistochemistry and Western Blot results indicated that the high apoptotic rate in I/R model was inhibited using Dexmedetomidine. However, the inhibitory effects were reversed by the co-administration of Atipamezole. Conclusion: Dexmedetomidine suppressed apoptosis to alleviate rats’ hepatic ischemia-reperfusion injuries.


2011 ◽  
Vol 26 (suppl 1) ◽  
pp. 8-13 ◽  
Author(s):  
Raimundo José Cunha Araújo Júnior ◽  
Raimundo Gerônimo da Silva Júnior ◽  
Marcelo Pinho Pessoa de Vasconcelos ◽  
Sérgio Botelho Guimarães ◽  
Paulo Roberto Leitão de Vasconcelos ◽  
...  

PURPOSE: To evaluate the effects of pre-conditioning with L-alanyl- glutamine (L-Ala-Gln) in rats subjected to total hepatic ischemia. METHODS: Thirty Wistar rats, average weight 300g, were randomly assigned to 3 groups (n=10): G-1 - Saline, G-2- L-Ala-Gln, G-3-control (Sham). G-1 and G-3 groups were treated with saline 2.0 ml or L-Ala-Gln (0.75mg/Kg) intraperitoneally (ip) respectively, 2 hours before laparotomy. Anesthetized rats were subjected to laparotomy and total hepatic ischemia (30 minutes) induced by by clamping of portal triad. Control group underwent peritoneal puncture, two hours before the sham operation (laparotomy only). At the end of ischemia (G1 and G2), the liver was reperfused for 60 minutes. Following reperfusion blood samples were collected for evaluation of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels. Liver (medium lobe) was removed for immunohistochemistry study with antibody for Caspase-3. RESULTS: It was found a significant decrease (p<0.05) of ALT levels (270.6 +40.8 vs 83.3 +5.5 - p <0.05), LDH (2079.0 +262.4 vs. 206.6 +16.2 - p <0.05) and Caspase-3 expression (6.72 +1.35 vs. 2.19 +1.14, p <0.05) in rats subjected to I / R, comparing the group treated with L-Ala -Gln with G-2. Also, the ALT level was significantly lower (P<0.05) in G-1 and G-2 groups than in G-3 (control group). CONCLUSION: L-Ala-Gln preconditioning in rats submitted to hepatic I/R significantly reduces ALT, LDH and Caspase-3 expression, suggesting hepatic protection.


Author(s):  
Lai Wei ◽  
Yinyin Su ◽  
Siyou Tan ◽  
Yi Zou ◽  
Yixun Tang ◽  
...  

The current study set out to investigate the molecular mechanism of electroacupuncture (EA) stimulation at Yanglingquan acupoint (GB34) in hepatic ischemia-reperfusion injury (HIRI) in rats via regulation of the endothelin-1 (ET-1) mediated transforming growth factor-β-activated kinase-1 (TAK1)-c-Jun NH2-terminal kinase (JNK)/p38 signaling pathway. First, EA stimulation was applied to the constructed rat model of HIRI at GB34. Subsequently, the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and myeloperoxidase (MPO) in liver tissues were measured. Apoptotic changes in liver tissues in rats with HIRI were observed using TUNEL staining. Western blot assay was employed to determine the expression patterns of Bcl-2, Bax, c-caspase-3 and the activation of TAK1-JNK/p38 signaling pathway, and immunohistochemistry was conducted to determine the protein expression patterns of c-caspase-3 and ET-1. In addition, ELISA was performed to determine the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 in serum. The results demonstrated a significant decline in the activities of AST and ALT and hepatocyte apoptosis in rats with HIRI following EA stimulation. Meanwhile, EA stimulation brought about decreases in the expression levels of Bcl-2, Bax and c-caspase-3, MPO activity, TNF-α, IL-1β and IL-6 in serum, and diminished those of ET-1 in liver tissues, in addition to inhibiting the TAK1-JNK/p38 signaling pathway. Over-expression of ET-1 could counter the inhibitory effects of EA stimulation of HIRI in rats. Together, our findings indicate that EA stimulation at GB34 down-regulates the expression of ET-1, which inhibits the TAK1-JNK/p38 signaling pathway, consequently alleviating HIRI in rats.


2021 ◽  
Author(s):  
Lei Yan ◽  
Heng Luo ◽  
Xingsheng Li ◽  
Yongyong Li

Abstract Background: Hepatic ischemia-reperfusion injury (IRI) is a major unavoidable clinical problem often occurs during various liver surgery and transplantation. D-Pinitol, a cyclic polyol, showed its hepatoprotective efficacy in clinical and experimental settings. Aim: To determine the potential and possible mechanism of pinitol against ER stress regulation-mediated hepatic IRI in experimental rats.Materials and methods: Male SD rats were pre-treated with pinitol for 21 days and then subjected to 60 min. of partial hepatic ischemia followed by 24 h. of reperfusion. Various parameters were evaluated, including liver function tests, inflammatory release, endoplasmic reticulum (ER) stress, apoptosis, and structural modifications.Results: Pre-treatment with pinitol (10 and 20 mg/kg) effectively protected IRI-induced hepatic damage reflected by attenuation of elevated AST, ALT, oxidative stress (SOD, GSH, MDA and NO) and pro-inflammatory cytokines (TNF-α and IL’s) release. Interestingly, western blot and ELISA analysis suggested that pinitol significantly down-regulated the expression of ER stress apoptotic markers, namely GRP78, CHOP, AFT-4, AFT-6α, XBP-1, and caspase-3, 9 and 12. Additionally, pinitol pre-treatment improved mitochondrial function and phosphorylation of ERK1/2 and P38. Pinitol markedly protected IRI-induced hepatic apoptosis determined by flow cytometry. The hepatic histological and ultrastructural aberration induced by IRI was effectively protected by pinitol. Conclusion: Findings of the present investigation suggested that pinitol offered protection against ER stress-mediated phosphorylation of ERK1/2 and p38, thereby inhibited AFT4-CHOP/GRP78 signaling response and induction of caspase-3 induced hepatocellular apoptosis during hepatic ischemia-reperfusion insults.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Hao Wu ◽  
He Bai ◽  
Shigang Duan ◽  
Fangchao Yuan

Background. Serine hydroxymethyltransferase 2 (SHMT2) activity ensures that cells have a survival advantage in ischemic conditions and regulates redox homeostasis. In this study, we aimed to investigate the role of SHMT2 after hepatic ischemia-reperfusion (IR), which involves hypoxia, ischemic conditions, and cell apoptosis. Methods. A 70% IR model was established in C57BL/6J mice with or without SHMT2 knockdown. H&E staining, liver weight/body weight, serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels and cell apoptosis were tested to analyze liver damage and function. Then, the related cellular signals were probed. Results. The level of SHMT2 protein was significantly increased at 24 h and 48 h after IR (p<0.001). Mice in the shSHMT2 group showed more necrotic areas and histological damage at 24 h (p<0.01) after IR and higher levels of serum ALT and AST (p<0.05) compared with those of mice in the scramble group. After IR for 24 h, the expression of TUNEL in the shSHMT2 group was significantly higher than that in the scramble group, as shown by histological analysis (p<0.01). Mechanistically, the JNK/P53 signaling pathway was activated by IR, and knockdown of SHMT2 exacerbated hepatocyte apoptosis. Conclusions. Knockdown of SHMT2 worsens IR injury through the ROS/JNK/P53 signaling pathway. Our discovery expands the understanding of both molecular and metabolic mechanisms involved in IR. SHMT2 is a possible therapeutic target to improve the prognosis of liver transplantation (LT) and subtotal hepatectomy.


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