scholarly journals Deficiency of IKKα in Macrophages Mitigates Fibrosis Progression in the Kidney after Renal Ischemia-Reperfusion Injury

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Feng Zhang ◽  
Li Fan ◽  
Hao Zhang ◽  
Wen-juan Huang ◽  
Dong Sun ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Renal Ischemia ◽  
Inflammatory Factors ◽  
Iri Model ◽  
Iκb Kinase ◽  
Renal Ischemia Reperfusion Injury

Aims. Acute kidney injury (AKI) can lead to chronic kidney disease (CKD), and macrophages play a key role in this process. The aim of this study was to discover the role of IκB kinase α (IKKα) in macrophages in the process of AKI-to-CKD transition. Main Methods. We crossed lyz2-Cre mice with IKKα-floxed mice to generate mice with IKKα ablation in macrophages (Mac IKKα-/-). A mouse renal ischemia/reperfusion injury (IRI) model was induced by clamping the renal artery for 45 minutes. Treated mice were evaluated for blood biochemistry, tissue histopathology, and fibrosis markers. Macrophages were isolated from the peritoneal cavity for coculturing with tubular epithelial cells (TECs) and flow cytometry analysis. Key Findings. We found that fibrosis and kidney function loss after IRI were significantly alleviated in Mac IKKα-/- mice compared with wild-type (WT) mice. The expression of fibrosis markers and the infiltration of M2 macrophages were decreased in the kidneys of Mac IKKα-/- mice after IRI. The in vitro experiment showed that the IRI TECs cocultured with IKKα-/- macrophages (KO MΦs) downregulated the fibrosis markers accompanied by a downregulation of Wnt/β-catenin signaling. Significance. These data support the hypothesis that IKKα is involved in mediating macrophage polarization and increasing the expression of fibrosis-promoting inflammatory factors in macrophages. Therefore, knockdown of IKKα in macrophages may be a potential method that can be used to alleviate the AKI-to-CKD transition after IRI.

scholarly journals Overexpression of SP1 restores autophagy to alleviate acute renal injury induced by ischemia-reperfusion through the miR-205/PTEN/Akt pathway

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Chong Huang ◽  
Yan Chen ◽  
Bin Lai ◽  
Yan-Xia Chen ◽  
Cheng-Yun Xu ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Cell Apoptosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Akt Pathway ◽  
Acute Renal Injury ◽  
Injury Model ◽  
Renal Ischemia Reperfusion Injury

Abstract Background Acute kidney injury (AKI) is a major kidney disease with poor clinical outcome. SP1, a well-known transcription factor, plays a critical role in AKI and subsequent kidney repair through the regulation of various cell biologic processes. However, the underlying mechanism of SP1 in these pathological processes remain largely unknown. Methods An in vitro HK-2 cells with anoxia-reoxygenation injury model (In vitro simulated ischemic injury disease) and an in vivo rat renal ischemia-reperfusion injury model were used in this study. The expression levels of SP1, miR-205 and PTEN were detected by RT-qPCR, and the protein expression levels of SP1, p62, PTEN, AKT, p-AKT, LC3II, LC3I and Beclin-1 were assayed by western blot. Cell proliferation was assessed by MTT assay, and the cell apoptosis was detected by flow cytometry. The secretions of IL-6 and TNF-α were detected by ELISA. The targeted relationship between miR-205 and PTEN was confirmed by dual luciferase report assay. The expression and positioning of LC-3 were observed by immunofluorescence staining. TUNEL staining was used to detect cell apoptosis and immunohistochemical analysis was used to evaluate the expression of SP1 in renal tissue after ischemia-reperfusion injury in rats. Results The expression of PTEN was upregulated while SP1 and miR-205 were downregulated in renal ischemia-reperfusion injury. Overexpression of SP1 protected renal tubule cell against injury induced by ischemia-reperfusion via miR-205/PTEN/Akt pathway mediated autophagy. Overexpression of SP1 attenuated renal ischemia-reperfusion injury in rats. Conclusions SP1 overexpression restored autophagy to alleviate acute renal injury induced by ischemia-reperfusion through the miR-205/PTEN/Akt pathway.

scholarly journals Dexmedetomidine Preconditioning Protects Rats from Renal Ischemia–Reperfusion Injury Accompanied with Biphasic Changes of Nuclear Factor-Kappa B Signaling

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Naren Bao ◽  
Bing Tang ◽  
Junke Wang
Keyword(s):  
Reperfusion Injury ◽  
Nuclear Factor Kappa B ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Nuclear Factor ◽  
Nuclear Factor Kappa ◽  
Renal Ischemia Reperfusion Injury ◽  
Anti Inflammatory

Acute kidney injury (AKI) is one of the most common and troublesome perioperative complications. Dexmedetomidine (DEX) is a potent α2-adrenoceptor (α2-AR) agonist with anti-inflammatory and renoprotective effects. In this study, a rat renal ischemia–reperfusion injury (IRI) model was induced. At 24 h after reperfusion, the IRI-induced damage and the renoprotection of DEX preconditioning were confirmed both biochemically and histologically. Changes in nuclear factor-kappa B (NF-κB), as well as its downstream anti-inflammatory factor A20 and proinflammatory factor tumor necrosis factor-α (TNF-α), were detected. Atipamezole, a nonselective antagonist, was then added 5 min before the administration of DEX to further analyze DEX’s effects on NF-κB, and another anti-inflammatory medicine, methylprednisolone, was used in comparison with DEX, to further analyze DEX’s effects on NF-κB. Different concentrations of DEX (0 nM, 0.1 nM, 1 nM, 10 nM, 100 nM, 1 μM, and 10 μM) were applied to preincubated human renal tubular epithelial cell line (HK-2) cells in vitro. After anoxia and reoxygenation, the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium assay and enzyme-linked immunosorbent assay (ELISA) were performed to evaluate the levels of NF-κB downstream anti-inflammatory cytokines. The results showed that, unlike methylprednisolone, DEX preconditioning led to a time-dependent biphasic change (first activation then inhibition) of NF-κB in the rat renal IRI models that were given 25 μg/kg i.p. It was accompanied by a similarly biphasic change of TNF-α and an early and persistent upregulation of A20. In vitro, DEX’s cellular protection showed a concentration-dependent biphasic change which was protective within the range of 0 to 100 nM but became opposite when concentrations are greater than 1 μM. The changes in the A20 and NF-κB messenger RNA (mRNA) levels were consistent with the renoprotective ability of DEX. In other words, DEX preconditioning protected the rats from renal IRI via regulation biphasic change of NF-κB signaling.

scholarly journals Riclinoctaose Attenuates Renal Ischemia-Reperfusion Injury by the Regulation of Macrophage Polarization

2021 ◽  
Vol 12 ◽  
Author(s):  
Yang Zhao ◽  
Zhao Ding ◽  
Wenhao Ge ◽  
Junhao Liu ◽  
Xi Xu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Renal Ischemia ◽  
M2 Macrophage ◽  
Mouse Bone Marrow ◽  
M1 Macrophage ◽  
Renal Ischemia Reperfusion Injury

Renal ischemia-reperfusion injury is a major trigger of acute kidney injury and leads to permanent renal impairment, and effective therapies remain unresolved. Riclinoctaose is an immunomodulatory octasaccharide composed of glucose and galactose monomers. Here we investigated whether riclinoctaose protects against renal ischemia-reperfusion injury. In mice, pretreatment with riclinoctaose significantly improved renal function, structure, and the inflammatory response after renal ischemia-reperfusion. Flow cytometry analysis revealed that riclinoctaose inhibited ischemia-reperfusion-induced M1 macrophage polarization and facilitated M2 macrophage recruitment into the kidneys. In isolated mouse bone marrow-derived macrophages, pretreatment with riclinoctaose promoted the macrophage polarization toward M2-like phenotype. The inhibitor of Nrf-2/HO-1 brusatol diminished the effects of riclinoctaose on macrophage polarization. In mice, intravenous injection with riclinoctaose-pretreated bone marrow-derived macrophages also protected against renal ischemia-reperfusion injury. Fluorescence-labeled riclinoctaose specifically bound to the membrane of macrophages. Interfering with mDC-SIGN blocked the riclinoctaose function on M2 polarization of macrophages, consequently impairing the renoprotective effect of riclinoctaose. Our results revealed that riclinoctaose is a potential therapeutic agent in preventing renal ischemia-reperfusion injury.

scholarly journals Indoleamine 2,3-dioxygenase expression promotes renal ischemia-reperfusion injury

2008 ◽  
Vol 295 (1) ◽  
pp. F226-F234 ◽  
Author(s):  
Kanishka Mohib ◽  
Shuang Wang ◽  
Qiunong Guan ◽  
Andrew L. Mellor ◽  
Hongtao Sun ◽  
...  
Keyword(s):  
Serum Creatinine ◽  
Reperfusion Injury ◽  
Renal Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Indoleamine 2,3 Dioxygenase ◽  
Renal Ischemia Reperfusion Injury

Indoleamine 2,3-dioxygenase (IDO) catabolizes tryptophan to N-formyl kynurenine and has a proapoptotic role in renal tubular epithelial cells (TEC) in response to IFN-γ and TNF-α in vitro. TEC produce abundant amounts of IDO in vitro in response to inflammation but a pathological role for IDO in renal injury remains unknown. We investigated the role of IDO in a mouse model of renal ischemia-reperfusion injury (IRI). IRI was induced by clamping the renal pedicle of C57BL/6 mice for 45 min at 32°C. Here, we demonstrate upregulation of IDO in renal tissue at 2 h after reperfusion which reached maximal levels at 24 h. Inhibition of IDO following IRI prevented the increase in serum creatinine observed in vehicle-treated mice (86.4 ± 25 μmol/l, n = 11) compared with mice treated with 1-methyl-d-tryptophan, a specific inhibitor of IDO (33.7 ± 8.7 μmol/l, n = 10, P = 0.031). The role of IDO in renal IRI was further supported by results in IDO-KO mice which maintained normal serum creatinine levels (32.5 ± 2.0 μmol/l, n = 6) following IRI compared with wild-type mice (123 ± 30 μmol/l, n = 9, P = 0.008). Our data suggest that attenuation of IDO expression within the kidney may represent a novel strategy to reduce renal injury as a result of ischemia reperfusion.

scholarly journals Inhibition of Endothelial PHD2 Suppresses Post-Ischemic Kidney Inflammation through Hypoxia-Inducible Factor-1

2020 ◽  
Vol 31 (3) ◽  
pp. 501-516 ◽  
Author(s):  
Ganeshkumar Rajendran ◽  
Michael P. Schonfeld ◽  
Ratnakar Tiwari ◽  
Shengping Huang ◽  
Rafael Torosyan ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Molecular Mechanisms ◽  
Oxygen Sensor ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Hypoxia Inducible Factor ◽  
Inflammatory Cells ◽  
Renal Ischemia ◽  
Renal Ischemia Reperfusion Injury

BackgroundProlyl-4-hydroxylase domain-containing proteins 1–3 (PHD1 to PHD3) regulate the activity of the hypoxia-inducible factors (HIFs) HIF-1 and HIF-2, transcription factors that are key regulators of hypoxic vascular responses. We previously reported that deficiency of endothelial HIF-2 exacerbated renal ischemia-reperfusion injury, whereas inactivation of endothelial PHD2, the main oxygen sensor, provided renoprotection. Nevertheless, the molecular mechanisms by which endothelial PHD2 dictates AKI outcomes remain undefined.MethodsTo investigate the function of the endothelial PHD2/HIF axis in ischemic AKI, we examined the effects of endothelial-specific ablation of PHD2 in a mouse model of renal ischemia-reperfusion injury. We also interrogated the contribution of each HIF isoform by concurrent endothelial deletion of both PHD2 and HIF-1 or both PHD2 and HIF-2.ResultsEndothelial deletion of Phd2 preserved kidney function and limited transition to CKD. Mechanistically, we found that endothelial Phd2 ablation protected against renal ischemia-reperfusion injury by suppressing the expression of proinflammatory genes and recruitment of inflammatory cells in a manner that was dependent on HIF-1 but not HIF-2. Persistence of renoprotective responses after acute inducible endothelial-specific loss of Phd2 in adult mice ruled out a requirement for PHD2 signaling in hematopoietic cells. Although Phd2 inhibition was not sufficient to induce detectable HIF activity in the kidney endothelium, in vitro experiments implicated a humoral factor in the anti-inflammatory effects generated by endothelial PHD2/HIF-1 signaling.ConclusionsOur findings suggest that activation of endothelial HIF-1 signaling through PHD2 inhibition may offer a novel therapeutic approach against ischemic AKI.

scholarly journals Blocking neutrophil integrin activation prevents ischemia–reperfusion injury

2015 ◽  
Vol 212 (8) ◽  
pp. 1267-1281 ◽  
Author(s):  
Tadayuki Yago ◽  
Brian G. Petrich ◽  
Nan Zhang ◽  
Zhenghui Liu ◽  
Bojing Shao ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Integrin Activation ◽  
Β2 Integrin ◽  
Renal Ischemia Reperfusion Injury ◽  
Slow Rolling

Neutrophil recruitment, mediated by β2 integrins, combats pyogenic infections but also plays a key role in ischemia–reperfusion injury and other inflammatory disorders. Talin induces allosteric rearrangements in integrins that increase affinity for ligands (activation). Talin also links integrins to actin and other proteins that enable formation of adhesions. Structural studies have identified a talin1 mutant (L325R) that perturbs activation without impairing talin’s capacity to link integrins to actin and other proteins. Here, we found that mice engineered to express only talin1(L325R) in myeloid cells were protected from renal ischemia–reperfusion injury. Dissection of neutrophil function in vitro and in vivo revealed that talin1(L325R) neutrophils had markedly impaired chemokine-induced, β2 integrin–mediated arrest, spreading, and migration. Surprisingly, talin1(L325R) neutrophils exhibited normal selectin-induced, β2 integrin–mediated slow rolling, in sharp contrast to the defective slow rolling of neutrophils lacking talin1 or expressing a talin1 mutant (W359A) that blocks talin interaction with integrins. These studies reveal the importance of talin-mediated activation of integrins for renal ischemia–reperfusion injury. They further show that neutrophil arrest requires talin recruitment to and activation of integrins. However, although neutrophil slow rolling requires talin recruitment to integrins, talin-mediated integrin activation is dispensable.

Renal ischemia/reperfusion injury: An insight on in vitro and in vivo models

Life Sciences ◽  
2020 ◽  
Vol 256 ◽  
pp. 117860 ◽  
Author(s):  
Niharika Shiva ◽  
Nisha Sharma ◽  
Yogesh A. Kulkarni ◽  
Shrikant R. Mulay ◽  
Anil Bhanudas Gaikwad
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
In Vivo Models ◽  
Renal Ischemia Reperfusion Injury

scholarly journals PO-032 The protective effects of curcumin on exercise-induced renal ischemia reperfusion injury in rats

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Fang Li ◽  
Jianmin Cao ◽  
Haitao Zhou ◽  
Yanlong Niu
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Inflammatory Factors ◽  
Control Group ◽  
Renal Ischemia Reperfusion Injury ◽  
Group A ◽  
Exercise Induced ◽  
Group B

Objective This study was designed to investigate the effects  of curcumin on inflammatory factors and ECM expression in exercise-induced renal ischemia reperfusion injury in rats. Methods Sixty 7-week-old male SD rats were divided randomly into three groups: group A (normal control group, n=12), group B (overtraining group, n=24) and group C (curcumin + overtraining group, n=24). Group B and C  performed 6 weeks of incremental load training on the treadmill.  24 hours after the last training, the rats were anesthetized intraperitoneally, the morphology of renal tissue and the deposition of glomerular ECM were observed using light microscope，the related biochemical indexes were tested. Results (1) the renal structure of rats in group A were normal,  histopathological changes were observed  in group B and  C, Paller score of group B were significantly higher than group A(P <0.01), and that of group C were significantly lower than group B(P <0.05). (2) Blood urea nitrogen (BUN) and serum creatinine (Scr), serum and renal inflammatory factors , TGF-β protein expression level and glomerular ECM deposition of  group B  were significantly higher than group A(P<0.01)  and those of group C were lower than group B(P<0.05). Conclusions  Supplementation of curcumin can effectively  protect rats from exercise-induced renal ischemia reperfusion injury, by inhibiting the up-regulation of inflammatory cytokines and TGF-β expression and maintaining the dynamic balance of ECM .

scholarly journals TSC1 Affects the Process of Renal Ischemia-Reperfusion Injury by Controlling Macrophage Polarization

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiao Hu ◽  
Yanan Xu ◽  
Zhaoqi Zhang ◽  
Zuofu Tang ◽  
Jinhua Zhang ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Early Phase ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Renal Ischemia ◽  
Negative Regulator ◽  
Activated Macrophages ◽  
Renal Ischemia Reperfusion Injury ◽  
Repair Phase

Renal ischemia-reperfusion injury (IRI) contributes to acute kidney injury (AKI), increases morbidity and mortality, and is a significant risk factor for chronic kidney disease (CKD). Macrophage infiltration is a common feature after renal IRI, and infiltrating macrophages can be polarized into the following two distinct types: M1 macrophages, i.e., classically activated macrophages, which can not only inhibit infection but also accelerate renal injury, and M2 macrophages, i.e., alternatively activated macrophages, which have a repair phenotype that can promote wound healing and subsequent fibrosis. The role of TSC1, which is a negative regulator of mTOR signaling that regulates macrophage polarization in inflammation-linked diseases, has been well documented, but whether TSC1 contributes to macrophage polarization in the process of IRI is still unknown. Here, by using a mouse model of renal ischemia-reperfusion, we found that myeloid cell-specific TSC1 knockout mice (termed Lyz-TSC1 cKO mice) had higher serum creatinine levels, more severe histological damage, and greater proinflammatory cytokine production than wild-type (WT) mice during the early phase after renal ischemia-reperfusion. Furthermore, the Lyz-TSC1 cKO mice showed attenuated renal fibrosis during the repair phase of IRI with decreased levels of M2 markers on macrophages in the operated kidneys, which was further confirmed in a cell model of hypoxia-reoxygenation (H/R) in vitro. Mechanistically, by using RNA sequencing of sorted renal macrophages, we found that the expression of most M1-related genes was upregulated in the Lyz-TSC1 cKO group (Supplemental Table 1) during the early phase. However, C/EBPβ and CD206 expression was decreased during the repair phase compared to in the WT group. Overall, our findings demonstrate that the expression of TSC1 in macrophages contributes to the whole process of IRI but serves as an inflammation suppressor during the early phase and a fibrosis promoter during the repair phase.

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