Development of New Small Molecule Bone Marrow Radioprotectors.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4196-4196
Author(s):  
Yunyun Niu ◽  
Anthony J. Kanai ◽  
Peter Wipf ◽  
Xichen Zhang ◽  
Emily E. Greenberger ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Small Molecule ◽  
Ischemia Reperfusion Injury ◽  
Ethyl Pyruvate ◽  
Survival Curve ◽  
Ischemia Reperfusion ◽  
Irradiation Damage ◽  
Before And After ◽  
Nos Inhibitor

Abstract New ways to protect the bone marrow from irradiation damage are required. We are currently developing new small molecules that can be given orally to protect the marrow from irradiation damage. One small molecule is EUK-134, a manganese superoxide dismutase (MnSOD) mimetic. A nitric oxide synthase inhibitor, and a nitroxide homologue which have been both conjugated to a mitochondrial localization peptide signal, delivers the NOS inhibitor (another radioprotector) and nitroxide to the mitochondria. In addition, we tested ethyl pyruvate (EP), which has been demonstrated to protect tissues from ischemia-reperfusion injury at the level of the mitochondria. Incubation of 32D cl 3 hematopoietic cells 1 hour before irradiation in the presence of 20 μM EUK-134 or 100 μM of NOS inhibitor demonstrated an increased shoulder on the irradiation survival curve in one case (n = 5.55 ± 0.17 for EUK-134 compared to 1.60 ± 0.38 for control irradiated, respectively, p = 0.0044) and increase in the D0 for the mitochondrial targeted NOS inhibitor compared to irradiated control 32D cl 3 cells (D0 = 3.04 ± 0.27 compared to 1.29 ± 0.01 Gy, p = 0.0236). In experiments with 32D cl 3 cells in EP before irradiation or following irradiation, there was an increase in the D0 to 2.2 ± 0.25 and 2.21 ± 0.15, respectively, compared to irradiated controls 1.42 ± 0.09 Gy for the 32D cl 3 cells (p = 0.0447 and 0.0119, respectively). Furthermore, incubation of 32D cl 3 cells in EP both before and after irradiation significantly increased the shoulder on the survival curve compared to irradiated control 32D cl 3 cells (n = 4.14 ± 1.59 compared to 1.70 ± 0.6 for the control irradiated cells, respectively, p=0.0485). To determine whether EP protected the bone marrow from irradiation in vivo, C57BL/6J mice were injected with EP intraperitoneally (70 mg/kg) 30 minutes before irradiation, daily for 5 days after irradiation, or both before and following irradiation to the LD 50/30 TBI dose of 900 cGy. Mice injected with EP either after irradiation or both before and after irradiation had prolonged survival compared to irradiated control mice or those injected with EP only before irradiation. (Percent survival at 50 days 100% and 100%, respectively, compared to 60%, p<0.05). These results demonstrate the potential effectiveness of new small molecule bone marrow radioprotectors.

Cardioprotective role of endogenous hydrogen peroxide during ischemia-reperfusion injury in canine coronary microcirculation in vivo

2006 ◽  
Vol 291 (3) ◽  
pp. H1138-H1146 ◽  
Author(s):  
Toyotaka Yada ◽  
Hiroaki Shimokawa ◽  
Osamu Hiramatsu ◽  
Yoshisuke Haruna ◽  
Yoshitaka Morita ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Myocardial Infarct ◽  
Ischemia Reperfusion ◽  
Protective Role ◽  
No Production ◽  
Coronary Vasodilatation ◽  
Before And After ◽  
Nos Inhibitor

We have recently demonstrated that endogenous H2O2 plays an important role in coronary autoregulation in vivo. However, the role of H2O2 during coronary ischemia-reperfusion (I/R) injury remains to be examined. In this study, we examined whether endogenous H2O2 also plays a protective role in coronary I/R injury in dogs in vivo. Canine subepicardial small coronary arteries (≥100 μm) and arterioles (<100 μm) were continuously observed by an intravital microscope during coronary I/R (90/60 min) under cyclooxygenase blockade ( n = 50). Coronary vascular responses to endothelium-dependent vasodilators (ACh) were examined before and after I/R under the following seven conditions: control, nitric oxide (NO) synthase (NOS) inhibitor NG-monomethyl-l-arginine (l-NMMA), catalase (a decomposer of H2O2), 8-sulfophenyltheophylline (8-SPT, an adenosine receptor blocker), l-NMMA + catalase, l-NMMA + tetraethylammonium (TEA, an inhibitor of large-conductance Ca2+-sensitive potassium channels), and l-NMMA + catalase + 8-SPT. Coronary I/R significantly impaired the coronary vasodilatation to ACh in both sized arteries (both P < 0.01); l-NMMA reduced the small arterial vasodilatation (both P < 0.01), whereas it increased ( P < 0.05) the ACh-induced coronary arteriolar vasodilatation associated with fluorescent H2O2 production after I/R. Catalase increased the small arterial vasodilatation ( P < 0.01) associated with fluorescent NO production and increased endothelial NOS expression, whereas it decreased the arteriolar response after I/R ( P < 0.01). l-NMMA + catalase, l-NMMA + TEA, or l-NMMA + catalase + 8-SPT further decreased the coronary vasodilatation in both sized arteries (both, P < 0.01). l-NMMA + catalase, l-NMMA + TEA, and l-NMMA + catalase + 8-SPT significantly increased myocardial infarct area compared with the other four groups (control, l-NMMA, catalase, and 8-SPT; all, P < 0.01). These results indicate that endogenous H2O2, in cooperation with NO, plays an important cardioprotective role in coronary I/R injury in vivo.

scholarly journals P0511ENHANCER AND SUPER-ENHANCER DYNAMICS IN REPAIR AFTER ISCHEMIC ACUTE KIDNEY INJURY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Julia Wilflingseder ◽  
Michaela Willi ◽  
Hye Kyung Lee ◽  
Hannes Olauson ◽  
Jakub Jankowsky ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Transcription Factors ◽  
Small Molecule ◽  
Ischemia Reperfusion Injury ◽  
Specific Binding ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Kidney Cortex ◽  
Super Enhancer

Abstract Background and Aims The endogenous repair process of the mammalian kidney allows rapid recovery after acute kidney injury (AKI) through robust proliferation of tubular epithelial cells. There is currently limited understanding of which transcriptional regulators activate these repair programs and how transcriptional dysregulation leads to maladaptive repair. Here we investigate the existence of enhancer dynamics in the regenerating mouse kidney. Method RNA-seq and ChIP-seq (H3K27ac, H3K4m3, BRD4, POL2 and selected transcription factors) were performed on samples from repairing kidney cortex 2 days after ischemia/reperfusion injury (IRI) to identify activated genes, transcription factors, enhancer and super-enhancers associated with kidney repair. Further we investigated the role of super-enhancer activation in kidney repair through pharmacological BET inhibition using the small molecule JQ1 in vitro and in acute kidney injury models in vivo. Results Response to kidney injury leads to genome-wide alteration in enhancer repertoire in-vivo. We identified 16,781 enhancer sites (H3K27ac and BRD4 positive, H3K4me3 negative binding) active in SHAM and IRI samples; 6,512 lost and 9,774 gained after IRI. The lost and gained enhancer sites can be annotated to 62% and 63% of down- and up-regulated transcripts at day 2 after kidney injury, respectively. Super-enhancer analysis revealed 164 lost and 216 gained super-enhancer sites at IRI day 2. 385 super-enhancers maintain activity before and after injury. ChIP-seq profiles of selected transcription factors based on motif analysis show specific binding at corresponding enhancer sites. We observed lost enhancer binding of HNF4A and GR mainly at kidney related enhancer elements. In contrast, STAT3 showed increased binding at injury induces enhancer elements. No dynamic was observed for STAT5. Both transcription factor groups show corresponding mRNA changes after injury. Pharmacological inhibition of enhancer and super-enhancer activity by BRD4 inhibition (JQ1: 50mg/kg/day) before IRI leads to suppression of 40% of injury-induced transcripts associated with cell cycle regulation and significantly increased mortality between days 2 and 3 after AKI. Conclusion This is the first demonstration of enhancer and super-enhancer function in the repairing kidney. In addition, our data call attention to potential caveats for use of small molecule inhibitors of BET proteins that are currently being tested in clinical trials in cancer patients who are at risk for AKI. Our analyses of enhancer dynamics after kidney injury in vivo have the potential to identify new targets for therapeutic intervention.

scholarly journals Norswertianolin Promotes Cystathionine γ-Lyase Activity and Attenuates Renal Ischemia/Reperfusion Injury and Hypertension

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaping Niu ◽  
Congkuo Du ◽  
Changting Cui ◽  
Haizeng Zhang ◽  
Yue Deng ◽  
...  
Keyword(s):  
Cardiovascular Diseases ◽  
Small Molecule ◽  
Ischemia Reperfusion Injury ◽  
Specific Binding ◽  
Ischemia Reperfusion ◽  
Mrna Level ◽  
Protective Role ◽  
Spontaneously Hypertensive

Cystathionine gamma-lyase (CSE)/hydrogen sulfide (H2S) plays a protective role in cardiovascular diseases including hypertension and ischemia/reperfusion (I/R) injury. This study was aimed to screen natural small molecule compounds that activate CSE activity and then evaluate its effect(s) on kidney I/R injury and hypertension. Applying computer molecular docking technology, we screened the natural small molecule compound norswertianolin (NW)-specific binding to CSE. Using the microscale thermophoresis technology, we confirmed that the Leu68 site was the essential hydrogen bond site of NW binding to CSE. NW supplementation significantly increased CSE expression and its activity for H2S generation both in vivo and in vitro. In the model of acute and long-term kidney I/R injury, NW pretreatment dramatically attenuated kidney damage, associated with decreasing blood urea nitrogen (BUN), serum creatinine (Cr) level, reactive oxygen species (ROS) production, and cleaved caspase 3 expression. In spontaneously hypertensive rats (SHRs), NW treatment also lowered blood pressure, the media/lumen ratio of the femoral artery, and the mRNA level of inflammatory cytokines. In conclusion, NW acts as a novel small molecular chemical compound CSE agonist, directly binding to CSE, heightening CSE generation–H2S activity, and then alleviating kidney I/R injury and hypertension. NW has a potential therapeutic merit for cardiovascular diseases.

scholarly journals Ethyl Pyruvate Promotes Proliferation of Regulatory T Cells by Increasing Glycolysis

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4112
Author(s):  
Ivan Koprivica ◽  
Dragica Gajić ◽  
Nada Pejnović ◽  
Verica Paunović ◽  
Tamara Saksida ◽  
...  
Keyword(s):  
T Cells ◽  
Ischemia Reperfusion Injury ◽  
Ethyl Pyruvate ◽  
Ischemia Reperfusion ◽  
Acid Oxidation ◽  
Stable Form ◽  
Beneficial Effects ◽  
And Function

Ethyl pyruvate (EP), a stable form of pyruvate, has shown beneficial effects in animal models of shock, ischemia/reperfusion injury, and sepsis due to its potent anti-oxidant and anti-inflammatory properties. Our recent study demonstrated that EP application prevented the clinical manifestation of type 1 diabetes in mice by augmenting regulatory T cell (Treg) number and function. Our present study shows that EP increases Treg proliferation and suppressive function (perforin and IL-10 expression) during in vitro differentiation from conventional CD4+CD25− T cells. Enhanced expansion of Treg after EP treatment correlated with increased ATP levels and relied on increased glycolysis. Inhibition of oxidative phosphorylation did not attenuate EP stimulatory effects, suggesting that this metabolic pathway was not mandatory for EP-driven Treg proliferation. Moreover, EP lowered the expression of carnitine palmitoyltransferase I, an enzyme involved in fatty acid oxidation. Further, the stimulatory effect of EP on Treg proliferation was not mediated through inhibition of the mTOR signaling pathway. When given in vivo either intraperitoneally or orally to healthy C57BL/6 mice, EP increased the number of Treg within the peritoneal cavity or gut-associated lymphoid tissue, respectively. In conclusion, EP promotes in vitro Treg proliferation through increased glycolysis and enhances Treg proliferation when administered in vivo.

Aging attenuates the protective effect of ischemic preconditioning against endothelial ischemia-reperfusion injury in humans

2013 ◽  
Vol 304 (12) ◽  
pp. H1727-H1732 ◽  
Author(s):  
Inge van den Munckhof ◽  
Niels Riksen ◽  
Joost P. H. Seeger ◽  
Tim H. Schreuder ◽  
George F. Borm ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Ischemic Preconditioning ◽  
Brachial Artery ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
The Elderly ◽  
Upper Arm ◽  
Before And After ◽  
The Impact

Reperfusion is mandatory after ischemia but also triggers ischemia-reperfusion (I/R) injury. Ischemic preconditioning (IPC) can limit endothelial I/R injury. Nonetheless, translation of IPC to the clinical arena is often disappointing. Since application of IPC typically relates to older patients, efficacy of IPC may be attenuated with aging. Our objective was to examine the impact of advanced age on the ability of IPC to protect against endothelial dysfunction due to I/R injury. We included 15 healthy young (20–25 yr) and 15 older (68–77 yr) men. We examined brachial artery endothelial function using flow-mediated dilation (FMD) before and after arm I/R (induced by inflation of an upper-arm blood pressure cuff for 20 min and 15 min of reperfusion). In a randomized order, I/R was preceded by IPC or a control intervention consisting of three cycles of 5 min upper-arm cuff inflation to 220 or 20 mmHg, respectively. As a result, in young men, FMD decreased significantly after I/R (6.4 ± 2.7 to 4.4 ± 2.5%). This decrease was not present when I/R was preceded by IPC (5.9 ± 2.3 to 5.6 ± 2.5%). IPC-induced protection appeared to be significantly reduced in the elderly patients ( P = 0.04). Although FMD decreased after I/R in older men (3.5 ± 1.7 to 2.5 ± 1.0%), IPC could not prevent this (3.7 ± 2.1 to 2.2 ± 1.1%). In conclusion, this study is the first to observe in humans in vivo that older age is associated with an abolished effect of IPC to protect against endothelial dysfunction after I/R in the brachial artery. This provides a possible explanation for the problematic translation of strategies that reduce I/R injury from preclinical work to the clinical arena.

scholarly journals Reconstitution of Kidney Side Population Cells after Ischemia-Reperfusion Injury by Self-Proliferation and Bone Marrow-Derived Cell Homing

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Hongbao Liu ◽  
Weihui Liu ◽  
Shuibing Liu ◽  
Qiuhong Meng ◽  
Ning Zhang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Growth Factor ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Side Population ◽  
Ischemia Reperfusion ◽  
Cell Homing ◽  
Paracrine Actions

The aim of this study was to examine the contribution of side population (SP) cells from kidney and bone marrow for reconstitution of kidney SP pools after ischemia-reperfusion injury (IRI). The SP and non-SP cells in kidneys following IRI were isolated and serially assessed by fluorescence-activated cell sorting. The apoptosis, proliferation, phenotype, and paracrine actions of SP cells were evaluatedin vitroandin vivo. Results indicated that the SP cells from ischemic kidney were acutely depleted within one day following renal IRI and were progressively restored to baseline within 7 days after IRI, through both proliferation of remaining kidney SP cells and homing of bone marrow-derived cells to ischemic kidney. Either hypoxia or serum deprivation alone increased apoptosis of SP cells, and a combination of both further aggravated it. Furthermore, hypoxiain vivoandin vitroinduced the increase in the secretion of vascular endothelial growth factor, insulin-like growth factor 1, hepatocyte growth factor, and stromal cell-derived factor-1αin kidney SP but not non-SP cells. In summary, these results suggest that following renal IRI, kidney SP cells are acutely depleted and then progressively restored to baseline levels by both self-proliferation and extrarenal source, that is, bone marrow-derived cell homing.

scholarly journals N6-methyladenosine demethylase FTO impairs hepatic ischemia–reperfusion injury via inhibiting Drp1-mediated mitochondrial fragmentation

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ying Dong Du ◽  
Wen Yuan Guo ◽  
Cong Hui Han ◽  
Ying Wang ◽  
Xiao Song Chen ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fragmentation ◽  
Hepatic Ischemia ◽  
Adeno Associated Virus ◽  
Downstream Target ◽  
Hepatic Ischemia Reperfusion

AbstractDespite N6-methyladenosine (m6A) is functionally important in various biological processes, its role and the underlying regulatory mechanism in the liver remain largely unexplored. In the present study, we showed that fat mass and obesity-associated protein (FTO, an m6A demethylase) was involved in mitochondrial function during hepatic ischemia–reperfusion injury (HIRI). We found that the expression of m6A demethylase FTO was decreased during HIRI. In contrast, the level of m6A methylated RNA was enhanced. Adeno-associated virus-mediated liver-specific overexpression of FTO (AAV8-TBG-FTO) ameliorated the HIRI, repressed the elevated level of m6A methylated RNA, and alleviated liver oxidative stress and mitochondrial fragmentation in vivo and in vitro. Moreover, dynamin-related protein 1 (Drp1) was a downstream target of FTO in the progression of HIRI. FTO contributed to the hepatic protective effect via demethylating the mRNA of Drp1 and impairing the Drp1-mediated mitochondrial fragmentation. Collectively, our findings demonstrated the functional importance of FTO-dependent hepatic m6A methylation during HIRI and provided valuable insights into the therapeutic mechanisms of FTO.

scholarly journals Propofol attenuates lung ischemia/reperfusion injury though the involvement of the MALAT1/microRNA-144/GSK3β axis

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Jian-Ping Zhang ◽  
Wei-Jing Zhang ◽  
Miao Yang ◽  
Hua Fang
Keyword(s):  
Cell Apoptosis ◽  
Ischemia Reperfusion Injury ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Inflammatory Factors ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Loss Of Function

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.

scholarly journals LINGO-1 shRNA protects the brain against ischemia/reperfusion injury by inhibiting the activation of NF-κB and JAK2/STAT3

Human Cell ◽  
2021 ◽  
Author(s):  
Jiaying Zhu ◽  
Zhu Zhu ◽  
Yipin Ren ◽  
Yukang Dong ◽  
Yaqi Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Mice Model ◽  
Down Regulation

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.

Sign in / Sign up

Export Citation Format

Share Document