Abstract 407: Modulation of Delta-Like Ligand-4 Signaling Improves Myocardial Revascularization Following Coronary Ischemia

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
S R Kumar ◽  
Christopher Yi ◽  
Timothy Martens ◽  
Sydney J Zagger ◽  
Antonio Duarte ◽  
...  

Delta-like ligand-4 (DLL4) is an arterial-specific Notch ligand and balanced signaling by DLL4 is required for functional neovascularization. We hypothesized that modest inhibition of DLL4 signaling improves myocardial revascularization following coronary ischemia. Myocardial infarction was induced by ligation of mid-left anterior descending (LAD) artery via rapid left thoracotomy in 6-8 week-old male mice with inducible endothelial-specific knockout or overexpression of DLL4. DLL4 silencing in homozygous mice on the day of or 5 days prior to LAD ligation resulted in significant reduction in revascularization. At four weeks, explanted hearts showed 1.8-fold fewer vessels in LAD territory, 3-fold greater myocardial hypoxia, 1.7-fold larger fibrotic scar and 17% increased perfusion defect in the left ventricle (LV) by scintigraphy. CT angiography confirmed fewer collateral vessels. Echocardiography showed increased LV dilation (37% higher end-diastolic volume) and 12% greater reduction in ejection fraction (EF) compared to baseline (all p<0.001). Overexpression of DLL4 showed a similarly worse outcome. Conversely, partial DLL4 knockout in heterozygous animals resulted in improved outcomes in all parameters. For translational application, animals were systemically administered 1.5mg/kg or 3mg/kg DLL4-Fc intraperitoneally three times a week beginning the day of ligation. RT-PCR analysis of downstream molecules confirmed that systemic DLL4-Fc partially inhibits Notch signaling in endothelial cells in the ischemic LV. When LAD was ligated very proximally, DLL4-Fc improved survival. With mid-LAD ligation, DLL4-Fc induced a dose-dependent increase in number of CD 31-positive vessels and by CT angiography. There was a dose-dependent reduction in hypoxic myocardial area, scar burden, and scintigraphic perfusion defect. DLL4-Fc treated mice had lower end-diastolic LV volume and preserved or improved EF. In an ischemia-reperfusion model, DLL4-Fc increased the number of vessels in the ischemic zone. Our data suggests that balanced DLL4 signaling is crucially required for myocardial angiogenic recovery following coronary ischemia. Modulation of DLL4 signaling has translational therapeutic potential.

1993 ◽  
Vol 69 (02) ◽  
pp. 157-163 ◽  
Author(s):  
Irving Fox ◽  
Adrian Dawson ◽  
Peter Loynds ◽  
Jane Eisner ◽  
Kathleen Findlen ◽  
...  

SummaryHirulog™ (BG8967) is a direct thrombin inhibitor built by rational design using the protein hirudin as a model (Maraganore et al. [1990]; Biochemistry 29: 7095–101). In order to evaluate the therapeutic potential for hirulog in the management of thrombotic disease, the tolerability and anticoagulant activity of the agent were examined in a study of human volunteers.In a randomized, placebo-controlled study (n = 54), the intravenous infusion of hirulog over 15 min showed a rapid, dose-dependent prolongation of activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). There was a corresponding dose-dependent increase in plasma hirulog levels. The peptide was rapidly cleared with a half-life of 36 min and a total body clearance rate for the peptide of 0.43 1 kg−1 h−1. Similar activity was observed following subcutaneous injection but with sustained pharmacodynamic and pharmacokinetic behavior. There was a significant correlation between pharmacokinetic and pharmacodynamic variables for both intravenous (r = 0.8, p <0.001) and subcutaneous administration (r = 0.7, p = 0.002).To evaluate the possible interactions of aspirin on the tolerability and anticoagulant activity of intravenous hirulog, a cross-over design was employed in eight subjects. Aspirin administration did not modify the peptide’s activity. At the administered dose of 0.6 mg kg−1 h−1 for 2 h, hirulog infusion prolonged APTT from 230 to 260% baseline. The infusion of hirulog in subjects who had received aspirin was not associated with any significant changes in the template bleeding time.The final phase of the study examined the activity and tolerability of hirulog in ten subjects during prolonged intravenous infusions for up to 24 h. The peptide (0.3 mg kg−1 h−1) exhibited sustained anticoagulant activity with no evidence for a cumulative effect. During hirulog infusion, APTT was prolonged from 210 to 250% baseline.In all phases of the study, hirulog administration was generally well-tolerated.Our observations show that hirulog is an active antithrombin agent with excellent tolerability in humans. As a direct thrombin inhibitor, hirulog provides a novel approach for the management of thrombotic disease.


Author(s):  
Saniya Hashim Khan ◽  
Sheraz Khan ◽  
Inamullah Khan ◽  
Narmeen Hashim

Background: Chronic stress elevates the cortisol beyond normal levels, which affects cognition including learning & memory. This injurious effect is primarily mediated via over excitation of metabotropic glucocorticoid receptors (mGR). Methods: The present study was aimed appraise the neuroprotective effects of naturally occurring molecule β-1,3-glucan by interfering with stress-cortisol-mGR axis. Our data of virtual screening (in silico) exhibited the promising interactions of βglucan with the mGR. Therefore, the study was extended to evaluate its efficacy (2.5, 5 and 10 mg/kg/ i.p) in an animal model of chronic unpredictable mild stress (CUMS, 28 days) induced memory impairment. Results: Results of the current study revealed the β-glucan provided dose dependent protection against deleterious effects of stress on learning and memory associated parameters observed in Morris water maze (MWM) task. At higher tested doses, it has also significantly antagonized the stress induced weight loss and corticosterone elevation. Conclusion: From these findings, it can be deduced that the β-glucan possesses therapeutic potential against stress induced memory impairment, and this effect can be attributed to its normalizing effect on corticosterone levels.


2021 ◽  
pp. 039139882098680
Author(s):  
Xuefeng Zhang ◽  
Nan Wang ◽  
Yuhua Huang ◽  
Yan Li ◽  
Gang Li ◽  
...  

Background: Three-dimensional (3D) culture has been reported to increase the therapeutic potential of mesenchymal stem cells (MSCs). The present study assessed the therapeutic efficacy of extracellular vesicles (EVs) from 3D cultures of human placental MSCs (hPMSCs) for acute kidney injury (AKI). Methods: The supernatants from monolayer culture (2D) and 3D culture of hPMSCs were ultra-centrifuged for EVs isolation. C57BL/6 male mice were submitted to 45 min bilateral ischemia of kidney, followed by renal intra-capsular administration of EVs within a 72 h reperfusion period. Histological, immunohistochemical, and ELISA analyses of kidney samples were performed to evaluate cell death and inflammation. Kidney function was evaluated by measuring serum creatinine and urea nitrogen. The miRNA expression profiles of EVs from 2D and 3D culture of hPMSCs were evaluated using miRNA microarray analysis. Results: The 3D culture of hPMSCs formed spheroids with different diameters depending on the cell density seeded. The hPMSCs produced significantly more EVs in 3D culture than in 2D culture. More importantly, injection of EVs from 3D culture of hPMSCs into mouse kidney with ischemia-reperfusion (I/R)-AKI was more beneficial in protecting from progression of I/R than those from 2D culture. The EVs from 3D culture of hPMSCs were more efficient against apoptosis and inflammation than those from 2D culture, which resulted in a reduction in tissue damage and amelioration of renal function. MicroRNA profiling analysis revealed that a set of microRNAs were significantly changed in EVs from 3D culture of hPMSCs, especially miR-93-5p. Conclusion: The EVs from 3D culture of hPMSCs have therapeutic potential for I/R-AKI.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Hui Liu ◽  
Chang Chun Ling ◽  
Wai Ho Oscar Yeung ◽  
Li Pang ◽  
Jiang Liu ◽  
...  

AbstractTumor recurrence is the major obstacle for pushing the envelope of liver transplantation for hepatocellular carcinoma (HCC) patients. The inflammatory cascades activated by acute liver graft injury promote tumor recurrence. We aimed to explore the role and mechanism of myeloid-derived suppressor cell (MDSC) mobilization induced by liver graft injury on tumor recurrence. By analyzing 331 HCC patients who received liver transplantation, the patients with graft weight ratio (GWR, the weight of liver graft divided by the estimated standard liver weight of recipient) <60% had higher tumor recurrence than GWR ≥60% ones. MDSCs and CXCL10/TLR4 levels were significantly increased in patients with GWR <60% or tumor recurrence. These findings were further validated in our rat orthotopic liver transplantation model. In CXCL10−/− and TLR4−/− mice of hepatic ischemia/reperfusion injury plus major hepatectomy (IRH) model, monocytic MDSCs, instead of granulocytic MDSCs, were significantly decreased. Importantly, CXCL10 deficiency reduced the accumulation of TLR4+ monocytic MDSCs, and CXCL10 increased MDSC mobilization in the presence of TLR4. Moreover, MMP14 was identified as the key molecule bridging CXCL10/TLR4 signaling and MDSC mobilization. Knockout or inhibition of CXCL10/TLR4 signaling significantly reduced the tumor growth with decreased monocytic MDSCs and MMP14 in the mouse tumor recurrent model. Our data indicated that monocytic MDSCs were mobilized and recruited to liver graft during acute phase injury, and to promote HCC recurrence after transplantation. Targeting MDSC mobilization via CXCL10/TLR4/MMP14 signaling may represent the therapeutic potential in decreasing post-transplant liver tumor recurrence.


2007 ◽  
Vol 293 (2) ◽  
pp. H1254-H1264 ◽  
Author(s):  
Taku Yamamoto ◽  
Takeshi Shirayama ◽  
Tomohiko Sakatani ◽  
Tomosaburo Takahashi ◽  
Hideo Tanaka ◽  
...  

The Na+-HCO3− cotransporter (NBC) plays a key role in intracellular pH (pHi) regulation in normal ventricular muscle. However, the state of NBC in nonischemic hypertrophied hearts is unresolved. In this study, we examined functional and molecular properties of NBC in adult rat ventricular myocytes. The cells were enzymatically isolated from both normal and hypertrophied hearts. Ventricular hypertrophy was induced by pressure overload created by suprarenal abdominal aortic constriction of 50% for 7 wk. pHi was measured in single cells using the fluorescent pH indicator 2′,7′-bis(2-carboxyethyl)5-( 6 )carboxyfluorescein. Real-time PCR analysis was used to quantitatively assess expression of NBC-encoding mRNA, including SLC4A4 (encoding electrogenic NBC, NBCe1) and SLC4A7 (electroneutral NBC, NBCn1). Our results demonstrate that: 1) mRNA levels of both the electrogenic NBCe1 (SLC4A4) and electroneutral NBCn1 (SLC4A7) forms of NBC were increased by aortic constriction, 2) the onset of NBC upregulation occurred within 3 days after constriction, 3) normal and hypertrophied ventricles displayed regional differences in NBC expression, 4) acid extrusion via NBC ( JNBC) was increased significantly in hypertrophied myocytes, 5) although acid extrusion via Na+/H+ exchange was also increased in hypertrophied myocytes, the relative enhancement of JNBC was larger, 6) membrane depolarization markedly increased JNBC in hypertrophied myocytes, and 7) losartan, an ANG II AT1 receptor antagonist, significantly attenuated the upregulation of both NBCs induced by 3 wk of aortic constriction. Enhanced NBC activity during hypertrophic development provides a mechanism for intracellular Na+ overload, which may render the ventricles more vulnerable to Ca2+ overload during ischemia-reperfusion.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Andrew Chandler ◽  
Meredith K. Bartelstein ◽  
Tomohiro Fujiwara ◽  
Cristina R. Antonescu ◽  
John H. Healey ◽  
...  

Abstract Background Giant cell tumor of bone is a benign, locally aggressive neoplasm. Surgical resection is the preferred treatment method. However, for cases in which resection poses an increased risk to the patient, denosumab (anti-RANKL monoclonal antibody) is considered. Secukinumab is an anti-IL-17 antibody that is used in psoriatic arthritis to reduce bone resorption and articular damage. Case presentation One case of giant cell tumor of bone (GCTB) in a patient treated with secukinumab for psoriatic arthritis demonstrated findings significant for intra-lesional calcifications. Histologic examination showed ossification, new bone formation, and remodeling. A paucity of osteoclast type giant cells was noted. Real-time quantitative polymerase-chain-reaction (qRT-PCR) analysis revealed decreased osteoclast function compared to treatment-naive GCTB. Conclusions Secukinumab may play a role in bone remodeling for GCTB. Radiologists, surgeons, and pathologists should be aware of this interaction, which can cause lesional ossification. Further research is required to define the therapeutic potential of this drug for GCTB and osteolytic disease.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Chandrakala Aluganti Narasimhulu ◽  
Kathryn Young Burge ◽  
Yu Yuan ◽  
Sampath Parthasarathy

Background: Alpha keto acids are unstable and decompose rapidly. In this study, we tested the ability of alpha keto acids to reduce peroxides and inhibit oxidation of lipoproteins. Methods: Keto salicylic acid (KSA) and Keto Octanoicacid (KoA) were synthesized and their ability to reduce hydrogen peroxides as well as lipid peroxides (LOOH) was measured using 13-hydroperoxyoctadecadienoic acid (13-HPODE). Lipoproteins (LDL and HDL) were isolated from human plasma and oxidation of liporproteins was performed using copper and MPO in the presence or absence of the keto compounds. RAW 264.7 cells and HUVECS were incubated with LPS and mm-LDL respectively either in the presence or absence of the keto compounds. RNA was isolated from treated cells and real time PCR was performed to analyze IL-1α, IL-6, MCP-1 and VCAM1 gene expressions. Reactive oxygen species were evaluated using DCF fluorescence in presence and absence of the keto compounds. Results: KSA reduced both H2O2 and 13-HPODE whereas KoA is able to reduce the former but not the latter. Both compounds inhibited the lipoprotein oxidation in a dose dependent manner and were able to reduce ROS production by H2O2. KSA is able to inhibit both LPS as well as mm-LDL induced inflammation. However, KoA showed a dual effect as it induced inflammatory markers in the presence of LPS, but inhibited the mm-LDL-induced inflammatory gene expressions. Conclusion: The results of our studies suggest that these keto compounds a) inhibit both enzymatic and non enzymatic oxidation of lipoproteins; b) reduce peroxides and ROS and c) have inhibitory and inducing effect on inflammatory cytokine/gene production in presence of mm-LDL and LPS respectively. Based on these results, we predict that these keto compounds could have therapeutic potential in reducing CVD/atherosclerosis-associated inflammation.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Yaqi Shen ◽  
Zhuqing Shen ◽  
Shanshan Luo ◽  
Wei Guo ◽  
Yi Zhun Zhu

Hydrogen sulfide (H2S) is now recognized as a third gaseous mediator along with nitric oxide (NO) and carbon monoxide (CO), though it was originally considered as a malodorous and toxic gas. H2S is produced endogenously from cysteine by three enzymes in mammalian tissues. An increasing body of evidence suggests the involvement of H2S in different physiological and pathological processes. Recent studies have shown that H2S has the potential to protect the heart against myocardial infarction, arrhythmia, hypertrophy, fibrosis, ischemia-reperfusion injury, and heart failure. Some mechanisms, such as antioxidative action, preservation of mitochondrial function, reduction of apoptosis, anti-inflammatory responses, angiogenic actions, regulation of ion channel, and interaction with NO, could be responsible for the cardioprotective effect of H2S. Although several mechanisms have been identified, there is a need for further research to identify the specific molecular mechanism of cardioprotection in different cardiac diseases. Therefore, insight into the molecular mechanisms underlying H2S action in the heart may promote the understanding of pathophysiology of cardiac diseases and lead to new therapeutic targets based on modulation of H2S production.


2021 ◽  
Vol 22 (21) ◽  
pp. 11967
Author(s):  
Songhyun Lim ◽  
Tae Jung Kim ◽  
Young-Ju Kim ◽  
Cheesue Kim ◽  
Sang-Bae Ko ◽  
...  

Ischemic stroke is one of the leading causes of death, and even timely treatment can result in severe disabilities. Reperfusion of the ischemic stroke region and restoration of the blood supply often lead to a series of cellular and biochemical consequences, including generation of reactive oxygen species (ROS), expression of inflammatory cytokines, inflammation, and cerebral cell damage, which is collectively called cerebral ischemia-reperfusion (IR) injury. Since ROS and inflammatory cytokines are involved in cerebral IR injury, injury could involve cellular senescence. Thus, we investigated whether senolytic therapy that eliminates senescent cells could be an effective treatment for cerebral IR injury. To determine whether IR induces neural cell senescence in vitro, astrocytes were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). OGD/R induced astrocyte senescence and senescent cells in OGD/R-injured astrocytes were effectively eliminated in vitro by ABT263, a senolytic agent. IR in rats with intraluminal middle cerebral artery occlusion induced cellular senescence in the ischemic region. The senescent cells in IR-injured rats were effectively eliminated by intravenous injections of ABT263. Importantly, ABT263 treatment significantly reduced the infarct volume and improved neurological function in behavioral tests. This study demonstrated, for the first time, that senolytic therapy has therapeutic potential for cerebral IR injury.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9438
Author(s):  
Eduardo Cienfuegos-Pecina ◽  
Tannya R. Ibarra-Rivera ◽  
Alma L. Saucedo ◽  
Luis A. Ramírez-Martínez ◽  
Deanna Esquivel-Figueroa ◽  
...  

Background Ischemia–reperfusion (IR) injury is the main cause of delayed graft function in solid organ transplantation. Hypoxia-inducible factors (HIFs) control the expression of genes related to preconditioning against IR injury. During normoxia, HIF-α subunits are marked for degradation by the egg-laying defective nine homolog (EGLN) family of prolyl-4-hydroxylases. The inhibition of EGLN stabilizes HIFs and protects against IR injury. The aim of this study was to determine whether the EGLN inhibitors sodium (S)-2-hydroxyglutarate [(S)-2HG] and succinic acid (SA) have a nephroprotective effect against renal IR injury in Wistar rats. Methods (S)-2HG was synthesized in a 22.96% yield from commercially available L-glutamic acid in a two-step methodology (diazotization/alkaline hydrolysis), and its structure was confirmed by nuclear magnetic resonance and polarimetry. SA was acquired commercially. (S)-2HG and SA were independently evaluated in male and female Wistar rats respectively after renal IR injury. Rats were divided into the following groups: sham (SH), nontoxicity [(S)-2HG: 12.5 or 25 mg/kg; SA: 12.5, 25, or 50 mg/kg], IR, and compound+IR [(S)-2HG: 12.5 or 25 mg/kg; SA: 12.5, 25, or 50 mg/kg]; independent SH and IR groups were used for each assessed compound. Markers of kidney injury (BUN, creatinine, glucose, and uric acid) and liver function (ALT, AST, ALP, LDH, serum proteins, and albumin), proinflammatory cytokines (IL-1β, IL-6, and TNF-α), oxidative stress biomarkers (malondialdehyde and superoxide dismutase), and histological parameters (tubular necrosis, acidophilic casts, and vascular congestion) were assessed. Tissue HIF-1α was measured by ELISA and Western blot, and the expression of Hmox1 was assessed by RT-qPCR. Results (S)-2HG had a dose-dependent nephroprotective effect, as evidenced by a significant reduction in the changes in the BUN, creatinine, ALP, AST, and LDH levels compared with the IR group. Tissue HIF-1α was only increased in the IR group compared to SH; however, (S)-2HG caused a significant increase in the expression of Hmox1, suggesting an early accumulation of HIF-1α in the (S)-2HG-treated groups. There were no significant effects on the other biomarkers. SA did not show a nephroprotective effect; the only changes were a decrease in creatinine level at 12.5 mg/kg and increased IR injury at 50 mg/kg. There were no effects on the other biochemical, proinflammatory, or oxidative stress biomarkers. Conclusion None of the compounds were hepatotoxic at the tested doses. (S)-2HG showed a dose-dependent nephroprotective effect at the evaluated doses, which involved an increase in the expression of Hmox1, suggesting stabilization of HIF-1α. SA did not show a nephroprotective effect but tended to increase IR injury when given at high doses.


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