Neutrophils from NOD (Non‐Obese Diabetic) mice exhibited reduced migration speed, decreased frequency of directional changes, and loss of directionality during chemotaxis (compared to wild‐type [WT] C57BL/6 mice). Additionally, F‐actin of chemotaxing NOD neutrophils failed to orient toward the chemoattractant gradient and NOD neutrophil adhesion was impaired. A point mutation near the autophosphorylation site of Lyn in NOD mice was identified. Point mutations of G to A (G1412 in LynA and G1199 in LynB) cause a change of amino acid E393 (glutamic acid) to K (lysine) in LynA (E393→K) (E372 of LynB), affecting fMLP‐induced tyrosine phosphorylation. These data indicate that the Lyn mutation in NOD neutrophils is likely responsible for dysregulation of neutrophil adhesion and directed migration, implying the role of Lyn in modulating diabetic patient's susceptibility to bacterial and fungal infections. J. Cell. Physiol. 232: 1689–1695, 2017. © 2016 Wiley Periodicals, Inc.
The key oxygen sensing molecules, Prolyl-hydroxylase domain 1-3 enzymes (PHD1-3), regulate hypoxia-inducible factor (HIF) under hypoxia. In the settings of cardiomyopathy and ischemia-reperfusion injury, PHD3 expression is elevated, resulting in decreased HIF activation. The role of PHD3 in myocardial injury is poorly understood. Hence, we aimed to determine the effects of PHD3 deletion in mice on HIF-1α and other related pathways following myocardial infarction (MI). Left coronary artery (LAD) in both wild type and prolyl hydroxylase 3 knock out (PHD3⁻/⁻) mice was ligated to induce myocardial infarction. Electrophoretic mobility shift analysis showed significant increase in DNA-binding activity of HIF-1α in PHD3⁻/⁻ mice as compared to wild type (WT) mice post MI. The PHD3⁻/⁻MI group also showed decreased fibrosis. Seven days after MI, enhanced capillary/arteriolar density was observed compared to WTMI group. PHD3⁻/⁻ mice subjected to MI also showed improved cardiac functions (Ejection fraction and Fractional shortening), as assessed by echocardiogram, compared to WT. Western blot analysis showed increased VEGF, Ang-1 & Bcl-2 expression in PHD3⁻/⁻MI group. In conclusion, ablation of the PHD3 gene resulted in increased angiogenesis and cardiac function after infarction thereby offering a potential target for pharmacological management of ischemic myocardial disease.
Oligonol (OLG), derived from lychee fruit, is a novel compound produced from the oligomerization of polyphenols. In this study, the acute effect of OLG treatment was investigated on heart, liver and kidney in rats. OLG treatment at two different doses (15 or 30 mg/kg body weight) and two different time points (1 day or 7 days of treatment) demonstrated that no toxic effects were observed on heart, liver and renal functions. Moreover, OLG did not induce any DNA damage or oxidative stress as measured by 8-hydroxy-2'-deoxyguanosine levels in plasma. OLG supplementation increased the phosphorylation of myocardial endothelial nitric oxide (NO) level (p-eNOS) in both the treatment groups. Even the low dose OLG treatment (15 mg/kg b.w) demonstrated an increase in p-eNOS/eNOS ratio after normalization of p-eNOS values with eNOS on day 1 (1.5-fold) and day 7 (2.2-fold) groups as compared to control. The above results suggest that OLG treatment increases endothelial NO levels and may play a role in NO-mediated vasodilatory effects without adverse side effects on cardiovascular function. This endothelial NO production may underlie the beneficial effect of OLG in cardiovascular health.
Several potential sources of reactive oxygen species (ROS) in cells exist. One source is NADPH oxidase, which is especially important for superoxide radical production. Nox2 is a primary regulatory subunit of NADPH oxidase. In the present study, we examined the role of ROS and NADPH oxidase in ischemic preconditioning (IP)-mediated cardioprotection by using Nox2−/− mice. Both wild-type (WT) and Nox2−/− mice were subjected to either 30 min of ischemia followed by 2 h of reperfusion (IR) or IP prior to 30 min ischemia and 2 h of reperfusion. Reduction in left ventricular developed pressure (60.1 versus 63 mmHg), dp/dt max (893 versus 1,027 mmHg/s), and aortic flow (0.9 versus 1.8 ml/min) was observed in Nox2−/−IPIR compared to WTIPIR along with increased infarct size (33% versus 22%) and apoptosis after 120 min of reperfusion. Differentially regulated genes were demonstrated by comparing gene expression in WTIPIR versus Nox2−/− IPIR hearts. Selected differentially regulated genes such as β-catenin, SRPK3, ERDR1, ACIN1, Syntaxin-8, and STC1 were validated by real-time PCR. Taken together, this is the first report identifying important, differentially expressed genes during ischemic preconditioning in Nox2−/− mice by using microarray analysis.
Oxidative stress plays a critical role in the pathophysiology of cardiac failure, including the modulation of neovascularization following myocardial infarction (MI). Redox molecules thioredoxin (Trx) and glutaredoxin (Grx) superfamilies actively maintain intracellular thiol-redox homeostasis by scavenging reactive oxygen species. Among these two superfamilies, the pro-angiogenic function of Trx-1 has been reported in chronic MI model whereas similar role of Grx-1 remains uncertain. The present study attempts to establish the role of Grx-1 in neovascularization and ventricular remodeling following MI. Wild-type (WT) and Grx-1 transgenic (Grx-1(Tg/+)) mice were randomized into wild-type sham (WTS), Grx-1(Tg/+) Sham (Grx-1(Tg/+)S), WTMI, Grx-1(Tg/+)MI. MI was induced by permanent occlusion of the LAD coronary artery. Sham groups underwent identical time-matched surgical procedures without LAD ligation. Significant increase in arteriolar density was observed 7 days (d) after surgical intervention in the Grx-1(Tg/+)MI group as compared to the WTMI animals. Further, improvement in myocardial functional parameters 30 d after MI was observed including decreased LVIDs, LVIDd, increased ejection fraction and, fractional shortening was also observed in the Grx-1(Tg/+)MI group as compared to the WTMI animals. Moreover, attenuation of oxidative stress and apoptotic cardiomyocytes was observed in the Grx-1(Tg/+)MI group as compared to the WTMI animals. Increased expression of p-Akt, VEGF, Ang-1, Bcl-2, survivin and DNA binding activity of NF-κB were observed in the Grx-1(Tg/+)MI group when compared to WTMI animals as revealed by Western blot analysis and Gel-shift analysis, respectively. These results are the first to demonstrate that Grx-1 induces angiogenesis and diminishes ventricular remodeling apparently through neovascularization mediated by Akt, VEGF, Ang-1 and NF-κB as well as Bcl-2 and survivin-mediated anti-apoptotic pathway in the infarcted myocardium.
Hypoxia-inducible factor (HIF)-prolylhydroxylases (PHDs) are oxygen sensors that regulate the stability of HIF in an oxygen-dependent manner thus mediating cellular adaptive responses to changes in...
Oxidative stress plays a crucial role in disruption of neovascularization by alterations in thioredoxin 1 (Trx1) expression and its interaction with other proteins after myocardial infarction (MI). We previously showed that Trx1 has angiogenic properties, but the possible therapeutic significance of overexpressing Trx1 in chronic MI has not been elucidated. Therefore, we explored the angiogenic and cardioprotective potential of Trx1 in an in vivo MI model using transgenic mice overexpressing Trx1. Wild-type (W) and Trx1 transgenic (Trx1Tg/+) mice were randomized into W sham (WS), Trx1Tg/+ sham (TS), WMI, and TMI. MI was induced by permanent occlusion of LAD coronary artery. Hearts from mice overexpressing Trx1 exhibited reduced fibrosis and oxidative stress and attenuated cardiomyocyte apoptosis along with increased vessel formation compared to WMI. We found significant inhibition of Trx1 regulating proteins, TXNIP and AKAP 12, and increased p-Akt, p-eNOS, p-GSK-3β, HIF-1α, β-catenin, VEGF, Bcl-2, and survivin expression in TMI compared to WMI. Echocardiography performed 30days after MI revealed significant improvement in myocardial functions in TMI compared to WMI. Our study identifies a potential role for Trx1 overexpression and its association with its regulatory proteins TXNIP, AKAP12, and subsequent activation of Akt/GSK-3β/β-catenin/HIF-1α-mediated VEGF and eNOS expression in inducing angiogenesis and reduced ventricular remodeling. Hence, Trx1 and other proteins identified in our study may prove to be potential therapeutic targets in the treatment of ischemic heart disease.
Statins (HMG-CoA reductase inhibitors), are known to improve cardiac function in diabetes-induced cardiovascular disease as a result of their antioxidant capacities. Oxidative stress plays a key ro...
Circumstantial evidence frequently implicates oxygen-derived free radicals and oxidative stress as mediators of myocardial ischemia/reperfusion (I/R) injury. Therefore, external supplementation of natural antioxidants plays a main role as cardioprotective compounds. This study was designed to evaluate the cardioprotective effect of VitaePro (70 mg/kg body weight, 21 days), a novel antioxidant mix of astaxanthin, lutein and zeaxanthin in a rat ex vivo model of ischemia/reperfusion injury. The cardioprotective effect of VitaePro was also compared with vitamin E (70 mg/kg body weight, 21 days) treatment. Rats were randomized into control I/R (CIR), VitaePro I/R (VPIR) and Vitamin E I/R (VEIR). After 21 days of oral treatment, isolated hearts from each group were subjected to 30 min of ischemia followed by 2 h of reperfusion. In the VPIR group compared to CIR and VEIR groups at 2 h of reperfusion, increased left ventricular functional recovery, such as left ventricular developed pressure (92.7 ± 0.7 vs. 85.3 ± 0.3 and 89.4 ± 1.2 mm Hg), dp/dt max (2518.7 ± 77.9 vs. 1962.5 ± 24 and 2255.7 ± 126.6 mm Hg/s), and aortic flow (21.5 ± 1.36 vs. 4.4 ± 0.6 and 13.2 ± 1.02 ml/min) were observed. The infarct size (27.68 ± 1.7 vs. 45.4 ± 1.8 and 35.4 ± 0.6%), apoptotic cardiomyocytes (61.7 ± 10.6 vs. 194.1 ± 14.8 and 118.7 ± 15.4 counts/100 HPF) and thiobarbituric acid reactive substances levels (80 ± 3 vs. 127 ± 5 and 103 ± 2 nM/mg tissue) also were decreased in VPIR group when compared to CIR and VEIR. As evidenced by the data, administration of vitamin E offered substantial cardioprotection to I/R injury, but VitaePro enhanced cardioprotection significantly more than vitamin E treatment. Taken in concert, the results of this study suggests that the oral ingestion of VitaePro protects myocardium from ischemia/reperfusion injury by decreasing oxidative stress and apoptosis, which may be of therapeutic benefit in the treatment of cardiovascular complications. However, further in vivo animal and human intervention studies are warranted before establishing any recommendations about usage of VitaePro for human cardiovascular complications.
Oriowo, Babatunde MD; Thirunavukkarasu, Mahesh PhD; Adluri, Sudheer PhD; Zhan, Lijun BSc; Takeda, Kotaro MD; Fong, Guo-Hua PhD; Sanchez, Juan A. MD; Maulik, Nilanjana PhD Author Information
Background— The present study evaluated the reversal of diabetes-mediated impairment of angiogenesis in a myocardial infarction model of type 1 diabetic rats by intramyocardial administration of an adenoviral vector encoding thioredoxin-1 ( Ad.Trx1 ). Various studies have linked diabetes-mediated impairment of angiogenesis to dysfunctional antioxidant systems in which thioredoxin-1 plays a central role. Methods and Results— Ad.Trx1 was administered intramyocardially in nondiabetic and diabetic rats immediately after myocardial infarction. Ad.LacZ was similarly administered to the respective control groups. The hearts were excised for molecular and immunohistochemical analysis at predetermined time points. Myocardial function was measured by echocardiography 30 days after the intervention. The Ad.Trx1 -administered group exhibited reduced fibrosis, oxidative stress, and cardiomyocyte and endothelial cell apoptosis compared with the diabetic myocardial infarction group, along with increased capillary and arteriolar density. Western blot and immunohistochemical analysis demonstrated myocardial overexpression of thioredoxin-1, heme oxygenase-1, vascular endothelial growth factor, and p38 mitogen-activated protein kinase-β, as well as decreased phosphorylated JNK and p38 mitogen-activated protein kinase-α, in the Ad.Trx1 -treated diabetic group. Conversely, we observed a significant reduction in the expression of vascular endothelial growth factor in nondiabetic and diabetic animals treated with tin protoporphyrin (SnPP, a heme oxygenase-1 enzyme inhibitor), even after Ad.Trx1 therapy. Echocardiographic analysis after 4 weeks of myocardial infarction revealed significant improvement in myocardial functional parameters such as ejection fraction, fractional shortening, and E/A ratio in the Ad.Trx1 -administered group compared with the diabetic myocardial infarction group. Conclusions— This study demonstrates for the first time that impairment of angiogenesis and myocardial dysfunction can be regulated by Ad.Trx1 gene therapy in streptozotocin-induced diabetic rats subjected to infarction.
Calcium is an essential mineral to support bone health and serves as a major therapeutic intervention to prevent and delay the incidence of osteoporosis. Many individuals do not obtain the optimum amount of calcium from diets and depend on bioavailable calcium supplements. The present study was conducted to examine the effect of a novel plant-based calcium supplement, derived from marine algae, and contains high levels of calcium, magnesium, and other bone supporting minerals [commercially known as AlgaeCal (AC)], on proliferation, mineralization, and oxidative stress in cultured human osteoblast cells, and compared with inorganic calcium carbonate and calcium citrate salts. Cultured human fetal osteoblast cells (hFOB 1.19) were treated with AC (0.5 mg/ml, fixed by MTT assay), calcium carbonate, or calcium citrate. These cells were harvested after 4 days of treatment for ALP activity, PCNA expression, and DNA synthesis, and 2 days for Ca(2+) deposition in the presence and absence of vitamin D3 (5 nM). The ability of AC to reduce H(2)O(2) (0.3 mM)-induced oxidative stress was assessed after 24 h of treatment. ALP activity was significantly increased with AC treatment when compared to control, calcium carbonate, or calcium citrate (4.0-, 2.0-, and 2.5-fold, respectively). PCNA expression (immunocytochemical analysis), DNA synthesis (4.0-, 3.0-, and 4.0-fold, respectively), and Ca(2+) deposition (2.0-, 1.0-, and 4.0-fold, respectively) were significantly increased in AC-treated cells when compared with control, calcium carbonate, or calcium citrate treatment. These markers were further enhanced following additional supplementation of vitamin D3 in the AC-treated group cells. AC treatment significantly reduced the H(2)O(2)-induced oxidative stress when compared to calcium carbonate or calcium citrate (1.5- and 1.4-fold, respectively). These findings suggest that AC may serve as a superior calcium supplement as compared to other calcium salts tested in the present study. Hence, AC may be developed as a novel anti-osteoporotic supplement in the near future.
OBJECTIVE Hyperglycemia impairs angiogenesis in response to ischemia, leading to ventricular remodeling. Although the effects of overexpressing angiogenic growth factors have been studied in inducing angiogenesis, the formation of functional vessels remains a challenge. The present study evaluates the reversal of diabetes-mediated impairment of angiogenesis in the infarcted diabetic rat myocardium by proangiogenic gene therapy. RESEARCH DESIGN AND METHODS Ad.VEGF and Ad.Ang1 were intramyocardially administered in combination immediately after myocardial infarction to nondiabetic and diabetic rats. Ad.LacZ was similarly administered to the respective control groups. The hearts were excised for molecular and immunohistochemical analysis at predetermined time points. The myocardial function was measured by echocardiography 30 days after the intervention. RESULTS We observed reduced fibrosis and increased capillary/arteriolar density along with reduced ventricular remodeling, as assessed by echocardiography in the treated diabetic animals compared with the nontreated diabetic controls. We also observed increased phosphorylated mitogen-activated protein kinase–activated protein kinase-2, 2 days after the treatment and increased expression of vascular endothelial growth factor (VEGF), Flk-1, angiopoietin-1 (Ang-1), Tie-2, and survivin, 4 days after treatment in the diabetic animals. Gel shift analysis revealed that the combination gene therapy stimulated the DNA binding activity of nuclear factor-κB in the diabetic animals. CONCLUSIONS Our preclinical data demonstrate the efficacy of coadministration of adenoviral VEGF and Ang-1 in increasing angiogenesis and reducing ventricular remodeling in the infarcted diabetic myocardium. These unique results call for the initiation of a clinical trial to assess the efficacy of this therapeutic strategy in the treatment of diabetes-related human heart failure.
Hypoxia-inducible transcription factor (HIF)-prolyl hydroxylases domain (PHD-1-3) are oxygen sensors that regulate the stability of the HIFs in an oxygen-dependent manner. Suppression of PHD enzymes leads to stabilization of HIFs and offers a potential treatment option for many ischemic disorders, such as peripheral artery occlusive disease, myocardial infarction, and stroke. Here, we show that homozygous disruption of PHD-1 (PHD-1(-/-)) could facilitate HIF-1 alpha-mediated cardioprotection in ischemia/reperfused (I/R) myocardium. Wild-type (WT) and PHD-1(-/-) mice were randomized into WT time-matched control (TMC), PHD-1(-/-) TMC (PHD1TMC), WT I/R, and PHD-1(-/-) I/R (PHD1IR). Isolated hearts from each group were subjected to 30 min of global ischemia followed by 2h of reperfusion. TMC hearts were perfused for 2h 30 min without ischemia. Decreased infarct size (35% +/- 0.6% vs. 49% +/- 0.4%) and apoptotic cardiomyocytes (106 +/- 13 vs. 233 +/- 21 counts/100 high-power field) were observed in PHD1IR compared to wild-type ischemia/reperfusion (WTIR). Protein expression of HIF-1 alpha was significantly increased in PHD1IR compared to WTIR. mRNA expression of beta-catenin (1.9-fold), endothelial nitric oxide synthase (1.9-fold), p65 (1.9-fold), and Bcl-2 (2.7-fold) were upregulated in the PHD1IR compared withWTIR, which was studied by real-time quantitative polymerase chain reaction. Further, gel-shift analysis showed increased DNA binding activity of HIF-1 alpha and nuclear factor-kappaB in PHD1IR compared to WTIR. In addition, nuclear translocation of beta-catenin was increased in PHD1IR compared with WTIR. These findings indicated that silencing of PHD-1 attenuates myocardial I/R injury probably by enhancing HIF-1 alpha/beta-catenin/endothelial nitric oxide synthase/nuclear factor-kappaB and Bcl-2 signaling pathway. Antioxid. Redox Signal. 15, 1789-1797.
Oxidative stress & alterations in thioredoxin-1 (Trx1) expression/activity & its interactions with several other proteins play a crucial role in cardiovascular complications after acute myocardial infarction (MI). Apart from its antioxidative capacity, Trx1 is known to possess antiapoptotic, growth stimulatory & angiogenic properties by modulating the expression/activity of its protein interacting partners thereby modifying the cell’s response to oxidative stress. However, the exact mechanism of the cardioprotective effect of overexpressing Trx1 has not been elucidated in acute MI. Therefore in the present study we have explored the angiogenic & cardioprotective potential of transgenic overexpression of Trx1 in mice in vivo MI model. The wild type (W) & the Trx1 transgenic (Tg+/+) mice were randomized into 4 groups: Wild type Sham (WS), WMI, Tg+/+ Sham (TS) Tg+/+ MI (TMI). MI was induced by permanent occlusion of LAD coronary artery. Sham groups underwent the same time matched surgical procedure without LAD ligation. We observed significant, reduction in infarct size (49±2vs35±2% infarct size/area at risk) & increase in capillary (2483±112vs3012±178) & arteriolar (15±0.9vs27±1) density (counts/mm2) with a consequent improvement in the myocardial functional parameters such as decreased LVIDs (3±0.2vs2.8±0.2) & increased ejection fraction (40. ±3vs53±3), & fractional shortening (19±2vs27±1) as assessed by echocardiography in the TMI compared to WMI. Immunoblot analysis revealed increased expression of Trx1 (6.2 fold), angiogenic VEGF (1.7 fold), anti-apoptotic survivin (2.4 fold) & Bcl2 (3.2 fold) in the TMI compared to WMI. Our study also identifies the potential of Trx1 overexpression in inducing angiogenesis probably via VEGF, reducing cell death & ventricular remodeling & a possible novel treatment strategy where Trx1 overexpression might alleviate oxidative stress & related human heart failure in several pathological conditions. The results obtained & the proteins identified in our current study may prove to be potential therapeutic targets in the treatment of ischemic heart diseases.
Bromelain (Br), an extract from pineapple stem with cysteine protease activity, exerts anti-inflammatory effects in a number of inflammatory models. We have previously shown that Br treatment decreased activated CD4+ T cells and has a therapeutic role in an ovalbumin-induced murine model of allergic airway disease. The current study was designed to determine the effect of Br on CD4+ T cell activation, specifically the expression of CD25 in vitro. CD25 is up regulated upon T cell activation, found as a soluble fraction (sCD25) and is a therapeutic target in inflammation, autoimmunity and allergy. Br treatment of anti-CD3 stimulated CD4+ T cells reduced CD25 expression in a dose and time dependent manner. This reduction of CD25 was dependent on the proteolytic action of Br as the addition of E64 (a cysteine protease inhibitor) abrogated this response. The concentration of sCD25 was increased in supernatants of Br treated activated CD4+ T cells as compared to control cells, suggesting that Br proteolytically cleaved cell-surface CD25. This novel mechanism of action identifies how Br may exert its therapeutic benefits in inflammatory conditions.