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 (Trx1 Tg/+ ) mice were randomized into W Sham (WS), Trx1 Tg/+ 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 and p-GSK-3β, HIF-1α, β-catenin, VEGF, Bcl-2 and survivin expression in TMI compared to WMI. Echocardiography performed 30 days 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.

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-1α-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 2 h of reperfusion. TMC hearts were perfused for 2 h 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-1α was significantly increased in PHD1IR compared to WTIR. mRNA expression of β-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 with WTIR, which was studied by real-time quantitative polymerase chain reaction. Further, gel-shift analysis showed increased DNA binding activity of HIF-1α and nuclear factor-kappaB in PHD1IR compared to WTIR. In addition, nuclear translocation of β-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-1α/β-catenin/endothelial nitric oxide synthase/nuclear factor-kappaB and Bcl-2 signaling pathway.

This review presents a comprehensive and current account of the existing small-molecule PHDIs and their use in the treatment of ischemic diseases with a focus on the molecular mechanisms of therapeutic action in animal models.

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.

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.