The sulfiredoxin-peroxiredoxin redox system regulates the stemness and survival of colon cancer stem cells.

Cancer stem cells (CSCs) initiate tumor formation and are known to be resistant to chemotherapy. A metabolic alteration in CSCs plays a critical role in stemness and survival. However, the association between mitochondrial energy metabolism and the redox system remains undefined in colon CSCs. In this study, we assessed the role of the Sulfiredoxin-Peroxiredoxin (Srx-Prx) redox system and mitochondrial oxidative phosphorylation (OXPHOS) in maintaining the stemness and survival of colon CSCs. Notably, Srx contributed to the stability of PrxI, PrxII, and PrxIII proteins in colon CSCs. Increased Srx expression promoted the stemness and survival of CSCs and was important for the maintenance of the mitochondrial OXPHOS system. Furthermore, Nrf2 and FoxM1 led to OXPHOS activation and upregulated expression of Srx-Prx redox system-related genes. Therefore, the Nrf2/FoxM1-induced Srx-Prx redox system is a potential therapeutic target for eliminating CSCs in colon cancer.

BH4 activates CaMKK2 and rescues the cardiomyopathic phenotype in rodent models of diabetes.

Diabetic cardiomyopathy (DCM) is a major cause of mortality/morbidity in diabetes mellitus patients. Although tetrahydrobiopterin (BH4) shows therapeutic potential as an endogenous cardiovascular target, its effect on myocardial cells and mitochondria in DCM and the underlying mechanisms remain unknown. Here, we determined the involvement of BH4 deficiency in DCM and the therapeutic potential of BH4 supplementation in a rodent DCM model. We observed a decreased BH4:total biopterin ratio in heart and mitochondria accompanied by cardiac remodeling, lower cardiac contractility, and mitochondrial dysfunction. Prolonged BH4 supplementation improved cardiac function, corrected morphological abnormalities in cardiac muscle, and increased mitochondrial activity. Proteomics analysis revealed oxidative phosphorylation (OXPHOS) as the BH4-targeted biological pathway in diabetic hearts as well as BH4-mediated rescue of down-regulated peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) signaling as a key modulator of OXPHOS and mitochondrial biogenesis. Mechanistically, BH4 bound to calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) and activated downstream AMP-activated protein kinase/cAMP response element binding protein/PGC-1α signaling to rescue mitochondrial and cardiac dysfunction in DCM. These results suggest BH4 as a novel endogenous activator of CaMKK2.

Pharmacological inhibition of androgen receptor expression induces cell death in prostate cancer cells.

The androgen receptor (AR) plays an important role in the pathogenesis and development of prostate cancer (PCa). Mostly, PCa progresses to androgen-independent PCa, which has activated AR signaling from androgen-dependent PCa. Thus, inhibition of AR signaling may be an important therapeutic target in androgen-dependent and castration-resistant PCa. In this study, we determined the anticancer effect of a newly found natural compound, sakurasosaponin (S-saponin), using androgen-dependent and castration-resistant PCa cell lines. S-saponin induces mitochondrial-mediated cell death in both androgen-dependent (LNCaP) and castration-resistant (22Rv1 and C4-2) PCa cells, via AR expression. S-saponin treatment induces a decrease in AR expression in a time- and dose-dependent manner and a potent decrease in the expression of its target genes, including prostate-specific antigen (PSA), transmembrane protease, serin 2 (TMPRSS2), and NK3 homeobox 1 (NKX3.1). Furthermore, S-saponin treatment decreases B-cell lymphoma-extra large (Bcl-xL) and mitochondrial membrane potential, thereby increasing the release of cytochrome c into the cytosol. Moreover, Bcl-xL inhibition and subsequent mitochondria-mediated cell death caused by S-saponin were reversed by Bcl-xL or AR overexpression. Interestingly, S-saponin-mediated cell death was significantly reduced by a reactive oxygen species (ROS) scavenger, N-acetylcystein. Animal xenograft experiments showed that S-saponin treatment significantly reduced tumor growth of AR-positive 22Rv1 xenografts but not AR-negative PC-3 xenografts. Taken together, for the first time, our results revealed that S-saponin induces mitochondrial-mediated cell death in androgen-dependent and castration-resistant cells through regulation of AR mechanisms, including downregulation of Bcl-xL expression and induction of ROS stress by decreasing mitochondrial membrane potential.

Tetrahydrobiopterin enhances mitochondrial biogenesis and cardiac contractility via stimulation of PGC1α signaling.

Tetrahydrobiopterin (BH4) shows therapeutic potential as an endogenous target in cardiovascular diseases. Although it is involved in cardiovascular metabolism and mitochondrial biology, its mechanisms of action are unclear. We investigated how BH4 regulates cardiovascular metabolism using an unbiased multiple proteomics approach with a sepiapterin reductase knock-out (Spr-/-) mouse as a model of BH4 deficiency. Spr-/- mice exhibited a shortened life span, cardiac contractile dysfunction, and morphological changes. Multiple proteomics and systems-based data-integrative analyses showed that BH4 deficiency altered cardiac mitochondrial oxidative phosphorylation. Along with decreased transcription of major mitochondrial biogenesis regulatory genes, including Ppargc1a, Ppara, Esrra, and Tfam, Spr-/- mice exhibited lower mitochondrial mass and severe oxidative phosphorylation defects. Exogenous BH4 supplementation, but not nitric oxide supplementation or inhibition, rescued these cardiac and mitochondrial defects. BH4 supplementation also recovered mRNA and protein levels of PGC1α and its target proteins involved in mitochondrial biogenesis (mtTFA and ERRα), antioxidation (Prx3 and SOD2), and fatty acid utilization (CD36 and CPTI-M) in Spr-/- hearts. These results indicate that BH4-activated transcription of PGC1α regulates cardiac energy metabolism independently of nitric oxide and suggests that BH4 has therapeutic potential for cardiovascular diseases involving mitochondrial dysfunction.

Frugoside Induces Mitochondria-Mediated Apoptotic Cell Death through Inhibition of Sulfiredoxin Expression in Melanoma Cells.

Malignant melanoma is the most life-threatening neoplasm of the skin. Despite the increase in incidence, melanoma is becoming more resistant to current therapeutic agents. The bioactive compound frugoside has been recently reported to inhibit growth when used in various cancer cells. However, this effect has not been demonstrated in melanoma. Here, we found that frugoside inhibited the rate of reduction of hyperoxidized peroxiredoxins (Prxs) by downregulating sulfiredoxin (Srx) expression. Furthermore, frugoside increased the accumulation of sulfinic Prxs and reactive oxygen species (ROS) and stimulated p-p38 activation, resulting in the mitochondria-mediated death of M14 and A375 human melanoma cells. The mitochondria-mediated cell death induced by frugoside was inhibited by the overexpression of Srx and antioxidants, such as N-acetyl cysteine and diphenyleneiodonium. In addition, we observed that frugoside inhibited tumor growth without toxicity through a M14 xenograft animal model. Taken together, our findings reveal that frugoside exhibits a novel antitumor effect based on a ROS-mediated cell death in melanoma cells, which may have therapeutic implications.

Modulation of Mitochondrial ERß Expression Inhibits Triple-Negative Breast Cancer Tumor Progression by Activating Mitochondrial Function.

BACKGROUND/AIMS: Breast cancer is a clinically and molecularly heterogeneous disease. Patients with triple-negative breast cancer (TNBC) have poorer outcomes than those with other breast cancer subtypes due to lack of effective molecular targets for therapy. The present study aimed to the identification of estrogen receptor (ER)ß as a novel mitochondrial target in TNBC cells, together with underlying mechanisms. METHODS: Expression of ERß in clinical breast samples were examined by qRT-PCR, immunohistochemistry and immunoblotting. Subcellular distribution and binding of ERß-Grp75 was determined by confocal microscopic analysis, co-immunoprecipitation experiments, and limited-detergent extraction of subcellular organelles. The effect of mitocondrial ERß(mitoERß) overexpression on cell proliferation and cell cycle distribution were assessed CCK-8 assays and FACS. Mitochondrial ROS, membrane potential, and Ca²âº level were measured using the specific fluorescent probes Mito-Sox, TMRE, and Rhod-2AM. The tumorigenic effect of mitoERß overexpression was assessed using an anchorage-independent growth assay, sphere formation and a mouse orthotopic xenograft model. RESULTS: ERß expression was lower in tumor tissue than in adjacent normal tissue of patients with breast cancer, and low levels of mitochondrial ERß (mitoERß) also were associated with increased tumor recurrence after surgery. Overexpression of mitoERß inhibited the proliferation of TNBC cells and tumor masses in an animal model. Moreover, overexpression of mitoERß increased ATP production in TNBC cells and normal breast MCF10A cells, with the latter completely reversed by mitoERß knockdown in MCF10A cells. Grp75 was found to positively regulate ERß translocation into mitochondria via a direct interaction. Coimmunoprecipitation and subcellular fractionation experiments revealed that ERß-Grp75 complex is stable in mitochondria. CONCLUSION: These results suggest that the up-regulation of mitoERß in TNBC cells ensures proper mitochondrial transcription, activating the OXPHOS system to produce ATP. Studying the effects of mitoERß on mitochondrial activity and specific mitochondrial gene expression in breast cancer might help predict tumor recurrence, inform clinical decision-making, and identify novel drug targets in the treatment of TNBC.

Novel crosstalk between Vps26a and Nox4 signaling during neurogenesis.

Despite numerous studies on the molecular switches governing the conversion of stemness to differentiation in embryonic stem cells (ESCs), little is known about the involvement of the retromer complex. Under neural differentiation conditions, Vps26a deficiency (Vps26a-/-) or knockdown suppressed the loss of stemness and subsequent neurogenesis from ESCs or embryonic carcinoma cells, respectively, as evidenced by the long-lasting expression of stemness markers and the slow appearance of neuronal differentiation markers. Interestingly, relatively low reactive oxygen species (ROS) levels were generated during differentiation of Vps26a-/- ESCs, and treatment with an antioxidant or inhibitor of NADPH oxidase (Nox), a family of ROS-generating enzymes, led to restoration of stemness in wild-type cells to the level of Vps26a-/- cells during neurogenesis. Importantly, a novel interaction between Vps26a and Nox4 linked to the activation of ERK1/2 depended highly on ROS levels during neurogenesis, which were strongly suppressed in differentiating Vps26a-/- ESCs. Moreover, inhibition of phosphorylated ERK1/2 (pERK1/2) resulted in decreased ROS and Nox4 levels, indicating the mutual dependency between pERK1/2 and Nox4-derived ROS during neurogenesis. These results suggest that Vps26a regulates stemness by actively cooperating with the Nox4/ROS/ERK1/2 cascade during neurogenesis. Our findings have important implications for understanding the regulation of stemness via crosstalk between the retromer molecule and redox signaling, and may contribute to the development of ESC-based therapeutic strategies for the mass production of target cells.

Pharmacologic inhibition of AKT leads to cell death in relapsed multiple myeloma.

Multiple myeloma (MM) is a neoplastic plasma cell disorder with high disease recurrence rates. Novel therapeutic approaches capable of improving outcomes in patients with MM are urgently required. The AKT signalling plays a critical regulatory role in MM pathophysiology, including survival, proliferation, metabolism, and has emerged as a key therapeutic target. Here, we identified a novel AKT inhibitor, HS1793, and defined its mechanism of action and clinical significance in MM. HS1793 disrupted the interaction between AKT and heat shock protein 90, resulting in protein phosphatase 2A-modulated phosphorylated-AKT (p-AKT) reduction. Moreover, we observed reductions in the kinase activity of the AKT downstream target, IκB kinase alpha, and the transcriptional activity of nuclear factor kappa B, which induced mitochondria-mediated cell death in MM cells exclusively. We confirmed the cytotoxicity and specificity of HS1793 via PET-CT imaging of a metastatic mouse model generated using human MM cells. We also evaluated the cytotoxic effects of HS1793 in primary and relapsed MM cells isolated from patients. Thus, HS1793 offers great promise in eliminating MM cells and improving therapeutic responses in primary and relapsed/refractory MM patients.

Overexpression of peroxiredoxin-3 and -5 is a potential biomarker for prognosis in endometrial cancer.

Endometrial cancer is the sixth most common cancer in women worldwide. Peroxiredoxins (PRDXs) are antioxidant enzymes that serve important roles in cell differentiation, proliferation, and apoptosis. In the present study, the potential associations between PRDX expression and endometrial cancer were investigated. The expression levels of various PRDX mRNAs were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) in endometrial cancer tissues (n=26) and normal endometrial tissues (n=10). Additionally, the expression of PRDX isoforms was immunohistochemically examined in endometrial cancer tissues and adjacent normal endometrial tissues from 42 patients. Finally, the associations between high PRDX expression levels and clinicopathological features were examined in patients with endometrial cancer. Analysis of PRDX expression in endometrial cancer tissues and normal endometrial tissues by semi-quantitative RT-PCR showed that all PRDX isoforms had increased expression in the endometrial cancer tissues compared with that in the normal endometrium, and the differences in the expression levels of PRDX1 and PRDX3 between cancer and normal tissues were statistically significant (P=0.0015 and P=0.0134, respectively). Additionally, analysis of PRDX expression in endometrial cancer and paired normal endometrial tissues by immunohistochemistry showed strong cytoplasmic staining of PRDX3 and PRDX5 in cancer tissues, with high PRDX3 (25/42, 59.5%) and PRDX5 (32/42, 76.2%) appearing more frequently in endometrial cancer than in normal endometrial tissues (P=0.0001 and P=0.0023, respectively). Furthermore, high expression of PRDX5 was associated with advanced-stage endometrial cancer (P=0.0399). Although the 5-year survival rate was marginally higher in patients with low expression of PRDX3 and PRDX5, this result was not statistically significant. In summary, PRDX3 and PRDX5 are highly expressed in endometrial cancer and could be associated with advanced stage and poor prognosis. Therefore, these proteins may potentially be used as prognostic markers for endometrial cancer.

Resistance exercise improves cardiac function and mitochondrial efficiency in diabetic rat hearts.

Metabolic disturbance and mitochondrial dysfunction are a hallmark of diabetic cardiomyopathy (DC). Resistance exercise (RE) not only enhances the condition of healthy individuals but could also improve the status of those with disease. However, the beneficial effects of RE in the prevention of DC and mitochondrial dysfunction are uncertain. Therefore, this study investigated whether RE attenuates DC by improving mitochondrial function using an in vivo rat model of diabetes. Fourteen Otsuka Long-Evans Tokushima Fatty rats were assigned to sedentary control (SC, n = 7) and RE (n = 7) groups at 28 weeks of age. Long-Evans Tokushima Otsuka rats were used as the non-diabetic control. The RE rats were trained by 20 repetitions of climbing a ladder 5 days per week. RE rats exhibited higher glucose uptake and lower lipid profiles, indicating changes in energy metabolism. RE rats significantly increased the ejection fraction and fractional shortening compared with the SC rats. Isolated mitochondria in RE rats showed increase in mitochondrial numbers, which were accompanied by higher expression of mitochondrial biogenesis proteins such as proliferator-activated receptor-γ coactivator-1α and TFAM. Moreover, RE rats reduced proton leakage and reactive oxygen species production, with higher membrane potential. These results were accompanied by higher superoxide dismutase 2 and lower uncoupling protein 2 (UCP2) and UCP3 levels in RE rats. These data suggest that RE is effective at ameliorating DC by improving mitochondrial function, which may contribute to the maintenance of diabetic cardiac contractility.

Peroxiredoxin 3 maintains the survival of endometrial cancer stem cells by regulating oxidative stress.

Cancer stem cell (CSC)-targeted therapy could reduce tumor growth, recurrence, and metastasis in endometrial cancer (EC). The mitochondria of CSCs have been recently found to be an important target for cancer treatment, but the mitochondrial features of CSCs and their regulators, which maintain mitochondrial function, remain unclear. Here, we investigated the mitochondrial properties of CSCs, and identified specific targets for eliminating CSCs in EC. We found that endometrial CSCs displayed higher mitochondrial membrane potential, Ca2+, reactive oxygen species, ATP levels, and oxygen consumption rates than non-CSCs. Further, we also verified that mitochondrial peroxiredoxin 3 (Prx3) was upregulated, and that it contributed to the survival of CSCs in EC. The knockdown of the Prx3 gene resulted not only in decreased sphere formation, but also reduced the viability of endometrial CSCs, by causing mitochondrial dysfunction. Furthermore, we found that the forkhead box protein M1 (FoxM1), an important transcriptional factor, is overexpressed in patients with EC. FoxM1 expression correlates with elevated Prx3 expression levels, in agreement with the tumorigenic ability of Prx3 in endometrial CSCs. Taken together, our findings indicate that human endometrial CSCs have enhanced mitochondrial function compared to that of endometrial tumor cells. Endometrial CSCs show increased expression of the mitochondrial Prx3, which is required for the maintenance of mitochondrial function and survival, and is induced by FoxM1. Based on our findings, we believe that these proteins might represent valuable therapeutic targets and could provide new insights into the development of new therapeutic strategies for patients with endometrial cancer.

Chebulinic acid inhibits smooth muscle cell migration by suppressing PDGF-Rß phosphorylation and inhibiting matrix metalloproteinase-2 expression.

Excessive migration of vascular smooth muscle cells (VSMCs) after vascular injury contributes to the development of occlusive vascular disease. Inhibition of VSMC migration is a validated therapeutic modality for occlusive vascular diseases, such as atherosclerosis and restenosis. We investigated the inhibitory effect of chebulinic acid (CBA) on cell migration and matrix metalloproteinase (MMP)-2 activation in platelet-derived growth factor (PDGF)-BB-induced mouse and human VSMCs. CBA significantly inhibited PDGF-BB-induced migration in mouse and human VSMCs, without inducing cell death. Additionally, CBA significantly blocked PDGF-BB-induced phosphorylation of the PDGF receptor (PDGF-R), Akt, and extracellular signal-regulated kinase (ERK)1/2 by inhibiting the activation of the PDGF-BB signalling pathway. In both mouse and human VSMCs, CBA inhibited PDGF-induced MMP-2 mRNA and protein expression as well as the proteolytic activity of MMP-2. Moreover, CBA suppressed sprout outgrowth formation of VSMCs from endothelium-removed aortic rings as well as neointima formation following rat carotid balloon injury. Taken together, our findings indicated that CBA inhibits VSMC migration by decreasing MMP-2 expression through PDGF-R and the ERK1/2 and Akt pathways. Our data may improve the understanding of the antiatherogenic effects of CBA in VSMCs.

Glucocorticoid receptor positively regulates transcription of FNDC5 in the liver.

Irisin is secreted by skeletal muscle during exercise and influences energy and metabolic homeostasis. This hormone is a cleaved and secreted fragment of fibronectin type III domain-containing 5 (FNDC5). Elucidation of the FNDC5 gene regulation mechanism is necessary to clarify the function of irisin as a potential therapeutic target in human metabolic diseases. Thus, we investigated the genetic and epigenetic mechanisms that regulate expression of the FNDC5 gene. FNDC5 mRNA was strong expressed in major energy-dependent human tissues, including heart, brain, liver, and skeletal muscle. Promoter analysis of the FNDC5 gene revealed that the core promoter region of the FNDC5 gene contained one CpG island that was located just upstream of the transcriptional start site for variants 2 and 3. Treatment with the histone deacetylase inhibitor sodium butyrate and the demethylating agent 5-azacytidine increased mRNA expression of FNDC5 in Huh7 cells. Prediction of transcription factor binding sites suggested that the glucocorticoid receptor was involved in the regulation of FNDC5 expression, and indeed, cortisol treatment increased mRNA expression of FNDC5 in Huh7 cells. Collectively, these findings offer insight into the genetic and epigenetic regulation of FNDC5, providing the initial steps required for understanding the role of irisin in the metabolic homeostasis.

Clonorchis sinensis excretory-secretory products regulate migration and invasion in cholangiocarcinoma cells via extracellular signal-regulated kinase 1/2/nuclear factor-κB-dependent matrix metalloproteinase-9 expression.

Matrix metalloproteinase-9 plays an important role in the invasion and metastasis of various types of cancer cells. We have previously reported that excretory-secretory products from Clonorchis sinensis increases matrix metalloproteinase-9 expression. However, the regulatory mechanisms through which matrix metalloproteinase-9 expression affects cholangiocarcinoma development remain unclear. In the current study, we examined the potential role of excretory-secretory products in regulating the migration and invasion of various cholangiocarcinoma cell lines. We demonstrated that excretory-secretory products significantly induced matrix metalloproteinase-9 expression and activity in a concentration-dependent manner. Reporter gene and chromatin immunoprecipitation assays showed that excretory-secretory products induced matrix metalloproteinase-9 expression by enhancing the activity of nuclear factor-kappa B. Moreover, excretory-secretory products induced the degradation and phosphorylation of IκBα and stimulated nuclear factor-kappa B p65 nuclear translocation, which was regulated by extracellular signal-regulated kinase 1/2. Taken together, our findings indicated that the excretory-secretory product-dependent enhancement of matrix metalloproteinase-9 activity and subsequent induction of IκBα and nuclear factor-kappa B activities may contribute to the progression of cholangiocarcinoma.

Upregulation of annexin A1 expression by butyrate in human melanoma cells induces invasion by inhibiting E-cadherin expression.

Epithelial to mesenchymal transition (EMT) is a critical step in the metastasis of epithelial cancer cells. Butyrate, which is produced from dietary fiber by colonic bacterial fermentation, has been reported to influence EMT. However, some studies have reported that butyrate promotes EMT, while others have reported an inhibitory effect. To clarify these controversial results, it is necessary to elucidate the mechanism by which butyrate can influence EMT. In this study, we examined the potential role of annexin A1 (ANXA1), which was previously reported to promote EMT in breast cancer cells, as a mediator of EMT regulation by butyrate. We found that ANXA1 mRNA and protein were expressed in highly invasive melanoma cell lines (A2058 and A375), but not in SK-MEL-5 cells, which are less invasive. We also showed that butyrate induced ANXA1 mRNA and protein expression and promoted EMT-related cell invasion in SK-MEL-5 cells. Downregulation of ANXA1 expression using specific small interfering RNAs in butyrate-treated SK-MEL-5 cells resulted in increased expression of the epithelial marker E-cadherin and decreased cell invasion. Moreover, overexpressing ANXA1 decreased the expression of the E-cadherin. Collectively, these results indicate that butyrate induces the expression of ANXA1 in human melanoma cells, which then promotes invasion through activating the EMT signaling pathway.

Mitochondrial pyruvate dehydrogenase phosphatase 1 regulates the early differentiation of cardiomyocytes from mouse embryonic stem cells.

Mitochondria are crucial for maintaining the properties of embryonic stem cells (ESCs) and for regulating their subsequent differentiation into diverse cell lineages, including cardiomyocytes. However, mitochondrial regulators that manage the rate of differentiation or cell fate have been rarely identified. This study aimed to determine the potential mitochondrial factor that controls the differentiation of ESCs into cardiac myocytes. We induced cardiomyocyte differentiation from mouse ESCs (mESCs) and performed microarray assays to assess messenger RNA (mRNA) expression changes at differentiation day 8 (D8) compared with undifferentiated mESCs (D0). Among the differentially expressed genes, Pdp1 expression was significantly decreased (27-fold) on D8 compared to D0, which was accompanied by suppressed mitochondrial indices, including ATP levels, membrane potential, ROS and mitochondrial Ca(2+). Notably, Pdp1 overexpression significantly enhanced the mitochondrial indices and pyruvate dehydrogenase activity and reduced the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate compared to a mock control. In confirmation of this, a knockdown of the Pdp1 gene promoted the expression of cardiac differentiation marker mRNA and the cardiac differentiation rate. In conclusion, our results suggest that mitochondrial PDP1 is a potential regulator that controls cardiac differentiation at an early differentiation stage in ESCs.

NecroX-5 protects mitochondrial oxidative phosphorylation capacity and preserves PGC1α expression levels during hypoxia/reoxygenation injury.

Although the antioxidant and cardioprotective effects of NecroX-5 on various in vitro and in vivo models have been demonstrated, the action of this compound on the mitochondrial oxidative phosphorylation system remains unclear. Here we verify the role of NecroX-5 in protecting mitochondrial oxidative phosphorylation capacity during hypoxia-reoxygenation (HR). Necrox-5 treatment (10 µM) and non-treatment were employed on isolated rat hearts during hypoxia/reoxygenation treatment using an ex vivo Langendorff system. Proteomic analysis was performed using liquid chromatography-mass spectrometry (LC-MS) and non-labeling peptide count protein quantification. Real-time PCR, western blot, citrate synthases and mitochondrial complex activity assays were then performed to assess heart function. Treatment with NecroX-5 during hypoxia significantly preserved electron transport chain proteins involved in oxidative phosphorylation and metabolic functions. NecroX-5 also improved mitochondrial complex I, II, and V function. Additionally, markedly higher peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC1α) expression levels were observed in NecroX-5-treated rat hearts. These novel results provide convincing evidence for the role of NecroX-5 in protecting mitochondrial oxidative phosphorylation capacity and in preserving PGC1α during cardiac HR injuries.

Moxifloxacin-containing triple therapy after non-bismuth quadruple therapy failure for Helicobacter pylori infection.

AIM: To assess the efficacy of moxifloxacin-containing triple therapy after non-bismuth quadruple therapy failure for Helicobacter pylori (H. pylori) eradication. METHODS: Between January 2010 and December 2012, we screened individuals who were prescribed non-bismuth quadruple therapy for H. pylori eradication. Among them, a total of 98 patients who failed non-bismuth quadruple therapy received 1-wk or 2-wk moxifloxacin-containing triple therapy (400 mg moxifloxacin once daily, and 20 mg of rabeprazole and 1 g of amoxicillin twice daily). H. pylori status was evaluated using the (13)C-urea breath test 4 wk later, after treatment completion. The eradication rates were determined by intention-to-treat and per-protocol analyses. RESULTS: In total, 60 and 38 patients received 1-wk and 2-wk moxifloxacin-containing triple therapy, respectively. The intention-to-treat and per-protocol eradication rates were 56.7% (95%CI: 45.0-70.0) and 59.6% (95%CI: 46.6-71.7) in the 1-wk group and 76.3% (95%CI: 63.2-89.5) and 80.6% (95%CI: 66.7-91.9) in the 2-wk group (P = 0.048 and 0.036, respectively). All groups had good compliance (95% vs 94.9%). Neither group showed serious adverse events, and the proportions of patients experiencing mild side effects were not significantly different (21.1% vs 13.9%). Clinical factors such as age, sex, alcohol and smoking habits, comorbidities, and presence of gastric or duodenal ulcer did not influence the eradication therapy efficacy. The efficacy of second-line eradication therapy did not differ significantly according to the first-line regimen. CONCLUSION: Two-week moxifloxacin-containing triple therapy showed better efficacy than a 1-wk regimen after non-bismuth quadruple therapy failure.