Coenzyme Q0 inhibited the NLRP3 inflammasome, metastasis/EMT, and Warburg effect by suppressing hypoxia-induced HIF-1α expression in HNSCC cells.

Coenzyme Q0 (CoQ0), a quinone derivative from Antrodia camphorata, has antitumor capabilities. This study investigated the antitumor effect of noncytotoxic CoQ0, which included NLRP3 inflammasome inhibition, anti-EMT/metastasis, and metabolic reprogramming via HIF-1α inhibition, in HNSCC cells under normoxia and hypoxia. CoQ0 suppressed hypoxia-induced ROS-mediated HIF-1α expression in OECM-1 and SAS cells. Under normoxia and hypoxia, the inflammatory NLRP3, ASC/caspase-1, NFκB, and IL-1ß expression was reduced by CoQ0. CoQ0 reduced migration/invasion by enhancing epithelial marker E-cadherin and suppressing mesenchymal markers Twist, N-cadherin, Snail, and MMP-9, and MMP-2 expression. CoQ0 inhibited glucose uptake, lactate accumulation, GLUT1 levels, and HIF-1α-target gene (HK-2, PFK-1, and LDH-A) expressions that are involved in aerobic glycolysis. Notably, CoQ0 reduced ECAR as well as glycolysis, glycolytic capability, and glycolytic reserve and enhanced OCR, basal respiration, ATP generation, maximal respiration, and spare capacity in OECM-1 cells. Metabolomic analysis using LC-ESI-MS showed that CoQ0 treatment decreased the levels of glycolytic intermediates, including lactate, 2/3-phosphoglycerate, fructose 1,6-bisphosphate, and phosphoenolpyruvate, and increased the levels of TCA cycle metabolites, including citrate, isocitrate, and succinate. HIF-1α silencing reversed CoQ0-mediated anti-metastasis (N-Cadherin, Snail, and MMP-9) and metabolic reprogramming (GLUT1, HK-2, and PKM-2) under hypoxia. CoQ0 prevents cancer stem-like characteristics (upregulated CD24 expression and downregulated CD44, ALDH1, and OCT4) under normoxia and/or hypoxia. Further, in IL-6-treated SG cells, CoQ0 attenuated fibrosis by inhibiting TGF-ß and Collagen I expression and suppressed EMT by downregulating Slug and upregulating E-cadherin expression. Interesting, CoQ0 inhibited the growth of OECM-1 tumors in xenografted mice. Our results advocate CoQ0 for the therapeutic application against HNSCC.

The in vitro and in vivo depigmentation activity of coenzyme Q0, a major quinone derivative from Antrodia camphorata, through autophagy induction in human melanocytes and keratinocytes.

BACKGROUND: Coenzyme Q0 (CoQ0), a novel quinone derivative of Antrodia camphorata, has been utilized as a therapeutic agent (including antioxidant, anti-inflammatory, antiangiogenic, antiatherosclerotic, and anticancer agents); however, its depigmenting efficiency has yet to be studied. METHODS: We resolved the depigmenting efficiency of CoQ0 through autophagy induction in melanoma (B16F10) and melanin-feeding keratinocyte (HaCaT) cells and in vivo Zebrafish model. Then, MPLC/HPLC analysis, MTT assay, Western blotting, immunofluorescence staining, LC3 transfection, melanin formation, GFP-LC3 puncta, AVO formation, tyrosinase activity, and TEM were used. RESULTS: CoQ0-induced autophagy in B16F10 cells was shown by enhanced LC3-II accumulation, ATG7 expression, autophagosome GFP-LC3 puncta, and AVOs formation, and ATG4B downregulation, and Beclin-1/Bcl-2 dysregulation. In α-MSH-stimulated B16F10 cells, CoQ0 induced antimelanogenesis by suppressing CREB-MITF pathway, tyrosinase expression/activity, and melanin formation via autophagy. TEM data disclosed that CoQ0 increased melanosome-engulfing autophagosomes and autolysosomes in α-MSH-stimulated B16F10 cells. CoQ0-inhibited melanogenesis in α-MSH-stimulated B16F10 cells was reversed by pretreatment with the autophagy inhibitor 3-MA or silencing of LC3. Additionally, CoQ0-induced autophagy in HaCaT cells was revealed by enhanced LC3-II accumulation, autophagosome GFP-LC3 puncta and AVO formation, ATG4B downregulation, ATG5/ATG7 expression, and Beclin-1/Bcl-2 dysregulation. In melanin-feeding HaCaT cells, CoQ0 induced melanin degradation by suppressing melanosome gp100 and melanin formation via autophagy. TEM confirmed that CoQ0 increased melanosome-engulfing autophagosomes and autolysosomes in melanin-feeding HaCaT cells. Treatment with 3-MA reversed CoQ0-mediated melanin degradation in melanin-feeding HaCaT cells. In vivo study showed that CoQ0 suppressed endogenous body pigmentation by antimelanogenesis and melanin degradation through autophagy induction in a zebrafish model. CONCLUSIONS: Our results showed that CoQ0 exerted antimelanogenesis and melanin degradation by inducing autophagy. CoQ0 could be used in skin-whitening formulations as a topical cosmetic application.

Exendin-4 protects against high glucose-induced mitochondrial dysfunction and oxidative stress in SH-SY5Y neuroblastoma cells through GLP-1 receptor/Epac/Akt signaling.

Mitochondrial dysfunction under diabetic condition leads to the development and progression of neurodegenerative complications. Recently, the beneficial effects of glucagon-like peptide-1 (GLP-1) receptor agonists on diabetic neuropathies have been widely recognized. However, molecular mechanisms underlying the neuroprotective effects of GLP-1 receptor agonists against high glucose (HG)-induced neuronal damages is not completely elucidated. Here, we investigated the underlying mechanisms of GLP-1 receptor agonist treatment against oxidative stress, mitochondrial dysfunction, and neuronal damages under HG conditions mimicking a diabetic hyperglycemic state in SH-SY5Y neuroblastoma cells. We revealed that treatment with exendin-4, a GLP-1 receptor agonist, not only increased the expression of survival markers, phospho-Akt/Akt and Bcl-2, but also decreased the expression of pro-apoptotic marker, Bax, and reduced the levels of reactive oxygen species (ROS) defense markers (catalase, SOD-2, and HO-1) under HG conditions. The expressions of mitochondrial function associated genes, MCU and UCP3, and mitochondrial fission genes, DRP1 and FIS1, were decreased by exendin-4 compared to non-treated levels, while the protein expression levels of mitochondrial homeostasis regulators, Parkin and PINK1, were enhanced. In addition, blockade of Epac and Akt activities was able to antagonize these neuroprotective effects of exendin-4. Collectively, we demonstrated that stimulation of GLP-1 receptor propagates a neuroprotective cascade against the oxidative stress and mitochondrial dysfunction as well as augments survival through the Epac/Akt-dependent pathway. Therefore, the revealed mechanisms underlying GLP-1 receptor pathway by preserving mitochondrial homeostasis would be a therapeutic candidate to alleviate neuronal dysfunctions and delay the progression of diabetic neuropathies.

Antrodia camphorata and coenzyme Q0 , a novel quinone derivative of Antrodia camphorata, impede HIF-1α and epithelial-mesenchymal transition/metastasis in human glioblastoma cells.

Antrodia camphorata (AC) and Coenzyme Q0 (CoQ0 ), a novel quinone derivative of AC, exhibits antitumor activities. The present study evaluated EMT/metastasis inhibition and autophagy induction aspects of AC and CoQ0 in human glioblastoma (GBM8401) cells. Our findings revealed that AC treatment (0-150 µg/mL) hindered tumor cell proliferation and migration/invasion in GBM8401 cells. Notably, AC treatment inhibited HIF-1α and EMT by upregulating epithelial marker protein E-cadherin while downregulating mesenchymal proteins Twist, Slug, Snail, and ß-catenin. There was an appearance of the autophagy markers LC3-II and p62/SQSTM1, while ATG4B was downregulated by AC treatment. We also found that CoQ0 (0-10 µM) could inhibit migration and invasion in GBM8401 cells. In particular, E-cadherin was elevated and N-cadherin, Vimentin, Twist, Slug, and Snail, were reduced upon CoQ0 treatment. In addition, MMP-2/-9 expression and Wnt/ß-catenin pathways were downregulated. Furthermore, autophagy inhibitors 3-MA or CQ reversed the CoQ0 -elicited suppression of migration/invasion and metastasis-related proteins (Vimentin, Snail, and ß-catenin). Results suggested autophagy-mediated antiEMT and antimetastasis upon CoQ0 treatment. CoQ0 inhibited HIF-1α and metastasis in GBM8401 cells under normoxia and hypoxia. HIF-1α knockdown using siRNA accelerated CoQ0 -inhibited migration. Finally, CoQ0 exhibited a prolonged survival rate in GBM8401-xenografted mice. Treatment with Antrodia camphorata/CoQ0 inhibited HIF-1α and EMT/metastasis in glioblastoma.

The in vitro and in vivo anticancer activities of Antrodia salmonea through inhibition of metastasis and induction of ROS-mediated apoptotic and autophagic cell death in human glioblastoma cells.

BACKGROUND: Antrodia salmonea (AS) exhibits anticancer activities against various cancers. OBJECTIVE: This study investigated the anticancer activities of AS on human glioblastoma (GBM8401 and U87MG) cells both in vitro and in vivo and explained the underlying molecular mechanism. METHODS: MTT, colony formation, migration/invasion assay, immunoblotting, immunofluorescence, TUNEL, Annexin V/PI staining, AO staining, GFP-LC3 transfection, TEM, qPCR, siLC3, DCFH2-DA assay, and xenografted-nude mice were used to assess the potential of AS therapy. RESULTS: AS treatment retarded growth and suppressed colony formation in glioblastoma cells. AS attenuates EMT by suppressing invasion and migration, increasing E-cadherin expression, decreasing Twist, Snail, and N-cadherin expression, and inhibiting Wnt/ß-catenin pathways in GBM8401 and U87MG cells. Furthermore, AS induced apoptosis by activating caspase-3, cleaving PARP, and dysregulating Bax and Bcl-2 in both cell lines. TUNEL assay and Annexin V/PI staining indicated AS-mediated late apoptosis. Interestingly, AS induced autophagic cell death by LC3-II accumulation, AVO formation, autophagosome GFP-LC3 puncta, p62/SQSTM1 expression, and ATG4B inhibition in GBM8401 and U87MG cells. TEM data revealed that AS favored autophagosome and autolysosome formation. The autophagy inhibitors 3-MA/CQ and LC3 knockdown suppressed AS-induced apoptosis in glioblastoma cells, indicating that the inhibition of autophagy decreased AS-induced apoptosis. Notably, the antioxidant N-acetylcysteine (NAC) inhibited AS-mediated ROS production and AS-induced apoptotic and autophagic cell death. Furthermore, AS induced ROS-mediated inhibition of the PI3K/AKT/mTOR signaling pathway. AS reduced the tumor burden in GBM8401-xenografted nude mice and significantly modulated tumor xenografts by inducing anti-EMT, apoptosis, and autophagy. AS could be a potential antitumor agent in human glioblastoma treatment.

In vitro and in vivo anti-tumor activity of Coenzyme Q0 against TWIST1-overexpressing HNSCC cells: ROS-mediated inhibition of EMT/metastasis and autophagy/apoptosis induction.

HNSCC (Head and Heck Squamous Cell Carcinoma) is a reasonably prevalent cancer with a high mortality rate. In this study, we tried to examine the anti-metastasis and apoptosis/autophagy actions of Coenzyme Q0 (CoQ0, 2,3-dimethoxy-5-methyl-1,4-benzoquinone), a derivative of Antrodia camphorata in HNCC TWIST1 overexpressing (FaDu-TWIST1) cells as well as in vivo tumor xenograft mice model. Using fluorescence based cellular assays, western blot and nude mice tumor xenografts, we determined that CoQ0 effectively reduced cell viability and displayed rapid morphological changes in FaDu-TWIST1 cells compared to FaDu cells. Non/sub-cytotoxic concentrations of CoQ0 treatment reduces the cell migration by downregulating TWIST1 and upregulating E-cadherin. Apoptosis produced by CoQ0 was mostly related with caspase-3 activation, PARP cleavage, and VDAC-1 expression. The FaDu-TWIST1 cells treated with CoQ0 exhibits autophagy-mediated LC3-II accumulation and acidic vesicular organelles (AVOs) formation. Pre-treatment with 3-MA and CoQ effectively prevented CoQ0-induced cell death and CoQ0-triggered autophagy in FaDu-TWIST cells as a death mechanism. CoQ0 induces ROS production in FaDu-TWIST1 cells and NAC pre-treatment significantly reduces anti-metastasis, apoptosis, and autophagy. Likewise, ROS-mediated AKT inhibition regulates CoQ0-induced apoptosis/autophagy in FaDu-TWIST1 cells. In vivo studies exhibit, CoQ0 effectively delays and reduces the tumor incidence and burden in FaDu-TWIST1-xenografted nude mice. Current findings display, CoQ0 exhibits a novel anti-cancer mechanism hence, it might be appropriate for anticancer therapy, and a new potent drug for HNSCC.

In vitro and in vivo anti-tumor activity of Antrodia salmonea against twist-overexpressing HNSCC cells: Induction of ROS-mediated autophagic and apoptotic cell death.

Head and neck squamous cell carcinoma (HNSCC) is a relatively common malignancy, characterized by lethal morbidity. Herein, we attempted to investigate the autophagy/apoptosis activities of the submerged fermented broths of Antrodia salmonea (AS) in HNSCC Twist-overexpressing (OECM-1 and FaDu-Twist) cells. AS (0-150 µg/mL) effectively reduced cell viability, colony formation, and downregulated Twist expression in OECM-1 and FaDu-Twist cells compared to FaDu cells. AS- induced apoptosis was mainly associated with activation of caspase-3, PARP cleavage, increased expression of VDAC-1 and disproportionation of Bax/Bcl-2. Annexin V/PI staining suggested late apoptosis induction by AS treatment. AS exhibits enhanced autophagy process mediated via LC3-I/II accumulation, increased acidic vesicular organelles (AVOs) formation and p62/SQSTM1 expression feeding into the apoptotic program. However, pre-treatment with autophagy blockers 3-MA and CQ significantly diminished AS-induced cell death. Additionally, suppression of AS-induced ROS release by treatment with antioxidant N-acetylcysteine (NAC) resulted in reduction of apoptotic and autophagic cell death. In vivo studies strengthened the above observations and showed that AS effectively reduced the tumor volume and tumor weight in OECM-1-xenografted nude mice. This study discovered that Antrodia salmonea exhibits a novel anti-cancer mechanism which could be harnessed as a new potent drug for HNSCC treatment.

Stimulation of adenosine A1 receptor prevents oxidative injury in H9c2 cardiomyoblasts: Role of Gßγ-mediated Akt and ERK1/2 signaling.

Oxidative stress causes cellular injury and damage in the heart primarily through apoptosis resulting in cardiac abnormalities such as heart failure and cardiomyopathy. During oxidative stress, stimulation of adenosine receptor (AR) has been shown to protect against oxidative damage due to their cytoprotective properties. However, the subtype specificity and signal transductions of adenosine A1 receptor (A1R) on cardiac protection during oxidative stress have remained elusive. In this study, we found that stimulation of A1Rs with N6-cyclopentyladenosine (CPA), a specific A1R agonist, attenuated the H2O2-induced intracellular and mitochondrial reactive oxygen species (ROS) production and apoptosis. In addition, A1R stimulation upregulated the synthesis of antioxidant enzymes (catalase and GPx-1), antiapoptotic proteins (Bcl-2 and Bcl-xL), and mitochondria-related markers (UCP2 and UCP3). Blockades of Gßγ subunit of heterotrimeric Gαi protein antagonized A1R-mediated antioxidant and antiapoptotic effects, confirming the potential role of Gßγ subunit-mediated A1R signaling. Additionally, cardioprotective effects of CPA mediated through PI3K/Akt- and ERK1/2-dependent signaling pathways. Thus, we propose that A1R represents a promising therapeutic target for prevention of oxidative injury in the heart.

Coenzyme Q0 Inhibits NLRP3 Inflammasome Activation through Mitophagy Induction in LPS/ATP-Stimulated Macrophages.

Coenzyme Q (CoQ) analogs with a variable number of isoprenoid units have exhibited as anti-inflammatory as well as antioxidant molecules. Using novel quinone derivative CoQ0 (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero side chain isoprenoid), we studied its molecular activities against LPS/ATP-induced inflammation and redox imbalance in murine RAW264.7 macrophages. CoQ0's non- or subcytotoxic concentration suppressed the NLRP3 inflammasome and procaspase-1 activation, followed by downregulation of IL1ß expression in LPS/ATP-stimulated RAW264.7 macrophages. Similarly, treatment of CoQ0 led to LC3-I/II accumulation and p62/SQSTM1 activation. An increase in the Beclin-1/Bcl-2 ratio and a decrease in the expression of phosphorylated PI3K/AKT, p70 S6 kinase, and mTOR showed that autophagy was activated. Besides, CoQ0 increased Parkin protein to recruit damaged mitochondria and induced mitophagy in LPS/ATP-stimulated RAW264.7 macrophages. CoQ0 inhibited LPS/ATP-stimulated ROS generation in RAW264.7 macrophages. Notably, when LPS/ATP-stimulated RAW264.7 macrophages were treated with CoQ0, Mito-TEMPO (a mitochondrial ROS inhibitor), or N-acetylcysteine (NAC, a ROS inhibitor), there was a significant reduction of LPS/ATP-stimulated NLRP3 inflammasome activation and IL1ß expression. Interestingly, treatment with CoQ0 or Mito-TEMPO, but not NAC, significantly increased LPS/ATP-induced LC3-II accumulation indicating that mitophagy plays a key role in the regulation of CoQ0-inhibited NLRP3 inflammasome activation. Nrf2 knockdown significantly decreased IL1ß expression in LPS/ATP-stimulated RAW264.7 macrophages suggesting that CoQ0 inhibited ROS-mediated NLRP3 inflammasome activation and IL1ß expression was suppressed due to the Nrf2 activation. Hence, this study showed that CoQ0 might be a promising candidate for the therapeutics of inflammatory disorders due to its effective anti-inflammatory as well as antioxidant properties.

Metronomic Celecoxib Therapy in Clinically Available Dosage Ablates Hepatocellular Carcinoma via Suppressing Cell Invasion, Growth, and Stemness in Pre-Clinical Models.

OBJECTIVE: To investigate the anti-carcinogenic effect of metronomic Celecoxib (i.e., frequent administration in clinically available doses) against hepatocellular carcinoma (HCC) in the perspective of metastasis, spontaneous hepatocarcinogenesis, cancer invasion, proliferation, and stemness in vivo and in vitro. BACKGROUND: Celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is known to cause anti-carcinogenic effects for HCC in suprapharmacological doses. However, the effects of metronomic Celecoxib treatment on HCC cells remain unclear. METHODS: The in vivo chemopreventive effect of metronomic Celecoxib (10mg/kg/d) was investigated by the syngeneic HCC implantation model and spontaneous hepatocarcinogenesis in HBV-transgenic(HBVtg) mice individually. HCC cell lines were treated by either suprapharmacological (100 µM) or metronomic (4 µM) Celecoxib therapy. Anti-carcinogenic effects were evaluated using cell invasion, cancer proliferation, angiogenesis, and phenotype of cancer stem/progenitor cells (CSPC). The molecular mechanism of metronomic Celecoxib on HCC was dissected using Luciferase assay. RESULTS: In vivo metronomic Celecoxib exerted its chemopreventive effect by significantly reducing tumor growth of implanted syngeneic HCC and spontaneous hepatocarcinogenesis in HBVtg mice. Unlike suprapharmacological dose, metronomic Celecoxib can only inhibit HCC cell invasion after a 7-day course of treatment via NF-κB/MMP9 dependent, COX2/PGE2 independent pathway. Metronomic Celecoxib also significantly suppressed HCC cell proliferation after a 7-day or 30-day culture. Besides, metronomic Celecoxib reduced CSPC phenotype by diminishing sphere formation, percentage of CD90+ population in sphere cells, and expression of CSPC markers. CONCLUSIONS: Metronomic Celecoxib should be investigated clinically as a chemopreventive agent for selected high-risk HCC patients (e.g., HCC patients after curative treatments).

Insulin-like growth factor II receptor-α is a novel stress-inducible contributor to cardiac damage underpinning doxorubicin-induced oxidative stress and perturbed mitochondrial autophagy.

Doxorubicin (DOX) is an anthracycline antibiotic commonly employed for the treatment of various cancers. However, its therapeutic uses are hampered by side effects associated with cumulative doses during the course of treatment. Whereas deregulation of autophagy in the myocardium has been involved in a variety of cardiovascular diseases, the role of autophagy in DOX-induced cardiomyopathy remains debated. Our earlier studies have shown that DOX treatment in a rat animal model leads to increased expression of the novel stress-inducible protein insulin-like growth factor II receptor-α (IGF-IIRα) in cardiac tissues, which exacerbated the cardiac injury by enhancing oxidative stress and p53-mediated mitochondria-dependent cardiac apoptosis. Through this study, we investigated the contribution of IGF-IIRα to dysregulation of autophagy in heart using both in vitro H9c2 cells (DOX treated, 1 µM) and in vivo transgenic rat models (DOX treated, 5 mg/kg ip for 6 wk) overexpressing IGF-IIRα specifically in the heart. We found that IGF-IIRα primarily localized to mitochondria, causing increased mitochondrial oxidative stress that was severely aggravated by DOX treatment. This was accompanied by a significant perturbation in mitochondrial membrane potential and increased leakage of cytochrome c, causing increased cleaved caspase-3 activity. There were significant alterations in phosphorylated AMP-activated protein kinase (p-AMPK), phosphorylated Unc-51 like kinase-1 (p-ULK1), PARKIN, PTEN-induced kinase 1 (PINK1), microtubule-associated protein 1 light chain 3 (LC3), and p62 proteins, which were more severely disrupted under the combined effect of IGF-IIRα overexpression plus DOX. Finally, LysoTracker Red staining showed that IGF-IIRα overexpression causes lysosomal impairment, which was rescued by rapamycin treatment. Taken together, we found that IGF-IIRα leads to mitochondrial oxidative stress, decreased antioxidant levels, disrupted mitochondrial membrane potential, and perturbed mitochondrial autophagy contributing to DOX-induced cardiomyopathy.

Upregulation of IGF-IIRα intensifies doxorubicin-induced cardiac damage.

Cardiotoxicity by doxorubicin hampers its therapeutic potential as an anticancer drug, but mechanisms leading to cardiotoxicity remain contentious. Through this study, the functional contribution of insulin-like growth factor receptor type II α (IGF-IIRα) which is a novel stress-inducible protein was explored in doxorubicin-induced cardiac stress. Employing both in vitro H9c2 cells and in vivo transgenic rat models (SD-TG [IGF-IIRα]) overexpressing IGF-IIRα specifically in heart, we found that IGF-IIRα leads to cardiac structural abnormalities and functional perturbations that were severely aggravated by doxorubicin-induced cardiac stress. Overexpression of IGF-IIRα leads to cumulative elevation of stress associated cardiac hypertrophy and apoptosis factors. There was a significant reduction of survival associated proteins p-Akt and estrogen receptor ß/α, and abnormal elevation of cardiac hypertrophy markers such as atrial natriuretic peptide, cardiac troponin-I, and apoptosis-inducing agents such as p53, Bax, and cytochrome C, respectively. IGF-IIRα also altered the expressions of AT1R, ERK1/2, and p38 proteins. Besides, IGF-IIRα also increased the reactive oxygen species production in H9c2 cells which were markedly aggravated by doxorubicin treatment. Together, we showed that IGF-IIRα is a novel stress-induced protein that perturbed cardiac homeostasis and cumulatively exacerbated the doxorubicin-induced cardiac injury that perturbed heart functions and ensuing cardiomyopathy.

Luteolin: A Natural Flavonoid Enhances the Survival of HUVECs against Oxidative Stress by Modulating AMPK/PKC Pathway.

Oxidative stress has been implicated in the pathogenesis of atherosclerotic cardiovascular diseases. Dietary supplementation of anti-oxidants has been reported to have beneficial effects on the prevention of atherogenic diseases. Luteolin (a natural flavonoid) has been shown to possess antimutagenic, antitumorigenic, anti-oxidant and anti-inflammatory properties. However, the effects and underlying molecular mechanisms of luteolin on cardiovascular systems are poorly explored. Therefore, the aim of the present study was to test whether luteolin could protect against oxidative stress-induced endothelial cell injury and explore the underlying mechanisms. In this study, human umbilical vein endothelial cells (HUVECs) were pre-treated with luteolin followed by hydrogen peroxide induction (H2O2). Our results showed that luteolin protected against H2O2-induced oxidative stress and ameliorated ROS and superoxide generation. In addition, we found that luteolin treatment inhibited the H2O2-induced membrane assembly of NADPH oxidase subunits, which was further confirmed by specifically inhibiting NADPH oxidase using DPI treatment. Furthermore, pAMPK protein expression was enhanced and p-PKC isoforms were significantly down-regulated by luteolin treatment in a dose-dependent manner, and a similar effect was observed upon DPI treatment. However, co-treatment with the specific inhibitor of AMPK (Compound C) restored p-PKC levels suggesting the role of AMPK signaling in regulating p-PKC expression under oxidative stress condition in HUVECs. Finally, we confirmed using siRNAs and specific inhibitor and/or activator of AMPK (AICAR) that luteolin treatment induced AMPK is a key player and regulator of activated expression of PKC isoforms and thereby confers protection against H2O2-induced oxidative stress in HUVECs.

17ß-Estradiol and/or estrogen receptor alpha signaling blocks protein phosphatase 1 mediated ISO induced cardiac hypertrophy.

Earlier studies have shown that estrogen possess protective function against the development of pathological cardiac hypertrophy. However, the molecular mechanisms of estrogens (E2) protective effect are poorly understood. Additionally, abnormal activation of ß-adrenergic signaling have been implicated in the development of pathological cardiac remodeling. However, the role of serine/threonine protein phosphatase 1 (PP1) in pathological cardiac remodeling under the influence of ß-adrenergic signaling have been sparsely investigated. In this study, we assessed the downstream effects of abnormal activation of PP1 upon isoproterenol (ISO) induced pathological cardiac changes. We found that pre-treatment of 17ß-estradiol (E2), tet-on estrogen receptor-α, or both significantly inhibited ISO-induced increase in cell size, hypertrophy marker gene expression and cytosolic calcium accumulation in H9c2 cells. Additionally, treatment with estrogen receptor inhibitor (ICI) reversed those effects, implicating role of E2 in inhibiting pathological cardiac remodeling. However, specific inhibition of ERα using melatonin, reduced ISO-induced PP1c expression and enhanced the level of ser-16 phosphorylated phospholamban (PLB), responsible for regulation of sarcoplasmic reticulum Ca2+-ATPase (SERCA) activity. Furthermore, hypertrophic effect caused by overexpression of PP1cα was reduced by treatment with specific inhibitor of ERα. Collectively, we found that estrogen and estrogen receptor-α have protective effect against pathological cardiac changes by suppressing PP1 expression and its downstream signaling pathway, which further needs to be elucidated.

GABA tea attenuates cardiac apoptosis in spontaneously hypertensive rats (SHR) by enhancing PI3K/Akt-mediated survival pathway and suppressing Bax/Bak dependent apoptotic pathway.

Cardiomyocyte apoptosis is the major risk factor for the development of heart failure (HF). The purpose of this study was to evaluate the effects of Gamma-aminobutyric acid (GABA) tea on hypertension-induced cardiac apoptotic pathways in spontaneously hypertensive rats (SHR). In order to reveal the mechanisms, 36 male SHR at eight weeks of age, 200 g were divided into six groups. One group was fed water as a control group. Other rats were administered one of the following treatments: GABA tea at dose 150 and 300 mg/kg/day as low GABA tea (LGT) and high GABA tea (HGT) groups, respectively, pure GABA at dose 150 and 300 mg/kg/day as LG and HG groups, respectively, green tea (GT) as control of LGT and HGT groups. After 12 weeks, cardiac tissues were analyzed by histological analysis, western blotting, and TUNEL assays. GABA tea, GT, and pure GABA decreased hypertension-induced cardiac abnormalities, including abnormal myocardial architecture. In addition, GABA tea, GT, and pure GABA dramatically increased anti-apoptotic protein, Bcl2. Furthermore, GABA tea, GT, and pure GABA also decreased activated-caspase 9 and activated-caspase 3. Additionally, the survival associated protein IGF-I and PI3K/Akt were enhanced in cardiac tissues upon treatment. Our results showed an optimistic anti-apoptotic and pro-survival effects of GABA tea treatment against hypertensive rat hearts.

Synergistic effect of HIF-1α and FoxO3a trigger cardiomyocyte apoptosis under hyperglycemic ischemia condition.

Cardiomyocyte death is an important pathogenic feature of ischemia and heart failure. Through this study, we showed the synergistic role of HIF-1α and FoxO3a in cardiomyocyte apoptosis subjected to hypoxia plus elevated glucose levels. Using gene specific small interfering RNAs (siRNA), semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR), Western blot, immunofluorescence, nuclear and cytosolic localization and TUNEL assay techniques, we determined that combined function of HIF-1α and FoxO3a under high glucose plus hypoxia condition lead to enhanced expression of BNIP3 inducing cardiomyocyte death. Our results highlighted the importance of the synergistic role of HIF-1α and FoxO3a in cardiomyocyte death which may add insight into therapeutic approaches to pathophysiology associated with ischemic diabetic cardiomyopathies.

Evaluation of the solid-phase extraction (SPE) cartridge method in combination with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) for the analysis of different VOCs in liquid matrices in varying pH conditions.

In this study, the solid-phase extraction (SPE) method combined with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method is evaluated for the analysis of liquid-phase volatile organic compounds (LVOCs). Calibration experiments were performed on a number of polar and nonpolar LVOCs (including aromatic compounds, ester, ketones, and alcohol) as a function of solution pH. If the relative sensitivity of the SPE-TD-GC-MS method is compared between different VOCs across a wide range of pH (1, 4, 7, 10, and 13), optimum sensitivities for most VOCs are derived at the neutral pH. However, there were some exceptions to the general trend with the maximum sensitivity occurring either at a moderately basic pH (methyl isobutyl ketone and butyl acetate) or extremely acidic conditions (isobutyl alcohol). It was also noticed that the relative ordering of sensitivity was changed, as the pH conditions of the solution vary. The use of internal standard (IS: chlorobenzene) resulted in a notable improvement in both relative sensitivity and reproducibility for most compounds.

A combined application of thermal desorber and gas chromatography to the analysis of gaseous carbonyls with the aid of two internal standards.

In this study, a series of GC calibration experiments were conducted to examine the feasibility of the thermal desorption approach for the quantification of five carbonyl compounds (acetaldehyde, propionaldehyde, butyraldehyde, isovaleraldehyde, and valeraldehyde) in conjunction with two internal standard compounds. The gaseous working standards of carbonyls were calibrated with the aid of thermal desorption as a function of standard concentration and of loading volume. The detection properties were then compared against two types of external calibration data sets derived by fixed standard volume and fixed standard concentration approach. According to this comparison, the fixed standard volume-based calibration of carbonyls should be more sensitive and reliable than its fixed standard concentration counterpart. Moreover, the use of internal standard can improve the analytical reliability of aromatics and some carbonyls to a considerable extent. Our preliminary test on real samples, however, indicates that the performance of internal calibration, when tested using samples of varying dilution ranges, can be moderately different from that derivable from standard gases. It thus suggests that the reliability of calibration approaches should be examined carefully with the considerations on the interactive relationships between the compound-specific properties and the operation conditions of the instrumental setups.

Determination of hazardous VOCs and nicotine released from mainstream smoke by the combination of the SPME and GC-MS methods.

In this study, the contents of nicotine and volatile organic compounds (VOCs) in mainstream smoke (MSS) were analyzed using samples of four cigarette types consisting of two common brands (R and E) with full (F) and light (L) flavor, coded with R-F, R-L, E-F, and E-L. These cigarettes were also analyzed after removing the filter portions with the assignment of a new sample code of (N) as the third letter (e.g., R-L-N). A total of 44 VOCs (including nicotine) were quantified by the combination of the SPME and GC-MS methods. Out of the 44 VOCs, 10 were identified as hazardous air pollutants listed by the U.S. EPA, while their concentrations exceeded the reference exposure limits set by various agencies. A clear distinction was apparent in the concentration levels of VOCs between different brands or between full and light flavors. Nicotine concentrations varied greatly between different cigarettes types of the R brand, whereas such changes were insignificant in the counterpart E brand. This thus suggests that light-flavor cigarettes do not necessarily guarantee low doses of carcinogens (and tar) than regular cigarettes, as their differences can be balanced by the inhaling behavior of the smoker.

Comparative analysis of odorous volatile organic compounds between direct injection and solid-phase microextraction: development and validation of a gas chromatography-mass spectrometry-based methodology.

In this study, the feasibility of GC-MS was evaluated for the quantification of odorous volatile organic compounds (VOCs) in environmental samples. These included methyl ethyl ketone, isobutyl alcohol, methyl isobutyl ketone, and butyl acetate plus benzene, toluene, and xylene (BTX). For this purpose, the gaseous standard for these VOCs were analyzed by GC-MS with the aid of both direct injection (DI) into the GC injector and solid-phase microextraction (SPME). The liquid phase standard prepared independently was tested additionally by the DI method as a reference to gaseous calibration. The detection limit (DL) values, when tested for basic quality assurance in this study, showed large differences between DI (0.002-0.007 ng) and SPME method (1.03-1.81 ng) in terms of absolute mass. The DL values, when expressed in terms of concentration (v/v), showed considerable improvement in SPME (below 0.40 nmol mol(-1)) relative to the DI method (approximately 6-15 nmol mol(-1)). The reliability of the GC-MS method was further validated through an analysis of real environmental samples collected from an industrial area.