Activation of AKT/mammalian target of rapamycin signaling in the peripheral blood of women with premature ovarian insufficiency and its correlation with FMR1 expression.

BACKGROUND: The protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway regulates early follicular activation and follicular pool maintenance in female germline cells. Fragile X mental retardation 1 (FMR1) regulates folliculogenesis and it is variably expressed in patients with Premature Ovary Insufficiency. FMR1 expression is supposed to be linked to AKT/mTOR signaling in an ovarian response dependent manner as demonstrated in recent in vitro and in vivo studies in the female germline in vitro and in vivo. METHODS: We evaluated changes in the expression of AKT/mTOR signaling pathway genes by real time PCR in the peripheral blood of 74 patients with Premature Ovarian Insufficiency and 56 fertile controls and correlated their expression with FMR1 expression. RESULTS: Expression of the genes AKT1, TSC2, mTOR, and S6K was significantly more abundant in patients with POI than in the controls. For AKT1, TSC2 and mTOR, gene expression was not affected by FMR1-CGG repeat number in the 5´-untranslated region. FMR1 and S6K expression levels, however, were significantly upregulated in patients with POI and an FMR1 premutation. Independent of a premutation, expression of mTOR, S6K, and TSC2 was significantly correlated with that of FMR1 in all patients. Furthermore, when grouped according to ovarian reserve, this effect remained significant only for mTOR and S6K, with higher significance note in patients with Premature Ovarian Insufficiency than in the controls. CONCLUSIONS: In Premature ovarian insufficiency patients, activation of AKT/mTOR signaling pathway is remarkable and putatively pathognomonic. Additionally, it seems to be triggered by an FMR1/mTOR/S6K linkage mechanism, most relevant in premutation carriers.

Abnormal platelet amyloid-ß precursor protein metabolism in SAMP8 mice: Evidence for peripheral marker in Alzheimer's disease.

Senescence-accelerated mouse strains have proved to be an accelerated-aging model, which mimics numerous features with Alzheimer's disease (AD). Three, six, and nine-month senescence-accelerated resistant 1 and senescence-accelerated prone 8 (SAMP8) mice were used in the current study, to unravel potential mechanisms for dementia and explore new diagnostic approaches for AD. The amyloid-ß (Aß40) and Aß42 levels were elevated in hippocampi and platelets from SAMP8, along with a reduced α-secretase expression and an enhanced ß-secretase expression extent with age, compared to control mice. Furthermore, hippocampal Aß40 and Aß42 of SAMP8 were positively correlated with platelet of these mice with aging progression. In addition, ß-γ-secretase-modulated proteolytic proceeding of amyloid precursor protein in platelet might work through the PI3K/Akt/GSK3ß pathway. These results indicate that platelet could be a potential early marker in the periphery to study the age-correlative aggregation of the amyloid-ß peptide in patients with AD, while still requiring the considerable study.

Sin1 (Stress-Activated Protein Kinase-Interacting Protein) Regulates Ischemia-Induced Microthrombosis Through Integrin αIIbß3-Mediated Outside-In Signaling and Hypoxia Responses in Platelets.

Objective- Microthrombosis as a serious consequence of myocardial infarction, impairs the microvascular environment and increases the occurrences of heart failure, arrhythmia, and death. Sin1 (stress-activated protein kinase-interacting protein) as an essential component of mTORC2 (mammalian target of rapamycin complex 2) is required for cell proliferation and metabolism in response to nutrients, stress, and reactive oxygen species and activates Akt and PKC (protein kinase C). However, the activation and function of Sin1/mTORC2 in ischemia-induced microthrombosis remain poorly understood. Approach and Results- The phosphorylation of the mTORC2 target Akt at S473 (serine 473) was significantly elevated in platelets from the distal end of left anterior descending obstructions from patients who underwent off-pump coronary artery bypass grafting compared with platelets from healthy subjects. Consistent with this finding, phosphorylation of T86 in Sin1 was also dramatically increased. Importantly, the augmented levels of phosphorylated Sin1 and Akt in platelets from 61 preoperative patients with ST-segment-elevation myocardial infarction correlated well with the no-reflow phenomena observed after revascularization. Platelet-specific Sin1 deficiency mice and Sin1 T86 phosphorylation deficiency mice were established to explore the underlying mechanisms in platelet activation. Mechanistically, Sin1 T86 phosphorylation amplifies mTORC2-mediated downstream signals; it is also required for αIIbß3-mediated outside-in signaling and plays a role in generating hypoxia/reactive oxygen species through NAD+/Sirt3 (sirtuin 3)/SOD2 (superoxide dismutase 2) pathway. Importantly, Sin1 deletion in platelets protected mice from ischemia-induced microvascular embolization and subsequent heart dysfunction in a mouse model of myocardial infarction. Conclusions- Together, the results of our study reveal a novel role for Sin1 in platelet activation. Thus, Sin1 may be a valuable therapeutic target for interventions for ischemia-induced myocardial infarction deterioration.

Circulating microRNAs in human obesity: a systematic review.

Context: Differential expression profiles of microRNAs have been reported in human obesity suggesting a miRNAs role in the development of obesity and associated disorders. Objective: To review circulating microRNAs (c-miRNAs) dysregulated in human obesity and to predict their possible target genes. Methods: We performed a systematic review on PubMed database (PROSPERO, CRD42017077742) for original works on c-miRNAs and human obesity and recorded c-miRNAs with differential expression profiles. Potential target genes and metabolic pathways for dysregulated miRNAs with at least two independent reports were searched using bioinformatic tools. Results: Twenty-two c-miRNAs are overexpressed, nine underexpressed and two c-miRNAs dysregulated in both directions in people with obesity compared to lean controls. Bioinformatic analyses suggest these c-miRNAs target on genes associated with fatty acid metabolism and PI3k/Akt pathway. Conclusion: Literature records 33 c-miRNAs confirmedly dysregulated in human obesity. Their predicted target genes are involved in pathways that could explain the development of obesity and its comorbidities. Further research will clarify the role of these miRNAs on metabolic diseases and their usefulness for the prognosis, prevention and treatment of obesity.

Inducible T-cell co-stimulators regulate the proliferation and invasion of human hepatocellular carcinoma HepG2 cells.

BACKGROUND: This study determined the regulatory effects of inducible T-cell co-stimulators (ICOS) in human hepatocellular carcinoma HepG2 cells using a RNA interference (RNAi) technique. METHODS: A RNAi technique was used to knockdown the expression of ICOS. ICOS expression after knockdown was detected as mRNA and protein levels by RT-PCR and Western blot, respectively. A MTT colorimetric assay was used to detect cell proliferation, and the Transwell assay was used to detect cell invasion. Western blot was carried out to detect the level of Bcl-2, AKT, and PI3K protein expression in different groups. RESULTS: The proliferation of HepG2 cells were significantly decreased after ICOS siRNA transfection (EG group). Similarly, the results of the Transwell experiment showed that invasion of HepG2 cells in the EG group was clearly reduced compared to the negative control (NC) and blank control groups (CON). Western blot analysis showed that knockdown of ICOS expression reduced the levels of Bcl-2 and AKT, and also significantly up-regulated the level of PI3K phosphorylation (P < 0.01). CONCLUSION: Down-regulating ICOS expression in HepG2 cells suppressed cell proliferation and invasion. The underlying mechanism may be related to the expression of the downstream factor, PI3K/AKT.

Characterization of thrombosis in patients with Proteus syndrome.

Patients with overgrowth and complex vascular malformation syndromes, including Proteus syndrome have an increased risk of thromboembolism. Proteus syndrome is a mosaic, progressive overgrowth disorder involving vasculature, skin, and skeleton, and caused by a somatic activating mutation in AKT1. We conducted a comprehensive review of the medical histories and hematologic evaluations of 57 patients with Proteus syndrome to identify potential risk factors for thrombosis. We found that six of ten patients, who were deceased, died secondary to deep venous thrombosis and/or pulmonary embolism. Of the remaining 47 living patients, six had thromboembolic events that all occurred postoperatively and in an affected limb. Eleven of 21 patients had an abnormal hypercoagulable panel including Factor V Leiden heterozygotes, antithrombin III deficiency, positive lupus anticoagulant, or Protein C or S deficiencies. We observed that eight of 17 patients had an abnormal D-dimer level >0.5 mcg/dl, but deep venous thromboses occurred in only four of those with D-dimer >1.0 mcg/dl. We conclude that the predisposition to thrombosis is likely to be multifaceted with risk factors including vascular malformations, immobility, surgery, additional prothrombotic factors, and possible pathophysiologic effects of the somatic AKT1 mutation on platelet function or the vascular endothelium. The D-dimer test is useful as a screen for thromboembolism, although the screening threshold may need to be adjusted for patients with this disorder. We propose developing a registry to collect D-dimer and outcome data to facilitate adjustment of the D-dimer threshold for Proteus syndrome and related disorders, including PIK3CA-Related Overgrowth Spectrum.

Modified lingguizhugan decoction incorporated with dietary restriction and exercise ameliorates hyperglycemia, hyperlipidemia and hypertension in a rat model of the metabolic syndrome.

BACKGROUND: Modified Lingguizhugan Decoction (MLD) came from famous Chinese medicine Linggui Zhugan Decoction. The MLD is used for the treatment of metabolic syndrome in the clinical setting. Our study focuses on the comprehensive treatment of MLD incorporated with dietary restriction and exercise in a rat model of the metabolic syndrome (MS). METHODS: Rats were divided into five groups: control group (Cont), high-fat diet group (HFD), high-fat diet incorporated with dietary restriction group (HFD-DR), exercise incorporated with dietary restriction group (HFD-DR-Ex) and MLD incorporated with dietary restriction and exercise group (HFD-DR-Ex-MLD). Treatments were conducted for 1 week after feeding high-fat diet for 12 weeks. The effects of treatments on high fat diet-induced obesity, hyperglycemia, hyperlipidemia, hypertension, hepatic injury and insulin resistance in rats of MS were examined. In addition, the tumor necrosis factor-α (TNF-α), leptin and protein kinase B (PKB) in rats serum and liver were also examined by enzyme-linked immunosorbent assay (ELISA). RESULTS: After a week's intervention by dietary restriction, dietary restriction incorporated with exercise or MLD, compared with HFD rats, the relative weight of liver and fat, levels of triglyceride, total cholesterol, low-density lipoprotein, free fatty acid, aspartate aminotransferase, glutamic-pyruvic transaminase and alkaline phosphatase, insulin, were significantly decreased (p < 0.05 or 0.01). This treatment also inhibited abnormal increases of TNF-α, leptin and PKB in serum and liver. CONCLUSION: MLD incorporated with dietary restriction and exercise treatment exhibit effects in alleviating high-fat diet-induced obesity, hyperglycemia, hyperlipidemia, hypertension, hepatic injury and insulin resistance, which are possibly due to the down-regulation of TNF-α, leptin and PKB.

AKT1 (E17K) mutation profiling in breast cancer: prevalence, concurrent oncogenic alterations, and blood-based detection.

BACKGROUND: The single hotspot mutation AKT1 [G49A:E17K] has been described in several cancers, with the highest incidence observed in breast cancer. However, its precise role in disease etiology remains unknown. METHODS: We analyzed more than 600 breast cancer tumor samples and circulating tumor DNA for AKT1 (E17K) and alterations in other cancer-associated genes using Beads, Emulsions, Amplification, and Magnetics digital polymerase chain reaction technology and targeted exome sequencing. RESULTS: Overall AKT1 (E17K) mutation prevalence was 6.3 % and not correlated with age or menopausal stage. AKT1 (E17K) mutation frequency tended to be lower in patients with grade 3 disease (1.9 %) compared with those with grade 1 (11.1 %) or grade 2 (6 %) disease. In two cohorts of patients with advanced metastatic disease, 98.0 % (n = 50) and 97.1 % (n = 35) concordance was obtained between tissue and blood samples for the AKT1 (E17K) mutation, and mutation capture rates of 66.7 % (2/3) and 85.7 % (6/7) in blood versus tissue samples were observed. Although AKT1-mutant tumor specimens were often found to harbor concurrent alterations in other driver genes, a subset of specimens harboring AKT1 (E17K) as the only known driver alteration was also identified. Initial follow-up survival data suggest that AKT1 (E17K) could be associated with increased mortality. These findings warrant additional long-term follow-up. CONCLUSIONS: The data suggest that AKT1 (E17K) is the most likely disease driver in certain breast cancer patients. Blood-based mutation detection is achievable in advanced-stage disease. These findings underpin the need for a further enhanced-precision medicine paradigm in the treatment of breast cancer.

Vav3 is linked to poor prognosis of pancreatic cancers and promotes the motility and invasiveness of pancreatic cancer cells.

BACKGROUND/OBJECTIVES: The aim of this study was to investigate the role of the guanine nucleotide exchange factor Vav3 in the motility and invasiveness of pancreatic ductal adenocarcinoma (PDAC) cells. METHODS: Immunohistochemistry was used to determine whether high Vav3 expression in human PDAC tissues is correlated with poor prognosis. Immunocytochemistry was used to determine the association and intracellular distribution of Vav3, Rac1 and Akt in PDAC cells. Phosphoprotein array analysis was performed to determine the Vav3-associated intracellular signaling pathways. Immunocytochemistry and Matrigel invasion assays were used to examine the effects of Vav3 on the formation of cell protrusions and PDAC cell invasion. RESULTS: Expression of Vav3 in PDAC tissue was significantly correlated with overall survival. Vav3 was localized in cell protrusions of migrating PDAC cells. Knockdown of Vav3 inhibited the motility and invasiveness of PDAC cells through a decrease in cell protrusions. The levels of active Rac1 or active Akt were not associated with the concentration of Vav3 in cell protrusions. The Vav3-dependent promotion of motility and invasiveness was not modulated by Rac1 or Akt. Additionally, knockdown of Vav3 increased phosphorylated WNK1 in PDAC cells, and knockdown of WNK1 inhibited the motility and invasiveness. This study suggests that Vav3 can be a useful marker for predicting the outcome of patients with PDAC and that Vav3 can promote PDAC cell motility and invasion through association with dephosphorylation of WNK1. CONCLUSIONS: Vav3 was accumulated in cell protrusions, contributed to the formation of membrane protrusions, and thereby increased the motility and invasiveness of PDAC cells.

Thymidine phosphorylase participates in platelet signaling and promotes thrombosis.

RATIONALE: Platelets contain abundant thymidine phosphorylase (TYMP), which is highly expressed in diseases with high risk of thrombosis, such as atherosclerosis and type II diabetes mellitus. OBJECTIVE: To test the hypothesis that TYMP participates in platelet signaling and promotes thrombosis. METHODS AND RESULTS: By using a ferric chloride (FeCl3)-induced carotid artery injury thrombosis model, we found time to blood flow cessation was significantly prolonged in Tymp(-/-) and Tymp(+/-) mice compared with wild-type mice. Bone marrow transplantation and platelet transfusion studies demonstrated that platelet TYMP was responsible for the antithrombotic phenomenon in the TYMP-deficient mice. Collagen-, collagen-related peptide-, adenosine diphosphate-, or thrombin-induced platelet aggregation were significantly attenuated in Tymp(+/-) and Tymp(-/-) platelets, and in wild type or human platelets pretreated with TYMP inhibitor KIN59. Tymp deficiency also significantly decreased agonist-induced P-selectin expression. TYMP contains an N-terminal SH3 domain-binding proline-rich motif and forms a complex with the tyrosine kinases Lyn, Fyn, and Yes in platelets. TYMP-associated Lyn was inactive in resting platelets, and TYMP trapped and diminished active Lyn after collagen stimulation. Tymp/Lyn double haploinsufficiency diminished the antithrombotic phenotype of Tymp(+/-) mice. TYMP deletion or inhibition of TYMP with KIN59 dramatically increased platelet-endothelial cell adhesion molecule 1 tyrosine phosphorylation and diminished collagen-related peptide- or collagen-induced AKT phosphorylation. In vivo administration of KIN59 significantly inhibited FeCl3-induced carotid artery thrombosis without affecting hemostasis. CONCLUSIONS: TYMP participates in multiple platelet signaling pathways and regulates platelet activation and thrombosis. Targeting TYMP might be a novel antiplatelet and antithrombosis therapy.

Extracellular cyclophilin A activates platelets via EMMPRIN (CD147) and PI3K/Akt signaling, which promotes platelet adhesion and thrombus formation in vitro and in vivo.

OBJECTIVE: Cyclophilin A (CyPA) is secreted under inflammatory conditions by various cell types. Whereas the important role of intracellular CyPA for platelet function has been reported, the effect of extracellular CyPA on platelet function has not been investigated yet. APPROACH AND RESULTS: Inhibition of extracellular CyPA through a novel specific inhibitor MM284 reduced thrombus after ferric chloride-induced injury in vivo. In vitro extracellular CyPA enhanced thrombus formation even in CyPA(-/-) platelets. Treatment of isolated platelets with recombinant CyPA resulted in platelet degranulation in a time- and dose-dependent manner. Inhibition of the platelet surface receptor extracellular matrix metalloproteinase inducer (cluster of differentiation 147) by an anticluster of differentiation 147 monoclonal antibody significantly reduced CyPA-dependent platelet degranulation. Pretreatment of platelets with CyPA enhanced their recruitment to mouse carotid arteries after arterial injury, which could be inhibited by an anticluster of differentiation 147 monoclonal antibody (intravital microscopy). The role of extracellular CyPA in adhesion could be confirmed by infusing CyPA(-/-) platelets in CyPA(+/+) mice and by infusing CyPA(+/+) platelets in CyPA(-/-) mice. Stimulation of platelets with CyPA induced phosphorylation of Akt, which could in turn be inhibited in the presence of phosphoinositid-3-kinase inhibitors. Akt-1(-/-) platelets revealed a markedly decreased degranulation on CyPA stimulation. Finally, ADP-induced platelet aggregation was attenuated by MM284, as well as by inhibiting paracrine-secreted CyPA without directly affecting Ca(2+)-signaling. CONCLUSIONS: Extracellular CyPA activates platelets via cluster of differentiation 147-mediated phosphoinositid-3-kinase/Akt-signaling, leading to enhanced adhesion and thrombus formation independently of intracellular CyPA. Targeting extracellular CyPA via a specific inhibitor may be a promising strategy for platelet inhibition without affecting critical functions of intracellular CyPA.

PI3K, AKT, and P-AKT levels in thin endometrium.

The aim of this study was to explore the expression of PI3K, AKT, and P-AKT, and to investigate the role of PI3K/AKT signaling pathway in thin endometrium. We included 40 women treated in affiliated Shenzhen Nanshan People's Hospital of Guangdong Medical University for endometrial conditions between August 2013 and January 2015, 20 with a normal endometrium, and 20 with thin endometrium. The expression of PI3K, AKT, and P-AKT was evaluated by the immunohistochemical S-P method. The expression of PI3K, AKT, and P-AKT proteins was significantly lower in the thin endometrium group than in the normal endometrium group (P < 0.05). The expression of PI3K and AKT was positively correlated with the expression of P-AKT. The expression of PI3K, AKT, and P-AKT proteins in the thin endometrium decreases during the proliferative phase, and this process could be associated with PI3K/AKT signaling.

Engagement of platelet toll-like receptor 9 by novel endogenous ligands promotes platelet hyperreactivity and thrombosis.

RATIONALE: A prothrombotic state and increased platelet reactivity are common in pathophysiological conditions associated with oxidative stress and infections. Such conditions are associated with an appearance of altered-self ligands in circulation that can be recognized by Toll-like receptors (TLRs). Platelets express a number of TLRs, including TLR9; however, the role of TLR in platelet function and thrombosis is poorly understood. OBJECTIVE: To investigate the biological activities of carboxy(alkylpyrrole) protein adducts, an altered-self ligand generated in oxidative stress, on platelet function and thrombosis. METHODS AND RESULTS: In this study we show that carboxy(alkylpyrrole) protein adducts represent novel unconventional ligands for TLR9. Furthermore, using human and murine platelets, we demonstrate that carboxy(alkylpyrrole) protein adducts promote platelet activation, granule secretion, and aggregation in vitro and thrombosis in vivo via the TLR9/MyD88 pathway. Platelet activation by TLR9 ligands induces IRAK1 and AKT phosphorylation, and it is Src kinase-dependent. Physiological platelet agonists act synergistically with TLR9 ligands by inducing TLR9 expression on the platelet surface. CONCLUSIONS: Our study demonstrates that platelet TLR9 is a functional platelet receptor that links oxidative stress, innate immunity, and thrombosis.

Protein kinase C δ deficiency enhances megakaryopoiesis and recovery from thrombocytopenia.

OBJECTIVE: We previously determined that protein kinase C δ (PKCδ) regulates platelet function. However, the function of PKCδ in megakaryopoiesis is unknown. APPROACH AND RESULTS: Using PKCδ(-/-) and wild-type littermate mice, we found that deficiency of PKCδ caused an increase in white blood cells and platelet counts, as well as in bone marrow and splenic megakaryocytes (P<0.05). Additionally, the megakaryocyte number and DNA content were enhanced in PKCδ(-/-) mouse bone marrow after culturing with exogenous thrombopoietin compared with wild-type (P<0.05). Importantly, thrombopoietin-induced signaling was also altered with PKCδ deletion because both extracellular signal-regulated kinase and Akt308 phosphorylation were heightened in PKCδ(-/-) megakaryocytes compared with wild-type. Finally, PKCδ(-/-) mice recovered faster and had a heightened rebound thrombocytosis after thrombocytopenic challenge. CONCLUSIONS: These data suggest that PKCδ is an important megakaryopoietic protein, which regulates signaling induced by thrombopoietin and represents a potential therapeutic target.

Long-term effect of early postnatal overnutrition on insulin resistance and serum fatty acid profiles in male rats.

BACKGROUND: Increasing evidence suggests that overnutrition during the early postnatal period, a critical window of development, increases the risk of adult-onset obesity and insulin resistance. In this study, we investigated the impact of overnutrition during the suckling period on body weight, serum biochemistry and serum fatty acid metabolomics in male rats. METHODS: Rats raised in small litters (SL, 3 pups/dam) and normal litters (NL, 10 pups/dam) were used to model early postnatal overnutrition and control, respectively. Serum glucose, triglyceride, high-density lipoprotein-cholesterol, free fatty acid, insulin and leptin concentrations were assayed using standard biochemical techniques. Serum fatty acids were identified and quantified using a gas chromatography-mass spectrometry-based metabolomic approach. mRNA and protein levels of key components of the insulin receptor signaling pathway were measured in epididymal fat and gastrocnemius muscle by quantitative PCR and western blotting. RESULTS: SL rats were 37.3 % and 15.1 % heavier than NL rats at weaning and 16-weeks-old, respectively. They had increased visceral fat mass, adult-onset insulin resistance and glucose intolerance as well as elevated serum levels of free fatty acids and triglycerides. All detectable fatty acids were elevated in the serum of SL pups at weaning compared to NL controls, and significant increases in the levels of four fatty acids (palmitic acid, palmitoleic acid, oleic acid and arachidonic acid) persisted into adulthood. Moreover, a significantly positive correlation was identified between an insulin resistance index (HOMA-IR) and concentrations of myristic, palmitic, palmitoleic and oleic acid in serum at postnatal 16 weeks. Early postnatal overnutrition also resulted in a significant downregulation of insulin receptor substrate-1 (Irs-1), protein kinase B (Akt2) and glucose transporter 4 (Glut4) at the protein level in epididymal fat of SL rats at 16 weeks, accompanied by decreased mRNA levels for Irs-1 and Glut4. In gastrocnemius muscle, Akt2 and Glut4 mRNA and Glut4 protein levels were significantly decreased in SL rats. CONCLUSIONS: This study demonstrates that early postnatal overnutrition can have long-lasting effects on body weight and serum fatty acid profiles and can lead to impaired insulin signaling pathway in visceral white adipose tissue and skeletal muscle, which may play a major role in IR.

Lower Hydrogen Sulfide Is Associated with Cardiovascular Mortality, Which Involves cPKCßII/Akt Pathway in Chronic Hemodialysis Patients.

BACKGROUND/AIMS: To evaluate the relationship between plasma hydrogen sulfide (H2S) and cardiovascular risk markers, including pulse pressure (PP), left ventricular mass index (LVMI) and intima-media thickness (IMT), and mortality in chronic hemodialysis (CHD) patients and further investigate the underlying cardiovascular protection mechanism of H2S. METHODS: CHD patients, 113 of them, were studied. Plasma H2S was measured through zinc acetate reaction. cPKCßII membrane translocation and phosphorylation of Akt were detected by western blot. RESULTS: Lower plasma H2S level in CHD patients was predictor of an increased PP, LVMI and IMT. Patients with lower H2S had a lower survival at the end of the study. H2S was an independent predictor of all-cause and cardiovascular mortality when adjusted for other risk factors. CHD patients with lower H2S showed an increase of cPKCßII activation, but phosphorylation of Akt decreased. The level of VCAM-1 and ICAM-1 increased significantly. CONCLUSIONS: Lower plasma H2S in CHD patients is associated with cardiovascular risk factors and mortality, which may be mediated by the cPKCßII/Akt pathway and further VCAM-1/ICAM-1 upregulation.

Tangeretin regulates platelet function through inhibition of phosphoinositide 3-kinase and cyclic nucleotide signaling.

OBJECTIVE: Dietary flavonoids have long been appreciated in reducing cardiovascular disease risk factors, but their mechanisms of action are complex in nature. In this study, the effects of tangeretin, a dietary flavonoid, were explored on platelet function, signaling, and hemostasis. APPROACH AND RESULTS: Tangeretin inhibited agonist-induced human platelet activation in a concentration-dependent manner. It inhibited agonist-induced integrin αIIbß3 inside-out and outside-in signaling, intracellular calcium mobilization, and granule secretion. Tangeretin also inhibited human platelet adhesion and subsequent thrombus formation on collagen-coated surfaces under arterial flow conditions in vitro and reduced hemostasis in mice. Further characterization to explore the mechanism by which tangeretin inhibits platelet function revealed distinctive effects of platelet signaling. Tangeretin was found to inhibit phosphoinositide 3-kinase-mediated signaling and increase cGMP levels in platelets, although phosphodiesterase activity was unaffected. Consistent with increased cGMP levels, tangeretin increased the phosphorylation of vasodilator-stimulated phosphoprotein at S239. CONCLUSIONS: This study provides support for the ability and mechanisms of action of dietary flavonoids to modulate platelet signaling and function, which may affect the risk of thrombotic disease.

Postprandial activation of metabolic and inflammatory signalling pathways in human peripheral mononuclear cells.

High-fat, high-carbohydrate (HFHC) meals induce an inflammatory response in mononuclear cells (MNC). Here, we studied the interaction between metabolic and inflammatory signalling pathways by the measurement of postprandial effects of three different test meals on intracellular Akt, S6 kinase (S6K)/mammalian target of rapamycin and NF-κB signalling in human MNC. We recruited six healthy, lean individuals. Each individual ingested three different meals in the morning separated by at least 3 d: a HFHC meal; an oral lipid-tolerance test meal; a healthy breakfast. Blood samples were obtained before and 1, 2, 4, 6 and 8 h after ingestion. Plasma insulin and IL-6 levels were measured. Intracellular metabolic and inflammatory signalling pathways were assessed by measuring the phosphorylation of Akt kinase and S6K, the degradation of inhibitory κB-α (IκB-α) protein and the DNA binding activity of NF-κB in MNC. mRNA expression levels of the Akt and NF-κB target genes Mn superoxide dismutase (MnSOD), CC-chemokine-receptor 5 (CCR5), intercellular adhesion molecule 1 (ICAM-1) and plasminogen activator inhibitor-1 (PAI-1) were measured by quantitative RT-PCR. We found a positive correlation of Akt phosphorylation with NF-κB activation (NF-κB binding activity: r 0·4500, P= 0·0003; IκB-α protein levels: r -0·5435, P< 0·0001), a negative correlation of plasma insulin levels with NF-κB binding activity (r -0·3993, P= 0·0016) and a positive correlation of plasma insulin levels with S6K activation (r 0·4786, P< 0·0001). The activation of Akt and pro-inflammatory NF-κB signalling was supported by the up-regulation of the respective target genes MnSOD and CCR5. In conclusion, the present data suggest a postprandial interaction between the metabolic and inflammatory signalling pathways Akt and NF-κB in MNC.

High-fat diet activates pro-inflammatory response in the prostate through association of Stat-3 and NF-κB.

BACKGROUND: Signal transducer and activator of transcription (Stat)-3 and nuclear factor-kappa B (NF-κB) are important signaling pathways constitutively activated during inflammation. We previously reported that high-fat diet (HFD) intake induces oxidative stress in the prostate through elevated expression of NADPH oxidase subunits causing NF-κB activation. We sought to determine whether Stat-3 is involved in the activation of NF-κB in the prostate as a result of HFD feeding, leading to inflammation. METHODS: C57BL/6 mice were either fed with regular diet (RD) or HFD for 4 and 8 weeks. Plasma cytokine levels were determined by multiplex analysis. Western blotting was performed to determine the expression of NF-κB, Stat-3, Akt, PDK1, PKCε, and their phosphorylated forms along with pathologic evaluation of the prostate. Immunoprecipitation and electrophoretic mobility shift assay (EMSA) were conducted to study the association between Stat-3 and NF-κB. RESULTS: C57BL/6 mice fed with HFD showed a significant increase in the plasma levels of IL-1ß, IL-6, IL-17, and TNFα after 4 and 8 weeks of feeding, compared with RD controls. HFD feeding elevated the intraprostatic expression of IL-6 and caused activation of PKCε and Akt, the upstream kinase regulating Stat-3 and NF-κB. Nuclear extracts from the prostates of mice fed with HFD exhibited constitutively activated levels of Stat-3 and NF-κB/p65. Increased association between the activated forms of Stat-3 and NF-κB/p65 was observed in the nucleus as a result of HFD feeding, a finding that was accompanied by morphologic evidence of increased intraprostatic inflammation. CONCLUSIONS: Our findings suggest that HFD activates Stat-3 and NF-κB/p65 in the prostate, and their interaction is associated with increased inflammation in the prostate.

Obesity, inflammation and resting energy expenditure: possible mechanism of progranulin in this pathway.

AIM: The aim of the study was to measure circulating PGRN levels and to investigate its potential correlation with resting metabolic rate and obesity related complications. Moreover, to investigate on the PGRN and some important gene expressions in energy expenditure in vitro in samples of PBMCs derived from all participants of our study in a cellular model. METHODS: Of the 163 participants who were recruited for the current cross-sectional study, 37 (22.69%) were normal weight (18.5≤BMI<25), 53 (32.51%) were overweight (25≤BMI<30), 48 (29.44%) were categorized as class I obese (BMI 30 -34.9) and 25 (15.33%) were classified as class II and III obese (BMI≥35). All participants were assessed for the measurement of RMR by means of indirect calorimetry following an overnight fasting. Body composition was analyzed with the Bioelectrical Impedance technique by the BODY COMPOSITION ANALYZER BC-418M -Tanita. The PBMCs were separated from whole blood by Ficoll-hypaque technique. Total cellular RNA was extracted and the cDNA was synthesized. This process was followed by real-time PCR using specific primer pairs for PGRN, AKT, MAPK and mRNA, and beta actin mRNA was used as the internal control. Circulating PGRN was measured with the use of ELISA method. RESULTS: The circulating levels and gene expressions of PGRN rose in parallel with the increase of body weight. However, there was significant difference in the strength of association between circulating PGRN as well as PGRN gene expression and obesity-related variables. Moreover, PGRN gene expression had significant correlation with BMI, visceral fat, MAPK and AKT gene expression. The increased mass of visceral fat in correlation with the increased PGRN levels was more pronounced in high or normal resting metabolic rate group compared with the group with low resting metabolic rate. After adjusting for BMI and gender, we found that circulating PGRN can predict the RMR/kg independent of other variables such as TG, HDL, and hs-CRP (P=0.03). CONCLUSION: PGRN associated with obesity and glucose homeostasis and may predict the resting metabolic rate levels independent of confounder factors. Experimental study may clarify the PGRN role in obesity etiology through metabolism regulation.