Fructose-1,6-bisphosphate and aldolase mediate glucose sensing by AMPK.

The major energy source for most cells is glucose, from which ATP is generated via glycolysis and/or oxidative metabolism. Glucose deprivation activates AMP-activated protein kinase (AMPK), but it is unclear whether this activation occurs solely via changes in AMP or ADP, the classical activators of AMPK. Here, we describe an AMP/ADP-independent mechanism that triggers AMPK activation by sensing the absence of fructose-1,6-bisphosphate (FBP), with AMPK being progressively activated as extracellular glucose and intracellular FBP decrease. When unoccupied by FBP, aldolases promote the formation of a lysosomal complex containing at least v-ATPase, ragulator, axin, liver kinase B1 (LKB1) and AMPK, which has previously been shown to be required for AMPK activation. Knockdown of aldolases activates AMPK even in cells with abundant glucose, whereas the catalysis-defective D34S aldolase mutant, which still binds FBP, blocks AMPK activation. Cell-free reconstitution assays show that addition of FBP disrupts the association of axin and LKB1 with v-ATPase and ragulator. Importantly, in some cell types AMP/ATP and ADP/ATP ratios remain unchanged during acute glucose starvation, and intact AMP-binding sites on AMPK are not required for AMPK activation. These results establish that aldolase, as well as being a glycolytic enzyme, is a sensor of glucose availability that regulates AMPK.

Resolvin E1 attenuates injury-induced vascular neointimal formation by inhibition of inflammatory responses and vascular smooth muscle cell migration.

Mechanical insults, such as stent implantation, can induce endothelial injury, vascular inflammation, and ultimately lead to vascular neointimal hyperplasia. Resolvin E1 (RvE1), derived from the ω3 fatty acid eicosapentaenoic acid, can facilitate the resolution of inflammation in many settings. We therefore aimed to determine if there was a role for RvE1 in preventing neointimal formation after arterial injury and to understand the underlying mechanisms. Vascular inflammation and neointimal hyperplasia were induced by wire injury in the femoral arteries of mice. Administration of exogenous RvE1 and endogenously generated RvE1 via dietary supplementation with eicosapentaenoic acid and aspirin markedly reduced vascular neointima formation in this model. Mechanistically, RvE1 was found to inhibit vascular neutrophil infiltration, promote macrophage polarization toward an M2-like phenotype, suppress T-cell trafficking by reducing RANTES secretion from vascular smooth muscle cells, and inhibit vascular smooth muscle cell migration. In summary, RvE1 demonstrated a protective role against vascular inflammation and remodeling in response to mechanical injury, suggesting that it may serve as an adjuvant therapeutic agent for percutaneous coronary interventions, such as stent implantation.-Liu, G., Gong, Y., Zhang, R., Piao, L., Li, X., Liu, Q., Yan, S., Shen, Y., Guo, S., Zhu, M., Yin, H., Funk, C. D., Zhang, J., Yu, Y. Resolvin E1 attenuates injury-induced vascular neointimal formation by inhibition of inflammatory responses and vascular smooth muscle cell migration.

T-Cell Mineralocorticoid Receptor Controls Blood Pressure by Regulating Interferon-Gamma.

RATIONALE: Hypertension remains to be a global public health burden and demands novel intervention strategies such as targeting T cells and T-cell-derived cytokines. Mineralocorticoid receptor (MR) antagonists have been clinically used to treat hypertension. However, the function of T-cell MR in blood pressure (BP) regulation has not been elucidated. OBJECTIVE: We aim to determine the role of T-cell MR in BP regulation and to explore the mechanism. METHODS AND RESULTS: Using T-cell MR knockout mouse in combination with angiotensin II-induced hypertensive mouse model, we demonstrated that MR deficiency in T cells strikingly decreased both systolic and diastolic BP and attenuated renal and vascular damage. Flow cytometric analysis showed that T-cell MR knockout mitigated angiotensin II-induced accumulation of interferon-gamma (IFN-γ)-producing T cells, particularly CD8+ population, in both kidneys and aortas. Similarly, eplerenone attenuated angiotensin II-induced elevation of BP and accumulation of IFN-γ-producing T cells in wild-type mice. In cultured CD8+ T cells, T-cell MR knockout suppressed IFN-γ expression whereas T-cell MR overexpression and aldosterone both enhanced IFN-γ expression. At the molecular level, MR interacted with NFAT1 (nuclear factor of activated T-cells 1) and activator protein-1 in T cells. Finally, T-cell MR overexpressing mice manifested more elevated BP compared with control mice after angiotensin II infusion and such difference was abolished by IFN-γ-neutralizing antibodies. CONCLUSIONS: MR may interact with NFAT1 and activator protein-1 to control IFN-γ in T cells and to regulate target organ damage and ultimately BP. Targeting MR in T cells specifically may be an effective novel approach for hypertension treatment.

Identification of a novel series of anti-inflammatory and anti-oxidative phospholipid oxidation products containing the cyclopentenone moiety in vitro and in vivo: Implication in atherosclerosis.

Oxidative stress and inflammation are two major contributing factors to atherosclerosis, a leading cause of cardiovascular disease. Oxidation of phospholipids on the surface of low density lipoprotein (LDL) particles generated under oxidative stress has been associated with the progression of atherosclerosis, but the underlying molecular mechanisms remain poorly defined. We identified a novel series of oxidation products containing the cyclopentenone moiety, termed deoxy-A2/J2-isoprostanes-phosphocholine, from 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine in vivo using mass spectrometry and by comparison to a chemically synthesized standard. Transcriptomic analysis (RNA-seq) demonstrated that these compounds affected >200 genes in bone marrow-derived macrophages, and genes associated with inflammatory and anti-oxidative responses are among the top 5 differentially expressed. To further investigate the biological relevance of these novel oxidized phospholipids in atherosclerosis, we chemically synthesized a representative compound 1-palmitoyl-2-15-deoxy-δ-12,14-prostaglandin J2-sn-glycero-3-phosphocholine (15d-PGJ2-PC) and found that it induced anti-inflammatory and anti-oxidant responses in macrophages through modulation of NF-κB, peroxisome proliferator-activated receptor γ (PPARγ), and Nrf2 pathways; this compound also showed potent anti-inflammatory properties in a mice model of LPS-induced systematic inflammatory response syndrome. Additionally, 15d-PGJ2-PC inhibited macrophage foam cell formation, suggesting a beneficial role against atherosclerosis. These properties were consistent with decreased levels of these compounds in the plasma of patients with coronary heart disease compared with control subjects. Our findings uncovered a novel molecular mechanism for the negative regulation of inflammation and positive enhancement of anti-oxidative responses in macrophages by these oxidized phospholipids in LDL in the context of atherosclerosis.

Action Recognition, Tracking, and Optimization Analysis of Training Process Based on the Support Vector Regression Model.

In order to study the action recognition, tracking, and optimization of the training process based on the support vector regression model, a method of human action recognition based on support vector machine optimization is proposed. This method uses the improved strategy of support vector machine to realize the action recognition through the human action recognition based on the optimization of the vector machine. During the recognition, the DAG SVM strategy is improved according to the recognition accuracy of the classifier, and when outputting the result, output the recognition result and the corresponding confidence level, and use the confidence level to process the recognition result. Finally, through the experimental results, it is realized that the recognition rate based on support vector optimization is 98.7%, indicating that this method is effective and can improve the accuracy and efficiency of human body action recognition.

Application of Moving Target Information Perception Technology in Intelligent Supervision System.

In order to solve the problems of inaccurate information collection, incomplete information collection, and inconsistency of collected images in traditional sports injury collection methods, an application method of moving target information perception technology in intelligent supervision system is proposed. By judging and analyzing the potential motion damage posture of the motion posture intelligent tracking images, the collected motion intelligence tracking images are judged. The intelligent tracking image matrix can make up for the shortcomings of traditional images that are not connected, complete the identification, detect potential damage in time, and take targeted preventive measures and means. Finally, according to the target detection algorithm and target tracking algorithm, combined with OpenCV computer vision library and QT image library, an intelligent video surveillance target tracking simulation system is developed. The algorithm studied in this paper is to realize the target tracking function of the intelligent video surveillance system. Through the comparison of experimental results, the design method can accurately collect damage attitude information, without calculating continuous values, and the use of three-dimensional images in the positioning process can analyze the damage attitude from multiple angles.

Follicular fluid lipidomic profiling reveals potential biomarkers of polycystic ovary syndrome: A pilot study.

Background: Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder associated with multiple metabolic conditions including obesity, insulin resistance, and dyslipidemia. PCOS is the most common cause of anovulatory infertility; however, the molecular diversity of the ovarian follicle microenvironment is not fully understood. This study aimed to investigate the follicular fluid (FF) lipidomic profiles in different phenotypes of PCOS and to explore novel lipid biomarkers. Methods: A total of 25 women with PCOS and 12 women without PCOS who underwent in vitro fertilization and embryo transfer were recruited, and their FF samples were collected for the lipidomic study. Liquid chromatography-tandem mass spectrometry was used to compare the differential abundance of FF lipids between patients with different PCOS phenotypes and controls. Subsequently, correlations between specific lipid concentrations in FF and high-quality embryo rate (HQER) were analyzed to further evaluate the potential interferences of lipid levels with oocyte quality in PCOS. Candidate biomarkers were then compared via receiver operating characteristic (ROC) curve analysis. Results: In total, 19 lipids were identified in ovarian FF. Of these, the concentrations of ceramide (Cer) and free fatty acids (FFA) in FF were significantly increased, whereas those of lysophosphatidylglycerol (LPG) were reduced in women with PCOS compared to controls, especially in obese and insulin-resistant groups. In addition, six subclasses of ceramide, FFA, and LPG were correlated with oocyte quality. Twenty-three lipid subclasses were identified as potential biomarkers of PCOS, and ROC analysis indicated the prognostic value of Cer,36:1;2, FFA C14:1, and LPG,18:0 on HQER in patients with PCOS. Conclusions: Our study showed the unique lipidomic profiles in FF from women with PCOS. Moreover, it provided metabolic signatures as well as candidate biomarkers that help to better understand the pathogenesis of PCOS.

Using a TEMPO-based fluorescent probe for monitoring oxidative stress in living cells.

Generation of too many reactive oxygen species (ROS) in relation to available antioxidants in living cells can cause oxidative stress, which is involved in the development and progression of several serious diseases. 2',7'-Dichlorodihydrofluorescein (DCFH) and its diacetate form, DCFH-DA, are widely used probes for monitoring general oxidative stress in cells, but DCFH oxidation is not always related to ROS. We report here a new method for quantifying cellular oxidative stress using a 2,2,6,6-tetramethyl- piperidine-1-oxyl (TEMPO)-based probe. We tested and verified the probe both in cell-free solutions and in living cells under conditions of increased or reduced oxidative stress. The probe revealed the oxidative stress status in living cells and may be a useful complement to DCFH fluorescent probes.

Resolvin E1 in Follicular Fluid Acts as a Potential Biomarker and Improves Oocyte Developmental Competence by Optimizing Cumulus Cells.

Metabolic profile of follicular fluid (FF) has been investigated to look for biomarkers for oocyte quality. Resolvin E1 (RvE1), a potent pro-resolving mediator, was reported to have protective action in cell function. The study aimed to examine the predictive value of RvE1 for oocyte quality and to explore the cellular mechanism of RvE1 in improving oocyte competence. Metabolic profiles of 80 FF samples showed a higher level of RvE1 in group A (blastocysts scored ≥ B3BC and B3CB according to Gardner's blastocyst scoring system, N = 36) than that of group B (blastocysts scored < B3BC and B3CB, N = 44, P = 0.0018). The receiver operating characteristic (ROC) curve analysis showed that RvE1 level in FF below 8.96 pg/ml (AUC:0.75; 95%CI: 0.64-0.86; P = 0.00012) could predict poor oocyte quality with specificity of 97.22%, suggesting RvE1 as a potential biomarker to exclude inferior oocytes. Besides, the level of RvE1 was found to be significantly lower in FF than in serum (57.49 to 17.62 pg/ml; P=.0037) and was gradually accumulated in the culture medium of cumulus cells (CCs) during cell culture, which indicated that RvE1 came from both blood exudates and local secretion. The in vitro experiment revealed thecellular mechanism of RvE1 in improvingoocyte qualityby decreasing the cumulus cellapoptotic rate and increasing cell viability and proliferation. It is the first time thatthe role of RvE1 in reproduction is explored. In conclusion, RvE1 is valuable as a potential exclusive biomarker for oocyte selection andplays a role in improving oocyte quality.

Acetaldehyde dehydrogenase 2 interactions with LDLR and AMPK regulate foam cell formation.

Acetaldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme detoxifying acetaldehyde and endogenous lipid aldehydes; previous studies suggest a protective role of ALDH2 against cardiovascular disease (CVD). Around 40% of East Asians carrying the single nucleotide polymorphism (SNP) ALDH2 rs671 have an increased incidence of CVD. However, the role of ALDH2 in CVD beyond alcohol consumption remains poorly defined. Here we report that ALDH2/LDLR double knockout (DKO) mice have decreased atherosclerosis compared with LDLR-KO mice, whereas ALDH2/APOE-DKO mice have increased atherosclerosis, suggesting an unexpected interaction of ALDH2 with LDLR. Further studies demonstrate that in the absence of LDLR, AMPK phosphorylates ALDH2 at threonine 356 and enables its nuclear translocation. Nuclear ALDH2 interacts with HDAC3 and represses transcription of a lysosomal proton pump protein ATP6V0E2, critical for maintaining lysosomal function, autophagy, and degradation of oxidized low-density lipid protein. Interestingly, an interaction of cytosolic LDLR C-terminus with AMPK blocks ALDH2 phosphorylation and subsequent nuclear translocation, whereas ALDH2 rs671 mutant in human macrophages attenuates this interaction, which releases ALDH2 to the nucleus to suppress ATP6V0E2 expression, resulting in increased foam cells due to impaired lysosomal function. Our studies reveal a novel role of ALDH2 and LDLR in atherosclerosis and provide a molecular mechanism by which ALDH2 rs671 SNP increases CVD.

Endogenous cholesterol ester hydroperoxides modulate cholesterol levels and inhibit cholesterol uptake in hepatocytes and macrophages.

Dysregulation of cholesterol metabolism represents one of the major risk factors for atherosclerotic cardiovascular disease (CVD). Oxidized cholesterol esters (oxCE) in low-density lipoprotein (LDL) have been implicated in CVD but the underlying mechanisms remain poorly defined. We use a targeted lipidomic approach to demonstrate that levels of oxCEs in human plasma are associated with different types of CVD and significantly elevated in patients with myocardial infarction. We synthesized a major endogenous cholesterol ester hydroperoxide (CEOOH), cholesteryl-13(cis, trans)-hydroperoxy-octadecadienoate (ch-13(c,t)-HpODE) and show that this endogenous compound significantly increases plasma cholesterol level in mice while decrease cholesterol levels in mouse liver and peritoneal macrophages, which is primarily due to the inhibition of cholesterol uptake in macrophages and liver. Further studies indicate that inhibition of cholesterol uptake by ch-13(c,t)-HpODE in macrophages is dependent on LXRα-IDOL-LDLR pathway, whereas inhibition on cholesterol levels in hepatocytes is dependent on LXRα and LDLR. Consistently, these effects on cholesterol levels by ch-13(c,t)-HpODE are diminished in LDLR or LXRα knockout mice. Together, our study provides evidence that elevated plasma cholesterol levels by CEOOHs are primarily due to the inhibition of cholesterol uptake in the liver and macrophages, which may play an important role in the pathogenesis of CVD.

Fatigue and physical recovery in basketball under covid-19 / Fadiga e recuperação física no basquetebol em meio a covid-19 / Fatiga y recuperación física en baloncesto en el marco de covid-19

ABSTRACT Introduction: A new research direction to strengthen basketball, improve physical function and enhance the immunity of athletes during the epidemic situation of COVID-19 is requested. Objective: Explore the specific methods of basketball fatigue and physical recovery under the outlook of COVID-19. Methods: 36 college volunteers without significant differences in height, weight, or age were randomly selected for the research. Divided into two groups, the intervention mode of the experimental group was vibration foam roller intervention, while the control group adopted the traditional walking and stretching method. The subjective assessment data of lactic acid change and exercise fatigue were collected and analyzed. Results: One hour after exercise, the rate, and decrease of lactic acid in the experimental group were statistically higher. Before the beginning of the experiment, the subjective assessment of fatigue in the control group was (16.031 ± 2.4438) points, and that in the experimental group was (16.139 ± 2.7043) points. After the end of the ninth week, the subjective assessment of fatigue in the control group was (14.646 ± 2.7453) points, while in the experimental group, it was (11.576 ± 3.2552). Conclusion: The vibrating foam roller massage method can recover athletes from muscle fatigue more efficiently while respecting the limitations imposed by the epidemic situation. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: Uma nova direção de pesquisa para fortalecer o basquetebol, melhorar o nível da função física e aumentar a imunidade dos atletas sob a situação epidêmica da COVID-19 é requisitada. Objetivo: Explorar os métodos específicos de fadiga do basquetebol e recuperação física sob o panorama da COVID-19. Métodos: Foram selecionados aleatoriamente 36 universitários voluntários sem diferenças significativas de altura, peso ou idade para a pesquisa. Divididos em dois grupos, o modo de intervenção do grupo experimental foi a intervenção com rolo de espuma vibratória, enquanto o grupo de controle adotou o método tradicional de caminhada e alongamento. Os dados da avaliação subjetiva da mudança do ácido lático e da fadiga do exercício foram coletados e analisados. Resultados: Em uma hora após o exercício, a taxa e a diminuição do ácido láctico no grupo experimental foram estatisticamente superiores. Antes do início do experimento, a avaliação subjetiva da fadiga no grupo controle foi de (16.031 ± 2.4438) pontos, e a do grupo experimental foi de (16.139 ± 2.7043) pontos. Após o final da nona semana, a avaliação subjetiva da fadiga no grupo controle foi de (14.646 ± 2.7453) pontos, enquanto no experimental foi de (11.576 ± 3.2552) pontos. Conclusão: O método de massagem por rolo de espuma vibratória pode recuperar os atletas da fadiga muscular de forma mais eficiente, respeitando as limitações impostas pela situação epidêmica. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: Se solicita una nueva dirección de investigación para fortalecer el baloncesto, mejorar el nivel de la función física y aumentar la inmunidad de los atletas bajo la situación epidémica de COVID-19. Objetivo: Explorar los métodos específicos de fatiga y recuperación física en baloncesto bajo la perspectiva de COVID-19. Métodos: Para la investigación se seleccionaron aleatoriamente 36 estudiantes universitarios voluntarios sin diferencias significativas de estatura, peso o edad. Divididos en dos grupos, el modo de intervención del grupo experimental fue la intervención con rodillo de espuma vibratoria, mientras que el grupo de control adoptó el método tradicional de caminar y estirar. Se recogieron y analizaron los datos de la evaluación subjetiva del cambio del ácido láctico y la fatiga del ejercicio. Resultados: Una hora después del ejercicio, la tasa y la disminución de ácido láctico en el grupo experimental fueron estadísticamente superiores. Antes del inicio del experimento, la evaluación subjetiva de la fatiga en el grupo de control fue de (16,031 ± 2,4438) puntos, y la del grupo experimental fue de (16,139 ± 2,7043) puntos. Al final de la novena semana, la evaluación subjetiva de la fatiga en el grupo de control fue de (14,646 ± 2,7453) puntos, mientras que en el grupo experimental fue de (11,576 ± 3,2552) puntos. Conclusión: El método de masaje con rodillo de espuma vibratorio puede recuperar a los deportistas de la fatiga muscular de forma más eficaz, respetando las limitaciones impuestas por la situación epidémica. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Cherry extract on post-exercise muscle damage / Extrato de cereja em danos musculares pós-exercício / El extracto de cereza daños musculares post ejercicio

ABSTRACT Introduction: Cherry extract has a high amount of anthocyanins and flavonoids containing antioxidant effects. Its high antioxidant characteristics have been shown to reduce markers of delayed muscle soreness (DOMS) and exercise-induced muscle damage (EIMD) to improve recovery after exercise. Objective: Verify the effects of the cherry extract on post-exercise muscle damage. Methods: Google scholar, Medline, and Scopus were systematically searched until February 2022. The Cochrane Collaboration tool was applied to determine the risks of bias. Results: The results showed that cherry extract administration did not have a decreasing impact on creatine kinase levels overall: (WMD = 12.85 IU. L-1, 95% CI: −35.94, 61.64; P = 0.606). Considerable heterogeneity was observed among the articles (Cochran's Q-test = 990.80, P = 0.000, I2 = 96.7 %). However, there is a significant reducing effect on pain sensation by the consumption of cherry extract (WMD = −6.105 mm; 95% CI: −11.193 −1.017; p = 0.019). Conclusion: Cherry extract consumption effectively reduced late-onset muscle pain among participants in the overall and subgroup analysis. Thus, the cherry extract may be a complementary alternative in recovery after exercise. Level of evidence II; Therapeutic studies - Manuscript review.

RESUMO Introdução: O extrato de cereja tem uma alta quantidade de antocianinas e flavonóides contendo efeitos antioxidantes. Suas altas características antioxidantes demonstraram reduzir os marcadores de dor muscular retardada (DOMS) e dano muscular induzido pelo exercício (EIMD) para melhorar a recuperação após o exercício. Objetivo: Verificar os efeitos do extrato de cereja nos danos musculares pós-exercício. Métodos: Google scholar, Medline e Scopus foram sistematicamente pesquisados até fevereiro de 2022. A ferramenta de colaboração da Cochrane foi aplicada para determinar os riscos de viés. Resultados: Os resultados mostraram que a administração do extrato de cereja não teve um impacto decrescente nos níveis de creatina quinase em geral: (WMD = 12,85 IU. L-1, 95% CI: −35,94, 61,64; P = 0,606). Uma heterogeneidade considerável foi observada entre os artigos (teste Q da Cochran = 990,80, P = 0,000, I2 = 96,7 %). Porém, há um efeito redutor significativo na sensação de dor pelo consumo de extrato de cereja (WMD = −6,105 mm; 95% CI: −11,193 −1,017; p = 0,019). Conclusão: O consumo de extrato de cereja foi efetivo na redução de dores musculares de início tardio entre os participantes, na análise geral e nos subgrupos. Assim, o extrato de cereja pode ser uma alternativa complementar na recuperação após os exercícios. Nível de evidência II; Estudos terapêuticos - Revisão de manuscritos.

RESUMEN Introducción: El extracto de cereza tiene una gran cantidad de antocianinas y flavonoides con efectos antioxidantes. Se ha demostrado que sus altas características antioxidantes reducen los marcadores de dolor muscular retardado (DOMS) y el daño muscular inducido por el ejercicio (EIMD) para mejorar la recuperación después del ejercicio. Objetivo: Verificar los efectos del extracto de cereza en el daño muscular posterior al ejercicio. Métodos: Se realizaron búsquedas sistemáticas en Google scholar, Medline y Scopus hasta febrero de 2022. Se aplicó la herramienta de colaboración Cochrane para determinar los riesgos de sesgo. Resultados: Los resultados mostraron que la administración de extracto de cereza no tuvo un impacto decreciente en los niveles de creatina quinasa en general: (WMD = 12,85 UI. L-1, IC del 95%: −35,94, 61,64; P = 0,606). Se observó una considerable heterogeneidad entre los artículos (prueba Q de Cochran = 990,80, P = 0,000, I2 = 96,7 %). Sin embargo, el consumo de extracto de cereza tiene un efecto significativo de reducción del dolor (WMD = −6,105 mm; IC del 95%: −11,193 −1,017; p = 0,019). Conclusión: El consumo de extracto de cereza fue eficaz para reducir el dolor muscular de aparición tardía entre los participantes en el análisis global y de subgrupos. Así, el extracto de cereza puede ser una alternativa complementaria en la recuperación después de los ejercicios. Nivel de evidencia II; Estudios terapéuticos - Revisión de manuscritos.

TiO2 nanoparticles cause mitochondrial dysfunction, activate inflammatory responses, and attenuate phagocytosis in macrophages: A proteomic and metabolomic insight.

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in food and cosmetics but the health impact of human exposure remains poorly defined. Emerging evidence suggests that TiO2 NPs may elicit immune responses by acting on macrophages. Our proteomic study showed that treatment of macrophages with TiO2 NPs led to significant re-organization of cell membrane and activation of inflammation. These observations were further corroborated with transmission electron microscopy (TEM) experiments, which demonstrated that TiO2 NPs were trapped inside of multi-vesicular bodies (MVB) through endocytotic pathways. TiO2 NP caused significant mitochondrial dysfunction by increasing levels of mitochondrial reactive oxygen species (ROS), decreasing ATP generation, and decreasing metabolic flux in tricarboxylic acid (TCA) cycle from 13C-labelled glutamine using GC-MS-based metabolic flux analysis. Further lipidomic analysis showed that TiO2 NPs significantly decreased levels of cardiolipins, an important class of mitochondrial phospholipids for maintaining proper function of electron transport chains. Furthermore, TiO2 NP exposure activates inflammatory responses by increasing mRNA levels of TNF-α, iNOS, and COX-2. Consistently, our targeted metabolomic analysis showed significantly increased production of COX-2 metabolites including PGD2, PGE2, and 15d-PGJ2. In addition, TiO2 NP also caused significant attenuation of phagocytotic function of macrophages. In summary, our studies utilizing multiple powerful omic techniques suggest that human exposure of TiO2 NPs may have profound impact on macrophage function through activating inflammatory responses and causing mitochondrial dysfunction without physical presence in mitochondria.

Homocysteine directly interacts and activates the angiotensin II type I receptor to aggravate vascular injury.

Hyperhomocysteinemia (HHcy) is a risk factor for various cardiovascular diseases. However, the mechanism underlying HHcy-aggravated vascular injury remains unclear. Here we show that the aggravation of abdominal aortic aneurysm by HHcy is abolished in mice with genetic deletion of the angiotensin II type 1 (AT1) receptor and in mice treated with an AT1 blocker. We find that homocysteine directly activates AT1 receptor signalling. Homocysteine displaces angiotensin II and limits its binding to AT1 receptor. Bioluminescence resonance energy transfer analysis reveals distinct conformational changes of AT1 receptor upon binding to angiotensin II and homocysteine. Molecular dynamics and site-directed mutagenesis experiments suggest that homocysteine regulates the conformation of the AT1 receptor both orthosterically and allosterically by forming a salt bridge and a disulfide bond with its Arg167 and Cys289 residues, respectively. Together, these findings suggest that strategies aimed at blocking the AT1 receptor may mitigate HHcy-associated aneurysmal vascular injuries.

Mitochondrial control of apoptosis through modulation of cardiolipin oxidation in hepatocellular carcinoma: A novel link between oxidative stress and cancer.

Altered redox status in cancer cells has been linked to lipid peroxidation induced by reactive oxygen species (ROS) and subsequent formation of reactive lipid electrophiles, especially 4-hydroxy-nonenal (4-HNE). Emerging evidence suggests that cancer cells manipulate redox status to acquire anti-apoptotic phenotype but the underlying mechanisms are poorly understood. Cardiolipin (CL), a mitochondria-specific inner membrane phospholipid, is critical for maintaining mitochondrial function. Paradoxically, liver tissues contain tetralinoleoyl cardiolipin (TLCL) as the major CL in mitochondria yet emerging evidence suggests that ROS generated in mitochondria may lead to CL peroxidation and activation of intrinsic apoptosis. It remains unclear how CL oxidation leads to apoptosis and its relevance to the pathogenesis of hepatocellular carcinoma (HCC). We employed a mass spectrometry-based lipidomic approach to profile lipids in human tissues of HCC and found that CL was gradually decreased in tumor comparing to peripheral non-cancerous tissues, accompanied by a concomitant decrease of oxidized CL and its oxidation product, 4-HNE. Incubation of liver cancer cells with TLCL significantly restored apoptotic sensitivity accompanied by an increase of CL and its oxidation products when treated with staurosporine (STS) or Sorafenib (the standard treatment for late stage HCC patients). Our studies uncovered a novel mechanism by which cancer cells adopt to evade apoptosis, highlighting the importance of mitochondrial control of apoptosis through modulation of CL oxidation and subsequent 4-HNE formation in HCC. Thus manipulation of mitochondrial CL oxidation and lipid electrophile formation may have potential therapeutic value for diseases linked to oxidative stress and mitochondrial dysfunctions.

Discovery of Novel Lipid Profiles in PCOS: Do Insulin and Androgen Oppositely Regulate Bioactive Lipid Production?

Context: Polycystic ovary syndrome (PCOS) is a complex syndrome showing clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Polyunsaturated fatty acids (PUFAs) and their derivatives, both tightly linked to PCOS and obesity, play important roles in inflammation and reproduction. Objective: This study aimed to investigate serum lipid profiles in newly diagnosed patients with PCOS using lipidomics and correlate these features with the hyperinsulinemia and hyperandrogenism associated with PCOS and obesity. Design and Setting: Thirty-two newly diagnosed women with PCOS and 34 controls were divided into obese and lean subgroups. A PCOS rat model was used to validate results of the human studies. Main Outcome Measures: Serum lipid profiles, including phospholipids, free fatty acids (FFAs), and bioactive lipids, were analyzed using gas chromatography-mass spectrometry (MS) and liquid chromatography-MS. Results: Elevation in phosphatidylcholine and a concomitant decrease in lysophospholipid were found in obese patients with PCOS vs lean controls. Obese patients with PCOS had decreased PUFA levels and increased levels of long-chain saturated fatty acids vs lean controls. Serum bioactive lipids downstream of arachidonic acid were increased in obese controls, but reduced in both obese and lean patients with PCOS vs their respective controls. Conclusions: Patients with PCOS showed abnormal levels of phosphatidylcholine, FFAs, and PUFA metabolites. Circulating insulin and androgens may have opposing effects on lipid profiles in patients with PCOS, particularly on the bioactive lipid metabolites derived from PUFAs. These clinical observations warrant further studies of the molecular mechanisms and clinical implications of PCOS and obesity.

Nickel exposure and prevalent albuminuria and ß2-microglobulinuria: evidence from a population-based study.

BACKGROUND: High exposure to nickel could induce renal dysfunction in rodents and occupational workers. However, little is known about the effects of non-occupational exposure to nickel on renal health in the general population. We aimed to examine the associations of urinary nickel concentrations with albuminuria and ß2-microglobulinuria in Chinese adults. METHODS: 2115 non-institutionalised Chinese men and women aged 55-76 years from Beijing and Shanghai were included. Urinary nickel concentrations were assessed by inductively coupled plasma mass spectroscopy. Plasma uric acid, urea nitrogen, C reactive protein and urinary albumin, ß2-microglobulin and creatinine were measured. Albuminuria was defined as urinary albumin ≥30 mg/g creatinine, and ß2-microglobulinuria was defined as urinary ß2-microglobulin ≥200 µg/g creatinine. RESULTS: Median concentration of urinary nickel was 3.95 µg/g creatinine (IQR: 2.57-6.71 µg/g creatinine), and prevalence of albuminuria, ß2-microglobulinuria and both albuminuria and ß2-microglobulinuria was 22.1%, 24.5% and 9.7%, respectively. Comparing the highest with the lowest quartile of urinary nickel, the ORs (95% CIs) were 1.99 (1.46 to 2.78) for albuminuria, 1.44 (1.07 to 1.95) for ß2-microglobulinuria, and 2.95 (1.74 to 4.97) for both albuminuria and ß2-microglobulinuria, after adjustment for demographic characteristics, lifestyle behaviours, body mass index, hypertension and diabetes. The association remained significant when further controlling for inflammatory markers or other heavy metals (all p trend <0.05). CONCLUSIONS: This study suggested that urinary nickel levels were positively associated with albuminuria and ß2-microglobulinuria in Chinese men and women, who had relatively low background nickel exposure. More prospective studies are needed to confirm our findings.

Cross talk between histone deacetylase 4 and STAT6 in the transcriptional regulation of arginase 1 during mouse dendritic cell differentiation.

l-Arginine and l-arginine-metabolizing enzymes play important roles in the biology of some types of myeloid cells, including macrophage and myeloid-derived suppressor cells. In this study, we found evidence that arginase 1 (Arg1) is required for the differentiation of mouse dendritic cells (DCs). Expression of Arg1 was robustly induced during monocyte-derived DC differentiation. Ectopic expression of Arg1 significantly promoted monocytic DC differentiation in a granulocyte-macrophage colony-stimulating factor culture system and also facilitated the differentiation of CD8α(+) conventional DCs in the presence of Flt3 ligand. Knockdown of Arg1 reversed these effects. Mechanistic studies showed that the induced expression of Arg1 in differentiating DCs was caused by enhanced recruitment of histone deacetylase 4 (HDAC4) to the Arg1 promoter region, which led to a reduction in the acetylation of both the histone 3 and STAT6 proteins and subsequent transcriptional activation of Arg1. Further investigation identified a novel STAT6 binding site within the Arg1 promoter that mediated its regulation by STAT6 and HDAC4. These observations suggest that the cross talk between HDAC4 and STAT6 is an important regulatory mechanism of Arg1 transcription in DCs. Moreover, overexpression of Arg1 clearly abrogated the ability of HDAC inhibitors to suppress DC differentiation. In conclusion, we show that Arg1 is a novel regulator of myeloid DC differentiation.

Nickel exposure is associated with the prevalence of type 2 diabetes in Chinese adults.

BACKGROUND: Nickel exposure can induce hyperglycaemia in rodents, but little is known about its association with abnormal glucose metabolism in humans. We aimed to investigate the association of nickel exposure with the prevalence of type 2 diabetes in Chinese adults. METHODS: A total of 2115 non-institutionalized men and women aged 55 to 76 years from Beijing and Shanghai were included, and urinary nickel concentration was assessed by inductively coupled plasma mass spectroscopy. The prevalence of type 2 diabetes was compared across urinary nickel quartiles. Fasting plasma glucose, insulin, lipids, C-reactive protein and glycated haemoglobin A1c, as well as urinary albumin and creatinine were measured. RESULTS: The median concentration of urinary nickel was 3.63 mg/l (interquartile range: 2.29­5.89 mg/l), and the prevalence of diabetes was 35.3% (747 cases/2115 persons). Elevated levels of urinary nickel were associated with higher fasting glucose, glycated haemoglobin A1c, insulin and homeostatic model assessment of insulin resistance (all P<0.01). The odds ratios (95% confidence interval) for diabetes across the increasing urinary nickel quartiles were 1.27 (0.97­1.67), 1.78 (1.36­2.32) and 1.68 (1.29­2.20), respectively (referencing to 1.00), after multivariate adjustment including lifestyle factors, body mass index and family history of diabetes (P for trend <0.001). The association remained unchanged after further controlling for urinary creatinine and C-reactive protein (P for trend <0.001). CONCLUSIONS: Increased urinary nickel concentration is associated with elevated prevalence of type 2 diabetes in humans.