Alpha-tocopherol induces expression of connective tissue growth factor and antagonizes tumor necrosis factor-alpha-mediated downregulation in human smooth muscle cells

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

Vitamin E: Where Are We Now in Vascular Diseases?

Vitamin E is one of the most popular fat-soluble vitamins in pathological research and has been under scrutiny since the 1980s as a vital dietary component of food. The antioxidant effect of vitamin E has been widely studied due to its benefits in the prevention of various cardiovascular diseases. In recent years, alternative effects of vitamin E, in terms of anti-inflammatory pathways and gene regulation, have also been of interest to researchers. This review examines the role of dietary vitamin E (α-tocopherol) as an antioxidant and bioactive molecule in promoting vascular health. While the antioxidant effect of vitamin E is well established, knowledge about its capacity as a promising regulatory molecule in the control of the vascular system is limited. The aim of this review is to discuss some of these mechanisms and summarize their role in the prevention of cardiovascular diseases (CVD). Here, we also briefly discuss foods rich in vitamin E, and deliberate some potential toxicological effects of excessive supplemental vitamin E in the body.

Strategies to Combat Heat Stress in Broiler Chickens: Unveiling the Roles of Selenium, Vitamin E and Vitamin C

Heat stress compromises efficient poultry production by impairing growth performance and increasing mortality. Mechanisms to dissipate excess heat divert energy from efficient production. This includes increased energy expenditure for respiration, oxidative stress and micronutrient absorption. The fortification of diets with particular feed additives has been known as one of the most important approaches to minimize the negative impacts of heat stress on broiler production. In this context, the promising functional feed additives appeared to be selenium and vitamins E and C. The fortification of broiler diets with these feed additives has been proven to enhance the function of vital organs, immune system response and growth performance of broilers under heat stress. The current review highlights recent successful experiences in the alleviation of heat stress symptoms in broilers using the above-mentioned additives. Selenium and vitamins E and C enhanced production performance in broiler chickens challenged with acute heat stress. The combination of these additives, by employing multiple mechanisms and through synergistic effects, improves heat stress symptoms more efficiently than their individual forms. Emerging literature reveals that selenium and vitamins E and C are involved in close interactions to protect proteins and lipids from oxidative damage and boost immune system function.

Eyeing the Extracellular Matrix in Vascular Development and Microvascular Diseases and Bridging the Divide between Vascular Mechanics and Function

The extracellular matrix (ECM) is critical in all aspects of vascular development and health: supporting cell anchorage, providing structure, organization and mechanical stability, and serving as a sink for growth factors and sustained survival signals. Abnormal changes in ECM protein expression, organization, and/or properties, and the ensuing changes in vascular compliance affect vasodilator responses, microvascular pressure transmission, and collateral perfusion. The changes in microvascular compliance are independent factors initiating, driving, and/or exacerbating a plethora of microvascular diseases of the eye including diabetic retinopathy (DR) and vitreoretinopathy, retinopathy of prematurity (ROP), wet age-related macular degeneration (AMD), and neovascular glaucoma. Congruently, one of the major challenges with most vascular regenerative therapies utilizing localized growth factor, endothelial progenitor, or genetically engineered cell delivery, is the regeneration of blood vessels with physiological compliance properties. Interestingly, vascular cells sense physical forces, including the stiffness of their ECM, through mechanosensitive integrins, their associated proteins and the actomyosin cytoskeleton, which generates biochemical signals that culminate in a rapid expression of matricellular proteins such as cellular communication network 1 (CCN1) and CCN2 (aka connective tissue growth factor or CTGF). Loss or gain of function of these proteins alters genetic programs of cell growth, ECM biosynthesis, and intercellular signaling, that culminate in changes in cell behavior, polarization, and barrier function. In particular, the function of the matricellular protein CCN2/CTGF is critical during retinal vessel development and regeneration wherein new blood vessels form and invest a preformed avascular neural retina following putative gradients of matrix stiffness. These observations underscore the need for further in-depth characterization of the ECM-derived cues that dictate structural and functional properties of the microvasculature, along with the development of new therapeutic strategies addressing the ECM-dependent regulation of pathophysiological stiffening of blood vessels in ischemic retinopathies.

Antioxidants and Atherosclerosis: Mechanistic Aspects

Atherosclerosis is a chronic inflammatory disease which is a major cause of coronary heart disease and stroke in humans. It is characterized by intimal plaques and cholesterol accumulation in arterial walls. The side effects of currently prescribed synthetic drugs and their high cost in the treatment of atherosclerosis has prompted the use of alternative herbal medicines, dietary supplements, and antioxidants associated with fewer adverse effects for the treatment of atherosclerosis. This article aims to present the activity mechanisms of antioxidants on atherosclerosis along with a review of the most prevalent medicinal plants employed against this multifactorial disease. The wide-ranging information in this review article was obtained from scientific databases including PubMed, Web of Science, Scopus, Science Direct and Google Scholar. Natural and synthetic antioxidants have a crucial role in the prevention and treatment of atherosclerosis through different mechanisms. These include: The inhibition of low density lipoprotein (LDL) oxidation, the reduction of reactive oxygen species (ROS) generation, the inhibition of cytokine secretion, the prevention of atherosclerotic plaque formation and platelet aggregation, the preclusion of mononuclear cell infiltration, the improvement of endothelial dysfunction and vasodilation, the augmentation of nitric oxide (NO) bioavailability, the modulation of the expression of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, and the suppression of foam cell formation.

Avian Stress-Related Transcriptome and Selenotranscriptome: Role during Exposure to Heavy Metals and Heat Stress

Selenium, through incorporation into selenoproteins, is one of the key elements of the antioxidant system. Over the past few years there has been increased interest in exploring those molecular mechanisms in chicken, responsible for the development of this protection system. In more detail, Cd/Pb poisoning and heat stress increase oxidation, mRNA levels of inflammatory proteins, and apoptotic proteins. Selenium seems to enhance the antioxidant status and alleviates these effects via upregulation of antioxidant proteins and other molecular effects. In this review, we analyze avian transcriptome key elements with particular emphasis on interactions with heavy metals and on relation to heat stress.

Vitamin E: Regulatory Role on Signal Transduction

Vitamin E modulates signal transduction pathways by several molecular mechanisms. As a hydrophobic molecule located mainly in membranes it contributes together with other lipids to the physical and structural characteristics such as membrane stability, curvature, fluidity, and the organization into microdomains (lipid rafts). By acting as the main lipid-soluble antioxidant, it protects other lipids such as mono- and poly-unsaturated fatty acids (MUFA and PUFA, respectively) against chemical reactions with reactive oxygen and nitrogen species (ROS and RNS, respectively) and prevents membrane destabilization and cellular dysfunction. In cells, vitamin E affects signaling in redox-dependent and redox-independent molecular mechanisms by influencing the activity of enzymes and receptors involved in modulating specific signal transduction and gene expression pathways. By protecting and preventing depletion of MUFA and PUFA it indirectly enables regulatory effects that are mediated by the numerous lipid mediators derived from these lipids. In recent years, some vitamin E metabolites have been observed to affect signal transduction and gene expression and their relevance for the regulatory function of vitamin E is beginning to be elucidated. In particular, the modulation of the CD36/FAT scavenger receptor/fatty acids transporter by vitamin E may influence many cellular signaling pathways relevant for lipid homeostasis, inflammation, survival/apoptosis, angiogenesis, tumorigenesis, neurodegeneration, and senescence. Thus, vitamin E has an important role in modulating signal transduction and gene expression pathways relevant for its uptake, distribution, metabolism, and molecular action that when impaired affect physiological and patho-physiological cellular functions relevant for the prevention of a number of diseases. © 2018 IUBMB Life, 71(4):456-478, 2019.

Effect of diets supplemented with linseed alone or combined with vitamin E and selenium or with plant extracts, on Longissimus thoracis transcriptome in growing-finishing Italian Large White pigs

Background

Supplementing farm animals diet with functional ingredients may improve the nutritional quality of meat products. Diet composition has been also demonstrated to influence the gene expression with effect on biological processes and pathways. However, the knowledge on the effect of nutrients at the molecular level is scant. In particular, studies on the effects of antioxidants and polyphenols dietary supplementation have been investigated mainly in rodents, and only scarcely in farm animals so far. RNA-Seq with next-generation sequencing is increasingly the method of choice for studying changes in the transcriptome and it has been recently employed also in pig nutrigenomics studies to identify diet-induced changes in gene expression. The present study aimed to investigate the effect of diets enriched with functional ingredients (linseed, vitamin E and plant extracts) on the transcriptome of pig Longissimus thoracis to elucidate the role of these compounds in influencing genes involved in muscle physiology and metabolism compared to a standard diet.

Results

Eight hundred ninety-three significant differentially expressed genes (DEGs) (FDR adjusted P-value ≤ 0.05) were detected by RNA-Seq analysis in the three diet comparisons (D2-D1, D3-D1, D4-D1). The functional analysis of DEGs showed that the diet enriched with n-3 PUFA from linseed (D2) mostly downregulated genes in pathways and biological processes (BPs) related to muscle development, contraction, and glycogen metabolism compared to the standard diet. The diet supplemented with linseed and vitamin E/Selenium (D3) showed to mostly downregulate genes linked to oxidative phosphorylation. Only few genes involved in extracellular matrix (ECM) organization were upregulated by the D3. Finally, the comparison D4-D1 showed that the diet supplemented with linseed and plant extracts (D4) upregulated the majority of genes compared to D1 that were involved in a complex network of pathways and BPs all connected by hub genes. In particular, IGF2 was a hub gene connecting protein metabolism, ECM organization, immune system and lipid biosynthesis pathways.

Conclusion

The supplementation of pig diet with n-3 PUFA from linseed, antioxidants and plant-derived polyphenols can influence the expression of a relevant number of genes in Longissimus thoracis muscle that are involved in a variety of biochemical pathways linked to muscle function and metabolism.

Betaine and Antioxidants Improve Growth Performance, Breast Muscle Development and Ameliorate Thermoregulatory Responses to Cyclic Heat Exposure in Broiler Chickens

Heat stress (HS) is an environmental stressor challenging poultry production and requires a strategy to cope with it. A total of 288-day-old male broiler chicks were fed with one of the following diets: basal diet, basal with betaine (BET), or with selenium and vitamin E (AOX), or with a combination of BET and AOX, under thermoneutral and cyclic HS. Results showed that HS reduced average daily feed intake (ADFI) (p = 0.01) and average daily gain (ADG) (p < 0.001), and impaired feed conversion ratio (FCR) (p = 0.03) during rearing period (0⁻42 day). BET increased ADG (p = 0.001) and decreased FCR (p = 0.02), whereas AOX had no effects. Breast muscle weight was decreased by HS (p < 0.001) and increased by BET (p < 0.001). Rectal temperature was increased by HS (p < 0.001) and improved by BET overall. Respiration rate was increased by HS (p < 0.001), but BET decreased it during HS (p = 0.04). Jejunum transepithelial resistance was reduced by HS and had no effect on permeability whereas BET increased jejunum permeability (p = 0.013). Overall, the reductions in ADG of broiler chickens during HS were ameliorated by supplementation with BET, with much of the increase in ADG being breast muscle.

Alpha-Tocopherol Serum Levels Are Increased in Caucasian Women with Uterine Fibroids: A Pilot Study

Uterine fibroids (UFs) are benign tumors of the reproductive tract, arising from smooth muscle cells of the uterus. Steroid hormones, estrogen, and progesterone are considered to be the most important links in the pathophysiology of UFs. Alpha-tocopherol (AT) is the most active form of vitamin E. What is important as far as UFs are concerned is that ATs contain structural determinants, which makes them possible ligands for estrogen receptors (ERs). We present a retrospective cohort study performed in a university teaching hospital. We included a total of 162 patients divided into 2 groups: with UFs and controls. The effects of age, body mass index (BMI), positive medical history, parity, and AT serum concentrations on the risk for the development of UFs were investigated. Mean AT serum concentrations were 11.66 ± 4.97 μg/ml and 7.83 ± 3.13 μg/ml (medians 10.56 μg/ml and 7.42 μg/ml) in patients with UFs confirmed on ultrasound and controls, respectively. The presented difference was statistically significant. Higher BMI, positive family history, and low parity were found to be major risk factors for UFs. In our study, we confirmed that elevated serum AT concentration might be an important risk factor for UFs in Caucasian women. Further research in this area is necessary.

Naturally Occurring Compounds: New Potential Weapons against Oxidative Stress in Chronic Kidney Disease

Oxidative stress is a well-described imbalance between the production of reactive oxygen species (ROS) and the antioxidant defense system of cells and tissues. The overproduction of free radicals damages all components of the cell (proteins, lipids, nucleic acids) and modifies their physiological functions. As widely described, this condition is a biochemical hallmark of chronic kidney disease (CKD) and may dramatically influence the progression of renal impairment and the onset/development of major systemic comorbidities including cardiovascular diseases. This state is exacerbated by exposure of the body to uremic toxins and dialysis, a treatment that, although necessary to ensure patients' survival, exposes cells to non-physiological contact with extracorporeal circuits and membranes with consequent mitochondrial and anti-redox cellular system alterations. Therefore, it is undeniable that counteracting oxidative stress machinery is a major pharmacological target in medicine/nephrology. As a consequence, in recent years several new naturally occurring compounds, administered alone or integrated with classical therapies and an appropriate lifestyle, have been proposed as therapeutic tools for CKD patients. In this paper, we reviewed the recent literature regarding the "pioneering" in vivo testing of these agents and their inclusion in small clinical trials performed in patients affected by CKD.

Habitual dietary intake of β-carotene, vitamin C, folate, or vitamin E may interact with single nucleotide polymorphisms on brachial-ankle pulse wave velocity in healthy adults

PURPOSE

The interaction between genetics and diet may explain the present disagreement in the protective role of vitamin intake on cardiovascular disease. We cross-sectionally assessed the interaction of habitual dietary intake of β-carotene, vitamin C, folate, and vitamin E with single nucleotide polymorphisms (SNPs) on brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness.

METHODS

Dietary intakes of β-carotene, vitamin C, folate, and vitamin E were quantified by a food frequency questionnaire in 3198 healthy men and women (≥ 40 years) from the Korea Multi-Rural communities Cohort study. baPWV was measured, and 19 SNPs were genotyped. The associations and interactions between dietary vitamin intake, SNP genotype, and baPWV were assessed using general linear models.

RESULTS

In both men and women, dietary intake of β-carotene, vitamin C, folate, or vitamin E and baPWV were not directly associated. Vitamin C, folate, and vitamin E intake had an interaction with rs4961 (ADD1) genotype on baPWV in men. rs4961 also interacted with folate intake on baPWV in women. In women, rs10817542 (ZNF618) and rs719856 (CD2AP) had an interaction with β-carotene and folate intake and rs5443 (GNB3) had an interaction with vitamin E intake on baPWV. In general, minor allele homozygotes with low vitamin intake had higher baPWV than other subgroups. Results were similar when supplement users were excluded.

CONCLUSIONS

Higher intake of dietary vitamin C, folate, and vitamin E may be related to high baPWV in healthy Korean men who are minor allele homozygotes of rs4961. In healthy Korean women, dietary folate, β-carotene, and vitamin E intake may affect baPWV differently according to rs4961, rs10817542, rs719856, or rs5443 genotype. Greater dietary intake of these nutrients may protect those that are genetically vulnerable to stiffening of the arteries.

Supplementation with vitamin E alone is associated with reduced myocardial infarction: a meta-analysis

BACKGROUND AND AIMS

Previous meta-analyses of interventional trials with vitamin E provided negative results but it remains unclear if this vitamin has some influence on cardiovascular events when supplemented alone. The aim of this study was to compare the effect of vitamin E alone or in combination with other antioxidants on myocardial infarction.

METHODS AND RESULTS

Pubmed, ISI Web of Science, SCOPUS and Cochrane database were searched without language restrictions. We investigated randomized clinical trials studying the effect of vitamin E supplementation on myocardial infarction. Sixteen randomized controlled trials of vitamin E treatment were analyzed in this meta-analysis. The dose range for vitamin E was 33-800IU. Follow-up ranged from 0.5 to 9.4 years. Compared to controls, vitamin E given alone significantly decreased myocardial infarction (3.0% vs 3.4%) (random effects R.R.: 0.82; 95% C.I., 0.70-0.96; p = 0.01). This effect was driven by reduction of fatal myocardial infarction (random effects R.R.: 0.84; 95% C.I., 0.73-0.96; p = 0.01).

CONCLUSIONS

When supplemented alone, vitamin E reduces myocardial infarction in interventional trials while it appears ineffective when associated with other antioxidants.

Cellular and molecular actions of CCN2/CTGF and its role under physiological and pathological conditions

CCN family protein 2 (CCN2), also widely known as connective tissue growth factor (CTGF), is one of the founding members of the CCN family of matricellular proteins. Extensive investigation on CCN2 over decades has revealed the novel molecular action and functional properties of this unique signalling modulator. By its interaction with multiple molecular counterparts, CCN2 yields highly diverse and context-dependent biological outcomes in a variety of microenvironments. Nowadays, CCN2 is recognized to conduct the harmonized development of relevant tissues, such as cartilage and bone, in the skeletal system, by manipulating extracellular signalling molecules involved therein by acting as a hub through a web. However, on the other hand, CCN2 occasionally plays profound roles in major human biological disorders, including fibrosis and malignancies in major organs and tissues, by modulating the actions of key molecules involved in these clinical entities. In this review, the physiological and pathological roles of this unique protein are comprehensively summarized from a molecular network-based viewpoint of CCN2 functionalities.

Anti-mutagenicity Effects of Vitamin E on Oncology and Non-oncology Hospital Nurses by Ames Assay

INTRODUCTION

The aim of this study is to determine the anti-mutagenic effects of Vitamin E among nurses of oncology and non-oncology hospitals exposed to chemotherapy drugs. Several studies have demonstrated that nurses occupationally exposes to cytostatic drugs.

MATERIAL AND METHODS

A total of 138 female nurses from oncology and non-oncology hospitals participated in the study. All urine samples of nurses before and after Vitamin E consumption (200 mg/day) were evaluated by Ames Salmonella typhimorium mutagenicity test using histidine negative of tester strain TA100 with and without S-9mix. In all steps the collected urine samples extracts were prepared using amberlit XAD-2 resins and examined for mutagenicity activity. The data of Ames assay were analyzed with Anova one way and t-test statistical.

RESULTS

In the present study 25% of oncology nursing staff excrete carcinogenic compounds in their urine and oral consumption of Vitamin E for two weeks showed significant anti-mutagenic effects.

DISCUSSION

It was appeared that the urinary mutagenic activity will decrease by receiving Vitamin E. However, after Vitamin E consumption there was significantly depletion of urinary mutagenic activity in urine extracts among the exposed nursing personnel.

CONCLUSION

We conclude that mild effects of Vitamin E against poor safety and significant adverse events among nurses handling cytotoxic drugs. There is, therefore, a need to improve the safety of the work environment, make available protective equipment, develop standard practice guidelines for oncology nurses and higher therapeutic doses of Vitamin E may be a promising compound for reducing mutagenic effects of anti-neoplastic drugs among oncology hospital nurses.

Regulatory metabolites of vitamin E and their putative relevance for atherogenesis

Vitamin E is likely the most important antioxidant in the human diet and α-tocopherol is the most active isomer. α-Tocopherol exhibits anti-oxidative capacity in vitro, and inhibits oxidation of LDL. Beside this, α-tocopherol shows anti-inflammatory activity and modulates expression of proteins involved in uptake, transport and degradation of tocopherols, as well as the uptake, storage and export of lipids such as cholesterol. Despite promising anti-atherogenic features in vitro, vitamin E failed to be atheroprotective in clinical trials in humans. Recent studies highlight the importance of long-chain metabolites of α-tocopherol, which are formed as catabolic intermediate products in the liver and occur in human plasma. These metabolites modulate inflammatory processes and macrophage foam cell formation via mechanisms different than that of their metabolic precursor α-tocopherol and at lower concentrations. Here we summarize the controversial role of vitamin E as a preventive agent against atherosclerosis and point the attention to recent findings that highlight a role of these long-chain metabolites of vitamin E as a proposed new class of regulatory metabolites. We speculate that the metabolites contribute to physiological as well as pathophysiological processes.

Effect of vitamin e on uroepithelial cells and changes of urinary sediments in oncology hospital nursing personnel

INTRODUCTION

Vitamin E is an important natural antioxidant, and its most common and biologically active form is α-tocopherol. The antiproliferative effects of alpha-tocopherol have been previously demonstrated. In this study we investigated the effects of vitamin E on urinary epithelial cells and urinary sediments of nursing from oncology hospital.

MATERIAL AND METHODS

Sixty-two female nursing personnel from oncology hospital participated in the study. They received orally 200mg of vitamin E per day for two weeks. Also prior to vitamin E and after vitamin E administration, the uroepithelial cells counts and other components of urinary sediments were carried out.

RESULTS

There were significant differences in the epithelial cells count and treatment with vitamin E causing significantly more number of epithelial cells and urinary sediments to be excreted in the urine.

DISCUSSION

Vitamin E significantly plays an important role on the excretion of uroepithelial cells and urinary sediments.

CONCLUSION

In conclusion we propose that use of vitamin E at nontoxic levels would significantly enhance its antioxidative properties, especially among individuals subjected to prophylaxis of occupational hazards.

Association between the plasma proteome and plasma α-tocopherol concentrations in humans

Vitamin E is a lipophilic antioxidant that has been inversely associated with certain chronic diseases; however, the biological processes regulated by this vitamin have not been fully elucidated. The objective of the present study was to examine the association between the most biologically active and abundant form of vitamin E in the circulation, α-tocopherol, and the plasma proteome. Subjects were from the Toronto Nutrigenomics and Health Study and included men and women (n=1,022) who completed a general health and lifestyle questionnaire and 196-item food frequency questionnaire, and provided a fasting blood sample. Plasma α-tocopherol concentrations were measured by high-performance liquid chromatography and 54 plasma proteins were assayed by a mass spectrometry-based multiple reaction monitoring method. Analysis of covariance was used to compare mean concentrations of plasma proteins across tertiles of α-tocopherol. Plasma concentrations of apolipoprotein C-III, fibrinogen alpha, beta, and gamma chains, fibronectin and fibrinopeptide A were significantly and positively associated with plasma α-tocopherol, while intermediate levels of α-tocopherol were significantly associated with higher levels of alpha-1B-glycoprotein (all P<.0009). These findings show that circulating levels of α-tocopherol are significantly associated with specific plasma proteins and suggest novel physiological effects of vitamin E.

Vitamin E reduces TGF-beta2-induced changes in human trabecular meshwork cells

AIM

To determine the effects of vitamin E on transforming growth factor-beta2 (TGF-β2)-induced cellular changes in cultured human trabecular meshwork (TM) cells.

MATERIALS AND METHODS

Human TM cells were pre-treated with different concentrations of vitamin E. Afterwards, cells were exposed to 1.0 ng/ml TGF-β2 for 24 h. Expressions of the heat shock protein αB-crystallin, the extracellular matrix (ECM) component fibronectin and the ECM-degrading enzyme matrix metalloproteinase-2 (MMP-2) were examined by real-time polymerase chain reaction (PCR) analyses. The cytoskeleton was investigated by phalloidin staining.

RESULTS

TGF-β2 increased the expressions of αB-crystallin and fibronectin and reduced the levels of MMP-2. TGF-β2 induced the formation of actin stress fibers and cross-linked actin networks. Pre-treatment with different concentrations of vitamin E reversed the TGF-β2-induced cellular changes in cultured human TM cells.

CONCLUSIONS

TGF-β2-mediated changes in human TM cells could be reduced by pre-treatment with vitamin E. Therefore, it may be speculated that increasing the antioxidative capacity may help to lower the incidence of characteristic glaucomatous changes in the TM.

Antioxidants reduce TGF-beta2-induced gene expressions in human optic nerve head astrocytes

PURPOSE

The goal of the present study was to investigate whether the antioxidants vitamin E, vitamin C and vitamin B1 can reduce the transforming growth factor-beta2 (TGF-β2)-induced gene expressions in cultured human optic nerve head (ONH) astrocytes.

METHODS

Cultured human ONH astrocytes were pretreated with different concentrations of vitamin E, vitamin C and vitamin B1 and then exposed to 1.0 ng/ml TGF-β2 for 24 hr. Expression of the heat shock proteins Hsp27 and αB-crystallin, the extracellular matrix (ECM) component fibronectin and the ECM-modulating protein connective tissue growth factor (CTGF) was detected by immunohistochemistry or real-time PCR analysis.

RESULTS

TGF-β2 increased the expression of Hsp27, αB-crystallin, fibronectin and CTGF in human ONH astrocytes. Pretreatment with different concentrations of vitamin E, vitamin C and vitamin B1 reduced the TGF-β2-stimulated gene expressions.

CONCLUSION

In cultured human ONH astrocytes, the TGF-β2-stimulated gene expressions could be reduced by pretreatment with vitamin E, vitamin C and vitamin B1. Therefore, the use of antioxidants in glaucomatous optic neuropathy might be a promising approach to prevent TGF-β2-induced cellular changes in ONH astrocytes.

IFN-γ and TNF-α synergize to inhibit CTGF expression in human lung endothelial cells

Connective tissue growth factor (CTGF/CCN2) is an angiogenetic and profibrotic factor, acting downstream of TGF-β, involved in both airway- and vascular remodeling. While the T-helper 1 (Th1) cytokine interferon-gamma (IFN-γ) is well characterized as immune-modulatory and anti-fibrotic cytokine, the role of IFN-γ in lung endothelial cells (LEC) is less defined. Tumour necrosis factor alpha (TNF-α) is another mediator that drives vascular remodeling in inflammation by influencing CTGF expression. In the present study we investigated the influence of IFN-γ and TNF-α on CTGF expression in human LEC (HPMEC-ST1.6R) and the effect of CTGF knock down on human LEC. IFN-γ and TNF-α down-regulated CTGF in human LEC at the promoter-, transcriptional- and translational-level in a dose- and time-dependent manner. The inhibitory effect of IFN-γ on CTGF-expression could be almost completely compensated by the Jak inhibitor AG-490, showing the involvement of the Jak-Stat signaling pathway. Besides the inhibitory effect of IFN-γ and TNF-α alone on CTGF expression and LEC proliferation, these cytokines had an additive inhibitory effect on proliferation as well as on CTGF expression when administered together. To study the functional role of CTGF in LEC, endogenous CTGF expression was down-regulated by a lentiviral system. CTGF silencing in LEC by transduction of CTGF shRNA reduced cell proliferation, but did not influence the anti-proliferative effect of IFN-γ and TNF-α. In conclusion, our data demonstrated that CTGF was negatively regulated by IFN-γ in LEC in a Jak/Stat signaling pathway-dependent manner. In addition, an additive effect of IFN-γ and TNF-α on inhibition of CTGF expression and cell proliferation could be found. The inverse correlation between IFN-γ and CTGF expression in LEC could mean that screwing the Th2 response to a Th1 response with an additional IFN-γ production might be beneficial to avoid airway remodeling in asthma.

Therapeutic management of intestinal fibrosis induced by radiation therapy: from molecular profiling to new intervention strategies et vice et versa

Chronic toxicities of locoregional and systemic oncological treatments commonly develop in long-term cancer survivors. Amongst these toxicities, post-radiotherapeutic complications alter patient's quality of life. Reduction of exposure of normal tissues can be achieved by optimization of radiotherapy. Furthermore, understanding of the fibrogenic mechanisms has provided targets to prevent, mitigate, and reverse late radiation-induced damages. This mini-review shows how (i) global molecular studies using gene profiling can provide tools to develop new intervention strategies and (ii) how successful clinical trials, conducted in particular with combined pentoxifylline-vitamin E, can take benefice of biological and molecular evidences to improve our understanding of fibrogenic mechanisms, enhance the robustness of proposed treatments, and lead ultimately to better treatments for patient's benefice.

Serum Levels of Vitamin E Are Associated With Early Recurrence of Atrial Fibrillation After Electric Cardioversion

Background—

Oxidative stress is suggested to play a role in favoring the occurrence of atrial fibrillation (AF). We analyzed whether vitamin E, a known antioxidant, or markers of oxidative stress are associated with AF recurrence in patients undergoing electric cardioversion.

Methods and Results—

A total of 144 patients (83 men; mean age, 71.1±5.4 years) underwent successful biphasic electric cardioversion of nonvalvular persistent AF. At baseline, urinary 8-isoprostaglandin F2α and serum soluble NOX2-derived peptide (sNOX2-dp), high-sensitivity C-reactive protein (hs-CRP), and vitamin E levels were measured in each patient. All patients underwent 3 months of clinical follow-up, including an office visit with ECG every week or in cases of symptom recurrence. During the follow-up, 94 patients maintained sinus rhythm, whereas 50 experienced AF recurrence. In unadjusted analysis, left atrial diameter and levels of urinary isoprostanes and serum sNOX2-dp and hs-CRP were significantly higher and serum vitamin E lower in patients with AF recurrence. In multivariable Cox analysis, serum vitamin E (hazard ratio, 0.734; 95% CI, 0.605–0.891; P <0.001) and, to a lesser extent, hs-CRP ( P =0.047) remained significantly associated with AF recurrence. Urinary isoprostanes and serum sNOX2-dp levels were inversely correlated with serum vitamin E level ( r =−0.626, P <0.001, and r =−0.460, P <0.001, respectively).

Conclusions—

The study shows that low serum vitamin E levels are associated with AF recurrence in patients who underwent cardioversion. Because vitamin E inversely correlated with oxidative stress, the findings reinforce the hypothesis of an interplay between oxidative stress and AF.

Vitamin-regulated cytokines and growth factors in the CNS and elsewhere

There is a growing awareness that natural vitamins (with the only exception of pantothenic acid) positively or negatively modulate the synthesis of some cytokines and growth factors in the CNS, and various mammalian cells and organs. As natural vitamins are micronutrients in the human diet, studying their effects can be considered a part of nutritional genomics or nutrigenomics. A given vitamin selectively modifies the synthesis of only a few cytokines and/or growth factors, although the same cytokine and/or growth factor may be regulated by more than one vitamin. These effects seem to be independent of the effects of vitamins as coenzymes and/or reducing agents, and seem to occur mainly at genomic and/or epigenetic level, and/or by modulating NF-kappaB activity. Although most of the studies reviewed here have been based on cultured cell lines, but their findings have been confirmed by some key in vivo studies. The CNS seems to be particularly involved and is severely affected by most avitaminoses, especially in the case of vitamin B(12). However, the vitamin-induced changes in cytokine and growth factor synthesis may initiate a cascade of events that can affect the function, differentiation, and morphology of the cells and/or structures not only in the CNS, but also elsewhere because most natural vitamins, cytokines, and growth factors cross the blood-brain barrier. As cytokines are essential to CNS-immune and CNS-hormone system communications, natural vitamins also interact with these circuits. Further studies of such vitamin-mediated effects could lead to vitamins being used for the treatment of diseases which, although not true avitaminoses, involve an imbalance in cytokine and/or growth factor synthesis.

Transcriptional coactivator with PDZ-binding motif is essential for normal alveolarization in mice

RATIONALE

Transcriptional coactivator with PDZ-binding motif (TAZ) is assumed to act as a coactivator of several transcription factors including smad2/3. In the lung, surfactant protein C (Sftpc) is known to be a downstream target of thyroid transcription factor-1 (TTF-1)-TAZ transcriptional coactivation.

OBJECTIVES

The lung phenotype of Taz-deficient mice was explored.

METHODS

Taz-deficient mice were analyzed pathologically and physiologically. Next, we performed microarray analysis to determine the genes closely related to abnormal lung development. Finally, Taz-heterozygous mice were injected with bleomycin.

MEASUREMENTS AND MAIN RESULTS

Taz-deficient homozygotes showed abnormal alveolarization during lung development, which caused in adult mice airspace enlargement mimicking emphysema. There was no significant difference in the expression of Sftpc between wild-type and Taz-deficient lungs. Instead, microarray analysis identified some candidate downstream genes related to the pathogenesis, including the connective tissue growth factor (Ctgf) gene, which is required for normal lung development. In vitro studies showed that TAZ up-regulated Ctgf expression not only by reinforcing transforming growth factor-beta/smad signals, but also by interfering in the more proximal Ctgf promoter region (from bp -123 to -76), defined as the TAZ response element. Furthermore, Taz-heterozygous mice were resistant to bleomycin-induced lung fibrosis.

CONCLUSIONS

The results indicate the importance of TAZ in lung alveolarization and its involvement in the pathogenesis of lung fibrosis.

Connective tissue growth factor and cardiac fibrosis

Cardiac fibrosis is a major pathogenic factor in a variety of cardiovascular diseases and refers to an excessive deposition of extracellular matrix components in the heart, which leads to cardiac dysfunction and eventually overt heart failure. Evidence is accumulating for a crucial role of connective tissue growth factor (CTGF) in fibrotic processes in several tissues including the heart. CTGF orchestrates the actions of important local factors evoking cardiac fibrosis. The central role of CTGF as a matricellular protein modulating the fibrotic process in cardiac remodelling makes it a possible biomarker for cardiac fibrosis and a potential candidate for therapeutic intervention to mitigate fibrosis in the heart.

Vitamin E: An overview of major research directions

During the last 90 years since the discovery of vitamin E, research has focused on different properties of this molecule, the focus often depending on the specific techniques and scientific knowledge present at each time. Originally discovered as a dietary factor essential for reproduction in rats, vitamin E has revealed in the meantime many more important molecular properties, such as the scavenging of reactive oxygen and nitrogen species with consequent prevention of oxidative damage associated with many diseases, or the modulation of signal transduction and gene expression in antioxidant and non-antioxidant manners. Research over the last 30 years has also resolved the biosynthesis and occurrence of vitamin E in plants, the proteins involved in the cellular uptake, tissue distribution and metabolism, and defined a congenital recessive neurological disease, ataxia with vitamin E deficiency (AVED), characterized by impaired enrichment of alpha-tocopherol in plasma as a result of mutations in the liver alpha-tocopherol transfer gene. This review is giving a brief introduction about vitamin E by following the major research directions since its discovery with a historical perspective.

Cellular, molecular and clinical aspects of vitamin E on atherosclerosis prevention

Randomised clinical trials and epidemiologic studies addressing the preventive effects of vitamin E supplementation against cardiovascular disease reported both positive and negative effects, and recent meta-analyses of the clinical studies were rather disappointing. In contrast to that, many animal studies clearly show a preventive action of vitamin E in several experimental settings, which can be explained by the molecular and cellular effects of vitamin E observed in cell cultures. This review is focusing on the molecular effects of vitamin E on the cells playing a role during atherosclerosis, in particular on the endothelial cells, vascular smooth muscle cells, monocytes/macrophages, T cells, and mast cells. Vitamin E may act by normalizing aberrant signal transduction and gene expression in antioxidant and non-antioxidant manners; in particular, over-expression of scavenger receptors and consequent foam cell formation can be prevented by vitamin E. In addition to that, the cellular effects of alpha-tocopheryl phosphate and of EPC-K1, a composite molecule between alpha-tocopheryl phosphate and l-ascorbic acid, are summarized.

Molecular mechanism of alpha-tocopherol action

The inability of other antioxidants to substitute for alpha-tocopherol in a number of cellular reactions, the lack of a compensatory antioxidant response in the gene expression under conditions of alpha-tocopherol deficiency, the unique uptake of alpha-tocopherol relative to the other tocopherols and its slower catabolism, and the striking differences in the molecular function of the different tocopherols and tocotrienols, observed in vitro, unrelated to their antioxidant properties, are all data in support of a nonantioxidant molecular function of alpha-tocopherol. Furthermore, in vivo studies have also shown that alpha-tocopherol is not able, at physiological concentrations, to protect against oxidant-induced damage or prevent disease allegedly caused by oxidative damage. Alpha-tocopherol appears to act as a ligand of not yet identified specific proteins (receptors, transcription factors) capable of regulating signal transduction and gene expression.

Regulatory role of vitamins E and C on extracellular matrix components of the vascular system

The protective effect of vitamins E (alpha-tocopherol) and C (L-ascorbic acid) in the prevention of cardiovascular disease (CVD) has been shown in a number of situations but a secure correlation is not universally accepted. Under certain conditions, both, L-ascorbic acid and alpha-tocopherol can exhibit antioxidant properties and thus may reduce the formation of oxidized small molecules, proteins and lipids, which are a possible cause of cellular de-regulation. However, non-antioxidant effects have also been suggested to play a role in the prevention of atherosclerosis. Vitamin E and C can modulate signal transduction and gene expression and thus affect many cellular reactions such as the proliferation of smooth muscle cells, the expression of cell adhesion and extracellular matrix molecules, the production of O(2)(-) by NADPH-oxidase, the aggregation of platelets and the inflammatory response. Vitamins E and C may modulate the extracellular matrix environment by affecting VSMC differentiation and the expression of connective tissue proteins involved in vascular remodeling as well as the maintenance of vascular wall integrity. This review summarizes individually the molecular activities of vitamins E and C on the cells within the connective tissue of the vasculature, which are centrally involved in the maintenance of an intact vascular wall as well as in the repair of atherosclerotic lesions during disease development.

Turning back the clock: regression of abdominal aortic aneurysms via pharmacotherapy

Abdominal aortic aneurysm (AAA) is a common disease that causes progressive expansion and rupture of the aorta with high mortality. There is a large and unmet need for nonsurgical treatment for AAA. Research has shown that an intricate network of inflammatory cells and interstitial cells contributes to the formation of AAA by producing pro-inflammatory mediators that activate enzymes to degrade the extracellular matrix (ECM) and impair ECM biosynthesis. Pharmacological agents such as statins and angiotensin-converting enzyme inhibitors may promote tissue stabilization in AAA by diminishing pro-inflammatory signaling and normalizing metabolism of the ECM. Our recent experiments in animal models demonstrate that inhibition of c-Jun N terminal kinase (JNK) inhibits multiple pathological processes and causes regression of established AAA. Thus, emerging evidence indicates that pharmacological intervention targeting pro-inflammatory signaling and abnormal ECM metabolism is a promising strategy for treatment of AAA.

Connective tissue growth factor expression is regulated by histamine in lung fibroblasts: potential role of histamine in airway remodeling

BACKGROUND

In the inflamed lung of allergic asthma, an aberrant injury-repair response is accompanied by structural changes in the airway, known as airway remodeling. TGF-beta and its downstream mediator connective tissue growth factor (CTGF) are playing a key role in these processes, resulting in irreversible airway remodelling.

OBJECTIVE

As histamine is a key mediator of allergic reactions, we investigated whether histamine is involved in airway remodeling.

METHODS

The effect of histamine and TGF-beta1 on proliferation of lung fibroblast cells IMR-90 was studied by [(3)H]-thymidine proliferation assay. The regulation of CTGF by histamine and TGF-beta1 in lung fibroblasts was analyzed by RT-PCR, real-time PCR, Western blot analysis, and promoter analysis and characterized by specific histamine-receptor antagonists.

RESULTS

Histamine and TGF-beta1 enhanced proliferation of lung fibroblast cells IMR-90. Both induced CTGF mRNA and protein expression with different time kinetics. Whereas TGF-beta1 induced maximal CTGF expression after 12 hours (347% +/- 23%), histamine-induced maximal CTGF expression was lower and delayed (maximum expression of 204% +/- 11% after 48 hours). Histamine and TGF-beta1 stimulated the CTGF promoter and the TGF-beta-response element in the CTGF promoter. The histamine-induced CTGF expression was mediated through the histamine receptor (HR1) and could be completely abolished by TNF-alpha.

CONCLUSIONS

These findings demonstrate that histamine plays a potential role in the induction of airway remodeling mediated by the induction of lung fibroblasts proliferation and CTGF expression.

CLINICAL IMPLICATIONS

This mechanism could be important for prophylactic strategies aiming at airway remodeling and could be a new indication for antihistamine treatment.

The up-regulation of angiotensin II receptor type 1 and connective tissue growth factor are involved in high-glucose-induced fibronectin production by cultured human dermal fibroblasts

BACKGROUND

The expansion of extracellular matrix in diabetes occur in many tissues, including skin, but the underlying mechanisms are poorly understood. We were interested to study whether the activation of angiotensin II/receptor type 1 pathway with the consequent involvement of CTGF may be the possible cause of high-glucose-induced matrix abnormalities in cultured dermal fibroblasts.

OBJECTIVE

We aimed to investigate the effect of high glucose on the generation of angiotensin II and the expression of angiotensin II receptors, and on the expression of CTGF mediating the fibronectin production in cultured human dermal fibroblasts.

METHODS

Cell culturing, ELISA, semi-quantitative RT-PCR, Western blotting.

RESULTS

High glucose treatment of cultured dermal fibroblasts led to: (1) the angiotensin II receptor type 1 was up-regulated at the level of mRNA and protein, unlike the receptor type 2; (2) the generation of angiotensin II and the mRNA expression of all components of the local renin-angiotensin system were not altered; (3) the mRNA and protein expression of CTGF was up-regulated, and this effect was cancelled by losartan; (4) the fibronectin production was increased, also was cancelled by losartan, while an anti-CTGF-neutralizing antibody only partly reduced it; (5) TGFbeta1 expression, the secretion of total and active TGFbeta1 were not changed; (6) the hyperosmotic action of high glucose had no effect.

CONCLUSION

The up-regulation of angiotensin II receptor type 1 and the consequent increase of CTGF expression, independently of TGFbeta1, participate in high-glucose-induced fibronectin production in cultured human dermal fibroblasts.

Role of CCN2/CTGF/Hcs24 in bone growth

Our bones mostly develop through a process called endochondral ossification. This process is initiated in the cartilage prototype of each bone and continues through embryonic and postnatal development until the end of skeletal growth. Therefore, the central regulator of endochondral ossification is the director of body construction, which is, in other words, the determinant of skeletal size and shape. We suggest that CCN2/CTGF/Hcs24 (CCN2) is a molecule that conducts all of the procedures of endochondral ossification. CCN2, a member of the CCN family of novel modulator proteins, displays multiple functions by manipulating the local information network, using its conserved modules as an interface with a variety of other biomolecules. Under a precisely designed four-dimensional genetic program, CCN2 is produced from a limited population of chondrocytes and acts on all of the mesenchymal cells inside the bone callus to promote the integrated growth of the bone. Furthermore, the utility of CCN2 as regenerative therapeutics against connective tissue disorders, such as bone and cartilage defects and osteoarthritis, has been suggested. Over the years, the pathological action of CCN2 has been suggested. Nevertheless, it can also be regarded as another aspect of the physiological and regenerative function of CCN2, which is discussed as well.

High glucose and homocysteine synergistically affect the metalloproteinases-tissue inhibitors of metalloproteinases pattern, but not TGFB expression, in human fibroblasts

AIMS/HYPOTHESIS

Atherosclerosis is particularly aggressive in patients with diabetes. Hyperhomocysteinaemia causes oxidative stress and cytokine secretion: its atherogenic effect is mediated by an enhanced inflammatory response. Matrix metalloproteinases (MMPs) regulate extracellular matrix degradation and remodelling, and contribute to the vulnerability of the atherosclerotic lesion. Fibroblasts contribute to collagen biosynthesis and participate in plaque remodelling via expression and release of MMP2 and MMP9. To explore the role of hyperhomocysteinaemia in cellular pathways involved in plaque growth and stability in diabetic patients, we studied the effect of hyperhomocysteinaemia in human fibroblasts grown in the presence of normal or high glucose concentrations.

MATERIALS AND METHODS

In fibroblasts of five normal subjects, grown at 5.5 or 22 mmol/l glucose and treated with homocysteine, we determined: (1) MMP2, MMP9 and tissue inhibitor of metalloproteinases (TIMP)-1 (an MMP inhibitor) production by western blot analysis; (2) their activity by zymography; (3) TGFB1 expression by real-time PCR; and (4) TGFB, fibronectin and IL6 release by ELISA.

RESULTS

Hyperhomocysteinaemia increased the production and enzymatic activity of MMP2 and MMP9, the effect being more pronounced in high glucose. Conversely, TIMP1 production was reduced by hyperhomocysteinaemia in both conditions, especially in high glucose. Hyperhomocysteinaemia also stimulated IL6 release, at least in part through nuclear factor-kappaB activation. TGFB1 expression was not affected by hyperhomocysteinaemia either in normal or in high glucose.

CONCLUSIONS/INTERPRETATION

Homocysteine upregulates the MMP-TIMP pathway and IL6 release, the effect being stronger in the presence of high glucose. These actions of homocysteine may contribute to the increased atherogenesis observed in diabetic patients with poor metabolic control.

Antagonistic Effects of Oxidized Low Density Lipoprotein and α-Tocopherol on CD36 Scavenger Receptor Expression in Monocytes

Vitamin E deficiency increases expression of the CD36 scavenger receptor, suggesting specific molecular mechanisms and signaling pathways modulated by alpha-tocopherol. We show here that alpha-tocopherol down-regulated CD36 expression (mRNA and protein) in oxidized low density lipoprotein (oxLDL)-stimulated THP-1 monocytes, but not in unstimulated cells. Furthermore, alpha-tocopherol treatment of monocytes led to reduction of fluorescent oxLDL-3,3'-dioctadecyloxacarbocyanine perchlorate binding and uptake. Protein kinase C (PKC) appears not to be involved because neither activation of PKC by phorbol 12-myristate 13-acetate nor inhibition by PKC412 was affected by alpha-tocopherol. However, alpha-tocopherol could partially prevent CD36 induction after stimulation with a specific agonist of peroxisome proliferator-activated receptor-gamma (PPARgamma; troglitazone), indicating that this pathway is susceptible to alpha-tocopherol action. Phosphorylation of protein kinase B (PKB) at Ser473 was increased by oxLDL, and alpha-tocopherol could prevent this event. Expression of PKB stimulated the CD36 promoter as well as a PPARgamma element-driven reporter gene, whereas an inactive PKB mutant had no effect. Moreover, coexpression of PPARgamma and PKB led to additive induction of CD36 expression. Altogether, our results support the existence of PKB/PPARgamma signaling pathways that mediate CD36 expression in response to oxLDL. The activation of CD36 expression by PKB suggests that both lipid biosynthesis and fatty acid uptake are stimulated by PKB.

Increased expression of transglutaminase-1 and PPARgamma after vitamin E treatment in human keratinocytes

In skin, vitamin E acts as the predominant lipophilic antioxidant with a protective function against irradiation and oxidative stress. In addition to that, vitamin E can also modulate signal transduction and gene expression. To study whether the four natural tocopherol analogues (alpha-, beta-, gamma-, delta-tocopherol) can influence transcriptional activity by modulating the activity of nuclear receptors, a human keratinocytes cell line (NCTC 2544) was transfected with plasmids containing the luciferase reporter gene under control by direct repeat elements (DR1-DR4), representing binding sites for four different classes of nuclear receptors. In this model, the tocopherols positively modulated only the reporter construct containing a consensus element for peroxisome proliferator-activated receptors (PPARs). The induction was strongest with gamma-tocopherol and was most likely the direct consequence of stimulation of PPARgamma protein expression in keratinocytes. Vitamin E treatment also led to increased expression of a known PPARgamma target gene involved in terminal keratinocytes differentiation, the transglutaminase-1.

Connective tissue growth factor expression in the human corpus luteum: paracrine regulation by human chorionic gonadotropin

CONTEXT

The molecular mechanisms of luteolysis and its inhibition during maternal recognition of pregnancy remain unclear.

OBJECTIVE

The objective of this study was to investigate the differential regulation of connective tissue growth factor (CTGF) expression in human corpora lutea using in vivo and in vitro models.

DESIGN

Corpora lutea from different stages of the luteal phase and after luteal rescue with human chorionic gonadotropin (hCG) were studied. Primary cultures and cocultures of luteinized granulosa cells and luteal fibroblast-like cells were performed.

SETTING

This study was performed at the research center of a university teaching hospital.

PATIENTS

Women with regular cycles having hysterectomy for nonmalignant conditions and women undergoing oocyte collection for assisted conception were studied.

INTERVENTIONS

CTGF localization was determined by in situ hybridization, and expression by quantitative RT-PCR.

OUTCOMES

The outcome measures were the effect of hCG on the expression and localization of CTGF mRNA in human corpora lutea and the effect of hCG on CTGF expression in primary cultures of luteinized granulosa cells and luteal fibroblast-like cells.

RESULTS

Luteal rescue reduced CTGF expression compared with that in the late luteal phase (P < 0.05). CTGF expression was localized to fibroblast-like cells and endothelial cells of larger blood vessels, not to steroidogenic cells. The expression of CTGF by fibroblast-like cells in vitro was not regulated by hCG. When cocultured with luteinized granulosa cells, fibroblast-like cell CTGF expression was inhibited by hCG (P < 0.001). This effect was independent of stimulated progesterone concentrations and was not blocked by follistatin or indomethacin. Both IL-1alpha (P < 0.05) and cAMP (P < 0.001) inhibited CTGF expression in fibroblast-like cells.

CONCLUSIONS

These results provide evidence for negative regulation of CTGF by hCG during luteal rescue mediated by paracrine signals.

α-Tocopherol-mediated caspase-3 up-regulation enhances susceptibility to apoptotic stimuli

Although alpha-tocopherol is known as an essential micronutrient involved in various oxidative stress-related processes, its non-antioxidant activities have only been characterized in recent years. In this study, we reveal that (+)-alpha-tocopherol [RRR-alpha-tocopherol] enhances cellular susceptibility to both oxidative and non-oxidative apoptosis-inducing stimuli through up-regulation of caspase-3/CPP32 expression in several human cell lines. Exposure of (+)-alpha-tocopherol pretreated cells to known apoptosis-inducing stimuli, such as Fas, H(2)O(2), or etoposide, resulted in an increase in cellular apoptotsis. In addition, (+)-alpha-tocopherol also elevated the pro-caspase-3 protein level and mRNA expression in a time- and dose-dependent manner, while other tocopherol analogues showed no effect. Experiments using a GC-specific DNA binding agent, mithramycin A, and an electrophoretic mobility shift assay demonstrated that Sp1 might mediate the enhanced expression of caspase-3. Our results also confirmed that (+)-alpha-tocopherol promotes the expression, but not the activation, of caspase-3 in various human cell lines. These findings provide biological evidence showing that (+)-alpha-tocopherol can amplify the apoptotic response by up-regulating the expression of pro-caspase-3.

Vitamin E mediates cell signaling and regulation of gene expression

alpha-Tocopherol modulates two major signal transduction pathways centered on protein kinase C and phosphatidylinositol 3-kinase. Changes in the activity of these key kinases are associated with changes in cell proliferation, platelet aggregation, and NADPH-oxidase activation. Several genes are also regulated by tocopherols partly because of the effects of tocopherol on these two kinases, but also independently of them. These genes can be divided in five groups: Group 1. Genes that are involved in the uptake and degradation of tocopherols: alpha-tocopherol transfer protein, cytochrome P450 (CYP3A), gamma-glutamyl-cysteine synthetase heavy subunit, and glutathione-S-transferase. Group 2. Genes that are implicated with lipid uptake and atherosclerosis: CD36, SR-BI, and SR-AI/II. Group 3. Genes that are involved in the modulation of extracellular proteins: tropomyosin, collagen-alpha-1, MMP-1, MMP-19, and connective tissue growth factor. Group 4. Genes that are connected to adhesion and inflammation: E-selectin, ICAM-1 integrins, glycoprotein IIb, IL-2, IL-4, IL-1b, and transforming growth factor-beta (TGF-beta). Group 5. Genes implicated in cell signaling and cell cycle regulation: PPAR-gamma, cyclin D1, cyclin E, Bcl2-L1, p27, CD95 (APO-1/Fas ligand), and 5a-steroid reductase type 1. The transcription of p27, Bcl2, alpha-tocopherol transfer protein, cytochrome P450 (CYP3A), gamma-glutamyl-cysteine sythetase heavy subunit, tropomyosin, IL-2, and CTGF appears to be upregulated by one or more tocopherols. All the other listed genes are downregulated. Gene regulation by tocopherols has been associated with protein kinase C because of its deactivation by alpha-tocopherol and its contribution in the regulation of a number of transcription factors (NF-kappaB, AP1). A direct participation of the pregnane X receptor (PXR) / retinoid X receptor (RXR) has been also shown. The antioxidant-responsive element (ARE) and the TGF-beta-responsive element (TGF-beta-RE) appear in some cases to be implicated as well.

Vitamin E: Textbooks require updating

Vitamin E was discovered in 1922, but in more than 60 years many new findings have added to the early one. However, its description in many textbooks has not been proportionally updated. The result is an inaccurate, incomplete, and often incorrect description of the function of this vitamin. In some other textbooks, vitamin E is absolutely neglected. In almost all books the existence of vitamin E deficiency diseases is ignored. Recent findings on vitamin E molecular functions and its related diseases are described in this article.

Chemistry and biology of vitamin E

Our understanding of the role of vitamin E in human nutrition, health, and disease has broadened and changed over the past two decades. Viewed initially as nature's most potent lipid-soluble antioxidant (and discovered for its crucial role in mammalian reproduction) we have now come to realize that vitamin E action has many more facets, depending on the physiological context. Although mainly acting as an antioxidant, vitamin E can also be a pro-oxidant; it can even have nonantioxidant functions: as a signaling molecule, as a regulator of gene expression, and, possibly, in the prevention of cancer and atherosclerosis. Since the term vitamin E encompasses a group of eight structurally related tocopherols and tocotrienols, individual isomers have different propensities with respect to these novel, nontraditional roles. The particular beneficial effects of the individual isomers have to be considered when dissecting the physiological impact of dietary vitamin E or supplements (mainly containing only the alpha-tocopherol isomer) in clinical trials. These considerations are also relevant for the design of transgenic crop plants with the goal of enhancing vitamin E content because an engineered biosynthetic pathway may be biased toward formation of one isomer. In contrast to the tremendous recent advances in knowledge of vitamin E chemistry and biology, there is little hard evidence from clinical and epidemiologic studies on the beneficial effects of supplementation with vitamin E beyond the essential requirement.

Expression profiling of cardiovascular disease

Cardiovascular disease is the most important cause of morbidity and mortality in developed countries, causing twice as many deaths as cancer in the USA. The major cardiovascular diseases, including coronary artery disease (CAD), myocardial infarction (MI), congestive heart failure (CHF) and common congenital heart disease (CHD), are caused by multiple genetic and environmental factors, as well as the interactions between them. The underlying molecular pathogenic mechanisms for these disorders are still largely unknown, but gene expression may play a central role in the development and progression of cardiovascular disease. Microarrays are high-throughput genomic tools that allow the comparison of global expression changes in thousands of genes between normal and diseased cells/tissues. Microarrays have recently been applied to CAD/MI, CHF and CHD to profile changes in gene expression patterns in diseased and non-diseased patients. This same technology has also been used to characterise endothelial cells, vascular smooth muscle cells and inflammatory cells, with or without various treatments that mimic disease processes involved in CAD/MI. These studies have led to the identification of unique subsets of genes associated with specific diseases and disease processes. Ongoing microarray studies in the field will provide insights into the molecular mechanism of cardiovascular disease and may generate new diagnostic and therapeutic markers.