Ex vivo Anti-Senescence Activity of N-Acetylcysteine in Visceral Adipose Tissue of Obese Volunteers.

INTRODUCTION: Excessive visceral adiposity is known to drive the onset of metabolic derangements, mostly involving oxidative stress, prolonged inflammation, and cellular senescence. N-acetylcysteine (NAC) is a synthetic form of l-cysteine with potential antioxidant, anti-inflammatory, and anti-senescence properties. This ex-vivo study aimed to determine the effect of NAC on some markers of senescence including ß-galactosidase activity and p16, p53, p21, IL-6, and TNF-α gene expressions in visceral adipose tissue in obese adults. METHODS: This ex-vivo experimental study involved 10 obese participants who were candidates for bariatric surgery. Duplicate biopsies from the abdominal visceral adipose tissue were obtained from the omentum. The biopsies were treated with or without NAC (5 and 10 mm). To evaluate adipose tissue senescence, beta-galactosidase (ß-gal) activity and the expression of P16, P21, P53, IL-6, and TNF-α were determined. ANOVA test was employed to analyze the varying markers of cellular senescence and inflammation between treatment groups. RESULTS: The NAC at concentrations of 5 mm and 10 mm resulted in a noteworthy reduction ß-gal activity compared to the control group (p < 0.001). Additionally, the expression of P16, P21, and IL-6 was significantly reduced following treatment with NAC (5 mm) and NAC (10 mm) compared to the control group (All p < 0.001). DISCUSSION/CONCLUSION: Taken together, these data suggest the senotherapeutic effect of NAC, as it effectively reduces the activity of SA-ß-gal and the expression of IL-6, P16, and P21 genes in the visceral adipose tissue of obese individuals.

The interplay between obesity, immunosenescence, and insulin resistance.

Obesity, which is the accumulation of fat in adipose tissue, has adverse impacts on human health. Obesity-related metabolic dysregulation has similarities to the metabolic alterations observed in aging. It has been shown that the adipocytes of obese individuals undergo cellular aging, known as senescence. Senescence can be transmitted to other normal cells through a series of chemical factors referred to as the senescence-associated secretory phenotype (SASP). Most of these factors are pro-inflammatory compounds. The immune system removes these senescent T-cells, but immunosenescence, which is the senescence of immune cells, disrupts the clearance of senescent T-cells. Immunosenescence occurs as a result of aging or indirectly through transmission from senescent tissues. The significant occurrence of senescence in obesity is expected to cause immunosenescence and impairs the immune response to resolve inflammation. The sustained and chronic inflammation disrupts insulin's metabolic actions in metabolic tissues. Therefore, this review focuses on the role of senescent adipocyte cells in obesity-associated immunosenescence and subsequent metabolic dysregulation. Moreover, the article suggests novel therapeutic approaches to improve metabolic syndrome by targeting senescent T-cells or using senotherapeutics.

Alterations of DNA methylation and expression of genes related to thyroid hormone metabolism in colon epithelium of obese patients.

BACKGROUND: Colorectal cancer is common among obese individuals. The purpose of the current study was to determine changes in DNA methylation status and mRNA expression of thyroid hormone receptor beta (THRB), as a tumor suppressor, and thyroid hormone inactivating enzyme, type 3 deiodinase (DIO3) genes, in human epithelial colon tissues of healthy obese individuals. METHODS: Colon biopsies were analyzed by methylation sensitive-high resolution melting (MS-HRM) to investigate promoter methylation of DIO3 and THRB, and by quantitative real-time polymerase chain reaction to assay expression of DIO3 and THRB mRNA on eighteen obese and twenty-one normal-weight healthy men. RESULTS: There was no significant difference in mean methylation levels at the THRB promoter region between the two groups. Nevertheless, obesity decreased THRB expression levels, significantly (P < 0.05; fold change: 0.19). Furthermore, obesity attenuated DNA methylation (P < 0.001) and enhanced mRNA expression of DIO3 (P < 0.05; fold change: 3). CONCLUSIONS: Our findings suggest that obesity may alter expression of THRB and DIO3 genes through epigenetic mechanism. Alterations of THRB and DIO3 expressions may predispose colon epithelium of obese patients to neoplastic transformation.

The Effects of Ovalbumin on Proliferation, Migration, and Stemness Properties of Chemoresistant SW480 Colon Cancer Cells.

Egg peptides are factors in the embryonic environment with many significant biological activities, such as anticancer activity. Therefore, the current study investigates the effect of egg ovalbumin (OVA) on survival, cell cycle, self-renewal ability, stemness properties, and migration in SW480 colon cancer cells and 5-fluorouracil (5FU) resistant subgroup. MTT test was performed to assess cell viability. Flow cytometry was employed to analyze the cell cycle. Clonogenic assay and spheroid formation were used to assess the effect of OVA on self-renewal and stemness properties. Wound healing assay and RT-PCR were performed to analyze migration and gene mRNA expression. We demonstrated that OVA (8 and 12 mg/ml) attenuated cell viability, induced cell-cycle arrest, inhibited colony formation, and non-significantly reduced spheroid formation and migration in both cell lines. Furthermore, OVA downregulated the expression of Nanog, c-Myc, and NDRG1 in both cells, suggesting a stemness and self-renewal attenuation by OVA. In conclusion, OVA exposure inhibited the 5FU-SW480 chemo-resistant subpopulation growth by inducing cell cycle arrest and diminishing self-renewal and partially stemness properties of colon cancer cells.

Selective thyroid hormone receptor beta agonist, GC-1, is capable to reduce growth of colorectal tumor in syngeneic mouse models.

OBJECTIVE: The effect of thyroid hormone (TH) on cancers was proposed more than 100 years ago; however, conclusions are conflicting. THs are precisely regulated at tissue and cellular levels. It seems that this regulation is altered in cancers. Thyroid hormone receptor beta (TRß) has anti-proliferative and tumor-suppressive effects in many cancer cells. Therefore, we decided to investigate thyroid hormone receptor beta (THRB) expression and activation by the selective agonist, GC-1, on tumor growth in a syngeneic mouse model of colorectal cancer (CRC) and colon cell lines. METHODS: In vitro cell viability assay using MTT analysis, cell cycle analysis by PI staining, and FACS analysis were performed. In vivo tumor growth measurements were carried out by caliper and [18F] Fluoro-2-deoxy-2-D-glucose (FDG) - PET imaging. Gene expressions were determined using quantitative-PCR. RESULTS: Some concentrations of GC-1 had a marked negative effect on the cell viability of colorectal cell lines. Cell cycle analysis showed that the anti-proliferative effect of GC-1 may not result from cell cycle arrest or apoptosis. Tumor growth analysis in mice harboring colorectal tumor showed that GC-1 treatment for 8 d profoundly inhibited tumor growth and 18FDG uptake. THRB expression was decreased in mice tumor; however, it was upregulated following GC-1 administration. CONCLUSIONS: Our results showed that specific activation of TRß by GC-1 had negative effect on tumor growth and restored its gene expression in tumors of CRC mice model.

Colorectal cancer causes alteration of thyroid hormone profile in newly diagnosed patients.

OBJECTIVES: Subcellular alteration of thyroid hormones (THs) signaling is proposed in many types of cancers. Some studies show deiodinase type 3, as an oncofetal protein, re-expresses in some cancer types. Therefore, we aimed to investigate the product of this enzyme, reverse triiodothyronine (rT3) in serum of newly diagnosed colorectal cancer (CRC) patients. METHODS: In this cross-sectional study, blood from 38 laboratory-confirmed cases was taken, and serum levels of rT3, total T3 (triiodothyronine), total T4 (thyroxine), free T3, free T4, and thyroid-stimulating hormone (TSH) were detected by using an enzyme-linked immunosorbent assay. RESULTS: The results illustrated that rT3 and free T3 levels increased in patients with early stages of colorectal cancer, despite normal levels of total T3, total T4, free T4, and TSH. CONCLUSION: The elevation of rT3 in CRC patients can probably be due to the re-expression of deiodinase type 3 in CRC. Further research is needed to study the role of intracellular THs modulation in CRC and its impact on CRC treatment.

Correlation of Low Levels of α-1 Antitrypsin and Elevation of Neutrophil to Lymphocyte Ratio with Higher Mortality in Severe COVID-19 Patients.

BACKGROUND: Variations in COVID-19 prevalence, severity, and mortality rate remain ambiguous. Genetic or individual differences in immune response may be an explanation. Moreover, hyperinflammation and dysregulated immune response are involved in the etiology of severe forms of COVID-19. Therefore, the aim of the present study was to analyze serum alpha-1 antitrypsin (AAT) levels, as an acute-phase plasma protein with immunomodulatory effect and neutrophil to lymphocyte ratio (NLR) as a marker of inflammation response in severe COVID-19 illness. METHODS: In this retrospective observational cohort study, 64 polymerase chain reaction (PCR) positive COVID-19 hospitalized patients were studied for AAT, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), troponin, complete blood count (CBC), random blood sugar, serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), and arterial oxygen saturation (O2sat) at admission and during hospitalization. RESULTS: The results showed that hospitalized patients with COVID-19 had low serum levels of AAT and high CRP levels at the first days of hospitalization. In particular, the percentages of individuals with low, normal, and high AAT levels were 7.80%, 82.80%, and 9.40%, respectively, while high and low values of CRP accounted for 86.70% and 13.30% of patients. Most of the patients had an upward neutrophil to lymphocyte ratio (NLR) trend, with a higher mortality rate (p < 0.05) and troponin levels (p < 0.05). However, comorbidities, CRP alterations, ESR alterations, nonfasting blood sugar, SGOT, SGPT, O2sat, RBC, and PLT values were not significantly different between the NLR downward and upward trend groups. CONCLUSIONS: The current study revealed that severe COVID-19 patients had low serum AAT levels related to CRP values. Therefore, AAT response may be considered as a new mechanism by which some COVID-19 patients show immune dysregulation and more severe symptoms.

Grape seed extract supplementation along with a restricted-calorie diet improves cardiovascular risk factors in obese or overweight adult individuals: A randomized, placebo-controlled trial.

Grape seed extract (GSE) is a flavonoid-rich supplement, recently discussed as a potential moderator of inflammation and obesity. In this study, we aimed to investigate the effects of GSE supplementation along with a restricted-calorie diet (RCD), on changes in blood lipid profile, visceral adiposity index (VAI), and atherogenic index of plasma (AIP). We designed a randomized, double-blinded, placebo-controlled clinical trial. Forty obese or overweight individuals (25 ≤ body mass index < 40 kg/m2 ) were randomly assigned to receive GSE (300 mg/day) or placebo, plus RCD, for 12 weeks. We studied the anthropometric measures, biochemical biomarkers and dietary intake within the study timelines. Levels of high-density lipoprotein cholesterol (HDL-C) and HDL-C/low-density lipoprotein cholesterol (LDL-C) significantly increased in the GSE group as compared with the placebo group at week 12 (p = .03 and .008, respectively, adjusted for age, sex, energy and saturated fatty acid intake). We also observed a significant reduction in LDL-C following GSE supplementation in comparison to placebo (adjusted for age, sex and energy intake, p = .04). VAI, AIP, total cholesterol and triglyceride significantly decreased in the GSE group compared with the baseline (p = .04, .02, .01, and .02, respectively). GSE supplementation may have a modulatory role in improving blood lipid profile in obese or overweight individuals, when accompanied by RCD.

Inhibitory effect of chrysin on estrogen biosynthesis by suppression of enzyme aromatase (CYP19): A systematic review.

The cytochrome P450 enzyme functions as the rate-limiting enzyme in changing androgens to estrogens. Inhibition of aromatase is one of the significant objectives of treatment of hormone-dependent diseases such as breast cancer, especially in post-menopausal women. Natural compounds like chrysin, as a flavor that has a high concentration in honey and propolis, are rich sources of them can be useful in inhibiting aromatase for chemoprevention following treatment or in women at risk of acquiring breast cancer. This study intended to summarize the existing evidence on the effect of chrysin on aromatase activity. We systematically searched Science Direct, PubMed and Google Scholar and hand searched the reference lists of identified relevant articles, up to 5 February, 2019. Articles with English abstracts that reported the effect of chrysin on aromatase inhibition and without publication date restriction were investigated. Twenty relevant articles were chosen from a total of 1721 articles. Only one study was performed on humans and two studies were assayed on rats, while other studies were evaluated in vitro. All the studies except one showed that chrysin had the potency of aromatase inhibition; however, only one study performed on endometrial stromal cells showed that chrysin and naringenin did not indicate aromatase inhibitory properties. Various assay methods and experimental conditions were the important aspects leading to different results between the studies. Chrysin has potency in inhibition of the aromatase enzyme and thus can be useful in preventing and treating the hormone-dependent breast cancer and as an adjuvant therapy for estrogen-dependent diseases.

Zinc supplementation improves body weight management, inflammatory biomarkers and insulin resistance in individuals with obesity: a randomized, placebo-controlled, double-blind trial.

BACKGROUND: The present study was designed to determine whether zinc supplementation would increase the effects of restricted calorie diet (RCD) on obesity. METHODS AND MATERIALS: A randomized, double-blind clinical trial was performed on 40 obese subjects who were randomly assigned to receive zinc supplements (30 mg/day) or placebo for a period of 15-weeks. Both groups were under a restricted calorie diet (~ 300 kcal lower than the estimated energy requirement). Anthropometric measurements, biochemical markers, appetite, and dietary intakes were determined during the study period. RESULTS: The reductions of body weight, body mass index, waist circumference, and hip circumference were significantly higher in the zinc group compared to the placebo group (P = 0.032, 0.025, 0.003, and 0.0001, respectively). Lower levels of high sensitivity C-reactive protein, apelin, homeostatic model assessment of insulin resistance (HOMA-IR), and appetite score were observed in the zinc group in comparison with the placebo group (P = 0.0001, 0.001, 0.031 and 0.001 respectively). CONCLUSION: This study indicates that Zn supplementation with a restricted calorie diet has favorable effects in reducing anthropometric measurements, inflammatory markers, insulin resistance and appetite in individuals with obesity, and may play an effective role in the treatment of obesity.Trial registration This clinical trial was registered at clinicaltrials.gov at the U.S. National Library of Medicine (NCT02516475).

The prevalence of food addiction and its associations with plasma oxytocin level and anthropometric and dietary measurements in Iranian women with obesity.

Obesity is a prevalent public health problem, and food addiction (FA) is one of the most controversial factors in its management. Therefore, this study was designed to validate an FA questionnaire for Iranian women with obesity and to determine the prevalence of FA and its associations with plasma oxytocin (OT) levels as well as anthropometric and dietary measurements. In this descriptive-analytical study, 450 adult women with obesity were included. The prevalence of FA was determined with a valid Yale food addiction scale (YFAS). Macronutrient intakes were measured by a valid semi-quantitative food frequency questionnaire (FFQ). In addition, plasma OT was measured after eight hours of fasting. In this study, the prevalence of FA was 26.2% in women with obesity. In comparison with class I obesity, the odds ratios (95% CI) of FA for class II and class III obesity were 2.5 (CI: 1.29-5.09) and 3.3 (CI: 1.69-6.4) respectively. Dietary intakes of energy, protein, carbohydrate, fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and cholesterol were significantly higher in food-addicted (FAD) women compared to non-food-addicted (NFA) ones (p < 0.001). Moreover, plasma OT level was lower in FAD women with obesity than in NFA subjects (p = 0.02). In conclusion, the results of this study indicate that FA is prevalent in Iranian women with obesity. In addition, FA is related to obesity severity, dietary intakes of energy, carbohydrate, protein, fat, cholesterol, and plasma OT level.

Beta-Hydroxybutyrate Promotes Proliferation, Migration and Stemness in a Subpopulation of 5FU Treated SW480 Cells: Evidence for Metabolic Plasticity in Colon Cancer

Background: Beta-hydroxybutyrate (BHB) as a ketone body is the metabolic fuel in oxidative phosphorylation pathway. So far the effects of BHB on the biology of tumor cells is contradictory. Therefore, we investigated the effect of BHB on viability, metabolism, proliferation and migration of 5FU treated SW480 colon cancer cell line. Methods: we treated the SW480 cells with IC50 dose of 5-fluorouracil (5FU) for 72 h to isolate a subpopulation of 5FU treated cells that were resistant to it. Effects of BHB on cell viability was investigated by MTT assay. Measurement of oxygen consumption rate (OCR) in parallel with extracellular acidification rate (ECAR) upon BHB treatment was used for determination of metabolic profile of these cells. Investigating the relationship between metabolic phenotype and the status of differentiation and stemness was done by analyzing the expression of PGC-1α, c-MYC, NANOG, ALPi and KRT20 genes by qRT-PCR. Clonogenic and scratch assay were performed to determine the proliferation and migration abilities of incubated with BHB compared to untreated cells. Results: BHB increased cell viability in SW480 and 5FU treated SW480 cells. The results showed a significantly decreased ECAR and increased OCR in both cell types following BHB treatment reflecting the superiority of oxidative phosphorylation profile compared to glycolysis in both cell types. Also, treatment with BHB increases the expression of genes normally associated with stemness and mitochondrial biogenesis and decreases the expression of genes related to glycolytic program and differentiation in 5FU treated cells. Self-renewal and migration potential of BHB treated cells increased significantly. Conclusion: These findings suggest that BHB utilization via oxidative mitochondrial metabolism can fuel proliferation, migration and stemness in 5FU treated SW480 colon cancer cells.

Obesity-induced p53 activation in insulin-dependent and independent tissues is inhibited by beta-adrenergic agonist in diet-induced obese rats.

AIMS: The purpose of this study was to assay the role of beta-adrenergic receptor signaling in the regulation of obesity-induced p53 in high fat feeding obese rats. MAIN METHODS: The role of beta-adrenergic receptor/cyclic AMP in the regulation of p53 and its downstream mediators was evaluated by western blot and real-time quantitative RT-PCR among diet induced rats. KEY FINDINGS: Beta-adrenergic receptor agonist, isoproterenol, and an adenylate cyclase activator, forskolin, at a single dose significantly reduced insulin resistance consistent with a decrease in total and phospho-p53 levels in insulin and non-insulin metabolic target tissues. The decrease of p53 signaling was consistent with the elevation of AKT and subsequent activation. Obese rats exposed to fasting also exhibited improvement in insulin action despite a slight effect on p53 level. SIGNIFICANCE: Results of the present study obviously showed that beta-adrenergic receptor agonist/cAMP prevented obesity-induced p53 activation. Although this effect in metabolic insulin target tissues tempted us to consider them as insulin sensitizers in obesity-related diabetes, p53 inhibition in non-insulin target tissues warned about the impairment of anti-cancer mechanisms in obese subjects.

PTEN over-expression by resveratrol in acute lymphoblastic leukemia cells along with suppression of AKT/PKB and ERK1/2 in genotoxic stress.

The bioactive components of dietary phytochemicals are in the spotlight of research institutes, due to their significant antioxidant activities and health-promoting properties. Resveratrol is a polyphenol which is found abundantly in grapes and berries and has long been known as a chemo-preventive agent. The main purpose of this study was to provide a new mechanistic insight into the growth inhibition of acute lymphoblastic leukemia cells by resveratrol along with a DNA damage agent. It was found that the treatment of pre-B ALL cells by resveratrol in the presence or absence of doxorubicin resulted in decreased cell viability and a synergistic increase in cytotoxicity. Cell death was accompanied by a significant increase in phosphorylated p53 at serine 15 and accumulation of PTEN. In addition, resveratrol inhibited the over-expression of p-AKT and p-ERK1/2. These findings clearly demonstrated that resveratrol and doxorubicin synergistically increase the cytotoxicity of pre-B ALL cells via the hyper-activation of two important tumor suppressor proteins and two major signal transduction pathways.

PI3K/AKT and Mdm2 activation are associated with inhibitory effect of cAMP increasing agents on DNA damage-induced cell death in human pre-B NALM-6 cells.

DNA damage response (DDR) consists of both proapoptotic and prosurvival signaling branches. Superiority of each signaling branch determines the outcome of DNA damage: death or allowing the repair. The present authors have previously shown that an increased intracellular level of cAMP disrupts p53-mediated apoptosis in human pre-B NALM-6 cells and inhibition of NF-κB prevents prosurvival effect of cAMP during DNA damage. AKT/PKB (protein kinase B) is a general mediator of survival signaling. AKT signaling inhibits p53-mediated transcription and apoptosis. The results of present study showed that cAMP disrupted DNA damage/p53-mediated apoptosis through AKT and subsequent NF-κB activation. These results suggested that AKT may be found as part of a complex with scaffolding proteins, beta-arrestins and PDE4D. cAMP disarticulated the complex through binding to PDE4D compartment. It seems that release of AKT protein potentiated DDR activated pro-survival AKT in NALM-6 cells. Taken together, the present data indicated that regulation of AKT signaling may determine the fate of cells exposed to genotoxic stress.