The resveratrol attenuates ethanol-induced hepatocyte apoptosis via inhibiting ER-related caspase-12 activation and PDE activity in vitro

The protective role of resveratrol against high glucose-induced oxidative stress and apoptosis in HepG2 cells

High glucose concentrations result in oxidative stress, leading to damage of cellular constituents like DNA, proteins, and lipids, ultimately resulting in apoptosis. Resveratrol, a polyphenol phytoalexin, has been studied for its potential therapeutic effects on diabetes. This study investigated the influence of high glucose (HG) on HepG2 cells and assessed resveratrol's effect on high-glucose-induced oxidative stress and apoptosis. HepG2 cells were cultured for 48 and 72 h with high glucose (40 mM), low resveratrol (25 μM), high resveratrol (50 μM), high glucose + low resveratrol, and high glucose + high resveratrol. After exposure, oxidative and apoptosis-related gene expression was evaluated using quantitative polymerase chain reaction (qPCR), and lactate dehydrogenase (LDH) release was measured using the supernatant. In HepG2 cells cultured with high glucose, all antioxidant enzymes (SOD, superoxide dismutase; GPx1, glutathione peroxidase 1; CAT, catalase; Nrf2, nuclear factor erythroid 2-related factor 2; and NQO1, NAD(P)H quinone oxidoreductase 1) were significantly reduced; however, when HepG2 cells were cultured with resveratrol (25 and 50 μM) and high glucose, the expression levels of all antioxidant enzymes were increased. The anti-apoptotic gene (B-cell lymphoma 2; Bcl2) and the DNA repair gene (Oxoguanine glycosylase-1, OGG1) were significantly decreased following high glucose exposure to HepG2 cells. Surprisingly, the expression levels of Bcl2 and OGG1 were notably elevated after resveratrol treatment. Furthermore, high glucose levels increased the LHD release in HepG2 cells, whereas resveratrol treatment reduced the LDH release. Our results demonstrate that resveratrol provides protection against oxidative stress and apoptosis induced by high glucose in HepG2 cells. Hence, resveratrol shows potential as an effective approach to address the impaired antioxidant response resulting from elevated glucose levels commonly observed in diabetes and metabolic disorders.

A 700 nm LED Light Activated Ru(II) Complex Destroys Tumor Cytoskeleton via Photosensitization and Photocatalysis

Photoactivable chemotherapy (PACT) using metallic complexes provides spatiotemporal selectivity over drug activation for targeted anticancer therapy. However, the poor absorption in near-infrared (NIR) light region of most metallic complexes renders tissue penetration challenging. Herein, an NIR light triggered dinuclear photoactivable Ru(II) complex (Ru2) is presented and the antitumor mechanism is comprehensively investigated. The introduction of a donor-acceptor-donor (D-A-D) linker greatly enhances the intramolecular charge transition, resulting in a high molar extinction coefficient in the NIR region with an extended triplet excited state lifetime. Most importantly, when activated by 700 nm NIR light, Ru2 exhibits unique slow photodissociation kinetics that facilitates synergistic photosensitization and photocatalytic activity to destroy diverse intracellular biomolecules. In vitro and in vivo experiments show that when activated by 700 nm NIR light, Ru2 exhibits nanomolar photocytotoxicity toward 4T1 cancer cells via the induction of calcium overload and endoplasmic reticulum (ER) stress. These findings provide a robust foundation for the development of NIR-activated Ru(II) PACT complexes for phototherapeutic application.

Regulation of endoplasmic reticulum stress by hesperetin: Focus on antitumor and cytoprotective effects

BACKGROUND

Cancer is still an all-times issue due to a large and even increasing number of deaths. Impaired genes regulating cell proliferation and apoptosis are targets for the development of novel cancer treatments.

HYPOTHESIS

Increased transcription of NADPH oxidase activator (NOXA), Bcl2-like11 (BIM), BH3-only proteins and p53 unregulated apoptosis modulator (PUMA) is caused by the imbalance between pro- and anti-apoptotic Bcl-2 proteins due to endoplasmic reticulum (ER) stress. The membranous network of ER is present in all eukaryotic cells. ER stress facilitates the interaction between Bax and PUMA, triggering the release of cytochrome C. As a main intracellular organelle, ER is responsible for translocation as well as post-translation modification and protein folding.

RESULTS

Hesperetin is a cytoprotective flavonone, which acts against ER stress and protects from cell damage induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Hesperetin inhibits lipid peroxidation induced by Fe²⁺ and l-ascorbic acid in rat brain homogenates.

CONCLUSION

This review deals with the anticancer effects of hesperetin regarding the regulation of ER stress as a principal mechanism in the pathogenesis of tumors.

Honokiol regulates endoplasmic reticulum stress by promoting the activation of the sirtuin 1-mediated protein kinase B pathway and ameliorates high glucose/high fat-induced dysfunction in human umbilical vein endothelial cells

Honokiol plays an important role in anti-oxidation, but its role in diabetic vascular complications is unclear. In this study, the effects of honokiol in high glucose/high fat (HG/HF)-induced human umbilical vein endothelial cells (HUVECs) were explored. After pre-treatment with honokiol, the cells were transferred to an HG/HF medium, and cell viability and apoptosis were respectively measured by methyl tetrazolium and flow cytometry. Moreover, the contents of reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) were measured. The expressions of C/EBP homologous protein (CHOP), glucose-regulated protein 78 (GRP78), phosphorylated-protein kinase RNA-like endoplasmic reticulum kinase (p-PERK), phosphorylated-inositol requiring enzyme-1α (p-IRE1α), cleaved caspase-3 and SIRT1 were determined by Western blot or quantitative reverse transcription PCR, respectively. Finally, the viability, apoptosis, and the contents of ROS, MDA, and SOD, as well as the expressions of CHOP, GRP78, p-PERK, p-IRE1α, cleaved caspase-3, Akt, p-Akt, and SIRT1 in the cells transfected with small interfering RNA SIRT1 (siSIRT1) were detected by the previously mentioned methods. Honokiol reversed the effect of HG/HF on promoting cell apoptosis, ROS and MDA contents, and the expressions of CHOP, GRP78, p-PERK, p-IRE1α and cleaved caspase-3, and also reversed the inhibitory effect of HG/HF on cell viability, SOD content and SIRT1 expression. However, siSIRT1 reversed the above effects caused by honokiol. Honokiol activated SIRT1 promoter. SIRT1 interacted with Akt, consequently promoting the activity of Akt. Therefore, honokiol activates the Akt pathway by regulating SIRT1 expression to regulate endoplasmic reticulum stress, promotes cell viability and inhibits the apoptosis of HG/HF-induced HUVECs.

Resveratrol Alleviates the Inhibitory Effect of Tunicamycin-Induced Endoplasmic Reticulum Stress on Expression of Genes Involved in Thyroid Hormone Synthesis in FRTL-5 Thyrocytes

Recently, ER stress induced by tunicamycin (TM) was reported to inhibit the expression of key genes involved in thyroid hormone synthesis, such as sodium/iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and their regulators such as thyrotropin receptor (TSHR), thyroid transcription factor-1 (TTF-1), thyroid transcription factor-2 (TTF-2) and paired box gene 8 (PAX-8), in FRTL-5 thyrocytes. The present study tested the hypothesis that resveratrol (RSV) alleviates this effect of TM in FRTL-5 cells. While treatment of FRTL-5 cells with TM alone (0.1 µg/mL) for 48 h strongly induced the ER stress-sensitive genes heat shock protein family A member 5 (HSPA5) and DNA damage inducible transcript 3 (DDIT3) and repressed NIS, TPO, TG, TSHR, TTF-1, TTF-2 and PAX-8, combined treatment with TM (0.1 µg/mL) and RSV (10 µM) for 48 h attenuated this effect of TM. In conclusion, RSV alleviates TM-induced ER stress and attenuates the strong impairment of expression of genes involved in thyroid hormone synthesis and their regulators in FRTL-5 thyrocytes exposed to TM-induced ER stress. Thus, RSV may be useful for the treatment of specific thyroid disorders, provided that strategies with improved oral bioavailability of RSV are applied.

Inonotus obliquus extract alleviates myocardial ischemia/reperfusion injury by suppressing endoplasmic reticulum stress

Inonotus obliquus (IO) is an edible fungus that exerts various biological functions, including anti‑inflammatory, antitumor and immunomodulatory effects. The present study was designed to investigate the role of IO extract (IOE) in myocardial ischemia/reperfusion (MI/R) and determine the exact molecular mechanisms. The left anterior descending coronary artery was ligated to establish the MI/R injury model in rats. IOE exhibited a novel cardioprotective effect, as shown by improvement in cardiac function and decrease in infarct size. Pretreatment with IOE activated antioxidant enzymes in cardiomyocytes, including glutathione peroxidase, superoxide dismutase and catalase. IOE pretreatment also induced the upregulation of NAD‑dependent protein deacetylase sirtuin‑1 (SIRT1) and downregulation of glucose‑regulated protein 78, phosphorylated (p‑) protein kinase R‑like endoplasmic reticulum kinase, p‑eukaryotic translation initiation factor 2 subunit α, C/EBP homologous protein and caspase‑12. Furthermore, IOE alleviated endoplasmic reticulum (ER) stress‑induced apoptosis in cardiomyocytes by decreasing the mRNA levels of caspase‑12. IOE inhibited apoptosis induced by overexpression of pro‑caspase‑9 and pro‑caspase‑3. In summary, IOE pretreatment protects the heart against MI/R injury through attenuating oxidative damage and suppressing ER stress‑induced apoptosis, which may be primarily due to SIRT1 activation.

Endoplasmic reticulum stress in doxorubicin-induced cardiotoxicity may be therapeutically targeted by natural and chemical compounds: A review

Doxorubicin (DOX) is a chemotherapeutic agent with marked, dose-dependent cardiotoxicity that leads to tachycardia, atrial and ventricular arrhythmia, and irreversible heart failure. Induction of the endoplasmic reticulum (ER) which plays a major role in protein folding and calcium homeostasis was reported as a key contributor to cardiac complications of DOX. This article reviews several chemical compounds that have been shown to regulate DOX-induced inflammation, apoptosis, and autophagy via inhibition of ER stress signaling pathways, such as the IRE1α/ASK1/JNK, IRE1α/JNK/Beclin-1, and CHOP pathways.

An Overview of the Mechanism of Penthorum chinense Pursh on Alcoholic Fatty Liver

Alcohol liver disease (ALD) caused by excessive alcohol consumption is a progressive disease, and alcohol fatty liver disease is the primary stage. Currently, there is no approved drug for its treatment. Abstinence is the best way to heal, but patients' compliance is poor. Unlike other chronic diseases, alcohol fatty liver disease is not caused by nutritional deficiencies; it is caused by the molecular action of ingested alcohol and its metabolites. More and more studies have shown the potential of Penthorum chinense Pursh (PCP) in the clinical use of alcohol fatty liver treatment. The purpose of this paper is to reveal from the essence of PCP treatment of alcohol liver mechanism mainly by the ethanol dehydrogenase (ADH) and microsomal ethanol oxidation system-dependent cytochrome P4502E1 (CYP2E1) to exert antilipogenesis, antioxidant, anti-inflammatory, antiapoptotic, and autophagy effects, with special emphasis on its mechanisms related to SIRT1/AMPK, KEAP-1/Nrf2, and TLR4/NF-κB. Overall, data from the literature shows that PCP appears to be a promising hepatoprotective traditional Chinese medicine (TCM).

Resveratrol decreases high glucose‑induced apoptosis in renal tubular cells via suppressing endoplasmic reticulum stress

Diabetic nephropathy (DN) is the second most common complication of diabetes mellitus after cardiovascular complications. Endoplasmic reticulum (ER) stress is known to be associated with DN. Resveratrol (RSV) exhibits anti-oxidative, anti-inflammatory and cytoprotective effects. Therefore, the aims of the present study were to investigate the role of RSV in the inhibition of high concentration glucose (HG)-induced apoptosis in renal tubular cells, as well as to examine the protective effects of RSV against diabetes-mediated renal damage via inhibition of ER stress in DN. RSV was orally administered to diabetic db/db mice once a day for 12 consecutive weeks. Compared with untreated db/db mice, treating db/db mice with RSV significantly decreased urine albumin excretion and the urine albumin to creatinine ratio, and attenuated renal histopathological injury. Furthermore, RSV treatment resulted in decreased expression levels of glucose-regulated protein of 78 kDa and C/EBP-homologous protein (two ER stress markers) and caspase12 in murine kidneys. RSV administration also inhibited the apoptosis of NRK-52E cells and activation of the ER stress signal transduction pathway induced by HG treatment in vitro. Collectively, the present results indicated that RSV protected renal tubular cells against HG-induced apoptosis in DN by suppressing ER stress.

SIRT1 is a key regulatory target for the treatment of the endoplasmic reticulum stress-related organ damage

Endoplasmic reticulum (ER) stress is an evolutionarily conserved adaptive response that contributes to deal with the misfolded or unfolded protein in the lumen of the ER and restore the ER homeostasis. However, excessive and prolonged ER stress can trigger the cell-death signaling pathway which causes cell death, usually in the form of apoptosis. It is generally accepted that inappropriate cellular apoptosis and a series of the subsequent inflammatory response and oxidative stress can cause disturbance of normal physiological functions and organ damage. A lot of evidence shows that the excessive activation of the ER stress contributes to the pathogenesis of many kinds of diseases and inhibiting the inappropriate stress is of great significance for maintaining the normal physiological function. In recent years, Sirtuin1 (SIRT1) has become a research hotspot on ER stress. As a master regulator of ER stress, increasing evidence suggests that SIRT1 plays a positive role in a variety of ER stress-induced organ damage via multiple mechanisms, including inhibiting cellular apoptosis and promoting autophagy. Furthermore, a lot of factors have shown effective regulation of SIRT1, which indicates the feasibility of treating SIRT1 as a target for the treatment of ER stress-related diseases. We summarize and reveal the molecular mechanisms underlying the protective effect of SIRT1 in multiple ER stress-mediated organ damage in this review. We also summed up the possible adjustment mechanism of SIRT1, which provides a theoretical basis for the treatment of ER stress-related diseases.

PDE5 inhibitor sildenafil attenuates cardiac microRNA 214 upregulation and pro-apoptotic signaling after chronic alcohol ingestion in mice

Abusive chronic alcohol consumption can cause metabolic and functional derangements in the heart and is a risk factor for development of non-ischemic cardiomyopathy. microRNA 214 (miR-214) is a molecular sensor of stress signals that negatively impacts cell survival. Considering cardioprotective and microRNA modulatory effects of sildenafil, a phosphodiesterase 5 (PDE5) inhibitor, we investigated the impact of chronic alcohol consumption on cardiac expression of miR-214 and its anti-apoptotic protein target, Bcl-2 and whether sildenafil attenuates such changes. Adult male FVB mice received unlimited access to either normal liquid diet (control), alcohol diet (35% daily calories intake), or alcohol + sildenafil (1 mg/kg/day, p.o.) for 14 weeks (n = 6-7/group). The alcohol-fed groups with or without sildenafil had increased total diet consumption and lower body weight as compared with controls. Echocardiography-assessed left ventricular function was unaltered by 14-week alcohol intake. Alcohol-fed group had 2.6-fold increase in miR-214 and significant decrease in Bcl-2 expression, along with enhanced phosphorylation of ERK1/2 and cleavage of PARP (marker of apoptotic DNA damage) in the heart. Co-ingestion with sildenafil blunted the alcohol-induced increase in miR-214, ERK1/2 phosphorylation, and maintained Bcl-2 and decreased PARP cleavage levels. In conclusion, chronic alcohol consumption triggers miR-214-mediated pro-apoptotic signaling in the heart, which was prevented by co-treatment with sildenafil. Thus, PDE5 inhibition may serve as a novel protective strategy against cardiac apoptosis due to chronic alcohol abuse.

Resveratrol restores intracellular transport in cystic fibrosis epithelial cells

We have demonstrated previously that intracellular transport is impaired in cystic fibrosis (CF) epithelial cells. This impairment is related to both growth and inflammatory regulation in CF cell and animal models. Understanding how transport in CF cells is regulated and identifying means to manipulate that regulation are key to identifying new therapies that can address key CF phenotypes. It was hypothesized that resveratrol could replicate these benefits since it interfaces with multiple pathways identified to affect microtubule regulation in CF. It was found that resveratrol treatment significantly restored intracellular transport as determined by monitoring both cholesterol distribution and the distribution of rab7-positive organelles in CF cells. This restoration of intracellular transport is due to correction of both microtubule formation rates and microtubule acetylation in cultured CF cell models and primary nasal epithelial cells. Mechanistically, the effect of resveratrol on microtubule regulation and intracellular transport was dependent on peroxisome proliferator-activated receptor-γ signaling and its ability to act as a pan-histone deacetylase (HDAC) inhibitor. Resveratrol represents a candidate compound with known anti-inflammatory properties that can restore both microtubule formation and acetylation in CF epithelial cells.

SIRT1 attenuates endoplasmic reticulum stress and apoptosis in rat models of COPD

The present study aimed to investigate the protective role of sirtuin 1 (SIRT1) and oxygen regulated protein 150 (ORP150) in a rat COPD model by inducing changes in ER stress and apoptosis. We separated 48 Sprague Dawley (SD) rats into four groups randomly: the control group, resveratrol group, COPD group and the resveratrol intervention group. Rats were challenged with cigarette smoke and lipopolysaccharide with resveratrol (a selective activator of SIRT1). The lung functions of the rats were measured and recorded. The expression levels of SIRT1 and ORP150 in lung tissues were examined by western blot and RTq PCR. The expression levels of the ER stress apoptosis-associated protein were determined .The apoptotic level of lung tissues was analyzed. The results suggest that SIRT1 attenuated apoptosis and ER stress in the lung tissues of rats with COPD. During this process, a positive correlation was identified between SIRT1 and ORP150.

Acid-induced autophagy protects human gastric cancer cells from apoptosis by activating Erk1/2 pathway

Background

Acidic microenvironments exist widely in tumors. However, the specific mechanism of cancer cell survival under an acidic microenvironment remains unknown. This study aims to investigate whether acid can induce autophagy and examine the mechanism of autophagy in gastric cancer cells.

Methods

Human gastric adenocarcinoma (AGS) cells were cultured in media with different pH values in vitro and then subjected to autophagy detection under different conditions. To determine the effect of an acidic microenvironment on autophagy, we employed real-time quantitative polymerase chain reaction (PCR), Western blot, mRFP-GFP-LC3 immunofluorescence, and transmission electron microscopy (TEM) to detect the expression of various autophagy indicators. We also performed cell counting kit 8 (CCK8) and cell invasion and migration assays to examine cell viability and invasion, respectively.

Results

We found that the protein expression of autophagy markers such as LC3II/I and Beclin1 was higher in AGS cells treated with an acidic microenvironment than in control cells. The protein expression level of P62 was obviously decreased in acid-treated cells compared to that in control cells. Furthermore, the expression of Erk1/2 pathway markers, including p-Erk1/2, was also increased in response to acidic pH. Dense LC3 puncta were observed in cells cultured under acidic conditions, whereas untreated cells exhibited diffuse and weak LC3 puncta; an increased autophagy flux could also be observed. The presence of autophagosomes was observed by TEM in AGS cells subjected to low pH. Additionally, autophagy was inhibited by the autophagy inhibitor Bafilomycin A1 (Baf) and apoptosis was obviously increased. Moreover, cells exposed to an acidic microenvironment displayed facilitated growth compared with that in control cells.

Conclusions

Taken together, these results indicate that the acidic microenvironment promotes AGS cell growth by upregulating autophagy through the Erk1/2 pathway, which acts as a survival adaptation.

Pathogenesis, Early Diagnosis, and Therapeutic Management of Alcoholic Liver Disease

Alcoholic liver disease (ALD) refers to the damages to the liver and its functions due to alcohol overconsumption. It consists of fatty liver/steatosis, alcoholic hepatitis, steatohepatitis, chronic hepatitis with liver fibrosis or cirrhosis, and hepatocellular carcinoma. However, the mechanisms behind the pathogenesis of alcoholic liver disease are extremely complicated due to the involvement of immune cells, adipose tissues, and genetic diversity. Clinically, the diagnosis of ALD is not yet well developed. Therefore, the number of patients in advanced stages has increased due to the failure of proper early detection and treatment. At present, abstinence and nutritional therapy remain the conventional therapeutic interventions for ALD. Moreover, the therapies which target the TNF receptor superfamily, hormones, antioxidant signals, and MicroRNAs are used as treatments for ALD. In particular, mesenchymal stem cells (MSCs) are gaining attention as a potential therapeutic target of ALD. Therefore, in this review, we have summarized the current understandings of the pathogenesis and diagnosis of ALD. Moreover, we also discuss the various existing treatment strategies while focusing on promising therapeutic approaches for ALD.

Advances in the treatment of severe alcoholic hepatitis

Severe alcoholic hepatitis (SAH) is a costly and worldwide public health issue with high morbidity and mortality. Specific effective treatments for SAH have yet to be established. The aim of the present article is to review the current knowledge of the pathogenesis, assessment and treatment options in patients with SAH. To date, alcohol abstinence and enteral nutrition are the recommended first-line treatments. Although corticosteroids remain the preferred therapy for certain patients with a modified Maddrey discriminant function level greater than 54, they only improve short-term survival rates. New research focuses on liver inflammation, liver regeneration, the gut-liver axis, human induced pluripotent stem cells and extracorporeal albumin dialysis. Liver transplantation is considered the last medical option for patients with SAH who are nonresponsive to other medical treatments.

Effects of resveratrol pretreatment on endoplasmic reticulum stress and cognitive function after surgery in aged mice

Background

Postoperative cognitive dysfunction (POCD) seriously reduces quality of life and is associated with increased morbidity and mortality. The causes and neuropathogenesis of POCD remain largely unknown. Resveratrol, a sirtuin 1 (Sirt1) activator, is a polyphenol compound found in red wine that has protective functions in neuropathology paradigms. Endoplasmic reticulum stress (ERS) is a primary cellular response that activates the unfolded protein response (UPR). ERS and UPR mediate molecular and biochemical mechanisms related to neurodegeneration; however, the roles of ERS and Sirt1 in POCD remain unclear. The properties of resveratrol might be useful in the setting of POCD.

Methods

In the present study, we investigated learning and memory function and ERS pathways in aged mice after surgery under local anesthesia, and we evaluated the effects of resveratrol pretreatment.

Results

We found that resveratrol attenuated postoperative learning and memory impairment in aged mice postoperatively but did not alter locomotor activity. Resveratrol significantly decreased postoperative expression of ERS pathway UPR-related proteins and inflammatory mediators including nuclear factor-κB (NF-κB) in the hippocampus. This was accompanied by higher Sirt1 protein expression levels. Pretreatment with resveratrol did not affect the number of hippocampal neurons in aged mice after surgery.

Conclusion

Overall, resveratrol pretreatment attenuated short-term learning and memory impairment and the ERS pathway UPR in aged mice after surgery under local anesthesia.

Novel Akt activator SC-79 is a potential treatment for alcohol-induced osteonecrosis of the femoral head

Alcohol is a leading risk factor for osteonecrosis of the femoral head (ONFH). We explored the molecular mechanisms underlying alcohol-induced ONFH and investigated the protective effect of the novel Akt activator SC-79 against this disease. We found that ethanol inhibited expression of the osteogenic genes RUNX2 and OCN, downregulated osteogenic differentiation, impaired the recruitment of Akt to the plasma membrane, and suppressed Akt phosphorylation at Ser473, thereby inhibiting the Akt/GSK3β/β-catenin signaling pathway in bone mesenchymal stem cells. To assess SC-79′s ability to counteract the inhibitory effect of ethanol on Akt-Ser73 phosphorylation, we performed micro-computerized tomography and immunofluorescent staining of osteopontin, osteocalcin and collagen type 1 in a rat model of alcohol-induced ONFH. We found that SC-79 injections inhibited alcohol-induced osteonecrosis. These results show that alcohol-induced ONFH is associated with suppression of p-Akt-Ser473 in the Akt/GSK3β/β-catenin signaling pathway in bone mesenchymal stem cells. We propose that SC-79 treatment to rescue Akt activation could be tested in the clinic as a potential therapeutic approach to preventing the development of alcohol-induced ONFH.

NOX4/ROS mediate ethanol‑induced apoptosis via MAPK signal pathway in L‑02 cells

The aim of the present study was to assess the molecular mechanism of ethanol‑induced oxidative stress‑mediated apoptosis in L‑02 liver cells in order to elucidate novel pathways associated with alcoholic liver disease. L‑02 cells were treated with 400 mM ethanol with or without inhibitors. The cell viability was measured by an MTT assay. Cell apoptosis was assessed by flow cytometry and a single‑stranded DNA (ssDNA) assay. Intracellular reactive oxygen species (ROS) production of L‑02 cells was determined using the 2',7'‑dichlorofluorescein‑diacetate dye. The protein expression of c‑Jun N‑terminal kinase (JNK), phosphorylated (p)‑JNK, P38, p‑P38, NADPH oxidase (NOX)1, NOX4, p22phox, B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein were measured by western blot analysis. The mRNA expression of NOX1, NOX4 and p22phox was measured by reverse transcription polymerase chain reaction analysis. The results indicated that after treatment with various concentrations of ethanol for the indicated durations, L‑02 cells were displayed a significant decrease in cell viability in a dose‑and time‑dependent manner. Ethanol‑induced apoptosis and cell death of L‑02 cells was accompanied by the generation of ROS, elevated expression of NOX, as well as phosphorylation of JNK and P‑38. In addition, increased expression of Bcl‑2 was induced by 400 mM ethanol. Furthermore, treatment with NOX inhibitor attenuated the ethanol‑induced a decrease in cell viability, and an increase in apoptosis and Bcl‑2 expression. In conclusion, ethanol induced apoptosis in the L‑02 hepatocyte cell line via generation of ROS and elevated expression of NOX4. This indicated that activation of JNK and p38 in the mitogen‑activated protein kinase pathway promotes apoptosis in L‑02 cells.

Alcohol and Hepatocellular Carcinoma: Adding Fuel to the Flame

Primary tumors of the liver represent the fifth most common type of cancer in the world and the third leading cause of cancer-related death. Case-control studies from different countries report that chronic ethanol consumption is associated with an approximately 2-fold increased odds ratio for hepatocellular carcinoma (HCC). Despite the substantial epidemiologic data in humans demonstrating that chronic alcohol consumption is a major risk factor for HCC development, the pathways causing alcohol-induced liver cancer are poorly understood. In this overview, we summarize the epidemiological evidence for the association between alcohol and liver cancer, review the genetic, oncogenic, and epigenetic factors that drive HCC development synergistically with ethanol intake and discuss the essential molecular and metabolic pathways involved in alcohol-induced liver tumorigenesis.

Influence of resveratrol on endoplasmic reticulum stress and expression of adipokines in adipose tissues/adipocytes induced by high-calorie diet or palmitic acid

PURPOSE

This study aimed to determine whether resveratrol treatment alleviates endoplasmic reticulum stress and changes the expression of adipokines in adipose tissues and cells.

METHODS

8-week-old male C57BL/6 mice were fed a high-calorie diet (HCD group) or high-calorie diet supplemented with resveratrol (high-calorie diet  + resveratrol group) for 3 months. Insulin resistance, serum lipids and proinflammatory indices, the size and inflammatory cell infiltration in subcutaneous and visceral adipose tissues were analyzed. The gene expressions of endoplasmic reticulum stress, adipokines, and inflammatory cytokines were determined. The induced mature 3T3-L1 cells were pretreated with resveratrol and then palmitic acid, and the gene expressions of endoplasmic reticulum stress, adipokines, and inflammatory cytokines were determined.

RESULTS

Subcutaneous and visceral adipose tissues in the high-calorie diet-fed mice exhibited adipocyte hypertrophy, inflammatory activation, and endoplasmic reticulum stress. Resveratrol alleviated high-calorie diet-induced insulin resistance and endoplasmic reticulum stress, increased expression of SIRT1, and reversed expression of adipokines in varying degrees in both subcutaneous and visceral adipose tissues. The effects of resveratrol on palmitic acid-treated adipocytes were similar to those shown in the tissues.

CONCLUSIONS

Resveratrol treatment obviously reversed adipocyte hypertrophy and insulin resistance by attenuating endoplasmic reticulum stress and inflammation, thus increasing the expression of SIRT1 and inverting the expression of adipokines in vivo and in vitro.

Cyanidin 3-O-β-Glucoside Ameliorates Ethanol-Induced Acute Liver Injury by Attenuating Oxidative Stress and Apoptosis: The Role of SIRT1/FOXO1 Signaling

BACKGROUND

The aim of this study was to examine the effects of Cyanidin 3-O-β-glucoside (C3G) on ethanol (EtOH)-induced acute liver injury in mice as well as in cultured hepatic cells exposed to EtOH, with a focus on the involvement of Silent Mating Type Information Regulation 2 Homolog 1 (SIRT1)/Forkhead fox-O-1 (FOXO1) signaling pathway, and to explore the underlying molecular mechanisms.

METHODS

C57BL/6 adolescent male mice were given EtOH via intraperitoneal injection for 2 consecutive days, and the changes in the livers were detected via hematoxylin-eosin staining. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured by biochemical methods. Protein expression of SIRT1, FOXO1, acetylated FOXO1 (ac-FOXO1), GRP78, p-eukaryotic initiation factor-2 (eIF2α), and apoptosis (p-JNK, p-c-Jun, and Bax) parameters was determined by Western blot. Reactive oxygen species (ROS) was detected by flow cytometry. Human hepatocytes Chang cell line was used to assay cell apoptosis by Annexin V and propidium iodide. In addition, mRNA levels of SIRT1, tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and monocyte chemoattractant protein 1 in liver tissues were detected by real-time polymerase chain reaction.

RESULTS

This study demonstrated that C3G (10 mg/kg) administration diminished EtOH-induced acute liver injury compared to control group, as evidenced by the significant decreases in ALT and AST levels. Pretreatment with C3G exerted anti-inflammatory effects as indicated by the decreased TNF-α and IL-6 levels, as well as decreased inflammatory foci and ballooning cells in liver tissue. The lessened hepatic injury was associated with enhanced SIRT1 protein expression and activity by C3G in vitro and in vivo. C3G treatment also provoked significant attenuation of endoplasmic reticulum stress parameters (GRP78, p-eIF2α), which was consistent with reduced levels of both p-c-Jun and Bax. Interestingly, EX527 inhibitor did not affect the protective function of C3G on alcohol-induced cell apoptosis. Moreover, alcohol exposure increased ROS level and decreased ac-FOXO1, while C3G intervention reversed this abnormality, and this may be related to SIRT1 activity by C3G.

CONCLUSIONS

Anthocyanin C3G has significant potency in antioxidant, anti-inflammatory, and anti-apoptotic effects on hepatocytes exposed to EtOH by modulating the SIRT1/FOXO1 signaling pathway. Our findings illustrate a novel and definitive therapeutic action of C3G and represent an economically feasible therapeutic intervention to treat alcoholic liver disease.

Mechanism of Hepatocyte Apoptosis

Hepatocyte apoptosis plays important roles in both the removal of external microorganisms and the occurrence and development of liver diseases. Different conditions, such as virus infection, fatty liver disease, hepatic ischemia reperfusion, and drug-induced liver injury, are accompanied by hepatocyte apoptosis. This review summarizes recent research on the mechanism of hepatocyte apoptosis involving the classical extrinsic and intrinsic apoptotic pathways, endoplasmic reticulum stress, and oxidative stress-induced apoptosis. We emphasized the major causes of apoptosis according to the characteristics of different liver diseases. Several concerns regarding future research and clinical application are also raised.

Dietary supplementation in patients with alcoholic liver disease: a review on current evidence

BACKGROUND

Alcoholic liver disease (ALD) is one of the main causes of liver disease worldwide. Although the pathogenesis of ALD has not yet been well elucidated, the oxidative metabolites of ethanol such as acetaldehyde and reactive oxygen species play a pivotal role in the clinical and pathological spectrum of the disease. This review summarizes the existing evidences on dietary supplements considered to have antioxidant, and/or anti-inflammatory properties, and their role in the management of ALD and the proposed mechanisms.

DATA SOURCES

The present study reviewed all studies published in PubMed, ScienceDirect and Scopus, from 1959 to 2015, indicating the role of different dietary supplementation in attenuation of many pathophysiological processes involved in development and progression of ALD. Full-texts of citations were used except for those that were published in languages other than English.

RESULTS

Significant progress has been made to understand the key events and molecular players for the onset and progression of ALD from both experimental and clinical studies; however, there is no successful treatment currently available. The present review discussed the role of a variety of dietary supplements (e.g. vitamin A, carotenoids, vitamins B3, C and E, in addition to antioxidants and anti-inflammatory agents) in treating ALD. It has been shown that supplementation with some carotenoids, vitamin B3, vitamin C, silymarin, curcumin, probiotics, zinc, S-adenosylmethionine and garlic may have potential beneficial effects in animal models of ALD; however, the number of clinical studies is very limited. In addition, supplementation should be accompanied with alcohol cessation.

CONCLUSIONS

Since oxidative stress and inflammation are involved in the pathogenesis of ALD, dietary supplements that can modulate these pathologies could be useful in the treatment of ALD. In addition to alcohol cessation, these supplements have shown beneficial effects on animal models of ALD. Clinical trials are needed to validate the beneficiary role of these supplements in patients with ALD.

Andrographolide-induced apoptosis in human renal tubular epithelial cells: Roles of endoplasmic reticulum stress and inflammatory response

Andrographolide sodium bisulfate as a kind of soluble derivative of andrographolide (AD), is obviously known to be nephrotoxicity, but AD has not been reported clearly. Our study aimed to investigate the induction of apoptosis in human renal tubular epithelial (HK-2) cells by AD and its possible mechanism. Our results demonstrated that AD (0-250μmol/L) inhibited Hk-2 cells proliferation in a dose- and time-dependent manner and induced apoptosis, accompanied by decreased of superoxide dismutase (SOD) activity and increased of malondialdehvde (MDA) content. Simultaneously, AD regulated the expression of endoplasmic reticulum (ER) molecular chaperone glucose-regulated protein 78 (GRP78/Bip) protein, elevated the expressions of C/EBP homologous protein (CHOP) and Caspase-4, indicating activation of ER stress signaling, and induced the alterative expression of kidney injury molecule-1 (KIM-1), tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) proteins. It provided evidence that ER stress and inflammation would be significant mechanisms responsible for AD-induced apoptosis in addition to oxidative stress.

Methyl-deficient diet promotes colitis and SIRT1-mediated endoplasmic reticulum stress

BACKGROUND

Methyl donor deficiency (MDD) aggravates experimental colitis in rats and increases endoplasmic reticulum (ER) stress through decreased sirtuin 1 (SIRT1) in neuronal cells and myocardium. ER stress plays a key role in IBD pathogenesis.

AIM

We investigated whether the influence of MDD on colitis resulted from an ER stress response triggered by decreased SIRT1 expression.

DESIGN

The unfolded protein response (UPR), chaperones proteins, heat shock factor protein 1 (HSF1) and SIRT1 were examined in rats with MDD and dextran sulfate sodium (DSS)-induced colitis in a Caco-2 cell model with stable expression of transcobalamin-oleosin (TO) chimera, which impairs cellular availability of vitamin B12, and in IBD. The effects of SIRT1 activation were studied both in vitro and in vivo.

RESULTS

MDD aggravated DSS-induced colitis clinically, endoscopically and histologically. MDD activated ER stress pathways, with increased phosphorylate-PKR-like ER kinase, P-eiF-2α, P-IRE-1α, activating transcription factor (ATF)6, XBP1-S protein and ATF4 mRNA expression levels in rats. This was accompanied by reduced SIRT1 expression level and greater acetylation of HSF1, in relation with a dramatic decrease of chaperones (binding immunoglobulin protein (BIP), heat shock protein (HSP)27 and HSP90). Adding either vitamin B12, S-adenosylmethionine or an SIRT1 activator (SRT1720) reduced the UPR in vitro. In rats, SIRT1 activation by SRT1720 prevented colitis by reducing HSF1 acetylation and increasing expression of BIP, HSP27 and HSP90. Immunohistochemistry showed impaired expression of SIRT1 in the colonic epithelium of patients with IBD.

CONCLUSIONS

SIRT1 is a master regulator of ER stress and severity of experimental colitis in case of MDD. It could deserve further interest as a therapeutic target of IBD.

Regulation of eIF2α expression and renal interstitial fibrosis by resveratrol in rat renal tissue after unilateral ureteral obstruction

PURPOSE

This study was performed to assess the effect of resveratrol on the expression of eukaryotic initiation factor 2α (eIF2α) and activating transcription factor 4 (ATF4) in renal tissues of rats with unilateral ureteral obstruction (UUO).

METHODS

Using UUO animal model, after 14 days of surgery, pathological changes were detected by HE staining, renal tubular damage index, renal interstitial collagen deposition area were evaluated by Masson staining, in situ cell apoptosis in renal tissue was analyzed by TUNEL assay, and protein expression of eIF2α and ATF4 in renal tissue was analyzed using western blot detection.

RESULTS

After comparison of the treatment groups with model group, we observed that the degree of renal tubular damage, relative area of renal interstitial collagen and eIF2α, ATF4 protein expression were also significantly reduced (p<0.05, p  <0.01) in the high-dose resveratrol group.

CONCLUSION

Resveratrol can reduce the level of eIF2α protein expression, which further reduces the ATF4 levels.

Pterostilbene exerts an anti-inflammatory effect via regulating endoplasmic reticulum stress in endothelial cells

Pterostilbene (PT), an analog of resveratrol, exerts a potent anti-inflammatory effect. However, the protective effects of PT against inflammation in endothelial cells have not been elucidated. Previous studies have confirmed that endoplasmic reticulum stress (ERS) plays an important role in regulating the pathological process of endothelial cell inflammation. In this study, we explored the effect of PT on the tumor necrosis factor-α (TNF-α)-induced inflammatory response in human umbilical vein endothelial cells (HUVECs) and elaborated the role of ERS in this process. TNF-α treatment significantly upregulated the levels of inflammation-related molecules in cell culture media, increased the adhesion of monocytes to HUVECs, and enhanced the expression of the MMP9 and ICAM proteins in HUVECs. Additionally, TNF-α potently increased ERS-related protein levels, such as GRP78 and p-eIF2α. However, PT treatment reversed the increased production of inflammatory cytokines and the adhesion of monocytes to HUVECs, as well as reduced the TNF-α-induced effects exerted by ERS-related molecules. Furthermore, thapsigargin (THA), an ERS inducer, attenuated the protective effect of PT against TNF-α-induced inflammation and ERS in HUVECs. Additionally, the downregulation of ERS signaling using siRNA targeting eIF2α and IRE1 not only inhibited ERS-related molecules but also simulated the therapeutic effects of PT on TNF-α-induced inflammation. In summary, PT treatment potently attenuates inflammation in vascular endothelial cells, which at least partly depends on the reduction of ERS.

Resveratrol prevents doxorubicin-induced cardiotoxicity in H9c2 cells through the inhibition of endoplasmic reticulum stress and the activation of the Sirt1 pathway

Treatment with doxorubicin (DOX) is one of the major causes of chemotherapy-induced cardiotoxicity and is therefore, the principal limiting factor in the effectiveness of chemotherapy for cancer patients. DOX‑induced heart failure is thought to result from endoplasmic reticulum (ER) stress and cardiomyocyte apoptosis. Resveratrol (RV), a polyphenol antioxidant found in red wine, has been shown to play a cardioprotective role. The aim of the present study was to examine the effects of RV on DOX‑induced cardiotoxicity in H9c2 cells. We hypothesized that RV would protect H9c2 cells against DOX‑induced ER stress and subsequent cell death through the activation of the Sirt1 pathway. Our results demonstrated that the decrease observed in the viability of the H9c2 cells following exposure to DOX was accompanied by a significant increase in the expression of the ER stress‑related proteins, glucose‑regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP). However, we found that RV downregulated the expression of ER stress marker protein in the presence of DOX and restored the viability of the H9c2 cells. Exposure to RV or DOX alone only slightly increased the protein expression of Sirt1, whereas a significant increase in Sirt1 protein levels was observed in the cells treated with both RV and DOX. The Sirt1 inhibitor, nicotinamide (NIC), partially neutralized the effects of RV on the expression of Sirt1 in the DOX‑treated cells and completely abolished the effects of RV on the expression of GRP78 and CHOP. The findings of our study suggest that RV protects H9c2 cells against DOX‑induced ER stress through ER stabilization, and more specifically through the activation of the Sirt1 pathway, thereby leading to cardiac cell survival.

Translational Implications of the Alcohol-Metabolizing Enzymes, Including Cytochrome P450-2E1, in Alcoholic and Nonalcoholic Liver Disease

Fat accumulation (hepatic steatosis) in alcoholic and nonalcoholic fatty liver disease is a potentially pathologic condition which can progress to steatohepatitis (inflammation), fibrosis, cirrhosis, and carcinogenesis. Many clinically used drugs or some alternative medicine compounds are also known to cause drug-induced liver injury, which can further lead to fulminant liver failure and acute deaths in extreme cases. During liver disease process, certain cytochromes P450 such as the ethanol-inducible cytochrome P450-2E1 (CYP2E1) and CYP4A isozymes can be induced and/or activated by alcohol and/or high-fat diets and pathophysiological conditions such as fasting, obesity, and diabetes. Activation of these P450 isozymes, involved in the metabolism of ethanol, fatty acids, and various drugs, can produce reactive oxygen/nitrogen species directly and/or indirectly, contributing to oxidative modifications of DNA/RNA, proteins and lipids. In addition, aldehyde dehydrogenases including the mitochondrial low Km aldehyde dehydrogenase-2 (ALDH2), responsible for the metabolism of acetaldehyde and lipid aldehydes, can be inactivated by various hepatotoxic agents. These highly reactive acetaldehyde and lipid peroxides, accumulated due to ALDH2 suppression, can interact with cellular macromolecules DNA/RNA, lipids, and proteins, leading to suppression of their normal function, contributing to DNA mutations, endoplasmic reticulum stress, mitochondrial dysfunction, steatosis, and cell death. In this chapter, we specifically review the roles of the alcohol-metabolizing enzymes including the alcohol dehydrogenase, ALDH2, CYP2E1, and other enzymes in promoting liver disease. We also discuss translational research opportunities with natural and/or synthetic antioxidants, which can prevent or delay the onset of inflammation and liver disease.

Resveratrol attenuates microvascular inflammation in sepsis via SIRT-1-Induced modulation of adhesion molecules in ob/ob mice

OBJECTIVE

Obesity, a sirtuin-1 (SIRT-1) -deficient state, increases morbidity and resource utilization in critically ill patients. SIRT-1 deficiency increases microvascular inflammation and mortality in early sepsis. The objective of the study was to study the effect of resveratrol (RSV), a SIRT-1 activator, on microvascular inflammation in obese septic mice.

METHODS

ob/ob and C57Bl/6 (WT) mice were pretreated with RSV versus dimethyl sulfoxide (DMSO) (vehicle) prior to cecal ligation and puncture (sepsis). We studied (1) leukocyte/platelet adhesion, (2) E-selectin, ICAM-1, and SIRT-1 expression in small intestine, and (3) 7-day survival. A group of RSV-treated mice received SIRT-1 inhibitor (EX-527) with sepsis induction, and leukocyte/platelet adhesion and E-selectin/ICAM-1 expression were studied. We treated endothelial (HUVEC) cells with RSV to study E-selectin/ICAM-1 and p65-acetylation (AC-p65) in response to lipopolysaccharide (LPS).

RESULTS

RSV treatment decreased leukocyte/platelet adhesion and E-selectin/ICAM-1 expression with increased SIRT-1 expression in septic ob/ob and WT mice, decreased E-selectin/ICAM-1 expression via increased SIRT-1 expression, and decreased AC-p65 expression in HUVEC. EX-527 abolished RSV-induced attenuation of microvascular inflammation in ob/ob septic mice. Finally, ob/ob mice in the sepsis+RSV group had significantly increased 7-day survival versus the sepsis+vehicle group.

CONCLUSIONS

RSV increases SIRT-1 expression in ob/ob septic mice to reduce microvascular inflammation and improves survival.

SIRT1 suppresses cardiomyocyte apoptosis in diabetic cardiomyopathy: An insight into endoplasmic reticulum stress response mechanism

BACKGROUND

Endoplasmic reticulum (ER) stress-dependent apoptosis had been shown to occur in the hearts of people with diabetes, although the exact mechanisms are unclear. Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide NAD(+)-dependent deacetylase, is known to play a role in diabetes-related complications as well as ER-stress. Therefore, we investigated the relationship between Sirtuin 1 (SIRT1) and ER stress-induced apoptosis in H9C2 cardiomyocyte.

METHODS

Diabetic rats were established by a single intraperitoneal injection of streptozotocin (STZ; 50mg/kg) with high-fat diet. For in vitro analysis, rat derived H9C2 cardiomyocytes were cultured. Cardiac function was assessed by Doppler, and SIRT1 as well as ER stress related protein expressions were measured by immunohistochemistry and western blotting. Cultured cells were exposed to advanced glycation end products (AGEs) (400μg/mL) for inducing ER stress and apoptosis. Cell apoptosis were detected by flow cytometry.

RESULTS

In vivo, ER stress was enhanced in the cardiomyocytes of diabetic rats without any treatments. A SIRT1 activator, resveratrol, could significantly restore cardiac function, reduce cardiomyocyte apoptosis, and ameliorate ER stress. In vitro, we showed that apoptosis and ER stress increased after AGE stimulation when SIRT1 expression was downregulated by short interfering RNA (siRNA) (p<0.05). However, resveratrol (10μM) restored SIRT1 levels in cardiomyocytes and markedly reduced ER stress-mediated apoptosis.

CONCLUSION

SIRT1 may attenuate ER stress-induced cardiomyocyte apoptosis via PERK/eIF2α, ATF6/CHOP, and IRE1α/JNK-mediated pathways. This study may provide insights into a novel underlying mechanism and a strategy for treating diabetic cardiomyopathy.

Protein S exacerbates alcoholic hepatitis by stimulating liver natural killer T cells

BACKGROUND

Alcohol consumption is a major cause of liver injury but the mechanisms are not completely understood. Protein S (PS) is an anticoagulant glycoprotein with multiple functions. The role of PS in liver injury is unknown.

OBJECTIVES

This study investigated the role of PS in acute alcoholic hepatitis.

METHODS

A mouse overexpressing human PS (hPS-TG) was generated in which acute hepatitis was induced by intraperitoneal injection of ethanol.

RESULTS

The levels of serum liver enzymes and liver tissue inflammatory cytokines and the degree of hepatic steatosis were significantly increased in hPS-TG mice treated with ethanol compared with ethanol-treated wild type (WT) mice. Cell expansion, activation and inhibition of apoptosis were significantly augmented in natural killer T (NKT) cells from hPS-TG mice compared with WT mice. Liver mononuclear cells from hPS-TG mice express higher levels of inflammatory cytokines than those from WT mice after stimulation with a specific stimulant of NKT cells in vitro. In a co-culture system of hepatocytes and NKT cells, the effects of PS on ethanol-mediated cell injury were suppressed by a CD1d neutralizing antibody. Alcoholic liver injury was significantly improved in mice pre-treated with PS siRNA and anti-protein S antibody compared with control mice. Patients with alcoholic hepatitis showed significantly increased plasma PS levels and enhanced liver expression of PS and CD1d compared with controls.

CONCLUSIONS

The results of this study suggest that PS exacerbates acute alcoholic hepatitis by inhibiting apoptosis of activated NKT cells.

Protective effects of resveratrol against alcohol-induced oxidative stress and apoptosis in human SH-SY5Y cells

AIM: To assess the effects of resveratrol as an antioxidant against alcohol-induced oxidative stress and apoptosis in SH-SY5Y cells and explore the underlying mechanisms.

METHODS: SH-SY5Y cells were pretreated with resveratrol for 24 h before treatment with alcohol to induce oxidative stress and apoptosis. MTT assay was then performed to detect the viability of SH-SY5Y cells in both resveratrol-treated and control groups. ELISA was performed to detect the presence of superoxide dismutase (SOD) and the level of total intracellular reactive oxygen species (ROS). Flow cytometry was used to detect cell apoptosis. RT-PCR was performed to detect the expression levels of SOD₁, SOD₂, catalase, PARP and Caspase 3, which are key genes involved in anti-oxidation and apoptosis pathways.

RESULTS: MTT assay showed that in comparison with control cells (non-treated with resveratrol), toxicity of resveratrol (25, 50, 100 μmol/L) towards SH-SY5Y cells was below 20%. Treatment with 300 mmol/L alcohol without pre-treatment with resveratrol resulted in death of around 57% cells. Resveratrol at concentrations from 25-100 μmol/L played an antagonistic role against cytotoxicity of 300 mmol/L alcohol to SH-SY5Ycells. ELISA results showed that SOD activity was significantly higher in cells treated with 100 μmol/L resveratrol (0.559 ± 0.021) than in non-treated cells (0.296 ± 0.023). After alcohol induction, non-resveratrol-treated cells showed a higher ROS level (16163.89 ± 624.67) compared to cells treated with 25, 50, and 100 μmol/L resveratrol (29302.79.26 ± 1208.38; 25528.34 ± 1126.63; 20219.78 ± 1622.35). Flow cytometry showed that the percentage of apoptotic cells in alcohol treated cells were higher than those in other groups. RT-PCR results showed that compared to cells treated with 300 mmol/L alcohol, resveratrol increased the expression of SOD₁ (0.623 ± 0.033; 0.686 ± 0.022; 0.853 ± 0.014), SOD₂ (1.19 ± 0.123; 0,928 ± 0.0121; 1.09 ± 0.0101), catalase (1.828 ± 0.067; 2.018 ± 0.079; 2.196 ± 0.081), PARP (2.828 ± 0.161; 3.018 ± 0.208; 4.196 ± 0.190) and Caspase3 (5.828 ± 0.367; 5.318 ± 0.279; 4.196 ± 0.200).

CONCLUSION: Our findings show the neuroprotective of resveratrol against alcohol-induced oxidative stress and apoptosis in SH-SY5Y cells.

Resveratrol exerts an anti-apoptotic effect on human bronchial epithelial cells undergoing cigarette smoke exposure

Cigarette smoke can cause endoplasmic reticulum stress and induce apoptosis, both of which are important pathogenic factors contributing to chronic obstructive pulmonary disease. The aim of the present study was to produce a cigarette smoke extract (CSE)-induced apoptosis human bronchial epithelial cell (HBEpC) model, to investigate the protective effects of resveratrol (RES). The role of oxygen-regulated protein 150 (ORP150) in the RES-induced activation of Sirtuin 1 (SIRT1) was additionally studied. Cultured HBEpCs were initially treated with CSE to induce apoptosis, followed by an incubation either with or without RES. Numerous techniques were used to evaluate the outcomes of the present study, including cell counting kit-8 assay, quantitative polymerase chain reaction, western blotting, Hoechst 33342 staining and AnnexinV-PI flow cytometry apoptosis analyses, and gene knockdown. It was identified that 24 h 2% CSE incubation induced apoptosis in HBEpC, accompanied by an overexpression of the apoptosis molecular markers CCAAT-enhancer-binding protein homologous protein, caspase 4 and caspase 3. Pre-treatment of the cells with RES markedly alleviated the severity of apoptosis, as confirmed by apoptosis analyses and the expression levels of the apoptosis molecular markers. SIRT1 was shown to be overexpressed following RES treatment. However, following the gene knockdown of ORP150, the anti-apoptotic effects of RES were significantly attenuated. The results of the present study demonstrate that RES may have a protective effect against CSE-induced apoptosis, and a molecular pathway involving SIRT1 and ORP150 may be associated with the anti-apoptotic functions of RES in HBEpC.

Biological significance and therapeutic implication of resveratrol-inhibited Wnt, Notch and STAT3 signaling in cervical cancer cells

Cervical cancers/CCs are one of the commonest malignancies and the second leading cause of cancer-related death in women. Resveratrol inhibits CC cell growth but its molecular target(s) remains unclear. Since the signaling pathways mediated by STAT3, Notch1 and Wnt2 play beneficial roles in CC formation and progression, the effects of resveratrol on them in cervical adenocarcinoma (HeLa) and squamous cell carcinoma (SiHa) cells were analyzed. The biological significances of the above signaling for HeLa and SiHa cells were evaluated by treating the cells with STAT3, Wnt or Notch selective inhibitors. The frequencies of STAT3, Notch and Wnt activations in 68 cases of CC specimens and 38 non-cancerous cervical epithelia were examined by tissue microarray-based immunohistochemical staining. The results revealed that HeLa and SiHa cells treated by 100μM resveratrol showed extensive apoptosis, accompanied with suppression of STAT3, Notch and Wnt activations. Growth inhibition and apoptosis were found in HeLa and SiHa populations treated by AG490, a STAT3/JAK3 inhibitor but not the ones treated by Notch inhibitor L-685,458 or by Wnt inhibitor XAV-939. Immunohistochemical staining performed on the tissue microarrays showed that the frequencies of Notch1, Notch2, Hes1, Wnt2, Wnt5a and p-STAT3 detection as well as β-catenin nuclear translocation in CC samples were significantly higher than that of noncancerous group (p<0.01), while the expression rate of PIAS3 was remarkably low in cancer samples (p<0.01). Our results thus demonstrate that STAT3, Wnt and Notch signaling are frequently co-activated in human CC cells and specimens and resveratrol can concurrently inhibit those signaling activations and meanwhile lead cervical squamous cell carcinoma and adenocarcinoma cells to growth arrest and apoptosis. STAT3 signaling is more critical for CC cells and is the major target of resveratrol because selective inhibition of STAT3 rather than Wnt or Notch activation commits SiHa and HeLa cells to apoptosis.