TRP14 is the rate-limiting enzyme for intracellular cystine reduction and regulates proteome cysteinylation.

It has remained unknown how cells reduce cystine taken up from the extracellular space, which is a required step for further utilization of cysteine in key processes such as protein or glutathione synthesis. Here, we show that the thioredoxin-related protein of 14 kDa (TRP14, encoded by TXNDC17) is the rate-limiting enzyme for intracellular cystine reduction. When TRP14 is genetically knocked out, cysteine synthesis through the transsulfuration pathway becomes the major source of cysteine in human cells, and knockout of both pathways becomes lethal in C. elegans subjected to proteotoxic stress. TRP14 can also reduce cysteinyl moieties on proteins, rescuing their activities as here shown with cysteinylated peroxiredoxin 2. Txndc17 knockout mice were, surprisingly, protected in an acute pancreatitis model, concomitant with activation of Nrf2-driven antioxidant pathways and upregulation of transsulfuration. We conclude that TRP14 is the evolutionarily conserved enzyme principally responsible for intracellular cystine reduction in C. elegans, mice, and humans.

Health position paper and redox perspectives - Disease burden by transportation noise.

Transportation noise is a ubiquitous urban exposure. In 2018, the World Health Organization concluded that chronic exposure to road traffic noise is a risk factor for ischemic heart disease. In contrast, they concluded that the quality of evidence for a link to other diseases was very low to moderate. Since then, several studies on the impact of noise on various diseases have been published. Also, studies investigating the mechanistic pathways underlying noise-induced health effects are emerging. We review the current evidence regarding effects of noise on health and the related disease-mechanisms. Several high-quality cohort studies consistently found road traffic noise to be associated with a higher risk of ischemic heart disease, heart failure, diabetes, and all-cause mortality. Furthermore, recent studies have indicated that road traffic and railway noise may increase the risk of diseases not commonly investigated in an environmental noise context, including breast cancer, dementia, and tinnitus. The harmful effects of noise are related to activation of a physiological stress response and nighttime sleep disturbance. Oxidative stress and inflammation downstream of stress hormone signaling and dysregulated circadian rhythms are identified as major disease-relevant pathomechanistic drivers. We discuss the role of reactive oxygen species and present results from antioxidant interventions. Lastly, we provide an overview of oxidative stress markers and adverse redox processes reported for noise-exposed animals and humans. This position paper summarizes all available epidemiological, clinical, and preclinical evidence of transportation noise as an important environmental risk factor for public health and discusses its implications on the population level.

Mitochondrial Reactive Oxygen Species and Lytic Programmed Cell Death in Acute Inflammation.

Significance: Redox signaling through mitochondrial reactive oxygen species (mtROS) has a key role in several mechanisms of regulated cell death (RCD), necroptosis, ferroptosis, pyroptosis, and apoptosis, thereby decisively contributing to inflammatory disorders. The role of mtROS in apoptosis has been extensively addressed, but their involvement in necrotic-like RCD has just started being elucidated, providing novel insights into the pathophysiology of acute inflammation. Recent Advances: p53 together with mtROS drive necroptosis in acute inflammation through downregulation of sulfiredoxin and peroxiredoxin 3. Mitochondrial hydroorotate dehydrogenase is a key redox system in the regulation of ferroptosis. In addition, a noncanonical pathway, which generates mtROS through the Ragulator-Rag complex and acts via mTORC1 to promote gasdermin D oligomerization, triggers pyroptosis. Critical Issues: mtROS trigger positive feedback loops leading to lytic RCD in conjunction with the necrosome, the inflammasome, glutathione depletion, and glutathione peroxidase 4 deficiency. Future Directions: The precise mechanism of membrane rupture in ferroptosis and the contribution of mtROS to ferroptosis in inflammatory disorders are still unclear, which will need further research. Mitochondrial antioxidants may provide promising therapeutic approaches toward acute inflammatory disorders. However, establishing doses and windows of action will be required to optimize their therapeutic potential, and to avoid potential adverse side effects linked to the blockade of beneficial mtROS adaptive signaling. Antioxid. Redox Signal. 39, 708-727.

Importance of immunometabolic markers for the classification of patients with major depressive disorder using machine learning.

BACKGROUND: Although there is scientific evidence of the presence of immunometabolic alterations in major depression, not all patients present them. Recent studies point to the association between an inflammatory phenotype and certain clinical symptoms in patients with depression. The objective of our study was to classify major depression disorder patients using supervised learning algorithms or machine learning, based on immunometabolic and oxidative stress biomarkers and lifestyle habits. METHODS: Taking into account a series of inflammatory and oxidative stress biomarkers (C-reactive protein (CRP), tumor necrosis factor (TNF), 4-hydroxynonenal (HNE) and glutathione), metabolic risk markers (blood pressure, waist circumference and glucose, triglyceride and cholesterol levels) and lifestyle habits of the participants (physical activity, smoking and alcohol consumption), a study was carried out using machine learning in a sample of 171 participants, 91 patients with depression (71.42% women, mean age = 50.64) and 80 healthy subjects (67.50% women, mean age = 49.12). The algorithm used was the support vector machine, performing cross validation, by which the subdivision of the sample in training (70%) and test (30%) was carried out in order to estimate the precision of the model. The prediction of belonging to the patient group (MDD patients versus control subjects), melancholic type (melancholic versus non-melancholic patients) or resistant depression group (treatment-resistant versus non-treatment-resistant) was based on the importance of each of the immunometabolic and lifestyle variables. RESULTS: With the application of the algorithm, controls versus patients, such as patients with melancholic symptoms versus non-melancholic symptoms, and resistant versus non-resistant symptoms in the test phase were optimally classified. The variables that showed greater importance, according to the results of the area under the ROC curve, for the discrimination between healthy subjects and patients with depression were current alcohol consumption (AUC = 0.62), TNF-α levels (AUC = 0.61), glutathione redox status (AUC = 0.60) and the performance of both moderate (AUC = 0.59) and vigorous physical exercise (AUC = 0.58). On the other hand, the most important variables for classifying melancholic patients in relation to lifestyle habits were past (AUC = 0.65) and current (AUC = 0.60) tobacco habit, as well as walking routinely (AUC = 0.59) and in relation to immunometabolic markers were the levels of CRP (AUC = 0.62) and glucose (AUC = 0.58). In the analysis of the importance of the variables for the classification of treatment-resistant patients versus non-resistant patients, the systolic blood pressure (SBP) variable was shown to be the most relevant (AUC = 0.67). Other immunometabolic variables were also among the most important such as TNF-α (AUC = 0.65) and waist circumference (AUC = 0.64). In this case, sex (AUC = 0.59) was also relevant along with alcohol (AUC = 0.58) and tobacco (AUC = 0.56) consumption. CONCLUSIONS: The results obtained in our study show that it is possible to predict the diagnosis of depression and its clinical typology from immunometabolic markers and lifestyle habits, using machine learning techniques. The use of this type of methodology could facilitate the identification of patients at risk of presenting depression and could be very useful for managing clinical heterogeneity.

Microsurgical anastomosis of the fallopian tubes after tubal ligation: a systematic review and meta-analysis.

OBJECTIVE: Between 20% and 30% of women who have undergone tubal ligation regret their decision. The alternative to regain fertility for these women is either in vitro fertilization or tubal re-anastomosis. This article presents a systematic review with meta-analysis to assess the current evidence on the efficacy of tubal recanalization surgery in patients who have previously undergone tubal ligation. STUDY DESIGN: The search was conducted in the World of Science (WOS) database, The Cochrane Library and ClinicalTrials.gov record using the keywords "tubal reversal", "tubal reanastomosis" and "tubal anastomosis". The review was carried out by two of the authors. Data from 22 studies were evaluated, comprising over 14,113 patients who underwent the studied surgery, following strict inclusion criteria: articles published between January 2012 and June 2022, in English and with a sample size bigger than 10 patients were included. A random-effects meta-analysis was performed. RESULTS: The overall pregnancy rate after anastomosis was found to be 65.3 % (95 % CI: 61.0-69.6). The percentage of women who had at least one live birth, known as the birth rate, was 42.6 % (95 % CI: 34.9-51.4). Adverse outcomes after surgery were also examined: the observed abortion rate among women who underwent surgery was 9.4 % (95 % CI: 7.0-11.7), and the overall ectopic pregnancy rate was 6.8 % (95 % CI: 4.6-9.0). No differences were found between the outcomes when differentiating surgical approaches: laparotomy, laparoscopy, or robotic-assisted surgery. The patient's age was identified as the most significant determining factor for fertility restoration. Finally, when comparing the results of tubal reversal with in vitro fertilization, reversal procedures appear more favorable for patients over 35 years old, while the results are similar for patients under 35 years old, but more data is needed to evaluate this finding. CONCLUSION: Therefore, the available literature review demonstrates that surgical anastomosis following tubal ligation is a reproducible technique with relevant success rates, performed by multiple expert groups worldwide.

p53 drives necroptosis via downregulation of sulfiredoxin and peroxiredoxin 3.

Mitochondrial dysfunction is a key contributor to necroptosis. We have investigated the contribution of p53, sulfiredoxin, and mitochondrial peroxiredoxin 3 to necroptosis in acute pancreatitis. Late during the course of pancreatitis, p53 was localized in mitochondria of pancreatic cells undergoing necroptosis. In mice lacking p53, necroptosis was absent, and levels of PGC-1α, peroxiredoxin 3 and sulfiredoxin were upregulated. During the early stage of pancreatitis, prior to necroptosis, sulfiredoxin was upregulated and localized into mitochondria. In mice lacking sulfiredoxin with pancreatitis, peroxiredoxin 3 was hyperoxidized, p53 localized in mitochondria, and necroptosis occurred faster; which was prevented by Mito-TEMPO. In obese mice, necroptosis occurred in pancreas and adipose tissue. The lack of p53 up-regulated sulfiredoxin and abrogated necroptosis in pancreas and adipose tissue from obese mice. We describe here a positive feedback between mitochondrial H2O2 and p53 that downregulates sulfiredoxin and peroxiredoxin 3 leading to necroptosis in inflammation and obesity.

"Science in action": The politics of hands-on display at the New York Museum of Science and Industry.

This article analyzes the changing politics of hands-on display at the New York Museum of Science and Industry by following its urban deambulation within Midtown Manhattan, which went hand in hand with sharp shifts in promoters, narrative, and exhibition techniques. The museum was inaugurated in 1927 as the Museum of the Peaceful Arts on the 7th and 8th floors of the Scientific American Building. It changed its name in 1930 to the New York Museum of Science and Industry while on the 4th floor of the Daily News Building, and it was close to being renamed the Science Center when it finally moved in 1936 to the ground floor of the Rockefeller Center. The analysis of how the political agenda of the different promoters of the New York Museum of Science and Industry was spatially and performatively inscribed in each of its sites suggests that the 1930s boom of visitor-operated exhibits had nothing to do with an Exploratorium-like rhetoric of democratic empowerment. The social paternalistic ideology of the vocational education movement, the ideas on innovation of the early sociology of invention, and the corporate behavioral approach to mass communications are more suitable contexts in which to understand the changing politics of hands-on display in interwar American museums of science and industry.

Downregulation of thioredoxin-1-dependent CD95 S-nitrosation by Sorafenib reduces liver cancer.

Hepatocellular carcinoma (HCC) represents 80% of the primary hepatic neoplasms. It is the sixth most frequent neoplasm, the fourth cause of cancer-related death, and 7% of registered malignancies. Sorafenib is the first line molecular targeted therapy for patients in advanced stage of HCC. The present study shows that Sorafenib exerts free radical scavenging properties associated with the downregulation of nuclear factor E2-related factor 2 (Nrf2)-regulated thioredoxin 1 (Trx1) expression in liver cancer cells. The experimental downregulation and/or overexpression strategies showed that Trx1 induced activation of nitric oxide synthase (NOS) type 3 (NOS3) and S-nitrosation (SNO) of CD95 receptor leading to an increase of caspase-8 activity and cell proliferation, as well as reduction of caspase-3 activity in liver cancer cells. In addition, Sorafenib transiently increased mRNA expression and activity of S-nitrosoglutathione reductase (GSNOR) in HepG2 cells. Different experimental models of hepatocarcinogenesis based on the subcutaneous implantation of HepG2 cells in nude mice, as well as the induction of HCC by diethylnitrosamine (DEN) confirmed the relevance of Trx1 downregulation during the proapoptotic and antiproliferative properties induced by Sorafenib. In conclusion, the induction of apoptosis and antiproliferative properties by Sorafenib were related to Trx1 downregulation that appeared to play a relevant role on SNO of NOS3 and CD95 in HepG2 cells. The transient increase of GSNOR might also participate in the deactivation of CD95-dependent proliferative signaling in liver cancer cells.

Blockade of the trans-sulfuration pathway in acute pancreatitis due to nitration of cystathionine ß-synthase.

Acute pancreatitis is an inflammatory process of the pancreatic gland that may lead to dysregulation of the trans-sulfuration pathway. The aims of this work were firstly to study the methionine cycle as well as the trans-sulfuration pathway using metabolomic and proteomic approaches identifying the causes of this dysregulation in an experimental model of acute pancreatitis; and secondly to reveal the effects of S-adenosylmethionine administration on these pathways. Acute pancreatitis was induced by cerulein in mice, and a group of animals received S-adenosylmethionine treatment. Cerulein-induced acute pancreatitis rapidly caused marked depletion of methionine, S-adenosylmethionine, 5'-methylthioadenosine, cystathionine, cysteine, and glutathione levels in pancreas, but S-adenosylhomocysteine and homocysteine remained unchanged. Protein steady-state levels of S-adenosylhomocysteine-hydrolase and cystathionine gamma-lyase diminished but methylthioadenosine phosphorylase levels increased in pancreas with acute pancreatitis. Although cystathionine ß-synthase protein levels did not change with acute pancreatitis, Nos2 mRNA and protein levels were markedly up-regulated and caused tyrosine nitration of cystathionine ß-synthase in pancreas. S-adenosylmethionine administration enhanced Nos2 mRNA expression and cystathionine ß-synthase nitration and triggered homocysteine accumulation in acute pancreatitis. Furthermore, S-adenosylmethionine administration promoted enrichment of the euchromatin marker H3K4me3 in the promoters of Tnf-α, Il-6, and Nos2 and enhanced the mRNA up-regulation of these genes. Accordingly, S-adenosylmethionine administration increased inflammatory infiltrate and edema in pancreas with acute pancreatitis. In conclusion, tyrosine-nitration of cystathionine ß-synthase blockades the trans-sulfuration pathway in acute pancreatitis promoting homocysteine accumulation upon S-adenosylmethionine treatment.

Nuclear Factor Kappa B Signaling Complexes in Acute Inflammation.

Significance: Nuclear factor kappa B (NF-κB) is a master regulator of the inflammatory response and represents a key regulatory node in the complex inflammatory signaling network. In addition, selective NF-κB transcriptional activity on specific target genes occurs through the control of redox-sensitive NF-κB interactions. Recent Advances: The selective NF-κB response is mediated by redox-modulated NF-κB complexes with ribosomal protein S3 (RPS3), Pirin (PIR). cAMP response element-binding (CREB)-binding protein (CBP)/p300, peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), activator protein-1 (AP-1), signal transducer and activator of transcription 3 (STAT3), early growth response protein 1 (EGR-1), and SP-1. NF-κB is cooperatively coactivated with AP-1, STAT3, EGR-1, and SP-1 during the inflammatory process, whereas NF-κB complexes with CBP/p300 and PGC-1α regulate the expression of antioxidant genes. PGC-1α may act as selective repressor of phospho-p65 toward interleukin-6 (IL-6) in acute inflammation. p65 and nuclear factor erythroid 2-related factor 2 (NRF2) compete for binding to coactivator CBP/p300 playing opposite roles in the regulation of inflammatory genes. S-nitrosylation or tyrosine nitration favors the recruitment of specific NF-κB subunits to κB sites. Critical Issues: NF-κB is a redox-sensitive transcription factor that forms specific signaling complexes to regulate selectively the expression of target genes in acute inflammation. Protein-protein interactions with coregulatory proteins, other transcription factors, and chromatin-remodeling proteins provide transcriptional specificity to NF-κB. Furthermore, different NF-κB subunits may form distinct redox-sensitive homo- and heterodimers with distinct affinities for κB sites. Future Directions: Further research is required to elucidate the whole NF-κB interactome to fully characterize the complex NF-κB signaling network in redox signaling, inflammation, and cancer.

p38α deficiency restrains liver regeneration after partial hepatectomy triggering oxidative stress and liver injury.

p38α MAPK negatively regulates the G1/S and G2/M cell cycle transitions. However, liver-specific p38α deficiency impairs cytokinesis and reduces hepatocyte proliferation during cirrhosis and aging in mice. In this work, we have studied how p38α down-regulation affects hepatocyte proliferation after partial hepatectomy, focusing on mitotic progression, cytokinesis and oxidative stress. We found that p38α deficiency triggered up-regulation of cyclins A1, B1, B2, and D1 under basal conditions and after hepatectomy. Moreover, p38α-deficient hepatocytes showed enhanced binucleation and increased levels of phospho-histone H3 but impaired phosphorylation of MNK1 after hepatectomy. The recovery of liver mass was transiently delayed in mice with p38α-deficient hepatocytes vs wild type mice. We also found that p38α deficiency caused glutathione oxidation in the liver, increased plasma aminotransferases and lactate dehydrogenase activities, and decreased plasma protein levels after hepatectomy. Interestingly, p38α silencing in isolated hepatocytes markedly decreased phospho-MNK1 levels, and silencing of either p38α or Mnk1 enhanced binucleation of hepatocytes in culture. In conclusion, p38α deficiency impairs mitotic progression in hepatocytes and restrains the recovery of liver mass after partial hepatectomy. Our results also indicate that p38α regulates cytokinesis by activating MNK1 and redox modulation.

Role of obesity in the release of extracellular nucleosomes in acute pancreatitis: a clinical and experimental study.

BACKGROUND/OBJECTIVES: A high body mass index increases the risk of severe pancreatitis and associated mortality. Our aims were: (1) To determine whether obesity affects the release of extracellular nucleosomes in patients with pancreatitis; (2) To determine whether pancreatic ascites confers lipotoxicity and triggers the release of extracellular nucleosomes in lean and obese rats. METHODS: DNA and nucleosomes were determined in plasma from patients with mild or moderately severe acute pancreatitis either with normal or high body mass index (BMI). Lipids from pancreatic ascites from lean and obese rats were analyzed and the associated toxicity measured in vitro in RAW 264.7 macrophages. The inflammatory response, extracellular DNA and nucleosomes were determined in lean or obese rats with pancreatitis after peritoneal lavage. RESULTS: Nucleosome levels in plasma from obese patients with mild pancreatitis were higher than in normal BMI patients; these levels markedly increased in obese patients with moderately severe pancreatitis vs. those with normal BMI. Ascites from obese rats exhibited high levels of palmitic, oleic, stearic, and arachidonic acids. Necrosis and histone 4 citrullination-marker of extracellular traps-increased in macrophages incubated with ascites from obese rats but not with ascites from lean rats. Peritoneal lavage abrogated the increase in DNA and nucleosomes in plasma from lean or obese rats with pancreatitis. It prevented fat necrosis and induction of HIF-related genes in lung. CONCLUSIONS: Extracellular nucleosomes are intensely released in obese patients with acute pancreatitis. Pancreatitis-associated ascitic fluid triggers the release of extracellular nucleosomes in rats with severe pancreatitis.

Obesity causes PGC-1α deficiency in the pancreas leading to marked IL-6 upregulation via NF-κB in acute pancreatitis.

Obesity is associated with local and systemic complications in acute pancreatitis. PPARγ coactivator 1α (PGC-1α) is a transcriptional coactivator and master regulator of mitochondrial biogenesis that exhibits dysregulation in obese subjects. Our aims were: (1) to study PGC-1α levels in pancreas from lean or obese rats and mice with acute pancreatitis; and (2) to determine the role of PGC-1α in the inflammatory response during acute pancreatitis elucidating the signaling pathways regulated by PGC-1α. Lean and obese Zucker rats and lean and obese C57BL6 mice were used first; subsequently, wild-type and PGC-1α knockout (KO) mice with cerulein-induced pancreatitis were used to assess the inflammatory response and expression of target genes. Ppargc1a mRNA and protein levels were markedly downregulated in pancreas of obese rats and mice versus lean animals. PGC-1α protein levels increased in pancreas of lean mice with acute pancreatitis, but not in obese mice with pancreatitis. Interleukin-6 (Il6) mRNA levels were dramatically upregulated in pancreas of PGC-1α KO mice after cerulein-induced pancreatitis in comparison with wild-type mice with pancreatitis. Edema and the inflammatory infiltrate were more intense in pancreas from PGC-1α KO mice than in wild-type mice. The lack of PGC-1α markedly enhanced nuclear translocation of phospho-p65 and recruitment of p65 to Il6 promoter. PGC-1α bound phospho-p65 in pancreas during pancreatitis in wild-type mice. Glutathione depletion in cerulein-induced pancreatitis was more severe in KO mice than in wild-type mice. PGC-1α KO mice with pancreatitis, but not wild-type mice, exhibited increased myeloperoxidase activity in the lungs, together with alveolar wall thickening and collapse, which were abrogated by blockade of the IL-6 receptor glycoprotein 130 with LMT-28. In conclusion, obese rodents exhibit PGC-1α deficiency in the pancreas. PGC-1α acts as selective repressor of nuclear factor-κB (NF-κB) towards IL-6 in pancreas. PGC-1α deficiency markedly enhanced NF-κB-mediated upregulation of Il6 in pancreas in pancreatitis, leading to a severe inflammatory response. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Age-dependent regulation of antioxidant genes by p38α MAPK in the liver.

p38α is a redox sensitive MAPK activated by pro-inflammatory cytokines and environmental, genotoxic and endoplasmic reticulum stresses. The aim of this work was to assess whether p38α controls the antioxidant defense in the liver, and if so, to elucidate the mechanism(s) involved and the age-related changes. For this purpose, we used liver-specific p38α-deficient mice at two different ages: young-mice (4 months-old) and old-mice (24 months-old). The liver of young p38α knock-out mice exhibited a decrease in GSH levels and an increase in GSSG/GSH ratio and malondialdehyde levels. However, old mice deficient in p38α had higher hepatic GSH levels and lower GSSG/GSH ratio than young p38α knock-out mice. Liver-specific p38α deficiency triggered a dramatic down-regulation of the mRNAs of the key antioxidant enzymes glutamate cysteine ligase, superoxide dismutase 1, superoxide dismutase 2, and catalase in young mice, which seems mediated by the lack of p65 recruitment to their promoters. Nrf-2 nuclear levels did not change significantly in the liver of young mice upon p38α deficiency, but nuclear levels of phospho-p65 and PGC-1α decreased in these mice. p38α-dependent activation of NF-κB seems to occur through classical IκB Kinase and via ribosomal S6 kinase1 and AKT in young mice. However, unexpectedly the long-term deficiency in p38α triggers a compensatory up-regulation of antioxidant enzymes via NF-κB activation and recruitment of p65 to their promoters. In conclusion, p38α MAPK maintains the expression of antioxidant genes in liver of young animals via NF-κΒ under basal conditions, whereas its long-term deficiency triggers compensatory up-regulation of antioxidant enzymes through NF-κΒ.

Chronic aspartame intake causes changes in the trans-sulphuration pathway, glutathione depletion and liver damage in mice.

No-caloric sweeteners, such as aspartame, are widely used in various food and beverages to prevent the increasing rates of obesity and diabetes mellitus, acting as tools in helping control caloric intake. Aspartame is metabolized to phenylalanine, aspartic acid, and methanol. Our aim was to study the effect of chronic administration of aspartame on glutathione redox status and on the trans-sulphuration pathway in mouse liver. Mice were divided into three groups: control; treated daily with aspartame for 90 days; and treated with aspartame plus N-acetylcysteine (NAC). Chronic administration of aspartame increased plasma alanine aminotransferase (ALT) and aspartate aminotransferase activities and caused liver injury as well as marked decreased hepatic levels of reduced glutathione (GSH), oxidized glutathione (GSSG), γ-glutamylcysteine ​​(γ-GC), and most metabolites of the trans-sulphuration pathway, such as cysteine, S-adenosylmethionine (SAM), and S-adenosylhomocysteine ​​(SAH). Aspartame also triggered a decrease in mRNA and protein levels of the catalytic subunit of glutamate cysteine ligase (GCLc) and cystathionine γ-lyase, and in protein levels of methionine adenosyltransferase 1A and 2A. N-acetylcysteine prevented the aspartame-induced liver injury and the increase in plasma ALT activity as well as the decrease in GSH, γ-GC, cysteine, SAM and SAH levels and GCLc protein levels. In conclusion, chronic administration of aspartame caused marked hepatic GSH depletion, which should be ascribed to GCLc down-regulation and decreased cysteine levels. Aspartame triggered blockade of the trans-sulphuration pathway at two steps, cystathionine γ-lyase and methionine adenosyltransferases. NAC restored glutathione levels as well as the impairment of the trans-sulphuration pathway.

p38α regulates actin cytoskeleton and cytokinesis in hepatocytes during development and aging.

BACKGROUND: Hepatocyte poliploidization is an age-dependent process, being cytokinesis failure the main mechanism of polyploid hepatocyte formation. Our aim was to study the role of p38α MAPK in the regulation of actin cytoskeleton and cytokinesis in hepatocytes during development and aging. METHODS: Wild type and p38α liver-specific knock out mice at different ages (after weaning, adults and old) were used. RESULTS: We show that p38α MAPK deficiency induces actin disassembly upon aging and also cytokinesis failure leading to enhanced binucleation. Although the steady state levels of cyclin D1 in wild type and p38α knock out old livers remained unaffected, cyclin B1- a marker for G2/M transition- was significantly overexpressed in p38α knock out mice. Our findings suggest that hepatocytes do enter into S phase but they do not complete cell division upon p38α deficiency leading to cytokinesis failure and binucleation. Moreover, old liver-specific p38α MAPK knock out mice exhibited reduced F-actin polymerization and a dramatic loss of actin cytoskeleton. This was associated with abnormal hyperactivation of RhoA and Cdc42 GTPases. Long-term p38α deficiency drives to inactivation of HSP27, which seems to account for the impairment in actin cytoskeleton as Hsp27-silencing decreased the number and length of actin filaments in isolated hepatocytes. CONCLUSIONS: p38α MAPK is essential for actin dynamics with age in hepatocytes.

Redox signaling in the gastrointestinal tract.

Redox signaling regulates physiological self-renewal, proliferation, migration and differentiation in gastrointestinal epithelium by modulating Wnt/ß-catenin and Notch signaling pathways mainly through NADPH oxidases (NOXs). In the intestine, intracellular and extracellular thiol redox status modulates the proliferative potential of epithelial cells. Furthermore, commensal bacteria contribute to intestine epithelial homeostasis through NOX1- and dual oxidase 2-derived reactive oxygen species (ROS). The loss of redox homeostasis is involved in the pathogenesis and development of a wide diversity of gastrointestinal disorders, such as Barrett's esophagus, esophageal adenocarcinoma, peptic ulcer, gastric cancer, ischemic intestinal injury, celiac disease, inflammatory bowel disease and colorectal cancer. The overproduction of superoxide anion together with inactivation of superoxide dismutase are involved in the pathogenesis of Barrett's esophagus and its transformation to adenocarcinoma. In Helicobacter pylori-induced peptic ulcer, oxidative stress derived from the leukocyte infiltrate and NOX1 aggravates mucosal damage, especially in HspB+ strains that downregulate Nrf2. In celiac disease, oxidative stress mediates most of the cytotoxic effects induced by gluten peptides and increases transglutaminase levels, whereas nitrosative stress contributes to the impairment of tight junctions. Progression of inflammatory bowel disease relies on the balance between pro-inflammatory redox-sensitive pathways, such as NLRP3 inflammasome and NF-κB, and the adaptive up-regulation of Mn superoxide dismutase and glutathione peroxidase 2. In colorectal cancer, redox signaling exhibits two Janus faces: On the one hand, NOX1 up-regulation and derived hydrogen peroxide enhance Wnt/ß-catenin and Notch proliferating pathways; on the other hand, ROS may disrupt tumor progression through different pro-apoptotic mechanisms. In conclusion, redox signaling plays a critical role in the physiology and pathophysiology of gastrointestinal tract.

Epigenetic Regulation of Early- and Late-Response Genes in Acute Pancreatitis.

Chromatin remodeling seems to regulate the patterns of proinflammatory genes. Our aim was to provide new insights into the epigenetic mechanisms that control transcriptional activation of early- and late-response genes in initiation and development of severe acute pancreatitis as a model of acute inflammation. Chromatin changes were studied by chromatin immunoprecipitation analysis, nucleosome positioning, and determination of histone modifications in promoters of proinflammatory genes in vivo in the course of taurocholate-induced necrotizing pancreatitis in rats and in vitro in rat pancreatic AR42J acinar cells stimulated with taurocholate or TNF-α. Here we show that the upregulation of early and late inflammatory genes rely on histone acetylation associated with recruitment of histone acetyltransferase CBP. Chromatin remodeling of early genes during the inflammatory response in vivo is characterized by a rapid and transient increase in H3K14ac, H3K27ac, and H4K5ac as well as by recruitment of chromatin-remodeling complex containing BRG-1. Chromatin remodeling in late genes is characterized by a late and marked increase in histone methylation, particularly in H3K4. JNK and p38 MAPK drive the recruitment of transcription factors and the subsequent upregulation of early and late inflammatory genes, which is associated with nuclear translocation of the early gene Egr-1 In conclusion, specific and strictly ordered epigenetic markers such as histone acetylation and methylation, as well as recruitment of BRG-1-containing remodeling complex are associated with the upregulation of both early and late proinflammatory genes in acute pancreatitis. Our findings highlight the importance of epigenetic regulatory mechanisms in the control of the inflammatory cascade.