Oxidative DNA damage and antioxidant activity in patients with inflammatory bowel disease

Selenium, Immunity, and Inflammatory Bowel Disease

Dietary intervention is a subject of growing interest in the management of inflammatory bowel disease (IBD), as new incident cases across the globe are rapidly rising, suggesting environmental factors as contributing elements. Dietary components and micronutrients have been associated with IBD pathogenesis or reductions in disease severity. Selenium, a diet-derived essential micronutrient that is important for proper immune system function, has received limited attention in the context of IBD. Selenium deficiency is a common finding in patients with IBD, but few clinical trials have been published to address the consequences of this deficiency. Here, we review the physiological and immunological roles of selenium and its putative role in IBD, and draw attention to knowledge gaps and unresolved issues, with the goal of stimulating more research on selenium in IBD.

A living organoid biobank of patients with Crohn's disease reveals molecular subtypes for personalized therapeutics

Crohn's disease (CD) is a complex and heterogeneous condition with no perfect preclinical model or cure. To address this, we explore adult stem cell-derived organoids that retain their tissue identity and disease-driving traits. We prospectively create a biobank of CD patient-derived organoid cultures (PDOs) from colonic biopsies of 53 subjects across all clinical subtypes and healthy subjects. Gene expression analyses enabled benchmarking of PDOs as tools for modeling the colonic epithelium in active disease and identified two major molecular subtypes: immune-deficient infectious CD (IDICD) and stress and senescence-induced fibrostenotic CD (S2FCD). Each subtype shows internal consistency in the transcriptome, genome, and phenome. The spectrum of morphometric, phenotypic, and functional changes within the "living biobank" reveals distinct differences between the molecular subtypes. Drug screens reverse subtype-specific phenotypes, suggesting phenotyped-genotyped CD PDOs can bridge basic biology and patient trials by enabling preclinical phase "0" human trials for personalized therapeutics.

A curcumin-loaded biopolymeric nanocomposite alleviates dextran sulfate sodium induced ulcerative colitis via suppression of inflammation and oxidative stress

Functional drugs nano delivery systems manufactured from natural active products are promising for the field of biomedicines. In this study, an anti-ulcerative colitis (UC) curcumin loaded biopolymeric nanocomposite (CZNH) was fabricated and investigated. CZNH nanocomposite was obtained using the anti-solvent precipitation method, wherein curcumin-loaded zein colloidal particles served as the core, while sodium casein (NaCas) and hyaluronic acid (HA) formed the outermost layer of CZNH nanocomposite. Fourier transform infrared (FT-IR) spectrum and transmission electron microscopy (TEM) findings demonstrated that CZNH nanocomposite was a double-layer spherical micelle (250 nm) resulting from the hydrogen bond interactions and electrostatic adsorptions between zein, NaCas, and HA. Furthermore, CZNH nanocomposite exhibited prominent resuspension and storage stability in aqueous solution, which can be stored at 4 °C for approximately 30 days. In vivo anti-UC studies showed that CZNH nanocomposite could effectively alleviate UC symptoms via mediating inflammatory factors [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6], myeloperoxidase (MPO), and oxidative stress factor [malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)]. This study suggested that the CZNH nanocomposite showed great promise as an efficient curcumin nanocarrier for UC therapy.

Association of Glutathione Transferase M1, T1, P1 and A1 Gene Polymorphism and Susceptibility to IgA Vasculitis

Endothelial cell injury is a hallmark of IgA vasculitis (IgAV), possibly associated with various factors, including oxidative stress. Certain single nucleotide polymorphisms (SNPs) of glutathione S-transferases (GST) genes have been shown to increase susceptibility to oxidative stress. The objective of our study was to evaluate the gene polymorphisms of GSTM1, GSTT1, GSTP1, and GSTA1 in patients with IgAV. DNA was extracted from the blood of 124 children with IgAV and 168 age-matched healthy controls. A higher frequency of the GSTM1 null genotype was observed in patients with gastrointestinal (GI) system involvement compared to those without GI system involvement (51.5% vs. 28.6%, p = 0.011). Additionally, the GSTM1 null genotype was less prevalent (30.8% vs. 69.2%, p = 0.032), while the GSTP1 Val/Val genotype was significantly more prevalent in patients who developed urogenital complications (scrotal swelling) during the course of the disease (60% vs. 40%, p = 0.039). This study is the first to suggest an association between GSTM1 and GSTP1 polymorphisms and various phenotypes observed during the clinical course of IgAV in the pediatric population. However, it was performed on a national and likely single ethnic cohort, too small for definitive conclusions, so larger studies are needed to confirm this association.

Role of Mitochondria in Intestinal Epithelial Barrier Dysfunction in Inflammatory Bowel Disease

Abstract

Inflammatory bowel disease (IBD) is widespread in industrial countries with every 20th citizen being affected. Dysregulation of the epithelial barrier function is considered to play a key role in IBD. Permeability of the intestinal epithelium depends mostly on its self-renewal potential and the condition of intercellular junctions. Mitochondria are involved in regulating various intracellular processes in addition to their energy function. Recent data implicate mitochondria in intestinal epithelial barrier regulation and IBD. Mitochondrial dysfunction is possibly one of the factors that underlie the structural abnormalities of tight junctions and the cytoskeleton in intestinal epithelial cells and decrease the self-renewal capacity of the epithelium. The barrier function of the intestinal epithelium is consequently distorted, and IBD develops. The mechanisms of these processes are still unclear and require further research.

Cooperative interactions between Veillonella ratti and Lactobacillus acidophilus ameliorate DSS-induced ulcerative colitis in mice

Veillonella and Lactobacillus species are key regulators of a healthy gut environment through metabolic cross-feeding, influencing lactic acid and short-chain fatty acid (SCFA) levels, which are crucial for gut health. This study aims to investigate how Veillonella ratti (V. ratti) and Lactobacillus acidophilus (LA) interact with each other and alleviate dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in a mouse model. We assess their metabolic interactions regarding carbon sources through co-culturing in a modified medium. In the in vitro experiments, V. ratti and LA were inoculated in mono-cultures and co-culture, and viable cell counts, OD600, pH, lactic acid, glucose and SCFAs were measured. For the in vivo experiment, 60 C57BL/6 mice were randomly divided into five groups and administered V. ratti and LA alone or in combination via oral gavage (1 × 109 CFU mL-1 per day per mouse) for 14 days. On the seventh day, 2.5% DSS was added to the drinking water to induce colitis. The effects of these probiotics on UC were evaluated by assessing intestinal barrier integrity and intestinal inflammation in the gut microenvironment. In vitro results demonstrated that co-culturing V. ratti with LA significantly increased viable cell numbers, lactic acid production, and SCFA production, while reducing pH and glucose levels in the medium. In vivo findings revealed that intervention with V. ratti, particularly in combination with LA, alleviated symptoms, including weight loss, colon shortening, and tissue damage. These probiotics mitigated intestinal inflammation by down-regulating pro-inflammatory molecules, such as IL-6, IL-1β, IL-γ, iNOS, and IFN-γ, as well as oxidative stress markers, including MDA and MPO. Concurrently, they upregulated the activity of anti-inflammatory enzymes, namely, SOD and GSH, and promoted the production of SCFAs. The combined intervention of V. ratti and LA significantly increased acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and total SCFAs in cecal contents. Furthermore, the intervention of V. ratti and LA increased the abundance of beneficial bacteria, such as Akkermansia, while reducing the abundance of harmful bacteria, such as Escherichia-Shigella and Desulfovibrio, thereby mitigating excessive inflammation. These findings highlight the enhanced therapeutic effects resulting from the interactions between V. ratti and LA, demonstrating the potential of this combined probiotic approach.

Atractylone in the Atractylodes macrocephala Rhizoma Essential Oil and Its Anti-Inflammatory Activity

The aim of this study was to conduct a screening of potential therapeutic compounds found in the Atractylodes macrocephala rhizoma essential oil (AO) and explore its mechanism of action in the treatment of ulcerative colitis (UC). An inflammation cell model was employed in conjunction with phospho-antibody array technology to explore potential therapeutic compounds of AO and their anti-inflammatory and antioxidant effects. Furthermore, we assessed their efficacy and mechanisms of action in treating dextran sulfate sodium (DSS)-induced colitis in mice. Via the screening process, we identified atractylone (ATR) as the primary active compound in AO. It has been demonstrated that ATR can both decrease the levels of tumor necrosis factor (TNF)-α and reactive oxygen species (ROS) and increase the expression of adhesion proteins such as claudin, ZO-1, and occludin in vitro. Moreover, ATR has been shown to improve UC symptoms in vivo. Via a non-targeted metabolomics analysis of colon tissue, we identified 57 distinct metabolites that responded to ATR treatment. Subsequent analysis of the metabolic pathways revealed that the action of ATR was primarily focused on the amino acid metabolism pathway. In summary, ATR may alleviate the symptoms of UC by regulating multiple signaling pathways. Additionally, ATR has a comprehensive function in anti-inflammation, antioxidative stress, and intestinal injury reduction.

A Living Organoid Biobank of Crohn's Disease Patients Reveals Molecular Subtypes for Personalized Therapeutics

Crohn's disease (CD) is a complex, clinically heterogeneous disease of multifactorial origin; there is no perfect pre-clinical model, little insight into the basis for such heterogeneity, and still no cure. To address these unmet needs, we sought to explore the translational potential of adult stem cell-derived organoids that not only retain their tissue identity, but also their genetic and epigenetic disease-driving traits. We prospectively created a biobank of CD patient-derived organoid cultures (PDOs) using biopsied tissues from colons of 34 consecutive subjects representing all clinical subtypes (Montreal Classification B1-B3 and perianal disease). PDOs were generated also from healthy subjects. Comparative gene expression analyses enabled benchmarking of PDOs as tools for modeling the colonic epithelium in active disease and revealed that despite the clinical heterogeneity there are two major molecular subtypes: immune-deficient infectious-CD [IDICD] and stress and senescence-induced fibrostenotic-CD [S2FCD]. The transcriptome, genome and phenome show a surprising degree of internal consistency within each molecular subtype. The spectrum of morphometric, phenotypic, and functional changes within the "living biobank" reveals distinct differences between the molecular subtypes. These insights enabled drug screens that reversed subtype-specific phenotypes, e.g., impaired microbial clearance in IDICD was reversed using agonists for nuclear receptors, and senescence in S2FCD was rectified using senotherapeutics, but not vice versa . Phenotyped-genotyped CD-PDOs may fill the gap between basic biology and patient trials by enabling pre-clinical Phase '0' human trials for personalized therapeutics.

GRAPHIC ABSTRACT

In Brief

This work creates a prospectively biobanked phenotyped-genotyped Crohn's disease patient-derived organoids (CD-PDOs) as platforms for molecular subtyping of disease and for ushering personalized therapeutics.

HIGHLIGHTS

Prospectively biobanked CD-organoids recapitulate the disease epithelium in patientsThe phenome-transcriptome-genome of CD-organoids converge on two molecular subtypesOne subtype shows impaired microbial clearance, another increased cellular senescencePhenotyped-genotyped PDOs are then used for integrative and personalized therapeutics.

Functional amino acid supplementation attenuates the negative effects of plant-based nursery diets on the response of pigs to a subsequent Salmonella Typhimurium challenge

Functional amino acids (FAA) attenuate the effects of Salmonella challenge in pigs. However, this may be affected by protein source (PS). The objective of the present study was to determine the effects of nursery dietary PS and FAA supplementation on growth performance and immune status of pigs subsequently challenged with Salmonella Typhimurium (ST). Thirty-two weanling pigs (8.7 ± 0.23 kg) were assigned to a feeding program for 31 d in a 2 × 2 factorial arrangement. Factors were dietary PS (plant-based [PB] vs. animal-based [AB]) and FAA profile (basal [FAA-] or supplemented [FAA+; Thr, Met, and Trp at 120% of requirements]). Pigs were subsequently placed on a common grower diet and, after a 7-d adaptation, were inoculated with ST and monitored for 7 d postinoculation. Growth performance, rectal temperature, fecal score, gut health, ST shedding score, intestinal colonization and translocation, and blood parameters of acute-phase response and antioxidant balance were measured pre- and postinoculation. Data were analyzed with a 2 (AB vs. PB) × 2 (FAA- vs. FAA+) factorial arrangement of treatments and differences between means were considered significant at P ≤ 0.05. Postinoculation fecal score was worse, ST shedding, cecal myeloperoxidase, and cecal and colonic ST colonization were greater in PB compared to AB pigs (P < 0.05). Translocation of ST to spleen was decreased by FAA+ (P < 0.05), regardless of dietary PS. Postinoculation, AB pigs had greater average daily gain compared to PB-FAA- (P < 0.05). Pigs fed AB-FAA- showed increased average daily feed intake compared to PB-FAA- pigs (P < 0.05) and feed efficiency was increased in AB-FAA+ compared to PB-FAA- pigs (P < 0.05). Feeding PB ingredients in nursery diets seems to increase susceptibility of pigs to Salmonella. Moreover, FAA supplementation partially attenuated the negative effects of PB diets on the response of pigs to ST challenge.

The role of diet in genotoxicity of fecal water derived from IBD patients and healthy controls

Certain dietary factors with anti-inflammatory and/or anti-cancer properties would be a promising preventive strategy for inflammatory bowel disease (IBD) patients against developing colitis-associated colorectal cancer (CAC). In this study, fecal water (FW) was obtained from 80 IBD patients and 20 healthy controls (HCs). The comet assay was applied to determine the DNA damage induced by FW, and the protective potential of FW against hydrogen peroxide (H₂O₂) induced DNA damage in Caco-2 cells. Information on diet was obtained via food frequency questionnaires. The results showed that FW from IBD patients, especially patients with flares, induced higher levels of direct DNA damage in Caco-2 cells and showed less protection against H₂O₂-induced DNA damage, when compared to HCs. The DNA damage induced by FW was positively associated with consumption of processed meat and sugary foods, and nutrient intakes including heme iron and added sugars, whereas negatively correlated to intakes of soy products, and a dietary pattern characterized by high consumption of potatoes, white meat, nuts and seeds, eggs, legumes and soy products. FW from subjects with high coffee consumption protected against H₂O₂-induced DNA damage. These results can help to develop potential preventive strategies for IBD patients to reduce the CAC risk.

Neutrophil Extracellular Trap Density Increases With Increasing Histopathological Severity of Crohn's Disease

BACKGROUND

Intestinal neutrophil recruitment is a characteristic feature of the earliest stages of inflammatory bowel disease (IBD). Neutrophil elastase (NE) and myeloperoxidase (MPO) mediate the formation of neutrophil extracellular traps (NETs); NETs produce the bactericidal oxidant hypochlorous acid (HOCl), causing host tissue damage when unregulated. The project aim was to investigate the relationship between NET formation and clinical IBD in humans.

METHODS

Human intestinal biopsies were collected from Crohn's disease (CD) patients, endoscopically categorized as unaffected, transitional, or diseased, and assigned a histopathological score.

RESULTS

A significant linear correlation was identified between pathological score and cell viability (TUNEL+). Immunohistochemical analysis revealed the presence of NET markers NE, MPO, and citrullinated histone (CitH3) that increased significantly with increasing histopathological score. Diseased specimens showed greater MPO+-immunostaining than control (P < .0001) and unaffected CD (P < .0001), with transitional CD specimens also showing greater staining than controls (P < .05) and unaffected CD (P < .05). Similarly, NE+-immunostaining was elevated significantly in diseased CD than controls (P < .0001) and unaffected CD (P < .0001) and was significantly higher in transitional CD than in controls (P < .0001) and unaffected CD (P < .0001). The CitH3+-immunostaining of diseased CD was significantly higher than controls (P < .05), unaffected CD (P < .0001) and transitional CD (P < .05), with transitional CD specimens showing greater staining than unaffected CD (P < .01). Multiplex immunohistochemistry with z-stacking revealed colocalization of NE, MPO, CitH3, and DAPI (cell nuclei), confirming the NET assignment.

CONCLUSION

These data indicate an association between increased NET formation and CD severity, potentially due to excessive MPO-mediated HOCl production in the extracellular domain, causing host tissue damage that exacerbates CD.

Extracellular vesicles produced by the human commensal gut bacterium Bacteroides thetaiotaomicron affect host immune pathways in a cell-type specific manner that are altered in inflammatory bowel disease

The gastrointestinal (GI) tract harbours a complex microbial community, which contributes to its homeostasis. A disrupted microbiome can cause GI-related diseases, including inflammatory bowel disease (IBD), therefore identifying host-microbe interactions is crucial for better understanding gut health. Bacterial extracellular vesicles (BEVs), released into the gut lumen, can cross the mucus layer and access underlying immune cells. To study BEV-host interactions, we examined the influence of BEVs generated by the gut commensal bacterium, Bacteroides thetaiotaomicron, on host immune cells. Single-cell RNA sequencing data and host-microbe protein-protein interaction networks were used to predict the effect of BEVs on dendritic cells, macrophages and monocytes focusing on the Toll-like receptor (TLR) pathway. We identified biological processes affected in each immune cell type and cell-type specific processes including myeloid cell differentiation. TLR pathway analysis highlighted that BEV targets differ among cells and between the same cells in healthy versus disease (ulcerative colitis) conditions. The in silico findings were validated in BEV-monocyte co-cultures demonstrating the requirement for TLR4 and Toll-interleukin-1 receptor domain-containing adaptor protein (TIRAP) in BEV-elicited NF-kB activation. This study demonstrates that both cell-type and health status influence BEV-host communication. The results and the pipeline could facilitate BEV-based therapies for the treatment of IBD.

Ileal alkaline phosphatase is upregulated following functional amino acid supplementation in Salmonella Typhimurium-challenged pigs

We recently showed that functional amino acid (FAA) supplementation improves growth performance and immune status of Salmonella Typhimurium (ST)-challenged pigs, which was further improved by a longer adaptation period. It is expected that the effects are associated with increased activity of intestinal alkaline phosphatase (IAP). The objective of this study was to evaluate the effects of FAA supplementation and adaptation period on the ileal, cecal, and colonic activity of IAP in weaned pigs challenged with ST. In experiment 1, a total of 32 mixed-sex weanling pigs were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement with low (LP) or high protein (HP) content and basal (FAA-) or FAA profile (FAA+; Thr, Met, and Trp at 120% of requirements) as factors. In experiment 2, a total of 32 mixed-sex weanling pigs were randomly assigned to one of four dietary treatments, being FAA- fed throughout the experimental period (FAA-) or an FAA profile fed only in the post-inoculation (FAA + 0), for 1 wk pre- and post-inoculation (FAA + 1), or throughout the experimental period (FAA + 2). In experiments 1 and 2, after a 7- and 14-d adaptation period, respectively, pigs were inoculated with saline solution containing ST (3.3 and 2.2 × 109 CFU/mL, respectively). Plasma alkaline phosphatase was measured on days 0 and 7 post-inoculation in experiment 1, and IAP (ileum, cecum, and colon) was measured in experiments 1 and 2. Correlations among ileal IAP and serum albumin and haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), and reduced:oxidized glutathione, ileal myeloperoxidase, ST shedding and ileal colonization, and post-inoculation average daily gain, feed intake (ADFI), and gain:feed were also analyzed. In experiment 1, plasma alkaline phosphatase was decreased with ST inoculation and the overall content was increased in LP-FAA+ compared with LP-FAA- (P < 0.05). Moreover, ileal IAP was increased in FAA+ compared with FAA- pigs in both studies (P < 0.05) regardless of adaptation time (P > 0.05). IAP was positively correlated with MDA and ADFI and negatively correlated with SOD and ST shedding in experiment 1 (P < 0.05). These results demonstrate a positive effect of FAA supplementation, but not adaptation period, on ileal alkaline phosphatase activity in Salmonella-challenged pigs, which may be associated with improvements in antioxidant balance.

Interleukin -17 and oxidative stress in children with immunoglobulin A vasculitis

Objective: We aimed to investigate levels of interleukin-17 (IL-17) and oxidative stress in the active phase of immunoglobulin A vasculitis (IgAV) and determine whether a relationship exists among IL-17, oxidative stress, and system involvement.Method: Patients diagnosed with IgAV, who were not given non-steroidal anti-inflammatory or steroidal drugs within a month, were enrolled. Blood samples were taken in the active and remission phases of the disease. Malondialdehyde (lipid peroxidation marker), 8-hydroxydeoxyguanosine (DNA oxidation marker), total oxidant status (TOS) and total antioxidant status (TAS) levels for oxidative stress, and IL-17 levels were measured.Results: Forty-four patients aged 1.91-15.41 years were enrolled. IL-17 and TAS levels were significantly higher in the active phase of the disease than in the remission phase. 8-Hydroxydeoxyguanosine levels were higher in patients with gastrointestinal involvement than in patients without involvement in the active phase of the disease. A moderate positive correlation was observed between IL-17 and TAS in both active and remission phases.Conclusion: Our results showed increased DNA oxidation in patients with gastrointestinal involvement in the active phase of IgAV, for the first time. Higher IL-17 and TAS levels in the active phase of the disease and positive correlations of TAS and IL-17 in both active and remission phases suggest that IL-17 and oxidative stress may be related.

A longer adaptation period to a functional amino acid-supplemented diet improves growth performance and immune status of Salmonella Typhimurium-challenged pigs

We recently showed that dietary supplementation with key functional amino acids (FAA) improves growth performance and immune status of Salmonella Typhimurium (ST)-challenged pigs. It is not known if ST-challenged pigs will benefit from a longer adaptation period to FAA. The objective of this study was to evaluate the effects of different adaptation periods to diets containing FAA above requirements for growth on performance and immune response of weaned pigs subsequently challenged with ST. A total of 32 mixed-sex weanling pigs (11.6 ± 0.3 kg) were randomly assigned to 1 of 4 dietary treatments, being a basal amino acid (AA) profile fed throughout the experimental period (FAA-) or a functional AA profile (FAA+; Thr, Met, and Trp at 120% of requirements) fed only in the postinoculation (FAA+0), for 1 wk pre- and postinoculation (FAA+1), or throughout the experimental period (FAA+2). After a 14-d adaptation period, pigs were inoculated with ST (2.15 × 109 CFU/mL). Growth performance, body temperature, fecal score, acute-phase proteins, oxidant/antioxidant balance, score for ST shedding in feces and intestinal colonization, and fecal and digesta myeloperoxidase (MPO) were measured pre- and postinoculation. Postinoculation body temperature and fecal score, serum haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), and fecal MPO were increased while serum albumin and plasma reduced glutathione (GSH):oxidized glutathione (GSSG) were reduced compared to pre-inoculation (P < 0.05). Average daily gain and G:F were greater in FAA+2 pigs compared to FAA- pigs (P < 0.05). Serum albumin was higher in FAA+2 and FAA+1 compared to FAA+0 and FAA- pigs (P < 0.05) while FAA+2 pigs had lower haptoglobin compared to FAA- (P < 0.05). Plasma SOD was increased and GSH:GSSG was decreased in FAA- pigs compared to the other treatments (P < 0.05). Score for ST shedding in feces was progressively lower from d 1 to 6 regardless of treatment (P < 0.05) and was lower in FAA+2 pigs compared to FAA- and FAA+0 (P < 0.05). Counts of ST in colon digesta were higher in FAA- and FAA+0 pigs compared to FAA+2 (P < 0.05). Fecal and colonic digesta MPO were lower in FAA+2 and FAA+1 pigs compared to FAA- (P < 0.05). These results demonstrate a positive effect of a longer adaptation period to FAA-supplemented diets on performance and immune status of weaned pigs challenged with Salmonella.

Redox imbalance in Crohn's disease patients is modulated by Azathioprine

Background

Crohn's disease (CD) is a chronic inflammatory disease without a specific cause. Inflammation in these patients can disturb the oxidants/antioxidants balance and results in oxidative stress that plays a destructive role. This study aimed to evaluate the gene expression of sod1, sod2, cat, nrf2 and gp91phox in CD patients before and after Azathioprine (Aza) consumption.

Method

Peripheral bloodmononuclear cells (PBMCs) were separated from CD patients (n= 15, mean age = 33.6 ± 1.8) before and after treatment with Aza and healthy controls (n= 15, mean age = 31.5 ± 1.2). The expression levels of sod1, sod2, cat, nrf2 and gp91phox were measured in byusing real-time qRT-PCR technique.

Result

The expression levels of gp91phox (P-value < 0.001), cat (P-value < 0.05), sod1 (P-value < 0.001), nrf2 (P-value < 0.001) were significantly increased compared to control group. Following treatment with Aza, the decreased expression levels of gp91phox (P-value < 0.05), cat (P-value < 0.05), sod1(P-value < 0.001) and nrf2 (P-value < 0.001) were observed in CD patients.

Conclusion

Overall, our results showed that prescription of Azathioprine can lead to the altered expression of redox system-related genes in patients with CD.

Functional amino acid supplementation, regardless of dietary protein content, improves growth performance and immune status of weaned pigs challenged with Salmonella Typhimurium

High dietary protein may increase susceptibility of weaned pigs to enteric pathogens. Dietary supplementation with functional amino acids (FAA) may improve growth performance of pigs during disease challenge. The objective of this study was to evaluate the interactive effects of dietary protein content and FAA supplementation above requirements for growth on performance and immune response of weaned pigs challenged with Salmonella. Sixty-four mixed-sex weanling pigs (13.9 ± 0.82 kg) were randomly assigned to dietary treatments in a 2 × 2 factorial arrangement with low (LP) or high protein (HP) content and basal (AA-) or FAA profile (AA+; Thr, Met, and Trp at 120% of requirements) as factors. After a 7-d adaptation period, pigs were inoculated with either a sterile saline solution (CT) or saline solution containing Salmonella Typhimurium (ST; 3.3 × 109 CFU/mL). Growth performance, body temperature, fecal score, acute-phase proteins, oxidant/antioxidant balance, ST shedding score in feces and intestinal colonization, fecal and digesta myeloperoxidase (MPO), and plasma urea nitrogen (PUN) were measured pre- and postinoculation. There were no dietary effects on any measures pre-inoculation or post-CT inoculation (P > 0.05). Inoculation with ST increased body temperature and fecal score (P < 0.05), serum haptoglobin, plasma superoxide dismutase (SOD), malondialdehyde (MDA), PUN, and fecal MPO, and decreased serum albumin and plasma reduced glutathione (GSH):oxidized glutathione (GSSG) compared with CT pigs (P < 0.05). ST-inoculation reduced average daily gain (ADG) and feed intake (ADFI) vs. CT pigs (P < 0.05) but was increased by AA+ vs. AA- in ST pigs (P < 0.05). Serum albumin and GSH:GSSG were increased while haptoglobin and SOD were decreased in ST-inoculated pigs fed AA+ vs. AA- (P < 0.05). PUN was higher in HP vs. LP-fed pigs postinoculation (P < 0.05). Fecal ST score was increased in ST-inoculated pigs on days 1 and 2 postinoculation and declined by day 6 (P < 0.05) in all pigs while the overall score was reduced in AA+ vs. AA- pigs (P < 0.05). Cecal digesta ST score was higher in HP vs. LP-fed pigs and were lower in AA+ compared with AA- fed pigs in the colon (P < 0.05). Fecal and digesta MPO were reduced in ST pigs fed AA+ vs. AA- (P < 0.05). These results demonstrate a positive effect of FAA supplementation, with minimal effects of dietary protein, on performance and immune status in weaned pigs challenged with Salmonella.

SOD1 suppresses pro-inflammatory immune responses by protecting against oxidative stress in colitis

Superoxide dismutase 1 (SOD1) binds copper and zinc ions and is one of three superoxide dismutases responsible for destroying free superoxide radicals in the body. Reactive oxygen species (ROS), including free superoxide radicals, play important roles in colitis. However, the role of SOD1 in oxidative stress under colitis remains unclear. Here, we examined the role of SOD1 in the DSS-induced mouse model of colitis. SOD1 deficiency resulted in severe oxidative stress with body weight loss, epithelial barrier disruption and decreased antioxidant enzyme activities. The levels of neutrophils, monocytes, pro-inflammatory CD11c⁺ macrophages and CD11b⁺CD103^- dendritic cells (DCs) were increased, while anti-inflammatory CD206⁺ macrophages and CD11b^-CD103⁺ DCs were decreased, in DSS-treated SOD1-knockout (KO) mice compared to DSS-treated wild-type mice. Furthermore, rescue of SOD activity in SOD1-KO mice by oral gavage of B. amyloliquefaciens SOD (BA SOD) significantly ameliorated enhanced DSS-induced colitis in these mice by suppressing p38-MAPK/NF-κB signaling, which can induce inflammation and apoptosis. Taken together, our results suggest that SOD1-mediated inhibitory responses play a crucial role in limiting the development of DSS-induced colitis, and that BA SOD is a promising candidate for treating colitis.

Effects of saffron supplementation on oxidative/antioxidant status and severity of disease in ulcerative colitis patients: A randomized, double-blind, placebo-controlled study

Supplementation with saffron helps improve antioxidant status. Oxidative stress plays an important role in ulcerative colitis (UC). The present study aimed to investigate the effect of saffron supplementation on disease severity and Oxidative/Antioxidant factors in patients with UC. This randomized double-blinded study was conducted on 80 mild to moderate UC patients. Participants were randomly divided into intervention (100 mg saffron/daily) and placebo (100 mg maltodextrin/daily) groups. Of all the participants, 75 completed the study. After 8 weeks, there were significantly increased in the mean score of simple clinical colitis activity index questionnaire (3.83 ± 1.78 to 3 ± 1.60, p = .004), the serum levels of total antioxidant capacity (2.68 ± 0.90 to 2.79 ± 0.87, p = .016), superoxide dismutase (60.69 ± 9.59 to 66.30 ± 10.79, p = .009) and glutathione peroxidase (22.05 ± 14.27 to 29.67 ± 17.97, p = .011) in patients received saffron compared to the placebo group. Whereas, there was no significant difference in serum levels of malondialdehyde between the two groups. Finally, dietary saffron as an alternative therapy may effective in improving antioxidant factors and reducing the severity of disease in UC patients.

Galectin-1 reduces the severity of dextran sulfate sodium (DSS)-induced ulcerative colitis by suppressing inflammatory and oxidative stress response

Ulcerative colitis is an inflammatory bowel disease that affects a large number of people around the world. Galectin-1 is a β-galactoside-binding lectin with a broad range of biological activities. The effects of galectin-1 on dextran sulfate sodium (DSS)-induced ulcerative colitis in vivo is not clear. We investigated the effect of galectin-1 on colon morphology, cell proliferation, oxidative stress, antioxidant system, and proinflammatory/antiinflammatory cytokines in a DSS-induced mouse model of ulcerative colitis. Thirty-two C57BL/6 mice were randomly assigned to one of the four groups: control, acute colitis, galectin-1, and DSS+galectin-1. Controls were treated with phosphate-buffered saline (PBS) for seven days. Acute colitis was induced by 3% DSS in drinking water administered orally for five days. Mice in galectin-1 groups were treated with 1 mg/kg recombinant human galectin-1 in PBS for seven consecutive days. Oral DSS administration resulted in acute colitis by causing histopathological changes; an increase in disease activity index (DAI), lipid peroxidation (malondialdehyde [MDA]), myeloperoxidase (MPO), and tumor necrosis factor (TNF)-α levels; a decrease in body weight, colon length, cell proliferation index, catalase, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, and GSH and interleukin (IL)-10 levels. The treatment with galectin-1 attenuated DSS-induced acute colitis by reducing DAI, MDA, MPO, and TNF-α levels and by increasing body weight, colon length, cell proliferation, antioxidant enzyme activity, GSH, and IL-10 levels. These findings suggest that galectin-1 has proliferative, antioxidant, antiinflammatory, and cytoprotective effects against DSS-induced ulcerative colitis in mice. Due to its antiinflammatory and antioxidant activity galectin-1 may be effective in preventing and treating ulcerative colitis.

Inhibition of APE1/Ref-1 Redox Signaling Alleviates Intestinal Dysfunction and Damage to Myenteric Neurons in a Mouse Model of Spontaneous Chronic Colitis

BACKGROUND

Inflammatory bowel disease (IBD) associates with damage to the enteric nervous system (ENS), leading to gastrointestinal (GI) dysfunction. Oxidative stress is important for the pathophysiology of inflammation-induced enteric neuropathy and GI dysfunction. Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a dual functioning protein that is an essential regulator of the cellular response to oxidative stress. In this study, we aimed to determine whether an APE1/Ref-1 redox domain inhibitor, APX3330, alleviates inflammation-induced oxidative stress that leads to enteric neuropathy in the Winnie murine model of spontaneous chronic colitis.

METHODS

Winnie mice received APX3330 or vehicle via intraperitoneal injections over 2 weeks and were compared with C57BL/6 controls. In vivo disease activity and GI transit were evaluated. Ex vivo experiments were performed to assess functional parameters of colonic motility, immune cell infiltration, and changes to the ENS.

RESULTS

Targeting APE1/Ref-1 redox activity with APX3330 improved disease severity, reduced immune cell infiltration, restored GI function ,and provided neuroprotective effects to the enteric nervous system. Inhibition of APE1/Ref-1 redox signaling leading to reduced mitochondrial superoxide production, oxidative DNA damage, and translocation of high mobility group box 1 protein (HMGB1) was involved in neuroprotective effects of APX3330 in enteric neurons.

CONCLUSIONS

This study is the first to investigate inhibition of APE1/Ref-1's redox activity via APX3330 in an animal model of chronic intestinal inflammation. Inhibition of the redox function of APE1/Ref-1 is a novel strategy that might lead to a possible application of APX3330 for the treatment of IBD.

Intermittent hypoxia promotes carcinogenesis in azoxymethane and dextran sodium sulfate-induced colon cancer model

Intermittent hypoxia (IH), a characteristic of obstructive sleep apnea, is known to promote cancer progression and aggressiveness in mouse models. However, little is known regarding the effect of IH on cancer initiation. Here, the effect of IH on carcinogenesis was explored in azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon cancer models with three different protocols. In the first protocol, two other application time points (early or late initiation of IH) were applied. In the second protocol, mice were divided into only two groups, and then exposed to either N or IH conditions for 14 days. In the third protocol, a pharmacological inhibition study for anti-inflammation (5-aminosalicylate) or anti-oxidative stress (N-acetylcysteine [NAC]) was performed. The number of tumors was significantly higher in the IH-1 than in the N or IH-2 groups. 8-oxo-2'-deoxyguanosine (8-OHdG) levels were higher in tumors of the IH-1 group than in that of the N and IH-2 groups. Gene expression related to reactive oxygen species production was higher in the IH-1 group than in the N and IH-2 groups, and it showed a positive correlation with 8-OHdG levels. Prior to cancer development 8-OHdG levels were already elevated in colonic epithelial regions in the IH group, possibly due to an imbalance between oxidative stress and antioxidant systems. NAC treatment resulted in a significant reduction in the number of tumors in mice exposed to IH. In conclusion, IH promotes carcinogenesis in a chemically-induced colon cancer model where elevated 8-OHdG may contribute to the increased tumor induction.

Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerous in vitro and in vivo studies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.

HNE and cholesterol oxidation products in colorectal inflammation and carcinogenesis

Consistent experimental data suggest the importance of inflammation-associated oxidative stress in colorectal cancer (CRC) pathogenesis. Inflammatory bowel disease with chronic intestinal inflammation is now considered a precancerous condition. Oxidative stress is an essential feature of inflammation. Activation of redox-sensitive pro-inflammatory cell signals and inflammatory mediators concur to establish a pro-tumoral environment. In this frame, lipid oxidation products, namely 4-hydroxynonenal and oxysterols, can be produced in big quantity so as to be able to exert their function as inducers of cell signaling pathways of proliferation and survival. Notably, an important source of these two compounds is represented by a high fat diet, which is undoubtedly a risk factor for inflammation and CRC development. Current evidence for the emerging implication of these two oxidized lipids in inflammation and CRC development is discussed in this review.

Potential application of the oxidative nucleic acid damage biomarkers in detection of diseases

Reactive oxygen species (ROS) are generated after exposure to harmful environmental factors and during normal cellular metabolic processes. The balance of the generating and scavenging of ROS plays a significant role in living cells. The accumulation of ROS will lead to oxidative damage to biomolecules including nucleic acid. Although many types of oxidative nucleic acid damage products have been identified, 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoG) has been commonly chosen as the biomarkers of oxidative damage to DNA and RNA, respectively. It has been demonstrated that oxidative damage to nucleic acid is an initiator in pathogenesis of numerous diseases. Thus, oxidative nucleic acid damage biomarkers have the potential to be utilized for detection of diseases. Herein, we reviewed the relationship of oxidative nucleic acid damage and development of various diseases including cancers (colorectal cancer, gastrointestinal cancer, breast cancer, lung cancer, epithelial ovarian carcinoma, esophageal squamous cell carcinoma), neurodegenerative disorders and chronic diseases (diabetes and its complications, cardiovascular diseases). The potential of oxidative nucleic acid damage biomarkers for detection of diseases and drug development were described. Moreover, the approaches for detection of these biomarkers were also summarized.

Evaluation of Serum Trace Element Levels and Superoxide Dismutase Activity in Patients with Inflammatory Bowel Disease: Translating Basic Research into Clinical Application

The relationship of minerals and trace elements with inflammatory bowel disease (IBD) is complex. Alterations in their metabolism can be induced by the diseases and their complications. To study the role of trace elements in IBD patients' serum zinc and copper and their related enzymes, including superoxide dismutase (SOD), activity were measured in patients with IBD patients as well as in healthy subjects. In addition, the correlation between serum trace element levels, albumin, total protein, urea level, copper/zinc ratio, and disease activity (DA) was determined in these subjects. Serum samples were obtained from 35 patients (19 ulcerative colitis (UC) and 16 Crohn's disease (CD)) in the active phase of the disease and 30 healthy control subjects. Serum levels of zinc, copper, SOD activity, albumin, total protein, and urea were measured. The results were compared between the two groups using independent Student's t test in statistical analysis. Serum levels of zinc, SOD activity, albumin, and total protein were significantly lower (P < 0.05) in patients than controls, while serum urea level was significantly higher in patients compared to controls. Copper concentrations did not differ between patients with IBD (mean ± SD, 58.8 ± 20.7 μg/d) and controls (55.57 ± 12.6 μg/d). Decreased levels of zinc and SOD activity are associated with increased inflammatory processes indicating inappropriate antioxidant system in patients with IBD. Additionally, lower levels of albumin and total protein with higher level of urea reflect metabolic problems in liver system.

DNA Damage and Oxidative DNA Damage in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Inflammation has long been regarded as a major contributor to cellular oxidative damage and to be involved in the promotion of carcinogenesis.

METHODS

We aimed to investigate the oxidative damage in inflammatory bowel disease [IBD] patients through a case-control and prospective study involving 344 IBD patients and 294 healthy controls. DNA damage and oxidative DNA damage were measured by comet assay techniques, and oxidative stress by plasmatic lipid peroxidation, protein carbonyls, and total antioxidant capacity.

RESULTS

Higher DNA damage [p < 0.001] was found both in Crohn's disease [CD] (9.7 arbitrary units [AU]; interquartile range [IQR]: 6.2-14.0) and ulcerative colitis [UC] [7.1 AU; IQR: 4.4-11.7], when compared with controls [5.4 AU; IQR: 3.8-6.8], and this was also the case with oxidative DNA damage [p < 0.001] [CD: 3.6 AU; IQR: 1.8-6.8; UC: 4.6 AU; IQR: 2.4-8.1], when compared with controls: 2.3 AU; IQR: 1.2-4.2]. Stratifying patients into groups according to therapy (5-aminosalicylic acid [5-ASA], azathioprine, anti-TNF, and combined therapy [azathioprine and anti-TNF]) revealed significant between-group differences in the level of DNA damage, both in CD and UC, with the combined therapy exhibiting the highest DNA damage levels [11.6 AU; IQR: 9.5-14.3, and 12.4 AU; IQR: 10.6-15.0, respectively]. Among CD patients, disease behaviour [B1 and B2], and age at diagnosis over 40 years [A3] stand as risk factors for DNA damage. For UC patients, the risk factors found for DNA damage were disease activity, treatment, age at diagnosis under 40 years [A1 + A2] and disease locations [E2 and E3].

CONCLUSIONS

In IBD there is an increase in DNA damage, and treatment, age at diagnosis and inflammatory burden seem to be risk factors.

Susceptibility to Ulcerative Colitis and Genetic Polymorphisms of A251G SOD1 and C-262T CAT

BACKGROUND

Reactive oxygen species can attack and damage almost every molecule found in living cells, including proteins, carbohydrates, lipids, and DNA. For this reason, their production is normally tightly controlled. Among the most important defenses against these radicals are the superoxide dismutase (SOD) enzymes and catalase (CAT). Increasing attention has been given to the role of reactive oxygen metabolites in the pathogenesis of ulcerative colitis (UC), which is defined as an idiopathic and chronic intestinal inflammation. Accordingly, we hypothesized a relation between genetic polymorphisms in the two antioxidant enzymes SOD1 A251G (rs2070424) and CAT C-262T (rs1001179) and the risk of UC.

METHODS

The present case-control study included 109 UC patients (46 males and 50 females) and 186 (67 males and 119 females) gender-matched healthy controls. Genotyping was done by the PCR-RFLP method.

RESULTS

After adjusting for age and gender, a significant association was observed between the AG+GG genotypes of SOD1 A251G polymorphism (vs. AA genotype) and risk of UC (OR=0.29, 95% CI: 0.10-0.86, P= 0.025) after adjusting for age and gender. Our statistical analysis revealed that the CAT C-262T polymorphism did not associate with the risk of UC before and/or after adjusting for age and gender.

CONCLUSIONS

Based on the present statistical analysis, the G allele of the SOD1 A251G polymorphism decreases the risk of UC, thus it might be assumed that the G allele has a protective role.

Periodic Exposure of Keratinocytes to Cold Physical Plasma: An In Vitro Model for Redox-Related Diseases of the Skin

Oxidative stress illustrates an imbalance between radical formation and removal. Frequent redox stress is critically involved in many human pathologies including cancer, psoriasis, and chronic wounds. However, reactive species pursue a dual role being involved in signaling on the one hand and oxidative damage on the other. Using a HaCaT keratinocyte cell culture model, we investigated redox regulation and inflammation to periodic, low-dose oxidative stress after two, six, eight, ten, and twelve weeks. Chronic redox stress was generated by recurrent incubation with cold physical plasma-treated cell culture medium. Using transcriptome microarray technology, we identified both acute ROS-stress responses as well as numerous adaptions after several weeks of redox challenge. We determined a differential expression (2-fold, FDR < 0.01, p < 0.05) of 260 genes that function in inflammation and redox homeostasis, such as cytokines (e.g., IL-6, IL-8, and IL-10), growth factors (e.g., CSF2, FGF, and IGF-2), and antioxidant enzymes (e.g., HMOX, NQO1, GPX, and PRDX). Apoptotic signaling was affected rather modestly, especially in p53 downstream targets (e.g., BCL2, BBC3, and GADD45). Strikingly, the cell-protective heat shock protein HSP27 was strongly upregulated (p < 0.001). These results suggested cellular adaptions to frequent redox stress and may help to better understand the inflammatory responses in redox-related diseases.

Increased micronucleus, nucleoplasmic bridge, nuclear bud frequency and oxidative DNA damage associated with prolactin levels and pituitary adenoma diameters in patients with prolactinoma

Prolactinoma is the most common pituitary tumor. Most pituitary tumors are benign, but they often are clinically significant. We investigated cytokinesis-block micronucleus cytome (CBMN cyt) assay parameters and oxidative DNA damage in patients with prolactinoma to assess the relations among age, prolactin level, pituitary adenoma diameter and 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in patients with prolactinoma. We investigated 27 patients diagnosed with prolactinoma and 20 age- and sex-matched healthy controls. We measured CBMN cyt parameters and plasma 8-OHdG levels in peripheral blood lymphocytes of patients with prolactinoma and controls. The frequencies of micronucleus (MN), nucleoplasmic bridge, nuclear bud, apoptotic and necrotic cells, and plasma 8-OHdG levels in patients with prolactinoma were significantly greater than controls. MN frequency was correlated positively with age, prolactin levels and pituitary adenoma diameters in patients with prolactinoma. The increased chromosomal and oxidative DNA damage, and the positive correlation between MN frequency, prolactin levels and pituitary adenoma diameters may be associated with increased risk of cancer in patients with prolactinoma, because increased MN frequency is a predictor of cancer risk.

Possible Biomarkers in Blood for Crohn's Disease: Oxidative Stress and MicroRNAs-Current Evidences and Further Aspects to Unravel

Crohn's disease (CD) is an inflammatory disorder characterised by a transmural inflammation of the intestinal wall. Although the physiopathology of the disease is not yet fully understood, it is clear that the immune response plays an important role in it. This hyperreactive immune system is accompanied by the presence of unregulated reactive oxygen species (ROS). These elements are modulated in normal conditions by different elements, including enzymes that function as antioxidant defences preventing the harmful effects of ROS. However, in CD there is an imbalance between ROS production and these antioxidant elements, resulting in oxidative stress (OxS) phenomena. In fact, now OxS is being considered more a potential etiological factor for Crohn's disease rather than a concomitant effect in the disease. The persistence of the OxS can also be influencing the evolution of the disease. Furthermore, the epigenetic mechanisms, above all microRNAs, are being considered key elements in the pathogenesis of CD. These elements and the presence of OxS have also been linked to several diseases. We, therefore, describe in this review the most significant findings related to oxidative stress and microRNAs profiles in the peripheral blood of CD patients.

Oxidative Stress and DNA Damage: Implications in Inflammatory Bowel Disease

This review will focus on published human studies on oxidative stress and DNA damage in inflammatory bowel disease (IBD), both ulcerative colitis and Crohn's disease, assessing their role in the pathophysiology of these diseases. Search was performed over PubMed and ScienceDirect databases to identify relevant bibliography, using keywords including "oxidative stress," "DNA damage," "IBD," and "oxidative DNA damage." Whether as cause or effect, mechanisms underlying oxidative stress have the potential to condition the course of various pathologies, particularly those driven by inflammatory scenarios. IBDs are chronic inflammatory relapsing conditions. Oxidative stress has been associated with some of the characteristic clinical features exhibited in IBD, namely tissue injury and fibrosis, and also to the ulcerative colitis-associated colorectal cancer. The possible influence of oxidative stress over therapeutic behavior and response, as well as their contribution to the oxidative burden and consequences, is also addressed. Due to the high prevalence and incidence of IBD worldwide, and also to its associated morbidity, complications, and disease and treatment costs, it is of paramount importance to better understand the pathophysiology of these diseases.

Mitochondrial dysfunction in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) represents a group of idiopathic disorders characterized by chronic or recurring inflammation of the gastrointestinal tract. While the exact etiology of disease is unknown, IBD is recognized to be a complex, multifactorial disease that results from an intricate interplay of genetic predisposition, an altered immune response, changes in the intestinal microbiota, and environmental factors. Together, these contribute to a destruction of the intestinal epithelial barrier, increased gut permeability, and an influx of immune cells. Given that most cellular functions as well as maintenance of the epithelial barrier is energy-dependent, it is logical to assume that mitochondrial dysfunction may play a key role in both the onset and recurrence of disease. Indeed several studies have demonstrated evidence of mitochondrial stress and alterations in mitochondrial function within the intestinal epithelium of patients with IBD and mice undergoing experimental colitis. Although the hallmarks of mitochondrial dysfunction, including oxidative stress and impaired ATP production are known to be evident in the intestines of patients with IBD, it is as yet unclear whether these processes occur as a cause of consequence of disease. We provide a current review of mitochondrial function in the setting of intestinal inflammation during IBD.

Immunohistochemical expression of 8-oxo-7,8-dihydro-2'-deoxyguanosine in cytoplasm of tumour and adjacent normal mucosa cells in patients with colorectal cancer

BACKGROUND

The aim of this research was to study the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in tumour tissue samples of colorectal carcinoma based upon immunohistochemical detection and compare those results with patients' outcome.

METHODS

Tumour blocks of patients surgically treated for colorectal cancer were evaluated by 8-oxodG immunohistochemical staining. The expression was analysed in 500 tumour cells. The percentage of positive cells, as well as staining intensity, was recorded, and Allred score was calculated. For each patient, data of age, gender, tumour size and location, margin status, histologic grade, tumour stage, lymph node status, vascular invasion, overall survival, and therapy protocols were collected. Tumour grade was divided into two groups as low and high grade.

RESULTS

In this study, 146 consecutive patients with primary colorectal carcinoma were included. All data were available for 138 patients, and they were included in this research. There were 83 male and 55 female patients; the median age was 64 years (range 35-87 years). The results showed shorter 5- and 10-year survival in patients with 8-oxodG positive tumour cells (5-year survival, n=138, Mantel-Cox, chi-square 4.116, degree of freedom (df)=1, p<0.05; 10-year survival, n=134, Mantel-Cox, chi-square 4.374, df=1, p<0.05). The results showed a positive correlation between Allred score and high tumour grade (two-tailed Spearman's ρ 0.184; p<0.05), as well as with non-polypoid tumour growth (two-tailed Spearman's ρ 0.198; p<0.05). There was no significant difference of 8-oxodG expression related to age, sex, blood group, size and tumour site, distance from the edge of the resected tumour margin, lymph nodes involvement, and vascular invasion.

CONCLUSIONS

In this study, the positive correlation between 8-oxodG presence in the tumour cells, worse clinical outcome, higher tumour grade, and flat morphology was found.

The Sasa quelpaertensis Leaf Extract Inhibits the Dextran Sulfate Sodium-induced Mouse Colitis Through Modulation of Antioxidant Enzyme Expression

Background:

Oxidative stress plays an important role in the pathogenesis of inflammatory bowel disease. The objective of this study is to investigate the protective effect of Sasa quelpaertensis leaf extract (SQE) against oxidative stress in mice with dextran sulfate sodium (DSS)-induced colitis.

Methods:

Mice were treated with SQE (100 mg/kg or 300 mg/kg body weight) by gavage in advance two weeks before inflammation was induced. Then, the mice were administered with 2.5% DSS in drinking water for 7 days and normal drinking water for 7 days between two DSS treatment. Disease activity index values, gut motility, and severity of the resulting oxidative DNA damage were analyzed. The antioxidant effect of SQE was evaluated by measuring malondialdehyde (MDA) and superoxide dismutase (SOD) activity in plasma samples. Catalase activity and expressions levels of glutathione peroxidase 1 (Gpx1), SOD1, and SOD2 were also detected in colon tissues.

Results:

Administration of SQE significantly reduced the severity of DSS-induced colitis compared to the control (Ctrl) group. Levels of 8-oxo-dG, an oxidative DNA damage marker, were significantly lower in the SQE group compared to the untreated DSS Ctrl group. In the SQE (300 mg/kg) group, MDA levels were significantly lower, while SOD and catalase activity levels in the plasma samples were significantly higher compared with the DSS Ctrl group. The expression levels of the antioxidant enzymes, SOD2 and Gpx1, were significantly higher, while the levels of SOD 1 expression were lower, in the colon tissues of the DSS Ctrl group compared with those of the Ctrl group. In contrast, administration of SQE significantly down-regulated SOD2 and Gpx1 expressions and up-regulated SOD1 expression.

Conclusions:

These results indicate that SQE efficiently suppresses oxidative stress in DSS-induced colitis in mice, and its action is associated with the regulation of antioxidant enzymes.

Selenoprotein P influences colitis-induced tumorigenesis by mediating stemness and oxidative damage

Patients with inflammatory bowel disease are at increased risk for colon cancer due to augmented oxidative stress. These patients also have compromised antioxidant defenses as the result of nutritional deficiencies. The micronutrient selenium is essential for selenoprotein production and is transported from the liver to target tissues via selenoprotein P (SEPP1). Target tissues also produce SEPP1, which is thought to possess an endogenous antioxidant function. Here, we have shown that mice with Sepp1 haploinsufficiency or mutations that disrupt either the selenium transport or the enzymatic domain of SEPP1 exhibit increased colitis-associated carcinogenesis as the result of increased genomic instability and promotion of a protumorigenic microenvironment. Reduced SEPP1 function markedly increased M2-polarized macrophages, indicating a role for SEPP1 in macrophage polarization and immune function. Furthermore, compared with partial loss, complete loss of SEPP1 substantially reduced tumor burden, in part due to increased apoptosis. Using intestinal organoid cultures, we found that, compared with those from WT animals, Sepp1-null cultures display increased stem cell characteristics that are coupled with increased ROS production, DNA damage, proliferation, decreased cell survival, and modulation of WNT signaling in response to H2O2-mediated oxidative stress. Together, these data demonstrate that SEPP1 influences inflammatory tumorigenesis by affecting genomic stability, the inflammatory microenvironment, and epithelial stem cell functions.

Inflammatory and redox reactions in colorectal carcinogenesis

It has been established that there is a relationship between chronic inflammation and cancer development. The constant colonic inflammation typical of inflammatory bowel diseases is now considered a risk factor for colorectal carcinoma (CRC) development. The inflammatory network of signaling molecules is also required during the late phases of carcinogenesis, to enable cancer cells to survive and to metastasize. Oxidative reactions are an integral part of the inflammatory response, and are generally associated with CRC development. However, when the malignant phenotype is acquired, increased oxidative status induces antioxidant defenses in cancer cells, favoring their aggressiveness. This contradictory behavior of cancer cells toward redox status is of great significance for potential anticancer therapies. This paper summarizes the essential background information relating to the molecules involved in regulating oxidative stress and inflammation during carcinogenesis. Understanding more of their function in CRC stages might provide the foundation for future developments in CRC treatment.

DNA damage in children with obstructive adenotonsillar hypertrophy

The objective of this prospective, controlled study was to evaluate oxidative DNA damage in children with obstructive adenotonsillar hypertrophy. This study included 30 patients with obstructive adenotonsillar hypertrophy (male/female ratio, 3:2; age range, 3-9 y) scheduled to undergo tonsillectomy and adenoidectomy and 25 control subjects of similar age and sex with no adenotonsillar disease or airway obstruction. Urine and blood samples were obtained from each child for 8-hydroxy 2-deoxyguanosine (8-OhdG) and malondialdehyde (MDA) concentrations. There were significant differences in leukocyte (3.28 [0.69/10] vs 0.70 [0.15/10] dG) and urine 8-OhdG (8.22 [2.27/10] vs 5.26 [1.3/10] dG) levels in patients with obstructive adenotonsillar hypertrophy and healthy subjects (P < 0.001 for both). Plasma (2.98 [1.31] vs 1.14 [0.64] μM) and urine (1.77 [0.84] vs 0.56 [0.32] μM) MDA levels were also different (P < 0.001 for both). There were positive correlations between 8-OhdG in leukocyte DNA and plasma MDA (r = 0.648, P < 0.001) and between levels of urine 8-OhdG excretion and urine MDA (r = 0.588, P < 0.001). The DNA damage in children with adenotonsillar hypertrophy should be kept in mind, but further studies must be done with larger patient groups.

Implications of the colonic deposition of free hemoglobin-α chain: a previously unknown tissue by-product in inflammatory bowel disease

BACKGROUND

We analyzed inflamed mucosal/submucosal layers of ulcerative colitis (UC = 63) and Crohn's colitis (CC = 50), and unexpectedly, we unveiled a pool of free hemoglobin alpha (Hb-α) chain. Patients with colitides have increased reactive oxidative stress (ROS), DNA oxidation products, free iron in mucosa, in preneoplastic, and in colitis-cancers and increased risks of developing colorectal cancer. All inflammatory bowel disease-related colorectal cancer lesions are found in segments with colitis. Linking this information, we investigated whether free Hb-α is key transformational stepping that increases colitis-related colorectal cancer vulnerability.

METHODS

UC/CC samples were profiled using matrix-assisted laser desorption/ionization mass spectrometry; protein identification was made by liquid chromatography. Diverticulitis was used as control (Ctrl). The presence of Hb(n) (n = α, β, or hemin)/Hb was validated by Western blotting and immunohistochemistry. We tested for DNA damage (DNAD) by exposing normal colonic epithelial cell line, NCM460, to 10 μM and 100 μM of Hb(n)/Hb, individually for 2, 6, and 12 hours. Quantification of Hb-α staining was done by Nikon Elements Advance Research Analysis software. ROS was measured by the production of 8-OHdG. DNAD was assessed by Comet assay. Colonic tissue homogenate antioxidants Nrf2-, CAT-, SOD-, and GPx-expressions were analyzed densitometrically/normalized by β-actin.

RESULTS

Immunohistochemistry of CC/UC mucosal/submucosal compartments stained strongly positive for Hb-α and significantly higher versus Ctrl. NCM460 exposed to Hb(n)/Hb exhibited steadily increasing ROS and subsequent DNAD. DNAD was higher in 10 μM than 100 μM in Hb-β/hemin the first 2 hours then plateaued followed by DNAD repair. This may be likely due to apoptosis in the later concentration. Nrf2 enzyme activities among UC, CC, and ulcerative colitis-associated colon cancer (UCAC) were observed impaired in all inflammatory bowel disease subjects. Decreased levels of Nrf2 among patients with UC versus patients with CC with active disease were insignificant as well as versus Ctrls but significantly lower in UCAC versus Ctrl. SOD was decreased in UC and UCAC and GPx in CC but statistically not significant. Comparing CC versus UC, SOD was significantly lower in CC (P < 0.05). CAT was observed increased among patients with CC/UC/UCAC and GPx in UC and UCAC versus Ctrl, respectively, and significantly increased in CC versus Ctrl (P < 0.01).

CONCLUSIONS

In the colitides, mucosal/submucosal tissue microenvironments demonstrated pool of free Hb-α chain. In vitro exposure of NCM460 cells to Hb(n)/Hb induced ROS and DNAD. Toxic effect of free Hb-α, in colonic epithelial cells, is therefore through production of ROS formation modulated by impairment of antioxidant effects. Targeting reduction-oxidation-sensitive pathways and transcription factors may offer options for inflammatory bowel disease-management and colitis-related cancer prevention.

Increased genome instability and oxidative DNA damage and their association with IGF-1 levels in patients with active acromegaly

OBJECTIVE

The objectives of this study were to assess cytokinesis-block micronucleus cytome (CBMN Cyt) assay parameters and also oxidative DNA damage in patients with active acromegaly and controls and to assess the relationship between age, serum insulin-like growth factor 1 (IGF-1) levels, pituitary adenoma diameters, 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and CBMN Cyt assay parameters in patients with active acromegaly.

DESIGN

The study population included 30 patients with active acromegaly and 30 age- and sex-matched healthy controls. CBMN Cyt assay parameters in peripheral blood lymphocytes of patients with active acromegaly and controls were evaluated and plasma 8-OHdG levels were measured.

RESULTS

Frequencies of micronucleus (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in lymphocytes of patients with acromegaly were found to be significantly higher than those in controls (p<0.001, p<0.001, p<0.001, respectively). The frequencies of apoptotic and necrotic cells in lymphocytes of patients with acromegaly were found to be significantly higher than those in controls (p<0.001 and p<0.001 respectively). No statistically significant differences in the number of cells in metaphase, the number of bi-nucleated cells (M2), the number of tri-nucleated cells (M3), the number of tetra-nucleated cells (M4) and nuclear division index (NDI) values were observed between patients and controls (p>0.05). Plasma 8-OHdG (ng/ml) levels in patients with acromegaly were found to be significantly higher than those in controls (p<0.005). MN frequency in the lymphocytes of patients with acromegaly increased with elevated serum IGF-1 levels (p<0.05), whereas the number of NPBs and the frequency of apoptotic cells decreased with elevated serum IGF-1 levels (p<0.01 and p<0.05 respectively).

CONCLUSIONS

Both the increase in chromosomal/oxidative DNA damage and the positive association between MN frequency and serum IGF-1 levels may predict an increased risk of malignancy in acromegalic patients. Long-term follow-up of patients with acromegaly will be necessary to establish the degree of cancer risk in this population.

Inflammatory bowel disease: mechanisms, redox considerations, and therapeutic targets

Oxidative stress is thought to play a key role in the development of intestinal damage in inflammatory bowel disease (IBD), because of its primary involvement in intestinal cells' aberrant immune and inflammatory responses to dietary antigens and to the commensal bacteria. During the active disease phase, activated leukocytes generate not only a wide spectrum of pro-inflammatory cytokines, but also excess oxidative reactions, which markedly alter the redox equilibrium within the gut mucosa, and maintain inflammation by inducing redox-sensitive signaling pathways and transcription factors. Moreover, several inflammatory molecules generate further oxidation products, leading to a self-sustaining and auto-amplifying vicious circle, which eventually impairs the gut barrier. The current treatment of IBD consists of long-term conventional anti-inflammatory therapy and often leads to drug refractoriness or intolerance, limiting patients' quality of life. Immune modulators or anti-tumor necrosis factor α antibodies have recently been used, but all carry the risk of significant side effects and a poor treatment response. Recent developments in molecular medicine point to the possibility of treating the oxidative stress associated with IBD, by designing a proper supplementation of specific lipids to induce local production of anti-inflammatory derivatives, as well as by developing biological therapies that target selective molecules (i.e., nuclear factor-κB, NADPH oxidase, prohibitins, or inflammasomes) involved in redox signaling. The clinical significance of oxidative stress in IBD is now becoming clear, and may soon lead to important new therapeutic options to lessen intestinal damage in this disease.

Accumulation of promutagenic DNA adducts in the mouse distal colon after consumption of heme does not induce colonic neoplasms in the western diet model of spontaneous colorectal cancer

SCOPE

Red meat is considered a risk factor for colorectal cancer (CRC). Heme is considered to promote colonic hyperproliferation and cell damage. Resistant starch (RS) is a food that ferments in the colon with studies demonstrating protective effects against CRC. By utilizing the western diet model of spontaneous CRC, we determined if feeding heme (as hemin chloride) equivalent to a high red meat diet would increase colonic DNA adducts and CRC and whether RS could abrogate such effects.

METHODS AND RESULTS

Four groups of mice: control, heme, RS and heme + RS were fed diets for 1 or 18 months. Colons were analyzed for apoptosis, proliferation, DNA adducts "8-hydroxy-2-deoxyguanosine" and "O(6) -methyl-2-deoxyguanosine" (O(6) MeG), and neoplasms. In the short term, heme increased cell proliferation (p < 0.05). Changes from 1 to 18 months showed increased cell proliferation (p < 0.01) and 8-hydroxy-2-deoxyguanosine adducts (p < 0.05) in all groups, but only heme-fed mice showed reduced apoptosis (p < 0.01) and increased O(6) MeG adducts (p < 0.01). The incidence of colon neoplasms was not different between any interventions.

CONCLUSION

We identified heme to increase proliferation in the short term, inhibit apoptosis over the long term, and increase O(6) MeG adducts in the colon over time although these changes did not affect colonic neoplasms within this mouse model.