Catalase inhibition can modulate the ability of peripheral blood T cells to undergo apoptosis in Crohn's disease.

Crohn's disease (CD) is a chronic relapsing inflammatory disorder in which defective apoptosis of mucosal T cells is postulated to produce sustained inflammation and reactive oxygen species accumulation. Whether CD T cells are intrinsically resistant to apoptosis or whether this resistance is acquired at the intestinal site needs to be clarified, as the cellular mechanisms modulate the impaired apoptosis in these cells. Here, we analysed peripheral blood T cells from patients naïve to specific CD treatment at the onset and from healthy controls. Non-activated freshly purified lymphocytes were cultured and submitted to in vitro protocols for activation (CD3/CD28 antibodies) and apoptosis (Fas antibody). Cells were analysed by flow cytometry. Caspases (3, 8, and 9) and catalase activity were measured; protein levels of bax, Bcl-2, and NF-kB were detected by western blotting, and cytokines by Luminex-based assays. The results showed that CD4 T cells from CD patients are less prone to apoptosis before they can migrate to the intestinal mucosa. Caspase-9, FasR, sIL-2Rα, IL-17A, IFNγ, IL-6, TNF-α, and IL-10 were shown to be significantly different in CD but not for the rest of the analysed biological elements. Catalase activity was significantly reduced in CD T cells, which was confirmed in ex vivo experiments in which catalase inhibition in T cells from healthy controls triggered apoptosis inhibition in a dose-dependent manner. In conclusion, apoptosis inhibition of CD T cells is a feature of these cells before they can migrate to the intestinal mucosa. Noteworthy, the impaired apoptosis of T cells can be directly influenced by catalase inhibition.

Different Genetic Expression Profiles of Oxidative Stress and Apoptosis-Related Genes in Crohn's Disease.

BACKGROUND/AIMS: Increased oxidative stress and decreased immune cell apoptosis have been reported to be important factors in the pathogenesis of Crohn's disease (CD). Our aim was to characterize the genetic expression of molecules implicated in the regulation of oxidative stress and apoptosis in peripheral white mononuclear cells of 18 healthy volunteers (controls) and 20 patients at the onset of CD (active CD [aCD]): 10 who achieved remission (inactive CD [iCD]) and 10 who did not present a complete and deep response to treatment (aCD-T). METHODS: mRNA expression was measured by the Agena MassARRAY quantitative gene expression analysis application. The genes analyzed were Fas-receptor (FASR), Fas-ligand (FASL), signal transducer and activator of transcription 1 (STAT1), nuclear factor kappa-light-chain--enhancer of activated B cells (NFKB1), apoptosis signal-regulating kinase 1 (ASK1), serine/threonine-protein kinase H1 (PSKH1), ATP-binding cassette sub-family B1 (ABCB1) and peptidylprolyl isomerase D (PPID). RESULTS: During a CD flare, we found specific upregulated expression of the genes STAT1 and PSKH1, whereas ABCB1 and FASL were downregulated. In the patients with iCD, FASR and NFKB1 were upregulated. The expression levels of NFKB1, STAT1 and ABCB1 did not show any difference in patients with aCD at the onset of the disease and after treatment (aCD-T). The expression levels of PPID and ASK1 did not show any differences in the patients with aCD, iCD and the controls. We have also reviewed the cellular function and role of these genes in CD. CONCLUSIONS: These findings contribute to improving the understanding of the pathogenesis of CD and highlight potential genes involved.

Estrés oxidativo en la enfermedad de Crohn / Oxidative stress in Crohn's disease

La enfermedad de Crohn (EC) se caracteriza por dar lugar a procesos de inflamación transmural que con mayor frecuencia se localizan en la región del íleon terminal. Aunque los mecanismos fisiopatológicos de la enfermedad no están todavía bien definidos, se ha observado que la respuesta inmunitaria no regulada está asociada a una producción elevada de especies reactivas de oxígeno (ERO). Estos elementos están relacionados con unos sistemas complejos denominados defensas antioxidantes (DAO) que tienen la función de regular los ERO, evitando así sus efectos dañinos. Sin embargo, se ha descrito ampliamente para la EC la presencia de un desequilibrio entre la producción de ERO y su eliminación por los elementos antioxidantes, originando lo que se denomina estrés oxidativo. Enmarcado en este contexto, a continuación se profundiza sobre los hallazgos más destacados relacionados con el estrés oxidativo en la mucosa intestinal y en la sangre periférica (AU)

Crohn’s disease (CD) is characterized by transmural inflammation that is most frequently located in the region of the terminal ileum. Although the physiopathological mechanisms of the disease are not yet well defined, the unregulated immune response is associated with high production of reactive oxygen species (ROS). These elements are associated with complex systems known as antioxidant defenses, whose function is ROS regulation, thereby preventing the harmful effects of these elements. However, the presence of an imbalance between ROS production and ROS elimination by antioxidants has been widely described and leads to oxidative stress. In this article, we describe the most significant findings on oxidative stress in the intestinal mucosa and peripheral blood

[Oxidative stress in Crohn's disease]. / Estrés oxidativo en la enfermedad de Crohn.

Crohn's disease (CD) is characterized by transmural inflammation that is most frequently located in the region of the terminal ileum. Although the physiopathological mechanisms of the disease are not yet well defined, the unregulated immune response is associated with high production of reactive oxygen species (ROS). These elements are associated with complex systems known as antioxidant defenses, whose function is ROS regulation, thereby preventing the harmful effects of these elements. However, the presence of an imbalance between ROS production and ROS elimination by antioxidants has been widely described and leads to oxidative stress. In this article, we describe the most significant findings on oxidative stress in the intestinal mucosa and peripheral blood.

Role of oxidative stress and antioxidant enzymes in Crohn's disease.

There is increasing interest in oxidative stress being a potential aetiological factor and/or a triggering factor in Crohn's disease, rather than a concomitant occurrence during the pathogenesis of the disease. Recent research has shown that the immune mononuclear cells of Crohn's disease patients are induced to produce hydrogen peroxide (H2O2). Similarly, the regulation of antioxidant enzymes during disease in these cells has been unravelled, showing that SOD (superoxide dismutase) activity and GPx (glutathione peroxidase) activity is increased during active disease and returns to normal in remission phases. However, catalase remains constantly inhibited which supports the idea that catalase is not a redox-sensitive enzyme, but a regulator of cellular processes. ROS (reactive oxygen species) can be produced under the stimulus of different cytokines such as TNFα (tumour necrosis factor α). It has been shown in different experimental models that they are also able to regulate apoptosis and other cellular processes. The status of oxidative stress elements in Crohn's disease and their possible implications in regulating cellular processes are reviewed in the present paper.

Delayed fatherhood in mice decreases reproductive fitness and longevity of offspring.

This study aims to analyze, in mice, the long-term effects of delayed fatherhood on reproductive fitness and longevity of offspring. Hybrid parental-generation (F(0)) males, at the age of 12, 70, 100, and 120 wk, were individually housed with a randomly selected 12-wk-old hybrid female. The reproductive fitness of first-generation (F(1)) females was tested from the age of 25 wk until the end of their reproductive life. In F(1) males, the testing period ranged from the age of 52 wk until death. Breeding F(1) females from the 120-wk group displayed interbirth intervals longer than females from the 12-, 70-, and 100-wk groups. Furthermore, F(2) pups begotten by F(1) studs exhibited weaning weights lower than pups from the 12- and 70-wk groups. Offspring from the 120-wk group exhibited shorter survival times associated with lower incidence of tumorigenesis and higher loss of body weight when approaching death when compared to F(1) offspring from younger age-groups. The results indicate that advanced paternal age at conception has negative long-term effects on reproductive fitness and longevity of offspring in the mouse model.

Long-term effects of delayed fatherhood in mice on postnatal development and behavioral traits of offspring.

This study aims to analyze, in mice, the long-term effects of delayed fatherhood on postnatal development, spontaneous motor activity, and learning capacity of offspring. Hybrid parental-generation (F(0)) males, at the age of 12, 70, 100, and 120 wk, were individually housed with a randomly selected 12-wk-old hybrid female. The resulting first-generation (F(1)) offspring were tested for several developmental and behavioral variables. Cumulative percentage of F(1) pups that attained immediate righting in the 120-wk group was lower than that found in the 12-, 70-, and 100-wk groups. Furthermore, the postnatal day of attaining immediate righting was higher in pups from the 120-wk group when compared to pups from the other age-groups. At the age of 20 wk, F(1) offspring from the 120-wk group displayed lower counts of motor activity than offspring from the 12-, 70-, and 100-wk groups. One week later, a higher percentage of offspring from the 100- and 120-wk groups entered the dark compartment during the retention trial of the passive-avoidance test when compared to offspring from the 12-wk group. Offspring from the 120-wk group exhibited also lower step-through latency in the retention trial than offspring from the 12-, 70-, and 100-wk groups. These results show that advanced paternal age at conception has long-term effects on preweaning development, spontaneous motor activity, and reduced passive-avoidance learning capacity of mouse offspring.

Beneficial effects of dithiothreitol on relative levels of glutathione S-transferase activity and thiols in oocytes, and cell number, DNA fragmentation and allocation at the blastocyst stage in the mouse.

We analyzed the effect of in vitro aging of mouse oocytes in the presence of dithiothreitol (DTT) on relative levels of glutathione S-transferase (GST) activity and thiols in oocytes, and cell number, DNA fragmentation and cellular allocation to the inner cell mass (ICM) and trophectoderm (TE) lineage at the blastocyst stage. Ovulated oocytes from gonadotropin primed hybrid female mice of 6-8 weeks of age were aged in vitro in the presence of 0, 5, 50, or 500 microM DTT for 6 hr prior to insemination. Relative levels of GST activity and thiols in oocytes were determined by confocal laser scanning microscopy, DNA fragmentation using a single-step TUNEL method, and cell allocation to the ICM and TE lineage by blastocyst staining with propidium iodide and Hoechst 33258. Non-aged oocytes exhibited higher relative levels of GST activity and thiols when compared to oocytes aged in the presence of 0, 5, and 50 microM DTT. Day 5 blastocysts from the 5, 50, and 500 microM DTT groups exhibited higher total number of cells, number of ICM cells, and ICM/TE ratio, but lower percentage of number of nuclei with DNA fragmentation/number of ICM cells than blastocyst from the 0 microM DTT group. These data show that DTT counteracts the negative effects of a post-ovulatory aging of mouse oocytes in vitro on relative levels of GST activity and thiols in oocytes, and percentage of number of nuclei with DNA fragmentation/number of ICM cells, total number of cells, number of ICM cells and ICM/TE ratio in Day 5 blastocysts.

Delayed motherhood decreases life expectancy of mouse offspring.

This study analyzes the long-term effects of delayed motherhood on reproductive fitness and life expectancy of offspring in the mouse. Hybrid (C57BL/6JIco x CBA/JIco) first-generation (F1) females, either at the age of 10 or 51 wk, were individually housed with a randomly selected 12- to 14-wk-old hybrid male following a breeding pen system until females reached the end of their reproductive life. Reproductive fitness of second-generation (F2) females was tested from the age of 25 wk until the end of their reproductive life. In F2 males, the testing period ranged from the age of 52 wk until their natural death. Delayed motherhood of hybrid F1 female mice was associated with a decreased percentage of male F3 offspring at birth and lower life expectancy and body weight during adulthood of F2 offspring. There was, however, no evident negative effect of delayed motherhood on several reproductive fitness variables in either male or female F2 offspring. This included between-parturition interval, litter size at birth and at weaning, body weight at weaning and preweaning mortality of F3 pups, percentage of F3 litters with at least one pup cannibalized, and time at which female and male F2 offspring ceased their reproductive life. These data clearly show that delayed motherhood in the mouse is associated with negative long-term effects on offspring survival.