Endocytosis and Recycling of Tight Junction Proteins in Inflammation

A critical function of the epithelial lining is to form a barrier that separates luminal contents from the underlying interstitium. This barrier function is primarily regulated by the apical junctional complex (AJC) consisting of tight junctions (TJs) and adherens junctions (AJs) and is compromised under inflammatory conditions. In intestinal epithelial cells, proinflammatory cytokines, for example, interferon-gamma (IFN-γ), induce internalization of TJ proteins by endocytosis. Endocytosed TJ proteins are passed into early and recycling endosomes, suggesting the involvement of recycling of internalized TJ proteins. This review summarizes mechanisms by which TJ proteins under inflammatory conditions are internalized in intestinal epithelial cells and point out comparable mechanism in nonintestinal epithelial cells

Single-Port Laparoscopic Surgery for Inflammatory Bowel Disease

Background. Single Port Laparoscopic Surgery (SPLS) is being increasingly employed in colorectal surgery for benign and malignant diseases. The particular role for SPLS in inflammatory bowel disease (IBD) has not been determined yet. In this review article we summarize technical aspects and short term results of SPLS resections in patients with Crohn's disease or ulcerative colitis. Methods. A systematic review of the literature until January 2012 was performed. Publications were assessed for operative techniques, equipment, surgical results, hospital stay, and readmissions. Results. 34 articles, published between 2010 and 2012, were identified reporting on 301 patients with IBD that underwent surgical treatment in SPLS technique. Surgical procedures included ileocolic resections, sigmoid resections, colectomies with end ileostomy or ileorectal anastomosis, and restorative proctocolectomies with ileum-pouch reconstruction. There was a wide variety in the surgical technique and the employed equipment. The overall complication profile was similar to reports on standard laparoscopic surgery in IBD. Conclusions. In experienced hands, single port laparoscopic surgery appears to be feasible and safe for the surgical treatment of selected patients with IBD. However, evidence from prospective randomized trials is required in order to clarify whether there is a further benefit apart from the avoidance of additional trocar incisions

Der Endothelin-Rezeptorantagonist Bosentan reduziert die Leukozyten-Endothel-Interaktion und die Aktivität chronisch entzündlicher Darmerkrankungen:eine tierexperimentelle intravitalmikroskopische Studie

Einleitung: Die Wirkung des Endothelin-Rezeptor-Antagonisten Bosentan auf die Leukozyten-Endothel-Interaktion und die Entzündungsaktivität einer Dextran-Sodium-Sulphate (DSS) induzierten Colitis der Maus wurde untersucht. Methoden: Balb/c Mäuse wurden in 3 Gruppen (n=10) eingeteilt: gesunde Kontrolle, Colitis (DSS zyklisch oral für 30 Tage), Colitis + Therapie mit Bosentan intraperitoneal täglich an Tag 26-30. An Tag 30 wurde die histologische und klinische Entzündungsaktivität sowie intravitalmikroskopisch die Leukozytenadhäsion in Colon-Venolen untersucht. Ergebnisse: Die Colitis-Induktion führte zu einer hohen Zahl rollender und adhärenter Leukozyten. Die Therapie mit Bosentan senkte die Zahl adhärenter, nicht aber rollender Leukozyten, erhöhte die Leukozyten-Rollgeschwindigkeit, und senkte die klinische und histologische Entzündungsaktivität. Schlussfolgerung: Durch Reduktion der Leukozytenadhäsion könnte Bosentan bei chronisch entzündlichen Darmerkrankungen therapeutisch wirken.Introduction: The effect of Bosentan, an endothelin receptor antagonist, on endothelial leukocyte adhesion and on inflammation was studied in a dextran sodium sulphate induced murine colitis. Methods: Balb/c mice were divided into 3 groups (n=10): healthy control, colitis (cyclic oral application of DSS for 30 days), colitis + therapy with Bosentan intraperitoneally daily on days 26-30. On day 30 clinical and histological inflammation were examined, and leukocyte adhesion in colonic venules was assessed by in vivo microscopy. Results: Induction of colitis led to high numbers of rolling and firmly adherent leukocytes. Bosentan therapy reduced the number of adherent, but not rolling leukocytes, increased leukocyte rolling velocity, and reduced clinical and histological inflammation. Conclusion: By reducing leukocyte adhesion Bosentan could be a therapeutic option in inflammatory bowel disease

Developmental fluoxetine exposure in zebrafish reduces offspring basal cortisol concentration via life stage-dependent maternal transmission

Fluoxetine (FLX) is a pharmaceutical used to treat affective disorders in humans, but as environmental contaminant also affects inadvertently exposed fish in urban watersheds. In humans and fish, acute FLX treatment and exposure are linked to endocrine disruption, including effects on the reproductive and stress axes. Using the zebrafish model, we build on the recent finding that developmental FLX exposure reduced cortisol production across generations, to determine possible parental and/or life-stage-dependent (age and/or breeding experience) contributions to this phenotype. Specifically, we combined control and developmentally FLX-exposed animals of both sexes (F0) into four distinct breeding groups mated at 5 and 9 months, and measured offspring (F1) basal cortisol at 12 dpf. Basal cortisol was lower in F1 descended from developmentally FLX-exposed F0 females bred at 5, but not 9 months, revealing a maternal, life-stage dependent effect. To investigate potential molecular contributions to this phenotype, we profiled maternally deposited transcripts involved in endocrine stress axis development and regulation, epigenetic (de novo DNA methyltransferases) and post-transcriptional (miRNA pathway components and specific miRNAs) regulation of gene expression in unfertilized eggs. Maternal FLX exposure resulted in decreased transcript abundance of glucocorticoid receptor, dnmt3 paralogues and miRNA pathway components in eggs collected at 5 months, and increased transcript abundance of miRNA pathway components at 9 months. Specific miRNAs predicted to target stress axis transcripts decreased (miR-740) or increased (miR-26, miR-30d, miR-92a, miR-103) in eggs collected from FLX females at 5 months. Increased abundance of miRNA-30d and miRNA-92a persisted in eggs collected from FLX females at 9 months. Clustering and principal component analyses of egg transcript profiles separated eggs collected from FLX-females at 5 months from other groups, suggesting that oocyte molecular signatures, and miRNAs in particular, may serve as predictive tools for the offspring phenotype of reduced basal cortisol in response to maternal FLX exposure

Temporary Fecal Diversion in the Management of Colorectal and Perianal Crohn’s Disease

Aim. To evaluate the results of temporary fecal diversion in colorectal and perianal Crohn’s disease. Method. We retrospectively identified 29 consecutive patients (14 females, 15 males; median age: 30.0 years, range: 18–76) undergoing temporary fecal diversion for colorectal (n=14), ileal (n=4), and/or perianal Crohn’s disease (n=22). Follow-up was in median 33.0 (3–103) months. Response to fecal diversion, rate of stoma reversal, and relapse rate after stoma reversal were recorded. Results. The response to temporary fecal diversion was complete remission in 4/29 (13.8%), partial remission in 12/29 (41.4%), no change in 7/29 (24.1%), and progress in 6/29 (20.7%). Stoma reversal was performed in 19 out of 25 patients (76%) available for follow-up. Of these, the majority (15/19, 78.9%) needed further surgical therapies for a relapse of the same pathology previously leading to temporary fecal diversion, including colorectal resections (10/19, 52.6%) and creation of a definitive stoma (7/19, 36.8%). At the end of follow-up, only 4/25 patients (16%) had a stable course without the need for further definitive surgery. Conclusion. Temporary fecal diversion can induce remission in otherwise refractory colorectal or perianal Crohn’s disease, but the chance of enduring remission after stoma reversal is low

Functional Segregation of Human Brain Networks Across the Lifespan: An Exploratory Analysis of Static and Dynamic Resting-State Functional Connectivity

Prior research has shown that during development, there is increased segregation between, and increased integration within, prototypical resting-state functional brain networks. Functional networks are typically defined by static functional connectivity over extended periods of rest. However, little is known about how time-varying properties of functional networks change with age. Likewise, a comparison of standard approaches to functional connectivity may provide a nuanced view of how network integration and segregation are reflected across the lifespan. Therefore, this exploratory study evaluated common approaches to static and dynamic functional network connectivity in a publicly available dataset of subjects ranging from 8 to 75 years of age. Analyses evaluated relationships between age and static resting-state functional connectivity, variability (standard deviation) of connectivity, and mean dwell time of functional network states defined by recurring patterns of whole-brain connectivity. Results showed that older age was associated with decreased static connectivity between nodes of different canonical networks, particularly between the visual system and nodes in other networks. Age was not significantly related to variability of connectivity. Mean dwell time of a network state reflecting high connectivity between visual regions decreased with age, but older age was also associated with increased mean dwell time of a network state reflecting high connectivity within and between canonical sensorimotor and visual networks. Results support a model of increased network segregation over the lifespan and also highlight potential pathways of top-down regulation among networks.</p

Defining Global Neuroendocrine Gene Expression Patterns Associated with Reproductive Seasonality in Fish

Many vertebrates, including the goldfish, exhibit seasonal reproductive rhythms, which are a result of interactions between external environmental stimuli and internal endocrine systems in the hypothalamo-pituitary-gonadal axis. While it is long believed that differential expression of neuroendocrine genes contributes to establishing seasonal reproductive rhythms, no systems-level investigation has yet been conducted. gamma2 receptor, calmodulin, and aromatase b by independent samplings of goldfish brains from six seasonal time points and real-time PCR assays.Using both theoretical and experimental strategies, we report for the first time global gene expression patterns throughout a breeding season which may account for dynamic neuroendocrine regulation of seasonal reproductive development

Knock-out of vasotocin reduces reproductive success in female zebrafish, Danio rerio

The vertebrate nonapeptide vasotocin/vasopressin is evolutionarily highly conserved and acts as neuromodulator and endocrine/paracrine signaling molecule. Circumstantial and mechanistic evidence from pharmacological manipulations of the vasotocin system in several teleost fishes suggest sex- and species-specific reproductive roles of vasotocin. While effects of vasotocin on teleost reproductive physiology involve both courtship behaviors and the regulation of the hypothalamic-pituitary-gonadal (HPG) axes, comprehensive studies investigating behavioral and physiological reproductive consequences of genetic ablation of vasotocin in a genetically tractable fish model, such as the zebrafish, are currently lacking. Here, we report the generation of homozygous CRISPR/Cas9-based vasotocin gene knock-out zebrafish. Breeding pairs of vasotocin knock-out fish produce significantly fewer fertilized eggs per clutch compared to wildtype fish, an effect coincident with reduced female quivering courtship behavior. Crossbreeding experiments reveal that this reproductive phenotype is entirely female-dependent, as vasotocin-deficient males reproduce normally when paired with female wild-type fish. Histological analyses of vasotocin knock-out ovaries revealed an overall reduction in oocytes and differential distribution of oocyte maturation stages, demonstrating that the reproductive phenotype is linked to oocyte maturation and release. Ovarian hormone quantification and gene expression analysis in mutant fish indicated reduced synthesis of Prostaglandin F2α, a hormone involved in ovarian maturation, egg release and regulation of female courtship behavior in some cyprinids. However, acute injection of vasotocin did not rescue the female mutant reproductive phenotype, suggesting a contribution of organizational effects of vasotocin. Together, this study provides further support for emerging roles of vasotocin in female teleost reproduction in an important teleost model species

Neuroendocrine Disruption: More than Hormones are Upset

Only a small proportion of the published research on endocrine-disrupting chemicals (EDC) directly examined effects on neuroendocrine processes. There is an expanding body of evidence that anthropogenic chemicals exert effects on neuroendocrine systems and that these changes might impact peripheral organ systems and physiological processes. Neuroendocrine disruption extends the concept of endocrine disruption to include the full breadth of integrative physiology (i.e., more than hormones are upset). Pollutants may also disrupt numerous other neurochemical pathways to affect an animal's capacity to reproduce, develop and grow, or deal with stress and other challenges. Several examples are presented in this review, from both vertebrates and invertebrates, illustrating that diverse environmental pollutants including pharmaceuticals, organochlorine pesticides, and industrial contaminants have the potential to disrupt neuroendocrine control mechanisms. While most investigations on EDC are carried out with vertebrate models, an attempt is also made to highlight the importance of research on invertebrate neuroendocrine disruption. The neurophysiology of many invertebrates is well described and many of their neurotransmitters are similar or identical to those in vertebrates; therefore, lessons learned from one group of organisms may help us understand potential adverse effects in others. This review argues for the adoption of systems biology and integrative physiology to address the effects of EDC. Effects of pulp and paper mill effluents on fish reproduction are a good example of where relatively narrow hypothesis testing strategies (e.g., whether or not pollutants are sex steroid mimics) have only partially solved a major problem in environmental biology. It is clear that a global, integrative physiological approach, including improved understanding of neuroendocrine control mechanisms, is warranted to fully understand the impacts of pulp and paper mill effluents. Neuroendocrine disruptors are defined as pollutants in the environment that are capable of acting as agonists/antagonists or modulators of the synthesis and/or metabolism of neuropeptides, neurotransmitters, or neurohormones, which subsequently alter diverse physiological, behavioral, or hormonal processes to affect an animal's capacity to reproduce, develop and grow, or deal with stress and other challenges. By adopting a definition of neuroendocrine disruption that encompasses both direct physiological targets and their indirect downstream effects, from the level of the individual to the ecosystem, a more comprehensive picture of the consequences of environmentally relevant EDC exposure may emerge

Epigenetics in teleost fish: from molecular mechanisms to physiological phenotypes

The final publication is available at Elsevier via https://doi.org/10.1016/j.cbpb.2018.01.006. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/While the field of epigenetics is increasingly recognized to contribute to the emergence of phenotypes in mammalian research models across different developmental and generational timescales, the comparative biology of epigenetics in the large and physiologically diverse vertebrate infraclass of teleost fish remains comparatively understudied. The cypriniform zebrafish and the salmoniform rainbow trout and Atlantic salmon represent two especially important teleost orders, because they offer the unique possibility to comparatively investigate the role of epigenetic regulation in 3R and 4R duplicated genomes. In addition to their sequenced genomes, these teleost species are well-characterized model species for development and physiology, and therefore allow for an investigation of the role of epigenetic modifications in the emergence of physiological phenotypes during an organism's lifespan and in subsequent generations. This review aims firstly to describe the evolution of the repertoire of genes involved in key molecular epigenetic pathways including histone modifications, DNA methylation and microRNAs in zebrafish, rainbow trout, and Atlantic salmon, and secondly, to discuss recent advances in research highlighting a role for molecular epigenetics in shaping physiological phenotypes in these and other teleost models. Finally, by discussing themes and current limitations of the emerging field of teleost epigenetics from both theoretical and technical points of view, we will highlight future research needs and discuss how epigenetics will not only help address basic research questions in comparative teleost physiology, but also inform translational research including aquaculture, aquatic toxicology, and human disease