Intestinal barrier function Research Papers (original) (raw)

A new strategy for the skin delivery of bioactive compounds has been developed, using enzymes involved in the maintenance of the epidermal barrier function and the enzymatic transformation of corresponding precursors. This new strategy... more

A new strategy for the skin delivery of bioactive compounds has been developed, using enzymes involved in the maintenance of the epidermal barrier function and the enzymatic transformation of corresponding precursors. This new strategy has been tested with regard to two enzymatic activities of the skin barrier: extracellular glucosidase and esterase/lipase. An analysis of the requirements for the glycosidic bond hydrolysis of any glycoconjugate by beta-glucocerebrosidase indicates that the release of the moiety linked to the glucose unit is obtained as long as the glycosidic bond being broken is not hindered, and as long as the leaving group property of the released moiety is good enough. This strategy was first applied to the release of the antioxidant delta-tocopherol. It was then extended to retinoic acid by introducing a spacer between the glucose unit and the bioactive moiety. This spacer was either a good leaving group such as hydroquinone, or a structure akin to a ceramide, n...

Al though the aetiology of inflammatory bowel disease (IBD) remains unknown, the pathogenesis is gradually being unravelled, seeming to be the result of a combination of environmental, genetic, and immunological factors in which an... more

Al though the aetiology of inflammatory bowel disease (IBD) remains unknown, the pathogenesis is gradually being unravelled, seeming to be the result of a combination of environmental, genetic, and immunological factors in which an uncontrolled immune response within the intestinal lumen leads to inflammation in genetically predisposed individuals. Multifactorial evidence suggests that a defect of innate immune response to microbial agents is involved in IBD. This editorial outlines the immunopathogenesis of IBD and their current and future therapy. We present IBD as a result of dysregulated mucosal response in the intestinal wall facilitated by defects in epithelial barrier function and the mucosal immune system with excessive production of cytokines growth factors, adhesion molecules, and reactive oxygen metabolites, resulting in tissue injury. Established and evolving therapies are discussed in the second part of this editorial and at the end of this section we review new therapi...

Recognition of bacterial products by the innate immune system is dependent on pattern-recognition receptors: toll-like receptor 9 (TLR-9) in the case of bacterial DNA. We hypothesized that bacterial DNA can directly affect enteric... more

Recognition of bacterial products by the innate immune system is dependent on pattern-recognition receptors: toll-like receptor 9 (TLR-9) in the case of bacterial DNA. We hypothesized that bacterial DNA can directly affect enteric epithelial cells. RT-PCR revealed constitutive TLR-9 mRNA expression in three human colonic epithelial cell lines (T84, HT-29, Caco-2) and THP-1 monocytes. Epithelial cells, in six-well culture plates or on filter supports, were exposed to E. coli DNA (1-50 microg/ml), synthetic CpG-rich oligonucleotides, or calf thymus DNA for 6-48 h. Exposure to E. coli DNA resulted in an increase in IL-8 mRNA, and a time- and dose-dependent increase in IL-8 secretion. Also, CpG oligonucleotides induced epithelial IL-8 production, whereas calf thymus DNA did not. Exposure to E. coli DNA resulted in phosphorylation of ERK 1/2 MAPK and inhibitors of ERK activity (PD98059, UO126) significantly reduced the evoked IL-8 production. In contrast, inhibitors of NFkappaB activity ...

Worldwide, up to 20% of children and adolescents experience mental disorders, which are the leading cause of disability in young people. Research shows that serum zonulin levels are associated with increased intestinal permeability (IP),... more

Worldwide, up to 20% of children and adolescents experience mental disorders, which are the leading cause of disability in young people. Research shows that serum zonulin levels are associated with increased intestinal permeability (IP), affecting neural, hormonal, and immunological pathways. This systematic review and meta-analysis aimed to summarize evidence from observational studies on IP in children diagnosed with mental disorders. The review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search of the Cochrane Library, PsycINFO, PubMed, and the Web of Science identified 833 records. Only non-intervention (i.e., observational) studies in children (<18 years) diagnosed with mental disorders, including a relevant marker of intestinal permeability, were included. Five studies were selected, with the risk of bias assessed according to the Newcastle–Ottawa scale (NOS). Four articles were identified as strong and on...

Within mucosal tissues, regulation of nucleotide metabolism may be directed at various physiological/pathophysiological levels by myriad cell types. Adenosine (Ado) can regulate a number of processes at the mucosa, e.g. dampening of the... more

Within mucosal tissues, regulation of nucleotide metabolism may be directed at various physiological/pathophysiological levels by myriad cell types. Adenosine (Ado) can regulate a number of processes at the mucosa, e.g. dampening of the inflammatory response and resultant tissue protection. Ado receptors are widely expressed on a variety of organs and cell types and have been demonstrated to be central to the modulation of inflammation. In many instances, local Ado levels are dictated by extracellular sources of adenine nucleotides. Activated neutrophils and platelet degranulation are two such important sources of ATP and ADP. Sequential phosphohydrolysis of adenine nucleotides by CD39 and CD73 results in the conversion of ATP and ADP to AMP, and the subsequent conversion of AMP to Ado, whereby signaling through Ado receptors can elicit effects such as increase in endothelial barrier function, increase in epithelial electrogenic Cl- secretion and water transport. Further regulation of Ado signaling has been observed under hypoxic conditions, due to hypoxia-inducible factor-1 (HIF-1)-regulated expression of A2BR and CD73, whereby additional SP-1 transcription factor activity has been identified as being required for hypoxic induction of CD39 expression in endothelial cells. Here we describe the different levels of regulation of adenine nucleotide metabolism and the resultant functional cell-cell signaling at the mucosa.

In this paper we present a new class of kernel functions for primal-dual interior point methods (IPMs) in linear optimization. The proposed functions have a finite value at the boundary of the feasible region. They are not exponentially... more

In this paper we present a new class of kernel functions for primal-dual interior point methods (IPMs) in linear optimization. The proposed functions have a finite value at the boundary of the feasible region. They are not exponentially convex and also not strongly convex like the usual barrier functions. In spite of this, the iteration bound of large-update interior-point methods based on these functions and analyzed in this paper, are shown to be O ‡ n 1 1+p lognlog n † · ; where p is a parameter, p 2 (0;1). For small-update interior point methods the iteration bound is O ¡p nlog n† ¢ ; which is currently the best-known bound for primal-dual IPMs.

Stratifi ed epithelia line all external and internal body surfaces of mammals and function to protect us from water loss, environmental insults, chemical damage, and infection. This protec-tive barrier is composed of a complex mixture of... more

Stratifi ed epithelia line all external and internal body surfaces of mammals and function to protect us from water loss, environmental insults, chemical damage, and infection. This protec-tive barrier is composed of a complex mixture of structural proteins and specialized lipids that together form the anuclear squames of the stratum corneum. Filaggrin and caspase-14 are two genes expressed in the granular layer of epidermis and other stratified keratinizing epithelia. Filaggrin is a keratin-binding protein present in the lower layers of the stratum corneum which plays a key role in barrier function. Filaggrin is synthesized as a large precursor, profi laggrin, that undergoes specific processing during keratinocyte differentiation to produce filaggrin. In the middle and upper layers of the stratum corneum, fi laggrin is degraded to free amino acids which have several functions including water adsorption. Recent work has shown that loss-of-function mutations in the fi laggrin (FLG) g...

This is an extract about URIC ACID, ARGININE, CITRULLINE POSSIBLE RELATION WITH SOME DISEASES like arthritis reumathoid, irritable bowel syndrome etc. created by JoanCarles Testagorda Garcia of the work Anatomia Magna vol.I created by... more

This is an extract about URIC ACID, ARGININE, CITRULLINE POSSIBLE RELATION WITH SOME DISEASES like arthritis reumathoid, irritable bowel syndrome etc.
created by JoanCarles Testagorda Garcia of the work Anatomia Magna vol.I created by JoanCarles Testagorda Garcia. The total content of this extract (9pages) and the total content, the total original ideas, equations, reasonings of the work Anatomia Magna vol.I more than 150pages are created by JoanCarles Testagorda Garcia.