Inflammatory bowel diseases (IBDs) are a group of disorders which include ulcerative colitis and Crohn’s disease. Obesity is becoming increasingly more common among patients with inflammatory bowel disease and plays a role in the development and course of the disease. This is especially true in the case of Crohn’s disease. The recent results indicate a special role of visceral adipose tissue and particularly mesenteric adipose tissue, also known as “creeping fat”, in pathomechanism, leading to intestinal inflammation. The involvement of altered adipocyte function and the deregulated production of adipokines, such as leptin and adiponectin, has been suggested in pathogenesis of IBD. In this review, we discuss the epidemiology and pathophysiology of obesity in IBD, the influence of a Western diet on the course of Crohn’s disease and colitis in IBD patients and animal’s models, and the potential role of adipokines in these disorders. Since altered body composition, decrease of skeletal muscle mass, and development of pathologically changed mesenteric white adipose tissue are well-known features of IBD and especially of Crohn’s disease, we discuss the possible crosstalk between adipokines and myokines released from skeletal muscle during exercise with moderate or forced intensity. The emerging role of microbiota and the antioxidative and anti-inflammatory enzymes such as intestinal alkaline phosphatase is also discussed, in order to open new avenues for the therapy against intestinal perturbations associated with IBD.
Although progress has been recently made in understanding of inflammatory bowel diseases (IBD), their etiology is unknown apart from several factors from adipose tissue and skeletal muscles such as cytokines, adipokines, and myokines were implicated in the pathogenesis of ulcerative colitis. We studied the effect high-fat diet (HFD; cholesterol up to 70%), low-fat diet (LFD; cholesterol up to 10%), and the normal diet (total fat up to 5%) in rats with TNBS colitis forced to treadmill running exercise (5 days/week) for 6 weeks. In nonexercising HFD rats, the area of colonic damage, colonic tissue weight, the plasma IL-1β, TNF-α, TWEAK, and leptin levels, and the expression of IL-1β-, TNF-α-, and Hif1α mRNAs were significantly increased and a significant fall in plasma adiponectin and irisin levels was observed as compared to LFD rats. In HFD animals, the exercise significantly accelerated the healing of colitis, raised the plasma levels of IL-6 and irisin, downregulated the expression of IL-1β, TNF-α, and Hif1α, and significantly decreased the plasma IL-1β, TNF α, TWEAK, and leptin levels. We conclude that HFD delays the healing of colitis in trained rats via decrease in CBF and plasma IL-1β, TNF-α, TWEAK, and leptin levels and the release of protective irisin.
BackgroundMajor human gastrointestinal pathogen Helicobacter pylori (H. pylori) colonizes the gastric mucosa causing inflammation and severe complications including cancer, but the involvement of fibroblasts in the pathogenesis of these disorders in H. pylori‐infected stomach has been little studied. Normal stroma contains few fibroblasts, especially myofibroblasts. Their number rapidly increases in the reactive stroma surrounding inflammatory region and neoplastic tissue; however, the interaction between H. pylori and fibroblasts remains unknown. We determined the effect of coincubation of normal rat gastric fibroblasts with alive H. pylori (cagA+vacA+) and H. pylori (cagA−vacA−) strains on the differentiation of these fibroblasts into cells possessing characteristics of cancer‐associated fibroblasts (CAFs) able to induce epithelial‐mesenchymal transition (EMT) of normal rat gastric epithelial cells (RGM‐1).Materials and MethodsThe panel of CAFs markers mRNA was analyzed in H. pylori (cagA+vacA+)‐infected fibroblasts by RT‐PCR. After insert coculture of differentiated fibroblasts with RGM‐1 cells from 24 up to 48, 72, and 96 hours, the mRNA expression for EMT‐associated genes was analyzed by RT‐PCR.ResultsThe mRNA expression for CAFs markers was significantly increased after 72 hours of infection with H. pylori (cagA+vacA+) but not H. pylori (cagA−vacA−) strain. Following coculture with CAFs, RGM‐1 cells showed significant decrease in E‐cadherin mRNA, and the parallel increase in the expression of Twist and Snail transcription factors mRNA was observed along with the overexpression of mRNAs for TGFβR, HGFR, FGFR, N‐cadherin, vimentin, α‐SMA, VEGF, and integrin‐β1.Conclusion Helicobacter pylori (cagA+vacA+) strain induces differentiation of normal fibroblasts into CAFs, likely to initiate the EMT process in RGM‐1 epithelial cell line.
1-Methylnicotinamide (MNA) is one of the major derivatives of nicotinamide, which was recently shown to exhibit antithrombotic and antiinflammatory actions. However, it is not yet known whether MNA affects gastric mucosal defense. The effects of exogenous MNA were studied on gastric secretion and gastric lesions induced in rats by 3.5 h of water immersion and water restraint stress (WRS) or in rats administered 75% ethanol. MNA [6.25-100 mg/kg intragastrically (i.g.)] led to a dose-dependent rise in the plasma MNA level, inhibited gastric acid secretion, and attenuated these gastric lesions induced by WRS or ethanol. The gastroprotective effect of MNA was accompanied by an increase in the gastric mucosal blood flow and plasma calcitonin gene-related peptide (CGRP) levels, the preservation of prostacyclin (PGI 2 ) generation (measured as 6-keto-PGF1␣), and an overexpression of mRNAs for cyclooxygenase (COX)-2 and CGRP in the gastric mucosa. R-3-(4-Fluoro-phenyl)-2-[5-(4-fluoro-phenyl)-benzofuran-2-ylmethoxycarbonylamino]-propionic acid (RO 324479), which is the selective antagonist of IP/PGI 2 receptors, reversed the effects of MNA on gastric lesions and GBF. MNA-induced gastroprotection was attenuated by suppression of COX-1 [5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole; SC-560] and COX-2 [4-(4-methylsulfonylphenyl)-3-phenyl-5H-furan-2-one; rofecoxib] activity, capsaicin denervation, and by the pretreatment with CGRP 8-37 or capsazepine. Addition of exogenous PGI 2 or CGRP restored the MNA-induced gastroprotection in rats treated with COX-1 and COX-2 inhibitors or in those with capsaicin denervation. WRS enhanced MDA content while decreasing superoxide dismutase (SOD) activity in the gastric mucosa, but pretreatment with MNA reversed these changes. MNA exerts potent gastroprotection against WRS damage via mechanisms involving cooperative action of PGI 2 and CGRP in preservation of microvascular flow, antioxidizing enzyme SOD activity, and reduction in lipid peroxidation.Nicotinamide (NA) is a precursor for the coenzyme -nicotinamide adenine dinucleotide (NAD ϩ ), which serves as an essential nutrient for cellular growth, and it participates in the regulation of multiple cellular functions, including apoptosis and response to injury (Mukherjee et al., 1997;Maiese and Chong, 2003). Indeed, NA has been reported to exert several physiological and pharmacological effects, including the prevention of ATP depletion, inhibition of poly(ADPribose) polymerase, prevention of apoptosis, and suppression of lipid peroxidation (Klaidman et al., 1996(Klaidman et al., , 2003. NA also possesses anti-inflammatory properties (Ogata et al., 2002;Ungerstedt et al., 2003) and exhibits angiogenic activity by promoting the growth of capillaries (Morris et al., 1989). Article, publication date, and citation information can be found at
Hydrogen sulfide (H2S) plays an important role in human physiology, exerting vasodilatory, neuromodulatory and anti-inflammatory effects. H2S has been implicated in the mechanism of gastrointestinal integrity but whether this gaseous mediator can affect hemorrhagic lesions induced by stress has been little elucidated. We studied the effect of the H2S precursor L-cysteine, H2S-donor NaHS, the H2S synthesizing enzyme (CSE) activity inhibitor- D,L-propargylglycine (PAG) and the gastric H2S production by CSE/CBS/3-MST activity in water immersion and restraint stress (WRS) ulcerogenesis and the accompanying changes in gastric blood flow (GBF). The role of endogenous prostaglandins (PGs) and sensory afferent nerves releasing calcitonin gene-related peptide (CGRP) in the mechanism of gastroprotection induced by H2S was examined in capsaicin-denervated rats and those pretreated with capsazepine to inhibit activity of vanilloid receptors (VR-1). Rats were pretreated with vehicle, NaHS, the donor of H2S and or L-cysteine, the H2S precursor, with or without the concurrent treatment with 1) nonselective (indomethacin) and selective cyclooxygenase (COX)-1 (SC-560) or COX-2 (rofecoxib) inhibitors. The expression of mRNA and protein for COX-1 and COX-2 were analyzed in gastric mucosa pretreated with NaHS with or without PAG. Both NaHS and L-cysteine dose-dependently attenuated severity of WRS-induced gastric lesions and significantly increased GBF. These effects were significantly reduced by pretreatment with PAG and capsaicin denervation. NaHS increased gastric H2S production via CSE/CBS but not 3-MST activity. Inhibition of COX-1 and COX-2 activity significantly diminished NaHS- and L-cysteine-induced protection and hyperemia. NaHS increased expression of COX-1, COX-2 mRNAs and proteins and raised CGRP mRNA expression. These effects of NaHS on COX-1 and COX-2 protein contents were reversed by PAG and capsaicin denervation. We conclude that H2S exerts gastroprotection against WRS-induced gastric lesions by the mechanism involving enhancement in gastric microcirculation mediated by endogenous PGs, sensory afferent nerves releasing CGRP and the activation of VR-1 receptors.
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