Non-alcoholic fatty liver disease (NAFLD) constitutes a spectrum of disease states characterized by hepatic steatosis and is closely associated to obesity and the metabolic syndrome. In non-alcoholic steatohepatitis (NASH), additionally, inflammatory changes and hepatocellular damage are present, representing a more severe condition, for which the treatment is an unmet medical need. Pathophysiologically, the immune system is one of the main drivers of NAFLD progression and other obesity-related comorbidities, and both the innate and adaptive immune system are involved. T cells form the cellular component of the adaptive immune system and consist of multiple differentially active subsets, i.e., T helper (Th) cells, regulatory T (Treg) cells, and cytotoxic T (Tc) cells, as well as several innate T-cell subsets. This review focuses on the role of these T-cell subsets in the pathogenesis of NAFLD, as well as the association with obesity and type 2 diabetes mellitus, reviewing the available evidence from both animal and human studies. Briefly, Th1, Th2, Th17, and Th22 cells seem to have an attenuating effect on adiposity. Th2, Th22, and Treg cells seem to decrease insulin resistance, whereas Th1, Th17, and Tc cells have an aggravating effect. Concerning NAFLD, both Th22 and Treg cells appear to have an overall tempering effect, whereas Th17 and Tc cells seem to induce more liver damage and fibrosis progression. The evidence regarding the role of the innate T-cell subsets is more controversial and warrants further exploration.
Both dyspeptic and gastro-oesophageal reflux-like symptoms are frequent in the general population, but their degree of overlap is unknown. In severe functional dyspepsia (FD), symptoms are organized in factors associated with pathophysiological mechanisms. The aims of this study were: (i) to assess the prevalence of dyspeptic symptoms with and without overlapping reflux symptoms in the general population and their impact on daily life and on healthcare utilization; and (ii) to compare symptom groupings in the general population to FD patients. A total of 2025 subjects, representative of the Belgian general population, were used in this study. The subjects were submitted to a questionnaire with validated questions on their dyspeptic and reflux symptoms and with evaluators of impact on daily life and use of healthcare resources. Significant dyspeptic symptoms were found in 417 (20.6%). Overlapping reflux symptoms were present in 141 (33.8%). In this group, symptoms were more frequent and more severe. Dyspeptic symptoms induced weight loss (12.7%) and absenteeism (12.4%), affected daily life (61.2%) and generated use of healthcare resources, such as medical consultations (61.4%) and medication (70.9%). Factor analysis revealed a three-component structure with factor 1 including fullness, bloating and early satiety, factor 2 including nausea and vomiting and factor 3 including discomfort, pain, belching and reflux. If forced in a four-factor model, the analysis separates belching as independent factor. Dyspeptic symptoms are frequent in the general population, with overlapping reflux symptoms and increased symptom burden in about a third.
Treatment with proteins of S. mansoni and A. caninum ameliorated TNBS-induced colitis in mice. S. mansoni proteins increased mRNA expression of regulatory cytokines while suppressing expression of proinflammatory cytokines. Therefore, we suggest a therapeutic potential for helminth proteins in the treatment of IBD.
Non-alcoholic fatty liver disease can progress to steatohepatitis and fibrosis, and is also associated with impaired liver regeneration. The pathophysiology remains elusive. We recently showed that severe steatosis is associated with an increase in portal pressure, suggesting liver flow impairment. The objective of this study is to directly assess total intrahepatic resistance and its potential functional and structural determinants in an in situ perfusion model. Male Wistar rats fed a control (n ¼ 30) or a methionine-choline-deficient (MCD) diet (n ¼ 30) for 4 weeks were compared. Liver tissue and serum analysis, in vivo haemodynamic measurements, in situ perfusion experiments and vascular corrosion casts were performed. The MCD group showed severe steatosis without inflammation or fibrosis on histology. Serum levels and liver tissue gene expression of interleukin (IL)-6, tumour necrosis factor-a, IL-1b and interferon-g, liver tissue myeloperoxidase activity and liver immunohistochemistry with anti-CD68 and anti-a smooth muscle actin were comparable between groups, excluding significant inflammation. Flow-pressure curves were significantly different between groups for all flows (slope values: 0.1636±0.0605 mm Hg/ml/min in controls vs 0.7270±0.0408 mm Hg/ml/min in MCD-fed rats, Po0.001), indicating an increased intrahepatic resistance, which was haemodynamically significant (portocaval pressure gradient 2.2 ± 1.1 vs 8.2 ± 1.3 mm Hg in controls vs MCD, Po0.001). Dose-response curves to acetylcholine were significantly reduced in MCD-fed rats (Po0.001) as was the responsiveness to methoxamine (Po0.001). Vascular corrosion casts showed a replacement of the regular sinusoidal anatomy by a disorganized pattern with multiple interconnections and vascular extensions. Liver phosphorylated endothelial NO synthase (eNOS)/eNOS and serum nitrite/nitrate were not increased in severe steatosis, whereas liver thromboxane synthase expression, liver endothelin-1 (ET-1) expression and serum andothelin-1 concentration were significantly increased. Severe steatosis induces a haemodynamically significant increase in intrahepatic resistance, which precedes inflammation and fibrogenesis. Both functional (endothelial dysfunction and increased thromboxane and ET-1 synthesis) and structural factors are involved. This phenomenon might significantly contribute to steatosis-related disease.
1 In a rat model of experimental ileus, the e ect of blockade of adrenergic and nitrergic neurotransmission was studied on the intestinal transit of Evans blue. 2 Ether anaesthesia and skin incision had no in¯uence on the transit. Laparotomy signi®cantly inhibited the transit of Evans blue. This inhibition was even more pronounced when the small intestine was manipulated. 3 Reserpine (5 mg kg 71 ), a drug that blocks adrenergic neurotransmission, completely reversed the inhibition of the transit induced by laparotomy but only partially reversed that induced by laparotomy with manipulation of the small intestine., a nitric oxide synthase inhibitor, completely reversed the reserpine-resistant inhibition induced by laparotomy with manipulation of the small intestine. The e ect of L-NOARG was prevented by concomitant administration of L-arginine. L-Arginine itself slightly, but signi®cantly enhanced the inhibition. S-methylisothiourea and aminoguanidine, selective inhibitors of the inducible NO synthase, had no e ect on the transit after the three operations. 5 Treatment of the rats with reserpine plus L-NOARG had no additional e ect on the transit after laparotomy as compared to reserpine alone. However, reserpine plus L-NNA completely reversed the inhibition of the transit induced by laparotomy with manipulation of the small intestine. 6 These ®ndings support the involvement of adrenergic pathways in the pathogenesis of ileus and suggest that the additional inhibitory e ect of mechanical stimulation results from an enhanced release of NO by the constitutive NO synthase.
Supportive student-doctor relationships, student-centred education and guidance that addresses the needs of the doctor-as-person are central to the development of patient-centredness. Medical education requires patient-centred, self-caring and self-aware role models.
Enteric glial cells (EGC) actively mediate acute and chronic inflammation in the gut; EGC proliferate and release neurotrophins, growth factors, and pro-inflammatory cytokines which, in turn, may amplify the immune response, representing a very important link between the nervous and immune systems in the intestine. Cannabidiol (CBD) is an interesting compound because of its ability to control reactive gliosis in the CNS, without any unwanted psychotropic effects. Therefore the rationale of our study was to investigate the effect of CBD on intestinal biopsies from patients with ulcerative colitis (UC) and from intestinal segments of mice with LPS-induced intestinal inflammation. CBD markedly counteracted reactive enteric gliosis in LPS-mice trough the massive reduction of astroglial signalling neurotrophin S100B. Histological, biochemical and immunohistochemical data demonstrated that S100B decrease was associated with a considerable decrease in mast cell and macrophages in the intestine of LPS-treated mice after CBD treatment. Moreover the treatment of LPS-mice with CBD reduced TNF-α expression and the presence of cleaved caspase-3. Similar results were obtained in ex vivo cultured human derived colonic biopsies. In biopsies of UC patients, both during active inflammation and in remission stimulated with LPS+INF-γ, an increased glial cell activation and intestinal damage were evidenced. CBD reduced the expression of S100B and iNOS proteins in the human biopsies confirming its well documented effect in septic mice. The activity of CBD is, at least partly, mediated via the selective PPAR-gamma receptor pathway. CBD targets enteric reactive gliosis, counteracts the inflammatory environment induced by LPS in mice and in human colonic cultures derived from UC patients. These actions lead to a reduction of intestinal damage mediated by PPARgamma receptor pathway. Our results therefore indicate that CBD indeed unravels a new therapeutic strategy to treat inflammatory bowel diseases.
Background and aims: Crohn's disease, characterised by chronic T helper 1 (Th1) inflammation and dysmotility of the gut, is most prevalent in developed countries. Parasitic infections are most prevalent in developing countries and induce a T helper 2 (Th2) immune response. We hypothesised that this Th2 immune response protects against Th1 gut inflammation. Methods: The parasite Schistosoma mansoni induces a transient Th2 immune response in the semipermissive rat host. 2,4,6-Trinitrobenzene sulphonic acid (TNBS) induced colitis is an experimental model of Th1-like gut inflammation. The effect of concurrent infection with S mansoni on the course of TNBS induced colitis was assessed using macroscopic and microscopic damage scores, histology, myeloperoxidase (MPO) activity assay, cytokine production assay, and by studying in vitro contractility of longitudinal and circular colonic muscle strips. Results: TNBS induced colitis that spontaneously healed after four weeks. Concurrent infection with S mansoni significantly reduced the duration of TNBS induced colitis to two weeks, as shown by macroscopic and microscopic damage scores and by a faster decrease in colonic MPO activity. TNBS increased colonic interleukin 2 (IL-2) production whereas S mansoni increased splenic IL-4 and IL-2 levels. Contractility of longitudinal and circular muscle strips was maximally inhibited one week after TNBS and normalised after three weeks. After four weeks, longitudinal muscle strip contractility was significantly increased. Concurrent infection with S mansoni normalised longitudinal muscle contractility after one week whereas circular muscle contractility remained inhibited. Conclusions: Concurrent infection with S mansoni significantly attenuates TNBS induced colitis in the rat. Inflammation induced disturbances in contractility of longitudinal and circular colonic muscle strips may outlast the inflammatory reaction.
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