Changes of the peptide YY levels in the intestinal tissue of rats with experimental colitis following oral administration of mesalazine and prednisolone

Protective potential of Bacillus subtilis (NMCC-path-14) against extraarticular manifestations during acute and sub-acute phase of arthritis using mice model

Extra-articular manifestations (EAM), which are associated with rheumatoid arthritis (RA), affect the quality of life of patients and are one of the critical causes of early mortality. This study was aimed at investigating whether Bacillus subtilis NMCC-path-14 (1 × 108 CFU/animal/day) could serve as a valuable therapeutic agent in managing EAM using complete Freund's adjuvant (CFA) induced arthritis during acute and sub-acute phases. Arthritis was induced using intra-dermal administration of CFA in the right hind paw of mice on day 1. Dexamethasone (Dexa) (5 mg/kg/day/animal) was used as a standard treatment. Animals in Dexa and Bacillus subtilis concurrent treatment (BS-CT) received treatments on day 1. The Bacillus subtilis pre-treatment (BS-PT) group received a probiotic dose 7 days before arthritis induction. Parameters like body weight, relative organ weight, colon length, hematology, serum biochemistry, antioxidant capacity, and histopathology of liver, kidney, spleen, colon, stress-related behavioral changes, and cortisol levels were evaluated on days 7 (acute) and 14 (sub-acute). Dexa failed to manage the EAM in arthritic mice and instead exacerbated them. On the other hand, B. subtilis NMCC-path-14 significantly declined EAM with no notable side effects, highlighting its safety and effectiveness. The current data show that B. subtilis NMCC-path-14 may be an alternative option for arthritis treatment that can reduce systemic symptoms associated with arthritis. More studies are required to comprehend the underlying mechanisms of mitigating the EAM by B. subtilis NMCC-path-14.

Immunostimulant, hepatoprotective, and nephroprotective potential of Bacillus subtilis (NMCC-path-14) in comparison to dexamethasone in alleviating CFA-induced arthritis

To investigate and compare efficacy as well as safety of Bacillus subtilis and dexamethasone (Dexa) in complete Freund's adjuvant (CFA)-induced arthritis, we used glucocorticoid monotherapy (Dexa 5 mg/kg/day) and B. subtilis (1 × 108 CFU/animal/day p.o) as pre-treatment and concurrent treatment for a duration of 35 days. Specific emphasis was on chronic aspect of this study since long-term use of Dexa is known to produce undesirable side effects. Treatment with Dexa significantly attenuated the arthritic symptoms but produced severe side effects like weight loss, increased mortality, immunosuppression, and altered histology of liver, kidney, and spleen. Oxidative stress was also elevated by Dexa in these organs which contributed to the damage. Treatment with B. subtilis improved symptoms of arthritis without producing any deleterious side effects as seen with Dexa therapy. Immunohistochemistry (IHC) profile revealed decreased expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α), and increased nuclear factor erythroid 2-related factor 2 (Nrf-2) expression by B. subtilis and Dexa treatment in ankle joint of arthritic mice. Radiological scores were also improved by both treatments. This study concludes that B. subtilis could be an effective alternative for treating arthritis than Dexa since it does not produce life-threatening side effects on prolong treatment.

Potential Effects of Boldine on Oxidative Stress, Apoptosis, and Inflammatory Changes Induced by the Methylprednisolone Hepatotoxicity in Male Wistar Rats

Background

Synthetic glucocorticoid therapeutic agent methylprednisolone (MPL), when used for an extended period of time at high dose, promotes the development of reactive oxygen species (ROS)-induced liver toxicity. This study investigated the role of boldine, a natural antioxidant with anti-apoptotic and anti-inflammatory properties, against MPL-induced hepatoxicity in male Wistar rats.

Methods

120 rats were divided into eight equal groups: G1 (control), G2, 3, and 4 (rats orally administered 5, 10, and 50 mg boldine/kg b.w./day; respectively, for 28 days), G5 (rats intramuscularly injected with 100 mg MPL/kg b.w. only on the last three days), G6, 7, and 8 (rats administered boldine + MPL). After the last MPL injection, rats were sacrificed at intervals of 1, 24, and 48 h.

Results

There was a significant decrease in WBCs, RBCs count, and HGB levels, as well as an increase in PLT count, ALT, AST, TG, and LDL levels, and a decrease in HDL level in serum. Oxidative stress markers levels increased at all times, and gene expression of antioxidant enzymes increased at 24h. Immunohistochemical analysis revealed that cytochrome c levels significantly increased after MPL treatment. The COMET assay revealed detectable DNA lesions. There was no immune reactivity of IL-6 expressions as an inflammatory response marker.

Conclusions

Oral administration of boldine has a modulatory protective, antioxidant, and anti-apoptotic effect against free radicals.

Antioxidant effect of mesalazine in the experimental colitis model induced by acetic acid

Introduction Inflammatory bowel disease (IBD) is characterized by a chronic inflammation of the gastrointestinal tract, without specific cause or pathogen.

Objective The effect of mesalazine in a colitis model induced by acetic acid (AA) was evaluated.

Methods We used 40 Wistar rats, ±350 g, divided into 4 groups: control (CO); control + mesalazine (CO + M); colitis (CL) and colitis + M (CL + M) at 24 and 48 h of treatment. The animals received the substances by an intracolonic enema of AA 4% and treatment with mesalazine PO 20 mg/kg after colitis induction.

Results Mesalazine reduced tissue damage in the gut, normalized sphincter anal pressure levels and decreased lipid peroxidation, metabolites of nitric oxide and iNOS and NF-kB expression in the treated groups in both treatment time points (24 and 48 h), as well as the activity of antioxidant enzymes.

Conclusion Mesalazine was effective in reducing tissue damage and oxidative and inflammatory damage, restored antioxidant capacity and increased anal sphincter pressure levels, possibly due to its antioxidant effect.

Enteroendocrine cells-sensory sentinels of the intestinal environment and orchestrators of mucosal immunity

The intestinal epithelium must balance efficient absorption of nutrients with partitioning commensals and pathogens from the bodies' largest immune system. If this crucial barrier fails, inappropriate immune responses can result in inflammatory bowel disease or chronic infection. Enteroendocrine cells represent 1% of this epithelium and have classically been studied for their detection of nutrients and release of peptide hormones to mediate digestion. Intriguingly, enteroendocrine cells are the key sensors of microbial metabolites, can release cytokines in response to pathogen associated molecules and peptide hormone receptors are expressed on numerous intestinal immune cells; thus enteroendocrine cells are uniquely equipped to be crucial and novel orchestrators of intestinal inflammation. In this review, we introduce enteroendocrine chemosensory roles, summarize studies correlating enteroendocrine perturbations with intestinal inflammation and describe the mechanistic interactions by which enteroendocrine and mucosal immune cells interact during disease; highlighting this immunoendocrine axis as a key aspect of innate immunity.

Gastrointestinal Motility, Mucosal Mast Cell, and Intestinal Histology in Rats: Effect of Prednisone

Our aim was to verify the effects of prednisone related to gastrointestinal motility, intestinal histology, and mucosal mast cells in rats. Two-month-old male Wistar rats were randomly assigned to control group (vehicle) animals receiving saline 0.9% (n = 7) or treated orally with 0.625 mg/kg/day of prednisone (n = 7) or 2.5 mg/kg/day of prednisone (n = 7) during 15 days. Mast cells and other histologic analyses were performed in order to correlate to gastric emptying, cecum arrival, and small intestine transit evaluated by Alternating Current Biosusceptometry. Results showed that prednisone in adult rats increased the frequency of gastric contractions, hastened gastric emptying, slowed small intestinal transit, and reduced mucosal mast cells. Histologically, the treatment with both doses of prednisone decreased villus height, whereas longitudinal and circular muscles and crypt depth were not affected. These findings indicate an impairment of intestinal absorption which may be linked to several GI dysfunctions and symptoms. The relationship between gastrointestinal motor disorders and cellular immunity needs to be clarified in experimental studies since prednisone is one of the most prescribed glucocorticoids worldwide.

Abnormalities in endocrine and immune cells are correlated in dextran‑sulfate‑sodium‑induced colitis in rats

The interaction between the gut hormones and the immune system has been suggested to serve an important role in the pathophysiology of inflammatory bowel disease. The aims of the present study were to elucidate the possible abnormalities in the colonic endocrine cells in rats with dextran sodium sulfate (DSS)-induced colitis, and to determine whether they are correlated with alterations in the immune cells. A total of 24 male Wistar rats were divided into two groups: Control and DSS-induced colitis. Colonic tissues were harvested via postmortem laparotomy from all of the animals at the end of the experimental period, and fixed and sectioned for histology. The colonic endocrine and immune cells in those tissue samples were immunostained and their densities quantified by computerized image analysis. The densities of chromogranin A, serotonin, peptide YY and oxyntomodulin cells were significantly higher, and those of pancreatic peptide and somatostatin cells were lower in rats with DSS-induced colitis than in the controls. The densities of mucosal leukocytes, T and B lymphocytes, macrophages/monocytes, and mast cells were significantly higher than in the controls, and these changes were closely associated with the aforementioned changes in all endocrine cell types. These observations indicate an interaction between intestinal hormones and the immune system as represented by immune cells.

Changes in enteroendocrine and immune cells following colitis induction by TNBS in rats

Approximately 3.6 million individuals suffer from inflammatory bowel disease (IBD) in the western world, with an annual global incidence rate of 3–20 cases/100,000 individuals. The etiology of IBD is unknown, and the currently available treatment options are not satifactory for long-term treatment. Patients with inflammatory bowel disease present with abnormalities in multiple intestinal endocrine cell types, and a number of studies have suggested that interactions between gut hormones and immune cells may serve a pivotal role in the pathophysiology of IBD. The aim of the present study was to investigate alterations in colonic endocrine cells in a rat model of IBD. A total of 30 male Wistar rats were divided into control and trinitrobenzene sulfonic acid (TNBS)-induced colitis groups. Colonoscopies were performed in the control and TNBS groups at day 3 following the induction of colitis, and colonic tissues were collected from all animals. Colonic endocrine and immune cells in the obtained tissue samples were immunostained and their densities were quantified. The densities of chromogranin A, peptide YY, and pancreatic polypeptide-producing cells were significantly lower in the TNBS group compared with the control group, whereas the densities of serotonin, oxyntomodulin, and somatostatin-producing cells were significantly higher in the TNBS group. The densities of mucosal leukocytes, B/T-lymphocytes, T-lymphocytes, B-lymphocytes, macrophages/monocytes and mast cells were significantly higher in the TNBS group compared with the controls, and these differences were strongly correlated with alterations in all endocrine cell types. In conclusion, the results suggest the presence of interactions between intestinal hormones and immune cells.

Enteroendocrine cells, stem cells and differentiation progenitors in rats with TNBS-induced colitis

Patients with inflammatory bowel disease (IBD), as well as animal models of human IBD have abnormal enteroendocrine cells. The present study aimed to identify the possible mechanisms underlying these abnormalities. For this purpose, 40 male Wistar rats were divided into 4 groups as follows: the control group, the group with trinitrobenzene sulfonic acid (TNBS)-induced colitis with no treatment (TNBS group), the group with TNBS-induced colitis treated with 3-[(dodecylthiocarbonyl)-methyl]-glutarimide (DTCM-G; an activator protein-1 inhibitor) (DTCM-G group), and the group with TNBS-induced colitis treated with dehydroxymethylepoxyquinomicin (DHMEQ; a nuclear factor-κB inhibitor) treatment (DHMEQ group). Three days following the administration of TNBS, the rats were treated as follows: those in the control and TNBS groups received 0.5 ml of the vehicle [0.5% carboxymethyl cellulose (CMC)], those in the DTCM-G group received DTCM-G at 20 mg/kg body weight in 0.5% CMC, and those in the DHMEQ group received DHMEQ at 15 mg/kg body weight in 0.5% CMC. All injections were administered intraperitoneally twice daily for 5 days. The rats were then sacrificed, and tissue samples were taken from the colon. The tissue sections were stained with hemotoxylin-eosin and immunostained for chromogranin A (CgA), serotonin, peptide YY (PYY), oxyntomodulin, pancreatic polypeptide (PP), somatostatin, Musashi1 (Msi1), Math1, Neurogenin3 (Neurog3) and NeuroD1. The staining was quantified using image analysis software. The densities of CgA-, PYY-, PP-, Msi1-, Neurog3- and NeuroD1-positive cells were significantly lower in the TNBS group than those in the control group, while those of serotonin-, oxyntomodulin- and somatostatin-positive cells were significantly higher in the TNBS group than those in the control group. Treatment with either DTCM-G or DHMEQ restored the densities of enteroendocrine cells, stem cells and their progenitors to normal levels. It was thus concluded that the abnormalities in enteroendocrine cells and stem cells and their differentiation progenitors may be caused by certain signaling substances produced under inflammatory processes, resulting in changes in hormone expression in enteroendocrine cells. These substances may also interfere with the colonogenic activity and the differentiation of the stem-cell secretory lineage into mature enteroendocrine cells.

Protective effect of isoquercitrin against acute dextran sulfate sodium-induced rat colitis depends on the severity of tissue damage

BACKGROUND

Isoquercitrin (quercetin-3-O-β-d-glucopyranoside) is a flavonoid that exhibited antioxidant and anti-inflammatory activities in a number of in vitro and in vivo studies. Experimental evidence from rodent models of inflammatory bowel disease is, however, lacking. This study was designed to examine whether isoquercitrin effectively and dose-dependently attenuates acute dextran sulfate sodium (DSS)-induced rat colitis.

METHODS

Wistar rats were divided into negative control group (exposed to vehicle only), positive control group (DSS-induced colitis plus vehicle), low isoquercitrin group (DSS pretreated with isoquercitrin 1mg/kg/day) and high isoquercitrin group (DSS with isoquercitrin 10mg/kg/day). Isoquercitrin was administered daily for 14days, and during the last 7days rats drank DSS solution. The effect of isoquercitrin on DSS-induced colitis was assessed clinically (e.g. disease activity index), biochemically (tissue myeloperoxidase activity, local cyclooxygenase-2 expression), using histology (standard hematoxylin-eosin-based histomorphometry, immunohistochemical detection of inducible nitric oxide synthase) and hematology (blood count).

RESULTS

Isoquercitrin dose-dependently ameliorated whole colon shortening and mitigated DSS-induced expression of cyclooxygenase-2 and inducible nitric oxide synthase in the descending segment of the organ. However, when different parts of colon were assessed histomorphometrically, the results did not globally support the protective role of this flavonoid. Tissue healing trends observable in the descending colon were not apparent in the rectum, where histological damage was most severe.

CONCLUSIONS

We surmise that isoquercitrin may be effective in the prevention of acute colitis. Besides being dose-dependent, the potency of orally administered isoquercitrin may depend on the severity of tissue damage and/or on the site of its action.

Chromogranin A and other enteroendocrine markers in inflammatory bowel disease

Changes in the distribution and products of enteroendocrine cells may play a role in immune activation and regulation of gut inflammation. This review aims at critically evaluating the main enteroendocrine markers in inflammatory bowel diseases (IBD). A narrative review was performed by searching inflammatory bowel diseases and enteroendocrine biomarkers in PubMed. Relevant modifications of some enteroendocrine markers, such as Chromogranin A, and their correlation with disease activity have been reported in patients with inflammatory bowel diseases. Even if data about neuroendocrine markers are sometimes contrasting, they may be potentially useful for the diagnosis and clinical management of these patients.

Effects of AP‑1 and NF‑κB inhibitors on colonic endocrine cells in rats with TNBS‑induced colitis

Interactions between intestinal neuroendocrine peptides/amines and the immune system appear to have an important role in the pathophysiology of inflammatory bowel disease (IBD). The present study investigated the effects of activator protein (AP)‑1 and nuclear factor (NF)‑κB inhibitors on inflammation‑induced alterations in enteroendocrine cells. A total of 48 male Wistar rats were divided into the following four groups (n=12 rats/group): Control, trinitrobenzene sulfonic acid (TNBS)‑induced colitis only (TNBS group), TNBS‑induced colitis with 3‑[(dodecylthiocarbonyl)-methyl]-glutarimide (DTCM‑G) treatment (DTCM‑G group), and TNBS‑induced colitis with dehydroxymethylepoxyquinomicin (DHMEQ) treatment (DHMEQ group). A total of 3 days following administration of TNBS, the rats were treated as follows: The control and TNBS groups received 0.5 ml vehicle (0.5% carboxymethyl cellulose; CMC), respectively; the DTCM‑G group received DTCM‑G (20 mg/kg body weight) in 0.5% CMC; and the DHMEQ group received DHMEQ (15 mg/kg body weight) in 0.5% CMC. All injections were performed intraperitoneally twice daily for 5 days. The rats were sacrificed, and tissue samples obtained from the colon were examined histopathologically and immunohistochemically. Inflammation was evaluated using a scoring system. In addition, the sections were immunostained for chromogranin A (CgA), serotonin, peptide YY (PYY), oxyntomodulin, pancreatic polypeptide (PP) and somatostatin, and immunostaining was quantified using image‑analysis software. The density of cells expressing CgA, PYY and PP was significantly lower in the TNBS group compared with in the control group, whereas the density of cells expressing serotonin, oxyntomodulin and somatostatin was significantly higher in the TNBS group compared with in the control group. None of the endocrine cell types differed significantly between the control group and either the DTCM‑G or DHMEQ groups. All of the colonic endocrine cell types were affected in rats with TNBS‑induced colitis. The expression density of these endocrine cell types was restored to control levels following treatment with AP‑1 or NF‑κB inhibitors. These results indicated that the immune system and enteroendocrine cells interact in IBD.

Treatment with novel AP-1 and NF-κB inhibitors restores the colonic endocrine cells to normal levels in rats with DSS-induced colitis

The aim of this study was to determine the effects of two anti-inflammatory agents on the abnormalities in colonic endocrine cells in dextran sodium sulfate (DSS)-induced colitis. Colitis was induced in male Wistar rats (n=45) using DSS; a further 15 rats without colitis were included in a healthy control group. The animals with DSS-induced colitis were randomly divided into 3 treatment groups as follows: i) DSS group, rats were treated with 0.5 ml of 0.5% carboxymethyl cellulose (CMC); ii) DSS‑G group, rats were treated with 3-[(dodecylthiocarbonyl)‑methyl]‑glutarimide (DTCM‑G), a novel activator protein 1 (AP-1) inhibitor, 20 mg/kg in CMC; and iii) DSS‑Q group, rats were treated with dehydroxymethylepoxyquinomicin, a nuclear factor κB (NF-κB) inhibitor, 15 mg/kg in CMC. The treatments were administered intraperitoneally, twice daily for 5 days, after which the animals were sacrificed and tissue samples from the colon were immunostained for chromogranin A (CgA), serotonin, peptide YY (PYY), enteroglucagon, pancreatic polypeptide (PP), somatostatin, leukocytes, B/T lymphocytes, B lymphocytes, T lymphocytes, macrophages/monocytes and mast cells. The densities of these endocrine and immune cells were quantified by computer‑aided image analysis. The densities of CgA-, serotonin-, PYY- and enteroglucagon-producing cells were significantly higher, and those of PP- and somatostatin-producing cells were significantly lower in the DSS‑G, DSS‑Q and control groups than in the DSS group. The densities of all the immune cells were lower in the DSS‑G, DSS‑Q and control groups than in the DSS group. The densities of all endocrine cell types and immune cells in both the DSS groups treated with anti‑inflammatory agents were restored to control levels. In conclusion, our data demonstrate that there is an interaction between endocrine and immune cells during inflammation. This interaction with subsequent changes in endocrine cells is responsible for the clinical manifestation of colitis symptoms.

Effects of anti-inflammatory therapy on bursting pressure of colonic anastomosis in murine dextran sulfate sodium induced colitis

BACKGROUND

The aim of this study was to examine the effect of colitis and anti-inflammatory therapies on the healing of colonic anastomoses in mice.

METHODS

Female C57BL/6 mice were randomized into eight groups; four groups receiving plain tap-water and four groups receiving dextran sulfate sodium. Intra-peritoneal treatment was given therapeutically for 14 days with placebo, prednisolone, azathioprine, or infliximab (IFX). Colonic anastomoses were performed and bursting pressure (BP) measurements were recorded and the inflammation evaluated with histology and zymography.

RESULTS

The mice with colitis had a more active inflammation based on histology and bowel weight compared with the tap water group, 8.3 (7.6-9.5) mg/mm and 5.5 (4.8-6.2) mg/mm respectively (p < 0.0001). Similarly mice with colitis receiving placebo had a more active inflammation, 12.8 (10.6-15.0) mg/mm, which differed significantly from all the other therapy arms among the colitic mice; prednisolone 8.1 (7.5-9.1) mg/mm (p = 0.014), azathioprine 8.2 (7.0-8.5) mg/mm (p = 0.0046), IFX 6.7 (6.4-7.9) mg/mm (p = 0.0055). BP for the placebo group was 90.0 (71.5-102.8) mmHg and did not differ from azathioprine or IFX groups, 84.4 (70.5-112.5) and 92.3 (75.8-122.3) mmHg respectively. In contrast BP for the prednisolone group was significantly decreased compared to placebo, 55.5 (42.8-73.0) mmHg (p = 0.0004).

CONCLUSIONS

All therapies had a beneficial effect on the colitis. An impaired BP of colonic anastomoses was noted after preoperative steroids but not after azathioprine or IFX in this model.

Si Shen Wan Regulates Phospholipase Cγ-1 and PI3K/Akt Signal in Colonic Mucosa from Rats with Colitis

The present study explored the feasible pathway of Si Shen Wan (SSW) in inhibiting apoptosis of intestinal epithelial cells (IECs) by observing activation of phospholipase Cγ-1 (PLC-γ1) and PI3K/Akt signal in colonic mucosa from rats with colitis. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in the Sprague-Dawley rats. After SSW was administrated for 7 days after TNBS infusion, western blot showed an increment in levels of PI3K, p-Akt, and IL-23 and a decrement in levels of PLC-γ1 and HSP70 in colonic mucosal injury induced by TNBS. Meanwhile, assessments by ELISA revealed an increment in concentrations of IL-2, IL-6, and IL-17 and a reduction in level of TGF-β after TNBS challenge. Impressively, treatment with SSW for 7 days significantly attenuated the expressions of PI3K and p-Akt and the secretion of IL-2, IL-6, IL-17, and IL-23 and promoted the activation of PLC-γ1, HSP70, and TGF-β. Our previous studies had demonstrated that SSW restored colonic mucosal ulcers by inhibiting apoptosis of IECs. The present study demonstrated that the effect of SSW on inhibiting apoptosis of IECs was realized probably by activation of PLC-γ1 and suppression of PI3K/Akt signal pathway.

The homeostatic role of neuropeptide Y in immune function and its impact on mood and behaviour

Neuropeptide Y (NPY), one of the most abundant peptides in the nervous system, exerts its effects via five receptor types, termed Y1, Y2, Y4, Y5 and Y6. NPY's pleiotropic functions comprise the regulation of brain activity, mood, stress coping, ingestion, digestion, metabolism, vascular and immune function. Nerve-derived NPY directly affects immune cells while NPY also acts as a paracrine and autocrine immune mediator, because immune cells themselves are capable of producing and releasing NPY. NPY is able to induce immune activation or suppression, depending on a myriad of factors such as the Y receptors activated and cell types involved. There is an intricate relationship between psychological stress, mood disorders and the immune system. While stress represents a risk factor for the development of mood disorders, it exhibits diverse actions on the immune system as well. Conversely, inflammation is regarded as an internal stressor and is increasingly recognized to contribute to the pathogenesis of mood and metabolic disorders. Intriguingly, the cerebral NPY system has been found to protect against distinct disturbances in response to immune challenge, attenuating the sickness response and preventing the development of depression. Thus, NPY plays an important homeostatic role in balancing disturbances of physiological systems caused by peripheral immune challenge. This implication is particularly evident in the brain in which NPY counteracts the negative impact of immune challenge on mood, emotional processing and stress resilience. NPY thus acts as a unique signalling molecule in the interaction of the immune system with the brain in health and disease.

The role of peptide YY in gastrointestinal diseases and disorders (review)

Peptide YY (PYY) is affected in several gastrointestinal diseases and disorders. Changes in PYY appear to be an adaptive response to alterations in pathophysiological conditions caused by the disease. This applies to gastrointestinal diseases/disorders such as irritable bowel syndrome, inflammatory bowel disease, celiac disease, systemic sclerosis, and post-intestinal resection. By contrast, the changes in PYY in chronic idiopathic slow transit constipation (CST) seem to be of a primary nature, and may be one etiological factor of the disease. Abnormalities in PYY seem to contribute to the development of symptoms present in irritable bowel syndrome, inflammatory bowel disease, gastroenteropathy in long-standing diabetes and CST. The changes in PYY could, however, be favorable in some gastrointestinal disorders such as celiac disease, systemic sclerosis and post-intestinal resection state. Investigating changes in PYY in gastrointestinal diseases/disorders could be beneficial in clinical practice, where a receptor agonist or an antagonist can be used as a drug, depending on the condition. Similar to other neuroendocrine peptides/amines of the gut, PYY has broad physiological/pharmacological effects: it can bind to and activate several receptors with independent actions. Thus, in order to use PYY as a drug, receptor-specific agonists or antagonists need to be developed.

Neuropeptide Y, peptide YY and pancreatic polypeptide in the gut-brain axis

The gut-brain axis refers to the bidirectional communication between the gut and the brain. Four information carriers (vagal and spinal afferent neurons, immune mediators such as cytokines, gut hormones and gut microbiota-derived signalling molecules) transmit information from the gut to the brain, while autonomic neurons and neuroendocrine factors carry outputs from the brain to the gut. The members of the neuropeptide Y (NPY) family of biologically active peptides, NPY, peptide YY (PYY) and pancreatic polypeptide (PP), are expressed by cell systems at distinct levels of the gut-brain axis. PYY and PP are exclusively expressed by endocrine cells of the digestive system, whereas NPY is found at all levels of the gut-brain and brain-gut axis. The major systems expressing NPY comprise enteric neurons, primary afferent neurons, several neuronal pathways throughout the brain and sympathetic neurons. In the digestive tract, NPY and PYY inhibit gastrointestinal motility and electrolyte secretion and in this way modify the input to the brain. PYY is also influenced by the intestinal microbiota, and NPY exerts, via stimulation of Y1 receptors, a proinflammatory action. Furthermore, the NPY system protects against distinct behavioural disturbances caused by peripheral immune challenge, ameliorating the acute sickness response and preventing long-term depression. At the level of the afferent system, NPY inhibits nociceptive input from the periphery to the spinal cord and brainstem. In the brain, NPY and its receptors (Y1, Y2, Y4, Y5) play important roles in regulating food intake, energy homeostasis, anxiety, mood and stress resilience. In addition, PP and PYY signal to the brain to attenuate food intake, anxiety and depression-related behaviour. These findings underscore the important role of the NPY-Y receptor system at several levels of the gut-brain axis in which NPY, PYY and PP operate both as neural and endocrine messengers.

High densities of serotonin and peptide YY cells in the colon of patients with lymphocytic colitis

AIM: To investigate colonic endocrine cells in lymphocytic colitis (LC) patients.

METHODS: Fifty-seven patients with LC were included. These patients were 41 females and 16 males, with an average age of 49 years (range 19-84 years). Twenty-seven subjects that underwent colonoscopy with biopsies were used as controls. These subjects underwent colonoscopy because of gastrointestinal bleeding or health worries, where the source of bleeding was identified as haemorrhoids or angiodysplasia. They were 19 females and 8 males with an average age of 49 years (range 18-67 years). Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. Biopsies were fixed in 4% buffered paraformaldehyde, embedded in paraffin and cut into 5 μm-thick sections. The sections immunostained by the avidin-biotin-complex method for serotonin, peptide YY (PYY), pancreatic polypeptide (PP) enteroglucagon and somatostatin cells. The cell densities were quantified by computerised image analysis using Olympus software.

RESULTS: The colon of both the patient and the control subjects were macroscopically normal. Histopathological examination of colon biopsies from controls revealed normal histology. All patients fulfilled the diagnosis criteria required for of LC: an increase in intraepithelial lymphocytes (> 20 lymphocytes/100 epithelial cells) and surface epithelial damage with increased lamina propria plasma cells and absent or minimal crypt architectural distribution. In the colon of both patients and control subjects, serotonin-, PYY-, PP-, enteroglucagon- and somatostatin-immunoreactive cells were primarily located in the upper part of the crypts of Lieberkühn. These cells were basket- or flask-shaped. There was no statistically significant difference between the right and left colon in controls with regards to the densities of serotonin- and PYY-immunoreactive cells (P = 0.9 and 0.1, respectively). Serotonin cell density in the right colon in controls was 28.9 ± 1.8 and in LC patients 41.6 ± 2.6 (P = 0.008). In the left colon, the corresponding figures were 28.5 ± 1.9 and 42.4 ± 2.9, respectively (P = 0.009). PYY cell density in the right colon of the controls was 10.1 ± 1 and of LC patients 41 ± 4 (P = 0.00006). In the left colon, PYY cell density in controls was 6.6 ± 1.2 and in LC patients 53.3 ± 4.6 (P = 0.00007).

CONCLUSION: The change in serotonin cells could be caused by an interaction between immune cells and serotonin cells, and that of PYY density might be secondary.

Effect of enteral nutrition on dextran sulfate sodium-induced colitis in rats

OBJECTIVE

To study the effect of enteral nutrition (EN) on dextran sulfate sodium (DSS)-induced colitis in rats.

METHODS

Eighty-four Sprague-Dawley rats were divided into 7 groups (12 rats in each group). The blank control group was given ordinary laboratory feed and drinking water. The experimental groups received 5% DSS as drinking water for 7 days. Of the experimental groups, the model control group received ordinary laboratory feed, protein based enteral nutrition (PEN) was fed in the PEN group, while other groups received ordinary laboratory feed plus 5-aminosalicylic acid (5-ASA), methyl-prednisolone, Lactobacillus or glutamine, respectively. On the 8th day, all the rats were sacrificed. Inflammatory scores were assessed from colonic mucosa. Blood culture from inferior vena cava, fecal culture and secretary immunoglobulin-A (S-IgA) levels from colonic contents were determined.

RESULTS

Colon inflammatory scores of Lactobacillus, PEN, glutamine and drug-treated groups were lower than that of the model control group (P < 0.01). The ratios of bacteria translocation in the EN (PEN, Lactobacillus and glutamine) groups were lower than that in the model control group (P < 0.0083). Fecal Lactobacilli in the Lactobacillus and glutamine groups were higher than that in the model control group (P < 0.05). S-IgA levels in colonic contents of the PEN and 5-ASA group were lower than that in the model control group (P < 0.05).

CONCLUSIONS

EN is an effective therapy for treating DDS-induced colitis. EN could alleviate damage, promote the repair of colonic epithelial cells and inhibit bacterial translocation. Lactobacillus and glutamine could also increase the Lactobacilli in colon.

Sex-dependent control of murine emotional-affective behaviour in health and colitis by peptide YY and neuropeptide Y

BACKGROUND AND PURPOSE

Peptide YY (PYY) and neuropeptide Y (NPY) are involved in regulating gut and brain function. Because gastrointestinal inflammation is known to enhance anxiety, we explored whether experimental colitis interacts with genetic deletion (knockout) of PYY and NPY to alter emotional-affective behaviour.

EXPERIMENTAL APPROACH

Male and female wild-type, NPY (NPY(-/-) ), PYY (PYY(-/-) ) and NPY(-/-) ; PYY(-/-) double knockout mice were studied in the absence and presence of mild colitis induced by ingestion of dextran sulphate sodium (2%) in drinking water. Anxiety-like behaviour was tested on the elevated plus maze and open field, and depression-like behaviour assessed by the forced swim test.

KEY RESULTS

In the absence of colitis, anxiety-like behaviour was increased by deletion of NPY but not PYY in a test- and sex-dependent manner, while depression-like behaviour was enhanced in NPY(-/-) and PYY(-/-) mice of either sex. The severity of DSS-induced colitis, assessed by colonic myeloperoxidase content, was attenuated in NPY(-/-) but not PYY(-/-) mice. Colitis modified anxiety- and depression-related behaviour in a sex-, genotype- and test-related manner, and knockout experiments indicated that NPY and PYY were involved in some of these behavioural effects of colitis.

CONCLUSIONS AND IMPLICATIONS

These data demonstrate sex-dependent roles of NPY and PYY in regulation of anxiety- and depression-like behaviour in the absence and presence of colitis. Like NPY, the gut hormone PYY has the potential to attenuate depression-like behaviour but does not share the ability of NPY to reduce anxiety-like behaviour.

Amelioration of dextran sulfate sodium-induced chronic colitis by sulfasalazine salicylazosulfapyridine via reducing NF-kappaB transcription factor p65 recruitment to ICAM-1 gene promoters

Sulfasalazine salicylazosulfapyridine (SASP), consisting of 5-aminosalicylic acid bound to sulfapyridine by a diazo bond, is an effective drug in the treatment of inflammatory bowel diseases (IBD). However, its mechanism of action remains a matter of debate. The objective of our work was to investigate SASP's effect on NF-kappaB signal transduction pathway in transcriptional regulation level. Repeated colitis was induced by administration of 4 cycles of 4% dextran sulfate sodium (DSS); The severity of colitis was assessed on the basis of clinical signs, colon length, and histology scores. Moreover, sIgA and haptoglobin (HP) were analyzed by enzyme linked immunosorbent assay, and ICAM-1 gene expression was analyzed by quantitative reverse transcriptase real-time polymerase chain reaction (qRT-PCR) using SYBA green I. NF-kappaB signal transduction proteins and transcriptional factor p65 interaction with promoter of ICAM-1 were assessed by western blotting and chromatin immunoprecipitation assay. SASP administration significantly attenuated the colitis signs and caused substantial reductions of HP expression, and maintained the level of cecum sIgA. SASP inhibited ICAM-1 gene expression and had no effect on MIF gene expression. Also, SASP was able to reduce p-IkBalpha protein expression; however, no change in the activation of IKKalpha, IKKbeta, p65, and IKBalpha was noted. SASP inhibited p65 recruitment to the gene ICAM-1 promoter. In conclusion, inhibition of NF-kappaB pathway signal proteins and blockade of p65 binding to gene ICAM-1 promoter might explain the effect and mechanisms of SASP at alleviating DSS-induced colitis in mice.