Novel Biomarkers for Inflammatory Bowel Disease and Colorectal Cancer: An Interplay between Metabolic Dysregulation and Excessive Inflammation.

Persistent inflammation can trigger altered epigenetic, inflammatory, and bioenergetic states. Inflammatory bowel disease (IBD) is an idiopathic disease characterized by chronic inflammation of the gastrointestinal tract, with evidence of subsequent metabolic syndrome disorder. Studies have demonstrated that as many as 42% of patients with ulcerative colitis (UC) who are found to have high-grade dysplasia, either already had colorectal cancer (CRC) or develop it within a short time. The presence of low-grade dysplasia is also predictive of CRC. Many signaling pathways are shared among IBD and CRC, including cell survival, cell proliferation, angiogenesis, and inflammatory signaling pathways. Current IBD therapeutics target a small subset of molecular drivers of IBD, with many focused on the inflammatory aspect of the pathways. Thus, there is a great need to identify biomarkers of both IBD and CRC, that can be predictive of therapeutic efficacy, disease severity, and predisposition to CRC. In this study, we explored the changes in biomarkers specific for inflammatory, metabolic, and proliferative pathways, to help determine the relevance to both IBD and CRC. Our analysis demonstrated, for the first time in IBD, the loss of the tumor suppressor protein Ras associated family protein 1A (RASSF1A), via epigenetic changes, the hyperactivation of the obligate kinase of the NOD2 pathogen recognition receptor (receptor interacting protein kinase 2 [RIPK2]), the loss of activation of the metabolic kinase, AMP activated protein kinase (AMPKα1), and, lastly, the activation of the transcription factor and kinase Yes associated protein (YAP) kinase, that is involved in proliferation of cells. The expression and activation status of these four elements are mirrored in IBD, CRC, and IBD-CRC patients and, importantly, in matched blood and biopsy samples. The latter would suggest that biomarker analysis can be performed non-invasively, to understand IBD and CRC, without the need for invasive and costly endoscopic analysis. This study, for the first time, illustrates the need to understand IBD or CRC beyond an inflammatory perspective and the value of therapeutics directed to reset altered proliferative and metabolic states within the colon. The use of such therapeutics may truly drive patients into remission.

Colitis induced by dextran sulphate sodium causes histopathological and immunological changes in the periodontal tissues of Wistar rats.

OBJECTIVE: This study investigated the impact of colitis induced by dextran sulphate sodium (DSS)-induced colitis (DIC) on histopathological and immunological outcomes in the periodontal tissues of Wistar rats. BACKGROUND: Inflammatory bowel diseases (IBD) and periodontitis have been reported to present a bidirectional relationship. However, the inflammatory pathway that connects both diseases needs further investigation. MATERIAL AND METHODS: Twenty-five male Wistar rats were allocated in four groups: unilateral ligature-induced periodontitis for 14 days: LIP (n = 7); dextran sulphate sodium-induced colitis only: DIC (n = 6); DIC + LIP (n = 6) and controls (n = 6). Digital images were obtained from the histological sections. In order to assess the attachment loss (AL), the linear distance between the cementoenamel junction (CEJ) and the alveolar bone crest was measured on the mesial root using histological photomicrography's ImageJ software. Immunological analyses of gingival tissues and plasma were performed by Bio-Plex Th1/Th2 Assay. RESULTS: The DIC group showed inflammatory cells extending to the periodontal connective tissues, which contained significantly elevated expressions of IL-1α, IL-1ß, IL-2, IL-6, IL-12, IL-13, GM-CSF, IFN-γ and TNF-α compared to controls. There was no significant difference in bone loss between controls and DIC. There were no significant histopathological differences between DIC + LIP and LIP. However, DIC + LIP presented a significantly lower IL-2 and IL-5 than the LIP group. There was no bone loss difference between LIP+DIC and LIP groups. DIC + LIP group presented significantly higher levels of GM-CSF in plasma. CONCLUSION: DSS-induced colitis was associated with an overexpression of Th1/Th2- related cytokines in the gingival tissue.

ILB®, a Low Molecular Weight Dextran Sulphate, Restores Glutamate Homeostasis, Amino Acid Metabolism and Neurocognitive Functions in a Rat Model of Severe Traumatic Brain Injury.

In a previous study, we found that administration of ILB®, a new low molecular weight dextran sulphate, significantly improved mitochondrial functions and energy metabolism, as well as decreased oxidative/nitrosative stress, of brain tissue of rats exposed to severe traumatic brain injury (sTBI), induced by the closed-head weight-drop model of diffused TBI. Using aliquots of deproteinized brain tissue of the same animals of this former study, we here determined the concentrations of 24 amino acids of control rats, untreated sTBI rats (sacrificed at 2 and 7 days post-injury) and sTBI rats receiving a subcutaneous ILB® administration (at the dose levels of 1, 5 and 15 mg/kg b.w.) 30 min post-impact (sacrificed at 2 and 7 days post-injury). Additionally, in a different set of experiments, new groups of control rats, untreated sTBI rats and ILB®-treated rats (administered 30 min after sTBI at the dose levels of 1 or 5 mg/kg b.w.) were studied for their neurocognitive functions (anxiety, locomotor capacities, short- and long-term memory) at 7 days after the induction of sTBI. Compared to untreated sTBI animals, ILB® significantly decreased whole brain glutamate (normalizing the glutamate/glutamine ratio), glycine, serine and γ-aminobutyric acid. Furthermore, ILB® administration restored arginine metabolism (preventing nitrosative stress), levels of amino acids involved in methylation reactions (methionine, L-cystathionine, S-adenosylhomocysteine), and N-acetylaspartate homeostasis. The macroscopic evidences of the beneficial effects on brain metabolism induced by ILB® were the relevant improvement in neurocognitive functions of the group of animals treated with ILB® 5 mg/kg b.w., compared to the marked cognitive decline measured in untreated sTBI animals. These results demonstrate that ILB® administration 30 min after sTBI prevents glutamate excitotoxicity and normalizes levels of amino acids involved in crucial brain metabolic functions. The ameliorations of amino acid metabolism, mitochondrial functions and energy metabolism in ILB®-treated rats exposed to sTBI produced significant improvement in neurocognitive functions, reinforcing the concept that ILB® is a new effective therapeutic tool for the treatment of sTBI, worth being tested in the clinical setting.

Up-regulation of miR-24-1-5p is involved in the chemoprevention of colorectal cancer by black raspberry anthocyanins.

As important epigenetic regulators, microRNA regulate protein expression by triggering the degradation of target mRNA and/or by inhibiting their translation. Dysregulation of microRNA expression has been reported in several cancers, including colorectal cancer. In this study, microRNA-array differential analysis revealed strongly enhanced expression of miR-24-1-5p in the colon tissue of azoxymethane/dextran sulphate sodium-induced mice that were fed with black raspberry anthocyanins for 9 weeks. Overexpression of miR-24-1-5p in human colorectal cancer cells significantly repressed ß-catenin expression, and simultaneously decreased cell proliferation, migration and survival. Furthermore, miR-24-1-5p could target ß-catenin and trigger a negative regulatory loop for ß-catenin and its downstream target genes. ß-Catenin signalling is vital to the formation and progression of human colorectal cancer. The current findings therefore identified miR-24-1-5p as a potent regulator of ß-catenin, and this may provide a novel chemopreventive and therapeutic strategy for ß-catenin signalling-driven colorectal cancer.

Wheat gluten intake increases the severity of experimental colitis and bacterial translocation by weakening of the proteins of the junctional complex.

Gluten is only partially digested by intestinal enzymes and can generate peptides that can alter intestinal permeability, facilitating bacterial translocation, thus affecting the immune system. Few studies addressed the role of diet with gluten in the development of colitis. Therefore, we investigate the effects of wheat gluten-containing diet on the evolution of sodium dextran sulphate (DSS)-induced colitis. Mice were fed a standard diet without (colitis group) or with 4·5 % wheat gluten (colitis + gluten) for 15 d and received DSS solution (1·5 %, w/v) instead of water during the last 7 d. Compared with the colitis group, colitis + gluten mice presented a worse clinical score, a larger extension of colonic injury area, and increased mucosal inflammation. Both intestinal permeability and bacterial translocation were increased, propitiating bacteria migration for peripheral organs. The mechanism by which diet with gluten exacerbates colitis appears to be related to changes in protein production and organisation in adhesion junctions and desmosomes. The protein α-E-catenin was especially reduced in mice fed gluten, which compromised the localisation of E-cadherin and ß-catenin proteins, weakening the structure of desmosomes. The epithelial damage caused by gluten included shortening of microvilli, a high number of digestive vacuoles, and changes in the endosome/lysosome system. In conclusion, our results show that wheat gluten-containing diet exacerbates the mucosal damage caused by colitis, reducing intestinal barrier function and increasing bacterial translocation. These effects are related to the induction of weakness and disorganisation of adhesion junctions and desmosomes as well as shortening of microvilli and modification of the endocytic vesicle route.

Human filarial proteins attenuate chronic colitis in an experimental mouse model.

Encouraged by our earlier results of promising therapeutic effect of filarial recombinant proteins BmALT2, BmCys and WbL2 individually in the mouse model of acute ulcerative colitis, in this study, these proteins have been explored individually and in different combinations for their therapeutic potential in dextran sulphate sodium (DSS)-induced chronic colitis mice. These mice, treated with filarial proteins, showed reduced disease parameters including body weight loss, disease activity index, macroscopic and histopathological scores of colon and myeloperoxidase activity in colonic mucosa. Among various treatment schemes, rBmALT2 + rBmCys which showed most pronounced therapeutic implication was found to downregulate the mRNA expressions of IFN-γ and TNF-α and upregulate IL-10 and TGF-ß expression in the splenocytes. Also, increase in level of IgG1 and IgG2a isotypes in the sera of rBmALT2 + rBmCys-treated colitis mice was noted. Activated NF-κB level was found to be reduced in the colon of treated colitis mice compared to untreated one. In conclusion, filarial proteins in combination have been shown to improve the clinicopathologic status of chronic colitis through suppression of pro-inflammatory immune response most possibly in NF-κB-dependent manner. We propose this therapeutic strategy to be tested further to be considered as an effective option in chronic colitis.

Dextran sulphate sodium (DSS) causes intestinal histopathology and inflammatory changes consistent with increased gut leakiness in chickens.

1. The clinical severity, histological changes, indicators of gut leakiness and inflammatory cytokine profiles were studied in chickens with dextran sulphate sodium (DSS)-induced intestinal inflammation. 2. The experimental groups (1.25%, 1.5% and 2.5% DSS) showed clinical signs, such as loose stools and weight loss, which increased with additional treatment days and, as expected, the effects of DSS-induced intestinal inflammation were time and dose-dependent. 3. After 10 d, histological manifestations were evident, including goblet cell depletion, mucus layer loss, significantly shorter villi and a thinner total ileal mucosa. 4. The d(-)-lactate value, which was used as a gut leakiness indicator, was significantly increased in the 2.5% DSS group. 5. Expression of the inflammatory cytokines interleukin-1Beta, tumour necrosis factor alpha and interleukin-10 in the serum significantly increased with DSS treatment. 6. This study indicates that the experimental intestinal inflammation induced by DSS is an ideal model to study the pathogenic mechanisms of intestinal inflammation in chickens and to test the efficacy of therapies.

[Changes of intestinal mucosal barrier in mice with chronic ulcerative colitis].

Objective: To study the damage and mechanism of intestinal mucosal barrier function in mice with ulcerative colitis induced by Dextran sulphate sodium (DSS). Methods: Mice models of chronic ulcerative colitis induced by DSS were established. The mice were completely randomized into normal control group and DSS group, 25 mice in each group. The body weight and colon length of the mice were monitored. The pathological examination of colon tissue was confirmed the success of the model and assessed the integrity of the colonic mucosal barrier; Evan's Blue's intestinal permeability analysis assessed the function of colon mucosal barrier; immunofluorescence staining and Western blot were used to evaluate the expression of intestinal mucosal barrier integrity-related proteins. Results: Compared with the normal control group, the DSS group had lower body weight [(25.6±0.7)g vs (23.5±0.7)g, t=2.14, P<0.05], and the colon length was shorter [(7.3±0.4)cm vs (5.6±0.2)cm, t=3.975, P<0.001]; colonic pathological results showed that the intestinal mucosa became thinner and part of the intestinal mucosa was defective; Evan's Blue instilled into the intestinal lumen was more abundant into the intestinal mucosa, and the optical density at 620 nm (OD(620))/colon tissue weight (g) was higher [(0.11±0.01) vs (0.15±0.01), t=4.174, P<0.05]; immunofluorescence and Western blot results showed lower expression of ZO-1, Claudin-1, and F-actin in colonic mucosa. Conclusion: The structure and function of intestinal mucosal barrier in DSS-induced chronic ulcerative colitis mice is impaired.

Amelioration of experimental colitis after short-term therapy with glucocorticoid and its relationship to the induction of different regulatory markers.

The clinical benefits of short-term therapy with glucocorticoids (GC) in patients with inflammatory bowel disease (IBD) are widely known. However, the effects of this treatment towards the re-establishment of the regulatory network in IBD are not fully explored. We have evaluated the immunological effects of the abbreviated GC therapy in experimental colitis induced by 3% dextran sulphate sodium in C57BL/6 mice. Treatment with GC improved disease outcome, constrained circulating leucocytes and ameliorated intestinal inflammation. The control of the local inflammatory responses involved a reduction in the expression of interferon-γ and interleukin-1ß, associated with augmented mRNA levels of peroxisome proliferator-activated receptors (α and γ) in intestine. Furthermore, there was a reduction of CD4+ T cells producing interferon-γ, together with an increased frequency of the putative regulatory population of T cells producing interleukin-10, in spleen. These systemic alterations were accompanied by a decrease in the proliferative potential of splenocytes of mice treated in vivo with GC. Notably, treatment with GC also led to an increase in the frequency of the regulatory markers GITR, CTLA-4, PD-1, CD73 and FoxP3, more prominently in spleen. Taken together, our results pointed to a role of GC in the control of leucocyte responsiveness and re-establishment of a regulatory system, which probably contributed to disease control and the restoration of immune balance. Finally, this is the first time that GC treatment was associated with the modulation of a broad number of regulatory markers in an experimental model of colitis.

Chitosan-dextran sulphate nanoparticles for GnRH release in rabbit insemination extenders.

This study was designed to develop chitosan (CS)-dextran sulphate (DS) nanoparticles containing a GnRH analogue and to study their effect on rabbit (Oryctolagus cuniculus) semen quality. Six experimental extenders were tested as follows: (control) Tris-citric acid-glucose (TCG), (1) 0.05% CS-0.05% DS (4:1), (2) 0.1% CS-0.05% DS (4:1), (3) 0.05% CS-0.05% DS (3:1), (4) 0.1% CS-0.05% DS (3:1), (5) 0.1% CS-0.05% DS (2:1). CS and DS were dissolved in TCG medium, and nanoparticles were obtained through magnetic stirring. Rabbit seminal samples were incubated up to 5 hr at 37°C in the extenders, and seminal quality was evaluated. The entrapment efficiency was 40%-50%. After 5 hr at 37°C, a 20% of the hormone was released. Results showed that the presence of CS-DS nanoparticles did not affect rabbit semen motility, viability and membrane functionality; however, acrosome integrity was significantly higher versus control (p < .001).

Analysing the effect of I1 imidazoline receptor ligands on DSS-induced acute colitis in mice.

Imidazoline receptors (IRs) have been recognized as promising targets in the treatment of numerous diseases; and moxonidine and rilmenidine, agonists of I1-IRs, are widely used as antihypertensive agents. Some evidence suggests that IR ligands may induce anti-inflammatory effects acting on I1-IRs or other molecular targets, which could be beneficial in patients with inflammatory bowel disease (IBD). On the other hand, several IR ligands may stimulate also alpha2-adrenoceptors, which were earlier shown to inhibit, but in more recent studies to rather aggravate colitis. Hence, this study aimed to analyse for the first time the effect of various I1-IR ligands on intestinal inflammation. Colitis was induced in C57BL/6 mice by adding dextran sulphate sodium (DSS) to the drinking water for 7 days. Mice were treated daily with different IR ligands: moxonidine and rilmenidine (I1-IR agonists), AGN 192403 (highly selective I1-IR ligand, putative antagonist), efaroxan (I1-IR antagonist), as well as with the endogenous IR agonists agmatine and harmane. It was found that moxonidine and rilmenidine at clinically relevant doses, similarly to the other IR ligands, do not have a significant impact on the macroscopic and histological signs of DSS-evoked inflammation. Likewise, colonic myeloperoxidase and serum interleukin-6 levels remained unchanged in response to these agents. Thus, our study demonstrates that imidazoline ligands do not influence significantly the severity of DSS-colitis in mice and suggest that they probably neither affect the course of IBD in humans. However, the translational value of these findings needs to be verified with other experimental colitis models and human studies.

NF-κB1, NF-κB2 and c-Rel differentially regulate susceptibility to colitis-associated adenoma development in C57BL/6 mice.

NF-κB signalling is an important factor in the development of inflammation-associated cancers. Mouse models of Helicobacter-induced gastric cancer and colitis-associated colorectal cancer have demonstrated that classical NF-κB signalling is an important regulator of these processes. In the stomach, it has also been demonstrated that signalling involving specific NF-κB proteins, including NF-κB1/p50, NF-κB2/p52, and c-Rel, differentially regulate the development of gastric pre-neoplasia. To investigate the effect of NF-κB subunit loss on colitis-associated carcinogenesis, we administered azoxymethane followed by pulsed dextran sodium sulphate to C57BL/6, Nfkb1(-/-), Nfkb2(-/-), and c-Rel(-/-) mice. Animals lacking the c-Rel subunit were more susceptible to colitis-associated cancer than wild-type mice, developing 3.5 times more colonic polyps per animal than wild-type mice. Nfkb2(-/-) mice were resistant to colitis-associated cancer, developing fewer polyps per colon than wild-type mice (median 1 compared to 4). To investigate the mechanisms underlying these trends, azoxymethane and dextran sodium sulphate were administered separately to mice of each genotype. Nfkb2(-/-) mice developed fewer clinical signs of colitis and exhibited less severe colitis and an attenuated cytokine response compared with all other groups following DSS administration. Azoxymethane administration did not fully suppress colonic epithelial mitosis in c-Rel(-/-) mice and less colonic epithelial apoptosis was also observed in this genotype compared to wild-type counterparts. These observations demonstrate different functions of specific NF-κB subunits in this model of colitis-associated carcinogenesis. NF-κB2/p52 is necessary for the development of colitis, whilst c-Rel-mediated signalling regulates colonic epithelial cell turnover following DNA damage.

Impact of dextran sulphate sodium-induced colitis on the intestinal transport of the colon carcinogen PhIP.

Colorectal cancer is one of the most frequent cancers in Western countries. Chronic intestinal diseases such as Crohn's disease and ulcerative colitis, in which the intestinal barrier is massively disturbed, significantly raise the risk of developing a colorectal tumour. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a genotoxic heterocyclic aromatic amine that is formed after strongly heating fish and meat. In this study, the hypothesis that PhIP uptake in the gut is increased during chronic colitis was tested. Chronic colitis was induced by oral administration of dextran sulphate sodium (DSS) to Fischer 344 rats. The transport of PhIP in eight different rat intestinal segments was examined in Ussing chambers. The tissues were incubated with 10 µM PhIP for 90 min, and the concentration of PhIP was determined in the mucosal and serosal compartments of the Ussing chambers as well as in the clamped tissues by LC-MS. Although chronic colitis was clearly induced in the rats, no differences in the intestinal transport of PhIP were observed between control and DSS-treated animals. The hypothesis that in the course of chronic colitis more PhIP is taken up by the intestinal epithelium, thereby increasing the risk of developing colorectal cancer, could not be confirmed in the present report.

Beneficial effects of live and dead Salmonella-based vector strain on the course of colitis in mice.

Dysbiosis of intestinal microbiota and hyperactive immune responses seem to be crucial for the uncontrolled inflammation in inflammatory bowel diseases (IBD). Modulation of the microbiome and immune stimulation of the intestinal epithelium were suggested as therapeutic approaches. In this study, live attenuated and dead bacterial cells of Salmonella Typhimurium SL7207 - a widely used bacterial vector for gene therapy were administered in DSS-induced colitis in mice. C57BL/6 mice were divided into four groups. The first group received pure water (CTRL). The other three groups received 2% dextran sulphate sodium (DSS) to induce colitis. Two DSS groups were treated with live attenuated (DSS live) or inactivated (DSS dead) Salmonella by gastric gavage. Intake of 2% DSS caused weight loss in all DSS groups compared to control mice with some improvement in DSS live group on the last day of the experiment. Significantly longer colon and improved stool consistency were reported in DSS live group, but not DSS dead group, when compared with DSS. Significant enlargement of spleens was observed only in DSS and DSS dead groups compared to control. Significant differences in stool consistency, colon length and spleen enlargement were observed between DSS live and DSS dead groups with beneficial effects of live bacteria. Interestingly, significant decrease in myeloperoxidase activity was detected in both, DSS live and DSS dead groups compared to the DSS group. On the basis of these results, progression of colitis seems to be beneficially influenced not only by live attenuated but to some extent also by inactivated Salmonella Typhimurium SL7207. Our results provide evidence that Salmonella-based gene therapy vectors are able to positively alter gut homeostasis during DSS-induced colitis. SIGNIFICANCE AND IMPACT OF THE STUDY: Restoration of gut homeostasis has a great importance in IBD. Here, we tested the nonspecific effect of the strain Salmonella Typhimurium SL7207 on the course of colitis to find out whether the potential effect would be mediated by activity of live bacterial cells or by bacterial structures that are also present in dead bacteria. Live bacterial therapy of colitis showed a beneficial effect on clinical signs as well as on macroscopic and inflammatory markers of colitis. On the other hand, therapy with dead bacteria showed inconsistent effects, negative in most clinical outcomes, positive especially in myeloperoxidase activity. Our data indicate that the beneficial effect of bacterial gene therapy vectors carrying therapeutic genes might be, at least partially, caused by the bacterial vector instead of the therapeutic gene.

Effects of arachidonic acid intake on inflammatory reactions in dextran sodium sulphate-induced colitis in rats.

The aim of this study was to investigate the effects of the administration of oral arachidonic acid (AA) in rats with or without dextran sulphate sodium (DSS)-induced inflammatory bowel disease. Male Wistar rats were administered AA at 0, 5, 35 or 240 mg/kg daily by gavage for 8 weeks. Inflammatory bowel disease was induced by replacing drinking water with 3 % DSS solution during the last 7 d of the AA dosing period. These animals passed loose stools, diarrhoea and red-stained faeces. Cyclo-oxygenase-2 concentration and myeloperoxidase activity in the colonic tissue were significantly increased in the animals given AA at 240 mg/kg compared with the animals given AA at 0 mg/kg. Thromboxane B2 concentration in the medium of cultured colonic mucosae isolated from these groups was found to be dose-dependently increased by AA, and the increase was significant at 35 and 240 mg/kg. Leukotriene B4 concentration was also significantly increased and saturated at 5 mg/kg. In addition, AA at 240 mg/kg promoted DSS-induced colonic mucosal oedema with macrophage infiltration. In contrast, administration of AA for 8 weeks, even at 240 mg/kg, showed no effects on the normal rats. These results suggest that in rats with bowel disease AA metabolism is affected by oral AA, even at 5 mg/kg per d, and that excessive AA may aggravate inflammation, whereas AA shows no effects in rats without inflammatory bowel disease.

Rice prolamin extract ameliorates acute murine colitis by inhibiting nuclear factor-kappa B and modulating intestinal apoptosis and cell proliferation.

We investigated the impact of rice prolamin extract (RPE) on lipopolysaccharide (LPS)-induced nuclear factor (NF)-κB signalling in intestinal epithelial cells and macrophages, and determined the therapeutic efficacy of RPE in acute murine colitis. The effect of RPE on LPS-induced NF-κB signalling and proinflammatory gene expression was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in-vivo efficacy of RPE was assessed in mice with 3% dextran sulphate sodium (DSS)-induced colitis. Apoptotic and cellular proliferative activities were evaluated by immunostaining with cleaved caspase-3 and proliferating cell nuclear antigen (PCNA) antibodies. RPE inhibited LPS-induced expression of monocyte chemotactic protein (MCP)-1, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha and LPS-induced NF-κB signalling in intestinal epithelial cells and macrophages. RPE-fed, DSS-exposed mice showed less weight loss, longer colon length and lower histological score compared to control diet-fed, DSS-exposed mice. Immunostaining analysis revealed a significant decrease of cleaved caspase-3 positive cells in RPE-fed, DSS-exposed mice compared to DSS-exposed mice. Also, the number of PCNA-positive cells within intact colonic crypts decreased significantly in RPE-fed, DSS-exposed mice compared to control diet-fed, DSS-exposed mice. DSS-induced NF-κB signalling was inhibited by RPE. RPE ameliorates intestinal inflammation by inhibiting NF-κB activation and modulating intestinal apoptosis and cell proliferation in an acute murine colitis.

A novel approach for antibody nanocarriers development through hydrophobic ion-pairing complexation.

IgG-Fab fragment, a model antibody protein was hydrophobically modified by a novel approach of ion-pairing complexation. Three different sulphated ion-pairing agents were utilised including sodium dodecyl sulphate, taurocholic acid and dextran sulphate (DS). The formations of hydrophobic ion-pairing (HIP) complexes were dependant on pH and molar ratio of ion-pairing agent to Fab. Aqueous solubilities of HIP complexes were very low compared to Fab alone. In particular, when dextran sulphate was added as ion-pairing agent, formed Fab:DS HIP complexes were least soluble in water. Further, nanoparticles (NPs) loaded with drug and Fab:DS HIP complex were prepared and characterised with respect to encapsulation efficiency and size. We observed significant improvement in encapsulation efficiency for Fab:DS HIP complex-loaded nanoparticles. This study demonstrates a novel approach of formulating antibody-loaded nanoparticles which can also be employed for delivery of large antibodies.

MTG16 contributes to colonic epithelial integrity in experimental colitis.

OBJECTIVE: The myeloid translocation genes (MTGs) are transcriptional corepressors with both Mtg8(-/-) and Mtgr1(-/-) mice showing developmental and/or differentiation defects in the intestine. We sought to determine the role of MTG16 in intestinal integrity. METHODS: Baseline and stress induced colonic phenotypes were examined in Mtg16(-/-) mice. To unmask phenotypes, we treated Mtg16(-/-) mice with dextran sodium sulphate (DSS) or infected them with Citrobacter rodentium and the colons were examined for ulceration and for changes in proliferation, apoptosis and inflammation. RESULTS: Mtg16(-/-) mice have altered immune subsets, suggesting priming towards Th1 responses. Mtg16(-/-) mice developed increased weight loss, diarrhoea, mortality and histological colitis and there were increased innate (Gr1(+), F4/80(+), CD11c(+) and MHCII(+); CD11c(+)) and Th1 adaptive (CD4) immune cells in Mtg16(-/-) colons after DSS treatment. Additionally, there was increased apoptosis and a compensatory increased proliferation in Mtg16(-/-) colons. Compared with wild-type mice, Mtg16(-/-) mice exhibited increased colonic CD4;IFN-γ cells in vehicle-treated and DSS-treated mice. Adoptive transfer of wild-type marrow into Mtg16(-/-) recipients did not rescue the Mtg16(-/-) injury phenotype. Isolated colonic epithelial cells from DSS-treated Mtg16(-/-) mice exhibited increased KC (Cxcl1) mRNA expression when compared with wild-type mice. Mtg16(-/-) mice infected with C rodentium had more severe colitis and greater bacterial colonisation. Last, MTG16 mRNA levels were reduced in human ulcerative colitis versus normal colon tissues. CONCLUSIONS: These observations indicate that MTG16 is critical for colonocyte survival and regeneration in response to intestinal injury and provide evidence that this transcriptional corepressor regulates inflammatory recruitment in response to injury.

Subclinical peripheral inflammation has systemic effects impacting central nervous system proteome in budgerigars.

Regulation of neuroimmune interactions varies across avian species. Little is presently known about the interplay between periphery and central nervous system (CNS) in parrots, birds sensitive to neuroinflammation. Here we investigated the systemic and CNS responses to dextran sulphate sodium (DSS)- and lipopolysaccharide (LPS)-induced subclinical acute peripheral inflammation in budgerigar (Melopsittacus undulatus). Three experimental treatment groups differing in DSS and LPS stimulation were compared to controls. Individuals treated with DSS showed significant histological intestinal damage. Through quantitative proteomics we described changes in plasma (PL) and cerebrospinal fluid (CSF) composition. In total, we identified 180 proteins in PL and 978 proteins in CSF, with moderate co-structure between the proteomes. Between treatments we detected differences in immune, coagulation and metabolic pathways. Proteomic variation was associated with the levels of pro-inflammatory cytokine mRNA expression in intestine and brain. Our findings shed light on systemic impacts of peripheral low-grade inflammation in birds.

Celastrol nano-emulsions selectively regulate apoptosis of synovial macrophage for alleviating rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune inflammation. Excessive proliferation and inadequate apoptosis of synovial macrophages are the crucial events of RA. Therefore, delivering therapeutic molecules to synovial macrophages specifically to tackle apoptotic insufficiency probably can be an efficient way to reduce joint inflammation and bone erosion. Based on the characteristics of dextran sulphate (DS) specifically binding scavenger receptor A (SR-A) on macrophage and celastrol (CLT) inducing apoptosis, we designed synovial macrophage-targeted nano-emulsions encapsulated with CLT (SR-CLTNEs) and explored their anti-RA effect. After intravenous injection, fluorescence-labelled SR-CLTNEs successfully targeted inflammatory joints and synovial macrophages in a mouse model of RA, with the macrophage targeting efficiency of SR-CLTNEs, CLTNEs and free DID was 20.53%, 13.93% and 9.8%, respectively. In vivo and in vitro studies showed that SR-CLTNEs effectively promoted the apoptosis of macrophages, reshaped the balance between apoptosis and proliferation, and ultimately treated RA in a high efficiency and low toxicity manner. Overall, our work demonstrates the efficacy of using SR-CLTNEs as a novel nanotherapeutic approach for RA therapy and the great translational potential of SR-CLTNEs.