Epstein–Barr virus replication linked to B cell proliferation in inflamed areas of colonic mucosa of patients with inflammatory bowel disease

BackgroundInflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. Epstein–Barr virus (EBV) infection is associated with increased disease severity in therapeutically immunosuppressed IBD patients. The role of EBV infection in patients with IBD who are unresponsive to medical therapy is unclear. Anti-viral strategies may be a viable treatment option if severity of EBV infection, reflected in peripheral blood, contributes to IBD progression.ObjectivesWe investigated the role of EBV in IBD patients unresponsive to medical therapy by examining EBV reactivation and B-cell proliferation in colonic mucosa.Study designEBV DNA copy numbers were measured by real-time PCR in peripheral blood mononuclear cells (PBMC) of 84 patients with IBD and 115 non-IBD controls in a retrospective cross-sectional study. EBV-infected cells in colonic mucosa were identified by immunohistochemistry.ResultsEBV load in PBMC was higher in patients with IBD than in non-IBD controls, especially in patients not responding to medication. Inflamed colonic mucosa of these patients had high levels of expression of lytic and latent EBV genes that localized to proliferating B-lymphocytes, which was not seen in patients responding to therapy.ConclusionsEBV replication was associated with severe IBD and mucosal inflammation. Increased proliferation and EBV infection of B-lymphocytes in inflamed colonic mucosa highlight the potential role of EBV in mucosal inflammation. The immunomodulatory effects of EBV could delay the resolution of the IBD associated inflammation, thus contributing to disease progression. These results indicate that anti-viral therapeutic strategies for the resolution of IBD may be useful.     

Retinoic acid increases the cellular cholesterol predominantly in a mTOR-independent manner

Retinoic acid (RA) plays a role in the mounting immune response and controls several functions of the human body, including cholesterol homeostasis. The synthesis, uptake, and efflux of cellular cholesterol are significantly linked to the mammalian target of rapamycin complex-1 (mTORC1). Activation of mTORC1 promotes the synthesis and uptake of the cholesterol and suppresses its efflux, thus causing accumulation of cellular cholesterol. It is intriguing to know the effect of a high dose of RA on cholesterol accumulation in macrophages (mφ) and whether it is via mTOR activation. It is important to note that the long-term treatment of RA in humans is safe. Therefore, we chose a high dose of RA to observe its effect, which may be implicated in diseases like visceral leishmaniasis, where cholesterol deficiency is established. In the present study, we found the increased expression of RAPTOR, a regulatory component of the mTORC1 complex, in mφ upon treatment with RA. We observed the increased expression of SREBP2, LDLR, and PCSK9 in RA-treated mφ under sufficient cholesterol conditions, which further increased cellular cholesterol levels. Notably, their expressions were decreased when the mTOR pathway was inhibited by rapamycin. However, treatment with rapamycin did not result in the loss of cellular cholesterol in RA-treated mφ. Comparison with rapamycin-treated mφ suggests that RA induces cellular cholesterol levels in a mTORC1-independent manner.

     

Conduction system examination in a case of spontaneous heart block in a dog

This is a serial-section study of the conduction system in a 2-year-old boxer with electrocardiographic evidence of complete A-V block. The following findings were present: a lack of communication between the atria and the A-V node, atrophy of the A-V node, and tenuous connections between the A-V node and the A-V bundle. These were accompanied by acute degenerative changes in the conduction system. These changes are considered to be the result of arteriolosclerotic heart disease.     

Antagonism of P2Y₁₂ reduces physiological thromboxane levels

Antiplatelet therapy for the management of patients with cardiovascular risks often includes a combination therapy of aspirin and clopidogrel, acting through inhibition of thromboxane generation and blockade of G(i)-coupled P2Y?? receptor, respectively. We hypothesized that ADP acting through P2Y?? regulates physiological thromboxane levels. The serum thromboxane levels in mice (n?=?3) dosed with clopidogrel and prasugrel were decreased by 83.1?±?5.3% and 94.26?±?1.75% respectively compared to untreated mice. Pre-treatment of human blood (n?=?3) ex vivo with active metabolites of clopidogrel or prasugrel led to a reduction in thromboxane levels to 16.3?±?3.2% and 4.9?±?0.8% respectively, compared to untreated human serum. We also evaluated serum thromboxane levels in P2Y receptor null mice (n?=?4). Whereas serum thromboxane levels in P2Y? null mice were similar to those in wild type littermates, those in the P2Y?? null mice were inhibited by 83.15?±?3.8%. Finally, in a pilot study, serum thromboxane levels were reduced by 76.05?±?8.41% in healthy human volunteers (n?=?6) upon dosing with clopidogrel, compared to the levels before dosing. In conclusion, P2Y?? antagonism alone can decrease physiological thromboxane levels. Thus, this study could pave way the for newer/modified treatment regimens for the management of patients with thrombotic complications who are allergic or non-responsive to aspirin.     

Live bacterial cells as orally delivered therapeutics

Despite the swift escalation in research regarding the use of live bacterial cells for therapeutic purposes, the prophylactic and curative use of probiotic microorganisms still remains a wide and controversial field. In addition, the acknowledgement that live bacterial cells can be genetically engineered to synthesise products that have therapeutic potential has generated substantial interest among clinicians and health professionals. Clinical trials have increasingly provided an insightful scientific derivation for the use of live bacterial cells in medicinal practice in diseases such as diarrhoea, cancer, Crohn's disease, enhancement of the host's immune response, and numerous other diseases. A key constraint in the use of live bacterial cells, however, is the complexity of delivering them to the correct target sites. Oral delivery of free live cells, lyophilised cells and immobilised cells has been attempted, but with restricted success, chiefly because bacterial cells are unable to survive passage through the gastrointestinal tract in sufficient dosage. On many occasions, when given orally, these cells have been found to provoke immunogenic responses that are undesirable. Recent studies show that these problems can be overcome by delivering live bacterial cells using artificial cell microcapsules. This review abridges recent developments in the therapeutic use of live bacterial cells, addresses the potential and restrictions for their application in therapy, and provides insights into the future course of this emerging therapy.     

Novel nitric oxide producing probiotic wound healing patch: preparation and in vivo analysis in a New Zealand white rabbit model of ischaemic and infected wounds

The treatment of chronic wounds poses a significant challenge for clinicians and patients alike. Here we report design and preclinical efficacy of a novel nitric oxide gas (gNO)-producing probiotic patch for wound healing. Specifically, a wound healing patch using lactic acid bacteria in an adhesive gas permeable membrane has been designed and investigated for treating ischaemic and infected full-thickness dermal wounds in a New Zealand white rabbit model for ischaemic wound healing. Kaplan-Meier survival curves showed increased wound closure with gNO-producing patch-treated wounds over 21 days of therapy (log-rank P = 0·0225 and Wilcoxon P = 0·0113). Cox proportional hazard regression showed that gNO-producing patch-treated wounds were 2·52 times more likely to close compared with control patches (hazard P = 0·0375, score P = 0·032 and likelihood ratio P = 0·0355), and histological analysis showed improved wound healing in gNO-producing patch-treated animals. This study may provide an effective, safe and less costly alternative for treating chronic wounds.