An epithelial Nfkb2 pathway exacerbates intestinal inflammation by supplementing latent RelA dimers to the canonical NF-κB module.

Aberrant inflammation, such as that associated with inflammatory bowel disease (IBD), is fueled by the inordinate activity of RelA/NF-κB factors. As such, the canonical NF-κB module mediates controlled nuclear activation of RelA dimers from the latent cytoplasmic complexes. What provokes pathological RelA activity in the colitogenic gut remains unclear. The noncanonical NF-κB pathway typically promotes immune organogenesis involving Nfkb2 gene products. Because NF-κB pathways are intertwined, we asked whether noncanonical signaling aggravated inflammatory RelA activity. Our investigation revealed frequent engagement of the noncanonical pathway in human IBD. In a mouse model of experimental colitis, we established that Nfkb2-mediated regulations escalated the RelA-driven proinflammatory gene response in intestinal epithelial cells, exacerbating the infiltration of inflammatory cells and colon pathologies. Our mechanistic studies clarified that cell-autonomous Nfkb2 signaling supplemented latent NF-κB dimers, leading to a hyperactive canonical RelA response in the inflamed colon. In sum, the regulation of latent NF-κB dimers appears to link noncanonical Nfkb2 signaling to RelA-driven inflammatory pathologies and may provide for therapeutic targets.

NCoR1: Putting the Brakes on the Dendritic Cell Immune Tolerance.

Understanding the mechanisms fine-tuning immunogenic versus tolerogenic balance in dendritic cells (DCs) is of high importance for therapeutic approaches. We found that NCoR1-mediated direct repression of the tolerogenic program in conventional DCs is essential for induction of an optimal immunogenic response. NCoR1 depletion upregulated a wide variety of tolerogenic genes in activated DCs, which consequently resulted in increased frequency of FoxP3+ regulatory T cells. Mechanistically, NCoR1 masks the PU.1-bound super-enhancers on major tolerogenic genes after DC activation that are subsequently bound by nuclear factor-κB. NCoR1 knockdown (KD) reduced RelA nuclear translocation and activity, whereas RelB was unaffected, providing activated DCs a tolerogenic advantage. Moreover, NCoR1DC-/- mice depicted enhanced Tregs in draining lymph nodes with increased disease burden upon bacterial and parasitic infections. Besides, adoptive transfer of activated NCoR1 KD DCs in infected animals showed a similar phenotype. Collectively, our results demonstrated NCoR1 as a promising target to control DC-mediated immune tolerance.

Immune Differentiation Regulator p100 Tunes NF-κB Responses to TNF.

Tumor necrosis factor (TNF) is a pleiotropic cytokine whose primary physiological function involves coordinating inflammatory and adaptive immune responses. However, uncontrolled TNF signaling causes aberrant inflammation and has been implicated in several human ailments. Therefore, an understanding of the molecular mechanisms underlying dynamical and gene controls of TNF signaling bear significance for human health. As such, TNF engages the canonical nuclear factor kappa B (NF-κB) pathway to activate RelA:p50 heterodimers, which induce expression of specific immune response genes. Brief and chronic TNF stimulation produces transient and long-lasting NF-κB activities, respectively. Negative feedback regulators of the canonical pathway, including IκBα, are thought to ensure transient RelA:p50 responses to short-lived TNF signals. The non-canonical NF-κB pathway mediates RelB activity during immune differentiation involving p100. We uncovered an unexpected role of p100 in TNF signaling. Brief TNF stimulation of p100-deficient cells triggered an additional late NF-κB activity consisting of RelB:p50 heterodimers, which modified the TNF-induced gene-expression program. In p100-deficient cells subjected to brief TNF stimulation, RelB:p50 not only sustained the expression of a subset of RelA-target immune response genes but also activated additional genes that were not normally induced by TNF in WT mouse embryonic fibroblasts (MEFs) and were related to immune differentiation and metabolic processes. Despite this RelB-mediated distinct gene control, however, RelA and RelB bound to mostly overlapping chromatin sites in p100-deficient cells. Repeated TNF pulses strengthened this RelB:p50 activity, which was supported by NF-κB-driven RelB synthesis. Finally, brief TNF stimulation elicited late-acting expressions of NF-κB target pro-survival genes in p100-deficient myeloma cells. In sum, our study suggests that the immune-differentiation regulator p100 enforces specificity of TNF signaling and that varied p100 levels may provide for modifying TNF responses in diverse physiological and pathological settings.

The NF-κB Activating Pathways in Multiple Myeloma.

Multiple myeloma(MM), an incurable plasma cell cancer, represents the second most prevalent hematological malignancy. Deregulated activity of the nuclear factor kappaB (NF-κB) family of transcription factors has been implicated in the pathogenesis of multiple myeloma. Tumor microenvironment-derived cytokines and cancer-associated genetic mutations signal through the canonical as well as the non-canonical arms to activate the NF-κB system in myeloma cells. In fact, frequent engagement of both the NF-κB pathways constitutes a distinguishing characteristic of myeloma. In turn, NF-κB signaling promotes proliferation, survival and drug-resistance of myeloma cells. In this review article, we catalog NF-κB activating genetic mutations and microenvironmental cues associated with multiple myeloma. We then describe how the individual canonical and non-canonical pathways transduce signals and contribute towards NF-κB -driven gene-expressions in healthy and malignant cells. Furthermore, we discuss signaling crosstalk between concomitantly triggered NF-κB pathways, and its plausible implication for anomalous NF-κB activation and NF-κB driven pro-survival gene-expressions in multiple myeloma. Finally, we propose that mechanistic understanding of NF-κB deregulations may provide for improved therapeutic and prognostic tools in multiple myeloma.

Administration of Adult Human Bone Marrow-Derived, Cultured, Pooled, Allogeneic Mesenchymal Stromal Cells in Critical Limb Ischemia Due to Buerger's Disease: Phase II Study Report Suggests Clinical Efficacy.

Critical limb ischemia (CLI) due to Buerger's disease is a major unmet medical need with a high incidence of morbidity. This phase II, prospective, nonrandomized, open-label, multicentric, dose-ranging study was conducted to assess the efficacy and safety of i.m. injection of adult human bone marrow-derived, cultured, pooled, allogeneic mesenchymal stromal cells (BMMSC) in CLI due to Buerger's disease. Patients were allocated to three groups: 1 and 2 million cells/kg body weight (36 patients each) and standard of care (SOC) (18 patients). BMMSCs were administered as 40-60 injections in the calf muscle and locally, around the ulcer. Most patients were young (age range, 38-42 years) and ex-smokers, and all patients had at least one ulcer. Both the primary endpoints-reduction in rest pain (0.3 units per month [SE, 0.13]) and healing of ulcers (11% decrease in size per month [SE, 0.05])-were significantly better in the group receiving 2 million cells/kg body weight than in the SOC arm. Improvement in secondary endpoints, such as ankle brachial pressure index (0.03 [SE, 0.01] unit increase per month) and total walking distance (1.03 [SE, 0.02] times higher per month), were also significant in the group receiving 2 million cells/kg as compared with the SOC arm. Adverse events reported were remotely related or unrelated to BMMSCs. In conclusion, i.m. administration of BMMSC at a dose of 2 million cells/kg showed clinical benefit and may be the best regimen in patients with CLI due to Buerger's disease. However, further randomized controlled trials are required to confirm the most appropriate dose. Stem Cells Translational Medicine 2017;6:689-699.

Cardiac myxoma: A surgical experience of 38 patients over 9 years, at SSKM hospital Kolkata, India.

BACKGROUND: Cardiac myxoma is the most common benign intracardiac tumor. We studied its clinical presentation, morbidity, mortality and recurrence following surgery over a period of 9 years. MATERIALS AND METHODS: This study was performed at cardiothoracic and vascular surgery department of a tertiary level hospital of eastern India, Seth Sukhlal Karnani Memorial hospital, Institute of Post Graduate Medical Education and Research Kolkata. Near 6000 cardiac cases were operated at our center over this period. Preoperative diagnosis was made with clinical presentation and preoperative echocardiography. Complete tumor excision was done and all patients were followed up for recurrence and complications. RESULT: A total of 38 cases of cardiac myxoma were operated over a period from October 2002 to October 2011. Cardiac myxoma constituted about 0.6% of all cardiac cases operated at our institute. This most commonly presented at fifth decade of life. Of these, 35 cases were left atrial and 2 cases were right atrial, and 1 case was having both atrial involvements. The left atrial myxoma mostly presented as mitral stenosis and very few presented with embolic and constitutional symptoms. No death or recurrence was observed during the follow up period. CONCLUSION: Cardiac myxomas form a very small percentage of the cardiac cases. A high index of suspicion is essential for diagnosis. Echocardiography is the ideal diagnostic tool as also for follow-up. Immediate surgical treatment is indicated in all patients. Cardiac myxomas can be excised with a low rate of mortality and morbidity.

Hydatid lung disease: an analysis of five years cumulative data from Kolkata.

BACKGROUND AND OBJECTIVE: There is scarcity of clinical data regarding hydatid lung disease from Indian subcontinent. In this retrospective study we analyzed the cumulative data over five year's period from two tertiary care hospitals of Kolkata to determine the presentation, treatment and outcome of hydatid disease of lung. METHOD: We analyzed 106 patients on the basis of clinical findings, radiological findings [chest X-ray--PA and lateral view, CT scan of thorax and upper abdomen, ultrasonography (USG) of thorax and upper abdomen] and serological test IgG ELISA (enzyme linked immunosorbent assay) against echinococcus granulosus antigen along with the mode of diagnosis, indications and types of surgery, and outcome of treatment with chemotherapy (albendazole), surgery and combined surgery with chemotherapy. RESULT: There was female preponderance with median age of presentation 33 years with interquartile range of 7. At the time of diagnosis 14.15% patients were asymptomatic. Cough was the commonest symptom (73.58%) followed by chest pain (54.72%). Single sharply demarcated round or oval homogenous opacity was the commonest radiological sign (81.13%). Complicated cysts such as lung abscess, pleural involvement, pneumonitis and fibrosis were noted in 10.38%, 13.21%, 7.55% and 11.32% cases respectively. We found that serological test was only 77.01% sensitive. Eighty-two (86.32%) patients underwent surgery, and 56.10% of them received additional chemotherapy with albendazole. The types of operation performed were pericystectomy (in 91.46% cases), lobectomy (in 6.10% cases) and pneumonectomy (in 2.44% cases). Perioperative mortality was nil but morbidity was found in 10.98% cases with empyema (8.54%), the commonest complication. Thirteen inoperable patients were treated with albendazole, among them 8 showed reduction of cyst-size, 3 showed no change and 2 patients showed obliteration of cyst. CONCLUSION: Surgery is a safe and effective way of treatment for thoracic hydatid cyst along with perioperative albendazole therapy. There is a scope for chemotherapy with albendazole in inoperable cases.

Effect of magnesium infusion on thoracic epidural analgesia.

INTRODUCTION: Patients of lung volume reduction surgery (LVRS) having an ASA status III or more are likely to be further downgraded by surgery to critical levels of pulmonary function. AIM: To compare the efficacy of thoracic epidural block with (0.125%) bupivacaine, fentanyl combination and (0.125%) bupivacaine, fentanyl combination with adjunctive intravenous magnesium infusion for the relief of postoperative pain in patients undergoing LVRS. METHODS: Patients were operated under general anesthesia. Thirty minutes before the anticipated completion of skin closure in both groups, (Group A and Group B) 7 ml of (0.125%) bupivacaine calculated as 1.5 ml/thoracic segment space for achieving analgesia in dermatomes of T4, T5, T6, T7, and T8 segments, along with fentanyl 50 µg (0.5 ml), was administered through the catheter, activating the epidural block, and the time was noted. Thereafter, in patients of Group A, magnesium sulfate injection 30 mg/kg i.v. bolus was followed by infusion of magnesium sulfate at 10 mg/kg/hr and continued up to 24 hours. Group B was treated as control. RESULTS AND ANALYSIS: A significant increase in the mean and maximum duration of analgesia in Group A in comparison with Group B (P<0.05) was observed. Total epidural dose of fentanyl and bupivacaine required in Group A was significantly lower in comparison with Group B in 24 hours. DISCUSSION: Requirement of total doses of local anesthetics along with opioids could be minimized by magnesium infusion; therefore, the further downgradation of patients of LVRS may be prevented. CONCLUSION: Intravenous magnesium can prolong opioid-induced analgesia while minimizing nausea, pruritus, and somnolence.

Surgical outcome in thymic tumors with myasthenia gravis after plasmapheresis--a comparative study.

Plasmapheresis has been used widely in the treatment of myasthenia gravis and also in symptomatic thymectomized patients with short-term clinical improvement. But the utility of preoperative plasmapheresis in the outcome has not been widely studied. The authors analyzed its impact in the surgical outcome of thymic tumors with myasthenia gravis. We studied a total of 19 patients, who were operated on in the period from January 2000 to July 2006 for thymic tumors with myasthenia gravis. Of these 19 patients, preoperative plasmapheresis was performed in 10 patients (group B) and the remaining nine patients (group A) had no preoperative plasmapheresis based on risk factors for requirement of postoperative ventilation. Outcome in the form of requirement of ventilation, symptomatic improvement, hospital stay and requirement of drugs were assessed at the end of one year and compared between the two groups. Six out of nine patients (67%) in group A required ventilatory support in the immediate postoperative period, whereas two out of ten patients (20%) in group B required it. Significant and sustained symptomatic improvement was noted in group B as compared with group A (P<0.01). Preoperative plasmapheresis in the patients of thymic tumors with myasthenia gravis is beneficial and can cause a significant difference in the postoperative outcome.

Double chambered right ventricle and congenital complete heart block: a unique association.

Double chambered right ventricle, an uncommon congenital heart disease, is commonly associated with VSD. Here a rare and unique association with congenital complete heart block is reported for the first time.