Gut mesenchymal stromal cells in immunity

Mesenchymal stromal cells (MSCs), first found in bone marrow (BM), are the structural architects of all organs, participating in most biological functions. MSCs possess tissue-specific signatures that allow their discrimination according to their origin and location. Among their multiple functions, MSCs closely interact with immune cells, orchestrating their activity to maintain overall homeostasis. The phenotype of tissue MSCs residing in the bowel overlaps with myofibroblasts, lining the bottom walls of intestinal crypts (pericryptal) or interspersed within intestinal submucosa (intercryptal). In Crohn’s disease, intestinal MSCs are tightly stacked in a chronic inflammatory milieu, which causes their enforced expression of Class II major histocompatibility complex (MHC). The absence of Class II MHC is a hallmark for immune-modulator and tolerogenic properties of normal MSCs and, vice versa, the expression of HLA-DR is peculiar to antigen presenting cells, that is, immune-activator cells. Interferon gamma (IFN) is responsible for induction of Class II MHC expression on intestinal MSCs. The reversal of myofibroblasts/MSCs from an immune-modulator to an activator phenotype in Crohn’s disease results in the formation of a fibrotic tube subverting the intestinal structure. Epithelial metaplastic areas in this context can progress to dysplasia and cancer

Increased HMGB1 expression and release by mononuclear cells following surgical/anesthesia trauma

Introduction: High mobility group box 1 (HMGB1) is a key mediator of inflammation that is actively secreted by macrophages and/or passively released from damaged cells. The proinflammatory role of HMGB1 has been demonstrated in both animal models and humans, since the severity of inflammatory response is strictly related to serum HMGB1 levels in patients suffering from traumatic insult, including operative trauma. This study was undertaken to investigate HMGB1 production kinetics in patients undergoing major elective surgery and to address how circulating mononuclear cells are implicated in this setting. Moreover, we explored the possible relationship between HMGB1 and the proinflammatory cytokine interleukin-6 (IL-6). Methods: Forty-seven subjects, American Society of Anesthesiologists physical status I and II, scheduled for major abdominal procedures, were enrolled. After intravenous medication with midazolam (0.025 mg/Kg), all patients received a standard general anesthesia protocol, by thiopentone sodium (5 mg/Kg) and fentanyl (1.4 mu g/Kg), plus injected Vecuronium (0.08 mg/Kg). Venous peripheral blood was drawn from patients at three different times, t(0): before surgery, t(1): immediately after surgical procedure; t(2): at 24 hours following intervention. Monocytes were purified by incubation with anti-CD14-coated microbeads, followed by sorting with a magnetic device. Cellular localization of HMGB1 was investigated by flow cytometry assay; HMGB1 release in the serum by Western blot. Serum samples were tested for IL-6 levels by ELISA. A one-way repeated-measures analysis ANOVA was performed to assess differences in HMGB1 concentration over time, in monocytes and serum. Results: We show that: a) cellular expression of HMGB1 in monocytes at t(1) was significantly higher as compared to t(0); b) at t(2), a significant increase of HMGB1 levels was found in the sera of patients. Such an increase was concomitant to a significant down-regulation of cellular HMGB1, suggesting that the release of HMGB1 might partially derive from mononuclear cells; c) treatment of monocytes with HMGB1 induced in vitro the release of IL-6; d) at t(2), high amounts of circulating IL-6 were detected as compared to t(0). Conclusions: This study demonstrates for the first time that surgical/anesthesia trauma is able to induce an early intracellular upregulation of HMGB1 in monocytes of surgical patients, suggesting that HMGB1 derives, at least partially, from monocytes

Imaging Modalities for the Diagnosis of Vascular Graft Infections:A Consensus Paper amongst Different Specialists

Vascular graft infection (VGI) is a rare but severe complication of vascular surgery that is associated with a bad prognosis and high mortality rate. An accurate and prompt identification of the infection and its extent is crucial for the correct management of the patient. However, standardized diagnostic algorithms and a univocal consensus on the best strategy to reach a diagnosis still do not exist. This review aims to summarize different radiological and Nuclear Medicine (NM) modalities commonly adopted for the imaging of VGI. Moreover, we attempt to provide evidence-based answers to several practical questions raised by clinicians and surgeons when they approach imaging in order to plan the most appropriate radiological or NM examination for their patients

Effect of miR-204&211 and RUNX2 control on the fate of human mesenchymal stromal cells

MiR-204 and 211 enforced expression in murine mesenchymal stromal cells (MSCs) has been shown to induce adipogenesis and impair osteogenesis, through RUNX2 down-modulation. This mechanism has been suggested to play a role in osteoporosis associated with obesity. However, two further fundamental MSC functions, chondrogenesis and hematopoietic supporting activity, have not yet been explored. To this end, we transduced, by a lenti-viral vector, miR-204 and 211 in a model primary human MSC line, opportunely chosen among our MSC collection for displaying all properties of canonical bone marrow MSCs, except adipogenesis. Enforced expression of miR-204&211 in these cells, rescued adipogenesis, and inhibited osteogenesis, as previously reported in murine MSCs, but, surprisingly, also damaged cartilage formation and hematopoietic supporting activity, which were never explored before. RUNX2 has been previously indicated as the target of miR-204&211, whose down modulation is responsible for the switch from osteogenesis to adipogenesis. However, the additional disruption of chondrogenesis and hematopoietic supporting activity, which we report here, might depend on diverse miR-204&211 targets. To investigate this hypothesis, permanent RUNX2 knock-down was performed. Sh-RUNX2 fully reproduced the phenotypes induced by miR-204&211, confirming that RUNX2 down modulation is the major event leading to the reported functional modification on our MSCs. It seems thus apparent that RUNX2, a recognized master gene for osteogenesis, might rule all four MSC commitment and differentiation processes. Hence, the formerly reported role of miR204&211 and RUNX2 in osteoporosis and obesity, coupled with our novel observation showing inhibition of cartilage differentiation and hematopoietic support, strikingly resemble the clinical traits of metabolic syndrome, where osteoarthritis, osteoporosis, anaemia and obesity occur together. Our observations, corroborating and extending previous observations, suggest that miR-204&211-RUNX2 axis in human MSCs is possibly involved in the pathogenesis of this rapidly growing disease in industrialized countries, for possible therapeutic intervention to regenerate former homeostasis

Imaging Modalities for the Diagnosis of Vascular Graft Infections: A Consensus Paper amongst Different Specialists

Vascular graft infection (VGI) is a rare but severe complication of vascular surgery that is associated with a bad prognosis and high mortality rate. An accurate and prompt identification of the infection and its extent is crucial for the correct management of the patient. However, standardized diagnostic algorithms and a univocal consensus on the best strategy to reach a diagnosis still do not exist. This review aims to summarize different radiological and Nuclear Medicine (NM) modalities commonly adopted for the imaging of VGI. Moreover, we attempt to provide evidence-based answers to several practical questions raised by clinicians and surgeons when they approach imaging in order to plan the most appropriate radiological or NM examination for their patients

Multidisciplinary management of neuroendocrine neoplasia: a real-world experience from a referral center

Purpose: Multidisciplinary approach is widely advised for an effective care of patients with neuroendocrine neoplasia (NEN). Since data on efficacy of multidisciplinary management of NENs patients in referral centers are scanty, this study aimed at analyzing the modality of presentation and clinical outcome of patients with NENs managed by a dedicated multidisciplinary team. Methods. In this prospective observational study, we included all consecutive new patients visiting the Sant'Andrea Hospital in Rome (ENETS-Center of Excellence) between January 2014 and June 2018. Results. A total of 195 patients were evaluated. The most frequent sites were pancreas (38.5%), small bowel (22%), and lung (9.7%). Median Ki67 was 3%. After the first visit at the center, additional radiological and/or nuclear medicine procedures were requested in 163 patients (83.6%), whereas histological data revision was advised in 84 patients (43.1%) (revision of histological slides: 27.7%, new bioptic sampling: 15.4%). After that, disease imaging staging and grading was modified in 30.7% and 17.9% of patients, respectively. Overall, a change in therapeutic management was proposed in 98 patients (50.3%). Conclusions. Multidisciplinary approach in a dedicated team may lead to change of disease imaging staging and grading in a significant proportion of patients. Enhancing referral routes to dedicated-NEN center should be promoted, since it may improve patients' clinical outcome

A spatial multi-scale fluorescence microscopy toolbox discloses entry checkpoints of SARS-CoV-2 variants in Vero E6 cells

: We exploited a multi-scale microscopy imaging toolbox to address some major issues related to SARS-CoV-2 interactions with host cells. Our approach harnesses both conventional and super-resolution fluorescence microscopy and easily matches the spatial scale of single-virus/cell checkpoints. After its validation through the characterization of infected cells and virus morphology, we leveraged this toolbox to reveal subtle issues related to the entry phase of SARS-CoV-2 variants in Vero E6 cells. Our results show that in Vero E6 cells the B.1.1.7 strain (aka Alpha Variant of Concern) is associated with much faster kinetics of endocytic uptake compared to its ancestor B.1.177. Given the cell-entry scenario dominated by the endosomal "late pathway", the faster internalization of B.1.1.7 could be directly related to the N501Y mutation in the S protein, which is known to strengthen the binding of Spike receptor binding domain with ACE2. Remarkably, we also directly observed the central role of clathrin as a mediator of endocytosis in the late pathway of entry. In keeping with the clathrin-mediated endocytosis, we highlighted the non-raft membrane localization of ACE2. Overall, we believe that our fluorescence microscopy-based approach represents a fertile strategy to investigate the molecular features of SARS-CoV-2 interactions with cells

Inhibition of DNA methylation sensitizes glioblastoma for tumor necrosis factor-related apoptosis-inducing ligand-mediated destruction

Life expectancy of patients affected by glioblastoma multiforme is extremely low. The therapeutic use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been proposed to treat this disease based on its ability to kill glioma cell lines in vitro and in vivo. Here, we show that, differently from glioma cell lines, glioblastoma multiforme tumors were resistant to TRAIL stimulation because they expressed low levels of caspase-8 and high levels of the death receptor inhibitor PED/PEA-15. Inhibition of methyltransferases by decitabine resulted in considerable up-regulation of TRAIL receptor-1 and caspase-8, down-regulation of PED/PEA-15, inhibition of cell growth, and sensitization of primary glioblastoma cells to TRAIL-induced apoptosis. Exogenous caspase-8 expression was the main event able to restore TRAIL sensitivity in primary glioblastoma cells. The antitumor activity of decitabine and TRAIL was confirmed in vivo in a mouse model of glioblastoma multiforme. Evaluation of tumor size, apoptosis, and caspase activation in nude mouse glioblastoma multiforme xenografts showed dramatic synergy of decitabine and TRAIL in the treatment of glioblastoma, whereas the single agents were scarcely effective in terms of reduction of tumor mass, apoptosis induction, and caspase activation. Thus, the combination of TRAIL and demethylating agents may provide a key tool to overcome glioblastoma resistance to therapeutic treatments. ©2005 American Association for Cancer Research