Lower Oligocene thrust-system in the epi-Ligurian succession: evidence from the Enza Valley (northern Apennines, Italy)

Abstract Within the lower part (Upper Eocene-Oligocene) of the epi-Ligurian succession, outcropping in the Emilian side of the northern Apennines (Enza Valley), duplications by thrust tectonics were recognized through the systematic integration of field geology with calcareous nannofossil biostratigraphy. This thrust system, derived from the overthrusting of two thrust-sheets over a footwall, is unconformably overlain by a Rupelian succession. The thrust structure of the Enza Valley, affected by a subsequent wide overturned syncline together vith the unconformable succession, shows a remarkable Lower Oligocene contractional tectonics, previously not recognized in the northern Apennines. The comparison of this thrust system with other outcropping areas of the epi-Ligurian succession makes probable the wide-spread occurrence of the Lower Oligocene tectonics in the uppermost structural levels of the chain (epi-Ligurian domain). In a regional tectonic framework, the Rupelian thrust tectonics affecting the epi-Ligurian succession can be related to the Lower Oligocene closure of the innermost portion of the Subligurian basin (Aveto-Petrignacola Formation) due to the NE-verging overthrusting of the External Ligurian Units. In this context the unconformable succession of the Enza Valley seems correlable with the basal portion of the Subligurian Eratica Sandstone (Rupelian-Chattian) which unconformably overlies a deformed substratum (Mesoalpine Phase)

Endothelin Receptors Expressed by Immune Cells Are Involved in Modulation of Inflammation and in Fibrosis: Relevance to the Pathogenesis of Systemic Sclerosis

open13noEndothelin-1 (ET-1) plays a pivotal role in vasoconstriction, fibrosis, and inflammation, the key features of systemic sclerosis (SSc). ET-1 receptors (ETA and ETB) are expressed on endothelial cells, smooth muscle cells, and fibroblasts, but their presence on immune cells has not been deeply investigated so far. Endothelin receptors antagonists such as bosentan have beneficial effects on vasoconstriction and fibrosis, but less is known about their potential anti-inflammatory effects. We studied the expression of ET-1 receptors on immune cells (T and B lymphocytes, monocytes, and neutrophils) and the link between ET-1 and inflammation in patients with SSc. We show here that ET-1 exerts a proinflammatory effect in CD4+ T cells, since it induces an increased IFN-γ production; preincubation with antagonists of both receptors reduces IFN-γ production. Moreover, following ET-1 stimulation, neutrophils produce proinflammatory mediators, thus amplifying the effects of activated CD4+ T cells. Our data indicate that ET-1 system is involved in the pathogenesis of inflammation and fibrosis typical of SSc, through the activation of T lymphocytes and neutrophils and the consequent release of proinflammatory and profibrotic cytokines. These findings suggest that dual ET-1 receptors antagonist therapy, besides its effect on vasculopathy, has a profound impact on the immune system favouring antiinflammatory and antifibrogenic effects.openElisa, Tinazzi; Antonio, Puccetti; Giuseppe, Patuzzo; Alessandro, Barbieri; Giuseppe, Argentino; Federico, Confente; Marzia, Dolcino; Ruggero, Beri; Giacomo, Marchi; Andrea, Ottria; Daniela, Righetti; Mariaelisa, Rampudda; Claudio, LunardiTinazzi, Elisa; Puccetti, Antonio; Patuzzo, Giuseppe; Barbieri, Alessandro; Argentino, Giuseppe; Confente, Federico; Dolcino, Marzia; Beri, Ruggero; Marchi, Giacomo; Ottria, Andrea; Righetti, Daniela; Rampudda, Mariaelisa; Lunardi, Claudi

Epidemiology, management, and outcome of carbapenem-resistant Klebsiella pneumoniae bloodstream infections in hospitals within the same endemic metropolitan area

In the last decade, carbapenem-resistant Klebsiella pneumoniae (CR-Kp) has become endemic in several countries, including Italy. In the present study, we assessed the differences in epidemiology, management, and mortality of CR-Kp bloodstream infection (BSI) in the three main adult acute-care hospitals of the metropolitan area of Genoa, Italy.From January 2013 to December 2014, all patients with CR-Kp BSI were identified through the computerized microbiology laboratory databases of the three hospitals. The primary endpoints of the study were incidence and characteristics of CR-Kp BSI in hospitals within the same endemic metropolitan area. Secondary endpoints were characteristics of CR-Kp BSI in hospitals with and without internal infectious diseases consultants (IDCs) and 15-day mortality.During the study period, the incidence of healthcare-associated CR-Kp BSI in the entire study population was 1.35 episodes per 10,000 patient-days, with substantial differences between the three hospitals. Patients admitted to the two hospital with internal IDCs were more likely to receive post-susceptibility test combined therapy including carbapenems (77% vs. 26%, p <. 0.001), adequate post-susceptibility test therapies (86% vs. 52%, p <. 0.001), and post-susceptibility therapies prescribed by an infectious diseases specialist (84% vs. 14%, p <. 0.001). Overall, the crude 15-days mortality was 26%. In the final multivariable model, only septic shock at BSI presentation was unfavorably and independently associated with 15-days mortality (odds ratio [OR] 6.7, 95% confidence intervals [CI] 2.6-17.6, p <. 0.001), while a protective effect was observed for post-susceptibility test combined therapies including a carbapenem (OR 0.11, 95% CI 0.03-0.43, p = 0.002).Mortality of CR-Kp remains high. Differences in the incidence of CR-Kp BSI were detected between acute-care centers within the same endemic metropolitan area. Efforts should be made to improve the collaboration and coordination between centers, to prevent further diffusion of CR-Kp

Hypoxia potentiates monocyte-derived dendritic cells for release of tumor necrosis factor alpha via MAP3K8

Dendritic cells (DCs) constantly sample peripheral tissues for antigens, which are subsequently ingested to derive peptides for presentation to T cells in lymph nodes. To do so, DCs have to traverse many different tissues with varying oxygen tensions. Additionally, DCs are often exposed to low oxygen tensions in tumors, where vascularization is lacking, as well as in inflammatory foci, where oxygen is rapidly consumed by inflammatory cells during the respiratory burst. DCs respond to oxygen levels to tailor immune responses to such low-oxygen environments. In the present study, we identified a mechanism of hypoxia-mediated potentiation of release of tumor necrosis factor alpha (TNF-alpha), a pro-inflammatory cytokine with important roles in both anti-cancer immunity and autoimmune disease. We show in human monocyte-derived DCs (moDCs) that this potentiation is controlled exclusively via the p38/mitogen-activated protein kinase (MAPK) pathway. We identified MAPK kinase kinase 8 (MAP3K8) as a target gene of hypoxia-induced factor (HIF), a transcription factor controlled by oxygen tension, upstream of the p38/MAPK pathway. Hypoxia increased expression of MAP3K8 concomitant with the potentiation of TNF-alpha secretion. This potentiation was no longer observed upon siRNA silencing of MAP3K8 or with a small molecule inhibitor of this kinase, and this also decreased p38/MAPK phosphorylation. However, expression of DC maturation markers CD83, CD86, and HLA-DR were not changed by hypoxia. Since DCs play an important role in controlling T-cell activation and differentiation, our results provide novel insight in understanding T-cell responses in inflammation, cancer, autoimmune disease and other diseases where hypoxia is involved

Impaired LAIR-1-mediated immune control due to collagen degradation in fibrosis

Tissue repair is disturbed in fibrotic diseases like systemic sclerosis (SSc), where the deposition of large amounts of extracellular matrix components such as collagen interferes with organ function. LAIR-1 is an inhibitory collagen receptor highly expressed on tissue immune cells. We questioned whether in SSc, impaired LAIR-1-collagen interaction is contributing to the ongoing inflammation and fibrosis. We found that SSc patients do not have an intrinsic defect in LAIR-1 expression or function. Instead, fibroblasts from healthy controls and SSc patients stimulated by soluble factors that drive inflammation and fibrosis in SSc deposit disorganized collagen products in vitro, which are dysfunctional LAIR-1 ligands. This is dependent of matrix metalloproteinases and platelet-derived growth factor receptor signaling. In support of a non-redundant role of LAIR-1 in the control of fibrosis, we found that LAIR-1-deficient mice have increased skin fibrosis in response to repeated injury and in the bleomycin mouse model for SSc. Thus, LAIR-1 represents an essential control mechanism for tissue repair. In fibrotic disease, excessive collagen degradation may lead to a disturbed feedback loop. The presence of functional LAIR-1 in patients provides a therapeutic opportunity to reactivate this intrinsic negative feedback mechanism in fibrotic diseases

Nuclear Receptor Subfamily 4A Signaling as a Key Disease Pathway of CD1c+ Dendritic Cell Dysregulation in Systemic Sclerosis

OBJECTIVE: This study was undertaken to identify key disease pathways driving conventional dendritic cell (cDC) alterations in systemic sclerosis (SSc). METHODS: Transcriptomic profiling was performed on peripheral blood CD1c+ cDCs (cDC2s) isolated from 12 healthy donors and 48 patients with SSc, including all major disease subtypes. We performed differential expression analysis for the different SSc subtypes and healthy donors to uncover genes dysregulated in SSc. To identify biologically relevant pathways, we built a gene coexpression network using weighted gene correlation network analysis. We validated the role of key transcriptional regulators using chromatin immunoprecipitation (ChIP) sequencing and in vitro functional assays. RESULTS: We identified 17 modules of coexpressed genes in cDCs that correlated with SSc subtypes and key clinical traits, including autoantibodies, skin score, and occurrence of interstitial lung disease. A module of immunoregulatory genes was markedly down-regulated in patients with the diffuse SSc subtype characterized by severe fibrosis. Transcriptional regulatory network analysis performed on this module predicted nuclear receptor 4A (NR4A) subfamily genes (NR4A1, NR4A2, NR4A3) as the key transcriptional regulators of inflammation. Indeed, ChIP-sequencing analysis indicated that these NR4A members target numerous differentially expressed genes in SSc cDC2s. Inclusion of NR4A receptor agonists in culture-based experiments provided functional proof that dysregulation of NR4As affects cytokine production by cDC2s and modulates downstream T cell activation. CONCLUSION: NR4A1, NR4A2, and NR4A3 are important regulators of immunosuppressive and fibrosis-associated pathways in SSc cDCs. Thus, the NR4A family represents novel potential targets to restore cDC homeostasis in SSc

The role of hypoxia and metabolism in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is a rare autoimmune disease with heterogeneous symptoms and characterized by immune alteration, vascular abnormalities, fibrosis and hypoxia. SSc is a poorly understood disease with no available effective cure and an unknown pathophysiology. Recent studies identified chemokine (C-X-C-motif) ligand-4 (CXCL4) as a potential biomarker produced by pro-inflammatory immune-cells. Besides, alteration in fat metabolism has been shown to elicit immune-cell polarisation in SSc. The aim of this thesis is to explore the augmented production of CXCL4 and its role in aberrant fibrogenesis in patients with SSc. Moreover, the metabolic status of fat biology in pathophysiology of SSc was further inquired. In healthy immune-cells CXCL4-production depends on mitochondrial reactive oxygen species and hypoxia inducible factor (HIF)-2 stabilization. We observed that Toll-Like receptor (TLR) triggered upon hypoxic environment is responsible for augmented CXCL4-production in SSc. Also, we pinpointed the potential beneficial role of HIF-2 stabilization on cytokine production and confirmed its potential features as a therapeutic target in SSc treatment. Besides, we demonstrated that fatty acids and carnitine composition were altered in SSc and demonstrated that inhibiting fatty acid oxidation abates pro-inflammatory cytokine production in immune-cells of SSc patients. Finally, we observed that inhibition of mammalian target of rapamycin (mTOR), with metformin reduces pro-inflammatory cytokine production, signifying the potential therapeutic effect of metabolic mediators in immune cells. Taken together, targeting TLR stimulation, HIF-2 stabilization and fatty acid oxidation inhibits aberrant cytokine and CXCL4-production in immune cells and metformin treatment can contribute in reducing pro-inflammatory cytokine production in patients with SSc

The role of hypoxia and metabolism in the pathogenesis of systemic sclerosis

Systemic sclerosis (SSc) is a rare autoimmune disease with heterogeneous symptoms and characterized by immune alteration, vascular abnormalities, fibrosis and hypoxia. SSc is a poorly understood disease with no available effective cure and an unknown pathophysiology. Recent studies identified chemokine (C-X-C-motif) ligand-4 (CXCL4) as a potential biomarker produced by pro-inflammatory immune-cells. Besides, alteration in fat metabolism has been shown to elicit immune-cell polarisation in SSc. The aim of this thesis is to explore the augmented production of CXCL4 and its role in aberrant fibrogenesis in patients with SSc. Moreover, the metabolic status of fat biology in pathophysiology of SSc was further inquired. In healthy immune-cells CXCL4-production depends on mitochondrial reactive oxygen species and hypoxia inducible factor (HIF)-2 stabilization. We observed that Toll-Like receptor (TLR) triggered upon hypoxic environment is responsible for augmented CXCL4-production in SSc. Also, we pinpointed the potential beneficial role of HIF-2 stabilization on cytokine production and confirmed its potential features as a therapeutic target in SSc treatment. Besides, we demonstrated that fatty acids and carnitine composition were altered in SSc and demonstrated that inhibiting fatty acid oxidation abates pro-inflammatory cytokine production in immune-cells of SSc patients. Finally, we observed that inhibition of mammalian target of rapamycin (mTOR), with metformin reduces pro-inflammatory cytokine production, signifying the potential therapeutic effect of metabolic mediators in immune cells. Taken together, targeting TLR stimulation, HIF-2 stabilization and fatty acid oxidation inhibits aberrant cytokine and CXCL4-production in immune cells and metformin treatment can contribute in reducing pro-inflammatory cytokine production in patients with SSc

Crossreactive autoantibodies directed against cutaneous and joint antigens are present in psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease of unknown origin, characterized by erosions and new bone formation. Diagnosis of PsA is mainly clinical and there are no biomarkers available. Moreover in PsA autoantibodies have not been described so far. Indeed an autoimmune origin has been suggested but never proven. Aim of the study was to investigate the possible presence of autoantibodies typically associated with PsA.We used pooled IgG immunoglobulins derived from 30 patients with PsA to screen a random peptide library in order to identify disease relevant autoantigen peptides.Among the selected peptides, one was recognised by nearly all the patients' sera. The identified peptide (PsA peptide: TNRRGRGSPGAL) shows sequence similarities with skin autoantigens, such as fibrillin 3, a constituent of actin microfibrils, desmocollin 3, a constituent of the desmosomes and keratin 78, a component of epithelial cytoskeleton. Interestingly the PsA peptide shares homology with the nebulin-related anchoring protein (N-RAP), a protein localized in the enthesis (point of insertion of a tendon or ligament to the bone), which represents the first affected site during early PsA. Antibodies affinity purified against the PsA peptide recognize fibrillin, desmocollin, keratin and N-RAP. Moreover antibodies directed against the PsA peptide are detectable in 85% of PsA patients. Such antibodies are not present in healthy donors and are present in 13/100 patients with seroposive rheumatoid arthritis (RA). In seronegative RA these antibodies are detectable only in 3/100 patients.Our results indicate that PsA is characterized by the presence of serum autoantibodies crossreacting with an epitope shared by skin and joint antigens