Summary
Macrophage activation syndrome (MAS) is hyperinflammatory life‐threatening syndrome, associated typically with high levels of serum ferritin. This is an iron storage protein including heavy ...(H) and light (L) subunits, categorized on their molecular weight. The H‐/L subunits ratio may be different in tissues, depending on the specific tissue and pathophysiological status. In this study, we analysed the bone marrow (BM) biopsies of adult MAS patients to assess the presence of: (i) H‐ferritin and L‐ferritin; (ii) CD68+/H‐ferritin+ and CD68+/L‐ferritin+; and (iii) interleukin (IL)‐1β, tumour necrosis factor (TNF) and interferon (IFN)‐γ. We also explored possible correlations of these results with clinical data. H‐ferritin, IL‐1β, TNF and IFN‐γ were increased significantly in MAS. Furthermore, an increased number of CD68+/H‐ferritin+ cells and an infiltrate of cells co‐expressing H‐ferritin and IL‐12, suggesting an infiltrate of M1 macrophages, were observed. H‐ferritin levels and CD68+/H‐ferritin+ cells were correlated with haematological involvement of the disease, serum ferritin and C‐reactive protein. L‐ferritin and CD68+/L‐ferritin+ cells did not correlate with these parameters. In conclusion, during MAS, H‐ferritin, CD68+/H‐ferritin+ cells and proinflammatory cytokines were increased significantly in the BM inflammatory infiltrate, pointing out a possible vicious pathogenic loop. To date, H‐ferritin and CD68+/H‐ferritin+ were associated significantly with haematological involvement of the disease, suggesting biomarkers assessing severity of clinical picture.
Our study suggests the hypothesis that the high levels of tissue H‐ferritin and CD68+/H‐ferritin+ macrophages, observed during MAS, may not only be considered a consequence of the inflammation but possibly involved in a vicious loop perpetuating the inflammatory process.
Summary
Systemic sclerosis (SSc) is an autoimmune disease characterized by significant vascular alterations and multi‐organ fibrosis. Microvascular alterations are the first event of SSc and injured ...endothelial cells (ECs) may transdifferentiate towards myofibroblasts, the cells responsible for fibrosis and collagen deposition. This process is identified as endothelial‐to‐mesenchymal transition (EndMT), and understanding of its development is pivotal to identify early pathogenetic events and new therapeutic targets for SSc. In this review, we have highlighted the molecular mechanisms of EndMT and summarize the evidence of the role played by EndMT during the development of progressive fibrosis in SSc, also exploring the possible therapeutic role of its inhibition.
During Systemic Sclerosis (SSc), the alteration of endothelial cells (ECs) functions plays a pivotal role during vascular remodelling, playing as trigger for fibroproliferative disorder. After pathological stimuli, such as TGF‐β, ET‐1, TNF‐α, IL‐1, INF, hypoxia, ROS and miRs, ECs may trans‐differentiate toward myofibroblasts, through the endothelial‐to‐mesenchymal transition (EndMT), losing vascular ECs markers, gaining mesenchymal cell markers and invading the surrounding tissue. A better understanding of EndMT mechanisms is pivotal, to identify clinically useful biomarkers, in order to develop effective anti‐fibrotic therapies during SSc, a condition in which an appropriated therapy is still lacking.
Summary A better understanding about the mechanisms involved in the pathogenesis of type 2 diabetes mellitus (T2D) showed that inflammatory cytokines such as tumour necrosis factor (TNF) and ...interleukin (IL)-1beta play a pivotal role, mirroring data largely reported in rheumatoid arthritis (RA). IL-1beta is produced mainly by monocytes (MO), and hyperglycaemia may be able to modulate, in the cytoplasm of these cells, the assembly of a nucleotide-binding domain and leucine-rich repeat containing family pyrin (NLRP3)-inflammosome, a cytosolic multi-protein platform where the inactive pro-IL-1beta is cleaved into active form, via caspase-1 activity. In this paper, we evaluated the production of IL-1 beta and TNF, in peripheral blood MO of patients affected by RA or T2D or both diseases, in order to understand if an alteration of the glucose metabolism may influence their proinflammatory status. Our data showed, after 24 h of incubation with different glucose concentrations, a significantly increased production of IL-1beta and TNF in all evaluated groups when compared with healthy controls. However, a significant increase of IL-1beta secretion by T2D/RA was observed when compared with other groups. The analysis of relative mRNA expression confirmed these data. After 24 h of incubation with different concentrations of glucose, our results showed a significant increase in NLRP3 expression. In this work, an increased production of IL-1beta by MO obtained from patients affected by both RA and T2D via NLRP3-inflammasome activation may suggest a potential IL-1beta targeted therapy in these patients.
Summary
A better understanding about the mechanisms involved in the pathogenesis of type 2 diabetes mellitus (T2D) showed that inflammatory cytokines such as tumour necrosis factor (TNF) and ...interleukin (IL)‐1β play a pivotal role, mirroring data largely reported in rheumatoid arthritis (RA). IL‐1β is produced mainly by monocytes (MO), and hyperglycaemia may be able to modulate, in the cytoplasm of these cells, the assembly of a nucleotide‐binding domain and leucine‐rich repeat containing family pyrin (NLRP3)‐inflammosome, a cytosolic multi‐protein platform where the inactive pro‐IL‐1β is cleaved into active form, via caspase‐1 activity. In this paper, we evaluated the production of IL‐1 β and TNF, in peripheral blood MO of patients affected by RA or T2D or both diseases, in order to understand if an alteration of the glucose metabolism may influence their proinflammatory status. Our data showed, after 24 h of incubation with different glucose concentrations, a significantly increased production of IL‐1β and TNF in all evaluated groups when compared with healthy controls. However, a significant increase of IL‐1β secretion by T2D/RA was observed when compared with other groups. The analysis of relative mRNA expression confirmed these data. After 24 h of incubation with different concentrations of glucose, our results showed a significant increase in NLRP3 expression. In this work, an increased production of IL‐1β by MO obtained from patients affected by both RA and T2D via NLRP3‐inflammasome activation may suggest a potential IL‐1β targeted therapy in these patients.
Cytokines such as tumour necrosis factor (TNF)- alpha , interleukin (IL)-12, interferon (IFN)- gamma , IL-23 and, more recently, IL-9, have been implicated in the initiation/maintenance of ...inflammation in psoriasis and psoriatic arthritis (PsA). In the present study we aimed to characterize the role of gamma delta T cells in peripheral blood and synovial fluid of PsA patients and to investigate their response to in-vitro stimulation with antigen or cytokines (IL-9 and IL-23). gamma delta T cells isolated from peripheral blood mononuclear cells and synovial fluid were analysed by flow cytometry to evaluate the phenotype and cytokine production. IL-23R and IL-9R gene expression were also evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Peripheral blood mononuclear cells (PBMC), sorted gamma delta T cells and gamma delta cell lines were also stimulated in vitro with isopentenyl pyrophosphate (IPP), recombinant IL-9 or recombinant IL-23. Our results show an expansion of gamma delta T cells with a predominant effector memory phenotype in peripheral blood and synovium of untreated PsA patients, which reverses significantly after treatment with anti-TNF- alpha or anti-IL-12/IL-23R monoclonal antibodies (mAbs). Moreover, in PsA patients gamma delta T cells activation is driven prevalently by IL-9/IL-9R interaction, and not only by IL-23/IL-23R. Together these findings indicate gamma delta T cells and IL-9 as new players in the pathogenesis of PsA. IL-9/IL-9R axis drives gamma delta T cells activation in psoriatic arthritis patients
Summary
T helper 9 (Th9) cells and interleukin (IL)‐9 are involved in the pathogenesis of several autoimmune diseases. The exact role of IL‐9 and Th9 cells in patients with systemic sclerosis (SSc) ...have not yet been studied adequately. IL‐9, IL‐9R, transcription factor PU.1 (PU.1), IL‐4, thymic stromal lymphopoietin (TSLP) and transforming growth factor (TGF)‐β expression were assessed in skin and kidney biopsies of SSc patients and healthy controls (HC) by immunohistochemistry (IHC). The cellular source of IL‐9 was also analysed by confocal microscopy analysis. Peripheral IL‐9‐producing cells were also studied by flow cytometry. The functional relevance of IL‐9 increased expression in SSc was also investigated. Our results demonstrated a strong expression of IL‐9, IL‐9R, IL‐4, TSLP and TGF‐β in skin tissues of patients with both limited and diffuse SSc. IL‐9 expression was observed mainly in the context of skin infiltrating mononuclear cells and keratinizing squamous epithelium. IL‐9 over‐expression was also observed in renal biopsies of patients with SSc. IL‐9 producing cells in the skin were identified as Th9 cells. Similarly, Th9 cells were expanded and were the major source of IL‐9 among SSc peripheral blood mononuclear cells (PBMC), their percentage being correlated directly with the modified Rodnan skin score. Infiltrating mononuclear cells, mast cells and neutrophils expressed IL‐9R. In in‐vitro studies stimulation with rIL‐9 significantly induced NET (neutrophil extracellular traps) release by dying cells (NETosis) in neutrophils, expansion of mast cells and increase of anti‐systemic scleroderma 70 (Scl70) production by B cells. Our findings suggest that Th9 cells and IL‐9 could be implicated in the pathogenesis of SSc.
IL‐9 and Th9 cells are expanded in the skin, kidney and peripheral blood of SSc patients.
IL‐9 pathway may play an important role in SSc and should be considered as potential therapeutic target in SSc.
Summary
Cytokines such as tumour necrosis factor (TNF)‐α, interleukin (IL)‐12, interferon (IFN)‐γ, IL‐23 and, more recently, IL‐9, have been implicated in the initiation/maintenance of inflammation ...in psoriasis and psoriatic arthritis (PsA). In the present study we aimed to characterize the role of γδ T cells in peripheral blood and synovial fluid of PsA patients and to investigate their response to in‐vitro stimulation with antigen or cytokines (IL‐9 and IL‐23). γδ T cells isolated from peripheral blood mononuclear cells and synovial fluid were analysed by flow cytometry to evaluate the phenotype and cytokine production. IL‐23R and IL‐9R gene expression were also evaluated by reverse transcription–polymerase chain reaction (RT–PCR). Peripheral blood mononuclear cells (PBMC), sorted γδ T cells and γδ cell lines were also stimulated in vitro with isopentenyl pyrophosphate (IPP), recombinant IL‐9 or recombinant IL‐23. Our results show an expansion of γδ T cells with a predominant effector memory phenotype in peripheral blood and synovium of untreated PsA patients, which reverses significantly after treatment with anti‐TNF‐α or anti‐IL‐12/IL‐23R monoclonal antibodies (mAbs). Moreover, in PsA patients γδ T cells activation is driven prevalently by IL‐9/IL‐9R interaction, and not only by IL‐23/IL‐23R. Together these findings indicate γδ T cells and IL‐9 as new players in the pathogenesis of PsA.
IL‐9/IL‐9R axis drives gamma delta T cells activation in psoriatic arthritis patients
Summary
In this work, we aimed to evaluate the levels of ferritin enriched in H subunits (H‐ferritin) and ferritin enriched in L subunits (L‐ferritin) and the cells expressing these two molecules in ...the lymph node (LN) biopsies obtained from adult‐onset Still's disease (AOSD) patients, and the possible correlation among these data and the severity of the disease. Ten patients with AOSD underwent LN biopsy. All the samples were stained by immunofluorescence. A statistical analysis was performed to estimate the possible correlation among both H‐ferritin and L‐ferritin tissue expression and the clinical picture of the disease. Furthermore, the same analysis was performed to evaluate the possible correlation among the number of CD68+/H‐ferritin+ or CD68+/L‐ferritin+ cells and the clinical picture. Immunofluorescence analysis demonstrated an increased tissue H‐ferritin expression in the LNs of AOSD patients. This increased expression correlated with the severity of the disease. An increased number of CD68 macrophages expressing H‐ferritin was observed in the LN samples of our patients. Furthermore, we observed that the number of CD68+/H‐ferritin+ cells correlated significantly with the severity of the clinical picture. Our data showed an imbalance between the levels of H‐ and L‐ferritin in LNs of AOSD patients and the evidence of an increased number of CD68+/H‐ferritin+ cells in the same organs. Furthermore, a correlation among both the tissue H‐ferritin levels and the CD68+/H‐ferritin+ cells and the clinical picture was observed.
Summary
Adult‐onset Still's disease (AOSD) patients may show an evanescent salmon‐pink erythema appearing during febrile attacks and reducing without fever. Some patients may experience this eruption ...for many weeks. During AOSD, exceptionally high serum levels of ferritin may be observed; it is an iron storage protein composed of 24 subunits, heavy (H) subunits and light (L) subunits. The ferritin enriched in L subunits (L‐ferritin) and the ferritin enriched in H subunits (H‐ferritin) may be observed in different tissues. In this work, we aimed to investigate the skin expression of both H‐and L‐ferritin and the number of macrophages expressing these molecules from AOSD patients with persistent cutaneous lesions. We observed an increased expression of H‐ferritin in the skin, associated with an infiltrate in the biopsies obtained from persistent cutaneous lesions of AOSD patients. Furthermore, a positive correlation between H‐ferritin skin levels as well as the number of CD68+/H‐ferritin+ cells and the multi‐visceral involvement of the disease was observed. Our data showed an increased expression of H‐ferritin in the skin of AOSD patients, associated with a strong infiltrate of CD68+/H‐ferritin+ cells. Furthermore, a correlation between the levels of H‐ferritin as well as of the number of CD68+/H‐ferritin+ cells and the multi‐visceral involvement of the disease was observed.
In this work, our data showed an increased expression of H‐ferritin in the skin of AOSD patients associated with the inflammatory cytokines.
We reported an increased presence of macrophages expressing H‐ferritin in the inflammatory infiltrate, mainly M1 macrophages.
A correlation between the levels of H‐ferritin as well as the number of infiltrating CD68+/H‐ferritin+ macrophages and the multi‐visceral involvement of the disease was observed.
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