Michelly Cristiny Pereira

The Role of PPAR Gamma in Systemic Sclerosis

Fibrosis is recognized as an important feature of many chronic diseases, such as systemic sclerosis (SSc), an autoimmune disease of unknown etiology, characterized by immune dysregulation and vascular injury, followed by progressive fibrosis affecting the skin and multiple internal organs. SSc has a poor prognosis because no therapy has been shown to reverse or arrest the progression of fibrosis, representing a major unmet medical need. Recently, antifibrotic effects of PPARγ ligands have been studied in vitro and in vivo and some theories have emerged leading to new insights. Aberrant PPARγ function seems to be implicated in pathological fibrosis in the skin and lungs. This antifibrotic effect is mainly related to the inhibition of TGF-β/Smad signal transduction but other pathways can be involved. This review focused on recent studies that identified PPARγ as an important novel pathway with critical roles in regulating connective tissue homeostasis, with emphasis on skin and lung fibrosis and its role on systemic sclerosis.

IL-17A, IL-22, IL-6, and IL-21 Serum Levels in Plaque-Type Psoriasis in Brazilian Patients.

Psoriasis is a chronic inflammatory skin disease characterized by alterations in cytokines produced by both Th1 and Th17 pathways. The aim of this study was to evaluate serum levels of pivotal cytokines and correlate them with clinical parameters. Serum samples from 53 psoriasis patients and 35 healthy volunteers, matched by the proportion of sex and age ratios, were collected for ELISA cytokine detection. Psoriasis Area and Severity Index (PASI) was assessed at the time of sampling in psoriasis patients. Our findings demonstrate that IL-17A, IL-22, and IL-6 serum concentrations were significantly higher in psoriasis patients than in the control group. No statistical correlation could be found between cytokines concentrations, PASI score, and age in this study. Although our results do not show any correlation between serum levels of IL-17A, IL-22, and IL-6 and disease activity, the present study confirms that they were increased in Brazilian psoriasis patients in comparison to healthy volunteers.

Synthesis of a Novel Thiazolidinedione and Evaluation of Its Modulatory Effect on IFN-γ, IL-6, IL-17A, and IL-22 Production in PBMCs from Rheumatoid Arthritis Patients

Rheumatoid arthritis (RA) is an autoimmune disease frequently characterized by chronic synovitis of multiple joints. The pathogenesis of RA is complex and involves many proinflammatory cytokines as Th17 related ones. PPARγ is a nuclear receptor activator that represses proinflammatory gene expression. Thus, this work aimed to synthetize a new thiazolidinedione (TZD) analogue based on a well-known anti-inflammatory and PPARγ agonist activity of this ring and evaluate its anti-inflammatory activity. After chemical structure confirmation, the compound named 5-(5-bromo-2-methoxy-benzylidene)-3-(2-nitro-benzyl)-thiazolidine-2,4-dione TM17 was submitted to cytokine releasing inhibition and PPARγ genetic modulation assays. The new compound showed no toxicity on human and murine cells, decreasing IL-6 secretion by murine splenocytes and reducing IL-17A, IL-22, and IFN-γ expression in peripheral blood mononuclear cells from patients with RA. TM17 was more efficient in modulating the mRNA expression of PPARγ than its well-used TZD agonist rosiglitazone. Surprisingly, TM17 was efficient on IL-17A and IFN-γ reduction, like the positive control methylprednisolone, and presented a better effect on IL-22 levels. In conclusion, PBMCs obtained from RA patients under TM17 treatment present a significant reduction in IL-17A, IL-22, and IFN-γ levels, but not IL-6 when compared with nontreated cells, as well as increase PPARγ mRNA expression in absence of stimulus addressing it as a promising molecule in RA treatment.

Interferons and systemic sclerosis: correlation between interferon gamma and interferon-lambda 1 (IL-29)

Abstract Background: Interferon (IFN)-λ1 is a newly described cytokine, member of type III interferons family, which is known for its antiviral, anti-proliferative and antitumor activity. Recent studies indicated that this cytokine has also immune-regulatory function, but its role in the pathogenesis of autoimmune diseases is not established yet. We evaluated serum levels of IFN-λ1 in systemic sclerosis (SSc) patients and healthy controls and its association with IFN-γ and clinical manifestations. Methods: IFN-λ1 and IFN-γ serum levels were measured by ELISA from 52 patients with SSc and 53 healthy controls. Association of cytokines serum levels was sought with clinical parameters. Results: IFN-λ1 and IFN-γ levels in SSc patients were significantly higher than those in healthy individuals (24.82 ± 8.78 and 11.04 ± 3.04 pg/ml, p < 0.0001; 34.11 ± 8.11 and 10.73 ± 2.77 pg/ml, p < 0.0001, respectively). We found a positive correlation between IFN-λ1 and IFN-γ levels in SSc patients (p = 0.0103, r = 0.3526). IFN-γ levels were associated with muscle involvement (p = 0.0483). Conclusion: We first showed raised IFN-λ1 levels in SSc patients. Furthermore, we found a correlation between IFN-λ1 and IFN-γ levels and an association between IFN-γ and myositis. Additional in vitro and in vivo studies are needed to understand IFN-λ1 role in SSc.

Cytokine Profile in Gout: Inflammation Driven by IL-6 and IL-18?

ABSTRACT Introduction: Gout is considered to be an autoinflammatory disease and the presence of monosodium urate (MSU) crystals stimulates activation of NPRL3 inflammasome and subsequently caspase-1, generating production of active IL-1β and IL-18. However, the association between serum cytokines levels and clinical manifestations of the disease is not yet well understood. We evaluated the serum profile of proinflammatory cytokines (IL-1β, IL-6, IL-8, IL-17A, IL-18, IL-22, and IL-23) and described their relationship with clinical and laboratory data. Methodology: Thirty-nine male patients with gout (GG) were assessed for clinical and laboratory variables and cytokine levels were measured by ELISA. For the purposes of comparison, 34 males with no previous history of arthritis were also included in the study (CG). Results: Seventeen participants (43%) exhibited active arthritis on evaluation. Levels of IL-18 were significantly higher in patients in relation to the CG (p = 0.0013). No statistically significant differences were found between the GG and CG for the other measured cytokines. There was a moderate correlation between IL-18 and ESR (R = 0.43, p = 0.0073), CRP (R = 0.47, p = 0.0025), and serum levels of IL-6 (R = 0.36, p = 0.023). An association was observed between serum levels of IL-6 and the presence of tophi (p = 0.005) and deformities (p = 0.0008), as well as a correlation between this cytokine and ESR (R = 0.41, p = 0.011) and CRP (R = 0.48, p = 0.02). Conclusions: IL-18 is associated with inflammatory activity in gout, as well as with IL-6 levels, while IL-6 is associated with clinical and laboratory activity, the presence of tophi and articular deformities, and may be a prognostic marker of this pathology.

Reassessing the Role of the Active TGF-β1 as a Biomarker in Systemic Sclerosis: Association of Serum Levels with Clinical Manifestations.

Objective. To determine active TGF-β1 (aTGF-β1) levels in serum, skin, and peripheral blood mononuclear cell (PBMC) culture supernatants and to understand their associations with clinical parameters in systemic sclerosis (SSc) patients. Methods. We evaluated serum samples from 56 SSc patients and 24 healthy controls (HC). In 20 SSc patients, we quantified spontaneous or anti-CD3/CD28 stimulated production of aTGF-β1 by PBMC. The aTGF-β1 levels were measured by ELISA. Skin biopsies were obtained from 13 SSc patients and six HC, and TGFB1 expression was analyzed by RT-PCR. Results. TGF-β1 serum levels were significantly higher in SSc patients than in HC (p < 0.0001). Patients with increased TGF-β1 serum levels were more likely to have diffuse subset (p = 0.02), digital ulcers (p = 0.02), lung fibrosis (p < 0.0001), positive antitopoisomerase I (p = 0.03), and higher modified Rodnan score (p = 0.046). Most of our culture supernatant samples had undetectable levels of TGF-β1. No significant difference in TGFB1 expression was observed in the SSc skin compared with HC skin. Conclusion. Raised active TGF-β1 serum levels and their association with clinical manifestations in scleroderma patients suggest that this cytokine could be a marker of fibrotic and vascular involvement in SSc.

Corticosteroid inhibits chemokines production in systemic sclerosis patients

HIGHLIGHTSMethylprednisolone inhibited CCL2, CCL5 and CXCL8 production by scleroderma PBMC.No effect was observed on IL‐2, IL‐4, IL‐6, IL‐10, IL‐17A, TFN and IFN‐&ggr; secretion.Methylprednisolone modulates chemokines that mediates pathophysiology of scleroderma. ABSTRACT In this study, we evaluated glucocorticoids (GC) effects on cytokine/chemokine levels in serum samples and peripheral blood mononuclear cell (PBMC) production from systemic sclerosis (SSc) patients. We evaluated cytokine and chemokine levels in serum samples from SSc patients taking or not taking systemic glucocorticoids. PBMCs response to methylprednisolone (MP) was examined from 15 SSc patients and 8 healthy control subjects following PBMC stimulation with anti‐CD3/CD28. Cytokine (IFN‐&ggr;, TNF, IL‐2, IL‐4, IL‐6, IL‐10, and IL‐17A) and chemokine (CXCL8/IL‐8, CCL5/RANTES, CXCL9/MIG, CCL2/MCP‐1, and CXCL10/IP‐10) levels were quantified in serum and in PBMC culture supernatants by CBA or ELISA. Compared with patients not taking corticosteroids, we did not observe any significant differences in cytokines/chemokines serum levels in patients using systemic corticosteroids. After stimulation with anti‐CD3/CD28, PBMCs treated with MP (100 &mgr;M), showed a significant reduction of CCL2/MCP‐1 (p = 0.001), CCL5/RANTES (p = 0.04), and CXCL8/IL‐8 (p = 0.003) levels in SSc patients. In PBMC from healthy controls, we observed decreased IFN‐&ggr;, TNF, IL‐2, and IL‐10 levels after MP treatment, compared with stimulated condition (p < 0.01 for all). However in SSc patients, we did not find any significant reduction in these cytokine levels after MP treatment. In conclusion, CCL2/MCP‐1, CCL5/RANTES, and CXCL8/IL‐8 are chemokines that are potentially modulated by corticosteroids in vitro in SSc patients, but no effect was observed on IL‐2, IL‐4, IL‐6, IL‐10, IL‐17A, TFN, and IFN‐&ggr; secretion. These results suggest a potential effect of GCs on SSc treatment and may reflect the benefit of their use in some patients.

Evaluation of CD4(+)CD25(+)FoxP3(+) T cell populations, IL-10 production, and their correlation with clinical and biochemical parameters in sickle cell anemia patients with leg ulcers.

Leg ulcers (LUs) are a debilitating complication of sickle cell anemia (SCA), with inflammation known to play a crucial role in their pathogenesis. Many studies have described the roles of T helper type 1 (Th1) and Th2 pathways in SCA; however, defects in anti-inflammatory responses are poorly understood. We evaluated interleukin (IL)-10 levels in serum and peripheral blood mononuclear cells (PBMCs) in SCA patients with leg ulcers (SCALU) and without leg ulcers (SCAWH) in addition to CD4(+) CD25(+)FoxP3(+) T cell populations and their its IL-10 expression. In stimulated and unstimulated PBMC cultures, SCALU patients produced higher levels of IL-10 than those in the SCAWH group. Higher levels of IL-10 in SCALU patients correlated with a history of osteonecrosis in stimulated and unstimulated cultures when compared with those in SCAWH. Immunophenotyping revealed that SCALU patients had a higher proportion of CD4(+)CD25(+)FoxP3(+), Tr1 and CD4(+)CD25(+)FoxP3(+)IL-10(+) T cells than other groups. Our findings revealed that IL-10 levels were increased in unstimulated cells from the SCALU group, and that this group also presented with a predominant CD4(+) CD25(+)FoxP3(+) cell population despite many of those cells being IL-10 negative.

Evaluation of Th17 related cytokines associated with clinical and laboratorial parameters in sickle cell anemia patients with leg ulcers.

Leg ulcers (LUs) represent one of the main causes of morbidity in sickle cell anemia (SCA). This manifestation has been related to hemolysis, infections predisposition and inflammation that leads cytokines secretion. In this context, our study aimed to evaluate Th17 related cytokines (IL-6, IL-17A, IL-22 and IL-23) in serum and peripheral mononuclear cells culture supernatants with and without lymphoproliferative stimulation (anti-human CD3 and anti-human CD28). The cytokines levels were also correlated to clinical, hematological and biochemical parameters in SCA patients with and without LUs history (SCALU and SCAWH) as well as in healthy controls. In SCALU patients, high levels of IL-17A were associated with absence of acute chest syndrome (ACS, p=0.0328). The other clinical parameters analyzed (osteonecrosis, stroke, priapism, splenectomy and blood transfusions history) were not significantly related with other cytokine levels. In SCALU patients was also observed that IL-17A increased levels were associated with high levels of LDH (p=0.0130), the same association pattern was found for IL-6 (0.0160) and IL-22 (p=0.0165) in the SCALU group. Interestingly, we did not find statistical correlations with these parameters in SCAWH group. The other hematological parameters (hemoglobin, leucocyte and reticulocyte count) and indirect bilirrubin did not show any correlation with analyzed cytokines in both groups. So, for the first time, we show that IL-17A present in SCALU patients may exert a preventive role in the ACS development. Furthermore, IL-6, IL-17A and IL-22 accompanied the LDH levels only in SCALU patients suggesting to serve as additional markers of hemolysis or to be related with immunity response against extracellular pathogens.

Different profile of cytokine production in patients with systemic sclerosis and association with clinical manifestations

Immune dysregulation is a central process in the pathogenesis of systemic sclerosis (SSc). Cytokines produced by lymphocytes and monocytes are important mediators and induce tissue damage, recruit additional inflammatory cells, and promote extracellular matrix production and fibrosis. In the present research, we aimed to study the associations between levels of cytokines in serum and culture supernatants from peripheral blood mononuclear cells (PBMCs) and clinical manifestations in SSc patients. Serum samples were obtained from 56 SSc patients and 56 unrelated age- and gender-matched healthy individuals. Resting and anti-CD3/CD28-stimulated PBMC cultures were obtained from 19 SSc patients and 8 healthy controls. IL-2, IL-4, IL-6, IL-10, IL-17A, TNF, and IFN-γ levels were measured by ELISA or CBA. Serum cytokines, except IL-17A, were below the kit detection limit in most of the patients and controls. In unstimulated PBMC, the production of TNF(p = 0.004), IL-10(p = .048), IL-2(p < 0.001), and IL-6 (p = 0.01) was higher in SSc patients than in healthy controls. After anti-CD3/CD28 stimulation, scleroderma PBMCs had lower concentrations of TNF(p = 0.009), IL-10(p = .018), and IL-2(p = .002) than HC. In unstimulated PBMC, IL-2 concentration was higher in patients with esophageal dysmotility (p = 0.04), and IL-10 levels had a positive correlation with modified Rodnan score (p = 0.03). After anti-CD3/CD28 stimulation, higher levels of IL-2 and IL-4 were observed in SSc patients with lung fibrosis (p = 0.01 and 0.006, respectively), and higher levels of IL-10 (p = 0.04) and IL-4 (p = 0.04) in patients with digital ulcers. In conclusion, SSc patients have a different profile of cytokine production and this was associated with clinical manifestations.