High-throughput 3D microvessel-on-a-chip model to study defective angiogenesis in systemic sclerosis

In early systemic sclerosis (Scleroderma, SSc), the vasculature is impaired. Although the exact etiology of endothelial cell damage in SSc remains unclear, it is hypothesized that endothelial to mesenchymal transition (EndoMT) plays a key role. To perform physiologically relevant angiogenic studies, we set out to develop an angiogenesis-on-a-chip platform that is suitable for assessing disease parameters that are relevant to SSc and other vasculopathies. In the model, we substituted Fetal Bovine Serum (FBS) with Human Serum without impairing the stability of the culture. We showed that 3D microvessels and angiogenic factor-induced sprouts exposed to key pro-inflammatory and pro-fibrotic cytokines (TNFα and TGFβ) undergo structural alterations consisting of destructive vasculopathy (loss of small vessels). We also showed that these detrimental effects can be prevented by compound-mediated inhibition of TGFβ-ALK5 signaling or addition of a TNFα neutralizing antibody to the 3D cultures. This demonstrates that our in vitro model is suitable for compound testing and identification of new drugs that can protect from microvascular destabilization or regression in disease-mimicking conditions. To support this, we demonstrated that sera obtained from SSc patients can exert an anti-angiogenic effect on the 3D vessel model, opening the doors to screening for potential SSc drugs, enabling direct patient translatability and personalization of drug treatment.

POS0330 NINTEDANIB (TYROSINE KINASE INHIBITOR) DOWNREGULATES THE TRANSITION OF CULTURED SYSTEMIC SCLEROSIS FIBROCYTES INTO MYOFIBROBLASTS AND THEIR PRO-FIBROTIC ACTIVITY

Background:

Fibroblast-to-myofibroblast transition is one of the fundamental steps involved in the fibrotic process that characterise systemic sclerosis (SSc) [1]. Myofibroblasts are α-smooth muscle actin (αSMA) positive cells that contribute to fibrosis through the excessive synthesis and deposition of extracellular matrix (ECM) proteins, primarily fibronectin (FN) and type I collagen (COL1) [2].

Among the cells involved in the fibrotic process of SSc, circulating fibrocytes seem to have an emerging role as an important source of fibroblasts and myofibroblasts [3].

Nintedanib is a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis that interferes with the signalling pathways involved in the pathogenesis of fibrosis (4). Nintedanib was recently demonstrated to have a beneficial effect in patients with interstitial lung disease (ILD) associated with SSc (5).

Objectives:

To investigate nintedanib effect in inhibiting the in vitro transition of circulating SSc fibrocytes into myofibroblasts and their pro-fibrotic activity.

Methods:

Circulating fibrocytes were obtained from 14 SSc patients (mean age 64±14 years), who fulfilled the 2013 ACR/EULAR criteria for SSc and that underwent complete disease staging in a day-hospital setting at the Rheumatology Division of Genoa University. Five age-matched healthy subjects (HSs) were also analysed. All SSc patients and HSs signed the informed consent and the local EC approved the study. Peripheral blood mononuclear cells were isolated by density gradient centrifugation and plated on FN-coated dishes. After overnight culture, non-adherent cells were removed, and adherent cells were maintained in growth medium for 8 days (T8) to obtain fibrocytes [6]. T8-cultured SSc fibrocytes were maintained in growth medium (untreated cells) or treated with nintedanib 0.1μM and 1μM for 3 and 24 hours. Fibroblast specific protein-1 (S100A4) and αSMA, as markers of fibroblast/myofibroblast phenotype, together with COL1 and FN, were investigated by qRT-PCR and Western blotting. Non-parametric Mann-Whitney and Wilcoxon tests were used for the statistical analysis.

Results:

Significantly elevated gene and protein expressions of αSMA, S100A4, COL1 and FN were observed in SSc fibrocytes compared to HS fibrocytes (gene: αSMA p<0.001; others p<0.0001; protein: all p<0.05). In accordance with the antibody positivity for Scl70 and the presence or absence of ILD at CT scan, SSc patients were grouped as either Scl70 positive patients with ILD (Scl70+ILD+) or Scl70 negative patients without ILD (Scl70-ILD-). Significant αSMA, S100A4, COL1 and FN gene expressions were found in fibrocytes from Scl70+ILD+ compared to HS fibrocytes (αSMA p<0.001; others p<0.0001). Moreover, fibrocytes from Scl70+ILD+patients showed a more significant gene expression of fibroblasts/myofibroblasts markers compared to Scl70-ILD-patients (p<0.01 for S100A4), whereas no differences were observed for ECM gene expression.

Nintedanib reduced the gene and protein expression of αSMA, COL1 and FN in SSc fibrocytes compared to untreated ones with different statistical significance.

Noteworthy, nintedanib significantly downregulated αSMA, S100A4, COL1 and FN gene expression (all p<0.05) in Scl70+ILD+fibrocytes, whereas only that of S100A4 and FN was significantly downregulated (p<0.05) in Scl70-ILD- fibrocytes compared to untreated cells.

Conclusion:

Nintedanib seems to downregulate in vitro the transition of fibrocytes into myofibroblasts and their pro-fibrotic activity, particularly in cells isolated from Scl70+ILD+SSc patients.

References:

[1]Cutolo M et al. Exp Rev Clin Immunol. 2019;15:753-64.

[2]Van Caam A et al. Front. Immunol. 2018;9:2452.doi:10.3389/fimmu.2018.02452.

[3]Distler JH et al. Arthritis Rheumatol. 2017;69:257-67.

[4]Distler O et al. New Eng J Med. 2019; 380:2518-28.

[5]Maher TB et al. Arthritis Rheumatol.2020.doi:10.1002/art.41576.

[6]Cutolo M et al. Arthritis Res Ther. 2018;20:157.doi:10.1186/s13075-018-1652-6.

Acknowledgements:

We thank Stefano-Lutz Willing for the scientific support through the study.

Disclosure of Interests:

Stefano Soldano: None declared, Paola Montagna: None declared, Emanuele Gotelli: None declared, Samuele Tardito: None declared, Sabrina Paolino: None declared, Claudio Corallo: None declared, Carmen Pizzorni: None declared, Alberto Sulli: None declared, Carlotta Schenone: None declared, Greta Pacini: None declared, Vanessa Smith: None declared, Maurizio Cutolo Grant/research support from: I received grant/research support from Bristol-Myers Squibb, Boehringer, Celgene

Apremilast interferes with the TGFβ1-induced transition of human skin fibroblasts into profibrotic myofibroblasts: in vitro study

OBJECTIVES

Fibroblast-to-myofibroblast transition and extracellular matrix overproduction represent progressive events in chronic inflammatory and fibrotic diseases, in which TGFβ1 is one of the key mediators. Phosphodiesterase 4 (PDE4) acts as a proinflammatory enzyme through the degradation of cyclic adenosine monophosphate and it is overexpressed in skin fibroblasts. The study investigated how apremilast (a PDE4 inhibitor) interferes with the intracellular signalling pathways responsible for the TGFβ1-induced fibroblast-to-myofibroblast transition and profibrotic extracellular matrix protein synthesis.

METHODS

Cultured human skin fibroblasts were stimulated with TGFβ1 (10 ng/ml) alone or combined with apremilast (1 and 10 μM) for 4, 16 and 24 h. Other aliquots of the same cells were previously stimulated with TGFβ1 and then treated with apremilast (1 and 10 μM) for 4, 16 and 24 h, always under stimulation with TGFβ1. Gene and protein expression of αSMA, type I collagen (COL1) and fibronectin were evaluated, together with the activation of small mothers against decapentaplegic 2 and 3 (Smad2/3) and extracellular signal-regulated kinase (Erk1/2) proteins.

RESULTS

Apremilast reduced the TGFβ1-induced increase in αSMA, COL1 and fibronectin gene expression at 4 and 16 h, and protein synthesis at 24 h of treatment in cultured fibroblasts, even for cells already differentiated into myofibroblasts by way of a previous stimulation with TGFβ1. Apremilast inhibited the TGFβ1-induced Smad2/3 and Erk1/2 phosphorylation at 15 and 30 min.

CONCLUSION

Apremilast seems to inhibit in vitro the fibroblast-to-myofibroblast transition and the profibrotic activity induced by TGFβ1 in cultured human skin fibroblasts by downregulating Smad2/3 and Erk1/2 intracellular signalling pathways.

SAT0293 EXOSOMES DERIVED FROM PLASMA OF SYSTEMIC SCLEROSIS (SSC) PATIENTS AND FROM SSC CULTURED FIBROBLASTS CONTAIN PRO-FIBROTIC MIRNA SIGNATURES AND COULD INDUCE MYOFIBROBLAST DIFFERENTIATION IN VITRO

Background:

Exosomes generated great resonance in the last few years due to their important roles in different biological pathways and diseases, including systemic sclerosis (SSc) (1). They are lipid-like nanovesicles containing biomarkers, such as proteins, lipids, macromolecules and nucleic acids, including microRNA (miRNA) (2). Exosomes are implicated in intercellular communication by fusing and releasing their cargo into the target cells (3).

Objectives:

In the present study, we evaluated the potential of exosomes deriving from plasma of SSc patients or generating from cultured SSc fibroblasts to drive the fibrotic signaling in the disease.

Methods:

Exosomes were isolated from plasma of n=10 SSc patients and from n=10 control subjects. Exosomes were also purified from cell culture supernatants of SSc fibroblasts and of control fibroblasts. Exosome size and concentration were assessed by Nanosight Particle Tracking Analysis (NTA) and by transmission electron microscopy (TEM). The content of anti-fibrotic (let-7a, 146a, 200a, 223a) and pro-fibrotic (150, 155) miRNAs was assessed in all the plasma-derived and cell culture-derived exosome populations by semiquantitative real time PCR. Finally, isolated exosomes were used to stimulate control dermal fibroblasts in culture. Gene expressions (COL1A1, ACTA2 and TAGLN) were assessed by quantitative real time PCR (qRT-PCR) and protein levels (type-I-collagen, α-SMA and SM22) by immunofluorescence (IF).

Results:

Exosomes isolated from SSc plasma samples showed higher concentration (3.3x1010±1.1x1010particles/mL) compared to those isolated from control plasma ones (1.5x1010±0.4x1010particles/mL) (p<0.01). The exosome size did not differ between SSc and control plasma samples and ranged from 50nm to 150nm. Similar results were obtained with exosomes generated from fibroblast cultures: the concentration was higher in SSc fibroblasts (1.1x1010±0.2x1010particles/mL) than in control ones (0.4x1010±0.1x1010particles/mL) (p<0.05) with no significant differences in size distribution. The content of all anti-fibrotic (let-7a, 146a, 200a, 223a) miRNAs was decreased in exosomes coming from both SSc plasma samples and from SSc fibroblasts with respect to control plasma samples (p<0.05) and to control fibroblasts (p<0.05). On the contrary, the pro-fibrotic (150, 155) miRNAs were significantly upregulated in exosomes deriving from SSc plasma samples and from SSc fibroblasts, with respect to control plasma samples (p<0.05) and to control fibroblasts (p<0.05). Finally, only exosomes coming from SSc plasma samples or SSc fibroblast cultures were able to induce pro-fibrotic gene (COL1A1, ACTA2 and TAGLN) and protein (type-I-collagen, α-SMA and SM22) expression in control fibroblasts. No pro-fibrotic induction was seen in presence of exosomes isolated from control plasma samples or control fibroblast cultures.

Conclusion:

This study demonstrates that plasma from SSc patients contains higher concentration of exosomes compared to plasma from control subjects and SSc-derived exosomes contain specific pro-fibrotic miRNA signatures that can induce myofibroblast differentiationin vitro. These results suggest that exosomes could be fibrotic drivers towards non-affected areasin vivo, and they might represent novel targets for precision medicine treatments in SSc.

References:

[1]Zhu T, Wang Y, Jin H, Li L. The role of exosome in autoimmune connective tissue disease. Ann Med. 2019 Mar;51(2):101-108.

[2]Wermuth PJ, Piera-Velazquez S, Rosenbloom J, et al. Existing and novel biomarkers for precision medicine in systemic sclerosis. Nat Rev Rheumatol. 2018 Jul;14(7):421-432.

[3]Colletti M, Galardi A, De Santis M, et al. Exosomes in Systemic Sclerosis: Messengers Between Immune, Vascular and Fibrotic Components? Int J Mol Sci. 2019 Sep 4;20(18). pii: E4337.

Disclosure of Interests:

Claudio Corallo: None declared, Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Actelion, Celgene, Consultant of: Bristol-Myers Squibb, Speakers bureau: Sigma-Alpha, Stefano Soldano: None declared, Enrico Selvi: None declared, Francesca Bellisai: None declared, Nicola Giordano: None declared

SAT0300 SERUM FROM “EARLY” SYSTEMIC SCLEROSIS PATIENTS ALREADY INDUCES THE ALTERNATIVELY ACTIVATED MACROPHAGE PHENOTYPE (M2) IN CULTURED HUMAN MONOCYTES

Background:

Alternatively activated (M2) macrophages seem to play a role in the fibrotic process of systemic sclerosis (SSc) as potential inducers of tissue fibrosis through their secretion of specific cytokines and chemokines, such as interleukin-10 (IL-10), macrophage derived chemokine (CCL-22) and pro-fibrotic metalloproteases (i.e. MMP9) (1-3).

Objectives:

To investigate the presence of circulating cells belonging to the monocyte lineage showing an M2 phenotype in SSc patients (pts) and possible correlation with the clinical parameters of the disease. Moreover, to investigate if the treatment of cultured monocytes isolated from healthy subjects with serum derived from early SSc pts may induce theirin vitropolarization into M2 macrophages.

Methods:

Fifty female SSc pts (mean age 64±13 yrs), fulfilling the EULAR/ACR criteria, and 27 gender-matched healthy subjects (HSs, mean age 57±7 yrs) were considered at the Rheumatology Division of Genoa University after written informed consent. Nailfold videocapillaroscopy (NVC), serum SSc-related antibodies and skin involvement were investigated. Circulating cells belonging to the monocyte populations (CD45+and CD14+cells) were characterised by flow cytometry using specific surface markers of M2 phenotypes (CD204, CD206, CD163). Each SSc pt had been under stable treatment regimen for at least six months. Cultured monocytes, isolated by negative selection from peripheral blood mononuclear cells (PBMCs) of 8 HSs, stimulated for 48 hrs with 10% of serum of lcSSc pts with “Early” NVC pattern, as well as serum of dcSSc pts with “Active” and “Late” NVC patterns. Cultured monocyte human cell line (THP1) was differentiated into macrophages (5ng/ml of phorbol myristate acetate) and then stimulated with SSc sera. The expression of CD204, CD206 (M2 markers) and CD68 was investigated by immunocytochemistry, whereas MMP9 secretion was investigated by zymography. Statistical analysis was performed using Mann-Whitney and Kruskal-Wallis tests, and correlations were explored by bivariate Pearson’s analysis.

Results:

In SSc pts the percentage of circulating M2 cells (CD14+CD204+CD163+CD206+cells) was significantly increased compared to both HSs and SSc pts not under immunosuppressive treatment (p<0.05) However, no correlation with skin involvement and SSc-related antibodies was observed. Cultured macrophages stimulated with SSc serum expressed CD204 and CD206 markers compared to the macrophages stimulated with HS serum (CD204 and CD206 double negative cells). Of note, the ability to express M2 markers was already evident in cultured macrophages stimulated with “Early” NVC SSc serum and their expression even increased in macrophages stimulated with “Active” and “Late” NVC sera together with the secretion of MMP9. Same results were observed also in cultured THP1-derived macrophages.

Conclusion:

The study confirmed that SSc pts are characterized by a significant increase of circulating M2 cells, suggesting their possible involvement in the pathogenesis of the disease. Interestingly, results insinuate that sera from SSc patients already in an “Early” NVC condition (sera known to contains specific profibrotic molecules such as cytokines, growth factors like TGFb1 or endothelin-1) seem able to inducein vitroa profibrotic M2 macrophage phenotype.

References:

[1]Cutolo M et al. ExpRevClin Immunol. 2019;15:753-64.

[2]Stifano G et al. Curr Rheumatol Rep. 2016; 18:2. doi: 10.1007/s11926-015-0554-8.

[3]Medeiros NI et al. Parasite Immunol. 2017;39: doi: 10.1111/pim.12446.

Disclosure of Interests:

Stefano Soldano: None declared, Samuele Tardito: None declared, Sabrina Paolino: None declared, Massimo Patanè: None declared, Emanuele Gotelli: None declared, Claudio Corallo: None declared, Carmen Pizzorni: None declared, Greta Pacini: None declared, Federica Goegan: None declared, Alberto Sulli Grant/research support from: Laboratori Baldacci, Carlotta Schenone: None declared, Vanessa Smith Grant/research support from: The affiliated company received grants from Research Foundation - Flanders (FWO), Belgian Fund for Scientific Research in Rheumatic diseases (FWRO), Boehringer Ingelheim Pharma GmbH & Co and Janssen-Cilag NV, Consultant of: Boehringer-Ingelheim Pharma GmbH & Co, Speakers bureau: Actelion Pharmaceuticals Ltd, Boehringer-Ingelheim Pharma GmbH & Co and UCB Biopharma Sprl, Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Actelion, Celgene, Consultant of: Bristol-Myers Squibb, Speakers bureau: Sigma-Alpha

AB0168 NINTEDANIB (TYROSINE-KINASE INHIBITOR) INHIBITS THE TRANSITION OF CIRCULATING FIBROCYTES ISOLATED FROM SYSTEMIC SCLEROSIS PATIENTS INTO MYOFIBROBLASTS: AN IN VITROSTUDY

Background:

Systemic sclerosis (SSc) is a chronic connective disease characterized by microvascular alterations, dysregulated immune response and fibrosis [1,2]. Myofibroblasts are alpha-smooth muscle actin (alphaSMA)+cells and play a crucial role in fibrosis, through the excessive synthesis and deposition of extracellular matrix (ECM) proteins, in particular fibronectin (FN) and type I collagen (COL1) [3]. Despite myofibroblasts primarily derive from resident fibroblasts transition and differentiation, another important source is represented by circulating fibrocytes [4]. Nintedanib is a tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis that interferes with the signalling pathways involved in the pathogenesis of fibrosis [5].

Objectives:

To investigate the possible effects of nintedanib in contrasting the ability of cultured mature fibrocytes from SSc patients to differentiate into profibrotic myofibroblasts.

Methods:

Circulating fibrocytes were obtained from peripheral blood mononuclear cells isolated from 5 limited cutaneous SSc patients (mean age 68 +/- 10 years) and then plated on FN-coated tissue culture dishes in growth medium (DMEM at 20% of fetal bovine serum, 1% of penicillin-streptomycin and 1% L-glutamine), to allow the adhesion of fibrocyte precursors. Adherent cells were maintained in growth medium for 8 days in order to allow their differentiation into fibrocytes. Differentiated fibrocytes were treated with nintedanib at the concentrations of 100nM and 1000nM for 3 and 24 hours (hrs) or maintained in growth medium without any treatment. The differentiation of fibrocytes into myofibroblasts was determined evaluating the gene expression of alphaSMA, fibroblast specific protein-1 (S100A4) COL1, FN and CXCR4 by quantitative real-time polymerase chain reaction, and the protein synthesis of alphaSMA, COL1 and FN by western blotting.

Results:

Nintedanib inhibited alphaSMA and S100A4 gene expression already at the concentration of 100nM in cultured fibrocytes and after 3 hrs of treatment, when compared with untreated cells. Furthermore, both concentrations of nintedanib (100nM and 1000nM) reduced the gene expression of COL1 and FN, whereas only 100nM downregulated the CXCR4 gene expression. At protein level, nintedanib 100nM and 1000nM reduced the synthesis of alphaSMA and COL1 after 24 hrs of treatment, whereas FN synthesis was reduced only by the nintedanib concentration of 1000nM.

Conclusion:

The preliminary results show that nintedanib may inhibit thein vitrotransition of SSc fibrocytes into myofibroblasts and their profibrotic activity, through the reduction of specific myofibroblast phenotype markers and ECM protein production. The results seem to suggest fibrocytes as further possible target of the antifibrotic action of nintedanib in SSc.

References:

[1]Cutolo M et al. Expert Rev Clin Immunol. 2019;15:753-64 2. Barsotti S et al. Clin Exp Rheumatol. 2016;34(Suppl.100):S3-S13 3. Wynn TA et al. Nat Med. 2012;18:1028-40. 4.Distler JHW et al. Arthritis Rheumatol. 2017;69:257-67 5.Hilberg F et al. Cancer Res. 2008;68:4774-82.

Disclosure of Interests:

Stefano Soldano: None declared, Giulia Martinelli: None declared, Samuele Tardito: None declared, Sabrina Paolino: None declared, Massimo Patanè: None declared, Emanuele Gotelli: None declared, Claudio Corallo: None declared, Carmen Pizzorni: None declared, Alberto Sulli Grant/research support from: Laboratori Baldacci, Carlotta Schenone: None declared, Vanessa Smith Grant/research support from: The affiliated company received grants from Research Foundation - Flanders (FWO), Belgian Fund for Scientific Research in Rheumatic diseases (FWRO), Boehringer Ingelheim Pharma GmbH & Co and Janssen-Cilag NV, Consultant of: Boehringer-Ingelheim Pharma GmbH & Co, Speakers bureau: Actelion Pharmaceuticals Ltd, Boehringer-Ingelheim Pharma GmbH & Co and UCB Biopharma Sprl, Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Actelion, Celgene, Consultant of: Bristol-Myers Squibb, Speakers bureau: Sigma-Alpha

Sarcopenia in systemic sclerosis: the impact of nutritional, clinical, and laboratory features

We evaluated the presence of sarcopenia in a population of systemic sclerosis (SSc) patients, with respect to nutritional, clinical, and laboratory features. A total of 62 patients who met the ACR/EULAR 2013 classification criteria were enrolled. Sarcopenia was defined according to the Relative Skeletal Mass Index (RSMI) and hand grip strength (HGS). Body composition was assessed with the calculation of the Body Mass Index (BMI), lean body mass (LBM) and fat mass (FM). Malnutrition was evaluated according to the ESPEN criteria. Clinical evaluation included nailfold capillaroscopy and skin evaluation by modified Rodnan Skin Score (mRSS), pulmonary function tests (PFT) with diffusing capacity for carbon monoxide adjusted for hemoglobin (DLCO), high-resolution computed tomography (HR-CT) of the lungs, echocardiography and high-resolution manometry (HRM) for esophageal involvement. Laboratory evaluation included erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), hemoglobin, creatinine, creatine kinase (CK), transaminases, lipid profile, glycemia, albumin, and vitamin-D. Antinuclear antibodies (ANA) and extractable nuclear antigens (ENA) were also assessed. Considering RSMI, the prevalence of sarcopenia is 42%. In this case, age, malnutrition, disease duration, mRSS, capillaroscopy score, esophageal involvement, ESR, and ANA titer are higher in the sarcopenic group, while DLCO and LBM are lower. Considering HGS, the prevalence of sarcopenia is 55%. Age, disease duration, malnutrition, FM, mRSS, capillaroscopy score, esophageal involvement, ESR, and ENA positivity are higher in the sarcopenic group, while DLCO is lower. By using both RSMI and HGS to assess sarcopenia in SSc, the results of this study demonstrated that this condition correlates with different nutritional, clinical, and biochemical parameters associated with the worsening of the disease.

Altered expression of RXFP1 receptor contributes to the inefficacy of relaxin-based anti-fibrotic treatments in systemic sclerosis

OBJECTIVES

Relaxin is a potent anti-fibrotic hormone that has been tested to ameliorate fibrosis in systemic sclerosis (SSc), but with controversial results. The aim of the study is to sequence relaxin receptor gene RXFP1 and to assess its mRNA expression and protein levels in the skin of SSc patients and healthy subjects.

METHODS

Fibroblasts were isolated from unaffected/affected skin samples of (n=16) limited-cutaneous-SSc-(LcSSc) and from affected ones of (n=4) diffuse-cutaneous-SSc-(DcSSc) patients. Fibroblasts from healthy subjects were used as controls. Sequencing of exonic target regions of interest for RXFP1 gene was performed, coupled with mRNA transcript variant analysis. RXFP1 mRNA and protein levels were assessed by quantitative-real-time-PCR-(qRT-PCR) and by immunocytochemistry-(ICC). Alpha-smooth-muscle-actin-(α-SMA) synthesis induced by transforming-growth-factor-beta-1-(TGF-β1) stimulation was investigated in all fibroblasts with and without pre-treatment with serelaxin (a recombinant form of human relaxin-2 targeting the receptor RXFP1).

RESULTS

Sequencing of RXFP1 gene showed no relevant mutations in all fibroblast populations. The analysis of mRNA transcripts revealed the presence of 13 different mRNA isoforms of RXFP1 (7 coding and 6 non-coding) upregulated in LcSSc/DcSSc-affected samples and not in LcSSc-unaffected and in healthy ones. On the contrary, ICC demonstrated the absence of RXFP1 in LcSSc/DcSSc-affected fibroblasts and the presence in LcSSc-unaffected and in healthy ones. To prove these findings, serelaxin pre-incubation was unable to counteract TGF-β1-driven upregulation of α-SMA in LcSSc/DcSSc-affected fibroblasts only, but not in LcSSc-unaffected and healthy ones.

CONCLUSIONS

The absence/altered expression of relaxin receptor RXFP1 in the affected fibroblasts of SSc patients could explain the inefficacy of relaxin-based anti-fibrotic treatments in the disease.

Antibodies against specific extractable nuclear antigens (ENAs) as diagnostic and prognostic tools and inducers of a profibrotic phenotype in cultured human skin fibroblasts: are they functional?

BACKGROUND

The importance of systemic sclerosis (SSc) autoantibodies for diagnosis has become recognized by their incorporation into the 2013 ACR/EULAR classification criteria. Clear prognostic and phenotypic associations with cutaneous subtype and internal organ involvement have been also described. However, little is known about the potential of autoantibodies to exert a direct pathogenic role in SSc. The aim of the study is to assess the pathogenic capacity of anti-DNA-topoisomerase I (anti-Topo-I) and anti-centromeric protein B (anti-Cenp-B) autoantibodies to induce pro-fibrotic markers in dermal fibroblasts.

METHODS

Dermal fibroblasts were isolated from unaffected and affected skin samples of (n = 10) limited cutaneous SSc (LcSSc) patients, from affected skin samples of diffuse cutaneous (DcSSc) patients (n = 10) and from healthy subjects (n = 20). Fibroblasts were stimulated with anti-Topo-I, anti-Cenp-B IgGs, and control IgGs in ratios 1:100 and 1:200 for 24 h. Cells were also incubated with 10% SSc anti-Topo-I⁺ and anti-Cenp-B⁺ whole serum and with 10% control serum for 24 h. Viability was assessed by MTT test, while apoptosis was assessed by flow cytometry. Activation of pro-fibrotic genes ACTA2, COL1A1, and TAGLN was evaluated by quantitative real-time PCR (qPCR), while the respective protein levels alpha-smooth-muscle actin (α-SMA), type-I-collagen (Col-I), and transgelin (SM22) were assessed by immunocytochemistry (ICC).

RESULTS

MTT showed that anti-Cenp-B/anti-Topo-I IgGs and anti-Cenp-B⁺/anti-Topo-I⁺ sera reduced viability (in a dilution-dependent manner for IgGs) for all the fibroblast populations. Apoptosis is induced in unaffected LcSSc and control fibroblasts, while affected LcSSc/DcSSc fibroblasts showed apoptosis resistance. Basal mRNA (ACTA2, COL1A1, and TAGLN) and protein (α-SMA, Col-1, and SM22) levels were higher in affected LcSSc/DcSSc fibroblasts compared to LcSSc unaffected and to control ones. Stimulation with anti-Cenp-B/anti-Topo-I IgGs and with anti-Cenp-B⁺/anti-Topo-I⁺ sera showed a better induction in unaffected LcSSc and control fibroblasts. However, a statistically significant increase of all pro-fibrotic markers is reported also in affected LcSSc/DcSSc fibroblasts upon stimulation with both IgGs and sera.

CONCLUSIONS

This study suggests a pathogenic role of SSc-specific autoantibodies to directly induce pro-fibrotic activation in human dermal fibroblasts. Therefore, besides the diagnostic and prognostic use of those autoantibodies, these data might further justify the importance of immunosuppressive drugs in the early stages of the autoimmune disease, including SSc.

Pulmonary arterial hypertension in systemic sclerosis: Diagnosis and treatment according to the European Society of Cardiology and European Respiratory Society 2015 guidelines

Scleroderma (systemic sclerosis) is an autoimmune connective tissue disease which presents endothelial dysfunction and fibroblast dysregulation, resulting in vascular and fibrotic disorders. Pulmonary hypertension is frequent in patients with systemic sclerosis: the natural evolution of the disease can induce the development of different forms of pulmonary hypertension, representing one of the main causes of death. Among the different forms of pulmonary hypertension in systemic sclerosis, pulmonary arterial hypertension is the most frequent one (rate of occurrence is estimated between 7% and 12%). This pulmonary vascular complication should be treated with a combination of drugs that is able to counteract endothelial dysfunction, antagonizing the endothelin-1 system and replacing prostaglandin I2 and nitric oxide activity. A correct diagnosis is mandatory, because it is possible only for pulmonary arterial hypertension to use specific drugs that are able to control the symptomatic condition and the evolution of the disease. According to the most recent guidelines, for the patients with systemic sclerosis, also without pulmonary hypertension symptoms, echocardiography screening for the detection of pulmonary hypertension is recommended. Pulmonary arterial hypertension screening programs in systemic sclerosis patients is able to identify milder forms of the disease, allowing earlier management and better long-term outcome.

Methylsulfonylmethane and mobilee prevent negative effect of IL-1β in human chondrocyte cultures via NF-κB signaling pathway

Nutraceuticals are compounds that serve as nutrition with an easy accessibility and favourable safety profile. Recent studies showed their potential activity on osteoarthritis (OA) inflammation and cartilage metabolism. We investigated the effect of methylsulfonylmethane (MSM) and mobilee in human OA chondrocyte cultures exposed to interleukin (IL)-1β. OA cartilage was obtained from femoral heads of five patients undergoing total replacement surgery. Chondrocytes were incubated with mobilee (200 and 500 μM) and MSM (2000 and 6000 μM) in presence of IL-1β (10 ng/mL) and nuclear factor (NF)-κB inhibitor (BAY 11-7082, 1 μM), for 24 and 48 h. Viability and apoptosis were performed by MMT and flow cytometry. The metalloproteinase (MMP)-1,-3,-13 and type II collagen (Col2a1) were analyzed by qRT-PCR and ELISA, and NF-κB activation by immunofluorescence. IL-1β stimulus determined a significant regulation of survival, apoptotic ratio, as well as of gene expression and serum levels of MMP-1,-3,-13 and Col2a1 in OA chondrocytes compared to baseline. Mobilee and MSM incubation significantly reversed the effect of IL-1β. IL-1β significantly induced NF-κB p50 nuclear translocation, which was significantly counteracted by the pre-treatment of OA chodrocytes with the tested compounds. BAY11-7082 significantly modulated MMPs and Col2a1 expression respectively to basal state. Co-treatment of IL-1β with mobilee, MSM and BAY11-7082 didn't cause changes of MMPs or Col2a1 beyond that caused by each single treatment. We demonstrated that MSM and mobilee have a beneficial effect on OA chondrocytes metabolism, probably due to the modulation of NF-κB pathway, providing a powerful rationale for the use of these substances in OA treatment.

Effects of selexipag and its active metabolite in contrasting the profibrotic myofibroblast activity in cultured scleroderma skin fibroblasts

Background

Myofibroblasts contribute to fibrosis through the overproduction of extracellular matrix (ECM) proteins, primarily type I collagen (COL-1) and fibronectin (FN), a process which is mediated in systemic sclerosis (SSc) by the activation of fibrogenic intracellular signaling transduction molecules, including extracellular signal-regulated kinases 1 and 2 (Erk1/2) and protein kinase B (Akt). Selexipag is a prostacyclin receptor agonist synthesized for the treatment of pulmonary arterial hypertension. The study investigated the possibility for selexipag and its active metabolite (ACT-333679) to downregulate the profibrotic activity in primary cultures of SSc fibroblasts/myofibroblasts and the fibrogenic signaling molecules involved.

Methods

Fibroblasts from skin biopsies obtained with Ethics Committee (EC) approval from patients with SSc, after giving signed informed consent, were cultured until the 3^rd culture passage and then either maintained in normal growth medium (untreated cells) or independently treated with different concentrations of selexipag (from 30 μM to 0.3 μM) or ACT-333679 (from 10 μM to 0.1 μM) for 48 h. Protein and gene expressions of α-smooth muscle actin (α-SMA), fibroblast specific protein-1 (S100A4), COL-1, and FN were investigated by western blotting and quantitative real-time PCR. Erk1/2 and Akt phosphorylation was investigated in untreated and ACT-333679-treated cells by western botting.

Results

Selexipag and ACT-333679 significantly reduced protein synthesis and gene expression of α-SMA, S100A4, and COL-1 in cultured SSc fibroblasts/myofibroblasts compared to untreated cells, whereas FN was significantly downregulated at the protein level. Interestingly, ACT-333679 significantly reduced the phosphorylation of Erk1/2 and Akt in cultured SSc fibroblasts/myofibroblasts.

Conclusions

Selexipag and mainly its active metabolite ACT-333679 were found for the first time to potentially interfere with the profibrotic activity of cultured SSc fibroblasts/myofibroblasts at least in vitro, possibly through the downregulation of fibrogenic Erk1/2 and Akt signaling molecules.

Activation of the Wnt Pathway by Small Peptides: Rational Design, Synthesis and Biological Evaluation

A computational analysis of the X-ray structure of the low-density lipoprotein receptor-related protein 6 (LRP6) with the Dickkopf-1 (DKK1) C-terminal fragment has allowed us to rationally design a small set of decapeptides. These compounds behave as agonists of the canonical Wnt pathway in the micromolar range when tested on a dual luciferase Wnt functional assay in glioblastoma cells. Two of the oligopeptides showed a lack of cytotoxicity in human primary osteoblasts isolated from sponge bone tissue (femoral heads or knees of elderly patients). According to the mechanism of action, the studies revealed a dose- and time-dependent increase in the viability of human osteoblasts. These results may indicate a potential therapeutic application of this class of compounds in the treatment of bone diseases related to aging, such as osteoporosis.

Dual endothelin receptor antagonists contrast the effects induced by endothelin-1 on cultured human microvascular endothelial cells

OBJECTIVES

To evaluate the ability of dual endothelin (ET) receptor antagonists (ETA/ETB -ETA/BRAs) to contrast the ET-1-induced effects on cultured human microvascular endothelial cells (HMVECs).

METHODS

Some cultured HMVECs were untreated, or treated with ET-1 (100nM) or transforming growth factor β1 (TGFβ1, 10ng/mL) alone for 6 days, in order to induce the endothelial-to-mesenchymal transition (EndoMT). Other cultured HMVECs were pre-treated for 1hr with ETA/BRAs bosentan (10μM) or macitentan (1μM, 10μM) before the stimulation with ET-1 for 6 days. At the end of treatments, a mechanical injury was induced to cultured HMVECs (by scratching the cell monolayer with a sterile tip), and then the cell ability to re-fill the damaged area was determined after 24hrs. EndoMT phenotype markers and monocyte chemoattractant protein-1 (MCP-1) were evaluated by qRT-PCR and Western blotting. Statistical analysis was performed using Mann-Whitney-U non-parametric test.

RESULTS

Both ET-1 and TGFβ1 induced EndoMT and the MCP-1 over-expression in cultured HMVECs, as well as reduced the process of endothelial cell damage repair. Pre-treatment with ETA/BRAs let cultured HMVECs to significantly restore the in vitro damage of the cell monolayer and antagonised the EndoMT process as well as the MCP-1 over-expression (range p<0.05 - p<0.001). Conversely, untreated or TGFβ1-treated HMVECs were found unaffected by the ETA/BRAs treatments.

CONCLUSIONS

The treatment with dual ETA/BRAs seems to partially restore the altered cell function induced by ET-1 in cultured endothelial cells, and might justify their therapeutic efficiency in clinical conditions characterised by increased concentrations of ET-1.

From microvasculature to fibroblasts: Contribution of anti-endothelial cell antibodies in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune disease characterized by skin and internal organ fibrosis, caused by microvascular dysfunction. In recent years, the hypothesis that anti-endothelial cell antibodies (AECA) play a key role in microvascular damage seems to be increasingly convincing. In fact, AECA can induce antibody-dependent cellular apoptosis and stimulate the microvasculature to release pro-inflammatory and pro-fibrotic cytokines. Human-microvascular-endothelial-cells (MVECs) were stimulated with SSc sera (with and without AECA) and with sera from healthy donors. The conditioned MVEC culture media were then added to fibroblast cultures obtained from control skin (CTR), non-affected skin of SSc patients (NA), and affected skin of the same sclerodermic (SSc) patients, respectively. AECA contributed to the MVEC increased release of endothelin-1 (ET-1) in the culture medium and to MVEC apoptosis. Fibroblast (CTR, NA, and SSc) proliferation was increased after treatment with AECA-positive conditioned media, compared to AECA-negative and control conditioned media. Furthermore, both AECA-positive (in major contribution) and AECA-negative conditioned media were responsible for alpha-smooth-muscle-actin (αSMA) over-expression in all fibroblast cultures, compared to control conditioned media. Fibroblast type I collagen synthesis was upregulated by both SSc conditioned media (with and without AECA). Finally, the synthesis of fibroblast transforming-growth-factor-beta (TGF-β) was statistically higher in AECA-positive conditioned media, compared to AECA-negative and control conditioned media. These findings support the concept that AECA may mediate the crosstalk between endothelial damage and dermal-fibroblast activation in SSc.

Proteomic Investigation of Dermal Fibroblasts Isolated from Affected and Unaffected Skin Samples from Patients with Limited Cutaneous Systemic Sclerosis: 2 Distinct Entities?

Objective.

To identify using proteomic analysis the proteins of altered abundance in the affected and unaffected limited cutaneous systemic sclerosis (lcSSc) skin fibroblasts.

Methods.

Excision biopsies (3 mm) were obtained from the affected and unaffected skin of 5 patients with lcSSc. Dermal fibroblasts were isolated enzymatically. Two-dimensional gel electrophoresis was used to separate and define proteins in affected and unaffected fibroblast lysates. Proteins of altered abundance were identified by mass spectrometry. Differences among skin samples were confirmed also by immunohistochemistry (IHC) and by quantitative real-time PCR (qRT-PCR) for type I collagen (Col-1) and vimentin (VIM).

Results.

Proteomic analysis revealed different expressions of proteins involved in cytoskeleton organization (27%), extracellular matrix remodeling (11%), response to oxidative stress (22%), energy metabolism (19%), protein metabolism (5%), cellular homeostasis (5%), signal transduction (3%), and protein transcription, synthesis, and turnover (8%). IHC analysis showed that SSc-affected epidermis is thickened and the dermis is strongly reactive to Col-1 and VIM (typical markers of activated myofibroblasts) compared to SSc-unaffected skin, whose stainings are comparable to those of control healthy skin. Overexpression of Col-1 and VIM mRNA levels in affected lcSSc fibroblasts compared to unaffected lcSSc ones was confirmed by qRT-PCR.

Conclusion.

Consistent with previous studies, these findings are important for 2 reasons: first, because they reveal the opposite behavior of dermal fibroblasts in the unaffected and affected skin areas of the same patient with lcSSc; second, because they demonstrate the histological/histochemical similarities between unaffected skin from patients with lcSSc and healthy control skin.

Bosentan and macitentan prevent the endothelial-to-mesenchymal transition (EndoMT) in systemic sclerosis: in vitro study

BACKGROUND

Systemic sclerosis (SSc) is characterized by early vascular abnormalities and subsequent fibroblast activation to myofibroblasts, leading to fibrosis. Recently, endothelial-to-mesenchymal transition (EndoMT), a complex biological process in which endothelial cells lose their specific markers and acquire a mesenchymal or myofibroblastic phenotype, has been reported in SSc. In the present study, we evaluated the ability of endothelin-1 (ET-1) dual receptor antagonists bosentan (BOS) and macitentan (MAC) to antagonize EndoMT in vitro.

METHODS

Ten women with limited SSc were enrolled. They underwent double skin biopsy (affected and nonaffected skin). Fibroblasts and microvascular endothelial cells (MVECs) were isolated from biopsies. We performed mono- or coculture of MVECs (isolated from nonaffected skin) with fibroblasts (isolated from affected skin and stimulated with ET-1 and transforming growth factor beta [TGF-β]). In cocultures, the MVEC layer was left undisturbed or was preincubated with BOS or MAC. After 48 h of coculture, MVECs were analyzed for their tube formation ability and for messenger RNA and protein expression of different vascular (CD31, vascular endothelial growth factor-A [VEGF-A], VEGF-A165b) and profibrotic (alpha-smooth muscle actin [α-SMA], collagen type I [Col I], TGF-β) molecules.

RESULTS

After 48 h, MVECs showed a reduced tube formation ability when cocultured with SSc fibroblasts. CD31 and VEGF-A resulted in downregulation, while VEGF-A165b, the antiangiogenic isoform, resulted in upregulation. At the same time, mesenchymal markers α-SMA, Col I, and TGF-β resulted in overexpression in MVECs. Tube formation ability was restored when MVECs were preincubated with BOS or MAC, also reducing the expression of mesenchymal markers and restoring CD31 expression and the imbalance between VEGF-A and VEGF-A165b.

CONCLUSIONS

With this innovative EndoMT in vitro model realized by coculturing nonaffected MVECs with affected SSc fibroblasts, we show that the presence of a myofibroblast phenotype in the fibroblast layer, coupled with an ET-1-TGF-β synergic effect, is responsible for EndoMT. BOS and MAC seem able to antagonize this phenomenon in vitro, confirming previous evidence of endothelium-derived fibrosis in SSc and possible pharmacological interference.

Histopathological findings in systemic sclerosis-related myopathy: fibrosis and microangiopathy with lack of cellular inflammation

OBJECTIVES

The objective of this study was to identify specific histopathological features of skeletal muscle involvement in systemic sclerosis (SSc) patients.

METHODS

A total of 35 out of 112 SSc-patients (32%, including 81% female and 68% diffuse scleroderma) presenting clinical, biological and electromyographic (EMG) features of muscle weakness, were included. Patients underwent vastus lateralis biopsy, assessed for individual pathologic features including fibrosis [type I collagen (Coll-I), transforming growth factor β (TGF-β)], microangiopathy [cluster of differentiation 31 (CD31), pro-angiogenic vascular endothelial growth factor A (VEGF-A), anti-angiogenic VEGF-A165b], immune/ inflammatory response [CD4, CD8, CD20, human leucocyte antigens ABC (HLA-ABC)], and membranolytic attack complex (MAC). SSc biopsies were compared with biopsies of (n = 35) idiopathic inflammatory myopathies (IIMs) and to (n = 35) noninflammatory myopathies (NIMs). Ultrastructural abnormalities of SSc myopathy were also analyzed by transmission electron microscopy (TEM).

RESULTS

Fibrosis in SSc myopathy (81%) is higher compared with IIM (32%, p < 0.05) and with NIM (18%, p < 0.05). Vascular involvement is dominant in SSc muscle (92%), and in IIM (78%) compared with NIM (21%, p < 0.05). In particular, CD31 shows loss of endomysial vessels in SSc myopathy compared with IIM (p < 0.05) and with NIM (p < 0.01). VEGF-A is downregulated in SSc myopathy compared with IIM (p < 0.05) and NIM (p < 0.05). Conversely, VEGF-A165b is upregulated in SSc myopathy. The SSc immune/inflammatory response suggested humoral process with majority (85%) HLA-ABC fibral neoexpression and complement deposits on endomysial capillaries MAC, compared with IIM (p < 0.05), characterized by CD4⁺/CD8⁺/B-cell infiltrate, and NIM (p < 0.05). TEM analysis showed SSc vascular alterations consisting of thickening and lamination of basement membrane and endothelial cell 'swelling' coupled to endomysial/perimysial fibrosis.

CONCLUSIONS

Fibrosis, microangiopathy and humoral immunity are predominant in SSc myopathy, even if it is difficult to identify specific histopathological hallmarks of muscle involvement in SSc, since they could be present also in other (IIM/NIM) myopathies.

Serum levels, tissue expression and cellular secretion of macrophage migration inhibitory factor in limited and diffuse systemic sclerosis

OBJECTIVES

To investigate serum levels, tissue/cellular expression of macrophage migration inhibitory factor (MIF) in patients with limited (lSSc) and diffuse (dSSc) systemic sclerosis.

METHODS

10 lSSc-patients, 10 dSSc-patients and 10 controls were enrolled. MIF serum levels were assayed by ELISA. MIF and its receptors CD74/CD44 were evaluated by immunohistochemistry on skin biopsies from patients with dSSc, lSSc (affected and not-affected skin) and controls. MIF levels were assessed (ELISA) in supernatants of healthy dermal microvascular endothelial cells (MVECs) and in control (CTR), non-affected SSc (NA) and affected (SSc) fibroblasts treated for 48 h with 10% control serum and 10% SSc-serum. MIF supernatant (ELISA) and mRNA (quantitative real-time PCR) levels were determined in SSc dermal fibroblasts and in control dermal fibroblasts untreated or stimulated at 6 h-24 h-48 h with bleomycin (50 mU/ml).

RESULTS

Serum MIF was significantly higher in dSSc (18.7±4.1 ng/ml, p<0.001) and in lSSc (10.4±4.4 ng/ml, p<0.001) patients respect to controls (2.6±1.4 ng/ml). Enhanced MIF immunoreactivity was found in keratinocytes, fibroblasts, endothelium, sebaceous/sweat glands from lSSc/dSSc affected skin. Faint MIF immunoreactivity was found in control skin and not-affected skin of lSSc patients. No differences were found in CD74/CD44 receptors' analysis among control and dSSc/lSSc affected and non-affected skin. MVECs and fibroblasts (CTR, NA and SSc) produced significantly more MIF, when stimulated with SSc serum respect to control-serum (p<0.001). Finally, MIF mRNA levels significantly increased at 6h (p<0.001) and decreased at 48 h (p<0.001) in control fibroblasts treated with bleomycin compared to control untreated. Simultaneously, MIF supernatant protein levels increased after 48 h (p<0.01) in bleomycin-treated fibroblasts respect to untreated ones.

CONCLUSIONS

These results suggest that MIF could be implicated in the pathogenesis of SSc, probably acting as protective factor against the SSc stressful conditions.

Pulmonary hypertension: a correct diagnosis for a suitable therapy in scleroderma patients

Systemic sclerosis (SSc) is a heterogeneous disorder characterised by dysfunction of the endothelium and dysregulation of fibroblasts, resulting in excessive production of collagen, and abnormalities of the immune system. Progressive fibrosis of the skin and internal organs is a pathologic hallmark of the disease, resulting in major organ damage and failure. Pulmonary hypertension (PH) is frequent in patients with SSc and, pulmonary arterial hypertension (PAH) represents one of the main causes of death. PH is not a specific disease, but a haemodynamic condition characterized by a mean pulmonary pressure ≥25mmHg. In SSc, because of the great variability in clinical manifestation, it is possible to identify pulmonary hypertension due to left heart disease, PH due to respiratory disease or pulmonary arterial hypertension. The knowledge of PH and the right diagnosis are crucial to assess the most appropriate therapeutic strategy. In this article, the new classification criteria of PH have been examined taking into account the SSc clinical evolution and focusing on the different underlying pathogenetic mechanisms.

Is osteopontin involved in cutaneous fibroblast activation? Its hypothetical role in scleroderma pathogenesis

Osteopontin (OPN) is an extracellular matrix protein implicated in bone remodeling, but it presents also pro-inflammatory and pro-fibrotic properties. OPN expression also occurs upon exposure of cells to classical mediators of acute inflammation such as tumor necrosis growth factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta), as well as fibrogenic cytokines such as transforming growth factor beta (TGF-beta), although a detailed understanding of these regulatory pathways is still unknown. Plasma OPN levels in both limited and diffuse systemic sclerosis patients (lSSc and dSSc) were statistically higher compared to those of control subjects. Immunohistology demonstrated that high TGF-beta levels, alpha smooth muscle actin (alphaSMA) levels and consequently high OPN levels were found in the affected skin of sclerodermic patients (lSSc and dSSc) compared to levels found in healthy skin. In order to better understand how OPN interferes with the fibrotic process, healthy skin fibroblasts were treated for 24 and 48 hours with bleomycin and with endothelin-1 (ET-1) plus TGF-beta in order to induce the fibrogenesis. After 48 hours of stimulation, healthy treated fibroblasts showed statistically increased alphaSMA levels (index of differentiation into myofibroblasts) and simultaneously statistically increased OPN levels compared to healthy untreated ones. This study demonstrates that OPN levels increase simultaneously with the increasing of alphaSMA levels, therefore it is reasonable to hypothesize that OPN interferes in the pathogenesis of Systemic Sclerosis in the early stage of fibroblast differentiation process.

Collagen-gelatin-genipin-hydroxyapatite composite scaffolds colonized by human primary osteoblasts are suitable for bone tissue engineering applications: in vitro evidences

The application of porous hydroxyapatite (HAp)-collagen as a bone tissue engineering scaffold represents a new trend of mimicking the specific bone extracellular matrix (ECM). The use of HAp in reconstructive surgery has shown that it is slowly invaded by host tissue. Therefore, implant compatibility may be augmented by seeding cells before implantation. Human primary osteoblasts were seeded onto innovative collagen-gelatin-genipin (GP)-HAp scaffolds containing respectively 10%, 20%, and 30% HAp. Cellular adhesion, proliferation, alkaline phosphatase (ALP) activity, osteopontin (OPN), and osteocalcin (OC) expressions were evaluated after 3, 7, 15, and 21 days. The three types of scaffolds showed increased cellular proliferation over time in culture (maximum at 21 days) but the highest was recorded in 10% HAp scaffolds. ALP activity was the highest in 10% HAp scaffolds in all the times of evaluation. OC and OPN resulted in higher concentration in 10% HAp scaffolds compared to 20% and 30% HAp (maximum at 21 days). Finally, scanning electron microscopy analysis showed progressive scaffolds adhesion and colonization from the surface to the inside from day 3 to day 21. In vitro attachment, proliferation, and colonization of human primary osteoblasts on collagen-GP-HAp scaffolds with different percentages of HAp (10%, 20%, and 30%) all increased over time in culture, but comparing different percentages of HAp, they seem to increase with decreasing of HAp component. Therefore, the mechanical properties (such as the stiffness due to the HAp%) coupled with a good biomimetic component (collagen) are the parameters to set up in composite scaffolds design for bone tissue engineering.

Proteomics of human primary osteoarthritic chondrocytes exposed to extremely low-frequency electromagnetic fields (ELF EMFs) and to therapeutic application of musically modulated electromagnetic fields (TAMMEF)

Osteoarthritis (OA) is the most frequent joint disease, characterized by degradation of extracellular matrix and alterations in chondrocyte metabolism. Some authors reported that electromagnetic fields (EMFs) can positively interfere with patients affected by OA, even though the nature of the interaction is still debated. Human primary osteoarthritic chondrocytes isolated from the femoral heads of OA-patients undergoing to total hip replacement, were cultured in vitro and exposed 30 min/day for two weeks to extremely-low-frequency electromagnetic field (ELF) with fixed frequency (100 Hz) and to therapeutic application of musically modulated electromagnetic fields (TAMMEF) with variable frequencies, intensities and waveforms. Sham-exposed (S.E.) cells served as control group. Cell viability was measured at days 2, 7 and 14. After two weeks, cell lysates were processed using a proteomic approach. Chondrocyte exposed to ELF and TAMMEF system demonstrated different viability compared to untreated chondrocytes (S.E.). Proteome analysis of 2D-Electrophoresis and protein identification by mass spectrometry showed different expression of proteins derived from nucleus, cytoplasm and organelles. Function analysis of the identified proteins showed changes in related-proteins metabolism (glyceraldeyde-3-phosphate-dehydrogenase), stress response (Mn-superoxide-dismutase, heat-shock proteins), cytoskeletal regulation (actin), proteinase inhibition (cystatin-B) and inflammation regulatory functions (S100-A10, S100-A11) among the experimental groups (ELF, TAMMEF and S.E.). In conclusion, EMFs do not cause damage to chondrocytes, besides stimulate safely OA-chondrocytes and are responsible of different protein expression among the three groups. Furthermore, protein analysis of OA-chondrocytes treated with ELF and the new TAMMEF systems could be useful to clarify the pathogenetic mechanisms of OA by identifying biomarkers of the disease.

Macitentan slows down the dermal fibrotic process in systemic sclerosis: in vitro findings

Systemic sclerosis (or scleroderma) is an autoimmune disease characterized by skin and internal organ fibrosis, caused by microvascular dysfunction. The microvascular damage seems to be a consequence of an endothelial autoimmune response, followed by activation of the inflammatory cascade and massive deposition of collagen. Endothelin-1 (ET-1) contributes to the inflammatory and fibrotic processes by increasing the concentration of pro-inflammatory and pro-fibrotic cytokines, and it is considered one of the most relevant mediators of vascular damage in scleroderma. It is indeed found in very high concentration in serum of sclerodermic patients. Moreover, in these pathological conditions there is an increased expression of ET-1 receptors (ETA and ETB), which mediate the detrimental action of ET-1, and often a change of ETA/ETB ratio. The aim of the present study is to evaluate the in vitro effect of macitentan, an orally active tissue-targeting dual endothelin receptor antagonist, and its major metabolite (ACT-132577) on alpha smooth muscle actin (alphaSMA) expression, evaluated on dermal fibroblasts from healthy subjects and on dermal fibroblasts from lesional and non-lesional skin from sclerodermic patients. The combination of macitentan and its major metabolite reduced the levels of &#945;SMA after 48 h in sclerodermic fibroblasts from lesional skin. No relevant changes in &#945;SMA levels were found in fibroblasts from non-lesional skin, whose behavior is similar to that of dermal fibroblasts from healthy patients.

Human osteoarthritic chondrocytes exposed to extremely low-frequency electromagnetic fields (ELF) and therapeutic application of musically modulated electromagnetic fields (TAMMEF) systems: a comparative study

Osteoarthritis (OA) is the most common joint disease, characterized by matrix degradation and changes in chondrocyte morphology and metabolism. Literature reported that electromagnetic fields (EMFs) can produce benefits in OA patients, even if EMFs mechanism of action is debated. Human osteoarthritic chondrocytes isolated from femoral heads were cultured in vitro in bidimensional (2-D) flasks and in three-dimensional (3-D) alginate beads to mimic closely cartilage environment in vivo. Cells were exposed 30 min/day for 2 weeks to extremely low-frequency electromagnetic field (ELF) with fixed frequency (100 Hz) and to therapeutic application of musically modulated electromagnetic field (TAMMEF) with variable frequencies, intensities, and waveforms. Cell viability was measured at days 7 and 14, while healthy-cell density, heavily vacuolized (hv) cell density, and cluster density were measured by light microscopy only for 3-D cultures after treatments. Cell morphology was observed for 2-D and 3-D cultures by transmission electron microscopy (TEM). Chondrocyte exposure to TAMMEF enhances cell viability at days 7 and 14 compared to ELF. Light microscopy analysis showed that TAMMEF enhances healthy-cell density, reduces hv-cell density and clustering, compared to ELF. Furthermore, TEM analysis showed different morphology for 2-D (fibroblast-like) and 3-D (rounded shape) cultures, confirming light microscopy results. In conclusion, EMFs are effective and safe for OA chondrocytes. TAMMEF can positively interfere with OA chondrocytes representing an innovative non-pharmacological approach to treat OA.

Erythema nodosum associated with Staphylococcus xylosus septicemia

Staphylococcus xylosus is a coagulase-negative staphylococcus. It is a commensal bacterium associated with skin and mucous membranes and occasionally it can cause human infections. We report the first case of erythema nodosum developed in a young woman with S. xylosus septicemia and specific serum antibody response.

Therapeutic Application of Musically Modulated Electromagnetic Fields in the Treatment of Musculoskeletal Disorders

Different studies have demonstrated the efficacy of extremely low frequency electromagnetic fields (ELF EMFs) in the treatment of pain. In particular, the positive effects of ELF EMFs seems to depend on their respective codes, such as frequency, intensity and waveform, even if the exact mechanism of interaction is still debated. The most commonly used for extremely low frequency magnetotherapy is a 100Hz sinusoidal field (ELF) with a mean of induction of few Gauss. This article reviews the therapeutic application of a musically modulated electromagnetic field (TAMMEF), a new-generation of electromagnetic field used for extremely low frequency magnetotherapy characterized by variable frequencies, intensities and waveforms. Both clinical and experimental studies, performed by authors of the present review, have demonstrated the efficacy of ELF and the new TAMMEF systems in several musculoskeletal disorders such as osteoarthritis, rheumatoid arthritis, carpal tunnel syndrome, shoulder periarthritis and cervical spondylosis. Moreover, it has been demonstrated that ELF and TAMMEF systems are not only effective, but also safe, from clinical and experimental point of view. In fact, clinical trials did not reported any undesired side effect, while in vitro studies showed that ELF EMFs did not induce uncontrolled cell proliferation, did not affect cell viability and did not induce apoptosis. With their efficacy and safety, ELF and even more the new TAMMEF systems represent a valid complementary or alternative treatment to standard pharmacological therapies in reducing both pain and inflammation of patients affected by musculoskeletal disorders.

In vitro exposure of human osteoarthritic chondrocytes to ELF fields and new therapeutic application of musically modulated electromagnetic fields: biological evidence

Osteoarthritis (OA) is the most frequently occurring rheumatic disease, caused by metabolic changes in chondrocytes, the cells that maintain cartilage. Treatment with electromagnetic fields (MF) produces benefits in patients affected by this pathology. Isolated human osteoarthritic (OA) chondrocytes were cultured in vitro under standard conditions or stimulated with IL-1beta or IGF-1, to mimic the imbalance between chondroformation and chondroresorption processes observed in OA cartilage in vivo. The cells were exposed for a specific time to extremely low frequency (ELF; 100-Hz) electromagnetic fields and to the Therapeutic Application of Musically Modulated Electromagnetic Fields (TAMMEF), which are characterized by variable frequencies, intensities, and waveforms. Using flow cytometry, we tested the effects of the different types of exposure on chondrocyte metabolism. The exposure of the cells to both systems enhances cell proliferation, does not generate reactive oxygen species, does not cause glutathione depletion or changes in mitochondrial transmembrane potential and does not induce apoptosis. This study presents scientific support to the fact that MF could influence OA chondrocytes from different points of view (viability, ROS production and apoptosis). We can conclude that both ELF and TAMMEF systems could be recommended for OA therapy and represent a valid non-pharmacological approach to the treatment of this pathology.

Dapsone-Associated Methaemoglobinaemia in Patients with a Haematologic Malignancy

Methaemoglobinaemia is an uncommon problem which can significantly impact on oxygen carriage and may necessitate intensive care management. The occurrence of symptomatic methaemoglobinaemia over a three-month period in four patients with haematological malignancies on dapsone for Pneumocystis jiroveci pneumonia prophylaxis prompted a review of its use in this group of patients. We performed a retrospective audit to identify any contributing factors. Co-oximetry was employed to identify patients with methaemoglobinaemia. Thirty-four patients with haematological malignancies received dapsone between January and December 2008, of whom 53% (n=18) had co-oximetry studies done. Raised methaemoglobin levels (≥1.5%) were seen in 13 patients, four of them symptomatic. Mean peak level was of 7.84% (range 1.9 to 26.8%). Eight patients required intensive care support. Mean onset of methaemoglobinaemia was 11.8 days (range 4 to 18 days) following dapsone commencement. All patients were anaemic with an average haemoglobin of 85.5 g/l (range 59 to 111 g/l). All patients were prescribed ‘azole’ antifungal agents and five patients were also on high-dose steroids, both agents known to induce cytochrome P-450 enzymes and hence potentiating dapsone toxicity. Our experience suggests that dapsone should be used with caution in patients with haematological malignancies as they are particularly at risk of developing symptomatic methaemoglobinaemia due to underlying anaemia, immunosuppression and potential drug interactions. The current recommendation of dapsone for Pneumocystis jiroveci pneumonia prophylaxis in this group of patients needs to be reviewed. When methaemoglobinaemia does occur, early recognition is possible with routine co-oximetry testing and prompt treatment may lessen the need for or duration of intensive care supports.