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

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

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.

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.

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.

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.

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.