Developmental and Nutritional Dynamics of Malpighian Tubule Autofluorescence in the Asian Tiger Mosquito Aedes albopictus

Malpighian tubules (MTs) are arthropod excretory organs crucial for the osmoregulation, detoxification and excretion of xenobiotics and metabolic wastes, which include tryptophan degradation products along the kynurenine (KYN) pathway. Specifically, the toxic intermediate 3-hydroxy kynurenine (3-HK) is metabolized through transamination to xanthurenic acid or in the synthesis of ommochrome pigments. Early investigations in Drosophila larval fat bodies revealed an intracellular autofluorescence (AF) that depended on tryptophan administration. Subsequent observations documented AF changes in the MTs of Drosophila eye-color mutants genetically affecting the conversion of tryptophan to KYN or 3-HK and the intracellular availability of zinc ions. In the present study, the AF properties of the MTs in the Asian tiger mosquito, Aedes albopictus, were characterized in different stages of the insect's life cycle, tryptophan-administered larvae and blood-fed adult females. Confocal imaging and microspectroscopy showed AF changes in the distribution of intracellular, brilliant granules and in the emission spectral shape and amplitude between the proximal and distal segments of MTs across the different samples. The findings suggest AF can serve as a promising marker for investigating the functional status of MTs in response to metabolic alterations, contributing to the use of MTs as a potential research model in biomedicine.

AB0092 CTLA4-Ig PROMOTES THE M1-M2 SHIFT IN CULTURED MACROPHAGES OF RHEUMATOID ARTHRITIS PATIENTS WITH ACTIVE DISEASE: IN VITRO STUDY

Background

In rheumatoid arthritis (RA), macrophages play an important role in modulating the immunoinflammatory response through their polarization into “classically” (M1) or “alternatively activated” (M2) phenotypes and the release of pro-inflammatory cytokines (1). In the active inflammatory phase of RA, circulating intermediate monocytes and synovial tissue macrophages show a M1 phenotype, whereas MerTK+M2 macrophages seem to characterize the synovial tissue of RA patients under remission (2-4). In RA, CTLA4-Ig fusion protein (abatacept) reduces the pro-inflammatory activity of macrophages by interacting with the costimulatory molecule CD86 on surface cell membrane of activated cells, including macrophages (2).

Objectives

The in vitro study investigated the efficacy of CTLA4-Ig treatment to induce the shift from the M1 phenotype into an M2 phenotype in cultured monocyte-derived macrophages (MDMs) obtained from active RA patients.

Methods

Cultured MDMs obtained from peripheral blood mononuclear cells of 5 active RA patients (mean age 54±13 years) and 5 age-matched healthy subjects (HSs) after overnight stimulation with phorbol myristate acetate (5ng/ml), were treated with CTLA4-Ig at the concentrations of 100mg/mL or 500mg/mL for 3, 12, 24 and 48 hours. A part of cultured RA-MDMs as wells as cultured HS-MDMs were maintained in growth medium (RPMI at 10% of fetal bovine serum) without any treatment and used as unstimulated cells. Gene expression of CD80, CD86 and toll-like receptor-4 (TLR4), as M1 markers, as well as macrophage scavenger receptors (CD163, CD204), mannose receptor-1 (CD206), as surface M2 markers, and MerTK (functional M2 marker) were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Protein synthesis of surface M2 markers was investigated by Western blotting. The statistical analysis was performed by Wilcoxon t-test.

Results

Cultured RA-MDMs showed a high basal gene expression of TLR4, CD80 and CD86 compared to HS-MDMs, confirming to be activated M1 macrophages. In these macrophages, CTLA4-Ig treatment downregulated the gene expression of M1 markers at both concentrations and all timings, but significantly limited to TLR4 and CD80 markers (500mg/mL,12 hours: p<0.05). Conversely, both concentrations of CTLA4-Ig significantly upregulated the gene expression of CD163, MerTK and CD206 (p<0.05), whereas only the high concentration of CTLA4-Ig significantly upregulated CD204 gene expression (p<0.05). The protein synthesis of all M2 surface markers was increased after 24 hours of treatment primarily by the high concentration of CTLA4-Ig, and significantly for CD204 and CD206 (p<0.05).

Conclusion

CTLA4-Ig treatment seems to exert an important anti-inflammatory effect by promoting the shift from a M1 to an M2 phenotype in cultured RA macrophages The results suggest a further mechanism for CTLA4-Ig in the modulation of the RA synovitis (5).

References

[1]Yang X et al. Cell Prolif. 2020;53:e12854.doi:10.111/cpr.12854.

[2]Kumar RA et al. Int. Immunol.2018;65:348-59.

[3]Boutet MA et al. Autoimmun Rev.2021;20:102758. doi: 10.1016/j.autrev.2021.102758.

[4]Alivernini S et al. Nat Med. 2020;26:1295-306. 5. Cutolo M et al. Arthritis Res Ther. 2009;11:R176; doi: 10.1186/ar2865.

Disclosure of Interests

Maurizio Cutolo Grant/research support from: Bristol-Myers Squibb, Celgene, Pfizer, Boehringer Ingelheim, Samuele Tardito: None declared, Emanuele Gotelli: None declared, Paola Montagna: None declared, Rosanna Campitiello: None declared, Sabrina Paolino: None declared, Carmen Pizzorni: None declared, Alberto Sulli Grant/research support from: Laboratories Baldacci, Vanessa Smith Grant/research support from: Boehringer Ingelheim, Janssen-Cilag, Stefano Soldano: None declared

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

AB0057 IN VITRO EFFECT OF CTLA4-IGG ON M1-M2 SHIFT OF MACROPHAGES FROM RHEUMATOID ARTHRITIS PATIENTS

Background:

Among the cells involved in the inflammatory process of rheumatoid arthritis (RA) [1], macrophages play a key role through their capacity to polarize into “classically” or “alternatively” activated phenotypes (M1 or M2) and making macrophages important players for the inflammatory cascade or for the anti-inflammatory reaction, respectively [2]. CTLA4-Ig fusion protein (abatacept) has been shown to contribute to macrophage shift from M1 to M2 [3].

Objectives:

We aimed to investigate the effects of abatacept to induce the polarization from the pro-inflammatory M1 phenotype into the anti-inflammatory M2 phenotype in cultured human macrophages obtained from RA patients’ and healthy subjects’(HS) circulating monocytes.

Methods:

Cultured monocytes were isolated from peripheral blood mononuclear cells (PBMCs) of three early RA patients and ten HS, after signing informed consent and Ethics Committee approval. Cells were treated with phorbol myristate acetate (PMA) [5ng/ml] for 24 hours (hrs) to induce their differentiation into monocyte-derived macrophages (MDMs). Therefore, cultured HS MDMs were stimulated with lipopolysaccharides [LPS, 1mg/mL] for 4hrs [4] in order to induce their polarization into a pro-inflammatory M1 phenotype and then treated or not with abatacept at the concentrations of 100mg/mL and 500mg/mL for 3, 12, 24 and 48hrs. Cultured RA MDMs, were directly treated with abatacept as previous described. Cultured HS and RA MDMs without any pro-inflammatory stimuli and abatacept treatment were used as respective control.

The transition of MDMs from M1 to M2 phenotype was evaluated through gene expression and protein synthesis of M2 macrophage markers, namely scavenger receptors (CD163 and CD204), and mannose receptor-1 (CD206) by quantitative real-time polymerase chain reaction (PCR) and by Western blotting. The statistical analysis evaluation was carried out by GraphPad Prism 8 analysis software using the Wilcoxon non-parametric t-test. Any p-value lower than 0.05 was considered as statistically significant. Results were indicated as median±standard deviation (SD).

Results:

In cultured RA MDMs (three cases), abatacept upregulated the gene expression of all investigated M2 markers, specifically after 12hrs of treatment with the concentration of 100mg/mL. In these cells, abatacept upregulated only the CD204 protein synthesis with more evidence at 24hrs of treatment and with the 500mg/mL concentration. In cultured HS MDMs (ten cases), abatacept upregulated the gene expression of M2 markers, significantly for that of CD206 [at 3hrs with 100mg/mL concentration, p= 0.0312] and CD163 [at 12hrs with 500mg/mL concentration, p= 0.0312]. Moreover, in these cells, abatacept significantly upregulated the protein synthesis of CD206 [at 48hrs with 500mg/mL concentration, p= 0.0195] and CD204 [at 24hrs with 100mg/mL concentration, p= 0.0156; both at 24 and 48hrs with 500mg/mL concentration, p= 0.0234].

Conclusion:

Preliminary data seem to indicate that abatacept can promote the in vitro shift from the M1 into the M2 macrophage phenotype, by upregulating specific markers (CD163, CD204, CD206) in cultured M1-MDMs from RA patients and in M1 macrophages induced from HS.

References:

[1]McInnes IB, et al. N Engl J Med 2011;365:2205–19.

[2]Fujii M, et al. Biochem Biophys Res Commun. 2013;438(1):103-9.

[3]Cutolo M, et al. Arthritis Res Ther. 2009;11:R176.

[4]Pelegrin P., Surprenant, A. EMBO J. 2009 Jul 22; 28(14): 2114–2127.

Disclosure of Interests:

Samuele Tardito: None declared, Stefano Soldano: None declared, Emanuele Gotelli: None declared, Paola Montagna: None declared, Sabrina Paolino: 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

SAT0301 CIRCULATING FIBROCYTES FROM SYSTEMIC SCLEROSIS PATIENTS AS POSSIBLE TARGET OF CTLA4-IG TREATMENT: AN IN VITRO STUDY

Background:

muscle actin (aSMA)+cells involved in the overproduction of extracellular matrix proteins, primarily fibronectin (FN) and type I collagen (COL1) at the level of damaged tissues (1). These cells may originate from different cell types including fibroblasts, endothelial and epithelial cells, and fibrocytes (1). Circulating fibrocytes are bone marrow progenitor cells expressing specific markers of hematopoietic (CD34, CD45, and MHC class II) and stromal cells (COL1 and COL3), chemokine receptors (CCR2, CCR7), and CXCR4 (2). CXCR4 regulates fibrocyte migration into injured tissues allowing their differentiation into fibroblasts/myofibroblasts (2).

In vitro, fibrocytes differentiate from circulating CD14+monocytes showing an antigen-presenting capability through the expression of HLA-DR and costimulatory molecule CD86 (2). CTLA4-Ig fusion protein (abatacept) interacts with CD86 on cell surface of antigen presenting cells (APCs), such as macrophages and endothelial cells (3,4).

Objectives:

To investigate the possible effect of CTLA4-Ig treatment on cultured human fibrocytes and skin fibroblasts isolated from the same systemic sclerosis patients (SSc pts).

Methods:

Fibrocytes isolated from the peripheral blood mononuclear cells of SSc pts and healthy subjects (HSs) were cultured on fibronectin-coated plates in DMEM at 20% of FBS; for further 8 days (T8) to allow their complete differentiation. Differentiated fibrocytes were maintained in growth medium or treated with CTLA4-Ig at different concentrations (10, 50, 100, and 500μg/ml) for 3 hours. Fibroblasts were isolated from the skin biopsies of the same patients and HSs, cultured until the 3rdpassage in RPMI at 10% FBS and then treated with CTLA4-Ig for 24 and 48 hours. Fibrocytes were characterized as CD45+CXCR4+COL1+cells and the expression of CD86 and HLA-DR was also evaluated. The gene expression of aSMA, COL1, CXCR4, TGFb1 and CD86 was investigated by quantitative real-time polymerase chain reaction in cultured fibrocytes and skin fibroblasts. In cultured skin fibroblasts, COL1 and fibronectin synthesis was evaluated by Western blotting.

Results:

Treatment with CTLA4-Ig for 3 hours significantly downregulated aSMA and COL1 gene expression in cultured SSc fibrocytes at T8 (p<0.01, p<0.05 vs. untreated fibrocytes), whereas no modulatory effect was observed on the TGFbeta1 and CXCR4 gene expression. In cultured SSc skin fibroblasts, CTLA4-Ig did not induce any significant effect on CD68, TGFb1, COL1 and FN gene expression as well as COL1 and FN protein synthesis, both after 24 and 48 hours. Of note, these cultured SSc skin fibroblasts showed a low expression of CD86.

Conclusion:

Due to their high expression of CD86, circulating fibrocytes seem to be more responsive to CTLA4-Ig treatment than the skin fibroblasts isolated from the same SSc patient.

References:

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

[2]Bucala R. Mol Med.2015;2:S3-5.

[3]Cutolo M et al. Clin Exp Rheumatol. 2015;33:250-4.

[4]Brizzolara R et al. J Rheumatol. 2013;40:738-40.

Disclosure of Interests:

Stefano Soldano: None declared, Paola Montagna: None declared, Sabrina Paolino: None declared, Elisa Alessandri: 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

Anterior approach to the spine. Role of the general surgeon, techniques and surgical complications. The 10-year experience of the Niguarda Hospitals

AIM

The aim of the study was to present the incidence of early and late surgical complications in a group of patients treated with anterior approach for spine lesions. The study was also focused on technical aspects for lesions of D1-D2 and L5-S1 segments and results on a group of patients underwent adjunctive surgical procedures at the same time of spinal surgery.

METHODS

This was a retrospective study based on our database from April 1998 to December 2008. The study enrolled 120 consecutive patients (M/F 73/47; mean age 43.1 years; range 15-70 years) who underwent spinal surgery for trauma (92 patients), primitive or metastatic cancer (12 patients), benign lesion (2 patients), degenerative disc disease (6 patients) and infection disease (8 patients). This work describes the anterior approach to the spine.

RESULTS

No death was recorded. Thirty-two patients (26.6%) presented postoperative complications: persistent urinary tract infections in 19 (15.9%), pneumonia in 6 (5%), pleural effusion in 3 (2.5%), wound infection in 2 (1.6%), retro-peritoneal abscess in 1 (0.8%) and haemorrhage in 1 (0.8%). During the follow-up (mean 3.8 years; range 2 months-10 years) 1 patient (0.8%) required two further surgical procedures for tuberculosis abscess recurrences.

CONCLUSION

Anterior approach to the spine is effective and safe. Surgical complications do not negatively affect patient survival and spine stabilization included patients with D1-D2 and L5-S1 lesion and patients who receive adjunctive surgery at the same time of spine procedure.

Endothelin and sex hormones modulate the fibronectin synthesis by cultured human skin scleroderma fibroblasts

Objective:

To evaluate the influence of endothelin-1 (ET-1) and sex hormones on cell proliferation and extracellular matrix (ECM) synthesis (ie, fibronectin, laminin) by cultured normal and scleroderma (SSc) human skin fibroblasts (FBs).

Methods:

Primary cultures of FBs were treated with ET-1 and sex hormones (17β-oestradiol or testosterone) for 24 h. Cell growth was analysed by methiltetrazolium salt test, ECM synthesis was evaluated by immunocytochemistry and western blot, both at 24 h.

Results:

In normal FBs, ET-1 and 17β-oestradiol, as well as their combination, increased cell growth (p<0.001, p<0.001, p<0.01 vs untreated cells (control), respectively) and fibronectin synthesis (p<0.05, p<0.05, p<0.01 vs control, respectively). By contrast, testosterone either alone or in combination with ET-1 did not influence cell proliferation, but decreased fibronectin synthesis (p<0.05, testosterone vs control). In SSc FBs, ET-1 and 17β-oestradiol alone or their combination induced an increased fibronectin synthesis (p<0.05, p<0.05, p<0.01 vs control, respectively). Unexpectedly, testosterone induced an increase of fibronectin synthesis (p<0.05 vs control).

Conclusions:

ET-1 and 17β-oestradiol seem to exert a profibrotic effect in normal and SSc culture FBs and might suggest their synergistic effect in the pathogenesis of the fibrotic process in SSc.

Hydroxylated estrogen metabolites influence the proliferation of cultured human monocytes: possible role in synovial tissue hyperplasia

INTRODUCTION

17Beta-estradiol, estrone, and several of their hydroxylated metabolites, have been found to be significantly increased in synovial fluid of rheumatoid arthritis (RA) patients. In this study, we investigated whether the estrogen metabolites are able to exert direct effects on monocyte cell proliferation, which is important in RA synovial tissue activation and growth.

METHODS

Human monocytes (THP-1) were treated with the following estrogen metabolites at different concentrations (from 10-8M, 10-9M, 10-10M to 10-11M) for 24, 48 and 72 hours: 16-hydroxyestrone (16OH-E1), 16-hydroxyestradiol (16OH-E2), 4-hydroxyestrone (4OH-E1), 4-hydroxyestradiol (4OH-E2), 2-hydroxyestrone (2OH-E1) and 2-hydroxyestradiol (2OH-E2). Monocytes were activated with interferon-gamma (INF-gamma). Cell cultures were also performed in presence of tamoxifen (10-7M) to evaluate whether the estrogen metabolites act through the estrogen receptors (ER). Cell growth was detected by MTT test and cell viability through the LDH release assay.

RESULTS

4OH-E1 and 2OH-E1 significantly increased cell growth at low concentration (10-10M), whereas they significantly reduced cell proliferation at high concentrations (10-9M). 16OH-E2 and 4OH-E2 induced opposite effects: cell proliferation at high concentration and antiproliferative action at low doses. On the contrary, 16OH-E1 and 2OH-E2 were found to be estrogen metabolites that induced cell proliferative effects for most of the tested doses. Tamoxifen caused the loss of effects on cell proliferation for almost all the metabolites.

CONCLUSION

This study first demonstrates that different downstream estrogen metabolites interfere with monocyte proliferation and generally might modulate the immune response. Therefore, since estrogen metabolite/ratios are altered in the synovial fluid of RA patients, they might play important roles at least in RA synovial tissue hyperplasia.

Renal Grafts From Elderly Donors: Histological Studies and Long-Term Results

To satisfy the increasing requests for renal grafts, elderly donors are increasingly accepted for kidney transplant at many centers. The main unresolved question is the long-term effect on graft survival of potential histological lesions due to donor age. We present a prospective histological study performed from January 1997 to December 2001 on 184 consecutively transplanted renal grafts in which the only criterion for graft acceptance was a normal value of serum creatinine upon admission to the intensive care unit independent of donor age. At the end of the study, 57 recipients (31%) of mean age 55 years (range 39 to 67 years) received a renal graft from donors aged more than 60 years (mean age 66 years; range 60 to 75 years), this cohort denoted as older donor kidney transplant group (ODKTG) and 127 recipients (69%) with a mean age of 49 years (range 21 to 63 years) received a renal graft from donors whose age was lower than 60 years (mean age 49 years; range 16 to 59 years), a cohort denoted as the younger donor kidney transplant group (YDKTG). The two groups were comparable for time of dialysis, cold ischemia time, immunosuppression therapy, grading of histological damage. At the end of the study with a mean follow-up of 5.6 years (range 3.5 to 7.5 years), primary graft nonfunction and delayed graft function were significantly more represented in the ODKTG than the YDKTG. Cumulative patient and graft survival was 84.3% and 79.4% in the ODKTG, respectively, and 93.8% and 85.9% in the YDKTG, respectively (P = NS). Cumulative serum creatinine values were 1.98 mg/100 mL in ODKTG and 1.65 mg/100 mL in YDKTG (P = NS). In conclusion, renal grafts from older donors presented histological damage comparable to that seen among renal grafts from younger donors.

Early and late residual renal function and surgical complications in living donors: a 15-year experience at a single institution

Living donation in the field of renal transplantation has increased over time as well as the use of laparoscopic nephrectomy. We present a 15-year experience on 162 living donors (105 women, 57 men; mean age, 46.7 years; range, 31-74 years) who underwent nephrectomy using different surgical approaches as open lombotomic nephrectomy (OLN), open transperitoneal nephrectomy (OTN), and laparoscopic hand-assisted nephrectomy (LHAN). We collected data on residual donor and recipient renal function, as well as early versus late medical and surgical complications. With a mean follow-up of about 8 years, we observed normal residual renal function in all donors and similar results of early and late graft function independent of the surgical procedure. Long-term incidence of hypertension and noninsulin-dependent diabetes in living donors was similar to the general population. OLN and OTN donors showed higher incidences of early and late complications, readmissions, and reoperations than LHAN donors. Our results confirmed that living donor nephrectomy is a safe procedure without serious side effects in terms of renal function and long-term quality of life. LHAN should be the preferred technique because of a lower incidence of early and late complications.

Pancreas Retransplantation: Ideal Timing and Early and Late Results

Surgical complications are the leading cause of pancreatic graft loss among diabetic patients who undergo pancreas transplantation alone (PTA), or combined with kidney transplantations (PK) or after kidney transplantations (PAK). Therapeutic effects on secondary complications of diabetes justify pancreas retransplantation (re-PT) when the first graft is lost. However, the appropriate timing for retransplant and related problems is not known. We present our initial experience on re-PT performed on seven diabetic patients who lost their first pancreas grafts (PK) due to surgical complications (venous thrombosis in five and enteric fistula in two). Five re-PT were performed a few days after the first PT without a second course of induction therapy, while two patients received re-PT some months later with reinduction therapy. In the early re-PT group, one patient died some hours after the second surgical procedure due to pulmonary embolism, while four patients lost their second grafts due to accelerated rejection within 2 years from re-PT. In the late re-PT group, both patients have good graft function without signs of rejection. Our initial experience showed discouraging results in the group of early re-PT, due to accelerated rejection episodes leading to a high incidence of graft loss. Late re-PT accompanied by reinduction therapy seemed to have better results.

Advantages of short-time ureteric stenting for prevention of urological complications in kidney transplantation: an 18-year experience

We retrospectively studied the incidence of urological complications in a consecutive series of 590 patients (group B) who received a kidney transplant (KT) with a ureteral stent from January 1994 to December 2002. The ureteral stent was sewn to the bladder catheter during the surgical procedure and left in situ for a mean time of 10 days (range 8 to 12 days). The results were compared to a consecutive series of 414 patients who received a KT from March 1986 to December 1993 without a ureteral stent (group A). The two groups were comparable in terms of donor and recipient gender, ischemia time, delayed graft function, and chronic rejection incidence, but differed in mean donor age (44.1 vs 36.0 years), mean recipient age (45.4 vs 39.1 years), living/cadaveric donor rate (19.8% vs 11.9%), arterial lesions and bench reconstruction rate (11.1 vs 3.5%), as well as acute rejection episodes (11.7% vs 29.2%). Complications were seen in nine patients in group B (1.5%) and 17 patients in group A (4.1%) (P < .0001). Urinary leaks presented in two patients in group B (0.3%) and 11 patients in Group A (2.6%; P < .0001), while stenosis was present in six patients in group B (1.5%) and 7 in group A (1.2%) (P = NS). Urological complications such as urinary tract infection and macroscopic hematuria were similar in both groups. Time to presentation of a leak was within 2 weeks from KT in 10 patients (92.3%), while stenosis presented early in four patients (one in group B and four in group A). Of the stenoses, 69.3% presented late (beyond 12 weeks) in five patients in group B and three in Group A. In conclusion, our data suggest that routine use of double pigtail ureteral stent significantly decreased the incidence of leaks and early stenoses, but it did not modify late stenosis incidence. In the last decade, risk factors for urological complications have been increasing over time, namely, older donors and older recipients, living donation, length of dialysis, and the use of grafts with arterial lesions. Therefore we believe that a ureteral stent should be routinely considered to afford the advantage to protect the urinary anastomosis in the early postoperative period when the incidence of complications is highest, without the need of cystoscopy for its removal.

Laparosopic Hand-Assisted Living Donor Nephrectomy: The Niguarda Experience

Perioperative donor morbidity, a barrier to living organ donation, may be mitigated by the laparoscopic approach. From September 2002 to September 2004, 15 living donors, of ages ranging from 36 to 59 years, underwent laparoscopic nephrectomy. We used a hand-assisted device to increase the safety of the procedure. The average operating time was 200 minutes. The average blood loss was about 100 mL. The patients resumed oral intake and started walking within 1 day. The average postoperative hospital stay was 6 days. Although laparoscopic operating times were longer than those for traditional surgery, we showed benefits to the laparoscopic donor to be less postoperative pain, better cosmesis, shorter recovery time, and faster return to normal activities. We therefore consider laparoscopic nephrectomy a good alternative to traditional surgery for selected patients. Despite a lack of strong evidence, such as large prospective randomized studies, laparoscopic donor nephrectomy is likely to become the gold standard for donor nephrectomy in the near future.

Surgical Complications are the Main Cause of Pancreatic Allograft Loss in Pancreas-Kidney Transplant Recipients

We examined surgical complications among a group of diabetic type 1 patients (IDDM) with end-stage renal disease (ESRD) who had undergone pancreas-kidney transplantations (PK). Between October 1993 and August 2004, 70 SPK were performed using bladder (n = 14) or enteric (n = 56) drainage. Donors were selected according to standard criteria (mean age, 27.6 years; range, 17-49). All patients received cyclosporine-based immunosuppression. All pancreata functioned immediately, whereas 2 patients needed postoperative dialysis. Four patients (5.7%) lost their pancreatic graft due to vascular thrombosis; both patients underwent urgent allograft pancreaectomy and pancreas retransplantation (re-PT). One of them (1.4%) experienced a venous thrombosis and died due to a pulmonary embolism at 12 hours after re-PT. The other 3 patients had uneventful postoperative courses and were discharged with good pancreatic and renal function. Three patients in the bladder group (21.4%) had an anastomotic leak, which resolved with a bladder catheter. Four patients in the enteric group (7.1%) who experienced an anastomotic leak needed a second surgical procedure but in 3 of them allograft pancreatectomy was necessary. Relaparotomy was required in the other 3 patients due to hemorrhage (1 patient) or occlusion (2 patients). Acute rejection episodes, which occurred in 16 patients (22.8%), were treated with steroid boluses. With a mean follow-up of 72 months (range, 3-129), 2 patients have died at 8 and at 36 months, respectively, after SPK due to acute myocardial infarction (2.9%). Chronic rejection was the leading cause of pancreatic failure in 5 patients (7.1%) and of renal failure in 2 patients (2.8%). Patient, kidney, and pancreas survival rates were 95.8%, 92.9%, and 81.5%, respectively. Surgical complications were the leading cause of pancreatic allograft loss in IDDM and ESRD patients submitted to SPK.