Characterization of dermal myofibroblast differentiation in pseudoxanthoma elasticum

Faust, Isabel; Donhauser, Elfi; Fischer, Bastian; Ibold, Bettina; Kühn, Joachim; Knabbe, Cornelius; Hendig, Doris

doi:10.1016/j.yexcr.2017.09.001

Cited by 12 publications

(11 citation statements)

References 70 publications

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“…We found that activin A-mediated XYLT1 mRNA expression increase is time-and concentration-dependent, and considerably increased the intra-and extracellular XT enzyme activity in NHDF. The correlation of mRNA expression and enzyme activity increase regarding XT-I has been shown in this and numerous other studies using TGFβ1-treated human dermal and cardiac fibroblasts [26,27,[45][46][47]. Furthermore, we observed, in consistency with previous results in NHDF [25], that the extracellular enzyme activity of untreated cells increased over time due to the protein accumulation in the cell supernatant, while intracellular XT activity remains constant over the test period of 120 h. These findings support the hypothesis that two regulatory mechanisms exist to control enzyme activity in NHDF: One at the transcriptional stage and another operating post-translationally, shedding the Golgi-resident, constitutive active enzyme from the membrane for release to the extracellular space controlling the rate of PG biosynthesis by reducing the cellular enzyme amount [24,29].…”

Section: Discussionsupporting

confidence: 75%

“…Many TGFβ superfamily ligands are potent mediators of ECM deposition and are highly up-regulated under fibrotic conditions [42]. Until now, studies have described an induction of XYLT1 expression in fibrotic tissue or in cultured primary cells treated with TGFβ1, IL-1β or thrombin [26,27,[43][44][45][46][47], while the effect of other pro-fibrotic cytokines and their underlying signalling pathways remain unknown.…”

Section: Discussionmentioning

confidence: 99%

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Activin A-Mediated Regulation of XT-I in Human Skin Fibroblasts

Plümers

Fischer

et al. 2020

Biomolecules

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Fibrosis is a fundamental feature of systemic sclerosis (SSc) and is characterized by excessive accumulation of extracellular matrix components like proteoglycans (PG) or collagens in skin and internal organs. Serum analysis from SSc patients showed an increase in the enzyme activity of xylosyltransferase (XT), the initial enzyme in PG biosynthesis. There are two distinct XT isoforms—XT-I and XT-II—in humans, but until now only XT-I is associated with fibrotic remodelling for an unknown reason. The aim of this study was to identify new XT mediators and clarify the underlying mechanisms, in view of developing putative therapeutic anti-fibrotic interventions in the future. Therefore, we used different cytokines and growth factors, small molecule inhibitors as well as small interfering RNAs, and assessed the cellular XT activity and XYLT1 expression in primary human dermal fibroblasts by radiochemical activity assays and qRT-PCR. We identified a new function of activin A as a regulator of XYLT1 mRNA expression and XT activity. While the activin A-induced XT-I increase was found to be mediated by activin A receptor type 1B, MAPK and Smad pathways, the activin A treatment did not alter the XYLT2 expression. Furthermore, we observed a reciprocal regulation of XYLT1 and XYLT2 transcription after inhibition of the activin A pathway components. These results improve the understanding of the differential expression regulation of XYLT isoforms under pathological fibroproliferative conditions.

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Section: Discussionsupporting

confidence: 75%

Section: Discussionmentioning

confidence: 99%

Activin A-Mediated Regulation of XT-I in Human Skin Fibroblasts

Plümers

Fischer

et al. 2020

Biomolecules

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“…MMP2 and MMP9 are thought to play a role in PXE, due to evidence of an increase in their serum levels in PXE patients 28 . From a cellular perspective, only differential expression of MMP2 could be demonstrated in PXE-fibroblasts 29,30 . In the present study, we found higher levels of Mmp2 and Timp1 expression in the TA of Abcc6 −/− DOCA compared to untreated Abcc6 −/− mice, likely indicative of ongoing ECM remodelling and increased collagen turnover in hypertensive Abcc6 −/− mice 29 .…”

Section: Discussionmentioning

confidence: 99%

Evidence of Cardiovascular Calcification and Fibrosis in Pseudoxanthoma Elasticum Mouse Models Subjected to DOCA-Salt Hypertension

Omarjee

Roy

Lebœuf

et al. 2019

Sci Rep

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Pseudoxanthoma Elasticum (PXE) is a rare disorder characterized by fragmentation and progressive calcification of elastic fibres in connective tissues. Although arterial hypertension (AHT) has been reported in PXE patients, its impact on pathological manifestations has as yet been unexplored. We investigated the consequences of experimental AHT on Abcc6−/− PXE mouse models. Experimental AHT was induced by deoxycorticosterone acetate (DOCA-salt) in uni-nephrectomised mice. Blood pressure (BP) and vascular reactivity were monitored using tail-cuff plethysmography and myography respectively. Calcium content and fibrosis were assessed using colorimetry, Von Kossa and Sirius red staining respectively. The gene expression implicated in vascular biology was measured using quantitative polymerase chain reaction. DOCA-salt induced a matching rise in BP in Abcc6−/− and WT mice. Aortic ring contraction and relaxation in vitro were comparable. Calcium accumulated in the hearts of hypertensive Abcc6−/− mice along with significant fibrosis in the myocardium and aorta by contrast with the WT mice. In hypertensive Abcc6−/− mouse aortas, these results were corroborated by gene expression patterns favouring calcification, fibrosis and extracellular matrix remodelling. Abcc6 loss-of-function is associated with greater cardiovascular calcification and fibrosis in mice subjected to DOCA-Salt hypertension. These results suggest likely cardiovascular deterioration in PXE patients with AHT, necessitating diligent BP monitoring.

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“…Relative quantification of mRNA expression levels with SYBR green-based real-time PCR was carried out, as has been described previously 59 . Briefly, 1 µg RNA was reverse transcribed to cDNA using the SuperScript II Reverse Transcriptase Kit (Thermo Fisher, San Diego, USA).…”

Section: Methodsmentioning

confidence: 99%

microRNA-29b mediates fibrotic induction of human xylosyltransferase-I in human dermal fibroblasts via the Sp1 pathway

Riedel

Fischer

et al. 2018

Sci Rep

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Diminished microRNA-29b levels have recently been revealed to provoke increased expression and accumulation of extracellular matrix molecules, such as collagens in fibrotic remodeling. Subsequently, the aim of this study was to find out whether microRNA-29b might also regulate human xylosyltransferase (XT)-I expression. XT-I has been characterized previously as a fibrosis biomarker catalyzing the key step of proteoglycan biosynthesis. While we demonstrate that XYLT1 is neither a target of microRNA-29b identified in silico nor a direct 3′ untranslated region binding partner of microRNA-29b, transfection of normal human dermal fibroblasts with microRNA-29b inhibitor strongly increased XYLT1 mRNA expression and XT activity. Combined results of the target prediction analysis and additional transfection experiments pointed out that microRNA-29b exerts indirect influence on XT-I by targeting the transcription factor specificity protein 1 (Sp1). We could confirm our hypothesis due to the decrease in XYLT1 promoter activity after Sp1 binding site mutation and the approval of occupancy of these binding sites by Sp1 in vitro. Taken together, a hitherto unidentified pathway of XT-I regulation via microRNA-29b/Sp1 was determined in this study. Our observations will facilitate the understanding of complex molecular fibrotic pathways and provide new opportunities to investigate microRNA-based antifibrotic tools.

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Characterization of dermal myofibroblast differentiation in pseudoxanthoma elasticum

Cited by 12 publications

References 70 publications

Activin A-Mediated Regulation of XT-I in Human Skin Fibroblasts

Activin A-Mediated Regulation of XT-I in Human Skin Fibroblasts

Evidence of Cardiovascular Calcification and Fibrosis in Pseudoxanthoma Elasticum Mouse Models Subjected to DOCA-Salt Hypertension

microRNA-29b mediates fibrotic induction of human xylosyltransferase-I in human dermal fibroblasts via the Sp1 pathway

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