Abstract 14664: Reduced Activin Like Kinase 1 Activity Promotes Cardiac Fibrosis in Heart Failure

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Kevin Morine ◽  
Vikram Paruchuri ◽  
Xiaoying Qiao ◽  
Emily Mackey ◽  
Mark Aronovitz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Remodeling ◽  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Left Ventricular ◽  
Lv Function ◽  
Type I ◽  
Mrna Levels ◽  
Protein Levels

Introduction: Activin receptor like kinase 1 (ALK1) mediates signaling via transforming growth factor beta-1 (TGFb1), a pro-fibrogenic cytokine. No studies have defined a role for ALK1 in heart failure. We tested the hypothesis that reduced ALK1 expression promotes maladaptive cardiac remodeling in heart failure. Methods and Results: ALK1 mRNA expression was quantified by RT-PCR in left ventricular (LV) tissue from patients with end-stage heart failure and compared to control LV tissue obtained from the National Disease Research Interchange (n=8/group). Compared to controls, LV ALK1 mRNA levels were reduced by 85% in patients with heart failure. Next, using an siRNA approach, we tested whether reduced ALK1 levels promote TGFb1-mediated collagen production in human cardiac fibroblasts. Treatment with an ALK1 siRNA reduced ALK1 mRNA levels by 75%. Compared to control, TGFb1-mediated Type I collagen and pSmad-3 protein levels were 2.5-fold and 1.7-fold higher, respectively, after ALK1 depletion. To explore a role for ALK1 in heart failure, ALK1 haploinsufficient (ALK1) and wild-type mice (WT; n=8/group) were studied 2 weeks after thoracic aortic constriction (TAC). Compared to WT, baseline LV ALK1 mRNA levels were 50% lower in ALK1 mice. Both LV and lung weights were higher in ALK1 mice after TAC. Cardiomyocyte area and LV mRNA levels of BNP, RCAN, and b-MHC were increased similarly, while SERCa levels were reduced in both ALK1 and WT mice after TAC. Compared to WT, LV fibrosis (Figure) and Type 1 Collagen mRNA and protein levels were higher among ALK1 mice. Compared to WT, LV fractional shortening (48±12 vs 26±10%, p=0.01) and survival (Figure) were lower in ALK1 mice after TAC. Conclusions: Reduced LV expression of ALK1 is associated with advanced heart failure in humans and promotes early mortality, impaired LV function, and cardiac fibrosis in a murine model of heart failure. Further studies examining the role of ALK1 and ALK1 inhibitors on cardiac remodeling are required.

Abstract 64: Conditional Knockout of Activin Like Kinase-1 (ALK-1) Leads to Heart Failure Without Maladaptive Remodeling

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Kevin Morine ◽  
Vikram Paruchuri ◽  
Xiaoying Qiao ◽  
Emily Mackey ◽  
Jonathan Levine ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Remodeling ◽  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Conditional Knockout ◽  
Type I ◽  
Total Body Mass

Activin like kinase 1 (ALK1) mediates signaling via the TGFb family of ligands. ALK1 activity promotes endothelial proliferation and migration. Reduced ALK1 activity is associated with arteriovenous malformations. No studies have examined the effect of global ALK1 deletion on indices of cardiac remodeling. We hypothesized that reduced levels of ALK1 promote maladaptive cardiac remodeling. Methods: We employed an ALK1 conditional knockout mice (cKO) harboring the ROSA26-CreER knock-in allele whereby a single dose of intraperitoneal tamoxifen triggered ubiquitous Cre recombinase mediated excision of floxed ALK1 alleles. Tamoxifen treated wild-type (WT-Tam; n=5) and vehicle treated ALK1-cKO mice (cKO-Veh; n=5) served as controls for tamoxifen treated ALK1-cKO mice (cKO-Tam; n=15). Results: ALK1 cKO-Tam mice demonstrated reduced 14-day survival compared to cKO-Veh controls (33% vs 100%, respectively, p<0.01). Seven days after treatment, ALK1 cKO mice began to exhibit reduced left ventricular (LV) fractional shortening, progressive LV dilation, and gastrointestinal bleeding. After 14 days total body mass was reduced, but LV and lung mass increased in cKO-Tam not cKO-Veh mice. Peak LV systolic pressure, contractility, and arterial elastance were reduced, but LV end-diastolic pressure and stroke volume increased in cKO-Tam, not cKO-Veh mice. LV ALK1 mRNA and protein levels were reduced in cKO-Tam, not cKO-Veh mice. LV levels of other TGFb-family ligands and receptors (ALK5, TBRII, BMPRII, Endoglin, BMP7, BMP9, and TGFB1) were unchanged between groups. Cardiomyocyte area and LV levels of BNP were increased in cKO-Tam mice, but LV levels of b-MHC, SerCA, and calcineurin were unchanged. No increase in cardiac fibrosis Type I collagen, CTGF, or PAI-1 levels were observed between groups. No differences were observed for any variable studied between cKO-Veh and WT-Tam mice. Conclusion: Global deletion of ALK1 is associated with the development of high output heart failure without maladaptive remodeling. Future studies exploring the functional role of ALK1 in cardiac remodeling are required.

scholarly journals The AP-1 Transcription Factor Fosl-2 Regulates Autophagy in Cardiac Fibroblasts during Myocardial Fibrogenesis

2021 ◽  
Vol 22 (4) ◽  
pp. 1861
Author(s):  
Jemima Seidenberg ◽  
Mara Stellato ◽  
Amela Hukara ◽  
Burkhard Ludewig ◽  
Karin Klingel ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Smooth Muscle Actin ◽  
Beclin 1 ◽  
Type I ◽  
Alpha Smooth Muscle Actin

Background: Pathological activation of cardiac fibroblasts is a key step in development and progression of cardiac fibrosis and heart failure. This process has been associated with enhanced autophagocytosis, but molecular mechanisms remain largely unknown. Methods and Results: Immunohistochemical analysis of endomyocardial biopsies showed increased activation of autophagy in fibrotic hearts of patients with inflammatory cardiomyopathy. In vitro experiments using mouse and human cardiac fibroblasts confirmed that blockade of autophagy with Bafilomycin A1 inhibited fibroblast-to-myofibroblast transition induced by transforming growth factor (TGF)-β. Next, we observed that cardiac fibroblasts obtained from mice overexpressing transcription factor Fos-related antigen 2 (Fosl-2tg) expressed elevated protein levels of autophagy markers: the lipid modified form of microtubule-associated protein 1A/1B-light chain 3B (LC3BII), Beclin-1 and autophagy related 5 (Atg5). In complementary experiments, silencing of Fosl-2 with antisense GapmeR oligonucleotides suppressed production of type I collagen, myofibroblast marker alpha smooth muscle actin and autophagy marker Beclin-1 in cardiac fibroblasts. On the other hand, silencing of either LC3B or Beclin-1 reduced Fosl-2 levels in TGF-β-activated, but not in unstimulated cells. Using a cardiac hypertrophy model induced by continuous infusion of angiotensin II with osmotic minipumps, we confirmed that mice lacking either Fosl-2 (Ccl19CreFosl2flox/flox) or Atg5 (Ccl19CreAtg5flox/flox) in stromal cells were protected from cardiac fibrosis. Conclusion: Our findings demonstrate that Fosl-2 regulates autophagocytosis and the TGF-β-Fosl-2-autophagy axis controls differentiation of cardiac fibroblasts. These data provide a new insight for the development of pharmaceutical targets in cardiac fibrosis.

Abstract P410: A Novel Curcumin Formulation, ASD-cur Suppressed Heart Failure After Myocardial Infarction In Rats

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Hidemichi Takai ◽  
Tatsuya Morimoto
Keyword(s):  
Heart Failure ◽  
Plasma Concentration ◽  
Cardiac Fibrosis ◽  
Myocardial Cell ◽  
Left Ventricular ◽  
Cell Diameter ◽  
Maximum Plasma ◽  
Mrna Levels ◽  
Time Curve ◽  
Sd Rats

Introduction: Curcumin prevents the development of heart failure and is a potential treatment for heart failure. Although curcumin is known to be safe, its therapeutic efficiency is limited due to its low bioavailability. To overcome this problem, we developed ASD-Cur, an amorphous formulation of curcumin. In this study, we investigated the effect of ASD-Cur and compared it with Theracurmin ® , a colloidal submicron dispersion of curcumin. Methods: Male SD rats were orally administrated with ASD-Cur or Theracurmin ® (10 mg/kg curcumin). The plasma levels of curcumin were measured at 0.25, 0.5, 1, 2, 4 and 6 hours after administration. Twelve healthy volunteers, who had provided written informed consent, were administrated with ASD-Cur and Theracurmin ® containing 30 mg curcumin, and plasma curcumin concentrations were determined at 0.5, 1, 2, 4, and 8 hours. Next, male SD rats were subjected to MI or sham surgery. One week after surgery, the MI rats were randomly assigned to 4 groups: vehicle, ASD-Cur (0.2 mg/kg curcumin) or Theracurmin ® (0.2 or 0.5 mg/kg curcumin). Oral administration of these compounds was repeated for 6 weeks. After echocardiographic examinations, myocardial cell diameter, perivascular fibrosis, mRNA levels, and the acetylation of histone H3K9 were measured. Results: After administration in rats, the area under the plasma concentration-time curve ( AUC 0-6h ) and the maximum plasma concentration ( C max ) of ASD-Cur were 3.7-fold and 9.6-fold higher than those of Theracurmin ® , respectively. The AUC 0-8h and C max of ASD-Cur in humans were 3.4-fold and 5.4-fold higher than those of Theracurmin ® , respectively. Echocardiographic analysis showed that 0.2 mg/kg ASD-Cur and 0.5 mg/kg Theracurmin ® significantly improved the MI-induced deterioration of FS and left ventricular hypertrophy to the same extent. Both treatments significantly suppressed MI-induced increases in myocardial cell diameter, perivascular fibrosis, mRNA levels of hypertrophic markers and cardiac fibrosis, and acetylation of histone H3K9 to the same extent. Conclusion: These findings indicated that ASD-Cur has greater bioavailability than Theracurmin ® , and could exhibit greater therapeutic potency towards for MI-induced heart failure at a lower dose.

scholarly journals MicroRNA-96 inhibits FoxO3a function in IPF fibroblasts on type I collagen matrix

2014 ◽  
Vol 307 (8) ◽  
pp. L632-L642 ◽  
Author(s):  
Richard Seonghun Nho ◽  
Jintaek Im ◽  
Yen-Yi Ho ◽  
Polla Hergert
Keyword(s):  
Type I Collagen ◽  
Collagen Matrix ◽  
Lung Fibroblasts ◽  
Normal Lung ◽  
Type I ◽  
Mrna Levels ◽  
Protein Levels ◽  
Dose Dependent Fashion ◽  
Mrna And Protein Expression

Idiopathic pulmonary fibrosis (IPF) is a lethal and progressive lung disease characterized by persistent (myo)fibroblasts and the relentless accumulation of collagen matrix. Unlike normal lung fibroblasts, IPF lung fibroblasts have suppressed forkhead box O3a (FoxO3a) activity, which allows them to expand in this diseased environment. microRNA-96 (miR-96) has recently been found to directly bind to the 3′-untranslated region of FoxO3a mRNA, which subsequently inhibits its function. We examined whether aberrantly low FoxO3a expression is in part due to increased miR-96 levels in IPF fibroblasts on polymerized collagen, thereby causing IPF fibroblasts to maintain their pathological properties. miR-96 expression was upregulated in IPF fibroblasts compared with control fibroblasts when cultured on collagen. In contrast, FoxO3a mRNA levels were reduced in most IPF fibroblasts. However, when miR-96 function was inhibited, FoxO3a mRNA and protein expression were increased, suppressing IPF fibroblast proliferation and promoting their cell death in a dose-dependent fashion. Likewise, FoxO3a and its target proteins p21, p27, and Bim expression was also increased in the presence of a miR-96 inhibitor in IPF fibroblasts. However, when control fibroblasts were treated with miR-96 mimic, FoxO3a, p27, p21, and Bim mRNA and protein levels were decreased. In situ hybridization analysis further revealed the presence of enhanced miR-96 expression in cells within the fibroblastic foci of IPF lung tissue. Our results suggest that when IPF fibroblasts interact with collagen-rich matrix, pathologically altered miR-96 expression inhibits FoxO3a function, causing IPF fibroblasts to maintain their pathological phenotype, which may contribute to the progression of IPF.

scholarly journals A Porcine Model of Heart Failure With Preserved Ejection Fraction Induced by Chronic Pressure Overload Characterized by Cardiac Fibrosis and Remodeling

2021 ◽  
Vol 8 ◽  
Author(s):  
Weijiang Tan ◽  
Xiang Li ◽  
Shuang Zheng ◽  
Xiaohui Li ◽  
Xiaoshen Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Heart Failure ◽  
Ejection Fraction ◽  
Cardiac Fibrosis ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Pathological Examination ◽  
Type I ◽  
Preserved Ejection Fraction

Heart failure is induced by multiple pathological mechanisms, and current therapies are ineffective against heart failure with preserved ejection fraction (HFpEF). As there are limited animal models of HFpEF, its underlying mechanisms have not yet been elucidated. Here, we employed the descending aortic constriction (DAC) technique to induce chronic pressure overload in the left ventricles of Tibetan minipigs for 12 weeks. Cardiac function, pathological and cellular changes, fibrotic signaling activation, and gene expression profiles were explored. The left ventricles developed concentric hypertrophy from weeks 4 to 6 and transition to dilation starting in week 10. Notably, the left ventricular ejection fraction was maintained at &gt;50% in the DAC group during the 12-week period. Pathological examination, biochemical analyses, and gene profile analysis revealed evidence of inflammation, fibrosis, cell death, and myofilament dephosphorylation in the myocardium of HFpEF model animals, together with gene expression shifts promoting cardiac remodeling and downregulating metabolic pathways. Furthermore, we noted the activation of several signaling proteins that impact cardiac fibrosis and remodeling, including transforming growth factor-β/SMAD family members 2/3, type I/III/V collagens, phosphatidylinositol 3-kinase, extracellular signal-regulated kinase, matrix metalloproteinases 2 and 9, tissue inhibitor of metalloproteinases 1 and 2, interleukins 6 and 1β, and inhibitor of κBα/nuclear factor-κB. Our findings demonstrate that this chronic pressure overload-induced porcine HFpEF model is a powerful tool to elucidate the mechanisms of this disease and translate preclinical findings.

scholarly journals Potential therapeutic effect of thymoquinone and/or bee pollen on fluvastatin-induced hepatitis in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amro E. Mohamed ◽  
Mohammed A. El-Magd ◽  
Karim S. El-Said ◽  
Mohamed El-Sharnouby ◽  
Ehab M. Tousson ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Therapeutic Potential ◽  
Combined Therapy ◽  
Individual Treatment ◽  
Type I ◽  
Mrna Levels ◽  
Gamma Glutamyl Transpeptidase ◽  
Bee Pollen

AbstractHepatitis is one of earlier, but serious, signs of liver damage. High doses of statins for a long time can induce hepatitis. This study aimed to evaluate and compare the therapeutic potential of thymoquinone (TQ) and bee pollen (BP) on fluvastatin (F)-induced hepatitis in rats. Rats were randomly divided into: group 1 (G1, control), G2 (F, hepatitis), G3 (F + TQ), G4 (F + BP), and G5 (F + TQ + BP). Single treatment with TQ or BP relieved fluvastatin-induced hepatitis, with best effect for the combined therapy. TQ and/or BP treatment significantly (1) reduced serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transpeptidase, and total bilirubin, (2) decreased malondialdehyde levels and increased level of reduced glutathione, and activities of glutathione peroxidase and catalase in the liver, (3) improved liver histology with mild deposition of type I collagen, (4) increased mRNA levels of transforming growth factor beta 1, nuclear factor Kappa B, and cyclooxygenase 1 and 2, and (5) decreased tumor necrosis factor alpha and upregulated interleukin 10 protein in the liver. These data clearly highlight the ability of TQ and BP combined therapy to cause better ameliorative effects on fluvastatin-induced hepatitis than individual treatment by each alone.

scholarly journals Uremic Toxins and Ciprofloxacin Affect Human Tenocytes In Vitro

2020 ◽  
Vol 21 (12) ◽  
pp. 4241
Author(s):  
Erman Popowski ◽  
Benjamin Kohl ◽  
Tobias Schneider ◽  
Joachim Jankowski ◽  
Gundula Schulze-Tanzil
Keyword(s):  
Type I Collagen ◽  
Uremic Toxins ◽  
Type I ◽  
Mrna Levels ◽  
Protein Levels ◽  
Cell Matrix ◽  
High Concentrations ◽  
High Doses ◽  
Very High

Tendinopathy is a rare but serious complication of quinolone therapy. Risk factors associated with quinolone-induced tendon disorders include chronic kidney disease accompanied by the accumulation of uremic toxins. Hence, the present study explored the effects of the representative uremic toxins phenylacetic acid (PAA) and quinolinic acid (QA), both alone and in combination with ciprofloxacin (CPX), on human tenocytes in vitro. Tenocytes incubated with uremic toxins +/- CPX were investigated for metabolic activity, vitality, expression of the dominant extracellular tendon matrix (ECM) protein type I collagen, cell-matrix receptor β1-integrin, proinflammatory interleukin (IL)-1β, and the ECM-degrading enzyme matrix metalloproteinase (MMP)-1. CPX, when administered at high concentrations (100 mM), suppressed tenocyte metabolism after 8 h exposure and at therapeutic concentrations after 72 h exposure. PAA reduced tenocyte metabolism only after 72 h exposure to very high doses and when combined with CPX. QA, when administered alone, led to scarcely any cytotoxic effect. Combinations of CPX with PAA or QA did not cause greater cytotoxicity than incubation with CPX alone. Gene expression of the pro-inflammatory cytokine IL-1β was reduced by CPX but up-regulated by PAA and QA. Protein levels of type I collagen decreased in response to high CPX doses, whereas PAA and QA did not affect its synthesis significantly. MMP-1 mRNA levels were increased by CPX. This effect became more pronounced in the form of a synergism following exposure to a combination of CPX and PAA. CPX was more tenotoxic than the uremic toxins PAA and QA, which showed only distinct suppressive effects.

Abstract 74: The Role of Fibroblast-specific Canonical Tgfβ Signaling in Cardiac Fibrosis

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Hadi Khalil ◽  
Onur Kanisicak ◽  
Robert N. Correll ◽  
Michelle Sargent ◽  
Jeffery D. Molkentin
Keyword(s):  
Heart Failure ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Interstitial Fibrosis ◽  
Contractile Activity ◽  
Cardiac Fibroblasts ◽  
Pressure Overload ◽  
Type I ◽  
Tgfβ Signaling ◽  
Chronic Heart Disease

Heart failure is a progressive disease characterized by cardiomyocyte loss, interstitial fibrosis, and chamber remodeling. During physiological conditions cardiac fibroblasts contribute to the homeostatic maintenance of myocardial structure as well as the maintenance of biochemical, mechanical and electrical properties of the heart. Injury and/or cytokine stimulation activate fibroblasts which transdifferentiate into myofibroblasts. These newly formed cells secrete extracellular matrix (ECM) for wound healing and tissue remodeling through their contractile activity. Fibrosis mediated by these cells can initially be a beneficial response that acutely scarifies areas after an infarct to prevent wall rupture. However, during chronic disease states such as heart failure, persistent recruitment and activation of fibroblasts leads to excessive deposition of ECM that results in stiffening and pathological remodeling of the ventricles. During chronic heart disease, cardiomyocytes, immune cells and fibroblasts secrete the cytokine transforming growth factor-TGFβ, which activates fibroblasts and promotes their conversion to myofibroblasts. Manipulation of TGFβ by losartan, which antagonizes angiotensin II (AngII) and aspects of TGFβ signaling, has shown some anti-fibrotic effects in cardiovascular remodeling. Also deletion of Tgfbr1 (type I TGFβ receptor) in cardiomyocytes or a TGFβ blocking antibody reduced the fibrotic response after pressure overload. However heart failure was not improved because deleterious TGFβ signaling in fibroblasts persisted. We therefore utilized a novel fibroblast-specific inducible Cre-expressing mouse line (Periostin-MerCreMer) to examine the canonical (Smad2/3) TGFβ signaling within fibroblasts to determine how these cells and their activation mediate disease in heart failure. Our data indicate that fibroblast-specific deletion of Smad3 but not Smad2 was sufficient to significantly inhibit myocardial fibrosis. Smad2/3 double nulls were also generated and analyzed, as were TGFBR1 and TGFBR2 loxp targeted mice, also crossed with the Postn-MerCreMer knockin allele to achieve specificity in activated fibroblasts.

Abstract 23: Immunosuppression with FTY720 Reverses Cardiac Dysfunction to Prevent Chronic Heart Failure in Mice that Survive Diet-induced Myocardial Infarction

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Fu Sang Luk ◽  
Roy Y Kim ◽  
Kang Li ◽  
Daniel Ching ◽  
Sunil Joshi ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Heart Failure ◽  
Chronic Heart Failure ◽  
Cardiac Dysfunction ◽  
Coronary Atherosclerosis ◽  
Left Ventricular ◽  
Lv Function ◽  
Chow Diet ◽  
Type I ◽  
Gene Repair

We recently reported that immunosuppression with FTY720 improves cardiac function and extends longevity in the HypoE/SR-BI-/- mouse model of diet-induced coronary atherosclerosis and myocardial infarction (MI). In this study we tested whether FTY720 could also reverse cardiac dysfunction in mice that survive MI and subsequently develop chronic heart failure (CHF). HypoE/SR-BI-/- mice were bred to Mx1-Cre mice and offspring were fed a high fat diet (HFD) for 21 days to provoke hyperlipidemia, coronary atherosclerosis and recurrent MIs. HypoE/SR-BI-/-Mx1-Cre mice were subsequently given oral FTY720 in drinking water or not. Hyperlipidemia was permanently reversed by inducible Cre-mediated gene repair of the HypoE allele (also known as the Apoeh/h allele) that rapidly restores normal apoE expression in all tissues and by switching mice to a normal chow diet. In cohorts of mice that survived this period of HFD, left ventricular (LV) function was monitored using serial echocardiography for up to 15 weeks. In untreated mice, LV performance progressively deteriorated. Although FTY720 treatment did not initially prevent a decline of heart function among HypoE/SR-BI-/-Mx1-Cre mice six weeks after Cre-mediated gene repair, it almost completely restored normal LV function in these mice by 15 weeks after cessation of HFD. Reversal of heart failure did not result from reduced atherosclerosis as the burden of both aortic and coronary atherosclerosis increased to similar levels in both groups of mice. Rather, FTY720 caused systemic immunosuppression as assessed by reduced numbers of circulating T and B lymphocytes. In the heart, FTY720 led to reduced expression of MMP-2 along with the expression of genes involved in Type I innate inflammation that we have recently demonstrated as major contributors to heart failure. Our data demonstrate the benefit of immunosuppression with FTY720 post MI to prevent progressive pathological remodeling of the heart, which leads to CHF.

scholarly journals Leukoregulin down-regulates type I collagen mRNA levels and promoter activity in human dermal fibroblasts, and counteracts the up-regulation elicited by transforming growth factor-β

1992 ◽  
Vol 284 (3) ◽  
pp. 629-632 ◽  
Author(s):  
A Mauviel ◽  
C H Evans ◽  
J Uitto
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Promoter Activity ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Dermal Fibroblasts ◽  
Type I ◽  
Mrna Levels ◽  
Human Dermal Fibroblasts

Leukoregulin (LR), a T-cell-derived growth factor, modulates fibroblast functions in vitro [Mauviel, Rédini, Hartmann, Loyau & Pujol (1991) J. Cell Biol. 113, 1455-1462]. In the present study, incubation of human dermal fibroblasts with LR (0.1-2 units/ml) resulted in decreases in the mRNA steady-state levels for alpha 1(I), alpha 2(I) and alpha 1(III), but not alpha 2(V), collagen genes. LR also down-regulated alpha 2(I) collagen promoter activity in transient cell transfections of control cells as well as those incubated with transforming growth factor-beta, a potent up-regulator of collagen type I gene expression. Thus LR is a strong inhibitor of type I collagen gene expression, acting at the level of transcription.

Sign in / Sign up

Export Citation Format

Share Document