Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist inhibits transforming growth factor-beta1 and matrix production in human dermal fibroblasts

2010 ◽  
Vol 63 (7) ◽  
pp. 1209-1216 ◽  
Author(s):  
Guo-You Zhang ◽  
Tao Cheng ◽  
Ming-Hua Zheng ◽  
Cheng-Gang Yi ◽  
Hua Pan ◽  
...  
2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jungon Yun ◽  
Changhee Kim ◽  
Mi-Bo Kim ◽  
Jae-Kwan Hwang

Photoaging occurs by UVB-irradiation and involves production of reactive oxygen species (ROS) and overexpression of matrix metalloproteinases (MMPs), leading to extracellular matrix damage.Piper retrofractumVahl. is used as a traditional medicine for antiflatulence, expectorant, sedative, and anti-irritant; however, its antiphotoaging effect has not yet been studied. The current study investigated the antiphotoaging effect of standardizedPiper retrofractumextract (PRE) on UVB-damaged human dermal fibroblasts and hairless mouse skin. PRE treatment activated the peroxisome proliferator-activated receptor delta (PPARδ) and the adenosine monophosphate-activated protein kinase (AMPK), consequently upregulating mitochondrial synthesis and reducing ROS production. Additionally, PRE inhibited MMPs expression via suppressing mitogen-activated protein kinase (MAPK) and activator protein-1 (AP-1). PRE downregulated UVB-induced inflammatory reactions by inhibiting the nuclear factor-kappa B (NF-κB) activity. PRE also enhanced transforming growth factor-beta (TGF-β) and the Smad signaling pathway, thereby promoting procollagen gene transcription. Furthermore, oral administration of PRE (300 mg/kg/day) similarly regulated the signaling pathways and increased antioxidant enzyme expression, thus attenuating physiological deformations, such as wrinkle formation and erythema response. Collectively, these results suggest that PRE acts as a potent antiphotoaging agent via PPARδand AMPK activation.


2007 ◽  
Vol 97 (06) ◽  
pp. 988-997 ◽  
Author(s):  
Mihail Hristov ◽  
Denis Gümbel ◽  
Teresa Tejerina ◽  
Santiago Redondo ◽  
Christian Weber

SummaryEndothelial progenitor cells (EPCs) have been implicated in vascular repair and found to be functionally impaired in patients with diabetes. We evaluated the effects of the anti-diabetic drug pioglitazone on human EPC function and the involvement of PPAR-γ and TGF-β1. EPCs in culture were characterized at day 7 by the development of colony-forming units (CFUs) and flow cytometry assessment of differentiation marker (DiI-ac-LDL/lectin, KDR and CD31). Adhesion on fibronectin and fibrinogen in flow was analyzed as functional parameter. Treatment with pioglitazone for 72 hours increased the number of EPC-CFUs, DiI-ac-LDL+/lectin+, CD31+ and KDR+ EPCs at 1 μM but not at 10 μM. Since pioglitazone did not significantly alter proliferation and apoptosis in cultured EPCs, the increase in EPC number was most likely attributable to augmented adhesion and differentiation. Indeed, pioglitazone increased EPC adhesion in flow at 1 μM, an effect prevented by PPAR-γ and β2-integrin blockade. In contrast, pioglitazone did not promote EPC adhesion at 10 μM; however, increased adhesion became evident by co-incubation with a blocking TGF-β1 antibody. As determined by ELISA, pioglitazone induced a persistent increase in TGF-β1 secretion only at 10 μM when a significantly elevated expression of endoglin, the accessory receptor forTGF-β1, was also observed. Taken together, pioglitazone exerts biphasic effects on the function of isolated EPCs, causing a PPAR-γ-dependent stimulation at 1 μM and a TGF-β1-mediated suppression at 10 μM. These results may help to define optimal therapeutic doses of pioglitazone for improving endothelial dysfunction.


1987 ◽  
Vol 247 (3) ◽  
pp. 597-604 ◽  
Author(s):  
J Varga ◽  
J Rosenbloom ◽  
S A Jimenez

It has been previously shown that transforming growth factor beta (TGF beta) is capable of stimulating fibroblast collagen and fibronectin biosynthesis. The purpose of this study was to examine the mechanisms involved in TGF beta stimulation of fibroblast biosynthetic activity. Our results indicate that TGF beta causes a marked enhancement of the production of types I and III collagens and fibronectin by cultured normal human dermal fibroblasts. The rate of collagen production by fibroblasts exposed to TGF beta was 2-3-fold greater than that of control cells. These effects were associated with a 2-3-fold increase in the steady-state amounts of types I and III collagen mRNAs and a 5-8-fold increase in the amounts of fibronectin mRNAs as determined by dot-blot hybridization with specific cloned cDNA probes. In addition, the increased production of collagen and fibronectin and the increased amounts of their corresponding mRNAs remained elevated for at least 72 h after removal of TGF beta. These findings suggest that TGF beta may play a major role in the normal regulation of extracellular matrix production in vivo and may contribute to the development of pathological states of fibrosis.


2017 ◽  
Vol 474 (9) ◽  
pp. 1531-1546 ◽  
Author(s):  
Sowmya P. Lakshmi ◽  
Aravind T. Reddy ◽  
Raju C. Reddy

Transforming growth factor β (TGF-β) contributes to wound healing and, when dysregulated, to pathological fibrosis. TGF-β and the anti-fibrotic nuclear hormone receptor peroxisome proliferator-activated receptor γ (PPARγ) repress each other's expression, and such PPARγ down-regulation is prominent in fibrosis and mediated, via previously unknown SMAD-signaling mechanisms. Here, we show that TGF-β induces the association of SMAD3 with both SMAD4, needed for translocation of the complex into the nucleus, and the essential context-sensitive co-repressors E2F4 and p107. The complex mediates TGF-β-induced repression by binding to regulatory elements in the target promoter. In the PPARG promoter, we found that the SMAD3–SMAD4 complex binds both to a previously unknown consensus TGF-β inhibitory element (TIE) and also to canonical SMAD-binding elements (SBEs). Furthermore, the TIE and SBEs independently mediated the partial repression of PPARG transcription, the first demonstration of a TIE and SBEs functioning within the same promoter. Also, TGF-β-treated fibroblasts contained SMAD complexes that activated a SMAD target gene in addition to those repressing PPARG transcription, the first finding of such dual activity within the same cell. These findings describe in detail novel mechanisms by which TGF-β represses PPARG transcription, thereby facilitating its own pro-fibrotic activity.


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