scholarly journals The Role of PPAR Gamma in Systemic Sclerosis

PPAR Research ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Andréa Tavares Dantas ◽  
Michelly Cristiny Pereira ◽  
Moacyr Jesus Barreto de Melo Rego ◽  
Laurindo Ferreira da Rocha ◽  
Ivan da Rocha Pitta ◽  
...  

Fibrosis is recognized as an important feature of many chronic diseases, such as systemic sclerosis (SSc), an autoimmune disease of unknown etiology, characterized by immune dysregulation and vascular injury, followed by progressive fibrosis affecting the skin and multiple internal organs. SSc has a poor prognosis because no therapy has been shown to reverse or arrest the progression of fibrosis, representing a major unmet medical need. Recently, antifibrotic effects of PPARγligands have been studiedin vitroandin vivoand some theories have emerged leading to new insights. Aberrant PPARγfunction seems to be implicated in pathological fibrosis in the skin and lungs. This antifibrotic effect is mainly related to the inhibition of TGF-β/Smad signal transduction but other pathways can be involved. This review focused on recent studies that identified PPARγas an important novel pathway with critical roles in regulating connective tissue homeostasis, with emphasis on skin and lung fibrosis and its role on systemic sclerosis.

2020 ◽  
Vol 21 (14) ◽  
pp. 5102
Author(s):  
Roberto Lande ◽  
Anna Mennella ◽  
Raffaella Palazzo ◽  
Immacolata Pietraforte ◽  
Katia Stefanantoni ◽  
...  

Systemic sclerosis (SSc) is characterized by skin/internal organ fibrosis, vasculopathy and autoimmunity. Chemokine (C-X-C motif) ligand 4 (CXCL4) is an SSc biomarker, predicting unfavorable prognosis and lung fibrosis. CXCL4 binds DNA/RNA and favors interferon (IFN)-α production by plasmacytoid dendritic cells (pDCs), contributing to the type I IFN (IFN-I) signature in SSc patients. However, whether CXCL4 is an autoantigen in SSc is unknown. Here, we show that at least half of SSc patients show consistent antibody reactivity to CXCL4. T-cell proliferation to CXCL4, tested in a limited number of patients, correlates with anti-CXCL4 antibody reactivity. Antibodies to CXCL4 mostly correlate with circulating IFN-α levels and are significantly higher in patients with lung fibrosis in two independent SSc cohorts. Antibodies to CXCL4 implement the CXCL4–DNA complex’s effect on IFN-α production by pDCs; CXCL4–DNA/RNA complexes stimulate purified human B-cells to become antibody-secreting plasma cells in vitro. These data indicate that CXCL4 is indeed an autoantigen in SSc and suggest that CXCL4, and CXCL4-specific autoantibodies, can fuel a harmful loop: CXCL4–DNA/RNA complexes induce IFN-α in pDCs and direct B-cell stimulation, including the secretion of anti-CXCL4 antibodies. Anti-CXCL4 antibodies may further increase pDC stimulation and IFN-α release in vivo, creating a vicious cycle which sustains the SSc IFN-I signature and general inflammation.


2021 ◽  
Vol 22 (15) ◽  
pp. 7838
Author(s):  
Paola Arboretto ◽  
Michele Cillo ◽  
Antonio Leonardi

The transforming growth factor beta (TGF-β) signaling is fundamental for correct embryonic development. However, alterations of this pathway have been correlated with oncogenesis, tumor progression and sustaining of cancer stem cells (CSCs). Cripto-1 (CR-1) and Nodal are two embryonic proteins involved in TGF-β signaling. Their expression is almost undetectable in terminally differentiated cells, but they are often re-expressed in tumor cells, especially in CSCs. Moreover, cancer cells that show high levels of CR-1 and/or Nodal display more aggressive phenotypes in vitro, while in vivo their expression correlates with a worse prognosis in several human cancers. The ability to target CSCs still represents an unmet medical need for the complete eradication of certain types of tumors. Given the prognostic role and the selective expression of CR-1 and Nodal on cancer cells, they represent archetypes for targeted therapy. The aim of this review is to clarify the role of CR-1 and Nodal in cancer stem populations and to summarize the current therapeutic strategy to target CSCs using monoclonal antibodies (mAbs) or other molecular tools to interfere with these two proteins.


2013 ◽  
Vol 82 (2) ◽  
pp. 731-744 ◽  
Author(s):  
David Pajuelo ◽  
Chung-Te Lee ◽  
Francisco J. Roig ◽  
Manuel L. Lemos ◽  
Lien-I Hor ◽  
...  

ABSTRACTThe zoonotic serovar ofVibrio vulnificus(known as biotype 2 serovar E) is the etiological agent of human and fish vibriosis. The aim of the present work was to discover the role of the vulnibactin- and hemin-dependent iron acquisition systems in the pathogenicity of this zoonotic serovar under the hypothesis that both are host-nonspecific virulence factors. To this end, we selected three genes for three outer membrane receptors (vuuA, a receptor for ferric vulnibactin, andhupAandhutR, two hemin receptors), obtained single and multiple mutants as well as complemented strains, and tested them in a series ofin vitroandin vivoassays, using eels and mice as animal models. The overall results confirm thathupAandvuuA, but nothutR, are host-nonspecific virulence genes and suggest that a third undescribed host-specific plasmid-encoded system could also be used by the zoonotic serovar in fish.hupAandvuuAwere expressed in the internal organs of the animals in the first 24 h of infection, suggesting that they may be needed to achieve the population size required to trigger fatal septicemia.vuuAandhupAwere sequenced in strains representative of the genetic diversity of this species, and their phylogenies were reconstructed by multilocus sequence analysis of selected housekeeping and virulence genes as a reference. Given the overall results, we suggest that both genes might form part of the core genes essential not only for disease development but also for the survival of this species in its natural reservoir, the aquatic environment.


2019 ◽  
Vol 8 (1) ◽  
pp. 39
Author(s):  
Elisabetta Caselli ◽  
Irene Soffritti ◽  
Maria D’Accolti ◽  
Daria Bortolotti ◽  
Roberta Rizzo ◽  
...  

Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, excessive extracellular matrix deposition, and fibrosis of the skin and internal organs. Several infectious agents, including human herpesvirus-6 (HHV-6), have been suggested as possible triggering factors, but a direct association is still missing. We characterized 26 SSc patients for the presence of HHV-6 in tissues and blood, the anti-HHV-6 response, HLA-G plasma levels, and KIR typing. Given the prominent role of endothelial cells (EC) in SSc pathogenesis, along with HHV-6 tropism for EC, we also investigated the expression of pro-fibrosis factors in HHV-6 infected EC. Results showed the presence of HHV-6A in skin biopsies, and an increased virus load was associated with disease severity and poor natural killer (NK) response against the virus, particularly in subjects exhibiting a KIR2 phenotype. HLA-G plasma levels were significantly higher in HHV-6A/B-KIR2 positive SSc patients and in vitro HHV-6A infection-induced pro-fibrosis factors expression in EC, supporting its role in the development of the fibrosing process. Our data suggest an association between virus infection/reactivation and disease, opening the way to future studies to understand the mechanisms by which HHV-6A might contribute to the multifactorial pathogenesis of SSc.


2020 ◽  
Vol 8 (10) ◽  
pp. 1531
Author(s):  
Ina Kelava ◽  
Mirna Mihelčić ◽  
Mateja Ožanič ◽  
Valentina Marečić ◽  
Maša Knežević ◽  
...  

Francisella tularensis is a highly virulent intracellular pathogen that proliferates within various cell types and can infect a multitude of animal species. Francisella escapes the phagosome rapidly after infection and reaches the host cell cytosol where bacteria undergo extensive replication. Once cytosolic, Francisella becomes a target of an autophagy-mediated process. The mechanisms by which autophagy plays a role in replication of this cytosolic pathogen have not been fully elucidated. In vitro, F. tularensis avoids degradation via autophagy and the autophagy process provides nutrients that support its intracellular replication, but the role of autophagy in vivo is unknown. Here, we investigated the role of autophagy in the pathogenesis of tularemia by using transgenic mice deficient in Atg5 in the myeloid lineage. The infection of Atg5-deficient mice with Francisella tularensis subsp. holarctica live vaccine strain (LVS) resulted in increased survival, significantly reduced bacterial burden in the mouse organs, and less severe histopathological changes in the spleen, liver and lung tissues. The data highlight the contribution of Atg5 in the pathogenesis of tularemia in vivo.


2018 ◽  
Vol 2 (S1) ◽  
pp. 32-33
Author(s):  
Xinh-Xinh Nguyen ◽  
Tetsuya Nishimoto ◽  
Takahisa Takihara ◽  
Logan Mlakar ◽  
Ellen Riemer ◽  
...  

OBJECTIVES/SPECIFIC AIMS: Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology characterized by progressive fibrosis of the skin and multiple visceral organs. Effective therapies for SSc are needed. Lysyl oxidase (LOX) is a copper-dependent amide oxidase that plays a critical role in the crosslinking of the extracellular matrix (ECM). In this study, we investigated the role of LOX in the pathophysiology of SSc. METHODS/STUDY POPULATION: LOX expression and protein levels were measured in lung tissues and primary fibroblasts from patients with SSc and healthy controls. The effects of recombinant LOX (rLOX) were measured in vitro in primary fibroblasts, ex vivo in human lung tissues and in vivo in mice given bleomycin in combination with rLOX. LOX levels and activity were evaluated in lung fibroblasts treated with an endostatin-derived peptide that ameliorates fibrosis and in mice treated with bleomycin in combination with the peptide. Further, to differentiate the crosslinking activity of LOX from other potential effects, primary human fibroblasts were cultured with rLOX in the presence of the inhibitor, beta-aminopropionitrile. The expression levels of ECM (collagen and fibronectin), pro-fibrotic factors (IL-6 and TGF-beta), and transcription factor (c-Fos) were examined by real-time PCR, ELISA, immunoblotting, or hydroxyproline assay. RESULTS/ANTICIPATED RESULTS: LOX mRNA was increased in lung tissues and matching fibroblasts of SSc patients. rLOX-induced ECM production in vitro and ex vivo in lung fibroblasts and in human lung tissues maintained in organ culture, respectively. Additionally, TGF-beta and bleomycin induced ECM production, LOX mRNA expression and activity. Endostatin peptide abrogated these effects. In vivo, rLOX synergistically exacerbated pulmonary fibrosis in bleomycin-treated mice. The inhibition of LOX catalytic activity by beta-aminopropionitrile failed to abrogate LOX-induced ECM production. LOX increased the production of IL-6. IL-6 neutralization blocked the effects of LOX. Further, LOX induced c-Fos expression and its nuclear localization. DISCUSSION/SIGNIFICANCE OF IMPACT: LOX expression and activity were increased with fibrosis in vitro, ex vivo, and in vivo. LOX induced fibrosis via increasing ECM, IL-6 and c-Fos translocation to the nucleus. These effects were independent of the crosslinking activity of LOX and mediated by IL-6. Our findings suggest that inhibition of LOX may be a viable option for the treatment of lung fibrosis. Further, the use of human lung in organ culture establishes the relevance of our findings to human disease.


2001 ◽  
Vol 280 (6) ◽  
pp. L1327-L1334 ◽  
Author(s):  
Martin Kolb ◽  
Peter J. Margetts ◽  
Patricia J. Sime ◽  
Jack Gauldie

Transforming growth factor (TGF)-β is a key cytokine in the pathogenesis of pulmonary fibrosis, and pharmacological interference with TGF-β can ameliorate the fibrotic tissue response. The small proteoglycans decorin and biglycan are able to bind and inhibit TGF-β activity in vitro. Although decorin has anti-TGF-β properties in vivo, little is known about the physiological role of biglycan in vivo. Adenoviral gene transfer was used to overexpress active TGF-β, decorin, and biglycan in cell culture and in murine lungs. Both proteoglycans were able to interfere with TGF-β bioactivity in vitro in a dose-dependant manner. In vivo, overexpression of TGF-β resulted in marked lung fibrosis, which was significantly reduced by concomitant overexpression of decorin. Biglycan, however, had no significant effect on lung fibrosis induced by TGF-β. The data suggest that differences in tissue distribution are responsible for the different effects on TGF-β bioactivity in vivo, indicating that decorin, but not biglycan, has potential therapeutic value in fibrotic disorders of the lung.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.


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