scholarly journals Long-Term Aspartame Administration Leads to Fibrosis, Inflammasome Activation, and Gluconeogenesis Impairment in the Liver of Mice

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 82
Author(s):  
Isabela A. Finamor ◽  
Caroline A. Bressan ◽  
Isabel Torres-Cuevas ◽  
Sergio Rius-Pérez ◽  
Marcelo da Veiga ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Liver Damage ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Elevated Serum ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Type I ◽  
Artificial Sweetener

Background: Aspartame is an artificial sweetener used in foods and beverages worldwide. However, it is linked to oxidative stress, inflammation, and liver damage through mechanisms that are not fully elucidated yet. This work aimed to investigate the effects of long-term administration of aspartame on the oxidative and inflammatory mechanisms associated with liver fibrosis progression in mice. Methods: Mice were divided into two groups with six animals each: control and aspartame. Aspartame (80 mg/kg, via oral) or vehicle was administrated for 12 weeks. Results: Aspartame caused liver damage and elevated serum transaminase levels. Aspartame also generated liver fibrosis, as evidenced by histology analysis, and pro-fibrotic markers’ upregulation, including transforming growth factor β 1, collagen type I alpha 1, and alpha-smooth muscle actin. Furthermore, aspartame reduced nuclear factor erythroid 2-related factor 2 (Nrf2) activation and enzymatic antioxidant activity and increased lipid peroxidation, which triggered NOD-like receptor containing protein 3 (NLRP3) inflammasome activation and p53 induction. Furthermore, aspartame reduced peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) levels, possibly through p53 activation. This PGC-1α deficiency could be responsible for the changes in lipid profile in serum, total lipid accumulation, and gluconeogenesis impairment in liver, evidenced by the gluconeogenic enzymes’ downregulation, thus causing hypoglycemia. Conclusions: This work provides new insights to understand the mechanisms related to the adverse effects of aspartame on liver tissue.

scholarly journals Hierarchical Coculture of Hepatocyte and Hepatic Non-Parenchymal Cells for Liver Fibrosis Studies in vitro

2020 ◽  
Author(s):  
Qiao You Lau ◽  
Fuad Gandhi Torizal ◽  
Marie Shinohara ◽  
Yasuyuki Sakai
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Oxygen Tension ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Liver Sinusoidal Endothelial Cell ◽  
Type I ◽  
Parenchymal Cells

During chronic liver injury, inflammation leads to the development of liver fibrosis— particularly due to the activation of hepatic stellate cells (HSCs). However, the involvement of inflammatory cytokines in HSC activation is unclear. Many existing in vitro liver models do not include these non-parenchymal cells (NPCs), and hence, do not represent the physiological relevance found in vivo. Herein, we demonstrated the hierarchical coculture of primary rat hepatocytes with NPCs such as the human-derived HSC line (LX-2) and the human-derived liver sinusoidal endothelial cell line (TMNK-1). The coculture tissue had higher albumin production and hepatic cytochrome P450 3A4 activity compared to the monoculture. We then further studied the effects of stimulation by both oxygen tension and key pro-fibrogenic cytokines, such as the transforming growth factor beta (TGF-β), on HSC activation. Gene expression analysis revealed that lower oxygen tension and TGF-β1 stimulation enhanced collagen type I, III, and IV, alpha-smooth muscle actin, platelet-derived growth factor, and matrix metallopeptidase expression from LX-2 cells in the hierarchical coculture after fibrogenesis induction. This hierarchical in vitro cocultured liver tissue could, therefore, provide an improved platform as a disease model for elucidating the interactions of various liver cell types and biochemical signals in liver fibrosis studies.

scholarly journals Therapeutic Effect of Dunaliella salina Microalgae on Thioacetamide- (TAA-) Induced Hepatic Liver Fibrosis in Rats: Role of TGF-β and MMP9

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Farouk K. El-Baz ◽  
Abeer Salama ◽  
Rania A. A. Salama
Keyword(s):  
Liver Fibrosis ◽  
Transforming Growth Factor Beta ◽  
Dunaliella Salina ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Elevated Serum ◽  
Serum Levels ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Liver Histopathology

Liver fibrosis represents a serious global health-care problem and is the outcome of many chronic liver diseases, cirrhosis, hepatitis, and toxin accumulation. The present study aimed to evaluate the antifibrotic curative effect of Dunaliella salina (D. salina) on thioacetamide- (TAA-) induced liver fibrosis in rats. Liver fibrosis was induced by TAA (200mg/kg; i.p.) twice per week for 6 weeks. D. salina was given orally (100 and 200 mg/kg) and silymarin was given orally (100 mg/kg) daily, for 4 weeks after TAA. Serum transaminase activities, liver inflammatory cytokines, fibrotic biomarkers, and liver histopathology were assessed. TAA significantly (p<0.05) elevated serum activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and serum levels of total bilirubin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and transforming growth factor-beta (TGF-β) with a reduction in albumin. In addition, TAA increased hepatic contents of collagen I, a-smooth muscle actin (α-SMA), and tissue inhibitors of metalloproteinase (TIMP-1), reduced matrix metalloproteinase 9 (MMP9), and finally produced marked degeneration and fibrosis of hepatocytes. Treatment with D. salina or silymarin improved the histological feature of hepatocytes and ameliorated the deleterious effects of TAA in a dose-dependent manner. Based on these results, it could be concluded that the use of D. salina could be assigned for liver fibrosis treatment via its anti-inflammatory and antifibrotic properties.

Cryptolepine derivative-6h inhibits liver fibrosis in TGF-β1-induced HSC-T6 cells by targeting the Shh pathway

2016 ◽  
Vol 94 (9) ◽  
pp. 987-995 ◽  
Author(s):  
Ying-Hua He ◽  
Zeng Li ◽  
Ming-Ming Ni ◽  
Xing-Yan Zhang ◽  
Ming-Fang Li ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Type I ◽  
African Countries ◽  
Shh Pathway ◽  
Tgf Β1

Liver fibrosis is a worldwide problem with a significant morbidity and mortality. Cryptolepis sanguinolenta (family Periplocaceae) is widely used in West African countries for the treatment of malaria, as well as for some other diseases. However, the role of C. sanguinolenta in hepatic fibrosis is still unknown. It has been reported that Methyl-CpG binding protein 2 (MeCP2) had a high expression in liver fibrosis and played a central role in its pathobiology. Interestingly, we found that a cryptolepine derivative (HZ-6h) could inhibit liver fibrosis by reducing MeCP2 expression, as evidenced by the dramatic downregulation of α-smooth muscle actin (α-SMA) and type I collagen alpha-1 (Col1α1) in protein levels in vitro. Meanwhile, we also found that HZ-6h could reduce the cell viability and promote apoptosis of hepatic stellate cells (HSCs) treated with transforming growth factor beta 1(TGF-β1). Then, we investigated the potential molecular mechanisms and found that HZ-6h blocked Shh signaling in HSC-T6 cells, resulting in the decreased protein expression of Patched-1 (PTCH-1), Sonic hedgehog (Shh), and glioma-associated oncogene homolog 1 (GLI1). In short, these results indicate that HZ-6h inhibits liver fibrosis by downregulating MeCP2 through the Shh pathway in TGF-β1-induced HSC-T6 cells.

scholarly journals Potential Ameliorative Effects of Qing Ye Dan Against Cadmium Induced Prostatic Deficits via Regulating Nrf-2/HO-1 and TGF-β1/Smad Pathways

2017 ◽  
Vol 43 (4) ◽  
pp. 1359-1368 ◽  
Author(s):  
Lifen Du ◽  
Yongfang Lei ◽  
Jinglou Chen ◽  
Hongping Song ◽  
Xinying Wu
Keyword(s):  
Oxidative Stress ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Smooth Muscle Actin ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Type I ◽  
Protective Effects ◽  
Mesenchymal Transition ◽  
Tgf Β1

Background/Aims: Cadmium (Cd) is an environmental pollutant with reproductive toxicity. Swertia mileensis is used in Chinese medicine for the treatment of prostatic deficits and named as Qing Ye Dan (QYD). This study was undertaken to investigate the potential protective effects of QYD against Cd-induced prostatic deficits. Method: Rat model of prostatic deficits was induced by 0.2 mg/kg/d CdCl2 subcutaneous injection for 15 days. The prostatic oxidative stress was evaluated by detecting the levels of malondialdehyde, nitric oxide, reduced/ oxidized glutathione, total sulfhydryl groups and enzymatic antioxidant status. The prostatic inflammation was estimated by testing the levels of pro-inflammatory cytokines. The levels of epithelial-mesenchymal transition (EMT) markers E-cadherin, fibronectin, vimentin and α-smooth muscle actin were measured by qPCR analysis. Additionally, the prostatic expressions of transforming growth factor-β1 (TGF-β1), type I TGF-β receptor (TGF-βRI), Smad2, phosphorylation-Smad2 (p-Smad2), Smad3, p-Smad3, Smad7, nuclear related factor-2 (Nrf-2), heme oxygenase-1 (HO-1), B-cell CLL/lymphoma (Bcl)-2 and Bcl-2-associated X protein (Bax) were measured by western blot assay. Results: It was found that QYD ameliorated the Cd-induced prostatic oxidative stress and inflammation, attenuated prostatic EMT, inhibited the TGF-β1/Smad pathway, increased Bcl-2/Bax ratio and enhanced the activity of Nrf-2/HO-1 pathway. Conclusion: These results showed that QYD could ameliorate Cd-induced prostatic deficits via modulating Nrf-2/HO-1 and TGF-β1/Smad pathways.

Gypenosides Ameliorate Carbon Tetrachloride-Induced Liver Fibrosis by Inhibiting the Differentiation of Hepatic Progenitor Cells into Myofibroblasts

2017 ◽  
Vol 45 (05) ◽  
pp. 1061-1074 ◽  
Author(s):  
Jiamei Chen ◽  
Xuewei Li ◽  
Yonghong Hu ◽  
Wei Liu ◽  
Qun Zhou ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Fibrosis ◽  
Progenitor Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Cytokeratin 19 ◽  
Type I ◽  
Alpha Smooth Muscle Actin

Gypenosides (GPs), the predominant components of Gynostemma pentaphyllum, exert antifibrotic effects; however, the mechanisms underlying their ability to ameliorate liver fibrosis are unclear. Liver fibrosis was induced in C57BL/6 mice via subcutaneous injection of 10% carbon tetrachloride (CCl[Formula: see text] three times a week for two weeks. Then, CCl4 was administered in conjunction with intragastric GPs for another three weeks. For in vitro analyses, WB-F344, hepatatic progenitor cells (HPCs) were treated with transforming growth factor beta 1 (TGF-[Formula: see text]1) with or without GPs for 48[Formula: see text]h. The results showed that alanine aminotransferase (ALT) and aspartate transaminase (AST) activity, deposition of collagen, hydroxyproline content, and expression of alpha-smooth muscle actin ([Formula: see text]-SMA) and collagen type I (Col I) were significantly decreased after treatment with GPs ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]). In the 5M CCl4 group, the expression of HPC markers, Sox9 and cytokeratin 19 (CK19), was significantly increased compared with the normal or GPs-treated group ([Formula: see text], [Formula: see text]). Immunostaining showed that the number of Sox9 and [Formula: see text]-SMA double-positive cells was higher in the 5M CCl4 group than in the normal group, but the addition of GPs caused this cell number to decrease. In WB-F344 cells, the expression of [Formula: see text]-SMA and Col I was significantly increased after treatment with TGF-[Formula: see text], whereas in the GPs treatment group, expression was markedly decreased ([Formula: see text]). The levels of TGF-[Formula: see text] and TGF-[Formula: see text]R1 were markedly reduced after GPs treatment both in vivo and in vitro. In conclusion, GPs ameliorated CCl4-induced liver fibrosis via the inhibition of TGF-[Formula: see text] signaling, consequently inhibiting the differentiation of HPCs into myofibroblasts.

scholarly journals Modulation of EndMT by Hydrogen Sulfide in the Prevention of Cardiovascular Fibrosis

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 910
Author(s):  
Lara Testai ◽  
Vincenzo Brancaleone ◽  
Lorenzo Flori ◽  
Rosangela Montanaro ◽  
Vincenzo Calderone
Keyword(s):  
Hydrogen Sulfide ◽  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Type I ◽  
Vascular Endothelial ◽  
Independent Manner ◽  
Mesenchymal Transition ◽  
Adult Age ◽  
Cardiovascular Fibrosis

Endothelial mesenchymal transition (EndMT) has been described as a fundamental process during embryogenesis; however, it can occur also in adult age, underlying pathological events, including fibrosis. Indeed, during EndMT, the endothelial cells lose their specific markers, such as vascular endothelial cadherin (VE-cadherin), and acquire a mesenchymal phenotype, expressing specific products, such as α-smooth muscle actin (α-SMA) and type I collagen; moreover, the integrity of the endothelium is disrupted, and cells show a migratory, invasive and proliferative phenotype. Several stimuli can trigger this transition, but transforming growth factor (TGF-β1) is considered the most relevant. EndMT can proceed in a canonical smad-dependent or non-canonical smad-independent manner and ultimately regulate gene expression of pro-fibrotic machinery. These events lead to endothelial dysfunction and atherosclerosis at the vascular level as well as myocardial hypertrophy and fibrosis. Indeed, EndMT is the mechanism which promotes the progression of cardiovascular disorders following hypertension, diabetes, heart failure and also ageing. In this scenario, hydrogen sulfide (H2S) has been widely described for its preventive properties, but its role in EndMT is poorly investigated. This review is focused on the evaluation of the putative role of H2S in the EndMT process.

scholarly journals Targeting lncRNA H19/miR-29b/COL1A1 Axis Impedes Myofibroblast Activities of Precancerous Oral Submucous Fibrosis

2021 ◽  
Vol 22 (4) ◽  
pp. 2216
Author(s):  
Cheng-Chia Yu ◽  
Yi-Wen Liao ◽  
Pei-Ling Hsieh ◽  
Yu-Chao Chang
Keyword(s):  
Type I Collagen ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Oral Submucous Fibrosis ◽  
Ectopic Expression ◽  
Collagen Gel ◽  
Type I ◽  
Migration Ability ◽  
Potentially Malignant ◽  
Submucous Fibrosis

Oral submucous fibrosis (OSF) is known as a potentially malignant disorder, which may result from chemical irritation due to areca nuts (such as arecoline). Emerging evidence suggests that fibrogenesis and carcinogenesis are regulated by the interaction of long noncoding RNAs (lncRNAs) and microRNAs. Among these regulators, profibrotic lncRNA H19 has been found to be overexpressed in several fibrosis diseases. Here, we examined the expression of H19 in OSF specimens and its functional role in fibrotic buccal mucosal fibroblasts (fBMFs). Our results indicate that the aberrantly overexpressed H19 contributed to higher myofibroblast activities, such as collagen gel contractility and migration ability. We also demonstrated that H19 interacted with miR-29b, which suppressed the direct binding of miR-29b to the 3′-untranslated region of type I collagen (COL1A1). We showed that ectopic expression of miR-29b ameliorated various myofibroblast phenotypes and the expression of α-smooth muscle actin (α-SMA), COL1A1, and fibronectin (FN1) in fBMFs. In OSF tissues, we found that the expression of miR-29b was downregulated and there was a negative correlation between miR-29b and these fibrosis markers. Lastly, we demonstrate that arecoline stimulated the upregulation of H19 through the transforming growth factor (TGF)-β pathway. Altogether, this study suggests that increased TGF-β secretion following areca nut chewing may induce the upregulation of H19, which serves as a natural sponge for miR-29b and impedes its antifibrotic effects.

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.

scholarly journals Crosstalk between Long-Term Sublethal Oxidative Stress and Detrimental Inflammation as Potential Drivers for Age-Related Retinal Degeneration

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Lara Macchioni ◽  
Davide Chiasserini ◽  
Letizia Mezzasoma ◽  
Magdalena Davidescu ◽  
Pier Luigi Orvietani ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Age Related Macular Degeneration ◽  
Inflammasome Activation ◽  
Related Factor ◽  
Nuclear Factor ◽  
Rpe Cells ◽  
Age Related ◽  
Oxidative Insult

Age-related retinal degenerations, including age-related macular degeneration (AMD), are caused by the loss of retinal pigmented epithelial (RPE) cells and photoreceptors. The pathogenesis of AMD, deeply linked to the aging process, also involves oxidative stress and inflammatory responses. However, the molecular mechanisms contributing to the shift from healthy aging to AMD are still poorly understood. Since RPE cells in the retina are chronically exposed to a pro-oxidant microenvironment throughout life, we simulated in vivo conditions by growing ARPE-19 cells in the presence of 10 μM H2O2 for several passages. This long-term oxidative insult induced senescence in ARPE-19 cells without affecting cell proliferation. Global proteomic analysis revealed a dysregulated expression in proteins involved in antioxidant response, mitochondrial homeostasis, and extracellular matrix organization. The analyses of mitochondrial functionality showed increased mitochondrial biogenesis and ATP generation and improved response to oxidative stress. The latter, however, was linked to nuclear factor-κB (NF-κB) rather than nuclear factor erythroid 2–related factor 2 (Nrf2) activation. NF-κB hyperactivation also resulted in increased pro-inflammatory cytokines expression and inflammasome activation. Moreover, in response to additional pro-inflammatory insults, senescent ARPE-19 cells underwent an exaggerated inflammatory reaction. Our results indicate senescence as an important link between chronic oxidative insult and detrimental chronic inflammation, with possible future repercussions for therapeutic interventions.

scholarly journals mTOR inhibitors potentially reduce TGF-β2-induced fibrogenic changes in trabecular meshwork cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nozomi Igarashi ◽  
Megumi Honjo ◽  
Makoto Aihara
Keyword(s):  
Trabecular Meshwork ◽  
Transforming Growth Factor ◽  
Smooth Muscle Actin ◽  
Mtor Inhibitors ◽  
In Vivo Model ◽  
Type I ◽  
Fibrotic Response ◽  
Alpha Smooth Muscle Actin

AbstractWe examined the effects of mTOR inhibitors on the fibrotic response induced by transforming growth factor-beta2 (TGF-β2) in cultured human trabecular meshwork (hTM) cells. TGF-β2-induced expression of fibronectin, collagen type I, alpha 1 chain (COL1A1), and alpha-smooth muscle actin (αSMA) in hTM cells was examined in the presence or absence of mTOR inhibitors using quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. The migration rates of hTM cells were examined in the presence of TGF-β2 with or without mTOR inhibitors. An in vitro study showed that the expression of fibronectin, COL1A1, and αSMA was upregulated by TGF-β2 treatment of hTM cells; such upregulation was significantly suppressed by mTOR inhibitors. The inhibitors significantly reduced the migration rate of TGF-β2-stimulated hTM cells. mTOR inhibitors may usefully reduce the fibrotic response of hTM cells and we may have to explore if it is also effective in in vivo model.

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