Upregulation of osteopontin expression is involved in the development of nonalcoholic steatohepatitis in a dietary murine model

2004 ◽  
Vol 287 (1) ◽  
pp. G264-G273 ◽  
Author(s):  
Atul Sahai ◽  
Padmini Malladi ◽  
Hector Melin-Aldana ◽  
Richard M. Green ◽  
Peter F. Whitington

The pathogenesis of nonalcoholic steatohepatitis (NASH) is poorly defined. Feeding mice a diet deficient in methionine and choline (MCD diet) induces experimental NASH. Osteopontin (OPN) is a Th1 cytokine that plays an important role in several fibroinflammatory diseases. We examined the role of OPN in the development of experimental NASH. A/J mice were fed MCD or control diet for up to 12 wk, and serum alanine aminotransferase (ALT), liver histology, oxidative stress, and the expressions of OPN, TNF-α, and collagen I were assessed at various time points. MCD diet-fed mice developed hepatic steatosis starting after 1 wk and inflammation by 2 wk; serum ALT increased from day 3. Hepatic collagen I mRNA expression increased during 1–4 wk, and fibrosis appeared at 8 wk. OPN protein expression was markedly increased on day 1 of MCD diet and persisted up to 8 wk, whereas OPN mRNA expression was increased at week 4. TNF-α expression was increased from day 3 to 2 wk, and evidence of oxidative stress did not appear until 8 wk. Increased expression of OPN was predominantly localized in hepatocytes. Hepatocytes in culture also produced OPN, which was stimulated by transforming growth factor-β and TNF-α. Moreover, MCD diet-induced increases in serum ALT levels, hepatic inflammation, and fibrosis were markedly reduced in OPN−/− mice when compared with OPN+/+ mice. In conclusion, our results demonstrate an upregulation of OPN expression early in the development of steatohepatitis and suggest an important role for OPN in signaling the onset of liver injury and fibrosis in experimental NASH.

2021 ◽  
Vol 20 (9) ◽  
pp. 1961-1968
Author(s):  
Wei Wei ◽  
Liefeng Ji ◽  
Wanli Duan ◽  
Jiang Zhu

Purpose: To investigate the effect of Klotho and FOXO1/3 on the CH viability in OA.Methods: The survival rate of CHs, Klotho and FOXO1/3 protein expression, and ROS production were measured in the OA cartilages of different degenerative phases. H2O2 was also used to injure CHs, and the cell viability, Klotho and FOXO1/3 expressions, as well as ROS levels were investigated to clarify the effect of exogenic Klotho on the injured CHs. Additionally, in order to verify the role of FOXO1/3 in Klotho-treated CHs, SOD2, GPX1, inflammatory factors, collagen I/II, SOX9, and Runx-2 levels were analyzed by silencing FOXO1 and FOXO3 expression via siRNA transfection.Results: Klotho and FOXO1/3 expressions significantly decreased, and ROS production increased in severely human OA cartilage (p <0.05). Besides, H2O2 affected CHs viability with the suppression of Klotho and FOXO1/3 expression but ROS production was elevated. Exogenic Klotho application partly reversed the injury caused by H2O2. Furthermore, Klotho treatment of the injured CHs contributed to SOD2 and GPX1 expressions, and suppressed IL-1β, IL-6, TNF-α and MMP-13 production, resulting in  the upregulation of collagen II and SOX9 as well as downregulation of collagen I and Runx-2. However, the protective effect of Klotho was weakened by FOXO1 and FOXO3 gene silencing.Conclusion: Klotho protects CHs viability by suppressing oxidative stress and inflammation, which is associated with the mediation of FOXO1 and FOXO3. These findings provide new insights into the treatment of OA.


2015 ◽  
Vol 308 (4) ◽  
pp. G298-G312 ◽  
Author(s):  
Diptadip Dattaroy ◽  
Sahar Pourhoseini ◽  
Suvarthi Das ◽  
Firas Alhasson ◽  
Ratanesh Kumar Seth ◽  
...  

Hepatic fibrosis in nonalcoholic steatohepatitis (NASH) is the common pathophysiological process resulting from chronic liver inflammation and oxidative stress. Although significant research has been carried out on the role of leptin-induced NADPH oxidase in fibrogenesis, the molecular mechanisms that connect the leptin-NADPH oxidase axis in upregulation of transforming growth factor (TGF)-β signaling have been unclear. We aimed to investigate the role of leptin-mediated upregulation of NADPH oxidase and its subsequent induction of micro-RNA 21 (miR21) in fibrogenesis. Human NASH livers and a high-fat (60% kcal) diet-fed chronic mouse model, where hepatotoxin bromodichloromethane was used to induce NASH, were used for this study. To prove the role of the leptin-NADPH oxidase-miR21 axis, mice deficient in genes for leptin, p47phox, and miR21 were used. Results showed that wild-type mice and human livers with NASH had increased oxidative stress, increased p47phox expression, augmented NF-κB activation, and increased miR21 levels. These mice and human livers showed increased TGF-β, SMAD2/3-SMAD4 colocalizations in the nucleus, increased immunoreactivity against Col1α, and α-SMA with a concomitant decrease in protein levels of SMAD7. Mice that were deficient in leptin or p47phox had decreased activated NF-κB and miR21 levels, suggesting the role of leptin and NADPH oxidase in inducing NF-κB-mediated miR21 expression. Further miR21 knockout mice had decreased colocalization events of SMAD2/3-SMAD4 in the nucleus, increased SMAD7 levels, and decreased fibrogenesis. Taken together, the studies show the novel role of leptin-NADPH oxidase induction of miR21 as a key regulator of TGF-β signaling and fibrogenesis in experimental and human NASH.


2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Guoliang Meng ◽  
Jinbiao Zhu ◽  
Yujiao Xiao ◽  
Zhengrong Huang ◽  
Yuqing Zhang ◽  
...  

Hydrogen sulfide (H2S) is a gasotransmitter which regulates multiple cardiovascular functions. However, the precise roles of H2S in modulating myocardial fibrosisin vivoand cardiac fibroblast proliferationin vitroremain unclear. We investigated the effect of GYY4137, a slow-releasing H2S donor, on myocardial fibrosis. Spontaneously hypertensive rats (SHR) were administrated with GYY4137 by intraperitoneal injection daily for 4 weeks. GYY4137 decreased systolic blood pressure and inhibited myocardial fibrosis in SHR as evidenced by improved cardiac collagen volume fraction (CVF) in the left ventricle (LV), ratio of perivascular collagen area (PVCA) to lumen area (LA) in perivascular regions, reduced hydroxyproline concentration, collagen I and III mRNA expression, and cross-linked collagen. GYY4137 also inhibited angiotensin II- (Ang II-) induced neonatal rat cardiac fibroblast proliferation, reduced the number of fibroblasts in S phase, decreased collagen I and III mRNA expression and protein synthesis, attenuated oxidative stress, and suppressedα-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1) expression as well as Smad2 phosphorylation. These results indicate that GYY4137 improves myocardial fibrosis perhaps by a mechanism involving inhibition of oxidative stress, blockade of the TGF-β1/Smad2 signaling pathway, and decrease inα-SMA expression in cardiac fibroblasts.


Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 569
Author(s):  
Jeng-Shyong Chan ◽  
Po-Jen Hsiao ◽  
Wen-Fang Chiang ◽  
Prabir Roy-Chaudhury

Haemodialysis vascular access (VA) dysfunction is a major cause of morbidity in haemodialysis (HD) patients. Primary venous outflow occlusion and restenosis after percutaneous transluminal angioplasty (PTA) are two major obstacles for the long-term use of dialysis VA. It remains unclear whether oxidative stress markers can be used as predictors for thrombotic occlusion of VA and progressive stenosis dysfunction demanding PTA. All routine HD patients at one teaching hospital participated in this study including ankle-brachial index (ABI) examinations and serum oxidative stress markers. The serum oxidative stress markers (high-sensitivity C-reactive protein (hs-CRP), matrix metalloproteinase-2 (MMP-2), MMP-9, homocysteine, asymmetrical dimethylarginine (ADMA), nitrate oxidase (NO), tumour necrosis factor-α (TNF-α), monocyte chemotactic protein 1 (MCP-1), interleukin-1β (IL-1β), and transforming growth factor-β (TGF-β)) were measured using immunosorbent assays in 159 HD patients (83 men and 76 women; mean age: 65 ± 12 years). The participants met the following criteria: (1) received regular HD treatment for at least 6 months, without clinical evidence of acute or chronic inflammation, recent myocardial infarction, unstable angina or circulatory congestion; and (2) received an arteriovenous fistula (AVF)/arteriovenous graft (AVG: polytetrafluoroethylene, PTFE) as the current VA for more than 6 months, without interventions within the last 6 months. All the participants were followed up clinically for up to 12 months to estimate the amount of primary thrombotic occlusion and VA dysfunction demanding PTA. During the 12-month observation, 24 patients (15.1%) had primary thrombotic occlusion of VAs. Another 24 patients (15.1%) required PTA because of clinical dysfunction of access. Additionally, during the follow-up period, restenosis occurred in 12 patients (50% of 24 patients). The access types of arteriovenous grafts (AVGs) and a diagnosis of peripheral arterial occlusive disease (PAOD) were two strong predictors for acute thrombotic events of VA (hazard ratio (HR): 16.93 vs. 2.35; p < 0.001 vs. 0.047). Comparing dysfunctional with non-dysfunctional VAs, up to 27.7% of patients with high levels of ADMA (>0.6207 μM, N = 65) received required PTA compared with 4.4% of those with low levels (≤0.6207 μM; N = 90; p < 0.001). In multivariate analysis, the plasma baseline levels of ADMA independently conferred nearly 4.55 times the risk of primary stenotic dysfunction of HD VA (HR: 4.55; 95% confidence interval: 1.20 to 17.26; p = 0.026). In conclusion, our findings suggest the role of ADMA in the development of symptomatic VA dysfunction. Additionally, PAOD severity can be used in clinical practice to predict whether acute thrombotic occlusion of VA will easily occur in HD patients.


2010 ◽  
Vol 299 (6) ◽  
pp. F1328-F1338 ◽  
Author(s):  
Yasutaka Maeda ◽  
Toyoshi Inoguchi ◽  
Ryoko Takei ◽  
Fumi Sawada ◽  
Shuji Sasaki ◽  
...  

Accumulating evidence suggests that the intrarenal renin-angiotensin system may be involved in the progression of diabetic nephropathy. Chymase is a potent local angiotensin II-forming enzyme in several species, including humans and hamsters. However, the pathophysiological role of chymase is not fully understood. Here, we report a causal role of chymase in diabetic nephropathy and the therapeutic effectiveness of chymase inhibition. In the present study, renal chymase expression was markedly upregulated in streptozotocin-induced diabetic hamsters. Oral administration of a specific chymase inhibitor, TEI-F00806, completely ameliorated proteinuria, the overexpression of transforming growth factor-β and fibronectin in glomeruli, and renal mesangial expansion, by normalizing the increase in intrarenal angiotensin II levels in diabetic hamsters independently of blood pressure levels. In contrast, ramipril did not show such sufficient effects. These effects occurred in parallel with improvements in superoxide production and expression of NAD(P)H oxidase components [NAD(P)H oxidase 4 and p22 phox] in glomeruli. This study showed for the first time that chymase inhibition may protect against elevated intrarenal angiotensin II levels, oxidative stress, and renal dysfunction in diabetes. These findings suggest that chymase offers a new therapeutic target for diabetic nephropathy.


Immuno ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 212-222
Author(s):  
Amira Mohammed Ali ◽  
Hiroshi Kunugi

The increased prevalence of neurodegenerative diseases, especially during the COVID-19 outbreak, necessitates the search for natural immune- and cognitive-enhancing agents. 10-Hydroxy-trans-2-decenoic acid (10-H2DA), the main fatty acid of royal jelly, has several pharmacological activities. Given the fundamental role of astrocytes in regulating immune responses of the central nervous system, we used cortical astrocytes to examine the effect of 10-H2DA on the expression of genes associated with neuroinflammation and the production of neurotrophins, as well as cellular resistance to H2O2-induced cytotoxicity. Astrocytes, pretreated with a range of concentrations of 10-H2DA for 24 h, were exposed to lipopolysaccharide (LPS) for 3 h, after which the expression of proinflammatory cytokines (IL-1β, IL-6, and tumor necrosis factor-α (TNF-α)) and neurotrophic factors (BDNF, GDNF, and IGF-1) was evaluated. In the absence of LPS, 10-H2DA had no significant effect on the mRNA expression of neurotrophins or cytokines except for IL-1β, which significantly increased with low doses of 10-H2DA (3 µM). 10-H2DA (10 µM) pretreatment of LPS-stimulated cells did not significantly inhibit the expression of cytokine encoding genes; however, it significantly lowered the mRNA expression of GDNF and tended to decrease BDNF and IGF-1 expression compared with LPS alone. Additionally, 10-H2DA did not protect astrocytes against H2O2-induced oxidative stress. Our data indicate no anti-inflammatory, antioxidant, or neurotrophic effect of 10-H2DA in astrocytes undergoing inflammation or oxidative stress. The effect of IGF-1 inhibition by 10-H2DA on neuronal ketogenesis needs investigation.


Author(s):  
Amirhooman Asadi ◽  
Davood Yaghobi Nezhad ◽  
Amirreza Rafiei Javazm ◽  
Parisa Khanicheragh ◽  
Ladan Mashouri ◽  
...  

Transforming growth factor-β (TGF-β) induces pro-inflammatory cytokines expression including interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and these cytokines are associated with the development of atherosclerosis. Curcumin has anti-atherogenic effects and anti-inflammatory properties in the vascular wall, but the relative mechanisms are almost unknown. In the present study, we investigate the effect of curcumin on modulating the pro-inflammatory action of TGF-β in human vascular smooth muscle cells (VSMCs) and its molecular mechanisms. Cultured VSMCs were seeded into several groups: a control group (untreated group), a group treated with TGF-β, and several groups treated with TGF-β plus inhibitors. The cells were pre-treated with diphenyleneiodonium chloride, DPI, (20 μM), curcumin (5, 10 and 20 μM) and N-Acetyl-L-Cysteine, NAC, (10 mM) and then TGF-β (5 ng/mL) was added to the culture medium. The mRNA levels of IL-6 and TNF-α were detected by quantitative Real-Time Polymerase Chain Reaction. For monitoring the Smad2 linker region phosphorylation (pSmad2L), the western-blotting technique was applied and reactive oxygen species (ROS) generation was measured by utilizing 2′,7′-dichlorofluorescein diacetate-based assay. TGF-β increased the mRNA expression of IL-6 (p=0.02 and p=0.001) and TNF-α (p =0.014 and p=0.001) in a time-dependent manner, ROS production (p=0.03) and Smad2L phosphorylation (p=0.015). Pre-treatment with curcumin, DPI and NAC inhibited TGF-β–induced IL-6 (p=0.04) and TNF-α (p=0.001) mRNA expression, Smad2L phosphorylation (p=0.02) and ROS production (0.03). Pharmacological inhibition by Curcumin blocks TGF-β–induced ROS production, Smad2L phosphorylation, and IL-6 and TNF-α mRNA expression in human VSMCs.    


2020 ◽  
Vol 25 (40) ◽  
pp. 4310-4317 ◽  
Author(s):  
Lichao Sun ◽  
Shouqin Ji ◽  
Jihong Xing

Background/Aims: Central pro-inflammatory cytokine (PIC) signal is involved in neurological deficits after transient global ischemia induced by cardiac arrest (CA). The present study was to examine the role of microRNA- 155 (miR-155) in regulating IL-1β, IL-6 and TNF-α in the hippocampus of rats with induction of CA. We further examined the levels of products of oxidative stress 8-isoprostaglandin F2α (8-iso PGF2α, indication of oxidative stress); and 8-hydroxy-2’-deoxyguanosine (8-OHdG, indication of protein oxidation) after cerebral inhibition of miR-155. Methods: CA was induced by asphyxia and followed by cardiopulmonary resuscitation in rats. ELISA and western blot analysis were used to determine the levels of PICs and products of oxidative stress; and the protein expression of NADPH oxidase (NOXs) in the hippocampus. In addition, neurological severity score and brain edema were examined to assess neurological functions. Results: We observed amplification of IL-1β, IL-6 and TNF-α along with 8-iso PGF2α and 8-OHdG in the hippocampus of CA rats. Cerebral administration of miR-155 inhibitor diminished upregulation of PICs in the hippocampus. This also attenuated products of oxidative stress and upregulation of NOX4. Notably, inhibition of miR-155 improved neurological severity score and brain edema and this was linked to signal pathways of PIC and oxidative stress. Conclusion: We showed the significant role of blocking miR-155 signal in improving the neurological function in CA rats likely via inhibition of signal pathways of neuroinflammation and oxidative stress, suggesting that miR-155 may be a target in preventing and/or alleviating development of the impaired neurological functions during CA-evoked global cerebral ischemia.


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