scholarly journals Nuclear factor erythroid 2-related factor 2 activation mediates hyperhomocysteinemia-associated lipolysis suppression in adipocytes

2018 ◽  
Vol 243 (11) ◽  
pp. 926-933 ◽  
Author(s):  
Xin Li ◽  
Yuhong Cheng ◽  
Xiuli Zhong ◽  
Bing Zhang ◽  
Zhiwei Bao ◽  
...  

Hyperhomocysteinemia (HHcy) is associated with suppressed lipolytic response in adipocytes/adipose tissue, however, the underlying mechanism remains to be extensively studied. Nuclear factor erythroid 2-related factor 2 (Nrf2), a master transcriptional factor regulating antioxidant generation, has been recently reported to mediate lipid metabolism. Employing both fully differentiated 3T3-L1 adipocytes and male C57BL/6 mice, in the present study, we investigated the potential involvement of Nrf2 activation in HHcy-mediated lipolytic suppression. Our results showed that homocysteine (Hcy) treatment resulted in suppressed lipolysis, evidenced by increased intracellular triglyceride (TG) accumulation, decreased glycerol and free fatty acid (FFA) in fully differentiated 3T3-L1 adipocytes. Interestingly, Hcy exposure was associated with Nrf2 activation in adipocytes. Further studies showed that Nrf2 knockdown via siRNA transfection ameliorated Hcy-induced glycerol release in adipocytes. On the contrary, Nrf2 activators, epigallocatechin gallate (EGCG) and tert-butylhydroquinone (t-BHQ), increased intracellular TG content and decreased glycerol release in adipocytes. Importantly, our in vitro observations were corroborated by our in vivo findings, in which Hcy feeding (0.1% wt/vol) for four weeks induced Nrf2 expression in adipose tissue and lowered circulating FFA and glycerol levels in mice. Furthermore, EGCG injection (5 mg/kg/d) decreased circulating glycerol levels in comparison to the control group in mice. In conclusion, these results indicated that Nrf2 activation in response to HHcy plays an important role in mediating Hcy-suppressed lipolysis in adipocytes.

2021 ◽  
Author(s):  
Ding-Chao Zhu ◽  
Yi-Han Wang ◽  
Jia-Hao Lin ◽  
Zhi-Min Miao ◽  
Jia-Jing Xu ◽  
...  

Osteoarthritis (OA) is a common degenerative joint disease characterized by articular cartilage degeneration and inflammation. Currently, there is hardly any effective treatment for OA due to its complicated pathology and...


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 945
Author(s):  
Marika Lanza ◽  
Giovanna Casili ◽  
Giovanna Loredana La Torre ◽  
Daniele Giuffrida ◽  
Archimede Rotondo ◽  
...  

Marine species represent a great source of biologically active substances; Actinia equina (AE), an Anthozoa Cnidaria belonging to the Actinidiae family, have been proposed as original food and have already been included in several cooking recipes in local Mediterranean shores, and endowed with excellent nutraceutical potential. The aim of this study was to investigate some unexplored features of AE, through analytical screening and an in-vitro and in-vivo model. An in-vitro study, made on RAW 264.7 stimulated with H2O2, showed that the pre-treatment with AE exerted an antioxidant action, reducing lipid peroxidation and up-regulating antioxidant enzymes. On the other hand, the in-vivo study over murine model demonstrated that the administration of AE extracts is able to reduce the carrageenan (CAR)-induced paw edema. Furthermore, the histological damage due to the neutrophil infiltration is prevented, and this highlights precious anti-inflammatory features of the interesting food-stuff. Moreover, it was assessed that AE extract modulated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and The nuclear factor erythroid 2–related factor 2 (Nrf-2) pathways. In conclusion, our data demonstrated that thanks to the antioxidant and anti-inflammatory properties, AE extract could be used as a new food supplement for inflammatory pathology prevention.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Rui Li ◽  
Tianfeng Liu ◽  
Juanjuan Shi ◽  
Wenqing Luan ◽  
Xuan Wei ◽  
...  

Abstract Background Epithelial ovarian cancer (EOC) is the most lethal cancer in female genital tumors. New disease markers and novel therapeutic strategies are urgent to identify considering the current status of treatment. Receptor tyrosine kinases family plays critical roles in embryo development and disease progression. However, ambivalent research conclusions of ROR2 make its role in tumor confused and the underlying mechanism is far from being understood. In this study, we sought to clarify the effects of ROR2 on high-grade serous ovarian carcinoma (HGSOC) cells and reveal the mechanism. Methods Immunohistochemistry assay and western-blot assay were used to detect proteins expression. ROR2 overexpression adenovirus and Lentivirus were used to create ROR2 overexpression model in vitro and in vivo, respectively. MTT assay, colony formation assay and transwell assay were used to measure the proliferation, invasion and migration ability of cancer cells. Flow cytometry assay was used to detect cell apoptosis rate. Whole transcriptome analysis was used to explore the differentially expressed genes between ROR2 overexpression group and negative control group. SiRNA targeted IRE1α was used to knockdown IRE1α. Kira6 was used to inhibit phosphorylation of IRE1α. Results Expression of ROR2 was significantly lower in HGSOC tissues compared to normal fallopian tube epithelium or ovarian surface epithelium tissues. In HGSOC cohort, patients with advanced stages or positive lymph nodes were prone to express lower ROR2. Overexpression of ROR2 could repress the proliferation of HGSOC cells and induce cell apoptosis. RNA sequencing analysis indicated that ROR2 overexpression could induce unfold protein response. The results were also confirmed by upregulation of BIP and phosphorylated IRE1α. Furthermore, pro-death factors like CHOP, phosphorylated JNK and phosphorylated c-Jun were also upregulated. IRE1α knockdown or Kira6 treatment could reverse the apoptosis induced by ROR2 overexpression. Finally, tumor xenograft experiment showed ROR2 overexpression could significantly repress the growth rate and volume of transplanted tumors. Conclusions Taken together, ROR2 downregulation was associated with HGSOC development and progression. ROR2 overexpression could repress cell proliferation and induce cell apoptosis in HGSOC cells. And the underlying mechanism might be the activation of IRE1α/JNK/CHOP pathway induced by ROR2.


Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1576 ◽  
Author(s):  
Shasika Jayarathne ◽  
April Stull ◽  
Alexandra Miranda ◽  
Shane Scoggin ◽  
Kate Claycombe-Larson ◽  
...  

Obesity increases adipose tissue inflammation and secretion of pro-inflammatory adipokines, which have systemic effects on the organism’s health status. Our objective was to dissect mechanisms of anti-inflammatory effects of tart cherry (TC) in adipose tissue of Zucker fatty rats, and cultured 3T3-L1 adipocytes. Rats were fed either a control diet, or 4% TC powder diets for eight weeks. Body and epididymal fat pad weights were not significantly different between control and TC groups. However, rats fed the TC diet had significantly reduced adipose tissue inflammation (p < 0.05), as determined by reduced mRNA levels of pro-inflammatory markers including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), interleukin-1beta (IL-1β), monocyte chemoattractant protein 1 (MCP-1), inducible nitric oxide synthase (iNOS), and CD-11b, and increased mRNA levels of type-1 arginase (Arg-1) anti-inflammatory marker. Consistent with these in vivo results, TC significantly decreased expression of IL-6 mRNA and protein levels in lipopolysaccharide (LPS) stimulated adipocytes compared to those stimulated with LPS, but no TC. Moreover, both in vivo (rat adipose tissue) and in vitro (3T3-L1 adipocytes), phosphorylation of p65-NF-κB subunit was significantly reduced by TC. Additionally, TC decreased mRNA expression of fatty acid synthase (FASN), and increased expression of peroxisome proliferator-activated receptor alpha (PPARα), master regulator of lipid oxidation, and anti-oxidant markers nuclear factor erythroid-derived 2-related factor (NRFs) in both models. In conclusion, our findings indicate that TC downregulates inflammation in part via the nuclear factor kappa B (NF-κB) pathway in adipose tissue. Thus, TC may serve as a potential intervention to reduce obesity-associated inflammation.


1986 ◽  
Vol 250 (6) ◽  
pp. H1127-H1135
Author(s):  
S. E. Martin ◽  
E. L. Bockman

Intravenous norepinephrine increases glycerol release and blood flow in adipose tissue. The vasodilation may be an indirect effect of norepinephrine through the production of adenosine. Adenosine increases glucose uptake and inhibits lipolysis in vitro. To test whether adenosine regulates blood flow and/or metabolism in vivo, adenosine deaminase (ADA) was infused intra-arterially into the inguinal fat pads of anesthetized dogs. In unstimulated tissues, ADA (n = 7) significantly increased vascular resistance and significantly decreased glucose uptake compared with the effects of a control (boiled deaminase, n = 6) infusion. ADA completely blocked the norepinephrine-induced vasodilation (n = 6). No potentiation of basal or catecholamine-stimulated lipolysis was observed with ADA. The presence of ADA in the interstitial space was verified by analysis of lymph effluents. Interstitial levels of ADA were inversely correlated with the tissue contents of adenosine. These data support the hypothesis that adenosine is a regulator of blood flow in basal and stimulated adipose tissue. Adenosine also appears to regulate glucose uptake, but not lipolysis, in vivo.


2016 ◽  
Vol 36 (5) ◽  
Author(s):  
Jiang-Ying Ru ◽  
Hai-Dong Xu ◽  
Dai Shi ◽  
Jun-Bo Pan ◽  
Xiao-Jin Pan ◽  
...  

Ulinastatin, a urinary trypsin inhibitor (UTI), is widely used to clinically treat lipopolysaccharide (LPS)-related inflammatory disorders recently. Adherent pathogen-associated molecular patterns (PAMPs), of which LPS is the best-studied and classical endotoxin produced by Gram-negative bacteria, act to increase the biological activity of osteopedic wear particles such as polymethyl-methacrylate (PMMA) and titanium particles in cell culture and animal models of implant loosening. The present study was designed to explore the inhibitory effect of UTI on osteoclastogenesis and inflammatory osteolysis in LPS/PMMA-mediated Raw264.7 cells and murine osteolysis models, and investigate the potential mechanism. The in vitro study was divided into the control group, LPS-induced group, PMMA-stimulated group and UTI-pretreated group. UTI (500 or 5000 units/ml) pretreatment was followed by PMMA (0.5 mg/ml) with adherent LPS. The levels of inflammatory mediators including tumour necrosis factor-α (TNF-α), matrixmetallo-proteinases-9 (MMP-9) and interleukin-6 (IL-6), receptor activation of nuclear factor NF-κB (RANK), and cathepsin K were examined and the amounts of phosphorylated I-κB, MEK, JNK and p38 were measured. In vivo study, murine osteolysis models were divided into the control group, PMMA-induced group and UTI-treated group. UTI (500 or 5000 units/kg per day) was injected intraperitoneally followed by PMMA suspension with adherent LPS (2×108 particles/25 μl) in the UTI-treated group. The thickness of interfacial membrane and the number of infiltrated inflammatory cells around the implants were assessed, and bone mineral density (BMD), trabecular number (Tb.N.), trabecular thickness (Tb.Th.), trabecular separation (Tb.Sp.), relative bone volume over total volume (BV/TV) of distal femur around the implants were calculated. Our results showed that UTI pretreatment suppressed the secretion of proinflammatory cytokines including MMP-9, IL-6, TNF-α, RANK and cathepsin K through down-regulating the activity of nuclear factor kappa B (NF-κB) and MAPKs partly in LPS/PMMA-mediated Raw264.7 cells. Finally, UTI treatment decreased the inflammatory osteolysis reaction in PMMA-induced murine osteolysis models. In conclusion, these results confirm the anti-inflammatory potential of UTI in the prevention of particle disease.


2015 ◽  
Vol 43 (4) ◽  
pp. 669-673 ◽  
Author(s):  
Mingzhan Xue ◽  
Hiroshi Momiji ◽  
Naila Rabbani ◽  
Till Bretschneider ◽  
David A. Rand ◽  
...  

The discovery that nuclear factor erythroid 2-related factor 2 (Nrf2) undergoes translocational oscillations from cytoplasm to nucleus in human cells with frequency modulation linked to activation of a stress-stimulated cytoprotective response raises the prospect that the Nrf2 works mechanistically analogous to a wireless sensor. Herein, we consider how this new model of Nrf2 oscillation resolves previous inexplicable experimental findings on Nrf2 regulation and why it is fit-for-purpose. Further investigation is required to assess how generally applicable the oscillatory mechanism is and if characteristics of this regulatory control can be found in vivo. It suggests there are multiple, potentially re-enforcing receptors for Nrf2 activation, indicating that potent Nrf2 activation for improved health and treatment of disease may be achieved through combination of Nrf2 system stimulants.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jin-Feng Xu ◽  
Yan Wan ◽  
Fei Tang ◽  
Lu Chen ◽  
Yu Yang ◽  
...  

Chemoresistance has become a prevalent phenomenon in cancer therapy, which alleviates the effect of chemotherapy and makes it difficult to break the bottleneck of the survival rate of tumor patients. Current approaches for reversing chemoresistance are poorly effective and may cause numerous new problems. Therefore, it is urgent to develop novel and efficient drugs derived from natural non-toxic compounds for the reversal of chemoresistance. Researches in vivo and in vitro suggest that ginsenosides are undoubtedly low-toxic and effective options for the reversal of chemoresistance. The underlying mechanism of reversal of chemoresistance is correlated with inhibition of drug transporters, induction of apoptosis, and modulation of the tumor microenvironment(TME), as well as the modulation of signaling pathways, such as nuclear factor erythroid-2 related factor 2 (NRF2)/AKT, lncRNA cancer susceptibility candidate 2(CASC2)/ protein tyrosine phosphatase gene (PTEN), AKT/ sirtuin1(SIRT1), epidermal growth factor receptor (EGFR)/ phosphatidylinositol 3-kinase (PI3K)/AKT, PI3K/AKT/ mammalian target of rapamycin(mTOR) and nuclear factor-κB (NF-κB). Since the effects and the mechanisms of ginsenosides on chemoresistance reversal have not yet been reviewed, this review summarized comprehensively experimental data in vivo and in vitro to elucidate the functional roles of ginsenosides in chemoresistance reversal and shed light on the future research of ginsenosides.


2020 ◽  
Author(s):  
Yan Wang ◽  
Tian Liu ◽  
Jun-fei Wang ◽  
Bao-yi Liu ◽  
Jin-xiang Wu ◽  
...  

Abstract Background Asthma is a common respiratory disease characterized by chronic airway inflammation. As a novel inflammatory mediator, follistatin-like protein 1 (FSTL1) can activate immune reaction, suggesting that it may contribute to inflammatory disorders such as asthma. Besides, there are growing evidences that nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) / Interleukin (IL)-1β axis participates in asthma. In this study, we investigated the role of FSTL1 in allergic airway inflammation and its underlying mechanism of activating NLRP3 inflammasome. Methods Circulating FSTL1 and IL-1β levels were quantified in serum of asthmatic patients and controls. Whole-body ablation Fstl1 heterozygous mice (Fstl1 +/- ) and control group were assessed after the experimental treatment. The effects of FSTL1 on NLRP3 inflammasome were also tested in primary macrophages of mice in vitro. Results The concentration of FSTL1 and IL-1β in serum of asthmatic patients were elevated compared with controls and were positively correlated. FSTL1 deficiency ameliorated infiltration of inflammatory cells,corresponding pathological changes,cytokine responses (IL-1β, IL-5,IL-13), mucous hypersecretion and hyper-responsiveness of airway after Ovalbumin (OVA) exposure in the mouse model. Additionally, inhibition of NLRP3 with MCC950 attenuated FSTL1-induced activation of NLRP3 inflammasome and airway inflammation in vivo and vitro. Conclusions Our data showed that FSTL1 played an important role in allergic airway inflammation by activating NLRP3 inflammasome, providing the possibility that FSTL1 could be applied as a therapeutic strategy on asthma.


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