scholarly journals GPA Peptide-Induced Nur77 Localization at Mitochondria Inhibits Inflammation and Oxidative Stress through Activating Autophagy in the Intestine

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Zhao Deng ◽  
Qi Liu ◽  
Miaomiao Wang ◽  
Hong-Kui Wei ◽  
Jian Peng

Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. Nur77, belongs to the NR4A subfamily of nuclear hormone receptors, plays a critical role in controlling the pathology of colitis. The aim of this study is to investigate the protection effect and mechanism of Gly-Pro-Ala (GPA) peptide, isolated from fish skin gelatin hydrolysate, in a mouse model of dextran sulfate sodium- (DSS-) induced colitis and intestinal epithelial cells (IECs) stimulated by lipopolysaccharide (LPS). In vivo, GPA treatment alleviates DSS-induced weight loss, disease activity index (DAI) increase, colon length shortening, and colonic pathological damage. Production of proinflammatory cytokines, ROS, and MDA is significantly decreased by GPA treatment. In vitro, GPA significantly inhibits proinflammatory cytokine production, cytotoxicity, ROS, and MDA in IECs. Furthermore, GPA induces autophagy to suppress inflammation and oxidative stress. GPA promotes Nur77 translocation from the nucleus to mitochondria where it facilitates Nur77 interaction with TRAF6 and p62, leading to the induction of autophagy. In addition, GPA contributed to the maintenance of tight junction architecture in vivo and in vitro. Taken together, GPA, as a Nur77 modulator, could exert anti-inflammatory and antioxidant effects by inducing autophagy in IECs, suggesting that GPA may be promising for the prevention of colitis.

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 507
Author(s):  
Rosaria Meccariello ◽  
Stefania D’Angelo

Aging and, particularly, the onset of age-related diseases are associated with tissue dysfunction and macromolecular damage, some of which can be attributed to accumulation of oxidative damage. Recently, growing interest has emerged on the beneficial effects of plant-based diets for the prevention of chronic diseases including obesity, diabetes, and cardiovascular disease. Several studies collectively suggests that the intake of polyphenols and their major food sources may exert beneficial effects on improving insulin resistance and related diabetes risk factors, such as inflammation and oxidative stress. They are the most abundant antioxidants in the diet, and their intake has been associated with a reduced aging in humans. Polyphenolic intake has been shown to be effective at ameliorating several age-related phenotypes, including oxidative stress, inflammation, impaired proteostasis, and cellular senescence, both in vitro and in vivo. In this paper, effects of these phytochemicals (either pure forms or polyphenolic-food) are reviewed and summarized according to affected cellular signaling pathways. Finally, the effectiveness of the anti-aging preventive action of nutritional interventions based on diets rich in polyphenolic food, such as the diets of the Blue zones, are discussed.


2021 ◽  
Vol 96 ◽  
pp. 107593
Author(s):  
Yiming Ma ◽  
Lijuan Luo ◽  
Xiangming Liu ◽  
Herui Li ◽  
Zihang Zeng ◽  
...  

2005 ◽  
Vol 25 (1) ◽  
pp. 324-335 ◽  
Author(s):  
Ho-Geun Yoon ◽  
Youngsok Choi ◽  
Philip A. Cole ◽  
Jiemin Wong

ABSTRACT A central question in histone code theory is how various codes are recognized and utilized in vivo. Here we show that TBL1 and TBLR1, two WD-40 repeat proteins in the corepressor SMRT/N-CoR complexes, are functionally redundant and essential for transcriptional repression by unliganded thyroid hormone receptors (TR) but not essential for transcriptional activation by liganded TR. TBL1 and TBLR1 bind preferentially to hypoacetylated histones H2B and H4 in vitro and have a critical role in targeting the corepressor complexes to chromatin in vivo. We show that targeting SMRT/N-CoR complexes to the deiodinase 1 gene (D1) requires at least two interactions, one between unliganded TR and SMRT/N-CoR and the other between TBL1/TBLR1 and hypoacetylated histones. Neither interaction alone is sufficient for the stable association of the corepressor complexes with the D1 promoter. Our data support a feed-forward working model in which deacetylation exerted by initial unstable recruitment of SMRT/N-CoR complexes via their interaction with unliganded TR generates a histone code that serves to stabilize their own recruitment. Similarly, we find that targeting of the Sin3 complex to pericentric heterochromatin may also follow this model. Our studies provide an in vivo example that a histone code is not read independently but is recognized in the context of other interactions.


2021 ◽  
Vol 22 (19) ◽  
pp. 10822
Author(s):  
Agata Winiarska ◽  
Monika Knysak ◽  
Katarzyna Nabrdalik ◽  
Janusz Gumprecht ◽  
Tomasz Stompór

The incidence of type 2 diabetes (T2D) has been increasing worldwide, and diabetic kidney disease (DKD) remains one of the leading long-term complications of T2D. Several lines of evidence indicate that glucose-lowering agents prevent the onset and progression of DKD in its early stages but are of limited efficacy in later stages of DKD. However, sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor (GLP-1R) antagonists were shown to exert nephroprotective effects in patients with established DKD, i.e., those who had a reduced glomerular filtration rate. These effects cannot be solely attributed to the improved metabolic control of diabetes. In our review, we attempted to discuss the interactions of both groups of agents with inflammation and oxidative stress—the key pathways contributing to organ damage in the course of diabetes. SGLT2i and GLP-1R antagonists attenuate inflammation and oxidative stress in experimental in vitro and in vivo models of DKD in several ways. In addition, we have described experiments showing the same protective mechanisms as found in DKD in non-diabetic kidney injury models as well as in some tissues and organs other than the kidney. The interaction between both drug groups, inflammation and oxidative stress appears to have a universal mechanism of organ protection in diabetes and other diseases.


2022 ◽  
Vol 12 ◽  
Author(s):  
Xiangbing Mao ◽  
Rui Sun ◽  
Qingxiang Wang ◽  
Daiwen Chen ◽  
Bing Yu ◽  
...  

Inflammatory bowel disease (namely, colitis) severely impairs human health. Isoleucine is reported to regulate immune function (such as the production of immunoreactive substances). The aim of this study was to investigate whether l-isoleucine administration might alleviate dextran sulfate sodium (DSS)-induced colitis in rats. In the in vitro trial, IEC-18 cells were treated by 4 mmol/L l-isoleucine for 12 h, which relieved the decrease of cell viability that was induced by TNF-α (10 ng/ml) challenge for 24 h (P <0.05). Then, in the in vivo experiment, a total of 44 Wistar rats were allotted into 2 groups that were fed l-isoleucine-supplemented diet and control diet for 35 d. From 15 to 35 d, half of the rats in the 2 groups drank the 4% DSS-adding water. Average daily gain, average daily feed intake and feed conversion of rats were impaired by DSS challenge (P <0.05). Drinking the DSS-supplementing water also increased disease activity index (DAI) and serum urea nitrogen level (P <0.05), shortened colonic length (P <0.05), impaired colonic enterocyte apoptosis, cell cycle, and the ZO-1 mRNA expression (P <0.05), increased the ratio of CD11c-, CD64-, and CD169-positive cells in colon (P <0.05), and induced extensive ulcer, infiltration of inflammatory cells, and collagenous fiber hyperplasia in colon. However, dietary l-isoleucine supplementation attenuated the negative effect of DSS challenge on growth performance (P <0.05), DAI (P <0.05), colonic length and enterocyte apoptosis (P <0.05), and dysfunction of colonic histology, and downregulated the ratio of CD11c-, CD64-, and CD169-positive cells, pro-inflammation cytokines and the mRNA expression of TLR4, MyD88, and NF-κB in the colon of rats (P <0.05). These results suggest that supplementing l-isoleucine in diet improved the DSS-induced growth stunting and colonic damage in rats, which could be associated with the downregulation of inflammation via regulating TLR4/MyD88/NF-κB pathway in colon.


2019 ◽  
Vol 317 (4) ◽  
pp. F881-F889 ◽  
Author(s):  
Hyung Jung Oh ◽  
Hyewon Oh ◽  
Bo Young Nam ◽  
Je Sung You ◽  
Dong-Ryeol Ryu ◽  
...  

As oxidative stress is one major factor behind contrast-associated acute kidney injury (CA-AKI), we investigated the protective effect of klotho against CA-AKI via the antioxidative effect. In in vitro experiments, cells (NRK-52E) were divided into the following three groups: control, iopamidol, or iopamidol + recombinant klotho (rKL) groups. Moreover, cell viability was measured with the Cell Counting Kit-8 assay, and oxidative stress was examined with 2',7'-dichlorodihydrofluorescein diacetate fluorescence intensity. RT-PCR and Western blot analysis were performed to assess propidium iodide klotho expression, and Bax-to-Bcl-2 and apoptosis ratios were evaluated with annexin V/Hoechst 33342 staining. Furthermore, we knocked down the klotho gene using siRNA to verify the endogenous effect of klotho. In our in vivo experiments, oxidative stress was evaluated with the thiobarbituric acid-reactive substance assay, and apoptosis was evaluated with the Bax-to-Bcl-2 ratio and cleaved caspase-3 immunohistochemistry. Additionally, cell and tissue morphology were investigated with transmission electron microscopy. In both in vitro and in vivo experiments, mRNA and protein expression of klotho significantly decreased in CA-AKI mice compared with control mice, whereas oxidative stress and apoptosis markers were significantly increased in CA-AKI mice. However, rKL supplementation mitigated the elevated apoptotic markers and oxidative stress in the CA-AKI mouse model and improved cell viability. In contrast, oxidative stress and apoptotic markers were more aggravated when the klotho gene was knocked down. Moreover, we found more cytoplasmic vacuoles in the CA-AKI mouse model using transmission electron microscopy but fewer cytoplasmic vacuoles in rKL-supplemented cells. The present study shows that klotho in proximal tubular cells can protect against CA-AKI via an antioxidative effect.


2020 ◽  
Vol 9 (6) ◽  
pp. 734-740
Author(s):  
Yigit Sezer ◽  
Ayse Tarbin Jannuzzi ◽  
Marilyn A Huestis ◽  
Buket Alpertunga

Abstract Background: JWH-018 was the first synthetic cannabinoid introduced as a legal high and the first of the new generation of novel psychoactive substances that flooded worldwide drug markets. JWH-018 was marketed as “spice,” “herbal incense,” or “herbal blend,” as a popular and legal (at the time) alternative to cannabis (marijuana). JWH-018 is a potent synthetic cannabinoid with considerable toxicity associated with its use. JWH-018 has qualitatively similar but quantitatively greater pharmacological effects than cannabis, leading to intoxications and even deaths. The mechanisms of action of the drug’s toxicity require research, and thus, the aim of the present study was to investigate the toxicological profile of JWH-018 in human SH-SY5Y neuronal cells. Methods: SH-SY5Y neuronal cells were exposed to increasing concentrations from 5 to 150 μM JWH-018 over 24 h. Cytotoxicity, DNA damage, the apoptotic/necrotic rate, and oxidative stress were assessed following SH-SY5Y exposure. Results: JWH-018 did not produce a significant decrease in SH-SY5Y cell viability, did not alter apoptotic/necrotic rate, and did not cause genotoxicity in SH-SY5Y cells with 24-h exposure. Glutathione reductase and catalase activities were significantly reduced; however, there was no significant change in glutathione peroxidase activity. Also, JWH-018 treatment significantly decreased glutathione concentrations, significantly increased protein carbonylation, and significantly increased malondialdehyde (MDA) concentrations. For significance, all P < 0.05. Discussion/Conclusion: JWH-018 produced oxidative stress in SH-SY5Y cells that could be an underlying mechanism of JWH-018 neurotoxicity. Additional in vivo animal and human-based studies are needed to confirm our findings.


2019 ◽  
Vol 133 (13) ◽  
pp. 1523-1536 ◽  
Author(s):  
Xiao Sun ◽  
Xiuli Feng ◽  
Dandan Zheng ◽  
Ang Li ◽  
Chunyan Li ◽  
...  

Abstract Cigarette smoke (CS) is the major cause of chronic obstructive pulmonary disease (COPD). CS heightens inflammation, oxidative stress and apoptosis. Ergosterol is the main bioactive ingredient in Cordyceps sinensis (C. sinensis), a traditional medicinal herb for various diseases. The objective of this work was to investigate the effects of ergosterol on anti-inflammatory and antioxidative stress as well as anti-apoptosis in a cigarette smoke extract (CSE)-induced COPD model both in vitro and in vivo. Our results demonstrate that CSE induced inflammatory and oxidative stress and apoptosis with the involvement of the Bcl-2 family proteins via the nuclear factor kappa B (NF-κB)/p65 pathway in both 16HBE cells and Balb/c mice. CSE induced epithelial cell death and increased the expression of nitric oxide (NO), interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), malondialdehyde (MAD) and the apoptosis-related proteins cleaved caspase 3/7/9 and cleaved-poly-(ADP)-ribose polymerase (PARP) both in vitro and in vivo, whereas decreased the levels of superoxide dismutase (SOD) and catalase (CAT). Treatment of 16HBE cells and Balb/c mice with ergosterol inhibited CSE-induced inflammatory and oxidative stress and apoptosis by inhibiting the activation of NF-κB/p65. Ergosterol suppressed apoptosis by inhibiting the expression of the apoptosis-related proteins both in vitro and in vivo. Moreover, the usage of QNZ (an inhibitor of NF-κB) also partly demonstrated that NF-κB/p65 pathway was involved in the ergosterol protective progress. These results show that ergosterol suppressed COPD inflammatory and oxidative stress and apoptosis through the NF-κB/p65 pathway, suggesting that ergosterol may be partially responsible for the therapeutic effects of cultured C. sinensis on COPD patients.


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