scholarly journals Peroxiredoxin 4 (PRDX4): Its Critical In Vivo Roles in Animal Models of Metabolic Syndrome Using Our Unique PRDX4 Transgenic Mice

Author(s):  
Sohsuke Yamada ◽  
Xin Guo ◽  
Akihide Tanimoto

The peroxiredoxin (PRDX) family, a new family of proteins with a pivotal antioxidative function, is ubiquitously synthesized and abundantly identified in various organisms. In contrast to the intracellular localization of other family members (PRDX1/2/3/5/6), PRDX4 is the only known secretory form and protects against oxidative damage by scavenging reactive oxygen species in both the intracellular (especially the endoplasmic reticulum) compartments and the extracellular space. Recently, we generated unique human PRDX4 (hPRDX4) transgenic (Tg) mice on a C57BL/6J background and investigated the critical and diverse protective roles of PRDX4 against diabetes mellitus, atherosclerosis, insulin resistance, and nonalcoholic fatty liver disease (NAFLD) as well as evaluated its role in the intestinal function in various animal models. Our published data have shown that PRDX4 helps prevent the progression of metabolic syndrome by reducing local and systemic oxidative stress and synergistically suppressing steatosis, inflammatory reactions, and/or apoptotic activity. These observations suggest that Tg mice may be a useful animal model for studying the relevance of oxidative stress on inflammation and the dysregulation of lipid/bile acid/glucose metabolism upon the progression of human metabolic syndrome, and that specific accelerators of PRDX4 may be useful as therapeutic agents for ameliorating various chronic inflammatory diseases.

2021 ◽  
Vol 22 (4) ◽  
pp. 1514 ◽  
Author(s):  
Akihiro Yachie

Since Yachie et al. reported the first description of human heme oxygenase (HO)-1 deficiency more than 20 years ago, few additional human cases have been reported in the literature. A detailed analysis of the first human case of HO-1 deficiency revealed that HO-1 is involved in the protection of multiple tissues and organs from oxidative stress and excessive inflammatory reactions, through the release of multiple molecules with anti-oxidative stress and anti-inflammatory functions. HO-1 production is induced in vivo within selected cell types, including renal tubular epithelium, hepatic Kupffer cells, vascular endothelium, and monocytes/macrophages, suggesting that HO-1 plays critical roles in these cells. In vivo and in vitro studies have indicated that impaired HO-1 production results in progressive monocyte dysfunction, unregulated macrophage activation and endothelial cell dysfunction, leading to catastrophic systemic inflammatory response syndrome. Data from reported human cases of HO-1 deficiency and numerous studies using animal models suggest that HO-1 plays critical roles in various clinical settings involving excessive oxidative stress and inflammation. In this regard, therapy to induce HO-1 production by pharmacological intervention represents a promising novel strategy to control inflammatory diseases.


2020 ◽  
Vol 26 (22) ◽  
pp. 2610-2619 ◽  
Author(s):  
Tarique Hussain ◽  
Ghulam Murtaza ◽  
Huansheng Yang ◽  
Muhammad S. Kalhoro ◽  
Dildar H. Kalhoro

Background: Inflammation is a complex response of the host defense system to different internal and external stimuli. It is believed that persistent inflammation may lead to chronic inflammatory diseases such as, inflammatory bowel disease, neurological and cardiovascular diseases. Oxidative stress is the main factor responsible for the augmentation of inflammation via various molecular pathways. Therefore, alleviating oxidative stress is effective a therapeutic option against chronic inflammatory diseases. Methods: This review article extends the knowledge of the regulatory mechanisms of flavonoids targeting inflammatory pathways in chronic diseases, which would be the best approach for the development of suitable therapeutic agents against chronic diseases. Results: Since the inflammatory response is initiated by numerous signaling molecules like NF-κB, MAPK, and Arachidonic acid pathways, their encountering function can be evaluated with the activation of Nrf2 pathway, a promising approach to inhibit/prevent chronic inflammatory diseases by flavonoids. Over the last few decades, flavonoids drew much attention as a potent alternative therapeutic agent. Recent clinical evidence has shown significant impacts of flavonoids on chronic diseases in different in-vivo and in-vitro models. Conclusion: Flavonoid compounds can interact with chronic inflammatory diseases at the cellular level and modulate the response of protein pathways. A promising approach is needed to overlook suitable alternative compounds providing more therapeutic efficacy and exerting fewer side effects than commercially available antiinflammatory drugs.


2019 ◽  
Vol 2 (4) ◽  
pp. e201900308 ◽  
Author(s):  
Shun Nagashima ◽  
Keisuke Takeda ◽  
Nobuhiko Ohno ◽  
Satoshi Ishido ◽  
Motohide Aoki ◽  
...  

Mitochondrial abnormalities are associated with developmental disorders, although a causal relationship remains largely unknown. Here, we report that increased oxidative stress in neurons by deletion of mitochondrial ubiquitin ligase MITOL causes a potential neuroinflammation including aberrant astrogliosis and microglial activation, indicating that mitochondrial abnormalities might confer a risk for inflammatory diseases in brain such as psychiatric disorders. A role of MITOL in both mitochondrial dynamics and ER-mitochondria tethering prompted us to characterize three-dimensional structures of mitochondria in vivo. In MITOL-deficient neurons, we observed a significant reduction in the ER-mitochondria contact sites, which might lead to perturbation of phospholipids transfer, consequently reduce cardiolipin biogenesis. We also found that branched large mitochondria disappeared by deletion of MITOL. These morphological abnormalities of mitochondria resulted in enhanced oxidative stress in brain, which led to astrogliosis and microglial activation partly causing abnormal behavior. In conclusion, the reduced ER-mitochondria tethering and excessive mitochondrial fission may trigger neuroinflammation through oxidative stress.


2021 ◽  
Author(s):  
Arnold N. Onyango

Unhealthy diets, such as those high in saturated fat and sugar accelerate the development of non-communicable diseases. The metabolic syndrome is a conglomeration of disorders such as abdominal obesity, hypertension, impaired glucose regulation and dyslipidemia, which increases the risk for diabetes and cardiovascular disease. The prevalence of the metabolic syndrome is increasing globally, and dietary interventions may help to reverse this trend. A good understanding of its pathophysiological mechanisms is needed for the proper design of such interventions. This chapter discusses how lipid peroxidation is associated with the development of this syndrome, mainly through the formation of bioactive aldehydes, such as 4-hydroxy-2-nonenal, malondialdehyde, acrolein and glyoxal, which modify biomolecules to induce cellular dysfunction, including the enhancement of oxidative stress and inflammatory signaling. It gives a current understanding of the mechanisms of formation of these aldehydes and how dietary components such as saturated fatty acids promote oxidative stress, leading to lipid oxidation. It also outlines mechanisms, apart from free radical scavenging and singlet oxygen quenching, by which various dietary constituents prevent oxidative stress and lipid oxidation in vivo.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Marcos C. Carreira ◽  
Andrea G. Izquierdo ◽  
Maria Amil ◽  
Felipe F. Casanueva ◽  
Ana B. Crujeiras

Sirt6 is a member of the sirtuin family involved in physiological and pathological processes including aging, cancer, obesity, diabetes, and energy metabolism. This study is aimed at evaluating the relationship between liver SIRT6 gene expression and the oxidative stress network depending on adiposity levels in Zucker rats, an animal model of metabolic syndrome. We observed that liver-specific SIRT6 expression is reduced in an in vivo model of spontaneous obesity and metabolic syndrome. We also observed that SIRT6 expression in the liver is positively associated with SIRT1 and GST-M2 expressions, two proteins involved in antioxidant protection pathways and inversely related to body weight and plasmatic oxidative status. Interestingly, the SIRT6 expression is upregulated after energy restriction-induced weight loss concomitantly with an improvement in oxidative stress markers. These results suggest that SIRT6 may be a potential therapeutic target for the treatment of obesity and associated metabolic disorders, such as liver disease.


2020 ◽  
Vol 10 (23) ◽  
pp. 8698
Author(s):  
Hae Lim Kim ◽  
Hae Jin Lee ◽  
Dong-Ryung Lee ◽  
Bong-Keun Choi ◽  
Seung Hwan Yang

Osteoarthritis (OA) is a general joint illness caused by the destruction of joint cartilage, and is common in the population of old people. Its occurrence is related to inflammatory reactions and cartilage degradation. AyuFlex® is an aqueous extract of Terminalia chebula fruit, and T. chebula has been utilized extensively in several traditional oriental medications for the management of diverse diseases. Pre-clinical and clinical research has shown its antioxidant and anti-inflammatory effectiveness. Nevertheless, the mechanism underlying the anti-arthritic effects of AyuFlex® remains unclear. In the current research, we proposed the ameliorating effects of AyuFlex® with respect to the incidence of OA and described the latent signalization in interleukin (IL)-1β-treated chondrocytes and MIA-incurred OA in a rat model. In vitro, AyuFlex® decreased oxidative stress and induction of pro-inflammatory cytokines and mediators as well as matrix metalloproteinases (MMPs), while also increasing the levels of collagen synthesis-related proteins. Mechanistically, we identified that AyuFlex® disrupted nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) activation via the inhibition of NF-κB p65 and extracellular regulated protein kinase (ERK) phosphorylation. The ameliorating effects of AyuFlex® were also observed in vivo. AyuFlex® significantly inhibited the MIA-incurred increase in OA symptoms such as oxidative stress, cartilage damage, and changes in cytokines and MMPs revelation in arthrodial cartilage. Therefore, our results suggest that AyuFlex® attenuates OA progression in vivo, indicating that AyuFlex® can be suggested as an excellent therapeutic remedy for the care of OA.


1979 ◽  
Vol 92 (1) ◽  
pp. 105-118 ◽  
Author(s):  
A. Haeberli ◽  
H. Engler ◽  
C. von Grünigen ◽  
H. Kohler ◽  
H. Studer

ABSTRACT in this paper additional information on low molecular weight, soluble, intrathyroidal iodocompounds with slow metabolic rate is provided. These compounds have previously been localized autoradiographically within the follicular cells. Radioiodide was administered to rats on a normal iodine intake (6–7 μg/day) for 80 days to approach isotopic equilibration of the intrathyroidal iodine with the dietary radioiodide. When the isotope was omitted from the diet the intrathyroidal radioiodine was released with an apparent half-life of approximately 12 days. When the individual soluble components carrying radioiodine were analyzed after separation on Sephadex G-200, different apparent half-lives were found, the half-life of thyroglobulin (Tgb) being roughly 10 days and that of the low molecular weight iodocomounds being in the order of 60 to 100 days or more. In addition to the soluble low molecular weight iodocompounds, the radioactivity in the particulate fraction increased by 100 % during the tracer washout when compared to Tgb and the total soluble fraction. The soluble slow turnover iodocompounds contained a higher percentage of carbohydrate and total iodine than Tgb, while the relative amounts of each sugar analyzed (hexoses, fucose, hexosamine and sialic acid) were close to those in Tgb. Sephadex G-25 chromatography of the low molecular weight iodocompounds obtained after Sephadex G-200 separation resulted in the separation of 4 peaks. Two peaks identified as iodopeptides could be further analyzed. The carbohydrate composition of these peptides was similar to that of 2 glycopeptides obtained after in vitro enzymatic hydrolysis of purified Tgb with pronase. Slow equilibration with radioiodine, long apparent intrathyroidal half-life and carbohydrate content similar to that of Tgb, taken together with previously published data on intracellular localization of soluble intrathyroidal iodocompounds, suggest that the low molecular weight iodocompounds are products of in vivo hydrolysis of engulfed Tgb droplets.


2006 ◽  
Vol 5 (7) ◽  
pp. 1081-1090 ◽  
Author(s):  
Susan M. Kraemer ◽  
David A. Goldstrohm ◽  
Ann Berger ◽  
Susan Hankey ◽  
Sherry A. Rovinsky ◽  
...  

ABSTRACT To characterize the role of the general transcription factor TFIIA in the regulation of gene expression by RNA polymerase II, we examined the transcriptional profiles of TFIIA mutants of Saccharomyces cerevisiae using DNA microarrays. Whole-genome expression profiles were determined for three different mutants with mutations in the gene coding for the small subunit of TFIIA, TOA2. Depending on the particular mutant strain, approximately 11 to 27% of the expressed genes exhibit altered message levels. A search for common motifs in the upstream regions of the pool of genes decreased in all three mutants yielded the binding site for Yap1, the transcription factor that regulates the response to oxidative stress. Consistent with a TFIIA-Yap1 connection, the TFIIA mutants are unable to grow under conditions that require the oxidative stress response. Underexpression of Yap1-regulated genes in the TFIIA mutant strains is not the result of decreased expression of Yap1 protein, since immunoblot analysis indicates similar amounts of Yap1 in the wild-type and mutant strains. In addition, intracellular localization studies indicate that both the wild-type and mutant strains localize Yap1 indistinguishably in response to oxidative stress. As such, the decrease in transcription of Yap1-dependent genes in the TFIIA mutant strains appears to reflect a compromised interaction between Yap1 and TFIIA. This hypothesis is supported by the observations that Yap1 and TFIIA interact both in vivo and in vitro. Taken together, these studies demonstrate a dependence of Yap1 on TFIIA function and highlight a new role for TFIIA in the cellular mechanism of defense against reactive oxygen species.


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