The impact of high fat consumption on neurological functions following a traumatic brain injury in rats

Traumatic brain injury (TBI) and obesity are two common conditions in modern society; both can impair neuronal integrity and neurological function. However, it is unclear whether the co-existence of both conditions will worsen outcomes. Thus, in a rat model, we aimed to investigate whether the co-existence of TBI and a high-fat diet (HFD) has an additive effect, leading to more severe neurological impairments, and whether they are related to changes in brain protein markers of oxidative stress, inflammation and synaptic plasticity. Sprague-Dawley rats (female, ~250g) were divided into HFD (43% fat) and chow diet (CD, 17% fat) groups for 6 weeks. Within each dietary group, half underwent a TBI by a weight-drop device, and the other half underwent sham surgery. Short-term memory and sensory function were measured at 24 hours, 1 week, 3 weeks and 6 weeks post-TBI. Brain tissues were harvested at 24 hours and 6 weeks post-TBI and markers of oxidative stress, apoptosis, inflammation, and synaptic plasticity were measured via immunostaining and western blotting. In rats without TBI, HFD increased the presynaptic protein synaptophysin. In rats with TBI, HFD resulted in worsened sensory and memory function, an increase in activated macrophages, and a decrease in the endogenous antioxidant manganese superoxide dismutase. Our findings suggest that the additive effect of HFD and TBI worsens short term memory and sensation deficits, and may be driven by enhanced oxidative stress and inflammation.

Non-Additive Effects of Combined NOX1/4 Inhibition and Calcimimetic Treatment on a Rat Model of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD)

Chronic kidney disease-mineral and bone disorder (CKD-MBD) increases cardiovascular calcification and skeletal fragility in part by increasing systemic oxidative stress and disrupting mineral homeostasis through secondary hyperparathyroidism. We hypothesized that treatments to reduce reactive oxygen species formation and reduce parathyroid hormone (PTH) levels would have additive beneficial effects to prevent cardiovascular calcification and deleterious bone architecture and mechanics before end-stage kidney disease. To test this hypothesis, we treated a naturally progressive model of CKD-MBD, the Cy/+ rat, beginning early in CKD with the NADPH oxidase (NOX1/4) inhibitor GKT-137831 (GKT), the preclinical analogue of the calcimimetic etelcalcetide, KP-2326 (KP), and their combination. The results demonstrated that CKD animals had elevated blood urea nitrogen, PTH, fibroblast growth factor 23 (FGF23), and phosphorus. Treatment with KP reduced PTH levels compared with CKD animals, whereas GKT treatment increased C-terminal FGF23 levels without altering intact FGF23. GKT treatment alone reduced aortic calcification and NOX4 expression but did not alter the oxidative stress marker 8-OHdG in the serum or aorta. KP treatment reduced aortic 8-OHdG and inhibited the ability for GKT to reduce aortic calcification. Treatments did not alter heart calcification or left ventricular mass. In the skeleton, CKD animals had reduced trabecular bone volume fraction and trabecular number with increased trabecular spacing that were not improved with either treatment. The cortical bone was not altered by CKD or by treatments at this early stage of CKD. These results suggest that GKT reduces aortic calcification while KP reduces aortic oxidative stress and reduces PTH, but the combination was not additive. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Serum protein biomarkers of inflammation, oxidative stress, and cerebrovascular and glial injury in concussed Australian football players

Clinical decisions related to sports-related concussion (SRC) are challenging due to the heterogenous nature of SRC symptoms coupled with the current reliance on subjective self-reported symptom measures. Sensitive and objective methods that can diagnose SRC and determine recovery would aid clinical management, and there is evidence that SRC induces changes in circulating protein biomarkers indicative of neuroaxonal injury. However, potential blood biomarkers related to other pathobiological responses linked to SRC are still poorly understood. Therefore, here we analyzed blood samples from concussed (male = 30; female = 9) and non-concussed (male = 74; female = 27) amateur Australian rules football players collected during the pre-season (i.e., baseline), and at 2-, 6-, and 13-days post-SRC to determine time dependent changes in serum levels of biomarkers related to glial (i.e., brain lipid-binding protein, BLBP; phosphoprotein enriched in astrocytes 15) and cerebrovascular injury (i.e., von Willebrand factor, claudin-5), inflammation (i.e., fibrinogen, high mobility group box protein 1), and oxidative stress (i.e., 4-hydroxynoneal). In females, BLBP levels were significantly decreased at 2-days post-SRC compared to their pre-season baseline; however, area under the receiver operating characteristic curve (AUROC) analysis found that BLBP was unable to distinguish between SRC and controls. In males, AUROC analysis revealed a statistically significant change at 2-days post-SRC in the serum levels of 4-hydroxynoneal, however the associated AUROC value (0.6373) indicated little clinical utility for this biomarker in distinguishing SRC from controls. There were no other statistically significant findings. These results indicate that the serum biomarkers tested in this study hold little clinical value in the management of SRC at 2-, 6-, and 13-days post-injury.

Oridonin ameliorates traumatic brain injury-induced neurological damage by improving mitochondrial function and antioxidant capacity and suppressing neuroinflammation through the Nrf2 pathway

Traumatic brain injury (TBI) is a global public health concern, and few effective treatments for its delayed damages are available. Oridonin (Ori) has been recently reported to show a promising neuroprotective efficacy, but its potential therapeutic effect on TBI has not been thoroughly elucidated. TBI mouse models were established and treated with Ori or vehicle 30 minutes post-operation and every 24 hours since then. Impairments in cognitive and motor function and neuropathological changes were evaluated and compared. The therapeutic efficacy and mechanisms of action of Ori were further investigated using animal tissues and cell cultures. Ori restored motor function and cognition following TBI-induced impairment and exerted neuroprotective effects by reducing cerebral edema and cortical lesion volume. Ori increased neuronal survival, ameliorating gliosis and the accumulation of macrophages after injury. It suppressed the increased production of reactive oxygen species, lipid peroxide, and malondialdehyde; and reversed the decrease of mitochondrial membrane potential and adenosine triphosphate content, which was also identified in oxidatively stressed neuronal cultures. Furthermore, Ori inhibited the expression of NLRP3 inflammasome proteins and NLRP3-dependent cytokine IL-1β that can be induced by oxidative stress following TBI. Regarding underlying mechanisms, Ori significantly enhanced expression of key proteins of the Nrf2/HO-1 pathway. Our results demonstrated that Ori effectively improved functional impairments and neuropathological changes in TBI animals. By activating the Nrf2 pathway, it improved mitochondrial function and antioxidant capacity, and suppressed the neuroinflammation induced by oxidative stress. The results therefore suggest Ori as a potent candidate for treating neurological damage after TBI.

Dysfunctional ER-mitochondrion coupling is associated with ER stress-induced apoptosis and neurological deficits in a rodent model of severe head injury

Cellular homeostasis requires critical communications between the endoplasmic reticulum (ER) and mitochondria to maintain the viability of cells. This communication is mediated and maintained by the mitochondria-associated membranes (MAMs) and may be disrupted during acute traumatic brain injury (TBI), leading to structural and functional damages of neurons and supporting cells. To test this hypothesis, we subjected male C57BL/6 mice to severe TBI (sTBI) using a controlled cortical impact (CCI) device. We analyzed the physical ER-mitochondrion contacts in the perilesional cortex using transmission electron microscopy, western blot, and immunofluorescence. We specifically measured changes in the production of reactive oxygen species (ROS) in mitochondria, the unfolded protein response (UPR), the neuroinflammatory response, and ER stress-mediated apoptosis in the traumatic injured cerebral tissue. A modified neurological severity score (mNSS) was used to evaluate neurological function in the sTBI mice. We found that sTBI induced significant reorganizations of MEMs in the cerebral cortex within the first 24 hr post-injury. This ER-mitochondrion coupling was enhanced, reaching its peak level at 6 hrs post-sTBI. This enhanced coupling correlated closely with increases in the expression of the Ca2+ regulatory proteins (IP3R1, VDAC1, GRP75, Sigma-1R), production of ROS, degree of ER stress, levels of UPR, and release of proinflammatory cytokines. Furthermore, the neurological function of sTBI mice was significantly improved by silencing the gene for the ER-mitochondrion tethering factor PACS2, restoring the IP3R1-GRP75-VDAC1 axis of Ca2+ regulation, alleviating mitochondria-derived oxidative stress, suppressing inflammatory response through the PERK/eIF2α/ATF4/CHOP pathway, and inhibiting ER stress and associated apoptosis. These results indicate that dysfunctional ER-mitochondrion coupling might be primarily involved in the neuronal apoptosis and neurological deficits, and modulating the ER-mitochondrion crosstalk might be a novel therapeutic strategy for sTBI.

Silicon Oxynitrophosphide Nanoscale Coating Enhances Antioxidant Marker-Induced Angiogenesis During in vivo Cranial Bone-Defect Healing

Critical-sized bone defects are challenging to heal because of the sudden and large volume of lost bone. Fixative plates are often used to stabilize defects, yet oxidative stress and delayed angiogenesis are contributing factors to poor biocompatibility and delayed bone healing. This study tests the angiogenic and antioxidant properties of amorphous silicon oxynitrophosphide (SiONPx) nanoscale-coating material on endothelial cells to regenerate vascular tissue in vitro and in bone defects. in vitro studies evaluate the effect of silicon oxynitride (SiONx) and two different SiONPx compositions on human endothelial cells exposed to ROS (eg, hydrogen peroxide) that simulates oxidative stress conditions. in vivo studies using adult male Sprague Dawley rats (approximately 450 g) were performed to compare a bare plate, a SiONPx-coated implant plate, and a sham control group using a rat standard-sized calvarial defect. Results from this study showed that plates coated with SiONPx significantly reduced cell death, and enhanced vascular tubule formation and matrix deposition by upregulating angiogenic and antioxidant expression (eg, vascular endothelial growth factor A, angiopoetin-1, superoxide dismutase 1, nuclear factor erythroid 2-related factor 2, and catalase 1). Moreover, endothelial cell markers (CD31) showed a significant tubular structure in the SiONPx coating group compared with an empty and uncoated plate group. This reveals that atomic doping of phosphate into the nanoscale coating of SiONx produced markedly elevated levels of antioxidant and angiogenic markers that enhance vascular tissue regeneration. This study found that SiONPx or SiONx nanoscale-coated materials enhance antioxidant expression, angiogenic marker expression, and reduce ROS levels needed for accelerating vascular tissue regeneration. These results further suggest that SiONPx nanoscale coating could be a promising candidate for titanium plate for rapid and enhanced cranial bone-defect healing. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Absence of Dipeptidyl Peptidase 3 Increases Oxidative Stress and Causes Bone Loss

Controlling oxidative stress through the activation of antioxidant pathways is crucial in bone homeostasis, and impairments of the cellular defense systems involved contribute to the pathogenesis of common skeletal diseases. In this work we focused on the dipeptidyl peptidase 3 (DPP3), a poorly investigated ubiquitous zinc-dependent exopeptidase activating the Keap1-Nrf2 antioxidant pathway. We showed Dpp3 expression in bone and, to understand its role in this compartment, we generated a Dpp3 knockout (KO) mouse model and specifically investigated the skeletal phenotype. Adult Dpp3 KO mice showed a mild growth defect, a significant increase in bone marrow cellularity, and bone loss mainly caused by increased osteoclast activity. Overall, in the mouse model, lack of DPP3 resulted in sustained oxidative stress and in alterations of bone microenvironment favoring the osteoclast compared to the osteoblast lineage. Accordingly, in vitro studies revealed that Dpp3 KO osteoclasts had an inherent increased resorptive activity and ROS production, which on the other hand made them prone to apoptosis. Moreover, absence of DPP3 augmented bone loss after estrogen withdrawal in female mice, further supporting its relevance in the framework of bone pathophysiology. Overall, we show a nonredundant role for DPP3 in the maintenance of bone homeostasis and propose that DPP3 might represent a possible new osteoimmunological player and a marker of human bone loss pathology. © 2019 American Society for Bone and Mineral Research.

Melanocortin 4 Receptor Activation Attenuates Mitochondrial Dysfunction in Skeletal Muscle of Diabetic Rats

A previous study has confirmed that the central melanocortin system was able to mediate skeletal muscle AMP-activated protein kinase (AMPK) activation in mice fed a high-fat diet, while activation of the AMPK signaling pathway significantly induced mitochondrial biogenesis. Our hypothesis was that melanocortin 4 receptor (MC4R) was involved in the development of skeletal muscle injury in diabetic rats. In this study, we treated diabetic rats intracerebroventricularly with MC4R agonist R027-3225 or antagonist SHU9119, respectively. Then, we measured the production of reactive oxygen species (ROS), the levels of malondialdehyde (MDA) and glutathione (GSH), the mitochondrial DNA (mtDNA) content and mitochondrial biogenesis, and the protein levels of p-AMPK, AMPK, peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α), sirtuin 1 (SIRT1), and manganese superoxide dismutase (MnSOD) in the skeletal muscle of diabetic rats. The results showed that there was significant skeletal muscle injury in the diabetic rats along with serious oxidative stress and decreased mitochondrial biogenesis. Treatment with R027-3225 reduced oxidative stress and induced mitochondrial biogenesis in skeletal muscle, and also activated the AMPK-SIRT1-PGC-1α signaling pathway. However, diabetic rats injected with MC4R antagonist SHU9119 showed an aggravated oxidative stress and mitochondrial dysfunction in skeletal muscle. In conclusion, our results revealed that MC4R activation was able to attenuate oxidative stress and mitochondrial dysfunction in skeletal muscle induced by diabetes partially through activating the AMPK-SIRT1-PGC-1α signaling pathway. J. Cell. Biochem. 118: 4072-4079, 2017. © 2017 Wiley Periodicals, Inc.

PGC-1α in Melanoma: A Key Factor for Antioxidant Response and Mitochondrial Function

Melanocortin 1 receptor (MC1R) and BRAF are common mutations in melanoma. Through different pathways, they each regulate the expression of PGC-1α, which is a key factor in the regulation of mitochondrial biogenesis and the antioxidant response. Our aim was to study the importance of the different regulatory characteristics of MC1R and BRAF on the pathways they regulate in melanoma. For this purpose, ROS production, levels of gene expression and enzymatic activities were analyzed in HBL and MeWo, with wild-type MC1R and BRAF, and A375 cells with mutant MC1R and BRAF. HBL cells showed a functional MC1R-PGC-1α pathway and exhibited the lowest ROS production, probably because of a better mitochondrial pool and the presence of UCP2. On the other hand, MeWo cells showed elevated levels of PGC-1α but also high ROS production, similar to the A375 cells, along with an activated antioxidant response and significantly low levels of UCP2. Finally, A375 cells are mutant for BRAF, and thus showed low levels of PGC-1α. Consequently, A375 cells exhibited poor mitochondrial biogenesis and function, and no antioxidant response. These results show the importance of the activation of the MC1R-PGC-1α pathway for mitochondrial biogenesis and function in melanoma development, as well as BRAF for the antioxidant response regulated by PGC-1α. J. Cell. Biochem. 118: 4404-4413, 2017. © 2017 Wiley Periodicals, Inc.

Resveratrol Ameliorates Palmitate-Induced Inflammation in Skeletal Muscle Cells by Attenuating Oxidative Stress and JNK/NF-κB Pathway in a SIRT1-Independent Mechanism

Resveratrol has been shown to exert anti-inflammatory and anti-oxidant effects in a variety of cell types, however, its role in prevention of inflammatory responses mediated by palmitate in skeletal muscle cells remains unexplored. In the present study, we investigated the effects of resveratrol on palmitate-induced inflammation and elucidated the underlying mechanisms in skeletal muscle cells. The results showed that palmitate significantly enhanced TNF-α and IL-6 mRNA expression and protein secretion from C2C12 cells at 12, 24, and 36 h treatments. Increased expression of cytokines was accompanied by an enhanced phosphorylation of JNK, P38, ERK1/2, and IKKα/IKKβ. In addition, JNK and P38 inhibitors could significantly attenuate palmitate-induced mRNA expression of TNF-α and IL-6, respectively, whereas NF-κB inhibitor reduced the expression of both cytokines in palmitate-treated cells. Resveratrol pretreatment significantly prevented palmitate-induced TNF-α and IL-6 mRNA expression and protein secretion in C2C12 cells. Importantly, pre-treatment of the cells with resveratrol completely abrogated the phosphorylation of ERK1/2, JNK, and IKKα/IKKβ in palmitate treated cells. The protection from palmitate-induced inflammation by resveratrol was accompanied by a decrease in the generation of reactive oxygen species (ROS). N-acetyl cysteine (NAC), a known scavenger of ROS, could protect palmitate-induced expression of TNF-α and IL-6. Furthermore, inhibition of SIRT1 by shRNA or sirtinol demonstrated that the anti-inflammatory effect of resveratrol in muscle cells is mediated through a SIRT1-independent mechanism. Taken together, these findings suggest that resveratrol may represent a promising therapy for prevention of inflammation in skeletal muscle cells. J. Cell. Biochem. 118: 2654-2663, 2017. © 2017 Wiley Periodicals, Inc.

Mechanism of Generation of Oxidative Stress and Pathophysiology of Type 2 Diabetes Mellitus: How Are They Interlinked?

Oxidative stress has been considered as a major hallmark for the pathogenesis and development of type 2 diabetes mellitus (T2DM), but still it is debatable whether it is a mere aggregation of inflammatory-induced responses or clinical entity that underlies with various pathophysiological factors. In this regard, the latest studies have shown the increasing trends for the involvement of reactive oxygen species (ROS) and oxidative stress in the pathogenesis and development of T2DM. ROS are highly reactive species and almost all cellular components are chemically changed due to the influence of ROS that ultimately results in the production of lipid peroxidation. Lipid peroxidation is a major causative factor for the development of oxidative stress that leads to overt T2DM and its associated micro- and macro-vascular complications. In this article, we have briefly described the role of various causative factors, transcriptional and metabolic pathways which are responsible to increase the production of oxidative stress, a most pivotal factor for the pathogenesis and development of T2DM. Therefore, we conclude that measurement of oxidative stress biomarkers may be one of the optional tool for the diagnosis and prediction of T2DM. Moreover, the key findings described in this article also provides a new conceptual framework for forthcoming investigations on the role of oxidative stress in pathogenesis of T2DM and drug discovery. J. Cell. Biochem. 118: 3577-3585, 2017. © 2017 Wiley Periodicals, Inc.

All-Trans Retinoic Acid Ameliorates Arsenic-Induced Oxidative Stress and Apoptosis in the Rat Uterus by Modulating MAPK Signaling Proteins

Exposure to arsenic leads to inhibition of the anti-oxidant defense mechanism of the body. Reactive oxygen species generated in response to arsenic causes reproductive failures in exposed females and also acts as an inducer of apoptosis. As a prospective remedial agent, all-trans retinoic acid (ATRA) was assessed for reversing arsenic-induced oxidative stress and apoptosis. Rats exposed to arsenic for 28 days were allowed to recover naturally or were treated simultaneously with ATRA for 28 days or up to 56 days. Production of H₂ O₂ was detected using 2',7'-dichlorfluorescein diacetate (DCFCA) by flow cytometry. Catalase, superoxide dismutase, glutathione, ALT, and AST were estimated by biochemical assays and Western blot analyses. Detection of apoptosis was performed using annexin V-FITC/propidium iodide. Expressions of p53, p21, cleaved caspase 3, JNK/pJNK, and ERK/pERK levels were estimated using Western blot analysis. Elemental arsenic deposition in the rat uterus and liver was estimated by atomic absorption spectrophotometry. Our results confirmed that ATRA ameliorated sodium arsenite-induced ROS generation, restored redox balance, and prevented apoptosis. Concomitant recovery was observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Tissue arsenic deposition was significantly reduced in the uterus upon continuous ATRA treatment. The results revealed that ATRA reversed arsenic-induced free radical generation, activated the anti-oxidant defence system, and subsequently repressed p53-dependent apoptosis through inhibition of the MAPK signaling components. J. Cell. Biochem. 118: 3796-3809, 2017. © 2017 Wiley Periodicals, Inc.

Endocrine Imbalance Associated With Proteome Changes in Diabetes

The dynamics of cellular metabolism involves rapid interactions between proteins and nucleic acids, proteins and proteins, and signaling. These involve the interactions with respect to the sulfur bond, noncovalent electrostatic interactions, protein structure stabilization and protein-ligand binding, weak electrostatic interactions in proteins, oxygen radicals that initiate a change in conformation and a chain of events. We review a development in molecular medicine that is a very promising work in progress. We also review the current and future research methods involving mitochondria. Long-term effects of diabetes include glycation of proteins, for example, glycohemoglobin (HbA1c), increased risk of cardiovascular diseases, atherosclerosis, retinopathy, nephropathy, and neurological dysfunctions. Tissues are exposed to significant quantities of highly reactive chemical species including nitric oxide ^• NO and reactive oxygen species ROS over months to years, to an extent generated by mitochondrial activities. The reactions of ^• NO can be broadly discussed with reference to three main processes which control their fate in biological systems: (1) diffusion and intra-cellular consumption; (2) autooxidation to form nitrous anhydride N₂ O₃ ; and (3) reaction with superoxide O2^• - to form peroxynitrite ONOO-. Reactive nitrogen species produced by macrophages and neutrophils in the interstitial space, with emphasis on ^• NO, N₂ O₃ , ONOO-, and nitrogen dioxide radicals ^• NO₂ generate protein and DNA damage. Serum thiol (-SH) groups act as an important extracellular scavenger of peroxides and are therefore helpful in protecting the surrounding tissues. The events described here are a homeostatic endocrine imbalance that is associated with proteostasis. The advances we have seen in untangling this web of interactions are sure to continue at a breathtaking pace. J. Cell. Biochem. 118: 3569-3576, 2017. © 2017 Wiley Periodicals, Inc.

HX-1171, a Novel Nrf2 Activator, Induces NQO1 and HMOX1 Expression

HX-1171 (1-O-hexyl-2,3,5-trimethylhydroquinone) is a novel synthesized vitamin E derivative, which reportedly has positive effects on various diseases and conditions, such as liver fibrosis, hepatic cirrhosis, and cancer. In this study, we analyzed the transcriptional activity induced by HX-1171. Results from reverse transcription polymerase chain reaction and promoter assays reveal that HX-1171 increased the expression of NQO1 and HMOX1, encoding antioxidant-related enzymes, in A549 human lung epithelial cells. The activity of nuclear factor-E2-related factor (Nrf2), a key transcriptional factor for antioxidative enzymes, was examined in HX-1171-treated cells. Confocal microscopy and Western blotting showed that HX-1171 effectively induced the nuclear translocation and transcriptional activity of Nrf2. We conclude that HX-1171, a novel Nrf2 activator, may be a promising therapeutic agent for oxidative stress-induced diseases. J. Cell. Biochem. 118: 3372-3380, 2017. © 2017 Wiley Periodicals, Inc.

BMI-1 Mediates Estrogen-Deficiency-Induced Bone Loss by Inhibiting Reactive Oxygen Species Accumulation and T Cell Activation

Previous studies have shown that estrogen regulates bone homeostasis through regulatory effects on oxidative stress. However, it is unclear how estrogen deficiency triggers reactive oxygen species (ROS) accumulation. Recent studies provide evidence that the B lymphoma Mo-MLV insertion region 1 (BMI-1) plays a critical role in protection against oxidative stress and that this gene is directly regulated by estrogen via estrogen receptor (ER) at the transcriptional level. In this study, ovariectomized mice were given drinking water with/without antioxidant N-acetyl-cysteine (NAC, 1 mg/mL) supplementation, and compared with each other and with sham mice. Results showed that ovariectomy resulted in bone loss with increased osteoclast surface, increased ROS levels, T cell activation, and increased TNF and RANKL levels in serum and in CD4 T cells; NAC supplementation largely prevented these alterations. BMI-1 expression levels were dramatically downregulated in CD4 T cells from ovariectomized mice. We supplemented drinking water to BMI-1-deficient mice with/without NAC and compared them with each other and with wild-type (WT) mice. We found that BMI-1 deficiency mimicked alterations observed in ovariectomy whereas NAC supplementation reversed all alterations induced by BMI-1 deficiency. Because T cells are critical in mediating ovariectomy-induced bone loss, we further assessed whether BMI-1 overexpression in lymphocytes can protect against estrogen deficiency-induced osteoclastogenesis and bone loss by inhibiting oxidative stress, T cell activation, and RANKL production. When WT and Eμ-BMI-1 transgenic mice with BMI-1 specifically overexpressed in lymphocytes were ovariectomized and compared with each other and with WT sham mice, we found that BMI-1 overexpression in lymphocytes clearly reversed all alterations induced by ovariectomy. Results from this study indicate that estrogen deficiency downregulates BMI-1 and subsequently increases ROS, T cell activation, and RANKL production in T cells, thus enhancing osteoclastogenesis and accelerating bone loss. This study clarifies a novel mechanism regulating estrogen deficiency-induced bone loss. © 2016 American Society for Bone and Mineral Research.

Hypermethylation: Causes and Consequences in Skeletal Muscle Myopathy

A detrimental consequence of hypermethylation is hyperhomocysteinemia (HHcy), that causes oxidative stress, inflammation, and matrix degradation, which leads to multi-pathology in different organs. Although, it is well known that hypermethylation leads to overall gene silencing and hypomethylation leads to overall gene activation, the role of such process in skeletal muscle dysfunction during HHcy condition is unclear. In this study, we emphasized the multiple mechanisms including epigenetic alteration by which HHcy causes skeletal muscle myopathy. This review also highlights possible role of methylation, histone modification, and RNA interference in skeletal muscle dysfunction during HHcy condition and potential therapeutic molecules, putative challenges, and methodologies to deal with HHcy mediated skeletal muscle dysfunction. We also highlighted that B vitamins (mainly B12 and B6), with folic acid supplementation, could be useful as an adjuvant therapy to reverse these consequences associated with this HHcy conditions in skeletal muscle. However, we would recommend to further study involving long-term trials could help to assess efficacy of the use of these therapeutic agents. J. Cell. Biochem. 118: 2108-2117, 2017. © 2017 Wiley Periodicals, Inc.

Oxidative Stress and Amyloid Toxicity: Insights From Yeast

Alzheimer's disease is the most common neurodegenerative disorder. One of the factors that promotes neurodegeneration is the accumulation of senile plaques formed by Aβ peptide. In this paper, it was analyzed that if oxidative stress is cause or consequence of amyloid cascade and the role of antioxidant defense system in this process, using S. cerevisiae (with a multicopy plasmid containing the Aβ1-42 sequence) as experimental model. Cells grown on glycerol were more tolerant than when grown on glucose, strengthening the role of the antioxidant defense system against Aβ accumulation. Antioxidant defense deficiency did not change the pattern of amyloid aggregation. On the other hand, the presence of Aβ increased the level of intracellular oxidation and induced the activity of catalase, superoxide dismutase, and aconitase. Peroxissomal catalase deficient cells (Δcta1), were more sensitive to Aβ toxicity than the wild type strain, while mitochondrial superoxide dismutase (Sod2) deficient cells displayed the highest frequency of petites. Besides, Aβ alters the oxygen consumption and the activity of complex III and IV. Taken together, our results point out that the Aβ toxicity mechanism involves an oxidative stress induction by increasing ROS production into the mitochondria, where Cta1 and Sod2 play a crucial role in the regulation of the redox balance. J. Cell. Biochem. 118: 1442-1452, 2017. © 2016 Wiley Periodicals, Inc.

Interleukin-3 Prevents Cellular Death Induced by Oxidative Stress in HEK293 Cells

Interleukin-3 (IL-3) is a well-characterized growth factor in hematopoietic cells, but it is also expressed in other cell types with poorly described functions. Many studies have provided evidence that IL-3 plays an important role in cell survival. We have previously shown that IL-3 is able to increase glucose uptake in HEK293 cells, suggesting that this factor requires sustained glucose metabolism to promote cell survival. In this study, we demonstrate that IL-3 contributes to cell survival under oxidative stress, a prominent feature in the pathophysiology of cancer, diabetes, and neurodegenerative diseases, as well as in the aging process. Our results suggest a molecular mechanism that involves signaling pathways mediated by PI-3k/Akt and Erk. Altogether, these findings show an important role for IL-3 in supporting the viability of non-hematopoietic systems. J. Cell. Biochem. 118: 1330-1340, 2017. © 2016 Wiley Periodicals, Inc.

Aging and Oxidative Stress Decrease Pineal Elongation Factor 2: In Vivo Protective Effect of Melatonin in Young Rats Treated With Cumene Hydroperoxide

We studied the alterations of Elongation Factor 2 (eEF2) in the pineal gland of aged rats as well as the possible protective role of exogenous melatonin on these changes in young rats treated with cumene hydroperoxide (CH), a compound that promotes lipid peroxidation and inhibits protein synthesis. The study was performed using male Wistar rats of 3 (control), 12, and 24 months and 3-month-old rats treated with CH, melatonin, and CH plus melatonin. We found that pineal eEF-2 is affected by aging and CH, these changes being prevented by exogenous melatonin in the case of CH-treated rats. The proteomic studies show that many other proteins are affected by aging and oxidative stress in the pineal gland. The results suggest that one of the possible mechanisms underlying pineal gland dysfunction during aging is the effect of lipid peroxidation on eEF-2, which is a key component of protein synthesis machinery. J. Cell. Biochem. 118: 182-190, 2017. © 2016 Wiley Periodicals, Inc.

Anti-Inflammatory and Anti-Oxidant Effects of p-Chloro-phenyl-selenoesterol on TNBS-Induced Inflammatory Bowel Disease in Mice

This study aims to investigate the protective effect of p-chloro-phenyl-selenoesterol [PCS; 0,2 mg/kg; 10 ml/kg i.g.) in colitis induced by 2,4,6-trinitrobenzene sulfonic acid [TNBS; 2 mg/100 µl 50% ethanol; intrarectally) in mice. Several parameters including weight, length, histological analyses determination, thiobarbituric acid reactive species, reactive species levels, superoxide dismutase, catalase, and myeloperoxidase (MPO) activity of colon were evaluated. The serum levels of tumor necrosis factor alpha [TNF-α) and interleukin 6 [IL-6) were also assessed. Treatment with PCS reduced the clinical and histopathologic severity of TNBS-induced colitis, characterized by colon length reduction and increased colon weight and microscopic intestinal inflammation. The therapeutic effects of PCS in this model were associated with significant decrease in proinflammatory cytokines TNF-α and IL-6 and decrease in MPO activity. Furthermore, combined with improvements in inflammatory parameters, treatment with the PCS was able to decrease oxidative stress and to prevent the decrease in antioxidant defenses in animals with TNBS-induced colitis. This finding suggests that PCS can improve experimental colitis in mice and it could be a potential therapeutic agent for the treatment of patients with IBD. J. Cell. Biochem. 118: 709-717, 2017. © 2016 Wiley Periodicals, Inc.

Lentiviral Vector-Mediated FoxO1 Overexpression Inhibits Extracellular Matrix Protein Secretion Under High Glucose Conditions in Mesangial Cells

Diabetic nephropathy is characterized by inordinate secretion of extracellular matrix (ECM) proteins from mesangial cells (MCs), which is tightly associated with excessive activation of TGF-β signaling. The forkhead transcription factor O1 (FoxO1) protects mesangial cells from hyperglycemia-induced oxidative stress, which may be involved in ameliorating the redundant secretion of ECM proteins under high glucose conditions. Here, we reported that high glucose elevated the level of p-Akt to attenuate endogenous FoxO1 bioactivities in MCs, accompanied with decreases in the mRNA expressions of catalase (CAT) and superoxide dismutase 2 (SOD2). Meanwhile, the expressions of major ECM proteins-FN and Col I-increased under high glucose conditions, in consistent with the activation of TGF-β/Smad signaling. By contrast, overexpression of nucleus-localized FoxO1 (insensitive to Akt phosphorylation) directly up-regulated the expressions of anti-oxidative enzymes, accompanied with inactivation of TGF-β/Smad3 pathway, as well as decreases of extracellular matrix proteins. Moreover, similar to those MCs overexpressed of nucleus-localized FoxO1 in high glucose conditions, MCs with down-regulation of FoxO1 by small interference-RNA under normal glucose conditions showed increased FN level and activated TGF-β/Smad3 pathway. Our findings link the anti-oxidative activity of FoxO1 and the TGF-β-induced secretion of ECM proteins, indicating the novel role of FoxO1 in protecting MCs under high glucose conditions.

Evidence for Pipecolate Oxidase in Mediating Protection Against Hydrogen Peroxide Stress

Pipecolate, an intermediate of the lysine catabolic pathway, is oxidized to Δ¹ -piperideine-6-carboxylate (P6C) by the flavoenzyme l-pipecolate oxidase (PIPOX). P6C spontaneously hydrolyzes to generate α-aminoadipate semialdehyde, which is then converted into α-aminoadipate acid by α-aminoadipatesemialdehyde dehydrogenase. l-pipecolate was previously reported to protect mammalian cells against oxidative stress. Here, we examined whether PIPOX is involved in the mechanism of pipecolate stress protection. Knockdown of PIPOX by small interference RNA abolished pipecolate protection against hydrogen peroxide-induced cell death in HEK293 cells suggesting a critical role for PIPOX. Subcellular fractionation analysis showed that PIPOX is localized in the mitochondria of HEK293 cells consistent with its role in lysine catabolism. Signaling pathways potentially involved in pipecolate protection were explored by treating cells with small molecule inhibitors. Inhibition of both mTORC1 and mTORC2 kinase complexes or inhibition of Akt kinase alone blocked pipecolate protection suggesting the involvement of these signaling pathways. Phosphorylation of the Akt downstream target, forkhead transcription factor O3 (FoxO3), was also significantly increased in cells treated with pipecolate, further implicating Akt in the protective mechanism and revealing FoxO3 inhibition as a potentially key step. The results presented here demonstrate that pipecolate metabolism can influence cell signaling during oxidative stress to promote cell survival and suggest that the mechanism of pipecolate protection parallels that of proline, which is also metabolized in the mitochondria. J. Cell. Biochem. 118: 1678-1688, 2017. © 2016 Wiley Periodicals, Inc.

Castanea sativa Mill. Bark Extract Protects U-373 MG Cells and Rat Brain Slices Against Ischemia and Reperfusion Injury

Ischemic brain injury is one of the most important causes of death worldwide. The use of one-drug-multi-target agents based on natural compounds is a promising therapeutic option for cerebral ischemia due to their pleiotropic properties. This study assessed the neuroprotective properties of Castanea sativa Mill. bark extract (ENC) in human astrocytoma U-373 MG cells subjected to oxygen-glucose deprivation and reperfusion and rat cortical slices subjected to ischemia-like conditions or treated with glutamate or hydrogen peroxide. Neuroprotective effects were determined by assessing cells or slices viability (MTT assay), ROS formation (DCFH-DA assay), apoptosis (sub G0/G1 peak), nuclear fragmentation and chromatin condensation (DAPI staining) as well as changes in lysosomes and mitochondria morphology (Acridine Orange and Rhodamine123 staining, respectively). ENC treatment before injury on U-373 MG cells (5-50 μg/ml) and cortical slices (50-100 μg/ml) provided neuroprotection, while lower or higher concentrations (100 μg/ml U-373 MG cells, 200 μg/ml brain slices) were ineffective. ENC addition during reperfusion or after the injury was not found to be effective. The results suggest that ENC might hold potential as preventive neuroprotective agent, and indicate the importance of further studies exploring its mechanism of action. J. Cell. Biochem. 118: 839-850, 2017. © 2016 Wiley Periodicals, Inc.

Eotaxin Augments Calcification in Vascular Smooth Muscle Cells

Calcification of atherosclerotic plaques in elderly patients represents a potent risk marker of cardiovascular events. Plasma analyses of patients with or without calcified plaques reveal significant differences in chemokines, particularly eotaxin, which escalates with increased calcification. We therefore, hypothesize that eotaxin in circulation augments calcification of vascular smooth muscle cells (VSMCs) possibly via oxidative stress in the vasculature. We observe that eotaxin increases the rate of calcification significantly in VSMCs as evidenced by increased alkaline phosphatase activity, calcium deposition, and osteogenic marker expression. In addition, eotaxin promotes proliferation in VSMCs and triggers oxidative stress in a NADPH oxidase dependent manner. These primary novel observations support our proposition that in the vasculature eotaxin augments mineralization. Our findings suggest that eotaxin may represent a potential therapeutic target for prevention of cardiovascular complications in the elderly. J. Cell. Biochem. 118: 647-654, 2017. © 2016 Wiley Periodicals, Inc.

SIRT3 Silencing Sensitizes Breast Cancer Cells to Cytotoxic Treatments Through an Increment in ROS Production

SIRT3, the major deacetylase in mitochondria, plays a crucial role modulating ROS production and scavenging by regulating key proteins implicated in mitochondrial turnover and in antioxidant defenses. Therefore, SIRT3 could confer resistance to chemotherapy-induced oxidative stress, leading to a lower ROS production and a higher cell survival. Our aim was to analyze whether SIRT3 silencing in breast cancer cells through a specific siRNA could increase oxidative stress and thus compromise the antioxidant response, resulting in a sensitization of the cells to cisplatin (CDDP) or tamoxifen (TAM). For this purpose, we studied cell viability, ROS production, apoptosis and autophagy in MCF-7 and T47D cell lines treated with these cytotoxic compounds, these either alone, or in combination with SIRT3 silencing. Moreover, protein levels regulated by SIRT3 were also examined and survival curves were analyzed to study the importance of SIRT3 expression for the overall survival of breast cancer patients. When SIRT3 was silenced and combined with cytotoxic treatments, cell viability was highly decreased, and was accompanied by a significant increase in ROS production. While TAM treatment increased autophagic cell death, CDDP significantly triggered apoptosis, whereas SIRT3 silencing produced an enhancement of these two action mechanisms. SIRT3 knockdown also affected PGC-1α and TFAM (mitochondrial biogenesis), and MnSOD and IDH₂ (antioxidant defenses) protein levels. Finally, survival curves showed that higher SIRT3 expression is correlated to a poorer prognosis for patients with grade 3 breast cancer. In conclusion, SIRT3 could be a therapeutic target for breast cancer, improving the effectiveness of CDDP and TAM treatments. J. Cell. Biochem. 118: 397-406, 2017. © 2016 Wiley Periodicals, Inc.

MicroRNA-155 Regulates ROS Production, NO Generation, Apoptosis and Multiple Functions of Human Brain Microvessel Endothelial Cells Under Physiological and Pathological Conditions

The microRNA-155 (miR155) regulates various functions of cells. Dysfunction or injury of endothelial cells (ECs) plays an important role in the pathogenesis of various vascular diseases. In this study, we investigated the role and potential mechanisms of miR155 in human brain microvessel endothelial cells (HBMECs) under physiological and pathological conditions. We detected the effects of miR155 silencing on ROS production, NO generation, apoptosis and functions of HBMECs at basal and in response to oxidized low density lipoprotein (ox-LDL). Western blot and q-PCR were used for analyzing the gene expression of epidermal growth factor receptor (EGFR)/extracellular regulated protein kinases (ERK)/p38 mitogen-activated protein kinase (p38 MAPK), phosphatidylinositol-3-kinase (PI3K) and serine/threonine kinase(Akt), activated caspase-3, and intercellular adhesion molecule-1 (ICAM-1). Results showed that under both basal and challenge situations: (1) Silencing of miR155 decreased apoptosis and reactive oxygen species (ROS) production of HBMECs, whereas, promoted nitric oxide (NO) generation. (2) Silencing of miR155 increased the proliferation, migration, and tube formation ability of HBMECs, while decreased cell adhesion ability. (3) Gene expression analyses showed that EGFR/ERK/p38 MAPK and PI3K/Akt were increased and that activated caspase-3 and ICAM-1 mRNA were decreased after knockdown of miR155. In conclusion, knockdown of miR155 could modulate ROS production, NO generation, apoptosis and function of HBMECs via regulating diverse gene expression, such as caspase-3, ICAM-1 and EGFR/ERK/p38 MAPK and PI3K/Akt pathways.

Gut microbiota associated with HIV infection is significantly enriched in bacteria tolerant to oxygen

Objectives

Gut microbiota modifications occurring during HIV infection have recently been associated with inflammation and microbial translocation. However, discrepancies between studies justified a comprehensive analysis performed on a large sample size.

Design and methods

In a case–control study, next-generation sequencing of the 16S rRNA gene was applied to the faecal microbiota of 31 HIV-infected patients, of whom 18 were treated with antiretroviral treatment (ART), compared with 27 healthy controls. 21 sera samples from HIV-infected patients and 7 sera samples from control participants were used to test the presence of 25 markers of inflammation and/or immune activation.

Results

Diversity was significantly reduced in HIV individuals when compared with controls and was not restored in the ART group. The relative abundance of several members of Ruminococcaceae such as Faecalibacterium prausnitzii was critically less abundant in the HIV-infected group and inversely correlated with inflammation/immune activation markers. Members of Enterobacteriaceae and Enterococcaceae were found to be enriched and positively correlated with these markers. There were significantly more aerotolerant species enriched in HIV samples (42/52 species, 80.8%) when compared with the control group (14/87 species, 16.1%; χ² test, p<10⁻⁵, conditional maximum-likelihood estimate (CMLE) OR=21.9).

Conclusions

Imbalance between aerobic and anaerobic flora observed in HIV faecal microbiota could be a consequence of the gut impairment classically observed in HIV infection via the production of oxygen. Overgrowth of proinflammatory aerobic species during HIV infection raises the question of antioxidant supplementation, such as vitamin C, E or N-acetylcysteine.

Gcn5 Modulates the Cellular Response to Oxidative Stress and Histone Deacetylase Inhibition

To identify chemical genetic interactions underlying the mechanism of action of histone deacetylase inhibitors (HDACi) a yeast deletion library was screened for hypersensitive deletion mutants that confer increased sensitivity to the HDACi, CG-1521. The screen demonstrated that loss of GCN5 or deletion of components of the Gcn5 histone acetyltransferase (HAT) complex, SAGA, sensitizes yeast to CG-1521-induced cell death. Expression profiling after CG-1521 treatment reveals increased expression of genes involved in metabolism and oxidative stress response, and oxidative stress response mutants are hypersensitive to CG-1521 treatment. Accumulation of reactive oxygen species and increased cell death are enhanced in the gcn5Δ deletion mutant, and are abrogated by anti-oxidants, indicating a central role of oxidative stress in CG-1521-induced cell death. In human cell lines, siRNA mediated knockdown of GCN5 or PCAF, or chemical inhibition of GCN5 enzymatic activity, increases the sensitivity to CG-1521 and SAHA. These data suggest that the combination of HDAC and GCN5/PCAF inhibitors can be used for cancer treatment.

Fortification of alcoholic beverages (12% v/v) with tea (Camellia sinensis) reduces harmful effects of alcohol ingestion and metabolism in mouse model

Background

An animal model was used to study the health benefits inherent in tea fortified alcoholic beverages fed to laboratory mice.

Objectives

An investigation of the effects of tea fortified alcoholic beverages 12% alcohol (v/v) on antioxidant capacity and liver dysfunction indicators in white Swiss mice including packed cell volume (PCV), albumin, total protein, alkaline phosphatase (ALP) and glutathione (GSH) was carried out.

Methods

Plain, black, green and purple tea fortified alcohols were developed with varying tea concentrations of 1, 2 and 4 g/250 mL in 12% v/v. Control alcoholic beverages without teas were also developed. A permit (number IRC/13/12) was obtained for the animal research from the National Museums of Kenya, Institute of Primate Research prior to the start of the study. Alcoholic beverages were orally administered every 2 days for 4 weeks at 1 mL per mouse, and thereafter animals were euthanised and liver and blood samples harvested for analyses. Assays on body weight (bwt), packed cell volume (PCV) albumin, total protein, ALP and GSH were performed. Results were statistically analysed using GraphPad statistical package and significant differences of means of various treatments determined.

Results

Consumption of tea fortified alcohols significantly decreased (p=0.0001) bwt at 0.32–9.58% and PCV at 5.56–22.75% for all teas. Total protein in serum and liver of mice fed on different tea fortified alcohols ranged between 6.26 and 9.24 g/dL and 2.14 and 4.02 g/dL, respectively. Albumin, ALP and GSH range was 0.92–2.88 µg/L, 314.98–473.80 µg/L and 17.88–28.62 µM, respectively. Fortification of alcoholic beverages lowered liver ALP, replenished antioxidants and increased liver albumin, improving the nutritional status of the mice.

Conclusions

The findings demonstrate tea's hepatoprotective mechanisms against alcohol-induced injury through promotion of endogenous antioxidants. The beneficial effects of tea in the fortified alcoholic beverages could be used to develop safer alcoholic beverages.

Leptin Induces Oxidative Stress Through Activation of NADPH Oxidase in Renal Tubular Cells: Antioxidant Effect of L-Carnitine

Leptin is a protein involved in the regulation of food intake and in the immune and inflammatory responses, among other functions. Evidences demonstrate that obesity is directly associated with high levels of leptin, suggesting that leptin may directly link obesity with the elevated cardiovascular and renal risk associated with increased body weight. Adverse effects of leptin include oxidative stress mediated by activation of NADPH oxidase. The aim of this study was to evaluate the effect of L-carnitine (LC) in rat renal epithelial cells (NRK-52E) exposed to leptin in order to generate a state of oxidative stress characteristic of obesity. Leptin increased superoxide anion (O2 (•) -) generation from NADPH oxidase (via PI3 K/Akt pathway), NOX2 expression and nitrotyrosine levels. On the other hand, NOX4 expression and hydrogen peroxide (H2 O2 ) levels diminished after leptin treatment. Furthermore, the expression of antioxidant enzymes, catalase, and superoxide dismutase, was altered by leptin, and an increase in the mRNA expression of pro-inflammatory factors was also found in leptin-treated cells. LC restored all changes induced by leptin to those levels found in untreated cells. In conclusion, stimulation of NRK-52E cells with leptin induced a state of oxidative stress and inflammation that could be reversed by preincubation with LC. Interestingly, LC induced an upregulation of NOX4 and restored the release of its product, hydrogen peroxide, which suggests a protective role of NOX4 against leptin-induced renal damage. J. Cell. Biochem. 117: 2281-2288, 2016. © 2016 Wiley Periodicals, Inc.

Human Umbilical Cord Wharton's Jelly Stem Cell Conditioned Medium Induces Tumoricidal Effects on Lymphoma Cells Through Hydrogen Peroxide Mediation

Several groups have reported that human umbilical cord Wharton's jelly stem cells (hWJSCs) possess unique tumoricidal properties against many cancers. However, the exact mechanisms as to how hWJSCs inhibit tumor growth are not known. Recent evidence suggests that exposure of cancer cells to high hydrogen peroxide (H2 O2 ) levels from H2 O2 -releasing drugs causes their death. We therefore explored whether the tumoricidal effect of hWJSCs on lymphoma cells was mediated via H2 O2 . We first exposed lymphoma cells to six different molecular weight cut-off (MWCO) concentrates of hWJSC-conditioned medium (hWJSC-CM) (3, 5, 10, 30, 50, 100 kDa) for 48 h. Since, the 3 kDa-MWCO concentrate showed the greatest cell inhibition we then investigated whether the tumoricidal effect of the specific 3 kDa-MWCO concentrate on two different lymphoma cell lines (Ramos and Toledo) was mediated via accumulation of H2 O2 . We used a battery of assays (MTT, propidium iodide, mitochondria membrane potential, apoptosis, cell cycle, oxidative stress enzymes, hydrogen peroxide, mitochondrial superoxide, hydroxyl radical, peroxynitrile anion, and lipid peroxidation) to test this mechanism. The hWJSC-CM-3 kDa MWCO concentrate significantly decreased cell viability and mitochondrial membrane potential and increased cell death and apoptosis in both lymphoma cell lines. There were significant increases in superoxide dismutase with concomitant decreases in glutathione peroxidase, catalase, and thioredoxin peroxidase activities. H2 O2 levels, mitochondrial superoxide, hydroxyl radical, peroxynitrile anion, and lipid peroxidation were also significantly increased in both lymphoma cell lines. The results suggested that the hWJSC-CM-3 kDa MWCO concentrate regulates cellular H2 O2 leading to a tumoricidal effect and may thus be a promising anti-lymphoma agent. J. Cell. Biochem. 117: 2045-2055, 2016. © 2016 Wiley Periodicals, Inc.

Expression of cFLIPL Determines the Basal Interaction of Bcl-2 With Beclin-1 and Regulates p53 Dependent Ubiquitination of Beclin-1 During Autophagic Stress

Autophagy and apoptosis are two different physiological processes, which is required for the maintenance of cellular homeostasis. The apoptosis associated proteins such as Bcl-2 and p53 have a close association with autophagic proteins HMGB1 and Beclin-1 to modulate autophagic signaling. We demonstrate here the involvement of anti-apoptotic protein cFLIPL in the regulation of autophagy during cellular stress. We found that ectopic expression of cFLIPL decreases the sensitivity of HEK 293T cells against rapamycin and H2 O2 induced autophagic stress. Notably, the selective knockdown of cFLIPL augments autophagic stress in the cells accompanied with JNK1 activation and p53 dependent ubiquitination of Beclin-1. However, re-expression of cFLIPL in cFLIP knockdown cells restores autophagic equilibrium collectively with reversible effects on JNK1 and Beclin-1 integrity. The co-immunoprecipitation analysis suggests that cFLIPL is essential to maintain the canonical interaction of Bcl-2 with Beclin-1 to regulate autophagic stress and cell death. Altogether, our findings suggest that expression of cFLIPL regulates the basal interaction of Bcl-2 with Beclin-1 and substantiates p53 dependent ubiquitination of Beclin-1 during autophagic stress to determine the fate of cell death or survival. J. Cell. Biochem. 117: 1757-1768, 2016. © 2015 Wiley Periodicals, Inc.

Glutathione peroxidase 4 is reversibly induced by HCV to control lipid peroxidation and to increase virion infectivity

OBJECTIVE

Inflammation and oxidative stress drive disease progression in chronic hepatitis C (CHC) towards hepatocellular carcinoma. HCV is known to increase intracellular levels of reactive oxygen species (ROS), but how it eliminates ROS is less well known. The role of the ROS scavenger glutathione peroxidase 4 (GPx4), induced by HCV, in the viral life cycle was analysed.

DESIGN

The study was performed using a replicative in vitro HCV infection model and liver biopsies derived from two different CHC patient cohorts.

RESULTS

A screen for HCV-induced peroxide scavengers identified GPx4 as a host factor required for HCV infection. The physiological role of GPx4 is the elimination of lipid peroxides from membranes or lipoproteins. GPx4-silencing reduced the specific infectivity of HCV by up to 10-fold. Loss of infectivity correlated with 70% reduced fusogenic activity of virions in liposome fusion assays. NS5A was identified as the protein that mediates GPx4 induction in a phosphatidylinositol-3-kinase-dependent manner. Levels of GPx4 mRNA were found increased in vitro and in CHC compared with control liver biopsies. Upon successful viral eradication, GPx4 transcript levels returned to baseline in vitro and also in the liver of patients.

CONCLUSIONS

HCV induces oxidative stress but controls it tightly by inducing ROS scavengers. Among these, GPx4 plays an essential role in the HCV life cycle. Modulating oxidative stress in CHC by specifically targeting GPx4 may lower specific infectivity of virions and prevent hepatocarcinogenesis, especially in patients who remain difficult to be treated in the new era of interferon-free regimens.

Antiviral Action of Diphenyl Diselenide on Herpes Simplex Virus 2 Infection in Female BALB/c Mice

Diphenyl diselenide, (PhSe)2 , is an organoselenium compound with pharmacological actions mostly related to antioxidant and anti-inflammatory properties. The study investigated its antiviral and virucidal actions against herpes simplex virus 2 (HSV-2) infection in vitro and in a vaginal infection model in mice. The plaque reduction assay indicated that (PhSe)2 showed virucidal and antiviral actions reducing infectivity in 70.8% and 47%, respectively. The antiviral action of (PhSe)2 against HSV-2 vaginal infection was performed by infecting mice (10(5)  PFU/ml(-1) ) at day 6. The treatment with (PhSe)2 (5 mg/kg/day, intragastric [i.g.]) followed 5 days before and for more 5 days after infection. The extravaginal lesion score was evaluated from days 6 to 10. At day 11, animals were killed, and histological evaluation, determination of viral load, and TNF-α and IFN-γ levels were performed in supernatants of homogenized vaginal tissue. The levels of reactive species (RS), protein carbonyl, non-protein thiols (NPSH), nitrate/nitrite (NOx), and malondialdehyde (MDA), and the activities of myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) were determined. (PhSe)2 reduced the histological damage, extravaginal lesion scores, the viral load of vaginal tissue, and the activity of MPO, but increased the levels of TNF-α, IFN-γ. (PhSe)2 attenuated the increase of RS, MDA, NOx levels and the activity of GR caused by infection. (PhSe)2 also attenuated the reduction of NPSH content and the inhibition of CAT, SOD, and GPx activities. The antiviral action of (PhSe)2 against HSV-2 infection was related to its immunomodulatory, antioxidant, and anti-inflammatory properties. J. Cell. Biochem. 117: 1638-1648, 2016. © 2015 Wiley Periodicals, Inc.

A phenolic acid phenethyl urea derivative protects against irradiation-induced osteoblast damage by modulating intracellular redox state

Because irradiation may cause osteoradionecrosis, antioxidant supplementation is often used to suppress irradiation-mediated injury. This study examined whether a synthetic phenethyl urea compound, (E)-1-(3,4-dihydroxyphenethyl)-3-(3,4-dihydroxystyryl)urea (DPDS-U), prevents irradiation-mediated cellular damage in MC3T3-E1 osteoblastic cells. A relatively high dose of irradiation (>4 Gy) decreased cell viability and proliferation and induced DNA damage and cell cycle arrest at the G(2)/M phase with the attendant increase of cyclin B1. Irradiation with 8 Gy induced intracellular reactive oxygen species (ROS) production and lipid peroxidation, and reduced glutathione content and superoxide dismutase activity in the cells. These events were significantly suppressed by treatment with 200 µM DPDS-U or 5 mM N-acetyl cysteine (NAC). DPDS-U or irradiation alone significantly increased heme oxygenase-1 (HO-1) expression and nuclear factor E2 p45-related factor-2 (Nrf2) nuclear translocation. Interestingly, pretreatment with DPDS-U facilitated irradiation-induced activation of the Nrf2/HO-1 pathway. The potential of DPDS-U to mediate HO-1 induction and protect against irradiation-mediated cellular damage was almost completely attenuated by transient transfection with Nrf2-specific siRNA or treatment with a pharmacological HO-1 inhibitor, zinc protoporphyrin IX. Additional experiments revealed that DPDS-U induced a radioprotective mechanism that differs from that induced by NAC through activation of Nrf2/HO-1 signaling. Collectively, our data suggest that DPDS-U-induced radioprotection is due to its dual function as an antioxidant to remove directly excessive intracellular ROS and as a prooxidant to stimulate intracellular redox-sensitive survival signal.

Bark Extract in Human Neuroblastoma Cells Subjected to Oxidative Stress

One of the major features of neurodegenerative disease is the selective vulnerability of different neuronal populations that are affected in a progressive and often stereotyped manner. Despite the susceptible neuronal population varies between diseases, oxidative stress is implicated as the major pathogenic process in all of them. Natural Extract of Castanea sativa Mill. bark (ENC), recently characterized in its phenolic composition, acts as antioxidant and cardioprotective agent. Its neuroprotettive properties, however, have never been investigated. The aim of this study was to assess neuroprotection of ENC in in vitro models of oxidative-stress-mediate injury. Human neuroblastoma SH-SY5Y cells treated with glutamate (50 mM for 24 h) or hydrogen peroxide (25 μM for 1 h followed by 24 with medium) were used. The results showed that the addition of ENC (1-50 μg/ml) to cell medium before the neuronal damage provided neuroprotection in both experimental models used, while its addition after the injury was ineffective. In conclusion, the present results suggest that ENC could be a valuable support as dietary supplement, combining beneficial preventive neuroprotettive effects with a high antioxidant activity.

Preserving neural retina through re-emerging herbal interventions

Eye related diseases such as glaucoma, diabetic retinopathy, cataract, conjunctivitis are very common worldwide. With the current scenario India will be among the top five countries in the number of glaucoma cases. Limited discovery of successful drugs for the treatment of such diseases led scientists to look towards the use of conventional sources for treatment. Herbal extracts from Ayurveda have remained an important part of treatment regime in many parts of world even today. For this reason, local herbs possessing curative properties are still being used by local inhabitants due to its anti-inflammatory and antioxidant properties. Because retinal damage involves alterations in oxidative enzymes, blood flow changes and increase in apoptotic signals, herbal extracts are being tested for their ability to moderate antioxidant machinery and trigger neuroprotective pathways. The present review summarizes some of such herbal extracts which have been tested for their neuroprotective role in eye related diseases. The active components that exert neuroprotective effects have also been discussed along with possible mechanisms of action.

Therapeutic targeting of GSK3β enhances the Nrf2 antioxidant response and confers hepatic cytoprotection in hepatitis C

OBJECTIVE

Impaired adaptive response to oxidative injuries is a fundamental mechanism central to the pathogenesis of chronic hepatitis C (CHC). Glycogen synthase kinase (GSK) 3β is an indispensable regulator of the oxidative stress response. However, the exact role of GSK3β in CHC is uncertain and was examined.

DESIGN

GSK3β and Nrf2 signalling pathways were examined in JFH1 HCV infected Huh7.5.1 hepatocytes, and also in liver biopsy specimens from CHC patients.

RESULTS

HCV infection elicited prominent Nrf2 antioxidant response in hepatocytes, marked by elevated expression of the Nrf2-dependent molecule haem oxygenase-1 and subsequent protection from apoptotic cell death. Inhibitory phosphorylation of GSK3β seems to be essential and sufficient for HCV-induced Nrf2 response. Mechanistically, GSK3β associated and physically interacted with Nrf2 in hepatocytes. In silico analysis revealed that Nrf2 encompasses multiple GSK3β phosphorylation consensus motifs, denoting Nrf2 as a cognate substrate of GSK3β. In the presence of TGFβ1, the HCV-induced GSK3β phosphorylation was blunted via a protein phosphatase 1-dependent mechanism and the cytoprotective Nrf2 response drastically impaired. This effect was counteracted by lithium, a selective inhibitor of GSK3β. In liver biopsy specimens from CHC patients, the expression of phosphorylated GSK3β positively correlated with Nrf2 expression and was inversely associated with the degree of liver injury. Moreover, CHC patients who received long-term lithium carbonate therapy primarily for concomitant psychiatric disorders exhibited much less liver injury, associated with enhanced hepatic expression of Nrf2.

CONCLUSIONS

Inhibition of GSK3β exerts hepatoprotection in CHC possibly through its direct regulation of Nrf2 antioxidant response.

Association between global biomarkers of oxidative stress and hip fracture in postmenopausal women: a prospective study

Human studies suggest that oxidative stress is a risk factor for osteoporosis, but its relationship with fracture risk is poorly understood. The purpose of the present study was to investigate the association between biomarkers of oxidative stress and hip fracture in postmenopausal women. We conducted a prospective study in the Nurses' Health Study among 996 women aged 60 years or older at baseline blood collection in 1989-1990. Plasma fluorescent oxidation products (FlOPs) were measured at three excitation/emission wavelengths (360/420 nm named as FlOP_360; 320/420 nm named as FlOP_320; and 400/475 nm named as FlOP_400). FlOPs are generated from many different pathways (lipid, protein, and DNA) and reflect a global oxidation burden. FlOP assay is 10-100 times more sensitive than measurement of malondialdehyde. We used Cox proportional hazards regression model to investigate the association between baseline plasma FlOPs and the risk of hip fracture, adjusting for multiple hip fracture risk factors such as age, history of osteoporosis, history of hypertension, prior fracture, and smoking status. Forty-four hip fractures (4.4%) were identified during the follow-up (maximum = 23 years). In the multivariable model, the hazard ratios (HRs) of hip fracture in the second and third tertiles of FlOP_320 were 2.11 (95% confidence interval [CI] = 0.88-5.10) and 2.67 (95% CI = 1.14-6.27), respectively, in comparison with the lowest tertile, and the risk increased linearly with increasing FlOP_320 (p for trend = 0.021). Neither FlOP_360 nor FlOP_400 was significantly associated with risk of hip fracture (tertile 3 versus tertile 1: HR = 0.70, 95% CI = 0.32-1.54, p for trend = 0.386 for FlOP_360; and HR = 0.88, 95% CI = 0.40-1.96, p for trend = 0.900 for FlOP_400). In this prospective study, higher plasma FlOP_320 was an independent risk factor for hip fracture. Our results need further confirmation.

Bazedoxifene blocks AGEs-RAGE-induced superoxide generation and MCP-1 level in endothelial cells

Advanced glycation endproducts (AGEs) and their receptor (RAGE) play a role in vascular complications in diabetes. We have previously shown that 17β-estradiol at 10 nmol/l, a nearly identical plasma concentration to that during mid-pregnancy, up-regulates RAGE expression in endothelial cells. The finding might suggest the involvement of 17β-estradiol in the deterioration of vascular complications in diabetes during pregnancy. However, the effects of the selective estrogen receptor modulator, bazedoxifene, on oxidative and inflammatory reactions in AGEs-exposed endothelial cells remain unknown. In this study, we addressed the issue. Ten nmol/l 17β-estradiol increased RAGE and monocyte chemoattractant protein-1 (MCP-1) gene and protein expression in human umbilical vein endothelial cells (HUVECs), both of which were blocked by 10 nmol/l bazedoxifene. Bazedoxifene at 10 nmol/l also significantly inhibited the AGEs-induced superoxide generation, RAGE and MCP-1 gene and protein expression in HUVECs. The present study suggests that blockade of the AGEs-RAGE axis by bazedoxifene might be a novel therapeutic target for preventing vascular damage in diabetes, especially in postmenopausal women.

Soybean concentrated extract counteracts oxidative stress in the uterus of rats

OBJECTIVE

To evaluate the effects of soy isoflavone extract in the pro-oxidant/antioxidant balance in the uterus of ovariectomized rats.

METHODS

Twenty 3-month-old adult female Wistar rats were divided into four equal groups: GI: sham-operated (estrous phase); GII: control ovariectomized rats; GIII: ovariectomized rats treated with genistein (50 μg/kg/day) by gavage; GIV: ovariectomized rats subcutaneously treated with estrogen (10 μg/kg/day). After 30 consecutive days of treatment, the rats were euthanized and the uterus removed. The distal thirds of the uterine horns were processed for histomorphometric analyses of endometrial and myometrial thicknesses and glandular area. Other regions of the uteri were kept in liquid nitrogen and subsequently processed for analysis of reactive species quantification (DCF), total antioxidant capacity (TAC) and lipid oxidation status (TBARS). Data were statistically analyzed by one-way ANOVA, complemented by the Tukey-Kramer test (p < 0.05).

RESULTS

GII and GIII exhibited lower endometrial thickness, glandular area and myometrial thickness than GI and GIV, while a higher myometrial thickness was observed in GIV compared with the other groups. Moreover, the isoflavone-treated group showed lower DCF and TBARS compared to GII, and also an improvement of TAC compared to GI and GIV. Despite the significant decrease in TBARS, no significant difference in DCF nor a decrease in TAC were observed in GIV when compared to GII.

CONCLUSION

Our data show that isoflavones improve antioxidant status and counteract oxidative stress, without promoting a trophic effect in the uterus of rats.

Cytoplasmic reactive oxygen species and SOD1 regulate bone mass during mechanical unloading

Oxidative stress contributes to the pathogenesis of age-related diseases as well as bone fragility. Our previous study demonstrated that copper/zinc superoxide dismutase (Sod1)-deficient mice exhibit the induction of intracellular reactive oxygen species (ROS) and bone fragility resulting from low-turnover bone loss and impaired collagen cross-linking (Nojiri et al. J Bone Miner Res. 2011;26:2682-94). Mechanical stress also plays an important role in the maintenance of homeostasis in bone tissue. However, the molecular links between oxidative and mechanical stresses in bone tissue have not been fully elucidated. We herein report that mechanical unloading significantly increased intracellular ROS production and the specific upregulation of Sod1 in bone tissue in a tail-suspension experiment. We also reveal that Sod1 loss exacerbated bone loss via reduced osteoblastic abilities during mechanical unloading. Interestingly, we found that the administration of an antioxidant, vitamin C, significantly attenuated bone loss during unloading. These results indicate that mechanical unloading, in part, regulates bone mass via intracellular ROS generation and the Sod1 expression, suggesting that activating Sod1 may be a preventive strategy for ameliorating mechanical unloading-induced bone loss.

Etanercept improves lipid profile and oxidative stress measures in patients with juvenile idiopathic arthritis

OBJECTIVE

To investigate the effect of 1-year treatment with the anti-tumor necrosis factor-α (TNF-α) drug etanercept on lipid profile and oxidative stress in children and adolescents with juvenile idiopathic arthritis (JIA).

METHODS

Thirty children with JIA (22 females; mean age 12.3 ± SD 5.7 yrs), all eligible for anti-TNF-α treatment, were assessed at baseline and after 6- and 12-month treatment with etanercept. Disease activity was determined using the Juvenile Arthritis Disease Activity Score (JADAS). Blood samples were drawn to measure the acute-phase reactants C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), lipids, and the proinflammatory cytokines TNF-α, interleukin-1β (IL-1β), IL-6 and interferon-γ. To measure the oxidative stress marker 8-iso-prostaglandin F2α, 24-h urine samples were collected.

RESULTS

Inflammatory indicators (CRP and ESR) and JADAS scores improved significantly after 1 year of etanercept treatment (all p < 0.001). Proinflammatory cytokines showed significant reduction during the study period (all p < 0.001). Similar reductions were detected in total cholesterol (p < 0.001), low-density lipoprotein cholesterol (p = 0.04), and triglycerides (p < 0.001), whereas no significant change was found in high-density lipoprotein cholesterol. No side effects were observed during the treatment period.

CONCLUSION

This study shows for the first time that anti-TNF-α therapy for JIA is associated not only with a beneficial effect on clinical disease activity and inflammatory indexes, but also with improved lipid profile and oxidative stress. These findings suggest that TNF-α blockers might reduce atherosclerotic risk in children with JIA.

Effect of antioxidants on the incidence of wound infection in burn patients

Background. Thermal injury causes the destruction of the physical skin barrier that normally protects the body from invasion by micro-organisms and induces an immunocompromised state that predisposes burn patients to infection, sepsis, and multiple organ failure. Reactive oxygen species contribute to burn-mediated immune suppression, and as the use of antioxidants has a positive effect on immune function, this may reduce the incidence of wound infection and related complications in burn patients. Patients and methods. One hundred and eighty burn patients of either sex and different ages, suffering from burns of varying percentage, were involved in the study. They were allocated to six groups: A, B, C, D, E, and F, each of 30 patients. Groups B, C, D, E, and F were treated with antioxidants (vitamins E and C, zinc sulphate, allopurinol, melatonin, and N-acetylcysteine, respectively) while group A was treated without antioxidants, according to our hospital policy. Thirty healthy subjects (group G) were also involved in the study as a control group for comparison. In each group, serum malondialdehyde and serum glutathione levels, microbiological values, healing time, and the mortality rate were measured using standard methods. Results. Administering antioxidants to burn patients produced significant improvements in the parameters studied compared with burn patients not given antioxidants. Conclusion. The study clearly showed the beneficial effect of antioxidants in the treatment of burn patients, as evidenced by the reduced incidence of wound infection and the shortening of healing time, in addition to the lower mortality rate. It is therefore recommended to add antioxidants to the treatment list of burn patients.

Burns, endothelial dysfunction, and oxidative stress: the role of antioxidants

Background. Burns cause a systemic inflammatory response, endothelial dysfunction, and increased microvascular permeability which results in oedema being formed; these effects are probably the result of a complex interplay between the direct effects of heat on the microcirculation and the action of chemical mediators, including reactive oxygen species. The use of antioxidants can reduce these changes, which are considered a promised step in burns management. Patients and methods. Forty-eight burn patients of either sex and with varying burns percentages were involved in the study. They were each allocated to one of four groups: A, B, C, and D, each group composed of 12 patients. Groups B, C, and D were treated with antioxidants: allopurinol, melatonin, and N-acetylcysteine respectively, while group A was treated according to normal hospital policy, without antioxidants; 12 healthy subjects (group E) served as a control group for comparison. In each group, serum malondialdehyde and serum glutathione levels were measured and liver and kidney function tests were performed, as well as microalbuminuria tests, using standard methods. Results. The administration of antioxidants to burns patients produced significant improvements in the parameters studied compared to group A parameters (no antioxidant given). Conclusion. This study clearly demonstrates the role of reactive oxygen species in endothelial dysfunction occurring in burn patients and the beneficial effect of antioxidants in reducing it, as shown by the reduced microalbuminuria and reduced resuscitation fluid in antioxidant-treated burn patients; the study also supports newly emerging evidence regarding the use of microalbuminuria as an indicator for endothelial dysfunction in burn patients.