Persistent Pain Is Dependent on Spinal Mitochondrial Antioxidant Levels

Reactive oxygen species (ROS) scavengers have been shown to relieve persistent pain; however, the mechanism is not clearly understood. Superoxide produced from mitochondrial oxidative phosphorylation is considered the major source of ROS in neurons during excitation where mitochondrial superoxide levels are normally controlled by superoxide dismutase (SOD-2). The present study hypothesizes that capsaicin-induced secondary hyperalgesia is a consequence of superoxide build-up in spinal dorsal horn neurons and SOD-2 is a major determinant. To test this hypothesis, the spinal levels of SOD-2 activity, inactivated SOD-2 proteins, and mitochondrial superoxide were measured and correlated to the levels of capsaicin-induced secondary hyperalgesia in mice with and without SOD-2 manipulations. The data suggest that superoxide accumulation is a culprit in the abnormal sensory processing in the spinal cord in capsaicin-induced secondary hyperalgesia. Our studies also support the notion that SOD-2 nitration is a critical mechanism that maintains elevated superoxide levels in the spinal cord after capsaicin treatment. Finally, our findings suggest a therapeutic potential for the manipulation of spinal SOD-2 activity in pain conditions.This work was supported by National Institutes of Health Grants R01 NS31680 and P01 NS11255

Protective effect of Camellia oleifera Abel. on silica-induced pulmonary fibrosis in rats

Background:  Camellia oleifera Abel. belongs to the family Theaceae and genus Camellia. It is commonly cultivated in southern China. The seeds of C. oleifera have been reported to exhibit a diversity of pharmacological activities which include, but are not limited to, antioxidant, anti-cancer and antimicrobial. Pulmonary fibrosis is one of lethal causes of mortality across the globe and accretion of considerable amount of reactive oxygen species (ROS) in lungs have been implicated in the onset of this disease. Given the known antioxidant activity of C. oleifera seed extract (CSE), the present study was designed to evaluate the influence of CSE on the silica-induced pulmonary fibrosis rat models.Materials and Methods: Protective effect of CSE was determined in silica-induced pulmonary fibrosis rat models. Malondialdehyde (MDA), hydroxyproline (HP) and superoxide dismutase 2 (SOD-2) activity were determined by standard biochemical assays. Histopathological analysis was carried out by H and E staining. Phyto-constituents of CSE were identified by LC/MS analysis.Results: The results of this study indicated that CSE lowered the MDA and hydroxyproline content in silica-treated rats. Additionally, CSE also caused a significant increase in the expression of SOD-2 leading to scavenging of ROS. Hematoxylin and eosin (H and E) staining of lung tissue sections revealed that CSE maintained the integrity of parenchymatous cells of lungs and prevented the development of pulmonary fibrosis. To gain insights about the phytochemical constituents of CSE, LC/MS analysis was carried out and several antioxidant phenolics and flavonoids were tentatively identified.Conclusion: Taken together, we conclude that CSE prevents development of pulmonary fibrosis and the protective effect of CSE may be due to its ability to induce SOD-2 expression and due to the presence antioxidant phytoconstituents.Keywords: Pulmonary fibrosis, Silica, Camellia oleifera, Reactive oxygen species, Superoxide dismutas

Effects of cranberry powder on serum lipid profiles and biomarkers of oxidative stress in rats fed an atherogenic diet

This study investigated that the antioxidative effect of freeze-dried cranberry powder against protein and lipid oxidation and ameliorative effect of serum lipid profile in rat fed atherogenic diet. Six weeks old male Sprague-Dawley rats were divided into the following four groups: normal diet group with 5% corn oil (control), atherogenic diet group with 5% corn oil, 10% lard, 1% cholesterol, and 0.5% sodium cholate (HFC), atherogenic plus 2% cranberry powder diet group (HFC + C2), and atherogenic plus 5% cranberry powder diet group (HFC + C5), and respective diet and water were fed daily for 6 weeks. After the experimental period, the serum lipid profile, such as total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride, ferric reducing ability of plasma (FRAP), plasma phenolics content, superoxide dismutase (SOD) activity, serum protein carbonyl and thiobarbituric acid reactive substances (TBARS) levels were examined. Total phenolic compound and total flavonoid levels in freeze-dried cranberry powder were 9.94 mg/g and 8.12 mg/g, respectively. Serum total cholesterol and LDL-cholesterol levels were not significantly different for cranberry powder treatment, but serum HDL-cholesterol level was significantly increased in HFC + C5 group compared with HFC group. Plasma FRAP value tended to be increased by cranberry powder treatment though there was no significant difference. Plasma total phenol concentrations and SOD activities were not significantly different among all groups. Serum protein carbonyl and TBARS levels were significantly decreased in HFC + C5 group compared with HFC group. Overall results suggested that freeze-dried cranberry powder might have the serum lipid improving effect, as well as antioxidative effect demonstrated by its protective effect against protein and lipid oxidation

Hibiscus sabdariffa Linn. (Roselle) polyphenols-rich extract prevents hyperglycemia-induced cardiac oxidative stress and mitochondrial damage in diabetic rats

Cardiac mitochondrial damage plays a crucial role in the initiation of diabetic cardiomyopathy. Hibiscus sabdariffa Linn. (roselle) has been proven to prevent various pathological conditions, however it remains unclear whether roselle extract can attenuate diabetes-induced mitochondrial damage. This study aimed to investigate whether roselle polyphenol-rich extract (HPE) is able to ameliorate hyperglycemia-induced oxidative stress and mitochondrial damage in diabetic rats. Diabetes was induced by a single dose of streptozotocin (55 mg kg-1, intraperitoneally); and diabetic rats were then orally fed with 100 mg kg-1 of HPE (DM+Roselle) or 150 mg kg-1 of Metformin (DM+MET) daily for 4 weeks. Meanwhile, the control and untreated diabetic (DM) groups were only orally given normal saline. After 4 weeks of treatment, the results showed that DM+Roselle group significantly improved blood glucose level and lipid profile status (p<0.05) compared to the DM group. DM+Roselle group also had significantly (p<0.05) lower the level of thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein product (AOPP) in cardiac homogenate than the DM group. HPE supplementation also significantly improved activities of total superoxide dismutase (SOD), SOD-2, catalase (CAT) and level of reduced glutathione (GSH) of the cardiac homogenate. Complex I activity of mitochondria respiratory chain also decreased significantly (p<0.05) in DM+Roselle group as compared to the DM group. Observations using electron microscope showed that mitochondria in the DM+Roselle group appeared more organized compared to the DM group. In conclusion, these results highlight the potential of HPE as a protective agent against oxidative stress and mitochondrial damage in diabetic condition

Pretreatment of Human Cerebrovascular Endothelial Cells with CO-releasing Molecule-3 Interferes with JNK/AP-1 Signaling and Suppresses LPS-induced Proadhesive Phenotype.

OBJECTIVE: Exogenously administered CO interferes with PMN recruitment to the inflamed organs. The mechanisms of CO-dependent modulation of vascular proadhesive phenotype, a key step in PMN recruitment, are unclear. METHODS: We assessed the effects/mechanisms of CO liberated from a water-soluble CORM-3 on modulation of the proadhesive phenotype in hCMEC/D3 in an in vitro model of endotoxemia. To this end, hCMEC/D3 were stimulated with LPS (1 μg/mL) for six hours. In some experiments hCMEC/D3 were pretreated with CORM-3 (200 μmol/L) before LPS-stimulation. PMN rolling/adhesion to hCMEC/D3 were assessed under conditions of laminar shear stress (0.7 dyn/cm(2) ). In parallel, expression of adhesion molecules E-selectin, ICAM-1, and VCAM-1 (qPCR), activation of transcription factors, NF-κB and AP-1 (ELISA), and MAPK-signaling (expression/phosphorylation of p38, ERK1/2, and JNK1/2; western blot) were assessed. RESULTS: The obtained results indicate that CORM-3 pretreatment reduces PMN rolling/adhesion to LPS-stimulated hCMEC/D3 (p \u3c 0.05). Decreased PMN rolling/adhesion to hCMEC/D3 was associated with CORM-3-dependent inhibition of MAPK JNK1/2 activation (Tyr-phosphorylation), inhibition of transcription factor, AP-1 (c-Jun phosphorylation), and subsequent suppression of VCAM-1 expression (p \u3c 0.05). CONCLUSIONS: These findings indicate that CORM-3 pretreatment interferes with JNK/AP-1 signaling and suppresses LPS-induced upregulation of the proadhesive phenotype in hCMEC/D3

Sirt3 Exerts Its Tumor-Suppressive Role by Increasing p53 and Attenuating Response to Estrogen in MCF-7 Cells

Estrogen (E2) is a major risk factor for the initiation and progression of malignancy in estrogen receptor (ER) positive breast cancers, whereas sirtuin 3 (Sirt3), a major mitochondrial NAD+-dependent deacetylase, has the inhibitory effect on the tumorigenic properties of ER positive MCF-7 breast cancer cells. Since it is unclear if this effect is mediated through the estrogen receptor alpha (ERα) signaling pathway, in this study, we aimed to determine if the tumor-suppressive function of Sirt3 in MCF-7 cells interferes with their response to E2. Although we found that Sirt3 improves the antioxidative response and mitochondrial fitness of the MCF-7 cells, it also increases DNA damage along with p53, AIF, and ERα expression. Moreover, Sirt3 desensitizes cells to the proliferative effect of E2, affects p53 by disruption of the ERα–p53 interaction, and decreases proliferation, colony formation, and migration of the cells. Our observations indicate that these tumor-suppressive effects of Sirt3 could be reversed by E2 treatment only to a limited extent which is not sufficient to recover the tumorigenic properties of the MCF-7 cells. This study provides new and interesting insights with respect to the functional role of Sirt3 in the E2-dependent breast cancers

PROTECTIVE EFFECT OF CAMELLIA OLEIFERA ABEL. ON SILICA-INDUCED PULMONARY FIBROSIS IN RATS

Background: Camellia oleifera Abel. belongs to the family Theaceae and genus Camellia. It is commonly cultivated in southern China. The seeds of C. oleifera have been reported to exhibit a diversity of pharmacological activities which include, but are not limited to, antioxidant, anti-cancer and antimicrobial. Pulmonary fibrosis is one of lethal causes of mortality across the globe and accretion of considerable amount of reactive oxygen species (ROS) in lungs have been implicated in the onset of this disease. Given the known antioxidant activity of C. oleifera seed extract (CSE), the present study was designed to evaluate the influence of CSE on the silica-induced pulmonary fibrosis rat models. Materials and Methods: Protective effect of CSE was determined in silica-induced pulmonary fibrosis rat models. Malondialdehyde (MDA), hydroxyproline (HP) and superoxide dismutase 2 (SOD-2) activity were determined by standard biochemical assays. Histopathological analysis was carried out by H and E staining. Phyto-constituents of CSE were identified by LC/MS analysis. Results: The results of this study indicated that CSE lowered the MDA and hydroxyproline content in silica-treated rats. Additionally, CSE also caused a significant increase in the expression of SOD-2 leading to scavenging of ROS. Hematoxylin and eosin (H and E) staining of lung tissue sections revealed that CSE maintained the integrity of parenchymatous cells of lungs and prevented the development of pulmonary fibrosis. To gain insights about the phytochemical constituents of CSE, LC/MS analysis was carried out and several antioxidant phenolics and flavonoids were tentatively identified. Conclusion: Taken together, we conclude that CSE prevents development of pulmonary fibrosis and the protective effect of CSE may be due to its ability to induce SOD-2 expression and due to the presence antioxidant phytoconstituent

Endothelin-1 as a Mediator of Heme Oxygenase-1-Induced Stemness in Colorectal Cancer: Influence of p53

Heme oxygenase-1 (HO-1) is an antioxidant protein implicated in tumor progression, metastasis, and resistance to therapy. Elevated HO-1 expression is associated with stemness in several types of cancer, although this aspect has not yet been studied in colorectal cancer (CRC). Using an in vitro model, we demonstrated that HO-1 overexpression regulates stemness and resistance to 5-FU treatment, regardless of p53. In samples from CRC patients, HO-1 and endothelin converting enzyme-1 (ECE-1) expression correlated significantly, and p53 had no influence on this result. Carbon monoxide (CO) activated the ECE-1/endothelin-1 (ET-1) pathway, which could account for the protumoral effects of HO-1 in p53 wild-type cells, as demonstrated after treatment with bosentan (an antagonist of both ETRA and ETRB endothelin-1 receptors). Surprisingly, in cells with a non-active p53 or a mutated p53 with gain-of-function, ECE-1-produced ET-1 acted as a protective molecule, since treatment with bosentan led to increased efficiency for spheres formation and percentage of cancer stem cells (CSCs) markers. In these cells, HO-1 could activate or inactivate certain unknown routes that could induce these contrary responses after treatment with bosentan in our cell model. However more research is warranted to confirm these results. Patients carrying tumors with a high expression of both HO-1 and ECE-1 and a non-wild-type p53 should be considered for HO-1 based-therapies instead of ET-1 antagonists-based ones.Instituto de Salud Carlos IIIFEDER (PI18/01947)MINECO grant (DPI2017-84439-R)Nicolás Monardes Program from the Andalusian Health Service (C-0033-2015)FPU2019 fellowship (FPU19/02269) from the Ministerio de Ciencia, Innovación y Universidades (Spain

Mitochondrial glutathione: Features, regulation and role in disease

El pdf del artículo es la versión post-print.[Background]: Mitochondria are the powerhouse of mammalian cells and the main source of reactive oxygen species (ROS) associated with oxygen consumption. In addition, they also play a strategic role in controlling the fate of cells through regulation of death pathways. Mitochondrial ROS production fulfills a signaling role through regulation of redox pathways, but also contributes to mitochondrial damage in a number of pathological states. [Scope of review]: Mitochondria are exposed to the constant generation of oxidant species, and yet the organelle remains functional due to the existence of an armamentarium of antioxidant defense systems aimed to repair oxidative damage, of which mitochondrial glutathione (mGSH) is of particular relevance. Thus, the aim of the review is to cover the regulation of mGSH and its role in disease. [Major conclusions]: Cumulating evidence over recent years has demonstrated the essential role for mGSH in mitochondrial physiology and disease. Despite its high concentration in the mitochondrial matrix, mitochondria lack the enzymes to synthesize GSH de novo, so that mGSH originates from cytosolic GSH via transport through specific mitochondrial carriers, which exhibit sensitivity to membrane dynamics. Depletion of mGSH sensitizes cells to stimuli leading to oxidative stress such as TNF, hypoxia or amyloid β-peptide, thereby contributing to disease pathogenesis. [General significance]: Understanding the regulation of mGSH may provide novel insights to disease pathogenesis and toxicity and the opportunity to design therapeutic targets of intervention in cell death susceptibility and disease. This article is part of a Special Issue entitled Cellular functions of glutathione. © 2012 Elsevier B.V.The work was supported by grants: SAF2009-11417, SAF2010-15760, and SAF2011-23031 (Plan Nacional de I + D), Proyectos de Investigación en Salud PI10/02114 and PS09/00056 (Instituto de Salud Carlos III), P50-AA-11999 (Research Center for Liver and Pancreatic Diseases, US National Institute on Alcohol Abuse and Alcoholism) and by CIBEREHD from the Instituto de Salud Carlos III.Peer Reviewe