Low expression ofMRP1/GS-X pump ATPase in lymphocytes of Walker 256 tumour-bearing rats is associated with cyclopentenone prostaglandin accumulation and cancer immunodeficiency

et al. 2016

Nutrire

Aging is an intricate process modulated by different molecular and cellular events, such as genome instability, epigenetic and transcriptional changes, molecular damage, cell death and senescence, inflammation, and metabolic dysfunction. Particularly, protein quality control (chaperone systems) tends to be negatively affected by aging, thus leading to cellular senescence in metabolic tissues and, as a consequence, to the increasing dissemination of inflammation throughout the body. The heat shock (HS) response and its associated expression of the 70 kDa family of heat shock proteins (HSP70), which are anti-inflammatory molecular chaperones, are found to be markedly decreased during muscle inactivity and aging, while evidence supports the loss of HSP70 as a key mechanism which may drive muscle atrophy, contractile dysfunction, and reduced regenerative capacity. In addition, abnormal stress response is linked with higher incidence of neurodegenerative diseases as well as low-grade inflammatory diseases that are associated with physical inactivity and obesity. Therefore, strategies to increase or, at least, to maintain the levels of HSP70, and its accompanying HS response to stress, are key to reduce biological cell dysfunctions that occur in aging. In this sense, physical exercise is of note as it is the most powerful inducer of the HS response, comparable only to heat stress and fever-like conditions. On the other hand, the amino acid L-glutamine, whose production within the skeletal muscle and liberation into the blood stream is dependent on muscle activity, is a potentializer of HSP70 expression and HS response, particularly via its entering in hexosamine biosynthetic pathway (HBP). Herein, we discuss the collaborative role of glutamine (and its donors/precursors) and physical exercise (mostly responsible for glutamine release into the circulation) as potential tools to increase HSP70 expression and the HS response in the elderly.

Section: Anti-inflammatory Role Of Intracellular Hsp70mentioning

confidence: 99%

Physiological regulation of the heat shock response by glutamine: implications for chronic low-grade inflammatory diseases in age-related conditions

Leite

Cruzat

et al. 2016

Nutrire

“…12 Skeletal and cardiac muscle plasma membrane preparation and the assay of MRP/GS-X pump ATPase activity…”

Section: Measurement Of Gsh and Gssgmentioning

confidence: 99%

“…Vectorial GS-conjugate export has been previously confirmed in membrane vesicles using a radiometric method, 16 and MRP/GS-X pump activity was assessed by using a non-radiochemical easy-to-use approach developed by this laboratory. 12 The method is based on GSconjugate (GSSG)-driven hydrolysis of ATP which is coupled to pyruvate formation by adding phosphoenol-pyruvate (ICN, 2 mM) in the presence of pyruvate kinase (Sigma, 1 U/ml). ATPase activity was calculated by monitoring (in a GE-Amersham Ultrospec 2000 temperature-controlled spectrophotometer) the decrease in absorbance at 340 nm due to the consumption of b-NADH (Sigma, 200 mM) during the lactic dehydrogenase (Sigma, 1 U/ml)-catalysed reaction.…”

Section: Measurement Of Gsh and Gssgmentioning

confidence: 99%

“…In order to evaluate the capacity for GS-conjugate transport of membrane enriched samples, plasma membrane vesicles were prepared and assayed 12 by an adaptation of the protocol described, 16 using Lubrol solubilised microsomal fraction. Vectorial GS-conjugate export has been previously confirmed in membrane vesicles using a radiometric method, 16 and MRP/GS-X pump activity was assessed by using a non-radiochemical easy-to-use approach developed by this laboratory.…”

Section: Measurement Of Gsh and Gssgmentioning

confidence: 99%

“…Vanadate-sensitive magnesium-dependent glutathione S-conjugate (GS-conjugate) ATPase (GS-X pump) activity of certain MRPs (which belong to the ABCC gene family of ATP-dependent membrane carriers) underlies this property, since MRP/GS-X pumps export hydrophobic electrophiles (including doxorubicin, methotrexate and cyclopentenone prostaglandins) as GS-conjugates or even in co-transport with intact GSH molecules out of the cells (see a complete list of the ABCC gene products and their role in the resistance to the treatment with different electrophilic compounds 12 ). This suggests that doxorubicin-induced cardiotoxicity (which is dependent on GSH depletion) occurs because this anthracycline forms GS-conjugates which strongly compete with glutathione disulphide (GSSG) for the extrusion towards the extracellular space via MRP/ GS-X pumps.…”

mentioning

confidence: 99%

See 2 more Smart Citations

MRP1/GS‐X pump ATPase expression: is this the explanation for the cytoprotection of the heart against oxidative stress‐induced redox imbalance in comparison to skeletal muscle cells?

Cell Biochemistry & Function

Oliveira

Silveira

et al. 2006

Self Cite

Striated muscle activity is always accompanied by oxidative stress (OxStress): the more intense muscle work and/or its duration, the more a redox imbalance may be attained. In spite of cardiac muscle functioning continuously, it is well known that the heart does not suffer from OxStress-induced damage over a broad physiological range. Although the expression of antioxidant enzymes may be of importance in defending heart muscle against OxStress, a series of combined antioxidant therapeutic approaches have proved to be mostly ineffective in avoiding cellular injury. Hence, additional mechanisms may be involved in heart cytoprotection other than antioxidant enzyme activities. The strong cardiotoxic effect of doxorubicin-induced cancer chemotherapy shed light on the possible role for multidrug resistance-associated proteins (MRP) in this context. Muscle activity-induced 'physiological' OxStress enhances the production of glutathione disulfide (GSSG) thus increasing the ratio of GSSG to glutathione (GSH) content inside the cells, which, in turn, leads to redox imbalance. Since MRP1 gene product (a GS-X pump ATPase) is a physiological GSSG transporter, adult Wistar rats were tested for MRP1 expression and activity in the heart and skeletal muscle (gastrocnemius), in as much as the latter is known to be extremely sensitive to muscle activity-induced OxS. MRP1 expression was completely absent in skeletal muscle. In contrast, the heart showed an exercise training-dependent induction of MRP1 protein expression which was further augmented (2.4-fold) as trained rats were challenged with a session of acute exercise. On the other hand, inducible expression of the 70-kDa heat shock protein (HSP70), a universal marker of cellular stress, was completely absent in the heart of sedentary and acutely exercised rats, whereas skeletal muscle showed a conspicuous exercise-dependent HSP70 expression, which decreased by 45% with exercise training. This effect was paralleled by a 58% decrease in GSH content in skeletal muscle which was even higher (an 80%-fall) after training thus leading to a marked redox imbalance ([GSSG]/[GSH] raised up to 38-fold). In the heart, GSH contents and [GSSG]/[GSH] ratio remained virtually unchanged even after exercise challenges, while GS-X pump activity was found to be 20% higher in the heart related to skeletal muscle. These findings suggest that an intrinsic higher capacity to express the MRP1/GS-X pump may dictate the redox status in the heart muscle thus protecting myocardium by preventing GSSG accumulation in cardiomyocytes as compared to skeletal muscle fibres.

Acute exercise stimulates macrophage function: possible role of NF‐κB pathways

Silveira

Rodrigues

Cell Biochemistry & Function

et al. 2006

Self Cite

Moderate physical activity when performed on a regular basis presents a number of benefits to the whole organism, especially regarding immune system function, such as augmenting resistance to infections and to cancer growth. Although glutamine production by active muscle cells as well as neuroendocrine alterations mediated by the chronic adaptation to exercise may play a role, the entire mechanism by which exercise makes the immune system aware of challenges remains mostly uncovered. This is particularly true for the effects of an acute exercise session on immune function. In this work, circulating monocytes/macrophages from sedentary rats submitted to an acute (1 h) swimming session were tested for the ability of phagocytosing zymosan particles, phorbol miristate acetate (PMA)-induced hydrogen peroxide production, nitric oxide (NO) release (assessed by nitrate and nitrite production) and the expression of NO synthases (NOS-1, NOS-2 and NOS-3). The results showed that an exercise bout induced a 2.4-fold rise in macrophage phagocytic capacity (p ¼ 0.0041), a 9.6-fold elevation in PMA-induced hydrogen peroxide release into the incubation media (1-h, p ¼ 0.0022) and a 95.5%-augmentation in nitrite basal production (1-h incubation; p ¼ 0.0220), which was associated with a marked expression of NOS-2 (the inducible NOS isoform; p ¼ 0.0319), but not in other NOS gene products. Although NOS-2 expression is nuclear factor-kB (NF-kB)-dependent, no systemic oxidative stress was found, as inferred from the data of plasma TBARS and glutathione disulphide (GSSG) to glutathione (GSH) ratio in circulating blood erythrocytes which remained constant after the acute exercise. Also, no stressful situation seemed to be faced by monocytes/macrophages, since the expression of the 70-kDa heat shock protein (HSP70) remained unchanged. We conclude that NF-kB-dependent induction of NOS-2 and macrophage activation must be related to local factor(s) produced in the surroundings of monocytes/macrophages.