scholarly journals Multidirectional Changes in Parameters Related to Sulfur Metabolism in Frog Tissues Exposed to Heavy Metal-Related Stress

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 574
Author(s):  
Marta Kaczor-Kamińska ◽  
Piotr Sura ◽  
Maria Wróbel

The investigations showed changes of the cystathionine γ-lyase (CTH), 3-mercaptopyruvate sulfurtransferase (MPST) and rhodanese (TST) activity and gene expression in the brain, heart, liver, kidney, skeletal muscles and testes in frogs Pelophylax ridibundus, Xenopus laevis and Xenopus tropicalis in response to Pb2+, Hg2+ and Cd2+ stress. The results were analyzed jointly with changes in the expression of selected antioxidant enzymes (cytoplasmic and mitochondrial superoxide dismutase, glutathione peroxidase, catalase and thioredoxin reducatase) and with the level of malondialdehyde (a product of lipid peroxidation). The obtained results allowed for confirming the role of sulfurtransferases in the antioxidant protection of tissues exposed to heavy metal ions. Our results revealed different transcriptional responses of the investigated tissues to each of the examined heavy metals. The CTH, MPST and TST genes might be regarded as heavy metal stress-responsive. The CTH gene expression up-regulation was confirmed in the liver (Pb2+, Hg2+, Cd2+) and skeletal muscle (Hg2+), MPST in the brain (Pb2+, Hg2+), kidney (Pb2+, Cd2+), skeletal muscle (Pb2+, Hg2+,Cd2+) and TST in the brain (Pb2+) and kidney (Pb2+, Hg2+, Cd2+). Lead, mercury and cadmium toxicity was demonstrated to affect the glutathione (GSH) and cysteine levels, the concentration ratio of reduced to oxidized glutathione ([GSH]/[GSSG]) and the level of sulfane sulfur-containing compounds, which in case of enhanced reactive oxygen species generation can reveal their antioxidative properties. The present report is the first to widely describe the role of the sulfane sulfur/H2S generating enzymes and the cysteine/glutathione system in Pb2+, Hg2+ and Cd2+ stress in various frog tissues, and to explore the mechanisms mediating heavy metal-related stress.

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 767-768
Author(s):  
Vijay Varma ◽  
Youjin Wang ◽  
Yang An ◽  
Sudhir Varma ◽  
Murat Bilgel ◽  
...  

Abstract While Alzheimer’s disease (AD) and vascular dementia (VaD) may be accelerated by hypercholesterolemia, the mechanisms underlying this association is unclear. Using a novel, 3-step study design we examined the role of cholesterol catabolism in dementia by testing whether 1) the synthesis of the primary cholesterol breakdown products (bile acids (BA)) were associated with neuroimaging markers of dementia; 2) pharmacological modulation of BAs alters dementia risk; and 3) brain BA concentrations and gene expression were associated with AD. We found that higher serum concentrations of BAs are associated with lower brain amyloid deposition, slower WML accumulation, and slower brain atrophy in males. Opposite effects were observed in females. Modulation of BA levels alters risk of incident VaD in males. Altered brain BA signaling at the metabolite and gene expression levels occurs in AD. Dysregulation of peripheral cholesterol catabolism and BA synthesis may impact dementia pathogenesis through signaling pathways in the brain.


2016 ◽  
Vol 371 (1688) ◽  
pp. 20150114 ◽  
Author(s):  
Nancy G. Forger

Circumstantial evidence alone argues that the establishment and maintenance of sex differences in the brain depend on epigenetic modifications of chromatin structure. More direct evidence has recently been obtained from two types of studies: those manipulating a particular epigenetic mechanism, and those examining the genome-wide distribution of specific epigenetic marks. The manipulation of histone acetylation or DNA methylation disrupts the development of several neural sex differences in rodents. Taken together, however, the evidence suggests there is unlikely to be a simple formula for masculine or feminine development of the brain and behaviour; instead, underlying epigenetic mechanisms may vary by brain region or even by dependent variable within a region. Whole-genome studies related to sex differences in the brain have only very recently been reported, but suggest that males and females may use different combinations of epigenetic modifications to control gene expression, even in cases where gene expression does not differ between the sexes. Finally, recent findings are discussed that are likely to direct future studies on the role of epigenetic mechanisms in sexual differentiation of the brain and behaviour.


Biomeditsina ◽  
2019 ◽  
pp. 12-22
Author(s):  
N. V. Petrova

It is shown that the level of the Lep gene expression is a marker for B/Ks-Leprᵈᵇ/+ mice, which line serves as an optimal model for describing metabolic syndrome (MS) in preclinical studies. Mice were transplanted with cultured isogenic bone marrow cells (BMC) from heterozygous db/+ donors. The recipients were divided into two groups according to an early or advanced stage of MS development. We analyzed the expression of the Lep gene on the 3rd, 8th and 14th day following the administration of stem BMCs in the brain, liver and pancreas cells by polymerase chain reaction (PCR) in real time. The Lep gene expression was evaluated in terms of the number of cDNA copies. According to our data, leptin is a complete regulator of metabolic processes due to its effect on the hypothalamus, which, together with the hippocampus, controls the production of acetylcholine and insulin in the brain. We have proven the role of the Lep gene as a quantitative criterion for evaluating the effi cacy of a cell therapy in MS.


2019 ◽  
Vol 116 (20) ◽  
pp. 9893-9902 ◽  
Author(s):  
Christopher M. Uyehara ◽  
Daniel J. McKay

The ecdysone pathway was among the first experimental systems employed to study the impact of steroid hormones on the genome. In Drosophila and other insects, ecdysone coordinates developmental transitions, including wholesale transformation of the larva into the adult during metamorphosis. Like other hormones, ecdysone controls gene expression through a nuclear receptor, which functions as a ligand-dependent transcription factor. Although it is clear that ecdysone elicits distinct transcriptional responses within its different target tissues, the role of its receptor, EcR, in regulating target gene expression is incompletely understood. In particular, EcR initiates a cascade of transcription factor expression in response to ecdysone, making it unclear which ecdysone-responsive genes are direct EcR targets. Here, we use the larval-to-prepupal transition of developing wings to examine the role of EcR in gene regulation. Genome-wide DNA binding profiles reveal that EcR exhibits widespread binding across the genome, including at many canonical ecdysone response genes. However, the majority of its binding sites reside at genes with wing-specific functions. We also find that EcR binding is temporally dynamic, with thousands of binding sites changing over time. RNA-seq reveals that EcR acts as both a temporal gate to block precocious entry to the next developmental stage as well as a temporal trigger to promote the subsequent program. Finally, transgenic reporter analysis indicates that EcR regulates not only temporal changes in target enhancer activity but also spatial patterns. Together, these studies define EcR as a multipurpose, direct regulator of gene expression, greatly expanding its role in coordinating developmental transitions.


2009 ◽  
Vol 297 (4) ◽  
pp. R1037-R1048 ◽  
Author(s):  
Clay E. Pandorf ◽  
Weihua H. Jiang ◽  
Anqi X. Qin ◽  
Paul W. Bodell ◽  
Kenneth M. Baldwin ◽  
...  

The role of calcineurin (Cn) in skeletal muscle fiber-type expression has been a subject of great interest because of reports indicating that it controls the slow muscle phenotype. To delineate the role of Cn in phenotype remodeling, particularly its role in driving expression of the type I myosin heavy chain (MHC) gene, we used a novel strategy whereby a profound transition from fast to slow fiber type is induced and examined in the absence and presence of cyclosporin A (CsA), a Cn inhibitor. To induce the fast-to-slow transition, we first subjected rats to 7 days of hindlimb suspension (HS) + thyroid hormone [triiodothyronine (T3)] to suppress nearly all expression of type I MHC mRNA in the soleus muscle. HS + T3 was then withdrawn, and rats resumed normal ambulation and thyroid state, during which vehicle or CsA (30 mg·kg−1·day−1) was administered for 7 or 14 days. The findings demonstrate that, despite significant inhibition of Cn, pre-mRNA, mRNA, and protein abundance of type I MHC increased markedly during reloading relative to HS + T3 ( P < 0.05). Type I MHC expression was, however, attenuated by CsA compared with vehicle treatment. In addition, type IIa and IIx MHC pre-mRNA, mRNA, and relative protein levels were increased in Cn-treated compared with vehicle-treated rats. These findings indicate that Cn has a modulatory role in MHC transcription, rather than a role as a primary regulator of slow MHC gene expression.


2006 ◽  
Vol 17 (2) ◽  
pp. 1018-1032 ◽  
Author(s):  
Brice Enjalbert ◽  
Deborah A. Smith ◽  
Michael J. Cornell ◽  
Intikhab Alam ◽  
Susan Nicholls ◽  
...  

The resistance of Candida albicans to many stresses is dependent on the stress-activated protein kinase (SAPK) Hog1. Hence we have explored the role of Hog1 in the regulation of transcriptional responses to stress. DNA microarrays were used to characterize the global transcriptional responses of HOG1 and hog1 cells to three stress conditions that activate the Hog1 SAPK: osmotic stress, oxidative stress, and heavy metal stress. This revealed both stress-specific transcriptional responses and a core transcriptional response to stress in C. albicans. The core transcriptional response was characterized by a subset of genes that responded in a stereotypical manner to all of the stresses analyzed. Inactivation of HOG1 significantly attenuated transcriptional responses to osmotic and heavy metal stresses, but not to oxidative stress, and this was reflected in the role of Hog1 in the regulation of C. albicans core stress genes. Instead, the Cap1 transcription factor plays a key role in the oxidative stress regulation of C. albicans core stress genes. Our data show that the SAPK network in C. albicans has diverged from corresponding networks in model yeasts and that the C. albicans SAPK pathway functions in parallel with other pathways to regulate the core transcriptional response to stress.


1999 ◽  
Vol 96 (6) ◽  
pp. 3223-3227 ◽  
Author(s):  
A. O. Gramolini ◽  
L. M. Angus ◽  
L. Schaeffer ◽  
E. A. Burton ◽  
J. M. Tinsley ◽  
...  

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