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Regulatory RNAs in the brain

100%

Gabryelska M., Szymański M., Barciszewska M. Z., Barciszewski J.

Nauka

2008

issue 2

Nervous system is characterized by its uniqueness in cells origin, their variability, electrical properties of the nervous cell membrane, response to external signals, neuronal network and changes in synapses activity that are the basis of higher brain functions, such as learning and memory. Brain is a superior organ of human body with an extremely efficient regulation system. Apart from protein and small-molecule regulators, ribonucleic acids (RNAs), especially noncoding proteins (ncRNAs), play a crucial controlling role in the brain. They are present in every cell, from bacteria to primates and have regulatory, catalytic as well as structural function. Many specific ncRNAs have been identified in human brain, responsible for development and functioning. Disturbances in ncRNA synthesis and mechanism of action are connected to diseases such as autism, schizophrenia, Alzheimer disease, Prader-Willi syndrome and others.

New face of the “RNA world”

100%

Tyczewska A., Figlerowicz M.

Nauka

2009

issue 2

For a very long time, RNA was considered just the medium by which information flows from DNA into the cell. The model proposed in the 1960s assumed that proteins are the main products and regulators of the gene expression process. In this context, the results of the Human Genome Project and the discoveries of RNA interference and small regulatory RNAs (srRNAs) came as a true surprise. The first ones demonstrated that less than 5% of the human genome encodes proteins. The second showed that RNA, especially 20-30 nt-long molecules should be placed among the most important factors controlling gene expression. srRNAs are capable of affecting the release and flow of genetic information in many different ways. They can induce changes in the genome structure, inhibit transcription, mediate mRNA degradation and repress translation. Interestingly, in different organisms, different pathways are used to regulate gene expression. It has recently been estimated that, in humans, the expression of 35-40% of genes is controlled by srRNA. As a result, RNA is currently believed to be a central molecule in many biological processes.

Revision of reciprocal action of mercury and selenium

75%

Kuraś R., Janasik B., Wąsowicz W., Stanisławska M.

International Journal of Occupational Medicine and Environmental Health

2018

vol. 31

issue 5

575-592

Diverse forms of mercury (Hg) have various effects on animals and humans because of a variety of routes of administration. Inorganic mercury (iHg) binds to thiol groups of proteins and enzymes in one’s body or is methylated by microorganisms. Organic form of Hg, contrary to the iHg, is more stable but may be demethylated to Hg2+ in the tissue of intestinal flora. Selenium (Se) also occurs in a variety of chemical forms in one’s body but both of these elements behave very differently from one another. Mercury binding to selenide or Se-containing ligands is a primary molecular mechanism that reduces toxicity of Hg. Complexes formed in such a way are irreversible, and thus, biologically inactive. Se deficiency in a human body may impair normal synthesis of selenoproteins and its expression because expression of mRNA may be potentially regulated by the Se status. This paper provides a comprehensive review concerning Hg–Se reciprocal action as a potential mechanism of protective action of Se against Hg toxicity as well as a potential detoxification mechanism. Although interactions between Hg–Se have been presented in numerous studies concerning animals and humans, we have focused mainly on animal models so as to understand molecular mechanisms responsible for antagonism better. The review also investigates what conclusions have been drawn by researchers with respect to the chemical species of Se and Hg (and their relationship) in biological systems as well as genetic variations and expression and/or activity of selenoproteins related to the thioredoxin (thioredoxin Trx/TrxR) system and glutathione metabolism. Int J Occup Med Environ Health 2018;31(5):575–592

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2 Nauka

1 International Journal of Occupational Medicine and Environmental Health

1 Barciszewska M. Z.

1 Barciszewski J.

1 Figlerowicz M.

1 Gabryelska M.

1 Janasik B.

1 Kuraś R.

1 Stanisławska M.

1 Szymański M.

1 Tyczewska A.

1 Wąsowicz W.

1 2018

1 2009

1 2008

Search results

Regulatory RNAs in the brain

New face of the “RNA world”

Revision of reciprocal action of mercury and selenium