Postepy biochemii最新文献

Ectodermal dysplasias are a wide group of genetic disorders characterised by clinical symptoms in ectodermal derivatives (most frequently teeth, hair, nails and sweat glands). There is a number of genes, which, if mutated, can cause the specified phenotype. The molecular basis of many ectodermal dysplasias have been investigated. The phenotype often results from the imparied communication in molecular pathways important in embryonic morphogenesis or disturbed function of protein complexes involved in homeostasis, adhesion and stability of the cells in the tissue. Different classification systems have been proposed to group ectodermal dysplasias according toclinical symptoms or molecular basis. Molecular technologies have let recently to expand diagnostic abilities for ectodermal dysplasias patients. Certainly in the nearest years new genes and mutations will be discovered as a cause of ectodermal dysplasias.

Midbrain dopamine neurons along with the major target of their projections, dopaminoceptive neurons in striatum, regulate reinforcement learning and motivation. The activity and plasticity in the dopamine system are largely dependent on excitatory glutamatergic transmission. The article describes the functional role of N-methyl-D-aspartate (NMDA) receptors in driving the phasic activity in dopamine neurons, and a role of NMDA and metabotropic glutamate 5 (mGluR5) receptors in induction of plasticity in dopaminoceptive striatal medium spiny neurons. Based on published studies on genetically modified mice, the article further discusses how targeted loss of glutamate receptor-dependent signalling in dopamine system affects reinforcement learning and motivational processes. The conclusion of the article is the view that aberrant glutamate signalling in dopamine system may contribute to maladaptive behaviours, which are particularly often observed in mental disorders.

Lysosomal acid lipase (LAL) plays a key role in lipid metabolism through the hydrolysis of cholesteryl esters and triglycerides in lysosomes. LAL deficiency is a rare autosomal recessive lysosomal storage disease caused by deleterious mutations in the LIPA gene. In the case of LAL deficiency, cholesteryl esters and triglycerides accumulate within the lysosomes. The up-regulation of endogenous cholesterol production, increased synthesis of apolipoprotein B (ApoB) and increased production of very-low-density lipoprotein cholesterol (VLDL-C) is observed. The diagnosis is easy due to the currently available method of testing the enzyme activity in a dry blood spot. Molecular analysis is necessary to verify the clinical and biochemical diagnosis and to analyze the genotype-phenotype correlation. Sebelipase alfa is a recombinant human lysosomal lipase intended for use in enzyme replacement therapy in patients with LAL deficiency.

Photodynamic therapy (PDT) is one of the least toxic methods causing the death of cancer cells. Photosensitizer (PS) applied to a patient accumulates in the tumor, where under the appropriate wavelength and insensitivity of light is activated. Activated PS in the presence of oxygen produces reactive oxygen species (ROS), which make significant damage leading to the destruction of cancer cells by apoptosis, necrosis or autophagic process. Moreover, PDT causes an acute local inflammatory response that is involved in removing dead cells, restoring normal tissue homeostasis, and sometimes leads to the development of systemic immunity. However, some cells may survive treatment and develop resistance. Mechanisms, which lead to decrease of the level of PS in cells may be involved in the cytoprotection of cancer cells from PDT. Furthermore, increased activity of antioxidant mechanisms, overexpression of molecular chaperones and activation of survival pathways can protect cells from PDT.

Crossover is a reciprocal exchange of chromatid fragments between homologous chromosomes and takes place during second meiotic division. Many factors affect the distribution and frequency of crossovers – for instance, the activity of trans-acting modifiers, chromatin methylation level or the presence of polymorphisms between recombining chromosomes. MMR system, and specifically MSH2 protein, serves to recognize and repair mismatched DNA bases, and prevents recombination between divergent chromosomal regions during meiosis. Unexpectedly, MSH2 displays also a pro-recombination role in plants by detecting polymorphisms and directing crossover events into more diverged regions. In this review, we demonstrate how interhomolog polymorphism may affect crossover chromosomal distribution and, as a consequence, plant genomes evolution. It is especially important for self-fertilizing plants which naturally exhibit high level of homozygosity. If recombination were to occur only in homozygous regions, no new genotypes would be created in subsequent generations, slowing down the evolution of the organisms.

The year 2021 marks not only 60 years since the discovery of messenger RNA and the genetic code. Already 100 yaers passed since RNA was discovered. On the occasion of this special anniversary, we would like to recall the most important events in the history of nucleic acids that led to the above discoveries. We remind the beginning of a new era in science caused by the isolation of nuclein and then nucleic acid, whose components and properties were gradually learned, often by little-known researchers. The distinction of RNA and DNA and the analysis of their occurrence in cells made it possible to formulate the first conclusions about the functions of these compounds. Conclusions on the ratio of nitrogenous bases in DNA led to the knowledge of the structure of the double helix, triggering an avalanche of questions about the essence of transmission of genetic information. Answers began to emerge with the discovery of mRNA, and knowledge of the first three nucleotides encoding an amino acid caused a race to decipher the genetic code. The above discoveries are the foundation of molecular biology. The diamond jubilee coincided with the development of an mRNA-based vaccine against the SARS-CoV-2.

Plants are natural laboratories producing a cornucopia of secondary metabolites of huge therapeutic potential. The oil extracted from rice bran, a by-product of brown rice processing, is abundant in valuable bioactive substances. One of its main ingredients is gamma-oryzanol that is a mixture of phytosterol esters and ferulic acid. These compounds exert a wide range of biological activities closely correlated with their chemical properties. Their hypocholesterolemic and antioxidant abilities are crucial for improving the physiology and condition of the human body. For these reasons, there has been a clear increase in the number of studies investigating the use of gamma-oryzanol in the treatment of many chronic diseases, and it is even tested as a promising non-pharmacological therapeutic agent in the treatment of COVID-19 in overweight people. This paper describes the chemical structure and activity of gamma-oryzanol based on biological activity of phytosterol esters and ferulic acid. It also discusses the effects of gamma-oryzanol on some physiological processes in the human and animal organisms.

The aim of this article is to synthesize informations about monoamine oxidase inhibitors drugs (MAOI) used in the treatment of depression. General informations on monoamine oxidase (MAO) and its kinetic properties are presented. MAO is an enzyme that degrades catecholamines and their 3-methoxy derivatives and other monoamines, for example serotonin or tryptamine. The criteria and symptoms of depressive disorders are discussed. They have to be distinguished from the state of sadness and similar states. The basic symptoms include: voice, facial expressions, anhedonia and psychomotor slowness. They may differ in individual diagnostic units. The following basic mechanism of the pharmacological action of MAOI has been indicated: when a drug inhibits MAO, the degradation of monoamines decreases and the concentration of the neurotransmitter in the synaptic cleft increases. Informations on selected selective and reversible MAOI-A are presented in the following sections. These are currently the safest and most effective MAOI drugs that can be used in the treatment of depressive diseases. The following drugs are discussed: moclobemide, befloxatone, toloxatone and brofaromine. Final conclusions are given and the presented data summarized.

Changes in glycosylation pattern of cell surface, body fluids and extracellular matrix glycoconjugates is a characteristic feature of tumor cell malignancy. These changes are the result of mutations of tumor-associated genes as well as epigenetic changes in the tumor environment, including nutrient influx, hypoxia, cytokine expression and stimulation of chronic inflammation. The unique set of cell surface glycoantigens on neoplastic cells is recognized by endogenous lectins located in the extracellular matrix, vascular endothelium, on leukocytes or platelets, and has an impact on disrupting basic cellular processes, such as intercellular recognition, cell-cell adhesion or cell-ECM interaction. These changes have a critical impact on the migration, invasive and metastatic potential of neoplastic cells and modulate the immune response. This unique pattern of sugar antigens on the cancer cells can be a vaulable marker to identify them, determine the stage of the disease as well as be a target of anti-cancer therapy.

The research concerned the determination of the frequency of occurrence of selected virulence genes (cadF, flaA, iam) and genes responsible for the formation of the CDT cytotoxin (cdtA, cdtB, cdtC) in Campylobacter spp. The research object consisted of 100 faecal samples collected from stallions showing no symptoms of campylobacteriosis. The presence of bacteria of the genus Campylobacter spp. Was found in 25 individuals (25%). The molecular biology techniques used in the research allowed us to distinguish the following species from the positive samples: C. jejuni (68%); C. coli (28%) and C. lari (4%). In total, the following genes were found within the marked species: cadF (n=10); flaA (n=5); iam (n=3); cdtA (n=1); cdtB (n=10) and cdtC (n=2). In none of the obtained isolates, the simultaneous presence of genes responsible for the synthesis of CDT toxin was found.