Postepy biochemii最新文献

Rhodopsin proteins are found in all three domains of life, and the two best-known types to date are animal and microbial rhodopsins. Animal rhodopsins are found only in animals, while microbial rhodopsins are found in microorganisms in all domains, and mainly in protists among eukaryotes. All known rhodopsins have a similar structure, consisting of seven transmembrane α-helices and a retinal ligand. Animal and microbial types do not show sequence similarity, suggesting their convergent evolution. Animal rhodopsins are responsible for vision and control of the biological clock, while microbial rhodopsins are responsible for cell phototaxis and also act as hydrogen or ion pumps. These processes may be involved in converting energy from photons into energy used by the cell. A lot more is known about rhodopsins in marine microorganisms than in freshwater ones. The differences between rhodopsins appearing in these two ecosystems can be significant because they are characterized by different environmental conditions, which lead to different optical properties, consequently affecting the sequences and structure of rhodopsins.

Lung cancer remains one of the leading causes of cancer-related mortality worldwide and is strongly associated with tobacco smoke exposure. In recent years, electronic cigarettes have gained popularity as seemingly safer alternatives to conventional cigarettes; however, their impact on tumor biology remains controversial. A central process in lung cancer progression is the epithelial–mesenchymal transition (EMT), which promotes cellular invasion, migration, and therapy resistance. This review summarizes current evidence on how nicotine, polycyclic aromatic hydrocarbons (PAHs), carbonyl compounds, and reactive oxygen species (ROS) modulate EMT through key signaling pathways, including PI3K/AKT, MAPK/ERK, Wnt/β-catenin, Notch, and HIF-1α. Moreover, it discusses the role of thermal processes during tobacco combustion and e-liquid heating in generating carcinogenic by-products. Emerging data indicate that both traditional and electronic cigarettes release bioactive agents capable of inducing EMT, thereby contributing to lung cancer pathogenesis and revealing potential therapeutic targets.

Chemical modifications of DNA and RNA play a pivotal role in the regulation of gene expression, enabling precise control of cellular functions and adaptation to changing environmental conditions. The most common modification in human DNA is cytosine methylation at the 5th position (5mC), while in RNA it is adenosine methylation at the N6 position (m⁶A), recognized as the predominant epitranscriptomic modification. Regulation of these modifications relies on the coordinated action of three groups of proteins: methyltransferases, demethylases, and reader proteins, which recognize modified nucleobases and recruit effector protein complexes, thereby translating the pattern of nucleic acid modifications into a specific biological response. Dysfunction of these protein groups leads to aberrant 5mC and m⁶A patterns, which play a crucial role in the pathogenesis and progression of many human diseases, including cancer. Deregulation of DNA and RNA methylation affects, among others, the control of genes involved in proliferation, apoptosis, and genome stability, which may promote tumor progression; moreover, the dynamic and reversible nature of these modifications makes them attractive diagnostic and therapeutic targets in cancer treatment.

Skeletal muscle is a dynamic tissue involved not only in mechanical functions but also in the regulation of metabolic and immune processes. It secretes signaling molecules known as myokines, which act in autocrine, paracrine, and endocrine ways- affecting both muscle function and other tissues and organs. Well-known myokines include myostatin, IL-6, IL-15, FGF21, and irisin. They regulate muscle mass and strength, promote angiogenesis, maintain glucose and lipid homeostasis, and contribute to immune and anti-cancer responses. Their activity depends on physiological and pathological conditions at both local and systemic levels. Notably, myokine secretion varies with muscle fiber type, influencing their specific biological effects. Understanding how myokines are regulated and function may support the development of new therapies in regenerative medicine, oncology, and metabolic disease treatment.

Epigenetic regulation of gene expression is an intensively studied area of molecular biology. It includes cytosine methylation, whose mechanism of action in nuclear DNA is relatively well understood. This process is mediated by enzymes from the DNA methyltransferase family. Hydroxymethylation is, considered both an intermediate step in cytosine demethylation and a potentially independent mechanism of regulation of gene expression. Functional significance—and even the presence—of methylation within mitochondrial DNA (mtDNA) remains a matter of debate.Accumulated evidence indicates that methylation and hydroxymethylation may play important role in mitochondria. Although epigenetic regulation of gene expression in mitochondria is not yet fully understood, the current state of knowledge suggests that it may influence proper cellular function and the pathogenesis of numerous diseases.

Despite medical advances, heart disease is now the world's biggest health problem, with a sharp rise in deaths. The most dangerous and common of these are heart attack and heart failure, which can lead to acute coronary syndromes and are very dangerous. Research into biochemical markers of heart disease is being driven by the need for earlier diagnosis. Assumptions include the ability to detect these markers early on, their high specificity for the heart muscle, and the reliability of assay results. Cardiac troponins and natriuretic peptides, which are already used as diagnostic tools, are crucial in diagnosing heart attacks and heart failure. ST-2 and h-FABP proteins show promise as diagnostic tools, but none of the markers discovered so far are ideal. The scientific literature on biomarkers of heart dysfunction highlights the concern among professionals. Research findings need further analysis. These solutions could transform global cardiology.

The aim of this article is to review selected information on the latest atypical antipsychotic drugs that are characterized by partial agonism of dopamine D2 receptors: brexpiprazole, aripiprazole, cariprazine and lumateperone. The paper discusses the localization and biochemical aspects of D2 receptors. A particularly important site for neuroleptic interactions is the ventral striatopallidal system and the structures comprising the mesocortical pathway, which, among other things, extends to the frontal lobes exhibiting various structural and functional abnormalities in schizophrenia. The symptomatic and syndromic profile of schizophrenia has been described, along with practical guidelines for clinicians. Both archaic psychopathological divisions (e.g., the dichotomy of positive and negative symptoms, primary and secondary symptoms) and contemporary divisions (ICD-11) were taken into account. Brexpiprazole, which is a quinoline derivative, is structurally very similar to aripiprazole. However, it has a slightly different psychopharmacological mechanism centred around lower dopaminergic activity, which translates into a lower risk of developing extrapyramidal symptoms and stronger serotonergic affinity, implying anxiolytic, antidepressant, and procognitive effects. Cariprazine, which is an N-alkylpiperazine, acts as an antagonist for serotonergic receptors and as an agonist for dopaminergic receptors. Studies indicate that, in addition to schizophrenia, it has satisfactory clinical effects in psychotic states in the elderly and agitation of various etiologies. Lumateperone (ITI-007) stands out from the other discussed in this paper drugs due to its modulation of the glutamatergic system. In the case of its mechanism of action, it is also referred to in scientific literature as a dopamine phosphoprotein modulator. Each of the listed here drugs has the potential to reduce positive (delusions, hallucinations) and negative (cognitive impairment, autism, the "ambi" group) symptoms. Their metabolism mainly involves the CYP3A4 and CYP2D6 enzymes. The use of the drugs analyzed in this paper is not limited to schizophrenia-related psychosis. They also achieve significant clinical effects in certain affective disorders (especially those with psychotic states) and neurodevelopmental units. The prospects for further research into new antipsychotic substances were highlighted, which are likely to focus on modulating the activity of the dopaminergic, serotonergic, and glutamatergic systems.