New biomarkers: prospect for diagnosis and monitoring of thyroid disease.

After the metabolic syndrome and its components, thyroid disorders represent the most common endocrine disorders, with increasing prevalence in the last two decades. Thyroid dysfunctions are distinguished by hyperthyroidism, hypothyroidism, or inflammation (thyroiditis) of the thyroid gland, in addition to the presence of thyroid nodules that can be benign or malignant. Thyroid cancer is typically detected via an ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) and cytological examination of the specimen. This approach has significant limitations due to the small sample size and inability to characterize follicular lesions adequately. Due to the rapid advancement of high-throughput molecular biology techniques, it is now possible to identify new biomarkers for thyroid neoplasms that can supplement traditional imaging modalities in postoperative surveillance and aid in the preoperative cytology examination of indeterminate or follicular lesions. Here, we review current knowledge regarding biomarkers that have been reliable in detecting thyroid neoplasms, making them valuable tools for assessing the efficacy of surgical procedures or adjunctive treatment after surgery. We are particularly interested in providing an up-to-date and systematic review of emerging biomarkers, such as mRNA and non-coding RNAs, that can potentially detect thyroid neoplasms in clinical settings. We discuss evidence for miRNA, lncRNA and circRNA dysregulation in several thyroid neoplasms and assess their potential for use as diagnostic and prognostic biomarkers.

Homocysteine and Hyperhomocysteinaemia.

Homocysteine (Hcy) is a thiol group containing the amino acid, which naturally occurs in all humans. Hcy is degraded in the body through two metabolic pathways, while a minor part is excreted through kidneys. The chemical reactions that are necessary for degradation of Hcy require the presence of folic acid, vitamins B6 and B12. Consequently, the level of the total Hcy in the serum is influenced by the presence or absence of these vitamins. An elevated level of the Hcy, hyperhomocysteinemia (HHcy) and homocystinuria is connected with occlusive artery disease, especially in the brain, the heart, and the kidney, in addition to venous thrombosis, chronic renal failure, megaloblastic anemia, osteoporosis, depression, Alzheimer's disease, pregnancy problems, and others. Elevated Hcy levels are connected with various pathologies both in adult and child population. Causes of HHcy include genetic mutations and enzyme deficiencies in 5, 10-methylenetetrahydrofolate reductase (MTHFR) methionine synthase (MS), and cystathionine ß-synthase (CßS). HHcy can be caused by deficiencies in the folate, vitamin B12 and to a lesser extent, deficiency in B6 vitamin what influences methionine metabolism. Additionally, HHcy can be caused by the rich diet and renal impairment. This review presents literature data from recent research related to Hcy metabolism and the etiology of the Hcy blood level disorder. In addition, we also described various pathological mechanisms induced by hereditary disturbances or nutritional influences and their association with HHcy induced pathology in adults and children and treatment of these metabolic disorders.

Interaction of Au(iii) and Pt(ii) complexes with Na/K-ATPase: experimental and theoretical study of reaction stoichiometry and binding sites.

The present paper deals with investigation of the interaction between selected simple structure Au(iii) ([AuCl4]-, [AuCl2(dmso)2]+, [AuCl2(bipy)]+) and Pt(ii) ([PtCl2(dmso)2]) complexes with Na/K-ATPase as the target enzyme, using an experimental and theoretical approach. Reaction stoichiometries and binding constants for these enzyme/complex systems were determined, while kinetic measurements were used in order to reveal the type of inhibition. Based on the results obtained by quantum mechanical calculations (electrostatic surface potential (ESP), volume and surface of the complexes) the nature of the investigated complexes was characterized. By using the solvent accessible surface area (SASA) applied on specific inhibitory sites (ion channel and intracellular domains) the nature of these sites was described. Docking studies were used to determine the theoretical probability of the non-covalent metal binding site positions. Inhibition studies implied that all the investigated complexes decreased the activity of the enzyme while the kinetic analysis indicated an uncompetitive mode of inhibition for the selected complexes. Docking results suggested that the main inhibitory site of all these complexes is located in the ion translocation pathway on the extracellular side in the E2P enzyme conformation, similar to the case of cardiac glycosides, specific Na/K-ATPase inhibitors. Also, based on our knowledge, the hydrolyzed forms of [AuCl4]- and [PtCl2(dmso)2] complexes were investigated for the first time by theoretical calculations in this paper. Thereby, a new inhibitory site situated between the M2 and M4 helices was revealed. Binding in this site induces conformational changes in the enzyme domains and perturbs the E1-E2P conformational equilibrium, causing enzyme inhibition.

Protein subunit interfaces: A statistical analysis of hot spots in Sm proteins.

The distinguishing property of Sm protein associations is very high stability. In order to understand this property, we analyzed the interfaces and compared the properties of Sm protein interfaces with those of a test set, the Binding Interface Database (BID). The comparison revealed that the main differences between the interfaces of Sm proteins and those of the BID set are the content of charged residues, the coordination numbers of the residues, knowledge-based pair potentials, and the conservation scores of hot spots. In Sm proteins, the interfaces have more hydrophobic and fewer charged residues than the surfaces, which is also the case for the BID test set and other proteins. However, in the interfaces, the content of charged residues in Sm proteins (26%) is substantially larger than that in the BID set (22%). Hot spots are residues that make up a small fraction of the interfaces, but they contribute most of the binding energy. These residues are critical to protein-protein interactions. Analyses of knowledge-based pair potentials of hot spot and non-hot spot residues in Sm proteins show that they are significantly different; their mean values are 31.5 and 11.3, respectively. In the BID set, this difference is smaller; in this case, the mean values for hot spot and non-hot spot residues are 20.7 and 12.4, respectively. Hence, the pair potentials of hot spots differ significantly for the Sm and BID data sets. In the interfaces of Sm proteins, the amino acids are tightly packed, and the coordination numbers are larger in Sm proteins than in the BID set for both hot spots and non-hot spots. At the same time, the coordination numbers are higher for hot spots; the average coordination number of the hot spot residues in Sm proteins is 7.7, while it is 6.1 for the non-hot spot residues. The difference in the calculated average conservation score for hot spots and non-hot spots in Sm proteins is significantly larger than it is in the BID set. In Sm proteins, the average conservation score for the hot spots is 7.4. Hot spots are surrounded by residues that are moderately conserved (5.9). The average conservation score for the other interface residues is 5.6. The conservation scores in the BID set do not show a significant distinction between hot and non-hot spots: the mean values for hot and non-hot spot residues are 5.5 and 5.2, respectively. These data show that structurally conserved residues and hot spots are significantly correlated in Sm proteins.