Cross-Effects in Folding and Phase Transitions of hnRNP A1 and C9Orf72 RNA G4 In Vitro.

Abnormal intracellular phase transitions in mutant hnRNP A1 may underlie the development of several neurodegenerative diseases. The risk of these diseases increases upon repeat expansion and the accumulation of the corresponding G-quadruplex (G4)-forming RNA, but the link between this RNA and the disruption of hnRNP A1 homeostasis has not been fully explored so far. Our aim was to clarify the mutual effects of hnRNP A1 and C9Orf72 G4 in vitro.

Effects of Progesterone and Selective Ligands of Membrane Progesterone Receptors in HepG2 Cells of Human Hepatocellular Carcinoma.

Progesterone exerts multiple effects in different tissues through nuclear receptors (nPRs) and through membrane receptors (mPRs) of adiponectin and progestin receptor families. The effect of progesterone on the cells through different types of receptors can vary significantly. At the same time, it affects the processes of proliferation and apoptosis in normal and tumor tissues in a dual way, stimulating proliferation and carcinogenesis in some tissues, suppressing them and stimulating cell death in others.

Hepatitis Delta Virus Antigens Trigger Oxidative Stress, Activate Antioxidant Nrf2/ARE Pathway, and Induce Unfolded Protein Response.

Hepatitis delta virus (HDV) is a viroid-like satellite that may co-infect individuals together with hepatitis B virus (HBV), as well as cause superinfection by infecting patients with chronic hepatitis B (CHB). Being a defective virus, HDV requires HBV structural proteins for virion production. Although the virus encodes just two forms of its single antigen, it enhances the progression of liver disease to cirrhosis in CHB patients and increases the incidence of hepatocellular carcinoma.

Aberrant Splicing of Impairs Beta-Cell Differentiation and Proliferation by ER Stress in the Isogenic iPSC Model of Neonatal Diabetes.

One of the causes of diabetes in infants is the defect of the insulin gene (INS). Gene mutations can lead to proinsulin misfolding, an increased endoplasmic reticulum (ER) stress and possible beta-cell apoptosis. In humans, the mechanisms underlying beta-cell failure remain unclear.

Subtype of Neuroblastoma Cells with High KIT Expression Are Dependent on KIT and Its Knockdown Induces Compensatory Activation of Pro-Survival Signaling.

Neuroblastoma (NB) is a pediatric cancer with high clinical and molecular heterogeneity, and patients with high-risk tumors have limited treatment options. Receptor tyrosine kinase KIT has been identified as a potential marker of high-risk NB and a promising target for NB treatment. We investigated 19,145 tumor RNA expression and molecular pathway activation profiles for 20 cancer types and detected relatively high levels of expression in NB.

Identification of cell type-specific correlations between ERK activity and cell viability upon treatment with ERK1/2 inhibitors.

Increased MAPK signaling is a hallmark of various cancers and is a central regulator of cell survival. Direct ERK1/2 inhibition is considered a promising approach to avoid ERK1/2 reactivation caused by upstream kinases BRAF, MEK1/2, and KRAS, as well as by receptor tyrosine kinase inhibitors, but the dynamics and selectivity of ERK1/2 inhibitors are much less studied compared with BRAF or MEK inhibitors. Using ERK1/2 and downstream kinase ELK1 reporter cell lines of lung cancer (H1299; NRAS), colon cancer (HCT-116; KRAS), neuroblastoma (SH-SY5Y), and leukemia (U937), we examined the relationship between ERK inhibition and drug-induced toxicity for five ERK inhibitors: SCH772984, ravoxertinib, LY3214996, ulixertinib, and VX-11e, as well as one MEK inhibitor, PD0325901.

A Founder Mutation in the POMC 5'-UTR Causes Proopiomelanocortin Deficiency Through Splicing-Mediated Decrease of mRNA.

Context: The syndrome of adrenal insufficiency, obesity, and red hair is a rare autosomal recessive disorder. The majority of disease-causing variants associated with the syndrome are located in the coding region of the POMC gene.

Objective: This work describes 7 unrelated patients who shared a novel homozygous mutation in the 5'-untranslated region (UTR) of the POMC gene and functionally characterize this novel variant.

Cytotoxic Effects of the Selective Ligands of Membrane Progesterone Receptors in Human Pancreatic Adenocarcinoma Cells BxPC3.

Progesterone and its synthetic analogues act on cells through different types of receptors, affecting proliferation and apoptosis. These compounds exert their effect through the nuclear receptors and the insufficiently studied membrane progesterone receptors (mPRs) belonging to the progestin and adiponectin Q receptor (PAQR) family. We have identified two selective ligands of mPRs that activate only this type of progesterone receptors - 19-hydroxypregn-4-en-20-one (LS-01) and 19-hydroxy-5β-pregn-3-en-20-one (LS-02).

[Alternative Variants of Pax4 Human Transcription Factor: Comparative Transcriptional Activity].

MODY is a group of genetically and clinically heterogeneous forms of diabetes characterized by auto-somal dominant inheritance and is subdivided in 13 subtypes dependent on the gene involved. The subtype MODY9 is a very rare form caused by mutations in the gene encoding the PAX4 transcription factor which is engaged in differentiation of pancreatic beta-cells. PAX4 contains two DNA-binding domains-Paired and Homeo.

Minigene splicing assessment of 20 novel synonymous and intronic glucokinase gene variants identified in patients with maturity-onset diabetes of the young.

The next-generation sequencing (NGS) has become a routine method for diagnostics of inherited disorders. However, assessment of the discovered variants may be challenging, especially when they are not predicted to change the protein sequence. Here we performed a functional analysis of 20 novel or rare intronic and synonymous glucokinase (GCK) gene variants identified by targeted NGS in 1,130 patients with maturity-onset diabetes of the young.

Immunomodulatory effects of progesterone and selective ligands of membrane progesterone receptors.

Progesterone (P4) and its analogues regulate various reproductive processes, such as ovulation, implantation, pregnancy maintenance and delivery. In these processes, an important role is played by the immune cells recruited to the female reproductive organs and tissues, where they are exposed to the action of P4. Progestins regulate cellular processes, acting through nuclear steroid receptors (nSRs), membrane P4 receptors (mPRs), and through the sensors.

Agonistic and Antagonistic Effects of Progesterone Derivatives on the Transcriptional Activity of Nuclear Progesterone Receptor B in Yeast Model System.

Identification of progesterone selective agonists and antagonists that act through one of the nuclear progesterone receptor isoforms is of particular importance for the development of tissue-specific drugs in gynecology and anticancer therapy. Fourteen pregna-D'- and pregna-D'-pentarane progesterone derivatives with 16α,17α-cycloalkane groups and two progesterone 3-deoxyderivatives were examined for their ability to regulate transcriptional activity of human nuclear progesterone receptor isoform B (nPR-B) expressed in Saccharomyces cerevisiae yeast. Transcriptional activity of nPR-B was measured from the expression of the β-galactosidase reporter gene with a hormone-responsible element in the promoter.

A Novel Mutation in the Critical P-Box Residue of Steroidogenic Factor-1 Presenting with XY Sex Reversal and Transient Adrenal Failure.

Background: Although the importance of steroidogenic factor-1 (SF1, NR5A1) for adrenal development is supported by numerous in vitro and in vivo studies, cases of SF1 deficiency associated with adrenal failure are exceptionally rare. The first human NR5A1 mutation was a heterozygous de novo p.G35E variant identified in a patient with disorder of sex development (DSD) 46,XY and primary adrenal insufficiency.

Cysteine residues 244 and 458-459 within the catalytic subunit of Na,K-ATPase control the enzyme's hydrolytic and signaling function under hypoxic conditions.

Our previous findings suggested that reversible thiol modifications of cysteine residues within the actuator (AD) and nucleotide binding domain (NBD) of the Na,K-ATPase may represent a powerful regulatory mechanism conveying redox- and oxygen-sensitivity of this multifunctional enzyme. S-glutathionylation of Cys244 in the AD and Cys 454-458-459 in the NBD inhibited the enzyme and protected cysteines' thiol groups from irreversible oxidation under hypoxic conditions. In this study mutagenesis approach was used to assess the role these cysteines play in regulation of the Na,K-ATPase hydrolytic and signaling functions.

[Role of pre-mRNA secondary structures in the regulation of alternative splicing].

Alternative splicing of pre-mRNA is one of the main mechanisms regulating gene expression that generates multiple transcripts from one gene. The review considers the specific role that intramolecular secondary structures arising through the interaction of distant complementary regions of introns play in regulating alternative splicing. Examples where aberrant splicing associated with hereditary disorders is corrected by altering the pre-mRNA secondary structures are described.

Late Diagnosis of POMC Deficiency and In Vitro Evidence of Residual Translation From Allele With c.-11C>A Mutation.

Context: Loss-of-function mutations in the POMC gene are associated with a syndrome with the characteristics of adrenal insufficiency, obesity, and red hair. We describe here a case of pro-opiomelanocortin (POMC) deficiency in which adrenal insufficiency was not treated until the fourth year of life. One of the disease-causative POMC mutations was characterized in vitro using a unique approach.

Progesterone inhibits proliferation and modulates expression of proliferation-Related genes in classical progesterone receptor-negative human BxPC3 pancreatic adenocarcinoma cells.

Recent studies suggest that progesterone may possess anti-tumorigenic properties. However, a growth-modulatory role of progestins in human cancer cells remains obscure. With the discovery of a new class of membrane progesterone receptors (mPRs) belonging to the progestin and adipoQ receptor gene family, it becomes important to study the effect of this hormone on proliferation of tumor cells that do not express classical nuclear progesterone receptors (nPRs).

Hepatitis C virus: The role of N-glycosylation sites of viral genotype 1b proteins for formation of viral particles in insect and mammalian cells.

Hepatitis C virus (HCV) is characterized by considerable genetic variability and, as a consequence, it has 6 genotypes and multitude of subtypes. HCV envelope glycoproteins are involved in the virion formation; the correct folding of these proteins plays the key role in virus infectivity. Glycosylation at certain sites of different genotypes HCV glycoproteins shows substantial differences in functions of the individual glycans (Goffard et al.

[Receptor tyrosine kinase KIT may regulate expression of genes involved in spontaneous regression of neuroblastoma].

Hallmark of neuroblastoma is an ability of this malignant tumor to undergo spontaneous regression or differentiation into benign tumor during any stage of the disease, but it is little known about mechanisms of these phenomena. We studied effect of receptor tyrosine kinase receptor KIT on expression of genes, which may be involved in tumor spontaneous regression. Downregulation of KIT expression by RNA interference in SH-SY5Y cells causes suppression of neurotrophin receptor NGFR expression that may promote the loss of sensibility of cells to nerve growth factors, also it causes upregulation of TrkA receptor expression which can stimulate cell differentiation or apoptosis in NGF dependent manner.

Regulation of Human Adenovirus Replication by RNA Interference.

Adenoviruses cause a wide variety of human infectious diseases. Adenoviral conjunctivitis and epidemic keratoconjunctivitis are commonly associated with human species D adenoviruses. Currently, there is no sufficient or appropriate treatment to counteract these adenovirus infections.

[Glucokinase and glucokinase regulatory proteins as molecular targets for novel antidiabetic drugs].

The impairment of glucose homeostasis leads to hyperglycemia and type-2 diabetes mellitus. Glucokinase (GK), an enzyme that catalyzes the conversion of glucose to glucose-6-phosphate in pancreatic ß-cells, liver hepatocytes, specific hypothalamic neurons, and intestine enterocytes, is a key regulator of glucose homeostasis. In hepatocytes, GK controls the glucose uptake and glycogen synthesis and inhibits the glucose synthesis via the gluconeogenesis pathway.

The role of HCV e2 protein glycosylation in functioning of virus envelope proteins in insect and Mammalian cells.

The hepatitis C virus (HCV) envelope proteins E1 and E2, being virion components, are involved in the formation of infectious particles in infected cells. The detailed structure of the infectious particle of HCV remains poorly understood. Moreover, the virion assembly and release of virions by the cell are the least understood processes.

[DAX1-unusual member of nuclear receptors superfamily with diverse functions].

Nuclear receptors (NRs) are ligand-activated transcription factors that play an important role in metabolism, homeostasis, differentiation and development regulation. NRs are also involved in pathogenesis of various diseases. For most of NRs natural ligands are known.