Acta Naturae最新文献

Cancer is the second leading cause of death worldwide, after cardiovascular disorders. One of the main constraints of anticancer agents is their limited water solubility, which complicates preclinical in vivo studies. In this work, we propose a versatile approach for stabilizing hydrophobic antitumor agents using liposomes based on natural phospholipids. The efficacy of the method is demonstrated for hydrophobic 1-tridecyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline, a promising tetrahydroisoquinoline derivative with proven antitumor activity against lymphoid and epithelial cancer cells. We show that the liposomal formulation ensures drug stability in aqueous media. Modification of the liposome surface with a HER2-specific non-immunoglobulin module strongly improved targeting efficiency. The targeting index differed markedly between cells with low versus high HER2 expression levels (3.02 and 18.98, respectively), demonstrating that the targeted liposomal formulation exerts a substantially enhanced cytotoxicity against HER2-overexpressing cells. The proposed liposomal platform can also be utilized to deliver other hydrophobic anticancer drugs.

Alzheimer's disease (AD) is a common neurodegenerative disorder associated with the dysfunction of nicotinic acetylcholine receptors (nAChRs). The function of nAChRs is normally regulated by endogenous ligands, such as acetylcholine and three-finger proteins belonging to the Ly6/uPAR family. However, information on the involvement of these proteins in the pathogenesis of AD is lacking. In this study, by using a bioinformatic analysis, we identified increased mRNA levels of Ly6/uPAR proteins (Lynx1, Lynx2, SLURP-1, Ly6G6E, etc.) in the entorhinal, temporal, and frontal cortex in AD patients with neurodegenerative symptoms, as well as an increase in the mRNA level of Ly6E in the hippocampus in patients with asymptomatic AD. Furthermore, in the cortex and cerebellum, we identified multidirectional changes in the mRNA expression of different nAChR subunits and regulators of inflammation (CD59, CD177, Lypd2, Lypd4, and Lypd8) and metabolism (GPIHBP and Ly6D), also belonging to the Ly6/uPAR protein family. By using immunostaining and Western blotting, we confirmed increased protein levels of Lynx1, Lynx2, and the β2 nAChR subunit in the cingulate gyrus adjacent to the entorhinal cortex in patients with AD, as well as decreased protein levels of the α4 and α7 nAChR subunits. These findings point to complex dysregulation of the cholinergic system in the AD brain at the expression levels both of the individual nAChR subtypes and its natural modulators belonging to the Ly6/uPAR family.

Antibody-drug conjugates (ADCs) have revolutionized chemotherapy, allowing it to shift from systemic cytotoxic chemotherapy to specific targeting of cells expressing tumor antigens. ADCs thus offer increased therapeutic efficacy and lower toxicity compared to conventional chemotherapy. Bioconjugation of a highly active therapeutic agent to an antibody is one of the key steps in producing ADCs. The most advanced ADC technologies are based on the production of stoichiometrically homogeneous bioconjugates. Enzymatic modification of antibodies using microbial transglutaminase (mTGase) enables the production of biopharmaceuticals with standardized pharmacokinetic, physicochemical, and therapeutic properties. However, side reactions catalyzed by free mTGase in solution reduce the yield and purity of ADCs. In this study, we evaluated the efficiency of various approaches to mTGase immobilization: streptavidin-biotin interaction, the use of an epoxy-activated polymer, and self-immobilization of mTGase. The highest bioconjugation activity was observed when using streptavidin-modified magnetic particles and biotinylated mTGase. However, mTGase self-immobilization on AH-Sepharose 4B or immobilization using epoxy-activated agarose ensures comparable efficiency in enzymatic antibody modification and is the most rational route from the perspective of process scalability. We believe that the proposed approaches are of high practical significance, opening up avenues for optimizing enzymatic bioconjugation and scaling up the production of stoichiometric ADCs for targeted cancer immunotherapy.

 significant impact on the pathogenesis of viral infections by acting as both positive and negative regulators of viral gene expression. This review summarizes the available data on lncRNAs associated with human immunodeficiency virus type 1 (HIV-1). LncRNAs can regulate both the active replication cycle and the latent phase of the HIV-1 infection, during which the integrated proviral DNA remains transcriptionally silent. Moreover, lncRNAs may serve as diagnostic markers and are potential therapeutic targets. A deeper understanding of the intricate interactions between lncRNAs and HIV-1 is essential for developing innovative treatments for the HIV infection and the associated acquired immunodeficiency syndrome (AIDS).

The Clostridioides difficile infection (CDI) is one of the most common nosocomial infections around. The key pathogenicity factors of this bacterium include the toxins A and B that cause the disease symptoms. Neutralization of these toxins is one of the promising strategies for CDI treatment. Here, we isolated a panel of single-domain antibodies to the toxin B CROPs domain. Two antibodies, TB5A7 and TB4A8, exhibiting potent neutralizing activity were modified to produce homodimeric forms. The TB5A7 and TB4A8 dimers were characterized by enhanced neutralizing activity and protected animals from a toxin B lethal challenge. The obtained antibodies may be used to develop new agents for CDI treatment.

Genital lichen sclerosus (GLS) is a chronic inflammatory dermatosis that affects the genital skin. Despite different clinical manifestations, the pathogenesis of GLS in men and women is believed to be common and is attributed to a combination of autoimmune and genetic factors. In this study, we compared the transcriptomic profiles of penile (mGLS) and vulvar lichen sclerosus (VLS), aiming to identify commonly deregulated genes. We observed a substantial heterogeneity in the transcriptomic signatures in mGLS samples, which is driven by different compositions of immune infiltrates. In mGLS, gene expression signatures strongly indicate epidermis dysfunction and overexpression of the epithelial inflammation marker Keratin 6 (KRT6) and chitinase CHIT1. No significant changes in the expression levels of known GLS markers, such as VIM, CTNNB1, LGALS7 and ECM1, were detected. However, significant changes in the expression levels of the genes associated with autoimmune diseases and the genes upregulated in squamous cell carcinoma, including TNF, CCNB1 and RUNX3, were observed. There was no enrichment in the polyU/UC insertions that were reported previously. Instead, we have identified a long non-coding RNA DRAIC with a high coding potential that is commonly upregulated in mGLS and VLS. Taken together, our results provide a comprehensive picture of the shared transcriptomic signatures, including novel biomarkers and potential therapeutic targets.

Macrophage dysfunction is a key pathogenetic mechanism in the progression of a wide range of human chronic inflammation conditions, including atherosclerosis, rheumatoid arthritis, and metabolic disorders. The CDK8 and CDK19 paralogous kinases, the subunits of the Mediator complex acting as transcription regulators, are essential modulators of the inflammatory response. This study addresses the role of CDK8/19 kinases in the macrophage inflammatory response via multiple mechanisms: activation of pro- and anti-inflammatory genes and surface markers, STAT1 pathway modulation, activation of glycolytic cascade genes, regulation of the dynamics of lipid inclusions, and phagocytic activity. Experiments have shown that CDK8 and CDK19 may exhibit functional divergence. Cdk19 knockout reveals that CDK19 plays a role in the suppression of the M1 response, as well as the regulation of lipid homeostasis and phagocytosis. Double Cdk8/19 knockout macrophages are characterized by an exacerbated anti-inflammatory response while preserving normal lipid accumulation and phagocytosis levels. Inhibition of CDK8/19 kinase activity reproduces these effects only partially, suggesting that both kinase-dependent and kinase-independent mechanisms of action exist. The identified effects reveal previously unknown regulation mechanisms of macrophage immunometabolism. Modulation of CDK8 and CDK19 activity can become a novel therapeutic target for a wide range of chronic inflammatory conditions and metabolic disorders associated with macrophage dysfunction.

The analysis of protein evolutionary relationships is of both theoretical and practical significance. Identifying and characterizing evolutionary relationships between the components of protein complexes and metabolic enzymes fosters a deeper understanding of their evolutionary history and molecular evolution. The existence of related enzymes makes the annotation of new sequences complicated, since this process relies heavily on accurately determining the protein family classification of the sequence being analyzed. Clusters of Orthologous Groups (COGs) are widely used for the classification of prokaryotic proteins. COGs are constructed based on the occurrence of the respective protein-coding genes within complete genomes. Previously, we introduced COGcollator, a tool designed to visualize the relatedness between COGs by analyzing the hits of their profile HMMs (Hidden Markov Models). This paper presents an update of the COGcollator web service. It is based on the latest version of the COG database and features a completely new interface and additional functionalities. To demonstrate the capabilities of our tool and the validity of the data, we present the COGcollator results for the subunits of NADH:quinone oxidoreductase type 1 (NDH-1), a homologue of the mitochondrial complex I, as the evolutionary relationships of NDH-1 with other protein complexes have been extensively documented in the literature. The web service is available free of charge without registration at https://boabio.belozersky.msu.ru/en/COGcollator. Through the web service interface, users can access pre-calculated COGcollator results for 4,972 COGs and download their respective profile HMMs.

Genetic variation in the genes involved in the maintenance of cellular homeostasis may influence susceptibility to type 2 diabetes (T2D). However, the nature of the interplay among these loci and their prognostic value remains unclear. In this study, we analyzed variants in the FOXO3A, FOXO3, FOXO1, HMOX1, and SIRT1 genes. The HMOX1 rs2071746*T/T genotype was associated with an increased risk of T2D (OR = 1.36, PFDR = 0.030), whereas the FOXO1 rs9549240 (OR = 0.52, PFDR = 0.002) and SIRT1 rs3758391 (OR = 0.80, PFDR = 0.015) genotypes exhibited a protective effect. We detected nonlinear interactions, including FOXO1 rs9549240*G + SIRT1 rs3758391*T + SIRT1 rs7895833*A and HMOX1 rs2071746*A + SIRT1 rs3758391*T + SIRT1 rs7895833*A, with significant synergistic effects (SF = 3.19 and 2.56, P < 0.03). Models incorporating these interactions achieved an AUC of 69.8%, which increased to 86.2% when combined with age, sex, and the body mass index. These findings suggest that interactions between the pathways regulating oxidative stress and metabolism may contribute to the genetic predisposition to T2D.

Cancer remains a critical public health challenge, and developing novel approaches to cancer therapy is highly relevant. Targeted tumor therapy using antibody-drug conjugates (ADCs) has already demonstrated its efficacy in multiple tumors. Ganglioside GD2 is a promising target for ADC development. However, its functional properties, which are important for the cytotoxicity of ADCs, remain poorly understood. This study focuses on the mechanisms of receptor-mediated endocytosis for the conjugate formed between the anti-GD2 antibody ch14.18 and monomethyl auristatin E (MMAE), as well as the approaches for modulating this process using endocytosis inhibitors. Our findings demonstrate that anti-GD2 ADCs are efficiently internalized into tumor cells through various endocytic pathways, including the clathrin- and caveolin-mediated pathways, as well as macropinocytosis. The efficiency of ADC accumulation directly correlates with the level of GD2 expression on the tumor cell surface and is determined by the properties of the parental antibody, independent of the cytotoxic payload. Endocytosis inhibitors can modulate the functional properties of anti-GD2 ADCs, either decreasing or increasing the cytotoxic effects of the conjugates in GD2-positive cells. Nystatin, a specific inhibitor of caveolin-mediated endocytosis, increased ADC accumulation in cells and reduced the IC₅₀ 1.5- to 2.5-fold depending on the cell line. Although administration of nystatin together with anti-GD2 ADCs did not enhance tumor growth inhibition compared to ADC monotherapy in the GD2- positive mouse tumor model, further optimization of combination therapy conditions aimed at enhancing receptor-mediated endocytosis is a promising strategy for potentiating the antitumor effects of anti-GD2 ADCs.