Biochemistry (Moscow), Supplement Series A: Membrane and Cell Biology最新文献

This study characterizes extracellular vesicles (EVs) produced by multipotent mesenchymal stromal cells (MMSCs) in culture medium. The vesicles isolated by centrifugation contained proteins specific to exosomes and had a characteristic size. The effects of vesicles produced by MMSC (MMSC-EVs) on kidney cells under normal and pathological conditions were analyzed. MMSC-EVs increased the proliferation rate of renal epithelial cells after damage caused by oxygen-glucose deprivation. The microRNA expression profile in MMSC-EVs showed that both damage-aggravating and protective microRNAs were highly expressed in them. The overall effect of MMSC-EVs on kidney cells appears to result from the complex interactions of protein signals and the regulatory effects of microRNAs.

Modular nanotransporters are a drug delivery system developed for targeted cancer treatment. Modular nanotransporters are macromolecules made up of several transport modules. They can transfer active principles to susceptible compartments of cancer target cells. Their endosomolytic module promotes pH-dependent pore formation in endosomal membranes, ensuring the modular nanotransporters endosome escapes into the cytosol of the target cell following receptor-mediated endocytosis. The membranolytic activity of modular nanotransporters can be assessed by their ability to cause leakage of phosphatidylcholine liposomes loaded with a fluorescent dye in a concentration that causes fluorescence self-quenching. To study the kinetics of the process, we used sulfo-cyanine dye, the fluorescence of which does not depend on pH. Using this approach, we investigated the membranolytic kinetics of two modular nanotransporters for targeted delivery of drugs within cells overexpressing the epidermal growth factor receptor. A modular nanotransporter with an endosomolytic module at the N-terminus of the molecule has significantly faster kinetics compared to a modular nanotransporter that has a ligand module at the N-terminus. Our results helped us better understand the early stages of the interaction of modular nanotransporters with the phospholipid bilayer and identified the settings that are more suitable for further investigation.

Aging is associated with an increased risk of cardiovascular diseases (CVDs), which are among the leading causes of mortality in elderly populations. Natural bioactive compounds have shown promise in mitigating cardiovascular risks. This study investigates luteolin, a flavonoid from Ginkgo biloba, known for its antioxidant, anti-inflammatory, and vasorelaxant properties, in managing age-related cardiovascular diseases (ACVDs). An integrated approach combining network pharmacology and molecular docking analysis was adopted to identify the pharmacodynamic properties and specific protein targets of luteolin in ACVD. Among 60 bioactive compounds from Ginkgo biloba screened, luteolin was selected based on its known cardioprotective properties. Through databases like DisGeNET, OMIM and GeneCards, 2,305 ACVD-related target proteins were identified, with 42 targets overlapping with luteolin. Network pharmacology analysis using STRING and Cytoscape revealed key proteins such as TP53, AKT1, JUN, TNF, and IL6 as hub protein within the protein-protein interaction network. Pathway enrichment analysis highlighted significant pathways, including the AGE-RAGE and IL-17 signaling pathways, lipid and atherosclerosis pathway, linking luteolin’s effects to mechanisms central to ACVDs. Molecular docking studies further demonstrated strong binding affinities between luteolin and key targets such as MAPK3, MAPK8, JUN, TP53 and AKT1 suggesting effective modulation of pathways involved in inflammation, oxidative stress, and apoptosis. These findings suggest that luteolin could serve as a multifaceted therapeutic agent for ACVD by targeting inflammatory and signaling pathways.

Dihydropyridine receptors (DHPR) participate in changes of the membrane potential during muscle unloading. We used nifedipine, a dihydropyridine derivative and Ca²⁺ antagonist, to study the role of L‑type Ca²⁺ channels (Cav1.1, DHPR) in regulation of energy and Ca²⁺ metabolism and impact on functional properties of m. soleus during unloading. Male rats were divided into 3 groups (n = 16 in each group): vivarium control with placebo (C), 3-day hindlimb suspension with placebo (HS), and 3-day hindlimb suspension with intraperitoneal administration of the nifedipine (N). It was found that nifedipine administration during hindlimb suspension produced the following effects: (1) it decreased the ATP accumulation; (2) prevented the reduction of the maximum force of a single contraction and the time of contraction, and (3) prevented the increase in the content of intramitochondrial and myoplasmic calcium. Thus, DHPR participates in energy and Ca²⁺ metabolism and affects the functional properties of muscles.

The analysis of multi-atomic systems from the first principles is highly computationally intensive, therefore it requires the finding of integral degrees of freedom. We propose the usage of the lattice Abelian Higgs model for the study of protein structure and dynamics. At the first step we have introduced heterogeneous external electric field in this model and have shown how this field affected the tertiary protein structure. At the second step we found the form of external field corresponding to native protein structure with experimental accuracy. We believe that this approach will allow one to model protein dynamics depending on external conditions.

COVID-19 is a rapidly disseminating disease whose causative agent is severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite the high investigation pace and the status of the most studied virus there are still blank spots in the understanding of SARS-CoV-2 mechanism of entry into the host cell. The most important role in this process is played by the viral spike (S) protein, particularly its transmembrane (TM) domain, whereon structural data are quite contradictory. In this work, we present a fast and high-performance method of cell-free expression and purification of the wild-type TM domain of the S protein including juxtamembrane parts. The purified peptide was incorporated into membrane mimicking dodecyl phosphocholine (DPC) micelles and was assessed as appropriate for further structural and dynamic investigation in nuclear magnetic resonance (NMR) experiments. We discuss the possible influence of amino acid sequence mutations, expression and purification methods.

Whooping cough is a serious illness affecting young children. There are two main types of vaccines for whooping cough: cellular and acellular. We focused on studying the immune response to Bordetella pertussis based on the type of vaccination to uncover factors that affect vaccine effectiveness. It is worth noting that the immune response to Bordetella pertussis depends on many factors. In this study, we examine the role of the systemic T cell response. It was found that memory T cells react to components of the pertussis bacterium, and the strength of this response is independent of the vaccination type. In most donors, the T cell response to the inactivated bacterium was more robust than to gd15PtxS1 (genetically detoxified S1 subunit of pertussis toxin), a key ingredient in acellular vaccines. This indicates the existence of dominant epitopes beyond PT that elicit an immune response. Additionally, a bioinformatics analysis was conducted on the epitopes of various B. pertussis proteins, predicting their dominance based on HLA alleles and assessing the potential for cross-reactive T cell responses to other Bordetella species and human microbiota. These findings could help in the development of new vaccines against B. pertussis or in modifying existing vaccines to improve their efficacy and minimize side effects. These results may help in the development of new vaccines against B. pertussis or in the modification of vaccines to their efficacy and minimize side effects.

The hypothesis of the relationship between changes in the calcium throughput of dihydropyridine receptors (DHPR) and the accumulation of ATP and phosphoinositide 3-kinases (PI3) in the muscle during its unloading was checked. We also checked the PI3K signaling pathway involvement in the atrophic process regulation in skeletal muscles during their unloading. To do this, we inhibited DHPR and PI3K with nifedipine and with LY294002. We found that both sarcolemma-related units are involved in the regulation of ATP content, calcium signaling markers, and IP3 levels in the unloaded m. soleus. DHPR inhibition prevents ATP, Ca²⁺, and IP3 accumulation in soleus under unloading. PI3K inhibition reduces the degree of atrophy, ATP and IP3 content in muscle, and regulates the Ca-dependent signaling markers under tree day soleus unloading.

In bacteria and some eukaryotes, an important tool to respond to both external and internal signals is a two-component system, which is typically composed of a transmembrane receptor histidine kinase (RHK) and its cognate response regulator. While architecture and distribution of RHKs in prokaryotes are well-documented, their roles in eukaryotes, particularly in the green algae, remain less understood. Here, we analyzed the sequences and domain architectures of RHKs within the green algae clade Chlorophyta, in the class Chloropicophyceae, better characterized compared to other classes. Our study aims to deepen understanding and infer the biological roles of these proteins. Based on InterProScan results, we showed that rhodopsin-histidine kinases play a global role in the biology of the microalgae: they dominate among all RHKs, representing 57% of them. The length variation of RHKs does not have a discrete structure. Furthermore, we identified the most frequent domains and domain architectures in the proteins, with a notable discovery of a significant number of hybrid histidine kinases, where the sensory domain is a microbial rhodopsin protein. We demonstrate also that one-half of the identified rhodopsin-histidine kinases possess a catalytic domain of either adenylyl or guanylyl cyclase, making them potentially useful as optogenetic tools. In addition, it is shown that a significant part of RHKs in green algae contain not one but two REC-domains. These findings, along with previous reports, suggest that multiple REC-domains may support complex regulatory functions, possibly allowing condition-dependent responses. Our work may also help to understand better RHKs potential in optogenetics.