Acta Naturae

This review examines the potential applications of affibody molecules in various fields of biotechnology and clinical medicine. Consideration is given to the high affinity and specificity of affibody molecules for selected molecular targets, as well as their potential for the in vivo visualization of various malignant tumors. Significant attention is paid to preclinical and clinical studies of affibody conjugates with various radioisotopes for targeted radionuclide tumor imaging, which is particularly relevant in addressing challenges encountered during the diagnosis and treatment of these patients. Clinical trials demonstrate that radiopharmaceuticals are well-tolerated and effective for the assessment of tumor process prevalence and the determination of HER2/neu status in breast cancer patients, supporting further research.

The development of a symbiotic gut ecosystem is a crucial step in postnatal adaptation. The gut microbiome of very preterm infants is characterized by an overall instability, reduced microbial diversity, and a predominance of Gram-negative Proteobacteria, all factors associated with an increased risk of necrotizing enterocolitis (NEC). Short-chain fatty acids (SCFAs) are the key bacterial metabolites that are essential for maintaining intestinal homeostasis, supporting immune development, enhancing intestinal barrier integrity, and reducing inflammation. This review examines the role of gut microbiota and SCFAs in neonatal NEC, with a focus on potential diagnostic and therapeutic strategies. Clinical studies have consistently demonstrated a significant decrease in total SCFA levels and individual bacterial metabolites in preterm infants with NEC. This finding has been corroborated by various experimental models. Clarification of the role of SCFAs in NEC pathogenesis, determination of their diagnostic utility, and assessment of the feasibility of developing comprehensive pro- and postbiotic formulations require multi-center, multi-omics investigations that include a large cohort of very preterm infants.

Mitochondrial dysfunction is one of the pathogenetic mechanisms of neuronal damage during aging. The high energy dependence of neurons makes them particularly vulnerable to age-related changes accompanied by oxidative stress and impaired energy metabolism. The maintenance of a pool of functional mitochondria is regulated by mitophagy, which ensures the utilization of damaged organelles, thereby preventing the progression of mitochondrial dysfunction. Brain aging is accompanied by a reduced level of activity of metabolic processes, aggravated mitochondrial dysfunction, and an increased risk of developing neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. This review highlights the molecular and signaling pathways of mitophagy and its dysregulation during physiological and pathological aging, which is of particular interest for identifying pharmaceutical targets and developing potential therapies for neurodegenerative conditions.

Propionibacterium freudenreichii plays a crucial role in the production of Swiss-type cheeses; however, genomic variability among strains, which affects their technological traits, remains insufficiently explored. In this study, whole-genome sequencing and comparative analysis were performed on five industrial P. freudenreichii strains. Despite their overall high genomic similarity, the strains proved different in gas production and substrate metabolism. Phylogenetic analysis revealed a close relationship between strain FNCPS 828 and P. freudenreichii subsp. shermanii (z-score = 0.99948), with the latter being unable to reduce nitrates but being able to metabolize lactose. The narG gene encoding the nitrate reductase alpha subunit was detected in only one of the five analyzed strains ‒ FNCPS 828 ‒ and in 39% of previously described P. freudenreichii genomes, suggesting its potential as a marker of nitrate-reducing capability. Analysis of 112 genomes showed that the I‒G CRISPR‒Cas system was present in more than 90% of the strains, whereas the type I‒E system was found in approximately 25%. All the five study strains harbored the type I‒G system; strain FNCPS 3 additionally contained a complete type I‒E system with the highest number of CRISPR spacers, some of which matched previously published bacteriophage sequences. The most prevalent anti-phage defense systems included RM I, RM IV, AbiE, PD-T4-6, HEC-06, and ietAS. These findings highlight the genetic diversity of P. freudenreichii strains, which is of great importance in their industrial applications. The identification of narG as a potential marker of nitrate-reducing activity, along with detailed mapping of CRISPR‒Cas systems, boosts opportunities for the rational selection and engineering of starter cultures with tailored metabolic properties and increased resistance to bacteriophages.

Radiation therapy is a commonly used cancer treatment modality. However, its application is limited because of its toxicity to healthy tissue. The search for effective radioprotective agents remains one of the key goals of radiation oncology and radiobiology. This study focuses on experimental modeling of radiation injury in animals and the investigation of Dimephosphon radioprotective properties, a drug exhibiting anti-acidotic, antitumor, and antioxidant activities. It was shown that 14-day administration of the drug at a dose of 750 mg/kg after single-dose (5 Gy) irradiation of CD-1 mice resulted in a local radioprotective effect, reducing the severity of the radiation-induced injury to the intestinal epithelium and splenic capsule. The results of metabolomic screening revealed that the levels of the key metabolites responsible for antioxidant properties such as alpha-tocopherol, nicotinamide riboside, N-carbamoyl-L-aspartate, and adenylosuccinate were significantly increased, indicating that the Dimephosphon drug provides enhanced antioxidant protection.

Alzheimer’s disease, first described over a century ago, is currently among the most common neurodegenerative diseases whose significance is increasingly growing with the aging of populations. Throughout the entire period of its study, no remedies have been found that would be effective in treating – or at least significantly slowing – the pathological process, while being sufficiently safe. In this regard, significant attention is paid to the development and application of natural peptide drugs lacking side effects. The present study assessed the effect of the known neuroprotective peptide Semax and its derivative on the behavioral characteristics and development of amyloidosis in transgenic APPswe/PS1dE9/Blg mice acting as a model of Alzheimer’s disease. The open field, novel object recognition, and Barnes maze tests demonstrated that both Semax and its derivative improved cognitive functions in mice. Histological examination showed that these peptides reduced the number of amyloid inclusions in the cortex and hippocampus of the animals’ brains. These findings demonstrate the high potential of Semax and its derivatives when used to develop therapeutic and corrective strategies for Alzheimer’s disease.