Acta Naturae

In this analytical review, we explore the potential impact of the rapid proliferation of artificial intelligence (AI) tools on the biosphere and noosphere, suggesting that the trend may lead to a transformative event that could be termed “Human-AI integration.” We argue that this integration could give rise to novel lifeforms, associations, and hierarchies, resulting in competitive advantages and increased complexity of structural organizations within both the biosphere and noosphere. Our central premise emphasizes the importance of human-AI integration as a global adaptive response crucial for our civilization’s survival amidst a rapidly changing environment. The convergence may initially manifest itself through symbiotic, endosymbiotic, or other mutualistic relationships, such as domestication, contingent on the rate at which AI systems achieve autonomy and develop survival instincts akin to those of biological organisms. We investigate potential drivers of these scenarios, addressing the ethical and existential challenges arising from the AI-driven transformation of the biosphere and noosphere, and considering potential trade-offs. Additionally, we discuss the application of complexity and the balance between competition and cooperation to better comprehend and navigate these transformative scenarios.

Pyridoxal-5’-phosphate-dependent enzymes play a crucial role in nitrogen metabolism. Carbonyl compounds, such as O-substituted hydroxylamines, stand out among numerous specific inhibitors of these enzymes, including those of practical importance, because they react with pyridoxal-5’-phosphate in the active site of the enzymes to form stable oximes. O-substituted hydroxylamines mimic the side group of amino acid substrates, thus providing highly potent and specific inhibition of the corresponding enzymes. The interaction between D-amino acid transaminase from bacterium Haliscomenobacter hydrossis and 3-aminooxypropionic acid was studied in the present work. The structural and spectral analysis of the complex of this transaminase with 3-aminooxypropionic acid allowed us to clarify some features of the organization and functioning of its active site and illustrate one of the mechanisms of inhibition by the specific substrate, D-glutamic acid.

The increasing resistance of microorganisms to antibiotics makes it a necessity that we search for new antimicrobial agents. Due to their genetically encoded nature, peptides are promising candidates for new antimicrobial drugs. Lantipeptide andalusicin exhibits significant antimicrobial activity against Gram-positive bacteria, making it a promising scaffold for the development of DNA-encoded libraries of lantibiotics. In this study, the modification reaction of andalusicin by class III lanthionine synthetase AncKC was reconstructed in a heterologous Escherichia coli system. The results obtained open possibilities for creating novel peptide-based antimicrobial agents.

5ˊ-Noraristeromycin as a racemic mixture of enantiomers was found to exhibit a pronounced cytotoxic effect on leukemia cells; IC₅₀ for the Jurkat, K562, and THP-1 cell lines was 7.3, 1.3, and 3.7 μM, respectively. The general toxicity of 5'-noraristeromycin was studied in experiments on white mice upon single-dose intragastric administration; toxicometric parameters were determined, and the clinical and pathomorphological presentation of acute intoxication was studied. LD₅₀ of the substance was shown to be 63.2 (52.7÷75.8) mg/kg; LD₁₆, 44.7 mg/kg, and LD₈₄, 89.4 mg/kg. Administration of the substance at a dose within the studied dose range is accompanied by systemic damage to the internal organs and tissues of the experimental animals.

Low-grade gliomas are divided into two main genetic phenotypes based on the presence or absence of mutations in the isocitrate dehydrogenase (IDH) genes. The mutated IDH phenotype (IDHmut), in contrast to the wild-type phenotype (IDHwt), is characterized by a more positive response to pharmacological intervention and a significantly longer survival time. In this study, we analyzed the differential co-expression of 225,000 microRNA–mRNA pairs at the level of correlations between microRNA levels and their potential mRNA targets. Analysis of the associative relationships of individual representatives of the selected pairs revealed that the level of mRNAs encoded by the ELN, ARL4C, C9orf64, PLAT, and FKBP9 genes associated with aggressive progression of glioma was increased in the IDHwt group. Meanwhile, the levels of miRNA-182, miRNA-455, and miRNA-891a associated with the negative prognosis in glioma were generally increased in the IDHmut group. Most (16/21) of the detected 21 microRNA–mRNA pairs with a significant difference in regulation between the IDHwt and IDHmut glioma samples had a weak or moderate positive correlation in IDHmut samples and a negative correlation in IDHwt samples. Therefore, our findings indicate that glioma samples from the IDHmut group with a positive prognosis potentially have a significantly less pronounced ability to microRNA-mediated regulation. We further suggest that such physiological disorders can lead to reduced tumor viability, resulting in an increased ability of the host to resist the spread of a malignant transformation of this genetic phenotype.

Accumulation of neurotoxic aggregates of beta-amyloid peptides (Aβ) is a hallmark of Alzheimer’s disease (AD) progression. Post-translational modifications (PTMs) increase Aβ aggregation and cytotoxicity, and the content of specific Aβ proteoforms is elevated in senile plaques of AD patients. The pathophysiological mechanisms of aggregate formation and the role of Aβ proteoforms need thorough study both to understand the role played by specific processes in the initiation of neuronal degradation and to find effective preventive means of therapeutic action. The present work investigates the dynamics of accumulation of phosphorylated serine-8 proteoform Aβ (pSer8-Aβ) using the 5xFAD mouse amyloid model. Aβ samples from human cerebrospinal fluid (CSF) and brain were also investigated. Western blot studies using 1E4E11 and 4G8 antibodies showed that accumulation of pSer8-Aβ in mouse brain starts as early as at the age of 3 months and reaches a maximum by the age of 14–17 months, which is generally similar to the dynamics of accumulation of the total pool of Aβ peptides. The pSer8-Aβ level in human CSF in AD patients can reach ~ 1–10% of the total amount of Aβ. Mass spectrometric analysis showed that Aβ phosphorylation by the Ser8, Tyr10, and Ser26 residues in brain tissues, as well as phosphorylation of the APP by Thr719 residue, is possible. These findings support the assumption that pSer8-Aβ proteoforms are involved in amyloidosis in AD.

Mammalian nucleotide excision repair (NER), known for its broad substrate specificity, is responsible for removal of bulky lesions from DNA. Over 30 proteins are involved in NER, which includes two distinct pathways: global genome NER and transcription-coupled repair. The complexity of these processes, the use of extended DNA substrates, and the presence of bulky DNA lesions induced by chemotherapy have driven researchers to seek more effective methods by which to assess NER activity, as well as to develop model DNAs that serve as efficient substrates for studying lesion removal. In this work, we conducted a comparative analysis of model DNAs containing bulky lesions. One of these lesions, N-[6-{5(6)-fluoresceinylcarbamoyl}hexanoyl]-3-amino-1,2-propanediol (nFluL), is known to be efficiently recognized and excised by NER. The second lesion, N-[6-{5(6)-fluoresceinylcarbamoyl}]-3-amino-1,2-propanediol (nFluS), has not previously been tested as a substrate for NER. To evaluate the efficiency of lesion excision, a 3’-terminal labeling method was employed to analyze the excision products. The results showed that nFluS is removed approximately twice as efficiently as nFluL. Comparative analyses of the effects of nFluL and nFluS on the geometry and thermal stability of DNA duplexes — combined with spectrophotometric and spectrofluorimetric titrations of these DNAs with complementary strands — were performed next. They revealed that the absence of an extended flexible linker in nFluS alters the interaction of the bulky fluorescein moiety with neighboring nitrogenous bases in double-stranded DNA. This absence is associated with the enhanced efficiency of excision of nFluS, making it a more effective synthetic analog for studying bulky-lesion removal in model DNA substrates.