Immunomodulatory and neurotropic activities of synthetic peptides in a model of brain injury in rats

Treatment of consequences of traumatic brain injury (TBI) remains one of the current problems of medicine. To increase the effectiveness of treatment of post-traumatic complications, various drugs are recommended, including the peptide with neuromodulatory activity Semax.The present study aims to determine the presence of neuro- and immunoprotective properties of the synthetic peptide PR5, composed of fragments of proline-rich antimicrobial peptides.The work was performed on male Wistar rats weighing 300-350 g. The “falling weight” model of mechanical brain injury was used, which mainly causes diffuse brain damage. The synthesized peptide PR5, composed of fragments of known proline-rich peptides of animal neutrophils, and the peptide preparation Semax in the form of a 1% aqueous solution were used. The drugs were administered intranasally 1 hour after TBI, then twice a day for 4 days at a dose of 100 mg/kg body weight. Control animals received physiological saline in the same regimen as the peptide preparations.TBI led to a significant decrease in body weight, but in rats receiving the peptide preparation Semax, the decrease in body weight was significantly less than in control animals, and the PR5 preparation completely prevented the decrease in body weight after TBI. After TBI, the proliferative activity of lymphocytes was suppressed and the cytotoxicity of NK cells decreased. In animals treated with peptide preparations, there was no significant suppression of NK cell cytotoxicity, and the proliferative activity of lymphocytes was restored to the level of control animals by day 14 after TBI. Both peptide preparations used contributed to higher locomotor activity, and in animals treated with the PR5 peptide, this type of activity reached the parameters of control animals. The reduction in freezing duration in groups treated with peptide preparations indicates the presence of a sedative effect.The peptide preparation PR5 was active in this series of experiments, showing immunotropic and neuroprotective activity comparable to the Semax preparation. Further studies aimed at confirming the identified types of activity of the peptide preparation PR5 may justify its prospects for clinical use as a new nootropic agent

Application of Antimicrobial Peptides of the Innate Immune System in Combination With Conventional Antibiotics—A Novel Way to Combat Antibiotic Resistance?

Rapidly growing resistance of pathogenic bacteria to conventional antibiotics leads to inefficiency of traditional approaches of countering infections and determines the urgent need for a search of fundamentally new anti-infective drugs. Antimicrobial peptides (AMPs) of the innate immune system are promising candidates for a role of such novel antibiotics. However, some cytotoxicity of AMPs toward host cells limits their active implementation in medicine and forces attempts to design numerous structural analogs of the peptides with optimized properties. An alternative route for the successful AMPs introduction may be their usage in combination with conventional antibiotics. Synergistic antibacterial effects have been reported for a number of such combinations, however, the molecular mechanisms of the synergy remain poorly understood and little is known whether AMPs cytotoxicy for the host cells increases upon their application with antibiotics. Our study is directed to examination of a combined action of natural AMPs with different structure and mode of action (porcine protegrin 1, caprine bactenecin ChBac3.4, human alpha- and beta-defensins (HNP-1, HNP-4, hBD-2, hBD-3), human cathelicidin LL-37), and egg white lysozyme with varied antibiotic agents (gentamicin, ofloxacin, oxacillin, rifampicin, polymyxin B, silver nanoparticles) toward selected bacteria, including drug-sensitive and drug-resistant strains, as well as toward some mammalian cells (human erythrocytes, PBMC, neutrophils, murine peritoneal macrophages and Ehrlich ascites carcinoma cells). Using “checkerboard titrations” for fractional inhibitory concentration indexes evaluation, it was found that synergy in antibacterial action mainly occurs between highly membrane-active AMPs (e.g., protegrin 1, hBD-3) and antibiotics with intracellular targets (e.g., gentamicin, rifampcin), suggesting bioavailability increase as the main model of such interaction. In some combinations modulation of dynamics of AMP-bacterial membrane interaction in presence of the antibiotic was also shown. Cytotoxic effects of the same combinations toward normal eukaryotic cells were rarely synergistic. The obtained data approve that combined application of antimicrobial peptides with antibiotics or other antimicrobials is a promising strategy for further development of new approach for combating antibiotic-resistant bacteria by usage of AMP-based therapeutics. Revealing the conventional antibiotics that increase the activity of human endogenous AMPs against particular pathogens is also important for cure strategies elaboration

A clinical case of genetically confirmed myotubular myopathy

The aim of the study - presentation of a clinical case of genetically confirmed myotubular myopathy.Цель исследования – представление клинического случая генетически подтвержденной миотубулярной миопатии

РЕГУЛЯЦИЯ МИЕЛОПЕРОКСИДАЗОЙ СA2+-СИГНАЛИЗАЦИИ В НЕЙТРОФИЛАХ

It is shown that myeloperoxidase (MPO) initiates an increase in the concentration of intracellular free calcium ions in neutrophils caused both by the release of calcium ions from intracellular stores, and extracellular Ca2+ entry across the plasma membrane channels. It is found that MPO modified by hypohalous acids retains its ability to induce Ca2+-signaling in neutrophils. It is established that MPO-induced entry of Ca2+ into cytosol of neutrophils is not associated with its catalytic activity, but caused by direct binding of MPO to α-subunit of β2-integrin of neutrophils and tyrosine kinase activation.Показано, что миелопероксидаза (МПО) инициирует увеличение концентрации свободных ионов внутриклеточного кальция в нейтрофилах, обусловленное как выходом ионов кальция из внутриклеточных депо, так и входом внеклеточного Са2+ через каналы плазматической мембраны. Установлено, что модифицированная гипогалоидными кислотами МПО сохраняет свою способность инициировать Са2+-сигнализацию в нейтрофилах. МПО-индуцированный вход Са2+ в цитозоль нейтрофилов не связан с проявлением каталитической активности фермента, а обусловлен непосредственным связыванием МПО с α-субъединицей β2-интегрина нейтрофилов и активацией тирозинкиназ

Assessment of actual nutrition among children with multiple milk teeth caries attending preschool educational institutions

The purpose of the study is to assess the actual nutrition of preschool children with multiple caries of milk teeth.Цель исследования – оценить фактическое питание детей и обеспеченность витамином D у детей дошкольного возраста с множественным кариесом молочных зубов

A clinical case of a combination of Spina bifida, Arnold-Chiari anomaly and multiple congenital malformations in a child

The purpose of the study - presentation of a clinical case of a combination of Spina bifida and Arnold-Chiari type 2 anomaly.Цель исследования. Представление клинического случая сочетания Spina bifida и аномалии Арнольда-Киари 2 типа

Изменение уровня металлотионеинов, цинка и меди в плазме крови пациентов с хроническим лимфоцитарным лейкозом

   Изучена взаимосвязь между содержанием металлотионеинов, ионов меди и цинка в плазме периферической крови при хронических лимфоцитарных лейкозах (ХЛЛ) в зависимости от прогрессирования заболевания. Показано, что у пациентов с ХЛЛ при прогрессирующем заболевании, частичной и полной ремиссии значения отношений цинка к меди в плазме крови достоверно снижались по сравнению с аналогичными показателями, характерными для практически здоровых доноров. Установлено, что в плазме крови у пациентов с ХЛЛ при прогрессировании заболевания уменьшается уровень металлотионеинов по сравнению с другими исследуемыми группами, что говорит об обнаруженной нами сниженной функции цистеинсодержащих белков-металлотионинов. На основании полученных данных можно заключить, что отношение концентрации цинка к меди и уровень металлотионенинов в плазме периферической крови могут быть потенциальными диагностическими и прогностическими маркерами при терапии ХЛЛ.   The relationship between the content of metallothioneins, copper and zinc ions in peripheral blood plasma in chronic lymphocytic leukemia (CLL) depending on the disease progression was studied. It was shown that in patients with CLL in blood plasma with a progressive disease, partial and complete remission, the values of the zinc-to-copper ratios significantly decreased in comparison to similar indicators of practically healthy donors. It was established that in patients with CLL, the level of metallothioneins in blood plasma decreases with the disease progression compared to other studied groups, which indicates a reduced function of cysteine-containing metallothionein proteins. Based on the obtained data, it can be concluded that the zinc-to-copper concentration ratio and the level of metallothionenins in peripheral blood plasma are potential diagnostic and prognostic markers in chronic leukemia.   Изучена взаимосвязь между содержанием металлотионеинов, ионов меди и цинка в плазме периферической крови при хронических лимфоцитарных лейкозах (ХЛЛ) в зависимости от прогрессирования заболевания. Показано, что у пациентов с ХЛЛ при прогрессирующем заболевании, частичной и полной ремиссии значения отношений цинка к меди в плазме крови достоверно снижались по сравнению с аналогичными показателями, характерными для практически здоровых доноров. Установлено, что в плазме крови у пациентов с ХЛЛ при прогрессировании заболевания уменьшается уровень металлотионеинов по сравнению с другими исследуемыми группами, что говорит об обнаруженной нами сниженной функции цистеинсодержащих белков-металлотионинов. На основании полученных данных можно заключить, что отношение концентрации цинка к меди и уровень металлотионенинов в плазме периферической крови могут быть потенциальными диагностическими и прогностическими маркерами при терапии ХЛЛ

Two Novel Lytic Bacteriophages Infecting <i>Enterococcus</i> spp. Are Promising Candidates for Targeted Antibacterial Therapy

The rapid emergence of antibiotic resistance is of major concern globally. Among the most worrying pathogenic bacteria are vancomycin-resistant enterococci. Phage therapy is a highly promising method for controlling enterococcal infections. In this study, we described two virulent tailed bacteriophages possessing lytic activity against Enterococcus faecalis and E. faecium isolates. The SSsP-1 bacteriophage belonged to the Saphexavirus genus of the Siphoviridae family, and the GVEsP-1 bacteriophage belonged to the Schiekvirus genus of Herelleviridae. The genomes of both viruses carried putative components of anti-CRISPR systems and did not contain known genes coding for antibiotic-resistance determinants and virulence factors. The conservative arrangement of protein-coding sequences in Saphexavirus and Schiekvirus genomes taken together with positive results of treating enterococcal peritonitis in an animal infection model imply the potential suitability of GVEsP-1 and SSsP-1 bacteriophages for clinical applications

Caprine Bactenecins as Promising Tools for Developing New Antimicrobial and Antitumor Drugs

Proline-rich antimicrobial peptides (PR-AMPs) having a potent antimicrobial activity predominantly toward Gram-negative bacteria and negligible toxicity toward host cells, are attracting attention as new templates for developing antibiotic drugs. We have previously isolated and characterized several bactenecins that are promising in this respect, from the leukocytes of the domestic goat Capra hircus: ChBac5, miniChBac7.5N-\u3b1, and -\u3b2, as well as ChBac3.4. Unlike the others, ChBac3.4 shows a somewhat unusual pattern of activities for a mammalian PR-AMP: it is more active against bacterial membranes as well as tumor and, to the lesser extent, normal cells. Here we describe a SAR study of ChBac3.4 (RFRLPFRRPPIRIHPPPFYPPFRRFL-NH2) which elucidates its peculiarities and evaluates its potential as a lead for antimicrobial or anticancer drugs based on this peptide. A set of designed structural analogues of ChBac3.4 was explored for antibacterial activity toward drug-resistant clinical isolates and antitumor properties. The N-terminal region was found to be important for the antimicrobial action, but not responsible for the toxicity toward mammalian cells. A shortened variant with the best selectivity index toward bacteria demonstrated a pronounced synergy in combination with antibiotics against Gram-negative strains, albeit with a somewhat reduced ability to inhibit biofilm formation compared to native peptide. C-terminal amidation was examined for some analogues, which did not affect antimicrobial activity, but somewhat altered the cytotoxicity toward host cells. Interestingly, non-amidated peptides showed a slight delay in their impact on bacterial membrane integrity. Peptides with enhanced hydrophobicity showed increased toxicity, but in most cases their selectivity toward tumor cells also improved. While most analogues lacked hemolytic properties, a ChBac3.4 variant with two additional tryptophan residues demonstrated an appreciable activity toward human erythrocytes. The variant demonstrating the best tumor/nontumor cell selectivity was found to more actively initiate apoptosis in target cells, though its action was slower than that of the native ChBac3.4. Its antitumor effectiveness was successfully verified in vivo in a murine Ehrlich ascites carcinoma model. The obtained results demonstrate the potential of structural modification to manage caprine bactenecins\u2019 selectivity and activity spectrum and confirm that they are promising prototypes for antimicrobial and anticancer drugs design