Fluorescently labeled and conjugated (strept)avidins are widely used for imaging biotinylated molecules in immunological assays and histochemistry. We showed that besides biotin, these proteins bind glycans, including fragments of mammalian glycoproteins and glycolipids, in particular, ABO blood group antigens, oligolactosamines, and 6-O-sulfated oligosaccharides. This interaction is inhibited in a dose-dependent manner by micromolar concentrations of polymeric, but not monomeric, glycan conjugates (i.e., requires polyvalence). Taking into account the cluster organization of cell glycans (glycoproteins and glycolipids), the ability of (strept)avidins to bind glycans might be a source of errors in the analysis of carbohydrate-containing samples, which can be prevented by avoiding a large excess of (strept)avidin in analytical systems.

Потенциальные возможности культуры реализуются на физиологическом уровне, включающий процесс фотосинтеза. В исследованиях были изучены особенности формирования и работы фотосинтетического аппарата люпина узколистного в условиях степной зоны Северного Казахстана в зависимости от агроприемов: сроки посева, нормы высева и применение регуляторов роста. Опыты проводились на базе Северо-Казахстанской сельскохозяйственной опытной станции в 2023 году. Объектом служил среднеспелый сорт узколистного люпина Орловский кормовой. В статье представлены результаты изучения показателей фотосинтетической деятельности: ассимиляционная поверхность, накопление сухого вещества, фотосинтетического потенциала, чистая продуктивности фотосинтеза. Определение данных показателей позволило объективно оценить их зависимость от элементов агротехники, а также влияние фотосинтетической активности на продуктивность люпина. Исследования показали, что обработка регуляторами роста Мегамикс Семена до посева (1,5 л/т) и по вегетации Мегамикс Бор (1 л/т) обеспечивают максимальные показатели в фазу плодообразования - по ассимиляционной поверхности (48,5 см2), фотосинтетического потенциала (55,25 тыс.м2 х сутки/га), в фазу созревания - по сухой биомассе (3,91 г/растение), чистой продуктивности фотосинтеза (96,1 г/м2 в сутки). Посев 5 мая с нормой 1,0 млн.в.с. был оптимальным в условиях засушливого климата для формирования продуктивности – 9,7 ц/га. В данных опытах отмечается положительная корреляция урожайности с площадью листовой поверхности (r= 0,87-0,91) и накоплением сухого вещества (r= 0,79-0,96.)

Renal reperfusion injury develops rapidly after ischemia relief. It is with the onset of reperfusion that a cascade of pathological processes is launched, which means that measures to protect the kidney have to be taken as early as in this period. The aim of the paper was to study the effect of exogenous peroxiredoxin 6 (Prx6) on the morphofunctional state of nephrons in the initial reperfusion period following ischemia. Materials and methods. The right kidney of rats was subjected to 45-minute ischemia with prior left-sided nephrectomy and examined after 2, 5 and 24 hours of reperfusion. Exogenous Prx6 was administered intravenously 15 minutes before ischemia. Results. The research showed that nephrectomy has no effect on the morphology of a single kidney, but leads to an increase in urea and creatinine in the blood within 24 hours. We noted signs of morphological and functional damage to nephrons after 2 hours of reperfusion, which tend to increase in the course of 24 hours. In addition, we observed a rise in blood creatinine and urea concentrations, an increase in the areas of renal corpuscles, glomeruli, and Bowman’s capsule, as well as dystrophic changes in nephrocytes and an increase in the immunosignal area of the kidney injury molecule-1 (KIM-1). When exogenous Prx6 was used, we observed normalization of the size of nephron components, a decrease in KIM-1 immunosignal and an improvement in the kidney’s excretory function both in the early reperfusion period and after 24 hours. Thus, exogenous Prx6 reduces damage to nephrons during the early reperfusion period, which improves their compensatory and adaptive properties in ischemia-reperfusion injury.

Реперфузионное поражение нефронов почки стремительно развивается после купирования ишемии. Запуск каскада патологических процессов происходит именно с началом реперфузии, что обусловливает необходимость проведения мероприятий по протекции органа уже в этот период. Цель работы – исследование влияния экзогенного пероксиредоксина 6 на морфофункциональное состояние нефронов почки в начальный реперфузионный период после ишемии. Материалы и методы. Правую почку крыс подвергали 45-минутной ишемии с предварительной левосторонней нефрэктомией и исследовали через 2, 5 и 24 ч реперфузии. Экзогенный пероксиредоксин 6 вводили внутривенно за 15 мин до ишемии. Результаты. Показано, что нефрэктомия не оказывает влияния на морфологию единственной почки, однако приводит к росту концентраций мочевины и креатинина в крови в течение первых суток. Признаки морфофункциональных повреждений нефронов отмечены через 2 ч реперфузии и имеют тенденцию к нарастанию в течение 24 ч. Установлены рост концентраций креатинина и мочевины в крови, площадей почечных телец, сосудистых клубочков и Боуменова пространства, развитие дистрофических изменений нефроцитов и увеличение площади иммуносигнала молекулы поражения почек KIМ-1. При использовании экзогенного пероксиредоксина 6 выявлены нормализация размеров компонентов нефронов, снижение иммуносигнала KIМ-1 и улучшение экскреторной функции почки как в ранний реперфузионный период, так и через 24 ч реперфузии. Таким образом, экзогенный пероксиредоксин 6 снижает поражение нефронов почки в ранний реперфузионный период, что способствует улучшению их компенсаторно-приспособительных свойств в условиях ишемически-реперфузионного поражения.

Acute kidney injury provokes liver dysfunction, which is an aggravating factor for effective treatment. In this study, ischemic-reperfusion kidney injury was used as a model. Since the main damaging factor in this case is the hyperproduction of reactive oxygen species, to prevent liver injury under kidney injury, an exogenous antioxidant enzyme peroxyredoxin 6 was used, which is able to neutralize the hyperproduction of a wide range of reactive oxygen species. Kidney injury was initiated by 45 min ischemia with simultaneous left-sided nephrectomy. The liver was not manipulated. Peroxiredoxin 6 was administered intravenously 15 min before ischemia. Liver condition was assessed 2, 5 and 24 h after kidney reperfusion by histological and biochemical methods. The maximum signs of liver injury were detected after 5 h of kidney reperfusion. The use of peroxiredoxin 6 led to a decrease in the severity of vascular reaction and leukocyte infiltration in the liver, a decrease in the degree of dystrophy and apoptosis of hepatocytes, the absence of an increase in the concentration of TBA-reactive products and stabilization of the level of cytokines IL-6, IL-10 in liver tissue, as well as normalization of the activity of intracellular transferases in the blood with the onset of reperfusion. The protective effect of peroxiredoxin 6 was primarily associated with its antioxidant properties, which make it possible to neutralize the hyperproduction of reactive oxygen species at the initial period of kidney reperfusion; however, the contribution of the signal-regulatory function of the protein to its protective effect should not be excluded.

Ischemia-reperfusion (I-R) injury causes a reduction in the viability of donor organs during long-term conservation. In the present study, an antioxidant enzyme peroxiredoxin 6 was used to increase the resistance of donor kidneys to I-R injury. To find the efficiency of using peroxiredoxin 6, we evaluated the morphological and functional parameters of the isolated kidney, the expression level of kidney injury molecule-1 (KIM-1) as a marker of kidney damage, and the level of malonic dialdehyde in the tissue. Cold storage of the kidney in DMEM solution, which was not customized, was shown to result in organ death during perfusion. In contrast, the use of Custodiol solution allowed the kidney to survive an episode of prolonged ischemia and perfusion. The combination of peroxiredoxin 6 with Custodiol solution led to a better outcome. In addition to a decreased damage to nephron structures, a 2.3-fold reduction of the malonic dialdehyde level was registered, thus indicating neutralization of hyperproduction of reactive oxygen species. The urinary flow rate, glomerular filtration rate, and the amount of urea in the urine increased fourfold, thereby indicating that tubular structures were preserved, as confirmed by a 1.5-fold decrease in the level of KIM-1. Thus, the use of peroxiredoxin 6, an exogenous antioxidant protein, during perfusion increases the resistance of the donor kidney to ischemia-reperfusion injury after prolonged cold storage in Custodiol solution.

Objective: to investigate the role of peroxiredoxin 6 (PRX6) in preserving the morphofunctional state of ischemic isolated kidney during perfusion.Materials and methods. The model of an isolated perfused rat kidney was used. Ischemia time was 5 and 20 minutes, perfusion was 50 minutes. To evaluate the effectiveness of PRX6 at different ischemia times, we used the conventional criteria of kidney function and histological methods.Results. During short warm ischemia times, exogenous PRX6 improves the morphofunctional state of an isolated kidney during perfusion. During this period, the main criteria for functioning of the isolated ischemic kidney reach acceptable values, renal parenchyma is without severe damage. By the end of perfusion, there was an increase in urine flow rate, glomerular filtration rate, fractional glucose reabsorption, urine urea concentration and proportion of primary urine from 1.5 to 2 times compared with the control lesion. At 20-minute ischemia, the isolated kidney can be recognized as non-viable according to the functioning criteria; the positive effect of PRX6 is leveled.Conclusion. The use of recombinant peroxiredoxin 6 for preserving the morphofunctional state of isolated kidneys can be an effective approach in preventing ischemia–reperfusion injury.

Protective effects of peroxiredoxin 6 (PRDX6) in RIN-m5F β-cells and of thymulin in mice with alloxan-induced diabetes were recently reported. The present work was aimed at studying the efficiency of thymulin and PRDX6 in a type 1 diabetes mellitus model induced by streptozotocin in mice. Effects of prolonged treatment with PRDX6 or thymic peptide thymulin on diabetes development were evaluated. We assessed the effects of the drugs on the physiological status of diabetic mice by measuring blood glucose, body weight, and cell counts in several organs, as well as effects of thymulin and PRDX6 on the immune status of diabetic mice measuring concentrations of pro-inflammatory cytokines in blood plasma (TNF-α, interleukin-5 and 17, and interferon-γ), activity of NF-κB and JNK pathways, and Hsp90α expression in immune cells. Both thymulin and PRDX6 reduced the physiological impairments in diabetic mice at various levels. Thymulin and PRDX6 provide beneficial effects in the model of diabetes via very different mechanisms. Taken together, the results of our study indicated that the thymic peptide and the antioxidant enzyme have anti-inflammatory functions. As increasing evidences show diabetes mellitus as a distinct comorbidity leading to acute respiratory distress syndrome and increased mortality in patients with COVID-19 having cytokine storm, thymulin, and PRDX6 might serve as a supporting anti-inflammatory treatment in the therapy of COVID 19 in diabetic patients.

Oxidative stress caused by ischemia–reperfusion kidney injury may play a key role in liver dysfunction. To reduce liver and kidney damage in ischemia–reperfusion kidney injury, an exogenous enzyme antioxidant peroxiredoxin 6 was used, which is able to restore a wide range of hydroperoxides and is a participant in intracellular and intercellular signal transmission. Rats were subjected to ischemic kidney injury for 45 min with simultaneous left-sided nephroectomy and examined after 24 and 48 h of reperfusion. Peroxiredoxin 6 was administered intravenously 15 min before ischemia. Injury to the renal and hepatic tissues was determined by histological methods; in addition, the concentrations of creatinine, urea, alanine aminotransferase and aspartate aminotransferase in the blood were measured to assess the functionality of the organs. Reperfusion led to an increase in the concentrations of creatinine, urea, alanine aminotransferase and aspartate aminotransferase in blood plasma; there was also violation of the architecture of renal nephrons and the development of a pronounced vascular reaction in the liver with foci of degenerative changes. The use of exogenous peroxiredoxin 6 led to a decrease in the damage to the renal and hepatic tissues and normalization of the level of renal and hepatic metabolites. Thus, peroxiredoxin 6 showed both a nephroprotective effect in renal ischemia–reperfusion and reduced morphofunctional damage to distant organs, in particular, the liver.

Many viruses, beside binding to their main cell target, interact with other molecules that promote virus adhesion to the cell; often, these additional targets are glycans. The main receptor for SARS-CoV-2 is a peptide motif in the ACE2 protein. We studied interaction of the recombinant SARS-CoV-2 spike (S) protein with an array of glycoconjugates, including various sialylated, sulfated, and other glycans, and found that the S protein binds some (but not all) glycans of the lactosamine family. We suggest that parallel influenza infection will promote SARS-CoV-2 adhesion to the respiratory epithelial cells due to the unmasking of lactosamine chains by the influenza virus neuraminidase.

Окислительный стресс, вызванный ишемически-реперфузионным поражением почек, может играть ключевую роль в дисфункции печени. Для снижения поражения печени и почек при ренальном ишемически-реперфузионном поражении в работе использовали экзогенный фермент-антиоксидант пероксиредоксин 6, который способен восстанавливать широкий спектр гидропероксидов и является участником во внутриклеточной и межклеточной передаче сигналов. Крыс подвергали ишемическому поражению почек в течение 45 мин с одновременной левосторонней нефроэктомией и обследовали через 24 и 48 ч реперфузии. Пероксиредоксин 6 вводили внутривенно за 15 мин до ишемии. Повреждение почечной и печеночной тканей определяли гистологическими методами, для оценки функциональности органов измеряли концентрации креатинина, мочевины, аланинаминотрансферазы и аспартатаминотрасферазы в крови. Реперфузия привела к увеличению концентраций креатинина, мочевины, аланинаминотрансферазы и аспартатаминотрасферазы в плазме; нарушению архитектуры почечных нефронов и развитию выраженной сосудистой реакции в печени с очагами дегенеративных изменений. Использование экзогенного пероксиредоксина 6 привело к снижению поражения ренальной и печеночной тканей и нормализации уровня почечных и печеночных метаболитов. Таким образом, пероксиредоксин 6 проявляет как нефро-протекторный эффект при ренальной ишемии-реперфузии, так и уменьшает морфофункциональное повреждение отдаленных органов, в частности печени.

Abstract—The aim of this study was to investigate the protective effect of exogenous peroxiredoxins with ischemia–reperfusion of an isolated kidney. The study was carried out using a model of isolated rat kidney perfusion ex vivo. A recombinant peroxiredoxin 6 was injected directly in the perfusion buffer. The high-molecular-weight dye Blue Dextran 2000 and urea were added to the perfusion buffer to determine the functionality of an isolated kidney. It was demonstrated that exogenous peroxiredoxin 6 in the cortical layer of an isolated kidney was localized in the vessels of renal glomeruli; in the medulla it was found in microvessels surrounding the thin tubules. The use of peroxiredoxin 6 decreases the degree of damage of nephron structures by two times compared with the damage in the control, which provides the preservation of ultrafiltration processes. A decrease in glomerular damage leads to a decrease in the content of Blue Dextran by two times compared with the damage in the control at the end of the perfusion period. A decrease in the damage of tubular structures indicates the active urea transport during perfusion. Thus, the inclusion of peroxiredoxin 6 in the perfusion buffer mediated a decrease in the damage of nephron structures and maintenance of the multifunctional state of renal glomeruli and tubules.

Abstract—The Miles assay using Evans Blue dye is a conventional method to assess vascular permeability. The penetration Evans dye into intestinal tissue was studied in the early reperfusion phase of ischemia–reperfusion injury to the small intestine. Significant destruction of villus microvessels and an increase in vascular permeability to plasma proteins were observed in the early reperfusion phase, impairing the blood flow at the microvasculature level based on evidence from histology and laser Doppler flowmetry. Evans Blue accumulated to the highest concentration in intestinal tissue after being injected into the bloodstream prior to 60-min ischemia; the lowest level was detected when the dye was injected after 15-min reperfusion. Changes in the dye content in intestinal tissue therefore depended on the number of vessels that remain intact at the time of dye injection at various stages of ischemia–reperfusion. Evans Blue observed in tissue was assumed to reflect the degree of vessel preservation in a study of ischemia–reperfusion injury of the small intestine, rather than reporting the degree of vascular permeability, as commonly believed.

We studied immunogenicity of two recombinant proteins FR.9 and FR.11-3 created on the basis of fragments of the primary structure of N. meningitidis IgA1 protease with different molecular weights containing different sets of T and B epitopes. The proteins actively protect animals infected with live virulent culture of meningococci, serogroups A, B, and C. Analysis of CD4+, CD8+, and CD19+ lymphocyte populations in mouse blood showed predominant contribution of different cell populations to the formation of immune response to different proteins. Injection of FR.11-3 protein to animals did no affect the immunoregulatory index, hence, this protein can be used for creation of immunologically safe vaccine preparation.

Four recombinant proteins, MA 28 –P 1004 LEH 6 , ME 135 –H 328 LEH 6 , MW 329 –H 622 LEH 6 and MH 835 –P 1004 LEH 6 , were prepared based on the genomic sequence of IgA1 protease from Neisseria meningitidis serogroup B strain H44/76. The immunogenic and protective properties of these proteins were studied in a mouse model. The predicted T- and B-epitopes located in the N-terminal part of amino acid sequence of this enzyme are very important for the formation of effective protection against meningococci of the three main epidemic serogroups A, B, and C. The small-sized recombinant protein having the sequence ME 135 –H 328 LEH 6 (molecular weight 23367 Da) appears to be as protective against meningococci of the tested serogroups as the high molecular MA 28 –P 1004 LEH 6 (molecular weight 109019 Da), the latter being a large-sized analog of full-length IgA1 protease. These proteins can be promising candidates for a polyvalent meningococcal vaccine.