Patologicheskaya Fiziologiya i Eksperimental'naya Terapiya (Pathological physiology and experimental therapy)

The pathogenic role of PTPN2 gene polymorphisms in diabetes mellitus type 1

2025-09-14T10:35:23+00:00

Background and aims: Type 1 diabetes mellitus (T1DM) is a multifactorial disease characterized by widespread, severe consequences and leads to early disability and high mortality. This type of diabetes is also characterized by b-cells of Langerhans islets destroying in the pancreas, what leads to a complete dependence of patients on the administration of exogenous insulin. T1DM is an inherited autoimmune disease. An important factor in the pathogenesis of T1DM is a genetic predisposition characterized by the presence of functional single nucleotide polymorphisms (SNPs) in the several genes. It was supposed that the development of the inflammatory reaction may be caused by range of factors encoding by genes of NT1 family. These factors are the tyrosine phosphatases of T-lymphocytes. T1DM development can be explained by the presence of functional polymorphic markers of PTPN2 gene. To study the association with diabetes mellitus type 1 we performed analysis of the distribution of frequencies of alleles and genotypes of polymorphic markers of PTPN2 gene, encoding the tyrosine phosphatase of T-lymphocytes type 2. The study included groups of T1DM patients and unrelated controls of Russian origin.

Methods. Genotyping was performed using methods of RFLP and real-time amplification using set of samples from 366 T1DM Russian origin patients with different manifestation time from 14±5 years overall median and 526 healthy peoples in control group. When comparing the frequencies of genotypes, the Pearson criterion was used. A comprehensive assessment of the relationships between the studied genotypes and the risk of disease was carried out using logistic regression, determining the odds ratio (OR) and 95% confidence interval (CI95%), with a value of p≤0.05.

Results. No statistically significant association of polymorphic markers rs2542151, rs3737361 and rs2542156 of the PTPN2 gene with T1DM was found, while a comparative analysis of the frequency distribution of alleles and genotypes indicates an association of polymorphic marker rs2847281 of the PTPN2 gene with this disease in the Russian population (p=0.0088).

Conclusion. Our data on the association of polymorphic marker rs2847281 of the PTPN2 gene with the risk of developing T1DM complement information on the mechanisms of its occurrence and pathogenesis, which may help to understand the basics of the pathophysiology of T1DM and identify groups of people at high risk of developing T1DM.

Sexual dimorphism of age-related changes in the expression of α, β, and δ subunits of ATP synthase in the aorta and heart of rats: their potential impact on contractile function

2025-09-14T10:35:31+00:00

Aging is a critical risk factor for the development of cardiovascular and cerebrovascular diseases, leading to a decline in quality of life and high mortality rates worldwide. With the aging population, this situation is expected to worsen over time. Age-associated mitochondrial dysfunction is directly linked to the development of cellular senescence phenotypes. This study aimed to evaluate sex-specific early age-related changes in the expression of genes encoding the α, β, and δ subunits of the catalytic F1 domain of ATP synthase in the aorta and heart of rats and their potential impact on vascular contractile function.

Methods. Experiments were conducted on male and female Wistar rats aged 4 and 18 months. The force of contraction of the thoracic aorta was measured in an isometric mode, and gene expression was assessed using PCR analysis. Inhibitory analysis was performed using oligomycin A (an ATP synthase inhibitor) and glibenclamide (a K_ATP channel blocker).

Results. It was found that in the hearts of aged males, there was an increase in the expression of the Atp5f1a and Atp5f1d genes, corresponding to the α and δ subunits of the catalytic F1 domain. In the aging hearts of females, the most significant age-related changes in the expression of the Atp5f1a, Atp5f1b, and Atp5f1d genes encoding the F1 domain subunits were observed in the left atrium, which significantly differed from similar parameters in the left atrium of males (decreased instead of increased expression). A decrease in the expression of the Atp5f1b gene encoding the catalytic β subunit of ATP synthase was also detected in the left ventricle of female rats. In the aortas of aged rats of both sexes, a reduction in the expression of genes encoding the α and β subunits of the catalytic head of F1 and the δ subunit of the central stalk of ATP synthase was observed. It was shown that inhibition of ATP synthase activity using the inhibitor oligomycin A led to a weakening of the contraction force of isolated aortic rings in response to serotonin (5HT) in both young and old rats. This effect was not mediated by K_ATP channel activation, as the blocker glibenclamide did not influence the 5HT-induced vascular response following oligomycin A exposure.

Conclusion. The obtained results indicate early age-related changes in the expression of genes encoding the subunits of the catalytic F1 domain of ATP synthase in conduit vessels and the heart. The identified sex differences in gene expression suggest that the most significant early impairments in ATP synthesis occur in the hearts of female rats, indicating a potential for early ischemic disturbances. It is hypothesized that the high level of expression of the α subunit of the catalytic F1 domain in the aging hearts of males may serve as a compensatory mechanism to meet increased ATP demands. A substantial decrease in the expression of the α and β subunits of the F1 domain in the aortas of aged rats may negatively affect oxidative phosphorylation processes and, consequently, the regulation of vascular tone.

Early life stress causes sex-dependent disorders of cardiovascular regulation in adult rats

2025-09-14T10:36:00+00:00

Background. Early life stress (ELS) is caused by adverse and traumatic events in childhood and is associated with an increased risk of developing mental and physical disorders later in life.

The aim of the study was to investigate the effect of maternal separation and isolation from littermates (MSI) in early ontogenesis on the heart rate autonomic regulation in young adult rats of both sexes under physical (footshock, FS) and psychosocial emotional stress (EmS) (observation of a rat receiving FS, "witness stress").

Methods. Electrocardiograms were recorded noninvasively in non-anesthetized rats (subjected to MSI, 32 males and 28 females, or raised with mother, 23 males and 24 females) using a special cuff with attached electrodes. The heart rate (HR) and time-domain and spectral parameters of the heart rate variability (HRV) were quantified for each 5-min recording.

Results. In the control group, females showed increased basal HRV and HF-range power compared to males. In females (but not in males), after repeated (for 5 days) FS, an increase in HR and a decrease in HRV were observed; EmS caused a decrease in HR. Rats of both sexes after MSI developed a hyperactive phenotype, aggression, and decreased social interaction. Behavioral disorders were accompanied by an increase in basal HR and a decrease in HRV. In the MSI group, in response to repeated FS, HR increased only in females, while EmS caused an increase in HR in rats of both sexes. Moreover, after EmS, HRV increased in females but decreased in males.

Conclusion. ELS caused sex-dependent dysfunctions of the autonomic nervous system in adult rats. Autonomic dysregulation may be one of the mechanisms for stress vulnerability and stress-induced pathologies in adulthood.

The neuroprotective effect of argon-oxygen mixture inhalation 24 hours after ischemic stroke

2025-09-14T10:35:08+00:00

Introduction. Animal studies have shown that adding argon to the breathing mixture increases the survival of animals in models of cerebral hypoxia and ischemia. The important factors affecting the cell recovery after ischemic injury are the exposure time and dosage of argon. Studying the neuroprotective effect of argon 24 hours after the onset of stroke in an animal model will provide data on the feasibility of such delayed therapy. Aim. The study assessed the effect of three 2-hour inhalations of an argon-oxygen mixture (Ar 70%/O2 30%) 24 hours after photochemically induced stroke on the severity of neurological deficit and the volume of brain injury.

Methods. The experiments were performed on male Wistar rats weighing 250‒300 g (n=14). The animals were randomly divided into 3 groups based on the extent of the intervention: control group with ischemia + inhalation of N₂ 70%/O₂ 30% or Ischemia group, n=5; experimental group with ischemia + inhalation of Ar 70%/O₂ 30% (Ischemia+iAr group), n=6, and group of sham-operated animals (SO group), n=3. Neurological status was followed up for 14 days (limb support test). Magnetic resonance imaging (MRI) and immunohistochemistry were performed at 14 days after ischemia.

Results. No statistically significant differences were found between the experimental groups. The mean volume of injury in the Ischemia+iAr group and Ischemia group was 19.5 (16.5; 22.7) mm³ and 22.0 (18.0; 23.7) mm³, respectively (p=0.12). The area of vWF-positive staining in the Ischemia+iAr group was somewhat greater than in the Ischemia group (0.18 [0.15; 0.20] vs. 0.16 [0.14; 0.18], p=0.054); however, the difference was not significant. The number of Cas-3-positive cells was decreased in the Ischemia+iAr group (10384 [9586; 12685]) compared to the Ischemia group (13856 [11548; 18295], p=0.068).

Conclusion. Three-time 2-hour inhalation of the argon-oxygen mixture (Ar 70%/O2 30%) 24 hours after photochemically induced stroke does not reduce the severity of neurological deficit or reduce the volume of injury.

Experimental application of a modified collagen conduit for reconstruction of a sciatic nerve defect in rats

2025-09-14T10:35:01+00:00

Background. Numerous methods and technologies have been used in the development and modification of constructions for the repair of nerve defects. One of these techniques is obtaining biopolymer-based conductive conduits. To increase the efficiency of peripheral nerve repair, various fillers are used, such as extracellular matrix (ECM)-based hydrogels. Aim: To evaluate the reparative effect of an ECM-based hydrogel as a filler for a collagen nerve conduit in an in vivo model of peripheral nerve injury.

Methods. The ECM-based hydrogel was obtained by alkaline hydrolysis of porcine dermis. Sciatic nerve defects were modeled in three groups of Wistar rats: group 1 (n=5), control, autografted defect; group 2 (n=5), defect reconstructed with a NeuraGen^® collagen conduit (Integra, USA) with ECM-based hydrogel; group 3 (n=5), defect reconstructed with a NeuraGen^® conduit without a filling. The reparative effect was evaluated by immunohistochemical staining to quantify the neurofilaments and motor fibers, and the extent of myelination in the proximal, medial, and distal fragments of the nerve.

Results. The immunohistochemical evaluation of the implants showed elevated values of the expression of myelin basic protein (MBP), choline acetyltransferase (ChAT), and neurofilaments (NF) in the proximal segment of the nerve in all animal groups. In the autograft group, the expression values for the analyzed proteins were significantly greater than in the other groups. However, in group 2, the expression of the immunohistochemical markers was greater than in group 3 along the entire length of the reconstructed nerve, indicating a beneficial effect of the ECM-based hydrogel modification in the nerve conduit.

Conclusion. The modification of the NeuraGen^® collagen conduit with the ECM-based hydrogel enhanced the efficacy of the nerve tissue regeneration following the repair of peripheral nerve defects. The obtained hydrogel likely exerts a stimulatory effect on the growth of nerve fibers and enhances the migration and proliferation of Schwann cells, which underscores the need for further development and refinement of existing nerve conduits.

The indicators of endogenous intoxication in the dynamic of pregnancy in women with HIV infection

2025-09-14T10:34:46+00:00

Background. Endotoxicosis is a complex pathophysiological process that has a major impact on the mother-placenta-fetus system during pregnancy, and in some cases, is associated with tissue destruction. The human immunodeficiency virus is an aggravating factor that can increase the risk of endotoxicosis during pregnancy. The aim was to assess the level of endogenous intoxication in HIV-positive women during pregnancy by the content of medium-weight molecules in venous blood.

Methods. The severity of endogenous intoxication was assessed by the content of medium-weight molecules (MSM) in pregnant women with a HIV-positive status. The study included 33 women aged 23 to 35 years. The indicators were evaluated at 4 points: 6-12, 18-22, 28-32, and 38-40 weeks of pregnancy. Blood plasma was used as the study material. The MSM content was measured by spectrophotometry at λ =238, 254, 260, and 280 nm, followed by the calculation of the distribution coefficients (238/260, 238/280, 280/254). The MSM fraction content was expressed in optical density units.

Results. A significant increase in the MSM level was found at λ=260 nm and λ=280 nm at 38-40 weeks compared to 28-32 weeks (p<0.05). The content of MSM280 was higher before childbirth compared to 6-12 week pregnancy (p<0.05). The peptide-nucleotide distribution coefficient (238/260 nm), as well as the aromaticity coefficient (238/280 nm) were lower at 38-40 weeks of pregnancy compared with the first trimester of gestation (p<0.05).

Conclusion. The MSM detected at λ=260 nm and 280 nm, as well as the coefficients of aromaticity and the peptide-nucleotide coefficient proved to be sensitive markers for monitoring the level of endogenous intoxication in HIV-positive pregnant women. Measuring MSM in HIV-positive pregnant women can be used not only as an indicator of endogenous intoxication, but also as an indirect indicator of excessive generation of oxygen metabolites and peroxide damage to biological substrates.

The role of calcium and phosphorus metabolism in the pathogenesis of newborn cephalohematoma

2025-09-14T10:35:38+00:00

Background. A special type of complication in cephalohematomas is pathological cranial vault remodeling. It is possible to trace the dynamics of bone tissue changes in cephalohematomas based on measuring the indexes of calcium and phosphorus metabolism in the blood of newborns. Aim. To measure the serum concentration of calcium and phosphorus metabolism indexes in neonatal patients with cephalohematomas and to evaluate the dynamics of local bone changes in the projection of cephalohematoma.

Methods. The study included 90 infants observed during the newborn period; 30 of them had medium and large cephalohematomas (punctured); 30 had small cephalohematomas (not punctured); and 30 healthy infants. The concentration of calcium and phosphorus metabolism indexes was measured photometrically with an Indiko analyzer using ThermoFisher Scientific Inc. kits. Ultrasonography and local craniometry were used to record local bone changes.

Results. On days 10 and 28, the total calcium concentration in patients with medium and large cephalohematomas was 28.6‒31.5% lower than in the control group. The decrease in blood calcium in patients with medium- and large-volume cephalohematomas was not associated with a compensatory increase in parathyroid hormone and was evident in a more pronounced local osteolytic process in the projection of hemorrhage.

Conclusion. Resolution of cephalohematomas is accompanied by local bone changes that depend on calcium metabolism. Changes in the parameters of calcium and phosphorus metabolism may reflect the dynamics of local pathological cranial bone remodeling during subperiosteal hemorrhage.

Morphometric characteristics of hepatocyte cells of rat embryos during the exposure to titanium dioxide nanoparticles in the prenatal period of development

2025-09-14T10:35:16+00:00

Introduction. The food supplement E171 (titanium dioxide, TiO2) is widely used in the food and paint industries as a white pigment due to its chemical stability. Previously considered safe, TiO2 in the form of nanoparticles (NPs) raises concerns due to its ability to penetrate biological barriers and accumulate in embryonic tissues, potentially leading to embryotoxic effects. Aim. To investigate the morphometric characteristics of liver cells in Wistar rat embryos when exposed to TiO2 NPs during the antenatal period.

Methods. The TiO2 suspension was prepared using ultrasonic treatment in distilled water. The study included 12 female Wistar rats (weight 210-250 g) divided into the experimental (n=7) and control (n=5) groups. The experimental group was orally administered a suspension of rutile TiO2 NPs (particle size 30-50 nm) for 14 days prior to gestation and during pregnancy. The control group received a 0.9% NaCl solution. Euthanasia of the females was performed by intraperitoneal injection of chloral hydrate (400 mg/kg). Embryos (experimental group, 28; control group, 19) were isolated on the 15^th and 20^th days of gestation. The embryonic liver was fixed in 10% formalin, dehydrated, and embedded in paraffin. Sections (5 μm) were stained with hematoxylin and eosin. Morphometric analysis was conducted with a light microscope and the QuPath 0.5.1 software. Cell were counted in 10 fields of view (magnification ×100). Statistical analysis was performed using STATISTICA 13.5 with the Mann-Whitney test (p<0.05).

Results. On the 15^th day, no statistically significant differences in morphometric parameters were observed. On the 20^th day, the experimental group showed an 18% reduction in hepatocyte count, a 20% decrease in their area, and a 372% increase in macrophage count (p<0,05). Hepatocyte apoptosis and macrophage infiltration were noted.

Conclusion. Exposure to TiO2 NPs disrupts the liver development in embryos at later stages of gestation evident as a reduced hepatocyte count, altered morphometric characteristics, and increased macrophage infiltration, which indicated hepatotoxicity and potential risks to the developing organism.

The characteristics of platelet parameters in blood donors

2025-09-14T10:34:54+00:00

Background. Data on the state of the platelet lineage in frequent blood and platelet donors are fragmentary and sometimes contradictory; thus, studies in this direction are continuing. This is especially important due to the increasing use of plateletpheresis. Aim of this study was to evaluate the platelet count values obtained from the automated hematological analysis in various categories of blood and blood product donors.

Methods. This was a single-center cross-sectional study of blood samples from frequent blood and platelet donors. Platelet parameters were assessed depending on the donorship duration and type. A Sysmex 1000XM hematological analyzer was used.

Results. In all blood donors, the platelet count remained within the reference interval regardless of the number of donations. Blood donors with 3–7 years of experience showed a mean 20% increase (p<0.05) in platelet distribution width (anisocytosis) associated with a 26% increase (p<0.05) in the proportion of large platelets (P-LCR). The proportion of large platelets was also increased in platelet donors. In frequent donors, no differences were found between platelet parameters no matter the donation type (blood or platelets).

Conclusion. Our data indicate the absence of platelet disorders in donors of blood and its products. The minor deviations identified in some parameters indicate physiological stimulation of thrombocytopoiesis and are temporary, reactive in the nature.

Prognostic markers for the course of brucellosis infection

2025-09-14T10:35:53+00:00

Introduction. Studies have shown that hemostatic disorders in brucellosis develop due to the systemic nature of the infection and lead to endothelial dysfunction. The state of the hemostatic system in brucellosis infection remains virtually unstudied, which warrants further research. Identification of diagnostic markers can help assess the prognosis of the disease and early detection of the risk for developing vascular complications.

The aim of the study was to determine markers of the anticoagulant hemostatic system and the importance of vascular endothelial factor in assessing the prognosis of brucellosis.

Methods. The study included patients diagnosed with acute brucellosis (n = 78) who were admitted to the Brucellosis Department of Stavropol and the hospital for infectious diseases of the Republic of Dagestan. The study material was blood serum/plasma from patients with acute brucellosis. The control group consisted of 34 individuals who had not had brucellosis and were not vaccinated against this infection. The plasma concentration of antithrombin III was measured by the chromogenic method; the concentration of protein C was determined photometrically; the concentration of fibrinogen was measured using an automatic analyzer; soluble fibrin-monomer complexes (SFMC) were assessed by the orthophenanthroline test; and the concentration of vascular endothelial growth factor (VEGF) was determined by the enzyme-linked immunosorbent assay (ELISA).

Results. In the acute phase of the disease, patients with brucellosis had decreases in the plasma concentrations of primary anticoagulants (antithrombin III, protein C), an increase in fibrinogen, and, as a consequence, an increase in the concentration of the secondary anticoagulant (SFMC) relative to the control group. The concentration of the endothelial marker, vascular endothelial factor, was increased.

Conclusion. Long-term persistence of brucellosis leads to a rather lengthy, but not pronounced inflammation that results in the development of a protective adaptive reaction aimed at maintaining the hemostatic system. The studied indicators (antithrombin III, protein C, fibrinogen, SFMC, VEGF) are diagnostically significant in assessing the prognosis of the course of brucellosis infection.Introduction.

Lymphocyte RNA improves microcirculation in intensively working skeletal muscles

2025-09-14T10:35:45+00:00

Aim: To demonstrate the significance of lymphoid RNA regulatory mechanisms for maintaining blood flow in the microvasculature of intensively working skeletal muscles.

Methods. Male Wistar rats were divided into 3 groups of 6 animals each: group 1, intact rats; group 2, exercising rats; group 3, exercising rats injected with RNA. The exercise was 6-week swimming, the duration of which was increased every week by 5 minutes (total from 30 to 55 min). RNA was isolated from spleen lymphocytes of 30-day-old pigs and administered to exercising rats at a dose of 30 μg/100 g (4 injections one week apart). The state of the microvasculature was assessed by laser flowmetry. The pattern of microcirculation changes was described with standard and normalized amplitude-frequency indices in different ranges.

Results. Compared with group 1, the blood flow variation coefficient increased by 1.2 times in group 2 and by 1.8 times in group 3. Compared with group 1, the shunt coefficient decreased by 23.1% in group 2 and by 44.4% in group 3. Compared with group 1, the arteriolar tone did not change in group 2 and increased by 1.3 times in group 3. Compared with group 1, the microcirculatory bed resistance coefficient did not change in group 2 and decreased by 23.1% in group 3. The myogenic regulation index was similar in all groups. The neurogenic component of regulation increased by 1.5 times in group 2 and by 2.1 times in group 3 compared with group 1. The endothelium-dependent component of regulation increased by 1.4 times in group 3 compared to group 1. The effects of respiratory rhythm and pulse waves were similar in all groups.

Conclusion. Lymphocyte RNA helps maintain blood flow stability and increase the adaptive capabilities of vascular tone regulation in the microcirculatory bed of intensively working skeletal muscles.

Mechanisms of cardiovascular resistance to injury in post-traumatic stress disorder

2025-09-14T10:34:39+00:00

Post-traumatic stress disorder (PTSD) is a severe psychiatric disorder that develops in people who have experienced traumatic events. PTSD often induces cardiovascular diseases and is their predictor and independent risk factor. Although approximately 50 to 84% of people experience severe, traumatic events during their lifetime, most of them do not develop chronic PTSD. The review summarizes experimental and clinical reports on the mechanisms of cardiovascular resistance to PTSD, which can help developing methods to enhance PTSD resilience in high-risk groups.

Changes in steroidogenesis in psychoneurological diseases as a pathological aspect of the development of clinical phenomena

2025-09-14T10:34:31+00:00

The review focuses on the function of steroid hormones as an important component of the neuroimmunoendocrine regulatory system responsible for adaptation of the body both at the physiological and behavioral levels. The authors address the neurobiological effects of steroid hormones, their contribution as trophic and immunoregulatory factors, and as modulators of neuronal excitability in maintaining normal functioning of the central nervous system, including their role in its adaptation to stress triggers. Neurosteroidogenesis is described as a mechanism for the production of auto- and paracrine regulators in the central nervous system, along with individual neurobiological effects of glucocorticoids and sex steroids. Changes in the production of steroids with neuroactive properties, primarily caused by stress-induced hypothalamic-pituitary-adrenal axis dysregulation, are considered as a factor of the development and progression of central pathology. The review discusses the involvement of steroid changes in adult and pediatric neuropsychiatric diseases, including affective, anxiety, and behavioral disorders, neuroinflammatory and neurodegenerative diseases, neurodevelopmental delays and disorders. A possibility is shown of modulating the endocrine axes, specifically the hypothalamic-pituitary-adrenal axis, with hormonal agents in the treatment of patients.

The role of matrix metalloproteinases in the development of atherosclerosis

2025-09-14T10:34:24+00:00

The physiological role of matrix metalloproteinases (MMPs) is the regulation of the extracellular matrix. During the development of a number of pathological processes, the secretion of MMPs by mesenchymal cells and immunocompetent cells increases significantly, which consistently causes matrix remodeling. The importance of MMPs is extremely latitudinous and extends to many areas of health care. MMPs are known to be involved in the process of tumor metastasis, therefore, studying their activity can help in the development of new methods for diagnosing and treating malignant neoplasms. Moreover, MMPs are associated with cartilage degradation in osteoarthritis. Their in-hibitors can be used to slow down the progression of the disease. In the aspect of cardiovascular pathology, MMPs attract attention due to their significant participation in vascular wall remodeling. The aim of the study was to clarify the role of MMPs in the pathogenesis of coronary atherosclero-sis based on the analysis of scientific literature with elements of a systematic review. Articles were searched in three online databases (PubMed, Google Scholar, and Cyberleninka). The inclusion criteria were full-text original articles in English and Russian, reports on MMPs in atherosclerosis and/or ischemic heart disease, and clinical trials. The exclusion criteria were conference abstracts, editorials, newsletters, books, and book chapters. Multiple cardiovascular pathologies, including atherosclerosis, largely depend on extracellular matrix turnover. An imbalance between MMPs and their tissue inhibitors leads to proteolytic activity dysregulation and adverse extracellular matrix remodeling, which is associated with the progression and instability of atherosclerotic plaques in the coronary arteries. Increased activity of MMPs, as well as their imbalance with tissue inhibitors of MMPs, results in remodeling of the extracellular matrix, which makes the atherosclerotic plaque more susceptible to rupture. Since excessive tissue remodeling and increased MMP activity are parts of the pathogenesis of atherosclerotic lesions, MMPs remain an attractive target for the development of anti-atherosclerotic drugs.