[Correction of serum prooncogenic cytokines and metastases by 5-hydroxypyrimidine derivatives and doxorubicin after removal of a primary tumor node in mice with the Lewis lung epidermoid carcinoma]

The effect of a single injection of doxorubicin, 8-day administration of two 5-hydroxypyrimidine derivatives, SNK-411 (2-Isobutyl-4,6-dimethyl-5-hydroxypyrimidine) and SNK-578 (hydrochloride of 2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine), on metastases, lifespan and serum cytokines has been investigated in С57ВL/6 mice after removal of a primary tumor node of Lewis lung carcinoma (LLC). LLC cells (1×106) were injected in the footpad of right hind feet of mice in control and experimental groups; after 14 days of tumor development the hind feet with the tumor were amputated at the ankle level. One hour before the amputation mice received a single injection of doxorubicin (4 mg/kg) and 8-day therapy with the 5-hydroxypyrimidine derivatives started. SNK-578 monotherapy was performed at a dose of 10 mg/kg administered intraperitoneally (i.p.). SNK-411 was administered per os at a dose of 25 mg/kg. In the case of combined therapy mice also received a single injection of doxorubicin (4 mg/kg; i.p.). The metastasis inhibition index in mice-treated with SNK-411 and SNK-578 were 53.3% as compared with control mice (with removed tumor). The mice-treated with SNK-411, doxorubicin, and the combination SNK-578 + doxorubicin had lifespan increased by 60.2%, 53.9%, and 42.9%, respectively. A single injection of doxorubicin, the course administration of the 5-hydroxypyrimidine derivative alone and in combination with single injection of doxorubicin completely decreased serum levels of the prooncogenic Th2-cytokines IL-4, and IL-6 and significantly decreased the level of the Th2-cytokine IL-5. Administration of doxorubicin, SNK-411 and SNK-578 did not influence serum concentration of Th1-cytokine interferon gamma (IFN-γ). These data confirm our previous findings that administration of the compounds studied decreased concentrations of prooncogenic IL-4 and IL-6 in tumor-bearing mice with LLC and had no effect on concentrations of the Th1-cytokine IFN-γ.

[Investigation of the effect of ethylmethylhydroxypyridine succinate on the effectiveness of non-steroidal anti-inflammatory drugs for visceral and somatic pain in mice and rats]

OBJECTIVE

To study the effect of ethylmethylhydroxypyridine succinate (EMHPS) on the analgesic effect of the non-selective cyclooxygenase (COX) inhibitor diclofenac sodium and the selective COX-2 inhibitor etoricoxib in models of acute visceral and somatic pain and to evaluate the possibility of using EMHPS in combination with COX inhibitors to reduce their doses while maintaining analgesic efficiency.

MATERIAL AND METHODS

We studied the effect of EMHPS with a single oral administration on the analgesic effects of non-steroidal anti-inflammatory drugs (NSAIDs): the non-selective COX inhibitor diclofenac sodium and the selective COX-2 inhibitor etoricoxib - on models of acute visceral (vinegar writhing test) and somatic pain (formalin test and mechanical hyperalgesia during inflammation) in an experiment on mice and rats.

RESULTS

In a model of acute visceral pain in mice, EMGPS (25-100 mg/kg) does not have a significant effect on its severity, but enhances the analgesic effect of diclofenac sodium (0.5 mg/kg) and etoricoxib (1 mg/kg). In the formalin test in rats, which simulates pain during surgical incisions (trauma), EMGPS (25 mg/kg) increases the severity of the analgesic effect of COX inhibitors (1 mg/kg), primarily by reducing pain in the acute phase caused by the effect of formalin on afferent neurons. In a model of mechanical hyperalgesia in rats caused by exudative inflammation after injection of a carrageenan solution into the paw, EMHPS enhances the effect of diclofenac to a greater extent than etoricoxib.

CONCLUSION

The data obtained indicate the feasibility of a clinical study of the use of EMGPS in combination with NSAIDs for visceral and somatic pain in order to assess its ability to increase the therapeutic effect of NSAIDs.

The possibility of diagnosing intrauterine infection by the content of nitrite and non-thiolate nitroso compounds in maternal blood plasma

The aim of the study is to develop a method for early diagnosis of intrauterine infection (IUI). A study of markers of inflammation in the venous blood of 60 pregnant women was conducted. The study was followed by a retrospective assessment of the outcomes of pregnancies and childbirth. Of these, 33 patients with a gestation period of more than 37 weeks (full-term pregnancy) and, accordingly, 27 patients from whom the blood sample was taken at a period of less than 37 weeks - patients with the threat of premature birth (PB). PB is the main factor contributing to the development of IUI. 27 patients were diagnosed with premature rupture of the membranes (PROM). Of these, 15 are with the threat of PB. 8 of them had a diagnosed IUI. In all cases of diagnosed PROM, including those with IUI, the concentration of nitrite and nontiolate nitroso compounds (NO2-+RNO) in the mother's blood plasma was 2.3±1.2 µM, while normally it does not exceed 0.1 µM (p<0.001). Regardless of the duration of pregnancy. The use of antibiotics in the case of PROM contributed to the normalization of the concentration (NO2-+RNO). Therefore, increasing of this indicator is result of bacterial infection. Indications of other markers of inflammation: the number of leukocytes in venous blood and in a smear of vaginal contents, the level of C-RB did not significantly change in both PROM and IUI (p>0.1). Since the concentration index (NO2-+RNO) increased in almost all cases of PREM, unlike all other clinical and biochemical indicators used in modern medicine, there is an obvious sense of its use for the current monitoring of the health of pregnant women. But it is still impossible to say unequivocally about the possibility of monitoring the fetal health by concentration (NO2-+RNO) in the mother's blood.

[Investigation of the role of polymorphic loci RS2299941, RS1903858, RS10490920, RS2735343 of the PTEN gene in patients with prostate cancer]

Prostate cancer is a clinically heterogeneous disease, and accurate risk stratification of patients is becoming a key clinical task. This is the most common malignant neoplasm and the leading cause of cancer death in men worldwide. Genomic markers include tools and technologies that can predict the probability of an initial positive biopsy, reduce the number of unnecessary repeated biopsies, identify tumors with low, medium and high risk, classify the degree of disease, as well as predict and monitor the clinical response to intervention. Variants of the PTEN gene are of great interest as genetic markers of the risk of developing prostate malignancies.

The importance of laboratory parameters of the lipid transport system and adipose tissue hormones in assessing the course of chronic

The main manifestations of metabolic syndrome (MS) are disorders of carbohydrate and lipid metabolism and their hormonal regulation. The combined nature of metabolic disorders can significantly affect the course and prognosis of CHF in elderly people with metabolic syndrome. To determine the features of the combined effect of metabolic laboratory parameters and biological active factors of adipose tissue in patients with CHF and metabolic syndrome on the course of the disease. A comparison was made between a group of patients with CHF complicated by MS(n=37) and a group of patients with CHF without MS (n=37). The parameters of lipid metabolism (cholesterol CH and lipoproteins LP), the lipid transport system (ApoA1 and ApoB), leptin, adiponectin and resistin and their mutual relations were studied. The ratio of ApoB/ApoAI levels was indicative, which was 0.80±0.32 in patients with CHF without MS, and 1.12±0.46 in patients with CHF with MS (p <0.05). A significant correlation was found between the ratio of ApoB/ApoA1 levels and abdominal obesity (r=0.42, p<0.05), functional class of CHF (r=0.463, p<0.05), LDL-C level (r=0.518, p<0.05), and triglycerides (r=0.476, p<0.05). Also, significant results were obtained for the leptin/adiponectin ratio. For this ratio, 4 ranks were derived depending on the value of the leptin (ng/ml)/adiponectin (mcg/ml) ratio: less than 1 - rank 0 was assigned, with values of the ratio in the range 1 - 3 - rank 1, in the range 3.1 - 6 - rank 2, and above the value 6 - rank 3. Of the 22 patients who had improved CHF at the end of hospitalization, all at the beginning of hospitalization had a rank 0 or 1 ApoB/ApoA1 ratio. Thus, ranking the values of the ratio of ApoB/ApoA1 levels, and especially leptin/adiponectin, can suggest the probability of successful treatment of CHF or the probability of deterioration of the patient's condition, up to a fatal outcome.

The role of heterogeneous context shaping CSR practices in Russia

Goal: this в paper investigates the diversity of corporate social responsibility (CSR) practices in the Russian context. The purpose of this paper is to study how a heterogeneous context, commonly found in rising economies, shapes the emerging CSR practices of business organizations operating in Russia. Methodology: an institutional perspective that draws on the contextual multilevel approach guides our study. In our theoretical framing we assume that organizational fields play a key role in shaping CSR practices. This is applied to empirical investigation of organizational CSR practices. To inform our analysis we used desk research and an empirical dataset that consists of interviews with local business owners and managers representing a wide range of business organizations operating in Russia. Findings: based on an exploratory qualitative inquiry, we distinguish between four types of organizational CSR practices co-existing in Russia: global, crossvergent, authentic and irresponsible. Our findings demonstrate that business organizations populating one organizational field share homogeneous characteristics of CSR practices. Originality and contribution: the distinctions among CSR practices of business organizations belonging to different organizational fields are explained by the markets where they operate, core stakeholders, response mechanisms to prevailing institutional pressures and the dominant legacy of CSR.

Loss of swiss cheese in Neurons Contributes to Neurodegeneration with Mitochondria Abnormalities, Reactive Oxygen Species Acceleration and Accumulation of Lipid Droplets in Drosophila Brain

Various neurodegenerative disorders are associated with human NTE/PNPLA6 dysfunction. Mechanisms of neuropathogenesis in these diseases are far from clearly elucidated. Hereditary spastic paraplegia belongs to a type of neurodegeneration associated with NTE/PNLPLA6 and is implicated in neuron death. In this study, we used Drosophila melanogaster to investigate the consequences of neuronal knockdown of swiss cheese (sws)-the evolutionarily conserved ortholog of human NTE/PNPLA6-in vivo. Adult flies with the knockdown show longevity decline, locomotor and memory deficits, severe neurodegeneration progression in the brain, reactive oxygen species level acceleration, mitochondria abnormalities and lipid droplet accumulation. Our results suggest that SWS/NTE/PNPLA6 dysfunction in neurons induces oxidative stress and lipid metabolism alterations, involving mitochondria dynamics and lipid droplet turnover in neurodegeneration pathogenesis. We propose that there is a complex mechanism in neurological diseases such as hereditary spastic paraplegia, which includes a stress reaction, engaging mitochondria, lipid droplets and endoplasmic reticulum interplay.

Mitochondrion as a Selective Target for the Treatment of Atherosclerosis: Role of Mitochondrial DNA Mutations and Defective Mitophagy in the Pathogenesis of Atherosclerosis and Chronic Inflammation

BACKGROUND

Atherosclerosis is a chronic inflammatory condition that affects different arteries in the human body and often leads to severe neurological complications, such as stroke and its sequelae. Affected blood vessels develop atherosclerotic lesions in the form of focal thickening of the intimal layer, so called atherosclerotic plaques.

OBJECTIVES

Despite the high priority of atherosclerosis research for global health and the numerous preclinical and clinical studies conducted, currently, there is no effective pharmacological treatment that directly impacts atherosclerotic plaques. Many knowledge gaps exist in our understanding of the mechanisms of plaque formation. In this review, we discuss the role of mitochondria in different cell types involved in atherogenesis and provide information about mtDNA mutations associated with the disease.

RESULTS

Mitochondria of blood and arterial wall cells appear to be one of the important factors in disease initiation and development. Significant experimental evidence connects oxidative stress associated with mitochondrial dysfunction and vascular disease. Moreover, mitochondrial DNA (mtDNA) deletions and mutations are being considered as potential disease markers. Further study of mtDNA damage and associated dysfunction may open new perspectives for atherosclerosis treatment.

CONCLUSION

Mitochondria can be considered as important disease-modifying factors in several chronic pathologies. Deletions and mutations of mtDNA may be used as potential disease markers. Mitochondria-targeting antioxidant therapies appear to be promising for the development of treatment of atherosclerosis and other diseases associated with oxidative stress and chronic inflammation.

[Effect of 5-hydroxypyrimidine derivatives on tumor growth and cytokine concentration in blood serum of female CBA mice with cervical cancer (RSHM-5)]

The effects of intraperitoneal administration of SNK-411 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine) in a dose of 25 mg/kg (the total dose of 350 mg/kg) and SNK-578 (hydrochloride of 2-isobutyl-4,6-dimethyl-5- hydroxypyrimidine) in a dose of 10 mg/kg (the total dose of 140 mg/kg) on tumor growth and concentration of cytokines in the blood serum were studied in female CBA mice. Substances were administrated from the 2nd to 15th days of tumor development. Tumor growth inhibition (TGI) and serum cytokine level were studied on the 7th day after the end of compounds administration (21st day of tumor growth). In intact control group (n=10) median tumor mass was 1255 mg. TGI in the group of animals treated with SNK-411 was 47%; in the group of mice treated with SNK-578 TGI was 87%, tumor mass demonstrated 7.4-fold reduction. Serum concentrations of cytokines (IL-6, IL-10, IL-17A and IFN-γ) in tumor-bearing group of mice were higher versus the intact control group by 229%, 40%, 60% and 81%, respectively. Highly active SNK-578 decreased concentrations of prooncogenic IL-10, IL-17A and proinflammatory IL-6, by 61%, 70% and 29% as compared to tumor-bearing control group. SNK-411 decreased concentrations of prooncogenic IL-10 and IL-17A by 48% and 60%, respectively, and did not affect concentration of IL-6. Taking into consideration that IL-6 participates in autoimmune reactions, we can assume that the immune control is one of the crucial mechanisms of antitumor effect of SNK-578. All results are statistically significant.

[Changes in the mitochondrial subproteome of mouse brain Rpn13-binding proteins induced by the neurotoxin MPTP and the neuroprotector isatin]

Mitochondrial dysfunction and ubiquitin-proteasome system (UPS) failure contribute significantly to the development of Parkinson's disease (PD). The proteasome subunit Rpn13 located on the regulatory (19S) subparticle play an important role in the delivery of proteins, subjected to degradation, to the proteolytic (20S) part of proteasome. We have previously found several brain mitochondrial proteins specifically bound to Rpn13 (Buneeva et al. (2020) Biochemistry (Moscow), Supplement Series B: Biomedical Chemistry, 14, 297-305). In this study we have investigated the effect of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and the neuroprotector isatin on the mitochondrial subproteome of Rpn13-binding proteins of the mouse brain. Administration of MPTP (30 mg/kg) to animals caused movement disorders typical of PD, while pretreatment with isatin (100 mg/kg, 30 min before MPTP) reduced their severity. At the same time, the injection of MPTP, isatin, or their combination (isatin + MPTP) had a significant impact on the total number and the composition of Rpn13-binding proteins. The injection of MPTP decreased the total number of Rpn13-binding proteins in comparison with control, and the injection of isatin prior to MPTP or without MPTP caused an essential increase in the number of Rpn13-binding proteins, mainly of the functional group of proteins participating in the protein metabolism regulation, gene expression, and differentiation. Selected biosensor validation confirmed the interaction of Rpn13 subunit of proteasome with some proteins (glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, histones H2A and H2B) revealed while proteomic profiling. The results obtained testify that under the conditions of experimental MPTP-induced parkinsonism the neuroprotective effect of isatin may be aimed at the interaction of mitochondria with the components of UPS.

The difference between cellulolytic 'culturomes' and microbiomes inhabiting two contrasting soil types

High-throughput 16S rRNA sequencing was performed to compare the microbiomes inhabiting two contrasting soil types-sod-podzolic soil and chernozem-and the corresponding culturome communities of potentially cellulolytic bacteria cultured on standard Hutchinson media. For each soil type, soil-specific microorganisms have been identified: for sod-podzolic soil-Acidothermus, Devosia, Phenylobacterium and Tumebacillus, and for chernozem soil-Sphingomonas, Bacillus and Blastococcus. The dynamics of differences between soil types for bulk soil samples and culturomes varied depending on the taxonomic level of the corresponding phylotypes. At high taxonomic levels, the number of common taxa between soil types increased more slowly for bulk soil than for culturome. Differences between soil-specific phylotypes were detected in bulk soil at a low taxonomic level (genus, species). A total of 13 phylotypes were represented both in soil and in culturome. No relationship was shown between the abundance of these phylotypes in soil and culturome.

Optical Mapping-Validated Machine Learning Improves Atrial Fibrillation Driver Detection by Multi-Electrode Mapping

BACKGROUND

Atrial fibrillation (AF) can be maintained by localized intramural reentrant drivers. However, AF driver detection by clinical surface-only multielectrode mapping (MEM) has relied on subjective interpretation of activation maps. We hypothesized that application of machine learning to electrogram frequency spectra may accurately automate driver detection by MEM and add some objectivity to the interpretation of MEM findings.

METHODS

Temporally and spatially stable single AF drivers were mapped simultaneously in explanted human atria (n=11) by subsurface near-infrared optical mapping (NIOM; 0.3 mm² resolution) and 64-electrode MEM (higher density or lower density with 3 and 9 mm² resolution, respectively). Unipolar MEM and NIOM recordings were processed by Fourier transform analysis into 28 407 total Fourier spectra. Thirty-five features for machine learning were extracted from each Fourier spectrum.

RESULTS

Targeted driver ablation and NIOM activation maps efficiently defined the center and periphery of AF driver preferential tracks and provided validated annotations for driver versus nondriver electrodes in MEM arrays. Compared with analysis of single electrogram frequency features, averaging the features from each of the 8 neighboring electrodes, significantly improved classification of AF driver electrograms. The classification metrics increased when less strict annotation, including driver periphery electrodes, were added to driver center annotation. Notably, f1-score for the binary classification of higher-density catheter data set was significantly higher than that of lower-density catheter (0.81±0.02 versus 0.66±0.04, P<0.05). The trained algorithm correctly highlighted 86% of driver regions with higher density but only 80% with lower-density MEM arrays (81% for lower-density+higher-density arrays together).

CONCLUSIONS

The machine learning model pretrained on Fourier spectrum features allows efficient classification of electrograms recordings as AF driver or nondriver compared with the NIOM gold-standard. Future application of NIOM-validated machine learning approach may improve the accuracy of AF driver detection for targeted ablation treatment in patients.

Accumulation of elements by submerged (Stuckenia pectinata (L.) Börner) and emergent (Phragmites australis (Cav.) Trin. ex Steud.) macrophytes under different salinity levels

Accumulation of essential/beneficial and non-essential chemical elements by submerged (Stuckenia pectinata (L.) Börner) and emergent (Phragmites australis (Cav.) Trin. ex Steud.) rooted macrophytes in three water bodies was studied as dependent on water salinity (specific conductivity) and main environmental factors (temperature, pH of water, growing period, element contents in water and sediments). Inductively coupled plasma optical emission spectrometry (ICP - OES) was used for the element detection in the plants, sediments, and water. Multivariate statistics redundancy analysis (RDA) showed that investigated factors together explained 37.8 - 44.7% and 29.9 - 42.6% of the essential/beneficial and non-essential elements variability, respectively, whereas salinity was one of the main factors determining the accumulation of a number of elements (Mg, S, Na, Li, Sr, Sb) by the macrophytes. A decrease in the essential element contents (K, P, N, Cu, Zn) was observed in both species of the macrophytes during the growing season. Environmental factors (salinity, growing period, and pH) were more significant than the element contents in water and the sediments for the essential/beneficial element accumulation by two species of the macrophytes. The element contents in the sediments to a greater extent determined non-essential element accumulation by P. australis than by S. pectinata. The study showed that the efficiency of using P. australis and S. pectinata for remediation of aquatic ecosystems contaminated by heavy metals should not decrease with a salinity increase.

[Comparative effect of the prolyl endopeptidase inhibitors, benzyloxycarbonyl-prolyl-prolinal and benzyloxycarbonyl-methionyl-cyanopyrrolidine, on the acute exudative inflammation and visceral pain in mice]

A selective prolyl endopeptidase (PEP) inhibitor benzyloxycarbonyl-prolyl-prolinal (IC50 = 1,61±0,12 nmol/l) and a nonselective PEP inhibitor benzyloxycarbonyl-methionyl-cyanopyrrolidine (IC50 = 2,01±0,14 nmol/l) exhibit a comparable antiexudative effect at single doses of 2 mg/kg and 5 mg/kg (intraperitoneally) in outbred mice with peritonitis induced by 1% acetic acid. However, only benzyloxycarbonyl-methionyl-cyanopyrrolidine at a dose of 5 mg/kg reduces acetic acid induced pain in animals.

Genetics of Arterial-Wall-Specific Mechanisms in Atherosclerosis: Focus on Mitochondrial Mutations

PURPOSE OF REVIEW

Mutations in both nuclear and mitochondrial genes are associated with the development of atherosclerotic lesions in arteries and may provide a partial explanation to the focal nature of lesion distribution in the arterial wall. This review is aimed to discuss the genetic aspects of atherogenesis with a special focus on possible pro-atherogenic variants (mutations) of the nuclear and mitochondrial genomes that may be implicated in atherosclerosis development and progression.

RECENT FINDINGS

Mutations in the nuclear genes generally do not cause a phenotype restricted to a specific vascular wall cell and manifest themselves mostly at the organism level. Such mutations can act as important contributors to changes in lipid metabolism and modulate other risk factors of atherosclerosis. By contrast, mitochondrial DNA (mtDNA) mutations occurring locally in the arterial wall cells or in circulating immune cells may play a site-specific role in atherogenesis. The mosaic distribution of heteroplasmic mtDNA mutations in the arterial wall tissue may explain, at least to some extent, the locality and focality of atherosclerotic lesions distribution. The genetic mechanisms of atherogenesis include alterations of both nuclear and mitochondrial genomes. Altered lipid metabolism and inflammatory response of resident arterial wall and circulating immune cells may be related to mtDNA damage and defective mitophagy, which hinders clearance of dysfunctional mitochondria. Mutations of mtDNA can have mosaic distribution and locally affect functionality of endothelial and subendothelial intimal cells in the arterial wall contributing to atherosclerotic lesion development.

Endoplasmic Reticulum Stress in Macrophages: The Vicious Circle of Lipid Accumulation and Pro-Inflammatory Response

The endoplasmic reticulum (ER) stress is an important event in the pathogenesis of different human disorders, including atherosclerosis. ER stress leads to disturbance of cellular homeostasis, apoptosis, and in the case of macrophages, to foam cell formation and pro-inflammatory cytokines production. In atherosclerosis, several cell types can be affected by ER stress, including endothelial cells, vascular smooth muscular cells, and macrophages. Modified low-density lipoproteins (LDL) and cytokines, in turn, can provoke ER stress through different processes. The signaling cascades involved in ER stress initiation are complex and linked to other cellular processes, such as lysosomal biogenesis and functioning, autophagy, mitochondrial homeostasis, and energy production. In this review, we discuss the underlying mechanisms of ER stress formation and the interplay of lipid accumulation and pro-inflammatory response. We will specifically focus on macrophages, which are the key players in maintaining chronic inflammatory milieu in atherosclerotic lesions, and also a major source of lipid-accumulating foam cells.

Effects of 5-Hydroxypyrimidine Derivatives on Tumor Growth and Lifespan of C57BL/6 Mice with Epidermoid Lung Carcinoma

The effects of 5-hydroxypyrimidine derivatives SNK-411 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine) and SNK-578 (2-isobutyl-4,6-dimethyl-5-hydroxypyrimidine chlorohydrate) on the tumor growth and survival of male C57BL/6 mice with transplanted Lewis lung epidermoid carcinoma (LLC) were studied in animals receiving intraperitoneal treatment on days 2-15 of tumor development. Compound SNK-578 in a dose of 10 mg/kg significantly inhibited tumor growth (by 3.6 times; 72.2%) in 7 days after the treatment was discontinued, while compound SNK-411 in a dose of 25 mg/kg only negligibly reduced tumor volume (by 41.7%). A combination of course of SNK-411 (25 mg/kg) and single intraperitoneal dose of doxorubicin (4 mg/kg) significantly inhibited the tumor growth (by 2.2 times; 55.2%), while the combination of SNK-578 (10 mg/kg) with doxorubicin (4 mg/kg) was in fact ineffective. The median survival of animals with untreated LLC was 28 days. Median survival of mice injected with SNK-578 (10 mg/kg) was 43 days, hence, the lifespan of mice with LLC was by 38.6% longer after the treatment. Two of ten mice in this group developed no tumors.

NADPH Oxidases and Their Role in Atherosclerosis

The current view on atherosclerosis positions it as a multifactorial disorder that results from the interplay between lipid metabolism disturbances and inflammatory processes. Oxidative stress is proven to be one of the initiating factors in atherosclerosis development, being implicated both in the inflammatory response and in atherogenic modifications of lipoproteins that facilitate lipid accumulation in the arterial wall. The hallmark of oxidative stress is the elevated level of reactive oxygen species (ROS). Correspondingly, the activity of major ROS-generating enzymes, including nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, xanthine oxidases, and cyclooxygenases, is an important element in atherosclerosis development. In particular, the role of NADPH oxidases in atherosclerosis development has become a subject of intensive research. Aberrant activity of NADPH oxidases was shown to be associated with cardiovascular disease in humans. With regard to atherosclerosis, several important pathological components of the disease development, including endothelial dysfunction, inflammation, and vascular remodeling, involve aberrations in NADPH oxidases functioning. In humans, NADPH oxidases are represented by four isoforms expressed in vascular tissues, where they serve as the main source of ROS during atherogenesis. Moreover, recent studies have demonstrated their impact on vascular remodeling processes. Interestingly, one of the NADPH oxidase isoforms, NOX4, was shown to have an atheroprotective effect. Despite the growing evidence of the crucial involvement of NADPH oxidases in atherosclerosis pathogenesis, the available data still remains controversial. In this narrative review, we summarize the current knowledge of the role of NADPH oxidases in atherosclerosis and outline the future directions of research.

Gut microbiome: A possible common therapeutic target for treatment of atherosclerosis and cancer

Human gut microbiota is a dynamic and variable system that can change over time and in response to different diets and treatments. There is currently no doubt that gut microbiota can provide interesting therapeutic opportunities, since it can metabolize biologically active molecules, drugs, and their precursors, and control their bioavailability. Moreover, it can produce both beneficial and dangerous metabolites that influence host's health. In this review, we summarize the current knowledge on the involvement of gut microbiota in two chronic human pathologies that represent the greatest challenges of modern medicine: atherosclerosis and cancer. Interesting parallels are observed between the mechanisms and possible treatment approaches of these pathologies. Some of the common effects of therapeutic agents targeting both pathologies, such as anti-inflammatory activity, are partially mediated by the gut microbiota. We will discuss the effects of common drugs (metformin, statins and aspirin) and various nutraceuticals on gut microbiota and outline the pathways of microbial involvement in mediating the pleiotropic beneficial effects of these agents in atherosclerosis and cancer.

The Role of Mitochondria in Cardiovascular Diseases

The role of mitochondria in cardiovascular diseases is receiving ever growing attention. As a central player in the regulation of cellular metabolism and a powerful controller of cellular fate, mitochondria appear to comprise an interesting potential therapeutic target. With the development of DNA sequencing methods, mutations in mitochondrial DNA (mtDNA) became a subject of intensive study, since many directly lead to mitochondrial dysfunction, oxidative stress, deficient energy production and, as a result, cell dysfunction and death. Many mtDNA mutations were found to be associated with chronic human diseases, including cardiovascular disorders. In particular, 17 mtDNA mutations were reported to be associated with ischemic heart disease in humans. In this review, we discuss the involvement of mitochondrial dysfunction in the pathogenesis of atherosclerosis and describe the mtDNA mutations identified so far that are associated with atherosclerosis and its risk factors.

Thermal effects of monopolar electrosurgery detected by real-time infrared thermography: an experimental appendectomy study

Background

Monopolar energy (ME) is routinely used in appendectomy. This study aimed to investigate the degree of lateral thermal spread generated by ME and to evaluate the thermal injury sustained by the close-lying tissues.

Methods

Appendectomy with a monopolar Maryland dissector was performed in 8 rabbits (at 30 and 60 W power settings). A high-resolution infrared camera was used to record tissue heating during the intervention. After autopsy macroscopic changes were evaluated and tissue samples were subjected to myeloperoxidase (MPO) assay and histological examination.

Results

No significant differences in the extent of thermal spread, MPO activity and histological signs of inflammation were observed between groups. Regardless of the power settings, the heat spread exceeded 2 cm laterally along the mesoappendix when application time exceeded 3 s. The spread of heat through tubular structures in both groups caused a significant temperature rise in the nearby intestinal loop, resulting in perforation (n = 3) and necrosis (n = 1).

Conclusions

Application time is critical in thermal spread during appendectomy aided by ME. Tubular anatomic structures can enhance thermal injury on distant tissues. The observed effects of ME bear clinical relevance that need further investigation.

Possible Role of Mitochondrial DNA Mutations in Chronification of Inflammation: Focus on Atherosclerosis

Chronification of inflammation is the process that lies at the basis of several human diseases that make up to 80% of morbidity and mortality worldwide. It can also explain a great deal of processes related to aging. Atherosclerosis is an example of the most important chronic inflammatory pathology in terms of public health impact. Atherogenesis is based on the inflammatory response of the innate immunity arising locally or focally. The main trigger for this response appears to be modified low-density lipoprotein (LDL), although other factors may also play a role. With the quick resolution of inflammation, atherosclerotic changes in the arterial wall do not occur. However, a violation of the innate immunity response can lead to chronification of local inflammation and, as a result, to atherosclerotic lesion formation. In this review, we discuss possible mechanisms of the impaired immune response with a special focus on mitochondrial dysfunction. Some mitochondrial dysfunctions may be due to mutations in mitochondrial DNA. Several mitochondrial DNA mutations leading to defective mitophagy have been identified. The regulatory role of mitophagy in the immune response has been shown in recent studies. We suggest that defective mitophagy promoted by mutations in mitochondrial DNA can cause innate immunity disorders leading to chronification of inflammation.

Antiexudative Effects of Finasteride and a New Pyrazolo[C]Pyridine Derivative GIZh-72 in Acetic Acid-Induced Experimental Peritonitis

It was shown that finasteride, a 5α-reductase inhibitor (50 mg/kg, intraperitoneally) produced analgesic and antiexudative effects in experimental peritonitis induced by intraperitoneal injection of 1% acetic acid. These results agree with published data on its anti-inflammatory properties and ability to potentiate the analgesic effect of morphine in rodents. New pyrazolo[C] pyridine derivative GIZh-72 (4,6-dimethyl-2-(4-chlorphenyl)-2,3-dihydro-1H-pyrazolo[4,3-C]pyridine-3-on, chloral hydrate) injected intraperitoneally in doses of 20-80 mg/kg produced dose-dependent antiexudative effects, but exhibited no analgesic properties.

[Effect of cyanopyrrolidine derivatives on the activity of prolylendopeptidase, acute exudative inflammation and visceral pain in mice]

Cyanopyrrolidine derivatives benzyloxycarbonyl-methionyl-cyanopyrrolidine (ZMetPrdN), benzyloxycarbonylphenylalanyl- cyanopyrrolidine (ZPhePrdN), tert-butyl-hydroxycarbonyl-glycyl-cyanopyrrolidine (BocGlyPrdN), tert-butyl-hydroxycarbonyl-methionyl-cyanopyrrolidine (BocMetPrdN) are inhibitors of prolylendopeptidase (PREP; EC 3.4.21.26) with an IC50 of 2 nM to 12 nM. ZMetPrdN, ZPhePrdN and BocMetPrdN additionally inhibited dipeptidyl peptidase IV (DPP-4; EC 3.4.14.5) with an IC50 of 1100 nM to 3200 nM. All the compounds have antinociceptive properties in the acetic acid writhing test in mice. But only cyanopyrrolidine derivatives with aromatic substituents decrease exudative inflammation. The cyanopyrrolidine derivatives also increase PREP activity and compensatorily reduce DPP-4 activity in the serum of mice three hours after the induction of inflammation. Thus, cyanopyrrolidine derivatives exhibit antinociceptive and antiexudative properties in part via their effect on PREP.

[The effect of a neuroprotective dose of isatin or deprenyl to mice on the profile of brain isatin-binding proteins]

Isatin (indol-2,3-dione), an endogenous biofactor found in the brain, peripheral tissues and biological body fluids of humans and animals, exhibits a wide range of biological and pharmacological activities. They are realized via interaction with numerous isatin-binding proteins. Some of these proteins identified during proteomic profiling of the brain are involved in the development of neurodegenerative pathology. In the context of the neuroprotective effect, the effect of isatin is comparable to the effects of deprenyl (selegiline), a pharmacological agent used for treatment of Parkinson's disease. In this study, we have investigated the effect of a single dose administration of isatin (100 mg/kg) and deprenyl (10 mg/kg) to mice on the profile of the brain isatin-binding proteins. Comparative proteomic analysis of brain isatin-binding proteins of mice treated with isatin or deprenyl resulted in identification of a representative group of proteins (n=200) sensitive to the administration of these substances. The change in the profile of isatin-binding proteins may be obviously attributed to accumulation of isatin and deprenyl in the brain and their interaction with target proteins; this prevents protein binding to the affinity sorbent. Thus identified brain isatin-binding proteins of the control animals obviously represent specific targets that interact directly with isatin (and also with deprenyl) <i>in vivo</i>. Isatin or deprenyl administered to animals interact with these proteins and thus inhibit their binding to the affinity sorbent (immobilized isatin analogue).

[Comparison of standard and fast track rehabilitation in patients with acute appendicitis. Intermediate results of multicenter prospective randomized trial]

AIM

To analyze outcomes of fast track rehabilitation in patients with acute appendicitis.

MATERIAL AND METHODS

Prospective, randomized multi-center trial including 86 patients was conducted. There were 38 patients in the main group and 48 in the control group. All patients underwent laparoscopic appendectomy under endotracheal anesthesia. Protocol included informing, no premedication, glucose infusion prior to surgery, antibiotics administration, mesoappendix excision, limited deployment of drainage tubes, intraabdominal prolonged anesthesia, minimal pneumoperitoneum, limited irrigation, minimum power monopolar electrocautery, antiemetics, early activation and eating (2 and 6 hours after surgery). Pain was evaluated by visual-analogue scale. Auscultative peristalsis was considered every 2 hours after surgery. Cortisol level was assessed preoperatively, in 6 and 12-24 hours after surgery in 11 (29%) and 15 (31%) patients of the main and control groups respectively. Discharge criteria: no leukocytosis, fever and pain syndrome requiring anesthesia, no signs of complications and patient's consent.

RESULTS

Terms of disease, gender, age and comorbidities were similar in all patients. Duration of surgery under minimal pneumoperitoneum and standard pressure was also similar: 69.2±3.98 and 70.9±3.89 min (p=0.762). Pain syndrome grade and need for analgesics were significantly lower in the main group within entire follow-up. Pain syndrome was absent at the 1^st postoperative day in 16 (42%) and 2 (4.1%) patients of both groups, respectively (score 0-1). Phrenic nerve syndrome was observed in 36.8% of the main group and 60.4% of the control group (p=0.05). Incidence of dyspepsia and terms of peristalsis onset were similar. Length of hospital-stay was 1.45 days in the main group and 3.15 days in the control group (p=0.002). In the main group 18 (47%) patients were discharged on the first day after surgery. There were only 4 (8.3%) patients with similar hospital-stay in the control group (p<0.001). There were no repeated hospitalizations. Postoperative cortisol concentration was similar in both groups as well as in complicated and uneventful postoperative period. In the main group postoperative intestinal paresis (Clavien-Dindo grade 2) occurred in 1 patient. In the control group 7 patients had postoperative infiltrate and 1 patient - intestinal paresis (Clavien-Dindo grade 2). Postoperative drainage tube was deployed in 3 out of 7 patients with postoperative infiltrates and 6 of them received antibiotic therapy. Medication was successfully applied in all patients with complications.

CONCLUSION

There are some advantages of FTR for AA including reduced pain syndrome, morbidity and less length of hospital-stay. Issue of cortisol concentration requires further trials.

[Fast-track rehabilitation for acute cholecystitis: intermediate outcomes of prospective randomized trial]

AIM

To analyze an efficacy of FT-protocol in patients with acute cholecystitis.

MATERIAL AND METHODS

Prospective randomized study included 102 patients (45 of main group (FT) and 57 of control groups). Patients did not differ by TG13 severity index. The protocol included information, antibiotic prophylaxis, restriction of drainage, intraperitoneal anesthesia with long-term anesthetics, low pressure pneumoperitoneum, antiemetics in the presence of risk factors, early activation and feeding of the patient. Pain was assessed by VAS immediately after surgery, and 2, 6 and 12-24 hours postoperatively.

RESULTS

Surgery time was similar in both groups. Need for anesthesia and pain severity were significantly lower in the FT group. A total absence of pain (VAS 0-1) on the 1^st postoperative day was noted in 8 (17.7%) of the FT group and 2 (3.5%) patients of the control group (p=0.038). Shoulder pain developed in 4 (8.9%) cases of the main and 22 (38.6%) cases of the control group (p=0.001). Postoperative nausea developed in 13% of the FT group vs 40.5% in the control group (p=0.05). Hospital-stay was 1.29±0.7 days and 2.7±1.6 (p<0.0001), respectively. The time of the first stool was similar. Twenty-four (53.5%) patients of the FT group and 8,9% of the control group were discharged on 1^st postoperative day. There were 2 (IIIA) complications in the main group and 3 - in the control group (IIIA, IIIB and IV). There were no mortality and readmissions.

CONCLUSION

FT protocol in AC reduce postoperative pain, dyspepsia, shoulder pain and in-hospital stay with equal number of postoperative complications.

Decoupling between sulfate reduction and the anaerobic oxidation of methane in the shallow methane seep of the Black sea

Methane seepages are widespread in the Black Sea. However, microbiological research has been carried out only at the continental shelf seeps. The present work dealt with coastal gas seepages of the Kalamit Bay (Black Sea). High-throughput 16S rRNA gene sequencing and radiotracer analysis (14С and 35S) were used to determine the composition of the microbial community and the rates of microbial sulfate reduction and methane oxidation. The phylum Proteobacteria, represented mainly by sulfate reducers of the class Deltaproteobacteria, was the predominant in sequence dataset. Bacteroidetes and Planctomycetes were other numerous phyla. Among archaea, the phylum Woesearchaeota and Marine Benthic Group B were predominant in the upper horizons. Relative abundance of Euryarchaeota of the families Methanomicrobiaceae and Methanosarcinaceae (including ANME-3 archaea) increased in deeper sediment layers. Sulfate reduction rate (up to 2.9 mmol/L × day) was considerably higher than the rate of anaerobic methane oxidation (up to 43.4 μmol/L × day), which indicated insignificant contribution of anaerobic methane oxidation to the total sulfide production.

Investigation of the core microbiome in main soil types from the East European plain

The main goal of modern microbial ecology is to determine the key factors influencing the global diversity of microorganisms. Because of their complexity, soil communities are largely underexplored in this context. We studied soil genesis (combination of various soil-forming processes, specific to a particular soil type) that is driven by microbial activity. To investigate the interrelation between soil type and microbial diversity, we analyzed six soil types that are common in Russia, the Crimea, and Kazakhstan using 16S rDNA pyrosequencing. Soils of different types varied in the taxonomic composition of microbial communities. Their core microbiomes comprised 47 taxa within the orders Solirubrobacteriales and Hyphomicrobiaceae and the Gaiellaceae family. Two species from Bradyrhizobiaceae and Solirubrobactriaceae were present in all samples, whereas most other taxa were soil-type specific. Multiple resampling analysis revealed that two random soil samples from the same soil type shared more taxa than two samples from different types. The differences in community composition were mostly affected by the variation in pH values and exchangeable potassium content. The results show that data on the soil microbiome could be used for soil identification and clarification of their taxonomic position.

Blood Serum Atherogenicity: Cellular Test for the Development of Anti- Atherosclerotic Therapy

Atherosclerosis is one of the main problems in modern medical practice. This multifactorial disease can remain asymptomatic for a long time before manifesting itself in cardiovascular disorders, causing ischemic heart disease, myocardial infarction and even sudden death. Many synthetic drugs have been developed to reduce the symptoms of atherosclerosis, however, their efficacy in terms of reduction of atherosclerotic lesions progression is a matter of debate. Adverse effects of the exiting therapy should also be taken into account. The development of cellular models and improved understanding of the mechanisms of atherogenesis at the vascular wall level helped establishing the "direct anti-atherosclerosis therapy" approach. In this approach, the decrease of intracellular lipid deposition and atherogenicity of human blood serum are considered primary (direct) antiatherosclerotic effects. Screening of synthetic and natural substances for anti-atherosclerotic activity revealed a number of botanicals that could be used for direct anti-atherosclerotic therapy to treat early-stage atherosclerosis. As a result, 3 novel non-pharmaceutical products were developed (Allicor, Inflaminat and Karinat). Studies on in vitro and ex vivo models of atherogenesis confirmed their anti-atherosclerotic and anti-atherogenic activities and safety in patients. Clinical studies of Allicor, Inflminat and Karinat were carried out in subjects with diagnosed early stage atherosclerosis, demonstrating a clinically significant anti-atherosclerotic effect of the drugs. In this overview, we will present the complete process of the development of novel non-pharmaceutical products and report the results obtained in the conducted pre-clinical and clinical studies of these medications.

Cellular Composition of the B- and T-Cell-Dependent Areas in the Small Intestine during the Post-Stress Period (Experimental Study)

A quantitative study of lymphoid cells in the B- and T-cell-dependent areas of intestinal lymphoid nodules and mesenteric lymph nodes in behaviorally passive and active rats was performed at various periods after acute stress on the model of 1-h immobilization with simultaneous electrocutaneous stimulation. Stress exposure is accompanied by a decrease in the number of lymphoid cells in immunogenic structures of the gastrointestinal tract. Post-stress changes in the cytoarchitectonics of B- and T-cell-dependent areas in mesenteric lymph nodes of animals are less pronounced than in lymphoid nodules. Quantitative changes in lymphoid cells of B-cell-dependent areas in the small intestine of rats are greater than in T-cell-dependent areas. Changes in the cellular composition of immunogenic structures in the digestive system are most significant at the early stages of the post-stress period (1st week). Passive rats are characterized by significant changes in the cytoarchitectonics of B- and Tcell-dependent areas in the small intestine after extreme exposure, which illustrates functional exhaustion of the lymphoid tissue in stress-predisposed specimens.

[Effect of afobazole and levodopa on the activity of proline-specific proteinases and adenosine deaminase in blood serum and brain structures of rats with experimental Parkinson's syndrome induced by systemic administration of rotenone]

Rats with experimental Parkinson's syndrome induced by seven-day intraperitoneal administration of rotenone at a dose of 2.75 mg/kg have an increased activity of prolylendopeptidase (EC 3.4.21.26, PREP) in blood serum and a decreased activity of adenosine deaminase (EC 3.5.4.4, ADA) in serum and in the prefrontal cortex. PREP and ADA activity in other brain structures (in the striatum, hypothalamus and hippocampus) did not change; dipeptidyl peptidase IV activity (EC 3.4.14.5, DPP-4, CD26) also remained constant in serum and in all the brain structures investigated. Afobazole and levodopa, which exhibit antiparkinsonian activity in this model of Parkinson's syndrome, decrease elevated PREP activity in serum and increase reduced ADA activity in the prefrontal cortex of rats with the experimental pathology. Meanwhile, treatment with the study drugs was associated with a decrease of ADA activity in the other brain structures.

Activities of Proline-Specific Proteinases in the Serum and Cerebrospinal Fluid of Rats with the Fetal Valproate Syndrome

In 60-day-old Wistar rats with fetal valproate syndrome, the brain to body weight ratio was higher by 9.4% and activity of dipeptidyl peptidase IV in the serum and cerebrospinal fluid was higher by 18.4 and 40.6%, respectively, than in healthy controls. Activity of prolylendopeptidase in the serum and cerebrospinal fluid in rats with the fetal valproate syndrome did not differ from the control.

Effect of Concentration of Collagen Gel on Functional Activity of Bone Marrow Mesenchymal Stromal Cells

Collagen I gels with protein concentrations of 1, 2, and 3.5 mg/ml were prepared and embedded in a porous polylactide scaffold to reduce their contraction. Concentration of the gel did not affect its degradation. Collagen gels promoted the formation of cell networks. The cells in the collagen gel with a concentration of 1 mg/ml embedded in polylactide scaffold had elongated spindle-like shape, in contrast to flattened cells in collagen gel of the same concentration not embedded in the scaffold. Stabilization of the collagen gel in the polylactide scaffold promoted active synthesis of laminin and fibronectin by cells as soon as on day 5 of culturing in comparison with that in free collagen substrate.

The preservation of microbial DNA in archived soils of various genetic types

This study is a comparative analysis of samples of archived (stored for over 70–90 years) and modern soils of two different genetic types–chernozem and sod-podzolic soils. We revealed a reduction in biodiversity of archived soils relative to their modern state. Particularly, long-term storage in the museum exerted a greater impact on the microbiomes of sod-podzolic soils, while chernozem samples better preserved the native community. Thus, the persistence of microbial DNA in soil is largely determined by the physico-chemical characteristics that differ across soil types. Chernozems create better conditions for the long-term DNA preservation than sod-podzolic soils. This results in supposedly higher levels of biodiversity conservation in the microbiomes of chernozem with preservation of major microbial taxa dominant in the modern (control) soil samples, which makes archived chernozems a promising object for paleosoil studies.

Analysis of Apolipoprotein B Protein of Circulating Multiple-Modified Low-Density Lipoprotein

Modified low-density lipoprotein (LDL) is the main source of lipid accumulation in the arterial wall affected by atherosclerosis. We aimed to compare the properties of apolipoprotein B (apoB) from native and modified LDL. Modified (desialylated) LDL and native LDL were extracted from blood of atherosclerotic patients. We characterized apoB structure of LDL particles in total LDL preparation, circulating modified LDL (cmLDL), and native LDL. Intact cmLDL had a twofold lower content of free amino groups than native LDL. Delipidated apoB from cmLDL also had a lower content of free amino groups. The rates of tryptic hydrolysis and elastase digestion of cmLDL were twofold higher in comparison to native LDL. Therefore, cmLDL from atherosclerotic patients had altered apoB properties. Our observations strengthen the hypothesis of multiple modification of LDL in the bloodstream and underscore the importance of desialylated LDL as a possible marker of atherosclerosis.

Evaluation of carbohydrate-cysteamine thiazolidines as pro-drugs for the treatment of cystinosis

Cystinosis is a genetic disorder caused by malfunction of cystinosin and is characterized by accumulation of cystine. Cysteamine, the medication used in cystinosis, causes halitosis resulting in poor patient compliance. Halitosis is mainly caused by the formation of dimethylsulfide as the final product in the cysteamine metabolism pathway. We have synthesized carbohydrate-cysteamine thiazolidines, and hypothesized that the hydrolytic breakdown of cysteamine-thiazolidines can result in free cysteamine being released in target organs. To examine our hypothesis, we tested these analogs in vitro in patient-derived fibroblasts. Cystinotic fibroblasts were treated with different concentrations of arabinose-cysteamine, glucose-cysteamine and maltose-cysteamine. We demonstrated that the analogs break down into cysteamine extracellularly and might therefore not be fully taken up by the cells under the form of the pro-drug. Potential modifications of the analogs that enable their intracellular rather than extracellular breakdown, is necessary to pursue the potential of these analogs as pro-drugs.

Cellular models of atherosclerosis and their implication for testing natural substances with anti-atherosclerotic potential

BACKGROUND

Atherosclerosis remains a major problem in the modern society being a cause of life-threatening cardiovascular diseases. Subclinical atherosclerosis can be present for years before the symptoms become obvious, and first manifestations of the disease in a form of acute ischemia of organs are often fatal. The development of atherosclerosis is characterized by lipid accumulation in the aortic wall and formation of foam cells overloaded with large amounts of lipid inclusions in the cytoplasm. Current therapy of atherosclerosis is aimed mostly at the normalization of the blood lipid profile, and has no direct activity on the atherosclerotic plaque development. It is therefore necessary to continue the search for substances that possess a direct anti-atherosclerotic effect, preventing the cholesterol deposition in the arterial wall cells and reducing the existing plaques.

PURPOSE

Medicinal plants with potential anti-atherosclerotic activity are especially interesting in that regard, as plant-based medications are often characterized by good tolerability and are suitable for long-term therapy. The evaluation of novel active substances requires the establishment of reliable models of atherogenesis. In this review we discuss cellular models based on cultured human aortic cells. We also discuss several examples of successful application of these models for evaluation of anti-atherosclerotic activity of natural products of botanical origin based on measurable parameters, such as intracellular cholesterol accumulation.

CHAPTERS

We describe several examples of successful screening and clinical studies evaluating natural products that can be beneficial for prevention and treatment of atherosclerosis, including the subclinical (asymptomatic) forms.

CONCLUSION

Several substances of botanical origin have been demonstrated to be active for treatment and prevention of atherosclerosis. The obtained results encourage future studies of naturally occurring anti-atherosclerotic agents.

Carbohydrate composition of circulating multiple-modified low-density lipoprotein

Atherogenic modification of low-density lipoprotein (LDL) plays a crucial role in the pathogenesis of atherosclerosis, as modified LDL, but not native LDL, induces pronounced accumulation of cholesterol and lipids in the arterial wall. It is likely that LDL particles undergo multiple modifications in human plasma: desialylation, changes in size and density, acquisition of negative electric charge, oxidation, and complex formation. In a total LDL preparation isolated from pooled plasma of patients with coronary atherosclerosis and from healthy subjects, two subfractions of LDL could be identified: desialylated LDL bound by a lectin affinity column and normally sialylated (native) LDL that passed through the column. The desialylated LDL subfraction therefore represents circulating modified LDL. In this work, we performed a careful analysis of LDL particles to reveal changes in the composition of glycoconjugates associated with proteins and lipids. Protein fraction of LDL from atherosclerotic patients contained similar amounts of glucosamine, galactose, and mannose, but a 1.6-fold lower level of sialic acid as compared to healthy donors. Lipid-bound glycoconjugates of total LDL from patients with coronary atherosclerosis contained 1.5-2-fold less neutral monosaccharides than total LDL from healthy donors. Patient-derived LDL also contained significantly less sialic acid. Our results demonstrate that carbohydrate composition of LDL from atherosclerotic patients was altered in comparison to healthy controls. In particular, prominent decrease in the sialic acid content was observed. This strengthens the hypothesis of multiple modification of LDL particles in the bloodstream and underscores the clinical importance of desialylated LDL as a possible marker of atherosclerosis progression.

Ca(2+) signalling in human proximal tubular epithelial cells deficient for cystinosin

Nephropathic cystinosis is an autosomal recessive lysosomal storage disorder caused by loss-of-function mutations in the CTNS gene coding for the lysosomal cystine transporter, cystinosin. Recent studies have demonstrated that, apart from cystine accumulation in the lysosomes, cystinosin-deficient cells, especially renal proximal tubular epithelial cells are characterized by abnormal vesicle trafficking and endocytosis, possible lysosomal dysfunction and perturbed intracellular signalling cascades. It is therefore possible that Ca(2+) signalling is disturbed in cystinosis, as it has been demonstrated for other disorders associated with lysosomal dysfunction, such as Gaucher, Niemann-Pick type C and Alzheimer's diseases. In this study we investigated ATP-induced, IP3-induced and lysosomal Ca(2+) release in human proximal tubular epithelial cells derived from control and cystinotic patients. No major dysregulation of intracellular Ca(2+) dynamics was found, although ATP-induced Ca(2+) release appeared slightly sensitized in cystinotic cells compared to control cells. Hence, these subtle changes in Ca(2+) signals elicited by agonists may contribute to the pathogenesis of the disease.

Altered mTOR signalling in nephropathic cystinosis

Lysosomes play a central role in regulating autophagy via activation of mammalian target of rapamycin complex 1 (mTORC1). We examined mTORC1 signalling in the lysosomal storage disease nephropathic cystinosis (MIM 219800), in which accumulation of autophagy markers has been previously demonstrated. Cystinosis is caused by mutations in the lysosomal cystine transporter cystinosin and initially affects kidney proximal tubules causing renal Fanconi syndrome, followed by a gradual development of end-stage renal disease and extrarenal complications. Using proximal tubular kidney cells obtained from healthy donors and from cystinotic patients, we demonstrate that cystinosin deficiency is associated with a perturbed mTORC1 signalling, delayed reactivation of mTORC1 after starvation and abnormal lysosomal retention of mTOR during starvation. These effects could not be reversed by treatment with cystine-depleting drug cysteamine. Altered mTORC1 signalling can contribute to the development of proximal tubular dysfunction in cystinosis and points to new possibilities in therapeutic intervention through modulation of mTORC-dependent signalling cascades.

Cystinosin deficiency causes podocyte damage and loss associated with increased cell motility

The involvement of the glomerulus in the pathogenesis of cystinosis, caused by loss-of-function mutations in cystinosin (CTNS, 17p13), is a matter of controversy. Although patients with cystinosis demonstrate glomerular lesions and high-molecular-weight proteinuria starting from an early age, a mouse model of cystinosis develops only signs of proximal tubular dysfunction. Here we studied podocyte damage in patients with cystinosis by analyzing urinary podocyte excretion and by in vitro studies of podocytes deficient in cystinosin. Urine from patients with cystinosis presented a significantly higher amount of podocytes compared with controls. In culture, cystinotic podocytes accumulated cystine compatible with cystinosin deficiency. The expression of podocyte specific genes CD2AP, podocalyxin, and synaptopodin and of the WT1 protein was evident in all cell lines. Conditionally immortalized podocyte lines of 2 patients with different CTNS mutations had altered cytoskeleton, impaired cell adhesion sites, and increased individual cell motility. Moreover, these cells showed enhanced phosphorylation of both Akt1 and Akt2 (isoforms of protein kinase B). Inhibition of Akt by a specific inhibitor (Akti inhibitor 1/2) resulted in normalization of the hypermotile phenotype. Thus, our study extends the list of genetic disorders causing podocyte damage and provides the evidence of altered cell signaling cascades resulting in impaired cell adhesion and enhanced cell motility in cystinosis.