Pathogenetic Mechanisms Research Articles

Capsaicin Reduces Obesity by Reducing Chronic Low-Grade Inflammation.

Chronic low-grade inflammation (CLGI) is associated with obesity and is one of its pathogenetic mechanisms. Lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls, is the principal cause of CLGI. Studies have found that capsaicin significantly reduces the relative abundance of LPS-producing bacteria. In the present study, TRPV1-knockout (TRPV1-/-) C57BL/6J mice and the intestinal epithelial cell line Caco-2 (TRPV1-/-) were used as models to determine the effect of capsaicin on CLGI and elucidate the mechanism by which it mediates weight loss in vivo and in vitro. We found that the intragastric administration of capsaicin significantly blunted increases in body weight, food intake, blood lipid, and blood glucose in TRPV1-/- mice fed a high-fat diet, suggesting an anti-obesity effect of capsaicin. Capsaicin reduced LPS levels in the intestine by reducing the relative abundance of Proteobacteria such as Helicobacter, Desulfovibrio, and Sutterella. Toll-like receptor 4 (TLR4) levels decreased following decreases in LPS levels. Then, the local inflammation of the intestine was reduced by reducing the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 mediated by TLR4. Attenuating local intestinal inflammation led to the increased expression of tight junction proteins zonula occludens 1 (ZO-1) and occludin and the restoration of the intestinal barrier function. Capsaicin increased the expression of ZO-1 and occludin at the transcriptional and translational levels, thereby increasing trans-endothelial electrical resistance and restoring intestinal barrier function. The restoration of intestinal barrier function decreases intestinal permeability, which reduces the concentration of LPS entering the circulation, and reduced endotoxemia leads to decreased serum concentrations of inflammatory cytokines such as TNF-α and IL-6, thereby attenuating CLGI. This study sheds light on the anti-obesity effect of capsaicin and its mechanism by reducing CLGI, increasing our understanding of the anti-obesity effects of capsaicin. It has been confirmed that capsaicin can stimulate the expression of intestinal transmembrane protein ZO-1 and cytoplasmic protein occludin, increase the trans-epithelial electrical resistance value, and repair intestinal barrier function.

The Current Understanding of Molecular Mechanisms in Adenomyosis-Associated Infertility and the Treatment Strategy for Assisted Reproductive Technology.

Adenomyosis, endometriosis of the uterus, is associated with an increased likelihood of abnormal endometrial molecular expressions thought to impair implantation and early embryo development, resulting in disrupted fertility, including the local effects of sex steroid and pituitary hormones, immune responses, inflammatory factors, and neuroangiogenic mediators. In the recent literature, all of the proposed pathogenetic mechanisms of adenomyosis reduce endometrial receptivity and alter the adhesion molecule expression necessary for embryo implantation. The evidence so far has shown that adenomyosis causes lower pregnancy and live birth rates, higher miscarriage rates, as well as adverse obstetric and neonatal outcomes. Both pharmaceutical and surgical treatments for adenomyosis seem to have a positive impact on reproductive outcomes, leading to improved pregnancy and live birth rates. In addition, adenomyosis has negative impacts on reproductive outcomes in patients undergoing assisted reproductive technology. This association appears less significant after patients follow a long gonadotropin-releasing hormone agonist (GnRHa) protocol, which improves implantation rates. The pre-treatment of GnRHa can also be beneficial before engaging in natural conception attempts. This review aims to discover adenomyosis-associated infertility and to provide patient-specific treatment options.

Evaluating Phthalates and Bisphenol in Foods: Risks for Precocious Puberty and Early-Onset Obesity.

Recent scientific results indicate that diet is the primary source of exposure to endocrine-disrupting chemicals (EDCs) due to their use in food processing, pesticides, fertilizers, and migration from packaging to food, particularly in plastic or canned foods. Although EDCs are not listed on nutrition labels, their migration from packaging to food could inadvertently lead to food contamination, affecting individuals by inhalation, ingestion, and direct contact. The aim of our narrative review is to investigate the role of phthalates and bisphenol A (BPA) in foods, assessing their risks for precocious puberty (PP) and early-onset obesity, which are two clinical entities that are often associated and that share common pathogenetic mechanisms. The diverse outcomes observed across different studies highlight the complexity of phthalates and BPA effects on the human body, both in terms of early puberty, particularly in girls, and obesity with its metabolic disruptions. Moreover, obesity, which is independently linked to early puberty, might confound the relationship between exposure to these EDCs and pubertal timing. Given the potential public health implications, it is crucial to adopt a precautionary approach, minimizing exposure to these EDCs, especially in vulnerable populations such as children.

Correlates of disease severity in bluetongue as a model of acute arbovirus infection.

Most viral diseases display a variable clinical outcome due to differences in virus strain virulence and/or individual host susceptibility to infection. Understanding the biological mechanisms differentiating a viral infection displaying severe clinical manifestations from its milder forms can provide the intellectual framework toward therapies and early prognostic markers. This is especially true in arbovirus infections, where most clinical cases are present as mild febrile illness. Here, we used a naturally occurring vector-borne viral disease of ruminants, bluetongue, as an experimental system to uncover the fundamental mechanisms of virus-host interactions resulting in distinct clinical outcomes. As with most viral diseases, clinical symptoms in bluetongue can vary dramatically. We reproduced experimentally distinct clinical forms of bluetongue infection in sheep using three bluetongue virus (BTV) strains (BTV-1IT2006, BTV-1IT2013 and BTV-8FRA2017). Infected animals displayed clinical signs varying from clinically unapparent, to mild and severe disease. We collected and integrated clinical, haematological, virological, and histopathological data resulting in the analyses of 332 individual parameters from each infected and uninfected control animal. We subsequently used machine learning to select the key viral and host processes associated with disease pathogenesis. We identified and experimentally validated five different fundamental processes affecting the severity of bluetongue: (i) virus load and replication in target organs, (ii) modulation of the host type-I IFN response, (iii) pro-inflammatory responses, (iv) vascular damage, and (v) immunosuppression. Overall, we showed that an agnostic machine learning approach can be used to prioritise the different pathogenetic mechanisms affecting the disease outcome of an arbovirus infection.

The Kidney in Obesity: Current Evidence, Perspectives and Controversies.

As obesity and chronic kidney disease (CKD) remain a public health issue, we aim to elaborate on their complex relationship regarding pathogenetic mechanisms and therapeutic potential as well. The purpose of this review is to enhance our understanding of the interplay between obesity and CKD in order to timely diagnose and treat obesity-related CKD. Obesity and CKD pose significant intertwined challenges to global health, affecting a substantial portion of the population worldwide. Obesity is recognized as an independent risk factor, intricately contributing to CKD pathogenesis through mechanisms such as lipotoxicity, chronic inflammation, and insulin resistance. Recent evidence highlights additional factors including hemodynamic changes and intestinal dysbiosis that exacerbate kidney dysfunction in obese individuals, leading to histologic alterations known as obesity-related glomerulopathy (ORG). This narrative review synthesizes current knowledge on the prevalence, pathophysiology, clinical manifestations, and diagnostic strategies of obesity-related kidney disease. Furthermore, it explores mechanistic insights to delineate current therapeutic approaches, future directions for managing this condition and controversies. By elucidating the multifaceted interactions between obesity and kidney health, this review aims to inform clinical practice and stimulate further research to address this global health epidemic effectively.

GAB1 attenuates lipopolysaccharide‑mediated endothelial dysfunction via regulation of SOCS3.

Endothelial dysfunction is a crucial pathogenetic mechanism for sepsis. GRB2-associated binder 1 (GAB1) alleviates sepsis-induced multi-organ damage; however, to the best of our knowledge, its function in endothelial dysfunction in sepsis remains unclear. HUVECs were induced by lipopolysaccharide (LPS) to simulate endothelial cell injury under sepsis. Cell transfection was conducted to achieve GAB1 overexpression or suppressor of cytokine signaling 3 (SOCS3) knockdown. The expression levels of GAB1 and SOCS3 were detected by reverse transcription-quantitative PCR and western blotting. Cell viability, apoptosis and migration were assessed using Cell Counting Kit-8, TUNEL and wound healing assays, respectively. The production of cytokines and nitric oxide (NO) was detected using commercial kits. The interaction between GAB1 and SOCS3 was confirmed using a co-immunoprecipitation assay. GAB1 was downregulated in LPS-induced HUVECs. However, GAB1 overexpression significantly mitigated LPS-induced cell viability decrease and apoptosis in HUVECs, accompanied by upregulation of Bcl2 expression, and downregulation of Bax and cleaved caspase-3 expression. GAB1 also inhibited the production of pro-inflammatory cytokines and increased NO level, increased the levels of endothelial NO synthase (eNOS) and phosphorylated (p)-eNOS, and promoted migration in LPS-induced HUVECs. However, SOCS3 knockdown partially weakened the effects of GAB1 overexpression on cell viability, apoptosis, inflammation, p-eNOS, eNOS expression and NO levels in LPS-induced HUVECs. In addition, GAB1 and SOCS3 regulated Janus kinase 2 (JAK2)/STAT3 signaling in LPS-induced HUVECs. In conclusion, GAB1 exerted a protective effect against LPS-induced endothelial cell apoptosis, inflammation and dysfunction by modulating the SOCS3/JAK2/STAT3 signaling pathway.

Innovative methods for solving the problem of female infertility associated with endocrine disorders

Aim: to analyze the publications assessing innovative methods of diagnostics and treatment used to solve the problem of female infertility associated with endocrine disorders.Materials and Methods. There was conducted a search for publications in electronic databases PubMed, Google Scholar, and eLibrary, which were selected in accordance with the PRISMA guidelines. All relevant articles published up to January 2024 were included in thereview. As a result, 374 publications retrieved from PubMed, 147 – from eLibrary, and 33– from Google Scholar were extracted. Duplicates and non-full-text versions of articles were excluded. After the selection procedure, 72 publications were included in the review.Results. During the data analysis, we identified key aspects providing deeper understanding of endocrine disorders affecting female infertility. In particular, new correlations were demonstrated between the level of select hormones and treatment success, as well as pathogenetic mechanisms were also identified influencing the conception and pregnancy process. These results will allow to develop more accurate diagnostic criteria and effective treatment methods able to increase women's chances of successful conception and pregnancy.Conclusion. The data analysis identified the hallmark aspects for diagnostics and treatment of female endocrine infertility, with new diagnostic criteria and effective treatment methods identified able to markedly improve outcomes. The crucial potential of the innovative approaches and methods considered contributes to improving reproductive health and increasing the chances of successful conception. We strongly encourage the introduction of such advanced technologies into clinical practice to optimize reproductive success.

Mechanical Stretch Induces Senescence of Lung Epithelial Cells and Drives Fibroblast Activation by Paracrine Mechanisms.

Severe lung injury requiring mechanical ventilation may lead to secondary fibrosis. Senescence, a cell response characterized by cell cycle arrest and a shift towards a proinflammatory/profibrotic phenotype, is one of the involved mechanisms. Here, we explore the contribution of mechanical stretch as trigger of senescence of the respiratory epithelium and its link with fibrosis. Human lung epithelial cells and fibroblasts were exposed in vitro to mechanical stretch, and senescence assessed. In addition, fibroblasts were exposed to culture media preconditioned by senescent epithelial cells and their activation was studied. Transcriptomic profiles from stretched, senescent epithelial cells and activated fibroblasts were combined to identify potential activated pathways. Finally, the senolytic effects of digoxin were tested in these models. Mechanical stretch induced senescence in lung epithelial cells, but not in fibroblasts. This stretch-induced senescence has specific features compared to senescence induced by doxorubicin. Fibroblasts were activated after exposure to supernatants conditioned by epithelial senescent cells. Transcriptomic analyses revealed notch signaling as a potential responsible for the epithelial-mesenchymal crosstalk, as blockade of this pathway inhibits fibroblast activation. Treatment with digoxin reduced the percentage of senescent cells after stretch and ameliorated the fibroblast response to preconditioned media. These results suggest that lung fibrosis in response to mechanical stretch may be caused by the paracrine effects of senescent cells. This pathogenetic mechanism can be pharmacologically manipulated to improve lung repair.

Effect of interval hypoxytherapy on the immune status of hypertensive patients

In recent years, the role of sluggish nonspecific inflammation in the pathogenesis of hypertension has been proven. Oxidative stress that develops in hypertension leads to damage of endothelial glycocalyx with impaired barrier and adaptive functions of endothelium. Activation of transcription factor NF-kB leads to increased synthesis of free oxygen radicals, adhesion molecules (VCAM-1, ICAM-1, P-selectin, E-selectin) and proinflammatory cytokines (TNFα, IL-1, IL-6), triggering the inflammatory process in the endothelium. Modern antihypertensive drugs, affecting various pathogenetic mechanisms of arterial hypertension development, do not fully affect the immune component of arterial hypertension. Therefore, the search for various methods affecting the immunologic reactivity of hypertensive patients remains relevant in our time. The aim of the study was to reveal the effect of interval hypoxytherapy on the state of immunologic reactivity of patients with hypertension stage I. One hundred seventy male patients of 30-45 years old (mean age 38.36±1.64 years) with hypertension stage I (n = 170) who underwent combined treatment including drug therapy and normobaric interval hypoxic therapy in hypoxia-normoxia mode (oxygen content in hypoxic gas mixture was 20.9%) were examined. Indices of redox status and immunologic reactivity before and after interval hypoxytherapy were studied. Having a significant antioxidant effect, interval hypoxytherapy led to the subsidence of oxidative stress, which was indicated by an increase in the activity of superoxide dismutase and glutathione peroxidase in blood erythrocytes and a decrease in the content of malonic dialdehyde in blood as a result of a decrease in the generation of free oxygen radicals and suppression of lipid peroxidation processes. Interval hypoxytherapy resulted in a statistically significant increase in the initially decreased content of CD3+T lymphocytes (p 0.05), CD3+CD4+T lymphocytes (p 0.02), CD3+CD8+T lymphocytes (p 0.02). Initially increased number of B-lymphocytes CD19+, CD16+ lymphocytes, CD95+ lymphocytes significantly decreased. An important result of interval hypoxytherapy was a pronounced anti-inflammatory effect: statistically significant decrease in the content of pro-inflammatory interleukins IL-1β (p 0.02), IL-6 (p 0.01) and increase in the content of anti-inflammatory cytokines IL-4 (p 0.005) and IL-10 (p 0.005), which led to the subsidence of sluggish nonspecific inflammation. Suppression of oxidative stress and normalization of immunological reactivity of hypertensive patients after interval hypoxytherapy led to the subsidence of sluggish nonspecific inflammation, reduction of endothelial dysfunction and restoration of the structure and tone of the vascular wall with a decrease in blood pressure and improvement of the clinical course of hypertension.

Deficiency of Adenosine Deaminase 2

Adenosine deaminase 2 (ADA2) deficiency is an autosomal recessively inherited autoinflammatory disorder caused by loss-of-function mutations in the ADA2 gene. Although the pathogenesis involves the triggering of a proinflammatory cascade due to increased production of inflammatory cytokines such as tumor necrosis factor (TNF)-α and dysregulation of neutrophil extracellular trap formation resulting from an excess accumulation of extracellular adenosine, the pathogenetic mechanism still needs further clarification due to the broad clinical spectrum. In addition to the initially described vasculitis-related symptoms, hematological, immunological, and autoinflammatory symptoms are now well recognized. The diagnosis is made by demonstration of pathogenic variants of ADA2 with biallelic loss of function and identification of low plasma ADA2 catalytic activity. Currently, TNF-α inhibitors are the treatment of choice for controlling vasculitis manifestations and preventing strokes. However, in patients presenting with severe hematologic findings, TNF-α inhibitors are not the treatment of choice and hematopoietic stem cell transplantation has been shown to be successful in selected cases. Recombinant ADA2 protein and gene therapy are promising treatment modalities for the future. In conclusion, ADA2 deficiency has a broad phenotype and should be considered in the differential diagnosis of different clinical situations. In this review, we summarize the disease manifestations of ADA2 deficiency and available treatment options.

Urolithiasis in children and adults. Pathogenetic mechanisms of development and modern approaches to its prevention

Urolithiasis and crystalluria rank first in the structure of pathology of the uri nary system in children and adults. Despite a significant number of publications on urolithiasis, many issues of pathogenesis, the peculiarities of the course of its various types, and, especially, the prevention of the occurrence and metaphylaxis of its relaps es require further study. The analysis of modern literary sources presented in leading search engines, Russian and European clinical recommendations on this problem, as well as the results of our own research allowed us to identify the main pathogenetic links of the most common types of crystalluria and urolithiasis. Dietary and metabolic approaches and herbal therapy are proposed for the prevention and metaphylaxis of urolithiasis in children and adults.

Анальгетический потенциал витаминов группы В

B vitamins are the most important cofactors of axonal transport, neurotransmitter synthesis and many cellular metabolic pathways. B vitamins (B1 – thiamine, B6 – pyridoxine, B12 – cyanocobalamin) neurotropic role has long been discussed as modulators of inflammation and pain. The analgesic effect of neurotropic B vitamins is known for oral administration and parenteral administration, both in animal model experiments and in clinical practice. Each of the B vitamins participates in energy, fat, protein, water-salt metabolism, has a regulating effect on the trophism and the nervous system. Synergistic interactions have been proven: intra-group accumulation of the effects of B vitamins, and potentiation of the action of medicine drugs of other groups (nonsteroidal anti-inflammatory drugs (NSAIDs), anticonvulsants) when administered together with vitamins of group B. Vitamins of group B suppress the activity of proinflammatory mediators, regulate neurotransmitters of nociceptive and neuropathic pain. Some of these processes include targeted activation of the descending pain modulation system and specific intracellular pathways that have anti-inflammatory, antioxidant and regenerating effects on the nervous system. The analgesic efficacy of B vitamins has been demonstrated both in monotherapy and in complex therapy together with NSAIDs in the treatment of patients with lower back pain, polyneuropathy of various etiologies (diabetic, alcoholic, toxic). The effectiveness of the complex of high-dose B vitamins exceeds the effectiveness of monotherapy with one of the vitamins. Vitamin B12 enhances the antinociceptive effect of NSAIDs to a greater extent than B1 and B6, therefore, in clinical practice it is recommended to use a complex of vitamins of this group. The use of a combination of B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) with choline, inosine and paraaminobenzoic acid in chronic pain is justified, since they affect the pathogenetic mechanisms of pain formation. Drug, containing a complex of 11 B vitamins, may be used for chronic pain syndrome.

Characteristics of myelinated retinal nerve fibres in associated straatsma syndrome.

To study cases diagnosed of myelinated retinal nerve fibres (MRNF) continuous with the optic disc and describe the plausible pathogenic mechanism for the ocular features in Straatsma syndrome. This retrospective observational study includes clinically diagnosed MRNF cases. MRNF, myopia, and amblyopia defined Straatsma syndrome. MRNF were classified into three types based on location: type 1 in the superior retina, type 2 in the superior and inferior retina, and type 3 in the inferior retina. MRNF size was measured on Optomap® (Optos, Daytona, UK) images and posterior staphyloma location was noted. Demographics and best-corrected refractive error in logMAR units was recorded. Descriptive statistics and Spearman's corelation test were used to analyse MRNF size's relationship to refractive error and logMAR visual acuity. The study included a total of 19 MRNF eyes from 18 patients. Seventeen (89%) eyes had Straatsma syndrome. Median age was 23.50 [range: 4-75] years. One (6%) patient exhibited bilateral presentation. The median logMAR visual acuity was 0.4 log units (interquartile range: 0.18-1.20) and mean refractive error was -7.21 ± 5.32. Type 2 MRNF (n = 14,74%) was the commonest. Average MRNF size was 34.37 ± 40.73 sq.mm. Posterior staphyloma was noted in 17 eyes, all in close MRNF association. Significant positive corelation was noted between logMAR visual acuity and MRNF size (r = 0.5, p = 0.028). Large size MRNF corelated with poor visual acuity in the study. The paper explains the possible pathogenetic mechanisms for the ocular findings seen in MRNF.

Isolation of donor gamma globulin obtained from multiparous women and its effects upon expression of HLA-G and HLA-DR molecules on lymphocytes from mothers of children with septal congenital heart defects

A common pathogenetic mechanism of reproductive losses and congenital heart disease (CHD) is associated with immune inflammation in the “mother-embryo” system which affects differentiation and proliferation of cardiovascular progenitor cells. It is hypothesized that this link may be blocked by regulatory auto- and alloimmune antibodies to HLA-G and HLA-DR molecules. Moreover, these antibodies may be present at sufficient amounts in donor immunoglobulins, especially those obtained from the blood of multiparous women. Based on this suggestion, the aim of our study was to obtain enriched gamma globulin fraction from the blood of multiparous women and evaluate its functional effects towards HLA-DR and HLA-G molecules. Isolation of the gammaglobulin fraction (GGF) from the blood plasma of multiparous women was performed using affinity chromatography in several sessions. Purity grade of the resulting protein was analyzed by immunoelectrophoresis, electrophoretic separation of the protein fraction of blood serum and electrophoresis in 4.12% polyacrylamide gel with the addition of SDS (PAGE electrophoresis). PAAG electrophoresis showed that this GGF did not differ from commercial therapeutic intravenous immunoglobulin (IVIG). Assessment of the functional activity of GGF upon HLA-DR and HLA-G molecules was performed in the main group of women and their children with congenital heart disease (n = 38), and control group of women who gave birth to conditionally healthy children (n = 21). To determine the specificity of GGF with respect to HLA-G, HLA-DR molecules, as well as to compare its effect with autologous and allogeneic sera and IVIG, we developed an immunological testing protocol using flow cytometry. The protocol was arranged on the basis of the methodology of “cross-match” approach and Russian patent “Method for determining antibodies to HLA-G”. It was found that the blocking activity of female serum towards autologous (intrinsic) and allogeneic (embryo/fetus/child) HLA-G and HLA-DR molecules may determine the protective effect on development of congenital heart defects in the next generation. Donor human immunoglobulin showed a similar blocking effects to these molecules, possibly due to the presence of alloimmune antibodies to HLA classes I and II. The gammaglobulin fraction obtained from the donor blood of multiparous women has a more pronounced blocking effect on the HLA-G and HLA-DR expression. Hence, this immunobiological preparation can be considered a prototype of therapeutic and prophylactic agent blocking the genesis of congenital heart defects.

Toll-Like Receptor 7-Expressed Macrophages Are Involved in the Pathogenesis of Esophageal Achalasia and Esophagogastric Junction Outflow Obstruction.

Esophageal achalasia is a typical esophageal motility disorder (EMD). Although viral infections have been hypothesized to play a role in the pathogenesis of esophageal achalasia, its etiology remains unclear. This study used esophageal muscle layer specimens collected during per-oral endoscopic myotomy (POEM) procedures to investigate the association between esophageal achalasia and esophagogastric junction outflow obstruction (EGJOO) and pattern recognition receptors. Patients with esophageal achalasia and EGJOO who underwent POEM were allocated to the EMD group. Biopsies of the inner circular muscle were conducted during the POEM procedure. The control group comprised individuals diagnosed with esophageal squamous cell carcinoma who underwent surgical resection. Expression of pattern recognition receptors, including Toll-like receptor (TLR) 7, was examined by polymerase chain reaction. Immunohistochemical staining was performed to determine TLR7 expression sites in the esophageal muscle layer, and the relationship between TLR7 mRNA expression and clinical score was investigated. Our analysis revealed a notable upregulation of TLR7 mRNA levels within the muscle layer of esophageal achalasia and EGJOO, in contrast to those of control specimens. In contrast, the correlation between TLR7 and clinical score was not significant. Immunohistochemical staining revealed increased numbers of TLR7-expressing macrophages between the muscle layers. TLR7-expressing macrophages are involved in the innate immune response underlying esophageal achalasia and EGJOO. This result will lead to the elucidation of new pathogenetic mechanisms and the development of novel therapeutic targets.

O-glycosylation of IgA1 and the pathogenesis of an autoimmune disease IgA nephropathy.

IgA nephropathy is a kidney disease characterized by deposition of immune complexes containing abnormally O-glycosylated IgA1 in the glomeruli. Specifically, some O-glycans are missing galactose that is normally β1,3-linked to N-acetylgalactosamine of the core 1 glycans. These galactose-deficient IgA1 glycoforms are produced by IgA1-secreting cells due to a dysregulated expression and activity of several glycosyltransferases. Galactose-deficient IgA1 in the circulation of patients with IgA nephropathy is bound by IgG autoantibodies and the resultant immune complexes can contain additional proteins, such as complement C3. These complexes, if not removed from the circulation, can enter the glomerular mesangium, activate the resident mesangial cells, and induce glomerular injury. In this review, we briefly summarize clinical and pathological features of IgA nephropathy, review normal and aberrant IgA1 O-glycosylation pathways, and discuss the origins and potential significance of natural anti-glycan antibodies, namely those recognizing N-acetylgalactosamine. We also discuss the features of autoantibodies specific for galactose-deficient IgA1 and the characteristics of pathogenic immune complexes containing IgA1 and IgG. In IgA nephropathy, kidneys are injured by IgA1-containing immune complexes as innocent bystanders. Most patients with IgA nephropathy progress to kidney failure and require dialysis or transplantation. Moreover, most patients after transplantation experience a recurrent disease. Thus, a better understanding of the pathogenetic mechanisms is needed to develop new disease-specific treatments.

Metabolic Associated Fatty Liver Disease in Children and Adolescents: Mechanisms of a Silent Epidemic and Therapeutic Options.

Non-alcoholic fatty liver disease (NAFLD) is now identified as a hepatic sign of metabolic syndrome and is the most frequent cause of chronic liver disease in all ages. It is assumed that a genetic predisposition associated with epigenetic factors participates in the evolution of this condition. Visceral obesity and insulin resistance (IR) have always been considered the most important causative factors of Metabolic Syndrome (MetS) and NAFLD, but currently, the interaction between genetic heritage and environmental factors is increasingly considered fundamental in the genesis of metabolic disorders associated with NAFLD. In fact, in patients with NAFLD, insulin resistance, arterial hypertension, abdominal obesity, dyslipidemia and reduced intestinal permeability have often been found, as well as a higher prevalence of coronary artery disease, obstructive sleep apnea, polycystic ovary syndrome and osteopenia, which define a MetS framework. Early diagnosis is needed to prevent disease progression through primarily lifestyle interventions. Unfortunately, at present, there are no molecules recommended for pediatric patients. However, several new drugs are in clinical trials. For this reason, targeted studies on the interaction between genetics and environmental factors involved in the development of NAFLD and MetS and on the pathogenetic mechanisms that determine the evolution in non-alcoholic steatohepatitis (NASH), should be implemented. Therefore, it is desirable that future studies may be useful in identifying patients at risk of developing NAFLD and MetS early.

Unraveling the Missing Pieces: Exploring the Gaps in Understanding Chagas Cardiomyopathy.

Chagas cardiomyopathy affects a considerable number of patients infected with the protozoan Trypanosoma cruzi (T. cruzi) and remains one of the mostneglected tropical diseases despite being a significant contributor to morbidity and mortality in both endemic regions of Latin America and non-endemic countries like the United States. Since its discovery almost a century ago, knowledge gaps still exist in the mechanisms involved in the pathogenesis of Chagas cardiomyopathy, and numerous challenges exist in its diagnosis and treatment. This article reviews the main pathogenetic mechanisms involved in the progression of Chagas cardiomyopathy, which has been proposed as a result of years of research. It also emphasizes the challenges involved in the diagnosis of the asymptomatic indeterminate phase and has focused on several diagnostic techniques, including echocardiography, electrocardiogram (ECG), magnetic resonance imaging (MRI), and nuclear imaging in diagnosing symptomatic Chagas cardiomyopathy. In this article, we have also provided a brief overview of the current treatment of Chagas cardiomyopathy, which is not etiology-specific but insteadderived from the knowledge acquired from the treatment of other cardiomyopathies.

NMDA Receptors and Indices of Energy Metabolism in Erythrocytes: Missing Link to the Assessment of Efficiency of Oxygen Transport in Hepatic Encephalopathy.

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome that develops in patients with severe liver dysfunction and/or portocaval shunting. Despite more than a century of research into the relationship between liver damage and development of encephalopathy, pathogenetic mechanisms of hepatic encephalopathy have not yet been fully elucidated. It is generally recognized, however, that the main trigger of neurologic complications in hepatic encephalopathy is the neurotoxin ammonia/ammonium, concentration of which in the blood increases to toxic levels (hyperammonemia), when detoxification function of the liver is impaired. Freely penetrating into brain cells and affecting NMDA-receptor-mediated signaling, ammonia triggers a pathological cascade leading to the sharp inhibition of aerobic glucose metabolism, oxidative stress, brain hypoperfusion, nerve cell damage, and formation of neurological deficits. Brain hypoperfusion, in turn, could be due to the impaired oxygen transport function of erythrocytes, because of the disturbed energy metabolism that occurs in the membranes and inside erythrocytes and controls affinity of hemoglobin for oxygen, which determines the degree of oxygenation of blood and tissues. In our recent study, this causal relationship was confirmed and novel ammonium-induced pro-oxidant effect mediated by excessive activation of NMDA receptors leading to impaired oxygen transport function of erythrocytes was revealed. For a more complete evaluation of "erythrocytic" factors that diminish brain oxygenation and lead to encephalopathy, in this study, activity of the enzymes and concentration of metabolites of glycolysis and Rapoport-Lubering shunt, as well as morphological characteristics of erythrocytes from the rats with acute hyperammoniemia were determined. To elucidate the role of NMDA receptors in the above processes, MK-801, a non-competitive receptor antagonist, was used. Based on the obtained results it can be concluded that it is necessary to consider ammonium-induced morphofunctional disorders of erythrocytes and hemoglobinemia which can occur as a result of alterations in highly integrated networks of metabolic pathways may act as an additional systemic "erythrocytic" pathogenetic factor to prevent the onset and progression of cerebral hypoperfusion in hepatic encephalopathy accompanied by hyperammonemia.

Estimating three-dimensional foot bone kinematics from skin markers using a deep learning neural network model

The human foot is a complex structure comprising 26 bones, whose coordinated movements facilitate proper deformation of the foot, ensuring stable and efficient locomotion. Despite their critical role, the kinematics of foot bones during movement remain largely unexplored, primarily due to the absence of non-invasive methods for measuring foot bone kinematics. This study addresses this gap by proposing a neural network model for estimating foot bone movements using surface markers. To establish a mapping between the positions and orientations of the foot bones and 41 skin markers attached on the human foot, computed tomography scans of the foot with the markers were obtained with eleven healthy adults and thirteen cadaver specimens in different foot postures. The neural network architecture comprises four layers, with input and output layers containing the 41 marker positions and the positions and orientations of the nine foot bones, respectively. The mean errors between estimated and true foot bone position and orientation were 0.5 mm and 0.6 degrees, respectively, indicating that the neural network can provide 3D kinematics of the foot bones with sufficient accuracy in a non-invasive manner, thereby contributing to a better understanding of foot function and the pathogenetic mechanisms underlying foot disorders.