Relationships between Osteopontin, Osteoprotegerin, and Other Extracellular Matrix Proteins in Calcifying Arteries

Osteopontin (OPN) and osteoprotegerin (OPG) are glycoproteins that participate in the regulation of tissue biomineralization. The aim of the project is to verify the hypothesis that the content of OPN and OPG in the aorta walls increases with the development of atherosclerosis and that these proteins are quantitatively related to the main proteins in the extracellular arteries matrix. Quantitative and qualitative analyses of the OPN and OPG content in 101 aorta sections have been conducted. Additionally, an enzyme-linked immunosorbent assay (ELISA) test has been performed to determine the collagen types I-IV and elastin content in the tissues. Correlations between the biochemical data and patients' age/sex, atherosclerosis stages, and calcification occurrences in the tissue have been established. We are the first to report correlations between OPN or OPG and various types of collagen and elastin content (OPG/type I collagen correlation: r = 0.37, p = 0.004; OPG/type II collagen: r = 0.34, p = 0.007; OPG/type III collagen: r = 0.39, p = 0.002, OPG/type IV collagen: r = 0.27, p = 0.03; OPG/elastin: r = 0.42, p = 0.001; OPN/collagen type I: r = 0.34, p = 0.007; OPN/collagen type II: r = 0.52, p = 0.000; OPN/elastin: r = 0.61, p = 0.001). OPN overexpression accompanies calcium deposit (CA) formation with the protein localized in the calcium deposit, whereas OPG is located outside the CA. Although OPN and OPG seem to play a similar function (inhibiting calcification), these glycoproteins have different tissue localizations and independent expression regulation. The independent expression regulation presumably depends on the factors responsible for stimulating the synthesis of collagens and elastin.

3D reconstruction of events: Search for a spatial correlation between injuries and the geometry of the body discovery site

The aim of the study was to assess the usefulness of analysing visual material in a 3D environment when examining spatial interrelations between the incident participants, tools, and space surrounding the incident site. Such analysis may provide information about the trauma mechanism, which may lead to the determination of probable events. This paper points to the potential of conducting research under 3D environment conditions on the example of a specific criminal incident-a suspected homicide. The aim of the study was to identify possible circumstances of the events with particular emphasis on the mechanism of death and the involvement of third parties. It was performed a comprehensive 3D reconstruction of the elements of the incident using different sources and forms of evidence, and consequently also different imaging, analysis, and synthesis technologies. The resulting 3D reconstruction and animation of the possible events serve to verify the investigative hypotheses. The paper combines a technical description of the research methodology with a forensic commentary, which ultimately creates an integral synthesis of the medicolegal assessment for trial purposes, while presenting the effectiveness of the research methods used. To sum up, the paper presents an experiment carried out under virtual conditions, impossible to execute under real conditions but critical for trial case analysis.

Association between skin lymphangiogenesis parameters and arterial hypertension status in patients: An observational study

BACKGROUND

Recent studies have indicated that the skin lymphatic system and interstitium may play a role in the pathophysiology of arterial hypertension (AH).

OBJECTIVES

We aimed to determine whether the set of pathway parameters described previously in rodents would allow for the distinction between hypertensive and normotensive patients.

MATERIAL AND METHODS

Molecular and histopathological parameters from the skin and blood of patients with AH (AH group, n = 53), resistant AH (RAH group, n = 32) and control (C group, n = 45) were used, and a statistical multivariate bootstrap methodology combining partial least squares-discriminant analysis (PLS-DA) and selectivity ratio (SR) were applied.

RESULTS

The C vs RAH model presented the best prediction performance (AUC test = 0.90) and had a sensitivity and specificity of 73.68% and 83.33%, respectively. However, the parameters selected for the C vs AH group model were the most important for the pathway described in the rodent model, i.e., greater density of the skin lymphatic vessels (D2-40 expression) and greater number of macrophages (CD68 expression), higher expression of the messenger ribonucleic acid (mRNA) of nuclear factor of activated T cells 5 (NFAT5), vascular endothelial growth factor C (VEGFC) and podoplanin (PDPN) in the skin, greater concentration of hyaluronic acid (HA) in the skin, and lower serum concentration of VEGF-C.

CONCLUSIONS

Our study suggests that the NFAT5/VEGF-C/lymphangiogenesis pathway, previously described in rodent studies, may also be present in human HA. Further experiments are needed to confirm our findings.

Effect of advanced glycation end-products in a wide range of medical problems including COVID-19

Glycation is a physiological process that determines the aging of the organism, while in states of metabolic disorders it is significantly intensified. High concentrations of compounds such as reducing sugars or reactive aldehydes derived from lipid oxidation, occurring for example in diabetes, atherosclerosis, dyslipidemia, obesity or metabolic syndrome, lead to increased glycation of proteins, lipids and nucleic acids. The level of advanced glycation end-products (AGEs) in the body depends on rapidity of their production and the rate of their removal by the urinary system. AGEs, accumulated in the extracellular matrix of the blood vessels and other organs, cause irreversible changes in the biochemical and biomechanical properties of tissues. As a consequence, micro- and macroangiopathies appear in the system, and may contribute to the organ failure, like kidneys and heart. Elevated levels of AGEs also increase the risk of Alzheimer's disease and various cancers. In this paper, we propose a new classification due to modified amino acid residues: arginyl-AGEs, monolysyl-AGEs and lysyl-arginyl-AGEs and dilysyl-AGEs. Furthermore, we describe in detail the effect of AGEs on the pathogenesis of metabolic and old age diseases, such as diabetic complications, atherosclerosis and neurodegenerative diseases. We summarize the currently available data on the diagnostic value of AGEs and present the AGEs as a therapeutic goal in a wide range of medical problems, including SARS-CoV-2 infection and so-called long COVID.

Advanced Glycation End-Products in Blood Serum-Novel Ischemic Stroke Risk Factors? Implication for Diabetic Patients

New predictors of ischemic incidents are constantly sought since they raise the awareness of patients and their doctors of stroke occurrence. The goal was to verify whether Advanced Glycation End Products (AGEs), in particular AGE10, could be one of them. The AGE10 measurement was conducted using a non-commercial ELISA assay in the blood serum of neurological patients without cerebrovascular event (n = 24), those with transient brain attack (TIA) (n = 17), and severe ischemic stroke (n = 35). Twice as many of the people with TIA or severe stroke presented high AGE10 serum concentrations compared to the patients with other neurological conditions (χ2 = 8.2, p = 0.004; χ2 = 8.0, p = 0.005, respectively). The risk of ischemic incident was significantly risen in people with higher levels of AGE10 (OR = 6.5, CI95%: 1.7-24.8; OR = 4.7, CI95%: 1.5-14.5 for TIA and stroke subjects, respectively). We observed a positive correlation (r = 0.40) between high AGE10 levels and diabetes. Moreover, all the diabetic patients that had a high AGE10 content experienced either a severe ischemic stroke or TIA. The patients with high levels of AGE10 exhibited higher grades of disability assessed by the NIHSS scale (r = 0.35). AGE10 can be considered a new biomarker of ischemic stroke risk. Patients with diabetes presenting high AGE10 levels are particularly prone to the occurrence of cerebrovascular incidents.

Association between Leukocyte Cell-Derived Chemotaxin 2 and Metabolic and Renal Diseases in a Geriatric Population: A Pilot Study

LECT2 is not a routine diagnostic marker for any disease, but it has been associated with many pathologies, including systemic amyloidosis, rheumatoid arthritis, diabetes, atherosclerosis, and metabolic syndrome. With human aortic sections (n = 22) and sera from geriatric subjects (n = 79), we analyzed the relationships that could be observed between this protein and other parameters related to metabolic diseases. As a result, we observed a relatively high (r~0.8, p < 0.05) positive correlation between SRA and LECT2 and a negative correlation between EGFR and LECT2 (r~-0.4, p < 0.05). We observed LECT2 expression in macrophages, myocytes, and other aortic cells, with a tendency to be overexpressed in developed atherosclerotic plaques. We conclude that LECT2 exerts its chemotactic effects not only as a protein synthesized in the liver and secreted and circulating in the blood but also as a locally expressed protein within atherosclerotic plaque development. The LECT2-EGFR correlation suggests an association of this protein with loss of normal renal function. This fact can be associated with LECT2 amyloidosis, although it should be verified whether in the geriatric population there is indeed a widespread accumulation of LECT2 with the progression of aging or whether it is rather a marker of general deterioration of renal function.

Sodium accumulation in the skin is associated with higher density of skin lymphatic vessels in patients with arterial hypertension

PURPOSE

Recent studies, conducted mainly on the rodent model, have demonstrated that regulatory pathway in the skin provided by glycosaminoglycans, nuclear factor of activated T cells 5 (NFAT5), vascular endothelial growth factor C (VEGF-C) and process of lymphangiogenesis may play an important role in extrarenal regulation of sodium (Na+) balance, body water volume, and blood pressure. We aimed to investigate the concentrations and relations among the main factors of this pathway in human skin to confirm that this regulatory axis also exists in humans.

PATIENTS AND METHODS

Skin specimens from patients diagnosed with arterial hypertension and from control group were histologically and molecularly examined.

RESULTS

The primary hypertensive and control groups did not differ in Na+ ​concentrations in the skin. However, the patients with hypertension and higher skin Na+ concentration had significantly greater density of skin lymphatic vessels. Higher skin Na+concentration was associated with higher skin water content. In turn, skin water content correlated with factors associated with lymphangiogenesis, i.e. NFAT5, VEGF-C, and podoplanin (PDPN) mRNA expression in the skin. The strong mutual pairwise correlations of the expressions of NFAT5, VEGF-C, vascular endothelial growth factor D (VEGF-D) and PDPN mRNA were noted in the skin in all of the studied groups.

CONCLUSIONS

Our study confirms that skin interstitium and the lymphatic system may be important players in the pathophysiology of arterial hypertension in humans. Based on the results of our study and existing literature in this field, we propose the hypothetical model which might explain the phenomenon of salt-sensitivity.

What to Do if the qPCR Test for SARS-CoV-2 or Other Pathogen Lacks Endogenous Internal Control? A Simple Test on Housekeeping Genes

Some of the products for the molecular diagnosis of infections do not have an endogenous internal control, and this is necessary to ensure that the result is not a false negative. The aim of the project was to design a simple low-cost RT-qPCR test that can confirm the expression of basic metabolism proteins, thus confirming the quality of genetic material for molecular diagnostic tests. Two successful equivalent qPCR assays for the detection of the GADPH and ACTB genes were obtained. The course of standard curves is logarithmic, with a very high correlation coefficient R2 within the range of 0.9955-0.9956. The reaction yield was between 85.5 and 109.7%, and the detection limit (LOD) with 95% positive probability was estimated at 0.0057 ng/µL for GAPDH and 0.0036 ng/µL for ACTB. These tests are universal because they function on various types of samples (swabs, cytology, etc.) and can complement the diagnosis of SARS-CoV-2 and other pathogens, as well as potentially oncological diagnostics.

Creating crime scene 3D model with body wear camera footage

Aim

The aim of this study is to develop a methodology for creating 3D images of crime scenes based on footage from cameras used by emergency services. To accomplish this, a research experiment was conducted, which consisted of re-enactment of a crime scene and simulation of the actions of the emergency team. The experiment did not illustrate a real case. The scenario was developed and dedicated for the purpose of the research.

Material and methods

The research material of this study consists of footage recorded in digital video format. The footage shows the course of a re-enacted intervention of emergency services at the crime scene. The re-enactment, which was a research experiment, was arranged under conditions close to real ones. The 3D model of the scene was created in three stages: video analysis and 3D reconstruction of the spatial position of the camera; 3D modelling of the figure of the participant with reconstruction of the position similar to the one in the recording; and 3D scanning of the scene of the simulated crime, assembly of individual elements, and scaling to real dimensions.

Results

The result (a 3D model) was presented in the form of a set of images: horizontal projections, vertical sections, and isometric and perspective views of the model. Technical data of the research equipment as well as other relevant information was presented in tables and diagrams.

Conclusions

This study demonstrated that graphic data obtained unintentionally and through alternative recording sources may significantly complement the data collected in the course of routine medico-legal and forensic activities. The use of cameras during the actions of rescue and emergency services allows us to obtain information of significant importance for medico-legal and forensic analyses. The footage from cameras of emergency services makes it possible to obtain a 3D image of the crime scene for further medico-legal and forensic analyses.

Molecular Diagnostic Tools against SARS-CoV-2 in Poland in 2022

The most effective way to stop the spread of COVID-19 (coronavirus disease 2019) is to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and isolate those infected as soon as possible. More than 1000 types of molecular and antigen-based immunoassay tests to detect SARS-CoV-2 are now commercially available worldwide. In this review, we present the possibilities of molecular diagnostics available in Poland in 2022. We provide a description of what samples have proven useful to confirm SARS-CoV-2 infection, we describe what methods are used, as well as what safeguards can and should be used to prevent false-negative and false-positive results, and finally we review the products that diagnostic laboratories have to choose from. We also describe diagnostic problems associated with the mutation of the virus.

Alcoholic Liver Disease Is Associated with Elevated Plasma Levels of Novel Advanced Glycation End-Products: A Preliminary Study

Elucidating the biochemical mechanisms associated with the progression of alcoholic liver disease (ALD) to more advanced stages such as alcoholic hepatitis (AH) remains an important clinical and scientific challenge. Several hypotheses point to the involvement of advanced glycation end-products (AGEs) in alcohol-associated liver injuries. Recently, we determined the structure of a synthetic, melibiose-derived AGE (MAGE), which was an analog of the novel AGE subgroup AGE10. The primary objective of our study was to determine whether AGE10 was associated with alcoholic hepatitis. The secondary objective was to provide a diagnostic accuracy of AGE10 in AH. To achieve this objective, we examined the plasma levels of AGE10 in 65 healthy individuals and 65 patients with AH. The AGE10 level was measured using a competitive ELISA. Our study confirmed that patients with AH had significantly higher plasma concentrations of AGE10 compared with healthy controls (184.5 ± 71.1 μg/mL and 123.5 ± 44.9 μg/mL, respectively; p < 0.001). In addition, AGE10 showed an acceptable performance as a diagnostic marker of AH, with an AUC of 0.78. In conclusion, AH was associated with elevated levels of novel advanced glycation end-product AGE10.

How Diabetes and Other Comorbidities of Elderly Patients and Their Treatment Influence Levels of Glycation Products

Medical care for geriatric patients is a great challenge, mainly due to various overlapping deficits relevant to numerous coexisting diseases, of which the most common are diabetes mellitus and atherosclerosis. In the case of diabetes, the glycation process is intensified, which accelerates atherosclerosis development and diabetic complications. Our goal was to investigate the relationship between the classical biochemical parameters of diabetes and atherosclerosis, as well as parameters which may indicate a nephropathy, and the parameters strictly related to glycation, taking into account the pharmacological treatment of patients. Methods: We analyzed the patients’ serum concentrations of fluorescent glycation product—pentosidine, concentrations of soluble receptors for advanced glycation products (sRAGE), lipoprotein receptor-1 (LOX-1), galectin 3 (GAL3), scavenger receptor class A (SR-A), and scavenger receptor class B (SR-BI), as well as the level of lipid peroxidation and free amine content. Among the identified correlations, the most interesting are the following: sRAGE with triglycerides (r = 0.47, p = 0.009), sRAGE with SR-BI (r = 0.47, p = 0.013), SR-BI with LOX-1 (r = 0.31, p = 0.013), and SR-BI with HDL (r = −0.30, p = 0.02). It has been shown that pentosidine and reactive free amine contents are significantly higher in elderly patients with ischemic heart disease. Pentosidine is also significantly higher in patients with arterial hypertension. Malondialdehyde turned out to be higher in patients with diabetes mellitus type 2 that was not treated with insulin or metformin than in those treated with both medications (p = 0.052). GAL3 was found to be lower both in persons without diabetes and in diabetics treated with metformin (p = 0.005). LOX-1 was higher in diabetic patients not treated with metformin or insulin, and lowest in diabetics treated with both insulin and metformin, with the effect of metformin reducing LOX-1 levels (p = 0.039). Our results were the basis for a discussion about the diagnostic value in the clinical practice of LOX-1 and GAL3 in geriatric patients with diabetes and also provide grounds for inferring the therapeutic benefits of insulin and metformin treatment.

Consequences of COVID-19 for the Pancreas

Although coronavirus disease 2019 (COVID-19)-related major health consequences involve the lungs, a growing body of evidence indicates that COVID-19 is not inert to the pancreas either. This review presents a summary of the molecular mechanisms involved in the development of pancreatic dysfunction during the course of COVID-19, the comparison of the effects of non-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on pancreatic function, and a summary of how drugs used in COVID-19 treatment may affect this organ. It appears that diabetes is not only a condition that predisposes a patient to suffer from more severe COVID-19, but it may also develop as a consequence of infection with this virus. Some SARS-CoV-2 inpatients experience acute pancreatitis due to direct infection of the tissue with the virus or due to systemic multiple organ dysfunction syndrome (MODS) accompanied by elevated levels of amylase and lipase. There are also reports that reveal a relationship between the development and treatment of pancreatic cancer and SARS-CoV-2 infection. It has been postulated that evaluation of pancreatic function should be increased in post-COVID-19 patients, both adults and children.

The Study of the Aorta Metallomics in the Context of Atherosclerosis

Atherosclerosis is a multifactorial disease, for which the etiology is so complex that we are currently unable to prevent it and effectively lower the statistics on mortality from cardiovascular diseases. Parallel to modern analyses in molecular biology and biochemistry, we want to carry out analyses at the level of micro- and macroelements in order to discover the interdependencies between elements during atherogenesis. In this work, we used the Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) to determine the content of calcium, magnesium, iron, copper, chromium, zinc, manganese, cadmium, lead, and zinc in the aorta sections of people who died a sudden death. We also estimated the content of metalloenzymes MMP-9, NOS-3, and SOD-2 using the immunohistochemical method. It was observed that with the age of the patient, the calcium content of the artery increased, while the content of copper and iron decreased. Very high correlations (correlation coefficient above 0.8) were observed for pairs of parameters in women: Mn–Ca, Fe–Cu, and Ca–Cd, and in men: Mn–Zn. The degree of atherosclerosis negatively correlated with magnesium and with cadmium. Chromium inhibited absorption of essential trace elements such as Cu and Fe due to its content being above the quantification threshold only if Cu and Fe were lower. Moreover, we discussed how to design research for the future in order to learn more about the pathomechanism of atherosclerosis and the effect of taking dietary supplements on the prevalence of cardiovascular diseases.

Advanced glycation end products and their receptors in serum of patients with type 2 diabetes

Glycation is a non-enzymatic process involving the reaction of reducing sugars or reactive oxoaldehyde with proteins, lipids or nucleic acids, which results in the formation of advanced glycation end products (AGEs). The presented work discusses the glycation process in people with advanced stage of type 1 or type 2 diabetes. The concentration of different AGEs and their receptors for 58 serum samples was determined by ELISA and by spectrofluorimetric methods. In addition to fluorescent low molecular weight and protein-bound AGEs, we have also marked a new class of AGEs: melibiose-derived glycation product (MAGE). Our attention was also focused on the two groups of AGEs receptors: scavenger receptors (SR-A and SR-B) and RAGE. The correlation between the SR-AI scavenging receptors concentration and the fluorescence of AGEs as well as diabetes biological markers: GFR, creatinine contentration and HbA1c was demonstrated. A relationship between the concentration of AGEs and their receptors was also found in serum sample of patients treated with the metformin and aspirin. Furthermore, the concentration of SR-AI scavenger and the fluorescence of total AGEs was significantly lower in treated patients than in non treated patients. AGEs have also been found to contribute to the development of cardiovascular disease, atherosclerosis and diabetic complications, what could be deduced from the correlation of AGEs level and HDL cholesterol or uric acid level. Thus, it was confirmed that AGEs are involved in the pathomechanism of diabetes and other degenerative diseases. Nowadays, it is believed that AGEs due to the long time remaining in the body may be an important diagnostic marker. Their determination may allow monitoring the progression of the disease and the effectiveness of the therapy.

Toxicity of advanced glycation end products (Review)

Advanced glycation end-products (AGEs) are proteins or lipids glycated nonenzymatically by glucose, or other reducing sugars and their derivatives, such as glyceraldehyde, glycolaldehyde, methyloglyoxal and acetaldehyde. There are three different means of AGE formation: i) Maillard reactions, the polyol pathway and lipid peroxidation. AGEs participate in the pathological mechanisms underlying the development of several diseases, such as diabetes and its complications, retinopathy or neuropathy, neurological disorders (for example, Parkinson's disease and Alzheimer's disease), atherosclerosis, hypertension and several types of cancer. AGE levels are increased in patients with hyperglycaemia, and is likely the result of the high concentration of glycation substrates circulating in the blood. The present review summarises the formation and nomenclature of advanced glycation end-products, with an emphasis on the role of AGEs in the development of diabetes, neurological disorders, as well as in cancer and other pathologies. A particular focus is placed on the functions of toxic AGEs. Additionally, studies which have shown the cytotoxicity of glycated albumin and other AGEs are also discussed. Finally, the diagnostic relevance of AGEs as well as for targeting in therapeutic strategies are highlighted.

What Every Diabetologist Should Know about SARS-CoV-2: State of Knowledge at the Beginning of 2021

For almost a year, the major medical problem has been the pandemic caused by the SARS-CoV-2 virus. People with diabetes who contract COVID-19 are likely to experience more serious symptoms than patients without diabetes. This article presents new research about the epidemiology of COVID-19 in a group of patients with diabetes. It details the mortality and prognosis in such patients, as well as the relationship between COVID-19 and the diseases most often coexisting with diabetes: obesity, atherosclerosis, hypertension, and increased risk for infection. It also details how the virus infects and affects patients with hyperglycemia. The context of glycation and receptors for advanced glycation products (RAGE) seems to be of particular importance here. We also present a hypothesis related to the cause-and-effect axis-it turns out that diabetes can be both the cause of the more difficult course of COVID-19 and the result of SARS-CoV-2 infection. The last part of this article discusses the impact of antihyperglycemic drugs on the development of COVID-19 and other pharmacological implications, including which non-classical antihyperglycemic drugs seem to be effective in both the treatment of coronavirus infection and glucose homeostasis, and what strategies related to RAGE and glycation should be considered.

Relationship between calcification, atherosclerosis and matrix proteins in the human aorta

INTRODUCTION

Extracellular matrix (ECM) proteins have been associated with atherosclerotic complications, such as plaque rupture, calcification and aneurysm. It is not clear what role different types of collagen play in the pathomechanism of atherosclerosis. The aim of the study was to analyze the content of elastin and major types of collagen in the aortic wall and how they associated are with course of atherosclerosis.

MATERIAL AND METHODS

In this work we present six biochemical parameters related to ECM proteins and collagen-specific amino acids (collagen type I, III, and IV, elastin, proline and hydroxyproline) analyzed in 106 patients' aortic wall specimens characterized by different degree of atherosclerosis. Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC/ESI-MS/MS), ELISA and immunohistochemical methods were used. The severity of atherosclerosis was assessed on the six-point scale of the American Heart Association, taking into account the number and location of foam cells, the presence of a fatty core, calcium deposits and other characteristic atherosclerotic features.

RESULTS

The results show that there is a relationship between the content of collagen-specific amino acids and development of atherosclerosis. The degree of atherosclerotic lesions was negatively correlated with the content of proline, hydroxyproline and the ratio of these two amino acids. Calcium deposits and surrounding tissue were compared and it was demonstrated that the ratio of type I collagen to type III collagen was higher in the aortic tissue than in aortic calcification areas, while the ratio of collagen type III to elastin was smaller in the artery than in the calcium deposits.

CONCLUSIONS

We suggest that increase in collagen type III presence in the calcification matrix may stem from disorders in the structure of the type I and III collagen fibers. These anomalous fibers are likely to favor accumulation of the calcium salts, an important feature of the process of atheromatosis.

Advanced glycation end products derived from serum albumin modification by glucose (AGE-1) reflect clustering of lipid-associated metabolic abnormalities and are decreased in patients treated with acarbose: A cross-sectional study

BACKGROUND

Advanced glycation end products (AGEs) are formed during protein modification by a reduction of sugars or reactive aldehydes. Depending on the pathology, various AGEs may be formed. They are stable compounds and are considered as potential diseases markers.

OBJECTIVES

The objective of this study was to assess glucose-mediated albumin modification that yields non-standard epitopes of AGEs (AGE-1) in diabetes and in associated metabolic abnormalities.

MATERIAL AND METHODS

The AGE-1, expressed as median AGE-1 level and AGE-1 positivity, was determined in 246 individuals (198 with prediabetes/diabetes) using a new slot-dot-blot method (allowing for detection of barely traceable analytes) and related to the presence of diabetes-associated metabolic abnormalities and complications, and treatment.

RESULTS

The AGE-1 level was higher in patients with prediabetes/diabetes than in controls. Its elevation was associated with metabolic syndrome (MetS), obesity, hyperlipidemia, and non-alcoholic fatty liver disease (NAFLD) but not with diabetic control or microand macroangiopathy, except for atherosclerotic plaques formation in carotid arteries. The AGE-1-positive patients had higher triglycerides and lower high-density lipoprotein (HDL)-cholesterol. In patients untreated with aspirin, AGE-1 positivity was associated with higher C-reactive protein (CRP) level. Treatment with aspirin, sulfonylureas and gliptins was associated with higher AGE-1 level and with dyslipidemia medications with higher AGE-1 positivity. In patients with abnormal glucose metabolism, acarbose treatment was associated with lower AGE-1 positivity. Multivariate analysis showed MetS, carotid artery plaques, NAFLD, and treatment with aspirin and acarbose to be independently associated with AGE-1 positivity.

CONCLUSIONS

Unlike standard AGEs, AGE-1 is more tightly associated with abnormalities in lipid than glucose metabolism, and lower in patients treated with acarbose but not with other antidiabetics.

Non-standard AGE4 epitopes that predict polyneuropathy independently of obesity can be detected by slot dot-blot immunoassay

BACKGROUND

Advanced glycation end-products (AGEs) are formed during cascade reactions between reducing sugars or reactive aldehydes and proteins, lipids or DNA molecules. They constitute a group of various stable compounds. Advanced glycation end-products are considered potential biomarkers of metabolic disorders. However, so far only a few methods to determine the level of individual AGEs have been developed.

OBJECTIVES

The aim of the study was to compare the efficiency of the slot-dot blot method and direct enzyme-linked immunosorbent assay (ELISA) in detecting non-standard epitopes of methylglyoxal (MGO)-modified proteins (AGE4) found in diabetes serum in trace amounts, and to assess AGE4 in diabetes and associated metabolic abnormalities.

MATERIAL AND METHODS

The presence of AGE4 was detected using 2 methods: direct ELISA and the slot-dot blot method - a newly developed immunoassay based on monoclonal, commercially available antibody detection of non-standard AGE epitopes. AGE4 quantification, expressed as median AGE4 in arbitrary units (AU) and AGE4 positivity (the percent of samples with detectable AGE4) was related to diabetes-associated metabolic abnormalities, complications and treatment.

RESULTS

Slot-dot blot was significantly more efficient than ELISA in detecting non-standard AGE4 epitopes. AGE4 positivity was less frequent in patients with microangiopathy and in those with polyneuropathy. In patients with abnormal glucose metabolism, metformin treatment was associated with higher AGE4. AGE4 positivity was significantly lower in gliptin-treated patients. Multivariate analysis showed that polyneuropathy and obesity were independently associated with AGE4 positivity, with odds ratios (ORs) of 0.21 and 3.02, respectively. Moreover, logistic regression showed that AGE4 positivity and HbA1c are independent predictors of polyneuropathy. Considering both indicators allows correct classification of 70.4% of cases with a general accuracy of 76%.

CONCLUSIONS

The slot dot-blot method detects compounds found in serum in trace amounts. Accumulation of AGE4 was associated with glucose metabolism abnormalities. A tendency toward AGE4 positivity was less frequent in patients with microangiopathy and in non-treated and gliptin-treated diabetes patients.

Protrusive and retractive structures formed during cell migration

Cell migration is essential to many physiological processes; however, it is also a cause of cancer metastasis formation and other pathological phenomena. Due to structural and functional variety of cells, a variety of structures formed by the cell membrane, which are designed to initiate or maintain cell movement, are observed. The work describes 12 such structures: lamellipodium, lamellum, filopodium, microspikes, blebs, lobopodium, invadopodium, podosomes, dorsal and peripheral ruffles, pseudopodium and uropodium. We described a characteristics of the structure, mechanism of its formation and occurrence. The key structural protein of almost all of these structures is actin, its polymerization pushes the cell membrane in the direction of movement. Formation of a specific protrusion depends on the actin binding proteins which regulate the process of G actin association to the filaments. For example, Arp2/3 determines the formation of branched filaments, which results in the formation of wide, flat lamellipodium, and fascin enables the formation of long bundles, which results in filopodia formation. On the other hand, there is also an actin-independent way of movement, called amoeboid, in which myosin plays a central role and on the cell surface appear vesicular structures called blebs. Some structures are associated with proteolytic activity, particularly invadopodia and podosomes, through which the cells can degrade extracellular matrix and penetrate deeper into the tissues. These structures not only allow the extension of the cell body to enable migration, but they can also be involved in the environment perception, serve as mechanosensors and interact with other cells. The control of the formation of protrusive structures is of great importance in oncology, immunology and cardiovascular medicine.

Advanced glycation end products as a source of artifacts in immunoenzymatic methods

The most abundant proteins in the arteries are those of extracellular matrix, ie. collagen and elastin. Due to their long half-lifes these proteins have an increased chance to undergo glycation. The aim of this study was to determine relationship between the content of the main extracellular matrix proteins and the advanced glycation end products (AGEs) in arteries. In this study 103 fragments of aorta were analyzed by ELISA and immunobloting for the content of collagens type I, III and IV and elastin and the content of advanced glycation end-products (AGE). A negative correlation between the content of collagens type III and IV and AGE (r = -0,258, p = 0,0122, and a weak negative correlation between collagen type III and age of the sample donor (r = 0,218, p = 0,0262) were demonstrated. This result comes as a surprise and it contradicts an intuitive assumption that with more glycation substrate, i.e. matrix proteins, more AGE products are expected. We have concluded that the results of the ELISA tests must have been influenced by the glycation. As a consequence, either modified protein molecules were not being recognized by the antibodies, or the glycation, and formation of crosslinks have blocked access of the antibodies to the antigen. It will conceal the effect of the linear dependence between the result (absorbance/densitometry) from the quantity of protein to which the antibody is directed.

Glycation of Matrix Proteins in the Artery Inhibits Migration of Smooth Muscle Cells from the Media to the Intima

Formation and growth of atherosclerotic plaques have serious clinical consequences. One mechanism that occurs during atherogenesis is migration of smooth muscle cells from the middle layer of the artery to the intima, where they proliferate and are transformed into foam cells. This degenerative process is accompanied by glycation, by which proteins are modified and change the biomechanical and biochemical properties. The aim of the study was to determine whether glycation of collagen and elastin building the walls of blood vessels alters the adhesion and rate of myocyte migration. In vitro experiments included migration assays and immunocytochemical staining with anti α-actin, β-catenin anti-collagen type IV antibodies. It turns out that there is a tendency to decrease the number of cells that had migrated through the barrier consisting of glycated proteins as compared to the control. Adversely, the morphology of the cells cultured in the presence of glycated substrates is changed. The lower intensity of β-catenin staining indicates lower adhesiveness of such cells. It is proposed that glycation inhibits migration of smooth muscle cells from the media to the intima, which represents part of the anti-atherogenic mechanism.

Thymosin β as an Actin-binding Protein with a Variety of Functions

According to current data, the thymosin β family is composed of 20 short (40-44 amino acid) peptides, but in a healthy human body only 2 are expressed - thymosin β4 and β10. Their most characteristic feature is the ability to form a complex with monomeric actin, thereby preventing polymerization into a filamentous form, hence the name Actin-Binding Protein (ABP). These peptides play numerous different functions. Among others, they affect the processes of carcinogenesis, differentiation and angiogenesis, influence metalloproteinase activity and accelerate wound healing. Moreover, significant biological activity has also been displayed by Tβ4 derived peptides: Ac-SDKP, the N-terminal fragment which is involved, inter alia, in stimulating angiogenesis and the inhibition of stem cell proliferation and Tβ4 sulfoxide, an oxidation product of one of the peptide methionine by hydrogen peroxide, which inhibit the development of inflammation. The properties of these peptides have potential applications in cardiovascular medicine, dermatology, ophthalmology and other medical areas.

An Estimation of the Biological Properties of Fish Collagen in an Experimental In Vitro Study

BACKGROUND

The principal sources of medical collagen are pork, calf skin and bone. There are now more studies on a much safer, alternative source of active collagen, mainly from aquatic life. Active collagen and its peptides FCP (fish collagen peptides) have already been extracted from the skin of salmon, cobia, hoki, tilapia, zebrafish, ling, shark, silver carp and also jellyfish.

OBJECTIVES

The aim of the study is to evaluate the effect of fish collagen on human fibroblasts from gingiva. The cytotoxicity of the new formulation and induction of endogenous collagen was estimated by means of the collagen derived from fish skin.

MATERIAL AND METHODS

Fish collagen was extracted from the skin of silver carp at 16 degrees Celsius. To compare the biocompatibility and endogenous collagen production Geistlich Bio-Gide® membrane was ordered in Geistlich Biomaterials (Geistich AG, Wolhusen, Switzerland). The culture of human fibroblasts was performed acc. to Saczko et al. The fibroblasts were treated 96 hours with 1.0%, 0.5% and 0.1% experimental collagen formulation to induce endogenous collagen production. The Sircol collagen assay was done to measure amount of collagen. Cell viability was assessed by measuring mitochondrial activity in MTT assay after 24 h followed by 24 h of incubation with experimental collagen formulation. Qualitative analysis was performed by immunocytochemically staining of collagen type I and III.

RESULTS

Preparations of fish collagen are not cytotoxic at concentrations below 1%. Cells cultured in the presence of this product are characterized by a large number of endogenous collagen, which is comparable to the control. In case of porcine collagen membrane was noticed decreased to 83% production of endogenous collagen and reduction of cell viability to 69%.

CONCLUSIONS

Our study showed that experimental fish collagen is an innovative product which may induce expression of endogenous collagen in fibroblasts.

[Metabolism of collagen and its role in arteriosclerosis]

Collagen is one of main structural protein in organism. It plays a fundamental role in a lot of functions crucial for proper functioning connective tissue. The metabolism of the protein-production, modification and degradation should be balanced, in other situation appear serious health consequences, inter alia course of the arteriosclerosis, which is one of the most serious contemporary medical problem in developed countries, might be deteriorated. The collagen is crucial for the atherosclerotic plaque stability, if there is the deficiency of it, the blood vessels are more prone to rupture. On the other hand, accumulation of the protein leads to the arterial stenosis. It is suggested that collagen is involved in the calcification of atherosclerotic areas of the arteries, in binding of low density lipoproteins, stimulation of migration and apoptosis of arterial smooth muscle cells.

[Heterogeneity and functions of collagen in arteries]

Collagen is one of the most abundant proteins in the human organism. It is the major component of the extracellular matrix. The protein is represented by 29 distinct types, which differ in structure, amount, tissue distribution and affinity to the other elements of ECM. It is reported that collagen is responsible for the maintenance of integrity, tensile strength and elasticity of the connective tissue. The properties plays crucial role in functioning of the blood vessel walls. This work is focused on arteries. There are found 14 types of collagen. They are located mainly in the basement membrane and subendothelium. The vessels contain mostly fibrillar collagen (types I, III and V), also fibril associated (XII, XIV, XVI, XXI), microfibril (VI), basement membrane associated (IV, XV, XVIII, XIX), membrane bound (XIII) and anchoring (VII) collagen.