Autoimmune reaction against pancreatic beta cells in children and adolescents with simple obesity

IntroductionOne of the most important complications of obesity is insulin resistance, which leads to carbohydrate metabolism disorders such as type 2 diabetes. However, obesity is also associated with development of an autoimmune response against various organs, including pancreatic beta cells. The prevalence of such autoimmune processes in children and their possible contribution to the increased incidence of type 1 diabetes is currently unclear. Therefore, the present study assessed the prevalence of autoantibodies against pancreatic islet beta cell’s antigens in children and adolescents with simple obesity.Material and methodsThis prospective observational study included pediatric patients (up to 18 years of age) with simple obesity hospitalized between 2011 and 2016 at the Department of Pediatrics, Diabetology, Endocrinology and Nephrology of the Medical University of Lodz. Children with acute or chronic conditions that might additionally affect insulin resistance or glucose metabolism were excluded. Collected clinical data included sex, age, sexual maturity ratings (Tanner`s scale), body height and weight, waist and hip circumference, amount of body fat and lean body mass. Each participant underwent a 2-hour oral glucose tolerance test with simultaneous measurements of glycaemia and insulinemia at 0`, 60` and 120`. In addition, glycated hemoglobin HbA1c, fasting and stimulated c-peptide, total cholesterol, as well as high- and low-density cholesterol and triglycerides were measured. Insulin resistance was assessed by calculating HOMA-IR index. The following autoantibodies against pancreatic islet beta cells were determined in each child: ICA - antibodies against cytoplasmic antigens of pancreatic islets, GAD - antibodies against glutamic acid decarboxylase, ZnT8 - antibodies against zinc transporter, IA2 - antibodies against tyrosine phosphatase, IAA – antibodies against insulin.ResultsThe study group included 161 children (57.4% boys, mean age 13.1 ± 2.9 years) with simple obesity (mean BMI z-score +2.2 ± 1.6). Among them, 28 (17.4%) were diagnosed with impaired glucose metabolism during OGTT [23 (82.2%) – isolated impaired glucose tolerance (IGT), 3 (10.7%) – isolated impaired fasting glucose (IFG), 2 (7.1%) – IFG and IGT]. Of the children tested, 28 (17.4%) were tested positive for at least one islet-specific autoantibody [with similar percentages in boys (15, 17.4%) and girls (13, 17.3%), p=0.9855], with ICA being the most common (positive in 18, 11.2%), followed by IAA (7, 4.3%), ZnT8 (5, 3.1%), GADA (3, 1.9%) and IA2 (1, 0.6%). There was no association between the presence of the tested antibodies and age, sex, stage of puberty, parameters assessing the degree of obesity, HbA1c, lipid levels and basal metabolic rate. However, autoantibody-positive subjects were more likely to present IFG or IGT in OGTT compared to those who tested completely negative (9, 32.1% vs 19, 14.3%, p=0.0280). Their HOMA-IR was also significantly higher (HOMA-IR: 4.3 ± 1.9 vs 3.4 ± 1.9, p=0.0203) and this difference remained statistically significant after adjusting for sex and age (p=0.0340).ConclusionsChildren and adolescents with simple obesity presented a higher prevalence of markers of autoimmune response against pancreatic beta cells than the general population. Most often, they had only one type of antibody - ICA. The presence of autoimmune response indicators against pancreatic islet antigens is more common in obese patients with impaired carbohydrate metabolism and is associated with lower insulin sensitivity

Immune-cell BDNF expression in treatment-naïve relapsing-remitting multiple sclerosis patients and following one year of immunomodulation therapy

Although neurons are the main source of neurotrophins in the healthy brain, neurotrophins can also be expressed in the immune system. We have previously shown that in relapsing-remitting multiple sclerosis (RRMS) lower immune-cell neurotrophin levels are associated with brain atrophy and cognitive impairment. The aim of the present study was to assess if immune-cell neurotrophin expression is impaired in MS as compared with the healthy controls, and to describe if these levels change in treatment-naïve RRMS patients, following one year of immunomodulation. Fifty treatment-naïve RRMS patients were assessed at baseline and after one year of immunomodulation (beta-interferons/glatiramer acetate). The control group included 39 healthy subjects matched according to age and gender. Peripheral blood mononuclear cells (PBMCs) were isolated from heparinized blood using Ficoll-Histopaque gradient. The levels of brain-derived-neurotrophic-factor (BDNF), beta-nerve-growth-factor (beta-NGF), neurotrophin-3 (NT-3) and neurotrophin-4/5 (NT-4/5) were measured in PBMC lysates with ELISA. BDNF levels were significantly lower in MS than in the healthy controls (median 613 vs. 1657pg/mg protein, p<0.001). After one year of immunomodulation, BDNF expression did not change significantly (p=0.06) on the group level. In 70% of patients there was no increase in BDNF level, and in 30% it increased. We observed no differences between treatment groups. Other neurotrophins were detected in a minority of MS samples (as opposed to the controls). To conclude, we have shown that immune-cell production of neurotrophins is impaired in MS patients. In our MS cohort standard immunomodulation failed to restore normal BDNF levels in PBMCs within one year of therapy

Presence of homologues of the PVY resistance gene Rysto in wild relatives of potato

Poster presented at 12TH INTERNATIONAL CONGRESS OF PLANT PATHOLOGY ICPP2023, Lyon, France The research leading to these results has received funding from the Norwegian Financial Mechanism 2014-2021, project DivGene: UMO2019/34/H/NZ9/0055

PacBio amplicon sequencing of Rysto homologues in wild potato species

Poster presented at EAPR Pathology & Pests Section Meeting, Arras, France The research leading to these results has received funding from the Norwegian Financial Mechanism 2014-2021, project DivGene: UMO2019/34/H/NZ9/0055

Anti-interferon-beta antibodies in Polish multiple sclerosis patients: prevalence and clinical significance in a long-term prospective study

Aim of the study. To determine the prevalence of anti-interferon-β binding (BAb) and neutralising antibodies (NAb), and to investigate whether NAb measured by luciferase-based cell assay can predict treatment response in multiple sclerosis (MS) patients treated with interferon-β-1b (IFNβ-1b). Clinical rationale for the study. A subgroup of IFNβ-treated MS patients develop NAb directed against the drug. The clinical significance remains controversial, which could be explained to some extent by technical difficulties in NAb detection and quantification. A simple, specific and reproducible test for NAb might help elucidate these uncertainties. Materials and methods. Sera from 101 consecutive MS patients initiating treatment with IFNβ-1b were collected at baseline and during the first two years, and assessed for BAbNAb with a novel luciferase-based cell assay. Median clinical follow-up lasted 5.1 years. Results. BAb were present in 97% and NAb in 88% of the study cohort. Unexpectedly, 92% of patients tested positive for Bab and 12.5% for NAb at baseline, before drug exposure. Patients with baseline NAb positivity were more likely to remain free of disease activity in the first three years of treatment. When baseline-positive cases were grouped together with those who remained NAb-negative, and the resulting group was compared to those who became positive after drug exposure, NAb positivity was associated with a higher risk of disease activity during the entire follow-up. Direct comparison of BAb/Nab-positive and BAb/Nab-negative patients only revealed an association of BAb positivity with more active disease after four years of treatment, while NAb failed to predict the outcome. Conclusions and clinical implications. Antibodies developed after treatment initiation are associated with a worse outcome. Naturally- occurring antibodies appear to predict more benign disease. Their prevalence and specificity require further investigation

Utjecaj kronične istodobne izloženosti olovu, kadmiju i manganu na oksidativni stres u jetri i srcu štakora

The aim of this study was to assess the effects of chronic combined exposure to low, environmental doses of Cd, Pb, and Mn on oxidative stress in the liver and heart of rats and on their liver function parameters. Male Wistar rats were divided randomly into eight groups. For nine months controls were receiving drinking water alone, whereas the exposed groups were receiving drinking water with Pb (0.2 mg L-1), Cd (1 mg L-1), and Mn (2 mg L-1) alone or in combinations. Malondialdehyde (MDA) significantly increased in both heart and liver of the animals after combined exposure to metals. Heart MDA correlated with blood Cd, Pb, and Mn and liver MDA with blood Cd. Aspartate aminotransferase (AST) activity and bilirubin concentration also increased significantly in the animal group exposed to all three metals and correlated positively with blood Cd, Pb, and Mn. Our study has confirmed the synergistic effect of the Cd, Mn, and Pb combination on the increase in heart MDA. A similar synergy was observed for Pb+Mn in the increase of serum alanine aminotransferase (ALT) activity as an indicator of liver function.Cilj je ovog istraživanja bio ocijeniti učinke kronične izloženosti kombinaciji Cd, Pb i Mn u niskim dozama kakve su u okolišu na oksidativni stres u jetrima i srcu štakora te na pokazatelje jetrene funkcije. U tu smo svrhu mužjake Wistar štakora nasumce podijelili u osam skupina, od kojih je kontrolna pila čistu vodu, a izložene skupine vodu pomiješanu s olovom (0,2 mg L-1), kadmijem (1 mg L-1) i manganom (2 mg L-1), zasebno ili u kombinacijama. Koncentracija malondialdehida (MDA) značajno se povećala u oba organa životinja izloženih kombinacijama metala. Srčani MDA korelirao je s razinama kadmija, olova i mangana u krvi, a jetreni MDA s razinom kadmija u krvi. Aktivnost aspartat aminotransferaza (AST) i koncentracije bilirubina također su bile značajno povišene u skupini izloženoj svim trima metalima te su korelirale s razinama kadmija, olova i mangana u krvi. Rezultati istraživanja potvrdili su da zajedno ova tri metala djeluju na povećanje MDA u srcu. Slična je sinergija zamijećena i između olova i mangana s obzirom na povećanje razine alanin aminotransferaze (ALT) u serumu, koji je pokazatelj jetrene funkcije

Comprehensive linker-scanning mutagenesis of the hepatitis C virus E1 and E2 envelope glycoproteins reveals new structure–function relationships

Despite extensive research, many details about the structure and functions of hepatitis C virus (HCV) glycoproteins E1 and E2 are not fully understood, and their crystal structure remains to be determined. We applied linker-scanning mutagenesis to generate a panel of 34 mutants, each containing an insertion of 5 aa at a random position within the E1E2 sequence. The mutated glycoproteins were analysed by using a range of assays to identify regions critical for maintaining protein conformation, E1E2 complex assembly, CD81 receptor binding, membrane fusion and infectivity. The results, while supporting previously published data, provide several interesting new findings. Firstly, insertion at amino acid 587 or 596 reduced E1E2 heterodimerization without affecting reactivity with some conformation-sensitive mAbs or with CD81, thus implicating these residues in glycoprotein assembly. Secondly, insertions within a conserved region of E2, between amino acid residues 611 and 631, severely disrupted protein conformation and abrogated binding of all conformation-sensitive antibodies, suggesting that the structural integrity of this region is critical for the correct folding of E2. Thirdly, an insertion at Leu-682 specifically affected membrane fusion, providing direct evidence that the membrane-proximal ‘stem’ of E2 is involved in the fusion mechanism. Overall, our results show that the HCV glycoproteins generally do not tolerate insertions and that there are a very limited number of sites that can be changed without dramatic loss of function. Nevertheless, we identified two E2 insertion mutants, at amino acid residues 408 and 577, that were infectious in the murine leukemia virus-based HCV pseudoparticle system