👤 Andrzej Pawlik

Endosomal system dysfunction within neurons is a prominent early feature of Alzheimer's disease (AD) pathology. Multiple AD risk factors are regulators of endocytosis and known to cause hyperactivity of the early endosome small GTPase rab5, resulting in neuronal endosomal pathway disruption and cholinergic neurodegeneration. Adaptor protein containing Pleckstrin homology domain, Phosphotyrosine binding domain, Leucine zipper motif (APPL1), an important rab5 effector protein and signaling molecule has been shown in vitro to interface between endosomal and neuronal dysfunction through a rab5-activating interaction with the BACE1-generated C-terminal fragment of amyloid precursor protein (APP-βCTF), a pathogenic APP fragment generated within endosomal compartments. To understand the contribution of APPL1 to AD-related endosomal dysfunction in vivo, we generated a transgenic mouse model overexpressing human APPL1 within neurons (Thy1-APPL1). Strongly supporting the important endosomal regulatory roles of APPL1 and their relevance to AD etiology, Thy1-APPL1 mice (both sexes) develop enlarged neuronal early endosomes and increased synaptic endocytosis due to increased rab5 activation. We demonstrated pathophysiological consequences of APPL1 overexpression, including functional changes in hippocampal long-term potentiation (LTP) and long-term depression (LTD), degeneration of large projection cholinergic neurons of the basal forebrain, and impaired hippocampal-dependent memory. Our evidence shows that neuronal APPL1 elevation modeling its functional increase in the AD brain induces a cascade of AD-related pathological effects within neurons, including early endosome anomalies, synaptic dysfunction, and selective neurodegeneration. Our in vivo model highlights the contributions of APPL1 to the pathobiology and neuronal consequences of early endosomal pathway disruption and its potential value as a therapeutic target. Show less

Endosomal system dysfunction within neurons is a prominent early feature of Alzheimer's disease (AD) pathology. Multiple AD risk factors are regulators of endocytosis and are known to cause hyper-activity of the early-endosome small GTPase rab5, resulting in neuronal endosomal pathway disruption and cholinergic neurodegeneration. Adaptor protein containing Pleckstrin homology domain, Phosphotyrosine binding domain, Leucine zipper motif (APPL1), an important rab5 effector protein and signaling molecule, has been shown Neuronal endosome dysfunction appears early in Alzheimer's disease (AD) and is linked to memory loss. Genes and risk factors associated with AD often increase rab5 activity, a protein that disrupts endosomal signalling when hyperactivated. APPL1, a key rab5 partner, worsens this dysfunction via its interaction with APP-βCTF, a protein fragment associated with AD. To explore APPL1's role, we created a genetically modified mouse that overexpresses APPL1 in neurons. This model provides the first Show less

Coronary artery disease is caused by changes in the coronary arteries due to the atherosclerotic process and thrombotic changes. A very important role in the development of the atherosclerotic process in the coronary vessels is played by the inflammatory process and the immune response. Due to the important role of lipids and the coagulation process in the atherosclerotic process, research has also focused on genes affecting lipid metabolism and the coagulation system. Lipoprotein lipase (LPL) is an enzyme that metabolises lipids, hydrolysing triglycerides to produce free fatty acids and glycerol. Protein C (PC) is an essential component of coagulation and fibrinolysis. It is activated on the endothelial surface by the membrane-bound thrombin-thrombomodulin complex. Platelet-derived growth factor (PDGF) has a number of important functions in processes related to fibroblast and smooth muscle cell function. Due to their influence on lipid metabolism and coagulation processes, LPL, PROCR (endothelial cell protein C receptor) and PDGF may affect the atherosclerotic process and, thus, the risk of coronary heart disease. The aim of the study was to examine the associations between the The study included 232 patients with unstable angina and 144 healthy subjects as the control group. Genotyping was performed using real-time PCR. There were no statistically significant differences in the distribution of the polymorphisms tested between the patients with unstable angina and the control subjects. The results showed associations between the The results of our study did not show that the Show less

Coronary artery disease (CAD) is a syndrome resulting from myocardial ischaemia of heterogeneous pathomechanism. Environmental and genetic factors contribute to its development. Atherosclerotic plaques that significantly narrow the lumen of coronary arteries cause symptoms of myocardial ischaemia. Acute coronary incidents are most often associated with plaque rupture or erosion accompanied by local activation of the coagulation system with thrombus formation. Plaque formation and stability are influenced by endothelial function and vascular smooth muscle cell function. In this study, we investigated the association between polymorphisms in genes affecting endothelial and vascular smooth muscle cell (VSMC) function and the occurrence of unstable angina pectoris. The aim of this study was to evaluate the association between the Show less

Gestational diabetes mellitus (GDM) is a metabolic disorder in pregnant women leading to various complications. Consequently, factors predisposing its development are being sought. Previous studies have shown that the pathogenesis of GDM is similar to that of type 2 diabetes, and it is therefore thought that the two diseases may have a common genetic basis. The aim of this study was to examine the associations between thyroid adenoma-associated ( Show less

Coronary artery disease (CAD) is a significant public health problem because it is one of the major causes of death worldwide. Several studies have investigated the associations between CAD and polymorphisms in genes connected with platelet aggregation and the risk of venous thromboembolism. In this study, we examined the associations between polymorphisms in There were no significant differences in the distribution of the studied polymorphisms between the patients with unstable angina and the controls. In patients with the The results of this study suggest a lack of association between Show less

Gestational diabetes mellitus (GDM) is a carbohydrate intolerance that occurs in women during pregnancy. The aims of this study were to develop a model to predict the risk of GDM development using common clinical parameters and selected genetic polymorphisms and to analyse the performance of the model using receiver operator characteristic (ROC) curves. ROC analysis was used to examine whether the evaluation of genetic polymorphisms may enhance the accuracy of GDM prediction in comparison to using common clinical risk factors only. This study included 204 pregnant women with GDM and 207 pregnant women with normal glucose tolerance. The diagnosis of GDM was based on a 75 g oral glucose tolerance test at 24-28 weeks gestation. The difference between the AUC of ROC curves for the model 1 including only age and BMI and the model 2 also including 8 genetic polymorphisms was highly significant (p=0.0001) in favour of model 2 (0.090±0.023). Moreover, the additional use of 8 genetic polymorphisms may increase both the sensitivity and specificity of GDM prediction by 10%. The results of this study indicate that the use of 8 genetic polymorphisms associated with carbohydrate and lipid metabolism and type 2 diabetes [ Show less

Gestational diabetes mellitus (GDM) is the carbohydrate intolerance that can occur in pregnancy. Genetic polymorphisms associated with type 2 diabetes could be considered as genetic determinants of GDM. The aim of this study was to examine the association between GCK, GCKR, FADS1, DGKB/TMEM195 and CDKAL1 gene polymorphisms and the development of gestational diabetes. These genetic polymorphisms are involved in glucose and lipid metabolism and are associated with increased risk for diabetes type 2. This case-control study included 204 pregnant women with GDM and 207 pregnant women with normal glucose tolerance. The diagnosis of GDM was based on a 75-gram oral glucose tolerance test at 24 to 28 weeks' gestation. There was a statistically significant association between FADS1 rs174550 gene polymorphism and GDM. Among women with GDM, a predominance of C-allele carriers (CC and TC genotypes) was observed (CC+TC vs. TT; p=0.00065; OR=1.97, 95% CI, 1.33 to 2.92), and this association remained significant after correction for multiple testing. In the case of the GCK rs1799884 polymorphism, there was a predominance of the T allele in women with GDM; however, this association reached only borderline statistical significance (p=0.08). Women with higher numbers of GCK rs1799884 T alleles more commonly required insulin treatment; likewise, the CDKAL1 rs10946398 CC genotype was associated with the need for insulin therapy. However, these associations do not pass the statistical significance threshold after correction for multiple testing. The results of our study suggest an association between the rs174550 FADS1 polymorphism and GDM risk. Show less