Polygenic Type Research Articles

The neurotrophic factor artemin and its receptor GFRα3 mediate migraine-like pain via the ion channel TRPM8.

Migraine has a strong genetic foundation, including both monogenic and polygenic types. The former are rare, with most migraine considered polygenic, supported by genome-wide association studies (GWAS) identifying numerous genetic variants linked with migraine risk. Surprisingly, some of the most common mutations are associated with transient receptor potential melastatin 8 (TRPM8), a non-selective cation channel that is the primary sensor of cold temperatures in cutaneous primary afferents of the somatosensory system. However, it is unlikely that the temperature sensitivity of TRPM8 is relevant in migraine-related tissues, such as the meninges, suggesting other activation mechanisms underly its role in migraine pathogenesis. Thus, to define the basis of the channel's involvement, we reasoned that cellular processes that increase cold sensitivity in the skin, such as the neurotrophic factor artemin, via its receptor glial cell-line derived neurotrophic factor family receptor alpha-3 (GFRα3), also mediate TRPM8-associated migraine-like pain in the meninges. To investigate the role of artemin and GFRα3 in preclinical rodent migraine models, we infused nitroglycerin acutely and chronically, and measured changes in periorbital and hind paw mechanical sensitivity in male and female mice lacking GFRα3, after neutralization of free artemin with specific monoclonal antibodies, or by systemic treatment with a TRPM8-specific antagonist. Further, in mice lacking GFRα3 we tested the effects of supradural infusions of a mix of inflammatory mediators, as well as tested if dura stimulation with artemin or a TRPM8-specific agonist induce migraine-related pain in mice. We find that mechanical allodynia induced by systemic nitroglycerin, or supradural infusion of inflammatory mediators, involves GFRα3. In addition, neutralization of circulating artemin reduces the nitroglycerin phenotype, demonstrating the importance of this neurotrophic pathway in headaches. Further, we show TRPM8 expression in the meninges, and that direct supradural infusion of either a TRPM8-specific agonist or artemin itself produces mechanical allodynia, with the latter dependent on TRPM8 and ameliorated by concurrent treatment with sumatriptan. These results indicate that neuroinflammatory events in the meninges can produce migraine-like pain in mice via artemin and GFRα3, likely acting upstream of TRPM8, providing a novel pathway that may contribute to headaches or migraine pathogenesis.

The neurotrophic factor artemin and its receptor GFRα3 mediate migraine-like pain via the ion channel TRPM8.

Migraine has a strong genetic foundation, including both monogenic and polygenic types. The former are rare, with most migraine considered polygenic, supported by genome-wide association studies (GWAS) identifying numerous genetic variants associated with migraine risk. Surprisingly, some of the most common mutations are associated with TRPM8, a non-selective cation channel that is the primary sensor of cold temperatures in primary afferent neurons of the somatosensory system. However, it is unlikely that the temperature sensitivity of TRPM8 underlies its role in migraine pathogenesis. To define the basis of the channel's involvement, we reasoned that cellular processes that increase cold sensitivity in the skin, such as the neurotrophic factor artemin, via its receptor GFRα3, also mediate TRPM8-associated migraine-like pain in the meninges. To investigate the role of artemin and GFRα3 in preclinical rodent migraine models, we infused nitroglycerin acutely and chronically, and measured changes in periorbital and hind paw mechanical sensitivity in male and female mice lacking GFRα3, after neutralization of free artemin with specific monoclonal antibodies, or by systemic treatment with a TRPM8-specific antagonist. Further, in wildtypes and mice lacking either GFRα3 or TRPM8, we tested the effects of supradural infusions of a mix of inflammatory mediators, artemin, and a TRPM8-specific agonist on migraine-related pain in mice. We find that mechanical allodynia induced by systemic nitroglycerin, or supradural infusion of inflammatory mediators, involves GFRα3. In addition, neutralization of circulating artemin reduces the nitroglycerin phenotype, demonstrating the importance of this neurotrophic pathway. Further, we show TRPM8 expression in the meninges and that direct supradural infusion of either a TRPM8-specific agonist or artemin itself produces mechanical allodynia, the latter dependent on TRPM8 and ameliorated by concurrent treatment with sumatriptan. These results indicate that neuroinflammatory events in the meninges can produce migraine-like pain in mice via artemin and GFRα3, likely acting upstream of TRPM8, providing a novel pathway that may contribute to migraine pathogenesis.

Genes of Hormone Receptors Affecting Egg Productivity and Reproductive Qualities of Chickens

The egg production of chickens is a complex polygenic type of inheritance and is controlled by many genes. The laying performance of chickens is the result of a complex process regulated by the hypothalamic-pituitary-gonadal system. This review summarizes the information on the effect of polymorphisms of follicle stimulating hormone (FSHR), luteinizing hormone (LHCGR), progesterone (PR) and prolactin (PRLR) receptor genes on the egg production and reproductive performance of chickens. The data presented show that the polymorphisms of these genes are promising for use in breeding programs to improve egg production and reproductive performance of chickens.

On the matter of composition and technological properties of uranium ores of the Semizbai deposit (North Kazakhstan)

Currently, uranium production occupies a decisive place in the world energy industry. In Kazakhstan, to meet the demand for uranium, hydrogenous deposits with technologically and economically favorable natural indicators are being developed, including the large Semizbai deposit. The deposit by genesis belongs to the hydrothermal-hydrogenous polygenic type in terrigenous sandy-clayey deposits. As a result of geological studies, the stratification of the ore-bearing deposits of the Semizbai suite was established: the lower and upper ore-bearing sub suites, the geometrization of the deposit was performed, and the morphology, number, and size of ore bodies were identified. Most of the balance reserves of the Semizbai deposit are concentrated in large and medium ore bodies. Analytical work and description of thin sections and polished sections under a microscope determined the material composition, textures, and structures of uranium ores, the main ore minerals, and their distribution in ores. When carrying out field and laboratory work, geological indicators of the deposit were obtained to select the technology for extracting ores. To select and justify the field development technology, special technological studies were carried out in the experimental area. Based on the geological indicators of uranium ores for the Semizbay deposit, well-in-situ leaching was chosen as the most rational for hydrogenous deposits. The characteristic of associated useful components of uranium ores is given, and the increased content of selenium, germanium, and scandium in them is established. The obtained research results can serve as a basis for improving the technology used for mining uranium ores and extracting associated components from them.

Review of literature: Etiology of obesity, risk factors, and the role of genetics

Obesity is considered one of the global most significant public problem as it has been associated with different diseases and even death. It is an excess accumulation of fat in the body as a result of increase calorie intake compared to energy expenditure. It is considered as multifactorial condition as many factors play role in its occurrence including genetic susceptibility, external environmental factors, individual attitude. The exact etiology of obesity is intermingled with different factors and nowadays because of development of different aspects of life, sedentary life style dominates the social communities, reduced physical activities, all these factors can enhance the risk of obesity. Furthermore, disturbances of the endocrine system like Cushing’s syndrome, hypothyroidism, diabetes type II. The genetic obesity it will be divided into two groups: 1) The monogenic type, the Poly genic type, syndrome associated obesity. Many individuals are suffering from obesity because of different genes that they already have which encourage them to high calorie diet with more food consumption, unlimited and uncontrolled food intake together with reduced physical activity. In conclusion the etiology, risk factors, as well as genetic susceptibility all are combined and correlated to each other as they may act separately or together to induce onset of obesity. The physical exercise and energy expenditure are having the key role., in addition to endocrine hormonal disturbances.

Organization of lipid centers operation in the Russian Federation — new opportunities

Project of the Russian National Atherosclerosis SocietyIn 2016, Guidelines on the medical care organization to the patients with hereditary atherogenic lipid disorders in the regions of Russia were published, which described and presented the principles of routing patients with hereditary dyslipidemia and the organization of medical care for them within the current regulatory documents. In December 2018, the Russian Ministry of Health approved clinical guidelines for the diagnosis and treatment of familial hypercholesterolemia. Thus, persons with a severe hereditary dyslipidemia were able to get free medication with expensive lipid-lowering drugs and receive apheresis. Following the European ones, the Russian guidelines on the management of lipid metabolism disorders were updated: lower target low density lipoprotein cholesterol levels were adopted. In the Russian population, there is a high prevalence of hypercholesterolemia, including familial monogenic and polygenic types. Therefore, timely detection and routing to a lipid center or an office to a specialist (cardiologist, lipidologist), adequate and modern prescription of lipid-lowering therapy will make an important contribution not only to secondary, but also to primary prevention of atherosclerotic cardiovascular complications.

Vitiligo

The prevalence of vitiligo is between 0.5% and 1% in the population, the most common acquired depigmentation disorder. Hypopigmented macules are formed as a result of melanocyte death. Its etiology is still not fully elucidated, it is a multifactorial disease. Polygenic type genetic susceptibility is supported by familial accumulation (15- 30%). The complex interaction of non-immunological and immunological factors is key during the development of the disease. Due to intensive research in recent years, it has become clear that cells other than melanocytes, such as keratinocytes, fibroblasts, natural killer (NK) cells, and other cells of the innate immune system are involved in its pathogenesis. Furthermore, a special group of T lymphocytes, the tissue-resident memory T cells, play a key role also in the development and recurrence of the disease. The aim of the treatment is to stop progression, to achieve repigmentation, which is transient in 40% of cases.

Abstract 14425: Coronary Microvascular Disease in Type 2 Diabetes is Linked to the Upregulation of P53

Diabetes mellitus is a prominent risk factor of coronary microvascular disease (CMD) and the comorbidity of CMD in diabetic patients leads to an increasing occurrence of cardiac mortality. Increased protein O -linked β-N-acetylglucosaminylation ( O -GlcNAcylation), a post-translational modification of proteins, is implicated in the development of vascular complications in diabetes. Therefore, we investigated the molecular mechanisms in which excess protein O -GlcNAcylation advances the progression of CMD in diabetes through coronary endothelial cell dysfunction. We hypothesize that excess protein O -GlcNAcylation will up-regulate p53 which will induce the development of CMD. We had conducted in vivo and in vitro experiments in control mice, TALLYHO/Jng (TH) mice, a polygenic type 2 diabetic mouse model, and endothelial cell-specific O -GlcNAcase (OGA, a regulatory enzyme that catalyzes the removal of O- GlcNAc from proteins)-overexpressing TH mice. We found that compared to control mice, TH mice exhibited a decrease in coronary flow velocity reserve (CFVR, an indicator of coronary microvascular function), reduced capillary density, and increased endothelial cell apoptosis in the left ventricle. In addition, TH mice showed a significant increase of p53 protein expression in mouse coronary endothelial cells (MCECs) compared to control mice. Moreover, overexpression of OGA lowered protein O -GlcNAcylation and decreased p53 levels in MCECs. p53 inhibition with pifithrin-α restoratively increased CFVR and cardiac contractility in TH mice. From this data, we conclude OGA overexpression lowers p53 expression levels and thus attenuates endothelial cell apoptosis and restores CFVR and cardiac function in diabetes. The downregulation of p53 through OGA overexpression could be a potential therapeutic target for CMD in diabetic patients.

Type 1 diabetes can present before the age of 6\xa0months and is characterised by autoimmunity and rapid loss of beta cells

Aims/hypothesisDiabetes diagnosed at <6 months of age is usually monogenic. However, 10–15% of affected infants do not have a pathogenic variant in one of the 26 known neonatal diabetes genes. We characterised infants diagnosed at <6 months of age without a pathogenic variant to assess whether polygenic type 1 diabetes could arise at early ages.MethodsWe studied 166 infants diagnosed with type 1 diabetes at <6 months of age in whom pathogenic variants in all 26 known genes had been excluded and compared them with infants with monogenic neonatal diabetes (n = 164) or children with type 1 diabetes diagnosed at 6–24 months of age (n = 152). We assessed the type 1 diabetes genetic risk score (T1D-GRS), islet autoantibodies, C-peptide and clinical features.ResultsWe found an excess of infants with high T1D-GRS: 38% (63/166) had a T1D-GRS >95th centile of healthy individuals, whereas 5% (8/166) would be expected if all were monogenic (p < 0.0001). Individuals with a high T1D-GRS had a similar rate of autoantibody positivity to that seen in individuals with type 1 diabetes diagnosed at 6–24 months of age (41% vs 58%, p = 0.2), and had markedly reduced C-peptide levels (median <3 pmol/l within 1 year of diagnosis), reflecting rapid loss of insulin secretion. These individuals also had reduced birthweights (median z score −0.89), which were lowest in those diagnosed with type 1 diabetes at <3 months of age (median z score −1.98).Conclusions/interpretationWe provide strong evidence that type 1 diabetes can present before the age of 6 months based on individuals with this extremely early-onset diabetes subtype having the classic features of childhood type 1 diabetes: high genetic risk, autoimmunity and rapid beta cell loss. The early-onset association with reduced birthweight raises the possibility that for some individuals there was reduced insulin secretion in utero. Comprehensive genetic testing for all neonatal diabetes genes remains essential for all individuals diagnosed with diabetes at <6 months of age.Graphical abstract

Monogenic Diabetes due to ABCC8/KCNJ11 Mutation: Case Study and Review of Literature

Monogenic diabetes arises due to mutation in a single-gene and is recognized by their striking familial inheritance pattern. This form of diabetes is inherited in an autosomal dominant or recessive fashion, unlike polygenic Type 1 (autoimmune) or type 2 diabetes caused by the combined action of more than one gene [1-11]. Monogenic diabetes is classified into three main groups: Neonatal diabetes mostly presents in the first six months of birth, maturity onset diabetes of the young (MODY) and maternally inherited mitochondrial diabetes. These mutations run in the family and have a predictable course. Most of the monogenic diabetes is treated with oral medications like sulfonylurea rather than insulin. ABCC8/KCNJ11 gene mutations also cause monogenic diabetes. This gene mutation has been found in ~50% of congenital hyperinsulinemia (CHI) patients. In such cases diabetes commonly presents in the neonatal period (transient or permanent) or at adolescence / early adulthood [1]. We present a 58-year-old diabetic lady, who was detected with ABCC8 mutation during the cascade testing [8]. She was diagnosed with diabetes at the age of 12 [8]. Her son had history of neonatal hypoglycaemia and developed diabetes at the age of 15. He was the index case who was found to have ABCC8 mutation. The family has several other members diagnosed with diabetes. The aim of the article is to increase awareness and understanding of monogenic diabetes among the medical practitioners in adult population with diabetes so that the genetic testing can be offered in a cost effective manner.

Autoinflammatory diseases in childhood, part 2: polygenic syndromes.

Autoinflammatory diseases are a family of disorders characterized by aberrant stimulation of inflammatory pathways without involvement of antigen-directed autoimmunity. They can be further divided in monogenic and polygenic types. Those without an identified genetic mutation are known as polygenic and include systemic-onset juvenile idiopathic arthritis, idiopathic recurrent acute pericarditis, Behçet syndrome, chronic recurrent multifocal osteomyelitis and inflammatory bowel disease among others. Autoinflammatory diseases are characterized by recurrent flares or persistent systemic inflammation and fever, as well as lymphadenopathy and cutaneous, abdominal, thoracic and articular symptoms. Although these syndromes can mimic infections clinically, the inflammatory lesions in autoinflammatory disorders are aseptic. However, because of their infrequency, varied and nonspecific presentation, and the new genetic identification, diagnosis is usually delayed. In this article, which is Part 2 of a two-part series, the authors review the main polygenic autoinflammatory diseases that can be seen in childhood, with special emphasis wherever applicable on imaging features that may help establish the correct diagnosis. However, the major role of imaging is to delineate organ involvement and disease extent.

Autoinflammatory diseases in childhood, part 1: monogenic syndromes.

Autoinflammatory diseases constitute a family of disorders defined by aberrant stimulation of inflammatory pathways without involving antigen-directed autoimmunity. They may be divided into monogenic and polygenic types. Monogenic autoinflammatory syndromes are those with identified genetic mutations, such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), mevalonate kinase deficiency or hyperimmunoglobulin D syndrome, cryopyrin-associated periodic fever syndromes (CAPS), pyogenic arthritis pyoderma gangrenosum and acne (PAPA) syndrome, interleukin-10 and interleukin-10 receptor deficiencies, adenosine deaminase 2 deficiency and pediatric sarcoidosis. Those without an identified genetic mutation are known as polygenic and include systemic-onset juvenile idiopathic arthritis, idiopathic recurrent acute pericarditis, Behçet syndrome, chronic recurrent multifocal osteomyelitis and inflammatory bowel disease among others. Autoinflammatory disorders are defined by repeating episodes or persistent fever, rash, serositis, lymphadenopathy, arthritis and increased acute phase reactants, and thus may mimic infections clinically. Most monogenic autoinflammatory syndromes present in childhood. However, because of their infrequency, diverse and nonspecific presentation, and the relatively new genetic recognition, diagnosis is usually delayed. In this article, which is Part 1 of a two-part series, the authors update monogenic autoinflammatory diseases in children with special emphasis on imaging features that may help establish the correct diagnosis.

&lt;i&gt;STAT4&lt;/i&gt; rs7574865 G/T and &lt;i&gt;IRF5&lt;/i&gt; rs2004640 G/T polymorphisms as markers of predisposition to juvenile idiopathic arthritis. What can genetics give to understand its heterogeneity?

Juvenile idiopathic arthritis (JIA) is a multifactorial immune-mediated inflammatory disease in childhood, the most common type of rheumatic disease in children. It is characterized by the polygenic type of hereditary predisposition.Objective:to study the association of STAT4 rs7574865 G/T and IRF5 rs2004640 G/T polymorphisms with the predisposition to certain JIA subtypes in the Russian pediatric population.Patients and methods.The investigation enrolled 177 patients, including 66 patients diagnosed with JIA and 111 healthy unrelated volunteers (a control group). Of the 66 patients with JIA there were 30 (45%) with oligoarthritis: 20 (67%) with human leukocyte antigen B27(HLA-B27)-positive JIA (that was associated with enthesitis, HLA-B27 positive JIA (JIA-B27), 10 (33%) with anterior uveitis concurrent with antinuclear antibody-positive JIA (JIA-uveitis); 20 (30%) with polyarticular JIA (JIA-poly), seronegative for rheumatoid factor; and 16 (24%) with systemic JIA (JIA-sys). As a control for genotyping STAT4 rs7574865 G/T and IRF5 rs2004640 G/T polymorphisms, the investigators studied 103 and 111 DNA samples from healthy adult volunteers, respectively. STAT4 rs7574865 G/T and IRF5 rs2004640 G/T polymorphisms were investigated using allele-specific real-time polymerase chain reaction (RT-PCR).Results and discussion.In the oligoarticular JIA group, the frequency of the STAT4 T allele was significantly higher than that in the control group (38.3 and 20.4%, respectively; p=0.004). This allele was also significantly more common in the JIA-B27 (35.0 and 20.4%, respectively; p=0.044) and JIA-uveitis (45.0 and 20.4%, respectively; p=0.021) groups compared with the control one. No significant differences were found in the frequency of the mutant STAT4 T allele between the control group and the JIA-sys and JIA-poly groups. Regression analysis showed that the identification of the STAT4 T allele was associated with the high risk of a predisposition to oligoarticular JIA as a whole (odds ratio, OR 2.43; 95% confidence interval (CI) 1.23–4.70; p=0.007), as well as to the antinuclear antibody-positive oligoarticular JIA with uveitis (JIA-uveitis): the risk in T allele carriers was 3.2 times higher than that in the control (OR 3.19; 95% CI 1.09–9.06; p= ). A high risk for predisposition was also found in the JIA-B27 subgroup compared with the control (OR 2.10; 95% CI 0.38–4.60; p=0.070). There were no statistical differences in the frequency of genotypes and alleles of the IRF5 rs2004640 G/T polymorphism between the entire group of JIA as a whole and its individual clinical types, as well as the control group.Conclusion.This pilot study confirmed that the STAT4 rs7574865 G/T polymorphism was associated with the risk of oligoarticular JIA, mainly that of JIA-uveitis and JIA-B27.

Overexpression of p53 due to excess protein O-GlcNAcylation is associated with coronary microvascular disease in type 2 diabetes.

We previously reported that increased protein O-GlcNAcylation in diabetic mice led to vascular rarefaction in the heart. In this study, we aimed to investigate whether and how coronary endothelial cell (EC) apoptosis is enhanced by protein O-GlcNAcylation and thus induces coronary microvascular disease (CMD) and subsequent cardiac dysfunction in diabetes. We hypothesize that excessive protein O-GlcNAcylation increases p53 that leads to CMD and reduced cardiac contractility. We conducted in vivo functional experiments in control mice, TALLYHO/Jng (TH) mice, a polygenic type 2 diabetic (T2D) model, and EC-specific O-GlcNAcase (OGA, an enzyme that catalyzes the removal of O-GlcNAc from proteins)-overexpressing TH mice, as well as in vitro experiments in isolated ECs from these mice. TH mice exhibited a significant increase in coronary EC apoptosis and reduction of coronary flow velocity reserve (CFVR), an assessment of coronary microvascular function, in comparison to wild-type mice. The decreased CFVR, due at least partially to EC apoptosis, was associated with decreased cardiac contractility in TH mice. Western blot experiments showed that p53 protein level was significantly higher in coronary ECs from TH mice and T2D patients than in control ECs. High glucose treatment also increased p53 protein level in control ECs. Furthermore, overexpression of OGA decreased protein O-GlcNAcylation and down-regulated p53 in coronary ECs, and conferred a protective effect on cardiac function in TH mice. Inhibition of p53 with pifithrin-α attenuated coronary EC apoptosis and restored CFVR and cardiac contractility in TH mice. The data from this study indicate that inhibition of p53 or down-regulation of p53 by OGA overexpression attenuates coronary EC apoptosis and improves CFVR and cardiac function in diabetes. Lowering coronary endothelial p53 levels via OGA overexpression could be a potential therapeutic approach for CMD in diabetes.

301-LB: Effects of Amino Acid Restriction on Development of Type 2 Diabetes in NZO Mice by FGF21 Secretion

Dietary protein restriction (PR) is emerging as an alternative approach to treat obesity and glucose intolerance since it increases plasma fibroblast growth factor 21 (FGF-21) levels. Also, dietary methionine restriction (MR) is known to mimic the metabolic effects of PR by increasing FGF-21 and inducing beneficial effects. Therefore, we tested in New Zealand Obese (NZO) mice, a model of polygenic obesity and type 2 diabetes, whether a moderate PR or a MR protects against diabetes. Moreover, we investigated whether a decreased methionine intake caused by vegetarian and vegan diets modulates plasma FGF-21 in humans. NZO mice were placed on high-fat diets that provided protein at control (18 gm%), low levels (4 gm%), or on high-fat diets (protein, 18 gm%) that provided methionine at control (0.86 gm%) or low levels (0.17 gm%) for up to 9 weeks. Changes in glucose homeostasis and energy expenditure were assessed. Among humans, plasma FGF-21 levels were investigated by comparing vegetarians and vegans to omnivores, and the effect of short-term vegetarian diet on FGF-21 induction was evaluated. PR prevented the onset of hyperglycemia only when protein was substituted by fat. When protein was substituted by carbohydrates, mice developed hyperglycemia two weeks later than the control, despite elevated plasma FGF-21 levels and increased energy expenditure. MR elevated plasma FGF-21 levels and prevented the onset of hyperglycemia. Human plasma FGF-21 levels were higher in vegans and vegetarians compared to omnivores. Interestingly, already a short-term switch to a vegetarian diet increased plasma FGF-21 in omnivores. Thus, restriction of dietary protein and methionine elevates plasma FGF-21 levels, which protect from hyperglycemia, an effect compromised by high dietary carbohydrates in NZO mice. Patients at high risk of developing type 2 diabetes may benefit from dietary changes in favor of methionine restriction, via increased circulating levels of FGF-21, without protein and calorie restriction. Disclosure T. Castaño-Martinez: None. W. Jonas: None. D. Weber: None. C. Weikert: None. T. Laeger: None. Funding Deutsche Forschungsgemeinschaft

Positive selection of type 2 diabetes genotypes – the glycaemic threshold hypothesis

The high prevalence of deleterious polygenic type 2 diabetes (T2D) is a paradox requiring explanation beyond food excess, inactivity and the obesity resulting from positive energy balance. Historically, hunting-foraging and later agrarian communities often manifested a converse negative energy balance due to nutritional deficit and/or high physical energy demand – both potentially resulting in hypoglycaemia. Since hypoglycaemia impairs both reproductive fitness and cognitive function, it is proposed that that by expressing resistance to hypoglycaemia, T2D phenotypes were subject to positive selection. The insulin resistance present in often-associated atherosclerotic cardiovascular disease, metabolic syndrome and polycystic ovarian disease may also explain their frequent coexistence and current prevalence.

Model-based pharmacokinetic and pharmacodynamic analysis for acute effects of a small molecule inhibitor of diacylglycerol acyltransferase-1 in the TallyHo/JngJ polygenic mouse

The purpose of this study was to evaluate the acute effect of a small molecule inhibitor of DGAT-1 on triglycerides (TG) and cholesterol in polygenic type 2 diabetic TallyHo/JngJ (TH) mice. PF-04620110, a potent and selective DGAT-1 inhibitor, was used as a model compound in this study and which was administered to TH and ICR mice.The concentration of the model compound that produced 50% of maximum lowering of TG level (IC50) in TH mice was not significantly different from that in ICR mice, when estimated using the model-based pharmacokinetic and pharmacodynamic assay, a two-compartmental model and an indirect response model.The clearance of the inhibitor in TH mice was fivefold higher than that in ICR mice, suggesting significantly altered pharmacokinetics. Moreover, the in vitro metabolic elimination kinetic parameters (ke,met), determined using liver microsomes from TH and ICR mice were 1.24 ± 0.14 and 0.174 ± 0.116 min−1, respectively.Thus, we report that the differences in the acute effects of the small molecule DAGT-1 inhibitor between TH mice and ICR mice can be attributed to altered pharmacokinetics caused by an altered metabolic rate for the compound in TH mice.

Association of Genetic Variability in Selected Genes in Patients With Deep Vein Thrombosis and Platelet Hyperaggregability.

The aim of this study was to evaluate the genetic variability of the selected single nucleotide polymorphisms (SNPs) and examine the association between these SNPs and risk for deep vein thrombosis (DVT) in patients with sticky platelet syndrome (SPS). We examined 84 patients with SPS and history of DVT and 101 healthy individuals. We were interested in 2 SNPs within platelet endothelial aggregation receptor 1 (PEAR1) gene (rs12041331 and rs12566888), 2 SNPs within mkurine retrovirus integration site 1 gene (rs7940646 and rs1874445), 1 SNP within Janus kinase 2 gene (rs2230722), 1 SNP within FCER1G gene (rs3557), 1 SNP within pro-platelet basic protein (rs442155), 4 SNPs within alpha2A adrenergic receptor 2A (ADRA2A; rs1800545, rs4311994, rs11195419, and rs553668), and 1 SNP within sonic hedgehog gene (rs2363910). We identified 2 protective SNPs within PEAR1 gene and 1 risk SNP within ADRA2A gene (PEAR1: rs12041331 and rs12566888; ADRA2A: rs1800545). A haplotype analysis of 4 SNPs within ADRA2A gene identified a risk haplotype aagc (P = .003). Moreover, we identified 1 protective haplotype within PEAR1 gene (AT, P = .004). Our results support the idea that genetic variability of PEAR1 and ADRA2A genes is associated with platelet hyperaggregability manifested as venous thromboembolism. The study also suggests a possible polygenic type of SPS heredity.

Case Report: Identification of an HNF1B p.Arg527Gln mutation in a Maltese patient with atypical early onset diabetes and diabetic nephropathy

BackgroundThe diagnosis of atypical non-autoimmune forms of diabetes mellitus, such as maturity onset diabetes of the young (MODY) presents several challenges, in view of the extensive clinical and genetic heterogeneity of the disease. In this report we describe a case of atypical non autoimmune diabetes associated with a damaging HNF1β mutation. This is distinguished by a number of uncharacteristic clinical features, including early-onset obesity, the absence of renal cysts and diabetic nephropathy. HNF1β-MODY (MODY5) is an uncommon form of monogenic diabetes that is often complicated by a wide array of congenital morphological anomalies of the urinary tract, including renal cysts. This report expands on the clinical phenotypes that have been described in the context of HNF1β mutations, and is relevant as only isolated cases of diabetic nephropathy in the setting of MODY5 have been reported.Case presentationAn obese Maltese female with non-autoimmune diabetes, microalbuminuria, glomerular hyperfiltration, fatty liver and no renal cysts was studied by whole exome sequencing to investigate potential genes responsible for the proband’s phenotype. A rare missense mutation at a highly conserved site in exon 8 of HNF1β was identified (c.1580G > A, NM_000458.3, p.Arg527Gln), with multiple in-silico predictions consistent with pathogenicity. This mutation has not been previously characterised. Additionally, several common susceptibility variants associated with early-onset obesity, polygenic type 2 diabetes and nephropathy were identified in the proband that could impose additional effects on the phenotype, its severity or its clinical course.ConclusionThis report highlights several atypical features in a proband with atypical diabetes associated with an HNF1β missense mutation. It also reinforces the concept that monogenic causes of diabetes could be significant contributors to disease burden in obese individuals with atypical diabetes.

A type 1 diabetes genetic risk score can discriminate monogenic autoimmunity with diabetes from early-onset clustering of polygenic autoimmunity with diabetes

Aims/hypothesisIdentifying individuals suitable for monogenic autoimmunity testing and gene discovery studies is challenging: early-onset type 1 diabetes mellitus can cluster with additional autoimmune diseases due to shared polygenic risk and islet- and other organ-specific autoantibodies are present in both monogenic and polygenic aetiologies. We aimed to assess whether a type 1 diabetes genetic risk score (GRS) could identify monogenic autoimmune diabetes and be useful to prioritise individuals for gene discovery studies.MethodsWe studied 79 individuals with diabetes and at least one additional autoimmune disease diagnosed before the age of 5 years. We screened all participants for the seven genes known to cause monogenic autoimmunity that can include diabetes (AIRE, IL2RA, FOXP3, LRBA, STAT1, STAT3, STAT5B). We genotyped the top ten risk alleles for type 1 diabetes, including HLA and non-HLA loci, to generate a type 1 diabetes GRS.ResultsOf the 79 individuals studied, 37 (47%) had mutations in the monogenic autoimmunity genes. The type 1 diabetes GRS was lower in these individuals than in those without mutations in these genes (median 9th vs 49th centile of type 1 diabetes controls, p < 0.0001). Age of diabetes diagnosis and type 1 diabetes GRS combined to be highly discriminatory of monogenic autoimmunity (receiver operating characteristic AUC: 0.88). Most individuals without a mutation in a known gene had a high type 1 diabetes GRS, suggesting that they have polygenic clustering of type 1 diabetes and additional autoimmunity and should not be included in gene discovery studies.Conclusions/interpretationWe have shown that the type 1 diabetes GRS can identify individuals likely to have monogenic autoimmunity, helping both diagnostic testing and novel monogenic autoimmunity gene discovery. Individuals with monogenic autoimmunity have a different clinical course to those with polygenic type 1 diabetes and can respond well to therapies targeting the underlying genetic defect.