Glucose induced MAPK signalling influences NeuroD1-mediated activation and nuclear localization

AbstractThe helix–loop–helix transcription factor NeuroD1 (also known as Beta2) is involved in β-cell survival during development and insulin gene transcription in adults. Here we show NeuroD1 is primarily cytoplasmic at non-stimulating glucose concentrations (i.e. 3 mM) in MIN6 β-cells and nuclear under stimulating conditions (i.e. 20 mM). Quantification revealed that NeuroD1 was in 40–45% of the nuclei at 3 mM and 80–90% at 20 mM. Treatment with the MEK inhibitor PD98059 or substitution of a serine for an alanine at a potential mitogen-activated protein kinase phosphorylation site (S274) in NeuroD1 significantly increased the cytoplasmic level at 20 mM glucose. The rise in NeuroD1-mediated transcription in response to glucose also correlated with the change in sub-cellular localization, a response attenuated by PD98059. The data strongly suggest that glucose-stimulation of the MEK–ERK signalling pathway influences NeuroD1 activity at least partially through effects on sub-cellular localization

Insulin gene regulation and islet development as studied in genetically modified tumors and transgenic laboratory animals

The pancreatic islet of Langerhans is composed of four highly distinct cell types specialized to mass produce a particular hormone. Insulin is thus the main product released from the islet B—cell in response to elevated glucose.The four cell types maturate during fetal development. Pluripotent rat islet tumors can to a certain degree undergo similar maturation processes when passaged in vivo. Such a model has been used to study the B—cell specific process of insulin gene activation. Transgenic mice have been instrumental in defining the functional regulatory elements involved in restricting the insulin gene activity to the pancreatic B-cell. The tissue-specific enhancer/promoter has thus been identified and used in combination with a series of other genes which in transgenic mice targets expression of the gene in question selectively to the B-cell. Important transacting factors have been identified and cloned which are in part responsible for mediating tissue specific insulin gene expression. One such factor when "knocked-out" results in a phenotype lacking the entire pancreas. Future developments in targeting "knockout" of genes to particular cell types will help dissecting out the multiple functions of such regulatory transacting factors

Laboratory Diagnostics of <i>Rickettsia</i> Infections in Denmark 2008–2015

Rickettsiosis is a vector-borne disease caused by bacterial species in the genus Rickettsia. Ticks in Scandinavia are reported to be infected with Rickettsia, yet only a few Scandinavian human cases are described, and rickettsiosis is poorly understood. The aim of this study was to determine the prevalence of rickettsiosis in Denmark based on laboratory findings. We found that in the Danish individuals who tested positive for Rickettsia by serology, the majority (86%; 484/561) of the infections belonged to the spotted fever group. In contrast, we could confirm 13 of 41 (32%) PCR-positive individuals by sequencing and identified all of these as R. africae, indicating infections after travel exposure. These 13 samples were collected from wound/skin material. In Denmark, approximately 85 individuals test positive for Rickettsia spp. annually, giving an estimated 26% (561/2147) annual prevalence among those suspected of rickettsiosis after tick bites. However, without clinical data and a history of travel exposure, a true estimation of rickettsiosis acquired endemically by tick bites cannot be made. Therefore, we recommend that both clinical data and specific travel exposure be included in a surveillance system of Rickettsia infections

Pax6 and Cdx2/3 form a functional complex on the rat glucagon gene promoter G1-element

Abstractα-cell specific transcription of the glucagon gene is mainly conferred by the glucagon promoter G1-element, while additional elements G2, G3, and G4 have broad islet cell specificity. Transcription of the glucagon gene has been shown to be stimulated by Pax6 through binding to the glucagon gene promoter G3-element. In this report, we show that Pax6 additionally binds the glucagon gene promoter G1-element and forms a transcriptionally active complex with another homeodomain protein, Cdx2/3. Two distinct mutations in the G1-element, that both reduce promoter activity by 85–90%, is shown to eliminate binding of either Pax6 or Cdx2/3. Additionally, Pax6 enhanced Cdx2/3 mediated activation of a glucagon reporter in heterologous cells. We discuss how Pax6 may contribute to cell-type specific transcription in the pancreatic islets by complex formation with different transcription factors

Multifactorial intervention to prevent cardiovascular disease in patients with early rheumatoid arthritis:protocol for a multicentre randomised controlled trial

INTRODUCTION: Cardiovascular morbidity is a major burden in patients with rheumatoid arthritis (RA). In this study, we compare the effect of a targeted, intensified, multifactorial intervention with that of conventional treatment of modifiable risk factors for cardiovascular disease (CVD) in patients with early RA fulfilling the 2010 American College of Rheumatology European League Against Rheumatism (ACR/EULAR) criteria. METHODS AND ANALYSIS: The study is a prospective, randomised, open label trial with blinded end point assessment and balanced randomisation (1:1) conducted in 10 outpatient clinics in Denmark. The primary end point after 5 years of follow-up is a composite of death from cardiovascular causes, non-fatal myocardial infarction, non-fatal stroke and cardiac revascularisation. Secondary outcomes are: the proportion of patients achieving low-density lipoprotein cholesterol <2.5 mmol/L, glycated haemoglobin <48 mmol/mol, blood pressure <140/90 mm  Hg for patients without diabetes and <130/80 mm Hg for patients with diabetes and normoalbuminuria (urinary albumin creatinine ratio <30 mg/g) after 1 year of follow-up and the proportion of patients in each treatment group achieving low RA disease activity after 1 year, defined as a disease activity score C-reactive protein (DAS28-CRP) <3.2 and a DAS28-CRP score <2.6 after 12, 24 and 60 months. Furthermore, all hospitalisations for acute and elective reasons will be adjudicated by the event committee after 12, 24 and 60 months. Three hundred treatment-naive patients with early RA will be randomly assigned (1:1) to receive either conventional treatment administered and monitored by their general practitioner according to national guidelines (control group) or a stepwise implementation administered and monitored in a quarterly rheumatological nurse-administered set-up of behaviour modification and pharmacological therapy targeting (1) hyperlipidaemia, (2) hypertension, (3) hyperglycaemia and (4) microalbuminuria (intervention group). ETHICS AND DISSEMINATION: This protocol is approved by the local ethics committee (DK-S-2014007) and The Danish Health and Medicines Authority. Dissemination will occur through presentations at National and International conferences and publications in international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT0224625

The Etiology of Multiple Sclerosis: Genetic Evidence for the Involvement of the Human Endogenous Retrovirus HERV-Fc1

We have investigated the role of human endogenous retroviruses in multiple sclerosis by analyzing the DNA of patients and controls in 4 cohorts for associations between multiple sclerosis and polymorphisms near viral restriction genes or near endogenous retroviral loci with one or more intact or almost-intact genes. We found that SNPs in the gene TRIM5 were inversely correlated with disease. Conversely, SNPs around one retroviral locus, HERV-Fc1, showed a highly significant association with disease. The latter association was limited to a narrow region that contains no other known genes. We conclude that HERV-Fc1 and TRIM5 play a role in the etiology of multiple sclerosis. If these results are confirmed, they point to new modes of treatment for multiple sclerosis