Quantitative TaqMan® real-time PCR assays for gene expression normalisation in feline tissues

ABSTRACT: BACKGROUND: Gene expression analysis is an important tool in contemporary research, with real-time PCR as the method of choice for quantifying transcription levels. Co-analysis of suitable reference genes is crucial for accurate expression normalisation. Reference gene expression may vary, e.g., among species or tissues; thus, candidate genes must be tested prior to use in expression studies. The domestic cat is an important study subject in both medical research and veterinary medicine. The aim of the present study was to develop TaqMan(R) real-time PCR assays for eight potential reference genes and to test their applicability for feline samples, including blood, lymphoid, endocrine, and gastrointestinal tissues from healthy cats, and neoplastic tissues from FeLV-infected cats. RESULTS: RNA extraction from tissues was optimised for minimal genomic DNA (gDNA) contamination without use of a DNase treatment. Real-time PCR assays were established and optimised for v-abl Abelson murine leukaemia viral oncogene homolog (ABL), beta-actin (ACTB), beta-2-microglobulin (B2M), beta-glucuronidase (GUSB), hydroxymethyl-bilane synthase (HMBS), hypoxanthine phosphoribosyltransferase (HPRT), ribosomal protein S7 (RPS7), and tryptophan 5-monooxygenase activation protein, zeta polypeptide (YWHAZ). The presence of pseudogenes was confirmed for four of the eight investigated genes (ACTB, HPRT, RPS7, and YWHAZ). The assays were tested together with previously developed TaqMan(R) assays for feline glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the universal 18S rRNA gene. Significant differences were found among the expression levels of the ten candidate reference genes, with a ~10;6-fold expression difference between the most abundant (18S rRNA) and the least abundant genes (ABL, GUSB, and HMBS). The expression stability determined by the geNorm and NormFinder programs differed significantly. Using the ANOVA-based NormFinder program, RPS7 was the most stable gene in the tissues studied, followed by ACTB and ABL; B2M, HPRT, and the 18S rRNA genes were the least stable ones. CONCLUSION: The reference gene expression stability varied considerably among the feline tissues investigated. No tested gene was optimal for normalisation in all tissues. For the majority of the tissues, two to three reference genes were necessary for accurate normalisation. The present study yields essential information on the correct choice of feline reference genes depending on the tissues analysed

Diagnosis of quarantine organisms at the JKI in the National Reference Laboratory for organisms harmful to plants

Dem JKI wurde im April 2019 durch das Bundesministerium für Ernährung und Landwirtschaft (BMEL) die Funktion des nationalen Referenzlaboratoriums (NRL) für Schadorganismen der Pflanzen zugewiesen. Mit dieser Funktion des NRL für Deutschland sind bestimmte Zuständigkeiten und Aufgaben verbunden, die in der EU-Verordnung 2017/625 (EU, 2017) geregelt sind. Dazu gehören auch Referenzuntersuchungen bzw. die Diag­nose von Quarantäneschadorganismen (QSO). Das NRL stellt eine übergeordnete Einheit innerhalb des JKI dar. Durch insgesamt 14 Prüflabore der JKI-Institute für Pflanzenschutz in Ackerbau und Grünland (A), nationale und internationale Angelegenheiten der Pflanzengesundheit (AG), Epidemiologie und Pathogendiagnostik (EP), Pflanzenschutz in Gartenbau und Forst (GF), Pflanzenschutz in Obst- und Weinbau (OW) wird die Referenzfunktion bei der Diagnose zu verschiedensten (Quarantäne)-Schadorganismen der Pathogengruppen Bakterien, Insekten, Nematoden, Pilze (einschließlich Oomyceten), Phytoplasmen und Viren wahrgenommen.In April 2019, the JKI was officially designated as the Natio­nal Reference Laboratory (NRL) for organisms harmful to plants by the Federal Ministry of Food and Agri­culture (BMEL). This function as NRL for Germany is associated with certain responsibilities and tasks, which are specified in the EU Regulation 2017/625 (EU, 2017). This also includes reference tests and the diagnosis of quarantine pests, respectively. The NRL represents a super­ordinate unit inside JKI. A total of 14 test laboratories from different JKI institutes, namely for Plant Protection in Field Crops and Grassland (A), for National and International Plant Health (AG), for Epidemiology and Pathogen Diagnostics (EP), Plant Protection in Horti­culture and Forests (GF), and for Plant Protection in Fruit Crops and Viticulture (OW) are in charge to carry out a reference function in the diagnosis of (quarantine) pests in the pathogen groups of bacteria, fungi (including oomycetes), insects, nematodes, phytoplasma und viruses

“Ryanopathies” and RyR2 dysfunctions: can we further decipher them using in vitro human disease models?

International audienceThe regulation of intracellular calcium (Ca 2+ ) homeostasis is fundamental to maintain normal functions in many cell types. The ryanodine receptor (RyR), the largest intracellular calcium release channel located on the sarco/endoplasmic reticulum (SR/ER), plays a key role in the intracellular Ca 2+ handling. Abnormal type 2 ryanodine receptor (RyR2) function, associated to mutations (ryanopathies) or pathological remodeling, has been reported, not only in cardiac diseases, but also in neuronal and pancreatic disorders. While animal models and in vitro studies provided valuable contributions to our knowledge on RyR2 dysfunctions, the human cell models derived from patients’ cells offer new hope for improving our understanding of human clinical diseases and enrich the development of great medical advances. We here discuss the current knowledge on RyR2 dysfunctions associated with mutations and post-translational remodeling. We then reviewed the novel human cellular technologies allowing the correlation of patient’s genome with their cellular environment and providing approaches for personalized RyR-targeted therapeutics

NETT Coordinators: Researchers, Caregivers, or Both?

The National Emphysema Treatment Trial (NETT) required the coordinated evaluation and treatment of thousands of patients with emphysema simultaneous with data collection to evaluate the safety and efficacy of surgery versus medical treatment for emphysema. These tasks were performed by a multidisciplinary team led by the clinic coordinator at each NETT center. The clinic coordinators functioned as members of the research team as well as communicators, managers, and members of the patient care team. The clinic coordinators' ability to balance these roles was instrumental to the successful completion of NETT, as evidenced by randomization of 1,218 subjects with only 10 subjects being lost to follow-up. Striving to achieve recruitment goals and working to retain study subjects was very labor intensive. The coordinator role was complicated by the study population's severity of illness combined with the complexity of the NETT protocol. Management of the study subjects' medical condition had to be balanced with the management of a multicenter, randomized clinical trial to ensure quality data collection and protocol adherence

Multidisciplinary Care of the Patient with Chronic Obstructive Pulmonary Disease

The National Emphysema Treatment Trial used a multidisciplinary team approach to implement the maximum medical care protocol, including adjustment of medications and outpatient pulmonary rehabilitation for all patients and nutritional and psychological counseling as needed. This article discusses the benefits of such an approach in the care of the patient with chronic obstructive pulmonary disease. Team member roles complement each other and contribute to the goal of providing the highest-quality medical care. The primary focus of the team is to reinforce the medical plan and to provide patient education and support. This article reviews the elements of the initial patient assessment and the functional and nutritional assessment. Patient education focuses on medication use, recognition and management of chronic obstructive pulmonary disease exacerbation symptoms, smoking cessation, advance directives, and travel

The PPARγ pathway determines electrophysiological remodelling and arrhythmia risks in DSC2 arrhythmogenic cardiomyopathy

International audienceNo abstract availabl

Clinical characteristics and prediction of pulmonary hypertension in severe emphysema

SummaryBackgroundWe explored the prevalence, clinical and physiologic correlates of pulmonary hypertension (PH), and screening strategies in patients with severe emphysema evaluated for the National Emphysema Treatment Trial (NETT).MethodsPatients undergoing Doppler echocardiography (DE) and right heart catheterization were included. Patients with mean pulmonary arterial pressure ≥25 mmHg (PH Group) were compared to the remainder (non-PH Group).ResultsOf 797 patients, 302 (38%) had PH and 18 (2.2%) had severe PH. Compared to the non-PH Group, patients with PH had lower % predicted FEV1 (p < 0.001), % predicted diffusion capacity for carbon monoxide (p = 0.006), and resting room air PaO2 (p < 0.001). By multivariate analysis, elevated right ventricular systolic pressure, reduced resting room air PaO2, reduced post-bronchodilator % predicted FEV1, and enlarged pulmonary arteries on computed tomographic scan were the best predictors of PH. A strategy using % predicted FEV1, % predicted DLCO, PaO2, and RVSP was predictive of the presence of pre-capillary PH and was highly predictive of its absence.ConclusionsMildly elevated pulmonary artery pressures are found in a significant proportion of patients with severe emphysema. However, severe PH is uncommon in the absence of co-morbidities. Simple non-invasive tests may be helpful in screening patients for pre-capillary PH in severe emphysema but none is reliably predictive of its presence

Oxygen Is an Ambivalent Factor for the Differentiation of Human Pluripotent Stem Cells in Cardiac 2D Monolayer and 3D Cardiac Spheroids

Numerous protocols of cardiac differentiation have been established by essentially focusing on specific growth factors on human pluripotent stem cell (hPSC) differentiation efficiency. However, the optimal environmental factors to obtain cardiac myocytes in network are still unclear. The mesoderm germ layer differentiation is known to be enhanced by low oxygen exposure. Here, we hypothesized that low oxygen exposure enhances the molecular and functional maturity of the cardiomyocytes. We aimed at comparing the molecular and functional consequences of low (5% O2 or LOE) and high oxygen exposure (21% O2 or HOE) on cardiac differentiation of hPSCs in 2D- and 3D-based protocols. hPSC-CMs were differentiated through both the 2D (monolayer) and 3D (embryoid body) protocols using several lines. Cardiac marker expression and cell morphology were assessed. The mitochondrial localization and metabolic properties were evaluated. The intracellular Ca2+ handling and contractile properties were also monitored. The 2D cardiac monolayer can only be differentiated in HOE. The 3D cardiac spheroids containing hPSC-CMs in LOE further exhibited cardiac markers, hypertrophy, steadier SR Ca2+ release properties revealing a better SR Ca2+ handling, and enhanced contractile force. Preserved distribution of mitochondria and similar oxygen consumption by the mitochondrial respiratory chain complexes were also observed. Our results brought evidences that LOE is moderately beneficial for the 3D cardiac spheroids with hPSC-CMs exhibiting further maturity. In contrast, the 2D cardiac monolayers strictly require HOE

Modeling polymorphic ventricular tachycardia at rest using patient-specific induced pluripotent stem cell-derived cardiomyocytes

International audienceBackground: While mutations in the cardiac type 2 ryanodine receptor (RyR2) have been linked to exercise-induced or catecholaminergic polymorphic ventricular tachycardia (CPVT), its association with polymorphic ventricular tachycardia (PMVT) occurring at rest is unclear. We aimed at constructing a patient-specific human-induced pluripotent stem cell (hiPSC) model of PMVT occurring at rest linked to a single point mutation in RyR2.Methods: Blood samples were obtained from a patient with PMVT at rest due to a heterozygous RyR2-H29D mutation. Patient-specific hiPSCs were generated from the blood samples, and the hiPSC-derived cardiomyocytes (CMs) were generated via directed differentiation. Using CRIPSR/Cas9 technology, isogenic controls were generated by correcting the RyR2-H29D mutation. Using patch-clamp, fluorescent confocal microscopy and video-image-based analysis, the molecular and functional properties of RyR2-H29D hiPSCsingle bondCMs and control hiPSCsingle bondCMs were compared.Findings: RyR2-H29D hiPSCsingle bondCMs exhibit intracellular sarcoplasmic reticulum (SR) Ca2+ leak through RyR2 under physiological pacing. RyR2-H29D enhances the contribution of inositol 1,4,5-trisphosphate receptors to excitation-contraction coupling (ECC) that exacerbates abnormal Ca2+ release in RyR2-H29D hiPSCsingle bondCMs. RyR2-H29D hiPSCsingle bondCMs exhibit shorter action potentials, delayed afterdepolarizations, arrhythmias and aberrant contractile properties compared to isogenic controls. The RyR2-H29D mutation causes post-translational remodeling that is fully reversed with isogenic controls.Interpretation: To conclude, in a model based on a RyR2 point mutation that is associated with short-coupled PMVT at rest, RyR2-H29D hiPSCsingle bondCMs exhibited aberrant intracellular Ca2+ homeostasis, shortened action potentials, arrhythmias and abnormal contractile properties