Fluorescence in situ hybridisation study of micronuclei in C3A cells following exposure to ELF-magnetic fields

Human C3A cells were exposed to extremely low frequency (50 Hz) magnetic fields (ELF-MF's) up to 500 mu T. They were subjected to the micronucleus assay using a Fluorescence In Situ Hybridization (FISH) technique with an in-house pan-centromere probe. We found no increased frequency in micronucleated cells and no change in the proportion of centromere positive over centromere negative micronuclei compared to the unexposed control cells. These results are in accordance with some, but in contradiction with other previously published investigations underlining that effects of environmental ELF-EMF's on cellular DNA may be very subtle and that small changes or environmental influences may determine the outcome of a (geno)toxicity study. Interestingly, a low-level (5 mu T) exposure resulted in less than the background micronucleus frequency

Camelid reporter gene imaging: a generic method for in vivo cell tracking

BACKGROUND: To combine the sensitivity of bioluminescent imaging (BLI) with the 3D and quantitative properties of pinhole single-photon emission computed tomography (SPECT)/micro-computed tomography (CT) (phSPECT/micro-CT), we generated stable cell lines that express a yellow-fluorescent protein (YFP) and Gaussia luciferase (GLuc) fusion protein (YFP/GLuc). For in vivo phSPECT detection of this YFP/GLuc protein, a nanobody, targeted against yellow and green fluorescent proteins (anti-YFP-Nb), was site specifically labelled with (99m)Tc. METHODS: Human embryonic kidney cells (HEK293T) were cultured and passaged every 3 days. 10E5 cells were transduced with YFP/GLuc-containing vector: both membrane-targeted (MT-YFP/GLuc) and non-targeted (YFP/GLuc) fusion proteins were developed. These vectors were compared against a SKOV-3 cell line stably expressing green fluorescent-firefly luciferase (GFP/Fluc) and HEK293T cells expressing red fluorescent protein in combination with a Gaussia luciferase (Red/GLuc). Transduction efficiencies were scored by fluorescence microscopy, and transduced cells were enriched by fluorescence-activated cell sorting (FACS). GLuc and FLuc functionality was tested in vitro by list-mode BLI. Subsequently, cells were transplanted subcutaneously in athymic (nu/nu) mice (MT-YFP/GLuc: n = 4, YFP/GLuc: n = 6, GFP/FLuc: n = 6, Red/GLuc: n = 4). Labelling efficiency of anti-YFP-Nb was measured using instant thin layer chromatography. One week after transplantation, (99m)Tc-labelled anti-YFP-Nb was injected intravenously and pinhole (ph) SPECT/micro-CT was performed, followed by in vivo BLI. RESULTS: Cells showed high levels of fluorescence after transduction. The cells containing the MT-YFP/GLuc were positive on fluorescence microscopy, with the fluorescent signal confined to the cell membrane. After cell sorting, transduced cells were assayed by BLI and showed a significantly higher light output both in vitro and in vivo compared with non-transduced HEK293T cells. The anti-YFP-Nb labelling efficiency was 98%, and subsequent phSPECT/micro-CT demonstrated visible cell binding and significantly higher transplant-to-muscle ratio for both the MT-YFP/GLuc and YFP/GLuc transplanted cells, compared with the GFP/FLuc and Red/GLuc group. CONCLUSION: This study provides a proof of principle for a nanobody-based cell tracking method, using a YFP/GLuc fusion protein and anti-YFP-Nb in a model of subcutaneously transplanted transduced HEK293T cells

A Whole-Genome RNA Interference Screen Reveals a Role for Spry2 in Insulin Transcription and the Unfolded Protein Response.

Insulin production by the pancreatic β-cell is required for normal glucose homeostasis. While key transcription factors that bind to the insulin promoter are known, relatively little is known about the upstream regulators of insulin transcription. Using a whole-genome RNA interference screen, we uncovered 26 novel regulators of insulin transcription that regulate diverse processes including oxidative phosphorylation, vesicle traffic, and the unfolded protein response (UPR). We focused on Spry2-a gene implicated in human type 2 diabetes by genome-wide association studies but without a clear connection to glucose homeostasis. We showed that Spry2 is a novel UPR target and its upregulation is dependent on PERK. Knockdown of Spry2 resulted in reduced expression of Serca2, reduced endoplasmic reticulum calcium levels, and induction of the UPR. Spry2 deletion in the adult mouse β-cell caused hyperglycemia and hypoinsulinemia. Our study greatly expands the compendium of insulin promoter regulators and demonstrates a novel β-cell link between Spry2 and human diabetes

Semi-automated digital measurement as the method of choice for beta cell mass analysis

Pancreas injury by partial duct ligation (PDL) activates beta cell differentiation and proliferation in adult mouse pancreas but remains controversial regarding the anticipated increase in beta cell volume. Several reports unable to show beta cell volume augmentation in PDL pancreas used automated digital image analysis software. We hypothesized that fully automatic beta cell morphometry without manual micrograph artifact remediation introduces bias and therefore might be responsible for reported discrepancies and controversy. However, our present results prove that standard digital image processing with automatic thresholding is sufficiently robust albeit less sensitive and less adequate to demonstrate a significant increase in beta cell volume in PDL versus Sham-operated pancreas. We therefore conclude that other confounding factors such as quality of surgery, selection of samples based on relative abundance of the transcription factor Neurogenin 3 (Ngn3) and tissue processing give rise to inter-laboratory inconsistencies in beta cell volume quantification in PDL pancreas

(Re)generating human beta cells : status, pitfalls, and perspectives

Diabetes mellitus results from disturbed glucose homeostasis due to an absolute (type 1) or relative (type 2) deficiency of insulin, a peptide hormone almost exclusively produced by the beta cells of the endocrine pancreas in a tightly regulated manner. Current therapy only delays disease progression through insulin injection and/or oral medications that increase insulin secretion or sensitivity, decrease hepatic glucose production, or promote glucosuria. These drugs have turned diabetes into a chronic disease as they do not solve the underlying beta cell defects or entirely prevent the long-term complications of hyperglycemia. Beta cell replacement through islet transplantation is a more physiological therapeutic alternative but is severely hampered by donor shortage and immune rejection. A curative strategy should combine newer approaches to immunomodulation with beta cell replacement. Success of this approach depends on the development of practical methods for generating beta cells, either in vitro or in situ through beta cell replication or beta cell differentiation. This review provides an overview of human beta cell generation

ROBO2 is a stroma suppressor gene in the pancreas and acts via TGF-β signalling

Whereas genomic aberrations in the SLIT-ROBO pathway are frequent in pancreatic ductal adenocarcinoma (PDAC), their function in the pancreas is unclear. Here we report that in pancreatitis and PDAC mouse models, epithelial Robo2 expression is lost while Robo1 expression becomes most prominent in the stroma. Cell cultures of mice with loss of epithelial Robo2 (Pdx1 ;Robo2 ) show increased activation of Robo1 myofibroblasts and induction of TGF-β and Wnt pathways. During pancreatitis, Pdx1 ;Robo2 mice present enhanced myofibroblast activation, collagen crosslinking, T-cell infiltration and tumorigenic immune markers. The TGF-β inhibitor galunisertib suppresses these effects. In PDAC patients, ROBO2 expression is overall low while ROBO1 is variably expressed in epithelium and high in stroma. ROBO2 ;ROBO1 patients present the poorest survival. In conclusion, Robo2 acts non-autonomously as a stroma suppressor gene by restraining myofibroblast activation and T-cell infiltration. ROBO1/2 expression in PDAC patients may guide therapy with TGF-β inhibitors or other stroma /immune modulating agents

Enabling planetary science across light-years. Ariel Definition Study Report

Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed and how they evolve, by surveying a diverse sample of about 1000 extrasolar planets, simultaneously in visible and infrared wavelengths. It is the first mission dedicated to measuring the chemical composition and thermal structures of hundreds of transiting exoplanets, enabling planetary science far beyond the boundaries of the Solar System. The payload consists of an off-axis Cassegrain telescope (primary mirror 1100 mm x 730 mm ellipse) and two separate instruments (FGS and AIRS) covering simultaneously 0.5-7.8 micron spectral range. The satellite is best placed into an L2 orbit to maximise the thermal stability and the field of regard. The payload module is passively cooled via a series of V-Groove radiators; the detectors for the AIRS are the only items that require active cooling via an active Ne JT cooler. The Ariel payload is developed by a consortium of more than 50 institutes from 16 ESA countries, which include the UK, France, Italy, Belgium, Poland, Spain, Austria, Denmark, Ireland, Portugal, Czech Republic, Hungary, the Netherlands, Sweden, Norway, Estonia, and a NASA contribution

Cent scientifiques répliquent à SEA (Suppression des Expériences sur l’Animal vivant) et dénoncent sa désinformation

La lutte contre la maltraitance animale est sans conteste une cause moralement juste. Mais elle ne justifie en rien la désinformation à laquelle certaines associations qui s’en réclament ont recours pour remettre en question l’usage de l’expérimentation animale en recherche

UNE VARIANTE CLINIQUE INHABITUELLE DE LA PUBALGIE CHEZ LA FEMME: LE CAS D'UNE SPORTIVE

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Les diagnostics difficiles dans le cancer du sein.

A detailed senologic evaluation with complete clinical examination, (color Doppler) echography, comparative mammography and cytology or microbiopsy can avoid surgery in case of a post-traumatic fat necrosis, a Mondor Syndrome, an infectious mastitis or a ductal ecstasy with nipple discharge. Actually we have still difficulties to interpret non palpable breast lesions and to supervise operated and radiated breasts.SCOPUS: ar.jinfo:eu-repo/semantics/publishe