Heterotypic cell-cell interaction of human stem cells for neural differentiation of hybrid spheroids

Organoids, the condensed 3-D tissues emerged at the early stage of organogenesis, are a promising approach to regenerate functional and vascularized organ mimics [1]. While incorporation of heterotypic cell types such as human mesenchymal stem cells (hMSCs) and human induced pluripotent stem cells (hiPSCs) derived neural progenitors aid neural organ development, the interactions of secreted factors during neurogenesis have not been well understood. The objective of this study is to investigate the impact of the composition and structure of 3-D hybrid spheroids of hiPSCs and hMSCs on dorsal cortical differentiation and the secretion of extracellular matrices and trophic factors in vitro. The hybrid spheroids were formed at different hiPSC:hMSC ratios (100:0, 75:25, 50:50, 25:75, 0:100) using direct mixing or pre-hiPSC aggregation method, which generated dynamic spheroid structure. The cellular organization, proliferation, neural marker expression, the secretion of extracellular matrix proteins and the cytokines were characterized. The incorporation of MSCs upregulated Nestin and β-tubulin III expression (the dorsal cortical identity was shown by Pax6 and TBR1 expression), matrix remodeling proteins and the secretion of transforming growth factor-β1 and prostaglandin E2. This study indicates that the appropriate composition and structure of hiPSC-MSC spheroids promote neural differentiation and trophic factor and matrix secretion due to the heterotypic cell-cell interactions. Please click Additional Files below to see the full abstract

Microfluidic platform to study pressure-induced changes in neurons

Purpose : Explore a model for glaucoma by developing methods to image Caenorhabditis elegans neuronal function in response to controlled pressure modulation. Methods : Microfluidic devices have been developed for imaging behavior and cellular processes in C. elegans. These devices are fabricated using polydimethylsiloxane (PDMS), an inert polymer. External pressure is adjusted to immobilize the animal as well as to control flow of solutions in the devices (Figure 1a). Here we developed and tested modified versions of microfluidic devices (Hulme et al 2007, Cho et al 2014, Figure 1). These devices use pressure to hold the animals and allow for fluorescent imaging (Figure 2). The chips were designed in AutoCAD (Autodesk). Previously published protocols were used to make the PDMS replicas. Devices were controlled using an external valve system to regulate pressure in these channels. External components were built according to published protocols to automate the valve system (Rafael Gomez-Sjoberg, Microfluidics Lab, Lawrence Berkeley National Laboratory). Animals were imaged on a Zeiss 710 or Zeiss Axioscope inverted microscope. GCamP3 signals was used to confirm the function of the sensory neurons and prab-3 driven mcherry was used to visualize vesicles in axons. Results : Animals were successfully immobilized and intermittently imaged up to 6 hours in tapered microfluidic devices (n=15). All animal survived and there was no significant change in the function of the sensory neurons following immobilization at 5 psi in the tapered channels. Pressures of 20psi were tested in these devices without malfunction of the devices. Vesicular markers were visualized these devices, which is promising for the further characterization of dynamics of axonal transport in the model. Conclusions : Glaucoma is associated with high intraocular pressures and characterized by accelerated loss of retinal ganglion cells and their axons. Impaired axonal transport has been implicated as a pathogenic mechanism in glaucoma and impaired axonal transport along retinal ganglion cells has been demonstrated in animal and human glaucoma studies (Knox et. Al 2007). Here we show that external pressure can be modulated in these devices while allowing for simultaneous neuronal imaging. Caenorhabditis elegans provides a tractable nervous system with accessible genetic tools that can be used to study real-time neuronal and axonal response to direct pressure modulation

Microfluidic platform to study pressure-induced changes in neurons

Purpose : Explore a model for glaucoma by developing methods to image Caenorhabditis elegans neuronal function in response to controlled pressure modulation. Methods : Microfluidic devices have been developed for imaging behavior and cellular processes in C. elegans. These devices are fabricated using polydimethylsiloxane (PDMS), an inert polymer. External pressure is adjusted to immobilize the animal as well as to control flow of solutions in the devices (Figure 1a). Here we developed and tested modified versions of microfluidic devices (Hulme et al 2007, Cho et al 2014, Figure 1). These devices use pressure to hold the animals and allow for fluorescent imaging (Figure 2). The chips were designed in AutoCAD (Autodesk). Previously published protocols were used to make the PDMS replicas. Devices were controlled using an external valve system to regulate pressure in these channels. External components were built according to published protocols to automate the valve system (Rafael Gomez-Sjoberg, Microfluidics Lab, Lawrence Berkeley National Laboratory). Animals were imaged on a Zeiss 710 or Zeiss Axioscope inverted microscope. GCamP3 signals was used to confirm the function of the sensory neurons and prab-3 driven mcherry was used to visualize vesicles in axons. Results : Animals were successfully immobilized and intermittently imaged up to 6 hours in tapered microfluidic devices (n=15). All animal survived and there was no significant change in the function of the sensory neurons following immobilization at 5 psi in the tapered channels. Pressures of 20psi were tested in these devices without malfunction of the devices. Vesicular markers were visualized these devices, which is promising for the further characterization of dynamics of axonal transport in the model. Conclusions : Glaucoma is associated with high intraocular pressures and characterized by accelerated loss of retinal ganglion cells and their axons. Impaired axonal transport has been implicated as a pathogenic mechanism in glaucoma and impaired axonal transport along retinal ganglion cells has been demonstrated in animal and human glaucoma studies (Knox et. Al 2007). Here we show that external pressure can be modulated in these devices while allowing for simultaneous neuronal imaging. Caenorhabditis elegans provides a tractable nervous system with accessible genetic tools that can be used to study real-time neuronal and axonal response to direct pressure modulation

Missing OH reactivity in the global marine boundary layer

The hydroxyl radical (OH) reacts with thousands of chemical species in the atmosphere, initiating their removal and the chemical reaction sequences that produce ozone, secondary aerosols, and gas-phase acids. OH reactivity, which is the inverse of OH lifetime, influences the OH abundance and the ability of OH to cleanse the atmosphere. The NASA Atmospheric Tomography (ATom) campaign used instruments on the NASA DC-8 aircraft to measure OH reactivity and more than 100 trace chemical species. ATom presented a unique opportunity to test the completeness of the OH reactivity calculated from the chemical species measurements by comparing it to the measured OH reactivity over two oceans across four seasons. Although the calculated OH reactivity was below the limit of detection for the ATom instrument used to measure OH reactivity throughout much of the free troposphere, the instrument was able to measure the OH reactivity in and just above the marine boundary layer. The mean measured value of OH reactivity in the marine boundary layer across all latitudes and all ATom deployments was 1.9 s⁻¹, which is 0.5 s⁻¹ larger than the mean calculated OH reactivity. The missing OH reactivity, the difference between the measured and calculated OH reactivity, varied between 0 and 3.5 s⁻¹, with the highest values over the Northern Hemisphere Pacific Ocean. Correlations of missing OH reactivity with formaldehyde, dimethyl sulfide, butanal, and sea surface temperature suggest the presence of unmeasured or unknown volatile organic compounds or oxygenated volatile organic compounds associated with ocean emissions

Fasting Induces the Expression of PGC-1α and ERR Isoforms in the Outer Stripe of the Outer Medulla (OSOM) of the Mouse Kidney

Peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α) is a member of the transcriptional coactivator family that plays a central role in the regulation of cellular energy metabolism under various physiological stimuli. During fasting, PGC-1α is induced in the liver and together with estrogen-related receptor a and γ (ERRα and ERRγ, orphan nuclear receptors with no known endogenous ligand, regulate sets of genes that participate in the energy balance program. We found that PGC-1α, ERRα and ERRγ was highly expressed in human kidney HK2 cells and that PGC-1α induced dynamic protein interactions on the ERRα chromatin. However, the effect of fasting on the expression of endogenous PGC-1α, ERRα and ERRγ in the kidney is not known.In this study, we demonstrated by qPCR that the expression of PGC-1α, ERRα and ERRγ was increased in the mouse kidney after fasting. By using immunohistochemistry (IHC), we showed these three proteins are co-localized in the outer stripe of the outer medulla (OSOM) of the mouse kidney. We were able to collect this region from the kidney using the Laser Capture Microdissection (LCM) technique. The qPCR data showed significant increase of PGC-1α, ERRα and ERRγ mRNA in the LCM samples after fasting for 24 hours. Furthermore, the known ERRα target genes, mitochondrial oxidative phosphorylation gene COX8H and the tricarboxylic acid (TCA) cycle gene IDH3A also showed an increase. Taken together, our data suggest that fasting activates the energy balance program in the OSOM of the kidney

Maternal Malaria Induces a Procoagulant and Antifibrinolytic State That Is Embryotoxic but Responsive to Anticoagulant Therapy

Low birth weight and fetal loss are commonly attributed to malaria in endemic areas, but the cellular and molecular mechanisms that underlie these poor birth outcomes are incompletely understood. Increasing evidence suggests that dysregulated hemostasis is important in malaria pathogenesis, but its role in placental malaria (PM), characterized by intervillous sequestration of Plasmodium falciparum, proinflammatory responses, and excessive fibrin deposition is not known. To address this question, markers of coagulation and fibrinolysis were assessed in placentae from malaria-exposed primigravid women. PM was associated with significantly elevated placental monocyte and proinflammatory marker levels, enhanced perivillous fibrin deposition, and increased markers of activated coagulation and suppressed fibrinolysis in placental plasma. Submicroscopic PM was not proinflammatory but tended to be procoagulant and antifibrinolytic. Birth weight trended downward in association with placental parasitemia and high fibrin score. To directly assess the importance of coagulation in malaria-induced compromise of pregnancy, Plasmodium chabaudi AS-infected pregnant C57BL/6 mice were treated with the anticoagulant, low molecular weight heparin. Treatment rescued pregnancy at midgestation, with substantially decreased rates of active abortion and reduced placental and embryonic hemorrhage and necrosis relative to untreated animals. Together, the results suggest that dysregulated hemostasis may represent a novel therapeutic target in malaria-compromised pregnancies

2016 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1003/thumbnail.jp

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio