Voxel-wise comparisons of cellular microstructure and diffusion-MRI in mouse hippocampus using 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND)

A key challenge in medical imaging is determining a precise correspondence between image properties and tissue microstructure. This comparison is hindered by disparate scales and resolutions between medical imaging and histology. We present a new technique, 3D Bridging of Optically-clear histology with Neuroimaging Data (3D-BOND), for registering medical images with 3D histology to overcome these limitations. Ex vivo 120 × 120 × 200 μm resolution diffusion-MRI (dMRI) data was acquired at 7 T from adult C57Bl/6 mouse hippocampus. Tissue was then optically cleared using CLARITY and stained with cellular markers and confocal microscopy used to produce high-resolution images of the 3D-tissue microstructure. For each sample, a dense array of hippocampal landmarks was used to drive registration between upsampled dMRI data and the corresponding confocal images. The cell population in each MRI voxel was determined within hippocampal subregions and compared to MRI-derived metrics. 3D-BOND provided robust voxel-wise, cellular correlates of dMRI data. CA1 pyramidal and dentate gyrus granular layers had significantly different mean diffusivity (p > 0.001), which was related to microstructural features. Overall, mean and radial diffusivity correlated with cell and axon density and fractional anisotropy with astrocyte density, while apparent fibre density correlated negatively with axon density. Astrocytes, axons and blood vessels correlated to tensor orientation

HIF-1 and SKN-1 Coordinate the Transcriptional Response to Hydrogen Sulfide in Caenorhabditis elegans

Hydrogen sulfide (H2S) has dramatic physiological effects on animals that are associated with improved survival. C. elegans grown in H2S are long-lived and thermotolerant. To identify mechanisms by which adaptation to H2S effects physiological functions, we have measured transcriptional responses to H2S exposure. Using microarray analysis we observe rapid changes in the abundance of specific mRNAs. The number and magnitude of transcriptional changes increased with the duration of H2S exposure. Functional annotation suggests that genes associated with protein homeostasis are upregulated upon prolonged exposure to H2S. Previous work has shown that the hypoxia-inducible transcription factor, HIF-1, is required for survival in H2S. In fact, we show that hif-1 is required for most, if not all, early transcriptional changes in H2S. Moreover, our data demonstrate that SKN-1, the C. elegans homologue of NRF2, also contributes to H2S-dependent changes in transcription. We show that these results are functionally important, as skn-1 is essential to survive exposure to H2S. Our results suggest a model in which HIF-1 and SKN-1 coordinate a broad transcriptional response to H2S that culminates in a global reorganization of protein homeostasis networks

Demonstration of Binding of Neuronal Calcium Sensor-1 to the Ca(v)2.1 P/Q-Type Calcium Channel

[Image: see text] In neurons, entry of extracellular calcium (Ca(2+)) into synaptic terminals through Ca(v)2.1 (P/Q-type) Ca(2+) channels is the driving force for exocytosis of neurotransmitter-containing synaptic vesicles. This class of Ca(2+) channel is, therefore, pivotal during normal neurotransmission in higher organisms. In response to channel opening and Ca(2+) influx, specific Ca(2+)-binding proteins associate with cytoplasmic regulatory domains of the P/Q channel to modulate subsequent channel opening. Channel modulation in this way influences synaptic plasticity with consequences for higher-level processes such as learning and memory acquisition. The ubiquitous Ca(2+)-sensing protein calmodulin (CaM) regulates the activity of all types of mammalian voltage-gated Ca(2+) channels, including the P/Q class, by direct binding to specific regulatory motifs. More recently, experimental evidence has highlighted a role for additional Ca(2+)-binding proteins, particularly of the CaBP and NCS families in the regulation of P/Q channels. NCS-1 is a protein found from yeast to humans and that regulates a diverse number of cellular functions. Physiological and genetic evidence indicates that NCS-1 regulates P/Q channel activity, including calcium-dependent facilitation, although a direct physical association between the proteins has yet to be demonstrated. In this study, we aimed to determine if there is a direct interaction between NCS-1 and the C-terminal cytoplasmic tail of the Ca(v)2.1 α-subunit. Using distinct but complementary approaches, including in vitro binding of bacterially expressed recombinant proteins, fluorescence spectrophotometry, isothermal titration calorimetry, nuclear magnetic resonance, and expression of fluorescently tagged proteins in mammalian cells, we show direct binding and demonstrate that CaM can compete for it. We speculate about how NCS-1/Ca(v)2.1 association might add to the complexity of calcium channel regulation mediated by other known calcium-sensing proteins and how this might help to fine-tune neurotransmission in the mammalian central nervous system

Core shell lipid-polymer hybrid nanoparticles with combined docetaxel and molecular targeted therapy for the treatment of metastatic prostate cancer

Many prostate cancers relapse after initial chemotherapy treatment. Combining molecular and chemotherapy together with encapsulation of drugs in nanocarriers provides effective drug delivery and toxicity reduction. We developed core shell lipid-polymer hybrid nanoparticles (CSLPHNPs) with poly (lactic-co-glycolic acid) (PLGA) core and lipid layer containing docetaxel and clinically used inhibitor of sphingosine kinase 1 (SK1) FTY720 (fingolimod). We show for the first time that FTY720 (both free and in CSLPHNPs) re-sensitizes castrate resistant prostate cancer cells and tumors to docetaxel, allowing a four-fold reduction in effective dose. Our CSLPHNPs showed high serum stability and a long shelf life. CSLPHNPs demonstrated a steady uptake by tumor cells, sustained intracellular drug release and in vitro efficacy superior to free therapies. In a mouse model of human prostate cancer, CSLPHNPs showed excellent tumor targeting and significantly lower side effects compared to free drugs, importantly, reversing lymphopenia induced by FTY720. Overall, we demonstrate that nanoparticle encapsulation can improve targeting, provide low off-target toxicity and most importantly reduce FTY720-induced lymphopenia, suggesting its potential use in clinical cancer treatment

Complement is activated in progressive multiple sclerosis cortical grey matter lesions

The symptoms of multiple sclerosis (MS) are caused by damage to myelin and nerve cells in the brain and spinal cord. Inflammation is tightly linked with neurodegeneration, and it is the accumulation of neurodegeneration that underlies increasing neurological disability in progressive MS. Determining pathological mechanisms at play in MS grey matter is therefore a key to our understanding of disease progression

Directional control of weakly localized Raman from a random network of fractal nanowires

Disordered optical media are an emerging class of materials capable of strongly scattering light. Their study is relevant to investigate transport phenomena and for applications in imaging, sensing and energy storage. While such materials can be used to generate coherent light, their directional emission is typically hampered by their very multiple scattering nature. Here, we tune the out-of-plane directionality of coherent Raman light scattered by a fractal network of silicon nanowires. By visualizing Rayleigh scattering, photoluminescence and weakly localized Raman light from the random network of nanowires via real-space microscopy and Fourier imaging, we gain insight on the light transport mechanisms responsible for the material's inelastic coherent signal and for its directionality. The possibility of visualizing and manipulating directional coherent light in such networks of nanowires opens venues for fundamental studies of light propagation in disordered media as well as for the development of next generation optical devices based on disordered structures, inclusive of sensors, light sources and optical switches

Promised Land? Immigration, Religiosity, and Space in Southern California

This article looks at how immigrants and their supporters appropriate and use religious space and other public spaces for religious and socio-political purposes in Southern California. While the everyday living conditions of many immigrants, particularly the unauthorized Latino immigrants, force unto them an embodied disciplinarity that maintains spatialities of restricted citizenship, the public appropriations of space for and through religious practices allow for them -even if only momentarily -to express an embodied transgression. This practice in public space helps realize spaces of freedom and hope, however ephemerally. Potentially, these rehearsing exercises can help revert internalized disempowering subjectivities and create social empowerment. Negative stereotypes about immigrants held by the larger public can also be challenged through these spatial practices, as the public demonstrations make visible the invisible. We focus on “Posadas Without Borders” and “the New Sanctuary Movement,” considering both the role of progressive civic and religious institutions in supporting immigrants and the agency of the immigrants themselves. The theoretical analysis builds on concepts drawn from a conversation between geography and religious and theological studies. We use a triangulated methodological approach that includes observation and participant observation, content-analysis of multimedia, interviews, and intellectual advocacy for the immigrant movement. The cases discussed here show that progressive religious groups and coalitions can be important allies to progressive planners, geographers, and policy makers in advancing social and environmental justice for the disenfranchised. They also show that the theological underpinnings of such groups share a lot in common with planning epistemologies for the just city

Characterization of an extracellular lipase and its chaperone from Ralstonia eutropha H16

Lipase enzymes catalyze the reversible hydrolysis of triacylglycerol to fatty acids and glycerol at the lipid–water interface. The metabolically versatile Ralstonia eutropha strain H16 is capable of utilizing various molecules containing long carbon chains such as plant oil, organic acids, or Tween as its sole carbon source for growth. Global gene expression analysis revealed an upregulation of two putative lipase genes during growth on trioleate. Through analysis of growth and activity using strains with gene deletions and complementations, the extracellular lipase (encoded by the lipA gene, locus tag H16_A1322) and lipase-specific chaperone (encoded by the lipB gene, locus tag H16_A1323) produced by R. eutropha H16 was identified. Increase in gene dosage of lipA not only resulted in an increase of the extracellular lipase activity, but also reduced the lag phase during growth on palm oil. LipA is a non-specific lipase that can completely hydrolyze triacylglycerol into its corresponding free fatty acids and glycerol. Although LipA is active over a temperature range from 10 °C to 70 °C, it exhibited optimal activity at 50 °C. While R. eutropha H16 prefers a growth pH of 6.8, its extracellular lipase LipA is most active between pH 7 and 8. Cofactors are not required for lipase activity; however, EDTA and EGTA inhibited LipA activity by 83 %. Metal ions Mg[superscript 2+], Ca[superscript 2+], and Mn[superscript 2+] were found to stimulate LipA activity and relieve chelator inhibition. Certain detergents are found to improve solubility of the lipid substrate or increase lipase-lipid aggregation, as a result SDS and Triton X-100 were able to increase lipase activity by 20 % to 500 %. R. eutropha extracellular LipA activity can be hyper-increased, making the overexpression strain a potential candidate for commercial lipase production or in fermentations using plant oils as the sole carbon source.Malaysia-MIT Biotechnology Partnership Programm

A Toxin–Antitoxin System Promotes the Maintenance of an Integrative Conjugative Element

SXT is an integrative and conjugative element (ICE) that confers resistance to multiple antibiotics upon many clinical isolates of Vibrio cholerae. In most cells, this ∼100 Kb element is integrated into the host genome in a site-specific fashion; however, SXT can excise to form an extrachromosomal circle that is thought to be the substrate for conjugative transfer. Daughter cells lacking SXT can theoretically arise if cell division occurs prior to the element's reintegration. Even though ∼2% of SXT-bearing cells contain the excised form of the ICE, cells that have lost the element have not been detected. Here, using a positive selection-based system, SXT loss was detected rarely at a frequency of ∼1×10−7. As expected, excision appears necessary for loss, and factors influencing the frequency of excision altered the frequency of SXT loss. We screened the entire 100 kb SXT genome and identified two genes within SXT, now designated mosA and mosT (for maintenance of SXT Antitoxin and Toxin), that promote SXT stability. These two genes, which lack similarity to any previously characterized genes, encode a novel toxin-antitoxin pair; expression of mosT greatly impaired cell growth and mosA expression ameliorated MosT toxicity. Factors that promote SXT excision upregulate mosAT expression. Thus, when the element is extrachromosomal and vulnerable to loss, SXT activates a TA module to minimize the formation of SXT-free cells

Characterisation of age and polarity at onset in bipolar disorder

Background Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools. Aims To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics. Method Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts. Results Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO. Conclusions AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses