Zika Virus Can Strongly Infect and Disrupt Secondary Organizers in the Ventricular Zone of the Embryonic Chicken Brain

Zika virus (ZIKV) is associated with severe neurodeve- lopmental impairments in human fetuses, including microencephaly. Previous reports examining neural progenitor tropism of ZIKV in organoid and animal models did not address whether the virus infects all neural progenitors uniformly. To explore this, ZIKV was injected into the neural tube of 2-day-old chicken embryos, resulting in nonuniform periventricular infec- tion 3 days later. Recurrent foci of intense infection were present at specific signaling centers that influ- ence neuroepithelial patterning at a distance through secretion of morphogens. ZIKV infection reduced transcript levels for 3 morphogens, SHH, BMP7, and FGF8 expressed at the midbrain basal plate, hypotha- lamic floor plate, and isthmus, respectively. Levels of Patched1, a SHH-pathway downstream gene, were also reduced, and a SHH-dependent cell popula- tion in the ventral midbrain was shifted in position. Thus, the diminishment of signaling centers through ZIKV-mediated apoptosis may yield broader, non- cell-autonomous changes in brain patterning

Chemical proteomics tracks virus entry and uncovers NCAM1 as Zika virus receptor

The mechanism underlying the cellular entry of Zika virus is not fully understood. Here, the authors use a chemically modified virus and time-resolved proteomics to capture interacting host proteins during virus entry and identify NCAM1 as a ZIKV receptor

Complementary use of mass spectrometry and cryo-electron microscopy to assess the maturity of live attenuated dengue vaccine viruses

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Characterization of the Proteome of Cytoplasmic Lipid Droplets in Mouse Enterocytes after a Dietary Fat Challenge

<div><p>Dietary fat absorption by the small intestine is a multistep process that regulates the uptake and delivery of essential nutrients and energy. One step of this process is the temporary storage of dietary fat in cytoplasmic lipid droplets (CLDs). The storage and mobilization of dietary fat is thought to be regulated by proteins that associate with the CLD; however, mechanistic details of this process are currently unknown. In this study we analyzed the proteome of CLDs isolated from enterocytes harvested from the small intestine of mice following a dietary fat challenge. In this analysis we identified 181 proteins associated with the CLD fraction, of which 37 are associated with known lipid related metabolic pathways. We confirmed the localization of several of these proteins on or around the CLD through confocal and electron microscopy, including perilipin 3, apolipoprotein A-IV, and acyl-CoA synthetase long-chain family member 5. The identification of the enterocyte CLD proteome provides new insight into potential regulators of CLD metabolism and the process of dietary fat absorption.</p></div

Isolated CLD fraction is enriched with CLD marker, Plin3, and has a high TAG to protein ratio.

<p>Enterocytes were isolated from the jejunum section of mouse small intestine, two hours after a 200 μl olive oil bolus. (A) Cells were lysed and fractionated using sucrose gradient ultracentrifugation. After freezing, the sample was cut into 7 fractions. (B) TAG/ protein ratio of isolated fractions. (C) Immunoblot analysis of the fractions with known markers of CLDs (Plin3), cytosol (Gapdh), and membranes (Cnx). (D) Negative staining transmission electron micrograph of fraction 1. Scale bar, 0.5 μm.</p

Immunofluoresence and immunoelectron imaging of Acsl5 demonstrates localization on or around CLDs.

<p>Representative confocal immunofluorescence images (n = 4 mice) and immunoelectron micrographs (n = 2 mice) of enterocytes two hours after a 200 μl olive oil bolus. Frozen sections were immunostained for Acsl5 (A). Lipids were stained with Bodipy (orange), nuclei stained with Dapi (blue), and the signals were merged. Bars = 5 μm (B). A 3D volume view was generated from Z-series images with the dimensions of 21.21 x 21.21 x 3.25 μm and indicates Acsl5 localizes to the area on or around the CLD (C). An immunoelectron micrograph of an enterocyte containing CLDs two hours post a 200 μl olive oil bolus with areas of interest highlighted by colored arrows. Scale bar = 1 μm. Colored arrows correspond with colored boxes of images E-H (D). CLDs are labeled with nanogold conjugated anti-Acsl5 antibody as indicated by the white arrows. Bars = 100 nm (E-G). Additionally, Acsl5 gold labeling was also observed in mitochondria. Bars = 100 nm (H).</p

A sub group of proteins are associated with known lipid related functions.

<p>Thirty seven proteins associated with known lipid metabolism pathways were identified, of which twenty three proteins have been previously identified in other CLD proteomic analyses. Relative levels of the proteins were determined by LFQ and the average is reported (n = 4 mice).</p><p>A sub group of proteins are associated with known lipid related functions.</p

Lipid accumulates in CLDs in enterocytes in response to a dietary fat challenge.

<p>Representative transmission electron micrograph of a mouse enterocyte from the jejunum section of the small intestine, two hours after an 200 μl olive oil bolus. Neutral lipids, stained with osmium tetroxide, accumulate in CLDs indicated by white asterisks. Golgi apparatus (white arrows) contain smaller chylomicron sized particles. White areas between enterocytes contain secreted chylomicrons (black cross). Scale bar, 1 μm.</p