Oxygen-sensitive Neuroepithelial Cells in the Gills of Aquatic Vertebrates

Dishevelled-Associating Protein with a high frequency of LEucines (DAPLE) belongs to a group of unconventional activators of heterotrimeric G-proteins that are cytoplasmic factors rather than membrane proteins of the G-protein–coupled receptor superfamily. During neurulation, DAPLE localizes to apical junctions of neuroepithelial cells and promotes apical cell constriction via G-protein activation. While junctional localization of DAPLE is necessary for this function, the factors it associates with at apical junctions or how they contribute to DAPLE-mediated apical constriction are unknown. MPDZ is a multi-PDZ (PSD95/DLG1/ZO-1) domain scaffold present at apical cell junctions whose mutation in humans is linked to nonsyndromic congenital hydrocephalus (NSCH). DAPLE contains a PDZ-binding motif (PBM) and is also mutated in human NSCH, so we investigated the functional relationship between both proteins. DAPLE colocalized with MPDZ at apical cell junctions and bound directly to the PDZ3 domain of MPDZ via its PBM. Much like DAPLE, MPDZ is induced during neurulation in Xenopus and is required for apical constriction of neuroepithelial cells and subsequent neural plate bending. MPDZ depletion also blunted DAPLE-mediated apical constriction of cultured cells. These results show that DAPLE and MPDZ, two factors genetically linked to NSCH, function as cooperative partners at apical junctions and are required for proper tissue remodeling during early stages of neurodevelopment.

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Engraftment of strictly anaerobic oxygen-sensitive bacteria in irritable bowel syndrome patients following fecal microbiota transplantation does not improve symptoms

Gut Microbes ◽

10.1080/19490976.2021.1927635 ◽

2021 ◽

Vol 13 (1) ◽

pp. 1-16

Author(s):

Patrick Denis Browne ◽

Frederik Cold ◽

Andreas Munk Petersen ◽

Sofie Ingdam Halkjær ◽

Alice Højer Christensen ◽

...

Keyword(s):

Irritable Bowel Syndrome ◽

Fecal Microbiota Transplantation ◽

Fecal Microbiota ◽

Strictly Anaerobic ◽

Oxygen Sensitive ◽

Irritable Bowel

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Single-cell atlas of early human brain development highlights heterogeneity of human neuroepithelial cells and early radial glia

Nature Neuroscience ◽

10.1038/s41593-020-00794-1 ◽

2021 ◽

Author(s):

Ugomma C. Eze ◽

Aparna Bhaduri ◽

Maximilian Haeussler ◽

Tomasz J. Nowakowski ◽

Arnold R. Kriegstein

Keyword(s):

Human Brain ◽

Brain Development ◽

Single Cell ◽

Radial Glia ◽

Cortical Development ◽

Cell Types ◽

Human Cortex ◽

Early Stages ◽

Human Brain Development ◽

Neuroepithelial Cells

AbstractThe human cortex comprises diverse cell types that emerge from an initially uniform neuroepithelium that gives rise to radial glia, the neural stem cells of the cortex. To characterize the earliest stages of human brain development, we performed single-cell RNA-sequencing across regions of the developing human brain, including the telencephalon, diencephalon, midbrain, hindbrain and cerebellum. We identify nine progenitor populations physically proximal to the telencephalon, suggesting more heterogeneity than previously described, including a highly prevalent mesenchymal-like population that disappears once neurogenesis begins. Comparison of human and mouse progenitor populations at corresponding stages identifies two progenitor clusters that are enriched in the early stages of human cortical development. We also find that organoid systems display low fidelity to neuroepithelial and early radial glia cell types, but improve as neurogenesis progresses. Overall, we provide a comprehensive molecular and spatial atlas of early stages of human brain and cortical development.

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Protection of Oxygen-Sensitive Enzymes by Peptide Hydrogel

ACS Nano ◽

10.1021/acsnano.0c09512 ◽

2021 ◽

Author(s):

Oren Ben-Zvi ◽

Itzhak Grinberg ◽

Asuka A. Orr ◽

Dror Noy ◽

Phanourios Tamamis ◽

...

Keyword(s):

Oxygen Sensitive ◽

Peptide Hydrogel

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Clostridium haemolyticum Infection: A Cause of Hemolytic Anemia in a Patient with Bone Marrow Necrosis

Microorganisms ◽

10.3390/microorganisms9081568 ◽

2021 ◽

Vol 9 (8) ◽

pp. 1568

Author(s):

Anne Sophie Lagneaux ◽

Sandrine Hénard ◽

Laure Diancourt ◽

Emmanuelle Stein ◽

Pierre Perez ◽

...

Keyword(s):

Bone Marrow ◽

Hemolytic Anemia ◽

Obese Woman ◽

Molecular Techniques ◽

Significant Past Medical History ◽

Bone Marrow Necrosis ◽

Rdna Sequencing ◽

Oxygen Sensitive ◽

Bacteremic Episode ◽

Bone Marrow Regeneration

Clostridium haemolyticum is a sporulating Gram-positive anaerobic rod that is considered to be one of the most fastidious and oxygen-sensitive anaerobes. It is a well-known animal pathogen and the cause of bacillary hemoglobinuria primarily in cattle. To date, human infections caused by C. haemolyticum have been reported in three patients with malignant underlying diseases. We present herein the case of a 30-year-old obese woman with no significant past medical history who developed bacteremia caused by C. haemolyticum with massive intravascular hemolysis associated with bone marrow necrosis and acute renal failure. Because of subculture failure, the diagnosis was made on the basis of 16S rDNA sequencing and next-generation sequencing. The patient, who had been afebrile for 20 days after a 17-day-course of antibiotics, experienced a second bacteremic episode caused by C. haemolyticum. After having been successfully treated for 42 days with clindamycin and amoxicillin-clavulanic acid, the patient developed acute myeloid leukemia as a result of bone marrow regeneration. Although uncommon in humans, infections caused by C. haemolyticum are severe and should be considered in a febrile patient who has severe hemolytic anemia. This case also highlights the importance of using molecular techniques for the identification of this fastidious anaerobic organism.

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