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Pan, H.-Y.

Publications and source records attributed to Pan, H.-Y..

3 recordsLinked to original sources

Wntless interacts with Notch signaling to balance the generation of neurons and gliocytes in vertebrate dorsal diencephalon

Wnt chaperon Wntless (Wls) mediates the intracellular transport of Wnts and plays important roles in early vertebrate brain development. Spatially restricted induction of Wls denotes the earliest differentiation of non-telencephalic cells in human brain organoids. In zebrafish developing diencephalon, loss-of-Wls reduces the formation of habenula (HA) neurons but how Wls influences HA neurogenesis is unclear and whether Wls regulates gliocyte development is unknown. Here we report that the formations of cholinergic, substance P-ergic or glutamatergic neurons in HA are reduced differentially but the generation of gliocyte-derived choroid plexus (ChP) epithelia is increased in wls null mutants. At earlier stage, three-dimensional gene expression analyses revealed that while neurog1 expressions in HA progenitor zones are reduced, the expressions of Notch downstream effector her6 are increased and expanded into HA progenitor zones in wls mutants. Over-expressing Her6 in neurog1-positive cells reduced neurog1 expressions in HA progenitor zones. These results indicate that Wls restricts the expressions of Notch effector her6 to promote the specification of neurog1 proneurons and demotes the generation of ChP epithelia in zebrafish embryonic dorsal diencephalon.

developmental biology↗

Proteasomal Dysfunction results in ER stress, Endo MT, oxidative stress, and apoptotic cell death resulting in Fuchs Corneal Endothelial Dystrophy like features in mice

Fuchs Endothelial Corneal Dystrophy (FECD) is the irreversible degeneration of the corneal endothelium. The only treatment is corneal transplantation. To develop therapies for FECD, identifying the cellular causes for the onset and progression of the disease is crucial. While cell culture studies associate elevated oxidative stress, endoplasmic reticulum stress, endothelial-to-mesenchymal transition, and apoptosis with FECD, the causes behind the disease onset remain elusive. Guttae or Descemets membrane deposits are the earliest phenotype associated with FECD and are composed of unfolded proteins. Therefore, we asked if aberrant protein clearance pathways could be responsible for disease pathogenesis. We discovered a dysfunctional ubiquitin-proteasome pathway in a FECD mouse model and end-stage FECD patient samples. Inhibiting the ubiquitin-proteasome pathway in primary corneal endothelial cells resulted in the cellular dysfunctions associated with FECD. Finally, injecting healthy wild-type mice with proteasomal inhibitors resulted in all the major phenotypes associated with FECD, including corneal edema, guttae, and corneal endothelial cell loss. Therefore, this study strongly connects proteasomal dysfunction in FECD onset and progression.

cell biology↗

Three Dimensional Multi-gene Expression Maps Reveal Cell Fate Changes Associated with Laterality Reversal of Zebrafish Habenula

ABSTRACTThe conserved bilateral habenular nuclei (HA) in vertebrate diencephalon develop into compartmentalized structures containing neurons derived from different cell lineages. Despite extensive studies demonstrated that zebrafish larval HA display distinct left-right (L-R) asymmetry in gene expression and connectivity, the spatial gene expression domains were mainly obtained from two-dimensional (2D) snapshots of colorimetric RNA in situ hybridization staining which could not properly reflect different HA neuronal lineages constructed in three-dimension (3D). Combing the tyramide-based fluorescent mRNA in situ hybridization, confocal microscopy and customized imaging processing procedures, we have created spatial distribution maps of four genes for 4 day old zebrafish and in sibling fish whose L-R asymmetry was spontaneously reversed. 3D volumetric analyses showed that ratios of cpd2, lov, ron and nrp1a expression in L-R reversed HA were reversed according to the parapineal positions. However, the quantitative changes of gene expression in reversed larval brains do not mirror the gene expression level in the obverse larval brains. There were a total 87.78% increase of lov+nrp1a+ and a total 12.45% decrease of lov+ron+ double-positive neurons when the L-R asymmetry of HA was reversed. Thus, our volumetric analyses of the 3D maps indicate that changes of HA neuronal cell fates are associated with the reversal of HA laterality. These changes likely account for the behavior changes associated with HA laterality alterations.Competing Interest StatementThe authors have declared no competing interest.View Full Text

developmental biology↗