Biology subjects

Danzaki, K.

Publications and source records attributed to Danzaki, K..

3 recordsLinked to original sources

bioRxiv2026

The sympathetic nervous system initiates liver regeneration

Within hours of injury to the liver, signals from damaged hepatocytes activate Kupffer cells, inducing the production of inflammatory cytokines and proliferation of quiescent hepatocytes to regenerate the liver1,2. In humans, liver regenerative capacity declines with age3,4. However, the nature of the initial signals of liver regeneration and how they are affected during aging remain unclear. In this study, we leveraged "neuro-aging mice", in which neuronal function declines with age5, and discovered an essential role for intrahepatic sympathetic nerves in the early phase of liver regeneration. Upon liver injury in wild-type mice, there was a rapid, transient production of noradrenaline (NA) in the liver. This was abolished in neuro-aging mice who instead exhibited decreased metabolic capacity and fatal liver regeneration failure. NA coordinated the activity of multiple cell types by inducing expression of acute-response genes in hepatocytes and stimulating production of inflammatory cytokines such as IL-6 in Kupffer cells. These results identify a crucial role for the sympathetic nervous system and NA in liver regeneration. Further, they suggest that aging-related loss of this sympathetic nerve-NA regulatory axis reduces liver regenerative capacity.

physiology↗

bioRxiv2020

Dectin-1 limits central nervous system autoimmunity through a non-canonical pathway

Pathologic roles for innate immunity in neurologic disorders are well-described, but protective aspects of the immune response are less understood. Dectin-1, a C-type lectin receptor (CLR), is largely known to induce inflammation. However, we found that Dectin-1 is protective in experimental autoimmune encephalomyelitis (EAE), while its canonical signaling mediator, Card9, promotes the disease. Notably, Dectin-1 does not respond to heat-killed Mycobacteria, an adjuvant to induce EAE. Myeloid cells mediate the protective function of Dectin-1 in EAE and upregulate gene expression of neuroprotective molecules, including Oncostatin M (Osm) through a non-canonical Card9-independent pathway, mediated by NFAT. Furthermore, we found that the Osm receptor (OsmR) functions specifically in astrocytes to reduce EAE severity. Our study revealed a new mechanism of protective myeloid-astrocyte crosstalk regulated by a non-canonical Dectin-1 pathway and identifies novel therapeutic targets for CNS autoimmunity. Graphical AbstractO_LIDectin-1 is a protective C-type lectin receptor (CLR) in experimental autoimmune encephalomyelitis (EAE) C_LIO_LIDectin-1 promotes expression of Osm, a neuroprotective IL-6 family cytokine, in myeloid cells C_LIO_LIOsmR signaling in astrocytes limits EAE progression and promotes remission C_LIO_LINon-canonical Card9-independent signaling drives a distinct Dectin-1-mediated transcriptional program to induce expression of Osm and other factors with protective or anti-inflammatory functions C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=166 SRC="FIGDIR/small/080481v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@885aa2org.highwire.dtl.DTLVardef@1f68087org.highwire.dtl.DTLVardef@70263aorg.highwire.dtl.DTLVardef@ddc3b4_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2020

TGF-β inhibitor accelerates BMP4-induced cochlear gap junction formation during in vitro differentiation of embryonic stem cells

Mutations in the connexin 26 (CX26)/gap junction beta-2 (GJB2) gene are the most frequent cause of hereditary deafness worldwide. Using mouse induced pluripotent stem cells (iPSCs) and a BMP4 signal-based floating and adherent culture system, we recently produced in vitro responsible for GJB2-related deafness (CX26-gap junction plaque-forming cells, CX26GJCs). However, to use these cells as a disease model platform for high-throughput drug screening or regenerative therapy, cell yields must be substantially increased. In addition to BMP4, presently uncharacterized factors may also induce CX26 gap junction (GJ) formation. A floating culture with embryonic stem cell (ESC) treatment and BMP4/TGF-{beta} inhibitor (SB431542:SB) has been shown to result in greater production of isolatable CX26-positive small vesicles (CX26+ vesicles) and higher Gjb2 mRNA levels than BMP4 treatment alone, suggesting that SB may promote BMP4-mediated production of CX26+ vesicles in a dose-dependent manner, thereby increasing the yield of highly purified CX26GJCs. In the present study, we first demonstrated that SB accelerates BMP4 induced GJ formation during stem cell differentiation. By controlling the concentration and timing of SB supplementation with CX26+ vesicle purification, large-scale production of highly purified CX26GJCs suitable for high-throughput drug screening or regenerative therapy for GJB2-related deafness may be possible.

cell biology↗