scholarly journals Cell-autonomous regulation of epithelial cell quiescence by calcium channel Trpv6

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yi Xin ◽  
Allison Malick ◽  
Meiqin Hu ◽  
Chengdong Liu ◽  
Heya Batah ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Human Colon ◽  
Quiescent State ◽  
Growth Factor Signaling ◽  
Quiescent Cells ◽  
Colon Carcinoma Cells ◽  
Epithelial Homeostasis ◽  
Cellular Quiescence

Epithelial homeostasis and regeneration require a pool of quiescent cells. How the quiescent cells are established and maintained is poorly understood. Here, we report that Trpv6, a cation channel responsible for epithelial Ca2+ absorption, functions as a key regulator of cellular quiescence. Genetic deletion and pharmacological blockade of Trpv6 promoted zebrafish epithelial cells to exit from quiescence and re-enter the cell cycle. Reintroducing Trpv6, but not its channel dead mutant, restored the quiescent state. Ca2+ imaging showed that Trpv6 is constitutively open in vivo. Mechanistically, Trpv6-mediated Ca2+ influx maintained the quiescent state by suppressing insulin-like growth factor (IGF)-mediated Akt-Tor and Erk signaling. In zebrafish epithelia and human colon carcinoma cells, Trpv6/TRPV6 elevated intracellular Ca2+ levels and activated PP2A, which down-regulated IGF signaling and promoted the quiescent state. Our findings suggest that Trpv6 mediates constitutive Ca2+ influx into epithelial cells to continuously suppress growth factor signaling and maintain the quiescent state.

scholarly journals Cell-autonomous regulation of epithelial cell quiescence by calcium channel Trpv6

2019 ◽  
Author(s):  
Yi Xin ◽  
Allison Malick ◽  
Meiqin Hu ◽  
Chengdong Liu ◽  
Heya Batah ◽  
...  
Keyword(s):  
Growth Factor ◽  
Epithelial Cells ◽  
Human Colon ◽  
Quiescent State ◽  
Growth Factor Signaling ◽  
Tor Signaling ◽  
Human Colon Cancer ◽  
Quiescent Cells ◽  
Intracellular Ca

AbstractEpithelial homeostasis and regeneration require a pool of quiescent cells. How the quiescent cells are established and maintained is poorly understood. Here we report that Trpv6, a cation channel responsible for epithelial Ca2+ absorption, functions as a key regulator of cellular quiescence. Genetic deletion and pharmacological blockade of Trpv6 promoted zebrafish epithelial cells to exit from quiescence and re-enter the cell cycle. Reintroducing Trpv6, but not its channel dead mutant, restored the quiescent state. Ca2+ imaging showed that Trpv6 is constitutively open in vivo. Mechanistically, Trpv6-mediated Ca2+ influx maintained the quiescent state by suppressing insulin-like growth factor (IGF)-mediated Akt and Tor signaling. In zebrafish epithelia and human colon cancer cells, Trpv6/TRPV6 elevated intracellular Ca2+ levels and activated PP2A, which down-regulated IGF signaling and promoted the quiescent state. Our findings suggest that Trpv6 mediates constitutive Ca2+ influx into epithelial cells to continuously suppress growth factor signaling and maintain the quiescent state.

scholarly journals A lysosomal dimmer switch regulates cellular quiescence depth

2018 ◽  
Author(s):  
Kotaro Fujimaki ◽  
Ruoyan Li ◽  
Hengyu Chen ◽  
Kimiko Della Croce ◽  
Hao Helen Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Expression Signature ◽  
Serum Starvation ◽  
Quiescent State ◽  
Cellular Mechanisms ◽  
Lysosomal Function ◽  
Quiescent Cells ◽  
Cellular Quiescence

ABSTRACTNumerous physiological and pathological phenomena are associated with the quiescent state of a cell. Cellular quiescence is a heterogeneous resting state; cells in deep than shallow quiescence require stronger growth stimulation to exit quiescence and reenter the cell cycle. Despite the importance of quiescent cells such as stem and progenitor cells to tissue homeostasis and repair, cellular mechanisms controlling the depth of cellular quiescence are poorly understood. Here we began by analyzing transcriptome changes as rat embryonic fibroblasts moved progressively deeper into quiescence under increasingly longer periods of serum starvation. We found that lysosomal gene expression was significantly upregulated in deep than shallow quiescence, which compensated for gradually reduced autophagy flux observed during quiescence deepening. Consistently, we show that inhibiting lysosomal function drove cells deeper into quiescence and eventually into a senescence-like irreversibly arrested state. By contrast, increasing lysosomal function progressively pushed cells into shallower quiescence. That is, lysosomal function modulates quiescence depth continuously like a dimmer switch. Mechanistically, we show that lysosomal function prevents quiescence deepening by reducing oxidative stress in the cell. Lastly, we show that a gene expression signature developed by comparing deep and shallow quiescent cells can correctly classify senescent and aging cells in a wide array of cell lines in vitro and tissues in vivo, suggesting that quiescence deepening, senescence, and aging may share common regulatory mechanisms.

scholarly journals Use of Native Lactococci as Vehicles for Delivery of DNA into Mammalian Epithelial Cells

2006 ◽  
Vol 72 (11) ◽  
pp. 7091-7097 ◽  
Author(s):  
Valéria Dellaretti Guimarães ◽  
Silvia Innocentin ◽  
François Lefèvre ◽  
Vasco Azevedo ◽  
Jean-Michel Wal ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mammalian Cells ◽  
Vaccination Strategy ◽  
Dna Delivery ◽  
Human Colon ◽  
Eukaryotic Expression ◽  
Delivery Vehicle ◽  
Colon Carcinoma Cells ◽  
Dna Delivery Vehicle

ABSTRACT The use of the food-grade bacterium Lactococcus lactis as a DNA delivery vehicle at the mucosal level is an attractive DNA vaccination strategy. Previous experiments showed that recombinant L. lactis expressing the Listeria monocytogenes inlA gene can deliver a functional gene into mammalian cells. Here, we explored the potential use of noninvasive L. lactis strains as a DNA delivery vehicle. We constructed two Escherichia coli-L. lactis shuttle plasmids, pLIG:BLG1 and pLIG:BLG2, containing a eukaryotic expression cassette with the cDNA of bovine β-lactoglobulin (BLG). The greatest BLG expression after transfection of Cos-7 cells was obtained with pLIG:BLG1, which was then used to transform L. lactis MG1363. The resulting L. lactis strain MG1363(pLIG:BLG1) was not able to express BLG. The potential of L. lactis as a DNA delivery vehicle was analyzed by detection of BLG in Caco-2 human colon carcinoma cells after 3 h of coincubation with (i) purified pLIG:BLG1, (ii) MG1363(pLIG:BLG1), (iii) a mix of MG1363(pLIG) and purified pLIG:BLG1, and (iv) MG1363. Both BLG cDNA and BLG expression were detected only in Caco-2 cells coincubated with MG1363(pLIG:BLG1). There was a decrease in the BLG cDNA level in Caco-2 cells between 24 and 48 h after coincubation. BLG expression by Caco-2 cells started at 24 h and increased between 24 and 72 h. BLG secretion by Caco-2 cells started 48 h after coincubation with MG1363(pLIG:BLG1). We conclude that lactococci can deliver BLG cDNA into mammalian epithelial cells, demonstrating their potential to deliver in vivo a DNA vaccine.

scholarly journals Dynamic changes of podocytes caused by fibroblast growth factor 2 in culture

2021 ◽  
Author(s):  
Eishin Yaoita ◽  
Masaaki Nameta ◽  
Yutaka Yoshida ◽  
Hidehiko Fujinaka
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor 2 ◽  
Quiescent State ◽  
Fibroblast Growth ◽  
Gene Expressions ◽  
Dynamic Changes ◽  
Ki 67

AbstractFibroblast growth factor 2 (FGF2) augments podocyte injury, which induces glomerulosclerosis, although the mechanisms remain obscure. In this study, we investigated the effects of FGF2 on cultured podocytes with interdigitating cell processes in rats. After 48 h incubation with FGF2 dynamic changes in the shape of primary processes and cell bodies of podocytes resulted in the loss of interdigitation, which was clearly shown by time-lapse photography. FGF2 reduced the gene expressions of constituents of the slit diaphragm, inflections of intercellular junctions positive for nephrin, and the width of the intercellular space. Immunostaining for the proliferation marker Ki-67 was rarely seen and weakly stained in the control without FGF2, whereas intensely stained cells were frequently found in the presence of FGF2. Binucleation and cell division were also observed, although no significant increase in cell number was shown. An in vitro scratch assay revealed that FGF2 enhanced migration of podocytes. These findings show that FGF2 makes podocytes to transition from the quiescent state into the cell cycle and change their morphology due to enhanced motility, and that the culture system in this study is useful for analyzing the pathological changes of podocytes in vivo.

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