Naslov
Modulation of Notch signalling pathway in activated hepatic stellate cells has no influence on development or resolution of hepatic fibrosis

Autori
Šisl, Dino ; Novak, Sanja ; Kalajzić, Ivo ; Filipović, Maša ; Flegar, Darja ; Šućur, Alan ; Kovačić, Nataša ; Grčević, Danka ; Kelava, Tomislav

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
5th Meeting of Middle Europe Societies of Immunology and Allergology

Mjesto i datum
Prag, Češka Republika, 23.11.2022. - 26.11.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
liver fibrosis, Notch signaling pathway, mouse model, gene expression

Sažetak
We used transgenic mice to investigate the effect selective Notch inhibition or forced activation in activated hepatic stellate cells (aHSCs) has on liver fibrosis. We used two models, carbon tetrachloride (CCl4) treatment and DDC- supplemented diet. The effect of Notch inhibition was investigated in SMACreERT2+/-/RBP- Jfl/fl mice, while Notch activation was studied using SMACreERT2+/- /RosaNICD1 mice. Mice were treated with 75μg/g of tamoxifen i.p. twice weekly. Identically treated Cre- littermates served as controls. CCl4 and DDC caused a similar degree of fibrosis (Sirius red stained area, hydroxyproline content, aminotransferase activities, gene expression of Col1a1 and Acta2) in experimental and control groups in Notch-inhibition as well as Notch-activation experiments. We further tested whether forced Notch activation in aHSCs delays resolution of fibrosis. SMACreERT2+/-/RosaNICD1 mice were treated with either CCl4 or DDC, and tamoxifen for 10 days, and then recovered for one month. Recovery was similar in both SMACreERT2+/-/RosaNICD1 and SMACreERT2-/-/RosaNICD1 mice, suggesting that forced Notch activation doesn’t impair recovery. We also found that tamoxifen per se protects against DDC- induced fibrosis. This was evidenced by a lower Sirius red-stained area, lower hydroxyproline content, and further confirmed by qPCR showing a lower expression of genes for Col1a1, Acta2, Sox9, Pdgf, and Krt19, indicating the inhibitory effect on HSCs, collagen production, and biliary duct proliferation. This effect highlights the importance of a proper Cre- littermate control in this investigation. We conclude that modulation of Notch activity in aHSCs neither changes the degree of liver fibrosis nor does it impair recovery once the noxious stimulus is withdrawn.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA