# The Role of Portal Fibroblasts in Cholestatic Liver Fibrosis

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2021 · $486,640

## Abstract

ABSTRACT: Cholestatic fibrosis is the outcome of chronic liver diseases, including primary sclerosing
cholangitis (PSC), primary biliary cirrhosis (PBC), secondary biliary cirrhosis (SBC). It is characterized by
extensive deposition of extracellular matrix (ECM), including collagen Type I. Activated hepatic stellate cells
(aHSCs) and portal fibroblasts (aPFs) are the major source of the fibrous scar in the liver. aPFs have been
implicated in liver fibrosis caused by cholestatic liver injury. (AIM1) Here we propose to study the role of Msln-
Muc16-Thy-1 signaling in the pathogenesis of cholestatic fibrosis in Mdr2-/- mice. For this purpose, Mdr2-/- mice
are crossed to Msln-/- mice, Muc16-/- mice, or Thy-1-/- mice. To dissect the relationship between Msln-Muc16-
Thy-1, we generated Mdr2-/- mice devoid of both Msln and Muc16 (triple knockout Mdr2-/-Msln-/-Muc16-/- mice)
or Msln and Thy-1 (Mdr2-/-Msln-/-Thy-1-/- mice). The time course comparison of cholestatic fibrosis in Mdr2-/- and
BDL-injured mice will reveal similarities of aPF activation in both models. The paracrine signaling between
aPFs and cholangiocytes will be evaluated. (AIM2) We will investigate the unique mechanisms, common
mediators, and molecular factors that mediate activation of aPFs. We hypothesize that Msln induces a non-
canonical TGFb/TGFbRI-Smad2/3/4-activation of aPFs. Additional potential pathways of Msln signaling in aPFs
(such as FGFR-Msln-Akt/ERK and JAK2/STAT3) will also be evaluated. To dissect the mechanism by which
Msln-Thy-1 pathway regulates aPF functions, Col-GFP+Thy-1+Msln+ aPFs will be sort purified, and analyzed by
RNA-Seq and mass spectrometry. To elucidate novel signaling pathways, gene expression profiles and binding
partners of WT and KO aPFs will be compared. (AIM3) To translate our findings from mice to humans, the role
of human MSLN-THY-1 will be studied in human aPFs in vitro and in vivo. We have already isolated and
characterized human aPFs from 6 livers of patients with cholestasis. Human aPFs are identified by expression
of the “signature genes” MSLN, CA125, THY-1, BNC1, UPK1β, CALCA, GPC3. 2 selected human aPF cell
lines will be analyzed using shRNA-knockdown ± TGFb1, and RNA-Seq. Binding partners of human MSLN will
be identified by mass spectrometry using anti-human MSLN Ab. (AIM4) Our central hypothesis is that MSLN-
MUC16-THY-1 pathway plays an important role in activation of human aPFs in response to cholestatic injury,
and therefore serves as a target for anti-fibrotic therapy. We will test if ablation of MSLN with anti-MSLN Ab-
immunotoxins can suppress development of cholestatic fibrosis in “humanized” MSLN mice (in which mouse
msln gene was replaced with human MSLN gene) or liver xenograft Rag2-/-gc-/- mice (generated by adoptive
transplantation of GFP-labeled human MSLN+ aPFs into the livers of Rag2-/-gc-/- mice, this technique is
developed in our laboratory). Effectiveness of immunotherapy will be estimated in these mice by disappearance
of ...

## Key facts

- **NIH application ID:** 10312314
- **Project number:** 2R01DK101737-05A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Tatiana Kisseleva
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $486,640
- **Award type:** 2
- **Project period:** 2014-09-15 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10312314

## Citation

> US National Institutes of Health, RePORTER application 10312314, The Role of Portal Fibroblasts in Cholestatic Liver Fibrosis (2R01DK101737-05A1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10312314. Licensed CC0.

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