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Journal of Gastrointestinal & Digestive System | ISSN: 2161-069X | Volume 8
Clinical Gastroenterology and Hepatology
14
th
International Conference on
August 29-30, 2018 | Toronto, Canada
Uncovering the role of planar cell polarity during intestinal morphogenesis
Abilasha Rao-Bhatia
1,2
, Sabrina Coquenlorge-Gallon, Wen-Chi Yin, Xiaoyun Zhang, Min Zhu, Chi-Chung Hui, Sevan Hopyan, Helen McNeill
1,3
and
Tae-
Hee Kim
1,2
1
The Hospital for Sick Children, Canada
2
University of Toronto, Canada
3
Washington University School of Medicine, USA
T
he mammalian intestine is lined with millions of finger-like projections, termed villi. These villi are critical for maximizing
nutrient absorption, digesting food and serving as a barrier from the harsh luminal environment. As such, compromised
villi can lead to serious diseases including malabsorption, short bowel syndrome, celiac, and others. Although villi are precisely
patterned by a network of signaling pathways during embryogenesis, it remains unclear as to how these signals translate
into distinct morphogenetic transformations. Previous studies attribute the formation of mesenchymal clusters distinguished
by Hedgehog (Hh) activation, as critical for epithelial rearrangement into villi. However, the mechanisms of Hh-mediated
clustering remain unknown. Our RNA-seq analyses coupled with
GLI2
(Hh-transcriptional activator) ChIP-seq reveal that
planar cell polarity (PCP) genes such as
Fat4, Dchs1
and
Vangl2
are putative direct targets of Hh in the gut mesenchyme.
Notably, mice deleted and/or mutated for these genes exhibit severe villus fusions and fail to form mesenchymal clusters,
demonstrating for the first time the importance of PCP in villification. Furthermore, genetic interaction studies reveal that the
core PCP axis (
Vangl2
) acts in parallel to the atypical cadherin axis (
Fat4, Dchs1
) in maintaining PCP. Additionally, ongoing
live-imaging of mutant villification
ex vivo
will uncover the types of mesenchymal cell behavior that is required for clustering
and subsequent villus formation. Together, we introduce Hh-activated stromal PCP as novel mechanisms required for the
morphogenetic events seen during villification.
Biography
Abilasha Rao-Bhatia is currently a PhD candidate under the supervision of Dr Tae-Hee Kim, Scientist at The Hospital for Sick Children and Assistant Professor of
the Molecular Genetics Department at the University of Toronto. She is part of an interdisciplinary team dedicated to understanding developmental and stem cell
biology of the gastrointestinal system. Prior to this, she completed her undergraduate studies at the University of Waterloo with a degree in Honour’s Biology Co-
operative studies. Her passion for biomedical research began here as a Co-op student in Dr John Dick’s laboratory studying the stem cell origins of acute myeloid
leukemia relapse.
abi.rao@mail.utoronto.caAbilasha Rao-Bhatia et al., J Gastrointest Dig Syst 2018, Volume 8
DOI: 10.4172/2161-069X-C6-079