Liu Lab

The University of Michigan School of Dentistry

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ABOUT

Research in our laboratory is focused on understanding cellular and molecular mechanisms that regulate physiological and pathological bone metabolism, skeletal and craniofacial bone development and diseases. In particular, we are interested in the following lines of research:

THE ROLES OF AUTOPHAGY IN SKELETAL AND CRANIOFACIAL BONE METABOLISM

Autophagy is a conserved lysosomal degradation process that has important roles in both normal human physiology and disease. However, the function of autophagy in skeletal and craniofacial bone homeostasis is not well understood. We found that autophagy is activated during osteoblast differentiation. Ablation of FIP200 (focal adhesion kinase family interacting protein of 200 kD), an essential component of mammalian autophagy, leads to multiple autophagic defects in osteoblasts. Osteoblast-specific deletion of FIP200 leads to osteopenia in mice. Our current effort is to determine the molecular mechanisms and signaling pathways by which autophagy regulates mesenchymal stem cell, craniofacial osteogenic stem cell and osteoblast function using a combination of molecular, cell biological and mouse genetic approaches.

THE REGULATION OF SKELETAL AND CRANIOFACIAL BONE DEVELOPMENT BY mTOR SIGNALING

Tuberous sclerosis (TS) is a genetic disorder characterized by the presence of benign congenital tumors in multiple organs and is caused by mutations in one of two genes, called TSC1 and TSC2. Tuberous sclerosing bone dysplasia is characterized by osteosclerotic changes in skeletal and craniofacial bones. In this disease, hyperactivity of mTOR (mammalian target of rapamycin) signaling is implicated. Despite the high frequency of osseous manifestation (>66%) in TSC patients, it is unknown to what extent and how mTOR signaling regulates bone metabolism in vivo. We established the first craniofacial sclerotic bone lesion mouse model of Tuberous sclerosis and found that enhanced mTOR signaling in neural crest-derived cells can increase bone mass through enlargement of the osteoprogenitor pool, which likely explains the sclerotic bone lesion observed in Tuberous sclerosis patients. We are currently using various genetic mouse models to elucidate the mechanisms by which mTOR signaling regulates skeletal and craniofacial bone development.

The regulation of bone development and health by FAK signaling

FAK (Focal adhesion kinase) is a major mediator of signal transduction by integrins. We recently demonstrated that FAK deletion in osteoblast progenitor cells leads to an osteopenia phenotype associated with increased bone marrow adiposity. The decreased bone mass in FAK-deficient mice is accounted for by decreased proliferation, compromised osteogenic differentiation, and increased adipogenic differentiation of bone marrow mesenchymal stromal/stem cells. Mechanistically, FAK deficiency leads to decreased Wnt/β-catenin signaling evidenced by lowered β-catenin protein levels and decreased mRNA expression of Wnt ligands and target genes. Our findings demonstrated that FAK plays an important role in bone mass acquisition and also identified a novel mechanism accountable for the negative correlation between bone mass and bone marrow adiposity. We are currently determining the function of FAK in mesenchymal stem cells and the impact of FAK inhibition on bone health.

DIRECTOR

fei liu

Fei Liu, DDS, PhD
Associate Professor
Associate Chair of Prosthodontics

feiliu@umich.edu | | 734-936-0911


EDUCATION AND TRAINING

BS/MS, Stomatology, West China University of Medical Sciences (Si Chuan University), Chengdu, China, 1996
DDS, West China University of Medical Sciences (Si Chuan University), Chengdu, China, 1999
PhD, Biomedical Science, University of Connecticut Health Center, Farmington, CT, 2006
Certificate in Prosthodontics, University of Connecticut Health Center, Farmington, CT, 2006
Post-doc, University of Michigan, Ann Arbor, MI, 2006-2009
Board certification, American Board of Prosthodontics, 2009
Board re-certification, American Board of Prosthodontics, 2017

SERVICES AT THE SCHOOL OF DENTISTRY

2012 - 2018 Member, Research Committee, University of Michigan School of Dentistry
2016 - present Member, PhD candidate Preliminary Exam Committee, University of Michigan School of Dentistry
2018 - present Chair, PhD admission Committee, Oral Health Science Program, University of Michigan School of Dentistry
2018 - present Member, Executive Committee, University of Michigan School of Dentistry

MEMBERSHIP AND SERVICE IN PROFESSIONAL ORGANIZATIONS

2004 - present Member, American Society for Bone and Mineral Research
2007 - present Member, American Academy of Fixed Prosthodontics
2008 - 2013 Member, Tylman Research Committee of American Academy of Fixed Prosthodontics
2009 - present Member, International Chinese Musculoskeletal Research Society (Lifetime member from 2017)
2010 - present Fellow, American College of Prosthodontists
2012 - present Member, Research Committee, American College of Prosthodontists
2012 - 2014 Chair, Scientific Research Committee of American Academy of Fixed Prosthodontics
2012 - present Member, American Association of Dental Research
2012 - 2015 Member, Constitution Committee, American Association of Dental Research
2012 - present Member, International Association of Dental Research
2013 - 2018 Chair, Tylman Research Committee of American Academy of Fixed Prosthodontics
2017 - 2020 Board Director, American Academy of Fixed Prosthodontics
2018 - present Member, program committee, International Chinese Musculoskeletal Research Society
2020 - present Member, American Dental Education Association

HONORS

1997 First place of Xuan Rui Ling dental graduate student scholarship, West China University of Medical Sciences (Si Chuan University)
1998 First place of DENTSPLY dental graduate student scholarship, West China University of Medical Sciences (Si Chuan University)
2004 Young Investigator Award, Advances in Skeletal Anabolic Agents for the Treatment of Osteoporosis (American Society for Bone and Mineral Research)
2004 ASBMR Young Investigator Award from American Society for Bone and Mineral Research
2004 First place of Remo Sinibaldi Memorial Table Clinic Competition, American College of Prosthodontics
2009 Diplomate, American Board of Prosthodontics

AWARDS TO TRAINEES

2013

Travel Award from American Society for Bone and Mineral Research to Dr. Fang Fang (post-doc fellow)

2015

Travel Award from American Society for Bone and Mineral Research to Dr. Li Wang (post-doc fellow)

2016

1. ASBMR Young Investigator Award from American Society for Bone and Mineral Research to Dr. Xiaoxi Wei (PhD student)

2. Plenary oral presentation and ASBMR Young Investigator Award from American Society for Bone and Mineral Research to Dr. Chunhui Sun (visiting scholar)

2017

1. AADR student research fellowship to Neil Thomas (DDS candidate)

2. Travel Award from American Society for Bone and Mineral Research to Dr. Han Kyoung Choi (post-doc fellow)

2018

1. Janice E. Berry Prize for Excellence in Research to Dr. Xiaoxi Wei (visiting scientist)

2. 2nd place in Basic Science Research, University of Michigan School of Dentistry Annual Research Day to Dr. Yuanlynn Hsieh (MS student)

3. Travel Award at second annual musculoskeletal symposium from Michigan Integrative Musculoskeletal Health Core Center to Dr. Jinfeng Yao (visiting scholar)

2019

1. 1st place in Basic Science Research, University of Michigan School of Dentistry Annual Research Day to Dr. Yuanlynn Hsieh (MS student)

2. 1st place in Visiting Scholar Research to Dr. Xiaoxi Wei at University of Michigan School of Dentistry Annual Research Day (visiting scholar)

3. 2nd place in Visiting Scholar Research to Dr. Bei Yin at University of Michigan School of Dentistry Annual Research Day (visiting scholar)

4. 3rd place in Visiting Scholar Research to Dr. Shuqun Qi at University of Michigan School of Dentistry Annual Research Day (visiting scholar in Dr. Liu’s lab)

5. 3rd place in basic science research at University of Michigan School of Dentistry Annual Research Day to Dr. Han Kyoung Choi (research fellow)

6. Delta dental fellowship award to 2019 dental student graduates at University of Michigan School of Dentistry to Neil Thomas (DDS research pathway student)

7. Young Investigator Travel Award from American Society for Bone and Mineral Research to Shuqun Qi (PhD student)

8. Young Investigator Travel Award from American Society for Bone and Mineral Research to Dr. Han Kyoung Choi (post-doc fellow)

2020

1. 2nd place in Basic Science Research, University of Michigan School of Dentistry Annual Research Day to Di Xie (U of M undergraduate student, 2024 DDS class)

2. 2nd place in Visiting Scholar Research to Dr. Shuqun Qi at University of Michigan School of Dentistry Annual Research Day (visiting PhD student)

3. 3rd place in Visiting Scholar Research to Dr. Yating Wang at University of Michigan School of Dentistry Annual Research Day (visiting scholar)

4. ASBMR Young Investigator Award from American Society for Bone and Mineral Research to Shuqun Qi (PhD student)

Publications


View the complete listing of publications.

TEAM

han kyoung choi

Han Kyoung Choi, PhD
Research Associate

choihan@umich.edu

shuqun qi

Shuqun Qi, BDS, MS, PhD
Research Fellow

shqi@umich.edu

daniela mendonca

Daniela Mendonça, DDS, MSc, PhD
Clinical Assistant Professor

mendonca@umich.edu

thomas kim

Thomas Kim, BS
DDS candidate, Research Pathways Student

sungyeob@umich.edu

yating wang

Yating Wang, DDS, PhD
Visiting Scholar

wyating@umich.edu

iya ghassib

Iya Ghassib, DDS
Visiting Scholar

ighassib@umich.edu

di xie

Di Xie
Student

xiedi@umich.edu

CONTACT

Liu Lab
University of Michigan School of Dentistry
1011 N University Ave,
Ann Arbor, MI 48109
Lab room: 4214, 4228
Office room: 4205
Lab phone: 734-763-8532
Office phone: 734-936-0911
Email: feiliu@umich.edu