Principal Investigator - Assistant Professor

Tom was born and raised in Berlin, Germany where he studied Medical Biotechnology at the Technical University Berlin while also earning a MSc in Bioengineering from Dongseo University in Busan, South Korea. He received his PhD in 2017 from the University of Potsdam in Germany elucidating the cellular and developmental origin of bone marrow adipose tissue as well as its implication for regenerative processes in the laboratory of Dr. Tim Schulz at the German Institute for Human Nutrition. Supported by a 2-year scholarship from the German Research Foundation, Tom conducted his postdoctoral work in the lab of Dr. Charles Chan at Stanford University co-mentored by Drs. Michael Longaker and Irv Weissman. There he developed a research program focusing on skeletal stem cell (SSC) biology in diverse contexts.

         Tom started his lab in the Department of Orthopaedic Surgery at UC Davis in January of 2023. His transition has been supported by an NIH/NIA K99/R00 Early Investigator Award. His lab's broad focus on SSC biology covers developmental bone biology, aging processes and various types of diseases, including osteoporosis, osteoarthritis and osteosarcoma. As part of his research mission he is dedicated to develop cutting-edge stem cell-centric approaches that overcome inherent shortcomings of the field. Tom has received multiple awards for his research which has also led him to co-found startups that drive translational efforts based on findings in his lab.

         Outside the lab, Tom enjoys traveling and exploring the outdoors with his wife and three kids. He also spends his free time watching sports, playing football (soccer) and obsessing over his lawn.

Postdoc

Kun obtained his M.D. and Ph.D. degrees from Tongji Medical College, Huazhong University of Science and Technology. During his doctoral training, he was selected for a joint Ph.D. program at Harvard School of Dental Medicine under the mentorship of Professor Roland Baron, where he received comprehensive training in fundamental bone biology and acquired essential experimental skills. His research during this period uncovered how the Wnt inhibitor SFRP4 regulates cortical bone remodeling and the function of periosteal skeletal stem cells (SSCs).

          After completing his Ph.D., Kun returned to China and served as an orthopedic surgeon for four years. This clinical experience deepened his understanding of the challenges posed by age-related skeletal conditions, including osteoporosis and non-healing fractures. Motivated to bridge basic science with clinical application, he joined Dr. Thomas Ambrosi’s laboratory at UC Davis to advance his research on SSC-based regenerative strategies.

          Kun’s current research focuses on elucidating the molecular mechanisms that govern skeletal stem cell aging and contribute to bone degeneration. He integrates state-of-the-art spatial transcriptomics and single-cell RNA sequencing technologies with foundational molecular and cellular approaches to investigate how site-specific cues and age-related factors influence SSC function. His long-term objective is to translate these biological insights into the development of innovative stem cell-based therapies for the treatment of age-associated skeletal diseases.
 

Postdoc

Yuting received her M.D. and Ph.D. degrees from Tongji Medical College, Huazhong University of Science and Technology. During her doctoral training, she joined the laboratory of Professor Charles K.F. Chan at Stanford University, where she gained extensive experience in skeletal stem cell biology and advanced experimental techniques. Her research led to the development of TESSERACT, a 3D single-cell spatial transcriptomic platform applied to live cells, designed to map the in situ architecture of the skeletal stem cell niche. Using this tool, she investigated whether tissues such as cartilage—traditionally considered to have poor regenerative potential—could be stimulated to regenerate under defined environmental conditions.
          Yuting joined the Ambrosi laboratory at UC Davis in 2024 to further her research on skeletal stem cell (SSC)-based regenerative therapies. Her current work focuses on uncovering the molecular and microenvironmental cues that regulate SSC activation and contribute to cartilage degeneration. By integrating TESSERACT with core genetic and cellular techniques, she seeks to identify SSC populations specific to regeneration and uncover key niche-derived signals essential for hyaline cartilage regeneration.
    Yuting’s long-term goal is to translate these fundamental discoveries into next-generation stem cell therapies that restore cartilage with the full anatomical and functional complexity of native tissue.
 

MD/PhD student

Kelly is a graduate student in the dual degree (MD/PhD) Program within the Graduate Group of Immunology at UC Davis. She received her undergraduate degree in Biochemistry and Chemistry from UC San Diego, where she competed on the UCSD NCAA Women’s Track and Field team as a sprinter and interned in Dr. Pieter Dorrestein’s analytical chemistry lab, conducting untargeted metabolomics projects on a multitude of subjects. After graduating, she continued to work within the Dorrestein lab, seeking to understand the implications of gut metabolites on human health.
          In 2021, Kelly joined the MD/PhD Program at UC Davis. She has completed the first two years of medical education and transitioned to the PhD portion of her degrees, joining the Graduate Group in Immunology and the Ambrosi Lab in 2023. Since joining the Ambrosi Lab, she has sought to combine her gut microbiome knowledge with musculoskeletal health research. Her main project seeks to establish a comprehensive understanding of how age-related shifts in the gut microbiome drive systemic changes that ultimately affect bone health and skeletal stem cells (SSCs). Specifically, she aims to understand the gut microbiome’s influence over the stem cell-mediated processes governing skeletogenesis and hematopoiesis. After finishing her PhD, Kelly will return to complete the final two clinical years of medical school and then enter an orthopedic surgery residency. Her long-term objective is to become an independent physician-scientist studying interorgan crosstalk crucial for the signaling processes within the musculoskeletal system at the stem cell level.
         In her free time, Kelly is an avid lover of the outdoors (she tries to average three trips to Yosemite a year!), enjoys running, hiking, camping, and spending time with her Australian Shepherd, Oliver.
 

PhD student

David Morales is currently a Ph.D. student in the Integrative Pathobiology Graduate Group at UC Davis. He earned his Bachelor of Science in Biochemistry from Humboldt State University in 2021. Following his undergraduate studies, David participated in a California Institute for Regenerative Medicine (CIRM) internship in the Fernando Fierro Lab at the UC Davis Institute for Regenerative Cures. This internship evolved into a role as a Junior Specialist, significantly contributing to his deep interest in stem cell biology and paving the way for his entrance into graduate school and the Ambrosi Lab.
      David's research primarily investigates the mechanisms of glucocorticoid (GC)-induced bone loss, with a specific focus on the skeletal stem cell (SSC) populations. His work identified Basigin as a critical factor in this pathology, and he actively explores  treatments targeting Basigin to prevent GC-induced skeletal deterioration. Given the similarities between GC effects and aging phenotypes, his research also aims to contribute broadly to the understanding of age-related mechanisms.

          Driven by his experiences as a first-generation college student and being raised by a single mother, David is passionate about mentoring, teaching, and science communication. He aims to become a professor and science communicator, with a strong commitment to bringing science education and outreach to underrepresented communities. With a mission to connect to his Indigenous roots, David also actively studies and integrates Indigenous American knowledge into his professional and daily practices, emphasizing environmental responsibility and sustainable living.
         Outside the lab, David is an avid boxer and maintains a fascinating collection of arachnids, including tarantulas and a scorpion, showcasing his enthusiasm for diverse forms of life.
 

Med student researcher, former research specialist

Ethan is currently a medical student researcher in the Ambrosi Lab. Ethan graduated from UC Davis in 2023 with a BS in Genetics & Genomics and a BA in Spanish. As an undergrad, he worked briefly in Dr. Christoph Vogel's lab, investigating the role of the aryl hydrocarbon receptor in aberrant immune system responses. where he contributes to a variety of research activities.

         Since joining the Ambrosi Lab in December 2023, Ethan's research has focused on the osteogenic potential of small molecules, and the complex relationship between skeletal health, high fat diet, and the osteoanabolic factor CCN3. His work involves maintaining both human and murine stem cell cultures, performing endpoint characterization for long-term mouse experiments, managing flow cytometer operations, and analyzing micro-computed tomography scans. He's also involved in histology staining and quantification, alongside his contributions to specific research projects within the lab.
        Driven by his own childhood experiences with clubfoot and a limb length discrepancy, Ethan’s goal is to attend medical school and ultimately become an orthopaedic surgeon, contributing to the field of limb lengthening through the development of innovative stem cell therapies.
         Outside of the lab, you’ll find Ethan working out at the gym, trying new recipes, playing guitar, and researching his family history. He also dedicates his time as a volunteer genetic genealogist with the non-profit Search Angels, helping adoptees in their search for biological family.

Research specialist

Nathan is a Jr. Specialist in the lab. He received his BS in Chemistry from UCLA and MS in Biotechnology from CSUCI. During his master's, he joined the lab of Charles K.F. Chan at Stanford through the CIRM Bridges Scholar Program. In the Chan lab, he studied SSCs and nanobody-based therapies to treat bone diseases. He is currently interested in studying the underlying mechanisms of Osteosarcoma and SSCs.

          During his free time, he enjoys taking walks, playing music, and doing research.