One of your earliest childhood biology lessons probably occurred when your body demonstrated to you that your skin is an organ that is able to self-regenerate. Indeed wound healing is a fascinating process in which cells carry out a precise and complex choreography that includes cellular differentiation and regulation of gene expression.
Our lab studies a particular cell type called dermal fibroblasts. If a wound occurs, they migrate to the site of injury, change into muscle like cells (myofibroblasts) that contract to help with wound closure, and, once the wound has healed, enter programed cell death to clear the work area. Disruption to this process can result in chronic ulcers or keloid scarring. A major goal of our studies is to understand how the fibroblast to myofibroblast transition is regulated, so that therapeutic strategies can be devised to prevent and treat this pervasive problem.
In addition to our motivation to understand wound healing in order to learn how to control it and cure its pathologies, wound healing is an accessible system to study more general differentiation events involved in tissue regeneration. By studying the changes that fibroblasts undergo during wound healing, we revealed an important mechanism of gene regulation that could help to explain more generally how cells maintain a particular identity and how they can be driven to a different state. The molecules we identified are known to control general gene activity as well as the spatial organization of genes within the cell’s nucleus. The studies proposed here will further investigate those findings.
One of the ways in which our laboratory studies how cells control gene activity is by directly visualizing gene expression. Using highly specialized microscopy, biochemistry and computer analyses, we are able to observe the behavior of individual gene regulatory molecules within individual living cells. We will continue to use and improve these methods to better understand how genes are controlled. We believe that these studies will open the door to new strategies in cellular reprogramming and potentially to new strategies for modifying cells for therapeutic use.
Our research program includes clinically relevant and translational studies of wound healing, development and transfer of new imaging technologies to enable investigators to visualize the behavior of individual molecules within living cells, and basic biological studies seeking to understand fundamental mechanisms of gene regulation that control stem cell pluripotency and differentiation. These endeavors will benefit the State of California in various different and overlapping ways.
Successful development of stem cell-based therapies hinges on the ability to control cell identity and cell fate. By contributing to the understanding of fundamental gene regulatory mechanisms controlling pluripotency and tissue-specific differentiation, the research proposed here has the potential to influence and positively impact a wide range of regenerative medicine studies ongoing in the state.
Chronic skin ulcers are a pervasive and dangerous human medical problem. Current treatments can be slow and painful, and are too often ineffective, resulting in the necessity of limb amputation. The true economic and personal cost of chronic ulcers is difficult to quantify because public health research most frequently includes it as a symptom of systemic disease. However, in 2009 chronic ulcers were estimated to affect 6.5 million patients in the Unites States, with treatment costs in excess of 25 billion dollars. Our identification of specific factors that control the fibroblast to myofibroblast transition suggests new approaches to differential diagnosis and to treatment of chronic wounds using fibroblasts and myofibroblasts as direct targets or therapeutic agents.
The ability to detect, track and manipulate individual gene regulatory molecules in living human cells is a disruptive technology that already is having a major impact in developmental biology and stem cell research. Technologies for imaging individual molecules in live cells are evolving so rapidly that they are difficult to commercialize and are therefore available only to a relatively small number of laboratories that are able to build these systems from component parts. Our lab will serve as a center to help develop these technologies, and to help other laboratories adopt these powerful new research tools. California also has a rich industrial base in microscopy development and engineering. The development and implementation of new super resolution live cell imaging technologies such as we propose here will offer many opportunities for collaboration between industry and academia, opening new markets and enabling the spread of these innovations throughout academic and bio-pharmaceutical laboratories. This synergism, in turn, will accelerate research in regenerative therapeutics.
The applicant is an early career, independent investigator with expertise in both the development of imaging technology and biology. The proposed research for the Leadership Award comprises a combination of technology development, single molecule live cell imaging and biophysical analysis of transcriptional regulation with the goal of providing new insight into the basic mechanisms regulating gene expression during cell differentiation. This approach will be applied to the study of how fibroblast cells in the skin convert to myofibroblasts during wound healing, a critical process for regenerative medicine.
Research Vision and Plans
- The combination of state-of-the-art biochemical assays with cutting-edge microscopy and imaging methods has the potential to provide valuable new insight into the basic mechanisms regulating gene expression during differentiation.
- The technology development component of the proposal is particularly innovative and leverages existing CIRM-funded infrastructure and expertise at the applicant institution.
- Reviewers differed in their opinion about the potential impact of the proposed work on the stem cell field. Some emphasized that the proposed approaches are entirely novel and felt that they will be very valuable in addressing unanswered questions in stem cell biology, especially given the heterogeneities inherent in stem cell cultures. Others questioned whether information obtained from the proposed experiments will significantly advance the field of stem cell biology, since they are focused on a transcription and do not take into account other aspects of cellular regulation.
PI Accomplishments and Potential
- The PI is recognized as a pioneer in the development of microscopy and computational tools for following the movement of molecules in living cells, a powerful and enabling technology.
- The PI has been extremely successful as a junior investigator and has produced an impressive body of innovative work. This is represented by a large number of published papers, many in the best journals in the field, since establishing an independent laboratory.
- One concern is the applicant’s lack of experience working with stem cells. However, since the applicant has established a number of successful interdisciplinary collaborations in the past, reviewers had confidence that s/he would be able to take advantage of local expertise at the applicant institution to collaborate and bring the use of new technology into the stem cell field.
- Letters from mentors and colleagues describe the applicant as an unusually creative scientist, on a high upward trajectory and a 'prize recruit' to California and to the stem cell field.
Institutional Commitment and Environment
- The applicant would be an ideal fit and would strengthen an already excellent environment for developing sophisticated imaging technology at the applicant institution.
- Reviewers appreciated that the PI has already established collaborations at the applicant institution.
- The applicant institution is providing an excellent equipment fund and start-up package to enable the PI’s success.
- Overall, the research environment at the applicant institution is excellent. Reviewers appreciated that the institution will provide access to the expertise of stem cell biologists and core facilities working with human pluripotent stem cells.