Research in the Jeremy Sugarman Lab focuses on biomedical ethics—particularly, the application of empirical methods and evidence-based standards to the evaluation and analysis of bioethical issues. Our contributions to medical ethics and health policy include work on the ethics of informed consent, umbilical cord blood banking, stem cell research, international HIV prevention research, global health and research oversight.

The Jun O. Liu Laboratory tests small molecules to see if they react in our bodies to find potential drugs to treat disease. We employ high-throughput screening to identify modulators of various cellular processes and pathways that have been implicated in human diseases from cancer to autoimmune diseases. Once biologically active inhibitors are identified, they will serve both as probes of the biological processes of interest and as leads for the development of new drugs for treating human diseases. Among the biological processes of interest are cancer cell growth and apoptosis, angiogenesis, calcium-dependent signaling pathways, eukaryotic transcription and translation.

The C. Kwon Lab studies the cellular and molecular mechanisms governing heart generation and regeneration. The limited regenerative capacity of the heart is a major factor in morbidity and mortality rates: Heart malformation is the most frequent form of human birth defects, and cardiovascular disease is the leading cause of death worldwide. Cardiovascular progenitor cells hold tremendous therapeutic potential due to their unique ability to expand and differentiate into various heart cell types. Our laboratory seeks to understand the fundamental biology and regenerative potential of multi-potent cardiac progenitor cells – building blocks used to form the heart during fetal development — by deciphering the molecular and cellular mechanisms that control their induction, maintenance, and differentiation. We are also interested in elucidating the maturation event of heart muscle cells, an essential process to generate adult cardiomyocytes, which occurs after terminal differentiation of the progenitor cells. We believe this knowledge will contribute to our understanding of congenital and adult heart disease and be instrumental for stem cell-based heart regeneration. We have developed several novel approaches to deconstruct the mechanisms, including the use of animal models and pluripotent stem cell systems. We expect this knowledge will help us better understand heart disease and will be instrumental for stem-cell-based disease modeling and interventions for of heart repair. Dr. Chulan Kwon is an assistant professor of medicine at the Johns Hopkins University Heart and Vascular Institute.

The Grayson Lab focuses on craniofacial and orthopaedic tissue engineering. Our research addresses the challenges associated with spatio-temporal control of stem cell fate in order to engineer complex tissue constructs. We are developing innovative methods to guide stem cell differentiation patterns and create patient-specific grafts with functional biological and mechanical characteristics. We employ engineering techniques to accurately control growth factor delivery to cells in biomaterial scaffolds as well as to design advanced bioreactors capable of maintaining cell viability in large tissue constructs. These technologies are used to enable precise control of the cellular microenvironment and uniquely address fundamental questions regarding the application of biophysical cues to regulate stem cell differentiation.

The Green Group is the biomaterials and drug delivery laboratory in the Biomedical Engineering Department at the Johns Hopkins University School of Medicine. Our broad research interests are in cellular engineering and in nanobiotechnology. We are particularly interested in biomaterials, controlled drug delivery, stem cells, gene therapy, and immunobioengineering. We are working on the chemistry/biology/engineering interface to answer fundamental scientific questions and create innovative technologies and therapeutics that can directly benefit human health.

The Greider lab uses biochemistry to study telomerase and cellular and organismal consequences of telomere dysfunction. Telomeres protect chromosome ends from being recognized as DNA damage and chromosomal rearrangements. Conventional replication leads to telomere shortening, but telomere length is maintained by the enzyme telomerase. Telomerase is required for cells that undergo many rounds of divisions, especially tumor cells and some stem cells. The lab has generated telomerase null mice that are viable and show progressive telomere shortening for up to six generations. In the later generations, when telomeres are short, cells die via apoptosis or senescence. Crosses of these telomerase null mice to other tumor prone mice show that tumor formation can be greatly reduced by short telomeres. The lab also is using the telomerase null mice to explore the essential role of telomerase stem cell viability. Telomerase mutations cause autosomal dominant dyskeratosis congenita. People with this disease die of bone marrow failure, likely due to stem cell loss. The lab has developed a mouse model to study this disease. Future work in the lab will focus on identifying genes that induce DNA damage in response to short telomeres, identifying how telomeres are processed and how telomere elongation is regulated.

Dr. Colantuoni and his colleagues explore human brain development and molecular mechanisms that give rise to risk for complex brain disease. His team uses genomic technologies to examine human brain tissue as well as stem models and vast public data resources.

The Espenshade Lab uses a multi-organismal and multidisciplinary approach to understand how eukaryotic cells measure insoluble lipids and dissolved gases. We have chosen cholesterol and oxygen as our model molecules, based on their essential roles in cell function and the importance of their proper homeostasis for human health.

The Erika Matunis Laboratory studies the stem cells that sustain spermatogenesis in the fruit fly Drosophila melanogaster to understand how signals from neighboring cells control stem cell renewal or differentiation. In the fruit fly testes, germ line stem cells attach to a cluster of non-dividing somatic cells called the hub. When a germ line stem cell divides, its daughter is pushed away from the hub and differentiates into a gonialblast. The germ line stem cells receive a signal from the hub that allows it to remain a stem cell, while the daughter displaced away from the hub loses the signal and differentiates. We have found key regulatory signals involved in this process. We use genetic and genomic approaches to identify more genes that define the germ line stem cells' fate. We are also investigating how spermatogonia reverse differentiation to become germ line stem cells again.

Utilizing a combination of tissue-based, cell-based, and molecular approaches, our research goals focus on abnormal telomere biology as it relates to cancer initiation and tumor progression, with a particular interest in the Alternative Lengthening of Telomeres (ALT) phenotype. In addition, our laboratories focus on cancer biomarker discovery and validation with the ultimate aim to utilize these novel tissue-based biomarkers to improve individualized prevention, detection, and treatment strategies.