The McCallion Laboratory studies the roles played by cis-regulatory elements (REs) in controlling the timing, location and levels of gene activation (transcription). Their immediate goal is to identify transcription factor binding sites (TFBS) combinations that can predict REs with cell-specific biological control--a first step in developing true regulatory lexicons. As a functional genetic laboratory, we develop and implement assays to rapidly determine the biological relevance of sequence elements within the human genome and the pathological relevance of variation therein. In recent years, we have developed a highly efficient reporter transgene system in zebrafish that can accurately evaluate the regulatory control of mammalian sequences, enabling characterization of reporter expression during development at a fraction of the cost of similar analyses in mice. We employ a range of strategies in model systems (zebrafish and mice), as well as analyses in the human population, to illuminate the genetic basis of disease processes. Our long-term objective is to use these approaches in contributing to improved diagnostic, prognostic and therapeutic strategies in patient care.

The Lau Lab uses a combination of computational and experimental approaches to study the atomic and molecular details governing the function of protein complexes involved in intercellular communication. We study ionotropic glutamate receptors (iGluRs), which are ligand-gated ion channels that mediate the majority of excitatory synaptic transmission in the central nervous system. iGluRs are important in synaptic plasticity, which underlies learning and memory. Receptor dysfunction has been implicated in a number of neurological disorders.

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 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. Borahay's lab focuses on understanding pathobiology, developing novel treatments, and carrying out high quality clinical trials for common gynecologic problems with a special focus on uterine fibroids. Our lab also investigates the causes and novel treatments for menstrual disorders such as heavy and irregular periods. In addition, Dr. Borahay’s team explores innovative approaches to minimally invasive gynecologic surgery, focusing on outpatient procedures with less pain and faster recovery times.

The Wang lab focuses on the signals that direct the differentiation of pluripotent stem cells, such as induced-pluripotent stem (iPS) cells, into hematopoietic and cardiovascular cells. Pluripotent stem cells hold great potential for regenerative medicine. Defining the molecular links between differentiation outcomes will provide important information for designing rational methods of stem cell manipulation.

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.

The Frederick Anokye-Danso Lab investigates the biological pathways at work in the separation of human pluripotent stem cells into adipocytes and pancreatic beta cells. We focus in particular on determinant factors of obesity and metabolic dysfunction, such as the P72R polymorphism of p53. We also conduct research on the reprogramming of somatic cells into pluripotent stem cells using miRNAs.

David Hackam’s laboratory focuses on necrotizing enterocolitis (NEC), a devastating disease of premature infants and the leading cause of death and disability from gastrointestinal disease in newborns. The disease strikes acutely and without warning, causing sudden death of the small and large intestines. In severe cases, tiny patients with the disease are either dying or dead from overwhelming sepsis within 24 hours. Surgical treatment to remove most of the affected gut results in lifelong short gut (short bowel) syndrome. The Hackam Lab has identified a critical role for the innate immune receptor toll-like receptor 4 (TLR4) in the pathogenesis of necrotizing enterocolitis. The lab has shown that TLR4 regulates the development of the disease by tipping the balance between injury and repair in the stressed intestine of the premature infant. Developing an Artificial Intestine A key goal is to create, in the laboratory, new intestines made from patients’ own cells, which can then be implanted into the patient to restore normal digestive function. This innovative design could transform child development and quality of life in necrotizing enterocolitis survivors without the risks of conventional donor transplant.

The research in the Svetlana Lutsenko Laboratory is focused on the molecular mechanisms that regulate copper concentration in normal and diseased human cells. Copper is essential for human cell homeostasis. It is required for embryonic development and neuronal function, and the disruption of copper transport in human cells results in severe multisystem disorders, such as Menkes disease and Wilson's disease. To understand the molecular mechanisms of copper homeostasis in normal and diseased human cells, we utilize a multidisciplinary approach involving biochemical and biophysical studies of molecules involved in copper transport, cell biological studies of copper signaling, and analysis of copper-induced pathologies using Wilson's disease gene knock-out mice.