Research Overview
The following are research studies currently being conducted in the Department of Dermatology:
Alice Pentland, M.D.
Research in the Pentland Lab addresses the role of cyclooxygenases and phospholipases in epidermal function. There are two major areas these studies address: their role in carcinogenesis and in cell differentiation. The role of these lipid mediators in the induction of squamous cell carcinoma of the skin is being studied in the context of ultraviolet light injury. Ultraviolet light exposure is known to be a complete carcinogen, inducing both squamous and basal cell carcinomas in skin. Recent work has shown that significant contributions to tumor initiation and promotion may be made by eicosanoids (arachidonic acid and its metabolites). Most importantly, available inhibitors of prostaglandin synthesis have been shown to have anti-tumor properties in colon cancer in humans. UV exposure results in substantial increases in eicosanoid formation; work in the lab is therefore designed to directly link UV-induced eicosanoid synthesis to tumor initiation and promotion in humans.
The validity of this hypothesis will be tested by showing 1) eicosanoid metabolite formation is induced by chronic irradiation and in squamous cell carcinoma; 2) the increased quantities of these metabolites formed in epidermis produce in vitro changes supportive of tumor formation; and 3) UV carcinogenesis is decreased in knockout animals lacking prostaglandin forming enzymes COX-1, COX-2, and the PGE receptor EP2. In vitro overexpression of cyclooxygenase and phospholipase enzymes on the response of cell cultures to UV irradiation is currently being examined. The impact of product synthesis on UV-induced changes in cell cycle progression and apoptosis are a central focus. Emphasis is placed on the signaling mechanisms triggered by UV irradiation and the impact of prostaglandins or free fatty acids on keratinocyte function. In addition to these approaches in tissue culture, acute and chronic in vivo experiments are also underway with COX-1 and COX-2 knockout mice. Prostaglandin receptor regulation in vivo and in vitro by irradiation, which contributes to cAMP and Ca++ second messenger pathways are also under study. New in vivo confocal microscopy techniques to characterize the burden of mutation and repair in skin are also being employed. The trainees will also become expert in the fields of photobiology and eicosanoid biology. These two areas are underrepresented in Dermatology training programs, and are therefore important additions to the training program at Rochester.
Lisa A. Beck, M.D.
Dr. Beck's research interests are in three interrelated areas. First, we are interested in chemokines role in cell migration and activation particularly as it relates to allergic inflammation. Our work suggests the responsiveness of leukocytes to chemokines is significantly affected by their state of priming. This explains why tissue expression of chemokines is necessary but not sufficient for leukocyte migration into tissue compartments. The second area is understanding the role that chemokine receptors play on structural cells with a major focus on epithelial cells (airway and cutaneous). Our work suggests that both CCR3 and CCR5 are expressed on these cell types and that they probably have several functions, amplifying inflammation, and fibrogenic/wound repair. The third area is studying the innate immune pathways relevant for response to Staphylococcus aureus and the viruses (HSV and MCV) in keratinocytes from atopic dermatitis subjects contrasted with healthy, nonallergic controls and subjects with other inflammatory skin diseases not characterized by the clinical complication of superinfection with these microbes.
Dr. Beck's laboratory staff includes Lisa Latchney, M.S. Sr. Tech Associate, Lora Bankova, M.D., Postdoctoral Fellow, and Anna DeBenedetto, M.D., Postdoctoral Fellow. Ms. Latchney oversees all aspects of the laboratory including ordering, training postdocs, immunohistochemistry, basic cell, and molecular biological assays; she works on her own projects as well. She will begin work on a project which will evaluate the immune response observed in a HSV skin explant infection model contrasting the response observed in subjects with AD compared to nonatopic, healthy controls, and subjects with psoriasis. Dr. Bankova is currently studying why neutrophils do not migrate into the skin of AD subjects despite the fact that 90% of subjects are colonized with Staphylococcus aureus. Our data would suggest that this is a feature of AD neutrophils as neutrophil chemoattractants are found in AD lesions. We will contrast this with psoriasis a Th1-polarized disease, which is similarly characterized the relative lack of eosinophils despite the fact that psoriatic tissue expresses eosoinophil chemoattractants. The hypothesis being tested is that the state of priming of circulating leukocytes predicts their response to tissue-derived chemotactic stimuli. Dr. Bankova has received the 2006 AAAAI Astellas Skin Research Grant to pursue this work. Dr. DeBenedetto is evaluating the expression and function of B7 cosignaling molecules on cutaneous epithelial cells or keratinocytes. Dr. DeBenedetto is also looking for differences in innate immune receptors present on human keratinocytes which are relevant for Staphylococcus aureus recognition. The central hypothesis is that there are differences in the expression and/or function of these receptors between keratinocytes isolated from subjects with atopic dermatitis compared with keratinocytes from psoriasis and normal nonallergic controls. This question emerges because AD subjects are colonized with these bacteria—even at nonlesional sites and the bacteria directly or indirectly (by release of toxins) enhances cutaneous inflammation. To perform these studies, keratinocytes are obtained from nonlesional skin sites following suction blister formation on untreated, non-sun exposed skin and compared with keratinocytes from psoriasis and normal nonallergic controls. We are monitoring the expression (at the mRNA and protein levels) of relevant PRRs for S. aureus in these three subject groups and looking at their function as well. We have initiated expression profiling studies on these cells as well to better characterize the breadth of the defect in AD keratinocytes.
Lisa DeLouise, Ph.D.
The overall research area in the laboratory is the creation of Smart Bandage Biomaterial Engineering and Skin Disease. This laboratory investigates the fundamental optical, morphological, and surface chemical properties of bioengineered nanoporous silicon (PSi) in developing a platform of Smart Bandage technologies targeting biosensors for point of care diagnosis of cutaneous disease, transdermal drug delivery, and tissue engineering for wound healing. PSi is fabricated from single crystal silicon wafers using an electrochemical etch process. The pore diameter, porosity (surface area and internal void volume), bioerosion, and interferometric optical properties can be tailored over a wide range to suit the application. Ongoing projects involve developing a refractive index sensitive biosensor for detection of Candida ablicans for which we've developed methods to site direct the immobilization of phage display scFv antibody receptors. Tests are underway to evaluate detection sensitivity relative to nonspecifically immobilized whole IgG aCandida antibody receptor employing commercial antigen. Fundamental insights into the factors (pore size, steric crowding, operating frequency, device architecture, blocking agent, operation protocol, etc.) that impact detection sensitivity are being explored. Biosensor tests are typically conducted on devices attached to the silicon wafer. Recently, we developed methods to detach the sensor and mount it in a polymer support. We are conducting studies to characterize the diffusion characteristics of small molecules though hydrogel films (40 micron) cast over porous silicon sensor (4 um) by monitoring changes in the optical response that result when molecules diffuse in or out of the porous silicon layer. This work will enable us to develop models for designing transdermal drug delivery systems where the optical response can be measured, while applied to the skin, to monitor the time released delivery of therapeutics concentrated within the porous reservoir. We are interested in developing a smart bandage to deliver antifungal locally to the nail matrix where nail progenitor cells live. We are also investing the morphology and phenotype dermal human fibroblast and immortalized keratinocytes (HaCaT) cells cultured on chemically modified PSi and flat silicon wafer surfaces. The goal is systematically engineer the surface chemistry, energy and topography of biomaterial scaffolds to mimic the fetal reepithelialization process. Our hypothesis is that by controlling differential cell proliferation (keratinocyte vs. fibroblast) and cell phenotype, such as integrin and metalloproteinase expression profiles or the magnitude of actin fiber extensions, novel therapies will result that can accelerate the healing of chronic wounds (ulcers) and burns with reduced scarring. A unique aspect of this research program is the melding of cross-disciplinary skills in surface science, physical chemistry, microfluidic device engineering, optics, and biological and medical sciences. This interdisciplinary approach provides a firm basis for the investigation and fabrication of new biomedical devices, while enabling a broader perspective on quantifying biological efficacy and establishing clinical utility.
Mary Gail Mercurio, M.D.
Dr. Mary Gail Mercurio is the Clinical Director in the Department of Dermatology at the University of Rochester Medical Center in Rochester, New York. She is the primary clinical attending in the department. She also heads the dermatology curriculum for first- and second-year medical students at the University of Rochester.
Dr. Mercurio's clinical interests in dermatology have focused on skin and hair disorders afflicting women with particular interest in the hormonal effects of hyperandrogenism. She works closely with obstetrics and gynecology colleagues collaborating in a joint clinic for women with a variety of skin conditions, including vulvar skin disorders and those rashes that are unique to pregnancy. She is the director of the dermatology clinical trials unit, and is actively participating in trials pertaining to psoriasis, vulvar dermatitis, and melanoma. Her research is supported in part by the National Institutes of Health.
Benjamin Miller, Ph.D.
Research in the Miller group focuses on the fundamental goal of understanding the structure, function, and molecular interactions of biomolecules through the design, synthesis, and structural analysis of novel small-molecule ligands. In particular, our efforts focus on binding (and mimicry) of cell-surface carbohydrates. Addressing this goal requires advances in our understanding of the factors underlying molecular recognition, our ability to synthesize complex molecules, and in analytical methods. We are also interested in applying combinatorial chemistry techniques (including a novel combinatorial method of small-molecule evolution called Dyanmic Combinatorial Chemistry) to the discovery of small molecules that can serve as probes of cell signaling pathways. In collaboration with the research groups of Lisa Delouise, Philippe Fauchet, Lewis Rothberg, and Todd Krauss in the Center for Future Health at the University of Rochester, our group is working toward the development of novel organic receptors that are specific for a variety of human pathogens (with a particular focus on skin), and the integration of such receptors into optical devices. We have recently successfully used this technology to demonstrate the first highly selective sensors for enteropathogenic E. coli, and for methicillin-resistant Staphylococcus aureus. Such novel sensors capable of detecting and identifying human pathogens have the promise of providing a significant positive impact on human health.
Art Papier, M.D.
Dr. Art Papier is an Associate Professor in Dermatology and Medical Informatics. His research focuses on the development and study of "real-time" reference systems for physicians and consumers concentrating on visually rich knowledge areas. He is particularly interested in computerized health records and decision support systems and research aimed at defining their optimal use to support dermatologic decision-making. Dr. Papier has a number of studies in progress. One research focus area involves the development and testing of graphical icons to aide the searching of visual databases by non-experts.
Dr. Papier is also PI of a NIAMS/NIH contract to develop a comprehensive dermatology lexicon. The development of a Dermatology Lexicon (www.dermatologylexicon.org) is a multi-year project involving consulting dermatologists from around the country. The goal of the project is to create and codify a comprehensive dermatology terminology set that will facilitate improved clinical and research communication, and the future development of computer based information tools.
Glynis Scott, M.D.
Melanin pigment is of paramount importance in protecting skin from the mutagenic effects of solar irradiation. The ability of melanocytes to extend dendrites, and to transport pigment-laden melanosomes to keratinocytes, is an absolute requirement for adequate pigmentation in the skin. Prostaglandins (PG) are lipid signaling molecules released by keratinocytes in response to ultraviolet irradiation (UVR). The effects of PGs on melanocyte function are essentially unknown. Our data show that PGE2 and PGF2a stimulate dendricity in human melanocytes (HM), and we have defined the expression of PGE2 and PGF2a receptors in HM. Our research focus is on defining signaling intermediates that mediate PGE2 and PGF2a-dependent HM dendricity and melanosome transfer. We examine relative levels of prostanoid receptors and their regulation by UVR in vitro and in vivo and use a novel model of rab27b-GFP labeled melanosomes to define effects of PG on melanosome transfer. We examine the contribution of the small GTP-binding proteins Rac, Rho, and Cdc42 on PG-induced melanocyte dendrite formation and melanosome transfer through affinity precipitation of activated proteins following receptor stimulation. We are also interested in defining the function of phospholipases, particularly secretory phospholipases (sPLA2) in HM. Based on the known effects of sPLA2 on other cells, we hypothesize that sPLA2 will regulate HM dendricity, melanosome transfer and potentially HM proliferation and pigmentation. We have begun to examine the expression and regulation of sPLA2 subtypes in HM and to define their function(s). Because HM dendricity and melanosome transfer are critical components of cutaneous photoprotection, knowledge into mechanisms of prostanoid and sPLA2-dependent effects on HM could lead to greater insight into photochemoprevention.
A technique used in our laboratory to directly examine melanosome transfer to keratinocytes is digital imaging of human melanocyte/keratinocyte co-cultures. We have observed that filopodia, actin-based structures, are conduits for melanosome transfer through the use of these high-resolution movies. The movies on this website demonstrate some examples of the dynamic nature of filopodia movement in human melanocytes, and the ability of melanosomes to traverse these structures.
Francisco Tausk, M.D.
Two major research projects are ongoing.
Classical Conditioning in the Pharmacotherapy of Psoriasis: Placebo arms are required in clinical trials in order to evaluate the non-specific effects of drug administration. One mechanism by which these are believed to work is Classical Conditioning. Our hypothesis is that patients exposed to a successful treatment, will subsequently benefit from the administration of a placebo through the mechanism of expectancy. We are conducting a study in which subjects with severe psoriasis will be treated with cyclosporine until remission, at which point we will maintain them clear with significantly lower doses of the drug by interspersing placebo with their schedule of cyclosporine.
Effects of Stress on UV induced carcinogenicity: We have recently shown that psychological stress significantly accelerates the development of UV induced Squamous Cell Carcinomas in SKH mice. Our laboratory is interested in understanding the mechanisms underlying the effects of stress on the biology of the skin, in particular, wound healing, as well as the generation of skin cancer.
James Zavislan, Ph.D.
Dr. Zavislan's work centers on non-invasive optical imaging of skin and epithelial tissues. His recent work in this area has included the development of a FDA-cleared confocal microscope to image the cellular morphology of exposed in-vivo and ex-vivo tissue. Under Dr. Zavislan's direction this device has been used in multi-center trials for the detection of melanotic and non-melanotic skin cancers and to assess the surgical margins of Moh's micrographic surgery. This device has also been used to non-invasively monitor the method of action and efficacy of systemic and topical pharmacological therapies.
Dr. Zavislan is interested in developing optical systems that utilize endogenous optical contrast to specifically identify tissue structures and tissue properties in-vivo with special emphasis on identifying and differentiating immune cells. The current generation of in-vivo confocal instruments integrate the back reflected light to encode the images. The phase state and coherence of the back-scattered light encodes additional information. Utilizing this information, different cellular, or stromal structures with similar overall back-scatter intensity can be differentiated. These tissue specific images will be correlated to traditionally prepared pathology specimens. The overall goal is to develop instruments (both hardware and algorithms) that provide clinicians diagnostic and therapeutic information at the point and time of care.
Under this training grant, optical engineering students will be given the opportunity to integrate their instrument designs into a clinical setting. Within the clinical environment the students will be introduced to the important work flow constraints of clinical medicine. Technology development will directed toward a clinical setting from the beginning of the project, not as an epilogue.
