Philadelphia –The Joseph and Josephine Rabinowitz Award for Excellence in Research is supporting new collaborations across disciplines, presented this year to two Penn Dental Medicine faculty members who will be working on projects with colleagues from other Penn schools. The awards were presented at a reception at Penn Dental Medicine on January 24.
This year’s recipients are Dr. Hydar Ali, Professor, Department of Pathology, and Dr. Ricardo Walter, Assistant Professor of Restorative Dentistry. Dr. Ali and his collaborator, Emer Maria Smyth, PhD, Research Associate Professor of Pharmacology with Penn’s Institute for Translational Medicine and Therapeutics, were selected for their proposal “Cross-Regulation of G Protein Coupled Receptor Signaling in Human Mast Cells.” Dr. Walter and his collaborators – Virgil Percec, PhD, P. Roy Vagelos Professor of Chemistry, and Andrew E. Feiring, PhD, Adjunct Professor of Chemistry, both in Penn’s School of Arts & Sciences — received the award for their proposal “Development of a Novel Bisphenol A-Free Composite Resin Restorative Material.”
“Our project focuses on a new aspect of C3aR biology and utilizes a relatively new technique to determine how it interacts with other cell surface proteins to induce signaling,” says Dr. Ali in describing their proposal that looks at G protein coupled receptors (GPCR) for the complement component C3a (C3aR), which play an important role in asthma and its exacerbation by respiratory viruses. Until now, he notes, the main focus of research has been to determine how C3aR phosphorylation and the subsequent recruitment of adapter molecules regulate receptor function in human mast cells. However, he adds that the possibility that C3aR function may be cross-regulated by other seven transmembrane domain proteins has not been considered.
“In our study, we will test the hypothesis that C5L2, a non-signaling seven transmembrane domain protein, contributes to C3aR signaling in human mast cells,” says Dr. Ali. “We will then utilize bioluminescence resonance energy transfer (BRET) technology to test the hypothesis that C3aR forms a heterodimer with C5L2.”
In his study, Dr. Walter and his collaborators are responding to recent concerns that have been raised regarding adverse effects from the elution of bisphenol A (BPA) from restorative materials. BPA is an endocrine disruptor that mimics estrogen and clinical studies have linked the presence of composite resin restorations with worse psychosocial functioning and an increase in urinary BPA concentration in children, and initial recommendations have been made to minimize the use of such materials during pregnancy.
“Given the widespread use of dental composite resin restorations, finding a replacement monomer for the BPA-derived monomers used in dentistry is a pressing issue,” notes Dr. Walter, adding that a potential substitute of bisphenol A glycidyl methacrylate (bis-GMA), one of those BPA-derived monomers in dental formulations, is acrylamides made from plant-derived diols. “These may replace the bis-GMA with non-estrogen-like intermediates, which derive from renewable resources (cellulose),” he adds. “Our aim is to design and evaluate bis-acrylamides-based composite resins with physical and mechanical properties at least similar of those of current materials.”
Th Rabinowitz Award was established in 2002 through the generosity of the late Dr. Joseph “Jose” Rabinowitz, an active member of the School’s Biochemistry faculty for 29 years, and his wife, Josephine. Dr. Rabinowitz joined Penn’s School of Medicine faculty in 1958 and moved to Penn Dental Medicine in 1963, where he served on the active faculty through 1992. Even after becoming Professor Emeritus, he continued to teach in the Biochemistry Department until his death in 2009. Dr. Rabinowitz was known for his research in lipid and steroid biochemistry, and made the seminal discovery that HMG CoA was a key intermediate in cholesterol biosynthesis. His research helped lead to the development of the important class of cholesterol-lowering drugs known as statins.
The Rabinowitzes endowed this award to promote independent research among Penn Dental Medicine faculty members. “Their generosity in endowing this research award ensures that Jose’s legacy as a scientific mentor will continue at Penn Dental in perpetuity,” noted Dr. Ellis Golub, Interim Chair and Professor, Department of Biochemistry, in opening remarks at the awards presentation. “He was a pioneering scientist and highly respected teacher, who is warmly remembered by the Penn Dental Medicine community.”
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