Faculty members in the Renal-Electrolyte and Hypertension Division engage in both basic laboratory research and leading-edge clinical research to further advance our understanding of and develop novel treatments for kidney disease.
Nephrology Basic Science Research
Lawrence Holzman, MD
Dr. Larry Holzman is an established and NIH funded laboratory investigator, well recognized for his investigations of mechanisms of cell signaling and also of podocyte biology, where he has contributed importantly to our understanding of the mechanisms that govern podocyte cytoskeletal architecture.
The Holzman lab studies the biochemistry and function of DLK, a member of the mixed lineage kinase family of MAPK kinase kinases. The laboratory initially discovered and cloned DLK and first demonstrated that DLK is a MAP3 kinase capable of activating the mitogen activated protein kinase family of JNK kinases. It showed that DLK is activated by insulin and in soon to be published work demonstrated that deletion of DLK in mice results in a phenotype of resistance to diet induced obesity and cell autonomous increased insulin sensitivity.
Dr. Holzman also investigates the biology of the glomerular podocyte, a unique epithelial cell that appears to play a central role in most forms of glomerular disease. The octopus-like processes of the podocyte interdigitate and form specialized intercellular junctions that function as the kidney glomerular filter. The lab has been a leader in characterizing the molecular components of this intercellular junction and first established evidence to support the hypothesis that these junctional components participate in regulating podocyte morphology by modulating actin cytoskeletal dynamics. The lab has particularly focused on signaling functions of members of the cell adhesion molecules of the Nephrin family and has contributed seminal work on the atypical cadherin FAT1. As part of this work, the lab has developed a transgenic mouse strategy for examining the functional biology of proteins and their interactions specifically in the podocyte that is now used internationally.
Katalin Susztak, MD, PhD
Dr. Katalin Susztak is a Professor of Medicine and Genetics at the University of Pennsylvania. She is a physician-scientist who aims to understand the genetics and molecular mechanism of kidney disease development, with the ultimate goal of finding new, more effective therapies.
Dr. Susztak has made discoveries fundamental to defining critical genes, cell types, and mechanisms of chronic kidney disease. She was instrumental in defining genetic, epigenetic, and transcriptional changes in diseased human kidneys. She identified multiple novel kidney disease genes and demonstrated the role of Notch signaling and metabolic dysregulation in kidney disease development.
Dr. Susztak's lab was the first to map the kidney epigenome and catalog genotype-driven gene-expression variation (eQTL) in human kidneys. Integration of genome-wide association studies (GWAS), eQTL and epigenome data have been essential to prioritize disease-causing genes and variants.
Dr. Susztak generated the first unbiased, comprehensive kidney cell-type atlas using single-cell transcriptomics. She identified that specific renal endophenotypes are linked and likely caused by the dysfunction of specific cell types. In follow-up animal model studies, she conclusively demonstrated that MANBA, DAB2, DACH1, and APOL1 are new kidney disease risk genes. Her work established the role of proximal tubule cells, endolysosomal trafficking, and metabolic and developmental pathways in kidney disease development.
Dr. Susztak's discoveries span genetics, genomics, epigenetics, molecular biology, physiology, and nephrology, and have enormous translational relevance and considerable therapeutic potential.
Dr. Susztak is a member of the American Society of Clinical Investigations, the American College of Physicians. She had received multiple awards, including the Young Investigator award from the American Society of Nephrology, the Alfred Richards lifetime award from the International Society of Nephrology, and the William Osler research award from the University of Pennsylvania.
Learn more about the Susztak Lab
Nephrology Clinical Research
Roy Bloom, MD
Dr. Roy Bloom is the Medical Director of the Penn Transplant Institute Kidney and Pancreas Transplant Program. He has served on KDIGO Work Groups related to the development of clinical practice guidelines for both managing hepatitis C virus in kidney disease, as well as for the management of kidney transplant recipients and has participated as a member of KDOQI Commentary Work Groups for the KDIGO Clinical Practice Guidelines related to both Care of the Kidney Transplant Recipient as well as for Lipid Management in Chronic Kidney Disease. His current research interest is focused in three major arenas. The first area of investigation involves clinical trials with contemporary and emerging therapies. Besides conducting studies with emerging immunosuppressive agents, his current clinical trial portfolio includes the assessment of both innovative strategies and regimens to reduce-transplant related complications such as ischemia-reperfusion injury, delayed graft function, new onset diabetes, as well as the use of novel non-invasive biomarkers as early diagnostic indicators of subsequent immune-mediated allograft injury. A second field of interest relates to pharmacokinetic evaluation of therapies in kidney recipients, specifically evaluating special subpopulations for whom available data on which to base dosing is relatively limited. A final investigational theme analyzes pre- and post-transplant outcomes related to viral infections, in particular hepatitis C virus, hepatitis E virus, CMV, HIV and BK virus.
Christina Hao Wang Brotman, MD, MSCE
Dr. Christina Brotman is a nephrologist and clinical epidemiologist whose primary research interests are in the areas of acute kidney injury, critical care nephrology, and renal replacement therapies. She has a background in biomedical engineering and mathematics, which has fueled her focus on improving advanced dialysis techniques. Her research has involved the study of alternative biomarkers for estimating kidney function and evaluating the risk of acute kidney injury following cardiac surgery. Her present work involves leveraging advanced optical techniques to quantify plasma refilling in real-time and examine how plasma refilling relates to hemodynamic stability during hemodialysis. Dr. Brotman is extending her work into the inpatient setting and using several concurrent optical monitoring techniques to examine how fluid removal during hemodialysis impacts plasma refilling, cardiac function, and cerebral perfusion in hospitalized patients requiring dialysis. Her future work aims to better evaluate the physiologic response to hemodialysis and to ultimately develop protocols to guide the management of dialytic therapy in the inpatient setting and minimize the adverse effects of hemodialysis.
Debbie Cohen, MD
Dr. Debbie Cohen is a Professor of Medicine with an interest in clinical research in the areas of hypertension, CKD and neuroendocrine tumors. She was the co-Principal Investigator (PI) on the NIH funded SPRINT study investigating different systolic BP goals in high-risk older adults many of which have CKD. She is also a co-PI on the CRIC study. She is the site PI on the renal denervation SPYRAL HTN-ON MED and OFF MED studies. She is also the co-director of the PENN Neuroendocrine Translational Center of Excellence, which has multiple clinical and translational ongoing studies in patients with pheochromocytomas or paragangliomas.
Jordana Cohen, MD, MSCE
Dr. Jordy Cohen performs clinical, translational, and epidemiologic hypertension and cardiorenal research. Her primary clinical interests are complex hypertension and chronic kidney disease. She leads a portfolio of research projects that 1) examine physiology-driven effects of antihypertensive medications in high-risk disease states and 2) seek novel strategies to improve blood pressure measurement. She is currently the PI or MPI of 3 R01 studies (including the BLOCK HFpEF Trial, a mechanistic trial evaluating calcium channel blockers vs. beta-blockers in patients with heart failure with preserved ejection fraction; the CAPRICORN Study, a cohort study evaluating vascular, cardiac, and kidney outcomes of COVID-19; and a multicenter EHR-based study evaluating longitudinal comparative effectiveness of antihypertensive medications) and co-I of multiple NIH- and AHA-funded studies including the Chronic Renal Insufficiency Cohort and HeartShare, among others.
Laura Dember, MD
Dr. Laura Dember conducts patient-oriented research in chronic kidney disease and end-stage kidney disease. She is a national leader for multicenter clinical trials and observational cohort studies including the Dialysis Access Consortium trials, the Hemodialysis Fistula Maturation Study, and the HiLo trial, all funded by the National Institutes of Health. She was the Principal Investigator for the Time to Reduce Mortality in End-Stage Renal Disease Trial (TiME), a cluster-randomized pragmatic trial that enrolled >7,000 participants conducted in partnership with two large dialysis provider organizations as one of the initial trials of the NIH Health Care Systems Research Collaboratory. She is the Principal Investigator of the Data Coordinating Center for the NIDDK Hemodialysis Novel Therapies Consortium, Principal Investigator of the Scientific and Data Research Center for the NIH HEAL Initiative HOPE Trial, and is a Multiple PI for the Scientific and Data Coordinating Center for the NIDDK Chronic Renal Insufficiency Cohort Study (CRIC), and is Multi-PI for a PCORI-funded comparative effectiveness trial of an electronic platform for symptom monitoring during hemodialysis. Dr. Dember has led projects for the Kidney Health Initiative, a public-private partnership between the American Society of Nephrology and the FDA to facilitate innovation in kidney disease treatments, served as Deputy Editor for the American Journal of Kidney Diseases, and is the Director for the Penn CCEB Certificate Program in Clinical Research.
Abdallah S. Geara, MD
Dr. Abdallah Geara is the Clinical Director of the PENN Glomerular and Onconephrology program. He is the Co-Director of the yearly PENN Glomerular CME meeting and member of the educational committee of the American Society of Onconephrology. His clinical research work focuses on glomerular diseases of the kidney. He is the principal investigator and sub investigator of more than eight phase 2 and phase 3 trials covering different glomerular diseases including: IgA Nephropathy (Calliditas, Protect, Origin, ALIGN), Membranous nephropathy (ValenzaBio VB119MN, Reboot), FSGS (DUET, DUPLEX…) and others. He publishes several novel observations covering different onconephrology diseases.
Simin Goral, MD
Dr. Simin Goral is the Director of PKD (Polycystic Kidney Disease) clinic at Penn. She has research interests in the areas of polycystic kidney disease, diabetic nephropathy, sensitization due to transplant nephrectomy, recurrent diseases including lupus nephritis after kidney transplantation, and BK infection after kidney transplantation. In her outpatient practice, she sees patients with PKD as well as patients coming for kidney transplant evaluation and listing. Dr. Goral has been the Principal Investigator and Co-Investigator in numerous completed as well as ongoing clinical trials, including the new studies on bardoxolone and lixivaptan use in PKD patients. She has also authored numerous articles and scientific abstracts presented at many national and international meetings.
Lawrence Holzman, MD
Dr. Larry Holzman is C. Mahlon Kline Professor of Medicine and Chief of Penn's Renal-Electrolyte and Hypertension Division at the University of Pennsylvania. His clinical research work focuses on glomerular diseases of the kidney. These are a large group of rare diseases that in aggregate account for a large fraction of patients whose kidney disease ultimately results in kidney loss, requiring dialysis or transplantation. Dr. Holzman co-founded NEPTUNE, an international consortium of academic medical centers for the clinical investigation of patients presenting with nephrotic syndrome including patients with steroid-resistant nephrotic syndrome, focal and segmental glomerulosclerosis and membranous nephropathy. This organization conducts an NIH-sponsored multi-year longitudinal observational study that is following a large number of patients with glomerular disease, collecting clinical data and biological samples that should allow a comprehensive understanding of these diseases. By applying a variety of scientific approaches including genetics, systems biology, biomarker discover and validation, and epidemiology NEPTUNE expects to make rapid progress during the coming few years. By participating as a principal investigator in a newly created NIH-supported consortium called CureGN, Dr. Holzman is helping lead a second complementary national consortium studying glomerular disease.
Yonghong Huan, MD
Dr. Yonghong Huan has research interests in hypertension, chronic kidney disease and vascular access. She is a board certified Nephrologist and a certified Hypertension Specialist by the American Society of Hypertension (ASH).
Dan Negoianu, MD
Dr. Dan Negoianu is a member of the steering committee of the AVOID-HF trial. This a national multicenter trial that plans to enroll 800 patients hospitalized for heart failure and fluid overload. The trial will compare fluid removal with an ultrafiltration machine (also sometimes called an aquapharesis machine) versus fluid removal via loop diuretics (the class of medications typically used to treat fluid overload). The primary outcome of the study consists of the rate of both hospital re-admissions and unscheduled treatments for fluid overload in the first 90 days after discharge.
Yuvaram Reddy, MBBS, MPH
Dr. Yuvaram Reddy is a nephrologist, health services researcher, and implementation scientist dedicated to
- developing and evaluating implementation strategies to narrow disparities in home dialysis use and
- evaluating the impact of health policy on health equity in kidney disease.
He is the Director of Diversity, Equity, and Inclusion for the Renal-Electrolyte & Hypertension Division, a Core Investigator at the VA Center for Health Equity Research and Promotion (CHERP), and a nephrologist at the Corporal Michael J. Crescenz VA Medical Center. He is also a member of the American Society of Nephrology Quality Committee and the American Society of Nephrology Home Dialysis Task Force. He is conducting a mixed-methods study to identify major home dialysis barriers (the IM HOME study; K12 HS026372) and is evaluating the health equity impact of a mandatory Medicare payment model on home dialysis use (Leonard Davis Institute pilot fund). His research draws from methodologies in health services research and implementation science.
Peter Reese, MD, PhD, FAST
Dr. Peter Reese is a transplant nephrologist and epidemiologist. He cares for patients at the Hospital of the University of Pennsylvania and the Philadelphia Veterans Affairs Medical Center.
His research focuses on:
- developing effective strategies to increase access to kidney transplantation;
- improving the process of selecting and caring for living kidney donors;
- determining outcomes of health policies on vulnerable populations with renal disease, including the elderly;
- testing strategies to improve important health behaviors such as medication adherence; and
- transplant ethics.
His prior work includes co-leading the first trials of transplanting organs from organ donors with hepatitis C virus infection into uninfected recipients, following by treatment with novel antiviral agents. His policy work includes serving as past chair of the ethics committee and a member of multiple other committees at the United Network for Organ Sharing, which regulates organ donation and transplant in the US.
Dr. Reese's mission encompasses energetic support of talented and motivated young researchers at all stages of training, supported by a K-24 grant from the NIH. Multiple mentees have received their own K and R-01 grants from the NIH and lead their own teams.
Dr. Reese's research support has included funds generously provided by:
- The National Institutes of Health
- A T. Franklin Williams Award in geriatric research (co-sponsored by the Association of Specialty Professors and the American Society of Nephrology) to examine the effects of emerging organ allocation proposals on older kidney transplant candidates
- The American Society of Transplantation
- A Greenwall Faculty Scholars Grant
Visit the Reese Lab for additional information
Michael Rudnick, MD, FACP
Dr. Michael Rudnick is an internationally recognized expert on Acute Kidney Injury from contrast media and specializes in treating vascular disease of the renal artery as causes of hypertension and chronic kidney disease. In addition, Dr. Rudnick is interested in the relationship between heart failure and renal function, so-called Cardiorenal Syndrome, and has published several papers in this area including the effect of artificial hearts (left ventricular assist devices) on the kidney. Finally, Dr. Rudnick is investigating a possible relationship between a specific group of laxatives called PEGs (polyethylene glycol) and acute kidney injury.
Deirdre Sawinski, MD (Adjunct Associate Professor)
Dr. Deirdre Sawinski conducts research in kidney transplantation. Her particular area of interest is in immunomodulatory viruses such as HIV and Hepatitis C, and their effect on renal transplant outcomes. She is also interested in viral complications of transplant, such a BK nephropathy. Dr. Sawinski is also partnering with the Penn Center for AIDS Research (CFAR) to study HIV+ kidney transplant recipients as a model for HIV eradication efforts.
Sarah Schrauben MD, MSCE
Dr. Sarah Schrauben is a nephrologist and epidemiologist and an Assistant Professor of Medicine and Epidemiology at the Perelman School of Medicine. Dr. Schrauben conducts patient-oriented research on the prevention, treatment, and outcomes related to people with chronic kidney disease (CKD). Her research program aims to improve the understanding of the optimal preventative and management strategies for kidney and cardiovascular disease, particularly for those who have been underrepresented in research, including the elderly, frail, and those with multiple chronic conditions through observational studies, clinical trials, and using qualitative research methods to provide in-depth understanding of patient-related issues. She also uses implementation science methods to increase uptake of evidence-based guidelines in CKD care.
Dr. Schrauben is a highly engaged member of two National Institute of Diabetes and Digestive and Kidney Diseases-sponsored consortia, the Chronic Renal Insufficiency Cohort (CRIC) Study, and the CKD Biomarkers Consortium (BioCon). She is Principal Investigator of a K23 Career Development Award focused on self-management behaviors in CKD and has developed a program leveraging mobile health (mHealth) technology to support self-management behaviors. Dr. Schrauben is also Principal Investigator of an R01 study to investigate how functional status changes over time in people living with CKD with the goal to identify modifiable risk factors for decline and sub-groups of individuals who may benefit from intervention. Dr. Schrauben's goal is to improve self-management and functional status in patients living with CKD to prevent complications of CKD and improve access to kidney transplantation.
Dr. Schrauben serves as site PI to multicenter randomized controlled trials: The HOPE Trial - a trial of behavioral and pharmacological interventions to reduce pain and opioid use among people with kidney failure receiving hemodialysis, and the MoVE Trial – a trial of motivational interviewing to increase dialysis adherence among people who self-identify as Black. She also serves as co-investigator on studies focusing on the unmet need for discovering biomarkers of heterogenous pathways that lead to CKD related complications, and implementation science studies.
Additional Information about Dr. Schrauben can be found on the following sites:
https://www.dbei.med.upenn.edu/bio/sarah-jeanne-schrauben-md-msce
https://ldi.upenn.edu/fellows/fellows-directory/sarah-schrauben-md-msce/
https://www.pennmedicine.org/departments-and-centers/department-of-medicine/divisions/renal-electrolyte-and-hypertension-division/research/research-interests
Srijan Tandukar, MD
Dr. Srijan Tandukar is an Assistant Professor of Medicine at the Penn Transplant Institute Kidney and Pancreas Transplant Program. He is building a comprehensive transplant database – REsearch on Solid ORgan Transplant (RESORT) database – to help streamline the clinical research activities conducted by Penn faculty members. He envisions a common data platform that will allow interested faculty members to rapidly query curated datasets to get answers for their research studies and also for day-to-day clinical care. The database will allow Penn to participate in regional, national and international consortiums, provide opportunities for interdisciplinary collaboration and help in rapid identification of patient cohorts for participation in clinical trials. The database build is funded by the McCabe Pilot Grant Award.
He is currently the site PI for the APOLLO (APOL1 Long-term Kidney Transplantation Outcomes Network) study and the co-PI for CARSK (Screening for Asymptomatic Coronary Artery Disease in Kidney Transplant Candidates) study. Apart from these, he is working with undergraduates, medical students, residents and fellows on various clinical research projects. These include outcomes in donation after circulatory death (DCD) pancreas transplants, impact of different preservation fluids in determining kidney transplant outcomes, kidney-liver and kidney-heart transplant policy changes and their impact on outcomes, long term outcomes in BK viremia, impact of cardiovascular comorbidities and pre-existing hematological.
Raymond Townsend, MD
Dr. Ray Townsend performs research in the role of vascular compliance in CKD progression and incident CVD events in CKD. He is currently the Vice President of the American Society of Hypertension (ASH), and the President of the North American Artery Society. He is also an Associate Program Director in the Clinical and Translational Resource Center (CTSA award). He is PI for the Philadelphia Center of the Chronic Renal Insufficiency Cohort (CRIC) study and the PI for the Philadelphia Center (part of the OHIO Hub) of the Systolic Pressure in Blood Pressure Intervention Trial (SPRINT). He is also a member of the Program Committees for the 2014 ASH scientific meeting (May 2014) and AHA Council for High Blood Pressure Research (CHBPR; September 2014). Lastly, he is the Director of the Penn Hypertension Center, An ASH-certified Level 1 Hypertension Center.
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