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Urology Research Laboratory
Harrison Department of Surgical Research
Dr. Samuel K. Chacko
 
Affiliated Faculty/Investigators
 
Pamela S. Howard, Ph.D.

Current Projects
Research Associate Professor
University of Pennsylvania
School of Dental Medicine
240 South 40th Street
Philadelphia, PA 19104
Phone: 215 898-1571
Fax: 215 573-2324
E-mail: howard@biochem.dental.upenn.edu
 
Research Interest
Connective tissue proteins (collagens, elastin, associated glycoproteins), matrix metalloproteinases and TIMPs, urinary bladder cells (smooth muscle, fibroblasts, urothelium), TGF-beta and CTGF regulation of connective tissue in urinary bladder, neurogenic and anatomic bladder obstruction, and translational applications to alleviate bladder fibrosis
 
Description of Research

The major research focus in Dr. Howard’s laboratory is:

Molecular and Cellular Mechanisms Responsible For Urinary Bladder Fibrosis:
Studies focus on the role of transforming growth factor-beta (TGFB-1) and connective tissue growth factor (CTGF) in the pathogenesis of urinary bladder fibrosis, as well as the balance between collagen synthesis and degradation. Studies involve in vitro experiments utilizing human bladder smooth muscle and fibroblast cells to determine signaling pathways of regulation of collagenous proteins, types I, III and IV collagen both at the gene and protein level. In vitro experiments involve isolation of RNA, quantitative real time-PCR, ELISA, Western blotting, zymography, hydroxyproline analysis.

Role of Collagen in Bladder Development and Fibrosis: This research focuses on murine animal models in which either type I collagen or type III collagen has been genetically manipulated. Herterozygous animals model the altered type III:type I collagen ratio as seen in human pediatric bladder patient samples with either anatomic or neurogenic obstruction and allow for study of physiologic and mechanical properties of the bladder wall.

Urothelium – Detrusor Smooth Muscle Cross-Talk during Partial Bladder Outlet Obstruction: This study is part of the George O’Brien Urology Research Center supported by a P50 Grant award from the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK), National Institute of Health (NIH). This study will examine if detrusor smooth muscle receptor expression (purinergic, muscarinic), and urothelial basement membrane is altered in a murine model of bladder outlet obstruction, utilizing immunofluorescent confocal microscopy and transmission electron microscopy. In collaboration with Dr. Tung-Tien Sun of NYU, the uroplakin II knock-out mice will be studied to determine if signaling from the urothelium alters the contractile phenotype of the detrusor muscle.

Translational Research – Therapeutics to Alleviate Fibrosis: These studies focus on both in vivo animal models and in vitro bladder wall cell experiments to determine if hydroxymethylglutaryl CoA-reductase inhibitors can blunt or alleviate the development of bladder fibrosis. Outcome measurement are expression of CTGF, Types I and III collagen by molecular, biochemical, and histological techniques.

Technical Approaches include in vitro culture and biochemical manipulation of human bladder wall cells, in situ hybridization, Western blotting, quantitative Real-Time PCR, genetically manipulated mouse models, small animal surgery (bladder outlet obstruction), ELISA, hydroxyproline assays, zymography, immunohistochemistry, confocal microscopy, transmission electron microscopy, scanning electron microscopy.

 
Selected Publication
  1. Deveaud CM, Macarak EJ, Kucich U, Ewalt DH, Abrams WR, and Howard PS. Molecular analysis of collagens in bladder fibrosis. J Urol 1998; 160:1518 1527.
  2. Howard PS, Renfrow D, Schechter NM, and Kucich U. Mast cell chymase is a possible mediator of neurogenic bladder fibrosis. Neurourol Urodynamics 2004; 23:374-382.
  3. Howard PS, Kucich U, Coplen DE, and He Y. TGF-beta1 induced hypertrophy and matrix expression in human bladder smooth muscle cells. Urology 2005; 66:1349-1353.
  4. Stevenson K, Kucich U, Whitbeck C, Levin RM, and Howard PS. Functional changes in bladder tissue from type III collagen-deficient mice. Mol Cell Biochem 2006;
    238:107-114.
  5. Macarak EJ, Schulz J, Zderic S, Sado Y, Ninomiya Y, Polyak E, Chacko S, and Howard PS. Smooth muscle trans-membrane sarcoglycan complex is disrupted
    in partial bladder outlet obstruction. Histochem Cell Biol. 2006; 126: 71-82.
  6. Wei W, Howard PS, Kogan B, and Macarak EJ. Altered extracellular matrix expression the diverted fetal sheep bladder. J Urol 2007; 178:1104-1107.
  7. Wei W, Howard PS, Zderic SA, and Macarak EJ. Beta and gamma-sarcoglycans are decreased in the detrusor smooth muscle cells of the partially obstructed rabbit
    bladder. J Urol 2008; 179: 2052-2056.
 
Lab Personnel & Collaborations
  • Yuling He, DDS, Ph.D.
  • Douglas Coplen, MD., Washington University of St. Louis
  • Tung-Tien Sun, Ph.D., NYU School of Medicine
  • Wenjie Wei, MD
  • Jennifer A. Lopes, BA
  • R. Benjamin Johnson, BA

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