Research Group of Dr Gerard Apodaca, University of Pittsburgh

Research Group of Dr Gerard Apodaca, University of Pittsburgh

Dr Gerard Apodaca is an associate Professor of Medicine in the departments of Medicine and Cell Biology and Physiology at the University of Pittsburgh. Gerard’s research group studies membrane traffic in the specialized epithelial cells that line the nephrons of the kidney and the inner surface of the bladder.

All cells are capable of sampling their environment through a process called endocytosis. During endocytosis both cellular membrane as well as extracellular fluid are internalized and then transported to various intracellular compartments. The Apodaca lab is interested in delineating these compartments, determining in which compartments different membrane components and fluid are sorted from one another, and analyzing the regulatory mechanisms that control membrane flow into and out of these compartments. The laboratory is also looking at the function of the bladder umbrella cells that sit at the interface between urine and the underlying tissue. The lab is particularly interested in how the abundant population of discoidal vesicles, which underlie the apical cell surface of umbrella cells, fuse with the apical plasma membrane in response to bladder filling.

Gerard is a graduate of Rollins College in Winter Park, Florida and received his Ph.D from the University of California, San Francisco in 1989. He did his post doctoral research at the University of California in the laboratory of Keith Mostov before moving to his current position in the University of Pittsburgh in 1995.

The Apodaca lab is equipped with multiple G4/G5 Macintosh workstations with image analysis software packages including Volocity. They also have a separate microscope facility, which contains a confocal system and inverted microscope fitted with a CCD camera, a Z-focus controller, and Improvision Openlab deconvolution software. Openlab is used to project serial sections into one image. Volocity Visualization is used to generate X-Z sections and three-dimensional tilted projections of images captured from whole mounts. Volocity Classification is used to measure the degree of overlap between labeled objects in each channel. Gerard notes that “Volocity is an invaluable tool to understand the three-dimensional architecture and distribution of organelles in complex epithelial tissues. The ability to measure co-localization in three-dimensional volumes is especially important to our research.”

For more information about research done in the Apodaca lab please visit their web site, where you will find a number of stunning images in their image gallery.

Localization of claudin-8 in bladder epithelium. Whole mounted epithelium from rat bladder was labeled with antibodies to claudin-8 (green) and rhodamine-phalloidin (red). A merged image is shown. A: image is a 3-dimensional reconstruction made in Volocity of a z-series collected with a confocal microscope. The image was tilted 65° about the x-axis. The grid is a 3-dimensional scale marker, with each side of the square equivalent to ~12.3 µm. B: x-z confocal section of the tissue, taken from the Image view in Volocity. The arrows mark the location of tight junctions.

Reprinted from Distribution of the tight junction proteins ZO-1, occludin, and claudin-4, -8, and -12 in bladder epithelium.
Prasad Acharya, Jonathan Beckel, Wily G. Ruiz, Edward Wang, Raul Rojas, Lori Birder and Gerard Apodaca
AJP - Renal 287:305-318, 2004.
With permission of the American Physiological Society.