June 2007 | VOL. 6, NO. 6 | www.McGowan.pitt.edu

On June 25, 2007, Dr. Brack Hattler dipped the rear wheel of his bike into Puget Sound near Seattle, WA and began a 3,300 mile trek across America to raise funds and awareness for the American Lung Association’s clinical research, education and advocacy programs. The final destination is the nation’s capital in Washington, D.C. and then on to complete the cross-country ride by dipping the front bike wheel into the Chesapeake Bay.  Dr. Hattler will travel with a group of cyclists composed of approximately 40 riders between the ages of 18-76 who will bike an average of 83 miles per day for 6 and a half weeks.  Read More

What will a typical day on the trip be like?  According to others who have biked for the same cause, after camping on the road for the night, the day begins at 5 AM and riders hit the road by 7 AM.  They typically consume huge amounts of food while traveling and must help prepare meals and do their own bike maintenance.  Dr. Hattler is writing a blog during his trip that will tell us about his own experiences firsthand; the blog is available here.

The annual meeting of the Tissue Engineering International and Regenerative Medicine Society-North American Chapter (TERMIS) was held in Toronto, Canada the week of June 11, 2007. McGowan Institute participation included the presentation of 42 papers, and distribution of Institute fleece jackets to graduate students and post docs. The Institute received 3 awards for poster presentations, and there was substantial press coverage of McGowan papers presented at the meeting. Read More

The McGowan Institute's teams of researchers—led by William Wagner, PhD, Michael Sacks, PhD, and David Vorp, PhD—are getting closer to technologies which will someday repair damaged hearts and veins.

From the labs of Drs. Wagner and Sacks it was recently reported that a patch has been designed to help damaged cardiac tissue recover from a heart attack.  The prototype has been successful in early animal testing and is moving toward potential human use. In a trial with rats that had induced heart attacks, the patch was implanted directly on the damaged part of the heart wall. The regenerated wall was thicker, "with abundant smooth muscle bundles," and healthier, mature heart cells. This biodegradable heart patch may one day prevent the long-term cardiac damage that so many suffer after a heart attack. A next step toward human use has started in an animal trial with pigs—a larger animal with responses more similar to those of people.

In patients with clogged arteries, bypasses usually fail because the replacement veins, which are often nonessential veins taken from another part of the body, aren't up to the job. Veins are accustomed to low blood pressure and low flow, and they don't feel the pulsations of the heart. Arteries, on the other hand, have higher blood flow, higher shear stresses, and they pulsate because of their proximity to the heart. So when veins from the leg are plugged into the arterial environment, they tend to panic. When a vein is implanted into the arterial environment it assumes that it is injured and immediately tries to counteract the problem by thickening. As it thickens, the canal also begins to narrow, and you're right back where you started from... a clogged artery. Researchers in the lab of Dr. Vorp hope to rectify this situation by making implanted veins stronger by first wrapping them in a biodegradable polymer material like the one developed for the Wagner and Sacks' cardiac patch (experimental apparatus at right). It is proposed that once wrapped, the vein may not thicken as much upon exposure to its new, harsher environment. After a few days, the wrap—the vein girdle—degrades allowing the vein to slowly adapt to its new role. Read More

A research team, led by Albert D. Donnenberg, PhD, has successfully isolated and cultured human blood-forming, or hematopoietic, stem cells from fat tissue.  This outcome suggests that they have found another important source of cells for reconstituting the bone marrow of patients undergoing intensive radiation therapy for blood cancers.

Based on previous reports that the “stromal vascular” fraction of fat tissue contains stem cells that give rise to pericytes—cells surrounding small blood vessels—the researchers isolated the stromal vascular fraction from human fat tissue and expanded these cells by growing them in a specialized blood-culturing medium for 21 to 42 days. Read More

Current cancer therapies often succeed at initially eliminating most of the disease, including all rapidly proliferating cells, but are eventually thwarted because they cannot eliminate a small reservoir of multiple-drug-resistant tumor cells, called cancer stem cells, which ultimately become the source of disease recurrence and eventual metastasis.
Now, research by Pitt scientists suggests that for chemotherapy to be truly effective in treating lung cancers, for example, it must be able to target a small subset of cancer stem cells, which they have shown share the same protective mechanisms as normal lung stem cells.

The Pitt researchers, led by Vera Donnenberg, an assistant professor of surgery and pharmaceutical sciences, used cell surface markers and dyes to identify cancer stem cells as well as normal adult stem cells and their progeny in samples obtained from normal lung and lung cancer tissue samples. The scientists identified a very small, rare set of resting cancer stem cells in the lung cancer samples that looked and behaved much like normal adult lung tissue stem cells. Both the cancer and normal stem cells were protected equally by multiple drug resistance transporters, even if the bulk of the tumor responded to chemotherapy.

According to Donnenberg, the very fact that cancers can and do relapse after apparently successful therapy indicates the survival of a drug-resistant, tumor-initiating population of cells in many types of refractory cancers. “Because of the similarities between the way that normal stem cells and cancer stem cells protect themselves, cancer therapies have to be designed specifically to target cancer stem cells while sparing normal stem cells,” she explained. Read More

Green tea, long reported to have beneficent effects on our health, contains herbal agents that could be used to treat inflammatory bladder diseases.  The catechins in green tea—plant metabolites that provide antioxidative properties—protected bladder cells from damage in a recent study of cells in culture.
    
Michael B. Chancellor, MD, a co-investigator in the study, stated, “These results indicate herbal supplements from green tea could be a treatment option for various bladder conditions that are caused by injury or inflammation.”
    
The study tested normal and cancerous bladder cells and exposed them to two major catechin components of green tea.  Both catechins protected cell lines significantly from hydrogen peroxide, a cell killer.  The concentration of the catechins was at a level that could be achieved through normal dietary intake. Read More

Kristie Henchir Burgess was recognized by Pitt Magazine for her development of a breath module she is designing as she works towards her PhD in Bioengineering.  The feature story, which appeared in the Spring 2007 issue of Pitt, highlighted Burgess’s achievements beginning with her selection as Outstanding Senior of the first baccalaureate class of the then newly formed Department of Bioengineering in 2000.
    
Burgess was also awarded a graduate fellowship from The Whitaker Foundation in 2001 which allowed her to begin work on the breath module she is developing using a microfabrication technique.  Burgess is one of the first scientists to attempt lung design with this technology. 
    
She has been guided in her studies by McGowan Institute’s William Federspiel, PhD and William Wagner, PhD.  The breath module has the potential to improve the lives of cystic fibrosis and emphysema patients.  After finishing her final dissertation thesis, Burgess will attempt to attach several breath modules together to create a complete artificial lung.  The final invention will be a cylinder about the size of a plastic cup and will be used externally by those awaiting lung transplants.  Photo courtesy of Pitt Magazine.

The Regenerative Medicine Podcasts for June offer some intriguing topics:

#33 – Michael Sacks, Ph.D.
Dr. Sacks visits Regenerative Medicine Today and shares highlights of his exciting studies on tissue biomechanics. Dr. Sacks’ research interests include:

• Structural constitutive (stress-strain) models for native and engineered heart valve tissues
• Multi-scale experimental studies and finite element simulations
• Measurement and computation of the dynamic heart valve tissue strains and stresses
• Structure-strength relations and constitutive models of tissue engineered materials

#34 – David Baer, Ph.D.
Dr. David Baer visits Regenerative Medicine Today and discusses the programs of the U.S. Army Institute of Surgical Research.  Dr. Baer is the Director of the Research Office at the Institute of Surgical Research in San Antonio, Texas. In the podcast, Dr. Baer discusses:

• Operational medicine; aka sports medicine in the civilian world
• The focus on combat casualty care and traumatic injury
• Interest in Regenerative Medicine to address severe injuries
• The new medical challenges from the current conflict
• The broad scope of the Institute from basic science to clinical studies
• Training and career opportunities at ISR

Visit www.regenerativemedicinetoday.com to keep abreast of the new interviews.

Authors:	Fujimoto KL, Tobita K, Merryman WD, Guan J, Momoi N, Stolz DB, Sacks MS, Keller BB, Wagner WR.
Title:	An elastic, biodegradable cardiac patch induces contractile smooth muscle and improves cardiac remodeling and function in subacute myocardial infarction.
Summary:	Our objective in this study was to apply an elastic, biodegradable polyester urethane urea (PEUU) cardiac patch onto subacute infarcts and to examine the resulting cardiac ventricular remodeling and performance. BACKGROUND: Myocardial infarction induces loss of contractile mass and scar formation resulting in adverse left ventricular (LV) remodeling and subsequent severe dysfunction. METHODS: Lewis rats underwent proximal left coronary ligation. Two weeks after coronary ligation, a 6-mm diameter microporous PEUU patch was implanted directly on the infarcted LV wall surface (PEUU patch group, n = 14). Sham surgery was performed as an infarction control (n = 12). The LV contractile function, regional myocardial wall compliance, and tissue histology were assessed 8 weeks after patch implantation. RESULTS: The end-diastolic LV cavity area (EDA) did not change, and the fractional area change (FAC) increased in the PEUU patch group (p < 0.05 vs. week 0), while EDA increased and FAC decreased in the infarction control group (p < 0.05). The PEUU patch was largely resorbed 8 weeks after implantation and the LV wall was thicker than infarction control (p < 0.05 vs. control group). Abundant smooth muscle bundles with mature contractile phenotype were found in the infarcted myocardium of the PEUU group. The myocardial compliance of the PEUU group was distributed between normal myocardium and infarction control (p < 0.001). CONCLUSIONS: Implantation of a novel biodegradable PEUU patch onto a subacute myocardial infarction promoted contractile phenotype smooth muscle tissue formation and improved cardiac remodeling and contractile function at the chronic stage. Our findings suggest a new therapeutic option against post-infarct cardiac failure.
Source:	J Am Coll Cardiol. 2007 Jun 12;49(23):2292-300

 

PIs:	Billy W. Day, Ph. D. and Jean J. Latimer, Ph.D.
Title:	“Quantitative proteomics of nuclear matrix proteins in novel human ductal carcinoma in situ model systems”
Description:	Background: Ductal carcinoma in situ (DCIS) is the earliest identifiable breast cancer lesion. Because DCIS is a pre-invasive malignancy, a better understanding of if and how it may progress to invasive disease will allow determination of which patients to treat aggressively and avoid unnecessary aggressive procedures. Once determined, these differentially expressed proteins may be used as biomarkers or therapeutic targets, as well as help determine the paths by which normal cells progress to DCIS plus provide a better understanding of breast carcinogenesis and ways to prevent it. Tumor grade, size and presence of necrosis are currently used to make clinical decisions regarding DCIS. These have not proven to be good predictors, however, as low-grade DCIS often progresses to invasive disease. Proteins that hold promise for a better understanding of DCIS are those in the nuclear matrix (NMPs). The nucleus is a cellular landmark in the pathology of cancer. NMPs in part help to determine the nuclear shape and processes, have been identified as informative markers of disease states in a variety of cancers, and their detection in the serum and urine supports investigation of them in DCIS. NMPs have been investigated in invasive breast cancer, and several have been identified as unique to malignant specimens. Investigation of the NMPs in DCIS is therefore warranted. Prof. Latimer has over the past decade derived several unprecedented DCIS- and breast reduction mammoplasty-derived cell lines, generated without the use of transforming agents from clinically well-defined patients. In combination with the Day lab's modern proteomics technologies, we will thoroughly investigate DCIS. The DCIS samples, both invasive and non-invasive, gave rise to cell lines from tumors and nontumor adjacent tissue, and Prof. Latimer also has cell lines derived from contralateral non-diseased breast samples. All of the lines are characterized by karyotype, array-based comparative genomic hybridization, growth rates, breast epithelial markers, and functional DNA repair capacity. Hypothesis: Detectable differences exist between invasive and noninvasive DCIS at the protein level, particularly in the nucleus, and these differences are distinct from those demonstrated at the nucleic acid level. Specific Aims: In this 2-year study, we will characterize these lines by examining their differential protein expression. In Aim 1, we will grow cultures of the various cells in quantities necessary for replete proteomics analyses, isolate NMPs from each, then employ two of our several proteomic techniques, namely difference two dimensional gel electrophoresis (DIGE) and isobaric tags for relative and absolute protein quantitation (iTRAQ), each followed by mass spectrometric protein identification. These two methods offer orthogonal means of quantitation to help verify results. In Aim 2, the results will be further evaluated with Western blotting and RNAi. Study Design: By comparing the DCIS sample with the pathologically normal adjacent tissue, in addition to the contralateral normal breast sample, we will be able to determine markers specifically expressed by DCIS and investigate their role in the disease, including invasiveness. The mammoplasty cultures will be used as truly normal comparative controls. Impact: If we understand the changes in the cells that give rise to DCIS, we may be able to identify the origins of breast cancer and develop preventative agents.
Source:	DOD Synergy Award (only 10 were given) $800,000
Term:	2-year study

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