Major Grants in 2005

Title: Effects of Intracellular Angiotensin II Grant Number: 1 R01 HL072795-01A2

Time Period: 2005-2010 Direct Costs: $1M

Principal Investigator: Julia L. Cook, PhD

Collaborator: Richard N. Re, MD

Dr. Julia Cook, co-director of the Molecular Genetics Laboratory/Hypertension staff, was recently awarded an R01 grant for $1M in direct costs from the National Institutes of Health, for years 2005-2010, to study the intracellular renin-angiotensin system.

The classic view of angiotensin II (AII), the primary biologically active component through which the renin-angiotensin system mediates hemodynamic and electrolyte effects, is that it functions as a blood-borne hormone. In the last decade, it has become increasingly clear that AII can be generated in tissues, act as a local hormone, and confer autocrine and/or paracrine effects. Our published studies (Circ Res, 2001; J Mol Cell Cardiol, 2002; J Mol Cell Cardiol, 2004; J Mol Cell Cardiol, 2006) show that expression of intracellular AII stimulates cell growth and that the growth stimulation is accompanied by cAMP response element-binding protein (CREB) phosphorylation and PDGF A-chain upregulation. This application proposes to extend these studies to generate mice transgenic for two different expression cassettes directing intracellular AII production. In addition, we will cross the transgenic mice with null-angiotensinogen mice to determine whether intracellular expression of Aogen (angiotensinogen) and subsequent intracellular generation of AII can compensate for an absence of extracellular AII and, thus, reverse the kidney and blood pressure phenotypes of the knockout mice.

These studies will apply a cDNA construct which we have designed to encode a form of Aogen, devoid of the signal sequence (which directs secretion), but possessing an intact AI/AII-encoding region. This modified Aogen is growth stimulatory for H4-II-E-C3 rat hepatoma cells. These studies will likewise apply an intracellular fluorescent fusion protein of AII that we have shown to stimulate growth and CREB phosphorylation in cells expressing AT1 receptor fusion proteins. Both exogenous AII and intracellular AII induce AT1R trafficking to cell nuclei; the receptor trafficking pathway for each will be established.

We will identify and compare kinase pathways responsible for CREB phosphorylation following intracellular versus extracellular AII stimulation. Collectively, these studies will define the relative roles and relative importance of intracellular and extracellular AII, and the potential for internalization or intracellular generation of AII in vivo in unmanipulated systems.

Our studies to date argue in favor of functional partitioning of AII/AT1R effects. Extracellular AII may primarily mediate short-term acute hemodynamic effects while intracellular AII/AT1R interactions may contribute to long-term chronic hyperplasia, hypertrophy, cell migration and extracellular matrix production. The intracellular AII effects may have greater long-term maladaptive cardiovascular consequences and targeting the intracellular system may require therapies alternative to those used to target the conventional renin-angiotensin system.

Title: Stromal Cell Molecules Required for

Lymphoma Generation

Grant Number: 5R01CA089057-05 Time Period: 2001–2006

Direct Costs: $0.77M

Principal Investigator: Li Li, MD, PhD

Dr. Li Li, associate director of the Cellular Immunology Laboratory, has been awarded a $0.77M R01 grant in direct costs from the National Institutes of Health for the continuation of her ongoing studies to identify stromal cell molecules involved in the generation and growth of lymphomas.

In the early stage, follicular lymphoma, one of the most common hematological malignancies in adults, is usually indolent, regressing spontaneously and showing susceptibility to chemotherapy. However, this tumor often recurs and can undergo blast transformation to an aggressive form, ultimately becoming a fatal disease. The generation and blast transformation of this tumor occur in close association with follicular dendritic cells (FDC) in the germinal center (GC). The objective is to identify the FDC signaling molecules by preparing the FDC-specific monoclonal antibodies that block FDC-mediated lymphoma cell proliferation in vitro and in vivo, and then use these antibodies to clone the genes of the signaling molecules from cDNA library of an FDC line, HK. The functions of the cloned genes will be investigated by expressing them in COS cells and evaluating them in in vitro and in vivo experimental models. A human lymphoma cell line of GC-origin, L3055, will be used, because growth of this cell line depends on FDC/HK in vitro and in vivo. Identification of the stromal cell molecules required for the growth of the lymphomageneses will lead to development of antagonists. Such antagonists may have a tremendous therapeutic potential to suppress the growth of malignant lymphomas or other tumors that metastasized to lymphoid follicles.

Title: Cohort Study of Medication Adherence among

Older Adults

Grant Number: R01 AG022536 Time Period: 2005–2009

Direct Costs: $1.55M

Principal Investigator: M. A. Krousel-Wood, MD, MSPH

Collaborating Investigators: Richard N. Re, MD,

Edward D. Frohlich, MD, Paul Muntner, PhD – Tulane,

Larry Webber, PhD – Tulane, Don Morisky, ScD - UCLA

Dr. Marie A. “Tonette” Krousel-Wood, principal investigator, was recently awarded a $1.55M RO1 grant in direct costs from the National Institutes of Health for 2005–2009 to conduct a prospective cohort study among aging adults (≥65 years) with essential hypertension (HTN) in a managed care setting is to investigate the multiple factors that influence anti-hypertensive medication adherence.

Hypertension is often an asymptomatic chronic medical condition which calls for persistent adherence to medication regimes to reduce the risks of stroke, cardiovascular and renal disease. Despite the availability of effective medical therapy for hypertension, only 31% of persons with HTN have controlled blood pressure. One key factor contributing to poor blood pressure control is patient non-adherence to prescribed therapy. With adherence rates for medications estimated at about 50%, there is a continued lack of understanding of why adherence rates are low.

Dr. Krousel-Wood and her collaborators from Ochsner (Drs. Richard Re and Edward Frohlich), Tulane (Drs. Paul Muntner and Larry Webber) and UCLA (Dr. Don Morisky) will assess psychosocial, behavioral, quality of life, sexual function, medication class, and clinical factors measured at baseline on subsequent change in anti-hypertension medication adherence over 2 years of follow-up. In addition, health care system issues (perception of one's primary care provider, copayments and benefits, satisfaction with access, and communication), use of prescribed, over-the-counter, and unconventional medications and lifestyle modifications on anti-hypertensive medication adherence and change in adherence will be evaluated. Lastly, the relationship of anti-hypertensive medication adherence at baseline with future outcomes including blood pressure control, cardiovascular disease incidence and all-cause mortality, quality of life, and utilization will be evaluated.

Results of this study will lay the groundwork for developing interventions to improve medication adherence and clinical outcomes in older adults with hypertension and will increase our understanding of factors contributing to therapeutic outcomes in the use of medications by these patients.