Evans Lab
Rhobert W. Evans, PhD, Assistant Professor of Epidemiology
The Chemistry and Nutrition Laboratory in the Department of Epidemiology supports more than 30 studies and collaborates with several universities in the United States plus institutions in Canada, Japan, and Trinidad and Tobago. The laboratory serves as a core facility for the Obesity and Nutrition Research Center at the University of Pittsburgh. Major areas of study include metabolic aspects of cardiovascular disease, diabetes, HIV infection, obesity and pregnancy. Most of the studies involve human subjects but the laboratory does collaborate in a study involving pigs genetically engineered to synthesize omega-3 fatty acids.
The laboratory performs 60,000 tests annually involving 50 analyses measuring adipokines, cytokines, hormones, lipids and vitamins. A broad range of analytical approaches are employed: automated chemistry, capillary gas-chromatography, enzyme-linked immunoassay, high-pressure liquid-chromatography, mass spectrometry and radio-immunoassay.
The laboratory utilizes extensive quality control procedures and has CLIA accreditation. The laboratory participates in proficiency testing programs organized by the CDC and the College of American Pathologists.
The lab occupies 2,000 square feet on the 5th floor of Crabtree and Parran Halls and employs the equivalent of eight research personnel.
Kamboh Lab
M. Ilyas Kamboh, PhD
Professor of Human genetics
The major focus of the lab is to identify genetic factors that either increase or decrease the risk of common diseases of public health importance, with particular emphasis on coronary heart disease (CHD), Alzheimer’s disease (AD) and systemic lupus erythematosus (SLE). A summary of the three major funding activities being carried out in the lab is as follows:
Genetics of high density lipoprotein-cholesterol (HDL-C): Higher levels of plasma HDL-C provide protection against the risk of CHD. Generally, African or African-derived populations have higher HDL-C levels than whites, which may ameliorate the risk of CHD among Africans. Almost 50% of the variation in plasma HDL-C is determined by genetic factors, but the precise identification of underlying genetic factors is unknown. Most previous efforts to identify genes for HDL-C have focused on screening a selected few polymorphisms in candidate genes, which is not optimal. The recent availability of high-throughput DNA sequencing technology provides an excellent tool to build dense marker maps in each gene of interest. The lab is in the process of sequencing about 40 candidate genes from a large number of African and white individuals having extremely high or low levels of HDL-C in order to identify common and rare functional variants.
Genetics of late-onset Alzheimer’s disease (LOAD): Alzheimer’s disease, especially LOAD is a complex multifactorial neurodegenerative disease and a leading cause of dementia among elderly people. Thus far only one major gene (APOE) has been established as a strong susceptible maker that accounts for 20-30% of the LOAD risk. This indicates the involvement of additional genetic factors that alone or in conjunction with the APOE can modify the risk of LOAD. In collaboration with the University of Pittsburgh Alzheimer Disease Research Center, we have collected a large case-control cohort, which is meaningful for powered association studies. The lab is focusing on several biological and positional candidate genes hoping to find relevant functional variants that modify the risk of LOAD.
Genetics of SLE: SLE is the prototypic systemic inflammatory autoimmune disease that affects predominantly younger premenopausal women. The risk of CHD in SLE women is up to 50% higher than in the general population and the conventional risk factors are insufficient to explain this phenomenon. There is strong evidence that genetic actors affect the risk of both SLE and CHD. The lab is using both a candidate gene approach and genome wide association studies to identify relevant functional genes in a SLE case-control sample collected in collaboration with the investigators from the University of Pittsburgh and the Northwestern University from Chicago.
The Human Genetics Laboratory consists of 2,744 square feet of laboratory space, including a walk-in cold room, and contains the standard laboratory equipment to conduct molecular genetics and molecular biology studies. The laboratory is equipped for DNA analysis by PCR, high-throughput genotyping by TaqMan and pyrosequencing technologies; Northern blotting; Western blotting; automated DNA sequencing; cell culture; in vitro mutagenesis; promoter analysis; and analysis of serum samples by isoelectric focusing, SDS-PAGE, ELISA and immunoblotting.
Opresko Lab
Patricia Opresko, PhD
Assistant Professor of Environmental and Occupational Health
By 2030 the number of individuals over the age of 65 is estimated to double. As the population ages the need to understand the impact that environmental exposures may have on older individuals will also increase. It has been suggested that older individuals may be more susceptible to genotoxic and mutagenic environmental agents due to potential decreases in reserves or the capacity to repair DNA.
Maintenance of the genome is critical for the survival and health of an organism. Genomic mutations and alterations promote cancer, and the incidence of cancer increases exponentially with age. My lab is investigating the mechanisms of genomic instability associated with aging and diseases related to aging.
Telomeres are a region of the genome that profoundly influence life span, human disease and genome integrity. Human telomeres are protein-DNA structures that preserve chromosome ends and limit the replicative potential of somatic cells. The primary focus in recent years has been on mechanisms that lengthen telomeres, such as the enzyme telomerase. However, unlike germ cells, most human somatic and adult stem cells lack sufficient telomerase to prevent telomere attrition that naturally occurs with cell division and age. Shortened telomeres are more vulnerable to de-protection, which triggers cell death, irreversible growth arrest, or can lead to genomic instability and chromosomal aberrations. This is thought to contribute to tissue demise in aging.
We believe the telomeres represent an important protective “reserve” that is depleted as an individual ages. Identifying genetic and environmental factors that cause accelerated telomere loss may aid in the identification of populations that are at risk for the premature onset of aging related diseases. Our hope is that understanding mechanisms of telomere loss and of cellular processes that preserve telomeric DNA, will also lead to the design of intervention therapies that prevent or delay the onset ageing-associated diseases and cancer.
Increased loss of telomeric DNA and telomere dysfunction has been observed in several diseases associated with aging, in human progeroid (premature aging) syndromes, and after oxidative stress. We are interested in identifying genetic and environmental factors that alter normal rates of telomere attrition. Such factors may be linked to increased risks for premature aging based on the observations that shortened telomeres are associated with numerous aging related diseases including cancer, cardiovascular disease, atherosclerosis, rheumatoid arthritis, and pulmonary fibrosis. Furthermore, shortened telomeres are associated with smoking and obesity.
A large body of literature indicates that oxidative stress-induced DNA damage contributes greatly to rates of telomere erosion, and we would like to understand the mechanism. While reactive oxygen species (ROS) from normal metabolism are likely sources of genetic damage and mutations that accumulate with age, there are numerous environmental sources that may also contribute. We are most interested in the potential role that mutagenic environmental metals may have in telomeric DNA loss based on their ability to induce ROS.
Furthermore, we would like to understand cellular pathways that repair and restore damaged telomeric DNA. Currently, we are working towards defining the roles that the DNA repair protein WRN has in preserving telomeres. Loss of WRN protein results in the human progeroid disorder Werner syndrome, which is characterized by the premature onset of cataracts, osteoporosis, atherosclerosis, type II diabetes mellitus, and cancer. Previous studies indicate that WRN protein is important for preventing deletions and loss of telomeres, and that dysfunctional telomeres contribute to the disease pathology.
Our working hypothesis is that unrepaired damage to telomeric DNA contributes directly to telomeric DNA deletions and loss, and that WRN protein preserves telomeres by preventing and/or repairing breaks in telomeric regions of the genome. The guanine rich repeats in telomeric DNA sequence make it highly susceptible to the formation of bulky structures (G-quadruplexes) and oxidative base damage that can hinder DNA replication and lead to telomeric breaks and deletions. We propose that WRN protein may prevent deletions during replication of telomeric DNA by resolving blocks to the replication machinery that occur spontaneously or from oxidative damage. My lab is using complementary biochemical and cellular assays to define the mechanisms of increased telomere loss associated with premature aging and oxidative stress, and to define roles for repair enzymes in preserving telomeres.