Distinct Biological Network Properties between the Targets of Natural Products and Disease Genes

We show that natural products target proteins with a high number of protein−protein functional interactions (high biological network connectivity) and that these protein targets have higher network connectivity than disease genes. This feature may facilitate disruption of essential biological pathways, resulting in competitor death. This result also suggests that additional sources of small molecules will be required to discover drugs targeting the root causes of human disease in the future.Chemistry and Chemical Biolog

Multiplex Cytological Profiling Assay to Measure Diverse Cellular States

Computational methods for image-based profiling are under active development, but their success hinges on assays that can capture a wide range of phenotypes. We have developed a multiplex cytological profiling assay that “paints the cell” with as many fluorescent markers as possible without compromising our ability to extract rich, quantitative profiles in high throughput. The assay detects seven major cellular components. In a pilot screen of bioactive compounds, the assay detected a range of cellular phenotypes and it clustered compounds with similar annotated protein targets or chemical structure based on cytological profiles. The results demonstrate that the assay captures subtle patterns in the combination of morphological labels, thereby detecting the effects of chemical compounds even though their targets are not stained directly. This image-based assay provides an unbiased approach to characterize compound- and disease-associated cell states to support future probe discovery

PhD

dissertationLyme disease is caused by the spirochete Borrelia burgdorferi and if left untreated, often causes arthritis. The spirochetes possess outer surface lipoproteins (Osps) that are capable of stimulating inflammatory cytokine production from B cells, macrophages, and endothelial cells, and the production of nitric oxide (NO). The role of NO during infection of mice with B. burgdorferi was investigated. Both the severely arthritic (C3H) and mildly arthritic (BALB/c) mice produced high levels of NO approximately 7 days after infection, but C3H animals rapidly downregulated NO production to background levels, whereas BALB/c animals sustained NO production throughout the course of infection. Complete inhibition of NO production by the compound N[G]-monomethyl-L-arginine (LMMA) during infection had no significant effect on either arthritis development or spirochete numbers in tissues. These results indicate that NO is ineffective at controlling spirochete numbers in tissues, and, therefore, B. burgdorferi probably does not require an intracellular localization for survival in the mammalian host. The reproducible downregulation of NO in C3H animals may be induced by anti-inflammatory cytokines which could modulate other aspects of the immune response to B. burgdorferi. In vitro studies showed that OspA could stimulate IL-10 production by naive murine splenocytes and that physiological concentrations of IL-10 could significantly downregulate the responses of OspA-treated macrophages. The inappropriate or uncontrolled production of IL-10 during infection could result in dysregulation of host defenses, thus leading to the development of pathology. The Osps also stimulate adhesion molecule expression on cells. The role of two adhesion molecules, E-selectin and P-selectin, in the development of Lyme arthritis, was investigated by infecting mice lacking both molecules with B. burgdorferi and assessing arthritis development and spirochete number. Mice lacking E- and P-selectin showed resistance to arthritis development and spirochete numbers virtually identical to their wild-type littermates, indicating that these adhesion molecules are not required for resistance to Lyme arthritis. Additionally, a correlation between influx of neutrophils into joints and arthritis severity was noted, indicating that neutrophil infiltration into joints may be required for the development of arthritis. These studies may aid in the determination of pathogenic mechanisms in Lyme arthritis

Distinct Biological Network Properties between the Targets of Natural Products and Disease Genes

We show that natural products target proteins with a high number of protein−protein functional interactions (high biological network connectivity) and that these protein targets have higher network connectivity than disease genes. This feature may facilitate disruption of essential biological pathways, resulting in competitor death. This result also suggests that additional sources of small molecules will be required to discover drugs targeting the root causes of human disease in the future