Daniel L. Greenberg, Ph.D. - US grants

Factor VII is a vitamin K dependent protein which associates with Tissue Factor and initiates the extrinsic pathway of coagulation. Elevated plasma levels of Factor VII may be an independent risk factor for ischemic heart disease, and have been associated with other hypercoagulable states. This proposal is designed to identify and characterize the transcriptional regulatory and termination regions of the factor VII gene, followed by the purification and characterization of novel transcription factors. The experimental approach can be outlined in the following steps: I. DNA STUDIES A. Characterization of the factor VII promoter. l. Functional reporter gene assays of the promoter region. 2. Deletion mutagenesis of the promoter region. 3. Orientation and positional effects of the promoter. 4. DNase I footprinting and methylation interference studies. 5. Site-directed mutagenesis of promoter sequences. B. Search for additional regulatory elements. l. Extend 5'-flanking untranslated sequence by chromosome walking. 2. Reporter gene constructs with the first intron of the factor VII gene. II. DETERMINATION OF THE TRANSCRIPTION TERMINATION REGION: By northern analysis of cellular mRNA transcripts derived from reporter gene constructs. III. PURIFICATION AND CHARACTERIZATION OF TRANSCRIPTION FACTORS A. Development of gel-shift assay to identify optimal conditions for DNA-binding. B. UV cross-linking studies to identify the factor(s) which interact with the promoter sequences. C. DNA-affinity chromatography. D. cDNA cloning and expression of the transcriptional factor(s) The characterization of the transcriptional regulatory region and the isolation of their sequence-specific nuclear factors will expand our current understanding of tissue-specific gene regulation. This information may also help determine if the vitamin K-dependent coagulation proteins are regulated by a common nuclear factor(s) and may give insight into the molecular events which trigger the elevation of plasma levels of factor VII in hypercoagulable states such as ischemic heart disease.

DESCRIPTION (provided by applicant): Many clinical disorders involve impairments of autobiographical memory, including depression, post-traumatic stress disorder, Alzheimer's disease, and stroke. According to one model, these memories require multiple brain regions and cognitive processes; this study will help identify them. Participants will undergo FMRI scanning while retrieving autobiographical memories in response to cue words. After recalling each memory, they will rate several of its properties (such as emotional intensity) on a series of scales. Two types of analysis will be conducted: first, activation during the search for a memory will be compared to activation during retrieval; second, memories that are rated high on one property will be compared to those that are rated low on that property.

DESCRIPTION (provided by applicant): Semantic dementia, otherwise known as the temporal variant of frontotemporal dementia, is characterized by a progressive loss of semantic memory, or general knowledge about the world. Afflicted patients gradually lose the ability to identify objects, people, and ideas. Some research has shown that the disorder also affects autobiographical memory--in other words, memories for everyday life-but the nature, extent, and neuroanatomical substrate of this loss are not well understood. Specifically, some research has shown that the memory loss in semantic dementia is temporally graded-that is, recent memories are recalled better than remote memories. These studies have primarily used verbal cues, however, and we do not yet know whether other cues might prove more effective. To this end, we will cue participants' autobiographical memories using words, pictures and odors. Odors are chosen because they are a particularly good cue for early autobiographical memories (which are just the memories lost in semantic dementia) and they depend upon medial temporal regions that are intact in semantic dementia. In addition, we will conduct a longitudinal study of semantic dementia to characterize the rate and extent of memory decline. Overall, an investigation of the effects of modality, both in cross-sectionally and longitudinally, will help us understand the role of the anterolateral temporal cortex in memory, the relation between semantic and episodic memory, and the precise nature of the autobiographical memory deficit in semantic dementia.