Rasha Hammamieh

The health benefits of fish oil enriched with high omega-3 polyunsaturated fatty acids (n-3 PUFA) are widely documented. Fish oil as dietary supplements, however, show moderate clinical efficacy, highlighting an immediate scope of systematic in vitro feedback. Our transcriptomic study was designed to investigate the genomic shift of murine brains fed on fish oil enriched diets. A customized fish oil enriched diet (FD) and standard lab diet (SD) were separately administered to two randomly chosen populations of C57BL/6J mice from their weaning age until late adolescence. Statistical analysis mined 1,142 genes of interest (GOI) differentially altered in the hemibrains collected from the FD- and SD-fed mice at the age of five months. The majority of identified GOI (∼40%) encodes proteins located in the plasma membrane, suggesting that fish oil primarily facilitated the membrane-oriented biofunctions. FD potentially augmented the nervous system's development and functions by selectively stimulating the Src-mediated calcium-induced growth cascade and the downstream PI3K-AKT-PKC pathways. FD reduced the amyloidal burden, attenuated oxidative stress, and assisted in somatostatin activation—the signatures of attenuation of Alzheimer's disease, Parkinson's disease, and affective disorder. FD induced elevation of FKBP5 and suppression of BDNF, which are often linked with the improvement of anxiety disorder, depression, and post-traumatic stress disorder. Hence we anticipate efficacy of FD in treating illnesses such as depression that are typically triggered by the hypoactivities of dopaminergic, adrenergic, cholinergic, and GABAergic networks. Contrastingly, FD's efficacy could be compromised in treating illnesses such as bipolar disorder and schizophrenia, which are triggered by hyperactivities of the same set of neuromodulators. A more comprehensive investigation is recommended to elucidate the implications of fish oil on disease pathomechanisms, and the result-driven repositioning of fish oil utilization may revitalize its therapeutic efficacy.

Background: Post-traumatic stress disorder (PTSD) is a severe anxiety disorder that affects a substantial portion of combat veterans and poses serious consequences to long-term health. Consequently, the identification of diagnostic and prognostic blood biomarkers for PTSD is of great interest. Previously, we assessed genome-wide gene expression of seven brain regions and whole blood in a social defeat mouse model subjected to various stress conditions. Results: To extract biological insights from these data, we have applied a new computational framework for identifying gene modules that are activated in common across blood and various brain regions. Our results, in the form of modular gene networks that highlight spatial and temporal biological functions, provide a systems-level molecular description of response to social stress. Specifically, the common modules discovered between the brain and blood emphasizes molecular transporters in the blood-brain barrier, and the associated genes have significant overlaps with known blood signatures for PTSD, major depression, and bipolar disease. Similarly, the common modules specific to the brain highlight the components of the social defeat stress response (e.g., fear conditioning pathways) in each brain sub-region. Conclusions: Many of the brain-specific genes discovered are consistent with previous independent studies of PTSD or other mental illnesses. The results from this study further our understanding of the mechanism of stress response and contribute to a growing list of diagnostic biomarkers for PTSD.

Rationale : Life-threatening experiences, including the observations of severe trauma and/or violence, coupled with feelings of extreme fear and helplessness can result in posttraumatic stress disorder (PTSD). Unpredictability, uncontrollability, and novelty are considered key factors in eliciting and influencing the intensities of the stress responses. Personal coping strategies may affect resilience and susceptibility to stressors and, in PTSD patients, may also affect responses to stressors such as cortisol secretion. Recent interest in PTSD models focuses on the drivers of susceptibility versus resilience factors and the identification of potential targets for prevention and/or treatment of PTSD. Following a traumatic event, most individuals experience at least some symptoms of PTSD. However, many trauma survivors who develop PTSD recover over the course of months. Methods : Systems and integrative biology approaches were applied to characterize the development of PTSD using an animal model of repeated social trauma/stress. Behavioral, physiological, and histopathological consequences of repeated social stress were evaluated using a modified "6 hour box-in-box resident-intruder" model. At the end of the stress episodes, mouse blood samples and organs were collected and brains were dissected into 17 different regions. Transciptomic, metabolomic, proteomic, and epigenomic changes were analyzed using microarrays. Results : Pan-omic analyses of this mouse model that simulate aspects of PTSD revealed that genes involved in axonal guidance signaling, apoptosis, inflammation, corticotropin releasing hormone signaling, synaptic long-term depression, dendritic branching, and cardiac hypertrophy were upregulated in stressed mice compared to the control. Suppressed transcripts were involved in synaptic long-term potentiation, lymphocyte activation, gap junction signaling, and glucocorticoid receptor pathway. Conclusions : We characterized the regulation patterns of genes, metabolites, protein, DNA methylation, and their associated networks in a mouse model of PTSD. These patterns can be used as part of a diagnostic panel for the development of PTSD and for the validation of therapeutic interventions

Context: The estrogen receptor (ER) status in breast cancer plays a major role in the progression and metastatic potential of breast cancer in women. Breast cancer cells lacking the ER are usually more advanced and more difficult to treat than ER+ breast cancer cells. ER- women have more advanced breast cancer at the time of diagnosis than ER+ women. ER- breast cancer cells in women, regardless of age, are more likely to have tumor Grade III or IV with fewer Grade I and II tumor stages combined for each individual stage group. Studies have suggested a strong correlation between fat intake and the elevated risk of ER+ breast cancer cells. Materials and Methods: We studied the role of ER status on the gene expression in breast cancer cells in response to omega-3 and omega-6 fatty acids using microarrays. We have studied gene expression patterns in 8 breast cancer cell lines (4 ER- and 4 ER+) in response to Eicosapentanoic (EPA) and Arachidonic (AA) acids. Statistical Analysis: Analysis of Variance (ANOVA) t-test analysis was carried out to identify genes differentially expressed between the two groups. Results: We identified genes which were significantly correlated with the ER status when breast cancer cells were treated with these fatty acids. Conclusion: We have determined ER-related gene expression patterns in breast cancer cells in response to fatty acids. Additional studies of these biomarkers may enlighten the importance of the ER status on the mechanistic and therapeutic roles of fatty acids in breast cancer.

Background: Anthrax is caused byBacillus anthracisthat produce two exotoxins, lethal toxin and edema toxin. The lethal toxin is composed of the lethal factor (LF) complexed with the cell binding protective antigen (PA₈₃, 83 kDa). Likewise, the edema factor (EF) binds to the PA₈₃to form the edema toxin. Once PA83 is bound to the host cell surface, a furin-like protease cleaves the full-length, inactive protein into 63 kDa and 20 kDa antigens (PA₆₃and PA₂₀). PA₆₃forms a heptamer and is internalized via receptor mediated endocytosis forming a protease-stable pore, which allows EF and LF to enter the cell and exert their toxic effects.Both proteolytically cleaved protective antigens (PA₆₃and PA₂₀fragments) are found in the blood of infected animals. The 63 kDa protective antigen PA₆₃fragment has been thoroughly studied while little is known about the PA₂₀.Methods: In this study we examined the role of PA₂₀using high throughput gene expression analysis of human peripheral blood mononuclear cells (PBMC) exposed to the PA₂₀. We constructed a PA mutant in which a Factor Xa proteolytic recognition site was genetically engineered into the protective antigen PA₈₃to obtain PA₂₀using limited digestion of this recombinant PA₈₃with trypsin.Results: Global gene expression response studies indicated modulation of various immune functions and showed gene patterns indicative of apoptosis via the Fas pathway in a subset of the lymphoid cells. This finding was extended to include observations of increased Caspase-3 enzymatic activity and the identification of increases in the population of apoptotic, but not necrotic cells, based on differential staining methods. We identified a list of ~40 inflammatory mediators and heat-shock proteins that were altered similarly upon exposure of PBMC to either rPA₂₀orB. anthracisspores/vegetative cells.Conclusion: This study shows that the PA₂₀has an effect on human peripheral blood leukocytes and can induce apoptosis in the absence of other PA components.

Adipocyte-fatty acid binding protein (A-FABP) is a 14-15 kDa cytoplasmic protein that binds unesterified fatty acids (FA). It is believed that A-FABP is present in normal cells and disappears in cancer cells. Prostate cancer DU145 cells lack expression of A-FABP. Here, we report that transfection of A-FABP blocked growth of DU145 cells suggesting its role as a tumor suppressor. A-FABP transfected- prostate cancer DU145 cells underwent apoptosis when induced to overexpress A-FABP using an ecdysone-controlled expression system. DU145 cell cultures in complete medium exhibited a maximum of approximately 28% of apoptotic cells after 96 h of exposure to an ecdysone analog, Ponasterone A. We found that the possible mechanisms leading to the observed apoptotic effect may be due, in part, to an overexpression of tumor necrosis factor-alpha (TNF-alpha) and a moderate downregulation of transforming growth factor-alpha (TGF-alpha) in DU145 cells overexpressing A-FABP. The epidermal growth factor receptor (EGFR)/phosphatidyl inositol 3-kinase (PI 3-kinase) signaling pathway was not altered in these cells, suggesting that A-FABP may cause apoptosis by inducing downregulation of essential autocrine growth factors and/or upregulation of pro-apoptotic ones.