👤 Sarah K Savage

Investigating the genetic underpinnings of functional brain connectivity is essential to understand how genetic variation influences brain health and disease. Here, a mass-univariate approach was adopted to study the genetic architecture of functional brain circuitry (N Show less

Alcohol consumption across the lifespan contributes to mood fluctuations and cognitive dysfunction, two neurobehavioral features also associated with Alzheimer's Disease and Related Dementias (ADRD). Yet, few studies have used rodent models to determine how a history of ethanol consumption across the lifespan might contribute to neurobehavioral and neuropathological features of ADRD. We exposed Wild Type (WT) and transgenic Fischer 344 CE rats (TgF344-AD) that have been genetically modified to express the human Amyloid Precursor Protein (APP) and presenilin-1 genes with mutations, to ethanol using a chronic, intermittent ethanol consumption model. Beginning at P28, rats were given a single bottle 10 % ethanol solution for 2 consecutive days, followed by 2 days of tap water. This pattern (2 days on, days off) was repeated for a total of 12 cycles until rats reached the age of ∼ 3 months, and repeated at 6 (Exp 1 and Exp 2) and 9 months of age (Exp 2). In experiment 1, ethanol consumption decreased alternations in a spontaneous alternation task in females, only at the 3-month time point, whereas TgF344-AD females showed increased contextual fear conditioning in the test of retention and reinstatement tests at 6 months of age. In experiment 2, a battery of anxiety-like behaviors (Elevated Plus Maze, Marble Burying, and Novelty Induced Hypophagia) were assessed following a 2-week abstinence period at 3, 6, and 9 months of age in ethanol-consuming rats. Data from the EPM and marble burying tasks revealed evidence of heightened anxiety-like behavior in Tg-F344-AD rats that varied by sex and age, with no significant effects of ethanol. In the novelty-induced hypophagia task, males with a history of ethanol consumption had a lower latency to approach a familiar, salient reward at 3 months old, but effects of ethanol were overall minimal. Examination of dorsal hippocampal gene expression at 6 months of age under basal conditions also revealed predominantly genotype and sex-specific effects on inflammation- and AD-related genes (App, Il-6, Bace1, Rage, Lrp-1). When examined at 9 months old following LPS challenge, ethanol increased inflammatory genes in males (Il-1β, Il-6) in the hippocampus, whereas ethanol decreased several inflammatory and AD-related genes (Hmgb1, Rage, Bace1, Lrp-1) in TgF344-AD females. Overall, these data provide further evidence that females are especially vulnerable to AD, and that a history of ethanol consumption had selective, rather than global, effects on AD- and inflammation-related genes following an inflammatory stimulus. Show less

Many emerging service delivery models triage genetic counselor time with patients to postgenetic testing, including population genomic screening followed by genetic counseling (GC). To prime patients and help genetic counselors tailor such visits, a previsit (PV) chatbot was created to assess patient understanding, emotional response to, and family communication about genetic results. This study explored patients' perceptions of the PV chatbot and how they would use it. User testing was conducted via videoconference with patients who had completed GC. A codebook thematic analysis informed by Proctor's Conceptual Model of Implementation Research in a postpositivist paradigm was conducted. In total, 16 participants completed user testing, of whom 12 were women and 4 were men with a mean age of 55.4 (range 32-69). Participants had a variety of genetic results out of 78 genes among cancer (PMS2 n = 2; PALB2 n = 4; BRCA2 n = 1) and cardiovascular (LDLR n = 1; MYBPC3 n = 1; DSP n = 1; TTN n = 5; MYH7 n = 1) conditions. Participants reported high acceptability (M = 4.53/5, SD = 0.45) and feasibility (M = 4.43/5, SD = 1.04) of the chatbot. Participants reported liking the chatbot because of its ease of use and anticipated benefit to GC. Participants viewed the chatbot as complementary to GC and shared that the chatbot would have helped prepare them for GC in ways they may not have considered, including inviting a family member to join the appointment. Participants desired more personalization within the chatbot, including responsiveness to their personal/family history, optional supplementary education, and more emotionally supportive language. Some participants described challenges with certain aspects of the chatbot, including the repetitiveness and phrasing of validated scaled measures. Overall, participants perceived the PV chatbot to be of value in educating and preparing them for GC and reflected on how the PV chatbot may have enhanced GC. Many of the perceived benefits of this chatbot are applicable across GC settings. Show less

This study examined dark microglia-a state linked to central nervous system pathology and neurodegeneration-during postnatal development in the mouse ventral hippocampus, finding that dark microglia interact with blood vessels and synapses and perform trogocytosis of pre-synaptic axon terminals. Furthermore, we found that dark microglia in development notably expressed C-type lectin domain family 7 member A (CLEC7a), lipoprotein lipase (LPL) and triggering receptor expressed on myeloid cells 2 (TREM2) and required TREM2, differently from other microglia, suggesting a link between their role in remodeling during development and central nervous system pathology. Together, these results point towards a previously under-appreciated role for dark microglia in synaptic pruning and plasticity during normal postnatal development. Show less

Protein synthesis is frequently dysregulated in cancer and selective inhibition of mRNA translation represents an attractive cancer therapy. Here, we show that therapeutically targeting the RNA helicase eIF4A with zotatifin, the first-in-class eIF4A inhibitor, exerts pleiotropic effects on both tumor cells and the tumor immune microenvironment in a diverse cohort of syngeneic triple-negative breast cancer (TNBC) mouse models. Zotatifin not only suppresses tumor cell proliferation but also directly repolarizes macrophages toward an M1-like phenotype and inhibits neutrophil infiltration, which sensitizes tumors to immune checkpoint blockade. Mechanistic studies revealed that zotatifin reprograms the tumor translational landscape, inhibits the translation of Sox4 and Fgfr1, and induces an interferon (IFN) response uniformly across models. The induction of an IFN response is partially due to the inhibition of Sox4 translation by zotatifin. A similar induction of IFN-stimulated genes was observed in breast cancer patient biopsies following zotatifin treatment. Surprisingly, zotatifin significantly synergizes with carboplatin to trigger DNA damage and an even heightened IFN response, resulting in T cell-dependent tumor suppression. These studies identified a vulnerability of eIF4A in TNBC, potential pharmacodynamic biomarkers for zotatifin, and provide a rationale for new combination regimens consisting of zotatifin and chemotherapy or immunotherapy as treatments for TNBC. Show less

Protein synthesis is frequently dysregulated in cancer and selective inhibition of mRNA translation represents an attractive cancer therapy. Here, we show that therapeutically targeting the RNA helicase eIF4A by Zotatifin, the first-in-class eIF4A inhibitor, exerts pleiotropic effects on both tumor cells and the tumor immune microenvironment in a diverse cohort of syngeneic triple-negative breast cancer (TNBC) mouse models. Zotatifin not only suppresses tumor cell proliferation but also directly repolarizes macrophages towards an M1-like phenotype and inhibits neutrophil infiltration, which sensitizes tumors to immune checkpoint blockade. Mechanistic studies revealed that Zotatifin reprograms the tumor translational landscape, inhibits the translation of Show less

In this study we aimed to establish the genetic cause of a myriad of cardiovascular defects prevalent in individuals from a genetically isolated population, who were found to share a common ancestor in 1728. Trio genome sequencing was carried out in an index patient with critical congenital heart disease (CHD); family members had either exome or Sanger sequencing. To confirm enrichment, we performed a gene-based association test and meta-analysis in two independent validation cohorts: one with 2685 CHD cases versus 4370 . These controls were also ancestry-matched (same as FTAA controls), and the other with 326 cases with familial thoracic aortic aneurysms (FTAA) and dissections versus 570 ancestry-matched controls. Functional consequences of identified variants were evaluated using expression studies. We identified a loss-of-function variant in the Notch target transcription factor-encoding gene HEY2. The homozygous state (n = 3) causes life-threatening congenital heart defects, while 80% of heterozygous carriers (n = 20) had cardiovascular defects, mainly CHD and FTAA of the ascending aorta. We confirm enrichment of rare risk variants in HEY2 functional domains after meta-analysis (MetaSKAT p = 0.018). Furthermore, we show that several identified variants lead to dysregulation of repression by HEY2. A homozygous germline loss-of-function variant in HEY2 leads to critical CHD. The majority of heterozygotes show a myriad of cardiovascular defects. Show less

Cardiovascular (CV)- and lifestyle-associated risk factors (RFs) are increasingly recognized as important for Alzheimer's disease (AD) pathogenesis. Beyond the ε4 allele of apolipoprotein E (APOE), comparatively little is known about whether CV-associated genes also increase risk for AD. Using large genome-wide association studies and validated tools to quantify genetic overlap, we systematically identified single nucleotide polymorphisms (SNPs) jointly associated with AD and one or more CV-associated RFs, namely body mass index (BMI), type 2 diabetes (T2D), coronary artery disease (CAD), waist hip ratio (WHR), total cholesterol (TC), triglycerides (TG), low-density (LDL) and high-density lipoprotein (HDL). In fold enrichment plots, we observed robust genetic enrichment in AD as a function of plasma lipids (TG, TC, LDL, and HDL); we found minimal AD genetic enrichment conditional on BMI, T2D, CAD, and WHR. Beyond APOE, at conjunction FDR < 0.05 we identified 90 SNPs on 19 different chromosomes that were jointly associated with AD and CV-associated outcomes. In meta-analyses across three independent cohorts, we found four novel loci within MBLAC1 (chromosome 7, meta-p = 1.44 × 10 Show less

Pharmacological enhancers of lipoprotein lipase (LPL) are in preclinical or early clinical development for cardiovascular prevention. Studying whether these agents will reduce cardiovascular events or diabetes risk when added to existing lipid-lowering drugs would require large outcome trials. Human genetics studies can help prioritize or deprioritize these resource-demanding endeavors. To investigate the independent and combined associations of genetically determined differences in LPL-mediated lipolysis and low-density lipoprotein cholesterol (LDL-C) metabolism with risk of coronary disease and diabetes. In this genetic association study, individual-level genetic data from 392 220 participants from 2 population-based cohort studies and 1 case-cohort study conducted in Europe were included. Data were collected from January 1991 to July 2018, and data were analyzed from July 2014 to July 2018. Six conditionally independent triglyceride-lowering alleles in LPL, the p.Glu40Lys variant in ANGPTL4, rare loss-of-function variants in ANGPTL3, and LDL-C-lowering polymorphisms at 58 independent genomic regions, including HMGCR, NPC1L1, and PCSK9. Odds ratio for coronary artery disease and type 2 diabetes. Of the 392 220 participants included, 211 915 (54.0%) were female, and the mean (SD) age was 57 (8) years. Triglyceride-lowering alleles in LPL were associated with protection from coronary disease (approximately 40% lower odds per SD of genetically lower triglycerides) and type 2 diabetes (approximately 30% lower odds) in people above or below the median of the population distribution of LDL-C-lowering alleles at 58 independent genomic regions, HMGCR, NPC1L1, or PCSK9. Associations with lower risk were consistent in quintiles of the distribution of LDL-C-lowering alleles and 2 × 2 factorial genetic analyses. The 40Lys variant in ANGPTL4 was associated with protection from coronary disease and type 2 diabetes in groups with genetically higher or lower LDL-C. For a genetic difference of 0.23 SDs in LDL-C, ANGPTL3 loss-of-function variants, which also have beneficial associations with LPL lipolysis, were associated with greater protection against coronary disease than other LDL-C-lowering genetic mechanisms (ANGPTL3 loss-of-function variants: odds ratio, 0.66; 95% CI, 0.52-0.83; 58 LDL-C-lowering variants: odds ratio, 0.90; 95% CI, 0.89-0.91; P for heterogeneity = .009). Triglyceride-lowering alleles in the LPL pathway are associated with lower risk of coronary disease and type 2 diabetes independently of LDL-C-lowering genetic mechanisms. These findings provide human genetics evidence to support the development of agents that enhance LPL-mediated lipolysis for further clinical benefit in addition to LDL-C-lowering therapy. Show less

Patients with various hematologic malignancies, including acute lymphoblastic leukemia (ALL), acute myeloblastic leukemia (AML), diffuse histiocytic lymphoma, and granulocytic sarcoma, have sometimes been shown to carry the PICALM-MLLT10 fusion gene (alias CALM-AF10) by various cytogenetic methodologies. Cases with the PICALM-MLLT10 fusion gene can involve a diagnostic dilemma for the following reasons: (1) the fusion gene occurs very rarely, (2) the cases do not have a distinct myeloid or lymphoid morphology and cells often appear immature, (3) cases usually have a mixed T-cell and myeloid phenotype, and (4) cases often have a mixed clinical presentation (e.g., mediastinal mass in a patient with AML). A 27-year-old woman was diagnosed with AML with the PICALM-MLLT10 fusion gene. The patient was treated on an AML regimen and achieved a complete remission. Although the reported treatment of these patients varies greatly, outcome remains very poor in the vast majority. Furthermore, central nervous system involvement at diagnosis and relapse are reported in pediatric populations. Routine acute leukemia fluorescence in situ hybridization panels do not include a probe for the PICALM-MLLT10 fusion gene, and therefore diagnosis can be made only when karyotyping is available; that delay can result in initial misdiagnosis and mistreatment. The case report and literature review here (including discussion of the poor prognosis and of management, including CNS prophylaxis) are intended to raise awareness and to inform about PICALM-MLLT10 in acute leukemia. Show less