Emory University School of Medicine
Emory University School of Medicine
Department of Medicine

Specialized Center of Research Excellence on Sex Differences (SCORE) section navigation

Department of Medicine

SCORE Pilot Projects

2022-2023 SCORE Pilot & Add-an-Aim Projects

Shannon Gourley, PhD

Associate Professor

Emory National Primate Research Center & Department of Pediatrics
Emory School of Medicine

2023 Add-An-Aim Grant Recipient
Base Grant: R01DA044297

INHIBITING P13K P110B TO BLOCK COCAINE - INDUCED HABITS AND DRUG SEEKING
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WHY SEX MATTERS IN SCIENCE:

...Because even though there are higher rates of drug misuse in men, women tend to progress to addiction more rapidly than males and women also experience higher rates of relapse following treatment. This suggests that processes controlling decision-making behavior (e.g., to seek drug or not) could differ between the sexes and we need to better understand potential sex-based physiological causes.

ABSTRACT

Using an animal (mouse) model, we recently discovered, while using site-selective in vivo gene silencing, that the cell adhesion receptor β1-integrin in the OFC is necessary for prospective, goal-directed action in male mice, but unexpectedly, females were resilient to β1-integrin loss5. Integrins are transactivated by Brain-Derived Neurotrophic Factor (BDNF) binding to its high-affinity receptor, tropomyosin receptor kinase B (TrkB), and this transactivation is facilitated by estrogen6. We confirmed that stimulating TrkB in males made them appear "female" in their action selection strategies5. Potentially, TrkB-mediated control of goal-directed action is particularly potent in females.

With SCORE funding, we will ask the following questions: 1) Are females particularly reliant on TrkB in the mOFC for adaptive decision making? 2) Does neurotrophin-dependent action rely on input from the ventral hippocampus (vHC) (in both sexes)? These questions are important because stimuli like stressors and addictive drugs degrade neurotrophin systems in multiple cortical regions7,8,9. Further, TrkB-manipulating pharmacotherapies that augment cortical TrkB activity mollify addiction-related behavior in rodents and have been proposed as treatments in humans10,11, but their efficacy may differ between the sexes

Liliana Aguayo-Markes, PhD, MPH

Assistant Professor

Hubert Department of Global Health
Rollins School of Public Health

2022 Add-An-Aim Grant Recipient
Base Grant: R01DK115937-03S2

DYNAMICS AND HEALTH CONSEQUENCES OF OBESITY BETWEEN INFANCY AND YOUNG ADULTHOOD IN THE UNITED STATES
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WHY SEX MATTERS IN SCIENCE:

...Because we do not yet know whether there are sex-base differences between boys and girls in the trajectories of height and weight gain and risk of incident obesity from childhood to adult ages.

ABSTRACT

Dual group-based trajectory modeling will be used to identify similar underlying trajectories of simultaneous height and weight gain from birth to age 35 for boys and girls separately. Group-based trajectory modeling is an individual-based, empirical approach that takes advantage of hierarchical modeling and latent growth curve modeling to analyze developmental trajectories and develop latent class growth curves. These models assume the population is made of unobservable subgroups that share similar growth trajectories and allow us to identify the trajectories and estimate the probability of trajectory membership.

Sex specific group-based trajectory models will be used first to estimate dual trajectories, adjusting for the effect of race/ethnicity, US Census region, level of urbanization and socioeconomic status. The second set of dual trajectory models will stratify by sex and race/ethnicity to examine different growth patters among White, Black, Hispanic, and Asian boys and girls (n=6strata/ sets of trajectories).

Once trajectories are identified, the posterior predicted probability (PPP) of being a member in each of the classes for each individual will be estimated. Participants will be assigned to the trajectory group for which they have the greatest PPP. Significant geographic predictors (rurality and regions) will be used to further examine the dual trajectories stratifying by significant geographic factors. These tests will allow us to recognize any potential differences in growth by sex that may be taking place at different geographic levels.

Outcomes from this study will expand the base grant project and introduce a current characterization of height and weight gain trajectories by sex and race/ ethnic group across different levels of urbanization and US regions.

Together, these studies will support the development of two grant applications: 1) The R21 application that will propose to expand the synthetic cohort to examine the dynamics of weight gain and neurodevelopmental trajectories from early life, and their association with cardiometabolic risks. 2) The R01 proposal aims to examine the etiology of cardiovascular disease risks and protective factors among children born to US and immigrant mothers using data from our synthetic cohort and additional datasets, and accounting for sex differences from birth.

Rebecca Levit

Assistant Professor

Department of Cardiology
Emory School of Medicine

2022 Add-An-Aim Grant Recipient
Base Grant: R01HL140223

THE REGULATION OF NEUTROPHIL EXTRACELLULAR TRAPS (NETS) BY ADENOSINE IN MYOCARDIAL ISCHEMIA-REPERFUSION
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WHY SEX MATTERS IN SCIENCE:

... Because neutrophil extracellular traps (NET) formation has been shown to be associated with systemic lupus erythematosus, which is 9 times more common in women compared to men; with cardiovascular disease, which has more severe outcomes in women compared to men; and in other diseases which are more common or more severe in women but the the factors regulating NETosis are not well understood, especially in regards to biological sex differences between males and females.

ABSTRACT

Sex-based differences in diseases linked to NETosis are intriguing and hint at important mechanistic underpinnings. In fact, there are many differences in the immune system between males and females. In humans, females are less susceptible to viral infections such as influenza, hepatitis, and HIV but have more severe disease when infected. Females have higher expression of pattern recognition receptors, antiviral gene responses, and antibody and cell-mediated response to antigens and vaccines. Some of these differences are mediated by sex hormone receptors on immune cells influencing the transcription of cytokines and chemokines. Several key differences have been defined between male and female derived neutrophils. Neutrophils from males have markers of a more immature state including higher oxygen consumption and mitochondria. Female neutrophil have a higher type I interferon response signature, and important inflammatory pathway linked to anti-viral defense. Thus it is reasonable to hypothesize that there are male-female differences in NETosis.

As NET-related illnesses are more common in women, identifying sex-specific differences is key to identification of effective treatment strategies and surveillance diagnostic tests. These observations have led us to hypothesize the existence of sex-specific NET-regulatory pathways that could explain some of the burden of inflammatory diseases that differentially effect women. In this proposal, we will combine our expertise in neutrophil biology with sophisticated transcriptomic techniques to specifically investigate genes and pathways responsible for regulation of NETs in women.

Sheela Sinharoy, PhD

Assistant Professor

Hubert Department of Global Health
Rollins School of Public Health

2022 Add-An-Aim Grant Recipient
Base Grant: OPP1191625 (Bill & Melinda Gates Foundation)

MEASURING URBAN SANITATION AND EMPOWERMENT (MUSE)
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WHY SEX MATTERS IN SCIENCE:

...Because heavy menstrual bleeding (HMB), defined as excessive blood loss leading to interference with the physical, emotional, social, and material quality of life of a woman, is a known risk factor for anemia but the relative contribution of HMB to the anemia burden in low- and middle-income countries has never been explored in detail.

ABSTRACT

No validated survey instrument exists for measuring HMB in LMICs. Instruments developed in high-income countries may not be suitable for use in LMICs given that many include references to sanitary products like tampons and disposable pads, which are not available or used by women in many LMIC settings. Many instruments are also overly time-consuming and/or complex, making them suitable only for clinical settings (6, 7). Therefore, the extent of HMB in LMICs remains largely unknown. A critical need exists for a validated survey instrument to measure HMB in LMIC settings, to define the prevalence of HMB among populations at highest risk of anemia.

With SCORE funding, the overall objective for this application is to validate a survey instrument that can be used in future studies to measure HMB and, in the process, to generate data on the prevalence of HMB across populations.

Jinhu Wang, MD

Assistant Professor

Department of Medicine (Cardiology)
Emory School of Medicine

2022 Pilot Grant Recipient

CHARACTERIZING SEX DIFFERENCES IN MALE AND FEMALE ZEBRAFISH HEART REGENERATION
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WHY SEX MATTERS IN SCIENCE:

... Because although sexual dimorphism seems to exist in heart diseases and repair, a mechanistic understanding of this sex difference is still lacking. Deciphering the mechanisms of sex differences will provide an important gateway toward better prevention and treatment of cardiovascular disease in women.

ABSTRACT

Humans, like all mammals, possess a limited myocardial regeneration capacity. This deficiency contributes to heart failure, the leading cause of morbidity and mortality in the United States. Recent discoveries indicate that mammalian heart has an endogenous regeneration program but cannot efficiently initiate or complete the entire process. Fully deciphering cardiac regeneration mechanisms will promote therapeutic strategies to prevent or treat human heart failure. Zebrafish robustly regenerate lost myofibers by proliferating spared cardiomyocytes (CMs). This process is facilitated by other cell types, like epicardial and immune cells, representing an excellent model to explore heart regeneration.

In preliminary studies, we employed bulk RNA-seq and in situ hybridization analyses to examine gene expression in male and female regenerating hearts, and found the expression levels of 258 genes have sex differences in regenerating hearts, including the f13a gene. With a newly generated f13a:EGFP BAC transgenic reporter, we visualized few f13a:EGFP+ cells in uninjured female hearts but they rapidly accumulate in the injury area. In contrast, no f13a:EGFP+ cells appear in male hearts with or without injury. Further examination of f13aexpressing cells with immunohistology and our unpublished single-cell RNA sequencing dataset suggested that f13a+ cells are immune cells. As immune cells play critical roles in heart repair and regeneration, characterizing sex-specific immune cells will be essential for understanding regeneration differences in male and female hearts.

Based on our preliminary results, our hypothesis for this proposal is that f13a+ cells and the f13a gene are critical components for the enhanced heart regeneration capacity observed in females. To test this hypothesis, we will: 1) perform single-cell RNA sequencing to obtain a molecular profile of f13a+ cells; 2) establish genetic methods to specifically deplete f13a+ cells and examine the effect of their loss on female heart regeneration; and 3) examine the effect of f13a knockout on female heart regeneration.

As female-specific cell types/genes haven't been identified in the zebrafish heart before, our work will generate paradigm-shifting sex difference discoveries in cardiac regeneration biology, and reveal the impact of sex-specific cells and genes on heart regeneration. These findings will reveal new approaches for sex difference research in zebrafish, and potentially enhance research on human hearts after myocardial infarction.

James Q. Zheng, PhD

Professor

Department of Cell Biology
Emory School of Medicine

2022 Pilot Grant Recipient

ELEVATED VULNERABILITY IN FEMALE AND AGING POPULATIONS TO LONG-TERM DEFICITS AND DEGENERATION AFTER MILD HEAD TRAUMA
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WHY SEX MATTERS IN SCIENCE:

...Females tend to demonstrate a course of outcome and recovery from mild traumatic brain injury that is different than the ones males experience but we do not yet understand how or why this is so. If we can unravel how the mechanistic underpinnings of early exposure to mild head trauma lead to later brain degeneration and disability, we may be able to develop therapeutic strategies for treatment and recovery that are optimized for women.

ABSTRACT

Increasing evidence supports the existence of sex-related differences in many medical conditions, including several neurodegenerative disorders, but the underlying mechanisms remain to be fully understood.

Traumatic brain injury (TBI) is extremely common and represents a great risk for long-term brain disability and can accelerate the progressive neurodegeneration. In particular, repetitive exposure to mild TBI is believed to set in motion often latent pathologic processes that can later emerge in association with a number of disorders that include Chronic Traumatic Encephalopathy (CTE), Alzheimer's disease (AD), Parkinson's disease like disorders, and other associated progressive neurodegenerative conditions. At presence, we unfortunately lack the mechanistic understanding of how early exposure to mild head trauma leads to later emergence of brain degeneration and disability.

Importantly, sex is known to be an important biological variable that influences the outcome of TBI of various severities. However, it remains to be determined if and how different sexes of individuals respond to mTBI with different outcomes and, importantly, whether the later development of brain deficits is more prevalent in one sex over the other. Finally, emerging evidence indicates that age represents a major risk factor that can significantly impact and contribute to the long-term brain deficits after head injury. It is of great importance to understand how If and how aging affects sex differences in response to mild head injury, subsequent recovery, and the development of long-term deficits later in life.

We recently developed a novel head injury model in Drosophila melanogaster to investigate the long-term effects of mild head trauma on brain structure and function, as well as the underlying mechanisms. Fruit flies represent an excellent tractable model organism to dissect fundamental cellular and molecular disease mechanisms, including neurodegeneration. Importantly, the relatively short lifespan of fruit flies enables longterm outcome analyses related to head injury exposure.

We have already shown that adult fruit flies subjected to repetitive mild head trauma developed long-term sensorimotor deficits and brain degeneration, all of which were substantially exacerbated in female flies (Behnke et al, Sci Reports 11:9738, 2021). In this study, we will utilize our novel Drosophila head injury model to fully investigate the sex differences in developing brain deficits and degeneration after mild head trauma.

Importantly, we will investigate how aging impacts the brain deficits in a sex-dependent manner in response to mild head trauma. Finally, we will perform an unbiased transcriptome analysis to identify the transcriptional changes associated with the later emergence of brain dysfunction and deficits. Our goal is to use the model organism and the novel head trauma model to gain mechanistic insights into the development of brain disorders triggered by head trauma.

Wei Zhou, PhD | Rabin Tirouvanziam, PhD

Professor

Department of Hematology and Medical Oncology
Emory School of Medicine

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Assistant Professor

Department of Pediatric Infectious Diseases
Emory School of Medicine

2022 MPI Pilot Grant Recipients

SEX BIAS IN STING SIGNALING AND DOWNSTREAM FUNCTIONS OF LUNG-INFLITRATING NEUTROPHILS AS A KEY CONTRIBUTOR TO DISEASE SEVERITY AND DRUG RESPONSE
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WHY SEX MATTERS IN SCIENCE:

... Because there are strong sex-biased outcomes in lung cancer but, because we don't understand why, we don't know how to overcome them.

ABSTRACT

The LKB1/STK11 tumor suppressor is one of the most frequently mutated genes in smoking-related lung adenocarcinoma (LUAD). A multidimensional analysis of LUAD patients indicates that STK11/LKB1 is the top sexbiased gene, being more frequently mutated in males than in females. This is a surprising discovery because LKB1 is mostly mutated in smoking-relative lung cancer, and previous sex-specific studies indicated that females are more prone to smoking-related DNA adduct formation in the lungs.

Several established mouse models also suggested the female sex is associated with a higher incidence of lung cancer formation. Thus, there is an urgent need for the development of new treatments using clinically relevant mammalian models. The Zhou laboratory and other groups established genetically engineered mouse models (KL-GEMM), which can form KrasG12D/LKB1null LUAD in the lung with similar features to human LUAD in tumor characteristics, microenvironment, and resistance to immune checkpoint blockade therapy.

A meta-analysis of the model revealed LUAD formation in 97% of males vs. 58% of females. In addition, the establishment of lung metastases in this syngeneic model also showed a strong sex bias in females. A decrease in tumor growth is also observed in female nude mice, but not in NSG mice. Since nude mice lack T- and B-cell immunity but retain innate immune function while NSG mice lack all, these data suggest innate immune cells play a role in this process.

Independently, the Tirouvanziam laboratory has investigated the ability of neutrophils, the most abundant subset of innate immune cells, to adopt novel functional fates upon recruitment to the human lung. Chronic recruitment of neutrophils is a key event in lung cancer, notably in LKB1/STK11-driven LUAD. Our work unveiled profound transcriptional and functional reprogramming in lung-recruited neutrophils involving the methyltransferase Enhancer of zeste homolog 2 (EZH2). EZH2 is a direct target of LKB1 and a regulator of stress responses mediated by STING, the major sensor of cytosolic DNA that regulates pathogen and cancer recognition. Interestingly, recent studies have shown strong sex bias in neutrophil-mediated STING signaling.

Based on the above data, we hypothesize that sex-biased STING signaling and downstream functions in recruited neutrophils may be responsible, at least in part, for the sex-biased outcomes in lung cancer. To test this hypothesis, we will pursue two pilot aims: 1 – Quantify differences in STING signaling and downstream functions in neutrophildominated lung cancer based on sex; 2 – Evaluate the response to EZH2- and STING-targeted drugs in neutrophildominated lung cancer based on sex. Successful completion of this pilot study will pave the way for a comprehensive, joint R01 proposal focused on sex differences in neutrophil modulation of primary and metastatic lung cancer, to be submitted to NCI in 2023.