People with diabetes have an increased risk of developing cardiovascular disease (CVD). Hyperglycemia is the hallmark of diabetes, but diabetic dyslipidemia with increased circulating lipid levels is also present, which is believed to contribute to the augmented CVD seen in diabetes. The Cluster of Differentiation 36 (Cd36) receptor mediates fatty acid and lipoprotein uptake in macrophages. Lipid-loaded macrophages are a key feature of atherosclerosis, the underlying CVD pathology. Preliminary data suggest that monocytes (macrophage precursors) are lipid-loaded via increased Cd36. However, it is unclear what drives the increased Cd36 expression in diabetes. Reduction in blood glucose, but not lipid levels, in diabetic mice reduced monocyte cell surface Cd36 expression. Based on these preliminary data, I hypothesize that hyperglycemia induces increased Cd36 mRna expression in monocytes in diabetes. To address whether glucose or lipids increase monocyte Cd36 mRna expression, I will isolate monocytes from the bone marrow of non-diabetic mice and stimulate them ex vivo. To address if hyperglycemia alters Cd36 expression, I will stimulate monocytes with 4 glucose conditions: 5.6 mM, 15 mM, 30.6 mM D-glucose, and an osmotic control of 5.6 mM D-glucose and 25 mM L-glucose. The 5.6 mM represents non-diabetic blood glucose conditions. To address if dyslipidemia alters monocyte Cd36 expression, I will use the same 4 glucose conditions in conjunction with 50 µg/mL of VLDL, a triglyceride-rich lipoprotein that is elevated in diabetic dyslipidemia. Following a 24-hour stimulation, I will isolate monocyte RNA and use qPCR to determine the amount of Cd36 mRna. If elevated glucose induces an increase in Cd36 expression, this suggests that hyperglycemia stimulates increased Cd36 expression in monocytes in diabetes. However, if the presence of VLDL is required to observe an increase in Cd36 mRna, this indicates that dyslipidemia is needed for increased monocyte Cd36 mRna expression. Results from this study will help us understand the relationship between lipids and hyperglycemia in the context of diabetes-induced monocyte lipid loading.

Toll-like receptor 4 (TLR4) is an immune protein which binds lipopolysaccharide (LPS) present on the outer membrane of Gram-negative bacteria and activates the innate immune response. In mice, an mRNA splice variant composed of only the extracellular domain of TLR4 was shown to encode a soluble product (sTLR4) capable of inhibiting inflammatory response to LPS. sTLR4 has been recovered from human saliva and demonstrated to dampen the production of pro-inflammatory cytokines by macrophages. Prior work showed that TLR4 was also present in endometrial glands, uterine tube epithelia and endocervical glands. However, there are no published studies exploring the presence or role of sTLR4 in lower genital tract secretions. We tested primary female genital epithelial cells’ supernatants as well as human endocervical cytobrush and vaginal swab samples for the presence of sTLR4 by using a chemiluminescent immunoassay. We found sTLR4 in cervicovaginal secretions, with increased concentration of sTLR4 present in participants with endocervical ectopy and in those sampled during the proliferative phase of the menstrual cycle. Supernatants from endocervical cell lines possessed higher levels of sTLR4 than those derived from ectocervical or vaginal cells. sTLR4 concentration was not correlated with the presence of bacterial vaginosis, age, the concentration of common vaginal Gram-negative bacteria or with genetic variation in the TLR4 locus. By western blotting, we demonstrated that sTLR4 is composed of a ~100 kDa polypeptide, corresponding to the entire TLR4 ectodomain. In a reporter monocytic cell line, we showed dose-dependent inhibition of the LPS/Interferon-regulatory factor (IRF) pathway when LPS was preincubated with endocervical cells’ supernatants. These results point to an unappreciated form of innate immune regulation in the cervicovaginal niche, which could potentially open new avenues for understanding inflammatory disorders such as cervicitis and pelvic inflammatory disease.

Researchers consider autoimmune disorders and immunodeficiencies to be two completely unrelated conditions. However, it has been shown that patients can develop both diseases in spite of opposing etiologies. This has led researchers to examine the commonalities between autoimmunity and immunodeficiency in terms of pathogenesis, clinical manifestations, treatments and, more recently, genetics. With genome sequencing becoming more prevalent and easier to access, researchers have been able to look at disorders of the immune system from the genomic point of view, identifying genetic mutations of key genes. One such gene is cytotoxic T-lymphocyte associated protein 4 (CTLA-4) because of its known immunoregulatory role in terminating immune responses. CTLA-4 directly regulates the development of T-cells by activating T regulatory cells, but it can also affect the development of B-cells in downstream effects. In this literature review of a multitude of sources, we show that heterozygous mutations of CTLA-4 can lead to patients developing both autoimmune and immunodeficiency manifestations such as hypogammaglobulinemia, autoimmune cytopenia, lymphoproliferation, autoimmune enteropathy, etc. Such mutations point toward commonalities in both autoimmunity and immunodeficiency, leading researchers to believe that these two diseases are more alike than different. With this newfound discovery, treatments can be developed to target the CTLA-4 gene in hopes of treating both autoimmunity and immunodeficiency in patients.

Over 38 million Americans have diabetes, with 90% of diabetic Americans having Type 2 Diabetes. Diabetes causes an increased risk of complications, including diabetic kidney disease (DKD), a disease that affects kidney filtration. This occurs in the glomerulus, a specialized capillary network of single-layered endothelial cells on one side and podocytes on the other, and their extracellular matrix (ECM). Injury, reduced function, or changes in the ECM of either of these cells cause abnormal filtration and kidney disease. Preliminary data from our group suggests that ECM remodeling driven by endothelial cells is a key feature in DKD in both our mouse model and in humans. Additional preliminary data from our lab indicates that two metalloproteases involved in ECM remodeling, ADAMTS6 and ADAMTS9, are increased in endothelial cells in diabetes via elevated lipids. My hypothesis is that very-low-density lipoprotein (VLDL), a lipid often increased in diabetes, induces increased endothelial cell ADAMTS6 and ADAMTS9 expression, contributing to remodeling the ECM and altering the filtration capacity of the glomeruli. To investigate this, isolated endothelial cells from non-diabetic mice were stimulated with varying VLDL concentrations, alone or with elevated glucose, to simulate diabetes. Following the stimulation, I isolated the RNA from these cells and measured the mRNA expression of Adamts9 and Adamts6 using real-time PCR. To test if endothelial cells isolated from mice with diabetes would respond differently, similar experiments are being carried out in cells isolated from diabetic mice. Western blots are used to verify the altered protein expression I observe. I am utilizing already acquired kidney sections from mice with diabetes with different lipid levels and determining the glomerular endothelial cell ADAMTS9 and ADAMTS6 expression by immunohistochemistry. Results from these experiments will help us understand the mechanisms through which endothelial cells respond to diabetes and thus contribute to DKD.

Over 500 million adults worldwide have type II diabetes (T2D), which has caused 6.7 million deaths in 2021 alone. Yet, accessible and sustainable treatments remain limited and many address the symptoms of the disease rather than the root causes, one of which is insulin sensitivity. Recent research shows that therapies targeting glucose-regulating mechanisms in the brain that do not directly affect insulin secretion can enhance diabetes remissions in T2D rodent models. Such treatments may revolutionize diabetes treatment and public health. The Scarlett Lab’s previous studies show that exogenous intracerebroventricular administration of hypothalamic fibroblast growth factor 1 (FGF1) resulted in sustained hyperglycemic remission and increased insulin sensitivity in the mediobasal hypothalamus (MBH), suggesting that FGF1 signaling in the brain impacts glucose metabolism. FGF1 is also endogenously expressed in the MBH, but the functional role of endogenous FGF1 is still unknown. Thus, I hypothesize that endogenous FGF1 signaling in the MBH regulates glucose and energy homeostasis. To test this, I utilize adenosine-associated virus as a vector for gene editing therapy to knock out the Fgf1 gene from the MBH in adult male Fgf1-floxed mice. I then monitor food intake, body weight, and blood glucose levels; perform insulin and glucose tolerance tests; and measure insulin and glucagon levels using enzyme-linked immunosorbent assay. Finally, I use immunohistochemical analysis at the end of the experiment to validate Fgf1 knockout. Based on pilot studies, I expect to observe that MBH Fgf1 knockout significantly increases body weight and impairs glucose tolerance and insulin sensitivity. Follow-up work can elaborate on investigating the effect of a high-fat diet on FGF1 signaling and function. This project illuminates the functional role of endogenous FGF1 signaling in regulating glucose and energy homeostasis and contributes to the development of novel therapeutic strategies to treat diabetes and obesity.

Poor communication within and between teams of health professionals has been shown to lead to errors and negative patient experiences. Daily interprofessional bedside rounds (IBR) in which care team professionals develop and update plans in collaboration with patients and families, are associated with a reduction in these negative outcomes. However, little is known about how IBR and related care outcomes may be influenced by gender differences in patients. In this study, I ask, “Are there gender differences in patient satisfaction with their heart failure team’s rounding model and care plans?” I screened data from questionnaires completed by patients hospitalized with a diagnosis of advanced heart failure at the time of study enrollment, at 10 days post-discharge, and at 30 days post-discharge as part of an ongoing parent study. I stratified data by an individual’s gender indicated in their medical records and cross-referenced that information with self-reported data from enrollment questionnaires. Participant recruitment is ongoing, of the more than 80 current participants, 66% identified as male (n = 56) and 34% identified as female (n = 29). Preliminary results, based on analysis of 23 quantitative questions on perceptions of rounds, indicate that there are gender differences in satisfaction, as nineteen of the questions had a difference in response by gender of .1 or more (including four that had a difference of .4 or more). For example, male participants rated accuracy of communication with their care team at a 4.3 out of 5.0 whereas female participants rated this at 3.8 out of 5.0. Additional research is needed to understand whether these differences are a result of differential treatment of male or female patients by care teams or other factors (e.g. differences in expectations or communication styles) as well as how to improve experiences and outcomes across genders.