PNA5, A Novel Mas Receptor Agonist, Improves Neurovascular and Blood-Brain-Barrier Function in a Mouse Model of Vascular Cognitive Impairment and Dementia

It is well established that decreased brain blood flow, increased reactive oxygen species production (ROS), and pro-inflammatory mechanisms accelerate neurodegenerative disease progressions, including vascular cognitive impairment and dementia (VCID). Previous studies in our laboratory have shown that our novel glycosylated Angiotensin-(1-7) Mas receptor agonist PNA5 reverses cognitive deficits, decreases ROS production, and inhibits inflammatory cytokine production in our preclinical mouse model of VCID that is induced by chronic heart failure (VCID-HF). In the present study, the effects of VCID-HF and treatment with PNA5 on microglia activation, blood-brain-barrier (BBB) integrity, and neurovascular coupling were assessed in our mouse model of VCID-HF. Three-month-old male C57BL/6J mice were subjected to myocardial infarction (MI) to induce heart failure for four weeks and then treated with subcutaneous injections of extended-release PNA5. Microglia activation, BBB permeability, cerebral perfusion, and neurovascular coupling were assessed. Results show that in our VCID-HF model, there was an increase in microglial activation and recruitment within the CA1 and CA3 regions of the hippocampus, a disruption in BBB integrity, and a decrease in neurovascular coupling. Treatment with PNA5 reversed these neuropathological effects of VCID-HF, suggesting that PNA5 may be an effective disease-modifying therapy to treat and prevent VCID. This study identifies potential mechanisms by which heart failure may induce VCID and highlights the possible mechanisms by which treatment with our novel glycosylated Angiotensin-(1-7) Mas receptor agonist, PNA5, may protect cognitive function in our model of VCID.

Abstract P3-05-44: Genomic testing and Ki-67 Percentage: Two puzzle pieces being undervalued in breast cancer treatment

Background: Genetic resources are underutilized when it comes to being incorporated into a breast cancer patient’s treatment, but that isn’t the only piece being overlooked. The Ki-67 proliferation index expressed (Ki-67%) is an established marker of tumor proliferation and aggressive behavior. We hypothesized that Ki-67% could have increased clinical utility when correlated with genomic testing results. Methods: Data was obtained from the Informed Genetics Annotated Patient Registry (iGAP), an IRB-approved, multi-center longitudinal registry designed to capture biomarker test results and their impact on treatment practices and outcomes. Tumor grades and Ki-67% were taken from patient pathology reports. The average Ki-67% was then calculated and compared for each tumor grade, MammaPrint genomic recurrence risk category (ultra low risk, low risk, and high risk), and Blueprint molecular subtype (Luminal type A, Luminal type B, Basal, and HER 2 type). ANOVA statistical analysis was performed for significance values. Results: Of 3102 patients enrolled in the iGAP Registry, 733 were diagnosed with breast cancer and had available tumor grade and Ki-67% data. Among these patients, 357 had genomic recurrence risk (MammaPrint) and 220 genomic molecular subtyping (BluePrint) reports. As expected, tumor grades were significantly positively correlated with Ki-67% (p< 0.0001 between all 3 tumor grade groups). Average Ki-67% in each genomic recurrence risk revealed a significant difference between Low Risk (14%, range 1-70%) and High Risk (36%, range 1-95%, p< 0.0001). Among the genomic molecular subtypes, there were significant differences in Ki-67% between Basal (avg 69%, 17-95%) and Luminal type A (avg 13%, 1-70%, p< 0.0001)) and all other subtypes, while Luminal type B (avg 24%, 1-80%) and HER 2 (avg 38%, 29-45%) were not significantly different from each other (p=0.2817), but still significantly different to all other subtypes. Conclusion: From these results, we can deduce that molecular subtype correlates with, but is clinically distinct from, Ki-67 proliferation index. These results also indicate that molecular subtype correlates with higher tumor grades, possibly due to increased cell proliferation. Achieving truly personalized clinical decision making requires utilizing multiple modalities and biomarkers, integrating the results into management.

Citation Format: Chloe Wernecke, Krista Ortega, Kelly Bontempo, Brenna Bentley, Christina Hoyer-Kimura, Peter Beitsch, Rakesh Patel, Barry Rosen, Gia Compagnoni, Ian Grady, Eric Brown, Lindsay Gold, Pat Whitworth, Linda Ann Smith, Richard Reitherman, Mariusz Wirga, Steven Cai, Toan Nguyen, Valerie Traina, Dennis Holmes, Paul Baron, Brittany Krautheim, Anne Peled, Walt Taylor. Genomic testing and Ki-67 Percentage: Two puzzle pieces being undervalued in breast cancer treatment [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-05-44.

A homemade device for simultaneous measurement of pulmonary ventilation and metabolic rate in neonatal rodents

Various in vitro neonatal rodent models have been developed to study the control of breathing, but translation of the information requires a behavioral assay, which has led to the widespread use of plethysmography to measure breathing in awake neonatal rodents. Best practice requires correcting changes in ventilation to the corresponding change in metabolic rate, which is the main driver of pulmonary ventilation. Obtaining measures of both simultaneously is ideal, though technically difficult. Here we describe a simple, inexpensive home-made dual chamber approach for simultaneous measurement of pulmonary ventilation and metabolic rate. We found that the dual chamber provides values for pulmonary ventilation and metabolic rate that compare favorably with existing approaches.

Neurofilament light: a possible prognostic biomarker for treatment of vascular contributions to cognitive impairment and dementia

Background

Decreased cerebral blood flow and systemic inflammation during heart failure (HF) increase the risk for vascular contributions to cognitive impairment and dementia (VCID) and Alzheimer disease-related dementias (ADRD). We previously demonstrated that PNA5, a novel glycosylated angiotensin 1–7 (Ang-(1–7)) Mas receptor (MasR) agonist peptide, is an effective therapy to rescue cognitive impairment in our preclinical model of VCID. Neurofilament light (NfL) protein concentration is correlated with cognitive impairment and elevated in neurodegenerative diseases, hypoxic brain injury, and cardiac disease. The goal of the present study was to determine (1) if treatment with Ang-(1–7)/MasR agonists can rescue cognitive impairment and decrease VCID-induced increases in NfL levels as compared to HF-saline treated mice and, (2) if NfL levels correlate with measures of cognitive function and brain cytokines in our VCID model.

Methods

VCID was induced in C57BL/6 male mice via myocardial infarction (MI). At 5 weeks post-MI, mice were treated with daily subcutaneous injections for 24 days, 5 weeks after MI, with PNA5 or angiotensin 1–7 (500 microg/kg/day or 50 microg/kg/day) or saline (n = 15/group). Following the 24-day treatment protocol, cognitive function was assessed using the Novel Object Recognition (NOR) test. Cardiac function was measured by echocardiography and plasma concentrations of NfL were quantified using a Quanterix Simoa assay. Brain and circulating cytokine levels were determined with a MILLIPLEX MAP Mouse High Sensitivity Multiplex Immunoassay. Treatment groups were compared via ANOVA, significance was set at p < 0.05.

Results

Treatment with Ang-(1–7)/MasR agonists reversed VCID-induced cognitive impairment and significantly decreased NfL levels in our mouse model of VCID as compared to HF-saline treated mice. Further, NfL levels were significantly negatively correlated with cognitive scores and the concentrations of multiple pleiotropic cytokines in the brain.

Conclusions

These data show that treatment with Ang-(1–7)/MasR agonists rescues cognitive impairment and decreases plasma NfL relative to HF-saline-treated animals in our VCID mouse model. Further, levels of NfL are significantly negatively correlated with cognitive function and with several brain cytokine concentrations. Based on these preclinical findings, we propose that circulating NfL might be a candidate for a prognostic biomarker for VCID and may also serve as a pharmacodynamic/response biomarker for therapeutic target engagement.

Serum Neurofilament Light is elevated in COVID-19 Positive Adults in the ICU and is associated with Co-Morbid Cardiovascular Disease, Neurological Complications, and Acuity of Illness

In critically ill COVID-19 patients, the risk of long-term neurological consequences is just beginning to be appreciated. While recent studies have identified that there is an increase in structural injury to the nervous system in critically ill COVID-19 patients, there is little known about the relationship of COVID-19 neurological damage to the systemic inflammatory diseases also observed in COVID-19 patients. The purpose of this pilot observational study was to examine the relationships between serum neurofilament light protein (NfL, a measure of neuronal injury) and co-morbid cardiovascular disease (CVD) and neurological complications in COVID-19 positive patients admitted to the intensive care unit (ICU). In this observational study of one-hundred patients who were admitted to the ICU in Tucson, Arizona between April and August 2020, 89 were positive for COVID-19 (COVID-pos) and 11 was COVID-negative (COVID-neg). A healthy control group (n=8) was examined for comparison. The primary outcomes and measures were subject demographics, serum NfL, presence and extent of CVD, diabetes, sequential organ failure assessment score (SOFA), presence of neurological complications, and blood chemistry panel data. COVID-pos patients in the ICU had significantly higher mean levels of Nfl (229.6 ± 163 pg/ml) compared to COVID-neg ICU patients (19.3 ± 5.6 pg/ml), Welch's t-test, p =.01 and healthy controls (12.3 ± 3.1 pg/ml), Welch's t-test p =.005. Levels of Nfl in COVID-pos ICU patients were significantly higher in patients with concomitant CVD and diabetes (n=35, log Nfl 1.6±.09), and correlated with higher SOFA scores (r=.5, p =.001). These findings suggest that in severe COVID-19 disease, the central neuronal and axonal damage in these patients may be driven, in part, by the level of systemic cardiovascular disease and peripheral inflammation. Understanding the contributions of systemic inflammatory disease to central neurological degeneration in these COVID-19 survivors will be important to the design of interventional therapies to prevent long-term neurological and cognitive dysfunction.

Abstract P366: The Impact Of Estrogen Signaling On Gut Epithelial Cells

Cardiovascular disease (CVD) is the leading cause of death in women worldwide. Menopause is associated with increased susceptibility to CVD, but the mechanism is currently unknown. Studies have suggested that loss of estrogen signaling in the intestine during menopause may lead to worse myocardial infarction (MI) outcomes in female mice. Our lab has shown that suppressing inflammation in the gut using pre- and pro-biotics protects the heart from ischemic heart disease caused by MI through unknown means. We propose that alterations in gut microbiota are due to destruction of intestinal pattern recognition receptors (PRRs) such as toll-like receptor 4 (TLR4) and TLR5. Studies show that estrogen signaling modulates PRRs in other tissues, but this has yet to be investigated in gut epithelial cells. To elucidate the mechanisms of estrogen receptor function in the gut as a direct mediator of vascular health, we are utilizing an immortalized human cell line of colorectal adenocarcinoma brush border expressing (Caco2 BBE) cells. We hypothesized that estrogen treatment in gut epithelial cells will lead to increased expression of PRRs and decreased inflammation in Caco2 BBE cell lines. To investigate expression and localization of estrogen receptors (ERs), Caco2 BBE cells at different confluency were treated with estradiol (E2) or DMSO control for 24hrs, then either RNA or protein were harvested for use in qPCR and western blot, or cells were formalin fixed for use in immunohistochemistry. In each case, ERα was not detected, but ERβ was present at varying concentrations. Data also showed increased expression of TLR5 and TLR7 in E2 treated cells, while TNF-α and IL-1 were decreased. In conclusion, data show potential confluency dependent ERβ expression and suggest that ERα may not be present in our Caco2 BBE cell line. Our hypothesis is also supported by data for PPRs and inflammatory markers. Though these results are revealing, future studies are needed to further characterize Caco2 BBE cells in the context of ER signaling.