Zheng, HaiAn Theses Advised
Permanent URI for this collection
Browse
Recent Submissions
Item Endocannabinoids May Enhance the Blood-Brain Barrier Function during Ischemic Stroke(Albany College of Pharmacy and Health Sciences Theses, 2021-12) Hagan, Kofi Amissah '21Stroke, a medical emergency, is a leading cause of death or long-term disability in the US and globally. There is a need for safe and effective therapy to mitigate the neurological consequences and protect the blood-brain barrier (BBB) after ischemia and during reperfusion. This study investigated the endocannabinoids' possible protective roles in barrier function using human brain microvascular cell (HBMEC) as an in vitro BBB model. LCMS was used to determine the baseline level of endocannabinoid (eCB), Anandamide (AEA), from the human brain microvascular cell (HBMEC). Western blot and PCR studies confirmed the expression of CB1 and CB2 in normal conditions and their alteration before and after ischemia. Trans endothelial electrical resistance (TEER) studies conducted to study the barrier characteristic of the HBMEC through the ischemia event showed that AEA enhanced barrier function, at concentrations from 10nM to 100uM. Our study demonstrated the therapeutic potential of the ECS during ischemic stroke by protecting the blood-brain barrier integrity.Item Alterations of the Endocannabinoid System in Post-Ischemic Endothelial Cells of the Blood Brain Barrier(Albany College of Pharmacy and Health Sciences Theses, 8/15/2019) Thurston, Andrew B. '19The continued prominence of ischemia-based conditions (stroke, TBI, and CTE) in the US population and lack of an efficacious medicinal therapy, has led to the exploration of the emerging field of medicinal cannabis for a potential remedy. The purpose of this study is to confirm the existence of the endocannabinoid system (ECS) in endothelial cells of the Blood Brain Barrier and explore the effects of ischemia on the cannabinoid receptor expression and the capacity of the endocannabinoids as protective agents. Using RT-qPCR and Western blot the cannabinoid receptor expression (C\302\254B\302\2541/CB2) under normal conditions and 0, 2, 8, and 24 hrs after a 4-hour oxygen-glucose deprivation (OGD) incubation were quantified. Endocannabinoids (eCBs), AEA and 2-AG, in mixture or solo were administered under normal conditions and 0, 2, 8, and 24 hrs after OGD to evaluate their effects on membrane integrity, cell activity, an ion regulation via TEER analysis, MTT assay, and an intracellular calcium stain. RT-qPCR and Western blot confirmed the presence of the cannabinoid receptors at the genetic and protein level and that their expression relationship under normal conditions mimicked that of other cells related to the CNS. The CB1 receptor displayed a downward trend following OGD incubation while the CB2 receptor displayed an upward trend with a noted dip at 2 hours following OGD. A mixture of the endocannabinoids, under normal conditions, resulted in a dose-dependent increase in monolayer membrane integrity with reduced permeability. Following OGD incubation 2-AG was found to be a more potent agent than AEA in supporting barrier integrity. Additionally, 2-AG also attenuated decreased cell activity at 0 and 2 hrs after OGD and 2 hrs after OGD for 10 and 25 ng/mL doses, respectively. Lastly, AEA at 10, 25, and 50 ng/mL doses increased intracellular calcium, while 2-AG generally had no impact on calcium levels compare to control. This study confirmed the presence of the ECS on endothelial cells of the BBB along with the alteration of the cannabinoid receptor expression as a result of ischemic-mimicking conditions (OGD). Our data indicates that 2-AG acts as a protective agent, while AEA displayed disruptive properties, indicating an important role of the eCBs and ECS in barrier integration and validity, especially following ischemic stress.Item Stability and biodistribution of endocannabinoids across the human brain microvascular endothelium barrier(Albany College of Pharmacy and Health Sciences Theses, 2019-05) Pruyn, Schuyler '19The discovery of the endocannabinoid system (ECS) has brought more interests for further research, which are essential to understand its mechanism of this system and the therapeutic potential of the cannabinoids and medical cannabis. The ECS is active throughout the central and peripheral nervous systems and is comprised of the cannabinoid receptors (CBRs), the endogenous ligands (endocannabinoids, eCBs), and their synthetic and metabolic enzymes. The endocannabinoids, such as anandamide (AEA) and 2-arachidonoylglyrol (2AG) are produced for many neurological responses, such as reducing sensitivity to pain. There is a need to develop simple, yet effective methods to identify and quantify these natural chemicals from various mediums and bio-matrices. Such real-time quantification will allow us to determine their chemical and biological distribution and metabolism when they circulate throughout the body. This study focuses on the stability of AEA and 2AG at blood-brain barrier (BBB) and their permeability across it. With properly developed methods, the chemical stability and kinetics, as well as the biodistribution across the BBB of these lipids are determined and quantified to better understand their clinical impacts.