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Effects of Choline Acetyltransferase in a Murine Model of Hypertension.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Effects of Choline Acetyltransferase in a Murine Model of Hypertension./
作者:	Stiegler, Andrew.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
面頁冊數:	135 p.
附註:	Source: Dissertations Abstracts International, Volume: 82-11, Section: B.
Contained By:	Dissertations Abstracts International82-11B.
標題:	Medicine. -
電子資源:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28493222
ISBN:	9798728243212

Effects of Choline Acetyltransferase in a Murine Model of Hypertension.
Stiegler, Andrew.

Effects of Choline Acetyltransferase in a Murine Model of Hypertension. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 135 p.

Source: Dissertations Abstracts International, Volume: 82-11, Section: B.

Thesis (Ph.D.)--Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 2021.

This item must not be sold to any third party vendors.

Hypertension is a global threat to public health that affects over one billion adults worldwide. Hypertension is a major risk factor for cardiovascular disease, including myocardial infarction and stroke. Although there are many classes of medications which are prescribed for hypertension, most patients do not control their hypertension. This suggests the need for novel therapeutic targets. A novel mechanism of blood pressure regulation by CD4+ T cells that express choline acetyltransferase (ChAT) has recently been described (TChAT cells). These TChAT cells produce acetylcholine, which binds to muscarinic acetylcholine receptors on endothelial cells. This binding causing signaling that leads to an increase in intracellular calcium, which in turn phosphorylates endothelial nitric oxide synthase (eNOS), the enzyme responsible for the synthesis of nitric oxide (NO). NO produced by endothelial cells diffuses into smooth muscle cells surrounding the endothelium causing vasorelaxation through multiple mechanisms, including cGMP-dependent and independent pathways. However, the source of endothelial acetylcholine remains poorly understood. In addition to TChAT cells in circulation, ChAT can synthesize ACh in the circulation, and the substrates for ACh production, choline and acetyl-coenzyme A, exist in the circulation. We sought to investigate the therapeutic potential of ChAT in a model of hypertension.In Aim 1, we develop a system for measuring and analyzing murine physiological data over both short- and long-term time scales. We utilize telemetry to obtain accurate blood pressure, heart rate, temperature, and activity levels from awake, freely-behaving mice. We develop a data analysis pipeline to analyze telemetry data for long-term trends and report novel physiological changes in a commonly used murine model of hypertension. We report decreased heart rate and body temperature in the angiotensin II-infusion.In Aim 2, we investigate the effects of the protein ChAT in hypertension. First, we adapt a colorimetric assay to show that recombinant ChAT catalyzes the enzymatic reaction to produce acetylcholine. We show that a single administration of ChAT at daily minimum blood pressure, when room lights are on, transiently decreases blood pressure without affecting activity levels. In order to increase the duration of transient blood pressure decrease, we performed a non-specific PEGylation of the protein (PEG-ChAT). We show that PEG-ChAT retains similar enzymatic activity to ChAT. We also show that in our model of hypertension, PEG-ChAT-induced BP decrease persists longer than ChAT-induced BP decrease. We repeat these experiments at daily maximum blood pressure, which occurs when room lights are off. When injected with room lights off, PEG-ChAT produces decreases in blood pressure that persist for approximately 24 hours post-injection. We observed a dose-response effect.In conclusion, we show a system for measuring murine blood pressures and analyzing blood pressure data. From that system, we have shown that the angiotensin II model of hypertension induces not only hypertension, but decreased heart rate and temperatures that are not consistent with the hypertension seen in human patients. Consideration of these differences will be important in the study of future therapeutics. These changes will be important to consider in future studies of antihypertensive therapeutics. Additionally, we show for the first time that administration of ChAT can decrease blood pressure. We show that PEGylated ChAT can induce more robust decreases in blood pressure, indicating the potential for protein modifications to increase therapeutic potential. PEGylated ChAT can be further optimized by techniques such as site-specific PEGylation, and multiple PEGylated protein drugs are currently approved by FDA. We also show that the time of treatment can change the effectiveness of ChAT administration. Additionally, acetylcholine is anti-inflammatory. Targeting inflammation has been successful in other cardiovascular diseases, and it is reasonable that an anti-inflammatory therapy for hypertension could have improved efficacy compared to currently available medications.

ISBN: 9798728243212Subjects--Topical Terms:

641104
Medicine.
Subjects--Index Terms:

Acetylcholine

Effects of Choline Acetyltransferase in a Murine Model of Hypertension.
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300 $a 135 p.
500 $a Source: Dissertations Abstracts International, Volume: 82-11, Section: B.
500 $a Advisor: Tracey, Kevin J.;Chavan, Sangeeta S.
502 $a Thesis (Ph.D.)--Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a Hypertension is a global threat to public health that affects over one billion adults worldwide. Hypertension is a major risk factor for cardiovascular disease, including myocardial infarction and stroke. Although there are many classes of medications which are prescribed for hypertension, most patients do not control their hypertension. This suggests the need for novel therapeutic targets. A novel mechanism of blood pressure regulation by CD4+ T cells that express choline acetyltransferase (ChAT) has recently been described (TChAT cells). These TChAT cells produce acetylcholine, which binds to muscarinic acetylcholine receptors on endothelial cells. This binding causing signaling that leads to an increase in intracellular calcium, which in turn phosphorylates endothelial nitric oxide synthase (eNOS), the enzyme responsible for the synthesis of nitric oxide (NO). NO produced by endothelial cells diffuses into smooth muscle cells surrounding the endothelium causing vasorelaxation through multiple mechanisms, including cGMP-dependent and independent pathways. However, the source of endothelial acetylcholine remains poorly understood. In addition to TChAT cells in circulation, ChAT can synthesize ACh in the circulation, and the substrates for ACh production, choline and acetyl-coenzyme A, exist in the circulation. We sought to investigate the therapeutic potential of ChAT in a model of hypertension.In Aim 1, we develop a system for measuring and analyzing murine physiological data over both short- and long-term time scales. We utilize telemetry to obtain accurate blood pressure, heart rate, temperature, and activity levels from awake, freely-behaving mice. We develop a data analysis pipeline to analyze telemetry data for long-term trends and report novel physiological changes in a commonly used murine model of hypertension. We report decreased heart rate and body temperature in the angiotensin II-infusion.In Aim 2, we investigate the effects of the protein ChAT in hypertension. First, we adapt a colorimetric assay to show that recombinant ChAT catalyzes the enzymatic reaction to produce acetylcholine. We show that a single administration of ChAT at daily minimum blood pressure, when room lights are on, transiently decreases blood pressure without affecting activity levels. In order to increase the duration of transient blood pressure decrease, we performed a non-specific PEGylation of the protein (PEG-ChAT). We show that PEG-ChAT retains similar enzymatic activity to ChAT. We also show that in our model of hypertension, PEG-ChAT-induced BP decrease persists longer than ChAT-induced BP decrease. We repeat these experiments at daily maximum blood pressure, which occurs when room lights are off. When injected with room lights off, PEG-ChAT produces decreases in blood pressure that persist for approximately 24 hours post-injection. We observed a dose-response effect.In conclusion, we show a system for measuring murine blood pressures and analyzing blood pressure data. From that system, we have shown that the angiotensin II model of hypertension induces not only hypertension, but decreased heart rate and temperatures that are not consistent with the hypertension seen in human patients. Consideration of these differences will be important in the study of future therapeutics. These changes will be important to consider in future studies of antihypertensive therapeutics. Additionally, we show for the first time that administration of ChAT can decrease blood pressure. We show that PEGylated ChAT can induce more robust decreases in blood pressure, indicating the potential for protein modifications to increase therapeutic potential. PEGylated ChAT can be further optimized by techniques such as site-specific PEGylation, and multiple PEGylated protein drugs are currently approved by FDA. We also show that the time of treatment can change the effectiveness of ChAT administration. Additionally, acetylcholine is anti-inflammatory. Targeting inflammation has been successful in other cardiovascular diseases, and it is reasonable that an anti-inflammatory therapy for hypertension could have improved efficacy compared to currently available medications.
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650 4 $a Biomedical engineering. $3 535387
653 $a Acetylcholine
653 $a Blood pressure
653 $a Choline acetyltransferase
653 $a Data analysis
653 $a Hypertension
653 $a Inflammation
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710 2 $a Donald and Barbara Zucker School of Medicine at Hofstra/Northwell. $b School of Medicine. $3 3544191
773 0 $t Dissertations Abstracts International $g 82-11B.
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791 $a Ph.D.
792 $a 2021
793 $a English
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