Document text
Principal Investigator: Eric D Lazartigues
Organization: LSU HEALTH SCIENCES CENTER
Fiscal Year: 2022
Award: $600,541
Funding agency: National Heart Lung and Blood Institute
With prevalence as high as 55% for individuals aged 55 and older in United States, hypertension is a major risk
factor contributing to cardiovascular diseases (CVD) and global mortality, hence remaining an increasingly
important medical and public health issue. The role of the renin-angiotensin system (RAS) in the maintenance
of normal blood pressure (BP) and in the neuro-cardiovascular dysregulation leading to hypertension has been
firmly established. Angiotensin (Ang)-II, by means of its type 1 receptor (AT1R), promotes increased sympathetic
activity, salt and water reabsorption, vasoconstriction, aldosterone and vasopressin release and inflammation,
all contributing to hypertension. Angiotensin Converting Enzyme type 2 (ACE2), one of the latest identified
members of this system cleaves Ang-II and produces Ang-(1-7) which plays a compensatory role and opposes
the RAS deleterious effects. Beyond establishing ACE2 as a critical player in the prevention of neurogenic
hypertension, our group was the first to report that Ang-II mediates ACE2 ubiquitination and degradation via
AT1R activation, effects that were prevented by pretreatment with a lysosomal inhibitor. Although confirmed by
independent groups, the therapeutic potential of preventing ACE2 ubiquitination and degradation has not been
investigated. Our pilot data, show that mutation of the C-terminus of ACE2 prevents the ubiquitination and
preserves ACE2 compensatory activity while treatment with an ubiquitination-resistant ACE2 virus blunts the
development of Ang-II-mediated hypertension in mice otherwise lacking ACE2. In addition, we show that
targeting NEDD4, a major family of E3 ubiquitin ligases, neutralizes the deleterious effects of Ang-II on ACE2
activity, while a pilot proteomics analysis highlighted gender-specific modulation of other E3 ligases and de-
ubiquitinases in the hypothalamus of mice undergoing salt-sensitive hypertension. Our preliminary data further
highlight that this mechanism is not restricted to AT1R but that bradykinin B1R, activated by the inflammatory
response associated to hypertension, are also involved. Thus, the hypothesis of this work is that RAS over-
activation and hypertension-associated inflammation exacerbate ACE2 ubiquitination, resulting in enhanced
degradation of this enzyme and a loss of its compensatory activity, ultimately reinforcing hypertension. Here, we
will target ACE2 ubiquitination using novel viral approaches and unique transgenic models with an emphasis on
gender- and cell-specific differences in the central nervous system and the vasculature. Validation of our
hypothesis will open the door for new targeting approaches aimed at preserving ACE2 compensatory activity in
hypertension and CVD.
Terms: <ACE2><APF-1><ATP-Dependent Proteolysis Factor 1><Address><Affect><Age><Aldosterone><Ang I (1-7)><AngII><Angiotensin Converting Enzyme><Angiotensin I-Converting Enzyme><Angiotensin II><Antidiuretic Hormone><Antimorphic mutation><Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg><Blood Pressure><Bradykinin><Brain><Brain Nervous System><CD143 Antigens><CNS Nervous System><Carboxycathepsin><Cardiovascular><Cardiovascular Body System><Cardiovascular Diseases><Cardiovascular Organ System><Cardiovascular system><Cell Body><Cells><Central Nervous System><Cerebrovascular system><DNA Therapy><Data><Development><Dipeptidyl Peptidase A><Dominant Negative><Dominant-Negative Mutant><Dominant-Negative Mutation><E3 Ligase><E3 Ubiquitin Ligase><Encephalon><Endothelial Cells><Enzyme Gene><Enzymes><Family><Family member><Female><G Protein-Complex Receptor><G Protein-Coupled Receptor Genes><G-Protein-Coupled Receptors><GPCR><Gender><Gene Transfer Clinical><Genetic Alteration><Genetic Change><Genetic Intervention><Genetic defect><HMG-20><Heart Vascular><High Mobility Protein 20><Hydrogen Oxide><Hypertension><Hypothalamic structure><Hypothalamus><Impairment><In Vitro><Individual><Inflammation><Inflammatory><Inflammatory Response><KO mice><Kininase A><Kininase II><Kinins><Knock-out Mice><Knockout Mice><L-Lysine><Laboratories><Ligase><Ligase Gene><Lysine><Lysosomes><Maintenance><Mediating><Medical><Mice><Mice Mammals><Modeling><Molecular><Murine><Mus><Mutation><Nerve Cells><Nerve Unit><Neural Cell><Neuraxis><Neurocyte><Neurons><Null Mouse><Peptidyl-Dipeptidase A><Pharmacology><Play><Population><Prevalence><Prevention><Proteomics><Public Health><Pulmonary Hypertension><Receptor Activation><Receptor Protein><Renin-Angiotensin System><Reporting><Resistance><Risk Factors><Role><Site><Sodium Chloride><Synthetases><System><Telemetries><Telemetry><Testing><Therapeutic><Transfection><Transgenic Model><Transgenic Organisms><Ubiquitilation><Ubiquitin><Ubiquitin Protein Ligase><Ubiquitin-Protein Ligase Complexes><Ubiquitin-Protein Ligase E3><Ubiquitination><Ubiquitinoylation><United States><Validation><Vascular Hypertensive Disease><Vascular Hypertensive Disorder><Vasopressins><Viral><Virus><Water><Work><aged><ages><angiotensin I (1-7)><angiotensin converting enzyme 2><angiotensin converting enzyme II><angiotensin-(1-7)><base><beta-Hypophamine><brain blood vessels><brain vasculature><cardiovascular disorder><cerebral blood vessel><cerebral vasculature><cerebrovascular vessels><cerebrovasculature><circulatory system><conditional knock-out><conditional knockout><de-ubiquitinase><de-ubiquitinating enzyme><developmental><gene repair therapy><gene therapy><gene-based therapy><genetic therapy><genome mutation><genomic therapy><high blood pressure><hyperpiesia><hyperpiesis><hypertension treatment><hypertensive disease><hypertensive disorder><hypothalamic><iPS><iPSC><iPSCs><in vitro activity><in vivo><induced pluripotent stem cell><inducible pluripotent stem cell><inhibitor><kallidin 9><kallidin I><male><member><mortality><mouse model><murine model><mutant><neurogenic hypertension><neuronal><new approaches><novel><novel approaches><novel strategies><novel strategy><optogenetics><preservation><prevent><preventing><receptor><resistant><response><salt><salt hypertension><salt induced hypertension><salt sensitive hypertension><social role><tool><transgenic><transgenic trait><ubiquination><ubiquitin conjugation><ubiquitin isopeptidase><ubiquitin-protein ligase><ubiquitin-specific isopeptidase><vascular constriction><vasoconstriction>