Ten-Year Review of Antihypertensive Prescribing Practices After Stroke and the Associated Disparities From the Florida Stroke Registry.

BACKGROUND: Guideline-based hypertension management is integral to the prevention of stroke. We examine trends in antihypertensive medications prescribed after stroke and assess how well a prescriber's blood pressure (BP) medication choice adheres to clinical practice guidelines (BP-guideline adherence). METHODS AND RESULTS: The FSR (Florida Stroke Registry) uses statewide data prospectively collected for all acute stroke admissions. Based on established guidelines, we defined optimal BP-guideline adherence using the following hierarchy of rules: (1) use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker as first-line antihypertensive among diabetics; (2) use of thiazide-type diuretics or calcium channel blockers among Black patients; (3) use of beta blockers among patients with compelling cardiac indication; (4) use of thiazide, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, or calcium channel blocker class as first line in all others; (5) beta blockers should be avoided as first line unless there is a compelling cardiac indication. A total of 372 254 cases from January 2010 to March 2020 are in the FSR with a diagnosis of acute ischemic stroke, hemorrhagic stroke, transient ischemic attack, or subarachnoid hemorrhage; 265 409 with complete data were included in the final analysis. Mean age was 70±14 years; 50% were women; and index stroke subtypes were 74% acute ischemic stroke, 11% intracerebral hemorrhage, 11% transient ischemic attack, and 4% subarachnoid hemorrhage. BP-guideline adherence to each specific rule ranged from 48% to 74%, which is below quality standards of 80%, and was lower among Black patients (odds ratio, 0.7 [95% CI, 0.7-0.83]; P<0.001) and those with atrial fibrillation (odds ratio, 0.53 [95% CI, 0.50-0.56]; P<0.001) and diabetes (odds ratio, 0.65 [95% CI, 0.61-0.68]; P<0.001). CONCLUSIONS: This large data set demonstrates consistently low rates of BP-guideline adherence over 10 years. There is an opportunity for monitoring hypertensive management after stroke.

A 10-year review of antihypertensive prescribing practices after stroke and the associated disparities from the Florida Stroke Registry.

Background: Guideline based hypertension management is integral to the prevention of stroke. We examine trends in antihypertensive medications prescribed after stroke and assess how well a prescribers' blood pressure medication choice adheres to clinical practice guidelines (Prescribers'-Choice Adherence). Methods: The Florida Stroke registry (FSR) utilizes statewide data prospectively collected for all acute stroke admissions. Based on established guidelines we defined optimal Prescribers'-Choice Adherence using the following hierarchy of rules: 1) use of an angiotensin inhibitor (ACEI) or angiotensin receptor blocker (ARB) as first-line antihypertensive among diabetics; 2) use of thiazide-type diuretics or calcium channel blockers (CCB) among African-American patients; 3) use of beta-adrenergic blockers (BB) among patients with compelling cardiac indication (CCI) 4) use of thiazide, ACEI/ARB or CCB class as first-line in all others; 5) BB should be avoided as first line unless CCI. RESULTS: A total of 372,254 cases from January 2010 to March 2020 are in FSR with a diagnosis of acute ischemic, hemorrhagic stroke, transient ischemic attack or subarachnoid hemorrhage; 265,409 with complete data were included in the final analysis. Mean age 70 +/-14 years, 50% female, index stroke subtype of 74% acute ischemic stroke and 11% intracerebral hemorrhage. Prescribers'-Choice Adherence to each specific rule ranged from 48-74% which is below quality standards of 85%. There were race-ethnic disparities with only 49% Prescribers choice Adherence for African Americans patients. Conclusion: This large dataset demonstrates consistently low rates of Prescribers'-Choice Adherence over 10 years. There is an opportunity for quality improvement in hypertensive management after stroke.

The Mitochondrial Deubiquitinase USP30 Regulates AKT/mTOR Signaling.

Mitophagy is an intracellular mechanism to maintain mitochondrial health by removing dysfunctional mitochondria. The E3 ligase Parkin ubiquitinates the membrane proteins on targeted mitochondria to initiate mitophagy, whereas USP30 antagonizes Parkin-dependent mitophagy by removing ubiquitin from Parkin substrates. The AKT/mTOR signaling is a master regulator of cell proliferation, differentiation, apoptosis, and autophagy. Although mounting evidence suggests that perturbations in the AKT/mTOR signaling pathway may contribute to mitophagy regulation, the specific mechanisms between Parkin/USP30 and AKT/mTOR signaling have not been elucidated. In this study, we employ a set of genetic reagents to investigate the role of Parkin and USP30 in regulating the AKT/mTOR signaling during mitophagy. We demonstrated that, in the setting of mitochondrial stress, the AKT/mTOR signaling is regulated, at least in part, by the activity of Parkin and USP30. Parkin inhibits AKT/mTOR signaling following an in vitro mitochondrial stress, thereby promoting apoptosis. However, USP30 overexpression antagonizes the activity of Parkin to sustain AKT/mTOR activity and inhibit apoptosis. These findings provide new insights into Parkin and USP30's role in apoptosis and suggest that inhibiting USP30 might provide a specific strategy to synergize with AKT/mTOR inhibitors in cancer treatment.

Assessment of mitophagy in human iPSC-derived cardiomyocytes.

Defective mitophagy contributes to normal aging and various neurodegenerative and cardiovascular diseases. The newly developed methodologies to visualize and quantify mitophagy allow for additional progress in defining the pathophysiological significance of mitophagy in various model organisms. However, current knowledge regarding mitophagy relevant to human physiology is still limited. Model organisms such as mice might not be optimal models to recapitulate all the key aspects of human disease phenotypes. The development of the human-induced pluripotent stem cells (hiPSCs) may provide an exquisite approach to bridge the gap between animal mitophagy models and human physiology. To explore this premise, we take advantage of the pH-dependent fluorescent mitophagy reporter, mt-Keima, to assess mitophagy in hiPSCs and hiPSC-derived cardiomyocytes (hiPSC-CMs). We demonstrate that mt-Keima expression does not affect mitochondrial function or cardiomyocytes contractility. Comparison of hiPSCs and hiPSC-CMs during different stages of differentiation revealed significant variations in basal mitophagy. In addition, we have employed the mt-Keima hiPSC-CMs to analyze how mitophagy is altered under certain pathological conditions including treating the hiPSC-CMs with doxorubicin, a chemotherapeutic drug well known to cause life-threatening cardiotoxicity, and hypoxia that stimulates ischemia injury. We have further developed a chemical screening to identify compounds that modulate mitophagy in hiPSC-CMs. The ability to assess mitophagy in hiPSC-CMs suggests that the mt-Keima hiPSCs should be a valuable resource in determining the role mitophagy plays in human physiology and hiPSC-based disease models. The mt-Keima hiPSCs could prove a tremendous asset in the search for pharmacological interventions that promote mitophagy as a therapeutic target.Abbreviations: AAVS1: adeno-associated virus integration site 1; AKT/protein kinase B: AKT serine/threonine kinase; CAG promoter: cytomegalovirus early enhancer, chicken ACTB/ß-actin promoter; CIS: cisplatin; CRISPR: clustered regularly interspaced short palindromic repeats; FACS: fluorescence-activated cell sorting; FCCP: carbonyl cyanide p-trifluoromethoxyphenylhydrazone; hiPSC: human induced pluripotent stem cell; hiPSC-CMs: human induced pluripotent stem cell-derived cardiomyocytes; ISO: isoproterenol; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; RT: room temperature; SB: SBI-0206965; ULK1: unc-51 like autophagy activating kinase 1.

Significance of mitochondrial activity in neurogenesis and neurodegenerative diseases.

Mitochondria play a multidimensional role in the function and the vitality of the neurological system. From the generation of neural stem cells to the maintenance of neurons and their ultimate demise, mitochondria play a critical role in regulating our neural pathways' homeostasis, a task that is critical to our cognitive health and neurological well-being. Mitochondria provide energy via oxidative phosphorylation for the neurotransmission and generation of an action potential along the neuron's axon. This paper will first review and examine the molecular subtleties of the mitochondria's role in neurogenesis and neuron vitality, as well as outlining the impact of defective mitochondria in neural aging. The authors will then summarize neurodegenerative diseases related to either neurogenesis or homeostatic dysfunction. Because of the significant detriment neurodegenerative diseases have on the quality of life, it is essential to understand their etiology and ongoing molecular mechanics. The mitochondrial role in neurogenesis and neuron vitality is essential. Dissecting and understanding this organelle's role in the genesis and homeostasis of neurons should assist in finding pharmaceutical targets for neurodegenerative diseases.

Pharmacological inhibition of USP30 activates tissue-specific mitophagy.

AIM: Mitophagy is the regulated process that targets damaged or dysfunctional mitochondria for lysosomal-mediated removal. This process is an essential element of mitochondrial quality control, and dysregulation of mitophagy may contribute to a host of diseases, most notably neurodegenerative conditions such as Parkinson's disease. Mitochondria targeted for mitophagic destruction are molecularly marked by the ubiquitination of several outer mitochondrial membrane (OMM) proteins. This ubiquitination is positively regulated, in part, by the mitochondrial-targeted kinase PINK1 and the E3 ubiquitin ligase Parkin. In contrast, the reverse phenomenon, deubiquitination, removes ubiquitin from Parkin substrates embedded in the OMM proteins, antagonizing mitophagy. Recent evidence suggests that the mitochondrial deubiquitinase USP30 negatively regulates Parkin-mediated mitophagy, providing opportunities to identify USP30 inhibitors and test for their effects in augmenting mitophagy. Here we will characterize a USP30 inhibitor and demonstrate how the pharmacological inhibition of USP30 can augment stress-induced mitophagic flux. METHODS: We have conducted mitophagy and mitochondrial analyses in cultured cells. We have determined the plasma pharmacokinetics of the USP30 inhibitor in mice and conducted analyses using the mt-Keima mice to measure in vivo mitophagy directly. RESULTS: The compound has minimal mitochondrial toxicity in cultured cells and is tolerated well in mice. Interestingly, we demonstrated tissue-specific induction of mitophagy following USP30 pharmacological inhibition. In particular, pharmacological inhibition of USP30 induces a significant increase in cardiac mitophagy without detriment to cardiac function. CONCLUSION: Our data support the evidence that USP30 inhibition may serve as a specific strategy to selectively increase mitophagic flux, allowing for the development of novel therapeutic approaches.

A Healthy Heart and a Healthy Brain: Looking at Mitophagy.

Mitochondrial dysfunction is a hallmark of aging and is a major contributor to neurodegenerative diseases and various cardiovascular disorders. Mitophagy, a specialized autophagic pathway to remove damaged mitochondria, provides a critical mechanism to maintain mitochondrial quality. This function has been implicated in a tissue's ability to appropriately respond to metabolic and to bioenergetic stress, as well as to recover from mitochondrial damage. A global decline in mitophagic flux has been postulated to be linked to pathological alterations that occur in the heart and the brain as well as a general age-dependent decline in organ function. Cellular observation suggests multiple mechanistically distinct pathways converge upon and activate mitophagy. Over the past decade, additional molecular components within mitophagy have been discovered, including several disease-associated genes that are functionally implicated in mitophagy. However, the pathophysiological role of mitophagy, and how it is regulated within normal physiology or various disease states, is less well established. Here, we will review the evidence that a decline in mitophagy contributes to impaired mitochondrial homeostasis and may be particularly detrimental to postmitotic neurons and cardiomyocytes. We will discuss mitophagy's pathological significance in both neurodegenerative diseases and cardiovascular disorders. Additionally, signaling pathways regulating mitophagy are reviewed, with emphasis placed on how these pathways might contribute to disease progression. Understanding mitophagy's role in the mechanisms of disease pathogenesis should allow for the development of more efficient strategies to battle pathological conditions associated with mitochondrial dysfunction.

Mitophagy in cardiovascular homeostasis.

Mitochondria are essential organelles that generate energy to fuel myocardial contraction. Accumulating evidence also suggests that, in the heart, mitochondria may contribute to specific aspects of disease progression through the regulations of specific metabolic intermediates, as well as the transcriptional and epigenetic states of cells. If damaged, the mitochondria and their related pathways are hindered, which may result in or contribute to the development of a wide range of cardiovascular diseases. Therefore, the maintenance of cardiac mitochondrial function and integrity through specific mitochondrial quality control mechanisms is critical for cardiovascular health. Mitophagy is part of the overall mitochondrial quality control process, and acts as a specialized autophagic pathway that mediates the lysosomal clearance of damaged mitochondria. In response to cardiac stress and injury, the pathways associated with mitophagy are triggered resulting in the removal of damaged mitochondrial, thereby maintaining cardiac homeostasis. In addition, recent studies have demonstrated an essential role for mitophagy in both developmental and disease-related metabolic transitioning of cardiac mitochondria. Here, we discuss the physiological and the pathological roles of mitophagy in the heart, the underlying molecular mechanisms, as well as potential therapeutic strategies based on mitophagic modulation.

Detection of mitophagy in mammalian cells, mice, and yeast.

Selective elimination of superfluous or dysfunctional mitochondria is a fundamental process conserved among both uni- and multicellular eukaryotes, contributing to mitochondrial quality and quantity control. This process depends on autophagy, a cellular self-eating membrane trafficking system, and is thus called mitophagy. In this chapter, we describe methods to detect mitophagy in mammalian cells, mice, and yeast.