Dr. Hopper is a Clinical Assistant Professor in the Division of Pediatric Cardiology in the Department of Pediatrics. Dr. Hopper’s clinical responsibilities are focused on the inpatient and outpatient Pulmonary Hypertension (PH) Service based within the Children’s Heart Center as well as the inpatient Cardiology service at LPCH. Additionally, Dr. Hopper pursues clinical and translational research in the area of pulmonary hypertension within the Children's Heart Center at LPCH.
Dr. Hopper received her Bachelor of Arts degree in Molecular Biology from Pomona College in Claremont, California, and she attended medical school at the University of Michigan Medical School, graduating cum laude. She completed her residency in Pediatrics at Boston Children’s Hospital and performed both her fellowship training in Pediatric Cardiology and her advanced clinical fellowship in Pulmonary Hypertension at Lucile Packard Children’s Hospital Stanford. Dr. Hopper was formerly an Assistant Professor of Pediatrics at the Perelman School of Medicine at the University of Pennsylvania and Associate Director of the Pulmonary Hypertension Program in the Division of Cardiology in the Department of Pediatrics at the Children’s Hospital of Philadelphia.
- Pediatric Cardiology
Clinical Assistant Professor, Pediatrics - Cardiology
Associate Director, Pediatric Pulmonary Hypertension Program, Lucile Packard Children's Hospital at Stanford (2017 - Present)
Board Certification: Pediatric Cardiology, American Board of Pediatrics (2014)
Fellowship:Stanford Medicine Div of Pediatric Cardiology (2014) CA
Fellowship:Stanford Medicine Div of Pediatric Cardiology (2013) CA
Board Certification: Pediatrics, American Board of Pediatrics (2010)
Residency:Boston Childrens Hospital Pediatric Residency (2010) MA
Medical Education:University of Michigan Medical School (2007) MI
Fellowship, Stanford (Lucile Packard Children's Hospital), Pediatric Pulmonary Hypertension (2014)
Fellowship, Stanford (Lucile Packard Children's Hospital), Pediatric Cardiology (2013)
Residency, Boston Children's Hospital (Boston Combined Residency Program in Pediatrics), Pediatrics (2010)
MD, University of Michigan Medical School (2007)
BA, Pomona College, Molecular Biology (2001)
Current Research and Scholarly Interests
Pediatric pulmonary hypertension
In Pulmonary Arterial Hypertension, Reduced BMPR2 Promotes Endothelial-to-Mesenchymal Transition via HMGA1 and Its Target Slug
2016; 133 (18): 1783-?
-We previously reported high-throughput RNA sequencing analyses that identified heightened expression of the chromatin architectural factor High Mobility Group AT-hook 1 (HMGA1) in pulmonary arterial (PA) endothelial cells (ECs) from idiopathic PA hypertension (IPAH) patients compared to controls. Since HMGA1 promotes epithelial to mesenchymal transition in cancer, we hypothesized that increased HMGA1 could induce transition of PAECs to a smooth muscle (SM)-like mesenchymal phenotype (EndMT), explaining both dysregulation of PAEC function and possible cellular contribution to the occlusive remodeling that characterizes advanced IPAH.-We documented increased HMGA1 in PAECs cultured from IPAH vs. donor control lungs. Confocal microscopy of lung explants localized the increase in HMGA1 consistently to PA endothelium, and identified many cells double-positive for HMGA1 and smooth muscle 22 alpha (SM22α) in occlusive and plexogenic lesions. Since decreased expression and function of bone morphogenetic protein receptor (BMPR)2 is observed in PAH, we reduced BMPR2 by siRNA in control PAECs and documented an increase in HMGA1 protein. Consistent with transition of PAECs by HMGA1, we detected reduced PECAM-1 (CD31) and increased EndMT markers, αSMA, SM22α, calponin, phospho-vimentin and Slug. The transition was associated with spindle SM-like morphology, and the increase in αSMA was largely reversed by joint knockdown of BMPR2 and HMGA1 or Slug. Pulmonary ECs from mice with EC-specific loss of BMPR2 showed similar gene and protein changes.-Increased HMGA1 in PAECs resulting from dysfunctional BMPR2 signaling can transition endothelium to SM-like cells associated with PAH.
View details for DOI 10.1161/CIRCULATIONAHA.115.020617
View details for Web of Science ID 000375604400008
View details for PubMedID 27045138
RNA Sequencing Analysis Detection of a Novel Pathway of Endothelial Dysfunction in Pulmonary Arterial Hypertension
AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE
2015; 192 (3): 356-366
Pulmonary arterial hypertension is characterized by endothelial dysregulation, but global changes in gene expression have not been related to perturbations in function.RNA sequencing was utilized to discriminate changes in transcriptomes of endothelial cells cultured from lungs of patients with idiopathic pulmonary arterial hypertension vs. controls and to assess the functional significance of major differentially expressed transcripts.The endothelial transcriptomes from seven control and six idiopathic pulmonary arterial hypertension patients' lungs were analyzed. Differentially expressed genes were related to BMPR2 signaling. Those downregulated were assessed for function in cultured cells, and in a transgenic mouse.Fold-differences in ten genes were significant (p<0.05), four increased and six decreased in patients vs.No patient was mutant for BMPR2. However, knockdown of BMPR2 by siRNA in control pulmonary arterial endothelial cells recapitulated six/ten patient-related gene changes, including decreased collagen IV (COL4A1, COL4A2) and ephrinA1 (EFNA1). Reduction of BMPR2 regulated transcripts was related to decreased β-catenin. Reducing COL4A1, COL4A2 and EFNA1 by siRNA inhibited pulmonary endothelial adhesion, migration and tube formation. In mice null for the EFNA1 receptor, EphA2, vs. controls, VEGF receptor blockade and hypoxia caused more severe pulmonary hypertension, judged by elevated right ventricular systolic pressure, right ventricular hypertrophy and loss of small arteries.The novel relationship between BMPR2 dysfunction and reduced expression of endothelial COL4 and EFNA1 may underlie vulnerability to injury in pulmonary arterial hypertension.
View details for DOI 10.1164/rccm.201408-1528OC
View details for Web of Science ID 000359178500017
View details for PubMedID 26030479
BMPR2 Preserves Mitochondrial Function and DNA during Reoxygenation to Promote Endothelial Cell Survival and Reverse Pulmonary Hypertension
2015; 21 (4): 596-608
Mitochondrial dysfunction, inflammation, and mutant bone morphogenetic protein receptor 2 (BMPR2) are associated with pulmonary arterial hypertension (PAH), an incurable disease characterized by pulmonary arterial (PA) endothelial cell (EC) apoptosis, decreased microvessels, and occlusive vascular remodeling. We hypothesized that reduced BMPR2 induces PAEC mitochondrial dysfunction, promoting a pro-inflammatory or pro-apoptotic state. Mice with EC deletion of BMPR2 develop hypoxia-induced pulmonary hypertension that, in contrast to non-transgenic littermates, does not reverse upon reoxygenation and is associated with reduced PA microvessels and lung EC p53, PGC1α and TFAM, regulators of mitochondrial biogenesis, and mitochondrial DNA. Decreasing PAEC BMPR2 by siRNA during reoxygenation represses p53, PGC1α, NRF2, TFAM, mitochondrial membrane potential, and ATP and induces mitochondrial DNA deletion and apoptosis. Reducing PAEC BMPR2 in normoxia increases p53, PGC1α, TFAM, mitochondrial membrane potential, ATP production, and glycolysis, and induces mitochondrial fission and a pro-inflammatory state. These features are recapitulated in PAECs from PAH patients with mutant BMPR2.
View details for DOI 10.1016/j.cmet.2015.03.010
View details for Web of Science ID 000352500800014
View details for PubMedID 25863249
- Neonatal Pulmonary Arterial Hypertension and Noonan Syndrome: Two Fatal Cases with a Specific RAF1 Mutation AMERICAN JOURNAL OF MEDICAL GENETICS PART A 2015; 167A (4): 882-885
FK506 activates BMPR2, rescues endothelial dysfunction, and reverses pulmonary hypertension.
journal of clinical investigation
2013; 123 (8): 3600-3613
Dysfunctional bone morphogenetic protein receptor-2 (BMPR2) signaling is implicated in the pathogenesis of pulmonary arterial hypertension (PAH). We used a transcriptional high-throughput luciferase reporter assay to screen 3,756 FDA-approved drugs and bioactive compounds for induction of BMPR2 signaling. The best response was achieved with FK506 (tacrolimus), via a dual mechanism of action as a calcineurin inhibitor that also binds FK-binding protein-12 (FKBP12), a repressor of BMP signaling. FK506 released FKBP12 from type I receptors activin receptor-like kinase 1 (ALK1), ALK2, and ALK3 and activated downstream SMAD1/5 and MAPK signaling and ID1 gene regulation in a manner superior to the calcineurin inhibitor cyclosporine and the FKBP12 ligand rapamycin. In pulmonary artery endothelial cells (ECs) from patients with idiopathic PAH, low-dose FK506 reversed dysfunctional BMPR2 signaling. In mice with conditional Bmpr2 deletion in ECs, low-dose FK506 prevented exaggerated chronic hypoxic PAH associated with induction of EC targets of BMP signaling, such as apelin. Low-dose FK506 also reversed severe PAH in rats with medial hypertrophy following monocrotaline and in rats with neointima formation following VEGF receptor blockade and chronic hypoxia. Our studies indicate that low-dose FK506 could be useful in the treatment of PAH.
View details for DOI 10.1172/JCI65592
View details for PubMedID 23867624
Use of P-32 To Study Dynamics of the Mitochondrial Phosphoproteome
JOURNAL OF PROTEOME RESEARCH
2009; 8 (6): 2679-2695
Protein phosphorylation is a well-characterized regulatory mechanism in the cytosol, but remains poorly defined in the mitochondrion. In this study, we characterized the use of (32)P-labeling to monitor the turnover of protein phosphorylation in the heart and liver mitochondria matrix. The (32)P labeling technique was compared and contrasted to Phos-tag protein phosphorylation fluorescent stain and 2D isoelectric focusing. Of the 64 proteins identified by MS spectroscopy in the Phos-Tag gels, over 20 proteins were correlated with (32)P labeling. The high sensitivity of (32)P incorporation detected proteins well below the mass spectrometry and even 2D gel protein detection limits. Phosphate-chase experiments revealed both turnover and phosphate associated protein pool size alterations dependent on initial incubation conditions. Extensive weak phosphate/phosphate metabolite interactions were observed using nondisruptive native gels, providing a novel approach to screen for potential allosteric interactions of phosphate metabolites with matrix proteins. We confirmed the phosphate associations in Complexes V and I due to their critical role in oxidative phosphorylation and to validate the 2D methods. These complexes were isolated by immunocapture, after (32)P labeling in the intact mitochondria, and revealed (32)P-incorporation for the alpha, beta, gamma, OSCP, and d subunits in Complex V and the 75, 51, 42, 23, and 13a kDa subunits in Complex I. These results demonstrate that a dynamic and extensive mitochondrial matrix phosphoproteome exists in heart and liver.
View details for DOI 10.1021/pr800913j
View details for Web of Science ID 000266719400008
View details for PubMedID 19351177
Mitochondrial matrix phosphoproteome: Effect of extra mitochondrial calcium
2006; 45 (8): 2524-2536
Post-translational modification of mitochondrial proteins by phosphorylation or dephosphorylation plays an essential role in numerous cell signaling pathways involved in regulating energy metabolism and in mitochondrion-induced apoptosis. Here we present a phosphoproteomic screen of the mitochondrial matrix proteins and begin to establish the protein phosphorylations acutely associated with calcium ions (Ca(2+)) signaling in porcine heart mitochondria. Forty-five phosphorylated proteins were detected by gel electrophoresis-mass spectrometry of Pro-Q Diamond staining, while many more Pro-Q Diamond-stained proteins evaded mass spectrometry detection. Time-dependent (32)P incorporation in intact mitochondria confirmed the extensive matrix protein phosphoryation and revealed the dynamic nature of this process. Classes of proteins that were detected included all of the mitochondrial respiratory chain complexes, as well as enzymes involved in intermediary metabolism, such as pyruvate dehydrogenase (PDH), citrate synthase, and acyl-CoA dehydrogenases. These data demonstrate that the phosphoproteome of the mitochondrial matrix is extensive and dynamic. Ca(2+) has previously been shown to activate various dehydrogenases, promote the generation of reactive oxygen species (ROS), and initiate apoptosis via cytochrome c release. To evaluate the Ca(2+) signaling network, the effects of a Ca(2+) challenge sufficient to release cytochrome c were evaluated on the mitochondrial phosphoproteome. Novel Ca(2+)-induced dephosphorylation was observed in manganese superoxide dismutase (MnSOD) as well as the previously characterized PDH. A Ca(2+) dose-dependent dephosphorylation of MnSOD was associated with an approximately 2-fold maximum increase in activity; neither the dephosphorylation nor activity changes were induced by ROS production in the absence of Ca(2+). These data demonstrate the use of a phosphoproteome screen in determining mitochondrial signaling pathways and reveal new pathways for Ca(2+) modification of mitochondrial function at the level of MnSOD.
View details for DOI 10.1021/bi052475e
View details for Web of Science ID 000235792300008
View details for PubMedID 16489745