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LUNG T32

Current Trainees

Training History

Program Eligibility

& Nominations

Dr. Asrar B Malik


Program Director

Department of Pharmacology

Center for Lung and Vascular Biology

University of Illinois College of Medicine

835 S Wolcott Ave E403

Chicago, IL 60612


               Tel:          (312) 996-7635

               Fax:         (312) 996-1225

               E-mail:    abmalik@uic.edu

PREDOCTORAL TRAINEES

Cassandre Coles

Advisors:  Richard Minshall, PhD and Irena Levitan, PhD

(1st year supported in training program)

Title:  Role of Caveolae in Endothelial Lipid Transport

Abstract:  The uptake and transport of lipids from the lumen to the sub-endothelium is important in vascular and lung diseases.  We demonstrated the critical role of caveolin-1 in endothelial uptake of lipids. Cav1-/-/ApoE-/- mice showed decrease in atherosclerotic plaque formation when compared to ApoE-/- mice, whereas EC specific overexpression of Cav-1 in mice leads to increase in lipid accumulation in the vessel wall, indicating endothelial caveolin-1 plays an important role in lipid transport in endothelial cells. As little is known about the role of caveolin-1 in atherosclerosis progression, utilizing EC specific inducible Cav-1 knockout mice we are investigate the role of caveolin-1 at each stage of atherosclerosis. Currently, we are generating Scl.Cre+/+/Cav-1lox/lox/ApoE-/- mice to induce the deletion of EC-Cav-1 in an age-dependent manner in mice to study this question.  

We are also investigating modifications to caveolin-1 and the caveolae endocytotic machinery in human ECs following exposure to oxLDL (100 µg/ml). Preliminary data demonstrate that oxLDL-induces an increase in the phosphorylation of Cav-1 (pY14) and eNOS (pS1177), which are integral post-translational modifications in the formation and release of caveolae (Zimnicka et al., 2016). Also, 30 min exposure to oxLDL had no effect on the interaction between β-catenin and VE-cadherin or their expression, which suggests that short-term exposure of ECs to oxLDL and subsequent uptake is independent of AJ disruption.


We also demonstrated that disturbed flow (DF) induces an increase in oxLDL uptake in human ECs. To determine whether physiological blood flow patterns promote post-translational modifications to Cav-1, we exposed human ECs for short (30 min) and long (48 hr) durations. Preliminary studies revealed that when ECs are exposed to 30 min of LF or DF (as compared to static conditions), there was no significant difference in Cav-1 pY14, while eNOS pS1177 increased. When human ECs were exposed to disturbed flow (DF) for 48 hr, we observed a decrease in Cav-1 pY14 and an increase in total caveolin-1 expression level. In these ongoing studies, we are conducting a thorough time course analysis of the effect of DF and laminar flow (LF) on caveolin-1 and its modifications.

James Hyun

Advisor:  Asrar Malik, PhD

(2nd year supported in training program)

Title:  The role of Hif-1α in endothelial differentiation and specification and vascular repair

Abstract:  The generation of functional arterial endothelial cells (aECs) derived from ESCs holds great promise for vascular tissue engineering. However, the mechanisms underlying their generation and the potential of aECs in re-vascularizing ischemic tissue are not fully understood. We observed that hypoxia exposure of mouse ESCs in contrast to normoxa induced an initial phase of Hif1α-mediated upregulation of the transcription factor Etv2 that resulted in commitment to the EC fate. However, sustained activation of Hif-1α in the EC progenitors thereafter induced Notch1 that promoted the transition to aEC fate. We observed aECs specifically mediated arteriogenesis in the mouse hindlimb ischemia model. Transplantation of the generated aECs also showed persistent sequestration in ischemic myocardium and restored cardiac function in mice in contrast to ECs derived under normoxia. Therefore, Hif-1α activation of Etv2 in ESCs followed sequentially by Notch1 signaling is required for the generation aECs that are capable of arteriogenesis and re-vascularization. These results may be important as a strategy for re-vascularizing ischemic lung tissue.

Vanessa Juettner

Advisor:  Yulia Komarova, PhD

(2nd year supported in training program)

Title:  VE-PTP stabilization of lung endothelial adherens junctions (AJs) through activation of Rac1

Abstract:  The Vascular Endothelial Protein Tyrosine Phosphatase (VE-PTP) is an endothelial-specific phosphatase that dephosphorylates multiple proteins including Vascular Endothelial (VE)-cadherin, the main adhesion protein of adherens junctions (AJ). However, the role of VE-PTP in stabilization of VE-cadherin adhesion complexes remains unclear. VE-cadherin establishes adhesion events through trans interactions with opposing VE-cadherin molecules at AJs. In resting endothelial monolayers, it undergoes continues exchange between junctional and cytosolic pools. Using VE-cadherin tagged with the photoconvertable protein Dendra2, we have demonstrated that VE-PTP regulates steady-state kinetics of VE-cadherin at AJs in a phosphatase-independent manner. Overexpression of wild-type (WT) or phosphatase “dead” VE-PTP mutant similarly decreased the VE-cadherin dissociation rate from AJs as compared to control cells expressing empty vector. In agreement with these results, VE-PTP depletion increased VE-cadherin dissociation rate from AJs. Furthermore, treatment of the cells with the VE-PTP phosphatase inhibitor, AKB-9785, did not alter VE-cadherin dynamics suggesting that VE-PTP promoted stability of VE-cadherin adhesion by decreasing VE-cadherin dissociation rate in a phosphatase-independent manner. Because Rac1 stabilizes AJs by reducing mechanical tension across VE-cadherin adhesion, we analyzed junctional activity of Rac1 as well as the tension applied to VE-cadherin using respective FRET biosensors. We observed that overexpression of VE-PTP caused both Rac1 activation at AJs and reduction of tension across VE-cadherin adhesion. Consistent with these results, VE-PTP knockdown decreased Rac1 activity at AJs and increased stress at AJs determined using micropillar arrays. Cumulatively, our data suggest a scaffold role of VE-PTP in regulating Rac1 activity at AJs. Future studies will investigate the molecular mechanisms by which VE-PTP activates Rac1 and regulates endothelial barrier integrity.

Sarah Krantz

Advisor:  Jalees Rehman, MD

(2nd year supported in training program)

Title:  Metabolic aspects of thrombin-induced pulmonary vascular permeability regulation

Abstract:  Our preliminary data suggest that a metabolic shift in endothelial cells occurs during LPS induced lung vascular injury and that increased glycolysis is beneficial. One likely explanation is that mitochondria cannot reach the cell periphery because they are integrated into a mitochondrial network whereas glycolytic enzymes are mobile and can provide ATP to the cell periphery including the vascular adherens junctions that constitute the endothelial barrier. We would therefore like to cross the homozygous LoxP-Mfn2 and LoxP-PFKFB3 mice with Scl-Cre mice to specifically delete endothelial Mfn2 or PFKFB3, thus allowing us to access the role of Mfn2 and/or PFKFB3 in endothelial barrier function. These mice will  be compared to each other (LoxP-Mfn2-Scl-Cre compared to LoxP-PFKFB3-Scl-Cre) to elucidate wether endothelial gylcolysis or mitochondrial networking is required in the maintenance and recovery of endothelial barrier function.  We hypothesize that endothelial-specific Mfn2-/- mice will show improved recovery because these mice will have defective mitochondrial oxidation and rely on increased glycolysis. Conversely, we believe that endothelial-specific PFKFB3-/- mice show diminished recovery because they will provide inadequate glycolysis.

Victoria Mastej
Advisor:  Kishore Wary, PhD

(1st year supported in training program)

Title:  Role of Lymphatic KLF4 Expression in Sepsis

Abstract:  Cardiovascular disease and systemic septic infections both continue to contribute to death and disability in the United States. Patients that have been treated for sepsis are at an increased risk of death within 3-6 months of being released from hospitals; one third of these deaths are due to cardiovascular disease. Sepsis shares several hallmarks of disease with atherosclerosis, including immune dysregulation, increased thrombogenesis, and systemic inflammation. Commonly, acute endothelial inflammation, lung edema, and cardiovascular organ failure are seen in severe sepsis. The normal functions of lymphatic vascular system including draining excess fluids from organs and extremities; lymphatic disorders can lead to edema, as well. Transcription factor Krüppel-like factor 4 (KLF4) has been been shown to be atheroprotective in arterial endothelial cells, however, its role in lymphatic endothelial cells remains unexplored. Using in vitro lymphatic endothelial cells and in vivo genetically modified mouse models, I will study the effects sepsis may have on lymphatically expressed KLF4, and elucidate the unknown role of lymphatic KLF4 in sepsis and cardiovascular organ failure.

Ian Rochford

Advisor:  Dolly Mehta, PhD

(1st year supported in training program)

Title:  Epigenetic Regulation of Macrophage Lineage Specification During Acute Lung Injury and Resolution

Abstract:  I am working defining the role of CD11b+ resident macrophages in the resolution of acute lung injury. During the course of inflammatory lung injury monocytes are recruited to the site of inflammatory cytokine production where they differentiate into macrophages. The molecular signals by which these newly arisen macrophages coordinate the resolution of inflammation and the repair of vascular leak brought on by endothelial barrier disruption have yet to be elucidated. Similarly, how the epigenetic landscape and metabolism of these differentiated cells and their progenitors changes in response to recruitment to the lung has yet to be clearly defined.  We are working to describe the interplay between epigenetic regulation, metabolomics, and macrophage polarization

Kilian Sottoriva

Advisor:  Kostandin Pajcini, PhD

(1st year supported in training program)

Title: Targeting the TAD domain and studying its role in Notch1 signaling

Abstract:  Notch signaling is an evolutionary conserved pathway involved in diverse events such as development, cell fate determination, and angiogenesis. Notch is a unique protein in that it functions as a receptor at the plasma membrane and, after ligand induced cleavage, a transcription factor in the nucleus. The roles that several Notch1 domains play in this tightly regulated pathway have already been determined. Our lab has demonstrated that deletion of the transcriptional activation domain (TAD) does not entirely ablate Notch1 signaling, but does provides interference. This dampening of Notch1 signaling would be advantageous in situations with aberrant signaling levels. Through genetic manipulation, the ability of deleting the TAD to diminish, but not completely abolish, Notch1 signaling will be evaluated. Such work would provide a novel target against hyperactive Notch signaling.