Dr. Leigh Botly
Dr. Shu-Hong Li
Dr. Jun Wu
Dr. Faisal Alibhai: Post-Doctoral Fellow
Aging is associated with a decline in a number of physiological systems which together lead to impaired cardiac repair following a heart attack. My research focuses on understanding the molecular mechanisms underlying the age-associated decline in cardiac repair, and whether rejuvenation can improve these repair processes. Recently, we have identified an important role of senescent cell-derived extracellular vesicles in impairing key repair processes. Using next generation senolytic therapies we are investigating how transfer of senescent vesicle cargo affects cellular function, and whether removal of senescent cells is sufficient to rejuvenate aged individuals. Together these studies will help to establish rejuvenation as a novel and effective therapy for treatment of heart disease in the aged population.
Dr. Azadeh Yeganeh: Post-Doctoral Fellow
Cardiovascular disease is the leading cause of death worldwide and its prevalence increases with age. Stem cell therapy is one of the proposed methods for rejuvenating and repairing the old heart following heart attack. However, old donor stem cells tend to decline in their regenerative ability with age. Among these declining abilities is autophagy, a critical cellular recycling process. My research involves identifying mechanisms of action underlying rejuvenation of the aged heart during stem cell therapy by studying autophagy. We found that active autophagy in young stem cells plays a critical role in aged heart rejuvenation. The outcome of this study will help to develop new strategies to improve the efficacy of cell therapy by improving autophagy of donor cells, which consequently will help improve host cell autophagy and rejuvenate the heart.
Dr. Stephanie Tobin: Post-Doctoral Fellow
I am interested in the systemic molecular and epigenetic pathways responsible for cellular aging. To do this, we use a technique called bone marrow reconstitution, where aged mouse bone marrow is replaced with young bone marrow cells. These bone marrow cells migrate to peripheral tissues and contribute to a variety of downstream lineages such as inflammatory cells, which are a primary focus of my studies. Inflammatory cells communicate with tissue-resident cells and may influence cell fate decisions and regulate tissue repair. I investigate the rate and mechanism of tissue repair using models of heart disease and skeletal muscle injury, after bone marrow transplantation. With these tools we can understand how bone marrow age influences tissue homeostasis and recovery.
Tina Binesh Marvasti: MD-PhD Candidate
My research interests revolve around understanding and developing novel cellular based therapies for heart failure. Currently we have identified that cardiac patients' CD34+ bone marrow stem cells reconstitute the heart and pre-condition the myocardium to prevent dysfunction following infarction. We have also developed a mouse model with human hematopoietic and endothelial progenitor cells reconstituting the bone marrow of the NSG mice in order to better understand the mechanism and function of these cells in vivo. Restoration of CD34+ cells in older patients is a promising avenue for preventing cardiac dysfunction post-MI.
Lukasz Wlodarek: PhD Candidate
My research involves using bone marrow stem cells to biologically rejuvenate (age-reverse) brain function in geriatric rodents. So far, I have demonstrated that bone marrow stem cells cross the blood-brain barrier and home to the brain where they differentiate into functional glial cells. These bone marrow-derived glial cells improve hippocampal-dependent learning and memory in aged mice by enhancing electrophysiological function of pyramidal cells in the hippocampus. Currently we are attempting to reverse age-induced cognitive decline in geriatric mice using human stem cells with promising preliminary findings. Ideally, we would like to translate this research into clinical trials down the road.
Zhi Cui: PhD Candidate
Mending the heart? We got this. My research interest is to develop a biocompatible, biodegradable, and more importantly electrically conductive material to repair the conduction problem of infarct heart. Scar tissue is stiff and non-conductive, acting as a barrier for normal electrical conduction pattern. With the assistance of this biocompatible conductive biomaterial, polypyrrole-chitosan (PPY-CHI), we are aiming to improve the conduction property of scar tissue and restore normal conduction pattern of infarct heart.
Dr. Shanglin Chen, MD: PhD Candidate
Electrical impulses from the myocardium cause the heart to contract. Severe cardiac conduction disorders, such as wide QRS complex myocardial infarction (MI) and premature ventricular contractions post MI, are associated with poor prognosis. My work focuses on synthesizing a novel biodegradable, bio-engineered and conductive scaffold which will improve the cardiomyocyte electrical propagation and restore the cardiac function after a myocardial infarction to regenerate a damaged heart. Cutting-edge research on biomaterial and tissue engineering taking place at our lab has the potential to change how we treat cardiovascular disease.
Dr. Chongyu Zhang, MD: PhD Candidate
My research is focused on developing a conductive biomaterial polymer to re-establish electric signaling propagation through the infarct region of the heart to synchronize contraction and restore ventricular function. We used gelatin, which is a major component of the extracellular matrix, to create a novel conductive polymer by grafting poly-AMBA onto a gelatin backbone (PAMB-G). Injection of AMBA-G into the scar zone of a heart (post-myocardial infarction) decreased fibrotic tissue impedance and prevented re-entry induced cardiac arrhythmia.
Fievel Lim: Master's Candidate
My research involves looking at the effects of aging on cardiac repair after heart attack. The main scope of my research is focused on the extracellular vesicles produced by mesenchymal stem cells, which contain a variety of bioavailable molecules capable of influencing cellular function. While there are current therapies using these stem cells and their vesicle cargo, the effects of aging on such processes have not yet been investigated. By looking at these vesicles in young and old models, we hope to elucidate the mechanisms by which age affects the reparative capacity of these stem cells, and possibly look to reverse these effects.
Daniel Ramnath: Master's Candidate
My research interest falls within the fields of tissue engineering, biomaterials and conductive polymers. We've constructed a conductive polymer hydrogel aimed at preventing fatal arrhythmias post-myocardial infarction, in order to combat ventricle fibrillation. Mechanistic and functional studies have demonstrated that the hydrogel improves heart function and electrically interacts within the myocardial scar. Conductive biomaterials intended for cardiac repair show promising results that can reduce the likelihood of fatal events post-myocardial infarction.
Riasad Aziz: Master's Candidate
My research interests lie in the application of tissue engineering approaches to enhance physiological performance in humans. Specifically, my projects revolve around the synthesis and characterization of novel scalable and biocompatible conductive polymer-based biomaterials for cardiac repair. Outside of the lab, I enjoy hiking, archery, gaming, finding new genres of music to jam to and playing my guitar.
Anne Fu: Master's Candidate
Tissue engineering and biomaterials offer a novel therapeutic alternative to current available treatments. Our lab has shown that the conductive biomaterial polypyrrole-chitosan (PPY-CHI) synchronizes cardiomyocyte contraction and improves electrical signaling after myocardial infarction. To further investigate this material, my research focuses on elucidating the mechanism by which PPY-CHI can enhance electrical propagation across the cardiac scar tissue.
Alyssa Belfiore: Master's Candidate
My research interest revolves around stem cells and rejuvenation. It is well known that there is a timely and regulated immune response after a heart attack to promote healing, a process that becomes abnormal with age. My work focuses on the use of young extracellular vesicles as a way to rejuvenate aged inflammatory cells. The potential of this therapy is to use rejuvenation of cells central to healing as a way to prevent cardiac dysfunction post-MI in the aged population.
Sean Millar: HBSc. Candidate
UHN Research Trainee and renkelilab.com website creator.