Dr. Zhang is professor and director of the Center for Neurologic Diseases at Sanford Burnham Prebys. Prior to that, he was professor and director of the Signature Program in Neuroscience & Behavioral Disorders at Duke-NUS Medical School, Singapore as well as professor of Neuroscience and Neurology, Steenbock Professor in Neural and Behavioral Sciences at the University of Wisconsin-Madison.
Dr. Zhang received his MD and MS in China and PhD in Canada. He is a pioneer in stem cells and regenerative medicine. He has developed technology to guide human stem cells to functionally specialized nerve cell types that are impaired in many neurological and psychiatric conditions with 25 awarded patents and several pending applications. He established the Stem Cell & Genome Editing Core at the UW-Madison and Duke-NUS, serving investigators on campus and beyond. He has also developed stem cell-based platforms for studying neural degeneration and testing drugs for neurological diseases. In parallel, he is developing cell therapy for neurological diseases like Parkinson’s disease, spinal cord injury and stroke. Dr. Zhang was a founding member of the WiCell Institute and co-founder of BrainXell, Inc and BrainXell Therapeutics, Inc.
Education
MD, Wenzhou Medical University, China MS, Shanghai Medical University, China PhD, University of Saskatchewan, Canada
Phenomena or Processes
Brain Aging, Neurodegeneration, Neuroregeneration
Anatomical Systems and Sites
Brain
Research Models
Human Pluripotent Stem Cells, Mouse, Rat
Techniques and Technologies
3D Bioprinting, Bioinformatics, Electrophysiology, Live Cell Imaging, Neural Circuit Tracing, Neural Transplantation, Rodent Behavioral Analysis, Stem Cell Differentiation and Engineering
The Zhang laboratory focuses on addressing how functionally diversified neuronal and glial subtypes are born in the building and rebuilding of our human brain. Over the past decades, they have developed models of neural differentiation from mouse, monkey, and human pluripotent stem cells, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Building upon the success in establishing transgenic and patient stem cells as well as directed neural differentiation to regionally and functionally specialized neuronal and glial subtypes, they are dissecting the cellular and molecular processes underlying brain aging and degeneration, focusing on motor neuron diseases (ALS, SMA), Alexander disease, Down syndrome, Parkinson’s disease and Alzheimer’s disease as well as some rare undiagnosed disorders. They are also transforming these cellular models to templates for drug discovery.
The Zhang laboratory has discovered that appropriately specified neurons project to correct brain regions and connect to the right targets in the adult rodent brain, suggesting a surprisingly regenerative capacity of human stem cell-produced neurons, very much like those born during embryonic development. They have also found that the transplanted human neurons receive appropriate inputs, a process largely dependent on the cell identity. They are currently evaluating the therapeutic potential of human stem cell-generated neural subtypes in animal (including non-human primate) models of Parkinson’s disease, stroke, and spinal cord injury. In particular, they have shown that cell therapy for Parkinson’s disease is safe and effective in a nonhuman primate model. They are now preparing for clinical trial of cell therapy for Parkinson’s disease.
Evan Y. Snyder earned his MD and PhD (in neuroscience) from the University of Pennsylvania in 1980 as a member of NIH’s Medical Scientist Training Program (MSTP). He had also studied psychology and linguistics at the University of Oxford. After moving to Boston in 1980, he completed residencies in pediatrics and neurology as well as a clinical fellowship in Neonatal-Perinatal Medicine at Children’s Hospital-Boston, Harvard Medical School. He also served as Chief Resident in Medicine (1984-1985) and Chief Resident in Neurology (1987) at Children’s Hospital-Boston. In 1989, he became an attending physician in the Department of Pediatrics (Division of Newborn Medicine) and Department of Neurology at Children’s Hospital-Boston, Harvard Medical School. From 1985-1991, concurrent with his clinical activities, he conducted postdoctoral research as a fellow in the Department of Genetics, Harvard Medical School. In 1992, Dr. Snyder was appointed an instructor in neurology (neonatology) at Harvard Medical School and was promoted to assistant professor in 1996. He maintained lab spaces in both Children’s Hospital-Boston and at Harvard Institutes of Medicine/Beth-Israel Deaconess Medical Center. In 2003, Dr. Snyder was recruited to Sanford Burnham Prebys as Professor and Director of the Program in Stem Cell and Regenerative Biology. He then inaugurated the Stem Cell Research Center (serving as its founding director) and initiated the Southern California Stem Cell Consortium. Dr. Snyder is a Fellow of the American Academy of Pediatrics (FAAP). He also received training in Philosophy and Linguistics at Oxford University.
Related Disease
Alzheimer’s Disease, Amyotrophic Lateral Sclerosis (Lou Gehrig’s Disease), Arthritis, Brain Cancer, Brain Injury, Breast Cancer, Cancer, Childhood Diseases, Congenital Disorders of Glycosylation, HIV-Associated Dementia, Huntington’s Disease, Multiple Sclerosis, Muscular Dystrophy, Neurodegenerative and Neuromuscular Diseases, Neurological and Psychiatric Disorders, Parkinson’s Disease, Peripheral Vascular Disease, Skin Cancer and Melanoma, Spinal Cord Injury, Stroke, Traumatic Injury
We believe the study of stem cell biology will provide insights into many areas: developmental biology, homeostasis in the normal adult, and recovery from injury. Indeed, past and current research has already produced data in these areas that would have been difficult or impossible via any other vehicle. We have engaged in a multidisciplinary approach, simultaneously exploring the basic biology of stem cells, their role throughout the lifetime of an individual, as well as their therapeutic potential. Taken together, these bodies of knowledge will glean the greatest benefit for scientists and, most importantly, for patients. All of our research to date has been preformed in animal models with the ultimate goal of bringing them to clinical trials as soon as possible. Stem cells offer an intriguing mix of controversy, discovery, and hope. Politicians are charged with dealing with the controversial facets of stem cells, as we prefer to focus our energy on their potential for discovery and hope.
The Snyder Lab studies stem cell biology, with the goal of understanding normal development, tissue homeostasis, and recovery from injury and disease. A major focus is neural stem cells (NSCs), which can self-renew and differentiate into neurons, astrocytes, and oligodendrocytes. These properties make NSCs ideal for repair of damage due to injury or disease, but they also make them susceptible to transformation into malignant cancers.
Pier Lorenzo Puri earned his MD at the University of Rome “la Sapienza” in 1991. Dr. Puri completed his internship in Internal Medicine at the hospital “Policlinico Umberto I” (Rome) from 1992 to 1997, and defended an experimental thesis on the vascular effects of angiotensin II to graduate as Specialist in Internal medicine at the University of Rome “la Sapienza” in 1997. During this time he was frequently working at the Freien University of Berlin, as visiting scientist at the Deprtment of Biochemistry and Molecular Biology, to perform experiments of protein and DNA microinjection in cultured cells. Dr. Puri trained as a post-doctoral fellow at the University of California San Diego (UCSD), in the department of Cell Biology, under the supervision of Dr. Wang, from 1997 to 2001. He was appointed as Staff Scientist at the Salk Institute (La Jolla) in 2001, and became an Assistant Telethon Scientist at the Dulbecco Telethon Institute in Rome in 2002. He was upgraded to Associate Telethon Scientist at the Dulbecco Telethon Institute in Rome since 2007 and became Senior Telethon Scientist, Dulbecco Telethon Institute, in 2012, but declined this position. Dr. Puri joined Sanford Burnham Prebys as an Assistant Professor in 2004. He has been promoted to Associate Professor in 2010 and full Professor in 2015. From 2008 to 2016 Dr. Puri served as Adjunct Professor of Pediatrics at the University of California, San Diego. From 2008 to 2013 Dr Puri was an Associate Member of Sanford Children’s Health Research Center. Dr Puri has been Director of the laboratory of Epigenetics and Regeneration at Fondazione S. Lucia, Roma, Italy, but stepped down this position since 2019.
Education
University of California San Diego, Postdoctoral, Department of Biology University of Rome La Sapienza, PhD, Internal Medicine University of Rome La Sapienza, MD, Internal Medicine University of Rome La Sapienza, Undergraduate, Internal Medicine
Other Appointments
2020-2024: Member of the Science Advisory Board (SAB) European Commission-funded Consortium BIND (Brain Involvement In Dystrophinopathies) 2015-2019: Standing Member, NIH Study Section (SMEP) 2010-present: Member of Editorial Board of Skeletal Muscle
Phenomena or Processes
Adult/Multipotent Stem Cells, Aging, Cell Biology, Cell Cycle Progression, Cell Differentiation, Cell Signaling, Cellular Senescence, Development and Differentiation, Disease Therapies, DNA Damage Checkpoint Function, Epigenetics, Gene Regulation, Phosphorylation, Regenerative Biology, Signal Transduction, Transcriptional Regulation
Anatomical Systems and Sites
General Cell Biology, Musculoskeletal System
Research Models
Clinical and Transitional Research, Cultured Cell Lines, Human Adult/Somatic Stem Cells, Mouse Embryonic Stem Cells, Mouse Somatic Stem Cells, Primary Human Cells
Techniques and Technologies
Bioinformatics, Cellular and Molecular Imaging, Gene Expression, Genomics
Puri’s lab group investigates the molecular and epigenetic regulation of gene expression in skeletal muscle progenitors and other muscle-resident cell types (including fibro-adipogenic progenitors, cells from the inflammatory infiltrate, cellular components of neuro-muscular junctions) during physiological and pathological perturbations of skeletal muscle homeostasis.
We use molecular, biochemical and epigenetic tools to understand structural and functional principles of the 3D genome organization that regulates gene expression during muscle regeneration and diseases.
A topic of particular interest is the analysis of chromatin interactions that define the 3D genome organization and the identification of structural and functional interactions that regulate cell type-specific patterns of gene expression in response to cues released within the skeletal muscle regenerative environment in health and disease conditions, such as muscular dystrophies and other neuromuscular diseases.
The knowledge derived from our studies is instrumental to elucidate the pathogenesis of muscular disorders and discover pharmacological interventions that promote muscle regeneration to repair diseased muscles.
Current translational focus is devoted to:
the study of the therapeutic potential of HDAC inhibitors for treatment of Duchenne Muscular Dystrophy (DMD)
the identification of genome variants associated to DMD patient-specific patterns of expression of disease-modifier genes that can account for individual trends of disease progression beyond the common genetic deficiency of dystrophin
the effect of dystrophin deficiency and restoration by gene therapy on 3D genome and transcriptional output of DMD myofibers; the therapeutic potential of extracellular vesicles released by fibro-adipogenic progenitors of DMD skeletal muscles exposed to HDACi.
Puri Lab
Pier Lorenzo Puri’s Research Report
Puri’s lab group investigates the molecular and epigenetic regulation of gene expression in skeletal muscle progenitors and other muscle-resident cell types (including fibro-adipogenic progenitors, cells from the inflammatory infiltrate, cellular components of neuro-muscular junctions) during physiological and pathological perturbations of skeletal muscle homeostasis.
We use molecular, biochemical and epigenetic tools to understand structural and functional principles of the 3D genome organization that regulates gene expression during muscle regeneration and diseases
A topic of particular interest is the analysis of chromatin interactions that define the 3D genome organization and the identification of structural and functional interactions that regulate cell type-specific patterns of gene expression in response to cues released within the skeletal muscle regenerative environment in health and disease conditions, such as muscular dystrophies and other neuromuscular diseases.
The knowledge derived from our studies is instrumental to elucidate the pathogenesis of muscular disorders and discover pharmacological interventions that promote muscle regeneration to repair diseased muscles
Current translational focus is devoted to:
the study of the therapeutic potential of HDAC inhibitors for treatment of Duchenne Muscular Dystrophy (DMD)
the identification of genome variants associated to DMD patient-specific patterns of expression of disease-modifier genes that can account for individual trends of disease progression beyond the common genetic deficiency of dystrophin
the effect of dystrophin deficiency and restoration by gene therapy on 3D genome and transcriptional output of DMD myofibers; the therapeutic potential of extracellular vesicles released by fibro-adipogenic progenitors of DMD skeletal muscles exposed to HDACi.
1. Epigenetic regulation of skeletal myogenesis by histone acetyltransferases and deacetylases
Our earlier identification and characterization of acetyltransferases p300/CBP and PCAF, as transcriptional co-activators, and the histone deacetylases HDACs, as transcriptional co-repressors, of the myogenic determination factor MyoD1-3, respectively, inspired the experimental rationale toward exploiting pharmacological inhibition of HDAC to promote skeletal myogenesis.
2. HDAC inhibitors as pharmacological intervention in DMD and other muscular dystrophies
Puri lab discovered that dystrophin-activated nNOS signalling controls HDAC2 activity, thereby revealing a previously unrecognized link between constitutive activation of HDAC2 and alteration of the epigenetic landscape of dystrophin-deficient muscles6,7. This discovery established the rationale for using HDAC inhibitors to counter the progression of Duchenne muscular dystrophy (DMD), by correcting aberrant HDAC activity in dystrophin-deficient muscles8-11.
3. Control of chromatin structure in muscle cells by regeneration-induced signaling pathways
Upon the discovery and characterization of intracellular signaling pathways (i.e. p38, ERK and AKT cascades) that regulate muscle gene expression in myoblasts, in earlier studies during Puri’s postdoctoral training, Puri lab has revealed the mechanism by which muscle environmental cues are converted into epigenetic changes that regulate gene expression in healthy and diseased muscles, via extracellular signal-activated kinase targeting of chromatin-modifying enzymes. These studies provided the first evidence that regeneration activated p38 and AKT signaling cooperatively direct assembly and activation of histone acetyltransferases and chromatin remodeling SWI/SNF complex at myogenic loci in muscle progenitors12,13,15. Moreover, we discovered that regeneration-activated p38 targets Polycomb Repressory Complex (PCR2) at Pax7 locus to promote formation of repressive chromatin during satellite cells a ctivation14.
4. Epigenetic basis for activation of the myogenic program in ESCs and other pluripotent cell types
Puri lab studied the epigenetic determinants of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) commitment to skeletal myogenesis, by investigating the hESC resistance to direct conversion into skeletal muscle upon ectopic expression of MyoD, which can otherwise reprogram somatic cells into the skeletal muscle lineage. These studies showed that hESC and hiPSC resistance to myogenic conversion is caused by the lack of expression of one structural component of the SWI/SNF chromatin remodelling complex – BAF60C – which is specifically induced in embryoid bodies13. Based on these studies, we have recently established a protocol of hESC-derived 3D contractile myospheres that offers the unprecedented opportunity to dissect and analyze the epigenetic dynamics that underlie the formation of skeletal muscles and to identify changes in the epigenome induced by contractile activity in healthy vs dystrophin-deficient myofibers16,20. We have also determined the identity of the general transcription factors implicated in the activation of skeletal myogenesis17, and we have discovered that replicative senescence is associated with acquisition of resistance to MYOD-mediated activation of muscle gene expression, caused by the constitutive activation of DNA damage repair (DDR) response that impairs cell cycle progression and MYOD activity18. Finally, our recent work has elucidated the mechanism by which MYOD regulates high-order chromatin interactions to define the tri-dimensional (3D) nuclear architecture for the activation of skeletal myogenesis during human somatic cell reprogramming into skeletal muscles19.
5. Identification, functional, phenotypic and molecular characterization of muscle-interstitial cells – (the fibroadipogenic progenitors – FAPs) in healthy and diseased muscles.
Our work has elucidated the molecular determinants of the interplay between adult muscle stem cells and cellular components of their functional niche (i.e. FAPs), by identifying regulatory networks implicated in compensatory or pathogenic regeneration, and suggesting “disease stage-specific” responses to pharmacological treatment of neuromuscular disorders, such as DMD. Indeed, we have shown that HDACi promote compensatory regeneration and prevent fibro-adipogenic degeneration in mdx mice at early stages of diseases, by targeting a population of muscle interstitial cells – FAPs8 – and have identified a HDAC-regulated network that controls expression of myomiRs and alternative incorporation of BAF60 variants into SWI/SNF complexes to direct the pro-myogenic or fibro-adipogenic FAP activity21. Furthermore, we have recently identified specific subpopulations of FAPs (subFAPs) in physiological conditions and disease22 and we have discovered that specific subFAPs expand and adopt pathogenic phenotypes upon muscle denervation23 or in muscles of patients affected by type 2 diabetes24.