Cytoskeleton, Adhesion and Motility
Research on the cytoskeleton, cell adhesion and motility, with particular emphasis on changes that accompany disease states.
Labs in This Area
Studying espins and the elucidation of their roles in the stereocilia of sensory hair cells in the inner ear
The research in my lab is centered on the “espins,” a novel family of actin-bundling proteins and the elucidation of their roles in the stereocilia of sensory hair cells in the inner ear. Espins are produced in multiple isoforms from a single gene. They are present at high concentration in the parallel actin bundle scaffold at the core of hair cell stereocilia and are the target of deafness mutations in mice and humans.
For lab information and more, please see Dr. Bartles’ faculty profile.
See Dr. Bartles' publications on PubMed.
Contact Dr. Bartles at 312-503-1545.
Cancer stem cell biology, cellular signaling and therapy responses in human brain tumors, in particular, glioblastoma (GBM)
Integrated genomic analysis by TCGA revealed tat GBMs can be classified into four clinically relevant subtypes, proneural (PN), neural, mesenchymal (Mes) and classical GBMs with each characterized by distinct gene expression signatures and genetic alterations. We reported that PN and Mes glioma stem cells (GSCs) subtypes also have distinct dysregulated signaling pathways. Our current research focuses on novel mechanisms/cellular signaling of GSC biology, tumorigenesis, progression, invasion/metastasis, angiogenesis and therapy responses of GSCs and GBMs.
1. MicroRNAs (miRs) and non-coding RNAs in GSCs and GBMs – miRs and other small non-coding RNAs act as transcription repressors or inducers of gene expression or functional modulators in all multicellular organisms. Dysregulated miRs/noncoding RNAs plays critical roles in cancer initiation, progression and responses to therapy. We study the mechanisms by which deregulated expression of miRs influence GBM malignant phenotypes through interaction with signaling pathways, that in turn, influence proneural (PN)- and mesenchymal (Mes)-associated gene expression in GSCs and GBM phenotypes. We study the molecular consequences and explore clinical applications of modulating miRs and signaling pathways in GBMs. We are establishing profiles of non-coding RNAs in these GSCs and study mechanisms and biological influences of these non-coding RNAs in regulating GSC biology and GBM phenotypes. In addition, we explore novel therapeutic approaches of delivery of tumor suppressive miRs into GSC brain xenografts in animals.
2. Autophagy in GBMs. (Macro)autophagy is an evolutionally conserved dynamic process whereby cells catabolize damaged proteins and organelles in a lysosome-dependent manner. Autophagy principally serves as an adaptive role to protect cells and tissues, including those associated with cancer. Autophagy in response to multiple stresses including therapeutic treatments such as radiation and chemotherapies provides a mechanism for tumor cell to survive and acquire resistance to therapies. Tumors can use autophagy to support and sustain their proliferation, survival, metabolism, invasiveness, metastasis and resistance to therapy. We study mechanisms by which phosphorylation, acetylation and ubiquitination of autophagy proteins regulate GSC and GBM phenotypes and autophagic response, which, in turn contributes to tumor cell survival, growth and resistance to therapy. We investigate whether disruption of these post-translational processes on autophagy proteins inhibits autophagy and enhances the efficacy of combination therapies for GBMs. We examine whether cross-talks between miRs, autophagy and oncogenic signaling pathways regulate GSC stemness and phenotypes.
3. Heterogeneity, epigenetic regulation, DNA damage and metabolic pathways in GSCs and GBMs. Intratumoral heterogeneity is a characteristic of GBMs and most of cancers. Phenotypic and functional heterogeneity arise among GBM cells within the same tumor as a consequence of genetic change, environmental differences and reversible changes in cell properties. Subtype mosaicism within the same tumor and spontaneous conversion of human PN to Mes tumors have been observed in clinical GBMs. We explore an emerging epigenetic marker with distinct functions such as DNA methylation together with genetic mapping of these markers to assess their contributions to GBM heterogeneity. In addition, compared with PN GSCs, DNA damage and glycolytic pathways are aberrant active in Mes GSCs. We investigate the mechanisms by which these pathways regulate GSC and GBM phenotypes and responses to therapies.
4. Oncogenic receptor tyrosine kinase (RTKs) signaling, small Rho GTPase regulators in GBM and GSCs: Small Rho GTPases such as Rac1 and Cdc42 modulate cancer cell migration, invasion, growth and survival. Recently, we described mechanisms by which EGFR and its mutant EGFRvIII and PDGFR alpha promote glioma growth and invasion by distinct mechanisms involving phosphorylation of Dock180, a Rac-specific guanidine nucleotide exchange factor (GEF) and DCBLD2, an orphan membrane receptor. We are currently investigating involvement of other modulators/GEFs and other Rho GTPases in modulating GSC and GBM phenotypes and responses to therapy.
View Dr. Cheng's complete list of publications in PubMed.
Shi-Yuan Cheng, PhD at 312-503-5314
Visit us on campus in the Lurie Building, Room 6-119, 303 E Superior Street, Chicago, Illinois 60611.
Studying molecular motors and cell motility
Movement is a fundamental characteristic of life. Cell movement is critical for normal embryogenesis, tissue formation, wound healing and defense against infection. It is also an important factor in diseases such as cancer metastasis and birth defects. Movement of components within cells is necessary for mitosis, hormone secretion, phagocytosis and endocytosis. Molecular motors that move along microfilaments (myosin) and microtubules (dynein) power these movements. Our goal is to understand how these motors produce movement and are regulated. We wish to define their involvement in intracellular, cellular and tissue function and disease—with the long-term goal of developing therapies for the treatment of diseases caused by defects in these molecular motors.
Our work involves the manipulation of myosin and dynein function in the single celled eukaryote Dictyostelium, cultured mammalian cells and transgenic and knockout mice. Yeast two-hybrid screens to identify proteins that interact with or regulate myosin and dynein and characterization of gene expression are being used to define the pathways regulating myosin and dynein. To analyze the biological significance of myosin and dynein, we use confocal and digital microscopy of living cells, analysis of cell movement, vesicle transport and cell division. We employ biochemical techniques including heterologous expression, enzyme purification and characterization and analysis of how phosphorylation state affects physiological function. We are pursuing signal transduction studies to understand the physiologically important pathways that regulate cell motility and biophysical studies such as in vitro motility assays to understand how these molecular motors function at the molecular level.
For lab information and more, see Dr. Chisholm's faculty profile.
See Dr. Chisholm's publications on PubMed.
Contact Dr. Chisholm at 312-503-3209.
Focusing on the mechanisms underlying neurite degeneration and synapse loss in Alzheimer’s disease and related neurodegenerative disorders
Our work focuses on the mechanisms underlying neurite degeneration and synapse loss in Alzheimer’s disease and related neurodegenerative disorders. We are interested in the relationship between beta-amyloid deposition and the progressive formation of dystrophic neurites and cell death in hippocampal neurons.
Recently, we have determined that the microtubule associated protein tau plays an essential role in beta-amyloid-induced neurite degeneration. These results constitute the first direct evidence of a mechanistic link between beta-amyloid deposition and tau in central neurons. Furthermore, our results indicated that beta-amyloid induces calpain-mediated tau cleavage leading to the generation of a 17 kDa neurotoxic fragment in hippocampal neurons both in culture model systems and in AD human brain samples. Currently, we are analyzing the mechanisms by which this tau fragment mediates beta-amyloid-induced neurite degeneration. These studies are being performed by means of a variety of cell and molecular biology techniques.
See Dr. Ferreira's publications on PubMed.
Contact Dr. Ferreira at 312-503-8250.
Discovering how multiple motors on the surface of the same cargo work together in organelle movement, how these motors are attached to the surface of organelles and what regulates their activity
One of the remarkable features of eukaryotic cells is their ability for rapid transport of intracellular organelles in the cytoplasm. Examples of such transport include segregation of chromosomes during cell division and the transport of organelles in neurons from the cell body into axons and dendrites. Movements of organelles are powered by molecular motors. Microtubule motors(kinesins and dyneins) move along microtubules and myosins move along microfilaments.
We use two cellular models to discover how multiple motors on the surface of the same cargo work together in organelle movement and how these motors are attached to the surface of organelles and what regulates their activity. One model is cultured pigment cells (melanophores). These cells activate movement of pigment organelles in response to hormone-modulated changes of cAMP concentration. The movement of pigment organelles is powered by three different motors (two microtubule motors of different polarity and a myosin) and this system is very convenient for analysis of motor regulation. A second model is cultured Drosophila cells that we use to individual components of transport machinery by using RNAi. In our work, we employ techniques of cell and molecular biology and computer-assisted microscopy of living cells and purified organelles as well as high-resolution and high-sensitivity biophysical methods.
See Dr. Gelfand's publications on PubMed.
Contact Dr. Gelfand at 312-503-0530.
Studying the intermediate filament (IF) system in fibroblasts, epithelial cells and nerve cells through biochemical, morphological, immunological, cell physiological and molecular techniques.
We focus on the structure and function of cytoskeletal systems, particularly the intermediate filament (IF) system in fibroblasts, epithelial cells and nerve cells. IFs are composed of large families of proteins that vary in composition from one cell type to another, even among cells in the same tissue. Using a variety of techniques, we have demonstrated that IFs form elaborate networks that course throughout the cytoplasm and establish connections with both the nuclear and cell surfaces.
At the nuclear surface, they are linked either directly or indirectly with the nuclear lamins, which are chromatin-associated IF protein family members. At the level of the plasma membrane, IFs are involved as cytoskeletal linkages to the focal adhesion of fibroblasts and the desmosomes and hemidesmosomes of epithelial cells. Throughout the cytoplasm, we have shown that IFs are associated with the other cytoskeletal elements, such as microtubules and microfilaments.
Our approach to studying the IF system involves biochemical, morphological, immunological, cell physiological and molecular techniques. Our hypothesis is that the IF system forms a continuous network linking the nuclear and cell surfaces, functioning in such diverse activities as the establishment and maintenance of cell shape, organelle movements within the cytoplasm, nuclear positioning, nuclear-cytoplasmic interactions and signal transduction.
Since many human diseases have been linked to changes in cytoskeletal IF systems, we are also developing models to study the mechanisms involved in IF alterations in various diseases. One example is amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease) in which we have been able to induce neurofibrillary tangles to form in single cultured nerve cells. These tangles are similar to those found in ALS neurons. Therefore, we are able to study the effects of neurofilament tangle formation in single cells. During the summer, researchers from this laboratory also conduct studies on the mechanisms of chromatin/nuclear envelope interactions in eggs of the surf clam at the Marine Biological Laboratory in Woods Hole.
See Dr. Goldman's publications on PubMed.
Contact Dr. Goldman at 312-503-4215.
The Gottardi Lab investigates how cells adhere to each other and how this adhesion is regulated and controls gene expression in heath and disease.
The ability of individual cells to adhere and coalesce into distinct tissues is a major feature of multicellular organisms. Research in my laboratory centers on a protein complex that projects from the cell surface and forms a structural “Velcro” that holds cells to one another. This complex is comprised of a transmembrane “cadherin” component that mediates Ca++-dependent homophilic recognition and a number of associated “catenins” that link cadherins to the underlying cytoskeleton. A major focus in our lab is to understand how these catenins direct static versus fluid adhesive states at the plasma membrane, as well as gene expression and differentiation in the nucleus. These basic questions are shedding new light on how dysregulation of the cadherin/catenin adhesion system drives pathologies such as asthma, fibrosis and cancer.
See Dr. Gottardi's publications in PubMed.
For more information, please see Dr. Gottardi's faculty profile.
Cell-to-cell adhesion molecules' integration of mechanical and signaling functions in skin and heart differentiation, disease and cancer.
Dr. Green's research program focuses on how cell-cell adhesion molecules and their associated proteins integrate mechanical and chemical signaling pathways to contribute to the development and maintenance of multicellular tissues. In particular they are investigating how specialized intercellular junctions called desmosomes are assembled and function in ways that transcend their classic textbook definition as spot welds. The lab has shown that desmosomal cadherins help control the balance of proliferation and differentiation and even regulate the production of cytokines that participate in paracrine signaling. Loss of this “brake” results in increased allergic and inflammatory pathways that underlie pathogenesis in inherited disease and possibly cancer, including melanoma. Desmosomes also integrate the functions of other intercellular junctions including gap junctions and interfering mutations can cause lethal heart arrhythmias.
The lab uses a multi-faceted approach, including but not limited to collaborative atomic structure determinations, molecular genetics, live cell imaging, human tissue engineering and gene targeting approaches. Dr. Green serves as Associate Director for Basic Sciences in the R.H. Lurie Comprehensive Cancer Center.
See Dr. Green's publications in PubMed.
Role of MDia1 in the pathogenesis of del(5q) myelodysplastic syndromes
Our lab is interested in how cytoskeletal signaling, motor proteins and adhesion systems are integrated with chemical signaling pathways to regulate cell behavior and tissue differentiation and disease. The Ji lab studies small G proteins and downstream actin regulatory effectors that participate in enucleation during red cell development.
At the level of the nucleus, the Ji laboratory studies genes involved in erythroid lineage commitment, chromatin condensation and enucleation towards understanding how congenital red cell disorders and leukemia develop.
For more information, visit the faculty profile of Peng Ji, MD, PhD.
See Dr. Ji's publications in PubMed.
Regulation of Motor Neuron and Dopaminergic Neuron Function in Development and Disease
Postdoctoral fellow jobs and graduate student rotation projects are available.
Research DescriptionSpinal Motor Neurons and Spinal Muscular Atrophy (SMA)
SMA is characterized by the selective degeneration of spinal motor neurons. As the leading genetic cause of infant mortality, SMA affects one in every eight thousand live births. Our group is interested in studying mechanism regulating motor neuron development and function, as well as why motor neurons specifically degenerate in SMA. To address these questions, we use a combination of genetic, biochemical and cell biological approaches and utilize genetically modified mice, induced pluripotent stem (iPS) cells reprogrammed from fibroblasts and zebrafish as model systems. We focus on the regulation of mitochondrial functions in SMA pathogenesis. Based on our findings, we hope to develop new therapeutic strategies for treating SMA.
Dopaminergic Neurons and Parkinson's Disease
Dopaminergic neurons located in the ventral midbrain control movement, emotional behavior and reward mechanisms. Dysfunction of these neurons is implicated in Parkinson’s disease, drug addiction, depression and schizophrenia. Our group is interested in the genetic and epigenetic mechanisms regulating dopaminergic neuron functions in disease and aging conditions. We are particularly interested in how aging and mitochondrial oxidative stress contribute to dopaminergic neuron degeneration in Parkinson's disease through transcriptional and epigenetic regulations. We use mouse models, cultured neurons and iPS cells for these studies.
View Dr. Ma's publications at PubMed
Nimrod Miller, PhD, Postdoctoral Fellow
Han Shi, Graduate Student
Brittany Edens, Graduate Student
Kevin Park, Graduate Student
Monica Yang, Undergraduate Student
Aaron Zelikovich, Undergraduate Student
Our goal is to understand the integration of signaling and cytoskeletal dynamics on diverse developmental processes including centriole amplification, cell migration and cell polarity.
Centrioles are microtubule based structures with nine fold symmetry that are involved in both centrosome organization and aster formation during cell division. During the normal cell cycle centrioles duplicate once, generating a mother/daughter pair and in most post-mitotic vertebrate cells the mother centriole then goes on to form the basal body of a sensory cilium. Abnormalities in the duplication of centrioles (and centrosomes) are prevalent in many cancers suggesting a link between centriole duplication and cancer progression. We study what factors limit centriole duplication from a novel direction with the use of Xenopus motile ciliated cells. Ciliated cells are unique among vertebrate cells in that they generate hundreds of centrioles (basal bodies) therefore providing a great system for studying the regulation of centriole duplication. Understanding how nature has overcome the typically tight regulation of centriole duplication will lend insight into the molecular mechanisms of cancer progression.
Tissue development and homeostasis requires dramatic remodeling as new cells migrate into an epithelium. How migrating cells breakdown junctional barriers during development or during diseases processes such as metastasis is poorly understood at the molecular level. During the early development of Xenopus embryos, distinct cell types join the outer epithelium in a process called radial intercalation. We are interested in the molecular mechanisms that regulate both the migration of these cells as well as the tissue remodeling that occurs to accommodate them.
The ability of ciliated epithelia to generate directed fluid flow is an important aspect of diverse developmental and physiological processes including proper respiratory function. To achieve directed flow, ciliated cells must generate 100-200 cilia that are polarized along a common axis both within and between cells. My lab is currently working towards understanding the molecular mechanisms for how cell polarity is coordinated as well as how individual cilia interpret the cells polarity. We have determined that ciliated cells receive polarity cues via the non-canonical Wnt/Planar Cell Polarity (PCP) pathway, but the details of this are still poorly understood. Additionally, the PCP pathway is known to influence a cells cytoskeleton dynamics and a main goal is to understand how this influences the ability of individual cilia to coordinate their polarity.
See Dr. Mitchell's publications on PubMed.
Contact Dr. Mitchell at 312-503-9251.
Focusing on the emigration of leukocytes across vascular endothelial cells in the process of inflammation
Most diseases are due to or involve a significant component of inflammation. My lab studies the inflammatory response at the cellular and molecular level. We are focused on the process of diapedesis, the "point of no return" in inflammation where leukocytes squeeze between tightly apposed endothelial cells to enter the site of inflammation. We have identified and cloned several molecules that are critical to the process of diapedesis (PECAM (CD31), CD99, and VE-cadherin) and are studying how they regulate the inflammatory response using in vitro and in vivo models. We have recently described the Lateral Border Recycling Compartment, a novel para-junctional organelle that contains PECAM and CD99 and is critical for diapedesis to occur. We are currently investigating how this compartment regulates diapedesis in the hope of finding novel and highly specific targets for anti-inflammatory therapy.
The “holy grail” of therapy is to develop selective anti-inflammatory agents that block pathologic inflammation without interfering with the body’s ability to fight off infections or heal wounds. By understanding how endothelial cells at the site of inflammation regulate leukocyte diapedesis, we are hoping to do just that. We have identified several molecules critical for diapedesis in acute and chronic inflammatory settings that can be genetically deleted or actively blocked to markedly inhibit clinical symptoms (e.g. in a mouse model of multiple sclerosis) and tissue damage (e.g. in a mouse model of myocardial infarction) without impairing the normal growth, development, and health of these mice. Our inflammatory models include atherosclerosis, myocardial infarction, ischemia/reperfusion injury, stroke, dermatitis, multiple sclerosis, peritonitis, and rheumatoid arthritis. We are also using 4-dimensional intravital microscopy to view the inflammatory response in real time in living animals.
- What are the molecular mechanisms and signaling pathways that endothelial cells use to regulate the inflammatory response?
- How can we therapeutically treat inflammatory diseases without compromising the ability of the immune system to respond to new threats?
- Do circulating tumor cells use the same mechanisms as leukocytes to cross blood vessels when they metastasize?
We have a high-resolution Perkin Elmer ULTRAVIEW Vox System spinning disk laser confocal microscope in the upright configuration on an Olympus BX51WI fixed stage in my laboratory designed for intravital microscopy. We can image the ongoing inflammatory response and response to our drugs in real time in anesthetized mice with unprecedented temporal and spatial resolutions. We presently image inflammation in the cremaster muscle, intestine, and brain.
Of interest to History of Science buffs, we have the original Zeiss Ultrafot II microscope used to film the first movies of neutrophils ingesting bacteria. As you might expect from something built by Zeiss in the first half of the 20th century, the optics are still fantastic and we use it in our daily work.
Recently we made two major discoveries in endothelial cell inflammatory signaling: Identification of TRPC6 as the cation channel responsible for the endothelial cell calcium flux required for transmigration and description of the CD99 signaling pathway. Both had eluded discovery for decades.
- Watson, R.L., J. Buck, L.R. Levin, R.C. Winger, J. Wang, H. Arase, and W.A. Muller. 2015. Endothelial CD99 signals through soluble adenylyl cyclase and PKA to regulate leukocyte transendothelial migration. J. Exp. Med. 212:1021-1041.
- Weber, E.W., F. Han, M. Tauseef, L. Birnbaumer, D. Mehta, and W.A. Muller. 2015. TRPC6 is the endothelial calcium channel that regulates leukocyte transendothelial migration during the inflammatory response. J Exp Med 212:1883-1899. PMID: 26392222
- AAAS Fellow, elected 2010
- Rous-Whipple Award, American Society for Investigative Pathology, 2013
- Ramzi Cotran Memorial Lecture, Brigham and Women’s Hospital, 2014
- Karl Landsteiner Lecture, Sanquin Research Center, Amsterdam, Netherlands, 2016
- Member, Faculty of 1000 Leukocyte Development Section
- American Society for Investigative Pathology (ASIP) Council
- ASIP Research and Science Policy Committee Chair
- North American Vascular Biology Organization (NAVBO) Secretary-Treasurer
NIH R01 HL046849-26 William A. Muller 08/01/91 – 05/31/20
The Roles of Endothelial PECAM and the LBRC in Leukocyte Transmigration
This study investigates how PECAM-1 and the LBRC regulate transmigration. We will investigate how PECAM ligation on endothelial cells activates TRPC6 to promote the calcium flux necessary for transmigration (Aim I). We will identify how endothelial IQGAP1 regulates transmigration by regulating targeted recycling of the LBRC (Aim II). We will identify how kinesin light chain 1 variant 1 facilitates movement of the LBRC during targeted recycling (Aim III). All of these Aims include mechanistic studies in vitro and validation studies in vivo using mouse models of ischemia/reperfusion injury in acute inflammation and myocardial infarction.
NIH R01 HL064774-16 William A. Muller 04/01/00 – 08/31/20
Beyond PECAM: Mechanisms of Transendothelial Migration
This study investigates the role of PECAM, CD99L2, and CD99 in transendothelial migration. Aim I will test the hypothesis that leukocytes control the molecular order of transmigration by polarizing PECAM on their leading edge and CD99 on the trailing edge during transmigration. Aim II will identify the signaling mechanisms by which CD99L2 regulates transmigration. Aim III will identify the signaling mechanisms by which CD99 regulates targeted recycling of the LBRC and transmigration downstream of Protein Kinase A. All Aims have in vitro mechanistic studies and in vivo validation studies using intravital microscopy in the cremaster muscle circulation and a murine model of ischemia/reperfusion injury in myocardial infarction.
For more information, visit the faculty profile of William A Muller, MD, PhD
View Dr. Muller's publications at PubMed
Research Assistant Professors
- David Sullivan, PhD email@example.com
- Annette Gonzalez, PhD firstname.lastname@example.org
- Tao Fu, PhD email@example.com
- Ayush Batra, MD firstname.lastname@example.org
- Neil Nadkarni, MD email@example.com
- Prarthana Dalal (MD/PhD) PrarthanaDalal@u.northwestern.edu
- Nakisha Rutledge Rutledge2012@u.northwestern.edu
- Margarette Clevenger MargaretteClevenger2021@u.northwestern.edu
- Clifford Carpenter, PhD firstname.lastname@example.org
Office: Ward Building, Room 3-126
303 East Chicago Avenue
Chicago, IL 60611-3008
Phone: (312) 503-0436
Fax: (312) 503-8249
Lab: Ward Building 3-070 and 3-031
Lab Phone: (312) 503-5200
Lab Fax: (312) 503-2630
Microtubule regulation and function during infection by Human Immunodeficiency Virus (HIV)
Our research focuses on infection by Human Immunodeficiency Virus type 1 (HIV-1), a retrovirus and causative agent of acquired immunodeficiency syndrome (AIDS). In addition to suppressing the immune system, rendering victims susceptible to opportunistic infections, HIV-1 can cross the blood-brain barrier and cause serious damage to the central nervous system, ultimately leading to HIV-associated dementia.
We are interested in how HIV-1 particles move within infected cells, including brain cell types such as microglia. Our work focuses on how the virus exploits host microtubules, the intracellular filaments that mediate cargo trafficking to different subcellular sites within the cell.
Our earlier work, employing a variety of screening approaches, identified a number of host proteins involved in cytoskeletal regulation and motor function as playing key roles in the early stages of HIV-1 infection. This includes Ezrin-Radixin-Moesin (ERM) proteins, which cross-link the actin and microtubule cytoskeletons. In exploring their role in HIV-1 infection, we identified the first biological function for the host protein, PDZD8, demonstrating that it binds ERMs to control microtubule stability. Furthermore, we uncovered that PDZD8 is a direct target for the HIV-1 protein, Gag.
Other work in our laboratory has shown that HIV-1 can induce the formation of highly stable microtubule subsets to facilitate early HIV-1 trafficking to the nucleus. We are interested in the role played in this process by proteins such as PDZD8, as well as a family of specialized microtubule regulatory proteins called +TIPs, which accumulate at the ends of dynamically growing microtubule filaments to control their growth and stability. We are also interested in the function of microtubule motors and cargo adaptor proteins in HIV-1 infection. In particular, we are exploring how Fasciculation and Elongation factor Zeta-1 (FEZ-1), a kinesin-1 adaptor protein that is highly expressed in neurons, functions to control HIV-1 infection. Our work employs a range of approaches, including biochemical characterization of protein-protein interactions as well as live imaging of fluorescently-labeled HIV-1 particles as they move within infected cells.
The ultimate goal of our work is to understand the molecular basis behind how microtubules, regulators of microtubule dynamics and microtubule motor proteins function to enable HIV-1 movement to and from the nucleus.
See Dr. Naghavi's publications at PubMed.
Contact Dr. Naghavi at 312-503-4294.
The Ridge Lab investigates the role of intermediate filaments in lung pathophysiology
Vimentin is also involved in all stages of cancer development, from PI3K/AKT and Erk pathway regulation in tumerigenesis, to its defining role in epithelial-to-mesenchymal transition, to metastatic cell invasion and migration, making it an intriguing therapeutic target. Our purpose in examining vimentin’s role in lung cancer is to determine whether its inhibition might be of benefit to patients.
View our lab’s publications in PubMed.
To learn more, please visit the faculty profile pages of Karen M. Ridge, PhD
Visit the Ridge Lab Website
Email Dr. Ridge
Phone 312-503-1648 or the Ridge Lab at 312-503-0403
Dale Shumaker, PhD
Research Assistant Professor
Research Technologist 1
Signal Transduction In Fibrogenesis
Our laboratory examines the signals that modulate fibrogenesis. This process is important in promoting normal healing but, when uncontrolled, leads to excessive scar formation such as occurs in chronic progressive cardiovascular or kidney disease. Our studies center upon the role of the Smad signal transduction pathway in extracellular matrix accumulation. We are investigating the mechanism(s) by which transforming growth factor (TGF)-ß stimulates collagen accumulation by the human kidney mesangial cells that are central to the scarring of the renal filter in disease states.
We have determined that the TGF-ß-specific Smad pathway is modulated by interaction with multiple additional signaling mechanisms, including those related to ERK MAP kinase, phosphatidyl inositol-3-kinase, protein kinase C and cytoskeletal rearrangement. Cross-talk amongst these pathways provides a complex milieu for the cellular regulation of fibrogenesis. Characterizing the precise patterns of interaction among signaling pathways that are usually studied in isolation offers our lab the opportunity to define unique events that determine tissue specificity.
Presently, we have two major projects in the lab. In one, we are examining the role of Smad anchor for receptor activation (SARA) in regulating cell phenotype and function. In the other, we are examining how cell interaction with the extracellular matrix leads to the activation of specific signaling pathways that promote fibrogenesis. We recently reported that integrin-mediated, cell adhesion-dependent activation of focal adhesion kinase (FAK) plays an essential role in specific phosphorylations of the Smad3 molecule and in TGF-ß-stimulated collagen expression.
View Dr. Schnaper's publications at PubMed
Development and regenerative repair of vertebrate limbs and hearts
The development of organs during embryogenesis and their repair during adulthood are biological problems of very practical importance for regenerative medicine.
Using both newt and zebrafish model organisms that naturally rebuild lost structures as adults, we identified evolutionarily conserved gene activities indicative of a molecular signature of regeneration. Particularly, we found the dynamic remodeling of the extracellular matrix (ECM) to be key in instructing cell behaviors that are critical for initiating and maintaining regenerative processes. These findings point to new opportunities for the enhancement of regenerative wound healing in mammals through the manipulation of the local extracellular environment.
As a new research direction, we are studying an unexpected hyperactive blood clotting phenotype in mice deficient for the actin-associated protein Pdlim7. The Pdlim7 knockout mouse provides strong translational opportunities as a novel model to better understand the causes and possible treatments of hypercoagulopathies.
For more information visit the faculty profile of Hans-Georg Simon, PhD.
View all publications on PubMed
Phone Dr. Simon at 773-755-6391 or the Simon Lab at 773-755-6372.
Cell and molecular biology of herpesvirus invasion of the nervous system
We investigate the relationship between infection of the nervous system by herpesviruses and disease outcome. Some of the most traumatic diseases – including polio, rabies and encephalitis – result from infections of the nervous system. In contrast, herpesviruses are highly proficient at infecting the nervous system, yet normally do not cause neurological disease. This is achieved in part by self-imposed restrictions encoded within the viruses that limit viral reproduction and prevent dissemination into the brain. For the individual, this results in a relatively benign infection, yet the virus becomes a life-long occupant of the nervous system that will periodically reemerge at body surfaces to infect others. Unfortunately, this infectious cycle can go awry resulting in several forms of severe disease (i.e. keratitis and encephalitis).
We have pioneered methods to genetically manipulate herpesviruses and visualize individual viruses in living neurons. Using these methods, we are studying the mechanisms by which the virus achieves its stringently controlled infectious cycle. Current genetic manipulations are based on a full-length infectious clone of the herpesvirus genome. The clone was made as a bacterial artificial chromosome (BAC) in E. coli. Transfection of purified E. coli BAC plasmid into permissive eukaryotic cells is sufficient to initiate viral infection, allowing for immediate examination of viral mutant phenotypes in a variety of biological assays. For example, by fusing the green fluorescent protein (GFP) to a structural component of the viral capsid, individual viral particles can be tracked within the axons of living neurons during both entry and egress phases of the infectious cycle. Studies in culture can be complemented by examining the pathogenesis of mutant viruses in rodent models of infection.
Using these methods, we have discovered key aspects of cellular infection, viral assembly and intracellular transport. Looking forward, we are continuing to pursue our multidisciplinary approach of combining neuroscience, cell biology, bacterial genetics and virology to better understand these important pathogens.
For lab information and more, see Dr. Smith's faculty profile.
See Dr. Smith's publications on PubMed.
Contact Dr. Smith at 312-503-3745 or the lab at 312-503-3744.
Contributions of immune cell-mediated inflammation to development and progression of colorectal cancers
Immune cells are critical for host defense, however immune cell infiltration of mucosal surfaces under the conditions of inflammation leads to significant alteration of the tissue homeostasis. This includes restructuring of the extracellular matrix and alterations in cell-to-cell adhesions. Particularly, immune cell-mediated disruption of junctional adhesion complexes, which otherwise regulate epithelial cell polarity, migration, proliferation and differentiation can facilitate both tumorigenesis and cancer metastasis. Our research thus focuses on understanding the mechanisms governing leukocyte induced tissue injury and disruption of epithelial integrity as potential risk factors for tumor formation, growth and tissue dissemination.
Ronen Sumagin, PhD
Assistant Professor in Pathology
The Thorp laboratory studies how immune cells coordinate tissue repair and regeneration under low oxygen, such as after a heart attack.
The Edward Thorp Lab studies the crosstalk between immune cells and the cardiovascular system and, in particular, within tissues characterized by low oxygen tension or associated with dyslipidemia, such as during myocardial infarction. In vivo, the lab interrogates the function of innate immune cell phagocytes, including macrophages, as they interact with other resident parenchymal cells during tissue repair and regeneration. Within the phagocyte, the influence of hypoxia and inflammation on intercellular and intracellular signaling networks and phagocyte function are studied in molecular detail. Taken together, our approach seeks to discover and link basic molecular and physiological networks that causally regulate disease progression and in turn are amenable to strategies for the amelioration of cardiovascular disease.
View Dr. Thorp's publications at PubMed
Contact the Thorp lab at 312-503-3140.
Xin-Yi Yeap, MS
Lab Manager and Microsurgery
Investigating the mechanisms of adherens junctions assembly, dynamics and signaling.
The Troyanovsky lab’s research focuses on cadherin, intercellular adhesion and signaling. Classic cadherins are critical proteins mediating cell-cell adhesion and various signaling pathways responsible for cellular proliferation, differentiation and morphogenesis. Abnormalities in this system are causal factors in many pathologies, including cancer. The molecular mechanisms of cadherin-based adhesion, however, are largely unknown. How do cadherins establish the adhesion contact? How do they interact with the cytoskeleton? What are the signaling pathways they control? Our laboratory's work is centered around these questions. We are currently working on the following specific projects:
- An individual cadherin molecule’s adhesion site is very weak. To mediate tight adhesion, cadherin molecules form clusters. Recently our lab showed that cadherin clustering is based on two different mechanisms. First, using an extracellular cis-binding site, cadherin sticks laterally in small groups. Additional clustering is promoted by the actin cytoskeleton, binding to which limits cadherin diffusion. The aim of our current study is to understand the regulation of cadherin clustering through modulation of the cadherin-actin filament coupling.
- The formation of cadherin adhesive clusters interconnected to the cytoskeleton is not sufficient to establish functional intercellular junctions. The junctions stimulate formation of actin bundles that is required for epithelial cells to organize their actin cytoskeleton. How adherens junctions initiate actin bundle formation is another direction in our research.
- Cadherin is not the only transmembrane protein in adherens junctions. These structures contain adhesion proteins from the nectin family as well as numerous signaling proteins. We showed that one of such proteins, gamma-secretase, interacts with E-cadherin through p120-catenin. The roles of nectins and gamma-secretase and the ways they are recruited into adherens junctions are also areas of focus in our lab.
For more information see Sergey Troyanovsky’s, PhD, faculty profile.
View Dr. Troyanovsky's publications at PubMed.
Phone the Troyanovsky Lab at 312-503-9275
Chromosome segregation, genomic instability and cancer biogenesis
The broad area of our research interest is in the cytoskeleton and intracellular motility. The cytoskeletal polymer that we are most interested in is the microtubules and the cytoskeletal process that we are most excited about is the accurate segregation of chromosomes during mitosis. A dividing cell assembles mitotic kinetochores and a mitotic spindle at the onset of mitosis. The kinetochores serve as sites where the microtubules of the mitotic spindle comes in physical contact with the chromosomes and are hence extremely important for accurate chromosome segregation. Improper kinetochore microtubule (kMT) attachments lead to erroneous chromosome segregation, chromosome loss and aneuploidy in turn, which is the leading cause of cancer in tissue cells and of birth defects and miscarriages during human embryonic development.
Over a decade of research had identified the kinetochore-bound Ndc80 complex as the key requirement for the direct physical contact with microtubules of the spindle. But what is still not understood well is how the kinetochores and the Ndc80 complex remains stably attached to the highly dynamic microtubule plus-ends during mitotic metaphase and subsequent chromosome segregation in anaphase. Work is yeast model system had provided us with important insights into the possible mechanism governing this process, but we still do not have a clear mechanistic picture in vertebrate systems. Work in our lab focusses on understanding the molecular mechanisms that are involved the controlling and regulating kinetochore microtubule attachments in vertebrate cells. We are also very interested to delineate the intricate mechanism that link this event with the activation and silencing of the spindle assembly checkpoint which is also absolutely critical for accurate chromosome segregation
See Dr. Varma's publications on PubMed.
Contact Dr. Varma at 312-503-4318 or the lab at 312-503-0824.
Mechanisms of poxvirus and herpesvirus infection; translational control of gene expression; virus trafficking
Research in our laboratory focuses on two aspects of DNA virus biology:
1) The role of the host translation system during infection by poxviruses. Members of the poxvirus family include Variola Virus (VarV), the causative agent of smallpox, and Vaccinia Virus (VacV), a close relative that was used as a vaccine against smallpox and which has become the laboratory prototype for poxvirus research. These large double-stranded DNA viruses exhibit an impressive level of self-sufficiency and encode many of the proteins required for transcription and replication of their DNA genomes. Indeed, unlike many other DNA viruses, poxviruses do not require access to the host nucleus and replicate exclusively in the cytoplasm of infected cells within compartments termed “viral factories”. However, like all viruses, they remain dependent on gaining access to host ribosomes in order to translate their mRNAs into proteins and must also counteract host antiviral responses aimed at crippling the translation system to prevent virus replication.
Our work focuses on the function of two eukaryotic translation initiation factor (eIF) complexes, eIF3 and eIF4F, that regulate ribosome recruitment to capped mRNAs and their role in VacV infection. We have found that VacV stimulates the assembly of eIF4F complexes and that this is important for both viral protein synthesis and control of host immune responses. Furthermore, we have found that eIF3 functionally communicates with eIF4F during translation initiation and that this plays an important role in VacV replication. We have also found that VacV redistributes key eIF4F subunits to specific regions within viral factories, a process that appears to involve the viral I3 protein.
We are currently exploring the compartmentalized replication of VacV as a means to better understand fundamental mechanisms of localized translational control and how this functions to regulate viral protein synthesis and host antiviral responses. We are also studying how the virus controls eIF4F activity by targeting upstream signaling pathways, with a particular emphasis on the metabolic sensor mammalian target of rapamycin (mTOR).
2) Microtubule regulation and function during herpes simplex virus infection. We are also interested in how herpes simplex virus type 1 (HSV-1) exploits host signaling pathways and specialized microtubule regulatory proteins, called +TIPs, to facilitate virus movement within the cell at various stages of the viral lifecycle.
See publications on PubMed.
Contact Dr. Walsh at 312-503-4292
Technical StaffHelen Astar
Molecular Mechanisms of Tumorigenesis and Cancer Metastasis
The Zhang laboratory is focused on two research directions: 1) determining role of tumor suppressors in development and cancer progression and 2) identifying immune components that control breast cancer metastasis.
The main focus of my research program is to study the roles of tumor suppressors in normal development and in breast and prostate cancer progression, focusing on maspin and an Ets transcription factor PDEF. Maspin is a unique member of the SERPIN family that plays roles in normal tissue development, tumor metastasis and angiogenesis. Genetic studies by my laboratory using maspin transgenic and knockout mice demonstrated an important role of maspin in normal mammary, prostate and embryonic development. Recently, we have identified several new properties of maspin. As a protein that is present on cell surface, maspin controls cell-ECM adhesion. This function is responsible for maspin-mediated suppression of tumor cell motility and invasion. We have also discovered that maspin is involved in the induction of tumor cell apoptosis through a mitochondrial death pathway. The long-term goals of these projects are to elucidate the molecular mechanisms by which maspin and PDEF control tumor metastasis and to identify their physiological functions in development. These analyses are not only important for basic biology and but also may lead to a therapy for cancer and other developmental diseases.
Another focus of research in Zhang lab is to identify immune components that control breast cancer metastasis. Chronic inflammation not only increases neoplastic transformation but also drives the inhibition of the immune response in a protective negative-feedback mechanism. Suppressive immune cells are recruited to the sites of inflammation and function to inhibit both innate and adaptive immune responses, enabling tumor tolerance and unmitigated tumor progression. To study the interplay between tumor and immune cells, the Zhang lab has developed a unique animal model of breast cancer that reproduces different stages of breast cancer bone metastasis. Molecules that control tumor-immune cell interaction and immunosuppression have been identified. We are currently studying roles of these genes in tumor-driven evolution that control chronic inflammation and immunosuppression. We hypothesize that these key pro-inflammatory genes are upregulated during cancer progression, which function synergistically to recruit and activate suppressive MDSCs, TAMs and Tregs, inducing chronic inflammation and an immunosuppressive tumor microenvironment conducive to metastatic progression.
For more information visit Ming Zhang's faculty profile.
View publications by Ming Zhang in PubMed
Hearing and cochlear amplification, deafness-related proteins and cell death
Left: Three rows of outer hair cells showing prestin proteins (green). Right: location of marshalin (green) in the organ of Corti, the mammalian hearing organ. Microtubule bundles (red) are stained with anti-a-tubulin.
The goal of my lab is to identify and investigate molecules that play important roles in mammalian hearing, thus enriching our understanding of cochlear physiology and further developing a better strategy to prevent hearing loss. Deafness is commonly caused by defects in inner ear hair cells. In mammalian cochleae, inner hair cells (IHCs) function as sensory receptors conveying sound-related information to the central nervous system. Outer hair cells (OHCs) amplify the mechanical signals delivered to IHCs. The cooperation between IHCs and OHCs results in sensitive hearing and sharp tuning. Complex and sophisticated protein networks in hair cells facilitate their functions. Very often, genetic defects in a single protein can interfere with the entire network and cause deafness. Our research has been centered on several important proteins expressed in cochlea.
1. Molecular basis of cochlear amplification. OHCs undergo rapid somatic length changes when the voltage across their membrane is altered. This unique somatic electromotility provides the local mechanical amplification of the cochlear response to sound. Without OHCs, hearing threshold is elevated by 40-50 dB and frequency resolution deteriorates. Prestin is the motor protein of OHCs and is required for cochlear amplification (Zheng et al., Nature, 2000). Coincidently, prestin is only expressed in OHCs, which are also the most vulnerable cells in the organ of Corti. In the past, studying OHC amplification mechanisms and preventing OHC loss were considered two separate research fields. However, our recent data indicate a close connection between prestin's function and the vulnerability of OHCs to a variety of ototoxic exposures. To understand this link, we focus on investigating the molecular mechanism of the motor protein prestin using various cellular, biochemical and molecular biological methods.
2. Protein network of hair cells. We are focus on several deafness-related proteins: CDH23, CEACAM16 and Marshalin. Cadherin 23 is a tip-link protein of hair cells. CEACAM16 is an adhesive protein localized at the tectorial membrane (Zheng et al. PNAS, 2011). Marshalin is another newly identified microtubule minus-end binding protein that is expressed in the inner ear. Its expression is developmentally controlled (Zheng et al., Biology Open 2013). Very often, genetic defects in a single protein can interfere with the entire network and cause deafness. We are in the process of investigating interactions among these proteins and their physiological roles for normal hearing and deafness.
For more information, visit the faculty profile of Jing Zheng, PhD.
View Dr. Zheng's publications in PubMed