Stroke’s long-term effects on blood-spinal cord barrier can lead to ‘an increasingly toxic environment’ in spinal cord and ‘significant input on disease pathology’

Tampa, Fla. (June 14, 2016) – A team of researchers at the University of South Florida investigating the short and long-term effects of ischemic stroke in a rodent model has found that stroke can cause long-term damage to the blood-spinal cord barrier (BSCB), creating a “toxic environment” in the spinal cord that might leave stroke survivors susceptible to motor dysfunction and disease pathology.

The paper describing their study was recently published online and will appear in an upcoming issue of Journal of Neuropathology and Experimental Neurology.

“This study, carried out using laboratory rats modeling stroke, demonstrated that ischemic stroke — in both its subacute and chronic stages — damages the BSCB in a variety of ways, creating a toxic environment in the spinal cord that can lead to further disability and exacerbate disease pathology,” said study lead author Svitlana Garbuzova-Davis, PhD, associate professor in USF’s Center of Excellence for Aging and Brain Repair, Department of Neurosurgery and Brain Repair. “The aim of our study was to evaluate post-stroke BSCB condition that might lead to the development of more effective therapies for stroke survivors.”

Svitlana Garbuzova-Davis, PhD

The BSCB provides a specialized protective ‘microenvironment’ for neural cells in the spinal cord. Substantial vascular damage is a major pathologic feature of both subacute and chronic stroke caused by an extended period of microvascular permeability after the BSCB loses integrity. Damage to the BSCB, explained the researchers, plays a fundamental role in the development of several pathological conditions, including abnormal motor function.

The researchers, who evaluated the BSCB in test animals at seven and 30 days after stroke modeling, found that ischemic stroke damaged the gray and white matter in the cervical spinal cord on both sides of the spinal column, based on analysis of electron microscope images. Among the effects were damage to neural cells called ‘astrocytes,’ loss of motor neurons, reduced integrity of a tight junction protein between barrier cells, and swollen axons with damaged myelin in ascending and descending tracts connecting to the brain.

They also found stroke-associated ‘upregulation’ of Beclin-1 in endothelial cells composing the BSCB. Beclin-1, explained the researchers, helps induce autophagy, an activity associated with removal of various intracellular components. They also observed a decrease in LC3B, an essential autophagy protein, at a later stage post-stroke. These observations of Beclin-1 and LC3B suggest an impaired post-stroke autophagy process in spinal cord capillaries, inducing endothelial cell degeneration.

These stroke-related alterations in the cervical spinal cord indicate pervasive and long-lasting BSCB damage that would severely affect spinal cord function, wrote the researchers, adding that the widespread microvascular impairment in the gray and white matter of the cervical spinal cord aggravated motor neuron deterioration and had the potential to cause motor dysfunction.

“Because our investigations on the post-stroke microvascular alterations, including BSCB damage, have just begun, many questions remain,” said senior author Cesario Borlongan, PhD, professor and director of the USF Center of Excellence for Aging and Brain Repair. “Specifically, the protein expression responsible for endothelial cell degeneration and tight junction damage we identified in this study needs to be confirmed through further tests. Also, behavioral tests of motor function in post-stroke animals in correlation with BSCB damage are needed. These questions and others will be addressed in our future studies.”

Paul R. Sanberg, PhD, DSc, Distinguished University Professor, a co-author of the paper, concluded that “these novel data showing BSCB damage in subacute and chronic ischemic stroke may lead to development of new therapeutic approaches for patients with ischemic cerebral infarction.”

Article citation:
Blood-Spinal Cord Barrier Alterations in Subacute and Chronic Stages of a Rat Model of Focal Cerebral Ischemia. Svitlana Garbuzova-Davis; Edward Haller; Naoki Tajiri; Avery Thomson; Jennifer Barretta; Stephanie N. Williams; Eithan D. Haim; Hua Qin; Aric Frisina-Deyo; Jerry V. Abraham; Paul R. Sanberg; Harry Van Loveren; Cesario V. Borlongan. Journal of Neuropathology & Experimental Neurology 2016; doi: 10.1093/jnen/nlw040.

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– News release by Randy Fillmore, USF Communications and Marketing

A USF preclinical study shows transplanted human bone marrow stem cells preferentially migrate to the spleen, reducing systemic inflammation of later-stage stroke

Tampa, FL (Sept. 15, 2015) — Stroke injures the brain, but a new University of South Florida study indicates an abdominal organ that plays a vital role in immune function, the spleen, may be a target for treating stroke-induced chronic inflammation leading to further brain cell death.

Neuroscientists at the USF Center of Excellence for Aging and Brain Repair found that human bone marrow stem cells intravenously administered to post-stroke rats preferentially migrated to the spleen and reduced the inflammatory-plagued secondary cell death associated with stroke progression in the brain. The study is reported in the September 2015 issue of the American Heart Association journal Stroke.

Cesario Borlongan, PhD, the study’s principal investigator, is a pioneer in stem cell therapy research for stroke. He directs the USF Center of Excellence for Aging and Brain Repair.

The USF study helps resolve a perplexing observation by many scientists evaluating the effects of stem cell therapies: Functional recovery occurs in experimental models of neurological disorders, including stroke, despite little or mediocre survival of transplanted stem cells within the injured brain.

“Our findings suggest that even if stem cells do not enter the brain or survive there, as long as the transplanted cells survive in the spleen the anti-inflammatory effects they promote may be sufficient enough to therapeutically benefit the stroke brain,” said principal investigator Cesario Borlongan, PhD, professor and director of the USF Center of Excellence for Aging and Brain Repair.

Stroke is a leading cause of death and the number one cause of chronic disability in the United States, yet treatment options are limited.  Stem cell therapy has emerged as a potential treatment for ischemic stroke, but most preclinical studies have looked at the effects of stem cells transplanted during acute stroke – one hour to 3 days after stroke onset.

Following acute stroke, an initial brain attack caused by lack of blood flow, the blood-brain barrier is breeched, allowing the infiltration of inflammatory molecules that trigger secondary brain cell death in the weeks and months that follow. This acerbated inflammation is the hallmark of chronic stroke.

The USF researchers intravenously administered human bone marrow stem cells to rats 60 days following stroke onset – the chronic stage. The transplanted stem cells were attracted predominantly to the spleen; the researchers found 30-fold more stem cells survived in this peripheral organ than in the brain.  Once in the spleen, the stem cells dampened an inflammatory signal (tumor necrosis factor) activated immediately after stroke and prevented the migration from spleen to the compromised brain of harmful macrophages that stimulate inflammation.

This reduced systemic inflammation correlated with significant decreases in the size of lesions caused by acute stroke in the striatum—a portion of the brain controlling movement. There was a trend toward prevention of additional neuron loss in the portion of the brain affecting memory and thinking.

“In the chronic stage of stroke, macrophages are like fuel to the fire of inflammation,” Dr. Borlongan said. “So if we can find a way to effectively block the fuel with stem cells, then we may prevent the spread of damage in the brain and ameliorate the disabling symptoms many stroke patients live with.”

The USF researchers next plan to test whether transplanting human bone marrow stem cells directly into the spleen will lead to behavioral recovery in post-stroke rats.

Dr. Borlongan with postdoctoral fellow Sandra Acosta, PhD, the study’s lead author.

The one drug approved for emergency treatment of stroke, the clot-busting drug tPA, must be administered less than 4.5 hours after onset of ischemic stroke, and  benefits only 3 to 4 percent of patients, Dr. Borlongan said. While more study is needed, evidence from USF and other groups thus far indicates stem cells may help provide a more effective treatment for stroke over a wider timeframe.

“Stem cells are not a magic bullet, but a combination of stem cells and other anti-inflammatory agents may lead to the optimal therapeutic benefit for stroke patients,” he said.

Lead study author Sandra Acosta, PhD, a postdoctoral fellow in the USF Department of Neurosurgery and Brain Repair, said targeting the spleen with stem cells or the anti-inflammatory molecules they secrete offers hope for treating chronic neurodegenerative diseases like stroke at later stages.

“We’ve shown (in an animal model) that it’s possible to stop disease progression 60 days after the initial stroke injury, when chronic inflammation in the brain was widespread,” she said. “If that can be replicated in humans, it will be powerful.”

The USF study was supported by grants from the National Institute of Neurological Disorders and Stroke and the James and Esther King Biomedical Research Foundation.

Article citation:
Sandra A. Acosta; Naoki Tajira; Jaclyn Hoover; Yuji Kaneko; and Cesar Borlongan, “Intravenous Bone Marrow Stem Cell Grafts Preferentially Migrate to Spleen and Abrogate Chronic Inflammation in Stroke,” Stroke, September 2015; DOI: 10.1161/STROKEAHA.115.009854.

                                                                                                                                                  About USF Health
USF Health’s mission is to envision and implement the future of health. It is the partnership of the USF Health Morsani College of Medicine, the College of Nursing, the College of Public Health, the College of Pharmacy, the School of Physical Therapy and Rehabilitation Sciences, and the USF Physician’s Group. The University of South Florida is a Top 50 research university in total research expenditures among both public and private institutions nationwide, according to the National Science Foundation.  For more information, visit www.health.usf.edu

Media contact:
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abaier@health.usf.edu or (813) 974-3303

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//www.youtube.com/watch?v=8Bf9W1POK_4

Distinguished USF Health Professor Cesario Borlongan, PhD, is internationally recognized for translational research on the neuroprotective and neurorestorative effects of stem cell therapies in stroke.

Over the last 22 years, his innovative work in the field of neuroscience has encompassed other neurodegenerative diseases and traumatic brain injury as well as stroke.  Dr. Borlongan, director of the Center of Excellence for Aging and Brain Repair at USF, does not hesitate to take calculated risks when it comes to following a different path of inquiry that may lead to a new discovery.

Take, for example, his recent study — with lead author Sandra Acosta, PhD, a postdoctoral fellow in Dr. Borlongan’s laboratory – published in the September issue of the American Heart Association journal Stroke.  The study showed that human bone marrow stem cells intravenously administered to post-stroke rats migrated to the spleen, an abdominal organ that plays a critical role in immune function, and significantly reduced chronic inflammation in the stroke brain.

“Next we want to explore whether transplanting these cells directly into the spleen, rather than peripherally, can lead to better functional recovery, including central nervous system improvement,” Dr. Borlongan said. “Even though stroke is a brain disorder, it has a major peripheral component – and in this case it may be the spleen that should be monitored more closely in our stroke patients.”

USF neuroscientist Cesario Borlongan, PhD, does not hesitate to take calculated risks when it comes to following a different path of inquiry that may lead to a new discovery.

In another study published in the journal PLOS ONE in 2013, Dr. Borlongan and colleagues suggested a new view of how stem cells may help repair the brain following trauma.   In a series of preclinical experiments they reported that transplanted cells appear to build a “biobridge” that links an uninjured brain site where new neural cells are born with the damaged region of the brain.  Based in part on the data reported by Dr. Borlongan’s group, the U.S. Food and Drug Administration approved a limited clinical trial to transplant SanBio 623 cells (an adult stem cell therapy) in patients with traumatic brain injury.  The trial has begun enrolling patients at Stanford University Medical Center.

Additionally, Dr. Borlongan’s bench to bedside research has led to to five FDA-approved clinical trials of cell transplantation in stroke, including the first cell therapy in adult stroke patients.

“One thing that distinguishes our center at USF from many others is its emphasis on translational research” he said. “We like basic science, but we want to see the discoveries in the petri dish translated to animal models of brain disorders and eventually go into the clinics…  At the end of the day, we ask the question:  Can this science be translated into saving lives and make a difference in the lives of patients with stroke and traumatic brain injury?”

National Institutes of Health (NIH) Scientist Emeritus Barry Hoffer, MD, PhD, says despite Dr. Borlongan’s relative youth as a scientist, his insight and creativity has yielded many discoveries advancing the understanding of ischemic brain injury, blood-brain barrier pathophysiology, traumatic brain injury, and stem cell transplantation.

“If I were to make a list of young neuroscientists who are already superstars, Dr. Borlongan would be at the top of my list,” said Dr. Hoffer, an adjunct professor of neurosurgery and proteomics and genomics at Case Western Reserve University School of Medicine.

Dr. Borlogan with Sandra Acosta, PhD, one of the postdoctoral fellows in his laboratory at the USF Center of Excellence for Aging and Brain Repair. “They are the ones who come up with the paradigm-shifting approaches to the experiments and drive the science,” he says of the trainees and students.

Dr. Borlongan has received continuous federal funding totaling more than $15 million from the U.S. Department of Veterans Affairs, the Department of Defense and the NIH since 2002 and also serves as the principal investigator on several industry grants.  Recently, he was awarded a two-year R21 grant from the National Institute of Neurological Disorders and Stroke to study the effects of endothelial stem cells on inflammation in the stroke vasculome — specific genes expressed on the interior surface of blood vessels in the brain following stroke.  The research may have implications for regulating inflammatory genes to treat chronic stroke.

The 30-member laboratory led by Dr. Borlongan includes graduate and doctoral students, a neurosurgery resident, and postdoctoral fellows – emerging scientists who contribute greatly to the research team’s vibrancy, innovation and passion for scientific discoveries.

“We need these young minds to challenge the existing paradigm. They are the ones who come up with the paradigm-shifting approaches to experiments and drive the science,” Dr. Borlongan said.  “I encourage, help facilitate and direct them to the literature, but it’s their show… I try to stay in the background rather than get in their way. That’s the most valuable thing I learned from my mentors.”

He also lets students know that it’s OK when experiments yield unexpected or negative results, because they can learn and move forward even if the initial hypothesis does not hold up. “Be logical, but follow the data; don’t change its direction,” he said. “It may lead you to something novel.”

Dr. Borlonghan with some of the emerging young scientists in his laboratory. They were recently filmed by LabTV.

Dr. Borlongan received his PhD in physiological psychology in 1994 at Keio University in Tokyo, Japan. He pursued fellowships in neuroscience at USF and the NIH, National Institute on Drug Abuse.  He was an associate professor at Medical College of Georgia, where he directed the Department of Neurology Cell Transplantation, before returning to USF as a faculty member in 2008.

He regularly serves on peer review panels for the NIH, VA and the American Heart Association and is an editorial board member for numerous scientific journals, including Cerebral Blood Flow and Metabolism, Stem Cells, PLOS ONE and Brain Research.  He holds several patents for inventions related to investigational cell therapies for brain disorders.

A fellow of the American Association for the Advancement of Science and member of the USF chapter of the National Academy of Inventors, Dr. Borlongan is 2015-16 president of the American Society for Neural Therapy and Repair.

Photos and video by Sandra Roa,  USF Health Communications and Marketing

Two Morsani College of Medicine faculty members whose work bridges the basic and clinical sciences — David Birk, PhD, and Cesario Borlongan, PhD  — were recently designated as Distinguished USF Health Professors for 2014-15.

The promotion recognizes outstanding faculty who have clearly distinguished themselves in their fields and are known nationally and internationally for their research and scholarly activity.

David Birk, PhD

An international expert in the field of extracellular matrix (ECM) biology and pioneer in electron microscopy, Dr. Birk is a professor in the Department of Molecular Pharmacology and Physiology.  His decades of research and ongoing work with collagens and a family of proteins known as small leucine rich proteoglycans have led to a groundbreaking understanding of the extracellular matrix or framework involved in the development of connective tissue. Dr. Birk’s work on the regulation of ECM assembly has major implications for current and future treatments of connective tissue disorders including poor wound healing and scarring, progressive fibrotic diseases, corneal blindness, and congenital diseases such as Ehlers-Danlos syndrome.

Dr. Birk’s major accomplishments, including success in obtaining National Institutes of Health grants, have made him sought after as a collaborator with well-recognized laboratories.  He is consistently invited to serve on national scientific committees including NIH study sections and the research committees and advisory boards of Shriners Hospitals for Children.

A world leader in stem cell therapy research for stroke and traumatic brain injury, Dr. Borlongan is a professor in the Department of Neurosurgery and Brain Repair and director of the Center for Excellence in Aging and Brain Repair. His translational bench to clinic research has led to five FDA-approved clinical trials of cell transplantation in stroke, including the first cell therapy in stroke patients.  Recently a team led by Dr. Borlongan offered a new concept for how transplanted stem cells help prod the brain’s own repair mechanism following traumatic brain injury. Based in part on this preclinical study, the U.S. Food and Drug Administration approved a limited clinical trial to transplant an adult stem cell therapy in patients with traumatic brain injury.

Cesario Borlongan, PhD

Dr. Borlongan has received continuous federal funding totaling more than $15 million from the Department of Veterans Affairs, the Department of Defense and the NIH since 2002. A fellow of the American Association for the Advancement of Science, Dr. Borlongan is president-elect of the American Society for Neural Therapy and Repair for 2015.

The Distinguished USF Health Professor award recognizes senior faculty across all USF Health colleges and programs for their substantial achievements in the areas of research, teaching and service. Faculty members are nominated by their deans, recommended by their peers and selected through a rigorous process of internal and external review of each nominee’s credentials.

In addition to receiving a $5,000 base salary adjustment, Dr. Birk and Dr. Borlongan are invited to give a USF Health address during the academic year, and are granted the State University System title of Distinguished USF Health Professor.  A commemorative medallion will be awarded to each at the Annual Research Day Lectureship in February.

Since the inaugural awards were bestowed in 2007, 19 faculty members have been named Distinguished USF Health Professors. Other MCOM faculty with the designation include Shyam Mohapatra, PhD; Benjamin Djulbegovic, MD, ScD; and David Morgan, PhD; David Sheehan, MD; Michael Barber, DPhil; Jeffrey Krischer, PhD; Bruce Lindsey, PhD; and Richard Lockey, MD.

Four USF Health faculty members were among 11 recipients of the university’s 2013 Faculty Outstanding Research Achievement Awards.

Cesario Borlongan, PhD; Chad Dickey, PhD; and Benjamin Djulbegovic, MD, PhD, all of the Morsani College of Medicine;  and Wilbur Milhous, PhD, of the College of Public Health, joined awardees honored at an Oct. 28 awards luncheon hosted by the USF Office of Research and Innovation.

L to R: USF Senior Vice Provost Dr. Dwayne Smith, USF President Judy Genshaft, award recipient Dr. Benjamin Djulbegovic, and Dr. Paul Sanberg, senior vice president for research and innovation.

The annual awards both celebrate USF faculty members for publications, awards and grants exemplifying their outstanding scholarship and research and underscore the professional recognition that they attracted the previous calendar year from national and international peers. The USF System Research Council selects awardees based on an open competition.

Dr. Borlongan, professor and vice chair for research, neurosurgery and brain repair, and director of the Center for Aging and Brain Repair at the Morsani College of Medicine, was recognized for his research and scholarly work in translational biomedical research.  In 2012 he was elected a fellow of the American Association for the Advancement of Science based on his research on stem cell therapy for stroke. He published 23 peer-reviewed articles in journals such as PloS One and Stem Cells and Development, filed a patent application, and became principal investigator on two federal grants, a James and Esther King state grant, and co-investigator on a VA Merit award.

Cesar Borlongan, PhD, (left) and Chad Dickey, PhD

Dr. Dickey, associate professor of molecular medicine at the Morsani College of Medicine and USF Health Byrd Alzheimer’s Institute, was recognized for his research studies on the molecular mechanisms underlying neurodegeneration. In 2012, he published eight manuscripts in top journals: Journal of Biological Chemistry, Autophagy, Chemistry & Biology, ACS Chemical Biology, and Journal of Molecular Biology. Four papers focused on compounds that target members of the heat shock proteins family, which Dr. Dickey found to have therapeutic potential. This discovery has advanced knowledge of the biological mechanism used by the cell to deal with protein aggregates and led to the discovery of a leading drug candidate for treatment of Alzheimer’s disease.

Dr. Djulbegovic is a distinguished professor and director, Division of Evidence-Based Medicine and Health Outcomes Research, Department of Internal Medicine, Morsani College of Medicine. He was recognized for his work in 2012 on the development of two major theories in clinical research and decision-making:  the theory regarding treatment success in clinical trials and the acceptable regret theory.  His contributions include improving the practice of medicine using the following evidence-based medicine methods: predicting and proving the optimal treatment discovery rate, developing a new theory of medical decision-making, and improving patient outcomes and saving resources by generating evidence-based guidelines.

Wilbur Milhous, PhD

Dr. Milhous, professor of the Global Health Infectious Disease Research Program and associate dean of research, College of Public Health, was recognized for his research translating technology from the laboratory to the field. In 2012, Dr. Milhous was designated a distinguished alumnus from the University of North Carolina for his contributions to the discovery and development of drugs for neglected diseases.  He also completed a five-year appointment representing USF on the Advisory Committee of the Medicines for Malaria Venture (MMV), which holds the world’s largest research and development portfolio for new and innovative antimalarial medicines, and was appointed as an editor of Antimicrobial Agents and Chemotherapy, the leading journal for infectious disease drugs.

Group photo by Aimee Blodgett, University Communications and Marketing