Stem Cell Research Center – University of Pittsburgh

At the University of Pittsburgh / Children's Hospital of Pittsburgh of UPMC Stem Cell Research Center (SCRC), scientists and physicians are working around the clock to expand the possibilities of tissue engineering by unlocking the potential of gene therapy and adult stem cell research and transferring research findings into the development of effective treatments for damaged or diseased tissues. Medicine has moved from treating the pain of injuries to treating their cause and the SCRC has taken the initiative to lead this movement in the area of cellular therapeutics.

Led by Dr. Johnny Huard, the faculty and staff of the SCRC are using cutting edge technology in cellular techniques, observation, and analyzation to seek out the answers to the cellular therapies of tomorrow. Muscular injuries, including muscular dystrophy, bone fractures, nervous system conduction pathways, cardiac repair, and vascular blockages are all being targeted by the Center as areas of keen interest in medicine. Each member of the center along with their projects and individual skills are focused on the translation of their research from the Center's laboratories into your clinic.

The SCRC is a fully collaborative center spanning many disciplines throughout the University of Pittsburgh Medical Center (UPMC) and the Children's Hospital of Pittsburgh of UPMC. Many of the Center's collaborative colleagues reside in the focus groups within its laboratories.

The Departments of Orthopaedics, Cardiothroacic Surgery, and Rehabilitation along with the Pittsburgh Cancer Institute and the McGowan Center for Regenerative Medicine, among others, each share in the SCRC's goals for the future of cellular regenerative medicine.

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Stem Cell Research Center - University of Pittsburgh

Stem cell program – KU Medical Center

A primary and high-priority area of interest in the CVRI involves investigation of adult stem cell biology and therapy. A growing body of evidence supports the notion that transplantation of adult stem/progenitor cells can induce cardiac repair and improve left ventricular function and structure after myocardial infarction. The stem cell program in the CVRI conducts research to identify the optimal cell for this purpose and to enhance the outcomes via modification of cells before transplantation.

The major goals of the stem cell program are:

Relevant projects:

Mesenchymal stem cell therapy for infarct repair: Mesenchymal stem cells represent a rare population of primitive cells that reside in the bone marrow and participate in organ repair following injury. Injection of these cells after myocardial infarction can repair the heart and improve left ventricular function. These studies are broadly directed at improving the outcomes of MSC therapy for cardiac repair.

Wnt11 signaling in stem cell-induced cardiac repair: Wnt11 is a member of the 'wingless' family of glycoproteins that participate in various biological processes, including cellular proliferation, differentiation, and migration during development. The goal of this project is to delineate the role of Wnt11 signaling in differentiation of adult bone marrow cells and in cardiac repair.

Pretreatment of stem cells for greater cardiac differentiation: Our laboratory has extensive experience with the induction of cellular differentiation using various defined media. The primary goal of this project is to identify biological agents that will direct differentiation of adult stem/progenitors in cardiac lineages.

Investigators, trainees, and associates:

Last modified: Apr 01, 2014

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Stem cell program - KU Medical Center

New stem cell research retracted

Almost five months after publication, Nature retracted two papers regarding new stem cell research. This retraction came after various errors were spotted, both in the papers presented and the attempted recreations of the experiments described. The research, which claimed that embryonic stem cells could be created by exposing normal skin cells to stress, appeared to be a medical breakthrough at the time of publication.

The lead author was found guilty of misconduct, while her employer was threatened numerous times with dismantlement, reports Scientific American. It appeared that parts of the methods were plagiarized from previous studies in the stem cell field, and the supposed 'different' cells and embryos described in the study were actually the same.

It was only after recreation of the described methods failed that the errors were brought forth and scrutinized by various outside sources, including one of the co-authors. The Riken Center for Developmental Biology in Japan began in-depth investigations into the studies in February 2014, and categorized some of the major errors that skewed the written results as misconduct, reports Uncover California.

Nature released a statement regarding the publication, saying, "The episode has further highlighted flaws in Natures procedures and in the procedures of institutions that publish with us."

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New stem cell research retracted

Stem cell type resists chemotherapy drug

A new study shows that adipose-derived human stem cells, which can become vital tissues such as bone, may be highly resistant to the common chemotherapy drug methotrexate (MTX). The preliminary finding from lab testing may prove significant because MTX causes bone tissue damage in many patients.

MTX is used to treat cancers including acute lymphoblastic leukemia, the most common form of childhood cancer. A major side effect of the therapy, however, is a loss of bone mineral density. Other bone building stem cells, such as bone marrow derived stem cells, have not withstood MTX doses well.

"Kids undergo chemotherapy at such an important time when they should be growing, but instead they are introduced to this very harsh environment where bone cells are damaged with these drugs," said Olivia Beane, a Brown University graduate student in the Center for Biomedical Engineering and lead author of the study. "That leads to major long-term side effects including osteoporosis and bone defects. If we found a stem cell that was resistant to the chemotherapeutic agent and could promote bone growth by becoming bone itself, then maybe they wouldn't have these issues."

Stem cell survivors

Originally Beane was doing much more basic research. She was looking for chemicals that could help purify adipose-derived stem cells (ASCs) from mixed cell cultures to encourage their proliferation. Among other things, she she tried chemotherapy drugs, figuring that maybe the ASCs would withstand a drug that other cells could not. The idea that this could help cancer patients did not come until later.

In the study published online in the journal Experimental Cell Research, Beane exposed pure human ASC cultures, "stromal vascular fraction" (SVF) tissue samples (which include several cell types including ASCs), and cultures of human fibroblast cells, to medically relevant concentrations of chemotherapy drugs for 24 hours. Then she measured how those cell populations fared over the next 10 days. She also measured the ability of MTX-exposed ASCs, both alone and in SVF, to proliferate and turn into other tissues.

Beane worked with co-authors fellow center member Eric Darling, the Manning Assistant Professor in the Department of Molecular Pharmacology, Physiology and Biotechnology, and research assistant Vera Fonseca.

They observed that three chemotherapy drugs -- cytarabine, etoposide, and vincristine -- decimated all three groups of cells, but in contrast to the fibroblast controls, the ASCs withstood a variety of doses of MTX exceptionally well (they resisted vincristine somewhat, too). MTX had little or no effect on ASC viability, cell division, senescence, or their ability to become bone, fat, or cartilage tissue when induced to do so.

The SVF tissue samples also withstood MTX doses well. That turns out to be significant, Darling said, because that's the kind of tissue that would actually be clinically useful if an ASC-based therapy were ever developed for cancer patients. Hypothetically, fresh SVF could be harvested from the fat of a donor, as it was for the study, and injected into bone tissue, delivering ASCs to the site.

To understand why the ASCs resist MTX, the researchers conducted further tests. MTX shuts down DNA biosynthesis by binding the protein dihydrofolate reductase so that it is unavailable to assist in that essential task. The testing showed that ASCs ramped up dihydrofolate reductase levels upon exposure to the drug, meaning they produced enough to overcome a clinically relevant dose of MTX.

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Stem cell type resists chemotherapy drug

"Stress-Induced" Stem Cell Findings Are Retracted

High-profile reports claiming an easy way to create pluripotent cells were flawed.

The controversial work involved a mouse embryo injected with cells made pluripotent through stress. Credit: Haruko Obokata

Naturetoday retracted two controversial papers on stem cells that it published in January. The retractions agreed to by all of the co-authors come at the end of a whirlwind five months during which various errors were spotted in the papers, attempts to replicate the experiments failed, the lead author was found guilty of misconduct, and the centre where she is employed was threatened with dismantlement. The retraction noticeincludes a handful of problems with the papers that had not been previously considered by institutional investigation teams.

Questions remain over what exactly was the basis for claims that embryonic-like stem cells could be created by exposing bodily cells to stress a technology the authors called stimulus-triggered acquisition of pluripotency, orSTAP. But the controversy promises to have lasting impact on science in Japan, global stem-cell research, and the scientific community more broadly including changes in editorial policy at Nature. AnEditorial posted todaywith the retractions notes the need for improvements in publishing procedures: The episode has further highlighted flaws inNatures procedures and in the procedures of institutions that publish with us. (Natures news and comment team is editorially independent of its research editorial team.)

The first of the two papersdescribed a method of using acid exposure or physical pressure to convert spleen cells from newborn mice into pluripotent cells cells that can become any cell in the body. The second paperfurther impressed stem-cell scientists with data showing that the STAP process created cells that could differentiate into placenta cells, something that other pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells, do not normally do.

But within weeks, duplicated and manipulated images were discovered, focusing attention on the source of data provided by Haruko Obokata, a biochemist at the RIKEN Center for Developmental Biology in Kobe and first author on both papers. Scientists also reported difficulties in replicating the experiments.

A RIKEN investigation team looking into the papers announced on April 1 that Obokata had been foundguilty of two counts of scientific misconduct. RIKENrejected an appeal, and advised her to retract the papers in May. Co-author Teruhiko Wakayama of the University of Yamanishi had been arguing for retraction since March.

Obokata and Charles Vacanti, an anaesthesiologist at the Brigham and Womens Hospital in Boston, Massachusetts, and the senior corresponding author on the first article, both stood by its claims, but later changed their positions after new errors emerged. Obokatagave her consent to the retraction of both paperson June 4.

The retraction notice published today lists five new errors. The first four note that captions do not describe what is in the corresponding images or figures, without reflecting on how this relates to the experimental data. The fifth, relating to the first paper, notes that purported STAP cells are of a different genetic background from those supposedly used in the experiments something it calls inexplicable discrepancies.

The notice concludes: These multiple errors impair the credibility of the study as a whole and we are unable to say without doubt whether the STAP-SC [stem cell] phenomenon is real.

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"Stress-Induced" Stem Cell Findings Are Retracted

Some stem cell methods closer to 'gold standard' than others

PUBLIC RELEASE DATE:

2-Jul-2014

Contact: Kristina Grifantini press@salk.edu Salk Institute

LA JOLLA-Researchers around the world have turned to stem cells, which have the potential to develop into any cell type in the body, for potential regenerative and disease therapeutics.

Now, for the first time, researchers at the Salk Institute, with collaborators from Oregon Health & Science University and the University of California, San Diego, have shown that stem cells created using two different methods are far from identical. The finding could lead to improved avenues for developing stem cell therapies as well as a better understanding of the basic biology of stem cells.

The researchers discovered that stem cells created by moving genetic material from a skin cell into an empty egg cell-rather than coaxing adult cells back to their embryonic state by artificially turning on a small number of genes-more closely resemble human embryonic stem cells, which are considered the gold standard in the field.

"These cells created using eggs' cytoplasm have fewer reprogramming issues, fewer alterations in gene expression levels and are closer to real embryonic stem cells," says co-senior author Joseph R. Ecker, professor and director of Salk's Genomic Analysis Laboratory and co-director of the Center of Excellence for Stem Cell Genomics. The results of the study were published today in Nature.

Human embryonic stem cells (hESCs) are directly pulled from unused embryos discarded from in-vitro fertilization, but ethical and logistical quandaries have restricted their access. In the United States, federal funds have limited the use of hESCs so researchers have turned to other methods to create stem cells. Most commonly, scientists create induced pluripotent stem (iPS) cells by starting with adult cells (often from the skin) and adding a mixture of genes that, when expressed, regress the cells to a pluripotent stem-cell state. Researchers can then coax the new stem cells to develop into cells that resemble those in the brain or in the heart, giving scientists a valuable model for studying human disease in the lab.

Over the past year, a team at OHSU built upon a technique called somatic cell nuclear transfer (the same that is used for cloning an organism, such as Dolly the sheep) to transplant the DNA-containing nucleus of a skin cell into an empty human egg, which then naturally matures into a group of stem cells.

Ecker, holder of the Salk International Council Chair in Genetics, teamed up with Shoukhrat Mitalipov, developer of the new technique and director of the Center for Embryonic Cell and Gene Therapy at OHSU, and UCSD assistant professor Louise Laurent to carry out the first direct comparison of the two approaches. The scientists created four lines of nuclear transfer stem cells all using eggs from a single donor, along with seven lines of iPS cells and two lines of the gold standard hESCs. All cell lines were shown to be able to develop into multiple cell types and had nearly identical DNA content contained within them.

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Some stem cell methods closer to 'gold standard' than others

Research integrity: Cell-induced stress

Kimimasa Mayama/EPA/Alamy

Haruko Obokata tearfully faces the media after she was found guilty of misconduct in April.

It seemed almost too good to be true and it was. Two papers1, 2 that offered a major breakthrough in stem-cell biology were retracted on 2 July, mired in a controversy that has damaged the reputation of several Japanese researchers.

For scientists worldwide it has triggered painful memories of a decade-old scandal. In February 2004, South Korean researcher WooSuk Hwang announced that he had generated stem-cell lines from cloned human embryos3, creating a potential source of versatile, therapeutic cells that would be genetically matched to any patient. A frenzy of excitement followed this and a subsequent publication4, but that didnt compare with the media firestorm when the results were revealed to be fabricated. The two main cloning papers were retracted5, and the careers of some dozen scientists were devastated.

In the soul-searching that followed, research integrity became a hot topic, scientists re-evaluated the responsibilities of authorship, and institutions vowed to improve the way that they police their staff. Nature and other journals also made promises, saying that they would vet manuscripts more thoroughly. In an Editorial at the time, Nature wrote6: Keeping in mind the principle that extraordinary claims require extraordinary proof, Nature may in rare cases demand it.

A year later, when Shoukhrat Mitalipov of the Oregon Health & Science University in Portland claimed to have cloned embryonic-stem-cell lines from monkeys7, Nature required independent tests to verify that the lines came from the monkey donors. This verification was published alongside the cloning paper8. I applaud what they did, says Alan Trounson, the outgoing president of the California Institute for Regenerative Medicine in San Francisco, who helped with the testing.

Then came Japans stem-cell case. This January, Haruko Obokata, a young biochemist at the RIKEN Center for Developmental Biology (CDB) in Kobe, Japan, reported in Nature1, 2 that she had converted mouse cells to an embryonic-like state merely by subjecting them to stress, such as physical pressure or exposure to acid (see Nature 505, 596; 2014). The process, labelled stimulus-triggered acquisition of pluripotency (STAP), was so contrary to current thinking that some scientists said they accepted it based only on the reputation of Obokatas co-authors, who were some of the most trusted names in stem-cell research and cloning.

But the paper1 that set out the fundamental technique was soon shot full of holes. There was plagiarized text in the article. Figures showed signs of manipulation, and some images were identical or nearly identical to those used later in the same paper and elsewhere to represent different experiments. More damning were genetic analyses that strongly suggested the cells were not what they were purported to be. And although deriving STAP cells was advertised as simple and straightforward, no one has yet been able to repeat the experiment.

Within the space of six months, Obokata was found guilty of misconduct by her institution; well-respected scientists, including RIKEN head Ryoji Noyori, bowed their heads in apology; and both papers were retracted9. In the end, the evidence for STAP cells seemed so flimsy that observers began to ask where were the extra precautions and the extraordinary proof that had been promised post-Hwang.

The case has reopened difficult questions about the quality of research and peer review, and the responsibilities of co-authors, institutions and journals. It is also making its mark as an example of how not to do things. The episode has already become a parable in my lab for teaching students about scientific ethics, says Jeanne Loring, a stem-cell biologist at the Scripps Research Institute in La Jolla, California.

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Research integrity: Cell-induced stress

Artificial embryonic stem cells have quality problems: study

Salk Institute scientist Joseph Ecker holds a flow cell slide used in a genome sequencing machine. Ecker and colleagues compared the genomes of two kinds of artificial embryonic stem cells for a study comparing their quality.

In a setback for hopes of therapy with a promising kind of artificial embryonic stem cells, a study published in the journal Nature has found that these "induced pluripotent stem cells" have serious quality issues.

However, scientists who performed the study, including researchers from the Salk Institute and UC San Diego, say it should be possible to improve the quality of these IPS cells. They say lessons can be learned from studying a newer technique of making human embryonic stem cells through nuclear transfer, the same technology used to create Dolly the cloned sheep.

In addition, the study does not prove that the quality problems will affect therapy with the cells, said scientists who examined the study. That remains to be tested.

The IPS cells are made from skin cells treated with "reprogramming" factors that turn back the clock, so they very closely resemble embryonic stem cells. The hope is that these IPS cells could be differentiated into cells that can repair injuries or relieve diseases. Because they can be made from a patient's own cells, the cells are genetically matched, reducing worries of immune rejection.

In San Diego, scientists led by Jeanne Loring at The Scripps Research Institute have created IPS cells from the skin cells of Parkinson's disease patients, and turned the IPS cells into neurons that produce dopamine. They hope to get approval next year to implant these cells into the patients, relieving symptoms for many years. The project is online under the name Summit4StemCell.org.

A major concern is that IPS cells display abnormal patterns of gene activation and repression. This is controlled by a process called methylation. This process adds chemicals called methyl groups to DNA, but these "epigenetic" changes do not change the underlying DNA sequence. Methylation represses gene function; removing the methyl groups, or demethylation, activates them.

The Nature study was led by Shoukhrat Mitalipov of Oregon Health & Scence University. Mitalipov made headlines last year for applying nuclear transfer to derive human embryonic stem cells, the first time this has been achieved in human cells. These cells can be made to be a near-perfect genetic match to the patient, and their quality closely resembles those of true embryonic stem cells.

"We know that the embryonic stem cells are the gold standard, and we've been always trying to make patient-matched cells that would match the gold standard," Mitalipov said. "And at this point it looks like the NT (nuclear transfer) cells produce exactly those cells that would be best."

Nuclear transfer involves placing a nucleus from a skin cell into an egg cell that has had its nucleus removed. The cell is then stimulated, and starts dividing in the same way a fertilized egg cell divides to form an embryo.

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Artificial embryonic stem cells have quality problems: study

Adults stop anti-rejection drugs after stem-cell transplant reverses sickle cell disease

PUBLIC RELEASE DATE:

1-Jul-2014

Contact: Krysten Carrera NIDDKMedia@mail.nih.gov 301-496-3583 NIH/National Institute of Diabetes and Digestive and Kidney Diseases

Adults stop anti-rejection drugs after stem-cell transplant reverses sickle cell disease NIH trial success suggests a new treatment option for older, sicker patients

Half of patients in a trial have safely stopped immunosuppressant medication following a modified blood stem-cell transplant for severe sickle cell disease, according to a study in the July 1 issue of the Journal of the American Medical Association. The trial was conducted at the National Institutes of Health's Clinical Center in Bethesda, Maryland, by researchers from NIH's National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and the National Heart, Lung, and Blood Institute.

The transplant done in the study reversed sickle cell disease in nearly all the patients. Despite having both donor stem-cells and their own cells in their blood, the patients stopped the immunosuppressant medication without experiencing rejection or graft-versus-host disease, in which donor cells attack the recipient. Both are common, serious side effects of transplants.

"Typically, stem-cell recipients must take immunosuppressants all their lives," said Matthew Hsieh, M.D., lead author on the paper and staff clinician at NIH. "That the patients who discontinued this medication were able to do so safely points to the stability of the partial transplant regimen."

In sickle cell disease (SCD) sickle-shaped cells block blood flow. It can cause severe pain, organ damage and stroke. The only cure is a blood stem-cell, or bone marrow, transplant. The partial transplant performed in the study is much less toxic than the standard "full" transplant, which uses high doses of chemotherapy to kill all of the patient's marrow before replacing it with donor marrow. Several patients in the study had less than half of their marrow replaced.

Immunosuppressant medication reduces immune system strength and can cause serious side effects such as infection and joint swelling. In this study, 15 of 30 adults stopped taking the medication under careful supervision one year after transplant and still had not experienced rejection or graft-versus-host disease at a median follow up of 3.4 years.

"Side effects caused by immunosuppressants can endanger patients already weakened by years of organ damage from sickle cell disease," said John F. Tisdale, M.D., the paper's senior author and a senior investigator at NIH. "Not having to permanently rely on this medication, along with use of the relatively less-toxic partial stem-cell transplant, means that even older patients and those with severe sickle cell disease may be able to reverse their condition."

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Adults stop anti-rejection drugs after stem-cell transplant reverses sickle cell disease

Papers on stress-induced stem cells are retracted

Asahi Shimbun/Getty Images

Haruko Obokata, here at a 9 April news conference in Osaka, Japan, was found guilty of misconduct but stands by her claim of having produced stem cells by a novel procedure.

Nature today retracted two controversial papers on stem cells that it published in January1, 2. The retractions agreed to by all of the co-authors come at the end of a whirlwind five months during which various errors were spotted in the papers, attempts to replicate the experiments failed, the lead author was found guilty of misconduct, and the centre where she is employed was threatened with dismantlement. The retraction notice3 includes a handful of problems with the papers that had not been previously considered by institutional investigation teams.

Questions remain over what exactly was the basis for claims that embryonic-like stem cells could be created by exposing bodily cells to stress a technology the authors called stimulus-triggered acquisition of pluripotency, or STAP. But the controversy promises to have lasting impact on science in Japan, global stem-cell research, and the scientific community more broadly including changes in editorial policy at Nature. An Editorial posted today with the retractions notes the need for improvements in publishing procedures: The episode has further highlighted flaws in Natures procedures and in the procedures of institutions that publish with us. (Natures news and comment team is editorially independent of its research editorial team.)

The first of the two papers1 described a method of using acid exposure or physical pressure to convert spleen cells from newborn mice into pluripotent cells cells that can become any cell in the body. The second paper2 further impressed stem-cell scientists with data showing that the STAP process created cells that could differentiate into placenta cells, something that other pluripotent stem cells, such as embryonic stem cells and induced pluripotent stem cells, do not normally do.

But within weeks, duplicated and manipulated images were discovered, focusing attention on the source of data provided by Haruko Obokata, a biochemist at the RIKEN Center for Developmental Biology in Kobe and first author on both papers. Scientists also reported difficulties in replicating the experiments.

A RIKEN investigation team looking into the papers announced on 1 April that Obokata had been found guilty of two counts of scientific misconduct. RIKEN rejected an appeal, and advised her to retract the papers in May. Co-author Teruhiko Wakayama of the University of Yamanishi had been arguing for retraction since March.

Obokata and Charles Vacanti, an anaesthesiologist at the Brigham and Womens Hospital in Boston, Massachusetts, and the senior corresponding author on the first article, both stood by its claims, but later changed their positions after new errors emerged. Obokata gave her consent to the retraction of both papers on 4 June.

The retraction notice published today lists five new errors. The first four note that captions do not describe what is in the corresponding images or figures, without reflecting on how this relates to the experimental data. The fifth, relating to the first paper1, notes that purported STAP cells are of a different genetic background from those supposedly used in the experiments something it calls inexplicable discrepancies.

The notice concludes: These multiple errors impair the credibility of the study as a whole and we are unable to say without doubt whether the STAP-SC [stem cell] phenomenon is real.

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Papers on stress-induced stem cells are retracted