Great Day in Ft. Worth for Stem Cell Team

Stem cell patients and MS walk in Fort Worth

Stem Cell Institute patients participate in MS Walk 2012

Saturday, March 31 was the annual MS Walk in Ft Worth. This year, thanks to the Stem Cell Institute and some of the area stem cell patients, several of us MS sufferers and stem cell patients met for the Walk. Here’s a picture of several of us who have been to Panama, or Costa Rica, for treatments – (from L – R) Richard, Carolyn, Shelley, Carla, Judi, Holly, and me.

We wanted to give the Stem Cell Institute a presence in that sea of MS victims and caregivers. I wish all of them knew that many of us in those blue t-shirts were there walking, actually completing the whole mile, even though we were once unable to do such. I wanted to grab that microphone that the organizers were using and tell all of them “There is HOPE – it doesn’t have to be what you hear from your doctors so often. It can be more than ‘Let’s keep taking this medication so you might get worse at a slower rate’ ”

I personally never heard about the possibility of actually improving when I went to good doctors here in the US – but I chose to try the Stem Cell treatment in Panama, and I walked that mile on Saturday! A year ago, six months ago, I couldn’t have done that – but after my third trip to Panama in September, my walking, my balance, and my stamina all improved dramatically. And many of those in our group on Saturday have a similar story; some results more dramatic than others, but most all of us have seen and felt the changes that give us that Hope that all of those sufferers at the Walk are looking for.

THANKS STEM CELL INSTITUTE!

Sam Harrell
Sam in Panama

Stemedica Treats First Patient with Ischemic Allogeneic Mesenchymal Stem Cells

Stemedica Cell Technologies Press Release
The San Diego stem cell company Stemedica Cell Technologies, Inc reported treatment of its first patient as part of a 35 patient clinical trial in stroke patients. The study uses bone marrow stem cells that have been preconditioned with hypoxia and used in a non-matched manner. The trial is being conducted at the University of California San Diego and is titled “A Phase I/II, Multi-Center, Open-Label Study to Assess the Safety, Tolerability and Preliminary Efficacy of a Single Intravenous Dose of Allogeneic Mesenchymal Bone Marrow Cells to Subjects with Ischemic Stroke.”
Every year more than 800,000 Americans suffer a stroke. According to the American Heart Association, stroke is the fourth leading cause of death – costing an estimated $73.7 billion in 2010 for stroke-related medical costs and disability.
The study’s Principle investigator is Michael Levy, MD, PhD, FACS, chief of pediatric neurosurgery at Children’s Hospital San Diego (CHSD) and professor of neurological surgery at UCSD. The aim of the trial is to determine tolerance and therapeutic outcomes for intravenously-delivered adult allogeneic mesenchymal stem cells and to hopefully pave the way for a new therapeutic category of treatment for ischemic stroke. When asked about the first patient in the study, Dr. Levy said, “The treatment went smoothly; no side effects were observed, and the patient was released from the hospital the next day.”
Lev Verkh, PhD, Stemedica’s chief regulatory and clinical development officer, commented: “Many years of research and hard work by the Stemedica team culminated today in the treatment of the first patient using our uniquely designed stem cells to be effective under ischemic condition. We are proud to be the first company to initiate a study such as this under a clinical protocol approved by the U.S. Food and Drug Administration (FDA).”
Several companies are using stem cells for stroke. For example the company Aldagen is using bone marrow derived cells from the same patient. Their approach involves bone marrow extraction, purification of a selected stem cell from the bone marrow, and subsequent administration of the cell into the patients. The reason why stroke is of great interest to many companies is because recent studies have demonstrated that the brain has its own stem cells that start multiplying after a stroke. Unfortunately these stem cells that are already existing are not found in a high enough number to cause a substantial repair. The idea is that when new stem cells are added, they assist the existing stem cells in supporting the repair process.
“This clinical trial marks a significant achievement in the treatment of debilitating ischemia-related pathologies including ischemic stroke,” said Nikolai Tankovich, MD, PhD, president and chief medical officer of Stemedica. “We believe these specially designed mesenchymal stem cells are able to tolerate, survive and repair ischemic tissues caused by an infarction of the brain, heart, kidney, retina and other organs. In addition, these mesenchymal stem cells are capable of up regulating an array of important genes that are essential for the synthesis of critical proteins involved in recovery.”
Dr. Verkh continued, “Patients in this study have significant functional or neurologic impairment that confines them to a wheelchair or requires home nursing care or assistance with the general activities of daily living and have received the ischemic stroke diagnosis at least six months prior to enrollment in this study”.
The inclusion/exclusion criteria are:
Inclusion Criteria:
•Clinical diagnosis of ischemic stroke for longer than 6 months
•Brain CT/MRI scan at initial diagnosis and at enrollment consistent with ischemic stroke
•No substantial improvement in neurologic or functional deficits for the 2 months prior to enrollment
•NIHSS score between 6-20
•Life expectancy greater than 12 months
•Prior to treatment patient received standard medical care for the secondary prevention of ischemic stroke
•Adequate organ function as defined by the following criteria:
Exclusion Criteria:
•History of uncontrolled seizure disorder
•History of cancer within the past 5 years.
•History of cerebral neoplasm
•Positive for hepatitis B, C or HIV
•Myocardial infarction withing six months of study entry
•Findings on baseline CT suggestive of subarachnoid or intracerebral hemorrhage within past 12 months.
•Allergies to Bovine or Porcine products

Medistem Signs Exclusive Worldwide License With Yale University for Treatment of Type 1 Diabetes Using Stem Cells

Acquisition of Intellectual Property and Data Leads to Expansion of Medistem Therapeutic Pipeline

SAN DIEGO, CA, Mar 07, 2012 (MARKETWIRE via COMTEX) — Medistem Inc. (pinksheets:MEDS) and Yale University have signed an exclusive worldwide licensing agreement covering the generation of pancreatic islets from stem cells such as the Endometrial Regenerative Cell (ERC). These pancreatic islets have effectively treated diabetes in animal models.

Professor Hugh Taylor of Yale University, inventor of the technology, made international headlines in September 2011 when he published his findings in the peer-reviewed journal Molecular Therapy.

“Medistem is the first company to develop clinical-grade endometrial-derived stem cells and initiate trials in humans,” said Professor Taylor. “Since Medistem’s Endometrial Regenerative Cells are manufactured inexpensively, can be used as an ‘off the shelf’ product, and to date appear safe in human subjects, I am very excited to see diabetes added to the list of diseases that can potentially be treated with Medistem’s ERCs.”

Medistem is currently in two clinical trials with ERCs: One for critical limb ischemia and a second for congestive heart failure, both of which are complications of uncontrolled diabetes.

“Type 1 diabetes is a rapidly growing poorly-served market. There is great optimism that cell-based therapies can address not only pancreatic degeneration but also the underlying immunological causes,” said Dr. Alan Lewis, former CEO of the Juvenile Diabetes Research Foundation, the largest non-profit organization focused on development of new therapeutic approaches for this disease. “The ERC is the newest adult stem cell to enter clinical trials. Based on this unique source of cells, as well as their immune modulatory properties, we believe this work may be expanded into other autoimmune diseases.”

About Medistem Inc. Medistem Inc. is a biotechnology company developing technologies related to adult stem cell extraction, manipulation, and use for treating inflammatory and degenerative diseases. The company’s lead product, the endometrial regenerative cell (ERC), is a “universal donor” stem cell being developed for critical limb ischemia and congestive heart failure. A publication describing the support for use of ERC for this condition may be found at http://www.translational-medicine.com/content/pdf/1479-5876-6-45.pdf . ERC can be purchased for scientific use through Medistem’s collaborator, General Biotechnology http://www.gnrlbiotech.com/?page=catalog_endometrial_regenerative_cells .

Cautionary Statement This press release does not constitute an offer to sell or a solicitation of an offer to buy any of our securities. This press release may contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking information. Factors which may cause actual results to differ from our forward-looking statements are discussed in our Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission.

Medistem Inc. to Add Kidney and Lung Failure to Clinical Trials of Endometrial Regenerative Cells (ERC) Stem Cells in Russia

SAN DIEGO, CA and PORTLAND, OR, Mar 05, 2012 (MARKETWIRE via COMTEX) — Medistem Inc. (pinksheets:MEDS), in partnership with its Russian licensee, ERCell, announced the signing of a letter of intent* to begin clinical trials using Medistem’s Endometrial Regenerative Cells (ERC) stem cells for renal, lung and peripheral artery disease. Trials will be conducted in the S.M. Kirov Military Medical Academy in St. Petersburg, Russia. Under the agreement, Medistem, ERCell and the Academy will work together to a) Design and obtain approval for clinical trials; b) Provide training and execute the trials; and c) Identify opportunities for commercialization of the ERC product through existing military and governmental programs.

Under the license agreement, Medistem receives cash and royalty revenues from Russian developmental activities as well as all the data gathered from the trials. According to the agreement, work performed by ERCell will be conducted according to international “Good Clinical Practices” (GCP) so the data gathered can be used for Russian registration as well as to support US FDA submissions.

“At Medistem, our philosophy has always been to follow the data. We aim to be as aggressive as possible, to obtain as much data as possible, as quickly as possible,” stated Thomas Ichim, CEO of Medistem. “We are especially optimistic about the possibility of obtaining human data in renal failure patients, something that we otherwise would not have pursued at this stage if it weren’t for the support of the S.M. Kirov Military Medical Academy.”

“As the Medistem licensee for Russia and CIS (Commonwealth of Independent States), ERCell is committed to advancing our programs using as many non-dilutive means as possible,” said Tereza Ustimova, CEO of ERCell. “By partnering with the best institutes in the country, we are committed to making ERCell Russia’s premiere universal donor adult stem cell company.”

S.M. Kirov Military Medical Academy conducts research in the following areas: metabolic derangements of cardiovascular pathology, nanotechnologies in biology and medicine, stem cells as a basis for the treatment of internal organs and blood diseases, blood circulation, vegetative nervous system and high-tech methods of diagnosis and treatment.

“We are highly impressed by the fact that the Endometrial Regenerative Cell (ERC) is the newest stem cell product to enter clinical trials. By the higher growth factor production ability compared to other types of stem cells, we are very eager to begin clinical trials,” said Oleg Nagobovich, M.D., Chief of the Research Center, S.M. Kirov Medical Military Academy. “We feel our work will complement the ongoing work at the Backulev Center addressing heart failure by Medistem/ERCell.”

*Letter of intent issued by Ministry of Defense, dated 2/24/12, No. 411A/119

About Medistem Inc. Medistem Inc. is a biotechnology company developing technologies related to adult stem cell extraction, manipulation, and use for treating inflammatory and degenerative diseases. The company’s lead product, the endometrial regenerative cell (ERC), is a “universal donor” stem cell being developed for critical limb ischemia. A publication describing the support for use of ERC for this condition may be found at http://www.translational-medicine.com/content/pdf/1479-5876-6-45.pdf . ERC can be purchased for scientific use through Medistem’s collaborator, General Biotechnology http://www.gnrlbiotech.com/?page=catalog_endometrial_regenerative_cells .

Cautionary Statement This press release does not constitute an offer to sell or a solicitation of an offer to buy any of our securities. This press release may contain certain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified. Future events and actual results could differ materially from those set forth in, contemplated by, or underlying the forward-looking information. Factors which may cause actual results to differ from our forward-looking statements are discussed in our Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission.

Contact:
Thomas Ichim
Chief Executive Officer
Medistem Inc.
9255 Towne Centre Drive, Suite 450
San Diego, CA 92122
858 349 3617
858 642 0027

www.medisteminc.com twitter: @thomasichim

SOURCE: Medistem Inc.

Autologous stromal vascular fraction therapy for rheumatoid arthritis: rationale and clinical safety.

Int Arch Med. 2012 Feb 8;5(1):5. [Epub ahead of print]

Paz Rodriguez J, Murphy MP, Hong S, Madrigal M, March KL, Minev B, Harman RJ, Chen CS, Timmons RB, Marleau AM, Riordan NH.

ABSTRACT: Advancements in rheumatoid arthritis (RA) treatment protocols and introduction of targeted biological therapies have markedly improved patient outcomes, despite this, up to 50% of patients still fail to achieve a significant clinical response. In veterinary medicine, stem cell therapy in the form of autologous stromal vascular fraction (SVF) is an accepted therapeutic modality for degenerative conditions with 80% improvement and no serious treatment associated adverse events reported. Clinical translation of SVF therapy relies on confirmation of veterinary findings in targeted patient populations. Here we describe the rationale and preclinical data supporting the use of autologous SVF in treatment of RA, as well as provide 1, 3, 6, and 13 month safety outcomes in 13 RA patients treated with this approach.

PMID: 22313603 [PubMed – as supplied by publisher]

FULL TEXT: http://www.intarchmed.com/content/pdf/1755-7682-5-5.pdf

Ischemic Stroke Recovery May Be Improved Using Stem Cell Therapy

At the American Heart Association’s International Stroke Conference in New Orleans, two studies suggested that stem cell therapy improves functional recovery following subacute ischemic stroke and may aid in regenerative therapy.

One hundred and twenty subacute ischemic stroke patients were treated with mononuclear bone marrow-derived stem cells. Patients ranged in age from eighteen to seventy five years old. All were treated within seven to thirty days of suffering their strokes. Each patient was assessed using the Barthel index. The results showed that seventy three percent of patients who were treated with stem cells attained a Barthel score of greater than or equal to 60, which is the measure for assisted independence. Only sixty one percent of the patients who were not treated with stem cells achieved similar scores. All patients were tumor free at one year. This study was performed by Kameshwar Prasad, M.B.B.S., M.D., from the All India Institute of Medical Sciences in New Delhi.

In a separate study from the All India Institute of Medical Sciences in New Delhi, Rohit Bhatia, M.D. examined autologous mononuclear mesenchymal stem cell therapy in forty stroke patients who were recruited for the study from three months to one year after their strokes. Patients who were treated with stem cells showed significant improvement based on the Barthel index. No adverse reactions were observed. Dr. Bhatia concluded that intravenous administration of mononuclear and mesenchymal stem cells is safe, feasible and likely facilitates behavioral recovery following stroke.

Autologous mesenchymal stem cells for the treatment of secondary progressive multiple sclerosis: an open-label phase 2a proof-of-concept study

Connick P, Kolappan M, Crawley C, Webber DJ, Patani R, Michell AW, Du MQ, Luan SL, Altmann DR, Thompson AJ, Compston A, Scott MA, Miller DH, Chandran S.

Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.

Abstract

BACKGROUND:
More than half of patients with multiple sclerosis have progressive disease characterised by accumulating disability. The absence of treatments for progressive multiple sclerosis represents a major unmet clinical need. On the basis of evidence that mesenchymal stem cells have a beneficial effect in acute and chronic animal models of multiple sclerosis, we aimed to assess the safety and efficacy of these cells as a potential neuroprotective treatment for secondary progressive multiple sclerosis.

METHODS:
Patients with secondary progressive multiple sclerosis involving the visual pathways (expanded disability status score 5·5-6·5) were recruited from the East Anglia and north London regions of the UK. Participants received intravenous infusion of autologous bone-marrow-derived mesenchymal stem cells in this open-label study. Our primary objective was to assess feasibility and safety; we compared adverse events from up to 20 months before treatment until up to 10 months after the infusion. As a secondary objective, we chose efficacy outcomes to assess the anterior visual pathway as a model of wider disease. Masked endpoint analyses was used for electrophysiological and selected imaging outcomes. We used piecewise linear mixed models to assess the change in gradients over time at the point of intervention. This trial is registered with ClinicalTrials.gov, number NCT00395200.

FINDINGS:
We isolated, expanded, characterised, and administered mesenchymal stem cells in ten patients. The mean dose was 1·6×10(6) cells per kg bodyweight (range 1·1-2·0). One patient developed a transient rash shortly after treatment; two patients had self-limiting bacterial infections 3-4 weeks after treatment. We did not identify any serious adverse events. We noted improvement after treatment in visual acuity (difference in monthly rates of change -0·02 logMAR units, 95% CI -0·03 to -0·01; p=0·003) and visual evoked response latency (-1·33 ms, -2·44 to -0·21; p=0·020), with an increase in optic nerve area (difference in monthly rates of change 0·13 mm(2), 0·04 to 0·22; p=0·006). We did not identify any significant effects on colour vision, visual fields, macular volume, retinal nerve fibre layer thickness, or optic nerve magnetisation transfer ratio.

INTERPRETATION:
Autologous mesenchymal stem cells were safely given to patients with secondary progressive multiple sclerosis in our study. The evidence of structural, functional, and physiological improvement after treatment in some visual endpoints is suggestive of neuroprotection.

FUNDING:
Medical Research Council, Multiple Sclerosis Society of Great Britain and Northern Ireland, Evelyn Trust, NHS National Institute for Health Research, Cambridge and UCLH Biomedical Research Centres, Wellcome Trust, Raymond and Beverly Sackler Foundation, and Sir David and Isobel Walker Trust.

Fat Stem Cells Turn to Muscle: A Treatment for Muscular Dystrophy?

New research published in the journal Biomaterials by University of California, San Diego researcher Adam Engler suggests fat-derived stem cells that are developed on a stiff surface transform into mature muscle cells. This remarkable discovery could lead to new treatments for muscular dystrophy in the future.

Fat stem cells and bone marrow stem cells were grown on surfaces with different degrees of hardness ranging from very hard bone-like surfaces to very soft brain tissue-like surfaces.

The researchers found that the fat derived stem cells were much more likely (up to fifty times) to exhibit proteins that are essential to the cells becoming muscle tissue.
Yuk Suk Choi, a post-doc team member, says that the fat-derived stem cells seem to proliferate better than bone marrow cells when introduced to the hard surfaces. “They are actively feeling their environment soon, which allows them to interpret the signals from the interaction of cell and environment that guide development,” explained Choi.

Unlike bone marrow stem cells, stem cells from fat fused together to form myotubes. Although this phenomenon has been observed in the past, it has never been observed at such a high degree by Engler in the lab. Myotubes comprise an essential step in muscle formation.

Next, Engler and his team plan to observe how fused cells from fat perform in lab mice which are afflicted with a particular form of muscular dystrophy.

However, Dr. Engler cautioned, “From the perspective of translating this into a clinically viable therapy, we want to know what components of the environment provide the most important cues for these cells.”

Medistem Begins Phase II Clinical Trial for Heart Failure

Medistem Inc announced today treatment of 3 heart failure patients in the Non-Revascularizable IschEmic Cardiomyopathy treated with Retrograde COronary Sinus Venous DElivery of Cell TheRapy (RECOVER-ERC) trial. The trial is aimed at assessing safety and efficacy of the company’s Endometrial Regenerative Cell (ERC) stem cell product in 60 heart failure patients who have no available treatment options. The cells were discovered by Dr. Neil Riordan and the team at Medistem. The “Universal Donor” adult stem cells will be administered using a novel catheter-based retrograde administration methodology that directly implants cells in a simple, 30 minute, procedure.

“We are honored to have had the opportunity to present at the prestigious Cardiovascular Stem Cell Research Symposium, alongside companies such as Athersys, Aastrom, Pluristem, Cardio3, Cytori, and Mesoblast,” stated Thomas Ichim, CEO of Medistem. “The RECOVER-ERC trial is the first trial combining a novel stem cell, with a novel administration procedure. Today cardiac administration of stem cells is relatively invasive and can only be performed at specialized institutions, we feel the retrograde procedure will circumvent this hurdle.”

Medistem has been focusing on the endometrium because this is a unique tissue in that it undergoes approximately 500 cycles of highly vascularized tissue growth and regression within a tightly controlled manner in the lifetime of the average female. One of the first series of data describing stem cells in the endometrium came from Prianishnikov in 1978 who reported that three types of stem cells exist: estradiol-sensitive cells, estradiol- and progesterone-sensitive cells and progesterone-sensitive cells.

Interestingly, a study in 1982 demonstrated that cells in the endometrium destined to generate the decidual portion of the placenta are bone marrow derived, which prompted the speculation of a stem cell like cell in the endometrium. Further hinting at the possibility of stem cells in the endometrium were studies demonstrating expression of telomerase in endometrial tissue collected during the proliferative phase. One of the first reports of cloned stem cells from the endometrium was by Gargett’s group who identified clonogenic cells capable of generating stromal and epithelial cell colonies, however no differentiation into other tissues was reported. The phenotype of these cells was found to be CD90 positive and CD146 positive. The cells isolated by this group appear to be related to maintaining structural aspects of the endometrium but to date have not demonstrated therapeutic potential. In 2007, Meng et al, used the process of cloning rapidly proliferating adherence cells derived from menstrual blood and generated a homogenous cell population expressing CD9, CD29, CD41a, CD44, CD59, CD73, CD90, and CD105 and lacking CD14, CD34, CD45 and STRO-1 expression. Shortly after, Patel’s group reported a population of cells isolated using c-kit selection of menstrual blood mononuclear cells. The cells had a similar phenotype, proliferative capacity, and ability to be expanded for over 68 doublings without induction of karyotypic abnormalities. Interestingly both groups found expression of the pluripotency gene OCT-4 but not NANOG. More recent investigations have confirmed these initial findings. For example, Park et al demonstrated that endometrial cells are significantly more potent originating sources for dedifferentiation into inducible pluripotent cells as compared to other cell populations. Specifically, human endometrial cells displayed accelerated expression of endogenous NANOG and OCT4 during reprogramming compared with neonatal skin fibroblasts. Additionally, the reprogramming resulted in an average colony-forming iPS efficiency of 0.49 ± 0.10%, with a range from 0.31-0.66%, compared with the neonatal skin fibroblasts, resulting in an average efficiency of 0.03 ± 0.00% per transduction, with a range from 0.02-0.03%. Suggesting pluripotency within the endometrium compartment, another study demonstrated that purification of side population (eg rhodamine effluxing) cells from the endometrium results in a population of cells expressing transdifferentiation potential with a genetic signature similar to other types of somatic stem cells.

Given the possibility of ERC playing a key role in angiogenesis, Murphy et al utilized an aggressive hindlimb ischemia model combined with nerve excision in order to generate a model of limb ischemia resulting in limb loss. ERC administration was capable of reducing limb loss in all treated animals, whereas control animals suffered necrosis. In the same study, ERC were demonstrated to inhibit ongoing mixed lymphocyte reaction, stimulate production of the anti-inflammatory cytokine IL-4 and inhibit production of IFN-g and TNF-alpha. It is important to note that the animal model involved administration of human ERC into immunocompetent BALB/c mice. The relationship between angiogenesis and post myocardial infarct healing is well-known. Given previous work by Umezawa’s group demonstrating myocytic differentiation of ERC-like cells, administration of ERC into a model of post infarct cardiac injury was performed. Recovery was compared to bone marrow MSC. A superior rate of post-infarct recovery of ejection fraction, as well as reduction in fibrosis was observed with the ERC-like cells. Furthermore, it was demonstrated that the cells were capable of functionally integrating with existing cardiomyocytes and exerted effects through direct differentiation. The investigators also demonstrated in vitro generation of cardiomyocyte cells that had functional properties.

The RECOVER-ERC TRIAL that has begun will recruit 60 patients with congestive heart failure, which will be randomized into 3 groups of 20 patients each. Group 1 will receive 50 million ERC, Group 2 will receive 100 million and Group 3 will receive 200 million. Cells will be administered via catheter-based retrograde administration into the coronary sinus, a 30 minute procedure developed by Dr. Amit Patel’s Team. Each group will comprise of 15 patients receiving cells and 5 patients receiving placebo. Efficacy endpoints include ECHO and MRI analysis, which will be conducted at 6 months after treatment. The trial design is similar to the recent Mesoblast Phase II cardiac study, in order to enable comparison of efficacy.

Mechanism by Which Injured Tissue “Tells” Stem Cells to Leave Bone Marrow

Urao et al. Stem Cells. 2012 Jan 30.

In addition to the established role of bone marrow derived stem cells in producing blood cells, an interesting aspect of these stem cells is to assist/accelerate tissue healing after injury. Perhaps the most studied example of this is in the situation of myocardial infarction (heart attack), in which damaged heart muscle sends out signals to the bone marrow, which cause selective homing of bone marrow stem cells into the damaged heart tissue. This is believed to occur via activation of the transcription factor HIF-1 alpha due to lack of oxygen in the tissue. HIF-1 alpha binds to DNA and induces activation of a variety of genes that are involved in angiogenesis such as VEGF, FGF-2, and IL-20. Additionally, HIF-1 alpha stimulates production of the chemokine stromal derived factor (SDF)-1, which attracts bone marrow stem cells by binding to the CXCR4 receptor. The importance of SDF-1 in terms of bone marrow stem cell migration is exemplified in the situation of bone marrow transplantation. When a transplant is performed the bone marrow recipient is administered the donor stem cells intravenously and not intraosteolly (inside the bone). The reason for this is because the bone marrow itself constantly produces SDF-1 which attracts injected stem cells that express CXCR4.

During infarction, the concentration of SDF-1 produced by the damaged heart muscle is higher than the concentration of SDF-1 in the bone marrow, and as a result, stem cells from the bone marrow leave the bones, enter circulation, and home to the heart. Similar examples are found in the situation of stroke. In stroke patients, not only do bone marrow stem cells enter circulation after the stroke, but it has been reported that patients with higher number of stem cells in circulation actually have better outcomes.

The possibility of chemically “mobilizing” bone marrow stem cells into circulation is very attractive. On the one hand, it would be conceptually possible to augment the extent of regeneration by increasing the number of circulating stem cells, and on the other hand, it may be possible to perform “bone marrow transplantation” without the painful procedure of drilling holes through the bones of the donor. In fact, the second possibility is actually part of clinical practice. Doctors use the drug G-CSF, otherwise known as Neupogen, to cause donor migration of bone marrow stem cells into circulation, which are then harvested by leukopheresis, so that bone marrow puncture is not needed. The first possibility, the therapeutic use of bone marrow mobilization has resulted in mixed data. Some groups have demonstrated significant improvement in heart attack patients treated with G-CSF, whereas others have reported no benefit. Recently a new way of mobilizing stem cells has been approved by the FDA: a small molecule drug called Mozobil which blocks the interaction between SDF-1 and CXCR4. This drug was developed by the company Anormed and sold to Genzyme, a major Biopharmaceutical company.

In a recent paper, the role of oxidative stress was investigated in the animal model of critical limb ischemia. Critical limb ischemia is a condition in which patients experience poor circulation in the lower extremities, usually as a result of advanced peripheral artery disease. To replicate this condition in animals, the femoral artery which feeds the leg is ligated, and perfusion of the leg is measured, usually with Doppler ultrasound. In the mouse model there is a gradual recovery of blood flow as a result of spontaneous angiogenesis (new blood vessel formation). It is believed that bone marrow stem cells are involved in the formation of these new blood vessels.

While it is known that ischemia in the leg muscle is associated with recruitment of stem cells by production of SDF-1, little is known involving the changes that occur in the bone marrow as a result of ischemia in the leg.

Scientists demonstrated that after mice are subjected to hindlimb ischemia, there is a major increase in the production of free radicals in the bone marrow, specifically in the endosteal and central region of the bone marrow. Interestingly, these free radicals appear to be made by the enzyme Nox2 because mice lacking this enzyme do not have free radicals produced in the bone marrow as a result of leg ischemia. The enzyme appears to be expressed mainly in the Gr-1(+) myeloid suppressor cells that are found in the bone marrow. Free radicals were found to be associated with expression of HIF-1 alpha, implying occurrence of localized hypoxia. As can be expected, HIF-1 alpha expression was also found to associate with production of the angiogenic cytokine VEGF. It appeared that bone marrow VEGF expression was associated with expansion of bone marrow Lin(-) progenitor cell survival and expansion, leading to their mobilization into systemic circulation. It was furthermore demonstrated that ischemia of the leg increased expression of the proteolytic enzymes MT1-MMP and MMP-9 activity in the bone marrow, which did not occur in mice lacking Nox2.

The identification of NOX2 as being critical in the mobilization of bone marrow stem cells in response to ischemia suggests that antioxidants may actually modulate the extent of bone marrow stem cell mobilization. Conversely, if one believes the concept proposed, then oxidative stress (at least in a short term setting) would be beneficial towards mobilization. This is supported by studies showing that hyperbaric oxygen induces transient mobilization of bone marrow stem cells. For example Dhar et al. published (Equine peripheral blood-derived mesenchymal stem cells: Isolation, identification, trilineage differentiation and effect of hyperbaric oxygen treatment. Equine Vet J. 2012 Feb 15) that hyperbaric oxygen treatment in horses increased yield of mesenchymal stem cells collected from peripheral blood. Thom et al (Vasculogenic stem cell mobilization and wound recruitment in diabetic patients: increased cell number and intracellular regulatory protein content associated with hyperbaric oxygen therapy. Wound Repair Regen. 2011 Mar-Apr;19(2):149-61) reported 2-fold increases in hematopoietic stem cells (identified by CD34 expression) in diabetic patients who received hyperbaric oxygen. This study also demonstrated that the CD34 cells that were found in circulation contained high expression of HIF-1 alpha, implying that they may possess angiogenic activity. An interesting experiment would have been if they removed the cells and assessed in vitro angiogenic activity. Indeed it is known that in patients with diabetes the CD34 cells possess a reduced angiogenic activity. If hyperbaric oxygen stimulates this angiogenic activity, it may be a relatively non-invasive method of augmenting the “rejuvenation” potential of the patient’s own stem cells. Another interesting finding of the study was that hyperbaric oxygen was associated with an increase in nitric oxide production by platelets. Since nitric oxide can act as an anticoagulant, this may be another benefit of using hyperbaric oxygen.

One important question is the potency of the stem cell mobilization induced by hyperbaric oxygen. Specifically, while it is nice that an increase in CD34 cells is observed, what activity do these cells actually have ? An earlier study by Thom et al (Stem Cell Mobilization by Hyperbaric Oxygen. Am J Physiol Heart Circ Physiol. 2006 Apr;290(4):H1378-86) demonstrated that the colony-forming ability of the mobilized cells was actually 16-20 fold higher compared to controls. Colony-forming ability is an assessment of the stem cells to generate new cells in vitro.

Thus the paper we discussed sheds some interesting light on the connection between “oxidative medicine” and stem cell biology. Obviously more studies are needed before specific medical recommendations can be made, however, given the large number of patients being treated with alternative medicine techniques such as hyperbaric oxygen, one must ask whether other treatments of this nature also affect stem cells. For example, what about ozone therapy? Or intravenous ascorbic acid?