What to know before getting stem cells
Dr. John Hughes, DO
Aspen Integrative Medicine
July 6th, 2017
Disclaimer:
I have no material interest or investment in any stem cell companies or products.
- I. Introduction to stem cells
- II. Mesenchymal stem cells
- III. Pluripotent stem cells
- IV. Making a stem cell decision
Embryonic Stem Cells
- Derived from the fetus
- Requires special regulatory approval
- Mostly used for research purposes
- Not readily available
- Expensive
- Not autologous
Adult Stem Cells
- Derived from bone, adipose, or blood
- Requires physician expertise and quality control
- Mostly used for regenerative and cosmetic purposes
- Readily available
- Less expensive
- Autologous use is permitted in US
Totipotent Stem Cells
- Derived from the embryo
- Forms all cell types in the body
- Used for early embryonic development
- “Baby cells” (from a zygote) that becomes a pluripotent cell
Pluripotent Stem Cells
- Derived from the embryo or blood
- Forms all cell types in the body except the embryo or the placenta
- Does not have a specialized trajectory of development
- “Youthful cell” with great ability to differentiate into other cell types
Multipotent Stem Cells
- Derived from cord blood, blood, bone marrow, fat and muscle
- Forms only cell types from the mesoderm
- Has a development trajectory towards a specific type of cell
- “Teenage cell” already differentiated into it’s target adult cell type
Mesenchymal Stem Cells (MSCs)
Discovery
- Alexander Friedenstein discovered mesenchymal stem cells in mice (Mus musculus).
- From 1966 through 1987, Friedenstein provided evidence that stem cells from bone marrow can differentiate into mesenchymal tissues
- Since then, the cell potency of mesenchymal stem cells differentiation has been a cause of debate
- Are they truly multipotent or unipotent?
https://embryo.asu.edu/pages/mesenchyme
Defined
- Mesenchyme: loose cells embedded in the extracellular matrix
- a mesh of proteins and fluid that allows cells to migrate easily
- Directs development of morphological structures during the embryonic and fetal stages
- connective tissues, bones, cartilage, lymphatic and circulatory systems
- Carry over 480 growth factors and are attracted to target tissues of inflammation
- Primarily isolated from fat or bone marrow through a time-insensitive, invasive process
- Human fat (adipose tissue) has about 10x more stem cells than bone marrow
https://embryo.asu.edu/pages/mesenchyme
How They Work
- Derived from pluripotent stem cells, have already partially differentiated, and they continue specializing as they develop
- Must be activated appropriately – often mixed with human plasma
- Considered multipotent because their specialization potential is limited to one or more cell lines
- Current research suggests multipotent cells are able to go beyond the boundaries of producing one specific cell type but do so infrequently and only under narrow conditions
http://www.explorestemcells.co.uk/multipotentstemcells.html
- Modulate endogenous tissue and immune cells
- Actively interact with nearby cells
- Observed benefits of MSC therapy may result from the relinquishment of their molecular contents upon administration
- Therapeutic effects are short-lived
- “Recent studies have suggested that less than 1% of systemically administered MSCs persist for longer than a week following injection.”
- Limited in numbers – unlikely that true MSCs circulate peripherally (~0.01% of mononuclear bone marrow cells)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3759519/
Clinical Indications
- Allogenic bone marrow transplants (from the same species to another of the same species) clinically used since the 1980s
- Autologous fat and bone marrow transplantations (from the same individual back to same individual) can be used to support target tissues that are not from the same cell type
- E.g., injecting fat MSCs into joints orthopedically to support the growth of new cartilage
- These MSC’s do not develop into new cartilage cells – they provide growth factors, reduction in inflammation, and immune modulation that may support joint health
- They are already on a development trajectory and their effects on unique target tissues are mostly paracrine (effecting nearby cells)
- Outside the US, MSCs can be cultured for several weeks to build up the cell counts
- The idea is that with more MSCs, more target tissues will benefit
- Challenge: they grow older the more times that they replicate so they are less effective
- MSCs are generally best used for transplantation into similar tissues from which they derive
- E.g., MSCs from fat are best transplanted into areas in need of fat replacement
- (breast augmentation, subcutaneous fat areas of the body – facial, lip, buttocks transplants)
- Most effective clinical use of MSCs:
- Same tissue transplantation (bone marrow to bone marrow, fat to fat)
- Joint conditions (if related to an autoimmune or systemic inflammation)
- Autoimmune disorders and systemic inflammatory conditions (see table on next slide)
Dangers and Side Effects
- Harvesting of bone marrow and fat MSCs is unpleasant for the patient
- There is a limited number of times one can extract and use fat MSCs
- Many patients have to repeat the procedure to gain significant benefit
- MSCs reduce inflammation for a time period of 6 months to 2 years but have limited regenerative benefits
- Are generally designed to affect one germ layer and tissues derived from that mesodermal layer – and under most conditions are unipotent (have the capacity to differentiate into only one cell type)
- Because of the immunomodulatory effects of these MSCs, they predispose the patients more infections or even cancer
- After MSC infusions were used to treat nine patients suffering from GvHD, three developed viral infections
- Immunosuppression by the MSCs had caused a reduction of immuno-surveillance to viruses
https://www.ncbi.nlm.nih.gov/pubmed/16604097
- MSCs, when administered in rats, can engraft in the renal tubules and mal-differentiate into adipocytes that hinder normal function of the kidney and lead to chronic kidney disease
https://www.ncbi.nlm.nih.gov/pubmed/17460140
Pluripotent Stem Cells
Discovery
- Henry Young et al. (2004) demonstrated connective tissue (including blood) contains reserve precursor cells
- Reserve precursor cells consist of: tissue-specific progenitor cells, germ-layer lineage stem cells, and pluripotent stem cells
- Tissue-specific progenitor cells can be unipotent or multipotent
- Progenitor cells can only double 50–70 times while germ-layer lineage stem cells and pluripotent stem cells have a much greater lifespan
- Pluripotent stem cells were thought only to exist in embryonic stem cells until Dr. Young’s discovery of them in the peripheral blood in the late 20th century
Defined
- Precursor cells can be
- Tissue-specific progenitor cells
- Lineage-committed (ectodermal, mesodermal, and endodermal) germ-layer lineage stem cells
- Lineage-uncommitted pluripotent epiblastic-like stem cells
- What we are interested in today are the lineage uncommitted pluripotent stem cells (some researchers call these cells, blastomere-like stem cells)
https://mail.google.com/mail/u/0/#search/henry+young+/13b421977b3e5c33?projector=1
How They Work
- Understanding lineage uncommitted pluripotent stem cells requires an understanding of the germ layers
- Adult pluripotent stem cells can be induced to form cells from the three primary germ-layer lineages (i.e., ectoderm, mesoderm, and endoderm).
- Results from neuronal, hematopoietic, diabetic, chondrogenic, osteogenic, myogenic, and cardiogenic studies demonstrate that adult pluripotent stem cells can be induced to undergo directed lineage induction.
- The activation of quiescent precursor cells is a potential component of tissue restoration.
- Quiescent stem cells also assist the tissue-committed progenitor cells in forming the missing tissues
- Originate in bone marrow and present in peripheral blood
- Contain a unique marker that can be used to select them for both diagnostic and therapeutic procedures
- In abundance in peripheral blood and in reproductive tissue secretions
Clinical Indications
- Lineage uncommitted pluripotent stem cells can be used to form any tissues in the endoderm, mesoderm, or ectoderm
- Treatment of a wide range of degenerative diseases in both humans and animals including, but not limited to:
- Diabetes, osteoarthritis, osteoporosis and Alzheimer’s disease, to name a few, as well as regenerative applications associated with aging
- TBI studies: When used in conjunction with hyperbaric oxygen therapy, intranasal and IV pluripotent stem cells (derived from blood plasma), after activation, have been shown, in case studies, to positively address post-concussive symptoms secondary to TBI: memory, sleep, mental fatigue, mental clarity, libido, motor function and balance.
- Could be shown useful in replacing bone marrow in post-cancer treatment
Making a stem cell decision
- Bone Marrow
- Cost: $3,000 – $10,000
- Recovery time: One Month
- Adipose (Fat)
- Cost: $6,000 – $15,000
- Recovery time: One Month
- Blood Based
- Cost: $3,500 – $4,000
- Recovery time: Less than a week
References
Cell Applications. https://www.cellapplications.com/stem-0
Cellular Differentiation. http://oerpub.github.io/epubjs-demo-book/content/m46036.xhtml
Kunter, U., Rong, S., Boor, P., Eitner, F., Müller-Newen, G., Djuric, Z., … & Milovanceva-Popovska, M. (2007). Mesenchymal stem cells prevent progressive experimental renal failure but maldifferentiate into glomerular adipocytes. Journal of the American Society of Nephrology, 18(6), 1754-1764.
MacCord, K. (2012). Mesenchyme. The Embryo Project Encyclopedia. Retrieved from https://embryo.asu.edu/pages/mesenchyme
Mesenchymal Stem Cell Reagents. Retrieved from http://www.sigmaaldrich.com/life-science/cell-biology/cell-biology-products.html?TablePage=22692887
Murnaghan, I. (2016). Multipotent stem cells. Explore Stem Cells. Retrieved from http://www.explorestemcells.co.uk/multipotentstemcells.html
Parekkadan B, Milwid JM. Mesenchymal Stem Cells as Therapeutics. Annual review of biomedical engineering. 2010;12:87-117. doi:10.1146/annurev-bioeng-070909-105309.
Stout, C. L., Ashley, D. W., Morgan, J. H., Long, G. F., Collins, J. A., Limnios, J. I., … & Young, H. E. (2007). Primitive stem cells residing in the skeletal muscle of adult pigs are mobilized into the peripheral blood after trauma. The American Surgeon, 73(11), 1106-1110.
Sundin, M., Örvell, C., Rasmusson, I., Sundberg, B., Ringden, O., & Le Blanc, K. (2006). Mesenchymal stem cells are susceptible to human herpesviruses, but viral DNA cannot be detected in the healthy seropositive individual. Bone marrow transplantation, 37(11), 1051-1059.
Tithon Biotech (n.d.). Minutevideo retrieved from http://mv.pac.io/post/55b2e2b41e1818650cc7b872
Tithon Human Sciences (2015). Peripheral blood derived pluripotent stem cell technology. Rhttp://aspenintegrativemedicine.com/wp-content/uploads/Tithon-Human-Sciences-Ortho-Case-Study.pdf
Young, H. E., Duplaa, C., Romero-Ramos, M., Chesselet, M. F., Vourc’h, P., Yost, M. J., … & Tamura-Ninomiya, S. (2004). Adult reserve stem cells and their potential for tissue engineering. Cell biochemistry and biophysics, 40(1), 1-80.
Young, H. E., & Black, A. C. (2004). Adult stem cells. The Anatomical Record Part A: Discoveries in Molecular, Cellular, and Evolutionary Biology, 276(1), 75-102.