Power Point presentation of recent advances in neurosurgery in stem cell therapy

1. Stem Cells in Neurosurgery
Dr Fakir Mohan Sahu
MCh Neurosurgery
AIIMS Bhubaneswar
Date: 18/03/2020

2. Introduction
The Fundamental axiom of neuroscience
“the adult human brain, in contrast to other organs such as skin and liver, lacked the capacity for
self repair and regeneration.”
No longer considered true……….

3. Outline
1. What is Stem cell?
2. Controversy in Adult Neurogenesis
3. Types of stem cells
4. Stem cell therapy in neurosurgery (TBI, SCI, PNI, Brain tumour, Stroke)
5. Methods of stem cell implantation
6. Problems in use of Neural Stem Cells (NSCs)
7. Stem cell: Ethics, Laws and Policy
8. Current and Future Prospects of stem cells

4. Stem cell
• Undifferentiated or partially differentiated cell
• Can differentiate into various types of cells
• Divide indefinitely (more of the same stem cell)
• Properties: Unspecialized, Self renewal, Multipotency

5. How its different from Progenitors cells
• Found in adult organisms
• Act as a repair system for the body and replenish special cells
( blood, skin and intestinal tissues)
Stem Cell Progenitor Cell
Self-renewal in vitro Unlimited Limited
Potentiality Multipotent
Unipotent,
sometimes
oligopotent
Maintenance of self-
renewal
Yes No
Population
Reaches maximum
number of cells
before differentiating
Does not reach
maximum population

6. Neuronal Stem Cells(NSCs)
• Undifferentiated cells that have the
ability of self-renewal, proliferate
and potentiality to differentiate into
• Neurons,
• Astrocytes,
• Oligodendrocytes in the CNS
Loeffler M, Potten CS: Stem cells and cellular pedigrees-a conceptual introduction. In: Potten CS, ed, Stem Cells,
London, Academic Press, 1997; 1–28

7. Controversy of Adult Neurogenesis

8. Neurogenesis in Human Adult Brain
• Adult human Sub-Ventricular Zone (SVZ) of Lateral
Ventricle contains NSCs
SVZ specific-62.57+/-7.46 neurosphere/well
Purified SVZ Astrocyte-109.29+/-8.57 neurosphere/well
Cortex and Striatum no neurosphere
(Sanai et al , Nature , 2004)
• Sub-granular layer of the dentate gyrus of the
Hippocampus, Olfactory bulb (Gage, 2000)
a. Dense ribbon of SVZ astrocytes seen lateral wall of the human ventricles. b, Coronal section (6 mm) stained with
the nuclear marker DAPI reveals a region of high cellularity that is separated from the ependyma by a gap. c,
Vibratome section showing GFAP expression of SVZ astrocyte ribbon and GFAP-positive fibre bundles filling the
subependymal gap. d, Panoramic electron micrograph of a postmortem adult human SVZ, showing the ependymal
lining, gap region and astrocyte ribbon.

9. Type of Stem cells
• Defined by two main properties: self-
renewal and multipotency
Stem cells
Embryonic
Blastocyst inner cell
mass
Fetal
fetal blood
and tissues
Adult

10. Embryonic Stem cells
• Cells derived from the inner cell mass of the embryonic blastula
• Ability to differentiate
• Can be propagated indefinitely in culture
• Lack of contact inhibition
• Atypical cell cycle regulation
• Characteristic set of markers
• Form Teratocarcinomas in nude mice

11. Foetal Stem Cells
• Earliest cells found in the fetus
• The "building block" cells of blood, tissue and organs
• Umbilical cord blood is a rich source
• Other sources
Amnion/placenta
Umbilical cord veins
Umbilical cord matrix cells

12. Adult Stem cells
• Potential source of Autologous cells
• For transplantation therapies (eliminates immunological
complications)
• First recognized in the hematopoietic system-Bone Marrow
Transplantation
(BMT)

13. Induced Pluripotent Neuronal Stem Cell(iPNSC)
• Types of pluripotent stem cell
• Artificially derived from a non-pluripotent cell,
(Adult Somatic Cell)
• Inducing a "forced" expression of certain
genes.
• First produced in 2006 (Mouse cells)
in 2007 (Human cells).
(Yu J, Vodyanik MA, et al. | Induced Pluripotent Stem Cell Lines
Derived from Human Somatic Cells | Science
DOI:10.1126/science.1151526)
Yamanaka factors
Oct3/4 - Octamer-binding transcription factor 3/4
Sox2 - Sry-related HMG-box gene 2
Klf4 - Kruppel-like factor 4
c-Myc - MYC protooncogene

14. Stem cells in Traumatic Brain injury(TBI)
• Mammalian adult brain is site of proven neurogenesis in response to
ageing or mechanical injury
(X. Wang, P. Seekaew, X. Gao, J. Chen, Traumatic brain injury stimulates neural stem cell proliferation via mammalian target of
rapamycin signaling pathway activation, ENeuro 3 (2016).
• Post-traumatic neurogenesis and brain remodeling attributable to the
persistence of NSCs into adulthood.
• Mainly sustained by new Astrocytes
(S.G. Kernie, J.M. Parent, Forebrain neurogenesis after focal Ischemic and traumatic brain injury, Neurobiol. Dis. 37 (2010) 267–274.)

15. Preclinical studies in TBI
• More than 10 different types of stem cells employed in previous TBI
studies
• Bone marrow and Umbilical cord mesenchymal stem cells
• Neurological deficits were improved (Acute phase of TBI)
• Mechanism - secretion neurotropic factors and reduction of
inflammation

17. STEM CELLS IN SPINAL CORD
INJURY(SCI)• Endogenous and spontaneous neurogenesis supported by astrocytes
and oligodendrocytes has been demonstrated after acute spinal cord
injury
• They affect the posttraumatic cord microenvironment through the
secretion of a set of bioactive molecules, acting both paracrine and
autocrinally to suppress local immune response, enhance angiogenesis,
and inhibit scarring and cell death.
• Rresponsible for axon remyelination, sprouting and for addressing them
toward their targets, as well as for the formation of functional bridges
(H. Yang et al Endogenous neurogenesis replaces oligodendrocytes and astrocytes after primate
spinal cord injury, J. Neuroscience 26 (2006) 2157–2166.)

21. Administration route and location of injection
• Intravenous,
• Intrathecal
• Intra medullary- most effective
• Proxymal to site of injury- stem cell survival better but number that
can be injected is less to avoid deficit.
• At site of injury- hostile to stem cell but larger volume can be injected
and good for resolution of glial scar and bridging for axonal regeneration

22. Timing of stem cells transplantation
• Acute phase- first 3 days –hypoxia, reactive oxygen free radical,
excitatory transmitters, and inflammatory molecules.
• Subacute phase 4th day – 12 months – optimal
• Chronic phase after 12 months -glial scar tissue acts as a physical
barrier, reduced trophic factors
• Spontaneous neurological recovery rise
rapidly during the first 3 months and plateaued at 12 months after
SCI
(B.C. Gabel, E.I. Curtis, M. Marsala, J.D. Ciacci, A review of stem cell therapy for spinal cord injury: large animal
models and the frontier in humans, World Neurosurg. 98 (2017) 438–443.)

23. Stem cells in Peripheral nerve injury
• Capacity for regeneration in peripheral nerve is higher than that of
the CNS
• Even then, complete recovery is fairly infrequent, misdirected, or
associated with debilitating neuropathic pain.
• Direct microinjection, suspension within artificial tubes and seeding
within devitalized muscle or nerve grafts
(Mosahebi A, Woodward B, Wiberg M, et al: Retroviral labeling of Schwann cells: in vitro characterization and
in vivo transplantation to improve peripheral nerve regeneration. Glia34:8-17, 2001)

24. Possible sources for Peripheral nerve
repair• Embryonic neural stem cells
• Bone marrow cells
• Adipose tissue
• The skin and its associated structures
• Effect of bone marrow-derived mononuclear cells on nerve
regeneration in the transection model of the rat sciatic
nerve.
(Journal of Clinical Neuroscience, Volume 16, Issue 9, September 2009, Pages 1211-1217 Rohit Kumar Goel,
Vaishali Suri, Ashish Suri, Chitra Sarkar, Sujata Mohanty, Meher Chand Sharma, Pradeep Kumar Yadav, Arti

25. Stem cell in Stroke
• Stroke is the leading cause of death
and disability and new field for SCT
• An approach to functional repair
would be replacing the damaged
tissue with new cells.

26. Stem cell in Brain tumours
• Malignant gliomas represent a
significant challenge for stem cells
therapy.
• One promising method-neural stem cells
(NSCs)
• NSCs may elaborate certain factors, such as
the transforming growth one (TGF-β),
therefore acting as antagonists toward tumor
growth.
(K. Staflin, G. Honeth, S. Kalliom€aki, C. Kjellman, K. Edvardsen, M. Lindvall,
Neural progenitor cell lines inhibit rat tumor growth in vivo, Cancer Res. 64 (2004)
5347–5354.)

27. Stem cells in Brain Tumour
• NSC tk cells; transduced with the thymidine kinase gene from herpes simplex
virus (HSV).
• Upon systemic ganciclovir (GCV) administration, the thymidine kinase gene
converts the non-toxic prodrug (GCV) into a toxic molecule (GCV
monophosphate), leading to tumour cell death.
• Property of tumor tropism can be exploited to target malignant glioma.
• TNF-related apoptosis-inducing ligand (TRAIL), has been shown to
induce apoptosis selectively in malignant glial cells while sparing normal
tissue.
(esham M, Kabos P, Gutierrez MA, et al. Induction of glioblastoma apoptosis using neural stem
cellmediated delivery of tumor necrosis factor-related apoptosis-inducing ligand. Cancer Res
2002;62:7170–4.)

28. Methods of stem cell implantation
• Stem cell implantation using brain stereotactic surgery
• Direct injection to the injury site
• Subarachnoid stem cell implantation via lumbar puncture
• Intravenous transplantation
• Intranasal cell delivery
Mechanism
• Replacement of damage neuros
• Re-myelination
• Neuroprotection
• Favorable microenvironment
• Restoration of blood flow by angiogenesis

29. Problems with use of neural stem cells
• Use of allogeneic cells would necessitate immunosuppressive therapy
• The potential tumorigenicity of transplanted NSCs
• Optimum donor source
• The manner of storage
• Duration of storage or culture in medium
• The minimally required number of cells for transplantation
• Viability of transplanted cells
• Conditions of the host- age of patient and severity of disease
• Detection of the most appropriate site for transplant
• Logistic and ethical problems

30. Stem Cells : Ethics, Law, and
Policy• Ethics and policy debates centered on the moral status of the
embryo – weather the 2- to 4 days old blastocyst is a person.
• Each country has different moral and regulatory frameworks—one
permissive, one restrictive.
• Investigators and sponsors should present review committees with
a clear and thoughtful research plan that will satisfy requirements
to “do no harm.”
• Ethicists and non-specialists should take time to familiarize
themselves with the basics of stem cell biology and the predictive
power of animal models

31. Indian Scenario
• ICMR and Department of Biotechnology has come up with
“Guidelines for stem cell research and therapy "in 2007.
• These guidelines address both ethical and scientific concerns
• To review and monitor stem cell research
National Apex Committee for Stem Cell Research and Therapy (NAC-SCRT)
Institutional Committee for Stem Cell Research and Therapy (ICSCRT) formed.

32. Current and Future prospects of
NSCs• No approved indication for stem cell therapy as a part of routine
medical practice, other than Bone Marrow Transplantation (BMT)
• Prior permission from the regulatory body.
Future strategies
To enhance stem cell survival and axonal regeneration-
-Fibrin scaffold to hold the stem cells
-Pre differentiation of stem cells in vitro
-Guidance channels for the stem cells
-Cyclic-AMP to enhance production of neurons from the stem
cells

33. Conclusion
• Stem cells have been shown to produce positive therapeutic effects in
animal models and in a few human trials. However, the exact mechanism of
this positive effect is as yet unclear.
• Preclinical and clinical trials have shown promising results in
Neurodegenerative disorders.
• Promising but more work still is needed for stem cell strategies.
• Technological advances are needed
• to make precise genetic modifications of stem cells or their progeny
• to enhance their capacity for migration, integration and pathway reconstruction.
• Populations Cells within tumours behave like stem cells.

34. THANK YOU