joe wright portsmouth college stem cells portsmouth college science department

Joe WrightPortsmouth College

Stem Cells

Portsmouth CollegePortsmouth CollegeScience DepartmentScience Department


Learning Outcomes

• Explain what is meant by stem cells, pleuripotency and totipotency

• Discuss the moral, ethical and spiritual implications of stem cell research


Question

• How many different types of cell are there in the human body?


Epidermal keratinocyte (differentiating epidermal cell) Epidermal basal cell (stem cell) Keratinocyte of fingernails and toenails Nail bed basal cell (stem cell) Medullary hair shaft cell Cortical hair shaft cell Cuticular hair shaft cell Cuticular hair root heath cell Hair root sheath cell of Huxley's layer Hair root sheath cell of Henle's layer External hair root sheath cell Hair matrix cell (stem cell) Surface epithelial cell of stratified squamous epithelium of cornea, tongue, oral cavity, esophagus, anal canal, distal urethra and vagina basal cell (stem cell) of epithelia of cornea, tongue, oral cavity, esophagus, anal canal, distal urethra and vagina Urinary epithelium cell (lining urinary bladder and urinary ducts) Salivary gland mucous cell (polysaccharide-rich secretion) Salivary gland serous cell (glycoprotein enzyme-rich secretion) Von Ebner's gland cell in tongue (washes taste buds) Mammary gland cell (milk secretion) Lacrimal gland cell (tear secretion) Ceruminous gland cell in ear (wax secretion) Eccrine sweat gland dark cell (glycoprotein secretion) Eccrine sweat gland clear cell (small molecule secretion) Apocrine sweat gland cell (odoriferous secretion, sex-hormone sensitive) Gland of Moll cell in eyelid (specialized sweat gland) Sebaceous gland cell (lipid-rich sebum secretion) Bowman's gland cell in nose (washes olfactory epithelium) Brunner's gland cell in duodenum (enzymes and alkaline mucus) Seminal vesicle cell (secretes seminal fluid components, including fructose for swimming sperm) Prostate gland cell (secretes seminal fluid components) Bulbourethral gland cell (mucus secretion) Bartholin's gland cell (vaginal lubricant secretion) Gland of Littre cell (mucus secretion) Uterus endometrium cell (carbohydrate secretion) Isolated goblet cell of respiratory and digestive tracts (mucus secretion) Stomach lining mucous cell (mucus secretion) Gastric gland zymogenic cell (pepsinogen secretion) Gastric gland oxyntic cell (hydrochloric acid secretion) Pancreatic acinar cell (bicarbonate and digestive enzyme secretion) Paneth cell of small intestine (lysozyme secretion) Type II pneumocyte of lung (surfactant secretion) Clara cell of lung Anterior pituitary cells Somatotropes Lactotropes Thyrotropes Gonadotropes Corticotropes Intermediate pituitary cell, secreting melanocyte-stimulating hormone Magnocellular neurosecretory cells secreting oxytocin secreting vasopressin Gut and respiratory tract cells secreting serotonin secreting endorphin secreting somatostatin secreting gastrin secreting secretin secreting cholecystokinin secreting insulin secreting glucagon secreting bombesin Thyroid gland cells thyroid epithelial cell parafollicular cell Parathyroid gland cells Parathyroid chief cell oxyphil cell Adrenal gland cells chromaffin cells secreting steroid hormones (mineralcorticoids and gluco corticoids) Leydig cell of testes secreting testosterone Theca interna cell of ovarian follicle secreting estrogen Corpus luteum cell of ruptured ovarian follicle secreting progesterone Kidney juxtaglomerular apparatus cell (renin secretion) Macula densa cell of kidney Peripolar cell of kidney Mesangial cell of kidney Intestinal brush border cell (with microvilli) Exocrine gland striated duct cell Gall bladder epithelial cell Kidney proximal tubule brush border cell Kidney distal tubule cell Ductulus efferens nonciliated cell Epididymal principal cell Epididymal basal cell Hepatocyte (liver cell) White fat cell Brown fat cell Liver lipocyte Type I pneumocyte (lining air space of lung) Pancreatic duct cell (centroacinar cell) Nonstriated duct cell (of sweat gland, salivary gland, mammary gland, etc.) Kidney glomerulus parietal cell Kidney glomerulus podocyte Loop of Henle thin segment cell (in kidney) Kidney collecting duct cell Duct cell (of seminal vesicle, prostate gland, etc.) Blood vessel and lymphatic vascular endothelial fenestrated cell Blood vessel and lymphatic vascular endothelial continuous cell Blood vessel and lymphatic vascular endothelial splenic cell Synovial cell (lining joint cavities, hyaluronic acid secretion) Serosal cell (lining peritoneal, pleural, and pericardial cavities) Squamous cell (lining perilymphatic space of ear) Squamous cell (lining endolymphatic space of ear) Columnar cell of endolymphatic sac with microvilli (lining endolymphatic space of ear) Columnar cell of endolymphatic sac without microvilli (lining endolymphatic space of ear) Dark cell (lining endolymphatic space of ear) Vestibular membrane cell (lining endolymphatic space of ear) Stria vascularis basal cell (lining endolymphatic space of ear) Stria vascularis marginal cell (lining endolymphatic space of ear) Cell of Claudius (lining endolymphatic space of ear) Cell of Boettcher (lining endolymphatic space of ear) Choroid plexus cell (cerebrospinal fluid secretion) Pia-arachnoid squamous cell Pigmented ciliary epithelium cell of eye Nonpigmented ciliary epithelium cell of eye Corneal endothelial cell Respiratory tract ciliated cell Oviduct ciliated cell (in female) Uterine endometrial ciliated cell (in female) Rete testis cilated cell (in male) Ductulus efferens ciliated cell (in male) Ciliated ependymal cell of central nervous system lining brain cavities) Ameloblast epithelial cell (tooth enamel secretion) Planum semilunatum epithelial cell of vestibular apparatus of ear (proteoglycan secretion) Organ of Corti interdental epithelial cell (secreting tectorial membrane covering hair cells) Loose connective tissue fibroblasts Corneal fibroblasts Tendon fibroblasts Bone marrow reticular tissue fibroblasts Other nonepithelial fibroblasts Pericyte Nucleus pulposus cell of intervertebral disc Cementoblast/cementocyte (tooth root bonelike ementum secretion) Odontoblast/odontocyte (tooth dentin secretion) Hyaline cartilage chondrocyte Fibrocartilage chondrocyte Elastic cartilage chondrocyte Osteoblast/osteocyte Osteoprogenitor cell (stem cell of osteoblasts) Hyalocyte of vitreous body of eye Stellate cell of perilymphatic space of ear Red skeletal muscle cell (slow) White skeletal muscle cell (fast) Intermediate skeletal muscle cell nuclear bag cell of Muscle spindle nuclear chain cell of Muscle spindle Satellite cell (stem cell) Ordinary heart muscle cell Nodal heart muscle cell Purkinje fiber cell Smooth muscle cell (various types) Myoepithelial cell of iris Myoepithelial cell of exocrine glands Red Blood Cell Erythrocyte (red blood cell) Megakaryocyte (platelet recursor) Monocyte Connective tissue macrophage (various types) Epidermal Langerhans cell Osteoclast (in bone) Dendritic cell (in lymphoid tissues) Microglial cell (in central nervous system) Neutrophil granulocyte Eosinophil granulocyte Basophil granulocyte Mast cell Helper T cell Suppressor T cell Cytotoxic T cell B cells Natural killer cell Reticulocyte Stem cells and committed progenitors for the blood and immune system (various types) Auditory inner hair cell of organ of Corti Auditory outer hair cell of organ of Corti Basal cell of olfactory epithelium (stem cell for olfactory neurons) Cold-sensitive primary sensory neurons Heat-sensitive primary sensory neurons Merkel cell of epidermis (touch sensor) Olfactory receptor neuron Pain-sensitive primary sensory neurons (various types) Photoreceptor rod cell of eye Photoreceptor blue-sensitive cone cell of eye Photoreceptor green-sensitive cone cell of eye Photoreceptor red-sensitive cone cell of eye Proprioceptive primary sensory neurons (various types) Touch-sensitive primary sensory neurons (various types) Type I carotid body cell (blood pH sensor) Type II carotid body cell (blood pH sensor) Type I hair cell of vestibular apparatus of ear (acceleration and gravity) Type II hair cell of vestibular apparatus of ear (acceleration and gravity) Type I taste bud cell Cholinergic neural cell (various types) Adrenergic neural cell (various types) Peptidergic neural cell (various types) Inner pillar cell of organ of Corti Outer pillar cell of organ of Corti Inner phalangeal cell of organ of Corti Outer phalangeal cell of organ of Corti Border cell of organ of Corti Hensen cell of organ of Corti Vestibular apparatus supporting cell Type I taste bud supporting cell Olfactory epithelium supporting cell Schwann cell Satellite cell (encapsulating peripheral nerve cell bodies) Enteric glial cell Astrocyte (various types) Neuron cells (large variety of types, still poorly classified) Oligodendrocyte Spindle neuron Anterior lens epithelial cell Crystallin-containing lens fiber cell karan cellsMelanocyte Retinal pigmented pithelial cell Oogonium/Oocyte Spermatid Spermatocyte Spermatogonium cell (stem cell for spermatocyte) Spermatozoon Ovarian follicle cell Sertoli cell (in testis) Thymus epithelial cell


Introduction

• After fertilisation a ZYGOTE is formed• A series of rapid cell divisions (CLEAVAGE)

follows• Smaller cells are produced after each division

http://creative.gettyimages.com/source/film/FilmPlayer.aspx?clipID=703-37&brandID=6&Type=Clip&QT=1&width=720&height=604


Cells in the Early Embryo

• After a zygote has undergone 3 cycles it has 8 identical cells.

• Any of these cells can develop into a complete human (e.g. identical twins)

• These cells are called TOTIPOTENT

An 8 Cell Human Embryo

(Day 3)


5 Days after Conception

BLASTOCYST

Outer layer

forms the placenta

Inner cell mass goes on to form

the tissues of developing

embryo. Cells referred to as

PLURIPOTENT EMBRYONIC STEM CELLS


Differentiated Cells

• As embryo develops cells become specific types of cell (DIFFERENTIATED)

• Some cells even in adults can turn into a limited number of cells e.g. neural stem cells & white blood stem cells.

• These cells are called MULTIPOTENT


Medical Uses of Stem Cells

• Adult stem cells have been used for over 30 years to treat….

• Leukaemia & Lymphoma


Potential use of Stem Cells

• Parkinson’s Disease• Brain Damage • Cancer • Spinal cord injury • Muscle damage • Heart damage• Arthritis• Osteoporosis

• Low blood supply • Baldness • Missing teeth • Deafness • Blindness and

Vision Impairment • ALS (Lou Gehrig's

Disease)

A Universal Human Donor Cell


Where to get Stem Cells

• Pluripotent cells isolated from ‘spare embryos’ from IVF treatment

• Embryos allowed to grow to form blastocysts

• Stem cells isolated, then cultured to hopefully develop into tissues

• Rest of embryo discarded


Ethical Concerns


Ethical Concerns

• Most people agree that there are no ethical objections to using adult multipotent stem cells.

• Different people see the status of the human embryo differently

• UK Law changed on 22nd Jan 2001


UK Law: Before Jan ‘01

• Human Embryos only used in following cases:– To promote advances in the treatment of infertility– To increase knowledge about causes of

congenital disease– To increase knowledge about the causes of

miscarriage– To develop more effective methods of

contraception– To develop methods for detecting gene or

chromosome abnormalities in embryos before implantation


UK Law: Current

• ‘spare embryos’ from in vitro fertilisation treatment can now be used as a source of embryonic stem cells for the purpose of research into serious disease

• On 27 Feb 02 extended to include fundamental research necessary to understand differentiation and dedifferentiation of cells


United States of America

• There is no U.S. Law against human embryonic stem cell research

• Bush’s 2001 policy limited federal funding of stem cell research only to what existed at the time

• Some scientists say that many of the cell lines are deteriorating, contaminated or were developed through obsolete methods, making them inadequate to determine the potential therapeutic value of embryonic stem cells

• Different states can have their own laws, e.g.– California & New Jersey allow state funds to be used on

embryonic stem cells– South Dakota bans research on any embryo


SNAB Ethical Framework

Making decisions for yourself

I’m ill, I want the treatment

It’s my embryo

Maximising the amount of good in the world

More treatments = Healthier People

Rights & DutiesHuman rights

Right to life

Religious teaching

Leading a virtuous lifeJustice: If it’s legal then its OK

Wisdom: Scientific advances are important

Moderation: multipotent cells OK, pluripotent cells not OK


Religious Concerns

• Religious concerns are rooted in views about ‘life’. What is life…?– the accidental result of the interaction of

chemical substances?– the gift of a Creator God?

Your personal answer to this question may affect how you feel about stem-cell research. But try to put yourself in other people’s shoes…


Life…an accident?

• Some secular philosophers would argue that human life is precious because it is rare (in galactic terms). Therefore to destroy life is morally wrong.

• Others would argue that there is no difficulty in using the cells of a zygote or blastocyst – as many die naturally in any case.

• Difficult choices: is it morally defensible to use one (potential) life to help another?


If Life is an accident, you tell me…

• If life is an accident, does it matter what happens to a few cells?

• Is there any difference between destroying a potential human or, say, eating meat?

• Is there a reason for considering human life to be more precious than any other life?

• Is it morally right to use one life to save another?

• Is a potential human less valuable than a developed human?


Life…a gift? Consider the Bible…

• “You (God) created my inmost being; you knit me together in my mother’s womb” (Psalm 139)

• “The Lord God formed the man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being” (Genesis 2:7)


Life…a gift? Consider the Qur’an… (Surah 23:12-14)• Verily, We created man from a product of wet earth;

(raw materials of life)• then placed him as a drop of seed (sperm/egg?) in a

safe lodging (womb?)• then We fashioned the drop into a ‘clinging thing’

(zygote?)• then We fashioned the ‘clinging thing’ into a ‘little

lump’ (blastocyst?)• then we fashioned bones for the little lump (foetus?)• then we clothed the bones with flesh (developed

foetus?)• and then produced it as another creation. (baby)


Life…a gift?

• Some religious philosophers (theologians) argue that a gift from God comes with certain ‘conditions’ – like a manufacturers instructions. (e.g. “Warranty is void if cover is removed”)

• Those conditions may include:

- “The Lord gives and the Lord takes away”

- “Love your neighbour as you love yourself”

- “You shall not murder”


Life…a gift?

Some theologians draw a distinction between human and animal life.

So…for them…it may be acceptable to use animal stem cells, but not human ones.

Such theologians would also draw the line at combining human and animal cells for medical treatment.


Life…a gift?

Other theologians argue that we must balance scripture with reason…

e.g. God has given us the ability to reason out the mechanics of life (biology). Knowing that many eggs, zygotes and blastocysts do not survive naturally, may be an indication that God is unconcerned about stem cell research.

e.g. God brings healing through the skills of scientists and doctors (to whom he has given the gifts of reason).


Let there be life!

65% Oxygen18% Carbon10% Hydrogen3% Nitrogen1.5% Calcium1% Phosphorous0.2% Potassium0.3% Sodium Chloride1% Trace Elements

Trace elements:

Magnesium, Iron, Fluorine, Zinc, Silicon, Zirconium, Rubidium, Strontium, Bromine, Lead, Niobium, Copper, Aluminium, Cadmium, Boron, Barium, Arsenic, Vanadium, Tin, Mercury, Selenium, Manganese, Iodine, Gold, Nickel, Molybdenum, Titanium, Tellurium, Antimony, Lithium, Chromium, Cesium, Cobalt, Silver, Uranium, Beryllium, Radium.

We know that the human body is made up of:


65% Oxygen18% Carbon10% Hydrogen3% Nitrogen1.5% Calcium1% Phosphorous0.2% Potassium0.3% Sodium Chloride1% Trace Elements

Trace elements:

Magnesium, Iron, Fluorine, Zinc, Silicon, Zirconium, Rubidium, Strontium, Bromine, Lead, Niobium, Copper, Aluminium, Cadmium, Boron, Barium, Arsenic, Vanadium, Tin, Mercury, Selenium, Manganese, Iodine, Gold, Nickel, Molybdenum, Titanium, Tellurium, Antimony, Lithium, Chromium, Cesium, Cobalt, Silver, Uranium, Beryllium, Radium.

Challenge…from Religion…

GO on…MAKE A HUMAN BEING!


Discuss this proposition…

“At our current level of technology, we are unable to create life…in ANY form. This is an ability that God reserves for

himself.

THEREFORE we have no right to destroy potential life, whatever the possible benefits for human kind”


AS Biology Task

• Using Activity Sheet 3.10 and your own research.

• Produce 3 A4 Posters on:– What are Stem Cells– Arguments FOR Stem Cell Use– Arguments AGAINST Stem Cell Use

joe wright portsmouth college stem cells portsmouth college science department

Documents

ebners gland cell

different types of cell

vagina urinary epithelium

secreting melanocyte

respiratory tract cells

tongue washes

urinary bladder

distal urethra