1. Chief Science Officer, SENS Foundation
Regenerative medicine for aging: are we reaching the knee of the exponential curve?
Aubrey D.N.J. de Grey, Ph.D.
Chief Science Officer, SENS Foundation

2. SENS Foundation
SENS Foundation is a US-registered charity that works to develop, promote and enable widespread access to regenerative medicine solutions to the disabilities and diseases of…
AGING

3. But surely <insert favourite knee-jerk reaction>?
Treating aging is just preventative geriatrics
Old people are people too, deserve health
Is medicine good only so long as it doesn’t work very well?
Was the Industrial Revolution a bad thing?
How much did Jenner/Pasteur understand?

4. What is…
Regenerative medicine?
Aging?

5. What is regen med?
Any intervention that seeks to restore the structure of a tissue/organ to its state before it suffered damage

6. What is aging? Metabolism ongoingly causes “damage”. Damage
eventually causes pathology.

7. Options for intervention
Gerontology
Geriatrics
Metabolism
Damage
Pathology

8. Problem: this is metabolism

9. Options for intervention
Gerontology
Maintenance
Geriatrics
Metabolism
Damage
Pathology
Claim: unlike the others, the maintenance approach may achieve a big extension of human healthy lifespan quite soon.

10. No new type of damage confirmed since 1982!
This is the damage
Cell loss, cell atrophy
Division-obsessed cells (cancer)
Death-resistant cells
Mitochondrial mutations
Intracellular junk
Extracellular junk
Extracellular crosslinks
Seven Deadly Things
No new type of damage confirmed since 1982!

11. Robust Human Rejuvenation
Giving the middle-aged 30 years of extra healthy life:
Robust Human Rejuvenation
Damage rising with age
It or its effects reversible by
Cell loss, cell atrophy
Cell therapy, mainly
Division-obsessed cells (i.e. cancer)
Telomerase/ALT gene deletion plus periodic stem cell reseeding
Death-resistant cells
Suicide genes, immune stimulation
Mitochondrial mutations
Allotopic expression of 13 proteins
Intracellular junk
Transgenic microbial hydrolases
Extracellular junk
Phagocytosis by immune stimulation
Extracellular crosslinks
AGE-breaking molecules/enzymes

12. Robust Human Rejuvenation Some parts are in clinical trials
Giving the middle-aged 30 years of extra healthy life:
Robust Human Rejuvenation
Some parts are in clinical trials
Damage rising with age
It or its effects reversible by
Cell loss, cell atrophy
Cell therapy, mainly
Division-obsessed cells (i.e. cancer)
Telomerase/ALT gene deletion plus periodic stem cell reseeding
Death-resistant cells
Suicide genes, immune stimulation
Mitochondrial mutations
Allotopic expression of 13 proteins
Intracellular junk
Transgenic microbial hydrolases
Extracellular junk
Phagocytosis by immune stimulation
Extracellular crosslinks
AGE-breaking molecules/enzymes

13. About those amyloid trials…
Clinical endpoints not achieved
Amyloid is removed
Tau is not
No one knows what causes what in AD
Combination therapies = wings + engine

14. Robust Human Rejuvenation Other parts are making headlines
Giving the middle-aged 30 years of extra healthy life:
Robust Human Rejuvenation
Other parts are making headlines
Damage rising with age
It or its effects reversible by
Cell loss, cell atrophy
Cell therapy, mainly
Division-obsessed cells (i.e. cancer)
Telomerase/ALT gene deletion plus periodic stem cell reseeding
Death-resistant cells
Suicide genes, immune stimulation
Mitochondrial mutations
Allotopic expression of 13 proteins
Intracellular junk
Transgenic microbial hydrolases
Extracellular junk
Phagocytosis by immune stimulation
Extracellular crosslinks
AGE-breaking molecules/enzymes

16. Robust Human Rejuvenation Others are early but exciting
Giving the middle-aged 30 years of extra healthy life:
Robust Human Rejuvenation
Others are early but exciting
Damage rising with age
It or its effects reversible by
Cell loss, cell atrophy
Cell therapy, mainly
Division-obsessed cells (i.e. cancer)
Telomerase/ALT gene deletion plus periodic stem cell reseeding
Death-resistant cells
Suicide genes, immune stimulation
Mitochondrial mutations
Allotopic expression of 13 proteins
Intracellular junk
Transgenic microbial hydrolases
Extracellular junk
Phagocytosis by immune stimulation
Extracellular crosslinks
AGE-breaking molecules/enzymes

17. Intracellular junk in the artery
Endothelial Cells
Lipid-engorged Lysosome
Foam Cell

18. Bioremediation: the concept
Microbes, like all life, need an ecological niche.
Some get it by brawn (growing very fast)…
…some by brain (living off material that others can't).
Any abundant, energy-rich organic material that is hard to degrade thus provides selective pressure to evolve the machinery to degrade it.
That selective pressure works. Even TNT, PCBs…

19. Xenocatabolism: the concept
Graveyards
are abundant in human remains,
accumulate bones (which are not energy-rich),
do not accumulate oxysterols, tau etc.,
so, should harbour microbes that degrade them…
…whose catabolic enzymes could be therapeutic

20. Environmental decontamination
in vivo

21. 7-ketocholesterol degradation
a promising start
7KC over time in enrichment cultures
days
Biodegradation 2008; 19(6):

22. Stable isotope labelling and LC/MS reveal 7-ketocholesterol
metabolites in the culture supernatant
7-ketocholesterol
M = 400, M13C = 401
Dione metabolite ?
M = 398, M13C = 399
Hydroxylated dione ?
M = 414, M13C = 415
Culture growing on
7-ketocholesterol
Culture growing on
13C-labeled
7-ketocholesterol

23. COX/LAMP1 co-localizes with AO
Acridine Orange
EGFP
Merge

24. pEGFP-COXL1 transfected cells are protected from 7KC-induced toxicity
Mathieu et al., Biotechnol. Bioeng. 2012; 109(9):

25. Age-related accumulation of fluorescent compounds in retinal pigment epithelium
neural retina
RPE
As you can see here in this histological section through the retina and in human RPE cels that have been removed from the eye, this lipofuscin that accumulates in RPE has a golden yellow fluorescence and occupies a considerable volume of the eye.
When a section through the retina is examined under the fluorescence microscope so that it is magnified many fold - this is a photograph of retina viewed under the microscope - this aging material can be seen as this golden yellow fluorescence
And as you can see some of these retinal pigment epiuthelial cells that have been removed from the eye…the accumulation of this material is considerabble - it is estimated that by age 80, 20% of the cytoplasmic volume of the cell occupied
. This granular material is the fluorescent pigment that accumulates with age

26. Fundus autofluorescence (= RPE lipofuscin) increases with age
Exc.: 550 nm
For instance, just as age is a risk factor for AMD, so lipofuscin increases with age
These spectrophotometric measurements of fundus autofluorescence, and thus of RPE lipofuscin demonstrate that there is a linear increase in fluorescence with age - consistent with a linear increase in lipofuscin accumulation with age
Fluorescence intensity at age 65 is 2-fold greater than at age 25
Positive correlation with age
Fluorescence intensity declines after age 70
Have shown that there is a linear increase in fluorescence intensity with age
This .. Is indicative of an increase in RPE lipofuscin with age and confirms what had already been known from histological studies
Individually corrected for lens absorption
Delori et al., IOVS 42:
MOD FA

27. A major constitutent of RPE lipofuscin is the fluorescent pigment A2E
The best known, the best characterized of the lipofuscin fluorophores is a compound we call A2E
It obtained its name from the fact that it can be synthesized in the laboratory from 2 vitamin A aldehyde molecules and 1 ethanolamine.
Eldred and Lasky, 1993
Sakai et al., 1996
Parish et al., 1998

28. A2E pyridinium bisretinoid Sakai, Decatur, Nakanishi and Eldred, 1996
A2E was originally thought to have this structure - this structure would be N retinyulidene N retinyl-ethanolamine
But this does not have the pyridinium ring - the pyrididinum ring is a signature feature of A2E
The structure of A2E was determined by Nakanishi working with Eldred to be that of a pyridinium bisretinoid - a positively charged pyridine ring with two side arms each derived from a molecule of all-trans-retinal. Based on this structure and its precursors, Nakanishi coined the name A2E - 2 vitamin A aldehydes and 1 ethanolamine.
A2E is often stated in the literature to be N-retinylidene-N-retinylethanolamine but the compound so named would be thus, a structure wihtout this unusual pyridinium ring - the pyridinium ring is a unique feature of A2E - a signature
Sakai, Decatur, Nakanishi and Eldred, 1996

29. iso-A2E A2E Amphiphilic compound 2 hydrophobic side-arms cationic
Cl -
2 hydrophobic
side-arms
cationic
polar head
Cl -
From the outset we were interested in the tendency of A2E to perturb cell membranes because it has an amphiphilic structure - with a polar head and two hydrophobic side-arms. A2E is a cationic amphiphile but it exists as a salt. Its counterion, at least under physiological conditions, is probably chloride. The fact that it is an amphiphile, its bulky wedge-shape and the behaviour of its counterion are all factors that are important in terms of its interactions with membranes. Actually we would expect the photoisomer iso-A2E to penetrate the membrane more easily because it is more streamlined.
so when introduced to the cells at moderate extracellular concentrations, A2E accumulates in the cells in a benign manner
however, at high concentrations, a2E is damaging
A1E(mw 352.7) is a nonphysiological single side armed pyridinium molecule that retains both hydrophobic and hydrophilic elements (ends) .
A1E and A2E have the same hydrophilic head group (pyridinium ring) yet the structure of A1E is more typical of a detergent. Our finding that A1E penetrates and disrupts the cell membrane (as indicated by loss of viability) faster than A2E could well be an effect of shape rather than just size.
That A2E enters more sluggishly is cnsistent with the view that A2E may traverse the plasmam membrane by endovesiculation. Since A2E becomes sequestered within the lysosomal compartment of the clel, these findings are important to our understanding of whether and how A2E may interact with lysosomal membranes.
iso-A2E
A2E

32. Steps to biomedical application
Isolate competent strains; select by starvation.
Identify the enzymes (mutagenesis, chemistry, genomics).
Make lysosome-targeted transgenes; assay cell toxicity.
Assay competence in vitro (more mutagenesis/selection).
Construct transgenic mice; assay toxicity in vivo.
Assay competence in disease mouse models.
Test in humans as for lysosomal storage diseases.

33. A word about “MetaSENS”
SENSF does research to implement SENS
But is that enough? Three reasons why not:
Is SENS complete? (Vijg lab): “prot pleio”
Is SENS needed? (Reis lab): “weather”
<cue interminable digression re primate CR>
What will SENS cause? (Hughes group)

34. Learn more Read the (semi-technical) book. Visit us on the web at
Available at Amazon and all good book stores.
Paperback is cheaper, and has an extra chapter!
Visit us on the web at
Drop us a line at

35. www.sens.org SENS Foundation aubrey@sens.org
SENS Foundation works to develop, promote and ensure widespread access to regenerative medicine solutions to the disabilities and diseases of aging.