Implications of Telomere

Maintenance in Aging-Related

Disease Progression

Fundacion Fernandez-Cruz, Madrid

October 26, 2015

Elizabeth Blackburn, PhD

University of California San Francisco

Telomeres: what are they?

…and why do we care?

Impacts of unbalanced

telomere maintenance in humans

Influences on telomere maintenance in

humans

NON-GENETIC GENETICEnvironmental Life events/behavior

First, a framework……

Aging-related diseasesoften go hand-in-hand (co-morbidity):

Poor immune function Diabetes Cardiovascular disease Cancers Mental/cognitive disorders/depression

Aging-related diseasesoften go hand-in-hand (co-morbidity):

Poor immune function Diabetes Cardiovascular disease Cancers Mental/cognitive disorders/depression

“The World Health Organization (WHO) projects that both

cardiovascular disease (CVD) and major depressive

disorder (MDD) generate the greatest loss of ‘disability-

adjusted life years’ in 2030.”

van Marwijk BMC Cardiovascular Disorders 2015, 15:40

Telomeres: what are they?

…and why do we care?

Impacts of unbalanced telomere maintenance

in humans

Influences on telomere maintenance in

humans

Telomeres

cap ends of

chromosomes

3’

Telomeric DNA Structure

5’3’ 5’

Telomere

Chromosome

Simple repeated DNA

sequence

Blackburn and Gall, 1978

… and in yeast too

Blackburn and Szostak, 1982;

Shampay, Szostak and Blackburn 1984

Tetrahymena thermophila

- “Pond scum”

The Telomere

– the protective cap at every chromosome end

TTAGGGTTAGGGTTAGGGTTAGGGTTAGG

GAATCCCAATCCC

Protective proteins

ce

ll d

ivis

ion

s

Eventual senescence

Predicted, if DNA replication alone acts on DNA:

Loss of DNA from the chromosome end

Watson, 1972, Olovnikov, 1971

T TG T GTGG G GG GT GTGG G

DISCOVERY OF TELOMERASE

Tetrahymena cell extract

Mg++

dGTP + TTP

5’ 3’ OH

SYNTHETIC TELOMERE IN TEST TUBE

T TG T GTGG G GG GT GTGG G G T GTGG G G G

Greider and Blackburn, 1985

Carol Greider,

UC Berkeley

ca.1985

GGGGTTGGGGTTGGGGTTGGGGTTGCCCCAACCC AACCCCAAC

5'

3'

The solution to telomere attrition

Telomerase: a

telomere-synthesizing reverse transcriptase

ChromosomeTerminus

GGGTTG

protein RNA

Greider and Blackburn, 1985, 1987, 1989

5'3'

cell d

ivis

ion

s

Cells keep dividing

Most human cancers

With sufficient

telomerase:

Addition and shortening

stay balanced

ce

ll d

ivis

ion

s

After a delaySTOP

Human cells: insufficient telomerase

ce

ll d

ivis

ion

s

Human cells: insufficient telomerase

Senescence

Cell malfunctions- Mitochondrial malfunction

- pro-inflammatory, tumorigenic factors

Genomic instability

STOP

mitochondria

TelomereUncapped Telomere!

Telomere damage:

A Vicious Cycle

http://omx.hms.harvard.edu/ Cell Image:

Harvard Medical School OMX SIM microscope

Secreted

Inflammatory

factors

DNA

http://omx.hms.harvard.edu/

Telomeric

repeat

tracts

gradually

shorten

over human

lifetimes

Many normal human cells have limiting or no

telomerase and their telomeres shorten with age

Senescence Death ?

WHAT CAN SAVE THE CELLS? Telomerase action:

- Active: stem cells, germ cell lineages

- Low/none: many normal adult cell types

Genetic

anticipationChange in

disease type

Pulm. Fibrosis

Aplastic anemia/Dyskeratosis

congenita

Unique genetics of autosomal dominant

(haploinsufficiency) telomere syndromesRepeated

Telomeric DNA

Sequence Mutant hTR or

hTERT gene

Unique genetics of autosomal dominant

(haploinsufficiency) telomere syndromesRepeated

Telomeric DNA

Sequence Mutant hTR or

hTERT gene

WT*

WT*: Telomere length is NOT

reset/restored in the next

generation, despite restoring

WT genotype

WT * Inherited telomere shortness ALONE causes disease

…and why do we care?

Impacts of unbalanced telomere maintenance

in humans

NON-GENETIC GENETICEnvironmental Life events/behavior

Telomere

Attrition

Risks for aging-related diseases- and mortality

Poor immune function Cancers Cardiovascular disease Diabetes Mental/cognitive disorders/depression

From much research we now know:

Telomeric DNA Structure

Telomere

Chromosome

Simple repeated DNA

sequence

Measure telomere length- e.g., in 100,000 people

The Kaiser Permanente Research Program

on Genes, Environment, and Health (RPGEH)

GERA cohort– Biospecimens:Genetic (GWAS) and biomarker - TELOMERE LENGTH data - saliva and DNA collected 2008 – 9 N=100,000

– Comprehensive clinical data from KPNC Electronic Medical Records (outpatient, inpatient, laboratory, pharmacy, imaging, pathology)

• Complete since 1995 -- Continuously updated

– Participant survey and interview data

• Sociodemographic factors -- Family history

• Behavior

– Environmental exposure data geographic etc

Environmental exposures

Cathy Schaefer, PhD, Director. Neil Risch Elizabeth Blackburn

Kaiser-Permanente University of California, San Francisco

Age

Re

lati

ve T

elo

me

re L

en

gth

20 30 40 50 60 70 80 90

Cross sectional relationship of mean telomere length

with age: Nicoya Exceptional Longevity Blue Zone vs.

Costa Rica population

Rehkopf et al 2013

Nicoya Blue Zone

Costa Rica

Age

males

females

Re

lati

ve T

elo

me

re L

en

gth

20 30 40 50 60 70 80 90

GERA Cohort

Cross sectional relationship of mean human telomere length

with age: males and females.

Mean saliva Telomere Length (cells in saliva). Error bars are 1 s.e. of mean

Lapham, Kvale et al, 2015.

Schaefer et, Unpublished

GERA cohort: Odds of all-causes mortality

within 3 yrs of telomere measure

(N=100,000; ages 20 - 95)

Telomere length at this time

was measured

(N= 100,000)

Who had died

within the 3 years

since telomere length

measure

(N= ~ 2,500)

2009 2012

Compare to

Mean Baseline Telomere Length

Year

time

Copenhagen study: Odds of all-causes mortality

Mean follow-up time after

leukocyte telomere measure = 7 yrs.

Telomere length at this time

was measured

(N= 64,637)

Who had died

~ 7 years (mean time)

after telomere length

measure

(N= ~ 7,604)Compare to

Mean Baseline Telomere Length

Year 0 = baseline

time

Rode et al, 2015

Copenhagen study

0

200

400

600

800

1000

1200

1400

0 1 2 3 4 5 6 7 8 9 10

Any cancer

Cardiovascular

Death Othercauses

All-causemortality

Raw

Number of

Deaths

(unadjusted)

Numbers of Deaths by Telomere Length Decile (unadjusted)

Rode et al,

2015

Copenhagen

study

Telomere Length decile:

1 = longest 10 = shortest

Leukocyte Telomere Length Independently Predicts All-cause MortalityN = 64,637 (7,604 deaths) (Mean Follow-Up time = 7 years)

Mortality

Hazard

Ratio

Multivariate

Adjusted

Decile 10 = Shortest

telomeres

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1 2 3 4 5 6 7 8 9 10

Multivariate-Adjusted All-cause Mortality Hazard Ratios vs. Baseline Leukocyte Telomere Length

HR…

Rode et al, 2015

Copenhagen

study

1 = Reference

Telomere Length

decile;

1 = longest 10 = shortest

Telomerase: Dr. Jekyll AND Mr. Hyde

unlimitedreplicativecapacity

finitereplicativecapacity

telomeraseRb-/ p16-

telomerase /ALTp53-

other changes

Less

Telomerase;

Telomere Shortness

(genetic and observed)

WORSE

CANCER

RISKS

Over-active

telomere

maintenance

(genetic)

eg, Hematological,

squamous cell,

gastrointestinal

eg, brain, melanoma, lung

Supplementary Figure 3. Plot showing effect of telomere score on melanoma risk.

Here the telomere score is divided into quartiles and melanoma case-control status

regressed on the resulting categorical variable with the lowest quartile (by telomere

length) as the baseline.

Effect on melanoma risk of telomere length score

(= Alleles predicting longer telomeres)

Q1 = Shortest

telomeres

Q4 = Longest

telomeres

Mark M. Iles et al. JNCI J Natl Cancer Inst 2014;106:dju267

Forest plot of estimated effect size (with a 95% confidence interval indicated by horizontal

bars) for telomere score (= Alleles predicting longer telomeres) on melanoma risk in nine

geographic regions (and combined result).

Mark M. Iles et al. JNCI J Natl Cancer Inst 2014;106:dju267

Genetic variants associated with longer telomere length

are associated with increased lung cancer risk among

never-smoking women in Asia

Telo. score predicting longer telomere length - higher*lung cancer risk

*Cohort =

Asian women

non-smokers

Less

Telomerase;

Telomere Shortness

(genetic and non-genetic)

WORSE

CANCER

RISKS

Over-active

telomere

maintenance

(genetic)

eg, Hematological,

squamous cell,

gastrointestinal

eg, Melanoma,

brain, lung

Hazard Ratios (with a 95% confidence interval indicated

by horizontal bars): telomere allele scores for all-cancers

mortality risk.

AND - genes that predict longer telomeres

predict higher combined all-cancers mortality risk

Rode et al,

2015

Copenhagen

study

But recall, for cancers, observed longer telomeres

predict less all-cancers mortality

Observed

Longer

telomeres

Lower risk of incident

diseases & MORTALITY

- all-causes & CVD

- combined cancers

Rode et al,

2015

Copenhagen

study

Telomere-

lengthening

common gene

variants

Lower risk of

CAD, CHD,AD

Observed

longer

telomeres

Lower risk of incident

diseases & MORTALITY

- all-causes & CVD

- combined cancers

Codd et al 2013

Zhan et al 2015

JAMA

Neurol.72:1202-

1203

ALZHEIMERS: “shorter TL was causally associated with a higher risk for AD

(odds ratio, 1.36 per SD decrease of TL; 95%CI, 1.12 to 1.67; P = .002).”

Zhan et al 2015

Non-genetic

telomere-

lengthening

influences

Telomere-

lengthening

common gene

variants

Lower risk of

CAD, CHD, AD

GREATER

RISKS

(specific

cancers and

all-cancers

mortality)

Lower risk of incident

diseases & MORTALITY

- all-causes & CVD

- combined cancers

For cancers, it isn’t just longer telomeres that matter

– it’s what made them longer that matters

Observed

longer

telomeres

• For AD and CDV risks, and mortality from CVD:

longer telomeres are good

- regardless of why they are longer.

• For cancer risks and mortality from all cancers combined:

longer telomeres can be good or bad

- it is how the telomeres got longer – genes or non-genetic - that matters.

• For OVERALL TOTAL mortality risk:

longer telomeres, statistically, are good - regardless.

SUMMARY OF

HOW CHROMOSOME ENDS RELATE TO THE END

Telomeres:

why we care -

Impacts of unbalanced telomere maintenance

in humans

Influences on telomere maintenance in

humans

A story from 2500 years ago:

how stress accelerates aging

Wu Zixu: 伍子胥

A story from 2500 years ago:

how stress accelerates aging

- not a recent or new concept

Chronic stress is known to impact on diseases

CHRONIC LIFE STRESS

Disease

Impacte.g.,

cardiovascular

A new connection

CHRONIC LIFE STRESSORS

Disease

impact

STRESS signal

integration and

processing

Cynical hostility level is associated with

telomere shortness in the

UK Whitehall Civil Servants Cohort

Brydon et al, 2011

Low Medium HighCynical Hostility Tertiles

Stressors and Shortened Telomeres in Adults • Perceived stress • Caregiver stress

– mothers of ill child– dementia caregivers

• Major Depression– duration and severity

• Former Domestic Abuse – duration of abuse

• Allostatic (stress) load– Lack of psychosocial resources

• Cumulative exposure to childhood traumas:

– or + adult PTSD

• Less education

Tyrka, 2010; Kiecolt Glaser, 2011;

O’Donovan et al, 2011; Surtees, 2011

Steptoe et al, 2011; Needham et al

2013;

Lapham, Kvale, Risch, Shaefer, Blackburn, unpubl.

Epel et al, 2004;Damjanovic, 2006; O’Donovan, 2011;

Wolkowitz et al, 2011

Simon, 2006; Wolkowitz, 2011; Verhoeven et al, 2013

Humphreys et al, 2011

Epel et al, 2004; Parks et al, 2009; Puterman 2010

Zalli et al et al, 2014

Stressors Shorten Telomeres in Children

• Early severe emotional neglect

– Institutionalized in orphanages

(length of exposure)

• Exposure to violence

• Parental education/socioeconomic status of family

• Living in a high-disorder neighborhood

• Autonomic and adrenocortical reactivity Theall et al 2014

Drury et al 2012

Kroenke et al 2011

Needham et al 2012

Shalev et al 2012

Stressors Shorten Telomeres in Children

Exposures of Mothers to Adverse Conditions during

Pregnancy are Associated with

Shorter Telomeres in the Newborns

- i.e., Transgenerational Effects:

1. Intrauterine: - psychological stress exposure

of the mother

→shorter newborn telomere length

→shorter telomeres in adult offspring too

2. Intrauterine: - folate deficiency of

the motherEntringer, Wadhwa et al, 2011, 2013, 2015

Disease

Impact

Chronic psychological stress

Reduced telomere maintenance

Disease

impact

Disease

Chronic

Stress

Connecting Chronic Psychological Stress,

Telomeres and Disease Impact

?

Mechanisms?

Stress and short telomeres: Possible mechanisms

Stress hormones

Epel et al, 2006

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

Short TL

Long TL

Z s

co

res (

ad

j.)

CortisolEpinephrineNorepinephrine

Cortisol reduces telomerase

in PBMCs and CD4+ cells

O’Donovan et al, 2011

Health ABC Study

Systemic

Inflammatory

factors

Systemic

inflammatory

markers

IL-6

TNF-α

IL-6 + TNF-α

TNF-α + CRP

IL-6 + TNF-α + CRP

Short telomeres

OR (95% CI)1.3 (1.0-1.7)*

1.5 (1.2-1.9)**

1.8 (1.3-2.4)**

1.7 (1.2-2.4)**

1.7 (1.1-2.6)**

Adjusted

for all

covariates

Systemic

Oxidative

Stress

Gazzaniga, unpubl; Effros 2008

Oxidative Stress

Ratio = serum F2-

isoprostanes/

Vitamin C

PB

MC

telo

mere

len

gth

(bp

)

Wolkowitz et al., 2011

WHICH STEPS ARE RATE-LIMITING?

BRAIN

Shorter telomeres

Reduced natural killer cell activity

Lower telomerase activity Glucocorticoid-mediated suppression

of p53 and BRCA1 gene expression

Increased pro-inflammatory cytokines

and oxidative stress

Adapted from: Spiegel, D Br J Health Psychol. 2013

Immunosenescence

Stress and short telomeres: Possible pathways

Dysregulation of diurnal cortisol

Mitochondrial

dysfunction

Shorter leukocyte telomeres = an independent risk factor for cardiovascular disease.

Cumulative

hazard

curves

Willeit P et al. Arterioscler Thromb Vasc Biol 2010;30:1649-1656

Short Telomere Length Predicted CVD

CVD

Vascular

Death

Myocardial

infarction

Stroke

Longest

Mid

Shortest

Baseline Telomere Length by Tertiles

Shorter leukocyte telomeres = an independent risk factor for cardiovascular disease.

Prediction from combination of factors?

An example from cancer patients……

Bladder cancer survival:

Interaction of leukocyte short telomeres

with depression

Depression (long telomeres)

or

Short telomeres (not depression)

or

Neither

or

BOTH

At bladder cancer diagnosis:

Lin J et al CEBP, 2014

Lin J et al CEBP, 2014

Kaplan–Meier survival curves by cross-classification of

depression score CES-D (>16 vs.

At bladder cancer diagnosis

Depression (long telomeres)

OR

Short telomeres (not depression)

OR

Neither

OR

BOTH

ONLY depression OR ONLY short telomeres OR neitherAfter 2 ½ years – Who had died

BOTH depression PLUS short telomeres

After 2 ½ years – Who had died

After 5 years – Who had diedONLY depression OR ONLY short telomeres OR neither

BOTH depression PLUS short telomeres

After 5 years – Who had died

Increasing

telomere

shortnessDepression

Bladder cancer patient

mortality

Lin J et al CEBP, 2014

Depression is related to coronary heart disease, hypertension and stroke

Licinio et al 2002. Mol. Psychiatry 7, 1031-1032

Depression = an independent risk factor for cardiovascular disease.

– depression predicts development of coronary heart disease in otherwise healthy individuals

– increased morbidity and mortality in depressed patients with coronary artery disease

• particularly after acute myocardial infarction

• independent of previous history, thereby implicating depression as a risk factor in the progression of heart disease

Licinio et al 2002. Mol. Psychiatry 7, 1031-1032

Environmental Life events/behaviorNON-GENETIC GENETIC

Telomere

Attrition

Risks for aging-related diseases- and mortality

Poor immune function Cancers Cardiovascular disease Diabetes Mental/cognitive disorders/depression

Telomere attrition: an interacting factor underlying diseases

What influences the right balance for

telomere maintenance in humans?Education.

Resiliency

factors:- Exercise

- Sleep

- Stress-

reduction

Omega-3.

Findings from

multiple

observational

studies

CHRONIC STRESS

Low education

Prenatal stress

Childhood trauma

Smoking

Abuse

Neighborhood disorder

Poor dietary intakes

Interactions with GENETIC FACTORS ?

Proper

telomere

maintenance?

Hu

ma

n h

ea

lth

Chronological age

Just a hope, or a practical approach?

Research Acknowledgements

Recent and current

Blackburn lab UCSF

Collaborating groups

Jue Lin

Kyle Lapham

Josh Cheon

Lynn Fang

Beth Cimini

Francesca Gazzaniga

Kyle Jay

Imke Listerman

Tetsuya Matsuguchi

Dana Smith

Jie Sun

Tanya Williams

Eva Samal

Tracy Chow

UCSF

Elissa Epel

Owen Wolkowitz

Sandy Mellon

Mary Whooley

Neil Risch

Pui Kwok

UCI

Prathik Wadhwa

Sonja Entringer

UCL

Andrew Steptoe

Kaiser Permanente

Cathy Schaefer

- and many more!

Research Acknowledgements

Recent and current

Blackburn lab UCSF

Collaborating groups

Jue Lin

Kyle Lapham

Josh Cheon

Lynn Fang

Beth Cimini

Francesca Gazzaniga

Kyle Jay

Imke Listerman

Tetsuya Matsuguchi

Dana Smith

Jie Sun

Tanya Williams

Eva Samal

Tracy Chow

UCSF

Elissa Epel

Owen Wolkowitz

Sandy Mellon

Mary Whooley

Neil Risch

Pui Kwok

UCI

Prathik Wadhwa

Sonja Entringer

UCL

Andrew Steptoe

Kaiser Permanente

Cathy Schaefer

- and many more!

Jue Lin

The end(s)