>>WELCOME TO THE
WEDNESDAY AFTERNOON LECTURE
SERIES. I'M AMANDA B. I AM
THRILLED TO INTRODUCE TODAY'S
SPEAKER. HELEN BLAU. I'D LIKE
TO ACKNOWLEDGE MY COHOSTS
DR. JOHN WILLIAMS FROM NIA AND
DOCTORS KAITLYN. THIS GROUP
SPONSORS MANY N ISNIH LECTURES
I THINK MANY FOLKS WILL BE
INTERESTED IN.
DR. BLAU IS A
FOUNDATION PROFESSOR AND
DIRECTOR OF THE BAXTER
LABORATORY FOR BIOLOGY. SHE IS
WORLD RENOWNED FOR HER WORK ON
NUCLEAR REPROGRAMMING. HER BODY
OF RESEARCH HAS PROVIDED THE
UNDERPINNINGS FROM CLONING AND
POTENT STEM CELLS. AMONG HER
MANY LANDMARK DISCOVERIES HAS
BEEN THE NICHE PROTEINS THAT
REGENERATE, EXPAND AND ENHANCE
THE FUNCTION OF MUSCLE STEM
CELLS. HER LAB RECENTLY
IDENTIFIED A HALLMARK NOVEL
AGING 15 PGDH AND SHOWED ITS
INHIBITION AUGMENTS MUSCLE MASS
AND STRENGTH. HER LAB WAS THE
FIRST TO DIRECT STEM CELL. MORE
RECENTLY THEY DETERMINED
MUSCULAR DYSTROPHY INTO THE
DEVELOPMENT OF THE DISEASE AND
POTENTIAL TREATMENTS.
DR. BLAU'S WORK HAS LED TO THE
DEVELOPMENT OF NOVEL
TECHNOLOGIES INCLUDING THE
DISCOVERY OF THE COMPLEMENTATION
WHICH IS NOW WIDELY USED IN DRUG
DISCOVERY. NOT SURPRISINGLY SHE
HAS AT LAST COUNT ELEVEN PATENTS
WITH AT LEAST TWO OTHERS FILED.
THIS IS JUST A SNAPSHOT OF HER
REMARKABLE CAREER, HER HONORS
FITTINGLY HAVE BEEN AS NUMEROUS
AS HER ACCOMPLISHMENTS. WITH
THE NATIONAL ACADEMY OF INSULIN
TORS A NATIVE OF THE UK EARNED
HER BA AT THE UNIVERSITY OF YORK
IN ENGLAND AND KEPT MOVING WEST
AFTER THAT RECEIVING
POST-DOCTORAL TRAINING BEFORE
JOINING STANFORD UNIVERSITY.
LASTLY I'M PROUD TO NOTE THAT
DR. BLAU IS A GRANT RECIPIENT ON
THE NATIONAL INSTITUTE ON AGING.
THANK YOU SO MUCH FOR BEING WITH
US TODAY ON BEHALF OF THE STAFF
I WELCOME YOU TO THE NIH.
>>THANK YOU SO MUCH AMMANDA.
IT'S REALLY AN HONOR TO GIVE
THIS LECTURE AND I THANK YOU FOR
THIS INVITATION. SO WHAT I WANT
TO TELL YOU ABOUT TODAY IS OUR
DISCOVERY OF A JER ROW SOMETIMES
AND IT'S ROLE IN REJUVENATING
MUSCLES AND HOW WE CAN TARGET IT
TO REJUVENATE AGING. IT'S AN
ENZYME THAT APPEAR TO HAVE A
PIVOTAL ROLE IN AGING AND
REJUVENATION. AS YOU WILL SEE.
FIRST A DISCLOSURE. I'M A
COFOUNDER OF TWO COMPANIES.
AGEING IS DEPICTED HERE BY ONE
OF MY FAVORITE ARTISTS. YOU SEE
THE YOUNG BABE AND THEN GLOWING
MOTHERHOOD AND THEN DECREPED
AGING AND THE QUESTION IS, DOES
IT REALLY HAVE TO BE THAT WAY?
AND AS SHOWN HERE, IN NATURE,
JUST A FEW YEARS AGO, WE ARE
LIVING LONGER, BOTH THE LIFE
EXPECTANCY OF MEN AND OF WOMEN
IS LONGER. BUT THESE ARE NOT
YEARS THAT ARE QUALITY YEARS
THEY'RE YEARS SPENT WITH CHRONIC
DISEASE. THE YEARS OF HEALTHY
LIVING ARE STAYING STABLE. SO
THE GOAL OF REGENERATIVE
MEDICINE OR STEM CELL BIOLOGY IS
TO INCREASE HEALTH SPAN OR
QUALITY OF LIFE SO THAT THE
PROPORTION OF YOUR LIFE SPAN
THAT IS SPENT DOING THE THINGS
YOU LOVE TO DO LIKE RUNNING A
MARATHON OR SKIING OR HIKING ARE
PROLONGED. LESS TIME WITH
CHRONIC DISEASE. AND I THINK
THIS IS HIGHLIGHTED, THIS NOTION
OF HEALTH SPAN IN THE MYTH, THE
ROMAN MYTHOLOGY OF AURORA AND
TIE THON NEWS. AURORA WAS THE
GODDESS OF DAWN AND FELL IN LOVE
WITH TIE THON US. DEPICTED HERE
AT THE VATICAN WHERE THE ACADEMY
MEETS AND FELL IN LOVE WITH THIS
MORTAL AND WENT TO JUPITER, THE
KING OF THE GODS AND SAID PLEASE
GRANT ME JUST ONE WISH. I WANT
TIE THON US TO LIVE FOREVER, TO
HAVE ETERNAL LIFE AND SO JUPITER
GRANTED HER WISH. GAVE HIM
ETERNAL LIFE AND DID NOT ASK FOR
ETERNAL YOUTH AND WHAT HAPPENED
WAS TIE THON US AGED AND BECAME
DECREPED AND LIVID FOREVER AS A
DECREPIT OLD MAN. NOT ONLY DO
WE WANT AN INCREASE IN LIFE SPAN
BUT ALSO HEALTH SPAN AND WHAT IS
CRUCIAL TO YOUR HEALTH SPAN?
MUSCLE IS ONE OF THE THINGS THAT
IS ABSOLUTELY CENTRAL TO
EVERYTHING YOU DO IN LIFE
WHETHER YOU'RE A DANCER IN A
BALLET, OR YOU ARE ROW DAN'S
THINKER AND USING YOUR MUSCLES
TO THINK AND FOR POSTURE AND IF
YOU'RE STEF CURRY OF THE GOLDEN
STATE WARRIORS YOU'RE USE L
EVERY MUSCLE IN YOUR BODY TO
SHOOT THOSE THREE POINTERS.
MUSCLE IS VERY IMPORTANT. AND
WITH AGING WE LOSE MUSCLE MASS
AND STRENGTH. HUMANS LOSE 10%
OF MUSCLE MASS PER DECADE AFTER
THE AGE OF 50. AND 5% OF PEOPLE
OVER THE AGE OF 60 ARE AFFECTED
BY SAR KOE PEÑA WHICH IS THE
DEBILITATING LOSS OF MUSCLE MASS
AND STRENGTH. BY THE AGE OF 80,
ONE-THIRD OF PEOPLE ARE AFFECTED
BY SARCOPENIA. SO WHAT IS
SARCOPENIA. AN INCREASE IN
FRAILTY, LOSS OF MUSCLE MASS,
REDUCES THE ABILITY TO PERFORM
ROUTINE TASKS LIKE GETTING UP
OUT OF A CHAIR. THERE'S AN
INCREASED INCIDENCE IN FALLS,
AND THIS COSTS BILLIONS OF
DOLLARS BECAUSE PEOPLE BECOME
DEPENDENT AFTER THAT. THEY
OFTEN END UP IN INSTITUTIONS,
AND ASSISTED LIVING AND THEIR
MORTALITY IS ACCELERATED. SO
WHAT I WANT TO TELL YOU ABOUT
TODAY IS OUR DISCOVERY OF A WAY
TO POTENTIALLY MEDIATE AND AVOID
THIS DOWNWARD SPIRAL AND THAT IS
THE DISCOVERY OF THIS GEROZYME
AND OUR FINDING THAT INHIBITING
THIS GEROZYME INCREASES NOT ONLY
STEM CELL FUNCTION AND
REGENERATION BUT ALSO
REJUVENATES MUSCLE TISSUE
FUNCTION AND IT ACTS BY
ENHANCING THE BODY'S OWN HEALING
MECHANISMS, THE NATURAL HEALING
MECHANISMS. SO WE'VE TAKEN TWO
APPROACHES, TO TARGET MUSCLE
STEM CELLS AND FIBERS. THE STEM
CELLS LIE ALONG THE MATURE
MUSCLE FIBERS. THEY ARE
DEDICATED STEM CELLS THAT ARE IN
A QUIESCENT STATE READY TO
REPLENISH THE MUSCLE FIBERS AND
WE'RE TARGETING BOTH THESE STEM
CELLS AND THE MUSCLE FIBERS.
THE MATURE MUSCLE FIBERS. SO
MUSCLE STEM CELLS SHOWN HERE
RESIDE IN A NICHE ALONG THE
MUSCLE FIBER AND AS SHOWN HERE
BY ALECK SANDRO MARROW HE
IDENTIFIED A MICROGRAPH THAT
THIS WAS A SATELLITE CELL. IT
WAS LYING ALONG THE MUSCLE FINER
AND HE PREDICTED IT WAS THE STEM
CELL IT WASN'T UNTIL MANY
DECADES LATER THAT THIS WAS
PROVEN TRUE AND THESE STEM CELLS
EXPRESS PAC 7 AND THAT IS
ESSENTIAL TO THEIR SELF RENEWAL
AND IF THERE'S AN INJURY THEY
SPRING INTO ACTION, BECOME
ACTIVATED.
COMMITTED PROGENITORS AND FUSE
INTO THE MYOFIBERS TO REFUEL THE
MY OWE FIBER. WELL IN ORDER TO
STUDY THE STEM CELLS AND
UNDERSTAND THEIR REGULATION, WE
HAD TO IDENTIFY WAYS TO ISOLATE
THEM AND FOR THIS PURPOSE WE
USED A POTENT TRANSGENIC MODEL
THAT EXPRESSES GFP AND LIEU
SIEVE RACE IN ALL THE CELLS OF
THE BODY AND WE ISOLATED SINGLE
CELLS AND WE DID MANY
EXPERIMENTS INJECTING SINGLE
CELLS INTO THE INJURED LIMBS OF
MICE. LOOK FOR ENGRAPHMENT AND
EXPANSION OF THE STEM CELLS BY
BIO LUMINESCENT IMAGING. AND WE
IDENTIFIED USING THIS, THESE
THREE MARKERS THAT ALLOW
ISOLATION OF THE STEM CELLS.
AND THIS SHOWS YOU THE KEY
EXPERIMENT THAT WE DID. WE
ISOLATED SINGLE CELLS, INJECTED
THEM INTO THE INJURED HIGH LIMB
OF A MUSCLE AND YOU CAN SEE
THREE OUT OF 72 TRANSPLANTS GAVE
A ROBUST IMAGING SIGNAL THAT YOU
CAN DETECT HERE IN A CCD CAMERA
AND THOSE CELLS ALSO CONTRIBUTED
TO MATURE MYOFIBERS AS YOU CAN
SEE HERE BY GFP. SO THEY MET
THE QUINTESSENTIAL DIFFERENT IN
ADDITION OF A STEM CELL OF KREFL
RENEWAL AND DIFFERENTIATION.
ONCE WE HAD THE STEM CELLS WE
THOUGHT, NOW WE CAN STUDY THE
FACTORS THAT REGULATE THEM BUT
WE ENCOUNTER YET ANOTHER
PROBLEM. ANOTHER CHALLENGE.
WHICH WAS THAT IF YOU INJECTED
FRESH STEM CELLS INTO THE
INJURED HIND LIMB OF A MUSCLE
THEY EXPAND ROBUSTLY BUT AS YOU
SEE HERE IF YOU CULTURE THEM ON
PLASTIC, THE USUAL CULTURE
DISHES YOU SEE A LOSS OF STEM
CELL FUNCTION, REDUCTION IN BLI
SIGNAL AND THAT'S HIGHLIGHTED
HERE SO THE STEM CELLS LOSE
THEIR FUNCTION IN TISSUE CULT
CULTURE. SO WE WONDERED HOW TO
OVERCOME THIS. WE DECONSTRUCTED
THE NICHE IN DIFFERENT MATERIALS
THIS WORK WAS DONE BY A
MULTIDISCIPLINARY TEAM. BY
PENNY GILBERT. WHO SPECIALIZED
IN ARTIFICIAL INTELLIGENCE WHO
HELPED US DEVELOP ALGORITHMS.
AND BEN COSGROVE A CHEMICAL
ENGINEER. AND WHAT THEY FOUND
WAS THAT MUSCLE, WHEN THEY
LOOKED AT THE RIGIDITY OF MUSCLE
THEY FOUND THAT IT HAS A
STIFFNESS OF TWELVE KILO PASCALS
WELL HOW DOES THAT COMPARE TO
PLASTIC WHEN WE DID REE I DON'T
MEAN TRY OF PLASTIC. PLASTIC IS
FIVE ORDERS OF MAGNITUDE STIFFER
THAN HEALTHY TISSUE SO IT IS A
RIGIDITY THAT MUSCLES WOULD
NEVER ENCOUNTER IN THE BODY. SO
WE ENGINEERED HYDRO JELLS AND
MADE SINGLE CELL MICRO WELLS AND
BIO LIEU METTIC NICHES BY
COMBINING TWO DIFFERENT PEG
MONOMERS IN DIFFERENT
CONCENTRATIONS SO THAT WE COULD
ACHIEVE DIFFERENT RIGIDITIES AND
THESE HYDRO JELLS HAVE MANY
DIFFERENT ADVANTAGES. NOTHING
STICKS TO THEM. THEY'RE WELL
DEFINED UNLIKE OTHER GELS AND
THEY HAVE MECHANICS. AND YOU
CAN CONTROL LIGAN PRINTING WHICH
IS IMPORTANT FOR MIMICKING
VARIOUS ECM EXTRACELLULAR MATRIX
COMPONENTS IN THE MICRO WELLS
AND THEY CAN BE USED FOR SINGLE
CELL CLDOAL ASSAYS HERE YOU CANE
THE MICRO WAYS.
SO DOES IT MATTER? PENNY
DESIGNED THE STEM CELLS USING
OUR PARAMETERS AND PLATED THEM
IN SINGLE WELL HYDRO JELLS. OF
DIFFERENT RIGIDITY. TWO IS
ABOUT THE RIGID DID I OF BRAIN,
TWELVE IS MUSCLE, 22 IS A LITTLE
STIFFER AND 10 TO THE 6TH IS THE
RIGIDITY OF PLASTIC AND AFTER
ONE WEEK SHE TRANSPLANTED THE
CELLS INTO THE INJURED HIND LIMB
MUSCLES OF A MOUSE AND LOOKED
FOR ENGRAPHMENT IN TERMS OF THE
POTENT ASSAY WE HAVE FOR STEM
CELL EXPANSION AND ENGRAPHMENT.
WHAT SHE FOUND WAS THAT IT MAKES
A HUGE DIFFERENCE. AND THAT
WHEN YOU LOOK HERE ON THE LEFT,
ARE A LARGE NUMBER OF DIFFERENT
MOUSE LIMBS BUT IN THE MIDDLE
YOU CAN SEE TYPICAL EXAMPLES AND
WHEN THE HYDROGEN WAS TOO SOFT,
AS IN TWO KILO PASCALS ARE STIFF
AS IN 42 THEY DON'T ENGRAPH AS
WELL AS IF THE CELLS ARE ON A
MODULUS OF TWELVE KILO PASCALS
WHICH IS TYPICAL OF THAT OF
HEALTHY MUSCLE TISSUE AND YOU
CAN SEE ON THE APPROPRIATE
MODULUS THAT MIMICS THE STEM
CELL NICHE OF THE HEALTHY TISSUE
50% OF THE CELLS ENGRAPHED. TO
SUMMARIZE THIS PART OF THE TALK,
ONE IS TWO SOFT, ONE IS TOO
STIFF AND ONE IS JUST RIGHT AND
THE STEM CELLS CARE JUST AS WE
DO ABOUT THE STIFFNESS OF THEIR
BEDS. AND THIS IS A PARAMETER
THAT IS KEY FOR MAINTAINING
CULTURE AND HAS BEEN USED NOW
FOR NUMEROUS DIFFERENT STEM CELL
TYPES. NOW THAT WE CAN MAINTAIN
THESE STEM CELLS WE CAN LOOK FOR
REGULATORS OF THEIR -- THAT
COULD CONTROL THEIR EXPANSION
AND MAYBE EVEN REJUVENATION SO
WE WERE INTERESTED IN WHAT
HAPPENS WITH AGING AND WE
ISOLATED STEM CELLS FROM AGED
MICE AND FOUND IF WE INJECTED
TEN CELLS AT A TIME INTO THE
INJURED HIND LIMBS WE FOUND THAT
THE FUNCTION OF THESE STEM CELLS
FALLS OFF WITH AGING. AND YOU
SEE THIS DROP FROM 56%
ENGRAPHMENT IN ONE TO 21% IN THE
AGED THAT'S EVIDENT IN THE
IMAGING AND ALSO BY CONTRIBUTION
TO THE MUSCLE FIBERS AS
EVIDENCED BY GFP. WHEN WE DID
LIMITING DILL SOLUTION ANALYSIS
WE FOUND THAT TWO-THIRDS OF THE
CELLS ARE NONFUNCTIONAL IN THE
AGED ONLY ONE-THIRD ARE
FUNCTIONAL AND WE WONDERED IF WE
COULD FIND WAY TO RESTORE THAT
FUNCTION. SO BEN COSGROVE IN
THE LAB DID THIS IN THE DRUG
SCREEN AND FOUND A SMALL
MOLECULE THAT INHIBITS P 38
KINASE AND HEAR YOU CAN SEE THAT
IN AGED STEM CELLS THERE IS AN
INCREASE IN THE TARGET PHOSPHO-P
38 SO TO TEST WHETHER THIS WOULD
HAVE AN EFFECT WHAT BEN DID WAS
ISOLATE AGED MUSCLE STEM CELLS
AND YOUNG MUSCLE STEM CELLS AND
PLATE THEM EITHER ON PLASTIC OR
ON HYDRO GEL IN THE PRESENCE OR
ABSENCE OF THE DRUG THE SB 202
INHIBITOR OF MAP KINASE AND
TRANSPLANTED THE CELLS INTO THE
INJURED HUNDREDED LIMBS OF A
MASS AND THIS WAS DONE BY SNAKE
VENOM TOXIN THAT DOES EXTENSIVE
DAMAGE TO THE FIBERS THIS IS
WHAT HE FOUND. THE YOUNG MUSCLE
STEM CELLS ARE DOING SO WELL ON
HYDRO GEL THAT THE DRUG MAKES NO
DIFFERENCE BEING GRAPHED AS YOU
CAN SEE HERE AND THE AGED ON
PLASTIC ARE DOING SO POORLY THAT
EVEN IN THE PRESENCE OF THE
DRUG, THEY'RE NOT RESTORED.
HOWEVER IF YOU PLATE THE AGED
STEM CELLS ON A HYDRO GEL THAT
MIMICS THE NICHE WITH THE MAP
KINASE INHIBITOR YOU SEE ROBUST
EXPANSION OF THE STEM CELLS.
AND THAT IS DEPICTED OVER HERE
FOR A LARGE NUMBER AND YOU CAN
SEE THAT WE'VE RESTORED THE
POTENTIAL OF THE AGED BACK TO
THAT OF YOUNG. SO THIS SHOWS
THERE'S A SYNERGY OF THE
BIOCHEMICAL AND PHYSICAL
PROPERTIES. THE HYDRO GEL RIGID
DID I -- RIGIDITY AND A
SIGNALLING PATHWAY.
WELL THAT WAS ALL GOOD AND WELL
FOR ENGRAPHMENT BUT WHAT ABOUT
FUNCTION? WE NOW SOUGHT TO FIND
OUT WHETHER THIS INCREASED
MUSCLE STRENGTH.
SO IN THIS CASE BEN ISOLATED THE
STEM CELLS FROM 24 MONTH OLD
MOUSE, CULTURED THEM ON HYDRO
GELS IN THE PRESENCE OR ABSENCE
OF THE P 38 MAP KINASE INHIBITOR
SB AND TRANSPLANTED THEM INTO
INJURED, AGED TA MUSCLES OF THE
LEG. AND WHAT YOU SEE HERE IS
THAT YOUNG -- YOUNG MICE HAVE A
HIGH TWITCH FORCE STRENGTH.
THIS IS THE MEASURE OF THEIR
STRENGTH AND WITH AGING THAT
DECREASES NEARLY 50% AND AFTER
INJURY WITH NO TECH SIN IT
INCREASES FURTHER.
IF WE INCREASE THE PROGENY THAT
WERE CULTURED ON THE HYDRO GEL
TOGETHER WITH THE P 38 MAP
KINASE INHIBITOR YOU NOW RESTORE
STRENGTH TO THAT YOUNG. THIS IS
SHOWN FOR ONE EXAMPLE HERE.
BUT WE DID A NUMBER OF DIFFERENT
MICE AND THAT'S SUMMARIZED HERE
AND YOU CAN SEE THAT WE'VE
RESTORED THE STRENGTH OF THE
AGED MUSCLES THAT OF YOUNG
MUSCLES BY THIS TREATMENT. SO
THIS STANDS AS A VERY USEFUL
CELL THERAPEUTIC APPROACH FOR
ISOLATING THE CELLS,
REJUVENATING THEM AND PUTTING
THEM BACK INTO THE MUSCLE BUT
THAT'S QUITE A LABOR-INTENSIVE
AND NOT VERY COST-EFFECTIVE
APPROACH AND SO WE SOUGHT OTHER
APPROACHES. WE ALSO MORE
RECENTLY HAD DESCRIBED ANOTHER
MARKER OF AGING STEM CELLS THAT
AND THAT IS CD 47 AND THIS WAS
DISCOVERED BY ERE MA USING A
HIGHLY DIMENSIONAL ANALYSIS.
WHERE YOU CAN STAIN STAIN CELLS
AND SUBJECT THEM TO -- YOU
NEBULIZE THEM AND DO TIME OF
FLIGHT. AND YOU CAN LOOK AT THE
CLUSTER OF MARKERS AT THE
INDIVIDUAL CELLS BY X-SHIFT
ANALYSIS. YOU CAN SEE HERE WHEN
WE LOOK AT THE AGED STEM CELLS
THEY'RE EXPRESSING THE HALLMARK
TRANSCRIPTION FACTOR OF THE STEM
CELL AND THEY HAVE ELEVATED CD
47 ON THEIR CELL SURFACE. AND
WHEN WE LOOKED AT SEPARATION YOU
CAN SEE THAT THE PROPORTION OF
CELLS EXPRESSING HIGH CD47 IS
INCREASED WITH AGING, THAT'S
SHOWN HERE DOWN BELOW.
80% OF THE AGED STEM CELLS HAVE
ELEVATED CD47 ON THEIR CELL
SURFACE AND THIS AFFECTS THEIR
ENGRAPHMENT POTENTIAL.
YOU CAN SEE NOW THAT THEIR
ENGRAPHMENT WHEN YOU LOOK AT THE
CD47 HIGH FROM YOUNG AND AGED
ENGRAPHMENT POTENTIAL DROPS
REMARKABLY AND THIS TURNS OUT TO
BE DUE TO ALTERNATIVE
POLYADENYLATION CHOICE THAT
LEADS TO MORE OF THE LOCK
ISOFORM OF CD 47 THAT IS
LOCALIZED TO THE CELL MEMBRANE.
WHEREAS THE INTRACELLULAR FORM
IS NOT THE ALTERNATE FORM IS NOT
EXPRESSED ON THE CELL SURFACE.
IT IS THE CELL SURFACE FORM THAT
HAS THIS DELL LE TIERS YOU
AFFECT AND IN FACT CD47 IS A
VERY INTERESTING MOLECULE.
YOU PROBABLY KNOW IT AS THE
DON'T EAT ME SIGNAL THAT IS
EXPRESSED ON CANCER CELLS TO
AVOID THE IMMUNE SYSTEM AND IN
FACT IT MEDIATES BY DIRECTIONAL
SIGNALLING. IT'S A LIGAND FOR
ALMA WHICH IS THE DON'T EAT ME
SIGNAL AND PROBABLY THE STEM
CELLS, IT PREVENTS THE IMMUNE
SYSTEM FROM CLEARING THE STEM
CELLS AS WELL. AND IT'S ALSO A
COMPONENT OF THIS COMPLEX AND
IMPORTANTLY FOR OUR PURPOSES,
IT'S A RECEPTOR FOR THROMBO
RESPONSE DIN ONE AND WE REASON
THAT THROMBO RESPONSE DIN MIGHT
BE PLAYING A ROLE. WE FOUND
THAT THE AGED STEM CELLS,
SUBSTANTIVE AGE STEM CELLS ARE
SECRETING THROMBO RESPONSE DIN
ONE AND THAT INHIBITS THE
PROLIFERATION OF THE AGED STEM
CELLS.
IN FACT, IF WE TREAT THE CELLS
WITH AN ANTIBODY, A BLOCKADE OF
THE THROMBO RESPONSE DIN WE CAN
OVERCOME THIS BLOCK AND ENHANCE
THE ENGRAPHMENT OF THE STEM
CELLS. SO CD IS REGULATED BY
AYDENLATION AND CAN BE OVERCOME
BY A THROMBO RESPONSE DIN
BLOCKADE. I WANT TO NOT DISCUSS
THIS FURTHER ALTHOUGH WE HAVE
VERY INTERESTING LINES OF DATA
THERE BUT I WANT TO TURN TO THIS
GEROZYME AND HOW WEALTHOUGH WE
INTERESTING LINES OF DATA THERE
BUT I WANT TO TURN TO THIS
GEROZYME AND HOW WE DISCOVERED
IT. THE GEROZYME REGULATES PD 2
LEVELS. A NATURAL INFLAMMATORY
MEDIATOR THAT STIMULATES MUSCLE
STEM CELL FUNCTION AND WE
DISCOVERED IT BECAUSE WE WERE
LOOKING FOR SOMETHING THAT MIGHT
BE IN THIS WAVE OF INFLAMMATION
IMMEDIATELY AFTER DAMAGE. WHEN
THERE'S DAMAGE TO THE MUSCLE AND
TO MANY TISSUES PGE 2 IS
ELEVATED AND THERE'S THIS WAVE
OF INFLAMMATION. AND WE REASON
THAT HAD THE STEM CELLS MIGHT BE
EXQUISITELY SENSITIVE TO
SOMETHING IN THAT INFLAMMATORY
WAVE AND THIS WORK WAS DONE BY
VERY TWO TALENTED POSTDOCS.
ANDREW HO AND ADA LAY DA PAULA.
THEY WERE LOOKING FOR REGULATORS
OF INFLAMMATION ON AC DID I
VATED STEM CELLS WE SEARCHED THE
DATABASE FROM OUR OWN LAB AND
TWO OTHERS.
LOOK FOR REGULATORS OF
INFLAMMATION. IMMEDIATELY AFTER
INJURY. IN THE STEM CELLS AND
EP 4 WAS ONE OF THE HIGHEST
HITS. A RECEPTOR FOR
PROSTAGLANDIN E 2. IT IS ON THE
CELL SURFACE.
AND WE REASONED THAT VERY LITTLE
HAS BEEN DONE TO ELUCIDATE THE
ROLE OF PGE 2 MAYBE BECAUSE IT
DOESN'T APPEAR ON A
TRANSCRIPTOME BECAUSE IT IS A
METABOLITE. IT IS DRIVE FROM
MEMBRANE PHOSPHOLIPIDS GIVING
RISE TO IRAQNY DONNIC ACID.
AND THAT CONNECT ON ANY ONE OF
FOUR RECEPTORS.
ON MUSCLE STEM CELLS AND ON
MUSCLE FIBERS EP 4 IS THE
PREDOMINANT GBCR THAT IS
EXPRESSED AND THAT IS BY EMP.
IMPORTANTLY, NSAIDS, LIKE
IBUPROFEN BLOCK THE SYNTHESIS OF
PGE 2. THEY BLOCK YOUR NATURAL
HEALING RESPONSE. TO FIND OUT
WHETHER THIS PATHWAY WAS
IMPORTANT WE CONDUCTED AN
OBLATION OF EP 4 ON STEM CELLS
BY CREATING THIS MOUSE MODEL
WHERE PAX 7 LEADS TO OBLATION OF
THE EP 4 RECEPTOR ON STEM CELLS
SPECIFICALLY THEN PERFORM AN
INJURY. AN INJECTION AND THEN
ASSAY STRENGTH SEVERAL WEAKS
LATER AND WHAT WE FOUND WAS THAT
IN THE ABSENCE OF BEING ABLE TO
DETECT THIS SIGNALLING PATHWAY,
THE MICE ACTUALLY GOT WEAKER.
YOU SEE TWITCH FORCE DROP AND
TIM TE TANNIC FORCE DROP. AND
THE CELLS IN IN CULTURE IN THE
ABSENCE OF THIS BARELY
PROLIFERATE. THIS IS A CRUCIAL
PATHWAY IN REGENERATION. AND WE
LOOKED AT A LARGE NUMBER OF MICE
AND WE CAN SEE TWITCH FORCE AND
TE TANNIC FORCE DECLINE. YOUNG
MICE GET WEAKER IF THEY
REGENERATE THEIR MUSCLES IN THE
ABSENCE OF THE SIGNALLING
PATHWAY IN STEM CELLS. WE DID
ANOTHER EXPERIMENT TO LOOK AT
THE SIGNIFICANCE OF THE PATHWAY.
AND HERE WE MADE A DIFFERENT
MASS MODEL WHERE THE
TRANSCRIPTION FACTORS DRIVE.
YOU CAN SEE AFTER AN INJURY IF
WE GIVE THE MICE AN NSAID LIKE
IBUPROFEN WE BLOCK ENDOGENOUS
SYNTHESIS AND THAT LEADS TO A
DECLINE IN STEM CELLS. THEY
CANNOT EXPAND. THEY NEED THE
SIGNALLING PATHWAY TO
PROLIFERATE AND EXPAND AND
ENGRAFT. AND THIS IS ALSO
REFLECTED IN A LOSS OF STRENGTH,
A LOSS OF FORCE, THE YOUNG MICE
GET WEAKER AND THIS WAS PICKED
UP, THIS STORY BY THE NEW YORK
TIMES, BRING ON THE EXERCISE AND
HOLD THE PAINKILLERS. NO PAIN
NO GAIN. BECAUSE WHEN YOU
EXERCISE, WHEN YOU RUN A
MARATHON OR YOU WORK OUT IN A
GYM, YOU ARE DOING DAMAGE TO
YOUR MUSCLES. IT'S A GOOD
DAMAGE, IT'S THE WAY YOU BUILD
MUSCLE BUT YOU ABSOLUTELY NEED
THIS PGE 2 SIGNALLING PATHWAY
AND IF YOU TAKE2 SIGNALLING PATD
IF YOU TAKE AN IBUPROFEN RIGHT
AFTER YOU FEEL ACHY BECAUSE YOU
EXERCISED YOU'RE PROBABLY
NEGATING THE WORK THAT YOU DID
SO WHAT ABOUT THE ROLE OF PGE2
IN AGING. IT WAS NOT CLEAR THIS
WOULD HAVE A BENEFICIAL EFFECT.
UNLIKE THE NICHE WHERE YOU SEE
THE ORDERLY SEQUENTIAL OF CELL
TYPES THE AGE NICHE IS
DYSREGULATED AND YOU SEE THIS
CHRONIC INCREASE IN INFLAMMATORY
CELLS IN PARTICULAR IN
FIBROBLASTS. SO WE WONDERED
WHETHER PGE 2 WOULD HAVE A
BENEFICIAL EFFECT.
WE LOOKED AT THE MUSCLES, YOUNG
AND AGED AND YOU CAN SEE HERE
THE EP 4 RECEPTOR IS PRESENT
ROBUSTLY ON YOUNG MUSCLE STEM
CELLS BUT NOT ON AGED IN THE
MUSCLE TISSUE. THIS IS A CROSS
SECTION OR A LONGITUDINAL
SECTION OF A MUSCLE FIBER. AND
YOU CAN SEE HERE THAT THE
PERCENTAGE OF RECEPTOR POSITIVE
STEM CELLS DECREASES AND THE
INTENSITY OR THE NUMBER OF
RECEPTORS ALSO DECREASES AND
ALSO SIGNALLING BY A TOS TO KREB
IS DECREASED RELATIVE TO THE
YOUNG.
AND IN ADDITION WE DID RNA SEEK
ANALYSIS TO UNDERSTAND THE ROLE
OF THE PGE2 SIGNALLING PATHWAY
AND MY OWE GENESIS, IN YOUNG AND
AGED.
AND WHEN WE DID THAT, WE WERE
ABLE TO SEE TWO TRAJECTORITRAJE
THERE WAS A CYCLING TRAJECTORY
WHERE THE CELLS EXPAND, THEY
PROLIFERATE AND THEIR NUMBERS
INCREASE AND A DIRECT COMMITMENT
TRAJECTORY WHERE THEY
PREMATURELY COMMIT, STOP
PROLIFERATING AND BECOME
DIFFERENTIATED AND COMMITTED
CELLS AND WHAT WE FOUND WAS THAT
THE YOUNG MUSCLE STEM CELLS
PRIMARILY ADOPT THIS SELF
CYCLING PATHWAY WHICH IS THE
REASON THEY BELIEVING REGENERATE
SO EFFECTIVELY BECAUSE THEY CAN
EXPAND AND CYCLE WHEREAS THE AGE
PREMATURELY COMMIT, MORE OF THEM
ADOPT THIS DIRECT COMMITMENT
TRAJECTORY.
AND WHEN WE LOOKED AT THE KINDS
OF MOLECULES THAT ARE EXPRESSED
IN THE CYCLING PATHWAY, PGE2
SIGNALLING WAS ONE OF THE MOST
PROMINENT. YOU CAN SEE THE
ENTIRE CASCADE IS HIGHLY
REPRESENTED. AND THAT IS PART
OF THIS CYCLING TRAJECTORY THAT
IS LOST IN THE AGED AND
REPRESENTED VERY STRONGLY IN THE
YOUNG. THIS IS ALSO REFLECTED
IN THE EPIGENETIC SIGNATURE. WE
DID A SEEK OF THE AGED AND YOUNG
STEM CELLS AFTER EXPOSURE TO PGE
2 FOR JUST TWO HOURS. WHEN WE
WOULD SEE AN EXPANSION OF THEIR
PROLIFERATION.
AND WHAT YOU SEE IS THAT THE
AGED MUSCLE STEM CELLS HAVE OPEN
MOTIFS, CHROMATIN IS OPEN AT THE
AP 1 MOTIF AT THE CBP MOTIF IN
THE EBOXES THAT ARE SO CRUCIAL
ARE CLOSED. AFTER TWO HOURS OF
EXPOSURE TO PGE2 WE FOUND THAT
THE AGE BECOME REJUVENATED.
THAT CREB MOTIF IS OPENED AND
THE AP 1 MOTIF IS SHUT.
THERE'S A DRAMATIC CHANGE IN
CHROMATIN TO REFLECT A MORE
REJUVENATED EPIGENETIC
SIGNATURE. AND THIS IS ALSO
SEEN HERE BY TIME LAPSE. SO
HERE YOU CAN SEE AN ANALYSIS BY
TIME LAPSE. MICROSCOPY AT THE
FUNCTION OF THE AGED MUSCLE STEM
CELLS IN THE PRESENCE AND
ABSENCE OF PGE2 SO THIS GIVES
YOU AN EXAMPLE OF ONE OF THESE
HYDRO GEL MICRO WELLS WHERE
WE'RE MICROWAVES THE STEM CELLS.
AND AND WHAT YOU CAN SEE ON THE
LEFT OF THE SINGLE AGED STEM
CELL EXPOSED JUST TO VEHICLE.
AND ON THE RIGHT EXPOSED TO PGE
2 IT BECOMES READILY APPARENT
THAT YOU HAVE THIS MASSIVE
INCREASE IN CELL NUMBERS.
BECAUSE YOU HAVE MORE
PROLIFERATION AND IN PARTICULAR,
YOU HAVE FEWER CELL DEATH EVENTS
AS SHOWN AT THE BOTTOM HERE. SO
PGE2 IS PROMOTING PROLIFERATION,
SELF CYCLE AND ALSO PREVENTING
CELL DEATH.
LOOK AT THE NUMBER OF CELLS THAT
ARE ACCUMULATING THERE.
AND THIS IS REFLECTED IN THE
TRANSCRIPTOMES. IF WE EXPOSE
STEM CELLS TO PGE 2 FOR 24 HOURS
IF YOU LOOK AT THE YOUNG, THE
TRANSCRIPTOME ANALYSIS FOR THREE
YOUNG, YOU CAN SEE THEY DON'T
DIFFER MUCH BECAUSE THE YOUNG
ARE DOING SO WELL IN THEIR
FUNCTION AND THE AGED HOWEVER,
THERE'S A BLOCK OF GENES THAT
ARE HIGHLY EXPRESSED IN AND
ANOTHER BLOCK OF GENES THAT ARE
DECREASED BUT AFTER EXPOSURE TO
PGE2 YOU NOW SEE A REJUVENATION
OF THIS AGED MUSCLE STEM CELL
TRANSCRIPTOME AND WHEN WE LOOK
BY ANALYSIS THIS IS ALSO
REFLECTIVE THERE. THERE WAS A
NEGATIVE REGULATION OF CELL
DEATH GENES, NEGATIVE REGULATION
OF PROGRAMMED NECROTIC CELL
DEATH. SO THIS MITOTIC
CATASTROPHE IS OVERCOME BY PGE 2
AND THERE'S AN INCREASE IN
SURVIVAL AND SURVIVAL RELATED
GENES. HOW DOES THIS AFFECT THE
CELLS? FUNCTION IS THE MOST
IMPORTANT. I HAVE SHOWN YOU
LOSS OF FUNCTION EXPERIMENTS.
IF WE COINHEKT AGED MUSCLE STEM
CELLS WITH THE PGE 2 WHICH IS A
MORE STABLE FORM OF
PROSTAGLANDIN E 2 IT IS STILL
ONLY IN THE CIRCULATION FOR
THREE HOURS WE COINJECT AND LOOK
AFTER INJURY AT THE BLI SIGNAL
WHICH IS THE MEASURE OF STEM
CELL EXPANSION. HERE YOU CAN
SEE THE CELLS ENGRAPHED AND THIS
IS A LOG SCALE, FAR MORE
EFFICIENTLY AFTER A TRAN CHENT
EXPOSURE TO PGE 2 AND IF WE GIVE
IT A SECOND INJURY THEY FURTHER
INCREASE IN THEIR ENGRAPHMENT
SHOWING THESE ARE STILL STEM
CELLS AND THEIR STEM CELL
POTENTIAL IS PRESENT. THIS
SHOWS ALSO THAT THERE IS A
MEMORY THAT IS INDUCED BY THIS
SHORT-TERM EXPOSURE OF THE STEM
CELLS TO A PGE 2 WHICH IS WHAT
WE SAW REFLECTED IN THE ATTACK
SEEK CHROMATIN SIGNATURE AS
WELL. ANOTHER LINE OF EVIDENCE
WE CAN ALSO SEE THAT PGE 2
ENHANCES THE ENDOGENOUS STEM
CELL REFUNCTION DURING
REGENERATION AND LEADING TO
INCREASED STRENGTH.
IN THIS CASE WE INJECTED THIS
INTO THE MUSCLE OF AGED MICE.
IN THIS CASE, GERIATRIC MICE AND
THANK YOU NIA FOR MAKING THESE
MICE AVAILABLE TO US FOR THESE
STUDIES WHICH HAS BEEN
INVALUABLE TO THESE DISCOVERIES.
AND WE SEE THAT IF WE GIVE A DM
PGE 2 TWO DAYS AFTER INJURY SO
WE'RE ENHANCING THE HEALING
RESPONSE OF PGE 2. ON DAY 14,
JUST TWO WEEKS LATER WE SEE AN
INCREASE IN CROSS-SECTIONAL
AREA, THE SIZE, THE DIAMETER OF
THE MUSCLE FIBERS, YOU SEE A
SHIFT IN THESE DIAMETERS AND
THAT'S REFLECTED HERE ALSO A
GREATER NUMBER IN PAX 7 POSITIVE
MUSCLE STEM CELLS. AND SO
REGENERATION IS ENHANCED,
DECISION WE SEE AN INCREASE IN
MUSCLE MASS OF THE TIBIALIS
ANTERIOR AND IN STRENGTH
MEASURED BY TE TANNIC FORCE AND
IN ABSOLUTE FORCE OR TORQUE.
ENDOGENOUS STEM CELLS RESPOND
ROBUSTLY TO PGE 2 INTRAMUSCULAR
INJECTION LEADING TO INCREASED
SIZES OF THE MUSCLE AND
INCREASED FUNCTION IN TERMS OF
STRENGTH. WELL NOW THIS IS ONE
WAY TO DO DAMAGE SO WE DECIDED
TO LOOK AT A MORE PHYSIOLOGICAL
DAMAGE BY SUBJECTING THE MICE TO
DOWNHILL RUNNING. RUNNING
DOWNHILL ON A TREADMILL AND THEY
RUN FOR TEN MINUTES A DAY FOR
ONE WEEK AND AFTER EACH DAY WE
GAVE THEM A SHOT. THEY RAN FOR
ANOTHER WEEK AND AT THE END OF
FOUR WEEKS WE LOOKED AT THAFR
STRENGTH AND AS YOU CAN SEE HERE
THERE'S A ROBUST INCREASE IN
THEIR TWITCH FORCE AND IN THEIR
TE TANNIC FORCE THAT IS SHOWN
HERE FOR A NUMBER OF MICE.
SO STRENGTH IS ROBUSTLY
INCREASED BY AN ACUTE -- A
SHORT-TERM TREATMENT WITH PGE 2
HAS A LONG-TERM EFFECT IN
INCREASING THE STRENGTH OF AGED
MICE. WE WONDERED WHETHER WE
COULD GLOBALLY INCREASE FUNCTION
WITH PGE 2 INSTEAD OF JUST
INCORRECTING IT LOCALLY. AND
THIS IS WHAT LEAD US TO THE
DISCOVERY OF THE GEROZYME, AND
THIS WORK WAS DONE BY THREE VERY
TALENTED POSTDOCSED A LAY DA AND
WILL WANG. AND WHAT THEY
REASONED WAS THAT MAYBE WE CAN
INCREASE PGE2 LEVELS BY
TARGETING THE DEGRADING ENZYME
WITH PGE 2, 15 PDGH. SO WE
THOUGHT THESE LEVELS MIGHT
DECLINE WITH AGING. WE ANALYZED
USING A VERY SENSITIVE MASS SPEC
METHOD THAT CAN DISTINGUISH
THESE CLOSELY RELATED
PROSTAGLANDINS THAT DIFFER MAYBE
BY A HYDROXYL GROUP AND YOU CAN
SEE HERE THAT THEY DECLINE BY
MAYBE 30% WITH AGING. AND
THAT'S SHOWN HERE RESOLVED BY
MASS SPEC. AND WHEN WE LOOK AT
WHAT MIGHT BE RESPONSIBLE WE
FOUND THAT THE SPECIFIC ACTIVITY
THAT WAS DEGRADING THE ENZYME IS
INCREASED IN MUSCLE IF YOU LOOK
HERE AT AGED VERSUS YOUNG YOU
SEE THAT IT'S INCREASED IN
MUSCLE AND COLON AND SPLEEN AND
SKIN AND HEART. SO IT'S NOT
JUST SPECIFIC TO MUSCLE. IT'S
ELEVATED IN THE NUMBER OF
TISSUES. AND WE SOMEHOW HERE
FOR MUSCLE THAT IT'S INCREASED
AT THE RNA LEVEL. IT'S
INCREASED BY BLOT AND ALSO
SPECIFIC ACTIVITY. IMPORTANTLY
THIS IS NOT JUST A FUNCTION OF
AGED MICE BUT ALSO RELEVANT TO
AGED HUMANS. WE RAN A
MICROARRAY DATABASE AND FOUND
THAT AGED HUMANS ON AVERAGE,
15-PGDH. SOME PEOPLE ARE YOUNG
IN LEVELS AS IS TRUE FOR ALL
MARKERS. BUT ON AVERAGE IT'S
ELEVATED. SO WE REASONED THAT
IF WE COULD TARGET THIS ENZYME,
THE GEROZYME, THAT DEGRADES PGE
2 WE MIGHT BE ABLE TO ELEVATE IT
GLOBALLY AND IN A PHYSIOLOGIC
RANGE. JUST RESTORING IT BACK
TO YOUTHFUL LEVELS.
AND SO WE DID THAT. USING SW WE
TARGETED THE GEROZYME AND HERE
YOU CAN SEE THAT WE RESTORED
PGE2 LEVELS BACK TO YOUTHFUL
LEVELS IF WE INJECTED THE
INHIBITOR. AND DID THIS MAKE A
DIFFERENCE? SO, WELL, WE
INJECTED AGED MICE DAILY FOR ONE
MONTH. AND YOU CAN SEE HERE
THAT THE CROSS-SECTIONAL AREA OF
THE MYOFIBERS IS DRAMATICALLY
INCREASED. THERE'S A SHIFT IN
MYOFIBER SIZES TO LARGER SIZES,
HERE YOU CAN SEE THE
QUANTIFICATION IS A MEAN
CROSS-SECTIONAL AREA
DRAMATICALLY INCREASING AFTER
THIS TREATMENT. AFTER THIS
GLOBAL SYSTEMIC ELEVATION OF PGE
2 LEVELS. DUE TO TARGETING.
AND IMPORTANTLY THIS IS NOT JUST
SPECIFIC TO ONE FIBER TYPE. WE
SEE THAT DIFFERENT FIBER TYPES
THAT HAVE DIFFERENT MYOSIN HEAVY
CHAINS ALSO EXHIBIT THIS
INCREASE IN MY OWE FIBER
DIAMETER.
AND IMPORTANTLY, WE ALSO SEE
THIS REFLECTED IN FUNCTION. SO
IF WE INJECT MICE EITHER WITH
VEHICLE CONTROL OR WITH THIS SW
SMALL MOLECULE INHIBITOR DAILY
FOR ONE MONTH, WE NOW SEE AN
INCREASE IN MUSCLE MASS OF THE
TA BUT WE ALSO LOOKED AS THEY
ALL INCREASE IN MASS
SIGNIFICANTLY. AND WE SEE AN
INCREASE IN STRENGTH COMPARING
THEIR STARTING STRENGTH TO THEIR
STRENGTH AFTER ONE MONTH OF
TREATMENT AND NOW YOU SEE THAT
YOUNG ALSO INCREASE THEIR
STRENGTH EVEN THOUGH THEY HAVE
LESS OF THE ENZYME. THERE'S A
MORE ROBUST EFFECT IN AGING.
AND WE ALSO SEE THAT THERE'S AN
EFFECT IN ENDURANCE, THE TIME TO
EXHAUSTION RUNNING ON A
TREADMILL IS INCREASED AND THAT
SUGGESTS MORE THAN JUST MUSCLE
IS AFFECTED BY ELEVATING PGE 2
SYSTEMICALLY, MAYBE MORE TISSUES
THAN JUST MUSCLE AN AREA THAT
WE'RE VERY INTERESTED IN AND
PURSUING ACTIVELY. TO SHOW THAT
THIS WAS A SPECIFIC EFFECT SINCE
SMALL MOLECULES CAN HAVE OFF
TARGET EFFECTS WE DID AN SH RNA
WE USED A GENE THERAPY APPROACH
TO KNOCK DOWN THE ENZYME USING A
SPECIFIC SH RNA TO 15-PGDH AND
YOU CAN SEE HERE WE KNOCKED DOWN
THE LEVELS OF THE M RNA, THE
SPECIFIC ACTIVITY DECLINE JUST
ENOUGH TO RESTORE LEVELS BACK TO
YOUTHFUL LEVELS JUST LIKE WE SAW
WITH THE INHIBITOR AND WE SAW AS
WITH THE SMALL MOLECULE INHIBIT
AN IN CREASE IN MASS AND
RELATIVE STRENGTH TO BASELINE.
SHOWING THE SPECIFICITY OF THE
SMALL MOLECULE AND THE
SPECIFICITY OF THIS EFFECT FOR
15-PGDH. WE WANTED TO KNOW
WHETHER THIS WAS THROUGH STEM
CELLS SINCE WE'D SHOWN IT HAS A
ROBUST EFFECT ON REGENERATION
WAS THIS DUE TO AN EFFECT ON
STEM CELLS OR WERE THEIR
MICROFIBERS INVOLVED AND WE
FOUND THAT ON THE TUBES ED 4 IS
THE PREDOMINANT RECEPTOR AS IS
STEM CELLS SO IN THIS CASE WE
MADE A TRANSGENIC MODEL WHERE WE
FLUXED THE EP 4 RECEPTOR IN THE
MY OWE FIBER SPECIFICALLY BY
DRIVING THE CRE WHICH IS MUSCLE
KREE TIN CAY NICE WHICH IS
SPECIFIC TO THE MUSCLE FIBERS.
AND AFTER WE O OBLATED THESE.
THEY WERE NO LONGER RESPONSIVE
TO THE SMALL INHIBITOR SHOWING
THAT IN FACT IT IS THROUGH
MYOFIBERS AND IN FACT THIS DRUG
IS A DOUBLE WHAMMY. THE PGE2 IS
ACTING ON BOTH THE STEM CELLS
AND THE MYOFIBERS AND THEN TO
SEE WHETHER THIS IS REALLY A
PIVOTAL REGULATOR AND WHY DO I
CALL IT A GEROZYME AND A PIVOTAL
REGULATOR? I THINK THIS
EXPERIMENT IS THE NAIL IN THE
COFFIN. THE PEACE DERESISTANCE.
WHAT WE DID HERE WAS OVEREXPRESS
PDGH IN YOUNG MOUSE MUSCLES.
USING A GENE THERAPY APPROACH TO
DELIVER THE PDGH WE INJECT IT
INTO THE MUSCLES OF A THREE
MONTH OLD MOUSE AND ONE MONTH
LATER WE ANALYZED THEIR
STRENGTH. YOU CAN SEE HERE
EVIDENCE THAT THE M RNA LEVEL OF
THE ENZYME IS INCREASED AND THAT
THE PGE 2 IS DECREASED BY MASS
SPEC ANALYSIS AND THEN WE LOOKED
AT FORCE AND YOU CAN SEE THIS
DRAMATIC DECLINE IN STRENGTH AND
IN TA MUSCLE MASS AS WELL. SO
THE MUSCLES IN RESPONSE TO
EXPRESSION OF THIS SINGLE ENZYME
ARE SHRINKING AND WEAKENING.
IT'S REALLY QUITE DRAMATIC AND
THAT REALLY IS THE EVIDENCE THAT
THIS IS A PIVOTAL REGULAR. I
NEVER THOUGHT THAT AGING IS SO
PLEA OWE TROPHIC THAT ONE SINGLE
MOLECULE WOULD HAVE SUCH A
ROBUST EFFECT. SO WHAT IS THE
SOURCE OF PDGH IN MUSCLE THAT IS
CAUSING THE DELETERIOUS EFFECTS
OF AGEING TO UNDERSTAND THAT WE
USED CODEX WHICH IS AN IMAGING
APPROACH BECAUSE IT TURNS OUT
THAT IT IS VERY DIFFICULT TO
VISUALIZE PDGH DEFINITIVELY BY
TRADITIONAL METHODS AND THIS
IMMUNO FLUORESCENCE METHOD
ALLOWS YOU TO LOOK AT UP TO 40
ANTIBODIES SIMULTANEOUSLY ON A
SINGLE TISSUE SECTION.
DEVELOPED BY MY NEIGHBOR AT THE
BAXTER LAB AND USES UNIQUE
NON-OVERLAPPING DNA BARCODES
THAT ARE CONJUGATED TO
ANTIBODIES AND THEN SECONDARILY
REVEALED BY FLOUR ROW FORS: YOU
CAN DO THREE ANTIBODIES AT A
TIME.
STAIN THE TISSUE AND THEN YOU
CAN RESOLVE IT BY MICROFLUIDIC
ANALYSIS AND WHO THIS LOOKS LIKE
IS AS FOLLOWS. SO NORMALLY YOU
CAN ONLY VISUALIZE MAYBE THREE
ANTIBODIES AT A TIME BUT USING
CODEX YOU CAN LOOK AT UP TO 40.
HERE YOU SEE A LONGITUDINAL
SECTION OF A MUSCLE. YOU SEE
LAM NAN OUTLINING THE MYOFIBERS.
HERE YOU SEE THE HEAVY CHAIN AND
NOW THE TENDON THAT CONNECTS THE
MUSCLE TO THE BONE.
AND YOU CAN SEE THE MOTOR
NEURONS AND THE JUNCTIONS AND
YOU CAN SEE THE IMMUNE CELLS AND
THE VASCULATURE WHICH IS
EXTENSIVE IN THE MUSCLE AND YOU
CAN LOOK AT INJURED AREAS AND
VERY CLEARLY SEE WHAT THEY ARE.
AND USING THIS ANALYSIS WHICH I
CAN'T DO JUSTICE TO RIGHT NOW
BUT I WANT TO WHET YOUR APPETITE
TO ITS POTENCY YOU CAN USE
NEURAL NETWORK AND MACHINE
LEARNING APPROACH TO ANALYZE
THIS MULTIPLEXED IMAGING AND
SEGMENT THE CELLS, IDENTIFY
UNIQUE FEATURES LIKE ECM
SCAFFOLDS AND SITES OF
REGENERATION AND YOU CAN COMPOSE
AND QUANTIFY THE TISSUE
COMPOSITION OF THE STEM CELLS
OVER TIME AND SPACE AND LOOK AT
CELL-CELL INTERACTIONS, TISSUE
ARCHITECTURE AND VARIOUS
MOLECULES IN A WAY THAT IS JUST
UNPRECEDENTED. AND THIS IS
ALLOWED US THROUGH WILL WANG'S
EFFORTS TO ANNOTATE MULTIPLE
CELL TYPES SHOWN HERE AND YOU
CAN SEE JUST THROUGH THE COLORS
AND THE CHANGES AFTER INJURY
THAT THE NEIGHBORHOODS, THE
CELL-CELL INTERACTIONS ARE
CHANGING OVER THIS TIME COURSE
OF RE GENERATION AND YOU CAN
LOOK AT SPECIFIC CHANGES HERE
THE M 1 MACROPHAGES ARE PEAKING
AT DAY THREE AND THE CELLS ARE
PEAKING AT DAY SIX AND YOU CAN
FIND THEIR NEIGHBORHOODS ARE
CHANGING AND YOU CAN GO INTO
MUCH MORE DETAIL LOOKING AT THE
INNATE RESPONSE, INNATE IMMUNE
RESPONSE, THE ADAPTIVE IMMUNE
RESPONSE AND SUBSETS OF CELLS
AND HOW THEY CHANGE IN THEIR
NEIGHBORHOODS WITH REGENERATION
AND WITH AGING. BUT FOR THE
PURPOSE OF THIS TALK, IT ENABLED
US TO LOCALIZE WHERE THE
GEROZYME IS. AND AS YOU CAN SEE
HERE, IT'S BARELY EXPRESSED IN
YOUNG MUSCLE. IT IS THERE BUT
AT LOW LEVELS BUT IN AGING YOU
SEE IT LOCALIZED IN THESE MUSCLE
FIBERS. IT'S ALSO PRESENT IN
AGED MACROPHAGES, IN THE MUSCLE
TISSUE AND THAT MAY BE THE
SOURCE OF THE PGDH IN OTHER
TISSUES WHERE IT'S ELEVATED WITH
AGING. AND HIGH DOES DR -- HOW
DOES IT WORK? HOW DOES IT HAVE
THIS PROFOUND AFFECT ON MUSCLE?
AND HAVE TARGETING IT, HOW DOES
IT INCREASE MUSCLE FUNCTION? WE
DID AN ANALYSIS AND WHAT YOU
FOUND WHEN YOU COMPARED THE
TRANSCRIPTOME OF THE TWO
TREATMENTS, AGED MOUSE MUSCLES,
YOU CAN SEE THAT THERE'S A DOWN
REGULATION OF UBIQUITIN RELATED
GENES. THESE ARE THE ENZYMES,
THE UBIQUITIN LIGASES THAT
DEGRADE PROTEINS WITH AGING AND
THAT BECOME MORE ABUNDANT.
WE'RE TURNING THEM DOWN. THE
SIGNALLING IS ALSO A PATHWAY
THAT ARISES WITH AGING AND HAS
DELETERIOUS EFFECTS, MY OWE --
YOU CAN SEE AFTER TREATMENT WE
ARE DOWN REGULATING THIS
DELETERIOUS SIGNALLING AND WE
VALIDATED SOME OF THESE MARKERS.
BY QPCR AS WELL AND ALSO SHOWED
THAT THE PATHWAY IS INVOLVED
WITH FOXO AND WE ALSO VALIDATED
WITH THIS. NOT ONLY ARE THESE
PATHWAYS DOWN-REGULATED BY
MITOCHONDRIAL PATHWAYS ARE
UPREGULATED. YOU SEE A ROBUST
INCREASE IN COMPLEX ONE, THREE,
FOUR, FIVE, COMPONENTS OF
MITOCHONDRIAL FUNCTION. AND
ALSO, IF YOU LOOK AT THE MUSCLE
TISSUE I THINK THIS SAYS IT MORE
LOUDLY THAN ANY TRANSCRIPTOME
ANALYSIS IF YOU LOOK AT THE AGED
TISSUE YOU SEE THIS DISORGANIZED
MYOFIBRILS AND DISPERSED BETWEEN
THEM ARE THESE MITOCHONDRIA THAT
ARE VACUOUS AND EXTENDED AND
COMPARE THAT WITH THE TISSUE ON
THE RIGHT WHICH WAS FROM AGED
MICE THAT WERE TREATED FOR ONE
MONTH WITH THE SW SMALL MOLECULE
INHIBITOR PDGH AND WHAT YOU SEE
IS THIS ORDERLY TISSUE NOW AND
THESE COMPACT MITOCHONDRIA AND
THIS RESULTS FROM AN INCREASE IN
BIOGENESIS. WE SEE THAT
REFLECTED IN THE ALPHA
EXPRESSION. ALSO IN NUMBERS OF
MITOCHONDRIA AND THEY'RE MORE
COMPACT, MORE FUNCTIONAL THAN
THEY WERE BEFORE AND THERE'S AN
INCREASE IN ON OF THE GEE WHICH
IS RESPONSIBLE FOR THIS
EXTENSIVE REMODELLING OF THE
TISSUE. THERE ARE MORE AND MORE
FUNCTIONAL. IF WE LOOK AT
VARIOUS CREM CYCLE FUNCTIONS,
THIS GOES DOWN WITH AGING AND IS
RESTORED BY TREATMENT WITH SW 4.
ONE MONTH, THE HIGH DROJ NICE,
DECLINES WITH AGING AND IS
RESTORED AFTER TREATMENT FOR ONE
MONTH AND WE SEE THE MEMBRANE
POTENTIAL ALSO DECLINES WITH
AGING AND IS RESTORED BY THIS
TREATMENT. SO TO SUMMARIZE,
WHAT I'VE SHOWN YOU IS THAT
INHIBITION OF THE PROSTAGLANDIN
DEGRADING THIS INCREASES MUSCLE
STRENGTH IN MICE. SO IN THE
MUSCLE TISSUE THAT'S YOUNG ON
THE LEFT YOU SEE ORDERLY
MYOFIBRILSES AND CONDENSED
MITOCHONDRIA WITH AGING. WE SEE
THE DECREASE IN EXPRESSION AND
WE SEE THE METABOLIZED ACTIVE
FORM AND YOU GET THESE VACUOUS
MITOCHONDRIA AND DISORGANIZED
TISSUE BUT YOU CAN REJUVENATE
THAT TISSUE EITHER BY A SMALL
MOLECULE INHIBITOR OF 15-PGDH
AND THAT LEADS TO AN INCREASE IN
PGE 2 LEVELS. AND YOU SEE THE
SIGNALLING DECLINE. AND THE
MITOCHONDRIA BIOGENESIS
INCREASES. THIS IS REALLY
CRITICAL FOR THE REGENERATION
AND REJUVENATION OF MUSCLE. AND
WE THINK THAT ITS POTENCY
DERIVES FROM ITS DUAL TARGETS.
PG 2 REJUVENATES AND REPLENISHES
THE FUNCTION OF AGED MUSCLE STEM
CELLS.
SO IT TARGETS THE STEM CELLS TO
PROMOTE REGENERATION. IT'S PART
OF THIS ESSENTIAL INFLAMMATORY
PROCESS, THE BODY'S NATURAL
HEALING MECHANISM AND PGE 2 IS
REQUIRED AND EFFICIENT FOR THE
STEM CELL TO PROLIFERATE AND
SURVIVE AND ENDRAFT. IN
ADDITION PGE2 REJUVENATES THE MY
OWE FIBER FUNCTION AND WITH
AGING, THIS ENZYME, THIS
GEROZYME INCREASES IN
EXPRESSION.
AND AS I HAVE SHOWN YOU IT'S A
DETERMINATE OF MUSCLE AGING.
IT'S A NEW HALLMARK OF AGED
MUSCLES. A MASTER REGULATOR OF
MUSCLE AGING IN THAT IF YOU OVER
EXPRESS IT IN YOUNG, THE YOUNG
MICE BECOME WEAKER AND THEIR
MUSCLES BECOME SMALLER. AND IF
YOU INHIBIT THIS GEROZYME, JUST
PHYSIOLOGICALLY MODULATING IT
BACK TO A YOUTHFUL LEVEL IN
RESTORING PGE 2 LEVELS YOU
REGAIN STRENGTH IN ONE MONTH,
15% INCREASE IN STRENGTH.
IN AGED MICE. IF THIS TRANSLATE
TO HUMANS, IT WILL BE SUPER
EXCITING BECAUSE HUMANS LOSE
GREATER THAN 50% -- THEY LOSE --
AFTER AGE 50, 10% OF YOUR MUSCLE
MASS PER DECADE. SO WE
POSTULATE THAT THIS TARGETING OF
15-PGDH COULD BE A THERAPEUTIC
STRATEGY DUE TO IMMOBILIZATION,
AFTER PROLONGED BEDREST SEYDOU
TO COVID OR INJURY OR,
SARCOPENIA, MUSCLE WASTING WITH
AGING AND WITH THAT, I WANT TO
THANK YOU FOR YOUR ATTENTION. I
WANT TO ACKNOWLEDGE THE SUPER
PEOPLE I HAVE IN MY LAB.
FROM DIFFERENT COUNTRIES AND
DIFFERENT BACKGROUNDS,
MULTIDISCIPLINARY GROUP WHO HAVE
MADE THIS POSSIBLE AND MY
FUNDING SOURCES. AND THE NIA
FOR FUNDING AND FOR THE
PROVISION OF THESE AGED MICE
THAT MAKE THIS WORK POSSIBLE.
THANK YOU SO MUCH.
>>THANK YOU SO MUCH, DR. BLAU.
BEAUTIFUL PRESENTATION,
FASCINATING WORK. WE DO HAVE A
FEW QUESTIONS BUT ONLY A FEW
MINUTES SO I WILL JUST START AT
THE TOP. WE'LL MAYBE BE ABLE TO
ANSWER ONE OR TWO OF THESE. THE
FIRST QUESTION WE GOT WAS GOING
BACK TO THE BEGINNING AND
LOOKING AT THE STIFFNESS
STUDIES AND THE QUESTION IS DO
YOU KNOW WHAT WAS LOST OR GAINED
IN THE MUSCLES THAT WERE TOO
STIFF OR TOO SOFT. DID THEY ALL
FAIL OR DID THEY ALL FAIL TO
PROLIFERATE?
>>YES. THEY FAILED TO
PROLIFERATE. THEY TURN ON
SIGNALLING PATHWAYS THAT ARE
DELETERIOUS TO ENGRAPHMENT.
THEY SIMPLY DON'T EXPAND OR
REGENERATE THE TISSUE.
>>AND SOMEONE ELSE ASKED,
TALKING ABOUT THE EFFECTS OF
IBUPROFEN SPECIFICALLY DO YOU
KNOW IF METFORMIN HAS A SIMILAR
INHIBITOR EFFECT THAT IBUPROFEN
HAS AND FOLLOWED UP TO ASK HOW
LONG IBUPROFEN IS -- HOW LONG
THE EFFECTS LAST ONCE YOU TAKE
IT? PRESUMABLY AS A PILL AS A
HUMAN.
>>YEAH, PEOPLE ALWAYS ASK ME
THAT, HOW LONG DO YOU HAVE TO
WAIT AFTER EXERCISING UNTIL YOU
CAN TAKE THIS PAIN RELIEVER IN
AND WE REALLY DON'T KNOW AND
ALSO EXTRAPOLATING TO HUMAN WE
NEED TO DO HUMAN STUDIES TO
TOTALLY UNDERSTAND THIS BUT IT'S
JUST A CAUTIONARY NOTE THAT THIS
PATHWAY IS SUPER IMPORTANT TO
THE FUNCTION OF YOUR MUSCLES.
YOUR MUSCLE FIBERS, YOUR MUSCLE
STEM CELLS AND THAT INHIBITING
THE PATHWAY IS PROBABLY NOT A
GOOD THING, LIKE DAILY ASPIRIN
FOR INSTANCE THAT HAS BEEN
PRESCRIBED BUT IS LESS
PRESCRIBED NOW FOR MAINTAINING A
HEALTHY HEART FOR INSTANCE I
THINK PEOPLE ARE REVISITING
THAT. SO IT'S, YEAH, SOMETHING
TO USE IN MODERATION.
>>SURE. AND DO YOU KNOW IF --
IS AN OVERLAP WITH METFORMIN.
DO YOU HAVE ANY IDEA OF THE
PATHWAYS, IF THEY ARE THE SAME
PATHWAYS?
>>I DON'T BELIEVE THEY ARE.
>>OKAY. SO THIS FINAL QUESTION
IS HERE IS COULD THE 15-PGDH
BLOCKADE HAVE ANY EFFECT ON
NEUROGENERATIVE DISEASES
INCREASED FROM A MONOAGING
IMMEDIATOLOGY?
>>THAT IS SOMETHING WE'RE
ACTIVELY INVESTIGATING. BECAUSE
WITH AGING, YOU LOSE
NEUROMUSCULAR CONNECTION. YOU
LOSE YOUR NEUROMUSCULAR
JUNCTIONS. DINNER VAGUS IS A
BIG PART OF MUSCLE FUNCTION LOSS
WITH AGING AND OF COURSE
ASSOCIATED WITH VARIOUS MUSCULAR
DYSTROPHIES. IN PARTICULAR
SPINAL ATROPHY. YOU LOSE THIS
CONNECTIVITY. WE'RE INTERESTED
IN ACTIVE LY PURSUING WHETHER
THIS CAN COUNTER THE JUNCTIONS
AND ENHANCE THE NEUROMUSCULAR
FUNCTION. THAT IS AN EXCELLENT
QUESTION.
>>AND I HAVE A QUICK QUESTION
THAT'S PERSONAL, SO ONE OF THE
THINGS IN THE FIELD THAT PEOPLE
ALWAYS TALKED ABOUT IS TRYING TO
SCALE UP MUSCLE STEM CELLS AND
BEING ABLE TO USE THEM AND OF
COURSE USING THE PROPER
STIFFNESS IN CULTURE. IS
THIS -- I GUESS THE QUESTION IS
IS THIS SCALEABLE AT ALL? WILL
WE BE ABLE TO MAKE QUANTITIES OF
THIS FOR TRANSPORTATION?
>>YES, IT IS SCALEABLE AND I
THINK IT WOULD BE POSSIBLE. NOT
OBVIOUSLY THROUGHOUT THE BODY
BUT FOR LOCALIZED TREATMENT FOR
STRENGTHENING MUSCLES, IN A
LOCALIZED WAY. I THINK IT'S
QUITE REASONABLE TO THINK THIS
COULD BE FLUENT. YES.
>>AND I DO HAVE TO REITERATE
THE CME NUMBER BEFORE ANYBODY
LEAVES IS 44442. AND I HAVE A
FINAL QUESTION HERE THAT IS I
THINK IS GREAT. THE QUESTION
WAS HOW DO YOU STAY SO
PASSIONATE AND EFFECTIVE THROUGH
YOUR CAREER?
>>YOU JUST HAVE TO LOVE WHAT
YOU'RE DOING AND I DO. AND I --
PART OF THE THRILL IS BRINGING
PEOPLE TOGETHER FROM DIFFERENT
COUNTRIES, DIFFERENT
DISCIPLINES, AND THINGS HAPPEN
WHEN YOU HAVE AN ENGINEER
SITTING NEXT TO AN ARTIFICIAL
INTELLIGENCE EXPERT AND HELPING
PEOPLE REACH THEIR FULL
POTENTIAL. I LOVE TRAINING AND
TEACHING AND THE THOUGHT THAT
SOMETHING THAT WAS DEVELOPED,
I'VE SPENT MY ENTIRE CAREER
STUDYING FUNDAMENTAL QUESTIONS
OF NUCLEAR REPROGRAMMING AND HOW
THAT HAPPENS AND STEM CELL
FUNCTION. I'M PARTICULARLY
EXCITED NOW THAT THIS MAY BE
TRANSLATABLE. THAT WE --
SOMETHING IN MY LAB MAY ACTUALLY
BENEFIT PEOPLE AND BECOME A DRUG
AND THAT IS VERY MOTIVATING.
AND I WANT TO UNDERSTAND HOW IT
WORKS. IT'S LIKE A GIFT TO FIND
SOMETHING THAT'S COMPLETELY NEW,
NO ONE EVER STUDIED THIS ENZYME
AND ITS UPREGULATION WITH AGING
AND THERE'S SO MUCH TO DISCOVER.
IT'S UNCHARTED TERRITORY AND
THAT MAKES ME VERY EXCITED.
>>I THINK EVERYBODY IS VERY
EXCITED AFTER LISTENING TO THE
PRESENTATION. I WOULD ENCOURAGE
ANYONE TO FOLLOW UP WITH YOU
WITH E-MAIL IF THERE ARE
QUESTIONS ABOUT THE PRESENTATION
AND IF THEY ARE INTERESTED IN
WORKING FOR THE LAB. I KNOW THE
NIH IS A RICH RESOURCE FOR
POSTDOCS. THANK YOU VERY MUCH
FOR THIS TALK. IT'S BEEN AN
HONOR AND WITH THAT I SAY THAT
THIS IS THE END OF THE WALS FOR
THIS WEEK AND THANKS, EVERYONE,
FOR JOINING.
>>THANK YOU.