NOKAY, GOOD AFTERNOON, EVERYONE. CAN YOU HEAR ME OKAY.
GREAT, WE'LL GIVE A COUPLE
MINUTES FOR THE LAST FEW PEOPLE
TO COME IN AND FIND THEIR SPOTS.
WELL, GOOD AFTERNOON, EVERYONE,
WELCOME TO THE CLOSE DATE OF
SPRING, SOMETHING TO CELEBRATE
AS WELL AS OUR WARK LS LECTURE
TODAY, I'M WITH THE HUMAN
IMENETTIC BRANCHES AND I AM HERE
TODAY TO BRUCE DR. CHRISTOPHER
WALSH.
HE'S AN INVESTIGATOR AT THE
HOWARD HUGHES MEDICAL INSTITUTE
AND AS WE WILL SEE TOGETHER,
TODAY, THE WALSH LAB ACHIEVES A
EXQUISITE LABORATORY SHEDDING
LIGHT ON HOW OUR BRAINS EVOLVE
AND AGE AND THROUGH THIS BETTER
BED UNDERSTANDING NEUROLOGY AND
PSYCHIATRY, AND HE'S RECEIVED
NUMEROUS AWARDS SUCH AS THE
AMERICAN NEUROLOGICAL
ASSOCIATION, AMERICAN EPILEPSY
ASSOCIATION AND THE ACADEMY OF
MEDICINE, DR. WALSH COMPLETED
HIS MD-Ph.D., AND AFTER A
NEUROLOGY RESIDENCE HE COMPLETED
RESEARCH FELLOWSHIP AT HARVARD
GENETICS MEDICAL SCHOOL, HE HELD
A BLOOD PROFESSORSHIP AT HARVARD
SINCE 1999 AND YOINED CHILDREN'S
AS CHIEF OF GENETICS IN 2006.
DR. WALSH'S CLINICAL RESEARCH AT
BOSTON CHILDREN'S IS DEEPLY
ROOTED IN TEAM SCIENCE AND
COLLABORATION WITH FAMILIES AND
THIS WORK IS IDENTIFIED GENETIC
CAUSES FOR HUNDREDS OF CONKIGZS
IN NEUROLOGY AND PSYCHIATRY AND
DEVELOPMENTAL DISORDERS AND AS
WE HEAR ABOUT TODAY HAS EXTENDED
INTO BRAIN AGING AS WELL EMPLOY
AND IN SEEKING TO UNDERSTAND
MECHANISMS OF GENETIC DEC,
DR. WALSH AND HIS LAB HAVE
TACKLED SOME OF THE DEEPEST
BASIC QUESTIONS IN BRAIN
DEVELOPMENT AND AGING.
BODY EVOLUTIONARY AND
DEVELOPMENT PROCESSES ACCOUNT
FOR THE FOLD OF OUR CORTICALE
SHEETS, WHAT ARE THE LINEAGE
RELATIONSHIPS THAT CONNECT CELLS
OVER THE COURSE OF BRAIN
DEVELOPMENT AND HOW CAN WE USE
THESE LINEAGES TO TELL US ABOUT
THE PATTERN OF OF BRAIN
ORGANIZATION IN THIS.
AND THE TOOLS THE WALSH LAB USED
TO ADDRESS THESE QUESTIONS OPENS
UP NEW FIELDS OF BIOLOGY,
RESEARCH AND THE REWRITING OF
SOME TEXTBOOK PARAGRAPHS AS
WELL.
AND THE WALSH LAB HAS IMPACTED
PAPERS AND THE FIELD BUT LARGE
COHORTS WHO ARE INDIVIDUALLY
TRAINED AND GO ON TO CONTINUE
THE WORK IN THEIR OWN LABS.
SO AS I'M SURE YOU CAN, WE'RE IN
FOR A REAL TREAT TODAY, SO
BEFORE I HAND IT OVER TO
DR. WALSH, I WANT TO LET YOU
KNOW ABOUT A FEW HOUSEKEEPING
THINGINGS.
YOU CAN SUBMIT QUESTIONS THROUGH
THE SEND LIVE FEEDBACK OPTIONOT
VIDEOCAST PAGE AND TODAY'S CME
CODE IS 50117.
50117.
SO WITH THAT PLEASE JOIN ME IN
WELCOMING OUR WALS SPEAKER TODAY
DR. CHRIS WALSH.
[ APPLAUSE ]
>> THANK YOU VERY MUCH AND FOR
THE INVITATION TO COME HERE AND
IT'S A REAL THRILL WHEN I LOOK
AT THE LIST OF OTHER PEOPLE WHO
HAVE GIVEN THE WALS LECTURES AND
IT'S GREAT, OF COURSE TO VISIT
WASHINGTON.
I GOT A CHANCE TO SEE THE CHERRY
BLOSSOMS, ALTHOUGH FROM THE BACK
SEAT OF A SPEEDING TAXICAB, BUT
ANYWAY, IT'S GREAT TO BE HERE.
SO OUR LAB HAS BEEN INTERESTED
FOR A LONG TIME IN USING --HUMAN
GENETICS TO UNDERSTAND THE
BIOLOGY OF HOW THE HUMAN BRAIN
DEVELOPMENTS AND JUST FOR THOSE
MIGHT NOT BE NEUROSCIENTISTS, I
WANT TO REMIND YOU THAT THE
CELLS IN THE CEREBRAL CORTEX,
THE NEURONS ARE NONDIVIDING
CELLS, AND SO THEY ARE FORMED
DURING FETAL GUESTATION AND SO
WE THINK OF THEM AS BEING BORN,
ON A PARTICULAR DAY WHEN THEY
UNDERGO THEIR CELL DIVISION AND
BECOME PERTINENTLY POST MITOTIC
FOR LONG.
LET ME WORK ON THE POINTER
EMPLOY YOU CAN SEE THE THAT DNCH
LAYERS ARE BORN IN SEQUENCE SO
THESE ARE FIRST WORN 1S AND
THESE ARE THE LAST 1S BORN GIVE
THE PRECURSORS.
SO THE 8 BILLION PEOPLE ON OUR
PLANET IS A MUTE O GENESIS FOR
EVERY REQUIRED YEEN THAT'S
REQUIRED FOR THAT PROCESS, BUT
TODAY I WILL TALK ABOUT
MUTATIONS THAT OCCUR, THAT
REGULATE THAT DEVELOPMENT BUT
THAT OCCUR ACTUALLY DURING THAT
DEVELOPMENT AS WELL, AND SO
THESE ARE MUSEUM SWRAIIC
MUTATIONS OR SOMATIC MUTATIONS
AND THEY OCCUR ACTUALLY WITH
EVERY CELL DIVISION THAT
GENERATES THE EMBRYO.
SO WHENEVER THE GENOME IS
COPIED, THE COPY IS NEVER AS
GOOD AS THE ORIGINAL AND THERE
WERE ALWAYS A COUPLE POINT
MUTATIONS INTRODUCED BY THAT AND
OCCASIONALLY THINGS LIKE LINE
ELEMENT TRANSPOSSESSIONS OR COPY
NUMBER VARIANTS SO THESE OCCUR
WITH EVERY CELL DIVISION THAT
GENERATES THE EMBRYO THAT THEY
CAN OCCUR EARLY LIKE THIS RED
MUTATION BEFORE GASTROALATION,
IN WHICH CASE THEY WOULD BE
PRESENT IN ALL TISSUES BUT ONLY
IN A FRACTION OF THE CELLS IN
ANY TISSUE.
THEY CAN OCCUR AFTER
GASTRULATION, LIKE THIS YELLOW
MUTATION AND TYPICALLY WOULD BE
IN A SMALLER CELL IN THE BRAIN
THAN IF IT HAD OCCURRED EARLIER
OR THERE CAN ACTUALLY BE
EXAMPLES OF MUTATIONS THAT ARE
IN 1 HALF THE BRAIN AND NOT THE
OTHER IN THE GREEN MUTATION OR
EVEN A SMALL REGION OF THE
BRAIN.
SO AT THE END OF THE TALK, I
WILL TELL YOU ABOUT SOMATIC
MUTATIONS THAT CAN BE EMILY THED
TO 1 SINGLE DIVIDING NEURON.
AND I'M THRILLED THAT SOME OF
THIS WORK HAS BEEN SUPPORTED
NOW, BY THE COMMON FUND OF NIH
THROUGH THE SMART CONSORTIUM,
THE SOMATIC MUTATION ACROSS OR
AS WE CALL IT IN BOSTON THE
SMART CONSORTIUM.
SO THESE MUTATIONS HAVE BEEN AN
OBSESSION WITH US FOR THE LAST
10 WREERS AND THEY CONTRIBUTE TO
A GROWING NUMBER OF NEUROLOGICAL
AND PSYCHIATRIC DECS AND I WILL
TELL YOU ABOUT SOME OF THEM OVER
THE COURSE OF THE NEXT 45
MINUTES OR SO.
I WILL TELL YOU BRIEFLY ABOUT
SOMATIC ACTIVATING MUTATIONS IN
THE PEDIATRIC EPILEPSY AND I
WILL TALK ABOUT NEWER WORK, MOST
OF IT UNPUBLISHED, ABOUT
TEMPORAL LOBE EPILEPS EXPE THEN
SOMATIC TUMOR SUPPRESSOR
MUTATIONS OUT IN THE MICROGLIA
AND THE ALZHEIMER BRAIN AND THEN
AT THE END, I WILL TALK A BIT
ABOUT THESE SOMATIC MUTATIONS
THAT ARE LIMITED TO A SINGLE
NEURON.
SO REALLY A LOT OF OUR WORK ON
THESE SOMATIC MUTATIONS STARTED
BECAUSE OF THE INTEREST OF AMP
DURANNIA, AND WANTED TO
UNDERSTAND WHAT WAS GOING ON IN
THE BRAIN OF THIS YOUNG BOY WHO
HAD 1 HEMISPHERE, THE RIGHT
HEMISPHERE, ALTHOUGH
RADIOLOGISTS LIKE TO MESS US UP
BY SHOWING IT ON THE LEFT SIDE,
AND THAT ABNORMAL HEMISPHERE AND
OVERGROWN AND DOESN'T SHOW GOOD
DISTINCTION OF THE NORMAL GRAY
MATTER AND WHITE MATTER AND IT'S
INTENSELY EPILEPTIC SO THIS
CHILD HAD INTRACTABLE EPILEPSY
STARTING AT THE TIME OF BIRTH
AND LEFT SIDED WEAKNESS BECAUSE
THAT RIGHT HEMISPHERE EVEN
THOUGH IT WAS BIG, IT WAS NOT
DOING MUCH GOOD.
SO IN A DESPERATE ATTEMPT TO
CONTROL EPILEPSY, NEUROSERNLGONS
REMOVED HIS ENTIRE RIGHT SPHERE,
SO HERE YOU SEE SIGNERAL FLUID
AND EVERYTHING DOWN THE THALAMUS
HAS BEEN REMOVED.
THIS WAS LIFE SAVING, HE HAD NO
SEIZURES FOR 6 YEARS, THEY WERE
CONTROLLED, HE LEARNED TO WALK,
TALK, READS AT GRADE LEVEL AND
SO, YOU KNOW HE REALLY GOT HIS
LIFE BACK FROM THIS DRASTIC
SURGERY.
AND HIS NAME, HERE'S HIS
PECTURE, HE THINKS OF HIMSELF,
DANTE, I USE HIS NAME AND
PICTURE WITH HIS PARENT'S
PERMISSION, HE REMAINS A LITTLE
WEAK ON THE LEFT SIDE AND NEEDS
A BRACE IT WALK BUT HE'S DOING
AMAZINGLY WELL, AND SO, HE HAS
A--SO WE POSTULATED THAT THIS
MIGHT BE A MUTATION THAT'S ONLY
PRESENT IN THAT 1 ABNORMAL HALF
OF THE BRAIN AND SURE ENOUGH HIS
MUTATION IS SHOWN HERE,OOSE A
POINT MUTATION IN THE GENE
CALLED AKT 3, IT CREATES A
SPECIFIC AMINO ACID SUBSIDIARY
CONSTITUTION, AT POSITION 17 AND
YOU CAN SEE IN THIS OLD FASHION
TD SANGER TRACE THAT THE BLOOD
CELLS SHOW THE NORMAL SEQUENCE
BUT THE BRAIN SHOWS A LITTLE
EXTRA PEAK AND THAT REPRESENTS
THIS MUTATION BEING PRESENT
ABOUT ABOUT A THIRD OF THE CELLS
FROM THE HEMISPHERE FROM THE
NEUROSURGEONS AND STUDY IN THE
LAB RATOREXPE IT'S ABNORMALITIES
SEPTORS FROM REST OF HIS BODY.
THIS WOULD BE LIMITED TO THE
BRAIN AND HALF THE BRAIN EMPLOY
SO THIS IS A XOAN CANCER
ASSOCIATED MUTATION, ALTHOUGH
AKT 3 IS AN ISOFORM OF AKT WHICH
IS MOSTLY BRAIN SPECIFIC, SO
THIS IS NOT A MAJOR ONCA GENE,
ALTHOUGH THE EXACT PATHWAY
GIVESERAL GUS MUTATION IS A
MAJOR ONCA MUTATION, AND IT'S A
GAIN OF FUNCTION MUTATION OF
THIS KINASE.
AND SO IN THE DECADE OR SO SINCE
THAT, IT'S NOW CONVENTIONAL THAT
THESE OVERGROWTH LESIONS OF THE
BRAIN THAT ARE INTENSELY
EPILEPTIC WHETHER THEY'RE BIG
LIKE DANTE'S OR SMALLER LIKE
THIS LESION, REPRESENT
ACTIVATING MUTATIONS AND THE
VAST MAJORITY OF THESE CASES OF
ACTIVATING MUTATIONS IN THIS 1
BIOCHEMICAL PATHWAY CALLED THE
mTOR PATHWAY, TREATED
SURGEICALLY AND IN FACT THESE
KIDS GENERALLY RESPOND WELL TO
SURGERY WITH MORE THAN HALF OF
THEM BECOMES SEIZURE FREE.
BUT THIS IS--EVEN THOUGH--THE
MUTATIONS THAT CAUSE THIS
CONDITION ARE CLASSIC ONCOGENIC
MUTATIONS, ACTIVATING MUTATIONS
IN PI3 KINASE, ACTIVATING
MUTATIONS IN MTORE OR LOSS OF
REGULATION IN REGULATORS AND
DESPITE THE FACT THESE ARE
ONCOGENIC MUTATIONS, THEY DO NOT
GROW, THEY ARE STABLE AS FAR AS
WE KNOW THROUGHOUT LIFE.
THEY SHOW OVERGROWTH O THEY
SHOULD AN EFFECTIVE CLONAL
SELECTION, A POSITIVE SLOANAL
SELECTION OF THE MUTANT CELLS
AND THEN THE DIFFERENCE IN THE
SIZE OF THE LESION SEEMS TO
REFLECT THE TIMESSA THE WHICH
THE MUTATION OCCURS, THE EXACT
SAME MUTATIONS CAN BE FOUND IN
THESE SMALLER LESIONS CALLED
FOLK O COTTERRAL DISPLASSIAS OR
IN THE LARGER LESIONS AND SO WE
PREE SIEWM IT'S ALL ABOUT TIMING
AND IN FACT, MANY OF THESE SAME
MUTATIONS CAN CAUSE OVERGROWTH
OF NONCNS TISSUES AS DESCRIBED
LIE LES BESECURITIZATION.ER AND
OTHERS THAT CAN CAUSE VASCULAR
OVERGROWTH FOR EXAMPLE.
AND THEN THE OTHER THING TO NOTE
IS THAT THE HIGHER THE VARIANT
FREQUENCY AND THE LARGER THE
LESION IN GENERAL AND THAT ALSO
CORRELATES WITH THE MORE SEVERE
NEUROLOGICAL DISABILITY, EARLIER
ONSET OF SEIZURES AND GREATER
DISABILITY.
THEY ARE ONLY 1 OR 2-CENTIMETERS
IN SIZE AND THEY RESPOND WELL TO
SURGICAL REMOVAL AND THE
MUTATION IS ONLY PRESENT IN
ABOUT WOKNOW% OF THE CELLS SO
IT'S REMARKABLE HOW IRRITATING
THAT VERY, VERY SMALL POPULATION
OF MUTANT CELLS CAN BE, AND
AGAIN, ALSO THE DISCOVERY OF
THESE MUTATIONS HAS PROMPTED THE
REPURPOSING OF mTOR INHIBITORS
DEVELOPED FOR THE TREATMENT OF
CANCER FOR THE USE OF
INTRACTABLE EPILEPSY ALL THE
RESULTS HAVE NOT BEEN QUITE AS
POSITIVE AS WE HOPED AND I ALSO
WANT TO ACKNOWLEDGE ALISSA,
DE'GAMA WHO WORKED ON MANY OF
THESE, AND OTHERS WHO WORKED IN
LABS IN PARIS AND KOREA HAVE
DONE GREAT WORK ON THIS.
SO THAT'S REALLY JUST AN
INTRODUCTION.
NOW I WANT TO TURN TO ADULT
EPILEPSY.
WHAT HAPPENS IN ADULT EPILEPSY?
AND THE MOST COMMON FORM OF FOLK
EPILEPSY IN ADULLS AND MESIAL
TEMPORAL LOBE EPILEPSY, AND IT'S
REFERRED TO AS MEDIAL, I WILL
REFER TO IT AS MTLE, HIPIECE OF
CONTENTERATEY WROTE DUN IT, A
TREATUS CONTRIBUTED TO HIP
KRACTIES, PEOPLE WERE THOUGHT TO
BE POSSESSED BY SPIRITS BECAUSE
THE PRESENTATION OF EPILEPS
SEYMOUR PSYCHIATRIC THAN SAID
NEUROLOGICAL, THE AURAS CAN BE
MEMORIES OR VOICES OR SMELLS,
RATHER THAN CONVULINGSS.
BUT THEA THE AGE OF ONSET IS
TYPICALLY NOT IN CHILDHOOD BUT
IN ADULTHOOD AFTER A LATENCY
PERIOD THAT CAN BE MANY DECADES.
AND THEN, AS I SAID, AFTER THE
AURAS THERE CAN BE SPEECH
ARREST, LOSS OF ATTENTION AND IF
THERE ARE CONVULINGSS, THEY
GENERALLY REFLECT GENERALIZATION
EPILEPSY OR YAWPED THE TEMPORAL
LOBE ITSELF.
THIS ACCOUNTS FOR 2/3RDS OF
ADULT EPILEPS EXPE IT'S NEVER
BEEN EXPLAINED WHY THE TEMPORAL
LOBE OF ALL THE PARTS OF THE
BRAIN ARE PREFERENTIALLY
ASHINGED EMPLOY THOSE POODIATRIC
CONDITIONS I MENTIONED AFFECT
THENY O CORTEX BUT NOT
PARTICULARLY THE TEMPORAL LOBE,
WHERE THE ADULT FORM,
PREFERENTIALLY AFFECTS THE
TEMPORAL LOBE.
AND WE KNOW THAT IT AFFECTS THE
TEMPORAL LOBE BECAUSE IT HAS A
CHARACTERISTIC NEUROPATHOLOGICAL
HALL WACKER, THIS IS CALLED
MESIAL TEMPORAL SCLEROSIS, SO IF
WE SLICE THAT TEMPORAL LOBE, THE
MEDIATE STRUCTURES OF THE
TEMPORAL LOBE REPRESENT THE
HYPOCAMPUS AND THEN THE
LASTERALATISMERAL LOBE
REPRESENTS THE AUDITORY
NEOCORTEX, AND WITHIN THE
HIPPOCAMPUS, PATIENTS WITH
MESIAL TEMPORAL LOBE EPILEPSY,
CHARACTERISTICALLY SHOW A LOSS,
IN THE HORN FIELD OR CA FIELDS
AND YOU CAN SEE THAT NORMALLY
THESE NEURONS STAIN BROWN, FOR
IMMUNE RESILIENCE ACTIVITY AND A
TYPICAL SPECIMEN AND NEURONS IN
THESE REGIONS ARE COMPLOATLY
LOST, AND THIS CAN BE SEEN RADIO
GRAF GRAPHICALLY AS A BRIGHT
SPOT AND IT'S KNOWN THAT
PATIENTS WITH THIS PARTICULAR
PATHOLOGY ASK RADIOLOGY RESPOND
VERY WELL TO TEMPORAL LOBE
REMOVAL.
AND SO THIS IS THE CLASSIC
COMPLEX EPILEPSY.
THERE ARE NO MEN DEALIAN FORMS,
2/3RDS OF PATES WILL HAVE HEAD
TRAUMA OR A SINGLE SEIZURE IN
CHILDHOOD.
INHERITED GENES HAVE BEEN SHOWN
WHETHER RARE OR COMMON HAVE BEEN
SHOWN TO HAVE LITTLE OR NO ROLE
AND YET TEMPORAL REMOVAL HAS
BEEN KNOWN SINCE THE DAYS OF
WIDER PEN FIELD TO PRODUCE
DRAMATIC IMPROVEMENT SO THAT
PROMPTED US TO CHECK WHETHER
SOMATIC VARIANCE MIGHT BE
IMPORTANT IN TEMPORAL LOBE
COMPLEX.
SO WE COLLECTED ALL THE
SPECIMENS WE COULD FIND FROM
BOSTON CHILDREN'S HOSPITAL AND
THEN WE STARTED IN COLLABORATION
WITH CHRIS [INDISCERNIBLE] WHO
WAS IN THE PROCESS OF MOVING
FROM YALE TO MASS GENERAL, AND
HE HAD A LARGE COLLECTION OF
SPECIMENS FROM DENNIS SPENCERS
FROM HIS AND DENNIS SPENCER'S
OPERATIONS THERE, AND WE
PERFORM DEEP WHOLE EXOHM
SEQUENCING SO MUCH DEEPER, MORE
THAN 10 TIMES DEEPER THAN A
TYPICAL COVERAGE YOU WOULD DO TO
LOOK FOR GERM LINE MUTATIONS
BECAUSE THE MOSAIC MUTATIONS ARE
HARDER TO DETECT, THEY'RE ONLY
AT A FRACTION OF THE READS AND
SO YOU HAVE TO GET A LOT DEEPER
READ COVERAGE AND IN FACT, THIS
500 EXOHM SEQUENCING HAS VERY
POOR SENSITIVITY.
EVEN AT THAT DEPTH TO DETECT
SOMATIC MUTATIONS, SO IN THESE
HUNDRED OR SO CASES WE FOUND A
GRAND TOTAL OF 11 MUTATIONS THAT
WERE PREDICTED TO HAVE A
DELETERIOUS EFFECT ON THE
PROTEIN AND YET 10 OF 11 OF
THESE WERE IN THE RAS, RAF MAPK
KINASE PATHWAY AND THEY'RE ALL
ACTIVATING MUTATIONS THAT
INCLUDES CANCER MUTATIONS, RAS,
12, V-AT THE CLASSIC ALLELE AND
ACTIVATING IN NEURO11, THE
NEGATIVE REGULATOR SUCH THAT
THESE ARE ALL PREDICT TO BE
ACTIVATING.
SOPHISTICATEDY THAT SHOWS THAT
RAS MUTATIONS MIGHT BE IMPORTANT
OR IMPORTANT IN SOME CASES, BUT
WE WANTED TO GET A BETTER SENSE
OF JUST HOW FREQUENT THESE
MUTATIONS ARE AND FOR THAT WE
NEEDED MUCH MORE SENSITIVE
SEQUENCING AND WE PERFOR THE
PURPOSED SEQUENCING GREATER THAN
A THOUSAND AND WE DID AN AMAZING
YOB FROM ALL OVER THE WORLD,
FROM PARIS FROM TORONTO, AND
SEQUENCING MORE THAN 500 CASES
AND HERE, WE FIND THAT, ABOUT
40% OF THE CASES HAVE ACTIVATING
MUTATIONS IN THE RAS PATHWAY,
MOST COMMONLY IN PTPN 11 WHICH
ENCODES SHIP 2 WHERE WE SEE A
DOZEN DIFFERENT PATIENTS AND
ANOTHER DOZEN WITH MUTATIONS AT
E76, ANOTHER DOZEN WITH
SUBSTITUTIONS AT P498.
SO MORE THAN A HUNDRED CASES
WITH JUST PTPN MUTATIONS WHICH
IS 15% OF ALL OF THE CASES, ALL
OF THEM ARE MISSENSED, MANY OF
THEM ARE RECURRENT AND MOST OF
THEM ARE KNOWN TO BE ACTIVATING
IN THE CONTEXT OF CANCER OR IN
THE CONTEXT OF NOONAN SYNDROME
WHERE ACTIVATION OF THE RAS
PATHWAY IS IMPLICATED, ANOTHER
HUNDRED CASES HAD ACTIVATED
MUTATIONS IN THE RAS PATHWAY
LIKE RAS ITSELF OR RAS ITSELF OR
PTPN11 OR MAP ITSELF OR BRAF,
AND THAT WAS UNIMON, THIS YIELD
WAS COMPARABLE TO WHAT WE WOULD
FIND IF WE DID A SINGLE
SEQUENCING EXPERIMENT ON THESE
SINGLE CORTICALE FOCUSING
DISPLASSIA, AND YET WHEN THESE
ARE APPLIED YOU CAN RECOVER
ACTIVATING mTOR MUTATIONS IN
80 OR 90% OF THE CASES.
SO WE SUSPECTED THESE ACTIVATING
RAS MUTATIONS MIGHT BE IMPORTANT
IN A VERY LARGE FRACTION OF
TEMPORAL LOBE OF EPILEPSY AND OF
ALL CASES, 3-QUARTERS OF THE
POSITIVE CASES SHOWED SCLEROSIS,
SHOWED NO TUMOR, NO DISPLASSIA,
AND THIS WAS HIGHER IN PATIENTS
THAT HAD NO OTHER PATHOLOGY THAN
IT WAS IN THOSE PATIENTS THAT
ARE DUAL PATHOLOGY, THAT HAD
ADDITIONAL THINGS LIKE A TUMOR
OR DISPLASSIA.
AND SO SOME OF THESE CASES WE
HAVE MATCHED TISSUE FROM THE
HIPPOCAMPUS AND FROM THE
NEIGHBORING TEMPORAL LOBE AND
WHAT WE NOTICED IS THAT IN ALL
CASES, THE VARIANT IS PRESENT IN
A HIGHER FRACTION OF CELLS AT
WHAT WE CALL A HIGHER VARIANT
ALLELE FREQUENCY IN THE
HIPPOCAMPUS THAN IT IS IN THE
NEIGHBORING CORTEX, SO IN THIS
CASE IT'S PRESCRIBINGENT AT A
VARIANTY FERENCEY OF 2 AND HALF
THAT MEANS IT'S IN ABOUT HALF
THE CELLS, DOUBLE THE THAT GIVES
THE CELLS CARRYING THAT AND THEN
IT'S UNDETECTABLE IN THE
NEIGHBORING NEOCORTEX.
AND THE OTHER THING WE NOTICE
SIDE THAT THE WITH THE
CORRELATION EARLIER AT THE TIME
OF SURGERY, CAN YOU SEE HERE A
50 YEAR-OLD FEMALE HAD A VARIANT
ALLELE FREQUENCY OF 1, WE HAD A
10 YEAR-OLD FEMALE, HAD A
VARIANT ALLELE FREQUENCY THAT'S
ABOUT 8, OR MALE, WHO IS
OPERATED ON YOUNGER THAN 10 HAD
A ALLELE FREQUENCY OF ABOUT 30
AND SO ON, SO IT SEEPS JUST LIKE
WITH mTOR, THE LARGER FRACTION
OF CELLS THAT CARRY THE
MUTATION, THE EARLIER THE ONSET
OF THE EPILEPSY AND LIKELY THE
MORE SEVERE THEY ARE.
WELL THE INVOLVEMENT OF THESE
MUTATIONS IN THE HIPPOCAMPUS
CREATES A REMARKABLE SITUATION
BECAUSE UNLIKE THE TEMPORAL,
UNLIKE THE NEOCORTEX WHERE I
TOLL YOU ALL OF THE NEURONS ARE
POST MITOTIC, IN FACT IN THE
HIPPOCAMPUS, SPECIAL OF COURSELY
IN THE GYRUS OF THE HIPPOCAMPUS,
THIS IS THE 1 PLACE IN THE
CORTEX WHERE STEM CELLS PERSIST
THROUGHOUT FETAL GUESTATION AND
THROUGHOUT BIRTH, WHERE NEURONS
CONTINUE TO BE FORMED AT LEAST
FOR A FEW YEARS AFTER BIRTH.
AND IN THE--AT THE PRESENT IN
HUMANS IT'S CONTROVERSIAL
WHETHER THIS POSTNATAL
NEUROGENESIS IS LIFE LONG OR
WHETHER IT PERSISTS FOR A FEW
YEARS BUT THERE'S A CONSENSUS
THAT THERE'S NO DOUBT IT
CONTINUES AT LEAST FOR THE FIRST
FEW YEARS OF LIFE.
AND IN ANIMAL MODELS THIS
HIPPOCAMPAL NEUROGENESIS HAS
BEEN IMPLICATED IN MEMORY,
FORMATION AND CONSOLIDATION, BUT
IT'S ALSO MODULATED BY ALMOST
EVERYTHING, THE ACTIVITY, THE
TREADMILL, TOXINS, SEIZURES,
WHICH INDUCE A WAVE OF WAVE OF
NEUROGENESIS IN THE DENTATE
GYRUS AND MANY OTHER THINGS AND
SO THIS SUGGESTS THE POSSIBILITY
THAT LIFE EVENTS MIGHT ACTUALLY
MODULATE THE RISK OF THE
TEMPORAL LOBE EPILEPSY BY
MODUTING THE PROCESS OF
NEUROGENESIS AND THIS CORTOON
EXPLAINS THE WAY WE THINK ABOUT
IT.
SO CONGENITAL ACTIVATION OF THE
RAS PATHWAY IN NEURONS IS KNOWN
TO BE INHERENTLY EPILEPTIC, AS
IT IS ACTIVATION OF THE PATHWAY
NEURONS, BOTH OF THESE TEND TO
MAKE THE NEURONS THAT CARRY THE
VARIANT INTENSELY EPILEPTIC AND
SO THAT--SO, NEURONS MIGHT BE--A
SMALL CLONE OF NEURONS MIGHT
CARRY AN ACTIVATING RAS MUTATION
AND THIS REP SESENTSA I RISK
FACTOR IN WHAT MIGHT BE PRESENT
IN WHAT GOES ON TO HAVE SEIZURES
BUT THEN IF THERE'S A RISK
FACTOR, THAT WOULD STIMULATE A
WAVE OF PROLIFERATION AND STEM
CELLS THAT CARRY THIS VARIANT
AND ANY SORT OF PROLIFERATION
WILL FAVOR CLONES, THAT HAVE
ACTIVATING CANCER MUTATIONS AND
SO THAT WOULD CAUSE THE RAS
ACTIVATED CLONES TO GROWTH
FACTOR BIGGER THAN THE NORMAL
CLONES.
THAT CREATES A HIGHER GROUP OF
CELLS THAT ARE NOW CARRYING THE
MUTATION AND I JUST TOLD YOU THE
HIGHER THE FRACTION OF CELLS
THAT CARRY THE VARIANT, THE
EARLIER THE ONSET OF SEIZURES
AND THE GREATER THE RISK OF
EPILEPSY, AND SO THIS MODEL CAN
EXPLAIN THE
PREDOMINANTLYLICATION OF
EPILEPSY FOR THE LOBE IN THE
FIRST PLACE BECAUSE OF THE
PHENOMENON OF POST NEURONATAL
GENESIS AND ALSO THE WELL KNOWN
CLINICAL PEARL THAT SEIZURES
BEGET SEIZURES, THAT THE PATIENT
MIGHT HAVE HIS FIRST SEIZURE AT
AGE 18, AND THE NEXT SEIZURE
MIGHT BE 6 MONTHS LATER, OR 6
YEARS LATER OR FOURTH SEIZURE
MAY BE 6 YEARS LATER AND THERE
ARE SOMETHING ABOUT SEIZURES
THAT ARE EPILEAPT GENIC.
WE CAN USE THE TOOLS THAT ARE
DEVELOPED TO LOOK AT CANCER
DRIVER MUTATIONS TO ASK WHETHER
THESE ACTIVATING RAS
MUTATIONINGS ARE UNDER CLONAL
SELECTION IN THE TEMPORAL LOBE,
AND SURE ENOUGH, IN THE
EPILEPTIC BRAIN, THEY ARE AS
SHOWN BY THESE THAT ARE ABOVE
THIS PF.05 SIGNIFICANCE LINE
WHEREAS IN THE NORMAL BREAN THEY
DON'T SHOW STRONG EVIDENT OF THE
POSITIVE SELECTION, WHERE WE'VE
ALSO TAKEN ENGINEERED IPS LINES
THAT HAVE 1 OF THE ACTIVATING
PTPN LISTEN MUTATIONS, WE MIXED
IT WITH THE WILD-TYPE CELLS AND
YOU CAN SEE THAT THEY VERY
QUICKLY OVERGROW THE CULTURE
SOPHISTICATEDY THEY CLEARLY HAVE
A PROLIFERATIVE ADVANTAGE.
SO JUST TO SUMMARIZE, WE THINK
THAT THIS IS--THIS HAS REALLY
IMPORTANT THERAPEUTIC
IMPLICATIONS BECAUSE JUST AS
THEIR mTOR INHIBITORS, THERE
ARE ALSO INHIBITORS OF THE MAP
KINASE PATHWAY THAT HAVE BEEN
DEVELOPED FOR CANCER BUT NOW
THEY ACTUALLY ARE POTENTIAL
APPLICABILITY TO AGAIN, A VERY
COMMON FORM OF ADULT EPILEPSY.
NOW, WE ALSO WANT TO KNOW WHY
THESE NEURONS DIE, SO, TEMPORAL
EPILEPSY IS A DEGENERATIVE
CONDITION, IS THIS DUE TO THE
MUTATION IN THE NEURONS OR DUE
TO THE MUTATION IN THE DPLEEL
CELLS THAT MIGHT KILL THE
NEURONS?
AND WE THINK WE HAVE SOME EFS
THAT THE MUTATION IS--EVIDENCE
THAT THE MUTATION IS ARISING IN
THE NEUROEPITHELIUM BECAUSE IF
WE SORT DIFFERENT SUBTYPES OF
CELLS WE CAN FIND THEM IN THE
NEURONS AND THE DENDRITES AND
ASTRO SIGHTS SO IT'S CLEARLY
PRESENT IN THE NEUROEPITHELIUM
AND WE SUSPECTED THIS IS WHERE
IT'S ORIGIN IS, BUT IT'S AGAIN
PRESENT IN MULTIPLE CELL TYPES
SO WE DON'T YET KNOW WHETHER THE
NEURONS DIED BY SUICIDE OR
WHETHER THEY GET MURDERED.
WE ALSO WOULD LIKE TO FORMALLY
TEST THE SITE THAT EPILEPSY
INDUCES PROLIFERATION IN HUMAN
TEMPORAL LOBE TISSUE AND WE
THINK WE MIGHT BE ABLE TO DO
THAT WITH SINGLE CELL METHODS
THAT I WILL DESCRIBE LATER IN
THE TALK.
SO AFTER FINDING THESE
ACTIVATING CANCER MUTATIONS IN
THE TEMPORAL LOBE AND REALIZING
THEY COULD BE SUCK YECT TO
SELECTION IF THE CELLS UNDERGO
PROLIFERATION, WE WONDERED
WHETHER THIS IDEA OF CLONAL
SELECTION MIGHT BE IMPORTANT IN
OTHER DISEASES, THAT OCCUR LATE
IN LIFE, AND WHERE WE KNOW THAT
THERE IS INFLAMMATION WHICH ALSO
STIMULATES PROLIFERATION, IN
WHICH THEREFORE MIGHT ALSO SERVE
AS A VEHICLE TO SELECT FOR
MUTANT CLONES THAT MIGHT HAVE
CANCER MUTATIONS.
SO 2 BRAVE POST DOCS, AUGUST
CAN
[INDISCERNIBLE] AND THEN
[INDISCERNIBLE] A TALENTED POST
DOCKERS WILL TAIGD A BRAND ANDEE
IF THEY HAD ACTIVATING CANCER
MUTATIONS IN THE CELLS OF
ALZHEIMER BRAIN.
WE TOOK PREFRONT WILL CORTEX
FROM ALMOST 200 ALZHEIMER CASES
AND OVER A HUNDRED AGED CONTROLS
AND WE DID A CANCER PANEL OF 149
CANCER YEENS WHERE WE COULD
DETECT MUTATIONS EACH IF THEY'RE
PRESENT OFTEN IN A FEW 1 OR 2%
OF THE CELLS.
SO WE SEQUENCED IT EVEN DEEPER,
ALMOST 2000 X AVERAGE COVERAGE,
SIMILAR IN AID ALZHEIMERS AND
CONTROLS AND WE FOUND SURE
ENOUGH, THE ALZHEIMER CASES
ACTUALLY HAVE A HIGHER RATE OF
MUTATIONS IN CANCER GENES, THAN
AGE MATCHED CONTROLS.
THE AGE MATCHED CONTROLS HAVE
PLENTY OF THEM BUT ALZHEIMERS
HAS THE STRINGENT PIPELINE WHICH
ELIMINATES CURRENTLY MUTATED
GENES, YOU SEE THAT THE
DIFFERENCES IS THERE 30%
INCREASE ANDOOSE A MORE MODEST
INCREASE IF WE INCLUDE ALL
MUTATED JEEPS ON THE PANEL BUT
ACTUALLY A HIGHER P-VALUE.
AND THIS DRVES IS ROBUST TO
CONTROLLING FOR GENDER AND AGE,
SEQUENCING COVERAGE AND
POSTMORTEM INTERVAL AND TPEERS
THAT ACCUMULATION OF CANCER
DRIVER MUTATIONS IS SOMETHING
THAT HAPPENS WITH AGE BUT IS
ENHANCED IN THE ALZHEIMER BRAND
AND MODALLY ALTHOUGH IT'S
PARTICULARLY ENHANCE, I WANT TO
YOU LOOK AT THE JEEPS THAT ARE
RECURRENTLY MUTATED EMPLOY THOSE
SHOW A MUCH STRONGER ENRICHMENT
COMPARED TO CONTROL.
ALTHOUGH THESE DIFFERENCES ARE
NOT STATISTICALLY SIGNIFICANT
BUT THIS MIGHT BE A WAY OF
THINKING ABOUT HOW THE APOE4
CREATES RISK BY STIMMULING THIS
CLONAL COMPILATION.
SO THIS IS A LIST OF THE MOST
COMMONLY MUTATED JOONS, IT'S NOT
RAS, IT'S NOT mTOR, IT'S GENES
LIKE DNMT3 A AND XLS 1, THESE
ARE YEENS THAT ARE VERY FAMILIAR
BECAUSE THEY'RE CURRENTLY MUTATE
INDEED BLOOD DISORDERS, CLONAL
DISORDERS OF BLOOD, THINGS LIKE
CLONAL HEMEAT O POETICESIS, AND
THAT CONSIST WENT THE IDEA THAT
IN CELLS PARTICULARLY THE
MICROGLIA SHARE SOME COMMON
PHENOTYPE AND LINEAGES WITH
THESE MYELOID CELLS OF THE
BLOOD, AND AND THESE YEENS ARE
MUTATE INDEED ALZHEIMERS AND
AGED CONTROLS BUT MORE COMMONLY
IN ALZHEIMERS THERE ARE MORE
YEENS THAT NOMINALLY HAVE
GREATER NUMBERS OF MUTATIONS IN
ALZHEIMER THAN CONTROL, THIS
DOESN'T SURVIVE CORRECTION FROM
149 DIFFERENT HYPOTHESIS AND IN
ALZHEIMERS WE SEE INDIVIDUALS
THAT ARE SIMULTANEOUS MUTATIONS
OF YEEPS AT THE SAME TIME SHOWN
BY THE ARROW HEADS AND WE HAVE
NOT SEEN THAT IN A SINGLE AGE OF
CONTROL.
AND SO THERE'S--THAT'S ANOTHER
DIFFERENCE THAT IS STATISTICALLY
SIGNIFICANT.
AND THE--BUT WHAT WE FIND IN
ALZHEIMER'S ALSO IS THAT THE
GENES ARE PRESENT IN A LARGER
MUTANT FRACTION SUGGESTING
THEY'RE UNDER POSITIVE EVOLUTION
AREA EXTENSION THAN IN CONTROLS
THIS, IS PARTICULARLY TRUE FOR
TUMOR SUPPRESSOR YEENS AND A
PARTICULARLY FOR THESE 40%
MUTATED YEENS AND I JUST SHOWED
YOU ON THE PANEL AND YOU CAN
DEMONSTRATE THAT THESE MUTATIONS
ARE UNDER POSITIVE SELECTION
UNDER BOTH NORMAL AGED CASES BUT
TO A GREATER EXTEND IN
ALZHEIMERS THAN IN NORMAL AGING
BUT WE THINK OF THIS AS A
PHENOMENON THAT HAPPENS, THIS
CLONAL SELECTION HAPPENS IN
NORMAL AGING BUT IS ENHANCED
ABOUT SOMEBODY ABOUT THE BRAIN
CAUSE ITS TO BE ENHANCED SO WHAT
CARRYING THESE, AND THE YEENS
AND WHAT WE KNEW ABOUT THE
PATHOGENESIS OF ALZHEIMER'S DEC,
OUR TOP SUSPECT WAS THE
MICROGLIA CELLS WHICH ARE FORMED
FROM A MOILOID LIKE PRECURSOR
AND SEPARATES THEM EARLY AND
CONTINUES TO DEVELOP IN THE
BRAIN AND SO XENON TWEPPED A WAY
TO PURIFY THEM OR ENRICH THEM SO
THAT WE CAN GET PRIPERATION
THAT'S 3-QUARTERS OR MORE
MICROGLIAL CELLS AND THIS
MICROGLIAL FRACTION FOR ALL OF
THE PROLIFERATION STIMULATING
MUTATIONS THAT WE TESTED, YOU
CAN SEE THAT IT'S STRONGLY
ENRICHED IN MICROGLIA COMPARED
TO OTHER CELLS, WE CAN'T SAY
THAT IT'S COMPLETELY ABSENT IN
THE OTHER CELL TYPES BUT BECAUSE
OUR SORTING IS NOT PERFECT BUT
CLEARLY THEY SHOW ANYWHERE FROM
HUNDRED FOLD ENRICHMENT AND YOU
CAN SEE THESE MUTATIONS ARE
PRESENT IN A VERY LARGE FRACTION
OF THE MICROGLIA, SO THIS MUTANT
ALLELE FRACTION OR VARIANT
ALLELE FRACTION HERE OF 22%
MEANS BASICALLY THAT MUTATION IS
PRESCRIBING NEBT HALF THE
MICRODPLIA OF THAT PERSON, THIS
1'S PRESCRIBING NEBT 25% OF THEM
AND AND THESE CLONES SEEM TO
TAKE OVER A LARGE FRACTION OF
THE MICROGLIA IN SOME CASES, WE
TESTED WHETHER THESE ARE SHARED
IN THE BLOOD, AND THE 1S WE
TESTED ARE WERE ALL SHARED IN
THE BLOOD ALTHOUGH WE THEN WORK
WITH SID [INDISCERNIBLE] FROM
STANFORD WHO ANALYZED A WHOLE
EXOHM SEQUENCING OF THESE SAME
CASES AND WHAT WE FIND BASICALLY
IS THAT THE VARIANTS ARE SHARED
IN BLOOD AND BRAIN BUT THEN THE
VARIANTS THAT PRESUMABLY
OCCURRED LATER BUT ARE NOT
SHARED IN THE BLOOD, IT'S SHARED
BETWEEN BRAIN AND BLOOD BUT THE
CELLS LOOK LIKE ONCE THEY'RE IN
THE BRAIN GO ON TO DEVELOP
AADDITIONAL MUTATIONS THAT MIGHT
CONTRIBUTE TO THE CLONAL
SELECTION EMPLOY AND SO WHAT'S
THE IMPACT OF THESE MUTATIONS.
SO AGAIN, BY THE ANALOGY TO
CLONAL HEMEAT O PORESIS, IS
THESE SAME EXACT MUTATIONS
DEVELOP IN THE HEMATOPOIETIC
STEM CELLS AND THEY CREATE
MUTANT PROGENY AND AS THOSE
MUTANT PROGENY DEVELOP LARGER
AND LARGER NUMBERS OF MUTATIONS,
THEY DEVELOP AN INCREASINGLY
ABNORMAL PATTERN OF
TRANSCRIPTION EMPLOY THEY
DEVELOP AN INFLAMMATORY SIGNAL
WHICH IS THOUGHT THEN TO BE
TOXIC TO OTHER CELLS AND THIS IS
HOW CLONAL HEMEAT O POETICESIS
IS THOUGHT TO BE THERE FOR
CANCER BUT ALSO HEART DISEASE
BECAUSE IT CREATES AN
INFLAMMATORY ENVIRONMENT THAT
CONTRIBUTES TO MANY--PERHAPS
MANY DIFFERENT DISEASES AND SO,
WE WANT WANTED TO KNOW THEN
WHETHER THESE DRIVER MUTATIONS
IN MICROGLIA ALSO MIGHT INDUCE
AN INFLAMMATORY STATE AND WE
APPROACH THAT IN 2 DIFFERENT
WAYS, FIRST THEY THINKS TO BEN
EBER, I WAS INTRODUCED TO SX
HEAT THEY HAD ALREADY TARGETED
OUR TOP THROW YEENS, DNMT3, AND
TET2, AND ASXL1, AND WE SET TO
COLLABORATE AND THEY
DIFFERENTIATED THESE 2 TO A
MICROTBLEEL STATE AND MEASURED
TRANSCRIPT OME, AND WHAT WE FIND
IS THAT ALL 3 OF THESE GENES
CONTRIBUTE TO ABNORMAL
INFLAMMATORY PATTERNS THAT HAVE
BEEN DESCRIBED IN ALZHEIMER
BRAIN.
IT'S A SUBSET OF MICROGLIA THAT
TAKE ON A VERY INFLAMMATORY
PATTERN OF TRANSCRIPTION AND WE
SEE THAT REPRODUCED NOTABLY BY
DNMT3 AND ASXL1 PROLIFERATIONS
AND WE SEE A SIGNAL STIMULATED
BY ASXL1 AND TET2 AND MAYA IS A
TALENTED POST DOC IN MY LAB WHO
ANALYZED THESE DATA.
AND THIS SHOWS THAT THE
ENGINEERED MICROGLIAL CELLS HAVE
UPREGULATION OF A HOST OF
INFLAMMATORY GENES AND
INFLAMMATORY SIGNATURES, AND
ALSO PROLIFERATION SIGNATURES,
SO THEY'RE VERY--SO THESE
MUTATIONS CREATE A VERY ABNORMAL
TRANSCREPT OHM IN THE MICROGLIA
WHICH IS CONSISTENT WITH THE
TRANSCRIPT OHM THAT'S SEEN IN
LATE STAGE ALZHEIMER'S DEC.
A SECOND APPROACH WE TOOK WAS
ACTUALLY, FOCUSING ON THE BRAINS
THEMSELVES.
WE CAN'T CALL THE POINT
MUTATIONS IN SINGLE CELL RNA SEQ
DATA BUT WE CAN CALL COPY NUMBER
VARIANTS SO MAYA
BASICALLY--THERE ARE COPY NUMBER
VARIANTS THAT CAN DRIVE THE
HEMEAT ON POETICESIS THAT ARE
RECURRENT MUTATED SO WE CAN CALL
THESE MA SWRAIIC CHROMOSOME
ALTERATIONS AND WE DID THIS IN A
SMALL SAMPLE SIZE OF 30
ALZHEIMER CASES AND 30 AGE
CONTROLS.
BUT WE AGAIN, SO WE FOUND THAT
THERE ARE A HANDFUL OF MOSAIC
NOMINALLY LARGER IN AGED
CONTROLS ALTHOUGH THIS IS NOT
STATISTICALLY SIGNIFICANT
BECAUSE OF THE SMALL SAMPLE SIZE
AND AGAIN YOU SEE A VERY LARGE
NUMBER OF MICRODPLIA IN CELLS
COMPARED TO CONTROL AND THE
CELLS THAT CARRY THESE
CHROMOSOME ALTERATIONS ARE AGAIN
MICRODPLIA OR CAPILLARY
ASSOCIATED MACROPHAGES.
AND LESS CONPLEA OLIGO DENDRITIC
CELLROCYTES BUT NOT OPCs OR
NEURONS.
AND AGAIN, THOSE CELLS THAT
CARRY THESE MOSAIC CHROMOSOME
OLTERATIONS AGAIN HAVE THIS
ABNORMAL PATTERN OF
TRANSCRIPTION THAT RESUMABLES
THESE DISEASES ASSOCIATED
MICROGLIA, WE SEE RUP REGULATION
OF MANY YEENS THAT ARE A
COMPONENT OF THE DAM SIGNATURE
AND THEN WE SEE UPREGULATION OF
REGULATORY PATHWAYS SUCH AS
CYTOKINES AND SO ON OR CELL ARRA
RESPONSE TO INTERLEUKIN 4.
SO OUR WAY OF THINKING ABOUT
THIS IS THAT I THINK IT'S
ACCEPTED THAT THE ALZHEIMER
BRAIN IS AN INFLAMMATORY
ENVIRONMENT AND THAT THERE IS
PROLIFERATION OF MICROGLIAL
CELLS AT A HIGHER RATE THAN
NORMAL AND WHENEVER WE SEE
INFLAMMATION AND PROLIFERATION,
THAT WILL DRIVE EVOLUTIONARY
SELECTION IN FAVOR OF CELLS THAT
CARRY ONCA YEENS BECAUSE THOSE
CELLS WERE SURVIVE BETTER AND
WILL PROLIFERATE BETTER THAN
WILD-TYPE CELLS AND SO THAT
PROLIFERATION WILL THEN
INVARIABLY SELECT FOR MUSEUM
ANT--FOR DRIVE MUTANT CLONES AND
THIS CREATES A PHENOMENON WE
CALL MICROGLIAL EXPANSION OR
MICE BUT AGAIN THAT COMES WITH A
COST BECAUSE THOSE HAVE
INFLAMMATORY SIGNATURES THAT
HAVE BEEN SHOWN IN BLOOD CELLS
TO PROMOTE THE DEATH OF THEIR
MAYBORRING CELLS BY SECRETION OF
INTERLEUKINS AND OTHER CYTOKINES
THAT ARE TOXIC TO OTHER CELLS.
SO IN THE LAST 10 MINUTES OR SO
I WILL TELL YOU ABOUT WHAT
HAPPENS TO A NEURON'S GENOME IN
HAD SOME OF THESE CONDITIONS
WITH AGING AND WITH DISEASE AND
PAISK BEE THIS DEVELOPING FROM
ISOLATING SINGLE NEURONS IN THE
BRAIN AND SEQUENCING THEIR
GENOMES AND COMPARING THEM.
WE HAD TO DO THIS BECAUSE THE
CLONAL STRUCTURE OF THE BRAIN
AND SO COMPLICATED THIS GOT US
INTO THE WHOLE AREA OF LOOKING
AT AGING OF SINGLE NEURONS.
SO BASICALLY TAKE SINGLE NUCLEI,
WE SEPARATE NEURONAL NUCLEI AND
PUT THEM INTO SINGLE WELLS YOU
AMPLIFY THE GENOME BY A VARIETY
OF DIFFERENT METHODS THE WAY YOU
MIGHT SEQUENCE YOUR GENOME FROM
YOUR BLOOD DNA AND MIKE AND
RACHEL LED A STUDY THAT WAS
PUBLISH INDEED 2018 WHERE THEY
LOOKED AT A SINGLE NEURONS FROM
A RANGE OF AGES, DWRP FROM
INFANT TO AGED INDIVIDUALS AND
WE WOULD TAKE LIKE 3 OR 4
NEURONS FROM THE PREFRONTAL
CORTEX OF AN INDIVIDUAL AND WHEN
YOU DO THAT TO A NEW BORN, YOU
FIND THAT THERE ARE ABOUT--THERE
ARE HUNDREDS OF SINGLE
NUCLEOTYPE VARIANTS AND POINT
MUTATION, 1 NUCLEOTYPE FOR
ANOTHER, IN THE SINGLE NEURON
COMPARED TO THE GERM LINE OF
THAT SAME PERSON, THEN
REMARKABLY, IN TEENAGERS IT'S
CLOSER TO A HUNDRED, AND IN
MIDDLE AGED INDIVIDUALS, IT'S
1500 AND IN ELDERLY INDIVIDUALS
IT'S MORE THAN 2000.
SO SINCE THEN, THERE ARE BETTER
WAYS AND MORE ACCURATE WAYS OF
AMPLIFYING THE SINGLE GENE OF
NEURONS, THE MDNA METHOD CREATES
AMPLIFICATION BUT RESULTS IN
UNEQUAL AMPLIFICATION IN THE
GENOME AND IN THE ARTIFACT.
CHUCK AT STANFORD DEVELOPED A
LINEAR METHOD CALLED PRIMARY
TEMPLATE AMPLIFICATION WHERE THE
PIECES ARE SHORTER AND GIVES YOU
AMPLIFICATION OF THE GENOME AND
WE FIND WITH THIS METHOD,
AGE-RELATED ACCUMULATION OF
MUTATIONS IS SLOWER INSTEAD OF
23 MUTATIONS PER YEAR, IT'S 17
MUTATIONS PER YEAR BUT IT'S
INKRE TINSIBLELY IBLE--INCREDIBY
LINEAR, AND YOU SEE 17 MUTATIONS
IN THE FIRST OF LIFE AND 17
MUTATIONS FROM THE END OF LIFE,
BUT THERE'S NORMAL VARIABILITY
IN THE INDIVIDUAL PERSON AND
THIS WAS WORK DONE BY JOE
[INDISCERNIBLE] AND MIKE MILLER
AND [INDISCERNIBLE] FROM MY LAB
AND JOE WHO'S IN PETER PARK'S
LAB WAS PUBLISHED A COUPLE YEARS
AGO.
AND THAT WORK HAS NOW BEEN
REPLICATED IN 4 DIFFERENT LABS
USING 5 DIFFERENT METHODS, THIS
ALL FIND JUST ABOUT 17 OR 18
SNVs PER YEAR, THIS IS WORK
THAT USES POST ACES, A STUDY
FROM [INDISCERNIBLE] AT THE
SANGER CENTER USING DUPLEX
SEQUENCING AND AN UNPUBLISHED 1
FROM [INDISCERNIBLE] LAB, I'VE
TAKEN THE LIBERTY OF TAKING THE
POINTS OF THE OTHER PAPER ANDS
PUTTING THEM ON THE SAME PLOT IT
SHOW HIGHWAY INCREDIBLE LOAMACYY
PRACTICESY CISE AND LINEAR THIS
IS WITH MULTIPLE DIFFERENT
METHODS AND HOW IN THE WORLD OF
NONCYCLING NEURONS DEVELOP
DOUBLE STRANDED POINT MUTATIONS,
AND I DON'T KNOW THE ANSWER TO
THAT BUTILE JUST PROPOSE A
PLAUSIBLE MECHANISM BECAUSE I
FIND IT EASIER TO THINK ABOUT IT
AND THAT STARS WITH THE FACT
THAT DNA DAMAGE IS UBIQUITOUS,
IT'S GENERALLY DAMAGED TO 1
STRAND OR THE RECOLLECT OR ELSE
THERE CAN BE DOUBLE STRANDED
BREAKS, AT ANY GIVEN MOMENT
THERE ARE MORE THAN A THOUSAND
SINGLE STRANDED LESIONS IN THE
GENOME, YOU CAN SEE THE
DIFFERENT TYPES HERE AND HOW
FREQUENT THEY ARE.
AND THESE ARE BY A VARIETY OF
DIFFERENT MECH NICHES BUT 1 OF
THE MECHANISMS IS ECCISION
REPAIR BUT THE WAY IT WORKS IS
BY ACTUALLY EXCISING 29 BASE
PAIRS BUT REPAIRING IT BY
REPLICATING THE UNDAMAGED TRAND
BUT IF A CELL HAS 2 LESIONS
WITHIN 29 BASE PAIRS OF EACH
OTHER, IT'S REPAIRING WITH A
BASE PLATE, IT WOULD CREATE 1.
SO EVEN THE NONREPLICATING GENES
ARE REPLICATING.
AND GIIVE THE FREQUENCY OF THE
EVENTS AND THE LOW RATE OF 15 OR
18 PER YEAR, THERE ARE MORE THAN
ENOUGH, YOU CAN PREDICT THERE
ARE MORE THAN ENOUGH TIMES WHEN
YOU WOULD HAVE 2 DIFFERENT
LESIONS WITHIN 29 BASE PAIRS TO
ACCOUNT FOR 1 ANOTHER AND
ACCOUNT FOR WHAT WE SEE.
SO WHAT HAPPENS THEN IN DISEASE,
AND SO MIKE MILLER AND MIKE
[INDISCERNIBLE] WE COLLABORATE
WIDE ALICE LEE'S LAB TO STUDY
SINGLE NEURONS FROM A POSTMORTEM
ALZHEIMER BRAIN EMPLOY WE
FOCUSED ON LARGE NEURONIAL
NUCLEI AND THESE ARE PARAMETRAL
NEURONS WHICH ARE AFFECTED BY
THE KEEZ, AND WE FIND THAT THESE
NEURONS HAVE ABOUT 200 EXTRA
MUSEUM TAIGS COMPARED TO AGE
MATCHED CONTROLS AND THAT'S MORE
OR LESS EQUIVALENT TO THE 10
YEARS OF LIFE, THAT YOU LOSE TO
ALZHEIMER DEC IF YOU FIGURE THAT
YOU ACCUMULATE ABOUT 17 OR 18
MUTATIONS PER YEAR, FOR 10
YEARS.
AND SO WHAT CAUSES THEM.
SO TO DO THAT, WE CAN AGAIN USE
TOOLS TWEPPED FOR THE STUDY OF
CANCER, THAT LOOK AT BASE
SUBSTITUTIONS AND LOOK AT THE 3
BASE PAIR CONTEXT, THE 2
NEIGHBORS BASES WHERE THE
SUBSIDIARY CONSTITUTION OCCURS
SO HERE'S A C TO A CHAIMPLE AND
THERE MIGHT BE AN AOT OTHER SIDE
OF IT SO THIS CREATES 16
DIFFERENT C TO A CHANGES AND
THEN IT LOOKS FOR RECURRENT
PATTERNS OF SUBSTITUTION AND IT
TURNS OUT THAT THINGS THAT
DAMAGE THE GENOME NEVER DO IT IN
A RANDOM WAY, THEY ALWAYS
PREFERENTIALLY AFFECT SOME BASES
AND NOT OTHERS SO THIS IS A
SIMULATED LUNG CANCER GENOME
WHERE YOU SEQUENCING IT AND ALL
THE SOMATIC MUTATION ANDS THEN
YOU SORT THEM INTO RECURRENT
BUCKYS USING NONNEGATIVE MATRIX
FACTORS, SO IN THE SIMULATED
LUNG CANCER THERE ARE SEVERAL
PATTERNS 1 HAS RED C TO T
CHAIMPLES, AND THIS IS CALLED
SINGLE BASE SIGNATURE 1 AND THIS
IS SEEN IN ALL DIVIDING CELLS
AND THIS REPRESENTS EXAMINATION
DURING THE CELL CYCLE.
WELL'S 1 CALLED SIGNATURE 4
WHICH HAS THE PLURIBU C TO A
CHANGES WHICH IS ONLY SEEN SEEN
IN LUNG CANCERS OF SMOKERS, THIS
IS DUE TO DIRECT TOXICITY.
THIS REPRESENTS JUST AGING, IT'S
SEEN IN ALL TUMORS AND IN ALL
TISSUES, AND PROPORTIONAL TO
NOTHING BUT THE AGE OF THE
PATIENT AT THE TIME OF
DIAGNOSIS.
SOPHISTICATED IN NEURONS, WE USE
LETTERS TO REFER TO THEM RATHER
THAN NUMBERS AND AFTER THE FACT,
SAW HOW THEY COMPARED TO THE
CANCER SIGNATURES AND THE AGE
RELATED ACCUMULATION IN NEURONS
IS MAINLY DRIVEN BY A SIGNATURE
A, BUT THIS RESEMBLES VERY
CLOSELY THE SIGNATURE SBS 5
WHICH IS A MYSTERIOUS AGE
RELATED SIGNATURE WHICH IS AGAIN
AS I SAID PROPORTIONAL TO
NOTHING ELSE OTHER THAN THE AGE
OF PATIENT, AT THE TIME OF
DIAGNOSE BUT HERE WE SHOW THAT
THIS IS ACTUALLY COMPLETELY
UCIBOLITTOUS, IT HAPPENS CELLS
THAT UNDER GO CELL DIVISION, AND
WE DID A PAPER ON CARDIO MY O
SITES ALSO ACCUMULATE THIS SBS 5
SIGNATURE AND SO AGAIN, IT MAY
BE CONSIST WENT SOME SORT OF
FAULTY NUCLEOTIDE EXCISION
REPAIR.
AND SO, THEN WHAT HAPPENS IN
ALZHEIMER'S DISEASE, WHAT ABOUT
THESE EXTRA MUTATIONS, WELL, WE
FIND THAT THESE EXTRA MUTATIONS
ACTUALLY REPRESENT A MUTATION
PATTERN WHICH IS RARE IN THE
NORMAL BRAIN WHICH WE CALL
SIGNATURE C AND HAS THE CTO A
CHANGES WHICH ARE RARE IN NORMAL
BRAIN AND WE FIND THAT IN FACT
THE SIGNATURE BEHAVES VERY
DIFFERENTLY THEN THE NORMAL
NEURONAL SIGNATURE, THE NORMAL
NEURONAL SIGNATURE AND VERY
PROPORTIONAL TO GENE EXPRESSION.
IT HAPPENS MORE COMMONLY AND
HIGHY EXPRESSED GENES AND IS
UNCOMMON IN YEENS THAT HAVE LOW
EXPRESSION BUT THIS EXTRA
SIGNATURE IN ALZHEIMERS DOES NOT
SHOW THE SAME RELATIONSHIP AT
ALL.
IT'S NOT PROPORTIONAL TO GENE
EXPRESSION.
AND SO THESE SIGNATURE CANS
IMPLICATE MECHANISMS OF
TOXICITY, WE EXPECT THE C TO A
CHEANCHS MIGHT REPRESENTOX
ILLEGALS GAUNINE BECAUSE THAT
HAPPENS IN CIGARETTE SMOKE AND
YOU CAN SEE THAT THERE'S AN
EXCESS OFOX O GAUNINE, AND IT
INCREASES NORMALLY IN AGE BUT
FURTHER INCREASE INDEED
ALZHEIMER'S DISEASE.
MORE RECENTLY [INDISCERNIBLE]
LOOKED AT FRONTAL TEMPORAL
DEMENTIA AND SPECIFICALLY DO YOU
TO CASES WHERE THERE'S
AMPLIFICATION OF THE C9 RFP3,
AND THAT SHOWS A SIMILAR
PHENOMENON TO ALZHEIMERS, ABOUT
WOHUNDRED EXTRA MUTATIONS AND
WHAT THE SIMILAR PATTERN OF
NUCLEOTIDE SUBSTITUTION EMPLOY
NOW AT THE BETTER TECHNIQUES WE
CAN ANALYZE A SECOND TYPE OF
MUTATION IN NEURONS CALLED
INDELATWALS, SO INDELATWALS ARE
INSERTION OF BASES, TYPICALLY
SHORT A FEW BASE PAIRS OR THE
DELETION OF A COUPLE OF BASES SO
I JUST REFER TO THEM AS
INDELATWALS, OR SOMATIC
INDELATWALS, S-INDELs, AND
THESE ACCUMULATE BUT ALMOST 10
TIMES SLOWER THAN SNVs, ONLY 2
OR 3 PER YEAR AND THEY HAVE AN
EVEN STRONGER RELATIONSHIP TO
TRANSCRIPTION THAN THE SNVs,
SO BOTH INDELs AND SNVs ARE
ENRICHED IN HIGHLY EXPRESSED
YEENS THAT'S AGAIN SHOWN HERE
FOR SNVs AND HERE FOR INDELs
BUT THEY SHOW A STRONGER
ENRICHMENT AND AGAIN, THEY'RE
BOTH STRONGLY ENRICHED AT NEURAL
PROMOTERS AND ENHANCERS BUT
PARTICULARLY THE INDELs,
AGAIN, THE SNVs SHOW
ENRICHMENT AT H3 K27 ACETYLATION
PEAKS.
THE INDELs SHOW A STRONGER
ENRICHMENT, THE SNVs SHOW A
LITTLE ENRICHMENT BUT THE
INDELs ARE VERY, VERY HIGH LE
ENRICHED SO THE INDELS, HAPPEN
WHERE YOU DON'T WANT THEM, THEY
HAPPEN IN INN HANSERS, THEY ARE
ENRICHED IN ENHANCERS AND ENRICH
INDEED ANY FORM OF OPEN
CHROMATIN, SO THEY ARE VERY
DAMAGING AND THESE 2 OR 3
INDELs PER YEAR ARE MORE
DAMAGING THAN THE 15 OR 20
SNVs, ONCE YOU FIGURE WHERE
THEY OCCUR IN THE GENE, WHETHER
THEY OCCUR IN A GENE OR OUTSIDE
OF A YEEN AND WHETHER THEY
ACTUALLY ARE LIKELY TO IMPAIR
THE FUNCTION OF THAT GENE.
SO RECENTLY WORK THAT'S NOT
PUBLISHED YET, WE DISCOVERED, E
FOUND IT BUT DIDN'T KNOW WHAT TO
DO WITH IT.
BOTH ALZHEIMER HYMER AND STD
HAVE A LARGE INCREASE IN THE
INDELs, SO THIS SHOWS AGE
MATCHED CONTROLS AND ALZHEIMER
SINGLE NEURONS AND ALS, FOOTWORK
TD NEURONS AND SOME LOOK NORMAL
AND THIS IS THE LOG PLOT SO THIS
IS 5000 HERE AND THIS IS 500,
BUT YOU SEE SOME NEURONS HAVE
THOUSANDS OF THESE INDELs,
WHICH WOULD BE INCREDIBLY COURT
AND -
-DAMAGING FOR THE PAT
E-PRESCRIBINGS.
SO IF YOU LOOK AT THESE, YOU SEE
A FAIRLY WIDE DISTRIBUTION OF
DIFFERENT TYPES, THESE ORANGE 1S
ARE 1 BASE PAIR DELETIONS, THESE
GREEN PAIRS ARE 1 BASE PAIR,
HAVE YOU 2 BASE PAIR DELETIONS,
AND 2 BASE PAIR IN BLUE AND SO
ON.
IN THESE ABNORMAL 1S, ARE ALMOST
EXCLUSIVELY 2 BASE PAIR
DELETIONS THIS, SHOWS AGAIN THE
REDUCED NORMAL BECAUSE YOU SEE
IN IS THE NORMAL PATTERN AND
THEN SUPER IMPOSED ON THIS IS
THE HUGE SPIKES IN ALS AND IN
ALZHEIMER'S DEC, OF THESE 2 BASE
PAIR DELETIONS THAT OCCUR AT
HAWAIILY RECURRENT PATTERN IN
BOTH--AND A VERY SIMILAR PATTERN
OF ESSENTIA WILYAIN
INDISTINGUISHABLE PATTERN AND
THESE 2 VERY, VERY DIFFERENT
DISEASES.
FOURTH APPEARANCE WE DIDN'T KNOW
WHETHER THESE WERE SINGLE
STRANDED EVENTS THAT WERE JUST A
LESION ON 1 STRAND AND NOT THE
OTHER, OR DOUBLE STRANDED EVENT.
WE SUSPECTED THEY MIGHT BE
SINGLE STRANDED BECAUSE
[INDISCERNIBLE] HAD ALSO STUDIED
ALZHEIMER NEURONS AND HE HAD
SEEN MANY SIMILAR PATTERNS
INDELs BUT HAD NOT SEEN THE
LARGE ACCUMULATION IN INDELs
IN ALZHEIMER DEC EMPLOY HE
THOUGHT THEY MUST BE SINGLE
STRAND BUT IN FACT, DIANE CHOW
ADAPTED THIS METHOD OF TAGGING
THE 2 DIFFERENT STRANDS OF DNA,
WHERE YOU USE TRANSPOSES TO
LABEL THE STRAND, SO IF A
VARIANT IS DOUBLE STRANDED, IT'S
THROUGH ON THE WATSON AND YOU
CAN DO COMPLEMENT, AND YOU CAN
BE SRN THIS IS A TRUE DOUBLE
STRANDED MUTATION, WHEREAS IF
THERE'S ANY SORT OF
AMPLIFICATION ARTIFACT OR ANY
SORT OF POSTMORTEM CHANGE, THIS
WILL BE PRESENT ON 1 STRAND AND
NOT THE OTHER SO CAN YOU FILTER
THESE OUT.
SO WE FIND THESE 2 BASE PAIR
INSERTIONS ARE MOST COMMONLY
SINGLE STRAND BUT THEY ARE
DEFINITELY FREQUENCY DOUBLE
STRANDED AS WELL, SO THIS MAKES
US SO CLEARLY THEY ARE REAL BUT
IN FACT, THIS MAKES US BELIEVE
THAT SINGLE STRANDED EVENTS ARE
LIKELY TO BE A BIOLOGICAL PHENOM
BECAUSE OF THEIR SPECISSITY AND
THE RESEMBLANCE OF THE DOUBLE
STRANDED SIGNATURE.
SO I WILL JUST WRAP UP HERE, THE
NEURONAL GENOME IS INHERENTLY
CHANGING, THE NEURONS GAIN AN
SNV EVERY FEW WEEKS THROUGHOUT
YOUR LIFE AND 2 TO 3 INDELs
PER YEAR IN A LINEAR FASHION
NORMALLY, THE MUTATIONS ARE
ENRICHED IN EXACTLY THE MOST
TRANSCRIBED PARTS OF THE GENOME
AND THEN AD AND ALS BOTH SHOW
INCREASED NUMBERS OF SINGLE
NUCLEOTIDE VARIANTS ABOUT 200
EQUIVALENT TO THE 10 YEARS OF SO
OF AGING THAT IS LOST TO EITHER
OF THESE CONDITIONS BUT PERHAPS
MORE REMARKABLY THEY SHOW LARGE
INCREASES OF HUNDREDS TO EVEN
SOMETIMES THOUSANDS OF INDELs,
AND THESE AGAIN ARE HIGHLY
ENRICHED IN GENES AND THE
MECHANISM WE DON'T YET
UNDERSTAND BUT WE'RE VERY, VERY
ACTIVELY TRYING TO FIGURE OUT
WHAT THE MECHANISM OF THERE ARE
BECAUSE THIS COULD POTENTIALLY
CAUSE WIDE SPREAD CHANGES IN
GENE EXPRESSION THAT MIGHT
ULTIMATELY HAVE SOME
RELATIONSHIP TO THE DEATH OF
THOSE NEURONS.
SO I'LL JUST CONCLUDE THAT THE
WORK BY SOMATIC MOSWRRK ZAIC, I
WILL ILTRAIT THIS WITH
ILITRATIONS WE HAVE 80 BILLION
NEURONS AND GLIAL CELLS
APPROXIMATELILY AND EACH OF
THESE ARE BORN WITH A ABOUT A
HUNDRED SOMATIC SNVs THAT ARE
DEVELOPMENTAL CLONAL 1S FROM THE
CELL THAT OCCURS DURING THE CELL
DIVISIONS THAT GENERATED AND SO
THAT GIVES YOU 8 TRILLION
SOMATIC MUTATIONS JUST IN YOUR
BRAIN NEURONS.
AND OF COURSE, NOW THE GENOME
STARTS LOOKING PRETTY SMALL,
IT'S A MERE 3 BILLION BASE PAIRS
SO 8 TRILLION DIVIDED BY 3
BILLION 2000 TIMES THE AVERAGE
SPOT IN YOUR GENOME IS MUTATED 3
TAMES JUST IN YOUR NEURONS JUST
AT BIRTH TO SAY NOTHING OF THE
AGE RELATED 1S I WAS JUST
TELLING YOU ABOUT.
AND THEN, A SIMILAR CALCULATION
WILL HOLD FOR WHATEVER YOUR
FAVORITE CELL TYPE IS, THE SAME
CALCULATION, HOLD FORS GLIAL
CELLS, TBLEEL CELLS ALREADY HAVE
A MUTATION IN EVERY SINGLE--NOT
JUST EVERY YEEN IN THE GENOME
BUT EVERY NUCLEOTIDE IN THE
GERONTOLOGYSTS MEMORY CLONE AND
IT'S JUST A QUESTION THEN OF
WHETHER THEY'RE UNDER THE RIGHT
SORT OF CLONAL SELECTION, TO
CAUSE THOSE MUTATIONS TO HAVE AN
EFFECT.
AND THIS SIMULATION IS COPIED
FROM BEN EBBER 2 DESCRIBED THIS
FOR 10 BILLION T-CELLS EMPLOY SO
I BELIEVE THAT ANY INFLAMMATION
WILL BREED PROLIFERATION AND ANY
PROLIFERATION WILL BREED A
COMITITION, A CLONAL SELECTION
OF THOSE CELLS THAT THAT HAPPEN
TO HAVE ACTIVATING MUTATIONS
THAT ARE ESSENTIALLY CANCER LIKE
MUTATIONS, BUT, OFTEN TIMES,
THESE CANCER MUTATIONS OCCUR IN
CELLS LIKE NEURONS AND MICROGLIA
THAT DON'T FORM TUMORS, BUT THEY
CREATE ALTERNATE DISEASE STATES
THAT DON'T LOOK LIKE MASSES THAT
YOU CAN TAKE OUT.
SO AGAIN, OTHER MYSTERIOUS
NONNEUROLOGIC DISEASES ARE
LIKELY TO REFLECT OTHER KINDS OF
ROLES OF SOMATIC MUTATION, SO I
TRIED TO ACKNOWLEDGE EVERYONE AS
I WENT.
THE SINGLE AGING NEWON WAS
STARTED BY MIKE MILLER AND THEN
[INDISCERNIBLE] MAYED A MAJOR
ROLE, AND WE'VE BEEN REALLY
LUCKY TO COLLABORATE WITH BRAD
FROM THE MGHAL JEIMER CENTER,
THE TEMPORAL EPILEPSY WORK IS
THE WORK OF [INDISCERNIBLE], AND
I DIDN'T MENTION [INDISCERNIBLE]
IS THE BIOINFORMATICIAN FROM THE
LAB HAD IN WHICH WE DID THIS
WORK, I THINK WE'VE MENINGED ALL
THESE PEOPLE HERE BUT WE'VE BEEN
AGAIN LUCKY TO HAVE THE
COOPERATION FOR THE ROSE MAP
PROJECT AND THEN AS THE FTD ALS,
AND WE WOULD BE NO PLACE WITHOUT
PETER PARK, I WANT SHORTENED
SHOW OUTIO, IN MANY OF THESE
PROGECS AND HE'S LIKE A GENIUS
WHEN IT COMES TO ANALYZING THESE
THINGS, AND LEE, AS WELL,
BRILLIANT PEOPLE IN HER LAB,
THANK YOU VERY MUCH AND I WILL
BE HAPPY TO ANSWER QUESTIONS.
MWE MIGHT HAVE TO REPEAT
THIS--THERE WE GO, OKAY, SO AS
WE'RE WAITING EARLIER QUESTION,
ANY INFORMATION ABOUT THE
EXISTENCE OF THESE MUTATIONS IN
THE POPULATION OF CHILDREN WHO
HAVE EXPERIENCED FIBERAL
SEIZURE?
>> NO, WE DON'T HAVE ANY SPA
SPECIFIC INFORMATION AGAIN WE
CAN ONLY WORK WITH A POSTMORTEM
BRAIN OR A TEMPORAL LOBE
RESECTION.
WHAT WE'RE TRYING TO DO THOUGH
IS TO FIGURE OUT IF THOSE, YOU
KNOW IF OUR PATIENTS THAT HAVE A
HISTORY OF FEB RILE SEIZURES, IF
WHAT I'M SAYING IS TRUE, WE
HYPOTHESIZE THAT SEIZURE WOULD
HAVE INDUCED A WAVE OF NUR O
GENESIS IN THE TEMPORAL LOBE AND
YOU KNOW I MENTIONED THAT THESE
CANCERS ARE VERY SPECIFIC.
AND SON 1 OF THEM IS SPECTACULAR
FOR CELL DIVISION, WHEN I GO
BACK TO THIS LUNG CANCER, THIS
SBS 1, IT'S SEEN ONLY IN
DIVIDING CELLS AND NOT PRESENT
IN NEURONS ISSUES THE NEURONS
HAVE A FEW OF THESE MUTATIONS
FROM THE DEVELOPMENT BUT THEN
THEY DON'T ACCUMULATE THEM WITH
AGE.
HAY ACCUMULATE OTHER THINGS
HOWEVER, WE CAN LOOK IN THE
TEMPORAL LOBE SPECIMENS TO SEE
IF THEY HAVE MORE OF THE NORMAL
NEURONS AND THAT WOULD BE
INDICATOR THEY WOULD GO ARK
DIGGAL ROUNDS OF PROLIFERATION
AND CORRELATE WITH THE HISTORY
OF REFRESHING FACTORS.
>> OKAY, I WILL MOVE ON TO 1
MORE.
IN THE CASES OF CLONAL
PROLIFERATIONS, IN THESE
NEUROLOGICAL DECS DUE TO SOMATIC
VARIANTS, SHOULD THESE CASES
ALSO BE DRIEBED AS BENIGN
NEOPLAZ MIDSISMS.
LET'S SEE IT DEPENDS ON THE
PRECISE DEFINITION OF THE TERMNY
O PLASM, I'M TRYING TO RECALL
WHAT WAS TAUGHT IN PATHOLOGY BUT
THAT WAS 40 YEARS AGO OR 35
YEARS AGO, MY UNDERSTANDING OF A
NEOPLASM IS THAT THEY GROW.
AND SO BY THAT DEFINITION, NO,
BECAUSE AGAIN, PEDIATRIC 1S ARE
FIXED DISORDERS AS FAR AS WE
KNOW DON'T GROW, PROBABLY WILL
FIND OUT SOME DAY THEY ARE
GROWING IN SOME WAYS WHERE THE
OVERALL MASS OR APPEARANCE
DOESN'T CHANGE, PROBABLY A LOT
MORE DYNAMIC THAN I GIVE THEM
CREDIT FAR BUT THEY DON'T
OBVIOUSLY GROW IN THE WAY I
THINK OF AS A NEOPLASM.
>> HI, VERY NICE TALK.
I THINK YOUR EPILEPSY DATA
SUGGESTS BECAUSE OF THE NETWORK
NATURE OF NEURONS, A VERY SMALL
PROPORTION OF AFFECTED NEURONS
CAN HAVE AN OUTSIDE EFFECT
EMPLOY SO I'M WONDER FIGURE YOU
HAVE THOUGHTS AS TO HOW OR
WHETHER THESE SOMATIC MUTATIONS
MAY CONTRIBUTE TO NORMAL HUMAN
DIVERSITY IN EMERGING ITS OF
NEUROCOGNITIVE FUNCTION AND
BEHAVIOR?
>> THANK YOU VERY MUCH FOR THAT
QUESTION.
I THINK VERY LIKELY THEY DO.
IT'S A LITTLE HARD TO KNOW HOW
TO MAKE THAT ARGUMENT, AND THE
REASON I THINK IT'S LIKELY THAT
THEY DO, IS THAT SOMATIC
DEVELOPMENTAL MUTATIONS THAT ARE
CLONEALLY SHARED ARE COMMON
ENOUGH SO THAT A TYPICAL PERSON,
IF WE GO THROUGH THE MAP, A
TYPICAL PERSON WILL CONTAIN A
FUNCTION ALTERING EXONIC SOMATIC
MUTATION IN LIKE ABOUT 2% OF
THEIR CELLS OR MORE.
SO BASIC LYE ALL OF US HAVE A
FUNCTION ALTERING EXONIC
MUTATION AND SOME CLONE IN OUR
BRAIN SOMEWHERE, TO SAY NOTHING
OF 1S THAT MIGHT BE ALSO
FUNCTION ALTERING AND NONCODING
SO, YOU KNOW THERE ARE SO MANY
OF THEM THAT THEY ARE VERY
COMMON AND AS I SAY, ONCE YOU
GET DOWN TO SMALL CLONES, WE ALL
HAVE EVERYTHING, SO I DO BELIEVE
THAT--BUT AGAIN HOW TO CORRELATE
THEM WITH DIFFERENCES IN
BEHAVIOR OR UNIQUE ASPECTS OF
PEOPLE.
AND WHAT'S REALLY COOL IS THAT
THE DEVELOPMENTAL 1S ACTUALLY
ARE ENRICHED IN NONCODING
REGULATORY ELEMENTS, ENHANCERS
AND PROMOTERS.
WHAT'S INTERESTING ABOUT THAT IS
THAT EXONIC MUTATIONS ARE PRETTY
MUCH ALL BAD THE PROTEIN
SEQUENCE OF OF ALL PROTEIN
SYSTEM OPTIMIZED FOR PERFECT
FUNCTION, A MUTATION IS NOT
LIKELY TO TO IMPROVE THE
FUNCTION OF A PROTEIN, ON THE
OTHER HAND IS MUTATION AND AND
SO THEY MIGHT SHIFT THE
EXPRESSION, SORE THEY MIGHT TURN
IT ON SOME PLACE WHERE IT'S NOT
TURNED ON SO THOSE ARE JUST THE
KIND OF MUTATIONS THAT MIGHT
GENERATE FUNCTIONAL DIVERSITY
WITHOUT CREATING DISEASE.
SOIME INTERESTED WHETHERRINE
TIEN'S BRAIN HAD SOME
INTERESTING ENHANCER IN
YOUITATION, AND SOME--SO HAD
SOME GENE TURNED ON, PLACE WHERE
IT MIGHT NOT NORMALLY BE.
>> SURE, SO 2 QUESTIONS.
THE FIRST 1 IS: YESTERDAY I
WENT FOR A 2-MILE WALK WITH A
FRIEND OF MINE, SHE'S ALMOST 98
YEARS OLD, ALMOST NEVER SICK,
SHE EXERCISES AT 8 IN THE
MORNING, ALL THESE GOOD THINGS
AND WHEN I LOOK AT THESE
HORRENDOUS NUMBERS, I ASK
MYSELF, HOW CAN SHE POSSIBLY
AVOID ALL OF THESE DEBILITATING
ITATING
MUTATIONS, REALLY.
SHE'S AMAZING, HOW DOES THAT
HAPPEN.
>> THAT'S A GREAT QUESTION.
I WOULD LIKE TO LEARN THE ANSWER
RIGHT AWAY BEFORE I GET 1 DAY
OLDER.
WHAT FASCINATES ME IN THESE
MUTATIONS IN MICROGLIA, IT'S A
WAY OF INTEGRATING OUR INHERITED
GENOME WITH OUR LIFESTYLE.
SO BECAUSE, YOU KNOW THESE--MANY
THINGS MIGHT, SO WE'RE DOING A
PARALLEL STUDY OF CHRONIC
INSEVERE MITRAL LOP RAGHTY AND
AMERICAN FOOTBALL PLAYERS AND
WITH Mc KEY IN BOSTON ANALYZED
THE BRAINING OF MANY FAMOUS
FOOTBALL PLAYERS, AND SO, WE SEE
SIMILAR PATTERNS OF MUTATION IN
THE GENOMES OF SINGLE NEURONS,
AND WE HAVE IN EVIDENT THAT THEY
ALSO HAVE THESE CLONAL
SOPHISTICATED MOTTIC EVOLUTION
AS WELL, AND SO, YOU CAN IMAGINE
THAT--SO LIFESTYLE CHANGES OR
HEAD TRAUMA MIGHT INDUCE
IMFLAMMATION IN THE BRAIN AND
AGAIN, THAT WOULD THEN STIMULATE
PROLIFERATION OF THESE CELLS SO
THAT'S A MECHANISM, HOW THESE
LIFE TILE EVENTS MIGHT INTEGRATE
THEMSELVES BY PROMOTING
POTENTIALLY PROMOTING IN THE
CASE OF DISEASE, YOU KNOW
PROLIFERATION AND CLONAL
SELECTION OF CELLS THAT HAVE
DAMAGING MUTATIONS.
>> WHICH SORT OF RELATES TO THE
LESSER QUESTION, EARLY ON YOU
MENTIONED SOMETHING VERY, VERY
BRIEFLY ABOUT TREADMILL ACTIVITY
AND I WAS WONDERING HOW DOES
THAT RELATE TO A MUTATION IN THE
BRAIN IN.
>> SO AS FAR AS WE KNOW IT
DOESN'T CREATE MUTATIONS IN THE
BRAIN BUT IT CREATES A ROUND OF
PROLIFERATION IN THE DENTEGYRUS.
AND THEY'VE SHOWN THAT WITH
ANIMALS, SO IF THEY TAKE THEM TO
THE TREADMILL THEY GET A WAVE IN
THE HIPPOCAMPUS AND IT HELPS
THEM LEARN.
THAT'S GENERALLY THOUGHT OF AS A
POSITIVE THING, I DON'T KNOW I
DON'T KNOW THIS IS SOPHISTICATED
I HAVEN'T TOTALLY FIGURED OUT
HOW THE POSITIVE ASPECTS OF
HYPOCAMPAL NEUROGENESIS MIGHT
INTEGRATE WITH THE POTENTIAL FOR
IT TO INDUCE CLONAL SELECTION OF
DAMAGING VARIANTS EMPLOY N1 MORE
QUESTION AT LOWS, THE I WANT TO
REPEAT THE CME CODE THAT PEOPLE
CAN'T QUITE SEE.
510113 EMPLOY SO COULD THE
TRANSCRIPTION GENES BE A RESULT
OF TRANSCRIPTION COMPLEX
CREATING THE MUTATIONS?
>> YES, IT'S POSSIBLE THAT IF I
UNDERSTAND CORRECT 3 THAT
COMPLEX MIGHT INDUCE THE
MUTATION, THE WAY WE THINK ABOUT
IT IS SOMETHING THAT THE PROCESS
OF TRANSSCRIKS AND IT NEED TO BE
ABLE AND EXPOSING THE AND THEY
HAVE TO OPEN UP TO BE HELPFUL
EMPLOY NTHANK
>> BIG THANK YOU.
>> THANK YOU VERY MUCH.
>> [ APPLAUSE ]