特別講演4
The Molecular Basis of Hypogonadism: From Mouse to
Human Models.
Sally Radovick
DepartmentofPediatrics,Rutgers-RobertWoodJohnsonMedicalSchool
The.precise.coordinated.expression.and.release.of.Gonadotropin-releasing.hormone.(GnRH).from.the.hypothalamus.
is. critical. for. establishing. and. maintaining. reproduction.. Elucidating. the. molecular. mechanisms. of. GnRH. gene.
expression.and.regulation.is.thus.vitally.important.for.a.complete.understanding.of.mammalian.reproduction..The.goal.
of.our.studies.is.to.provide.in.vitro.and.in.vivo.characterization.of.the.signals.and.cell-specific.proteins.that.mediate.
hypothalamic.GnRH.gene.expression.during.puberty.and.reproduction..We.use.both.GnRH-neuronal.cell.lines.to.probe.
detailed.molecular.mechanisms.complemented.with.in.vivo.expression.studies.in.mice.to.permit.a.critical.physiological.
assessment.of.the.relevance.of.each.finding..
Kisspeptin,.a. protein. controlling.GnRH-mediated.pubertal. maturation.and. reproduction,.is. expressed. in. specific.
neurons.located.in.the.arcuate.(ARC).and.anteroventral.periventricular.(AVPV).nuclei.of.the.hypothalamus.and.
controls.GnRH-mediated.pubertal.maturation.and.reproduction..We.have.shown.that.kisspeptin.binds.to.its.receptor,.
a.specific.G-protein.coupled.receptor.(GPR54.or.Kiss1R),.and.in.addition.to.stimulating.GnRH.release,.increases.GnRH.
mRNA.levels.in.GnRH.neuronal.cell.lines..Further,.we.have.localized.a.kisspeptin-response.element.(KsRE).within.the.
previously.identified.GnRH.enhancer.element..To.define.the.role.of.kisspeptin-Kiss1r.signaling.directly.at.the.level.of.the.
GnRH.neuron,.a.GnRH.neuron-specific.Kiss1r.knockout.(GKirKO).mouse.model.was.generated.using.a.Cre.recombinase.
and.LoxP.site.system..A.significant.delay.in.pubertal.onset.in.females.and.male.GKirKO.mice.was.observed..In.female.
GKirKO.mice,.irregular.estrous.cyclicity.was.observed.and.male.and.female.mutant.mice.had.reduced.gonadotropin.
levels.and.decreased.levels.of.sex.hormones...Moreover,.infertility.was.observed.in.both.female.and.male.GKirKO.mice..
ARC.
Kiss1
.neurons,.which.largely.co-express.the.neuropeptides.NKB.and.dynorphin.(collectively.known.as.KNDy.
neurons),.are.thought.to.be.the.primary.regulators.of.pulsatile.release.of.GnRH.and.LH.and.mediate.estrogen-induced.
negative.feedback.control.of.both.GnRH.and.LH..We.generated.a.Pdyn-Cre/Kiss1
fl/fl
.(KO).mouse.model.to.target.
Kiss1
.in.
the.ARC.to.differentiate.KNDy.neuron-specific.function.from.AVPV.
Kiss1
.function.in.the.maturation.and.maintenance.
of.the.reproductive.axis..Markers.of.pubertal.onset.were.normal.in.KO.mice;.however,.KO.female.mice.developed.
disrupted.estrous.cycles.presenting.with.persistent.diestrus,.exhibited.significantly.fewer.LH.pulses.and.were.infertile...
Male.mice.had.reduced.spermatogenesis.and.were.subfertile...
Taken.together,.these.data.provide.in.vivo.evidence.that.Arc.kisspeptin.and.the.Kiss1r.in.GnRH.neurons.is.critical.for.
proper.and.timely.reproductive.development.and.fertility..This.work.provides.new.insight.into.the.physiological.role.of.
kisspeptin.and.Kiss1r.in.mediating.GnRH.neuronal.function.and.mammalian.reproduction.
Sally Radovick, MD, received her medical degree from Northeastern Ohio Universities College of Medicine. She then completed her
residency in Pediatrics at Case Western Reserve University and her fellowship in Pediatric Endocrinology at the National Institutes of Health
(NIH). She is currently the Chair of Pediatrics and Senior Associate Dean for Clinical and Translational Research at Rutgers-Robert Wood
Johnson Medical School. Prior to this position, she was the Division Director of Pediatric Endocrinology and the Vice Chair for Research in the
Department of Pediatrics at Johns Hopkins University School of Medicine.
Dr. Radovick is a specialist in growth and development and pubertal disorders in children. Her research is focused on determining the
regulation of the gonadotropin-releasing hormone (GnRH) gene, which has a central role in controlling the onset of puberty. Her group was the
first to generate GnRH-expressing neuronal cell-lines and in vitro map the cellular regulation of this critical gene by growth factors which has
increased knowledge of the relationship between growth, puberty and nutrition. She has progressed to development of genetically modified
mouse models to elucidate mechanisms of in vivo regulation of GnRH secretion in response to neuroendocrine and growth factor stimulation
and sex steroid feedback regulation. Of particular interest has been to determine the roles of neurotransmitter/hormone receptors in mediating
the large increase in GnRH secretion to adult levels at puberty, which results in the attainment of fertility. These studies will provide insights
into pubertal disorders, PCOS, as well as provide future therapies for infertility. She has been continuously funded for this work by the NIH since
1992. The other major area of this research has been to characterize the transcription factors important for normal pituitary development. Her
initial studies provided the first genetic mechanism of a child with short stature due to hypopituitarism; this involved a mutation in the Pit-1
gene that is necessary for pituitary cell lineage determination and differentiation. She has gone on to describe the mechanisms by which novel
mutations in other pituitary-specific transcription factors responsible for pituitary hormone deficiencies in man. These studies are supported by
a U01 collaborative agreement with investigators at the NIH at the NIH Clinical Center.
Dr. Radovick has authored or co-authored more than 100 peer-reviewed scientific publications and has been invited to write a dozen book
chapters in her field. She is an author of “Puberty in the female and its disorders” in Sperling’s textbook, Pediatric Endocrinology and “Normal
and aberrant growth” in Williams Textbook of Endocrinology. She served as Associate Editor for Pediatric Endocrinology for the Journal of Clinical
Endocrinology and Metabolism.
Dr. Radovick served as the President of the Pediatric Endocrine Society, the Chair of the Research Council, a Council member and Chair of
the Drug and Therapeutics Committee. She was also a member of the Guidelines Committee and the Finance Committee of the Endocrine
Society, co-Chair of the hypothyroidism subcommittee and a member of the Program Committee. She is a co-author of the AACE Growth
Hormone Guidelines
Dr. Radovick has been NIH funded in conducting biomedical research and mentoring students and fellows for over 25 years. She has trained
over 70 predoctoral students and postdoctoral fellows and junior faculty and has remained clinically active during her career, precepting
teaching clinics in Pediatric Endocrinology. She is the curator of a tissue repository for patients with hypopituitarism and currently the PI of the
newly funded Rutgers CTSA KL2 program. Dr. Radovick's most notable teaching efforts have been in training individuals for scientific research.
特別講演5
New Thoughts on Hepatic Gluconeogenesis in Diabetes
Mellitus
Fredric E. Wondisford
DepartmentofMedicine,Rutgers-RobertWoodJohnsonMedicalSchool
Dysregulated.glucagon.secretion.in.diabetes.mellitus.activates.gluconeogenesis.(GNG),.and.glucagon.
is.thought.to.stimulate.GNG.primarily.by.increasing.the.use.of.glutamine.and.pyruvate/lactate.as.
substrates..In.contrast,.we.showed.that.glycerol.is.the.preferred.substrate.in.both.cultured.primary.
hepatocytes.(PH).and.in.vivo..In.this.study,.PH.were.treated.with.13C.labeled.substrate.mixtures.at.
physiological.fasting.concentrations.to.quantify.relative.usage..While.glucagon.increased.GNG.from.
all.substrates.by.inducing.G6pc,.~.80%.of.gluconeogenic.carbon.originated.from.glycerol.
By.increasing.Pck1,.glucagon.also.modestly.shifted.GNG.usage.toward.non-glycerol.sources..
Unexpectedly,.glycerol.modified.glucagon’s.effect.on.both.G6pc.and.Pck1,.resulting.in.a.synergistic.
increase.in.GNG.and.a.shift.toward.glycerol.usage..In.vivo.studies.using.high-fat.diet.(HFD).
and.PKA-activated.mice.confirm.these.findings,.and.blocking.glycerol.metabolism.reverses.the.
phenotype.caused.by.HFD,.demonstrating.a.central.role.for.glycerol.in.regulating.GNG.
Fredric E. Wondisford is the Henry Rutgers Professor and Chair of Medicine, Rutgers-RWJMS. In this position
he oversees a Department with 148 full-time and 440 affiliate faculty members. Prior to this appointment, he
was Professor of Medicine, Pediatrics and Physiology and Director of the Metabolism Division and Diabetes
Institute at Johns Hopkins University School of Medicine. Dr. Wondisford runs a large laboratory that has
been funded by the NIH since 1990. He has published over 200 original articles, reviews and books. He has or
is currently scientifically mentoring 74 trainees, of whom 39 have gone on to independent academic research
careers - 4 chairs of medicine (professors), 2 chiefs of endocrinology (associate professors), 7 professors, 11
associate professors, 9 assistant professors, and 6 instructors. During his mentoring activities, Dr. Wondisford
was supported by a K24, was the PI or Co-PI on two T32 grants and supervised training programs in two different
NIH P60 diabetes centers as the P.I. (University of Chicago and Johns Hopkins Diabetes Research and Training
Centers). Dr. Wondisford’s laboratory has two main research interests: 1) Regulation of gene expression by
nuclear thyroid hormone receptors and 2) Control of hepatic glucose production in health and disease.
特別講演4
The Molecular Basis of Hypogonadism: From Mouse to
Human Models.
Sally Radovick
DepartmentofPediatrics,Rutgers-RobertWoodJohnsonMedicalSchool
The.precise.coordinated.expression.and.release.of.Gonadotropin-releasing.hormone.(GnRH).from.the.hypothalamus.
is. critical. for. establishing. and. maintaining. reproduction.. Elucidating. the. molecular. mechanisms. of. GnRH. gene.
expression.and.regulation.is.thus.vitally.important.for.a.complete.understanding.of.mammalian.reproduction..The.goal.
of.our.studies.is.to.provide.in.vitro.and.in.vivo.characterization.of.the.signals.and.cell-specific.proteins.that.mediate.
hypothalamic.GnRH.gene.expression.during.puberty.and.reproduction..We.use.both.GnRH-neuronal.cell.lines.to.probe.
detailed.molecular.mechanisms.complemented.with.in.vivo.expression.studies.in.mice.to.permit.a.critical.physiological.
assessment.of.the.relevance.of.each.finding..
Kisspeptin,.a. protein. controlling.GnRH-mediated.pubertal. maturation.and. reproduction,.is. expressed. in. specific.
neurons.located.in.the.arcuate.(ARC).and.anteroventral.periventricular.(AVPV).nuclei.of.the.hypothalamus.and.
controls.GnRH-mediated.pubertal.maturation.and.reproduction..We.have.shown.that.kisspeptin.binds.to.its.receptor,.
a.specific.G-protein.coupled.receptor.(GPR54.or.Kiss1R),.and.in.addition.to.stimulating.GnRH.release,.increases.GnRH.
mRNA.levels.in.GnRH.neuronal.cell.lines..Further,.we.have.localized.a.kisspeptin-response.element.(KsRE).within.the.
previously.identified.GnRH.enhancer.element..To.define.the.role.of.kisspeptin-Kiss1r.signaling.directly.at.the.level.of.the.
GnRH.neuron,.a.GnRH.neuron-specific.Kiss1r.knockout.(GKirKO).mouse.model.was.generated.using.a.Cre.recombinase.
and.LoxP.site.system..A.significant.delay.in.pubertal.onset.in.females.and.male.GKirKO.mice.was.observed..In.female.
GKirKO.mice,.irregular.estrous.cyclicity.was.observed.and.male.and.female.mutant.mice.had.reduced.gonadotropin.
levels.and.decreased.levels.of.sex.hormones...Moreover,.infertility.was.observed.in.both.female.and.male.GKirKO.mice..
ARC.
Kiss1
.neurons,.which.largely.co-express.the.neuropeptides.NKB.and.dynorphin.(collectively.known.as.KNDy.
neurons),.are.thought.to.be.the.primary.regulators.of.pulsatile.release.of.GnRH.and.LH.and.mediate.estrogen-induced.
negative.feedback.control.of.both.GnRH.and.LH..We.generated.a.Pdyn-Cre/Kiss1
fl/fl
.(KO).mouse.model.to.target.
Kiss1
.in.
the.ARC.to.differentiate.KNDy.neuron-specific.function.from.AVPV.
Kiss1
.function.in.the.maturation.and.maintenance.
of.the.reproductive.axis..Markers.of.pubertal.onset.were.normal.in.KO.mice;.however,.KO.female.mice.developed.
disrupted.estrous.cycles.presenting.with.persistent.diestrus,.exhibited.significantly.fewer.LH.pulses.and.were.infertile...
Male.mice.had.reduced.spermatogenesis.and.were.subfertile...
Taken.together,.these.data.provide.in.vivo.evidence.that.Arc.kisspeptin.and.the.Kiss1r.in.GnRH.neurons.is.critical.for.
proper.and.timely.reproductive.development.and.fertility..This.work.provides.new.insight.into.the.physiological.role.of.
kisspeptin.and.Kiss1r.in.mediating.GnRH.neuronal.function.and.mammalian.reproduction.
Sally Radovick, MD, received her medical degree from Northeastern Ohio Universities College of Medicine. She then completed her
residency in Pediatrics at Case Western Reserve University and her fellowship in Pediatric Endocrinology at the National Institutes of Health
(NIH). She is currently the Chair of Pediatrics and Senior Associate Dean for Clinical and Translational Research at Rutgers-Robert Wood
Johnson Medical School. Prior to this position, she was the Division Director of Pediatric Endocrinology and the Vice Chair for Research in the
Department of Pediatrics at Johns Hopkins University School of Medicine.
Dr. Radovick is a specialist in growth and development and pubertal disorders in children. Her research is focused on determining the
regulation of the gonadotropin-releasing hormone (GnRH) gene, which has a central role in controlling the onset of puberty. Her group was the
first to generate GnRH-expressing neuronal cell-lines and in vitro map the cellular regulation of this critical gene by growth factors which has
increased knowledge of the relationship between growth, puberty and nutrition. She has progressed to development of genetically modified
mouse models to elucidate mechanisms of in vivo regulation of GnRH secretion in response to neuroendocrine and growth factor stimulation
and sex steroid feedback regulation. Of particular interest has been to determine the roles of neurotransmitter/hormone receptors in mediating
the large increase in GnRH secretion to adult levels at puberty, which results in the attainment of fertility. These studies will provide insights
into pubertal disorders, PCOS, as well as provide future therapies for infertility. She has been continuously funded for this work by the NIH since
1992. The other major area of this research has been to characterize the transcription factors important for normal pituitary development. Her
initial studies provided the first genetic mechanism of a child with short stature due to hypopituitarism; this involved a mutation in the Pit-1
gene that is necessary for pituitary cell lineage determination and differentiation. She has gone on to describe the mechanisms by which novel
mutations in other pituitary-specific transcription factors responsible for pituitary hormone deficiencies in man. These studies are supported by
a U01 collaborative agreement with investigators at the NIH at the NIH Clinical Center.
Dr. Radovick has authored or co-authored more than 100 peer-reviewed scientific publications and has been invited to write a dozen book
chapters in her field. She is an author of “Puberty in the female and its disorders” in Sperling’s textbook, Pediatric Endocrinology and “Normal
and aberrant growth” in Williams Textbook of Endocrinology. She served as Associate Editor for Pediatric Endocrinology for the Journal of Clinical
Endocrinology and Metabolism.
Dr. Radovick served as the President of the Pediatric Endocrine Society, the Chair of the Research Council, a Council member and Chair of
the Drug and Therapeutics Committee. She was also a member of the Guidelines Committee and the Finance Committee of the Endocrine
Society, co-Chair of the hypothyroidism subcommittee and a member of the Program Committee. She is a co-author of the AACE Growth
Hormone Guidelines
Dr. Radovick has been NIH funded in conducting biomedical research and mentoring students and fellows for over 25 years. She has trained
over 70 predoctoral students and postdoctoral fellows and junior faculty and has remained clinically active during her career, precepting
teaching clinics in Pediatric Endocrinology. She is the curator of a tissue repository for patients with hypopituitarism and currently the PI of the
newly funded Rutgers CTSA KL2 program. Dr. Radovick's most notable teaching efforts have been in training individuals for scientific research.