Heterochronic parabiosis: the promise of pro- and anti-geronic factors
Joseph M. Castellano, Ph.D. Stanford University School of Medicine, Wyss-Coray Laboratory
2016 OAIC Annual Meeting, April 19, 2016
Aging is a major risk factor for disease
Young (31 y) Old (88 y)
• Normal brain aging alterations: – Cognitive – Cellular – Molecular
• Aging is major risk factor for many neurological disorders
• Aged population projected to double by 2030
Young
Systemic environment
Old
Positive factors Positive factors
Conboy et al., 2005 Sinha et al., 2014
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Conboy et al., 2005
Conboy et al., 2005 Sinha et al., 2014
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Salpeter et al., 2013
Conboy et al., 2005
Conboy et al., 2005 Sinha et al., 2014
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Loffredo et al., 2013
Salpeter et al., 2013
Conboy et al., 2005
Conboy et al., 2005 Sinha et al., 2014
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Loffredo et al., 2013
Salpeter et al., 2013
Conboy et al., 2005
Conboy et al., 2005 Sinha et al., 2014
Baht et al., 2015
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Loffredo et al., 2013
Salpeter et al., 2013
Conboy et al., 2005
Conboy et al., 2005 Sinha et al., 2014
Villeda et al., 2011 Villeda et al., 2014 Katsimpardi et al., 2014
Baht et al., 2015
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Loffredo et al., 2013
Salpeter et al., 2013
Conboy et al., 2005
Conboy et al., 2005 Sinha et al., 2014
Villeda et al., 2011 Villeda et al., 2014 Katsimpardi et al., 2014
Baht et al., 2015
?
Young blood regulates aging processes in diverse tissues
Castellano et al., JAMA Neurol, 2015 (for review)
Adult neurogenesis occurs in lateral ventricles and the hippocampus (DG)
Signals in the systemic environment regulate neurogenesis in dentate gyrus
Villeda et al., 2011
Pro-aging factor CCL11 increases with age and impairs learning/memory
Villeda et al., 2011
Pro-aging factor CCL11 increases with age and impairs learning/memory
Villeda et al., 2011 B2M also revealed to be anti-neurogenic, pro-aging factor Smith et al., 2015, Nat Med
Blood-borne factors that promote plasticity and/or
cognition
e.g., GDF11, many others
Exposure to young blood revitalizes the aged brain
Plasticity gene networks
Dendritic spines/LTP
Microgliosis
Rejuvenation
Neurogenesis
Villeda et al., Nat Med, 2014 and unpublished
Learning/memory
Young blood
plasma
Strategy for the identification of rejuvenating factors
Cellular/molecular changes
Cognitive assessment
Mouse Aging
Heterochronic Parabiosis
Human Donors
Strategy for the identification of rejuvenating factors
Mouse Aging
Heterochronic Parabiosis
Human Donors
Umbilical cord
~ 20 years
~ 65 years
Cognitive assessment
Cellular/molecular changes
Cytokines Chemokines
Growth factors Neurotrophins
Hormone-like proteins Acute-phase proteins Complement factors Secreted receptors Sample array w/ differential
plasma protein signals
Plasma protein factors
150 µm spot
Protein microarray to assess relative plasma protein expression
Protein microarray reveals many elevated factors in cord plasma
Low High
Cord Young Old
Secreted Plasma Factors Castellano et al., in revision
Protein microarray reveals many elevated factors in cord plasma
Low High
Cord Young Old
Secreted Plasma Factors Castellano et al., in revision
Administration of human plasma in “NSG” mice
Heterochronic Parabiosis Changes
Mouse Human
Administration of human plasma in “NSG” mice
NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ aka “NOD Scid Gamma” (NSG)
Heterochronic Parabiosis Changes
Mouse Human
Age-dependent changes in immediate early gene marker c-Fos
Castellano et al., in revision
NSG mice exhibit other age-dependent hippocampal pathology
Castellano et al., in revision
NSG mice exhibit age-dependent learning and memory deficits
Castellano et al., in revision
NSG mice exhibit age-dependent learning and memory deficits
Castellano et al., in revision
Administration of human plasma in aged NSG mice
Aged NSG
Days 0 14
Human plasma donors
Behavior
Microarray/qPCR/IHC
Human plasma treatment results in distinct gene profiles in hippocampi
Castellano et al., in revision
Human plasma treatment results in distinct gene profiles in hippocampi
Castellano et al., in revision
Ontology-based activation prediction -Long-term memory -Long-term potentiation -neuritogenesis Plasticity upregulation by qPCR -c-Fos, Egr1, junb, camk2a, etc.
Aged NSG
Cord plasma increases c-Fos+ cell number in aged but not young dentate gyrus
Castellano et al., in revision
Aged NSG Young NSG
Cord plasma increases c-Fos+ cell number in aged but not young dentate gyrus
Castellano et al., in revision
Cord PLM activates DG granule neurons (excitatory)
Castellano et al., in revision
RE
SE
Treatment with cord plasma enhances LTP in dentate gyrus
Castellano et al., in revision
LTP is unaffected following young or elderly human plasma treatment
Castellano et al., in revision
Treatment with cord plasma improves learning and memory performance
Castellano et al., in revision
Strategy for the identification of rejuvenating factors
Cellular/molecular changes
Mouse Aging
Heterochronic Parabiosis
Human Aging Umbilical cord
plasma
Cognitive assessment
Strategy for the identification of rejuvenating factors
Cellular/molecular changes
Mouse Aging
Heterochronic Parabiosis
Human Aging
Cognitive assessment
In vivo “screen” of potential rejuvenating factors in aged WT mice
0 2 4 6 10
Putative Factors or vehicle i.p.
Days
Castellano et al., in revision
Plasma TIMP2 is reduced very early in life in blood and brain
Castellano et al., in revision
Human
Mouse
Systemic supplementation with TIMP2 enhances synaptic plasticity in aged mice
0 2 4 6 8 10 12 14
rTIMP2 or vehicle i.p.
Days
Castellano et al., in revision
Systemic treatment with TIMP2 improves learning and memory in aged WT mice
Castellano et al., in revision
Systemic TIMP2 is necessary for spatial memory
Training
Novel Location
Day 1
Day 2
Castellano et al., in revision
Translational potential of blood-borne proteins • TIMP2
– 21-24 kDa; non-glycosylated – Limits tumor angiogenesis and plays role in tissue
remodeling – Broad MMP inhibitor Marimastat proceeded to Phase
III trials (discontinued)
• Ongoing plasma trials related to CNS – AMBAR (Alzheimer’s Management by Albumin
Replacement - Grifols) – PLASMA (PLasma for Alzheimer’s SyMptom
Amelioration)
Conclusions
• Blood factors can regulate aging process in diverse tissues – Developmental-stage human plasma (UC) improves neuronal and
cognitive function – Young plasma proteins (TIMP2) restore or improve function of aged
hippocampus – Use of NSG mouse model allows for identification of relevant
blood-borne proteins with possible translational implications
Acknowledgements
Wyss-Coray Lab Tony Wyss-Coray Kira I. Mosher Rachelle Abbey Daniela Berdnik Jadon Shen
Xie Lab/AfaSci Simon Xie Bende Zou
Stanford Tom Rando Martin Angst
Funding Sources -NIH/NIA -Jane Coffin Childs Postdoctoral Fellowship/Simons Foundation -Stanford Child Health Research Institute Postdoctoral Fellowship -Donor’s Cure Foundation, CCAD
Youthful systemic factors
Stimulated vascular endothelium
Disrupted BBB?
Youth-associated leukocytes?
Transport? Diffusion? Secondary signals?
Synaptic plasticity
Neurogenesis Cell-to-cell Signaling?
Oligodendrocyte activity
Castellano et al., JAMA Neurol, 2015
Young blood alters brain via unknown mechanisms/factors
Human plasma does not alter the number of neuroblasts in dentate gyrus of NSG mice
Castellano et al., in revision
rTIMP2 treatment does not appear to alter DCX+ cell number in aged DG
Castellano et al., in revision
TIMP2 expression in plasma and hippocampus declines gradually with age in mice
Castellano et al., in revision
Blood-borne factor GDF11 mediates SVZ neurogenesis rejuvenation
Katsimpardi et al., 2014
