TY - JOUR
T1 - Microglial TYROBP/DAP12 in Alzheimer’s disease
T2 - Transduction of physiological and pathological signals across TREM2
AU - Haure-Mirande, Jean Vianney
AU - Audrain, Mickael
AU - Ehrlich, Michelle E.
AU - Gandy, Sam
N1 - Funding Information:
The authors recognize the support of the National Institute on Aging Accelerating Medicines Partnership in Alzheimer’s Disease (AMP-AD awards U01AG046170 and R01AG057907 to MEE and SG), the National Institute on Aging (R03AG070710 to JVHM), the Cure Alzheimer’s Fund (SG, MEE), the Alzheimer’s Disease Research Division of BrightFocus Foundation (A2018253F to MA and A2016482F to JVHM), and the NIA-Designated Mount Sinai Alzheimer’s Disease Research Center (ADRC, Grant P30AG066514 to Mary Sano with internal pilot grant to MA).
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - TYROBP (also known as DAP12 or KARAP) is a transmembrane adaptor protein initially described as a receptor-activating subunit component of natural killer (NK) cells. TYROBP is expressed in numerous cell types, including peripheral blood monocytes, macrophages, dendritic cells, and osteoclasts, but a key point of recent interest is related to the critical role played by TYROBP in the function of many receptors expressed on the plasma membrane of microglia. TYROBP is the downstream adaptor and putative signaling partner for several receptors implicated in Alzheimer’s disease (AD), including SIRP1β, CD33, CR3, and TREM2. TYROBP has received much of its current notoriety because of its importance in brain homeostasis by signal transduction across those receptors. In this review, we provide an overview of evidence indicating that the biology of TYROBP extends beyond its interaction with these four ligand-binding ectodomain-intramembranous domain molecules. In addition to reviewing the structure and localization of TYROBP, we discuss our recent progress using mouse models of either cerebral amyloidosis or tauopathy that were engineered to be TYROBP-deficient or TYROBP-overexpressing. Remarkably, constitutively TYROBP-deficient mice provided a model of genetic resilience to either of the defining proteinopathies of AD. Learning behavior and synaptic electrophysiological function were preserved at normal physiological levels even in the face of robust cerebral amyloidosis (in APP/PSEN1;Tyrobp−/− mice) or tauopathy (in MAPTP301S;Tyrobp−/− mice). A fundamental underpinning of the functional synaptic dysfunction associated with each proteotype was an accumulation of complement C1q. TYROBP deficiency prevented C1q accumulation associated with either proteinopathy. Based on these data, we speculate that TYROBP plays a key role in the microglial sensome and the emergence of the disease-associated microglia (DAM) phenotype. TYROBP may also play a key role in the loss of markers of synaptic integrity (e.g., synaptophysin-like immunoreactivity) that has long been held to be the feature of human AD molecular neuropathology that most closely correlates with concurrent clinical cognitive function.
AB - TYROBP (also known as DAP12 or KARAP) is a transmembrane adaptor protein initially described as a receptor-activating subunit component of natural killer (NK) cells. TYROBP is expressed in numerous cell types, including peripheral blood monocytes, macrophages, dendritic cells, and osteoclasts, but a key point of recent interest is related to the critical role played by TYROBP in the function of many receptors expressed on the plasma membrane of microglia. TYROBP is the downstream adaptor and putative signaling partner for several receptors implicated in Alzheimer’s disease (AD), including SIRP1β, CD33, CR3, and TREM2. TYROBP has received much of its current notoriety because of its importance in brain homeostasis by signal transduction across those receptors. In this review, we provide an overview of evidence indicating that the biology of TYROBP extends beyond its interaction with these four ligand-binding ectodomain-intramembranous domain molecules. In addition to reviewing the structure and localization of TYROBP, we discuss our recent progress using mouse models of either cerebral amyloidosis or tauopathy that were engineered to be TYROBP-deficient or TYROBP-overexpressing. Remarkably, constitutively TYROBP-deficient mice provided a model of genetic resilience to either of the defining proteinopathies of AD. Learning behavior and synaptic electrophysiological function were preserved at normal physiological levels even in the face of robust cerebral amyloidosis (in APP/PSEN1;Tyrobp−/− mice) or tauopathy (in MAPTP301S;Tyrobp−/− mice). A fundamental underpinning of the functional synaptic dysfunction associated with each proteotype was an accumulation of complement C1q. TYROBP deficiency prevented C1q accumulation associated with either proteinopathy. Based on these data, we speculate that TYROBP plays a key role in the microglial sensome and the emergence of the disease-associated microglia (DAM) phenotype. TYROBP may also play a key role in the loss of markers of synaptic integrity (e.g., synaptophysin-like immunoreactivity) that has long been held to be the feature of human AD molecular neuropathology that most closely correlates with concurrent clinical cognitive function.
KW - Alzheimer
KW - Amyloid
KW - ApoE
KW - Complement C1q
KW - Disease-Associated Microglia (DAM)
KW - Sensome
KW - Tau
KW - Trem2
KW - Tyrobp/Dap12
KW - miR-155
UR - http://www.scopus.com/inward/record.url?scp=85136470664&partnerID=8YFLogxK
U2 - 10.1186/s13024-022-00552-w
DO - 10.1186/s13024-022-00552-w
M3 - Review article
C2 - 36002854
AN - SCOPUS:85136470664
VL - 17
JO - Molecular Neurodegeneration
JF - Molecular Neurodegeneration
SN - 1750-1326
IS - 1
M1 - 55
ER -