Biology subjects

Tanifum, E.

Publications and source records attributed to Tanifum, E..

4 recordsLinked to original sources

bioRxiv2026

Microglia-Specific Molecular Magnetic Resonance Imaging Probe Enables Noninvasive Separation of Parkinsonian Mice from Controls

AbstractNeuroinflammation mediated by reactive microgliosis is a central driver of Parkinsons disease (PD) pathogenesis. This inflammatory process unfolds years before clinical symptoms, creating an opportunity for early intervention. In vivo imaging technologies that could detect and quantify microglial reactivity are therefore essential for early diagnosis, patient stratification, and evaluating emerging immunomodulatory therapies that target this fundamental driver of PD progression. Yet no standardized, sensitive, and specific technology currently achieves this goal. Molecular magnetic resonance imaging (mMRI) is uniquely suitable to address this problem because it integrates inherent high spatial resolution and soft-tissue contrast of conventional MRI with molecularly targeted contrast agents, enabling simultaneous acquisition of anatomical detail and functional/biological information at submillimeter isotropic resolution. Here we present a novel mMRI probe designed to specifically target colony stimulating factor-1 receptor, expressed primarily on microglia in the brain. In silico data show that the targeting ligand binds the extracellular Ig domain of the receptor. In vitro cell uptake studies with both murine and human microglia cell lines show that the probe binds the receptor triggering active cell uptake and in vivo MRI enabled effective separation of the A53T mouse model of Parkinsons disease from control mice using radiomics-assisted MR image analysis. Ex-vivo immunohistochemical analysis showed signal from the probe largely in the cytosolic compartment of IBA-1 reactive cells, confirming that the observed in vivo MRI signal is due primarily to retention of the agent by microglia. This novel technology has the potential to interrogate the rgional presentation of microglial activation in PD. One Sentence SummaryA microglia targeted MRI probe generates disease-specific contrast after injection, clearly distinguishing A53T Parkinsonian mice from controls.

neuroscience↗

bioRxiv2024

Accelerated amyloid deposition in SARS-CoV-2 infected mouse models of Alzheimer's disease

Familial Alzheimers disease (AD) involving known AD causing genes accounts for a small fraction of cases, the vast majority are sporadic. Neuroinflammation, secondary to viral infection, has been suggested as an initiating or accelerating factor. In this work we tested the hypothesis that SARS-CoV-2 (SCV2) viral infection accelerates the development of AD pathology in mouse models of AD. We profiled transcriptomic changes using transgenic APP/PSEN1 and P301S mouse models that develop AD pathology and k18hACE2 mice that express the humanized ACE2 receptor used by SCV2 to enter cells. This study identified the interferon and chemokine responses constituting key shared pathways between SCV2 infection and the development of AD pathology. Two transgenic mouse models of AD: APP/PSEN1 (develops amyloid pathology) and 3xTg AD (develops both amyloid and tau pathology) were crossed with k18-hACE2 mice to generate hybrid hACE2-3xTg and hACE2-APP/PSEN1 mice. Neuroinflammation and amyloid deposition in the brain of infected mice were imaged in vivo using molecular MRI (mMRI) probes and confirmed postmortem by histopathology. Results show that 11-14-month-old SCV2 infected hACE2-3xTg mice exhibit neuroinflammation 10 days post infection and 4-5-month-old hACE2-APP/PS1 hybrid mice develop amyloid deposits, while age-matched uninfected mice exhibit neither phenotype. This suggests that SCV2 infection could induce or accelerate AD when risk factors are present.

neuroscience↗

bioRxiv2023

A dual target molecular MRI probe for noninvasive profiling of pathologic alpha-synuclein and microgliosis in a mouse model of Parkinson's disease

Parkinsons disease is characterized progressive deposition of pathologic alpha-synuclein (-syn) aggregates, neuroinflammation, and death of dopaminergic neurons in the substantia nigra projecting to the striatum. Noninvasive in vivo profiling of -syn aggregate accumulation and microgliosis by molecular imaging can provide insights on the underlying mechanisms of disease progression, facilitating the development of effective treatment. However, no classical imaging methods have been successful, despite several attempts. We demonstrate a novel method to noninvasive in vivo profiling of pathologic -syn in combination with microgliosis using molecular magnetic resonance imaging (MRI), by targeting oligomeric -syn in cerebrospinal fluid with nano scavengers (T) bearing a T1-relaxive Gd(III) payload. In this proof-of-concept report we demonstrate, in vitro, that microglia and neuroblastoma cell lines internalize cross-linked T/oligomeric -syn agglomerates. Delayed in vivo T1-weighted MRI scans following intravenous administration in the M83 -syn transgenic mouse line show statistically significant T1 signal enhancement in test mice versus controls. The in vivo data was validated by ex-vivo immunohistochemical analysis which showed a strong correlation between in vivo MRI signal enhancement, Lewy pathology distribution, and microglia activity in the treated brain tissue. Furthermore, neuronal, and microglial cells in brain tissue from treated mice displayed strong cytosolic signal originating from T, confirming in vivo cell uptake of the nano scavengers.

neuroscience↗

bioRxiv2021

Early Detection of Tau Pathology

While a definitive Alzheimers disease (AD) diagnosis remains a post-mortem exercise, the ATN Research Framework proposed by the National Institute on Aging and the Alzheimers Association utilizes a score representing the presence of amyloid deposits (A), tau deposits (T) and neuronal degeneration markers (N), with A+T+ necessary for a positive diagnosis. Current detection of tau pathology lags amyloid detection by years and by the time both markers are detected the disease is fairly advanced. We describe the development of a new generation of molecular imaging probes for in vivo detection of cells undergoing abnormal phosphorylation representing the initial stages of pTau pathology, potentially enabling a very early stage diagnosis of AD. We describe a novel nanoparticle formulation that binds such abnormally phosphorylating cells in a mouse model of tau pathology, enabling in vivo visualization of the hyperphosphorylative state by magnetic resonance imaging. Our results demonstrate the potential of this novel platform to identify a correlative marker signifying the development of future tau pathology, and has implications for early-stage diagnosis of Alzheimers disease.

neuroscience↗