Aging Diagnostic Probe for Research on Aging and Evaluation of Anti-aging Drug Efficacy

Most mental health problems associated with psychological distress originate with activation of centrally regulated stress pathways, yet a diverse range of central nervous system and somatic disease states can be influenced by exposure to severe or unrelenting stress. The goal of this chapter is to provide a conceptual framework to guide the development of pharmacological intervention strategies. We propose that careful consideration of the relationship between the timing of stressful life experiences, pharmacological intervention, and the ultimate expression of disease symptomatology is critical for the development of pharmacological interventions to treat stress-related disorders. We review a range of physiological systems that are known to be activated by stress, offering potentially new targets for drug development efforts, and argue that participant selection is a key predictor of drug efficacy trials. In doing so, we point toward inflammatory signaling pathways as a potential final common mediator of multiple stress-related disease states.

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High resolution structural and functional MRI of the hippocampus in young adults with Down syndrome

Brain Communications ◽

10.1093/braincomms/fcab088 ◽

2021 ◽

Author(s):

Katherine A Koenig ◽

Se-Hong Oh ◽

Melissa R Stasko ◽

Elizabeth C Roth ◽

H Gerry Taylor ◽

...

Keyword(s):

Down Syndrome ◽

Functional Connectivity ◽

Cortical Thickness ◽

Right Hemisphere ◽

Gray Matter Volume ◽

Drug Efficacy ◽

Structure And Function ◽

7 Tesla ◽

Whole Brain ◽

And Function

Abstract Down syndrome is the phenotypic consequence of trisomy 21, with clinical presentation including both neurodevelopmental and neurodegenerative components. Although the intellectual disability typically displayed by individuals with Down syndrome is generally global, it also involves disproportionate deficits in hippocampally-mediated cognitive processes. Hippocampal dysfunction may also relate to Alzheimer’s disease-type pathology, which can appear in as early as the first decade of life and becomes universal by age 40. Using 7-tesla MRI of the brain, we present an assessment of the structure and function of the hippocampus in 34 individuals with Down syndrome (mean age 24.5 years ± 6.5) and 27 age- and sex-matched typically developing healthy controls. In addition to increased whole-brain mean cortical thickness and lateral ventricle volumes (p < 1.0 × 10−4), individuals with Down syndrome showed selective volume reductions in bilateral hippocampal subfields CA1, dentate gyrus, and tail (p < 0.005). In the group with Down syndrome, bilateral hippocampi showed widespread reductions in the strength of functional connectivity, predominately to frontal regions (p < 0.02). Age was not related to hippocampal volumes or functional connectivity measures in either group, but both groups showed similar relationships of age to whole-brain volume measures (p < 0.05). Finally, we performed an exploratory analysis of a subgroup of individuals with Down syndrome with both imaging and neuropsychological assessments. This analysis indicated that measures of spatial memory were related to mean cortical thickness, total gray matter volume, and right hemisphere hippocampal subfield volumes (p < 0.02). This work provides a first demonstration of the usefulness of high-field MRI to detect subtle differences in structure and function of the hippocampus in individuals with Down syndrome, and suggests the potential for development of MRI-derived measures as surrogate markers of drug efficacy in pharmacological studies designed to investigate enhancement of cognitive function.

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Site-Specific Dual-Labeling of a VHH with a Chelator and a Photosensitizer for Nuclear Imaging and Targeted Photodynamic Therapy of EGFR-Positive Tumors

Cancers ◽

10.3390/cancers13030428 ◽

2021 ◽

Vol 13 (3) ◽

pp. 428

Author(s):

Emma Renard ◽

Estel Collado Camps ◽

Coline Canovas ◽

Annemarie Kip ◽

Martin Gotthardt ◽

...

Keyword(s):

Photodynamic Therapy ◽

Fluorescence Imaging ◽

Ex Vivo ◽

Growth Factor Receptor ◽

Nuclear Imaging ◽

A431 Cells ◽

Site Specific ◽

Variable Domains ◽

Diagnostic Probe

Variable domains of heavy chain only antibodies (VHHs) are valuable agents for application in tumor theranostics upon conjugation to both a diagnostic probe and a therapeutic compound. Here, we optimized site-specific conjugation of the chelator DTPA and the photosensitizer IRDye700DX to anti-epidermal growth factor receptor (EGFR) VHH 7D12, for applications in nuclear imaging and photodynamic therapy. 7D12 was site-specifically equipped with bimodal probe DTPA-tetrazine-IRDye700DX using the dichlorotetrazine conjugation platform. Binding, internalization and light-induced toxicity of DTPA-IRDye700DX-7D12 were determined using EGFR-overexpressing A431 cells. Finally, ex vivo biodistribution of DTPA-IRDye700DX-7D12 in A431 tumor-bearing mice was performed, and tumor homing was visualized with SPECT and fluorescence imaging. DTPA-IRDye700DX-7D12 was retrieved with a protein recovery of 43%, and a degree of labeling of 0.56. Spectral properties of the IRDye700DX were retained upon conjugation. 111In-labeled DTPA-IRDye700DX-7D12 bound specifically to A431 cells, and they were effectively killed upon illumination. DTPA-IRDye700DX-7D12 homed to A431 xenografts in vivo, and this could be visualized with both SPECT and fluorescence imaging. In conclusion, the dichlorotetrazine platform offers a feasible method for site-specific dual-labeling of VHH 7D12, retaining binding affinity and therapeutic efficacy. The flexibility of the described approach makes it easy to vary the nature of the probes for other combinations of diagnostic and therapeutic compounds.

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Drosophila RASopathy Models Identify Disease Subtype Differences and Biomarkers of Drug Efficacy

iScience ◽

10.1016/j.isci.2021.102306 ◽

2021 ◽

pp. 102306

Author(s):

Tirtha K. Das ◽

Jared Gatto ◽

Rupa Mirmira ◽

Ethan Hourizadeh ◽

Dalia Kaufman ◽

...

Keyword(s):

Drug Efficacy ◽

Disease Subtype ◽

Subtype Differences

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Rapid visualized assessment of drug efficacy in live mice with a selectable marker-free autoluminescent Klebsiella pneumoniae

Biosensors and Bioelectronics ◽

10.1016/j.bios.2020.112919 ◽

2021 ◽

Vol 177 ◽

pp. 112919

Author(s):

Xirong Tian ◽

Yamin Gao ◽

Shuai Wang ◽

H.M. Adnan Hameed ◽

Wei Yu ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Selectable Marker ◽

Drug Efficacy ◽

Marker Free

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Common Treatment, Common Variant: Evolutionary Prediction of Functional Pharmacogenomic Variants

Journal of Personalized Medicine ◽

10.3390/jpm11020131 ◽

2021 ◽

Vol 11 (2) ◽

pp. 131

Author(s):

Laura B. Scheinfeldt ◽

Andrew Brangan ◽

Dara M. Kusic ◽

Sudhir Kumar ◽

Neda Gharani

Keyword(s):

In Silico ◽

Drug Efficacy ◽

Common Variant ◽

Genomic Research ◽

Whole Genome Sequencing Data ◽

Mendelian Disease ◽

Allele Frequency Distribution ◽

Sequencing Data ◽

Patient Race ◽

The Impact

Pharmacogenomics holds the promise of personalized drug efficacy optimization and drug toxicity minimization. Much of the research conducted to date, however, suffers from an ascertainment bias towards European participants. Here, we leverage publicly available, whole genome sequencing data collected from global populations, evolutionary characteristics, and annotated protein features to construct a new in silico machine learning pharmacogenetic identification method called XGB-PGX. When applied to pharmacogenetic data, XGB-PGX outperformed all existing prediction methods and identified over 2000 new pharmacogenetic variants. While there are modest pharmacogenetic allele frequency distribution differences across global population samples, the most striking distinction is between the relatively rare putatively neutral pharmacogene variants and the relatively common established and newly predicted functional pharamacogenetic variants. Our findings therefore support a focus on individual patient pharmacogenetic testing rather than on clinical presumptions about patient race, ethnicity, or ancestral geographic residence. We further encourage more attention be given to the impact of common variation on drug response and propose a new ‘common treatment, common variant’ perspective for pharmacogenetic prediction that is distinct from the types of variation that underlie complex and Mendelian disease. XGB-PGX has identified many new pharmacovariants that are present across all global communities; however, communities that have been underrepresented in genomic research are likely to benefit the most from XGB-PGX’s in silico predictions.

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