Selected Grantee Publications
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- 26 results found
- Neurological
- Imaging
Selective G Protein Signaling Driven by Substance P–Neurokinin Receptor Dynamics
Harris et al., Nature Chemical Biology. 2021.
https://www.nature.com/articles/s41589-021-00890-8
Investigators determined the cryogenic-electron microscopy structures of active neurokinin-1 receptor (NK1R) bound to neuropeptide substance P (SP) or the G protein q (Gq)-biased peptide SP6–11. Peptide interactions deep within NK1R are critical for receptor activation. Conversely, interactions between SP and NK1R extracellular loops are required for potent Gs-signaling but not Gq-signaling. Molecular dynamics simulations showed that these superficial contacts restrict SP flexibility. SP6–11, which lacks these interactions, is dynamic while bound to NK1R. Structural dynamics of NK1R agonists therefore depend on interactions with the receptor extracellular loops and regulate G protein signaling selectivity. This data unveils the molecular mechanism of how two stimuli (SP and Neurokinin A) yield distinct G protein signaling at the same G protein-coupled receptor. Supported by ORIP (S10OD021741, S10OD020054) and others.
Innate Immunity Stimulation via CpG Oligodeoxynucleotides Ameliorates Alzheimer’s Disease Pathology in Aged Squirrel Monkeys
Patel et al., Brain: A Journal of Neurology. 2021.
https://pubmed.ncbi.nlm.nih.gov/34128045/
Alzheimer's disease is the only illness among the top 10 causes of death for which there is no disease-modifying therapy. The authors have shown in transgenic Alzheimer's disease mouse models that harnessing innate immunity via TLR9 agonist CpG oligodeoxynucleotides (ODNs) modulates age-related defects associated with immune cells and safely reduces amyloid plaques, oligomeric amyloid-β, tau pathology, and cerebral amyloid angiopathy (CAA). They used a nonhuman primate model for sporadic Alzheimer's disease pathology that develops extensive CAA-elderly squirrel monkeys. They demonstrate that long-term use of Class B CpG ODN 2006 induces a favorable degree of innate immunity stimulation. CpG ODN 2006 has been well established in numerous human trials for a variety of diseases. This evidence together with their earlier research validates the beneficial therapeutic outcomes and safety of this innovative immunomodulatory approach. Supported by ORIP (P40OD010938), NINDS, NIA, and NCI.
Combining In Vivo Corneal Confocal Microscopy With Deep Learning-Based Analysis Reveals Sensory Nerve Fiber Loss in Acute Simian Immunodeficiency Virus Infection
McCarron et al., Cornea. 2021.
https://doi.org/10.1097/ICO.0000000000002661
Researchers characterized corneal subbasal nerve plexus features of normal and simian immunodeficiency virus (SIV)-infected pigtail and rhesus macaques using in vivo confocal microscopy and a deep learning approach for automated assessments. Corneal nerve fiber length and fractal dimension measurements did not differ between species, but pigtail macaques had significantly higher baseline corneal nerve fiber tortuosity than rhesus macaques. Acute SIV infection induced decreased corneal nerve fiber length and fractal dimension in the pigtail macaque model for HIV. Adapting deep learning analyses to clinical corneal nerve assessments will improve monitoring of small sensory nerve fiber damage in numerous clinical contexts, including HIV. Supported by ORIP (U42OD013117) and NINDS.
MRI Characteristics of Japanese Macaque Encephalomyelitis (JME): Comparison to Human Diseases
Tagge et al., Journal of Neuroimaging. 2021.
https://onlinelibrary.wiley.com/doi/10.1111/jon.12868
Magnetic resonance imaging data (MRI) were obtained from 114 Japanese macaques, including 30 animals of both sexes that presented with neurological signs of Japanese macaque encephalomyelitis (JME). Quantitative estimates of blood-brain barrier permeability to gadolinium-based-contrast agent (GBCA) were obtained in acute, GBCA-enhancing lesions, and longitudinal imaging data were acquired for 15 JME animals. Intense, focal neuroinflammation was a key MRI finding in JME. Several features of JME compare directly to human inflammatory demyelinating diseases. The development and validation of noninvasive imaging biomarkers in JME provides the potential to improve diagnostic specificity and contribute to the understanding of human demyelinating diseases. Supported by ORIP (P51OD011092, S10OD018224), NINDS, and NIBIB.
The High Affinity Dopamine D2 Receptor Agonist MCL-536: A New Tool for Studying Dopaminergic Contribution to Neurological Disorders
Subburaju et al., ACS Chemical Neuroscience. 2021.
https://pubs.acs.org/doi/full/10.1021/acschemneuro.1c00094
The dopamine D2 receptor exists in two different states, D2high and D2low; the former is the functional form of the D2 receptor and associates with intracellular G-proteins. The D2 agonist [3H]MCL-536 has high affinity for the D2 receptor (Kd 0.8 nM) and potently displaces the binding of (R-(-)-N-n-propylnorapomorphine (NPA; Ki 0.16 nM) and raclopride (Ki 0.9 nM) in competition binding assays. The authors characterized [3H]MCL-536. [3H]MCL-536 as metabolically stable. In vitro autoradiography on transaxial and coronal brain sections showed specific binding of [3H]MCL-536. [3H]MCL-536's unique properties make it a valuable tool for research on neurological disorders like Parkinson's disease or schizophrenia. Supported by ORIP (R43OD020186, R44OD024615) and NIMH.
Autologous Transplant Therapy Alleviates Motor and Depressive Behaviors in Parkinsonian Monkeys
Tao et al., Nature Medicine. 2021.
https://www.nature.com/articles/s41591-021-01257-1
Generation of induced pluripotent stem cells (iPSCs) enables standardized of dopamine (DA) neurons for autologous transplantation therapy to improve motor functions in Parkinson disease (PD). Adult male rhesus PD monkeys receiving autologous, but not allogenic, transplantation exhibited recovery from motor and depressive signs of PD over a 2-year period without immunosuppressive therapy. Mathematical modeling showed correlations between surviving DA neurons with PET signal intensity and behavior recovery regardless of autologous or allogeneic transplant, suggesting a predictive power of PET and motor behaviors for surviving DA neuron number. The results demonstrate favorable efficacy of the autologous transplant approach to treat PD. Supported by ORIP (P51OD011106) NINDS, and NICHD.