Selected Grantee Publications
PIKFYVE Inhibition Mitigates Disease in Models of Diverse Forms of ALS
Hung et al., Cell . 2023.
https://doi.org/10.1016/j.cell.2023.01.005
Investigators showed that pharmacological suppression of PIKFYVE activity reduces pathology and extends survival of animal models and patient-derived motor neurons representing diverse forms of amyotrophic lateral sclerosis (ALS). Upon PIKFYVE inhibition, exocytosis is activated to transport aggregation-prone proteins out of the cells, a process that does not require stimulating macroautophagy or the ubiquitin-proteosome system. These findings suggest therapeutic potential to manage multiple forms of ALS. Supported by ORIP (S10OD021553) and NINDS.
CD8+ Lymphocytes Do Not Impact SIV Reservoir Establishment under ART
Statzu et al., Nature Microbiology. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9894752/
The HIV-1 latent reservoir has been shown to persist following antiretroviral therapy (ART), but the mechanisms underlying the establishment and maintenance of the reservoir are not fully understood. Using rhesus macaques of both sexes, investigators examined the effects of CD8+ T cells on formation of the latent reservoir with simian immunodeficiency virus (SIV) infection. They found that CD8+ T cell depletion resulted in slower decline of viremia but did not change the frequency of infected CD4+ T cells in the blood or lymph nodes. Additionally, the size of the persistent reservoir was unchanged. These findings suggest that the viral reservoir is established largely independent of SIV-specific cytotoxic T lymphocyte control. Supported by ORIP (P51OD011132), NIAID, NCI, NIDDK, NIDA, NHLBI, and NINDS.
TMEM161B Modulates Radial Glial Scaffolding in Neocortical Development
Wang et al., PNAS. 2023.
https://www.pnas.org/doi/10.1073/pnas.2209983120
Neocortical folding (i.e., gyrification) is a fundamental evolutionary mechanism allowing the expansion of cortical surface area and increased cognitive function. This study identifies TMEM161B in gyral spacing in humans, likely affecting radial glial cell polarity through effects on the actin cytoskeleton. Patients carrying TMEM161B mutations exhibit striking neocortical polymicrogyria and intellectual disability. TMEM161B knockout mice fail to develop midline hemispheric cleavage, whereas knock-in of patient mutations and patient-derived brain organoids show defects in apical cell polarity and radial glial scaffolding. The data implicating TMEM161B in murine holoprosencephaly may suggest shared mechanisms between the formation of the brain midline and cortical gyrification. Supported by ORIP (U54OD030187), NINDS, and NHGRI.
PGRN Deficiency Exacerbates, Whereas a Brain Penetrant PGRN Derivative Protects, GBA1 Mutation–Associated Pathologies and Diseases
Zhao et al., Proc Natl Acad Sci USA. 2023.
https://www.pnas.org/doi/10.1073/pnas.2210442120
Mutations in GBA1 are associated with Gaucher disease (GD) and are also genetic risks in developing Parkinson’s disease (PD). Investigators created a mouse model and demonstrated that progranulin (PGRN) deficiency in Gba1 mutant mice caused early onset and exacerbated GD phenotypes, leading to substantial increases in substrate accumulation and inflammation in visceral organs and the central nervous system. These in vivo and ex vivo data demonstrated that PGRN plays a crucial role in the initiation and progression. In addition, the mouse model provides a clinically relevant system for testing therapeutic approaches for GD and PD. Supported by ORIP (R21OD033660), NIAMS, and NINDS.
Duration of Antiretroviral Therapy Impacts the Degree of Residual SIV Infection in the Gut in Long‐Term Non‐Progressing Chinese Rhesus Macaques
Solis-Leal et al., Journal of Medical Virology. 2023.
https://onlinelibrary.wiley.com/doi/abs/10.1002/jmv.28185
HIV and simian immunodeficiency virus (SIV) reservoirs have been shown to persist with antiretroviral therapy (ART), particularly in the gut‐associated lymphoid tissues in the intestine. The effects of ART on the reservoir size, however, had not been explored fully. In this study, researchers used male Chinese‐origin rhesus macaques to assess the effects of long- and short-term ART on gut infection—across segments of the small and large intestines—in long‐term non‐progressors (LTNPs). They reported that although ART does not eliminate SIV in LTNPs, a longer ART period dramatically reduces SIV infection and diversity in the gut. Further studies are needed to better understand the reduction of HIV gut reservoirs in this context. Supported by ORIP (P51OD011133, P51OD011104), NIAID, NIMH, and NINDS.
Cell-Specific Regulation of Gene Expression Using Splicing-Dependent Frameshifting
Ling et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33523-2
Precise and reliable cell-specific gene delivery remains technically challenging. Investigators report a splicing-based approach for controlling gene expression whereby separate translational reading frames are coupled to the inclusion or exclusion of mutated, frameshifting cell-specific alternative exons. Candidate exons are identified by analyzing thousands of publicly available RNA sequencing datasets and filtering by cell specificity, conservation, and local intron length. This method, which they denote as splicing-linked expression design (SLED), can be combined in a Boolean manner with such existing techniques as minipromoters and viral capsids. SLED can use strong constitutive promoters, without sacrificing precision, by decoupling the tradeoff between promoter strength and selectivity. AAV-packaged SLED vectors can selectively deliver fluorescent reporters and calcium indicators to various neuronal subtypes in vivo. The authors also demonstrate gene therapy utility by creating SLED vectors that can target PRPH2 and SF3B1 mutations. The flexibility of SLED technology enables creative avenues for basic and translational research. Supported by ORIP (T32OD011089, S10OD026859), NEI, and NIMH.
Effect of Single Housing on Innate Immune Activation in Immunodeficiency Virus–Infected Pigtail Macaques (Macaca nemestrina) as a Model of Psychosocial Stress in Acute HIV Infection
Castell et al., Psychosomatic Medicine. 2022.
https://www.doi.org/10.1097/PSY.0000000000001132
Psychosocial stress is associated with immune system dysregulation and worsened clinical outcomes in people with HIV. Investigators performed a retrospective analysis of acute simian immunodeficiency virus (SIV) infection of male pigtail macaques to compare the innate immune responses of social and single housing. The singly housed macaques showed reduced expansion of classical and intermediate monocytes, prolonged thrombocytopenia, and suppression of platelet activation during the first 2 weeks after inoculation. These findings indicate that psychosocial stress might induce clinically significant immunomodulatory effects in the innate immune system during acute SIV infection. Supported by ORIP (P40OD013117, K01OD018244, T32OD011089, U42OD013117), NIAID, NIMH, and NINDS.
De Novo Variants in EMC1 Lead to Neurodevelopmental Delay and Cerebellar Degeneration and Affect Glial Function in Drosophila
Chung et al., Human Molecular Genetics. 2022.
https://www.doi.org/10.1093/hmg/ddac053
Variants in EMC1, which encodes a subunit of the endoplasmic reticulum (ER)–membrane protein complex (EMC), are associated with developmental delay in children. Functional consequences of these variants are poorly understood. The investigators identified de novo variants in EMC1 in three children affected by global developmental delay, hypotonia, seizures, visual impairment, and cerebellar atrophy. They demonstrated in Drosophila that these variants are loss-of-function alleles and lead to lethality when expressed in glia but not in neurons. This work suggests the causality of EMC variants in disease. Supported by ORIP (R24OD022005, R24OD031447), NINDS, and NICHD.
Promoting Validation and Cross-Phylogenetic Integration in Model Organism Research
Cheng et al., Disease Models & Mechanisms. 2022.
https://www.doi.org/10.1242/dmm.049600
Model organisms are essential for biomedical research and therapeutic development, but translation of such research to the clinic is low. The authors summarized discussions from an NIH virtual workshop series, titled “Validation of Animal Models and Tools for Biomedical Research,” held from 2020 to 2021. They described challenges and opportunities for developing and integrating tools and resources and provided suggestions for improving the rigor, validation, reproducibility, and translatability of model organism research. Supported by ORIP (R01OD011116, R24OD031447, R03OD030597, R24OD018559, R24OD017870, R24OD026591, R24OD022005, U42OD026645, U42OD012210, U54OD030165, UM1OD023221, P51OD011107), NIAMS, NIDDK, NIGMS, NHGRI, and NINDS.
Lesion Environments Direct Transplanted Neural Progenitors Towards a Wound Repair Astroglial Phenotype in Mice
O’Shea et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33382-x
Neural progenitor cells (NPCs) are potential cell transplantation therapies for central nervous system (CNS) injuries. Investigators derived NPCs expressing a ribosomal protein-hemagglutinin tag (RiboTag) for transcriptional profiling. Their findings reveal similarities between the transcriptional profiles, cellular morphologies, and functional features of cells transplanted into subacute CNS lesions and host astroglia. The astroglia are stimulated by injuries to proliferate and adopt a naturally occurring, border-forming wound repair phenotype in mice of both sexes. Understanding the autonomous cues instructing NPCs transplanted in CNS host tissue will be fundamental to therapeutic NPC transplantation. Supported by ORIP (U42OD010921,U42OD011174, UM1OD023222) and NINDS.