Selected Grantee Publications
Senescent-like Microglia Limit Remyelination Through the Senescence Associated Secretory Phenotype
Gross et al., Nature Communications. 2025.
https://www.nature.com/articles/s41467-025-57632-w
Multiple sclerosis (MS) is a chronic, immune-mediated demyelinating disease in which immune cells infiltrate the central nervous system and promote deterioration of myelin and neurodegeneration. The capacity to regenerate myelin in the central nervous system diminishes with age. In this study, researchers used 2- to 3-month-old (young), 12-month-old (middle-aged), and 18- to 22-month-old (aged) C57BL/6 male and female mice. Results showed an upregulation of the senescence marker P16ink4a (P16) in microglial and macrophage cells within demyelinated lesions. Notably, treatment of senescent cells using genetic and pharmacological senolytic methods leads to enhanced remyelination in young and middle-aged mice but fails to improve remyelination in aged mice. These results suggest that therapeutic targeting of senescence-associated secretory phenotype components may improve remyelination in aging and MS. Supported by ORIP (R24OD036199), NIA, NINDS, and NIMH.
Dysregulation of mTOR Signalling Is a Converging Mechanism in Lissencephaly
Zhang et al., Nature. 2025.
https://pubmed.ncbi.nlm.nih.gov/39743596
Lissencephaly (smooth brain) is a rare genetic condition, with such symptoms as epilepsy and intellectual disability and a median life expectancy of 10 years. This study reveals that reduced activity of the mTOR pathway may be a common cause of lissencephaly. Researchers used laboratory-grown brain models (organoids) and sequencing and spectrometry techniques to identify decreased mTOR activation in two types of lissencephaly disorders: p53-induced death domain protein 1 and Miller–Dieker lissencephaly syndrome. Pharmacological activation of mTOR signaling with a brain-selective mTORC1 activator molecule, NV-5138, prevented and reversed the morphological and functional defects in organoids. These findings suggest that mTOR dysregulation contributes to the development of lissencephaly spectrum disorders and highlight a potential druggable pathway for therapy. Supported by ORIP (S10OD018034, S10OD019967, S10OD030363), NCATS, NHGRI, NICHD, NIDA, NIGMS, NIMH, and NINDS.
Single-Cell Transcriptomics Predict Novel Potential Regulators of Acute Epithelial Restitution in the Ischemia-Injured Intestine
Rose et al., American Journal of Physiology-Gastrointestinal and Liver Physiology. 2025.
https://pubmed.ncbi.nlm.nih.gov/39853303
Following ischemia in the small intestine, early barrier restoration relies on epithelial restitution to reseal the physical barrier and prevent sepsis. Pigs share a similar gastrointestinal anatomy, physiology, and microbiota with humans. Researchers used neonatal and juvenile, 2- to 6-week-old male and female Yorkshire cross pigs to determine upstream regulators of restitution. Single-cell sequencing of ischemia-injured epithelial cells demonstrated two sub-phenotypes of absorptive enterocytes, with one subset presenting a restitution phenotype. Colony-stimulating factor-1 (CSF1) was the only predicted upstream regulator expressed in juvenile jejunum compared with neonatal jejunum. An in vitro scratch wound assay using IPEC-J2 cells showed that BLZ945, a colony-stimulating factor 1 receptor antagonist, inhibited restitution. Ex vivo ischemia-injured neonatal pig jejunum treated with exogenous CSF1 displayed increased barrier function. This study could inform future research focused on developing novel therapeutics for intestinal barrier injury in patients. Supported by ORIP (T32OD011130, K01OD028207), NCATS, NICHD, and NIDDK.
Plural Molecular and Cellular Mechanisms of Pore Domain KCNQ2 Encephalopathy
Abreo et al., eLife. 2025.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11703504
This study investigates the cellular and molecular mechanisms underlying KCNQ2 encephalopathy, a severe type of early-onset epilepsy caused by mutations in the KCNQ2 gene. Researchers describe a case study of a child with a specific KCNQ2 gene mutation, G256W, and found that it disrupts normal brain activity, leading to seizures and developmental impairments. Male and female Kcnq2G256W/+ mice have reduced KCNQ2 protein levels, epilepsy, brain hyperactivity, and premature deaths. As seen in the patient study, ezogabine treatment rescued seizures in mice, suggesting a potential treatment avenue. These findings provide important insights into KCNQ2-related epilepsy and highlight possible therapeutic strategies. Supported by ORIP (U54OD020351, S10OD026804, U54OD030187), NCI, NHLBI, NICHD, NIGMS, NIMH, and NINDS.
The Widely Used Ucp1-Cre Transgene Elicits Complex Developmental and Metabolic Phenotypes
Halurkar et al., Nature Communications. 2025.
https://pubmed.ncbi.nlm.nih.gov/39824816
Bacterial artificial chromosome technology is instrumental to mouse transgenics, including in studies of highly thermogenic brown adipose tissue and energy-storing white adipose tissue. Researchers discovered that male and female Ucp1-CreEvdr transgenic mice, which are commonly used to study fat tissue, may have unintended effects on metabolism and development. Findings revealed that these mice show changes in both brown and white fat function and disruptions in gene activity, suggesting broader physiological impacts than previously thought. This study emphasizes the need for careful validation of genetic tools in research to ensure accurate results, highlighting the potential concerns in using the Ucp1-CreEvdr model in metabolic and developmental studies. Supported by ORIP (R21OD034470, R21OD031907) NCATS, NIDCR, and NIDDK.
A Switch from Glial to Neuronal Gene Expression Alterations in the Spinal Cord of SIV-Infected Macaques on Antiretroviral Therapy
Mulka et al., Journal of Neuroimmune Pharmacology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38862787/
Up to one-third of patients with HIV experience HIV-associated peripheral neuropathy, affecting sensory pathways in the spinal cord. Spinal cord sampling is limited in people with HIV. Researchers examined gene expression alterations in the spinal cords of simian immunodeficiency virus (SIV)-infected male pigtail macaques with and without antiretroviral therapy (ART), using RNA sequencing at key time points throughout infection. Results indicate a shift from glial cell-associated pathways to neuronal pathways in SIV-infected animals receiving ART. These findings suggest that neurons, rather than glia, are predominantly involved in ART-related neurotoxicity and offer new insights into therapeutic strategies for maintaining synaptic homeostasis. Supported by ORIP (U42OD013117, T32OD011089) and NINDS.
Aberrant Activation of Wound-Healing Programs within the Metastatic Niche Facilitates Lung Colonization by Osteosarcoma Cells
Reinecke et al., Clinical Cancer Research. 2024.
https://pmc.ncbi.nlm.nih.gov/articles/PMC11739783/
The leading cause of deaths in the pediatric osteosarcoma is due to lung metastasis. A current clinical need is the development of therapies that disrupt the later stages of metastasis. Researchers used 6- to 8-week-old female C57BL/6 and CB17-SCID mice to understand how tumor cells disrupt the lung microenvironment to promote tumor growth. Single-cell RNA sequencing and spatial transcriptomics demonstrated osteosarcoma–epithelial cell interactions in a chronic state of wound healing in the lung. Nintedanib administration significantly disrupted metastatic progression compared with the vehicle control, demonstrating a potential novel therapeutic for combating osteosarcoma lung metastasis. Supported by ORIP (K01OD031811), NCI, and NCATS.
Lipid Nanoparticle-Mediated mRNA Delivery to CD34+ Cells in Rhesus Monkeys
Kim et al., Nature Biotechnology. 2024.
https://pubmed.ncbi.nlm.nih.gov/39578569
Blood cells, which are derived from hematopoietic stem cells (HSCs), promote pathologies including anemia, sickle cell disease, immunodeficiency, and metabolic disorders when dysfunctional. Because of the morbidity that results from the bone marrow mobilization and chemotherapy patient conditioning of current HSC therapies, novel treatment strategies that deliver RNA to HSCs are needed. Researchers found a lipid nanoparticle (LNP), LNP67, that delivers messenger RNA (mRNA) to murine HSCs in vivo and human HSCs ex vivo without the use of a cKit-targeting ligand. When tested in 7- to 8-month-old male and female rhesus monkeys, LNP67 successfully delivered mRNA to CD34+ cells and liver cells without adverse effects. These results show the potential translational relevance of an in vivo LNP–mRNA drug. Supported by ORIP (U42OD027094, P51OD011107), NIDDK, and NCATS.
Multimodal Analysis of Dysregulated Heme Metabolism, Hypoxic Signaling, and Stress Erythropoiesis in Down Syndrome
Donovan et al., Cell Reports. 2024.
https://pubmed.ncbi.nlm.nih.gov/39120971
Down syndrome (DS), a genetic condition caused by the presence of an extra copy of chromosome 21, is characterized by intellectual and developmental disability. Infants with DS often suffer from low oxygen saturation, and DS is associated with obstructive sleep apnea. Investigators assessed the role that hypoxia plays in driving health conditions that are comorbid with DS. A multiomic analysis showed that people with DS exhibit elevated heme metabolism and activated stress erythropoiesis, which are indicators of chronic hypoxia; these results were recapitulated in a mouse model for DS. This study identified hypoxia as a possible mechanism underlying several conditions that co-occur with DS, including congenital heart defects, seizure disorders, autoimmune disorders, several leukemias, and Alzheimer's disease. Supported by ORIP (R24OD035579), NCATS, NCI, and NIAID.
Impaired Axon Initial Segment Structure and Function in a Model of ARHGEF9 Developmental and Epileptic Encephalopathy
Wang et al., PNAS. 2024.
https://www.pnas.org/doi/10.1073/pnas.2400709121
Researchers developed a mouse model carrying the G55A missense variant identified in ARHGEF9 patients with severe epilepsy and neurodevelopmental phenotypes. Using male Arhgef9G55A mice, this study examined behavioral, molecular, and electrophysiological phenotypes in the Arhgef9G55A model of developmental and epileptic encephalopathies (DEE). Researchers found that the G55A variant causes disruption of inhibitory postsynaptic organization and axon initial segment (AIS) architecture, leading to impairment of both synaptic transmission and action potential generation. The effects of Arhgef9G55A on neuronal function affect both intrinsic and synaptic excitability and preferentially impair AIS. These findings indicate a novel pathological mechanism of DEE and represent a unique example of a neuropathological condition converging from AIS dysfunctions. Supported by ORIP (U54OD020351, U54OD030187, U54OD020351, S10OD026974) and NINDS.