Highlights d Characterization and interactive browser of ependymoma single cells d Identification of progenitor, ependyma-differentiated, and mesenchymal cell types d Subpopulation proportions influence bulk-tumor transcriptomic molecular subgrouping d Progenitor and mesenchymal subpopulations co-localize in peri-necrotic zones Authors

Background Medulloblastoma (MB) is a heterogeneous disease in which neoplastic cells and associated immune cells contribute to disease progression. We aimed to determine the influence of neoplastic and immune cell diversity on MB biology in patient samples and animal models. Methods To better characterize cellular heterogeneity in MB we used single-cell RNA sequencing, immunohistochemistry and deconvolution of transcriptomic data to profile neoplastic and immune populations in patient samples and animal models across childhood MB subgroups. Results Neoplastic cells cluster primarily according to individual sample of origin which is influenced by chromosomal copy number variance. Harmony alignment reveals novel MB subgroup/subtype-associated subpopulations that recapitulate neurodevelopmental processes, including photoreceptor and glutamatergic neuron-like cells in molecular subgroups GP3 and GP4, and a specific nodule-associated neuronally-differentiated subpopulation in subgroup molecular SHH. We definitively chart the spectrum of MB immune cell infiltrates, which include subpopulations that recapitulate developmentally-related neuron-pruning and antigen presenting myeloid cells. MB cellular diversity matching human samples is mirrored in subgroup-specific mouse models of MB. Conclusions These findings provide a clearer understanding of the diverse neoplastic and immune cell subpopulations that constitute the MB microenvironment.

The objective of this investigation was to develop a thermosensitive vaginal gel containing raltegravir + efavirenz loaded PLGA nanoparticles (RAL-EFV-NPs) for pre-exposure prophylaxis of HIV. RAL-EFV-NPs were fabricated using a modified emulsion-solvent evaporation method and characterized for size and zeta potential. The average size and surface charge of RALEFV-NP were 81.8 ± 6.4 nm and −23.18 ± 7.18 mV respectively. The average encapsulation efficiency of raltegravir and efavirenz was 55.5% and 98.2% respectively. Thermosensitive vaginal gel containing RAL-EFV-NPs was successfully prepared using a combination of Pluronic F127 (20% w/v) and Pluronic F68 (1% w/v). Incorporation RAL-EFV-NPs in the gel did not result in nanoparticle aggregation and RAL-EFV-NPs containing gel showed thermogelation at 32.5°C. The RAL-EFV-NPs were evaluated for inhibition of HIV-1NL4-3 using TZM-bl indicator cells. The EC90 of RAL-EFV-NPs was lower than raltegravir + efavirenz (RAL-EFV) solution but did not reach significance. Compared to control HeLa cells without any treatment, RAL-EFV-NPs or blank gel were not cytotoxic for 14 days in vitro. The intracellular levels of efavirenz in RALEFV-NPs treated HeLa cells were above the EC90 for 14 days whereas raltegravir intracellular concentrations were eliminated within 6 days. Transwell experiments of NPs-in-gel demonstrated rapid transfer of fluorescent nanoparticles from the gel and uptake in HeLa cells within 30 min. These data demonstrate the potential of antiretroviral NP-embedded vagina gels for long-term vaginal pre-exposure prophylaxis of heterosexual HIV-1 transmission.

Stroke-induced cerebral ischemia is a major cause of death and disability. The disruption of blood flow results in neuronal and glial cell death leading to brain injury. Reperfusion restores oxygen to the affected tissue, but can also cause damage through an enhanced oxidative stress and inflammatory response. This study examines mitochondrial transfer from MSC to neurons and the role it plays in neuronal preservation after oxidant injury. We observed the transfer of mitochondria from MSC to mouse neurons in vitro following hydrogen peroxide exposure. The observed transfer was dependent on cell-to-cell contact and led to increased neuronal survival and improved metabolism. A number of pro-inflammatory and mitochondrial motility genes were upregulated in neurons after hydrogen peroxide exposure. This included Miro1 and TNFAIP2, linking inflammation and mitochondrial transfer to oxidant injury. Increasing Miro1 expression in MSC improved the metabolic benefit of mitochondrial transfer after neuronal oxidant injury. Decreasing Miro1 expression had the opposite effect, decreasing the metabolic benefit of MSC co-culture. MSC transfer of mitochondria to oxidant-damaged neurons may help improve neuronal preservation and functional recovery after stroke.