Single-Nucleus Profiling Identifies Accelerated Oligodendrocyte Precursor Cell Senescence in a Mouse Model of Down Syndrome.

Down syndrome (DS), the most common genetic cause of intellectual disability, is associated with lifelong cognitive deficits. However, the mechanisms by which triplication of chromosome 21 genes drive neuroinflammation and cognitive dysfunction are poorly understood. Here, using the Ts65Dn mouse model of DS, we performed an integrated single-nucleus ATAC and RNA-sequencing (snATAC-seq and snRNA-seq) analysis of the adult cortex. We identified cell type-specific transcriptional and chromatin-associated changes in the Ts65Dn cortex, including regulators of neuroinflammation, transcription and translation, myelination, and mitochondrial function. We discovered enrichment of a senescence-associated transcriptional signature in Ts65Dn oligodendrocyte (OL) precursor cells (OPCs) and epigenetic changes consistent with a loss of heterochromatin. We found that senescence is restricted to a subset of OPCs concentrated in deep cortical layers. Treatment of Ts65Dn mice with a senescence-reducing flavonoid rescued cortical OPC proliferation, restored microglial homeostasis, and improved contextual fear memory. Together, these findings suggest that cortical OPC senescence may be an important driver of neuropathology in DS.

Healing Wounds Efficiently with Biomimetic Soft Matter: Injectable Self-Healing Neutral Glycol Chitosan/Dibenzaldehyde-Terminated Poly(ethylene glycol) Hydrogel with Inherent Antibacterial Properties.

The high prevalence of acquiring skin wounds, along with the emergence of antibiotic-resistant strains that lead to infections, impose a threat to the physical, mental, and socioeconomic health of society. Among the wide array of wound dressings developed, hydrogels are regarded as a biomimetic soft matter of choice owing to their ability to provide a moist environment ideal for healing. Herein, neutral glycol chitosan (GC) was cross-linked via imine bonds with varying concentrations of dibenzaldehyde-terminated polyethylene glycol (DP) to give glycol chitosan/dibenzaldehyde-terminated polyethylene glycol hydrogels (GC/DP). These dynamic Schiff base linkages (absorption peak at 1638 cm-1) within the hydrogel structure endowed their ability to recover from damage as characterized by high-low strain exposure in continuous step strain rheology. Along with their good injectability and biodegradability, the hydrogels exhibited remarkable inhibition against E. coli, P. aeruginosa, and S. aureus. GC/DP hydrogels demonstrated high LC50 values in vivo using zebrafish embryos as a model system due to their relative biocompatibility and a remarkable 93.4 ± 0.88% wound contraction at 30-dpw against 49.1 ± 3.40% of the control. To the best of our knowledge, this is the first study that developed injectable glycol chitosan/dibenzaldehyde-terminated polyethylene glycol self-healing hydrogels for application in wound healing with intrinsic bacteriostatic properties against the three bacteria.

The Genomic Architecture of Pregnancy-Associated Plasticity in the Maternal Mouse Hippocampus.

Pregnancy is associated with extraordinary plasticity in the maternal brain. Studies in humans and other mammals suggest extensive structural and functional remodeling of the female brain during and after pregnancy. However, we understand remarkably little about the molecular underpinnings of this natural phenomenon. To gain insight into pregnancy-associated hippocampal plasticity, we performed single nucleus RNA sequencing (snRNA-seq) and snATAC-seq from the mouse hippocampus before, during, and after pregnancy. We identified cell type-specific transcriptional and epigenetic signatures associated with pregnancy and postpartum adaptation. In addition, we analyzed receptor-ligand interactions and transcription factor (TF) motifs that inform hippocampal cell type identity and provide evidence of pregnancy-associated adaption. In total, these data provide a unique resource of coupled transcriptional and epigenetic data across a dynamic time period in the mouse hippocampus and suggest opportunities for functional interrogation of hormone-mediated plasticity.

Acupuncture for a first episode of acute ischaemic stroke: an observer-blinded randomised controlled pilot study.

OBJECTIVE: To determine the required sample size for, and feasibility of, a RCT examining the effectiveness of early acupuncture for acute ischaemic stroke. METHODS: Thirty-eight patients aged 40-85 years with a first episode of acute ischaemic stroke presenting within 72 h of stroke onset were randomly assigned to receive manual acupuncture (MA group; n=20) plus standard care or standard care only (control group, n=18). The acupuncture treatment was provided daily for 2 weeks. The primary outcome was the change in the National Institutes of Health Stroke Scale (NIHSS) score between baseline and 4 weeks. Secondary outcomes included changes in the Fugl-Meyer assessment (FMA) and the functional independence measure scores between baseline and 4 weeks, and changes in NIHSS, Barthel Index and modified Rankin Scale scores at 12 weeks. RESULTS: Thirty-one patients completed the study (dropout rate=18%) and adverse effects were minimal. No significant differences were seen between groups in the improvements in NIHSS scores, although there tended to be a greater reduction in NIHSS score after 1 week in the MA group relative to the control group (p=0.066). The post-stroke motor activity at 4 weeks was associated with a significantly increased FMA score in the acupuncture group compared with the control group (p<0.05), but not supported by intergroup analysis. CONCLUSIONS: This pilot study indicates that acupuncture appears to be safe for patients in the acute stage of ischaemic stroke. A subsequent trial with a larger sample size (estimated at n=122) is required to confirm whether early acupuncture intervention contributes to earlier functional improvement and to assess the longer-term clinical efficacy of acupuncture. TRIAL REGISTRATION NUMBER: NCT02210988; Results.