The catalytic performance and therapeutic effect of nanoparticles varies with shape. Here, we investigated and compared the therapeutic outcomes of ceria nanospheres (Ceria NSs) and ceria nanorods (Ceria NRs) in an in vivo study of mild traumatic brain injury (mTBI). In vivo TBI was induced in a mouse model of open head injury using a stereotaxic impactor. Outcomes including cytoprotective effects, cognitive function, and cerebral edema were investigated after retro-orbital injection of 11.6 mM of ceria nanoparticles. Ceria nanoparticles significantly reduced fluoro-jade B (FJB)-positive cells and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells, and restored mRNA levels of superoxide dismutase 1 (SOD1) and SOD2. They also decreased the cyclooxygenase-2 (COX-2) expression compared with the untreated control group. Comparing the two nanomaterials, Ceria NRs showed less stable and high-energy (100) and (110) planes, which increased the number of active sites. The Ce3+/Ce4+ molar ratio of Ceria NRs (0.40) was greater than that of Ceria NSs (0.27). Ceria NRs (0.059 ± 0.021) appeared to exhibit better anti-inflammatory effect than Ceria NSs (0.133 ± 0.024), but the effect was statistically insignificant (p = 0.190). Ceria nanoparticles also improved cognitive impairment following mTBI compared with the control group, but the effect did not differ significantly according to the nanoshape. However, Ceria NRs (70.1 ± 0.5%) significantly decreased brain water content compared with Ceria NSs (73.7 ± 0.4%; p = 0.0015), indicating a more effective reduction in brain edema (p = 0.0015). Compared with Ceria NSs, the Ceria NRs are more effective in alleviating cerebral edema following in vivo mTBI.

Decreased mitochondrial membrane potential in cerebrospinal fluid (CSF) was observed in patients with subarachnoid hemorrhage (SAH) accompanied by delayed cerebral ischemia (DCI). However, whether abnormal mechanisms of mitochondria are associated with the development of DCI has not been reported yet. Under cerebral ischemia, mitochondria can transfer into the extracellular space. Mitochondrial dysfunction can aggravate neurologic complications. The objective of this study was to evaluate whether mitochondrial dysfunction might be associated with autophagy and mitophagy in CSF cells to provide possible insight into DCI pathogenesis. CSF samples were collected from 56 SAH patients (DCI, n = 21; and non-DCI, n = 35). We analyzed CSF cells using autophagy and mitophagy markers (DAPK1, BNIP3L, BAX, PINK1, ULK1, and NDP52) via qRT-PCR and western blotting of proteins (BECN1, LC3, and p62). Confocal microscopy and immunogold staining were performed to demonstrate the differentially expression of markers within dysfunctional mitochondria. Significant induction of autophagic flux with accumulation of autophagic vacuoles, increased expression of BECN1, LC3-II, and p62 degradation were observed during DCI. Compared to non-DCI patients, DCI patients showed significantly increased mRNA expression levels (2−ΔCt) of DAPK1, BNIP3L, and PINK1, but not BAX, ULK1, or NDP52. Multivariable logistic regression analysis revealed that Hunt and Hess grade ≥ IV (p = 0.023), DAPK1 (p = 0.003), and BNIP3L (p = 0.039) were related to DCI. Increased mitochondrial dysfunction associated with autophagy and mitophagy could play an important role in DCI pathogenesis.

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Little is known about the epigenetic changes associated with delayed cerebral ischemia (DCI) pathogenesis after subarachnoid hemorrhage (SAH). Here, we investigated genome-wide DNA methylation profiles specifically associated with DCI, which is a major contributor to poor clinical outcomes. An epigenome-wide association study (EWAS) and quantitative real-time PCR (qRT-PCR) were conducted in 40 SAH patients (DCI, n = 13; non-DCI, n = 27). A replication study using bisulfite modification and methylation-specific PCR was further performed in 36 patients (DCI, n = 12; non-DCI, n = 24). The relative degree of methylation was described as the median and 25th-75th percentile. No significant differences in clinical characteristics between DCI and non-DCI groups were observed. Among the top 10 differentially methylated genes analyzed via EWAS, two aberrantly methylated CpG sites of cg00441765 (INSR gene) and cg11464053 (CDHR5 gene) were associated with decreased mRNA expression (2 −ΔCt). They include INSR [0.00020 (0.00012-0.00030) in DCI vs. 0.00050 (0.00030-0.00068) in non-DCI] and CDHR5 [0.114 (0.053-0.143) in DCI vs. 0.170 (0.110-0.212) in non-DCI]. Compared with non-DCI cases, patients with DCI exhibited an increased degree of methylation in the replication study: INSR, 0.855 (0.779-0.913) in DCI vs. 0.582 (0.565-0.689) in non-DCI; CDHR5, 0.786 (0.708-0.904) in DCI vs. 0.632 (0.610-0.679) in non-DCI. Hypermethylation of two novel genes, INSR and CDHR5 may serve as a biomarker for early detection of DCI following SAH. Delayed cerebral ischemia (DCI) is a major contributor to poor neurologic outcomes in patients diagnosed with subarachnoid hemorrhage (SAH) 1. However, it is also a preventable and treatable complication. Well-known risk factors for DCI include female gender, cigarette smoking, hyperglycemia, high Hunt-Hess (HH) grade and thick hemorrhage at admission 1-3. The majority of genetic studies investigating DCI have focused on gene expression or linkage analyses of candidate genes 4. Candidate genes include those associated with inflammation, endothelial dysfunction, fibrinolysis, and brain metabolism. A previous meta-analysis 5 showed that ApoE ε4 carriers had a higher risk of DCI than non-ε4 carriers. Kim et al. 6 reported that DCI was more frequently observed in patients expressing haptoglobin (Hp) 2-2 than Hp 1-1 phenotype. In particular, SAH patients with Hp 2-1, and non-DCI patients showed higher α1intensities than DCI patients. A genome-wide association study (GWAS) 7 revealed that SNP rs999662 encompassing solute carrier family 12 member 3 (SLC12A3) was significantly associated with high transcranial Doppler (TCD) velocities, such as angiographic vasospasm, which leads to DCI 7. Genetic background accounts for approximately 37.9% of stroke pathogenesis 8-10. However, the frequency of susceptible genetic variants in stroke patients varies between 5 and 10% 9 , which indicates cryptic genetic changes beyond DNA sequences 8,11. One of these cryptic variations involving novel epigenetic pathways is DNA

BackgroundTo assess the association of haptoglobin (Hp) phenotype with neurological and cognitive outcomes in a large cohort of patients with subarachnoid hemorrhage (SAH).MethodsThis prospective multicenter study enrolled patients with aneurysmal SAH between May 2015 and September 2020. The Hp phenotype was confirmed via Western blots. The relative intensities of α1 in individuals carrying Hp2-1 were compared with those of albumin. Multivariable logistic and Cox proportional-hazard regression analyses were used to identify the risk factors for 6-month and long-term outcomes, respectively.ResultsA total of 336 patients including the phenotypes Hp1-1 (n = 31, 9.2%), Hp2-1 (n = 126, 37.5%), and Hp2-2 (n = 179, 53.3%) were analyzed. The Hp phenotype was closely associated with 6-month outcome (p = 0.001) and cognitive function (p = 0.013), and long-term outcome (p = 0.002) and cognitive function (p < 0.001). Compared with Hp1-1 as the reference value, Hp2-2 significantly increased the risk of 6-month poor outcome (OR: 7.868, 95% CI: 1.764–35.093) and cognitive impairment (OR: 8.056, 95% CI: 1.020–63.616), and long-term poor outcome (HR: 5.802, 95% CI: 1.795–18.754) and cognitive impairment (HR: 7.434, 95% CI: 2.264–24.409). Long-term cognitive impairment based on the Hp phenotype was significantly higher in patients under 65 years of age (p < 0.001) and female gender (p < 0.001). A lower relative α1/albumin intensity (OR: 0.010, 95% CI: 0.000–0.522) was associated with poor outcome at 6 months but not cognitive impairment in patients with SAH expressing Hp2-1.ConclusionHp2-2 increased the risk of poor neurological outcomes and cognitive impairment compared with Hp1-1. For Hp2-1, higher relative α1 intensities were related to 6-month favorable outcomes.