Epidemiological age-based differences in traumatic spinal cord injury patients: A multicenter study based on 13,334 inpatients.

CONTEXT: Compared with younger traumatic spinal cord injury (TSCI) patients, the elderly had longer delays in admission to surgery, higher proportion of incomplete injury, and longer hospital stays. However, in China, the country with the largest number of TSCI patients, there have been no large-scale reports on their age differences. OBJECTIVES: To explore the age-based differences among TSCI inpatients, focusing on the demographic and clinical characteristics, treatment status, and economic burden. METHODS: We collected the medical records of 13,334 inpatients with TSCI in the 30 hospitals of China, from January 1, 2013 to December 31, 2018. Trends are expressed as annual percentage changes (APCs) and 95% confidence intervals (CIs). RESULTS: A total of 13,334 inpatients were included. Both the number and proportion of the elderly showed an increasing trend. The APC of the number and proportion in patients ≥85 years were 39.5% (95% CI, 14.3 to 70.3; P < 0.01) and 30.5% (95% CI, 8.6 to 56.9; P < 0.01), respectively. Younger patients were more likely to undergo decompression surgery, and older patients were more likely to receive high-dose methylprednisolone sodium succinate/methylprednisolone (MPSS/MP). Of the patients ≥85 years, none underwent decompression surgery within 8 h, and only 1.4% received a high dose of MPSS/MP within 8 h after injury. Elderly patients had lower hospitalization costs than younger. The total and daily medical costs during hospitalization of patients ≥85 years were 8.06 ± 18.80 (IQR: 5.79) and 0.61 ± 0.73 (IQR: 0.55) thousands dollars, respectively. CONCLUSIONS: As the first study to focus on age differences of TSCI patients in China, this study found many differences, in demographic and clinical characteristics, treatment status, and economic costs, between older and younger TSCI patients. The number and proportion of elderly patients increased, and the rate of early surgery for elderly patients is low.

N1-Methyladenosine modification of mRNA regulates neuronal gene expression and oxygen glucose deprivation/reoxygenation induction.

N1-Methyladenosine (m1A) is an abundant modification of transcripts, plays important roles in regulating mRNA structure and translation efficiency, and is dynamically regulated under stress. However, the characteristics and functions of mRNA m1A modification in primary neurons and oxygen glucose deprivation/reoxygenation (OGD/R) induced remain unclear. We first constructed a mouse cortical neuron OGD/R model and then used methylated RNA immunoprecipitation (MeRIP) and sequencing technology to demonstrate that m1A modification is abundant in neuron mRNAs and dynamically regulated during OGD/R induction. Our study suggests that Trmt10c, Alkbh3, and Ythdf3 may be m1A-regulating enzymes in neurons during OGD/R induction. The level and pattern of m1A modification change significantly during OGD/R induction, and differential methylation is closely associated with the nervous system. Our findings show that m1A peaks in cortical neurons aggregate at both the 5' and 3' untranslated regions. m1A modification can regulate gene expression, and peaks in different regions have different effects on gene expression. By analysing m1A-seq and RNA-seq data, we show a positive correlation between differentially methylated m1A peaks and gene expression. The correlation was verified by using qRT-PCR and MeRIP-RT-PCR. Moreover, we selected human tissue samples from Parkinson's disease (PD) and Alzheimer's disease (AD) patients from the Gene Expression Comprehensive (GEO) database to analyse the selected differentially expressed genes (DEGs) and differential methylation modification regulatory enzymes, respectively, and found similar differential expression results. We highlight the potential relationship between m1A modification and neuronal apoptosis following OGD/R induction. Furthermore, by mapping mouse cortical neurons and OGD/R-induced modification characteristics, we reveal the important role of m1A modification in OGD/R and gene expression regulation, providing new ideas for research on neurological damage.

Sex-related Differences in Epidemiology, Treatment, and Economic Burden of Traumatic Spinal Cord Injury in China (2013-2018).

STUDY DESIGN: Retrospective epidemiological study. OBJECTIVE: To describe differences based on biological sex in the epidemiology and treatment of the economic burden of traumatic spinal cord injury (TSCI) in China (2013-2018). SUMMARY OF BACKGROUND DATA: Although there have been many regional single-center studies on TSCI in China, there are few reports involving multicenter data, especially those that report on discrepancies related to biological sex. MATERIALS AND METHODS: This study is a nationally representative hospital-based retrospective study. The treatment data of TSCI patients in 30 hospitals in 11 provinces/cities from January 2013 to December 2018 were analyzed. Sociodemographic characteristics, accident and related injury characteristics, treatment methods, and hospital costs were obtained. Regression models were used to evaluate differences in the outcomes of interest based on biological sex and other factors. RESULTS: There were 13,465 individuals with TSCI, with a mean age of 50.0 years, and females (52.2) older than males (49.3). Overall, the average ratio of males to females was 3.1:1, ranging from 3.0:1 in 2013 to 2.8:1 in 2018. The overall proportion of patients with TSCI increased from 2013 to 2018 [annual percentage change (APC)=6.8%, 95% CI, 3.3-10.4] ( P < 0.05). The percent increase in females (APC=8.2%, 95% CI, 5.6-10.8) was greater than that of males (APC=6.3%, 95% CI, 2.1-10.6). Overall, high-level falls mainly affected males (30.8%), and low-level falls mainly occurred in females (36.6%). Females demonstrated a higher frequency of thoracolumbar trauma and less severe neurological impairment. CONCLUSIONS: This study suggests that although the main population of TSCI is male, the average ratio of males to females is decreasing. The frequency of TSCI may be increasing faster in females than in males. Therefore, it is necessary to develop sex-specific public prevention measures. In addition, more medical resources should be devoted to improving the ability of hospitals to perform early surgery.

Crosstalk between m6A mRNAs and m6A circRNAs and the time-specific biogenesis of m6A circRNAs after OGD/R in primary neurons.

Cerebral ischaemiareperfusion injury is an important pathological process in nervous system diseases during which neurons undergo oxygenglucose deprivation and reoxygenation (OGD/R) injury. No study has used epitranscriptomics to explore the characteristics and mechanism of injury. N6methyladenosine (m6A) is the most abundant epitranscriptomic RNA modification. However, little is known about m6A modifications in neurons, especially during OGD/R. m6A RNA immunoprecipitation sequencing (MeRIPseq) and RNA-sequencing data for normal and OGD/R-treated neurons were analysed by bioinformatics. MeRIP quantitative real-time polymerase chain reaction was used to determine the m6A modification levels on specific RNAs. We report the m6A modification profiles of the mRNA and circRNA transcriptomes of normal and OGD/R-treated neurons. Expression analysis revealed that the m6A levels did not affect m6A mRNA or m6A circRNA expression. We found crosstalk between m6A mRNAs and m6A circRNAs and identified three patterns of m6A circRNA production in neurons; thus, distinct OGD/R treatments induced the same genes to generate different m6A circRNAs. Additionally, m6A circRNA biogenesis during distinct OGD/R processes was found to be time specific. These results expand our understanding of m6A modifications in normal and OGD/R-treated neurons, providing a reference to explore epigenetic mechanisms and potential treatments for OGD/R-related diseases.

Regulating DNA methylation could reduce neuronal ischemia response and apoptosis after ischemia-reperfusion injury.

BACKGROUND: Ischemia-reperfusion injury (IRI) is an important pathophysiological condition that can cause cell injury and large-scale tissue injury in the nervous system. Previous studies have shown that epigenetic regulation may play a role in the pathogenesis of IRI. METHODS: In this study, we isolated mouse cortical neurons and constructed an oxygen-glucose deprivation/reoxygenation (OGD) model to explore the change in DNA methylation and its effect on the expression of corresponding genes. RESULTS: We found that DNA methylation in neurons increased with hypoxia duration and that hypermethylation of numerous promoters and 3'-untranslated regions increased. We performed Gene Ontology enrichment analysis to study gene function and Kyoto Encyclopedia of Genes and Genomes pathway analysis to identify the pathways associated with gene regulation. The results showed that hypermethylation-related genes expressed after OGD were related to physiological pathways such as neuronal projection, ion transport, growth and development, while hypomethylation-related genes were related to pathological pathways such as the external apoptosis signaling pathway, neuronal death regulation, and regulation of oxidative stress. However, the changes in DNA methylation were specific for certain genes and may have been related to OGD-induced neuronal damage. Importantly, we integrated transcription and DNA methylation data to identify several candidate target genes, including hypomethylated Apoe, Pax6, Bmp4, and Ptch1 and hypermethylated Adora2a, Crhr1, Stxbp1, and Tac1. This study further indicated the effect of DNA methylation on gene function in brain IRI from the perspective of epigenetics, and the identified genes may become new targets for achieving neuroprotection in the brain after IRI.

Clinical features and burden of osteoporotic fractures among the elderly in the USA from 2016 to 2018.

This study provides a national estimate of the incidence of hospitalizations and assesses the clinical features and outcomes during inpatient admission due to osteoporotic fractures diagnosed by ICD-10-CM/PCS among the elderly in the USA, using the US Nationwide Inpatient Sample, 2016-2018. PURPOSE: To provide a national estimate of the incidence of hospitalizations and assess the clinical features and outcomes during inpatient admission due to osteoporotic fractures (OFs) among the elderly in the USA. METHODS: The study included all inpatients aged 65 years and older who participated in the US Nationwide Inpatient Sample (NIS). We conducted a retrospective analysis of hospitalizations with OFs diagnosed by the International Classification of Diseases, Tenth Revision, Clinical Modification/Procedure Coding System (ICD-10-CM/PCS), using the US NIS, 2016-2018. Trends in epidemiological characteristics and outcomes were calculated by annual percentage change (APC). RESULTS: From 2016 to 2018, there were an estimated 0.16 million hospitalizations for OFs, and the estimated annual incidence rate changed from 995 cases per 1 million persons in 2016 to 1114 cases per 1 million persons in 2018 (APC, 5.8% [95% CI, 0.0 to 12.0]; P > 0.05). Over two-thirds of the patients (68.2%) were age-related osteoporosis with current pathological fracture, and OFs were more likely to occur in vertebra (51.7%) and femur (34.7%). During the hospitalization, the average length of stay (LOS) was 5.83 days, the average cost reached $60,901.04, and the overall mortality was 2.3%. All outcomes including LOS, average cost and mortality did not change significantly in 2016-2018 (all P values for trend were over 0.05). CONCLUSION: Between 2016 and 2018, the incidence rate of OFs remained relatively stable, but the total number of cases was huge. OFs was predominantly age-related, mostly in vertebrae and femurs, with relatively stable cost and mortality during hospitalization.

Alteration of mRNA 5-Methylcytosine Modification in Neurons After OGD/R and Potential Roles in Cell Stress Response and Apoptosis.

Epigenetic modifications play an important role in central nervous system disorders. As a widespread posttranscriptional RNA modification, the role of the m5C modification in cerebral ischemia-reperfusion injury (IRI) remains poorly defined. Here, we successfully constructed a neuronal oxygen-glucose deprivation/reoxygenation (OGD/R) model and obtained an overview of the transcriptome-wide m5C profiles using RNA-BS-seq. We discovered that the distribution of neuronal m5C modifications was highly conserved, significantly enriched in CG-rich regions and concentrated in the mRNA translation initiation regions. After OGD/R, modification level of m5C increased, whereas the number of methylated mRNA genes decreased. The amount of overlap of m5C sites with the binding sites of most RNA-binding proteins increased significantly, except for that of the RBM3-binding protein. Moreover, hypermethylated genes in neurons were significantly enriched in pathological processes, and the hub hypermethylated genes RPL8 and RPS9 identified by the protein-protein interaction network were significantly related to cerebral injury. Furthermore, the upregulated transcripts with hypermethylated modification were enriched in the processes involved in response to stress and regulation of apoptosis, and these processes were not identified in hypomethylated transcripts. In final, we verified that OGD/R induced neuronal apoptosis in vitro using TUNEL and western blot assays. Our study identified novel m5C mRNAs associated with ischemia-reperfusion in neurons, providing valuable perspectives for future studies on the role of the RNA methylation in cerebral IRI.