ABSTRACT
Objective:To analyze the incidence and epidemiological characteristics of traumatic spinal cord injury in China in 2018.Methods:Multi-stage stratified cluster sampling was used to randomly select hospitals capable of treating patients with spinal cord injury from 3 regions，9 provinces and 27 cities in China to retrospectively investigate eligible patients with traumatic spinal cord injury admitted in 2018. National and regional incidence rates were calculated. The data of cause of injury，injury level，severity of injury，segment and type of fracture，complications，death and other data were collected by medical record questionnaire，and analyzed according to geographical region，age and gender.Results:Medical records of 4，134 patients were included in this study，with a male-to-female ratio of 2.99∶1. The incidence of traumatic spinal cord injury in China in 2018 was 50.484 / 1 million （95% CI 50.122-50.846）. The highest incidence in the Eastern region was 53.791 / 1 million （95% CI 53.217-54.365）. In the whole country，the main causes of injury were high falls （29.58%），as well as in the Western region （40.68%），while the main causes of injury in the Eastern and Central regions were traffic injuries （31.22%，30.10%）. The main injury level was cervical spinal cord in the whole country （64.49%），and the proportion of cervical spinal cord injury in the Central region was the highest （74.68%），and the proportion of lumbosacral spinal cord injury in the Western region was the highest （32.30%）. The highest proportion of degree of injury was incomplete quadriplegia （55.20%），and the distribution pattern was the same in each region. A total of 65.87% of the patients were complicated with fracture or dislocation，77.95% in the Western region and only 54.77% in the Central region. In the whole country，the head was the main combined injury （37.87%），as well as in the Eastern and Central regions，while the proportion of chest combined injury in the Western region was the highest （38.57%）. A total of 32.90% of the patients were complicated with respiratory complications. There were 23 patients （0.56%） died in hospital，of which 17（73.91%） died of respiratory dysfunction. Conclusions:The Eastern region of China has a high incidence of traumatic spinal cord injury. Other epidemiological features include high fall as the main cause of injury cervical spinal cord injury as the main injury level，incomplete quadriplegia as the main degree of injury，head as the main combined injury，and respiratory complications as the main complication.
ABSTRACT
GGGGCC repeat expansions in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (c9ALS/FTD). It has been reported that hexanucleotide repeat expansions in C9ORF72 produce five dipeptide repeat (DPR) proteins by an unconventional repeat-associated non-ATG (RAN) translation. Within the five DPR proteins, poly-PR and poly-GR that contain arginine are more toxic than the other DPRs (poly-GA, poly-GP, and poly-PA). Here, we demonstrated that poly-PR peptides transferred into cells by endocytosis in a clathrin-dependent manner, leading to endoplasmic reticulum stress and cell death. In SH-SY5Y cells and primary cortical neurons, poly-PR activated JUN amino-terminal kinase (JNK) and increased the levels of p53 and Bax. The uptake of poly-PR peptides by cells was significantly inhibited by knockdown of clathrin or by chlorpromazine, an inhibitor that blocks clathrin-mediated endocytosis. Inhibition of clathrin-dependent endocytosis by chlorpromazine significantly blocked the transfer of poly-PR peptides into cells, and attenuated poly-PR-induced JNK activation and cell death. Our data revealed that the uptake of poly-PR undergoes clathrin-dependent endocytosis and blockade of this process prevents the toxic effects of synthetic poly-PR peptides.