14 research outputs found
Defective autophagy is associated with neuronal injury in a mouse model of multiple sclerosis
Neurodegeneration, along with inflammatory demyelination, is an important component of multiple sclerosis (MS) pathogenesis. Autophagy is known to play a pivotal role in neuronal homeostasis and is implicated in several neurodegenerative disorders. However, whether autophagy is involved in the mechanisms of neuronal damage during MS remains to be investigated. Experimental autoimmune encephalomyelitis (EAE), an in vivo model of MS, was induced in female C57BL/6 mice by immunization with myelin oligodendrocyte glycoprotein p35-55. After that, autophagic flux in the spinal cord of mice was evaluated by detection of LC3-II and Beclin1 protein expressions. EAE mice were then administered with rapamycin and 3-methyladenine (3-MA) for 10 days. Afterward, the changes in LC3-II, Beclin1, and p62 expression, number of infiltrated inflammatory cells, demyelinated lesion area, and neuronal damage, as well as clinical scores, were assessed. Further, apoptotic cell rate and apoptosis-related protein expressions were monitored. We observed an impaired autophagic flux and increased neuronal damage in the spinal cords of EAE mice. We also found that rapamycin, an autophagy inducer, mitigated EAE-induced autophagy decrease, inflammation, demyelination and neuronal injury, as well as the abnormal clinical score. In addition, rapamycin suppressed cell apoptosis, and decreased Bax/Bcl-2 ratio and cleaved caspase-3 expression. Conversely, the effect of autophagy inhibitor 3-MA on EAE mice resulted in completely opposite results. These results indicated that autophagy deficiency, at least in part, contributed to EAE-induced neuronal injury and that pharmacological modulation of autophagy might be a therapeutic strategy for MS
Efficient biosynthesis of pinosylvin from lignin-derived cinnamic acid by metabolic engineering of Escherichia coli
Abstract Background The conversion of lignin-derived aromatic monomers into valuable chemicals has promising potential to improve the economic competitiveness of biomass biorefineries. Pinosylvin is an attractive pharmaceutical with multiple promising biological activities. Results Herein, Escherichia coli was engineered to convert the lignin-derived standard model monomer cinnamic acid into pinosylvin by introducing two novel enzymes from the wood plant: stilbene synthase from Pinus pinea (PpSTS) and 4-Coumarate-CoA ligase from Populus trichocarpa (Ptr4CL4). The expression of Ptr4CL4 drastically improved the production of pinosylvin (42.5 ± 1.1 mg/L), achieving values 15.7-fold higher than that of Ptr4CL5 (another 4-Coumarate-CoA ligase from Populus trichocarpa) in the absence of cerulenin. By adjusting the expression strategy, the optimized engineered strain produced pinosylvin at 153.7 ± 2.2 mg/L with an extremely high yield of 1.20 ± 0.02 mg/mg cinnamic acid in the presence of cerulenin, which is 83.9% ± 1.17 of the theoretical yield. This is the highest reported pinosylvin yield directly from cinnamic acid to date. Conclusion Our work highlights the feasibility of microbial production of pinosylvin from cinnamic acid and paves the way for converting lignin-related aromatics to valuable chemicals
Current Development Status and Consideration for Rare Hemorrhagic Disease Drugs
Hemophilia is the only rare hereditary hemorrhagic disorder included in the First Rare Diseases catalogue. However, rare bleeding diseases identified in the clinic are far more common than hemophilia. Most other rare hemorrhagic disorders have less effective treatment than hemophilia. Hemophilia has a history of successful drug development in rare hemorrhagic diseases, and the cycle between clinical research and drug development has been gradually realized. Drug research and pharmaceutical companies can refer to the drug research and development process in the field of hemophilia, learn from the experience of hemophilia drug research and develop treatments. The industry can increase drug development by strengthening basic research, focusing on the value of natural history research, the application of quantitative pharmacological tools and improving the efficiency of drug development to meet the urgent unmet medical needs of patients with rare hemorrhagic diseases
Study on the significance of MRI and cerebrospinal fluid cytology in the diagnosis of viral encephalitis (meningitis)
Objective To explore the significance of magnetic resonance imaging (MRI) and cerebrospinal fluid cytology in the diagnosis and treatment of viral encephalitis (meningitis). Methods The head MRI and cerebrospinal fluid data of 189 patients with viral encephalitis (meningitis) were reviewed, and early changes of cerebrospinal fluid cyotology of patients with normal or abnormal MRI findings were analysed retrospectively. Results Among 189 viral encephalitis (meningitis) patients, 96 (50.79%) patients presented abnormal MRI, and 129 (68.25%) patients presented abnormal cerebrospinal fluid cytological findings. In patients with abnormal MRI the abnormality rate of cerebrospinal fluid cytological findings was 72.92% (70/96), while in patients with normal MRI it was 63.44% (59/93), the difference was significant (P = 0.000). Conclusion In the early stage of viral encephalitis (meningitis) MRI changes appear later than abnormal cerebrospinal fluid cytological findings, but both of them are important for clinical diagnosis and treatment of this disease.
DOI:10.3969/j.issn.1672-6731.2011.05.01
The therapeutic value of cerebrospinal fluid ctDNA detection by next-generation sequencing for meningeal carcinomatosis: a case report
Abstract Background It is usually very complicated to treat meningeal carcinomatosis, and it is important to treat it as soon as possible. Case presentation The 19-Del mutation was found in the exon for the epidermal growth factor receptor gene in the pleural effusion of a patient on March 11th, 2015. He took 250 mg of oral gefitinib once a day for 11 months beginning in December of 2015. On the 3rd of November 2016, he arrived at the hospital and presented with dizziness, headache and transient blurred vision. At this time, he began to take 4 mg of oral zoledronic acid once a month to prevent bone metastases. The result of a cytology exam of the cerebrospinal fluid showed that the man had meningeal carcinomatosis. The 19-Del mutation and the 20-T790 M mutation in the exon of the epidermal growth factor receptor gene was found by the next generation sequencing of the CSF. Then, he discontinued taking gefitinib and began to take 90–100 mg of oral AZD9291 once a day in November 2016. After adjusting the medication dose based on the NGS, his headache was noticeably reduced, and his condition gradually stabilized. Conclusions Cerebrospinal fluid ctDNA detection by next generation sequencing may become a suitable biomarker to monitor clinical treatment response in meningeal carcinomatosis
The gamma-aminobutyric acid-B receptor (GABAB) encephalitis: clinical manifestations and response to immunotherapy
Genomic alterations of cerebrospinal fluid cell-free DNA in leptomeningeal metastases of gastric cancer
Abstract Background Leptomeningeal metastases (LM) were rare in gastric cancer (GC), and GC patients with LM (GCLM) generally suffer from poor prognosis. Nevertheless, the clinical utility of cerebrospinal fluid (CSF) circulating tumor DNA (ctDNA) was underinvestigated in GCLM. Methods We retrospectively studied 15 GCLM patients, and all patients had paired primary tumor tissue samples and post-LM CSF samples while 5 patients also had post-LM plasma samples. All samples were analyzed using next-generation sequencing (NGS), and the molecular and clinical features were correlated with clinical outcomes. Results CSF had higher mutation allele frequency (P = 0.015), more somatic mutations (P = 0.032), and more copy-number variations (P < 0.001) than tumor or plasma samples. Multiple genetic alterations and aberrant signal pathways were enriched in post-LM CSF, including CCNE1 amplification and cell cycle-related genes, and CCNE1 amplification was significantly associated with patients’ overall survival (P = 0.0062). More potential LM progression-related markers were detected in CSF samples than in tumor samples, including PREX2 mutation (P = 0.014), IGF1R mutation (P = 0.034), AR mutation (P = 0.038), SMARCB1 deletion (P < 0.001), SMAD4 deletion (P = 0.0034), and TGF-beta pathway aberration (P = 0.0038). Additionally, improvement in intracranial pressure (P < 0.001), improvement in CSF cytology (P = 0.0038), and relatively low levels of CSF ctDNA (P = 0.0098) were significantly associated with better PFS. Lastly, we reported a GCLM case whose CSF ctDNA dynamic changes were well correlated with his clinical assessment. Conclusions CSF ctDNA could more sensitively detect molecular markers and metastasis-related mechanisms than tumor tissues in GCLM patients, and our study sheds light on utilizing CSF ctDNA in prognostic estimation and clinical assessment in GCLM
Retrieving Soil Moisture in the Permafrost Environment by Sentinel-1/2 Temporal Data on the Qinghai–Tibet Plateau
Soil moisture (SM) products presently available in permafrost regions, especially on the Qinghai–Tibet Plateau (QTP), hardly meet the demands of evaluating and modeling climatic, hydrological, and ecological processes, due to their significant bias and low spatial resolution. This study developed an algorithm to generate high-spatial-resolution SM during the thawing season using Sentinel-1 (S1) and Sentinel-2 (S2) temporal data in the permafrost environment. This algorithm utilizes the seasonal backscatter differences to reduce the effect of surface roughness and uses the normalized difference vegetation index (NDVI) and the normalized difference moisture index (NDMI) to characterize vegetation contribution. Then, the SM map with a grid spacing of 50 m × 50 m in the hinterland of the QTP with an area of 505 km × 246 km was generated. The results were independently validated based on in situ data from active layer monitoring sites. It shows that this algorithm can retrieve SM well in the study area. The coefficient of determination (R2) and root-mean-square error (RMSE) are 0.82 and 0.06 m3/m3, respectively. This study analyzed the SM distribution of different vegetation types: the alpine swamp meadow had the largest SM of 0.26 m3/m3, followed by the alpine meadow (0.23), alpine steppe (0.2), and alpine desert (0.16), taking the Tuotuo River basin as an example. We also found a significantly negative correlation between the coefficient of variation (CV) and SM in the permafrost area, and the variability of SM is higher in drier environments and lower in wetter environments. The comparison with ERA5-Land, GLDAS, and ESA CCI showed that the proposed method can provide more spatial details and achieve better performance in permafrost areas on QTP. The results also indicated that the developed algorithm has the potential to be applied in the entire permafrost regions on the QTP