CHMP2B regulates TDP-43 phosphorylation and cytotoxicity independent of autophagy via CK1

The ESCRT protein CHMP2B and the RNA-binding protein TDP-43 are both associated with ALS and FTD. The pathogenicity of CHMP2B has mainly been considered a consequence of autophagy–endolysosomal dysfunction, whereas protein inclusions containing phosphorylated TDP-43 are a pathological hallmark of ALS and FTD. Intriguingly, TDP-43 pathology has not been associated with the FTD-causing CHMP2B^Intron5 mutation. In this study, we identify CHMP2B as a modifier of TDP-43–mediated neurodegeneration in a Drosophila screen. Down-regulation of CHMP2B reduces TDP-43 phosphorylation and toxicity in flies and mammalian cells. Surprisingly, although CHMP2B^Intron5 causes dramatic autophagy dysfunction, disturbance of autophagy does not alter TDP-43 phosphorylation levels. Instead, we find that inhibition of CK1, but not TTBK1/2 (all of which are kinases phosphorylating TDP-43), abolishes the modifying effect of CHMP2B on TDP-43 phosphorylation. Finally, we uncover that CHMP2B modulates CK1 protein levels by negatively regulating ubiquitination and the proteasome-mediated turnover of CK1. Together, our findings propose an autophagy-independent role and mechanism of CHMP2B in regulating CK1 abundance and TDP-43 phosphorylation.     

MSC derived EV loaded with miRNA-22 inhibits the inflammatory response and nerve function recovery after spinal cord injury in rats

Our previous research has found that miRNA-22 can inhibit the occurrence of pyroptosis by targeting GSDMD and decrease the production and release of inflammatory factors. In consideration of the therapeutic effects of mesenchymal stem cells (MSCs), MSCs-EV were loaded with miRNA-22 (EV-miRNA-22) to investigate the inhibitory effect of EV-miRNA-22 on the inflammatory response in SCI in rats in this study. LPS/Nigericin (LPS/NG) was used to induce pyroptosis in rat microglia in vitro. Propidium iodide (PI) staining was performed to observe cell permeability, lactate dehydrogenase (LDH) release assay was adopted to detect cytotoxicity, flow cytometry was conducted to detect pyroptosis level, immunofluorescence (IF) staining was utilized to observe the expression level of GSDMD (a key protein of pyroptosis), Western blot was performed to detect the expression of key proteins. For animal experiments, the T10 spinal cord of rats was clamped by aneurysm clip to construct the SCI model. BBB score, somatosensory evoked potential (SEP) and motor evoked potential (MEP) were performed to detect nerve function. HE staining and Nissl staining were used to detect spinal cord histopathology and nerve cell damage. EV-miRNA-22 could inhibit the occurrence of pyroptosis in microglia, suppress the cell membrane pore opening, and inhibit the release of inflammatory factors and the expression of GSDMD. In addition, EV-miRNA-22 showed higher pyroptosis-inhibiting ability than EV. Consequently, EV-miRNA-22 could inhibit the nerve function injury after SCI in rats, inhibit the level of inflammatory factors in the tissue and the activation of microglia. In this study, we found that miRNA-22-loaded MSCs-EV (EV-miRNA-22) could cooperate with EV to inhibit inflammatory response and nerve function repair after SCI.     

Effects of 28Si Ions, 56Fe Ions,and Protons on the Induction of Murine Acute Myeloid Leukemia and Hepatocellular Carcinoma

Estimates of cancer risks posed to space-flight crews by exposure to high atomic number, high-energy (HZE) ions are subject to considerable uncertainty because epidemiological data do not exist for human populations exposed to similar radiation qualities. We assessed the carcinogenic effects of 300 MeV/n ²⁸Si or 600 MeV/n ⁵⁶Fe ions in a mouse model for radiation-induced acute myeloid leukemia and hepatocellular carcinoma. C3H/HeNCrl mice were irradiated with 0.1, 0.2, 0.4, or 1 Gy of 300 MeV/n ²⁸Si ions, 600 MeV/n ⁵⁶Fe ions or 1 or 2 Gy of protons simulating the 1972 solar particle event (1972SPE) at the NASA Space Radiation Laboratory. Additional mice were irradiated with ¹³⁷Cs gamma rays at doses of 1, 2, or 3 Gy. All groups were followed until they were moribund or reached 800 days of age. We found that ²⁸Si or ⁵⁶Fe ions do not appear to be substantially more effective than gamma rays for the induction of acute myeloid leukemia. However, ²⁸Si or ⁵⁶Fe ion irradiated mice had a much higher incidence of hepatocellular carcinoma than gamma ray irradiated or proton irradiated mice. These data demonstrate a clear difference in the effects of these HZE ions on the induction of leukemia compared to solid tumors, suggesting potentially different mechanisms of tumorigenesis. Also seen in this study was an increase in metastatic hepatocellular carcinoma in the ²⁸Si and ⁵⁶Fe ion irradiated mice compared with those exposed to gamma rays or 1972SPE protons, a finding with important implications for setting radiation exposure limits for space-flight crew members.     

Mesenchymal stem cell expression of interleukin-35 protects against ulcerative colitis by suppressing mucosal immune responses

Background

Interleukin-35 (IL-35) has recently been identified as an immunosuppressive cytokine that has been used as a potential therapy for chronic inflammatory and autoimmune diseases. However, there remains a paucity of data regarding its potential benefits after integration into mesenchymal stem cells (MSCs).

Normal Thoracic Radiographic Appearance of the Cynomolgus Monkey (Macaca fascicularis)

Background

The cynomolgus monkey (Macaca fascicularis) has been increasingly used as a non-human primate model in biomedical research. As establishing baseline thoracic radiography for the cynomolgus monkey is essential, we tested the hypothesis that age and sex may affect the thoracic radiography parameters of this species.

Methods

Here, 697 healthy cynomolgus monkeys were segregated by sex and age (three age groups: 25–36 months, 37–48 months, 49–60 months). The lung length (LL), maximal interior thoracic depth (TD), maximal interior thoracic breadth (TBr), cardiac silhouette breadth (CBr), cardiothoracic ratio (CR), right and left costophrenic angles (RCA and LCA), and right hilar height ratio (R-HHR) were assessed by chest film. Statistical analysis was applied to examine the effect of age, sex, and age × sex interactions.

Results

Significant effects by age were shown for LL, TD, TBr, CBr, and CR. Significant effects by sex were found for TD, TBr, CBr, CR, and R-HHR. Significant effects by age × sex were observed for TD, TBr, CBr, and CR. Both TD and TBr increased with age in both sexes, and both were significantly higher in males than in females in the group aged 49–60 months. CBr increased with age and was significantly higher in males than in females across all age groups. CR declined with age and was significantly higher in males than females across all age groups, and CR was similar or slightly higher relative to those previously found in other non-human primate species. As to the other parameters with no significant sex nor age-related differences, the R-HHR was greater than 1.00, and the angulation of bilateral costophrenic angles were sharp.

Conclusions

The thoracic radiographic parameters for the healthy cynomolgus monkey presented here should prove useful in veterinary practice, research involving non-human primate models of respiratory or cardiovascular disorders, and morphological studies on cynomolgus monkeys.     

氧化低密度脂蛋白通过Wnt5a/PKCδ信号通路诱导大鼠肝星状细胞自噬

该文旨在研究氧化低密度脂蛋白(ox-LDL)对大鼠肝星状细胞(HSC-T6)自噬的影响及机制,探讨非酒精性脂肪肝炎的发病机理.体外培养的HSC-T6细胞以不同质量浓度(0、10、20、40、60μg/mL)的ox-LDL分别处理不同时间(0、3、6、12、24 h)后,用 Western blot检测LC3 Ⅱ、Be-...     

New mechanism of nerve injury in Alzheimer’s disease: β‐amyloid‐induced neuronal pyroptosis

The present study was designed to investigate the role of β‐amyloid (Aβ_1‐42) in inducing neuronal pyroptosis and its mechanism. Mice cortical neurons (MCNs) were used in this study, LPS + Nigericin was used to induce pyroptosis in MCNs (positive control group), and Aβ_1‐42 was used to interfere with MCNs. In addition, propidium iodide (PI) staining was used to examine cell permeability, lactate dehydrogenase (LDH) release assay was employed to detect cytotoxicity, immunofluorescence (IF) staining was used to investigate the expression level of the key protein GSDMD, Western blot was performed to detect the expression levels of key proteins, and enzyme‐linked immunosorbent assay (ELISA) was utilized to determine the expression levels of inflammatory factors in culture medium, including IL‐1β, IL‐18 and TNF‐α. Small interfering RNA (siRNA) was used to silence the mRNA expression of caspase‐1 and GSDMD, and Aβ_1‐42 was used to induce pyroptosis, followed by investigation of the role of caspase‐1‐mediated GSDMD cleavage in pyroptosis. In addition, necrosulfonamide (NSA), an inhibitor of GSDMD oligomerization, was used for pre‐treatment, and Aβ_1‐42 was subsequently used to observe the pyroptosis in MCNs. Finally, AAV9‐siRNA‐caspase‐1 was injected into the tail vein of APP/PS1 double transgenic mice (Alzheimer's disease mice) for caspase‐1 mRNA inhibition, followed by observation of behavioural changes in mice and measurement of the expression of inflammatory factors and pyroptosis‐related protein. As results, Aβ_1‐42 could induce pyroptosis in MCNs, increase cell permeability and enhance LDH release, which were similar to the LPS + Nigericin‐induced pyroptosis. Meanwhile, the expression levels of cellular GSDMD and p30‐GSDMD were up‐regulated, the levels of NLRP3 inflammasome and GSDMD‐cleaved protein caspase‐1 were up‐regulated, and the levels of inflammatory factors in the medium were also up‐regulated. siRNA intervention in caspase‐1 or GSDMD inhibited Aβ_1‐42‐induced pyroptosis, and NSA pre‐treatment also caused the similar inhibitory effects. The behavioural ability of Alzheimer's disease (AD) mice was relieved after the injection of AAV9‐siRNA‐caspase‐1, and the expression of pyroptosis‐related protein in the cortex and hippocampus was down‐regulated. In conclusion, Aβ_1‐42 could induce pyroptosis by GSDMD protein, and NLRP3‐caspase‐1 signalling was an important signal to mediate GSDMD cleavage, which plays an important role in Aβ_1‐42‐induced pyroptosis in neurons. Therefore, GSDMD is expected to be a novel therapeutic target for AD.     

甘蔗联合固氮的研究进展及应用潜力

在农业生产中,化学氮肥的投入大幅度增加了粮食产量,然而过量或不合理的施肥措施对农业生态环境造成了严重破坏.因此,挖掘植物自身的生物学特性,寻求其他有效的氮素来源,对农业减肥增效至关重要.其中,植物与微生物之间的生物固氮作用,能为宿主提供大量的清洁氮源,在农业生产中发挥着不可替代的作用.本文以甘蔗为代表,综述了植物联合固...     

Evaluation of Epstein-Barr Virus Salivary Shedding in HIV/AIDS Patients and HAART Use: A Retrospective Cohort Study

Little data is available on the evaluation of the occurrence rates of Epstein-Barr virus(EBV) in saliva and relationship with highly active antiretroviral therapy(HAART) use in HIV/AIDS patients in China. We conducted a retrospective cohort study of EBV serological tests for HIV/AIDS patients who were treated in the hospitals for infectious diseases in Wuxi and Shanghai, China from May 2016 to April 2017. The EBV-seropositive samples were identified by ELISA. EBV-specific primers and probes were used for the quantitative detection of viral DNA from saliva via quantitative real-time polymerase chain reaction. CD4 cell counts of the HIV/AIDS patients were detected by a flow cytometry. A total of 372 HIV/AIDS patients were ultimately selected and categorized for this retrospective cohort study. For EBV IgG and IgM, the HIV/AIDS HAART use(H) and non-HAART use(NH) groups had significantly higher seropositive rates than the HIV-negative control group. The HIV/AIDS(NH) group had the highest seropositive rate(IgG, 94.27%; IgM, 68.98%) and the highest incidence of EBV reactivation or infection. For salivary EBV DNA-positive rates and quantities, the HIV/AIDS(H)(73.69%) and the HIV/AIDS(NH)(100%) groups showed significantly higher values than the HIV-negative control group(35.79%,[ twofold). Further, the salivary EBV DNA-negative population had significantly higher CD4 cell counts than the EBV DNA-positive population in the HIV/AIDS(H) group and the HIV/AIDS(NH) groups. Thus, HAART use is beneficial in decreasing the EBV salivary shedding in HIV/AIDS patients and indirectly decreases EBV transmission risk.