Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.     

When aspiration fails: A study of its effect on mental disorder and suicide risk

Background

The Strain Theory of Suicide postulates that psychological strains usually precede suicide mental disorders including suicidal behavior. The four sources of strain are basically (1) differential value conflicts, (2) discrepancies between aspiration and reality, (3) relative deprivation, and (4) lack of coping skills. This paper focuses on the effect of perceived failed life aspiration on the individual's mental disorder and suicide risk.

Method

Data for this study were from a large psychological autopsy study conducted in rural China, where 392 suicides and 416 community living controls were consecutively recruited. Two informants (a family member and a close friend) were interviewed for each suicide and each control. Major depression was assessed with HAM-D and the diagnosis of mental disorder was made with SCID.

Results

It was found that individuals having experienced failed aspiration were significantly more likely than those having not experienced a failed aspiration to be diagnosed with at least one disorder measured by the SCID and major depression measured by HAM-D, and to be a suicide victim, which is true of both suicides and controls.

Conclusion

This study supports the hypothesis that the discrepancies between an individual's aspiration and the reality is likely to lead to mental disorder including major depression and suicidal behavior. Lowering a patient's unrealistic aspiration can be part of the of psychological strains reduction strategies in cognitive therapies by clinicians' and mental health professionals.     

TNF-α-Secreting B Cells Contribute to Myocardial Fibrosis in Dilated Cardiomyopathy

Purpose

Excessive inflammation responses mediated by CD4⁺ T cells contributes to myocardial fibrosis in dilated cardiomyopathy (DCM) resulting from viral myocarditis. Recently, some scholars discovered that B cells harbored an abnormal pro-inflammatory capacity besides the production of autoantibodies. Thus, we aimed to explore whether and which type of B cells act on myocardial fibrosis in DCM.

Methods

A total of 56 newly hospitalized DCM patients were studied, and among these, 17 patients accepted the gadolinium enhanced cardiovascular magnetic resonance imaging (MRI) for myocardial fibrosis evaluations.

Results

B cell functions including the frequency and proliferation were significantly elevated in DCM patients. After screening the important cytokines including IL-1β, IL-6, IL-10, IL-17, TNF-α and TGF-β produced in these B cells by flow cytometry, we found that only the TNF-α-secreting B cells were obviously increased. Furthermore, the TNF-α protein secretion and mRNA levels were also enhanced in LPS-stimulated B cell isolated from DCM patients. In addition, 10 patients (59 %) with increased TNF-α-secreting B cells showed late enhancement and boosted serum procollagen type III compared with the other 7 patients (41 %) whose enhancement could not be detected. Moreover, the frequencies of TNF-α-secreting B cells were negatively correlated with LVEF and positively correlated with LVEDD, NT-proBNP and procollagen type III in all of the DCM patients.

Conclusions

Our study firstly suggested that TNF-α-secreting B cells were involved in myocardial fibrosis, which revealed the new pathogenic mechanism of B cells in DCM, and therapeutic targets against these cells might be valuable.     

Knockdown of NRAGE induces odontogenic differentiation by activating NF-κB signaling in mouse odontoblast-like cells

Purpose: Neurotrophin receptor-interacting MAGE homologue (Nrage) plays an important role in bone development and the metabolism of normal skeletal structures. Our previous study showed that Nrage inhibited the odontogenic differentiation of mouse dental pulp cells. However, the potential roles and mechanism of Nrage in regulating odontogenic differentiation are unknown. The aim of this study was to investigate the molecular mechanism of Nrage in odontogenic differentiation of mouse odontoblast-like cells.

Materials and methods: Endogenous expression of Nrage was stably downregulated by lentivirus-mediated shRNA. Mineralized nodules formation was detected by alizarin red S staining. Dmp-1, Dspp, and ALP mRNA and protein levels were detected by qRT-PCR and western blotting, respectively. In addition, ALPase activity was detected. Confocal microscopy and co-immunoprecipitation (co-IP) were used to analyze the interactions between NRAGE and NF-κB signaling molecules. An IKK inhibitor was also used in the study.

Results: NRAGE expression in odontoblasts was downregulated during mouse first maxillary molar development. Moreover, NRAGE expression was downregulated during odontogenic differentiation of odontoblast-like cells. NRAGE knockdown significantly upregulated DMP1 and DSP expression, increased ALPase activity, and promoted mineralized nodule formation. In addition, NRAGE knockdown increased the translocation of NF-κB1 to the nucleus and phosphorylation levels of p65. Co-IP results showed that NRAGE bound to IKKβ. Most importantly, the promoting effect of Nrage knockdown on odontoblastic differentiation was reduced after treatment with an IKK inhibitor.

Conclusions: Our data confirmed that NRAGE is an important regulator of odontogenic differentiation of odontoblasts by inhibiting the NF-κB signaling pathway through binding to IKKβ.

Abbreviations: Nrage: neurotrophin receptor-interacting MAGE homologue; DSP: dentin sialophospho protein; DMP-1: dentin matrix protein-1; BMP: bone morphogenetic protein; Wnt: wingless; NF-κB: nuclear factor of activated B cells; DAPI: 4′,6-diamidino-2-phenylindole; KO: knockout; DPCs: dental pulp cells; AA: ascorbic acid; β-Gly: β-glycerophosphate; Dex: dexamethasone; co-IP: co-immunoprecipitation; IκB: inhibitor of NF-κB; IKK: IκB kinase     

微波消融联合载阿霉素微泡靶向击破在小鼠H22肝癌治疗中的效果观察

【摘要】 目的 观察微波消融（MWA）联合载阿霉素微泡靶向击破治疗小鼠H22肝癌皮下瘤的效果。 方法 制备空白微泡和载阿霉素微泡,检测其理化特性。流式细胞仪分析不同给药方式下体外细胞内药物浓度。构建BALB/c小鼠H22肝癌皮下瘤模型,将72只荷瘤小鼠随机均分为单纯MWA组（A组）、MWA+阿霉素组（B组）、MWA+空白微泡组（C组）、MWA+载阿霉素微泡组（D组）,其中C、D组微泡经低频超声击破。记录小鼠肿瘤体积变化,构建Kaplan-Meier生存曲线,比较心、肾组织内药物浓度。病理切片检测各组残存活性肿瘤区微血管密度（MVD）和Ki-67表达,并进行统计学分析。结果 体外细胞实验显示,低频超声靶向击破微泡技术能显著提高肿瘤细胞内药物浓度（P=0.011）;体内实验显示,D组抑制肿瘤生长显著优于A组（P=0.008 5）,B组、D组小鼠生存时间均比A组显著延长（P=0.009,P=0.003）,同时D组心、肾组织内药物浓度均显著降低（P=0.012,P=0.045）。D组残存活性肿瘤区MVD与A组相比显著降低（P＜0.000 1）,B、D组肿瘤细胞Ki-67表达均显著降低（P＜0.001）。结论 MWA联合载阿霉素微泡超声靶向击破可提高肝癌细胞内药物浓度,抑制肿瘤增殖和微血管生成,弥补单纯MWA治疗适形性不足,同时降低药物心、肾不良反应。     

Molecular variability of sweet potato chlorotic stunt virus (SPCSV) and five potyviruses infecting sweet potato in China

To obtain a better understanding of the molecular variation of sweet potato viruses in China, 131 samples were collected from symptomatic sweet potato plants and used for RT-PCR analysis of the heat shock protein 70 (hsp70) gene sequence of sweet potato chlorotic stunt virus (SPCSV) and the coat protein (CP) gene sequences of five potyviruses (SPFMV, SPVC, SPVG, SPLV and SPV2). The hsp70 sequences that were obtained provided evidence for the presence of two distinct strains of SPCSV. Analysis of the CP sequences amplified from the samples indicated that all five potyviruses infect sweet potato in China, and three different strains of SPFMV and two of SPVG were found.     

Religious service attendance typologies and African American substance use: a longitudinal study of the protective effects among young adult men and women

Purpose

This study sought to identify variation by gender in the associations between religious service attendance from adolescence to young adulthood and seven measures of lifetime and short-term substance use.

Methods

To conduct this nationally representative study, data from the Add Health Surveys was abstracted from Waves I and IV (N = 3,223) to construct four types of service attendance (non-attenders, attenders only as adolescents, attenders only in young adulthood, and consistent attenders). A series of logistic regressions were conducted to identify the independent effects of each pattern of service attendance on each substance among all black young adults, as well as male and female sub-samples.

Results

Analysis revealed consistent attenders were generally less likely to use substances, with the effects being strongest among females. Among young adult only attenders, males recorded lower odds across all three short-term measures whereas females reported lower odds only for monthly cigarette use.

Conclusion

The protective effects of religious service attendance are more robust for African Americans who consistently attend in adolescence and young adulthood, especially among females.