Hyperphosphorylated Tau Inflicts Intracellular Stress Responses that Are Mitigated by Apomorphine

Abnormal phosphorylation of the microtubule-binding protein tau in the brain is a key pathological marker for Alzheimer's disease and additional neurodegenerative tauopathies. However, how hyperphosphorylated tau causes cellular dysfunction or death that underlies neurodegeneration remains an unsolved question critical for the understanding of disease mechanism and the design of efficacious drugs. Using a recombinant hyperphosphorylated tau protein (p-tau) synthesized by the PIMAX approach, we examined how cells responded to the cytotoxic tau and explored means to enhance cellular resistance to tau attack. Upon p-tau uptake, the intracellular calcium levels rose promptly. Gene expression analyses revealed that p-tau potently triggered endoplasmic reticulum (ER) stress, unfolded protein response (UPR), ER stress-associated apoptosis, and pro-inflammation in cells. Proteomics studies showed that p-tau diminished heme oxygenase-1 (HO-1), an ER stress-associated anti-inflammation and anti-oxidative stress regulator, while stimulated the accumulation of MIOS and other proteins. p-Tau-induced ER stress-associated apoptosis and pro-inflammation are ameliorated by apomorphine, a brain-permeable prescription drug widely used to treat Parkinson's disease symptoms, and by overexpression of HO-1. Our results reveal probable cellular functions targeted by hyperphosphorylated tau. Some of these dysfunctions and stress responses have been linked to neurodegeneration in Alzheimer's disease. The observations that the ill effects of p-tau can be mitigated by a small compound and by overexpressing HO-1 that is otherwise diminished in the treated cells inform new directions of Alzheimer's disease drug discovery.

Receptor transfer between immune cells by autoantibody-enhanced, CD32-driven trogocytosis is hijacked by HIV-1 to infect resting CD4 T cells

Immune cell phenotyping frequently detects lineage-unrelated receptors. Here, we report that surface receptors can be transferred from primary macrophages to CD4 T cells and identify the Fcγ receptor CD32 as driver and cargo of this trogocytotic transfer. Filamentous CD32+ nanoprotrusions deposit distinct plasma membrane patches onto target T cells. Transferred receptors confer cell migration and adhesion properties, and macrophage-derived membrane patches render resting CD4 T cells susceptible to infection by serving as hotspots for HIV-1 binding. Antibodies that recognize T cell epitopes enhance CD32-mediated trogocytosis. Such autoreactive anti-HIV-1 envelope antibodies can be found in the blood of HIV-1 patients and, consistently, the percentage of CD32+ CD4 T cells is increased in their blood. This CD32-mediated, antigen-independent cell communication mode transiently expands the receptor repertoire and functionality of immune cells. HIV-1 hijacks this mechanism by triggering the generation of trogocytosis-promoting autoantibodies to gain access to immune cells critical to its persistence.

[A control study of steroid withdrawal protection strategy after kidney transplantation in children]

Objective: To study the influence of steroid withdrawal protection strategy on height growth in pediatric patients after kidney transplantation. Methods: The prospective cohort study enrolled 40 stage 5 chronic kidney disease children receiving kidney transplantation from July 2017 to September 2022 at Guangzhou Women and Children's Medical Center. Based on the primary preoperative disease, patients with immune abnormality-associated glomerular diseases or unknown causes were assigned to the steroid maintenance group, in which patients received steroid tapering within 3 months after surgery to a maintenance dose of 2.5 to 5.0 mg/d. While patients with hereditary kidney disease or congenital urinary malformations were assigned to the steroid withdrawal group, in which patients had steroids tapered off within 3 months. The characteristics of height catch-up growth and clinical data were compared between the 2 groups at baseline, 6, 12, 18 and 24 months after kidney transplantation. T-test, repeated measurement of variance analysis, Mann-Whitney U test, and Fisher exact test were used for the comparison between the 2 groups. Results: Among the 40 children, 17 were males, 23 were females, 25 were in the steroid withdraw group ((7.8±2.8) years old when receiving kidney transplantation) and 15 cases were in the steroid maintenance group ((7.6±3.5) years old when receiving kidney transplantation). The study population was followed up for (26±12) months. The total dose per unit body weight of steroids in the steroid withdrawal group was lower than that in the steroid maintenance group ((0.13±0.06) vs. (0.36±0.19) mg/(kg·d), t=5.83, P<0.001). The height catch-up rate (ΔHtSDS) in the first year after kidney transplantation in the steroid withdraw and steroid maintenance groups was 1.0 (0.7, 1.4) and 0.4 (0.1, 1.0), respectively; in the second year, the ΔHtSDS in the steroid withdraw group was significantly higher than that in the steroid maintenance group (1.1 (0.2, 1.7) vs. 0.3 (0, 0.8), U=28.00, P=0.039). The HtSDS in the steroid withdrawal group at the five follow-up time points was -2.5±0.8, -2.0±0.8, -1.5±0.8, -1.3±0.9 and -0.5±0.3, respectively, while in the steroid maintenance was -2.4±1.3, -2.2±1.1, -2.0±1.0, -1.8±1.0 and -1.6±1.0, respectively. There were statistically significant differences in HtSDS at different follow-up time points in both 2 groups (F=19.81, P<0.01), but no statistical differences in overall impact between the 2 groups (F=1.13, P=0.204). The steroid treatment was interaction with the increase of follow-up time (F=3.62, P=0.009). At the 24th month after transplantation, the HtSDS in the steroid withdrawal group was significantly higher than that in the steroid maintenance group (P=0.047). Six patients in the steroid withdrawal group experienced antibody-mediated immune rejection (AMR), while 3 did in the steroid maintenance group. Moreover, there was no significant difference in AMR between the two groups (χ2=0.06, P=0.814). Conclusion: The steroid withdrawal protection strategy favors the height catch-up growth in pediatric patients after kidney transplantation and does not increase the risk of postoperative antibody-mediated immune rejection.

[Characteristics of Guyton's exaggerated forced duction test (FDT) and torsional FDT in congenital superior oblique palsy]

Objective: To investigate the characteristics of Guyton's exaggerated forced duction test (FDT) and torsional FDT in patients with congenital superior oblique palsy (CSOP) and their correlation with clinical features. Methods: This cross-sectional study included single-eye CSOP patients and intermittent exotropia (IXT) patients scheduled for strabismus correction surgery at Tianjin Eye Hospital from September 2021 to March 2022. Prior to surgery, measurements of fovea-disc angle (FDA) and maximum cross-sectional area of the superior oblique muscle (max-CSA) were obtained in both eyes of the patients. The Guyton's exaggerated FDT and torsional FDT were performed intraoperatively to assess the degree of superior oblique muscle relaxation. The characteristics of the two FDT tests and their correlation with vertical strabismus angle, FDA, and max-CSA were analyzed. Statistical analyses were conducted using t-test, ANOVA, Tukey's test, Mann-Whitney U test, and chi-square test. Results: A total of 42 patients (84 eyes) were included in the study, including 19 IXT patients (38 eyes) and 23 CSOP patients (46 eyes, 23 eyes with palsy and 23 eyes without palsy). There were no statistically significant differences in gender composition or age between the IXT and CSOP patients (all P>0.05). The degrees of superior oblique muscle relaxation measured by the Guyton's exaggerated FDT were (-2.52±1.20), (-0.35±0.71), and (-0.03±0.16) for the palsy eye, non-palsy eye, and IXT eyes, respectively, showing significant differences (F=88.10, P<0.001). The torsional FDT measurements yielded external rotation angles of 48.70°±9.67°, 37.39°±5.40°, and 38.95°±2.88° for the palsy eye, non-palsy eye, and IXT eyes, respectively, showing significant differences (F=16.67, P<0.001). There was no statistically significant difference in internal rotation angles (F=2.36, P=0.100). The FDA values were-12.11°±7.42° for IXT patients and-19.02°±4.95° for CSOP patients, while the max-CSA values for the palsy eye and non-palsy eye of CSOP patients were (7.59±4.69) mm² and (11.63±3.64) mm², respectively, all showing significant differences (all P<0.001). The degree of superior oblique muscle tendon relaxation assessed by the Guyton's exaggerated FDT was negatively correlated with the external rotation angle measured by the torsional FDT (r=-0.64, P=0.001). They were positively correlated with max-CSA (r=0.45, P=0.030) and negatively correlated with max-CSA (r=-0.52, P=0.011). However, there was no correlation with vertical and rotational strabismus angle (r=-0.12, P=0.579; r=0.33, P=0.126) and FDA (r=-0.02, P=0.921; r=-0.23, P=0.309). Conclusions: Guyton's exaggerated FDT and torsional FDT can both assess the degree of superior oblique muscle relaxation in patients with CSOP. Furthermore, these two tests are correlated with changes in superior oblique muscle morphology. However, FDT cannot reflect the degree of vertical and rotational strabismus in patients.

Hyperphosphorylated tau Inflicts Intracellular Stress Responses That Are Mitigated by Apomorphine

Background

Abnormal phosphorylation of the microtubule-binding protein tau in the brain is a key pathological marker for Alzheimer's disease and additional neurodegenerative tauopathies. However, how hyperphosphorylated tau causes cellular dysfunction or death that underlie neurodegeneration remains an unsolved question critical for the understanding of disease mechanism and the design of efficacious drugs.

Methods

Using a recombinant hyperphosphorylated tau protein (p-tau) synthesized by the PIMAX approach, we examined how cells responded to the cytotoxic tau and explored means to enhance cellular resistance to tau attack.

Results

Upon p-tau uptake, the intracellular calcium levels rose promptly. Gene expression analyses revealed that p-tau potently triggered endoplasmic reticulum (ER) stress, Unfolded Protein Response (UPR), ER stress-associated apoptosis, and pro-inflammation in cells. Proteomics studies showed that p-tau diminished heme oxygenase-1 (HO-1), an ER stress associated anti-inflammation and anti-oxidative stress regulator, while stimulated the accumulation of MIOS and other proteins. P-tau-induced ER stress-associated apoptosis and pro-inflammation are ameliorated by apomorphine, a brain-permeable prescription drug widely used to treat Parkinson's disease symptoms, and by overexpression of HO-1.

Conclusion

Our results reveal probable cellular functions targeted by hyperphosphorylated tau. Some of these dysfunctions and stress responses have been linked to neurodegeneration in Alzheimer's disease. The observations that the ill effects of p-tau can be mitigated by a small compound and by overexpressing HO-1 that is otherwise diminished in the treated cells inform new directions of Alzheimer's disease drug discovery.

Application of Cotton Swab-Ag Composite as Flexible Surface-Enhanced Raman Scattering Substrate for DMMP Detection

It is both important and required to quickly and accurately detect chemical warfare agents, such as the highly toxic nerve agent sarin. Surface-enhanced Raman scattering (SERS) has received considerable attention due to its rapid results, high sensitivity, non-destructive data acquisition, and unique spectroscopic fingerprint. In this work, we successfully prepared SERS cotton swabs (CSs) for the detection of the sarin simulant agent dimethyl methyl phosphonate (DMMP) by anchoring N1-(3-trimethoxysilylpropyl) diethylenetriamine (ATS)/silver nanoparticle (AgNP) nanocomposites on CSs using ATS as the stabilizer and coupling agent. Simultaneously, the binding mode and reaction mechanics between the AgNP, ATS, and CS were confirmed by XPS. The modified CSs exhibited good uniformity, stability, and adsorption capability for SERS measurements, enabling the adsorption and detection of DMMP residue from an irregular surface via a simple swabbing process, with a detection limit of 1 g/L. The relative standard deviations (RSDs) of RSD₇₁₀ = 5.6% had high reproducibility. In this research, the fabrication method could easily be extended to other cellulose compounds, such as natural fibers and paper. Furthermore, the versatile SERS CSs can be used for the on-site detection of DMMP, particularly in civil and defense applications, to guarantee food security and the health of the population.

The gut-brain axis: Effect of electroacupuncture pretreatment on learning, memory, and JNK signaling in D-galactose-induced AD-like rats

Objectives

To examine the effect and potential mechanism of electroacupuncture (EA) pretreatment in spatial learning, memory, gut microbiota, and JNK signaling in D-galactose-induced AD-like rats.

Materials and Methods

The AD-like rat model was generated by intraperitoneal injection of D-galactose. Morris water maze was used to determine spatial learning and memory ability, Real-time PCR to determine intestinal flora levels, ELISA to determine tryptophan (Trp) and 5-HT levels in the colon and hippocampal tissues, immunofluorescence to determine 5-HT levels in enterochromaffin cells (ECs), and immunoblotting to determine JNK signaling protein levels in hippocampal tissues.

Results

Electroacupuncture pretreatment significantly reduced escape latency and prolonged exploration time in the target quadrant, and significantly increased the relative DNA abundance of Lactobacillus and Bifidobacterium. Meanwhile, electroacupuncture pretreatment also reduced colonic 5-HT levels and increased hippocampal 5-HT levels. Moreover, electroacupuncture pretreatment significantly inhibited hippocampal JNK pathway-related protein expression, including 5-HT6R, JNK, p-JUNK, c-JUN, and p-c-Jun. And the combination of GV20 and ST36 was more effective than single acupoints.

Conclusion

Electroacupuncture pretreatment improved the learning and memory ability of D-galactose-induced AD-like model rats, changed the gut microbiota composition, and the mechanism may be related to the gut-brain axis and the JNK signaling pathway. In addition, the combination of GV20 and ST36 could further enhance the efficacy.

CXCR4 and CD74 together enhance cell survival in response to macrophage migration-inhibitory factor in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of small, mature CD5⁺ B lymphocytes in the blood, marrow, and lymphoid organs. Cell survival depends on interaction with the leukemic microenvironment. However, the mechanisms controlling CLL cell survival are still incompletely understood. Macrophage migration-inhibitory factor (MIF), a pro-inflammatory and immunoregulatory chemokine-like cytokine, interacts with CXCR4, a major chemokine receptor, as well as with CD74/invariant chain, a single-pass type II receptor. In this study, we analyzed the roles of CXCR4, CD74, and MIF in CLL. Mononuclear cells from patients with hematological malignancies were analyzed for coexpression of CXCR4 and CD74 by flow cytometry. Strong co- and overexpression of CXCR4 and CD74 were observed on B cells of CLL patients (n = 10). Survival and chemotaxis assays indicated that CXCR4 and CD74 work together to enhance the survival and migration of malignant cells in CLL. Blockade of the receptors, either individually or in combination, promoted cell death and led to an abrogation of MIF-driven migration responses in murine and human CLL cells, suggesting that joint activation of both receptors is crucial for CLL cell survival and mobility. These findings indicate that the MIF/CXCR4/CD74 axis represents a novel therapeutic target in CLL.

Stroke propensity in the Th3+/ mouse model of β-thalassemia intermedia

β-thalassemia is associated with multiple hematological and cerebrovascular symptoms linked to a hypercoagulable state that has not been fully replicated in animal models for the development of stroke treatments. Herein we compared the physiological properties and responses to transient cerebral hypoxia-ischemia (tHI) between six-month-old wildtype and heterozygous Th3/+ mice, a model of non-transfusion-dependent β-thalassemia intermedia (β-TI). We found that Th3/+ mice developed microcytic anemia, splenomegaly, higher platelet counts, and increased platelet-erythrocyte plus erythrocyte-leukocyte aggregates. Furthermore, Th3/+ mice showed diminished cerebrovascular reactivity (CVR) and cortical oxygen saturation under repetitive hypercapnic challenges. When subjected to a sub-threshold tHI insult, platelets and leukocytes in Th3/+ mice adhered to the cerebrovascular wall or formed aggregates, while their counterparts flew through smoothly in wildtype mice. Subsequently, Th3/+ mice showed increased fibrin deposition around cerebral blood vessels and larger infarction than wildtype mice, especially in female Th3/+ mice. Collectively these results showed that Th3/+ mice mimic key clinical features and a propensity to thromboembolism in β-TI patients. The hypercoagulable state in Th3/+ mice is likely caused by multiple hematological and CVR anomalies that are similar, but are not identical to those in the mouse model of sickle cell anemia. As such, we suggest that Th3/+ mice are a useful model to study the pathological mechanisms and prophylactic stroke treatments in thalassemia patients.

A cascade reaction for regioselective construction of pyrazole-containing aliphatic sulfonyl fluorides

A copper-catalyzed cascade reaction of α-diazocarbonyl compounds with ethenesulfonyl fluoride (ESF) is developed, affording a variety of highly functionalized pyrazolyl aliphatic sulfonyl fluorides in good to excellent yields (66-98%). This transformation features broad substrates, exclusive regioselectivity, high atom economy and operational simplicity, thus providing a straightforward method for the direct construction of pyrazole-containing aliphatic sulfonyl fluorides, which will provide great applicable value in medicinal chemistry and other related disciplines.

Monocytes promote acute neuroinflammation and become pathological microglia in neonatal hypoxic-ischemic brain injury

Rationale: Monocytes belong to the mononuclear phagocyte system and are immune responders to tissue injury and infection. There were also reports of monocytes transforming to microglia-like cells. Here we explore the roles of monocytes in microglia ontogeny and the pathogenesis of neonatal cerebral hypoxic-ischemic (HI) brain injury in mice. Methods: We used three genetic methods to track the development of monocytes, including CX3CR1GFP/+; CCR2RFP/+ reporter mice, adoptive transfer of GFP+ monocytes, and fate-mapping with CCR2-CreER mice, in neonatal mouse brains with or without lipopolysaccharide (LPS, 0.3 mg/kg)-sensitized Vannucci HI. We also used genetic (CCR2RFP/ RFP, CCR2 knockout) and pharmacological methods (RS102895, a CCR2 antagonist) to test the roles of monocytic influx in LPS/HI brain injury. Results: CCR2+ monocytes entered the late-embryonic brains via choroid plexus, but rapidly became CX3CR1+ amoeboid microglial cells (AMCs). The influx of CCR2+ monocytes declined after birth, but recurred after HI or LPS-sensitized HI (LPS/HI) brain injury, particularly in the hippocampus. The CCR2-CreER-based fate-mapping showed that CCR2+ monocytes became CD68+ TNFα+ macrophages within 4 d after LPS/HI, and maintained as TNFα+ MHCII+ macrophages or persisted as Tmem119+ Sall1+ P2RY12+ ramified microglia for at least five months after injury. Genetic deletion of the chemokine receptor CCR2 markedly diminished monocytic influx, the expression of pro- and anti-inflammatory cytokines, and brain damage. Post-LPS/HI application of RS102895 also reduced inflammatory responses and brain damage, leading to better cognitive functions. Conclusion: These results suggest that monocytes promote acute inflammatory responses and may become pathological microglia long after the neonatal LPS/HI insult. Further, blocking the influx of monocytes may be a potential therapy for neonatal brain injury.

Sleep disturbance and quality of life among university freshmen in Qinghai-Tibet Plateau of China

PURPOSE

University freshmen are particularly vulnerable as they are undergoing the transition from high school to university with a range of changes. Sleep problems among this group in the Qinghai-Tibet Plateau of China were barely studied. This study aimed to explore sleep disturbance, and its association with quality of life (QoL) and demographic and clinical characteristics among university freshmen in Qinghai-Tibet Plateau, China.

METHODS

A multistage stratified cluster random sampling method was performed to recruit student participants with a structured questionnaire to collect sociodemographic and clinical characteristics, and lifestyle behaviors. Sleep disturbance including three aspects of sleep disturbance (i.e., difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and early morning awakening (EMA)) was assessed using standardized measurement. Multiple logistic regression models were applied to analyze the data.

RESULTS

Among included 2,769 freshmen, the prevalence of sleep disturbance was 14.8% (95% CI: 14.2-15.5%), and corresponding prevalence of DIS, DMS, and EMA was 8.2% (95% CI: 7.7-8.7%), 8.3% (95% CI: 7.8-8.8%), and 4.2% (95% CI: 3.8-4.6%), respectively. Freshmen with sleeping disturbance had significantly lower QoL in physical [F _{(1, 2769)} = 60.23, p < 0.001], psychological [F _{(1, 2769)} = 46.18, p < 0.001], social [F _{(1, 2769)} = 23.04, p < 0.001], and environment [F _{(1, 2769)} = 6.07, p = 0.01] domains. Multiple logistic regression analyses revealed that having breakfast five times a week or less (less than three times, OR = 1.79, 95% CI: 1.34-2.40; 3-5 times, OR = 1.40, 95% CI: 1.09-1.79), self-perceived severe Internet dependence (OR = 1.71, 95% CI: 1.11-2.65), self-perceived poor health status (OR = 3.44, 95% CI: 2.06-5.74), high academic stress (OR = 1.42, 95% CI: 1.13-1.78), poor relationship with classmates (OR = 3.44, 95% CI: 1.53-7.71), and severe ADHD symptoms (OR = 1.08, 95% CI: 1.05-1.12) were positively associated with sleeping disturbance.

CONCLUSION

Sleep disturbance was common among freshmen and is associated with poorer QoL. Prevention and intervention strategies should be developed and implemented, especially among the vulnerable university freshman groups.

Creatine transporter deficiency impairs stress adaptation and brain energetics homeostasis

The creatine transporter (CrT) maintains brain creatine (Cr) levels, but the effects of its deficiency on energetics adaptation under stress remain unclear. There are also no effective treatments for CrT deficiency, the second most common cause of X-linked intellectual disabilities. Herein, we examined the consequences of CrT deficiency in brain energetics and stress-adaptation responses plus the effects of intranasal Cr supplementation. We found that CrT-deficient (CrT^–/y) mice harbored dendritic spine and synaptic dysgenesis. Nurtured newborn CrT^–/y mice maintained baseline brain ATP levels, with a trend toward signaling imbalance between the p-AMPK/autophagy and mTOR pathways. Starvation elevated the signaling imbalance and reduced brain ATP levels in P3 CrT^–/y mice. Similarly, CrT^–/y neurons and P10 CrT^–/y mice showed an imbalance between autophagy and mTOR signaling pathways and greater susceptibility to cerebral hypoxia-ischemia and ischemic insults. Notably, intranasal administration of Cr after cerebral ischemia increased the brain Cr/N-acetylaspartate ratio, partially averted the signaling imbalance, and reduced infarct size more potently than intraperitoneal Cr injection. These findings suggest important functions for CrT and Cr in preserving the homeostasis of brain energetics in stress conditions. Moreover, intranasal Cr supplementation may be an effective treatment for congenital CrT deficiency and acute brain injury.

Capillary-associated microglia regulate vascular structure and function through PANX1-P2RY12 coupling in mice

Microglia are brain-resident immune cells with a repertoire of functions in the brain. However, the extent of their interactions with the vasculature and potential regulation of vascular physiology has been insufficiently explored. Here, we document interactions between ramified CX3CR1 + myeloid cell somata and brain capillaries. We confirm that these cells are bona fide microglia by molecular, morphological and ultrastructural approaches. Then, we give a detailed spatio-temporal characterization of these capillary-associated microglia (CAMs) comparing them with parenchymal microglia (PCMs) in their morphological activities including during microglial depletion and repopulation. Molecularly, we identify P2RY12 receptors as a regulator of CAM interactions under the control of released purines from pannexin 1 (PANX1) channels. Furthermore, microglial elimination triggered capillary dilation, blood flow increase, and impaired vasodilation that were recapitulated in P2RY12-/- and PANX1-/- mice suggesting purines released through PANX1 channels play important roles in activating microglial P2RY12 receptors to regulate neurovascular structure and function.

Sex differences in the factors associated with sleep duration in university students: A cross-sectional study

BACKGROUND

Insufficient sleep duration among university students was commonly associated with many detrimental effects. University students experience substantial environmental and psychological changes. Female and male university students may differ in many spheres. However, most research on sleep duration of university students is based on an aggregate sample rather than digging the sex-specific profiles. The objective of this study is to examine potential sex differences in the correlates of sleep duration and explore the underlying mechanism of correlations.

METHODS

This is a large-scale university-based mental health survey, which was conducted in university students in Qinghai Province in Northwest China in December 2019. A multi-stage logistic regression was separately fitted by sex to examine the factors associated with short sleep duration in university students.

RESULTS

A total of 5,552 university students with an average sleep duration of 6.88 h (SD = 1.04) were included, among which 35.0% of the participants may currently be sleeping less than the optimal duration. Female students (6.84 h, SD = 1.00) slept shorter than males (6.94 h, SD = 1.09). The only parallel between sexes was that both female and male students with 3-5 times weekly breakfast were less likely to have short sleep duration. Adjusting for depressive symptoms in the following step eliminated the association between anxiety symptoms and short sleep duration in the model for female students. Female-specific associated factors with short sleep duration were age, grade, academic pressure, weekly physical exercise, depressive symptoms. Male-specific characteristics were current smoking tobacco cigarette, self-perceived health, duration of daily Internet use.

CONCLUSION

Characteristic profiles of sleep duration differed between female and male university students; only a few male-specific factors were identified. Psychological guidance and education courses as well as other interventions to improve university students' sleep and related health should be designed and implemented based on sex differences.

A novel three-component reaction for constructing indolizine-containing aliphatic sulfonyl fluorides

A copper-catalyzed three-component reaction for transforming quinolines, isoquinolines and pyridines to a class of indolizine-containing alkyl sulfonyl fluorides was developed.

[Effect of pretreatment of acupuncture on learning-memory ability and related protein of NLRP3 inflammasome in hippocampus in Alzheimer's disease like rats]

OBJECTIVE

To observe the effect of pretreatment of acupuncture on the expression of nucleotide-binding oligomerization domain-like receptor 3(NLRP3), Caspase-1, interleukin1β(IL-1β) and the number of activated microglia (MG) in the hippocampus in Alzheimer's disease (AD) like rats, so as to explore the mechanism of pretreatment of acupuncture in preventing and treating AD.

METHODS

A total of 36 SD rats were randomly divided into a blank group, a model group and an electroacupuncture (EA) group, 12 rats in each group. The AD like rat model was established by 8-week continuous intraperitoneal injection of D-galactose (120 mg·kg^-1·d^-1) in the model group and the EA group. The rats in the EA group were intervened with EA at "Baihui" (GV 20) and "Zusanli" (ST 36), continuous wave, 5 Hz in frequency, 1 mA in intensity, 20 min each intervention, once a day, for 8 weeks. After the intervention, the spatial learning-memory ability was evaluated by the Morris water maze test. The expression levels of NLRP3, Caspase-1 and IL-1β protein in hippocampus were detected by Western blot method. The number of activated MG in hippocampus was detected by immunofluorescence labeling method.

RESULTS

Compared with the blank group, the average escape latency was prolonged (P<0.01), the number of platform crossing was reduced (P<0.01), and the exploration time of target quadrant was shortened (P<0.01) in the model group. Compared with the model group, the average escape latency was shortened (P<0.01), the number of platform crossing was increased (P<0.01), and the exploration time of target quadrant was prolonged (P<0.01) in the EA group. Compared with the blank group, the expression levels of NLRP3, Caspase-1, IL-1β protein in hippocampus were increased (P<0.01), and the number of activated MG was increased (P<0.01) in the model group. Compared with the model group, the expression levels of NLRP3, Caspase-1, IL-1β protein in hippocampus were decreased (P<0.01), and the number of activated MG was decreased (P<0.05) in the EA group.

CONCLUSION

Pretreatment of acupuncture could prevent and treat the learning-memory dysfunction in AD like rats, and its mechanism may be related to the inhibition of NLRP3 inflammatsome related protein and MG activation.

Brain-targeted hypoxia-inducible factor stabilization reduces neonatal hypoxic-ischemic brain injury

Hypoxia-inducible factor-1α (HIF1α) is a major regulator of cellular adaptation to hypoxia and oxidative stress, and recent advances of prolyl-4-hydroxylase (P4H) inhibitors have produced powerful tools to stabilize HIF1α for clinical applications. However, whether HIF1α provokes or resists neonatal hypoxic-ischemic (HI) brain injury has not been established in previous studies. We hypothesize that systemic and brain-targeted HIF1α stabilization may have divergent effects. To test this notion, herein we compared the effects of GSK360A, a potent P4H inhibitor, in in-vitro oxygen-glucose deprivation (OGD) and in in-vivo neonatal HI via intracerebroventricular (ICV), intraperitoneal (IP), and intranasal (IN) drug-application routes. We found that GSK360A increased the erythropoietin (EPO), heme oxygenase-1 (HO1) and glucose transporter 1 (Glut1) transcripts, all HIF1α target-genes, and promoted the survival of neurons and oligodendrocytes after OGD. Neonatal HI insult stabilized HIF1α in the ipsilateral hemisphere for up to 24 h, and either ICV or IN delivery of GSK360A after HI increased the HIF1α target-gene transcripts and decreased brain damage. In contrast, IP-injection of GSK360A failed to reduce HI brain damage, but elevated the risk of mortality at high doses, which may relate to an increase of the kidney and plasma EPO, leukocytosis, and abundant vascular endothelial growth factor (VEGF) mRNAs in the brain. These results suggest that brain-targeted HIF1α-stabilization is a potential treatment of neonatal HI brain injury, while systemic P4H-inhibition may provoke unwanted adverse effects.

Fate mapping via CCR2-CreER mice reveals monocyte-to-microglia transition in development and neonatal stroke

Whether monocytes contribute to the brain microglial pool in development or after brain injury remains contentious. To address this issue, we generated CCR2-CreER mice to track monocyte derivatives in a tamoxifen-inducible manner. This method labeled Ly6Chi and Ly6Clo monocytes after tamoxifen dosing and detected a surge of perivascular macrophages before blood-brain barrier breakdown in adult stroke. When dosed by tamoxifen at embryonic day 17 (E17), this method captured fetal hematopoietic cells at E18, subdural Ki67+ ameboid cells at postnatal day 2 (P2), and perivascular microglia, leptomeningeal macrophages, and Iba1+Tmem119+P2RY12+ parenchymal microglia in selective brain regions at P24. Furthermore, this fate mapping strategy revealed an acute influx of monocytes after neonatal stroke, which gradually transformed into a ramified morphology and expressed microglial marker genes (Sall1, Tmem119, and P2RY12) for at least 62 days after injury. These results suggest an underappreciated level of monocyte-to-microglia transition in development and after neonatal stroke.

[Exploration of omics mechanism and drug prediction of coronavirus-induced heart failure based on clinical bioinformatics]

Objective: Present study investigated the mechanism of heart failure associated with coronavirus infection and predicted potential effective therapeutic drugs against heart failure associated with coronavirus infection. Methods: Coronavirus and heart failure were searched in the Gene Expression Omnibus (GEO) and omics data were selected to meet experimental requirements. Differentially expressed genes were analyzed using the Limma package in R language to screen for differentially expressed genes. The two sets of differential genes were introduced into the R language cluster Profiler package for gene ontology (GO) and Kyoto gene and genome encyclopedia (KEGG) pathway enrichment analysis. Two sets of intersections were taken. A protein interaction network was constructed for all differentially expressed genes using STRING database and core genes were screened. Finally, the apparently accurate treatment prediction platform (EpiMed) independently developed by the team was used to predict the therapeutic drug. Results: The GSE59185 coronavirus data set was searched and screened in the GEO database, and divided into wt group, ΔE group, Δ3 group, Δ5 group according to different subtypes, and compared with control group. After the difference analysis, 191 up-regulated genes and 18 down-regulated genes were defined. The GEO126062 heart failure data set was retrieved and screened from the GEO database. A total of 495 differentially expressed genes were screened, of which 165 were up-regulated and 330 were down-regulated. Correlation analysis of differentially expressed genes between coronavirus and heart failure was performed. After cross processing, there were 20 GO entries, which were mainly enriched in virus response, virus defense response, type Ⅰ interferon response, γ interferon regulation, innate immune response regulation, negative regulation of virus life cycle, replication regulation of viral genome, etc. There were 5 KEGG pathways, mainly interacting with tumor necrosis factor (TNF) signaling pathway, interleukin (IL)-17 signaling pathway, cytokine and receptor interaction, Toll-like receptor signaling pathway, human giant cells viral infection related. All differentially expressed genes were introduced into the STRING online analysis website for protein interaction network analysis, and core genes such as signal transducer and activator of transcription 3, IL-10, IL17, TNF, interferon regulatory factor 9, 2'-5'-oligoadenylate synthetase 1, mitogen-activated protein kinase 3, radical s-adenosyl methionine domain containing 2, c-x-c motif chemokine ligand 10, caspase 3 and other genes were screened. The drugs predicted by EpiMed's apparent precision treatment prediction platform for disease-drug association analysis were mainly TNF-α inhibitors, resveratrol, ritonavir, paeony, retinoic acid, forsythia, and houttuynia cordata. Conclusions: The abnormal activation of multiple inflammatory pathways may be the cause of heart failure in patients after coronavirus infection. Resveratrol, ritonavir, retinoic acid, amaranth, forsythia, houttuynia may have therapeutic effects. Future basic and clinical research is warranted to validate present results and hypothesis.

[Efficacy and safety of low-intensity pulsed ultrasound at different intervals by mechanical force in treating erectile dysfunction: a preliminary study]

Objective: To study the efficacy and safety of low-intensity pulsed ultrasound (LIPUS) at different intervals by mechanical force in treating erectile dysfunction (ED). Method: Forty patients with mild to moderate ED were randomized in a 1∶1 ratio to receive 16-treatment sessions of LIPUS in group A and group B, applied 3 times per week and 2 times per week, respectively. End-point assessments were made at 8th week after treatment. Efficacy were evaluated using International Index of Erectile Function-Erectile Function domain score (IIEF-EF), Erectile Hardness Score (EHS), Self-Esteem and Relationship Questionnaire (SEAR), Sexual Encounter Profile (SEP), Global Assessment Question (GAQ), and pain were assessed by Visual Analogue Score (VAS).Treatment response was confirmed by a minimal clinically importance difference (MCID) at 8th week. Results: Compared with baseline, IIEF-EF score [(17.1±5.48 vs 23.4±3.75, P<0.05) and (18.9±4.34 vs 24.1±4.32, P<0.05)], proportion of EHS 4 [(0 vs 40%, P<0.05) and (16.7% vs 55.6%, P<0.05)], and Overall Relationship score [(50.6 vs 67.5, P<0.05) and (44.4 vs 70.1, P<0.05)] were significantly improved at 8th week in two groups, respectively. Compared with baseline, the positive responses to SEP-3 increased significantly at 8th week in two groups (50.0% vs 80.0%,P<0.05) and (44.4% vs 88.9%, P<0.05), respectively. The positive responses to GAQ-2 were 90.0% and 88.9% at 8th week in two groups, respectively. There were no significant differences in IIEF-EF, EHS, SEAR, SEP and GAQ at 8th week between two groups. There was no significant difference in treatment response using MCID between two groups at end-point (80.5% vs 77.5%). The treatment duration for full sessions were 2.5 weeks less in group A than group B. No adverse effects were reported in all cases. Conclusion: LIPUS at two different intervals is effective and safe for mild to moderate ED, and the regimen at 3 times per week can achieve quite good effect in relatively short duration,while the long-term effects is still be clarified in further study.

Job Burnout and Occupational Stressors among Chinese Healthcare Professionals at County-Level Health Alliances

Background: This study aimed to examine the degrees of job burnout and occupational stressors and their associations among healthcare professionals from county-level health alliances in Qinghai–Tibet Plateau, China. Methods: A cross-sectional study was conducted in county-level health alliances in Qinghai Province, China, in November 2018. The Maslach Burnout Inventory—General Survey and the 38-item Chinese version of the “Scale for occupational stressors on clinicians” were used. Medical staff in four health alliances from two counties were invited to complete the questionnaire. Results: A total of 1052 (age: 34.06 ± 9.22 years, 79.1% females) healthcare professionals were included, 68.2% (95% CI: 65.2–71.0%) of the participants had job burnout symptoms. Occupational stressors had positive associations with moderate (OR = 1.06, 95% CI: 1.05–1.07) and serious (OR = 1.15, 95% CI: 1.13–1.19) level of job burnout. Stressors from vocational interest produced the greatest magnitude of odds ratio (OR = 1.76, 95% CI: 1.62–1.92) for serious degree of burnout, followed by doctor–patient relationship, interpersonal relationship as well as other domains of occupational stressors. Conclusions: Job burnout was very common among healthcare professionals working in Chinese county-level health alliances, different occupational stressors had associations with job burnout. Appropriate and effective policies and measures should be developed and implemented.

[Prospective association between childhood abuse experiences and depressive symptoms in adolescence]

Objective: To evaluate the prospective association between childhood abuse experiences and depressive symptoms in adolescence. Methods: Students in grade 3 and 4 from three primary schools were selected, with informed consent, through convenience cluster sampling in Bengbu, Anhui province in May 2013. The students' body height, weight were assessed. Childhood abuse experiences including emotional, physical or sexual abuses, as well as depressive symptoms were reported by children themselves. Data on parental educational background and household economic status were collected through parent questionnaire. A follow up was conducted 4 years later after baseline survey. Depressive symptoms were evaluated by using Children's Depression Inventory at baseline survey, and by using Mood and Feeling Questionnaire at follow-up. Logistic regression model was used to analyze the relationship between childhood abuse experiences and depressive symptoms in adolescence. Results: A total of 1 172 students were included in baseline survey, and a follow-up was conducted for 87.1% of them (n=1 021). Among 1 126 students with complete information on childhood abuse experiences at baseline survey, the reported rates of physical, emotional and sexual abuses were 12.8% (144/1 126), 11.1% (125/1 126) and 10.9% (123/1 126), respectively. The prevalence of depressive symptoms at baseline survey and follow-up was 7.0% (82/1 172) and 12.3% (126/1 021), respectively. After adjusted for baseline depressive symptoms, age at follow-up, sex, the only-child in family, household economic status, divorce of parents and BMI, childhood emotional and physical abuse experiences were significant risk factors for depressive symptoms in mid-adolescence, with the ORs were 1.86 (95%CI: 1.03-3.36, P=0.039) and 2.37 (95%CI: 1.39-4.03, P=0.001), respectively. Conclusion: Childhood physical and emotional abuse might increase the risk of depressive symptoms in adolescence.

Designed Macrocyclic Peptides as Nanomolar Amyloid Inhibitors Based on Minimal Recognition Elements

Amyloid self-assembly is linked to the pathogenesis of Alzheimer's disease (AD) and type 2 diabetes (T2D), but so far, no anti-amyloid compound has reached the clinic. Macrocyclic peptides belong to the most attractive drug candidates. Herein we present macrocyclic peptides (MCIPs) designed using minimal IAPP-derived recognition elements as a novel class of nanomolar amyloid inhibitors of both Aβ40(42) and IAPP or Aβ40(42) alone and show that chirality controls inhibitor selectivity. Sequence optimization led to the discovery of an Aβ40(42)-selective MCIP exhibiting high proteolytic stability in human plasma and human blood-brain barrier (BBB) crossing ability in a cell model, two highly desirable properties for anti-amyloid AD drugs. Owing to their favorable properties, MCIPs should serve as leads for macrocyclic peptide-based anti-amyloid drugs and scaffolds for the design of small-molecule peptidomimetics for targeting amyloidogenesis in AD or in both AD and T2D.

Dengue virus non-structural protein 1: a pathogenic factor, therapeutic target, and vaccine candidate

Dengue virus (DENV) infection is the most common mosquito-transmitted viral infection. DENV infection can cause mild dengue fever or severe dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS). Hemorrhage and vascular leakage are two characteristic symptoms of DHF/DSS. However, due to the limited understanding of dengue pathogenesis, no satisfactory therapies to treat nor vaccine to prevent dengue infection are available, and the mortality of DHF/DSS is still high. DENV nonstructural protein 1 (NS1), which can be secreted in patients’ sera, has been used as an early diagnostic marker for dengue infection for many years. However, the roles of NS1 in dengue-induced vascular leakage were described only recently. In this article, the pathogenic roles of DENV NS1 in hemorrhage and vascular leakage are reviewed, and the possibility of using NS1 as a therapeutic target and vaccine candidate is discussed.

Prenatal Maternal Immune Activation Sensitizes the Neuroinflammatory Responses to Neonatal Hypoxic-Ischemic Brain Injury

Epidemiological evidence suggests that prenatal maternal immune activation (MIA) is a risk factor for autism spectrum disorders (ASD). Yet, because not all human MIA offspring develop ASD, we hypothesize that “second hits” may be needed to induce severe brain damage and disruption of the neural network. We tested this hypothesis using an established MIA model with Poly I:C (20 mg/kg) intraperitoneally injected at mid pregnancy (E12.5) in C57BL/6 mice. The offspring were challenged by mild hypoxia-ischemia (HI) at P10 as the second hit. We found that MIA alone infrequently caused clusters of amoeboid microglial cells (AMCs) expressing a high level of Complement component 3 (C3) in the offspring brains. Elevated NFkB signaling and a higher basal level of IL-6, IL-17 and MMP9 mRNA were also detected in the P11 MIA offspring brains. When challenged by HI, the MIA offspring showed significantly greater NFkB activity, TUNEL-positive apoptosis, and mRNAs for pro-inflammatory cytokines including IL-6, IL-17, TNFα, IL-23, TSPO and MCP-1 at 24 h post-injury, when compared to those injured by HI alone. At 7 d recovery, the MIA/HI-injured mice showed more AMCs, monocyte infiltration, and greater brain atrophy than singularly MIA- or HI-injured mice. Finally, the MIA/HI-injured mouse brains showed a significant reduction of PSD95 and synaptotagmin/PSD-96 punctates, correlated with greater C3 expression in the hippocampal CA2/3 region than MIA alone or HI-injured counterparts. Together, these results suggest that MIA elevates the inflammatory activity in the offspring brain, and acts as a primer to sensitize the neuroinflammatory responses to a secondary insult, leading to greater brain damage, and potentially ASD-like cognitive deficits.

Macrophage migration inhibitory factor is critical for dengue NS1-induced endothelial glycocalyx degradation and hyperpermeability

Vascular leakage is one of the salient characteristics of severe dengue. Nonstructural protein 1 (NS1) of dengue virus (DENV) can stimulate endothelial cells to secrete endothelial hyperpermeability factor, macrophage migration inhibitory factor (MIF), and the glycocalyx degradation factor heparanase 1 (HPA-1). However, it is unclear whether MIF is directly involved in NS1-induced glycocalyx degradation. In this study, we observed that among NS1, MIF and glycocalyx degradation-related molecules, the HPA-1, metalloproteinase 9 (MMP-9) and syndecan 1 (CD138) serum levels were all increased in dengue patients, and only NS1 and MIF showed a positive correlation with the CD138 level in severe patients. To further characterize and clarify the relationship between MIF and CD138, we used recombinant NS1 to stimulate human cells in vitro and challenge mice in vivo. Our tabulated results suggested that NS1 stimulation could induce human endothelial cells to secrete HPA-1 and immune cells to secrete MMP-9, resulting in endothelial glycocalyx degradation and hyperpermeability. Moreover, HPA-1, MMP-9, and CD138 secretion after NS1 stimulation was blocked by MIF inhibitors or antibodies both in vitro and in mice. Taken together, these results suggest that MIF directly engages in dengue NS1-induced glycocalyx degradation and that targeting MIF may represent a possible therapeutic approach for preventing dengue-induced vascular leakage.

In vitro Assays for Measuring Endothelial Permeability byTranswells and Electrical Impedance Systems

Vascular leakage is an important feature in several diseases, such as septic shock, viral hemorrhagic fever, cancer metastasis and ischemia-reperfusion injuries. Thus establishing assays for measuring endothelial permeability will provide insight into the establishment or progression of such diseases. Here, we provide transwell permeability assay and electrical impedance sensing assay for studying endothelial permeability in vitro. With these methods, the effect of a molecule on endothelial permeability could be defined.

Cdk12 Regulates Neurogenesis and Late-Arising Neuronal Migration in the Developing Cerebral Cortex

DNA damage response (DDR) pathways are critical for ensuring that replication stress and various types of DNA lesion do not perturb production of neural cells during development. Cdk12 maintains genomic stability by regulating expression of DDR genes. Mutant mice in which Cdk12 is conditionally deleted in neural progenitor cells (NPCs) die after birth and exhibit microcephaly with a thinner cortical plate and an aberrant corpus callosum. We show that NPCs of mutant mice accumulate at G2 and M phase, and have lower expression of DDR genes, more DNA double-strand breaks and increased apoptosis. In addition to there being fewer neurons, there is misalignment of layers IV-II neurons and the presence of abnormal axonal tracts of these neurons, suggesting that Cdk12 is also required for the migration of late-arising cortical neurons. Using in utero electroporation, we demonstrate that the migrating mutant cells remain within the intermediate zone and fail to adopt a bipolar morphology. Overexpression of Cdk5 brings about a partially restoration of the neurons reaching layers IV-II in the mutant mice. Thus, Cdk12 is crucial to the repair of DNA damage during the proliferation of NPCs and is also central to the proper migration of late-arising neurons.

Dengue Virus Nonstructural Protein 1 Induces Vascular Leakage through Macrophage Migration Inhibitory Factor and Autophagy

Dengue virus (DENV) is the most common mosquito-borne flavivirus; it can either cause mild dengue fever or the more severe dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). One of the characteristic features of DHF/DSS is vascular leakage; although DENV nonstructural protein 1 (NS1) has been proved to induce vascular leakage after binding to Toll-like receptor 4, the down-stream mechanism has not yet been fully understood. In the sera of DENV-infected patients, the concentrations of DENV NS1 and inflammatory cytokine macrophage migration inhibitory factor (MIF) are positively correlated with disease severity, but whether DENV NS1 induces vascular leakage through MIF secretion remains unknown. We demonstrated that recombinant NS1 induced vascular leakage and MIF secretion both in human endothelial cell line HMEC-1 and in mice. Furthermore, these phenomena were inhibited in the presence of anti-NS1 antibodies both in vitro and in vivo. DENV NS1 also induced LC3-I to LC3-II conversion and p62 degradation in endothelial cell line, which indicated the formation of autophagy. To clarify whether MIF or autophagy mediated DENV NS1-induced vascular leakage, various inhibitors were applied. The results showed that DENV NS1-induced vascular leakage and VE-cadherin disarray were blocked in the presence of MIF inhibitors, anti-MIF-antibodies or autophagy inhibitors. An Atg5 knockdown clone further confirmed that autophagy formation of endothelial cells was required in NS1-induced vascular leakage. Furthermore, DENV NS1-induced LC3 puncta were also decreased in the presence of MIF inhibitors, indicating that MIF mediated DENV NS1-induced autophagy. Taken together, the results suggest a potential mechanism of DENV-induced vascular leakage and provide possible therapeutic targets against DHF/DSS.

Macrophage migration inhibitory factor induces vascular leakage via autophagy

Vascular leakage is an important feature of acute inflammatory shock, which currently has no effective treatment. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that can induce vascular leakage and plays an important role in the pathogenesis of shock. However, the mechanism of MIF-induced vascular leakage is still unclear. In this study, using recombinant MIF (rMIF), we demonstrated that MIF induced disorganization and degradation of junction proteins and increased the permeability of human endothelial cells in vitro. Western blotting analysis showed that rMIF treatment induced LC3 conversion and p62 degradation. Inhibition of autophagy with a PI3K inhibitor (3-MA), a ROS scavenger (NAC) or autophagosomal-lysosomal fusion inhibitors (bafilomycin A1 and chloroquine) rescued rMIF-induced vascular leakage, suggesting that autophagy mediates MIF-induced vascular leakage. The potential involvement of other signaling pathways was also studied using different inhibitors, and the results suggested that MIF-induced vascular leakage may occur through the ERK pathway. In conclusion, we showed that MIF triggered autophagic degradation of endothelial cells, resulting in vascular leakage. Inhibition of MIF-induced autophagy may provide therapeutic targets against vascular leakage in inflammatory shock.

Cdk12 and Cdk13 regulate axonal elongation through a common signaling pathway that modulates Cdk5 expression

Cdk12 and Cdk13 are Cdc2-related proteins that share 92% identity in their kinase domains. Using in situ hybridization and Western blot analysis, we detected the expression of Cdk12 and Cdk13 mRNAs and their proteins in developing mouse embryos, especially during development of the nervous system. We explored the roles of Cdk12 and Cdk13 in neuronal differentiation using the P19 neuronal differentiation model. Upon knockdown of Cdk12 or Cdk13, no effect on differentiated cell numbers was detected, but a substantial decrease of numbers of neurons with long neurites was identified. Similarly, knockdown of Cdk12 or Cdk13 in primarily cultured cortical neurons shortens the averaged axonal length. A microarray analysis was used to examine changes in gene expression after knockdown or overexpression of Cdk12 and we identified Cdk5 as a molecule potentially involved in mediating the effect of Cdk12 and Cdk13. Depletion of Cdk12 or Cdk13 in P19 cells significantly reduces Cdk5 expression at both the mRNA and protein levels. Expression of Cdk5 protein in the developing mouse brain is also reduced in conditional Cdk12-knockout mice in proportion to the residual amount of Cdk12 protein present. This suggests that the reduced axonal outgrowth after knockdown of Cdk12 or Cdk13 might be due to lower Cdk5 expression. Furthermore, overexpression of Cdk5 protein in P19 cells was able to partially rescue the neurite outgrowth defect observed when Cdk12 or Cdk13 is depleted. Together, these findings suggest that Cdk12 and Cdk13 regulate axonal elongation through a common signaling pathway that modulates Cdk5 expression.

Re-evaluation of the pathogenic roles of nonstructural protein 1 and its antibodies during dengue virus infection

Dengue virus (DENV) infection can cause life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Vascular leakage and abnormal hemorrhage are the two major pathogenic changes found in these patients. From previous studies, it is known that both antibodies and cytokines induced in response to DENV infection are involved in the immunopathogenesis of DHF/DSS. However, the role of viral factors during DENV infection remains unclear. Nonstructural protein 1 (NS1), which is secreted in the sera of patients, is a useful diagnostic marker for acute DENV infection. Nevertheless, the roles of NS1 and its antibodies in the pathogenesis of DHF/DSS are unclear. The focus of this review is to evaluate the possible contributions of NS1 and the antibodies it induces to vascular leakage and abnormal hemorrhage during DENV infection, which may provide clues to better understanding the pathogenesis of DHF/DSS.

First Report of Basella rugose mosaic virus Infecting Four O'Clock (Mirabilis jalapa) in China

Four o'clock (Mirabilis jalapa) and M. himalaica var. chinensis are members of the family Nyctaginaceae and are widely distributed weeds in Yunnan Province, China. In 2009, mosaic and malformation symptoms were observed on leaves of the four o'clock on the campus of Yunnan Agricultural University and in the Black Dragon Pool Park in Kunming City, China. More than 30% of the four o'clock plants showed symptoms of the disease. Sap from leaves of symptomatic four o'clock plants caused local chlorotic and necrotic lesions in inoculated Chenopodium amaranticolor after 7 to 10 days and systemic mosaic symptoms in C. quinoa and Nicotiana benthamiana after 10 to 12 days. No symptoms were observed following inoculation of sap from asymptomatic plants. A pure virus isolate (MJ) was obtained after three successive single-lesion transfers from C. amaranticolor. Following mechanical inoculation of the MJ isolate, seedlings of indicator plants, N. benthamiana, displayed mosaic symptoms. Moreover, back transmission to healthy four o'clock seedlings by leaf extracts from systemically infected N. benthamiana plants caused similar mosaic and malformation symptoms. Flexuous, filamentous particles (650 to 700 nm long and 13 nm wide) and cytoplasmic laminar aggregates and pinwheel inclusions typical of members of the genus Potyvirus were observed in infected four o'clock leaves by electron microscopy. No other virus particles were observed. Serological testing of 10 symptomatic and healthy plants using a monoclonal antibody specific for Potyvirus group members in an indirect ELISA (Agdia Inc., Elkhart, IN) also resulted in positive reactions in infected leaves, however, all healthy seedlings tested were negative. Total RNAs were extracted from infected four o'clock leaves with the RNeasy Plant Mini Kit (QIAGEN, Hilden, Germany) and the 3'-terminal portion of the viral genome (including part of the NIb polymerase, the entire coat protein (CP), and 3'-UTR) was then amplified by reverse transcription-PCR with a universal Potyviridae primer Sprimer/M4 and an M4T as the initial primer (2). A fragment of 1,720 nucleotides long were separated, purified, and cloned and three independent clones were sequenced (GenBank Accession No. JN250997). Nucleotide and amino acid sequence analysis of the putative CP gene, respectively, revealed 75.1 to 76.3% and 80.3 to 82.1% identity with the Basella rugose mosaic virus (BaRMV) (GenBank Accession Nos. DQ821938, DQ394891, and DQ821939), 77.4 and 81.0% identity with Peace lily mosaic virus (GenBank Accession No. DQ851494), and 76.0 and 81.7% identity with the Phalaenopsis chlorotic spot virus (GenBank Accession No. HM021142). However, on the basis of the CP gene sequence analyses, these three viruses shared high (>88.5 and >94.3%) CP nucleotide and amino acid identity and should be classified as the same Potyvirus species. According to the species demarcation criteria for the Potyviridae (1), the pathogen causing mosaic and malformation symptoms on four o'clock was BaRMV (3). To our knowledge, this is the first report of BaRMV in four o'clock. References: (1) M. J. Adams et al. Arch. Virol. 150:459, 2005. (2) J. Chen et al. Arch. Virol. 146:757, 2001. (3) C. H. Hung and Y. C. Chang. Plant Pathol. 55:819, 2006.

Zebrafish sod1 and sp1 expression are modulated by the copper ATPase gene atp7a in response to intracellular copper status

Copper is an essential trace metal for physiological functions, whereas copper overload causes cytotoxicity in living organisms. Genetically determined systems regulate acquisition, distribution and storage for copper maintenance and homeostasis. The Human ATP7A copper transport ATPase modulates intracellular copper distribution, which is critical for copper-dependent enzymes such as superoxide dismutase (SOD1). To investigate the role of zebrafish ATP7A in copper homeostasis, zebrafish atp7a gene expression was reduced for analysis of downstream cellular function. The results demonstrated that zebrafish sod1 has lower expression in atp7a-knockdown fish. Similarly, zebrafish sp1, a transcriptional regulator of sod1, also shows reduced expression in atp7a-knockdown fish. The lower expression of sod1 resulting from atp7a knockdown is independent to p53 gene activation. The knockdown of atp7a and copper chelator NeoC results in hypopigmentation and notochord deformation in zebrafish. Addition of exogenous copper alleviated the impaired development. Interestingly, both sod1 and sp1 transcripts are reduced in the presence of NeoC and increased with exogenous copper, suggesting that the expression of sod1 and sp1 are directly affected by copper status. This is the first report to demonstrate a hierarchic gene expression of copper homeostatic genes between atp7a, sp1 and sod1 in zebrafish.

Cadmium tolerance of carbon assimilation enzymes and chloroplast in Zn/Cd hyperaccumulator Picris divaricata

To better understand the photosynthesis under stress, the effect of cadmium on carbon assimilation and chloroplast ultrastructure of a newly found Zn/Cd hyperaccumulator Picris divaricata in China was investigated in solution culture. The shoot and root Cd concentrations increased with increase in Cd supply, reaching maxima of 1109 and 5604mgkg(-1) dry weight at 75microM Cd, respectively. As Cd supply to P. divaricata increased, the shoot and root dry weight, leaf water content (except 75microM Cd), concentrations of chlorophyll a and b, chlorophyll a/b ratio and the concentration of carotenoids were not depressed at high Cd. However, the stomatal conductance, transpiration rate, net photosynthetic rate and intercellular CO(2) concentration were significantly affected when the Cd concentration reached 10, 10, 25 and 75microM, respectively. Meanwhile, carbonic anhydrase (CA; EC 4.2.1.1) activity and Rubisco (EC 4.1.1.39) content reached maxima in the presence of 50 and 5microM Cd, respectively. In addition, CA activity correlated positively with shoot Cd in plants treated with Cd at a range of 0-50microM. Moreover, the activities of NADP(+)-glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.13), Rubisco and fructose-1, 6-bisphosphatase (EC 3.1.3.11) were not significantly suppressed by increased Cd supply. Although the mesophyll cell size was reduced, chloroplast ultrastructure remained intact at the highest Cd treatment. Our finding revealed that P. divaricata chloroplast and the enzymes of carbon assimilation tolerate high levels of Cd, demonstrating its potential in possible application in phytoremediation.

First Report of Botryosphaeria dothidea Causing Canker and Shoot Blight of Eucalyptus in China

Eucalyptus spp. are grown on approximately 2 million ha in China and is the most important genus in forest plantations worldwide. An outbreak of cankers and shoot blight was observed for the first time on Eucalyptus grandis in China during May of 2008. Symptoms included dieback of shoots and branches, lesions and canker formation on the stems, and clear or yellow-to-red exudates on stems and branches. Isolations were made from affected trees in Shilin County from May to July of 2008. Diseased samples were plated on potato dextrose agar (PDA) and incubated at 26°C. Fungal isolates developed copious, white, aerial mycelium that became dark gray after 5 to 6 days and formed black pycnidia after 14 days. Conidia were hyaline, aseptate, thin walled, fusiform, and measured 19 to 28 × 4 to 6 μm. Ascospores were hyaline, aseptate, and widest from the middle to upper third (17 to 28 × 6 to 13 μm). Identity was confirmed by analysis of the rDNA internal transcribed spacer region (ITSI-5.8S-ITS2) with primers ITS1 and ITS4. BLAST searches showed 99 to 100% identity with Botryosphaeria dothidea isolates from GenBank (Accession Nos. FJ358703 and EU080916). Representative sequences of B. dothidea from eucalyptus from China were deposited into GenBank (Accession Nos. FJ517657 and FJ517658). On the basis of morphological and molecular results, the fungus isolated from diseased eucalyptus wood was confirmed to be B. dothidea. Pathogenicity tests were conducted by stem inoculation of 10-month-old E. grandis seedlings. Two experiments were conducted using two inoculation techniques. In the first experiment, 2-mm-diameter actively growing mycelium plugs of B. dothidea were applied to 2-mm-long bark wounds on the middle point of the stems, and control seedlings were inoculated with sterile PDA plugs in a similar fashion as above. Inoculated and control seedlings were inoculated in a greenhouse and watered as needed. In the second experiment, segments of branches (averaging 18 mm in diameter and 30 cm long) were inoculated with 5-mm-diameter plugs of actively growing mycelium. Control segments of branches were inoculated as previously described. The branches were incubated at 26°C in moist chambers. There were five replicate seedlings per inoculation technique. After 20 days, all E. grandis seedlings showed leaf wilting, Dark, vascular stem tissue was observed. Symptoms were more abundant on the segment of branches. After 6 days, vascular necroses that developed on the inoculated plants were 5.2 ± 1.2 cm. B. dothidea was reisolated from all inoculated symptomatic tissue; no symptoms were visible in the control seedlings and no fungus was isolated from them. These results confirm previous reports of B. dothidea causing canker and dieback symptoms of Eucalyptus species in Australia (2), the United States (1), and South Africa (3). To our knowledge, this is the first report of B. dothidea causing canker disease on eucalyptus in China. References: (1) E. L. Barnard et al. Plant Dis. 71:358, 1987. (2) E. M. Davison and C. S. Tay. Plant Dis. 67:1285, 1983. (3) H. Smith et al. Plant Pathol. 43:1031, 1994.

First Report of Pomegranate Wilt Caused by Ceratocystis fimbriata in Yunnan, China

Pomegranate (Punica granatum Linn.) is an important fruit crop in Yunnan Province, China. Recently, older pomegranate bushes in Mengzi County, Yunnan began dying. Initial symptoms were yellowing and wilting of leaves on one to several branches, followed by sudden death of the bush within 3 to 4 weeks. Roots of diseased bushes appeared brown to black, and irregularly shaped lesions were observed when the bark was removed. A species of Ceratocystis was consistently isolated from discolored roots, stem, and branch tissues from wilted bushes on potato dextrose agar (PDA) and was identified as Ceratocystis fimbriata Ellis & Halst, based on the morphology of perithecia, ascospores, conidia, and conidiophores. Perithecia were black with a globose base (130 to 300 μm) and a long neck (450 to 800 μm). Ascospores exuded from the apex of the perithecium neck in a long coil and were small, hyaline, and hat-shaped (3.8 to 5.0 μm long × 2.3 to 4.0 μm wide). Conidiophores were septate and hyaline to dark greenish brown. Hyaline conidia, 8 to 17 μm long × 6 to 15 μm wide, were usually produced in chains of 10 or more. Thick-walled endoconidia were globose to oval, olive brown, and 8 to 20 μm in diameter. Because of the increasing occurrence of the disease, surveys of the main pomegranate production areas in Mengzi County, including Xinan, Duofale, Caoba, Hongzhai, and Shilipu townships, were conducted from 10 to 20 August 2002. The disease was detected in 17 of 50 plantings surveyed. Disease was more severe in older plantings than in younger plantings. Disease incidence was 1% in 1- to 5-year-old bushes, 3.6% in 6- to 10-year-old bushes, and 6% in bushes more than 10 years old. Scolytid beetles were occasionally found on bushes, but we were unable to isolate the fungus from them as has been reported (1). Inoculations with an isolate of C. fimbrata were made by inserting mycelium with perithecia from 12-day-old cultures growing on PDA into root wounds made with a sterile scalpel on five pomegranate plants and then covering the wounds with Parafilm. Sterile medium was placed in an equal number of wounded bushes to serve as controls. Fourteen days later, symptoms began to appear in two bushes, and 5 days later, all bushes exhibited symptoms. No symptoms were observed on control bushes. The first visible symptom was a small area of blackened tissue near the point of inoculation. Lesions expanded slowly, but they expanded more rapidly upward than downward. The fungus was reisolated on PDA from roots of all artificially inoculated bushes. C. fimbriata has been previously reported as the cause of pomegranate wilt in India (2); however, to our knowledge, this is the first report of C. fimbriata on pomegranate in China. Because environmental conditions which favor the pathogen (temperatures ranging from 18 to 30°C and frequent rains) typically occur in many areas during late spring and summer, the disease has the potential to seriously impact pomegranate production in China. References: (1) Y. M. Somasekhara. Plant Dis. 83:400, 1999. (2) Y. M. Somasekhara, et al. Res. Crops 1(1):63, 2000.

Complete nucleotide sequence and genome organization of a Chinese isolate of tobacco bushy top virus

The complete nucleotide sequence of a Chinese isolate of tobacco bushy top virus (TBTV), designated TBTV-Ch, was determined from cDNA generated from double-stranded RNA extracted from diseased tobacco. The genome is 4152 nucleotides (nt) in size, contains four putative open reading frames (ORFs) and untranslated regions of 10 nt and 645 nt at the 5' and 3' ends, respectively. In genome organization and in the amino acid sequence of its potential products, the RNA of TBTV-Ch is similar to other umbraviruses sequenced to date. The results suggested that TBTV should be regarded as a definitive species of the genus Umbravirus.

Diagnosis and treatment of congenital choledochal cyst: 20 years' experience in China

AIM

To summarize the experience of diagnosis and treatment of congenital choledochal cyst in the past 20 years (1980-2000).

METHODS

The clinical data of 108 patients admitted from 1980 to 2000 were analyzed retrospectively.

RESULTS

Abdominal pain,jaundice and abdominal mass were presented in most child cases. Clinical symptoms in adult cases were non-specific, resulting in delayed diagnosis frequently. Fifty-seven patients (52.7%) had coexistent pancreatiobiliary disease. Carcinoma of the biliary duct occurred in 18 patients (16.6%). Ultrasonic examination was undertaken in 94 cases, ERCP performed in 46 cases and CT in 71 cases. All of the cases were correctly diagnosed before operation. Abnormal pancreatobiliary duct junction was found in 39 patients. Before 1985 the diagnosis and classification of congenital choledochal cyst were established by ultrasonography preoperatively and confirmed during operation, the main procedures were internal drainage by cyst enterostomy. After 1985, the diagnosis was established by ERCP and CT, and cystectomy with Roux-en-Y hepaticojejunostomy was the conventional procedures.In 1994, we reported a new and simplified operative procedure in order to reduce the risk of choledochal cyst malignancy. Postoperative complication was mainly retrograde infection of biliary tract, which could be controlled by the administration of antibiotics, there was no perioperative mortality.

CONCLUSION

The concept in diagnosis and treatment of congenital choledochal cyst has obviously been changed greatly.CT and ERCP were of great help in the classification of the disease.Currently, cystectomy with Roux-en-Y hepaticojejunostomy is strongly recommended as the choice for patients with type I and type IV cysts. Piggyback orthotopic liver transplantation is indicated in type V cysts (Caroli's disease) with frequently recurrent cholangitis.

Diagnosis and treatment of congenital choledochal cyst: 20 years′ experience in China

AIM: To summarize the experience of diagnosis and treatment of congenital choledochal cyst in the past 20 years (1980-2000).

METHODS: The clinical data of 108 patients admitted from 1980 to 2000 were analyzed retrospectively.

RESULTS: Abdominal pain, jaundice and abdominal mass were presented in most child cases. Clinical symptoms in adult cases were non-specific, resulting in delayed diagnosis frequently. Fifty-seven patients (52.7%) had coexistent pancreatiobiliary disease. Carcinoma of the biliary duct occurred in 18 patients (16.6%). Ultrasonic examination was undertaken in 94 cases, ERCP performed in 46 cases and CT in 71 cases. All of the cases were correctly diagnosed before operation. Abnormal pancreatobiliary duct junction was found in 39 patients. Before 1985 the diagnosis and classification of congenital choledochal cyst were established by ultrasonography preoperatively and confirmed during operation, the main procedures were internal drainage by cyst enterostomy. After 1985, the diagnosis was established by ERCP and CT, and cystectomy with Roux-en-Y hepaticojejunostomy was the conventional procedures. In 1994, we reported a new and simplified operative procedure in order to reduce the risk of choledochal cyst malignancy. Postoperative complication was mainly retrograde infection of biliary tract, which could be controlled by the administration of antibiotics, there was no perioperative mortality.

CONCLUSION: The concept in diagnosis and treatment of congenital choledochal cyst has obviously been changed greatly. CT and ERCP were of great help in the classification of the disease. Currently, cystectomy with Roux-en-Y hepaticojejunostomy is strongly recommended as the choice for patients with type I and type IV cysts. Piggyback orthotopic liver transplantation is indicated in type V cysts (Caroli’s disease) with frequently recurrent cholangitis.

The effect of G-CSF-stimulated donor marrow on engraftment and incidence of graft-versus-host disease in allogeneic bone marrow transplantation

Graft-versus-host disease (GVHD) and infection are major obstacles to successful allogeneic bone marrow transplantation (allo-BMT). In an attempt to improve the results of HLA-identical sibling BMT, we investigated the effect of accelerating hemopoietic reconstitution and reducing acute GVHD (aGVHD) in allo-BMT receiving G-CSF-stimulated donor marrow and the preliminary biological mechanism. The donors of 30 patients (study group) with leukemia were given G-CSF 3-4 microg/kg/d for 7 doses prior to marrow harvest. The results of subsequent engraftment in the recipients were compared with those of 18 patients without G-CSF (control group). Five donors themselves were studied to assess the effects of G-CSF on the hematopoietic progenitor cells and lymphocyte subsets in the bone marrow (BM). We observed that the stimulated BM yielded higher numbers of nucleated cells as well as CFU-GM and CD34+ cells (p<0.01), and that hemopoietic reconstitution was accelerated. The median number of days of granulocyte count exceeding 0.5x10(9)/L and platelet count exceeding 20x10(9)/L was 16 (range 10-23 d) and 18.5 (range 13-31 d), respectively (control group: median 22 d, range 13-29 d and median 23 d, range 17-34 d; p=0.001). The incidence of grade II-IV severe aGVHD was very low, with only 1 case (3.3%) with acute grade II aGVHD limited to the skin in the study group. Five of 18 patients in the control group manifested grade II-IV severe aGVHD (27.8%, p=0.02). The number of T-lymphocyte subsets in the harvested BM using G-CSF stimulation was changed. In the G-CSF-stimulated marrow group, CD4+ decreased and CD8+ increased significantly (p=0.02). The changes of progenitor cells and T-lymphocyte subsets in donors' BM from pre- and post-G-CSF stimulation showed that the percentage of CD4+ reduced (p=0.04) and that of CD8+ increased (p=0.06), while that of CD34+ also increased (p=0.002). The incidence of chronic GVHD and relapse had no significant difference between both groups. These results indicate that allo-BMT in BM G-CSF priming can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favor of improved transplantation-related mortality.

Magnolol reduces myocardial ischemia/reperfusion injury via neutrophil inhibition in rats

The accumulation of oxygen-free radicals and activation of neutrophils are strongly implicated as important pathophysiological mechanisms mediating myocardial ischemia/reperfusion injury. It has been proven that various antioxidants have cardioprotective effects. Magnolol, an active component extracted from the Chinese medicinal herb Magnolia officinalis, possesses potent antioxidant and free radical scavenging activities. In this study, the cardioprotective activity of magnolol was evaluated in an open-chest anesthetized rat model of myocardial ischemia/reperfusion injury. The results demonstrated that pretreatment with magnolol (0.2 and 0.5 microg/kg, i.v. bolus) at 10 min before 45 min of left coronary artery occlusion, significantly suppressed the incidence of ventricular fibrillation and mortality when compared with the control group. Magnolol (0.2 and 0.5 microg/kg) also significantly reduced the total duration of ventricular tachycardia and ventricular fibrillation. After 1 h of reperfusion, pretreatment with magnolol (0.2 and 0.5 microg/kg) caused a significant reduction in infarct size. In addition, magnolol (0.2 microg/kg) significantly reduced superoxide anion production and myeloperoxidase activity, an index of neutrophil infiltration in the ischemic myocardium. In addition, pretreatment with magnolol (0.2 and 0.5 microg/kg) suppressed ventricular arrhythmias elicited by reperfusion following 5 min of ischemia. In vitro studies of magnolol (5, 20 and 50 microM) significantly suppressed N-formylmethionyl-leucyl-phenylalanine (fMLP; 25 nM)-activated human neutrophil migration in a concentration-dependent manner. It is concluded that magnolol suppresses ischemia- and reperfusion-induced ventricular arrhythmias and reduces the size of the infarct resulting from ischemia/reperfusion injury. This pronounced cardioprotective activity of magnolol may be mediated by its antioxidant activity and by its capacity for neutrophil inhibition in myocardial ischemia/reperfusion.

Identification and characterization of two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p

The yeast Saccharomyces cerevisiae Prp19p protein is an essential splicing factor and a spliceosomal component. It is not tightly associated with small nuclear RNAs (snRNAs) but is associated with a protein complex consisting of at least eight proteins. We have identified two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p. Like other identified components of the complex, both Ntc30p and Ntc20p are associated with the spliceosome in the same manner as Prp19p immediately after or concurrently with dissociation of U4, indicating that the entire complex may bind to the spliceosome as an intact form. Neither Ntc30p nor Ntc20p directly interacts with Prp19p, but both interact with another component of the complex, Ntc85p. Immunoprecipitation analysis revealed an ordered interactions of these components in formation of the Prp19p-associated complex. Although null mutants of NTC30 or NTC20 showed no obvious growth phenotype, deletion of both genes impaired yeast growth resulting in accumulation of precursor mRNA. Extracts prepared from such a strain were defective in pre-mRNA splicing in vitro, but the splicing activity could be restored upon addition of the purified Prp19p-associated complex. These results indicate that Ntc30p and Ntc20p are auxiliary splicing factors the functions of which may be modulating the function of the Prp19p-associated complex.

Simultaneous HPLC of twelve monoamines and metabolites shows neuroblastoma cell line releases HVA and HIAA

Neuroblastoma is a solid tumor occurring usually in children less than 5 years old. It has been difficult to distinguish neuroblastoma from other childhood tumors through morphological diagnosis. Urine homovanillic acid (HVA), which is a metabolite of dopamine, has been proposed as a diagnostic index. Although increased levels of a serotonin metabolite, 5-hydroxyindole-3-acetic acid (HIAA), have also been observed in urine samples of the patients, they were largely attributed to dietary amines. By using an HPLC system with electrochemical detection, which can simultaneously assay 12 monoamines and metabolites, we showed that HVA and HIAA are two of the most prominent monoamine metabolites in the medium after a neuroblastoma cell line (IMR-32) was cultured for 3 days. Moreover, we found that the levels of HVA and HIAA in the media are proportional to the cell densities. These results suggest that the levels of HVA and HIAA in tissue culture media, or in urine from patients whose dietary amines are well controlled, may provide a valuable diagnostic index for neuroblastoma.