Manganese disrupts the maturation and degradation of axonal autophagosome leading to hippocampal synaptic toxicity in mice via the activation of LRRK2 on phosphorylation of Rab10

Manganese (Mn) overexposure induces hippocampal synaptotoxicity by the accumulation of dysfunctional synaptic vesicles (SVs). Leucine-rich repeat kinase 2 (LRRK2) kinase activity is involved in regulating axonal transport (autophagosomal maturation) and lysosomal function. Nevertheless, it remains unclear whether Mn-induced synaptotoxicity is associated with the LRRK2-mediated disruption of autophagosomal maturation in axonal transport and the impairment of lysosomes in hippocampal neurons. Here, we established models of manganism in C57BL/6 mice and hippocampal neuronal HT22 cells to verify the role of LRRK2-mediated Rab10 phosphorylation in the Mn-induced dysfunction of autophagy- lysosomal fusion. Our results proved that Mn-induced the disorder of axonal transport and that lysosome impairments were associated with the increased recruitment of phospho-Rab10 at the axon and lysosomes. Next, we established Lrrk2-KD and LRRK2 kinase- specific inhibitor (GNE-0877, GNE) pre-treated HT22 cells to inhibit Lrrk2 gene expression and kinase activity, respectively. In Mn-treated Lrrk2-KD or GNE-pretreated normal neurons, our results indicated that lysosomal pH and integrity and autophagic flow were restored, indicating by decreased levels of phospho-Rab10 on lysosomes and JNK-interacting proteins (JIP4). In addition, GNE pretreatment could provide protection against Mn-induced synaptotoxicity in vivo, which was evidenced by the partial recovery in synaptic plasticity and synaptic damage. Thus, the Mn-induced abnormal activation of LRRK2 affected lysosomes and the recruitment of phospho-Rab10 by JIP4, which disrupted autophagosomal maturation in proximal axons and resulted in the hippocampal synaptic toxicity of mice.

Manganese-induced α-synuclein overexpression promotes the accumulation of dysfunctional synaptic vesicles and hippocampal synaptotoxicity by suppressing Rab26-dependent autophagy in presynaptic neurons

Manganese (Mn) overexposure induces learning and memory impairments in mice by disrupting the functions of synapses and synaptic vesicles (SVs) in the hippocampus, which is associated with α-synuclein (α-Syn) overexpression. Rab26-dependent autophagy is a key signaling step required for impaired SV clearance; however, it is unclear whether Mn-induced α-Syn overexpression is linked to dysregulated Rab26-dependent autophagy in presynaptic neurons. In this study, we developed manganism models in male C57BL/6 mice and hippocampal primary neurons to observe the associations between Mn-induced α-Syn overexpression and impaired SV accumulation. The results of the in vivo experiments showed that 100 and 200 μmol/kg Mn exposure significantly impaired memory and synaptic plasticity in the mice, which was related to the accumulation of impaired SVs in the hippocampus. Consistent with the in vivo outcomes, the level of in vitro injured SVs in the 50 and 100 μmol/L Mn-exposed neuron group were higher than that in the control group. Moreover, 100 μmol/L Mn suppressed the initiation of Rab26-dependent autophagy at the synapse. Then, we transfected neurons with LV-α-Syn short hairpin RNA (shRNA) and exposed the neurons to Mn for an additional 24 h. Surprisingly, the area of colocalization between Rab26 and Atg16L1 and the expression level of LC3II-positive SVs were both higher in Mn-exposed LV-α-Syn shRNA-transfected neurons than those in Mn-treated normal or Mn-treated LV-scrambled shRNA-transfected neurons. Thus, Mn-induced α-Syn overexpression was responsible for the dysregulation of Rab26-dependent autophagy, thereby promoting the accumulation of injured SVs, and causing synaptotoxicity and cognitive and memory deficits in mice.

Selenylation to charge transfer improvement at the counter electrode (CE)/electrolyte interface for nanocrystalline Cu1.8S1-xSex CEs

Pt counter electrodes (CEs) have been widely used in dye-sensitized solar cells (DSSCs) due to their high conductivity and electrocatalytic activity. However, industrialization of DSSCs is limited by shortcomings of Pt CEs such as being expensive, and weak corrosion resistance in electrolytes. Reported in this paper is two simple approaches to Pt-free Cu_1.8S_1-xSe_x CEs. Nanocrystalline Cu_1.8S_1-xSe_x CEs were fabricated via two processes, that is, a solvothermal process to Cu_1.8S_1-xSe_x powder followed by CE fabrication, and a solvothermal process and CE fabrication to Cu_1.8S films followed by selenylation to Cu_1.8S_1-xSe_x CEs. Photoelectric conversion efficiencies (PCE) of 4.02% and 4.16% were achieved respectively by the as-fabricated Cu_1.8S_1-xSe_x CEs. Compared with the cells with Cu_1.8S CEs fabricated by the same processes, increases of 19% and 45% were achieved, respectively. The PCE improvement comes from the enhancement of charge transfer at the CE/electrolyte interface induced by the selenylation of the CEs.

Rapid host strain improvement by in vivo rearrangement of a synthetic yeast chromosome

Synthetic biology tools, such as modular parts and combinatorial DNA assembly, are routinely used to optimise the productivity of heterologous metabolic pathways for biosynthesis or substrate utilisation, yet it is well established that host strain background is just as important for determining productivity. Here we report that in vivo combinatorial genomic rearrangement of Saccharomyces cerevisiae yeast with a synthetic chromosome V can rapidly generate new, improved host strains with genetic backgrounds favourable to diverse heterologous pathways, including those for violacein and penicillin biosynthesis and for xylose utilisation. We show how the modular rearrangement of synthetic chromosomes by SCRaMbLE can be easily determined using long-read nanopore sequencing and we explore experimental conditions that optimise diversification and screening. This synthetic genome approach to metabolic engineering provides productivity improvements in a fast, simple and accessible way, making it a valuable addition to existing strain improvement techniques.

The Sc2.0 project has built the Synthetic Chromosome Rearrangement and Modification by LoxP-mediated Evolution (SCRaMbLE) system into their synthetic chromosomes. Here the authors use SCRaMbLE to rapidly develop, diversify and screen strains for diverse production and growth characteristics.

Correlations among copeptin, ischemia-modified albumin, and the extent of myocardial injury in patients with acute carbon monoxide poisoning

This study evaluated the relationships among copeptin, ischemia-modified albumin (IMA), and extent of myocardial injury in patients with acute carbon monoxide poisoning (ACOP). A total of 110 patients with different degrees of ACOP were selected as the poisoning group, and 30 healthy individuals as the control group. The levels of troponin I (cTnI), IMA, and copeptin were detected. Based on the presence of complications, the patients were assigned to the complication (26 patients) or non-complication (84 patients) group. Levels of cTnI, IMA, and copeptin were compared among the control, complication, and non-complication groups. Compared with the control group, in the 2 h after admission, the IMA levels decreased and copeptin levels increased in the poisoning group; these changes were more significant in patients with severe ACOP than in those with mild ACOP, and the difference was statistically significant (P < 0.05). There were no differences in the IMA and copeptin levels between the groups 7 days after admission; the cTnI levels increased more significantly in patients with severe ACOP than in patients with mild and moderate ACOP, and the differences were statistically significant (P < 0.05). In the complication group, at 7 days after admission, the IMA levels decreased whereas the copeptin and cTnI levels were significantly higher than in the non-complication group, with a statistically significant difference (P < 0.05). IMA was negatively correlated with copeptin. IMA and copeptin detection is clinically useful in the early diagnosis and prognosis of ACOP-related myocardial injury and in guiding early clinical drug application.

[Immune response elicited by the recombinant protein and plasmid DNA of complex antigen ROP2-SAG1 from Toxoplasma gondii]

OBJECTIVE

To study the immune response elicited by the recombinant protein vaccine and DNA vaccine of the complex antigen ROP2-SAG1 from Toxoplasma gondii.

METHODS

Sixty female BALB/c mice were randomly divided into 4 groups (15 per group). Mice in rROP2-SAGI group were immunized subcutaneously with 2.5 microg rROP2-SAG1 protein formulated in Freund's adjuvant. Mice in control group received only adjuvant emulsified with normal saline. Mice in recombinant plasmid pcROP2-SAG1 and control plasmid pcDNA3.1 groups were each injected intramuscularly with 100 microg of pcROP2-SAG1 and pcDNA3.1, respectively. All the mice received three immunizations at 2-week intervals. Serum samples were collected at 25, 45, and 70 days after immunization for determining antibody IgG, and at 2 weeks after the last immunization IgG1 and IgG2a were detected all by ELISA. Cell counting kit-8 (CCK-8) was used to determine the splenocyte proliferation, and the supernatant of cultured splenocytes was collected for the detection of IFN-gamma by ELISA.

RESULTS

The level of IgG continued to rise in rROP2-SAG1 group after immunization, and similarly in pcROP2-SAG1 group. At 2 weeks after the last immunization, level of IgG1 (1.538 +/- 0.183) was higher than that of IgG2a (0.618 +/- 0.122) (P < 0.05) in rROP2-SAG1 group. Whereas no significant difference between IgG1 (1.107 +/- 0.137) and IgG2a (0.830 +/- 0.185) was observed in pcROP2-SAG1 group (P > 0.05). Compared with the pcROP2-SAG1 group (A450 = 0.123 +/- 0.018), more significant proliferation response of splenocytes was observed in rROP2-SAG1 group (0.348 +/- 0.042) (P < 0.05). There was no significant difference (P > 0.05) of IFN-gamma and IL-2 in the supematant of cultured splenocytes between the groups of rROP2-SAG1 and pcROP2-SAG1.

CONCLUSION

The antibody level and splenocyte proliferation have been significantly higher in mice immunized with recombinant protein rROP2-SAG1 than those with recombinant plasmid pcROP2-SAG1.

Double spectral theorem and two type magnitude-squared coherence functions

Studying frequency domain representation for the coherence between two signals is an important basic theoretical problem in the fundamental theories of signal processing. However, the old magnitude-squared coherence function (OMSCF) has been proved identical to 1, so that to cannot be used to extract any coherence information. Here, we will prove a core theorem in frequency domain coherence theories in signal processing, called as the double spectral theorem (DST). Based on the theorem, we presented the two types of new magnitude-squared coherence functions (MSCFs), called as the same type magnitude-squared coherence function (SMSCF) and the difference magnitude-squared coherence function (DMSCF) respectively, which were mathematically derived from DST and the conditions that they are equal to 1 or 0 can be theoretically derived from DST. Here, we further demonstrated that SMSCF and DMSCF could be used to exactly extract the coherence between two signals by each component.

Using independent component analysis to research heart rate variability

Independent component analysis (ICA) and neural networks were used to extract sub-signals of heart rate variability (HRV). Electrocardiogram (ECG) recording was consisted of six minutes when the volunteer was lying and another six minutes when the volunteer was standing. HRV was extracted from ECG. According to time-delay, HRV was divided into five groups as mixed signals. ICA and neural networks reconstructed five signals into two groups. Results showed that one group signal component centralized in low frequency (called IC1); the other did in high frequency (called IC2). The power of IC1 was significantly increased (P<0.05) and the ratio of IC1 to total power was significantly increased (P<0.01) from lying to standing. Comparing the two postural results, it shows that IC1 may express sympathetic activity, and IC2 represents parasympathetic activity. Sympathetic and parasympathetic nervous function can be evaluated respectively and quantificationally by data and graphs from the two decomposed components. Key word: Neural networks, Independent component analysis, Heart rate variability, Autonomic nervous system.

Association of beta-adrenoceptor single nucleotide polymorphisms with resting heart rate

The association of beta-adrenoceptor (B-AR, including three subgroups: Beta1, Beta2 and Beta3) single nucleotide polymorphisms (SNP) with resting heart rate (RHR) were analyzed. RHR of 107 healthy subjects in the supine were detected by computerized system for 8 minutes. Genotyping SNPs of S/G49 and R/G389 of Beta1-AR and W/R64 of Beta3-AR in these subjects were by means of PCR-restriction fragment length polymorphism (PCR-RFLP) technique. Genotyping SNPs of R/G16 and Q/E27 of Beta1-adrenoceptor in these subjects were by means of allele specific primer-PCR (ASP-PCR) technique. It was found that there was no significant difference among RHRs corresponding above SNPs of B-AR, but the SNP of R/G389 of Beta1-AR, in which there was significant difference among RHRs (P<0.05). Either in the female individuals or in the male, those with Beta1-AR G/G389 genotype had the highest RHR. The females with R/R389 genotype had the lowest RHR, however, the males with R/G389 genotype had the lowest RHR. The RHR was not only associated with R/G389 polymorphism of Beta1-adrenoceptor gene significantly, but also was associated with gender in Chinese.

[The effects of jiexinkang on the apoptosis of leukemic cells]

The effects of Chinese medicine jiexinkang(JXK) on apoptosis of leukemic cells were studied by morphology approach and electrophoresis of DNA fragments.

RESULTS

1. The apoptotic cells and apoptotic bodies were found by electrical microscopy and the typical ladders of DNA fragments were detected by electrophoresis. 2. JXK induced apoptosis of leukemic cells(HL-60 and K562) in a certain range of concentration and at appropriate time. The time to K562 cell apoptosis was longer than that of HL-60 and its dosage was larger than that of HL-60.

CONCLUSION

HL-60 and K562 leukemic cell apoptosis may be induced by JXK and there is correlation between dose and time. The study provides experimental evidences for the clinical treatment of leukemia.

[Levels of plasma TF and TFPI activities in patients with acute leukemia]

OBJECTIVE

To investigate the changes of plasma tissue factor(TF) and tissue factor pathway inhibitor(TFPI) activities in the patients with acute leukemia.

METHODS

TF and TFPI activities were measured by using chromogenic assays.

RESULTS

Plasma TF activity in the patients with acute leukemia was higher and TFPI activity was lower than those in normal(P < 0.01). In 7 patients who underwent the first chemotherapy, the plasma TF activity was decreased after chemotherapy(P < 0.01), while TFPI activity increased(P < 0.05).

CONCLUSION

The unbalance between plasma TF and TFPI activities contributes to the coagulant disorders in acute leukemia.

[Clinical significance of P-glycoprotein and CD34 expression of acute leukemia]

The expression of P-glycoprotein(P-170) and CD34 was detected in the bone marrow mononuclear cells of 30 patients with acute leukemia by immunocytochemical technique using JSB-1 and Tük 3 monoclonal antibody. The results were that expression of P-170 and CD34 had no significant difference between acute nonlymphoblastic leukemia and acute lymphoblastic leukemia(P > 0.05). The clinical therapeutic effect was poor in P-170 or CD34 positive patients and had significant difference compared with those negative patients(P < 0.05). Judgments of therapeutic effect for acute leukemia can be improved by detecting the expression of P-170 and CD34 simultaneously.

[Immunohistochemical and ultrastructural study on neoplastic endocrine cells and Paneth's cells in gastric carcinoma]

One hundred and twenty-eight cases of gastric carcinoma were examined with immunohistochemical technic for carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), serotonin, gastrin and lysozyme. CEA were observed in 105 cases. Twenty-four cases were positive for HCG, 53 cases for serotonin, 31 cases for gastrin, 89 cases for lysozyme. Sixty-nine cases exhibited more than two hormones or one hormone and lysozyme simultaneously in different cells of the same tumor. Ultrastructurally, sometimes three types of secretory granules were noticed. The electron dense granules in the lysozyme-containing tumor cells were similar to those of Paneth's cells in intestinal metaplasia. The positive rates of the above three hormones, lysozyme and multi-marker expression in diffuse type carcinoma were higher than those in intestinal type, and 42/44 cases of the diffuse type carcinoma were histologically undifferentiated carcinomas or signet-ring cell carcinomas. Lymph node metastasis occurred more frequently in those carcinomas with hormone or lysozyme positivity. These findings suggest that these neoplastic endocrine cells and Paneth's cells have originated from multipotential differentiation of neoplastic stem cells in the stomach, reflecting the state of the gene activity in the tumor cells.

Efficacy of experimental Newcastle disease water-in-oil oil-emulsion vaccines formulated from squalane and squalene

Water-in-oil inactivated Newcastle disease oil-emulsion vaccines were formulated with the terpene oils squalane or squalene, or mixtures thereof, and injected into 4-week-old broilers. Vaccine efficacy based on hemagglutination-inhibition (HI) titers was comparable to that of control mineral oil vaccines. Tissue reaction to intramuscular injection of the terpene oil emulsion vaccines was greatly reduced 3 weeks post-vaccination compared with that of mineral oil-based vaccine. Viscosity of the terpene oil vaccines was satisfactory but increased three to four times that of mineral oil vaccine when the antigen phase volume increased from 5% to 20%.

Immune response to oil-emulsion vaccines with single or mixed antigens of Newcastle disease, avian influenza, and infectious bronchitis

Inactivated Newcastle disease virus (NDV), avian influenza virus (AIV), and infectious bronchitis virus (IBV) antigens were evaluated for immunological efficacy in monovalent and polyvalent vaccines. Vaccinated broilers were bled for hemagglutination-inhibition (HI) tests at 1- or 2-week intervals. Half of the chickens were challenged with the Largo isolate of velogenic viscerotropic (VV) NDV at 8 weeks post-vaccination, and the remainder were challenged with the Massachusetts 41 strain IBV at 9 weeks post-vaccination. Newcastle disease HI titers were reduced significantly (P less than 0.05) from those of monovalent control vaccine groups when IBV antigen was emulsified in mixtures with low (1-3x) concentrated NDV or NDV and AIV antigens. Avian influenza HI titers were significantly (P less than 0.05) lower than those of the control monovalent groups when highly concentrated NDV was part of the polyvalent vaccine. Infectious bronchitis HI titers were higher than those of control monovalent groups in 13 of 15 vaccine groups when IBV antigen was in polyvalent formulations. VV NDV challenge killed all non-NDV vaccinates and induced increased HI titers in NDV vaccinates but no morbidity or mortality. Sixty of 80 IBV vaccinates experienced a fourfold or greater HI titer increase following challenge. All non-IBV vaccinates seroconverted at 1 week post-challenge.

Myocardial effects of calcium cyclamate in the BIO F1D Alexander Syrian golden hamster

In a subchronic 90-day oral toxicity study, 5 groups (20 males, 20 females each) of F2-descendants of BIO F1D Alexander hamsters received 0, 275, 550, 1,100 and 2,200 mg/kg b.w./day doses, respectively, of calcium cyclamate in the drinking water. These doses caused no adverse health effects in any treated animal and the multifocal myocardial calcifications, detectable at a 100% incidence in the male and female control hamsters (20 males, 20 females), were not exacerbated by the sweetener. Instead, the myocardial lesions exhibited a striking negative dose-response relationship with a 0% incidence in the males and a 5% incidence in the female hamsters of the highest dose group.