Huntington disease-like 2: insight into neurodegeneration from an African disease

Huntington disease (HD)-like 2 (HDL2) is a rare genetic disease caused by an expanded trinucleotide repeat in the JPH3 gene (encoding junctophilin 3) that shows remarkable clinical similarity to HD. To date, HDL2 has been reported only in patients with definite or probable African ancestry. A single haplotype background is shared by patients with HDL2 from different populations, supporting a common African origin for the expansion mutation. Nevertheless, outside South Africa, reports of patients with HDL2 in Africa are scarce, probably owing to limited clinical services across the continent. Systematic comparisons of HDL2 and HD have revealed closely overlapping motor, cognitive and psychiatric features and similar patterns of cerebral and striatal atrophy. The pathogenesis of HDL2 remains unclear but it is proposed to occur through several mechanisms, including loss of protein function and RNA and/or protein toxicity. This Review summarizes our current knowledge of this African-specific HD phenocopy and highlights key areas of overlap between HDL2 and HD. Given the aforementioned similarities in clinical phenotype and pathology, an improved understanding of HDL2 could provide novel insights into HD and other neurodegenerative and/or trinucleotide repeat expansion disorders.

Bidirectional Transcription at the PPP2R2B Gene Locus in Spinocerebellar Ataxia Type 12

BACKGROUND

Spinocerebellar ataxia type 12 (SCA12) is a neurodegenerative disease caused by expansion of a CAG repeat in the PPP2R2B gene.

OBJECTIVE

In this study, we tested the hypothesis that the PPP2R2B antisense (PPP2R2B-AS1) transcript containing a CUG repeat is expressed and contributes to SCA12 pathogenesis.

METHODS

Expression of PPP2R2B-AS1 transcript was detected in SCA12 human induced pluripotent stem cells (iPSCs), iPSC-derived NGN2 neurons, and SCA12 knock-in mouse brains using strand-specific reverse transcription polymerase chain reaction. The tendency of expanded PPP2R2B-AS1 (expPPP2R2B-AS1) RNA to form foci, a marker of toxic processes involving mutant RNAs, was examined in SCA12 cell models by fluorescence in situ hybridization. The apoptotic effect of expPPP2R2B-AS1 transcripts on SK-N-MC neuroblastoma cells was evaluated by caspase 3/7 activity. Western blot was used to examine the expression of repeat associated non-ATG-initiated translation of expPPP2R2B-AS1 transcript in SK-N-MC cells.

RESULTS

The repeat region in the PPP2R2B gene locus is bidirectionally transcribed in SCA12 iPSCs, iPSC-derived NGN2 neurons, and SCA12 mouse brains. Transfected expPPP2R2B-AS1 transcripts induce apoptosis in SK-N-MC cells, and the apoptotic effect may be mediated, at least in part, by the RNA secondary structure. The expPPP2R2B-AS1 transcripts form CUG RNA foci in SK-N-MC cells. expPPP2R2B-AS1 transcript is translated in the alanine open reading frame (ORF) via repeat-associated non-ATG translation, which is diminished by single-nucleotide interruptions within the CUG repeat and MBNL1 overexpression.

CONCLUSIONS

These findings suggest that PPP2R2B-AS1 contributes to SCA12 pathogenesis and may therefore provide a novel therapeutic target for the disease. © 2023 International Parkinson and Movement Disorder Society.

Identification of a specific APOE transcript and functional elements associated with Alzheimer's disease

INTRODUCTION

The APOE gene is the strongest genetic risk factor for late-onset Alzheimer's Disease (LOAD). However, the gene regulatory mechanisms at this locus have not been fully characterized.

METHODS

To identify novel AD-linked functional elements within the APOE locus, we integrated SNP variants with RNA-seq, DNA methylation, and ChIP-seq data from human postmortem brains.

RESULTS

We identified an AD-linked APOE transcript (jxn1.2.2) observed in the dorsolateral prefrontal cortex (DLPFC). The APOE jxn1.2.2 transcript is associated with brain neuropathological features in DLPFC. We prioritized an independent functional SNP, rs157580, significantly associated with jxn1.2.2 transcript abundance and DNA methylation levels. rs157580 is located within active chromatin regions and predicted to affect brain-related transcriptional factors binding affinity. rs157580 shared the effects on the jxn1.2.2 transcript between European and African ethnic groups.

DISCUSSION

The novel APOE functional elements provide potential therapeutic targets with mechanistic insight into the disease's etiology.

[The effect of platelet infusion on the repair of bone marrow hematopoietic niche damage in mice induced by (60)Co radiation and hematopoietic reconstruction after bone marrow transplantation]

Objective: To observe the effect of platelets on hematopoietic stem cell (HSCs) implantation in mice with radiation-induced bone marrow injury and bone marrow transplantation models. Methods: ①Male C57BL/6 mice were divided into a single irradiation group and a radiation infusion group after receiving (60)Co semimyeloablative irradiation for 18-10 weeks. The irradiation infusion group received 1×10(8) platelets expressing GFP fluorescent protein. ② The allogeneic bone marrow transplantation model was established. The experimental groups included the simple transplantation group (BMT) and the transplantation infusion group (BMT+PLT). The BMT group was infused through the tail vein only 5 × 10(6) bone marrow cells, the BMT+PLT group needs to be infused with bone marrow cells at the same time 1× 10(8) platelets. ③ Test indicators included peripheral blood cell and bone marrow cell counts, flow cytometry to detect the proportion of hematopoietic stem cell (HSC) and hematopoietic progenitor cells, bone marrow cell proliferation and apoptosis, and pathological observation of vascular niche damage and repair. Results: ①On the 3rd, 7th, 14(th), and 21st days after irradiation, the bone marrow cell count of the infusion group was higher than that in the single irradiation group (P<0.05), and the peripheral blood cell count was also higher. A statistically significant difference was found between the white blood cell count on the 21st day and the platelet count on the 7th day (P<0.05). In the observation cycle, the percentage of bone marrow cell proliferation in the infusion group was higher, while the percentage of apoptosis was lower. ② The results of bone tissue immunofluorescence after irradiation showed that the continuity of hematopoietic niche with red fluorescence was better in the irradiation infusion group. ③The chimerism percentage in the BMT+PLT group was always higher than that in the BMT group after transplantation.④ The BMT+PLT group had higher bone marrow cell count and percentage of bone marrow cell proliferation on the 7th and 28th day after transplantation than that in the BMT group, and the percentage of bone marrow cell apoptosis on the 14th day was lower than that in the BMT group (P<0.05). After the 14th day, the percentage of stem progenitor cells in the bone marrow cells of mice was higher than that in the BMT group (P<0.05). ⑤The immunohistochemical results of bone marrow tissue showed that the continuity of vascular endothelium in the BMT+PLT group was better than that in the BMT group. Conclusion: Platelet transfusion can alleviate the injury of vascular niche, promotes HSC homing, and is beneficial to hematopoietic reconstruction.

Bidirectional transcription at the PPP2R2B gene locus in spinocerebellar ataxia type 12

OBJECTIVE

Spinocerebellar ataxia type 12 (SCA12) is a neurodegenerative disease caused by expansion of a CAG repeat in the PPP2R2B gene . Here we tested the hypothesis that the PPP2R2B antisense ( PPP2R2B-AS1 ) transcript containing a CUG repeat is expressed and contributes to SCA12 pathogenesis.

METHODS

Expression of PPP2R2B-AS1 transcript was detected in SCA12 human induced pluripotent stem cells (iPSCs), iPSC-derived NGN2 neurons, and SCA12 knock-in mouse brains using strand-specific RT-PCR (SS-RT-PCR). The tendency of expanded PPP2R2B-AS1 ( expPPP2R2B-AS1 ) RNA to form foci, a marker of toxic processes involving mutant RNAs, was examined in SCA12 cell models by fluorescence in situ hybridization. The toxic effect of expPPP2R2B-AS1 transcripts on SK-N-MC neuroblastoma cells was evaluated by caspase 3/7 activity. Western blot was used to examine the expression of repeat associated non-ATG-initiated (RAN) translation of expPPP2R2B-AS1 transcript in SK-N-MC cells.

RESULTS

The repeat region in PPP2R2B gene locus is bidirectionally transcribed in SCA12 iPSCs, iPSC-derived NGN2 neurons, and SCA12 mouse brains. Transfected expPPP2R2B-AS1 transcripts are toxic to SK-N-MC cells, and the toxicity may be mediated, at least in part, by the RNA secondary structure. The expPPP2R2B-AS1 transcripts form CUG RNA foci in SK-N-MC cells. expPPP2R2B-AS1 transcript is translated in the Alanine ORF via repeat-associated non-ATG (RAN) translation, which is diminished by single nucleotide interruptions within the CUG repeat, and MBNL1 overexpression.

INTERPRETATION

These findings suggest that PPP2R2B-AS1 contributes to SCA12 pathogenesis, and may therefore provide a novel therapeutic target for the disease.

Phenotype and genetic characteristics in 20 Chinese patients with 46,XY disorders of sex development

PURPOSE

46,XY disorders of sex development (DSD) is the most complicated and common type of DSD. To date, more than 30 genes have been identified associated with 46,XY DSD. However, the mutation spectrum of 46,XY DSD is incomplete owing to the high genetic and clinical heterogeneity. This study aims to provide clinical and mutational characteristics of 18 Chinese patients with 46,XY DSD.

METHODS

A total of 20 unrelated individuals with 46,XY DSD were recruited. Whole-exome sequencing (WES) or custom-panel sequencing combined Sanger sequencing were performed to detect the pathogenic mutations. The pathogenicity of the variant was assessed according to the American College of Medical Genetics and Genomics (ACMG) guidance and technical standards recommended by the ACMG and the Clinical Genome Resource (ClinGen).

RESULTS

Six patients harbored NR5A1 mutations; two patients harbored NR0B1 mutations; six patients harbored SRD5A2 mutations; six patients harbored AR mutations. Six novel genetic variants were identified involved in three genes (NR5A1, NR0B1, and AR).

CONCLUSION

We determined the genetic etiology for all enrolled patients. Our study expanded the mutation spectrum of 46,XY DSD and provided diagnostic evidence for patients with the same mutation in the future.

RNA Toxicity and Perturbation of rRNA Processing in Spinocerebellar Ataxia Type 2

BACKGROUND

Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disease caused by expansion of a CAG repeat in Ataxin-2 (ATXN2) gene. The mutant ATXN2 protein with a polyglutamine tract is known to be toxic and contributes to the SCA2 pathogenesis.

OBJECTIVE

Here, we tested the hypothesis that the mutant ATXN2 transcript with an expanded CAG repeat (expATXN2) is also toxic and contributes to SCA2 pathogenesis.

METHODS

The toxic effect of expATXN2 transcripts on SK-N-MC neuroblastoma cells and primary mouse cortical neurons was evaluated by caspase 3/7 activity and nuclear condensation assay, respectively. RNA immunoprecipitation assay was performed to identify RNA binding proteins (RBPs) that bind to expATXN2 RNA. Quantitative PCR was used to examine if ribosomal RNA (rRNA) processing is disrupted in SCA2 and Huntington's disease (HD) human brain tissue.

RESULTS

expATXN2 RNA induces neuronal cell death, and aberrantly interacts with RBPs involved in RNA metabolism. One of the RBPs, transducin β-like protein 3 (TBL3), involved in rRNA processing, binds to both expATXN2 and expanded huntingtin (expHTT) RNA in vitro. rRNA processing is disrupted in both SCA2 and HD human brain tissue.

CONCLUSION

These findings provide the first evidence of a contributory role of expATXN2 transcripts in SCA2 pathogenesis, and further support the role of expHTT transcripts in HD pathogenesis. The disruption of rRNA processing, mediated by aberrant interaction of RBPs with expATXN2 and expHTT transcripts, suggest a point of convergence in the pathogeneses of repeat expansion diseases with potential therapeutic implications. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Use of single guided Cas9 nickase to facilitate precise and efficient genome editing in human iPSCs

Cas9 nucleases permit rapid and efficient generation of gene-edited cell lines. However, in typical protocols, mutations are intentionally introduced into the donor template to avoid the cleavage of donor template or re-cleavage of the successfully edited allele, compromising the fidelity of the isogenic lines generated. In addition, the double-stranded breaks (DSBs) used for editing can introduce undesirable "on-target" indels within the second allele of successfully modified cells via non-homologous end joining (NHEJ). To address these problems, we present an optimized protocol for precise genome editing in human iPSCs that employs (1) single guided Cas9 nickase to generate single-stranded breaks (SSBs), (2) transient overexpression of BCL-XL to enhance survival post electroporation, and (3) the PiggyBac transposon system for seamless removal of dual selection markers. We have used this method to modify the length of the CAG repeat contained in exon 7 of PPP2R2B. When longer than 43 triplets, this repeat causes the neurodegenerative disorder spinocerebellar ataxia type 12 (SCA12); our goal was to seamlessly introduce the SCA12 mutation into a human control iPSC line. With our protocol, ~ 15% of iPSC clones selected had the desired gene editing without "on target" indels or off-target changes, and without the deliberate introduction of mutations via the donor template. This method will allow for the precise and efficient editing of human iPSCs for disease modeling and other purposes.

Generation of a human induced pluripotent stem cell line JHUi003-A with homozygous mutation for spinocerebellar ataxia type 12 using genome editing

Spinocerebellar ataxia type 12 (SCA12) is caused by a CAG expansion mutation in PPP2R2B, a gene encoding a brain-specific regulatory unit of protein phosphatase 2A (PP2A); while normal alleles carry 4 to 31 triplets, the disease alleles carry 43 to 78 triplets. Here, by CRISPR/Cas9 genome editing, we have generated a human homozygous SCA12 iPSC line with 69 and 72 triplets for each allele. The homozygous SCA12 iPSCs have normal karyotype, express pluripotency markers and are able to differentiate into the three germ layers.

[Hepatic metastases after cervical cancer surgery: clinical analysis of 13 cases]

Objective: To investigate the clinical characteristics of patients with hepatic metastasis after cervical cancer operation, and analyze the risk factors and prognostic factors of hepatic metastasis. Methods: A total of 1 312 patients with stage Ⅰa2-Ⅱb2 cervical cancer received radical surgery from January 2013 to January 2016 in the First Affiliated Hospital of Zhengzhou University were collected, of which 13 cases (0.99%, 13/1 312) had hepatic metastasis after operation. A retrospective analysis was conducted on clinical features of patients with hepatic metastasis after cervical cancer operation. T-test, chi-square test, rank sum test and logistic regression were used to analyze the risk factors of hepatic metastasis after surgery of cervical cancer operation. Kaplan-Meier method was used for survival analysis. Log-rank test was used for screening of prognostic factors in patients with postoperative hepatic metastasis. Results: (1) Clinical features: there were 3 cases of simple hepatic metastasis without obvious clinical symptoms, 2 patients with perihepatic lymph node metastasis showed only low back pain, 8 patients with multiple extrahepatic metastases, and their clinical symptoms were related to the site of metastasis. Five cases out of 9 (5/9) with liver metastasis had abnormal tumor marker results. The abnormal kinds of tumor markers were mainly carcinoembryonic antigen (CEA), CA(125), CA(199), and CA(72-4). The interval time of hepatic metastasis after operation was 2-22 months. (2) Analysis of risk factors for hepatic metastasis: univariate analysis showed that lymph node metastasis, histological type, infiltration depth, and lymph-vascular space invasionwere associated with hepatic metastasis after cervical cancer surgery (P<0.05).Multivariate analysis showed that lymph node metastasis and small cell carcinoma were independent risk factors for postoperative hepatic metastasis (P<0.05). (3) Prognostic factors in patients with hepatic metastasis:among 13 patients with postoperative hepatic metastases from cervical cancer, 9 died during the follow-up period and 4 survived. The median total survival time after hepatic metastases was 7 months (range 3-32 months). Univariate analysis showed that multiple extrahepatic metastases and treatment after hepatic metastasis had significant effects on the prognosis of patients with hepatic metastasis after cervical cancer operation (P<0.05). Conclusions: The interval of hepatic metastasis after surgery for cervical cancer operation is within 2 years. Patients with lymph node metastasis and small cell carcinoma are more prone to postoperative hepatic metastasis. The prognosis of patients with extrahepatic multiple metastases is poor, and individualized treatment should be carried out after comprehensive analysis for patients with hepatic metastasis after cervical cancer operation.

Effects of Senior Simulation Suit Programme on nursing students' attitudes towards older adults: A randomized controlled trial

BACKGROUND

As populations age worldwide, nursing educational institutions need to train nurses not only to provide health care services specific to the elderly, but also to have a positive attitude as they work. The present study aimed to investigate the efficacy of a Senior Simulation Suit Programme (SSSP). The SSSP, which focused on mimicking the physiological experiences of an 80 year-old person, was hypothesized to increase the wearer's positive attitude towards older adult care.

METHODS

A single-blinded, randomized controlled trial was used to evaluate the efficacies of SSSP. One hundred and thirty-nine (139) nursing students were randomly assigned to either SSSP group (n = 69) or to a control group (n = 70) with "placebo clothing", i.e. clothing that mimicked old age but did not actually impair faculties. Two instruments-Kogan Attitudes Towards Old People Scale (KAOP) and a 1-item scale on Willingness To Care for Older People Scale (WCOP)-were used for data collection at baseline and at completion of SSSP. A Chinese version of Palmore's Facts Aging Quiz (C-FAQ) was used to assess nursing students' knowledge about adult care, and a questionnaire was developed to collect demographic information at baseline.

RESULTS

No significant difference between the two groups was found. A significant increase of positive attitudes and of willingness to serve older adults was found in both the control group and the group wearing SSSP.

CONCLUSION

Both the SSSP and control intervention could improve the attitudes of nursing students towards older adult care. This study suggests that wearing whatever the nursing students associate with being old, will improve their attitude towards older adult care.

[Color stability of computer aided design and computer aided manufacture composite ceramic/resin cements after accelerated ageing]

Objective: To investigate the color stability of computer aided design and computer aided manufacture (CAD/CAM) composite ceramic/resin cements after accelerated ageing. Methods: Twelve groups (ten samples each group) were used as experimental groups, which were composed of CAD/CAM composite ceramic of three kinds of thickness (0.50, 0.75, 1.00 mm) (Lava Ultimate) associated with resin cements (Variolink N) of four colors (A1, A3, T, BL1). Another three groups of CAD/CAM composite ceramic/resin cements of three different kinds of thickness (0.50, 0.75, 1.00 mm) were used as control groups (ten samples each group). All samples were put into the xenon lamp ageing instrument to implement accelerated ageing. Spectrophotometers were used to measure the lightness (L(*)), red green color value (a(*)) and blue yellow color value (b(*)) of all samples before and after accelerated ageing process, and the changes of color variation (ΔE) was calculated. The effect of composite ceramic thickness and resin cement color on the changes of color variation (ΔE) before and after the ageing of CAD/CAM composite ceramic/resin cement and whether there was an interaction between them were tested by two-way ANOVA. Results: Before and after accelerated ageing, the ΔE of CAD/CAM composite ceramic/resin cements were <3.3. Two-way ANOVA showed that the thickness of CAD/CAM composite ceramics had an effect on ΔE (F=27.025, P<0.001), and the color of resin cement also had an effect on ΔE (F=15.606, P<0.001), but there was no interaction between them (F=0.534, P=0.829). Conclusions: The thickness of CAD/CAM composite ceramics and the color of resin cements could both affect the color stability of composite ceramic/resin cements combination. However, the resulted color change is within the clinically acceptable range.

Effect of different time of ultrasound treatment on physicochemical, thermal, and antioxidant properties of chicken plasma protein

The aim of present study was to investigate the effect of different times (5 min (UCPP-5), 10 min (UCPP-10), 20 min (UCPP-20), and 30 min (UCPP-30)) of ultrasound treatment on physicochemical, thermal, and antioxidant properties of chicken plasma protein (CPP). UCPP-20 had the highest fluorescence intensity and the lowest particle size. However, no major changes in the subunit compositions and the secondary structure of UCPPs were presented in SDS-PAGE and circular dichroism. The surface hydrophobicity and sulfhydryl content of UCPPs increased significantly (P < 0.05) as compared to those of CPP. With the increasing time of ultrasound treatment, there were more and deeper holes on the protein surfaces. Furthermore, protein modification by ultrasound could improve the thermal properties of UCPPs. Additionally, UCPPs showed a significant increase in antioxidant properties over CPP, especially UCPP-20. These observations indicated that ultrasound treatment was necessary for modification of CPP to meet the requirements for food processing.

[Comparative study of three-dimensional versus two-dimensional laparoscopic C1 radical hysterectomy for cervical cancer]

Objective: To compare the clinical effects and the subjective perception of surgeons with three-dimensional (3D) and two-dimensional (2D) laparoscopic C1 radical hysterectomy surgeries for cervical cancer. Methods: The retrospective cohort study was conducted. The clinicopathological data of 101 patients with cervical cancer who received C1 laparoscopic radical hysterectomy (C1-LRH) surgery from June 2015 to August 2017 were collected. Of all patients, 42 cases undergoing 3D laparoscopic surgery and 59 cases undergoing 2D laparoscopic surgery were respectively allocated into the C1-3DLRH group or C1-2DLRH group. The clinical effect and the subjective perception of surgeons were compared between the two groups. Results: (1) There was no significant difference between the C1-3DLRH group and C1-2DLRH group in terms of age, body mass index (BMI), International Federation of Gynecology and Obstetrics (FIGO) stage, pathologic type, etc. (all P>0.05). Compared with C1-2DLRH group, the operation time was significantly shortened [(192±54) vs (221±54) minutes, P<0.01], blood loss was significantly less [(102±88) vs (167±117) ml, P<0.01], and the success rate of inferior hypogastric plexus (IHP) bladder branch preservation was significantly increased [86% (36/42) vs 66% (39/59), P<0.05] in C1-3DLRH group. There were no significant difference in the number of lymph nodes, the incidence of operative complications, the infection rate, the time of catheterization and the length of hospitalization between the two groups (all P>0.05). The long-term bladder function was evaluated at the twelfth month after operation, 39 patients in the C1-3DLRH group and 53 patients in the C1-2DLRH group were completed the survey. The results showed that 13% (5/39) of the patients in the C1-3DLRH group had long-term bladder dysfunction, which was lower than that 21% (11/53) of the C1-2DLRH group, but there was no significant difference between the two groups (χ(2)=0.980, P=0.322). (2) A total of 251 laparoscopic surgeons questionnaires were eligible. The incidence of side effects in the first and second generation of 3D and 2D laparoscopic surgeons was 20.4% (10/49), 6.9% (6/87) and 3.5% (4/115), respectively. The incidence of side effects in the first generation of 3D laparoscopic surgeons was higher than that in the second generation of 3D (χ(2)=5.463, P=0.019) and 2D laparoscopic surgeons (χ(2)=12.475, P<0.01). There was no difference between the second generation of 3D and 2D laparoscopic surgeons (χ(2)=1.208, P=0.272). Conclusions: 3D laparoscopy is advantageous to the preservation of autonomic nerve in C1-LRH operation and may improve the quality of operation compared with 2D laparoscopy. The second generation of 3D laparoscopic device might overcome the side effects of the surgeons.

Very high external quantum efficiency and wall-plug efficiency 527 nm InGaN green LEDs by MOCVD

We demonstrate very high luminous efficacy InGaN-based green light-emitting diodes (LEDs) grown on c-plane patterned sapphire substrates (PSS) using metal organic chemical vapor deposition (MOCVD). The 527 nm green LEDs show a peak external quantum efficiency (EQE) of 53.3%, a peak wall-plug efficiency (WPE) of 54.1% and a peak luminous efficacy of 329 lm/W, respectively. A high EQE of 38.4%, a WPE of 32.1% and a very low forward voltage of 2.86 V were obtained at a typical working current density of 20 A/cm². By operating low cost green LEDs at a low current density, our devices (0.5 mm²) demonstrating an EQE and a WPE higher than 50% and an efficacy of 259 lm/W at 4 A/cm² with an output power of 24 mW. High crystal quality of the InGaN/GaN MQWs was characterized by X-ray diffraction (XRD) and the advantage of the epitaxy design was investigated by APSYS software simulation. These results provide a simple way to achieve very high efficiency InGaN green LEDs.

Bioaugmented soil aquifer treatment for P-nitrophenol removal in wastewater unique for cold regions

P-nitrophenol (PNP) is a toxic and recalcitrant organic pollutant and a usual intermediate in the production of fine chemicals, which has posed a significant threat to subsurface environment safety. Soil aquifer treatment (SAT) is a promising method to remove and remediate contamination in vadose zone with low cost and high efficiency. However, there are still research gaps for the treatment of recalcitrant contaminants by SAT in cold regions, such as un-robust indigenous microbes and low temperature constraint in vadose zone. The bioaugmentation technology was first introduced into SAT in order to enhance the removal ability of PNP by SAT operated in cold regions in this study. A high-efficiency PNP-degrading bacterium was successfully isolated, which can efficiently degrade PNP below 200 mg L^-1 with a degradation rate above 99% at 15 °C close to the real subsurface temperature in cold regions, and added into SAT for bioaugmentation. The feasibility of bioaugmented SAT and associated PNP removal process were investigated by laboratory sand columns, along with effects of the SAT operative parameters (namely PNP loading concentration, flow rate and soil saturation level of SAT). Within the range of PNP loading stresses tested (1-200 mg L^-1), PNP removal efficiency was optimal at constant flow rate of 219 mL d^-1 in unsaturated operating condition of SAT under 15 °C among all the investigated experimental conditions. Longer hydraulic residence time increased the PNP removal rate, although the accumulated mass removed reduced and the removal efficiencies remained constant in unsaturated operating condition of SAT. It is found from the comparison between the PNP removals via both unsaturated and saturated columns that slight difference only in the removal rate of PNP was observed and the highly efficient bioaugmented SAT can completely degrade PNP of 10 mg L^-1 within 5 wetting/drying cycles under both scenarios.

[Prognostic analysis of stage Ⅰb2 andⅡa2 cervical squamous cancer without high risk factors treated with neo-adjuvant chemotherapy and radical hysterectomy]

Objective: To analyze the prognosis of Ⅰb2 and Ⅱa2 cervical squamous cancer without high risk factors treated with neo-adjuvant chemotherapy (NACT) and radical hysterectomy. Methods: This retrospective study included patients with International Federation of Gynecology and Obstetrics (FIGO) stage Ⅰ b2 and Ⅱ a2 cervical squamous cancer without high risk factors who underwent platinum-based NACT followed by radical surgery from January 2008 to January 2015. The responses of NACT were observed and compared in their effect on postoperative pathologic risk factors. Kaplan-Meier method and Cox regression analysis were performed to analyze survival status. Results: This study was recruited 282 patients with the average age of (44.4±6.7) years old. After NACT, 42 patients achieved complete response [CR, 14.9% (42/282) ], while 138 patients achieved partial response [PR, 48.9% (138/282) ] and 102 stable disease [SD, 36.2% (102/282) ]. The rate of pathologic diameter ≥4 cm, deep stromal invasion (DSI) positive and lymph-vascular space invasion (LVSI) positive rate decreased significantly in CR and PR group compared with SD group (P<0.05) . The number of postoperative risk factors in CR, PR and SD groups varied significantly (χ(2)=64.869, P=0.000) . Besides, the rate of multiple intermediate risk factors was respectively 0 vs 13.8% vs 45.1% (χ(2)=7.107, P=0.008) . The disease relapsed in 23 patients, and 12 died. On the whole series, 5-year overall survival rate was 91.7%, and 5-year recurrence-free survival rate was 88.9%. The rate of recurrence (P=0.002) and mortality (P=0.036) were higher in LVSI positive patients compared with LVSI negative. And the rate of recurrence was higher in patients with multiple intermediate risk factors, compared with no or one intermediate risk factors (P=0.002) . Univariate analysis revealed that LVSI positive and multiple intermediate risk factors were the factors predicted recurrence and mortality (P<0.05) , and no significance in age, stage, tumor grade, tumor diameter before or after NACT, response to NACT, or DSI positive factors (all P>0.05) . The multivariate analysis showed that, the factor of primary tumor diameter ≥6 cm (P=0.022) and multiple intermediate risk factors (P=0.001) were independent prognostic variables for recurrent-free survival. Besides, multiple intermediate risk factors was independent prognostic variable for overall survival (P=0.034) . After surgery, 107 patients did not receive adjuvant therapy, while 175 patients received adjuvant therapy with 26 radiotherapy, 46 chemotherapy and 103 concurrent radiochemotherapy. On survival analysis of postoperative adjuvant treatment, 5-year recurrence-free survival rate of radiotherapy group was significantly lower in patients with the factor of SD response to NACT (P=0.011) and multiple intermediate risk factors (P=0.008) , while overall no significance in overall survival rate (P>0.05) . Conclusions: NACT may be play beneficial role in relieving the status of intermediate risk factors for stage Ⅰ b2 and Ⅱ a2 cervical squamous cancer without high risk factors. The status of multiple intermediate risk factors is independent prognostic factors for recurrence and mortality. For patients with multiple intermediate risk factors, postoperative adjuvant chemotherapy or concurrent radiochemotherapy might be the better choice to prevent relapse.

[Application of liver three-dimensional visualization technologies in the treatment planning of hepatic malignant tumor]

Objective: To discuss the application of three dimentional(3D)visualization technologies in treatment plan of hepatic malignant tumor. Methods: The clinical data of 300 patients with liver malignant tumor who received treatment from January 2016 to January 2017 in the Third Department of Hepatic Surgery of Eastern Hepatobiliary Surgery Hospital was retrospectively analyzed in this study, including 221 male and 79 female patients aged from 7 to 76 years with median age of 54 years. The median height was 168 cm (115-183 cm), the median weight was 65 kg (20-105 kg) and the median tumor volume was 142 ml (23-2 493 ml). Three-dimensional visualization technology was used in all patients to reconstruct liver three-dimensional graphics. Also, two and three-dimensional methods were taken respectively to evaluate patients and develop treatment strategy. The change of treatment strategy caused by 3D evaluation, actual surgical plan, operation time, time of hepatic vascular occlusion, intraoperative blood loss, volumes of blood transfusion and postoperative complications was observed. Results: After three-dimensional visualization technology was applied, 75(25%) of 300 patients' treatment strategies had been changed. The range of hepatectomy was extended in 25 patients. And 7 of them were due to hepatic venous variation, which resulted in increasing drainage area. In other 4 patients, liver resections were extended due to lack of perfusion of the liver parenchyma after the removal of portal vein. And hepatectomy was expanded in 14 patients in order to increase the surgical margin. The range of hepatectomy was reduced in 8 patients, 4 of which were due to hepatic venous variation, such as hepatic vein of segment 4 or lower right posterior hepatic vein. The remaining 4 cases were because of insufficient residual liver volume.The surgical resection was performed in 278 cases, 257 of which received operation directly. Left hepatectomy was performed in 24 patients and right hepatectomy was performed in 33 patients. Left trisectionectomy was carried out in 12 patients and right trisectionectomy was carried out in 11 patients. Caudate lobectomy was applied in 10 patients. There were 18 cases of left lateral sectionectomy, 7 cases of right anterior sectionectomy, 25 cases of right posterior sectionectomy and 18 cases of mesohepatectomy. Single or multi segment resection was performed in 99 patients. The treatment strategy of thirty-six patients was converted to staged hepatectomy (ALPPS 11 cases and portal vein embolization 25 cases). The median operation time was 130 minutes (90-360 minutes) and the median inflow blood occlusion time was 20 minutes (0-75 minutes). Median blood loss volume was 200 ml (20-1 600 ml). Thirty-seven of 278 patients received transfusions, and the average red blood transfusion volume was (4.4±1.7)units (0-8 units). Median hepatic resection volume was 530 ml(30-2 600 ml). There were 117 cases of pleural effusion after operation, including 3 patients needing invasive therapy. Ascites occurred in 23 patients, 6 of whom needed invasive therapy. Biliary leakage was observed in 30 patients. Eight patients occurred hepatic cutting surface hemorrhage, 6 of whom received blood transfusion, and 4 of whom underwent laparotomy to stop bleeding. Three patients had pulmonary infection after surgery and 3 patients appeared biliary obstruction. Deep vein thrombosis took place in 2 patients and portal vein thrombosis was observed in 4 patients. No postoperative liver failure and death ever happened in our study group. Conclusion: Three-dimensional visualization technique can optimize the treatment strategy of patients with liver malignant tumor, improve surgical safety.

Solvent-free nanofluid with three structure models based on the composition of a MWCNT/SiO2 core and its adsorption capacity of CO2

A series of core/shell nanoparticle organic/inorganic hybrid materials (NOHMs) with different weight ratios of two components, consisting of multi-walled carbon nanotubes (MWCNTs) and silicon dioxide (SiO₂) as the core were synthesized. The NOHMs display a liquid-like state in the absence of solvent at room temperature. Five NOHMs were categorized into three kinds of structure states based on different weight ratio of two components in the core, named the power strip model, the critical model and the collapse model. The capture capacities of these NOHMs for CO₂ were investigated at 298 K and CO₂ pressures ranging from 0 to 5 MPa. Compared with NOHMs having a neat MWCNT core, it was revealed that NOHMs with the power strip model show better adsorption capacity toward CO₂ due to its lower viscosity and more reactive groups that can react with CO₂. In addition, the capture capacities of NOHMs with the critical model were relatively worse than the neat MWCNT-based NOHM. The result is attributed to the aggregation of SiO₂ in these samples, which may cause the consumption and hindrance of reactive groups. However, the capture capacity of NOHMs with the collapse model was the worst of all the NOHMs, owing to its lowest content of reactive groups and hollow structure in MWCNTs. In addition, they presented non-interference of MWCNTs and SiO₂ without aggregation state.

ATXN2-AS, a gene antisense to ATXN2, is associated with spinocerebellar ataxia type 2 and amyotrophic lateral sclerosis

OBJECTIVE

Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative disease caused by a CAG repeat expansion in the gene ataxin-2 (ATXN2). ATXN2 intermediate-length CAG expansions were identified as a risk factor for amyotrophic lateral sclerosis (ALS). The ATXN2 CAG repeat is translated into polyglutamine, and SCA2 pathogenesis has been thought to derive from ATXN2 protein containing an expanded polyglutamine tract. However, recent evidence of bidirectional transcription at multiple CAG/CTG disease loci has led us to test whether additional mechanisms of pathogenesis may contribute to SCA2.

METHODS

In this work, using human postmortem tissue, various cell models, and animal models, we provide the first evidence that an antisense transcript at the SCA2 locus contributes to SCA2 pathogenesis.

RESULTS

We demonstrate the expression of a transcript, containing the repeat as a CUG tract, derived from a gene (ATXN2-AS) directly antisense to ATXN2. ATXN2-AS transcripts with normal and expanded CUG repeats are expressed in human postmortem SCA2 brains, human SCA2 fibroblasts, induced SCA2 pluripotent stem cells, SCA2 neural stem cells, and lymphoblastoid lines containing an expanded ATXN2 allele associated with ALS. ATXN2-AS transcripts with a CUG repeat expansion are toxic in an SCA2 cell model and form RNA foci in SCA2 cerebellar Purkinje cells. Finally, we detected missplicing of amyloid beta precursor protein and N-methyl-D-aspartate receptor 1 in SCA2 brains, consistent with findings in other diseases characterized by RNA-mediated pathogenesis.

INTERPRETATION

These results suggest that ATXN2-AS has a role in SCA2 and possibly ALS pathogenesis, and may therefore provide a novel therapeutic target for these diseases. Ann Neurol 2016;80:600-615.

[The experience of abundant amount of pectoralis major myocutaneous flap tissue in restoring parenchyma defect of head and neck]

Objective:Explore the skills to flap the defects of the head and neck with myocutaneous of pectoralis major which has rich amount of organization to minimize complications.Method:Various of neck defects will be repaired when the myocutaneous flap of pectoralis major from obese male or/and female has been prepared with improved methods. First of all, the muscle must be fixed. Then we have to suture the skin and the defect of skin or mucous membrane;the potential closed cavities around the myocutaneous flap must be drainaged with the negative pressure after repaired. Clinical data of 23 (24 sides) patients undergoing the repair in our hospital between January 2008 and December 2014 were collected and reviewed retrospectively.Result:One of 23 cases was injured the thoracoacromial artery in the preparation process of myocutaneous flap by the operator, then we operated on the other side. All of the pectoralis major myocutaneous flaps has been survived except 1 case which was necrosis in distal partial of pectoralis major muscle flap, but healed after changing dressing.Three cases with pharyngeal leakage because of the infection were also healed after changing dressing; skin and skin flap partial dehiscence happend in 1 cases, but also healed after dressing; 1 cases with subcutaneous hemorrhage was healed after cleaning up hematocele.Conclusion:The pectoralis major myocutaneous flap is still a good material for the repair of head and neck defects as long as the management skill in perioperative has been mastered properly, even though the one with rich amount of organization is bloated and the preparation and repair is difficult.

Assessing a peptidylic inhibitor-based therapeutic approach that simultaneously suppresses polyglutamine RNA- and protein-mediated toxicities in patient cells and Drosophila

Polyglutamine (polyQ) diseases represent a group of progressive neurodegenerative disorders that are caused by abnormal expansion of CAG triplet nucleotides in disease genes. Recent evidence indicates that not only mutant polyQ proteins, but also their corresponding mutant RNAs, contribute to the pathogenesis of polyQ diseases. Here, we describe the identification of a 13-amino-acid peptide, P3, which binds directly and preferentially to long-CAG RNA within the pathogenic range. When administered to cell and Drosophila disease models, as well as to patient-derived fibroblasts, P3 inhibited expanded-CAG-RNA-induced nucleolar stress and suppressed neurotoxicity. We further examined the combined therapeutic effect of P3 and polyQ-binding peptide 1 (QBP1), a well-characterized polyQ protein toxicity inhibitor, on neurodegeneration. When P3 and QBP1 were co-administered to disease models, both RNA and protein toxicities were effectively mitigated, resulting in a notable improvement of neurotoxicity suppression compared with the P3 and QBP1 single-treatment controls. Our findings indicate that targeting toxic RNAs and/or simultaneous targeting of toxic RNAs and their corresponding proteins could open up a new therapeutic strategy for treating polyQ degeneration.

Nuclear retention of full-length HTT RNA is mediated by splicing factors MBNL1 and U2AF65

Huntington's disease (HD) is caused by a CAG repeat expansion in the huntingtin (HTT) gene. Recent evidence suggests that HD is a consequence of multimodal, non-mutually exclusive mechanisms of pathogenesis that involve both HTT protein- and HTT RNA-triggered mechanisms. Here we provide further evidence for the role of expanded HTT (expHTT) RNA in HD by demonstrating that a fragment of expHTT is cytotoxic in the absence of any translation and that the extent of cytotoxicity is similar to the cytotoxicity of an expHTT protein fragment encoded by a transcript of similar length and with a similar repeat size. In addition, full-length (FL) expHTT is retained in the nucleus. Overexpression of the splicing factor muscleblind-like 1 (MBNL1) increases nuclear retention of expHTT and decreases the expression of expHTT protein in the cytosol. The splicing and nuclear export factor U2AF65 has the opposite effect, decreasing expHTT nuclear retention and increasing expression of expHTT protein. This suggests that MBNL1 and U2AF65 play a role in nuclear export of expHTT RNA.

Induction of long-term oscillations in the γ frequency band by nAChR activation in rat hippocampal CA3 area

The hippocampal neuronal network oscillation at γ frequency band (γ oscillation) is generated by the precise interaction between interneurons and principle cells. γ oscillation is associated with attention, learning and memory and is impaired in the diseased conditions such as Alzheimer's disease (AD) and schizophrenia. Nicotinic acetylcholine receptor (nAChR) plays an important role in the regulation of hippocampal neurotransmission and network activity. It is not known whether nicotine modulates plasticity of network activity at γ oscillations in the hippocampus. In this study we investigated the effects of nicotine on the long-term changes of KA-induced γ oscillations. We found that hippocampal γ oscillations can be enhanced by a low concentration of nicotine (1μM), such an enhancement lasts for hours after washing out of nicotine, suggesting a form of synaptic plasticity, named as long-term oscillation at γ frequency band (LTOγ). Nicotine-induced LTOγ was mimicked by the selective α4β2 but not by α7 nAChR agonist and was involved in N-methyl-d-aspartate (NMDA) receptor activation as well as depended on excitatory and inhibitory neurotransmission. Our results indicate that nAChR activation induced plasticity in γ oscillation, which may be beneficial for the improvement of cognitive deficiency in AD and schizophrenia.

Phosphorodiamidate morpholino oligomers suppress mutant huntingtin expression and attenuate neurotoxicity

Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Disease pathogenesis derives, at least in part, from the long polyglutamine tract encoded by mutant HTT. Therefore, considerable effort has been dedicated to the development of therapeutic strategies that significantly reduce the expression of the mutant HTT protein. Antisense oligonucleotides (ASOs) targeted to the CAG repeat region of HTT transcripts have been of particular interest due to their potential capacity to discriminate between normal and mutant HTT transcripts. Here, we focus on phosphorodiamidate morpholino oligomers (PMOs), ASOs that are especially stable, highly soluble and non-toxic. We designed three PMOs to selectively target expanded CAG repeat tracts (CTG22, CTG25 and CTG28), and two PMOs to selectively target sequences flanking the HTT CAG repeat (HTTex1a and HTTex1b). In HD patient-derived fibroblasts with expanded alleles containing 44, 77 or 109 CAG repeats, HTTex1a and HTTex1b were effective in suppressing the expression of mutant and non-mutant transcripts. CTGn PMOs also suppressed HTT expression, with the extent of suppression and the specificity for mutant transcripts dependent on the length of the targeted CAG repeat and on the CTG repeat length and concentration of the PMO. PMO CTG25 reduced HTT-induced cytotoxicity in vitro and suppressed mutant HTT expression in vivo in the N171-82Q transgenic mouse model. Finally, CTG28 reduced mutant HTT expression and improved the phenotype of Hdh(Q7/Q150) knock-in HD mice. These data demonstrate the potential of PMOs as an approach to suppressing the expression of mutant HTT.

First Report of Fusarium equiseti Causing a Sheath Rot of Corn in China

Corn is the most important cereal crop in China. Over 34.94 million ha of corn is cultivated in the country annually. However, fungal diseases are a major limiting factor in corn production. In August 2008, 50 ha in several corn fields in Liaoning, Jilin, and Heilongjiang provinces were observed to be severely affected by a disease causing a yield loss of 30%. Results from field surveys suggested an epidemic during late corn growth stages that affected corn sheaths, causing irregularly circular spots with grayish brown to dark brown lesions. Lesions ranged from 2.5 to 3 × 3 to 5 cm. To isolate the causal agent, tissue was removed from the border of lesions and surface sterilized in 75% ethanol for 30 sec and 0.1% HgCl₂ for 1 min. The sample was then triple rinsed in sterile distilled water. The isolate was purified and subcultured on potato dextrose agar (PDA) at 25 ± 2°C. The initial color of the mycelium was white, turning brown after being cultured for 7 days. A pale brown to dark brown pigment developed in the agar beneath the colony. Chlamydospores, solitary but also in short chains, measuring 7.2 to 15.3 μm, were produced on carnation leaf agar (CLA) after 10 days and became verrucose 20 days later. Macroconidia were produced on CLA in orange sporodochia from monophialides on branched conidiophores, usually 5- to 7-septate, and apical cells were tapered and elongate. Basal cells were prominent, foot-shaped, and elongated in appearance. Microconidia were not observed (1). These morphological characteristics matched the description of Fusarium equiseti reported by Leslie and Summerell (1). A pathogenicity test was conducted with an isolate from each of the 36 corn plants by spraying 2 ml of spore suspension (10⁶ conidia/ml) on 45-day-old corn sheaths (cv. Huang Zao). For the control treatment, 36 corn plants were sprayed with an equal volume of sterilized water. Inoculated plants were placed in a greenhouse at 32 to 34°C and 95% relative humidity. Typical irregularly circular lesions were observed 7 days after inoculation, except in the control samples. Each treatment was replicated three times. The suspected pathogen was consistently re-isolated from diseased tissue according to Koch's postulates, and was found to be morphologically similar to F. equiseti. Preliminary morphological identification of the fungus was confirmed by a PCR assay using genomic DNA extracted from the mycelia of a 7-day-old culture on PDA at 25 ± 2°C. A 750-bp amplified region of the transcription elongation factor (TEF) of rDNA was generated using TEF1 (5'-ATGGGTAAGGAGGACAAGAC-3') and TEF2 (5'-GGAAGTACCAGTGATCATGTT-3') primers. The TEF region (GenBank Accession No. KF754798) was sequenced by Sangon Biotech Co., Ltd. (Shanghai, China) and displayed 99% nucleotide similarity with the rDNA-TEF of F. equiseti (JN127347.1) separately after a BLASTn search in GenBank. Based on the symptoms, fungal morphology, TEF sequence, and pathogenicity testing, this fungus was identified as F. equiseti. To our knowledge, this is the first report of F. equiseti on corn sheaths in China. This report will establish a foundation for further study of F. equiseti to address the disease effectively and to determine the severity of damage caused by F. equiseti. Reference: (1) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell, Ames, IA, 2006.

First Report of Bipolaris papendorfii Causing Corn Leaf Spot in China

Corn is the most important cereal crop in China, with over 34.94 million ha being cultivated in the country annually. However, fungal diseases are a major limiting factor in corn production. In August 2012, 20 ha of corn fields in Anhui Province were found to be heavily infected by fungi. The margin of the lesion was achlorotic, and the middle was yellowish white or off-white, which was similar to the corn Curvalaria leaf spot. The oval lesions were approximately 5 to 7 mm. Lesion tissue was removed from the border between symptomatic and healthy tissue. The surface was sterilized in 75% ethanol for 30 s and 0.1% HgCl₂ for 1 min, after which the sample was washed three times in sterile distilled water. The isolate was purified and subcultured on potato dextrose agar (PDA) at 25 ± 2°C. The initial color of the colony was light brown, turning dark brown after being cultured for 7 days. The conidia were boat-shaped or inverted pear-shaped and were clearly bent to one side. The cells of both ends were slightly lighter and respectively ranged from 34.5 to 44.0 μm and 12.0 to 21.0 μm away from the base, with the second cell as the widest. The majority conidia had three or four false septates; isolates produced light brown to medium brown conidiophore, scattered or clustered, often branching, and exhibited bending. These morphological characteristics matched with the description of Bipolaris papendorfii reported by Zhang (3). A pathogenicity test was conducted with the two isolates on each of the 36 corns by spraying 2 ml spore suspension (10⁶ conidia/ml). For the control treatment, 36 corns were inoculated with an equal volume of sterilized water. Inoculated plants were placed in a greenhouse from 29 to 33°C and 95% relative humidity. The typical 5 to 7 mm oval lesions were observed 7 days after inoculation, except on the control samples. Three replications of 36 corns were used for each treatment. The isolate was consistently 100% reisolated from the diseased tissue according to Koch's postulate. The isolate was found to be morphologically similar to B. papendorfii. Preliminary morphological identification of the fungus was confirmed by PCR assay using genomic DNA extracted from the mycelium of a 7-day-old culture on PDA at 25 ± 2°C. A 550-bp amplified region of the internal transcribed spacer (ITS) of rDNA was generated using ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') universal primers (1). The ITS region (GenBank Accession No. KC592365) was then sequenced by Sangon Biotech (Shanghai, China), and displayed 99% nucleotide similarity with the rDNA-ITS of B. papendorfii (JQ753972.1) separately after BLASTn research in GenBank. Based on the symptoms, fungal morphology, ITS sequence, and pathogenicity testing, this fungus was identified as B. papendorfii. The pathogen could reportedly infect tobacco and cotton (2). To our knowledge, this is the first study to report that B. papendorfii can infect corn in China. This report will establish a foundation for the further study of B. papendorfii to address the disease effectively. Further studies will be conducted to determine the incidence of the disease and the severity of damage caused by B. papendorfii as well as determine a possible mode for controlling the spread of the disease. References: (1) Y. J. Cao et al. Chin. J. Trop. Crops 31:1098, 2010. (2) H. Deng et al. Mycosystema 21:327, 2002. (3) T. Y. Zhang. Chin. Fungi Chi. 30:21, 2010.

Reciprocal regulation of axonal Filopodia and outgrowth during neuromuscular junction development

Background

The assembly of the vertebrate neuromuscular junction (NMJ) is initiated when nerve and muscle first contact each other by filopodial processes which are thought to enable close interactions between the synaptic partners and facilitate synaptogenesis. We recently reported that embryonic Xenopus spinal neurons preferentially extended filopodia towards cocultured muscle cells and that basic fibroblast growth factor (bFGF) produced by muscle activated neuronal FGF receptor 1 (FGFR1) to induce filopodia and favor synaptogenesis. Intriguingly, in an earlier study we found that neurotrophins (NTs), a different set of target-derived factors that act through Trk receptor tyrosine kinases, promoted neuronal growth but hindered presynaptic differentiation and NMJ formation. Thus, here we investigated how bFGF- and NT-signals in neurons jointly elicit presynaptic changes during the earliest stages of NMJ development.

Methodology/Principal Findings

Whereas forced expression of wild-type TrkB in neurons reduced filopodial extension and triggered axonal outgrowth, expression of a mutant TrkB lacking the intracellular kinase domain enhanced filopodial growth and slowed axonal advance. Neurons overexpressing wild-type FGFR1 also displayed more filopodia than control neurons, in accord with our previous findings, and, notably, this elevation in filopodial density was suppressed when neurons were chronically treated from the beginning of the culture period with BDNF, the NT that specifically activates TrkB. Conversely, inhibition by BDNF of NMJ formation in nerve-muscle cocultures was partly reversed by the overexpression of bFGF in muscle.

Conclusions

Our results suggest that the balance between neuronal FGFR1- and TrkB-dependent filopodial assembly and axonal outgrowth regulates the establishment of incipient NMJs.

Differential regulation of axonal growth and neuromuscular junction assembly by HGF/c-Met signaling

BACKGROUND

During vertebrate neuromuscular junction (NMJ) development, contact between motor axons and muscle fibers is followed by pre- and post-synaptic specialization. Using Xenopus nerve-muscle cocultures, we recently showed that spinal neurons initially contacted muscle cells by means of filopodial processes, and that muscle-derived basic fibroblast growth factor induced axonal filopodia and slowed axonal advance to promote nerve-muscle interaction and NMJ establishment. In contrast, neurotrophins enhanced axonal growth but suppressed the extension of axonal filopodia and blocked NMJ formation.

RESULTS

Here we report that hepatocyte growth factor (HGF), which also supports motor neuron survival, was expressed by Xenopus muscle cells, and that forced expression of HGF in Xenopus spinal neurons inhibited the extension of axonal filopodia. Overexpression of the HGF-receptor c-Met in neurons also blocked the formation of axonal filopodia and furthermore sped up axonal growth, but a kinase-dead form of c-Met was unable to effect these changes. Importantly, treatment of nerve-muscle cocultures with recombinant HGF or the expression of HGF or active c-Met in neurons, or that of excess HGF in muscle, inhibited nerve-induced AChR clustering in muscle.

CONCLUSIONS

Our results suggest that HGF/c-Met signaling in neurons promotes axonal growth but suppresses filopodial assembly in neurons and hinders NMJ establishment.

Regulation of axonal growth and neuromuscular junction formation by neuronal phosphatase and tensin homologue signaling

Axonal growth and synaptogenesis are sequential events of neuronal development. Phosphatase and tensin homologue (PTEN) is expressed in motor neurons, and its disruption leads to continued axonal extension, even upon muscle contact, leading to synaptogenic suppression. Thus PTEN is involved in target-mediated cessation of axonal growth and subsequent synaptic differentiation.

During the development of the vertebrate neuromuscular junction (NMJ), motor axon tips stop growing after contacting muscle and transform into presynaptic terminals that secrete the neurotransmitter acetylcholine and activate postsynaptic ACh receptors (AChRs) to trigger muscle contraction. The neuron-intrinsic signaling that retards axonal growth to facilitate stable nerve–muscle interaction and synaptogenesis is poorly understood. In this paper, we report a novel function of presynaptic signaling by phosphatase and tensin homologue (PTEN) in mediating a growth-to-synaptogenesis transition in neurons. In Xenopus nerve–muscle cocultures, axonal growth speed was halved after contact with muscle, when compared with before contact, but when cultures were exposed to the PTEN blocker bisperoxo (1,10-phenanthroline) oxovanadate, axons touching muscle grew ∼50% faster than their counterparts in control cultures. Suppression of neuronal PTEN expression using morpholinos or the forced expression of catalytically inactive PTEN in neurons also resulted in faster than normal axonal advance after contact with muscle cells. Significantly, interference with PTEN by each of these methods also led to reduced AChR clustering at innervation sites in muscle, indicating that disruption of neuronal PTEN signaling inhibited NMJ assembly. We thus propose that PTEN-dependent slowing of axonal growth enables the establishment of stable nerve–muscle contacts that develop into NMJs.

The function of p120 catenin in filopodial growth and synaptic vesicle clustering in neurons

The signaling by p120 catenin via its downstream effector RhoA is essential for filopodial growth and synaptic vesicle clustering along spinal axons and contributes to the formation of the neuromuscular junction.

At the developing neuromuscular junction (NMJ), physical contact between motor axons and muscle cells initiates presynaptic and postsynaptic differentiation. Using Xenopus nerve–muscle cocultures, we previously showed that innervating axons induced muscle filopodia (myopodia), which facilitated interactions between the synaptic partners and promoted NMJ formation. The myopodia were generated by nerve-released signals through muscle p120 catenin (p120ctn), a protein of the cadherin complex that modulates the activity of Rho GTPases. Because axons also extend filopodia that mediate early nerve–muscle interactions, here we test p120ctn's function in the assembly of these presynaptic processes. Overexpression of wild-type p120ctn in Xenopus spinal neurons leads to an increase in filopodial growth and synaptic vesicle (SV) clustering along axons, whereas the development of these specializations is inhibited following the expression of a p120ctn mutant lacking sequences important for regulating Rho GTPases. The p120ctn mutant also inhibits the induction of axonal filopodia and SV clusters by basic fibroblast growth factor, a muscle-derived molecule that triggers presynaptic differentiation. Of importance, introduction of the p120ctn mutant into neurons hinders NMJ formation, which is observed as a reduction in the accumulation of acetylcholine receptors at innervation sites in muscle. Our results suggest that p120ctn signaling in motor neurons promotes nerve–muscle interaction and NMJ assembly.

Axonal filopodial asymmetry induced by synaptic target

Early nerve–muscle interaction that leads to neuromuscular junction formation is mediated by axonal filopodia that are oriented preferentially toward the muscle as a result of target-derived basic fibroblast growth factor.

During vertebrate neuromuscular junction (NMJ) assembly, motor axons and their muscle targets exchange short-range signals that regulate the subsequent steps of presynaptic and postsynaptic specialization. We report here that this interaction is in part mediated by axonal filopodia extended preferentially by cultured Xenopus spinal neurons toward their muscle targets. Immunoblotting and labeling experiments showed that basic fibroblast growth factor (bFGF) was expressed by muscle and associated with the cell surface, and treatment of cultured spinal neurons with recombinant bFGF nearly doubled the normal density of filopodia in neurites. This effect of bFGF was abolished by SU5402, a selective inhibitor of FGF-receptor 1 (FGFR1), and forced expression of wild-type or dominant-negative FGFR1 in neurons enhanced or suppressed the assembly of filopodia, respectively. Significantly, in nerve–muscle cocultures, knocking down bFGF in muscle decreased both the asymmetric extension of filopodia by axons toward muscle and the assembly of NMJs. In addition, neurons expressing dominant-negative FGFR1 less effectively triggered the aggregation of muscle acetylcholine receptors at innervation sites than did control neurons. These results suggest that bFGF activation of neuronal FGFR1 generates filopodial processes in neurons that promote nerve–muscle interaction and facilitate NMJ establishment.

Chronic lithium treatment of B lymphoblasts from bipolar disorder patients reduces transient receptor potential channel 3 levels

Chronic lithium treatment of B-lymphoblast cell lines (BLCLs) from bipolar-I disorder (BD-I) patients and healthy subjects ex vivo attenuates agonist- and thapsigargin-stimulated intracellular calcium (Ca(2+)) responses. As these findings suggest that chronic lithium treatment modifies receptor (ROCE) and/or store-operated Ca(2+) entry (SOCE) mechanisms, we determined whether chronic lithium treatment of BLCLs modified the expression of two members of the transient receptor potential channels (TRPC1 & 3), which participate in ROCE/SOCE. Chronic lithium treatment significantly reduced BLCL TRPC3 immunoreactivity (repeated-measures ANOVA, P=0.00005), with interaction effects of diagnosis (P=0.037) and sex (P=0.040). The lithium-induced decrease was greatest in BLCLs from female BD-I patients compared with those from healthy females (-27%) and with vehicle-treated BLCLs from female BD-I patients (-33%). However, lithium treatment did not affect TRPC1 and 3 mRNA levels, and TRPC1 immunoreactivity. Downregulation of TRPC3 may be an important mechanism by which lithium ameliorates pathophysiological Ca(2+) disturbances as observed in BD.

Tetraspan protein CD151: a common target of mood stabilizing drugs?

The latency in onset of antimanic and mood stabilizing effects of lithium suggest that long-term neuronal adaptations mediated by changes in gene expression may be important to the therapeutic action of lithium treatment. Using differential display-polymerase chain reaction, several novel, hitherto unexpected lithium-regulated genes have been isolated, all of which would not have been predicted with the candidate gene approach. During the process of characterizing one of these novel genes, we have identified a cDNA clone, a homolog of human/mouse transmembrane-4-superfamily (also known as tetraspan) protein, CD151, the expression of which was significantly decreased in rat frontal cortex following chronic (five weeks) lithium treatment. The reduction of CD151 mRNA levels was also observed following chronic administration of carbamazepine and valproate. Conversely, the expression of CD151 was not altered by short-term (one week) lithium treatment and by chronic administration of the tricyclic antidepressant, imipramine, or the typical antipsychotic, haloperidol, further demonstrating time dependence and pharmacological specificity of this effect. Our studies, thus, indicate that CD151 may represent a therapeutically relevant target common to lithium and the anticonvulsant mood stabilizing drugs, carbamazepine and valproate.

Altered IMPA2 gene expression and calcium homeostasis in bipolar disorder

Reduced inositol monophosphatase (IMPase) activity and elevated basal intracellular calcium levels ([Ca(2+)](B)) have been reported in B lymphoblast cell lines (BLCLs) from bipolar I affective disorder (BD-I) patients, which may reflect cellular endophenotypes of this disorder. As the PI cycle couples to intracellular Ca(2+) mobilization, these two putative endophenotypes may be related. Using an RT-PCR assay, mRNA levels were estimated for IMPA1 and 2 genes encoding human IMPase 1 and 2, respectively, in BLCLs phenotyped on [Ca(2+)](B), from patients with a DSM-IV diagnosis of BD-I (n = 12 per phenotype) and from age- and sex-matched healthy subjects (n = 12). IMPA2 mRNA levels were significantly lower in BLCLs from male BD-I patients with high [Ca(2+)](B) (n = 6) compared with healthy male subjects (n = 5) (-52%, P = 0.013), male BD-I patients with normal BLCL [Ca(2+)](B) (n = 8) (-42%, P = 0.003) and female BD-I patients with high [Ca(2+)](B) (n = 6) (-59%, P = 0.0004). A significant negative correlation was observed between IMPA2 mRNA levels and [Ca(2+)](B) in BLCLs from male (P = 0.046), but not female BD-I patients. Sex-dependent differences were also evident in postmortem temporal cortex IMPA2 mRNA levels which, in contrast to BLCLs, were significantly higher in male BD-I subjects compared with male controls (P = 0.025, n = 4/group). Collectively, these observations suggest a potential sex-dependent link between abnormalities in IMPA2 expression and calcium homeostasis in the pathophysiology of BD.

Altered TRPC7 gene expression in bipolar-I disorder

BACKGROUND

As altered storage-operated calcium (Ca(2+)) entry (SOCE) may affect Ca(2+) homeostasis in bipolar disorder (BD), we determined whether changes occur in the expression of TRPC7 and SERCA2s, proteins implicated or known to be involved in SOCE, in B lymphoblast cell lines (BLCLs) from BD-I patients and comparison subjects.

METHODS

mRNA levels were determined in BLCL lysates from BD-I, BD-II, and major depressive disorder patients, and healthy subjects by comparative reverse transcriptase-polymerase chain reaction, and BLCL basal intracellular Ca(2+) concentration ([Ca(2+)]B) was determined by ratiometric spectrophotometry using Fura-2, in aliquots of the same cell lines, at 13-16 passages in culture.

RESULTS

TRPC7 mRNA levels were significantly lower in BLCLs from BD-I patients with high BLCL [Ca(2+)]B compared with those showing normal [Ca(2+)]B (-33%, p =.017) and with BD-II patients (-48%, p =.003), major depressive disorder patients (-47%, p =.049) and healthy subjects (-33%, p =.038). [Ca(2+)]B also correlated inversely with TRPC7 mRNA levels in BLCLs from the BD-I group as a whole (r = -.35, p =.027).

CONCLUSIONS

Reduced TRPC7 gene expression may be a trait associated with pathophysiological disturbances of Ca(2+) homeostasis in a subgroup of BD-I patients.

Rejuvenation of degenerative thymus by oral melatonin administration and the antagonistic action of melatonin against hydroxyl radical-induced apoptosis of cultured thymocytes in mice

The effect of melatonin on age-related thymic involution and apoptosis induced by hydroxyl radicals (*OH) in mouse thymocyte cultures was investigated. Exogenous melatonin was administered in the drinking water (15 microg/mL) of 7-month-old male Balb/c mice for 40 consecutive days. Our results show that melatonin distinctly reversed the age-related thymic involution as revealed by the notable increase of cellular density, particularly the number of thymocytes, percentage of thymocytes at G2+S phases and the younger morphological appearance as a whole when compared with control animals. More strikingly, the recovery of these morphometric parameters were maintained for 30 days after the termination of melatonin administration suggesting that the re-established homeostasis by melatonin may last for a longer time. At the same time, when primary culture of thymocytes was preincubated with 200 microM melatonin before their exposure to hydroxyl radicals (*OH) generated by Fe(2+)-mediated Fenton reaction, apoptotic cell death induced by *OH was almost completely prevented as determined by both flow cytometric analysis and the TUNEL assay. DNA laddering assay also documented the inhibition of thymocyte apoptosis by melatonin. Furthermore, we found that the *OH-induced increment of caspase-3 activity in thymocytes was completely abolished by melatonin preincubation. Taken together, our study indicates that in addition to other mechanisms, melatonin may also directly act as an antioxidant via attenuating apoptotic thymocyte death caused by free radicals and stimulates thymocyte proliferation in thymus and thus to rejuvenate the degenerative organ.

Simian virus 40 Vp1 DNA-binding domain is functionally separable from the overlapping nuclear localization signal and is required for effective virion formation and full viability

A DNA-binding domain (DBD) was identified on simian virus 40 (SV40) major capsid protein Vp1, and the domain's function in the SV40 life cycle was examined. The DBD was mapped by assaying various recombinant Vp1 proteins for DNA binding in vitro. The carboxy-terminal 58-residue truncated Vp1DeltaC58 pentamer bound DNA with a K(d) of 1.8 x 10(-9) M in terms of the protein pentamer, while full-length Vp1 and carboxy-terminal-17-truncated Vp1DeltaC17 had comparable apparent K(d)s of 5.3 x 10(-9) to 7.3 x 10(-9) M in terms of the protein monomers. Previously identified on Vp1 was a nuclear localization signal (NLS) consisting of two N-terminal basic clusters, NLS1 (4-KRK-6) and NLS2 (15-KKPK-18). Vp1DeltaC58 pentamers harboring multiple-point mutations in NLS1 (NLSm1), NLS2 (NLSm2), or both basic clusters (NLSm1. 2) had progressively decreased DNA-binding activity, down to 0.7% of the Vp1DeltaC58 level for NLSm1. 2 Vp1. These data, along with those of N-terminally truncated proteins, placed the DBD in overlap with the bipartite NLS. The role of the Vp1 DBD during infection was investigated by taking advantage of NLS phenotypic complementation (N. Ishii, A. Nakanishi, M. Yamada, M. H. Macalalad, and H. Kasamatsu, J. Virol. 68:8209-8216, 1994), in which an NLS-defective Vp1 could localize to the nucleus in the presence of wild-type minor capsid proteins Vp2 and Vp3. This approach made it possible to dissect the role of the bifunctional Vp1 NLS-DBD in virion assembly in the nucleus. Mutants of the viable nonoverlapping SV40 (NO-SV40) DNA NLSm1, NLSm2, and NLSm1. 2 replicated normally following transfection into host cells and produced capsid proteins at normal levels. All mutant Vp1s were able to interact with Vp3 in vitro. The mutants NLSm1 and NLSm1. 2 were nonviable, and the mutant Vp1s unexpectedly failed to localize to the nucleus though Vp2 and Vp3 did, suggesting that the mutated NLS1 acted as a dominant signal for the cytoplasmic localization of Vp1. Mutant NLSm2, for which the mutant Vp1's nuclear localization defect was complemented by Vp2 and Vp3, displayed a 5,000-fold reduced viability. Analysis of NLSm2 DNA-transfected cell lysate revealed a 10-fold reduction in the level of DNase I-protected viral DNA, and yet virion-like particles were found among the DNase I-resistant material. Collective results support a role for Vp1 NLS2-DBD2 in the assembly of virion particles. The results also suggest that this determinant can function in the infection of new cells.

Molecular cloning of a novel isoform of diphosphoinositol polyphosphate phosphohydrolase: a potential target of lithium therapy

The mechanisms underlying the therapeutic effects of lithium are largely unknown but may involve progressive adaptive alterations at the level of gene expression. Using differential display PCR, we identify a novel cDNA fragment, the expression of which was increased in the rat frontal cortex after 5 weeks of lithium administration. A full-length cDNA (2954-nt) was cloned by arrayed cDNA library screening, and sequencing of the clone revealed an open reading frame of 537-bp encoding a 179-residue protein. Amino acid sequence comparisons revealed that our clone is a member of the Nudix hydrolase family, with the highest percentage of homology (95%) being with a subtype of human diphosphoinositol polyphosphate phosphohydrolase, hDIPP2. Northern blot analysis revealed that chronic lithium treatment significantly increased rDIPP2 mRNA levels in frontal cortex, but not in hippocampus, midbrain, and cerebellum. The effect of lithium on rDIPP2 mRNA expression was not shared by two other anticonvulsant mood stabilizers, carbamazepine and valproate. Time-course studies showed that 1-week of lithium had no effect on rDIPP2 mRNA abundance in the frontal cortex. Our results suggest that DIPP2 may represent a biologically relevant target of lithium therapy, further supporting the notion that abnormalities in inositol phosphate metabolism may be significant in the pathophysiology and pharmacotherapy of bipolar disorder.

Role of simian virus 40 Vp1 cysteines in virion infectivity

We have developed a new nonoverlapping infectious viral genome (NO-SV40) in order to facilitate structure-based analysis of the simian virus 40 (SV40) life cycle. We first tested the role of cysteine residues in the formation of infectious virions by individually mutating the seven cysteines in the major capsid protein, Vp1. All seven cysteine mutants-C9A, C49A, C87A, C104A, C207S, C254A, and C267L-retained viability. In the crystal structure of SV40, disulfide bridges are formed between certain Cys104 residues on neighboring pentamers. However, our results show that none of these disulfide bonds are required for virion infectivity in culture. We also introduced five different mutations into Cys254, the most strictly conserved cysteine across the polyomavirus family. We found that C254L, C254S, C254G, C254Q, and C254R mutants all showed greatly reduced (around 100,000-fold) plaque-forming ability. These mutants had no apparent defect in viral DNA replication. Mutant Vp1's, as well as wild-type Vp2/3, were mostly localized in the nucleus. Further analysis of the C254L mutant revealed that the mutant Vp1 was able to form pentamers in vitro. DNase I-resistant virion-like particles were present in NO-SV40-C254L-transfected cell lysate, but at about 1/18 the amount in wild-type-transfected lysate. An examination of the three-dimensional structure reveals that Cys254 is buried near the surface of Vp1, so that it cannot form disulfide bonds, and is not involved in intrapentamer interactions, consistent with the normal pentamer formation by the C254L mutant. It is, however, located at a critical junction between three pentamers, on a conserved loop (G2H) that packs against the dual interpentamer Ca(2+)-binding sites and the invading C-terminal helix of an adjacent pentamer. The substitution by the larger side chains is predicted to cause a localized shift in the G2H loop, which may disrupt Ca(2+) ion coordination and the packing of the invading helix, consistent with the defect in virion assembly. Our experimental system thus allows dissection of structure-function relationships during the distinct steps of the SV40 life cycle.

Associated disturbances in calcium homeostasis and G protein-mediated cAMP signaling in bipolar I disorder

BACKGROUND

Evidence of extensive cross-talk between calcium (Ca(2+))- and cAMP-mediated signaling systems suggests that previously reported abnormalities in Ca(2+) homeostasis in bipolar I (BP-I) patients may be linked to disturbances in the function of G proteins that mediate cAMP signaling.

METHODS

To test this hypothesis, the beta-adrenergic agonist, isoproterenol, and the G protein activator, sodium fluoride (NaF), were used to stimulate cAMP production in B lymphoblasts from healthy and BP-I subjects phenotyped on basal intracellular calcium concentration ([Ca(2+)](B)). cAMP was measured by radioimmunoassay and [Ca(2+)](B) by ratiometric fluorometry with fura-2.

RESULTS

Isoproterenol- (10 microM) stimulated cAMP formation was lower in intact B lymphoblasts from BP-I patients with high [Ca(2+)](B) (>/= 2 SD above the mean concentration of healthy subjects) compared with patients having normal B lymphoblast [Ca(2+)](B) and with healthy subjects. Although basal and NaF-stimulated cAMP production was greater in B lymphoblast membranes from male BP-I patients with high versus normal [Ca(2+)](B), there were no differences in the percent stimulation. This suggests the differences in NaF response resulted from higher basal adenylyl cyclase activity.

CONCLUSIONS

These findings suggest that trait-dependent disturbances in processes regulating beta-adrenergic receptor sensitivity and G protein-mediated cAMP signaling occur in conjunction with altered Ca(2+) homeostasis in those BP-I patients with high B lymphoblast [Ca(2+)](B).

Lithium regulation of aldolase A expression in the rat frontal cortex: identification by differential display

BACKGROUND

Substantial evidence indicates that lithium may exert its therapeutic effects through progressive adaptive changes at the level of gene expression; however, the study of lithium-regulated genes has been primarily undertaken with the "candidate gene" approach based on a specific testable hypothesis. The aim of our study was to identify lithium-regulated genes that would not be predicted a priori by the candidate gene approach.

METHODS

Differential display polymerase chain reaction was used to isolate and identify messenger RNAs (mRNAs) that are differentially expressed in the frontal cortex of rats given lithium for 5 weeks to achieve plasma lithium concentrations of 0.6 to 0.9 mmol/L.

RESULTS

A putative lithium-regulated complementary DNA fragment (LRG1) was identified. Northern blot analysis revealed that 5 weeks of lithium treatment, but not 1 week, significantly reduced LRG1 mRNA levels. LRG1 mRNA levels were similarly reduced by 5 weeks of carbamazepine, but not valproate administration. Sequence analysis and search of the GenBank database revealed that LRG1 is analogous to the sequence of the gene for rat aldolase A.

CONCLUSIONS

These results demonstrate that chronic administration of lithium, but not short-term administration, down regulates the levels of aldolase A mRNA, suggesting this effect may play a role in mediating the therapeutic action of this agent.

The human nucleus accumbens is highly susceptible to G protein down-regulation by methamphetamine and heroin

Although the nucleus accumbens is assumed to be a critical brain "pleasure center," its function in humans is unknown. As animal data suggest that a unique feature of this small brain area is its high sensitivity to down-regulation of an inhibitory G protein by drugs of abuse, we compared G protein levels in postmortem nucleus accumbens with those in seven other brain regions of chronic users of cocaine, methamphetamine, and heroin, and of matched controls. Biochemical changes were restricted to the nucleus accumbens in which concentrations of G(alpha)1 and/or G(alpha)2 were reduced by 32-49% in the methamphetamine and heroin users. This selective responsiveness to these abused drugs implies a special role for the human nucleus accumbens in mechanisms of drug reinforcement and suggests that some features of the drug-dependent state (e.g., tolerance) might be related to inhibition of G(alpha)1-linked receptor activity.

Reduced adenylyl cyclase immunolabeling and activity in postmortem temporal cortex of depressed suicide victims

BACKGROUND

Previous studies have found altered receptor/G protein-modulated adenylyl cyclase (AC) activity in subjects with mood disorders.

METHODS

To investigate whether these effects are associated with altered levels of specific isoforms of AC, we measured AC isoform I, IV and V/VI immunoreactivities in postmortem temporal cortex from nine depressed suicide victims, nine subjects with bipolar disorder (BD) and 18 age-matched non-psychiatric controls. Basal, GTPgammaS- and forskolin-stimulated AC activities were measured in the temporal cortex from the nine depressed suicide victims and their controls.

RESULTS

Western blotting revealed significant reductions in immunolabeling in AC type IV (-49%; p < 0.05) in depressed suicide subjects compared to age-matched controls, but no differences were found in AC type I or type V/VI. There were no statistically significant differences in AC type I, IV or V/VI immunoreactivities between BD and matched control subjects. Functionally, there was a significant reduction in forskolin-stimulated AC activity in depressed suicide subjects compared to controls, which may be, in part, related to higher basal AC activity in the former group.

LIMITATIONS

Our sample size was small with diverse subject characteristics.

CONCLUSIONS

These preliminary findings suggest altered levels and/or function in AC type IV may contribute to disturbances in the postreceptor cAMP signaling cascade in depression.

Increased cyclic AMP-dependent protein kinase activity in postmortem brain from patients with bipolar affective disorder

Previous observations of reduced [3H]cyclic AMP binding in postmortem brain regions from bipolar affective disorder subjects imply cyclic AMP-dependent protein kinase function may be altered in this illness. To test this hypothesis, basal and stimulated cyclic AMP-dependent protein kinase activity was determined in cytosolic and particulate fractions of postmortem brain from bipolar disorder patients and matched controls. Maximal enzyme activity was significantly higher (104%) in temporal cortex cytosolic fractions from bipolar disorder brain compared with matched controls. In temporal cortex particulate fractions and in the cytosolic and particulate fractions of other brain regions, smaller but statistically nonsignificant increments in maximal enzyme activity were detected. Basal cyclic AMP-dependent protein kinase activity was also significantly higher (40%) in temporal cortex cytosolic fractions of bipolar disorder brain compared with controls. Estimated EC50 values for cyclic AMP activation of this kinase were significantly lower (70 and 58%, respectively) in both cytosolic and particulate fractions of temporal cortex from bipolar disorder subjects compared with controls. These findings suggest that higher cyclic AMP-dependent protein kinase activity in bipolar disorder brain may be associated with a reduction of regulatory subunits of this enzyme, reflecting a possible adaptive response of this transducing enzyme to increased cyclic AMP signaling in this disorder.

Characterization of alpha(s)-immunoreactive ADP-ribosylated proteins in postmortem human brain

ADP-ribosylation of the stimulatory G protein alpha subunit, alpha(s), has been demonstrated in a number of different mammalian tissues. However, little is known about the occurrence and role of this process in modifying alpha(s) levels/function in human brain. In the present study, endogenous and cholera toxin (CTX)-catalyzed [32P]ADP-ribosylated products were characterized in postmortem human temporal cortex by (1) immunoprecipitation with alpha(s) antisera (RM/1), (2) comparisons of immunoblots and autoradiograms of the [32P]ADP-ribosylated products, and (3) limited protease digestion. Of the three major endogenous [32P]ADP-ribosylated products (48, 45, and 39 kDa) in postmortem brain, the 48-kDa and 45-kDa bands were clearly identified as alpha(s-L) (long isoform) and alpha(s-S) (short isoform), respectively. RM/1 immunoprecipitated the 39-kDa [32P]ADP-ribosylated protein, and overlays of immunoblots and autoradiograms showed that this product corresponded to an alpha(s)-like-immunoreactive protein. Furthermore, limited protease digestion of the 39-kDa endogenous [32P]ADP-ribosylated band generated peptide fragments similar to both endogenous and CTX-catalyzed [32P]ADP-ribosylated alpha(s-S). Two major CTX-catalyzed [32P]ADP-ribosylated products were also identified as alpha(s-L) (52 kDa) and alpha(s-S) (45 kDa). These findings clearly demonstrate that alpha(s) is a substrate for endogenous and CTX-catalyzed [32P]ADP-ribosylation in postmortem human brain. Furthermore, a lower molecular weight alpha(s)-like immunoreactive protein is also expressed in human brain and is a substrate for endogenous but not CTX-catalyzed [32P]ADP-ribosylation.

Lithium, but not carbamazepine, potentiates hyperactivity induced by intra-accumbens cholera toxin

Elevated G protein abundance and/or function has been implicated in the pathophysiology and pharmacotherapy of bipolar affective disorder. To test the interactions between chronic lithium and carbamazepine on behavioral changes induced by cholera toxin (CTX), which catalyzes ADP-ribosylation and constitutively activates G alphas/olf, rats were given chronic dietary lithium, carbamazepine (CBZ), or regular food (REG) and injected bilaterally in the nucleus accumbens (nACC) with CTX (400 ng/ml/side) or vehicle. Locomotor activity was tested daily for 2 weeks after the injection. CTX increased locomotor activity, but a significant interaction between drug treatment and CTX reflected a two- to threefold increase of CTX-induced hyperactivity in the lithium-treated group. In contrast, on day 1, the CBZ-CTX group was significantly more active than the the LI-CTX and REG-CTX groups, both of which had suppressed locomotor activity. There was a significant reduction in CTX-catalyzed ADP ribosylation of G alphas (52 kDa and 45 kDa) in the nucleus accumbens in all three CTX-treated groups. The potentiation of the behavioral effect of CTX by lithium supports the hypothesis that lithium interacts with G proteins; however, the mechanism of interaction appears to be more complex than direct attenuation of G alphas function, as previously suggested.

[Screening new photosensitizers from Chinese medicinal herbs and searching for herbal photodynamic killing effects on human stomach cancer cells]

OBJECTIVE

To find new photosensitizers from Chinese medicinal herbs for cancer photodynamic therapy.

METHODS

The extracts of thirteen herbs were examined: (1) Their fluorescence excitation wave lengths and emission wave lengths; (2) Their fluorescence intensity in living cells and (3) Their distribution and localization in the living cells and the fixed cells both stained in each extract, and responses of cell fluorescence intensity to pH value change. Furthermore, the herb's anticancer photosensitive efficiencies were studied by using BCG-823 human stomach cancer cells.

RESULTS

Cortex phellodendri and Rhizoma Coptidis, were found with optimal fluorescence properties as photosensitizers in this test. The latter could remarkably reduce the cell metabolic viability, proliferative ability and increased the cell mortality when the cells exposed to both drugs and luminance but not only to drug.

CONCLUSIONS

The potential of Chinese medicine as new kind of photosensitizer and its possibility for use in anticancer photodynamic therapy are existed.

High intracellular calcium concentrations in transformed lymphoblasts from subjects with bipolar I disorder

OBJECTIVE

Higher basal concentrations of intracellular calcium Ca2+ in platelets and lymphocytes from subjects with bipolar affective disorder than in unipolar depressed and healthy subjects implicate abnormal intracellular Ca2+ signaling in bipolar disorder. The purpose of this study was to clarify whether these intracellular Ca2+ abnormalities are trait related.

METHOD

Basal Ca2+ concentration was measured by using ratiometric fluorescence assay with fura-2 for T lymphocytes and Epstein-Barr-virus-immortalized B lymphoblasts from physically healthy subjects with DSM-IV diagnoses of bipolar mood disorder (bipolar I, N = 28; bipolar II, N = 11) or major depressive disorder (N = 14), mixed psychiatric patients with non-mood disorders (N = 14), and health subjects (N = 20). Phytohemagglutinin-stimulated (10 micrograms/ml) intracellular Ca2+ levels were also determined in T lymphocytes.

RESULTS

The basal Ca2+ concentration was significantly higher in the B lymphoblasts from patients with bipolar I disorder, but not bipolar II disorder or major depression, than in healthy subjects or psychiatric patients with nonmood disorders. There was a significant interaction between gender and diagnosis in the effect on basal Ca2+ levels in T lymphocytes. Contrasts of diagnoses within gender revealed significantly higher basal Ca2+ concentrations in T lymphocytes in male bipolar I patients, but not mean with bipolar II disorder or major depression, than in healthy male comparison subjects. Phytohemagglutinin-stimulated Ca2+ concentrations did not differ among groups, but the percent differences from basal Ca2+ levels were lower in bipolar I and depressed patients than in healthy subjects.

CONCLUSIONS

These findings support the occurrence of abnormal calcium homeostasis in bipolar disorder and suggest that trait-dependent factors account, at least partly, for the higher basal lymphocyte Ca2+ concentration in bipolar I subjects.