Loss of yata, a novel gene regulating the subcellular localization of APPL, induces deterioration of neural tissues and lifespan shortening

Background

The subcellular localization of membrane and secreted proteins is finely and dynamically regulated through intracellular vesicular trafficking for permitting various biological processes. Drosophila Amyloid precursor protein like (APPL) and Hikaru genki (HIG) are examples of proteins that show differential subcellular localization among several developmental stages.

Methodology/Principal Findings

During the study of the localization mechanisms of APPL and HIG, we isolated a novel mutant of the gene, CG1973, which we named yata. This molecule interacted genetically with Appl and is structurally similar to mouse NTKL/SCYL1, whose mutation was reported to cause neurodegeneration. yata null mutants showed phenotypes that included developmental abnormalities, progressive eye vacuolization, brain volume reduction, and lifespan shortening. Exogenous expression of Appl or hig in neurons partially rescued the mutant phenotypes of yata. Conversely, the phenotypes were exacerbated in double null mutants for yata and Appl. We also examined the subcellular localization of endogenous APPL and exogenously pulse-induced APPL tagged with FLAG by immunostaining the pupal brain and larval motor neurons in yata mutants. Our data revealed that yata mutants showed impaired subcellular localization of APPL. Finally, yata mutant pupal brains occasionally showed aberrant accumulation of Sec23p, a component of the COPII coat of secretory vesicles traveling from the endoplasmic reticulum (ER) to the Golgi.

Conclusion/Significance

We identified a novel gene, yata, which is essential for the normal development and survival of tissues. Loss of yata resulted in the progressive deterioration of the nervous system and premature lethality. Our genetic data showed a functional relationship between yata and Appl. As a candidate mechanism of the abnormalities, we found that yata regulates the subcellular localization of APPL and possibly other proteins.

N-cadherin-based adhesion enhances Abeta release and decreases Abeta42/40 ratio

In neurons, Presenilin 1(PS1)/gamma-secretase is located at the synapses, bound to N-cadherin. We have previously reported that N-cadherin-mediated cell-cell contact promotes cell-surface expression of PS1/gamma-secretase. We postulated that N-cadherin-mediated trafficking of PS1 might impact synaptic PS1-amyloid precursor protein interactions and Abeta generation. In the present report, we evaluate the effect of N-cadherin-based contacts on Abeta production. We demonstrate that stable expression of N-cadherin in Chinese hamster ovary cells, expressing the Swedish mutant of human amyloid precursor protein leads to enhanced secretion of Abeta in the medium. Moreover, N-cadherin expression decreased Abeta(42/40) ratio. The effect of N-cadherin expression on Abeta production was accompanied by the enhanced accessibility of PS1/gamma-secretase to amyloid precursor protein as well as a conformational change of PS1, as demonstrated by the fluorescence lifetime imaging technique. These results indicate that N-cadherin-mediated synaptic adhesion may modulate Abeta secretion as well as the Abeta(42/40) ratio via PS1/N-cadherin interactions.

Comparison of Plasma Metabolite Concentrations and Enzyme Activities in Beef Cattle Raised by Different Feeding Systems in Korea, Japan and New Zealand

Concentrations of metabolites and immunoreactive insulin (IRI) and activities of enzymes related to energy metabolism were measured in plasma of Korean and Japanese beef cattle, which were raised by the indoor feeding system programmed to feed larger amount of roughage in their growing periods and larger amount of concentrate diet in their finishing periods (Japanese feeding system), and grazing New Zealand beef cattle. By the Japanese beef grading system, Korean and Japanese beef cattle showed high beef quality score, average grade 3.3 and 3.6, respectively. The plasma free fatty acid and lactate concentrations and lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and aspartate aminotransferase (AST) activities in Korean beef cattle were significantly higher than those in Japanese beef cattle. The plasma lactate concentration in Korean beef cattle was 8.40 mmol/l, which was similar to the values observed in lactic acidosis. The higher activities of plasma LDH, MDH and AST may indicate slight liver damage by slightly acidotic conditions in Korean beef cattle. New Zealand beef cattle fed on pasture which they harvest by grazing showed significantly lower plasma glucose, cholesterol, lactate and IRI concentrations and enzyme activities than those in Korean and Japanese beef cattle fed on larger amount of concentrate diets. Plasma metabolite concentrations and energy metabolism-related enzyme activities may be good indicators for evaluating metabolic conditions of beef cattle raised by different feeding systems.

Hochu-ekki-to inhibits rhinovirus infection in human tracheal epithelial cells

BACKGROUND AND PURPOSE

A traditional Japanese herbal medicine, hochu-ekki-to, has been used for the symptomatic treatment of the common cold and to reduce the frequency of colds in patients with chronic obstructive pulmonary disease. However, the inhibitory effects of hochu-ekki-to on infection by rhinovirus (RV), the major cause of common colds, have not been studied.

EXPERIMENTAL APPROACH

Human tracheal epithelial cells in culture were infected with a major group rhinovirus-RV14. Virus output and viral RNA were measured along with interleukin (IL)-1beta, IL-6, IL-8 and tumor necrosis factor (TNF)-alpha), mRNA for intercellular adhesion molecule (ICAM)-1 and acidic endosomes in cells.

KEY RESULTS

RV14 infection increased virus titers, the content of cytokines in supernatants and RV14 RNA in the cells. Hochu-ekki-to decreased virus output, RV14 RNA in the cells, susceptibility to RV infection and supernatant cytokine concentrations after RV14 infection. Hochu-ekki-to reduced mRNA for ICAM-1, the receptor for RV14, the concentration of the soluble form of ICAM-1 and the number and fluorescence intensity of acidic endosomes in the cells, from which RV RNA enters into the cytoplasm, at RV14 infection. Glycyrrhizin, one of the chemical constituents of hochu-ekki-to, reduced supernatant virus titers dose-dependently.

CONCLUSION AND IMPLICATIONS

Hochu-ekki-to inhibited RV14 infection by decreasing ICAM-1 and by blocking entry of viral RNA into the cytoplasm from the endosomes, in airway epithelial cells. Glycyrrhizin may be partly responsible for inhibition of RV infection by hochu-ekki-to. Hochu-ekki-to could modulate airway inflammation by reducing production of cytokines in RV infections.

163 FUNCTIONAL COMPARISON OF BOVINE TROPHOBLASTIC VESICLES DERIVED FROM FRESHLY COLLECTED CONCEPTUSES AND SERIALLY PASSAGED TROPHOBLAST CELLS

The co-transfer of trophoblastic vesicles (TVs), derived from in vivo-recovered conceptuses, is a well-known method for promoting the successful implantation of embryos through the action of bovine interferon-tau (bIFN-τ) on maternal-fetal recognition. However, the preparation of these TVs is a tedious process. Techniques have progressed for obtaining large numbers of TVs consistently from serially passaged trophoblast cells. The aim of the present study was to compare the function of TVs for co-transfer derived from in vitro production with those derived from in vivo-flushed embryos, and without co-transfer. Production of TVs from serially passaged trophoblast cells was carried out according to the method previously described by Takahashi et al. (2000, Cloned animals and placentation, 147–151, Yokendo: Tokyo, Japan). The in vitro TVs (IVP-TVs), 1–2 mm in diameter, were taken from cells passaged 48th to 52th and 96th. In vivo-derived TVs (vivo-TVs) were prepared from recovered elongating blastocysts 7 days after transfer of frozen–thawed embryos on Day 8 of the estrous cycle. Demi-embryos were produced from fresh embryos of flushed Japanese Black cows by bisection using a micromanipulator. Pairs of demi-embryos, without (control) or with 2 to 4 TVs, were transferred into the uterus ipsilateral of 65 Japanese Short Horn recipients to the functional corpus luteum. Pregnancy diagnoses were performed twice, from Day 30 to 70, by ultrasound scanning. BIFN-τ content of culture media was measured by RIA (Takahashi et al. 2005 Theriogenology 63, 1050–1060). Data were analyzed by chi-square test and Fisher's exact test. The pregnancy rate in the IVP-TVs group (20.0%, 5/25) had a tendency to be lower than in the vivo-TVs (46.2%, 6/13), although this did not reach statistical significance (P = 0.09). These pregnant animals were transferred TVs from passaged 48th-52nd (5/19). In the control group 33.3% (9/27) of recipients conceived. Twin pregnancy rate was also lower in the IVP-TVs (0/5) than in the other two groups (3/6 and 5/9, P = 0.09 and P = 0.04, respectively). Fetal losses occurred only in the single pregnancies of IVP-TVs (60.0%, 3/5) and vivo-TVs (16.7%, 1/6) up until Day 70. Reproductive efficiency, based on numbers of delivered offspring, was significantly lower in the IVP-TVs (8%, 2/25) compared with the vivo-TVs (61.5%, 8/13) and control (51.9%, 14/27) groups, respectively (P < 0.01). BIFN-τ levels secreted from the TVs derived from passages 46th and 48th were 0.157 ng/mL-1 and 0.113 ng/mL-1, respectively. In conclusion, compared with the in vivo TVs, those from serially passaged trophoblast cells had a negative effect on pregnancy, although the morphology of the two differently derived TVs was similar.

Arterial blood carboxyhemoglobin as a predictor for response after chemotherapy in patients with lung cancer

20029

Background: It is desirable to predict the response to chemotherapy in patients with lung cancer using a simple and reliable method. Arterial blood carboxyhemoglobin concentration (Hb-CO) is a useful biomarker for severity in inflammatory pulmonary diseases and is associated with cancer tissue volume in operable NSCLC. However, arterial Hb-CO as a predictor for response to chemotherapy in advanced lung cancer has not been reported. Methods: We enrolled 35 patients with SCLC and 66 ones with NSCLC in stage III or stage IV, treated with chemotherapy between October 2000 and December 2002. All patients with SCLC were treated with PE (cisplatin 80 mg/m2, day 1 and etoposide 100 mg/m2, day 1-day 3) every 3 weeks. The patients with NSCLC were treated with either VC (vinorelbine 25 mg/m2, day 1 and 8 plus cisplatin 80 mg/m2, day 1) or DG (gemcitabine 1100 mg/m2, day 1 and day 8 plus docetaxel 60 mg/m2, day 1) every 3 weeks. Arterial Hb-CO were examined before and at during chemotherapy and the response rate were studied. The patients with either a partial response (PR) or a complete response (CR) were categorized as responder, whereas patients with no change (NC) or progressive disease (PD) were as non-responders. According to the analysis in aterial Hb-CO, the patients were divided into two subgroups, patients with high (≥0.3%) or low (<0.3%) maximum changes in the Hb-CO (ΔHb-CO) during chemotherapy. Results: The response rate was 80% in SCLC and 38% in NSCLC. In responder patients with SCLC or NSCLC, the arterial Hb-CO significantly increased and reached maximum at day 4 of the 1st cycle of chemotherapy. In contrast, in non-responder patients, the Hb-CO did not increase during the chemotherapy. The response rate in patients with high ΔHb-CO was significantly higher than that with low ΔHb-CO in SCLC (26/26 vs 2/9, P < .001) and NSCLC (24/24 vs 1/42, P < .001). The high ΔHb-CO at day 4 of the 1st chemotherapy cycle was significantly associated with the response to the chemotherapy in SCLC (Odd ratio, OR = 12.5 [95% CI: 3.13–50, P < .001]) and in NSCLC (OR = 25 [95% CI: 3.23–100, P < .01]) (logistic regression analysis). Conclusions: Increases in arterial Hb-CO at day 4 of the 1st chemotherapy cycle in SCLC and SCLC may be a predictor of response to chemotherapy.

No significant financial relationships to disclose.

A randomized phase II trial comparing carboplatin pleurodesis with cisplatin pleurodesis in patients with stage IIIB/IV non-small cell lung cancer (NSCLC) with malignant pleural effusions (MPE)

17012

Background: We previously reported that carboplatin pleurodesis in patients with advanced lung adenocarcinoma with MPE, renal insufficiency, and poor performance status (PS) was an effective palliative therapy. However, the efficacy and toxicity profile of carboplatin pleurodesis in patients with NSCLC with MPE in comparison with those of cisplatin pleurodesis have not been reported. Methods: Thirty patients with stage IIIB/IV NSCLC accompanied with MPE who did not have an indication for systemic chemotherapy because of poor PS more than 2 were randomized to carboplatin pleurodesis (target area under the curve as 5 μg-min/ml using Calvert’s formula) and cisplatin pleurodesis (80 mg/m2) in a single-blind and controlled trial. Enrollment took place between Oct 2004 and Dec 2005. Primary efficacy endpoints were the best confirmed response rate, time to progression (TTP) in controlling MPE and adverse effects. Results: Fifteen of 30 patients were treated by carboplatin pleurodesis, and resting 15 of 30 patients were treated by cisplatin pleurodesis to control MPE. The response rate in carboplatin pleurodesis was not statistically different from that for patients in cisplatin pleurodesis (P = .226). The use of anticancer drugs for pleurodesis was not significantly associated with response rate in logistic regression analysis (relative risk = 14.2, 95% CI: 0.6–320.5, P = .095). Median TTP in carboplatin pleurodesis was not different from that in cisplatin pleurodesis (96 days vs 83 days). The use of carboplatin for pleurodesis (P = .016) and gender (P = .005) were associated with prolongation of TTP in the Cox regression method. Kaplan-Meier analysis showed that the progression free probability curve in carboplatin pleurodesis was not different from that in cisplatin pleurodesis (P = .275). The rate of Grade 3 thrombocytopenia in carboplatin pleurodesis (25%) was higher than that in cisplatin pleurodesis (0%), but there was no statistical significance (P = .096). Conclusions: Carboplatin pleurodesis and cisplatin pleurodesis may be feasible and acceptable toxicity profiles.

No significant financial relationships to disclose.

Association of susceptibility to the development of pneumonia in the older Japanese population with haem oxygenase-1 gene promoter polymorphism

BACKGROUND

Oxidative stresses including cigarette smoking are implicated in the pathogenesis of cerebrovascular diseases, which are associated with pneumonia because of frequent aspiration. Haem oxygenase-1 (HO-1) acts in cytoprotection against oxidants, provides anti-inflammatory effects, and inhibits atherogenesis. A (GT)(n) dinucleotide repeat in the human HO-1 promoter modulates HO-1 gene expression and shows length polymorphism, which is grouped into three classes: class S (<27 repeats), class M (> or = 27, <33 repeats), and class L (> or = 33 repeats) alleles.

OBJECTIVE

To investigate the correlation between the HO-1 gene polymorphism and development of pneumonia in elderly Japanese.

METHODS

The length of the (GT)n repeats was analysed in 200 elderly patients with pneumonia and 200 control subjects. The association of the HO-1 gene polymorphism with risk of pneumonia was estimated by logistic regression.

RESULTS

The proportion of allele frequencies in class L, and the proportion of genotypic frequencies in the L-allele carriers (L/L, L/M, and L/S), was significantly higher in patients with pneumonia than in controls (20% v 10% in class L, and 34% v 18% in L-allele carriers). After adjustment for potentially confounding factors, both cerebrovascular disorders and HO-1 gene L-allele carriers were significant and independent risk factors for pneumonia. The adjusted odds ratio for L-allele carriers v non-L-allele carrier was 2.1 (95% confidence interval, 1.2 to 3.6).

CONCLUSIONS

The large size of a (GT)n repeat in the HO-1 gene promoter may be associated with susceptibility to pneumonia in the older Japanese population.

Gastric mucosal hyperplasia via upregulation of gastrin induced by persistent activation of gastric innate immunity in major histocompatibility complex class II deficient mice

BACKGROUND AND AIMS

Major histocompatibility complex class II deficient (Aalpha0/0) mice have decreased CD4+ T cells, making them immunologically similar to patients with acquired immunodeficiency syndrome (AIDS). Both patients with AIDS and Aalpha0/0 mice have hypertrophic gastric folds. To clarify the mechanism of gastric mucosal hyperplasia, we investigated the pathophysiology and the role of the innate immunity in the stomach of Aalpha0/0 mice.

METHODS

Stomachs from 1-6 month old Aalpha0/0 mice, kept under specific pathogen free conditions, were examined at 1 month intervals histologically and immunohistochemically. Gene expression of proinflammatory cytokines, Toll-like receptors (TLRs), cyclooxygenase (COX)-2, and myeloperoxidase (MPO) activity in the gastric mucosa was investigated. Serum gastrin levels and gastric acidity were measured. Bacterial culture of the stomach was performed. To clarify the roles of hypergastrinaemia in the gastric mucosa, a gastrin receptor antagonist (AG041R) was administered.

RESULTS

Aalpha0/0 mice had a diffusely thick corpus mucosa with infiltration of CD11b+ granulocytes and macrophages. Anti-Ki67 staining demonstrated expansion of the proliferating neck zone. Gene expression of interleukin 1beta, interferon gamma, TLR-2, TLR-4, and COX-2 were upregulated, and MPO activity was increased. Only a small amount of non-pathogenic bacteria was detected in the stomach. Serum gastrin levels and Reg-Ialpha positive cells in the gastric mucosa increased, despite normal gastric acidity. After treatment with AG041R, gastric mucosal thickness was significantly reduced.

CONCLUSION

Persistent activation of innate immunity in the stomach induced gastric mucosal hyperplasia through upregulation of gastrin synthesis in Aalpha0/0 mice, suggesting a pathophysiology similar to the gastric changes in patients with AIDS.

Antiapoptotic function of 17AA(+)WT1 (Wilms' tumor gene) isoforms on the intrinsic apoptosis pathway

The WT1 gene is overexpressed in human primary leukemia and a wide variety of solid cancers. The WT1 gene is alternatively spliced at two sites, yielding four isoforms: 17AA(+)KTS(+), 17AA(+)KTS(-), 17AA(-)KTS(+), and 17AA(-)KTS(-). Here, we showed that 17AA(+)WT1-specific siRNA induced apoptosis in three WT1-expressing leukemia cell lines (K562, HL-60, and Kasumi-1), but not in WT1-non-expressing lymphoma cell line (Daudi). 17AA(+)WT1-specific siRNA activated caspase-3 and -9 in the intrinsic apoptosis pathway but not caspase-8 in the extrinsic one. On the other hand, 17AA(-)WT1-specific siRNA did not induce apoptosis in the three WT1-expressing cell lines. The apoptosis was associated with activation of proapoptotic Bax, which was activated upstream of the mitochondria. Constitutive expression of 17AA(+)WT1 isoforms inhibited apoptosis of K562 leukemia cells induced by apoptosis-inducing agents, etoposide and doxorubicin, through the protection of mitochondrial membrane damages, and DNA-binding zinc-finger region of 17AA(+)WT1 isoform was essential for the antiapoptotic functions. We further studied the gene(s) whose expression was altered by the expression of 17AA(+)WT1 isoforms and showed that the expression of proapoptotic Bak was decreased by the expression of 17AA(+)KTS(-)WT1 isoform. Taken together, these results indicated that 17AA(+)WT1 isoforms played antiapoptotic roles at some points upstream of the mitochondria in the intrinsic apoptosis pathway.

Carbocisteine inhibits rhinovirus infection in human tracheal epithelial cells

The aim of the study was to examine the effects of a mucolytic drug, carbocisteine, on rhinovirus (RV) infection in the airways. Human tracheal epithelial cells were infected with a major-group RV, RV14. RV14 infection increased virus titres and the cytokine content of supernatants. Carbocisteine reduced supernatant virus titres, the amount of RV14 RNA in cells, cell susceptibility to RV infection and supernatant cytokine concentrations, including interleukin (IL)-6 and IL-8, after RV14 infection. Carbocisteine reduced the expression of mRNA encoding intercellular adhesion molecule (ICAM)-1, the receptor for the major group of RVs. It also reduced the supernatant concentration of a soluble form of ICAM-1, the number and fluorescence intensity of acidic endosomes in the cells before RV infection, and nuclear factor-kappaB activation by RV14. Carbocisteine also reduced the supernatant virus titres of the minor group RV, RV2, although carbocisteine did not reduce the expression of mRNA encoding a low density lipoprotein receptor, the receptor for RV2. These results suggest that carbocisteine inhibits rhinovirus 2 infection by blocking rhinovirus RNA entry into the endosomes, and inhibits rhinovirus 14 infection by the same mechanism as well as by reducing intercellular adhesion molecule-1 levels. Carbocisteine may modulate airway inflammation by reducing the production of cytokines in rhinovirus infection.

Identification of a gene element essential for leukemia-specific expression of transgenes

Leukemia-specific promoters and enhancers for gene therapy had never been reported. Since the Wilms' tumor gene WT1 is overexpressed in almost all types of leukemia, WT1 is an ideal target of leukemia-specific therapy. To explore the possibility of gene therapy for leukemia using WT1 promoter and enhancer, their activities in several kinds of cells were analyzed by using the enhanced green fluorescent protein (EGFP) gene as a reporter. First, we identified the best combination (654P/EGFP/int3- enh/3'-enh vector) of the 654-bp WT1 promoter and the two WT1 enhancers located in intron 3 and at the 3' end of the WT1 gene for inducing EGFP expression in K562 cells, which endogenously expressed WT1. When this was transfected into WT1-expressing leukemia cells (K562, HEL), WT1-nonexpressing hematopoietic cells (Daudi, U937), and WT1-expressing nonhematopoietic cells (TYK-nu-CPr, SW480, 293 T), 19.8, 22.9, 1.47, 1.43, 4.50, 4.16, and 1.09 times EGFP expression was induced, respectively, compared to that by the promoter-less EGFP vector. These results showed that the 654P/EGFP/int3-enh/3'-enh vector specifically induced high levels of EGFP expression in WT1-expressing leukemia cells. 654P/int3- enh/3'-enh vector containing transgenes such as suicide genes might become useful tools for leukemia-specific gene therapy.

335EFFECT OF PATERNAL LINE OF DONOR ON SUPEROVULATORY RESPONSE AND EMBRYO QUALITY IN JAPANESE BLACK HEIFERS

The objective of this study was to investigate the effect of paternal line of donor on superovulatory response and embryo quality in Japanese Black cattle. Japanese Black cattle have paternal lines that can be classified into the following, according to meat quality and the growth rate: ‘high marbling meat type’, ‘high growth rate type’ and ‘high marbling meat and high growth rate (intermediate type)’. We hypothesized that paternal line of donor may affect superovulatory response. One hundred and forty superstimulations were performed on 56 Japanese Black heifers, and data on superovulatory response and embryo collection were analyzed. Japanese Black donors used in this study were from the following 4 paternal lines: Kedaka (large-framed with high growth rate;; n=9, 30 times), Fujiyoshi (intermediate type;; n=22, 47 times), Shigekane (high marbling meat type;; n=13, 40 times), and Tajiri (high marbling meat type and small-frame with slow growth rate;; n=12, 23 times). Donors were synchronized using a CIDR-B (EAZI-BREED, InterAg, NZ) for 8 to 12 days, and 500μg PGF analog (Resipron-C; Teikoku Zouki, Japan or Clopromate-C; Sumitomo, Japan) administered at CIDR removal. Superstimulation was initiated on Day 10 (Day 0=day of estrus) of the synchronized cycle;; FSH (Antrin R10;; Denka, Japan) was administered twice daily for 4 days with decreasing doses for a total of 28 Armour units FSH. PGF analog was administered in the morning on the last day of FSH treatment. Donors were given 50 or 100μg GnRH analog (Sporunen, Denka, or Conceral, Takeda Schering prau, Japan) at the time of estrus detection, and were inseminated 12h after the onset of estrus. Embryos were recovered on Day 7 after AI. The numbers of CL and follicles were recorded with transrectal ultrasonography immediately after embryo recovery. Embryos were classified according to the IETS Manual. Data were analyzed by Kruskal-Wallis test combined with Scheffe’s multiple comparison test. There were no significant differences in CL numbers among paternal lines: Kedaka (9.5±4.2), Fujiyoshi (8.5±5.1), Shigekane (7.8±5.0) and Tajiri (8.6±4.1). Mean number of recovered ova/embryos per donor was significantly (P&lt;0.05) higher in the Kedaka line (8.4±5.1) than in the Fujiyoshi (4.9±4.1) and Shigekane (5.5±7.0) lines. The percentages of viable embryos was greater (P&lt;0.05) in the Fujiyoshi (73.7%) and Shigekane lines (62.8%) than in the Tajiri line (50.9%), whereas the percentage of unfertilized oocytes was significantly (P&lt;0.05) higher in the Tajiri line (41.5%) than in the Fujiyoshi (17.5%) or Shigekane (26.1%) lines. The percentages of freezeable and transferable embryos were not significantly different among paternal lines. Data suggest that the paternal line had an effect on the superstimulatory response in Japanese Black heifers, and especially the number and percentage of viable embryos per donor.