Population-based, three-dimensional analysis of age- and sex-related femur shaft geometry differences

This study deals with differences of femoral geometric focus on the bowing and width. Analysis using three-dimensional skeletonization showed increase of femoral bowing and femur width over life (more in women), and widening of the medullary canal only in women after 50 years old, not in men.

INTRODUCTION

The changes in femur geometry that occur with aging and lead to fragility or insufficiency fracture remain unclear. The role of the lower limb geometry, including the femur and femoral bowing, has become a point of discussion, especially in atypical femur fracture. This study aimed to analyze femur shaft geometry using three-dimensional skeletonization.

METHODS

We acquired computed tomography images of both femurs obtained. A total of 1400 age- and sex-stratified participants were enrolled and were divided into subgroups according to age (by decade) and sex. The computed tomography images were used to produce 3-dimensional samplings of anatomical elements of the human femur using reconstruction and parametrization from these datasets. The process of skeletonization was conducted to obtain compact representation of the femur. With the skeletonization, we were able to compare all parameters according to age and sex.

RESULTS

The femur length was 424.4 ± 28.6 mm and was longer in men (P < 0.001). The minimum diameter of the medullary canal was 8.9 ± 2.0 mm. The radius of curvature (ROC) was 906.9 ± 193.3 mm. Men had a larger femur length, femur outer diameter, and the narrowest medullary diameter (P < 0.001, respectively). Women had significantly smaller ROC (P < 0.001). ROC decreased by 19.4% in men and 23.6% in women between the ages of 20 to 89 years. Femur width increased over life by 11.4% in men and 24.5% in women. Between the ages of 50 and 89 years, the medullary canal appears to have increased by 32.7% in women.

CONCLUSION

This geometry analysis demonstrated that femoral bowing and femoral width increased related to aging, and that the medullary canal widened after the age of 50 years in women. This cross-sectional study revealed important age- and sex-related differences in femur shaft geometry that occur with aging.

Demetylation of the sex-determining region Y gene promoter and incidence of disorder of sex development in cloned dog males

Canine cloning is occasionally accompanied by abnormal sexual development. Some male donor cells produce cloned pups with female external genitalia and complete male gonadal dysgenesis, which is classified as an XY disorder of sex development (XY DSD). In this study, we examine the potential of 5-aza-2'-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to reduce the phenotypic abnormality XY DSD in somatic cell nuclear transfer (SCNT)- derived pups. We used a 9-year-old normal male German Shepherd dog as a cell donor. Donor cells were treated with 10 nM 5-aza-dC for 4 days before being used for SCNT. At the same stage of cell development, significantly lower levels of DNA methylation of the sex-determining region Y (SRY) promoter was observed in the treated donor cells compared to that in the untreated cells (95.2% versus 53.3% on day 4 for the control and treated groups, respectively). No significant differences were observed in the control or treatment groups concerning fusion rate, pregnancy rate (30 days or entire period), the number of pups, or the incidence of XY DSD. However, more XY DSD dogs were observed in the control group (31.25%) than in the treatment group (14.29%). Hypermethylation of the SRY promoter was observed in the XY DSD cloned pups in both the treatment (84.8%) and control groups (91.1 ± 1.4%) compared to the methylation level in the phenotypically normal male pups of the treatment (23.2 ± 20.9%) and control groups (39.1 ± 20.1%). These results suggest that 5-aza-dC treatment of donor cells can reduce the methylation level of the SRY promoter in donor cells, and thus, 5-aza-dC is advantageous for reducing the incidence of XY DSD in canine cloning.

Parkin expression reverses mitochondrial dysfunction in fused in sarcoma-induced amyotrophic lateral sclerosis

Fused in sarcoma (FUS) is a DNA/RNA-binding protein associated with amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration. The exact molecular mechanisms by which FUS results in neurotoxicity have not yet been fully elucidated. Here, we found that parkin is a genetic suppressor of defective phenotypes induced by exogenous human wild type FUS in Drosophila. Although parkin overexpression did not modulate the FUS protein expression level, the locomotive defects in FUS-expressing larvae and adult flies were rescued by parkin expression. We found that FUS expression in muscle tissues resulted in a reduction of the levels and assembly of mitochondrial complex I and III subunits, as well as decreased ATP. Remarkably, expression of parkin suppressed these mitochondrial dysfunctions. Our results indicate parkin as a neuroprotective regulator of FUS-induced proteinopathy by recovering the protein levels of mitochondrial complexes I and III. Our findings on parkin-mediated neuroprotection may expand our understanding of FUS-induced ALS pathogenesis.

The HLA-A*33:110 allele identified in a volunteer donor for hematopoietic stem cell transplant

HLA-A*33:110 differs from HLA-A*33:03:01:01 in a codon 149 in exon 3.

The HLA-B*46:67 allele identified in a volunteer donor for hematopoietic stem cell transplant

HLA-B*46:67 differs from HLA-B*46:01:01 in codons 94, 95, and 103 in exon 3.

The HLA-B*54:35 and -B*54:38 identified in volunteer donors for hematopoietic stem cell transplant

HLA-B*54:35 and -B*54:38 differ from HLA-B*54:01:01 in codons in exons 2 and 3.

The HLA-B*15:400N allele identified in a volunteer donor for hematopoietic stem cell transplant

HLA-B*15:400N differs from HLA-B*15:01:01:01 by nucleotide deletions from position 328 to 331 in exon 3.

The HLA-B*58:01:20 allele identified in a volunteer donor for hematopoietic stem cell transplant

HLA-B*58:01:20 differs from HLA-B*58:01:01:01 by a single synonymous nucleotide exchange at position 297 in exon 3.

The HLA-A*26:132 allele identified in a volunteer donor for hematopoietic stem cell transplant

HLA-A*26:132 differs from HLA-A*26:01:01:01 at nucleotides 269 and 346 in exons 2 and 3.

Efficacy and safety of non-invasive body tightening with high-intensity focused ultrasound (HIFU)

BACKGROUND

Noninvasive skin-tightening devices have become increasingly popular in response to increasing demand for improvements in skin laxity and tightening with minimal risk and recovery time.

OBJECTIVE

We evaluated the efficacy and safety of HIFU for skin tightening in the face and body.

METHODS

A total of 32 Korean subjects enrolled in this prospective clinical trial. The subjects were treated with HIFU to both cheeks, lower abdomen, and thigh. Skin elasticity was measured before and after treatment using a Cutometer (CT575, Courage and Khazaka^® , Cologne, Germany). Three blinded, experienced dermatologists evaluated paired pre- and post-treatment (week 4 and 12) photographs according to the Global Aesthetic Improvement Scale (GAIS). Participants also completed self-assessments using GAIS. Subjects rated their pain on a numeric rating scale (NRS) immediately, 7 days, 4 weeks, and 12 weeks after treatment.

RESULTS

Skin elasticity measured via a Cutometer was significantly improved 12 weeks after treatment at all treated sites (P<.05). Both IGAIS and SGAIS showed significant improvements 12 weeks after treatment. Immediately after treatment the mean NRS score was 3.00±1.586, but no pain was reported at 4 and 12 weeks post-treatment. No serious adverse effects were observed during the follow-up period.

CONCLUSION

HIFU safely and effectively improves skin elasticity and clinical contouring of the face and body.

A clinical drug library screen identifies clobetasol propionate as an NRF2 inhibitor with potential therapeutic efficacy in KEAP1 mutant lung cancer

The Kelch-like ECH-associated protein 1 (KEAP1)-nuclear factor E2-related factor 2 (NRF2)pathway has a central role in cellular antioxidant defense. NRF2 activation due to KEAP1 or NRF2 mutations occurs frequently in many cancers, suggesting that NRF2 inhibition could be a promising therapeutic strategy. However, no potent NRF2 inhibitors are clinically available to date. To develop potent NRF2 inhibitors for therapeutic purpose, we screened ~4000 clinical compounds and determined clobetasol propionate (CP) as the most potent NRF2 inhibitor. Mechanistically, CP prevented nuclear accumulation and promoted β-TrCP-dependent degradation of NRF2 in a glucocorticoid receptor- and a glycogen synthase kinase 3 (GSK3)-dependent manner. As a result, CP induced oxidative stress and strongly suppressed the anchorage-independent growth of tumors with KEAP1 mutation, but not with the wild-type KEAP1. Further, CP alone or in combination with rapamycin strongly inhibited the in vitro and in vivo growth of tumors harboring mutations in KEAP1 or both KEAP1 and LKB1 that are frequently observed in lung cancer. Thus, CP could be a repurposed therapeutic agent for cancers with high NRF2 activity. We also proposed that the use CP and rapamycin in combination could be a potential therapeutic strategy for tumors harboring both KEAP1 and LKB1 mutations.

Suppressor of Cytokine Signaling 3 Expression Induced by Varicella-Zoster Virus Infection Results in the Modulation of Virus Replication

Varicella-zoster virus (VZV) is an important viral pathogen that is responsible for causing varicella (chickenpox) and herpes zoster (shingles). VZV has been shown to suppress early anti-viral innate immune responses, but the exact mechanisms are not yet well understood. Here we demonstrate that host control of VZV is impaired by the expression of suppressor of cytokine signaling (SOCS)3. We used three different cell types to characterize VZV-induced anti-viral and inflammatory responses. Infection of human fibroblasts (MRC-5) and human macrophages (THP-1) with VZV triggered upregulation of anti-viral responsive gene expression (IFN-α, IFN-β) in the early phases of infection, followed by the waning of these IFNs in the late phases of infection. Conversely, VZV infection in keratinocytes (HaCaT) resulted in a persistent increase in type I IFN gene expression. Interestingly, increase in SOCS1 and 3 expressions coincided with a reduction in phosphorylation of the signal transducer and activator of transcription protein 3 (STAT3) in VZV-infected MRC-5 cells. Furthermore, VZV infection increased the production of pro-inflammatory cytokines, including interleukin (IL)-6, -8, and IFN-γ-inducible protein 10 (IP-10). Knockdown of SOCS3 inhibited viral replication and enhanced secretion levels of IL-6, whereas overexpression of SOCS3 did not affect viral replication efficiency and host response. In conclusion, our data suggest that VZV infection induces SOCS3 expression, resulting in modulation of type I IFN signaling and viral replication.

Malva verticillata seed extracts upregulate the Wnt pathway in human dermal papilla cells

OBJECTIVE

Mesenchymal-epithelial interactions are important in controlling hair growth and the hair cycle. The β-catenin pathway of dermal papilla cells (DPCs) plays a pivotal role in morphogenesis and normal regeneration of hair follicles. Deletion of β-catenin in the dermal papilla reduces proliferation of the hair follicle progenitor cells that generate the hair shaft and induces an early onset of the catagen phase. In this study, a modulator of the Wnt/β-catenin activity was studied in oriental herb extracts on cultured human DPCs.

METHODS

The effect of Malva verticillata (M. verticillata) seeds on human DPCs was investigated by a Wnt/β-catenin reporter activity assay system (β-catenin-TCF/LEF reporter gene) and cell proliferation analysis. The synthesis of the factors related to hair growth and cycling was measured at both the mRNA and the protein level by semi-quantitative PCR and Western blot analysis, respectively.

RESULTS

An extract from M. verticillata seeds increased Wnt reporter activity in a concentration-dependent manner and also led to increased β-catenin levels in cultured human DPCs. Myristoleic acid, identified as an effective compound of M. verticillata seeds, stimulated the proliferation of DPCs in a dose-dependent manner and increased transcription levels of the downstream targets: IGF-1, KGF, VEGF and HGF. Myristoleic acid also enhanced the phosphorylation of MAPKs (Akt and p38).

CONCLUSION

Overall, the data suggest that this extract of M. verticillata seeds could be a good candidate for treating hair loss by modulating the Wnt/β-catenin pathway in DPCs.

High intensity focused ultrasound as a potential new modality for the treatment of pigmentary skin disorder

BACKGROUND/PURPOSE

The clinical skin tightening benefits of high intensity focused ultrasound (HIFU) have been established, but its mechanism of action in pigmented skin disorders remains unknown. We macroscopically and histopathologically investigated dermatological changes after HIFU at different exposure doses in a UVB-induced guinea pig model of hyperpigmentation.

METHODS

We applied HIFU irradiation at 0.1 and 0.2 J/cm(2) to UVB-induced spotty hyperpigmentation in guinea pig skin. The therapeutic effects of HIFU were judged based on gross appearance using photography, dermoscopy, and chromametry during a period of 3 weeks after HIFU irradiation. Histological assessments were performed using Fontana-Masson staining 1 day before and 3 weeks after HIFU irradiation.

RESULTS

Macroscopically, UVB-induced hyperpigmentation was significantly reduced 2 weeks after HIFU with 0.2 J/cm(2) , and 3 weeks after HIFU with 0.1 J/cm(2) . Histopathologically, the heavy deposition of melanin in the epidermis induced by UVB exposure was reduced 3 weeks after HIFU irradiation.

CONCLUSION

We confirmed that HIFU has a positive effect on UVB-induced hyperpigmentation as well as mechanical destructive activity. We suggest that HIFU may be useful as an alternative modality for human patients suffering from skin pigmentary conditions.

The effects of 5-hydroxytryptamine1a receptor agonist, buspirone on the gastric fundus accommodation in an animal model using guinea pigs

BACKGROUND

To date, few animal experiments have been conducted to examine the effects and mechanisms of buspirone in inducing the relaxation of the gastric fundus. The aim of this study is to examine the effects and mechanisms of buspirone, 5-HT(1a) receptor agonist, in the accommodation of gastric fundus muscle in an animal experimental model using guinea pigs.

METHODS

In the current study, we performed an immunohistochemistry for 5-HT(1a) receptors in the tissue samples collected from the stomach of guinea pig, an ex vivo experiment to examine the electrical field stimulation (EFS)-induced relaxation of the circular muscle in the gastric fundus in guinea pigs and an in vivo experiment to measure the intragastric pressure through the insertion of the balloon catheter in the fundus.

KEY RESULTS

Immunohistochemical stains for 5-HT(1a) receptor could confirm the expression of 5-HT(1a) receptor in guinea pig stomach. There was a significant dose-dependent inhibition of the EFS-induced relaxation of fundic muscle strips following the treatment with WAY-100635 (5-HT(1a) antagonist), but this was significantly improved following the treatment with buspirone. An in vivo measurement of the gastric fundic tone showed that there was a significant decrease in the intragastric pressure at same volume by pretreatment with buspirone as compared with the vehicle control, but this could be prevented with the treatment with WAY-100635.

CONCLUSIONS & INFERENCES

Based on our results, it can be concluded that buspirone is effective in relaxing the gastric fundus via 5-HT(1a) receptor pathway in both in vitro and in vivo experimental models using guinea pigs.

Microarrays for high-throughput genotyping of MICA alleles using allele-specific primer extension

The role of major histocompatibility complex (MHC) class I chain-related gene A (MICA), a ligand of NKG2D, has been defined in human diseases by its allele associations with various autoimmune diseases, hematopoietic stem cell transplantation (HSCT) and cancer. This study describes a practical system to develop MICA genotyping by allele-specific primer extension (ASPE) on microarrays. From the results of 20 control primers, strict and reliable cut-off values of more than 30,000 mean fluorescence intensity (MFI) as positive and less than 3000 MFI as negative, were applied to select high-quality specific extension primers. Among 55 allele-specific primers, 44 primers could be initially selected as optimal primer. Through adjusting the length, six primers were improved. The other failed five primers were corrected by refractory modification. MICA genotypes by ASPE on microarrays showed the same results as those by nucleotide sequencing. On the basis of these results, ASPE on microarrays may provide high-throughput genotyping for MICA alleles for population studies, disease-gene associations and HSCT.

Improved methods for selective cryolipolysis results in subcutaneous fat layer reduction in a porcine model

BACKGROUND/AIMS

Cryolipolysis is a noninvasive method for the selective reduction of localized fat tissues. It has demonstrated efficacy in both clinical and preclinical trials; however, despite its popularity, its mechanisms of action and evaluation methods are not yet fully defined. The purpose of this study was to improved methods for cryolipolysis using a porcine model.

METHODS

The abdomens of female PWG micro-pigs were treated with a cooling device (CRYOLIPO II(™)), and we examined the treatment effects using photography, three-dimensional photography, ultrasound, gross, and microscopic pathology, and serum lipid level analyses in order to determine the mechanism of action, efficacy, and safety of CRYOLIPO II(™).

RESULTS

CRYOLIPO II(™) successfully reduced abdominal fat in our porcine model. Gross and microscopic histological results confirmed the noninvasive cold-induced selective subcutaneous fat destruction, and showed increases in pre-adipocyte differentiation and in the activation of lipid catabolism. In particular, we found that CRYOLIPO II(™) may increase PPARδ (delta) levels in adipose tissue at 30-60 days post-treatment.

CONCLUSION

Fat reduction by cryolipolysis was successfully achieved in our porcine model. Thus, our findings indicate that CRYOLIPO II(™) may be a promising fat reduction device for body contouring and fat reduction in humans, and that cryolipolysis exerts its effects, at least partly, by targeting the PPARδ signaling pathway. These results show that both investigative and diagnostic potentials capacity.

Primary irritation index and safety zone of cosmetics: retrospective analysis of skin patch tests in 7440 Korean women during 12 years

BACKGROUND

Cosmetics are products used over long periods by the public, and their safety is very important. Several types of human tests are used widely for the evaluation of cosmetics including single patch tests, in-use tests, human repeated insult patch test (HRIPT). However, there is no clear and well-defined published objective and standardized criteria for primary skin irritation in regard to the large variety of cosmetic products.

METHODS

This study analysed human patch tests conducted from May 2001 to December 2012 with 4606 materials of prototype or finished cosmetic products on 7440 normal Korean women aged 18-60 years. The tested products were patched under occlusion for 24 or 48 h, and skin tolerance was assessed twice at 30 min and 24 h after patch removal using a 5-step scale according to the CTFA guidelines.

RESULTS

Human patch tests for cosmetics were performed of 4606 cases, and 30-33 subjects participated in each case. The response in each case was calculated based on total subject number, skin reaction intensity and the number of respondents. The calculated response was standardized using the z-score, and a safety zone was provided in terms of human primary irritation in accordance with the human skin reaction evaluation criteria and usage or formula of cosmetics.

CONCLUSIONS

This study established the safety criteria for irritation in the cosmetics field.

Extracellular vesicles, especially derived from Gram-negative bacteria, in indoor dust induce neutrophilic pulmonary inflammation associated with both Th1 and Th17 cell responses

BACKGROUND

Many bacterial components in indoor dust can evoke inflammatory pulmonary diseases. Bacteria secrete nanometre-sized vesicles into the extracellular milieu, but it remains to be determined whether bacteria-derived extracellular vesicles in indoor dust are pathophysiologically related to inflammatory pulmonary diseases.

OBJECTIVE

To evaluate whether extracellular vesicles (EV) in indoor air are related to the pathogenesis of pulmonary inflammation and/or asthma.

METHODS

Indoor dust was collected from a bed mattress in an apartment. EV were prepared by sequential ultrafiltration and ultracentrifugation. Innate and adaptive immune responses were evaluated after airway exposure of EV.

RESULTS

Repeated intranasal application of indoor-dust-induced neutrophilic pulmonary inflammation accompanied by lung infiltration of both Th1 and Th17 cells. EV 50-200 nm in diameter were present (102.5 μg protein concentration/g dust) in indoor dust. These vesicles were internalized by airway epithelial cells and alveolar macrophages, and this process was blocked by treatment of polymyxin B (an antagonist of lipopolysaccharide, an outer-membrane component of Gram-negative bacteria). Intranasal application of 0.1 or 1 μg of these vesicles for 4 weeks elicited neutrophilic pulmonary inflammation. This phenotype was accompanied by lung infiltration of both Th1 and Th17 cells, which were reversed by treatment of polymyxin B. Serum dust EV-reactive IgG1 levels were significantly higher in atopic children with asthma than in atopic healthy children and those with rhinitis or dermatitis.

CONCLUSION & CLINICAL RELEVANCE

Indoor dust EV, especially derived from Gram-negative bacteria, is a possible causative agent of neutrophilic airway diseases.

Infrared conductivity and carrier mobility of large scale graphene on various substrates

It is known that low-field mobility of graphene depends largely on the substrate material on which it is transferred. We measured Drude optical conductivity of graphene on various substrates and determined the carrier density and carrier scattering rate. The carrier density varies widely depending on the substrate material. However the scattering rate is almost constant, approximately 100 cm(-1), for 5 different substrates. We calculate carrier mobility of graphene using the two quantities, i.e., carrier density and scattering rate, to find that it agrees with the mobility measured from dc transport experiment. We conclude that substrate-depent mobility of graphene originates from different carrier density but not from the scattering rate.

Reduction of breast cancer cell migration via up-regulation of TASK-3 two-pore domain K+ channel

AIM

Many kinds of K(+) channels are expressed in a variety of cells, including cancer cells. However, only a small amount of research has explored the relationship between voltage-independent K(+) channels and breast cancer. This study was performed to investigate whether changes in two-pore domain K(+) (K(2P) ) channel expression levels are related to the migration of human breast cancer cells.

METHODS

K(2P) channel gene/protein expression levels were compared between MCF-7 (a non-invasive cell) and MDA-MB-231 (an invasive cell) using reverse transcriptase (RT)-polymerase chain reaction (PCR), real-time PCR, Western blotting and immunocytochemistry. The relationship between K(2P) channel expression level and cell migration was analysed using gene overexpression and knock-down techniques. Functional expression of TASK-3 in MCF-7 and MDA-MB-231 cells was recorded using patch-clamp technique.

RESULTS

Of K(2P) channels, TASK-3 mRNA and protein were highly expressed in MCF-7 cells compared with those in MDA-MB-231 cells. Overexpression of TASK-3 in breast cancer cells reduced migration and invasion, whereas silencing of TASK-3 increased the migration and invasion. The TASK-3 expression level was decreased by phorbol myristate acetate (PMA), a PKC activator. PMA also enhanced the cell migration in MDA-MB-231 cells.

CONCLUSION

These results show that an increase in TASK-3 expression levels, which could be modulated by PKC activation, reduces cell migration/invasion in breast cancer cells and suggest that modulation of TASK-3 expression may regulate metastasis of breast cancer cells.

The effects of methane and hydrogen gases produced by enteric bacteria on ileal motility and colonic transit time

BACKGROUND

Gases produced by intestinal flora may modulate intestinal motor function in healthy individuals as well as those with functional bowel disease. Methane, produced by enteric bacteria in the human gut, is associated with slowed intestinal transit and constipation. The effects of hydrogen, another main gas produced by bacterial fermentation in the gut, on small bowel and colonic motor function remains unrecognized. Therefore, we set out to investigate whether intestinal gases including methane and hydrogen could influence the small bowel motility and colonic transit.

METHODS

Guinea pig ileum was placed in the peristaltic bath with tension transducers attached to measure velocity and amplitude of peristaltic contraction before and after the infusion of control, hydrogen, and methane gases. Also, changes in the intraluminal pressures were monitored before and after the gas infusions.

KEY RESULTS

Methane decreased peristaltic velocity and increased contraction amplitude significantly of guinea pig ileum (P < 0.05). The AUC of intraluminal pressure was significantly increased with methane in guinea pig ileum (P < 0.05). In a second experiment, guinea pig colon was placed in the peristaltic bath to measure transit time before and after control, hydrogen, methane, and methane-hydrogen mixture gas infusions. Hydrogen shortened colonic transit time by 47% in the proximal colon, and by 10% in the distal colon, when compared with baselines (P < 0.05).

CONCLUSIONS & INFERENCES

Methane delayed ileal peristaltic conduction velocity by augmenting contractility. Hydrogen shortened colonic transit, and that effect was more prominent in the proximal colon than distal colon.

A viral PAMP double-stranded RNA induces allergen-specific Th17 cell response in the airways which is dependent on VEGF and IL-6

BACKGROUND

Innate immune response by a viral pathogen-associated molecular pattern dsRNA modulates the subsequent development of adaptive immune responses. Although virus-associated asthma is characterized by noneosinophilic inflammation, the role of Th17 cell response in the development of virus-associated asthma is still unknown.

OBJECTIVE

To evaluate the role of the Th17 cell response and its underlying polarizing mechanisms in the development of an experimental virus-associated asthma.

METHODS

An experimental virus-associated asthma was created via airway sensitization with ovalbumin (OVA, 75 μg) and a low (0.1 μg) or a high (10 μg) doses of synthetic dsRNA [polyinosine-polycytidylic acid; poly(I:C)]. Transgenic (IL-17-, IL-6-deficient mice) and pharmacologic [a vascular endothelial growth factor receptor (VEGFR) inhibitor] approaches were used to evaluate the roles of Th17 cell responses.

RESULTS

After cosensitization with OVA and low-dose poly(I:C), but not with high-dose poly(I:C), inflammation scores after allergen challenge were lower in IL-17-deficient mice than in wild-type (WT) mice. Moreover, inflammation enhanced by low-dose poly(I:C), but not by high-dose poly(I:C), was impaired in IL-6-deficient mice; this phenotype was accompanied by the down-regulation of IL-17 production from T cells from both lymph nodes and lung tissues. Airway exposure of low-dose poly(I:C) enhanced the production of VEGF and IL-6, and the production of IL-6 was blocked by treatment with a VEGFR inhibitor (SU5416). Moreover, the allergen-specific Th17 cell response and subsequent inflammation in the low-dose poly(I:C) model were impaired by the VEGFR inhibitor treatment during sensitization.

CONCLUSIONS

Airway exposure of low-level dsRNA induces an allergen-specific Th17 cell response, which is mainly dependent on VEGF and IL-6.

JIP1 binding to RBP-Jk mediates cross-talk between the Notch1 and JIP1-JNK signaling pathway

Notch1 signaling has a critical function in maintaining a balance among cell proliferation, differentiation, and apoptosis. Our earlier work showed that the Notch1 intracellular domain interferes with the scaffolding function of c-Jun N-terminal kinase (JNK)-interacting protein-1 (JIP1), yet the effect of JIP1 for Notch1-recombining binding protein suppressor of hairless (RBP-Jk) signaling remains unknown. Here, we show that JIP1 suppresses Notch1 activity. JIP1 was found to physically associate with either intracellular domain of Notch1 or RBP-Jk and interfere with the interaction between them. Furthermore, we ascertained that JIP1 caused the cytoplasmic retention of RBP-Jk through an interaction between the C-terminal region of JIP1 including Src homology 3 domain and the proline-rich domain of RBP-Jk. We also found that RBP-Jk inhibits JIP1-mediated activation of the JNK1 signaling cascade and cell death. Our results suggest that direct protein-protein interactions coordinate cross-talk between the Notch1-RBP-Jk and JIP1-JNK pathways.

Evaluation of equol function on anti- or prooxidant status in vivo

The present study was performed to investigate the effects of equol on oxidative stress and the antioxidant defense system in the livers of mice. Mice were orally administered equol at either 5 or 25 mg/kg body weight/day for 1, 3, or 7 wk. Equol administration significantly inhibited biomarkers of oxidative stress (thiobarbituric acid-reactive substances value, carbonyl content, and serum 8-OH-dG) at all doses and for all durations of administration, and this phenomenon was most pronounced at 3 wk. Moreover, catalase and total superoxide dismutase (SOD) activities and their mRNA expression were significantly increased by equol. Although equol increased the glutathione peroxidase (GSH-px) activity in mice treated with equol for 1 wk, long-term administration of equol (7 wk) caused a decrease in the ratio of reduced/oxidized glutathione (GSH/GSSG) and the activities of GSH-px and glutathione reductase (GR). Taken together, these results suggest that equol may act as an antioxidant through an inhibition of oxidative stress and stimulation of catalase and SOD, but can also cause prooxidant effects such as reduction of the GSH/GSSG ratio, depending on the treatment period.

Preparation of biopolymer-coated magnetite nanoparticles for magnetic resonance image contrast agent

The magnetite nanoparticles were synthesized using the sonochemical method with oleic acid as surfactant. The average size of the magnetite particles can be controlled by the ratio R = [H2O]/[surfactant] in the range of 2 to 9 nm. The size of the magnetite nanoparticles prepared by this method shows the narrow distribution. To prepare biopolymer(beta-glucan)-coated magnetite nanoparticles, beta-glucan solution was added to the magnetic colloid suspensions under the ultrasonication at room temperature. The beta-glucan coated magnetite colloidal suspensions of various concentrations did not agglomerate for 15 days, indicating their good stability. The beta-glucan-coated magnetite colloidal suspensions exhibited the enhancement of MRI contrasts in vitro.

Feed contaminated with classical swine fever vaccine virus (LOM strain) can induce antibodies to the virus in pigs

In November 2004, antibodies to classical swine fever virus (csfv) were detected in finishing pigs during the annual serological surveillance in Jeju Province, Korea. In addition, csf vaccine viruses (lom strain) had recently been isolated from pigs raised on farms known to have csfv antibody-positive pigs. In contrast with mainland Korea, Jeju Province had been csf free and its pigs had not been vaccinated against csf for more than five years. An epidemiological investigation team from the National Veterinary Research and Quarantine Service investigated the current status of csf prevention on the Korean mainland and in Jeju Province to determine possible routes of introduction of the virus into the province. It was concluded that improperly processed blood meals, manufactured on mainland Korea, had been contaminated with the csf vaccine lom strain, and that the lom strain had been transmitted to pigs fed feed or feedstuffs containing the contaminated meal.

Comparison between coronal reformatted images and direct coronal CT images of the swine lung specimen: assessment of image quality with 64-detector row CT

The aims of this study were to compare the image quality of coronal multiplanar reconstruction (MPR) images from axial spiral images with that of direct coronal spiral and sequential images, and to estimate and analyse the effect of an incremental change on the image quality using 64-detector row CT. 12 swine lungs were used. Five kinds of images from each lung specimen were obtained using 64-detector row CT. All images were analysed by categories and grades, and the direct coronal sequential images were used as the reference standard for the image quality. Statistical analysis was performed for the following categories: (i) inter-observer reliability, (ii) interaction between the observers and images, (iii) image analysis, (iv) anatomical structural analysis of each observer, (v) stair-step artefact and (vi) background noise. The overall image quality and the image quality of all anatomical structures of coronal MPR images with 0.67 mm slice increments were inferior to the image quality of the other images; this difference was statistically significant (p<0.05). Stair-step artefact was detected on coronal MPR images, and was more prominent on coronal MPR images with 0.67 mm slice increments than on coronal MPR images with 0.34 mm slice increments. The most severe background noise was detected on the direct coronal sequential images, but there was no significant difference between the direct coronal sequential images and the direct coronal spiral images. Background noise was least prominent on coronal MPR images with 0.67 mm slice increments. The increment process is important for improving the image quality of MPR images even when using 64-detector row CT. Coronal MPR images with 0.34 mm slice increments using 64-detector row CT showed a similar image quality to that obtained from the direct coronal images, and can be used instead. This means that the coronal MPR images obtained with 64-detector row CT could be as useful for evaluating the lung parenchyma as the axial high-resolution CT images.

The effect of mosapride citrate on proximal and distal colonic motor function in the guinea-pig in vitro

Mosapride citrate (mosapride), a substituted benzamide, is a selective 5-HT(4) receptor agonist, and is known to have prokinetic properties on the stomach. However, it is unclear whether mosapride also has a prokinetic effect on the colon. We previously found that mosapride significantly shortened colonic transit time in the guinea-pig, an animal with a distribution of colonic 5-HT(4) receptors similar to that of a human. So, we aimed to separately evaluate the effect of mosapride on proximal and distal colonic motor function in the guinea-pig. Proximal (approximately 8 cm from the ileocolic junction) and distal colon (approximately 8 cm from the anus) were removed. Both ends of the colon were connected to a chamber containing a Krebs-Henseleit solution. To measure colonic transit time, artificial faeces were inserted into the oral side of the lumen and moved towards the anal side by intraluminal perfusion via a peristaltic pump. A total of 6 cm of transit was observed and time was measured in 2 cm increments. A tissue bath study, using electrical stimulation, was performed to estimate the contractile activity of the circular musculature of the colon. Immunohistochemical staining for 5-HT(4) receptors was performed in the myenteric plexus and circular muscle in both proximal and distal colon, and the stained area was measured using a microscope and computer software. Mosapride enhanced contraction at 10(-9) to 10(-7) mol L(-1), coinciding with rapid transit both in proximal and distal colon. This pattern was more prominent in proximal colon. At the high dose (10(-6) mol L(-1)) mosapride had little or no effect on colonic contraction. This stimulatory effect was attenuated by GR113808, atropine and tetrodotoxin. In the myenteric plexus, the density of 5-HT(4) receptors was significantly greater in the proximal colon than in the distal colon, but in circular muscle the density was greater in the distal colon. Thus, mosapride accelerates transit through increased contraction in the proximal colon more than distal colon. The different distribution of neuronal and muscular 5-HT(4) receptors may support these findings. Therefore, mosapride may be a useful alternative to tegaserod and cisapride for constipation.

Influence of killer cell immunoglobulin-like receptor genotypes on acute graft-vs-host disease after unrelated hematopoietic stem cell transplantation in Koreans

Interactions between killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen class I ligands influence the development of the natural killer cell repertoire and the responses to infection, cancer, and allogeneic tissue. In this study, the association of KIR genes with acute graft-vs-host disease (GVHD) was investigated in 44 pairs of leukemia patients and their unrelated donors for hematopoietic stem cell transplantation (HSCT). Donors with more than 12 KIR genes showed significantly decreased frequencies of severe acute GVHD compared with donors with less than 11 KIR genes (P < 0.05). The distribution of KIR genotypes was not different between severe and mild acute GVHD in patients and donors, respectively. These results suggest that the number of KIR genes in donors could influence the occurrence of acute GVHD after unrelated HSCT.

Positive regulation of ASK1-mediated c-Jun NH2-terminal kinase signaling pathway by the WD-repeat protein Gemin5

Gemin5 is a 170-kDa WD-repeat-containing protein that was initially identified as a component of the survival of motor neurons (SMN) complex. We now show that Gemin5 facilitates the activation of apoptosis signal-regulating kinase 1 (ASK1) and downstream signaling. Gemin5 physically interacted with ASK1 as well as with the downstream kinases SEK1 and c-Jun NH(2)-terminal kinase (JNK1), and it potentiated the H(2)O(2)-induced activation of each of these kinases in intact cells. Moreover, Gemin5 promoted the binding of ASK1 to SEK1 and to JNK1, as well as the ASK1-induced activation of JNK1. In comparison, Gemin5 did not physically associate with MKK7, MKK3, MKK6, or p38. Furthermore, depletion of endogenous Gemin5 by RNA interference (RNAi) revealed that Gemin5 contributes to the activation of ASK1 and JNK1, and to apoptosis induced by H(2)O(2) and tumor necrosis factor-alpha (TNFalpha) in HeLa cells. Together, our results suggest that Gemin5 functions as a scaffold protein for the ASK1-JNK1 signaling module and thereby potentiates ASK1-mediated signaling events.

Characteristics of CADASIL in Korea: A novel cysteine-sparing Notch3 mutation

OBJECTIVE

To elucidate the phenotype, genotype, and MRI findings of Korean patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and mutation carriers.

METHODS

The authors studied 40 members of nine unrelated Korean CADASIL families. After genetic analysis of Notch3, clinical and MRI findings were correlated in 27 mutation carriers.

RESULT

Notch3 mutation sites were C174R (one family, n = 3), R133C (one family, n = 3), R587C (one family, n = 1), R544C (two families, n = 5), and R75P (four families, n = 15). The clinical features were typical of CADASIL, but the frequency of migraine in the Korean population appears low. MRI abnormalities were found in 54% of the mutant carriers, the most common being white matter hyperintensities. The prevalence of lacunes and microbleeds increased with patient age. Anterior temporal areas were less often involved in subjects with R75P mutations than in those where mutations occurred in other sites (p = 0.02). Gradient echo imaging identified microbleedings in 33% of mutation carriers (64% of those with abnormal MRI), whereas diffusion-weighted MRI showed abnormal findings in only one patient. Neurologic disability was related to the number of lacunar infarcts and the lesion volume of white matter hyperintensities (p < 0.001) whereas MMSE score was related to the number of lacunar infarcts (p < 0.005).

CONCLUSIONS

Although Korean cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) mutation carriers show similar clinical and MRI findings, these abnormalities appear less frequently than in other populations. Relatively frequent microbleedings on gradient echo imaging suggest that treatment should be individualized according to MRI findings. The novel mutation of R75P, not involving a cysteine residue, is related to less frequent involvement of the anterior temporal area, thus broadening the spectrum of CADASIL.

Fluorescence in situ hybridization analysis of nitrifiers in piggery wastewater treatment reactors

Fluorescence in situ hybridization (FISH) was performed to analyze the nitrifying microbial communities in an activated sludge reactor (ASR) and a fixed biofilm reactor (FBR) for piggery wastewater treatment. Heterotrophic oxidation and nitrification were occurring simultaneously in the ASR and the COD and nitrification efficiencies depend on the loads. In the FBR nitrification efficiency also depends on ammonium load to the reactor and nitrite was accumulated when free ammonia concentration was higher than 0.2 mg NH3-N/L. FISH analysis showed that ammonia-oxidizing bacteria (NSO1225) and denitrifying bacteria (RRP1088) were less abundant than other bacteria (EUB338) in ASR. Further analysis on nitrifying bacteria in the FBR showed that Nitrosomonas species (NSM156) and Nitrospira species (NSR1156) were the dominant ammonia-oxidizing and nitrite-oxidizing bacteria, respectively, in the piggery wastewater nitrification system.

Nonviral vector for efficient gene transfer to human ovarian adenocarcinoma cells

OBJECTIVE

Various strategies have been attempted to design efficient protocols for ovarian cancer gene therapy but there has been little progress in their clinical application. In this study, we formulated and evaluated a new cationic liposome prepared with dioleoyltrimethylaminopropane (DOTAP), 1,2-dioleoyl-3-phosphophatidylethanolamine (DOPE), and cholesterol (Chol) (DDC) for plasmid DNA transfer into ovarian cancer cells.

METHOD

The DDC liposome was prepared by mixing the DOTAP:DOPE:Cholin a 1:0.7:0.3 molar ratio using the extrusion method. Plasmid DNA (pEGFP-C1) and DDC were complexed at various weight ratios to find the optimum condition and the percentage of transfected cells was determined by selecting a green fluorescence protein (GFP) expressing cells in flow cytometry. The transfection efficiency of the DDC liposome was compared with 3[N-(N,N-dimethylaminoethylene) carbamoyl] cholesterol (DC-Chol)/DOPE liposome and commercially available lifopectin.

RESULTS

The optimal transfection of plasmid DNA was achieved at a 1:4 (w/w) ratio of DDC to DNA. The DDC/DNA complex exhibited higher transfection efficiency in human ovarian cancer cells (OVCAR-3 and SK-OV-3 cells) compared to that in other types of cell lines (NCI-NIH:522 and HepG2 cells). Flow cytometric analysis revealed that the DDC/DNA complex exhibited an over fourfold increase in GFP expression levels compared with DC-Chol/DOPE or lipofectin in OVCAR-3 cells. This result was further confirmed by confocal microscopy and RT-PCR analysis.

CONCLUSION

These results suggest that our newly formulated cationic liposome (DDC) appears to be a promising nonviral vector for treating ovarian adenocarcinoma because of its selective high gene transfer ability in ovarian cancer cells.

A divalent recombinant immunotoxin formed by a disulfide bond between the extension peptide chains

Recombinant immunotoxin for the treatment of cancer was made by connecting toxins to 'carcinoma-specific' antibodies that selectively bind to cancer cells, then kills them without harming the normal cells. The divalent recombinant immunotoxin, [B3(Fab)-ext-PE38]2, is a derivative of B3(Fab)-PE38. B3(Fab)-PE38 was made by fusing the Fab domain of the monoclonal antibody (MAb) B3 to PE38, a truncated mutant form of Pseudomonas exotoxin (PE). In this study, B3(Fab)-ext-PE38 was constructed, which has the hinge region of the B3(Fab)-PE38 extended with the peptide extension, G4C(G4S)2, and connected to the C3 connector. The Cys residue of the extension peptide chain makes the disulfide bond between the two Fab domains. The extension sequence (ext) makes the dimerization of B3(Fab)-ext-PE38 easier to form the divalent immunotoxin, because it decreases the steric hindrance between the two PE38s. The constructed genes were expressed in E. coli as inclusion bodies. Polypeptides that were obtained from the inclusion body were refolded, and the active forms were purified. The ID50 values of the divalent molecule, [B3(Fab)-ext-PE38]2, were about 4 ng/ml on A431 cell lines, about 1 ng/ml on CRL1739 cell lines, and 5 ng/ml on MCF-7 cell lines. The [B3(Fab)-ext-PE38]2 showed about a 12-fold higher cytotoxicity on CRL1739 cell lines than B3(scFv)-PE40 did.

Low-density cDNA array-coupled to PCR differential display identifies new estrogen-responsive genes during the postnatal differentiation of the rat hypothalamus

To identify estrogen (E)-responsive genes that may play important roles in the sexual differentiation and maturation of the neuroendocrine hypothalamus, we used mRNA differential display PCR to analyze hypothalamic RNA derived from estrogen-sterilized rats (ESRs). Neonatal rats were s.c.-injected with 100 microg of 17 beta-estradiol-benzoate (EB) for 5 days. Approximately 300 out of more than 2000 RNAs examined displayed a differential expression pattern between hypothalami of the ESR females compared to their 60-day-old controls. EB-dependent expression of these genes was further analyzed by low-density cDNA array using cDNA probe sets reverse-transcribed from the same groups; 98 genes were confirmed to be differentially expressed. We selected 41 clones that showed higher density differences between the two probe sets than mean density difference in control cyclophilin cDNA blots in the cDNA array. After being cloned into pGEM-T vectors, their sequences were analyzed. Homology searches identified four genes as a protein kinase C (PKC)-binding protein, NELL2 (clone 6-1), a thyroid nuclear factor, TTF-1 (9-1), Munc18-1 (17-6), and leuserpin-2 (18-5). The other 22 genes were similar to reported genes or cDNAs such as mouse kinesin-associated protein 3 (KAP3, 8b), mouse IgE binding lectin (15-1), normalized rat brain cDNA (5-1), rat cDNA (8-1) and rat embryonic cDNA (17-1). Fifteen clones such as clone 7-3 showed no match in the GenBank Database. Further characterization of eight clones (17-1, 7-3, 8-1, 5-1, NELL2, KAP3 homolog, IgE binding lectin homolog, and TTF-1) showed that their expression in the adult female rat hypothalamus is sensitive to neonatal treatment with EB. They showed brain-specific expression and moreover, showed an increase in their mRNA level before the initiation of puberty. Some of them showed gender differences in their different postnatal expression pattern. We speculate that further study will demonstrate that many of the E-regulated genes identified in the present study play important roles in the regulation of the sexual differentiation and E-dependent maturation of the hypothalamus.

Implication of co-measured platelet factor 4 in the reliability of the results of the plasma transforming growth factor-beta 1 measurement

We examined the possible alteration of circulating transforming growth factor-beta1 (TGF-beta1) concentrations in a time-dependent fashion in human plasma. Plasma TGF-beta1 was measured three times at 2 week-intervals from each of 12 healthy participants. Platelet factor 4 (PF4) was measured in parallel with TGF-beta1 to estimate the degree of platelet degranulation. TGF-beta1 levels of the second and third plasma samples, in which PF4s were measured as < approximately 1000 IU/ml, were relatively low and fell in a narrow range. However, TGF-beta1 levels of the first samples, in most of which PF4s were > approximately 1000 IU/ml, appeared much higher and more variable than those of the second or third samples. These results indicate that the platelet degranulation accounted for the higher TGF-beta1 levels in the first samples, and thus did not support our initial assumption. We, nevertheless, could propose a useful guidance in the assessment of TGF-beta1 levels in plasma. When the PF4 level is measured as < approximately 1000 IU/ml under our assay conditions, the TGF-beta1 level in a given plasma sample might be accepted as a reliable value considering the effect of platelet degranulation on TGF-beta1 level.

Apoptosis signal-regulating kinase 1 controls the proapoptotic function of death-associated protein (Daxx) in the cytoplasm

Although Daxx (death-associated protein) was first reported to mediate the apoptotic signal from Fas to JNK in the cytoplasm, other data suggested that Daxx is mainly located in the nucleus as a transcriptional regulator. Here, we demonstrated that cellular localization of Daxx could be determined by the relative concentration of a proapoptotic kinase, apoptosis signal-regulating kinase 1 (ASK1) by using immunofluorescence and transcriptional reporter assay. ASK1 sequestered Daxx in the cytoplasm and inhibited the repressive activity of Daxx in transcription. In addition, Daxx was bound to the activated Fas only in the presence of ASK1, accelerating the Fas-mediated apoptosis. These results suggest that Daxx requires ASK1 for its cytoplasmic localization and Fas-mediated signaling. Taken together, we could conclude that ASK1 controls the dual function of Daxx as a transcriptional repressor in the nucleus and as a proapoptotic signal mediator in the cytoplasm.

Thyroxine treatment induces upregulation of renin-angiotensin-aldosterone system due to decreasing effective plasma volume in patients with primary myxoedema

BACKGROUND

In experimental animals and humans, hypothyroidism is associated with fluid retention and generalized oedema, increased antidiuretic hormone (ADH), decreased atrial natriuretic hormone (ANH), and decreased renin-angiotensin-aldosterone system (RAAS), which subsequently can be corrected by thyroid hormone replacement. The purpose of this study was to determine the effect of thyroxine therapy on RAAS and neurohormones affecting water and electrolyte metabolism and the reason for these changes in patients with primary myxoedema.

METHODS

We measured changes in the plasma renin activity (PRA), serum aldosterone (Aldo), ADH, ANH levels, serum and 24 h urinary electrolytes and osmolalities, and cardiac function in 22 female patients with primary myxoedema before and after correction of hypothyroidism. We also evaluated age-, sex-, and BMI-matched 15 healthy control subjects (Cont).

RESULTS

It took an average of 4.3 months (range, 3-9 months) to normalize thyroid function. The mean reductions of body weight and estimated plasma volume were 1.8+/-1.0 kg (P=0.002) and 8.5% (P<0.001), respectively. In addition, serum Na+ and osmolality and the haematocrit were significantly elevated after correction of hypothyroidism (P<0.01 and P<0.001, respectively). Increased F(E)Na and C(OSM) (P<0.05) levels in patients with hypothyroidism (Ho) compared with those in Cont did not change after thyroxine therapy (Eu). However, C(H(2)O), U(E)K, F(E)K, and TTKG levels as well as creatinine clearance (Ccr) were markedly increased in Eu compared with Ho and Cont (P<0.01, respectively). Increased plasma ADH concentration and decreased plasma ANH concentration were normalized compared to Cont after thyroxine therapy (P<0.001 and P<0.01, respectively). Low PRA and serum Aldo concentration in Ho were significantly increased in Eu (P<0.001 and P<0.01, respectively). In addition, increased left ventricular mass index and decreased cardiac output in Ho were normalized compared to Cont after thyroxine therapy (P<0.01, respectively)

CONCLUSIONS

These findings suggest that the exaggerated upregulation of RAAS after correction of hypothyroidism in patients with primary myxoedema is associated with an increase in Ccr and a decrease in plasma volume resulting from water diuresis, natriuresis, osmotic diuresis and inappropriate changes in plasma ADH and ANH levels. The improved renal function coincided with an amelioration of cardiac function. These changes seem to be an adaptive response for preventing excessive plasma volume and weight loss after thyroxine therapy.

Kaposi's sarcoma-associated herpesvirus open reading frame 50 represses p53-induced transcriptional activity and apoptosis

Kaposi's sarcoma-associated herpesvirus (KSHV) open reading frame 50 (ORF50) encodes a viral transcriptional activator which stimulates the transcription of viral early and late genes of KSHV. Here we show that ORF50 represses transcriptional activity of p53 and p53-induced apoptosis through interaction with CREB binding protein (CBP). This inhibitory effect of ORF50 on the transcriptional activity of p53 was relieved by the addition of CBP. ORF50 mutants, which are defective in interaction with CBP, lost the inhibitory effects on p53. Our data provide a framework for delineating the regulatory mechanisms used by KSHV to modulate cellular transcription and the cell cycle.

Role of Receptor-interacting Protein in Tumor Necrosis Factor-α-dependent MEKK1 Activation

Receptor-interacting protein (RIP), a death domain serine/threonine kinase, has been shown to play a critical role in tumor necrosis factor-alpha (TNF-alpha)-induced activation of the nuclear factor-kappaB signaling pathway. We demonstrate here that ectopically expressed RIP induces I-kappaB kinase-beta (IKKbeta) activation in intact cells and that RIP-induced IKKbeta activation can be blocked by a kinase-inactive form of MEKK1, MEKK1(K1253M). Interestingly, RIP physically associated with MEKK1 both in vitro and in vivo. RIP phosphorylated MEKK1 at Ser-957 and Ser-994. Our data also indicate that RIP induced the stimulation of MEKK1 but not MEKK1(S957A/S994A) in transfected cells. Furthermore, overexpressed MEKK1(S957A/S994A) inhibited the RIP-induced activation of both IKKbeta and nuclear factor-kappaB. We also demonstrated that the TNF-alpha-induced MEKK1 activation was defective in RIP-deficient Jurkat cells. Taken together, our results suggest that RIP phosphorylates and activates MEKK1 and that RIP is involved in TNF-alpha-induced MEKK1 activation.

Zn(2+) induces stimulation of the c-Jun N-terminal kinase signaling pathway through phosphoinositide 3-Kinase

Zn(2+), one of the most abundant trace metal ions in mammalian cells, modulates the functions of many regulatory proteins associated with a variety of cellular activities. In the central nervous system, Zn(2+) is highly localized in the cerebral cortex and hippocampus. It has been proposed to play a role in normal brain function as well as in the pathophysiology of certain neurodegenerative disorders. We here report that Zn(2+) induced stimulation of the c-Jun N-terminal kinase (JNK) pathway in mouse primary cortical cells and in various cell lines. Exposure of cells to Zn(2+) resulted in the stimulation of JNK and its upstream kinases including stress-activated protein kinase kinase and mitogen-activated protein kinase kinase kinase. Zn(2+) also induced stimulation of phosphoinositide 3-kinase (PI3K) The Zn(2+)-induced JNK stimulation was blocked by LY294002, a PI3K inhibitor, or by a dominant-negative mutant of PI3Kgamma. Furthermore, overexpression of Rac1N17, a dominant negative mutant of Rac1, suppressed the Zn(2+)- and PI3Kgamma-induced JNK stimulation. The stimulatory effect of Zn(2+) on both PI3K and JNK was repressed by the free-radical scavenging agent N-acetylcysteine. Taken together, our data suggest that Zn(2+) induces stimulation of the JNK signaling pathway through PI3K-Rac1 signals and that the free-radical generation may be an important step in the Zn(2+) induction of the JNK stimulation.

Glutathione S-transferase mu modulates the stress-activated signals by suppressing apoptosis signal-regulating kinase 1

Apoptosis signal-regulating kinase 1 (ASK1) is a mitogen-activated protein kinase kinase kinase that can activate the c-Jun N-terminal kinase and the p38 signaling pathways. It plays a critical role in cytokine- and stress-induced apoptosis. To further characterize the mechanism of the regulation of the ASK1 signal, we searched for ASK1-interacting proteins employing the yeast two-hybrid method. The yeast two-hybrid assay indicated that mouse glutathione S-transferase Mu 1-1 (mGSTM1-1), an enzyme involved in the metabolism of drugs and xenobiotics, interacted with ASK1. We subsequently confirmed that mGSTM1-1 physically associated with ASK1 both in vivo and in vitro. The in vitro binding assay indicated that the C-terminal portion of mGSTM1-1 and the N-terminal region of ASK1 were crucial for binding one another. Furthermore, mGSTM1-1 suppressed stress-stimulated ASK1 activity in cultured cells. mGSTM1-1 also blocked ASK1 oligomerization. The ASK1 inhibition by mGSTM1-1 occurred independently of the glutathione-conjugating activity of mGSTM1-1. Moreover, mGSTM1-1 repressed ASK1-dependent apoptotic cell death. Taken together, our findings suggest that mGSTM1-1 functions as an endogenous inhibitor of ASK1. This highlights a novel function for mGSTM1-1 insofar as mGSTM1-1 may modulate stress-mediated signals by repressing ASK1, and this activity occurs independently of its well-known catalytic activity in intracellular glutathione metabolism.

Role of phospholipase C-gamma1 in insulin-like growth factor I-induced muscle differentiation of H9c2 cardiac myoblasts

Insulin-like growth factor-I (IGF-I) regulates muscle differentiation through phosphatidylinositol 3-kinase (PI 3-kinase). Also it was recently reported that PI 3-kinase is involved in the activation of phospholipase C-gamma1 (PLC-gamma1). We investigated whether PLC-gamma1 therefore plays a role in IGF-I-induced muscle differentiation using H9c2 rat cardiac myoblasts as a model. IGF-I was able to activate PLC-gamma1 via both PI 3-kinase-dependent and tyrosine phosphorylation-dependent mechanisms in this model. However, PI 3-kinase appeared to play a more important role than tyrosine phosphorylation in IGF-I activation of PLC-gamma1. In addition, PLC-gamma1 activation was independent of Akt/protein kinase B (Akt/PKB). Importantly, PLC-gamma1 was involved in IGF-I-induced muscle differentiation in parallel with Akt/PKB. Taken together, these results suggest that IGF-I regulation of muscle differentiation is dependent on the activation of PLC-gamma1 and Akt/PKB, both of which are downstream mediators of PI 3-kinase.

Glutamine-dependent antiapoptotic interaction of human glutaminyl-tRNA synthetase with apoptosis signal-regulating kinase 1

Glutamine has been known to be an apoptosis suppressor, since it blocks apoptosis induced by heat shock, irradiation, and c-Myc overexpression. Here, we demonstrated that HeLa cells were susceptible to Fas-mediated apoptosis under the condition of glutamine deprivation. Fas ligation activated apoptosis signal-regulating kinase 1 (ASK1) and c-Jun N-terminal kinase (JNK; also known as stress-activated protein kinase (SAPK)) in Gln-deprived cells but not in normal cells, suggesting that Gln might be involved in the activity control of ASK1 and JNK/SAPK. As one of the possible mechanisms for the suppressive effect of Gln on ASK1, we investigated the molecular interaction between human glutaminyl-tRNA synthetase (QRS) and ASK1 and found the Gln-dependent association of the two molecules. While their association was enhanced by the elevation of Gln concentration, they were dissociated by Fas ligation within 5 min. The association involved the catalytic domains of the two enzymes. The ASK1 activity was inhibited by the interaction with QRS as determined by in vitro kinase and transcription assays. Finally, we have shown that QRS inhibited the cell death induced by ASK1, and this antiapoptotic function of QRS was weakened by the deprivation of Gln. Thus, the antiapoptotic interaction of QRS with ASK1 is controlled positively by the cellular concentration of Gln and negatively by Fas ligation. The results of this work provide one possible explanation for the working mechanism of the antiapoptotic activity of Gln and suggest a novel function of mammalian ARSs.

Nitric oxide negatively regulates c-Jun N-terminal kinase/stress-activated protein kinase by means of S-nitrosylation

NO, produced from l-arginine in a reaction catalyzed by NO synthase, is an endogenous free radical with multiple functions in mammalian cells. Here, we demonstrate that endogenously produced NO can suppress c-Jun N-terminal kinase (JNK) activation in intact cells. Treatment of BV-2 murine microglial cells with IFN-gamma induced endogenous NO production, concomitantly suppressing JNK1 activation. Similarly, IFN-gamma induced suppression of JNK1 activation in RAW264.7 murine macrophage cells and rat alveolar macrophages. The IFN-gamma-induced suppression of JNK1 activation in BV-2, RAW264.7, or rat alveolar macrophage cells was completely prevented by N(G)-nitro-l-arginine, a NO synthase inhibitor. Interestingly, the IFN-gamma-induced suppression of JNK1 activation was not affected by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of guanylyl cyclase. 8-Bromo-cGMP, a membrane-permeant analogue of cGMP, did not change JNK1 activation in intact cells either. In contrast, S-nitro-N-acetyl-dl-penicillamine (SNAP), a NO donor, inhibited JNK1 activity in vitro. Furthermore, a thiol reducing agent, DTT, reversed not only the in vitro inhibition of JNK1 activity by SNAP but also the in vivo suppression of JNK1 activity by IFN-gamma. Substitution of serine for cysteine-116 in JNK1 abolished the inhibitory effect of IFN-gamma or SNAP on JNK1 activity in vivo or in vitro, respectively. Moreover, IFN-gamma enhanced endogenous S-nitrosylation of JNK1 in RAW264.7 cells. Collectively, our data suggest that endogenous NO mediates the IFN-gamma-induced suppression of JNK1 activation in macrophage cells by means of a thiol-redox mechanism.

Structural and functional dissection of human cytomegalovirus US3 in binding major histocompatibility complex class I molecules

The human cytomegalovirus US3, an endoplasmic reticulum (ER)-resident transmembrane glycoprotein, forms a complex with major histocompatibility complex (MHC) class I molecules and retains them in the ER, thereby preventing cytolysis by cytotoxic T lymphocytes. To identify which parts of US3 confine the protein to the ER and which parts are responsible for the association with MHC class I molecules, we constructed truncated mutant and chimeric forms in which US3 domains were exchanged with corresponding domains of CD4 and analyzed them for their intracellular localization and the ability to associate with MHC class I molecules. All of the truncated mutant and chimeric proteins containing the luminal domain of US3 were retained in the ER, while replacement of the US3 luminal domain with that of CD4 led to cell surface expression of the chimera. Thus, the luminal domain of US3 was sufficient for ER retention. Immunolocalization of the US3 glycoprotein after nocodazole treatment and the observation that the carbohydrate moiety of the US3 glycoprotein was not modified by Golgi enzymes indicated that the ER localization of US3 involved true retention, without recycling through the Golgi. Unlike the ER retention signal, the ability to associate with MHC class I molecules required the transmembrane domain in addition to the luminal domain of US3. Direct interaction between US3 and MHC class I molecules could be demonstrated after in vitro translation by coimmunoprecipitation. Together, the present data indicate that the properties that allow US3 to be localized in the ER and bind MHC class I molecules are located in different parts of the molecule.

High glucose-induced intercellular adhesion molecule-1 (ICAM-1) expression through an osmotic effect in rat mesangial cells is PKC-NF-kappa B-dependent

AIMS/HYPOTHESIS

Infiltration of mononuclear cells and glomerular enlargement accompanied by glomerular cell proliferation are very early characteristics of the pathophysiology of diabetes. To clarify the mechanism of early diabetic nephropathy, we measured [3H]-thymidine incorporation and cell numbers to show the influence of a high ambient glucose concentration and the osmotic effect on rat mesangial cell proliferation. We also measured the effect of high glucose on the expression of intercellular adhesion molecule-1 and vascular adhesion molecule-1 by flow cytometry and semiquantitative RT-PCR in mesangial cells and the adhesion of leukocytes to mesangial cells.

METHODS/RESULTS

Cells exposed to high D-glucose (30 mmol/l) caused an increase in [3H]-thymidine incorporation and cell numbers at 24 and 48 h and normalized at 72 h (p < 0.05), whereas these changes were not found in high mannitol (30 mmol/l), IL-1 beta, or TNF alpha-stimulated mesangial cells. Cells exposed to high-glucose (15, 30, or 60 mmol/l) or osmotic agents (L-glucose, raffinose and mannitol) showed that intercellular adhesion molecule-1 expression began to increase after 24 h, reached its maximum at 24 and 48 h and gradually decreased afterwards. The stimulatory effects of high glucose and high mannitol on mRNA expression were observed as early as 6 h and reached its maximum at 12 h. Up-regulation of ICAM-1 protein and mRNA was also found in IL-1-beta and TNF-alpha-stimulated mesangial cells. Neither vascular adhesion molecule-1 protein nor mRNA expression was, however, affected by high glucose and high mannitol. Notably, the protein kinase C inhibitors calphostin C and staurosporine reduced high glucose- or high mannitol-induced intercellular adhesion molecule-1 mRNA expression and high glucose-induced proliferation. Furthermore, the NF-kappa B inhibitor N-tosyl-L-phenylalanine chloromethyl ketone reduced high glucose- or high mannitol-induced intercellular adhesion molecule-1 mRNA expression and high glucose-induced proliferation. Results showed that high glucose (15, 30 mmol/l) or high concentrations of osmotic agents remarkably increased the number of adherent leukocytes to mesangial cells (p < 0.01) compared with control cells (5 mmol/l D-glucose). Functional blocking of intercellular adhesion molecule-1 on mesangial cells with rat intercellular adhesion molecule-1 monoclonal antibody, calphostin C, staurosporine, or N-tosyl-L-phenylalanine chloromethyl ketone significantly inhibited high glucose- or high mannitol-induced increase in leukocyte adhesion (p << 0.05).

CONCLUSION/INTERPRETATION

These results suggest that high glucose can upregulate intercellular adhesion molecule-1 protein and mRNA expression but not vascular adhesion molecule-1 expression in mesangial cells and promote leukocyte adhesion through up-regulation of intercellular adhesion molecule-1 through osmotic effect, possibly depending on the protein kinase C nuclear factor-kappa B (PKC-NF-kappa B) pathway. High glucose itself can also promote mesangial cell proliferation through the PKC-NF-kappa B pathways. We conclude that hyperglycaemia in itself seems to be an important factor in the development of early diabetic nephropathy.