UBE4B regulates p27 expression in A549 NSCLC cells through regulating the interaction of HuR and the p27 5' UTR

Ubiquitination factor E4B (UBE4B) has a tumor-promoting effect, demonstrated by its aberrant expression in various types of cancers, and in vitro studies have shown that the retardation of cancer cell proliferation can be induced by targeting UBE4B. However, the molecular pathways through which UBE4B exerts its oncogenic activities have not yet been clearly identified and existing knowledge is limited to p53 and its subsequent downstream targets. In this study, we demonstrated that UBE4B regulates p27 expression in A549 cells via the cap-independent translation pathway following treatment with rapamycin and cycloheximide (CHX). Subsequently, we identified that UBE4B regulates p27 translation by regulating the interaction between human antigen R (HuR) and the p27 internal ribosomal entry site (IRES). First, UBE4B interacts with HuR, which inhibits p27 translation through the IRES. Secondly, the interaction between HuR and the p27 IRES was diminished by UBE4B depletion and enhanced by UBE4B overexpression. Finally, HuR depletion-induced growth retardation, accompanied by p27 accumulation, was restored by UBE4B overexpression. Collectively, these results suggest that the oncogenic properties of UBE4B in A549 cells are mediated by HuR, suggesting the potential of targeting the UBE4B-HuR-p27 axis as a therapeutic strategy for lung cancer.

TRIM22 facilitates autophagosome-lysosome fusion by mediating the association of GABARAPs and PLEKHM1

Tripartite motif (TRIM) proteins are a large family of E3 ubiquitin ligases implicated in antiviral defense systems, tumorigenesis, and protein quality control. TRIM proteins contribute to protein quality control by regulating the ubiquitin-proteasome system, endoplasmic reticulum-associated degradation, and macroautophagy/autophagy. However, the detailed mechanisms through which various TRIM proteins regulate downstream events have not yet been fully elucidated. Herein, we identified a novel function of TRIM22 in the regulation of autophagy. TRIM22 promotes autophagosome-lysosome fusion by mediating the association of GABARAP family proteins with PLEKHM1, thereby inducing the autophagic clearance of protein aggregates, independent of its E3 ubiquitin ligase activity. Furthermore, a TRIM22 variant associated with early-onset familial Alzheimer disease interferes with autophagosome-lysosome fusion and autophagic clearance. These findings suggest TRIM22 as a critical autophagic regulator that orchestrates autophagosome-lysosome fusion by scaffolding autophagy-related proteins, thus representing a potential therapeutic target in neurodegenerative diseases.Abbreviations: AD: Alzheimer disease; ADAOO: AD age of onset; AICD: APP intracellular domain; APP: amyloid beta precursor protein; BSA: bovine serum albumin; cDNAs: complementary DNAs; CQ: chloroquine; CTF: carboxyl-terminal fragment; EBSS: Earle's balanced salt solution; GABARAP: GABA type A receptor-associated protein; GST: glutathione S-transferase; HA: hemagglutinin; HOPS: homotypic fusion and protein sorting; IFN: interferon; IL1A/IL-1α: interleukin 1 alpha; KO: knockout; MTORC1: mechanistic target of rapamycin kinase complex 1; NFKBIA/IκBα: NFKB inhibitor alpha; NFE2L2/NRF2: NFE2 like bZIP transcription factor; PBS: phosphate-buffered saline; PI3K: class I phosphoinositide 3-kinase; PLA: proximity ligation assay; PLEKHM1: pleckstrin homology and RUN domain containing M1; PSEN1: presenilin 1; SEM: standard errors of the means; SNAREs: soluble N-ethylmaleimide-sensitive factor attachment protein receptors; SNCA: synuclein alpha; SNP: single nucleotide polymorphism; TBS: tris-buffered saline; TNF/TNF-α: tumor necrosis factor; TRIM: tripartite motif; ULK1: unc-51 like autophagy activating kinase 1; WT: wild-type.

Skeletal Muscle-Specific Bis Depletion Leads to Muscle Dysfunction and Early Death Accompanied by Impairment in Protein Quality Control

Bcl-2-interacting cell death suppressor (BIS), also called BAG3, plays a role in physiological functions such as anti-apoptosis, cell proliferation, autophagy, and senescence. Whole-body Bis-knockout (KO) mice exhibit early lethality accompanied by abnormalities in cardiac and skeletal muscles, suggesting the critical role of BIS in these muscles. In this study, we generated skeletal muscle-specific Bis-knockout (Bis-SMKO) mice for the first time. Bis-SMKO mice exhibit growth retardation, kyphosis, a lack of peripheral fat, and respiratory failure, ultimately leading to early death. Regenerating fibers and increased intensity in cleaved PARP1 immunostaining were observed in the diaphragm of Bis-SMKO mice, indicating considerable muscle degeneration. Through electron microscopy analysis, we observed myofibrillar disruption, degenerated mitochondria, and autophagic vacuoles in the Bis-SMKO diaphragm. Specifically, autophagy was impaired, and heat shock proteins (HSPs), such as HSPB5 and HSP70, and z-disk proteins, including filamin C and desmin, accumulated in Bis-SMKO skeletal muscles. We also found metabolic impairments, including decreased ATP levels and lactate dehydrogenase (LDH) and creatine kinase (CK) activities in the diaphragm of Bis-SMKO mice. Our findings highlight that BIS is critical for protein homeostasis and energy metabolism in skeletal muscles, suggesting that Bis-SMKO mice could be used as a therapeutic strategy for myopathies and to elucidate the molecular function of BIS in skeletal muscle physiology.

SF3B4 Depletion Retards the Growth of A549 Non-Small Cell Lung Cancer Cells via UBE4B-Mediated Regulation of p53/p21 and p27 Expression

Splicing factor B subunit 4 (SF3B4), a component of the U2-pre-mRNA spliceosomal complex, contributes to tumorigenesis in several types of tumors. However, the oncogenic potential of SF3B4 in lung cancer has not yet been determined. The in vivo expression profiles of SF3B4 in non-small cell lung cancer (NSCLC) from publicly available data revealed a significant increase in SF3B4 expression in tumor tissues compared to that in normal tissues. The impact of SF3B4 deletion on the growth of NSCLC cells was determined using a siRNA strategy in A549 lung adenocarcinoma cells. SF3B4 silencing resulted in marked retardation of the A549 cell proliferation, accompanied by the accumulation of cells at the G0/G1 phase and increased expression of p27, p21, and p53. Double knockdown of SF3B4 and p53 resulted in the restoration of p21 expression and partial recovery of cell proliferation, indicating that the p53/p21 axis is involved, at least in part, in the SF3B4-mediated regulation of A549 cell proliferation. We also provided ubiquitination factor E4B (UBE4B) is essential for p53 accumulation after SF3B4 depletion based on followings. First, co-immunoprecipitation showed that SF3B4 interacts with UBE4B. Furthermore, UBE4B levels were decreased by SF3B4 depletion. UBE4B depletion, in turn, reproduced the outcome of SF3B4 depletion, including reduction of polyubiquitinated p53 levels, subsequent induction of p53/p21 and p27, and proliferation retardation. Collectively, our findings indicate the important role of SF3B4 in the regulation of A549 cell proliferation through the UBE4B/p53/p21 axis and p27, implicating the therapeutic strategies for NSCLC targeting SF3B4 and UBE4B.

Hepatocyte-specific deletion of Bis causes senescence in the liver without deteriorating hepatic function

Bcl-2-interacting cell death suppressor (BIS), also called as BAG3, regulates numerous physiological processes, such as apoptosis, protein quality control, and senescence. Whole-body Bis-knockout (KO) mice exhibit early lethality following cardiac and skeletal muscle dysfunction. The first attempt to generate organ-specific knockout mice resulted in constitutive or inducible heart-specific Bis-knockout mice, which exhibited cardiac dilation and underwent premature death. Here, we generated hepatocyte-specific Bis-knockout (Bis-HKO) mice and found no abnormalities in metabolic function and survival. However, depletion of HSPB8 and accumulation of p62 indicated impaired autophagy in Bis-HKO livers. Interestingly, the number of peroxisomes wrapped by phagophore membranes increased as evidenced by transmission electron microscopy analysis, indicating defects in the progression of pexophagy. In addition, increased dihydroethidine intensities and histone H3 K9me3-positive nuclei indicated increased oxidative stress and senescence induction in Bis-HKO livers. Mechanistically, p27 was upregulated in Bis-HKO livers. In SNU368 hepatocellular carcinoma cells, BIS depletion led to p27 upregulation, and increase in histone H3 K9me3 levels and senescence-associated β-galactosidase staining; therefore, reproducing the in vivo senescence phenotype. Despite the observation of no metabolic abnormalities, BIS depletion led to defective autophagy, increased oxidative stress, and senescence in Bis-HKO livers. Collectively, our results suggest a role for BIS in maintaining liver regeneration potential under pathological conditions.

Neuropsychological adverse drug reactions of Remdesivir: analysis using VigiBase, the WHO global database of individual case safety reports

OBJECTIVE

Although remdesivir (GS-5734) has recently demonstrated clinical benefits against the pandemic outbreak of coronavirus disease 2019 (COVID-19), neuropsychological adverse reactions (ADRs) remain to be examined in real-world settings. Therefore, we aimed to identify and characterize the neuropsychological ADRs associated with remdesivir use.

MATERIALS AND METHODS

We obtained data for this international pharmacovigilance cohort study from individual case safety reports (ICSRs) in a World Health Organization database (VigiBase) from the first report on remdesivir on February 17, 2020, until August 30, 2020 (n=1,403,532). ADRs reported to be relevant to remdesivir were compared with the full database by using a Bayesian neural network method to calculate the information component (IC).

RESULTS

A total of 2,107 reported cases of neuropsychological ADRs suspected to be associated with remdesivir were identified from among all ICSRs in the database during the observation period. Although 108 neuropsychological ADRs (64 neurologic events and 44 psychologic events) were reported in association with the medication, no statistically significant pharmacovigilance signal could be detected; the IC025 value was negative for all of the neuropsychological dysfunctions (anxiety [n=13, 0.62%], seizures [n=12, 0.57%], lethargy [n=6, 0.28%], agitation [n=5, 0.25%], cerebral infarction [n=3, 0.14%], ischemic stroke [n=3, 0.14%], and hemiparesis [n=3, 0.14%]).

CONCLUSIONS

Our study demonstrates that remdesivir, a novel drug applied to the treatment of COVID-19, does not have a significant association with adverse neurologic or psychiatric reactions in the real-world setting.

Depletion of ST6GALNACIII retards A549 non-small cell lung cancer cell proliferation by downregulating transferrin receptor protein 1 expression

Alterations in sialylation of terminal residues of glycoproteins have been implicated in forming tumor-associated glycans. ST6GALNAC transfers sialyl moiety to N-acetylgalactosamine residue via α2,6 linkage. Although the oncogenic characteristics of ST6GALNACI or II have been demonstrated in various cancer cells, the impact of ST6GALNACIII on tumor progression remains undefined. In this study, we evaluated the effect of ST6GALNACIII knockdown on the growth of A549 non-small cell lung cancer cells. ST6GALNACIII depletion resulted in significant retardation in growth of A549 cells under various culture conditions, including collagen-supported 3D culture and anchorage-independent soft agar culture conditions. Liquid chromatography with tandem mass spectrometry revealed that two glycopeptides of transferrin receptor protein 1 (TFR1) containing N-acetylhexosamine-sialic acid were not detected in ST6GALNACIII-depleted A549 cells compared with control cells. Subsequent lectin binding assay, western blotting, and real-time RT-PCR indicated that TFR1 sialylation was not significantly changed, but TFR1 protein and mRNA expressions were decreased after ST6GALNACIII knockdown. However, cell growth retardation by ST6GALNACIII knockdown was partially rescued by TFR1 overexpression. Additionally, TFR1 mRNA degradation was accelerated following ST6GALNACIII knockdown with concomitant reduction in mRNA levels of iron regulatory protein 1 and 2, the upstream regulators of TFR1 mRNA stability. Therefore, our results indicated an important role of ST6GALNACIII in promoting A549 cell growth through quantitative regulation of TFR1 expression and provided therapeutic implications for ST6GALNACIII targeting in tumor growth suppression in vivo.

Lactobacillus intestinalis YT2 restores the gut microbiota and improves menopausal symptoms in ovariectomized rats

There are many studies focusing on the alleviation of menopausal symptoms; however, little is known about the role of gut microorganisms in menopausal symptoms. Ovariectomized (OVX) rats were administered a novel strain (YT2) of Lactobacillus intestinalis (a species with significantly reduced abundance in OVX rats) and the potential probiotic effect on the improvement of menopausal symptoms was evaluated. Of note, the gut microbial composition completely shifted after ovariectomy in rats. Treatment with L. intestinalis YT2 significantly alleviated menopausal symptoms, such as increased fat mass, decreased bone mineral density, increased pain sensitivity, depression-like behaviour, and cognitive impairment. Additionally, the administration of L. intestinalis YT2 restored the intestinal microbial composition, including an increased Firmicutes/Bacteroides ratio. L. intestinalis YT2 also promoted gut barrier integrity by increasing the mRNA levels of tight junction-related markers. In conclusion, L. intestinalis YT2 treatment alleviated menopausal symptoms via the modulation of the gut microbiota. Importantly, these results suggest that L. intestinalis YT2 should be considered as a therapeutic probiotic agent for menopausal women.

KRIBB11 Induces Apoptosis in A172 Glioblastoma Cells via MULE-Dependent Degradation of MCL-1

KRIBB11, an HSF1 inhibitor, was shown to sensitize various types of cancer cells to treatment with several anticancer drugs. However, the exclusive effects of KRIBB11 in preventing the growth of glioblastoma cells and the related mechanisms have not been elucidated yet. Herein, we aimed to examine the potential of KRIBB11 as an anticancer agent for glioblastoma. Using MTT and colony formation assays and Western blotting for c-PARP, we demonstrated that KRIBB11 substantially inhibits the growth of A172 glioma cells by inducing apoptosis. At the molecular level, KRIBB11 decreased anti-apoptotic protein MCL-1 levels, which was attributable to the increase in MULE ubiquitin ligase levels. However, the constitutive activity of HSF1 in A172 cells was not influenced by the exclusive treatment with KRIBB11. Additionally, based on cycloheximide chase assay, we found that KRIBB11 markedly retarded the degradation of MULE. In conclusion, stabilization of MULE upon KRIBB11 treatment is apparently an essential step for degradation of MCL-1 and the subsequent induction of apoptosis in A172 cells. Our results have expanded the knowledge on molecular pathways controlled by KRIBB11 and could be potentially effective for developing an inhibitory therapeutic strategy for glioblastoma.

Tipping the immunostimulatory and inhibitory DAMP balance to harness immunogenic cell death

Induction of tumor cell death is the therapeutic goal for most anticancer drugs. Yet, a mode of drug-induced cell death, known as immunogenic cell death (ICD), can propagate antitumoral immunity to augment therapeutic efficacy. Currently, the molecular hallmark of ICD features the release of damage-associated molecular patterns (DAMPs) by dying cancer cells. Here, we show that gemcitabine, a standard chemotherapy for various solid tumors, triggers hallmark immunostimualtory DAMP release (e.g., calreticulin, HSP70, and HMGB1); however, is unable to induce ICD. Mechanistic studies reveal gemcitabine concurrently triggers prostaglandin E2 release as an inhibitory DAMP to counterpoise the adjuvanticity of immunostimulatory DAMPs. Pharmacological blockade of prostaglandin E2 biosythesis favors CD103+ dendritic cell activation that primes a Tc1-polarized CD8+ T cell response to bolster tumor rejection. Herein, we postulate that an intricate balance between immunostimulatory and inhibitory DAMPs could determine the outcome of drug-induced ICD and pose COX-2/prostaglandin E2 blockade as a strategy to harness ICD.

Hereditary spastic paraplegia SPG8 mutations impair CAV1-dependent, integrin-mediated cell adhesion

Mutations in WASHC5 (also known as KIAA0196) cause autosomal dominant hereditary spastic paraplegia (HSP) type SPG8. WASHC5, commonly called strumpellin, is a core component of the Wiskott-Aldrich syndrome protein and SCAR homolog (WASH) complex that activates actin nucleation at endosomes. Although various other cellular roles for strumpellin have also been described, none account for how SPG8-associated mutations lead to HSP. Here, we identified protein interactors of the WASH complex by immunoprecipitation and mass spectrometry and assessed the functions of strumpellin in cultured cells using both overexpression and RNA interference along with cell-spreading assays to investigate cell adhesion. We uncovered a decrease in CAV1 protein abundance as well as endosomal fission defects resulting from pathogenic SPG8 mutations. CAV1, a key component of caveolae, interacted with strumpellin in cells, and strumpellin inhibited the lysosomal degradation of CAV1. SPG8-associated missense mutations in strumpellin did not rescue endosomal tubulation defects, reduction in CAV1 protein abundance, or integrin-mediated cell adhesion in strumpellin-deficient cells. Mechanistically, we demonstrated that the WASH complex maintained CAV1 and integrin protein amounts by inhibiting their lysosomal degradation through its endosomal actin nucleation activity. In addition, the interaction of strumpellin with CAV1 stimulated integrin recycling, thereby promoting cell adhesion. These findings provide a molecular link between WASHC5 mutations and impairment of CAV1- and integrin-mediated cell adhesion, providing insights into the cellular pathogenesis of SPG8.

Functional Characterization of Resting and Adenovirus-Induced Reactive Astrocytes in Three-Dimensional Culture

Brain is a rich environment where neurons and glia interact with neighboring cells as well as extracellular matrix in three-dimensional (3D) space. Astrocytes, which are the most abundant cells in the mammalian brain, reside in 3D space and extend highly branched processes that form microdomains and contact synapses. It has been suggested that astrocytes cultured in 3D might be maintained in a less reactive state as compared to those growing in a traditional, two-dimensional (2D) monolayer culture. However, the functional characterization of the astrocytes in 3D culture has been lacking. Here we cocultured neurons and astrocytes in 3D and examined the morphological, molecular biological, and electrophysiological properties of the 3D-cultured hippocampal astrocytes. In our 3D neuron-astrocyte coculture, astrocytes showed a typical morphology of a small soma with many branches and exhibited a unique membrane property of passive conductance, more closely resembling their native in vivo counterparts. Moreover, we also induced reactive astrocytosis in culture by infecting with high-titer adenovirus to mimic pathophysiological conditions in vivo. Adenoviral infection induced morphological changes in astrocytes, increased passive conductance, and increased GABA content as well as tonic GABA release, which are characteristics of reactive gliosis. Together, our study presents a powerful in vitro model resembling both physiological and pathophysiological conditions in vivo, and thereby provides a versatile experimental tool for studying various neurological diseases that accompany reactive astrocytes.

Abstract PD2-04: FOXA1 induces a pro-metastatic secretome through ER-dependent and independent transcriptional reprogramming in endocrine-resistant breast cancer

Background: Metastasis in ER-positive (+) breast cancer (BC) occurring years to decades after initial diagnosis presents a daunting challenge for clinical care and preclinical research due to limited known key players and experimental models. FOXA1 is a pioneer factor for ER-chromatin binding and function, and is highly expressed in ER+ BC metastases, yet the underlying mechanism is unclear. Tumor-secreted proteins play a crucial role in the reciprocal interplay between cancer cells and host microenvironmental factors at both primary and secondary sites. We hypothesized that high FOXA1 provokes an ER-dependent transcriptional program that includes a unique pro-tumorigenic secretome essential for promoting ER+ BC metastasis. Methods: A lentiviral doxycycline (Dox)-inducible FOXA1 overexpression vector and a dual luciferase/GFP (LG) tracking vector were integrated to construct a stable MCF7-LG/FOXA1 cell model. Ovariectomized nude mice bearing MCF7-LG/FOXA1 xenografts in the presence of exogenous estrogen (E2) were randomized to ± Dox, each with continued E2, E2 deprivation (ED), or tamoxifen (Tam). Survival surgery removing the therapy-naïve (E2 arm) and relapsed (ED/Tam arms) tumors was performed when tumors reached ∼1000 mm3. All mice then received ED/Tam 'adjuvant' therapy, with longitudinal luminescence imaging to monitor local/distant recurrences. Mice were or will be euthanized at the ethical end-point. Integrative bioinformatics was performed using RNA-seq and FOXA1/ER ChIP-seq data from our preclinical models to identify secretome targets for functional intervention. Times to tumor regression (TTR) and progression (TTP) were defined by when the tumor reached half or twice the volume at randomization. Results: Median (m) TTR was achieved in ED (31/34 days, -/+Dox, P = 0.184) but not in Tam groups — Tam delayed tumor growth but failed to prevent progression in all mice with mTTP of 94/93 days (-/+Dox, P = 0.517). Despite no difference in mTTP at Tam-/+Dox, a quarter of +Dox tumors (3/12) had volume doubled by day 11. No metastases were observed by imaging in any of the mice before surgery ('neoadjuvant' setting). Local relapse and lymph-node/lung metastases were detected after surgery ('adjuvant' setting). At day 90 in the adjuvant Tam group with previously relapsed tumors, +Dox mice succumbed to metastasis more often than -Dox mice (7/8 vs. 3/10, P = 0.023). Compared to the adjuvant Tam+Dox mice with previous therapy-naïve tumors, the Tam+Dox with previously relapsed tumors showed higher distant metastasis rate (7/8 vs. 5/14, P = 0.026). Analysis of the ED setting is pending due to late recurrence. Data integration and functional study revealed a set of cytokines, growth factors, and extracellular matrix components (including IL-8, CTGF, and LOX), regulated by FOXA1 often in conjunction with ER, that are highly involved in FOXA1-induced metastasis. Global secretome profiling by mass spectrometry and target validation are ongoing. Conclusions: FOXA1 overexpression increases metastatic potential in ER+ BC. We established a pertinent metastatic xenograft mouse model to characterize a pro-metastatic secretome with diagnostic and therapeutic potential for treating metastatic ER+ BC.

Citation Format: Fu X, Pereira R, Zhao D, Jung SY, Jeselsohn R, Creighton CJ, Shea M, Nardone A, Angelis CD, Tsimelzon A, Wang T, Gutierrez C, Huang S, Edwards DP, Rimawi MF, Hilsenbeck SG, Brown M, Chen K, Osborne CK, Schiff R. FOXA1 induces a pro-metastatic secretome through ER-dependent and independent transcriptional reprogramming in endocrine-resistant breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD2-04.

The Ca2+-activated chloride channel anoctamin-2 mediates spike-frequency adaptation and regulates sensory transmission in thalamocortical neurons

Neuronal firing patterns, which are crucial for determining the nature of encoded information, have been widely studied; however, the molecular identity and cellular mechanisms of spike-frequency adaptation are still not fully understood. Here we show that spike-frequency adaptation in thalamocortical (TC) neurons is mediated by the Ca²⁺-activated Cl⁻ channel (CACC) anoctamin-2 (ANO2). Knockdown of ANO2 in TC neurons results in significantly reduced spike-frequency adaptation along with increased tonic spiking. Moreover, thalamus-specific knockdown of ANO2 increases visceral pain responses. These results indicate that ANO2 contributes to reductions in spike generation in highly activated TC neurons and thereby restricts persistent information transmission.

Spike-frequency adaptation in thalamocortical (TC) neurons is important for sensory transmission though the underlying mechanisms are not fully understood. Here, the authors identify a role for the calcium-activated chloride channel, ANO2, in mediating TC spiking adaptations and visceral pain response.

Impaired development and dysfunction of endothelial progenitor cells in type 2 diabetic mice

AIM

Dysfunction of circulating endothelial progenitor cells (EPCs) has been shown to affect the development of microvascular diseases in diabetes patients. The aim of this study was to elucidate the development and mechanical dysfunction of EPCs in type 2 diabetes (T2D).

METHODS

The colony-forming capacity of EPCs and differentiation potential of bone marrow (BM) c-Kit(+)/Sca-I(+) lineage-negative mononuclear cells (KSL) were examined in T2D mice, db/db mice and KKA^y mice, using EPC colony-forming assay (EPC-CFA).

RESULTS

T2D mice had fewer BM stem/progenitor cells, and proliferation of KSL was lowest in the BM of db/db mice. In T2D mice, the frequency of large colony-forming units (CFUs) derived from BM-KSL was highly reduced, indicating dysfunction of differentiation into mature EPCs. Only a small number of BM-derived progenitors [CD34(+) KSL cells], which contribute to the supply of EPCs for postnatal neovascularization, was also found. Furthermore, in terms of their plasticity to transdifferentiate into various cell types, BM-KSL exhibited a greater potential to differentiate into granulocyte macrophages (GMs) than into other cell types.

CONCLUSION

T2D affected EPC colony formation and differentiation of stem cells to mature EPCs or haematopoietic cells. These data suggest opposing regulatory mechanisms for differentiation into mature EPCs and GMs in T2D mice.

Comparison of steroid administration methods in patients with idiopathic sudden sensorineural hearing loss: a retrospective observational study

OBJECTIVES

To compare the recovery rates of patients with idiopathic sudden sensorineural hearing loss (ISSHL) treated with oral systemic steroids (PO) or intratympanic steroid injection (IT) or both.

DESIGN

A retrospective observational study.

SETTING

Tertiary referral centre.

PARTICIPANTS

Eight hundred and forty-four patients diagnosed with ISSHL within 14 days of the onset of symptoms. The patients were divided into three groups by treatment modality.

MAIN OUTCOME MEASURES

Threshold of pure-tone tests, age, accompanying symptoms and underlying diseases were compared. The level of final hearing recovery was evaluated by the application of the results of the pure-tone test that was performed at least 3 months after the completion of each treatment.

RESULTS

Final hearing recovery rate differed significantly by the type of treatment (P = 0.031). Recovery rates in the PO and combined groups were significantly higher in patients with mild (85.1% and 88.6%, respectively) than with profound (52.8% and 69.0%, respectively) hearing loss (P < 0.05). In contrast, severity and recovery rate were not significantly correlated in the IT group (P > 0.05). Combined treatment yielded significantly higher recovery rates than other treatment modalities in patients without hypertension (HTN) and diabetes mellitus (DM) (P = 0.021).

CONCLUSION

In the group treated with combined therapy, better hearing improvement was obtained than in the groups treated with systemic steroid only or with intratympanic steroid injection only without complications. These findings suggest that the combination of systemic administration and intratympanic injection may improve patient prognosis.

Identifying the potential long-term survivors among breast cancer patients with distant metastasis

BACKGROUND

We aimed to develop a prediction model to identify long-term survivors after developing distant metastasis from breast cancer.

PATIENTS AND METHODS

From the institution's database, we collected data of 547 patients who developed distant metastasis during their follow-ups. We developed a model that predicts the post-metastasis overall survival (PMOS) based on the clinicopathologic factors of the primary tumors and the characteristics of the distant metastasis. For validation, the survival data of 254 patients from four independent institutions were used.

RESULTS

The median duration of the PMOS was 31.0 months. The characteristics of the initial primary tumor, such as tumor stage, hormone receptor status, and Ki-67 expression level, and the characteristics of the distant metastasis presentation including the duration of disease-free interval, the site of metastasis, and the presence of metastasis-related symptoms were independent prognostic factors determining the PMOS. The association between tumor stage and the PMOS was only seen in tumors with early relapses. The PMOS score, which was developed based on the above six factors, successfully identified patients with superior survival after metastasis. The median PMOS for patients with a PMOS score of <2 and for patients with a PMOS score of >5 were 71.0 and 12 months, respectively. The clinical significance of the PMOS score was further validated using independent multicenter datasets.

CONCLUSIONS

We have developed a novel prediction model that can classify breast cancer patients with distant metastasis according to their survival after metastasis. Our model can be a valuable tool to identify long-term survivors who can be potential candidates for more intensive multidisciplinary approaches. Furthermore, our model can provide a more reliable survival information for both physicians and patients during their informed decision-making process.

Steroid plus antiviral treatment for Bell's palsy

OBJECTIVES

The effectiveness of antiviral agents for the treatment of Bell's palsy is uncertain. We evaluated whether a steroid with an antiviral agent (S + A group) provided better recovery outcomes than a steroid alone (S group) in patients with Bell's palsy.

SUBJECTS AND DESIGN

A total of 1342 patients diagnosed with Bell's palsy who visited the Kyung Hee Medical Center in Seoul, Korea, from 2002 to 2012 were included in this study. Patients in the S + A group were treated with prednisolone and antiviral agents (n = 569) and those in the S group with prednisolone alone (n = 773). Outcomes were measured using the House-Brackmann (HB) scale according to age, initial disease severity, electroneurography (ENoG) findings and underlying comorbidities.

RESULTS

The rate of recovery (HB grades I and II) with initially severe Bell's palsy (HB grades V and VI) was higher in the S + A than in the S group (P = 0.001). However, the rates of recovery were similar with initially moderate palsy (HB grades II-IV) (P = 0.502). In patients classified according to age and ENoG-determined severity of palsy, the overall recovery rate was higher in the S + A than in the S group, but the differences were not statistically significant (P > 0.05 for both). The recovery rate without diabetes mellitus (DM) and hypertension (HTN) was higher in the S + A group than in the S group (P = 0.031). But in the patients with HTN and DM, the difference in recovery rates between the S + A and S groups was not statistically significant (P = 0.805).

CONCLUSIONS

Treatment with a steroid plus antiviral agent resulted in significantly higher recovery rates than steroid therapy alone in patients with initially severe Bell's palsy and without either HTN or DM, and a nonsignificant trend towards higher recovery rates in all patients with Bell's palsy in this study. Antiviral agents may therefore help in the treatment of Bell's palsy.

Abstract P1-01-19: Role of axillary clearance with tumor positive sentinel node in mastectomy group: Is the results of ACOSOG Z0011 trial adaptable to mastectomy patient?

Background: Recent data from ACOSOG Z0011 trial or AMAROS trial suggest that axillary lymph node dissection(ALND) may be unnecessary for patients with positive sentinel lymph node biopsy(SLNB) receiving breast conserving surgery(BCS) with irradiation. However, consensus statements and guidelines until recently recommended that patients with mastectomy and tumor positive sentinel node undergo completion ALND. In this preliminary study, we compared these patients who did not undergo ALND with the patients who received BCS with SLNB only and irradiation and we analyzed the locoregional recurrence rate to show no differences of outcomes between two groups.

Method: We identified 6,163 women with invasive breast cancer who underwent surgical resection at the National Cancer Center (Goyang,Gyeonggi-do,Korea) between January 2000 to December 2011. Clinico-pathological data obtained from prospective collecting medical database of our institution were analyzed retrospectively. The mastectomy with positive SLNB group was 47 patients and BCS with positive SLNB and irradiation group was 172 patients. The primary end point was loco-regional recurrence rate.

Result : Clinical and tumor characteristics were similar between two groups except T stage and receptor status. The mean tumor size was 5.5cm with mastectomy group and 3.5cm with BCS group. The median number of nodes removed was three. There was not a single case of locoregional recurrence in both groups. At a median follow-up of 53.5 months (last follow-up, May 2013), 5-year overall survival was 85.7% with mastectomy and 97.3% with BCS group.

Conclusion : In our study, there was no case of locoregional recurrence as above. This results lend weight to the argument that SLNB without ALND may be reasonable management for selected patients with appropriate surgery and adjuvant systemic therapy. This study can be regarded as a preliminary study with a sufficient value despite of the prognosis showed some statistical differences between two groups. It resides in the difference of initial stage of patients of two groups. We will present additional data compared with the mastectomy with axillary clearance group at the meeting.

Acknowledgement This work was supported by grant from the National Cancer Center Korea (1210331-2).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-01-19.

Abstract P3-08-14: Could the preoperative systemic therapy be a risk factor for breast cancer-related lymphedema in stage II/III breast cancer?

Background: The breast cancer-related lymphedema (LE) has been known to be closely related to axillary lymph nodes dissection (ALND), chemotherapy, and radiation therapy. In this study, we evaluated whether the sequence of systemic chemotherapy and surgery could be a predictive factor in stage II/III breast cancer.

Methods and Materials: A total of 867 patients with stage II/III breast cancer, who underwent curative surgery with adequate systemic therapy from 2004 to 2009, were retrospectively analyzed. Adjuvant chemotherapy (ACT) was performed in 571 patients (65.9%) and preoperative systemic chemotherapy (PSC) in 296 (34.1%). We evaluated the incidence of LE by clinicopathologic factors and treatments.

Results: At a median follow-up of 5.1 years (range, 3.0-8.3 years), 360 patients (41.5%) had experienced LE, 244 patients have retained LE (permanent LE), and 116 patents were normalized. The overall 5-year cumulative incidence of LE was 17%. LE occurred in 188 patients (32.9%) in patients with ACT, 172 patients (58.1%) with PSC (P&lt;0.001), permanent LE in 121 (21.2%) with ACT, 123 (41.6%) with PSC (P&lt;0.001), respectively. Multivariate analysis showed that PSC (hazard ratio [HR], 1.65; P&lt;.001), radiotherapy (HR, 2.24; P&lt;0.01), ALND (HR, 1.41; P = 0.04), and nodal stage (HR, 1.93; P = 0.04) were independent risk factors for LE occurrence. For the permanent LE, PSC (HR, 1.44; P = 0.05), radiotherapy (HR, 2.79; P&lt;0.01), ALND (HR, 1.77; P&lt;0.01), and nodal stage (HR, 3.01; P = 0.02) showed the associations.

Conclusions: The risk factors associated with LE were advanced stage, ALND and radiotherapy. PSC was one of predictors for transients LE. However, further evaluation should be done whether it is a risk factor for permanent LE.

This research was supported by National Cancer Center Grant NCC-1210181-2 by the National Cancer Center, Republic of Korea.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-08-14.

Polyethylene glycol bowel preparation does not eliminate the risk of acute renal failure: a population-based case-crossover study

BACKGROUND AND STUDY AIMS

Polyethylene glycol (PEG) bowel preparations are regarded as effective and safe for colonoscopy; however, recent reports have indicated a risk of acute renal failure (ARF). This population-based case-crossover study evaluated the association between PEG and ARF in screening colonoscopy patients aged ≥ 50 years.

PATIENTS AND METHODS

Korean Health Insurance Review and Assessment Service (HIRA) claims data from 1 January 2005 to 31 December 2009 were used in the study. The study population consisted of patients aged ≥ 50 years who were first hospitalized for ARF following colonoscopy involving PEG bowel preparation. For each patient, PEG use in a 1-, 2-, or 4-week period prior to the first hospital admission date for ARF (hazard period) was compared with PEG use in four earlier 1-, 2-, or 4-week control periods. Conditional logistic regression analysis was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs), adjusting for concomitant medications that could induce ARF.

RESULTS

The total number of study patients was 1064 (59 % were male). A greater proportion of patients used PEG during the hazard period than during the control periods (for 4-week time window: 8.8 % vs. 3.2 %). The adjusted ORs for ARF incidence when applying the 1-, 2-, and 4-week periods were 3.1 (95 %CI 2.06 - 4.73), 2.5 (95 %CI 1.76 - 3.53), and 2.1 (95 %CI 1.61 - 4.85), respectively.

CONCLUSIONS

The use of PEG was associated with the risk of ARF. Adequate hydration and renal function monitoring should be assured before and after colonoscopy, regardless of the bowel preparation regimen used.

Establishment of isolation and expansion protocols for human cardiac C-kit-positive progenitor cells for stem cell therapy

Although cardiac stem cells (CSCs) have emerged in regeneration research, the number of isolated CSCs is low, making a sufficient supply of functional elements an important consideration in cardiovascular research. In this study, we established an efficient method for CSC isolation. We directly compared cultures of single cells to human cardiac-derived c-kit-positive progenitor cells (hCPCs(c-kit+)). The two protocols employed enzymatically digested hCPCs(c-kit+) (ED-hCPCs) with tissue-expanded hCPC(c-kit+) (TE-hCPCs). Using fluorescence-activated cell sorting, we showed the concentration of c-kit in TE-hCPCs to be higher than in ED-hCPCs, although the total number of c-kit positive cells resulting from ED-hCPCs was similar to that resulting from TE-hCPCs. The cardiomyocyte-associated proteins, GATA4 and Nkx2-5, which were expressed during hCPCs expansion, did not differ between the isolation methods. Importantly, the expression of the CSC stem cell marker, c-kit, was more efficiently preserved using the ED-hCPCs versus the TE-hCPCs method. In a cell proliferation assay, the ED-hCPCs method produced a significantly greater number of cells. Finally, hCPCs derived using both protocols differentiated into endothelial, smooth muscle, and cardiomyocyte lineages. In conclusion, the single-cell culture protocol using an enzymatic digestion method may be more useful to isolate human cardiac-derived c-kit-positive elements compared with the tissue expansion method.

CHK2 kinase promotes pre-mRNA splicing via phosphorylating CDK11(p110)

Checkpoint kinase 2 (CHK2) kinase is a key mediator in many cellular responses to genotoxic stresses, including ionizing radiation (IR) and topoisomerase inhibitors. Upon IR, CHK2 is activated by ataxia telangiectasia mutated kinase and regulates the S-phase and G1-S checkpoints, apoptosis and DNA repair by phosphorylating downstream target proteins, such as p53 and Brca1. In addition, CHK2 is thought to be a multi-organ cancer susceptibility gene. In this study, we used a tandem affinity purification strategy to identify proteins that interact with CHK2 kinase. Cyclin-dependent kinase 11 (CDK11)(p110) kinase, implicated in pre-mRNA splicing and transcription, was identified as a CHK2-interacting protein. CHK2 kinase phosphorylated CDK11(p110) on serine 737 in vitro. Unexpectedly, CHK2 kinase constitutively phosphorylated CDK11(p110) in a DNA damage-independent manner. At a molecular level, CDK11(p110) phosphorylation was required for homodimerization without affecting its kinase activity. Overexpression of CHK2 promoted pre-mRNA splicing. Conversely, CHK2 depletion decreased endogenous splicing activity. Mutation of the phosphorylation site in CDK11(p110) to alanine abrogated its splicing-activating activity. These results provide the first evidence that CHK2 kinase promotes pre-mRNA splicing via phosphorylating CDK11(p110).

Molecular epidemiology and genetic diversity of human astrovirus in South Korea from 2002 to 2007

The present study was conducted to survey the prevalence and genotypic distribution of human astrovirus (HAstV) circulating in South Korea. Of 160,027 patients with acute gastroenteritis, 2,057 (1.3%) were positive for HAstV antigen. We determined the genotypes of 187 HAstV strains collected from laboratories across the country. Genetic analysis revealed genotype 1 to be the most prevalent, accounting for 72.19% of the strains, followed by genotypes 8 (9.63%), 6 (6.95%), 4 (6.42%), 2 (3.21%) and 3 (1.60%). Our findings indicate that HAstV is less common but, even so, a potentially important viral agent of gastroenteritis in South Korea, with significant genetic diversity among circulating HAstV strains.

Lipid raft proteome reveals that oxidative phosphorylation system is associated with the plasma membrane

Although accumulating proteomic analyses have supported the fact that mitochondrial oxidative phosphorylation (OXPHOS) complexes are localized in lipid rafts, which mediate cell signaling, immune response and host-pathogen interactions, there has been no in-depth study of the physiological functions of lipid-raft OXPHOS complexes. Here, we show that many subunits of OXPHOS complexes were identified from the lipid rafts of human adipocytes, C2C12 myotubes, Jurkat cells and surface biotin-labeled Jurkat cells via shotgun proteomic analysis. We discuss the findings of OXPHOS complexes in lipid rafts, the role of the surface ATP synthase complex as a receptor for various ligands and extracellular superoxide generation by plasma membrane oxidative phosphorylation complexes.

TRIM72, a novel negative feedback regulator of myogenesis, is transcriptionally activated by the synergism of MyoD (or myogenin) and MEF2

TRIM72 is known to be involved in the negative feedback regulation of myogenesis by targeting insulin receptor substrate-1. Here, we found that TRIM72 was more highly expressed in oxidative muscle with the higher activity of MEF2, compared to glycolytic muscle. Indeed, TRIM72 promoter contained an evolutionarily conserved MEF2 site juxtaposed to E-box. TRIM72 promoter activity was decreased by the site-directed mutagenesis of either E-boxes or a MEF2 site and synergistically enhanced by MyoD (or myogenin) and MEF2, which were associated with proximal E-box, and MEF2 site of the TRIM72 promoter, respectively. Taken together all these data, we concluded that the synergism of MyoD (or myogenin) and MEF2 is necessary for TRIM72 expression during C2C12 differentiation.

E/E' ratio is more sensitive than E/A ratio for detection of left ventricular diastolic dysfunction in patients with systemic sclerosis

OBJECTIVES

To investigate the efficiency of early filling (E) and early diastolic mitral annular velocity (E') ratio (E/E' ratio) assessed by tissue Doppler imaging (TDI) on early detection of diastolic left ventricular (LV) dysfunction in systemic sclerosis (SSc) patients without congestive heart failure (CHF) symptoms.

METHODS

Thirty-five Korean SSc patients without CHF symptoms and 35 healthy, age-sex matched controls were studied. Two-dimensional and M-mode echocardiography including conventional and tissue Doppler imaging was performed and pulmonary function test with diffusing capacity of lung for carbon monoxide was assessed.

RESULTS

Mean E and late filling (A) ratio (E/A ratio) showed no significant difference between the two groups, while TDI showed that SSc patients had significantly elevated E/E' ratio (10.6+/-4.2 vs. 8.8+/-2.2, p=0.032), in comparison with controls. SSc patients who had taken angiotensin converting enzyme inhibitor or angiotensin II receptor blocker had significantly lower E/E' than those who had not (8.0+/-2.4 vs. 11.9+/-4.3, p=0.01).

CONCLUSIONS

E/E' ratio is more sensitive than E/A ratio for identifying LV diastolic dysfunction in SSc patients without CHF symptoms. Furthermore, SSc patients who had received ACEI or ARB treatment showed significantly better preservation of LV diastolic function than those who had not received these medications.

Effects of bisphosphonate on the endochondral bone formation of the mandibular condyle

The development of the mandibular condylar cartilage is important for the overall growth of the mandible. However, there have been a few researches into medical approaches aimed at controlling condylar growth. This study examined the effects of bisphosphonate on the growth of the condylar cartilage. Alendronate (3.5 mg/kg/week) was administered to postnatal day 1 SD rats for 7 and 10 days. The thickness of each chondrocyte layer and the level of MMP-9 expression were measured. The anteroposterior diameter of the developing condyle was unaffected by the alendronate treatment for 7 days (P > 0.05). The total thickness of the cartilage layers was also unaffected by the treatment for 7 days (P > 0.05). In particular, there was no change in the thickness of the perichondrium and reserve cell layer at the measured condylar regions (P > 0.05). However, the thickness of the proliferating cell layer was reduced significantly, whereas the thickness of hypertrophied cartilage layer was increased (P < 0.05). The number of chondroclasts engaged in hypertrophied cartilage resorption was reduced significantly by the alendronate treatment (P < 0.05). The level of MMP-9 expression was reduced at both the transcription and translation levels by the alendronate treatment for 7 and 10 days. These results indicate that alendronate (>3.5 mg/kg/week) inhibits the longitudinal growth of the mandibular condyle by inhibiting chondrocyte proliferation and the resorption of hypertrophied cartilage for ossification.

A two-photon fluorescent probe for lipid raft imaging: C-laurdan

The lipid-rafts hypothesis proposes that naturally occurring lipid aggregates exist in the plane of membrane that are involved in signal transduction, protein sorting, and membrane transport. To understand their roles in cell biology, a direct visualization of such domains in living cells is essential. For this purpose, 6-dodecanoyl-2-(dimethylamino)naphthalene (laurdan), a membrane probe that is sensitive to the polarity of the membrane, has often been used. We have synthesized and characterized 6-dodecanoyl-2-[N-methyl-N-(carboxymethyl)amino]naphthalene (C-laurdan), which has the advantages of greater sensitivity to the membrane polarity, a brighter two-photon fluorescence image, and reflecting the cell environment more accurately than laurdan. Lipid rafts can be visualized by two-photon microscopy by using C-laurdan as a probe. Our results show that the lipid rafts cover 38 % of the cell surface.

An Efficient Adaptive Feedback cancellation using by Independent component analysis for hearing aids

In this paper, we proposed a feedback cancellation algorithm based on independent component analysis (ICA) for digital hearing aids. In conventional adaptive feedback cancelling systems, the normalized least mean squares (NLMS) algorithm used to reduce acoustic feedback in which hearing aids occurs, generally at high gains. But primary input signal depend on the acoustic feedback signal in higher-order statistics, proposed algorithm was better acoustic feedback cancelling performance than the conventional NLMS algorithm when the input signal has a Laplacian distribution with high-order processing in real-time simulation of TMS320C 6711 DSK.

Oxidation-reduction respiratory chains and ATP synthase complex are localized in detergent-resistant lipid rafts

In order to detect and identify ubiquitous lipid raft marker proteins, we isolated lipid rafts from different mouse organs, including the liver, lung, large brain, and kidney, and analyzed their proteins via 2-DE. Many protein spots were determined to be ubiquitous in all of the lipid rafts, and were annotated via LC and MS/MS. Twelve proteins were identified as ubiquitous raft proteins, and most of these were determined to be mitochondrial proteins, including mortalin, prohibitin, voltage-dependent anion channel, ATP synthase, NADH dehydrogenase, and ubiquinol-cytochrome c reductase. Via immunoblotting, these proteins were shown to exist in detergent-resistant lipid rafts prepared using different organ tissues. Since these oxidation-reduction respiratory chains and ATP synthase complex were detected in detergent-resistant lipid raft fractions which had been isolated from the plasma membrane but not from the mitochondria, and found in the cell surface when determined by immunofluoresence and immunohistochemistry, we conclude that plasma membrane lipid rafts might contain oxidation-reduction respiratory chains and ATP synthase complex.

Anti-endothelial cell antibodies and antiphospholipid antibodies in Takayasu's arteritis: correlations of their titers and isotype distributions with disease activity

OBJECTIVE

To investigate the prevalence of anti-endothelial cell antibodies (AECA) and antiphospholipid antibodies, and the correlations of their isotype distributions and titers with disease activity in patients with Takayasu's arteritis (TA).

METHODS

Forty-seven patients with TA and 30 age- and sex-matched controls were studied. Blood samples were obtained from all patients and they were divided into either active or stable disease groups. Paired samples were available in 18 patients at both active and stable stage, respectively. AECA against human umbilical vein endothelial cells and antiphospholipid antibodies were measured.

RESULTS

Forty-two (89.4%) TA patients had AECA, and positivity rates of IgM and IgG AECA were 83.0% and 68.1%, respectively, while those for controls were both 3.3%. The titers of IgM and IgG AECA in patients were significantly higher than those in controls. IgM AECA titers of the active group were significantly higher than those of the stable group, but IgG AECA titers were not. In 18 patients with paired samples, IgM AECA titers at active stage were significantly higher than those at stable stage, but IgG AECA titers were not different between stages. The changes of IgM AECA titers correlated well with those of ESR levels between stages. Antiphospholipid antibodies were detected in only 4 patients with TA, but not in controls.

CONCLUSION

IgM AECA and IgG AECA were more prevalent and their titers were higher in patients with TA than in controls, and IgM AECA titers correlated well with the disease activity of TA. Antiphospholipid antibodies were not found significant.

Effects of Na+-Ca2+ exchanger activity on the alpha-amino-3-hydroxy-5-methyl-4-isoxazolone-propionate-induced Ca2+ influx in cerebellar Purkinje neurons

Variations in intracellular calcium activity ([Ca2+]i) play crucial roles in information processing in Purkinje neurons such as synaptic plasticity. Although Na+-Ca2+ exchanger (NCX) has been shown to participate in the regulation of homeostasis and secretion in neuronal cells, the physiological role of NCX in Purkinje neurons, such as a role in cerebellar synaptic plasticity, is not well understood. NCX in acutely dissociated rat Purkinje neurons was identified by double staining with anti-calbindin D-28k antibody and anti-NCX antibody. The physiological activity of NCX was examined by measuring transient intracellular Ca2+ changes resulting from the Ca2+ influx via reverse mode of NCX (with 0 mM Na+/2.5 mM Ca2+ solutions) and the efflux via the forward mode of NCX (with 140 mM Na+/0 mM Ca2+ solutions). This transient increase in Ca2+ concentration was not elicited in the cells pretreated with NCX antisense oligodeoxynucleotides. And the Ca2+ influx resulting from the reverse mode of NCX was significantly reduced by 2-[2-[4-(4-nitrobenyloxy) phenyl] ethyl] isothiourea methanesulfonate, while the Ca2+ efflux via forward mode was inhibited by bepridil. The physiological role of NCX in synaptic function was studied by measuring Ca2+ transients induced by alpha-amino-3-hydroxy-5-methyl-4-isoxazolone-propionate (AMPA) receptor activation. This AMPA-evoked response was decreased with the inhibition of NCX forward mode and also, to less degree, with the inhibition of reverse mode. In antisense oligodeoxynucleotides pretreated cells, the AMPA-evoked response was also reduced, as was the case in NCX-inhibitor treated cells. The inhibition of NCX activity had depressant effects on Ca2+ transients induced by AMPA receptor activation. These results suggest that NCX plays a physiological role in modulating the activity of cerebellar Purkinje neurons, such as synaptic plasticity, via interaction with AMPA receptors in Purkinje neurons.

Risk of ovarian failure and pregnancy outcome in patients with lupus nephritis treated with intravenous cyclophosphamide pulse therapy

This study was designed to investigate the risk of ovarian failure and the pregnancy outcomes in women treated with intravenous cyclophosphamide (IVCYC) pulse therapy for lupus nephritis. Sixty-seven women with proliferative lupus nephritis were studied. The clinical and laboratory data, SLEDAI and damage indices at IVCYC initiation, doses and numbers of IVCYC pulses, pregnancy and fetal outcomes were evaluated. During a follow-up of 74.4+/-20.6 months, amenorrhea occurred in 25 (37.3%) and was sustained permanently in 10 patients (14.9%). Thirteen women became pregnant with a total of 19 pregnancies. Seventeen pregnancies ended without complications and all babies were born healthy without any congenital anomalies or perinatal illnesses. Two pregnancies were terminated by induced abortion but no congenital anomaly was noted in these cases. Logistic regression analysis showed that old age, high damage index at the initiation of IVCYC pulse therapy and high cumulative dosage of IVCYC were the independent risk factors of ovarian failure, and that the presence of amenorrhea, regardless of its duration, was the risk factor of pregnancy failure. Pregnancy was possible with a favorable outcome after the withdrawal of IVCYC pulse therapy, unless amenorrhea develops.

Effects of ginsenosides on vanilloid receptor (VR1) channels expressed in Xenopus oocytes

Ginsenosides, or ginseng saponins, are biologically active ingredients of Panax ginseng. Accumulating evidence suggests that ginsenosides can alleviate pain from injections of noxious chemicals, such as capsaicin [Nah et al. (2000)]. In this study we examined the effects of ginsenoside Rc on the capsaicin-induced inward current in Xenopus oocytes that expresses the vanilloid receptor 1 (VR1). Ginsenoside Rc enhanced the capsaicin-induced inward current in a concentration-dependent and reversible manner, but ginsenoside Rc itself elicited no membrane currents. The VR1 antagonist capsazepine almost completely blocked the inward current that was elicited by capsaicin plus ginsenoside Rc. We also tested the effect of seven other fractionated ginsenosides (i.e., Rb1, Rb2, Rd, Re, Rf, Rg1, and Rg2) in addition to ginsenoside Rc. We found that six of them significantly enhanced the inward current that is induced by capsaicin with the following order of potency: Rc > Rf > Rg1 approximately Rd > Rb2 > Rb1. These results show the possibility that the in vivo effect of ginsenosides against capsaicin-induced pain is derived from their modulation of the VR1 channel function.

Diphyllobothrium latum infection after eating domestic salmon flesh

Diphyllobothrium latum infection in human is not common in Korea and only thirty seven cases have been reported since 1921. We report two cases of fish tapeworm infection after ingestion of raw cherry salmon (Oncorhynchus masou) caught in the domestic river. Among four family members who ate together raw salmon flesh six months ago, just two, mother and daughter, were infected. It is our expectation that the salmon associated tapeworm infections would be enlisted as one of the major parasitic problems with the growing consumption of salmon in Korea.

Cytopathic changes in rat microglial cells induced by pathogenic Acanthamoeba culbertsoni: morphology and cytokine release

To determine whether pathogenic Acanthamoeba culbertsoni trophozoites and lysate can induce cytopathic changes in primary-culture microglial cells, morphological changes were observed by transmission electron microscopy (TEM). In addition, the secretion of two kinds of cytokines, tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta), from microglial cells was observed. Trophozoites of pathogenic A. culbertsoni made contact with microglial cells and produced digipodia. TEM revealed that microglial cells cocultured with amoebic trophozoites underwent a necrotic process, accompanied by lysis of the cell membrane. TEM of microglial cells cocultured with amoebic lysate showed that the membranes of the small cytoplasmic vacuoles as well as the cell membrane were lysed. The amounts of TNF-alpha secreted from microglial cells cocultured with A. culbertsoni trophozoites or lysate increased at 6 h of incubation. The amounts of IL-1beta secreted from microglial cells cocultured with A. culbertsoni trophozoites at 6 h of incubation was similar to those secreted from the control group, but the amounts decreased during cultivation with A. culbertsoni lysate. These results suggest that pathogenic A. culbertsoni induces the cytopathic effects in primary-culture rat microglial cells, with the effects characterized by necrosis of microglial cells and changes in levels of secretion of TNF-alpha and IL-1beta from microglial cells.

A novel activation of Ca(2+)-activated Cl(-) channel in Xenopus oocytes by Ginseng saponins: evidence for the involvement of phospholipase C and intracellular Ca(2+) mobilization

1. The signal transduction mechanism of ginsenosides, the active ingredients of ginseng, was studied in Xenopus oocytes using two-electrode voltage-clamp technique. Ginseng total saponin (GTS), i.e., an unfractionated mixture of ginsenosides produced a large outward current at membrane potentials more positive than -20 mV when it was applied to the exterior of oocytes, but not when injected intracellularly. The effect of GTS was concentration-dependent (EC(50): 4.4 microg ml(-1)) and reversible. 2. Certain fractionated ginsenosides (Rb(1), Rb(2), Rc, Rf, Rg(2) and Ro) also produced an outward current in a concentration-dependent manner with the order of potency of Rf>Ro>Rb(1)=Rb(2)>Rg(2)>Rc. Other ginsenosides (Rd, Re and Rg(1)) had little or no effect. 3. The GTS effect was completely blocked by bath application of the Ca(2+)-activated Cl(-) channel blocker niflumic acid and by intracellular injection of the calcium chelator BAPTA or the IP(3) receptor antagonist heparin. Also, the effect was partially blocked by bath-applied U-73122, a phospholipase C (PLC) inhibitor and by intracellularly injected GTP gamma S, a non-hydrolyzable GTP analogue. Whereas, it was not altered by pertussin toxin (PTX) pretreatment. 4. These results indicate that: (1) interaction of ginsenosides with membrane component(s) at the extracellular side leads to Ca(2+)-activated Cl(-) channel opening in Xenopus oocyte membrane; and (2) this process involves PLC activation, the release of Ca(2+) from the IP(3)-sensitive intracellular store and PTX-insensitive G protein activation.

Two distinct nuclear receptor-interaction domains and CREB-binding protein-dependent transactivation function of activating signal cointegrator-2

ASC-2 is a recently isolated transcriptional cointegrator molecule, which is amplified in human cancers and stimulates transactivation by nuclear receptors, AP-1, nuclear factor kappaB (NFkappaB), serum response factor (SRF), and numerous other transcription factors. ASC-2 contained two nuclear receptor-interaction domains, both of which are dependent on the integrity of their core LXXLL sequences. Surprisingly, the C-terminal LXXLL motif specifically interacted with oxysterol receptor LXRss, whereas the N-terminal motif bound a broad range of nuclear receptors. These interactions appeared to be essential because a specific subregion of ASC-2 including the N- or C-terminal LXXLL motif acted as a potent dominant negative mutant with transactivation by appropriate nuclear receptors. In addition, the autonomous transactivation domain (AD) of ASC-2 was found to consist of three separable subregions; i.e. AD1, AD2, and AD3. In particular, AD2 and AD3 were binding sites for CREB binding protein (CBP), and CBP-neutralizing E1A repressed the autonomous transactivation function of ASC-2. Furthermore, the receptor transactivation was not enhanced by ASC-2 in the presence of E1A and significantly impaired by overexpressed AD2. From these results, we concluded that ASC-2 directly binds to nuclear receptors and recruits CBP to mediate the nuclear receptor transactivation in vivo.

Differentiation of hamster liver oval cell following Clonorchis sinensis infection

Oval cells which appear in the liver after hepatic injuries are suspected to be progenitor cells for both hepatocytes and bile duct cells. Oval cell isolated from the livers of the hamsters treated with diethylnitrosamine and 2-acetylaminofluorene and infected with Clonorchis sinensis (CS). cultured for 2 weeks and evaluated for differentiation and plasticity by electron microscopy and immunohistochemistry. In the CS-uninfected group, glycogen granules and peroxisomes were noted in the cells that were cultured for 2 weeks. Starting at 1 week postculture, immunoreactivity of the cells to cytokeratin 19 markedly decreased but that to albumin and alpha-fetoprotein gradually increased. This means that oval cells isolated from hamsters that were not infected with CS differentiated toward hepatocyte lineage. However, in the CS-infected group, cultured cells contained numerous rough endoplasmic reticulum and showed immunoreactivity that was generally in reverse to that of CS-uninfected group, meaning that cells isolated following CS infection were primed by CS and differentiated toward bile duct cell lineage. The results of this study suggested that oval cells are indeed bipolar progenitor cells for hepatocytes and bile duct cells and can differentiate toward either lineage depending upon the priming factor.