Publications by authors named "Shen-Long Howng"

91 Publications

The origin of GSKIP, a multifaceted regulatory factor in the mammalian Wnt pathway.

Biochim Biophys Acta Mol Cell Res 2018 08 23;1865(8):1046-1059. Epub 2018 Apr 23.

Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan; Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. Electronic address:

GSK3β interacting protein (GSKIP) is a naturally occurring negative regulator of GSK3β and retains both the Protein Kinase A Regulatory subunit binding (PKA-RII) domain and GSK3β interacting domain. Of these two domains, we found that PKA-RII is required for forming a working complex comprising PKA/GSKIP/GSK3β/Drp1 to influence phosphorylation of Drp1 Ser637. In this study, bioinformatics and experimental explorations re-analyzing GSKIP's biofunctions suggest that the evolutionarily conserved Domain of Unknown Function (DUF727) is an ancestral prototype of GSKIP in prokaryotes, and acquired the C-terminal GSK3β binding site (tail) in invertebrates except for Saccharomyces spp., after which the N-terminal PKA-RII binding region (head) evolved in vertebrates. These two regions mutually influence each other and modulate GSKIP binding to GSK3β in yeast two-hybrid assays and co-immunoprecipitation. Molecular modeling showed that mammalian GSKIP could form a dimer through the L130 residue (GSK3β binding site) rather than V41/L45 residues. In contrast, V41/L45P mutant facilitated a gain-of-function effect on GSKIP dimerization, further influencing binding behavior to GSK3β compared to GSKIP wild-type (wt). The V41/L45 residues are not only responsible for PKA RII binding that controls GSK3β activity, but also affect dimerization of GSKIP monomer, with net results of gain-of-function in GSKIP-GSK3β interaction. In addition to its reported role in modulating Drp1, Ser637 phosphorylation caused mitochondrial elongation; we postulated that GSKIP might be involved in the Wnt signaling pathway as a scavenger to recruit GSK3β away from the β-catenin destruction complex and as a competitor to compete for GSK3β binding, resulting in accumulation of S675 phosphorylated β-catenin.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbamcr.2018.04.008DOI Listing
August 2018

AIBp regulates mitotic entry and mitotic spindle assembly by controlling activation of both Aurora-A and Plk1.

Cell Cycle 2015 26;14(17):2764-76. Epub 2015 Jun 26.

a Department of Biochemistry ; Faculty of Medicine; College of Medicine; Kaohsiung Medical University ; Kaohsiung , Taiwan.

We previously reported that Aurora-A and the hNinein binding protein AIBp facilitate centrosomal structure maintenance and contribute to spindle formation. Here, we report that AIBp also interacts with Plk1, raising the possibility of functional similarity to Bora, which subsequently promotes Aurora-A-mediated Plk1 activation at Thr210 as well as Aurora-A activation at Thr288. In kinase assays, AIBp acts not only as a substrate but also as a positive regulator of both Aurora-A and Plk1. However, AIBp functions as a negative regulator to block phosphorylation of hNinein mediated by Aurora-A and Plk1. These findings suggest a novel AIBp-dependent regulatory machinery that controls mitotic entry. Additionally, knockdown of hNinein caused failure of AIBp to target the centrosome, whereas depletion of AIBp did not affect the localization of hNinein and microtubule nucleation. Notably, knockdown of AIBp in HeLa cells impaired both Aurora-A and Plk1 kinase, resulting in phenotypes with multiple spindle pole formation and chromosome misalignment. Our data show that depletion of AIBp results in the mis-localization of TACC3 and ch-TOG, but not CEP192 and CEP215, suggesting that loss of AIBp dominantly affects the Aurora-A substrate to cause mitotic aberrations. Collectively, our data demonstrate that AIBp contributes to mitotic entry and bipolar spindle assembly and may partially control localization, phosphorylation, and activation of both Aurora-A and Plk1 via hNinein during mitotic progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/15384101.2015.1066536DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614063PMC
June 2016

GSKIP- and GSK3-mediated anchoring strengthens cAMP/PKA/Drp1 axis signaling in the regulation of mitochondrial elongation.

Biochim Biophys Acta 2015 Aug 25;1853(8):1796-807. Epub 2015 Apr 25.

Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan; Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. Electronic address:

GSK3β binding of GSKIP affects neurite outgrowth, but the physiological significance of PKA binding to GSKIP remains to be determined. We hypothesized that GSKIP and GSK3β mediate cAMP/PKA/Drp1 axis signaling and modulate mitochondrial morphology by forming a working complex comprising PKA/GSKIP/GSK3β/Drp1. We demonstrated that GSKIP wild-type overexpression increased phosphorylation of Drp1 S637 by 7-8-fold compared to PKA kinase-inactive mutants (V41/L45) and a GSK3β binding-defective mutant (L130) under H2O2 and forskolin challenge in HEK293 cells, indicating that not only V41/L45, but also L130 may be involved in Drp1-associated protection of GSKIP. Interestingly, silencing either GSKIP or GSK3β but not GSK3α resulted in a dramatic decrease in Drp1 S637 phosphorylation, revealing that both GSKIP and GSK3β are required in this novel PKA/GSKIP/GSK3β/Drp1 complex. Moreover, overexpressed kinase-dead GSK3β-K85R, which retains the capacity to bind GSKIP, but not K85M which shows total loss of GSKIP-binding, has a higher Drp1 S637 phosphorylation similar to the GSKIP wt overexpression group, indicating that GSK3β recruits Drp1 by anchoring rather than in a kinase role. With further overexpression of either V41/L45P or the L130P GSKIP mutant, the elongated mitochondrial phenotype was lost; however, ectopically expressed Drp1 S637D, a phosphomimetic mutant, but not S637A, a non-phosphorylated mutant, restored the elongated mitochondrial morphology, indicating that Drp1 is a downstream effector of direct PKA signaling and possibly has an indirect GSKIP function involved in the cAMP/PKA/Drp1 signaling axis. Collectively, our data revealed that both GSKIP and GSK3β function as anchoring proteins in the cAMP/PKA/Drp1 signaling axis modulating Drp1 phosphorylation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbamcr.2015.04.013DOI Listing
August 2015

Bcl2L12 with a BH3-like domain in regulating apoptosis and TMZ-induced autophagy: a prospective combination of ABT-737 and TMZ for treating glioma.

Int J Oncol 2015 Mar 13;46(3):1304-16. Epub 2015 Jan 13.

Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan, R.O.C.

Bcl2L12 as a new member of the Bcl2 family, which contains a BH2 domain and shares a lower amino acid similarity with other Bcl2 family proteins. Bcl2L12 is reported to be involved in apoptosis regulation, but this role remains controversial in different cancer type. Temozolomide (TMZ) is currently used to intervene glioma multiforme (GBM), but an acquired chemotherapeutic resistance maybe occurred due to undesired autophagy. Previous studies uncovered that Bcl2L12 may interact with Bcl-xL and may harbor a BH3-like domain. Therefore, we investigated whether this BH3-like domain is responsible for the Bcl2L12 anti-apoptotic property. Moreover, we tested whether ABT-737, a BH3 mimetic agent, can be combined with TMZ to treat GBM. We aligned Bcl2L12 with Bcl2 family members, compared interacting pattern of BH3 domain and their protein 3D structure. We identified that Bcl2L12 interacts with Bcl-xL and Bcl2 in yeast two-hybrid system. Bcl2L12192-220 was a minimal region for Bcl2L12-Bcl-xL interaction. Five-point mutations with respect to hydrophobic and charge residues were generated to test whether they are the key residue of BH3-like domain. Our data showed that both h1 (L213) and h2 residue (L217) are essential for Bcl2L12 interacting with Bcl2 family proteins. Ectopically expressed h1 or h2 mutant in U87MG cell line resulted in reactivation of cleaved-PARP, caspase-3 and cytochrome c releasing compared to Bcl2L12 wt group. Implementing ABT-737 combined with TMZ provided a superior effect on apoptosis induction in Bcl2L12 wt group, which effectively reactivated apoptotic markers. Altogether, our findings indicated that Bcl2L12 retains a BH3-like domain, which is important for the Bcl2L12 anti-apoptotic property and TMZ-induced autophagy. Our results basically support the idea of using ABT-737 to counteract the anti-apoptotic role of Bcl2L12 and sensitize drug response of the GBM cells to TMZ.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ijo.2015.2838DOI Listing
March 2015

Association of Aurora A and gamma-tubulin expression in astrocytomas and patient survival.

Neurol Res 2014 Aug 14;36(8):746-51. Epub 2014 Jan 14.

Objectives: The purpose was to evaluate the association of Aurora A and gamma-tubulin expression with disease characteristics and survival in patients with astrocytoma.

Methods: This is a retrospective study of patients who had surgical specimens that were pathologically diagnosed as astrocytoma. The expression level of Aurora A and gamma-tubulin in tumor tissue was evaluated by immunohistochemistry. Clinical information, Karnofsky performance status scale, and survival status of patients were collected.

Results: We found that high protein levels of gamma-tubulin or Aurora A were associated with patients 45 years of age, high tumor grade, more advanced non-fully resectable tumors, and poorer survival status. The survival time for patients whose tumors had high gamma-tubulin and Aurora A expression was about 12 months compared with approximately 41 months for patients with low levels of expression of these proteins. Poor patient performance status following resection was also associated with high levels of gamma-tubulin and Aurora A expression.

Discussion: The expression levels of gamma-tubulin or Aurora A kinase were associated with patients' age, astrocytoma grade, respectability, as well as patient survival and performance. These findings support the idea that these factors may potentially be important prognostic indicators for patients with astrocytomas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1179/1743132813Y.0000000310DOI Listing
August 2014

Arrested growth and spontaneous tumor regression of partially resected low-grade cerebellar astrocytomas in children.

Childs Nerv Syst 2013 Nov 1;29(11):2051-5. Epub 2013 May 1.

Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, No 100 Tzyou 1 Rood, Kaohsiung, 807, Taiwan.

Purpose: The prognosis of children with low-grade cerebellar astrocytoma who have partial resection of tumor is largely unpredictable. The purpose of this study was to review the long-term outcome of such patients.

Methods: The medical charts, imaging findings, operative notes, histopathological reports, and survival times of 12 patients with cerebellar astrocytoma were reviewed.

Results: Five patients had total resection and seven had partial resection. Nine patients had grade I histology and three patients had grade II. Follow-up duration ranged from 3 to 25 years. Among the seven patients with residual tumor, five had tumor progression, one had arrested tumor growth, and one had spontaneous tumor regression. Five patients with partial resection received radiotherapy and three had malignant transformation of tumor during follow-up. Six patients, including five who had partial resection, underwent a second operation. One patient with partial resection died of pneumonia 23 years after surgery.

Conclusions: Patients with complete tumor resection had a better prognosis than patients with partial resection. For patients with partial resection, we recommend a "wait and see" policy with surveillance using MRI. The phenomenon of arrested tumor growth and spontaneous tumor regression in patients with cerebellar astrocytoma who have subtotal resection warrants further study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00381-013-2113-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3825417PMC
November 2013

Are there differential deficits in facial emotion recognition between paranoid and non-paranoid schizophrenia? A signal detection analysis.

Psychiatry Res 2013 Oct 15;209(3):424-30. Epub 2013 Apr 15.

Department of Psychiatry, Chi Mei Medical Center, Tainan, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

This study assessed facial emotion recognition abilities in subjects with paranoid and non-paranoid schizophrenia (NPS) using signal detection theory. We explore the differential deficits in facial emotion recognition in 44 paranoid patients with schizophrenia (PS) and 30 non-paranoid patients with schizophrenia (NPS), compared to 80 healthy controls. We used morphed faces with different intensities of emotion and computed the sensitivity index (d') of each emotion. The results showed that performance differed between the schizophrenia and healthy controls groups in the recognition of both negative and positive affects. The PS group performed worse than the healthy controls group but better than the NPS group in overall performance. Performance differed between the NPS and healthy controls groups in the recognition of all basic emotions and neutral faces; between the PS and healthy controls groups in the recognition of angry faces; and between the PS and NPS groups in the recognition of happiness, anger, sadness, disgust, and neutral affects. The facial emotion recognition impairment in schizophrenia may reflect a generalized deficit rather than a negative-emotion specific deficit. The PS group performed worse than the control group, but better than the NPS group in facial expression recognition, with differential deficits between PS and NPS patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.psychres.2013.03.026DOI Listing
October 2013

Plasma levels of transforming growth factor-beta 1 before and after removal of low- and high-grade astrocytomas.

Cytokine 2013 Feb 20;61(2):413-8. Epub 2012 Dec 20.

Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.

Transforming growth factor-beta 1 (TGF-β1) has been reported to be a possible marker for a number of tumors, including brain tumors. The aim of this study was to measure the plasma levels of TGF-β1 in patients with low- and high-grade astrocytomas before and after surgery. This prospective study included 14 patients with low-grade astrocytomas and 25 with high-grade astrocytomas who underwent tumor removal and 13 controls (patients who underwent cranioplasty for skull bone defects). Plasma levels of TGF-β1 were measured in all subjects using enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve analysis showed that when the level of TGF-β1 before tumor removal was ≥ 2.52 ng/ml, astrocytoma was predicted with a sensitivity of 94.9% and specificity of 100%. The mean plasma level of TGF-β1 in both the low-grade and high-grade astrocytoma groups significantly decreased after tumor removal (p<0.05); there was no significant change in TGF-β1 plasma level of the controls following surgery. Patients with high-grade astrocytomas had a significantly higher mortality rate than patients with low-grade astrocytomas (p=0.019) and significantly shorter survival (p=0.008). A positive correlation between TGF-β1 level after tumor removal and tumor volume was only found in the high-grade astrocytoma group (γ=0.597, p=0.002). The findings show that plasma TGF-β1 level was increased in patients with low-grade and high-grade astrocytoma, and that the levels significantly decreased after tumor removal in both groups. The results provide additional evidence that TGF-β1 might be useful as a tumor marker for astrocytomas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cyto.2012.11.011DOI Listing
February 2013

GSK3beta-mediated Drp1 phosphorylation induced elongated mitochondrial morphology against oxidative stress.

PLoS One 2012 20;7(11):e49112. Epub 2012 Nov 20.

Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.

Multiple phosphorylation sites of Drp1 have been characterized for their functional importance. However, the functional consequence of GSK3beta-mediated phosphorylation of Drp1 remains unclear. In this report, we pinpointed 11 Serine/Threonine sites spanning from residue 634~736 of the GED domain and robustly confirmed Drp1 Ser693 as a novel GSK3beta phosphorylation site. Our results suggest that GSK3beta-mediated phosphorylation at Ser693 does cause a dramatic decrease of GTPase activity; in contrast, GSK3beta-mediated phosphorylation at Ser693 appears not to affect Drp1 inter-/intra-molecular interactions. After identifying Ser693 as a GSK3beta phosphorylation site, we also determined that K679 is crucial for GSK3beta-binding, which strongly suggests that Drp1 is a novel substrate for GSK3beta. Thereafter, we found that overexpressed S693D, but not S693A mutant, caused an elongated mitochondrial morphology which is similar to that of K38A, S637D and K679A mutants. Interestedly, using H89 and LiCl to inhibit PKA and GSK3beta signaling, respectively, it appears that a portion of the elongated mitochondria switched to a fragmented phenotype. In investigating the biofunctionality of phosphorylation sites within the GED domain, cells overexpressing Drp1 S693D and S637D, but not S693A, showed an acquired resistance to H(2)O(2)-induced mitochondrial fragmentation and ensuing apoptosis, which affected cytochrome c, capase-3, -7, and PARP, but not LC3B, Atg-5, Beclin-1 and Bcl2 expressions. These results also showed that the S693D group is more effective in protecting both non-neuronal and neuronal cells from apoptotic death than the S637D group. Altogether, our data suggest that GSK3beta-mediated phosphorylation at Ser693 of Drp1 may be associated with mitochondrial elongation via down-regulating apoptosis, but not autophagy upon H(2)O(2) insult.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0049112PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3502545PMC
May 2013

Differential expression of centrosome-associated proteins in human brain tumors: a possible role of hNinein isoform 6 in cell differentiation.

Biofactors 2012 Nov-Dec;38(6):470-7. Epub 2012 Oct 10.

Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.

Dysregulated centrosomal expression has been observed in high grade gliomas. Thus, this study aimed to examine the expression of Aurora family kinase and various centrosomal proteins, including centrin, γ-tubulin, and hNinein isoforms, in human brain tumors, including 29 meningiomas, 34 astrocytomas, 6 pituitary adenomas, and 6 metastatic tumors. mRNA expression was evaluated using reverse transcription polymerase chain reaction. The role of hNinein isoform 6 expression in cell differentiation was assessed in BrdU-treated IMR-32 cells. Differential expression of centrosomal proteins of brain tumors and cell lines was observed. Specifically, centrin 2 and centrin 3 expression levels were classified as moderate or abundant in >97% of samples in the meningioma group, 63% of astrocytomas, >83% of metastatic and pituitary tumors. Alternatively, hNinein isoform 6 expression was only detected in normal brain and astrocytoma tumors (17/34); however, it was not expressed in meningioma (0/29), metastatic tumors (0/6) (P < 0.001). Of the six neuroblastoma cell lines analyzed only IMR-32 cells expressed hNinein isoform 6. Furthermore, downregulated expression of hNinein isoform 6 and upregulation of γ-tubulin was correlated to astrocytoma tumor grade (P < 0.001). Increased hNinein isoform 6 mRNA expression was observed in response to BrdU treatment, and its expression was greater in teratomas as compared to embryonic stem cells. Further studies are necessary to determine if hNinein isoform 6 functions as a tumor-suppressor gene in brain tumors. Differential centrosomal protein expression may result in altered centrosome function that is observed the in progression of various brain tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/biof.1053DOI Listing
November 2013

The alteration of plasma TGF-β1 levels in patients with brain tumors after tumor removal.

Kaohsiung J Med Sci 2012 Jun 4;28(6):316-21. Epub 2012 Apr 4.

Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.

Transforming growth factor (TGF) β1 may be a candidate for a serologic tumor marker. In this study, the plasma levels of TGF-β1 in patients with brain tumors were measured using enzyme-linked immunosorbent assay before and after tumor removal. Patients were divided into four groups, the control group and the benign, malignant, and metastatic brain tumor groups. All brain tumor groups showed significant increases in the levels of TGF-β1 before tumor removal (6.36 ± 3.94, 17.0 ± 9.7, and 12.2 ± 10.3 ng/ml for the benign, malignant, and metastatic groups, respectively). When compared with the results obtained in the control group (1.12 ± 0.74 ng/ml), significant decreases in TGF-β1 concentrations after total tumor removal were found in both the benign and malignant brain tumor groups (2.55 ± 2.00 and 8.93 ± 5.73 ng/ml, respectively; p = 0.0001 and p = 0.003, respectively). On the other hand, plasma TGF-β1 levels in the metastatic brain tumor group showed a slight but significant increase (14.7 ± 9.3 ng/ml, p = 0.035) after tumor removal. In a case of low-grade astrocytoma, plasma levels of TGF-β1 were found to be 3.6 and 1.1 ng/ml before and after tumor removal, respectively. However, recurrent tumor was noted in this patient 7 months later, and the levels of TGF-β1 were 26.2 and 8.4 ng/ml before and after the second operation, respectively. The data show that plasma TGF-β1 was elevated in the circulation of patients with brain tumors and that significant decreases in TGF-β1 levels were observed after the removal of benign and malignant tumors. The results also suggest that TGF-β1 may be a useful serologic marker for brain tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.kjms.2011.11.012DOI Listing
June 2012

Potassium-channel openers KMUP-1 and pinacidil prevent subarachnoid hemorrhage-induced vasospasm by restoring the BKCa-channel activity.

Shock 2012 Aug;38(2):203-12

Department of Neurosurgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.

Alterations in the activity of vascular K channels are commonly associated with abnormalities in cerebral vascular function after subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage-induced vasospasm remains incompletely understood; nevertheless, activation of K channels may be of benefit in relieving spastic constriction. This study was to examine whether the vasodilators KMUP-1 and pinacidil, a KATP-channel opener, have the ability to prevent SAH-induced vasospasm via the large-conductance Ca-activated K (BKCa) channels in cerebral arteries. Rats were divided into four groups including sham-operated, SAH, KMUP-1 treated, and pinacidil treated. Subarachnoid hemorrhage rats were induced by injecting autologous blood into cisterna magna, and then KMUP-1 or pinacidil (1 mg/kg) was injected intraperitoneally 1 and 24 h after SAH. Behavioral tests were assessed on day 2 after SAH before the rats were killed. Cerebral myocytes were enzymatically isolated from rat basilar arteries and used to monitor BKCa-channel activities. In isolated basilar arteries, KMUP-1-treated and pinacidil-treated rats showed normalized vascular reactivity. In whole-cell recordings, BKCa currents were attenuated in SAH rats compared with sham-operated rats. In inside-out patches, the conductance and voltage sensitivity of single BKCa-channels were unchanged among the four groups. In contrast, SAH rats showed markedly decreased BKCa-channel activity and β1-subunit expression associated Ca sensitivity that was further confirmed by immunofluorescence staining and Western blotting. Subarachnoid hemorrhage-induced deficits in motor function and BKCa-channel inhibition were improved by KMUP-1-treated and pinacidil-treated rats. In addition, SAH appears to modify BKCa-channel calcium sensitivity. KMUP-1 and pinacidil prevent SAH-induced vasospasm at least in part by the restoration of BKCa-channel activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/SHK.0b013e31825b2d82DOI Listing
August 2012

The Chinese Facial Emotion Recognition Database (CFERD): a computer-generated 3-D paradigm to measure the recognition of facial emotional expressions at different intensities.

Psychiatry Res 2012 Dec 12;200(2-3):928-32. Epub 2012 Apr 12.

Department of Psychiatry, Chi Mei Medical Center, Tainan, Taiwan.

The Chinese Facial Emotion Recognition Database (CFERD), a computer-generated three-dimensional (3D) paradigm, was developed to measure the recognition of facial emotional expressions at different intensities. The stimuli consisted of 3D colour photographic images of six basic facial emotional expressions (happiness, sadness, disgust, fear, anger and surprise) and neutral faces of the Chinese. The purpose of the present study is to describe the development and validation of CFERD with nonclinical healthy participants (N=100; 50 men; age ranging between 18 and 50 years), and to generate normative data set. The results showed that the sensitivity index d' [d'=Z(hit rate)-Z(false alarm rate), where function Z(p), p∈[0,1]], for all emotions was 0.94. The emotion was more readily detected in happiness, and less easily detected in surprise and sadness. In general, this study replicated the previous findings on the recognition accuracy of emotional expression with the Westerner faces. However, our paradigm extends the previous work by including a wider sensitivity range to differentiate subtle perception of emotion intensities. The CFERD will be a useful tool for emotion recognition assessment in affective neurosciences research, especially for the Chinese and cross-cultural studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.psychres.2012.03.038DOI Listing
December 2012

GSK3β regulates Bcl2L12 and Bcl2L12A anti-apoptosis signaling in glioblastoma and is inhibited by LiCl.

Cell Cycle 2012 Feb 1;11(3):532-42. Epub 2012 Feb 1.

Department of Biochemistry, Faculty of Medicine, College of Medicine, Graduate Institute of Medicine, Kaohsiung Medical University, and Department of Anesthesiology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.

BCL2L12 has been reported to be involved in post-mitochondrial apoptotic events in glioblastoma, but the role of BCL2L12A, a splicing variant of BCL2L12, remains unknown. In this study, we showed that BCL2L12 and BCL2L12A were overexpressed in glioblastoma multiforme (GBM). Large-scale yeast two-hybrid screening showed that BCL2L12 was a GSK3b binding partner in a testis cDNA library. Our data demonstrated that GSK3b interacts with BCL2L12 but not BCL2L12A, whose C terminus lacks a binding region. We found that a BCL2L12(153-191) fragment located outside of the C-terminal BH2 motif is responsible for GSK3b binding. In contrast, no interaction was detected between BCL2L12A and GSK3b. In vitro kinase and l-phosphatase assays showed that GSK3b phosphorylates BCL2L12 at S156, while this site is absent on BCL2L12A. Moreover, our data also showed that the BCL2L12(153-191) fragment directly interrupted GSK3bmediated Tau phosphorylation in a dose-dependent manner. Ectopic expression of GFP-fused BCL2L12 or BCL2L12A in U87MG cells leads to repression of apoptotic markers and protects against staurosporine (STS) insults, indicating an antiapoptotic role for both BCL2L12 and BCL2L12A. In contrast, no anti-apoptotic ability was seen in BCL2L12(S156A). When BCL2L12-expressing U87MG cells were co-administrated with STS and LiCl, cells underwent apoptosis. This effect could be reversed by LiCl. In short, we established a model to demonstrate that GSK3b interacts with and phosphorylates BCL2L12 and might also affect BCL2L12A to modulate the apoptosis signaling pathway in glioblastoma. These findings suggest that LiCl may be a prospective therapeutic agent against GBM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4161/cc.11.3.19051DOI Listing
February 2012

Immune and inflammatory gene signature in rat cerebrum in subarachnoid hemorrhage with microarray analysis.

Mol Med Rep 2012 Jan 3;5(1):118-25. Epub 2011 Oct 3.

Department of Medical Laboratory Science and Biotechnology, Fooyin University, Kaohsiung, Taiwan, ROC.

Cerebral vasospasm following subarachnoid hemorrhage (SAH) has been studied in terms of a contraction of the major cerebral arteries, but the effect of cerebrum tissue in SAH is not yet well understood. To gain insight into the biology of SAH-expressing cerebrum, we employed oligonucleotide microarrays to characterize the gene expression profiles of cerebrum tissue at the early stage of SAH. Functional gene expression in the cerebrum was analyzed 2 h following stage 1-hemorrhage in Sprague-Dawley rats. mRNA was investigated by performing microarray and quantitative real-time PCR analyses, and protein expression was determined by Western blot analysis. In this study, 18 upregulated and 18 downregulated genes displayed at least a 1.5-fold change. Five genes were verified by real-time PCR, including three upregulated genes [prostaglandin E synthase (PGES), CD14 antigen, and tissue inhibitor of metalloproteinase 1 (TIMP1)] as well as two downregulated genes [KRAB-zinc finger protein-2 (KZF-2) and γ-aminobutyric acid B receptor 1 (GABA B receptor)]. Notably, there were functional implications for the three upregulated genes involved in the inflammatory SAH process. However, the mechanisms leading to decreased KZF-2 and GABA B receptor expression in SAH have never been characterized. We conclude that oligonucleotide microarrays have the potential for use as a method to identify candidate genes associated with SAH and to provide novel investigational targets, including genes involved in the immune and inflammatory response. Furthermore, understanding the regulation of MMP9/TIMP1 during the early stages of SAH may elucidate the pathophysiological mechanisms in SAH rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/mmr.2011.614DOI Listing
January 2012

Magnesium lithospermate B alleviates the production of endothelin-1 through an NO-dependent mechanism and reduces experimental vasospasm in rats.

Acta Neurochir (Wien) 2011 Nov 11;153(11):2211-7. Epub 2011 Aug 11.

Department of Surgery, College of Medicine, Kaohsiung Medical University, Taiwan, Republic of China.

Objective: Magnesium lithospermate B (MLB), a working extract from Salvia miltiorrhiza, was effective against coronary artery disease, ischemic stroke, and chronic renal disease. This study examined the effect of MLB on endothelin-1/endothelial nitric oxide synthase (eNOS) in a subarachnoid hemorrhage (SAH) animal model.

Methods: A rodent double-hemorrhage model was employed. Animals were randomly assigned to five groups (sham, SAH only, vehicle, 10 mg/kg/day MLB treatment, and pretreatment groups). A radiolabeled NOS Assay Kit was used to detect eNOS. Serum and cerebrospinal fluid sampling for ET-1 (ELISA) was measured. The basilar arteries (BAs) were garnered and sliced, and their cross-sectional areas were determined. In addition, NOS inhibitor nitro-arginine methyl ester (L-NAME) was employed in the SAH+ MLB treatment groups.

Results: Significant vasoconstriction was perceived in the SAH group (lumen patency: 44.6%, p < 0.01), but not in the MLB group (lumen patency: 89.3%). The ET-1 level was reduced in the MLP plus SAH group (34%, p < 0.01) when compared with the SAH groups (SAH only and vehicle). MLB dose-dependently increased the level of eNOS when compared with the vehicle plus SAH group. However, the administration of L-NAME reversed the expression of eNOS and vasoconstriction (lumen patency: 56.2%) in the MLB group.

Conclusion: The enhanced expression of eNOS and decreased ET-1 levels in the MLB groups may reflect its anti-spastic effect. In the study of NOS, L-NAME reversed MLB's anti-vasospastic effect. This finding lends credence to the hypothesis that MLB modulates ET-1 levels through a NOS-dependent mechanism in the pathogenesis of cerebral vasospasm following SAH.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-011-1082-6DOI Listing
November 2011

Malignant transformation of a desmoplastic infantile ganglioglioma.

Pediatr Neurol 2011 Aug;45(2):135-7

Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.

We describe a rare case of desmoplastic infantile ganglioglioma that appears to have transformed into a glioblastoma multiforme tumor in a 5-year-old girl. The patient was initially treated with total removal of the tumor, without subsequent radiation therapy or chemotherapy. She was in good health for 3 years, but manifested a sudden onset of seizures, followed by severe headache, vomiting, and left-sided weakness. Cranial magnetic resonance imaging revealed a large mass with rim enhancement at the previously operated site. The mass was completely removed, and the pathology report revealed glioblastoma multiforme. Postoperative chemotherapy and radiation treatment were administered. She has been followed for 11 years, and is alive without recurrence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.pediatrneurol.2011.04.001DOI Listing
August 2011

Autoimmunity against hNinein, a human centrosomal protein, in patients with rheumatoid arthritis and systemic lupus erythematosus.

Mol Med Rep 2011 Sep-Oct;4(5):825-30. Epub 2011 Jun 7.

Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, R.O.C.

Centrosomes are organelles involved in the organization of the mitotic spindle and may also be the targets of autoantibodies in autoimmune diseases. Human Ninein (hNinein) is a centrosomal autoantigen that is identified by autoimmune patient sera. However, none of the hNinein-specific fragments recognized by the autoantibodies in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) sera have been thoroughly characterized. We thus attempted to identify the fine specificity within the hNinein protein. In this study, four recombinant proteins in two isoforms of hNinein were used as autoantigens along with immunoassays as a molecular tool to investigate the prevalence of hNinein autoreactivity and its specificity in 22 RA and 32 SLE autoimmune disease sera. The data indicated a 50% higher prevalence of isoform 4 hNinein N-terminal autoantibodies in RA sera, whereas 22% of SLE patients were autoreactive to the N-terminal of isoform 4 hNinein compared to only a small percentage of autoreactive normal sera (5%). These results showed that autoepitopes on autoantigen hNinein are restricted to the N-terminal region and that a more significant proportion of RA patients exhibited centrosome reactivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/mmr.2011.505DOI Listing
November 2011

A retrospective survey of patients with malignant gliomas treated in the neuro-oncological care system under the Universal National Health Insurance program in Taiwan.

J Clin Neurosci 2011 Jun 19;18(6):784-8. Epub 2011 Apr 19.

Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou & Chang Gung University, Taoyuan, Taiwan.

In 1995 a government-supported Universal National Health care system was implemented in Taiwan, which in 2008 was available to 98% of the population. This system offers affordable, rapid medical attention. A multi-center retrospective study was conducted to assess the prognosis of malignant glioma patients under this system. In 2005 and 2006, patients at 14 independent neuro-oncology centers with newly diagnosed malignant glioma were enrolled. The patient profile, pathology, treatment modalities, and prognosis were collected by questionnaire at each center. The Taiwan Neuro-Oncology Society was responsible for the data analysis. The overall median survival period, 1-year survival rate, and 2-year survival rate for patients with World Health Organization grade III glioma were 33.8 months, 81.4%, and 58.2%, respectively, and 15 months, 57.3%, and 33.9% in patients with grade IV glioma. The median survival period, 1-year survival rate, and 2-year-survival rate in patients receiving temozolomide adjuvant therapy was 36 months, 84.2%, and 61.8%, respectively, for patients with grade III glioma and 19.8 months, 73.1%, and 43.7%, for patients with grade IV glioma. The universal health care system in Taiwan offers a comparable prognosis with an affordable premium relative to other large series in developed countries.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jocn.2010.10.016DOI Listing
June 2011

Eosinophilic granuloma of the occipital bone in an adult: a case report.

Kaohsiung J Med Sci 2011 Feb 12;27(2):76-9. Epub 2011 Feb 12.

Division of Neurosurgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.

Eosinophilic granuloma (EG) refers to the most common and benign form of the disorder known as Langerhans' cell histiocytosis. The disease is typically found in children and adolescents and rarely affects adults. We present a case of EG in the occipital bone in a 36-year-old man, who visited our hospital with the chief complaint of left occipital palpable tumor mass with local tenderness and pain for one month. An X-ray of the skull revealed a rounded osteolytic lesion. A computed tomography scan revealed a shadow of soft tissues in the left occipital site involving the entire thickness of the calvaria, which was indicative of marked destruction of the bone. The soft mass was successfully removed. The margins of the skull lesion were excised, and cranioplasty was performed simultaneously with bone cement. A definitive diagnosis of EG was made by histopathology and immunohistochemical detection of S-100 antigen in the tissue samples. With respect to management, we believe surgery is the best option for most accessible cranial lesions of EG. A cranioplasty with bone cement or autologous bone can be performed in the same session to repair the cranial defect.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.kjms.2010.05.004DOI Listing
February 2011

The effect on patient loyalty of service quality, patient visit experience and perceived switching costs: lessons from one Taiwan university hospital.

Health Serv Manage Res 2011 Feb;24(1):29-36

Department of Medical Information Management, Kaohsiung Medical University, Taiwan.

The reimbursement system changed from fee-for-service to fixed prospective payments in Taiwan, the effect on the physician-patient's relationship is worth being studied. We examined the relationship between patient visit experience, cost perceptions and the two important aspects of quality of care, curing and interpersonal performance, and patients' loyalty to the hospital physicians. A total of 404 patients from an acute care hospital in Taiwan, Kaohsiung Medical University Hospital (KMUH), were investigated using a self-administered mailing survey. All measures including patient loyalty (PL), curing service quality (CSQ), interpersonal service quality (ISQ), visit experience (VE) and perceived switching costs (PSC), were adapted and modified from existing scales. Our results showed that the physician's CSQ and ISQ positively affected patients' loyalty to KMUH. The interaction between the main effects of service quality, patients' VE and three types of switching visit costs, yielded additional insights into the importance of service quality for patient retention. The CSQ of physicians becomes a more important determinant of loyalty than ISQ as patients' VE increases. The importance of CSQ and ISQ increases in relation to PL as the perceived procedural and relational costs of changing care providers increases. Neither CSQ nor ISQ has a reduced relationship with PL as the perceived financial costs of switching hospitals increase. Our study indicates that the impact of CSQ and ISQ on loyalty varies according to the perceived visit costs of changing hospitals and the patients' VE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1258/hsmr.2010.010011DOI Listing
February 2011

Systemic pro-opiomelanocortin expression induces melanogenic differentiation and inhibits tumor angiogenesis in established mouse melanoma.

Hum Gene Ther 2011 Mar 7;22(3):325-35. Epub 2011 Feb 7.

Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.

Malignant melanoma is one of the leading causes of cancer mortality worldwide, underlining the need for effective novel therapies. In this study, the therapeutic efficacy and mechanism of systemic pro-opiomelanocortin (POMC) therapy were evaluated in mice bearing established melanoma. Injection of adenovirus encoding POMC (Ad-POMC) led to hepatic POMC overexpression and elevated adrenocorticotropin (ACTH) levels in the circulation. Systemic POMC therapy significantly attenuated the growth of established melanoma and prolonged the survival of tumor-bearing mice. Histological analysis revealed that systemic POMC therapy induced melanogenic differentiation while reducing melanoma growth. In addition, POMC therapy also elicited a significant reduction in the neovascular network of melanoma. Last, we demonstrated that POMC-derived peptides, including ACTH, α-melanocyte-stimulating hormone (α-MSH), and β-MSH, are involved in POMC-mediated melanogenic differentiation and angiogenesis inhibition. In summary, systemic POMC therapy suppresses melanoma growth via induction of melanogenic differentiation and angiogenesis blockade, thereby demonstrating its potential as a novel treatment modality for melanoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/hum.2010.090DOI Listing
March 2011

Differential expression of hedgehog signaling components and Snail/E-cadherin in human brain tumors.

Oncol Rep 2010 Nov;24(5):1225-32

Department of Biochemistry, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.

The hedgehog (Hh) transcription factor Gli induces transformation of epithelial cells via induction of Snail, a repressor of E-cadherin. Epithelial-mesenchymal transition is also a determinant of the progression of tumorigenesis, following down-regulation of E-cadherin. However, the role of Hh signaling components and Snail/E-cadherin in brain tumors is not yet fully understood. We analyzed the expression of Hh signaling components and Snail/E-cadherin in 69 brain tumors by reverse transcription-polymerase chain reaction (RT-PCR). The data showed that overexpression of Smo (35/69), Ptch (50/69), Gli1 (56/69), Gli2 (29/69) and N-myc (39/69) might contribute to brain tumorigenesis. Our results also indicated that Snail and E-cadherin showed opposing expression in malignant tumors (high grade astrocytoma and metastasis). Snail and E-cadherin showed less correlation in benign brain tumors. We further investigated mutations of Gli2 and Snail by RT-PCR and direct sequencing. No mutation was observed on Gli2 but several sporadic mutations on Snail were found, including S96G, S111L, S111L/S119Y and one nonsense mutation at codon 158 (Y158*). An in vitro E-cadherin promoter assay showed that S96G, S111L, S111L/S119Y Snail mutants were decreased by 15, 25 and 50%, respectively, whereas Y158* was increased by 40% compared to wild-type. Furthermore, our data showed that wild-type Snail and S96G, S111L, S111L/S119Y translocated to the nucleus, while the Y158* mutant failed to translocate to the nucleus. Taken together, our results demonstrate that Hh signaling components, the expression and mutations of Snail and the expression of E-cadherin may play an important role in human brain tumorigenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/or_00000976DOI Listing
November 2010

Functional characterization of AIBp, a novel Aurora-A binding protein in centrosome structure and spindle formation.

Int J Oncol 2010 Aug;37(2):429-36

Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, ROC.

Aurora-A is involved in chromosome alignment, centrosome maturation, mitotic spindle assembly and regards to an oncogene. Aurora-A is also known to bind to several other proteins affecting its up-regulation or down-regulation and localization. However, how these different binding signals work together to regulate Aurora-A is not properly known. To explore more Aurora-A interacting proteins, the low-copy yeast two-hybrid screening using Aurora-A as bait protein was performed. One novel gene, AIBp, was demonstrated to associate with Aurora-A by the yeast two-hybrid method and in vitro GST pull-down assay. Molecular characterization showed that AIBp possessed a binding site at the C-terminal with Aurora-A (kinase domain). Interestingly, AIBp also interacts with hNinein at the N-terminal, which overlaps with a previously reported hNinein and GSK3beta binding site. Using a kinase assay, AIBp interacts with the Aurora-A kinase domain functions as a positive regulator, whereas AIBp binding to hNinein appears to block the phosphorylation of hNinein by both Aurora-A and GSK3beta. siRNA-mediated elimination of AIBp from HeLa cells, results in a doughnut-like shape, asymmetrical spindle pole and multiple spindle pole formation. We also demonstrated that both AIBp and Aurora-A are co-overexpressed in various brain tumors. These studies demonstrate that AIBp may not only be required for the dynamic movement of Aurora-A at the centrosomes and spindle apparatus during the cell cycle, but may also be important during brain tumorigenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ijo_00000691DOI Listing
August 2010

6-Mercaptopurine exerts an immunomodulatory and neuroprotective effect on permanent focal cerebral occlusion in rats.

Acta Neurochir (Wien) 2010 Aug 13;152(8):1383-90; discussion 1390. Epub 2010 May 13.

Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

Background: A bursting cascade of inflammation imposes progressive neurological deterioration after experimental stroke has been demonstrated. In our study, 6-mercaptopurine (6-mp) has been successful in alleviating cerebral infarct in a rodent permanent middle cerebral artery occlusion (pMCAO) model. The present study was aimed to examine the effect of 6-mp on cytokine levels in experimental stroke.

Methods: The rodent pMCAO model was employed. A dose of 2 mg/kg 6-mp or vehicle (0.1 mol/L PBS) was administered intraperitoneally 30 min after the induction of pMCAO. Neurological score, serum, and cerebrospinal fluid (CSF) cytokines such as IL-1beta, IL-6, and TNF-alpha and infarct volume were determined 48 h after pMCAO.

Results: Cerebral infarction volume was significantly decreased in animals treated with 6-mp (74.3%, p < 0.01), and the ratio of tissue edema was also decreased in 6-mp-treated groups (71%). Animals receiving 6-mp thus showed a significant decrease in IL-1 and TNF-alpha (18/43% and 48/64% in CSF/serum, respectively) when compared with the pMCAO groups (p < 0.01).

Conclusion: This study demonstrates that 6-mp interposes the production of IL-1 and TNF-alpha in CSF and serum, attenuates ischemic brain injury, and thus alleviates neurological deficits in the pMCAO animals. These findings also offer first evidence that 6-mp may attenuate TNF-alpha-related neuron apoptosis and also support the notion that 6-mp and other anti-inflammatory agents could potentially have therapeutic uses in cases of cerebral infarct.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-010-0608-7DOI Listing
August 2010

Atorvastatin preconditioning attenuates the production of endothelin-1 and prevents experimental vasospasm in rats.

Acta Neurochir (Wien) 2010 Aug 4;152(8):1399-406; discussion 1405-6. Epub 2010 May 4.

College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

Objective: Induced endothelin-1 (ET-1) production and decreased nitric oxide synthase (NOS) bioavailability have been found in aneurysmal subarachnoid hemorrhage (SAH). Atorvastatin is recognized to have pleiotropic effects including increasing NOS bioavailability as well as reducing inflammation and oxidative damage other than reducing dyslipidemia. This study is of interest to examine the effect of atorvastatin on ET-1/endothelial nitric oxide synthase (eNOS) in experimental SAH.

Methods: A rodent double-hemorrhage SAH model was employed. Animals were randomly assigned as sham-operated, SAH, vehicle plus SAH, 5 mg/day atorvastatin treatment plus SAH and 5 mg/day atorvastatin precondition plus SAH groups. Administration with atorvastatin (5 mg/day) was initiated 1 week before (precondition) and 24 hr later (treatment). Cerebrospinal fluid samples were collected at 72 hr after second SAH. ET-1 (ELISA) was measured. The basilar arteries (BAs) were harvested and sliced, and their cross-sectional areas were measured. Radiolabeled NOS assay kit was used to detect eNOS.

Results: Morphologically, convoluted internal elastic lamina, distorted endothelial cells and myonecrosis of the smooth muscle were predominantly observed in the BA of SAH and vehicle-treated SAH groups, which was not detected in the atorvastatin-preconditioned SAH group or the healthy controls. Significant vasospasm was noted in the vehicle group (lumen potency 64.5%, compared with the sham group, p
Conclusion: This study offers first evidence that atorvastatin in the preconditioning status reduces the level of ET-1, which corresponds to its antivasospastic effect in the condition of chronic vasospasm. Although there is increased expression of NOS in both atorvastatin precondition and reversal groups, BA's lumen potency is significantly increased in the atorvastatin precondition group when compared with the SAH group (p < 0.01).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-010-0652-3DOI Listing
August 2010

6-Mercaptopurine attenuates adhesive molecules in experimental vasospasm.

Acta Neurochir (Wien) 2010 May 2;152(5):861-7. Epub 2010 Mar 2.

Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China.

Objective: Adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin, are important inflammatory mediators which are elevated in the serum of patients following aneurysmal subarachnoid hemorrhage (SAH). The authors previously found that 6-mercaptopurine (6-mp) was effective in preventing and reversing arterial narrowing in a rodent SAH model. The present study was to examine whether levels of adhesion molecules were altered after treatment with 6-mp in this animal model.

Materials And Methods: Animals were each injected with autologous blood into the cisterna magna, and intraperitoneal treatment with 6-mp (2 mg/kg) was initiated 1 h before (prevention) or later (treatment). The compound was subsequently administered at 24 and 48 h post-SAH. Blood samples were collected at 72 h post-SAH to measure ICAM-1, VCAM-1, and E-selectin levels. The basilar arteries were harvested and sliced, and their cross-sectional areas were measured. Morphologically, convolution of the internal elastic lamina, distorted endothelial wall, and myonecrosis of the smooth muscle were prominently observed in the SAH only and vehicle-treated SAH groups, but not in the 6-mp-treated SAH group or in healthy controls. No significant differences were found in the levels of VCAM-1 among all groups. However, the levels of E-selectin were increased in all animals subjected to SAH (SAH only and SAH plus vehicle groups) compared with healthy controls (no SAH), but not in the 6-mp group (SAH plus 6-mp treatment and preventive treatment with 6-mp).Likewise, the levels of ICAM-1 in the SAH only and SAH plus vehicle groups were significantly elevated (p < 0.001), and pretreatment and treatment with 6-mp reduced ICAM-1 to control levels.

Conclusion: These results show that ICAM-1 and E-selectin may play a role in mediating SAH-induced vasospasm and that a reduction of both adhesive molecules after SAH may partly contribute to the antispastic effect of 6-mp.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-010-0602-0DOI Listing
May 2010

Involvement of the residues of GSKIP, AxinGID, and FRATtide in their binding with GSK3beta to unravel a novel C-terminal scaffold-binding region.

Mol Cell Biochem 2010 Jun 31;339(1-2):23-33. Epub 2009 Dec 31.

Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, ROC.

The specificity and regulation of GSK3beta are thought to involve in the docking interactions at core kinase domain because of the particular amino acid residues. Recent X-ray diffraction studies illuminated the relative binding residues on AxinGID and FRATtide for GSK3beta docking and appeared that GSK3beta Val267Gly (V267G) and Tyr288Phe (Y288F) could distinguish the direct interaction between AxinGID and FRATtide. In order to explore the mode that involved the binding of GSKIP to GSK3beta and compare it with that of AxinGID and FRATtide, we pinpointed the binding sites of GSKIP to GSK3beta through the single-point mutation of four corresponding sites within GSK3beta (residues 260-300) as scaffold-binding region I (designated SBR-I(260-300)). Our data showed that these three binding proteins shared similar binding sites on GSK3beta. We also found that the binding of GSK3beta V267G mutant to GSKIP and AxinGID, but not that of Y288F mutant (effect on FRATtide), was affected. Further, based on the simulation data, the electron-density map of GSKIPtide bore closer similarity to the map AxinGID than to that of FRATtide. Interestingly, many C-terminal helix region point-mutants of GSK3beta L359P, F362A, E366K, and L367P were able to eliminate the binding with FRATtide, but not AxinGID or GSKIP. In addition, CABYR exhibited a unique mode in binding to C-terminal helix region of GSK3beta. Taken together, our data revealed that in addition to the core kinase domain, SBR-I(260-300), another novel C-terminus helix region, designated SBR-II(339-383), also appeared to participate in the recognition and specificity of GSK3beta in binding to other specific proteins.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11010-009-0366-0DOI Listing
June 2010

GSKIP, an inhibitor of GSK3beta, mediates the N-cadherin/beta-catenin pool in the differentiation of SH-SY5Y cells.

J Cell Biochem 2009 Dec;108(6):1325-36

Department of Biochemistry, Faculty of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.

Emerging evidence has shown that GSK3beta plays a pivotal role in regulating the specification of axons and dendrites. Our previous study has shown a novel GSK3beta interaction protein (GSKIP) able to negatively regulate GSK3beta in Wnt signaling pathway. To further characterize how GSKIP functions in neurons, human neuroblastoma SH-SY5Y cells treated with retinoic acid (RA) to differentiate to neuron-like cells was used as a model. Overexpression of GSKIP prevents neurite outgrowth in SH-SY5Y cells. GSKIP may affect GSK3beta activity on neurite outgrowth by inhibiting the specific phosphorylation of tau (ser396). GSKIP also increases beta-catenin in the nucleus and raises the level of cyclin D1 to promote cell-cycle progression in SH-SY5Y cells. Additionally, overexpression of GSKIP downregulates N-cadherin expression, resulting in decreased recruitment of beta-catenin. Moreover, depletion of beta-catenin by small interfering RNA, neurite outgrowth is blocked in SH-SY5Y cells. Altogether, we propose a model to show that GSKIP regulates the functional interplay of the GSK3beta/beta-catenin, beta-catenin/cyclin D1, and beta-catenin/N-cadherin pool during RA signaling in SH-SY5Y cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcb.22362DOI Listing
December 2009

CTNNB1 (beta-catenin) mutation is rare in brain tumours but involved as a sporadic event in a brain metastasis.

Acta Neurochir (Wien) 2009 Sep 7;151(9):1107-11. Epub 2009 Jul 7.

Department of Medical Technology, Fooyin University, Kaohsiung, Taiwan, People's Republic of China.

Background: The Wnt signaling pathway has been implicated in colon and other cancers. Nevertheless, few or no mutations of CTNNB1 (beta-catenin) have so far been described in brain cancer. We therefore examined the prevalence of constitutive activation of the Wnt signaling pathway in brain cancer specimens as well as cancer cell lines.

Method: We used polymerase chain reaction PCR and direct sequencing methods to investigate whether mutations in the CTNNB1 phosphorylation sites S33, S37, S41 and T45 were present in 68 brain tumours, including meningioma, astrocytoma, pituitary adenoma, neuroblastoma, metastasis to the brain, and cell lines.

Findings: CTNNB1 gene mutations were not found in either the original brain tumour specimens or the cell lines. However, a missense mutation of CTNNB1 was identified at residue 33, TCT (Ser) --> TGT (Cys) in a patient with lung metastasis to brain. In addition, in vitro functional assay showed that the S33C mutant of beta-catenin did affect transcriptional activity in a TCF-4-luciferase reporter construct.

Conclusions: These results indicate that the mutation of exon 3 of the CTNNB1 gene in brain tumours may be a rare event and yet may be required for a small subset of human metastatic brain tumours.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-009-0242-4DOI Listing
September 2009