Strategy and long-term outcomes of endovascular treatment for Budd-Chiari syndrome complicated by inferior vena caval thrombosis

OBJECTIVES

The aim of this study was to evaluate the strategy and long-term outcomes of endovascular treatment of Budd-Chiari syndrome (BCS) complicated by inferior vena cava (IVC) thrombosis.

METHODS

The treatment strategy and outcomes of BCS complicated by IVC thrombosis were retrospectively evaluated in a single-center study. The treatment was aimed at the IVC thrombus, not hepatic vein occlusion. All 133 patients with BCS complicated by IVC thrombosis from February 2003 to March 2013 underwent endovascular treatment. For the fresh thrombus group (n=75) recanalization was performed after transcatheter thrombolysis with urokinase. For the mixed thrombus group (n=19) a small balloon pre-dilation of the IVC was performed first, followed by transcatheter thrombolysis using urokinase and a large balloon dilation of the IVC. For the old thrombus group (n=39) a large balloon dilation or/and stent placement was performed directly. Pre- and post-treatment follow-ups were recorded.

RESULTS

The endovascular treatment was successful in 131 out of 133 patients (98.5%). Thirty seven patients had synchronous hepatic vein occlusion. The incidence of serious complications was 4.5% (6/133). Symptomatic pulmonary embolism occurred in three cases, cerebral hemorrhage in two, and cardiac tamponade in one. The cumulative 1-, 5-, and 10-year primary patency rate was 96.3%, 84.0%, and 64.6%, respectively. The cumulative 1-, 5-, and 10-year secondary patency rate was 99.0%, 96.1% and 91.3%, respectively. Segmental occlusion of the IVC and duration of anticoagulant therapy less than 6 months were independent risk factors for reocclusion.

CONCLUSIONS

For patients with BCS complicated by IVC thrombosis, an individualized treatment strategy based on the property of the thrombus can result in excellent long-term patency.

Genetic affinities of central China populations

Hunan locates in the south-central part of China, to the south of the middle reaches of the Yangtze River and south of Lake Dongting. According to the historical records, the peopling of Hunan by modern human ancestors can ascend to 40 thousand years ago. Thus, to trace the ancient maternal components can offer further insight into the origin of south-central China. In this study, we investigated the mitochondrial DNA of 114 individuals from Hunan Province (including 34 Han, 40 Tujia and 40 Miao). Hypervariable regions I and II of the mtDNA control region were sequenced, and the relative diagnostic variations in coding region according to the updated worldwide phylogeny tree were selected and typed by restriction fragment length polymorphism analysis or direct sequencing. All individuals were classified into specific (sub)haplogroups. By comparison with the surrounding populations, southern China-prevalent haplogroups were detected with relative higher frequency in the Tujia and Miao ethnic populations, such as haplogroup B, with more than 20%, lacking in the Han population, which illustrated its southern origin characters. In addition, we also detected northern of East Asia prevalent haplogroups with a relative higher frequency in Tujia populations than in the Miao and Yao ethnic groups, implying a gene flow from Han populations. However, the language-clustering tendency was supported by our principal component analysis and further genetic estimation results. Han and ethnic groups in central China exhibited specific ancestors related to their closer language affinity, although there was extensively genetic admixture between Han and ethnic groups.

An elevated plasma level of visfatin increases the risk of myocardial infarction

Visfatin, an adipocytokine involved in metabolic and immune disorders, plays an important role in the etiology of cardiovascular disease. Recent evidence has shown that an elevated plasma level of visfatin may increase the risk of myocardial infarction (MI), but individual published studies have shown inconclusive results. This study aimed to obtain a more precise estimate of the association between the plasma visfatin level and MI risk through a detailed meta-analysis of studies published in peer-reviewed journals. A literature search of articles published before May 1, 2013 was performed on the PubMed, Embase, Web of Science, and China BioMedicine databases. Crude standardized mean differences (SMDs) with 95% confidence intervals (CI) were calculated. Eleven case-control studies comprising 362 MI patients and 322 healthy controls were included. The meta-analysis revealed that an elevated plasma level of visfatin was associated with an increased risk of MI (SMD = 3.82, 95%CI = 2.67-4.98, P < 0.001). Further stratification based on the source of the controls showed that an elevated plasma level of visfatin was significantly associated with increased risk of MI in both hospital-based and population-based studies (SMD = 4.12, 95%CI = 2.23-6.01, P < 0.001 and SMD = 3.65, 95%CI = 2.67- 4.98, P < 0.001, respectively). No publication bias was evident in this meta-analysis. In conclusion, the current meta-analysis indicates that an elevated plasma level of visfatin increases the risk of MI. Therefore, plasma visfatin may be a promising biomarker for the diagnosis of MI.

Old versus new FIGO staging systems in predicting overall survival in patients with uterine leiomyosarcoma: a study of 86 cases

OBJECTIVES

Uterine leiomyosarcoma (uLMS) was staged using the FIGO system for endometrial cancers. The new FIGO system takes into consideration tumor size disregarding myometrial and cervical involvement. We aimed to compare the two systems and see which more accurately predicts overall survival (OS).

METHODS

86 patients with uLMS (1984-2010) were retrospectively staged using both FIGO systems. Mean OS rates were estimated using the Kaplan-Meier method.

RESULTS

More patients had stage-I disease by the new FIGO system (42 versus 33). Five versus 18 and 27 versus 5 had old and new stage-II and III diseases respectively. Five and 4 patients with old stage II and III uLMS respectively were downstaged to stage I while 18 with old stage III were downstaged to stage II. Median follow-up was 23.5 months with a median OS of 114 (95% CI, 61-166) months. Although patients with stage I tumors had a higher mean OS rate compared to those with higher stage disease by either system, patients with old stage II-IV disease showed similar mean OS rates, with stage III-IV patients having a slightly better mean OS and a similar trend was observed with the new system. Patients with new FIGO stage III had a higher mean OS rate than those with stage II or IV disease (37.6 versus 28.1 and 34.3 months). Nonetheless, no statistical significant differences were seen in OS according to stage using either system (p=0.786 and p=0.400 respectively).

CONCLUSION

Neither FIGO staging system is ideal in classifying patients into four clinically significant stages.

R26R-GR: a Cre-activable dual fluorescent protein reporter mouse

Green fluorescent protein (GFP) and its derivatives are the most widely used molecular reporters for live cell imagining. The development of organelle-specific fusion fluorescent proteins improves the labeling resolution to a higher level. Here we generate a R26 dual fluorescent protein reporter mouse, activated by Cre-mediated DNA recombination, labeling target cells with a chromatin-specific enhanced green fluorescence protein (EGFP) and a plasma membrane-anchored monomeric cherry fluorescent protein (mCherry). This dual labeling allows the visualization of mitotic events, cell shapes and intracellular vesicle behaviors. We expect this reporter mouse to have a wide application in developmental biology studies, transplantation experiments as well as cancer/stem cell lineage tracing.

Thymic stromal lymphopoietin: a promising therapeutic target for allergic diseases

Thymic stromal lymphopoietin (TSLP), an interleukin 7-like cytokine, can trigger dendritic cell (DC)-mediated T-helper type 2 (Th2) inflammatory responses. Recent evidence demonstrates that cytokines TSLP and OX40 (CD134)/OX40 ligand seem to be important players in the maintenance of Th2 memory pool in the pathogenesis of asthma. Accumulating data reveal that the pathogenic T cells involved in asthma are likely to be inflammatory Th2 cells. TSLP is involved in the development of asthma through crosstalk with nuclear factor NF-ĸB. Progression of skin fibrosis in atopic dermatitis occurs via TSLP/TSLP receptor. TSLP-mediated dermal inflammation aggravates experimental allergic asthma. Also, TSLP polymorphisms are associated with susceptibility to asthma, atopic dermatitis, and eczema herpeticum. These findings suggest a master switch of TSLP in the initiation of allergic and adaptive inflammation through innate pathways at the epithelial cell-DC interface. The TSLP pathway is therefore a promising target for immunotherapy of allergic diseases.

Meta-analysis: the use of carbon dioxide insufflation vs. room air insufflation for gastrointestinal endoscopy

BACKGROUND

Carbon dioxide (CO(2)) insufflation has been proposed as an alternative to air insufflation to distend the lumen in gastrointestinal (GI) endoscopy.

AIM

To perform a systematic review with meta-analysis of randomised controlled trials (RCTs) in which CO(2) insufflation was compared with room air insufflation in GI endoscopy.

METHODS

Electronic and manual searches were combined to search RCTs. After methodological quality assessment and data extraction, the efficacy and safety of CO(2) insufflation were systematically assessed.

RESULTS

Twenty-one RCTs [13 on colonoscopy, four on endoscopic retrograde cholangiopancreatography (ERCP), two on double-balloon enteroscopy (DBE), one on oesophagogastroduodenoscopy, and one on flexible sigmoidoscopy] were identified. For colonoscopy, CO(2) insufflation resulted lower postprocedural pain intensity, and increased the proportion of patient without pain at 1 h (RR: 1.84, 95% CI: 1.37-2.47) and 6 h (RR: 1.28; 95% CI: 1.14-1.44) postprocedure. For ERCP, the pain-releasing effect of CO(2) insufflation was not obvious (SMD: -1.48, 95% CI: -3.56, 0.59). CO(2) insufflation revealed no consistent advantages in the RCTs of DBE, but was shown as safe as air insufflation in oesophagus/stomach endoscopic submucosal dissection in one study. pCO(2) level showed no significant variation during these procedures.

CONCLUSIONS

Compared with air insufflation, CO(2) insufflation during colonoscopy causes lower postprocedural pain and bowel distension without significant pCO(2) variation. More RCTs are needed to assess its advantages in other GI endoscopic procedures.

Extracellular cyclophilin A may be a potential target to protect against myocardial reperfusion injury

Myocardial reperfusion injury is increasingly recognized as an inflammatory process, characterized by neutrophil recruitment and subsequently excessive release of pro-inflammatory factors. Recently, the extracellular cyclophilin A (CypA) has been showed to play an important role in initiation and development of inflammation by chemo trafficking of leukocytes into inflamed tissues, eliciting massive release of pro-inflammatory cytokines, and inducing production of matrix metalloproteinases. Also, the agents targeting CypA have been demonstrated to promise anti-inflammatory effects in the different experimental models of inflammatory diseases including acute lung injury, rheumatoid arthritis, and atherosclerosis. Therefore, we hypothesize that the extracellular CypA may in some way implicated in the pathogenesis of reperfusion-induced inflammatory process, and the specific inhibitors of the extracellular CypA can provide a protection against the myocardial reperfusion injury.

Genetics and molecular mapping of genes for high-temperature resistance to stripe rust in wheat cultivar Xiaoyan 54

Stripe rust, caused by Puccinia striiformis f. sp. tritici, is one of the most widespread and destructive wheat diseases worldwide. Growing resistant cultivars is the preferred means of control of the disease. The winter wheat cultivar Xiaoyan 54 has high-temperature resistance to stripe rust. To identify genes for stripe rust resistance, Xiaoyan 54 was crossed with Mingxian 169, a winter wheat genotype susceptible to all Chinese races of the pathogen. Seedlings and adult plants of the parents and F(1), F(2), F(3) and F(4) progeny were tested with Chinese race CYR32 under controlled greenhouse conditions and in the field. Xiaoyan 54 has two recessive resistance genes, designated as Yrxy1 and Yrxy2, conferring high-temperature resistance. Simple sequence repeat (SSR) primers were used to identify molecular markers flanking Yrxy2 using 181 plants from one segregating F(3) line. A total of nine markers, two of which flanked the locus at genetic distances of 4.0 and 6.4 cM on the long arm of chromosome 2A were identified. Resistance gene analog polymorphism (RGAP) and SSR techniques were used to identify molecular markers linked to Yrxy1. A linkage group of nine RGAP and two SSR markers was constructed for Yrxy1 using 177 plants of another segregating F(3) line. Two RGAP markers were closely linked to the locus with genetic distances of 2.3 and 3.5 cM. Amplification of a set of nulli-tetrasomic Chinese Spring lines with RGAP markers M8 and M9 and the two SSR markers located Yrxy1 on the short arm of chromosome 7A. The SSR markers Xbarc49 and Xwmc422 were 15.8 and 26.1 cM, respectively, from the gene. The closely linked molecular markers should be useful for incorporating the resistance genes into commercial cultivars and combining them with other genes for stripe rust resistance.

Narrow-band imaging with magnifying endoscopy for the screening of esophageal cancer in patients with primary head and neck cancers

BACKGROUND AND STUDY AIM

Although narrow-band imaging (NBI) in endoscopy can improve detection of early-stage esophageal malignancies in patients with head and neck cancers, false-positive results may be obtained in areas with nonspecific inflammatory changes. This study evaluated the feasibility of primary screening with NBI and magnification for the presence of esophageal malignancies in these cancer patients.

PATIENTS AND METHODS

Sixty-nine patients with documented head and neck cancers were enrolled from April 2008 to January 2009. All patients underwent a meticulous endoscopic examination of the esophagus using a conventional white-light system followed by re-examination using the NBI system and final confirmation with NBI plus magnification.

RESULTS

Twenty-one patients (30.4 %) were confirmed to have esophageal neoplasia. Among these 21, 16 (76.2 %) had synchronous lesions, 9 (42.9 %) were asymptomatic, and 10 (47.6 %) had early-stage neoplasia. The incidence of multiple esophageal neoplasia was 57.1 %. NBI was more effective than conventional endoscopy in detecting neoplastic lesions (35 lesions in 21 patients vs. 22 lesions in 18 patients) and was particularly effective in patients with dysplasia (13 lesions in 9 patients vs. 3 lesions in 3 patients). The sensitivity and accuracy of detection were 62.9 % and 64.4 % for conventional endoscopy, 100 % and 86.7 % for NBI alone, and 100 % and 95.6 % for NBI with high magnification, respectively.

CONCLUSIONS

Compared with current approaches, NBI followed by high magnification significantly increases the accuracy of detection of esophageal neoplasia in patients with head and neck cancers. The result warrants conducting prospective randomized controlled study to confirm its efficacy.

Down-Regulation of SHH/BMP4 Signalling in Human Anorectal Malformations

The sonic hedgehog homologue (SHH)/bone morphogenetic protein 4 (BMP4) signalling pathway is involved in the morphogenesis of many organ systems. This study was designed to investigate the expression of SHH/BMP4 pathway components in human anorectal malformations (ARMs) and the relationship between expression of their genes and the occurrence of ARMs. Expression of SHH, GLI family zinc finger 2 (GLI2) and BMP4 mRNA in the posterior wall of the terminal rectum in 40 patients with ARMs (15 high-type and 25 low-type) and 10 normal controls was assessed by reverse transcription-polymerase chain reaction. Levels of SHH, GLI2 and BMP4 proteins were assessed by immunohistochemistry and Western blotting. The expressions of SHH, GLI2 and BMP4 were significantly lower in patients with high-type compared with those with low-type anomalies and controls. Patients with low-type ARMs differed from controls only in the expression of GLI2 mRNA. It is concluded that down-regulation of the SHH/BMP4 signalling pathway may be related to the occurrence of high-type ARMs, but the mechanism responsible for low-type ARMs remains unclear.

Molecular prognosticators of complex karyotype soft tissue sarcoma outcome: a tissue microarray-based study

BACKGROUND

Molecular markers are currently being utilized as sensitive prognosticators of cancer patient outcome. We sought to identify prognostic biomarkers for complex karyotype soft tissue sarcoma (STS).

MATERIALS AND METHODS

A large (n = 205) clinically annotated tissue microarray (TMA) was constructed and immunostained for several tumor-related markers. Staining was scored via an automated Ariol image analysis system; data were statistically analyzed to evaluate the correlation of clinicopathological and molecular variables with overall survival (OS) and local recurrence.

RESULTS

Multivariable analysis identified older age [hazard ratio (HR) 1.62, P < 0.0001], nonextremity location (HR 2.95, P = 0.001), high tumor grade (HR 2.5, P = 0.02), and increased matrix metalloproteinase (MMP) 2 expression (HR 1.74, P = 0.04) as predictors for poor OS. Similarly, older age (HR 1.51, P = 0.008), nonextremity location (HR 4.09, P = 0.001), and increased MMP2 expression (HR 6.28, P = 0.006) were all found to correlate with shorter local recurrence-free interval. High nuclear p53 expression was associated with shorter STS local recurrence-free interval, with a trend toward significance.

CONCLUSIONS

Data presented indicate that a clinically annotated TMA can be utilized to identify STS-related prognostic markers. Specifically, MMP2 and nuclear p53 should be further evaluated for their potential inclusion in complex karyotype STS staging systems.

Multidrug resistant gram-negative bacilli as predominant bacteremic pathogens in liver transplant recipients

BACKGROUND

Bacteremias, which are often caused by gram-negative bacteria, are the most frequently occurring infectious complications after liver transplantation (LT). The aim of this study was to investigate bacteremic incidence, pathogenic spectrum, risk factors for bacteremia due to multidrug resistant (MDR) gram-negative bacilli, and its impact on mortality after LT.

METHODS

A cohort analysis of prospectively recorded data was done in 475 LT recipients, who were divided into 3 categories: cases with gram-negative bacteremia, cases with MDR gram-negative bacteremia, and cases without bacteremia as controls.

RESULTS

In 475 LT recipients, there were 152 (32.0%) patients with gram-negative bacillus bacteremia in the first 6 months after LT. Out of 152 patients, there were 225 bacteremic episodes, which accounted for 69.7% in a total 323 bacteremic episodes. A total of 190 bacteremic episodes were caused by Stenotrophomonas maltophilia, Enterobacteriaceae, Ochrobactrum anthropi, Pseudomonas, and Acinetobacter baumanii, all of which were the most frequent gram-negative isolates in this study, and MDR bacilli constituted 56.3%. The most frequent source was intravascular catheters. There were 70 patients with MDR gram-negative bacillus bacteremia. Independent risk factors for bacteremia due to MDR gram-negative bacillus were as follows: post-LT abdominal infection (P<0.0001, odds ratio [OR] 0.066, 95% confidence interval [CI] 0.019-0.226), post-LT reoperative episodes (P<0.0001, OR 10.505, 95% CI 3.055-36.121), or one or more episodes of acute rejection (P=0.042, OR 4.457, 95% CI 0.988-20.103). In the first 6 months after LT, MDR gram-negative bacillus bacteremia-related mortality was significantly higher than that due to antibiotic-susceptible bacillus (38.6% vs. 14.6%, P<0.001).

CONCLUSION

Post-LT bacteremias caused by MDR gram-negative bacilli are common, and associated with allograft acute rejection, post-LT reoperation, and abdominal infection. The increasing isolates of MDR gram-negative bacilli pose a great challenge for clinical treatment.

Siderophore production by the marine-derived Aureobasidium pullulans and its antimicrobial activity

Over 300 yeast strains isolated from different marine environments were screened for their ability to produce siderophore. Among them, only the yeast strain HN6.2 which was identified to be Aureobasidium pullulans was found to produce high level of the siderophore. Under the optimal conditions, this yeast strain could produce 1.1mg/ml of the siderophore. The crude siderophore produced by the yeast strain HN6.2 was able to inhibit cell growth of Vibrio anguillarum and Vibrio parahaemolyticus, isolated from the diseased marine animals.

Birth of twins after in vitro fertilization with flow-cytometric sorted buffalo (Bubalus bubalis) sperm

Flow-cytometric sorting of mammalian sperm for production of offspring with the desired sex is one of the most important new biotechnologies available for livestock industry. The objectives of this study were: (i) to sort the sperm into X- and Y-enriched populations and (ii) use the sorted sperm for in vitro fertilization (IVF) to produce sex-preselected embryo and offspring. The results revealed that the accuracy of sorted X- and Y-sperm was 94% and 89%, respectively. There was a decrease in blastocyst development rate in IVF with sorted sperm comparing to unsorted sperm, but the percentage of blastocysts on D6-D8 was not statistically different. Transplantation of the presumed X-embryos derived from IVF into a recipient resulted in the birth of female twins. These results indicated the feasibility of sperm sorting by flow cytometry and in vitro production of sex-preselected embryos and offspring in buffalo.

Field emission of GaN-filled carbon nanotubes: high and stable emission current

Field electron emission of GaN-filled carbon nanotubes, grown by microwave plasma enhanced chemical vapor deposition, was investigated. The detailed structural characterization shows that the filled nanotube has a GaN-core/C-shell structure, in which the GaN wire corresponds to a wurtzite structure. The field emission properties of the GaN-filled carbon nanotubes have been achieved with high and stable emission current. It is attributed to the unique cable-like structure, which makes the GaN-core/C-shell composite mechanically solid and chemically stable. This study suggests the GaN-filled carbon nanotube as an ideal candidate for future high-current and high-power field emitter applications.

Direct Synthesis of B−C−N Single-Walled Nanotubes by Bias-Assisted Hot Filament Chemical Vapor Deposition

Direct synthesis of large-scale ternary boron carbonitride single-walled nanotubes (BCN-SWNTs) via a bias-assisted HFCVD process was presented. The BCN-SWNTs were grown over the powdery Fe-Mo/MgO catalyst by using CH4, B2H6, and ethylenediamine vapor as the reactant gases. As high as 16 atom % nitrogen can be incorporated within the nanotube shells, with the boron content in the range of 2-4 atom %. The ternary covalent bonding nature of the BCN-SWNTs was well characterized, and the B, C, and N elemental maps were clearly imaged by energy-filtered transmission electron microscopy.

Protein function classification via support vector machine approach

Support vector machine (SVM) is introduced as a method for the classification of proteins into functionally distinguished classes. Studies are conducted on a number of protein classes including RNA-binding proteins; protein homodimers, proteins responsible for drug absorption, proteins involved in drug distribution and excretion, and drug metabolizing enzymes. Testing accuracy for the classification of these protein classes is found to be in the range of 84-96%. This suggests the usefulness of SVM in the classification of protein functional classes and its potential application in protein function prediction.

Kinetics of acetyl coenzyme A: arylamine N-acetyltransferase from rapid and slow acetylator human benign prostatic hyperplasia tissues

N-acetyltransferase (NAT) activity was determined in 40 human benign prostatic hyperplasia tissues using 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) as substrates. These were then assayed by high performance liquid chromatography for determining the amounts of acetylated AF and PABA and non-acetylated AF and PABA. The activities (mean +/- SD) of AF-NAT from human benign prostatic hyperplasia tissues were divided into rapid (2.06 +/- 0.08 nmol/min per milligram protein), intermediate (1.25 +/- 0.26 nmol/min per milligram protein), and slow (0.58 +/- 0.30 nmol/min per milligram protein) acetylator groups. The activities (mean +/- SD) of PABA-NAT from human benign prostatic hyperplasia tissues were also divided into rapid (2.00 +/- 0.00 nmol/min per milligram protein), intermediate (1.25 +/- 0.18 nmol/min per milligram protein), and slow (0.48 +/- 0.29 nmol/min per milligram protein) acetylator groups. Kinetic constants for arylamine NAT activities were determined for each of these acetylator groups. Apparent differences in Km and Vmax for AF were found. Therefore, there seems to be a polymorphism in NAT activity with two rapid, five intermediate, and 33 slow acetylators among the 40 samples assayed. This is the first demonstration of acetyl CoA-arylamine NAT activity in human benign prostatic hyperplasia tissues.

Expression of nuclear factor-kappa B in hepatocellular carcinoma and its relation with the X protein of hepatitis B virus

AIM

In this study we investigated the relationship of the X protein of HBV and nuclear factor-kappa B (NF-kappa B) and the expression of NF-kappa B in human hepatocellular carcinoma tissues.

METHODS

Immunohistochemistry SP method was used to detect the expression of NF-kappa B and the X protein of HBV in human hepatocellular carcinoma tissues of 52 cases. Gene transfection mediated by lipofectamine was used to transfect the eukaryotic expression vector pCDNA3.1-HBX of HBV x gene into human hepatocellular carcinoma cell line HCC-9204 and NF-kappa B was detected.

RESULTS

NF kappa B was widely expressed in human hepatocellular carcinoma tissues in a total of 52 cases and its expression was related to the X protein of HBV. NF-kappa B was localized both in the cytoplasm and the nuclei of hepatocellular carcinoma cells in 11 cases which were positive for the X protein of HBV while in 41 cases negative for the X protein of HBV, NF-kappa B was only localized in the cytoplasm of hepatocellular carcinoma cells but translocated to the nuclei of hepatocellular carcinoma cells after the eukaryotic expression vector pCDNA3.1-HBX was transfected into HCC-9204 cells.

CONCLUSION

This study strongly suggests that the nuclear factor NF-kappa B is widely expressed in hepatocellular carcinoma tissues in different styles according to the expression of the X protein of HBV. NF-kappa B is abnormally activated in hepatocellular carcinoma, which is probably related to the X protein of HBV. The X protein of HBV can activate NF-kappa B to translocate into nuclei of hepatocellular carcinoma cells.

Mitogen-stimulated TIS21 protein interacts with a protein-kinase-Calpha-binding protein rPICK1

TIS21 is induced transiently by PMA and a number of extracellular stimuli. Yeast two-hybrid screening has identified three TIS21 interacting clones from a rat cDNA library [Lin, Gary, Yang, Clarke and Herschman (1996) J. Biol. Chem 271, 15034-15044]. The amino acid sequence deduced from clone 5A shows 96.9% identity with the murine PICK1, a protein kinase Calpha (PKCalpha)-binding protein postulated to act as an intracellular receptor for PKC. A fusion protein of glutathione S-transferase and rPICK1 associates with the TIS21 translated in vitro, suggesting a direct physical interaction between these two proteins. TIS21 and rPICK1 are co-immunoprecipitated from NIH 3T3 cells overexpressing these two proteins. This indicates that the interaction also occurs in mammalian cells. Deletion of the PDZ domain at the N-terminus of rPICK1 abolishes its interaction with TIS21. A putative carboxylate-binding loop required for PICK1 to bind PKCalpha [Staudinger, Lu and Olson (1997) J. Biol. Chem 272, 32019-32024] is within this deleted region. Our results suggest a potential competition between TIS21 and PKC for binding to PICK1. We show that recombinant TIS21 is phosphorylated by PKC in vitro. The catalytic activity of PKC towards TIS21 is significantly decreased in the presence of rPICK1, whereas phosphorylation of histone by PKC is not affected. rPICK1 seems to modulate the phosphorylation of TIS21 through specific interactions between these two proteins. TIS21 might have a role in PKC-mediated extracellular signal transduction through its interaction with rPICK1.