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1.  Fatty Acid Oxidation Disorders in a Chinese Population in Taiwan 
JIMD Reports  2013;11:165-172.
Background: Fatty acid oxidation (FAO) disorders are a heterogeneous group of inborn errors in the transportation and oxidation of fatty acids. FAO disorders were thought to be very rare in the Chinese population. Newborn screening for FAO disorders beginning in 2002 in Taiwan may have increased the diagnosis of this group of diseases.
Materials and Methods: Till 2012, the National Taiwan University Hospital Newborn Screening Center screened more than 800,000 newborns for FAO disorders. Both patients diagnosed through screening and patients detected after clinical manifestations were included in this study.
Results: A total of 48 patients with FAO disorders were identified during the study period. The disorders included carnitine palmitoyltransferase I deficiency, carnitine acylcarnitine translocase deficiency, carnitine palmitoyltransferase II deficiency, very long-chain acyl-CoA dehydrogenase deficiency, medium-chain acyl-CoA dehydrogenase deficiency, multiple acyl-CoA dehydrogenase deficiency, short-chain defects, and carnitine uptake defect. Thirty-nine patients were diagnosed through newborn screening. Five false-negative newborn screening cases were noted during this period, and four patients who were not screened were diagnosed based on clinical manifestations. The ages of all patients ranged from 6 months to 22.9 years (mean age 6.6 years). Except for one case of postmortem diagnosis, there were no other mortalities.
Conclusions: The combined incidence of FAO disorders estimated by newborn screening in the Chinese population in Taiwan is 1 in 20,271 live births. Newborn screening also increases the awareness of FAO disorders and triggers clinical diagnoses of these diseases.
PMCID: PMC3755561  PMID: 23700290
3.  Genome-wide association analyses identify three new susceptibility loci for primary angle closure glaucoma 
Vithana, Eranga N | Khor, Chiea-Chuen | Qiao, Chunyan | Nongpiur, Monisha E | George, Ronnie | Chen, Li-Jia | Do, Tan | Abu-Amero, Khaled | Huang, Chor Kai | Low, Sancy | Tajudin, Liza-Sharmini A | Perera, Shamira A | Cheng, Ching-Yu | Xu, Liang | Jia, Hongyan | Ho, Ching-Lin | Sim, Kar Seng | Wu, Ren-Yi | Tham, Clement C Y | Chew, Paul T K | Su, Daniel H | Oen, Francis T | Sarangapani, Sripriya | Soumittra, Nagaswamy | Osman, Essam A | Wong, Hon-Tym | Tang, Guangxian | Fan, Sujie | Meng, Hailin | Huong, Dao T L | Wang, Hua | Feng, Bo | Baskaran, Mani | Shantha, Balekudaru | Ramprasad, Vedam L | Kumaramanickavel, Govindasamy | Iyengar, Sudha K | How, Alicia C | Lee, Kelvin Y | Sivakumaran, Theru A | Yong, Victor H K | Ting, Serena M L | Li, Yang | Wang, Ya-Xing | Tay, Wan-Ting | Sim, Xueling | Lavanya, Raghavan | Cornes, Belinda K | Zheng, Ying-Feng | Wong, Tina T | Loon, Seng-Chee | Yong, Vernon K Y | Waseem, Naushin | Yaakub, Azhany | Chia, Kee-Seng | Allingham, R Rand | Hauser, Michael A | Lam, Dennis S C | Hibberd, Martin L | Bhattacharya, Shomi S | Zhang, Mingzhi | Teo, Yik Ying | Tan, Donald T | Jonas, Jost B | Tai, E-Shyong | Saw, Seang-Mei | Hon, Do Nhu | Al-Obeidan, Saleh A | Liu, Jianjun | Chau, Tran Nguyen Bich | Simmons, Cameron P | Bei, Jin-Xin | Zeng, Yi-Xin | Foster, Paul J | Vijaya, Lingam | Wong, Tien-Yin | Pang, Chi-Pui | Wang, Ningli | Aung, Tin
Nature genetics  2012;44(10):1142-1146.
Primary angle closure glaucoma (PACG) is a major cause of blindness worldwide. We conducted a genome-wide association study including 1,854 PACG cases and 9,608 controls across 5 sample collections in Asia. Replication experiments were conducted in 1,917 PACG cases and 8,943 controls collected from a further 6 sample collections. We report significant associations at three new loci: rs11024102 in PLEKHA7 (per-allele odds ratio (OR) = 1.22; P = 5.33 × 10−12), rs3753841 in COL11A1 (per-allele OR = 1.20; P = 9.22 × 10−10) and rs1015213 located between PCMTD1 and ST18 on chromosome 8q (per-allele OR = 1.50; P = 3.29 × 10−9). Our findings, accumulated across these independent worldwide collections, suggest possible mechanisms explaining the pathogenesis of PACG.
PMCID: PMC4333205  PMID: 22922875
4.  Increasing Endocannabinoid Levels in the Ventral Pallidum Restores Aberrant Dopamine Neuron Activity in the Subchronic PCP Rodent Model of Schizophrenia 
Schizophrenia is a debilitating disorder that affects 1% of the US population. While the exogenous administration of cannabinoids such as THC are reported to exacerbate psychosis in schizophrenia patients, augmenting the levels of endogenous cannabinoids has gained attention as a possible alternative therapy to schizophrenia due to clinical and preclinical observations. Thus, patients with schizophrenia demonstrate an inverse relationship between psychotic symptoms and levels of the endocannabinoid anandamide. In addition, increasing endocannabinoid levels (by blockade of enzymatic degradation) has been reported to attenuate social withdrawal in a preclinical model of schizophrenia. Here we examine the effects of increasing endogenous cannabinoids on dopamine neuron activity in the sub-chronic PCP model. Aberrant dopamine system function is thought to underlie the positive symptoms of schizophrenia. Using in vivo extracellular recordings in chloral hydrate anesthetized rats we now demonstrate an increase in dopamine neuron population activity in PCP-treated rats. Interestingly endocannabinoid upregulation, induced by URB-597, was able to normalize this aberrant dopamine neuron activity. Furthermore, we provide evidence that the ventral pallidum is the site where URB-597 acts to restore ventral tegmental area activity. Taken together, we provide preclinical evidence that augmenting endogenous cannabinoids may be an effective therapy for schizophrenia, acting in part to restore ventral pallidal activity.
PMCID: PMC4332795  PMID: 25539511
schizophrenia; cannabinoids; ventral pallidum; hippocampus; phencyclidine
5.  Counterfactual quantum-information transfer without transmitting any physical particles 
Scientific Reports  2015;5:8416.
We demonstrate quantum information can be transferred between two distant participants without any physical particles traveling between them. The key procedure of the counterfactual scheme is to entangle two nonlocal qubits with each other without interaction, so the scheme can also be used to generate nonlocal entanglement counterfactually. We here illustrate the scheme by using flying photon qubits and Rydberg atom qubits assisted by a mesoscopic atomic ensemble. Unlike the typical teleportation, the present scheme can transport an unknown qubit in a nondeterministic manner without prior entanglement sharing or classical communication between the two distant participants.
PMCID: PMC4325340  PMID: 25672936
6.  Association between Family History Risk Categories and Prevalence of Diabetes in Chinese Population 
PLoS ONE  2015;10(2):e0117044.
To investigate the association between different family history risk categories and prevalence of diabetes in the Chinese population.
The family history of diabetes was obtained from each subject, and an oral glucose tolerance test was performed for measuring the fasting and postload glucose and insulin levels based on a national representative cross-sectional survey of 46,239 individuals (age ≥ 20 years) in the 2007–2008 China National Diabetes and Metabolism Disorders Study. The family history risk categories of diabetes were high, moderate, and average (FH2 and FH1: at least two generations and one generation of first-degree relatives with diabetes, respectively; FH0: no first-degree relatives with diabetes).
The age- and gender-adjusted prevalence rates of diabetes were 32.7% (95% confidence interval (CI): 26.4–39.7%) in FH2, 20.1% (95% CI: 18.2–22.1%) in FH1, and 8.4% (95% CI: 7.9–8.9%) in FH0 (P < 0.0001). The calculated homeostatic model assessment-estimated insulin resistance (HOMA-IR), Matsuda insulin sensitivity index (ISI), and insulinogenic index (ΔI30/ΔG30) values showed significant trending changes among the three risk categories, with the most negative effects in FH2. Multivariate logistic regression analysis showed that the odds ratios of having diabetes were 6.16 (95% CI: 4.46–8.50) and 2.86 (95% CI: 2.41–3.39) times higher in FH2 and FH1, respectively, than in FH0 after adjustment for classical risk factors for diabetes.
Family history risk categories of diabetes have a significant, independent, and graded association with the prevalence of this disease in the Chinese population.
PMCID: PMC4321835  PMID: 25664814
7.  Proneural Transcription Factor Atoh1 Drives Highly Efficient Differentiation of Human Pluripotent Stem Cells Into Dopaminergic Neurons 
To fully use human pluripotent stem cells (PSCs) in regenerative medicine, highly efficient differentiation strategies are required to drive induced PSCs into desired lineages and generate functional cell progenies. Current differentiation protocols for deriving dopaminergic neurons from PSCs involve months of stem cell culture procedures and multiple reagents. This study was motivated by a desire for a rapid and highly efficient system to generate human PSC-derived functional dopaminergic neurons.
Human pluripotent stem cells (PSCs) are a promising cell resource for various applications in regenerative medicine. Highly efficient approaches that differentiate human PSCs into functional lineage-specific neurons are critical for modeling neurological disorders and testing potential therapies. Proneural transcription factors are crucial drivers of neuron development and hold promise for driving highly efficient neuronal conversion in PSCs. Here, we study the functions of proneural transcription factor Atoh1 in the neuronal differentiation of PSCs. We show that Atoh1 is induced during the neuronal conversion of PSCs and that ectopic Atoh1 expression is sufficient to drive PSCs into neurons with high efficiency. Atoh1 induction, in combination with cell extrinsic factors, differentiates PSCs into functional dopaminergic (DA) neurons with >80% purity. Atoh1-induced DA neurons recapitulate key biochemical and electrophysiological features of midbrain DA neurons, the degeneration of which is responsible for clinical symptoms in Parkinson’s disease (PD). Atoh1-induced DA neurons provide a reliable disease model for studying PD pathogenesis, such as neurotoxin-induced neurodegeneration in PD. Overall, our results determine the role of Atoh1 in regulating neuronal differentiation and neuron subtype specification of human PSCs. Our Atoh1-mediated differentiation approach will enable large-scale applications of PD patient-derived midbrain DA neurons in mechanistic studies and drug screening for both familial and sporadic PD.
PMCID: PMC4116248  PMID: 24904172
Induced pluripotent stem cells; Embryonic stem cells; Parkinson’s disease; Basic helix-loop-helix transcription factors; Tet-On
8.  Deep Sequencing of HIV-Infected Cells: Insights into Nascent Transcription and Host-Directed Therapy 
Journal of Virology  2014;88(16):8768-8782.
Polyadenylated mature mRNAs are the focus of standard transcriptome analyses. However, the profiling of nascent transcripts, which often include nonpolyadenylated RNAs, can unveil novel insights into transcriptional regulation. Here, we separately sequenced total RNAs (Total RNAseq) and mRNAs (mRNAseq) from the same HIV-1-infected human CD4+ T cells. We found that many nonpolyadenylated RNAs were differentially expressed upon HIV-1 infection, and we identified 8 times more differentially expressed genes at 12 h postinfection by Total RNAseq than by mRNAseq. These expression changes were also evident by concurrent changes in introns and were recapitulated by later mRNA changes, revealing an unexpectedly significant delay between transcriptional initiation and mature mRNA production early after HIV-1 infection. We computationally derived and validated the underlying regulatory programs, and we predicted drugs capable of reversing these HIV-1-induced expression changes followed by experimental confirmation. Our results show that combined total and mRNA transcriptome analysis is essential for fully capturing the early host response to virus infection and provide a framework for identifying candidate drugs for host-directed therapy against HIV/AIDS.
IMPORTANCE In this study, we used mass sequencing to identify genes differentially expressed in CD4+ T cells during HIV-1 infection. To our surprise, we found many differentially expressed genes early after infection by analyzing both newly transcribed unprocessed pre-mRNAs and fully processed mRNAs, but not by analyzing mRNAs alone, indicating a significant delay between transcription initiation and mRNA production early after HIV-1 infection. These results also show that important findings could be missed by the standard practice of analyzing mRNAs alone. We then derived the regulatory mechanisms driving the observed expression changes using integrative computational analyses. Further, we predicted drugs that could reverse the observed expression changes induced by HIV-1 infection and showed that one of the predicted drugs indeed potently inhibited HIV-1 infection. This shows that it is possible to identify candidate drugs for host-directed therapy against HIV/AIDS using our genomics-based approach.
PMCID: PMC4136300  PMID: 24850744
9.  Fragile X syndrome as a rare disease in China — Therapeutic challenges and opportunities 
Recognized as the most common inherited from of intellectual disability (ID) and the most common known monogenic cause of autism spectrum disorders (ASD), Fragile X syndrome (FXS) is identified as an unmet medical need for the development of personalized medicine and targeted therapeutics for neurodevelopment disorders as a result of improved understanding of the genetic and cellular mechanisms. Consequently promising pharmacological targets have emerged from basic and translational research, are now being pursued by global pharmaceutical and biotech companies in early proof-of-concept clinical trials. With the world's largest rare disease population, China potentially has a large number of FXS patients, many of whom are under-diagnosed or even misdiagnosed, barely with any treatment. In spite of improved awareness of FXS in recent years, big gaps still exist between China and developed countries in multiple aspects. With increased public awareness, strong government support and investment, coupled with an increasingly large number of Western-trained experienced researchers engaging in new drug discovery and development, China has the potential to become an important player in the discovery of effective diagnostics and treatments for a rare disease like FXS.
PMCID: PMC4322594
Fragile X syndrome; FMR1; Drug development; mGluR5; Translational science
10.  Nanoscale simulation of shale transport properties using the lattice Boltzmann method: permeability and diffusivity 
Scientific Reports  2015;5:8089.
Porous structures of shales are reconstructed using the markov chain monte carlo (MCMC) method based on scanning electron microscopy (SEM) images of shale samples from Sichuan Basin, China. Characterization analysis of the reconstructed shales is performed, including porosity, pore size distribution, specific surface area and pore connectivity. The lattice Boltzmann method (LBM) is adopted to simulate fluid flow and Knudsen diffusion within the reconstructed shales. Simulation results reveal that the tortuosity of the shales is much higher than that commonly employed in the Bruggeman equation, and such high tortuosity leads to extremely low intrinsic permeability. Correction of the intrinsic permeability is performed based on the dusty gas model (DGM) by considering the contribution of Knudsen diffusion to the total flow flux, resulting in apparent permeability. The correction factor over a range of Knudsen number and pressure is estimated and compared with empirical correlations in the literature. For the wide pressure range investigated, the correction factor is always greater than 1, indicating Knudsen diffusion always plays a role on shale gas transport mechanisms in the reconstructed shales. Specifically, we found that most of the values of correction factor fall in the slip and transition regime, with no Darcy flow regime observed.
PMCID: PMC4308705  PMID: 25627247
11.  The Arabidopsis alkaline ceramidase TOD1 is a key turgor pressure regulator in plant cells 
Nature Communications  2015;6:6030.
Turgor pressure plays pivotal roles in the growth and movement of walled cells that make up plants and fungi. However, the molecular mechanisms regulating turgor pressure and the coordination between turgor pressure and cell wall remodelling for cell growth remain poorly understood. Here, we report the characterization of Arabidopsis TurgOr regulation Defect 1 (TOD1), which is preferentially expressed in pollen tubes and silique guard cells. We demonstrate that TOD1 is a Golgi-localized alkaline ceramidase. tod1 mutant pollen tubes have higher turgor than wild type and show growth retardation both in pistils and in agarose medium. In addition, tod1 guard cells are insensitive to abscisic acid (ABA)-induced stomatal closure, whereas sphingosine-1-phosphate, a putative downstream component of ABA signalling and product of alkaline ceramidases, promotes closure in both wild type and tod1. Our data suggest that TOD1 acts in turgor pressure regulation in both guard cells and pollen tubes.
Turgor pressure is critical for the growth of plant cells but the mechanisms regulating turgor are poorly understood. Here, Chen et al. identify TOD1, an alkaline ceramidase, involved in sphingosine metabolism that regulates turgor during pollen tube growth and stomatal closure.
PMCID: PMC4309442  PMID: 25591940
12.  Asymmetric Engagement of Amygdala and Its Gamma Connectivity in Early Emotional Face Processing 
PLoS ONE  2015;10(1):e0115677.
The amygdala has been regarded as a key substrate for emotion processing. However, the engagement of the left and right amygdala during the early perceptual processing of different emotional faces remains unclear. We investigated the temporal profiles of oscillatory gamma activity in the amygdala and effective connectivity of the amygdala with the thalamus and cortical areas during implicit emotion-perceptual tasks using event-related magnetoencephalography (MEG). We found that within 100 ms after stimulus onset the right amygdala habituated to emotional faces rapidly (with duration around 20–30 ms), whereas activity in the left amygdala (with duration around 50–60 ms) sustained longer than that in the right. Our data suggest that the right amygdala could be linked to autonomic arousal generated by facial emotions and the left amygdala might be involved in decoding or evaluating expressive faces in the early perceptual emotion processing. The results of effective connectivity provide evidence that only negative emotional processing engages both cortical and subcortical pathways connected to the right amygdala, representing its evolutional significance (survival). These findings demonstrate the asymmetric engagement of bilateral amygdala in emotional face processing as well as the capability of MEG for assessing thalamo-cortico-limbic circuitry.
PMCID: PMC4309641  PMID: 25629899
13.  Activation of the NF-κB pathway as a mechanism of alcohol enhanced progression and metastasis of human hepatocellular carcinoma 
Molecular Cancer  2015;14(1):10.
Hepatocellular carcinoma (HCC), the most common form of primary liver cancer, is the third leading cause of cancer-related death in human. Alcohol is a known risk factor for HCC. However it is still unclear whether and how alcohol enhances the progression and metastasis of existing HCC.
Methods and results
We first retrospectively investigated 52 HCC patients (24 alcohol-drinkers and 28 non-drinkers), and found a positive correlation between alcohol consumption and advanced Tumor-Node-Metastasis (TNM) stages, higher vessel invasion and poorer prognosis. In vitro and in vivo experiments further indicated that alcohol promoted the progression and migration/invasion of HCC. Specifically, in a 3-D tumor/endothelial co-culture system, we found that alcohol enhanced the migration/invasion of HepG2 cells and increased tumor angiogenesis. Consistently, higher expression of VEGF, MCP-1 and NF-κB was observed in HCC tissues of alcohol-drinkers. Alcohol induced the accumulation of intracellular reactive oxygen species (ROS) and the activation of NF-κB signaling in HepG2 cells. Conversely, blockage of alcohol-mediated ROS accumulation and NF-κB signaling inhibited alcohol-induced expression of VEGF and MCP-1, the tumor growth, angiogenesis and metastasis.
This study suggested that chronic moderate alcohol consumption may promote the progression and metastasis of HCC; the oncogenic effect may be at least partially mediated by the ROS accumulation and NF-ĸB-dependent VEGF and MCP-1 up-regulation.
PMCID: PMC4320626  PMID: 25622857
Alcohol; Angiogenesis; Human hepatocellular cancer; Metastasis; Reactive oxygen species
14.  Potential Therapeutic Benefit of Combining Gefitinib and Tamoxifen for Treating Advanced Lung Adenocarcinoma 
BioMed Research International  2015;2015:642041.
Introduction. Epidermal growth factor receptor (EGFR) mutations are known as oncogene driver mutations and with EGFR mutations exhibit good response to the EGFR tyrosine kinase inhibitor Gefitinib. Some studies have shown that activation of estrogen and estrogen receptor α or β (ERα/β) promote adenocarcinoma. We evaluated the relationship between the two receptors and the potential therapeutic benefit with Gefitinib and Tamoxifen. Methods. We assessed the association between EGFR mutations as well as ERα/β expression/location and overall survival in a cohort of 55 patients with LAC from a single hospital. PC9 (EGFR exon 19 deletion mutant; Gefitinib-vulnerable cells) and A549 (EGFR wild type; Gefitinib-resistant cells) cancer cells were used to evaluate the in vitro therapeutic benefits of combining Gefitinib and Tamoxifen. Results. We found that the cytosolic but not the nuclear expression of ERβ was associated with better OS in LAC tumors but not associated with EGFR mutation. The in vitro study showed that combined Gefitinib and Tamoxifen resulted in increased apoptosis and cytosolic expression of ERβ. In addition, combining both medications resulted in reduced cell growth and increased the cytotoxic effect of Gefitinib. Conclusion. Tamoxifen enhanced advanced LAC cytotoxic effect induced by Gefitinib by arresting ERβ in cytosol.
PMCID: PMC4321093
15.  Genomic organization of the crested ibis MHC provides new insight into ancestral avian MHC structure 
Scientific Reports  2015;5:7963.
The major histocompatibility complex (MHC) plays an important role in immune response. Avian MHCs are not well characterized, only reporting highly compact Galliformes MHCs and extensively fragmented zebra finch MHC. We report the first genomic structure of an endangered Pelecaniformes (crested ibis) MHC containing 54 genes in three regions spanning ~500 kb. In contrast to the loose BG (26 loci within 265 kb) and Class I (11 within 150) genomic structures, the Core Region is condensed (17 within 85). Furthermore, this Region exhibits a COL11A2 gene, followed by four tandem MHC class II αβ dyads retaining two suites of anciently duplicated “αβ” lineages. Thus, the crested ibis MHC structure is entirely different from the known avian MHC architectures but similar to that of mammalian MHCs, suggesting that the fundamental structure of ancestral avian class II MHCs should be “COL11A2-IIαβ1-IIαβ2.” The gene structures, residue characteristics, and expression levels of the five class I genes reveal inter-locus functional divergence. However, phylogenetic analysis indicates that these five genes generate a well-supported intra-species clade, showing evidence for recent duplications. Our analyses suggest dramatic structural variation among avian MHC lineages, help elucidate avian MHC evolution, and provide a foundation for future conservation studies.
PMCID: PMC4302302  PMID: 25608659
16.  PNPLA3 I148M variant in nonalcoholic fatty liver disease: Demographic and ethnic characteristics and the role of the variant in nonalcoholic fatty liver fibrosis 
Patatin-like phospholipase domain-containing 3 (PNPLA3 or adiponutrin) displays anabolic and catabolic activities in lipid metabolism, and has been reported to be significantly associated with liver fat content. Various studies have established a strong link between the 148 isoleucine to methionine protein variant (I148M) of PNPLA3 and liver diseases, including nonalcoholic fatty liver disease (NAFLD). However, detailed demographic and ethnic characteristics of the I148M variant and its role in the development of nonalcoholic fatty liver fibrosis have not been fully elucidated. The present review summarizes the current knowledge on the association between the PNPLA3 I148M variant and NAFLD, and especially its role in the development of nonalcoholic fatty liver fibrosis. First, we analyze the impact of demographic and ethnic characteristics of the PNPLA3 I148M variant and the presence of metabolic syndrome on the association between PNPLA3 I148M and NAFLD. Then, we explore the role of the PNPLA3 I148M in the development of nonalcoholic fatty liver fibrosis, and hypothesize the underlying mechanisms by speculating a pro-fibrogenic network. Finally, we briefly highlight future research that may elucidate the specific mechanisms of the PNPLA3 I148M variant in fibrogenesis, which, in turn, provides a theoretical foundation and valuable experimental data for the clinical management of nonalcoholic fatty liver fibrosis.
PMCID: PMC4299331  PMID: 25624712
PNPLA3 I148M variant; Polymorphism; Nonalcoholic fatty liver disease; Nonalcoholic fatty liver fibrosis
17.  PTEN Is a Negative Regulator of NK Cell Cytolytic Function 
Human NK cells are characterized by their ability to initiate an immediate and direct cytolytic response to virally infected or malignantly transformed cells. Within human peripheral blood, the more mature CD56dim NK cell efficiently kills malignant targets at rest, whereas the less mature CD56bright NK cells cannot. In this study, we show that resting CD56bright NK cells express significantly more phosphatase and tensin homolog deleted on chromosome 10 (PTEN) protein when compared with CD56dim NK cells. Consistent with this, forced overexpression of PTEN in NK cells resulted in decreased cytolytic activity, and loss of PTEN in CD56bright NK cells resulted in elevated cytolytic activity. Comparable studies in mice showed PTEN overexpression did not alter NK cell development or NK cell–activating and inhibitory receptor expression yet, as in humans, did decrease expression of downstream NK activation targets MAPK and AKT during early cytolysis of tumor target cells. Confocal microscopy revealed that PTEN overexpression disrupts the NK cell’s ability to organize immunological synapse components including decreases in actin accumulation, polarization of the microtubule organizing center, and the convergence of cytolytic granules. In summary, our data suggest that PTEN normally works to limit the NK cell’s PI3K/AKT and MAPK pathway activation and the consequent mobilization of cytolytic mediators toward the target cell and suggest that PTEN is among the active regulatory components prior to human NK cells transitioning from the noncytolytic CD56bright NK cell to the cytolytic CD56dim NK cells.
PMCID: PMC4319309  PMID: 25595786
18.  Variants in two adjacent genes, EGLN2 and CYP2A6, influence smoking behavior related to disease risk via different mechanisms 
Human Molecular Genetics  2013;23(2):555-561.
Genome-wide significant associations with cigarettes per day (CPD) and risk for lung cancer and chronic obstructive pulmonary disease (COPD) were previously reported in a region of 19q13, including CYP2A6 (nicotine metabolism enzyme) and EGLN2 (hypoxia response). The associated single nucleotide polymorphisms (SNPs) were assumed to be proxies for functional variation in CYP2A6. Here, we demonstrate that when CYP2A6 and EGLN2 genotypes are analyzed together, the key EGLN2 variant, rs3733829, is not associated with nicotine metabolism independent of CYP2A6, but is nevertheless independently associated with CPD, and with breath carbon monoxide (CO), a phenotype associated with cigarette consumption and relevant to hypoxia. SNPs in EGLN2 are also associated with nicotine dependence and with smoking efficiency (CO/CPD). These results indicate a previously unappreciated novel mechanism behind genome-wide significant associations with cigarette consumption and disease risk unrelated to nicotine metabolism.
PMCID: PMC3869360  PMID: 24045616
19.  Parallel Functional Reorganizations of Somatosensory Areas 3b and 1, and S2 following Spinal Cord Injury in Squirrel Monkeys 
The Journal of Neuroscience  2014;34(28):9351-9363.
Multiple somatosensory cortices of adult primates reorganize following spinal cord injury, but little is known about the temporal dynamics and inter-areal differences of the reorganization. Using longitudinal high-resolution fMRI in combination with microelectrode recordings and tracer histology, we previously illustrated a two-phase dynamic spatial reorganization of digit representations in area 3b within weeks after a unilateral lesion of the dorsal column in squirrel monkeys (Chen et al., 2012). Here we report that higher-order area 1 and secondary somatosensory cortex (S2) underwent similar spatial reorganizations, which were characterized by shifted and expanded digit activations at week 4 after lesion, which then shifted back and contracted by week 8. In addition, the responsiveness of areas 3b and 1, and S2, as measured by the magnitude of the BOLD signal change to tactile stimuli, was reduced markedly at 4 weeks and then recovered to ∼50% of the prelesion level at 8 weeks, a time when behavioral recovery was complete, as assessed by successful food retrieval rates. Across animals, the extents of spatial reorganizations and changes in cortical responsiveness and activation sizes in all three areas were correlated with the degree of afferent disruption. In summary, our data show that more severe afferent disruption was associated with greater cortical plasticity and behavioral impairment. Reorganization that occurred in area 3b, area 1, and S2 were similar across most measures.
PMCID: PMC4087212  PMID: 25009268
dorsal column section; fMRI; hand; nonhuman primates; plasticity; somatosensory cortex
20.  The need to control for regression to the mean in social psychology studies 
Frontiers in Psychology  2015;5:1574.
It is common in repeated measurements for extreme values at the first measurement to approach the mean at the subsequent measurement, a phenomenon called regression to the mean (RTM). If RTM is not fully controlled, it will lead to erroneous conclusions. The wide use of repeated measurements in social psychology creates a risk that an RTM effect will influence results. However, insufficient attention is paid to RTM in most social psychological research. Notable cases include studies on the phenomena of social conformity and unrealistic optimism (Klucharev et al., 2009, 2011; Sharot et al., 2011, 2012b; Campbell-Meiklejohn et al., 2012; Kim et al., 2012; Garrett and Sharot, 2014). In Study 1, 13 university students rated and re-rated the facial attractiveness of a series of female faces as a test of the social conformity effect (Klucharev et al., 2009). In Study 2, 15 university students estimated and re-estimated their risk of experiencing a series of adverse life events as a test of the unrealistic optimism effect (Sharot et al., 2011). Although these studies used methodologies similar to those used in earlier research, the social conformity and unrealistic optimism effects were no longer evident after controlling for RTM. Based on these findings we suggest several ways to control for the RTM effect in social psychology studies, such as adding the initial rating as a covariate in regression analysis, selecting a subset of stimuli for which the participant' initial ratings were matched across experimental conditions, and using a control group.
PMCID: PMC4287101  PMID: 25620951
regression to the mean; repeated measurements; social conformity; unrealistic optimism; social psychology
21.  Re: ''Laparoscopic vs open approach to resection of hepatocellular carcinoma in patients with known cirrhosis: Systematic review and meta-analysis'' 
Twaij and colleagues have carried out a meta-analysis of cohort studies to review the currently available literature comparing laparoscopic to open resection of hepatocellular carcinoma in patients with known liver cirrhosis. We congratulate and applaud their important work, but several important issues should be noted.
PMCID: PMC4284359  PMID: 25574115
Meta-analysis; Standardized mean difference; Heterogeneity; Weighted mean difference; Sensitivity analysis
22.  Dissecting Regulation Mechanism of the FMN to Heme Interdomain Electron Transfer in Nitric Oxide Synthases 
Journal of inorganic biochemistry  2013;0:10.1016/j.jinorgbio.2013.09.005.
Nitric oxide synthase (NOS), a flavo-hemoprotein, is responsible for biosynthesis of nitric oxide (NO) in mammals. Three NOS isoforms, iNOS, eNOS and nNOS (inducible, endothelial, and neuronal NOS), achieve their biological functions by tight control of interdomain electron transfer (IET) process through interdomain interactions. In particular, the FMN–heme IET is essential in coupling electron transfer in the reductase domain with NO synthesis in the heme domain by delivery of electrons required for O2 activation at the catalytic heme site. Emerging evidence indicates that calmodulin (CaM) activates NO synthesis in eNOS and nNOS by a conformational change of the FMN domain from its shielded electron-accepting (input) state to a new electron-donating (output) state, and that CaM is also required for proper alignment of the FMN and heme domains. In the absence of a structure of full-length NOS, an integrated approach of spectroscopic, rapid kinetics and mutagenesis methods is required to unravel regulation mechanism of the FMN–heme IET process. This is to investigate the roles of the FMN domain motions and the docking between the primary functional FMN and heme domains in regulating NOS activity. The recent developments in this area that are driven by the combined approach are the focuses of this review. A better understanding of the roles of interdomain FMN/heme interactions and CaM binding may serve as a basis for the rational design of new selective modulators of the NOS enzymes.
PMCID: PMC3844001  PMID: 24084585
Nitric oxide synthase; Calmodulin; FMN; Heme; Electron transfer
23.  PQJS380 
Cancer Biology & Therapy  2013;15(1):119-127.
Acute lymphoblastic leukemia (ALL) is a malignant disorder of lymphoid progenitor cells that are committed to the B- or the T-cell lineage. The pathogenesis of ALL is heterogeneous and may be at least in part caused by genetic alterations. Although the modern sequencing technologies make it possible to rapidly discover novel genetic and epigenetic alterations and molecular targets for therapeutic intervention for ALL, conventional chemotherapy is still the most important therapeutic approach. Relapses and high morbidity and mortality remain major challenges particularly in adult patients with ALL. Therefore, development of novel chemotherapeutic agents remains in demand for ALL patients. In the course of seeking novel agents against ALL, we screened a library of small molecules and identified that PQJS380, a S-(E)-4-([7S,10S]-4-ethyl-7-isopropyl-2,5,8,12-tetraoxo-9-oxa-3,6,13,18-tetraaza-bicycle[13,2,1] octadec-1-en-10-yl)but-3-enyl octanethioate, showed potent anti-leukemia activity. PQJS380 inhibited the proliferation with IC50 values of 14.25 nM and 5 nM in REH and NALM-6 cells, respectively. PQJS380 had 10-fold higher molar potency than the front-line ALL drugs Ara-C and VP-16. The median IC50 value for leukemia blast cells from 17 patients with ALL was 52 nM. PQJS380 induced G1-phase arrest in REH cells, and S-phase in NALM-6 cells, respectively. Treatment of PQJS380 led to apoptosis in ALL cell lines (REH and NALM-6) and primary ALL cells. Our data supported that PQJS380 may be a promising lead compound for ALL treatment even though the precise targets remain to be elucidated.
PMCID: PMC3938514  PMID: 24253322
acute lymphoblastic leukemia; chemotherapeutic agent; lead compound; PQJS380; apoptosis
24.  Pharmacotherapy Effects on Smoking Cessation Vary with Nicotine Metabolism Gene (CYP2A6) 
Addiction (Abingdon, England)  2013;109(1):128-137.
Background and aims
Evidence suggests that both the nicotinic receptor α5 subunit (CHRNA5) and Cytochrome P450 2A6 (CYP2A6) genotypes influence smoking cessation success and response to pharmacotherapy. We examine the effect of CYP2A6 genotype on smoking cessation success and response to cessation pharmacotherapy, and combine these effects with those of CHRNA5 genotypes.
Placebo-controlled randomized smoking cessation trial
Ambulatory care facility in Wisconsin, USA.
Smokers (N=709) of European ancestry were randomized to placebo, bupropion, nicotine replacement therapy, or combined bupropion and nicotine replacement therapy.
Survival analysis was used to model time to relapse using nicotine metabolism derived from CYP2A6 genotype-based estimates. Slow metabolism is defined as the lowest quartile of estimated metabolic function.
CYP2A6-defined nicotine metabolic function moderated the effect of smoking cessation pharmacotherapy on smoking relapse over 90 days (Hazard Ratio (HR) = 2.81, 95%CI=1.32-5.99, p=0.0075), with pharmacotherapy significantly slowing relapse in fast (HR=0.39, 95%CI=0.28-0.55, p=1.97×10-8), but not slow, metabolizers (HR=1.09, 95%CI=0.55-2.17, p=0.80). Further, only the effect of nicotine replacement, and not bupropion, varies with CYP2A6-defined metabolic function. The effect of nicotine replacement on continuous abstinence is moderated by the combined genetic risks from CYP2A6 and CHRNA5 (interaction effect size=0.74, 95%CI=0.59-0.94, p=0.013).
Nicotine replacement therapy is effective amongst individuals with fast, but not slow, CYP2A6-defined nicotine metabolism. The effect of bupropion on relapse likelihood is unlikely affected by nicotine metabolism as estimated from CYP2A6 genotype. The variation in treatment responses amongst smokers with genes may guide future personalized smoking cessation interventions.
PMCID: PMC3946972  PMID: 24033696
Smoking Cessation; Nicotine; Metabolism; Pharmacogenetics
25.  Serum Fucosylated Prostate-specific Antigen (PSA) Improves the Differentiation of Aggressive from Non-aggressive Prostate Cancers 
Theranostics  2015;5(3):267-276.
Background: Clinically, it is still challenging to differentiate aggressive from non-aggressive prostate cancers (Pca) by non-invasive approaches. Our recent studies showed that overexpression of alpha (1-6) fucosyltransferase played an important role in Pca cells. In this study, we have investigated levels of glycoproteins and their fucosylated glycoforms in sera of Pca patients, as well as the potential utility of fucosylated glycoproteins in the identification of aggressive Pca.
Material and Methods: Serum samples from histomorphology-proven Pca cases were included. Prostate-specific antigen (PSA), tissue inhibitor of metallopeptidase 1 (TIMP1) and tissue plasminogen activator (tPA), and their fucosylated glycoforms were captured by Aleuria Aurantia Lectin (AAL), followed by the multiplex magnetic bead-based immunoassay. The level of fucosylated glycoproteins was correlated with patients' Gleason score of the tumor.
Result: Among three fucosylated glycoproteins, the fucosylated PSA was significantly increased and correlated with the tumor Gleason score (p<0.05). The ratio of fucosylated PSA showed a marked increase in aggressive tumors in comparison to non-aggressive tumors. ROC analysis also showed an improved predictive power of fucosylated PSA in the identification of aggressive Pca.
Conclusions: Our data demonstrated that fucosylated PSA has a better predictive power to differentiate aggressive tumors from non-aggressive tumors, than that of native PSA and two other glycoproteins. The fucosylated PSA has the potential to be used as a surrogate biomarker.
PMCID: PMC4279190  PMID: 25553114
prostate cancer; multiplex immunoassay; fucosylated glycoprotein; prostate-specific antigen; TIMP1.

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