• Absence of Gender Effects on Attention Deficit Hyperactivity Disorder: Findings in Nonreferred Subjects

      Biederman, Joseph; Kwon, Anne; Aleardi, Megan; Chouinard, Virginie-Anne; Marino, Teresa; Cole, Heather; Mick, Eric; Faraone, Stephen V. (American Psychiatric Association Publishing, 2005-06)
      Objective: In a previous study, the authors found that, compared with referred boys with attention deficit hyperactivity disorder (ADHD), girls are less likely to manifest comorbid disruptive behavior disorders and learning disabilities—characteristics that could adversely affect identification of ADHD in girls. However, because referral bias can affect outcome, these findings require replication in nonreferred groups of ADHD subjects. Method: The authors evaluated gender effects in a large group of nonreferred siblings (N=577) of probands with ADHD and non-ADHD comparison subjects. Ninetyeight of the nonreferred siblings (N=73 males, N=25 females) met the criteria for diagnosis of ADHD, and 479 (N=244 males, N=235 females) did not meet those criteria. All siblings were systematically and comprehensively assessed with measures of emotional, school, intellectual, interpersonal, and family functioning. The assessment battery used for the siblings was the same as that used for the probands. Results: The nonreferred males and females with ADHD did not differ in DSM-IV subtypes of ADHD, psychiatric comorbidity, or treatment history. They also showed similar levels of cognitive, psychosocial, school, and family functioning. Conclusions: These findings suggest that the clinical correlates of ADHD are not influenced by gender and that gender differences reported in groups of subjects seen in clinical settings may be caused by referral biases.
    • ADHD and DAT1: Further evidence of paternal over-transmission of risk alleles and haplotype

      Hawi, Z.; Kent, L.; Hill, M.; Anney, R.J.L.; Brookes, K.J.; Barry, E.; Franke, B.; Banaschewski, T.; Buitelaar, J.; Ebstein, R.; et al. (Wiley, 2009)
      We [Hawi et al. (2005); Am J Hum Genet 77:958–965] reported paternal over-transmission of risk alleles in some ADHD-associated genes. This was particularly clear in the case of the DAT1 3′-UTR VNTR. In the current investigation, we analyzed three new samples comprising of 1,248 ADHD nuclear families to examine the allelic over-transmission of DAT1 in ADHD. The IMAGE sample, the largest of the three-replication samples, provides strong support for a parent of origin effect for allele 6 and the 10 repeat allele (intron 8 and 3′-UTR VNTR, respectively) of DAT1. In addition, a similar pattern of over-transmission of paternal risk haplotypes (constructed from the above alleles) was also observed. Some support is also derived from the two smaller samples although neither is independently significant. Although the mechanism driving the paternal overtransmission of the DAT risk alleles is not known, these finding provide further support for this phenomenon.
    • ADHD Symptoms vs. Impairment: Revisited

      Barkley, Russell A.; Cunningham, Charles E.; Gordon, Michael; Faraone, Stephen V.; Lewandowski, Larry; Murphy, Kevin R. (Guilford Publications, 2006-04)
    • Adult Psychiatric Outcomes of Girls With Attention Deficit Hyperactivity Disorder: 11-Year Follow-Up in a Longitudinal Case-Control Study

      Biederman, Joseph; Petty, Carter R.; Monuteaux, Michael C.; Fried, Ronna; Byrne, Deirdre; Mirto, Tara; Spencer, Thomas; Wilens, Timothy E.; Faraone, Stephen V. (American Psychiatric Association Publishing, 2010-04)
      Objective: Few follow-up studies have been conducted of girls with ADHD, and none have followed girls into adulthood. The authors sought to estimate the prevalence of psychopathology in girls with and without ADHD followed into young adulthood. Method: The authors conducted a longitudinal case-control study of 6- to 18-year-old girls with (N=140) and without (N=122) ADHD ascertained from psychiatric and pediatric sources. At the 11-year follow-up, 96 (69%) of the girls with ADHD and 91 (75%) of the comparison girls were reassessed (mean age=22 years). Participants were blindly assessed by structured diagnostic interviews. Results: Lifetime and 1-year risks for all composite categories of psychopathology were significantly greater in girls with ADHD grown up relative to comparison girls; lifetime hazard ratios were 7.2 (95% CI=4.0–12.7) for antisocial disorders, 6.8 (95% CI=3.7–12.6) for mood disorders, 2.1 (95% CI=1.6–2.9) for anxiety disorders, 3.2 (95% CI=2.0–5.3) for developmental disorders, 2.7 (95% CI=1.6–4.3) for addictive disorders, and 3.5 (95% CI=1.6–7.3) for eating disorders. For lifetime psychopathology, all six composite categories remained statistically significant after controlling for other baseline psychopathology. Except for addictive disorders, significant 1-year findings remained significant after controlling for baseline psychopathology. The 1-year prevalences of composite disorders were not associated with lifetime or 1-year use of ADHD medication. Conclusions: By young adulthood, girls with ADHD were at high risk for antisocial, addictive, mood, anxiety, and eating disorders. These prospective findings, previously documented in boys with ADHD, provide further evidence for the high morbidity associated with ADHD across the life cycle.
    • Advanced Paternal Age and Early Onset of Schizophrenia in Sporadic Cases: Not Confounded by Parental Polygenic Risk for Schizophrenia

      Wang, Shi-Heng; Hsiao, Po-Chang; Yeh, Ling-Ling; Liu, Chih-Min; Liu, Chen-Chung; Hwang, Tzung-Jeng; Hsieh, Ming H.; Chien, Yi-Ling; Lin, Yi-Ting; Huang, Yen-Tsung; et al. (Elsevier BV, 2019-07)
      BACKGROUND:Whether paternal age effect on schizophrenia is a causation or just an association due to con-founding by selection into late parenthood is still debated. We investigated the association between paternal age andearly onset of schizophrenia in offspring, controlling for both paternal and maternal predisposition to schizophrenia asempirically estimated using polygenic risk score (PRS) derived from the Psychiatric Genomics Consortium.METHODS:Among 2923 sporadic schizophrenia cases selected from the Schizophrenia Trio Genomic Research inTaiwan project, 1649 had parents’genotyping data. The relationships of paternal schizophrenia PRS to paternal ageatfirst birth (AFB) and of maternal schizophrenia PRS to maternal AFB were examined. A logistic regression model ofpatients’early onset of schizophrenia (#18 years old) on paternal age was conducted.RESULTS:Advanced paternal age over 20 years exhibited a trend of an increasing proportion of early onset ofschizophrenia (odds ratio per 10-year increase in paternal age = 1.28,p= .007) after adjusting for maternal age, sex,and age. Older paternal AFB also exhibited an increasing trend of paternal schizophrenia PRS. Additionally, aU-shaped relationship between maternal AFB and maternal schizophrenia PRS was observed. After adjusting forboth paternal and maternal schizophrenia PRS, the association of paternal age with patients’early onset ofschizophrenia remained (odds ratio = 1.29,p= .04).CONCLUSIONS:The association between paternal age and early onset of schizophrenia was not confounded byparental PRS for schizophrenia, which partially captures parental genetic vulnerability to schizophrenia. Ourfindingssupport an independent role of paternal age per se in increased risk of early onset of schizophrenia in offspring
    • Age-Dependent Decline of Symptoms of Attention Deficit Hyperactivity Disorder: Impact of Remission Definition and Symptom Type

      Biederman, J. (American Psychiatric Association Publishing, 2000-05-01)
      Objective: Symptom decline in attention deficit hyperactivity disorder (ADHD) was examined with different definitions of remission. Method: Symptoms in 128 boys were measured five times over 4 years. The prevalences of syndromatic (less than full syndrome), symptomatic (less than subthreshold diagnosis), and functional (full recovery) remission were estimated as a function of age with multivariate logistic regression. Results: Age was significantly associated with decline in total ADHD symptoms and symptoms of hyperactivity, impulsivity, and inattention. Symptoms of inattention remitted for fewer subjects than did symptoms of hyperactivity or impulsivity. The proportion of subjects experiencing remission varied considerably with the definition used (highest for syndromatic remission, lowest for functional remission). Conclusions: These results indicate that differences in reported remission rates reflect the definition used rather than the disorder’s course. They provide systematic support for the clinical observation that hyperactivity and impulsivity symptoms tend to decline at a higher rate than inattention symptoms.
    • Agonal factors distort gene-expression patterns in human postmortem brains

      Dai, Jiacheng; Chen, Yu; Chen, Chao; Liu, Chunyu (Cold Spring Harbor Laboratory, 2020-07-12)
      Agonal factors, the conditions that occur just prior to death, can impact the molecular quality of postmortem brains, influencing gene expression results. Nevertheless, study designs using postmortem brain tissue rarely, if ever, account for these factors, and previous studies had not documented nor adjusted for agonal factors. Our study used gene expression data of 262 samples from ROSMAP with the following terminal states recorded for each donor: surgery, fever, infection, unconsciousness, difficulty breathing, and mechanical ventilation. Performed differential gene expression and weighted gene co-expression network analyses (WGCNA), fever and infection were the primary contributors to brain gene expression changes. Fever and infection also contributed to brain cell-type specific gene expression and cell proportion changes. Furthermore, the gene expression patterns implicated in fever and infection were unique to other agonal factors. We also found that previous studies of gene expression in postmortem brains were confounded by variables of hypoxia or oxygen level pathways. Therefore, correction for agonal factors through probabilistic estimation of expression residuals (PEER) or surrogate variable analysis (SVA) is recommended to control for unknown agonal factors. Our analyses revealed fever and infection contributing to gene expression changes in postmortem brains and emphasized the necessity of study designs that document and account for agonal factors.
    • Agonal factors distort gene-expression patterns in human postmortem brains

      Dai, Jiacheng; Chen, Yu; Chen, Chao; Liu, Chunyu; Faraone, Stephen V. (Cold Spring Harbor Laboratory, 2020-07-12)
      Agonal factors, the conditions that occur just prior to death, can impact the molecular quality of postmortem brains, influencing gene expression results. Nevertheless, study designs using postmortem brain tissue rarely, if ever, account for these factors, and previous studies had not documented nor adjusted for agonal factors. Our study used gene expression data of 262 samples from ROSMAP with the following terminal states recorded for each donor: surgery, fever, infection, unconsciousness, difficulty breathing, and mechanical ventilation. Performed differential gene expression and weighted gene co-expression network analyses (WGCNA), fever and infection were the primary contributors to brain gene expression changes. Fever and infection also contributed to brain cell-type specific gene expression and cell proportion changes. Furthermore, the gene expression patterns implicated in fever and infection were unique to other agonal factors. We also found that previous studies of gene expression in postmortem brains were confounded by variables of hypoxia or oxygen level pathways. Therefore, correction for agonal factors through probabilistic estimation of expression residuals (PEER) or surrogate variable analysis (SVA) is recommended to control for unknown agonal factors. Our analyses revealed fever and infection contributing to gene expression changes in postmortem brains and emphasized the necessity of study designs that document and account for agonal factors.
    • ALTERATIONS IN CELLULAR GLUTAMATE TRANSPORT DO NOT CONTRIBUTE TONEURONAL CELL DEATHIN A MIXED CORTICAL CELL CULTURE MODEL OF HYPOGLYCEMIA

      Hewett, Sandra; Thorn, Trista (2013)
      Severe hypoglycemia is associated with neurological deficits thatwhen left untreated can lead to frank neuronal cell death. Despite longstanding evidence in both in vitro andin vivomodels that hypoglycemic neuronalcell death is mediated by glutamateexcitotoxicity, the cellularand molecular mechanisms involved remain incompletelydefined. Toward this end, werecently reported that glutamate efflux from astrocytes via the anionic cystine/glutamate antiporter, system xc-, contributed to glucose-deprivation (GD) induced neuronal cell death in vitro. However,the precise mechanism by which system xc-activity links to glutamate-mediated injury has yet to be determined. Thus, the overall purpose of this thesis was toinvestigate whetherchanges insystem xc-expression in our astrocyte and mixed cortical cell cultures and/or alterations in glutamate handling in a mixed cortical culture modelfollowing glucose deprivationoccur(s). Toward the former, no change in the expression of mRNA (GD up to 4 h) or protein(GD up to 8 h) ofxCT, the functional light chain of system xc-, in either astrocyte or mixed cortical cell cultureswas demonstrated via quantitative RT-PCR or western blot analysis, respectively. Further, aglycemic neuronal injury, induced by 6 or 8 h of glucose deprivation, was not prevented by the addition of either actinomycin D (10 μg/mL) or cycloheximide (1 μg/mL), demonstrating no requirement for transcription or translation, respectively. Toward the latter, alterations in classical glutamate re-uptake transporter function also did not appear to be altered. Media containing added glutamate taken from control astrocytes or astrocytes deprived of glucose (6 h) was equally toxic to pure neuronal cultures, demonstrating no alterations in glutamate removal between control and glucose-deprived cells. However, neurons in mixed cortical cell cultures deprived of glucose showed increased neuronal cell death over those maintained in glucose-containing medium when exposed directly to equimolar concentrations of either glutamate or NMDA.Similarly, this increased neuronal death in glucose deprived mixed cortical cultures was shown across several different time points using constant concentrations of either glutamate or NMDA. Lastly, we show that neurons in our mixed cortical cultures are fully protected from excitotoxic cell death when system xc-and NMDA receptor inhibitors are added up to two hours following the initiation of glucose deprivation. Overall, our data reveal that neither enhanced system xc-expressionnor impaired glutamate uptake could account for the neuronal cell death induced by glucose deprivation, but that energy deprived neurons appear simply more susceptible to excitotoxic insults. Therefore, physiological levels of glutamate releasedfrom astrocyte system xc-maybe sufficient to mediate neuronal cell death under aglycemic conditions.
    • Alternative splicing dysregulation in mental disorders

      Glatt, Stephen; Cohen, Ori S (2014)
      The brain's ability to adapt ultimately depends on the efficiency with which neuronal connections are made, destroyed, or manipulated. This connectivity is largely controlled by synaptic plasticity, which creates, strengthens, or weakens signals that are necessary for appropriate functioning of the organism. This constant rewiring allows an organism to learn, mature, and cope with the ever-changing environment. However, this rewiring is dependent on the ability to make new proteins, which highlights the importance of transcription, translation, and post-translational modification in the process of synaptic plasticity. Among these cellular functions, transcription plays a key role in providing the necessary variability that is required to regulate neurodevelopment and cognitive behaviors. During transcription, alternative splicing regulates the contents of transcriptomic elements by cutting and stitching the transcribed pre-mRNA and adjusting the configuration of the mature mRNA(s) to meet the necessary cellular requirements. Therefore, it is conceivable that alternative splicing abnormalities can result in inappropriate adjustment of the transcriptome and result in pathological adaptation. In this dissertation, I review the evidence of dysfunctional gene splicing in neuropsychiatric disorders. Then I evaluate the extent of alternative splicing in an animal model for social interaction. This model utilizes valproic acid exposure at a critical developmental period to illicit significant and long-lasting changes in social interaction behavior. Next, I explore the abundance and types of alternative-splicing dysregulationin postmortembrain tissue samples from schizophrenia patients as compared to non-psychotic comparison subjects. Finally, I describe the mechanisms by which a schizophrenia-associated polymorphism in a strong candidate gene (DRD2, which encodes the D2 dopamine receptor) disrupts alternative splicing and leads to inappropriate transcription that is associated with cognitive dysfunction. Collectively, these results reinforce the notion that consideration of genetic variants that dysregulate particular mRNA isoforms and understanding the biological consequence of expressing such isoforms is a crucial step in our efforts to understand human behavior and to develop therapeutic interventions for mental disorders.
    • Analysis of cdGAP in Extracellular Matrix Rigidity Sensing and Cell Migration

      Turner, Chris; Wormer, Duncan (2014)
      CdGAP is a Rac1/Cdc42 specific GTPase activating protein that localizes to cell–matrix adhesions through an interaction with the adhesion scaffold α-parvin/actopaxin to regulate lamellipodia formation and cell spreading. In chapter 2 of this thesis, using a combination of siRNA-mediated silencing and over expression, I show that cdGAP negatively regulates directed and random migration by controlling adhesion maturation and dynamics through the regulation of both adhesion assembly and disassembly. Interestingly, cdGAP was also localized to adhesions formed in three-dimensional matrix environments and cdGAP depletion promoted cancer cell migration and invasion through 3D matrices. Cell migration in 3D CDMs more closely approximates the topography of in vitroconnective tissues, suggesting that cdGAP likely plays an important regulatory role in cell migration in vivo. Other aspects of the extracellular matrix also influence cell migration. Specifically, motile cells are capable of sensing the stiffness of the surrounding extracellular matrix through integrin-mediated focal adhesions and migrate towards regions of higher rigidity in a process known as durotaxis. Durotaxis plays an important role in normal development and disease progression, including tumor invasion and metastasis. However, the signaling mechanisms underlying focal adhesion-mediated rigidity sensing and durotaxis are poorly understood. In chapter three of this thesis, I utilizefibronectin-coated polydimethoxysiloxane gelsto manipulate substrate compliance, and show that cdGAP is necessary for U2OS osteosarcoma cells to coordinate cell shape changes and migration as a function of extracellular matrix stiffness. CdGAP regulated rigidity-dependent motility by controlling membrane protrusion and adhesion dynamics, as well as by modulating Rac1 activity. I also found that CdGAP was necessary for U2OS cell durotaxis. Taken together, these data identify cdGAP as an important component of an integrin-mediated signaling pathway that senses and responds to mechanical cues in the extracellular matrix in order to coordinate directed cell motility.These findings highlight the importance of GAP proteins in the regulation of Rho family GTPases andprovide insight into how GAPs co-ordinate the cell migration machinery.
    • ANALYSIS OF INOSITOL 1,4,5-TRISPHOSPHATE RECEPTOR-ERLIN1/2 COMPLEX-RNF170 AXIS MUTATIONS THAT RESULT IN NEURODEGENERATIVE DISEASE

      Wojcikiewicz, Richard; WRIGHT, FORREST (2017)
      Inositol 1,4,5-trisphosphate receptors (IP3Rs) are endoplasmic reticulum (ER) proteins that assemble into tetrameric IP3- and Ca2+-gated Ca2+ channels. Activation of IP3Rs begins with stimulation of cell surface receptors that elevate cytosolic IP3 levels. IP3, with its co-agonist Ca2+, binds to IP3Rs and causes a conformational change that results in the opening of the channel aperture, allowing for Ca2+ ions to flow from stores within the ER lumen to the cytosol and thereby promoting a number of Ca2+-dependent cellular events, including secretion, neurotransmitter release and cell division. Intriguingly, it appears that the same conformational change that IP3Rs undergo during activation makes them a target for degradation by the ubiquitin-proteasome pathway. This processing allows the cell to fine-tune its internal Ca2+ responses to extracellular stimuli. In the Wojcikiewicz lab, it was discovered that processing of activated IP3Rs is mediated by the Erlin1/2 complex, a large (~2MDa) complex composed of the proteins Erlin1 and Erlin2. Constitutively-associated with the Erlin1/2 complex is the E3 ubiquitin ligase RNF170. Thus, we employed TALEN and CRISPR/Cas9-mediated gene editing technologies to abrogate expression of these three proteins to define their roles in this process. Remarkably, analysis of cells lacking RNF170 showed that it is required for all ubiquitination of activated IP3Rs. Investigation into the roles of Erlin1 and Erlin2 uncovered that Erlin2 is the “dominant partner” in the Erlin1/2 complex, mediating complex interaction with activated IP3Rs and bringing RNF170 into place to allow for ubiquitination to proceed. Mutations to RNF170 (R199C) and Erlin2 (T65I) have been identified as causative for progressive neurodegenerative diseases. Investigation of the R199C mutation on IP3R processing by RNF170 uncovered that while the mutation did not affect normal RNF170 function, it destabilized the RNF170 protein, resulting in a significantly reduced cellular complement of RNF170 and inhibition of IP3R degradation. Analysis of the Erlin2 T65I mutation showed that the effect of the mutation on Erlin1/2 complex function was two-fold. First, Erlin2 T65I interaction with activated IP3Rs was completely blocked, thereby inhibiting recruitment of RNF170 and subsequent ubiquitination and processing. Second, normal binding of the Erlin1/2 complex to phosphoinositol-3-phosphate (PI(3)P) – the significance and function of which remains undefined – was drastically inhibited. Examination of complex assembly and stability by SDS-PAGE and Native PAGE showed no destabilization of individual Erlin2 proteins nor of overall Erlin1/2 complex assembly. These data demonstrate that proper and tight control of IP3R levels in the cell are critical to overall cellular homeostasis, as disruptive mutations to requisite mediators of IP3R processing - the Erlin1/2 complex and RNF170 – result in the development of progressive neurodegenerative disease.
    • ANALYSIS OF TEMPERATURE SENSITIVE CYK-1 MUTATIONS EFFECT ON MUSCLE DEVELOPMENT ON CAENORHABDITIS ELEGAN SLARVAE

      Pruyne, David; Laszlo, Arianna (2017)
      Sarcomeres are the most basic unit of muscle cells. Formins are actin regulatory proteins that are important for actin filament polymerization and nucleation, and might be responsible for the actin filamentassembly in sarcomeres. In Caenorhabditis elegans, two formins (CYK-1 and FHOD-1) were found in the body wall muscle (BWM), specifically in the Z-line of sarcomeres. Previously, BWM were analyzed in null cyk-1(ok2300) mutant worms, derived from heterozygous parents, and fhod-1(tm2363) mutantworms, andwere found to have smaller muscles than wild-type worms. Yet, there was still functional CYK-1 present in the worms due to inherited maternal CYK-1. To eliminate this potential source of CYK-1, cyk-1(or596ts) temperature sensitive mutant worms were used to allow for all CYK-1 to be non-functional at 26°C. The focus of this study was to understand the importance of cyk-1on muscle development in C. eleganslarvae. Wild-type, fhod-1(tm2363), cyk-1(or596ts), and fhod-1(tm2363);cyk-1(or596ts) double mutant wormsat L1 larval stage were observed for worm shape and muscle abnormalities. Abnormal worm shapes were observed in fhod-1, cyk-1, and more commonly in fhod-1;cyk-1mutant worms at permissive and restrictive temperatures. Abnormal muscle was observed in both permissive and restrictive temperatures forfhod-1, cyk-1, and fhod-1;cyk-1mutant worms that had abnormal worm shapes, while all worms that had normal body shape usually had normal muscle at both temperatures. Worms were alsotested to determine long-termeffects of cyk-1and fhod-1mutations on muscle development. Worms were held at permissive or restrictive temperatures for various times. Fhod-1and cyk-1mutant worms showed reduced muscle size compared to wild-type, while fhod-1;cyk-1mutant worms displayed a more severelyreduced muscle size. Next, cyk-1orfhod-1were tested to see whether they can rescue muscle cell size after mosaic expressionin a cyk-1(-) or fhod-1(-) mutant worm background. Fhod-1(+) muscle cells showeda significant increase in muscle cell size compared to fhod-1(-) cells, while cyk-1(+) muscle cells showeda non-significant increase in muscle size compared to cyk-1(+/-) cells. This shows cell-autonomousexpressionoffhod-1influencesmuscle growth, while cyk-1expression in another organ might influence muscle development.
    • ANTIVIRAL ACTIVITY AND MECHANISM OF ACTION OF A NOVEL URACIL ANALOG FOR VARICELLA-ZOSTER VIRUS

      Moffat, Jennifer; DE, CHANDRAV (2015)
      The alphaherpesvirus varicella-zoster virus (VZV) is widespread in humans. VZV causes primary and recurrent diseases that are preventable with live vaccines and are treatable with antiviral drugs. New antiviral drugs for varicella-zoster virus (VZV) with increased potency are needed, especially to prevent post-herpetic neuralgia. The purpose of this project was to evaluate β-L-1-[5-(E-2-Bromovinyl)-2-(hydroxymethyl)-1,3-dioxolan-4- yl)] uracil (L-BHDU) and 5′-O-valyl-L-BHDU for efficacy, safety, resistance, and mechanism of action in three models of VZV replication: primary human foreskin fibroblasts (HFFs), skin organ culture (SOC) and in SCID-Hu mice with skin xenografts. We found that L-BHDU and valyl-L-BHDU were safe and effective against VZV in culture and in a mouse model. Herpes simplex virus Type 1 was also sensitive to LBHDU in cultured cells. The mechanism of action of L-BHDU and its effect on drugdrug interactions were not known. Given its similar structure to brivudine (BVdU), we addressed whether L-BHDU, like BVdU, inhibits 5-fluorouracil (5-FU) metabolism. LBHDU did not interfere with 5FU metabolism, indicating that L-BHDU is a safer drug than BVdU. However, L-BHDU antagonized the activity of acyclovir (ACV), BVdU and foscarnet (PFA) in cultured cells, which was due to competition for phosphorylation by VZV thymidine kinase (TK). The mechanism of action of L-BHDU was studied by evaluating its activity against related α-herpesviruses and by analyzing resistant VZV viii strains. VZV strains resistant to L-BHDU (L-BHDUR ) were cross-resistant to ACV and BVdU but not to PFA and cidofovir (CDV). Whole genome sequencing of L-BHDUR strains identified mutations in ATP-binding (G22R) and nucleoside binding (R130Q) domains of VZV TK. The purified L-BHDUR TKs were enzymatically inactive and failed to phosphorylate the drug. In wild type VZV- infected cells, L-BHDU was converted to L-BHDU mono- and diphosphate forms; cells infected with L-BHDUR virus did not phosphorylate the drug. We also investigated whether addition of nucleosides reversed LBHDU inhibition of VZV in dividing and quiescent HFFs. Excess thymidine and uridine, but not purines, in proportion to L-BHDU restored VZV replication only in dividing cells, suggesting that the active form of L-BHDU interfered with pyrimidine biosynthesis. Like other herpesviruses, VZV infection induced thymidine triphosphate (dTTP) in confluent cells while L-BHDU treatment decreased the dTTP pool. Some herpesviruses raise dNTP pools by inducing cellular enzymes. However, VZV infection did not increase cellular thymidylate synthase (TS) expression to facilitate viral replication. Furthermore, the active form of L-BHDU did not interfere with cellular metabolism, suggesting a viral target. Further studies are required to identify the target(s) of L-BHDU active form(s).
    • Association betweenDRD2/DRD4interaction and conduct disorder: A potential developmental pathway to alcohol dependence

      Mota, Nina R.; Bau, Claiton H. D.; Banaschewski, Tobias; Buitelaar, Jan K.; Ebstein, Richard P.; Franke, Barbara; Gill, Michael; Kuntsi, Jonna; Manor, Iris; Miranda, Ana; et al. (Wiley, 2013-07-02)
    • Association of genetic risk severity with ADHD clinical characteristics

      Kotte, Amelia; Faraone, Stephen V.; Biederman, Joseph (Wiley, 2013-10-17)
      This study sought to examine the association between the cumulative risk severity conferred by the total number of attention-deficit/hyperactivity disorder (ADHD) risk alleles of the DAT1 3′UTR variable number tandem repeat (VNTR), DRD4 Exon 3 VNTR, and 5-HTTLPR with ADHD characteristics, clinical correlates, and functional outcomes in a pediatric sample. Participants were derived from case–control family studies of boys and girls diagnosed with ADHD, a genetic linkage study of families with children with ADHD, and a family genetic study of pediatric bipolar disorder. Caucasian children 18 and younger with and without ADHD and with available genetic data were included in this analysis (N = 591). The association of genetic risk severity with sociodemographic, clinical characteristics, neuropsychological, emotional, and behavioral correlates was examined in the entire sample, in the sample with ADHD, and in the sample without ADHD, respectively. Greater genetic risk severity was significantly associated with the presence of disruptive behavior disorders in the entire sample and oppositional defiant disorder in participants with ADHD. Greater genetic risk severity was also associated with the absence of anxiety disorders, specifically with the absence of agoraphobia in the context of ADHD. Additionally, one ADHD symptom was significantly associated with greater genetic risk severity. Genetic risk severity is significantly associated with ADHD clinical characteristics and co-morbid disorders, and the nature of these associations may vary on the type (externalizing vs. internalizing) of the disorder. © 2013 Wiley Periodicals, Inc.
    • Associations Between ADHD and Psychoactive Substance use Disorders:Findings from a Longitudinal Study of High-Risk Siblings of ADHD Children

      Milberger, Sharon; Biederman, Joseph; Faraone, Stephen V.; Wilens, Timothy; Chu, Monica P. (Wiley, 1997-01)
      The purpose of this study was to determine whether the single nucleotide polymorphisms (SNPs) within candidate genes for attention deficit hyperactivity disorder (ADHD) are associated with the age at onset for ADHD. One hundred and forty-three SNPs were genotyped across five candidate genes (DRD5, SLC6A3, HTR1B, SNAP25, DRD4) for ADHD in 229 families with at least one affected offspring. SNPs with the highest estimated power to detect an association with age at onset were selected for each candidate gene, using a power-based screening procedure that does not compromise the nominal significance level. A time-to-onset analysis for family-based samples was performed on these SNPs to determine if an association exists with age at onset for ADHD. Seven consecutive SNPs surrounding the D5 dopamine receptor gene (DRD5), were associated with the age at onset for ADHD; FDR adjusted q-values ranged from 0.008 to 0.023. This analysis indicates that individuals with the risk genotype develop ADHD earlier than individuals with any other genotype. A haplotype analysis across the 6 significant SNPs that were in linkage disequilibrium with one another, CTCATA, was also found to be significant (p-value = 0.02). We did not observe significant associations with age at onset for the other candidate loci tested. Although definitive conclusions await independent replication, these results suggest that a variant in DRD5 may affect age at onset for ADHD
    • Associations between neurodevelopmental genes, neuroanatomy, and ultra high risk symptoms of psychosis in 22q11.2 deletion syndrome

      Thompson, Carlie A.; Karelis, Jason; Middleton, Frank A.; Gentile, Karen; Coman, Ioana L.; Radoeva, Petya D.; Mehta, Rashi; Fremont, Wanda P.; Antshel, Kevin M.; Faraone, Stephen V.; et al. (Wiley, 2017-01-31)
      22q11.2 deletion syndrome is a neurogenetic disorder resulting in the deletion of over 40 genes. Up to 40% of individuals with 22q11.2DS develop schizophrenia, though little is known about the underlying mechanisms. We hypothesized that allelic variation in functional polymorphisms in seven genes unique to the deleted region would affect lobar brain volumes, which would predict risk for psychosis in youth with 22q11.2DS. Participants included 56 individuals (30 males) with 22q11.2DS. Anatomic MR images were collected and processed using Freesurfer. Participants were genotyped for 10 SNPs in the COMT, DGCR8, GNB1L, PIK4CA, PRODH, RTN4R, and ZDHHC8 genes. All subjects were assessed for ultra high risk symptoms of psychosis. Allelic variation of the rs701428 SNP of RTN4R was significantly associated with volumetric differences in gray matter of the lingual gyrus and cuneus of the occipital lobe. Moreover, occipital gray matter volumes were robustly associated with ultra high risk symptoms of psychosis in the presence of the G allele of rs701428. Our results suggest that RTN4R, a relatively under-studied gene at the 22q11 locus, constitutes a susceptibility gene for psychosis in individuals with this syndrome through its alteration of the architecture of the brain. © 2017 Wiley Periodicals, Inc.
    • Autism spectrum disorder traits in SLC9A9 knock-out mice

      Faraone, Stephen; Yang, Lina (2014)
      utism spectrum disorders (ASDs) are a group of neurodevelopmental disorders which begin in childhood and persist into adulthood. They cause lifelong impairments and are associated with substantial burdens to patients, families and society. Genetic studies have implicated the sodium/proton exchanger (NHE) nine gene, SLC9A9, to ASDs and attention-deficit/hyperactivity disorder (ADHD). SLC9A9 encodes, NHE9, a membrane protein of the late recycling endosomes. The recycling endosome plays an important role in synapse development and plasticity by regulating the trafficking of membrane neurotransmitter receptors and transporters. Here we tested the hypothesis thatSLC9A9 knock-out (KO) mice would show ADHD-like and ASD-like traits. Ultrasonic vocalization recording showed that SLC9A9 KO mice emitted fewer calls and had shorter call durations, which suggest communication impairment. SLC9A9 KO mice lacked a preference for social novelty, but did not show deficits in social approach; SLC9A9 KO mice spent more time self-grooming, an indicator for restricted and repetitive behavior. We did not observe hyperactivity or other behavior impairments which are commonly comorbid with ASDs in human, such as anxiety-like behavior. Our study is the first animal behavior study that links SLC9A9 to ASDs. By eliminating NHE9 activity, it provides strong evidence that lack of SLC9A9 leads to ASD-like behaviors in mice and provides the field with a new mouse model of ASDs.