Recent Submissions

  • Targeting wild-type and mutant p53 for cancer treatment

    Stewart N Loh; Blayney, Alan John (2021)
  • Charting Neurotypical Change in Complement and Cytokine Levels Across Postnatal Human Cortical Development

    Sager, Rachel (2021-12)
    A burgeoning body of evidence supports a role for immune signals in neurotypical human brain development. Furthermore, associations between neuroinflammation in development and the subsequent increased risk for psychiatric disorders indicate that an excess of immune signaling early in life damages brain function later in life. In this dissertation, I examined the postnatal expression of two major immune signaling families: complement and cytokines; and the relative contributions of neural cell types to the cortical transcriptome. I used high-throughput microarray, quantitative reverse transcription PCR, immunohistochemistry and multiplex immunoassays. I found coordinated increases in glial cell marker, complement, and cytokine transcripts from birth until the typical age of entry into school (age 5). There were two main patterns of change in gene expression encoding immune signals and their receptors: an early postnatal peak in toddlers followed by a decline in expression levels (C1Q, C3, IL-1β, CD11B, IL-1R1, IL-18) and an early postnatal increase in toddlers, followed by additional increases in adolescents and young adults (IL-6, TNF-α). Complement inhibitor mRNAs were also differentially expressed across postnatal human life, increasing before reaching a plateau around school age (CD46, CD55, CR1,) or peaking in young adulthood (SERPING1, CD59). This suggests sustained complement inhibition during adolescence. The multiple cytokine and complement family members that peaked in toddlers suggest a period of dominant immune signaling from age two to five in humans. This may be related to the proliferation or maturation of glia during early postnatal development, whereas the cytokines seen increasing in adolescents and young adults are contemporaneous with periods of proposed increases in synaptic elimination. These findings open up additional avenues of investigation into the role of immune signaling in normal mammalian brain development and support that time periods of normative increases in developmental immune factor signaling overlap with known 'windows of vulnerability' to manifesting autism and schizophrenia.
  • The Role of Laminins in the Retinal Vascular Basement Membrane

    Brunken, William J.; Watters, Jared (2021-11)
    The vascular basement membrane (vBM) of the central nervous system (CNS) is a highly specialized structure that is composed of various extracellular matrix (ECM) proteins and has many functions, including providing a point of adhesion for the cells of the vasculature, serving as a physical barrier, and providing an interface for communication with endothelial cells. One family of ECM molecules, laminins, are responsible for many of these specialized functions. There are 16 known isoforms of laminin, each consisting of a single α, β, and γ-chain. The distribution of these isoforms in the CNS vBM, however, remains unknown. Here, we used the retina to examine the distribution of laminin chains in the CNS vBM throughout development, as well as the roles of β2-containing laminins in vBM organization and γ3-containing laminins in arterial morphogenesis. The results presented in Chapter 2 demonstrate that there are dramatic changes in the temporal and spatial patterning of many of the laminin chains in the retinal vasculature throughout development, particularly the α2, α5, and γ3-chains. We deleted a key component of the CNS vBM, the laminin β2-chain, to gain a deeper understanding of how laminins affect vBM structure. Deletion of the β2-chain leads to decreased expression of several partner chains, including α2, α5, and γ3. Interestingly, the deletion of laminin β2 also leads to increased deposition of two other ECM molecules, agrin and perlecan, in the BMs of retinal veins and arteries, respectively. We also provide strong evidence that astrocytes contribute laminin 221 to the retinal vBM and that this laminin may directly regulate AQP4 expression in vascular associated astrocytic endfeet. The results presented in Chapter 3 demonstrate that laminins are involved in regulating arterial morphogenesis. Specifically, we found that γ3-containing laminins signal through dystroglycan to induce Dll4-Notch signaling, leading to decreased vascular branching and increased smooth muscle coverage: hallmarks of the arterial phenotype. Taken together, the work presented here further elucidates the structural and functional roles for laminins in the CNS vBM.

    Amack, Jeffrey, D.; Santra, Peu (2021-11)
    Vacuolar type H+-ATPase (V-ATPase) is a ubiquitously expressed enzyme complex that pumps protons across membranes. The proton-motive force generated by V-ATPase is used by cells to acidify intracellular compartments. Additionally, certain specialized tissue types have V-ATPase on plasma membranes where it secretes H+into the extracellular space. While V-ATPase activity is essential for several cellular functions, our understanding of cell-type specific functions for V-ATPase remains limited. Here, I focused on investigating V-ATPase functions in mechanosensory hair cells. Hair cells are functional units of mammalian auditory and vestibular systems. Consequently, hair cell loss leads to permanent deafness. Mutation in specific V-ATPase subunits causes sensorineural deafness in human, however, the mechanism is not well understood. I used zebrafish as model vertebrate to investigate how loss of V-ATPase function impacts hair cells. Using a combination of genetic mutations, pharmacological manipulations and live imaging of hair cells in vivo, I found that V-ATPase activity is critical for hair cell survival. Analysis of molecular markers and cellular morphologies indicates hair cells in V-ATPase mutants undergo a caspase-independent, necrosis-like death. V-ATPase mutant hair cells show a significant decrease in mitochondrial membrane potential (mPTP). On modulating mPTP pharmacologically, V-ATPase mutants show a modest but consistent improvement of hair cell survival. These results indicate mitochondrial dysfunction contributes to hair cell death in V-ATPase mutants. Next, I generated a novel cilia pH biosensor and found that hair cell kinocilia have a more basic pH than other primary cilia in zebrafish embryos. Interestingly, my collaborators and I discovered that V-ATPase subunits localize to hair cell kinocilia in zebrafish and mice, which suggests cell-type specific functions for V-ATPase in kinocilia. pH maintenance in kinocilia may be an essential function that contributes to proper kinocilia length and/or function. In conclusion, this work has uncovered a function for V-ATPase activity that is critical for hair cell survival, in part by maintaining mitochondrial health, and a function that mediates hair cell kinocilia form and function. The work presented in this thesis advances our understanding of V-ATPase functioning in hearing loss, more broadly elucidates new in vivo cell-type specific V-ATPase functions.
  • Meta-Analysis of Alzheimer's Disease Risk with Obesity, Diabetes, and Related Disorders

    Profenno, Louis A.; Porsteinsson, Anton P.; Faraone, Stephen V. (Elsevier BV, 2010-03)
    Background: Late-onset Alzheimer’s disease (AD) is a multifactorial and heterogeneous disorder with major risk factors including advanced age, presence of an apolipoprotein E 4 (APOE4) allele, and family history of AD. Other risk factors may be obesity and diabetes and related disorders, which are highly prevalent. Methods: We reviewed longitudinal epidemiological studies of body mass, diabetes, metabolic syndrome, and glucose and insulin levels on risk for AD. We conducted meta-analyses of the results from these studies. Results: For obesity assessed by body mass index, the pooled effect size for AD was 1.59 (95% confidence interval [CI] 1.02–2.5; z 2.0; p .042), and for diabetes, the pooled effect size for AD was 1.54 (95% CI 1.33–1.79; z 5.7; p .001). Egger’s test did not find significant evidence for publication bias in the meta-analysis for obesity (t 1.4, p .21) or for diabetes (t .86, p .42). Since these disorders are highly comorbid, we conducted a meta-analysis combining all studies of obesity, diabetes, and abnormal glucose or insulin levels, which yielded a highly significant pooled effect size for AD of 1.63 (95% CI 1.39 –1.92; z 5.9; p .001). Conclusions: Obesity and diabetes significantly and independently increase risk for AD. Though the level of risk is less than that with the APOE4 allele, the high prevalence of these disorders may result in substantial increases in future incidence of AD. Physiological changes common to obesity and diabetes plausibly promote AD.
  • RASD2, MYH9, and CACNG2 Genes at Chromosome 22q12 Associated with the Subgroup of Schizophrenia with Non-Deficit in Sustained Attention and Executive Function

    Liu, Yu-Li; Fann, Cathy Shen-Jang; Liu, Chih-Min; Chen, Wei J.; Wu, Jer-Yuarn; Hung, Shuen-Iu; Chen, Chun-Houh; Jou, Yuh-Shan; Liu, Shi-Kai; Hwang, Tzung-Jeng; et al. (Elsevier BV, 2008-11)
    Background: In a previous linkage study of schizophrenia that included Taiwanese samples, the marker D22S278 (22q12.3) was significantly linked to schizophrenia (p .001). Methods: We conducted fine mapping of the implicated genomic region, with 47 validated single nucleotide polymorphism (SNP) markers around 1 Mb of D22S278, in a Taiwanese sample of 218 pedigrees with at least 2 siblings affected with schizophrenia. We examined the association of these SNPs and their haplotypes with schizophrenia and with subgroups defined by the presence and absence of deficits in sustained attention as assessed by undegraded and degraded continuous performance tests (CPTs). We also examined subgroups defined by deficits in categories achieved in the Wisconsin Card Sort Test (WCST). Results: Three of five candidate vulnerability genes (RASD2, APOL5, MYH9, EIF3S7, and CACNG2), which had marginally significant associations with schizophrenia, had significant associations with schizophrenic patients who did not have deficits in sustained attention on the undegraded CPT (RASD2 gene SNP rs736212; p .0008 with single locus analysis) and the degraded CPT (MYH9 gene haplotype 1-1-1-1 of SNP rs3752463 - rs1557540 - rs713839 - rs739097; p .0059 with haplotype analysis). We also found a significant association for patients who showed no deficits in executive function as measured by categories achieved in the WCST (CACNG2 gene haplotype 2-1-1-1 of SNP rs2267360 - rs140526 - rs1883987 - rs916269; p .0163 with haplotype analysis). Conclusions: The genes RASD2, MYH9, and CACNG2 might be vulnerability genes for neuropsychologically defined subgroups of schizophrenic patients.
  • 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
  • A Twin Study of Sexual Behavior in Men

    Lyons, Michael J.; Koenen, Karestan C.; Buchting, Francisco; Meyer, Joanne M.; Eaves, Lindon; Toomey, Rosemary; Eisen, Seth A.; Goldberg, Jack; Faraone, Stephen V.; Ban, Rachel J.; et al. (Springer Science and Business Media LLC, 2004-04)
    The role of genetic and environmental influences on age of initiation of first sexual relations and engaging in sexual activity with multiple partners (10 or more partners in 1 year) was investigated in male twins (N = 6, 744) from the Vietnam Era Twin Registry. Individual differences in both types of sexual behaviors were heritable, but only age of onset of sexual relations was significantly influenced by the environment shared by the twins. There was a moderate negative correlation between age of initiation of sexual relations and the multiple partners variable; initiating sexual relations earlier was associated with a higher probability of having multiple partners. The additive genetic influence on age of initiation also influenced the multiple partners variable. The substantial unique environmental influences on each variable were uncorrelated with each other. The data suggest that the observed association between age of initiation of sexual relations and having multiple partners is due to genetic influences common to both behaviors.

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