Arsop.it
Neurol Sci (2015) 36:215–220
COMT and STH polymorphisms interaction on cognitionin schizophrenia
Marta Bosia • Alessandro Pigoni • Adele Pirovano • Cristina Lorenzi •Marco Spangaro • Mariachiara Buonocore • Margherita Bechi • Federica Cocchi •Carmelo Guglielmino • Placido Bramanti • Enrico Smeraldi • Roberto Cavallaro
Received: 11 March 2014 / Accepted: 29 August 2014 / Published online: 5 October 2014Ó Springer-Verlag Italia 2014
Catechol-O-methyltransferase (COMT) gene, a
Moreover, a significant interaction between COMT and
key regulator of prefrontal cortex (PFC) dopamine (DA)
STH polymorphisms was found on executive functions,
availability, has been extensively studied in relation to
with COMT Val/Val and STH R carriers performing
cognitive domains, mainly executive functions, that are
worse. Our results showed a significant interaction effect of
impaired in schizophrenia, but results are still controver-
COMT and STH polymorphisms on cognitive perfor-
sial. Since recent studies in patients affected by neurode-
mances, strengthening the involvement of STH in cognitive
generative and psychiatric disorders suggested a role of
saitohin (STH) gene as a concurring factor in hypofron-
impaired in schizophrenia.
tality, we hypothesize that STH and COMT polymor-phisms could have an additive effect on cognition in
COMT Saitohin Cognition
schizophrenia. Three forty three clinically stabilized
Hypofrontality Schizophrenia Neurodegeneration
patients with schizophrenia were assessed with a broadneuropsychological battery including the Brief Assessmentof Cognition in Schizophrenia, the Wisconsin Card Sorting
Test and the Continuous Performance Test and were gen-otyped for COMT Val108/158Met and STH Q7R poly-
Schizophrenia is a chronic mental illness affecting almost
morphisms. We observed the effects of COMT on speed of
1 % of the population, characterized by cognitive and
processing and executive functions, as well as a significant
functional deficits leading to poor functional outcome and
effect of STH on executive functions performances.
social disruption
In the past decades, several studies addressed to the
biological bases of cognitive impairment in schizophrenia,
M. Bosia (&) C. Lorenzi M. Spangaro M. Buonocore
evaluating the effects of different polymorphisms, mainly
M. Bechi F. Cocchi C. Guglielmino E. Smeraldi R. Cavallaro
in genes involved in neurotransmission and also in neuro-
Department of Clinical Neurosciences, IRCCS San Raffaele
development and neurodegeneration processes [].
Scientific Institute, Milan, Italy
Most consistent results have been found for a single
nucleotide polymorphism in the gene coding for Catechol-
O-methyltransferase (COMT), an enzyme that significantly
Institute for Advanced Study IUSS, Center for Neurolinguistics
contributes to the removal of dopamine (DA) from the
and Theoretical Syntax (NeTS), Pavia, Italy
synapse in the prefrontal cortex (PFC). The substitution ofMet for Val at codon 108/158 results in the transcription of
A. Pigoni A. Pirovano M. Spangaro E. Smeraldi R. Cavallaro
a thermolabile variant with approximately 40 % less
Universita Vita -Salute San Raffaele, Milan, Italy
enzymatic activity, leading to greater availability of DA inthe PFC Numerous studies identified associations
between COMT genotype and cognition in patients with
IRCCS Centro Neurolesi ‘‘Bonino Pulejo'', Via Palermo 113,98121 Messina, Italy
schizophrenia and their relatives, with homozygous for
Neurol Sci (2015) 36:215–220
Met allele performing better than Val homozygous in test
of the study, informed consent to participation was
evaluating cognitive functions relying on PFC More-
obtained. The protocol was approved by the local ethical
over, we previously reported an association between
committee and followed the principles of the Declaration
COMT genotype and improvement after cognitive reme-
of Helsinki.
diation [], also in relation to antipsychotic treatment However, there have also been negative findings thus
pointing out the need to further explore other contributingfactors that may interact with COMT. In particular, a large
All patients underwent a venous blood sample for geno-
study exploring the effect of COMT Val108/158Met
typic analysis. DNA was extracted from whole blood by
polymorphism on executive functions, both in healthy
manual extraction, using the ‘‘Illustra blood genomicPrep
controls and in patients with schizophrenia, concluded that
Midi Flow kit'' (GE Healthcare, Milan, Italy).
the relationship between COMT polymorphism and exec-
For COMT Val108/158Met, polymerase chain reaction
utive performances was limited to the healthy control
(PCR) was performed with the following primers: 50-AC
Recent studies focused on the effect of saitohin (STH)
CTGACAA-30. The PCR reaction was carried out by ABI
gene, located in intron 9 of the human tau gene, in several
9700 PCR thermal-cycler (Applied Biosystems, APPLE-
neurodegenerative disorders, mainly dementia processes
RA) in a 10 ll volume containing 150 ng of genomic
[, STH gene contains a single nucleotide polymor-
DNA, 5 pmol of each primer, 10 nmol of dNTPs' mix,
phism (A/G), which changes glutamine residue 7 to argi-
109 HotMaster Taq Buffer and 0.5 U of HotMaster Taq
nine (Q7R) ]. Interestingly, Borroni et al. [found
DNA Polymerase (Eppendorf, Milan, Italy). The amplified
an association between H2 haplotype, in complete linkage
fragment was then purified by Multi-Screen Colum Loader
disequilibrium with the STH R allele ], and both greater
(MILLIPORE), filled up and packaged with Sephadex
anterior brain hypoperfusion and worse clinical prognosis
G-50 (Sigma–Aldrich's) to remove residual PCR reagents.
in patients affected by frontotemporal dementia (FTLD). In
An aliquot of purified PCR product was then used to per-
an Italian sample of patients affected by sporadic dementia,
form sequencing reaction, using DYEnamic ET Dye Ter-
Lorenzi et al. ] observed significant interactions
minator Cycle Sequencing Kit (GE Healthcare, Milan,
between STH and 5-HTTLPR, as a potential susceptibility
Italy). In its turn, sequencing reaction product, was purified
factor for neurodegenerative diseases. Bosia et al. [
following the above-mentioned protocol, to remove the
evaluated the role of the STH polymorphism in the cog-
excess of fluorescent dyes not incorporated in the DNA
nitive decline in schizophrenia, reporting an association
fragment. The fragment was then sequenced by MegaB-
between the R allele and poorer executive performances.
ACE 500 genetic analyzer (GE Healthcare, Milan, Italy)
Based on these data, it appears worth of interest to study
under standard conditions.
the possible interactions between COMT and STH poly-
For the STH Q7R polymorphism, a PCR was performed
morphisms, both hypothesized to be concurring factors
with the following primers: 50-CCCTGTAAACTCTGAC
contributing to PFC functions and cognitive performances,
CACAC-30 and 50-ACAGGGAAGCTACTTCCCATG-30.
especially executive functions. In this study we thus ana-
The PCR reaction was carried out by ABI 9700 PCR
lyzed the possible effects and interactions of STH and
thermal-cycler (Applied Biosystems, APPLERA) as fol-
COMT polymorphisms on cognition in a sample of patients
lows: after a first step at 94 °C for 3 min, steps of 94 °C for
affected by schizophrenia.
30 min, 60 °C for 30 min, 70 °C 30 min for 35 cycles.
Then, a final extension step at 70 °C for 6 min was added.
PCR product was digested using HinfI (New England
Materials and methods
Biolabs, England, UK) at 37 °C overnight; fragments wereseparated in 3 % Seakem agarose gel with ethidium bro-
A sample of 343 Caucasian biologically unrelated out-
mide. The cleaved bands were visualized by ultraviolet
patients were recruited at the San Raffaele Scientific
light. Depending on the presence of one or two restriction
Institute of Milan (Italy). Inclusion criteria were: diag-
HinfI sites, either two fragments 171?55 bp (A or Q allele)
or three fragments 97?74?55 bp (G or R allele) were
18–70 years, stable antipsychotic treatment since at least
3 months and good response (defined as a reduction of30 % or more in PANSS Total Score after 3 months of
treatment). Exclusion criteria were: psychiatric comor-bidities, mental retardation, substance abuse, neurological
Basic clinical and demographic data were collected from
disorders and brain injury. After a complete description
clinical records.
Neurol Sci (2015) 36:215–220
Psychopathology was assessed by means of the Positive
For analysis on antipsychotics, we stratified patients into
and Negative Syndrome Scale for Schizophrenia (PANSS),
three groups: first generation antipsychotics (FGA), second
[administered by trained psychiatrists.
generation antipsychotics (SGA) and clozapine.
Neuropsychological performances were assessed with
Differences between COMT and STH genotypes and
the following tests, administered by trained psychologists.
demographic and clinical characteristics were analyzed
The Brief Assessment of Cognition in Schizophrenia
with one-way analysis of variance (ANOVA) for quanti-
(BACS), a brief evaluation of the main cognitive functions
tative measures, or v2 test for dichotomic variables (gender
that are usually impaired in schizophrenic patients
and treatment class).
includes the following tasks: verbal memory and learning
Effects of COMT and STH genotypes and their inter-
(list of words), working memory (sequence of numbers),
action on cognitive performances were analyzed by means
motor function (token motor task), speed of processing
of General Linear Model (GLM), with scores of BACS,
(symbol coding), verbal fluency (semantic categories),
WCST and CPT as dependent variables and COMT and
letter fluency, executive function, subcomponent of plan-
STH genotypes as categorical factors. To be more con-
ning (Tower of London).
servative, given the unbalanced groups sizes, we used HSD
The Wisconsin Card Sorting Test (WCST) ] evalu-
Test for Unequal numbers to determine significant differ-
ates visuospatial skills and the ability to classify, keep the
ences between genotypes groups.
set, switch the attentive focus, and inhibit interferinganswers. The score results from the number of categoriescompleted by the patient, a measure of abstract reasoning
and the number of perseverative errors, evaluating morespecifically cognitive flexibility.
DNA analysis showed reliable results for COMT genotype
The Continuous Performance Test (CPT) [a com-
in 339 subjects and for STH genotype in 342 subjects.
puterized test, presenting a sequence of stimuli to be rec-
Genotypes were distributed as follows: 68 Met/Met, 174
ognized ignoring distractors, evaluates sustained and
Met/Val and 97 Val/Val for COMT gene; 214 Q/Q, 113
Q/R and 15 R/R for STH gene. Allelic distributions fol-lowed Hardy–Weinberg equilibrium.
Demographic and clinical characteristics stratified by
COMT and STH genotypes are reported in Table No
STATISTICA Software for Windows, version 8 (StatSoft
significant differences were observed between genotype
Inc., Tulsa, OK, USA) was used to perform statistical
All patients were taking antipsychotic treatments: 129
As in previous works, for analysis on COMT genotype
subjects were on clozapine, 112 on risperidone, 80 on
we grouped patients as Val/Val and Met carriers [], while
haloperidol, 13 on olanzapine, 5 on aripiprazole, 3 on
for STH genotype we grouped patients in Q/Q homozygous
paliperidone and 1 on quetiapine. The v2 test showed no
and R carriers [given the low frequency of the G/G
significant differences in genotypes distribution (COMT
and STH both separately and in interaction) among
Table 1 Demographic and clinical features of the sample, stratified by COMT and STH genotypes
Education (years)
PANSS negative (score)
PANSS positive (score)
PANSS general (score)
PANSS total (score)
years years, SD standard deviation, NS not significant
Neurol Sci (2015) 36:215–220
Table 2 Antipsychotic
F = 3.67, p = 0.056), a significant main effect of STH
COMT*STH genotypes
genotype (g2p = 0.021, F = 6.34, p = 0.01) and a signifi-
cant COMT*STH interaction (g2
p = 0.002). Post-hoc HSD for Unequal numbers showed
that subjects carrying COMT Val/Val genotype and STH R
allele performed worse than both COMT Val/Val and STH
Q/Q carriers (p = 0.019) and COMT Met allele and STH R
carriers (p = 0.046).
Mean scores of neuropsychological performances strat-
ified by COMT and STH genotypes are reported inTable Significant effects of COMT*STH interaction on
FGA first generation antipsychotics, SGA second generation anti-psychotics, SD standard deviation, NS not significant
WCST number of categories are displayed in Fig.
treatment groups (FGA, SGA and clozapine) as shown inTable .
The GLM Analysis with COMT and STH genotypes as
categorical predictors and the score of cognitive tests as
To our knowledge this is the first study evaluating inter-
dependent variables showed significant effects only for
actions between COMT and STH polymorphisms on cog-
Symbol Coding BACS' subtest and WCST number of
nitive functions in a sample of patients with schizophrenia.
Our results confirm previous literature reporting an
Symbol Coding BACS' subtest evaluates selective
effect of COMT genotype on several cognitive measures.
attention and working memory, representing a global
In detail, we observed a significant effect of COMT on
measure of speed of processing. The analysis on symbol
Symbol Coding BACS subtest, with better performances
coding revealed a significant overall model (R2 = 0.036,
among Met carriers and a similar trend on WCST ‘‘number
F = 3.79, p = 0.01), with significant main effect of
of categories''.
COMT genotype (g2p = 0.02, F = 4.93, p = 0.027) and a
Results also revealed a significant main effect of STH
trend of COMT*STH interaction (g2p = 0.011, F = 3.32,
genotype on WCST ‘‘number of categories'', showing the
p = 0.069). Post-hoc HSD for Unequal numbers on COMT
patients carrying the STH R allele performed worse than
main effect showed a significant difference between
Q/Q homozygous, supporting previous findings ].
COMT Met carriers and COMT Val/Val (p = 0.02), the
Moreover, analyses suggest an additive effect of COMT
latter showing worse performances.
and STH polymorphisms. A significant interaction was
The analysis on WCST number of categories completed,
found on WCST number of categories with subjects car-
a measure of abstract thinking, showed a significant overall
rying COMT Val/Val genotype and STH R allele per-
model (R2 = 0.040, F = 4.14, p = 0.007), with a slightly
forming significantly worse than both COMT Val/Val and
significant main effect of COMT genotype (g2p = 0.012,
STH Q/Q carriers and COMT Met allele and STH R
Table 3 Mean scores of neuropsychological tests, stratified by COMT and STH genotypes
Val/Val (mean ± SD)
Met carriers (mean ± SD)
R carriers (mean ± SD)
Correct sequences
WCST cat.comp.
Neurol Sci (2015) 36:215–220
healthy controls and in a group of controls affected byFTLD may be helpful to understand physiologic mecha-nisms underlying cognitive processes. Second, focusing onsingle polymorphisms may be restrictive and we cannotexclude that our results may depend on interaction withdifferent polymorphism or on other unexplored factors,such a downstream effect in the pathway where COMT andSTH are normally involved.
Although explanation of our results is far from clear and
the effect that we observed may depend on a set of inter-acting neurobiological factors, the role of STH genotype oncognitive functions appears to be worthy of further inves-tigation, that might help understanding its neurophysio-logic value.
Fig. 1 Number of categories completed in the Wisconsin CardSorting Test (WCST), stratified by COMT and STH groupedgenotypes. General Linear Model: F = 10.03; p = 0.002
carriers. A trend of interaction between COMT and STH
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„Moleküle der Gefühle„ Neurobiologische Grundlagen der Sucht K. Hentschel Psychologin FSP Psychotherapeutin SPV ECP Körperpsychotherapeutin EABP Manuskript im Rahmen des Seminars vom Herbst 2001 sowie 2002 an der Fachhochschule Zürich, Hochschule für Soziale Arbeit
Chapter 12 The Anisotropy of Metal Oxide Surface Properties G.S. Rohrer Department of Materials Science and Engineering, Carnegie Mellon University,Pittsburgh PA, 15213-3890, U.S.A. The surface properties of metal oxides influence the rates of heterogeneouschemical reactions, the growth of heteroepitaxial films, and the sintering ofparticles during the consolidation of ceramics. Just as certain bulk properties ofcrystalline materials are anisotropic, surface properties also depend onorientation. The dependence of surface properties on orientation can berationalized by recognizing that the atoms on crystallographically distinct facetshave different coordination environments, as illustrated schematically in Fig. 1.This same figure also illustrates that in binary and more complex materials,surfaces with identical orientations can be terminated by different atomic layerswith distinct compositions. Throughout this chapter, we shall take the"character" of a surface to be defined by its orientation, {hkl}, and its atomictermination layer.