Defective neurogenesis and schizophrenia-like behavior in PARP-1-deficient mice

Hong, Seokheon; Yi, Jee Hyun; Lee, Soonje; Park, Chang-Hwan; Ryu, Jong Hoon; Shin, Ki Soon; Kang, Shin Jung

doi:10.1038/s41419-019-2174-0

Download PDF

Article
Open access
Published: 09 December 2019

Defective neurogenesis and schizophrenia-like behavior in PARP-1-deficient mice

Seokheon Hong¹^na1^nAff6,
Jee Hyun Yi²^na1^nAff7,
Soonje Lee²,
Chang-Hwan Park³,
Jong Hoon Ryu⁴,
Ki Soon Shin^2,4 &
…
Shin Jung Kang^1,5

Cell Death & Disease volume 10, Article number: 943 (2019) Cite this article

3823 Accesses
22 Citations
1 Altmetric
Metrics details

Subjects

Abstract

In the current study we present evidence suggesting that PARP-1 regulates neurogenesis and its deficiency may result in schizophrenia-like behavioral deficits in mice. PARP-1 knockout neural stem cells exhibited a marked upregulation of embryonic stem cell phosphatase that can suppress the proliferative signaling of PI3K-Akt and ERK. The suppressed activity of Akt and ERK in the absence of PARP-1 results in the elevation of FOXO1 activity and its downstream target genes p21 and p27, leading to the inhibition of neural stem cell proliferation. Moreover, expression of neurogenic factors and neuronal differentiation were decreased in the PARP-1 knockout neural stem cells whereas glial differentiation was increased. In accordance with the in vitro data, PARP-1 knockout mice exhibited reduced brain weight with enlarged ventricle as well as decreased adult neurogenesis in the hippocampus. Interestingly, PARP-1 knockout mice exhibited schizophrenia-like symptoms such as anxiety, depression, social interaction deficits, cognitive impairments, and prepulse inhibition deficits. Taken together, our results suggest that PARP-1 regulates neurogenesis during development and in adult and its absence may lead to the schizophrenia-like behavioral abnormality in mice.

Messenger RNA transport on lysosomal vesicles maintains axonal mitochondrial homeostasis and prevents axonal degeneration

Article Open access 10 April 2024

Formation of memory assemblies through the DNA-sensing TLR9 pathway

Article Open access 27 March 2024

Control of neuronal excitation–inhibition balance by BMP–SMAD1 signalling

Article Open access 17 April 2024

Introduction

Poly(ADP-ribose) polymerase-1 (PARP-1) is a multifunctional nuclear enzyme that regulates DNA repair, gene expression and cell death by attaching poly(ADP-ribose) (PAR) on many important regulators of these processes¹. When overactivated by massive DNA damage, PARP-1 can induce cell death by depleting NAD⁺². However, PARP-1 can act as a survival factor under tolerable DNA damage condition by detecting and repairing the damage³. PARP-1-deficient cells exhibit higher rate of genomic instability and enhanced susceptibility toward genotoxic insults¹. Thus PARP-1 has been extensively studied as a target for cancer pharmacotherapy⁴. Furthermore, there have been studies suggesting that PARP-1 is involved in the regulation of cell proliferation. Mouse embryonic fibroblasts from the PARP-1 knockout (KO) mice exhibited decreased proliferation⁵. Another study suggested that PARP-1 can regulate cell proliferation by directly repressing FOXO1⁶. There has been a report showing that inhibitors of PARP-1 attenuated the activation of a prosurvival kinase Akt⁷. These studies suggest a possible role of PARP-1 as a pro-proliferative factor.

It has been suggested that a subtype of schizophrenia is a neurodevelopmental disorder^8,9. Defective neurogenesis has been reported in animal models and patients of schizophrenia^9,10,11,12. Specifically, reduction in NSC proliferation, decreased cerebral and hippocampal volume, enlarged ventricle and evidence of defective neuronal migration have been reported^9,10,13. Supporting the neurodevelopmental disorder hypothesis of schizophrenia, a number of susceptibility genes have been identified and many of them are involved in different aspects of neurogenesis^14,15,16,17. Disrupted-in-schizophrenia 1 (DISC1), one of the schizophrenia susceptibility gene, has been shown to regulate NSC proliferation by regulating Akt-glycogen synthase kinase (GSK) 3β signaling^11,12.

Akt1, one of the Akt isoforms, has been independently identified as one of the schizophrenia-associated genes^14,18. Various neuronal signaling pathways induced by growth factors or neurotransmitters like dopamine converge on Akt to regulate cell survival, proliferation, and migration¹⁹. In schizophrenic patients as well as in animal models, Akt level or activity has been shown to be decreased^19,20,21. Consistent with these reports, Akt interacts with many schizophrenia susceptibility gene products such as DISC1, neuregulin1, and dysbindin1¹⁹. In addition, many downstream targets of Akt including GSK3, FOXO1, β-catenin, and mammalian target of rapamycin have been also implicated in the pathogenesis of schizophrenia and other related mental disorders^19,22.

In addition to the possible involvement in the regulation of cell proliferation, PARP-1 has been shown to play a role in embryonic stem cell pluripotency and reprogramming^23,24,25. An earlier study reported that PARP-1 is required for the HES1 function in neural stem cells²⁶. These findings prompted us to hypothesize that PARP-1 may play a role in neural stem cell proliferation and differentiation and its absence may be relevant to the development of psychiatric disorders.

In the present study, we present evidence suggesting that PARP-1 promotes neurogenesis by regulating PI3K, Akt, ERK, and FOXO1 signaling via PARP activity-dependent regulation of embryonic stem cell phosphatase (ESP) expression. PARP-1-deficient mice exhibited reduced brain weight and schizophrenia-related behavioral deficits. Our study suggests PARP-1 as a regulator of neurogenesis and a candidate gene associated with schizophrenia-related mental disorders.

Results

PARP-1-deficient NSCs exhibit defects in proliferation

To examine whether PARP-1 is involved in the regulation of neurogenesis, we first performed neurosphere formation assay using PAPR-1 KO NSCs. As shown in Fig. 1a, PARP-1-deficient NSCs formed neurospheres with decreased number and diameter when compared with the wild-type (WT). Similar results were obtained when PARP-1 was knocked down by siRNA in the WT NSCs (Fig. 1b). The delayed neurosphere formation in the PARP-1 KO NSCs was restored when PARP-1 was overexpressed in the KO NSCs (Fig. 1c). Neurosphere formation was also retarded by PARP-1 inhibitor (Fig. 1d), suggesting PARP-1 enzymatic activity is required for the normal level of NSC proliferation or survival. Furthermore, the KO NSCs exhibited reduced BrdU incorporation, which was restored by PARP-1 reintroduction (Fig. 1e, f). PARP-1 knockdown (Fig. 1g) or inhibition of the enzymatic activity (Fig. 1h) resulted in the similar results. In addition, PARP-1 KO NSCs were more immunoreactive for the cell cycle inhibitor p27 (Fig. 1i) and p21 (Fig. 1j) when compared with the WT, suggesting that proliferation is suppressed in the PARP-1 KO NSCs. Consistently, PARP-1 inhibitor increased the expression of p27 and p21 in the WT NSCs (Fig. 1k), indicating that PARP-1 negatively regulates the expression of these cell cycle inhibitors. Taken together, these results suggest that PARP-1 is required for the normal level of NSC proliferation.

**Fig. 1: PARP-1-deficient embryonic NSCs exhibited defects in proliferation.**

PARP-1 is required for the survival of NSCs

We then examined whether the absence of PARP-1 affects the NSC survival as well. When TUNEL assay was performed to compare the rate of spontaneous apoptosis in cultured NSCs, PARP-1 KO showed more TUNEL-positive cells (Fig. 2a), which was also reversed by reintroduction of PARP-1 (Fig. 2b). PARP-1 knockdown (Fig. 2c) or inhibition by 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinolinone (DPQ) (Fig. 2d) also resulted in the increase of apoptotic cells. In a similar manner as in the cultured NSCs, PARP-1 KO brains exhibited increased number of TUNEL-positive cells at embryonic days 16.5 and 18.5 (Fig. 2e, f). These results suggest that PARP-1 is required for the survival of the NSCs as well as normal level of proliferation.

**Fig. 2: PARP-1 was required for the survival of NSCs.**

PARP-1 negatively regulates FOXO1 activity in NSCs

To understand how PARP-1 regulates NSC proliferation, we then examined FOXO1 activity in PARP-1 KO NSCs. FOXO1 is regulated by phosphorylation and proteasomal degradation: when it is phosphorylated by Akt or ERK, it is localized in the cytoplasm to be degraded²⁷. As shown in Fig. 3a, PARP-1 KO NSCs contained more FOXO1 in the nuclear fraction than the WT. When FOXO1 was overexpressed in the NSCs, the WT cells showed mostly cytoplasmic localization of the exogenous FOXO1 while KO cells retained FOXO1 in the nucleus as well (Fig. 3b). When we overexpressed PARP-1 in the KO NSCs, FOXO1 was now found in the cytoplasm in the PARP-1 expressing cells but not in the PARP-1-deficient cells (Fig. 3c). These results imply that PARP-1 negatively regulates FOXO1 by inducing its cytoplasmic localization. In addition, FOXO1 transcriptional activity was increased in the PARP-1 KO NSCs (Fig. 3d). Consistently, knockdown or inhibition of PARP-1 in the WT NSCs enhanced the FOXO1 activity (Fig. 3e, f). Overexpression of PARP-1 in the KO NSCs, however, suppressed the FOXO1 transcriptional activity (Fig. 3g).

**Fig. 3: PARP-1 negatively regulated FOXO1 activity in the NSCs.**

Then we examined the phosphorylation status of FOXO1 in the PARP-1 KO cells. Figure 3h shows that FOXO1 phosphorylation was much reduced in the PARP-1-deficient NSCs consistently with the FOXO1 localization and activity data. Moreover, phosphorylation of upstream kinases including Akt and ERK was reduced in the PARP-1 KO cells (Fig. 3h). When NSCs were incubated with the inhibitors of Akt (MK2206) or ERK (U0126), neurosphere diameters were reduced to the level when PARP-1 was absent or inhibited by DPQ (Fig. 3i). Importantly, activators of Akt (SC-79) or ERK (C6 ceramide) reversed the decrease in the diameter of the PARP-1 KO neurospheres (Fig. 3j). Taken together, these results suggest that PARP-1 is required for the suppression of FOXO1 activity and activation of Akt and ERK.

PARP-1 negatively regulates the expression of embryonic stem cell phosphatase

To understand the mechanism how PARP-1 regulates NSC proliferation, we examined the changes in the gene expression profile between the WT and KO NSCs by microarray analysis. A hierarchical clustering revealed that 17,549 genes were changed more than two-folds (Fig. S1A). We focused our attention on phosphatases that may suppress Akt signaling. Interestingly, many receptor type-protein tyrosine phosphatases were upregulated in the PARP-1 KO NSCs (Fig. S1B). Among those, the expression of embryonic stem cell phosphatase (ESP, also known as protein tyrosine phosphatase receptor type V) was increased more than 40-fold in the KO NSCs (Fig. S1B).

A previous study reported that ESP is a direct target of p53 and mediates p53-induced cell cycle arrest, implying that ESP is an inhibitor of cell proliferation^28,29. However, it has not been studied whether ESP is involved in the regulation of proliferation or differentiation of the stem cells. To examine the possible involvement of ESP in the PARP-1-regulated NSC proliferation, we first confirmed the upregulation of ESP in the PARP-1 KO NSCs. An RT-PCR analysis revealed that mRNA level of ESP was markedly increased in the PARP-1-deficient NSCs (Fig. 4a). Consistently, the activity of ESP promoter was significantly increased in the KO cells (Fig. 4b). Reintroduction of PARP-1 in the KO NSCs suppressed the ESP promoter activity very efficiently (Fig. 4c). Conversely, addition of PARP-1 inhibitor DPQ enhanced the ESP promoter activity (Fig. 4d) and increased the mRNA level of ESP (Fig. 4e) in the WT NSCs. These results indicate that PARP-1 negatively regulates the transcription of ESP.

**Fig. 4: PARP-1 negatively regulated the expression of ESP.**

To address whether the decreased proliferation of PARP-1 KO NSCs is due to the ESP upregulation, we then knocked down the expression of ESP in the PARP-1 KO NSCs and monitored the neurosphere formation. As shown in Fig. 4f, g, knockdown of ESP increased the diameter of PARP-1 KO neurospheres. Consistently, the rate of proliferation as assessed by BrdU incorporation was also restored following ESP knockdown in the PARP-1 KO NSCs (Fig. 4h).

We then examined whether the increase in ESP expression is responsible for the decrease in Akt or ERK activation in the PARP-1-KO NSCs. As shown in Fig. 4i, j, the ESP knockdown resulted in the increase of Akt and ERK phosphorylation suggesting that the forced suppression of ESP expression in the PARP-1-deficient cells restored the activity of Akt and ERK. Because ESP is a receptor type tyrosine phosphatase³⁰ and Akt or ERK is activated by serine/threonine phosphorylation, we hypothesized that ESP may inhibit upstream kinase activated by tyrosine phosphorylation. Thus we examined whether PI3K is involved. As expected, activation of PI3K was much suppressed in the PARP-1 KO NSCs and knockdown of ESP enhanced the activation of PI3K (Fig. 4i, j). Consistently, expression of p21 and p27 was also reduced by ESP knockdown (Fig. 4i, j). Taken together, these results suggest that PARP-1 maintains the normal level of PI3K/Akt-ERK activity by repressing the expression of ESP, a suppressor of PI3K signaling.

PARP-1 is required for the normal level of neuronal differentiation of the NSCs

A previous study reported that PARP-1 deletion promotes postnatal subventricular zone (SVZ) NSC differentiation into oligodendrocytes³¹. Thus we further examined whether PARP-1 can regulate the differentiation of NSCs. The immunostaining analysis revealed that the number of doublecortin (DCX)- or microtubule-associated protein 2 (MAP2)-positive cells was decreased by ~50% in the PARP-1 KO cells (Fig. 5a, b). The ratio of MAP2-positive cells was restored after overexpression of PARP-1 in the KO NSCs (Fig. 5b). The number of cells expressing neuronal markers was also decreased after PARP-1 knockdown (Fig. 5c) or pharmacological inhibition (Fig. 5d, e). To further confirm whether PARP-1 functions in the neuronal differentiation, we examined the changes in the neurogenic transcription factors in the KO NSCs by RT-PCR. Consistently with the decreased neurogenesis, the mRNA levels of neurogenic factors such as achaete-scute homolog 1 (ASCL1) and neurogenin 2 were decreased in the PARP-1 KO NSCs (Fig. 5f-h).

**Fig. 5: PARP-1 was required for the normal level of neuronal differentiation of the NSCs.**

We then investigated whether PARP-1 affects the glial differentiation. As shown in Fig. 5i, j, the PARP-1 KO cells exhibited increased number of astrocyte marker glial fibrillary acidic protein (GFAP)- or oligodendrocyte marker Olig2-positive cells under differentiation condition. Consistently, when we examined the expression of nestin, Tbr2 (an intermediate neural progenitor marker) and Olig2 in embryonic day 16.5 brains, we observed a similar tendency as in cultured NSCs, i.e., decreased neurogenesis and increased oligodendrogenesis in PARP-1 KO (Fig. S2). These results suggest that PARP-1 is required for the normal level of neurogenesis.

PARP-1 KO mice exhibited reduced brain weight and decreased proliferation of adult NSCs

To further investigate whether PARP-1 is required for normal brain development, we examined the cross-sectional area of ventricle and the brain weights. As shown in Fig. 6a, ventricle area over total coronal cross-section area was significantly increased in the PARP-1 KO brains at embryonic day 14.5. Furthermore, the KO mice exhibited reduced brain weights throughout the early postnatal period and adulthood (Fig. 6b). When we examined anatomical structures of the adult hippocampus and the cortex by NeuN and GFAP immunohistochemistry, we could not find any noticeable difference between WT and KO (Fig. S3). However, there was a tendency of decrease of NeuN-positive neurons in the cortex of the PARP-1 KO mice although it did not reach statistical significance (Fig. S3).

Then we examined whether PARP-1 regulates proliferation of NSC during adult stage as well. The number of BrdU-positive cells in the adult hippocampal dentate gyrus was less abundant in PARP-1 KO mice (Fig. 6c). Furthermore, PARP-1 KO mice exhibited a significantly increased number of p27-positive cells in the hippocampal subgranular zone (SGZ) (Fig. 6d). Consistently, the decreased number of Ki67-positive cells was observed in the hippocampus of the PARP-1 KO (Fig. S4A). The number of positive cells for a NSC marker, SOX2, was also decreased in the PARP-1 KO (Fig. S4B). The decreased proliferation of NSCs in the absence of PARP-1 may lead to decreased adult neurogenesis: NeuroD1- or DCX-positive cells were also decreased in the hippocampus of the PARP-1 KO (Fig. S5). We obtained a consistent result in the neurosphere formation assay using adult hippocampal NSCs. As in the embryonic stage (Fig. 1a), adult hippocampal NSCs prepared from SVZ or SGZ of the PARP-1 KOs formed much smaller neurospheres (Fig. 6e, f), suggesting PARP-1 is necessary for the normal level of proliferation in adult NSCs.

Behavioral deficits in PARP-1 KO mice

In order to assess whether PARP-1 KO mice present behavioral alterations, we subjected them to a battery of cognitive and emotional tests. We found that PARP-1 KO mice display emotional and cognitive deficits associated with schizophrenia-like behaviors. The open field test was used to examine the locomotor/exploratory and anxiety-related behaviors. The time spent in the center area was significantly longer in PARP-1 KO mice compared to WT mice (Fig. 7a1). However, no significant change in the total moving distance was detected (Fig. 7a2), suggesting the higher anxiety of PARP-1 KO mice without any changes in locomotor activity. Consistently, the elevated plus maze test also showed that PARP-1 KO mice exhibited high anxiety, i.e., decrease in open arm duration (Fig. 7b1) and open arm entries (Fig. 7b2). Furthermore, PARP-1 KO mice showed deficient social interaction (Fig. 7c) and depression-like behavior as judged by the increased immobility in forced swim test (Fig. 7d).

**Fig. 7: PARP-1 KO mice exhibited schizophrenia-like behavioral deficits.**

For testing the cognitive capability of PARP-1 KO mice, Y-maze spontaneous alternation and novel object recognition tests were performed. PARP-1 KO mice exhibited impaired long-term recognition memory in addition to impaired spatial working memory. The Y-maze test revealed impaired spatial working memory in PARP-1 KO mice (Fig. 7e). Moreover, PARP-1 KO mice showed little preference for the novel object (Fig. 7f).

A sensorymotor gating deficit, as measured by the prepulse inhibition of the startle response is used as a clinical measure of schizophrenia or anxiety disorder. As shown in Fig. 7g, PARP-1 KO mice exhibited a significant PPI deficit at multiple intensities of prepulse stimuli. Intriguingly, we found that PPI deficit in PARP-1 KO animals was restored by haloperidol, a blocker of dopamine D₂ receptor (Fig. S6). Therefore, the altered neurodevelopment caused by PARP-1 deficiency may result in the dopaminergic hyperactivity, which produces, albeit partly, schizophrenia-like behaviors in PARP-1 KO mice. General health as assessed by moving velocity and skeletal muscle strength was not impaired in the PARP-1 KO mice (Fig. S7).

Discussion

In the present study, we present evidence that PARP-1 regulates proliferation and differentiation of NSCs and its absence results in defective neurogenesis and behavioral deficits reminiscent of schizophrenia in mice. It has been suggested that neurodevelopmental defects can be a cause of psychiatric disorders including schizophrenia^32,33. Earlier studies suggested that ventricle enlargement in the schizophrenic patients is the evidence that links defective neurodevelopment and schizophrenia^34,35. In addition, decrease in cortical gray matter in the patients' brain has been reported thereafter³⁶. Recent studies using mice transgenic or knockout for the genes associated with schizophrenia have further supported the neurodevelopmental hypothesis of schizophrenia. Most extensively studied are the DISC1 transgenic mice³⁷. DISC1 was identified as one of the schizophrenia-associated genes and found to be disrupted by chromosomal translocation, truncated or point-mutated in patients with schizophrenia³⁸. Depending on the interacting partners³⁹, DISC1 activity regulates distinct signaling pathways. Through the interaction with KIAA1212, DISC1 inhibits Akt activity, which in turn regulates differentiation of postmitotic newborn neurons¹². In NSCs, instead, DISC1 regulates proliferation through inhibition of GSK3β, a downstream target of Akt¹¹. Accordingly, DISC1 and Dixdc1 interact to regulate NSC proliferation by modulating Akt-GSK3β signaling⁴⁰. Therefore, DISC1 functions in the regulation of NSC proliferation, neuronal differentiation, and neuronal migration during brain development^{11,41,42,43,44}.

The regulation of NSC proliferation by PARP-1 turned out to be mediated by Akt and ERK signaling converging on FOXO1. Apart from the involvement in the schizophrenia pathogenesis downstream of DISC1, Akt has been independently suggested as a schizophrenia susceptibility gene in the genetic linkage and association studies¹⁹. In accordance with this, the protein levels and activity of Akt decreased in the schizophrenic patients^19,20. In our observation, Akt activity was markedly suppressed in the absence of PARP-1 and pharmacological activator of Akt restored the cell proliferation defect in the PARP-1 KO NSCs. Our results further support the involvement of Akt signaling in neurodevelopmental defects associated with schizophrenia.

As a mechanism behind the lowered Akt activity in the absence of PARP-1, we found that the expression of ESP, a receptor type protein tyrosine phosphatase, was strikingly elevated in the PARP-1 KO NSCs. ESP has been considered as a tumor suppressor candidate since it mediates the p53-induced cell cycle exit^29,30. We found that PARP-1 negatively regulates the transcription of ESP via PARP enzymatic activity. As to the mechanism of PARP-1-mediated ESP repression, one possibility is that PARP-1 suppresses the transcription of ESP by inhibiting p53 activity. A recent study suggested that a PARP-1 inhibitor activates p53 by ATM/ATR-mediated phosphorylation in NSCs⁴⁵. Furthermore, ESP is known to be a direct target gene of p53²⁹. Therefore, it is highly possible that PARP-1 represses the transcription of ESP via p53 regulation. However, it cannot be ruled out that PARP-1 inhibits the activity of essential transcription factors of the ESP by direct poly ADP-ribose (PAR) modification.

The role of PARP-1 was extended to the regulation of NSC differentiation as well: the rate of neuronal differentiation was decreased while that of astrocytic and oligodendrocytic differentiation was increased in the absence of PARP-1 in the cultured NSCs. Plane and colleagues previously reported that the percentage of oligodendrocyte progenitor cells (OPCs) increased while that of neuroblasts decreased in the SVZ of postnatal day 11 PARP-1 KO mice³¹. In spite of the increased number of OPCs, the layer of mature and myelinating oligodendrocytes in corpus callosum of PARP-1 KOs was thinner than that of WT³¹. They suggested that the increase of OPCs may be a compensatory mechanism for the myelination deficiency. We also observed the increase in the percentage of glial differentiation in the embryonic NSCs. However, oligodendrocytic differentiation was increased in the absence of PARP-1 even in the embryonic NSCs in culture irrespective of myelination in our observation. Our data indicate that PARP-1 actively regulates neuronal differentiation of NSCs: Basic helix-loop-helix transcription factors required for the neuronal differentiation were downregulated in the PARP-1 KO NSCs. Specifically, expression of ASCL1 and neurogenin 2 was significantly suppressed in the PARP-1 KO NSCs (Fig. 5). However, expression of oligodendrogenic transcription factors was not much altered in the PARP-1 KO NSCs: fold-changes of Olig 1 and Olig2 expression in the KO were 1.25 and 1.114 in our microarray analysis, respectively. Therefore it can be postulated that the increased gliogenesis may be due to decreased neurogenesis. Previously, it has been reported that PARP-1 is complexed with TLE to repress the transcription of ASCL1 but upon activation by calcium signaling, it derepresses ASCL1 transcription by PARylating and driving off TLE²⁶. Our results indicate that PARP-1 regulates the expression of not only a single neurogenic factor following calcium signaling but also multiple neurogenic factors even before the differentiation stage.

PARP-1 KO mice showed neurodevelopmental and behavioral deficits very similar with the phenotypes reported in the patients and the mouse models of schizophrenia. We found that PARP-1 KO mice exhibited enlarged ventricle during development and reduced brain weight in embryos and adults. Our results suggest that the reduced brain mass may result from the decreased neurogenesis of the NSCs. Interestingly, no remarkable structural difference was found in the hippocampus and the somatosensory cortex of the adult PARP-1 KO mice although there is a tendency of decrease in the cortical NeuN-positive neurons in the PARP-1 KO. Therefore, more detailed characterization of the regional structural difference of the brain between WT and PARP-1 KO mice is needed to fully understand the neurodevelopmental defect associated with schizophrenia-like behaviors in the PARP-1 KO mice.

In conclusion, we found that PARP-1 regulates the proliferation and differentiation of NSCs by orchestrating the expression of key regulators of neurogenesis. The defective neurogenesis in the absence of PARP-1 during development and throughout the adulthood may be a cause of multiple behavioral abnormalities found in schizophrenia including anxiety, depression and deficits in memory, social interaction, and PPI.

Materials and methods

Animals

Animal maintenance and treatment were performed in accordance with the Animal Care and Use Guidelines issued by Kyung Hee University and Sejong University. All experiments with mice were carried out according to the protocols approved by the Institutional Animal Care and Use Committees of Kyung Hee University (approved protocol No. KHU(SE)-13-031, KHU(SE)-15-026) and Sejong University (approved protocol No. SJ-20120901-E2). PARP-1 KO mice (129S-PARP1^tm1Zqw, Jackson Laboratory) were backcrossed onto C57BL/6J strain more than eight times. Matched littermates of PARP-1 KO and WT mice were analyzed. Mice were group-housed on a 12 h:12 h light:dark cycle and had free access to food and water. The animals were held in a chamber at 20–24 °C with 30–60% humidity.

Cell culture and sphere formation assay

Embryonic NSCs were cultured from E13.5 C57BL/6J or PARP-1 mice cerebrocortex. Briefly, the neocortices of mouse embryos on embryonic day 13.5 were dissected, cut into small pieces and mechanically triturated in cold PBS. The dissociated cells were collected by centrifugation for 5 min at 1000 × g and resuspended in Dulbecco's Modified Eagle's Medium (DMEM): F12 (1:1) medium (Gibco) supplemented with 2% B-27 (Gibco), 20 ng/mL epidermal growth factor (EGF) and 20 ng/mL basic fibroblast growth factor (FGF) (R&D systems). Cells were plated on untreated petri dishes in the culture medium and incubated with 5% CO₂ at 37 °C. The culture medium was changed every 3−4 days. After 5−7 days, the cells were mechanically dissociated and replated in a new culture flask at a density of 1 × 10⁵ cells/mL with fresh culture medium. Adult NSCs were isolated from 8–12 week-old mouse SVZ or SGZ. For the sphere formation assay, primary cultured cells or serially passaged cells were resuspended with DMEM: F12 (1:1) and the number of viable cells was counted by trypan blue exclusion assay in a hemocytometer (Marienfeld). Cells were plated onto uncoated 96 well-plate at a density of 3 × 10³ cells/well in the growth medium. The cells were incubated with 5% CO₂ at 37 °C. Three to five days after seeding, the number of spheroids and their diameters were measured under a microscope. For embryonic NSC cultures, NSCs from the brain of an individual littermate embryo were cultured separately and then genotyped. After genotyping, cells from 2–3 embryos of the same genotype were pooled for further experiments. For adult NSC cultures, cells from at least three brains of the same genotype were pooled. For the experiments using cultured NSCs, cultures were randomly assigned to the treatments and data points were pooled from 2–4 independent experiments.

Retroviral infection and siRNA transfection

For retroviral infection, 10⁴ cells were incubated with viral suspension at a volume of 3% of the plating media. One microliter of the viral suspension contained 1 × 10⁴ viral particles. Three days after the infection, infection was confirmed by GFP expression. Human PARP-1 siRNA (5′-CUCUCAAAUCGCUUUUACA-3′), mouse PARP-1 siRNA (5′-GGACCGAAUAUUCCCUCCA-3′) and negative control siRNA were purchased from Bioneer. siRNA (50–150 pmol) was delivered using the Lipofectamine 2000 or LTX with Plus (Life Technologies) according to the manufacturer's protocol.

Antibodies

The following antibodies were used: mouse monoclonal anti-PARP-1, mouse monoclonal anti-BrdU (#347580), mouse monoclonal anti-p21 (#556431), mouse monoclonal anti-p27 (#610241), rabbit polyclonal anti-PAR (#551813,; BD Bioscience), mouse monoclonal anti-α-tubulin (#T5168, Sigma-Aldrich), mouse monoclonal antibodies for Myc (#G019), HA (#G036), Flag (#G191), and GFP (#G096, Abm), rabbit polyclonal anti-MAP2 (#MAB3418), anti-Olig2 (#ab9610), anti-SOX2 (#ab5603, Millipore), anti-GFAP (#ab7260), anti-Ki67 (#ab15580), anti-Tbr2 (#ab183991) and mouse monoclonal anti-Nestin (#ab22035, abcam), goat polyclonal anti-DCX (#sc-8066), anti-NeuroD (#sc-1084), rabbit polyclonal anti-ERK (#sc-93), mouse monoclonal anti-pERK (#sc-7383), anti-LaminB1 (#sc-56145, Santa Cruz), rabbit polyclonal anti-Akt (#4060), rabbit polyclonal anti-pAkt (#4061), rabbit polyclonal anti-PI3K (#4228), anti-pPI3K (#4257), rabbit polyclonal anti-FOXO1 (#2880), rabbit polyclonal anti-pFOXO1 antibody (#9461, Cell Signaling).

Terminal deoxynucleotidyl transferase dUTP nick end labeling assay

To detect apoptotic cells, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was performed with ApopTag Fluorescein In Situ Apoptosis Detection Kit (Millipore) according to the manufacturer's protocol.

Luciferase assay

To measure FOXO1 activity or ESP promoter activity, NSCs cells were transfected with expression vectors encoding PARP-1 or siPARP-1, along with the 6XDBE- or ESP-luciferase reporter vector (kindly provided by Dr. Gerard Karsenty, Columbia University, USA) and control pRL-TK plasmids. When required, the cells were incubated with 50 μM of DPQ for 16 h prior to analysis. Dual luciferase activity assay was carried out using dual luciferase reporter assay kit (Promega) according to the manufacturer’s protocol.

Subcellular fractionation

Cells (5 ×10⁶) were incubated in the cytosolic fractionation buffer (10 mM HEPES, 50 mM NaCl, 0.1 mM EDTA, 0.5 M Sucrose, 0.3% Triton X-100, 1 mM DTT, 1 mM PMSF, 10 μg/ml Leupeptin/Aprotinin, 5 mM NaF, 1 mM Na₃VO₄, 500 nM ADP-HPD, pH 7.9) on ice for 20 min with agitation. The lysates were then centrifuged at 1000 × g for 10 min at 4 °C and the supernatant was kept as a cytosolic fraction. The pellets were washed three times by resuspension in the cytosolic fractionation buffer and centrifugation. The resulting pellets were resuspended in high salt buffer (5 mM HEPES, 1.5 mM MgCl₂, 0.2 mM EDTA, 0.5 mM DTT, 150 mM KCl, 300 mM NaCl, 26% glycerol (v/v), 1 mM PMSF, 10 μg/ml Leupeptin/Aprotinin, 5 mM NaF, 1 mM Na3VO4, 500 nM ADP-HPD, pH 7.9) and then centrifuged at 13,000 × g for 10 min at 4 °C and used as heavy membrane fraction.

Immunoblotting

Cell lysates were prepared and boiled for 5 min at 94 °C in 2 × SDS sample buffer (0.25 M Tris-HCl pH 6.8, 2% SDS, 10% 2-mercaptoethanol, 30% glycerol, 0.01% bromophenol blue). Protein samples were separated by 8−12% SDS-polyacrylamide gel electrophoresis and immunoblotting was performed by conventional methods.

Reverse transcription polymerase chain reaction

Total RNA was extracted using RNeasy Mini Kit (QIAGEN) according to the manufacturer`s instruction. To synthesize first strand cDNA, 1 μg of total RNA was incubated at 70 °C for 5 min with 0.5 μg of oligodT and deionized water (up to 15 μl). The reverse transcription reaction was performed using 200 units of M-MLV reverse transcriptase (Promega) in 5× reaction buffer (250 mmol/l Tris-HCl; pH 8.3, 375 mM KCl, 15 mM MgCl₂, 50 mM DTT), 28 units of RNasin inhibitor, and 2.5 mM dNTP mixtures at 42 °C for 90 min. The primers used were; β-actin forward: 5′-TCA CCC ACA CTG TGC CCA TCT ACG AG-3, reverse: 5′-GTG GTG AAG CTG TAG CCA CGC TC-3′; PARP-1 forward: 5′-CTC GGA GAG GCT TTA TCG AGT-3′, reverse: 5′-GGA CTT GGC GTA CTC CGC TA-3′; ESP forward: 5′- GGA GCG CTC ATT TTG TCT TCC AGG TC-3′, reverse: 5′-AAG TAG TGC ACA CCA GGG TAA CCG C-3′; ASCL1 forward: 5′-ACT TGA ACT CTA TGG CGG GTT CTC CG-3′, reverse: 5′-CTT CCA AAG TCC ATT CCC AGG AGA GC-3′; neurogenin2 forward: 5′-AGA GGT GGC CCT TGC AAT CCC CTC-3′, reverse: 5′-CAC ACG CCA TAG TCC TCT TTG ACC ATA AA-3′. A final volume was 25 μl and 2 μl of the cDNA products was used to perform each PCR analysis.

RNA microarray

Total RNA was extracted from PARP-1 littermates E13.5 NSCs using RNeasy Mini Kit (QIAGEN) according to the manufacturer`s instruction. Microarray analysis was performed using the Mouse GE 4x44K v2 Microarray Kit (Agilent) by eBiogen (commercial service). For the each RNA, the synthesis of target cRNA probes and hybridization were performed using Agilent’s LowInput QuickAmp Labeling Kit (Agilent Technologies) according to the manufacturer’s instructions. The hybridization images were analyzed by Agilent DNA microarray Scanner (Agilent Technologies) and the data quantification was performed using Agilent Feature Extraction software 10.7 (Agilent Technologies). The average fluorescence intensity for each spot was calculated and local background was subtracted. All data normalization and selection of fold-changed genes were performed using GeneSpringGX 7.3.1 (Agilent Technologies). Functional annotation of genes was performed according to Gene OntologyTM Consortium (http://www.geneontology.org/index.shtml) by GeneSpringGX 7.3.1.

BrdU labeling

For the labeling of cultured NSCs, cells were plated onto 24 well-plate at a density of 2 × 10⁴ cells/well with fresh growth medium. Before fixation, cells were incubated in the presence of 10 μM BrdU for 15–30 min. For the in vivo labeling, BrdU (50 mg/kg) was administered intraperitoneally to adult mice two times a day for 2 consecutive days. Mice were perfused to verify stem cell proliferation 24 h after the last BrdU injection. The brain slices for BrdU staining were permeablized in 0.5% Triton X-100 for 20 min. After permeabilization, the slices were exposed to 1 N HCl at 37 °C for 30 min. The slices were then preincubated with 5% normal donkey serum. Subsequently, the slices were incubated overnight with rat anti-BrdU antibody (1:500).

Immunostaining

Brain slices (30 μm thick) were permeabilized in 0.5% Triton X-100 for 20 min and blocked in 5% normal serum in PBS for 1 h 30 min in free floating condition. Primary antibodies were incubated for overnight in 3% normal donkey serum and 0.3% triton X-100 in PBS at 4 °C containing primary antibody. For visualization of primary antibodies, slices were incubated Alexa488 or Alexa594 anti-mouse (#A21042 or #A32742), anti-rabbit (#A11070 or #A32740), and anti-goat (#A11055 or #A11058) secondary antibodies (ThermoFisher) for 40 min. For the quantification of antibody-labeled cells in the embryonic brain sections, nonspecific signals on endothelium were excluded from the countings. Diaminobenzidine staining was used for stereological quantification of labeled cells of adult mouse brain using ABC kit according to the manufacturer’s protocol (Vector). Every seventh section (210 μm apart) were used for the counting. Stained cells were counted throughout the rostrocaudal extent of the brain (from bregma −1.58 to −2.54). Resulting numbers were multiplied by 7 to obtain the estimated total number of stained cells per a mouse.

Nissl staining

Brain sections (10 μm thick) were mounted onto glass slides in PBS and dried overnight. For Nissl staining, slides were immersed in 0.025% cresyl violet in 90 mM acetic acid, 10 mM sodium acetate for 30 min. The stained samples were serially dehydrated in ascending concentrations of ethanol and then mounted with VectaMount permanent medium (Vector Laboratories).

Measurement for ventricle area

Coronal cross-section images of Nissl-stained embryonic brains were used for quantification analysis using ImageJ program (US National Institute of Health). Embryonic brains were snap-frozen in OCT medium and coronal sections at the same sectional distance were collected from each brain and labeled accordingly. The matching brain sections from rostral to caudal levels were confirmed by examination under a microscope following Nissl staining. Total brain area or ventricle area was calculated by the measure function of imageJ software.

Behavioral tests

WT and PARP-1 KO male mice (12–16 weeks) were randomly assigned to open field, elevated plus maze (EPM), social interaction, forced swim, Y-maze, novel object recognition, pre-pulse inhibition (PPI) and inverted grid tests.

Open Field test

Open field test was conducted in a novel open box (40 × 40 × 30 cm) under a dim light condition (40 lx). Animals were transported to the experimental room and left uninterrupted for 10 min before the experiment. Animals were placed in the center (20 × 20 cm) of a novel open field arena and both duration of time that animals spent at the center and frequency that animals visited the center were recorded. EthoVision 3.0 software (Noldus) was used to record and analyze the movement of the mice.

EPM test

EPM was comprised of two open arms (30 × 5 × 2 cm) and two closed arms (30 × 5 × 30 cm) that extended from center area (10 × 10 cm). The maze was elevated 50 cm above the floor. The level of anxiety was assessed by the percentage of time spent in the open arms and number of entries in the open arms.

Social interaction test

The social interaction test was conducted in the same arena used for the open field test box. A cylinder was placed at the center of the open box. Animals were placed around the cylinder and were allowed to explore for 5 min. Next day, the mice were relocated to the around of the cylinder in which a novel stranger (Non-experiment mice) was placed. The time that animals were approaching, sniffing, kicking and staring were recorded.

Forced swim test

Animals were put in an open glass cylinder (diameter, 15 cm; height, 25 cm) filled with room temperature water to a depth of 15 cm. The immobility times were measured during a 5-min test. A mouse was considered to be immobile when it ceased struggling to escape and remained floating motionless in the water. Water was replaced between every trial.

Y-maze test

The Y-maze is composed of three identical arms placed at 120 degrees with respect to each other. Each arm was 40 cm long and 12 cm height, 3 cm wide at the bottom and 10 cm wide at the top and converged at an equilateral triangle center area. Each mouse positioned at end of the arm and allowed to explore the Y-maze freely for 12 min. An alternation was defined as the entry into all three arms on consecutive choice. Percent alternations were calculated using the formula: 100 × Total number of alternations/(Total number of arm entries – 2).

Novel object recognition test

The Novel object recognition training took place in the same arena used for the open field test. The training was conducted by placing an individual animal in the box, in which objects A and B were positioned in two adjacent corner 10 cm from the walls. The animal was left to explore the objects for 5 min. The animal was returned 24 h after training to the box where one of the original objects has been replaced by a new object C and allowed to explore the objects freely for 5 min. The amount of time that the animals spent exploring each object was measured. A recognition index calculated for each animal was expressed by the ratio TC/(TB + TC) (TB = time spent exploring the familiar object B, TC = time spent exploring the novel object C).

PPI test

PPI of acoustic startle response was measured with SR-LAB startle chambers (San Diego Instruments, San Diego, CA). An animal was allowed 15-min habituation to the apparatus with a continuous background noise of 70 dB and then exposed to the various acoustic stimuli. All PPI test sessions consisted of startle and prepulse trials. The startle trial consisted of a 40-ms 120-dB startle pulse of broad-band noise. Prepulse trials consisted of a 20-ms noise prepulse, 80-ms delay, and then a 40-ms 120-dB startle pulse. The prepulse intensities were 72, 74, 76, and 80 dB (i.e., 2, 4, 6, and 10 dB above the 70-dB background noise). A test session consisted of six trial types (i.e., two types for startle trial and in between four types for prepulse trials were presented in a pseudo-random order and the average interval between the trials was 15 s (range: 12–30 s). A background noise level of 70 dB was presented throughout the test session. The startle response was recorded for 65 ms at 1-ms intervals starting from the startle stimulus onset, and the maximum startle amplitude was used as the dependent variable. The PPI for each prepulse trial was defined as 100 - {[(startle amplitude for prepulse trials)/(startle amplitude for startle trials)] × 100}.

Inverted grid test

Mice were placed on 1 cm²-spaced metal grid and then the grid was slowly inverted 35 cm above the ground covered with soft bedding. Then the time for the mouse to fall onto the ground was measured within 4 min. Mice were given two times of practice 5 min before the test. Each mouse was tested three times with a rest interval of 2 min between each trial and falls within 10 s were not included⁴⁶.

Statistics

For the statistical analysis of in vitro data, all the experiments were repeated at least three times unless stated otherwise and the results were expressed as mean ± SD. The results of behavioral tests were expressed as mean ± SEM. No statistical methods were applied to predetermine sample sizes. However, our sample sizes are similar to those reported in previous studies for the cell samples and animal numbers. Experimenters were not blinded during data acquisition, but analyses were performed blind to genotype and experimental group. No data were excluded from the study. Data were compared using two-tailed unpaired t-test, Mann–Whitney test, Kruskal–Wallis test, one-way ANOVA and two-way repeated measures ANOVA, where appropriate. Normality of data distribution was tested by D’Agostino and Pearson omnibus normality test. Normal distributions were compared using two-tailed unpaired t-test and ANOVAs with Bonferroni post hoc comparison. Non-normal distributions were compared using Mann–Whitney test and Kruskal–Wallis test with Dunn’s post hoc comparisons. All data were plotted and analyzed using Prism 6.0 (GraphPad Software). Statistical significance was defined at level of p < 0.05.

References

Bai, P. Biology of poly(ADP-Ribose) polymerases: the factotums of cell maintenance. Mol. Cell 58, 947–958 (2015).
Article CAS PubMed Google Scholar
Fouquerel, E. & Sobol, R. W. ARTD1 (PARP1) activation and NAD(+) in DNA repair and cell death. DNA Repair 23, 27–32 (2014).
Article CAS PubMed Google Scholar
Dantzer, F. et al. Poly(ADP-ribose) polymerase-1 activation during DNA damage and repair. Methods Enzymol. 409, 493–510 (2006).
Article CAS PubMed Google Scholar
Davar, D., Beumer, J. H., Hamieh, L. & Tawbi, H. Role of PARP inhibitors in cancer biology and therapy. Curr. Medicinal Chem. 19, 3907–3921 (2012).
Article CAS Google Scholar
Wang, Z. Q. et al. Mice lacking ADPRT and poly(ADP-ribosyl)ation develop normally but are susceptible to skin disease. Genes Dev. 9, 509–520 (1995).
Article CAS PubMed Google Scholar
Sakamaki, J., Daitoku, H., Yoshimochi, K., Miwa, M. & Fukamizu, A. Regulation of FOXO1-mediated transcription and cell proliferation by PARP-1. Biochem. Biophys. Res. Commun. 382, 497–502 (2009).
Article CAS PubMed Google Scholar
Wang, X. et al. Essential role of cell cycle regulatory genes p21 and p27 expression in inhibition of breast cancer cells by arsenic trioxide. Med. Oncol. 28, 1225–1254 (2011).
Article CAS PubMed Google Scholar
Rapoport, J. L., Addington, A. M., Frangou, S. & Psych, M. R. The neurodevelopmental model of schizophrenia: update 2005. Mol. Psychiatry 10, 434–449 (2005).
Article CAS PubMed Google Scholar
Muraki, K. & Tanigaki, K. Neuronal migration abnormalities and its possible implications for schizophrenia. Front. Neurosci. 9, 74 (2015).
Article PubMed PubMed Central Google Scholar
Allen, K. M., Fung, S. J. & Weickert, C. S. Cell proliferation is reduced in the hippocampus in schizophrenia. Aust. N.Z. J. Psychiatry 50, 473–480 (2016).
Article PubMed Google Scholar
Mao, Y. et al. Disrupted in schizophrenia 1 regulates neuronal progenitor proliferation via modulation of GSK3beta/beta-catenin signaling. Cell 136, 1017–1031 (2009).
Article CAS PubMed PubMed Central Google Scholar
Kim, J. Y. et al. DISC1 regulates new neuron development in the adult brain via modulation of AKT-mTOR signaling through KIAA1212. Neuron 63, 761–773 (2009).
Article CAS PubMed PubMed Central Google Scholar
Adriano, F., Caltagirone, C. & Spalletta, G. Hippocampal volume reduction in first-episode and chronic schizophrenia: a review and meta-analysis. Neuroscientist 18, 180–200 (2012).
Article PubMed Google Scholar
Sun, J., Kuo, P. H., Riley, B. P., Kendler, K. S. & Zhao, Z. Candidate genes for schizophrenia: a survey of association studies and gene ranking. Am. J. Med. Genet. B 147B, 1173–1181 (2008).
Article Google Scholar
Nieratschker, V., Nothen, M. M. & Rietschel, M. New genetic findings in schizophrenia: is there still room for the dopamine hypothesis of schizophrenia? Front. Behav. Neurosci. 4, 23 (2010).
PubMed PubMed Central Google Scholar
Shaffer, L. G. et al. The discovery of microdeletion syndromes in the post-genomic era: review of the methodology and characterization of a new 1q41q42 microdeletion syndrome. Genet. Med. 9, 607–616 (2007).
Article CAS PubMed Google Scholar
Wang, S. et al. DISC1 regulates astrogenesis in the embryonic brain via modulation of RAS/MEK/ERK signaling through RASSF7. Development 143, 2732–2740 (2016).
Article CAS PubMed Google Scholar
Gogos, J. A. & Gerber, D. J. Schizophrenia susceptibility genes: emergence of positional candidates and future directions. Trends Pharmacol. Sci. 27, 226–233 (2006).
Article CAS PubMed Google Scholar
Zheng, W. et al. The possible role of the Akt signaling pathway in schizophrenia. Brain Res. 1470, 145–158 (2012).
Article CAS PubMed Google Scholar
Emamian, E. S., Hall, D., Birnbaum, M. J., Karayiorgou, M. & Gogos, J. A. Convergent evidence for impaired AKT1-GSK3beta signaling in schizophrenia. Nat. Genet. 36, 131–137 (2004).
Article CAS PubMed Google Scholar
Zhao, Z., Ksiezak-Reding, H., Riggio, S., Haroutunian, V. & Pasinetti, G. M. Insulin receptor deficits in schizophrenia and in cellular and animal models of insulin receptor dysfunction. Schizophrenia Res. 84, 1–14 (2006).
Article Google Scholar
Kvajo, M., McKellar, H. & Gogos, J. A. Molecules, signaling, and schizophrenia. Curr. Top. Behav. Neurosci. 4, 629–656 (2010).
Article PubMed Google Scholar
Chiou, S. H. et al. Poly(ADP-ribose) polymerase 1 regulates nuclear reprogramming and promotes iPSC generation without c-Myc. J. Exp. Med. 210, 85–98 (2013).
Article CAS PubMed PubMed Central Google Scholar
Weber, F. A., Bartolomei, G., Hottiger, M. O. & Cinelli, P. Artd1/Parp1 regulates reprogramming by transcriptional regulation of Fgf4 via Sox2 ADP-ribosylation. Stem Cells 31, 2364–2373 (2013).
Article CAS PubMed Google Scholar
Jiang, B. H. et al. Poly(ADP-Ribose) polymerase 1: cellular pluripotency, reprogramming, and tumorogenesis. Int. J. Mol. Sci. 16, 15531–15545 (2015).
Article CAS PubMed PubMed Central Google Scholar
Ju, B. G. et al. Activating the PARP-1 sensor component of the groucho/ TLE1 corepressor complex mediates a CaMKinase IIdelta-dependent neurogenic gene activation pathway. Cell 119, 815–829 (2004).
Article CAS PubMed Google Scholar
Matsuzaki, H., Daitoku, H., Hatta, M., Tanaka, K. & Fukamizu, A. Insulin-induced phosphorylation of FKHR (Foxo1) targets to proteasomal degradation. Proc. Natl Acad. Sci. USA 100, 11285–11290 (2003).
Article CAS PubMed PubMed Central Google Scholar
Lee, K., Nichols, J. & Smith, A. Identification of a developmentally regulated protein tyrosine phosphatase in embryonic stem cells that is a marker of pluripotential epiblast and early mesoderm. Mech. Dev. 59, 153–164 (1996).
Article CAS PubMed Google Scholar
Doumont, G. et al. G1 checkpoint failure and increased tumor susceptibility in mice lacking the novel p53 target Ptprv. EMBO J. 24, 3093–3103 (2005).
Article CAS PubMed PubMed Central Google Scholar
Doumont, G., Martoriati, A. & Marine, J. C. PTPRV is a key mediator of p53-induced cell cycle exit. Cell Cycle 4, 1703–1705 (2005).
Article CAS PubMed Google Scholar
Plane, J. M., Grossenbacher, S. K. & Deng, W. PARP-1 deletion promotes subventricular zone neural stem cells toward a glial fate. J. Neurosci. Res. 90, 1489–1506 (2012).
Article CAS PubMed PubMed Central Google Scholar
Ross, C. A., Margolis, R. L., Reading, S. A., Pletnikov, M. & Coyle, J. T. Neurobiology of schizophrenia. Neuron 52, 139–153 (2006).
Article CAS PubMed Google Scholar
Selemon, L. D. & Zecevic, N. Schizophrenia: a tale of two critical periods for prefrontal cortical development. Transl. Psychiatry 5, e623 (2015).
Article CAS PubMed PubMed Central Google Scholar
Johnstone, E. C., Crow, T. J., Frith, C. D., Husband, J. & Kreel, L. Cerebral ventricular size and cognitive impairment in chronic schizophrenia. Lancet 2, 924–926 (1976).
Article CAS PubMed Google Scholar
Weinberger, D. R., Torrey, E. F., Neophytides, A. N. & Wyatt, R. J. Lateral cerebral ventricular enlargement in chronic schizophrenia. Arch. Gen. Psychiatry 36, 735–739 (1979).
Article CAS PubMed Google Scholar
Zipursky, R. B., Lim, K. O., Sullivan, E. V., Brown, B. W. & Pfefferbaum, A. Widespread cerebral gray matter volume deficits in schizophrenia. Arch. Gen. Psychiatry 49, 195–205 (1992).
Article CAS PubMed Google Scholar
Wong, A. H. & Josselyn, S. A. Caution when diagnosing your mouse with schizophrenia: the use and misuse of model animals for understanding psychiatric disorders. Biol. Psychiatry 79, 32–38 (2016).
Article PubMed Google Scholar
Muir, W. J., Pickard, B. S. & Blackwood, D. H. Disrupted-in-schizophrenia-1. Curr. Psychiatry Rep. 10, 140–147 (2008).
Article PubMed Google Scholar
Soares, D. C., Carlyle, B. C., Bradshaw, N. J. & Porteous, D. J. DISC1: structure, function, and therapeutic potential for major mental illness. ACS Chem. Neurosci. 2, 609–632 (2011).
Article CAS PubMed PubMed Central Google Scholar
Singh, K. K. et al. Dixdc1 is a critical regulator of DISC1 and embryonic cortical development. Neuron 67, 33–48 (2010).
Article CAS PubMed PubMed Central Google Scholar
Kamiya, A. et al. A schizophrenia-associated mutation of DISC1 perturbs cerebral cortex development. Nat. Cell Biol. 7, 1167–1178 (2005).
Article PubMed CAS Google Scholar
Hayashi-Takagi, A. et al. Disrupted-in-schizophrenia 1 (DISC1) regulates spines of the glutamate synapse via Rac1. Nat. Neurosci. 13, 327–332 (2010).
Article CAS PubMed PubMed Central Google Scholar
Ishizuka, K. et al. DISC1-dependent switch from progenitor proliferation to migration in the developing cortex. Nature 473, 92–96 (2011).
Article CAS PubMed PubMed Central Google Scholar
Singh, K. K. et al. Common DISC1 polymorphisms disrupt Wnt/GSK3beta signaling and brain development. Neuron 72, 545–558 (2011).
Article CAS PubMed PubMed Central Google Scholar
Okuda, A. et al. Poly(ADP-ribose) polymerase inhibitors activate the p53 signaling pathway in neural stem/progenitor cells. BMC Neurosci. 18, 14 (2017).
Article PubMed PubMed Central CAS Google Scholar
Bonetto, A., Andersson, D. C. & Waning, D. L. Assessment of muscle mass and strength in mice. BoneKEy Rep. 4, 732 (2015).
Article PubMed PubMed Central Google Scholar

Download references

Acknowledgements

This work was supported by grants from the National Research Foundation of Korea (2015R1D1A1A01059794, 2018R1A2B6003173, 2014R1A2A11050360, and 2017R1A2B4006991). ESP promoter-luciferase construct was kindly provided by Dr. Gerard Karsenty (Columbia University, USA).

Author information

Seokheon Hong
Present address: Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, 02792, Republic of Korea
Jee Hyun Yi
Present address: Center for Synaptic Brain Dysfunction, Institute for Basic Science, Daejeon, 34126, Republic of Korea
These authors contributed equally: Seokheon Hong, Jee Hyun Yi

Authors and Affiliations

Department of Molecular Biology, Sejong University, Seoul, 05006, Republic of Korea
Seokheon Hong & Shin Jung Kang
Department of Biology, Kyung Hee University, Seoul, 02447, Republic of Korea
Jee Hyun Yi, Soonje Lee & Ki Soon Shin
Department of Microbiology, College of Medicine, Hanyang University, Seoul, 04763, Republic of Korea
Chang-Hwan Park
Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, 02447, Republic of Korea
Jong Hoon Ryu & Ki Soon Shin
Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul, 05006, Republic of Korea
Shin Jung Kang

Authors

Seokheon Hong
View author publications
You can also search for this author in PubMed Google Scholar
Jee Hyun Yi
View author publications
You can also search for this author in PubMed Google Scholar
Soonje Lee
View author publications
You can also search for this author in PubMed Google Scholar
Chang-Hwan Park
View author publications
You can also search for this author in PubMed Google Scholar
Jong Hoon Ryu
View author publications
You can also search for this author in PubMed Google Scholar
Ki Soon Shin
View author publications
You can also search for this author in PubMed Google Scholar
Shin Jung Kang
View author publications
You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Ki Soon Shin or Shin Jung Kang.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Edited by A. Verkhratsky

Supplementary information

Supplementary figure legends

Supplementary figure 1

Supplementary figure 2

Supplementary figure 3

Supplementary figure 4

Supplementary figure 5

Supplementary figure 6

Supplementary figure 7

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and permissions

About this article

Cite this article

Hong, S., Yi, J.H., Lee, S. et al. Defective neurogenesis and schizophrenia-like behavior in PARP-1-deficient mice. Cell Death Dis 10, 943 (2019). https://doi.org/10.1038/s41419-019-2174-0

Download citation

Received: 01 February 2019
Revised: 21 November 2019
Accepted: 22 November 2019
Published: 09 December 2019
DOI: https://doi.org/10.1038/s41419-019-2174-0

This article is cited by

Autophagy-related gene model as a novel risk factor for schizophrenia
- Yunfei Tan
- Junpeng Zhu
- Kenji Hashimoto
Translational Psychiatry (2024)
Molecular mapping of a core transcriptional signature of microglia-specific genes in schizophrenia
- Anna M. Fiorito
- Eric Fakra
- Romain Rey
Translational Psychiatry (2023)
Towards resolving the enigma of the dichotomy of resveratrol: cis- and trans-resveratrol have opposite effects on TyrRS-regulated PARP1 activation
- Megha Jhanji
- Chintada Nageswara Rao
- Mathew Sajish
GeroScience (2021)