[Mechanism of traditional Chinese medicine in treating ulcerative colitis-related colorectal cancer by regulating NF-κB-related signaling pathways: a review].

Ulcerative colitis is a chronic, recurrent, and nonspecific intestinal inflammatory disease, which is difficult to cure and has the risk of deterioration into related tumors. Long-term chronic inflammatory stimulation can increase the risk of cancerization. With the signaling pathway as a key link in the regulation of tumor microenvironments, nuclear factor-kappa B(NF-κB) is an important regulator of intestinal inflammation. It can also be co-regulated as downstream factors of other signaling pathways, such as TLR4, MAPK, STAT, PI3K, and so on. At present, a large number of animal experiments have proved that traditional Chinese medicine(TCM) can reduce inflammation by interfering with NF-κB-related signaling pathways, improve intestinal inflammation, and inhibit the progression of inflammation to tumors. This article reviewed the relationship between NF-κB-related signaling pathways and the intervention mechanism of TCM, so as to provide a reference for the clinical treatment of ulcerative colitis and the optimization of related cancer prevention strategies.

[Effect of Film Mulching Age and Organic Fertilizer Application on the Distribution Characteristics of Microplastics in the Soil of a Peanut Field].

The large input of mulch film and organic fertilizer have led to increasingly serious microplastic pollution in farmland soil of China. In this study, the microplastic pollution of peanut farmland in Dezhou City, Shandong Province was investigated. The effects of different mulching years (0, 3, 5, and 8 years) and organic fertilizer application on the abundance, particle size, color, and shape of microplastics in farmland soil were analyzed. The results showed that the average abundances of microplastics in peanut soil were 65.33, 316.00, 1 098.67, and 1 346.34 n·kg-1, respectively, after 0, 3, 5, and 8 years of film mulching. The abundance of microplastics decreased with the increase in soil depth. The abundance of microplastics in 0-10, 10-20, and 20-30 cm topsoil was 1 076.00, 603.5, and 440.25 n·kg-1, respectively, and the abundance of microplastics increased significantly with increasing years of film mulching and organic fertilizer application (P<0.05). The particle size of microplastics in the sample plot <1 mm accounted for 77.30% of the total content, and with the increase in film mulching age, the proportion of microplastics with small particle size (<1 mm) increased significantly (P < 0.05). With the increase in soil depth, the proportion of microplastics with small particle size also gradually increased, whereas the application of organic fertilizer had no significant effect on the particle size of microplastics. The color of microplastics in the plot was mainly transparent (49.77%), followed by black (16.35%) and white (16.27%). The planting age and organic fertilizer application had no significant effect on the color of microplastics in the soil (P > 0.05), but the mulching age significantly increased the proportion of transparent microplastics. The abundance proportion of the five types of microplastics were 49.77%, 25.41%, 19.15%, 3.26%, and 2.41%, respectively. These field soil microplastics were mainly composed of polyethylene (PE), polypropylene (PP), and polystyrene (PS) polymers, accounting for 21.37%, 18.57%, and 19.77% of the total, respectively. Therefore, microplastics were widely present in the soil of the peanut field cultivated layer in Dezhou, Shandong, and the applications of mulch film and organic fertilizer were the main source. This study provides an important basis for the prevention and control of soil microplastic pollution in peanut fields.

RNF220-mediated K63-linked polyubiquitination stabilizes Olig proteins during oligodendroglial development and myelination.

Maldevelopment of oligodendroglia underlies neural developmental disorders such as leukodystrophy. Precise regulation of the activity of specific transcription factors (TFs) by various posttranslational modifications (PTMs) is required to ensure proper oligodendroglial development and myelination. However, the role of ubiquitination of these TFs during oligodendroglial development is yet unexplored. Here, we find that RNF220, a known leukodystrophy-related E3 ubiquitin ligase, is required for oligodendroglial development. RNF220 depletion in oligodendrocyte lineage cells impedes oligodendrocyte progenitor cell proliferation, differentiation, and (re)myelination, which consequently leads to learning and memory defects. Mechanistically, RNF220 targets Olig1/2 for K63-linked polyubiquitination and stabilization during oligodendroglial development. Furthermore, in a knock-in mouse model of leukodystrophy-related RNF220R365Q mutation, the ubiquitination and stabilization of Olig proteins are deregulated in oligodendroglial cells. This results in pathomimetic oligodendroglial developmental defects, impaired myelination, and abnormal behaviors. Together, our evidence provides an alternative insight into PTMs of oligodendroglial TFs and how this essential process may be implicated in the etiology of leukodystrophy.

Neural plasticity and depression treatment.

Depression is one of the most common mental disorders, which can lead to a variety of emotional problems and even suicide at its worst. As this neuropsychiatric disorder causes the patients to suffer a lot and function poorly in everyday life, it is imposing a heavy burden on the affected families and the whole society. Several hypotheses have been proposed to elucidate the pathogenesis of depression, such as the genetic mutations, the monoamine hypothesis, the hypothalamic-pituitary-adrenal (HPA) axis hyperactivation, the inflammation and the neural plasticity changes. Among these models, neural plasticity can occur at multiple levels from brain regions, cells to synapses structurally and functionally during development and in adulthood. In this review, we summarize the recent progresses (especially in the last five years) on the neural plasticity changes in depression under different organizational levels and elaborate different treatments for depression by changing the neural plasticity. We hope that this review would shed light on the etiological studies for depression and on the development of novel treatments.

Overexpression of EphB6 and EphrinB2 controls soma spacing of cortical neurons in a mutual inhibitory way.

To establish functional circuitry, neurons settle down in a particular spatial domain by spacing their cell bodies, which requires proper positioning of the soma and establishing of a zone with unique connections. Deficits in this process are implicated in neurodevelopmental diseases. In this study, we examined the function of EphB6 in the development of cerebral cortex. Overexpression of EphB6 via in utero electroporation results in clumping of cortical neurons, while reducing its expression has no effect. In addition, overexpression of EphrinB2, a ligand of EphB6, also induces soma clumping in the cortex. Unexpectedly, the soma clumping phenotypes disappear when both of them are overexpressed in cortical neurons. The mutual inhibitory effect of EphB6/ EphrinB2 on preventing soma clumping is likely to be achieved via interaction of their specific domains. Thus, our results reveal a combinational role of EphrinB2/EphB6 overexpression in controlling soma spacing in cortical development.

RNF220 is an E3 ubiquitin ligase for AMPA receptors to regulate synaptic transmission.

The accurate expression of postsynaptic AMPA receptors (AMPARs) is critical for information processing in the brain, and ubiquitination is a key regulator for this biological process. However, the roles of E3 ubiquitin ligases in the regulation of AMPARs are poorly understood. Here, we find that RNF220 directly interacts with AMPARs to meditate their polyubiquitination, and RNF220 knockout specifically increases AMPAR protein levels, thereby enhancing basal synaptic activity while impairing synaptic plasticity. Moreover, depending on its E3 ubiquitin ligase activity, RNF220 represses AMPAR-mediated excitatory synaptic responses and their neuronal surface expression. Furthermore, learning and memory are altered in forebrain RNF220-deficient mice. In addition, two neuropathology-related RNF220 variants fail to repress excitatory synaptic activity because of the incapability to regulate AMPAR ubiquitination due to their attenuated interaction. Together, we identify RNF220 as an E3 ubiquitin ligase for AMPARs and establish its substantial role in excitatory synaptic transmission and brain function.

Deletion of Schizophrenia Susceptibility Gene Ulk4 Leads to Abnormal Cognitive Behaviors via Akt-GSK-3 Signaling Pathway in Mice.

OBJECTIVES: Despite of strenuous research in the past decades, the etiology of schizophrenia (SCZ) still remains incredibly controversial. Previous genetic analysis has uncovered a close association of Unc-51 like kinase 4 (ULK4), a family member of Unc-51-like serine/threonine kinase, with SCZ. However, animal behavior data which may connect Ulk4 deficiency with psychiatric disorders, particularly SCZ are still missing. METHODS: We generated Emx1-Cre:Ulk4flox/flox conditional knockout (CKO) mice, in which Ulk4 was deleted in the excitatory neurons of cerebral cortex and hippocampus. RESULTS: The cerebral cellular architecture was maintained but the spine density of pyramidal neurons was reduced in Ulk4 CKO mice. CKO mice showed deficits in the spatial and working memories and sensorimotor gating. Levels of p-Akt and p-GSK-3α/ß were markedly reduced in the CKO mice indicating an elevation of GSK-3 signaling. Mechanistically, Ulk4 may regulate the GSK-3 signaling via putative protein complex comprising of two phosphatases, protein phosphatase 2A (PP2A) and 1α (PP1α). Indeed, the reduction of p-Akt and p-GSK-3α/ß was rescued by administration of inhibitor acting on PP2A and PP1α in CKO mice. CONCLUSIONS: Our data identified potential downstream signaling pathway of Ulk4, which plays important roles in the cognitive functions and when defective, may promote SCZ-like pathogenesis and behavioral phenotypes in mice.

The role of PTEN in primary sensory neurons in processing itch and thermal information in mice.

PTEN is known as a tumor suppressor and plays essential roles in brain development. Here, we report that PTEN in primary sensory neurons is involved in processing itch and thermal information in adult mice. Deletion of PTEN in the dorsal root ganglia (DRG) is achieved in adult Drg11-CreER: PTENflox/flox (PTEN CKO) mice with oral administration of tamoxifen, and CKO mice develop pathological itch and elevated itch responses on exposure to various pruritogens. PTEN deletion leads to ectopic expression of TRPV1 and MrgprA3 in IB4+ non-peptidergic DRG neurons, and the TRPV1 is responsive to capsaicin. Importantly, the elevated itch responses are no longer present in Drg11-CreER: PTENflox/flox: TRPV1flox/flox (PTEN: TRPV1 dCKO) mice. In addition, thermal stimulation is enhanced in PTEN CKO mice but blunted in dCKO mice. PTEN-involved regulation of itch-related gene expression in DRG neurons provides insights for understanding molecular mechanism of itch and thermal sensation at the spinal level.

Rnf220 is Implicated in the Dorsoventral Patterning of the Hindbrain Neural Tube in Mice.

Rnf220 is reported to regulate the patterning of the ventral spinal neural tube in mice. The brainstem has divergent connections with peripheral and central targets and contains unique internal neuronal groups, but the role of Rnf220 in the early development of the hindbrain has not been explored. In this study, Nestin-Cre-mediated conditional knockout (Rnf220 Nestin CKO) mice were used to examine if Rnf220 is involved in the early morphogenesis of the hindbrain. Rnf220 showed restricted expression in the ventral half of ventricular zone (VZ) of the hindbrain at embryonic day (E) 10.5, and as development progressed, Rnf220-expressing cells were also present in the mantle zone outside the VZ at E12.5. In Rnf220 Nestin CKO embryos, alterations of progenitor domains in the ventral VZ were observed at E10.5. There were significant reductions of the p1 and p2 domains shown by expression of Dbx1, Olig2, and Nkx6.1, accompanied by a ventral expansion of the Dbx1+ p0 domain and a dorsal expansion of the Nkx2.2+ p3 domain. Different from the case in the spinal cord, the Olig2+ pMN (progenitors of somatic motor neuron) domain shifted and expanded dorsally. Notably, the total range of the ventral VZ and the extent of the dorsal tube were unchanged. In addition, the post-mitotic cells derived from their corresponding progenitor domain, including oligodendrocyte precursor cells (OPCs) and serotonergic neurons (5-HTNs), were also changed in the same trend as the progenitor domains do in the CKO embryos at E12.5. In summary, our data suggest similar functions of Rnf220 in the hindbrain dorsoventral (DV) patterning as in the spinal cord with different effects on the pMN domain. Our work also reveals novel roles of Rnf220 in the development of 5-HTNs and OPCs.

Satb2 Regulates EphA7 to Control Soma Spacing and Self-Avoidance of Cortical Pyramidal Neurons.

Soma spacing and dendritic arborization during brain development are key events for the establishment of proper neural circuitry and function. Transcription factor Satb2 is a molecular node in regulating the development of the cerebral cortex, as shown by the facts that Satb2 is required for the regionalization of retrosplenial cortex, the determination of callosal neuron fate, and the regulation of soma spacing and dendritic self-avoidance of cortical pyramidal neurons. In this study, we explored downstream effectors that mediate the Satb2-implicated soma spacing and dendritic self-avoidance. First, RNA-seq analysis of the cortex revealed differentially expressed genes between control and Satb2 CKO mice. Among them, EphA7 transcription was dramatically increased in layers II/III of Satb2 CKO cortex. Overexpression of EphA7 in the late-born cortical neurons of wild-type mice via in utero electroporation resulted in soma clumping and impaired self-avoidance of affected pyramidal neurons, which resembles the phenotypes caused by knockdown of Satb2 expression. Importantly, the phenotypes by Satb2 knockdown was rescued by reducing EphA7 expression in the cortex. Finally, ChIP and luciferase reporter assays indicated a direct suppression of EphA7 expression by Satb2. These findings provide new insights into the complexity of transcriptional regulation of the morphogenesis of cerebral cortex.

Satb2 regulates the development of dopaminergic neurons in the arcuate nucleus by Dlx1.

Dopaminergic (DA) neurons in the arcuate nucleus (ARC) of the hypothalamus play essential roles in the secretion of prolactin and the regulation of energy homeostasis. However, the gene regulatory network responsible for the development of the DA neurons remains poorly understood. Here we report that the transcription factor special AT-rich binding protein 2 (Satb2) is required for the development of ARC DA neurons. Satb2 is expressed in a large proportion of DA neurons without colocalization with proopiomelanocortin (POMC), orexigenic agouti-related peptide (AgRP), neuropeptide-Y (NPY), somatostatin (Sst), growth hormone-releasing hormone (GHRH), or galanin in the ARC. Nestin-Cre;Satb2flox/flox (Satb2 CKO) mice show a reduced number of ARC DA neurons with unchanged numbers of the other types of ARC neurons, and exhibit an increase of serum prolactin level and an elevated metabolic rate. The reduction of ARC DA neurons in the CKO mice is observed at an embryonic stage and Dlx1 is identified as a potential downstream gene of Satb2 in regulating the development of ARC DA neurons. Together, our study demonstrates that Satb2 plays a critical role in the gene regulatory network directing the development of DA neurons in ARC.

Influence of Electrolyte Concentration on Single-Molecule Sensing of Perfluorocarboxylic Acids.

Perfluorocarboxylic acids (PFCAs) are an emerging class of persistent organic pollutants. During the fabrication process, it is unavoidable to form PFCA homologs or isomers which exhibit distinct occurrence, bioaccumulation, and toxicity. The precision measurement of PFCAs is therefore of significant importance. However, the existing characterization techniques, such as LC-MS/MS, cannot fully meet the requirement of isomer-specific analysis, largely due to the lack of authentic standards. Single-molecule sensors (SMSs) based on nanopore electrochemistry may be a feasible solution for PFCAs determination, thanks to their ultra-high spatiotemporal resolutions. Hence, as a first step, this work was to elucidate the influence of electrolyte concentration on the four most critical indicators of nanopore measurements, and furthermore, performance of nanopore SMSs. More specifically, three of the most representative short-chain PFCAs, perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and perfluoroheptanoic acid (PFHpA), were adopted as the target analytes, aerolysin nanopore was employed as the sensing interface, and 2, 3 and 4 M KCl solutions were used as electrolytes. It was found that, when the concentration of KCl solution increased from 2 to 4 M, the conductance of aerolysin nanopore increased almost linearly at a rate of 0.5 nS per molar KCl within the whole voltage range, the current blockade of PFPeA at -50 mV increased from 61.74 to 66.57% owing to the enhanced steric exclusion effect, the maximum dwell time was more than doubled from 14.5 to 31.5 ms, and the barrier limited capture rate increased by 8.3 times from 0.46 to 3.85 Hz. As a result, when using 4 M KCl as the electrolyte, over 90% of the PFPeA, PFHxA and PFHpA were accurately identified from a mixed sample, and the calculated limit of detection of PFPeA reached 320 nM, more than 24 times lower than in 2 M KCl. It was thus clear that tuning the electrolyte concentration was a simple but very effective approach to improve the performance of nanopore SMSs for PFCAs determination.

Ulk4, a Newly Discovered Susceptibility Gene for Schizophrenia, Regulates Corticogenesis in Mice.

Schizophrenia (SCZ) is a chronic and severe mental disease that affects around 1% of the population. The precise etiology of SCZ still remains largely unknown, and no conclusive mechanisms are firmly established. Recent advances in epidemiological and clinical investigation support an overwhelmingly strong neurodevelopmental origin for SCZ. Here, we demonstrated that Unc-51-like kinase 4 (Ulk4), a novel risk factor for major mental disorders including schizophrenia, is involved in the corticogenesis. Deletion of Ulk4 in mice led to significantly thinner layers of II-III, and V in the cerebral cortex, which was confirmed in conditional Ulk4 deletion mice achieved by Cre-loxp strategy. This abnormality might be caused by decreased intermediate neural progenitors and increased apoptosis. Thus, our data suggest that Ulk4 manipulates the behaviors of neural progenitors during brain development and, when functionally defective, leads to the reduction of specific cortical layers. This anomaly may increase predisposition to a range of neurodevelopmental disorders, including SCZ.

Enhanced Photocatalytic Degradation of Perfluorooctanoic Acid by Mesoporous Sb2O3/TiO2 Heterojunctions.

Perfluorooctanoic acid (PFOA), a typical perfluorinated carboxylic acid, is an emerging type of permanent organic pollutants that are regulated by the Stockholm Convention. The degradation of PFOA, however, is quite challenging largely due to the ultra-high stability of C-F bonds. Compared with other techniques, photocatalytic degradation offers the potential advantages of simple operation under mild conditions as well as exceptional decomposition and defluorination efficiency. Titanium dioxide (TiO2) is one of the most frequently used photocatalysts, but so far, the pristine nanosized TiO2 (e.g., the commercial P25) has been considered inefficient for PFOA degradation, since the photo-generated hydroxyl radicals from TiO2 are not able to directly attack C-F bonds. Mesoporous Sb2O3/TiO2 heterojunctions were therefore rationally designed in this work, of which the confined Sb2O3 nanoparticles in mesoporous TiO2 framework could not only tune the band structure and also increase the number of active sites for PFOA degradation. It was found that, after loading Sb2O3, the absorption of UV light was enhanced, indicating a higher efficiency of light utilization; while the band gap was reduced, which accelerated the separation of photo-generated charge carriers; and most importantly, the valence band edge of the Sb2O3/TiO2 heterojunction was significantly lifted so as to prevent the occurrence of hydroxyl radical pathway. Under the optimal ratio of Sb2O3-TiO2, the resulting catalysts managed to remove 81.7% PFOA in 2 h, with a degradation kinetics 4.2 times faster than the commercial P25. Scavenger tests and electron spin resonance spectra further revealed that such improvement was mainly attributed to the formation of superoxide radicals and photo-generated holes, in which the former drove the decarboxylation from C7F15COOH-C7F15 •, and the latter promoted the direct electron transfer for the conversion of C7F15COO--C7F15COO•. The Sb2O3/TiO2 photocatalysts were highly recyclable, with nearly 90% of the initial activity being retained after five consecutive cycles, guaranteeing the feasibility of long-term operation.

Pten is a key intrinsic factor regulating raphe 5-HT neuronal plasticity and depressive behaviors in mice.

Serotonin (5-HT)-based antidepressants, selective serotonin reuptake inhibitors (SSRIs) aim to enhance serotonergic activity by blocking its reuptake. We propose PTEN as a target for an alternative approach for regulating 5-HT neuron activity in the brain and depressive behaviors. We show that PTEN is elevated in central 5-HT neurons in the raphe nucleus by chronic stress in mice, and selective deletion of Pten in the 5-HT neurons induces its structural plasticity shown by increases of dendritic branching and density of PSD95-positive puncta in the dendrites. 5-HT levels are elevated and electrical stimulation of raphe neurons evokes more 5-HT release in the brain of condition knockout (cKO) mice with Pten-deficient 5-HT neurons. In addition, the 5-HT neurons remain normal electrophysiological properties but have increased excitatory synaptic inputs. Single-cell RNA sequencing revealed gene transcript alterations that may underlay morphological and functional changes in Pten-deficient 5-HT neurons. Finally, Pten cKO mice and wild-type mice treated with systemic application of PTEN inhibitor display reduced depression-like behaviors. Thus, PTEN is an intrinsic regulator of 5-HT neuron activity, representing a novel therapeutic strategy for producing antidepressant action.

Triterpenoid saponins and phenylpropanoid glycoside from the roots of Ardisia crenata and their cytotoxic activities.

Two new triterpenoid saponins, ardisicrenoside R and S (1 and 2), and one new phenylpropanoid glycoside, ardicrephenin (3), along with five known compounds (4-8), were isolated from roots of Ardisia crenata. Their structures were elucidated on the basis of NMR spectroscopic data and chemical methods. Compounds 2-7 were evaluated for their cytotoxic activities against A549, MCF-7, HepG2 and MDA-MB-231 cell lines by MTT assay. Ardicrenin (6) showed significant cytotoxicity, with IC50 values of 1.17 ± 0.01, 1.19 ± 0.06, 3.52 ± 0.23, and 16.61 ± 1.02 µmol·L-1, respectively.

ZFP804A mutant mice display sex-dependent schizophrenia-like behaviors.

Genome-wide association studies uncovered the association of ZNF804A (Zinc-finger protein 804A) with schizophrenia (SZ). In vitro data have indicated that ZNF804A might exert its biological roles by regulating spine and neurite morphogenesis. However, no in vivo data are available for the role of ZNF804A in psychiatric disorders in general, SZ in particular. We generated ZFP804A mutant mice, and they showed deficits in contextual fear and spatial memory. We also observed the sensorimotor gating impairment, as revealed by the prepulse inhibition test, but only in female ZFP804A mutant mice from the age of 6 months. Notably, the PPI difference between the female mutant and control mice was no longer existed with the administration of Clozapine or after the ovariectomy. Hippocampal long-term potentiation was normal in both genders of the mutant mice. Long-term depression was absent in male mutants, but facilitated in the female mutants. Protein levels of hippocampal serotonin-6 receptor and GABAB1 receptor were increased, while those of cortical dopamine 2 receptor were decreased in the female mutants with no obvious changes in the male mutants. Moreover, the spine density was reduced in the cerebral cortex and hippocampus of the mutant mice. Knockdown of ZFP804A impaired the neurite morphogenesis of cortical and hippocampal neurons, while its overexpression enhanced neurite morphogenesis only in the cortical neurons in vitro. Our data collectively support the idea that ZFP804A/ZNF804A plays important roles in the cognitive functions and sensorimotor gating, and its dysfunction may contribute to SZ, particularly in the female patients.

Rnf220/Zc4h2-mediated monoubiquitylation of Phox2 is required for noradrenergic neuron development.

Noradrenaline belongs to the monoamine system and is involved in cognition and emotional behaviors. Phox2a and Phox2b play essential but non-redundant roles during development of the locus coeruleus (LC), the main noradrenergic (NA) neuron center in the mammalian brain. The ubiquitin E3 ligase Rnf220 and its cofactor Zc4h2 participate in ventral neural tube patterning by modulating Shh/Gli signaling, and ZC4H2 mutation is associated with intellectual disability, although the mechanisms for this remain poorly understood. Here, we report that Zc4h2 and Rnf220 are required for the development of central NA neurons in the mouse brain. Both Zc4h2 and Rnf220 are expressed in developing LC-NA neurons. Although properly initiated at E10.5, the expression of genes associated with LC-NA neurons is not maintained at the later embryonic stages in mice with a deficiency of either Rnf220 or Zc4h2 In addition, we show that the Rnf220/Zc4h2 complex monoubiquitylates Phox2a/Phox2b, a process required for the full transcriptional activity of Phox2a/Phox2b. Our work reveals a role for Rnf220/Zc4h2 in regulating LC-NA neuron development, and this finding may be helpful for understanding the pathogenesis of ZC4H2 mutation-associated intellectual disability.

ZC4H2 stabilizes RNF220 to pattern ventral spinal cord through modulating Shh/Gli signaling.

ZC4H2 encodes a C4H2 type zinc-finger nuclear factor, the mutation of which has been associated with disorders with various clinical phenotypes in human, including developmental delay, intellectual disability and dystonia. ZC4H2 has been suggested to regulate spinal cord patterning in zebrafish as a co-factor for RNF220, an ubiquitin E3 ligase involved in Gli signaling. Here we showed that ZC4H2 and RNF220 knockout animals phenocopy each other in spinal patterning in both mouse and zebrafish, with mispatterned progenitor and neuronal domains in the ventral spinal cord. We showed evidence that ZC4H2 is required for the stability of RNF220 and also proper Gli ubiquitination and signaling in vivo. Our data provides new insights into the possible etiology of the neurodevelopmental impairments observed in ZC4H2-associated syndromes.

Satb2 is required for the regionalization of retrosplenial cortex.

The retrosplenial cortex (Rsp) is a transitional cortex located between the neocortex and archicortex, but the molecular mechanism specifying Rsp from the archicortex remains elusive. We here report that the transcription factor Satb2 is required for specifying Rsp identity during its morphogenesis. In Satb2 CKO mice, the boundary between the Rsp and archicortex [i.e., subiculum (SubC)] disappears as early as E17.5, and Rsp efferent projection is aberrant. Rsp-specific genes are lost, whereas SubC-specific genes are ectopically expressed in Rsp of Satb2 CKO mice. Furthermore, cell-autonomous role of Satb2 in maintaining Rsp neuron identity is revealed by inactivation of Satb2 in Rsp neurons. Finally, Satb2 represses the transcription of Nr4a2. The misexpression of Nr4a2 together with Ctip2 induces expression of SubC-specific genes in wild-type Rsp, and simultaneous knockdown of these two genes in Rsp Satb2-mutant cells prevents their fate transition to SubC identity. Thus, Satb2 serves as a determinant gene in the Rsp regionalization by repressing Nr4a2 and Ctip2 during cortical development.