SATB2 organizes the 3D genome architecture of cognition in cortical neurons.

The DNA-binding protein SATB2 is genetically linked to human intelligence. We studied its influence on the three-dimensional (3D) epigenome by mapping chromatin interactions and accessibility in control versus SATB2-deficient cortical neurons. We find that SATB2 affects the chromatin looping between enhancers and promoters of neuronal-activity-regulated genes, thus influencing their expression. It also alters A/B compartments, topologically associating domains, and frequently interacting regions. Genes linked to SATB2-dependent 3D genome changes are implicated in highly specialized neuronal functions and contribute to cognitive ability and risk for neuropsychiatric and neurodevelopmental disorders. Non-coding DNA regions with a SATB2-dependent structure are enriched for common variants associated with educational attainment, intelligence, and schizophrenia. Our data establish SATB2 as a cell-type-specific 3D genome modulator, which operates both independently and in cooperation with CCCTC-binding factor (CTCF) to set up the chromatin landscape of pyramidal neurons for cognitive processes.

ZFP451-mediated SUMOylation of SATB2 drives embryonic stem cell differentiation.

The establishment of cell fates involves alterations of transcription factor repertoires and repurposing of transcription factors by post-translational modifications. In embryonic stem cells (ESCs), the chromatin organizers SATB2 and SATB1 balance pluripotency and differentiation by activating and repressing pluripotency genes, respectively. Here, we show that conditional Satb2 gene inactivation weakens ESC pluripotency, and we identify SUMO2 modification of SATB2 by the E3 ligase ZFP451 as a potential driver of ESC differentiation. Mutations of two SUMO-acceptor lysines of Satb2 (Satb2K →R ) or knockout of Zfp451 impair the ability of ESCs to silence pluripotency genes and activate differentiation-associated genes in response to retinoic acid (RA) treatment. Notably, the forced expression of a SUMO2-SATB2 fusion protein in either Satb2K →R or Zfp451-/- ESCs rescues, in part, their impaired differentiation potential and enhances the down-regulation of Nanog The differentiation defect of Satb2K →R ESCs correlates with altered higher-order chromatin interactions relative to Satb2wt ESCs. Upon RA treatment of Satb2wt ESCs, SATB2 interacts with ZFP451 and the LSD1/CoREST complex and gains binding at differentiation genes, which is not observed in RA-treated Satb2K →R cells. Thus, SATB2 SUMOylation may contribute to the rewiring of transcriptional networks and the chromatin interactome of ESCs in the transition of pluripotency to differentiation.

SATB2-LEMD2 interaction links nuclear shape plasticity to regulation of cognition-related genes.

SATB2 is a schizophrenia risk gene and is genetically associated with human intelligence. How it affects cognition at molecular level is currently unknown. Here, we show that interactions between SATB2, a chromosomal scaffolding protein, and the inner nuclear membrane protein LEMD2 orchestrate the response of pyramidal neurons to neuronal activation. Exposure to novel environment in vivo causes changes in nuclear shape of CA1 hippocampal neurons via a SATB2-dependent mechanism. The activity-driven plasticity of the nuclear envelope requires not only SATB2, but also its protein interactor LEMD2 and the ESCRT-III/VPS4 membrane-remodeling complex. Furthermore, LEMD2 depletion in cortical neurons, similar to SATB2 ablation, affects neuronal activity-dependent regulation of multiple rapid and delayed primary response genes. In human genetic data, LEMD2-regulated genes are enriched for de novo mutations reported in intellectual disability and schizophrenia and are, like SATB2-regulated genes, enriched for common variants associated with schizophrenia and cognitive function. Hence, interactions between SATB2 and the inner nuclear membrane protein LEMD2 influence gene expression programs in pyramidal neurons that are linked to cognitive ability and psychiatric disorder etiology.

Spatial transcriptome reveals the region-specific genes and pathways regulated by Satb2 in neocortical development.

BACKGROUND: It is known that the neurodevelopmental disorder associated gene, Satb2, plays important roles in determining the upper layer neuron specification. However, it is not well known how this gene regulates other neocortical regions during the development. It is also lack of comprehensive delineation of its spatially regulatory pathways in neocortical development. RESULTS: In this work, we utilized spatial transcriptomics and immuno-staining to systematically investigate the region-specific gene regulation of Satb2 by comparing the Satb2+/+ and Satb2-/- mice at embryonic stages, including the ventricle zone (VZ) or subventricle zone (SVZ), intermediate zone (IZ) and cortical plate (CP) respectively. The staining result reveals that these three regions become moderately or significantly thinner in the Satb2-/- mice. In the cellular level, the cell number increases in the VZ/SVZ, whereas the cell number decreases in the CP. The spatial transcriptomics data show that many important genes and relevant pathways are dysregulated in Satb2-/- mice in a region-specific manner. In the VZ/SVZ, the key genes involved in neural precursor cell proliferation, including the intermediate progenitor marker Tbr2 and the lactate production related gene Ldha, are up-regulated in Satb2-/- mice. In the IZ, the key genes in regulating neuronal differentiation and migration, such as Rnd2, exhibit ectopic expressions in the Satb2-/- mice. In the CP, the lineage-specific genes, Tbr1 and Bcl11b, are abnormally expressed. The neuropeptide related gene Npy is down-regulated in Satb2-/- mice. Finally, we validated the abnormal expressions of key regulators by using immunofluorescence or qPCR. CONCLUSIONS: In summary, our work provides insights on the region-specific genes and pathways which are regulated by Satb2 in neocortical development.

Abnormalities in pharyngeal arch-derived structures in SATB2-associated syndrome.

SATB2-associated syndrome (SAS, glass syndrome, OMIM#612313) is a neurodevelopmental autosomal dominant disorder with frequent craniofacial abnormalities including palatal and dental anomalies. To assess the role of Satb2 in craniofacial development, we analyzed mutant mice at different stages of development. Here, we show that Satb2 is broadly expressed in early embryonic mouse development including the mesenchyme of the second and third arches. Satb2-/- mutant mice exhibit microglossia, a shortened lower jaw, smaller trigeminal ganglia, and larger thyroids. We correlate these findings with the detailed clinical phenotype of four individuals with SAS and remarkable craniofacial phenotypes with one requiring mandibular distraction in childhood. We conclude that the mouse and patient data presented support less well-described phenotypic aspects of SAS including mandibular morphology and thyroid anatomical/functional issues.

Bone health in SATB2-associated syndrome: Results from a large prospective cohort and recommendations for surveillance.

Alterations in SATB2 result in SATB2-associated syndrome (SAS; Glass syndrome, OMIM 612313), an autosomal dominant multisystemic disorder predominantly characterized by developmental delay, craniofacial anomalies, and growth retardation. The bone phenotype of SAS has been less explored until recently and includes a variety of skeletal deformities, increased risk of low bone mineral density (BMD) with a propensity to fractures, and other biochemical abnormalities that suggest elevated bone turnover. We present the results of ongoing surveillance of bone health from 32 individuals (47% females, 3-18 years) with molecularly-confirmed SAS evaluated at a multidisciplinary clinic. Five individuals (5/32, 16%) were documented to have BMD Z-scores by DXA scans of -2.0 SD or lower and 7 more (7/32, 22%) had Z-scores between -1 and - 2 SD at the lumbar spine or the total hip. Alkaline phosphatase levels were found to be elevated in 19 individuals (19/30, 63%) and determined to correspond to bone-specific alkaline phosphatase elevations when measured (11/11, 100%). C-telopeptide levels were found to be elevated when adjusted by age and gender in 6 individuals (6/14, 43%). Additionally, the two individuals who underwent bone cross-sectional geometry evaluation by peripheral quantitative computed tomography were documented to have low cortical bone density for age and sex despite concurrent DXA scans that did not have this level of decreased density. While we could not identify particular biochemical abnormalities that predicted low BMD, the frequent elevations in markers of bone formation and resorption further confirmed the increased bone turnover in SAS. Based on our results and other recently published studies, we propose surveillance guidelines for the skeletal phenotype of SAS.

Meta-analysis of SATB2 immunohistochemical expression in colorectal cancer versus primary ovarian mucinous neoplasms.

BACKGROUND: Reliably distinguishing primary ovarian mucinous neoplasms (POMNs) from metastatic colorectal cancers (CRCs) is both challenging to the histopathologist and of great clinical importance. Special AT-rich sequence binding protein-2 (SATB2) has emerged as a useful diagnostic immunohistochemical marker of colorectal cancer. This meta-analysis compares SATB2 expression in POMNs and CRC. METHODS: A systematic literature search for relevant studies was conducted. Meta-analysis of SATB2 positivity was undertaken using a random effects model. RESULTS: Seven studies including 711 CRCs and 528 POMNs were included. SATB2 positivity was seen in 81 % (95 % CI: 72-88 %) of CRCs and 4 % (95 % CI: 1-11 %) of POMNs. Variation was seen in immunohistochemical methods used for SATB2 detection and threshold for positivity. CONCLUSION: SATB2 staining remains high in CRC and low in POMNs, supporting its use in differentiating these two pathologies with vastly differing prognosis and treatment.

Concomitant expression patterns of CDX2 and SATB2 as prognostic factors in stage III colorectal cancers.

CDX2 and SATB2 are often used as biomarkers for identification of colorectal origin in primary or metastatic adenocarcinomas. Loss of CDX2 or SATB2 expression has been associated with poor prognosis in patients with colorectal cancer (CRC). However, little is known regarding clinicopathological features, including prognosis, of CRCs with concomitant loss of CDX2 and SATB2. A total of 431 stage III CRCs were analyzed for their expression status in CDX2 and SATB2 using tissue microarray-based immunohistochemistry and expression status was correlated with clinicopathological variables, molecular alterations, and survival. CDX2-negative (CDX2-) CRCs and SATB2-negative (SATB2-) CRCs were found in 8.1 % and 17.2 % of CRCs, respectively, whereas both CDX2-negative and SATB2-negative (CDX2-/SATB2-) CRCs comprised 3.2 % of the CRCs. On survival analysis, neither CDX2-/SATB2+ nor CDX2+/SABT2- CRCs but CDX2-/SATB2- CRCs were associated with poor prognosis. CDX2-/SATB2- CRCs showed significant associations with tumor subsite of right colon, poor differentiation, decreased expression of CK20, aberrant expression of CK7, CIMP-high, MSI-high, and BRAF mutation. In summary, our results suggest that concomitant loss of CDX2 and SATB2 is a prognostic biomarker but isolated loss of CDX2 or SATB2 is not a prognostic biomarker for stage III CRCs.

Astrocytes of the Anterior Commissure Regulate the Axon Guidance Pathways of Newly Generated Neocortical Neurons in the Opossum Monodelphis domestica.

In marsupials, upper-layer cortical neurons derived from the progenitors of the subventricular zone of the lateral ventricle (SVZ) mature morphologically and send their axons to form interhemispheric connections through the anterior commissure. In contrast, eutherians have evolved a new extra callosal pathway, the corpus callosum, that interconnects both hemispheres. In this study, we aimed to examine neurogenesis during the formation of cortical upper layers, including their morphological maturation in a marsupial species, namely the opossum (Monodelphis domestica). Furthermore, we studied how the axons of upper layers neurons pass through the anterior commissure of the opossum, which connects neocortical areas. We showed that upper-layer II/III neurons were generated within at least seven days in the opossum neocortex. Surprisingly, these neurons expressed special AT-rich sequence binding protein 2 (Satb2) and neuropilin 1 interacting protein (Nrp1), which are proteins known to be essential for the formation of the corpus callosum in eutherians. This indicates that extrinsic, but not intrinsic, cues could be key players in guiding the axons of newly generated cortical neurons in the opossum. Although oligodendrocyte precursor cells were present in the neocortex and anterior commissure, newly generated upper-layer neurons sent unmyelinated axons to the anterior commissure. We also found numerous GFAP-expressing progenitor cells in both brain structures, the neocortex and the anterior commissure. However, at P12-P17 in the opossums, a small population of astrocytes was observed only in the midline area of the anterior commissure. We postulate that in the opossum, midline astrocytes allow neocortical axons to be guided to cross the midline, as this structure resembles the glial wedge required by fibers to cross the midline area of the corpus callosum in the rodent.

Loss of SATB2 and CDX2 expression is associated with DNA mismatch repair protein deficiency and BRAF mutation in colorectal cancer.

The relationship between the expression of the SATB2 and CDX2 proteins and common molecular changes and clinical prognosis in colorectal cancer (CRC) still needs further clarification. We collected 1180 cases of CRC and explored the association between the expression of SATB2 and CDX2 and clinicopathological characteristics, molecular alterations, and overall survival of CRC using whole-slide immunohistochemistry. Our results showed that negative expression of SATB2 and CDX2 was more common in MMR-protein-deficient CRC than in MMR-protein-proficient CRC (15.8% vs. 6.0%, P = 0.001; 14.5% vs. 4.0%, P = 0.000, respectively). Negative expression of SATB2 and CDX2 was more common in BRAF-mutant CRC than in BRAF wild-type CRC (17.2% vs. 6.1%, P = 0.003; 13.8% vs. 4. 2%; P = 0.004, respectively). There was no relationship between SATB2 and/or CDX2 negative expression and KRAS, NRAS, and PIK3CA mutations. The lack of expression of SATB2 and CDX2 was associated with poor histopathological features of CRC. In multivariate analysis, negative expression of SATB2 (P = 0.030), negative expression of CDX2 (P = 0.043) and late clinical stage (P = 0.000) were associated with decreased overall survival of CRC. In conclusion, the lack of SATB2 and CDX2 expression in CRC was associated with MMR protein deficiency and BRAF mutation, but not with KRAS, NRAS and PIK3CA mutation. SATB2 and CDX2 are prognostic biomarkers in patients with CRC.

Microfracture technique combined with mesenchymal stem cells inducer represses miR-708-5p to target special at-rich sequence-binding protein 2 to drive cartilage repair and regeneration in rabbit knee osteoarthritis.

Knee osteoarthritis (KOA) is a degenerative joint illness which leads to knee pain and functional limitation. In this study, we combined microfracture surgery with kartogenin (KGN), a small bioactive molecule used to promote the differentiation of mesenchymal stem cells (MSCs), and explored its impact on cartilage repair and possible latent mechanisms of action. The research offers a brand-new idea for the clinical cure of KOA. The microfracture technique in combination with KNG treatment was performed on a rabbit model of KOA. Animal behaviour was evaluated after the intra-articular injection of miR-708-5p and Special AT-rich sequence binding protein 2 (SATB2) lentiviruses. Later, the expression of the tumour necrosis factor α (TNF-α) and interleukin- 1 (IL-1), the pathology of synovial tissue and cartilage tissue, and the positive cartilage type II collagen, MMP-1, MMP-3 and TIMP-1 were detected. Finally, a luciferase assay was conducted to verify the interaction of miR-708-5p and SATB2. Our results showed that miR-708-5p was elevated in the rabbit KOA model; however, the expression of SATB2 was reduced. Meanwhile, the microfracture technology combined with MSCs inducer KGN drove cartilage repair and regeneration in rabbit KOA by repressing the miR-708-5p expression. We also found that miR-708-5p directly targeted the SATB2 mRNA to regulate its expression. Furthermore, our data urged that elevating miR-708-5p or restraining SATB2 may reverse the therapeutic effect of the microfracture technique combined with MSCs inducer on rabbit KOA. Microfracture technique combined with MSCs inducer represses miR-708-5p to target SATB2 to drive cartilage repair and regeneration in rabbit KOA. This indicates that the microfracture technique combined with MSCs inducers is supposed to be an effective latent method for osteoarthritis cure.

MicroRNA-218 regulates neuronal radial migration and morphogenesis by targeting Satb2 in developing neocortex.

Neuronal migration and morphogenesis are fundamental processes for cortical development. Their defects may cause abnormities in neural circuit formation and even neuropsychiatric disorders. Many proteins, especially layer-specific transcription factors and adhesion molecules, have been reported to regulate the processes. However, the involvement of non-coding RNAs in cortical development has not been extensively studied. Here, we identified microRNA-218 (miR-218) as a layer V-specific microRNA in mouse brains. Expression of miR-218 was elevated in patients with autism spectrum disorder (ASD) and schizophrenia. We found in this study that miR-218 overexpression in developing mouse cortex led to severe defects in radial migration, morphogenesis, and spatial distribution of the cortical neurons. Moreover, we identified Satb2, an upper-layer marker, as a molecular target repressed by miR-218. These results suggest an underlying mechanism of miR-218 involvement in neuropsychiatric disorders, and the interactions of layer-specific non-coding RNAs and proteins in regulating cortical development.

Psammomatoid Ossifying Fibroma Is Defined by SATB2 Rearrangement.

Psammomatoid ossifying fibroma (PsOF), also known as juvenile PsOF, is a benign fibro-osseous neoplasm predominantly affecting the extragnathic bones, particularly the frontal and ethmoid bones, with a preference for adolescents and young adults. The clinical and morphologic features of PsOF may overlap with those of other fibro-osseous lesions, and additional molecular markers would help increase diagnostic accuracy. Because identical chromosomal breakpoints at bands Xq26 and 2q33 have been described in 3 cases of PsOF located in the orbita, we aimed to identify the exact genes involved in these chromosomal breakpoints and determine their frequency in PsOF using transcriptome sequencing and fluorescence in situ hybridization (FISH). We performed whole RNA transcriptome sequencing on frozen tissue in 2 PsOF index cases and identified a fusion transcript involving SATB2, located on chromosome 2q33.1, and AL513487.1, located on chromosome Xq26, in one of the cases. The fusion was validated using reverse transcription (RT)-PCR and SATB2 FISH. The fusion lead to a truncated protein product losing most of the functional domains. Subsequently, we analyzed an additional 24 juvenile PsOFs, 8 juvenile trabecular ossifying fibromas (JTOFs), and 11 cemento-ossifying fibromas (COFs) for SATB2 using FISH and found evidence of SATB2 gene rearrangements in 58% (7 of 12) of the evaluable PsOF cases but not in any of the evaluable JTOF (n = 7) and COF (n = 7) cases. A combination of SATB2 immunofluorescence and a 2-color SATB2 FISH in our index case revealed that most tumor cells harboring the rearrangement lacked SATB2 expression. Using immunohistochemistry, 65% of PsOF, 100% of JTOF, and 100% of COF cases showed moderate or strong staining for SATB2. In these cases, we observed a mosaic pattern of expression with >25% of the spindle cells in between the bone matrix, with osteoblasts and osteocytes being positive for SATB2. Interestingly, 35% (8 of 23) of PsOFs, in contrast to JTOFs and COFs, showed SATB2 expression in <5% of cells. To our knowledge, this is the first report that shows the involvement of SATB2 in the development of a neoplastic lesion. In this study, we have showed that SATB2 rearrangement is a recurrent molecular alteration that appears to be highly specific for PsOF. Our findings support that PsOF is not only morphologically and clinically but also genetically distinct from JTOF and COF.

LncRNA SATB2-AS1 overexpression represses the development of hepatocellular carcinoma through regulating the miR-3678-3p/GRIM-19 axis.

Hepatocellular carcinoma (HCC) is a malignancy worldwide with one of the worst prognoses. Emerging studies have revealed that long noncoding RNAs (lncRNAs) contribute to HCC progression. This research probes the expression and regulatory effect of lncRNA SATB2-AS1 on HCC development. Reverse transcription-polymerase chain reaction (RT-PCR) was applied to measure the SATB2-AS1 profile in HCC tissues and adjacent non-tumor tissues. The impact of SATB2-AS1, miR-3678-3p, or GRIM-19 on HCC cell proliferation, growth, migration, invasion, and apoptosis was determined by gain- and loss-of-function experiments. The results revealed that SATB2-AS1 was downregulated in HCC tissues, and its lower levels were related to higher tumor staging and poorer prognosis of HCC patients. SATB2-AS1 overexpression repressed HCC cell proliferation, induced G1 arrest, and apoptosis, and inhibited migration, invasion, and epithelial-mesenchymal transition (EMT). Mechanistically, SATB2-AS1 inactivated STAT3/HIF-1α and strengthened GRIM-19 expression. After knocking down GRIM-19 with small interfering RNA (siRNA), the malignant phenotypes of HCC cells were enhanced. Further bioinformatics analysis showed that miR-3678-3p was targeted by SATB2-AS1. The dual-luciferase reporter assay, RNA immunoprecipitation (RIP) experiment, and Fluorescence in situ Hybridization (FISH) test confirmed that SATB2-AS1 sponged miR-3678-3p and the latter targeted GRIM-19. The rescue experiments showed that miR-3678-3p aggravated the malignant behaviors of HCC cells, whereas SATB2-AS1 overexpression reversed miR-3678-3p-mediated effects. Inhibition STAT3 promoted SATB2-AS1 and GRIM-19 expression, and reduced miR-3678-3p level. Activation STAT3 exerted opposite effects. Overall, this study confirmed that SATB2-AS1 is a potential prognostic biomarker for HCC and regulates HCC devolvement by regulating the miR-3678-3p/GRIM-19/STAT3/HIF-1α pathway.

Craniofacial and dental characteristics of three Japanese individuals with genetically diagnosed SATB2-associated syndrome.

Craniofacial defects are one of the most frequent phenotypes in syndromic diseases. More than 30% of syndromic diseases are associated with craniofacial defects, which are important for the precise diagnosis of systemic diseases. Special AT-rich sequence-binding protein 2 (SATB2)-associated syndrome (SAS) is a rare syndromic disease associated with a wide variety of phenotypes, including intellectual disability and craniofacial defects. Among them, dental anomalies are the most frequently observed phenotype and thus becomes an important diagnostic criterion for SAS. In this report, we demonstrate three Japanese cases of genetically diagnosed SAS with detailed craniofacial phenotypes. The cases showed multiple dental problems, which have been previously reported to be linked to SAS, including abnormal crown morphologies and pulp stones. One case showed a characteristic enamel pearl at the root furcation. These phenotypes add new insights for differentiating SAS from other disorders.

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.

Increased GS-II lectin binding and SATB2 downregulation are biological features for sessile serrated lesions and microvesicular hyperplastic polyps.

Sessile serrated lesions (SSLs) and microvesicular hyperplastic polyps (MVHPs) are colorectal lesions displaying gastric differentiation. Griffonia simplicifolia-II (GS-II) is a lectin specific to terminal α/ßGlcNAc residues. Here, we assessed GS-II binding and performed immunostaining for HIK1083 (specific to terminal αGlcNAc residues), MUC5AC, MUC6, and special AT-rich sequence binding protein 2 (SATB2) in SSLs, MVHPs, and tubular adenomas (TAs). We observed MUC5AC positivity in 28 of 30 SSLs, but in only three of 23 TAs. Moreover, 24 of 30 SSLs were MUC6-positive, while none of the 23 TAs were MUC6-positive. None of the 30 SSLs or 23 TAs showed HIK1083 positivity. All 30 SSLs and 26 MVHPs were GS-II-positive, while only seven of 23 were in TAs. GS-II staining was mainly distributed in the Golgi region, but SSLs and MVHPs showed goblet cell distribution, in 20 of 30 and 19 of 26 cases, respectively. All SSLs, MVHPs, and TAs were SATB2-positive, but 21 of 30 SSLs and 12 of 26 MVHPs showed decreased staining intensity relative to adjacent mucosa, a decrease seen in only two of 23 in TAs. These results indicate overall that increased terminal ßGlcNAc and decreased SATB2 expression are characteristics of SSLs and MVHPs.

Mechanism of miRNA-31 Regulating Wnt/ß-catenin Signaling Pathway by Targeting Satb2 in the Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells.

OBJECTIVE: To explore the expression of miR-31 and Satb2 gene in the serum of postmenopausal women with osteoporosis (OP). METHODS: 97 postmenopausal women with OP and 100 healthy women were selected as research subjects. MSCs were purchased from Shanghai Zhong Qiao Xin Zhou Biotechnology Co., Ltd. Bone marrow-derived mesenchymal stem cells (BMSCs) were isolated, identified and transfected, and then quantified by alkaline phosphatase (ALP) levels. The expression levels of miR-31 and Satb2 gene mRNA were determined by qRT-PCR. The proteins of RUNX2, OCN and BMP and Wnt/ß-catenin pathway-related proteins (GSK-3, Frizzled 1, Lrp5, Lrp6 and ß-catenin) were tested by Western blotting. RESULTS: In the OP group, the relative expression of miR-31 was 3.61±0.54, significantly higher than that (1.75±0.27) in the healthy control group (t=9.422, P<0.001). The relative expression of mRNA of Satb2 gene was 0.86±0.12, significantly lower than that (1.35±0.21) in the healthy control group (t=5.897, P<0.001). CONCLUSIONS: The increase in miR-31 expression can down-regulate the Wnt/ß-catenin pathway by targeting the expression of Satb2 gene, thereby inhibiting the osteogenic differentiation of BMSCs. This provides an important reference for further understanding the mechanism of OP and identifying targets for early diagnosis and treatment.

VPI Management in SATB2 Syndrome: Use of MRI to Evaluate Anatomy and Physiology in Non-Cleft VPI.

This clinical case study describes the velopharyngeal anatomy and physiology in a patient who presented with SATB2-associated syndrome (SAS) and velopharyngeal insufficiency (VPI) in the absence of an overt cleft palate. The clinical presentation, treatment, outcome, and the contribution of anatomical findings from MRI to surgical treatment planning for this rare genetic disorder, SAS, are described. This case study contributes to our current understanding of the anatomy and physiology of the velopharyngeal mechanism in an individual born with SAS and non-cleft VPI. It also details the changes following bilateral buccal myomucosal flaps in this patient.

Chronic alcohol exposure induces hepatocyte damage by inducing oxidative stress, SATB2 and stem cell-like characteristics, and activating lipogenesis.

Alcohol is a risk factor for hepatocellular carcinoma (HCC). However, the molecular mechanism by which chronic alcohol consumption contributes to HCC is not well understood. The purpose of the study was to demonstrate the effects of chronic ethanol exposure on the damage of human normal hepatocytes. Our data showed that chronic exposure of hepatocytes with ethanol induced changes similar to transformed hepatocytes that is, exhibited colonies and anchorage-independent growth. These damaged hepatocytes contained high levels of reactive oxygen species (ROS) and showed induction of the SATB2 gene. Furthermore, damaged hepatocytes gained the phenotypes of CSCs which expressed stem cell markers (CD133, CD44, CD90, EpCAM, AFP and LGR5), and pluripotency maintaining factors (Sox-2, POU5F1/Oct4 and KLF-4). Ethanol exposure also induced Nanog, a pluripotency maintaining transcription factor that functions in concert with Oct4 and SOX-2. Furthermore, ethanol induced expression of EMT-related transcription factors (Snail, Slug and Zeb1), N-Cadherin, and inhibited E-cadherin expression in damaged hepatocytes. Ethanol enhanced recruitment of SATB2 to promoters of Bcl-2, Nanog, c-Myc, Klf4 and Oct4. Ethanol also induced activation of the Wnt/TCF-LEF1 pathway and its targets (Bcl-2, Cyclin D1, AXIN2 and Myc). Finally, ethanol induced hepatocellular steatosis, SREBP1 transcription, and modulated the expression of SREBP1c, ACAC, ACLY, FASN, IL-1ß, IL-6, TNF-α, GPC3, FLNB and p53. These data suggest that chronic alcohol consumption may contribute towards the development of HCC by damaging normal hepatocytes with the generation of inflammatory environment, induction of SATB2, stem cell-like characteristics, and cellular steatosis.