SOX10 Mutations Research Articles

Red2Flpe-SCON: a versatile, multicolor strategy for generating mosaic conditional knockout mice

Image-based lineage tracing enables tissue turnover kinetics and lineage potentials of different adult cell populations to be investigated. Previously, we reported a genetic mouse model system, Red2Onco, which ectopically expressed mutated oncogenes together with red fluorescent proteins (RFP). This system enabled the expansion kinetics and neighboring effects of oncogenic clones to be dissected. We now report Red2Flpe-SCON: a mosaic knockout system that uses multicolor reporters to label both mutant and wild-type cells. We develop the Red2Flpe mouse line for red clone-specific Flpe expression, as well as the FRT-based SCON (Short Conditional IntrON) method to facilitate tunable conditional mosaic knockouts in mice. We use the Red2Flpe-SCON method to study Sox2 mutant clonal analysis in the esophageal epithelium of adult mice which reveal that the stem cell gene, Sox2, is less essential for adult stem cell maintenance itself, but rather for stem cell proliferation and differentiation.

A novel SOX10 mutation causing Waardenburg syndrome type 2 by expressing a truncated and dysfunctional protein in a Chinese child.

This study aimed to identify the causative variants in a patient with Waardenburg syndrome (WS) type 2 using whole exome sequencing (WES). The clinical features of the patient were collected. WES was performed on the patient and his parents to screen causative genetic variants and Sanger sequencing was performed to validate the candidate mutation. The AlphaFold2 software was used to predict the changes in the 3D structure of the mutant protein. Western blotting and immunocytochemistry were used to determine the SOX10 mutant in vitro. A de novo variant of SOX10 gene, NM_006941.4: c.707_714del (p. H236Pfs*42), was identified, and it was predicted to disrupt the wild-type DIM/HMG conformation in SOX10. In-vitro analysis showed an increased level of expression of the mutant compared to the wild-type. Our findings helped to understand the genotype-phenotype association in WS2 cases with SOX10 mutations.

Prenatal Diagnosis of Fetal Micrognathia at 11-20 Weeks of Gestation: A Prospective Observation Study.

To prospectively evaluate the prognosis of fetuses diagnosed with micrognathia using prenatal ultrasound screening. Between January 2019 and December 2022, a normal range of IFA to evaluate the facial profile in fetuses with micrognathia in a Chinese population between 11 and 20 gestational weeks was established, and the pregnancy outcomes of fetal micrognathia were described. The medical records of these pregnancies were collected, including family history, maternal demographics, sonographic findings, genetic testing results, and pregnancy outcomes. Ultrasound identified 25 patients with fetal micrognathia, with a mean IFA value of 43.6°. All cases of isolated fetal micrognathia in the initial scans were non-isolated in the following scans. A total of 78.9% (15/19) cases had a genetic cause confirmed, including 12 with chromosomal abnormalities and 3 with monogenic disorders. Monogenic disorders were all known causes of micrognathia, including two cases of campomelic dysplasia affected by SOX9 mutations and one case of mandibulofacial dysostosis with an EFTUD2 mutation. In the end, 19 cases were terminated, 1 live birth was diagnosed as Pierre Robin syndrome, and 5 cases were lost to follow-up. IFA is a useful indicator and three-dimensional ultrasound is a significant support technique for fetal micrognathia prenatal diagnosis. Repeat ultrasound monitoring and genetic testing are crucial, with CMA recommended and Whole exome sequencing performed when normal arrays are reported. Isolated fetal micrognathia may be an early manifestation of monogenic disorders.

Clinical Significance of SOX10 Expression in Human Pathology.

The embryonic development of neural crest cells and subsequent tissue differentiation are intricately regulated by specific transcription factors. Among these, SOX10, a member of the SOX gene family, stands out. Located on chromosome 22q13, the SOX10 gene encodes a transcription factor crucial for the differentiation, migration, and maintenance of tissues derived from neural crest cells. It plays a pivotal role in developing various tissues, including the central and peripheral nervous systems, melanocytes, chondrocytes, and odontoblasts. Mutations in SOX10 have been associated with congenital disorders such as Waardenburg-Shah Syndrome, PCWH syndrome, and Kallman syndrome, underscoring its clinical significance. Furthermore, SOX10 is implicated in neural and neuroectodermal tumors, such as melanoma, malignant peripheral nerve sheath tumors (MPNSTs), and schwannomas, influencing processes like proliferation, migration, and differentiation. In mesenchymal tumors, SOX10 expression serves as a valuable marker for distinguishing between different tumor types. Additionally, SOX10 has been identified in various epithelial neoplasms, including breast, ovarian, salivary gland, nasopharyngeal, and bladder cancers, presenting itself as a potential diagnostic and prognostic marker. However, despite these associations, further research is imperative to elucidate its precise role in these malignancies.

PATH-02. NOVEL SOX10 INDEL MUTATIONS DRIVE SCHWANNOMAS THROUGH IMPAIRED TRANSACTIVATION OF MYELINATION GENE PROGRAMS

Abstract Schwannomas are common peripheral nerve sheath tumors that can cause severe morbidity due to their stereotypic intracranial and paraspinal locations. However, the molecular drivers responsible for a substantial subset remain unknown. Through genomic profiling of 96 schwannomas, we identified novel in-frame insertion/deletion mutations in the SOX10 gene in 29% of sporadic tumors which uniformly lacked alterations in known nerve sheath tumor genes including NF1, NF2, LZTR1, and SMARCB1. These indel mutations clustered at the C-terminal end of the HMG-box domain, the DNA binding motif of the SOX10 transcription factor critical for Schwann cell differentiation. Schwannomas arising from non-vestibular cranial nerves (e.g. facial, trigeminal, vagus) were highly enriched for SOX10 mutations, whereas the vast majority of vestibular schwannomas had NF2 inactivation. DNA methylation profiling revealed that SOX10 mutant schwannomas clustered together with schwannomas harboring NF2 mutation or SH3PXD2A-HTRA1 fusion, indicating that SOX10 indel mutations define a novel schwannoma molecular subtype and not a distinct nerve sheath tumor entity. To investigate the mechanism by which SOX10 indel mutations promote schwannoma development, we stably transduced human fetal glial cells with either wildtype SOX10 or two different tumor-derived insertion mutants. RNA sequencing revealed that both SOX10 indel mutants, in contrast to wildtype SOX10, failed to activate expression of myelination and glial differentiation gene programs, including PMP2 which encodes the major peripheral myelin protein in mature Schwann cells. Electrophoretic mobility shift assay revealed that the indel mutants retained their DNA binding capacity to the SOX10 binding site in the PMP2 promoter, while a luciferase reporter assay revealed transactivation at the PMP2 promoter by wildtype SOX10 but not by the mutants. In summary, we identified a new recurrent genetic event in 29% of sporadic schwannomas that we speculate drives schwannoma development through impaired transactivation of myelination gene expression programs causing blocked differentiation of immature Schwann cells.

Hirschsprung's Disease - Review of Clinical Features, Diagnosis and Treatment

Introduction and purpose: Hirschsprung's disease, also known as congenital aganglionic megacolon, is a rare congenital disorder that affects the large intestine. Due to the absence of ganglion cells, the affected segment of the colon becomes narrow and unable to relax. The disease is present from birth but may not always be immediately apparent. In this paper, we will attempt to present the current state of knowledge regarding the diagnosis and treatment of Hirschsprung's disease, based on the analysis of literature available on the PubMed platform.
 Description of the state of knowledge: Hirschsprung's disease (HSCR), also known as congenital aganglionosis of the colon, involves abnormal migration, proliferation, and differentiation of neural crest cells, leading to the absence of autonomic nerve ganglia within the colon. HSCR is associated with mutations in several genes, with RET, GDNF, EDNRB and SOX10 being identified as the main causes of the disease. Mutations in the RET gene are associated with the hereditary form of Hirschsprung's disease. Symptoms of HSCR appear in newborns and may include bilious vomiting, diarrhea associated with enterocolitis, failure to pass meconium within the first 24 hours of life, impaired peristalsis, jaundice, feeding difficulties, and progressive abdominal distension.
 Summary: Diagnosis is typically made based on clinical presentation, imaging studies, and biopsy. Treatment usually involves surgery to remove the affected segment of the colon and reconnect the healthy portions. Although postoperative complications are relatively common, long-term studies suggest that the majority of children with Hirschsprung's disease function well in society.

Novel SOX10 indel mutations drive schwannomas through impaired transactivation of myelination gene programs.

Schwannomas are common peripheral nerve sheath tumors that can cause severe morbidity given their stereotypic intracranial and paraspinal locations. Similar to many solid tumors, schwannomas and other nerve sheath tumors are primarily thought to arise due to aberrant hyperactivation of the RAS growth factor signaling pathway. Here, we sought to further define the molecular pathogenesis of schwannomas. We performed comprehensive genomic profiling on a cohort of 96 human schwannomas, as well as DNA methylation profiling on a subset. Functional studies including RNA sequencing, chromatin immunoprecipitation-DNA sequencing, electrophoretic mobility shift assay, and luciferase reporter assays were performed in a fetal glial cell model following transduction with wildtype and tumor-derived mutant isoforms of SOX10. We identified that nearly one-third of sporadic schwannomas lack alterations in known nerve sheath tumor genes and instead harbor novel recurrent in-frame insertion/deletion mutations in SOX10, which encodes a transcription factor responsible for controlling Schwann cell differentiation and myelination. SOX10 indel mutations were highly enriched in schwannomas arising from nonvestibular cranial nerves (eg facial, trigeminal, vagus) and were absent from vestibular nerve schwannomas driven by NF2 mutation. Functional studies revealed these SOX10 indel mutations have retained DNA binding capacity but impaired transactivation of glial differentiation and myelination gene programs. We thus speculate that SOX10 indel mutations drive a unique subtype of schwannomas by impeding proper differentiation of immature Schwann cells.

Molecular typing and mutational characterization of rectal neuroendocrine neoplasms.

Rectal neuroendocrine neoplasms (NENs) are rare neoplasms with limited understanding of its genomic alterations and molecular typing. The paraffin-embedded tissue specimens of 38 patients with rectal NENs after surgery were subjected to whole gene sequencing (WGS), and mutation profilings were drawn to identify high-frequency mutation genes, copy-number variations (CNVs), tumor mutation burden (TMB), signal pathways, mutation signatures, DNA damage repair (DDR) genes, and molecular types. The differences of mutated genes and signaling pathways in different pathological grades and metastatic/non-metastatic groups were compared. It helped to search for potential targets. C > T and T > C transitions are the most common base substitutions in rectal NENs. DNA mismatch repair deficiency, DNA base modifications, smoking and exposure to ultraviolet light might play a role in the occurrence of rectal NENs. DAXX, KMT2C, BCL2L1, LTK, MERTK, SPEN, PKN1, FAT3, and LRP2 mutations were found in only low-grade rectal NETs, whereas APC, TP53, NF1, SOX9, and BRCA1 mutations were common in high-grade rectal NECs/MiNENs. These genes helped in distinguishing poorly-differentiated or well-differentiated rectal NENs. Alterations in P53, Wnt and TGFβ signaling pathways were more pronounced in rectal NECs and MiNENs. Alterations in Wnt, MAPK and PI3K/AKT signaling pathways promoted metastases. Rectal NENs were classified into two molecular subtypes by cluster analysis based on the mutant genes and signaling pathways combined with clinicopathological features. Patients with mutations in the LRP2, DAXX, and PKN1 gene showed a trend of well-differentiated and early-stage tumors with less metastasis (p = 0.000). This study evaluated risk factors for regional lymphatic and/or distant metastases, identified high-frequency mutated genes, mutation signatures, altered signaling pathways through NGS. Rectal NENs were divided into two molecular types. This helps to evaluate the likelihood of metastasis, formulate follow-up strategies for patients and provide a target for future research on precision treatment of rectal NENs. PARP inhibitors, MEK inhibitors, mTOR/AKT/PI3K and Wnt signaling pathway inhibitors may be effective drugs for the treatment of metastatic rectal NENs.

SOX2 is essential for astrocyte maturation and its deletion leads to hyperactive behavior in mice.

Children with SOX2 deficiency develop ocular disorders and extra-ocular CNS anomalies. Animal data show that SOX2 is essential for retinal and neural stem cell development. In the CNS parenchyma, SOX2 is primarily expressed in astroglial and oligodendroglial cells. Here, we report a crucial role of astroglial SOX2 in postnatal brain development. Astroglial Sox2-deficient mice develop hyperactivity in locomotion and increased neuronal excitability in the corticostriatal circuit. Sox2 deficiency inhibits postnatal astrocyte maturation molecularly, morphologically, and electrophysiologically without affecting astroglia proliferation. Mechanistically, SOX2 directly binds to a cohort of astrocytic signature and functional genes, the expression of whichissignificantly reduced in Sox2-deficient CNS and astrocytes. Consistently, Sox2 deficiency remarkably reduces glutamate transporter expression and compromised astrocyte function of glutamate uptake.Our study provides insights into the cellular mechanisms underlying brain defects in children with SOX2 mutations and suggests a link of astrocyte SOX2 with extra-ocular abnormalities in SOX2-mutant subjects.

Control of cranial ectomesenchyme fate by Nr2f nuclear receptors.

Certain cranial neural crest cells are uniquely endowed with the ability to make skeletal cell types otherwise only derived from mesoderm. As these cells migrate into the pharyngeal arches, they downregulate neural crest specifier genes and upregulate so-called ectomesenchyme genes that are characteristic of skeletal progenitors. Although both external and intrinsic factors have been proposed as triggers of this transition, the details remain obscure. Here, we report the Nr2f nuclear receptors as intrinsic activators of the ectomesenchyme program: zebrafish nr2f5 single and nr2f2;nr2f5 double mutants show marked delays in upregulation of ectomesenchyme genes, such as dlx2a, prrx1a, prrx1b, sox9a, twist1a and fli1a, and in downregulation of sox10, which is normally restricted to early neural crest and non-ectomesenchyme lineages. Mutation of sox10 fully rescued skeletal development in nr2f5 single but not nr2f2;nr2f5 double mutants, but the initial ectomesenchyme delay persisted in both. Sox10 perdurance thus antagonizes the recovery but does not explain the impaired ectomesenchyme transition. Unraveling the mechanisms of Nr2f function will help solve the enduring puzzle of how cranial neural crest cells transition to the skeletal progenitor state.

A comprehensive genotype–phenotype evaluation of eight Chinese probands with Waardenburg syndrome

BackgroundWaardenburg syndrome (WS) is the most common form of syndromic deafness with phenotypic and genetic heterogeneity in the Chinese population. This study aimed to clarify the clinical characteristics and the genetic cause in eight Chinese WS families (including three familial and five sporadic cases). Further genotype–phenotype relationships were also investigated.MethodsAll probands underwent screening for the known WS-related genes including PAX3, SOX10, MITF, EDNRB, EDN3, and SNAI2 using next-generation sequencing to identify disease-causing genes. Further validation using Sanger sequencing was performed. Relevant findings for the associated genotype–phenotype from previous literature were retrospectively analyzed.ResultDisease-causing variants were detected in all eight probands by molecular genetic analysis of the WS genes (SOX10(NM_006941.4): c.544_557del, c.553 C > T, c.762delA, c.336G > A; MITF(NM_000248.3): c.626 A > T; PAX3(NM_181459.4): c.838delG, c.452-2 A > G, c.214 A > G). Six mutations (SOX10:c.553 C > T, c.544_557del, c.762delA; PAX3: c.838delG, c.214 A > G; MITF:c.626 A > T) were first reported. Clinical evaluation revealed prominent phenotypic variability in these WS patients. Twelve WS1 cases and five WS2 cases were diagnosed in total. Two probands with SOX10 mutations developed progressive changes in iris color with age, returning from pale blue at birth to normal tan. Additionally, one proband had a renal malformation (horseshoe kidneys).All cases were first described as WS cases. Congenital inner ear malformations were more common, and semicircular malformations were exclusively observed in probands with SOX10 mutations. Unilateral hearing loss occurred more often in cases with PAX3 mutations.ConclusionOur findings helped illuminate the phenotypic and genotypic spectrum of WS in Chinese populations and could contribute to better genetic counseling of WS.

Establishment of an iPSC line (CPGHi005-A) from a patient with Waardenburg syndrome carrying a heterozygous SVA-F retrotransposon insertion into SOX10

Mutations of SOX10 result in Waardenburg syndrome characterized by sensorineural hearing loss and pigmentary abnormalities, which can be found in association with a defect of migrating neural crest cells. The role of SINE-VNTR-Alu (SVA) retrotransposon insertions in disorders has only been minimally explored and there have been no reports of WS cases related to SVA retrotransposons. Here, we report the successful establishment and characterization of an iPSC line from a patient diagnosed with Waardenburg syndrome carrying an insertion of SVA in intron 2 of SOX10.

Deconstructing Sox2 Function in Brain Development and Disease.

SOX2 is a transcription factor conserved throughout vertebrate evolution, whose expression marks the central nervous system from the earliest developmental stages. In humans, SOX2 mutation leads to a spectrum of CNS defects, including vision and hippocampus impairments, intellectual disability, and motor control problems. Here, we review how conditional Sox2 knockout (cKO) in mouse with different Cre recombinases leads to very diverse phenotypes in different regions of the developing and postnatal brain. Surprisingly, despite the widespread expression of Sox2 in neural stem/progenitor cells of the developing neural tube, some regions (hippocampus, ventral forebrain) appear much more vulnerable than others to Sox2 deletion. Furthermore, the stage of Sox2 deletion is also a critical determinant of the resulting defects, pointing to a stage-specificity of SOX2 function. Finally, cKOs illuminate the importance of SOX2 function in different cell types according to the different affected brain regions (neural precursors, GABAergic interneurons, glutamatergic projection neurons, Bergmann glia). We also review human genetics data regarding the brain defects identified in patients carrying mutations within human SOX2 and examine the parallels with mouse mutants. Functional genomics approaches have started to identify SOX2 molecular targets, and their relevance for SOX2 function in brain development and disease will be discussed.

Target Search Dynamics of Sox Transcription Factors

Here we investigate the impact of regions outside of the DNA‐binding domain (DBD) on target search efficiency of transcription factors (TFs). In living organisms, TFs are key for gene regulation by binding sequence DNA‐binding sites. The facilitated diffusion theory proposes a search process combining TF 1D sliding on DNA and 3D diffusion in the nucleus. Moreover, the local non‐specific TF‐DNA interactions mediated by electrostatic forces enhance the target search efficiency to reach on‐rates faster than allowed by free diffusion. While such theoretical models fit TF behaviors in prokaryotes, how TFs search the chromatinized eukaryotic genome is poorly understood. More importantly, the relevance of regions outside of the DNA‐binding domain for the search process remains to be clarified.We hypothesize that positive charges flanking the DBD accelerate TF target search by interacting non‐specifically with negatively charged DNA. We tackle this hypothesis with a comparative study between Sox2 and Sox17. While recognizing the same DNA motif, Sox2 displays higher non‐specific binding affinity, which we think is caused by a higher content in positive charges close to the DBD.To probe the kinetics of in vivo Sox‐DNA interactions in living mouse embryonic stem cells, we used highly inclined and laminated optical sheet (HiLo) microscopy. We determined that Sox2 and Sox17 have similar profiles of residence time with specific binding of ~ 12 s and non‐specific binding of ~ 0.7 s. We then quantified the search efficiency of Sox2 and Sox17 by determining their pseudo on‐rate, which we define as the time‐averaged number of specifically bound particles per time interval and per TF concentration. Since Sox2 and Sox17 bind to the same DNA motifs, they thus have the same number of targets in the mouse genome. Therefore, the pseudo on‐rate scales linearly with association rate at a given TF concentration. We found that Sox2 has a two‐fold higher pseudo on‐rate than Sox17. We also generated a Sox2 mutant in which its DBD flanking region was swapped with the one from Sox17. This led to a two‐fold decrease in pseudo on‐rate as compared to the wild‐type Sox2. These results thus directly support the hypothesis that non‐specific electrostatic interactions of positively charged residues in regions flanking the DBD enhance their DNA association rates.One limitation of in vivo experiments is that the chromatin context in which TF‐DNA interactions are observed is unknown. To dissect the differential interactions of Sox2 and Sox17 with naked versus nucleosomal DNA, we are using chemically‐synthesized in vitro chromatin combined with single‐molecule tracking via total internal reflection (TIRF) microscopy. Since Sox2 but not Sox17 is known as a pioneer factor, quantifying their interactions with chromatinized DNA will shed light on search mechanisms of pioneer TFs in compact chromatin. In that sense, we foresee that more positively‐charged DBD flanking regions may stabilize specific binding of TF to nucleosomal DNA and help TFs to invade and remodel chromatin.Taken together, our combination of in vivo and in vitro single‐molecule imaging techniques allows dissecting how the charge distribution of DBD flanking regions modulates TF target search on chromatin.

The Pathogenesis of Pierre Robin Sequence through a Review of SOX9 and Its Interactions.

Background:The literature does not offer any review of the pathogenesis of the clinical features of syndromes with Pierre Robin sequence (PRS). The senior author (MMA) proposed a hypothesis that SOX9 and its interactions may play a key role in this pathogenesis. The current review aims to test this hypothesis.Methods:Three literature searches were made: the first aimed to document the main syndromes associated with PRS; and the second was to document the main functions of SOX9 in development; and the third was to investigate if SOX9 and its interactions may play a role in the pathogenesis.Results:SOX9 is the main positive regulator in the development of the mandibular cartilage and it also enhances collagen type II (the main collagen type in cartilage) expression in the mandibular cartilage. Furthermore, SOX9 participates in neural crest development, binds to the exon junction complex, and participates in sex determination. The interactions of SOX9 could explain the pathogenesis of the clinical features of syndromic PRS. These included interactions with collagen type II (in Strickler syndrome), exon junction complex (in Richier-Costa–Periera syndrome), glucose (in Catel–Manzke syndrome), RNA-binding proteins (in TARP syndrome), and the spliceosome (in cerebra-costo-mandibular syndrome). Finally, SOX9 mutations cause campomelic dysplasia.Conclusions:The review supports the hypothesis of the participation of SOX9 in the pathogenesis of the clinical features of syndromic and nonsyndromic PRS. This should guide future research on the topic.

Sox10 Gene Is Required for the Survival of Saccular and Utricular Hair Cells in a Porcine Model.

Pathological changes of the cochlea and hearing loss have been well addressed in Waardenburg syndrome (WS). However, the vestibular organ malformation in WS is still largely unknown. In this study, the differentiation and development of vestibular sensory epithelium and vestibular function caused by SOX10 mutation, a critical gene induces WS, have been studied in minature pig model. Degeneration of vestibular hair cells was found in this Sox10 mutation porcine model. Inner ear phenotype of the SOX10+/R109W miniature pigs showed cochlear abnormalities as well as saccular hypofunction. In the mutant pigs, no prominent dissimilarity was shown in the bone structure of the semicircular canals. However, the saccular membrane was collapsed, and the infusion of stereocilia of the hair cells was observed. There were no dark cells in the utricles in the mutant pigs. The density of the utricular hair cells was also significantly lower in the mutant pigs compared to the wild type. Our study demonstrated that the SOX10 gene and melanocytes play important roles in the vestibular organ development. Sox10 mutation disrupts the KIT-DCT signaling pathway, affects the development of melanocytes, and leads to vestibule morphogenesis.

Novel SOX2 mutation in autosomal dominant cataract-microcornea syndrome

BackgroundCongenital cataract-microcornea syndrome (CCMC) is characterized by the association of congenital cataract and microcornea without any other systemic anomaly or dysmorphism. Although several causative genes have been reported in patients with CCMC, the genetic etiology of CCMC is yet to be clearly understood.PurposeTo unravel the genetic cause of autosomal dominant family with CCMC.MethodsAll patients and available family members underwent a comprehensive ophthalmologic clinical examination in the hospital by expert ophthalmologists and carried out to clinically diagnosis. All the patients were screened by whole-exome sequencing and then validated using co-segregation by Sanger sequencing.ResultsFour CCMC patients from a Chinese family and five unaffected family members were enrolled in this study. Using whole-exome sequencing, a missense mutation c.295G > T (p.A99S, NM_003106.4) in the SOX2 gene was identified and validated by segregation analysis. In addition, this missense mutation was predicted to be damaging by multiple predictive tools. Variant p.Ala99Ser was located in a conservation high mobility group (HMG)-box domain in SOX2 protein, with a potential pathogenic impact of p.Ala99Ser on protein level.ConclusionsA novel missense mutation (c.295G > T, p.Ala99Ser) in the SOX2 gene was found in this Han Chinese family with congenital cataract and microcornea. Our study determined that mutations in SOX2 were associated with CCMC, warranting further investigations on the pathogenesis of this disorder. This result expands the mutation spectrum of SOX2 and provides useful information to study the molecular pathogenesis of CCMC.

Enteric nervous system modulation of luminal pH modifies the microbial environment to promote intestinal health.

The enteric nervous system (ENS) controls many aspects of intestinal homeostasis, including parameters that shape the habitat of microbial residents. Previously we showed that zebrafish lacking an ENS, due to deficiency of the sox10 gene, develop intestinal inflammation and bacterial dysbiosis, with an expansion of proinflammatory Vibrio strains. To understand the primary defects resulting in dysbiosis in sox10 mutants, we investigated how the ENS shapes the intestinal environment in the absence of microbiota and associated inflammatory responses. We found that intestinal transit, intestinal permeability, and luminal pH regulation are all aberrant in sox10 mutants, independent of microbially induced inflammation. Treatment with the proton pump inhibitor, omeprazole, corrected the more acidic luminal pH of sox10 mutants to wild type levels. Omeprazole treatment also prevented overabundance of Vibrio and ameliorated inflammation in sox10 mutant intestines. Treatment with the carbonic anhydrase inhibitor, acetazolamide, caused wild type luminal pH to become more acidic, and increased both Vibrio abundance and intestinal inflammation. We conclude that a primary function of the ENS is to regulate luminal pH, which plays a critical role in shaping the resident microbial community and regulating intestinal inflammation.

Truncating SOX9 Alterations Are Heterozygous Null Alleles in Genome-Stable Colorectal Cancer.

Truncating SOX9 Alterations Are Heterozygous Null Alleles in Genome-Stable Colorectal Cancer.

Generation of a heterozygous SOX10 knockout human embryonic stem cell line using CRISPR/Cas9 technology

SOX10 is one of the master transcription factors in neural crest development. Human SOX10 mutations are associated with Waardenburg syndrome type 4 (Waardenburg-Shah, WS4), which can be inherited in both autosomal dominant and recessive patterns. Here, the human embryonic stem cell (hESC) line, H9, was used to generate a heterozygous SOX10 knockout cell line as the in vitro model of WS4 by CRISPR/Cas9-mediated gene targeting. This cell line may represent a valuable tool for uncovering the pathogenesis of WS4.