Sox14 is essential for initiation of interneuron differentiation in the chick spinal cord

The neural tube comprises several different types of progenitors and postmitotic neurons that coordinately act with each other to play integrated functions. Its development consists of two phases: proliferation of progenitor cells and differentiation into postmitotic neurons. How progenitor cells differentiate into each corresponding neuron is an important question for understanding the mechanisms of neuronal development. Here we introduce one of the Sox transcription factors, Sox14, which plays an essential role in the promotion of neuronal differentiation. Sox14 belongs to the SoxB subclass and its expression starts in the progenitor regions before neuronal differentiation is initiated at the trunk level of the neural tube. After neuronal differentiation is initiated, Sox14 expression gradually becomes confined to the V2a region of the neural tube, where Chx10 is co-expressed. Overexpression of Sox14 restricts progenitor cell proliferation. Conversely, the blockade of Sox14 expression by the RNAi strategy inhibits V2a neuron differentiation and causes expansion of the progenitor domain. We further found that Sox14 acted as a transcriptional activator. Taken together, Sox14 acts as a modulator of cell proliferation and an initiator protein for neuronal differentiation in the intermediate region of the neural tube

Light-dependent induction of Edn2 expression and attenuation of retinal pathology by endothelin receptor antagonists in Prominin-1- deficient mice

Retinitis pigmentosa (RP) and macular dystrophy (MD) are prevalent retinal degenerative diseases associated with gradual photoreceptor death. These diseases are often caused by genetic mutations that result in degeneration of the retina postnatally after it has fully developed. The Prominin-1 gene (Prom1) is a causative gene for RP and MD, and Prom1- knockout (KO) mice recapitulate key features of these diseases including light-dependent retinal degeneration and stenosis of retinal blood vessels. The mechanisms underlying progression of such degeneration have remained unknown, however. We here analysed early events associated with retinal degeneration in Prom1-KO mice. We found that photoreceptor cell death and glial cell activation occur between 2 and 3 weeks after birth. High-throughput analysis revealed that expression of the endothelin-2 gene (Edn2) was markedly up-regulated in the Prom1-deficient retina during this period. Expression of Edn2 was also induced by light stimulation in Prom1-KO mice that had been reared in the dark. Finally, treatment with endothelin receptor antagonists attenuated photoreceptor cell death, gliosis, and retinal vessel stenosis in Prom1-KO mice. Our findings suggest that inhibitors of endothelin signalling may delay the progression of RP and MD and therefore warrant further study as potential therapeutic agents for these diseases

Two Secreted Proteoglycans, Activators of Urothelial Cell-Cell Adhesion, Negatively Contribute to Bladder Cancer Initiation and Progression.

Osteomodulin (OMD) and proline/arginine-rich end leucine repeat protein (PRELP) are secreted extracellular matrix proteins belonging to the small leucine-rich proteoglycans family. We found that OMD and PRELP were specifically expressed in umbrella cells in bladder epithelia, and their expression levels were dramatically downregulated in all bladder cancers from very early stages and various epithelial cancers. Our in vitro studies including gene expression profiling using bladder cancer cell lines revealed that OMD or PRELP application suppressed the cancer progression by inhibiting TGF-β and EGF pathways, which reversed epithelial-mesenchymal transition (EMT), activated cell-cell adhesion, and inhibited various oncogenic pathways. Furthermore, the overexpression of OMD in bladder cancer cells strongly inhibited the anchorage-independent growth and tumorigenicity in mouse xenograft studies. On the other hand, we found that in the bladder epithelia, the knockout mice of OMD and/or PRELP gene caused partial EMT and a loss of tight junctions of the umbrella cells and resulted in formation of a bladder carcinoma in situ-like structure by spontaneous breakdowns of the umbrella cell layer. Furthermore, the ontological analysis of the expression profiling of an OMD knockout mouse bladder demonstrated very high similarity with those obtained from human bladder cancers. Our data indicate that OMD and PRELP are endogenous inhibitors of cancer initiation and progression by controlling EMT. OMD and/or PRELP may have potential for the treatment of bladder cancer

Autosomal-Dominant Corneal Endothelial Dystrophies CHED1 and PPCD1 Are Allelic Disorders Caused by Non-coding Mutations in the Promoter of OVOL2

Congenital hereditary endothelial dystrophy 1 (CHED1) and posterior polymorphous corneal dystrophy 1 (PPCD1) are autosomal-dominant corneal endothelial dystrophies that have been genetically mapped to overlapping loci on the short arm of chromosome 20. We combined genetic and genomic approaches to identify the cause of disease in extensive pedigrees comprising over 100 affected individuals. After exclusion of pathogenic coding, splice-site, and copy-number variations, a parallel approach using targeted and whole-genome sequencing facilitated the identification of pathogenic variants in a conserved region of the OVOL2 proximal promoter sequence in the index families (c.−339_361dup for CHED1 and c.−370T>C for PPCD1). Direct sequencing of the OVOL2 promoter in other unrelated affected individuals identified two additional mutations within the conserved proximal promoter sequence (c.−274T>G and c.−307T>C). OVOL2 encodes ovo-like zinc finger 2, a C2H2 zinc-finger transcription factor that regulates mesenchymal-to-epithelial transition and acts as a direct transcriptional repressor of the established PPCD-associated gene ZEB1. Interestingly, we did not detect OVOL2 expression in the normal corneal endothelium. Our in vitro data demonstrate that all four mutated OVOL2 promoters exhibited more transcriptional activity than the corresponding wild-type promoter, and we postulate that the mutations identified create cryptic cis-acting regulatory sequence binding sites that drive aberrant OVOL2 expression during endothelial cell development. Our data establish CHED1 and PPCD1 as allelic conditions and show that CHED1 represents the extreme of what can be considered a disease spectrum. They also implicate transcriptional dysregulation of OVOL2 as a common cause of dominantly inherited corneal endothelial dystrophies

Combination of shear-wave elastography and liver fibrosis markers predicts severe fibrosis in patients with non-alcoholic steatohepatitis

　非アルコール性脂肪性肝疾患（Non-alcoholic fatty liver disease：NAFLD）の中から予後の悪い線維化が進展した非アルコール性脂肪肝炎（Non-alcoholic steatohepatitis：NASH）を非侵襲的診断法にて拾い上げることが重要である．今回，バイオマーカーやshear wave elastography（以下 SWE）を組み合わせた非侵襲的診断における肝線維化進展症例の診断能の向上について検討を行った．肝生検および SWE を施行し，肝線維化マーカーを測定した NAFLD 患者140名を対象とし，SWE 値と肝線維化マーカーの測定を行い線維化進展例（stage3以上）の診断の拾い上げについて検討した．各種線維化マーカーは stage3-4の線維化進展例で有意に上昇を認め，SWE においてはstage2の段階から上昇し，他の線維化マーカーより早い段階から NASH の線維化の診断ができた．SWE，Ⅳ型コラーゲン7S，WFA+M2BP，P-Ⅲ-P，ヒアルロン酸，FIB4 index における stage3以上の AUC はそれぞれ0.86，0.83，0.79，0.75，0.75，0.77であった．さらに SWE と線維化マーカーを組み合わせたところ，AUC はそれぞれ0.92，0.88，0.86，0.88，0.88で診断能の上昇を認めた．特に SWE とⅣ型コラーゲン7S の診断能が最も優れていた．NASH における SWE は簡便に線維化進展の診断が可能であり，バイオマーカーを組み合わせることで肝線維化診断能が上昇した．以上より線維化の軽度な NASH 症例や非アルコール性脂肪肝（Non-alcoholic fatty liver：NAFL）を識別し，肝生検を減少させる可能性があり，NAFLD の予後の改善に繋がると思われた．　In the recent years, the incidence of nonalcoholic fatty liver disease (NAFLD) is increasing rapidly worldwide. It is important to detect nonalcoholic steatohepatitis (NASH) with a poor prognosis in patients with NAFLD using noninvasive diagnostic methods. Conventional ultrasound (US) is the most common, low-cost technique for NASH diagnosis and improving patient prognosis. We studied the usefulness of US elastography (shear-wave elastography [SWE]) in diagnosing liver fibrosis (LF) with NAFLD and examined the possibility of improving the diagnosis of patients with advanced LF by combining SWE and LF-marker testing. The subjects were 140 patients with NAFLD who underwent liver biopsies, SWE, and LF-marker tests, such as type IV collagen 7S, Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA[+]-M2BP), P-Ⅲ-P, hyaluronic acid, and fibrosis-4 (FIB4) index, at the General Medical Center, Kawasaki Medical School. We evaluated the efficacy of combined SWE and LF-marker tests to diagnose advanced LF (stage ≥3). SWE was performed using 3.75-MHz probes (Canon Aplio 500, JAPAN). There were minimal differences in LF-marker levels for NASH stages 0–2, whereas significantly increased LF-marker levels were observed in patients with advanced LF (stages 3 and 4). SWE showed significantly elevated LF-marker levels at stage 2 compared with stages 0–1, and NASH was detected earlier than other LF markers. The areas under the receiver-operating characteristic curves (AUCs) for SWE, type IV collagen 7S, WFA(+)-M2BP, P-Ⅲ-P, hyaluronic acid, and FIB4 index for stage ≥3 were 0.86, 0.83, 0.79, 0.75, 0.75, and 0.77, respectively. With combined SWE and LF markers, the AUCs increased to 0.92, 0.88, 0.86, 0.88, and 0.88, respectively, showing increased diagnostic ability compared to that of single markers. The diagnostic ability of combined SWE and type IV collagen 7S was superior to that of other combinations. In addition, we detected that most cases were in stage ≥3 on combining SWE and LF markers. SWE for NASH can simply diagnose LF progression; the diagnostic capacity of SWE for LF improves in combination with LF-marker tests. It may be possible to detect the need for liver biopsy and treatment or follow-up, as well as reduce the number of liver biopsies by identifying NAFLD with low LF levels

Dynamic Assignment and Maintenance of Positional Identity in the Ventral Neural Tube by the Morphogen Sonic Hedgehog

During development of the vertebrate neural tube, cells acquire their positional identity from not only the spatial level of the Sonic Hedgehog signaling gradient, but also the temporal duration

RNF152 Negatively Regulates mTOR Signalling and Blocks Cell Proliferation in the Floor Plate

The neural tube is composed of a number of neural progenitors and postmitotic neurons distributed in a quantitatively and spatially precise manner. The floor plate, located in the ventral-most region of the neural tube, has a lot of unique characteristics, including a low cell proliferation rate. The mechanisms by which this region-specific proliferation rate is regulated remain elusive. Here we show that the activity of the mTOR signalling pathway, which regulates the proliferation of the neural progenitor cells, is significantly lower in the floor plate than in other domains of the embryonic neural tube. We identified the forkhead-type transcription factor FoxA2 as a negative regulator of mTOR signalling in the floor plate. We demonstrate that FoxA2 transcriptionally induces the expression of the E3 ubiquitin ligase RNF152, which together with its substrate RagA, regulates cell proliferation via the mTOR pathway. Silencing of RNF152 led to the aberrant upregulation of the mTOR signal and aberrant cell division in the floor plate. Taken together, the present findings suggest that floor plate cell number is controlled by the negative regulation of mTOR signalling through the activity of FoxA2 and its downstream effector RNF152

Hedgehog Signal and Genetic Disorders

The hedgehog (Hh) family comprises sonic hedgehog (Shh), Indian hedgehog (Ihh), and desert hedgehog (Dhh), which are versatile signaling molecules involved in a wide spectrum of biological events including cell differentiation, proliferation, and survival; establishment of the vertebrate body plan; and aging. These molecules play critical roles from embryogenesis to adult stages; therefore, alterations such as abnormal expression or mutations of the genes involved and their downstream factors cause a variety of genetic disorders at different stages. The Hh family involves many signaling mediators and functions through complex mechanisms, and achieving a comprehensive understanding of the entire signaling system is challenging. This review discusses the signaling mediators of the Hh pathway and their functions at the cellular and organismal levels. We first focus on the roles of Hh signaling mediators in signal transduction at the cellular level and the networks formed by these factors. Then, we analyze the spatiotemporal pattern of expression of Hh pathway molecules in tissues and organs, and describe the phenotypes of mutant mice. Finally, we discuss the genetic disorders caused by malfunction of Hh signaling-related molecules in humans