Wnt/Dkk Negative Feedback Regulates Sensory Organ Size in Zebrafish

SummaryCorrect organ size must involve a balance between promotion and inhibition of cell proliferation. A mathematical model has been proposed in which an organ is assumed to produce its own growth activator as well as a growth inhibitor [1], but there is as yet no molecular evidence to support this model [2]. The mechanosensory organs of the fish lateral line system (neuromasts) are composed of a core of sensory hair cells surrounded by nonsensory support cells. Sensory cells are constantly replaced and are regenerated from surrounding nonsensory cells [3], while each organ retains the same size throughout life. Moreover, neuromasts also bud off new neuromasts, which stop growing when they reach the same size [4, 5]. Here, we show that the size of neuromasts is controlled by a balance between growth-promoting Wnt signaling activity in proliferation-competent cells and Wnt-inhibiting Dkk activity produced by differentiated sensory cells. This negative feedback loop from Dkk (secreted by differentiated cells) on Wnt-dependent cell proliferation (in surrounding cells) also acts during regeneration to achieve size constancy. This study establishes Wnt/Dkk as a novel mechanism to determine the final size of an organ

肝細胞癌においてmiR125b-5pはAtaxin1による上皮間葉転換を介してソラフェニブ耐性を示す

The mechanism of resistance to sorafenib in hepatocellular carcinoma (HCC) remains unclear. We analyzed miRNA expression profiles in sorafenib-resistant HCC cell lines (PLC/PRF5-R1/R2) and parental cell lines (PLC/PRF5) to identify the miRNAs responsible for resistance. Drug sensitivity, migration/invasion capabilities, and epithelial-mesenchymal transition (EMT) properties were analyzed by biochemical methods. The clinical relevance of the target genes to survival in HCC patients were assessed using a public database. Four miRNAs were significantly upregulated in PLC/PRF5-R1/-R2 compared with PLC/PRF5. Among them, miR-125b-5p mimic-transfected PLC/PRF5 cells (PLC/PRF5-miR125b) and showed a significantly higher IC50 for sorafenib compared with controls, while the other miRNA mimics did not. PLC/PRF5-miR125b showed lower E-cadherin and higher Snail and vimentin expression—findings similar to those for PLC/PRF5-R2—which suggests the induction of EMT in those cells. PLC/PRF5-miR125b exhibited significantly higher migration and invasion capabilities and induced sorafenib resistance in an in vivo mouse model. Bioinformatic analysis revealed ataxin-1 as a target gene of miR-125b-5p. PLC/PRF5 cells transfected with ataxin-1 siRNA showed a significantly higher IC50, higher migration/invasion capability, higher cancer stem cell population, and an EMT phenotype. Median overall survival in the low-ataxin-1 patient group was significantly shorter than in the high-ataxin-1 group. In conclusion, miR-125b-5p suppressed ataxin-1 and consequently induced Snail-mediated EMT and stemness, leading to a poor prognosis in HCC patients.The mechanism of resistance to multikinase inhibitors in hepatocellular carcinoma (HCC) remains unclear. We analyzed miRNA expression profiles in sorafenib-resistant HCC cell lines (PLC/PRF5-R1/R2) and parental cell lines (PLC/PRF5) to identify the responsible miRNAs and target genes involved in the mechanism of resistance. Four miRNAs were significantly upregulated. Among them, we found that miR-125-5p induced sorafenib resistance in HCC cells and in a mouse model. We also revealed that miR-125-5p suppressed ataxin-1 as a target gene and consequently induced Snail-mediated epithelial-mesenchymal transition (EMT) and cancer stemness. Moreover, we demonstrated that ataxin-1 expression has an impact on the prognosis of patients with HCCs. In the future, by comparing the expression status of miR-125b-5p/ataxin-1 and the effect of sorafenib in the clinical setting, it is expected that miR-125b-5p will be established as an effective drug selection marker for treatment selection in patients with HCC

A donor-acceptor 10-cycloparaphenylene and its use as an emitter in an organic light-emitting diode

We thank JSPS Core-to-Core Program and International Joint Usage/Research Program of Institute for Chemical Research, Kyoto University (grant #2020-37 and 2021-37) for financial support. The St Andrews team would also like to thank EPSRC (EP/P010482/1) for financial support. D.C. thanks the China Scholarship Council (No. 201603780001). The Kyoto team would like to thank JSPS KAKENHI Grant Numbers JP20H05840 (Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton”).Here, we explored the possibility of using cycloparaphenylenes (CPP) within a donor–acceptor TADF emitter design. 4PXZPh-[10]CPP contains four electron-donating moieties connected to a [10]CPP. In the 15 wt % doped in CzSi film, 4PXZPh-[10]CPP showed sky-blue emission with λPL = 475 nm, ΦPL = 29%, and triexponential emission decays with τPL of 4.4, 46.3, and 907.8 ns. Solution-processed OLEDs using 4PXZPh-[10]CPP exhibited sky-blue emission with an λEL of 465 nm and an EQEmax of 1.0%.Publisher PDFPeer reviewe

Exact solution of kinetic analysis for thermally activated delayed fluorescence materials

Research at Kyushu, Kyoto and St Andrews Universities was supported by EPSRC and JSPS Core to Core grants (JSPS Core-to-core Program; EPSRC grant number EP/R035164/1). Authors are also grateful for financial support from the Program for Building Regional Innovation Ecosystems of the Ministry of Education, Culture, Sports, Science and Technology, Japan, JST ERATO Grant JPMJER1305, JSPS KAKENHI JP20H05840, and Kyulux Inc.The photophysical analysis of thermally activated delayed fluorescence (TADF) materials has become instrumental to providing insight into their stability and performance, which is not only relevant for organic light-emitting diodes (OLED), but also for other applications such as sensing, imaging and photocatalysis. Thus, a deeper understanding of the photophysics underpinning the TADF mechanism is required to push materials design further. Previously reported analyses in the literature of the kinetics of the various processes occurring in a TADF material rely on several a priori assumptions to estimate the rate constants for forward and reverse intersystem crossing (ISC and RISC, respectively). In this report, we demonstrate a method to determine these rate constants using a three-state model together with a steady-state approximation and, importantly, no additional assumptions. Further, we derive the exact rate equations, greatly facilitating a comparison of the TADF properties of structurally diverse emitters and providing a comprehensive understanding of the photophysics of these systems.PostprintPostprintPeer reviewe

Resveratrol inhibits development of colorectal adenoma via suppression of LEF1; comprehensive analysis with connectivity map

Although many chemopreventive studies on colorectal tumors have been reported, no effective and safe preventive agent is currently available. We searched for candidate preventive compounds against colorectal tumor comprehensively from United States Food and Drug Administration (FDA)-approved compounds by using connectivity map (CMAP) analysis coupled with in vitro screening with colorectal adenoma (CRA) patient-derived organoids (PDOs). We generated CRA-specific gene signatures based on the DNA microarray analysis of CRA and normal epithelial specimens, applied them to CMAP analysis with 1309 FDA-approved compounds, and identified 121 candidate compounds that should cancel the gene signatures. We narrowed them down to 15 compounds, and evaluated their inhibitory effects on the growth of CRA-PDOs in vitro. We finally identified resveratrol, one of the polyphenolic phytochemicals, as a compound showing the strongest inhibitory effect on the growth of CRA-PDOs compared with normal epithelial PDOs. When resveratrol was administered to ApcMin/+ mice at 15 or 30 mg/kg, the number of polyps (adenomas) was significantly reduced in both groups compared with control mice. Similarly, the number of polyps (adenomas) was significantly reduced in azoxymethane-injected rats treated with 10 or 100 mg/resveratrol compared with control rats. Microarray analysis of adenomas from resveratrol-treated rats revealed the highest change (downregulation) in expression of LEF1, a key molecule in the Wnt signaling pathway. Treatment with resveratrol significantly downregulated the Wnt-target gene (MYC) in CRA-PDOs. Our data demonstrated that resveratrol can be the most effective compound for chemoprevention of colorectal tumors, the efficacy of which is mediated through suppression of LEF1 expression in the Wnt signaling pathway

Latent trajectory modelling of pulmonary artery pressure in systemic sclerosis: a retrospective cohort study

OBJECTIVES: To visualise the trajectories of pulmonary arterial pressure (PAP) in systemic sclerosis (SSc) and identify the clinical phenotypes for each trajectory, by applying latent trajectory modelling for PAP repeatedly estimated by echocardiography. METHODS: This was a multicentre, retrospective cohort study conducted at four referral hospitals in Kyoto, Japan. Patients with SSc who were treated at study sites between 2008 and 2021 and who had at least three echocardiographic measurements of systolic PAP (sPAP) were included. A group-based trajectory model was applied to the change in sPAP over time, and patients were classified into distinct subgroups that followed similar trajectories. Pulmonary hypertension (PH)-free survival was compared for each trajectory. Multinomial logistic regression analysis was performed for baseline clinical characteristics associated with trajectory assignment. RESULTS: A total of 236 patients with 1097 sPAP measurements were included. We identified five trajectories: rapid progression (n=9, 3.8%), early elevation (n=30, 12.7%), middle elevation (n=54, 22.9%), late elevation (n=24, 10.2%) and low stable (n=119, 50.4%). The trajectories, in the listed order, showed progressively earlier elevation of sPAP and shorter PH-free survival. In the multinomial logistic regression analysis with the low stable as a reference, cardiac involvement was associated with rapid progression, diffuse cutaneous SSc was associated with early elevation and anti-centromere antibody was associated with middle elevation; older age of onset was associated with all three of these trajectories. CONCLUSION: The pattern of changes in PAP over time in SSc can be classified into five trajectories with distinctly different clinical characteristics and outcomes

zTrap: zebrafish gene trap and enhancer trap database

<p>Abstract</p> <p>Background</p> <p>We have developed genetic methods in zebrafish by using the <it>Tol2 </it>transposable element; namely, transgenesis, gene trapping, enhancer trapping and the Gal4FF-UAS system. Gene trap constructs contain a splice acceptor and the GFP or Gal4FF (a modified version of the yeast Gal4 transcription activator) gene, and enhancer trap constructs contain the zebrafish <it>hsp70l </it>promoter and the GFP or Gal4FF gene. By performing genetic screens using these constructs, we have generated transgenic zebrafish that express GFP and Gal4FF in specific cells, tissues and organs. Gal4FF expression is visualized by creating double transgenic fish carrying a Gal4FF transgene and the GFP reporter gene placed downstream of the Gal4-recognition sequence (UAS). Further, the Gal4FF-expressing cells can be manipulated by mating with UAS effector fish. For instance, when fish expressing Gal4FF in specific neurons are crossed with the UAS:TeTxLC fish carrying the tetanus neurotoxin gene downstream of UAS, the neuronal activities are inhibited in the double transgenic fish. Thus, these transgenic fish are useful to study developmental biology and neurobiology.</p> <p>Description</p> <p>To increase the usefulness of the transgenic fish resource, we developed a web-based database named <it>z</it>Trap <url>http://kawakami.lab.nig.ac.jp/ztrap/</url>. The <it>z</it>Trap database contains images of GFP and Gal4FF expression patterns, and genomic DNA sequences surrounding the integration sites of the gene trap and enhancer trap constructs. The integration sites are mapped onto the <it>Ensembl </it>zebrafish genome by in-house Blat analysis and can be viewed on the <it>z</it>Trap and <it>Ensembl </it>genome browsers. Furthermore, <it>z</it>Trap is equipped with the functionality to search these data for expression patterns and genomic loci of interest. <it>z</it>Trap contains the information about transgenic fish including UAS reporter and effector fish.</p> <p>Conclusion</p> <p><it>z</it>Trap is a useful resource to find gene trap and enhancer trap fish lines that express GFP and Gal4FF in desired patterns, and to find insertions of the gene trap and enhancer trap constructs that are located within or near genes of interest. These transgenic fish can be utilized to observe specific cell types during embryogenesis, to manipulate their functions, and to discover novel genes and <it>cis</it>-regulatory elements. Therefore, <it>z</it>Trap should facilitate studies on genomics, developmental biology and neurobiology utilizing the transgenic zebrafish resource.</p

癌関連脂肪細胞は膵癌のSAA1発現を誘導して膵癌の進展を促進する

Although pancreatic cancer often invades peripancreatic adipose tissue, little information is known about cancer-adipocyte interaction. We first investigated the ability of adipocytes to de-differentiate to cancer-associated adipocytes (CAAs) by co-culturing with pancreatic cancer cells. We then examined the effects of CAA-conditioned medium (CAA-CM) on the malignant characteristics of cancer cells, the mechanism underlying those effects, and their clinical relevance in pancreatic cancer. When 3T3-L1 adipocytes were co-cultured with pancreatic cancer cells (PANC-1) using the Transwell system, adipocytes lost their lipid droplets and changed morphologically to fibroblast-like cells (CAA). Adipocyte-specific marker mRNA levels significantly decreased but those of fibroblast-specific markers appeared, characteristic findings of CAA, as revealed by real-time PCR. When PANC-1 cells were cultured with CAA-CM, significantly higher migration/invasion capability, chemoresistance, and epithelial-mesenchymal transition (EMT) properties were observed compared with control cells. To investigate the mechanism underlying these effects, we performed microarray analysis of PANC-1 cells cultured with CAA-CM and found a 78.5- fold higher expression of SAA1 compared with control cells. When the SAA1 gene in PANC-1 cells was knocked down with SAA1 siRNA, migration/invasion capability, chemoresistance, and EMT properties were significantly attenuated compared with control cells. Immunohistochemical analysis on human pancreatic cancer tissues revealed positive SAA1 expression in 46/61 (75.4%). Overall survival in the SAA1-positive group was significantly shorter than in the SAA1-negative group (P = .013). In conclusion, we demonstrated that pancreatic cancer cells induced de-differentiation in adipocytes toward CAA, and that CAA promoted malignant characteristics of pancreatic cancer via SAA1 expression, suggesting that SAA1 is a novel therapeutic target in pancreatic cancer

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

Authors thank EU Horizon 2020 Grant Agreement No. 812872 (TADFlife) for funding this project. Further support was obtained by the Helmholtz Association Program at the Karlsruhe Institute of Technology (KIT). The German Research Foundation (formally Deutsche Forschungsgemeinschaft DFG) in the framework of SFB1176 Cooperative Research Centre "Molecular Structuring of Soft Matter" (CRC1176, A4, B3, C2, C6) and the cluster 3D Matter Made To Order all funded under Germany’s Excellence Strategy 2082/1--390761711 are greatly acknowledged for financial contributions. We acknowledge support from the Engineering and Physical Sciences Research Council of the UK (grant EP/P010482/1), from the International Collaborative Research Program of Institute for Chemical Research, Kyoto University (grant # 2020-37 and 2021-37), and from JSPS KAKENHI Grant Number JP20H05840 (Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton”). ZZ acknowledges the financial support from the China Scholarship Council (CSC, 201606890009) for his PhD studies. EZ-C is a Royal Society Leverhulme Trust Senior Research fellow (SRF\R1\201089).In this work we showcase the emitter DICzTRZ in which we employed a twin-emitter design of our previously reported material, ICzTRZ . This new system presented a redshifted emission at 488 nm compared to that of ICzTRZ at 475 nm and showed a comparable photoluminescence quantum yield of 57.1% in a 20 wt% CzSi film versus 63.3% for ICzTRZ . The emitter was then incorporated within a solution-processed organic light-emitting diode that showed a maximum external quantum efficiency of 8.4%, with Commission Internationale de l’Éclairage coordinate of (0.22, 0.47), at 1 mA cm−2.Publisher PDFPeer reviewe

The development and growth of tissues derived from cranial neural crest and primitive mesoderm is dependent on the ligation status of retinoic acid receptor γ:evidence that retinoic acid receptor γ functions to maintain stem/progenitor cells in the absence of retinoic acid

Retinoic acid (RA) signaling is important to normal development. However, the function of the different RA receptors (RARs)-RARα, RARβ, and RARγ-is as yet unclear. We have used wild-type and transgenic zebrafish to examine the role of RARγ. Treatment of zebrafish embryos with an RARγ-specific agonist reduced somite formation and axial length, which was associated with a loss of hoxb13a expression and less-clear alterations in hoxc11a or myoD expression. Treatment with the RARγ agonist also disrupted formation of tissues arising from cranial neural crest, including cranial bones and anterior neural ganglia. There was a loss of Sox 9-immunopositive neural crest stem/progenitor cells in the same anterior regions. Pectoral fin outgrowth was blocked by RARγ agonist treatment. However, there was no loss of Tbx-5-immunopositive lateral plate mesodermal stem/progenitor cells and the block was reversed by agonist washout or by cotreatment with an RARγ antagonist. Regeneration of the caudal fin was also blocked by RARγ agonist treatment, which was associated with a loss of canonical Wnt signaling. This regenerative response was restored by agonist washout or cotreatment with the RARγ antagonist. These findings suggest that RARγ plays an essential role in maintaining stem/progenitor cells during embryonic development and tissue regeneration when the receptor is in its nonligated state