Long-range action of Wingless organizes the dorsal-ventral axis of the Drosophila wing

Development ◽  
1997 ◽  
Vol 124 (4) ◽  
pp. 871-880 ◽  
Author(s):  
C.J. Neumann ◽  
S.M. Cohen

Short-range interaction between dorsal and ventral (D and V) cells establishes an organizing center at the DV compartment boundary that controls growth and specifies cell fate along the dorsal-ventral axis of the Drosophila wing. The secreted signaling molecule Wingless (Wg) is expressed by cells at the DV compartment boundary and has been implicated in mediating its long-range patterning activities. Here we show that Wg acts directly, at long range, to define the expression domains of its target genes, Distal-less and vestigial. Expression of the Achaete-scute genes, Distal-less and vestigial at different distances from the DV boundary is controlled by Wg in a concentration-dependent manner. We propose that Wg acts as a morphogen in patterning the D/V axis of the wing.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15052-e15052
Author(s):  
Yongxia Zhu ◽  
Xinyi Chen ◽  
Qiangsheng Zhang ◽  
Lihong Shi ◽  
Luoting Yu ◽  
...  

e15052 Background: Enhancer of Zeste Homolog 2 (EZH2) is the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2) that regulate downstream target genes expression, and then promotes tumor cell proliferation, metastasis and drug resistance. EZH2 also performs some functions in a PRC2-independent manner. Most of reported EZH2 inhibitors are S-adenosyle-methionine (SAM)-competitive inhibitor, and are less selective for EZH2 close homolog EZH1, which resulted in safety concerns and insufficient efficacy. To obtain irreversible EZH2 inhibitor, a novel covalent inhibitor was developed and characterized. Methods: SKLB-0322 and its derivatives were designed, synthesized and confirmed as EZH2 covalent inhibitor by us. The anti-tumor activities of SKLB-0322 were investigated by MTT assay, flow cytometry, and western blot assay. The reversible analog of SKLB-0322 (SKLB-0322’) was used as negative control. Results: SKLB-0322 inhibited EZH2 methyltransferase activity with nanomolar potency, while the inhibitory activities of SKLB-0322’ was reduced. The mass spectrometry (MS) analyses revealed that SKLB-0322 could efficiently forms a single modified covalent adduct. SKLB-0322 displayed noteworthy potency against ovarian cancer cell lines at low micromolar level and reduced the expression level of H3K27me3 in a concentration-dependent manner, which was about 5-fold more active than the reversible negative control SKLB-0322’. Besides, SKLB-0322 caused G2/M phase cell cycle arrest in A2780 and PA-1 cells. Furthermore, SKLB-0322 induced A2780 and PA-1 cell apoptosis in a time- and concentration- dependent manner. Conclusions: Our data clarified that SKLB-0322 is an EZH2 covalent inhibitor for ovarian cancer therapy which is worthy of further evaluation.


2008 ◽  
Vol 28 (21) ◽  
pp. 6668-6680 ◽  
Author(s):  
Albertus T. J. Wierenga ◽  
Edo Vellenga ◽  
Jan Jacob Schuringa

ABSTRACT The level of transcription factor activity critically regulates cell fate decisions, such as hematopoietic stem cell (HSC) self-renewal and differentiation. We introduced STAT5A transcriptional activity into human HSCs/progenitor cells in a dose-dependent manner by overexpression of a tamoxifen-inducible STAT5A(1*6)-estrogen receptor fusion protein. Induction of STAT5A activity in CD34+ cells resulted in impaired myelopoiesis and induction of erythropoiesis, which was most pronounced at the highest STAT5A transactivation levels. In contrast, intermediate STAT5A activity levels resulted in the most pronounced proliferative advantage of CD34+ cells. This coincided with increased cobblestone area-forming cell and long-term-culture-initiating cell frequencies, which were predominantly elevated at intermediate STAT5A activity levels but not at high STAT5A levels. Self-renewal of progenitors was addressed by serial replating of CFU, and only progenitors containing intermediate STAT5A activity levels contained self-renewal capacity. By extensive gene expression profiling we could identify gene expression patterns of STAT5 target genes that predominantly associated with a self-renewal and long-term expansion phenotype versus those that identified a predominant differentiation phenotype.


2007 ◽  
Vol 21 (22) ◽  
pp. 3765-3781 ◽  
Author(s):  
MONIQUE COMBESCURE ◽  
AVINASH KHARE ◽  
ASHOK K. RAINA ◽  
JEAN-MARC RICHARD ◽  
CAROLE WEYDERT

A presentation and a generalization are given of the phenomenon of level rearrangement. This occurs when an attractive long-range potential is perturbed by a short-range attractive potential as its strength is increased. This phenomenon was first discovered in condensed matter physics and has also been studied in the physics of exotic atoms. A similar phenomenon occurs in a model that we propose, inspired by quantum dots, where a short-range interaction is added to a harmonic confinement.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11591
Author(s):  
Jianfeng Guo ◽  
Yapei Zhu ◽  
Lili Yu ◽  
Yuan Li ◽  
Jing Guo ◽  
...  

Background Ovarian cancer is the most common gynecological malignancy and is difficult to manage due to the emergence of resistance to various chemotherapeutic drugs. New efforts are urgently awaited. Aspirin, which is traditionally considered a nonsteroidal anti-inflammatory drug (NSAID), has been reported to exert potential chemopreventive effects. Therefore, we aimed to investigate the anticancer effect and explore the underlying molecular mechanisms of aspirin on epithelial ovarian cancer (EOC) cells. Methods We conducted wound healing, transwell migration, EdU cell proliferation, colony formation and apoptosis detection assays to observe the effects of aspirin on the migration, proliferation and apoptosis of EOC cells (A2870, Caov-3, and SK-OV-3). EOC cells were treated with a combination of aspirin and cisplatin (CDDP) to observe the effect of aspirin on enhancing CDDP sensitivity. Orthotopic xenograft models of ovarian cancer established with A2780-Luciferase-GFP cells were applied to compare tumor growth inhibition in the control, CDDP and CDDP plus aspirin groups through in vivo imaging, which can be used to continuously monitor tumor growth. The expression and acetylation levels of p53 in EOC cells treated with aspirin were determined using western blotting, and p53 acetylation levels were examined in tumors harvested from the transplanted mice. Quantitative real-time PCR was used to assess the mRNA expression of p53 target genes. Results Aspirin inhibited migration and proliferation and induced apoptosis in EOC cell lines in a concentration-dependent manner. In vitro, aspirin enhanced the sensitivity of EOC cells to CDDP by increasing its inhibitory effect on proliferation and its effect on inducing apoptosis. In vivo, the differences in the tumor growth inhibition rates among the different CDDP experimental groups were statistically significant (p < 0.05). Aspirin did not affect p53 protein expression but increased the p53 acetylation level in a concentration-dependent manner. In addition, the mRNA levels of CDKN1A, BAX, FOXF1, PUMA, and RRAD in EOC cells were significantly increased by the aspirin treatment. Conclusions Aspirin inhibits tumor progression and enhances the CDDP sensitivity of EOC cells. These antitumor effects of aspirin might be mediated by p53 acetylation and subsequent activation of p53 target genes.


2021 ◽  
Author(s):  
Yuchi Qiu ◽  
Lianna Fung ◽  
Thomas F. Schilling ◽  
Qing Nie

ABSTRACTThe vertebrate hindbrain is segmented into rhombomeres (r) initially defined by distinct domains of gene expression. Previous studies have shown that noise-induced gene regulation and cell sorting are critical for the sharpening of rhombomere boundaries, which start out rough in the forming neural plate (NP) and sharpen over time. However, the mechanisms controlling simultaneous formation of multiple rhombomeres and accuracy in their sizes are unclear. We have developed a stochastic multiscale cell-based model that explicitly incorporates dynamic morphogenetic changes (i.e. convergent-extension of the NP), multiple morphogens, and gene regulatory networks to investigate the formation of rhombomeres and their corresponding boundaries in the zebrafish hindbrain. During pattern initiation, the short-range signal, fibroblast growth factor (FGF), works together with the longer-range morphogen, retinoic acid (RA), to specify all of these boundaries and maintain accurately-sized segments with sharp boundaries. At later stages of patterning, we show a nonlinear change in the shape of rhombomeres with rapid left-right narrowing of the NP followed by slower dynamics. Rapid initial convergence improves boundary sharpness and segment size by regulating cell sorting and cell fate both independently and coordinately. Overall, multiple morphogens and tissue dynamics synergize to regulate the sizes and boundaries of multiple segments during development.Author SummaryIn segmental pattern formation, chemical gradients control gene expression in a concentration-dependent manner to specify distinct gene expression domains. Despite the stochasticity inherent to such biological processes, precise and accurate borders form between segmental gene expression domains. Previous work has revealed synergy between gene regulation and cell sorting in sharpening borders that are initially rough. However, it is still poorly understood how size and boundary sharpness ofmultiplesegments are regulated in a tissue that changes dramatically in its morphology as the embryo develops. Here we develop a stochastic multiscale cell-base model to investigate these questions. Two novel strategies synergize to promote accurate segment formation, a combination of long- and short-range morphogens plus rapid tissue convergence, with one responsible for pattern initiation and the other enabling pattern refinement.


2021 ◽  
Author(s):  
Gaurav Bhatt ◽  
Akshita Gupta ◽  
Latha Rangan ◽  
Anil Mukund Limaye

Karanjin, an abundantly occurring furanoflavonoid in edible and non-edible legumes, exerts diverse biological effects in vivo, and in vitro. Its potential as an anticancer agent is also gaining traction following recent demonstrations of its anti-proliferative, cell cycle inhibitory, and pro-apoptotic effects. However, the universality of its anticancer potential is yet to be scrutinized, particularly so because flavonoids can act as selective estrogen receptor modulators (SERMs). Even the genomic correlates of its biological activities are yet to be examined in hormone responsive cells. This paper presents the early and direct transcriptomic footprint of 10 μM karanjin in MCF-7 breast cancer cells, using next generation sequencing technology (RNA-seq). We show that karanjin-modulated gene-expression repertoire is enriched in several hallmark gene sets, which include early estrogen-response, and G2/M checkpoint genes. Genes modulated by karanjin overlapped with those modulated by 1 nM 17β-estradiol (E2), or 1 μM tamoxifen. Karanjin altered the expression of selected estrogen-regulated genes in a cell-type, and concentration dependent manner. It downmodulated the expression of ERα protein in MCF-7 cells. Furthermore, ERα knockdown negatively impacted karanjins ability to modulate the expression of selected E2 target genes. Our data suggest that karanjin exerts its effects on ERα-positive breast cancer cells, at least in part, via ERα. The apparent SERM-like effects of karanjin pose a caveat to the anticancer potential of karanjin. In-depth studies on cell-type and concentration-dependent effects of karanjin may bring out its true potential in endocrine therapies.


2021 ◽  
Author(s):  
Nusrat Sharmeen ◽  
Chris Law ◽  
Cunle Wu

Polarization or directional growth is a major morphological change that occurs in yeast cells during pheromone response to mate with the opposite partner. In the pheromone signaling pathway, the adaptor Ste50 is required to bind MAP3K Ste11 for proper polarization; cells lacking Ste50 are impaired in polarization. Direct involvement of Ste50 in the polarization process has not been explored systematically. Here, we used single-cell fluorescent time-lapse microscopy to characterize Ste50 involvement in the establishment of cell polarity. We found early localization of Ste50 patches on the cell cortex that mark the point of shmoo initiation, these polarity sites move, and patches remain associated with the growing shmoo tip in a pheromone concentration-dependent manner until shmoo maturation. By quantitative analysis we show that polarization corelates with the rising levels of Ste50 enabling rapid individual cell responses to pheromone that corresponds to a critical level of Ste50 at the initial G1 phase. Suggesting Ste50 to be a pheromone responsive gene. We exploited the quantitative differences in the pattern of Ste50 expression to corelate with the cell-cell phenotypic heterogeneity showing Ste50 involvement in the cellular differentiation choices. Taken together, these findings present spatiotemporal localization of Ste50 during yeast polarization, suggesting that Ste50 is a component of the polarisome, and plays a critical role in regulating the polarized growth of shmoo during pheromone response.


2021 ◽  
Vol 7 (2) ◽  
pp. 125
Author(s):  
Jonatan Niño-Sánchez ◽  
Li-Hung Chen ◽  
Jorge Teodoro De Souza ◽  
Sandra Mosquera ◽  
Ioannis Stergiopoulos

Exploiting RNA interference (RNAi) in disease control through non-transformative methods that overcome the hurdle of producing transgenic plants has attracted much attention over the last years. Here, we explored such a method and used non-pathogenic bacteria as a versatile system for delivering RNAi to fungi. Specifically, the RNaseIII-null mutant strain of Escherichia coli HT115(DE3) was transformed with two plasmid vectors that enabled the constitutive or IPTG-inducible production of double-stranded RNAs (dsRNAs) against genes involved in aflatoxins production in Aspergillus flavus (AflC) or virulence of Botrytis cinerea (BcSAS1). To facilitate the release of the dsRNAs, the bacterial cells were further genetically engineered to undergo a bacteriophage endolysin R-mediated autolysis, following a freeze-thaw cycle. Exposure under in vitro conditions of A. flavus or B. cinerea to living bacteria or their whole-cell autolysates induced silencing of AflC and BcSAS1 in a bacteria concentration-dependent manner, and instigated a reduction in aflatoxins production and mycelial growth, respectively. In planta applications of the living bacteria or their crude whole-cell autolysates produced similar results, thus creating a basis for translational research. These results demonstrate that bacteria can produce biologically active dsRNA against target genes in fungi and that bacteria-mediated RNAi can be used to control fungal pathogens.


2011 ◽  
Vol 19 (16) ◽  
pp. 15047 ◽  
Author(s):  
Daniel Weber ◽  
Pablo Albella ◽  
Pablo Alonso-González ◽  
Frank Neubrech ◽  
Han Gui ◽  
...  

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