GATA

本文为转化医学网原创，转载请注明出处 作者：Sophia 导读： 腹膜转移 （PM） 具有抑制性肿瘤免疫微环境 （TIME），限制了免疫治疗的效果。本研究旨在探讨腹膜内注射 IL-33 的免疫调节作用，IL-33 是一种据报道可增强抗肿瘤免疫和抑制转移的细胞因子。 近日，南京大学医学院附属医院南京鼓楼医院肿瘤科魏嘉团队在期刊《EMBO Molecular Medicine》发表题为“Macrophages reprogramming improves immunotherapy of IL-33 in peritoneal metastasis of gastric cancer”的研究论文， 研究发现腹膜内给药 IL-33 诱导乳糜泻炎症环境并抑制转移进展。IL-33 还可以激活下游信号通路，包括 NF-κB、p38 和 p44/42，并通过激活 p38-GATA 结合蛋白 3 信号通路诱导巨噬细胞的 M2 极化。IL-33联合抗CSF1R或p38抑制剂调节TAMs在腹部播散模型中具有协同抗肿瘤作用。 https://www-embopress-org.libproxy1.nus.edu.sg/doi/full/10.1038/s44321-023-00012-y 研究背景 01 胃癌 （GC） 是全球第六大常见癌症和癌症相关死亡的第三大原因，每年导致 100 万新诊断病例和约 800,000 人死亡。腹膜转移 （PM） 是 GC 患者最常见的复发和转移形式。大约 53-66% 的诊断为远处转移性 GC 的患者出现 PM，这与 6.0% 的惨淡 5 年生存率相关。虽然手术和化疗可以改善患者的临床预后，但GC合并PM的常用治疗措施仍不尽如人意。 基因组测序和分子分析的最新进展揭示了几个有前途的治疗靶点并阐明了新的生物学，特别是周围肿瘤免疫微环境 （TIME） 在 GC PM 中的作用。 PM 局限于腹腔;因此，局部给药治疗剂可以达到更高的药物浓度，但有少量全身不良反应。近年来，腹膜内化疗和局部细胞因子治疗已在腹膜肿瘤中探索。白细胞介素 （IL）-33 是 IL-1 超家族的一种细胞因子，通过其表面受体 ST2 触发 MyD88 依赖性急性炎症反应。MyD88 结合募集 IL-1 受体相关激酶和肿瘤坏死因子受体相关因子 6 激活核因子 κ B （NF-κB） 通路，促进炎性细胞因子表达。同时，IL-33信号转导已被证明通过p38依赖性机制增强转化生长因子β1（TGF-β1）介导的分化来增强叉头盒-P3和GATA结合蛋白3（GATA3）的表达。先前的研究表明，IL-33 主要诱导 2 型免疫反应，并与过敏和寄生虫病密切相关。最近有报道称，IL-33通过促进炎症细胞浸润和功能来增强抗肿瘤免疫力。最近，越来越多的已发表研究表明，IL-33可以募集和激活CD8 T细胞和自然杀伤（NK）细胞，以抑制肿瘤细胞的转移。 考虑到 PM 的空间局限性，我们研究了局部腹部给药 IL-33 以激活 TIME 并增强抗肿瘤免疫。 巨噬细胞是参与炎症反应和肿瘤进展的重要先天免疫细胞。越来越多的证据表明，IL-33 是一种复杂的双重作用细胞因子，这对于启动免疫反应和分化巨噬细胞至关重要。然而， IL-33驱动的巨噬细胞极化的分子机制仍然知之甚少。揭示IL-33诱导巨噬细胞极化的分子机制可能有助于基于IL-33的更好治疗效果。 研究进展 02 考虑到在恶性腹水来源的肿瘤细胞中观察到的IL-33 mRNA的低表达，我们进一步评估了IL-33在腹部播散性肿瘤中的抗肿瘤作用。为此，我们通过用小鼠前胃癌 （MFC） 细胞挑战 615 系小鼠，然后用 mIL-33 或磷酸盐缓冲盐水 （PBS） 处理它们来建立腹部播散性肿瘤模型（图 2A）。我们发现IL-33治疗组的腹部播散性肿瘤和肠系膜播散性肿瘤显着减少（图2B）。IL-33治疗小鼠的肿瘤重量（P = 0.0032）和肠系膜播散性肿瘤结节的数量（P = 0.0022）也减少（图2C）。此外，我们还观察了小鼠在治疗期间的存活率。结果显示，载体组小鼠的中位生存时间为23 d，而IL-33治疗组小鼠的中位生存时间可延长至30 d;两组间生存时间差异有统计学意义（P = 0.0373）。两组腹水于第16天采集。在载体组中，5只小鼠中有1只没有腹水，1只有少量无法清除的腹水。在IL-33治疗组中，五只小鼠中只有三只有腹水。与IL-33治疗组相比，载体组血性腹水程度更明显，表明IL-33降低了小鼠腹腔内的肿瘤负荷。实验组未见明显毒性或体重改变。上述结果表明，局部腹腔注射IL-33可有效触发GC腹部播散的抗肿瘤作用。 IL-33延缓GC腹部播散小鼠的肿瘤生长 研究结论 03 本研究，我们发现IL-33 mRNA高表达患者的生存期显著延长。在免疫功能正常的小鼠中，腹腔注射IL-33可诱导乳糜泻炎症环境，激活免疫效应细胞，逆转免疫抑制肿瘤微环境，有效延缓胃癌肿瘤进展和PM。从机制上讲， IL-33 可以通过激活 p38-GATA 结合蛋白 3 信号转导来诱导 M2 极化。IL-33联合抗CSF1R或p38抑制剂调节肿瘤相关巨噬细胞（TAMs）具有协同抗肿瘤作用。 通过IL-33给药诱导局部炎症环境为治疗腹膜转移提供了一种新的方法，当与TAM重编程相结合重塑TIME时，可以达到更好的治疗效果。 抑制性肿瘤免疫微环境限制了腹膜转移免疫治疗的有效性。由于其在抗肿瘤免疫中的已知作用，IL-33 的局部给药被测试为免疫功能正常小鼠的潜在疗法。 参考资料： https://www-embopress-org.libproxy1.nus.edu.sg/doi/full/10.1038/s44321-023-00012-y 注：本文旨在介绍医学研究进展，不能作为治疗方案参考。如需获得健康指导，请至正规医院就诊。 热门·直播/活动 🕓 上海｜3月01日-02日 ▶第三届长三角单细胞组学技术应用论坛暨空间组学前沿论坛将在上海召开，诚邀您的参与！ 点击对应文字 查看详情

How do nematodes distantly related to the best-studied one, Caenorhabditis elegans, make their gut, given that the genes responsible for specifying the gut in C. elegans are absent in other nematodes? Were it not for the COVID-19 pandemic, an important discovery about the development of nematodes -- elongated cylindrical worms -- might not have been made. With most classes and meetings at universities and schools having moved online in 2020-2021, a husband-and-wife research team at the University of California, Riverside, finally found some time to explore a question they had been mulling over for a long time: How do nematodes distantly related to the best-studied one, Caenorhabditis elegans, make their gut, given that the genes responsible for specifying the gut in C. elegans are absent in other nematodes? "The pandemic freed up some time for us to think about what research we would like to move forward with when the pandemic eased," said Morris Maduro, a professor of molecular, cell and systems biology and the corresponding author of the study published in Development, a journal. "Fortunately, an experiment we conducted generated a surprising result. It turns out a simpler gene network seems to be involved in specifying the gut in nematodes related to C. elegans. An ancestral species of C. elegans appears to have duplicated and expanded this simpler gene network to make one that is more complicated, and that complicated network is the one we have been studying all this time in C. elegans." Due in part to how fast it develops, C. elegans is one of the most widely used model organisms across biological disciplines, especially in studying how genes orchestrate development. About one millimeter in length, C. elegans lives like a scavenger in soil, where it feeds on microbes, such as bacteria, found on rotten food. The nematode is either male or hermaphrodite (with male and female reproductive organs) and is free living. It is neither a human nor plant parasite and does not infect or harm any organism known to scientists. Maduro, currently the chair of the Department of Molecular, Cell and Systems Biology, has studied C. elegans and other nematodes for more than two decades. He explained that nematodes have a simple anatomy. The digestive system is a single organ, the intestine, and in C. elegans it is made from the descendants of a single cell in the early embryo, called E. "We and others discovered about 20 years ago that the gene network that causes the E cell to become the gut progenitor involves several genes that are all related to a transcription factor family called GATA factors," Maduro said. Using C. elegans, Maduro's lab has long studied how transcription factors, which are proteins that activate the expression of genes, work in early animal embryos. "Transcription factors work in what we call gene networks, which are important in biology not only for development of plants and animals, but also for how organisms respond to changes in their environment, and even how cancer cells change their properties within tumors," Maduro said. He explained that proteins in living organisms can be thought of as being part of a genetic toolkit. "Imagine a toolbox with tools such as hammers and screwdrivers and drills," he said. "You can use the same tools to make a bookshelf or build a house. Although a bookshelf looks different from a house, they can be built with the same toolkit. Likewise, life forms find various ways to use proteins, the genetic tools that are the products of genes. Over time, however, different genes get activated to cause cells to perform certain functions in an animal or plant. The resulting gene networks involve different ways of using the same types of transcription factors." Maduro and his wife, Gina Broitman-Maduro, found that the genes they had studied for many years in C. elegans that specified the gut were missing in most other nematodes, leaving them wondering how the intestine gets made in these nematodes. "At the end of 2021, as the pandemic was easing up, we decided to look at a distant relative of C. elegans, called C. angaria, to see if we could figure out how it makes its gut," Maduro said. "It was a long-shot experiment as we were not expecting to figure it out. However, in a matter of a few months we found that the many GATA factors in C. elegans were just a single factor in C. angaria. This single factor, ELT-3, actually exists in C. elegans but it does not have the same function." In C. elegans the ELT-3 factor is known to be involved in stress responses and its function is replaced by the function of two other genes, END-1 and END-3. Just as in C. angaria when ELT-3 is deleted, the gut in C. elegans cannot form when both of END-1 and END-3 are missing. "Essentially, we are looking at a biological system that retains a simpler network from an earlier time in evolution -- probably 20-50 million years ago -- and we can compare it to a more complex version that evolved from it," Maduro said. "By peering inside cells, we can understand how the machinery of development changed over time. It's as if we had a time machine to look at the ancestors of C. elegans and understand how evolution resulted in one version of a gene network to change to another without significantly altering what the worm looks like. The changes are internal and happening 'under the hood,' and offer an extraordinary opportunity to understand how nature finds different ways to arrive at the same end point." To ensure they were on the right track, Maduro and Broitman-Maduro were able to force the C. angaria ELT-3 protein to be expressed at the right time and place in C. elegans. They showed it could specify the gut. "When people think about genes undergoing change over evolutionary time, they think about a plant or animal doing something different -- that is, the genes change so that the animal is bigger, or faster, or can do something that another species cannot, like resist some pathogen, or grow under harsher environmental conditions," said Broitman-Maduro, first author of the research paper and an associate specialist in the Maduro lab. "Here, the change in gene network doesn't appear to do anything fundamentally different: The anatomy and development of the distantly related species, C. angaria, are almost indistinguishable from C. elegans." A question Maduro and Broitman-Maduro are now investigating is why, compared to other nematodes, C. elegans would need a more complicated gene network to specify the gut. "One of our ideas is that the new network lets C. elegans develop more quickly, and we are trying to examine this idea in more detail," Maduro said. "Now that we know what specifies the gut in these distantly related nematodes, we plan to investigate if this mechanism is even more broadly conserved by looking in a more distantly related species, Pristionchus pacificus." Maduro and Broitman-Maduro were joined in the research by Simo Sun and Taisei Kikuchi of the University of Tokyo, Japan, who provided an updated genome sequence for C. angaria used in the study.

抽穗期、穗型和籽粒大小是影响水稻产量的重要农艺性状。迄今为止，尽管已在抽穗期和穗发育调控机制方面取得了许多重要研究进展，但目前仅鉴定出少数同时调控多个农艺性状的多功能基因。 抽穗期、穗型和籽粒大小是影响水稻产量的重要农艺性状。迄今为止，尽管已在抽穗期和穗发育调控机制方面取得了许多重要研究进展，但目前仅鉴定出少数同时调控多个农艺性状的多功能基因。 近日，Journal of Experimental Botany在线发表了上海交通大学生命科学技术学院林文慧研究组题为“OsGATA6 regulates rice heading date and grain number per panicle”的研究论文，该研究鉴定出一个新的GATA转录因子OsGATA6，同时影响水稻抽穗期、穗粒数和籽粒大小；过表达OsGATA6通过增加穗粒数提高了籽粒产量，这为提高水稻产量的育种计划提供了又一潜在靶标。上海交通大学生命科学技术学院助理研究员张燕洁为论文第一作者，林文慧研究员为该论文的通讯作者。 GATA家族蛋白是一类广泛存在于动物、真菌和植物中的转录调控因子，可识别靶基因保守的WGATAR基序，并参与器官分化和发育的调控。该研究组之前研究发现，GATA转录因子整合光和油菜素内酯信号通路，调节油菜素内酯介导的生长调控，并影响株型和粒型；在单细胞转录组图谱和染色质可及性图谱方面的合作研究也发现了一个新的GATA转录因子OsGATA6(LOC_Os01g54210)，参与水稻根尖基本和维管组织的发育。在此基础上，进一步对OsGATA6在水稻生殖生长方面的功能进行了探讨。 表达模式分析显示，OsGATA6在水稻中组成型表达，且在幼叶和穗中高量表达。原位杂交分析发现，OsGATA6特异性定位于穗原基的表层细胞。通过OsGATA6过表达、amiRNA干扰表达以及CRISPR-Cas9基因编辑进行功能鉴定，结果显示OsGATA6的过表达导致水稻抽穗延迟，粒数增加，籽粒减小；而其干扰沉默表达则与之相反，表明OsGATA6负调控抽穗期，但正调控穗发育，并影响籽粒大小（OsGATA6表达水平与粒重呈负相关）。 经基因表达水平检测发现，OsGATA6通过调节抽穗期相关基因的转录来调控水稻抽穗，尤其是抽穗前叶片中的核心成花素基因RICE FLOWERING LOCUS T 1（RFT1）和Heading date 3a（Hd3a），OsGATA6过表达系显示RFT1和Hd3a表达的降低。已知OsMFT1正调控抽穗期和穗粒数，其在amiRNA株系中显示下调。进一步分析发现，OsGATA6可直接与OsMFT1的启动子结合并诱导其表达，从而发挥抽穗期和穗发育调控功能。另外，OsGATA6在拟南芥中的过表达导致AtFT（FLOWERING LOCUS T）表达受抑制且开花延迟，AtFT与RFT1和Hd3a高度同源，这表明OsGATA6在水稻和拟南芥中的调控机制相似。