CFTR

本文为转化医学网原创，转载请注明出处 作者：Jerry 导读： SARS-CoV-2感染破坏上皮屏障并引发气道炎症。冠状病毒的核心毒力结构成分包膜(E)蛋白可能在这一过程中发挥作用。 2024年3月25日，广州医科大学钟南山团队在《Signal Transduction and Targeted Therapy》在线发表题为”SARS-CoV-2 envelope protein impairs airway epithelial barrier function and exacerbates airway inflammation via increased intracellular Cl− concentration“的研究论文， 该研究证明了E蛋白下调紧密连接蛋白的表达，导致气道上皮屏障的破坏。 https://www.nature.com/articles/s41392-024-01753-z 研究背景 01 SARS-CoV-2是导致COVID-19大流行的病原体，对全球公共卫生构成了重大挑战。SARS-CoV-2可能破坏肺泡上皮屏障，引发气道炎症加剧，导致呼吸困难，严重时进展为急性呼吸衰竭。然而，上皮屏障功能破坏和炎症增强的确切分子机制尚不完全清楚。了解SARS-CoV-2的致病机制有助于确定临床干预的新靶点。SARS-CoV-2是一种包膜病毒，具有正义单链RNA基因组。该病毒可破坏上皮细胞的完整性，加剧呼吸道上皮细胞的炎症，这是抵御病毒感染的第一道防线。 SARS-CoV-2编码四种结构蛋白——刺突蛋白(S)、包膜蛋白(E)、膜蛋白(M)和核衣壳蛋白(N)。S蛋白介导病毒与宿主受体血管紧张素转换酶2 (ACE2)的结合和病毒与细胞膜的融合。M蛋白在病毒组装中起着至关重要的作用，而N蛋白对病毒基因组的包装和存活至关重要。值得注意的是，E蛋白是一种核心结构毒力因子，在维持病毒生命周期(如病毒组装)中起着至关重要的作用。一些研究探索了SARS-CoV-2 S、M和N蛋白的致病作用。然而，SARS-CoV-2 E蛋白在上皮紧密连接和粘膜炎症中的作用和机制尚不清楚。 研究进展 02 鉴于E蛋白以PDE4-cAMP依赖的方式增加[Cl−]i，研究人员研究了靶向PDE4的药物对E蛋白介导的[Cl−]i升高和气道炎症的潜在保护作用。罗利普兰，一种选择性PDE4抑制剂，消除了E蛋白在人气道上皮细胞和mPAECs中引起的[Cl−]i升高。此外，罗利普兰治疗减轻了气道上皮细胞中IκB的磷酸化和促炎性细胞因子/趋化因子的上调。重要的是，在SARS-CoV-2 E蛋白刺激的小鼠气管内灌注模型中，罗利普兰抑制了mPAECs中升高的[Cl−]i，并在肺组织中发挥抗炎作用。这些结果表明，针对PDE4抑制的药理学干预可能有效地减轻气道上皮细胞内的细胞内Cl−积累，并减轻SARS-CoV-2感染引起的气道炎症。 为了验证上述发现，研究人员最终采用了hPAECs模型。有趣的是，E蛋白下调了hPAECs中ZO-1和闭合蛋白的表达，而claudin-4的表达则不受影响。此外，E蛋白引发了过度的炎症反应，其特征是促炎细胞因子的表达增加，以及hPAECs中JNK、IκB和SGK1的磷酸化水平升高。与在人气道上皮细胞系中的观察结果一致，E蛋白没有改变CFTR的表达，而是增加了PDE4亚型的表达，导致hPAECs中Cl−的异常积累。 这些结果进一步证实了SARS-CoV-2 E蛋白在破坏气道上皮完整性、促进炎症反应和扰乱气道上皮细胞内Cl−稳态中的作用。 SARS-CoV-2包膜蛋白通过增加细胞内Cl−浓度损害气道上皮屏障功能并加重气道炎症 研究结论 03 总之，SARS-CoV-2 E蛋白下调紧密连接蛋白，破坏气道上皮屏障的完整性。此外，E蛋白通过TLR2/4-JNK-AP-1信号通路上调PDE4表达，显著降低细胞内cAMP水平，导致CFTR介导的Cl−转运受损。本研究结果为E蛋白促进气道上皮细胞内Cl−水平的积累，从而加剧炎症反应提供了新的视角。旨在提高cAMP水平以打开CFTR的治疗干预，或使用CFTR拮抗剂和SGK1抑制剂以消除细胞内炎症级联反应的治疗干预，可能有望减轻SARS-CoV-2诱导的气道炎症。 参考资料： https://www.nature.com/articles/s41392-024-01753-z 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｜06月14日-16日 ▶ 第六届上海国际癌症大会将于6月14-16日在上海举办，学科交叉，共同推进肿瘤研究与诊治多模态！ 🕓 北京｜09月20日-21日 ▶ 第五届单细胞技术应用研讨会暨空间组学前沿研讨会欢迎您的参与！ 点击对应文字 查看详情

Conducted initial pivotal study interactions with the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA); Company has clear registration path for 4D-710 for treatment of cystic fibrosis (CF) lung disease in people with CF (pwCF) who are ineligible for or cannot tolerate approved CF modulator therapies AEROW clinical trial Phase 2 Expansion Cohort dose selection and initiation expected in Q2 2024, with pivotal trial initiation anticipated in H2 2025Initial GMP-ready suspension manufacturing process completed in-house at 500 liter scale; technology transfer initiation to commercial CDMO anticipated H1 2025Phase 1/2 AEROW clinical trial interim clinical data expected at the European Cystic Fibrosis Conference June 5-8, 2024, including safety, lung biomarker and clinical activity data on all nine patients dosed across four dose level cohorts EMERYVILLE, Calif., March 28, 2024 (GLOBE NEWSWIRE) -- 4D Molecular Therapeutics (Nasdaq: FDMT, 4DMT or the Company), a leading clinical-stage genetic medicines company focused on unlocking the full potential of genetic medicines to treat large market diseases, today announced an update on its regulatory interactions and development path for 4D-710, an aerosolized genetic medicine for the treatment of CF lung disease. Given high-level cystic fibrosis transmembrane conductance regulator (CFTR) transgene expression in all lung airway biopsies disclosed to date (significantly above normal lung CFTR levels), dose exploration continues with the evaluation of lower doses in the 4D-710 Phase 1/2 AEROW clinical trial in pwCF dosed at 5E14 vg (Cohort 3; n=1) and 2.5E14 vg (Cohort 4; n=1); nine pwCF total have been dosed to date (dose range 2.5E14 to 2E15 vg). Phase 2 Expansion Cohort dose selection is expected in Q2 2024 based on all clinical and lung biopsy data; the Company anticipates enrolling a total of six to nine pwCF in the Phase 2 Expansion Cohort. The Company submitted an AEROW trial amendment to the Cystic Fibrosis Therapeutics Development Network (TDN) as follows: 1) to enroll pwCF with lower baseline percent predicted forced expiratory volume in 1 second (ppFEV1) (50-90%) to assess ppFEV1 response to 4D-710, and 2) to add a second lung biopsy procedure at a longer-term timepoint (12 months or later) to study long term durability of 4D-710 CFTR transgene expression and optimal timing for redosing. The Company plans to share the following at the 47th European Cystic Fibrosis Conference (ECFS) held on June 5-8, 2024 in Glasgow, United Kingdom: 1) interim AEROW clinical and lung biomarker data on all nine pwCF dosed to date, 2) update on AEROW trial amendment status, and 3) development plan update for pwCF who are on modulators. In addition, the Company recently had discussions with the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA), regarding the registrational path for 4D-710 for treatment of CF lung disease in pwCF who are ineligible for or cannot tolerate approved CF modulator therapies. With regards to a full product approval in this patient population, the Company anticipates a Phase 3 randomized, controlled pivotal study enrolling approximately 60-80 pwCF with low baseline ppFEV1 (planned to be approximately 40-80%). Phase 3 clinical endpoints include changes after 4D-710 treatment in ppFEV1, quality-of-life (Cystic Fibrosis Questionnaire Revised Respiratory Domain, CFQ-R-RD) and frequency of pulmonary exacerbations. 4DMT is preparing for initiation of a Phase 3 clinical trial in H2 2025. Given the high unmet need in this CF population, an accelerated approval path may be feasible. The Company intends to have discussions with the FDA and EMA on an accelerated approval pathway, in parallel with Phase 3 planning, following additional AEROW clinical and lung biomarker data in pwCF with low baseline ppFEV1. 4D-710 is the first genetic medicine product candidate to demonstrate widespread and high-level CFTR expression (both RNA and protein) in the airways of pwCF; the Company will continue to evaluate the correlation between clinical endpoints and biomarker endpoints in participants with low baseline ppFEV1 in anticipation of further interactions on an accelerated approval pathway. In addition, the Company has completed in-house process development of a suspension GMP-ready manufacturing process for 4D-710 at 500 liter scale for the pivotal study and potential commercialization. This process, in combination with investigating lower doses, enables potentially lower cost of goods. The Company anticipates initiation of technology transfer to a commercial contract development and manufacturing organization (CDMO) in H1 2025. “We are encouraged by our productive interactions with the FDA and EMA on pivotal development plans for 4D-710, which we believe has the potential to be a transformative therapy for people with the highest unmet medical need for CF lung disease,” said David Kirn, M.D., Co-founder and Chief Executive Officer of 4DMT. “We are committed to advancing 4D-710 into pivotal trial development efficiently, while maintaining our current focus on initiation and completion of two Phase 3 wet AMD studies with 4D-150. Our goal is to initiate Phase 3 development in H2 2025 with 4D-710 suspension GMP process clinical trial material. We look forward to sharing interim clinical data from the AEROW Phase 1/2 clinical trial at the ECFS conference in June 2024.” About Cystic Fibrosis Lung Disease and 4D-710 Cystic fibrosis (CF) is an inherited, progressive disease caused by mutations in the CFTR gene. It affects the lungs, pancreas, and other organs. According to the Cystic Fibrosis Foundation, close to 40,000 people in the United States and an estimated 105,000 people people have been diagnosed with CF across 94 countries, with approximately 1,000 new cases of CF diagnosed in the United States each year. Lung disease is the leading cause of morbidity and mortality in people with CF. CF causes impaired lung function, inflammation and bronchiectasis and is commonly associated with persistent lung infections and repeated exacerbations due to the inability to clear thickened mucus from the lungs. People with CF require lifelong treatment with multiple daily medications. The complications of the disease result in progressive loss of lung function, increasing need for IV antibiotics and hospitalizations, ultimately leading to end-stage respiratory failure.4D-710 is comprised of our targeted and evolved next generation vector, A101, and a codon-optimized CFTR∆R transgene. 4D-710 has the potential to treat a broad range of people with CF, independent of the specific CFTR mutation, and is designed for aerosol delivery to achieve CFTR expression within lung airway epithelial cells. 4D-710 is being initially developed for the approximately 10-15% of people whose disease is not amenable to existing CFTR modulator medicines (based on variant-eligibility and/or drug intolerance) targeting the CFTR protein. In people with CFTR mutations whose disease is amenable to modulator medicines, and in some people with CF the improvement in lung function is incomplete and is variable. We therefore expect to potentially develop 4D-710 in this broader population, as a single agent and/or in combination with CFTR modulator small molecule medicines. 4D-710 has received the Rare Pediatric Disease Designation and Orphan Drug Designation from the FDA. About 4DMT 4DMT is a leading clinical-stage genetic medicines company focused on unlocking the full potential of genetic medicines to treat large market diseases in ophthalmology and pulmonology. 4DMT’s proprietary invention platform, Therapeutic Vector Evolution, combines the power of the Nobel Prize-winning technology, directed evolution, with approximately one billion synthetic AAV capsid-derived sequences to invent customized and evolved vectors for use in our wholly owned and partnered product candidates. Our product design, development, and manufacturing engine helps us efficiently create and advance our diverse product pipeline with the goal of revolutionizing medicine with potential curative therapies for millions of patients. Currently, 4DMT is advancing five clinical-stage and two preclinical product candidates, each tailored to address rare and large market diseases in ophthalmology, pulmonology, and cardiology. In addition, 4DMT is also advancing programs in CNS through a gene editing partnership. 4D Molecular Therapeutics™, 4DMT™, Therapeutic Vector Evolution™, and the 4DMT logo are trademarks of 4DMT. All of our product candidates are in clinical or preclinical development and have not yet been approved for marketing by the FDA or any other regulatory authority. No representation is made as to the safety or effectiveness of our product candidates for the therapeutic uses for which they are being studied. Learn more at www.4DMT.com and follow us on LinkedIn. Forward Looking Statements: This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, implied and express statements regarding the therapeutic potential, and clinical benefits of 4DMT’s product candidates, as well as the plans, announcements and related timing for the clinical development of 4D-710. The words "may," “might,” "will," "could," "would," "should," "expect," "plan," "anticipate," "intend," "believe," “expect,” "estimate," “seek,” "predict," “future,” "project," "potential," "continue," "target" and similar words or expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward looking statements in this press release are based on management's current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including risks and uncertainties that are described in greater detail in the section entitled "Risk Factors" in 4D Molecular Therapeutics’ most recent Quarterly Report on Form 10-Q as well as any subsequent filings with the Securities and Exchange Commission. In addition, any forward-looking statements represent 4D Molecular Therapeutics' views only as of today and should not be relied upon as representing its views as of any subsequent date. 4D Molecular Therapeutics explicitly disclaims any obligation to update any forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. Contacts: Media: Katherine SmithInizio Evoke CommsKatherine.Smith@inizioevoke.com Investors: Julian PeiHead of Investor Relations and Corporate FinanceInvestor.Relations@4DMT.com

引言SARS-CoV-2感染破坏上皮屏障并引发气道炎症。冠状病毒的核心毒力结构成分包膜(E)蛋白可能在这一过程中发挥作用。病原体可能通过破坏囊性纤维化跨膜传导调节剂(CFTR)来干扰Cl-的经上皮转运，CFTR调节核因子κB (NF-κB)信号。然而，SARS-CoV-2 E蛋白对气道上皮屏障功能、Cl−转运和强烈炎症反应的病理影响仍有待阐明。2024年3月25日，广州医科大学钟南山团队在Signal Transduction and Targeted Therapy（IF 39）在线发表题为”SARS-CoV-2 envelope protein impairs airway epithelial barrier function and exacerbates airway inflammation via increased intracellular Cl− concentration“的研究论文，该研究证明了E蛋白下调紧密连接蛋白的表达，导致气道上皮屏障的破坏。E蛋白通过上调气道上皮细胞磷酸二酯酶4D (PDE4D)表达，激活Toll样受体(TLR) 2/4和下游c-Jun N末端激酶(JNK)信号，导致细胞内Cl−浓度([Cl−]i)升高。这种升高的[Cl−]i通过促进血清/糖皮质激素调节激酶1 (SGK1)的磷酸化而导致气道炎症加剧。此外，阻断SGK1或PDE4可减轻E蛋白诱导的强烈炎症反应。总的来说，这些发现为SARS-CoV-2 E蛋白在SARS-CoV-2感染期间气道上皮损伤和持续气道炎症中的致病作用提供了新的见解。SARS-CoV-2是导致COVID-19大流行的病原体，对全球公共卫生构成了重大挑战。SARS-CoV-2可能破坏肺泡上皮屏障，引发气道炎症加剧，导致呼吸困难，严重时进展为急性呼吸衰竭。然而，上皮屏障功能破坏和炎症增强的确切分子机制尚不完全清楚。了解SARS-CoV-2的致病机制有助于确定临床干预的新靶点。SARS-CoV-2是一种包膜病毒，具有正义单链RNA基因组。该病毒可破坏上皮细胞的完整性，加剧呼吸道上皮细胞的炎症，这是抵御病毒感染的第一道防线。SARS-CoV-2编码四种结构蛋白——刺突蛋白(S)、包膜蛋白(E)、膜蛋白(M)和核衣壳蛋白(N)。S蛋白介导病毒与宿主受体血管紧张素转换酶2 (ACE2)的结合和病毒与细胞膜的融合。M蛋白在病毒组装中起着至关重要的作用，而N蛋白对病毒基因组的包装和存活至关重要。值得注意的是，E蛋白是一种核心结构毒力因子，在维持病毒生命周期(如病毒组装)中起着至关重要的作用。一些研究探索了SARS-CoV-2 S、M和N蛋白的致病作用。然而，SARS-CoV-2 E蛋白在上皮紧密连接和粘膜炎症中的作用和机制尚不清楚。气道屏障由紧密连接、纤毛粘液清除和免疫细胞组成。紧密连接是由claudin家族跨膜蛋白组成的超分子实体，通过含有支架蛋白的细胞质PDZ结构域与肌动蛋白细胞骨架相连。紧密连接通过维持粘膜单层的完整性和细胞极性，建立物理屏障，调节分子的细胞旁通透性，调节先天免疫。然而，在呼吸道病毒感染期间，由于紧密连接蛋白的表达失调，屏障功能可能受损，导致入侵的病原体进入上皮下间隙。先前的研究表明，SARS-CoV-2的高病毒载量可破坏气道上皮紧密连接，部分涉及与Lin-7-1相关蛋白(PALS1)的相互作用。此外，SARS-CoV-2 E蛋白还可能与紧密连接蛋白zona occluden-1 (ZO-1)相互作用，导致上皮紧密连接损伤。这些观察结果表明，SARS-CoV-2 E蛋白在触发上皮屏障功能障碍中起关键作用。纤毛粘膜清除在维持气道微环境的稳态，确保有效清除入侵病原体方面起着至关重要的作用。纤毛黏液清除的有效性部分取决于水和离子运输的动力学。氯离子(Cl−)是人体内的主要阴离子，细胞内的Cl−浓度([Cl−]i)受到多种Cl−通道和转运体的严格调控。最近的证据表明，细胞内Cl-可能调节信号，细胞内Cl-稳态的破坏可能与多种细胞功能的改变有关，如炎症和免疫紊乱。模式图（Credit: Signal Transduction and Targeted Therapy）因此，细胞内Cl−的积累可能在病原体(如病毒)感染后持续气道炎症的放大中发挥重要作用。囊性纤维化跨膜传导调节剂(CFTR)是一种3'，5' -环单磷酸盐(cAMP)激活的Cl-通道，表达于全身上皮细胞的顶端膜。在上皮细胞中，各种病原体的感染可导致CFTR表达降低或功能障碍，导致阴离子分泌受损，细胞内Cl−失衡。有趣的是，CFTR和TMEM16介导的Cl-外排参与了SARS-CoV-2的进入和复制，这表明细胞内Cl-信号在SARS-CoV-2感染过程中发挥了作用。Toll样受体(TLRs)是一种模式识别受体(PRRs)，通过识别病原体相关分子模式(PAMPs)在感染过程中启动炎症反应和先天防御反应。研究证实TLR2能够识别SARS-CoV-2的S蛋白和E蛋白，在COVID-19的发生发展中发挥了至关重要的作用。丝裂原活化蛋白激酶(MAPK)级联是高度保守的信号分子，负责将细胞外刺激转导为细胞信号。哺乳动物细胞中有三种主要的MAPK通路，包括细胞外信号调节激酶(ERK，也称为p42/p44 MAPK)、c-Jun N-末端激酶(JNK，也称为应激激活蛋白激酶，SAPK)和p38激酶。MAPK通路已被证明可被多种病毒激活，因此是缓解病毒诱导的炎症细胞因子风暴的关键靶点。因此，研究TLR信号通路和MAPK通路在SARS-CoV-2感染过程中的参与可能有助于阐明COVID-19的免疫发病机制，并探索有价值的抗病毒治疗靶点。因此，该研究旨在探讨SARS-CoV-2 E蛋白对气道上皮完整性和炎症反应的病理影响及其潜在机制。原文链接https://www.nature.com/articles/s41392-024-01753-z责编|探索君排版|探索君文章来源|“iNature”End往期精选围观一文读透细胞死亡(Cell Death) | 24年Cell重磅综述（长文收藏版）热文Nature | 破除传统：为何我们需要重新思考肿瘤的命名方式热文Nature | 2024年值得关注的七项技术热文Nature | 自身免疫性疾病能被治愈吗？科学家们终于看到了希望热文CRISPR技术进化史 | 24年Cell综述