NNC0268-0965

本文要点 研究背景与设计 针对肠细胞如何感知营养并决定非凋亡性细胞死亡（erebosis）的问题，利用果蝇模型、FRAP活体成像及惰性粘滞剂饲喂开展体内机制研究。 核心发现与意义 氨基酸总量通过降低胞质纳米级流体性驱动erebosis抑制，揭示了流体性作为独立于生化通路的物理性营养传感器，拓展了细胞命运调控范式。 营养与流体性关联 高氨基酸饮食或非代谢性α-氨基异丁酸显著升高胞质有效粘度，延长FRAP半恢复时间，并显著抑制erebosis。 机制特异性 遗传与药理干预证实，该效应不依赖GCN2-ATF4通路、自噬、尿素/尿酸/氨基酸代谢及Insulin/TOR信号，亦与渗透压无关。 物理干预验证 两种结构迥异的代谢惰性粘滞剂——阿拉伯糖与脱氧核糖——同样显著升高胞质粘度并显著抑制erebosis。 生理相关性 高蛋白的天然酵母饮食显著降低胞质流体性并抑制erebosis，而低蛋白的苹果饮食则驱动相反的生理效应。 核心关键词 细胞质流动性　　肠上皮细胞　　氨基酸代谢　　非凋亡性细胞死亡　　营养可用性　　细胞稳态　　果蝇　　粘度　　营养生理现象 科普解读 在营养充足的餐后与饥饿难耐的深夜，我们体内的细胞其实处于截然不同的工作状态。传统上，科学家认为细胞主要通过胰岛素、mTOR等精密的分子信号通路来感知营养变化。然而，发表在 Proceedings of the National Academy of Sciences 的一项最新研究，为这一认知增添了全新的物理维度：肠上皮细胞竟能通过感知自身细胞质的“流动性”来判断营养水平，并据此决定生死。 关西学院大学Sa Kan Yoo团队发现，食物中的氨基酸浓度——而非特定氨基酸的种类——会改变果蝇肠道细胞的 纳米级细胞质流度 ，进而调控一种名为“erebosis”的 非凋亡性细胞更新 过程。这一发现揭示了一种独立于经典分子信号、直接基于生物物理特性的营养适应机制。 当营养匮乏，肠道启动“细胞沉默” 肠道上皮是人体内外环境的交界，也是细胞更新最快的组织之一。研究团队此前在果蝇中鉴定出一种全新的细胞死亡方式——erebosis。与凋亡、坏死、自噬不同，发生erebosis的细胞会变得扁平膨大，最终悄然消失，以此维持肠道稳态。 在最新探索中，团队将目光投向了营养因素。他们利用在肠道细胞中特异性表达GFP荧光蛋白的转基因果蝇，系统筛查了不同营养成分对erebosis的影响。结果呈现清晰的剂量效应：当氨基酸浓度降低至标准培养基的十分之一时，erebosis频率 显著升高 ；而将氨基酸浓度提升至两倍时，erebosis则几乎 被完全抑制 。 引人注目的是，这种效应与氨基酸的“身份”无关。无论是必需氨基酸、非必需氨基酸，还是人体无法合成蛋白质的D-氨基酸，只要浓度足够，都能抑制erebosis。这一发现暗示，氨基酸并非通过经典的分子识别来发挥作用，而是依赖于某种 更基础的物理机制 。 代谢废物被排除，线索指向物理属性 为验证氨基酸代谢是否参与其中，团队逐一排除了尿素、尿酸、氨等主要代谢产物。即便通过基因敲除或药物抑制相应代谢通路，氨基酸对erebosis的调控依然不受影响。更关键的是，一种名为α-氨基异丁酸的 代谢惰性氨基酸类似物 ，在极低浓度（50 mM）下就强烈抑制了erebosis，而同等浓度的普通氨基酸则无效。 “这说明氨基酸甚至不需要被代谢，仅凭其分子存在本身就能执行调控功能。”研究团队据此推论，真正起作用的可能是细胞内分子拥挤度改变带来的 细胞质物理状态变化 ，而非任何生化信号。 FRAP实验揭示“纳米级流度”变化 为验证这一假说，研究者采用了荧光漂白恢复技术（FRAP）来测量GFP蛋白在肠道细胞质中的扩散速率——这直接反映了细胞质的 有效黏度 。结果显示，高氨基酸饮食显著减慢了GFP的恢复速度，意味着细胞质变得更“黏稠”、流动性更低。α-氨基异丁酸也产生了完全相同的效果。 研究团队进一步寻找了其他代谢惰性的“增黏剂”。通过系统的饥饿实验，他们筛选出两种果蝇无法代谢的单糖：阿拉伯糖与脱氧核糖。当将这些小分子黏度剂加入食物后，果然如预期般使细胞质黏度升高，同时erebosis频率显著下降。值得注意的是，这些黏度剂对经典的胰岛素、Tor信号通路几乎没有影响，有力地支持了细胞质流度作为独立调控因子的地位。 从实验室到自然食谱的验证 在生理条件的验证中，团队将果蝇分别喂食酵母（高蛋白）和苹果（低蛋白）。结果显示，酵母显著降低了肠道细胞质流度，并抑制了erebosis；而苹果则产生了相反的效果。 这一结果与自然生态高度吻合。在野外，果蝇以水果和酵母为食，水果蛋白质含量通常较低。研究团队推测，当营养充沛时，维持较低的细胞质流度有助于保留肠道细胞以吸收营养；而在营养匮乏时，细胞质流动性增加，促使肠道启动erebosis来“精简”细胞数量，减少不必要的能量消耗。这构成了一种 基于物理感知的适应性生存策略 。 研究团队在论文中强调，通过FRAP测量的GFP扩散反映的是 纳米级微观黏度 ，这与此前研究关注的核糖体等大分子拥挤造成的“介观尺度”拥挤完全不同。这一观察表明，细胞质流度可能是肠道细胞整合各种营养信号、直接感知整体“营养环境”的基础性物理机制。 未来，研究团队计划进一步探索细胞质流度如何被转化为执行erebosis的分子指令，以及这一机制是否在哺乳动物肠道中同样存在。 图片摘要 相关文章推荐 01 Cell Reports · IF: 7.7 Cell子刊：Mayo/CG11318调控果蝇中肠发育 02 Gut Microbes · IF: 15.3 免疫激活导致肠道细菌转录重编程 03 PNAS · IF: 9.5 鸡胚胎肠道如何从简单管状变出复杂形态？ 04 Mucosal Immunology · IF: 5.5 肠道IgA应答需依赖于两类CD4+T细胞亚群 05 Endocrine Reviews · IF: 23.9 类器官技术--揭示肠道激素可塑性的新途径 原文链接 https://rbase.chinagut.cn/base/article/74457fe64a094d9cb6abcd1261921ae8

CAYMAN ISLANDS, August 7, 2026 / EINPresswire.com / -- With the Atlantic hurricane season underway, clinicians at Health City Cayman Islands are urging residents and visitors across the Cayman Islands and the wider Caribbean who depend on regular medication, ongoing treatment or powered medical equipment to prepare well before a storm threatens. Major storms can disrupt electricity, transportation, pharmacies and healthcare services, placing patients with chronic conditions or ongoing medical needs at particular risk. Senior physicians at Health City warn that waiting until a hurricane watch or warning is issued may leave too little time to secure medication, supplies and alternative care arrangements. “For people who depend on prescription medication, ongoing treatment or powered medical equipment, preparing for hurricane season is especially important,” said Dr. Ramu Ramaswamy, an internal medicine specialist at Health City Cayman Islands. “A storm can interrupt access to pharmacies, medical services and electricity, making it difficult to obtain the care and supplies they need.” Medications and Chronic Care Patients should maintain at least a two-week supply of prescription medication — or more, where clinically appropriate — and request refills early. Physicians and pharmacists may authorize additional quantities specifically for hurricane preparedness. Keep written and digital records of each medication, including name, dosage and frequency, together with contact details for the prescribing physician and pharmacy. Medication should remain in its original labeled container and be stored in a cool, dry place inside a waterproof bag or container that can be collected quickly if evacuation becomes necessary. Temperature-sensitive medication, including insulin, requires additional planning. Patients should prepare insulated coolers and cold packs in advance and follow storage instructions carefully to protect the medication during a power outage. Patients who require dialysis, supplemental oxygen or other specialized treatment should discuss alternative arrangements with their physicians and confirm where care will be available if regular services are disrupted. Power-Dependent Medical Equipment Anyone using a continuous positive airway pressure (CPAP) machine, nebulizer or other powered medical device should know how long the equipment can operate on battery power. Backup batteries should be tested regularly and kept fully charged. A portable power station that meets the equipment’s power requirements may provide additional support during an outage. Generators can also supply backup power, but they must be operated outdoors and well away from windows, doors and vents. Never run a generator inside a home, garage or other enclosed space; carbon monoxide poisoning can be fatal. Clearly label all medical equipment and pack tubing, masks, chargers, adapters and spare parts together in an emergency bag that is easy to carry. Medical Records and Critical Supplies Prepare a compact medical go-bag or waterproof folder containing: A current list of medications and allergies A summary of medical conditions and recent test results Contact information for physicians and specialists Copies of identification and insurance documents Emergency contact details Any advance directives Store digital copies securely and download them so they remain accessible offline. A trusted relative, neighbor or caregiver should also hold a complete copy. Household emergency supplies should include adequate drinking water, first-aid and hygiene items, and nonperishable food suited to each person’s medical and dietary needs. Many standard emergency foods are high in sodium or sugar and may not be appropriate for patients managing certain conditions. Shelter and Evacuation Planning Identify the nearest designated emergency shelter and confirm what services and accommodations it provides. Hospitals, including Health City Cayman Islands, are not general emergency shelters and must remain available for patients who require acute care. Plan and practice evacuation routes, including how medical equipment will be transported. A trusted person outside the household should know the evacuation destination and understand the individual’s medical needs. Early preparation can help prevent a manageable condition from becoming an emergency during or after a storm. Reviewing prescriptions, testing backup power supplies and updating medical records now reduces the risk of dangerous interruptions in care. Health City Cayman Islands provides emergency and specialist care to the community throughout the hurricane season. Anyone seeking advice based on their individual medical needs should consult their physician or contact Health City at +1 345-640-4040. About Health City Cayman Islands Health City Cayman Islands (HCCI) is a medically advanced tertiary hospital with locations in East End and George Town in Grand Cayman. The brainchild of internationally-renowned heart surgeon and humanitarian Dr. Devi Shetty, it features a unique model of healthcare, built with a focus on the patient and rooted in innovative business models that allow the delivery of high quality, affordable care. A member of the Narayana Health network, HCCI is the first hospital in the Caribbean and one of only six organizations globally to receive the prestigious Joint Commission International (JCI) Enterprise Accreditation. For more information visit: www.healthcitycaymanislands.com . Dr. Karen Springer, Medical Advisor Marketplace Excellence +1 201-861-2056 email us here Legal Disclaimer: EIN Presswire provides this news content "as is" without warranty of any kind. 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