Microbiological research最新文献_第2页

Rhizosphere microbiota diversity and salt stress–alleviating functional genes in coastal wild salt-tolerant plants 沿海野生耐盐植物根际微生物群多样性与盐胁迫缓解功能基因

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-11 DOI: 10.1016/j.micres.2025.128397

Xixi Li , Xiaojing Gao , Shuyao Yu , Fengfeng Du , Jixiang Liu , Xuhui Kan , Xiaojing Liu , Dongrui Yao

Saline–alkali land significantly threatens global food security and ecological safety, and root-associated microorganisms help plants survive salt–alkali stress. However, the ecological functions and factors that influence the rhizosphere microbiomes of salt-tolerant plants remain poorly understood. In this study, we used high-throughput sequencing and metagenomics to reveal the microbial communities and functional traits of bulk and rhizosphere soil from salt-tolerant species (Suaeda glauca, Phragmites australis, and Spartina alterniflora) growing in saline soil. Bacterial and fungal taxa were significantly enriched in the rhizosphere soil compared to the non-rhizosphere soil. Metagenomic analyses revealed that metabolic pathways, including glycolysis and ABC transporters, were highly enriched in the rhizosphere. Functional profiling indicated that salt stress-related pathways were more abundant in the core genera Pseudomonas and Woeseia. The abundance of functional genes related to plant growth–promoting traits, including phosphate solubilization and salt adaptation pathways, was higher in the rhizosphere soil than in the non-rhizosphere soil, which was mainly driven by soil salinity, total nitrogen content, and total carbon content. Additionally, P. aeruginosa obtained from the rhizosphere of S. alterniflora exhibited high phosphorus solubilization efficiency (908.38 μg/mL), nitrogen fixation activity (2.84 μg/mL) and salt tolerance (≦ 5 % NaCl). These findings demonstrate that salt-tolerant plants shape microbial activities by controlling the rhizosphere microenvironment, mitigating salt stress, providing a scientific and practical foundation for the development of targeted microbial inoculants for saline–alkali land reclamation.

盐碱地严重威胁着全球粮食安全和生态安全，根系相关微生物帮助植物在盐碱胁迫下生存。然而，影响耐盐植物根际微生物群的生态功能和因素仍然知之甚少。本研究利用高通量测序和宏基因组学技术，揭示了盐碱地中耐盐植物（Suaeda glauca, Phragmites australis，和互花米草）块状土壤和根际土壤的微生物群落和功能特征。与非根际土壤相比，根际土壤中细菌和真菌分类群明显丰富。宏基因组分析显示，代谢途径，包括糖酵解和ABC转运蛋白，在根际高度富集。功能分析表明，盐胁迫相关途径在假单胞菌属和假单胞菌属中更为丰富。与植物促生长性状相关的功能基因丰度在根际土壤中高于非根际土壤，主要受土壤盐分、全氮含量和全碳含量的驱动。此外，从互花荆芥根际获得的铜绿假单胞菌具有较高的增磷效率（908.38 μg/mL）、固氮活性（2.84 μg/mL）和耐盐性（≦5 % NaCl）。研究结果表明，耐盐植物通过控制根际微环境，减轻盐胁迫影响微生物活性，为盐碱地垦殖微生物靶向接种剂的开发提供了科学和实践依据。

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引用次数: 0

Chlamydia trachomatis highjacks host MYO1C for actin cage recruitment at the bacterial inclusion 沙眼衣原体劫持宿主MYO1C，在细菌包涵体处进行肌动蛋白笼募集

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-11 DOI: 10.1016/j.micres.2025.128395

María Emilia Cuervo , Diego Del Balzo , María Natalia Zanetti , Mariela Beatriz Nolly , Hugo Lachuer , Rostislav Petkov , Nour Ismail , John Manzi , Rubén Walter Caron , Christophe Le Clainche , Maria Teresa Damiani , Julien Pernier , Kristine Schauer , Anahi Capmany

Chlamydia trachomatis (Ct), a Gram-negative obligate intracellular pathogen, manipulates host actin dynamics to facilitate its entry, development, and exit. It assembles a dynamic actin cage around its intracellular niche, known as the ‘inclusion’, which provides structural stability for bacterial growth, and is crucial for exit via the non-cell-lytic extrusion process. We found that Ct recruits Myosin 1 C (MYO1C), a ubiquitous actin dependent motor protein, to the inclusion throughout its life cycle. Consequently, loss of MYO1C activity reduced Ct infection and the production of bacterial progenies. Mechanistically, MYO1C functions as a dynamic tether that assembles an actin cage around the inclusion membrane, as depletion of MYO1C or its inhibition by pentachloropseudilin (PClP) leads to the loss of the actin network surrounding the inclusion. In vitro reconstitution assays revealed that the presence of purified MYO1C was necessary and sufficient to build an actin cage around giant membranous vesicles. In summary, our findings identified MYO1C as a novel host target of Ct and provided mechanistic evidence for its role as a dynamic tether to recruit the essential actin cage around the bacterial inclusion.

沙眼衣原体（Ct）是一种革兰氏阴性专性细胞内病原体，操纵宿主肌动蛋白动力学以促进其进入、发展和退出。它在其细胞内生态位周围组装了一个动态肌动蛋白笼，称为“内含物”，它为细菌生长提供了结构稳定性，并且对于通过非细胞裂解挤出过程退出至关重要。我们发现Ct在其整个生命周期中招募肌动蛋白1 C (MYO1C)，这是一种普遍存在的肌动蛋白依赖的运动蛋白。因此，MYO1C活性的丧失减少了Ct感染和细菌后代的产生。在机制上，MYO1C作为一个动态系绳，在包涵膜周围组装一个肌动蛋白笼，因为MYO1C的耗尽或其被五氯代戊二醇（PClP）抑制导致包涵周围的肌动蛋白网络的丢失。体外重建分析显示，纯化的MYO1C的存在是必要的，足以在巨大的膜囊泡周围建立肌动蛋白笼。总之，我们的研究结果确定了MYO1C是Ct的一个新的宿主靶点，并为其作为一种动态系绳在细菌包涵体周围招募必需肌动蛋白笼的作用提供了机制证据。

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引用次数: 0

Cellular responses of Aspergillus sydowii to growth at extreme chaotropic concentrations of MgCl2 西多曲霉对MgCl2极端混沌浓度下生长的细胞反应。

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-10 DOI: 10.1016/j.micres.2025.128390

Deborah González-Abradelo , Lyselle Ruíz de León , Reinier Gesto-Borroto , Tonatiuh Moreno-Perlín , Nilda del C. Sánchez-Castellanos , Yordanis Pérez-Llano , Juán Cabral-Miramontes , Elva Aréchiga-Carbajal , María del Rayo Sánchez-Carbente , Cene Gostinčar , Nina Gunde-Cimerman , Ramón Alberto Batista-García

Studies on microbial adaptations to salt stress, particularly in fungi, have focused mainly on high concentrations of NaCl. The effects of other inorganic salts on biological systems are much less well known. This study investigates the effects of MgCl₂ (0–2.0 M), a chaotropic salt, on the halophilic fungus Aspergillus sydowii (EXF-12860) and compares these results with those obtained with the kosmotropic NaCl. While A. sydowii thrived at MgCl₂ concentrations previously considered lethal (up to 2.0 M), differences in morphological, physiological, metabolic, and molecular responses were observed. At 0.5–1.0 M, growth rates were similar under both salts, but higher MgCl₂ concentrations (1.5–2.0 M) significantly inhibited growth, reduced hyphal elongation, and decreased cell density. During growth in the presence of NaCl, a wide range of carbon sources was utilized, but high MgCl₂ interfered with substrate metabolism and uncoupled growth from metabolic activity. Both salts induced the production of compatible solutes (glycerol, erythritol), with higher accumulation under MgCl₂. Oxidative stress responses were also stronger under MgCl₂, including increased catalase and glutathione peroxidase activity. Transcriptomic analyses revealed significant changes in gene expression under MgCl₂ stress, with upregulation of ion transport, cell wall remodelling, glycerol biosynthesis, and oxidative defense pathways. In contrast, NaCl triggered responses focused on osmotic balance and maintenance of cell integrity. These findings emphasize the need for a deeper investigation of microbial tolerance mechanisms in chaotropic environments.

微生物对盐胁迫的适应性研究，特别是真菌的适应性研究，主要集中在高浓度NaCl环境下。其他无机盐对生物系统的影响鲜为人知。本文研究了朝向盐MgCl2（0-2.0 M）对嗜盐真菌西多曲霉（EXF-12860）的影响，并将其与朝向盐NaCl的影响进行了比较。虽然以前认为致命的MgCl2浓度（高达2.0 M）会使A. sydowii繁殖，但观察到形态学、生理、代谢和分子反应的差异。在0.5-1.0 M浓度下，两种盐的生长速率相似，但较高的MgCl2浓度（1.5-2.0 M）显著抑制了生长，减少了菌丝伸长，降低了细胞密度。在NaCl存在下的生长过程中，利用了广泛的碳源，但高浓度的MgCl2干扰了底物代谢和代谢活性的不耦合生长。两种盐均诱导相容溶质（甘油、赤藓糖醇）的产生，且在MgCl2下积累量更高。MgCl2处理下的氧化应激反应也更强，包括过氧化氢酶和谷胱甘肽过氧化物酶活性增加。转录组学分析显示，MgCl2胁迫下基因表达发生显著变化，离子转运、细胞壁重塑、甘油生物合成和氧化防御途径上调。相比之下，NaCl引发的反应主要集中在渗透平衡和维持细胞完整性上。这些发现强调了对混沌环境中微生物耐受机制进行更深入研究的必要性。

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引用次数: 0

Disarming Salmonella virulence with 32H-hilE anti-virulence bacteriophage 用32h -hil抗毒噬菌体解除沙门氏菌的毒力

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-10 DOI: 10.1016/j.micres.2025.128396

Jinwoo Kim , Haejoon Park , Young Hyun Jung , Ho Jae Han , Doyeon Kim , Sangryeol Ryu , Minsik Kim

As the development of new antibiotics struggles with the continuous emergence of drug-resistant bacteria, targeting bacterial virulence factors instead of viability has been proposed as one of the alternative approaches to combat the pathogens. Here, we genetically engineered the temperate phage SPC32H to serve as a delivery vehicle for key negative regulators of Salmonella virulence to inhibit Salmonella infection. Negative regulator genes associated with Salmonella pathogenicity island 1 (SPI1), hilE, csrA, and lrp, were inserted into the phage SPC32H genome and expressed under a strong constitutive promoter. When Salmonella cells lysogenized by the engineered phages were exposed to the virulence-inducing condition, the expression of key positive regulators and major virulence factors associated with SPI1 was significantly reduced. Furthermore, in a murine early-intervention model, oral administration of the engineered phage 32H-hilE shortly after a lethal Salmonella challenge led to a significant increase in survival. No noticeable side effects were observed in mice treated with the engineered phage alone. These results suggest the relevance of the engineered phages that suppress the Salmonella virulence network as alternative anti-Salmonella agents without resistance concerns. This proof-of-concept study of anti-virulence phages could open a new avenue for controlling pathogenic bacteria using engineered temperate phages as vectors of anti-virulence factors.

随着新抗生素的开发与耐药细菌的不断出现作斗争，针对细菌毒力因子而不是生存力已被提出作为对抗病原体的替代方法之一。在这里，我们对温带噬菌体SPC32H进行基因工程改造，使其成为沙门氏菌毒力关键负调节因子的递送载体，以抑制沙门氏菌感染。将与沙门氏菌致病性岛1 （SPI1）相关的负调控基因hil、csrA和lrp插入噬菌体SPC32H基因组，并在强组成启动子下表达。当经工程噬菌体溶原的沙门氏菌细胞暴露于毒力诱导条件下时，SPI1相关的关键阳性调节因子和主要毒力因子的表达显著降低。此外，在小鼠早期干预模型中，在致命沙门氏菌攻击后不久口服工程噬菌体32H-hilE可显著提高存活率。在单独使用工程噬菌体治疗的小鼠中未观察到明显的副作用。这些结果表明，抑制沙门氏菌毒力网络的工程噬菌体作为无耐药性问题的替代抗沙门氏菌剂的相关性。这一抗毒力噬菌体的概念验证研究为利用工程温带噬菌体作为抗毒因子载体控制致病菌开辟了新的途径。

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引用次数: 0

Responses to nutrient starvation in the fission yeast Schizosaccharomyces pombe 分裂酵母对营养饥饿的反应。

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-07 DOI: 10.1016/j.micres.2025.128387

Hokuto Ohtsuka, Takafumi Shimasaki, Hirofumi Aiba

In nature, nutrient-poor environments are more common than exposure to nutrient-rich environments, and living organisms have developed countermeasures to survive nutrient starvation. Increasing research has revealed beneficial aspects of starvation for an individual’s life, including lifespan extension. The fission yeast Schizosaccharomyces pombe is a model unicellular eukaryotic organism and has greatly contributed to the understanding of various cellular processes, including the cell cycle, cell morphology, sexual development, cell lifespan, and nutritional responses. Traditionally, research on starvation in fission yeast has focused on glucose starvation and nitrogen starvation. Recently, studies on cellular responses to the starvation of various nutrients, such as phosphorus, sulfur, iron, zinc, copper, and amino acids have been reported, revealing similarities and differences among the various types of nutrient starvation. In fission yeast, Ecl proteins, which are conserved among fungi, can sense the starvation of multiple nutrients. These proteins also repress the target of rapamycin complex 1 (TORC1), which is conserved across eukaryotes. They channel a variety of starvation signals into common cellular responses, such as growth arrest, sexual differentiation, autophagy, and lifespan extension. This review summarizes and discusses the signaling mechanisms involved in the initial cellular responses of fission yeast to the starvation of various nutrients.

在自然界中，营养贫乏的环境比营养丰富的环境更常见，生物已经发展出应对营养饥饿的对策。越来越多的研究揭示了饥饿对人的生命有益的方面，包括延长寿命。裂糖酵母（Schizosaccharomyces pombe）是一种典型的单细胞真核生物，对了解细胞周期、细胞形态、性发育、细胞寿命和营养反应等细胞过程做出了重要贡献。传统上对裂变酵母饥饿的研究主要集中在葡萄糖饥饿和氮饥饿两方面。近年来，关于细胞对磷、硫、铁、锌、铜和氨基酸等多种营养物质饥饿反应的研究已被报道，揭示了各种营养物质饥饿的异同。在裂变酵母中，在真菌中保守的Ecl蛋白可以感知多种营养物质的饥饿。这些蛋白也抑制雷帕霉素复合体1 （TORC1）的靶标，这在真核生物中是保守的。它们将各种饥饿信号转化为常见的细胞反应，如生长停滞、性别分化、自噬和寿命延长。本文综述并讨论了裂变酵母对各种营养物质饥饿的初始细胞反应的信号机制。

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引用次数: 0

Combined transcriptome and microbiome characterization highlights digestive system development involved in the metabolism and immunity of the large yellow croaker (Larimichthys crocea) 转录组学和微生物组学的结合研究揭示了大黄鱼代谢和免疫过程中消化系统的发育

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-07 DOI: 10.1016/j.micres.2025.128394

Lizhen Li , Shaocong Huang , Zhiyi Bai , Hao Xu , Qun Ji , Wei Song

The development of the digestive system and its interaction with microbiota are critical for fish growth and health. Transcriptomic and 16S rRNA sequencing analyses were conducted to investigate the gene expression profiles of the digestive system and microbial community dynamics in Larimichthys crocea from the embryonic stage to day 28 to elucidate their potential roles in larval and juvenile development and their associations with immune and metabolic functions. The results revealed stage-specific changes in gene expression and microbial composition during development, and two critical transitional phases were identified: day 1 vs embryonic stage (C1 vs CE) and day 15 vs day 9 (C15 vs C9). Microbial succession demonstrated clear temporal characteristics: Pseudoalteromonas were dominant during the embryonic stage (CE), which was succeeded by Stenotrophomonas after hatching (C1, C3, C4, and C9), by Cohaesibacter on day 15 (C15), and by Psychrobacter as the core genus after formulated feed introduction on day 19. Functional enrichment analyses revealed predominant enrichment of differentially expressed genes in immune- and metabolic-related pathways, such as calcium signaling, steroid biosynthesis, and amino acid metabolism. Weighted gene co-expression network and correlation analyses revealed significant associations between specific genera (e.g., Rhodococcus and Psychrobacter) and immune- and metabolism-related genes. This study analyzed the developmental patterns of the digestive system of L. crocea and revealed significant correlations between shifts in the microbiota and host metabolism and immunity, highlighting the close association between the microbiota and metabolic and immune responses.

消化系统的发育及其与微生物群的相互作用对鱼类的生长和健康至关重要。通过转录组学和16S rRNA测序分析，研究了胭脂鱼（Larimichthys crocea）从胚胎期到第28天消化系统和微生物群落动态的基因表达谱，以阐明其在幼虫和幼鱼发育中的潜在作用及其与免疫和代谢功能的关联。结果揭示了发育过程中基因表达和微生物组成的阶段性变化，并确定了两个关键过渡阶段：第1天与胚胎期（C1 vs CE）和第15天与第9天（C15 vs C9）。微生物演替表现出明显的时间特征：假互变单胞菌在胚胎期（CE）占主导地位，孵化后为窄养单胞菌（C1、C3、C4和C9），第15天为Cohaesibacter (C15)，第19天引入配方饲料后为Psychrobacter成为核心属。功能富集分析显示，差异表达基因主要富集于免疫和代谢相关途径，如钙信号、类固醇生物合成和氨基酸代谢。加权基因共表达网络和相关分析显示，特定属（如红球菌和冷杆菌）与免疫和代谢相关基因之间存在显著关联。本研究分析了羊草消化系统的发育模式，揭示了微生物群的变化与宿主代谢和免疫之间的显著相关性，强调了微生物群与代谢和免疫应答之间的密切联系。

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引用次数: 0

The gut microbiota in post-stroke depression: A systematic review of microbial mechanisms and therapeutic targeting of neuroinflammation 脑卒中后抑郁的肠道微生物群：微生物机制和神经炎症治疗靶向的系统综述。

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-06 DOI: 10.1016/j.micres.2025.128391

Qianwen Zhang , Shiqing Zhang , Xingqin Cao , Yinghao Zhi , Ying Guo

Post-stroke depression (PSD), a frequent and debilitating complication after stroke, severely hinders rehabilitation. Emerging evidence underscores the role of neuroinflammation and the gut microbiota in PSD pathogenesis. This review systematically elaborates the mechanisms by which gut dysbiosis contributes to PSD-related neuroinflammation via immune cell regulation (e.g., Treg/Th17 balance), microbial metabolites (e.g., SCFAs, tryptophan derivatives), and neural pathways (vagus nerve, HPA axis). A key focus is the comparative analysis of the gut microbiota in PSD against major depressive disorder (MDD) and Alzheimer's disease (AD), revealing a unique, stroke-induced microbial signature characterized by a loss of protective symbionts and a bloom of pro-inflammatory taxa. We further discuss the translational potential of microbiota-targeted interventions (e.g., probiotics, prebiotics) for PSD. By integrating clinical microbial ecology with mechanistic insights, this review synthesizes evidence suggesting that the gut microbiome may represent a promising diagnostic and therapeutic target for PSD, offering a distinct perspective from previous literature.

卒中后抑郁（PSD）是卒中后常见的并发症，严重阻碍康复。新出现的证据强调了神经炎症和肠道微生物群在PSD发病机制中的作用。本综述系统阐述了肠道生态失调通过免疫细胞调节（如Treg/Th17平衡）、微生物代谢物（如scfa、色氨酸衍生物）和神经通路（迷走神经、HPA轴）促进psd相关神经炎症的机制。一个关键的焦点是PSD对重度抑郁症（MDD）和阿尔茨海默病（AD）的肠道微生物群的比较分析，揭示了一种独特的，中风诱导的微生物特征，其特征是保护性共生体的丧失和促炎类群的大量繁殖。我们进一步讨论了针对微生物群的干预措施（如益生菌，益生元）对PSD的转化潜力。通过将临床微生物生态学与机制见解相结合，本综述综合证据表明肠道微生物组可能代表PSD的有希望的诊断和治疗靶点，提供了与以往文献不同的视角。

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引用次数: 0

The hidden players: The mycobiome of pancreatic ductal adenocarcinoma tumors 隐藏的玩家：胰腺导管腺癌肿瘤的菌群

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-05 DOI: 10.1016/j.micres.2025.128392

Estrin Camille , Bertout Sébastien, Bellet Virginie

The microorganisms that inhabit the human body are known to play a role in human health and disease. Continuing to elucidate their specific role in disease progression is, however, necessary. The imbalance of these microorganisms–known as dysbiosis–has been linked to a myriad of intestinal diseases, and more recently to cancer. Despite making up less than 0.1 % of the human microbiome, dysbiosis of the fungal component of the microbiome—the mycobiome—has been found to contribute to the tumorigenesis and progression of certain types of tumors, pancreatic ductal adenocarcinoma (PDAC) included. The quantity and composition of the mycobiome was found to differ between healthy pancreatic tissue, the gut mycobiome of PDAC patients and PDAC tissue. Moreover, in a murine model of PDAC, it was shown that fungal ablation had a protective effect on tumor growth, and that specific fungal species, such as Malassezia globosa, contribute to tumor growth as well as to the inflammatory environment observed in PDAC tumors which promotes tumor progression. Research shows that fungal presence contributes to shaping the immune microenvironment through the activation of the complement system and/or by eliciting a type 2 immune response. Despite these preliminary findings, given the novelty of the field and of the bioinformatics pipelines used to analyze sequencing data, standardized approaches are still under development, thus leading to disagreement on the reliability of these results. The purpose of this review is to provide an up-to-date overview of the current research regarding the contribution of the fungal mycobiome in PDAC tumor progression and the overall tumor microenvironment (TME) of PDAC tumors.

众所周知，居住在人体中的微生物在人类健康和疾病中起着重要作用。然而，继续阐明它们在疾病进展中的具体作用是必要的。这些微生物的失衡——被称为生态失调——与无数的肠道疾病有关，最近还与癌症有关。尽管在人类微生物组中所占比例不到0.1% %，但微生物组的真菌成分——真菌组——的生态失调已被发现有助于某些类型肿瘤的发生和进展，包括胰腺导管腺癌（PDAC）。发现健康胰腺组织、PDAC患者肠道菌群和PDAC组织之间的菌群数量和组成存在差异。此外，在PDAC小鼠模型中，研究表明真菌消融对肿瘤生长具有保护作用，并且在PDAC肿瘤中观察到的特定真菌物种，如马拉色菌，促进肿瘤生长和炎症环境，从而促进肿瘤进展。研究表明，真菌的存在有助于通过激活补体系统和/或引发2型免疫反应来塑造免疫微环境。尽管有这些初步发现，鉴于该领域的新颖性和用于分析测序数据的生物信息学管道，标准化方法仍在开发中，因此导致对这些结果的可靠性存在分歧。这篇综述的目的是提供关于真菌菌群在PDAC肿瘤进展和PDAC肿瘤整体微环境（TME）中的贡献的最新研究综述。

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引用次数: 0

Bacteroides acidifaciens alleviates high-fat diet-induced obesity-related osteoporosis by regulating gut microbiota and bile acid metabolism via the gut-bone axis 酸化拟杆菌通过肠-骨轴调节肠道菌群和胆汁酸代谢，减轻高脂肪饮食引起的肥胖相关骨质疏松症

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-05 DOI: 10.1016/j.micres.2025.128393

Cihua Zheng , Jian Xie , Furui Tang , Zhuoya Wang , Li Liu , Yimin Pi , Yuchun Zhong , Zhidong He , Tian Liu , Jiacheng Zheng , Jun Luo

Obesity disrupts bone formation-resorption balance. Despite the established role of Bacteroides acidifaciens (B. acidifaciens) in modulating metabolic homeostasis, reducing inflammation, and improving lipid metabolism, its impact on obesity-associated osteoporosis is still not well understood. In this study, we delved into the potential protective influence of B. acidifaciens on high-fat diet (HFD) induced bone loss. The results showed that B. acidifaciens sharply improved weight gain, glucose and lipid metabolism in 16 weeks HFD mice. Both In vitro and in vivo experiments have conclusively demonstrated that the introduction of B. acidifaciens notably ameliorated the imbalance of HFD induced osteogenesis and osteoclastogenesis. B. acidifaciens also regulated HFD induced gut microbiota and bile acid metabolism, and strengthened intestinal mucosal barrier function. Additionally, B. acidifaciens significantly activated the AMPK-PPARα signaling pathway in bone tissue. Thus, our study indicated that B. acidifaciens regulated metabolism, restored gut microbiota balance, and activated AMPK-PPARα pathway to prevent HFD-induced bone loss, potentially aiding in preventing and treating obesity-related osteoporosis.

肥胖会破坏骨形成-吸收平衡。尽管酸化拟杆菌（B. acidifaciens）在调节代谢稳态、减少炎症和改善脂质代谢方面的作用已被确立，但其对肥胖相关骨质疏松症的影响仍未得到很好的了解。在这项研究中，我们深入研究了酸化芽杆菌对高脂肪饮食（HFD）引起的骨质流失的潜在保护作用。结果表明，增酸芽孢杆菌能显著改善16周HFD小鼠的增重、糖脂代谢。体外和体内实验均明确表明，引入酸化芽胞杆菌可显著改善HFD诱导的成骨和破骨细胞生成的不平衡。B.酸化菌还能调节HFD诱导的肠道菌群和胆汁酸代谢，增强肠黏膜屏障功能。此外，酸化芽胞杆菌显著激活骨组织AMPK-PPARα信号通路。因此，我们的研究表明，酸化芽胞杆菌可调节代谢，恢复肠道菌群平衡，激活AMPK-PPARα通路，预防hfd诱导的骨质流失，可能有助于预防和治疗肥胖相关性骨质疏松症。

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引用次数: 0

Co-regulation of HexC fine-tunes HexA-dependent transcription and acid stress response in Pectobacterium carotovorum 在胡萝卜乳杆菌中，HexC的协同调控微调了hexa依赖的转录和酸胁迫反应

IF 6.9 1区生物学 Q1 MICROBIOLOGY

Microbiological research

Pub Date : 2025-11-04 DOI: 10.1016/j.micres.2025.128389

Eunhye Goo , Serim Lee , Jae Hoon Lee

Environmental fluctuations and host-derived stresses demand precise transcriptional regulation in bacterial pathogens to ensure survival and pathogenic success. In Pectobacterium sp., causal agents of soft rot disease, the global regulator HexA is known to repress genes involved in plant cell wall-degrading enzyme (PCWDE) production, quorum sensing (QS), and virulence. However, its broader regulatory scope and physiological significance remain poorly understood. Here, we examined HexA function in P. carotovorum PCC27 through integrated ChIP-seq and RNA-seq analyses, revealing that HexA controls a diverse regulon, including transcriptional regulators, hypothetical proteins, and post-transcriptional regulators such as RsmA and RsmB. Among the newly identified targets, HexC, previously annotated as a hypothetical protein, was identified as a co-regulator that physically interacts with HexA and increases its DNA-binding affinity. Biochemical and genetic analyses demonstrated that HexC reinforces HexA-mediated transcriptional repression. The hexA/hexC double mutant produced higher levels of QS signals than the hexA single mutant but did not exhibit further increase in virulence. Phenotypic assays showed that the hexA/hexC mutant exhibited reduced fitness under acidic conditions yet outcompeted the wild-type at neutral pH in LB medium. However, in planta, the hexA, hexC, and hexA/hexC mutants consistently displayed reduced competitiveness compared to the wild-type in both single and mixed infections. These findings establish HexC as a co-repressor that fine-tunes HexA activity, providing mechanistic insights into how transcriptional regulation evolves to balance virulence and environmental fitness.

环境波动和宿主来源的压力需要细菌病原体精确的转录调控，以确保生存和致病成功。在软腐病的致病因子Pectobacterium sp.中，已知全局调节因子HexA抑制参与植物细胞壁降解酶（PCWDE）产生、群体感应（QS）和毒力的基因。然而，其更广泛的调控范围和生理意义仍然知之甚少。在这里，我们通过集成ChIP-seq和RNA-seq分析检测了HexA在p.c rotovorum PCC27中的功能，揭示了HexA控制着多种调控，包括转录调控因子、假设蛋白和转录后调控因子，如RsmA和RsmB。在新发现的靶点中，HexC，以前被注释为一种假设的蛋白质，被确定为与HexA物理相互作用并增加其dna结合亲和力的共同调节因子。生化和遗传分析表明，HexC增强了hexa介导的转录抑制。hexA/hexC双突变体比hexA单突变体产生更高水平的QS信号，但毒力没有进一步增加。表型分析表明，hexA/hexC突变体在酸性条件下适应性降低，但在中性pH的LB培养基中优于野生型。然而，在植物中，与野生型相比，在单一和混合感染中，hexA、hexC和hexA/hexC突变体始终表现出较低的竞争力。这些发现确定了HexC作为一种协同抑制因子，可以微调HexA的活性，为转录调控如何进化以平衡毒力和环境适应性提供了机制上的见解。

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