IL‐33‐ST2 pathway regulates AECII transdifferentiation by targeting alveolar macrophage in a bronchopulmonary dysplasia mouse model

Evidence points to the indispensable function of alveolar macrophages (AMs) in normal lung development and tissue homeostasis. However, the importance of AMs in bronchopulmonary dysplasia (BPD) has not been elucidated. Here, we identified a significant role of abnormal AM proliferation and polarization in alveolar dysplasia during BPD, which is closely related to the activation of the IL‐33‐ST2 pathway. Compared with the control BPD group, AMs depletion partially abolished the epithelialmesenchymal transition process of AECII and alleviated pulmonary differentiation arrest. In addition, IL‐33 or ST2 knockdown has protective effects against lung injury after hyperoxia, which is associated with reduced AM polarization and proliferation. The protective effect disappeared following reconstitution of AMs in injured IL‐33 knockdown mice, and the differentiation of lung epithelium was blocked again. In conclusion, the IL‐33‐ST2 pathway regulates AECII transdifferentiation by targeting AMs proliferation and polarization in BPD, which shows a novel strategy for manipulating the IL‐33–ST2‐AMs axis for the diagnosis and intervention of BPD.     

Active predation,phylogenetic diversity,and global prevalence of myxobacteria in wastewater treatment plants

The operation of modern wastewater treatment plants (WWTPs) is driven by activated sludge microbiota, a complex assemblage of trophically interacting microorganisms. Microbial predation is crucial to fundamental understanding of how biological interactions drive microbiome structuring and functioning of WWTPs. However, predatory bacteria have received little attention regarding their diversity, activity, and ecological function in activated sludge, limiting the exploitation of food web interactions for wastewater microbiome engineering. Here, by using rRNA-stable isotope probing of activated sludge microbiota with ¹³C-labeled prey bacteria, we uncovered diverse as-yet-uncultivated putative predatory bacteria that actively incorporated ¹³C-biomass. Myxobacteria, especially Haliangium and the mle1-27 clade, were found as the dominant active predators, refreshing conventional views based on a few predatory isolates of Bdellovibrionota from WWTPs. The identified predatory bacteria showed more selective predation on prey compared with the protists dominated by ciliates, providing in situ evidence for inter-domain predation behavior divergence in activated sludge. Putative predatory bacteria were tracked over a two-year microbiome monitoring effort at a local WWTP, revealing the predominance of Myxococcota (6.5 ± 1.3%) over Bdellovibrionota (1.0 ± 0.2%) lineages. Phylogenetic analysis unveiled highly diverse myxobacteria inhabiting activated sludge and suggested a habitat filtering effect in global WWTPs. Further mining of a global activated sludge microbiome dataset revealed the prevalence of Myxococcota (5.4 ± 0.1%) species and potential impacts of myxobacterial predation on process performance. Collectively, our findings provided unique insights into the predating activity, diversity, and prevalence of Myxococcota species in activated sludge, highlighting their links with wastewater treatment processes via trophic regulation of enteric and functional bacteria.Subject terms: Microbial ecology, Biodiversity, Environmental microbiology, Microbial ecology, Environmental sciences     

RBM46 is essential for gametogenesis and functions in post-transcriptional roles affecting meiotic cohesin subunits

RBM46 is a germ cell-specific RNA-binding protein required for gametogenesis, but the targets and molecular functions of RBM46 remain unknown. Here, we demonstrate that RBM46 binds at specific motifs in the 3ʹUTRs of mRNAs encoding multiple meiotic cohesin subunits and show that RBM46 is required for normal synaptonemal complex formation during meiosis initiation. Using a recently reported, high-resolution technique known as LACE-seq and working with low-input cells, we profiled the targets of RBM46 at single-nucleotide resolution in leptotene and zygotene stage gametes. We found that RBM46 preferentially binds target mRNAs containing GCCUAU/GUUCGA motifs in their 3ʹUTRs regions. In Rbm46 knockout mice, the RBM46-target cohesin subunits displayed unaltered mRNA levels but had reduced translation, resulting in the failed assembly of axial elements, synapsis disruption, and meiotic arrest. Our study thus provides mechanistic insights into the molecular functions of RBM46 in gametogenesis and illustrates the power of LACE-seq for investigations of RNA-binding protein functions when working with low-abundance input materials.     

Heterogeneous impact of cytomegalovirus reactivation on nonrelapse mortality in hematopoietic stem cell transplantation

This study aims to retrospectively analyze the efficacy of penciclovir in the prevention of viral infection after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Ninety-six patients with allo-HSCT were enrolled, who were treated at the Medical Center of Hematology of Xinqiao Hospital from June 2020 to September 2021. The experimental and control groups were treated with penciclovir and acyclovir, respectively, to prevent viral infection. By February 2022, the infection rates of cytomegalovirus, BK virus, JC virus, and Epstein-Barr virus (EBV) in the experimental group and the control group were 18.8% and 39.06% (P<0.05), 28.1% and 25% (P>0.05), 6.2% and 7.81% (P>0.05), 21.8% and 23.43% (P>0.05), respectively. The infection-related urinary system symptoms of the experimental group and the control group occurred in 4 and 9 patients, respectively, of which 3 and 9 patients died, respectively. Penciclovir can significantly reduce the cytomegalovirus infection rate after allo-HSCT and has better preventive effects than acyclovir without obvious side effects. The effectiveness and safety of penciclovir will be further verified in the future.     

Anti‐hsa‐miR‐59 alleviates premature senescence associated with Hutchinson‐Gilford progeria syndrome in mice

Hutchinson‐Gilford progeria syndrome (HGPS) is a lethal premature aging disorder without an effective therapeutic regimen. Because of their targetability and influence on gene expression, microRNAs (miRNAs) are attractive therapeutic tools to treat diseases. Here we identified that hsa‐miR‐59 (miR‐59) was markedly upregulated in HGPS patient cells and in multiple tissues of an HGPS mouse model (Lmna ^G609G/G609G ), which disturbed the interaction between RNAPII and TFIIH, resulting in abnormal expression of cell cycle genes by targeting high‐mobility group A family HMGA1 and HMGA2. Functional inhibition of miR‐59 alleviated the cellular senescence phenotype of HGPS cells. Treatment with AAV9‐mediated anti‐miR‐59 reduced fibrosis in the quadriceps muscle, heart, and aorta, suppressed epidermal thinning and dermal fat loss, and yielded a 25.5% increase in longevity of Lmna ^G609G/G609G mice. These results identify a new strategy for the treatment of HGPS and provide insight into the etiology of HGPS disease.     

THE ROLE OF LIGHT IN FRUCTIFICATION OF THE BASIDIOMYCETE CYATHUS STERCOREUS

Fructification in cultures of Cyathus stercoreus (Schw.) de Toni is a process in which photochemical reactions are involved. The amount of light energy required for fruiting to take place is a constant. This photoinductive constant is approximately 17200 foot-candle-hours considering optimum temperature (25 C) and light-saturation effect with reference to light intensity (240 ft-c). It is hypothesized that photoinduction becomes operative when a hypothetical “photoreceptive precursor” develops in the mycelium. The development of such a precursor is believed to occur when conditions unfavorable for good vegetative growth (e.g. shortage of food supply) develop in the culture. Internal metabolic pathways then shift to favor the production of the photoreceptive precursor. A linear function is derived which characterizes the biological photoinduction of fruit-body formation.     

天然沙冬青器官生态化学计量特征对异质生境的响应

以我国重点保护的珍稀濒危植物且是西北荒漠地区唯一常绿阔叶灌木沙冬青（Ammopiptanthus mongolicus）为研究对象,分析异质性荒漠生境（固定沙地、半固定沙地、石质沙地、洪积砾石坡地和盐碱滩地）对沙冬青叶、茎、根、花和种子生态化学计量学特征的影响,了解其生长的适应机制和生存策略。结果表明：沙冬青各器官碳（C）含量表现为叶 > 茎 > 根 > 种子 > 花,而氮（N）、磷（P）、钾（K）营养元素含量均表现为种子 > 花 > 叶 > 根 > 茎,N、P、K三大营养元素在繁殖器官中的富集,可以促进沙冬青由营养生长向生殖生长的转变,反映了资源分配模式和植物生长策略。沙冬青各器官的碳氮磷钾含量和各元素化学计量比在不同生境条件下变化较复杂,其中在沙质土壤（固定和半固定沙地）具有更高的C、N、P储存能力,而K在砾质土壤（石质沙地和洪积砾石坡地）含量较高,且砾质荒漠沙冬青的C：N、C：P 及 N：P 均显著高于沙质土壤,表明沙冬青在石质沙地和洪积砾石坡地有更高的养分利用效率。各器官元素含量相关分析表明器官间的养分协同性远高于器官内部。化学计量比C：N、C：P、C：K均表现为：茎 > 根 > 叶 > 花 > 种子,N：P为根 > 叶 > 茎 > 花 > 种子,N：K为茎 > 根 > 叶 > 种子 > 花,K：P 为叶 > 根 > 种子 > 茎 > 花,各器官中的C：N和N：P比在各生境间相对较稳定,而K：P比变化巨大,N：P与P含量呈显著的负相关（P <0.05）,与N含量的相关性不显著（P >0.05）,说明P作为敏感性元素决定了沙冬青体内N：P比值的变化,且不同生境叶片N：P比值均大于16,说明沙冬青生长主要受P限制。器官与生境对沙冬青化学计量特征都有影响,生境对C含量和N：K、K：P的影响较大,器官对N、P、K含量及C：N、C：P、C：K、N：P的影响较大。除P元素外,各元素含量及其化学计量比均受器官和生境交互作用影响。了解植物根-茎-叶-花-种子的整体资源权衡和协变策略,为沙冬青物种资源的保护和开发提供理论依据。     

塔里木荒漠河岸林物种多样性沿地下水埋深梯度的分布格局

探讨荒漠河岸林土壤水分、物种多样性的空间变异性及其相互关系,可为干旱区天然林保护、可持续经营和生态恢复提供科学依据。以塔里木荒漠河岸林为研究对象,基于野外样带调查和采样测定,系统分析了地下水埋深（GWD）梯度下林地土壤水分与物种多样性的空间变异及其权衡关系。结果表明：随GWD增加和土壤水分减少,荒漠河岸林群落物种数减少、结构简化、群落发生退化,退化顺序为浅根系的中生草本植物和灌木,最后留存的是抗旱性较强的乔灌木或灌木;同时土壤水分和物种丰富度、物种多样性指数均呈显著的线性递减趋势,而物种均匀度指数降幅较小。GWD与土壤水分、物种多样性之间均呈极显著的相关（P<0.01）,土壤水分与物种多样性的相对收益随GWD增加而逐渐降低,表明GWD是控制荒漠河岸林土壤水分和物种多样性空间变异的关键因素。荒漠河岸林土壤水分与物种多样性权衡关系的转折点为GWD 4.5m左右,转折点以下（GWD<4.5m）二者沿GWD以相同速率变化,呈协同关系;转折点以上（GWD>4.5m）土壤水分与物种多样性的权衡明显增大,土壤水分相对收益剧降,即维持当前相应的物种多样性以消耗土壤水分为代价,系统通过反馈调节使物种多样性降低。综上表明,维持塔里木荒漠河岸林物种多样性和生态系统功能的合理GWD在4.5m左右,这为塔里木河流域荒漠河岸林保育与生态输水工程实施提供科学依据。     

鸿雁迁徙对停歇地的选择特征

建立合理的湿地水鸟保护地是缓解水鸟栖息地丧失和种群下降的重要手段。以往的保护地设计中,由于越冬地和和繁殖地水鸟停留时间长、种群数量大,受到较多的关注。分析湿地水鸟对停歇地的选择偏好,掌握停歇地的自然条件和人类活动特征可为水鸟保护网络优化和保护地管理提供决策依据。而在水鸟迁徙过程中,停歇地作为保护网络的重要节点也发挥了重要作用。因此选择鸿雁为伞护种,获取了29只鸿雁项圈追踪数据,分析蒙古国Khukh湖-中国东北鸭绿江口秋季迁徙路线对停歇地生境选择偏好,识别了鸿雁在湿地周边不同距离梯度下的活动频率变化。根据鸿雁停歇数据共识别停歇地63处,以此为基础分析停歇的自然条件和人类活动因素特征。结果表明,鸿雁除选择湖泊和沼泽为停歇地外,周边250m内的裸地和草地也是重要栖息地;当鸿雁停歇地人类活动较少时,鸿雁倾向于选择土壤肥沃、食物丰富区,而人类活动强度加大时,栖息地植被条件提高能够为鸿雁提供遮避条件,也吸引了更多鸿雁停歇。研究建议,在水鸟迁徙重要廊道区应增加水鸟停歇地保护区,保护区的设计应根据关键保护对象活动频率加强对湿地周边的栖息地保护,减少水滨人类活动对鸿雁停歇的负面影响;在人类活动强度较大的地区设立水鸟保护地,还应加强对植被的保护,在水鸟利用频率较高的停歇地周边进行植被修复。