bims-polyam 2024-08-11 papers

Issue of 2024–08–11
seven papers selected by
Sebastian J. Hofer, University of Graz

Nat Cell Biol. 2024 Aug 08.

Spermidine is essential for fasting-mediated autophagy and longevity.

Sebastian J Hofer, Ioanna Daskalaki, Martina Bergmann, Jasna Friščić, Andreas Zimmermann, Melanie I Mueller, Mahmoud Abdellatif, Raffaele Nicastro, Sarah Masser, Sylvère Durand, Alexander Nartey, Mara Waltenstorfer, Sarah Enzenhofer, Isabella Faimann, Verena Gschiel, Thomas Bajaj, Christine Niemeyer, Ilias Gkikas, Lukas Pein, Giulia Cerrato, Hui Pan, YongTian Liang, Jelena Tadic, Andrea Jerkovic, Fanny Aprahamian, Christine E Robbins, Nitharsshini Nirmalathasan, Hansjörg Habisch, Elisabeth Annerer, Frederik Dethloff, Michael Stumpe, Franziska Grundler, Françoise Wilhelmi de Toledo, Daniel E Heinz, Daniela A Koppold, Anika Rajput Khokhar, Andreas Michalsen, Norbert J Tripolt, Harald Sourij, Thomas R Pieber, Rafael de Cabo, Mark A McCormick, Christoph Magnes, Oliver Kepp, Joern Dengjel, Stephan J Sigrist, Nils C Gassen, Simon Sedej, Tobias Madl, Claudio De Virgilio, Ulrich Stelzl, Markus H Hoffmann, Tobias Eisenberg, Nektarios Tavernarakis, Guido Kroemer, Frank Madeo.

Caloric restriction and intermittent fasting prolong the lifespan and healthspan of model organisms and improve human health. The natural polyamine spermidine has been similarly linked to autophagy enhancement, geroprotection and reduced incidence of cardiovascular and neurodegenerative diseases across species borders. Here, we asked whether the cellular and physiological consequences of caloric restriction and fasting depend on polyamine metabolism. We report that spermidine levels increased upon distinct regimens of fasting or caloric restriction in yeast, flies, mice and human volunteers. Genetic or pharmacological blockade of endogenous spermidine synthesis reduced fasting-induced autophagy in yeast, nematodes and human cells. Furthermore, perturbing the polyamine pathway in vivo abrogated the lifespan- and healthspan-extending effects, as well as the cardioprotective and anti-arthritic consequences of fasting. Mechanistically, spermidine mediated these effects via autophagy induction and hypusination of the translation regulator eIF5A. In summary, the polyamine-hypusination axis emerges as a phylogenetically conserved metabolic control hub for fasting-mediated autophagy enhancement and longevity.

DOI: https://doi.org/10.1038/s41556-024-01468-x

PLoS Biol. 2024 Aug;22(8): e3002731

Salmonella Typhimurium exploits host polyamines for assembly of the type 3 secretion machinery.

Tsuyoshi Miki, Takeshi Uemura, Miki Kinoshita, Yuta Ami, Masahiro Ito, Nobuhiko Okada, Takemitsu Furuchi, Shin Kurihara, Takeshi Haneda, Tohru Minamino, Yun-Gi Kim.

Bacterial pathogens utilize the factors of their hosts to infect them, but which factors they exploit remain poorly defined. Here, we show that a pathogenic Salmonella enterica serovar Typhimurium (STm) exploits host polyamines for the functional expression of virulence factors. An STm mutant strain lacking principal genes required for polyamine synthesis and transport exhibited impaired infectivity in mice. A polyamine uptake-impaired strain of STm was unable to inject effectors of the type 3 secretion system into host cells due to a failure of needle assembly. STm infection stimulated host polyamine production by increasing arginase expression. The decline in polyamine levels caused by difluoromethylornithine, which inhibits host polyamine production, attenuated STm colonization, whereas polyamine supplementation augmented STm pathogenesis. Our work reveals that host polyamines are a key factor promoting STm infection, and therefore a promising therapeutic target for bacterial infection.

DOI: https://doi.org/10.1371/journal.pbio.3002731

Sci Rep. 2024 Aug 05. 14(1): 18094

Identifying polyamine related biomarkers in diagnosis and treatment of ulcerative colitis by integrating bulk and single-cell sequencing data.

Wanhui Wei, Yuanyuan Lu, Mengjiao Zhang, JinKun Guo, Heng Zhang.

Ulcerative colitis (UC) is a chronic inflammatory disorder of the colon, and its pathogenesis remains unclear. Polyamine metabolic enzymes play a crucial role in UC. In this study, we aimed to identify pivotal polyamine-related genes (PRGs) and explore the underlying mechanism between PRGs and the disease status and therapeutic response of UC. We analyzed mRNA-sequencing data and clinical information of UC patients from the GEO database and identified NNMT, PTGS2, TRIM22, TGM2, and PPARG as key PRGs associated with active UC using differential expression analysis and weighted gene co-expression network analysis (WCGNA). Receiver operator characteristic curve (ROC) analysis confirmed the accuracy of these key genes in UC and colitis-associated colon cancer (CAC) diagnosis, and we validated their relationship with therapeutic response in external verification sets. Additionally, single-cell analysis revealed that the key PRGs were specific to certain immune cell types, emphasizing the vital role of intestinal tissue stem cells in active UC. The results were validated in vitro and in vivo experiments, including the colitis mice model and CAC mice model. In conclusion, these key PRGs effectively predict the progression of UC patients and could serve as new pharmacological biomarkers for the therapeutic response of UC.

Keywords: Diagnosis; Polyamine metabolisms; Single-cell analysis; Treatment; Ulcerative colitis (UC)

DOI: https://doi.org/10.1038/s41598-024-69322-6

PLoS One. 2024 ;19(8): e0307573

Role of the polyamine transporter PotABCD during biofilm formation by Streptococcus pneumoniae.

Brenda Vieira, Jessica B Alcantara, Giulia Destro, Maria E S Guerra, Sheila Oliveira, Carolina A Lima, Giovanna B Longato, Anders P Hakansson, Luciana C Leite, Michelle Darrieux, Thiago R Converso.

Streptococcus pneumoniae is a bacterium of great global importance, responsible for more than one million deaths per year. This bacterium is commonly acquired in the first years of life and colonizes the upper respiratory tract asymptomatically by forming biofilms that persist for extended times in the nasopharynx. However, under conditions that alter the bacterial environment, such as viral infections, pneumococci can escape from the biofilm and invade other niches, causing local and systemic disease of varying severity. The polyamine transporter PotABCD is required for optimal survival of the organism in the host. Immunization of mice with recombinant PotD can reduce subsequent bacterial colonization. PotD has also been suggested to be involved in pneumococcal biofilm development. Therefore, in this study we aimed to elucidate the role of PotABCD and polyamines in pneumococcal biofilm formation. First, the formation of biofilms was evaluated in the presence of exogenous polyamines-the substrate transported by PotABCD-added to culture medium. Next, a potABCD-negative strain was used to determine biofilm formation in different model systems using diverse levels of complexity from abiotic surface to cell substrate to in vivo animal models and was compared with its wild-type strain. The results showed that adding more polyamines to the medium stimulated biofilm formation, suggesting a direct correlation between polyamines and biofilm formation. Also, deletion of potABCD operon impaired biofilm formation in all models tested. Interestingly, more differences between wild-type and mutant strains were observed in the more complex model, which emphasizes the significance of employing more physiological models in studying biofilm formation.

DOI: https://doi.org/10.1371/journal.pone.0307573

Cell Oncol (Dordr). 2024 Aug 08.

Disrupting YAP1-mediated glutamine metabolism induces synthetic lethality alongside ODC1 inhibition in osteosarcoma.

Hongsheng Wang, Yining Tao, Jing Han, Jiakang Shen, Haoran Mu, Zhuoying Wang, Jinzeng Wang, Xinmeng Jin, Qi Zhang, Yuqin Yang, Jun Lin, Mengxiong Sun, Xiaojun Ma, Ling Ren, Amy K LeBlanc, Jing Xu, Yingqi Hua, Wei Sun.

PURPOSE: Osteosarcoma, a highly malignant primary bone tumor primarily affecting adolescents, frequently develops resistance to initial chemotherapy, leading to metastasis and limited treatment options. Our study aims to uncover novel therapeutic targets for metastatic and recurrent osteosarcoma.
METHODS: In this study, we proved the potential of modulating the YAP1-regulated glutamine metabolic pathway to augment the response of OS to DFMO. We initially employed single-cell transcriptomic data to gauge the activation level of polyamine metabolism in MTAP-deleted OS patients. This was further substantiated by transcriptome sequencing data from recurrent and non-recurrent patient tissues, confirming the activation of polyamine metabolism in progressive OS. Through high-throughput drug screening, we pinpointed CIL56, a YAP1 inhibitor, as a promising candidate for a combined therapeutic strategy with DFMO. In vivo, we utilized PDX and CDX models to validate the therapeutic efficacy of this drug combination. In vitro, we conducted western blot analysis, qPCR analysis, immunofluorescence staining, and PuMA experiments to monitor alterations in molecular expression, distribution, and tumor metastasis capability. We employed CCK-8 and colony formation assays to assess the proliferative capacity of cells in the experimental group. We used flow cytometry and reactive oxygen probes to observe changes in ROS and glutamine metabolism within the cells. Finally, we applied RNA-seq in tandem with metabolomics to identify metabolic alterations in OS cells treated with a DFMO and CIL56 combination. This enabled us to intervene and validate the role of the YAP1-mediated glutamine metabolic pathway in DFMO resistance.
RESULTS: Through single-cell RNA-seq data analysis, we pinpointed a subset of late-stage OS cells with significantly upregulated polyamine metabolism. This upregulation was further substantiated by transcriptomic profiling of recurrent and non-recurrent OS tissues. High-throughput drug screening revealed a promising combination strategy involving DFMO and CIL56. DFMO treatment curbs the phosphorylation of YAP1 protein in OS cells, promoting nuclear entry and initiating the YAP1-mediated glutamine metabolic pathway. This reduces intracellular ROS levels, countering DFMO's anticancer effect. The therapeutic efficacy of DFMO can be amplified both in vivo and in vitro by combining it with the YAP1 inhibitor CIL56 or the glutaminase inhibitor CB-839. This underscores the significant potential of targeting the YAP1-mediated glutamine metabolic pathway to enhance efficacy of DFMO.
CONCLUSION: Our findings elucidate YAP1-mediated glutamine metabolism as a crucial bypass mechanism against DFMO, following the inhibition of polyamine metabolism. Our study provides valuable insights into the potential role of DFMO in an "One-two Punch" therapy of metastatic and recurrent osteosarcoma.

Keywords: Glutamine metabolism; High-throughput drug screening; Osteosarcoma; Polyamine metabolism; Single-cell RNA-seq; YAP1

DOI: https://doi.org/10.1007/s13402-024-00967-1

Theranostics. 2024 ;14(11): 4218-4239

Aryl hydrocarbon receptor confers protection against macrophage pyroptosis and intestinal inflammation through regulating polyamine biosynthesis.

Yajing Gao, Kwei-Yan Liu, Wenfeng Xiao, Xueru Xie, Qiuyan Liang, Zikun Tu, Lan Yang, Hongmiao Yu, Haiyan Guo, Saihua Huang, Xiao Han, Jinrong Fu, Yufeng Zhou.

Rationale: The aryl hydrocarbon receptor (AhR) functions in the regulation of intestinal inflammation, but knowledge of the underlying mechanisms in innate immune cells is limited. Here, we investigated the role of AhR in modulating the functions of macrophages in inflammatory bowel disease pathogenesis. Methods: The cellular composition of intestinal lamina propria CD45+ leukocytes in a dextran sulfate sodium (DSS)-induced mouse colitis model was determined by single-cell RNA sequencing. Macrophage pyroptosis was quantified by analysis of lactate dehydrogenase release, propidium iodide staining, enzyme-linked immunosorbent assay, western blot, and flow cytometry. Differentially expressed genes were confirmed by RNA-seq, RT-qPCR, luciferase assay, chromatin immunoprecipitation, and immunofluorescence staining. Results: AhR deficiency mediated dynamic remodeling of the cellular composition of intestinal lamina propria (LP) CD45+ immune cells in a colitis model, with a significant increase in monocyte-macrophage lineage. Mice with AhR deficiency in myeloid cells developed more severe dextran sulfate sodium induced colitis, with concomitant increased macrophage pyroptosis. Dietary supplementation with an AhR pre-ligand, indole-3-carbinol, conferred protection against colitis while protection failed in mice lacking AhR in myeloid cells. Mechanistically, AhR signaling inhibited macrophage pyroptosis by promoting ornithine decarboxylase 1 (Odc1) transcription, to enhance polyamine biosynthesis. The increased polyamine, particularly spermine, inhibited NLRP3 inflammasome assembly and subsequent pyroptosis by suppressing K+ efflux. AHR expression was positively correlated with ODC1 in intestinal mucosal biopsies from patients with ulcerative colitis. Conclusions: These findings suggest a functional role for the AhR/ODC1/polyamine axis in maintaining intestinal homeostasis, providing potential targets for treatment of inflammatory bowel disease.

Keywords: Aryl hydrocarbon receptor; ODC1; macrophage; pyroptosis; spermine

DOI: https://doi.org/10.7150/thno.95749

Clin Transl Med. 2024 Aug;14(8): e1791

Oocyte-specific deletion of eukaryotic translation initiation factor 5 causes apoptosis of mouse oocytes within the early-growing follicles by mitochondrial fission defect-reactive oxygen species-DNA damage.

Weiyong Wang, Huiyu Liu, Shuang Liu, Tiantian Hao, Ying Wei, Hongwei Wei, Wenjun Zhou, Xiaodan Zhang, Xiaoqiong Hao, Meijia Zhang.

BACKGROUND: Mutations in several translation initiation factors are closely associated with premature ovarian insufficiency (POI), but the underlying pathogenesis remains largely unknown.
METHODS AND RESULTS: We generated eukaryotic translation initiation factor 5 (Eif5) conditional knockout mice aiming to investigate the function of eIF5 during oocyte growth and follicle development. Here, we demonstrated that Eif5 deletion in mouse primordial and growing oocytes both resulted in the apoptosis of oocytes within the early-growing follicles. Further studies revealed that Eif5 deletion in oocytes downregulated the levels of mitochondrial fission-related proteins (p-DRP1, FIS1, MFF and MTFR) and upregulated the levels of the integrated stress response-related proteins (AARS1, SHMT2 and SLC7A1) and genes (Atf4, Ddit3 and Fgf21). Consistent with this, Eif5 deletion in oocytes resulted in mitochondrial dysfunction characterized by elongated form, aggregated distribution beneath the oocyte membrane, decreased adenosine triphosphate content and mtDNA copy numbers, and excessive accumulation of reactive oxygen species (ROS) and mitochondrial superoxide. Meanwhile, Eif5 deletion in oocytes led to a significant increase in the levels of DNA damage response proteins (γH2AX, p-CHK2 and p-p53) and proapoptotic proteins (PUMA and BAX), as well as a significant decrease in the levels of anti-apoptotic protein BCL-xL.
CONCLUSION: These findings indicate that Eif5 deletion in mouse oocytes results in the apoptosis of oocytes within the early-growing follicles via mitochondrial fission defects, excessive ROS accumulation and DNA damage. This study provides new insights into pathogenesis, genetic diagnosis and potential therapeutic targets for POI.
KEY POINTS: Eif5 deletion in oocytes leads to arrest in oocyte growth and follicle development. Eif5 deletion in oocytes impairs the translation of mitochondrial fission-related proteins, followed by mitochondrial dysfunction. Depletion of Eif5 causes oocyte apoptosis via ROS accumulation and DNA damage response pathway.

Keywords: POI; eIF5; follicle development; mitochondrial fission; oocyte growth

DOI: https://doi.org/10.1002/ctm2.1791