bims-polyam 2023-12-10 papers

Issue of 2023–12–10
five papers selected by
Sebastian J. Hofer, University of Graz

J Insect Physiol. 2023 Dec 01. pii: S0022-1910(23)00113-0. [Epub ahead of print] 104587

Functional analysis of Ornithine decarboxylase in manipulating the wing dimorphism in Nilaparvata lugens (Stål) (Hemiptera: Delphacidae).

Wan-Xue Li, Jing-Xiang Chen, Chuan-Chuan Zhang, Min-Shi Luo, Wen-Qing Zhang.

The brown planthopper (BPH, Nilaparvata lugens), a major insect pest of rice, can make a shift in wing dimorphism to adapt to complex external environments. Our previous study showed that NlODC (Ornithine decarboxylase in N. lugens) was involved in wing dimorphism of the brown planthopper. Here, further experiments were conducted to reveal possible molecular mechanism of NlODC in manipulating the wing dimorphism. We found that the long-winged rate (LWR) of BPH was significantly reduced after RNAi of NlODC or injection of DFMO (D, L-α-Difluoromethylornithine), and LWR of males and females significantly decreased by 21.7% and 34.6%, respectively. Meanwhile, we also examined the contents of three polyamines under DFMO treatment and found that the contents of putrescine and spermidine were significantly lower compared to the control. After 3rd instar nymphs were injected with putrescine and spermidine, LWR was increased significantly in both cases, and putrescine was a little bit more effective, with 5.6% increase in males and 11.4% in females. Three days after injection of dsNlODC, injection of putrescine and spermidine rescued LWR to the normal levels. In the regulation of wing differentiation in BPH, NlODC mutually antagonistic to NlAkt may act through other signaling pathways rather than the classical insulin signaling pathway. This study illuminated a physiological function of an ODC gene involved in wing differentiation in insects, which could be a potential target for pest control.

Keywords: Nilaparvata lugens; Ornithine decarboxylase; Polyamine; RNAi; Wing dimorphism

DOI: https://doi.org/10.1016/j.jinsphys.2023.104587

Cell Commun Signal. 2023 Dec 04. 21(1): 348

Polyamines: their significance for maintaining health and contributing to diseases.

Mengjuan Xuan, Xinyu Gu, Juan Li, Di Huang, Chen Xue, Yuting He.

Polyamines are essential for the growth and proliferation of mammalian cells and are intimately involved in biological mechanisms such as DNA replication, RNA transcription, protein synthesis, and post-translational modification. These mechanisms regulate cellular proliferation, differentiation, programmed cell death, and the formation of tumors. Several studies have confirmed the positive effect of polyamines on the maintenance of health, while others have demonstrated that their activity may promote the occurrence and progression of diseases. This review examines a variety of topics, such as polyamine source and metabolism, including metabolism, transport, and the potential impact of polyamines on health and disease. In addition, a brief summary of the effects of oncogenes and signaling pathways on tumor polyamine metabolism is provided. Video Abstract.

Keywords: Cancer; Disease; Mechanism; Oncogene; Polyamine metabolism

DOI: https://doi.org/10.1186/s12964-023-01373-0

Diabetes. 2023 Dec 06. pii: db230148. [Epub ahead of print]

A translational regulatory mechanism mediated by hypusinated eukaryotic initiation factor 5A facilitates beta cell identity and function.

Craig T Connors, Catharina B P Villaca, Emily K Anderson-Baucum, Spencer R Rosario, Caleb D Rutan, Paul J Childress, Leah R Padgett, Morgan A Robertson, Teresa L Mastracci.

As professional secretory cells, beta cells require adaptable mRNA translation to facilitate a rapid synthesis of proteins, including insulin, in response to changing metabolic cues. Specialized mRNA translation programs are essential drivers of cellular development and differentiation. However, in the pancreatic beta cell, the majority of factors identified to promote growth and development function primarily at the level of transcription. Therefore, despite its importance, the regulatory role of mRNA translation in the formation and maintenance of functional beta cells is not well defined. In this study, we have identified a translational regulatory mechanism mediated by the specialized mRNA translation factor eukaryotic initiation factor 5A (eIF5A), which facilitates the maintenance of beta cell identity and function. The mRNA translation function of eIF5A is only active when it is post-translationally modified ("hypusinated") by the enzyme deoxyhypusine synthase (DHPS). We have discovered that the absence of beta cell DHPS in mice reduces the synthesis of proteins critical to beta cell identity and function at the stage of beta cell maturation, leading to a rapid and reproducible onset of diabetes. Therefore, our work has revealed a gatekeeper of specialized mRNA translation that permits the beta cell, a metabolically responsive secretory cell, to maintain the integrity of protein synthesis necessary during times of induced or increased demand.

DOI: https://doi.org/10.2337/db23-0148

Sci Total Environ. 2023 Dec 04. pii: S0048-9697(23)07687-8. [Epub ahead of print] 169057

Enzymatically prepared neoagarooligosaccharides improve gut health and function through promoting the production of spermidine by Faecalibacterium in chickens.

A La Teng Zhu La, Depeng Li, Zhiqian Cheng, Qiu Wen, Die Hu, Xiaolu Jin, Dan Liu, Yuqing Feng, Yuming Guo, Gong Cheng, Yongfei Hu.

Maintaining animal gut health through modulating the gut microbiota is a constant need when antibiotics are not used in animal feed during the food animal production process. Prebiotics is regarded as one of the most promising antibiotic alternatives for such purpose. As an attractive prebiotic, the role and mechanisms of neoagarooligosaccharides (NAOS) in promoting animal growth and gut health have not been elucidated. In this study, we first cloned and expressed marine bacterial β-agarase in yeast to optimize the NAOS preparation and then investigated the role and the underlying mechanisms of the prepared NAOS in improving chicken gut health and function. The marine bacterial β-agarase PDE13B was expressed in Pichia pastoris GS115 and generated even-numbered NAOS. Dietary the prepared NAOS promoted chicken growth and improved intestinal morphology, its barrier, and digestion capabilities, and absorption function. Metagenomic analysis indicated that NAOS modulated the chicken gut microbiota structure and function, and microbial interactions, and promoted the growth of spermidine-producing bacteria especially Faecalibacterium. Through integration of gut metagenome, gut content metabolome, and gut tissue transcriptome, we established connections among NAOS, gut microbes, spermidine, and chicken gut gene expression. The spermidine regulation of genes related to autophagy, immunity, and inflammation was further confirmed in chicken embryo intestinal epithelium cells. We also verified that NAOS can be utilized by Faecalibacterium prausnitzii to grow and produce spermidine in in vitro experiments. Collectively, we provide a systematic investigation of the role of NAOS in regulating gut health and demonstrate the microbial spermidine-mediated mechanism involved in prebiotic effects of NAOS, which lays foundation for future use of NAOS as a new antibiotic alternative in animal production.

Keywords: Antibiotic alternative; Faecalibacterium; Gut microbiota; Neoagarooligosaccharides; Spermidine

DOI: https://doi.org/10.1016/j.scitotenv.2023.169057

Discov Med. 2023 Dec;35(179): 1167-1176

EIF5A2 Promotes Doxorubicin Resistance in Bladder Cancer Cells through the TGF-β Signaling Pathway.

Jinsong Yang, Xue Jiang, Ying Chen, Lisong Teng.

BACKGROUND: Doxorubicin (DOX) is a commonly used chemotherapeutic agent, but bladder cancer (BC) patients often develop resistance that limits therapeutic efficacy. Recent research has demonstrated a link between medication resistance and the expression of eukaryotic translation initiation factor 5A2 (EIF5A2) in tumors. This study aimed to investigate whether EIF5A2 affects the resistance of BC cells to doxorubicin through the transforming growth factor (TGF)-β signaling pathway.
METHODS: Doxorubicin-resistant cells in BC (T24/DOX and 5637/DOX) were constructed, then cell viability was detected by cell counting kit-8 (CCK-8); EIF5A2 mRNA expression was detected using quantitative real-time PCR (qRT-PCR); cell proliferation was detected using clone formation; apoptosis was detected by flow cytometry; and finally, proteins related to the TGF-β signaling pathway (EIF5A2, TGF-β1, p-small mothers against decapentaplegic 2 (Smad2)/Smad2, p-Smad3/Smad3) were detected using western blot.
RESULTS: EIF5A2 was up-regulated in DOX-resistant BC cells, and DOX intervention promoted proliferation and inhibited apoptosis in DOX-resistant BC cells. si-EIF5A2 reversed the above effects. EIF5A2 resulted in DOX resistance by activating the TGF-β pathway, and the TGF-β activator SRI-011381 reversed the inhibitory effect of si-EIF5A2 on DOX resistance.
CONCLUSIONS: EIF5A2 promotes DOX resistance in BC cells through the TGF-β signaling pathway, and EIF5A2 may be a potential counter-resistance therapeutic strategy in BC chemotherapy.

Keywords: EIF5A2; TGF-β; bladder cancer; doxorubicin

DOI: https://doi.org/10.24976/Discov.Med.202335179.113