bims-polyam 2024-03-31 papers

bims-polyam

Biomed News

on Polyamines

Issue of 2024–03–31
eight papers selected by
Sebastian J. Hofer, University of Graz

Polyamine release and vesicular polyamine transporter expression in megakaryoblastic cells and platelets.
Enhancing the Spermidine Synthase-Based Polyamine Biosynthetic Pathway to Boost Rapid Growth in Marine Diatom Phaeodactylum tricornutum.
Polyamine Catabolism and Its Role in Renal Injury and Fibrosis in Mice Subjected to Repeated Low-Dose Cisplatin Treatment.
Spermidine attenuates monocrotaline-induced pulmonary arterial hypertension in rats by inhibiting purine metabolism and polyamine synthesis-associated vascular remodeling.
Intrauterine injection of bioengineered hydrogel loaded exosomes derived from HUCM stem cells and spermidine prominently augments the pregnancy rate in thin endometrium rats.
The Development of LAT1 Efflux Agonists as Mechanistic Probes of Cellular Amino Acid Stress.
The MUC1-HIF-1α signaling axis regulates pancreatic cancer pathogenesis through polyamine metabolism remodeling.
Plant regeneration capacity in seeds of three species of Miconia (Melastomataceae) may be related to endogenous polyamine profiles.

Biochim Biophys Acta Gen Subj. 2024 Mar 26. pii: S0304-4165(24)00053-9. [Epub ahead of print]1868(6): 130610

Polyamine release and vesicular polyamine transporter expression in megakaryoblastic cells and platelets.

Mizuki Uehara, Ayaka Fukumoto, Hiroshi Omote, Miki Hiasa.

  Polyamines not only play essential roles in cell growth and function of living organisms but are also released into the extracellular space and function as regulators of chemical transduction, although the cells from which they are released and their mode of release are not well understood. The vesicular polyamine transporter (VPAT), encoded by the SLC18B1 is responsible for the vesicular storage of spermine and spermidine, followed by their vesicular release from secretory cells. Focusing on VPAT will help identify polyamine-secreting cells and new polyamine functions. In this study, we investigated the possible involvement of VPAT in vesicular release of polyamines in MEG-01 clonal megakaryoblastic cells and platelets. RT-PCR, western blotting, and immunohistochemistry revealed VPAT expression in MEG-01 cells. MEG-01 cells secreted polyamines upon A23187 stimulation in the presence of Ca2+, which is temperature-dependent and sensitive to bafilomycin A1. A23187-induced polyamine secretion from MEG-01 cells was reduced by treatment with reserpine, VPAT inhibitors, or VPAT RNA interference. Platelets also expressed VPAT, displaying a punctate distribution, and released spermidine upon A23187 and thrombin stimulation. These findings have demonstrated VPAT-mediated vesicular polyamine release from MEG-01 cells, suggesting the presence of similar vesicular polyamine release mechanisms in platelets.

Keywords:  Megakaryoblast; Platelet; Polyamine; Spermidine; Spermine; Vesicular polyamine transporter

DOI:  https://doi.org/10.1016/j.bbagen.2024.130610
Biomolecules. 2024 Mar 19. pii: 372. [Epub ahead of print]14(3):

Enhancing the Spermidine Synthase-Based Polyamine Biosynthetic Pathway to Boost Rapid Growth in Marine Diatom Phaeodactylum tricornutum.

Hung-Yun Lin, Chung-Hsiao Liu, Yong-Ting Kang, Sin-Wei Lin, Hsin-Yun Liu, Chun-Ting Lee, Yu-Chen Liu, Man-Chun Hsu, Ya-Yun Chien, Shao-Ming Hong, Yun-Hsuan Cheng, Bing-You Hsieh, Han-Jia Lin.

  Diatoms, efficient carbon capture organisms, contribute to 20% of global carbon fixation and 40% of ocean primary productivity, garnering significant attention to their growth. Despite their significance, the synthesis mechanism of polyamines (PAs), especially spermidine (Spd), which are crucial for growth in various organisms, remains unexplored in diatoms. This study reveals the vital role of Spd, synthesized through the spermidine synthase (SDS)-based pathway, in the growth of the diatom Phaeodactylum tricornutum. PtSDS1 and PtSDS2 in the P. tricornutum genome were confirmed as SDS enzymes through enzyme-substrate selectivity assays. Their distinct activities are governed primarily by the Y79 active site. Overexpression of a singular gene revealed that PtSDS1, PtSDS2, and PtSAMDC from the SDS-based synthesis pathway are all situated in the cytoplasm, with no significant impact on PA content or diatom growth. Co-overexpression of PtSDS1 and PtSAMDC proved essential for elevating Spd levels, indicating multifactorial regulation. Elevated Spd content promotes diatom growth, providing a foundation for exploring PA functions and regulation in diatoms.

Keywords:  activity site; diatoms; rapid growth; spermidine synthase

DOI:  https://doi.org/10.3390/biom14030372
Biomedicines. 2024 Mar 13. pii: 640. [Epub ahead of print]12(3):

Polyamine Catabolism and Its Role in Renal Injury and Fibrosis in Mice Subjected to Repeated Low-Dose Cisplatin Treatment.

Kamyar Zahedi, Sharon Barone, Marybeth Brooks, Tracy Murray Stewart, Jackson R Foley, Ashley Nwafor, Robert A Casero, Manoocher Soleimani.

  Cisplatin, a chemotherapeutic agent, can cause nephrotoxic and ototoxic injuries. Using a mouse model of repeated low dose cisplatin (RLDC), we compared the kidneys of cisplatin- and vehicle-treated mice on days 3 (early injury phase) and 35 (late injury/recovery phase) after the final treatment. RNA-seq analyses revealed increases in the expression of markers of kidney injury (e.g., lipocalin 2 and kidney injury molecule 1) and fibrosis (e.g., collagen 1, fibronectin, and vimentin 1) in RLDC mice. In addition, we observed increased expression of polyamine catabolic enzymes (spermidine/spermine N1-acetyltransferase, Sat1, and spermine oxidase, Smox) and decreased expression of ornithine decarboxylase (Odc1), a rate-limiting enzyme in polyamine synthesis in mice subjected to RLDC. Upon confirmation of the RNA-seq results, we tested the hypothesis that enhanced polyamine catabolism contributes to the onset of renal injury and development of fibrosis. To test our hypothesis, we compared the severity of RLDC-induced renal injury and fibrosis in wildtype (WT), Sat1-KO, and Smox-KO mice. Our results suggest that the ablation of polyamine catabolic enzymes reduces the severity of renal injury and that modulation of the activity of these enzymes may protect against kidney damage and fibrosis caused by cisplatin treatment.

Keywords:  chronic kidney injury; cisplatin; fibrosis; nephrotoxicity; polyamine; polyamine catabolism

DOI:  https://doi.org/10.3390/biomedicines12030640
Int Immunopharmacol. 2024 Mar 28. pii: S1567-5769(24)00464-8. [Epub ahead of print]132 111946

Spermidine attenuates monocrotaline-induced pulmonary arterial hypertension in rats by inhibiting purine metabolism and polyamine synthesis-associated vascular remodeling.

Yu-Jing Chen, Han-Fei Li, Fan-Rong Zhao, Miao Yu, Si-Yu Pan, Wen-Ze Sun, Yan-Yan Yin, Tian-Tian Zhu.

  Ensuring the homeostatic integrity of pulmonary artery endothelial cells (PAECs) is essential for combatting pulmonary arterial hypertension (PAH), as it equips the cells to withstand microenvironmental challenges. Spermidine (SPD), a potent facilitator of autophagy, has been identified as a significant contributor to PAECs function and survival. Despite SPD's observed benefits, a comprehensive understanding of its protective mechanisms has remained elusive. Through an integrated approach combining metabolomics and molecular biology, this study uncovers the molecular pathways employed by SPD in mitigating PAH induced by monocrotaline (MCT) in a Sprague-Dawley rat model. The study demonstrates that SPD administration (5 mg/kg/day) significantly corrects right ventricular impairment and pathological changes in pulmonary tissues following MCT exposure (60 mg/kg). Metabolomic profiling identified a purine metabolism disorder in MCT-treated rats, which SPD effectively normalized, conferring a protective effect against PAH progression. Subsequent in vitro analysis showed that SPD (0.8 mM) reduces oxidative stress and apoptosis in PAECs challenged with Dehydromonocrotaline (MCTP, 50 μM), likely by downregulating purine nucleoside phosphorylase (PNP) and modulating polyamine biosynthesis through alterations in S-adenosylmethionine decarboxylase (AMD1) expression and the subsequent production of decarboxylated S-adenosylmethionine (dcSAM). These findings advocate SPD's dual inhibitory effect on PNP and AMD1 as a novel strategy to conserve cellular ATP and alleviate oxidative injuries, thus providing a foundation for SPD's potential therapeutic application in PAH treatment.

Keywords:  Polyamine synthesis; Pulmonary arterial hypertension; Pulmonary artery endothelial cells; Purine metabolism; Spermidine

DOI:  https://doi.org/10.1016/j.intimp.2024.111946
Regen Ther. 2024 Dec;27 63-72

Intrauterine injection of bioengineered hydrogel loaded exosomes derived from HUCM stem cells and spermidine prominently augments the pregnancy rate in thin endometrium rats.

Xiuying Lin, Yanqiu Fang, Xuguang Mi, Jianhua Fu, Shiling Chen, Mengxue Wu, Ningyi Jin.

  The endometrium is essential to the development of embryos and pregnancy. Human umbilical cord mesenchymal stem cells (HUCMSCs) are promising stem cell sources. HUCMSCs self-renew quickly and are painless to collect. Spermidine is an inherent polyamine needed for cellular and molecular processes that regulate physiology and function. HUCMSCs and spermidine (SN) may heal intrauterine adhesions. HUCMSCs were investigated for endometrial repair in rats. Composite hydrogels are used for medical exosome implantation, including their materials, properties, and embedding procedures. This study examined whether bioengineered hydrogel-loaded exosomes from HUCMSCs and spermidine prenatally improved conception rates in mice with poor endometrial lining. The data show that HUCMSC and SN provide a good experimental base for HUCMSC safety and intrauterine treatment in rats. Western blots, exosome structural analysis, pregnancy outcomes, flow cytometry, H&E staining, immunohistochemistry, and immunofluorescence labelling found and recovered the aberrant area. HUCM-derived stem cells and spermidine-derived exosomes biophysically match. These traits strengthen and prolong endometrial function. Pregnant rats with HUCMSC and SN had thinner endometrium. Hydrogel-incorporated HEHUCMSC and SN exosomes may improve IUI in rats with thin endometrium.

Keywords:  Endometrium; Exosomes; Hydrogel; Intrauterine

DOI:  https://doi.org/10.1016/j.reth.2024.02.003
Biomolecules. 2024 Mar 09. pii: 326. [Epub ahead of print]14(3):

The Development of LAT1 Efflux Agonists as Mechanistic Probes of Cellular Amino Acid Stress.

Vandana Sekhar, Houssine Ikhlef, Alexandra Bunea, Viet S Nguyen, Johan Joo, Mukund P Tantak, Holly Moots, Otto Phanstiel.

  Amino acid restriction induces cellular stress and cells often respond via the induction of autophagy. Autophagy or 'self-eating' enables the recycling of proteins and provides the essential amino acids needed for cell survival. Of the naturally occurring amino acids, methionine restriction has pleiotropic effects on cells because methionine also contributes to the intracellular methyl pools required for epigenetic controls as well as polyamine biosynthesis. In this report, we describe the chemical synthesis of four diastereomers of a methionine depletion agent and demonstrate how controlled methionine efflux from cells significantly reduces intracellular methionine, S-adenosylmethionine (SAM), S-adenosyl homocysteine (SAH), and polyamine levels. We also demonstrate that human pancreatic cancer cells respond via a lipid signaling pathway to induce autophagy. The methionine depletion agent causes the large amino acid transporter 1 (LAT1) to preferentially work in reverse and export the cell's methionine (and leucine) stores. The four diastereomers of the lead methionine/leucine depletion agent were synthesized and evaluated for their ability to (a) efflux 3H-leucine from cells, (b) dock to LAT1 in silico, (c) modulate intracellular SAM, SAH, and phosphatidylethanolamine (PE) pools, and (d) induce the formation of the autophagy-associated LC3-II marker. The ability to modulate the intracellular concentration of methionine regardless of exogenous methionine supply provides new molecular tools to better understand cancer response pathways. This information can then be used to design improved therapeutics that target downstream methionine-dependent processes like polyamines.

Keywords:  S-adenosylmethionine (SAM); autophagy; lipid signaling; methionine efflux

DOI:  https://doi.org/10.3390/biom14030326
Proc Natl Acad Sci U S A. 2024 Apr 02. 121(14): e2315509121

The MUC1-HIF-1α signaling axis regulates pancreatic cancer pathogenesis through polyamine metabolism remodeling.

Divya Murthy, Kuldeep S Attri, Voddu Suresh, Girish H Rajacharya, Carlos A Valenzuela, Ravi Thakur, Junzhang Zhao, Surendra K Shukla, Nina V Chaika, Drew LaBreck, Chinthalapally V Rao, Michael A Hollingsworth, Kamiya Mehla, Pankaj K Singh.

  Dysregulation of polyamine metabolism has been implicated in cancer initiation and progression; however, the mechanism of polyamine dysregulation in cancer is not fully understood. In this study, we investigated the role of MUC1, a mucin protein overexpressed in pancreatic cancer, in regulating polyamine metabolism. Utilizing pancreatic cancer patient data, we noted a positive correlation between MUC1 expression and the expression of key polyamine metabolism pathway genes. Functional studies revealed that knockdown of spermidine/spermine N1-acetyltransferase 1 (SAT1), a key enzyme involved in polyamine catabolism, attenuated the oncogenic functions of MUC1, including cell survival and proliferation. We further identified a regulatory axis whereby MUC1 stabilized hypoxia-inducible factor (HIF-1α), leading to increased SAT1 expression, which in turn induced carbon flux into the tricarboxylic acid cycle. MUC1-mediated stabilization of HIF-1α enhanced the promoter occupancy of the latter on SAT1 promoter and corresponding transcriptional activation of SAT1, which could be abrogated by pharmacological inhibition of HIF-1α or CRISPR/Cas9-mediated knockout of HIF1A. MUC1 knockdown caused a significant reduction in the levels of SAT1-generated metabolites, N1-acetylspermidine and N8-acetylspermidine. Given the known role of MUC1 in therapy resistance, we also investigated whether inhibiting SAT1 would enhance the efficacy of FOLFIRINOX chemotherapy. By utilizing organoid and orthotopic pancreatic cancer mouse models, we observed that targeting SAT1 with pentamidine improved the efficacy of FOLFIRINOX, suggesting that the combination may represent a promising therapeutic strategy against pancreatic cancer. This study provides insights into the interplay between MUC1 and polyamine metabolism, offering potential avenues for the development of treatments against pancreatic cancer.

Keywords:  MUC1; SAT1; hypoxia-inducible factors; pancreatic cancer; polyamine biosynthesis

DOI:  https://doi.org/10.1073/pnas.2315509121
Protoplasma. 2024 Mar 26.

Plant regeneration capacity in seeds of three species of Miconia (Melastomataceae) may be related to endogenous polyamine profiles.

Juliana Klostermann Ziemmer, Tadeu Dos Reis de Oliveira, Claudete Santa-Catarina, Leila do Nascimento Vieira, Renato Goldenberg, Hugo Pacheco de Freitas Fraga.

  In plant tissue culture, differences in endogenous levels of species-specific plant growth regulators (PGRs) may explain differences in regenerative capacity. In the case of polyamines (PAs), their dynamics and distribution may vary between species, genotypes, tissues, and developmental pathways, such as sexual reproduction and apomixis. In this study, for the first time, we aimed to assess the impact of varying endogenous PAs levels in seeds from distinct reproductive modes in Miconia spp. (Melastomataceae), on their in vitro regenerative capacity. We quantified the free PAs endogenous content in seeds of Miconia australis (obligate apomictic), Miconia hyemalis (facultative apomictic), and Miconia sellowiana (sexual) and evaluated their in vitro regenerative potential in WPM culture medium supplemented with a combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). The morphogenic responses were characterized by light microscopy and scanning electron microscopy and discussed regarding the endogenous PAs profiles found. Seeds of M. sellowiana presented approximately eight times more putrescine than M. australis, which was associated with a higher percentage of regenerated calluses (76.67%) than M. australis (5.56%). On the other hand, spermine levels were significantly higher in M. australis. Spermine is indicated as an inhibitor of auxin-carrying gene expression, which may have contributed to its lower regenerative capacity under the tested conditions. These findings provide important insights into in vitro morphogenesis mechanisms in Miconia and highlight the significance of endogenous PA levels in plant regeneration. These discoveries can potentially optimize future regeneration protocols in Miconia, a plant group still underexplored in this area.

Keywords:   In vitro regeneration; Miconieae; Putrescine; Spermine

DOI:  https://doi.org/10.1007/s00709-024-01945-y