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Nature Reviews. Cancer Aug 2022The natural mammalian polyamines putrescine, spermidine and spermine are essential for both normal and neoplastic cell function and replication. Dysregulation of... (Review)
Review
The natural mammalian polyamines putrescine, spermidine and spermine are essential for both normal and neoplastic cell function and replication. Dysregulation of metabolism of polyamines and their requirements is common in many cancers. Both clinical and experimental depletion of polyamines have demonstrated their metabolism to be a rational target for therapy; however, the mechanisms through which polyamines can establish a tumour-permissive microenvironment are only now emerging. Recent data indicate that polyamines can play a major role in regulating the antitumour immune response, thus likely contributing to the existence of immunologically 'cold' tumours that do not respond to immune checkpoint blockade. Additionally, the interplay between the microbiota and associated tissues creates a tumour microenvironment in which polyamine metabolism, content and function can all be dramatically altered on the basis of microbiota composition, dietary polyamine availability and tissue response to its surrounding microenvironment. The goal of this Perspective is to introduce the reader to the many ways in which polyamines, polyamine metabolism, the microbiota and the diet interconnect to establish a tumour microenvironment that facilitates the initiation and progression of cancer. It also details ways in which polyamine metabolism and function can be successfully targeted for therapeutic benefit, including specifically enhancing the antitumour immune response.
Topics: Animals; Humans; Mammals; Neoplasms; Polyamines; Putrescine; Spermidine; Spermine; Tumor Microenvironment
PubMed: 35477776
DOI: 10.1038/s41568-022-00473-2 -
Cell Metabolism Nov 2023The intestinal epithelium has a high turnover rate and constantly renews itself through proliferation of intestinal crypt cells, which depends on insufficiently...
The intestinal epithelium has a high turnover rate and constantly renews itself through proliferation of intestinal crypt cells, which depends on insufficiently characterized signals from the microenvironment. Here, we showed that colonic macrophages were located directly adjacent to epithelial crypt cells in mice, where they metabolically supported epithelial cell proliferation in an mTORC1-dependent manner. Specifically, deletion of tuberous sclerosis complex 2 (Tsc2) in macrophages activated mTORC1 signaling that protected against colitis-induced intestinal damage and induced the synthesis of the polyamines spermidine and spermine. Epithelial cells ingested these polyamines and rewired their cellular metabolism to optimize proliferation and defense. Notably, spermine directly stimulated proliferation of colon epithelial cells and colon organoids. Genetic interference with polyamine production in macrophages altered global polyamine levels in the colon and modified epithelial cell proliferation. Our results suggest that macrophages act as "commensals" that provide metabolic support to promote efficient self-renewal of the colon epithelium.
Topics: Mice; Animals; Spermine; Polyamines; Colon; Intestinal Mucosa; Homeostasis; Macrophages; Mechanistic Target of Rapamycin Complex 1
PubMed: 37804836
DOI: 10.1016/j.cmet.2023.09.010 -
Cell Metabolism Mar 2020Continual efferocytic clearance of apoptotic cells (ACs) by macrophages prevents necrosis and promotes injury resolution. How continual efferocytosis is promoted is not...
Continual efferocytic clearance of apoptotic cells (ACs) by macrophages prevents necrosis and promotes injury resolution. How continual efferocytosis is promoted is not clear. Here, we show that the process is optimized by linking the metabolism of engulfed cargo from initial efferocytic events to subsequent rounds. We found that continual efferocytosis is enhanced by the metabolism of AC-derived arginine and ornithine to putrescine by macrophage arginase 1 (Arg1) and ornithine decarboxylase (ODC). Putrescine augments HuR-mediated stabilization of the mRNA encoding the GTP-exchange factor Dbl, which activates actin-regulating Rac1 to facilitate subsequent rounds of AC internalization. Inhibition of any step along this pathway after first-AC uptake suppresses second-AC internalization, whereas putrescine addition rescues this defect. Mice lacking myeloid Arg1 or ODC have defects in efferocytosis in vivo and in atherosclerosis regression, while treatment with putrescine promotes atherosclerosis resolution. Thus, macrophage metabolism of AC-derived metabolites allows for optimal continual efferocytosis and resolution of injury.
Topics: Animals; Apoptosis; Arginase; Arginine; ELAV-Like Protein 1; Gene Deletion; Guanine Nucleotide Exchange Factors; Humans; Jurkat Cells; Macrophages; Male; Mice, Inbred C57BL; Myeloid Cells; Ornithine Decarboxylase; Phagocytosis; Putrescine; RNA Stability; RNA, Messenger; rac1 GTP-Binding Protein
PubMed: 32004476
DOI: 10.1016/j.cmet.2020.01.001 -
Autophagy Aug 2021Spermidine is a natural polyamine, central to cellular homeostasis and growth, that promotes macroautophagy/autophagy. The polyamine pathway is highly conserved from... (Review)
Review
Spermidine is a natural polyamine, central to cellular homeostasis and growth, that promotes macroautophagy/autophagy. The polyamine pathway is highly conserved from bacteria to mammals and spermidine (prominently found in some kinds of aged cheese, wheat germs, nuts, soybeans, and fermented products thereof, among others) is an intrinsic part of the human diet. Apart from nutrition, spermidine is available to mammalian organisms from intracellular biosynthesis and microbial production in the gut. Importantly, externally supplied spermidine (via drinking water or food) prolongs lifespan, activates autophagy, improves mitochondrial function, and refills polyamine pools that decline during aging in various tissues of model organisms, including mice. In two adjacent studies, we explored how dietary spermidine supplementation enhances eEF5/EIF5A hypusination, cerebral mitochondrial function and cognition in aging and mice.
Topics: Aging; Animals; Autophagy; Cognition; Humans; Longevity; Mitochondria; Spermidine
PubMed: 34105442
DOI: 10.1080/15548627.2021.1933299 -
Gastroenterology Mar 2022Because inflammatory bowel disease is increasing worldwide and can lead to colitis-associated carcinoma (CAC), new interventions are needed. We have shown that spermine...
BACKGROUND & AIMS
Because inflammatory bowel disease is increasing worldwide and can lead to colitis-associated carcinoma (CAC), new interventions are needed. We have shown that spermine oxidase (SMOX), which generates spermidine (Spd), regulates colitis. Here we determined whether Spd treatment reduces colitis and carcinogenesis.
METHODS
SMOX was quantified in human colitis and associated dysplasia using quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. We used wild-type (WT) and Smox C57BL/6 mice treated with dextran sulfate sodium (DSS) or azoxymethane (AOM)-DSS as models of colitis and CAC, respectively. Mice with epithelial-specific deletion of Apc were used as a model of sporadic colon cancer. Animals were supplemented or not with Spd in the drinking water. Colonic polyamines, inflammation, tumorigenesis, transcriptomes, and microbiomes were assessed.
RESULTS
SMOX messenger RNA levels were decreased in human ulcerative colitis tissues and inversely correlated with disease activity, and SMOX protein was reduced in colitis-associated dysplasia. DSS colitis and AOM-DSS-induced dysplasia and tumorigenesis were worsened in Smox vs WT mice and improved in both genotypes with Spd. Tumor development caused by Apc deletion was also reduced by Spd. Smox deletion and AOM-DSS treatment were both strongly associated with increased expression of α-defensins, which was reduced by Spd. A shift in the microbiome, with reduced abundance of Prevotella and increased Proteobacteria and Deferribacteres, occurred in Smox mice and was reversed with Spd.
CONCLUSIONS
Loss of SMOX is associated with exacerbated colitis and CAC, increased α-defensin expression, and dysbiosis of the microbiome. Spd supplementation reverses these phenotypes, indicating that it has potential as an adjunctive treatment for colitis and chemopreventive for colon carcinogenesis.
Topics: Adenomatous Polyposis Coli Protein; Animals; Azoxymethane; Carcinogenesis; Colitis; Colitis, Ulcerative; Colon; Colonic Neoplasms; Dextran Sulfate; Gastrointestinal Microbiome; Gene Expression Regulation; Humans; Intestinal Mucosa; Male; Mice; Oxidoreductases Acting on CH-NH Group Donors; Precancerous Conditions; Protective Factors; RNA, Messenger; Severity of Illness Index; Spermidine; Weight Loss; alpha-Defensins; Polyamine Oxidase
PubMed: 34767785
DOI: 10.1053/j.gastro.2021.11.005 -
Cell Aug 2021Metabolism is a major regulator of immune cell function, but it remains difficult to study the metabolic status of individual cells. Here, we present Compass, an...
Metabolism is a major regulator of immune cell function, but it remains difficult to study the metabolic status of individual cells. Here, we present Compass, an algorithm to characterize cellular metabolic states based on single-cell RNA sequencing and flux balance analysis. We applied Compass to associate metabolic states with T helper 17 (Th17) functional variability (pathogenic potential) and recovered a metabolic switch between glycolysis and fatty acid oxidation, akin to known Th17/regulatory T cell (Treg) differences, which we validated by metabolic assays. Compass also predicted that Th17 pathogenicity was associated with arginine and downstream polyamine metabolism. Indeed, polyamine-related enzyme expression was enhanced in pathogenic Th17 and suppressed in Treg cells. Chemical and genetic perturbation of polyamine metabolism inhibited Th17 cytokines, promoted Foxp3 expression, and remodeled the transcriptome and epigenome of Th17 cells toward a Treg-like state. In vivo perturbations of the polyamine pathway altered the phenotype of encephalitogenic T cells and attenuated tissue inflammation in CNS autoimmunity.
Topics: Acetyltransferases; Adenosine Triphosphate; Aerobiosis; Algorithms; Animals; Autoimmunity; Chromatin; Citric Acid Cycle; Cytokines; Eflornithine; Encephalomyelitis, Autoimmune, Experimental; Epigenome; Fatty Acids; Glycolysis; Jumonji Domain-Containing Histone Demethylases; Mice, Inbred C57BL; Mitochondrial Membrane Transport Proteins; Models, Biological; Oxidation-Reduction; Putrescine; Single-Cell Analysis; T-Lymphocytes, Regulatory; Th17 Cells; Transcriptome; Mice
PubMed: 34216539
DOI: 10.1016/j.cell.2021.05.045 -
Annual Review of Biochemistry Jun 2023The polyamines putrescine, spermidine, and spermine are abundant polycations of vital importance in mammalian cells. Their cellular levels are tightly regulated by... (Review)
Review
The polyamines putrescine, spermidine, and spermine are abundant polycations of vital importance in mammalian cells. Their cellular levels are tightly regulated by degradation and synthesis, as well as by uptake and export. Here, we discuss the delicate balance between the neuroprotective and neurotoxic effects of polyamines in the context of Parkinson's disease (PD). Polyamine levels decline with aging and are altered in patients with PD, whereas recent mechanistic studies on ATP13A2 (PARK9) demonstrated a driving role of a disturbed polyamine homeostasis in PD. Polyamines affect pathways in PD pathogenesis, such as α-synuclein aggregation, and influence PD-related processes like autophagy, heavy metal toxicity, oxidative stress, neuroinflammation, and lysosomal/mitochondrial dysfunction. We formulate outstanding research questions regarding the role of polyamines in PD, their potential as PD biomarkers, and possible therapeutic strategies for PD targeting polyamine homeostasis.
Topics: Animals; Humans; Parkinson Disease; Polyamines; Neuroprotection; Parkinsonian Disorders; Spermidine; Mammals
PubMed: 37018845
DOI: 10.1146/annurev-biochem-071322-021330 -
Cell Metabolism Aug 2022Alzheimer's disease (AD) is one of the foremost neurodegenerative diseases, characterized by beta-amyloid (Aβ) plaques and significant progressive memory loss. In AD,...
Alzheimer's disease (AD) is one of the foremost neurodegenerative diseases, characterized by beta-amyloid (Aβ) plaques and significant progressive memory loss. In AD, astrocytes are proposed to take up and clear Aβ plaques. However, how Aβ induces pathogenesis and memory impairment in AD remains elusive. We report that normal astrocytes show non-cyclic urea metabolism, whereas Aβ-treated astrocytes show switched-on urea cycle with upregulated enzymes and accumulated entering-metabolite aspartate, starting-substrate ammonia, end-product urea, and side-product putrescine. Gene silencing of astrocytic ornithine decarboxylase-1 (ODC1), facilitating ornithine-to-putrescine conversion, boosts urea cycle and eliminates aberrant putrescine and its toxic byproducts ammonia and HO and its end product GABA to recover from reactive astrogliosis and memory impairment in AD. Our findings implicate that astrocytic urea cycle exerts opposing roles of beneficial Aβ detoxification and detrimental memory impairment in AD. We propose ODC1 inhibition as a promising therapeutic strategy for AD to facilitate removal of toxic molecules and prevent memory loss.
Topics: Alzheimer Disease; Ammonia; Amyloid beta-Peptides; Astrocytes; Humans; Hydrogen Peroxide; Memory Disorders; Plaque, Amyloid; Putrescine; Urea
PubMed: 35738259
DOI: 10.1016/j.cmet.2022.05.011 -
The Journal of Allergy and Clinical... Jan 2021The cross-talk between the host and its microbiota plays a key role in the promotion of health. The production of metabolites such as polyamines by intestinal-resident...
BACKGROUND
The cross-talk between the host and its microbiota plays a key role in the promotion of health. The production of metabolites such as polyamines by intestinal-resident bacteria is part of this symbiosis shaping host immunity. The polyamines putrescine, spermine, and spermidine are abundant within the gastrointestinal tract and might substantially contribute to gut immunity.
OBJECTIVE
We aimed to characterize the polyamine spermidine as a modulator of T-cell differentiation and function.
METHODS
Naive T cells were isolated from wild-type mice or cord blood from healthy donors and submitted to polarizing cytokines, with and without spermidine treatment, to evaluate CD4 T-cell differentiation in vitro. Moreover, mice were subjected to oral supplementation of spermidine, or its precursor l-arginine, to assess the frequency and total numbers of regulatory T (Treg) cells in vivo.
RESULTS
Spermidine modulates CD4 T-cell differentiation in vitro, preferentially committing naive T cells to a regulatory phenotype. After spermidine treatment, activated T cells lacking the autophagy gene Atg5 fail to upregulate Foxp3 to the same extent as wild-type cells. These results indicate that spermidine's polarizing effect requires an intact autophagic machinery. Furthermore, dietary supplementation with spermidine promotes homeostatic differentiation of Treg cells within the gut and reduces pathology in a model of T-cell transfer-induced colitis.
CONCLUSION
Altogether, our results highlight the beneficial effects of spermidine, or l-arginine, on gut immunity by promoting Treg cell development.
Topics: Animals; Cell Differentiation; Colitis; Immunity, Mucosal; Mice; Mice, Inbred BALB C; Mice, Knockout; Spermidine; T-Lymphocytes, Regulatory
PubMed: 32407834
DOI: 10.1016/j.jaci.2020.04.037 -
Aging Apr 2020The natural polyamine spermidine and spermine have been reported to ameliorate aging and aging-induced dementia. However, the mechanism is still confused. An aging...
The natural polyamine spermidine and spermine have been reported to ameliorate aging and aging-induced dementia. However, the mechanism is still confused. An aging model, the senescence accelerated mouse-8 (SAMP8), was used in this study. Novel object recognition and the open field test results showed that oral administration of spermidine, spermine and rapamycin increased discrimination index, modified number, inner squares distance and times. Spermidine and spermine increased the activity of SOD, and decreased the level of MDA in the aging brain. Spermidine and spermine phosphorylate AMPK and regulate autophagy proteins (LC3, Beclin 1 and p62). Spermidine and spermine balanced mitochondrial and maintain energy for neuron, with the regulation of MFN1, MFN2, DRP1, COX IV and ATP. In addition, western blot results (Bcl-2, Bax and Caspase-3, NLRP3, IL-18, IL-1β) showed that spermidine and spermine prevented apoptosis and inflammation, and elevate the expression of neurotrophic factors, including NGF, PSD95and PSD93 and BDNF in neurons of SAMP8 mice. These results indicated that the effect of spermidine and spermine on anti-aging is related with improving autophagy and mitochondrial function.
Topics: Animals; Autophagy; Brain; Cellular Senescence; Dementia; Disease Models, Animal; Mice; Mitochondria; Oxidative Stress; Spermidine; Spermine
PubMed: 32268299
DOI: 10.18632/aging.103035