bims-polyam 2022-03-27 papers

Issue of 2022‒03‒27
seven papers selected by
Sebastian J. Hofer
University of Graz

Microbiol Spectr. 2022 Mar 22. e0017022

Modulation of Gut Microbiota Metabolism in Obesity-Related Type 2 Diabetes Reduces Osteomyelitis Severity.

Tina I Bui, Ann Lindley Gill, Robert A Mooney, Steven R Gill.

Staphylococcus aureus is an opportunistic pathogen causing osteomyelitis through hematogenous seeding or contamination of implants and open wounds following orthopedic surgeries. The severity of S. aureus-mediated osteomyelitis is enhanced in obesity-related type 2 diabetes (obesity/T2D) due to chronic inflammation impairing both adaptive and innate immunity. Obesity-induced inflammation is linked to gut dysbiosis, with modification of the gut microbiota by high-fiber diets leading to a reduction in the symptoms and complications of obesity/T2D. However, our understanding of the mechanisms by which modifications of the gut microbiota alter host infection responses is limited. To address this gap, we monitored tibial S. aureus infections in obese/T2D mice treated with the inulin-like fructan fiber oligofructose. Treatment with oligofructose significantly decreased S. aureus colonization and lowered proinflammatory signaling postinfection in obese/T2D mice, as observed by decreased circulating inflammatory cytokines (tumor necrosis factor-α [TNF-α]) and chemokines (interferon-γ-induced protein 10 kDa [IP-10], keratinocyte-derived chemokine [KC], monokine induced by interferon-γ [MIG], monocyte chemoattractant protein-1 [MCP-1], and regulated upon activation, normal T cell expressed and presumably secreted [RANTES]), indicating partial reduction in inflammation. Oligofructose markedly shifted diversity in the gut microbiota of obese/T2D mice, with notable increases in the anti-inflammatory bacterium Bifidobacterium pseudolongum. Analysis of the cecum and plasma metabolome suggested that polyamine production was increased, specifically spermine and spermidine. Oral administration of these polyamines to obese/T2D mice resulted in reduced infection severity similar to oligofructose supplementation, suggesting that polyamines can mediate the beneficial effects of fiber on osteomyelitis severity. These results demonstrate the contribution of gut microbiota metabolites to the control of bacterial infections distal to the gut and polyamines as an adjunct therapeutic for osteomyelitis in obesity/T2D. IMPORTANCE Individuals with obesity-related type 2 diabetes (obesity/T2D) are at a five times increased risk for invasive Staphylococcus aureus osteomyelitis (bone infection) following orthopedic surgeries. With increasing antibiotic resistance and limited discoveries of novel antibiotics, it is imperative that we explore other avenues for therapeutics. In this study, we demonstrated that the dietary fiber oligofructose markedly reduced osteomyelitis severity and hyperinflammation following acute prosthetic joint infections in obese/T2D mice. Reduced infection severity was associated with changes in gut microbiota composition and metabolism, as indicated by increased production of natural polyamines in the gut and circulating plasma. This work identifies a novel role for the gut microbiome in mediating control of bacterial infections and polyamines as beneficial metabolites involved in improving the obesity/T2D host response to osteomyelitis. Understanding the impact of polyamines on host immunity and mechanisms behind decreasing susceptibility to severe implant-associated osteomyelitis is crucial to improving treatment strategies for this patient population.

Keywords: Staphylococcus aureus; gut microbiota; obesity; oligofructose; osteomyelitis; polyamines; type 2 diabetes

DOI: https://doi.org/10.1128/spectrum.00170-22

Int Immunopharmacol. 2022 Mar 16. pii: S1567-5769(22)00186-2. [Epub ahead of print]107 108702

Spermine alleviates experimental autoimmune encephalomyelitis via regulating T cell activation and differentiation.

Ruting Zheng, Miaomiao Kong, Siwei Wang, Bingqing He, Xin Xie.

Multiple sclerosis (MS) is a chronic neuroinflammatory disease which causes demyelination, axonal damage and even disability. Th1 and Th17 cells, more precisely, the IFNγ/IL17a double producing CD4+ T cells, have been known to play critical roles in the pathogenesis of MS and EAE, a mouse model of MS. Polyamines not only regulate the immune system, but also are essential for the normal function of the central nervous system (CNS). In this study, we demonstrate that the supplementation of spermine (SPM), a biogenic polyamine, significantly suppresses EAE progression in both preventative and therapeutic ways. Further study suggests that spermine significantly reduces IFNγ+/IL17a-, IFNγ-/IL17a+ and IFNγ+/IL17a+ cells in periphery, and thus reducing the infiltration of these pathogenic cells into the CNS. In vitro, spermine has been shown to suppress the activation and proliferation of CD4+ T cells and also significantly impede the polarization of T effector cells in a dose-dependent manner, accompanied by the inhibition of ERK phosphorylation. Consistently, a number of MEK/ERK inhibitors (including PD0325901, FR180204 and selumetinib) have been found to mimic the effects of spermine in inhibiting CD4+ T cell activation and T effector cell differentiation. Collectively, spermine alleviates EAE progression by inhibiting CD4+ T cells activation and T effector cell differentiation in a MAPK/ERK-dependent manner, suggesting this pathway might be a target to develop effective therapies for MS.

Keywords: EAE; ERK; MAPK pathway; Multiple Sclerosis; Polyamines; Spermine; Th1; Th17

DOI: https://doi.org/10.1016/j.intimp.2022.108702

Front Microbiol. 2022 ;13 842403

Production of Putrescine and Cadaverine by Paucilactobacillus wasatchensis.

Hélène Berthoud, Daniel Wechsler, Stefan Irmler.

Lactic acid bacteria (LAB) play a key role in many food fermentations. However, some LAB species can also cause food spoilage, e.g., through the formation of biogenic amines. Paucilactobacillus wasatchensis is a LAB that causes late gas production in Cheddar cheese, the molecular causes of which are not fully understood. This study reports on the ability of P. wasatchensis WDC04 to produce cadaverine and putrescine in broth supplemented with lysine and ornithine, as well as in a model cheese. The raclette-type semi-hard cheese produced with P. wasatchensis as an adjunct culture contained 1,085 mg kg-1 of cadaverine and 304 mg kg-1 of putrescine after 120 days of ripening. We identified two ornithine decarboxylase genes (odc) and a putrescine-ornithine antiporter gene (potE) in the genome sequence of P. wasatchensis. We could show that the two odc genes, which are located on two contigs, are contiguous and form the genetic cluster odc2-odc1-potE. Alignment searches showed that similar gene clusters exist in the genomes of Levilactobacillus paucivorans DSMZ22467, Lentilactobacillus kribbianus YH-lac9, Levilactobacillus hunanensis 151-2B, and Levilactobacillus lindianensis 220-4. More amino acid sequence comparisons showed that Odc1 and Odc2 shared 72 and 69% identity with a lysine and ornithine decarboxylase from Ligilactobacillus saerimneri 30a, respectively. To clarify the catalytic activities of both enzymes, the odc-coding genes were cloned and heterologously expressed as His-tagged fusion protein. The purified Odc1 protein decarboxylated lysine into cadaverine, while the recombinant Odc2 protein preferentially produced putrescine from ornithine but also exhibited low lysine decarboxylating activity. Both enzymes were active at pH of 5.5, a value often found in cheese. To our knowledge, this is only the second lysine decarboxylase in LAB whose function has been verified. The tandem arrangement of the genes in a single cluster suggests a gene duplication, evolving the ability to metabolize more amino. Divergent substrate preferences highlight the necessity of verifying the functions of genes, in addition to automatic annotation based on sequence similarity. Acquiring new biochemical data allows better predictive models and, in this case, more accurate biogenic amine production potential for LAB strains and microbiomes.

Keywords: Lactobacillus; Paucilactobacillus wasatchensis; biogenic amines; cadaverine; cheese; lysine decarboxylase; ornithine decarboxylase; putrescine

DOI: https://doi.org/10.3389/fmicb.2022.842403

Int J Mol Sci. 2022 Mar 10. pii: 2971. [Epub ahead of print]23(6):

Putrescine: A Key Metabolite Involved in Plant Development, Tolerance and Resistance Responses to Stress.

Ana Isabel González-Hernández, Loredana Scalschi, Begonya Vicedo, Emilio Luis Marcos-Barbero, Rosa Morcuende, Gemma Camañes.

Putrescine (Put) is the starting point of the polyamines (PAs) pathway and the most common PA in higher plants. It is synthesized by two main pathways (from ornithine and arginine), but recently a third pathway from citrulline was reported in sesame plants. There is strong evidence that Put may play a crucial role not only in plant growth and development but also in the tolerance responses to the major stresses affecting crop production. The main strategies to investigate the involvement of PA in plant systems are based on the application of competitive inhibitors, exogenous PAs treatments, and the most efficient approaches based on mutant and transgenic plants. Thus, in this article, the recent advances in understanding the role of this metabolite in plant growth promotion and protection against abiotic and biotic stresses will be discussed to provide an overview for future research.

Keywords: abiotic stress; biotic stress; plant growth; putrescine

DOI: https://doi.org/10.3390/ijms23062971

Metabolites. 2022 Mar 11. pii: 240. [Epub ahead of print]12(3):

Targeting Arginine in COVID-19-Induced Immunopathology and Vasculopathy.

William Durante.

Coronavirus disease 2019 (COVID-19) represents a major public health crisis that has caused the death of nearly six million people worldwide. Emerging data have identified a deficiency of circulating arginine in patients with COVID-19. Arginine is a semi-essential amino acid that serves as key regulator of immune and vascular cell function. Arginine is metabolized by nitric oxide (NO) synthase to NO which plays a pivotal role in host defense and vascular health, whereas the catabolism of arginine by arginase to ornithine contributes to immune suppression and vascular disease. Notably, arginase activity is upregulated in COVID-19 patients in a disease-dependent fashion, favoring the production of ornithine and its metabolites from arginine over the synthesis of NO. This rewiring of arginine metabolism in COVID-19 promotes immune and endothelial cell dysfunction, vascular smooth muscle cell proliferation and migration, inflammation, vasoconstriction, thrombosis, and arterial thickening, fibrosis, and stiffening, which can lead to vascular occlusion, muti-organ failure, and death. Strategies that restore the plasma concentration of arginine, inhibit arginase activity, and/or enhance the bioavailability and potency of NO represent promising therapeutic approaches that may preserve immune function and prevent the development of severe vascular disease in patients with COVID-19.

Keywords: COVID-19; arginase; arginine; endothelial dysfunction; immunopathology; nitric oxide synthase; thrombosis; vascular disease

DOI: https://doi.org/10.3390/metabo12030240

Kidney Int. 2022 Mar 22. pii: S0085-2538(22)00209-5. [Epub ahead of print]

The sexual dimorphism of kidney growth in mice and humans.

Denise Laouari, Paul Vergnaud, Takuo Hirose, Mohamad Zaidan, Marion Rabant, Clément Nguyen, Martine Burtin, Christophe Legendre, Patrice Codogno, Gerard Friedlander, Dany Anglicheau, Fabiola Terzi.

Kidney mass and function are sexually determined, but the cellular events and the molecular mechanisms involved in this dimorphism are poorly characterized. By combining female and male mice with castration/replacement experiments, we showed that male mice exhibited kidney overgrowth from five weeks of age. This effect was organ specific, since liver and heart weight were comparable between males and females, regardless of age. Consistently, the androgen receptor was found to be expressed in the kidneys of males, but not in the liver. In growing mice, androgens led to kidney overgrowth by first inducing a burst of cell proliferation and then an increase of cell size. Remarkably, androgens were also required to maintain cell size in adults. In fact, orchiectomy resulted in smaller kidneys in a matter of few weeks. These changes paralleled the changes of the expression of ornithine decarboxylase and cyclin D1, two known mediators of kidney growth, whereas, unexpectedly, mTORC1 and Hippo pathways did not seem to be involved. Androgens also enhanced kidney autophagy, very likely by increasing transcription factor EB nuclear translocation. Functionally, the increase of tubular mass resulted in increased sodium/phosphate transport. These findings were relevant to humans. Remarkably, by studying living gender-paired kidney donors-recipients, we showed that tubular cell size increased three months after transplantation in men as compared to women, regardless of the donor gender. Thus, our results identify novel signaling pathways that may be involved in androgen-induced kidney growth and homeostasis, and suggest that androgens determine kidney size after transplantation.

Keywords: cell signaling; gender dimorphism; kidney growth; kidney transplantation; ornithine decarboxylase

DOI: https://doi.org/10.1016/j.kint.2022.02.027

Biomedicines. 2022 Mar 08. pii: 626. [Epub ahead of print]10(3):

Expression of Spermine Oxidase Is Associated with Colorectal Carcinogenesis and Prognosis of Patients.

Sooyoun Kim, Doyeon Kim, Sanghyun Roh, Inpyo Hong, Hyeongjoo Kim, Tae Sung Ahn, Dong Hyun Kang, Moon Soo Lee, Moo-Jun Baek, Hyoung Jong Kwak, Chang-Jin Kim, Dongjun Jeong.

Uncovering tumor markers of colorectal cancer is important for the early detection and prognosis of the patients. Spermine oxidase (SMOX) is upregulated in various cancers. The present study aims to explore the biologic function and expression patterns of SMOX in colorectal cancer (CRC), the third most common type of cancer worldwide. We used quantitative real-time PCR, Western blot, and in vitro functional studies in four CRC cell lines knocked down by SMOX siRNA and immunohistochemistry in 350 cases of CRC tissues. The results showed that SMOX was overexpressed in CRC cell lines and clinical samples. SMOX overexpression in tumor tissues was an independent prognostic factor, worsening overall survival (p = 0.001). The knock-down of SMOX inhibited CRC cell proliferation, invasion, and soft agar colony formation, uncovering its carcinogenic functions. This study indicated that SMOX overexpression could be an important oncogene in CRC and might serve as a valuable prognostic marker and potential therapeutic target for CRC.

Keywords: SMOX; colorectal cancer (CRC); prognostic marker; therapeutic target

DOI: https://doi.org/10.3390/biomedicines10030626