Phytate as a phosphorus nutrient with impacts on iron stress-related gene expression for phytoplankton: insights from diatom Phaeodactylum tricornutum

Author(s):  
Jiashun Li ◽  
Kaidian Zhang ◽  
Xin Lin ◽  
Ling Li ◽  
Senjie Lin

Phytoplankton have evolved a capability to acquire phosphorus (P) from dissolved organic phosphorus (DOP) since the preferred form, dissolved inorganic phosphate (DIP, or Pi), is often limited in parts of the ocean. Phytic acid (PA) is abundantly synthesized in plants and rich in excreta of animals, potentially enriching the DOP pool in coastal oceans. However, whether and how PA may be used by phytoplankton are poorly understood. Here, we investigated PA utilization and underlying metabolic pathways in the diatom model Phaeodactylum tricornutum . The physiological results showed that P. tricornutum could utilize PA as a sole source of P nutrient to support growth. Meanwhile, the replacement of PA for DIP also caused changes in multiple cellular processes such as inositol phosphate metabolism, photosynthesis, and signal transduction. These results suggest that PA is bioavailable to P. tricornutum and can directly participate the metabolic pathways of PA-grown cells. However, our data showed that the utilization of PA was markedly less efficient than that of DIP, and PA-grown cells exhibited P and iron (Fe) nutrient stress signals. Implicated in these findings is the potential of complicated responses of phytoplankton to an ambient DOP species, which calls for more systematic investigation. IMPORTANCE PA is abundant in plants, and cannot be digested by non-ruminant animals. Hence, it is potentially a significant component of the DOP pool in the coastal waters. Despite the potential importance, there is little information about its bioavailability to phytoplankton as a source of P nutrient and if so what molecular mechanisms are involved. In this study, we found that part of PA could be utilized by the diatom P. tricornutum to support growth, and another portion of PA can act as a substrate directly participating in various metabolism pathways and cellular processes. However, our physiological and transcriptomic data show that PA-grown cells still exhibited signs of P stress and potential Fe stress. These results have significant implications in phytoplankton P nutrient ecology and provide a novel insight into multi-faceted impacts of DOP utilization on phytoplankton nutrition and metabolism.

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiayi Li ◽  
Wenping Zhang ◽  
Ziqiu Lin ◽  
Yaohua Huang ◽  
Pankaj Bhatt ◽  
...  

Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter, Bacillus, Vagococcus, Burkholderia, Micrococcus, Stenotrophomonas, and Pseudomonas and fungal genera Aspergillus, Pycnoporus, Pluteus, Trametes, Neurospora, Cunninghamella, and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2260
Author(s):  
Amanda Fuchs ◽  
Isaac Miller ◽  
Sage Schiller ◽  
Mary Ammons ◽  
Brian Eilers ◽  
...  

Macrophages (MΦs) are prevalent innate immune cells, present throughout human bodily tissues where they orchestrate innate and adaptive immune responses to maintain cellular homeostasis. MΦs have the capacity to display a wide array of functional phenotypes due to different microenvironmental cues, particularly soluble bacterial secretory products. Recent evidence has emerged demonstrating that metabolism supports MΦ function and plasticity, in addition to energy and biomolecular precursor production. In this study, 1D 1H-NMR-based metabolomics was used to identify the metabolic pathways that are differentially altered following primary human monocyte-derived MΦ exposure to P. aeruginosa planktonic- and biofilm-conditioned media (PCM and BCM). Metabolic profiling of PCM- and BCM-exposed MΦs indicated a significant increase in glycolytic metabolism, purine biosynthesis, and inositol phosphate metabolism. In addition, these metabolic patterns suggested that BCM-exposed MΦs exhibit a hyperinflammatory metabolic profile with reduced glycerol metabolism and elevated catabolism of lactate and amino acids, relative to PCM-exposed MΦs. Altogether, our study reveals novel findings concerning the metabolic modulation of human MΦs after exposure to secretory microbial products and contributes additional knowledge to the field of immunometabolism in MΦs.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jun Li ◽  
Haiyan Si ◽  
Haitao Du ◽  
Hongxia Guo ◽  
Huanqin Dai ◽  
...  

Abstract Background The aim was to determine the potential association of the gut microbiota composition, especially the abundance of Actinobacteria, as well as the differentiation of functional and resistance genes with age (young adults vs elderly subjects) in China. Results The patterns of relative abundance of all bacteria isolated from fecal samples differed between young adults and elderly subjects, but the alpha diversity (Chao1 P = 0.370, Shannon P = 0.560 and Simpson P = 0.270) and beta diversity (ANOSIM R = 0.031, P = 0.226) were not significantly different. There were 3 Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways (carbon metabolism, inositol phosphate metabolism, and sesquiterpenoid and triterpenoid biosynthesis) and 7 antibiotic resistant genes (ARGs) (macrolide lincosamide-streptogramin B (MLSB), tetracycline, aminoglycoside, sulfonamide, fosmidomycin, lincomycin, and vancomycin) that showed significant differences between the 2 groups (all P < 0.05). The abundance of Actinomycetes was enriched (about 2.4-fold) in young adults. Bifidobacteria dominated in both young adults and elderly subjects, with overall higher abundances in young adults (P > 0.05). Only the Bifidobacterium_dentium species showed significant differences between the 2 groups (P = 0.013), with a higher abundance in elderly subjects but absent in young adults. Conclusions The present study revealed that there were 3 KEGG metabolic pathways and 7 ARGs as well as enhanced Bifidobacterium_dentium species abundance in elderly compared to young subjects.


2020 ◽  
Vol 60 (12) ◽  
pp. 1491
Author(s):  
Chinju Johnson ◽  
Carolyn Fitzsimmons ◽  
Igor Kovalchuk ◽  
John Kastelic ◽  
Jacob Thundathil

Context Selection for residual feed intake (RFI) and its impact on male reproductive development has had mixed reviews in the past. Our previous studies demonstrated earlier puberty, larger testes and greater percentage of progressively motile sperm in high-RFI bulls. However, the molecular mechanisms within testes of bulls with varying RFI remain unclear. Aims To determine the effect of RFI and pre-natal diet on the expression patterns of testicular genes and use this information to explain differences observed across RFI. Methods The study included 25 purebred-Angus bulls with a genetic background of either high or low RFI and fed either normal or low pre-natal nutrition from 30 to 150 days post conception. After slaughter (17 months), testicular tissue was recovered, and RNA was extracted and sequenced. Key results Of 19218 expressed genes, 17 were differentially expressed for RFI (including PLCD1, INPP4B), with no differences being observed for pre-natal diet or diet × RFI interaction (false discovery rate) &lt; 0.1%). KEGG pathway analysis indicated that differentially expressed genes were associated with inositol phosphate metabolism, and phosphatidylinositol signalling. On the basis of a candidate gene-expression study, IGF1R was upregulated in high-RFI bulls (P &lt; 0.1). Conclusions Increased expression of IGF1R and lowered PLCD1 and INPP4B expression could activate PI3K–Akt signalling responsible for cell growth, proliferation and steroid metabolism in high-RFI bulls. Implications Selecting bulls for feed efficiency might affect molecular networks associated with reproduction and fertility.


2021 ◽  
Vol 11 (6) ◽  
pp. 513
Author(s):  
Zheng Zhang ◽  
Meng Gu ◽  
Zhongze Gu ◽  
Yan-Ru Lou

Genetic polymorphisms are defined as the presence of two or more different alleles in the same locus, with a frequency higher than 1% in the population. Since the discovery of long non-coding RNAs (lncRNAs), which refer to a non-coding RNA with a length of more than 200 nucleotides, their biological roles have been increasingly revealed in recent years. They regulate many cellular processes, from pluripotency to cancer. Interestingly, abnormal expression or dysfunction of lncRNAs is closely related to the occurrence of human diseases, including cancer and degenerative neurological diseases. Particularly, their polymorphisms have been found to be associated with altered drug response and/or drug toxicity in cancer treatment. However, molecular mechanisms are not yet fully elucidated, which are expected to be discovered by detailed studies of RNA–protein, RNA–DNA, and RNA–lipid interactions. In conclusion, lncRNAs polymorphisms may become biomarkers for predicting the response to chemotherapy in cancer patients. Here we review and discuss how gene polymorphisms of lncRNAs affect cancer chemotherapeutic response. This knowledge may pave the way to personalized oncology treatments.


2021 ◽  
Vol 7 (18) ◽  
pp. eabc6266
Author(s):  
Qi Li ◽  
Ningkun Liu ◽  
Qing Liu ◽  
Xingguo Zheng ◽  
Lu Lu ◽  
...  

Eukaryotic cells contain numerous membraneless organelles that are made from liquid droplets of proteins and nucleic acids and that provide spatiotemporal control of various cellular processes. However, the molecular mechanisms underlying the formation and rapid stress-induced alterations of these organelles are relatively uncharacterized. Here, we investigated the roles of DEAD-box helicases in the formation and alteration of membraneless nuclear dicing bodies (D-bodies) in Arabidopsis thaliana. We uncovered that RNA helicase 6 (RH6), RH8, and RH12 are previously unidentified D-body components. These helicases interact with and promote the phase separation of SERRATE, a key component of D-bodies, and drive the formation of D-bodies through liquid-liquid phase separations (LLPSs). The accumulation of these helicases in the nuclei decreases upon Turnip mosaic virus infections, which couples with the decrease of D-bodies. Our results thus reveal the key roles of RH6, RH8, and RH12 in modulating D-body formation via LLPSs.


2021 ◽  
Vol 22 (14) ◽  
pp. 7390
Author(s):  
Nicole Wesch ◽  
Frank Löhr ◽  
Natalia Rogova ◽  
Volker Dötsch ◽  
Vladimir V. Rogov

Ubiquitin fold modifier 1 (UFM1) is a member of the ubiquitin-like protein family. UFM1 undergoes a cascade of enzymatic reactions including activation by UBA5 (E1), transfer to UFC1 (E2) and selective conjugation to a number of target proteins via UFL1 (E3) enzymes. Despite the importance of ufmylation in a variety of cellular processes and its role in the pathogenicity of many human diseases, the molecular mechanisms of the ufmylation cascade remains unclear. In this study we focused on the biophysical and biochemical characterization of the interaction between UBA5 and UFC1. We explored the hypothesis that the unstructured C-terminal region of UBA5 serves as a regulatory region, controlling cellular localization of the elements of the ufmylation cascade and effective interaction between them. We found that the last 20 residues in UBA5 are pivotal for binding to UFC1 and can accelerate the transfer of UFM1 to UFC1. We solved the structure of a complex of UFC1 and a peptide spanning the last 20 residues of UBA5 by NMR spectroscopy. This structure in combination with additional NMR titration and isothermal titration calorimetry experiments revealed the mechanism of interaction and confirmed the importance of the C-terminal unstructured region in UBA5 for the ufmylation cascade.


Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 136
Author(s):  
Baolong Liu ◽  
Jiujiu Yu

The nucleotide-binding domain and leucine-rich repeat related (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome is a multimeric protein complex that recognizes various danger or stress signals from pathogens, the host, and the environment, leading to activation of caspase-1 and inducing inflammatory responses. This pro-inflammatory protein complex plays critical roles in pathogenesis of a wide range of diseases including neurodegenerative diseases, autoinflammatory diseases, and metabolic disorders. Therefore, intensive efforts have been devoted to understanding its activation mechanisms and to searching for its specific inhibitors. Approximately forty natural compounds with anti-NLRP3 inflammasome properties have been identified. Here, we provide an update about new natural compounds that have been identified within the last three years to inhibit the NLRP3 inflammasome and offer an overview of the underlying molecular mechanisms of their anti-NLRP3 inflammasome activities.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 836
Author(s):  
Ana Quelle-Regaldie ◽  
Daniel Sobrido-Cameán ◽  
Antón Barreiro-Iglesias ◽  
María Jesús Sobrido ◽  
Laura Sánchez

Autosomal recessive ataxias are much less well studied than autosomal dominant ataxias and there are no clearly defined systems to classify them. Autosomal recessive ataxias, which are characterized by neuronal and multisystemic features, have significant overlapping symptoms with other complex multisystemic recessive disorders. The generation of animal models of neurodegenerative disorders increases our knowledge of their cellular and molecular mechanisms and helps in the search for new therapies. Among animal models, the zebrafish, which shares 70% of its genome with humans, offer the advantages of being small in size and demonstrating rapid development, making them optimal for high throughput drug and genetic screening. Furthermore, embryo and larval transparency allows to visualize cellular processes and central nervous system development in vivo. In this review, we discuss the contributions of zebrafish models to the study of autosomal recessive ataxias characteristic phenotypes, behavior, and gene function, in addition to commenting on possible treatments found in these models. Most of the zebrafish models generated to date recapitulate the main features of recessive ataxias.


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