Whole-transcriptome RNA sequencing reveals CeRNA regulatory network under long-term space composite stress in Rats.

To systematically evaluate the effect of simulated long-term spaceflight composite stress (LSCS) in hippocampus and gain more insights into the transcriptomic landscape and molecular mechanism, we performed whole-transcriptome sequencing based on the control group (Ctrl) and the simulated long-term spaceflight composite stress group (LSCS) from six hippocampus of rats. Subsequently, differential expression analysis was performed on the Ctrl and LSCS groups, followed by enrichment analysis and functional interaction prediction analysis to investigate gene-regulatory circuits in LSCS. In addition, competitive endogenous RNA (ceRNA) network was constructed to gain insights into genetic interaction. The result showed that 276 differentially expressed messenger RNAs (DEmRNAs), 139 differentially expressed long non-coding RNAs (DElncRNAs), 103 differentially expressed circular RNAs (DEcircRNAs), and 52 differentially expressed microRNAs (DEmiRNAs) were found in LSCS samples compared with the controls, which were then subjected to enrichment analysis of Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways to find potential functions. PI3K-Akt signaling pathway and MAPK signaling pathway may play fundamental roles in the pathogenesis of LSCS. A ceRNA network was constructed with the predicted 340 DE pairs, which revealed the interaction roles of 220 DEmiRNA-DEmRNA pairs, 76 DEmiRNA-DElncRNA pairs, and 44 DEmiRNA-DEcircRNA pairs. Further, Thrombospondins2 was found to be a key target among those ceRNAs. Overall, we conducted for the first time a full transcriptomic analysis of the response of hippocampus to the LSCS that involved a potential ceRNA network, thus providing a basis to study the underlying mechanism of the LSCS.

The Effects of DNA Methylation on Cytoplasmic Male Sterility in Sugar Beet.

DNA methylation is widely found in higher plants and can control gene expression by regulation without changing the DNA sequence. In this study, the whole-genome methylation map of sugar beet was constructed by WGBS (whole-genome bisulfite sequencing) technology, and the results of WGBS were verified by bisulfite transformation, indicating that the results of WGBS technology were reliable. In addition, 12 differential methylation genes (DMGs) were identified, which were related to carbohydrate and energy metabolism, pollen wall development, and endogenous hormone regulation. Quantitative real-time PCR (qRT-PCR) showed that 75% of DMG expression levels showed negative feedback with methylation level, indicating that DNA methylation can affect gene expression to a certain extent. In addition, we found hypermethylation inhibited gene expression, which laid a foundation for further study on the molecular mechanism of DNA methylation at the epigenetic level in sugar beet male sterility.

Structural analysis and attenuates hyperuricemic nephropathy of dextran from the Imperata cylindrica Beauv. var. major (Nees) C. E. Hubb.

ICPC-a was from the Imperata cylindrica with a molecular weight of 45 kDa, which was composed of α-D-1,3-Glcp and α-D-1,6-Glcp. The ICPC-a showed thermal stability, maintaining its structural integrity up to 220°C. X-ray diffraction analysis confirmed its amorphous nature, while scanning electron microscopy revealed a layered morphology. ICPC-a significantly ameliorated uric acid stimulation-induced HK-2 cell injury and apoptosis and reduced uric acid levels in mice with hyperuricemic nephropathy. ICPC-a protected against renal injury by inhibiting lipid peroxidation levels, increasing antioxidant damage and defense levels, inhibiting secretion of pro-inflammatory factors, regulating purine metabolism, PI3K-Akt signaling pathway, NF-κB signaling pathway, inflammatory bowel disease, mTOR signaling pathway, and MAPK signaling pathway. These findings indicate that ICPC-a is a promising natural substance with multiple targets, multiple pathways of action, and without toxicity, making it a valuable subject for further research and development.

Acanthopanax senticosus extract alleviates radiation-induced learning and memory impairment based on neurotransmitter-gut microbiota communication.

BACKGROUND: Acanthopanax senticosus (AS) is a medicinal and food plant with many physiological functions, especially nerve protection. Its extract has many functional components, including polysaccharides, flavonoids, saponins, and amino acids. Our previous study indicated that AS extract protected against nerve damage caused by radiation. However, little is known about the gut-brain axis mechanism of AS and its impact on radiation-induced learning and memory impairment. METHOD: In 60 Co-γ ray-irradiated mice, we investigated the changes in behavior, neurotransmitters and gut microbiota after different days of administration of AS extract as a dietary supplement. RESULTS: The AS extract improved learning and memory ability in mice, and the neurotransmitter levels in the hippocampus and colon started to change from the 7th day, which accompanied changes of the gut microbiota, a decreased abundance of Helicobacter on the 7th day and an increased abundance of Lactobacillus on the 28th day. Among the marker bacteria, Ruminococcus and Clostridiales were associated with 5-HT synthesis, and Streptococcus were associated with 5-HT and ACH synthesis. In addition, the AS extract increased the tight junction protein, inhibited inflammation levels in colon, and even increased the relative protein expression of BDNF and NF-κB and decreased the relative protein expression of IκBα in the hippocampus of irradiated mice. CONCLUSION: These results will lay the foundation for further study on the mechanism of the gut-brain axis of AS in preventing radiation-induced learning and memory impairment.

Eleutheroside E supplementation prevents radiation-induced cognitive impairment and activates PKA signaling via gut microbiota.

Radiation affects not only cognitive function but also gut microbiota. Eleutheroside E (EE), a principal active compound of Acanthopanax senticosus, has a certain protective effect on the nervous system. Here, we find a four-week EE supplementation to the 60Co-γ ray irradiated mice improves the cognition and spatial memory impairments along with the protection of hippocampal neurons, remodels the gut microbiota, especially changes of Lactobacillus and Helicobacter, and altered the microbial metabolites including neurotransmitters (GABA, NE, ACH, 5-HT) as well as their precursors. Furthermore, the fecal transplantation of EE donors verifies that EE alleviated cognition and spatial memory impairments, and activates the PKA/CREB/BDNF signaling via gut microbiota. Our findings provide insight into the mechanism of EE effect on the gut-brain axis and underpin a proposed therapeutic value of EE in cognitive and memory impairments induced by radiation.

Combining Proteomics and Metabolomics to Analyze the Effects of Spaceflight on Rice Progeny.

Spaceflight is a special abiotic stress, the biological effect mechanism of which on contemporary rice has been clarified, However, its effect on offspring rice was still unclear. In order to understand the response mechanism of F2 generation plants to space flight, this study used SJ-10 recoverable satellite to carry DN423 rice seeds for 12.5 days in orbit flight. After returning to the ground, the plants were then planted to F2 generation to explore the biological effect mechanism. Our research showed that in the F2 generation of TLS, the rice plant height of the space flight group increased by 33.8%, the ear length and thousand-grain weight decreased by 9.7 and 4.6%, respectively, and the grain number per panicle increased by 6.5%. Moreover, related proteins that control changes in agronomic traits have been identified. The changes of MDA, H2O2, soluble sugar, electron leakage and antioxidant enzyme activity confirmed the stress response in F2 generation plants. ITRAQ and LC-MS technology were used to reveal the change pattern of protein levels and metabolite levels in F2 generation plants, 389 and 405 proteins were identified as differentially abundant proteins in TLS and TS, respectively. In addition, there were 124 and 125 metabolites that changed during these two periods. The proteome and metabolome result further confirmed that the F2 generation plants still retained the memory of space flight stress, and retained the memory of space flight stress through genome instability. Oxidative stress signals activated sugar signals to rebuild metabolic networks to adapt to space flight stress. The reconstruction of energy metabolism, amino acid metabolism, phenylalanine metabolism, and flavonoid metabolism played an important role in the process of adapting to space flight stress. The results of this study broaden the perspective of space biological effects and provide a basis for studying the effects of abiotic stress on plant progeny.

Mechanical Properties and Tensile Model of Hemp-Fiber-Reinforced Poly(butylene adipate-co-terephthalate) Composite.

The preparation of a high-strength biodegradable plastic has always been the focus of academia. Here, we prepared two biodegradable composites using silane coupling-agent-modified hemp fibers (Si-HF) and unmodified hemp fibers (HF) with butylene adipate-co-terephthalate (PBAT), respectively. We compared the differences of Si-HF/PBAT and HF/PBAT in terms of micromorphology, density, mechanical properties, thermal stability and biodegradability. The Si-HF has better interface interaction between the hemp and the PBAT matrix than the HF, which makes Si-HF/PBAT have better tensile properties. Moreover, Si-HF/PBAT has stronger tensile strength and modulus than HF/PBAT. Our results also show that the two composites have good biodegradability. This study provides an important reference for the subsequent development and utilization of hemp fibers.

The Memory of Rice Response to Spaceflight Stress: From the Perspective of Metabolomics and Proteomics.

The stress response of plants to spaceflight has been confirmed in contemporary plants, and plants retained the memory of spaceflight through methylation reaction. However, how the progeny plants adapt to this cross-generational stress memory was rarely reported. Here, we used the ShiJian-10 retractable satellite carrying Dongnong416 rice seeds for a 12.5-day on-orbit flight and planted the F2 generation after returning to the ground. We evaluated the agronomic traits of the F2 generation plants and found that the F2 generation plants had no significant differences in plant height and number of tillers. Next, the redox state in F2 plants was evaluated, and it was found that the spaceflight broke the redox state of the F2 generation rice. In order to further illustrate the stress response caused by this redox state imbalance, we conducted proteomics and metabolomics analysis. Proteomics results showed that the redox process in F2 rice interacts with signal transduction, stress response, and other pathways, causing genome instability in the plant, leading to transcription, post-transcriptional modification, protein synthesis, protein modification, and degradation processes were suppressed. The metabolomics results showed that the metabolism of the F2 generation plants was reshaped. These metabolic pathways mainly included amino acid metabolism, sugar metabolism, cofactor and vitamin metabolism, purine metabolism, phenylpropane biosynthesis, and flavonoid metabolism. These metabolic pathways constituted a new metabolic network. This study confirmed that spaceflight affected the metabolic changes in offspring rice, which would help better understand the adaptation mechanism of plants to the space environment.

Portulaca oleracea L. Extract Alleviated Type 2 Diabetes Via Modulating the Gut Microbiota and Serum Branched-Chain Amino Acid Metabolism.

SCOPE: Portulaca oleracea L. extracts (PE) show hypoglycemic function, but the precise mechanism remains obscure. This study is designed to investigate the association of the antidiabetes effect of PE with the gut microbiota modulation and BCAAs metabolism. METHODS AND RESULTS: The Orbitrap LC-MS to Orbitrap Fusion Lumos Tribrid mass spectrometer is employed to analyze the major compounds in PE. The components of the intestinal microflora in diet-induced/STZ-treated diabetic mice are analyzed by high-throughput 16S rRNA genes sequencing. The results show that PE improves blood glucose and insulin level, increases anti-inflammatory cytokine level, lowers serum branched-chain amino acids (BCAAs), and increases serum glutamine level. PE also protects the mucosal epithelium of the colon and cecum from damage. On the impact of gut microbial composition, PE reduces the Firmicutes to Bacteroidetes ratio and the abundance of the Lachnospiraceae_NK4A136_group, Blautia, Ruminiclostridium_9, Dubosiella, and increases the abundance of the Bacteroides, Akkermansia, and Mucisprillum genera. Bacterial functionality prediction indicates PE potentially inhibits bacterial BCAAs biosynthesis, and promotes the tissue-specific expression of BCAAs catabolic enzyme for reducing BCAAs supplementation. CONCLUSION: These results reveal that PE improving T2D-related biochemical abnormalities is associated not only with gut microbiota modification but also with the tissue-specific expression of BCAAs catabolic enzyme.

Effect of an inulin-type fructan from Platycodon grandiflorum on the intestinal microbiota in rats exposed to PM2.5.

In this study, an inulin-type fructan (PGPI-1-a) was isolated from the roots of Platycodon grandiflorum. PGPI-1-a was composed of (2 â†’ 1)-linked ß-D-fructofuranose (Fruf) and a terminal α-d-glucopyranose (Glcp) with a molecular weight of 12.1 kDa. PM2.5 exposure has brought a great threat to human health in recent years. Therefore, this study explored the effect of PGPI-1-a on the intestinal microbial community structure of rats exposed to PM2.5 using the animal model of PM2.5 inhalation exposure. The results showed that PGPI-1-a could regulate the intestinal microbiota by partly restoring the perturbed levels of Peptoniphilaceae_[G-2] and Lachnospiraceae_[G-2] caused by PM2.5 exposure. In addition, the relative abundance of Butyrivibrio, a butyric acid-producing genera, significantly increased after PGPI-1-a intervention. These results indicated that PGPI-1-a could improve the imbalance of intestinal microbiota due to PM2.5 exposure to a certain extent.

Structure characterization and lipid-lowering activity of a homogeneous heteropolysaccharide from sweet tea (Rubus Suavissmus S. Lee).

Sweet tea (Rubus Suavissmus S. Lee) is consumed as herbal tea in southwestern China, which has multiple functions such as relieving cough, alleviating allergic responses, and clearing away heat. Here we report the structure and lipid-lowering activity of a sweet tea polysaccharide (STP-60a). STP-60a is a homogeneous heteropolysaccharide with a molecular weight of 9.16 × 104 Da, and composed of rhamnose, arabinose, glucose, galactose and glucuronic acid. The main backbone of STP-60a consists of ß-L-Rhap-(1→, →3)-ß-D-Galp-(1→, →4)-ß-D-Glcp-UA-(1→, →3,6)-ß-D-Galp-(1→, →6)-ß-D-Galp-(1→, →3)-4-OAc-ß-L-Arap-(1→, →3)-α-L-Araf-(1→ and the side chain are α-L-Araf-(1→ and →3)-α-D-Glcp-(1→. Using Caenorhabditis elegans (C. elegans) in a high-sugar diet as a model, we found that STP-60a significantly reduced the fat accumulation in the intestine of C. elegans, and extensively affected lipolysis, fatty acid synthesis and ß-oxidation processes. In addition, sbp-1 and nhr-49 were essential for STP-60a to exert a lipid-lowering effect.

Metabolomics Analysis in Different Development Stages on SP0 Generation of Rice Seeds After Spaceflight.

Spaceflight is a special abiotic stress condition. In recent years, it has been confirmed that the spaceflight caused the stress response of rice seeds, and the protein level, transcription level, and methylation level will change during the planting process after returning to the ground. However, the changes at the metabolome level are not very clear. In this study, two kinds of rice seeds, Dongnong423 (DN3) and Dongnong416 (DN6), were carried on the ShiJian-10 retractable satellite (SJ-10) for 12.5 days in orbit, returned to the ground and planted in the field until the three-leaf (TLP) and tillering stage (TS). The results of antioxidant enzyme activity, soluble sugar, and electron leakage rate revealed that the spaceflight caused the stress response of rice. The TLP and TS of DN3 identified 110 and 57 different metabolites, respectively, while the TLP and TS of DN6 identified 104 and 74 different metabolites, respectively. These metabolites included amino acids, sugars, fatty acids, organic acids and secondary metabolites. We used qRT-PCR technology to explore the changes of enzyme genes in the tricarboxylic acid cycle (TCA) and amino acid metabolism pathway. Combined with the results of metabolomics, we determined that during the TLP, the TCA cycle rate of DN3 was inhibited and amino acid metabolism was activated, while the TCA cycle rate of DN6 was activated and amino acid metabolism was inhibited. In TS, the TCA cycle rate of DN3 was inhibited, and amino acid metabolism was not significantly changed, while the TCA cycle rate of DN6 was activated and amino acid metabolism was inhibited. These results suggested that the response mechanisms of the two different rice strains to spaceflight stress are different, and these differences may be reflected in energy consumption and compound biosynthesis of rice in different growth and development stages. This study provided new insights for further exploring the effects of spaceflight.

Eleutheroside E Enhances the Long-Term Memory of Radiation-Damaged C. elegans through G-Protein-Coupled Receptor and Neuropeptide Signaling Pathways.

Eleutheroside E (EE), a principal active compound of Acanthopanax senticosus, has been shown to have a certain neuromodulation effect. Our previous study indicates that EE protects nerve damage caused by radiation. However, its specific function and underlying mechanism remain unknown. Therefore, the objective of this study is to apply the C. elegans model to illuminate the property and mechanism of EE protecting against nerve damage caused by radiation. Here, we found that EE significantly improved the long-term memory of radiation-damaged C. elegans. Through transcriptome sequencing, the results showed that EE protected radiation-damaged C. elegans mainly through G-protein-coupled receptor and neuropeptide signaling pathways. Further research indicated that EE affected the activity of CREB by cAMP-PKA, Gqα-PLC, and neuropeptide signaling pathways to ultimately improve the long-term memory of radiation-damaged C. elegans. In addition, the activity of Gqα and neuropeptides in AWC neurons and the activity of CREB in AIM neurons might be crucial for EE to function.

Proteomic analysis in different development stages on SP0 generation of rice seeds after space flight.

The space biological effects of plants will drive the development of aerospace science and breeding science. The aim of this study is to reveal changes in the proteome of contemporary plants at different growth and development stages after space flight of rice seeds. We carried the rice seeds (DN416) through the SJ-10 returning satellite and returned to the ground for planting to the three-leaf stage (TLP) and tillering stage (TS) after a 12.5-day orbital flight. We found that the space flight caused the rice germination rate, the TLP plant height, and the number of tillers in the TS decreased by 11.64%, 9.75%, and 9.80%, respectively. In addition, the treatment group ROS and MDA level increased in the TLP and TS. The abundance patterns of proteins in these leaves identified 214 proteins in the TLP and 286 in the TS leaves that were markedly changed. Moreover, our study identified D14 proteins that control plant height and tiller. Our results show that the space environment may affect the downstream signaling mechanism by regulating the level of ROS in the body to achieve a response to the space environment. Meanwhile, the space environment may affect the plant height and tiller of rice by altering the expression of D14 protein and hormone-regulated proteins. Our results reveal changes in the proteome of different growth stages of rice plants, and also reveal the molecular mechanism of space environment regulation of rice plant height and tiller, which provides a new direction for further understanding of space biological effects and space mutation breeding.

Simulated spatial radiation impacts learning and memory ability with alterations of neuromorphology and gut microbiota in mice.

Complex space environments, including microgravity and radiation, affect the body's central nervous system, endocrine system, circulatory system, and reproductive system. Radiation-induced aberration in the neuronal integrity and cognitive functions are particularly well known. Moreover, ionizing radiation is a likely contributor to alterations in the microbiome. However, there is a lacuna between radiation-induced memory impairment and gut microbiota. The present study was aimed at investigating the effects of simulated space-type radiation on learning and memory ability and gut microbiota in mice. Adult mice were irradiated by 60Co-γ rays at 4 Gy to simulate spatial radiation; behavioral experiments, pathological experiments, and transmission electron microscopy all showed that radiation impaired learning and memory ability and hippocampal neurons in mice, which was similar to the cognitive impairment in neurodegenerative diseases. In addition, we observed that radiation destroyed the colonic structure of mice, decreased the expression of tight junction proteins, and increased inflammation levels, which might lead to dysregulation of the intestinal microbiota. We found a correlation between the brain and colon in the changes in neurotransmitters associated with learning and memory. The 16S rRNA results showed that the bacteria associated with these neurotransmitters were also changed at the genus level and were significantly correlated. These results indicate that radiation-induced memory and cognitive impairment can be linked to gut microbiota through neurotransmitters.

Protective effects of Ulva pertusa polysaccharide and polysaccharide­iron (III) complex on cyclophosphamide induced immunosuppression in mice.

A water-soluble polysaccharide was isolated from marine green algae Ulva pertusa and then chelated with iron to prepare the polysaccharide­iron (III) complex. The immunomodulatory activities of sulfated polysaccharide and polysaccharide­iron (III) complex were investigated through a mice immune-deficiency model. Cyclophosphamide (Cy) was utilized to establish mice immunodeficiency model. Both polysaccharide and polysaccharide­iron (III) complex were proved to promote the proliferation of lymphocyte and enhance the activities of mice macrophages. In mice serum, the levels of cytokines including TNF-α, IFN-γ and IL-10 restored and the contents of hemolysin were also found elevated after treatment with polysaccharide and its iron complex. Besides, it has been shown that both polysaccharide and polysaccharide­iron (III) complex increased the contents of Hb, RBC and HCT in mice blood, and the effect of iron complex was better. All these results suggested that Ulva pertusa polysaccharide could be developed as a healthy function food. It was also noteworthy that the polysaccharide­iron (III) complex showed no negative effect upon the immunomodulatory activity of polysaccharide. Instead, the polysaccharide­iron (III) complex showed excellent hematopoietic capacity perhaps due to the supplement of iron.

Photosynthetic Performance of Rice Seedlings Originated from Seeds Exposed to Spaceflight Conditions.

The mechanism of the regulation on photosynthesis after spaceflight has not been fully understood. To learn more information about this, we conducted a series of experiments of photosystem, including photosynthetic physiological characteristics (fluorescence parameters, pigment contents), gene expression and proteomic change. We want to examine the response of rice (Oryza sativaDN416), whose seeds were placed in Bio-Radiation Box on the ShiJian-10(SJ-10) recoverable satellite. Our results demonstrated that the photosynthesis capacity of plants after spaceflight declined, compared to ground control plants. Specifically, Fv/Fm is significantly reduced for 7.5%. Chlorophyll content decreased in the three growth stages of rice, trefoil, tillering and mature stages. To further analyze changes under spaceflight environment, quantitative real-time PCR technology and isobaric tags for relative and absolute quantization (iTRAQ) labeling technology were deployed. We found that the gene expression of important subunits of key enzymes and important structures had been decreased after spaceflight. As for the results of changes in proteins, we discovered that the content of proteins related to electron transport and photosynthesis key enzyme declined. Our experiments can provide reference for further research to learn more about the effects of spaceflight on photosynthesis.