Analysis of nearly 3000 archaeal genomes from terrestrial geothermal springs sheds light on interconnected biogeochemical processes.

Terrestrial geothermal springs are physicochemically diverse and host abundant populations of Archaea. However, the diversity, functionality, and geological influences of these Archaea are not well understood. Here we explore the genomic diversity of Archaea in 152 metagenomes from 48 geothermal springs in Tengchong, China, collected from 2016 to 2021. Our dataset is comprised of 2949 archaeal metagenome-assembled genomes spanning 12 phyla and 392 newly identified species, which increases the known species diversity of Archaea by ~48.6%. The structures and potential functions of the archaeal communities are strongly influenced by temperature and pH, with high-temperature acidic and alkaline springs favoring archaeal abundance over Bacteria. Genome-resolved metagenomics and metatranscriptomics provide insights into the potential ecological niches of these Archaea and their potential roles in carbon, sulfur, nitrogen, and hydrogen metabolism. Furthermore, our findings illustrate the interplay of competition and cooperation among Archaea in biogeochemical cycles, possibly arising from overlapping functional niches and metabolic handoffs. Taken together, our study expands the genomic diversity of Archaea inhabiting geothermal springs and provides a foundation for more incisive study of biogeochemical processes mediated by Archaea in geothermal ecosystems.

Nernst and seebeck effects inα-T3lattice.

By using the tight-binding Hamiltonian and non-equilibrium Green's function methods, the Seebeck and Nernst effects ofα-T3lattice are investigated, in which the lattice interpolates between graphene and the dice lattice via the parameterα. Forα= 0 (graphene), flat bands are always present in the band structure. The Seebeck and Nernst coefficients are consistent with those in graphene. Whenαis non-zero at zero magnetic field, the Seebeck coefficient is an odd function of the Fermi energy. It produces a very large and wide first peak within the band gap for the zigzag boundary. Under the influence of magnetic fields, the first peak of the Seebeck coefficient in the gap region increases withαincreasing. The Nernst effect occurs under the influence of a magnetic field. The height of the zeroth peak of the Nernst coefficient increases withαincreasing. Whenαreaches a certain value, the zeroth peak splits. The post-split peak decreases withαincreasing for the zigzag boundary, but continues to become wider and higher for the armchair boundary.

CD39 expression defines exhausted CD4+ T cells associated with poor survival and immune evasion in human gastric cancer.

Objectives: CD4+ T cell helper and regulatory function in human cancers has been well characterised. However, the definition of tumor-infiltrating CD4+ T cell exhaustion and how it contributes to the immune response and disease progression in human gastric cancer (GC) remain largely unknown. Methods: A total of 128 GC patients were enrolled in the study. The expression of CD39 and PD-1 on CD4+ T cells in the different samples was analysed by flow cytometry. GC-infiltrating CD4+ T cell subpopulations based on CD39 expression were phenotypically and functionally assessed. The role of CD39 in the immune response of GC-infiltrating T cells was investigated by inhibiting CD39 enzymatic activity. Results: In comparison with CD4+ T cells from the non-tumor tissues, significantly more GC-infiltrating CD4+ T cells expressed CD39. Most GC-infiltrating CD39+CD4+ T cells exhibited CD45RA-CCR7- effector-memory phenotype expressing more exhaustion-associated inhibitory molecules and transcription factors and produced less TNF-α, IFN-γ and cytolytic molecules than their CD39-CD4+ counterparts. Moreover, ex vivo inhibition of CD39 enzymatic activity enhanced their functional potential reflected by TNF-α and IFN-γ production. Finally, increased percentages of GC-infiltrating CD39+CD4+ T cells were positively associated with disease progression and patients' poorer overall survival. Conclusion: Our study demonstrates that CD39 expression defines GC-infiltrating CD4+ T cell exhaustion and their immunosuppressive function. Targeting CD39 may be a promising therapeutic strategy for treating GC patients.

CD39hi identifies an exhausted tumor-reactive CD8+ T cell population associated with tumor progression in human gastric cancer.

The ectonucleotidase CD39 has been regarded as a promising immune checkpoint in solid tumors. However, the expression of CD39 by tumor-infiltrating CD8+ T cells as well as their potential roles and clinical implications in human gastric cancer (GC) remain largely unknown. Here, we found that GC-infiltrating CD8+ T cells contained a fraction of CD39hi cells that constituted about 6.6% of total CD8+ T cells in tumors. These CD39hi cells enriched for GC-infiltrating CD8+ T cells with features of exhaustion in transcriptional, phenotypic, metabolic and functional profiles. Additionally, GC-infiltrating CD39hiCD8+ T cells were also identified for tumor-reactive T cells, as these cells expanded in vitro were able to recognize autologous tumor organoids and induced more tumor cell apoptosis than those of expanded their CD39int and CD39-CD8+ counterparts. Furthermore, CD39 enzymatic activity controlled GC-infiltrating CD39hiCD8+ T cell effector function, and blockade of CD39 efficiently enhanced their production of cytokines IFN-γ and TNF-α. Finally, high percentages of GC-infiltrating CD39hiCD8+ T cells correlated with tumor progression and independently predicted patients' poor overall survival. These findings provide novel insights into the association of CD39 expression level on CD8+ T cells with their features and potential clinical implications in GC, and empowering those exhausted tumor-reactive CD39hiCD8+ T cells through CD39 inhibition to circumvent the suppressor program may be an attractive therapeutic strategy against GC.

Temperature, pH, and oxygen availability contributed to the functional differentiation of ancient Nitrososphaeria.

Ammonia-oxidizing Nitrososphaeria are among the most abundant archaea on Earth and have profound impacts on the biogeochemical cycles of carbon and nitrogen. In contrast to these well-studied ammonia-oxidizing archaea (AOA), deep-branching non-AOA within this class remain poorly characterized because of a low number of genome representatives. Here, we reconstructed 128 Nitrososphaeria metagenome-assembled genomes from acid mine drainage and hot spring sediment metagenomes. Comparative genomics revealed that extant non-AOA are functionally diverse, with capacity for carbon fixation, carbon monoxide oxidation, methanogenesis, and respiratory pathways including oxygen, nitrate, sulfur, or sulfate, as potential terminal electron acceptors. Despite their diverse anaerobic pathways, evolutionary history inference suggested that the common ancestor of Nitrososphaeria was likely an aerobic thermophile. We further surmise that the functional differentiation of Nitrososphaeria was primarily shaped by oxygen, pH, and temperature, with the acquisition of pathways for carbon, nitrogen, and sulfur metabolism. Our study provides a more holistic and less biased understanding of the diversity, ecology, and deep evolution of the globally abundant Nitrososphaeria.

LncRNA CASC11 upregulation promotes HDAC4 to alleviate oxidized low-density lipoprotein-induced injury of cardiac microvascular endothelial cells.

Long noncoding RNAs (LncRNAs) are essential to regulate the pathogenesis of coronary artery disease (CAD). This study was conducted to analyze the functionality of long noncoding RNA cancer susceptibility candidate 11 (lncRNA CASC11) in oxidized low-density lipoprotein (ox-LDL)-induced injury of cardiac microvascular endothelial cells (CMECs). CMECs were treated with ox-LDL to induce the CAD cell model. The cellular expression levels of CASC11 and histone deacetylase 4 (HDAC4) were determined by real-time quantitative polymerase chain reaction or Western blot assay. Cell absorbance, apoptosis, angiogenesis, and inflammation were evaluated by cell counting kit-8, flow cytometry, tube formation, and enzyme-linked immunosorbent assays. The subcellular localization of CASC11 was examined by the nuclear/cytoplasmic fractionation assay. The binding of human antigen R (HuR) to CASC11 and HDAC4 was analyzed by RNA immunoprecipitation. HDAC4 stability was determined after actinomycin D treatment. CASC11 was found to be decreased in the CAD cell model. CASC11 upregulation increased cell viability and angiogenesis and reduced apoptosis and inflammation. CASC11 bound to HuR and improved HDAC4 expression. HDAC4 downregulation counteracted the protective role of CASC11 overexpression in CMECs. In summary, CASC11 alleviated ox-LDL-induced injury of CMECs by binding to HuR and stabilizing HDAC4.

Metagenomic Discovery of "Candidatus Parvarchaeales"-Related Lineages Sheds Light on Adaptation and Diversification from Neutral-Thermal to Acidic-Mesothermal Environments.

"Candidatus Parvarchaeales" microbes, representing a DPANN archaeal group with limited metabolic potential and reliance on hosts for their growth, were initially found in acid mine drainage (AMD). Due to the lack of representatives, however, their ecological roles and adaptation to extreme habitats such as AMD as well as how they diverge across the lineage remain largely unexplored. By applying genome-resolved metagenomics, 28 Parvarchaeales-associated metagenome-assembled genomes (MAGs) representing two orders and five genera were recovered. Among them, we identified three new genera and proposed the names "Candidatus Jingweiarchaeum," "Candidatus Haiyanarchaeum," and "Candidatus Rehaiarchaeum," with the former two belonging to a new order, "Candidatus Jingweiarchaeales." Further analyses of the metabolic potentials revealed substantial niche differentiation between Jingweiarchaeales and Parvarchaeales. Jingweiarchaeales may rely on fermentation, salvage pathways, partial glycolysis, and the pentose phosphate pathway (PPP) for energy conservation reservation, while the metabolic potentials of Parvarchaeales might be more versatile. Comparative genomic analyses suggested that Jingweiarchaeales favor habitats with higher temperatures and that Parvarchaeales are better adapted to acidic environments. We further revealed that the thermal adaptation of these lineages, especially Haiyanarchaeum, might rely on genomic features such as the usage of specific amino acids, genome streamlining, and hyperthermophile featured genes such as rgy. Notably, the adaptation of Parvarchaeales to acidic environments was possibly driven by horizontal gene transfer (HGT). The reconstruction of ancestral states demonstrated that both may have originated from thermal and neutral environments and later spread to mesothermal and acidic environments. These evolutionary processes may also be accompanied by adaptation to oxygen-rich environments via HGT. IMPORTANCE "Candidatus Parvarchaeales" microbes may represent a lineage uniquely distributed in extreme environments such as AMD and hot springs. However, little is known about the strategies and processes of how they adapted to these extreme environments. By the discovery of potential new order-level lineages, "Ca. Jingweiarchaeales," and in-depth comparative genomic analysis, we unveiled the functional differentiation of these lineages. Furthermore, we show that the adaptation of these lineages to high-temperature and acidic environments was driven by different strategies, with the former relying more on genomic characteristics such as genome streamlining and amino acid compositions and the latter relying more on the acquisition of genes associated with acid tolerance. Finally, by the reconstruction of the ancestral states of the optimal growth temperature (OGT) and isoelectric point (pI), we showed the potential evolutionary process of Parvarchaeales-related lineages with regard to the shift from the high-temperature environment of their common ancestors to low-temperature (potentially acidic) environments.

Panguiarchaeum symbiosum, a potential hyperthermophilic symbiont in the TACK superphylum.

The biology of Korarchaeia remains elusive due to the lack of genome representatives. Here, we reconstruct 10 closely related metagenome-assembled genomes from hot spring habitats and place them into a single species, proposed herein as Panguiarchaeum symbiosum. Functional investigation suggests that Panguiarchaeum symbiosum is strictly anaerobic and grows exclusively in thermal habitats by fermenting peptides coupled with sulfide and hydrogen production to dispose of electrons. Due to its inability to biosynthesize archaeal membranes, amino acids, and purines, this species likely exists in a symbiotic lifestyle similar to DPANN archaea. Population metagenomics and metatranscriptomic analyses demonstrated that genes associated with amino acid/peptide uptake and cell attachment exhibited positive selection and were highly expressed, supporting the proposed proteolytic catabolism and symbiotic lifestyle. Our study sheds light on the metabolism, evolution, and potential symbiotic lifestyle of Panguiarchaeum symbiosum, which may be a unique host-dependent archaeon within the TACK superphylum.

Functional differentiation determines the molecular basis of the symbiotic lifestyle of Ca. Nanohaloarchaeota.

BACKGROUND: Candidatus Nanohaloarchaeota, an archaeal phylum within the DPANN superphylum, is characterized by limited metabolic capabilities and limited phylogenetic diversity and until recently has been considered to exclusively inhabit hypersaline environments due to an obligate association with Halobacteria. Aside from hypersaline environments, Ca. Nanohaloarchaeota can also have been discovered from deep-subsurface marine sediments. RESULTS: Three metagenome-assembled genomes (MAGs) representing a new order within the Ca. Nanohaloarchaeota were reconstructed from a stratified salt crust and proposed to represent a novel order, Nucleotidisoterales. Genomic features reveal them to be anaerobes capable of catabolizing nucleotides by coupling nucleotide salvage pathways with lower glycolysis to yield free energy. Comparative genomics demonstrated that these and other Ca. Nanohaloarchaeota inhabiting saline habitats use a "salt-in" strategy to maintain osmotic pressure based on the high proportion of acidic amino acids. In contrast, previously described Ca. Nanohaloarchaeota MAGs from geothermal environments were enriched with basic amino acids to counter heat stress. Evolutionary history reconstruction revealed that functional differentiation of energy conservation strategies drove diversification within Ca. Nanohaloarchaeota, further leading to shifts in the catabolic strategy from nucleotide degradation within deeper lineages to polysaccharide degradation within shallow lineages. CONCLUSIONS: This study provides deeper insight into the ecological functions and evolution of the expanded phylum Ca. Nanohaloarchaeota and further advances our understanding on the functional and genetic associations between potential symbionts and hosts. Video Abstract.

Distribution, phenotype, functional and clinical relevance of CD8+CD103+ tissue-resident memory T cells in human gastric cancer.

CD8+CD103+ tissue-resident memory T cells (TRMs) are involved in tumor immune response and linked to favorable clinical outcome in human cancer. However, the distribution, phenotype, functional properties and clinical relevance of these cells in gastric cancer (GC) remain elusive. Here, our data show that, in comparison to non-tumor tissues, the percentages of CD8+CD103+ TRMs in tumors are significantly decreased. Most tumor-infiltrating CD8+CD103+ TRMs are CD45RA-CCR7- effector-memory cells with higher PD-1 and 4-1BB expression than those from non-tumor tissues. Further, tumor-infiltrating CD8+CD103+ TRMs show impaired cytolytic capacity due to decreased granzyme B and perforin expression. Moreover, ex vivo PD-1 blockade could restore the cytolytic capacity of tumor-infiltrating CD8+CD103+ TRMs, and such anti-PD-1-mediated reinvigoration of CD8+CD103+ TRMs could be further enhanced by 4-1BB co-stimulation. Finally, lower levels of Tumor-infiltrating CD8+CD103+ TRMs are positively correlated with GC progression and poor patients' survival. Our data suggest that restoring CD8+CD103+ TRM function by combining PD-1 blockade and 4-1BB co-stimulation may be a promising strategy for treating GC.

Black Bamboo Rhizome Extract Improves Cognitive Dysfunction by Upregulating the Expression of Hippocampal BDNF and CREB in Rats with Cerebral Ischaemia-Reperfusion Injury.

INTRODUCTION: The study aimed to explore the effects of treatment with black bamboo rhizome extracts on learning and memory and determine the underlying mechanisms in rats with cerebral ischaemia-reperfusion injury. METHODS: Sprague-Dawley rats were randomly divided into the following four groups: control, middle cerebral artery occlusion (MCAO), low-dose drug, and high-dose drug groups. Rats underwent MCAO using a suture method before drug treatment. Then, neurological impairment was assessed using the Longa scoring method, and triphenyl tetrazolium chloride staining was used to analyse the cerebral infarction area. The Elliott formula was used to calculate water content in the brain tissue. A Morris water maze (MWM) was used to assess changes in learning and memory abilities, and Western blotting was used to detect cyclic adenosine phosphate response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) expression in the hippocampus of MCAO rats. RESULTS: After treatment with black bamboo rhizome extracts, the neurological dysfunction score was lower in the drug groups than in the MCAO group, and a significant difference was observed between the high-dose drug and MCAO groups (P<0.05). Additionally, the cerebral infarction area was significantly smaller in the drug groups than in the MCAO group (P<0.01), and the effect was more obvious in the high-dose drug group than in the low-dose drug group. There was also a significant difference in water content between the high-dose drug and MCAO groups, and cerebral oedema was significantly reduced in the high-dose drug group (P<0.05). In the MWM, the incubation period was significantly reduced, the number of platform crossings was significantly increased, and the search time was prolonged in the drug groups compared with those in the MCAO group (P<0.05). Moreover, the expression of BDNF and CREB was significantly increased in the drug groups compared to that in the MCAO group, and the increase was more obvious in the high-dose group than in the low-dose group (P<0.05). DISCUSSION: Black bamboo rhizome extracts significantly improved cognitive dysfunction, reduced cerebral oedema, decreased the cerebral infarction area, and improved the neurological function score and learning and memory abilities in rats with cerebral ischaemia-reperfusion injury.

Deciphering Symbiotic Interactions of "Candidatus Aenigmarchaeota" with Inferred Horizontal Gene Transfers and Co-occurrence Networks.

"Candidatus Aenigmarchaeota" ("Ca. Aenigmarchaeota") represents one of the earliest proposed evolutionary branches within the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota (DPANN) superphylum. However, their ecological roles and potential host-symbiont interactions are still poorly understood. Here, eight metagenome-assembled genomes (MAGs) were reconstructed from hot spring ecosystems, and further in-depth comparative and evolutionary genomic analyses were conducted on these MAGs and other genomes downloaded from public databases. Although with limited metabolic capacities, we reported that "Ca. Aenigmarchaeota" in thermal environments harbor more genes related to carbohydrate metabolism than "Ca. Aenigmarchaeota" in nonthermal environments. Evolutionary analyses suggested that members from the Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota (TACK) superphylum and Euryarchaeota contribute substantially to the niche expansion of "Ca. Aenigmarchaeota" via horizontal gene transfer (HGT), especially genes related to virus defense and stress responses. Based on co-occurrence network results and recent genetic exchanges among community members, we conjectured that "Ca. Aenigmarchaeota" may be symbionts associated with one MAG affiliated with the genus Pyrobaculum, though host specificity might be wide and variable across different "Ca. Aenigmarchaeota" organisms. This study provides significant insight into possible DPANN-host interactions and ecological roles of "Ca. Aenigmarchaeota." IMPORTANCE Recent advances in sequencing technology promoted the blowout discovery of super tiny microbes in the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, and Nanohaloarchaeota (DPANN) superphylum. However, the unculturable properties of the majority of microbes impeded our investigation of their behavior and symbiotic lifestyle in the corresponding community. By integrating horizontal gene transfer (HGT) detection and co-occurrence network analysis on "Candidatus Aenigmarchaeota" ("Ca. Aenigmarchaeota"), we made one of the first attempts to infer their putative interaction partners and further decipher the potential functional and genetic interactions between the symbionts. We revealed that HGTs contributed by members from the Thaumarchaeota, Aigarchaeota, Crenarchaeota, and Korarchaeota (TACK) superphylum and Euryarchaeota conferred "Ca. Aenigmarchaeota" with the ability to survive under different environmental stresses, such as virus infection, high temperature, and oxidative stress. This study demonstrates that the interaction partners might be inferable by applying informatics analyses on metagenomic sequencing data.

Comparative Genomics Reveals Thermal Adaptation and a High Metabolic Diversity in "Candidatus Bathyarchaeia".

"Candidatus Bathyarchaeia" is a phylogenetically diverse and widely distributed lineage often in high abundance in anoxic submarine sediments; however, their evolution and ecological roles in terrestrial geothermal habitats are poorly understood. In the present study, 35 Ca. Bathyarchaeia metagenome-assembled genomes (MAGs) were recovered from hot spring sediments in Tibet and Yunnan, China. Phylogenetic analysis revealed all MAGs of Ca. Bathyarchaeia can be classified into 7 orders and 15 families. Among them, 4 families have been first discovered in the present study, significantly expanding the known diversity of Ca. Bathyarchaeia. Comparative genomics demonstrated Ca. Bathyarchaeia MAGs from thermal habitats to encode a large variety of genes related to carbohydrate degradation, which are likely a metabolic adaptation of these organisms to a lifestyle at high temperatures. At least two families are potential methanogens/alkanotrophs, indicating a potential for the catalysis of short-chain hydrocarbons. Three MAGs from Family-7.3 are identified as alkanotrophs due to the detection of an Mcr complex. Family-2 contains the largest number of genes relevant to alkyl-CoM transformation, indicating the potential for methylotrophic methanogenesis, although their evolutionary history suggests the ancestor of Ca. Bathyarchaeia was unable to metabolize alkanes. Subsequent lineages have acquired the ability via horizontal gene transfer. Overall, our study significantly expands our knowledge and understanding of the metabolic capabilities, habitat adaptations, and evolution of Ca. Bathyarchaeia in thermal environments. IMPORTANCE Ca. Bathyarchaeia MAGs from terrestrial hot spring habitats are poorly revealed, though they have been studied extensively in marine ecosystems. In this study, we uncovered the metabolic capabilities and ecological role of Ca. Bathyarchaeia in hot springs and give a comprehensive comparative analysis between thermal and nonthermal habitats to reveal the thermal adaptability of Ca. Bathyarchaeia. Also, we attempt to determine the evolutionary history of methane/alkane metabolism in Ca. Bathyarchaeia, since it appears to be the first archaea beyond Euryarchaeota which contains the mcrABG genes. The reclassification of Ca. Bathyarchaeia and significant genomic differences among different lineages largely expand our knowledge on these cosmopolitan archaea, which will be beneficial in guiding the future studies.

Preferential gene retention increases the robustness of cold regulation in Brassicaceae and other plants after polyploidization.

Cold stress profoundly affects plant growth and development and is a key factor affecting the geographic distribution and evolution of plants. Plants have evolved adaptive mechanisms to cope with cold stress. Here, through the genomic analysis of Arabidopsis, three Brassica species and 17 other representative species, we found that both cold-related genes (CRGs) and their collinearity were preferentially retained after polyploidization followed by genome instability, while genome-wide gene sets exhibited a variety of other expansion mechanisms. The cold-related regulatory network was increased in Brassicaceae genomes, which were recursively affected by polyploidization. By combining our findings regarding the selective retention of CRGs from this ecological genomics study with the available knowledge of cold-induced chromosome doubling, we hypothesize that cold stress may have contributed to the success of polyploid plants through both increasing polyploidization and selectively maintaining CRGs during evolution. This hypothesis requires further biological and ecological exploration to obtain solid supporting evidence, which will potentially contribute to understanding the generation of polyploids and to the field of ecological genomics.

Insights into the ecological roles and evolution of methyl-coenzyme M reductase-containing hot spring Archaea.

Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor.

Two Likely Auto-Tetraploidization Events Shaped Kiwifruit Genome and Contributed to Establishment of the Actinidiaceae Family.

The genome of kiwifruit (Actinidia chinensis) was sequenced previously, the first in the Actinidiaceae family. It was shown to have been affected by polyploidization events, the nature of which has been elusive. Here, we performed a reanalysis of the genome and found clear evidence of 2 tetraploidization events, with one occurring ∼50-57 million years ago (Mya) and the other ∼18-20 Mya. Two subgenomes produced by each event have been under balanced fractionation. Moreover, genes were revealed to express in a balanced way between duplicated copies of chromosomes. Besides, lowered evolutionary rates of kiwifruit genes were observed. These findings could be explained by the likely auto-tetraploidization nature of the polyploidization events. Besides, we found that polyploidy contributed to the expansion of key functional genes, e.g., vitamin C biosynthesis genes. The present work also provided an important comparative genomics resource in the Actinidiaceae and related families.

Genomic inference of the metabolism and evolution of the archaeal phylum Aigarchaeota.

Microbes of the phylum Aigarchaeota are widely distributed in geothermal environments, but their physiological and ecological roles are poorly understood. Here we analyze six Aigarchaeota metagenomic bins from two circumneutral hot springs in Tengchong, China, to reveal that they are either strict or facultative anaerobes, and most are chemolithotrophs that can perform sulfide oxidation. Applying comparative genomics to the Thaumarchaeota and Aigarchaeota, we find that they both originated from thermal habitats, sharing 1154 genes with their common ancestor. Horizontal gene transfer played a crucial role in shaping genetic diversity of Aigarchaeota and led to functional partitioning and ecological divergence among sympatric microbes, as several key functional innovations were endowed by Bacteria, including dissimilatory sulfite reduction and possibly carbon monoxide oxidation. Our study expands our knowledge of the possible ecological roles of the Aigarchaeota and clarifies their evolutionary relationship to their sister lineage Thaumarchaeota.

Antifatigue Effects of Ethanol Extracts and Polysaccharides Isolated from Abelmoschus esculentus.

BACKGROUND: The aim of this study is to determine the antifatigue active fraction from Abelmoschus esculentus. The in vivo antifatigue effects of ethanol extracts and polysaccharides from A. esculentus fruit have been determined. The polysaccharides of A. esculentus were determined as the best effective fractions of antifatigue effects. MATERIALS AND METHODS: About 360 Kunming male mice were randomly divided into nine subgroups: normal control subgroup, model subgroup, positive subgroup and the ethanol extracts of A. esculentus with high dose (3.2 g/kg) subgroup, medium dose (1.6 g/kg) subgroup and low dose (0.8 g/kg) subgroup, the polysaccharides of high dose (3.2 g/kg) subgroup, medium dose (1.6 g/kg) subgroup, and the low dose (0.8 g/kg) subgroup. The antifatigue effects of ethanol extracts and polysaccharides form A. esculentus were measured by comparing body weight, food intake, swimming time, liver glycogen, serum urea, blood lactic acid as well as visceral parameter in mice. RESULTS: Compared with the model subgroup, other subgroups significantly prolonged swimming time, and high dose polysaccharides administration was the most effective (P < 0.01). High dose polysaccharides significantly increased liver glycogen, serum lactic acid, and serum urea (P < 0.01) in mice. In contrast with model group, the high dose polysaccharides administration could also significantly elevated the parameters of testicles and epididymis (P < 0.01). The study established that the ethanol extracts and polysaccharides of A. esculentus both have antifatigue effects. CONCLUSIONS: The results demonstrated that both the ethanol extracts and polysaccharides of A. esculentus have antifatigue effects. The high dosage polysaccharides have significant antifatigue properties. The results will provide the basis for further development and utilization of this plant. SUMMARY: The high dosage polysaccharides have restoration ability on kidney yang deficiency mice.The high dosage polysaccharides have significant effects of relieving body fatigue of mice.The polysaccharide of Abelmoschus esculentus showed better antifatigue effects than the ethanol extracts. Abbreviations used: A. esculentus: Abelmoschus esculentus, BUN: Blood urine nitrogen, LD: Lactic Acid dehydrogenase, AE: Abelmoschus esculentus ethanol extracts, AP: Abelmoschus esculentus polysaccharides, LAC: Lactic acid content.

A new anti-hypoxia sesquiterpene from the rhizome of Petasites japonicas.

A new sesquiterpene, bakkenolide-Ⅵa (1), was isolated from the rhizome of Petasites japonicas (Sieb. et Zucc.) Maxim. The structure was characterized on the basis of various NMR ((1)H, (13)C, (1)H-(1)H COSY, HMQC, HMBC and NOESY) and mass spectrometry data. Bakkenolide-Ⅵa showed potent cerebral hypoxia- ischemia protective activity in mice subjected to decapitation through prolonging the survival time and gasping time. It also exhibited a protective activity against hypoxia injury in PC12 cells in anaerobic culture by inhibition of lactate dehydrogenase (LDH) release.

[Comparative study of high altitude chronic hypoxia on renal function in yak and migrated cattle on Qinghai-Tibetan plateau].

OBJECTIVE: To investigate the difference of renal function among yak, migrated cattle on Qinghai-tibetan plateau and lowland cattle, and to further explore the characteristics of renal to adapt chronic hypoxia. METHODS: The serum samples of yak(n=84) were collected at 3 000 m,3 500 m,4 000 m and 4 300 m respectively,meanwhile the serum samples of migrated cattle on plateau (n=22) and lowland cattle (n=39) were also collected.The levels of blood urea nitrogen(BUN), creatinine(Crea), blood urea nitrogen/creatinine(BUN/Cr), uric acid(UA), carbon dioxide binding rate(CO2cp), glucose(GLU) in serum were measured by using fully automatic blood biochemical analyzer. We analysed the differences among the above renal functions. RESULTS: With the altitudeincreased, the results showed the levels of UA and CO2cp of yak were increased significantly, as compared to cattle, the levels of BUN and BUN/Cr were increased significantly compared with migrated cattle on plateau and lowland cattle, thelevels of CO2cp and GLU were decreased significantly compared with lowland cattle. As compared to migrated cattle on plateau, the levels of BUN and BUN/Cr of lowland cattle were decreased significantly, the levels of UA and CO2cp were increased significantly. CONCLUSIONS: The results indicated that theyak were adaptedto the plateau hypoxia environment and migrated cattle maybe not adapt to the low oxygen environment, they were under the stress situation.