Antimicrobial peptide cecropin B functions in pathogen resistance of Mythimna separata.

Mythimna separata (Lepidoptera: Noctuidae) is an omnivorous pest that poses a great threat to food security. Insect antimicrobial peptides (AMPs) are small peptides that are important effector molecules of innate immunity. Here, we investigated the role of the AMP cecropin B in the growth, development, and immunity of M. separata. The gene encoding M. separata cecropin B (MscecropinB) was cloned. The expression of MscecropinB was determined in different developmental stages and tissues of M. separata. It was highest in the prepupal stage, followed by the pupal stage. Among larval stages, the highest expression was observed in the fourth instar. Tissue expression analysis of fourth instar larvae showed that MscecropinB was highly expressed in the fat body and haemolymph. An increase in population density led to upregulation of MscecropinB expression. MscecropinB expression was also upregulated by the infection of third and fourth instar M. separata with Beauveria bassiana or Bacillus thuringiensis (Bt). RNA interference (RNAi) targeting MscecropinB inhibited the emergence rate and fecundity of M. separata, and resulted in an increased sensitivity to B. bassiana and Bt. The mortality of M. separata larvae was significantly higher in pathogen plus RNAi-treated M. separata than in controls treated with pathogens only. Our findings indicate that MscecropinB functions in the eclosion and fecundity of M. separata and plays an important role in resistance to infection by B. bassiana and Bt.

Palmitoylation of hIFITM1 inhibits JEV infection and contributes to BBB stabilization.

Human brain microvascular endothelial cells (hBMECs) are the main component cells of the blood-brain barrier (BBB) and play a crucial role in responding to viral infections to prevent the central nervous system (CNS) from viral invasion. Interferon-inducible transmembrane protein 1 (IFITM1) is a multifunctional membrane protein downstream of type-I interferon. In this study, we discovered that hIFITM1 expression was highly upregulated in hBMECs during Japanese encephalitis virus (JEV) infection. Depletion of hIFITM1 with CRISPR/Cas9 in hBMECs enhanced JEV replication, while overexpression of hIFITM1 restricted the viruses. Additionally, overexpression of hIFITM1 promoted the monolayer formation of hBMECs with a better integrity and a higher transendothelial electrical resistance (TEER), and reduced the penetration of JEV across the BBB. However, the function of hIFITM1 is governed by palmitoylation. Mutations of palmitoylation residues in conserved CD225 domain of hIFITM1 impaired its antiviral capacity. Moreover, mutants retained hIFITM1 in the cytoplasm and lessened its interaction with tight junction protein Occludin. Taken together, palmitoylation of hIFITM1 is essential for its antiviral activity in hBMECs, and more notably, for the maintenance of BBB homeostasis.

The TorRS two component system regulates expression of TMAO reductase in response to high hydrostatic pressure in Vibrio fluvialis.

High hydrostatic pressure (HHP) regulated gene expression is one of the most commonly adopted strategies for microbial adaptation to the deep-sea environments. Previously we showed that the HHP-inducible trimethylamine N-oxide (TMAO) reductase improves the pressure tolerance of deep-sea strain Vibrio fluvialis QY27. Here, we investigated the molecular mechanism of HHP-responsive regulation of TMAO reductase TorA. By constructing torR and torS deletion mutants, we demonstrated that the two-component regulator TorR and sensor TorS are responsible for the HHP-responsive regulation of torA. Unlike known HHP-responsive regulatory system, the abundance of torR and torS was not affected by HHP. Complementation of the ΔtorS mutant with TorS altered at conserved phosphorylation sites revealed that the three sites were indispensable for substrate-induced regulation, but only the histidine located in the alternative transmitter domain was involved in pressure-responsive regulation. Taken together, we demonstrated that the induction of TMAO reductase by HHP is mediated through the TorRS system and proposed a bifurcation of signal transduction in pressure-responsive regulation from the substrate-induction. This work provides novel knowledge of the pressure regulated gene expression and will promote the understanding of the microbial adaptation to the deep-sea HHP environment.

Tepidibacter hydrothermalis sp. nov., a novel anaerobic bacterium isolated from a deep-sea hydrothermal vent.

A novel anaerobic heterotrophic bacterium, designated strain SWIR-1T, was isolated from a deep-sea hydrothermal vent field sample collected from the Southwest Indian Ridge at a depth of 2700 m. Phylogenetic analysis indicated that strain SWIR-1T belongs to the genus Tepidibacter, and the most closely related species are Tepidibacter mesophilus B1T (99.1 % 16S rRNA gene sequence similarity), Tepidibacter formicigenes DV1184T (94.6 %) and Tepidibacter thalassicus SC562T (93.9 %). Strain SWIR-1T shares 77.3-87.2 % average nucleotide identity and 21.5-35.7 % digital DNA-DNA hybridization values with the three type strains of Tepidibacter species. Cells of strain SWIR-1T were Gram-stain-positive, motile, short straight rods. Endospores were observed in stationary-phase cells when grown on Thermococcales rich medium. Strain SWIR-1T grew at 15-45 °C (optimum, 30°C), at pH 5.5-8.0 (optimum, pH 7.0) and with 1.0-6.0 % (w/v) NaCl (optimum, 2.0 %). Substrates utilized by strain SWIR-1T included complex proteinaceous, chitin, starch, lactose, maltose, fructose, galactose, glucose, rhamnose, arabinose, ribose, alanine, glycine and glycerol. The major fermentation products from glucose were acetate, lactate, H2 and CO2. Elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate, nitrite and FeCl3 are not used as terminal electron acceptors. The main cellular fatty acids consisted of iso-C15 : 0 (28.4 %), C15 : 1 iso F (15.4 %) and C16 : 0 (9.8 %). The major polar lipids were phospholipids and glycolipids. No respiratory quinones were detected. Genomic comparison revealed a distinctive blended gene cluster comprising hyb-tat-hyp genes, which play a crucial role in the synthesis, maturation, activation and export of NiFe-hydrogenase. Based on the phylogenetic analysis, genomic, physiologic and chemotaxonomic characteristics, strain SWIR-1T is considered to represent a novel species within the genus Tepidibacter, for which the name Tepidibacter hydrothermalis sp. nov. is proposed. The type strain is strain SWIR-1T (=DSM 113848T=MCCC 1K07078T).

Parasedimentitalea psychrophila sp. nov., a psychrophilic bacterium isolated from deep-sea sediment.

A novel bacterium, strain QS115T, was isolated from deep-sea sediment collected from the South China Sea at a depth of 1151 m. Phylogenetic analyses based on 16S rRNA gene sequences indicated that QS115T was most closely related to Parasedimentitalea marina W43T, with similarity of 98.21 %. Strain QS115T shared 82.39 % average nucleotide identity, 26.3 % digital DNA-DNA hybridization and 85.32 % average amino acid identity with P. marina W43T. Cells of strain QS115T were Gram-stain-negative, rod-shaped and grew optimally at 10 °C, pH 7.5 and 2 % (w/v) NaCl. The principal fatty acids were summed feature 8 (C18 : 1 ω7c/ω6c), the major respiratory quinone was ubiquinone-10 and predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, glycophospholipid, phosphatidylglycerol and phosphatidylcholine. Polyphasic analyses of physiological and phenotypic characteristics and genomic studies suggested that strain QS115T represents a novel species of the genus Parasedimentitalea, for which the name Parasedimentitalea psychrophila sp. nov. is proposed (type strain QS115T=MCCC 1K04395T=JCM 34219T).

Genome analysis of Tepidibacter sp. SWIR-1, an anaerobic endospore-forming bacterium isolated from a deep-sea hydrothermal vent.

Tepidibacter sp. SWIR-1, a putative new species isolated from deep-sea hydrothermal vent field on the Southwest Indian Ridge (SWIR), is an anaerobic, mesophilic and endospore-forming bacterium belonging to the family Peptostreptococcaceae. In this study, we present the complete genome sequence of strain SWIR-1, consists of a single circular chromosome comprising 4,122,966 nucleotides with 29.25% G + C content and a circular plasmid comprising 38,843 nucleotides with 29.46% G + C content. In total, 3861 protein coding genes, 104 tRNA genes and 46 rRNA genes were obtained. SWIR-1 genome contains numerous genes related to sporulation and germination. Compared with the other three Tepidibacter species, SWIR-1 contained more spore germination receptor proteins. In addition, SWIR-1 contained more genes involved in chemotaxis and two-component systems than other Tepidibacter species. These results indicated that SWIR-1 has developed versatile adaptability to the Southwest Indian Ridge hydrothermal vent environment. The genome of strain SWIR-1 will be helpful for further understanding adaptive strategies used by bacteria dwelling in the deep-sea hydrothermal vent environments of different oceans.

Bioluminescence Contributes to the Adaptation of Deep-Sea Bacterium Photobacterium phosphoreum ANT-2200 to High Hydrostatic Pressure.

Bioluminescence is a common phenomenon in nature, especially in the deep ocean. The physiological role of bacterial bioluminescence involves protection against oxidative and UV stresses. Yet, it remains unclear if bioluminescence contributes to deep-sea bacterial adaptation to high hydrostatic pressure (HHP). In this study, we constructed a non-luminescent mutant of ΔluxA and its complementary strain c-ΔluxA of Photobacterium phosphoreum ANT-2200, a deep-sea piezophilic bioluminescent bacterium. The wild-type strain, mutant and complementary strain were compared from aspects of pressure tolerance, intracellular reactive oxygen species (ROS) level and expression of ROS-scavenging enzymes. The results showed that, despite similar growth profiles, HHP induced the accumulation of intracellular ROS and up-regulated the expression of ROS-scavenging enzymes such as dyp, katE and katG, specifically in the non-luminescent mutant. Collectively, our results suggested that bioluminescence functions as the primary antioxidant system in strain ANT-2200, in addition to the well-known ROS-scavenging enzymes. Bioluminescence contributes to bacterial adaptation to the deep-sea environment by coping with oxidative stress generated from HHP. These results further expanded our understanding of the physiological significance of bioluminescence as well as a novel strategy for microbial adaptation to a deep-sea environment.

Piezophilic Phenotype Is Growth Condition Dependent and Correlated with the Regulation of Two Sets of ATPase in Deep-Sea Piezophilic Bacterium Photobacterium profundum SS9.

Alteration of respiratory components as a function of pressure is a common strategy developed in deep-sea microorganisms, presumably to adapt to high hydrostatic pressure (HHP). While the electron transport chain and terminal reductases have been extensively studied in deep-sea bacteria, little is known about their adaptations for ATP generation. In this study, we showed that the deep-sea bacterium Photobacterium profundum SS9 exhibits a more pronounced piezophilic phenotype when grown in minimal medium supplemented with glucose (MG) than in the routinely used MB2216 complex medium. The intracellular ATP level varied with pressure, but with opposite trends in the two culture media. Between the two ATPase systems encoded in SS9, ATPase-I played a dominant role when cultivated in MB2216, whereas ATPase-II was more abundant in the MG medium, especially at elevated pressure when cells had the lowest ATP level among all conditions tested. Further analyses of the ΔatpI, ΔatpE1 and ΔatpE2 mutants showed that disrupting ATPase-I induced expression of ATPase-II and that the two systems are functionally redundant in MB2216. Collectively, we provide the first examination of the differences and relationships between two ATPase systems in a piezophilic bacterium, and expanded our understanding of the involvement of energy metabolism in pressure adaptation.

Crassaminicella indica sp. nov., a novel thermophilic anaerobic bacterium isolated from a deep-sea hydrothermal vent.

A novel moderately thermophilic heterotrophic bacterium, designated strain 143-21T, was isolated from a deep-sea hydrothermal chimney sample collected from the Central Indian Ridge at a depth of 2 440 m. Phylogenetic analysis indicated that strain 143-21T belongs to the genus Crassaminicella. It was most closely related to Crassaminicella thermophila SY095T (96.79 % 16S rRNA gene sequence similarity) and Crassaminicella profunda Ra1766HT (96.52 %). Genomic analysis showed that strain 143-21T shares 79.79-84.45 % average nucleotide identity and 23.50-29.20 % digital DNA-DNA hybridization with the species of the genus Crassaminicella, respectively. Cells were rod-shaped, non-motile, Gram-positive-staining. Terminal endospores were observed in stationary-phase cells when strain 143-21T was grown on Thermococcales rich medium. Strain 143-21T was able to grow at 30-60 °C (optimum, 50 °C), pH 6.5-8.5 (optimum, pH 7.0) and in 1.0-7.0 % NaCl (w/v; optimum 2.0 %, w/v). Strain 143-21T utilized fructose, glucose, maltose, mannose, ribose, N-acetyl-d-(+)-glucosamine and casamino acids, as well as amino acids including glutamate, lysine, histidine and cysteine. The main fermentation products from glucose were acetate (2.07 mM), H2 and CO2. It did not reduce elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate, nitrite and Fe (III). The predominant cellular fatty acids were C14 : 0 (48.8 %), C16 : 0 (12.9 %), and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c; 10.2 %). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol, as well as two unidentified phospholipids and four unidentified aminolipids. No respiratory quinones were detected. Based on its phylogenetic analysis and physiological characteristics, strain 143-21T is considered to represent a novel species of the genus Crassaminicella, for which the name Crassaminicella indica sp. nov. is proposed. The type strain is strain 143-21T (=DSM 114408T= MCCC 1K06400T).

Alzheimer's disease with sleep insufficiency: a cross-sectional study on correlations among clinical characteristics, orexin, its receptors, and the blood-brain barrier.

Previous studies have shown that reduced sleep duration, sleep fragmentation, and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling. At the same time, blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease. However, currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency. This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital. Patients were divided into two groups: those with insufficient sleep (sleep duration ≤ 6 hours, n = 19, age 61.58 ± 8.54 years, 10 men) and those with normal sleep durations (sleep duration > 6 hours, n = 31, age 63.19 ± 10.09 years, 18 men). Demographic variables were collected to evaluate cognitive function, neuropsychiatric symptoms, and activities of daily living. The levels of orexin, its receptor proteins, and several blood-brain barrier factors were measured in cerebrospinal fluid. Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains. Furthermore, levels of orexin and its receptors were upregulated in the cerebrospinal fluid, and the blood-brain barrier was destroyed. Both these events precipitated each other and accelerated the progression of Alzheimer's disease. These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation. Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease.

A new automatic stitching method for full-length lower limb radiography.

Full-length lower limb x-rays are used to diagnose and plan surgical procedures, such as Total Knee Arthroplasty (TKA) and High Tibial Osteotomy (HTO). Due to the size limitation of digital radiography (DR), panoramic x-ray images cannot be obtained in a single exposure, necessitating multiple exposures and image stitching. In favor of manually constructing full-length x-ray images, we propose a new feature-based automated method for stitching together x-ray images. This new method is based on Canny algorithm, which detects and aligns bone edges before fusing them using a Wavelet form domain. Twenty-eight sets of lower limb x-ray images obtained from our hospital have been stitched and evaluated. The hip, knee, and ankle (HKA) angle was computed in two different ways then compared to manually stitched x-ray images by an expert. The stitching time was only three seconds, and the P-value was P = 0.974, and an accuracy rate of 100% was found. This method demonstrated greater precision and speed than both manually stitched x-ray images and previously published methods.

Clinical Features and Potential Mechanisms Relating Neuropathological Biomarkers and Blood-Brain Barrier in Patients With Alzheimer's Disease and Hearing Loss.

Background: The aim of this study was to explore clinical features and potential mechanisms relating neuropathological biomarkers and blood-brain barrier (BBB) in Alzheimer's disease (AD) and hearing loss (HL). Materials and Methods: A total of 65 patients with AD were recruited and auditory function was assessed by threshold of pure tone audiometry (PTA). Patients were divided into AD with HL (AD-HL) and AD with no HL (AD-nHL) groups based on the standard of World Health Organization. Clinical symptoms were assessed by multiple rating scales. The levels of neuropathological biomarkers of ß amyloid1-42 (Aß1-42) and multiple phosphorylated tau (P-tau), and BBB factors of matrix metalloproteinases (MMPs), receptor of advanced glycation end products, glial fibrillary acidic protein, and low-density lipoprotein receptor related protein 1 were measured. Results: (1) Compared with AD-nHL group, AD-HL group had significantly impaired overall cognitive function and cognitive domains of memory, language, attention, execution, and activities of daily living (ADL) reflected by the scores of rating scales (P < 0.05). PTA threshold was significantly correlated with the impairments of overall cognitive function and cognitive domains of memory and language, and ADL in patients with AD (P < 0.05). (2) P-tau (S199) level was significantly increased in CSF from AD-HL group (P < 0.05), and was significantly and positively correlated with PTA threshold in patients with AD. (3) MMP-3 level was significantly elevated in CSF from AD-HL group (P < 0.05), and was significantly and positively correlated with PTA threshold in patients with AD (P < 0.05). (4) In AD-HL group, P-tau (S199) level was significantly and positively correlated with the levels of MMP-2 and MMP-3 in CSF (P < 0.05). Conclusion: AD-HL patients have severely compromised overall cognitive function, multiple cognitive domains, and ADL. The potential mechanisms of AD-HL involve elevations of AD neuropathological biomarker of P-tau (S199) and BBB factor of MMP-3, and close correlations between P-tau (S199) and MMP-2/MMP-3 in CSF. Findings from this investigation highly suggest significance of early evaluation of HL for delaying AD progression, and indicate new directions of drug development by inhibiting neuropathological biomarkers of AD and protecting BBB.

Dysregulated cortical synaptic plasticity under methyl-CpG binding protein 2 deficiency and its implication in motor impairments.

Caused by the mutation of methyl-CpG binding protein 2 (MeCP2), Rett syndrome leads to a battery of severe neural dysfunctions including the regression of motor coordination and motor learning. Current understanding has revealed the motor cortex as the critical region mediating voluntary movement. In this review article, we will summarize major findings from human patients and animal models regarding the cortical synaptic plasticity under the regulation of MeCP2. We will also discuss how mutation of MeCP2 leads to the disruption of cortical circuitry homeostasis to cause motor deficits. Lastly, potential values of physical exercise and neuromodulation approaches to recover neural plasticity and motor function will be evaluated. All of this evidence may help to accelerate timely diagnosis and effective interventions for Rett syndrome patients.

Influence of low air pressure on combined nitritation and anaerobic ammonium oxidation process.

At high altitude, wastewater aeration efficiency is low, which is detrimental to nitrification in conventional biological nitrogen removal. The combined partial nitritation and anaerobic ammonium oxidation (CPNA) process requires little oxygen and can be appropriate in low-pressure conditions. As such, in this study, we investigated the effect of air pressure on CPNA using a laboratory-scale reactor. We found that low air pressure promoted the removal of total inorganic nitrogen (TIN), achieving a TIN removal rate of 43,000 mg·N/(kg·VSS·d). The secretion of extracellular polymeric substances under low air pressure was not significantly different from that under ordinary air pressure, indicating no adverse effects on microbial aggregation ability, stability, or settleability. The abundance of aerobic ammonia-oxidizing bacteria (AeAOB) increased from 0.2% to 5.6%, and the activity of anaerobic ammonia-oxidizing bacteria (AnAOB) enhanced, giving AeAOB and AnAOB a competitive advantage over nitrite-oxidizing bacteria, thus forming a microbial community structure favorable to the CPNA process. Our further analysis of the results of batch tests in serum bottles confirmed the positive effect of low air pressure on the anaerobic ammonium oxidation (anammox) process, with a 28.5% ± 1.9% improvement in the specific anammox rate at 70 kPa compared with 100 kPa. AnAOB activity increased, which was reflected in the intracellular heme content increasing from 0.56 ± 0.18 µmol/(g·VSS) at 100 kPa to 2.56 ± 0.20 µmol/(g·VSS) at 70 kPa. We clarified the CPNA-process-promoting effect of low air pressure, which shows potential for nitrogen removal in high-altitude regions.

Complete genome sequence of Crassaminicella sp. 143-21，isolated from a deep-sea hydrothermal vent.

Crassaminicella sp. 143-21, a putative new species isolated from deep-sea hydrothermal vent chimney on the Central Indian Ridge (CIR), is an anaerobic, thermophilic and rod-shaped bacterium belonging to the family Clostridiaceae. In this study, we present the complete genome sequence of strain 143-21, comprising 2,756,133 bp with a G + C content of 31.1%. In total, 2427 protein coding genes, 121 tRNA genes and 33 rRNA genes were obtained. Genomic analysis of strain 143-21 revealed that numerous genes related to organic matter transport and catabolism, including peptide transport, amino acid transport, saccharide transport, ethanolamine transport and corresponding metabolic pathways. Further, the genome contains a large proportion of genes involved in translation, ribosomal structure, and signal transduction. These genes might facilitate microbial survival in deep-sea hydrothermal vent environment. The genome of strain 143-21 will be helpful for further understanding its adaptive strategies in the deep-sea hydrothermal vent environment.

Synergistic Effects of Combined Anthocyanin and Metformin Treatment for Hyperglycemia In Vitro and In Vivo.

The mechanism underlying the hypoglycemic effect of the simultaneous use of metformin and anthocyanin-rich foods is not yet clear. Hence, the effects and possible mechanisms of action of these substances, alone and in combination, were evaluated in insulin-resistant HepG2 cells and a diabetic mouse model. The results indicated that anthocyanin and metformin had a significant synergistic effect on glucose consumption (CI < 0.9) compared with metformin alone in HepG2 cells. In the mouse model, combined treatment (50 and 100 mg/kg metformin + anthocyanin groups) demonstrated synergistic restorative effects on the blood glucose level, insulin resistance, and organ damage in the liver, pancreas, and ileum. Additionally, combined metformin and anthocyanin treatment suppressed protein tyrosine phosphatase 1B expression and regulated the PI3K/AKT/GSK3ß pathway. Combined treatment also altered the gut microbial composition and structure by increasing the relative abundance of beneficial bacteria and the short-chain fatty acid content. These results suggest that the use of anthocyanins can enhance the efficacy of metformin treatment for hyperglycemia and provide a reference for further clinical research regarding nutrition and supplementary treatment.

Potential roles of oxidative distress on neurodegeneration in Parkinson's disease with neuropsychiatric symptoms.

Background: Neuropsychiatric symptoms (NPSs) belong to a category of non-motor symptoms of Parkinson's disease (PD), which seriously compromise the quality of life and prognosis of PD. This study focused on the correlations between NPSs, free radicals, neuroinflammatory factors, and neuropathological proteins in cerebrospinal fluid (CSF) in patients with PD, aiming to provide insights into the potential mechanisms and therapeutic target for PD with NPSs (PD-NPSs). Methods: In total, 129 patients with PD were enrolled and assessed by the Neuropsychiatric Symptoms Inventory (NPI); they were divided into the PD-NPSs group (75 patients) and PD with no NPSs (PD-nNPSs) group (54 patients). The levels of hydrogen peroxide (H2O2) and nitric oxide (NO), and hydroxyl radical (·OH), anti-oxidative enzyme, neuroinflammatory factors, and neuropathological proteins in CSF from patients with PD were measured. The levels of the above variables were compared between PD-NPSs and PD-nNPSs groups, and correlation analyses among the above variables were conducted. Results: (1) The levels of H2O2 and NO in CSF from the PD-NPSs group were significantly elevated compared with the PD-nNPSs group (p = 0.001), and NPI score positively correlated with the levels of H2O2 and NO (r = 0.283, P = 0.001; r = 0.231, P = 0.008). Reversely, total superoxide dismutase (tSOD) activity in CSF from the PD-NPSs group was significantly reduced compared with the PD-nNPSs group (p = 0.011), and negatively correlated with NPI score (r = -0.185, p = 0.036). (2) The tumor necrosis factor (TNF)-α level in CSF from the PD-NPSs group was significantly decreased compared with the PD-nNPSs group (p = 0.002) and negatively correlated with NPI score (r = -0.211, p = 0.016). (3) The total tau (T-tau) level in CSF from the PD-NPSs group was significantly higher than in the PD-nNPSs group (p = 0.014) and positively correlated with the NPI score (r = 0.167, p = 0.060). (4) The levels of H2O2 and NO positively correlated with the T-tau level in CSF from the PD-NPSs group (r = 0.183, p = 0.039; r = 0.251, P = 0.004), and the levels of TNF-α and T-tau showed a negative correlation (r = -0.163, p = 0.067). Conclusion: Oxidative distress characterized by the elevations of H2O2 and NO levels may closely correlate with the neurodegeneration in brain regions related to PD-NPSs. Thus, therapeutic antioxidants may become an important target for PD-NPSs therapy.

Metagenomic analysis reveals wide distribution of phototrophic bacteria in hydrothermal vents on the ultraslow-spreading Southwest Indian Ridge.

Deep-sea hydrothermal vents are known as chemosynthetic ecosystems. However, high temperature vents emit light that hypothetically can drive photosynthesis in this habitat. Metagenomic studies have sporadically reported the occurrence of phototrophic populations such as cyanobacteria in hydrothermal vents. To determine how geographically and taxonomically widespread phototrophs are in deep-sea hydrothermal vents, we collected samples from three niches in a hydrothermal vent on the Southwest Indian Ridge and carried out an integrated metagenomic analysis. We determined the typical community structures of microorganisms found in active venting fields and identified populations of known potential chlorophototrophs and retinalophototrophs. Complete chlorophyll biosynthetic pathways were identified in all samples. By contrast, proteorhodopsins were only found in active beehive smoker diffusers. Taxonomic groups possessing potential phototrophy dependent on semiconductors present in hydrothermal vents were also found in these samples. This systematic comparative metagenomic study reveals the widespread distribution of phototrophic bacteria in hydrothermal vent fields. Our results support the hypothesis that the ocean is a seed bank of diverse microorganisms. Geothermal vent light may provide energy and confer a competitive advantage on phototrophs to proliferate in hydrothermal vent ecosystems. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-021-00121-y.

Crassaminicella thermophila sp. nov., a moderately thermophilic bacterium isolated from a deep-sea hydrothermal vent chimney and emended description of the genus Crassaminicella.

A novel moderately thermophilic, anaerobic, heterotrophic bacterium (strain SY095T) was isolated from a hydrothermal vent chimney located on the Southwest Indian Ridge at a depth of 2730 m. Cells were Gram-stain-positive, motile, straight to slightly curved rods forming terminal endospores. SY095T was grown at 45-60 °C (optimum 50-55 °C), pH 6.0-7.5 (optimum 7.0), and in a salinity of 1-4.5 % (w/v) NaCl (optimum 2.5 %). Substrates utilized by SY095T included fructose, glucose, maltose, N-acetyl glucosamine and tryptone. Casamino acid and amino acids (glutamate, glutamine, lysine, methionine, serine and histidine) were also utilized. The main end products from glucose fermentation were acetate, H2 and CO2. Elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C14 : 0 (60.5%) and C16 : 0 (7.6 %). The main polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, five unidentified phospholipids and two unidentified aminophospholipids. No respiratory quinones were detected. The chromosomal DNA G+C content was 30.8 mol%. The results of phylogenetic analysis of the 16S rRNA gene sequences indicated that SY095T was closely related to Crassaminicella profunda Ra1766HT (95.8 % 16S rRNA gene sequence identity). SY095T exhibited 78.1 % average nucleotide identity (ANI) to C. profunda Ra1766HT. The in silico DNA-DNA hybridization (DDH) value indicated that SY095T shared 22.7 % DNA relatedness with C. profunda Ra1766HT. On the basis of its phenotypic, genotypic and phylogenetic characteristics, SY095T is suggested to represent a novel species of the genus Crassaminicella, for which the name Crassaminicella thermophila sp. nov. is proposed. The type strain is SY095T (=JCM 34213=MCCC 1K04191). An emended description of the genus Crassaminicella is also proposed.

Thermococcus aciditolerans sp. nov., a piezotolerant, hyperthermophilic archaeon isolated from a deep-sea hydrothermal vent chimney in the Southwest Indian Ridge.

A hyperthermophilic, strictly anaerobic archaeon, designated strain SY113T, was isolated from a deep-sea hydrothermal vent chimney on the Southwest Indian Ridge at a water depth of 2770 m. Enrichment and isolation of strain SY113T were performed at 85 °C at 0.1 MPa. Cells of strain SY113T were irregular motile cocci with peritrichous flagella and generally 0.8-2.4 µm in diameter. Growth was observed at temperatures between 50 and 90 °C (optimum at 85 °C) and under hydrostatic pressures of 0.1-60 MPa (optimum, 27 MPa). Cells of SY113T grew at pH 4.0-9.0 (optimum, pH 5.5) and a NaCl concentration of 0.5-5.5 % (w/v; optimum concentration, 3.0 % NaCl). Strain SY113T was an anaerobic chemoorganoheterotroph and grew on complex proteinaceous substrates such as yeast extract and tryptone, as well as on maltose and starch. Elemental sulphur stimulated growth, but not obligatory for its growth. The G+C content of the genomic DNA was 55.0 mol%. Phylogenetic analysis of the 16S rRNA sequence of strain SY113T showed that the novel isolate belonged to the genus Thermococcus. On the basis of physiological characteristics, average nucleotide identity values and in silico DNA-DNA hybridization results, we propose a novel species, named Thermococcus aciditolerans sp. nov. The type strain is SY113T (=MCCC 1K04190T=JCM 39083T).