Unraveling the relationship between high-sensitivity C-reactive protein and frailty: evidence from longitudinal cohort study and genetic analysis.

BACKGROUND: This study aimed to investigate the association of high-sensitivity C-reactive protein (hs-CRP) with incident frailty as well as its effects on pre-frailty progression and regression among middle-aged and older adults. METHODS: Based on the frailty index (FI) calculated with 41 items, 6890 eligible participants without frailty at baseline from China Health and Retirement Longitudinal Study (CHARLS) were categorized into health, pre-frailty, and frailty groups. Logistic regression models were used to estimate the longitudinal association between baseline hs-CRP and incident frailty. Furthermore, a series of genetic approaches were conducted to confirm the causal relationship between CRP and frailty, including Linkage disequilibrium score regression (LDSC), pleiotropic analysis, and Mendelian randomization (MR). Finally, we evaluated the association of hs-CRP with pre-frailty progression and regression. RESULTS: The risk of developing frailty was 1.18 times (95% CI: 1.03-1.34) higher in participants with high levels of hs-CRP at baseline than low levels of hs-CRP participants during the 3-year follow-up. MR analysis suggested that genetically determined hs-CRP was potentially positively associated with the risk of frailty (OR: 1.06, 95% CI: 1.03-1.08). Among 5241 participants with pre-frailty at baseline, we found pre-frailty participants with high levels of hs-CRP exhibit increased odds of progression to frailty (OR: 1.39, 95% CI: 1.09-1.79) and decreased odds of regression to health (OR: 0.84, 95% CI: 0.72-0.98) when compared with participants with low levels of hs-CRP. CONCLUSIONS: Our results suggest that reducing systemic inflammation is significant for developing strategies for frailty prevention and pre-frailty reversion in the middle-aged and elderly population.

Structure of the SARS-CoV-2 RNA-dependent RNA polymerase in the presence of favipiravir-RTP.

The RNA polymerase inhibitor favipiravir is currently in clinical trials as a treatment for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), despite limited information about the molecular basis for its activity. Here we report the structure of favipiravir ribonucleoside triphosphate (favipiravir-RTP) in complex with the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) bound to a template:primer RNA duplex, determined by electron cryomicroscopy (cryoEM) to a resolution of 2.5 Å. The structure shows clear evidence for the inhibitor at the catalytic site of the enzyme, and resolves the conformation of key side chains and ions surrounding the binding pocket. Polymerase activity assays indicate that the inhibitor is weakly incorporated into the RNA primer strand, and suppresses RNA replication in the presence of natural nucleotides. The structure reveals an unusual, nonproductive binding mode of favipiravir-RTP at the catalytic site of SARS-CoV-2 RdRp, which explains its low rate of incorporation into the RNA primer strand. Together, these findings inform current and future efforts to develop polymerase inhibitors for SARS coronaviruses.

PKM2 is a Novel Osteoporosis-Associated Protein in Chinese.

Purpose:Osteoporosis is characterized by low bone mineral density (BMD) and high risk of osteoporotic fracture (OF). Peripheral blood monocytes (PBM) can differentiate into osteoclasts to resorb bone. This study was to identify PBM-expressed proteins significant for osteoporosis in Chinese Han elderly population (>65 years), and focused on two phenotypes of osteoporosis: low BMD and OF. METHODS: Label-free quantitative proteomics was employed to profile PBM proteome and to identify differentially expressed proteins (DEPs) between OF (N=27) vs. non-fractured (NF, N=24) subjects and between low BMD (N=12) vs. high BMD (N=12) subjects in women. Western blotting (WB) was conducted to validate differential expression, and ELISA to evaluate translational value for secretory protein of interest. RESULTS: We discovered 59 DEPs with fold change (FC)>1.3 (P<1×10-5), and validated the significant up-regulation of pyruvate kinase isozyme 2 (PKM2) with osteoporosis (P<0.001). PKM2 protein upregulation with OF was replicated with PBM in men (P=0.04). Plasma PKM2 protein level was significantly elevated with OF in an independent sample (N=100, FC=1.68, P=0.01). Pursuant functional assays showed that extracellular PKM2 protein supplement not only promoted monocyte trans-endothelial migration, growth, and osteoclast differentiation (marker gene expression), but also inhibited osteoblast growth, differentiation (ALP gene expression), and activity. CONCLUSION: The above findings suggest that PKM2 protein is a novel osteoporosis-associated functional protein in Chinese Han elderly population. It may serve as a risk biomarker and drug target for osteoporosis.

A novel long non-coding RNA, lnc-RNU12, influences the T-cell cycle via c-JUN and CCNL2 in rheumatoid arthritis.

OBJECTIVES: Long non-coding RNAs (lncRNAs) play important roles in RA pathogenesis. However, specific lncRNAs that regulate gene expression in RA pathogenesis are poorly known. This study was undertaken to characterize a novel lncRNA (lnc-RNU12) that has a lower-than-normal expression level in RA patients. METHODS: We performed initial genome-wide lncRNA microarray screening in peripheral blood mononuclear cells from 28 RA cases and 18 controls. Multiple methods were used to validate the detected associations between lncRNAs and RA. Furthermore, we identified the source and characteristics of the highlighted lncRNAs, detected the target genes, and determined the functional effect on immune cells through lncRNA knock-down in Jurkat T cell lines. RESULTS: lnc-RNU12 was downregulated in peripheral blood mononuclear cells and T cell subtypes of RA patients and was genetically associated with RA risk. lnc-RNU12 mediates the effect of microbiome alterations on RA risk. Activation of T cells caused low expression of lnc-RNU12. Knock-down of lnc-RNU12 in Jurkat T cells caused cell cycle S-phase arrest and altered the expression of protein-coding genes related to the cell cycle and apoptosis (e.g. c-JUN, CCNL2, CDK6, MYC, RNF40, PKM, VPS35, DNAJB6 and FLCN). Finally, c-JUN and CCNL2 were identified as target genes of lnc-RNU12 at the mRNA and protein expression levels. RNA-binding protein immunoprecipitation assays verified the interaction between lnc-RNU12 and the two proteins (c-Jun and cyclin L2) in Jurkat cells. CONCLUSIONS: Our study suggested that lnc-RNU12 was involved in the pathogenesis of RA by influencing the T cell cycle by targeting c-JUN and CCNL2.

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).

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).

Effects of static magnetic field on the sulfate metabolic pathway involved in Magnetospirillum magneticum AMB-1 cell growth and magnetosome formation.

AIMS: Magnetotactic bacteria (MTB) can use their unique intracellular magnetosome organelles to swim along the Earth's magnetic field. They play important roles in the biogeochemical cycles of iron and sulfur. Previous studies have shown that the applied magnetic fields could affect the magnetosome formation and antioxidant defense systems in MTB. However, the molecular mechanisms by which magnetic fields affect MTB cells remain unclear. We aim to better understand the dark at 28°C-29°C for 20 h, as shownthe interactions between magnetic fields and cells, and the mechanism of MTB adaptation to magnetic field at molecular levels. METHODS AND RESULTS: We performed microbiological, transcriptomic, and genetic experiments to analyze the effects of a weak static magnetic field (SMF) exposure on the cell growth and magnetosome formation in the MTB strain Magnetospirillum magneticum AMB-1. The results showed that a 1.5 mT SMF significantly promoted the cell growth but reduced magnetosome formation in AMB-1, compared to the geomagnetic field. Transcriptomic analysis revealed decreased expression of genes primarily involved in the sulfate reduction pathway. Consistently, knockout mutant lacking adenylyl-sulfate kinase CysC did no more react to the SMF and the differences in growth and Cmag disappeared. Together with experimental findings of increased reactive oxidative species in the SMF-treated wild-type strain, we proposed that cysC, as a key gene, can participate in the cell growth and mineralization in AMB-1 by SMF regulation. CONCLUSIONS: This study suggests that the magnetic field exposure can trigger a bacterial oxidative stress response involved in AMB-1 growth and magnetosome mineralization by regulating the sulfur metabolism pathway. CysC may serve as a pivotal enzyme in mediating sulfur metabolism to synchronize the impact of SMF on both growth and magnetization of AMB-1.

Template-Free Assembly of Functional RNAs by Loop-Closing Ligation.

The first ribozymes are thought to have emerged at a time when RNA replication proceeded via nonenzymatic template copying processes. However, functional RNAs have stable folded structures, and such structures are much more difficult to copy than short unstructured RNAs. How can these conflicting requirements be reconciled? Also, how can the inhibition of ribozyme function by complementary template strands be avoided or minimized? Here, we show that short RNA duplexes with single-stranded overhangs can be converted into RNA stem loops by nonenzymatic cross-strand ligation. We then show that loop-closing ligation reactions enable the assembly of full-length functional ribozymes without any external template. Thus, one can envisage a potential pathway whereby structurally complex functional RNAs could have formed at an early stage of evolution when protocell genomes might have consisted only of collections of short replicating oligonucleotides.

Why SNP rs3755955 is associated with human bone mineral density? A molecular and cellular study in bone cells.

SNP rs3755955 (major/minor allele: G/A) located in Iduronidase-Alpha-L- (IDUA) gene was reported to be significant for human bone mineral density (BMD). This follow-up study was to uncover the underlying association mechanism through molecular and cellular functional assays relevant to bone. We tested the effects of single nucleotide polymorphisms (SNP) rs3755955 (defined allele G as wild-type and allele A as variant-type) on osteoblastic and osteoclastic functions, as well as protein phosphorylation in stably transfected human fetal osteoblast (hFOB) cell and mononuclear-macrophage (RAW264.7) cell. In hFOB cells, transfection with variant-type IDUA significantly decreased osteoblastic gene expression (OPN, COL1A1 and RANKL) (p < 0.01), impeded cell proliferation (p < 0.05), stimulated cell apoptosis (p < 0.001) and decreased ALP enzyme activity, as compared with that of wild-type IDUA transfection. In RAW264.7 cells, transfection with variant-type IDUA significantly inhibited cell apoptosis (p < 0.01), promoted osteoclastic precursor cell migration (p < 0.0001), growth (p < 0.01), osteoclastic gene expression (TRAP, RANK, Inte-αv and Cath-K) (p < 0.05) and TRAP enzyme activity (p < 0.001), as compared with that of wild-type IDUA transfection. In both hFOB and RAW264.7 cells, the total protein and IDUA protein-specific phosphorylation levels were significantly reduced by variant IDUA transfection, as compared with that of wild-type IDUA transfection (p < 0.05). Variant allele A of phosSNP rs3755955 in IDUA gene regulates protein phosphorylation, inhibits osteoblast function and promotes osteoclastic activity. The SNP rs3755955 could alter IDUA protein phosphorylation, significantly regulates human osteoblastic and osteoclastic gene expression, and influences the growth, differentiation and activity of osteoblast and osteoclast, hence to affect BMD.

Predictors of portal vein thrombosis after laparoscopic splenectomy and azygoportal disconnection in hepatitis B cirrhosis: a prospective study.

BACKGROUND: The thrombosis of the main and intrahepatic branches of the portal vein (TMIP) is potentially lethal and deemed a common complication following laparoscopic splenectomy and azygoportal disconnection (LSD) in patients with cirrhosis and portal hypertension (PH). The predictors of TMIP after LSD remain unclear. The aim of this prospective study was to explore the predictive and risk factors for TMIP after LSD in cirrhotic patients with PH caused only by hepatitis B virus. METHODS: From September 2014 to March 2017, we enrolled 115 patients with hepatitis B cirrhosis and PH who successfully underwent LSD. Patients were subdivided into a TMIP group and a non-TMIP group. Univariate and multivariate logistic regression analysis was conducted on 24 items of demographic and preoperative data, to explore the risk factors of TMIP. RESULTS: Twenty-nine (25.22%) patients developed TMIP on postoperative day (POD) 7 and 26 (22.81%) patients developed TMIP on POD 30. From POD 7 to POD 30, 12 patients who did not have TMIP at POD 7 were newly diagnosed with TMIP, with portal vein diameter 15.05 ± 2.58 mm. Another 14 patients in whom TMIP had resolved had portal vein diameter 14.02 ± 1.76 mm. Univariate analysis and multivariate logistic regression revealed that portal vein diameter ≥ 13 mm [relative risk (RR) 5.533, 95% confidence interval (CI) 1.222-25.042; P = 0.026] and portal vein diameter ≥ 15 mm (RR 3.636, 95% CI 1.466-9.021; P = 0.005) were significant independent risk factors for TMIP on POD 7 and 30, respectively. CONCLUSION: Portal vein diameter ≥ 13 mm and ≥ 15 mm were significant independent predictors for TMIP after LSD in patients with hepatitis B cirrhosis and PH on POD 7 and POD 30, respectively. TRIAL REGISTRATION: We registered our research at https://www. CLINICALTRIALS: gov/ . The name of research registered is "Warfarin Prevents Portal Vein Thrombosis in Patients After Laparoscopic Splenectomy and Azygoportal Disconnection." The trial registration identifier at clinicaltrials.gov is NCT02247414.

Clinical effects of cluster technology optimization and innovations on laparoscopic splenectomy and azygoportal disconnection: a single-center retrospective study with 500 consecutive cases.

BACKGROUND: In Asia, laparoscopic splenectomy and azygoportal disconnection (LSD) has been widely regarded as a preferential treatment modality for cirrhotic portal hypertension (PH). However, LSD involves high surgical risk, technical challenges, and many potential postoperative complications. Technology optimization and innovation in LSD aiming to solve to these difficulties has scarcely been reported. In this retrospective study, we aimed to evaluate the clinical therapeutic effect of our cluster technology optimization and innovation on LSD for PH. METHODS: From February 2012 to January 2020, 500 patients with cirrhosis who had esophagogastric variceal bleeding and hypersplenism underwent LSD in our department. According to different operation periods, patients were divided into the early-, intermediate-, and late-period groups. We collected information regarding clinical characteristics of all patients as well as their preoperative and postoperative follow-up data. RESULTS: Compared with the early-period group, operation time and postoperative hospital stay were all significantly different and gradually declined from the intermediate- and late-period groups, respectively (all P < 0.05). Intraoperative blood loss of these three groups was gradually decreased, with significant differences (P < 0.05). The incidences of delayed gastric emptying and diarrhea in the late-period group were all significantly lower than those in the early- and intermediate-period groups, respectively (all P < 0.05). Compared with the early-period group, the incidence of variceal re-bleeding was significantly lower in the intermediate- and late-period groups (all P < 0.05). CONCLUSION: Our cluster technology optimization and innovation of LSD not only contributed to faster recovery and fewer complications but also enhanced surgical safety for patients. It is worth promoting this approach among patients with EVB and hypersplenism secondary to cirrhotic PH.

Body Surface Area (BSA) is a Better Osteoporosis Associated Anthropometric Parameter Than Other Anthropometric Parameters in Elderly Population.

Body surface area (BSA) is widely used for adjusting drug dose, while few studies have yet systematically evaluated its association with osteoporosis and compared its advantage with other anthropometric parameters in osteoporotic risk prediction. A total of 10,021 Chinese individuals aged over 65 years were enrolled in our study. Bone mineral density (BMD) was measured, and demographic information was also collected. Pearson correlation analysis, receiver operating characteristic (ROC) curves and predictive analysis were performed to assess the clinical practice of BSA for osteoporosis. BSA had the strongest correlation with BMD (0.544, p < 0.001) compared with conventional anthropometric indices. Besides, BSA had the highest power in osteoporosis prediction, with an area under the curve (AUC) reaching 0.81. After incorporating BSA into the osteoporosis risk prediction model, the AUC improved from 0.82 to 0.83 (p < 0.01). We found BSA provided additional diagnostic value beyond conventional anthropometric information with continuous and category NRIs were 30.40% (p < 0.01) and 3.29% (p < 0.01), respectively, and the IDI was 1.85% (p < 0.01). BSA was positively associated with osteoporosis and showed superior discriminative ability for osteoporosis risk prediction compared with other anthropometric parameters in the Chinese elderly population.

Interstrand Aminoacyl Transfer in a tRNA Acceptor Stem-Overhang Mimic.

Protein-catalyzed aminoacylation of the 3'-overhang of tRNA by an aminoacyl-adenylate could not have taken place prior to the advent of genetically coded peptide synthesis, and yet the latter process has an absolute requirement for aminoacyl-tRNA. There must therefore have been an earlier nonprotein-catalyzed means of generating aminoacyl-tRNA. Here, we demonstrate efficient interstrand aminoacyl transfer from an aminoacyl phosphate mixed anhydride at the 5'-terminus of a tRNA acceptor stem mimic to the 2',3'-diol terminus of a short 3'-overhang. With certain five-base 3'-overhangs, the transfer of an alanyl residue is highly stereoselective with the l-enantiomer being favored to the extent of ∼10:1 over the d-enantiomer and is much more efficient than the transfer of a glycyl residue. N-Acyl-aminoacyl residues are similarly transferred from a mixed anhydride with the 5'-phosphate to the 2',3'-diol but with a different dependence of efficiency and stereoselectivity on the 3'-overhang length and sequence. Given a prebiotically plausible and compatible synthesis of aminoacyl phosphate mixed anhydrides, these results suggest that RNA molecules with acceptor stem termini resembling modern tRNAs could have been spontaneously aminoacylated, in a stereoselective and chemoselective manner, at their 2',3'-diol termini prior to the onset of protein-catalyzed aminoacylation.

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).

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.

Novel noninvasive liver fibrotic markers to predict postoperative re-bleeding after laparoscopic splenectomy and azygoportal disconnection: a 1-year prospective study.

BACKGROUND: Esophagogastric variceal re-bleeding (EGVR) is a common and potentially lethal complication after open or laparoscopic splenectomy and azygoportal disconnection (LSD) in patients with cirrhosis and portal hypertension. Currently, noninvasive biomarkers for predicting EGVR are lacking. This prospective study focused on developing a noninvasive and convenient clinical model for predicting postoperative EGVR. METHODS: Between September 2014 and March 2017, we enrolled 164 patients with cirrhosis who successfully underwent LSD. Based on the absence or presence of EGVR, patients were divided into EGVR and non-EGVR groups. We used correlation analysis to determine significant candidate variables among the liver fibrotic markers procollagen type III (PC-III), hyaluronidase (HA), laminin (LN), and type IV collagen (C-IV). RESULTS: Postoperative EGVR occurred in 22 (13.41%) patients. Correlation analyses showed that LN (r = 0.375; p < 0.001) and C-IV (r = 0.349; p < 0.001) were significantly positively associated with EGVR. The area under the receiver operating characteristic curve (AUC) of LN was 0.817 (95% confidence interval [CI] 0.722-0.913); that of C-IV was 0.795 (95% CI 0.710-0.881). In logistic multivariate regression, cutoff values LN ≥ 64 µg/L and of C-IV ≥ 65 µg/L were independent risk factors for EGVR. LN ≥ 64 µg/L combined with C-IV ≥ 65 µg/L was the best performing model, with AUC 0.867 (95% CI 0.768-0.967). CONCLUSION: LN and C-IV are potential markers to predict EGVR. Combining the two markers showed satisfactory ability to predict EGVR in patients with cirrhosis and portal hypertension after LSD.

Juxtaposed membranes underpin cellular adhesion and display unilateral cell division of multicellular magnetotactic prokaryotes.

Multicellular magnetotactic prokaryotes (MMPs) exhibit peculiar coordination of swimming along geomagnetic field lines. Approximately 40-80 cells assemble, with a helical geometry or axisymmetry, into spherical or ellipsoidal MMPs respectively. To contribute to a comprehensive understanding of bacterial multicellularity here we took multiple microscopic approaches to study the diversity, assembly, reproduction and motility of ellipsoidal MMPs. Using correlative fluorescence in situ hybridization and scanning electron microscopy analysis, we found an unexpected diversity in populations of ellipsoidal MMPs in the Mediterranean Sea. The high-pressure freezing/freeze substitution fixation technique allowed us to show, for the first time, that cells adhere via juxtaposed membranes and are held together by a rimming lattice. Fluorescence confocal microscopy and ultrathin section images revealed not only the one-layer hollow three-dimensional architecture, but also periphery-core unilateral constriction of constituent cells and unidirectional binary fission of the ellipsoidal MMPs. This finding suggests the evolution toward MMPs multicellularity via the mechanism of incomplete separation of offspring. Remarkably, thousands of flagellar at the periphery surface of cells underpin the coordinated swimming of MMPs in response to mechanical, chemical, magnetic and optical stimuli, including a magnetotactic photokinesis behaviour. Together these results unveil the unique structure and function property of ellipsoidal MMPs.

Protein array test detected three osteoporosis related plasma inflammatory cytokines in Chinese postmenopausal women.

Inflammatory cytokines were involved in pathological conditions of osteoporosis (OP). However, the specific OP-associated inflammatory cytokines are still awaiting to be detected by using a systemic method. Herein, we adopted an extreme sampling scheme and examined inflammatory cytokines between subjects with low and high bone mineral density (BMD) through protein microarray. First, 8 candidate cytokines including B lymphocyte chemoattractant (BLC), osteopontin (OPN) and insulin-like growth factor-binding protein 4 (IGFBP4) were identified in the discovery extreme sampling subgroup. Then, the different expressions for BLC, OPN and IGFBP4 were validated and replicated in two independent extreme sampling subgroups. Further functional experiments showed that the cytokine BLC was involved in bone metabolism by inhibiting bone formation and promoting bone resorption. Together, this study further revealed that inflammatory cytokines were closely related with OP, and that they highlighted critical roles of BLC in the pathogenesis of OP.

Light regulation of resistance to oxidative damage and magnetic crystal biogenesis in Magnetospirillum magneticum mediated by a Cys-less LOV-like protein.

Light-oxygen-voltage (LOV) proteins are ubiquitous photoreceptors that can interact with other regulatory proteins and then mediate their activities, which results in cellular adaptation and subsequent physiological changes. Upon blue-light irradiation, a conserved cysteine (Cys) residue in LOV covalently binds to flavin to form a flavin-Cys adduct, which triggers a subsequent cascade of signal transduction and reactions. We found a group of natural Cys-less LOV-like proteins in magnetotactic bacteria (MTB) and investigated its physiological functions by conducting research on one of these unusual LOV-like proteins, Amb2291, in Magnetospirillum magneticum. In-frame deletion of amb2291 or site-directive substitution of alanine-399 for Cys mutants impaired the protective responses against hydrogen peroxide, thereby causing stress and growth impairment. Consequently, gene expression and magnetosome formation were affected, which led to high sensitivity to oxidative damage and defective phototactic behaviour. The purified wild-type and A399C-mutated LOV-like proteins had similar LOV blue-light response spectra, but Amb2291A399C exhibited a faster reaction to blue light. We especially showed that LOV-like protein Amb2291 plays a role in magnetosome synthesis and resistance to oxidative stress of AMB-1 when this bacterium was exposed to red light and hydrogen peroxide. This finding expands our knowledge of the physiological function of this widely distributed group of photoreceptors and deepens our understanding of the photoresponse of MTB. KEY POINTS: • We found a group of Cys-less light-oxygen-voltage (LOV) photoreceptors in magnetotactic bacteria, which prompted us to study the light-response and biological roles of these proteins in these non-photosynthetic bacteria. • The Cys-less LOV-like protein participates in the light-regulated signalling pathway and improves resistance to oxidative damage and magnetic crystal biogenesis in Magnetospirillum magneticum. • This result will contribute to our understanding of the structural and functional diversity of the LOV-like photoreceptor and help us understand the complexity of light-regulated model organisms.