Faecalicatena faecalis sp. nov., a moderately alkaliphilic bacterial strain isolated from swine faeces

An obligately anaerobic, Gram-stain-positive, non-motile, non-spore-forming and rod-shaped strain AGMB00832^T was isolated from swine faeces. Phylogenetic analysis based on the 16S rRNA gene, together with the housekeeping genes, gyrB and rpoD, revealed that strain AGMB00832^T belonged to the genus Faecalicatena and was most closely related to Faecalicatena orotica KCTC 15331^T. In biochemical analysis, strain AGMB00832^T was shown to be negative for catalase, oxidase and urease. Furthermore, the isolate was positive for β-glucosidase, β-glucuronidase, glutamic acid decarboxylase, proline arylamidase, acid phosphatase and naphthol-AS-BI-phosphohydrolase. The major cellular fatty acids (>?10%) of the isolate were C_14:0, C_16:0 and C_18:1ω11t DMA. Based on the whole genome sequence analysis, the DNA G?+?C content of strain AGMB00832^T was 44.2 mol%, and the genome size and numbers of rRNA and tRNA genes were 5,175,159 bp, 11 and 53, respectively. The average nucleotide identity and digital DNA–DNA hybridization values between strain AGMB00832^T and related strains were ≤?77.4 and 22.5%, respectively. Furthermore, the genome analysis revealed the presence of genes for alkaline shock protein 23 and cation/proton antiporters, which may facilitate growth of strain AGMB00832^T in alkaline culture condition. On the basis of polyphasic taxonomic approach, strain AGMB00832^T represents a novel species within the genus Faecalicatena, for which the name Faecalicatena faecalis sp. nov. is proposed. The type strain is AGMB00832^T (=?KCTC 15946^T?=?NBRC 114613^T).

     

Anaerocolumna sedimenticola sp. nov., isolated from fresh water sediment

Strain CBA3638^T was isolated from the Geum River sediment, Republic of Korea. The cells of strain CBA3638^T were Gram-stain-positive, strictly anaerobic, rod-shaped, and 0.5–1.0 μm wide, and 4.0–4.5 μm long. Optimal growth occurred at 37 °C, pH 7.0, and 1.0% (w/v) NaCl. Based on the 16S rRNA gene sequence, the phylogenetic analysis showed that strain CBA3638^T belongs to the genus Anaerocolumna in the family Lachnospiraceae, and is most closely related to Anaerocolumna cellulosilytica (94.6–95.0%). The DDH value with A. cellulosilytica SN021^T showed 15.0% relatedness. The genome of strain CBA3638^T consisted of one circular chromosome that is 5,500,435 bp long with a 36.7 mol% G?+?C content. The genome contained seven 16S-5S-23S rRNA operons and one antibiotic resistance-related transporter gene (mefA). Quinones were not detected. The predominant cellular fatty acids were C_16:0 and C_14:0 and the polar lipids were diphosphatidylglycerol, phosphatidylcholine, and uncharacterised polar lipids. Based on the polyphasic taxonomic analysis, we propose strain CBA3638^T as a novel species in the genus Anaerocolumna, with the name Anaerocolumna sedimenticola sp. nov. The type strain is CBA3638^T (=?KACC 21652^T?=?DSM 110663^T).

     

O-GlcNAc modification of nuclear pore complexes accelerates bidirectional transport

Macromolecular transport across the nuclear envelope depends on facilitated diffusion through nuclear pore complexes (NPCs). The interior of NPCs contains a permeability barrier made of phenylalanine-glycine (FG) repeat domains that selectively facilitates the permeation of cargoes bound to nuclear transport receptors (NTRs). FG-repeat domains in NPCs are a major site of O-linked N-acetylglucosamine (O-GlcNAc) modification, but the functional role of this modification in nucleocytoplasmic transport is unclear. We developed high-throughput assays based on optogenetic probes to quantify the kinetics of nuclear import and export in living human cells. We found that increasing O-GlcNAc modification of the NPC accelerated NTR-facilitated transport of proteins in both directions, and decreasing modification slowed transport. Superresolution imaging revealed strong enrichment of O-GlcNAc at the FG-repeat barrier. O-GlcNAc modification also accelerated passive permeation of a small, inert protein through NPCs. We conclude that O-GlcNAc modification accelerates nucleocytoplasmic transport by enhancing the nonspecific permeability of the FG-repeat barrier, perhaps by steric inhibition of interactions between FG repeats.     

High Endemicity with Clonorchis sinensis Metacercariae in Fish from Yongjeon-cheon (Stream) in Cheongsong-gun,Gyeongsangbuk-do,Korea

The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yongjeon-cheon (a branch of Nakdong-gang) located in Cheongsong-gun, Gyeongsangbuk-do, the Republic of Korea (Korea). A total of 750 fishes in 19 species were examined by the artificial digestion method for 2 years (2019 and 2020). CsMc were detected in 378 (51.4%) out of 735 fishes in 14 species (73.7%), and the infection intensity was 666 per fish infected. In 2019, CsMc were found in 172 (68.0%) out of 253 fishes in 10 species, and the infection intensity was 565 per fish infected. In 2020, CsMc were detected in 206 (62.2%) out of 331 fishes in 10 species, and the infection intensity was 751 per fish infected. The other zoonotic trematode, ie. Metagonimus spp., Centrocestus armatus, Echinostoma spp. and Clinostomum complanatum, metacercariae were also detected in fishes from the survey streams, but their endemicities were relatively low. Conclusively, it was first confirmed that CsMc are highly endemic in fishes from Yongjeon-cheon in Cheongsong-gun, Gyeongsangbuk-do, Korea.     

A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland

Virologica Sinica - Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral...     

Relationship of the lung microbiome with PD-L1 expression and immunotherapy response in lung cancer

IL-35 subunit EBI3 is up-regulated in pulmonary fibrosis tissues. In this study, we investigated the pathological role of EBI3 in pulmonary fibrosis and dissected the underlying molecular mechanism. Bleomycin-induced pulmonary fibrosis mouse model was established, and samples were performed gene expression analyses through RNAseq, qRT-PCR and Western blot. Wild type and EBI3 knockout mice were exposed to bleomycin to investigate the pathological role of IL-35, via lung function and gene expression analyses. Primary lung epithelial cells were used to dissect the regulatory mechanism of EBI3 on STAT1/STAT4 and STAT3. IL-35 was elevated in both human and mouse with pulmonary fibrosis. EBI3 knockdown aggravated the symptoms of pulmonary fibrosis in mice. EBI3 deficiency enhanced the expressions of fibrotic and extracellular matrix-associated genes. Mechanistically, IL-35 activated STAT1 and STAT4, which in turn suppressed DNA enrichment of STAT3 and inhibited the fibrosis process. IL-35 might be one of the potential therapeutic targets for bleomycin-induced pulmonary fibrosis.     

Peptides YYGGEGSSSEQG and SESEM Inhibit TNF-α-Induced Smooth Muscle Cells Proliferation and Migration Through Their Bindings to TNF-α Receptor

International Journal of Peptide Research and Therapeutics - The peptides YYGGEGSSSEQG and SESEM derived from rice α-globulin have been reported to possess anti-atherosclerotic activity, but...     

The Golgi complex: a hub of the secretory pathway

The Golgi complex plays a central role in protein secretion by regulating cargo sorting and trafficking. As these processes are of functional importance to cell polarity, motility, growth, and division, there is considerable interest in achieving a comprehensive understanding of Golgi complex biology. However, the unique stack structure of this organelle has been a major hurdle to our understanding of how proteins are secreted through the Golgi apparatus. Herein, we summarize available relevant research to gain an understanding of protein secretion via the Golgi complex. This includes the molecular mechanisms of intra-Golgi trafficking and cargo export in the trans-Golgi network. Moreover, we review recent insights on signaling pathways regulated by the Golgi complex and their physiological significance.     

Insulin responsiveness of glucose transporter 4 in 3T3-L1 cells depends on the presence of sortilin

Insulin-dependent translocation of glucose transporter 4 (Glut4) to the plasma membrane of fat and skeletal muscle cells plays the key role in postprandial clearance of blood glucose. Glut4 represents the major cell-specific component of the insulin-responsive vesicles (IRVs). It is not clear, however, whether the presence of Glut4 in the IRVs is essential for their ability to respond to insulin stimulation. We prepared two lines of 3T3-L1 cells with low and high expression of myc₇-Glut4 and studied its translocation to the plasma membrane upon insulin stimulation, using fluorescence-assisted cell sorting and cell surface biotinylation. In undifferentiated 3T3-L1 preadipocytes, translocation of myc₇-Glut4 was low regardless of its expression levels. Coexpression of sortilin increased targeting of myc₇-Glut4 to the IRVs, and its insulin responsiveness rose to the maximal levels observed in fully differentiated adipocytes. Sortilin ectopically expressed in undifferentiated cells was translocated to the plasma membrane regardless of the presence or absence of myc₇-Glut4. AS160/TBC1D4 is expressed at low levels in preadipocytes but is induced in differentiation and provides an additional mechanism for the intracellular retention and insulin-stimulated release of Glut4.Adipocytes, skeletal muscle cells, and some neurons respond to insulin stimulation by translocating intracellular glucose transporter 4 (Glut4) to the plasma membrane. In all these cells, the insulin-responsive pool of Glut4 is localized in small membrane vesicles, the insulin-responsive vesicles (IRVs; Kandror and Pilch, 2011 ; Bogan, 2012 ). The protein composition of these vesicles has been largely characterized (Kandror and Pilch, 2011 ; Bogan, 2012 ). The IRVs consist predominantly of Glut4, insulin-responsive aminopeptidase (IRAP), sortilin, low-density-lipoprotein receptor–related protein 1 (LRP1), SCAMPs, and VAMP2. Glut4, IRAP, and sortilin physically interact with each other, which might be important for the biogenesis of the IRVs (Shi and Kandror, 2007 ; Shi et al., 2008 ). In addition, the IRVs compartmentalize recycling receptors, such as the transferrin receptor and the IGF2/mannose 6-phosphate receptor, although it is not clear whether these receptors represent obligatory vesicular components or their presence in the IRVs is explained by mass action (Pilch, 2008 ), inefficient sorting, or other reasons.Deciphering of the protein composition of the IRVs is important because it is likely to explain their unique functional property: translocation to the plasma membrane in response to insulin stimulation. Even if we presume that IRV trafficking is controlled by loosely associated peripheral membrane proteins, the latter should still somehow recognize the core vesicular components that create the “biochemical individuality” of this compartment. In spite of our knowledge of the IRV protein composition, however, the identity of the protein(s) that confer insulin sensitivity to these vesicles is unknown.Insulin responsiveness of the IRVs was associated with either IRAP or Glut4. Thus it was shown that Glut4 interacted with the intracellular anchor TUG (Bogan et al., 2003 , 2012 ), whereas IRAP associated with other proteins implemented in the regulation of Glut4 translocation, such as AS160 (Larance et al., 2005 ; Peck et al., 2006 ), p115 (Hosaka et al., 2005 ), tankyrase (Yeh et al., 2007 ), and several others (reviewed in Bogan, 2012 ). Results of these studies, or at least their interpretations, are not necessarily consistent with each other, as the existence of multiple independent anchors for the IRVs is, although possible, unlikely.Ablation of the individual IRV proteins has also led to controversial data. Thus knockout of IRAP decreases total protein levels of Glut4 but does not affect its translocation in the mouse model (Keller et al., 2002 ). On the contrary, knockdown of IRAP in 3T3-L1 adipocytes has a strong inhibitory effect on translocation of Glut4 (Yeh et al., 2007 ). In yet another study, knockdown of IRAP in 3T3-L1 adipocytes did not affect insulin-stimulated translocation of Glut4 but increased its plasma membrane content under basal conditions (Jordens et al., 2010 ). By the same token, total or partial ablation of Glut4 had various effects on expression levels, intracellular localization, and translocation of IRAP (Jiang et al., 2001 ; Abel et al., 2004 ; Carvalho et al., 2004 ; Gross et al., 2004 ; Yeh et al., 2007 ). Knockdown of either sortilin or LRP1 decreased protein levels of Glut4 (Shi and Kandror, 2005 ; Jedrychowski et al., 2010 ).One model that might explain these complicated and somewhat inconsistent results is that depletion of either major integral protein of the IRVs disrupts the network of interactions between vesicular proteins and thus decreases the efficiency of protein sorting into the IRVs (Kandror and Pilch, 2011 ). Correspondingly, the remaining IRV components that cannot be faithfully compartmentalized in the vesicles are either degraded (Jiang et al., 2001 ; Keller et al., 2002 ; Abel et al., 2004 ; Carvalho et al., 2004 ; Shi and Kandror, 2005 ; Yeh et al., 2007 ; Jedrychowski et al., 2010 ) or mistargeted (Jiang et al., 2001 ; Jordens et al., 2010 ), depending on experimental conditions and types of cells used in these studies. In other words, knockdown of any major IRV component may decrease vesicle formation along with insulin responsiveness. Thus, in spite of a large body of literature, the identity of protein(s) that confer insulin responsiveness to the IRVs is unknown.Here we used a gain-of-function approach to address this question. Specifically, we attempted to “build” functional IRVs in undifferentiated 3T3-L1 preadipocytes by forced expression of the relevant proteins. Undifferentiated preadipocytes do not express Glut4 or sortilin and lack IRVs (ElJack et al., 1999 ; Shi and Kandror, 2005 ; Shi et al., 2008 ). Correspondingly, IRAP, which is expressed in these cells, shows low insulin response (Ross et al., 1998 ; Shi et al., 2008 ). We found that ectopic expression of increasing amounts of Glut4 in undifferentiated preadipocytes does not lead to its marked translocation to the plasma membrane upon insulin stimulation. On the contrary, sortilin expressed in undifferentiated preadipocytes was localized in the IRVs and was translocated to the plasma membrane in response to insulin stimulation. Moreover, upon coexpression with Glut4, sortilin dramatically increased its insulin responsiveness to the levels observed in fully differentiated adipocytes. Thus sortilin may represent the key component of the IRVs, which is responsible not only for the formation of vesicles (Shi and Kandror, 2005 ; Ariga et al., 2008 ; Hatakeyama and Kanzaki, 2011 ), but also for their insulin responsiveness. It is worth noting that sortilin levels are significantly decreased in obese and diabetic humans and mice (Kaddai et al., 2009 ). We thus suggest that sortilin may be a novel and important target in the fight against insulin resistance and diabetes.Our experiments also demonstrate that undifferentiated preadipocytes lack a mechanism for the full intracellular retention of Glut4 that can be achieved by ectopic expression of AS160/TBC1D4.