COVID-19 induces more pronounced extracellular matrix deposition than other causes of ARDS.

BACKGROUND: Lung fibrosis is a major concern in severe COVID-19 patients undergoing mechanical ventilation (MV). Lung fibrosis frequency in post-COVID syndrome is highly variable and even if the risk is proportionally small, many patients could be affected. However, there is still no data on lung extracellular matrix (ECM) composition in severe COVID-19 and whether it is different from other aetiologies of ARDS. METHODS: We have quantified different ECM elements and TGF-ß expression in lung tissue of 28 fatal COVID-19 cases and compared to 27 patients that died of other causes of ARDS, divided according to MV duration (up to six days or seven days or more). In COVID-19 cases, ECM elements were correlated with lung transcriptomics and cytokines profile. RESULTS: We observed that COVID-19 cases presented significant increased deposition of collagen, fibronectin, versican, and TGF-ß, and decreased decorin density when compared to non-COVID-19 cases of similar MV duration. TGF-ß was precociously increased in COVID-19 patients with MV duration up to six days. Lung collagen was higher in women with COVID-19, with a transition of upregulated genes related to fibrillogenesis to collagen production and ECM disassembly along the MV course. CONCLUSIONS: Fatal COVID-19 is associated with an early TGF-ß expression lung environment after the MV onset, followed by a disordered ECM assembly. This uncontrolled process resulted in a prominent collagen deposition when compared to other causes of ARDS. Our data provides pathological substrates to better understand the high prevalence of pulmonary abnormalities in patients surviving COVID-19.

Genome-resolved metagenome and metatranscriptome analyses of thermophilic composting reveal key bacterial players and their metabolic interactions.

BACKGROUND: Composting is an important technique for environment-friendly degradation of organic material, and is a microbe-driven process. Previous metagenomic studies of composting have presented a general description of the taxonomic and functional diversity of its microbial populations, but they have lacked more specific information on the key organisms that are active during the process. RESULTS: Here we present and analyze 60 mostly high-quality metagenome-assembled genomes (MAGs) recovered from time-series samples of two thermophilic composting cells, of which 47 are potentially new bacterial species; 24 of those did not have any hits in two public MAG datasets at the 95% average nucleotide identity level. Analyses of gene content and expressed functions based on metatranscriptome data for one of the cells grouped the MAGs in three clusters along the 99-day composting process. By applying metabolic modeling methods, we were able to predict metabolic dependencies between MAGs. These models indicate the importance of coadjuvant bacteria that do not carry out lignocellulose degradation but may contribute to the management of reactive oxygen species and with enzymes that increase bioenergetic efficiency in composting, such as hydrogenases and N2O reductase. Strong metabolic dependencies predicted between MAGs revealed key interactions relying on exchange of H+, NH3, O2 and CO2, as well as glucose, glutamate, succinate, fumarate and others, highlighting the importance of functional stratification and syntrophic interactions during biomass conversion. Our model includes 22 out of 49 MAGs recovered from one composting cell data. Based on this model we highlight that Rhodothermus marinus, Thermobispora bispora and a novel Gammaproteobacterium are dominant players in chemolithotrophic metabolism and cross-feeding interactions. CONCLUSIONS: The results obtained expand our knowledge of the taxonomic and functional diversity of composting bacteria and provide a model of their dynamic metabolic interactions.

MJD and OTU deubiquitinating enzymes in Schistosoma mansoni.

The ubiquitination and deubiquitination of proteins can alter diverse cellular processes, such as proteolysis, trafficking, subcellular localisation, DNA repair, apoptosis and signal transduction. Deubiquitinating enzymes (DUBs) are responsible for removing ubiquitin from their target proteins. Previous reports have shown the presence of two subfamilies of DUBs in Schistosoma mansoni: Ub carboxyl-terminal hydrolase (UCH) and Ub-specific protease (USP). In this study, we analysed the ovarian tumour (OTU) and Machado-Joseph disease protein domain (MJD) proteases found in the Schistosoma mansoni genome database. An in silico analysis identified two different MJD subfamily members, SmAtaxin-3 and SmJosephin, and five distinct OTU proteases, SmOTU1, SmOTU3, SmOTU5a, SmOTU6b and SmOtubain. The phylogenetic analysis showed the evolutionary conservation of these proteins. Furthermore, the 3D structures confirmed the similarity of these proteins with human proteins. In addition, we performed quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and observed distinct expression profiles for all of the investigated transcripts between the cercariae, schistosomula and adult worm stages. Taken together, our data suggest that MJD and OTU subfamily members contribute to regulating the activity of the Ub-proteasome system during the life cycle of this parasite.

Conservation and developmental expression of ubiquitin isopeptidases in Schistosoma mansoni.

Several genes related to the ubiquitin (Ub)-proteasome pathway, including those coding for proteasome subunits and conjugation enzymes, are differentially expressed during the Schistosoma mansoni life cycle. Although deubiquitinating enzymes have been reported to be negative regulators of protein ubiquitination and shown to play an important role in Ub-dependent processes, little is known about their role in S. mansoni . In this study, we analysed the Ub carboxyl-terminal hydrolase (UCHs) proteins found in the database of the parasite's genome. An in silico ana- lysis (GeneDB and MEROPS) identified three different UCH family members in the genome, Sm UCH-L3, Sm UCH-L5 and Sm BAP-1 and a phylogenetic analysis confirmed the evolutionary conservation of the proteins. We performed quantitative reverse transcription-polymerase chain reaction and observed a differential expression profile for all of the investigated transcripts between the cercariae and adult worm stages. These results were corroborated by low rates of Z-Arg-Leu-Arg-Gly-Gly-AMC hydrolysis in a crude extract obtained from cercariae in parallel with high Ub conjugate levels in the same extracts. We suggest that the accumulation of ubiquitinated proteins in the cercaria and early schistosomulum stages is related to a decrease in 26S proteasome activity. Taken together, our data suggest that UCH family members contribute to regulating the activity of the Ub-proteasome system during the life cycle of this parasite.

Computational identification and evolutionary relationships of the microRNA gene cluster miR-71/2 in protostomes.

MicroRNAs (miRNAs) are small noncoding RNA molecules which are processed into ~20-24 nt molecules that can regulate the gene expression post-transcriptionally. MiRNA gene clusters have been identified in a range of species, where in miRNAs are often processed from polycistronic transcripts. In this study, a computational approach is used to investigate the extent of evolutionary conservation of the miR-71/2 cluster in animals, and to identify novel miRNAs in the miRNA cluster miR-71/2. The miR-71/2 cluster, consisting of copies of the miR-71 and miR-2 (including miR-13) families, was found to be Protostome-specific. Although, this cluster is highly conserved across the Protostomia, the miR-2 family is completely absent from the Deuterostomia species, while miR-71 is absent from the Vertebrata and Urochordata. The evolutionary conservation and clustering propensity of the miR-71/2 family across the Protostomes could indicate the common functional roles across the member species of the Protostomia.

Investigation on the 19S ATPase proteasome subunits (Rpt1-6) conservation and their differential gene expression in Schistosoma mansoni.

The ubiquitin-proteasome system is responsible for degradation of the majority of intracellular proteins in eukaryotic cells. The 26S proteasome proteolytic complex is composed of a 20S core particle responsible for protein degradation and the 19S lid which plays a role in the recognition of polyubiquitinated substrates. The 19S regulatory particle (Rps) is composed of ATPase (Rpt) and non-ATPase (Rpn) subunits. In this study, we analyzed the expression profile of 19S Rpt subunits in the larvae and adult stage of the Schistosoma mansoni life cycle. Conventional reverse transcriptase polymerase chain reaction (RT-PCR) revealed that the majority of the 19S Rpt subunits amplified at the expected molecular masses for various investigated stages. In addition, SmRpt1, SmRpt2, and SmRpt6 transcript levels were increased in 3 h-cultured schistosomula and reasonably maintained until 5 h in culture, as revealed by qRT-PCR. Phylogenetic analysis of 19S Rpt subunits showed high structural conservation in comparison to other Rpt orthologues. The mRNA expression profile of 19S Rpt subunits did not correlate with 26S proteasome proteolytic activity as judged by a (14)C-casein-degrading assay, in the early cultured schistosomula. Taken together, these results revealed a differential expression profile for 19S Rpt subunits whose transcript levels could not be directly associated to 26S proteasome activity.

Molecular characterization of SUMO E2 conjugation enzyme: differential expression profile in Schistosoma mansoni.

SUMO-dependent post-translational modification is implicated in a variety of cellular functions including gene expression regulation, nuclear sub-localization, and signal transduction. Conjugation of SUMO to other proteins occurs in a similar process to ubiquitination, which involves three classes of enzymes: an E1 activating, an E2 conjugating, and an E3 target-specific ligase. Ubc9 is the unique SUMO E2 enzyme known to conjugate SUMO to target substrates. Here, we present the molecular characterization of this enzyme and demonstrate its expression profile during the S. mansoni life cycle. We have used bioinformatic approaches to identify the SUMO-conjugating enzyme, the SmUbc9-like protein, in the Schistosoma mansoni databases. Quantitative RT-PCR was employed to measure the transcript levels of SUMO E2 in cercariae, adult worms, and in vitro cultivated schistosomula. Furthermore, recombinant SmUbc9 was expressed using the Gateway system, and antibodies raised in rats were used to measure SmUbc9 protein levels in S. mansoni stages by Western blotting. Our data revealed upregulation of the SmUbc9 transcript in early schistosomula followed by a marked differential gene expression in the other analyzed stages. The protein levels were maintained fairly constant suggesting a post-transcriptional regulation of the SmUbc9 mRNA. Our results show for the first time that S. mansoni employs a functional SUMO E2 enzyme, for the conjugation of the SUMO proteins to its target substrates.

Microbial community structure and dynamics in thermophilic composting viewed through metagenomics and metatranscriptomics.

Composting is a promising source of new organisms and thermostable enzymes that may be helpful in environmental management and industrial processes. Here we present results of metagenomic- and metatranscriptomic-based analyses of a large composting operation in the São Paulo Zoo Park. This composting exhibits a sustained thermophilic profile (50 °C to 75 °C), which seems to preclude fungal activity. The main novelty of our study is the combination of time-series sampling with shotgun DNA, 16S rRNA gene amplicon, and metatranscriptome high-throughput sequencing, enabling an unprecedented detailed view of microbial community structure, dynamics, and function in this ecosystem. The time-series data showed that the turning procedure has a strong impact on the compost microbiota, restoring to a certain extent the population profile seen at the beginning of the process; and that lignocellulosic biomass deconstruction occurs synergistically and sequentially, with hemicellulose being degraded preferentially to cellulose and lignin. Moreover, our sequencing data allowed near-complete genome reconstruction of five bacterial species previously found in biomass-degrading environments and of a novel biodegrading bacterial species, likely a new genus in the order Bacillales. The data and analyses provided are a rich source for additional investigations of thermophilic composting microbiology.

Transcriptional Profile and Structural Conservation of SUMO-Specific Proteases in Schistosoma mansoni.

Small ubiquitin-related modifier (SUMO) is involved in numerous cellular processes including protein localization, transcription, and cell cycle control. SUMOylation is a dynamic process, catalyzed by three SUMO-specific enzymes and reversed by Sentrin/SUMO-specific proteases (SENPs). Here we report the characterization of these proteases in Schistosoma mansoni. Using in silico analysis, we identified two SENPs sequences, orthologs of mammalian SENP1 and SENP7, confirming their identities and conservation through phylogenetic analysis. In addition, the transcript levels of Smsenp1/7 in cercariae, adult worms, and in vitro cultivated schistosomula were measured by qRT-PCR. Our data revealed upregulation of the Smsenp1/7 transcripts in cercariae and early schistosomula, followed by a marked differential gene expression in the other analyzed stages. However, no significant difference in expression profile between the paralogs was observed for the analyzed stages. Furthermore, in order to detect deSUMOylating capabilities in crude parasite extracts, SmSENP1 enzymatic activity was evaluated using SUMO-1-AMC substrate. The endopeptidase activity related to SUMO-1 precursor processing did not differ significantly between cercariae and adult worms. Taken together, these results support the developmentally regulated expression of SUMO-specific proteases in S. mansoni.

Conservation and developmental expression of ubiquitin isopeptidases in Schistosoma mansoni

Several genes related to the ubiquitin (Ub)-proteasome pathway, including those coding for proteasome subunits and conjugation enzymes, are differentially expressed during the Schistosoma mansoni life cycle. Although deubiquitinating enzymes have been reported to be negative regulators of protein ubiquitination and shown to play an important role in Ub-dependent processes, little is known about their role in S. mansoni . In this study, we analysed the Ub carboxyl-terminal hydrolase (UCHs) proteins found in the database of the parasite’s genome. An in silico ana- lysis (GeneDB and MEROPS) identified three different UCH family members in the genome, Sm UCH-L3, Sm UCH-L5 and Sm BAP-1 and a phylogenetic analysis confirmed the evolutionary conservation of the proteins. We performed quantitative reverse transcription-polymerase chain reaction and observed a differential expression profile for all of the investigated transcripts between the cercariae and adult worm stages. These results were corroborated by low rates of Z-Arg-Leu-Arg-Gly-Gly-AMC hydrolysis in a crude extract obtained from cercariae in parallel with high Ub conjugate levels in the same extracts. We suggest that the accumulation of ubiquitinated proteins in the cercaria and early schistosomulum stages is related to a decrease in 26S proteasome activity. Taken together, our data suggest that UCH family members contribute to regulating the activity of the Ub-proteasome system during the life cycle of this parasite.