Pseudomonas aeruginosa outer membrane vesicle-packed sRNAs can enter host cells and regulate innate immune responses.

Bacterial outer membrane vesicles (OMVs) can package and deliver virulence factors into host cells, which is an important mechanism mediating host-pathogen interactions. It has been reported that small RNAs (sRNAs) can be packed into OMVs with varying relative abundance, which might affect the function and/or stability of host mRNAs. In this study, we used OptiPrep density gradient ultra-high-speed centrifugation to purify OMVs from Pseudomonas aeruginosa. Next, the sequences and abundance of sRNAs were detected by using Small RNA-Seq. In particular, sRNA4518698, sRNA2316613 and sRNA809738 were the three most abundant sRNAs in OMVs, which are all fragments of P. aeruginosa non-coding RNAs. sRNAs were shielded within the interior of OMVs and remained resistant to external RNase cleavage. The miRanda and RNAhybrid analysis demonstrated that those sRNAs could target a large number of host mRNAs, which were enriched in host immune responses by the functions of GO and KEGG enrichment. Experimentally, we demonstrated that the transfection of synthetic sRNA4518698, sRNA2316613, or sRNA809738 could reduce the expression of innate immune response genes in RAW264.7 cells. Together, we demonstrated that P. aeruginosa OMVs sRNAs can regulate innate immune responses. This study uncovered a mechanism in which the OMVs regulate host responses by transferring bacterial sRNAs.

Short-term continuous monocropping reduces peanut yield mainly via altering soil enzyme activity and fungal community.

Continuous monocropping can lead to soil sickness and increase of soil-borne disease, which finally reduces crop yield. Microorganisms benefit plants by increasing nutrient availability, participating in auxin synthesis, and defending against pathogens. However, little is known about the influence of short-term successive peanuts cropping on soil properties, enzyme activities, its yield, plant-associated microbes, and their potential correlations in peanut production. Here, we examined the community structure, composition, network structure and function of microbes in the rhizosphere and bulk soils under different monocropping years. Moreover, we assessed the impact of changes in the soil micro-environment and associated soil microbes on peanut yield. Our results showed that increase of monocropping year significantly decreased most soil properties, enzyme activities and peanut yield (p < 0.05). Principal co-ordinates analysis (PCoA) and analysis of similarities (ANOSIM) indicated that monocropping year significantly influenced the fungal community structure in the rhizosphere and bulk soils (p < 0.01), while had no effect on the bacterial community. With the increase of continuous monocropping year, peanut selectively decreased (e.g., Candidatus_Entotheonella, Bacillus and Bryobacter) or increased (e.g., Nitrospira, Nocardioides, Ensifer, Gaiella, and Novosphingobium) the abundance of some beneficial bacterial genera in the rhizosphere. Continuous monocropping significantly increased the abundance of plant pathogens (e.g., Plectosphaerella, Colletotrichum, Lectera, Gibberella, Metarhizium, and Microdochium) in the rhizosphere and negatively affected the balance of fungal community. Besides, these species were correlated negatively with L-leucine aminopeptidase (LAP) activity. Network co-occurrence analysis showed that continuous monocropping simplified the interaction network of bacteria and fungi. Random forest and partial least squares path modeling (PLS-PM) analysis further showed that fungal community, pathogen abundance, soil pH, and LAP activity negatively affected peanut yield. In conclusion, short-term continuous monocropping decreased LAP activity and increased potential fungal pathogens abundance, leading to reduction of peanut yield.

T6SS translocates a micropeptide to suppress STING-mediated innate immunity by sequestering manganese.

Cellular ionic concentrations are a central factor orchestrating host innate immunity, but no pathogenic mechanism that perturbs host innate immunity by directly targeting metal ions has yet been described. Here, we report a unique virulence strategy of Yersinia pseudotuberculosis (Yptb) involving modulation of the availability of Mn2+, an immunostimulatory metal ion in host cells. We showed that the Yptb type VI secretion system (T6SS) delivered a micropeptide, TssS, into host cells to enhance its virulence. The mutant strain lacking TssS (ΔtssS) showed substantially reduced virulence but induced a significantly stronger host innate immune response, indicating an antagonistic role of this effector in host antimicrobial immunity. Subsequent studies revealed that TssS is a Mn2+-chelating protein and that its Mn2+-chelating ability is essential for the disruption of host innate immunity. Moreover, we showed that Mn2+ enhances the host innate immune response to Yptb infection by activating the stimulator of interferon genes (STING)-mediated immune response. Furthermore, we demonstrated that TssS counteracted the cytoplasmic Mn2+ increase to inhibit the STING-mediated innate immune response by sequestering Mn2+ Finally, TssS-mediated STING inhibition sabotaged bacterial clearance in vivo. These results reveal a previously unrecognized bacterial immune evasion strategy involving modulation of the bioavailability of intracellular metal ions and provide a perspective on the role of the T6SS in pathogenesis.

Decoupling livestock and poultry pollution emissions from industrial development: A step towards reducing environmental emissions.

China has implemented policies like Leading areas for Agricultural Green Development (LAGD) to mitigate livestock and poultry farming pollution while promoting industry growth. However, it remains uncertain whether LAGDs have successfully balanced emission reduction with stable development. This study examines 165 LAGDs to analyze changes in emissions, assess the decoupling of emission reduction from output value, and identify influencing factors. Findings reveal that emissions from livestock and poultry in LAGDs initially increased and then decreased between 2010 and 2019. Cattle were responsible for over 40% of fecal emissions, and pigs for more than 20%. Additionally, pigs contributed to over 61% of urine emissions. From 2010 to 2014, increases in chemical oxygen demand were mainly due to pigs and cattle. Total nitrogen levels were significantly impacted by cattle, while pigs were affected by total phosphorus. From 2014 to 2019, reductions in emissions were largely attributed to a decrease in pig-related pollutants. The decoupling status shifted from strong to weak and then back to strong between 2014 and 2019. Production efficiency played a crucial role in reducing emissions, while changes in industrial structure moved from supporting to hindering this reduction. Economic development was a primary factor in driving these changes. Standard emissions in Chinese regions showed a rising and then declining trend from 2010 to 2019. The Northeast and Northwest regions of China demonstrated emission trends that were in sync with the growth in rural income. This study offers insights into the successes and challenges of LAGDs in achieving a balance between reduced emissions and development, using quantitative analysis. The findings are instrumental in informing policies for a sustainable livestock and poultry industry. Recommendations include evaluating coordinated approaches to pollution reduction and industrial growth, setting decoupling goals, designing policies based on influential factors, conducting regional assessments of livestock and poultry demand, and implementing region-specific strategies.

Feasibility of repairing skin defects by VEGF165 gene-modified iPS-HFSCs seeded on a 3D printed scaffold containing astragalus polysaccharide.

The preparation of biodegradable scaffolds loaded with cells and cytokine is a feature of tissue-engineered skin. IPSCs-based tissue-engineered skin treatment for wound repair is worth exploring. Healthy human skin fibroblasts were collected and reprogrammed into iPSCs. After gene modification and induction, CK19+ /Integrinß1+ /CD200+ VEGF165 gene-modified iPS-HFSCsGFP were obtained and identified by a combination of immunofluorescence and RT-qPCR. Astragalus polysaccharide-containing 3D printed degradable scaffolds were prepared and co-cultured with VEGF165 gene-modified iPS-HFSCsGFP , and the biocompatibility and spatial structure of the tissue-engineered skin was analysed by cell counting kit-8 (CCK8) assay and scanning electron microscopy. Finally, the tissue-engineered skin was transplanted onto the dorsal trauma of nude mice, and the effect of tissue-engineered skin on the regenerative repair of total skin defects was evaluated by a combination of histology, immunohistochemistry, immunofluorescence, RT-qPCR, and in vivo three-dimensional reconstruction under two-photon microscopy. CK19+ /Integrinß1+ /CD200+ VEGF165 gene-modified iPS-HFSCsGFP , close to the morphology and phenotype of human-derived hair follicle stem cells, were obtained. The surface of the prepared 3D printed degradable scaffold containing 200 µg/mL astragalus polysaccharide was enriched with honeycomb-like meshwork, which was more conducive to the proliferation of the resulting cells. After tissue-engineered skin transplantation, combined assays showed that it promoted early vascularization, collagen and hair follicle regeneration and accelerated wound repair. VEGF165 gene-modified iPS-HFSCsGFP compounded with 3D printed degradable scaffolds containing 200 µg/mL astragalus polysaccharide can directly and indirectly participate in vascular, collagen, and hair follicle regeneration in the skin, achieving more complete structural and functional skin regenerative repair.

A pipeline for sample tagging of whole genome bisulfite sequencing data using genotypes of whole genome sequencing.

BACKGROUND: In large-scale high-throughput sequencing projects and biobank construction, sample tagging is essential to prevent sample mix-ups. Despite the availability of fingerprint panels for DNA data, little research has been conducted on sample tagging of whole genome bisulfite sequencing (WGBS) data. This study aims to construct a pipeline and identify applicable fingerprint panels to address this problem. RESULTS: Using autosome-wide A/T polymorphic single nucleotide variants (SNVs) obtained from whole genome sequencing (WGS) and WGBS of individuals from the Third China National Stroke Registry, we designed a fingerprint panel and constructed an optimized pipeline for tagging WGBS data. This pipeline used Bis-SNP to call genotypes from the WGBS data, and optimized genotype comparison by eliminating wildtype homozygous and missing genotypes, and retaining variants with identical genomic coordinates and reference/alternative alleles. WGS-based and WGBS-based genotypes called from identical or different samples were extensively compared using hap.py. In the first batch of 94 samples, the genotype consistency rates were between 71.01%-84.23% and 51.43%-60.50% for the matched and mismatched WGS and WGBS data using the autosome-wide A/T polymorphic SNV panel. This capability to tag WGBS data was validated among the second batch of 240 samples, with genotype consistency rates ranging from 70.61%-84.65% to 49.58%-61.42% for the matched and mismatched data, respectively. We also determined that the number of genetic variants required to correctly tag WGBS data was on the order of thousands through testing six fingerprint panels with different orders for the number of variants. Additionally, we affirmed this result with two self-designed panels of 1351 and 1278 SNVs, respectively. Furthermore, this study confirmed that using the number of genetic variants with identical coordinates and ref/alt alleles, or identical genotypes could not correctly tag WGBS data. CONCLUSION: This study proposed an optimized pipeline, applicable fingerprint panels, and a lower boundary for the number of fingerprint genetic variants needed for correct sample tagging of WGBS data, which are valuable for tagging WGBS data and integrating multi-omics data for biobanks.

The potential bias of nitrogen deposition effects on primary productivity and biodiversity.

Atmospheric nitrogen (N) deposition is composed of both inorganic nitrogen (IN) and organic nitrogen (ON), and these sources of N may exhibit different impacts on ecosystems. However, our understanding of the impacts of N deposition is largely based on experimental gradients of INs or more rarely ONs. Thus, the effects of N deposition on ecosystem productivity and biodiversity may be biased. We explored the differential impacts of N addition with different IN:ON ratios (0:10, 3:7, 5:5, 7:3, and 10:0) on aboveground net primary productivity (ANPP) of plant community and plant diversity in a typical temperate grassland with a long-term N addition experiment. Soil pH, litter biomass, soil IN concentration, and light penetration were measured to examine the potential mechanisms underlying species loss with N addition. Our results showed that N addition significantly increased plant community ANPP by 68.33%-105.50% and reduced species richness by 16.20%-37.99%. The IN:ON ratios showed no significant effects on plant community ANPP. However, IN-induced species richness loss was about 2.34 times of ON-induced richness loss. Soil pH was positively related to species richness, and they exhibited very similar response patterns to IN:ON ratios. It implies that soil acidification accounts for the different magnitudes of species loss with IN and ON additions. Overall, our study suggests that it might be reasonable to evaluate the effects of N deposition on plant community ANPP with either IN or ON addition. However, the evaluation of N deposition on biodiversity might be overestimated if only IN is added or underestimated if only ON is added.

Peanut-based Rotation Stabilized Diazotrophic Communities and Increased Subsequent Wheat Yield.

The introduction of legumes into rotations can improve nitrogen use efficiency and crop yield; however, its microbial mechanism involved remains unclear. This study aimed to explore the temporal impact of peanut introduction on microorganisms related to nitrogen metabolism in rotation systems. In this study, the dynamics of diazotrophic communities in two crop seasons and wheat yields of two rotation systems: winter wheat - summer maize (WM) and spring peanut → winter wheat - summer maize (PWM) in the North China Plain were investigated. Our results showed that peanut introduction increased wheat yield and biomass by 11.6% (p < 0.05) and 8.9%, respectively. Lower Chao1 and Shannon indexes of the diazotrophic communities were detected in soils that sampling in June compared with those sampling in September, although no difference was found between WM and PWM. Principal co-ordinates analysis (PCoA) showed that rotation system significantly changed the diazotrophic community structures (PERMANOVA; p < 0.05). Compared with WM, the genera of Azotobacter, Skermanella, Azohydromonas, Rhodomicrobium, Azospirillum, Unclassified_f_Opitutaceae, and Unclassified_f_Rhodospirillaceae were significantly enriched (p < 0.05) in PWM. Furthermore, rotation system and sampling time significantly influenced soil properties, which significantly correlated with the top 15 genera in relative abundance. Partial least squares path modeling (PLS-PM) analysis further showed that the diazotrophic community diversity (alpha- and beta-diversity) and soil properties (pH, SOC and TN) significantly affected wheat yield. In conclusion, legume inclusion has the potential to stabilize diazotrophic community structure at the temporal scales and increase subsequent crop yield.

Replacing chemical fertilizer with manure reduces N2O emissions in winter wheat - summer maize cropping system under limited irrigation.

Nitrous oxide (N2O) emissions from agroecosystems are a major contributor to global warming and stratospheric ozone depletion. However, knowledge concerning the hotspots and hot moments of soil N2O emissions with manure application and irrigation, as well as the underlying mechanisms remain incomplete. Here, a 3-year field experiment was conducted with the combination of fertilization (no fertilizer, F0; 100% chemical fertilizer N, Fc; 50% chemical N + 50% manure N, Fc + m; and 100% manure N, Fm) and irrigation (with irrigation, W1; and without irrigation, W0; at wheat jointing stage) for winter wheat - summer maize cropping system in the North China Plain. Results showed that irrigation did not affect annual N2O emissions of the wheat-maize system. Manure application (Fc + m and Fm) reduced annual N2O emissions by 25-51% compared with Fc, which mainly occurred during 2 weeks after fertilization combined with irrigation (or heavy rainfall). In particular, Fc + m reduced the cumulative N2O emissions during 2 weeks after winter wheat sowing and summer maize top dressing by 0.28 and 0.11 kg ha-1, respectively, compared with Fc. Meanwhile, Fm maintained the grain N yield and Fc + m increased grain N yield by 8% compared with Fc under W1. Overall, Fm maintained the annual grain N yield and lower N2O emissions compared to Fc under W0, and Fc + m increased the annual grain N yield and maintained N2O emissions compared with Fc under W1, respectively. Our results provide scientific support for using manure to minimize N2O emissions while maintaining crop N yield under optimal irrigation to support the green transition in agricultural production.

Stereochemistry of Chiral 2-Substituted Chromanes: Twist of the Dihydropyran Ring and Specific Optical Rotation.

Chiral 2-substituted chromanes are important substructures in organic synthesis and appear in numerous natural products. Herein, the correlation between specific optical rotations (SORs) and the stereochemistry at C2 of chiral 2-substituted chromanes was investigated through data mining, quantum-chemical calculations using density functional theory (DFT), and mechanistic analyses. For 2-aliphatic (including acyloxy and alkenyl) chromanes, the P-helicity of the dihydropyran ring usually corresponds to a positive SOR; however, 2-aryl chromanes with P-helicity tend to exhibit negative SORs. 2-Carboxyl (including alkoxycarbonyl and carbonyl) chromanes often display small experimental SORs, and theoretical calculations for them are prone to error because of the fluctuating conformational distribution with computational parameters. Several typical compounds were discussed, including detailed descriptions of the asymmetric synthesis, absolute configuration (AC) assignment methods, and systematic conformational analysis. We hope this work will enrich the knowledge of the stereochemistry of chiral 2-substituted chromanes.

Platform-independent approach for cancer detection from gene expression profiles of peripheral blood cells.

Peripheral blood gene expression intensity-based methods for distinguishing healthy individuals from cancer patients are limited by sensitivity to batch effects and data normalization and variability between expression profiling assays. To improve the robustness and precision of blood gene expression-based tumour detection, it is necessary to perform molecular diagnostic tests using a more stable approach. Taking breast cancer as an example, we propose a machine learning-based framework that distinguishes breast cancer patients from healthy subjects by pairwise rank transformation of gene expression intensity in each sample. We showed the diagnostic potential of the method by performing RNA-seq for 37 peripheral blood samples from breast cancer patients and by collecting RNA-seq data from healthy donors in Genotype-Tissue Expression project and microarray mRNA expression datasets in Gene Expression Omnibus. The framework was insensitive to experimental batch effects and data normalization, and it can be simultaneously applied to new sample prediction.

Benzobis(imidazole) derivatives as STAT3 signal inhibitors with antitumor activity.

Polycyclic aromatic systems have been considered good biological probes, but some may also be good scaffolds for drug development. In this study, a series of benzobis(imidazole) derivatives were identified as STAT3 signal inhibitors, among which compound 24 showed significant inhibition of IL-6 induced JAK/STAT3 signalling pathway activation. Moreover, 24 inhibited cancer cell growth and migration, and induced cell apoptosis as well as cycle arrest in human hepatocellular carcinoma cells (HepG2) and oesophageal carcinoma cells (EC109). Compound 24 also displayed obvious antitumor activity in a mouse HepG2 cell xenograft tumor model without affecting the body weight. These results confirmed that 24 was a potential STAT3 signal inhibitor with certain antitumor activity.

Prognosis and antibody profiles in survivors of critical illness from COVID-19: a prospective multicentre cohort study.

BACKGROUND: There is a need to assess the long-term outcomes of survivors of critical illness from COVID-19. METHODS: Ninety-two survivors of critical illness from COVID-19 from four hospitals in Hubei Province, China participated in this prospective cohort study. Multiple characteristics, including lung function (lung volumes, diffusing capacity for carbon monoxide, chest computed tomography scores, and walking capacity); immune status (SARS-CoV-2-neutralising antibody and all subtypes of immunoglobulin (Ig) G against SARS-CoV-2, immune cells in response to ex vivo antigen peptide stimuli, and lymphocyte count and its subtypes); liver, coagulation, and kidney functions; quality of life; cognitive function; and mental status, were assessed after 3, 6, and 12 months of follow-up. RESULTS: Amongst the 92 enrolled survivors, 72 (78%) patients required mechanical ventilation. At 12 months, the predicted percentage diffusing capacity of lung for carbon monoxide was 82% (inter-quartile range [IQR]: 76-97%) with a residual volume of 77 (64-88)%. Other lung function parameters and the 6-min walk test improved gradually over time and were almost back to normal by 12 months. The titres of IgG and neutralising antibody to COVID-19 remained high at 12 months compared with those of controls who were not infected with COVID-19, although IgG titres decreased significantly from 34.0 (IQR: 23.8-74.3) to 15.0 (5.8-24.3) AU ml-1 (P<0.001), whereas neutralising antibodies decreased from 29.99 (IQR: 19.43-53.93) AU ml-1 at 6 months to 19.75 (13.1-29.8) AU ml-1 (P<0.001) at 12 months. In general, liver, kidney, physical, and mental functions also improved over time. CONCLUSIONS: Survivors of critical illness from COVID-19 show some persistent long-term impairments in lung function. However, a majority of these tests were normal by 12 months. These patients still had detectable levels of neutralising antibodies against SARS-CoV-2 and all types of IgG at 12 months, but the levels had declined over this time period. CLINICAL TRIAL REGISTRATION: None.

A nonneglectable stereochemical factor in drug development: Atropisomerism.

Chirality is one of the key factors affecting the medicinal efficacy of compounds. In addition to central chirality, sterically hindered chiral axes commonly appear in drugs and the resulting chirality is known as atropisomerism. With developments in medicinal chemistry, atropisomerism has attracted increasing attention. This review discusses the classification, biological activity, pharmacokinetics, toxicity and side effects of atropisomers, and can serve as a reference in the research and development of potential chiral drugs.

Effects of highly selective sensory/motor nerve injury on bone metabolism and bone remodeling in rats.

OBJECTIVES: This work aimed to investigate the mechanism of selective sensory/motor nerve injury in affecting bone metabolism and remodeling. METHODS: The selective sensory/motor nerve injury rat model was constructed through posterior rhizotomy (PRG), anterior rhizotomy (ARG), or anterior combined with posterior rhizotomy (APRG) at the L4-6 sensory/motor nerves on the right side of rats. Sham-operated (SOG) rats served as control. At 8 weeks after surgery, the sciatic nerves, spinal cord segments L5 and tibial tissues were collected for analysis. RESULTS: the integrity of trabecular bone was damaged, the number of trabecular bone was decreased and the number of osteoclasts were increased in ARG group. ARG activated NF-κß and PPAR-γ pathways, and inhibited Wnt/ß-catenin pathway. ARG group exhibited high turnover bone metabolism. In PRG group, the trabecular bone morphology became thinner, and the number of osteoclasts was increased. NF-κß pathway was activated and OPG/RANKL ratio was decreased in PRG group. The activated osteoclasts, reduced osteoblasts activity and lower turnover bone metabolism were observed in PRG group. Additionally, the bone metabolism in APRG group was similar to ARG group. CONCLUSION: The posterior rhizotomy and anterior rhizotomy induced the different degree of osteoporosis in rats, which may attribute to regulate Wnt/ß-catenin, NF-κß and PPAR-γ signalling pathways.

Correlations between the ECD spectra and absolute configuration of bridged-ring lactones: revisiting Beecham's rule.

Bridged lactones frequently appear as structural fragments in natural products. To elucidate their stereochemistry using electronic circular dichroism (ECD) spectra, Beecham correlated the sign of the Cotton effect (CE) from the n → π* transition of lactones at approximately 220 nm with the skeleton of bridged lactones. By combining experimental and theoretical ECD analyses of various bridged lactones using time-dependent density functional theory calculations and a methodology for extracting core structures, Beecham's rule was revisited and revised to define the scope of application. Both the position of the ß-C atom in the larger lactone system and the additive contribution of groups at ß-C exerted effects on the sign of the CE. The revised rule provides an alternative way to interpret experimental ECD data in addition to quantum-chemical calculation for various bridged lactones.

Cometabolic degradation of 1,4-dioxane by a tetrahydrofuran-growing Arthrobacter sp. WN18.

1,4-Dioxane (dioxane), an emerging groundwater contaminant, is frequently detected in landfill leachates with its structural analog, tetrahydrofuran (THF). Along with undesirable leakage of landfill leachates, dioxane and THF inevitably percolate into groundwater leading to a broader region of contamination. Cometabolic bioremediation is an effective approach to manage commingled THF and dioxane pollution. In this study, a newly isolated bacterium Arthrobacter sp. WN18 is able to co-oxidize dioxane with THF as the primary substrate. Meanwhile, the THF-induced thmADBC gene cluster was responsible for the dioxane degradation rate indicating THF monooxygenase is the essential enzyme that initializing α-hydroxylation of THF and dioxane. Further, γ-butyrolactone and HEAA were characterized as the key metabolites of THF and dioxane, respectively. In addition, WN18 can tolerate the inhibition of trichloroethylene (5.0 mg/L) as a representative of co-existing leachate constituent, and sustain its activity at various pH (5-11), temperatures (15-42 °C), and salinities (up to 4%, as NaCl wt). Like other Arthrobacter species, WN18 also exhibited the capability of fixing nitrogen. All this evidence indicates the feasibility and advantage of WN18 as a thmADBC-catalyzed inoculator to bioremediate co-contamination of THF and dioxane.

Analysis of clinical features and outcomes of 161 patients with severe and critical COVID-19: A multicenter descriptive study.

BACKGROUND: This study aimed to investigate clinical characteristics, laboratory indexes, treatment regimens, and short-term outcomes of severe and critical coronavirus disease 2019 (COVID-19) patients. METHODS: One hundred and sixty one consecutive severe and critical COVID-19 patients admitted in intensive care unit (ICU) were retrospectively reviewed in this multicenter study. Demographic features, medical histories, clinical symptoms, lung computerized tomography (CT) findings, and laboratory indexes on admission were collected. Post-admission complications, treatment regimens, and clinical outcomes were also documented. RESULTS: The mean age was 59.38 ± 16.54 years, with 104 (64.60%) males and 57 (35.40%) females. Hypertension (44 [27.33%]) and diabetes were the most common medical histories. Fever (127 [78.88%]) and dry cough (111 [68.94%]) were the most common symptoms. Blood routine indexes, hepatic and renal function indexes, and inflammation indexes were commonly abnormal. Acute respiratory distress syndrome (ARDS) was the most common post-admission complication (69 [42.86%]), followed by electrolyte disorders (48 [29.81%]), multiple organ dysfunction (MODS) (37 [22.98%]), and hypoproteinemia (36 [22.36%]). The most commonly used antiviral drug was lopinavir/ritonavir tablet. 50 (31.06%) patients died, while 78 (48.45%) patients healed and discharged, and the last 33 (20.50%) patients remained in hospital. Besides, the mean hospital stay of deaths was 21.66 ± 11.18 days, while the mean hospital stay of discharged patients was 18.42 ± 12.77 days. Furthermore, ARDS (P < .001) and MODS (P = .008) correlated with increased mortality rate. CONCLUSION: Severe and critical COVID-19 presents with high mortality rate, and occurrence of ARDS or MODS greatly increases its mortality risk.

microRNA-25 promotes cardiomyocytes proliferation and migration via targeting Bim.

microRNAs (miRNAs) are pleiotropic players in cardiac development. Recent evidence have suggested miRNAs as promisingly therapeutic targets for cardiac regeneration. This study aimed to reveal the potential effects of miR-25 on cardiomyocytes proliferation and migration. Sprague-Dawley rats received left coronary occlusion surgery to induce an in vivo model of myocardial ischemia/reperfusion (I/R) injury. Expression changes of miR-25 and Bim were tested by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blot. Besides, primary neonatal and adult cardiomyocytes were transfected by the antisense oligonucleotides or mimic specific for miR-25, and then 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Boyden chamber, and terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay were respectively used to determine cardiomyocytes growth and migration. Binding effects of miR-25 on the 3'-untranslated region (3'-UTR) of Bim was assessed by dual-luciferase reporter assay. We found that miR-25 was low expressed, whereas Bim was highly expressed in I/R injury model and hypoxia-stimulated cardiomyocytes. Downregulation of miR-25 in neonatal and adult cardiomyocytes markedly reduced cell proliferation and migration, but promoted apoptosis. Consistently, downregulation of miR-25 decreased the expression of cyclin E2, cyclin D1, and CDK4, and increased the expression of p57 (KIP2) in cardiomyocytes. We additionally found that Bim was a target of miR-25. The inhibitory effects of miR-25 downregulation on cardiomyocytes survival and migration were all significantly attenuated when Bim was silenced. To sum up, our study demonstrates that miR-25 downregulation inhibits cardiomyocytes proliferation and migration, but promotes apoptosis. The role of miR-25 in cardiomyocytes was by targeting Bim.

The impact of sseK2 deletion on Salmonella enterica serovar typhimurium virulence in vivo and in vitro.

BACKGROUND: Salmonella enterica is regarded as a major public health threat worldwide. Salmonella secretes the novel translocated effector protein K2 (SseK2), but it is unclear whether this protein plays a significant role in Salmonella enterica Typhimurium virulence. RESULTS: A ΔsseK2 mutant of S. Typhimurium exhibited similar growth curves, adhesion and invasive ability compared with wild-type (WT) bacteria. However, deletion of sseK2 rendered Salmonella deficient in biofilm formation and the early proliferative capacity of the ΔsseK2 mutant was significantly lower than that of the WT strain. In vivo, the LD50 (median lethal dose) of the ΔsseK2 mutant strain was increased 1.62 × 103-fold compared with the WT strain. In addition, vaccinating mice with the ΔsseK2 mutant protected them against challenge with a lethal dose of the WT strain. The ability of the ΔsseK2 mutant strain to induce systemic infection was highly attenuated compared with the WT strain, and the bacterial load in the animals' internal organs was lower when they were infected with the ΔsseK2 mutant strain than when they were infected with the WT strain. CONCLUSIONS: We conclude that sseK2 is a virulence-associated gene that plays a vital role in Salmonella virulence.