Evolutionary and ecological forces shape nutrient strategies of mycorrhizal woody plants

The associations of arbuscular mycorrhizal (AM) or ectomycorrhiza (EcM) fungi with plants have sequentially evolved and significantly contributed to enhancing plant nutrition. Nonetheless, how evolutionary and ecological forces drive nutrient acquisition strategies of AM and EcM woody plants remains poorly understood. Our global analysis of woody species revealed that, over divergence time, AM woody plants evolved faster nitrogen mineralization rates without changes in nitrogen resorption. However, EcM woody plants exhibited an increase in nitrogen mineralization but a decrease in nitrogen resorption, indicating a shift towards a more inorganic nutrient economy. Despite this alteration, when evaluating present-day woody species, AM woody plants still display faster nitrogen mineralization and lower nitrogen resorption than EcM woody plants. This inorganic nutrient economy allows AM woody plants to thrive in warm environments with a faster litter decomposition rate. Our findings indicate that the global pattern of nutrient acquisition strategies in mycorrhizal plants is shaped by the interplay between phylogeny and climate.

Histogram analysis of diffusion kurtosis imaging of deep brain nuclei in Parkinson's disease with different motor subtypes

AIM

To evaluate the diagnostic and differential efficacy of diffusion kurtosis imaging (DKI) histogram analysis for different motor subtypes of Parkinson's disease (PD).

MATERIALS AND METHODS

Seventy PD patients including 40 with postural instability and gait disorder (PIGD) and 30 with tremor-dominant (TD) and 36 healthy controls (HC) were enrolled prospectively and underwent MRI examinations. The regions of interest (ROI) in the deep brain nuclei were delineated and features were extracted on the map of mean kurtosis (MK), axial kurtosis (Ka), and radial kurtosis (Kr), respectively. The differences in histogram features between PD patients and HC and between patients with PIGD and TD were compared. The areas under the curve (AUCs) were calculated to evaluate the diagnostic efficacy of all histogram features. The correlations between histogram features and clinical indicators were evaluated.

RESULTS

Some DKI histogram features were significantly different between PD patients and HC, and also different between patients with PIGD and TD (all p<0.05). MK of the substantia nigra pars reticulate (SNprkurtosis), Ka of the substantia nigra pars compacta (SNpc) 50 percentile (SNpcP50), and Kr of SNpc 90th percentile showed the highest AUC for distinguishing patients with PIGD from HC. MK-SNpc 10th percentile, Ka-SNpc 25th percentile, and Kr of the head of the caudate nucleus (CN) 90th percentile had the highest AUC for distinguishing patients with TD from HC. MK of the putamen 10th percentile combined with Ka of the bilateral red nucleus RNkurtosis yielded the highest diagnostic performance with an AUC of 0.762 for distinguishing patients with PIGD from TD. Certain DKI histogram features were correlated with Hoehn-Yahr (H&Y) stage, Mini Mental State Examination (MMSE) score, tremor score, and PIGD score (all p<0.05).

CONCLUSION

DKI histogram analysis was useful to diagnose and discriminate different motor subtypes of PD. Certain DKI histogram features correlated with clinical indicators.

The Effect of Stereotactic Body Radiotherapy (SBRT) Dose-Fraction (fx) Schema on Non-Small Cell Lung Cancer (NSCLC)

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) dose-fraction (fx) schema for non-small cell lung cancer (NSCLC) varies at different centers and commonly involves 3 to 5 fx. Additionally, the frequency of treatment per week, or treatment schedules (TS), can also differ. We sought to evaluate and compare the effect of different dose-fx schemas on overall survival (OS).

MATERIALS/METHODS

We retrieved data from the National Cancer Database. Patient eligibility included early-stage NSCLC with cT1-2 N0M0 disease treated with SBRT using 3-5f x regimens. Demographics and clinical characteristics were identified. Biologically effective dose (BED) and total dose (TD) were calculated. TD included following: 45-60 Gy for 3 fx, 48-60 Gy for 4 fx, and 50-60 Gy for 5 fx. TS was classified as one of the following: daily, every other day, twice per week, or prolonged (less frequently than twice weekly). Non-prolonged TS was defined as daily, every other day, and twice per week. OS was calculated from the date of end of RT to the date of death and censored at the date of last contact. Kaplan Meier method was used to estimate OS and log-rank tests were used to compare the difference between groups. TS was compared pairwise within each individual fx-group. Univariable Cox proportional models with robust standard errors to account for within institution correlations were used to investigate the association between BED, TD, TS, fx-group and OS. Within each fx-group, BED was also assessed and compared.

RESULTS

A total of 3244 patients were identified, with median age 73. 48% were males and 52% females. 601 (19%) patients received 3 fx, 884 (27%) received 4 fx, and 1759 (54%) received 5 fx treatments. For the overall cohort, median and mean BEDs were 112 and 119, respectively. TS did not show a difference in OS among each individual fx group. Overall, prolonged vs non-prolonged schedules also did not show a difference in OS (p = 0.64). OS was superior in the 3 fx group compared to 4 and 5 fx groups, with median survival times of 61.5 vs 53.7 vs 52.6 months, respectively (p = 0.046). Overall, an increase in BED reduced risk of death (HR = 0.97 per 10-units, CI: 0.94-0.99, p = 0.04). When stratified by fx, each 10 unit rise in BED for those treated with 5 fx reduced the risk of death by 8% (HR = 0.92, CI: 0.87-0.97, p<0.01). However, increasing BED was not associated with change in OS for 3 fx (HR = 1.00, CI: 0.93-1.08, p = 0.93) and 4 fx (HR = 1.08, p = 0.08) regimens. Patients who received BED greater than the median (BED>112) had improved OS compared to those receiving BED£112 (HR = 0.86, p = 0.047). When evaluating the 5 fx-group individually, BED >100 (median of 5fx group) had superior OS compared to £100 (HR = 0.80, p = 0.02).

CONCLUSION

Three-fraction regimens have superior OS compared to 4 and 5 fx regimens. Higher BED improves OS in 5 fx regimens. Treatment schedule variations among individual fx-groups does not impact OS.

The Impact of Mutations of BRCA1/2 Genes in Patients with Breast Cancer on Treatment Outcomes Following Radiation Therapy (RT)

PURPOSE/OBJECTIVE(S)

BRCA1/2 mutations in isolated cancer cells have been shown to enhance radiosensitivity, but it is not known if similar mutations in breast cancer (BC) patients yield improved responses to RT. We analyzed a large, national, previously unexamined dataset to determine if patients with BRCA1/2 mutations receiving RT achieve longer disease-free survival (DFS) and overall survival (OS) than patients with wild-type (WT) BRCA genes.

MATERIALS/METHODS

The study used the nationwide Flatiron Health electronic health record (EHR)-derived de-identified database to select patients with Stage 0-III BC. Patients with known BRCA1/2 status were eligible if treated with RT≤ 1 year from diagnosis. Demographic data for patients with mutated and WT BRCA1/2 were compared using ANOVA and Chi-square tests. DFS was calculated from the start of RT until local/ distant recurrence or death and censored after the last clinic visit. Kaplan Meier estimates and multivariable Cox-proportional models (MVA) were used to compare DFS and OS for mutated and WT BRCA1/2 patients, for clinical stage, biomarkers (ER/PR/HER2), and surgery type (lumpectomy vs mastectomy).

RESULTS

The study group of 1561 Stage 0-III BC patients included 1482 patients (95%) with WT BRCA and 79 patients (5%) with BRCA1/2 mutations (31 patients with a mutation of BRCA1, 46 patients with a mutation of BRCA2, and 2 patients with both mutations). Patients with BRCA1/2 mutations were younger (median: 51 vs 56, p = 0.004), diagnosed at higher clinical stage (Stage 0: 0% vs 0.2%, I: 31.6% vs 48.5%, II: 48.1% vs 34.0%, III: 20.3 vs 17.4%, p = 0.016), and more often grade 3 (60.8% vs 39.9%, p<0.001) than those with WT BRCA. Mastectomy was performed more often for patients with BRCA1/2 mutations (60.8% vs 31.5%, p<0.001). When BRCA1 and BRCA2 mutations were compared, BRCA1 patients were younger (median: 44 vs 52, p = 0.006), more often ER/PR negative (51.6% vs 13%, p<0.001), and had higher stage tumors (T1: 32.3% vs 47.8%; T2: 38.7% vs 28.3%, p = 0.032). On MVA, comparison of BRCA1/2 mutations vs WT BRCA identified no differences in DFS or OS.

CONCLUSION

In spite of pre-clinical data demonstrating increased radiosensitivity for BRCA1/2-mutated BC cells lines, this large, previously unexamined dataset found BRCA1/2 mutations did not predict an improved OS or DFS for patients who received RT. When compared with WT BRCA patients, patients with BRCA1/2 mutations were found to have tumors of higher grade and clinical stage and to undergo more mastectomies. In a comparison with BRCA2-mutated patients, patients with mutations of BRCA1 were younger, more often ER/PR negative, and more likely to have high-stage tumors. The survival data and the advanced stage of BRCA1/2-mutated tumors suggest that the effect of BRCA1/2 mutations on radiosensitivity in vitro may be nullified by the aggressive behavior of BRCA1/2-mutated tumors in vivo.

[Analysis of the serum bile acid profile to facilitate diagnosis and differential diagnosis of NA(+)-taurocholate cotransporting polypeptide deficiency]

Objective: This study focuses on Na(+)-taurocholate cotransporting polypeptide (NTCP) deficiency to analyze and investigate the value of the serum bile acid profile for facilitating the diagnosis and differential diagnosis. Methods: Clinical data of 66 patients with cholestatic liver diseases (CLDs) diagnosed and treated in the Department of Pediatrics of the First Affiliated Hospital of Jinan University from early April 2015 to the end of December 2021 were collected, including 32 cases of NTCP deficiency (16 adults and 16 children), 16 cases of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), 8 cases of Alagille syndrome, and 10 cases of biliary atresia. At the same time, adult and pediatric healthy control groups (15 cases each) were established. The serum bile acid components of the study subjects were qualitatively and quantitatively analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry. The data were plotted and compared using statistical SPSS 19.0 and GraphPad Prism 5.0 software. The clinical and bile acid profiles of children with NTCP deficiency and corresponding healthy controls, as well as differences between NTCP deficiency and other CLDs, were compared using statistical methods such as t-tests, Wilcoxon rank sum tests, and Kruskal-Wallis H tests. Results: Compared with the healthy control, the levels of total conjugated bile acids, total primary bile acids, total secondary bile acids, glycocholic acid, taurocholic acid, and glycochenodeoxycholic acid were increased in NTCP deficiency patients (P < 0.05). Compared with adults with NTCP deficiency, the levels of total conjugated bile acids and total primary bile acids were significantly increased in children with NTCP deficiency (P < 0.05). The serum levels of taurochenodeoxycholic acid, glycolithocholate, taurohyocholate, and tauro-α-muricholic acid were significantly increased in children with NTCP deficiency, but the bile acid levels such as glycodeoxycholic acid, glycolithocholate, and lithocholic acid were decreased (P < 0.05). The serum levels of secondary bile acids such as lithocholic acid, deoxycholic acid, and hyodeoxycholic acid were significantly higher in children with NTCP deficiency than those in other CLD groups such as NICCD, Alagille syndrome, and biliary atresia (P < 0.05). Total primary bile acids/total secondary bile acids, total conjugated bile acids/total unconjugated bile acids, taurocholic acid, serum taurodeoxycholic acid, and glycodeoxycholic acid effectively distinguished children with NTCP deficiency from other non-NTCP deficiency CLDs. Conclusion: This study confirms that serum bile acid profile analysis has an important reference value for facilitating the diagnosis and differential diagnosis of NTCP deficiency. Furthermore, it deepens the scientific understanding of the changing characteristics of serum bile acid profiles in patients with CLDs such as NTCP deficiency, provides a metabolomic basis for in-depth understanding of its pathogenesis, and provides clues and ideas for subsequent in-depth research.

Deepened snow cover increases grassland soil carbon stocks by incorporating carbon inputs into deep soil layers

Climate-induced changes in snow cover can greatly impact winter soil microclimate and spring water supply. These effects, in turn, can influence plant and microbial activity and the strength of leaching processes, potentially altering the distribution and storage of soil organic carbon (SOC) across different soil depths. However, few studies have examined how changes in snow cover will affect SOC stocks, and even less is known about the impact of snow cover on SOC dynamics along soil profiles. By selecting 11 snow fences along a 570 km climate gradient in Inner Mongolia, covering arid, temperate, and meadow steppes, we measured plant and microbial biomass, community composition, SOC content, and other soil parameters from topsoil to a depth of 60 cm. We found that deepened snow increased aboveground and belowground plant biomass, as well as microbial biomass. Plant and microbial carbon input were positively correlated with grassland SOC stocks. More importantly, we found that deepened snow altered SOC distribution along vertical soil profiles. The increase in SOC caused by deepened snow was much greater in the subsoil (+74.7%; 0-5 cm) than that in the topsoil (+19.0%; 40-60 cm). Additionally, the controls on SOC content under deepened snow differed between the topsoil and subsoil layers. The increase in microbial and root biomass jointly enhanced topsoil C accumulation, while the increase in leaching processes became critical in promoting subsoil C accumulation. We conclude that under deepened snow, the subsoil had a high capacity to sink C by incorporating C leached from the topsoil, suggesting that the subsoil, originally thought to be climate insensitive, could have a higher response to precipitation changes due to vertical C transport. Our study highlights the importance of considering soil depth when assessing the impacts of snow cover changes on SOC dynamics.

Tree mycorrhizal association types control biodiversity-productivity relationship in a subtropical forest

Mycorrhizae are symbiotic associations between terrestrial plants and fungi in which fungi obtain nutrients in exchange for plant photosynthates. However, it remains unclear how different types of mycorrhizae affect their host interactions and productivity. Using a long-term experiment with a diversity gradient of arbuscular (AM) and ectomycorrhizal (EcM) tree species, we show that the type of mycorrhizae critically controls the effect of diversity on productivity. With increasing diversity, the net primary production of AM trees increased, but EcM trees decreased, largely because AM trees are more effective in acquiring nitrogen and phosphorus. Specifically, with diversity increase, AM trees enhance both nutrient resorption and litter decomposition, while there was a trade-off between litter decomposability and nutrient resorption in EcM trees. These results provide a mechanistic understanding of why AM trees using a different nutrient acquisition strategy from EcM trees can dominate in subtropical forests and at the same time their diversity enhances productivity.

Integrative analyses of radiation-related genes and biomarkers associated with breast cancer

OBJECTIVE

In addition to significantly reducing breast cancer recurrence risk, radiotherapy also prolongs patients' lives. However, radiotherapy-related genes and biomarkers still remain poorly understood. The present study aimed to identify radiation-associated genes in breast cancer.

MATERIALS AND METHODS

Breast cancer data were downloaded from Gene Expression Omnibus (GEO) and UCSC Xena database. The gene ontology (GO) enrichment and gene set enrichment analysis (GSEA) were performed for annotation and integrated discovery. Protein-protein interaction (PPI) network was constructed by STRING database and hub genes were identified. Then, immunohistochemistry and tissue expression of key genes was analyzed by using the Human Protein Atlas (HPA) and GEPIA database. Genes associated with prognosis were identified by performing univariate cox analysis.

RESULTS

We identified 341 differentially expressed genes related to radiotherapy in breast cancer patients. PPI analysis revealed a total of 129 nodes and 516 interactions and identified five hub genes (EGFR, FOS, ESR1, JUN, and IL6). In addition, 11 SDEGs THBS1, SERPINA11, NFIL3, METTL7A, KCTD12, HSPA6, EGR1, DDIT4, CCDC3, C11orf96, and BCL2A1 candidate genes can be used as potential diagnostic markers. The calibration curve and ROC indicate good probability consistencies of 3-years and 5-year survival rates of patients between estimation and observation.

CONCLUSIONS

Our findings provide novel insight into the functional characteristics of breast cancer through integrative analysis of GEO data and suggest potential biomarkers and therapeutic targets for breast cancer.

Quantitative evaluation of precautions against the COVID-19 indoor transmission through human coughing

In this work, we focus on the dispersion of COVID-19-laden droplets using the transient computational fluid dynamics (CFD) modeling and simulation of the coughing process of virus carriers in an enclosure room, aiming to set up the basic prototype of popular precautionary strategies, i.e., face mask, upward ventilation, protective screen, or any combination thereof, against the indoor transmission of COVID-19 and other highly contagious diseases in the future. A multi-component Eulerian-Lagrangian CFD particle-tracking model with user-defined functions is utilized under 8 cases to examine the characteristics of droplet dispersion concerning the mass and heat transfer, droplet evaporation, air buoyancy, air convection, air-droplet friction, and turbulent dispersion. The result shows that implementing upward ventilation is the most effective measure, followed by wearing face masks. Protective screens can restrict the movement of the coughing droplets (though it will not reduce viral load). However, applying protective screens arranged with lean can be counterproductive in preventing the spread of COVID-19 when it is inappropriately placed with ventilation. The soundest solution is the combination of the face mask and upward ventilation, which can reduce the indoor infectious concentration by nearly 99.95% compared with the baseline without any precautionary strategies. With the resumption of school and work in the post-epidemic era, this study would provide intelligence-enhancing advice for the masses and rule-makers to curb the pandemic.

Deepened snow loosens temporal coupling between plant and microbial N utilization and induces ecosystem N losses

Seasonal differences in plant and microbial nitrogen (N) acquisition are believed to be a major mechanism that maximizes ecosystem N retention. There is also a concern that climate change may interrupt the delicate balance in N allocation between plants and microbes. Yet, convincing experimental evidence is still lacking. Using a ¹⁵ N tracer, we assessed how deepened snow affects the temporal coupling between plant and microbial N utilization in a temperate Mongolian grassland. We found that microbial ¹⁵ N recovery peaked in winter, accounting for 22% of the total ecosystem ¹⁵ N recovery, and then rapidly declined during the spring thaw. By stimulating N loss via N₂ O emission and leaching, deepened snow reduced the total ecosystem ¹⁵ N recovery by 42% during the spring thaw. As the growing season progresses, the ¹⁵ N released from microbial biomass was taken up by plants, and the competitive advantage for N shifted from microbes to plants. Plant ¹⁵ N recovery reached its peak in August, accounting for 17% of the total ecosystem ¹⁵ N recovery. The Granger causality test showed that the temporal dynamics of plant ¹⁵ N recovery can be predicted by microbial ¹⁵ N recovery under ambient snow but not under deepened snow. In addition, plant ¹⁵ N recovery in August was positively correlated with and best explained by microbial ¹⁵ N recovery in March. The lower microbial ¹⁵ N recovery under deepened snow in March reduced plant ¹⁵ N recovery by 73% in August. Together, our results provide direct evidence of seasonal differences in plant and microbial N utilization that are conducive to ecosystem N retention; however, deepened snow disrupted the temporal coupling between plant-microbial N use and turnover. These findings suggest that changes in snowfall patterns may significantly alter ecosystem N cycling and N-based greenhouse gas emissions under future climate change. We highlight the importance of better representing winter processes and their response to winter climate change in biogeochemical models when assessing N cycling under global change.

Protection of Toll-Like Receptor 9 Against Lipopolysaccharide-Induced Inflammation and Oxidative Stress of Pulmonary Epithelial Cells via MyD88-Mediated Pathways

Acute lung injury (ALI) caused by lipopolysaccharide (LPS) is a common, severe clinical syndrome. Injury caused by inflammation and oxidative stress in vascular endothelial and alveolar epithelial cells is a vital process in the pathogenesis of ALI. Toll-like receptor 9 (TLR9) is highly expressed in LPS-induced ALI rats. In this study, Beas-2B human pulmonary epithelial cells and A549 alveolar epithelial cells were stimulated by LPS, resulting in the upregulation of TLR9 in a concentration-dependent manner. Furthermore, TLR9 overexpression and interference vectors were transfected before LPS administration to explore the role of TLR9 in LPS-induced ALI in vitro. The findings revealed that inhibition of TLR9 reduced inflammation and oxidative stress while suppressing apoptosis of LPS-induced Beas-2B and A549 cells, whereas TLR9 overexpression aggravated these conditions. Moreover, TLR9 inhibition resulted in downregulated protein expression of myeloid differentiation protein 88 (MyD88) and activator activator protein 1 (AP-1), as well as phosphorylation of nuclear factor-B (NF-B), c-Jun N terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK). The phosphorylation of extracellular-regulated protein kinases 1/2 was upregulated compared to that of cells subjected to only LPS administration, and this was reversed by TLR9 overexpression. These results indicate that inhibition of TLR9 plays a protective role against LPS-induced inflammation and oxidative stress in Beas-2B and A549 cells, possibly via the MyD88/NF-B and MyD88/MAPKs/AP-1 pathways.

Application of an alkali destruction technique and natural deep eutectic solvent for greener extraction from peanut shells: optimization and extraction kinetics study

Peanut shells are an agricultural by-product rich in flavonoids, but their utilization is not high at present. This research developed a method for the rational utilization of flavonoids in peanut shells, which could enhance the comprehensive utilization of peanut resources. A green and efficient natural extraction technique based on a natural deep eutectic solvent (NADES) and alkaline destruction was exploited for the extraction of the flavonoids from peanut shells. NADES synthesized with DL-menthol (Me) and DL-lactic acid (LA) was selected as the solvent. KOH was used as a destructive agent that could destroy the structure of Me/LA, which could aid not only recovering the flavonoids, but also aid Me recovery and recycling. The NADES with the molar ratio of Me to LA of 1 : 4 showed a higher extraction capacity for flavonoids and better maintenance of antioxidant activity than water and ethanol. The maximum extraction efficiency was 23.33 mg rutin equivalents per g. In addition, the mass-transfer kinetics model of flavonoids extraction was established using Fick's second law, which well fitted the experimental results and proved that the temperature had a significant effect on the extraction efficiency. These results offered some insights for the research and exploitation of an environmentally friendly method to extract bio-active flavonoids for future applications in actual industrial manufacturing.

[METTL27 is a prognostic biomarker of colon cancer and associated with immune invasion]

OBJECTIVE

To investigate the expression and gene function of methyltransferase-like protein 27 (METTL27) in colon cancer, its association with immune infiltration and its prognostic significance.

METHODS

We analyzed the expression levels of METTL27 in 33 cancers using R language and identified METTL27 as a differential gene in colon cancer. The related signaling pathways of METTL27 were analyzed by gene functional annotation and enrichment. SsGSEA algorithm was used to analyze immune infiltration, and logistic analysis was used to evaluate the correlation between METTL27 expression and clinicopathological features of the patients. Kaplan-meier analysis, univariate and multivariate Cox regression analysis were performed to construct a nomogram for evaluating the correlation between METTL27 expression and clinical prognosis. The expression level of METTL27 was further verified in colorectal cancer cell lines and 16 clinical specimens of colorectal cancer tissues using qPCR and Western blotting.

RESULTS

METTL27 was highly expressed in 21 cancers, and its expression was significantly higher in colon cancer than in adjacent tissues (P < 0.001). METTL27-related genes were identified by differential analysis, and functional annotation revealed that METTL27 was significantly enriched in transmembrane transport and lipid metabolism, and 5 related signaling pathways were identified by GSEA. METTL27 expression was negatively correlated with different T helper cells and central memory T cells (P < 0.001). The patients with a high METTL27 mRNA expression had a poor survival outcome. Cox regression analysis showed that METTL27 expression was an independent prognostic factor of the overall survival. The expression level of METTL27 was significantly higher in the colorectal cancer cell line than in normal cells (P < 0.05).

CONCLUSION

METTL27 is overexpressed in colon cancer and is associated with a poor prognosis of the patients. A high expression of METTL27 showed is associated less T cell immune infiltration, suggesting the potential of METTL27 as a prognostic marker of colon cancer.

Effect of COVID-19 Infection on HeartCare, Data from the SHORE Multicenter Registry

Purpose

Transplant patients represent a cohort in which COVID-19 (C19) may stimulate an unpredictable clinical course. The aim of this study was to evaluate the impact of C19 infection on AlloMap gene expression profiling (AM) and AlloSure donor derived cell free DNA (AS) results in patients post heart transplant.

Methods

The Surveillance Using HeartCare Outcomes Registry (SHORE) is a multicenter study for post heart transplant patients followed with AM/AS for 5 years. Patients enrolled were analyzed based on C19 . AM/AS were evaluated before, at the time and following infection. Both individual trends and the differences between the median AS and AS levels were studied. Nonparametric tests were used to assess categorical and longitudinal variables.

Results

21 patients developed C19 infection; 16 (76%) were males, median age 50 years. There was no significant difference in AM or AS in stable patients (no rejection, CAV, graft dysfunction, dnDSA) compared to the first AM/AS profile in the C19+ patients, Figure 1. Event rates in C19+ patients are described in Table 1. 12 C19+ patients had 28 biopsies, 2 of which were within 30 days of C19. 1 patient had ACR 2R and another AMR 1; all other biopsies were <ACR 2R/AMR1. Additionally, 5 patients developed dnDSA and 7 patients developed subsequent CMV viremia, a median of 67 and 158 days after C19 diagnosis, respectively. No CAV, graft dysfunction, or deaths were reported in this small group of C19+ patients.

Conclusion

The presence of C19 infection is not associated with a significant increase in AS or AM scores, suggesting AS and AM are not confounded by C19 and can be used safely as non-invasive surveillance in this population.

The changes in plant and soil C pools and their C:N stoichiometry control grassland N retention under elevated N inputs

Nitrogen (N) retention is a critical ecosystem function for maintaining soil fertility and mitigating pollution caused by anthropogenic N input. However, it has not yet been elucidated how responses of plant and soil regulate ecosystem N retention. Here, we combined a 14-year N addition experiment in a temperate steppe with a global meta-analysis in grasslands, to assess changes in carbon (C) pool size and stoichiometric C:N ratio of plant and soil components and evaluate the contribution of each component to grassland N retention under increasing N levels. We found that N addition increased N storage in the plant pool by stimulating biomass production and reducing tissue C:N at the community level. However, the non-random loss of forbs and legumes associated with a low C:N ratio partially offset the decline in community-level C:N ratio, thereby diminishing the positive net effect of N enrichment on plant N storage. The observed increase in soil N storage was predominantly determined by the decrease in C:N ratio of topsoil, while no changes were detected in the subsoil. On 14-year time scale, the upper limitation of N retention capacity in our study site was 167.02 g N/m² . Global meta-analysis further indicated that a decade's N addition significantly increased the N storage in shoot, root and topsoil through enhancing the C pool and decreasing the C:N ratio, while did not affect those of subsoil. However, the positive correlation between the response of subsoil N storage and treatment duration further indicates that, though the accumulation of added N lagged behind that of topsoil, subsoil could play an important role in N retention on a longer time scale. Our study demonstrated that the enhanced plant productivity and altered physiological metabolism indicated by the decreased C:N ratio jointly determined grassland ecosystem N retention. The capacity of the grassland ecosystem to retain exogenous N input is limited, especially for a large amount of N input that occurs in a short period. However, in the context of chronically rising N deposition, the long-term N retention capacity of grasslands should largely depend on the response of subsoil, especially after topsoil N is saturated.

Long-term nitrogen input alters plant and soil bacterial, but not fungal beta diversity in a semiarid grassland

Anthropogenic nitrogen (N) input is known to alter plant and microbial α-diversity, but how N enrichment influences β-diversity of plant and microbial communities remains poorly understood. Using a long-term multilevel N addition experiment in a temperate steppe, we show that plant, soil bacterial and fungal communities exhibited different responses in their β-diversity to N input. Plant β-diversity decreased linearly as N addition increased, as a result of increased directional environmental filtering, where soil environmental properties largely explained variation in plant β-diversity. Soil bacterial β-diversity first increased then decreased with increasing N input, which was best explained by corresponding changes in soil environmental heterogeneity. Soil fungal β-diversity, however, remained largely unchanged across the N gradient, with plant β-diversity, soil environmental properties, and heterogeneity together explaining an insignificant fraction of variation in fungal β-diversity, reflecting the importance of stochastic community assembly. Our study demonstrates the divergent effect of N enrichment on the assembly of plant, soil bacterial and fungal communities, emphasizing the need to examine closely associated fundamental components (i.e., plants and microorganisms) of ecosystems to gain a more complete understanding of ecological consequences of anthropogenic N enrichment.

Prediction of potential therapeutic drugs against SARS-CoV-2 by using Connectivity Map based on transcriptome data

OBJECTIVE

Transcriptome data related to severe acute respiratory syndrome-related coronavirus 2 (a novel coronavirus discovered in 2019, SARS-CoV-2) in GEO database were downloaded. Based on the data, influence of SARS-CoV-2 on human cells was analyzed and potential therapeutic compounds against the SARS-CoV-2 were screened.

MATERIALS AND METHODS

R package "DESeq2" was used for differential gene analysis on the data of cells infected or non-infected with SARS-CoV-2. The "ClusterProfiler" package was used for GO functional annotation and KEGG pathway enrichment analysis of the differentially expressed genes (DEGs). A protein-protein interaction (PPI) network of the DEGs was constructed through STRING website, and the key subset in the PPI network was identified after visualization by Cytoscape software. Connectivity Map (CMap) database was used to screen known compounds that caused genomic change reverse to that caused by SARS-CoV-2.

RESULTS

By intersecting DEGs in two datasets, a total of 145 DEGs were screened out, among which 136 genes were upregulated and 9 genes were downregulated in SARS-CoV-2-infected cells. Functional enrichment analyses revealed that these genes were mainly associated with the pathways involved in viral infection, inflammatory response, and immunity. The CMap research found that there were three compounds with a median_tau_score less than -90, namely triptolide, tivozanib and daunorubicin.

CONCLUSIONS

SARS-CoV-2 can cause abnormal changes in a large number of molecules and related signaling pathways in human cells, among which IL-17 and TNF signaling pathways may play a key role in pathogenic process of SARS-CoV-2. Here, three compounds that may be effective for the treatment of SARS-CoV-2 were screened, which would provide new options for improving treatment of patients infected with SARS-CoV-2.

Hsa-miR-34a-5p reverses multidrug resistance in gastric cancer cells by targeting the 3'-UTR of SIRT1 and inhibiting its expression

Multidrug resistance (MDR) is a major obstacle to chemotherapy, which leads to ineffective chemotherapy, an important treatment strategy for gastric cancer (GC). The abnormality of microRNAs (miRNAs) is critical to the occurrence and progression of MDR in various tumors. In this study, hsa-miR-34a-5p was found to be decreased in multidrug resistant GC cells SGC-7901/5-Fluorouracil (SGC-7901/5-Fu) compared to the parental SGC-7901 cells. Overexpression of hsa-miR-34a-5p in SGC-7901/5-Fu cells promoted apoptosis and decreased migration and invasiveness after chemotherapy. In addition, overexpression of hsa-miR-34a-5p suppressed the growth of drug-resistant tumor in vivo. The mechanism of the effects of hsa-miR-34a-5p could include the regulation of the expression of Sirtuin 1 (SIRT1), P-glycoprotein (P-gp) or Multidrug resistance-related protein 1 (MRP1) through direct binding to the 3'-untranslated region (UTR) of SIRT1. Functional gain-and-loss experiments indicated that hsa-miR-34a-5p enhances the chemotherapy sensitivity of MDR GC cells by inhibiting SIRT1, P-gp and MRP1. In conclusion, hsa-miR-34a-5p can reverse the MDR of GC cells by inhibiting the expression of SIRT1, P-gp or MRP1.

An incremental feeding pattern for Guangdong Small-ear Spotted gilts during gestation: effects on stillbirth rate and muscle weight of progeny

While an appropriate feed intake is crucial for the reproductive performance of sows, there is a lack of recommendations currently for feed allowance of Guangdong Small-ear Spotted gilts during gestation. The effects of 2 different feeding patterns during gestation on the reproductive performance of Guangdong Small-ear Spotted gilts were investigated by assigning 80 gilts to 2 feeding pattern groups with a randomized complete block design in accordance with initial body weight and back fat thickness, followed by treatment with an incremental feeding pattern (IFP) and a concaved feeding pattern, respectively, with no difference in total feed intake. The IFP group showed a significant decrease in the stillbirth rate (P < 0.05) and an upward trend in piglet mean birth weight (P = 0.06). Furthermore, the IFP group exhibited an increase in the weights of stomach, supraspinatus tendon, triceps, and psoas minor in neonatal piglets (P < 0.05). Overall, the results of the present investigation showed that IFP could significantly reduce the stillbirth rate of Guangdong Small-ear Spotted gilts and increase the muscle weight of progeny.