Microplastic pollution associated with reduced respiration in seagrass (Zostera marina L.) and associated epiphytes

Seagrasses provide crucial ecosystem services of relevance for the marine environment. However, anthropogenic activities are causing global seagrass decline. Increasing microplastic (MP) concentrations have been recognized as a novel threat to many marine organisms, but their effects on marine plants remain underexplored. Here, we investigate the effects of microplastic (polyethylene (PE) and polypropylene (PP)) exposure on the photosynthesis and respiration of the seagrass Zostera marina L. and its associated epiphytes. Measurements were conducted on seagrass leaves with and without epiphyte cover, as well as on epiphytes scraped off the leaf surface. Net gas exchange and pH drift measurements were used to determine rates of photosynthesis and respiration, as well as the ability of leaves and epiphytes to utilize bicarbonate. In addition, variable chlorophyll fluorescence imaging was employed to quantify the photosynthetic capacity of seagrass leaves. Our results show a limited effect of short-term (14 days) microplastic exposure on seagrass leaves and their associated epiphytes, although the photosynthetic activity and respiration rates were gradually reduced for bare seagrass leaves with increasing microplastic concentrations (25-1000 mg MP L-1). A >50% reduction in dark respiration of bare leaves was found at the highest MP exposure, while respiration rates of leaves with epiphytes and separated epiphytes were reduced by maximally ~45 and 30% upon MP exposure, respectively. Short-term microplastic exposure did not alter i) the ability to utilize bicarbonate, ii) the maximum quantum yield of PSII (FV/FM), nor iii) the light utilization efficiency of Z. marina leaves and associated epiphytes. The compensation irradiance decreased for all investigated specimens, and seagrass leaves (with and without epiphytes) were able to retain a positive net oxygen balance throughout all treatments. We speculate that the observed decrease in photosynthetic activity and respiration was caused by leachates from microplastics. Our findings thus indicate that seagrass Z. marina largely possess resilience toward microplastic pollution at its current level

Infant Ustekinumab Clearance, Risk of Infection, and Development After Exposure During Pregnancy

Background:Evidence on ustekinumab safety in pregnancy is gradually expanding, but its clearance in the postnatal period is unknown. The aim of this study was to investigate ustekinumab concentrations in umbilical cord blood and rates of clearance after birth, as well as how these correlate with maternal drug concentrations, risk of infection, and developmental milestones during the first year of life. Methods: Pregnant women with inflammatory bowel disease were prospectively recruited from 19 hospitals in Denmark and the Netherlands between 2018 and 2022. Infant infections leading to hospitalization/antibiotics and developmental milestones were assessed. Serum ustekinumab concentrations were measured at delivery and specific time points. Nonlinear regression analysis was applied to estimate clearance. Results:In 78 live-born infants from 76 pregnancies, we observed a low risk of adverse pregnancy outcomes and normal developmental milestones. At birth, the median infant-mother ustekinumab ratio was 2.18 (95% confidence interval, 1.69–2.81). Mean time to infant clearance was 6.7 months (95% confidence interval, 6.1–7.3 months). One in 4 infants at 6 months had an extremely low median concentration of 0.015 μg/mL (range 0.005–0.12 μg/mL). No variation in median ustekinumab concentration was noted between infants with (2.8 [range 0.4–6.9] μg/mL) and without (3.1 [range 0.7–11.0] μg/mL) infections during the first year of life (P = .41). Conclusions: No adverse signals after intrauterine exposure to ustekinumab were observed with respect to pregnancy outcome, infections, or developmental milestones during the first year of life. Infant ustekinumab concentration was not associated with risk of infections. With the ustekinumab clearance profile, live attenuated vaccination from 6 months of age seems of low risk.</p

A proposal for a study on treatment selection and lifestyle recommendations in chronic inflammatory diseases:A danish multidisciplinary collaboration on prognostic factors and personalised medicine

Chronic inflammatory diseases (CIDs), including Crohn’s disease and ulcerative colitis (inflammatory bowel diseases, IBD), rheumatoid arthritis, psoriasis, psoriatic arthritis, spondyloarthritides, hidradenitis suppurativa, and immune-mediated uveitis, are treated with biologics targeting the pro-inflammatory molecule tumour necrosis factor-α (TNF) (i.e., TNF inhibitors). Approximately one-third of the patients do not respond to the treatment. Genetics and lifestyle may affect the treatment results. The aims of this multidisciplinary collaboration are to identify (1) molecular signatures of prognostic value to help tailor treatment decisions to an individual likely to initiate TNF inhibitor therapy, followed by (2) lifestyle factors that support achievement of optimised treatment outcome. This report describes the establishment of a cohort that aims to obtain this information. Clinical data including lifestyle and treatment response and biological specimens (blood, faeces, urine, and, in IBD patients, intestinal biopsies) are sampled prior to and while on TNF inhibitor therapy. Both hypothesis-driven and data-driven analyses will be performed according to pre-specified protocols including pathway analyses resulting from candidate gene expression analyses and global approaches (e.g., metabolomics, metagenomics, proteomics). The final purpose is to improve the lives of patients suffering from CIDs, by providing tools facilitating treatment selection and dietary recommendations likely to improve the clinical outcome

Autoimmunity in Arabidopsis acd11 Is Mediated by Epigenetic Regulation of an Immune Receptor

Certain pathogens deliver effectors into plant cells to modify host protein targets and thereby suppress immunity. These target modifications can be detected by intracellular immune receptors, or Resistance (R) proteins, that trigger strong immune responses including localized host cell death. The accelerated cell death 11 (acd11) “lesion mimic” mutant of Arabidopsis thaliana exhibits autoimmune phenotypes such as constitutive defense responses and cell death without pathogen perception. ACD11 encodes a putative sphingosine transfer protein, but its precise role during these processes is unknown. In a screen for lazarus (laz) mutants that suppress acd11 death we identified two genes, LAZ2 and LAZ5. LAZ2 encodes the histone lysine methyltransferase SDG8, previously shown to epigenetically regulate flowering time via modification of histone 3 (H3). LAZ5 encodes an RPS4-like R-protein, defined by several dominant negative alleles. Microarray and chromatin immunoprecipitation analyses showed that LAZ2/SDG8 is required for LAZ5 expression and H3 lysine 36 trimethylation at LAZ5 chromatin to maintain a transcriptionally active state. We hypothesize that LAZ5 triggers cell death in the absence of ACD11, and that cell death in other lesion mimic mutants may also be caused by inappropriate activation of R genes. Moreover, SDG8 is required for basal and R protein-mediated pathogen resistance in Arabidopsis, revealing the importance of chromatin remodeling as a key process in plant innate immunity

MicroRNA expression profiles during cotton (Gossypium hirsutum L) fiber early development

The role of microRNAs (miRNAs) during cotton fiber development remains unclear. Here, a total of 54 miRNAs belonging to 39 families were selected to characterize miRNA regulatory mechanism in eight different fiber development stages in upland cotton cv BM-1. Among 54 miRNAs, 18 miRNAs were involved in cotton fiber initiation and eight miRNAs were related to fiber elongation and secondary wall biosynthesis. Additionally, 3,576 protein-coding genes were candidate target genes of these miRNAs, which are potentially involved in cotton fiber development. We also investigated the regulatory network of miRNAs and corresponding targets in fiber initiation and elongation, and secondary wall formation. Our Gene Ontology-based term classification and KEGG-based pathway enrichment analyses showed that the miRNA targets covered 220 biological processes, 67 molecular functions, 45 cellular components, and 10 KEGG pathways. Three of ten KEGG pathways were involved in lignan synthesis, cell elongation, and fatty acid biosynthesis, all of which have important roles in fiber development. Overall, our study shows the potential regulatory roles of miRNAs in cotton fiber development and the importance of miRNAs in regulating different cell types. This is helpful to design miRNA-based biotechnology for improving fiber quality and yield