Inhibiting Peptidoglycan Hydrolase Alleviates MRSA Pneumonia Through Autolysin-Mediated MDP-NOD2 Pathway.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a cause of staph infection that is difficult to treat because of resistance to some antibiotics. A recent study indicated that diarylurea ZJ-2 is a novel antibacterial agent against multi-drug resistant Enterococcus faecium. In this work, we refined the bactericidal mechanism of ZJ-2 as a peptidoglycan (PG) hydrolase by affecting AtlA-mediated PG homeostasis. Methods: A wild-type strain (WT) and a mutant strain (ΔatlA) were used to investigate the effects of ZJ-2 on the cell wall, PG, and autolysin regulatory system by antimicrobial susceptibility testing, hemolytic toxin assay, microanalysis, autolysis assay, qRT-PCR, ELISA and mouse model of pneumonia. Results: The results revealed that ZJ-2 down-regulated the expression of genes related to peptidoglycan hydrolase (PGH) (sprX, walR, atlA, and lytM), and reduced the levels of PG, muramyl dipeptide (MDP), cytokines, and hemolytic toxin, while ΔatlA interfered with the genes regulation and PG homeostasis. In the mouse MRSA pneumonia model, the same trend was observed in the nucleotide oligomerization domain protein 2 (NOD2) and relative proinflammatory factors. Conclusion: ZJ-2 may act as a novel inhibitor of PG hydrolyse, disrupting autolysin-mediated PG homeostasis, and reducing inflammation by down-regulating the MDP-NOD2 pathway.

Simulated nitrogen load promoted mineralization of N2P1 compounds and accumulation of N4S2 compounds in soil dissolved organic matter in a typical subtropical estuarine marsh.

Soil dissolved organic matter (DOM) is the most reactive pool in estuarine marshes, playing an important role in the biogeochemical processes of biogenetic elements. To investigate the impacts of enhanced nitrogen (N) load on DOM molecular composition and its interactions with microbes in typical Cyperus malaccensis mashes of the Min River estuary, a field N load experiment with four N levels (0, 37.50, 50 and 100 g exogenous N m-2 yr-1, respectively; applied monthly for a total of seven months) was performed. DOM molecular composition was characterized by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), the microbial community compositions (MCC, including fungi and bacteria) were determined by high-throughput sequencing technique, and their relationships were presented by co-occurrence network analysis. The results indicated that enhanced N load had significant impacts on soil DOM molecular composition, with N/C and P/C of DOM decreasing but S/C increasing markedly. Meanwhile, enhanced N load decreased the percentages of N2P1 compounds (primarily lipids) but increased those of N4S2 compounds (mainly lignins and lipids). The relative abundances of lignins significantly increased with increasing N load levels, whereas the proportions of lipids decreased. The abundance of N2P1 and N4S2 compounds was primarily positively correlated with eutrophic and oligotrophic microorganisms, respectively. Therefore, mineralization of N2P1 compounds might act as a source to replenish inorganic P, while enrichment of N4S2 compounds may make great contribution to organic S accumulation. Overall, enhanced N load promoted P depletion and S enrichment via altering plant growth, litter decomposition and MCC.

Multiple factors and features dictate the selective production of ct-siRNA in Arabidopsis.

Coding transcript-derived siRNAs (ct-siRNAs) produced from specific endogenous loci can suppress the translation of their source genes to balance plant growth and stress response. In this study, we generated Arabidopsis mutants with deficiencies in RNA decay and/or post-transcriptional gene silencing (PTGS) pathways and performed comparative sRNA-seq analysis, revealing that multiple RNA decay and PTGS factors impede the ct-siRNA selective production. Genes that produce ct-siRNAs often show increased or unchanged expression and typically have higher GC content in sequence composition. The growth and development of plants can perturb the dynamic accumulation of ct-siRNAs from different gene loci. Two nitrate reductase genes, NIA1 and NIA2, produce massive amounts of 22-nt ct-siRNAs and are highly expressed in a subtype of mesophyll cells where DCL2 exhibits higher expression relative to DCL4, suggesting a potential role of cell-specific expression of ct-siRNAs. Overall, our findings unveil the multifaceted factors and features involved in the selective production and regulation of ct-siRNAs and enrich our understanding of gene silencing process in plants.

On-site rapid detection of perfluorooctanoic acid by visual immunochromatographic strip biosensor in domestic water and real human samples.

The International Agency for Research on Cancer (IARC) classifies PFOA as a Class 1 carcinogen. Here, a new naked-eye PFOA immunochromographic strip was developed to recognize PFOA in domestic water and real human samples within 10 min based on a novel custom designed anti-PFOA monoclonal antibody (mAb) 2A3, which was firstly an immune rapid detection method for PFOA has been proposed. Using computer simulation techniques such as quantum computing to assist in designing the structural formula of PFOA semi antigen, which hapten was firstly proposed. The half maximal inhibitory concentration of PFOA monoclonal antibody (mAb) 2A3 was 2.4 µg/mL. Using mAb 2A3, we developed an immunochromatographic strip (ICS) for detecting PFOA in real samples. The developed method generated results in 10 min, with visual detection limits of 20, 20, and 200 µg/mL and limit of detection of 50, 200, and 500 µg/mL for water, blood and urine samples, respectively. The established ICS and indirect competitive enzyme-linked immunosorbent assay were used to analyze the actual samples, and the results were confirmed by LC-MS/MS. Our study findings showed that the ICS and ic-ELISA can quickly detect PFOA in actual samples.

FOXM1 promotes the progression of non-small cell lung cancer by inhibiting miR-509-5p expression via binding to the miR-509-5p promoter region.

Background: Forkhead box M1 (FOXM1) functions as a transcription factor and is consistently overexpressed in various cancers, including non-small-cell lung-, breast-, cervical-, and colorectal cancer. Its overexpression is associated with poor prognosis in patients with non-small-cell lung cancer, although the detailed mechanisms by which FOXM1 promotes the development of non-small-cell lung cancer remain unclear. Objective: The mechanism of FOXM1 in migration, invasion, apoptosis, and viability of lung cancer cells was investigated. Methods: Transwell assay, scratch test, and flow cytometry were employed to study the effects of FOXM1 on migration, invasion, and apoptosis in A549 cells. A quantitative polymerase chain reaction was used to determine the impact of FOXM1 on miR-509-5p expression in A549 cells. Dual-luciferase reporter gene assay and chromatin immunoprecipitation were adopted to investigate the molecular mechanisms of FOXM1 on miR-509-5p expression. Results: FDI-6 (a FOXM1 inhibitor) reduced the protein abundance of FOXM1, thereby increasing the expression of miR-509-5p in A549 cells. Moreover, FDI-6 treatment significantly reduced migration, invasion, and viability of A549 cells while promoting cell apoptosis. Furthermore, miR-509-5p inhibitor obviously alleviated the biological effects of FDI-6 on A549 cells, suggesting that FOXM1 primarily exerted its cancer promoting effect by regulating miR-509-5p. Mechanistically, FOXM1 directly bound to the miR-509-5p promoter to inhibit miR-509-5p expression. Conclusion: FOXM1 directly binds to the promoter region of miR-509-5p to form a negative feedback loop, thereby inhibiting miR-509-5p expression and promoting the development of non-small-cell lung cancer. This study is expected to complement research on the pathogenesis of non-small-cell lung cancer and promote the development of novel therapeutic targets for this disease.

Research progress in spasmodic torticollis rehabilitation treatment.

Spasmodic torticollis (ST) is a focal dystonia that affects adults, causing limited muscle control and impacting daily activities and quality of life. The etiology and curative methods for ST remain unclear. Botulinum toxin is widely used as a first-line treatment, but long-term usage can result in reduced tolerance and adverse effects. Rehabilitation therapy, with its minimal side effects and low potential for harm, holds significant clinical value. This article explores the effectiveness of adjunctive therapies, including exercise therapy, transcranial magnetic stimulation, shockwave therapy, neuromuscular electrical stimulation, vibration therapy, electromyographic biofeedback, and acupuncture, in the treatment of ST. The aim is to provide clinicians with additional treatment options and to discuss the efficacy of rehabilitation therapy for ST.

Formononetin attenuates cigarette smoke-induced COPD in mice by suppressing inflammation, endoplasmic reticulum stress, and apoptosis in bronchial epithelial cells via AhR/CYP1A1 and AKT/mTOR signaling pathways.

Chronic obstructive pulmonary disease (COPD) is a chronic, progressive, and lethal lung disease with few treatments. Formononetin (FMN) is a clinical preparation extract with extensive pharmacological actions. However, its effect on COPD remains unknown. This study aimed to explore the effect and underlying mechanisms of FMN on COPD. A mouse model of COPD was established by exposure to cigarette smoke (CS) for 24 weeks. In addition, bronchial epithelial BEAS-2B cells were treated with CS extract (CSE) for 24 h to explore the in vitro effect of FMN. FMN significantly improved lung function and attenuated pathological lung damage. FMN treatment reduced inflammatory cell infiltration and pro-inflammatory cytokines secretion. FMN also suppressed apoptosis by regulating apoptosis-associated proteins. Moreover, FMN relieved CS-induced endoplasmic reticulum (ER) stress in the mouse lungs. In BEAS-2B cells, FMN treatment reduced CSE-induced inflammation, ER stress, and apoptosis. Mechanistically, FMN downregulated the CS-activated AhR/CYP1A1 and AKT/mTOR signaling pathways in vivo and in vitro. FMN can attenuate CS-induced COPD in mice by suppressing inflammation, ER stress, and apoptosis in bronchial epithelial cells via the inhibition of AhR/CYP1A1 and AKT/mTOR signaling pathways, suggesting a new therapeutic potential for COPD treatment.

LncRNA PWRN1 inhibits the progression of hepatocellular carcinoma by activating PKM2 activity.

Hepatocellular carcinoma (HCC) is one of the most prevalent and leading causes of cancer-related mortality worldwide. Long non-coding RNAs (lncRNAs) have been demonstrated to play vital roles in cancer development and progression. The lncRNA PWRN1 (PWRN1), acts as a tumor suppressor factor, which is low expressed in some cancers. However, the molecular mechanisms underlying the effects of PWRN1, especially the regulatory relationship with RNA binding protein in HCC remain largely unknown. In the present study, we demonstrated that PWRN1 was significantly down-regulated in HCC and correlated with better prognosis; furthermore, gain-of-function experiments showed that PWRN1 inhibited the proliferation of HCC cells. We further found that PWRN1 up-regulated pyruvate kinase activity and thus hinders the proliferation of HCC in vitro and in vivo. Mechanistically, pyruvate kinase M2 (PKM2) was bound to it and maintained the high activity state of PKM2, thereby hindering PKM2 from entering the nucleus in the form of low-activity dimers, reducing the expression of c-Myc downstream gene LDHA, leading to a decrease in lactate levels, and inhibiting the growth of tumor cells. In addition, PWRN1 was found to inhibit aerobic glycolysis. Finally, TEPP-46, a pyruvate kinase activator, appeared to inhibit HCC proliferation by maintaining tetramer stability and increasing pyruvate kinase activity. Taken together, our results provide new insights into the biology hindering HCC proliferation and indicate that PWRN1 in combination with PKM2 activators might represent a novel therapeutic target for HCC.

Sleep behaviors predicted sleep disturbances among Chinese health science students: a cross-sectional study.

PURPOSE: Healthy sleep is essential for individuals' physiological and psychological health. Health science students experience a high prevalence of sleep disturbances which may be due to maladaptive behaviors. This study aimed to examine the associations of sleep behaviors including sleep hygiene and bedtime procrastination with the associations of sleep disturbances (e.g., poor sleep quality, insomnia, and short sleep). METHODS: This cross-sectional study included health science students from a medical university in Shanghai, China. Sleep disturbances included poor sleep quality, insomnia, and short sleep. They were measured by the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and one question "How many hours of sleep did you usually get during the past week?", respectively. Sleep behaviors included sleep hygiene and bedtime procrastination measured by the Sleep Hygiene Index (SHI) and Bedtime Procrastination Scale (BPS), respectively. Logistic regression was performed while controlling for potential confounders. RESULTS: A total of 464 health science students participated. Poorer overall sleep hygiene and more bedtime procrastination were independently associated with higher odds of poor sleep quality (OR=1.065, 95% CI 1.028-1.103; OR=1.040, 95% CI 1.006-1.075, respectively) and insomnia (OR=1.059, 95% CI 1.018-1.101; OR=1.093, 95% CI 1.049-1.139, respectively). More bedtime procrastination was associated with higher odds of short sleep (OR=1.148, 95% CI 1.093-1.206). Commonly reported specific sleep behaviors, such as "Going to bed later than intended", "Doing other things than sleep at bedtime", and "Easily stopping what I am doing at bedtime", were also related to higher odds of sleep disturbances. CONCLUSIONS: Sleep hygiene and bedtime procrastination were strong predictors of sleep disturbances. Tailored interventions targeting specific sleep behaviors are warranted to clarify their effect on sleep disturbances.

Combination of fractional carbon dioxide laser with recombinant human collagen in periocular skin rejuvenation.

BACKGROUND: The most visible sign of facial aging is often seen in the periocular area. However, periocular rejuvenation remains challenging due to the particularity of periocular anatomic locations. AIMS: We aimed to evaluate the efficacy and safety of the fractional-ablative CO2 laser-facilitated recombinant human collagen permeation in periocular rejuvenation. PATIENTS/METHODS: This 3-month prospective single-blinded and self-controlled trial enrolled 26 patients with periocular aging who underwent the treatments of fractional-ablative CO2 laser along with laser-facilitated recombinant human collagen permeation. Following the treatments, the patients were quantitatively assessed by various periocular skin aging indices before and after the treatment and monitored for any related adverse events. RESULTS: The patients showed significant improvements with the periocular skin aging indices 3 months after the treatments, which were detailed with a 47.3% decrease in lower eyelid skin rhytids, a 41.4% decrease in the lower eyelid skin texture, a 35.0% decrease in the static crow's feet, a 29.3% decrease in the amount of upper eyelid laxity, and a 20.2% increase in the MRD1 as compared with baseline (p < 0.05). Moreover, total skin thickness under ultrasound was increased in both upper and lower eyelids (5.6% and 3.3%, p < 0.05, respectively). Moreover, six patients (23.1%, 6/26) had erythema for 2 weeks, and two (2/26, 7.7%) had mild hyperpigmentation for 3 months. CONCLUSIONS: Fractional-ablative CO2 laser combined with laser-facilitated recombinant human collagen permeation can be a safe and effective treatment for periocular rejuvenation.

Biomimetic affinity membrane roll column for rapid purification of C-reactive protein.

To in-depth explore the action mechanism of C-reactive protein (CRP) and precisely study its signaling pathways, it is essential to acquire high-purity CRP while preserving its intact structure and functionality. In this study, we propose and fabricate a high-density 2-methacryloyloxyethyl phosphorylcholine (MPC)-modified membrane roll column (MPC-MRC) using a surface-initiated atom transfer radical polymerization (SI-ATRP) approach, which can overcome these limitations (long incubation time and low adsorption capacity) of conventional enrichment materials. The MPC-MRC incorporates a high-density 2-hydroxyethyl methacrylate polymer brush to prevent non-specific protein adsorption and multiple MPC polymer brush layers for high-performance enrichment of CRP in the company of calcium ions. Furthermore, the MPC-MRC exhibits high permeability, hydrophilicity, and mechanical strength. Compared to previous technologies, this novel material demonstrates significantly higher CRP binding capacity (310.3 mg/g), shorter processing time (only 15 min), and lower cost (only 12 USD/column). Notably, the MPC-MRC enables fast and effective purification of CRP from both human and rat serum, exhibiting good selectivity, recovery (> 91.3 %), and purity (> 95.2 %). Thus, this proposed purification approach based on MPC-MRC holds great potential for target protein enrichment from complex samples, as well as facilitating in-depth studies of its biological functions.

Impacts of spatial expansion by Phragmites australis on spatiotemporal variation of sulfur fractions in marsh soils of the Min River estuary, Southeast China.

To investigate the impacts of spatial expansion by Phragmites australis on spatiotemporal variations of sulfur (S) fractions in marsh soils of the Min River estuary (Southeast China), the contents of total sulfur (TS) and inorganic sulfur (IS) fractions (Water-Soluble-S, W-S-S; Adsorbed-S, A-S; HCl-Soluble-S, H-S-S; and HCl-Volatile-S, H-V-S) were determined in soils of Cyperus malaccensis marsh (before expansion, BE stage), P. australis-C. malaccensis marsh (during expansion, DE stage) and P. australis marsh (after expansion, AE stage) by space-for-time substitution method. Results showed that the expansion of P. australis greatly altered the spatiotemporal variations of TS and IS fractions in marsh soils. The TS contents in soils at AE stage were significantly lower than those at DE and BE stages throughout a year (p < 0.01). Higher levels of W-S-S, A-S, H-S-S and total inorganic sulfur (TIS) generally occurred in soils at DE and AE stages, whereas higher values of H-V-S were observed in soils at BE stage. Although P. australis expansion did not alter the temporal variations of TS stock in soils greatly, the values during autumn and winter were generally higher than those in spring and summer (p < 0.05). The highest TIS stocks in soils of different expansion stages were observed in spring, while the lowest values occurred in summer. The expansion of P. australis significantly increased the IS supply capacity of soils and, compared with the BE stage, stocks of W-S-S, A-S, H-S-S and TIS in soils of all sampling seasons at DE and AE stages increased by 51.40 %, 50.76 %, 63.35 %, 50.52 % and 20.00 %, 31.46 %, 42.93 %, 27.56 %, respectively. It was worth noting that stocks of H-V-S in soils at DE and AE stages showed a decreasing trend compared to the BE stage, implying that the expansion of P. australis might reduce the production of sulfides. This paper found that, compared with C. malaccensis, the increased available IS stocks in soils might be an effective strategy for P. australis to maintain its expansion advantage and the decreased volatile-S in soils might be more favorable for boosting its competitiveness. Our study provided valuable information for understanding the interspecific competition mechanism between P. australis and C. malaccensis. Next step, in order to protect the diversity of marsh vegetations in the Min River estuary, effective measures should be taken to suppress the rapid expansion of P. australis.

Information Needs and Its Association With Depressive Symptoms in People With Type 2 Diabetes.

PURPOSE: The purpose of this study was to describe the information needs and examine its association with depressive symptoms in people with type 2 diabetes (T2D). METHODS: A descriptive, correlational design was used. People with T2D (N = 358) were recruited from 12 communities in Shanghai, China. Self-reported information needs and depressive symptoms were measured using the Information Needs in Diabetes Questionnaire and Patient Health Questionnaire-9 (PHQ-9), respectively. Multivariate linear regression analysis was performed. RESULTS: The participants were 64.8 years on average, and 46.6% were men. One hundred fifty-one (42.2%) had depressive symptoms (PHQ-9 ≥ 5). Participants had the least knowledge about "diabetes research," "acute complications," and "lifestyle adjustment." The sample had the highest levels of information needs about topics including "mental strain," "treatment/therapy," and "diabetes in everyday life." Compared to those without depressive symptoms, those experiencing depressive symptoms were less informed and had higher levels of need for further information. Controlling for covariates, higher levels of need for further information were significantly associated with greater depressive symptoms (B = 0.368, 95% CI, 0.155-0.582, P = .001). CONCLUSIONS: This study demonstrated areas that should be prioritized when meeting patients' information needs. It also showed the potential negative effect of unmet information needs on depression. These findings may help develop a more tailored intervention for people with T2D.

A chimeric hairpin DNA aptamer-based biosensor for monitoring the therapeutic drug bevacizumab.

The accurate and rapid detection of specific antibodies in blood is very important for efficient diagnosis and precise treatment. Conventional methods often suffer from time-consuming operations and/or a narrow detection range. In this work, for the rapid determination of bevacizumab in plasma, a series of chimeric hairpin DNA aptamer-based probes were designed by the modification, labeling and theoretical computation of an original aptamer. Then, the dissociation constant of the modified hairpin DNA to bevacizumab was measured and screened using microscale thermophoresis. The best chimeric hairpin DNA aptamer-based probe was then selected, and a one-step platform for the rapid determination of bevacizumab was constructed. This strategy has the advantages of being simple, fast and label-free. Because of the design and screening of the hairpin DNA, as well as the optimization of the concentration and electrochemical parameters, a low detection limit of 0.37 pM (0.054 ng mL-1) with a wide linear range (1 pM-1 µM) was obtained. Finally, the rationally constructed biosensor was successfully applied to the determination of bevacizumab in spiked samples, and it showed good accuracy and precision. This method is expected to truly realize accurate and rapid detection of bevacizumab and provides a new idea for the precise treatment of diseases.

Recalcitrant nodular scabies showing excellent response to tofacitinib: five case reports.

Scabies is a contagious skin condition caused by Sarcoptes scabiei, and it is always associated with an intense, unbearable, nocturnal deteriorating itch. Its presentations include classic burrows, erythema, pruritic papules, pustules, vesicles, and inflammatory nodules, with diffuse or localized distribution on the finger webs, wrist flexors, elbows, axillae, buttocks, genitalia, and breasts. Nodular scabies is an uncommon clinical variant of scabies. Its management is still challenging for some patients up to date, although topical, intralesional or systemic corticosteroids, topical calcineurin inhibitors, and crotamiton as well as cryotherapy alone or in different combinations are used. We here report five male patients of nodular scabies, aged between 14 and 25 years, who had classical scabies that had been cured by sulfur ointment for at least 4 weeks except for their itching nodules, and their residual pruritic nodules also failed in previous treatments including antihistamines, topical applying and intralesional injection of steroids as well as topical tacrolimus in different combinations before being recruited to this study. The patients were administered tofacitinib 5 mg, twice a day, which led to excellent and rapid improvement for both lesions and symptoms after 1-4 weeks of treatment, respectively, without any associations. During 6 months of follow-up, only one had re-infection of scabies associated with nodules that were cured by sulfur ointment and tofacitinib again. No adverse reaction was observed. The present results suggested that tofacitinib might be a potential agent for nodular scabies with excellent response.

Association between regular physical activity and biomarker changes in early Parkinson's disease patients.

INTRODUCTION: Physical activity benefits patients with Parkinson's disease (PD) and is assumed to possess disease-modifying potential. PD-related biomarkers, such as dopamine transporter (DAT) imaging and cerebrospinal fluid (CSF) α-synuclein (α-syn) and amyloid ß (Aß), correlate with disease severity and, to some extent, reflect disease progression and pathology. However, the association between regular physical activity and PD biomarker changes remains unknown. This study aimed to investigate the association between physical activity and longitudinal trajectories of PD biomarkers. METHODS: This retrospective study included 444 patients with a median follow-up time of 5 years from the Parkinson's Progression Markers Initiative cohort. Data collection included physical activity as scaled by the Physical Activity Scale for the Elderly questionnaire, dopamine transporter imaging, CSF assessment, and serum biomarkers. We analyzed the data using a linear mixed regression model. RESULTS: Regular physical activity was associated with a slower decline of DAT uptake in the caudate (ß = 0.063, p = 0.011) and the putamen (ß = 0.062, p = 0.023). No association was detected between regular physical activity and CSF, as well as serum biomarkers. CONCLUSION: Regular physical activity is associated with favorable PD biomarker progression, indicating a potential disease-modifying effect.

Association between regular physical activity and biomarker changes in early Parkinson's disease patients.

INTRODUCTION: Physical activity benefits patients with Parkinson's disease (PD) and is assumed to possess disease-modifying potential. PD-related biomarkers, such as dopamine transporter (DAT) imaging and cerebrospinal fluid (CSF) α-synuclein (α-syn) and amyloid ß (Aß), correlate with disease severity and, to some extent, reflect disease progression and pathology. However, the association between regular physical activity and PD biomarker changes remains unknown. This study aimed to investigate the association between physical activity and longitudinal trajectories of PD biomarkers. METHODS: This retrospective study included 444 patients with a median follow-up time of 5 years from the Parkinson's Progression Markers Initiative cohort. Data collection included physical activity as scaled by the Physical Activity Scale for the Elderly questionnaire, dopamine transporter imaging, CSF assessment, and serum biomarkers. We analyzed the data using a linear mixed regression model. RESULTS: Regular physical activity was associated with a slower decline of DAT uptake in the caudate (ß = 0.063, p = 0.011) and the putamen (ß = 0.062, p = 0.023). No association was detected between regular physical activity and CSF, as well as serum biomarkers. CONCLUSION: Regular physical activity is associated with favorable PD biomarker progression, indicating a potential disease-modifying effect.

Airborne observations over the North Atlantic Ocean reveal the importance of gas-phase urea in the atmosphere.

Reduced nitrogen (N) is central to global biogeochemistry, yet there are large uncertainties surrounding its sources and rate of cycling. Here, we present observations of gas-phase urea (CO(NH2)2) in the atmosphere from airborne high-resolution mass spectrometer measurements over the North Atlantic Ocean. We show that urea is ubiquitous in the lower troposphere in the summer, autumn, and winter but was not detected in the spring. The observations suggest that the ocean is the primary emission source, but further studies are required to understand the responsible mechanisms. Urea is also observed aloft due to long-range transport of biomass-burning plumes. These observations alongside global model simulations point to urea being an important, and currently unaccounted for, component of reduced-N to the remote marine atmosphere. Airborne transfer of urea between nutrient-rich and -poor parts of the ocean can occur readily and could impact ecosystems and oceanic uptake of carbon dioxide, with potentially important climate implications.