An adult patient with pulmonary arterial hypertension, a NOTCH3 mutation, and leflunomide exposure.

Pulmonary arterial hypertension (PAH) is a poorly understood disease of the small pulmonary arteries. Pulmonary vascular remodeling and progressively rising pulmonary vascular resistance are hallmarks of the disease that ultimately result in right heart failure. Several genetic mutations, most notably in bone morphogenetic protein receptor type 2, have a causal association with heritable forms of PAH. Mutations in neurogenic locus notch homolog protein 3 (NOTCH3) have been reported in adults and children with PAH, but whether NOTCH3 is causally associated with PAH is debated. With this case report, we describe the clinical characteristics, comorbidities, and exposure history of an adult patient with PAH and multiple sclerosis who was found to have a NOTCH3 missense mutation and exposure to leflunomide.

Poor Cardiac Output Reserve in Pulmonary Arterial Hypertension is Associated With Right Ventricular Stiffness and Impaired Interventricular Dependence.

BACKGROUND: Pulmonary arterial hypertension is characterized by poor exercise tolerance. The contribution of right ventricular (RV) diastolic function to the augmentation of cardiac output during exercise is not known. This study leverages pressure-volume (p-V) loop analysis to characterize the impact of RV diastology on poor flow augmentation during exercise in PAH. METHODS: RV p-V loops were measured in 41 PAH patients at rest and during supine bike exercise. Patients were stratified by median change in cardiac index during exercise into two groups: high and low CI reserve. Indices of diastolic function (end-diastolic elastance, Eed) and ventricular interdependence (left ventricular transmural pressure, LVTMP) were compared at matched exercise stages. RESULTS: Compared to patients with high CI reserve, those with low reserve exhibited lower exercise stroke volume (36 versus 49 ml·m-2, p=0.0001), with higher associated exercise afterload (Ea 1.76 versus 0.90 mmHg·mL-1, p<0.0001), RV stiffness (Eed 0.68 versus 0.26 mmHg·mL-1, p=0.003), and right-sided pressures (RA 14 versus 8 mmHg, p=0.002). Higher right-sided pressures led to significantly lower LV filling among the low CI reserve subjects (LVTMP -4.6 versus 3.2 mmHg, p=0.0001). Interestingly, low exercise flow reserve correlated significantly with high afterload and RV stiffness, but not with RV contractility nor RV-PA coupling. CONCLUSIONS: Patients with poor exercise CI reserve exhibit poor exercise RV afterload, stiffness, and right-sided filling pressures that depress LV filling and stroke work. High afterload and RV stiffness were the best correlates to low flow reserve in PAH. Exercise unmasked significant pathophysiologic PAH differences unapparent at rest.

Collagen 18A1/Endostatin Expression in the Progression of Right Ventricular Remodeling and Dysfunction in Pulmonary Arterial Hypertension.

Numerous studies have demonstrated that endostatin (ES), a potent angiostatic peptide derived from collagen type XVIII alpha 1 chain and encoded by COL18A1, is elevated in pulmonary arterial hypertension (PAH). Importantly, elevated ES has consistently been associated with altered hemodynamics, poor functional status, and adverse outcomes in adult and pediatric PAH. This study used serum samples from patients with Group I PAH and plasma and tissue samples derived from the Sugen/Chronic hypoxic (SuHx) rat pulmonary hypertension (PH) model to define associations between COL18A1/ES and disease development, including hemodynamics, right ventricular (RV) remodeling, and RV dysfunction. Using cardiac magnetic resonance (CMR) imaging and advanced hemodynamic assessments with pressure-volume (PV) loops in patients with PAH to assess RV-pulmonary arterial (PA) coupling, we observed a strong relationship between circulating ES levels and metrics of RV structure and function. Specifically, RV mass and the ventricular mass index (VMI) were positively associated with ES while RV ejection fraction and RV-PA coupling were inversely associated with ES levels. Our animal data demonstrates that the development of PH is associated with increased COL18A1/ES in the heart as well as the lungs. Disease-associated increases in COL18A1 mRNA and protein were most pronounced in the RV compared to the left ventricle (LV) and lung. COL18A1 expression in the RV was strongly associated with disease-associated changes in RV mass, fibrosis, and myocardial capillary density. These findings indicate that COL18A1/ES increase early in disease development in the RV and implicate COL18A1/ES in pathologic RV dysfunction in PAH.

Chinese hamster ovary cell line engineering strategies for modular production of custom extracellular vesicles.

Continuously secreted by all cell types, extracellular vesicles (EVs) are small membrane-bound structures which shuttle bioactive cargo between cells across their external environment. Their central role as natural molecular messengers and ability to cross biological barriers has garnered significant attention in the use of EVs as therapeutic delivery vehicles. Still, harnessing the potential of EVs is faced with many obstacles. A cell line engineering approach can be used to exploit EVs to encapsulate a bespoke cargo of interest. However, full details regarding native EV-loading mechanisms remain under debate, making this a challenge. While Chinese hamster ovary (CHO) cells are well known to be the preferred host for recombinant therapeutic protein production, their application as an EV producer cell host has been largely overlooked. In this study, we engineered CHO DG44 cells to produce custom EVs with bespoke cargo. To this end, genetic constructs employing split green fluorescent protein technology were designed for tagging both CD81 and protein cargoes to enable EV loading via self-assembling activity. To demonstrate this, NanoLuc and mCherry were used as model reporter cargoes to validate engineered loading into EVs. Experimental findings indicated that our custom EV approach produced vesicles with up to 15-fold greater cargo compared with commonly used passive loading strategies. When applied to recipient cells, we observed a dose-dependent increase in cargo activity, suggesting successful delivery of engineered cargo via our custom CHO EVs.

Growth of Romaine Lettuce in Eggshell Powder Mixed Alginate Hydrogel in an Aeroponic System for Water Conservation and Vitamin C Biofortification.

Vitamin C is crucial for physical well-being, and its deficiency can lead to severe health consequences. Biofortification has been used to address this deficiency by enhancing vitamin C in plants. Additionally, soilless agriculture has been used to conserve and optimize water use in comparison to conventional agriculture. While hydrogels have been shown to improve water conservation and are used for biofortification in crops, their application has only been explored in soil-based and hydroponic farming. The aeroponics system is a plant-growing method that has shown potential for increasing yields and biomass while conserving water and nutrients. In this paper, we have developed an aeroponic-compatible medium to grow romaine lettuce (Lactuca sativa L.) with eggshell powder (ESP) mixed with calcium-alginate hydrogel as a substrate and nutrient source aiming to conserve water and incorporate vitamin C through biofortification. Herein, lower water spray time and higher intervals, with varied gel types and ESP concentrations, resulted in healthy lettuce growth. Plants treated with 0.5% ascorbic acid-absorbed ESP-mixed alginate hydrogel for biofortification showed higher levels of vitamin C compared to the traditional method. This study suggests using an alginate hydrogel-ESP-based substrate in aeroponics to reduce water usage and enhance plant biofortification of vitamin C.

Aberrant long-chain fatty acid metabolism associated with evolving systemic sclerosis-associated pulmonary arterial hypertension.

We sought to investigate differential metabolism in patients with systemic sclerosis (SSc) who develop pulmonary arterial hypertension (PAH) versus those who do not, as a method of identifying potential disease biomarkers. In a nested case-control design, serum metabolites were assayed in SSc subjects who developed right heart catheterization-confirmed PAH (n = 22) while under surveillance in a longitudinal cohort from Johns Hopkins, then compared with metabolites assayed in matched SSc patients who did not develop PAH (n = 22). Serum samples were collected at "proximate" (within 12 months) and "distant" (within 1-5 yr) time points relative to PAH diagnosis. Metabolites were identified using liquid chromatography-mass spectroscopy (LC-MS). An LC-MS dataset from SSc subjects with either mildly elevated pulmonary pressures or overt PAH from the University of Michigan was compared. Differentially abundant metabolites were tested as predictors of PAH in two additional validation SSc cohorts. Long-chain fatty acid metabolism (LCFA) consistently differed in SSc-PAH versus SSc without PH. LCFA metabolites discriminated SSc-PAH patients with mildly elevated pressures in the Michigan cohort and predicted SSc-PAH up to 2 yr before clinical diagnosis in the Hopkins cohort. Acylcholines containing LCFA residues and linoleic acid metabolites were most important for discriminating SSc-PAH. Combinations of acylcholines and linoleic acid metabolites provided good discrimination of SSc-PAH across cohorts. Aberrant lipid metabolism is observed throughout the evolution of PAH in SSc. Lipidomic signatures of abnormal LCFA metabolism distinguish SSc-PAH patients from those without PH, including before clinical diagnosis and in mild disease.NEW & NOTEWORTHY Abnormal lipid metabolism is evident across time in the development of SSc-PAH, and dysregulated long-chain fatty acid metabolism predicts overt PAH.

Financial Incentives for Physical Activity and Sports Participation in Young People.

Physical inactivity is a global health problem. Childhood is an opportune time to establish healthy physical activity behaviors, including the participation in organized physical activity, such as sports. We hypothesize that financial incentives can improve young people's participation in physical activity and sports. The design of the incentive and the context in which it operates are crucial to its success.

Application of Metabolomics across the Spectrum of Pulmonary and Critical Care Medicine.

In recent years, metabolomics, the systematic study of small-molecule metabolites in biological samples, has yielded fresh insights into the molecular determinants of pulmonary diseases and critical illness. The purpose of this article is to orient the reader to this emerging field by discussing the fundamental tenets underlying metabolomics research, the tools and techniques that serve as foundational methodologies, and the various statistical approaches to analysis of metabolomics datasets. We present several examples of metabolomics applied to pulmonary and critical care medicine to illustrate the potential of this avenue of research to deepen our understanding of pathophysiology. We conclude by reviewing recent advances in the field and future research directions that stand to further the goal of personalizing medicine to improve patient care.

A Three Delays theoretical framework to describe social determinants as barriers to dental care.

OBJECTIVES: The Three Delays model is a well-established global public health framework for the utilization of obstetric services where each delay represents a series of factors affecting utilization: (1) Delay #1-Deciding to seek care, (2) Delay #2-Reaching an appropriate facility and (3) Delay #3-Receiving adequate care. The aim of this qualitative study was to explore the application of the Three Delays model to dental service utilization and describe factors attributed to delayed utilization within this framework. METHODS: This study utilized a framework analysis, underpinned by the Three Delays model, to examine delays in dental care utilization. A criterion purposive sample of English-speaking adults (18+ years) in Massachusetts and Florida, USA with limited dental care access was recruited. Data were collected via semi-structured interviews conducted in two phases: 17 individual interviews, followed by interviews with a subset of five participants over 3 months (a total of 18 interviews). The analysis involved inductive thematic coding and systematic organization within the framework. RESULTS: Major themes and subthemes were constructed from the participants' narratives, identified and categorized as factors in the Three Delays framework. Each of the delays was interrelated to the other two, and Delay #1 was the most common delay based on the participants' interviews. The themes and subthemes contributing to one or more delays included interpersonal communication, prior dental experience, financial considerations, childcare costs, social connection, technology literacy, time constraints, competing priorities, stressors such as eviction and immigration status and microaggressions including racism and stigma. CONCLUSION: The Three Delays model was applicable to the study of dental care utilization and factors that impact the decision to seek dental care, reaching an appropriate dental facility and receiving adequate dental care in this study context.

Fatty acid metabolism promotes TRPV4 activity in lung microvascular endothelial cells in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a morbid disease characterized by significant lung endothelial cell (EC) dysfunction. Prior work has shown that microvascular endothelial cells (MVECs) isolated from animals with experimental PAH and patients with PAH exhibit significant abnormalities in metabolism and calcium signaling. With regards to metabolism, we and others have shown evidence of increased aerobic glycolysis and evidence of increased utilization of alternate fuel sources (such as fatty acids) in PAH EC. In the realm of calcium signaling, our prior work linked increased activity of the transient receptor potential vanilloid-4 (TRPV4) channel to increased proliferation of MVECs isolated from the Sugen/Hypoxia rat model of PAH (SuHx-MVECs). However, the relationship between metabolic shifts and calcium abnormalities was not clear. Specifically, whether shifts in metabolism were responsible for increasing TRPV4 channel activity in SuHx-MVECs was not known. In this study, using human data, serum samples from SuHx rats, and SuHx-MVECs, we describe the consequences of increased MVEC fatty acid oxidation in PAH. In human samples, we observed an increase in long-chain fatty acid levels that was associated with PAH severity. Next, using SuHx rats and SuHx-MVECs, we observed increased intracellular levels of lipids. We also show that increasing intracellular lipid content increases TRPV4 activity, whereas inhibiting fatty acid oxidation normalizes basal calcium levels in SuHx-MVECs. By exploring the fate of fatty acid-derived carbons, we observed that the metabolite linking increased intracellular lipids to TRPV4 activity was ß-hydroxybutyrate (BOHB), a product of fatty acid oxidation. Finally, we show that BOHB supplementation alone is sufficient to sensitize the TRPV4 channel in rat and mouse MVECs. Returning to humans, we observe a transpulmonary BOHB gradient in human patients with PAH. Thus, we establish a link between fatty acid oxidation, BOHB production, and TRPV4 activity in MVECs in PAH. These data provide new insight into metabolic regulation of calcium signaling in lung MVECs in PAH.NEW & NOTEWORTHY In this paper, we explore the link between metabolism and intracellular calcium levels in microvascular endothelial cells (MVECs) in pulmonary arterial hypertension (PAH). We show that fatty acid oxidation promotes sensitivity of the transient receptor potential vanilloid-4 (TRPV4) calcium channel in MVECs isolated from a rodent model of PAH.

Simultaneous biofortification of vitamin C and mineral nutrients in arugula microgreens.

Microgreens have shown promise in improving the overall nutritional value of diets due to their high nutrient density. Agronomic biofortification, is an efficient strategy for enhancing the nutritional value of crops, including microgreens. This study aimed to biofortify vitamin C and other essential nutrients in arugula microgreens using four treatments containing 0.25 % ascorbic acid, pH adjusted with different bases: KOH, Ca(OH)2, ZnCO3, or NaOH and a deionized water control. The results indicate that ascorbic acid-treated microgreens had more vitamin C, greater fresh weight and % dry matter than the control. The ascorbic acid + Zn treatment had an 135 % average increase in vitamin C compared to the control. Microgreens treated with ascorbic acid also showed increased levels of minerals that are present in the nutrient solution, such as potassium, sodium, calcium, and zinc. This research contributes to the growing interest in microgreens biofortification and their role in addressing multi-nutrient deficiencies.

A decade of improving nutritional quality of horticultural crops agronomically (2012-2022): A systematic literature review.

The ultimate goal of world crop production is to produce more with less to meet the growing population demands. However, concentrating solely on increased quantity of production often impacts the quality of produce. Consumption of crops or foods that do not meet nutritional or dietary needs can lead to malnutrition. Malnutrition and undernutrition are prevalent in a significant portion of the population. Agronomic biofortification of minerals and vitamins in horticultural crops has emerged as a promising approach to address nutrient deficiencies and enhance the nutritional quality of food. Despite numerous research papers on plant nutrient biofortification, there remains a lack of systematic reviews that comprehensively summarize the latest knowledge on this topic. Herein we discuss different agronomic ways to biofortify several horticultural crops over the past decade. This systematic review aims to fill this gap by presenting various methodologies and comparing the outcomes of these methods in respect to nutrient content in plant parts. The review focuses on original research papers collected from various scientific databases including Scopus and Web of Knowledge, covering the most recent literature from the last ten years (2012-2022) for specific studies on the agronomic biofortification macronutrients, micronutrients, and vitamins in horticultural plants with exclusion of certain criteria such as 'genetic,' 'breeding,' and 'agronomic crops.' This review critically analyzes the current state of research and explores prospects for the future in this field. The biofortification of various minerals and vitamins, including calcium, selenium, iodine, B vitamins, vitamin A, and vitamin C, are examined, highlighting the achievements and limitations of existing studies. In conclusion, agronomic biofortification of minerals and vitamins in horticultural crops with further research offers a promising approach to address nutrient deficiencies and improve the nutritional quality of food.

Kynurenine pathway metabolism evolves with development of preclinical and scleroderma-associated pulmonary arterial hypertension.

Understanding metabolic evolution underlying pulmonary arterial hypertension (PAH) development may clarify pathobiology and reveal disease-specific biomarkers. Patients with systemic sclerosis (SSc) are regularly surveilled for PAH, presenting an opportunity to examine metabolic change as disease develops in an at-risk cohort. We performed mass spectrometry-based metabolomics on longitudinal serum samples collected before and near SSc-PAH diagnosis, compared with time-matched SSc subjects without PAH, in a SSc surveillance cohort. We validated metabolic differences in a second cohort and determined metabolite-phenotype relationships. In parallel, we performed serial metabolomic and hemodynamic assessments as the disease developed in a preclinical model. For differentially expressed metabolites, we investigated corresponding gene expression in human and rodent PAH lungs. Kynurenine and its ratio to tryptophan (kyn/trp) increased over the surveillance period in patients with SSc who developed PAH. Higher kyn/trp measured two years before diagnostic right heart catheterization increased the odds of SSc-PAH diagnosis (OR 1.57, 95% CI 1.05-2.36, P = 0.028). The slope of kyn/trp rise during SSc surveillance predicted PAH development and mortality. In both clinical and experimental PAH, higher kynurenine pathway metabolites correlated with adverse pulmonary vascular and RV measurements. In human and rodent PAH lungs, expression of TDO2, which encodes tryptophan 2,3 dioxygenase (TDO), a protein that catalyzes tryptophan conversion to kynurenine, was significantly upregulated and tightly correlated with pulmonary hypertensive features. Upregulated kynurenine pathway metabolism occurs early in PAH, localizes to the lung, and may be modulated by TDO2. Kynurenine pathway metabolites may be candidate PAH biomarkers and TDO warrants exploration as a potential novel therapeutic target.NEW & NOTEWORTHY Our study shows an early increase in kynurenine pathway metabolism in at-risk subjects with systemic sclerosis who develop pulmonary arterial hypertension (PAH). We show that kynurenine pathway upregulation precedes clinical diagnosis and that this metabolic shift is associated with increased disease severity and shorter survival times. We also show that gene expression of TDO2, an enzyme that generates kynurenine from tryptophan, rises with PAH development.

Treating acute exacerbations of COPD with Chinese herbal medicine to aid antibiotic use reduction (Excalibur): a randomised double-blind, placebo-controlled feasibility trial.

Background: Although many acute exacerbations of COPD (AECOPD) are triggered by non-bacterial causes, they are often treated with antibiotics. Preliminary research suggests that the Chinese herbal medicine "Shufeng Jiedu" (SFJD), may improve recovery and therefore reduce antibiotic use in patients with AECOPD. Aims: To assess the feasibility of conducting a randomised placebo-controlled clinical trial of SFJD for AECOPD in UK primary care. Methods: GPs opportunistically recruited patients experiencing an AECOPD. Participants were randomised 1:1 to usual care plus SFJD or placebo for 14 days. Participants, GPs and research nurses were blinded to treatment allocation. GPs could prescribe immediate, delayed or no antibiotics, with delayed prescribing encouraged where appropriate. Participants were asked to complete a participant diary, including EXACT-PRO and CAT™ questionnaires for up to 4 weeks. Outcomes included recruitment rate and other measures of study feasibility described using only descriptive statistics and with no formal comparisons between groups. We also conducted qualitative interviews with recruited and non-recruited COPD patients and clinicians, analysed using framework analysis. Results: Over 6 months, 19 participants (6 SFJD, 13 placebo) were recruited. Sixteen (84%) participants returned diaries or provided a diary by recall. Overall, 1.3 participants were recruited per 1,000 patients on the COPD register per month open. Median duration of treatment was 9.8 days in the intervention group vs 13.3 days in the placebo group. The main reason for discontinuation in both groups was perceived side-effects. in both groups. Point estimates for both the EXACT-PRO and CAT™ outcomes suggested possible small benefits of SFJD. Most patients and clinicians were happy to try SFJD as an alternative to antibiotics for AECOPD. Recruitment was lower than expected because of the short recruitment period, the lower incidence of AECOPD during the COVID-19 pandemic, patients starting antibiotics from "rescue packs" before seeing their GP, and workforce challenges in primary care. Conclusion: Recruitment was impaired by the COVID-19 pandemic. Nevertheless, we were able to demonstrate the feasibility of recruiting and randomising participants and identified approaches to address recruitment challenges such as including the trial medication in COPD patients' "rescue packs" and delegating recruitment to a central trials team. Clinical Trial Registration: Identifier, ISRCTN26614726.

Feasibility of home administration of nebulised interferon ß-1a (SNG001) for COVID-19: a remote study.

BACKGROUND: Effective therapeutics given early to high-risk ambulatory patients with coronavirus disease 2019 (COVID-19) could improve outcomes and reduce overall healthcare burden. However, conducting site visits in non-hospitalised patients, who should remain isolated, is problematic. AIM: To evaluate the feasibility of a purely remote (virtual) study in non-hospitalised patients with COVID-19; and the efficacy and safety of nebulised recombinant interferon-ß1a (SNG001) in this setting. DESIGN & SETTING: Randomised, double-blind, parallel-group study, which was conducted remotely. METHOD: Eligible patients aged ≥65 years (or ≥50 years with risk factors) with COVID-19 and not requiring hospital admission were recruited remotely. They were randomised to SNG001 or placebo once-daily via nebuliser for 14 days. The main outcomes were assessments of feasibility and safety, which were all conducted remotely. RESULTS: Of 114 patients treated, 111 (97.4%) completed 28 days of follow-up. Overall compliance to study medication was high, with ≥13 doses taken by 89.7% and 92.9% of treated patients in the placebo and SNG001 groups, respectively. Over the course of the study, only two patients were hospitalised, both in the placebo group; otherwise there were no notable differences between treatments for the efficacy parameters. No patients withdrew owing to an adverse event, and a similar proportion of patients experienced on-treatment adverse events in the two treatment groups (64.3% and 67.2% with SNG001 and placebo, respectively); most were mild or moderate and not treatment-related. CONCLUSION: This study demonstrated that it is feasible to conduct a purely virtual study in community-based patients with COVID-19, when the study included detailed daily assessments and with medication administered via nebuliser.

Low-affinity insulin-like growth factor binding protein 7 and its association with pulmonary arterial hypertension severity and survival.

Insulin-like growth factor (IGF) binding proteins (IGFBPs) are a family of growth factor modifiers, some of which are known to be independently associated with pulmonary arterial hypertension (PAH) survival. IGF factor binding protein 7 (IGFBP7) is a unique low-affinity IGFBP that, independent of IGF, stimulates prostacyclin production. This study proposed to establish associations between IGFBP7 and PAH severity and survival, using enrollment and longitudinal samples. Serum IGFBP7 levels were significantly elevated in patients with PAH compared to controls. After adjusting for age and sex, logarithmic increases in IGFBP7 were associated with a 20 m shorter six-minute walk distance (6MWD; p < 0.001), a 2-3 mmHg higher mean right atrial pressure (p < 0.001 and 0.02), and a higher likelihood of a greater REVEAL 2.0 risk category placement (p < 0.001). Kaplan-Meier analysis demonstrated significantly decreased survival with IGFBP7 above the median and Cox multivariable analysis adjusted for age and sex, demonstrated higher serum IGFBP7 was an independent predictor of survival. Though the exact mechanism is still unknown, given IGFBP7's role as a prostacyclin stimulant, it has potential use as a therapeutic target for disease modulation.

Uptake of a Universal Sports Subsidy Program for School-Aged Children: A Population Data Analysis.

BACKGROUND: Around 40% of Australian children do not participate in sport. Cost is a major barrier to participation, particularly for children from low socioeconomic backgrounds. This study aimed to evaluate the uptake of a population-level children's sports subsidy scheme, including sociodemographic differences in uptake. METHODS: A state-wide cross-sectional analysis comparing sports voucher claimants (primary school-aged children with a valid Medicare or Australian visa number) from the 2019 financial year with population census data from South Australia. Chi-square was used to examine whether the percentage of eligible children who claimed a voucher differed based on age, sex, socioeconomic status (SES), and geographical remoteness. Subgroup analyses were conducted for the lowest 2 socioeconomic disadvantage deciles, split by gender. Scatterplots were used to compare sports between high and low SES children. RESULTS: A total of 74,668 children claimed sports vouchers (45.5% of eligible children). Children who were relatively younger, female, from low socioeconomic backgrounds, and from major cities were least likely to claim the voucher. The 5 most common sports were Australian rules football (30.2%), netball (13.6%), soccer (13.1%), gymnastics (10.4%), and basketball (5.7%), with the popular sports similar for high and low SES children. CONCLUSIONS: Future work is needed to understand how Sports Voucher, and sport participation rates have changed over time, and to improve voucher uptake among girls, city dwellers, and low SES children.

Leaf structural traits mediating pre-existing physical innate resistance to sorghum aphid in sorghum under uninfested conditions.

KEY MESSAGE: We found four indicative traits of innate immunity. Sorghum-resistant varieties had a greater trichome, stomatal and chloroplast density, and smaller mesophyll intercellular width than susceptible varieties. The sorghum aphid (SA), Melanaphis sorghi (Theobald), can severely reduce sorghum yield. The contribution of structural traits to SA resistance has not been extensively studied. Moreover, the current screening method for resistance is inherently subjective for resistance and requires infestation in plants. Quantifying the microanatomical basis of innate SA resistance is crucial for developing reliable screening tools requiring no infestation. The goal of this study was to identify structural traits linked to physical innate SA resistance in sorghum. We conducted controlled environment and field experiments under no SA infestation conditions, with two resistant (R. LBK1 and R. Tx2783) and two susceptible (R. Tx7000 and R. Tx430) varieties. Leaf tissues collected at the fifth leaf stage in the controlled environment experiment were analyzed for the epidermal and mesophyll traits using light and transmission electron microscopy. Leaf tissues collected at physiological maturity in the field experiment were analyzed for surface traits using scanning electron microscopy. Our results showed that stomatal density, trichome density, trichome length, and chloroplast density are key leaf structural traits indicative of physical innate SA resistance. We found that resistant varieties had a greater density of trichomes (39%), stomata (31%), and chloroplast (42%), and smaller mesophyll intercellular width (- 52%) than susceptible varieties. However, the chloroplast, mitochondria, and epidermal cell ultrastructural traits were ineffective indicators of SA resistance. Our findings provide the foundation for developing an objective high-throughput method for SA resistance screening. We suggest a follow-up validation experiment to confirm our outcomes under SA infestation conditions.

Spatial and temporal resolution of metabolic dysregulation in the Sugen hypoxia model of pulmonary hypertension.

Although PAH is partially attributed to disordered metabolism, previous human studies have mostly examined circulating metabolites at a single time point, potentially overlooking crucial disease biology. Current knowledge gaps include an understanding of temporal changes that occur within and across relevant tissues, and whether observed metabolic changes might contribute to disease pathobiology. We utilized targeted tissue metabolomics in the Sugen hypoxia (SuHx) rodent model to investigate tissue-specific metabolic relationships with pulmonary hypertensive features over time using regression modeling and time-series analysis. Our hypotheses were that some metabolic changes would precede phenotypic changes, and that examining metabolic interactions across heart, lung, and liver tissues would yield insight into interconnected metabolic mechanisms. To support the relevance of our findings, we sought to establish links between SuHx tissue metabolomics and human PAH -omics data using bioinformatic predictions. Metabolic differences between and within tissue types were evident by Day 7 postinduction, demonstrating distinct tissue-specific metabolism in experimental pulmonary hypertension. Various metabolites demonstrated significant tissue-specific associations with hemodynamics and RV remodeling. Individual metabolite profiles were dynamic, and some metabolic shifts temporally preceded the emergence of overt pulmonary hypertension and RV remodeling. Metabolic interactions were observed such that abundance of several liver metabolites modulated lung and RV metabolite-phenotype relationships. Taken all together, regression analyses, pathway analyses and time-series analyses implicated aspartate and glutamate signaling and transport, glycine homeostasis, lung nucleotide abundance, and oxidative stress as relevant to early PAH pathobiology. These findings offer valuable insights into potential targets for early intervention in PAH.

Metabolomic Differences in Connective Tissue Disease-Associated Versus Idiopathic Pulmonary Arterial Hypertension in the PVDOMICS Cohort.

OBJECTIVE: Patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) experience worse survival and derive less benefit from pulmonary vasodilator therapies than patients with idiopathic PAH (IPAH). We sought to identify differential metabolism in patients with CTD-PAH versus patients with IPAH that might underlie these observed clinical differences. METHODS: Adult participants with CTD-PAH (n = 141) and IPAH (n = 165) from the Pulmonary Vascular Disease Phenomics (PVDOMICS) study were included. Detailed clinical phenotyping was performed at cohort enrollment, including broad-based global metabolomic profiling of plasma samples. Participants were followed prospectively for ascertainment of outcomes. Supervised and unsupervised machine learning algorithms and regression models were used to compare CTD-PAH versus IPAH metabolomic profiles and to measure metabolite-phenotype associations and interactions. Gradients across the pulmonary circulation were assessed using paired mixed venous and wedged samples in a subset of 115 participants. RESULTS: Metabolomic profiles distinguished CTD-PAH from IPAH, with patients with CTD-PAH demonstrating aberrant lipid metabolism with lower circulating levels of sex steroid hormones and higher free fatty acids (FAs) and FA intermediates. Acylcholines were taken up by the right ventricular-pulmonary vascular (RV-PV) circulation, particularly in CTD-PAH, while free FAs and acylcarnitines were released. In both PAH subtypes, dysregulated lipid metabolites, among others, were associated with hemodynamic and RV measurements and with transplant-free survival. CONCLUSIONS: CTD-PAH is characterized by aberrant lipid metabolism that may signal shifted metabolic substrate utilization. Abnormalities in RV-PV FA metabolism may imply a reduced capacity for mitochondrial beta oxidation within the diseased pulmonary circulation.