Lung Epithelium Releases Growth Differentiation Factor 15 in Response to Pathogen-mediated Injury.

GDF15 (growth differentiation factor 15) is a stress cytokine with several proposed roles, including support of stress erythropoiesis. Higher circulating GDF15 levels are prognostic of mortality during acute respiratory distress syndrome, but the cellular sources and downstream effects of GDF15 during pathogen-mediated lung injury are unclear. We quantified GDF15 in lower respiratory tract biospecimens and plasma from patients with acute respiratory failure. Publicly available data from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were reanalyzed. We used mouse models of hemorrhagic acute lung injury mediated by Pseudomonas aeruginosa exoproducts in wild-type mice and mice genetically deficient for Gdf15 or its putative receptor, Gfral. In critically ill humans, plasma levels of GDF15 correlated with lower respiratory tract levels and were higher in nonsurvivors. SARS-CoV-2 infection induced GDF15 expression in human lung epithelium, and lower respiratory tract GDF15 levels were higher in coronavirus disease (COVID-19) nonsurvivors. In mice, intratracheal P. aeruginosa type II secretion system exoproducts were sufficient to induce airspace and plasma release of GDF15, which was attenuated with epithelial-specific deletion of Gdf15. Mice with global Gdf15 deficiency had decreased airspace hemorrhage, an attenuated cytokine profile, and an altered lung transcriptional profile during injury induced by P. aeruginosa type II secretion system exoproducts, which was not recapitulated in mice deficient for Gfral. Airspace GDF15 reconstitution did not significantly modulate key lung cytokine levels but increased circulating erythrocyte counts. Lung epithelium releases GDF15 during pathogen injury, which is associated with plasma levels in humans and mice and can increase erythrocyte counts in mice, suggesting a novel lung-blood communication pathway.

External validation of the SYNTAX score II 2020 in patients with chronic renal insufficiency.

BACKGROUND: The SYNTAX score Ⅱ 2020 (SSⅡ-2020) was created as a customized decision-making tool for individuals diagnosed with complex coronary artery disease (CAD). Nevertheless, there has been a scarcity of research investigating the long-term predictive significance of SSⅡ-2020 for patients with both CAD and chronic renal insufficiency (CRI) who undergo percutaneous coronary intervention (PCI). AIMS: We sought to showcase the prognostic capacity of SSII-2020 in evaluating long-term all-cause mortality (ACM) within this high-risk patient cohort. METHODS: A retrospective cohort comprising 1156 individuals diagnosed with CRI and exhibiting left main CAD, three-vessel CAD or both was included in this investigation. We categorized participants into three groups based on the optimal SSII-2020 threshold for predicting long-term ACM, determined using the X-tile software. RESULTS: At the median follow-up duration of 6.3 years, the ACM rates were determined to be 10% in the low, 17% in the moderate, and 28% in the high SSII-2020 groups (p < 0.001). Employing multivariate Cox regression analysis, it was observed that the high SSII-2020 group exhibited a 3.289-fold increased risk of ACM (95% confidence interval [CI]: 2.229-4.856, p < 0.001) compared with the low SSII-2020 group, whereas the high SSII-2020 group displayed a 1.757-fold (95% CI: 1.190-2.597, p = 0.005) in comparison to the median SSII-2020 groups. Compared with SSII, the SSII-2020 had an incremental value for predicting 7-year ACM (C-index: 0.662 vs. 0.534, p = 0.007; IDI: 0.016, p < 0.001). CONCLUSIONS: SSII-2020 enhances long-term ACM prediction, facilitates improved risk stratification, and improves clinical utility for PCI patients with complex CAD and CRI.

Research on collaborative development mechanism of multiple stakeholders in medical institutions based on rough set.

Reducing doctor-patient conflict is an important part of coordinating doctor-patient disputes and easing doctor-patient relationship, which is conducive to building a harmonious medical environment and promoting the healthy development of medical undertakings. This paper constructs a multi-decision-maker mixed conflict model based on rough set theory, puts forward the matrix operation expression of the conflict degree theory in the Pawlak model, and gives a more objective and scientific evaluation function. Combined with hot issues of doctor-patient conflict, the proposed multi-decision-maker mixed conflict model is applied to doctor-patient conflict, examines the doctor-patient relationship in the medical institution system from multiple internal perspectives, and calculates feasible solutions in the conflict system. The results show that high medical quality, high standardize medication, high institutional efficiency, high staff efficiency, high hospital benefits, high hospital revenue, medium employee development, medium equipment development, or high medical quality, high standardize medication, high institutional efficiency, medium staff efficiency, medium hospital benefits, high hospital revenue, high employee development, and high equipment development are important conditions for building a harmonious medical environment and reducing doctor-patient conflicts.

Middle-aged and older people's preference for medical-elderly care integrated institutions in China: a discrete choice experiment study.

BACKGROUND: With the continuing impact of the aging population, medical-elderly care integrated institutions, as a way to bear the pressure of medical and elderly care, effectively ensure the quality of life of the elderly in their later years. OBJECTIVES: To explore the preferences of medical-elderly care integrated institutions among Chinese middle-aged and older people and to provide a reference for establishing elderly-oriented development of medical-elderly care integrated institutions. METHODS: In this study, a discrete choice experiment (DCE) was used to investigate the preferences of people aged 45 years and older in medical-elderly care integrated institutions in China from October 20, 2022, to November 10, 2022. A mixed logit regression model was used to analyze the DCE data. Participants' willingness to pay for each attribute was also calculated. RESULTS: Data from 420 participants who provided valid responses were included in the analysis. In terms of the choice preference, moderate service quality (vs. poor service quality: ß = 1.707, p < 0.001, 95% CI 1.343 ~ 2.071) and high medical technology level (vs. low medical technology level: ß = 1.535, p < 0.001, 95% CI 1.240 ~ 1.830) were the most important attributes to middle-aged and older people, followed by monthly cost, environmental facilities, the convenience of transportation, and entertainment activities. Regarding the willingness to pay, participants were more willing to pay for service quality and medical technology level than for other attributes. They were willing to pay $3156 and $2838 more for "poor service quality" and "low medical technology level," respectively, to receive "moderate service quality " (p = 0.007, 95% CI 963 ~ 5349) and "high medical technology level" (p = 0.005, 95% CI 852 ~ 4824). CONCLUSIONS: The state should attach great importance to the development of medical-elderly care integrated services industry, actively optimize the model of the medical-elderly care integrated service, improve the facilities, and create a healthy environment. At the same time, give full play to the role of medical insurance, long-term care insurance, and commercial insurance, so as to improve the comprehensive quality of life of the elderly. PUBLIC CONTRIBUTION: The design of the experimental selection was guided by 10 experts in the field, 5 Chinese government officials, and interviews and focus group discussions, without whose participation this study would not have been possible.

A cross-sectional study: family communication, anxiety, and depression in adolescents: the mediating role of family violence and problematic internet use.

OBJECTIVE: The objective of this study is to explore the relationship between family communication, family violence, problematic internet use, anxiety, and depression and validate their potential mediating role. METHODS: The study population consisted of Chinese adolescents aged 12 to 18 years, and a cross-sectional survey was conducted in 2022. Structural equation models were constructed using AMOS 25.0 software to examine the factors that influence adolescent anxiety and depression and the mediating effects of problematic internet use and family violence. RESULTS: The results indicate that family communication was significantly and negatively related to family violence (ß = -.494, p < 0.001), problematic internet use (ß = -.056, p < .05), depression (ß = -.076, p < .01), and anxiety (ß = -.071, p < .05). And the finds also indicate that family violence mediated the relationships between family communication and depression (ß = -.143, CI: -.198 -.080), and between family communication and anxiety (ß = -.141; CI: -.198 -.074). Chain indirect effects between family communication and depression (ß = -.051; CI: -.081 -.030) or anxiety (ß = -.046; CI: -.080 -.043) via family violence and then through problematic internet use were also found in the present study. CONCLUSIONS: In conclusion, positive family communication is crucial in reducing anxiety and depression in adolescents. Moreover, problematic internet use and family violence mediate the effects of positive family communication on anxiety and depression. Therefore, improving family communication and promoting interventions aimed at reducing family violence and problematic internet use can help reduce anxiety and depression in adolescents, thus promoting their healthy development.

Biomarker interaction selection and disease detection based on multivariate gain ratio.

BACKGROUND: Disease detection is an important aspect of biotherapy. With the development of biotechnology and computer technology, there are many methods to detect disease based on single biomarker. However, biomarker does not influence disease alone in some cases. It's the interaction between biomarkers that determines disease status. The existing influence measure I-score is used to evaluate the importance of interaction in determining disease status, but there is a deviation about the number of variables in interaction when applying I-score. To solve the problem, we propose a new influence measure Multivariate Gain Ratio (MGR) based on Gain Ratio (GR) of single-variate, which provides us with multivariate combination called interaction. RESULTS: We propose a preprocessing verification algorithm based on partial predictor variables to select an appropriate preprocessing method. In this paper, an algorithm for selecting key interactions of biomarkers and applying key interactions to construct a disease detection model is provided. MGR is more credible than I-score in the case of interaction containing small number of variables. Our method behaves better with average accuracy [Formula: see text] than I-score of [Formula: see text] in Breast Cancer Wisconsin (Diagnostic) Dataset. Compared to the classification results [Formula: see text] based on all predictor variables, MGR identifies the true main biomarkers and realizes the dimension reduction. In Leukemia Dataset, the experiment results show the effectiveness of MGR with the accuracy of [Formula: see text] compared to I-score with accuracy [Formula: see text]. The results can be explained by the nature of MGR and I-score mentioned above because every key interaction contains a small number of variables in Leukemia Dataset. CONCLUSIONS: MGR is effective for selecting important biomarkers and biomarker interactions even in high-dimension feature space in which the interaction could contain more than two biomarkers. The prediction ability of interactions selected by MGR is better than I-score in the case of interaction containing small number of variables. MGR is generally applicable to various types of biomarker datasets including cell nuclei, gene, SNPs and protein datasets.

Phenotypic Diversity Caused by Differential Expression of SFTPC-Cre-Transgenic Alleles.

Type II alveolar epithelial cells (AEC2s) play an essential role in the function and maintenance of the pulmonary epithelium. Several transgenic mice have been developed to study the function of these cells in vivo by using the human SFTPC promoter to drive expression of Cre recombinase. The precise activity of each of these transgenic alleles has not been studied, and previous reports suggest that their activity can depend on breeding strategies. We bred mice with a conditional allele of the essential telomere capping protein TRF2 with two different SFTPC-Cre-transgenic strains and observed opposite phenotypes (100% lethality vs. 100% viability). We characterized the Cre recombinase activity in these two transgenic lines and found that the contrasting phenotypes were driven by difference in embryonic expression of the two transgenes, likely due to position effects or differences in the transgenic constructs. We also tested if SFTPC-Cre activity was dependent on maternal or paternal inheritance. When paternally inherited, both SFTPC-Cre alleles produced offspring with constitutive reporter activity independent of the inheritance of the Cre allele, suggesting that Cre recombinase was expressed in the male germline before meiosis. Immunohistochemical analysis of the testis showed reporter activity during spermatogenesis. Analysis of single-cell RNA sequencing data from murine and human testis demonstrated SFTPC expression uniquely during human spermatogenesis, suggesting that use of the human promoter in these constructs is responsible for male germline activity. Our data highlight the importance of careful analysis of transgenic allele activity and identify an SFTPC-Cre allele that is useful for panepithelial targeting in the mouse.

COVID-19 in a patient with long-term use of glucocorticoids: A study of a familial cluster.

Clusters of patients with novel coronavirus disease 2019 (COVID-19) have been successively reported globally. Studies show clear person-to-person transmission. The average incubation period is 2-14 days, and mostly 3-7 days. However, in some patients, this period may be longer. Here, we report a familial cluster of COVID-19 where a 47-year-old woman with long-term use of glucocorticoids did not develop any symptoms within the 14-day quarantine period but was confirmed with COVID-19 by tested positive of antibody on day 40 after she left Wuhan. Almost at the same time, her father and sister were diagnosed with COVID-19. The results suggest that the long-term use of glucocorticoids might cause atypical infections, a long incubation period, and extra transmission of COVID-19.

Propionate enhances the expression of key genes involved in the gluconeogenic pathway in bovine intestinal epithelial cells.

Approximately 15 to 50% of short-chain fatty acids (SCFA) reach the ruminant small intestine. Previous research suggests that activation of small intestinal gluconeogenesis induced by propionate has beneficial effects on energy homeostasis. However, the regulatory effect of propionate on key gluconeogenic genes in enterocytes of the bovine small intestine remains less known. Therefore, the purpose of this study was to establish the long-term cultures of bovine intestinal epithelial cells (BIEC) from bovine jejunum tissue using SV40T (1:200; Santa Cruz, Shanghai, China) and investigate the regulatory effect of propionate on the key gluconeogenic genes in BIEC. Our study showed that long-term BIEC cultures were established by SV40T-induced immortalization. Immortal BIEC were distinguished by the expression of cytokeratin 18, villin, fatty acid binding protein 2, and small intestine peptidase. The mRNA expression of genes involved in the SCFA transporters, monocarboxylate transporter 4, and Na+/H+ exchanger isoforms 1 were significantly elevated with 20 mM SCFA compared with untreated controls. In addition, BIEC exhibited significant uptake of propionate and butyrate from the culture medium. Remarkably, 3 mM propionate induced profound changes in mRNA level of key genes involved in gluconeogenesis, including phosphoenolpyruvate carboxykinase 2, pyruvate carboxylase, fructose-1,6-bisphosphatase 1, and peroxisome proliferator-activated receptor-γ coactivator 1α. Additionally, 3 mM propionate enhanced the expression of PGC1A mRNA at 3, 6, 12, and 24 h of incubation. These findings suggest that propionate controls the mRNA expression of genes involved in key enzymes for gluconeogenesis in the enterocytes of bovines.

GDF15 is an epithelial-derived biomarker of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is the most common and devastating of the interstitial lung diseases. Epithelial dysfunction is thought to play a prominent role in disease pathology, and we sought to characterize secreted signals that may contribute to disease pathology. Transcriptional profiling of senescent type II alveolar epithelial cells from mice with epithelial-specific telomere dysfunction identified the transforming growth factor-ß family member, growth and differentiation factor 15 (Gdf15), as the most significantly upregulated secreted protein. Gdf15 expression is induced in response to telomere dysfunction and bleomycin challenge in mice. Gdf15 mRNA is expressed by lung epithelial cells, and protein can be detected in peripheral blood and bronchoalveolar lavage following bleomycin challenge in mice. In patients with IPF, GDF15 mRNA expression in lung tissue is significantly increased and correlates with pulmonary function. Single-cell RNA sequencing of human lungs identifies epithelial cells as the primary source of GDF15, and circulating concentrations of GDF15 are markedly elevated and correlate with disease severity and survival in multiple independent cohorts. Our findings suggest that GDF15 is an epithelial-derived secreted protein that may be a useful biomarker of epithelial stress and identifies IPF patients with poor outcomes.

[Dissolution behavior of Fuzi Lizhong pill based on simultaneous determination of two components in Glycyrrhizae Radix et Rhizoma].

To preliminarily investigate the dissolution behavior of Fuzi Lizhong pill, provide the basis for its quality control and lay foundation for in vivo dissolution behavior by determining the dissolution rate of liquiritin and glycyrrhizic acid. High-performance liquid chromatography (HPLC) method for simultaneous content determination of the two active ingredients of liquiritin and glycyrrhizic acid in Fuzi Lizhong pill was established; The dissolution amount of these two active ingredients in fifteen batches of Fuzi Lizhong pill from five manufacturers was obtained at different time points, and then the cumulative dissolution rate was calculated and cumulative dissolution curve was drawn. The similarity of cumulative dissolution curve of different batches was evaluated based on the same factory, and the similarity of cumulative dissolution curve of different factories was evaluated based on the same active ingredients. The dissolution model of Fuzi Lizhong pill based on two kinds of active ingredients was established by fitting with the dissolution data. The best dissolution medium was 0.25% sodium lauryl sulfate. The dissolution behavior of liquiritin and glycyrrhizic acid in Fuzi Lizhong pill was basically the same and sustained release in 48 h. Three batches of the factories (factory 2, factory 3, factory 4 and factory 5) appeared to be similar in dissolution behavior, indicating similarity in dissolution behavior in most factories. Two of the three batches from factory 1 appeared to be not similar in dissolution behavior of liquiritin and glycyrrhizic acid. The dissolution data of the effective ingredients from different factories were same in fitting, and Weibull model was the best model in these batches. Fuzi Lizhong pill in 15 batches from 5 factories showed sustained release in 48 h, proving obviously slow releasing characteristics "pill is lenitive and keeps a long-time efficacy". The generally good dissolution behavior also suggested that quality of different batches from most factories was stable. The dissolution behavior of liquiritin and glycyrrhizic acid in different factories was different, suggesting that the source of medicinal materials and preparation technology parameters in five factories were different.

[Analysis on dosage form theory and current application situation of traditional Chinese medicine pill].

Traditional Chinese medicine(TCM) pill, the most representative and successive dosage form, is called as one of the four classical TCM dosage forms. "Pills could keep the lasting and lenitive therapeutic efficacy for a long period" is the most classical dosage form theory, showing a guidance significance in making recipe, preparations and clinic application. In this article, we would elucidate the inheritance and development significance of TCM pills in three key points, including dosage form theory, pharmaceutical preparation technology and clinic usage based on the pharmaceutics connotation of this theory. From this, it can provide the basis for researches on pills mechanism, material basis and mode of action in clinical application.

Improved Image Quality and Decreased Radiation Dose of Lower Extremity Computed Tomography Angiography Using Low-Tube-Voltage and Adaptive Iterative Reconstruction.

OBJECTIVE: The aim of the study was to investigate the feasibility of low-tube-voltage computed tomography (CT) in combination with 3-dimensional adaptive iterative dose reduction (AIDR-3D) algorithm in lower extremity CT angiography. METHODS: The CT data of the 120-kV group (n = 30) were reconstructed with filtered back projection (FBP) algorithm. The CT data of the 100-kV group (n = 30) were reconstructed with FBP as well as AIDR-3D algorithms. RESULTS: The 100-kV group showed significantly lower dose-length product than the 120-kV group (P < 0.05). In comparison with the 120-kV and FBP protocol, the 100-kV and FBP protocol showed significantly increased vascular density and noise (P < 0.05). However, in the 100-kV group, images reconstructed with AIDR-3D showed significantly lower noise and significantly higher signal-to-noise ratio and contrast-to-noise ratio than FBP (P < 0.05). CONCLUSIONS: Low-tube-voltage (100 kV) 320-row CT in combination with AIDR-3D reconstruction can significantly improve the image quality and reduce radiation dose of lower extremity CT angiography.

[Progress in research on obstructive sleep apnea syndrome with hypertension].

Obstructive sleep apnea syndrome (OSAS) is a complicated chronic disease caused by certain reasons, characterized by obstruction of the upper airway and apnea or hypopnea during sleep, which can be followed by anoxia, snoring and daytime sleepiness. Recent studies have shown that hypertension is closely connected to OSAS. OSAS can lead to hypertension by several possible mechanisms. The diagnosis of OSAS mainly depends on the medical history, sign, polysomnogram (PSG) result and the frequency of apnea and hypopnea. OSAS can be relieved by continuous positive airway pressure (CPAP), oral orthodontic treatment, medicine, change of lifestyles and others. This brief review focuses on the mechanism of hypertension due to OSAS and the diagnosis criteria and treatment of OSAS.

Pathways of Media Contact to Health Literacy in Middle-Aged and Older People: The Chain Mediation Effect of Perceived Social Support and Self-Efficacy.

Objective: To understand the status of media exposure, social support, self-efficacy, and health literacy among middle-aged and older adults in China, and explore the impact path of media exposure on the health literacy of this population, providing a reference for promoting their physical and mental health. Methods: From July to November 2022, a multi-stage random sampling method was employed to survey 16,938 Chinese middle-aged and older adults aged 46 and above. Structural equation modeling and statistical analysis were conducted using LISREL 8.8 and Mplus 8.3 software. Results: The average score for media exposure among Chinese middle-aged and older adults was (18.55±5.36), perceived social support was (60.68±12.51), self-efficacy was (28.76±5.40), and health literacy was (35.49±6.05). Statistical results revealed that media exposure has a positive impact on the health literacy of middle-aged and older adults, with a direct effect of 0.091 (p < 0.001). Mediation analysis showed that media exposure can affect the health literacy of this population through the independent mediating effects of perceived social support (ß = 0.013, p < 0.001) and self-efficacy (ß = 0.029, p < 0.001), as well as through a chain mediation effect involving perceived social support and self-efficacy (ß = 0.015, p < 0.001). Conclusion: As a pathway for health information dissemination, media exposure plays a crucial role in the intervention of health literacy among middle-aged and older adults. Perceived social support and self-efficacy not only have independent mediating effects but also significant chain mediating effects in the relationship between media exposure and health literacy among this population. Therefore, improving the health literacy of middle-aged and older people can be popularized through media and improved in a multi-path, all-round, and precise way with the help of related technologies and social forces from which media literacy can be improved.

Impact of Bullying Victimization on Chinese College Students' Suicidal Tendency: The Moderating Effect of Teachers' Emotional Support and Family Support.

Objective: To explore the influence of bully victims on the suicidal tendencies of college students, and the moderating role of teacher emotional support and family support in the relationship between bully victims and college students' suicidal tendencies, in order to provide a reference for the effective intervention of college students' suicide behavior. Methods: Based on a survey of 15,560 college students. Multiple stepwise regression and Interaction analysis explore the impact of the bully victimization on college students' suicidal tendencies and the moderating role of family support and teacher emotional support in the relationship between the bully victim and college students' suicidal tendencies. Results: This study found that the Suicidal Tendencies score of college students was 19.79 points, indicating that some college students have a risk of suicidal tendencies; secondly, verbal bullying (ß = 0.084, P <0.001), physical bullying (ß = 0.222, P <0.001) and social relationship bullying (ß = 0.122, P <0.001) have a positive and significant impact on the suicidal tendencies of college students; in addition, family support and teacher emotional support have a significant regulatory effect on the bully victim and college students Suicidal Tendencies and family support. The regulating effect was significantly higher than that of teacher emotional support. Conclusion: Chinese college students have the risk of suicidal tendencies; peer bullying victimization is an important reason for affecting college students' suicidal tendencies, teacher emotional support is a protective factor for bully victims to affect college students' suicidal tendencies, and family support has a significant moderating effect on the bully victim and college students' suicidal tendencies. Therefore, it is necessary to actively adopt home-school linkage and home-school communication to reduce campus violence and increase the psychological resilience of college students.

Pyroptosis-related signatures predict immune characteristics and prognosis in IPF.

The purpose of this work was to use integrated bioinformatics analysis to screen for pyroptosis-related genes (PRGs) and possible immunological phenotypes linked to the development and course of IPF. Transcriptome sequencing datasets GSE70866, GSE47460 and GSE150910 were obtained from GEO database. From the GSE70866 database, 34 PRGs with differential expression were found in IPF as compared to healthy controls. In addition, a diagnostic model containing 4 genes PRGs (CAMP, MKI67, TCEA3 and USP24) was constructed based on LASSO logistic regression. The diagnostic model showed good predictive ability to differentiate between IPF and healthy, with ROC-AUC ranging from 0.910 to 0.997 in GSE70866 and GSE150910 datasets. Moreover, based on a combined cohort of the Freiburg and the Siena cohorts from GSE70866 dataset, we identified ten PRGs that might predict prognosis for IPF. We constructed a prognostic model that included eight PRGs (CLEC5A, TREM2, MMP1, IRF2, SEZ6L2, ADORA3, NOS2, USP24) by LASSO Cox regression and validated it in the Leuven cohort. The risk model divided IPF patients from the combined cohort into high-risk and low-risk subgroups. There were significant differences between the two subgroups in terms of IPF survival and GAP stage. There is a close correlation between leukocyte migration, plasma membrane junction, and poor prognosis in a high-risk subgroup. Furthermore, a high-risk score was associated with more plasma cells, activated NK cells, monocytes, and activated mast cells. Additionally, we identified HDAC inhibitors in the cMAP database that might be therapeutic for IPF. To summarize, pyroptosis and its underlying immunological features are to blame for the onset and progression of IPF. PRG-based predictive models and drugs may offer new treatment options for IPF.

Succinate promotes pulmonary fibrosis through GPR91 and predicts death in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is believed to be associated with a notable disruption of cellular energy metabolism. By detecting the changes of energy metabolites in the serum of patients with pulmonary fibrosis, we aimed to investigate the diagnostic and prognostic value of energy metabolites in IPF, and further elucidated the mechanism of their involvement in pulmonary fibrosis. Through metabolomics research, it was discovered that the TCA cycle intermediates changed dramatically in IPF patients. In another validation cohort of 55 patients with IPF compared to 19 healthy controls, it was found that succinate, an intermediate product of TCA cycle, has diagnostic and prognostic value in IPF. The cut-off levels of serum succinate were 98.36 µM for distinguishing IPF from healthy controls (sensitivity, 83.64%; specificity, 63.16%; likelihood ratio, 2.27, respectively). Moreover, a high serum succinate level was independently associated with higher rates of disease progression (OR 13.087, 95%CI (2.819-60.761)) and mortality (HR 3.418, 95% CI (1.308-8.927)). In addition, accumulation of succinate and increased expression of the succinate receptor GPR91 were found in both IPF patients and BLM mouse models of pulmonary fibrosis. Reducing succinate accumulation in BLM mice alleviated pulmonary fibrosis and 21d mortality, while exogenous administration of succinate can aggravate pulmonary fibrosis in BLM mice. Furthermore, GPR91 deficiency protected against lung fibrosis caused by BLM. In vitro, succinate promoted the activation of lung fibroblasts by activating ERK pathway through GPR91. In summary, succinate is a promising biomarker for diagnosis and prognosis of IPF. The accumulation of succinate may promote fibroblast activation through GPR91 and pulmonary fibrosis.

Acute endurance exercise induces changes in vasorelaxation responses that are vessel-specific.

The dynamic adjustment and amplitude of the endothelium-dependent vasorelaxation of the carotid, aorta, iliac, and femoral vessels were measured in response to acute low- (LI) or high-intensity (HI) endurance exercise. Vasorelaxation to 10(-4) M ACh was evaluated in 10 control, 10 LI, and 10 HI rats. Two-millimeter sections of carotid, aorta, iliac, and femoral arteries were mounted onto a myography system. Vasorelaxation responses were modeled as a monoexponential function. The overall τ (control, 10.5 ± 6.0 s; LI, 10.4 ± 5.7 s; HI, 11.0 ± 6.9 s) and time-to-steady-state (control, 47.6 ± 24.0 s; LI, 46.2 ± 22.8 s; HI, 49.1 ± 28.3 s) was similar in LI, HI, and control (P > 0.05). The overall (average of four vessel-type) % vasorelaxation was larger in LI (73 ± 16%) and HI (73 ± 16%) than in control (66 ± 19%) (P < 0.05). The overall rate of vasorelaxation was greater in LI (1.9 ± 0.9%·s(-1)) and HI (1.9 ± 1.1%·s(-1)) compared with control (1.6 ± 0.7%·s(-1)) (P < 0.05). The vessel-specific responses (average response for the three conditions) showed that carotid displayed a slower adjustment (τ, 18.9 ± 4.4 s; time-to-steady-state, 80.4 ± 18.4 s) compared with the aorta (τ, 10.3 ± 3.8 s; time-to-steady-state, 46.3 ± 15.2 s), the iliac (τ, 6.3 ± 2.1 s; time-to-steady-state, 30.3 ± 9.0 s), and the femoral (τ, 6.0 ± 1.9 s; time-to-steady-state, 29.3 ± 8.4 s). The % vasorelaxation was larger in the carotid (82 ± 14%) than in the aorta (67 ± 16%), iliac (61 ± 13%), and femoral (71 ± 19%) (P > 0.05). The rate of vasorelaxation was carotid (1.1 ± 0.2%·s(-1)), aorta (1.5 ± 0.4%·s(-1)), iliac (2.2 ± 0.8%·s(-1)), and femoral (2.6 ± 1.0%·s(-1)). In conclusion, an acute bout of endurance exercise increased vascular responsiveness. The dynamic and percent adjustments were vessel-specific with vessel function likely determining the response.