Metabolic Mediators Research Articles

Enhancing Spns2/S1P in macrophages alleviateshyperinflammation and prevents immunosuppression in sepsis.

Sepsis is a leading cause of in-hospital mortality resulting from a dysregulated response to infection. Novel immunomodulatory therapies targeting macrophage metabolism have emerged as an important focus for current sepsis research. However, understanding the mechanisms underlying macrophage metabolic reprogramming and how they impact immune response requires further investigation. Here, we identify macrophage-expressed Spinster homolog 2 (Spns2), a major transporter of sphingosine-1-phosphate (S1P), as a crucial metabolic mediator that regulates inflammation through the lactate-reactive oxygen species (ROS) axis. Spns2 deficiency in macrophages significantly enhances glycolysis, thereby increasing intracellular lactate production. As a key effector, intracellular lactate promotes pro-inflammatory response by increasing ROS generation. The overactivity of the lactate-ROS axis drives lethal hyperinflammation during the early phase of sepsis. Furthermore, diminished Spns2/S1P signaling impairs the ability of macrophages to sustain an antibacterial response, leading to significant innate immunosuppression in the late stage of infection. Notably, reinforcing Spns2/S1P signaling contributes to balancing the immune response during sepsis, preventing both early hyperinflammation and later immunosuppression, making it a promising therapeutic target for sepsis.

DMC (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone) enhances exercise tolerance via the AMPK-SIRT1-PGC-1α pathway in mice fed a high-fat diet.

Obesity is caused by an imbalance between energy intake and energy expenditure. This study aimed to determine the effects and mechanisms of 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) on exercise tolerance in high-fat diet (HFD)-fed mice. Male C57BL/6J mice were randomly divided into two categories (7 groups [n = 8]): sedentary (control [CON], HFD, 200 mg/kg DMC, and 500 mg/kg DMC) and swimming (HFD, 200 mg/kg DMC, and 500 mg/kg DMC). Except the CON group, all other groups were fed HFD with or without DMC intervention for 33 days. The swimming groups were subjected to exhaustive swimming (three sessions/week). Changes in swimming time, glucolipid metabolism, body composition, biochemical indicators, histopathology, inflammation, metabolic mediators, and protein expression were assessed. DMC combined with regular exercise improved endurance performance, body composition, glucose and insulin tolerance, lipid profile, and the inflammatory state in a dose-dependent manner. Further, DMC alone or combined with exercise could restore normal tissue morphology, reduce fatigue-associated markers, and boost whole-body metabolism and the protein expression of phospho-AMP-activated protein kinase alpha/total-AMP-activated protein kinase alpha (AMPK), sirtuin-1 (SIRT1), peroxisome-proliferator-activated receptor gamma coactivator 1alpha (PGC-1α), and peroxisome proliferator-activated receptor alpha in the muscle and adipose tissues of HFD-fed mice. DMC exhibits antifatigue effects by regulating glucolipid catabolism, inflammation, and energy homeostasis. Furthermore, DMC exerts a synergistic exercise-related metabolic effect via the AMPK-SIRT1-PGC-1α signaling pathway, suggesting that DMC is a potential natural sports supplement with mimicked or augmented exercise effects for obesity prevention.

Apoptosis-inducing factor: a mitochondrial protein associated with metabolic diseases-a narrative review.

Apoptosis-inducing factor (AIF), a flavin protein in mitochondria, is originally found to induce apoptosis under the stimulation of pro-apoptotic factors. As a mitochondrial flavin adenine dinucleotide-dependent oxidoreductase, AIF is involved in the regulation of mammalian cell metabolism by regulating respiratory enzyme activity, antioxidant stress, promoting mitochondrial autophagy and glucose uptake, etc. Herein, we focused on the research progress regarding the molecular mechanism of AIF in metabolic mediation and the recent research on AIF in metabolic diseases, as well as the AIF-mediated apoptotic process. Articles for this paper were obtained by reviewing the literature related to the role of AIF in metabolic diseases on PubMed. The search terms included the following: "apoptosis", "metabolism" or "metabolic diseases" plus "apoptosis-inducing factor". The titles, abstracts, and full texts of relevant English-language publications published from October 1996 to June 2022 were manually screened to clarify the role of AIF in metabolic diseases. We found that AIF played an important role in a variety of metabolically-related diseases, such as diabetes, obesity, metabolic syndrome, and tumor metabolism, by mediating apoptosis. We summarized the important role of AIF in a variety of metabolic diseases, which might help to further expand the understanding of AIF and to develop AIF-related therapeutic targets.

A single exercise exertion initiates antioxidant and vascular-protective mechanisms in patients with heart failure

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): DZHK (German Centre for Cardiovascular Research). Background Increased systemic inflammation and metabolic dysfunction at rest are observed in heart failure with reduced ejection fraction (HFrEF). Regular (endurance) exercise training can alleviate both. On the other hand, cardiorespiratory exercise testing (CPET) exerts a physical challenge thereby initiating the acute activation of the immune system and several metabolic pathways. Aim To characterize the differences and similarities acute inflammatory and metabolic activation in response to an acute exercise challenge, and their resolution after 2 hours of rest in patients with HFrEF as compared to controls. Methods Participants with HFrEF (n = 16) as well as age and sex matched controls (CON, n = 13) were investigated at baseline (T1), immediately after CPET (T2), and after 2 hours of resting post-CPET (T3). Clinical and physiological parameters, leukocyte profile, plasma cytokines and metabolites were assessed along with inflammatory and metabolic parameters at all three time points. Results and Discussion Cardiovascular risk profile as well as leukocyte, cytokine and metabolic parameters at T1 was similar in CON and HFrEF. Immediately after CPET, lactate, natural killer (NK) and NK-T cell blood counts, among others, were significantly increased in both groups. In HFrEF specifically, platelet aggregates with NK cells, CD8+ cytotoxic T cells and "classical" CD14++CD16-monocytes as well as phosphatidylcholines and triglycerides were increased. After 2h of rest post-CPET, almost all altered parameters returned to baseline in CON. In HFrEF, blood counts and morphological markers of inflammatory effector cell types, including CD8+ T cells and neutrophils remained elevated. Blood levels of inflammatory cytokines were associated to elevated levels of various phosphatidycholines in HFrEF, but not in CON, potentially pointing towards a link to cell death. Blood levels of methionine sulfoxide-to-methionine, declined at T3 versus T1 in both groups, potentially indicating activation of anti-oxidant methionine sulfoxide reductases. In addition, trigonelline, an inhibitor of trimethylamine N-oxide (TMAO) synthesis from choline was elevated by CPET in both groups and this increase correlated inversely with TMAO-to-choline ratio. This might indicate a so far unexplored exercise-induced vascular-protective mechanism by limiting the pro-atherogenic effects of TMAO. Conclusion CPET induced a complex acute immuno-metabolic response, whose restitution to baseline levels differed between HFrEF and healthy controls. Despite longer persistence of pro-inflammatory and metabolic mediators present in the circulation after the end of an acute exercise session, novel anti-oxidant and vascular protective mechanisms of exercise have been identified and appear to be still active in patients with HFrEF.

Hepatic Cdkal1 deletion regulates HDL catabolism and promotes reverse cholesterol transport

Background and aimsAssociations between CDKAL1 variants and cholesterol efflux capacity (CEC) have been reported. This study aimed to investigate the effects of Cdkal1 deficiency on high-density lipoprotein (HDL) metabolism, atherosclerosis, and related pathways. MethodsLipid and glucose metabolic profiles, CEC, and in vivo reverse cholesterol transport (RCT) were compared in liver-specific Alb-Cre:Cdkal1fl/fl and Cdkal1fl/fl mice. Aortic atherosclerosis was compared in Apoe−/−Alb-Cre:Cdkal1fl/fl and Apoe−/− mice fed high-fat diets. HDL subclasses and mediators of HDL metabolism from Alb-Cre:Cdkal1fl/fl mice were examined. ResultsHDL-cholesterol level tended to be higher in the Alb-Cre:Cdkal1fl/fl mice (p = 0.050). Glucose and other lipid profiles were similar in the two groups of mice, irrespective of diet. The mean CEC was 27% higher (p = 0.007) in the Alb-Cre:Cdkal1fl/fl mice, as were the radioactivities of bile acids (mean difference 17%; p = 0.035) and cholesterol (mean difference 42%; p = 0.036) from faeces. The radioactivity tendency was largely similar in mice fed a high-fat diet. Atherosclerotic lesion area tended to be smaller in the Apoe−/−Alb-Cre:Cdkal1fl/fl mice than in the Apoe−/− mice (p = 0.067). Cholesterol concentrations in large HDLs were higher in the Alb-Cre:Cdkal1fl/fl mice (p = 0.024), whereas in small HDLs, they were lower (p = 0.024). Endothelial lipase (mean difference 39%; p = 0.002) and hepatic lipase expression levels (mean difference 34%; p < 0.001) were reduced in the Alb-Cre:Cdkal1fl/fl mice, whereas SR-B1 expression was elevated (mean difference 35%; p = 0.007). ConclusionsThe promotion of CEC and RCT in Alb-Cre:Cdkal1fl/fl mice verified the effect of CDKAL1 seen in human genetic data. These phenotypes were related to regulation of HDL catabolism. This study suggests that CDKAL1 and associated molecules could be targets for improving RCT and vascular pathology.

Metabolomics investigation reveals metabolic mediators associated with Ligusticum wallichii-relieving experimental acute pancreatitis

Background: Acute pancreatitis (AP) is a typical destructive inflammation of the pancreas. The direct effect of L. wallichii on AP remains unknown. Methods: AP animal model was constructed by intraperitoneal injection of caerulein in male Sprague–Dawley rats. L. wallichii extracts were used to treat rats with AP. Then, tissue injury was evaluated by hematoxylin and eosin staining. Serum indicators, including amylase, lipase, KL-6, creatinine and urea, were measured by commercial kits. GC/MS-based metabolomics was utilized to characterize the metabolome. Results: Intraperitoneal injection of L. wallichii extracts protected against lung, liver, and kidney injury in rats with caerulein-induced AP. GC/MS-based metabolomics analysis revealed that L. wallichii treatment could restore caerulein-induced alteration of the abundance of most metabolites. These differential metabolites enriched twelve metabolic pathways that were able to be reprogramed by L. wallichii administration. L. wallichii impacted arginine metabolism by inhibiting arginase expression and activity. Inhibition of arginase by S-(2-boronoethyl)-L-cysteine (BEC) could relieve caerulein-induced AP, suggesting that suppression of arginase is a potential mechanism for L. wallichii to ameliorate AP. Conclusion: Our data provide the inter-relationship between metabolic reprograming and anti-AP effects of L. wallichii extracts in rats, and highlight the potential of metabolic reprograming against AP pathogenesis.

Role of MOTS-c in the regulation of bone metabolism.

MOTS-c, a mitochondrial-derived peptide (MDP), is an essential regulatory mediator of cell protection and energy metabolism and is involved in the development of specific diseases. Recent studies have revealed that MOTS-c promotes osteoblast proliferation, differentiation, and mineralization. Furthermore, it inhibits osteoclast production and mediates the regulation of bone metabolism and bone remodeling. Exercise effectively upregulates the expression of MOTS-c, but the specific mechanism of MOTS-c regulation in bone by exercise remains unclear. Therefore, this article reviewed the distribution and function of MOTS-c in the tissue, discussed the latest research developments in the regulation of osteoblasts and osteoclasts, and proposed potential molecular mechanisms for the effect of exercise on the regulation of bone metabolism. This review provides a theoretical reference for establishing methods to prevent and treat skeletal metabolic diseases.

Identification of calcium and integrin-binding protein 1 as a reprogrammed glucose metabolism mediator to restrict immune cell infiltration in the stromal compartment of pancreatic ductal adenocarcinoma.

An increasing body of evidence has suggested that reprogrammed metabolism plays a critical role in the progression of pancreatic ductal adenocarcinoma (PDAC) by affecting the tumor and stromal cellular components in the tumor microenvironment (TME). By analyzing the KRAS pathway and metabolic pathways, we found that calcium and integrin-binding protein 1 (CIB1) corresponded with upregulation of glucose metabolism pathways and was associated with poor prognosis in patients with PDAC from The Cancer Genome Atlas (TCGA). Elevated CIB1 expression combined with upregulated glycolysis, oxidative phosphorylation (Oxphos), hypoxia pathway activation, and cell cycle promoted PDAC tumor growth and increased tumor cellular com-ponents. Furthermore, we confirmed the mRNA overexpression of CIB1 and co-expression of CIB1 and KRAS mutation in cell lines from the Expression Atlas. Subsequently, immunohistochemistry staining from the Human Protein Atlas (HPA) showed that high expression of CIB1 in tumor cells was associated with an increased tumor compartment and reduced stromal cellular abundance. Furthermore, using multiplexed immunohistochemistry (mIHC), we verified that low stromal abundance was correlated with low infiltration of CD8+ PD-1- T cells which led to suppressed anti-tumor immunity. Overall, our findings identify CIB1 as a metabolic pathway-mediated factor for the restriction of immune cell infiltration in the stromal compartment of PDAC and highlight the potential value of CIB1 as a prognostic biomarker involved in metabolic reprogramming and immune modulation.

OA05 Harnessing high throughput multiplex immunoassays and protein association networks to identify diagnostic protein biomarkers of rheumatoid arthritis-cardiovascular disease (RA-CVD) multimorbid axis

Abstract Background/Aims People with rheumatoid arthritis (RA) have higher mortality rates compared to the general population, primarily due to excess cardiovascular (CV) disease (CVD). The earliest stages of RA are associated with CV abnormalities but biomarkers to identify CVD in early RA are lacking. We aimed to identify focused protein biomarkers that associate with cardiac magnetic resonance imaging (CMR) abnormalities in a treatment-naïve, new-onset RA trial cohort and the predominant inflammatory and metabolic pathways involved in RA-CVD. Methods CADERA (Coronary Artery Disease in Early RA) was a bolt-on study to a parent RCT in an early RA inception cohort. 81 treatment-naïve early RA patients underwent CMR at baseline as part of CADERA. Proximity extension immunoassay (OIink) was used to measure normalised protein expression across inflammation, cardiovascular II/III and cardiometabolic panels in CADERA patients. Bayesian mixed effects linear regression was used to identify significant proteins associated with CMR parameters of myocardial oedema/fibrosis and vascular stiffness at baseline. Then, an expanded protein-protein interaction (PPI) network using above proteins was created using an induced network approach (String-DB) and k-means clustering applied to identify protein clusters that were subsequently subjected to Gene ontology (GO) and KEGG enrichment analysis. Results Of 340 proteins analysed using Olink, 108 proteins were associated with CMR markers of myocardial fibrosis/oedema (64 proteins) and vascular stiffness (44 proteins) Table 1 highlights the top 5 proteins for each CMR parameter. K-means clustering of the expanded PPI network identified 4 clusters with roles in vascular endothelial growth factor receptor binding and JAK-STAT signalling pathway (cluster 1); IL27 receptor binding and NF-kappa B signalling pathway (cluster 2); Macrophage CSF receptor binding and ErbB signalling pathway (cluster 3); and IL10 receptor activity and complement and coagulation cascades (cluster 4). Conclusion This is the first study to identify protein biomarkers of RA-CVD, an area of unmet clinical need, using a combination of targeted high throughput immunoassays, Bayesian and network analyses. Targeted techniques such as Olink may help identify potential diagnostic biomarkers of RA-CVD. Pathway analysis provides insight into the inter-relationship between inflammation and metabolic mediators of RA-CVD axis. Disclosure R. Shukla: None. N. Black: None. D. Plant: None. C. Miller: None. S. Plein: None. M.H. Buch: None.

New Insights into Pathophysiology and New Risk Factors for ACS.

Cardiovascular disease still represents the main cause of mortality worldwide. Despite huge improvements, atherosclerosis persists as the principal pathological condition, both in stable and acute presentation. Specifically, acute coronary syndromes have received substantial research and clinical attention in recent years, contributing to improve overall patients' outcome. The identification of different evolution patterns of the atherosclerotic plaque and coronary artery disease has suggested the potential need of different treatment approaches, according to the mechanisms and molecular elements involved. In addition to traditional risk factors, the finer portrayal of other metabolic and lipid-related mediators has led to higher and deep knowledge of atherosclerosis, providing potential new targets for clinical management of the patients. Finally, the impressive advances in genetics and non-coding RNAs have opened a wide field of research both on pathophysiology and the therapeutic side that are extensively under investigation.

Single-nuclei RNA Profiling Reveals Disruption of Adipokine and Inflammatory Signaling in Adipose Tissue of Burn Patients.

We conducted a large-scale investigation of the systemic and adipose tissue-specific alterations in a clinical population of burn patients to identify factors that may influence hypermetabolism. Previous research has identified chronic disturbances in adipose tissue inflammation, lipolysis, and browning, which may drive the perpetuation of hypermetabolism following the severe adrenergic stress of a burn injury. Given that adipose tissue is thought to be a central node in the regulation of systemic metabolism, we believe that systematically delineating the pathologic role of adipose tissue postburn, will lead to the identification of novel interventions to mitigate morbidity and mortality from severe burns. This was a single-institution cohort study, which obtained plasma and subcutaneous adipose tissue samples from severely burn adult patients over various time points during acute hospitalization. Whole-body clinical, metabolic, and inflammatory mediators were assessed in plasma, while genetic analyses through RT-qPCR and single-nuclei RNA sequencing were conducted in adipose tissue. Systemic inflammation and adrenergic stress increase IL-6 signaling, lipolysis, browning, and adipokine dysfunction in the adipose tissue of adult burn patients, which may further propagate the long-term hypermetabolic response. Moreover, using single-nuclei RNA sequencing, we provide the first comprehensive characterization of alterations in the adipose tissue microenvironment occurring at acute and chronic stages postburn. We provide novel insight toward the effect of burns on adipokine release, inflammatory signaling pathways, and adipose heterogeneity over the trajectory of acute and chronic stages.

The Role of Cellular Metabolism in Maintaining the Function of the Dentine-Pulp Complex: A Narrative Review.

The cellular metabolic processes ensure the physiological integrity of the dentine-pulp complex. Odontoblasts and odontoblast-like cells are responsible for the defence mechanisms in the form of tertiary dentine formation. In turn, the main defence reaction of the pulp is the development of inflammation, during which the metabolic and signalling pathways of the cells are significantly altered. The selected dental procedures, such as orthodontic treatment, resin infiltration, resin restorations or dental bleaching, can impact the cellular metabolism in the dental pulp. Among systemic metabolic diseases, diabetes mellitus causes the most consequences for the cellular metabolism of the dentine-pulp complex. Similarly, ageing processes present a proven effect on the metabolic functioning of the odontoblasts and the pulp cells. In the literature, several potential metabolic mediators demonstrating anti-inflammatory properties on inflamed dental pulp are mentioned. Moreover, the pulp stem cells exhibit the regenerative potential essential for maintaining the function of the dentine-pulp complex.

Abstract 1093: Measuring and inhibiting purine metabolism in patients with glioblastoma

Abstract Introduction: We have previously found that purine metabolism is an important metabolic mediator of treatment resistance in glioblastoma (GBM). Mycophenolate mofetil (MMF), an inhibitor of purine synthesis, synergizes with radiation and temozolomide in mouse models of GBM. No measurements of purine synthesis have been performed in human cancer patients, nor has the purine inhibitor MMF been used clinically for patients with GBM. Methods: We infused clinical-grade 13C6 glucose into patients undergoing craniotomy for presumed GBM and used mass spectrometry to measure carbon incorporation into purines in cortex and disparate tumor regions. We are conducting a phase 0/1 trial (NCT04477200) to determine the safety and potential efficacy of the purine inhibitor MMF in patients with GBM. In the phase 0 arm, patients with recurrent GBM needing tumor re-resection receive MMF for one week prior to surgery and tumor and brain tissue is analyzed by mass spectrometry to determine drug concentrations and target engagement. In the phase 1 portions, patients (age &amp;gt;18, KPS ≥ 60) with recurrent GBM are treated with MMF and a second course of radiation while patients with newly diagnosed GBM are treated with radiation (RT), temozolomide (TMZ) and MMF followed by cyclic MMF and TMZ. A TITE-CRM algorithm is employed to dose-escalate MMF (range 500-2000 mg BID) and determine its maximum tolerated dose in combination with RT and/or TMZ. Results: Stable isotope tracing has been performed on 8 patients with suspected GBM. Purine synthesis was increased in tumor tissue compared to normal cortex in all patients, with most patients having 10-30-fold increased purine labeling in tumor. We have enrolled 8 patients on our phase 0 peri-surgical study and all had active concentrations of mycophenolic acid (the active metabolite of MMF) in enhancing and non-enhancing GBM tissue. We have enrolled 28 evaluable phase 1 patients (13 recurrent, 15 new). No dose-limiting toxicities have been observed with MMF (1000-2000 mg BID) in combination with re-irradiation or cyclic TMZ. In concurrent chemoradiation with MMF, we have observed two dose limiting grade 3 toxicities at 2000 mg, both improved with treatment break. Other main toxicities are mild nausea and fatigue. Interim median overall survival in recurrent phase 1 patients is 15.6 months, which compares favorably with typical survival time of 8-10 months in this population. In the newly diagnosed cohort, median survival is not yet reached, but 14 of 15 patients are alive and without progressive tumor. Conclusions: Glucose-derived purine synthesis is elevated in human GBM compared to cortex, which could provide a favorable therapeutic index for purine synthesis inhibition. The purine synthesis inhibitor MMF achieves active concentrations in human GBM, is reasonably well tolerated in combination with standard GBM treatments, and is associated with promising preliminary clinical outcomes. Citation Format: Yoshie Umemura, Andrew J. Scott, Wajd Al-Holou, Anjali Mittal, Weihua Zhou, Kari Wilder-Romans, Jie Xu, Nathan Qi, Maureen Kachman, Michelle Kim, Larry Junck, Denise Leung, Nathan Clarke, Jason Heth, Bo Wen, Amit Pai, Vijay Tarnal, Deepak Nagrath, Theodore Lawrence, Costas A. Lyssiotis, Daniel R. Wahl. Measuring and inhibiting purine metabolism in patients with glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1093.

Response to acute hyperglycemia and high fructose in cultured tenocytes.

High monosaccharide levels are intimately associated with diabetes and impact tendon cells through inflammation and impairment in metabolic homeostasis. Experiments were designed to understand the responses elicited by cultured tenocytes under monosaccharide stress induced by hyperglycemia and hyperfructosemia. We simulated hyperglycemia and hyperfructosemia in vitro by treating tenocytes with media containing sublethal concentrations of glucose and fructose, respectively. Exposure of tenocytes to high glucose and high fructose altered the levels of IL-1β, IL-2, IL-6, IL10 and IL-17A. AMPK expression was increased in high-glucose and decreased in high-fructose groups. High fructose increased the level of IRS-1 compared with the control. Increased mitochondrial superoxide levels and compromised mitochondrial membrane integrity were exhibited by both the groups. The findings from the network analysis revealed many altered genes that are related to pathways for enzyme-linked receptor protein signaling, positive regulation of metabolic processes, transmembrane receptor tyrosine kinase pathway, insulin receptor signaling and regulation of cytokine production. Overall, the data suggest that the tenocytes under high monosaccharide levels exhibit survival responses by altering the expression status of cytokines and metabolic mediators that are involved in the underlying pathogenesis of tendinopathy.

The Role of Genetic, Metabolic, Inflammatory, and Immunologic Mediators in the Progression of Intraductal Papillary Mucinous Neoplasms to Pancreatic Adenocarcinoma.

Intraductal papillary mucinous neoplasms (IPMN) have the potential to progress to pancreatic ductal adenocarcinoma (PDAC). As with any progression to malignancy, there are a variety of genetic and metabolic changes, as well as other disruptions to the cellular microenvironment including immune alterations and inflammation, that can contribute to tumorigenesis. Previous studies further characterized these alterations, revealing changes in lipid and glucose metabolism, and signaling pathways that mediate the progression of IPMN to PDAC. With the increased diagnosis of IPMNs and pancreatic cysts on imaging, the opportunity to attenuate risk with the removal of high-risk lesions is possible with the understanding of what factors accelerate malignant progression and how they can be clinically utilized to determine the level of dysplasia and stratify the risk of progression. Here, we reviewed the genetic, metabolic, inflammatory, and immunologic pathways regulating the progression of IPMN to PDAC.

Preserved Ratio Impaired Spirometry, Metabolomics, and the Risk of Type 2 Diabetes.

Whether baseline preserved ratio impaired spirometry (PRISm) is associated with the risk of developing type 2 diabetes (T2D) and if this association could be mediated by circulating metabolites remains to be elucidated. To measure the prospective association of PRISm with T2D and potential metabolic mediators thereof. This study used data from the UK Biobank and included 72 683 individuals without diabetes at baseline. PRISm was defined as the predicted forced expiratory volume in 1 second (FEV1) <80% and the FEV1/forced vital capacity ratio ≥0.70. Cox proportional hazards modeling was performed to assess the longitudinal relation between baseline PRISm and incident T2D. Mediation analysis was used to explore the mediation effects of circulating metabolites in the path from PRISm to T2D. During a median follow-up of 12.06 years, 2513 participants developed T2D. Individuals who had PRISm (N = 8394) were 47% (95% CI, 33%-63%) more likely to develop T2D compared with those who had normal spirometry (N = 64 289). A total of 121 metabolites showed statistically significant mediation effects in the path from PRISm to T2D (false discovery rate <0.05). Glycoprotein acetyls, cholesteryl esters in large high-density lipoprotein (HDL), degree of unsaturation, cholesterol in large HDL, and cholesteryl esters in very large HDL were the top 5 metabolic markers, with mediation proportions (95% CI) being 11.91% (8.76%-16.58%), 11.04% (7.34%-15.55%), 10.36% (7.34%-14.71%), 9.87% (6.78%-14.09%), and 9.51% (6.33%-14.05%), respectively. A total of 11 principal components that explained 95% variance of the metabolic signatures accounted for 25.47% (20.83%-32.19%) of the relation between PRISm and T2D. Our study revealed the association of PRISm with T2D risk and the potential roles of circulating metabolites in mediating this association.

Biomarkers for Lipid and Albumin Metabolism in Hospitalized Patients with Underlying Diseases and Community-Acquired Pneumonia Caused by Bacterial or SARS-CoV-2 Infection.

To look at the differences and similarities in albumin and lipid metabolism in non-severe COVID-19 infection, non-severe community-acquired pneumonia, and severe community pneumonia with underlying diseases, as well as the relationship between albumin and lipid metabolism and inflammatory mediators. This retrospective analysis comprised 253 individuals with bacterial pneumonia and COVID-19 infection (1 May 2021-1 May 2022). Routine blood examination, blood lipid levels, albumin level, C-reactive protein (CRP) levels, coagulation function, cardiac enzymes, liver function, renal function, immunological function, and bacterial culture were also collected. Correlation analysis was performed using Spearman's test for lipid parameter and Inflammatory factors in the blood. Furthermore, the multiple linear regression (MLR) analysis was employed to analyze the multicollinearity in lipidomics data. The statistical analysis was performed using SPSS statistic version 19.0. There were 63 (24.90%) non-severe community-acquired pneumonia patients (NSCAP), 48 (18.97%) severe community-acquired pneumonia patients (SCAP), 112 (44.27%) non-severe COVID-19 infection patients (NSCOV), and 30 (11.86%) healthy volunteers (HV). In all, 45.59% (116/253) of the patients had underlying diseases. Patients with community-acquired pneumonia had lower albumin and cholesterol levels than those with non-severe COVID-19 infection and healthy controls (t = -3.81, -2.09, P = 0.00, 0.04). Albumin, triglyceride, cholesterol, and LDL-C levels in peripheral blood were considerably lower in the SCAP group than in the NSCAP group. Albumin, cholesterol, HDL-C, LDL-C, and aop-A were all inversely connected with CRP in the SCAP with underlying illness group, but cholesterol level was favorably correlated with lymphocyte count (R = 0.36, P = 0.01). Hypoproteinemia, hypotriglyceridemia, and an elevated neutrophil-to-lymphocyte count ratio are all risk factors for severe community-acquired pneumonia. Hypoalbuminemia and abnormal lipid metabolism are important indicators of bacterial infection, especially severe bacterial pneumonia.

Cyclic AMP is a critical mediator of intrinsic drug resistance and fatty acid metabolism in M. tuberculosis.

Cyclic AMP (cAMP) is a ubiquitous second messenger that transduces signals from cellular receptors to downstream effectors. Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis, devotes a considerable amount of coding capacity to produce, sense, and degrade cAMP. Despite this fact, our understanding of how cAMP regulates Mtb physiology remains limited. Here, we took a genetic approach to investigate the function of the sole essential adenylate cyclase in Mtb H37Rv, Rv3645. We found that a lack of rv3645 resulted in increased sensitivity to numerous antibiotics by a mechanism independent of substantial increases in envelope permeability. We made the unexpected observation that rv3645 is conditionally essential for Mtb growth only in the presence of long-chain fatty acids, a host-relevant carbon source. A suppressor screen further identified mutations in the atypical cAMP phosphodiesterase rv1339 that suppress both fatty acid and drug sensitivity phenotypes in strains lacking rv3645. Using mass spectrometry, we found that Rv3645 is the dominant source of cAMP under standard laboratory growth conditions, that cAMP production is the essential function of Rv3645 in the presence of long-chain fatty acids, and that reduced cAMP levels result in increased long-chain fatty acid uptake and metabolism and increased antibiotic susceptibility. Our work defines rv3645 and cAMP as central mediators of intrinsic multidrug resistance and fatty acid metabolism in Mtb and highlights the potential utility of small molecule modulators of cAMP signaling.

Salivary irisin level is higher and related with interleukin-6 in generalized periodontitis.

Irisin plays an important role in energy homeostasis, inflammation, glucose, and lipid metabolism, and it is shown to have relations with many inflammatory diseases. The aim of the study was to determine saliva and serum irisin and IL-6 levels in patients with stage III/grade B periodontitis compared with individuals with healthy periodontium. Twenty patients with stage III grade B periodontitis (P) and 20 periodontally healthy subjects (control; C) were included in this study. Clinical periodontal measurements were recorded. Saliva and serum levels of irisin and interleukin-6 (IL-6) were analyzed by enzyme-linked immunosorbent assay. Salivary irisin and IL-6 levels were significantly higher in the periodontitis group (p < 0.001, p = 0.002, respectively). Furthermore, serum IL-6 levels were found significantly higher in the periodontitis group compared with controls (p = 0.011). There was no significant difference between the periodontitis and control for serum irisin levels (p > 0.05). Significant positive correlations were found between all periodontal parameters and salivary irisin and IL-6 (p < 0.05) and also between BMI and saliva and serum IL-6 (respectively; r = 0.530, r = 0.329, p < 0.05). There was a positive correlation between salivary irisin and IL-6 (r = 0.369, p < 0.05). Monitoring of salivary irisin and IL-6 might be potential biomarker for predicting the susceptibility to periodontitis. Scientific rationale for the study: Irisin is a novel adipomyokine that has played an important role in energy homeostasis, glucose and lipid metabolism, angiogenesis, immunity, and inflammation. Irisin is involved in the pathogenesis of diseases affecting many body systems. IL-6, another adipomyokine, is a major inflammatory mediator and homeostatic regulator of glucose and lipid metabolism and is associated with periodontitis. No studies investigated the relationship between advanced periodontal disease, irisin, and IL-6 together. The salivary irisin and IL-6 levels were significantly higher and positively correlated in patients with periodontitis relative to healthy controls. Furthermore, serum IL-6 levels were significantly increased in patients with periodontitis. The study shows that irisin and IL-6 can be candidate salivary biomarkers for periodontitis and predict to periodontal status.

Fibroblast growth factor 19 secretion and function in perinatal development.

Limited work has focused on fibroblast growth factor-19 (FGF19) secretion and function in the perinatal period. FGF19 is a potent growth factor that coordinates development of the brain, eye, inner ear, and skeletal system in the embryo, but after birth, FGF19 transitions to be an endocrine regulator of the classic pathway of hepatic bile acid synthesis. FGF19 has emerged as a mediator of metabolism and bile acid synthesis in aged animals and adults in the context of liver disease and metabolic dysfunction. FGF19 has also been shown to have systemic insulin-sensitizing and skeletal muscle hypertrophic effects when induced or supplemented at supraphysiological levels in adult rodent models. These effects could be beneficial to improve growth and nutritional outcomes in preterm infants, which are metabolically resistant to the anabolic effects of enteral nutrition. Existing clinical data on FGF19 secretion and function in the perinatal period in term and preterm infants has been equivocal. Studies in pigs show that FGF19 expression and secretion are upregulated with gestational age and point to molecular and endocrine factors that may be involved. Work focused on FGF19 in pediatric diseases suggests that augmentation of FGF19 secretion by activation of gut FXR signaling is associated with benefits in diseases such as short bowel syndrome, parenteral nutrition-associated liver disease, and biliary atresia. Future work should focus on characterization of FGF19 secretion and the mechanism underpinning the transition of FGF19 function as an embryological growth factor to metabolic and bile acid regulator.