Tissue factor binds to and inhibits interferon-α receptor 1 signaling.

Tissue factor (TF), which is a member of the cytokine receptor family, promotes coagulation and coagulation-dependent inflammation. TF also exerts protective effects through unknown mechanisms. Here, we showed that TF bound to interferon-α receptor 1 (IFNAR1) and antagonized its signaling, preventing spontaneous sterile inflammation and maintaining immune homeostasis. Structural modeling and direct binding studies revealed binding of the TF C-terminal fibronectin III domain to IFNAR1, which restricted the expression of interferon-stimulated genes (ISGs). Podocyte-specific loss of TF in mice (PodΔF3) resulted in sterile renal inflammation, characterized by JAK/STAT signaling, proinflammatory cytokine expression, disrupted immune homeostasis, and glomerulopathy. Inhibiting IFNAR1 signaling or loss of Ifnar1 expression in podocytes attenuated these effects in PodΔF3 mice. As a heteromer, TF and IFNAR1 were both inactive, while dissociation of the TF-IFNAR1 heteromer promoted TF activity and IFNAR1 signaling. These data suggest that the TF-IFNAR1 heteromer is a molecular switch that controls thrombo-inflammation.

Modulation of Myelopoiesis Progenitors Is an Integral Component of Trained Immunity.

Trained innate immunity fosters a sustained favorable response of myeloid cells to a secondary challenge, despite their short lifespan in circulation. We thus hypothesized that trained immunity acts via modulation of hematopoietic stem and progenitor cells (HSPCs). Administration of ß-glucan (prototypical trained-immunity-inducing agonist) to mice induced expansion of progenitors of the myeloid lineage, which was associated with elevated signaling by innate immune mediators, such as IL-1ß and granulocyte-macrophage colony-stimulating factor (GM-CSF), and with adaptations in glucose metabolism and cholesterol biosynthesis. The trained-immunity-related increase in myelopoiesis resulted in a beneficial response to secondary LPS challenge and protection from chemotherapy-induced myelosuppression in mice. Therefore, modulation of myeloid progenitors in the bone marrow is an integral component of trained immunity, which to date, was considered to involve functional changes of mature myeloid cells in the periphery.

Splicing factor YBX1 mediates persistence of JAK2-mutated neoplasms.

Janus kinases (JAKs) mediate responses to cytokines, hormones and growth factors in haematopoietic cells1,2. The JAK gene JAK2 is frequently mutated in the ageing haematopoietic system3,4 and in haematopoietic cancers5. JAK2 mutations constitutively activate downstream signalling and are drivers of myeloproliferative neoplasm (MPN). In clinical use, JAK inhibitors have mixed effects on the overall disease burden of JAK2-mutated clones6,7, prompting us to investigate the mechanism underlying disease persistence. Here, by in-depth phosphoproteome profiling, we identify proteins involved in mRNA processing as targets of mutant JAK2. We found that inactivation of YBX1, a post-translationally modified target of JAK2, sensitizes cells that persist despite treatment with JAK inhibitors to apoptosis and results in RNA mis-splicing, enrichment for retained introns and disruption of the transcriptional control of extracellular signal-regulated kinase (ERK) signalling. In combination with pharmacological JAK inhibition, YBX1 inactivation induces apoptosis in JAK2-dependent mouse and primary human cells, causing regression of the malignant clones in vivo, and inducing molecular remission. This identifies and validates a cell-intrinsic mechanism whereby differential protein phosphorylation causes splicing-dependent alterations of JAK2-ERK signalling and the maintenance of JAK2V617F malignant clones. Therapeutic targeting of YBX1-dependent ERK signalling in combination with JAK2 inhibition could thus eradicate cells harbouring mutations in JAK2.

Targeting biased signaling by PAR1: function and molecular mechanism of parmodulins.

The G protein-coupled receptor (GPCR) protease-activated receptor 1 (PAR1) is a therapeutic target that was originally pursued with the aim of restricting platelet activation and the burden of cardiovascular diseases. In clinical studies, the use of orthosteric PAR1 inhibitors was associated with an increased risk of hemorrhage, including intracranial hemorrhage. Because (1) PAR1 is expressed by various cell types, including endothelial cells, (2) conveys in mice a physiological indispensable function for vascular development during embryogenesis, and (3) is subject to biased signaling dependent on the activating proteases, orthosteric PAR1 inhibition may be associated with unwanted side effects. Alternatively, the protease-activated protein C (aPC) and its variants can promote valuable anti-inflammatory signaling via PAR1. Most recently, small molecule allosteric modulators of PAR1 signaling, called parmodulins, have been developed. Parmodulins inhibit coagulation and platelet activation yet maintain cytoprotective effects typically provoked by PAR1 signaling upon the activation by aPC. In this study, we review the discovery of parmodulins and their preclinical data, summarize the current knowledge about their mode of action, and compare the structural interaction of parmodulin and PAR1 with that of other intracellularly binding allosteric GPCR modulators. Thus, we highlight the pharmaceutical potential and challenges associated with the future development of parmodulins.

DNA-binding protein-A promotes kidney ischemia/reperfusion injury and participates in mitochondrial function.

DNA-binding protein-A (DbpA; gene: Ybx3) belongs to the cold shock protein family with known functions in cell cycling, transcription, translation, and tight junction communication. In chronic nephritis, DbpA is upregulated. However, its activities in acute injury models, such as kidney ischemia/reperfusion injury (IRI), are unclear. To study this, mice harboring Ybx3+/+, Ybx3+/- or the Ybx3-/- genotype were characterized over 24 months and following experimental kidney IRI. Mitochondrial function, number and integrity were analyzed by mitochondrial stress tests, MitoTracker staining and electron microscopy. Western Blot, immunohistochemistry and flow cytometry were performed to quantify tubular cell damage and immune cell infiltration. DbpA was found to be dispensable for kidney development and tissue homeostasis under healthy conditions. Furthermore, endogenous DbpA protein localizes within mitochondria in primary tubular epithelial cells. Genetic deletion of Ybx3 elevates the mitochondrial membrane potential, lipid uptake and metabolism, oxygen consumption rates and glycolytic activities of tubular epithelial cells. Ybx3-/- mice demonstrated protection from IRI with less immune cell infiltration, endoplasmic reticulum stress and tubular cell damage. A presumed protective mechanism was identified via upregulated antioxidant activities and reduced ferroptosis, when Ybx3 was deleted. Thus, our studies reveal DbpA acts as a mitochondrial protein with profound adverse effects on cell metabolism and highlights a protective effect against IRI when Ybx3 is genetically deleted. Hence, preemptive DbpA targeting in situations with expected IRI, such as kidney transplantation or cardiac surgery, may preserve post-procedure kidney function.

Glomerular-tubular crosstalk via cold shock Y-box binding protein-1 in the kidney.

Glomerular-tubular crosstalk within the kidney has been proposed, but the paracrine signals enabling this remain largely unknown. The cold-shock protein Y-box binding protein 1 (YBX1) is known to regulate inflammation and kidney diseases but its role in podocytes remains undetermined. Therefore, we analyzed mice with podocyte specific Ybx1 deletion (Ybx1ΔPod). Albuminuria was increased in unchallenged Ybx1ΔPod mice, which surprisingly was associated with reduced glomerular, but enhanced tubular damage. Tubular toll-like receptor 4 (TLR4) expression, node-like receptor protein 3 (NLRP3) inflammasome activation and kidney inflammatory cell infiltrates were all increased in Ybx1ΔPod mice. In vitro, extracellular YBX1 inhibited NLRP3 inflammasome activation in tubular cells. Co-immunoprecipitation, immunohistochemical analyses, microscale cell-free thermophoresis assays, and blunting of the YBX1-mediated TLR4-inhibition by a unique YBX1-derived decapeptide suggests a direct interaction of YBX1 and TLR4. Since YBX1 can be secreted upon post-translational acetylation, we hypothesized that YBX1 secreted from podocytes can inhibit TLR4 signaling in tubular cells. Indeed, mice expressing a non-secreted YBX1 variant specifically in podocytes (Ybx1PodK2A mice) phenocopied Ybx1ΔPod mice, demonstrating a tubular-protective effect of YBX1 secreted from podocytes. Lipopolysaccharide-induced tubular injury was aggravated in Ybx1ΔPod and Ybx1PodK2A mice, indicating a pathophysiological relevance of this glomerular-tubular crosstalk. Thus, our data show that YBX1 is physiologically secreted from podocytes, thereby negatively modulating sterile inflammation in the tubular compartment, apparently by binding to and inhibiting tubular TLR4 signaling. Hence, we have uncovered an YBX1-dependent molecular mechanism of glomerular-tubular crosstalk.

Applying Machine Learning to Blood Count Data Predicts Sepsis with ICU Admission.

BACKGROUND: Timely diagnosis is crucial for sepsis treatment. Current machine learning (ML) models suffer from high complexity and limited applicability. We therefore created an ML model using only complete blood count (CBC) diagnostics. METHODS: We collected non-intensive care unit (non-ICU) data from a German tertiary care centre (January 2014 to December 2021). Using patient age, sex, and CBC parameters (haemoglobin, platelets, mean corpuscular volume, white and red blood cells), we trained a boosted random forest, which predicts sepsis with ICU admission. Two external validations were conducted using data from another German tertiary care centre and the Medical Information Mart for Intensive Care IV database (MIMIC-IV). Using the subset of laboratory orders also including procalcitonin (PCT), an analogous model was trained with PCT as an additional feature. RESULTS: After exclusion, 1 381 358 laboratory requests (2016 from sepsis cases) were available. The CBC model shows an area under the receiver operating characteristic (AUROC) of 0.872 (95% CI, 0.857-0.887). External validations show AUROCs of 0.805 (95% CI, 0.787-0.824) for University Medicine Greifswald and 0.845 (95% CI, 0.837-0.852) for MIMIC-IV. The model including PCT revealed a significantly higher AUROC (0.857; 95% CI, 0.836-0.877) than PCT alone (0.790; 95% CI, 0.759-0.821; P < 0.001). CONCLUSIONS: Our results demonstrate that routine CBC results could significantly improve diagnosis of sepsis when combined with ML. The CBC model can facilitate early sepsis prediction in non-ICU patients with high robustness in external validations. Its implementation in clinical decision support systems has strong potential to provide an essential time advantage and increase patient safety.

Lipoprotein(a) serum concentrations in children in relation to body mass index, age and sex.

BACKGROUND: Lipoprotein(a) (Lp(a)) is an inherited risk factor for atherosclerotic cardiovascular disease (ASCVD). Limited data exist on Lp(a) values in children. We aimed to evaluate whether Lp(a) concentrations in youth are influenced by BMI. METHODS: 756 blood samples of 248 children with obesity and 264 matched healthy children aged 5 and 18 years, enrolled in the population-based LIFE Child (German civilization diseases cohort) study, were analyzed. Repeat measurements were available in 154 children (1-4 follow ups, ~1 year apart). RESULTS: The median Lp(a) concentration in the total cohort (n = 512) at first visit was 9.7 mg/dL (IQR 4.0-28.3). Lp(a) concentrations between 30-50 mg/dL were observed in 11.5%, while 12.5% exhibited Lp(a) ≧50 mg/dL. There was no association of Lp(a) with body mass index (BMI) (ß = 0.004, P = 0.49). Lp(a) levels did not correlate with age or sex, while Lp(a) was associated positively with low-density lipoprotein cholesterol (ß = 0.05, P < 0.0001). The Lp(a) risk category remained stable in 94% of all children in repeated measurements. CONCLUSIONS: The data showed no association of Lp(a) levels in children with BMI, age or sex. Measurement of Lp(a) in youth may be useful to identify children at increased lifetime risk for ASCVD. IMPACT: In youth, Lp(a) levels are not affected by age, sex and BMI. Lp(a) risk categories remain stable over time in repeated measurements in children. Measurement of Lp(a) in children may be useful as an additional factor to identify children at increased lifetime risk for ASCVD and for reverse family screening.

Excessive sodium chloride ingestion promotes inflammation and kidney fibrosis in aging mice.

In aging kidneys, a decline of function resulting from extracellular matrix (ECM) deposition and organ fibrosis is regarded as "physiological." Whether a direct link between high salt intake and fibrosis in aging kidney exists autonomously from arterial hypertension is unclear. This study explores kidney intrinsic changes (inflammation, ECM derangement) induced by a high-salt diet (HSD) in a murine model lacking arterial hypertension. The contribution of cold shock Y-box binding protein (YB-1) as a key orchestrator of organ fibrosis to the observed differences is determined by comparison with a knockout strain (Ybx1ΔRosaERT+TX). Comparisons of tissue from mice fed with normal-salt diet (NSD, standard chow) or high-salt diet (HSD, 4% NaCl in chow; 1% NaCl in water) for up to 16 mo revealed that with HSD tubular cell numbers decrease and tubulointerstitial scarring [periodic acid-Schiff (PAS), Masson's trichrome, Sirius red staining] prevails. In Ybx1ΔRosaERT+TX animals tubular cell damage, a loss of cell contacts with profound tubulointerstitial alterations, and tubular cell senescence was seen. A distinct tubulointerstitial distribution of fibrinogen, collagen type VI, and tenascin-C was detected under HSD, transcriptome analyses determined patterns of matrisome regulation. Temporal increase of immune cell infiltration was seen under HSD of wild type, but not Ybx1ΔRosaERT+TX animals. In vitro Ybx1ΔRosaERT+TX bone marrow-derived macrophages exhibited a defect in polarization (IL-4/IL-13) and abrogated response to sodium chloride. Taken together, HSD promotes progressive kidney fibrosis with premature cell aging, ECM deposition, and immune cell recruitment that is exacerbated in Ybx1ΔRosaERT+TX animals.NEW & NOTEWORTHY Short-term experimental studies link excessive sodium ingestion with extracellular matrix accumulation and inflammatory cell recruitment, yet long-term data are scarce. Our findings with a high-salt diet over 16 mo in aging mice pinpoints to a decisive tipping point after 12 mo with tubular stress response, skewed matrisome transcriptome, and immune cell infiltration. Cell senescence was aggravated in knockout animals for cold shock Y-box binding protein (YB-1), suggesting a novel protective protein function.

CD248 induces a maladaptive unfolded protein response in diabetic kidney disease.

Dysfunction of mesangial cells plays a major role in the pathogenesis of diabetic kidney disease (DKD), the leading cause of kidney failure. However, the underlying molecular mechanisms are incompletely understood. By unbiased gene expression analysis of glucose-exposed mesangial cells, we identified the transmembrane receptor CD248 as the most upregulated gene, and the maladaptive unfolded protein response (UPR) as one of the most stimulated pathways. Upregulation of CD248 was further confirmed in glucose-stressed mesangial cells in vitro, in kidney glomeruli isolated from diabetic mice (streptozotocin; STZ and db/db models, representing type 1 and type 2 diabetes mellitus, respectively) in vivo, and in glomerular kidney sections from patients with DKD. Time course analysis revealed that glomerular CD248 induction precedes the onset of albuminuria, mesangial matrix expansion and maladaptive UPR activation (hallmarked by transcription factor C/EBP homologous protein (CHOP) induction) but is paralleled by loss of the adaptive UPR regulator spliced X box binding protein (XBP1). Mechanistically, CD248 promoted maladaptive UPR signaling via inhibition of the inositol requiring enzyme 1α (IRE1α)-mediated transcription factor XBP1 splicing in vivo and in vitro. CD248 induced a multiprotein complex comprising heat shock protein 90, BH3 interacting domain death agonist (BID) and IRE1α, in which BID impedes IRE1α-mediated XBP1 splicing and induced CHOP mediated maladaptive UPR signaling. While CD248 knockout ameliorated DKD-associated glomerular dysfunction and reverses maladaptive unfolded protein response signaling, concomitant XBP1 deficiency abolished the protective effect in diabetic CD248 knockout mice, supporting a functional interaction of CD248 and XBP1 in vivo. Hence, CD248 is a novel mesangial cell receptor inducing maladaptive UPR signaling in DKD.

The effect of polyphenols on DNA methylation-assessed biological age attenuation: the DIRECT PLUS randomized controlled trial.

BACKGROUND: Epigenetic age is an estimator of biological age based on DNA methylation; its discrepancy from chronologic age warrants further investigation. We recently reported that greater polyphenol intake benefitted ectopic fats, brain function, and gut microbiota profile, corresponding with elevated urine polyphenols. The effect of polyphenol-rich dietary interventions on biological aging is yet to be determined. METHODS: We calculated different biological aging epigenetic clocks of different generations (Horvath2013, Hannum2013, Li2018, Horvath skin and blood2018, PhenoAge2018, PCGrimAge2022), their corresponding age and intrinsic age accelerations, and DunedinPACE, all based on DNA methylation (Illumina EPIC array; pre-specified secondary outcome) for 256 participants with abdominal obesity or dyslipidemia, before and after the 18-month DIRECT PLUS randomized controlled trial. Three interventions were assigned: healthy dietary guidelines, a Mediterranean (MED) diet, and a polyphenol-rich, low-red/processed meat Green-MED diet. Both MED groups consumed 28 g walnuts/day (+ 440 mg/day polyphenols). The Green-MED group consumed green tea (3-4 cups/day) and Mankai (Wolffia globosa strain) 500-ml green shake (+ 800 mg/day polyphenols). Adherence to the Green-MED diet was assessed by questionnaire and urine polyphenols metabolomics (high-performance liquid chromatography quadrupole time of flight). RESULTS: Baseline chronological age (51.3 ± 10.6 years) was significantly correlated with all methylation age (mAge) clocks with correlations ranging from 0.83 to 0.95; p < 2.2e - 16 for all. While all interventions did not differ in terms of changes between mAge clocks, greater Green-Med diet adherence was associated with a lower 18-month relative change (i.e., greater mAge attenuation) in Li and Hannum mAge (beta = - 0.41, p = 0.004 and beta = - 0.38, p = 0.03, respectively; multivariate models). Greater Li mAge attenuation (multivariate models adjusted for age, sex, baseline mAge, and weight loss) was mostly affected by higher intake of Mankai (beta = - 1.8; p = 0.061) and green tea (beta = - 1.57; p = 0.0016) and corresponded with elevated urine polyphenols: hydroxytyrosol, tyrosol, and urolithin C (p < 0.05 for all) and urolithin A (p = 0.08), highly common in green plants. Overall, participants undergoing either MED-style diet had ~ 8.9 months favorable difference between the observed and expected Li mAge at the end of the intervention (p = 0.02). CONCLUSIONS: This study showed that MED and green-MED diets with increased polyphenols intake, such as green tea and Mankai, are inversely associated with biological aging. To the best of our knowledge, this is the first clinical trial to indicate a potential link between polyphenol intake, urine polyphenols, and biological aging. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03020186.

Air-liquid interface cultures trigger a metabolic shift in intestinal epithelial cells (IPEC-1).

An improved oxygen availability in air-liquid interface (ALI) cultures of enterocytes of the small intestine seems to be primarily responsible for morphological, metabolic, and functional changes. Intestinal porcine epithelial cells 1 (IPEC-1) are less investigated and are rarely used as model for intestinal barrier but showed a profound change of cell shape during ALI cultivation. We aim to answer the following question: Are the observed morphological effects accompanied by changes in metabolic function? A microarray analysis of submerged culture (SMC) and ALI cultures identified 830 significantly regulated genes. Subsequent functional clustering revealed alterations in 31 pathways, with the highest number of regulated genes in metabolic pathways, carbon metabolism, glycolysis, and hypoxia-inducible factor (HIF) signaling. Furthermore, HIF-1α as a mediator of a metabolic switch between glycolysis and oxidative phosphorylation showed a trend of increased mRNA levels in ALI in contrast to a reduced nuclear HIF-1α content in the nucleus. Candidate genes of oxidative phosphorylation such as a mitochondrial marker exhibited enhanced mRNA levels, which was confirmed by western blot analysis. Cytochrome C oxidase (COX) subunit 5B protein was decreased in ALI, although mRNA level was increased. The oxidation of ferrocytochrome C to ferricytochrome C was used for detection of cytochrome C oxidase activity of isolated mitochondria and resulted in a trend of higher activity in ALI. Furthermore, quantification of glucose and lactate concentrations in cell culture medium revealed significantly reduced glucose levels and decreased lactate production in ALI. To evaluate energy metabolism, we measured cellular adenosine triphosphate (ATP) aggregation in homogenized cell suspensions showing similar levels. However, application of the uncoupling agent FCCP reduced ATP levels in ALI but not in SMC. In contrast, blocking with 2-desoxy-D-glucose (2DG) significantly reduced ATP content in ALI and SMC. These results indicate a metabolic shift in IPEC-1 cultured under ALI conditions enhancing oxidative phosphorylation and suppressing glycolysis.

Placental thromboinflammation impairs embryonic survival by reducing placental thrombomodulin expression.

Excess platelet activation by extracellular vesicles (EVs) results in trophoblast inflammasome activation, interleukin 1ß (IL-1ß) activation, preeclampsia (PE), and partial embryonic lethality. Embryonic thrombomodulin (TM) deficiency, which causes embryonic lethality hallmarked by impaired trophoblast proliferation, has been linked with maternal platelet activation. We hypothesized that placental TM loss, platelet activation, and embryonic lethality are mechanistically linked to trophoblast inflammasome activation. Here, we uncover unidirectional interaction of placental inflammasome activation and reduced placental TM expression: although inflammasome inhibition did not rescue TM-null embryos from lethality, the inflammasome-dependent cytokine IL-1ß reduced trophoblast TM expression and impaired pregnancy outcome. EVs, known to induce placental inflammasome activation, reduced trophoblast TM expression and proliferation. Trophoblast TM expression correlated negatively with IL-1ß expression and positively with platelet numbers and trophoblast proliferation in human PE placentae, implying translational relevance. Soluble TM treatment or placental TM restoration ameliorated the EV-induced PE-like phenotype in mice, preventing placental thromboinflammation and embryonic death. The lethality of TM-null embryos is not a consequence of placental NLRP3 inflammasome activation. Conversely, EV-induced placental inflammasome activation reduces placental TM expression, promoting placental and embryonic demise. These data identify a new function of placental TM in PE and suggest that soluble TM limits thromboinflammatory pregnancy complications.

Different DOACs Control Inflammation in Cardiac Ischemia-Reperfusion Differently.

RATIONALE: While thrombin is the key protease in thrombus formation, other coagulation proteases, such as fXa (factor Xa) or aPC (activated protein C), independently modulate intracellular signaling via partially distinct receptors. OBJECTIVES: To study the differential effects of fXa or fIIa (factor IIa) inhibition on gene expression and inflammation in myocardial ischemia-reperfusion injury. METHODS AND RESULTS: Mice were treated with a direct fIIa inhibitor (fIIai) or direct fXa inhibitor (fXai) at doses that induced comparable anticoagulant effects ex vivo and in vivo (tail-bleeding assay and FeCl3-induced thrombosis). Myocardial ischemia-reperfusion injury was induced via left anterior descending ligation. We determined infarct size and in vivo aPC generation, analyzed gene expression by RNA sequencing, and performed immunoblotting and ELISA. The signaling-only 3K3A-aPC variant and inhibitory antibodies that blocked all or only the anticoagulant function of aPC were used to determine the role of aPC. Doses of fIIai and fXai that induced comparable anticoagulant effects resulted in a comparable reduction in infarct size. However, unbiased gene expression analyses revealed marked differences, including pathways related to sterile inflammation and inflammasome regulation. fXai but not fIIai inhibited sterile inflammation by reducing the expression of proinflammatory cytokines (IL [interleukin]-1ß, IL-6, and TNFα [tumor necrosis factor alpha]), as well as NF-κB (nuclear factor kappa B) and inflammasome activation. This anti-inflammatory effect was associated with reduced myocardial fibrosis 28 days post-myocardial ischemia-reperfusion injury. Mechanistically, in vivo aPC generation was higher with fXai than with fIIai. Inhibition of the anticoagulant and signaling properties of aPC abolished the anti-inflammatory effect associated with fXai, while inhibiting only the anticoagulant function of aPC had no effect. Combining 3K3A-aPC with fIIai reduced the inflammatory response, mimicking the fXai-associated effect. CONCLUSIONS: We showed that specific inhibition of coagulation via direct oral anticoagulants had differential effects on gene expression and inflammation, despite comparable anticoagulant effects and infarct sizes. Targeting individual coagulation proteases induces specific cellular responses unrelated to their anticoagulant effect.

Challenge in hyponatremic patients - the potential of a laboratory-based decision support system for hyponatremia to improve patient's safety.

OBJECTIVES: Hyponatremia is the most frequent electrolyte disorder in hospitalized patients with increased mortality and morbidity. In this study, we evaluated the follow-up diagnostic, the risk of inadequate fast correction and the outcome of patients with profound hyponatremia (pHN), defined as a blood sodium concentration below 120 mmol/L. The aim was to identify a promising approach for a laboratory-based clinical decision support system (CDSS). METHODS: This retrospective study included 378,980 blood sodium measurements of 83,315 cases at a German tertiary care hospital. Hospitalized cases with pHN (n=211) were categorized into two groups by the time needed for a follow-up measurement to be performed (time to control, TTC) as either <12 h (group 1: "TTC≤12 h", n=118 cases) or >12 h (group 2: "TTC>12 h", n=93 cases). Length of hospital stay, sodium level at discharge, ward transfers, correction of hyponatremia, and risk of osmotic demyelination syndrome (ODS) due to inadequate fast correction were evaluated with regard to the TTC of sodium blood concentration. RESULTS: pHN was detected in 1,050 measurements (0.3%) in 211 cases. Cases, in which follow-up diagnostics took longer (TTC>12 h), achieved a significantly lower sodium correction during their hospitalization (11.2 vs. 16.7 mmol/L, p<0.001), were discharged more frequently in hyponatremic states (<135 mmol/L; 58 (62.4%) vs. 43 (36.4%), p<0.001) and at lower sodium blood levels (131.2 vs. 135.0 mmol/L, p<0.001). Furthermore, for these patients there was a trend toward an increased length of hospital stay (13.1 vs. 8.5 days, p=0.089), as well as an increased risk of inadequate fast correction (p<0.001). CONCLUSIONS: Our study shows that less frequent follow-up sodium measurements in pHN are associated with worse outcomes. Patients with a prolonged TTC are at risk of insufficient correction of hyponatremia, reduced sodium values at discharge, and possible overcorrection. Our results suggest that a CDSS that alerts treating physicians when a control time of >12 h is exceeded could improve patient care in the long term. We are initiating a prospective study to investigate the benefits of our self-invented CDSS (www.ampel.care) for patients with pHN.

Evidence-based cutoffs for total and adjusted calcium: a major factor in detecting severe hypo- and hypercalcemia.

OBJECTIVES: Severe hypo- and hypercalcemia are common and urgent treatment is recommended. Free calcium (fCa) is the gold standard but needs blood gas tests with challenging preanalytics. Total calcium (tCa) and calculated adjusted calcium (aCa) are readily available, but their interpretation is hampered by identical tCa and aCa cutoffs, laborious local aCa calculation and difficult comparability of calcium biomarkers. METHODS: Laboratory results from University Medicine Leipzig were evaluated over a five-year period (236,274 patients). A local aCa equation was derived by linear least squares regression, the agreement between fCa, tCa and aCa assessed with Cohen's κ and decision thresholds derived by this indirect method. RESULTS: The local aCa equation was created from data of 9,756 patients, each with one paired measurement of tCa, fCa and albumin. Derived aCa cutoffs (1.95/3.15 mmol/L) differ markedly from derived tCa cutoffs (1.6/2.9 mmol/L) and severe hypo- and hypercalcemia can be more accurately assessed by aCa (κ=0.489, 0.812) than by tCa (κ=0.445, 0.744). Comparing our approach to standard care (tCa, literature cutoff), a total 3,250 of 3,680 (88.3 %) misclassified measurements were correctly classified when using aCa with evidence-based cutoffs. CONCLUSIONS: Optimized cutoffs for aCa and tCa hold great potential for improved patient care. Locally derived aCa equations differ mostly in the chosen mean normal calcium and provide minimal overall improvement, but entail a close examination of the used cutoffs before application.

Higher troponin T serum concentrations in hospital patients without diagnosed cardiac diseases compared to a population-based cohort.

OBJECTIVES: Upper reference limits of high-sensitivity cardiac troponin T (hs-cTnT) are derived from healthy, population-based cohorts, and are frequently exceeded in hospitalized patients. In this study we aim to systematically examine the differences between in-hospital patients with no diagnosed cardiac diseases and a population-based cohort. METHODS: Retrospective analyses were performed in two independent cohorts. We included 5,652 participants of the prospective population-based LIFE cohort as well as 9,300 patients having been treated at our hospital between 2014 and 2021. In both cohorts, subjects with diagnosed or suspected cardiac diseases were excluded. We used Spearman's rank correlation for correlation analyses of hs-cTnT serum concentrations and age. Sex- and age-adjusted 99th percentiles for hs-cTnT in subjects with preserved renal function were obtained in both cohorts. RESULTS: In both cohorts, hs-cTnT serum concentrations positively correlated with age. Male sex was associated with higher hs-cTnT serum concentrations. Persons treated in hospital showed significantly higher hs-cTnT concentrations in females and males aged above 50. While in the population-based cohort only 99th percentile hs-cTnT results of females aged above 70 and males aged above 60 years exceeded the assay's upper reference limit, the 99th percentiles of in-hospital females over 40 years and males of all age groups exceeded this threshold. CONCLUSIONS: Besides age and sex, hospitalization per se is correlated with higher serum concentrations of hs-cTnT in most age groups. Our results indicate, that unconditionally applying current hs-cTnT cut-offs to inpatients might overestimate myocardial infarction and potentially lead to overdiagnosis.

Podocyte-specific Nlrp3 inflammasome activation promotes diabetic kidney disease.

Efficient therapies for diabetic kidney disease (DKD), now the leading cause of kidney failure, are lacking. One hallmark of DKD is sterile inflammation (inflammation in absence of microorganisms), but the underlying molecular mechanisms remain poorly understood. The NLRP3 inflammasome (innate immune system receptors and sensors regulating activation of caspase-1) is a mechanism of sterile inflammation known to be activated by metabolic stimuli and reactive metabolites associated with DKD, including inflammasome activation in podocytes. However, whether NLRP3 inflammasome activation in podocytes contributes to sterile inflammation and glomerular damage in DKD remains unknown. Here, we found that kidney damage, as reflected by increased albuminuria, glomerular mesangial expansion and glomerular basement membrane thickness was aggravated in hyperglycemic mice with podocyte-specific expression of an Nlrp3 gain-of-function mutant (Nlrp3A350V). In contrast, hyperglycemic mice with podocyte-specific Nlrp3 or Caspase-1 deficiency showed protection against DKD. Intriguingly, podocyte-specific Nlrp3 deficiency was fully protective, while podocyte-specific caspase-1 deficiency was only partially protective. Podocyte-specific Nlrp3, but not caspase-1 deficiency, maintained glomerular autophagy in hyperglycemic mice, suggesting that podocyte Nlrp3 exerts both canonical and non-canonical effects. Thus, podocyte NLRP3 inflammasome activation is both sufficient and required for DKD and supports the concept that podocytes exert some immune cell-like functions. Hence, as podocyte NLRP3 exerts non-canonical and canonical effects, targeting NLRP3 may be a promising therapeutic approach in DKD.

The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial.

BACKGROUND: Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). METHODS: In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3-4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. RESULTS: Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: - 2.7%, green-MED: - 3.9%) and waist circumference (MED: - 4.7%, green-MED: - 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: - 4.2%, MED: - 6.0%, green-MED: - 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). CONCLUSIONS: A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03020186.

High salt diet-induced proximal tubular phenotypic changes and sodium-glucose cotransporter-2 expression are coordinated by cold shock Y-box binding protein-1.

High salt diet (HSD) is a hallmark of blood pressure elevations, weight gain and diabetes onset in the metabolic syndrome. In kidney, compensatory mechanisms are activated to balance salt turnover and maintain homeostasis. Data on the long-term effects of HSD with respect to tubular cell functions and kidney architecture that exclude confounding indirect blood pressure effects are scarce. Additionally we focus on cold shock Y-box binding protein-1 as a tubular cell protective factor. A HSD model (4% NaCl in chow; 1% NaCl in water) was compared to normal salt diet (NSD, standard chow) over 16 months using wild type mice and an inducible conditional whole body knockout for cold shock Y-box binding protein-1 (BL6J/N, Ybx1). HSD induced no difference in blood pressure over 16 months, comparing NSD/HSD and Ybx1 wild type/knockout. Nevertheless, marked phenotypic changes were detected. Glucosuria and subnephrotic albuminuria ensued in wild type animals under HSD, which subsided in Ybx1-deficient animals. At the same time megalin receptors were upregulated. The sodium-glucose cotransporter-2 (SGLT2) was completely downregulated in wild type HSD animals that developed glucosuria. In Ybx1 knockouts, expression of AQP1 and SGLT2 was maintained under HSD; proximal tubular widening and glomerular tubularization developed. Concurrently, amino aciduria of neutral and hydrophobic amino acids was seen. In vitro translation confirmed that YB-1 translationally represses Sglt2 transcripts. Our data reveal profound effects of HSD primarily within glomeruli and proximal tubular segments. YB-1 is regulated by HSD and orchestrates HSD-dependent changes; notably, sets reabsorption thresholds for amino acids, proteins and glucose.