Higher Frequency of Premature Atrial Contractions Correlates With Atrial Fibrillation Detection after Cryptogenic Stroke.

BACKGROUND: Covert atrial fibrillation (AF) is a major cause of cryptogenic stroke. This study investigated whether a dose-dependent relationship exists between the frequency of premature atrial contractions (PACs) and AF detection in patients with cryptogenic stroke using an insertable cardiac monitor (ICM). METHODS: We enrolled consecutive patients with cryptogenic stroke who underwent ICM implantation between October 2016 and September 2020 at 8 stroke centers in Japan. Patients were divided into 3 groups according to the PAC count on 24-hour Holter ECG: ≤200 (group L), >200 to ≤500 (group M), and >500 (group H). We defined a high AF burden as above the median of the cumulative duration of AF episodes during the entire monitoring period. We evaluated the association of the frequency of PACs with AF detection using log-rank trend test and Cox proportional hazard model and with high AF burden using logistic regression model, adjusting for age, sex, CHADS2 score. RESULTS: Of 417 patients, we analyzed 381 patients with Holter ECG and ICM data. The median age was 70 (interquartile range, 59.5-76.5), 246 patients (65%) were males, and the median duration of ICM recording was 605 days (interquartile range, 397-827 days). The rate of new AF detected by ICM was higher in groups with more frequent PAC (15.5%/y in group L [n=277] versus 44.0%/y in group M [n=42] versus 71.4%/y in group H [n=62]; log-rank trend P<0.01). Compared with group L, the adjusted hazard ratios for AF detection in groups M and H were 2.11 (95% CI, 1.24-3.58) and 3.23 (95% CI, 2.07-5.04), respectively, and the adjusted odds ratio for high AF burden in groups M and H were 2.57 (95% CI, 1.14-5.74) and 4.25 (2.14-8.47), respectively. CONCLUSIONS: The frequency of PACs was dose-dependently associated with AF detection in patients with cryptogenic stroke.

Medium-chain triglyceride-specific appetite is regulated by the ß-oxidation of medium-chain fatty acids in the liver.

Most studies on fat appetite have focused on long-chain triglycerides (LCTs) due to their obesogenic properties. Medium-chain triglycerides (MCTs), conversely, exhibit antiobesogenic effects; however, the regulation of MCT intake remains elusive. Here, we demonstrate that mice can distinguish between MCTs and LCTs, and the specific appetite for MCTs is governed by hepatic ß-oxidation. We generated liver-specific medium-chain acyl-CoA dehydrogenase (MCAD)-deficient (MCADL-/-) mice and analyzed their preference for MCT and LCT solutions using glyceryl trioctanoate (C8-TG), glyceryl tridecanoate (C10-TG), corn oil, and lard oil in two-bottle choice tests conducted over 8 days. In addition, we used lick microstructure analyses to evaluate the palatability and appetite for MCT and LCT solutions. Finally, we measured the expression levels of genes associated with fat ingestion (Galanin, Qrfp, and Nmu) in the hypothalamus 2 h after oral gavage of fat. Compared with control mice, MCADL-/- mice exhibited a significantly reduced preference for MCT solutions, with no alteration in the preference for LCTs. Lick analysis revealed that MCADL-/- mice displayed a significantly decreased appetite for MCT solutions only while the palatability of both MCT and LCT solutions remained unaffected. Hypothalamic Galanin expression in control mice was elevated by oral gavage of C8-TG but not by LCTs, and this response was abrogated in MCADL-/- mice. In summary, our data suggest that hepatic ß-oxidation is required for MCT-specific appetite but not for LCT-specific appetite. The induction of hypothalamic galanin upon MCT ingestion, dependent on hepatic ß-oxidation, could be involved in the regulation of MCT-specific appetite.NEW & NOTEWORTHY Whether and how medium-chain triglyceride (MCT) intake is regulated remains unknown. Here, we showed that mice can discriminate between MCTs and LCTs. Hepatic ß-oxidation participates in MCT-specific appetite, and hypothalamic galanin may be one of the factors that regulate MCT intake. Because of the antiobesity effects of MCTs, studying MCT-specific appetite may help combat obesity by promoting the intake of MCTs instead of LCTs.

One-year morbidity and mortality in patients treated with standard-dose and low-dose apixaban after acute large vessel occlusion stroke.

Although low-dose direct oral anticoagulants (DOACs) are recommended for patients at high risk of bleeding complications, it remains unclear whether the dose reduction in real-world setting is also appropriate in patients after large-vessel occlusion (LVO) stroke. This study hypothesized that patients with atrial fibrillation (AF) and LVO receiving low-dose DOACs have an increased risk of ischemic and hemorrhagic events. The study aimed to assess 1 year morbidity and mortality in patients treated with standard-dose and low-dose apixaban after LVO stroke. A post hoc analysis was performed using the acute LVO registry data, which enrolled patients with AF and LVO who received apixaban within 14 days of stroke onset. The incidences of ischemic events (ischemic stroke, acute coronary syndrome, acute myocardial infarction, and systemic embolism), major bleeding events, and death from any cause were compared between patients receiving standard- and low-dose apixaban. Of 643 patients diagnosed with LVO, 307 (47.7%) received low-dose apixaban. After adjustment for clinically relevant variables, no significant differences were observed in the incidence of ischemic events (adjusted hazard ratio [aHR]: 2.12, 95% confidence interval [CI] 0.75-6.02), major bleeding events (aHR: 1.17, 95% CI 0.50-2.73), and death from any cause (aHR: 1.95, 95% CI 0.78-4.89) between patients receiving standard- and low-dose apixaban. No significant differences were observed in the incidence of ischemic events, major bleeding events, or death from any cause between patients with AF and LVO receiving standard- and low-dose apixaban.

R-spondin 3/LGR4 (Leucine-Rich Repeat-Containing G Protein-Coupled Receptor 4) Axis Is a Novel Inflammatory and Neurite Outgrowth Signaling System in the Ischemic Brain in Mice.

BACKGROUND: Although stimulation of Wnt/ß-catenin signaling is an important strategy to treat ischemic stroke, its signaling pathway has not been fully clarified yet. Recently, RSPO3 (R-spondin 3)/LGR4 (leucine-rich repeat-containing G protein-coupled receptor 4) signaling has resolved TLR4 (toll-like receptor 4)-induced inflammation in lung injury; however, whether this signal is critical in the ischemic brain remains unknown. Therefore, we investigated the role of RSPO3/LGR4 signaling in the ischemic brain. METHODS: BALB/c mice were exposed to permanent distal middle cerebral artery and common carotid artery occlusion. Temporal RSPO3 and LGR4 expressions were examined, and the mice were randomly assigned to receive vehicle or recombinant RSPO3. The underlying mechanisms were investigated using microglial cell lines and primary mixed glia-endothelia-neuron and primary neuronal cultures. RESULTS: In the ischemic brain, RSPO3 and LGR4 were expressed in endothelial cells and microglia/macrophages and neurons, respectively. Stimulation of RSPO3/LGR4 signaling by recombinant RSPO3 recovered neurological deficits with decreased Il1ß and iNOS mRNA on day 3 and increased Gap43 on day 9. In cultured cells, LGR4 was expressed in neuron and microglia, whereas RSPO3 promoted nuclear translocation of ß-catenin. Neuroprotective effects with reduced expression of inflammatory cytokines were observed in lipopolysaccharide-stimulated glia-endothelium-neuron cultures but not in glutamate-, CoCl2-, H2O2-, or oxygen glucose deprivation-stimulated neuronal cultures, indicating that RSPO3/LGR4 can protect neurons by regulating inflammatory cytokines. LGR4-Fc chimera, which was used to block endogenous RSPO3/LGR4 signaling, increased LPS-induced production of inflammatory cytokines, suggesting that endogenous RSPO3 suppresses inflammation. RSPO3 decreased TLR4-related inflammatory cytokine expression by decreasing TLR4 expression without affecting the M1/M2 phenotype. RSPO3 also inhibited TLR2- and TLR9-induced inflammation but not TLR7-induced inflammation, and promoted neurite outgrowth. CONCLUSIONS: RSPO3/LGR4 signaling plays a critical role in regulating TLR-induced inflammation and neurite outgrowth in the ischemic brain. Enhancing this signal will be a promising approach for treating ischemic stroke.

CRTC1 deficiency, specifically in melanocortin-4 receptor-expressing cells, induces hyperphagia, obesity, and insulin resistance.

Melanocortin-4 receptor (MC4R) is a critical regulator of appetite and energy expenditure in rodents and humans. MC4R deficiency causes hyperphagia, reduced energy expenditure, and impaired glucose metabolism. Ligand binding to MC4R activates adenylyl cyclase, resulting in increased levels of intracellular cyclic adenosine monophosphate (cAMP), a secondary messenger that regulates several cellular processes. Cyclic adenosine monophosphate responsive element-binding protein-1-regulated transcription coactivator-1 (CRTC1) is a cytoplasmic coactivator that translocates to the nucleus in response to cAMP and is reportedly involved in obesity. However, the precise mechanism through which CRTC1 regulates energy metabolism remains unknown. Additionally, there are no reports linking CRTC1 and MC4R, although both CRTC1 and MC4R are known to be involved in obesity. Here, we demonstrate that mice lacking CRTC1, specifically in MC4R cells, are sensitive to high-fat diet (HFD)-induced obesity and exhibit hyperphagia and increased body weight gain. Moreover, the loss of CRTC1 in MC4R cells impairs glucose metabolism. MC4R-expressing cell-specific CRTC1 knockout mice did not show changes in body weight gain, food intake, or glucose metabolism when fed a normal-chow diet. Thus, CRTC1 expression in MC4R cells is required for metabolic adaptation to HFD with respect to appetite regulation. Our results revealed an important protective role of CRTC1 in MC4R cells against dietary adaptation.

The PDK1-FoxO1 signaling in adipocytes controls systemic insulin sensitivity through the 5-lipoxygenase-leukotriene B4 axis.

Although adipocytes are major targets of insulin, the influence of impaired insulin action in adipocytes on metabolic homeostasis remains unclear. We here show that adipocyte-specific PDK1 (3'-phosphoinositide-dependent kinase 1)-deficient (A-PDK1KO) mice manifest impaired metabolic actions of insulin in adipose tissue and reduction of adipose tissue mass. A-PDK1KO mice developed insulin resistance, glucose intolerance, and hepatic steatosis, and this phenotype was suppressed by additional ablation of FoxO1 specifically in adipocytes (A-PDK1/FoxO1KO mice) without an effect on adipose tissue mass. Neither circulating levels of adiponectin and leptin nor inflammatory markers in adipose tissue differed between A-PDK1KO and A-PDK1/FoxO1KO mice. Lipidomics and microarray analyses revealed that leukotriene B4 (LTB4) levels in plasma and in adipose tissue as well as the expression of 5-lipoxygenase (5-LO) in adipose tissue were increased and restored in A-PDK1KO mice and A-PDK1/FoxO1KO mice, respectively. Genetic deletion of the LTB4 receptor BLT1 as well as pharmacological intervention to 5-LO or BLT1 ameliorated insulin resistance in A-PDK1KO mice. Furthermore, insulin was found to inhibit LTB4 production through down-regulation of 5-LO expression via the PDK1-FoxO1 pathway in isolated adipocytes. Our results indicate that insulin signaling in adipocytes negatively regulates the production of LTB4 via the PDK1-FoxO1 pathway and thereby maintains systemic insulin sensitivity.

Importance of microRNAs by mRNA-microRNA integration analysis in acute ischemic stroke patients.

OBJECTS: The roles of mRNA and microRNA (miRNA) are well known in many diseases, including ischemic stroke; thus, integration analysis using mRNA and miRNA is important to elucidate pathogenesis. However, their contribution, especially that of miRNA-targeted mRNA, to the severity of acute ischemic stroke remains unclear. Therefore, we examined mRNA and miRNA integration analysis targeted for acute ischemic stroke to clarify the pathway related to acute stroke severity. MATERIAL AND METHODS: We performed Ingenuity Pathway Analysis (IPA) using RNA extracted from the whole blood of four healthy controls, six minor acute ischemic stroke patients (MS; National Institutes of Health Stroke Scale [NIHSS] < 8), and six severe acute ischemic stroke patients (SS; NIHSS ≥ 8) on admission. mRNA and miRNA were measured using RNA sequencing and RNA expression variation; canonical pathway analysis (CPA) and upstream regulator analyses were performed. RESULTS: Acute ischemic stroke patients demonstrated different RNA expressions to healthy controls. Compared to MS patients, in the SS patients, 1222 mRNA, 96 miRNA, and 935 miRNA-targeted mRNA expressions were identified among differentially expressed RNA expressions (p<0.05, |log2 fold change| >1.1). CPA by IPA using mRNAs or miRNA-targeted mRNAs showed that macrophage-stimulating protein (MSP)-recepteur d'origine nantais (RON) signaling was mostly activated in SS patients compared to in MS patients. In addition, upstream regulator analysis in IPA showed that most mRNAs located upstream are miRNAs. CONCLUSIONS: In severe acute stroke, integration of mRNA and microRNA analysis showed activated MSP-RON signaling in macrophages, and multiple miRNAs comprehensively controlled the overall pathophysiology of stroke.

Stimulation of Gs signaling in MC4R cells by DREADD increases energy expenditure, suppresses food intake, and increases locomotor activity in mice.

The melanocortin 4 receptor (MC4R) plays an important role in the regulation of appetite and energy expenditure in humans and rodents. Impairment of MC4R signaling causes severe obesity. MC4R mainly couples to the G-protein Gs. Ligand binding to MC4R activates adenylyl cyclase resulting in increased intracellular cAMP levels. cAMP acts as a secondary messenger, regulating various cellular processes. MC4R can also couple with Gq and other signaling pathways. Therefore, the contribution of MC4R/Gs signaling to energy metabolism and appetite remains unclear. To study the effect of Gs signaling activation in MC4R cells on whole body energy metabolism and appetite, we generated a novel mouse strain that expresses a Gs-coupled designer receptors exclusively activated by designer drugs [Gs-DREADD (GsD)] selectively in MC4R-expressing cells (GsD-MC4R mice). Chemogenetic activation of the GsD by a designer drug [deschloroclozapine (DCZ); 0.01∼0.1 mg/kg body wt] in MC4R-expressing cells significantly increased oxygen consumption and locomotor activity. In addition, GsD activation significantly reduced the respiratory exchange ratio, promoting fatty acid oxidation, but did not affect core (rectal) temperature. A low dose of DCZ (0.01 mg/kg body wt) did not suppress food intake, but a high dose of DCZ (0.1 mg/kg body wt) suppressed food intake in MC4R-GsD mice, although either DCZ dose (0.01 or 0.1 mg/kg body wt) did not affect food intake in the control mice. In conclusion, the current study demonstrated that the stimulation of Gs signaling in MC4R-expressing cells increases energy expenditure and locomotor activity and suppresses appetite.NEW & NOTEWORTHY We report that Gs signaling in melanocortin 4 receptor (MC4R)-expressing cells regulates energy expenditure, appetite, and locomotor activity. These findings shed light on the mechanism underlying the regulation of energy metabolism and locomotor activity by MC4R/cAMP signaling.

Urinary FABP1 is a biomarker for impaired proximal tubular protein reabsorption and is synergistically enhanced by concurrent liver injury.

Urinary fatty acid binding protein 1 (FABP1, also known as liver-type FABP) has been implicated as a biomarker of acute kidney injury (AKI) in humans. However, the precise biological mechanisms underlying its elevation remain elusive. Here, we show that urinary FABP1 primarily reflects impaired protein reabsorption in proximal tubule epithelial cells (PTECs). Bilateral nephrectomy resulted in a marked increase in serum FABP1 levels, suggesting that the kidney is an essential organ for removing serum FABP1. Injected recombinant FABP1 was filtered through the glomeruli and robustly reabsorbed via the apical membrane of PTECs. Urinary FABP1 was significantly elevated in mice devoid of megalin, a giant endocytic receptor for protein reabsorption. Elevation of urinary FABP1 was also observed in patients with Dent disease, a rare genetic disease characterized by defective megalin function in PTECs. Urinary FABP1 levels were exponentially increased following acetaminophen overdose, with both nephrotoxicity and hepatotoxicity observed. FABP1-deficient mice with liver-specific overexpression of FABP1 showed a massive increase in urinary FABP1 levels upon acetaminophen injection, indicating that urinary FABP1 is liver-derived. Lastly, we employed transgenic mice expressing diphtheria toxin receptor (DT-R) either in a hepatocyte- or in a PTEC-specific manner, or both. Upon administration of diphtheria toxin (DT), massive excretion of urinary FABP1 was induced in mice with both kidney and liver injury, while mice with either injury type showed marginal excretion. Collectively, our data demonstrated that intact PTECs have a considerable capacity to reabsorb liver-derived FABP1 through a megalin-mediated mechanism. Thus, urinary FABP1, which is synergistically enhanced by concurrent liver injury, is a biomarker for impaired protein reabsorption in AKI. These findings address the use of urinary FABP1 as a biomarker of histologically injured PTECs that secrete FABP1 into primary urine, and suggest the use of this biomarker to simultaneously monitor impaired tubular reabsorption and liver function. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Application of a novel fluorescence intensity assay: identification of distinct fatty acetates as volatile compounds that bind specifically to amino acid region 149-168 of a transmembrane receptor CD36.

The cluster of differentiation 36 (CD36) is a transmembrane receptor expressed in various cells and has diverse lipid ligands. The expression of CD36 in the murine olfactory epithelium and its ability to recognize certain species of fatty aldehydes, a class of odor-active volatile compounds, have suggested a role for this receptor in the capture of specific odorants in the nasal cavity of mammals. However, the spectrum of CD36-recognizable volatile compounds is poorly understood. In this study, we employed our recently devised assay with fluorescently labeled peptides as probes (fluorescence intensity assay) and identified distinct fatty acetates as volatile compounds that bind specifically to amino acid region 149-168 of CD36 (eg dodecyl and tetradecyl acetates). The present findings demonstrate the utility of our assay for the discovery of novel CD36 ligands and support the notion that the receptor functions as a captor of volatile compounds in the mammalian olfactory system.

CREB Coactivator CRTC2 Plays a Crucial Role in Endothelial Function.

The cAMP pathway is known to stabilize endothelial barrier function and maintain vascular physiology. The family of cAMP-response element binding (CREB)-regulated transcription coactivators (CRTC)1-3 activate transcription by targeting the basic leucine zipper domain of CREB. CRTC2 is a master regulator of glucose metabolism in liver and adipose tissue. However, the role of CRTC2 in endothelium remains unknown. The aim of this study was to evaluate the effect of CRTC2 on endothelial function. We focused the effect of CRTC2 in endothelial cells and its relationship with p190RhoGAP-A. We examined the effect of CRTC2 on endothelial function using a mouse aorta ring assay ex vivo and with photothrombotic stroke in endothelial cell-specific CRTC2-knock-out male mice in vivo CRTC2 was highly expressed in endothelial cells and related to angiogenesis. Among CRTC1-3, only CRTC2 was activated under ischemic conditions at endothelial cells, and CRTC2 maintained endothelial barrier function through p190RhoGAP-A expression. Ser171 was a pivotal regulatory site for CRTC2 intracellular localization, and Ser307 functioned as a crucial phosphorylation site. Endothelial cell-specific CRTC2-knock-out mice showed reduced angiogenesis ex vivo, exacerbated stroke via endothelial dysfunction, and impaired neurologic recovery via reduced vascular beds in vivo These findings suggest that CRTC2 plays a crucial protective role in vascular integrity of the endothelium via p190RhoGAP-A under ischemic conditions.SIGNIFICANCE STATEMENT Previously, the role of CRTC2 in endothelial cells was unknown. In this study, we firstly clarified that CRTC2 was expressed in endothelial cells and among CRTC1-3, only CRTC2 was related to endothelial function. Most importantly, only CRTC2 was activated under ischemic conditions at endothelial cells and maintained endothelial barrier function through p190RhoGAP-A expression. Ser307 in CRTC2 functioned as a crucial phosphorylation site. Endothelial cell-specific CRTC2-knock-out mice showed reduced angiogenesis ex vivo, exacerbated stroke via endothelial dysfunction, and impaired neurologic recovery via reduced vascular beds in vivo These results suggested that CRTC2 maybe a potential therapeutic target for reducing blood-brain barrier (BBB) damage and improving recovery.

The new live imagers MitoMM1/2 for mitochondrial visualization.

Mitochondria are eukaryotic organelles that consist of outer and inner bilayer membranes with a positive potential (H+) in the intermembrane space. This organelle plays an important role in ATP production and apoptosis. To observe the mitochondria in living cells, several fluorescent dyes (such as MitoTracker® [a standard mitochondrial imager] or rhodamine 123) have been developed. However, these reagents are unstable and exhibit a wide range of emission spectra, thereby hampering double staining results. Using recombinant DNA techniques, green or red fluorescent protein (GFP or RFP)-tagged proteins are now available for multi-color labeling of mitochondria. Here, we have discussed the development of the novel mitochondrial live imagers MitoMM1/2, derivatives of ATTO565; furthermore, MitoMM1/2 are sensitive to the membrane potential, resistant to detergents, and the fluorescence of MitoMM1/2 does not overlap with green fluorescence.

Leukotriene A4 hydrolase deficiency protects mice from diet-induced obesity by increasing energy expenditure through neuroendocrine axis.

Obesity is a health problem worldwide, and brown adipose tissue (BAT) is important for energy expenditure. Here, we explored the role of leukotriene A4 hydrolase (LTA4 H), a key enzyme in the synthesis of the lipid mediator leukotriene B4 (LTB4 ), in diet-induced obesity. LTA4 H-deficient (LTA4 H-KO) mice fed a high-fat diet (HFD) showed a lean phenotype, and bone-marrow transplantation studies revealed that LTA4 H-deficiency in non-hematopoietic cells was responsible for this lean phenotype. LTA4 H-KO mice exhibited greater energy expenditure, but similar food intake and fecal energy loss. LTA4 H-KO BAT showed higher expression of thermogenesis-related genes. In addition, the plasma thyroid-stimulating hormone and thyroid hormone concentrations, as well as HFD-induced catecholamine secretion, were higher in LTA4 H-KO mice. In contrast, LTB4 receptor (BLT1)-deficient mice did not show a lean phenotype, implying that the phenotype of LTA4 H-KO mice is independent of the LTB4 /BLT1 axis. These results indicate that LTA4 H mediates the diet-induced obesity by reducing catecholamine and thyroid hormone secretion.

Frequent Premature Atrial Contractions in Cryptogenic Stroke Predict Atrial Fibrillation Detection with Insertable Cardiac Monitoring.

OBJECTIVE: To determine whether frequent premature atrial contractions (PAC) predict atrial fibrillation (AF) in cryptogenic stroke patients, we analyzed the association between frequent PACs in 24-h Holter electrocardiogram recording and AF detected by insertable cardiac monitoring (ICM). METHODS: We retrospectively analyzed a database of 66 consecutive patients with cryptogenic stroke who received ICM implantation between October 2016 and March 2018 at 5 stroke centers. We included the follow-up data until June 2018 in this analysis. We defined frequent PACs as the upper quartile of the 66 patients. We analyzed the association of frequent PACs with AF detected by ICM. RESULTS: Frequent PACs were defined as >222 PACs per a 24-h period. The proportion of patients with newly detected AF by ICM was higher in patients with frequent PACs than those without (50% [8/16] vs. 22% [11/50], p < 0.05). Frequent PACs were associated with AF detection and time to the first AF after adjustment for CHADS2 score after index stroke, high plasma -B-type natriuretic peptide (BNP; >100 pg/mL) or serum -N-terminal pro-BNP levels (>300 pg/mL), and large left atrial diameter (≥45 mm). CONCLUSION: High frequency of PACs in cryptogenic stroke may be a strong predictor of AF detected by ICM.

Zinc transporter ZIP13 suppresses beige adipocyte biogenesis and energy expenditure by regulating C/EBP-ß expression.

Given the relevance of beige adipocytes in adult humans, a better understanding of the molecular circuits involved in beige adipocyte biogenesis has provided new insight into human brown adipocyte biology. Genetic mutations in SLC39A13/ZIP13, a member of zinc transporter family, are known to reduce adipose tissue mass in humans; however, the underlying mechanisms remains unknown. Here, we demonstrate that the Zip13-deficient mouse shows enhanced beige adipocyte biogenesis and energy expenditure, and shows ameliorated diet-induced obesity and insulin resistance. Both gain- and loss-of-function studies showed that an accumulation of the CCAAT/enhancer binding protein-ß (C/EBP-ß) protein, which cooperates with dominant transcriptional co-regulator PR domain containing 16 (PRDM16) to determine brown/beige adipocyte lineage, is essential for the enhanced adipocyte browning caused by the loss of ZIP13. Furthermore, ZIP13-mediated zinc transport is a prerequisite for degrading the C/EBP-ß protein to inhibit adipocyte browning. Thus, our data reveal an unexpected association between zinc homeostasis and beige adipocyte biogenesis, which may contribute significantly to the development of new therapies for obesity and metabolic syndrome.

Hematological Abnormalities and Malnutrition Mediate Pathway between Cancer and Outcomes in Ischemic Stroke Patients.

BACKGROUND: The present study aimed to examine whether variables including D-dimer, high-sensitivity C-reactive protein (hsCRP), hemoglobin, platelet count, and nutritional status mediate the pathway between cancer and ischemic stroke outcomes. METHODS: We reviewed data from consecutive patients with ischemic stroke admitted to Osaka University Hospital between January 1, 2006, and December 31, 2016. Patients with ischemic stroke were grouped according to the presence of cancer. Nutritional status was assessed using Controlling Nutritional Status (CONUT) scores. Mediation analyses were utilized to address the study aims. RESULTS: Among 1,570 patients with ischemic stroke, 185 (12%) had active cancer. Relative to patients with ischemic stroke in the non-cancer group, those in the cancer group exhibited higher National Institutes of Health Stroke Scale scores on admission, higher D-dimer and hsCRP levels, lower hemoglobin levels and platelet counts, higher CONUT scores, and poorer modified Rankin Scale scores at discharge. Mediation analysis revealed that D-dimer, hsCRP, hemoglobin, platelet count, and CONUT scores acted as mediators of poor prognosis in the cancer group. The association between the exposure and outcome variables was no longer significant in the models containing D-dimer and CONUT scores as mediator variables, suggesting that they were strong mediators. Regarding the association between the mediator and outcome variables, hemoglobin, platelet count, and CONUT exhibited non-linearity (p for non-linearity < 0.001). CONCLUSIONS: D-dimer, hsCRP, hemoglobin, platelet count, and CONUT score act as mediators of poor prognosis in patients with ischemic stroke with comorbid cancer. Such abnormalities can help to predict ischemic stroke outcomes.

Total small vessel disease score and functional outcomes following acute intracerebral hemorrhage.

BACKGROUND: Individual cerebral small vessel disease (SVD) markers are independent predictors for poor prognosis following intracerebral hemorrhage (ICH), however, the impact of the cumulative SVD burden on outcomes remains unclear. We aimed to investigate the association between the global SVD burden and functional outcomes following ICH. METHODS: We retrospectively evaluated a consecutive cohort of patients with ICH who underwent brain magnetic resonance imaging and magnetic resonance angiography, from a prospective registry. We identified the presence and severity of the SVD markers (cerebral microbleeds, lacunar infarctions, periventricular hyperintensities, and deep white matter hyperintensities) and summed them to obtain the modified total SVD score (0-4). Poor functional outcomes were defined as a modified Rankin Scale score at discharge ≥ 3. A multivariate logistic regression model was used to assess the association between patient outcomes and the SVD score. RESULTS: A total of 144 patients were included (65.0 ± 12.2 years, 67.4% male). The modified total SVD score was potentially associated with poor functional outcomes (odds ratio [OR] 1.72, 95% confidence interval [CI] 0.97-3.03) after adjustment for age, sex, history of stroke, chronic kidney disease, prior use of antithrombotic agents, the National Institutes of Health Stroke Scale score on admission, the non-lobar location of ICH, and hematoma volume on admission. Moreover, among older patients (≥ 65 years), the SVD score was associated with poor outcomes (OR 3.11, 95% CI 1.01-9.55). Among those with supratentorial ICH, the score remained significant (OR 2.06, 95% CI 1.11-3.83). CONCLUSIONS: The modified total SVD score may have predictive value for poor functional outcomes following ICH.

Cortical Cerebral Microinfarcts on 3T Magnetic Resonance Imaging in Patients With Carotid Artery Stenosis.

Background and Purpose- Carotid artery stenosis is common in the elderly and contributes to cognitive impairment and dementia. Cortical cerebral microinfarcts (CMIs) play an important role in vascular cognitive impairment and dementia. We aimed to investigate the association between CMIs on 3T magnetic resonance imaging and clinical and radiological features, including plaque morphology, and cognitive function in patients with carotid stenosis. Methods- Eighty-nine patients with >30% carotid stenosis on ultrasound were prospectively enrolled, and underwent brain and carotid artery magnetic resonance imaging. CMIs were rated according to predetermined criteria based on 3D-double inversion recovery and fluid-attenuated inversion recovery images. Results- CMIs were identified in 26 patients (29%; median number 0, range 0-9). Poisson regression models adjusted for age and sex revealed that CMIs were associated with intraplaque hemorrhage (rate ratio, 1.95; 95% CI, 1.26-3.18), lacunar infarcts (rate ratio, 1.54; 95% CI, 1.00-2.44), and cortical infarcts (rate ratio, 3.22; 95% CI, 2.20-5.00). These associations were also observed in asymptomatic patients (n=64). Of 81 patients with unilateral carotid stenosis, the prevalence and number of CMIs were significantly higher in the hemisphere ipsilateral to the carotid stenosis than in the contralateral hemisphere ( P=0.005 and P<0.001, respectively). The presence of CMIs was associated with poor cognitive function. Conclusions- Our results indicate that vulnerable carotid plaque increases the risk of CMIs and subsequent cognitive impairment. Carotid atherosclerosis could be a potential therapeutic target for cognitive impairment.

Monitoring of glutamate-induced excitotoxicity by mitochondrial oxygen consumption.

Dysfunction of mitochondrial activity is often associated with the onset and progress of neurodegenerative diseases. Membrane depolarization induced by Na+ influx increases intracellular Ca2+ levels in neurons, which upregulates mitochondrial activity. However, overlimit of Na+ influx and its prolonged retention ultimately cause excitotoxicity leading to neuronal cell death. To return the membrane potential to the normal level, Na+ /K+ -ATPase exchanges intracellular Na+ with extracellular K+ by consuming a large amount of ATP. This is a reason why mitochondria are important for maintaining neurons. In addition, astrocytes are thought to be important for supporting neighboring neurons by acting as energy providers and eliminators of excessive neurotransmitters. In this study, we examined the meaning of changes in the mitochondrial oxygen consumption rate (OCR) in primary mouse neuronal populations. By varying the medium constituents and using channel modulators, we found that pyruvate rather than lactate supported OCR levels and conferred on neurons resistance to glutamate-mediated excitotoxicity. Under a pyruvate-restricted condition, our OCR monitoring could detect excitotoxicity induced by glutamate at only 10 µM. The OCR monitoring also revealed the contribution of the N-methyl-D-aspartate receptor and Na+ /K+ -ATPase to the toxicity, which allowed evaluating spontaneous excitation. In addition, the OCR monitoring showed that astrocytes preferentially used glutamate, not glutamine, for a substrate of the tricarboxylic acid cycle. This mechanism may be coupled with astrocyte-dependent protection of neurons from glutamate-mediated excitotoxicity. These results suggest that OCR monitoring would provide a new powerful tool to analyze the mechanisms underlying neurotoxicity and protection against it.

Carnosol suppresses interleukin-6 production in mouse lungs injured by ischemia-reperfusion operation and in RAW264.7 macrophages treated with lipopolysaccharide.

Carnosol is a naturally occurring herbal compound, known for its antioxidative properties. We previously found that carnosol protected mouse lungs from ischemia-reperfusion injury in ex vivo cultures. To elucidate the molecular mechanisms underpinning carnosol-mediated lung protection, we analyzed modes of interleukin-6 (IL-6) gene expression, which is associated with lung ischemia-reperfusion injury. Microarray analysis of mouse lungs suggested that IL-6 mRNA levels were elevated in the mouse lungs subjected to clamp-reperfusion, which was associated with elevated levels of other inflammatory modulators, such as activating transcription factor 3 (ATF3). Carnosol pretreatment lowered the IL-6 protein levels in mouse lung homogenates prepared after the clamp-reperfusion. On the other hand, the ATF3 gene expression was negatively correlated with that of IL-6 in RAW264.7 cells. IL-6 mRNA levels and gene promoter activities were suppressed by carnosol in RAW264.7 cells, but rescued by ATF3 knockdown. When RAW264.7 cells were subjected to hypoxia-reoxygenation, carnosol treatment lowered oxygen consumption after reoxygenation, which was coupled with a correlation with a transient production of mitochondrial reactive oxygen species and following ATF3 gene expression. These results suggest that carnosol treatment could be a new strategy for protecting lungs from ischemia-reperfusion injury by modulating the ATF3-IL-6 axis.