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The mortality rate for acute kidney injury (AKI) due to sepsis remains high, and effective therapies based on its pathogenesis remain elusive. Macrophages are crucial for clearing bacteria from vital organs, including the kidney, under septic conditions. Excessive macrophage activation results in organ injury. C-reactive protein (CRP) peptide (174-185), a functional product of proteolyzed CRP in vivo, effectively activates macrophages. We investigated the therapeutic efficacy of synthetic CRP peptide on septic AKI, focusing on effects on kidney macrophages. Mice underwent cecal ligation and puncture (CLP) to induce septic AKI and were intraperitoneally administered 20 mg/kg of synthetic CRP peptide 1 h post-CLP. Early CRP peptide treatment improved AKI while still clearing infection. Ly6C-negative kidney tissue-resident macrophages did not significantly increase at 3 h after CLP, while Ly6C-positive monocyte-derived macrophages significantly accumulated in the kidney 3 h post-CLP. CRP peptide augmented the phagocytic ROS production in both subtypes of kidney macrophage at 3 h. Interestingly, both subtypes of macrophage increased ROS production 24 h post-CLP compared to the control group, while CRP peptide treatment maintained ROS production at the same level seen 3 h post-CLP. Although bacterium-phagocytic kidney macrophages produced TNF-α, CRP peptide reduced bacterial propagation and tissue TNF-α levels in the septic kidney at 24 h. Although both subsets of kidney macrophages showed populations of M1 at 24 h post-CLP, CRP peptide therapy skewed the macrophages population toward M2 at 24 h. CRP peptide alleviated murine septic AKI via the controlled activation of kidney macrophages and is an excellent candidate for future human therapeutic studies.

Recent studies have revealed that mammalian B cells ingest particulate Ags, such as bacteria, although little is known about the effect of this function on acquired immunity. We investigated the role of bacterium-phagocytosing B cells in acquired host immune responses. Cultured mouse liver B cells substantially phagocytosed serum-opsonized Streptococcus pneumoniae and produced IgM. On adoptive transfer of liver B cells that phagocytose S. pneumoniae labeled with pHrodo Red succinimidyl ester, recipient mice showed elevated plasma levels of IgG specific for bacterial Ags. In particular, the levels of IgG2a and IgG2b specific for pneumococcal surface protein A, as well as IgG3 for pneumococcal polysaccharide, were markedly increased compared with total IgG specific for each Ag. When phagocytic liver B cells were cultured with spleen CD4+ T cells obtained from mice primed with heat-killed S. pneumoniae 7 d before, they induced IL-2 production and proliferation of the CD4+ T cells, along with Th1 cytokine production. However, they induced neither the CD4+ T cell production of IL-21, a suggested marker promoting B cell proliferation and differentiation, nor the expression of genes important for somatic hypermutation or isotype switching; such responses were particularly evident when splenic B cells merely capturing S. pneumoniae without processing them were cultured with spleen CD4+ T cells. These findings suggest that phagocytic liver B cells may be involved in acquired immune responses by presenting derivative peptides to CD4+ T cells without their own somatic hypermutation or isotype switching.

Fatty liver index (FLI), which is calculated by using body mass index, waist circumference and levels of γ-glutamyl transferase and triglycerides, is a validated surrogate marker of nonalcoholic fatty liver disease. We retrospectively investigated the relationship between FLI and the development of ischemic heart disease (IHD) during a 10-year period.Among subjects who received annual health checkups (n = 28 990), a total of 18 851 subjects (men/women: 11 659/7192) were enrolled after exclusion of subjects with missing data and those with IHD at baseline.FLI at baseline was significantly higher in men than in women. During the 10-year period, 450 men (3.9%) and 123 women (1.7%) had new onset of IHD determined by a self-reported questionnaire survey. Multivariable Cox proportional hazard models with a restricted cubic spline showed that hazard risk (HR) for the development of IHD increased with a higher FLI at baseline after adjustment of age, sex, current smoking habit, family history of IHD and diagnosis of diabetes mellitus, hypertension, dyslipidemia and chronic kidney disease at baseline. There was no significant interaction between FLI and sex for the adjusted HR. When divided by tertiles of FLI at baseline (T1∼T3), the adjusted risk for development of IHD in the T3 group (HR [95% confidence interval]: 1.34 [1.05-1.71]) was significantly higher than that in the T1 group as the reference. The addition of FLI into traditional risk factors for IHD significantly improved the discriminatory capability.A high level of FLI is an independent predictor of new onset of IHD during a 10-year period.

Music can evoke pleasurable and rewarding experiences. Past studies that examined task-related brain activity revealed individual differences in musical reward sensitivity traits, and linked them to interactions between the auditory and reward systems. However, state-dependent fluctuations in spontaneous neural activity in relation to music-driven rewarding experiences have not been studied. Here, we used functional MRI (N=49) to examine whether the coupling of auditory-reward networks during a silent period immediately before music listening can predict the degree of musical rewarding experience. We used machine learning models and showed that the functional connectivity between auditory and reward networks, but not others, could robustly predict subjective, physiological, and neurobiological aspects of the strong musical reward of chills. Specifically, the right auditory cortex-striatum/orbitofrontal connections were related to neural positive arousal responses, whereas the auditory-amygdala connection was associated with physiological arousal. Moreover, the predictive model of auditory-reward network derived from one sample of individuals replicated in an independent dataset using different music samples. The current study reveals the role of pre-task brain state in efficiently connecting sensory and reward systems leading to an intensely rewarding experience.

Previous studies indicated that active interactions on social networking services (SNS) are positively linked to subjective well-being (SWB). However, how semantic SNS content affects the association between the degree of SNS interaction and SWB has not been investigated. We addressed this issue by conducting a mediation analysis using natural language processing. We first analyzed Twitter data and SWB scores from 217 participants and found that the degree of active interactions on Twitter (i.e., frequency of reply) was positively correlated with SWB. Next, our multivariate mediation analysis demonstrated that positive words served as SWB-promoting mechanisms for highly interactive people, whereas worrying words led to lower SWB for less interactive people, but negative words did not. This study revealed that natural language content explains why individuals who are highly interactive on SNS have higher SWB, whereas less interactive individuals show lower SWB.

Facial expressions are produced by specific muscle movements. Although past studies have investigated the association between the facial action unit (AU) and emotion, how the intensity and speed of movement contribute to each emotion is unknown. Here, to reveal the role of intensity and speed cues for facial emotion recognition, we examined the machine learning model with AUs extracted using the computer vision method. Participants (n = 39) classified the stimuli of dynamic facial expressions into six emotions. Using the two-dimensional AU features of the stimuli, the machine learning models classified emotion with high accuracy. From the classification model’s contribution weighting, we found the emotion-related specificity of the intensity and speed cues. The strong contribution of intensity was for happiness, whereas speed was for anger and surprise. Sadness, fear, and disgust were not clearly differentiated by intensity and speed. Our findings suggest that people judge facial emotions by balancing appropriate intensity and speed cues.

Background Possible associations of chronic kidney disease (CKD) with fatty liver (FL) and nonalcoholic fatty liver disease (NAFLD) have recently been focused on. Metabolic dysfunction–associated fatty liver disease (MAFLD), defined as FL with overweight/obesity, type 2 diabetes mellitus or metabolic abnormalities, has been proposed as a new feature of chronic liver disease. However, the relationship between MAFLD and new onset of CKD has not been fully addressed. Methods We investigated the associations of FL, NAFLD and MAFLD with the development of CKD, defined as an estimated glomerular filtration rate (eGFR) Results The prevalence of FL, NAFLD and MAFLD was 34.6% (men 45.1%, women 15.1%), 32.8% (men 42.7%, women 14.5%) and 32.3% (men 42.4%, women 13.4%), respectively. During the 10-year follow-up period, 2163 subjects (men 1475, women 688) had new onset of CKD. Multivariable Cox proportional hazards model analyses showed that MAFLD [hazard ratio 1.12 (95% confidence interval 1.02–1.26); P = .027] but not FL or NAFLD was an independent risk factor for new onset of CKD after adjustment of age, sex, eGFR, current smoking habit, ischemic heart disease, diabetes mellitus, overweight/obesity, hypertension and dyslipidemia. The addition of MAFLD [continuous net reclassification improvement (NRI) 0.154, integrated discrimination improvement (IDI) 0.0024] to traditional risk factors without metabolic abnormalities significantly improved the discriminatory capacity better than did the addition of FL (NRI 0.138, IDI 0.0018) or NAFLD (NRI 0.132, IDI 0.0017). Conclusions MAFLD is modestly and independently associated with new onset of CKD and predicts the risk for development of CKD better than FL or NAFLD.

Aims The fibrosis-4 (FIB-4) index, calculated using age, platelet count, and levels of aspartate aminotransferase and alanine aminotransferase, is a non-invasive indicator for the detection of liver fibrosis. Advanced hepatic fibrosis is associated with morbidity and mortality in patients with non-alcoholic fatty liver disease. However, the relationship between liver fibrosis and the development of ischaemic heart disease (IHD) has not fully been addressed. Methods and results We investigated the association between the FIB-4 index and the new onset of IHD during a 10-year period in a general population of subjects who received annual health examinations (n = 28 990). After exclusion of subjects with missing data and those with a history of IHD at baseline, a total of 13 448 subjects (men/women: 8774/4674, mean age: 48 years) were included. During the 10-year period, 378 men (4.3%) and 77 women (1.6%) had a new onset of IHD. Multivariable Cox proportional hazard models with a restricted cubic spline showed that hazard risk for the development of IHD increased with a higher FIB-4 index at baseline after adjustment of age, sex, fatty liver (FL) determined by ultrasonography, estimated glomerular filtration rate, habits of current smoking and alcohol drinking, family history of IHD, and diagnosis of hypertension, diabetes mellitus and dyslipidaemia. When divided by FL, the FIB-4 index becomes an independent predictor for the development of IHD in subjects with FL but not in those without FL. The addition of the FIB-4 index to traditional risk factors for IHD significantly improved the discriminatory capability. Conclusion A high level of the FIB-4 index predicts the new onset of IHD during a 10-year period.

The size of an individual active social network is a key parameter of human social behavior and is correlated with subjective well-being. However, it remains unknown how the social network size of active interactions is represented in the brain. Here, we examined whether resting-state functional magnetic resonance imaging (fMRI) connectivity is associated with the social network size of active interactions using behavioral data of a large sample (N = 222) on Twitter. Region of interest (ROI)-to-ROI analysis, graph theory analysis, seed-based analysis, and decoding analysis together provided compelling evidence that people who have a large social network size of active interactions, as measured by "reply," show higher fMRI connectivity of the left inferior frontal gyrus with the dorsomedial prefrontal cortex and temporoparietal junction, which represents the core of the theory of mind network. These results demonstrated that people who have a large social network size of active interactions maintain activity of the identified functional connectivity in daily life, possibly providing a mechanism for efficient information transmission between the brain networks related to language and theory-of-mind.

Current in vivo developmental neurotoxicity (DNT) tests are not performed routinely for chemical risk assessment because they are time and resource intensive and require many animals. Therefore, new methodologies are required that can detect and evaluate the DNT potential of chemicals in a more simple, quantitative, and objective manner. Toward this end, we generated transgenic mice expressing reporter genes (luciferase and lacZ) under the control of the rat synapsin 1 promoter (Syn-Rep mice) and evaluated their usefulness as a DNT detection tool. Brain luciferase expression levels in Syn-Rep mice increased dramatically from just before to after birth, peaked early in the postnatal period, subsequently decreased sharply, and then remained low after weaning. This pattern is analogous to the generally recognized temporal changes in synapse numbers in the developing mammal brain. To evaluate further the responsiveness of Syn-Rep mice during DNT induction, we administered valproic acid (VPA), a reference DNT-inducing chemical, to pregnant mice and evaluated its effect on reporter gene expression in the developing brains of Syn-Rep pups. In vivo luminescence in the brains of VPA-exposed pups was significantly lower than in controls from postnatal days 4 to 13. Moreover, luciferase activity in the prefrontal cortexes of 8-week-old VPA-exposed offspring was significantly lower than in controls, reflecting the reduced number of neurons in the prefrontal cortex. These results suggest that the Syn-Rep mice are potentially useful tools for streamlined detection of chemical-induced DNT in the developing mammalian brain.