Pregnancy and childbirth in Takayasu arteritis in Japan: A nationwide retrospective study.

OBJECTIVES: This study aimed to understand the status quo of medical treatments of the primary disease and pregnancy outcomes in patients with Takayasu arteritis (TAK) and children's birth outcomes. METHODS: This study retrospectively enrolled patients with TAK who conceived after the disease onset and were managed at medical facilities participating in the Japan Research Committee of the Ministry of Health, Labor, and Welfare for Intractable Vasculitis. RESULTS: This study enrolled 51 cases and 68 pregnancies 2019-2021. Of these, 48 cases and 65 pregnancies (95.6%) resulted in delivery and live-born babies. The median age of diagnosis and delivery was 22 and 31, respectively. Preconception therapy included prednisolone (PSL) in 51 (78.5%, median 7.5 mg/day), immunosuppressants in 18 (27.7%), and biologics in 12 (18.5%) pregnancies. Six cases underwent surgical treatment before pregnancy. Medications during pregnancy included PSL in 48 (73.8%, median: 9 mg/day), immunosuppressants in 13 (20.0%), and biologics in 9 (13.8%) pregnancies. Enlargement of an aneurysm was reported in one pregnancy, which might be associated with increased circulating plasma volume. TAK relapsed in 4 (6.2%) and 8 (12.3%) pregnancies during pregnancy and after delivery, respectively. Additionally, 13/62 (20.9%) preterm infants and 17/59 (28.8%) low birth weight infants were observed, and none had serious postnatal abnormalities. Of the 51 confirmed infants, 42 (82.4%) were exclusively breastfed or mixed with formula. CONCLUSION: Most pregnancies in TAK were manageable with PSL at ≤10 mg/day. Relapse during pregnancy and postpartum occurred in <20% of pregnancies.

Effects of d-alanine Intake on Amino Acid Metabolism and Kidney Function in Healthy Adults: A Multicenter, Randomized Pilot Study.

Background: d-alanine administration prevented kidney damage in a murine acute kidney injury model. Further data are needed on the influence of d-alanine on kidney function in humans. Objective: This study investigated the effects of d-alanine intake on amino acid metabolism and kidney function in healthy volunteers. Methods: This multicenter pilot study randomly assigned individuals from the general Japanese population to receive 3 g or 6 g of d-alanine intake per day for 7 d in a 1:1 ratio. The primary endpoint was the mean change in plasma and urine d-alanine levels from baseline to 7 d after intake. The secondary endpoints were mean changes in kidney function and other clinical factors. Safety was assessed by evaluating adverse events and clinical parameters. Results: We randomly assigned 24 participants to the 3-g (n = 12) and 6-g d-alanine (n = 12) groups. The mean baseline estimated glomerular filtration rate (eGFR) was 73 mL/min/1.73 m2. The mean plasma d-alanine concentration increased from baseline by 77.5 ± 34.3 and 192.1 ± 80.9 nmol/mL in the 3-g and 6-g d-alanine groups (both p < 0.0001), respectively, in a dose-dependent manner (between-group difference: 114.6 nmol/mL; 95% CI: 62.1-167.2; P = 0.0002). A similar increase was observed for the urine d-alanine to creatinine ratio. The mean eGFR was elevated by 5.7 ± 8.8 mL/min/1.73 m2 in the 6-g d-alanine group (P = 0.045) but did not significantly change in the 3-g d-alanine group. Nonserious adverse events were reported in 11 participants. Conclusions: d-alanine intake increased plasma and urine d-alanine levels and was well tolerated in participants with normal kidney function. These results will be useful in future trials investigating the effects of d-alanine intake on kidney disease progression in patients with chronic kidney disease.This trial was registered at the UMIN Clinical Trials Registry as UMIN000051466.

Cholesterol Crystal Embolism: Autopsy-proven Gastrointestinal Lesions, Pancreatitis, and End-stage Kidney Disease Which Developed after Undergoing Selective Abdominal Angiography.

A 78-year-old man with atherosclerosis was diagnosed with hepatocellular carcinoma by transfemoral angiography of the celiac and superior mesenteric arteries (SMA). After surgery, a serum examination revealed progressive renal failure with eosinophilia, leading to end-stage kidney disease, in addition to active gastric ulcers and pancreatitis. Cyanosis in the bilateral toes showed a cholesterol crystal embolism (CCE) in a skin biopsy. Autopsy revealed that CCE involved the arterioles of multiple organs, and its distribution was anatomically consistent with the vascular territories of the celiac artery and SMA. CCE should therefore be considered in patients presenting with multiple types of tissue damage in the vascular territories after angiography.

Sex-specific associations between air pollutants and asthma prevalence in Japanese adults: a population-based study.

This study investigated the association between air pollutants and asthma prevalence in male and female Japanese adults. In this retrospective cross-sectional analysis, annual mean exposure levels of air pollutants, specifically nitrogen dioxide (NO2) and particulate matter with a median aerodynamic diameter ≤2.5 µm (PM2.5), were assessed at a local monitoring site. Multivariable logistic regression models, adjusted for genetic and/or lifestyle factors, were used to explore the association between air pollutants and asthma, with stratification by sex. A total of 1,497 participants aged ≥40 years were included. Their mean age was 65.9 ± 12.4 years, with 847 being women. Overall, 91 participants were diagnosed with asthma. In the multivariable model, ambient exposure levels of NO2 and PM2.5 were significantly associated with asthma in women but not in men. This study highlights sex as a significant determinant of the link between air pollutants and asthma exacerbation, particularly among female Japanese adults.

Prediction and causal inference of hyperuricemia using gut microbiota.

Hyperuricemia (HUA) is a symptom of high blood uric acid (UA) levels, which causes disorders such as gout and renal urinary calculus. Prolonged HUA is often associated with hypertension, atherosclerosis, diabetes mellitus, and chronic kidney disease. Studies have shown that gut microbiota (GM) affect these chronic diseases. This study aimed to determine the relationship between HUA and GM. The microbiome of 224 men and 254 women aged 40 years was analyzed through next-generation sequencing and machine learning. We obtained GM data through 16S rRNA-based sequencing of the fecal samples, finding that alpha-diversity by Shannon index was significantly low in the HUA group. Linear discriminant effect size analysis detected a high abundance of the genera Collinsella and Faecalibacterium in the HUA and non-HUA groups. Based on light gradient boosting machine learning, we propose that HUA can be predicted with high AUC using four clinical characteristics and the relative abundance of nine bacterial genera, including Collinsella and Dorea. In addition, analysis of causal relationships using a direct linear non-Gaussian acyclic model indicated a positive effect of the relative abundance of the genus Collinsella on blood UA levels. Our results suggest abundant Collinsella in the gut can increase blood UA levels.

Contributions of long-range transport from the Asian continent and local emissions on atmospheric PM2.5, polycyclic aromatic hydrocarbons, and their nitro-derivatives in Kanazawa and Noto Peninsula, Japan.

This study collected samples of particulate matter that are 2.5 µm or less in diameter (PM2.5) in Kanazawa, Japan, and Noto Peninsula located 100 km north on the windward side of the westerlies from the Asian continent and characterized the extent of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) pollution in Kanazawa. Emission areas and specific sources of PM2.5 and of PAHs and NPAHs were clarified via back-trajectory analysis and the NP-method, respectively. The results indicate that during 2020 and 2021, most PAHs (93%) in Kanazawa were transported from the Asian continent by westerlies and that the main source was coal and biomass combustion. The presence of NPAHs in Kanazawa was caused by a mixture of transport from the Asian continent (53%) and local emissions (47%), with the main source of the latter being from vehicles. Although the content of combustion-derived particulates (Pc) was <2.4% of PM2.5 in Kanazawa, this showed a similar seasonal variation (winter > summer) to that of PAHs. The contribution of Pc transported from the Asian continent exceeded that of locally emitted Pc. The current situation of Kanazawa is considerably different from that of 1997, when local vehicles were the main source of pollution.

Longitudinal relationship between screen-based sedentary behavior and nutrient intake in Japanese children: an observational epidemiological cohort study.

BACKGROUND: Concerns regarding the impact of screen-based sedentary behavior on health have been increasing. Therefore, the present study investigated the longitudinal relationship between multiple screen time and nutrient intake in children and adolescents. METHODS: The present study was conducted utilizing 3 years longitudinal data. Study subjects were 740 Japanese children aged between 6 and 12 years at baseline and between 9 and 15 years in the follow-up. Screen-based sedentary behavior was assessed using screen time, including television (TV) viewing, personal computer (PC) use, and mobile phone (MP) use. The main outcomes were the intakes of nutrients. Mixed effect multivariate linear regression analyses were used to examine the longitudinal relationship between screen-based sedentary time and nutrient intake. Covariates included in the multivariable analysis consisted of sex, age, solitary eating, skipping breakfast, staying up late, and body weight status, as confounders, and physical inactivity, as mediator. RESULTS: In boys, a longer total screen time longitudinally correlated with higher intake of energy and lower intakes of protein, dietary fiber, minerals, and vitamins. In girls, longer total screen time longitudinally associated with higher intake of sucrose and lower intakes of protein, minerals, and vitamins. In boys, a longer TV viewing time was associated with higher intake of sucrose and lower intakes of protein, minerals, and vitamins. In girls, a longer TV viewing time was associated with higher intake of carbohydrates and lower intakes of protein, fat, minerals, and vitamins. In boys, relationships were observed between a longer PC use time and higher intakes of energy as well as lower intakes of protein, minerals, and vitamins. Relationship was observed between longer PC use time and lower intakes of minerals in girls. An increased MP use time was associated with higher intakes of energy, and lower intakes of protein, sucrose, dietary fiber, minerals, and vitamins in boys. A longer MP use time was associated with higher intakes of fat, and salt as well as lower intakes of carbohydrates, protein, minerals, and vitamins in girls. CONCLUSIONS: The present results revealed that longer screen-based sedentary behaviors were longitudinally associated with nutrient intake in children and adolescents. Future study is needed to elucidate these relationships.

Association between animal protein intake, oral frailty and calf circumference in middle-aged and older adults: a cross-sectional analysis from the Shika study.

OBJECTIVE: To investigate the relationship between oral frailty (OF), nutrient intake and calf circumference (CC) in middle-aged and older adults. DESIGN: Cross-sectional study. SETTING: Residents of four model districts of Shika town, Ishikawa Prefecture, Japan, using data from November 2017 to February 2018. PARTICIPANTS: One hundred and ninety-four residents aged ≥50 years in four model districts of Shika town. The OF total score ≥3 was defined as OF. Participants were divided into OF and non-OF groups and divided into the low-CC/kg and the high-CC/kg groups. OUTCOME MEASURES: The primary outcome is to use a two-way analysis of covariance to analyse the interaction between the two CC/kg groups and the two OF groups on nutrition intake. The secondary outcome is to use multiple regression analysis to investigate the nutrients significantly related to CC/kg when stratified by OF, with age, sex, body mass index, drinking status, smoking status and regular exercise as input covariates. RESULTS: A two-way analysis of covariance revealed a significant interaction between the two CC/kg groups and the two OF groups on animal protein intake (p=0.039). Multiple comparisons using the Bonferroni analysis revealed a significantly lower animal protein intake in the OF group than in the non-OF group with a low CC/kg (p=0.033) but not in the group with a high CC/kg. The multiple regression analysis stratified by OF revealed a positive correlation between animal protein intake and CC/kg (p=0.002). CONCLUSIONS: The present results revealed a significantly lower animal protein intake in the OF group than in the non-OF group in the low-CC/kg group, but no such difference was observed in the high-CC/kg group. Further longitudinal studies are needed to elucidate this relationship.

Autoantibodies to Erythropoietin Receptor and Clinical Outcomes in Patients With Type 2 Diabetes and CKD: A Post Hoc Analysis of CREDENCE Trial.

Introduction: Autoantibodies to erythropoietin receptor (anti-EPOR antibodies) have been identified in patients with various kidney diseases. However, data in patients with type 2 diabetes (T2D) and chronic kidney disease (CKD) is limited. We assessed the prevalence of anti-EPOR antibodies and their association with clinical outcomes in this population. Methods: The CREDENCE randomized patients with T2D and CKD to canagliflozin or placebo. Serum anti-EPOR antibodies, the exposure of interest, were measured using enzyme-linked immunosorbent assay. The primary outcome was doubling of serum creatinine, end-stage kidney disease, or death from kidney or cardiovascular (CV) causes. Secondary outcomes included CV and all-cause mortality. Multivariable Cox-regression models estimated associations between anti-EPOR antibodies and outcomes. The effects of canagliflozin on hemoglobin and hematocrit, stratified by the presence of anti-EPOR antibodies were assessed with a repeated measures mixed effects model. Results: Of 2600 participants with available biosamples, 191 (7.3%) were positive for anti-EPOR antibodies. Higher baseline anti-EPOR antibodies were associated with increased risk of primary outcome (hazard ratio [HR] per 1-SD increase = 1.12, 95% confidence interval [CI] = 1.01-1.24, P = 0.04), with CV death (HR = 1.27, 95% CI = 1.08-1.48, P < 0.01) and all-cause mortality (HR = 1.26, 95% CI = 1.11-1.43, P < 0.01). During follow-up, canagliflozin, compared to placebo, increased hemoglobin and hematocrit by 7.0 g/l (95% CI = 6.2-7.9) and 2.4% (2.2-2.7), respectively. These effects were consistent across patients with and without anti-EPOR antibodies (P-interaction = 0.24 and 0.36, respectively). Conclusion: In patients with T2D and CKD, anti-EPOR antibodies were associated with the composite kidney and CV outcome, as well as CV and all-cause mortality. Canagliflozin increased hemoglobin and hematocrit regardless of anti-EPOR antibodies.

Protective Role of MAVS Signaling for Murine Lipopolysaccharide-Induced Acute Kidney Injury.

Despite treatment advances, acute kidney injury (AKI)-related mortality rates are still high in hospitalized adults, often due to sepsis. Sepsis and AKI could synergistically worsen the outcomes of critically ill patients. TLR4 signaling and mitochondrial antiviral signaling protein (MAVS) signaling are innate immune responses essential in kidney diseases, but their involvement in sepsis-associated AKI (SA-AKI) remains unclear. We studied the role of MAVS in kidney injury related to the TLR4 signaling pathway using a murine LPS-induced AKI model in wild-type and MAVS-knockout mice. We confirmed the importance of M1 macrophage in SA-AKI through in vivo assessment of inflammatory responses. The TLR4 signaling pathway was upregulated in activated bone marrow-derived macrophages, in which MAVS helped maintain the LPS-suppressed TLR4 mRNA level. MAVS regulated redox homeostasis via NADPH oxidase Nox2 and mitochondrial reverse electron transport in macrophages to alleviate the TLR4 signaling response to LPS. Hypoxia-inducible factor 1α (HIF-1α) and AP-1 were key regulators of TLR4 transcription and connected MAVS-dependent reactive oxygen species signaling with the TLR4 pathway. Inhibition of succinate dehydrogenase could partly reduce inflammation in LPS-treated bone marrow-derived macrophages without MAVS. These findings highlight the renoprotective role of MAVS in LPS-induced AKI by regulating reactive oxygen species generation-related genes and maintaining redox balance. Controlling redox homeostasis through MAVS signaling may be a promising therapy for SA-AKI.

Predictors of damage accrual in patients with antineutrophil cytoplasmic antibody-associated vasculitis: A nationwide prospective study.

OBJECTIVES: This study elucidated the prognosis and risk factors associated with damage accrual during long-term remission maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: We obtained data from 120 patients registered in a nationwide prospective cohort study on remission induction therapy in Japanese patients with AAV and rapidly progressive glomerulonephritis (RemIT-JAV-RPGN), who achieved remission at 24 months after treatment initiation and were followed up for additional 24 months. The primary outcome was the vasculitis damage index (VDI) score at Month 48, and the secondary outcome included risk factors associated with increased total VDI at Month 48. RESULTS: The understudied patients comprised 52 men and 68 women aged 68 ± 13 years. Between Months 25 and 48, the patients' survival rate was 95% (114/120). End-stage renal disease developed in seven patients by Month 48, and 64 cases had increased VDI. The multivariable analysis results revealed that oral prednisolone (PSL) doses at Month 24 were associated with damage accrual between Months 24 and 48. CONCLUSIONS: VDI accrual was observed in more than half of patients with AAV during maintenance therapy, and increased VDI scores were associated with oral PSL doses 24 months after initiating remission induction therapy in Japan.

Impact of gut microbiome on serum IgG4 levels in the general population: Shika-machi super preventive health examination results.

Introduction: Immunoglobulin G4 (IgG4) is a member of the human immunoglobulin G (IgG) subclass, a protein involved in immunity to pathogens and the body's resistance system. IgG4-related diseases (IgG4-RD) are intractable diseases in which IgG4 levels in the blood are elevated, causing inflammation in organs such as the liver, pancreas, and salivary glands. IgG4-RD are known to be more prevalent in males than in females, but the etiology remains to be elucidated. This study was conducted to investigate the relationship between gut microbiota (GM) and serum IgG4 levels in the general population. Methods: In this study, the relationship between IgG4 levels and GM evaluated in male and female groups of the general population using causal inference. The study included 191 men and 207 women aged 40 years or older from Shika-machi, Ishikawa. GM DNA was analyzed for the 16S rRNA gene sequence using next-generation sequencing. Participants were bifurcated into high and low IgG4 groups, depending on median serum IgG4 levels. Results: ANCOVA, Tukey's HSD, linear discriminant analysis effect size, least absolute shrinkage and selection operator logistic regression model, and correlation analysis revealed that Anaerostipes, Lachnospiraceae, Megasphaera, and [Eubacterium] hallii group were associated with IgG4 levels in women, while Megasphaera, [Eubacterium] hallii group, Faecalibacterium, Ruminococcus.1, and Romboutsia were associated with IgG4 levels in men. Linear non-Gaussian acyclic model indicated three genera, Megasphaera, [Eubacterium] hallii group, and Anaerostipes, and showed a presumed causal association with IgG4 levels in women. Discussion: This differential impact of the GM on IgG4 levels based on sex is a novel and intriguing finding.

Distinct associations between dietary omega-3 and omega-6 fatty acids intake with chronic kidney disease in adults with and without diabetes: A cross-sectional study.

OBJECTIVE: We explored the relationship of dietary intake of fatty acids with chronic kidney disease (CKD) according to glycemic status in Japanese people. METHODS: A total of 1031 participants aged ≥40 y were included in this population-based, cross-sectional study. A validated self-administered diet history questionnaire was used to measure the dietary intakes of fat and fatty acids, including omega-3 and omega-6 polyunsaturated fatty acids. CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2 and diabetes as the use of antidiabetic medication, fasting plasma glucose ≥ 126 mg/dL, or hemoglobin A1c of ≥6.5%. Urine biomarkers of kidney injury (liver-type fatty acid-binding protein, ß2-microglobulin, and albumin) were also examined. RESULTS: The mean age of the participants was 62.5 ± 11.2 y, and 482 (46.8%) of them were men. Overall, 177 (17.2%) participants had CKD. In the multivariable model, low omega-3 intake (odds ratio = 0.109; 95% CI, 0.019-0.645) and high omega-6-to-omega-3 ratio (odds ratio = 2.112; 95% CI, 1.167-3.822) were associated with CKD in participants with diabetes but not in those without. In selected participants with diabetes, a substantial trend of urinary liver-type fatty acid-binding protein and ß2-microglobulin level elevation along with an increase in the dietary ratio of omega-6 to omega-3 was observed. CONCLUSIONS: Low dietary omega-3 intake and high omega-6-to-omega-3 ratio were associated with CKD in middle-aged and older Japanese people with diabetes but not in those without diabetes. These results may provide insight into the more tailored approaches for dietary polyunsaturated fatty acids to prevent CKD.

A comprehensive risk factor analysis using association rules in people with diabetic kidney disease.

Association rule is a transparent machine learning method expected to share information about risks for chronic kidney disease (CKD) among diabetic patients, but its findings in clinical data are limited. We used the association rule to evaluate the risk for kidney disease in General and Worker diabetic cohorts. The absence of risk factors was examined for association with stable kidney function and worsening kidney function. A confidence value was used as an index of association, and a lift of > 1 was considered significant. Analyses were applied for individuals stratified by KDIGO's (Kidney Disease: Improving Global Outcomes) CKD risk categories. A General cohort of 4935 with a mean age of 66.7 years and a Worker cohort of 2153 with a mean age of 47.8 years were included in the analysis. Good glycemic control was significantly related to stable kidney function in low-risk categories among the General cohort, and in very-high risk categories among the Worker cohort; confidences were 0.82 and 0.77, respectively. Similar results were found with poor glycemic control and worsening kidney function; confidences of HbA1c were 0.41 and 0.27, respectively. Similarly, anemia, obesity, and hypertension showed significant relationships in the low-risk General and very-high risk Worker cohorts. Stratified risk assessment using association rules revealed the importance of the presence or absence of risk factors.

Polar vasculosis is associated with better kidney outcome in type 2 diabetes with biopsy-proven diabetic kidney disease: A multicenter cohort study.

AIMS/INTRODUCTION: This multicenter cohort study retrospectively assessed the association between polar vasculosis and the progression of diabetic kidney disease (DKD) in type 2 diabetes. MATERIALS AND METHODS: We enrolled 811 patients with type 2 diabetes, biopsy-proven DKD, and proteinuria (≥0.15 g/g creatinine [g/day]). The association between polar vasculosis and other kidney lesions was explored. The outcome was DKD progression defined as a composite of renal replacement therapy initiation or 50% decline in estimated glomerular filtration rate (eGFR) from baseline. RESULTS: Of the 811 cases, 677 (83.5%) had polar vasculosis. In multivariate logistic regression analysis, subendothelial widening of the glomerular basement membrane, glomerulomegaly, glomerular class in the Renal Pathology Society classification ≥IIb, vascular lesions, age, eGFR, and hemoglobin A1c were positively associated with polar vasculosis, whereas interstitial fibrosis and tubular atrophy (IFTA) was negatively associated with polar vasculosis. During a median follow-up of 5.2 years, progression of DKD occurred in 322 of 677 (7.4 events/100 person-years) and 79 of 134 (11.4 events/100 person-years) cases with and without polar vasculosis, respectively. Kaplan-Meier analysis showed that polar vasculosis was associated with lower cumulative incidences of DKD progression. Multivariate Cox regression analyses showed that polar vasculosis was associated with a lower risk of DKD progression, regardless of eGFR or proteinuria subgroups. These associations between polar vasculosis and better kidney outcome were unchanged considering all-cause mortality before DKD progression as a competing event. CONCLUSIONS: This study showed that polar vasculosis of DKD was associated with less advanced IFTA and a better kidney outcome in type 2 diabetes with proteinuria.

Association Between Risperidone Use and Kidney Function Decline in Patients with Schizophrenia: A Retrospective Cohort Study.

PURPOSE: Several D-amino acids have been shown to be protective against kidney injury in mice. Risperidone, a currently used atypical antipsychotic agent for schizophrenia, is also known to inhibit the activity of D-amino acid oxidase, which degrades certain D-amino acids. Based on the hypothesis that risperidone would prevent kidney disease progression, this study investigated the association between risperidone use and kidney function decline in patients with schizophrenia. METHODS: This retrospective cohort study included patients who were diagnosed with schizophrenia and had data available from two or more serum creatinine measurements between April 1, 2010, and March 31, 2020. Patients who used risperidone for at least 30 days were included in the risperidone group, whereas those who had no record of risperidone use were included in the control group. Cox regression models were used to evaluate the risk for 40% decline in estimated glomerular filtration rate (eGFR) in patients treated with risperidone compared to that in the control group. FINDINGS: Overall, 212 patients used risperidone and 1468 patients had no record of risperidone use. The mean age was 55 years, 759 (45%) of the patients were male, and the mean eGFR at baseline was 88 mL/min/1.73 m2. The mean age in the risperidone group was less than that in the control group (52 vs 56 years); other baseline characteristics were comparable between the two groups. During a mean follow-up of 1.6 years, 267 patients (16%) had a 40% eGFR decline. The incidence rate of 40% eGFR decline was lower in the risperidone group than in the control group (60 vs 104 per 1000 person-years). After adjustment for baseline age, sex, and eGFR, risperidone use was associated with a decreased risk for 40% eGFR decline (hazard ratio = 0.54; 95% CI, 0.33-0.87; P = 0.01). IMPLICATIONS: Risperidone use may be associated with decreased risk for kidney function decline in patients with schizophrenia. Further studies are warranted to validate these findings.

Impact of gut microbiome on the renin-aldosterone system: Shika-machi Super Preventive Health Examination results.

The renin-angiotensin-aldosterone system (RAAS) is a regulatory mechanism of the endocrine system and is associated with various diseases, including hypertension and renal and cardiovascular diseases. The gut microbiota (GM) have been associated with various diseases, mainly in animal models. However, to our knowledge, no studies have examined the relationship between the RAAS and GM in humans. The present study aimed to assess the association between the systemic RAAS and GM genera and their causal relationships. The study participants were 377 members of the general population aged 40 years or older in Shika-machi, Japan. Plasma renin activity (PRA), plasma aldosterone concentration (PAC), aldosterone-renin ratio (ARR), and GM composition were analyzed using the 16S rRNA method. The participants were divided into high and low groups according to the PRA, PAC, and ARR values. U-tests, one-way analysis of covariance, and linear discriminant analysis of effect size were used to identify the important bacterial genera between the two groups, and binary classification modeling using Random Forest was used to calculate the importance of the features. The results showed that Blautia, Bacteroides, Akkermansia, and Bifidobacterium were associated with the RAAS parameters. Causal inference analysis using the linear non-Gaussian acyclic model revealed a causal effect of Blautia on PAC via SBP. These results strengthen the association between the systemic RAAS and GM in humans, and interventions targeting the GM may provide new preventive measures and treatments for hypertension and renal disease.

Myocardin-related transcription factor contributes to renal fibrosis through the regulation of extracellular microenvironment surrounding fibroblasts.

Fibroblast accumulation and extracellular matrix (ECM) deposition are common critical steps for the progression of organ fibrosis, but the precise molecular mechanisms remain to be fully investigated. We have previously demonstrated that lysophosphatidic acid contributes to organ fibrosis through the production of connective tissue growth factor (CTGF) via actin cytoskeleton-dependent signaling, myocardin-related transcription factor family (MRTF) consisting of MRTF-A and MRTF-B-serum response factor (SRF) pathway. In this study, we investigated the role of the MRTF-SRF pathway in the development of renal fibrosis, focusing on the regulation of ECM-focal adhesions (FA) in renal fibroblasts. Here we showed that both MRTF-A and -B were required for the expressions of ECM-related molecules such as lysyl oxidase family members, type I procollagen and fibronectin in response to transforming growth factor (TGF)-ß1 . TGF-ß1 -MRTF-SRF pathway induced the expressions of various components of FA such as integrin α subunits (αv , α2 , α11 ) and ß subunits (ß1 , ß3 , ß5 ) as well as integrin-linked kinase (ILK). On the other hand, the blockade of ILK suppressed TGF-ß1 -induced MRTF-SRF transcriptional activity, indicating a mutual relationship between MRTF-SRF and FA. Myofibroblast differentiation along with CTGF expression was also dependent on MRTF-SRF and FA components. Finally, global MRTF-A deficient and inducible fibroblast-specific MRTF-B deficient mice (MRTF-AKO BiFBKO mice) are protected from renal fibrosis with adenine administration. Renal expressions of ECM-FA components and CTGF as well as myofibroblast accumulation were suppressed in MRTF-AKO BiFBKO mice. These results suggest that the MRTF-SRF pathway might be a therapeutic target for renal fibrosis through the regulation of components forming ECM-FA in fibroblasts.

Intra-Brain and Plasma Levels of L-Serine Are Associated with Cognitive Status in Patients with Chronic Kidney Disease.

Introduction: The number of patients with chronic kidney disease (CKD) is increasing worldwide. Cognitive impairment is one of the comorbidities of CKD. With the increased number of aged population, novel biomarkers of impaired cognitive function are required. Intra-body profile of amino acid (AA) is reportedly altered in patients with CKD. Although some AAs act as neurotransmitters in the brain, it is not clear whether altered AA profile are associated with cognitive function in patients with CKD. Therefore, intra-brain and plasma levels of AAs are evaluated with respect to cognitive function in patients with CKD. Methods: Plasma levels of AAs were compared between 14 patients with CKD, including 8 patients with diabetic kidney disease, and 12 healthy controls to identify the alteration of specific AAs in CKD. Then, these AAs were evaluated in the brains of 42 patients with brain tumor using non-tumor lesion of the resected brain. Cognitive function is analyzed with respect to intra-brain levels of AAs and kidney function. Moreover, plasma AAs were analyzed in 32 hemodialyzed patients with/without dementia. Results: In patients with CKD, plasma levels of asparagine (Asn), serine (Ser), alanine (Ala), and proline (Pro) were increased as compared to patients without CKD. Among these AAs, L-Ser, L-Ala, and D-Ser show higher levels than the other AAs in the brain. Intra-brain levels of L-Ser was correlated with cognitive function and kidney function. The number of D-amino acid oxidase or serine racemase-positive cells was not correlated with kidney function. Moreover, the plasma levels of L-Ser are also decreased in patients with declined cognitive function who are treated with chronic hemodialysis. Conclusion: The decreased levels of L-Ser are associated with impaired cognitive function in CKD patients. Especially, plasma L-Ser levels may have a potential for novel biomarker of impaired cognitive function in patients with hemodialysis.

Relationships among Depressive Symptoms, Body Weight, and Chronic Pain: A Cross-Sectional Analysis of the Shika Study.

Although depression and body weight have individually been associated with chronic pain (CP), it currently remains unclear whether the combination of depressive symptoms (DS) and being underweight/overweight is related to CP. Therefore, we herein investigated the relationships among depression, body mass index (BMI), and CP in community-dwelling middle-aged and elderly individuals. Participants comprised 2216 inhabitants of Shika town in Ishikawa prefecture, Japan, including 1003 males (mean age of 68.72 years, standard deviation (SD) of 8.36) and 1213 females (mean age of 69.65 years, SD of 9.36). CP and DS were assessed using a CP questionnaire and Geriatric Depression Scale-15, respectively. The Breslow-Day test indicated that DS positively correlated with lumbar/knee pain in the BMI < 25 group, but not in the BMI ≥ 25 group. Furthermore, lumber/knee pain was related to a higher BMI. These results were confirmed by a logistic analysis with age, sex, BMI, solitary living, the duration of education, no exercise/hobbies, smoking history, alcohol intake, and medical treatment for diabetes, hyperlipidemia, or hypertension as confounding factors. The present study indicates the importance of considering DS and BMI in the prevention of CP. Further studies are needed to clarify the causal relationships among depression, BMI, and CP.