Sodium-glucose co-transporter protein 2 (SGLT2) inhibitors for people with chronic kidney disease and diabetes

BACKGROUND

Diabetes is associated with high risks of premature chronic kidney disease (CKD), cardiovascular diseases, cardiovascular death and impaired quality of life. People with diabetes are more likely to develop kidney impairment, and approximately one in three adults with diabetes have CKD. People with CKD and diabetes experience a substantially higher risk of cardiovascular outcomes. Sodium-glucose co-transporter protein 2 (SGLT2) inhibitors have shown potential effects in preventing kidney and cardiovascular outcomes in people with CKD and diabetes. However, new trials are emerging rapidly, and evidence synthesis is essential to summarising cumulative evidence.

OBJECTIVES

This review aimed to assess the benefits and harms of SGLT2 inhibitors for people with CKD and diabetes.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 17 November 2023 using a search strategy designed by an Information Specialist. Studies in the Register are continually identified through regular searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled studies were eligible if they evaluated SGLT2 inhibitors versus placebo, standard care or other glucose-lowering agents in people with CKD and diabetes. CKD includes all stages (from 1 to 5), including dialysis patients.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed the study risk of bias. Treatment estimates were summarised using random effects meta-analysis and expressed as a risk ratio (RR) or mean difference (MD), with a corresponding 95% confidence interval (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The primary review outcomes were all-cause death, 3-point and 4-point major adverse cardiovascular events (MACE), fatal or nonfatal myocardial infarction (MI), fatal or nonfatal stroke, and kidney failure.

MAIN RESULTS

Fifty-three studies randomising 65,241 people with CKD and diabetes were included. SGLT2 inhibitors with or without other background treatments were compared to placebo, standard care, sulfonylurea, dipeptidyl peptidase-4 (DPP-4) inhibitors, or insulin. In the majority of domains, the risks of bias in the included studies were low or unclear. No studies evaluated the treatment in children or in people treated with dialysis. No studies compared SGLT2 inhibitors with glucagon-like peptide-1 receptor agonists or tirzepatide. Compared to placebo, SGLT2 inhibitors decreased the risk of all-cause death (20 studies, 44,397 participants: RR 0.85, 95% CI 0.78 to 0.94; I2 = 0%; high certainty) and cardiovascular death (16 studies, 43,792 participants: RR 0.83, 95% CI 0.74 to 0.93; I2 = 29%; high certainty). Compared to placebo, SGLT2 inhibitors probably make little or no difference to the risk of fatal or nonfatal MI (2 studies, 13,726 participants: RR 0.95, 95% CI 0.80 to 1.14; I2 = 24%; moderate certainty), and fatal or nonfatal stroke (2 studies, 13,726 participants: RR 1.07, 95% CI 0.88 to 1.30; I2 = 0%; moderate certainty). Compared to placebo, SGLT2 inhibitors probably decrease 3-point MACE (7 studies, 38,320 participants: RR 0.89, 95% CI 0.81 to 0.98; I2 = 46%; moderate certainty), and 4-point MACE (4 studies, 23,539 participants: RR 0.82, 95% CI 0.70 to 0.96; I2 = 77%; moderate certainty), and decrease hospital admission due to heart failure (6 studies, 28,339 participants: RR 0.70, 95% CI 0.62 to 0.79; I2 = 17%; high certainty). Compared to placebo, SGLT2 inhibitors may decrease creatinine clearance (1 study, 132 participants: MD -2.63 mL/min, 95% CI -5.19 to -0.07; low certainty) and probably decrease the doubling of serum creatinine (2 studies, 12,647 participants: RR 0.70, 95% CI 0.56 to 0.89; I2 = 53%; moderate certainty). SGLT2 inhibitors decrease the risk of kidney failure (6 studies, 11,232 participants: RR 0.70, 95% CI 0.62 to 0.79; I2 = 0%; high certainty), and kidney composite outcomes (generally reported as kidney failure, kidney death with or without ≥ 40% decrease in estimated glomerular filtration rate (eGFR)) (7 studies, 36,380 participants: RR 0.68, 95% CI 0.59 to 0.78; I2 = 25%; high certainty) compared to placebo. Compared to placebo, SGLT2 inhibitors incur less hypoglycaemia (16 studies, 28,322 participants: RR 0.93, 95% CI 0.89 to 0.98; I2 = 0%; high certainty), and hypoglycaemia requiring third-party assistance (14 studies, 26,478 participants: RR 0.75, 95% CI 0.65 to 0.88; I2 = 0%; high certainty), and probably decrease the withdrawal from treatment due to adverse events (15 studies, 16,622 participants: RR 0.94, 95% CI 0.82 to 1.08; I2 = 16%; moderate certainty). The effects of SGLT2 inhibitors on eGFR, amputation and fracture were uncertain. No studies evaluated the effects of treatment on fatigue, life participation, or lactic acidosis. The effects of SGLT2 inhibitors compared to standard care alone, sulfonylurea, DPP-4 inhibitors, or insulin were uncertain.

AUTHORS' CONCLUSIONS

SGLT2 inhibitors alone or added to standard care decrease all-cause death, cardiovascular death, and kidney failure and probably decrease major cardiovascular events while incurring less hypoglycaemia compared to placebo in people with CKD and diabetes.

Histological and immunohistochemical analyses of articular cartilage during onset and progression of pre- and early-stage osteoarthritis in a rodent model

Early diagnosis and treatment of pre- and early-stage osteoarthritis (OA) is important. However, the cellular and cartilaginous changes occurring during these stages remain unclear. We investigated the histological and immunohistochemical changes over time between pre- and early-stage OA in a rat model of traumatic injury. Thirty-six male rats were divided into two groups, control and OA groups, based on destabilization of the medial meniscus. Histological and immunohistochemical analyses of articular cartilage were performed on days 1, 3, 7, 10, and 14 postoperatively. Cell density of proteins associated with cartilage degradation increased from postoperative day one. On postoperative day three, histological changes, including chondrocyte death, reduced matrix staining, and superficial fibrillation, were observed. Simultaneously, a compensatory increase in matrix staining was observed. The Osteoarthritis Research Society International score increased from postoperative day seven, indicating thinner cartilage. On postoperative day 10, the positive cell density decreased, whereas histological changes progressed with fissuring and matrix loss. The proteoglycan 4-positive cell density increased on postoperative day seven. These findings will help establish an experimental model and clarify the mechanism of the onset and progression of pre- and early-stage traumatic OA.

Design and rationale for an open-label, randomized, controlled pilot trial to evaluate the changes in blood uremic toxins in patients with chronic kidney disease by dietary therapy with sake lees

BACKGROUND

Patients with chronic kidney disease (CKD) reportedly show dysbiosis, which is the imbalance of gut microbiome. Dysbiosis increases the uremic toxin level in the intestine, and uremic toxins transfer into the blood, causing CKD progression. Sake lees, a traditional Japanese fermented food, may help reduce uremic toxins by altering the gut microbiome. Additionally, D-alanine, which is present in sake lees, may have a renoprotective effect. The present pilot study aims to evaluate the effect of adding sake lees to the standard CKD dietary therapy in reducing blood uremic toxins.

METHODS

This pilot study is a single-center, open-label, randomized controlled trial. Twenty-four patients with CKD will be enrolled and allocated 1:1 to the intervention and control groups. The intervention group will receive standard CKD dietary therapy with an additional intake of 50 g of sake lees per day for 8 weeks, whereas the control group will only receive standard CKD dietary therapy. The primary endpoint is the change in serum indoxyl sulfate after 8 weeks. The secondary endpoint is the plasma D-alanine and fecal microbiome changes.

CONCLUSION

This pilot study provides insight into the development of a new diet focused on gut microbiome and D-amino acids in patients with CKD.

CLINICAL TRIAL REGISTRATION

This protocol was approved by the Clinical Trial Review Board of Kanazawa University Hospital on October 27, 2022 (2022-001 [6139]) and available to the public on the website of the Japan Registry of Clinical Trials on November 22, 2022 (jRCT1040220095).

Clinical impacts of positive intraepithelial neoplasia at pancreatic transection margin in pancreatic cancer surgery

BACKGROUND/OBJECTIVES

The outcomes of patients with intraepithelial neoplasia at the pancreatic transection margin after pancreatic cancer surgery remain unclear. We evaluated the clinical impact of pancreatic transection margin status.

METHODS

This retrospective observational study included 171 patients who underwent surgery for pancreatic ductal adenocarcinoma between January 2008 and December 2019. Patients were classified into three groups: negative pancreatic transection margin (group N), positive low-grade (group L), and positive high-grade (group H) intraepithelial neoplasia. The clinicopathological findings and prognoses were analyzed for each group.

RESULTS

There were 140, 14, and 9 patients in groups N, L, and H, respectively. The median age was significantly higher in group H (p = 0.035). There were no significant differences in male ratio, preoperative chemotherapy administration rate, pretreatment tumor markers, operative procedure, operative time, or blood loss. Overall survival and recurrence-free survival were not significantly different; however, the cumulative risk of recurrence in the remnant pancreas was significantly higher in group H (p = 0.018).

CONCLUSIONS

Intraepithelial neoplasia at the pancreatic transection margin did not affect overall/recurrence-free survival. As patients with high-grade intraepithelial neoplasia at the pancreatic transection margin have an increased risk of recurrence in the remnant pancreas, careful postoperative follow-up is required.

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.

Importance of History Taking and Physical Examination Before Rapid Laboratory Test for Seasonal Influenza Virus: A Single-Center Multiple Logistic Analysis

Background Despite several rapid influenza diagnostic tests (RIDTs), they are predicting whether a patient has influenza before rapid testing is important. Here, we assessed factors predictive of a positive flu test via RIDTs by combining interviews and physical examination. Methods We analyzed the relationship between interviews and physical findings and results of RIDTs using multivariable logistic regression. Results Two hundred seventy-six children were enrolled throughout the 2018-2019 flu season. Accordingly, 115 patients (41.7%) were positive for flu A. Our logistic regression model identified age, body temperature, and the existence of upper respiratory symptoms as significant factors for predicting positive for RIDTs, with odds ratios (OR) of 1.17 [95% CI (confidence interval): 1.08-1.25]/+Δ1year old, 1.70 (95% CI: 1.27-2.27)/+Δ1 ℃, and 5.08 (95% CI: 2.57-10.00) for respiratory symptoms. In addition, the OR for sick contact was 7.67 (95% CI: 3.96-14.90). Our logistic regression model showed an area under the curve (AUC) of 0.84. History of vaccination was not identified as a significant factor in positive RIDTs. Conclusions The existence of sick contact was associated with a positive flu test via RIDTs. Although RIDTs are an easy and quick method for detecting the flu virus, we should perform the appropriate identification of cases for RIDTs by combining interviews and physical findings.

Novel Utility of Leucine-Rich Alpha-2-Glycoprotein as a Biomarker in Ulcerative Colitis: A Predictor of Endoscopic Remission Independent of Symptoms

Introduction

Leucine-rich alpha-2-glycoprotein (LRG) is a potential biomarker for disease activity and reflects mucosal healing in patients with ulcerative colitis (UC). However, only a few studies have described a detailed sensitivity analysis of LRG in predicting mucosal healing in patients. This study aimed to evaluate the association between LRG and the endoscopic activity of UC and its predictability for mucosal healing and explore the utility and clinical application of LRG.

Methods

The diagnostic accuracy of biomarkers, including LRG, in predicting the endoscopic activity of UC was evaluated. All consecutive patients who underwent total colonoscopy between April 2021 and September 2022 were included. The Mayo endoscopic subscore (MES) was used for assessing endoscopic activity. Furthermore, endoscopic remission was defined as an MES of ≤1. Clinical activity was evaluated based on stool frequency and bloody stool. Receiver operating characteristic curve analysis and binary logistic regression were performed to assess the diagnostic accuracy of the biomarkers. We evaluated LRG trends and treatment response in patients with MES ≥2 who underwent induction therapy.

Results

This study comprised 214 patients. The proportions of endoscopically and clinically active patients were 33.6% and 49.1%, respectively. LRG had an area under the curve (AUC) of 0.856, with a higher diagnostic accuracy than other biomarkers, such as C-reactive protein, leukocyte, neutrophil, platelet, and albumin. The cutoff value for LRG was 15.6 μg/mL (sensitivity, 72.2%; specificity, 86.6%). Using the MES, patients with higher scores had higher LRG levels than those with lower scores. The cutoff value, AUC, sensitivity, and specificity varied with a higher AUC for left-sided colitis and pancolitis than for proctitis. Logistic regression analysis showed that LRG was an independent predictor of endoscopic remission using multivariate analysis, even with the factor of clinical activity. The change ratio of LRG pre- and post-treatment was statistically significant in the higher LRG group.

Conclusion

LRG reflected endoscopic activity independently, regardless of clinical symptoms. An LRG below the cutoff value could indicate a significantly low probability of endoscopic activity in asymptomatic patients, and follow-up endoscopy (not for cancer screening) may be unnecessary. Furthermore, a higher LRG level might be more useful as an indicator of treatment efficacy.

Association between switching prescribed drugs for lower urinary tract symptoms and independence of urination in post-stroke patients: A retrospective cohort study

OBJECTIVES

Stroke patients frequently exhibit loss of independence of urination, and their lower urinary tract symptoms change with the phase of stroke. However, it is unclear whether switching prescribed drugs for lower urinary tract symptoms during hospitalization from acute care wards to convalescence rehabilitation wards affects patients' independence of urination at discharge. It is also unclear whether the impact of switching varies by stroke type. This retrospective cohort study aimed to examine these issues.

MATERIALS AND METHODS

We analyzed 990 patients registered in the Kaga Regional Cooperation Clinical Pathway for Stroke database during 2015-2019. Prescriptions for lower urinary tract symptoms from pre-onset to convalescence rehabilitation were surveyed. Logistic regression analysis was performed to examine the association between switching drugs and independence of urination based on bladder management and voiding location at discharge. Stroke types were also examined in subgroup analyses.

RESULTS

About 21 % of patients had their lower urinary tract symptoms prescriptions switched during hospitalization. Switching was positively associated with independence of bladder management (odds ratio 1.65, 95 % confidence interval 1.07 to 2.49) and voiding location (odds ratio 2.72, 95 % confidence interval 1.72 to 4.37). Similar associations were observed in different stroke types.

CONCLUSIONS

Approximately 20 % of patients had their lower urinary tract symptoms medications switched upon transfer from acute to convalescence rehabilitation wards. Switching was significantly associated with improved urinary independence at discharge. Consistent results were observed across different stroke types, suggesting that switching medications contributes to urinary independence after stroke, regardless of the etiology or severity of stroke.

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.

Necessity of pharyngeal anesthesia during transoral gastrointestinal endoscopy: a randomized clinical trial

BACKGROUND/AIMS

The necessity for pharyngeal anesthesia during upper gastrointestinal endoscopy is controversial. This study aimed to compare the observation ability with and without pharyngeal anesthesia under midazolam sedation.

METHODS

This prospective, single-blinded, randomized study included 500 patients who underwent transoral upper gastrointestinal endoscopy under intravenous midazolam sedation. Patients were randomly allocated to pharyngeal anesthesia: PA+ or PA- groups (250 patients/group). The endoscopists obtained 10 images of the oropharynx and hypopharynx. The primary outcome was the non-inferiority of the PA- group in terms of the pharyngeal observation success rate.

RESULTS

The pharyngeal observation success rates in the pharyngeal anesthesia with and without (PA+ and PA-) groups were 84.0% and 72.0%, respectively. The PA- group was inferior (p=0.707, non-inferiority) to the PA+ group in terms of observable parts (8.33 vs. 8.86, p=0.006), time (67.2 vs. 58.2 seconds, p=0.001), and pain (1.21±2.37 vs. 0.68±1.78, p=0.004, 0-10 point visual analog scale). Suitable quality images of the posterior wall of the oropharynx, vocal fold, and pyriform sinus were inferior in the PA- group. Subgroup analysis showed a higher sedation level (Ramsay score ≥5) with almost no differences in the pharyngeal observation success rate between the groups.

CONCLUSION

Non-pharyngeal anesthesia showed no non-inferiority in pharyngeal observation ability. Pharyngeal anesthesia may improve pharyngeal observation ability in the hypopharynx and reduce pain. However, deeper anesthesia may reduce this difference.

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.

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)-β1 . TGF-β1 -MRTF-SRF pathway induced the expressions of various components of FA such as integrin α subunits (αv , α2 , α11 ) and β subunits (β1 , β3 , β5 ) as well as integrin-linked kinase (ILK). On the other hand, the blockade of ILK suppressed TGF-β1 -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.

Development of performance indicators for hepatitis countermeasures as a tool for the assessment and promotion of liver cancer prevention in Japan

BACKGROUND

Hepatitis countermeasures are being promoted by governments in Japan. We aimed to develop performance indicators (PIs) to assess the process and outcome of such countermeasures implemented for the prevention of viral hepatitis-related liver cancer at the national and prefectural government levels.

METHODS

We developed 19 PIs for hepatitis countermeasures implemented by local governments, covering the morbidity and mortality of liver cancer, hepatitis testing, subsidy programs for examinations and antiviral treatment, and education on hepatitis patient care to healthcare workers. We analyzed the PIs for each prefecture from Fiscal Year (FY) 2018-2020.

RESULTS

The morbidity and mortality of liver cancer significantly decreased in the study period. The percentage of municipalities conducting hepatitis screening was already high at 95% in FY2017. The usage rate of government-subsidized screenings did not change. The subsidy usage rate for periodic viral hepatitis examination significantly increased. Meanwhile, the subsidy usage rate for antiviral treatment of hepatitis B increased, whereas that for hepatitis C decreased. The number of certified healthcare workers providing care for hepatitis patients increased significantly, and these workers were efficiently placed at regional core centers, institutions specialized in liver diseases, health care centers, and municipal governments. Liver cancer mortality was positively correlated with hepatitis screening, subsidies for periodic examinations, and the number of hepatitis medical care coordinators but was negatively correlated with subsidies for anti-HCV therapy, suggesting that rigorous countermeasures were implemented in prefectures with high liver cancer mortality.

CONCLUSIONS

The developed PIs could be a useful tool for monitoring government efforts and achievements, thereby providing basic data for setting practical goals in liver cancer prevention.

Sex differences in risk factors for end-stage kidney disease and death in type 2 diabetes: A retrospective cohort study

BACKGROUND

This study investigated the sex differences in the risk of end-stage kidney disease (ESKD) and mortality, as well as the effect modification of sex on associated factors in patients with type 2 diabetes.

METHODS

This multicenter observational cohort study included 4328 patients with type 2 diabetes. Hazard ratios (HRs) with 95% confidence intervals (CIs) of sex for ESKD and death were estimated using Cox proportional regression with adjustment for baseline covariates. For assessing risk modification, HRs and incidence rates for ESKD and death were compared between sexes across patient characteristics using Cox proportional and Poisson regression models.

RESULTS

During a median follow-up of 7 years, 276 patients (70% men) developed ESKD, and 241 patients (68% men) died. Men had higher risks of ESKD (HR 1.34; 95% CI 1.02-1.75; p = .034) and death (HR 1.64; 95% CI 1.24-2.16; p = .001) versus women after adjusting for multiple covariates. Among patients with microalbuminuria, men had a substantially higher risk of ESKD versus women, compared to those with normo- and macroalbuminuria (p for interaction .04). Incidence rates were also increased in men versus women with albuminuria of around 300 mg/g. No differences were detected in the association of sex and death across baseline patient subgroups.

CONCLUSIONS

In type 2 diabetes, men had an increased risk of ESKD and death versus women. Moderately increased albuminuria was strongly associated with sex difference in developing ESKD.

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

<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusion:</i></b> 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.

Increased levels of oral Streptococcus-derived D-alanine in patients with chronic kidney disease and diabetes mellitus

The number of patients on hemodialysis is increasing globally; diabetes mellitus (DM) complications is the major cause of hemodialysis in patients with chronic kidney disease (CKD). The D-amino acid (AA) profile is altered in patients with CKD; however, it has not been studied in patients with CKD and DM. Furthermore, bacteria responsible for altering the D-AA profile are not well understood. Therefore, we examined the D-AA profiles and associated bacteria in patients with CKD, with and without DM. We enrolled 12 healthy controls and 54 patients with CKD, with and without DM, and determined their salivary, stool, plasma, and urine chiral AA levels using two-dimensional high-performance liquid chromatography. We performed 16S rRNA gene sequencing analysis of the oral and gut microbiota to determine the association between the abundance of bacterial species and D-AA levels. Plasma D-alanine and D-serine levels were higher in patients with CKD than in healthy adults (p < 0.01), and plasma D-alanine levels were higher in patients with CKD and DM than in those without DM. The abundance of salivary Streptococcus, which produced D-alanine, increased in patients with CKD and DM and was positively correlated with plasma D-alanine levels. Patients with CKD and DM had unique oral microbiota and D-alanine profiles. Plasma D-alanine is a potential biomarker for patients with CKD and DM.

Effect of Low-Density Lipoprotein Apheresis on Quality of Life in Patients with Diabetes, Proteinuria, and Hypercholesterolemia

<b><i>Introduction:</i></b> Treating diabetic nephropathy with low-density lipoprotein (LDL) apheresis reduces proteinuria and improves prognosis. However, its impact on patients’ quality of life (QoL) is unclear. This study evaluated the effect of LDL apheresis on QoL in patients with diabetes, proteinuria, and hypercholesterolemia. <b><i>Methods:</i></b> In this nationwide multicenter prospective study, we enrolled 40 patients with diabetes. Inclusion criteria were proteinuria (defined as an albumin/creatinine ratio ≥3 g/g), serum creatinine levels &#x3c;2 mg/dL, and serum LDL ≥120 mg/dL despite drug treatment. LDL apheresis was performed 6–12 times within 12 weeks. The 36-item Short Form Health Survey (SF-36) was used to analyze QoL. <b><i>Results:</i></b> The study enrolled 35 patients (27 men and 8 women; mean age 58.9 ± 11.9 years). A comparison of baseline SF-36 values with those at the end of the course of apheresis found an improvement in the mean physical component summary (37.9 ± 11.4 vs. 40.6 ± 10.5, <i>p</i> = 0.051) and a significant increase in the mean mental component summary (MCS) (49.4 ± 8.4 vs. 52.5 ± 10.9, <i>p</i> = 0.026). A multivariable linear regression analysis revealed a history of coronary heart disease negatively correlated with the MCS increase at the end of the course of apheresis (<i>β</i> coefficient −6.935, 95% confidence interval, 13.313 to−0.556, <i>p</i> = 0.034). <b><i>Conclusion:</i></b> Our results suggest that LDL apheresis may improve the mental and physical QoL in patients with diabetes, proteinuria, and hypercholesterolemia.

Efficacy of a novel self-expandable metal stent with dumbbell-shaped flare ends for distal biliary obstruction due to unresectable pancreatic cancer

This study aimed to evaluate the efficacy of a novel fully covered self-expandable metal stent (SEMS) with dumbbell-shaped flare ends for the palliation of distal biliary obstruction (DBO) due to unresectable pancreatic cancer (UPC). Patients with DBO due to UPC who received the novel HILZO fully covered stent (HFS), the WALLFLEX partially covered stent (WPS) or fully covered stent (WFS) were analyzed. The incidence of recurrent biliary obstruction (RBO), time to RBO (TRBO), and the incidence of complications were compared among the three SEMS groups. Eighty-four patients (HFS, n = 36; WPS, n = 20; WFS, n = 28) were included. The incidence of RBO was low in the HFS group (versus the WPS and WFS group, p = 0.033 and 0.023, respectively). TRBO in the HFS group was longer than that in the WFS group (p = 0.049). Placement of the HFS was an independent factor for long TRBO in multivariable analysis (p = 0.040). The incidence of pancreatitis and cholecystitis in the HFS group was low (one for each). It is recommended to use the HFS for the palliation of DBO due to UPC from the viewpoint of the low incidence of RBO and complications.

Kif26b contributes to the progression of interstitial fibrosis via migration and myofibroblast differentiation in renal fibroblast

Kinesin family member 26b (Kif26b) is essential for kidney development, and its deletion in mice leads to kidney agenesis. However, the roles of this gene in adult settings remain elusive. Thus, this study aims to investigate the role of Kif26b in the progression of renal fibrosis. A renal fibrosis model with adenine administration using Kif26b heterozygous mice and wild-type mice was established. Renal fibrosis and the underlying mechanism were investigated. The underlying pathways and functions of Kif26b were evaluated in an in vitro model using primary renal fibroblasts. Kif26b heterozygous mice were protected from renal fibrosis with adenine administration. Renal expressions of connective tissue growth factor (CTGF) and myofibroblast accumulation were reduced in Kif26b heterozygous mice. The expression of nonmuscle myosin heavy chain II (NMHCII), which binds to the C-terminus of Kif26b protein, was also suppressed in Kif26b heterozygous mice. The in vitro study revealed reduced expressions of CTGF, α-smooth muscle actin, and myosin heavy chain 9 (Myh9) via transfection with siRNAs targeting Kif26b in renal fibroblasts (RFB). RFBs, which were transfected by the expression vector of Kif26b, demonstrated higher expressions of these genes than non-transfected cells. Finally, Kif26b suppression and NMHCII blockage led to reduced abilities of migration and collagen gel contraction in renal fibroblasts. Taken together, Kif26b contributes to the progression of interstitial fibrosis via migration and myofibroblast differentiation through Myh9 in the renal fibrosis model. Blockage of this pathway at appropriate timing might be a therapeutic approach for renal fibrosis.

Modeling Low Muscle Mass Screening in Hemodialysis Patients

<b><i>Introduction:</i></b> Computed tomography (CT) can accurately measure muscle mass, which is necessary for diagnosing sarcopenia, even in dialysis patients. However, CT-based screening for such patients is challenging, especially considering the availability of equipment within dialysis facilities. We therefore aimed to develop a bedside prediction model for low muscle mass, defined by the psoas muscle mass index (PMI) from CT measurement. <b><i>Methods:</i></b> Hemodialysis patients (<i>n</i> = 619) who had undergone abdominal CT screening were divided into the development (<i>n</i> = 441) and validation (<i>n</i> = 178) groups. PMI was manually measured using abdominal CT images to diagnose low muscle mass by two independent investigators. The development group’s data were used to create a logistic regression model using 42 items extracted from clinical information as predictive variables; variables were selected using the stepwise method. External validity was examined using the validation group’s data, and the area under the curve (AUC), sensitivity, and specificity were calculated. <b><i>Results:</i></b> Of all subjects, 226 (37%) were diagnosed with low muscle mass using PMI. A predictive model for low muscle mass was calculated using ten variables: each grip strength, sex, height, dry weight, primary cause of end-stage renal disease, diastolic blood pressure at start of session, pre-dialysis potassium and albumin level, and dialysis water removal in a session. The development group’s adjusted AUC, sensitivity, and specificity were 0.81, 60%, and 87%, respectively. The validation group’s adjusted AUC, sensitivity, and specificity were 0.73, 64%, and 82%, respectively. <b><i>Discussion/Conclusion:</i></b> Our results facilitate skeletal muscle screening in hemodialysis patients, assisting in sarcopenia prophylaxis and intervention decisions.

Isolation of Aquatic Plant Growth-Promoting Bacteria for the Floating Plant Duckweed (Lemna minor)

Plant growth-promoting bacteria (PGPB) can exert beneficial growth effects on their host plants. Little is known about the phylogeny and growth-promoting mechanisms of PGPB associated with aquatic plants, although those of terrestrial PGPB have been well-studied. Here, we report four novel aquatic PGPB strains, MRB1–4 (NITE P-01645–P-01648), for duckweed Lemna minor from our rhizobacterial collection isolated from Lythrum anceps. The number of L. minor fronds during 14 days co-culture with the strains MRB1–4 increased by 2.1–3.8-fold, compared with an uninoculated control; the plant biomass and chlorophyll content in co-cultures also increased. Moreover, all strains possessed an indole-3-acetic acid production trait in common with a plant growth-promoting trait of terrestrial PGPB. Phylogenetic analysis showed that three strains, MRB-1, -3, and -4, were affiliated with known proteobacterial genera (Bradyrhizobium and Pelomonas); this report is the first to describe a plant-growth promoting activity of Pelomonas members. The gammaproteobacterial strain MRB2 was suggested to be phylogenetically novel at the genus level. Under microscopic observation, the Pelomonas strain MRB3 was epiphytic and adhered to both the root surfaces and fronds of duckweed. The duckweed PGPB obtained here could serve as a new model for understanding unforeseen mechanisms behind aquatic plant-microbe interactions.

Sodium-Glucose Cotransporter 2 Inhibitors and Risk of Hyperkalemia in People With Type 2 Diabetes: A Meta-Analysis of Individual Participant Data From Randomized, Controlled Trials

BACKGROUND

Hyperkalemia increases risk of cardiac arrhythmias and death and limits the use of renin-angiotensin-aldosterone system inhibitors and mineralocorticoid receptor antagonists, which improve clinical outcomes in people with chronic kidney disease or systolic heart failure. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of cardiorenal events in people with type 2 diabetes at high cardiovascular risk or with chronic kidney disease. However, their effect on hyperkalemia has not been systematically evaluated.

METHODS

A meta-analysis was conducted using individual participant data from randomized, double-blind, placebo-controlled clinical outcome trials with SGLT2 inhibitors in people with type 2 diabetes at high cardiovascular risk or with chronic kidney disease in whom serum potassium levels were routinely measured. The primary outcome was time to serious hyperkalemia, defined as central laboratory-determined serum potassium ≥6.0 mmol/L, with other outcomes including investigator-reported hyperkalemia events and hypokalemia (serum potassium ≤3.5 mmol/L). Cox regression analyses were performed to estimate treatment effects from each trial with hazards ratios and corresponding 95% CIs pooled with random-effects models to obtain summary treatment effects, overall and across key subgroups.

RESULTS

Results from 6 trials were included comprising 49 875 participants assessing 4 SGLT2 inhibitors. Of these, 1754 participants developed serious hyperkalemia, and an additional 1119 investigator-reported hyperkalemia events were recorded. SGLT2 inhibitors reduced the risk of serious hyperkalemia (hazard ratio, 0.84 [95% CI, 0.76-0.93]), an effect consistent across studies (P_{heterogeneity}=0.71). The incidence of investigator-reported hyperkalemia was also lower with SGLT2 inhibitors (hazard ratio, 0.80 [95% CI, 0.68-0.93]; P_{heterogeneity}=0.21). Reductions in serious hyperkalemia were observed across a range of subgroups, including baseline kidney function, history of heart failure, and use of renin-angiotensin-aldosterone system inhibitor, diuretic, and mineralocorticoid receptor antagonist. SGLT2 inhibitors did not increase the risk of hypokalemia (hazard ratio, 1.04 [95% CI, 0.94-1.15]; P_{heterogeneity}=0.42).

CONCLUSIONS

SGLT2 inhibitors reduce the risk of serious hyperkalemia in people with type 2 diabetes at high cardiovascular risk or with chronic kidney disease without increasing the risk of hypokalemia.

Cyclin-dependent kinase 4-related tubular epithelial cell proliferation is regulated by Paired box gene 2 in kidney ischemia-reperfusion injury

Paired box 2 (Pax2) is a transcription factor essential for kidney development and is reactivated in proximal tubular epithelial cells (PTECs) during recovery from kidney injury. However, the role of Pax2 in this process is still unknown. Here the role of Pax2 reactivation during injury was examined in the proliferation of PTECs using an ischemia-reperfusion injury (IRI) mouse model. Kidney proximal tubule-specific Pax2 conditional knockout mice were generated by mating kidney androgen-regulated protein-Cre and Pax2 flox mice. The degree of cell proliferation and fibrosis was assessed and a Pax2 inhibitor (EG1) was used to evaluate the role of Pax2 in the hypoxic condition of cultured PTECs (O₂ 5%, 24 hours). The number of Pax2-positive cells and Pax2 mRNA increased after IRI. Sirius red staining indicated that the area of interstitial fibrosis was significantly larger in knockout mice 14 days after IRI. The number of Ki-67-positive cells (an index of proliferation) was significantly lower in knockout than in wild-type mice after IRI, whereas the number of TUNEL-positive cells (an index of apoptotic cells) was significantly higher in knockout mice four days after IRI. Expression analyses of cell cycle-related genes showed that cyclin-dependent kinase 4 (CDK4) was significantly less expressed in the Pax2 knockout mice. In vitro data showed that the increase in CDK4 mRNA and protein expression induced by hypoxia was attenuated by EG1. Thus, Pax2 reactivation may be involved in PTEC proliferation by activating CDK4, thereby limiting kidney fibrosis.

Protective Effect of D-Alanine Against Acute Kidney Injury

BACKGROUND

Recent studies revealed the connection between amino acid chirality and diseases. We previously reported that the gut microbiota produced various D-amino acids in a murine acute kidney injury (AKI) model. Here, we further explore the pathophysiological role of D-Alanine (Ala) in AKI.

METHODS

We analyzed the transcripts of the N-methyl-D-aspartate (NMDA) receptor, a receptor for D-Ala, in tubular epithelial cells (TECs). Then, the therapeutic effect of D-Ala was assessed in vivo and in vitro. Lastly, the plasma level of D-Ala was evaluated in AKI patients.

RESULTS

The Grin genes encoding NMDA receptor subtypes were expressed in TECs. Hypoxia condition changes the gene expressions of Grin1, Grin2A and Grin2B. D-Ala protected TECs from hypoxia-related cell injury and induced proliferation after hypoxia. These protective effects are associated with the chirality of D-Ala. D-Ala inhibits ROS production and improves mitochondrial membrane potential, through NMDA receptor signaling. The ratio of D-Ala/L-Ala was increased in feces, plasma, and urine after the induction of I/R. Moreover, enterobacteriaceae, such as Escherichia coli, Klebsiella oxytoca produced D-Ala. The oral administration of D-Ala ameliorated kidney injury after I/R induction in mice. The deficiency of NMDA subunit NR1 on tubular cell worsened kidney damage in AKI. In addition, the plasma level of D-Ala was increased and reflected the level of renal function in AKI patients.

CONCLUSIONS

D-Ala has protective effects on I/R-induced kidney injury. Moreover, the plasma level of D-Ala reflects the eGFR in AKI patients. D-Ala could be a promising therapeutic target and potential biomarker for AKI.

Repeated Necrotizing Lymphadenitis with MEFV Gene Mutations

We herein report a 36-year-old man with repeated necrotizing lymphadenitis due to MEFV gene mutations. The patient's chief complaints were a fever and painful cervical lymphadenopathy. We diagnosed him with necrotizing lymphadenitis based on the pathological findings of the lymph nodes and the exclusion of other differential diseases. The same episode recurred four times. We speculated the involvement of autoinflammatory backgrounds and detected MEFV gene mutations of E148Q (homo), P369S, and R408Q. Considering the elevation of interleukin-18, these mutations probably played roles in the repeated necrotizing lymphadenitis.

Intestinal Bacterial Translocation Contributes to Diabetic Kidney Disease

Background In recent years, many studies have focused on the intestinal environment to elucidate pathogenesis of various diseases, including kidney diseases. Impairment of the intestinal barrier function, the "leaky gut," reportedly contributes to pathological processes in some disorders. Mitochondrial antiviral signaling protein (MAVS), a component of innate immunity, maintains intestinal integrity. The effects of disrupted intestinal homeostasis associated with MAVS signaling in diabetic kidney disease remains unclear. Methods To evaluate the contribution of intestinal barrier impairment to kidney injury under diabetic conditions, we induced diabetic kidney disease in wild-type and MAVS knockout mice through unilateral nephrectomy and streptozotocin treatment. We then assessed effects on the kidney, intestinal injuries, and bacterial translocation. Results MAVS knockout diabetic mice showed more severe glomerular and tubular injuries compared with wild-type diabetic mice. Owing to impaired intestinal integrity, the presence of intestine-derived Klebsiella oxytoca and elevated IL-17 were detected in the circulation and kidneys of diabetic mice, especially in diabetic MAVS knockout mice. Stimulation of tubular epithelial cells with K. oxytoca activated MAVS pathways and the phosphorylation of Stat3 and ERK1/2, leading to the production of kidney injury molecule-1 (KIM-1). Nevertheless, MAVS inhibition induced inflammation in the intestinal epithelial cells and KIM-1 production in tubular epithelial cells under K. oxytoca supernatant or IL-17 stimulation. Treatment with neutralizing anti-IL-17 antibody treatment had renoprotective effects. In contrast, lipopolysaccharide administration accelerated kidney injury in the murine diabetic kidney disease model. Conclusions Impaired MAVS signaling both in the kidney and intestine contributes to the disrupted homeostasis, leading to diabetic kidney disease progression. Controlling intestinal homeostasis may offer a novel therapeutic approach for this condition.

Growth Promotion of Giant Duckweed Spirodela polyrhiza (Lemnaceae) by Ensifer sp. SP4 Through Enhancement of Nitrogen Metabolism and Photosynthesis

Duckweeds (Lemnaceae) are representative producers in fresh aquatic ecosystems and also yield sustainable biomass for animal feeds, human foods, and biofuels, and contribute toward effective wastewater treatment; thus, enhancing duckweed productivity is a critical challenge. Plant-growth-promoting bacteria (PGPB) can improve the productivity of terrestrial plants; however, duckweed-PGPB interactions remain unclear and no previous study has investigated the molecular mechanisms underlying duckweed-PGPB interaction. Herein, a PGPB, Ensifer sp. strain SP4, was newly isolated from giant duckweed (Spirodela polyrhiza), and the interactions between S. polyrhiza and SP4 were investigated through physiological, biochemical, and metabolomic analyses. In S. polyrhiza and SP4 coculture, SP4 increased the nitrogen (N), chlorophyll, and ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents and the photosynthesis rate of S. polyrhiza by 2.5-, 2.5-, 2.7-, and 2.4-fold, respectively. Elevated photosynthesis increased the relative growth rate and biomass productivity of S. polyrhiza by 1.5- and 2.7-fold, respectively. Strain SP4 significantly altered the metabolomic profile of S. polyrhiza, especially its amino acid profile. N stable isotope analysis revealed that organic N compounds were transferred from SP4 to S. polyrhiza. These N compounds, particularly glutamic acid, possibly triggered the increase in photosynthetic and growth activities. Accordingly, we propose a new model for the molecular mechanism underlying S. polyrhiza growth promotion by its associated bacteria Ensifer sp. SP4, which occurs through enhanced N compound metabolism and photosynthesis. Our findings show that Ensifer sp. SP4 is a promising PGPB for increasing biomass yield, wastewater purification activity, and CO₂ capture of S. polyrhiza.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Microalgal transformation of food processing byproducts into functional food ingredients

Large amounts of food processing byproducts (FPBs) are generated from food manufacturing industries, the second-largest portion of food waste generation. FPBs may require additional cost for post-treatment otherwise cause environmental contamination. Valorization of FPBs into food ingredients by microalgae cultivation can save a high cost for organic carbon sources and nutrients from medium cost. This study reviews FPBs generation categorized by industry and traditional disposal. In contrast with the low-value production, FPBs utilization as the nutrient-abundant medium for microalgae can lead to high-value production. Due to the complex composition in FPBs, various pretreatment methods have been applied to extract the desired compounds and medium preparation. Using the FPB-based medium resulted in cost reduction and a productivity enhancement in previous literature. Although there are still challenges to overcome to achieve economic viability and environmental sustainability, the microalgal transformation of FPBs is attractive for functional food ingredients production.

Prevalence of chronic kidney disease in Asia: a systematic review and analysis

INTRODUCTION

The burden of chronic kidney disease (CKD) is growing rapidly around the world. However, there is limited information on the overall regional prevalence of CKD, as well as the variations in national prevalence within Asia. We aimed to consolidate available data and quantify estimates of the CKD burden in this region.

METHODS

We systematically searched MEDLINE, Embase and Google Scholar for observational studies and contacted national experts to estimate CKD prevalence in countries of Asia (Eastern, Southern and South Eastern Asia). CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or the presence of proteinuria. For countries without reported data, we estimated CKD prevalence using agglomerative average-linkage hierarchical clustering, based on country-level risk factors and random effects meta-analysis within clusters. Published CKD prevalence data were obtained for 16 countries (of the 26 countries in the region) and estimates were made for 10 countries.

RESULTS

There was substantial variation in overall and advanced (eGFR <30 mL/min/1.73 m2) CKD prevalence (range: 7.0%-34.3% and 0.1%-17.0%, respectively). Up to an estimated 434.3 million (95% CI 350.2 to 519.7) adults have CKD in Asia, including up to 65.6 million (95% CI 42.2 to 94.9) who have advanced CKD. The greatest number of adults living with CKD were in China (up to 159.8 million, 95% CI 146.6 to 174.1) and India (up to 140.2 million, 95% CI 110.7 to 169.7), collectively having 69.1% of the total number of adults with CKD in the region.

CONCLUSION

The large number of people with CKD, and the substantial number with advanced CKD, show the need for urgent collaborative action in Asia to prevent and manage CKD and its complications.

OUP accepted manuscript

Background

Previous reports on the prevalence of chronic kidney disease (CKD) in Asia have suggested important sex disparities but have been inconsistent in nature. We sought to synthesize available sex-disaggregated CKD prevalence data in Asia to quantify sex disparities in the region.

Methods

We systematically searched MEDLINE and Embase for observational studies involving ≥500 adults who reported sex-disaggregated CKD prevalence data in any of the 26 countries in East, Southeast and South Asia. For each study we calculated the female:male prevalence ratio (PR), with a ratio >1 indicating a higher female prevalence. For each country, log-transformed PRs were pooled using random effects meta-analysis. These were then combined using a fixed effects model, weighting by population size, to estimate a pooled PR for each of East, Southeast and South Asia and Asia overall.

Results

Sex-disaggregated data were available from 171 cohorts, spanning 15 countries and comprising 2 550 169 females and 2 595 299 males. Most studies (75.4%) came from East Asia (China, Taiwan, Japan and South Korea). Across Asia, CKD prevalence was higher in females {pooled prevalence 13.0% [95% confidence interval (CI) 11.3–14.9]} compared with males [pooled prevalence 12.1% (95% CI 10.3–14.1)], with a pooled PR of 1.07 (95% CI 0.99–1.17). Substantial heterogeneity was observed between countries. The pooled PRs for East, Southeast and South Asia were 1.11 (95% CI 1.02–1.21), 1.09 (0.88–1.36) and 1.03 (0.87–1.22), respectively.

Conclusions

Current evidence suggests considerable between-country and -region heterogeneity in the female:male PR of CKD. However, there remains a large part of the region where data on sex-specific CKD prevalence are absent or limited. Country-level assessment of the differential burden of CKD in females and males is needed to define locally relevant policies that address the needs of both sexes.

A protocol for nitrogen isotopic measurement of dissolved organic nitrogen with a combination of oxidation-denitrification and gas phase diffusion methods

Isotopic tracing technique is one of the most effective methods to identify nitrogen source and fate in aquatic environments. Although dissolved organic nitrogen (DON) is a key component in nitrogen cycles, information on nitrogen stable isotope ratios in DON (δ¹⁵N-DON) is limitedly available for its low recovery through a direct measurement. Indirect measurement is based on mass balance calculations and easy to use with high recovery of DON. However, in theory, the result from mass balance calculation is sensitive to the level of DON content, and its applicability remains to be examined for waters containing a variety of DON content in total dissolved nitrogen (TDN). In this study, we established a protocol for indirect measurement of δ¹⁵N-DON values based on the combination of multiple analytical methods. Precision and accuracy in the measurement were assessed by varying the composition of DON and dissolved inorganic nitrogen, and quantitation thresholds were presented at different acceptable levels. The results illustrated an advantage of the developed protocol possibly applicable to water samples particularly with low DON content that is commonly detected in freshwater. This method is expected to expand the use of isotope tracing techniques for understanding the nitrogen cycle in water environments.

Soluble receptor for advanced glycation end products protects from ischemia- and reperfusion-induced acute kidney injury

The full-length receptor for advanced glycation end products (RAGE) is a multiligand pattern recognition receptor. High-mobility group box 1 (HMGB1) is a RAGE ligand of damage-associated molecular patterns that elicits inflammatory reactions. The shedded isoform of RAGE and endogenous secretory RAGE (esRAGE), a splice variant, are soluble isoforms (sRAGE) that act as organ-protective decoys. However, the pathophysiologic roles of RAGE/sRAGE in acute kidney injury (AKI) remain unclear. We found that AKI was more severe, with enhanced renal tubular damage, macrophage infiltration, and fibrosis, in mice lacking both RAGE and sRAGE than in wild-type control mice. Using murine tubular epithelial cells (TECs), we demonstrated that hypoxia upregulated messenger RNA (mRNA) expression of HMGB1 and tumor necrosis factor α (TNF-α), whereas RAGE and esRAGE expressions were paradoxically decreased. Moreover, the addition of recombinant sRAGE canceled hypoxia-induced inflammation and promoted cell viability in cultured TECs. sRAGE administration prevented renal tubular damage in models of ischemia/reperfusion-induced AKI and of anti-glomerular basement membrane (anti-GBM) glomerulonephritis. These results suggest that sRAGE is a novel therapeutic option for AKI.

Impact of the relationship between hemoglobin levels and renal interstitial fibrosis on long-term outcomes in type 2 diabetes with biopsy-proven diabetic nephropathy

Background

Progression of renal anemia has been shown to be associated with advanced renal tubulointerstitial lesions. This retrospective study investigated the impact of lower hemoglobin (Hb) levels and renal interstitial fibrosis and tubular atrophy (IFTA) on long-term outcomes in type 2 diabetes with biopsy-proven diabetic nephropathy.

Methods

A total of 233 patients were enrolled. The severity of IFTA was scored according to the classification by the Renal Pathology Society. Patients were stratified according to baseline Hb tertiles by IFTA status. The outcomes were the first occurrence of renal events (requirement for dialysis or 50 % decline in estimated glomerular filtration rate from baseline) and all-cause mortality.

Results

At baseline, 151 patients had severe IFTA. There were no patients who have been received erythropoiesis-stimulating agents at the time of renal biopsy. The severity of IFTA was the independent pathological factor of lower Hb levels. During the mean follow-up period of 8.6 years (maximum, 32.4 years), 119 renal events and 42 deaths were observed. Compared with the combined influence of the highest tertile of Hb and mild IFTA, the risks of renal events were higher for the middle tertile and for the lowest tertile of Hb in severe IFTA, whereas the risk of renal events was higher for the lowest tertile of Hb in mild IFTA. The risk of mortality was higher for the lowest tertile of Hb only in severe IFTA. There were significant interactions of tertile of Hb and IFTA in renal events and mortality.

Conclusions

Impacts of lower Hb levels on long-term outcomes of diabetic nephropathy were greater in severe IFTA than in mild IFTA.

Two-year longitudinal trajectory patterns of albuminuria and subsequent rates of end-stage kidney disease and all-cause death: a nationwide cohort study of biopsy-proven diabetic kidney disease

INTRODUCTION

Data on the association between longitudinal trajectory patterns of albuminuria and subsequent end-stage kidney disease (ESKD) and all-cause mortality in diabetic kidney disease (DKD) are sparse.

RESEARCH DESIGN AND METHODS

Drawing on nationally representative data of 329 patients with biopsy-proven DKD and an estimated glomerular filtration rate above 30 mL/min/1.73 m² at the time of biopsy, we used joint latent class mixed models to identify different 2-year trajectory patterns of urine albumin to creatinine ratio (UACR) and assessed subsequent rates of competing events: ESKD and all-cause death.

RESULTS

A total of three trajectory groups of UACR were identified: 'high-increasing' group (n=254; 77.2%), 'high-decreasing' group (n=24; 7.3%), and 'low-stable' group (n=51; 15.5%). The 'low-stable' group had the most favorable risk profile, including the baseline UACR (median (IQR) UACR (mg/g creatinine): 'low-stable', 109 (50-138); 'high-decreasing', 906 (468-1740); 'high-increasing', 1380 (654-2502)), and had the least subsequent risk of ESKD and all-cause death among the groups. Although there were no differences in baseline characteristics between the 'high-decreasing' group and the 'high-increasing' group, the 'high-decreasing' group had better control over blood pressure, blood glucose, and total cholesterol levels during the first 2 years of follow-up, and the incidence rates of subsequent ESKD and all-cause death were lower in the 'high-decreasing' group compared with the 'high-increasing' group (incidence rate of ESKD (per 1000 person-years): 32.7 vs 77.4, p=0.014; incidence rate of all-cause death (per 1000 person-years): 0.0 vs 25.4, p=0.007).

CONCLUSIONS

Dynamic changes in albuminuria are associated with subsequent ESKD and all-cause mortality in DKD. Reduction in albuminuria by improving risk profile may decrease the risk of ESKD and all-cause death.

The relationship between the modified National Institute of Health activity and chronicity scoring system, and the long-term prognosis for lupus nephritis: A retrospective single-center study

BACKGROUND

The revision of International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification guidelines for lupus nephritis (LN) was suggested by a working group, who recommended a modified National Institute of Health (NIH) activity and chronicity scoring system to evaluate active and chronic LN lesions. However, whether this approach was useful for estimating long-term prognosis for LN patients is unclear.

METHODS

We conducted a retrospective cohort study in Japanese subjects with biopsy-proven LN, between 1977 and 2018. Pathologic lesions were evaluated based on ISN/RPS 2003 classifications and the modified NIH scoring system. Patients were grouped by activity index (low, 0-5; moderate, 6-11; high, 12-24), and chronicity index (low, 0-2; moderate, 3-5; high, 6-12). The primary outcome was a composite of end-stage kidney disease (ESKD) or all-cause death, and the secondary outcome was ESKD alone.

RESULTS

Sixty-six subjects with a median age of 31 years were included. During median follow-up (11.5 years), 15 patients reached the primary outcome: 10 had ESKD, four had died, and one had ESKD and died. Kaplan-Meier analysis showed that the cumulative primary outcome incidence increased with a higher chronicity index (log-rank trend p < 0.001). From multivariable survival analysis, moderate (hazard ratio [HR] 6.17, 95% confidence interval [CI] 1.14 to 33.20; p = 0.034) and high chronicity indices (HR 20.20, 95% CI 1.13 to 359.82; p = 0.041) were risk factors for the primary outcome.

CONCLUSION

Moderate and high chronicity indices were associated with an increased ESKD risk for LN.

Distribution and Community Composition of Anammox Bacteria in Shallow Groundwater of the Kathmandu Valley, Nepal

The abundance and diversity of anaerobic ammonium oxidation (anammox) bacteria were assessed in 152 groundwater samples in the Kathmandu Valley, Nepal. Anammox bacterial 16S rRNA genes were detected in 54% (37/68) of samples collected in the dry season at 1.6×10⁵–8.8×10⁶ copies L^–1, and in 60% (50/84) of samples collected in the wet season at 4.3×10⁴–1.2×10⁷ copies L^–1. The 16S rRNA genes of “Candidatus Brocadia”, “Candidatus Anammoxoglobus”, and five new deduced anammox bacterial phylotypes were detected in the shallow groundwater samples. Diverse anammox bacteria were broadly distributed in the shallow groundwater aquifer of the Kathmandu Valley.

Combined changes in albuminuria and kidney function and subsequent risk for kidney failure in type 2 diabetes

INTRODUCTION

Changes in albuminuria or estimated glomerular filtration rate (eGFR) can be used as a surrogate endpoint of end-stage kidney disease (ESKD) in people with type 2 diabetes. We investigated whether the combined changes in albuminuria and eGFR are more strongly associated with future risk of ESKD.

RESEARCH DESIGN AND METHODS

Using data from a multicenter observational cohort study of people with type 2 diabetes, we evaluated the association of percentage change in urine albumin to creatinine ratio (UACR) and/or annual change in eGFR over 2 years with subsequent ESKD risk.

RESULTS

Among 1417 patients with repeated albuminuria and eGFR over 2 years, 129 (9.1%) developed ESKD. Patients with >30% UACR decline had lower ESKD risk (HR 0.47; 95% CI 0.29 to 0.77), whereas those with >30% UACR increase had higher ESKD risk (HR 2.31; 95% CI 1.52 to 3.51), compared with those with minor UACR change. Patients with greater eGFR decline had an increased ESKD risk than those with minor eGFR change (a decline of <2.5 mL/min/1.73 m²/year): HR 4.19 (95% CI 1.87 to 9.38) and 2.89 (95% CI 1.32 to 6.33) for those with a decline of >5 and 2.5-5 mL/min/1.73 m²/year, respectively. When the combined changes in UACR and eGFR were used, the highest ESKD risk (HR 5.60; 95% CI 2.08 to 15.09) was observed among patients with >30% UACR increase and an eGFR decline of >5 mL/min/1.73 m²/year compared with those with a minor change in UACR and eGFR.

CONCLUSIONS

Combined changes in albuminuria and eGFR over 2 years were strongly associated with future risk of kidney failure in patients with type 2 diabetes.

Anti-fibrotic potential of erythropoietin signaling on bone marrow derived fibrotic cell

INTRODUCTION

The number of patients with end stage kidney disease (ESKD) are increasing world-side. While interstitial fibrosis (IF) is a common step for the progression to ESKD, therapeutic options for IF is still limited in clinical settings. We have reported that bone marrow-derived fibrotic cell, fibrocyte, is involved in the pathogenesis of kidney fibrosis. Also recent studies revealed that erythropoietin has protective effect on kidney diseases. However, it is unknown whether erythropoietin (EPO) inhibits fibrosis in progressive kidney injury. Therefore, we explored the impacts of EPO on kidney fibrosis with focusing on fibrocyte.

METHOD

Fibrocyte was differentiated from peripheral mononuclear cells of healthy donor. Fibrocyte was stimulated with transforming growth factor beta (TGF)-β with/without EPO treatment. Moreover, the therapeutic effect of EPO was evaluated in murine unilateral ureteral obstruction (UUO) model.

RESULT

TGF-β stimulation increased the expression of COL1 mRNA in fibrocyte. EPO signal reduced the expression of COL1 mRNA in dose dependent manner. EPO reduced mitochondrial oxidative stress and ameliorated mitochondrial membrane depolarization induced by TGF-β stimulation. Moreover, EPO reduced the mRNA expression of mitochondria related molecules, TRAF6, in fibrocyte. In addition, the count of CD45+/αSMA + double-positive fibrocyte was decreased in the EPO-administered UUO kidneys.

CONCLUSION

EPO signals function to prevent kidney fibrosis, particularly in fibrocyte. Regulating the renal accumulation of fibrocyte is a part of the anti-fibrotic functions of EPO.

Serum hemoglobin concentration, as a reflection of renal fibrosis, and risk of renal decline in early-stages of diabetic kidney disease: a nationwide, biopsy-based cohort study

BACKGROUND

Prognosticating disease progression in patients with diabetic kidney disease (DKD) is challenging, especially in the early stages of kidney disease. Anemia can occur in the early stages of kidney disease in diabetes. We therefore postulated that serum hemoglobin concentration, as a reflection of incipient renal tubulointerstitial impairment, can be used as a marker to predict DKD progression.

METHODS

Drawing on nationally representative data of patients with biopsy-proven DKD, 246 patients who had an estimated glomerular filtration rate (eGFR) ≥60 mL/min/1.73 m2 at renal biopsy were identified: aged 56 (45, 63); 62.6% men; Hb 13.3 (12.0, 14.5) g/dL; eGFR 76.2 (66.6, 88.6) mL/min/1.73 m2; urine albumin-to-creatinine ratio [UACR] 534 (100, 1480) mg/g Crea. Serum hemoglobin concentration were divided into quartiles: ≤12, 12.1-13.3, 13.4-14.5, and ≥14.6 g/dL. The association between serum hemoglobin concentration and the severity of renal pathological lesions was explored. A multivariable Cox regression model was used to estimate the risk of DKD progression (new onset of end-stage kidney disease, 50% reduction of eGFR, or doubling of serum creatinine). The incremental prognostic value of DKD progression by adding serum hemoglobin concentration to the known risk factors of DKD was assessed.

RESULTS

Serum hemoglobin levels negatively correlated with all renal pathological features, especially with the severity of interstitial fibrosis (ρ =-0.52; P < 0.001). During a median follow-up of 4.1 years, 95 developed DKD progression. Adjusting for known risk factors of DKD progression, the hazard ratio in the first, second, and third quartile (the fourth quartile as a reference) were 2.74 (95% CI 1.26-5.97), 2.33 (95% CI 1.07-5.75), and 1.46 (95% CI 0.71-3.64), respectively. Addition of the serum hemoglobin concentration to the known risk factors of DKD progression improved the prognostic value of DKD progression (the global chi-statistics increased from 55.1 to 60.8; P < 0.001).

CONCLUSIONS

Serum hemoglobin concentration, which reflects incipient renal fibrosis, can be useful for predicting DKD progression in the early stages of kidney disease.

Novel Plant-Associated Acidobacteria Promotes Growth of Common Floating Aquatic Plants, Duckweeds

Duckweeds are small, fast growing, and starch- and protein-rich aquatic plants expected to be a next generation energy crop and an excellent biomaterial for phytoremediation. Despite such an importance, very little is known about duckweed-microbe interactions that would be a key biological factor for efficient industrial utilization of duckweeds. Here we first report the duckweed growth promoting ability of bacterial strains belonging to the phylum Acidobacteria, the members of which are known to inhabit soils and terrestrial plants, but their ecological roles and plant-microbe interactions remain largely unclear. Two novel Acidobacteria strains, F-183 and TBR-22, were successfully isolated from wild duckweeds and phylogenetically affiliated with subdivision 3 and 6 of the phylum, respectively, based on 16S rRNA gene sequence analysis. In the co-culture experiments with aseptic host plants, the F-183 and TBR-22 strains visibly enhanced growth (frond number) of six duckweed species (subfamily Lemnoideae) up to 1.8-5.1 times and 1.6-3.9 times, respectively, compared with uninoculated controls. Intriguingly, both strains also increased the chlorophyll content of the duckweed (Lemna aequinoctialis) up to 2.4-2.5 times. Under SEM observation, the F-183 and TBR-22 strains were epiphytic and attached to the surface of duckweed. Taken together, our findings suggest that indigenous plant associated Acidobacteria contribute to a healthy growth of their host aquatic plants.

BMP9-ID1 signaling promotes EpCAM-positive cancer stem cell properties in hepatocellular carcinoma

The malignant nature of hepatocellular carcinoma (HCC) is closely related to the presence of cancer stem cells (CSCs). Bone morphologic protein 9 (BMP9), a member of the transforming growth factor‐beta (TGF‐β) superfamily, was recently reported to be involved in liver diseases including cancer. We aimed to elucidate the role of BMP9 signaling in HCC‐CSC properties and to assess the therapeutic effect of BMP receptor inhibitors in HCC. We have identified that high BMP9 expression in tumor tissues or serum from patients with HCC leads to poorer outcome. BMP9 promoted CSC properties in epithelial cell adhesion molecule (EpCAM)‐positive HCC subtype via enhancing inhibitor of DNA‐binding protein 1 (ID1) expression in vitro. Additionally, ID1 knockdown significantly repressed BMP9‐promoted HCC‐CSC properties by suppressing Wnt/β‐catenin signaling. Interestingly, cells treated with BMP receptor inhibitors K02288 and LDN‐212854 blocked HCC‐CSC activation by inhibiting BMP9‐ID1 signaling, in contrast to cells treated with the TGF‐β receptor inhibitor galunisertib. Treatment with LDN‐212854 suppressed HCC tumor growth by repressing ID1 and EpCAM in vivo. Our study demonstrates the pivotal role of BMP9‐ID1 signaling in promoting HCC‐CSC properties and the therapeutic potential of BMP receptor inhibitors in treating EpCAM‐positive HCC. Therefore, targeting BMP9‐ID1 signaling could offer novel therapeutic options for patients with malignant HCC.

Moderate alcohol consumption is associated with impaired insulin secretion and fasting glucose in non-obese non-diabetic men

AIMS/INTRODUCTION

A low insulin secretion capacity has been implicated in the high prevalence of non-obese diabetes in East Asians. As alcohol consumption alters insulin and glucose metabolism, we tested the hypothesis that alcohol consumption contributes to impaired insulin secretion and glucose intolerance in lean/normal-weight non-diabetic Japanese men.

MATERIALS AND METHODS

This cross-sectional study was undertaken among the residents of Shika town, Japan, between 2011 and 2017. A total of 402 non-diabetic men, including participants with normal fasting plasma glucose (FPG) and impaired FPG (FPG 5.6-6.9 mmol/L), and aged ≥40 years, were examined. FPG, the homeostasis model assessment of insulin secretion capacity (HOMA-B) and alcohol consumption were evaluated and compared between the body mass index (BMI) <25 and BMI ≥25 groups.

RESULTS

HOMA-B levels were lower in the BMI <25 group than in the BMI ≥25 group. Alcohol consumption correlated with a low HOMA-B level regardless of BMI, and, thus, the HOMA-B levels of alcohol drinkers were significantly lower in the BMI <25 group. A multivariable logistic regression analysis showed that alcohol consumption, even light-to-moderate consumption (1-25 g/day), was associated with significantly low levels of HOMA-B and impaired FPG in the BMI <25 group. Among participants with impaired FPG, a low level of HOMA-B was observed in alcohol drinkers, but not in non-drinkers. In contrast, light-to-moderate alcohol consumption was not related to HOMA-B or FPG in the BMI ≥25-group.

CONCLUSION

Alcohol consumption, even a small amount, might contribute to reductions in HOMA-B levels and impaired FPG in lean/normal-weight Japanese men.

Identification of candidate PAX2-regulated genes implicated in human kidney development

PAX2 is a transcription factor essential for kidney development and the main causative gene for renal coloboma syndrome (RCS). The mechanisms of PAX2 action during kidney development have been evaluated in mice but not in humans. This is a critical gap in knowledge since important differences have been reported in kidney development in the two species. In the present study, we hypothesized that key human PAX2-dependent kidney development genes are differentially expressed in nephron progenitor cells from induced pluripotent stem cells (iPSCs) in patients with RCS relative to healthy individuals. Cap analysis of gene expression revealed 189 candidate promoters and 71 candidate enhancers that were differentially activated by PAX2 in this system in three patients with RCS with PAX2 mutations. By comparing this list with the list of candidate Pax2-regulated mouse kidney development genes obtained from the Functional Annotation of the Mouse/Mammalian (FANTOM) database, we prioritized 17 genes. Furthermore, we ranked three genes-PBX1, POSTN, and ITGA9-as the top candidates based on closely aligned expression kinetics with PAX2 in the iPSC culture system and susceptibility to suppression by a Pax2 inhibitor in cultured mouse embryonic kidney explants. Identification of these genes may provide important information to clarify the pathogenesis of RCS, human kidney development, and kidney regeneration.

Carnitine/organic cation transporter 1 precipitates the progression of interstitial fibrosis through oxidative stress in diabetic nephropathy in mice

Carnitine/organic cation transporter 1 (OCTN1) is the only known uptake transporter for ergothioneine which is a food-derived strong antioxidant amino acid that is absorbed by OCTN1. We previously reported the roles of OCTN1/ergothioneine in the progression of kidney fibrosis in ischemic kidney disease. In this study, we evaluated the roles of OCTN1 in the progression of diabetic kidney disease. A diabetic kidney disease model was induced in octn1 knockout and wild-type mice by streptozotocin (STZ). Oxidative stress, represented by urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), were higher in the octn1 knockout mice. Azan- and Sirius red-positive areas increased significantly in the octn1 knockout mice. Gene expression was evaluated by cluster analysis, and shown to be different in the octn1 knockout mice compared with the wild-type mice. In a pathway analysis, the pathway associated with the cytoskeleton and cell adhesion increased. In accordance with interstitial fibrosis in octn1 knockout mice, gene expression of moesin in the injured kidney, known as an associated protein of cytoskeleton and cell membranes, was doubled 28 weeks after STZ injection. In addition, the moesin protein was expressed in a part of α-SMA-positive renal tubular epithelial cells. These findings were confirmed by cultured murine proximal tubular epithelial cells: The expression of moesin was induced under oxidative stress with hydrogen peroxide. These data indicate that OCTN1 would play some roles in progression of interstitial fibrosis under oxidative stress via moesin expression in diabetic kidney disease.

Indigenous bacteria, an excellent reservoir of functional plant growth promoters for enhancing duckweed biomass yield on site

The advantages of aquatic biomass production using wastewater as a cost-free fertilizer have recently been highlighted. Here, we report a successful study in which duckweed, Lemna gibba, biomass production in a food factory effluent containing low nitrogen and high salts was enhanced by employing customized plant growth-promoting bacteria (PGPB). Two common PGPB strains previously obtained from natural pond water, Acinetobacter calcoaceticus P23 and Pseudomonas fulva Ps6, hardly promoted the growth of duckweed; on the contrary, they inhibited its growth in treated factory wastewater, far different water conditions. Then, we asked if some indigenous wastewater bacteria could promote the growth of duckweed. We found that Chryseobacterium strains, a group of bacteria with limited nitrogen metabolism, were dominantly selected as effective PGPB. Moreover, we demonstrated that nitrogen limitation is the crucial environmental factor that induces the plant growth-inhibiting behavior of A. calcoaceticus P23 through competition for mineral nutrients with the host duckweed. This study uncovered points to be considered in PGPB technology to achieve efficient production of duckweed biomass in a factory effluent with unbalanced content of mineral nutrients.

Comparative Analysis of Microbial Communities in Fronds and Roots of Three Duckweed Species: Spirodela polyrhiza, Lemna minor, and Lemna aequinoctialis

The microbial communities inhabiting the fronds of duckweeds have not been investigated in as much detail as those on the roots. We herein examined the microbial communities in three duckweed species using 16S rRNA amplicon sequencing and compared them to those on the roots. The microbial compositions of the fronds were distinct from those of the roots in the three species. Various types of taxonomic bacteria, including rarely cultivated phyla, Acidobacteria, Armatimonadetes, and Verrucomicrobia, were also isolated from the fronds, but at a slightly lower abundance than those from the roots. These results suggest that duckweed fronds are an alternative source for isolating rare and novel microbes, which may otherwise be recalcitrant to cultivation using conventional strategies.

The characteristics of the immune cell profiles in peripheral blood in cholangiocarcinoma patients

BACKGROUND

Immune related cells are known to be closely related to the therapeutic effects and prognoses of cancer patients. In this study, we analyzed immune cell profiles (ICP) of cholangiocarcinoma patients (CCA).

METHODS

To measure the frequency of immune cells, peripheral blood mononuclear cells of 41 CCA and 10 healthy volunteers (HV) were analyzed by FACS.

RESULTS

There were significant differences between CCA and HV in ICP, and these differences were a consequence of tumor-bearing status, because many items in ICP before surgery were restored to levels in HV after surgery. Therefore, these changes were specifically attributable to cholangiocarcinoma, and we examined if they can function as biomarkers for therapeutic effects and prognoses. A shorter overall survival was associated with a lower frequency of helper T cells (HT) (p = 0.001), a higher frequency of effector regulatory T cells (eTregs) (p = 0.008), and a lower frequency of CD80 + eTregs (p = 0.024) in the best supportive care group, with a lower frequency of CD25 + naïve Tregs (nTregs) (p = 0.005) in the chemotherapy group, and with a lower frequency of OX40 + HT (p = 0.022), CD25 + CD8 + T cells (p = 0.017), and OX40 + CD8 + T cells (p = 0.032) in the surgery group. The recurrence factors were a higher frequency of CD4 + T cells (p = 0.009), CCR6 + nTregs (p = 0.014), and CXCR3 + nTregs (p = 0.012), and a lower frequency of PD-1 + HT (p = 0.006), OX40 + HT (p = 0.004), CD8 + T cells (p = 0.001), and CTLA-4 + CD8 + T cells (p = 0.036).

CONCLUSIONS

The ICP in CCA are specifically attributable to cholangiocarcinoma, and may be biomarkers for therapeutic effects and prognoses.

D-Serine inhibits the attachment and biofilm formation of methicillin-resistant Staphylococcus aureus

INTRODUCTION

Although therapeutic agents for methicillin-resistant Staphylococcus aureus (MRSA) are clinically available, MRSA infection is still a life-threatening disease. Bacterial attachment and biofilm formation contribute significantly to the initiation of MRSA infection. Controlling MRSA's attachment and biofilm formation might reduce the frequency of MRSA infection. According to recent data, some amino acids can reduce MRSA's attachment on plates; however, their precise inhibitory mechanisms remain unclear. Therefore, we explored the effect of the amino acids on bacterial adhesion and biofilm formation in vitro and in vivo MRSA infection models.

METHODS

We tested the inhibitory effect of amino acids on MRSA and Escherichia coli (E. coli) in the attachment assay. Moreover, we evaluated the therapeutic potential of amino acids on the in vivo catheter infection model.

RESULTS

Among the amino acids, D-Serine (D-Ser) was found to reduce MRSA's ability to attach on plate assay. The proliferation of MRSA was not affected by the addition of D-Ser; thus, D-Ser likely only played a role in preventing attachment and biofilm formation. Then, we analyzed the expression of genes related to attachment and biofilm formation. D-Ser was found to reduce the expressions of AgrA, SarS, IcaA, DltD, and SdrD. Moreover, the polyvinyl chloride catheters treated with D-Ser had fewer MRSA colonies. D-Ser treatment also reduced the severity of infection in the catheter-induced peritonitis model. Moreover, D-Ser reduced the attachment ability of E. coli.

CONCLUSION

D-Ser inhibits the attachment and biofilm formation of MRSA by reducing the expression of the related genes. Also, the administration of D-Ser reduces the severity of catheter infection in the mouse model. Therefore, D-Ser may be a promising therapeutic option for MRSA as well as E. coli infection.

Relationships between kidney dysfunction and left ventricular diastolic dysfunction: a hospital-based retrospective study

BACKGROUND

Preclinical left ventricular diastolic dysfunction (LVDD) is a high-risk state for heart failure. Kidney dysfunction is a known risk factor for heart failure, but its association with asymptomatic LVDD is not well-known.

METHODS

A hospital-based retrospective cohort study was conducted on patients who underwent echocardiogram between 2006 and 2016 to assess the association between baseline kidney function and LVDD on echocardiogram. E/e' ratio was defined as the ratio of peak velocity of early diastolic left ventricular inflow (E) to mitral annular velocity (e'). The primary outcome was time to development of LVDD, which was defined as E/e' ratio > 14. The changes in the E/e' ratio and other echocardiographic parameters were assessed using a mixed effects model.

RESULTS

Among 1167 patients, the mean age was 61 years, and the mean baseline E/e' ratio and ejection fraction were 9.6 and 69%, respectively. During a median follow-up of 3.2 years, 231 (19.8%) people developed LVDD. According to eGFR (mL/min/1.73 m²), the risk for LVDD based on hazard ratio [95% confidence interval (95% CI)] was 1.20 (0.82, 1.75) for 60 to < 90, 1.42 (0.87, 2.31) for 45 to < 60, and 2.57 (1.61, 4.09) for < 45 (P trend < 0.001). The adjusted risks (95% CI) for annual change in E/e' ratio was 0.09 (0.03, 0.14) overall and 0.28 (0.11, 0.45) in the lowest eGFR group; the trend in changes in annual E/e' ratio by baseline eGFR was significant (P trend = 0.01).

CONCLUSIONS

Relatively low kidney function was related with the risks for LVDD. Long-term cohort studies are warranted to confirm the association between LVDD and symptomatic heart failure in patients with kidney dysfunction.