髙橋 和男

PURPOSE: Recent studies have reported that sodium-glucose cotransporter (SGLT) 2 inhibitors ameliorate steatotic liver disease. We investigated the contribution of SGLT2 inhibitor-induced fluid loss due to glycosuria in hepatic ureagenesis for water conservation to the association between improvement of steatotic liver disease and the energy-consuming nature of hepatic ureagenesis. GENERAL METHODS: ob/ob mice fed a high-fat diet without carbohydrate restriction were administered luseogliflozin, an SGLT2 inhibitor, for eight weeks. FINDINGS: Luseogliflozin significantly decreased the liver weight, plasma aspartate aminotransferase and alanine aminotransferase levels, and fat content in mice with enhanced glycosuria (H-GlcV group). The ratio of urinary urea excretion decreased as a substitute for increased glucose excretion in the H-GlcV group. Luseogliflozin significantly increased liver urea content and tended to increase malate dehydrogenase (MDH)-1 activity. Liver MDH-1 activity was significantly positively correlated with liver urea content, suggesting that MDH-1-induced amino acid recruitment from the tricarboxylic acid cycle to the urea cycle may contribute to enhanced ureagenesis. In addition, liver weight was significantly negatively correlated with the liver urea content. CONCLUSIONS: Our data suggest that enhanced hepatic ureagenesis as a compensatory water conservation mechanism for glycosuria-induced fluid loss may be associated with amelioration of steatotic liver disease in SGLT2 inhibitor-treated ob/ob mice.

Immunoglobulin A nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide with most patients progressing to kidney failure. Although its pathophysiology remains incompletely understood, deposition of IgA-containing immune complexes in the glomerular mesangium induces mesangial cell proliferation and overproduction of extracellular matrix components and cytokines and chemokines, that lead to glomerular injury. The properties of nephritogenic IgA1 include abnormal glycosylation of its polymeric forms and its capacity to bind IgG autoantibodies to form immune complexes. Nephritogenic IgA1 is thought to be secreted by B cells originating from or residing in mucosa-associated lymphoid tissues (MALT), such as gut-associated lymphoid tissues (GALT) and nasopharynx-associated lymphoid tissues (NALT). However, little is known how the immune abnormalities in MALT elevate the circulatory levels of nephritogenic IgA. This review summarizes fundamental insights into IgA production and its regulation in MALT in general, provides an overview of the immune abnormalities in the MALT of patients with IgAN relevant to the production of abnormally glycosylated IgA, and summarizes relevant emerging treatments tested in clinical trials.

BACKGROUND: IgA nephropathy (IgAN) is a mucosal immune-associated disease characterized by the overproduction of galactose-deficient IgA1 (Gd-IgA1) and formation of nephritogenic immune complexes. Epstein-Barr virus (EBV), which preferentially infects IgA+ B cells, has been implicated in IgAN pathogenesis, although its role remains unclear. Given mucosa involvement, we characterized breast milk B cells as available representatives of mucosal tissue to better understand the pathogenesis of IgAN. METHODS: We performed a phenotypic analysis of B cells (CD19+), plasmablasts (CD38+), and CD138+ cells (representing migrating pre-plasma cells, CPC) in the breast milk of IgAN and healthy mothers (HC). EBV infection of cells was detected by using EBV-encoded RNA (EBER). B cell differentiation, IgA/Gd-IgA1 expression, and homing-related markers were characterized using complementary cytometric and microscopic approaches. RESULTS: Breast milk from mothers with IgAN contains a significantly higher proportion of EBER+ B cells compared with HC. Moreover, the proportion of EBER+ CPCs in the breast milk of IgAN mothers is significantly higher than in HC. B cells present in the breast milk of mothers with IgAN exhibit a higher expression of the mucosal homing receptor CCR9 compared to B cells from HC. IgA+ B cells from healthy mothers exhibit a higher overall frequency of surface Gd-IgA1 expression and lack CD138 marker and thus could be classified as memory B cells or plasmablasts considering their class-switched phenotype. In contrast, breast milk from IgAN mothers was enriched for Gd-IgA1+ CD138+ CPC cells, indicating a shift toward terminally differentiated antibody-producing cells. These findings suggest disease-associated alterations in B cell differentiation and compartmentalization rather than increased mucosal Gd-IgA1 production per se. CONCLUSION: Despite the limited number of analyzed samples, we detected interesting differences in B cells in the breast milk of IgAN mothers and HC. The analysis of B cell populations in the breast milk of IgAN mothers indicates EBV-associated B cell dysregulation. The enrichment of EBV+ CPC and Gd-IgA1+ CPC in the breast milk of IgAN mothers agrees with a former model proposing aberrant mucosal B cell differentiation and trafficking involvement in IgAN pathogenesis.

IgA nephropathy (IgAN) is characterized by the deposition of galactose-deficient IgA1 (Gd-IgA1)-containing immune complexes into kidney mesangium leading to glomerular inflammation and injury. In patients with active IgAN non-responding to renin-angiotensin system blocking drugs (RASBs), corticosteroids (CSs) are recommended. Although CSs reduce significantly serum levels of Gd-IgA1, IgA-containing immune complexes, and proteinuria, their clinical effect in IgAN is variable. Because IgAN patients exhibit abnormal serum concentration of several endogenous steroid metabolites, some of which exhibit immuno-protective/regulating functions, we analyzed serum metabolites which could predict clinical response to CS therapy. This prospective study was performed in 18 male IgAN patients to identify potential biomarkers for personalized CS therapy. Using LC-MS set of 85 steroid metabolites was tested in the sera of IgAN patients before CS therapy initiation to identify those with statistically different level in patients clinically responding and not-responding to CS therapy. Responders were those subjects whose proteinuria decrease below 1 g/day after 6-12 months of CS therapy. Statistical analysis revealed significant and clinically relevant differences in the steroid profile between responders and non-responders. The key and consistent finding across the entire analysis is that non-responder status is associated with globally higher level of almost all analyzed steroids. The response of IgAN patients to CS therapy could be predicted by measuring the serum levels of selected steroid metabolites to receive steroid profile. Observation needs to be confirmed in large cohorts of various ethnic origin to be applicable for routine clinical protocols.

IgA nephropathy (IgAN) is characterized by glomerular deposits of IgA-containing immune complexes (IgA-ICs), which are suspected to originate from circulation. However, the composition of these ICs is not fully understood. To address this gap in knowledge, we performed label-free quantitative mass-spectrometry analyses of glomerular and circulatory IgA-ICs with a focus on complement proteins. Glomeruli of patients with IgAN compared to healthy glomeruli had greater amounts of several complement-system proteins associated with classical, alternative, and terminal pathways, including complement factor H-related (CFHR) proteins 1, 2, 3, and 5, C1q chains B and C, and properdin. Circulatory IgA-ICs of patients with IgAN vs. healthy controls had a greater abundance of complement proteins CFHR1, C1q chains A, B, and C, and properdin. Furthermore, levels of several complement proteins in circulatory IgA-ICs of IgAN patients were reduced after immunosuppressive therapy (i.e., tonsillectomy combined with pulse steroid therapy) but not in patients on comprehensive supportive therapy. CFHR1 exhibited the greatest decrease (Fold change = 48.16, P < 0.0001). These data together revealed the complexity of complement proteome in glomerular and circulatory IgA-ICs and suggested an association of complement regulatory proteins, such as CFHR1, with pathogenic IgA-ICs.

N-Glycans are modified by various glycosyltransferases in a protein-selective manner and critically control protein functions. Here, we investigated the mechanisms for the protein substrate selectivity of N-acetylglucosaminyltransferase-V (GnT-V or MGAT5) in the mouse kidney. Through lectin-assisted proteomics, two metalloproteases on the apical surface of tubules, alanyl aminopeptidase (ANPEP) and meprin α (MEP1A), were identified as the major GnT-V substrates. We further determined the GnT-V-modified glycosites and revealed that the modified sites are highly accessible and clustered within the C-terminal domains, suggesting some structural requirements for GnT-V action. Single-cell transcriptomics revealed partial overlap of Mgat5 and Anpep or Mep1a, excluding the possibility that Mgat5 is limited in the same cell type as the major substrates. Furthermore, upon polarization of epithelial cells, the GnT-V products accumulate to the apical side, suggesting that polarized subcellular trafficking is involved in selective modification. Our findings provide insights into the mechanisms of protein-selective glycosylation in vivo.

Tryptophan (TRP) metabolism through the kynurenine pathway generates multiple biologically active metabolites with diverse immunomodulatory effects, but their roles in glomerulonephritis (GN), particularly in innate immunity, remain poorly understood. Using a nephrotoxic serum-induced GN (NTS-GN) model, we first analyzed mice deficient in key TRP-metabolizing enzymes of the kynurenine pathway: Indoleamine 2,3-dioxygenase 1 and 2 (IDO1 and IDO2), and kynurenine 3-monooxygenase (KMO), and found that Ido1-deficient mice exhibited exacerbated kidney injury and glomerular neutrophil infiltration, whereas Ido2 deficiency had no significant impact. In contrast, Kmo-deficient mice showed reduced crescent formation. Unexpectedly, the concentration of kynurenic acid (KYNA), a downstream metabolite of IDO1, was elevated in the kidney cortex of Ido1-deficient mice. Exogenous KYNA administration improved survival, ameliorated renal injury, and reduced neutrophil infiltration in Ido1-deficient mice, indicating its protective effect against antibody-mediated injury. Moreover, KYNA suppressed immune complex-mediated neutrophil spreading, attenuated FcγR-dependent Syk phosphorylation, and reduced VEGF secretion in vitro. Our results position KYNA as a key modulator of neutrophil-driven inflammation in antibody-mediated GN. This study uncovers distinct roles for kynurenine pathway enzymes and highlights the TRP-KYNA pathway as a promising immunometabolic target for controlling innate immune responses in GN.

Structural variations of N-glycans critically regulate glycoprotein functions and are involved in various human diseases. N-Acetylglucosaminyltransferase-III (GnT-III or MGAT3) is highly expressed in the brain and kidney and is an N-glycan branching enzyme that biosynthesizes the unique N-glycan branch designated as bisecting GlcNAc. Its roles in Alzheimer's disease and cancer have been revealed, but the functions of bisecting GlcNAc in the kidney are poorly understood. Here, we show that kidneys in the GnT-III-knockout (KO) mouse exhibit impaired body fluid balance and present interstitial edema. To understand the molecular mechanisms further, we biochemically purified the glycoproteins modified by GnT-III in the mouse kidney and identified these proteins using proteomics. We found that the proteins involved in the pathway for angiotensin II (Ang II) metabolism are modified by GnT-III, and that the subcellular localization of angiotensin-converting enzyme was altered in GnT-III-KO cells. Furthermore, the pathology in models of Ang II-related disease was slightly more severe in GnT-III-KO than in wild-type mice. Our data indicate a protective role for bisecting GlcNAc in the mouse kidney, highlighting a newly described link between specific N-glycan structures and renal functions.

OBJECTIVES: Sivelestat sodium hydrate (SSH) may be effective in the early stage of acute respiratory distress syndrome (ARDS) before the neutrophil extracellular trap scaffold structure is complete. Therefore, patients with suppression of fibrinolysis (SF) before the secondary fibrinolytic process might benefit from SSH administration. The primary aim of this study was to determine the effect of the SF state and combination therapy on the effect of SSH administration. METHODS: We retrospectively reviewed the data of patients diagnosed with ARDS at Fujita Health University Hospital between July 2005 and December 2016. Patients with ARDS were stratified into the SF and hyperfibrinolysis (HF) groups. Using the fibrin degradation product (FDP)/D-dimer ratio, cut-off values were set as follows: FDP/D-dimer >2 for the HF group and FDP/D-dimer ≤2 for the SF group. The 28-day mortality was the primary endpoint. RESULTS: In total, 168 patients (71 in the HF group and 97 in the SF group) were included in the analysis. The mortality within 28 days was not different based on SSH administration in either group (HF group: p=0.956, SF group: p=0.957). In the SF group, the mortality rate within 28 days in SSH-treated patients who received antithrombotic drugs was significantly higher than that in patients who received SSH only (p<0.05). However, this finding was not present in the HF group (p=0.786). CONCLUSIONS: Concomitant use of SSH and antithrombotic drugs might worsen the treatment outcome of patients with ADRS in the SF state.

BACKGROUND: IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis. Elevation in the blood levels of aberrantly glycosylated IgA1 is a crucial initial step in IgAN pathogenesis. Here, we aimed to determine the longitudinal changes in the serum levels of IgA1 O- and N-glycoforms in patients with IgAN receiving different treatments. METHODS: We enrolled Japanese patients diagnosed with primary IgAN: 10 patients who underwent tonsillectomy and corticosteroid therapy (T-CST), 7 who received corticosteroid therapy (CST), 8 who received conservative therapy (CO), and 5 with other renal diseases who received corticosteroid therapy (ORD) as disease controls. IgA was purified from patient sera collected at diagnosis and post-treatment. After sample preparation, O-glycoforms of the hinge region (HR) and N-glycoforms of the fragment crystallizable region were analyzed using high-resolution mass spectrometry (MS). RESULTS: The MS analysis of O-glycoforms of IgA1 showed that the relative abundance of IgA1 with 3GalNAc3Gal, which we previously identified as a characteristic IgA1 O-glycoform in IgAN, decreased post-treatment only in the T-CST group (P = 0.0195). Regarding N-glycoforms, the relative abundance of fucosylated N-glycan at asparagine (Asn)340 increased in the IgAN group compared with that in the ORD group (P = 0.0189) and decreased post-treatment only in the T-CST group (P = 0.0195). CONCLUSION: The MS analysis of O- and N-glycoforms of IgA1 revealed substantial changes in their abundance in the T-CST group but not in the CST, CO, and ORD groups. Our study provides new insights into how specific treatments alter the IgA1 glycoform abundance.

INTRODUCTION: Clinical epidemiological data on monoclonal gammopathy of renal significance (MGRS) are lacking. In this retrospective observational study, MGRS was compared with B-cell or plasma cell malignancies (BCM/PCM) with renal involvement to clarify differences in their clinical features. METHODS: Among the 1408 renal biopsies performed at our hospital, 25 MGRS and 18 BCM/PCM patients were identified. We investigated baseline characteristics and hematologic parameters of MGRS in reference to BCM/PCM using multivariable analysis. Cox proportional hazards analysis was performed for end-stage kidney disease (ESKD) and all-cause mortality. RESULTS: Comparing the MGRS with the BCM/PCM, mean differences in creatinine level, estimated glomerular filtration rate, and clonal bone marrow plasma cell percentage were - 2.76 mg/dL, 27.72 mL/min/1.73 m2, and - 18.86%, respectively (all P < 0.001). MGRS group had a predominance of glomerular lesions such as immunoglobulin-associated amyloidosis, cryoglobulinemic GN, and MIDD, and a lower risk of acute kidney injury/acute renal disease compared to BCM/PCM. During a median observation period of 23.7 months, clone-directed therapy was performed in 32.0% of patients in the MGRS group, compared to 83.3% of patients in the BCM/PCM group. Compared with BCM/PCM, MGRS had a hazard ratio of 0.66 (95% confidence interval (CI) 0.23-1.92, P = 0.45) for ESKD and 0.33 (95% CI 0.11-1.03, P = 0.06) for death in multivariate logistic regression analysis. CONCLUSIONS: The clinical characteristics of MGRS and BCM/PCM with monoclonal immunoglobulin-associated renal disease are disparate. Understanding these differences is crucial for developing tailored clinical approaches and therapeutic strategies to improve patient outcome.

BACKGROUND/AIM: Effective monitoring of antibiotic use is essential for antimicrobial stewardship. While Days of Therapy (DOT) is commonly used to assess antibiotic consumption, it does not fully capture changes in antimicrobial spectrum during de-escalation. To address this, the Days of Antibiotic Spectrum Coverage (DASC) metric-calculated using a spectrum score weighted by antimicrobial breadth-was developed. This study aimed to evaluate the utility of DASC in identifying trends in antibiotic de-escalation across hospital wards and to determine whether it can serve as a reliable metric for assessing the appropriateness of antibiotic use at the departmental level. PATIENTS AND METHODS: This single-center retrospective study was conducted at an acute care community hospital in Japan, which has 21 clinical departments and 250 inpatient beds, including four intensive care unit beds. We retrospectively analyzed trends in inpatient antimicrobial use from May 2019 to March 2023 using DASC to assess the effectiveness of a newly instituted antimicrobial stewardship program. RESULTS: DASC/DOT in the Otolaryngology and respiratory medicine wards showed a significant decreasing trend, but a significant increase was observed in both the surgery and general practice wards. We observed no significant trends in the other wards. In the surgery and respiratory medicine wards, broad-spectrum antimicrobials such as carbapenems were frequently used. CONCLUSION: DASC highlighted differences in the trends of antimicrobial de-escalation at the ward level and identified targets for antimicrobial stewardship intervention.

Recombinant tissue-type plasminogen activators (rtPA) effectively dissolve blood clots and improve symptoms in patients with acute ischemic stroke and myocardial infraction. Although rtPA are used in patients taking antiplatelets or anticoagulants to improve clinical outcomes, combination therapy may increase the risk of hemorrhagic transformation (HT) and intracerebral hemorrhage (ICH). However, few studies have investigated the risk of HT and ICH associated with these combination therapies. This study aimed to investigate the adverse-event and drug-drug interaction signals for HT and ICH under combination therapy with alteplase and various antiplatelets or anticoagulants, using the Japanese Adverse Drug Event Report database. Adverse-event signals were evaluated using the reporting odds ratio and information components, and drug-drug interaction signals were studied using the Ω shrinkage measure, additive, multiplicative, and Chi-square statistics models. We also investigated predictors of HT and ICH, time-to-onset, and outcomes in patients receiving alteplase. HT and/or ICH signals were detected in patients receiving alteplase in combination with aspirin, P2Y12 inhibitors, cilostazol, ozagrel sodium, direct oral anticoagulants, warfarin potassium, heparin group, or argatroban. Hypertension and diabetes mellitus were significant risk factors for alteplase-induced HT. Most HT and ICH events occurred within 1 day after alteplase administration, and more than 60% of affected patients were not in recovery. In conclusion, continued monitoring is required in patients receiving alteplase in combination with any of the eight types of antiplatelets or the aforementioned anticoagulants. Additionally, the occurrence of HT or ICH within 1 day post-alteplase administration should be considered in patients with hypertension or diabetes mellitus. The findings from this study may help in understanding the risk of HT and ICH induced by rtPA in patients taking antiplatelet or anticoagulant medications, as well as in promoting the appropriate use of rtPA. Further prospective observational studies and randomized controlled trials are needed to assess these finding.

Demyelinating diseases including multiple sclerosis (MS) are chronic inflammatory diseases of the central nervous system. Indoleamine 2,3-dioxygenase 2 (Ido2) is a recently identified as catalytic enzyme involved in the rate-limiting step of the tryptophan-kynurenine pathway that influences susceptibility to inflammatory diseases. However, the pathological role of Ido2 in demyelination remains unclear. In this study, we investigated whether Ido2 deficiency influences the pathogenesis of proteolipid protein transgenic (Plp tg) mice, an animal model of chronic demyelination. Ido2 deficiency exacerbates impairments of motor function in the locomotor activity test, wire hanging test, and rotarod test. Ido2 deficiency caused severe demyelination associated with CD68-positive microglial activation in Plp tg mice. In the cerebellum of Plp tg mice, Ido2 deficiency significantly increased the expression of Tnfα. Ido2 deficiency reduced tryptophan metabolite kynurenine (KYN) levels and subsequent aryl hydrocarbon receptor (AhR) activity, which play an important role in anti-inflammatory response. These results suggest that Ido2 has an important role in preventing demyelination through AhR. Taken together, Ido2 could be a potential therapeutic target for demyelinating diseases.

Acute lung injury (ALI), which occurs in association with sepsis, trauma, and coronavirus disease 2019 (COVID-19), is a serious clinical condition with high mortality. Excessive platelet-leukocyte aggregate (PLA) formation promotes neutrophil extracellular trap (NET) release and thrombosis, which are involved in various diseases, including ALI. Macrophage-1 antigen (Mac-1, CD11b/CD18), which is expressed on the surface of leukocytes, is known to promote NET formation. This study aimed to elucidate the role of Mac-1 in extracellular histone-induced ALI. Exogenous histones were administered to Mac-1-deficient mice and wild-type (WT) mice with or without neutrophil or platelet depletion, and several parameters were investigated 1 h after histone injection. Depletion of neutrophils or platelets improved survival time and macroscopic and microscopic properties of lung tissues, and decreased platelet-leukocyte formation and plasma myeloperoxidase levels. These improvements were also observed in Mac-1-/- mice. NET formation in Mac-1-/- bone marrow neutrophils (BMNs) was significantly lower than that in WT BMNs. In conclusion, our findings suggest that Mac-1 is associated with exacerbation of histone-induced ALI and the promotion of NET formation in the presence of activated platelets.

Objective The objective of this study was to estimate the humoral immune response evaluated by immunoglobulin G (IgG) against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD-IgG) following the third mRNA COVID-19 vaccination in patients with kidney disease who received immunosuppressive treatment. Methods The primary outcome was RBD-IgG levels after the third SARS-CoV-2 vaccination. The primary comparison was the RBD-IgG levels between patients with kidney disease who received immunosuppressive treatment (n=124) and those who did not (n=33). Results The RBD-IgG levels were significantly lower in the patients with kidney disease who received immunosuppressive treatment than in those who did not receive immunosuppressive treatment. The RBD-IgG levels were lower in patients treated with glucocorticoid monotherapy than in those who did not receive immunosuppressive treatment. Even in patients who received ≤ 5 mg prednisolone, the RBD-IgG levels were significantly lower. Nine of the 10 patients who received rituximab within one year before the first vaccination did not experience seroconversion after the third vaccination. Meanwhile, all nine patients who received rituximab only after the second vaccination experienced seroconversion, even if B cell recovery was insufficient. Patients treated with mycophenolate mofetil plus glucocorticoid plus belimumab had significantly lower RBD-IgG levels than those treated with mycophenolate mofetil plus glucocorticoid. Conclusions The RBD-IgG levels were lower in patients with kidney disease who received immunosuppressive treatment than in those who did not receive immunosuppressive treatment. Low-dose glucocorticoid monotherapy affected the humoral immune response following the third mRNA COVID-19 vaccination.

Abstract Background In 2020, the Committee of Clinical Practical Guideline for IgA Nephropathy (IgAN) revised the clinical practice guidelines. Herein, we conducted a questionnaire survey to assess the potential discrepancies between clinical practice guidelines and real-world practice in Japan. Methods A web-based survey of members of the Japanese Society of Nephrology was conducted between November 15 and December 28, 2021. Results A total of 217 members (internal physicians: 203, pediatricians: 14) responded to the questionnaire. Of these respondents, 94.0% answered that the clinical practice guidelines were referred to “always” or “often.” Approximately 66.4% respondents answered that histological grade (H-Grade) derived from the “Clinical Guidelines for IgA nephropathy in Japan, 3rd version” and the “Oxford classification” were used for pathological classification. Moreover, 73.7% respondents answered that the risk grade (R-grade) derived from the “Clinical Guidelines for IgA nephropathy in Japan, 3rd version” was referred to for risk stratification. The prescription rate of renin–angiotensin system blockers increased based on urinary protein levels (&gt; 1.0 g/day: 88.6%, 0.5–1.0 g/day: 71.0%, &lt; 0.5 g/day: 25.0%). Similarly, the prescription rate of corticosteroids increased according to proteinuria levels (&gt; 1.0 g/day: 77.8%, 0.5–1.0 g/day: 52.8%, &lt; 0.5 g/day: 11.9%). The respondents emphasized on hematuria when using corticosteroids. In cases of hematuria, the indication rate for corticosteroids was higher than in those without hematuria, even if the urinary protein level was 1 g/gCr or less. Few severe infectious diseases or serious deterioration in glycemic control were reported during corticosteroid use. Conclusion Our questionnaire survey revealed real-world aspects of IgAN treatment in Japan.

Extracellular histones induce endothelial damage, resulting in lung haemorrhage; however, the underlying mechanism remains unclear. Factor XIII, as a Ca2+-dependent cross-linking enzyme in blood, mediates fibrin deposition. As another isozyme, transglutaminase 2 (TG2) has a catalytic activity distributing in most tissues. Herein, we investigated whether TG2 promotes fibrin deposition and mediates the adhesion of platelets to ECs in histone-induced acute lung injury (ALI). We evaluated the lung histology and the adhesion of platelets to endothelial cells (ECs) after injecting histones to wild-type (WT) C57BL/6J and TG2 knockout (TG2-/-) mice, and administered a TG2 inhibitor (NC9) to WT mice. Pulmonary haemorrhage was more severe in TG2-/- mice than that in WT mice. The area of fibrin deposition and the proportion of CD41+CD31+ cells were lower in TG2-/- mice than in WT mice. Pre-treatment of NC9 decreased the area of fibrin deposition and the proportion of CD41+CD31+ cells in WT mice. These results suggest that TG2 prevents from pulmonary haemorrhage in ALI by promoting the adhesion of platelets to ECs and the fibrin deposition.

OBJECTIVES: Cardiovascular and renal diseases are closely related. Brain natriuretic peptide (BNP) and urinary albumin are established predictors for cardiac and renal morbidities, respectively. To date, no reports have investigated the combined predictive value of BNP and urinary albumin for long-term cardiovascular-renal events in patients with chronic kidney disease (CKD). The aim of this study was to investigate this theme. METHODS: Four hundred eighty-three patients with CKD were enrolled into this study and followed-up for 10 years. The endpoint was cardiovascular-renal events. RESULTS: During the median follow-up period of 109 months, 221 patients developed cardiovascular-renal events. Log-transformed BNP and urinary albumin were identified as independent predictors for cardiovascular-renal events, with a hazard ratio of 2.59 (95% confidence interval [CI], 1.81-3.72) and 2.27 (95% CI, 1.82-2.84) for BNP and urinary albumin, respectively. For the combined variables, the group with high BNP and urinary albumin had a markedly higher risk (12.41-times; 95% CI 5.23-29.42) of cardiovascular-renal events compared with that of the group with low BNP and urinary albumin. Adding both variables to a predictive model with basic risk factors improved the C-index (0.767, 0.728 to 0.814, p=0.009), net reclassification improvement (0.497, p<0.0001), and integrated discrimination improvement (0.071, p<0.0001) more than each of them alone. CONCLUSIONS: This is the first report to demonstrate that the combination of BNP and urinary albumin can stratify and improve the predictability of long-term cardiovascular-renal events in CKD patients.

Purpose: Coronavirus disease 2019 (COVID-19) mRNA vaccines are used worldwide to prevent severe symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. IgA nephropathy (IgAN) is the most common form of glomerular injury after COVID-19 vaccination; however, because of the low frequency of such events, only a few reports have been published. A large pharmacovigilance database of real-world spontaneous adverse event (AE) reports is essential for evaluating the drug-associated safety signals regarding rare AEs. Herein, we aimed to investigate the frequency of IgAN after the COVID-19 vaccination, using the Japanese Adverse Drug Event Report (JADER) database. Methods: Data on drug-associated AEs reported between April 2004 and May 2022 were obtained from the JADER database on the Pharmaceuticals and Medical Devices Agency website. To evaluate the safety signals for the targeted AEs, reporting odds ratios (RORs), information components (ICs), and their 95% confidence intervals (CIs) were calculated using two-by-two contingency tables. Results: A total of 697,885 cases were included in the analysis. Safety signals were detected for IgAN (ROR: 6.49, 95% CI: 4.38-9.61; IC: 2.27, 95% CI: 1.70-2.83). Of 30 cases for IgAN associated with COVID-19 mRNA vaccines, 16 had information available on time to onset. Of the 16 cases, 11 occurred ≤2 days after vaccination, and two occurred >28 days after vaccination. Conclusion: These results suggest that, compared with other drugs, COVID-19 vaccination is associated with a higher frequency of IgAN. Monitoring of gross hematuria following COVID-19 vaccination should be needed.

BACKGROUND/AIM: Sepsis is a life-threatening biological condition that induces systemic tissue and organ dysfunction and confers a high mortality risk. Although the use of hydrocortisone in combination with ascorbic acid and thiamine (HAT therapy) significantly reduced mortality from sepsis or septic shock in a previous study, it did not improve mortality in subsequent randomized controlled trials (RCTs). Therefore, no definitive conclusion has been established on the benefits of HAT therapy for sepsis or septic shock. We performed a meta-analysis to assess the treatment outcomes of HAT therapy in patients with sepsis or septic shock. PATIENTS AND METHODS: We searched databases (PubMed/MEDLINE, Embase, Scopus and Cochrane Library) for RCTs using the terms "ascorbic acid", "thiamine", "sepsis", "septic shock", and "RCT". The primary outcome of this meta-analysis was the mortality rate, and the secondary outcomes were the incidence of new-onset acute renal injury (AKI), intensive care unit (ICU) length of stay (ICU-LOS), change in the Sequential Organ Failure Assessment (SOFA) score within 72 hours, and duration of vasopressor use. RESULTS: Nine RCTs were identified and included in the outcome evaluation. HAT therapy did not improve the 28-day and ICU mortality, new-onset AKI, ICU-LOS, or SOFA scores. However, HAT therapy significantly shortened the duration of vasopressor use. CONCLUSION: HAT therapy did not improve mortality, the SOFA score, renal injury, or ICU-LOS. Further studies are needed to confirm whether it shortens the duration of vasopressor use.

A long-term high-fat diet (HFD) causes obesity and changes in renal lipid metabolism and lysosomal dysfunction in mice, causing renal damage. Sodium-glucose co-transporter inhibitors, including phlorizin, exert nephroprotective effects in patients with chronic kidney disease, but the underlying mechanism remains unclear. A HFD or standard diet was fed to adult C57BL/6J male mice, and phlorizin was administered. Lamellar body components of the proximal tubular epithelial cells (PTECs) were investigated. After phlorizin administration in HFD-fed mice, sphingomyelin and ceramide in urine and tissues were assessed and label-free quantitative proteomics was performed using kidney tissue samples. Mitochondrial elongation by fusion was effective in the PTECs of HFD-fed obese mice under phlorizin administration, and many lamellar bodies were found in the apical portion of the S2 segment of the proximal tubule. Phlorizin functioned as a diuretic, releasing lamellar bodies from the apical membrane of PTECs and clearing the obstruction in nephrons. The main component of the lamellar bodies was sphingomyelin. On the first day of phlorizin administration in HFD-fed obese mice, the diuretic effect was increased, and more sphingomyelin was excreted through urine than in vehicle-treated mice. The expressions of three peroxisomal β-oxidation proteins involved in fatty acid metabolism were downregulated after phlorizin administration in the kidneys of HFD-fed mice. Fatty acid elongation protein levels increased with phlorizin administration, indicating an increase in long-chain fatty acids. Lamellar bodies accumulated in the proximal renal tubule of the S2 segment of the HFD-fed mice, indicating that the urinary excretion of lamellar bodies has nephroprotective effects.

Galactose (Gal)-deficient IgA1 (Gd-IgA1) is involved in IgA nephropathy (IgAN) pathogenesis. To reflect racial differences in clinical characteristics, we assessed disease- and race-specific heterogeneity in the O-glycosylation of the IgA1 hinge region (HR). We determined serum Gd-IgA1 levels in Caucasians (healthy controls [HCs], n = 31; IgAN patients, n = 63) and Asians (HCs, n = 20; IgAN patients, n = 60) and analyzed profiles of serum IgA1 HR O-glycoforms. Elevated serum Gd-IgA1 levels and reduced number of Gal residues per HR were observed in Caucasians. Reduced number of N-acetylgalactosamine (GalNAc) residues per HR and elevated relative abundance of IgA1 with three HR O-glycans were common features in IgAN patients; these features were associated with elevated blood pressure and reduced renal function. We speculate that the mechanisms underlying the reduced GalNAc content in IgA1 HR may be relevant to IgAN pathogenesis.

Information on immune checkpoint inhibitor-induced vasculitides is limited, and predictors for this condition have not been identified. Therefore, we have examined the frequency of immune checkpoint inhibitor-induced vasculitides by analyzing the data recorded in the Japanese Adverse Drug Event Report database. Data from April 2004 to March 2020 were extracted, and vasculitides as an immune-related adverse event was defined according to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides. Adverse event signals were recognized as significant when the reporting odds ratio estimates and lower limits of the corresponding 95% confidence intervals exceeded 1. The use of nivolumab showed a significant signal for vasculitides. Furthermore, significant signals of polymyalgia rheumatica were found when the patients were treated with nivolumab, pembrolizumab, and ipilimumab. In addition, the frequencies of nivolumab- and pembrolizumab-induced polymyalgia rheumatica were higher in patients aged ≥70 years and female patients, respectively. Polymyalgia rheumatica was reported in 38 patients treated with nivolumab; 31 (82%) of these were either in recovery or in remission. Further, polymyalgia rheumatica was reported in 17 patients treated with pembrolizumab; 13 (76%) of these were in recovery or remission, while three (18%) were not. Polymyalgia rheumatica was reported in 12 patients treated with ipilimumab; seven (58%) of these were in recovery or remission. Our study highlights that careful monitoring for the symptom of PMR (e.g., bilateral pain in shoulder and pelvic girdles) is required when the patients are aged &amp;gt;70 years and have been treated with nivolumab and when the patients are women and have been treated with pembrolizumab.

Background: Immunoglobulin A nephropathy (IgAN) primary glomerulonephritis is characterized by the deposition of circulating immune complexes (CIC) composed of polymeric (p)IgA1 molecules with altered O-glycans (Gd-IgA1) and anti-glycan antibodies in the kidney mesangium. The mesangial IgA deposits and serum IgA1 contain predominantly lambda (λ) light (L) chain, but the nature and origin of such IgA remains enigmatic Methods: We analyzed λ L chain expression in peripheral blood B cells of 30 IgAN patients, 30 healthy controls (HC), and 18 membranous nephropathy patients selected as disease controls (Non-IgAN). Results: In comparison to HC and Non-IgAN, in peripheral blood surface/membrane bound (mb)-Gd-IgA1+ cells from IgAN patients express predominantly λ L chain. In contrast, total mb-IgA+, mb-IgG+, and mb-IgM+ cells were preferentially positive for kappa (κ) L chain, in all analyzed groups. Although minor in comparison to κ L chain, λ L chain subsets of mb-IgG+, mb-IgM,+ and mb-IgA+ cells were significantly enriched in IgAN in comparison to Non-IgAN and/or HC. In contrast to HC, the peripheral blood of IgAN patients was enriched for λ+ mb-Gd-IgA1,+ CCR10,+ and CCR9+ cells, which preferentially home to the upper respiratory and digestive tract, respectively. Furthermore, we observed that mb-Gd-IgA1+ cell populations comprise more CD138+ cells and plasmablasts (CD38+) in comparison to total mb-IgA+ cells. Conclusions: Peripheral blood of IgAN patients is enriched for migratory λ+ mb-GdIgA1+ B cells, with the potential to home to mucosal sites where Gd-IgA1 could be produced during local respiratory or digestive tract infections.

BACKGROUND: Early detection and prediction of cisplatin-induced acute kidney injury (Cis-AKI) are essential for the management of patients on chemotherapy with cisplatin. This study aimed to evaluate the performance of a prediction model for Cis-AKI. METHODS: Japanese patients, who received cisplatin as the first-line chemotherapy at Fujita Health University Hospital, were enrolled in the study. The main metrics for evaluating the machine learning model were the area under the curve (AUC), accuracy, precision, recall, and F-measure. In addition, the rank of contribution as a predictive factor of Cis-AKI was determined by machine learning. RESULTS: A total of 1,014 and 226 patients were assigned to the development and validation data groups, respectively. The current prediction model showed the highest performance in patients 65 years old and above (AUC: 0.78, accuracy: 0.77, precision: 0.38, recall: 0.70, F-measure: 0.49). The maximum daily cisplatin dose and serum albumin levels contributed the most to the prediction of Cis-AKI. CONCLUSION: Our prediction model for Cis-AKI performed effectively in older patients.

OBJECTIVES: Favipiravir is an antiviral which is being evaluated for the treatment of COVID-19. Use of favipiravir is associated with elevation of serum uric acid levels. Risk factors for the occurrence of hyperuricemia are unclear. METHODS: Specimens from patients who received 10 days of favipiravir in a previous clinical trial (jRCTs041190120) were used. Serum favipiravir concentrations were measured by LC-MS. Factors associated with development of hyperuricemia were investigated by the logistic regression analysis. Optimal cut-off values for the baseline serum uric acid levels and steady-state serum favipiravir concentrations in predicting the occurrence of hyperuricemia were determined by ROC curve analysis. RESULTS: Among 66 COVID-19 patients who were treated with favipiravir for 10 days, the steady-state serum favipiravir concentrations were significantly correlated with serum uric acid levels. High baseline serum uric acid levels and steady-state serum favipiravir concentrations during therapy were factors associated with the development of hyperuricemia. The cut‑off baseline serum uric acid level and steady-state serum favipiravir concentration during favipiravir administration to predict hyperuricemia were 3.7 mg/dL and 46.14 μg/mL, respectively. CONCLUSIONS: Patients who have high baseline serum uric acid levels or achieve high steady-state serum favipiravir concentrations during therapy are susceptible to hyperuricemia.

AIMS: The number of cancer survivors with cardiovascular disease is increasing. However, the effect of cancer on body fluid regulation remains to be clarified. In this study, we evaluated body osmolyte and water imbalance in rats with hepatocellular carcinoma. MAIN METHODS: Wistar rats were administered diethylnitrosamine, a carcinogenic drug, to establish liver cancer. We analyzed tissue osmolyte and water content, and their associations with aldosterone secretion. KEY FINDINGS: Hepatocellular carcinoma rats had significantly reduced body mass and the amount of total body sodium, potassium, and water. However, these rats had significantly increased relative tissue sodium, potassium, and water content per tissue dry weight. Furthermore, these changes in sodium and water balance in hepatocellular carcinoma rats were significantly associated with increased 24-h urinary aldosterone excretion. Supplementation with 0.25% salt in drinking water improved body weight reduction associated with sodium and water retention in hepatocellular carcinoma rats, which was suppressed by treatment with spironolactone, a mineralocorticoid receptor antagonist. Additionally, the urea-driven water conservation system was activated in hepatocellular carcinoma rats. SIGNIFICANCE: These findings suggest that hepatocellular carcinoma induces body mass loss in parallel with activation of the water conservation system including aldosterone secretion and urea accumulation to retain osmolyte and water. The osmolyte and water retention at the tissue level may be a causative factor for ascites and edema formation in liver failure rats.

Huntingtin-associated protein 1 (HAP1) is abundantly expressed in the neurons of the central nervous system and forms unique intracytoplasmic inclusions of unknown function called "stigmoid bodies" (STBs). Transmission electron microscopy has revealed that the STBs are aggregates of granules containing cavities with a diameter of 0.5-3 µm. Small STBs fuse to form larger STBs, the size of which is said to vary depending on the developmental growth stage and brain region. Light microscopy can only reveal that these STBs have similar circular shapes, due to its limited resolution. Therefore, light microscopy is only fit for the study of the STB distribution and quantitative changes. We, herein, suggest the adoption of correlative light and electron microscopy, that combines confocal laser scanning microscopy and scanning electron microscopy, as the method allowing us to identify the HAP1-positive STBs in formalin-fixed paraffin-embedded (FFPE) sections. This approach allows us to study the three-dimensional morphology of immunolabeled objects in histopathological specimens. The STBs in FFPE sections of murine hypothalami reflected the transmission electron microscopic images of Epon-embedded STBs, although we were not able to observe any organelle covering the STBs of the FFPE sections. Furthermore, we were able to reconstruct the three-dimensional structure of the STB and we identified it to be of spherical form, covered with mitochondria and rough endoplasmic reticulum, and bearing a cluster of cavities in the center. In the future, we might gain new insights by comparing the 3D structure of the STB between different neurons and under a variety of conditions.

BACKGROUND: The benefits of vitamin D receptor activators (VDRAs) for patients with chronic kidney disease are well recognized. However, the optimal criteria for patient selection, dosage forms, and duration providing the highest benefit and the least potential risk remain to be confirmed. MATERIALS AND METHODS: The study population was derived from the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis, a multicenter prospective cohort study of 1520 incident dialysis patients. According to the VDRA usage status in March 2015 (interim report), the 967 patients surviving after March 2015 were classified into three groups: without VDRA (NV, n = 177), oral VDRA (OV, n = 447), and intravenous VDRA (IV, n = 343). Mortality rates were compared using the log-rank test, and factors contributing to all-cause mortality were examined using both univariate and multivariate Cox proportional hazard regression analyses. RESULTS: There were 104 deaths (NV, n = 27; OV, n = 53; IV, n = 24) during the follow-up period (1360 days, median), and significant differences in cumulative survival rates were observed between the three groups (p = 0.010). Moreover, lower all-cause mortality was associated with IV versus NV (hazard ratio, 0.46 [95% confidence interval 0.24-0.89]; p = 0.020). CONCLUSION: This study demonstrated the impact of the VDRA dosage form on the short-term survival of incident hemodialysis patients during the introduction period. Our results suggest that relatively early initiation of intravenous VDRA in patients beginning hemodialysis may have some clinical potential.

Acute lung injury (ALI) occurs in patients with severe sepsis and has a mortality rate of 40%-60%. Severe sepsis promotes the release of histones from dying cells, which can induce platelet aggregation, activate coagulation and cause endothelial cell (EC) death. We previously reported that the expression of membrane complement receptor type 1-related gene Y (Crry)/p65, which plays a principal role in defence against abnormal activation of complement in the blood, is reduced in response to peritoneal mesothelial cell injury, and we hence hypothesized that a similar mechanism occurs in pulmonary ECs. In this study, we examined the role of Crry/p65 in histone-mediated ALI using an experimental animal model. In ALI model mice, exposure to extracellular histones induces lung injury and results in a decrease in Crry/p65 expression. The levels of lactic acid dehydrogenase (LDH), a marker of cell damage, were significantly increased in the serum of ALI model compared with vehicle mice. The significant inverse correlation between the expression of Crry/p65 and LDH levels in plasma revealed an association between Crry/p65 expression and cell damage. The levels of complement component 3a (C3a) were also significantly increased in the serum of the ALI model compared with vehicle mice. Notably, a C3a receptor antagonist ameliorated lung injury induced by histones. We hypothesize that extracellular histones induce complement activation via down-regulation of Crry/p65 and that C3a might serve as a therapeutic target for the treatment of ALI.