Adverse reactions and effects on renal function of COVID-19 vaccines in patients with IgA nephropathy.

BACKGROUND: Although vaccination has been reported to reduce the morbidity and severity of COVID-19 infection in patients with kidney disease, gross hematuria is frequently reported following vaccination in patients with IgA nephropathy. We investigated the frequency of gross hematuria following COVID-19 vaccination and its effect on renal function in IgA nephropathy patients. METHODS: Adverse reactions after two or more COVID-19 vaccine doses were investigated in 295 IgA nephropathy patients attending Osaka Cty general hospital from September 2021 to November 2022. We compared differences in background characteristics and other adverse reactions between groups with and without gross hematuria after vaccination, and examined changes in renal function and proteinuria. RESULTS: Twenty-eight patients (9.5%) had gross hematuria. The median age of patients with and without gross hematuria was 44 (29-48) and 49 (42-61) years, respectively, indicating a significant difference. The percentage of patients with microscopic hematuria before vaccination differed significantly between those with (65.2%) and without (32%) gross hematuria. Adverse reactions, such as fever, chills, headache and arthralgia, were more frequent in patients with gross hematuria. There was no difference in renal functional decline after approximately 1 year between patients with and without gross hematuria. We also found no significant changes in estimated glomerular filtration rate or proteinuria before and after vaccination in the gross hematuria group. However, some patients clearly had worsening of renal function. CONCLUSIONS: While COVID-19 vaccination is beneficial, care is required since it might adversely affect renal function in some patients.

Effects of molidustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, on sodium dynamics in hypertensive subtotally nephrectomized rats.

Hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitors were developed for treatment of renal anemia. Patients applicable for HIF-PHD inhibitor treatment experience complications such as chronic kidney disease, whereby water and electrolyte homeostasis is disrupted. The effects of hypoxia-inducible factor stabilization on salt accumulation in the setting of reduced renal function remain unclear. In the present study, we investigated the effect of a HIF-PHD inhibitor, molidustat, on salt distribution and excretion in rats with subtotal nephrectomy-induced chronic kidney disease. Male Wistar rats were subjected to 5/6 nephrectomy. After confirming blood pressure elevation (>150 mmHg, at 4 weeks after surgery), rats were treated with molidustat. After 1 week of treatment, molidustat did not significantly improve blood cell volume or blood pressure. Distribution of sodium, potassium, and water in skin, carcass, and bone samples was not affected by molidustat. Furthermore, molidustat had no significant effect on urinary sodium excretion or concentration in response to acute oral salt loading (1 g/kg). In conclusion, molidustat did not affect distribution or excretion of salt in rats subjected to a model of nephron loss.

Efficient conversion to Cypridina luciferin from Cypridina luciferyl sulfate, coupled with enzymatic sulfation of acetic acid.

In Cypridina (Vargula) hilgendorfii, Cypridina luciferin is converted from Cypridina luciferyl sulfate by a sulfotransferase with adenosine 3', 5'-diphosphate (PAP), and is used for the luminescence reaction of Cypridina luciferase. We found that the luminescence activity of crude extracts of C. hilgendorfii was significantly stimulated by the addition of acetic acid. This stimulation may be explained by an efficient supply of PAP from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) catalyzed by a sulfotransferase. Thus, acetic acid acts as a sulfate acceptor from PAPS, followed by forming acetyl sulfate and PAP. The structure of acetyl sulfate was identified using mass spectrometry and it spontaneously decomposed to acetic acid and free sulfate ion in aqueous solutions. This enzymatic conversion from Cypridina luciferyl sulfate to Cypridina luciferin could be coupled with acetic acid and PAPS by a sulfotransferase.

The angiotensin II receptor-neprilysin inhibitor LCZ696 attenuates the progression of proteinuria in type 2 diabetic rats.

We examined the effects of the angiotensin receptor-neprilysin inhibitor LCZ696 on overt proteinuria and renal injury in type 2 diabetic Otsuka-Long- Evans-Tokushima-Fatty (OLETF) rats. Aged OLETF rats were also treated with either valsartan or valsartan plus hydralazine for comparison. LCZ696 caused greater attenuation of the progression of proteinuria than either valsartan alone or valsartan combined with hydralazine. Reduced glomerular injury and tubulointerstitial fibrosis were also observed in LCZ696-treated rats. Moreover, LCZ696 prevented increases in blood urea nitrogen (BUN) and creatinine levels. These data suggest that LCZ696 elicits a reno-protective effect against type 2 diabetes with overt proteinuria.

Correction to: A nationwide survey on clinical practice patterns and bleeding complications of percutaneous native kidney biopsy in Japan.

In the original publication, some errors have been found in the alignment of Table 9. The corrected table is given below.

A nationwide survey on clinical practice patterns and bleeding complications of percutaneous native kidney biopsy in Japan.

BACKGROUND: Practice patterns and bleeding complications of percutaneous native kidney biopsy (PNKB) have not recently been investigated and the Japanese Society of Nephrology performed a nationwide questionnaire survey in 2018. METHODS: The survey consisted of nine sections about PNKB: (1) general indications; (2) indications for high-risk patients; (3) informed consent; (4) pre-biopsy evaluation; (5) procedures; (6) sedation; (7) post-biopsy hemostasis, bed rest, and examinations; (8) bleeding complications; and (9) specimen processing. A supplementary survey examined bleeding requiring transcatheter arterial embolization (TAE). RESULTS: Overall, 220 directors of facilities (nephrology facility [NF], 168; pediatric nephrology facility [PF], 52) completed the survey. Indications, procedures, and monitoring protocols varied across facilities. Median lengths of hospital stay were 5 days in NFs and 6 days in PFs. Gauge 14, 16, 18 needles were used in 5%, 56%, 33% in NFs and 0%, 63%, 64% in PFs. Mean limits of needle passes were 5 in NFs and 4 in PFs. The bed rest period was 16-24 h in 60% of NFs and 65% of PFs. Based on 17,342 PNKBs, incidence rates of macroscopic hematuria, erythrocyte transfusion, and TAE were 3.1% (NF, 2.8%; PF, 6.2%), 0.7% (NF, 0.8%; PF, 0%), and 0.2% (NF, 0.2%; PF, 0.06%), respectively. Forty-six percent of facilities processed specimens all for light microscopy, immunofluorescence, and electron microscopy, and 21% processed for light microscopy only. Timing of bleeding requiring TAE varied among PNKB cases. CONCLUSION: Wide variations in practice patterns of PNKB existed among facilities, while PNKBs were performed as safely as previously reported.

Effect of a SGLT2 inhibitor on the systemic and intrarenal renin-angiotensin system in subtotally nephrectomized rats.

We aimed to examine the effects of a sodium glucose co-transporter 2 (SGLT2) inhibitor on systemic and intrarenal renin-angiotensin system (RAS) in subtotally nephrectomized non-diabetic rats, a model of chronic kidney disease (CKD). Oral administration of the selective SGLT2 inhibitor, TA-1887 (10 mg/kg/day), for 10 weeks induced glycosuria. However, plasma renin activity, plasma angiotensinogen levels, kidney angiotensin II contents and renal injury were not significantly affected by TA-1887. These data indicate that chronic treatment with an SGLT2 inhibitor does not activate the systemic and intrarenal RAS in subjects with non-diabetic CKD.

Integrated proteomics identified novel activation of dynein IC2-GR-COX-1 signaling in neurofibromatosis type I (NF1) disease model cells.

Neurofibromatosis type 1 (NF1) tumor suppressor gene product, neurofibromin, functions in part as a Ras-GAP, and though its loss is implicated in the neuronal abnormality of NF1 patients, its precise cellular function remains unclear. To study the molecular mechanism of NF1 pathogenesis, we prepared NF1 gene knockdown (KD) PC12 cells, as a NF1 disease model, and analyzed their molecular (gene and protein) expression profiles with a unique integrated proteomics approach, comprising iTRAQ, 2D-DIGE, and DNA microarrays, using an integrated protein and gene expression analysis chart (iPEACH). In NF1-KD PC12 cells showing abnormal neuronal differentiation after NGF treatment, of 3198 molecules quantitatively identified and listed in iPEACH, 97 molecules continuously up- or down-regulated over time were extracted. Pathway and network analysis further revealed overrepresentation of calcium signaling and transcriptional regulation by glucocorticoid receptor (GR) in the up-regulated protein set, whereas nerve system development was overrepresented in the down-regulated protein set. The novel up-regulated network we discovered, "dynein IC2-GR-COX-1 signaling," was then examined in NF1-KD cells. Validation studies confirmed that NF1 knockdown induces altered splicing and phosphorylation patterns of dynein IC2 isomers, up-regulation and accumulation of nuclear GR, and increased COX-1 expression in NGF-treated cells. Moreover, the neurite retraction phenotype observed in NF1-KD cells was significantly recovered by knockdown of the dynein IC2-C isoform and COX-1. In addition, dynein IC2 siRNA significantly inhibited nuclear translocation and accumulation of GR and up-regulation of COX-1 expression. These results suggest that dynein IC2 up-regulates GR nuclear translocation and accumulation, and subsequently causes increased COX-1 expression, in this NF1 disease model. Our integrated proteomics strategy, which combines multiple approaches, demonstrates that NF1-related neural abnormalities are, in part, caused by up-regulation of dynein IC2-GR-COX-1 signaling, which may be a novel therapeutic target for NF1.

[Measurement of Liver Fibrosis Marker Targeting Sugar Chain Marker].

The degree of liver fibrosis progression is an important factor in hepatocarcinogenesis, and monitoring liver fibrosis is important for predicting and preventing hepatocellular carcinoma. It is proportional to the appearance of a new hepatitis C therapy, or the expectation of liver fibrosis therapy, and liver fibrosis research is attracting attention. Although the Gold Standard for the diagnosis of liver fibrosis is liver biopsy, various problems, such as in the difficulty of invasive and frequent measurement, exist. The present non-invasive examination methods for the assessment of liver fibrosis also have a problem in the fields of organ specificity and diagnostic performance. Using a fully automated immunoassay system "HISCL", an assay system based on the lectin bound sugar reaction which is not an antigen-bound antibody reaction was developed. Measurements using the fully automated immunoassay system "HISCL" series and HISCL M2BPGi assay kit facilitated rapid assay (17 minutes) with a small sample volume (10 µL). Serum M2BPGi values can be used in various ways, such as for assessment of the risk and treatment associated with hepatocellular carcinoma, reflecting the liver fibrosis stage. Furthermore, many studies are currently in progress. The development of a new assay system for the detection of a cancer production sugar chain marker is expected in the future owing to the advent of a lectin-bound sugar chain reaction system.

Heme-related molecules induce rapid production of neutrophil extracellular traps.

BACKGROUND: Pulmonary endothelial cell damages caused by neutrophil overactivation could result in acute lung injuries including transfusion-related acute lung injury (TRALI). We previously reported that heme-related molecules derived from hemolysis induced the production of reactive oxygen species from neutrophils. Recently, neutrophil extracellular traps (NETs) have been demonstrated to associate with the onset of TRALI. STUDY DESIGN AND METHODS: In this study, neutrophils' morphologic changes induced by the heme-related molecule hemin were confirmed to be NETs via confocal laser scanning microscopy and electron microscopy (EM). Additionally, concentrations of hemin in red blood cell (RBC) components were measured via enzyme-linked immunosorbent assay and possible contribution of these molecules to the onset of TRALI was discussed. RESULTS: SYTOX green staining observation via confocal laser scanning microscopy revealed that neutrophil morphology changed rapidly upon addition of hemin. The nuclei began to be enlarged and become segmented after 5 minutes, and NET-like structures were released from neutrophils after 15 minutes. In EM observation, NET-like structures appeared after 10 minutes and the nucleoplasm was partially separated from the nuclear membrane, which were consistent with the features of NET formation. These structures stained positively for both myeloperoxidase and histone H3 antibodies. CONCLUSION: Thus, our results suggest that hemin induced NETs in 15 minutes, a quicker reaction than NET induction by phorbol myristate acetate requiring 3 hours. Moreover, since RBC components, especially those with long-term storage, contained sufficient hemin concentration to induce NETs, special attention to hemolysis of stored RBC components is important.

[Laparoscopic abdominoperineal resection after preoperative chemoradiotherapy for advanced carcinoma associated with anal fistula].

The patient was a 71-year-old man who was diagnosed with anal fistula 50 years previously. He complained of mucous and bloody stools. He was diagnosed with a carcinoma associated with anal fistula after biopsy. Image examination showed that the tumor was filled with mucinous substances and that it had invaded the levator ani muscle, with left external iliac and left inguinal lymph node metastases. Therefore, preoperative chemoradiotherapy for locally advanced cancer was administered. After chemoradiotherapy, the tumor and metastatic lymph nodes reduced in size. We performed laparoscopic abdominoperineal resection. Histopathologically, the tumor was revealed as a mucinous adenocarcinoma, but no cancer cells were present on the surgical margin. This case suggested that preoperative chemoradiotherapy could be effective for locally advanced carcinoma associated with anal fistula.

Non-activated T and B lymphocytes become morphologically distinguishable after detergent treatment.

T and B lymphocytes are difficult to distinguish morphologically even with electron microscopy, and antibodies are generally used to make the distinction. A specific reagent, consisting of nonionic and cationic detergents, is used for leukocyte differentiation using the Sysmex automated blood analyzer. This reagent increases cell membrane porosity and enables the introduction of fluorescent dye into leukocytes. In this study, we investigated the effect of this specific detergent on the morphology of T and B lymphocytes. T and B lymphocytes were obtained by density gradient centrifugation and magnetic cell sorting, with a minimum of 90% isolation efficiency. T and B lymphocytes were then treated with the specific detergent and fluorescent dye, and their distribution was analyzed based on side scatter and fluorescence intensity using general-purpose flow cytometry (FCM). Fluorescent images were observed using a confocal laser scanning microscope (CLSM), cellular inner structures using a transmission electron microscopy (TEM), and cell surfaces using a scanning electron microscope (SEM). The ratio of cholesterol to total lipid in cell membranes of B and T lymphocytes was measured using a fluorescent assay kit. The distribution of fluorescence intensity was different between T and B lymphocyte clusters, according to the FCM analysis. CLSM observations revealed that the fluorescent dye mainly stained cytoplasmic organelles. FCM, TEM, and SEM observations revealed that B lymphocytes are more likely to lose surface antigens and intracellular organelles than T lymphocytes, which allows the visual distinction between T and B lymphocytes. The ratio of cholesterol to total lipid in T lymphocyte membranes had tendency higher than that in B lymphocyte membranes. In this study, we demonstrate that cells with differences in cell membrane cholesterol amounts, such as B and T lymphocytes could be identified using an inexpensive detergent, as an alternative to costly antibodies.

Oxidative stress/angiotensinogen/renin-angiotensin system axis in patients with diabetic nephropathy.

Although recent studies have proven that renin-angiotensin system (RAS) blockades retard the progression of diabetic nephropathy, the detailed mechanisms of their reno-protective effects on the development of diabetic nephropathy remain uncertain. In rodent models, it has been reported that reactive oxygen species (ROS) are important for intrarenal angiotensinogen (AGT) augmentation in the progression of diabetic nephropathy. However, no direct evidence is available to demonstrate that AGT expression is enhanced in the kidneys of patients with diabetes. To examine whether the expression levels of ROS- and RAS-related factors in kidneys are increased with the progression of diabetic nephropathy, biopsied samples from 8 controls and 27 patients with type 2 diabetes were used. After the biopsy, these patients were diagnosed with minor glomerular abnormality or diabetes mellitus by clinical and pathological findings. The intensities of AGT, angiotensin II (Ang II), 4-hydroxy-2-nonenal (4-HNE), and heme oxygenase-1 (HO-1) were examined by fluorescence in situ hybridization and/or immunohistochemistry. Expression levels were greater in patients with diabetes than in control subjects. Moreover, the augmented intrarenal AGT mRNA expression paralleled renal dysfunction in patients with diabetes. These data suggest the importance of the activated oxidative stress/AGT/RAS axis in the pathogenesis of diabetic nephropathy.

Tonsillectomy has beneficial effects on remission and progression of IgA nephropathy independent of steroid therapy.

BACKGROUND: Indication of tonsillectomy in IgA nephropathy is controversial. The purpose of this study was to examine the efficacy of tonsillectomy on remission and progression of IgA nephropathy. METHODS: We conducted a single-center 7-year historical cohort study in 200 patients with biopsy-proven IgA nephropathy. Study outcomes were clinical remission defined as disappearance of urine abnormalities at two consecutive visits, glomerular filtration rate (GFR) decline defined as 30% GFR decrease from baseline and GFR slope during the follow-up. RESULTS: Seventy of the 200 patients received tonsillectomy. Tonsillectomy was associated with increased incidence of clinical remission (P+0.01, log-rank test) and decreased incidence of GFR decline (P=0.01, log-rank test). After adjustment for age and gender, hazard ratios in tonsillectomy were 3.90 (95% confidence interval 2.46-6.18) for clinical remission and 0.14 (0.02-1.03) for GFR decline. After further adjustment for laboratory (baseline mean arterial pressure, GFR, 24-h proteinuria and hematuria score), histological (mesangial score, segmental sclerosis or adhesion, endocapillary proliferation and interstitial fibrosis) or treatment variables (steroid and renin-angiotensin system inhibitors), similar results were obtained in each model. Even after exclusion of 69 steroid-treated patients, results did not change. GFR slopes in tonsillectomy and non-tonsillectomy groups were 0.60±3.65 and -1.64±2.59 mL/min/1.73 m2/year, respectively. In the multiple regression model, tonsillectomy prevented GFR decline during the follow-up period (regression coefficient 2.00, P=0.01). CONCLUSION: Tonsillectomy was associated with a favorable renal outcome of IgA nephropathy in terms of clinical remission and delayed renal deterioration even in non-steroid-treated patients.

Urinary angiotensinogen reflects the activity of intrarenal renin-angiotensin system in patients with IgA nephropathy.

BACKGROUND: A potential contribution of local activation of the renin-angiotensin system (RAS) to the pathogenesis of renal injury has been indicated by evidence for blood pressure-independent renoprotective effects of angiotensin II (AngII) receptor blockers (ARBs). The present study was performed to test the hypothesis that urinary angiotensinogen provides a specific index of intrarenal RAS status in patients with immunoglobulin A (IgA) nephropathy. METHODS: This paper is a survey of urine specimens from three groups: healthy volunteers, patients with IgA nephropathy and patients with minor glomerular abnormality (MGA). Patients with hypertension, diabetes, reduced glomerular filtration rate and/or who were under any medication were excluded from this study. Urinary angiotensinogen levels were measured by a sandwich enzyme-linked immunosorbent assay system. RESULTS: Urinary angiotensinogen levels were not different between healthy volunteers and patients with MGA. However, urinary angiotensinogen levels, renal tissue angiotensinogen expression and AngII immunoreactivity were significantly higher in patients with IgA nephropathy than in patients with MGA. Baseline urinary angiotensinogen levels were positively correlated with renal angiotensinogen gene expression and AngII immunoreactivity but not with plasma renin activity or the urinary protein excretion rate. In patients with IgA nephropathy, treatment with an ARB, valsartan (40 mg/day), significantly increased renal plasma flow and decreased filtration fraction, which were associated with reductions in urinary angiotensinogen levels. CONCLUSION: These data indicate that urinary angiotensinogen is a powerful tool for determining intrarenal RAS status and associated renal derangement in patients with IgA nephropathy.

An integrated approach of differential mass spectrometry and gene ontology analysis identified novel proteins regulating neuronal differentiation and survival.

MS-based quantitative proteomics is widely used for large scale identification of proteins. However, an integrated approach that offers comprehensive proteome coverage, a tool for the quick categorization of the identified proteins, and a standardized biological study method is needed for helping the researcher focus on investigating the proteins with biologically important functions. In this study, we utilized isobaric tagging for relative and absolute quantification (iTRAQ)-based quantitative differential LC/MS/MS, functional annotation with a proprietary gene ontology tool (Molecular Annotation by Gene Ontology (MANGO)), and standard biochemical methods to identify proteins related to neuronal differentiation in nerve growth factor-treated rat pheochromocytoma (PC12) cells, which serve as a representative model system for studying neuronal biological processes. We performed MS analysis by using both nano-LC-MALDI-MS/MS and nano-LC-ESI-MS/MS for maximal proteome coverage. Of 1,482 non-redundant proteins semiquantitatively identified, 72 were differentially expressed with 39 up- and 33 down-regulated, including 64 novel nerve growth factor-responsive PC12 proteins. Gene ontology analysis of the differentially expressed proteins by MANGO indicated with statistical significance that the up-regulated proteins were mostly related to the biological processes of cell morphogenesis, apoptosis/survival, and cell differentiation. Some of the up-regulated proteins of unknown function, such as PAIRBP1, translationally controlled tumor protein, prothymosin alpha, and MAGED1, were further analyzed to validate their significant functions in neuronal differentiation by immunoblotting and immunocytochemistry using each antibody combined with a specific short interfering RNA technique. Knockdown of these proteins caused abnormal cell morphological changes, inhibition of neurite formation, and cell death during each course of the differentiation, confirming their important roles in neurite formation and survival of PC12 cells. These results show that our iTRAQ-MANGO-biological analysis framework, which integrates a number of standard proteomics strategies, is effective for targeting and elucidating the functions of proteins involved in the cellular biological process being studied.

Mineralocorticoid receptor blockade enhances the antiproteinuric effect of an angiotensin II blocker through inhibiting podocyte injury in type 2 diabetic rats.

Treatment with angiotensin II type 1 receptor blockers (ARBs) is the first-line therapy for hypertensive patients with diabetic nephropathy. However, emerging clinical evidence indicates that mineralocorticoid receptor (MR) blockers have blood pressure-independent antiproteinuric effects. We sought to determine whether treatment with an MR blocker, eplerenone, enhances the effects of an ARB, telmisartan, on podocyte injury and proteinuria in type 2 diabetic Otsuka-Long-Evans-Tokushima-Fatty (OLETF) rats. From 20 to 50 weeks old, diabetic OLETF rats showed higher systolic blood pressure (SBP) and urinary protein excretion (U(protein)V) than nondiabetic control Long-Evans-Tokushima-Otsuka rats. At 50 weeks old, OLETF rats also showed glomerular sclerosis and podocyte injury, whereas nephrin and podocin mRNA levels in isolated glomeruli were significantly decreased. Treatment with telmisartan (3 mg/kg/day p.o.) decreased SBP and U(protein)V, increased nephrin and podocin mRNA levels, and attenuated glomerular sclerosis and podocyte injury. Eplerenone (100 mg/kg/day p.o.) did not alter SBP but elicited similar changes in renal parameters. However, greater reductions in U(protein)V and podocyte injury and greater increases in nephrin and podocin mRNA levels were observed in the combination treatment group. Hydralazine (25 mg/kg/day p.o.) decreased SBP but did not alter any renal parameters. These data indicate that MR blockade enhances the SBP-independent antiproteinuric effect of an ARB through inhibiting podocyte injury in type 2 diabetic rats.