Involvement of Elf3 on Smad3 activation-dependent injuries in podocytes and excretion of urinary exosome in diabetic nephropathy.

Diabetic nephropathy (DN) is among the most serious complications of diabetes mellitus, and often leads to end-stage renal disease ultimately requiring dialysis or renal transplantation. The loss of podocytes has been reported to have a role in the onset and progression of DN. Here, we addressed the activation mechanism of Smad3 signaling in podocytes. Expression of RII and activation of Smad3 were induced by AGE exposure (P<0.05). Reduction of the activation of RII-Smad3 signaling ameliorated podocyte injuries in Smad3-knockout diabetic mice. The bone morphogenetic protein 4 (BMP4) significantly regulated activation of RII-Smad3 signalings (P<0.05). Moreover, the epithelium-specific transcription factor, Elf3was induced by AGE stimulation and, subsequently, upregulated RII expression in cultured podocytes. Induction of Elf3 and activation of RII-Smad3 signaling, leading to a decrease in WT1 expression, were observed in podocytes in diabetic human kidneys. Moreover, AGE treatment induced the secretion of Elf3-containing exosomes from cultured podocytes, which was dependent on the activation of the TGF-ß-Smad3 signaling pathway. In addition, exosomal Elf3 protein in urine could be measured only in urinary exosomes from patients with DN. The appearance of urinary exosomal Elf3 protein in patients with DN suggested the existence of irreversible injuries in podocytes. The rate of decline in the estimated Glomerular Filtration Rate (eGFR) after measurement of urinary exosomal Elf3 protein levels in patients with DN (R2 = 0.7259) might be useful as an early non-invasive marker for podocyte injuries in DN.

Urinary Exosomal mRNA of WT1 as Diagnostic and Prognostic Biomarker for Diabetic Nephropathy.

Diabetic nephropathy (DN) is the major cause of end-stage renal failure and is associated with increased morbidity and mortality as compared to other causes of renal disease. Albuminuria is often the first clinical indicator of the presence of DN. However, albuminuria or proteinuria is a common symptom in patients with various renal disorders. Therefore, specific biomarkers for the diagnosis of DN are required. A primary hallmark of DN is the progressive damage and death of glomerular podocytes, resulting in the leaking of proteins into the urine. Urinary exosomes released by podocytes are microvesicles containing information of the originated cells. Podocyte-derived signal transduction factors (PDSTFs) are good candidates to assess podocyte injuries. The profile of PDSTFs in urinary exosomes from patients with DN is different from that from patients with minimal change nehrotic syndrome. In addition, PDSTFs molecules in exosomes were derived from primary murine podocytes under high glucose conditions. Among PDSTFs in urinary exosomes, Wilms tumor 1 (WT1) levels reflected damage of diabetic glomeruli in the patients. Urinary exosomal WT1 can predict the decline in eGFR for the following several years. In conclusion, urinary exosomal WT1 is a useful biomarker to improve risk stratification in patients with DN. J. Med. Invest. 65:208-215, August, 2018.

Progressive renal insufficiency related to ALK inhibitor, alectinib.

Alectinib is a second generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor and is generally effective and tolerated in patients who have demonstrated disease progression or adverse effects while on the first generation inhibitor, crizotinib. ALK inhibitors can cause a reversible chronic increase of serum creatinine concentration; however, they rarely induce progressive renal insufficiency. We herein report a case of a 68-year-old woman diagnosed with ALK-positive advanced non-small cell lung cancer and who received ALK inhibitors. Due to dysgeusia and transaminitis, her medication was switched from crizotinib to alectinib. Rapid progressive glomerulonephritis developed 1 year after the initiation of alectinib treatment. A renal biopsy revealed unique kidney lesions in both tubules and glomeruli. Glucocorticoid therapy partially reversed kidney impairment. However, re-administration of alectinib caused kidney dysfunction, which was improved by the cessation of alectinib. Our case suggests that much attention should be paid to kidney function when using ALK inhibitors.

Successful treatment of highly advanced immunoglobulin G4-related kidney disease presenting renal mass-like regions with end-stage kidney failure: a case study.

BACKGROUND: Immunoglobulin G4-related kidney disease characterized by immunoglobulin G4-positive plasma cell-rich tubulointerstitial nephritis has distinctive serological and radiological findings. Renal prognosis is good because of a good response to glucocorticoids. Here we report a case of successful treatment of highly advanced immunoglobulin G4-related kidney disease presenting renal mass-like regions with end-stage kidney failure. CASE PRESENTATION: A 59-year-old Japanese man was referred to our hospital because of uremia with a creatinine level of 12.36 mg/dL. Urinalysis revealed mild proteinuria and hyperß2microglobulinuria, and blood tests showed hyperglobulinemia with an IgG level of 3243 mg/dL and an IgG4 level of 621 mg/dL. Non-contrast computed tomography revealed renal mass-like regions. Based on the findings, immunoglobulin G4-related kidney disease was suspected, however, further radiological examination showed unexpected results. Ga-67 scintigraphy showed no kidney uptake. T2-weighted magnetic resonance imaging revealed high-intensity signals which corresponded to mass-like regions and multiple patchy low-intensity signals in kidney cortex. Finally, the patient was diagnosed with immunoglobulin G4-related kidney disease by renal pathology of severe immunoglobulin G4-positive plasma cell-rich tubulointerstitial nephritis and characteristic fibrosis. He received 50 mg oral prednisolone, which was tapered with a subsequent decrease of serum creatinine and IgG4 levels. One year after initiation of treatment, he achieved normalization of serum IgG4 level and proteinuria, and remained off dialysis with a creatinine level of 3.50 mg/dL. After treatment with steroids, repeat imaging suggested bilateral severe focal atrophy. However, mass-like regions did not show atrophic change although renal atrophy was evident in patchy low-intensity lesions on T2-weighted magnetic resonance imaging. These findings suggest that multiple patchy low-intensity signals and high-intensity mass-like regions were mildly atrophic lesions of immunoglobulin G4-related kidney disease due to severe fibrosis and normal parts of kidney, respectively. CONCLUSIONS: In immunoglobulin G4-related kidney disease with severe kidney failure, radiological findings should be carefully examined. In addition, renal prognosis may be good despite highly advanced tubulointerstitial nephritis and fibrosis.

Re-recognition of Age-dependent Reference Range for the Serum Creatinine Level in Teenagers - A Case of Slowly Progressive Tubulointerstitial Nephritis which Occurred in an Adolescent.

For the first time, a 15-year-old boy was found to have a slight degree of proteinuria and microscopic hematuria during annual school urinalysis screening. His kidney function had already severely deteriorated. A kidney biopsy revealed tubulointerstitial nephritis (TIN) with diffuse inflammatory cell infiltration. His medical records showed his serum creatinine level to be 0.98 mg/dL two years ago, which was abnormally high considering his age. Although the etiology of slowly progressive TIN was unclear, glucocorticoid and immunosuppressant therapy improved his kidney function. This case report suggests that all doctors should recognize the reference range for the serum creatinine level in teenagers.

A case of rapid amelioration of hepatitis C virus-associated cryoglobulinemic membranoproliferative glomerulonephritis treated by interferon-free directly acting antivirals for HCV in the absence of immunosuppressant.

Mixed cryoglobulinemic syndrome, which is a systemic vasculitis characterized by the immune complex deposition in small- and medium-sized arteries and most often due to chronic hepatitis C virus (HCV) infection, sometimes clinically manifests as refractory glomerulonephritis or nephritic syndrome. Patients with mixed cryoglobulinemic nephropathy who have a rapidly progressive glomerulonephritis should receive immunosuppressive therapy. After disease stabilization, patients should receive concurrent therapy for the underlying HCV infection. The standard therapy of a chronic HCV infection is IFN monotherapy or IFN combined with ribavirin; however, after the introduction of direct-acting antivirals (DAAs), the standard therapy for patients with HCV genotype 1 has dramatically changed. We report a case of HCV-associated cryoglobulinemic membranoproliferative glomerulonephritis (MPGN) successfully treated by daclatasvir and asunaprevir, which are IFN-free DAAs for HCV, in combination with angiotensin II receptor blocker without immunosuppressive therapy. The patient developed severe nephrotic syndrome with progressive kidney dysfunction. Blood examination revealed a high copy number of HCV-RNA (6.4 log IU/mL, type 1), cryoglobulinemia, paraproteinemia of IgM-κ, and hypocomplementemia. Histological analysis showed MPGN type 1. These findings were compatible with those observed in HCV-associated cryoglobulinemic MPGN. This case offers original evidence for the application of newer generation of IFN-free DAAs in the treatment of HCV-associated cryoglobulinemic nephropathy.

Influential factors on serum albumin concentration in hospitalized chronic kidney disease patients.

BACKGROUND: Serum albumin concentration (SAC) is a prognostic factor that is affected by many factors such as postural change, liver function and food intake. Chronic kidney disease (CKD) patients excrete proteinuria, have low-protein diet, and receive glucocorticoid therapy. No one has evaluated the most influential factors on SAC in CKD patients. METHODS: A retrospective study. Hospitalized CKD patients with less than 1 g/gCreatinine proteinuria receiving glucocorticoid therapy (n=28), with 1 or more g/gCreatinine proteinuria not receiving glucocorticoid therapy (n=36), and with 1 or more g/gCreatinine proteinuria receiving glucocorticoid therapy (n=39) were enrolled. SAC, hemoglobin, proteinuria and blood pressure at the last outpatient check-up before hospitalization, on the second day of hospitalization, at the last laboratory examination before discharge, as well as at the first outpatient follow-up after discharge were analyzed. RESULTS: SAC decreased on the second day of hospitalization and increased at the first outpatient follow-up significantly in all groups. Unexpectedly, the change of SAC was irrelevant to the amount of proteinuria. CONCLUSIONS: SAC was affected by not only proteinuria, but also postural change, physical activity, and food in CKD patients. SAC should be analyzed by standardizing a patient's condition during phlebotomy. J. Med. Invest. 64: 146-152, February, 2017.

Re-evaluation of Pre-pump Arterial Pressure to Avoid Inadequate Dialysis and Hemolysis: Importance of Prepump Arterial Pressure Monitoring in Hemodialysis Patients.

Prepump arterial pressure (PreAP) is monitored to avoid generating excessive negative pressure. The National Kidney Foundation K/DOQI clinical practice guidelines for vascular access recommend that PreAP should not fall below -250 mm Hg because excessive negative PreAP can lead to a decrease in the delivery of blood flow, inadequate dialysis, and hemolysis. Nonetheless, these recommendations are consistently disregarded in clinical practice and pressure sensors are often removed from the dialysis circuit. Thus far, delivered blood flow has been reported to decrease at values more negative than -150 mm Hg of PreAP. These values have been analyzed by an ultrasonic flowmeter and not directly measured. Furthermore, no known group has evaluated whether PreAP-induced hemolysis occurs at a particular threshold. Therefore, the aim of this study was to clarify the importance of PreAP in the prediction of inadequate dialysis and hemolysis. By using different diameter needles, human blood samples from healthy volunteers were circulated in a closed dialysis circuit. The relationship between PreAP and delivered blood flow or PreAP and hemolysis was investigated. We also investigated the optimal value for PreAP using several empirical monitoring methods, such as a pressure pillow. Our investigation indicated that PreAP is a critical factor in the determination of delivered blood flow and hemolysis, both of which occured at pressure values more negative than -150 mm Hg. With the exception of direct pressure monitoring, commonly used monitoring methods for PreAP were determined to be ineffective. We propose that the use of a vacuum monitor would permit regular measurement of PreAP.

Effects of adiponectin on growth and differentiation of human keratinocytes--implication of impaired wound healing in diabetes.

Impaired wound healing is one of the most common complications associated with diabetes. Adiponectin is an abundant circulating adipocyte-derived cytokine that has beneficial effects on disorders accompanying diabetes. Herein we report that adiponectin has a regulatory effect on the growth and differentiation of HaCaT human keratinocyte cells. Furthermore, adiponectin regulated the expression of TGFbeta isoforms in keratinocytes in a dose-dependent manner, which implies that adiponectin modulates other types of cells related to wound repair via secretion of growth factors from keratinocytes. Moreover, TUNEL assay results revealed that adiponectin enhances apoptosis of keratinocytes. Taken together, the present results indicate that adiponectin has suppressive effects on the formation of hyperkeratosis commonly seen in patients with diabetic foot and its application may be beneficial for developing treatment for that disorder.