[Development of a High-School Students' Version of the Daily Conversation Scale with Classroom Teachers].

Objective　This study was intended to develop a "High-School Students' Version of the Daily Conversation Scale with Classroom Teachers" to measure the frequency of daily conversations between high-school students and their classroom teachers.Methods　The study consisted of Surveys I and II. Survey I was intended to validate the structural validity and reliability of the "High-School Students' Daily Conversation Scale with Classroom Teachers (Prototype Version)." It measured the frequency of high-school students' daily conversations with classroom teachers using the prototype scale and employed confirmatory factor analysis and item response theory to assess the factor measurement model and item performance, respectively. Internal consistency was evaluated using McDonald's ω (omega) reliability coefficient. Study II was intended to validate the prototype scale through hypothesis testing. The survey assessed daily conversation frequency, teacher support perception, depression/anxiety, and the teacher-student relationship. Two models were constructed: one predicting the impact of daily conversation frequency on support perception and depression/anxiety and the other predicting the impact on the teacher-student relationship. It was hypothesized that both models would fit well, with daily conversation frequency positively associated with support perception and relationship, and depression/anxiety negatively associated with support perception and relationship.Result　The sample analyzed in Survey I consisted of 1,394 students in grades 1-3. The results of confirmatory factor analysis, item response theory, and McDonald's omega reliability coefficient met the criteria. The sample for Survey II consisted of 1,688 students in grades 1-3. The results of the analysis supported the hypothesis.Conclusion　The results of this study suggest that the prototype version of the scale was conceptually unidimensional and that the difficulty level of each item was well-balanced, indicating the successful development of a "High-School Students' Version of the Daily Conversation Scale with Classroom Teachers." By using this scale and examining the effects of the frequency of daily conversation with homeroom teachers on the psychology and behavior of high-school students, we believe that it will be possible to contribute to an understanding of primary prevention measures that homeroom teachers can take to address mental health problems among their high-school students. We believe that this scale will contribute to future school health activities in the field of public health.

Difference in IgA1 O-glycosylation between IgA deposition donors and IgA nephropathy recipients.

IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis, and disease recurrence often occurs after transplantation. On the other hands, Asymptomatic IgA deposition (IgAD) is occasionally observed in donated kidney. It is recognized that IgAD does not progress to IgAN, but the mechanism has not demonstrated yet. In IgAN, aberrant IgA1 O-glycan structure in the hinge region (HR) of serum IgA is suggested as one of the most convincing key mediators. However, little is known about IgA1 O-glycan structure in IgAD patients. Herein, we investigated the prevalence of IgAD in living renal transplant donors in our cohort. IgAD was observed in 21(13.0%) among 161 renal transplant donors and have statistically significant blood relationship with IgAN recipients (28.6% in relatives vs. 9.8% in non-relatives, respectively; p = 0.0073). Next, we evaluated the IgA1 O-glycan structure of serum IgA from IgAN recipients (n = 26), IgAD donors (n = 17), and non-IgAD helthy donors (n = 27) using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). The numbers of GalNAc and Gal and the Gal/GalNAc ratio in the HR of the IgAN recipients had significantly lower comparing to the IgAD and non-IgAD healthy donors. The decreased Gal/GalNAc ratio in IgAN recipients means the increased ratio of galactose-deficient IgA1. To the best of our knowledge, this is the first report to compare the O-glycan structures in IgAN recipients and IgAD donors using MALDI-TOF MS. We concluded that IgAD was more common in IgAN related donors. Overall, decreased GalNAc and Gal contents in HR could play a material pathogenic role in IgAN.

VEGF-A Links Angiolymphoid Hyperplasia With Eosinophilia (ALHE) to THSD7A Membranous Nephropathy: A Report of 2 Cases.

Autoantibodies against thrombospondin type 1 domain-containing 7A (THSD7A) cause membranous nephropathy (MN); however, the mechanisms involved in THSD7A expression and immunization are uncertain. We present 2 cases of THSD7A-associated MN accompanied by angiolymphoid hyperplasia with eosinophilia (ALHE), a benign tumor characterized by proliferation of plump endothelial cells. Prednisolone therapy, but not surgical resection of ALHE tumors, successfully suppressed eosinophilia and proteinuria in both cases. Because ALHE is characterized by the proliferation of plump endothelial cells, we focused on the roles of vascular endothelial growth factor A (VEGF-A) in MN pathogenesis. We found that plump endothelial cells in ALHE modestly expressed THSD7A in both cases. We also found that eosinophils in ALHE expressed VEGF-A, which upregulated THSD7A expression, especially under T-helper type 2-prone conditions in cultured endothelial cells. Furthermore, double-positive cells for THSD7A and CD83 surrounded the proliferated small vessels. Our results suggest that VEGF-A-induced THSD7A expression outside the kidney may be important for MN pathogenesis.

Antioxidant role of autophagy in maintaining the integrity of glomerular capillaries.

Autophagy is a lysosomal degradation system by which cytosolic materials and damaged organelles are broken down into basic components. To explore the physiological role of autophagy in glomerular endothelial cells (GEnCs), we compared the autophagic flux among cells in the kidney under starvation. Inhibition of autophagy by chloroquine administration significantly increased the number of autophagosomes or autolysosomes in GEnCs and proximal tubular cells, but not in podocytes, suggesting that the GEnCs exhibit substantial autophagic activity. Next, we analyzed endothelial and hematopoietic cell-specific atg5-deficient mice (atg5-conditional KO [cKO] mice). Glomeruli of 4-wk-old atg5-cKO mice exhibited slightly distended capillary loops accompanied by an accumulation of reactive oxygen species (ROS). Glomeruli of 8-wk-old atg5-cKO mice showed a lobular pattern with thickening of the capillary loops and mesangial matrix expansion; however, the vasculature of other organs was preserved. The atg5-cKO mice died by 12 wk of age, presumably due to pancytopenia resulting from the defect in their hematopoietic lineages. Therefore, we subjected 4-wk atg5-cKO mice to irradiation followed by bone marrow transplantation from normal littermates. Transplanted mice recapitulated the glomerular phenotypes of the atg5-cKO mice with no obvious histological changes in other organs. Twelve-mo-old transplanted mice developed mesangiolysis and glomerulosclerosis with significant deterioration of kidney function. Administration of N-acetyl-l-cysteine, a ROS scavenger, to atg5-cKO mice rescued the glomerular phenotypes. These data suggest that endothelial autophagy protects glomeruli from oxidative stress and maintains the integrity of glomerular capillaries. Enhancing endothelial autophagy may provide a novel therapeutic approach to minimizing glomerular diseases.

Analysis of an ADTKD family with a novel frameshift mutation in MUC1 reveals characteristic features of mutant MUC1 protein.

BACKGROUND: Medullary cystic kidney disease Type 1 is an autosomal dominant tubulointerstitial kidney disease (ADTKD). Recently, mucin 1 (MUC1) was identified as a causal gene of medullary cystic kidney disease (ADTKD-MUC1). However, the MUC1 mutation was found to be a single cytosine insertion in a single copy of the GC-rich variable number of tandem repeats (VNTRs), which are very difficult to analyze by next-generation sequencing. To date, other mutations have not been detected in ADTKD-MUC1, and the mutant MUC1 protein has not been analyzed because of the difficulty of genetically modifying the VNTR sequence. METHODS: We conducted whole-exome analyses of an ADTKD family by next-generation sequencing. We also performed histopathological analyses of a renal biopsy from a pedigree family member. We constructed a mutant protein expression vector based on the patient genome sequence and characterized the nature of the mutant protein. RESULTS: We found a novel frameshift mutation before the VNTR in the MUC1 gene. The resulting mutant MUC1 protein had a very similar amino acid sequence and predicted 3D structure to the previously reported mutant protein. Notably, the recombinant mutant MUC1 protein was trapped in the cytoplasm and appeared to self-aggregate. The patient native mutant protein was also found in urine exosomes. CONCLUSIONS: This novel frameshift mutation in the MUC1 gene and consequent mutant protein may contribute to the future discovery of the pathophysiology of ADTKD-MUC1. The mutant MUC1 protein in urine exosomes may be used for non-DNA-related diagnosis.

Lipophagy maintains energy homeostasis in the kidney proximal tubule during prolonged starvation.

Macroautophagy/autophagy is a self-degradation process that combats starvation. Lipids are the main energy source in kidney proximal tubular cells (PTCs). During starvation, PTCs increase fatty acid (FA) uptake, form intracellular lipid droplets (LDs), and hydrolyze them for use. The involvement of autophagy in lipid metabolism in the kidney remains largely unknown. Here, we investigated the autophagy-mediated regulation of renal lipid metabolism during prolonged starvation using PTC-specific Atg5-deficient (atg5-TSKO) mice and an in vitro serum starvation model. Twenty-four h of starvation comparably induced LD formation in the PTCs of control and atg5-TSKO mice; however, additional 24 h of starvation reduced the number of LDs in control mice, whereas increases were observed in atg5-TSKO mice. Autophagic degradation of LDs (lipophagy) in PTCs was demonstrated by electron microscopic observation and biochemical analysis. In vitro pulse-chase assays demonstrated that lipophagy mobilizes FAs from LDs to mitochondria during starvation, whereas impaired LD degradation in autophagy-deficient PTCs led to decreased ATP production and subsequent cell death. In contrast to the in vitro assay, despite impaired LD degradation, kidney ATP content was preserved in 48-h starved atg5-TSKO mice, probably due to increased utilization of ketone bodies. This compensatory mechanism was accompanied by a higher plasma FGF21 (fibroblast growth factor 21) level and its expression in the PTCs; however, this was not essential for the production of ketone bodies in the liver during prolonged starvation. In conclusion, lipophagy combats prolonged starvation in PTCs to avoid cellular energy depletion.

Autophagy Inhibits the Accumulation of Advanced Glycation End Products by Promoting Lysosomal Biogenesis and Function in the Kidney Proximal Tubules.

Advanced glycation end products (AGEs) are involved in the progression of diabetic nephropathy. AGEs filtered by glomeruli or delivered from the circulation are endocytosed and degraded in the lysosomes of kidney proximal tubular epithelial cells (PTECs). Autophagy is a highly conserved degradation system that regulates intracellular homeostasis by engulfing cytoplasmic components. We have recently demonstrated that autophagic degradation of damaged lysosomes is indispensable for cellular homeostasis in some settings. In this study, we tested the hypothesis that autophagy could contribute to the degradation of AGEs in the diabetic kidney by modulating lysosomal biogenesis. Both a high-glucose and exogenous AGE overload gradually blunted autophagic flux in the cultured PTECs. AGE overload upregulated lysosomal biogenesis and function in vitro, which was inhibited in autophagy-deficient PTECs because of the impaired nuclear translocation of transcription factor EB. Consistently, streptozotocin-treated, PTEC-specific, autophagy-deficient mice failed to upregulate lysosomal biogenesis and exhibited the accumulation of AGEs in the glomeruli and renal vasculature as well as in the PTECs, along with worsened inflammation and fibrosis. These results indicate that autophagy contributes to the degradation of AGEs by the upregulation of lysosomal biogenesis and function in diabetic nephropathy. Strategies aimed at promoting lysosomal function hold promise for treating diabetic nephropathy.

High-Fat Diet-Induced Lysosomal Dysfunction and Impaired Autophagic Flux Contribute to Lipotoxicity in the Kidney.

Excessive fat intake contributes to the progression of metabolic diseases via cellular injury and inflammation, a process termed lipotoxicity. Here, we investigated the role of lysosomal dysfunction and impaired autophagic flux in the pathogenesis of lipotoxicity in the kidney. In mice, a high-fat diet (HFD) resulted in an accumulation of phospholipids in enlarged lysosomes within kidney proximal tubular cells (PTCs). In isolated PTCs treated with palmitic acid, autophagic degradation activity progressively stagnated in association with impaired lysosomal acidification and excessive lipid accumulation. Pulse-chase experiments revealed that the accumulated lipids originated from cellular membranes. In mice with induced PTC-specific ablation of autophagy, PTCs of HFD-mice exhibited greater accumulation of ubiquitin-positive protein aggregates normally removed by autophagy than did PTCs of mice fed a normal diet. Furthermore, HFD-mice had no capacity to augment autophagic activity upon another pathologic stress. Autophagy ablation also exaggerated HFD-induced mitochondrial dysfunction and inflammasome activation. Moreover, renal ischemia-reperfusion induced greater injury in HFD-mice than in mice fed a normal diet, and ablation of autophagy further exacerbated this effect. Finally, we detected similarly enhanced phospholipid accumulation in enlarged lysosomes and impaired autophagic flux in the kidneys of obese patients compared with nonobese patients. These findings provide key insights regarding the pathophysiology of lipotoxicity in the kidney and clues to a novel treatment for obesity-related kidney diseases.

Time-dependent dysregulation of autophagy: Implications in aging and mitochondrial homeostasis in the kidney proximal tubule.

Autophagy plays an essential role in cellular homeostasis through the quality control of proteins and organelles. Although a time-dependent decline in autophagic activity is believed to be involved in the aging process, the issue remains controversial. We previously demonstrated that autophagy maintains proximal tubular cell homeostasis and protects against kidney injury. Here, we extend that study and examine how autophagy is involved in kidney aging. Unexpectedly, the basal autophagic activity was higher in the aged kidney than that in young kidney; short-term cessation of autophagy in tamoxifen-inducible proximal tubule-specific autophagy-deficient mice increased the accumulation of SQSTM1/p62- and ubiquitin-positive aggregates in the aged kidney. By contrast, autophagic flux in response to metabolic stress was blunted with aging, as demonstrated by the observation that transgenic mice expressing a green fluorescent protein (GFP)-microtubule-associated protein 1 light chain 3B fusion construct, showed a drastic increase of GFP-positive puncta in response to starvation in young mice compared to a slight increase observed in aged mice. Finally, proximal tubule-specific autophagy-deficient mice at 24 mo of age exhibited a significant deterioration in kidney function and fibrosis concomitant with mitochondrial dysfunction as well as mitochondrial DNA abnormalities and nuclear DNA damage, all of which are hallmark characteristics of cellular senescence. These results suggest that age-dependent high basal autophagy plays a crucial role in counteracting kidney aging through mitochondrial quality control. Furthermore, a reduced capacity for upregulation of autophagic flux in response to metabolic stress may be associated with age-related kidney diseases.

Autophagic clearance of mitochondria in the kidney copes with metabolic acidosis.

Metabolic acidosis, a common complication of CKD, causes mitochondrial stress by undefined mechanisms. Selective autophagy of impaired mitochondria, called mitophagy, contributes toward maintaining cellular homeostasis in various settings. We hypothesized that mitophagy is involved in proximal tubular cell adaptations to chronic metabolic acidosis. In transgenic mice expressing green fluorescent protein-tagged microtubule-associated protein 1 light chain 3 (GFP-LC3), NH4Cl loading increased the number of GFP puncta exclusively in the proximal tubule. In vitro, culture in acidic medium produced similar results in proximal tubular cell lines stably expressing GFP-LC3 and facilitated the degradation of SQSTM1/p62 in wild-type cells, indicating enhanced autophagic flux. Upon acid loading, proximal tubule-specific autophagy-deficient (Atg5-deficient) mice displayed significantly reduced ammonium production and severe metabolic acidosis compared with wild-type mice. In vitro and in vivo, acid loading caused Atg5-deficient proximal tubular cells to exhibit reduced mitochondrial respiratory chain activity, reduced mitochondrial membrane potential, and fragmented morphology with marked swelling in mitochondria. GFP-LC3-tagged autophagosomes colocalized with ubiquitinated mitochondria in proximal tubular cells cultured in acidic medium, suggesting that metabolic acidosis induces mitophagy. Furthermore, restoration of Atg5-intact nuclei in Atg5-deficient proximal tubular cells increased mitochondrial membrane potential and ammoniagenesis. In conclusion, metabolic acidosis induces autophagy in proximal tubular cells, which is indispensable for maintaining proper mitochondrial functions including ammoniagenesis, and thus for adapted urinary acid excretion. Our results provide a rationale for the beneficial effect of alkali supplementation in CKD, a condition in which autophagy may be reduced, and suggest a new therapeutic option for acidosis by modulating autophagy.

Autophagy protects kidney proximal tubule epithelial cells from mitochondrial metabolic stress.

Chronic metabolic stress is related to diseases, whereas autophagy supplies nutrients by recycling the degradative products. Cyclosporin A (CsA), a frequently used immunosuppressant, induces metabolic stress via effects on mitochondrial respiration, and thereby, its chronic usage is often limited. Here we show that autophagy plays a protective role against CsA-induced metabolic stress in kidney proximal tubule epithelial cells. Autophagy deficiency leads to decreased mitochondrial membrane potential, which coincides with metabolic abnormalities as characterized by decreased levels of amino acids, increased tricarboxylic acid (TCA) ratio (the levels of intermediates of the latter part of the TCA cycle, over levels of intermediates in the earlier part), and decreased products of oxidative phosphorylation (ATP). In addition to the altered profile of amino acids, CsA decreased the hyperpolarization of mitochondria with the disturbance of mitochondrial energy metabolism in autophagy-competent cells, i.e., increased TCA ratio and worsening of the NAD(+)/NADH ratio, coupled with decreased energy status, which suggests that adaptation to CsA employs autophagy to supply electron donors from amino acids via intermediates of the latter part of the TCA cycle. The TCA ratio of autophagy-deficient cells was further worsened with decreased levels of amino acids in response to CsA, and, as a result, the deficiency of autophagy failed to adapt to the CsA-induced metabolic stress. Deterioration of the TCA ratio further worsened energy status. The CsA-induced metabolic stress also activated regulatory genes of metabolism and apoptotic signals, whose expressions were accelerated in autophagy-deficient cells. These data provide new perspectives on autophagy in conditions of chronic metabolic stress in disease.

Renal transplantations from parents to siblings with autosomal recessive Alport syndrome caused by a rearrangement in an intronic antisense Alu element in the COL4A3 gene led to different outcomes.

Two siblings with autosomal recessive Alport syndrome (ARAS) obtained renal transplants from their consanguineous parents. Their COL4A3 mRNA transcripts were disrupted by a 139 bp intronic sequence between exon 48 and 49, which was derived from an antisense Alu element in this intron. The new amino acid sequence from the cryptic exon was terminated by a stop codon at the 1511th codon, resulting in the loss of 76 % α3(IV)NC1. This is the first case report of kidney transplantations between ARAS-homozygous siblings and their heterozygous parents. The brother experienced acute rejection just after transplantation and post-transplantation anti-glomerular basement membrane (GBM) nephritis, whereas the sister has experienced no problems to date. The anti-GBM nephritis could have resulted from the acute rejection. The COL4A3 gene heterozygous mutated parents, who are possibly at risk for thin basement membrane disease, have maintained their renal functions without urinary abnormalities after renal transplantation to date.

[Clinical characteristics of adult-onset minimal change nephrotic syndrome in our hospital].

OBJECTIVE: Few findings are available regarding adult-onset minimal change nephrotic syndrome (MCNS) with respect to the disease course and complications, such as acute kidney injury (AKI). We therefore performed a retrospective review to characterize the clinical presentations, steroid responsiveness and complications of adult-onset MCNS patients in our hospital. PATIENTS AND METHODS: We retrospectively reviewed 40 cases of idiopathic adult-onset MCNS who had been investigated and treated at a single center. Patients between 18 and 50 years of age (Younger group) at the time of biopsy were compared with those older than 50 years (Older group) with regard to demographic data, clinical features and treatment outcome. RESULTS: Baseline characteristics of the 40 patients were: median age, 42 years (interquartile range: 28-63 years); male, 70%; mean (+/- standard deviation) systolic and diastolic blood pressures, 125 +/- 17 mmHg and 78 +/- 12 mmHg, respectively; estimated glomerular filtration rate (eGFR), 74 mL/min/1.73 m2 (range: 64-94 mL/min/1.73 m2); serum albumin, 1.8 +/- 0.3 g/dL; and urinary protein, 7.8 g/day (range: 3.9-10.4 g/day). All except for one patient received steroid pulse therapy. Time to complete response (CR) was 12 days (range: 8-21 days). Time to CR was significantly longer in the Older group (p = 0.011). The Late-responder group (time to CR > 2 weeks)was significantly older (p < 0.01), with a low eGFR (p < 0.001) and a higher prevalence of interstitial fibrosis in renal biopsy before the initiation of corticosteroid therapy (p < 0.05), compared with the Early-responder group. AKI was observed in 14 patients. Patients with an episode of AKI were significantly older (p = 0.005), with a lower eGFR (p < 0.002) and a higher prevalence of cellular casts (p < 0.05). At the follow-up, 19 patients (51%) had experienced relapses. The relapse rate was significantly lower in the Older group than in the Younger group (p < 0.05). CONCLUSION: The present study revealed that older patients had a longer period to CR and a higher risk of AKI at follow-up.

[Case of HIV-associated nephropathy accompanied by nephrotic syndrome and acute worsening of kidney function].

A previously healthy black man presented with acute kidney injury wtih nephrotic syndrome. His serum creatinine and albumin concentrations were 8.0 mg/dL and 0.4 g/dL, respectively. Renal ultrasound demonstrated an enlarged kidney with an extremely high echogenic cortex. Human immunodeficiency virus (HIV) was serologically positive, and kidney biopsy revealed a collapsing variant of focal segmental glomerulosclerosis with interstitial nephritis. He was diagnosed as having HIV-associated nephropathy (HIVAN). Although there have been only a few cases with characteristic HIVAN features in Japan, the number of patients with HIVAN who need dialysis treatment is relatively high globally, and is expected to increase even in Japan. The rapid clinical course of HIVAN, along with its characteristic histology and the direct pathogenesis of HIV on podocytes, is noteworthy. We described this case with reference to some recent findings.

Autophagy guards against cisplatin-induced acute kidney injury.

Autophagy is a highly conserved bulk protein degradation pathway involved in cellular homeostasis. Although emerging evidence indicates involvement of autophagy in various conditions, efforts to clarify the role of autophagy in renal tubules are beginning to be elucidated. In the present study, we examined the hypothesis that autophagy guards against acute kidney injury (AKI) by modulating several deteriorative pathways that lead to tubular cell death using a cisplatin-induced model of AKI. Cisplatin treatment of GFP-LC3 (green fluorescent protein-microtubule-associated protein 1 light chain 3) transgenic mice induced autophagy in kidney proximal tubules in a time-dependent manner. Proximal tubule-specific autophagy-deficient mice exhibited more severe cisplatin-induced AKI than did control mice, as assessed via kidney function and morphologic findings. In addition, cisplatin induced more severe DNA damage and p53 activation, concomitant with an increase in apoptotic cell number, and a massive accumulation of protein aggregates in autophagy-deficient proximal tubules. Cisplatin treatment significantly increased reactive oxygen species-producing damaged mitochondria in immortalized autophagy-deficient proximal tubular cells when compared with autophagy-retrieved control cells. In conclusion, autophagy guards kidney proximal tubules against AKI, possibly by alleviating DNA damage and reactive oxygen species production and by eliminating toxic protein aggregates. Enhancing autophagy may provide a novel therapeutic option to minimize AKI.

Gene polymorphisms contributing to hypertension in immunoglobulin A nephropathy.

BACKGROUND: Hypertension, which is affected by genetic and environmental factors, is one of the major risk factors for chronic kidney disease. Identification of the genetic factor contributing to hypertension in patients with chronic kidney disease may potentially refine a therapeutic strategy. METHODS: In the present multicenter cross-sectional study, 240 patients were eligible (aged 15-50 years with urinary protein ≥0.25 g/day) out of 429 patients who were diagnosed as having immunoglobulin (Ig) A nephropathy (IgAN) by renal biopsy between 1990 and 2005 and enrolled in our previous study, PREDICT-IgAN. The outcome was hypertension defined as ≥140 and/or ≥90 mmHg of systolic and diastolic blood pressure and/or use of antihypertensives at renal biopsy. We assessed associations between hypertension and 28 polymorphisms with the frequency of minor genotype ≥10% among 100 atherosclerosis-related polymorphisms using the Chi-squared test in dominant and recessive models. We identified polymorphisms associated with hypertension in multivariate logistic regression models. RESULTS: Baseline characteristics: hypertension 36.3%. Among 28 polymorphisms, the Chi-squared test revealed that CD14 (-159CC vs CT/TT, P = 0.03) and ACE (DD vs DI/II, P = 0.03) were significantly associated with hypertension after Bonferroni correction. Multivariate logistic regression models revealed that CD14 -159CC [vs CT/TT, odds ratio (OR) 3.58 (95% confidence interval (CI) 1.66-7.63)] and ACE DD [vs DI/II, OR 4.41 (95% CI 1.80-10.8), P = 0.001] were independently associated with hypertension. CONCLUSIONS: CD14 C-159T and ACE I/D contributed to hypertension in patients with IgAN.

A case of MPO-ANCA-positive polyarteritis nodosa complicated by exudative otitis media, mononeuritis multiplex, and acute renal failure.

In December 2008, a 69-year-old Japanese woman was admitted to the Department of Otorhinolaryngology because of hearing impairment due to bilateral exudative otitis media, and was discharged without complete recovery despite conventional treatment. Two weeks later, she was readmitted for worsened deafness, numbness, gait disturbance, and general fatigue. She was referred to our department for general investigation. On admission, laboratory examination revealed severe inflammatory signs and active nephritic urinary sediments. Cranial computed tomography (CT) revealed progressive exudative otitis media and sinusitis. Initially, Wegener's granulomatosis was suspected. Nasal cavity biopsy, however, showed no granuloma formation or vasculitis. Serology revealed high titer of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA), suggestive of microscopic polyangitis (MPA). However, contrast CT identified stenosis of a celiac artery, and renal biopsy showed tubulointerstitial changes with minor glomerular abnormalities. Therefore, polyarteritis nodosa (PAN) was suspected and treatment with intravenous methylprednisolone was initiated. However, a lacunar infarct developed followed by cerebral hemorrhage, and the patient died 19 days after readmission. Autopsy revealed fibrinoid necrosis, neutrophilic infiltration, and giant cell reaction in small to medium-sized arteries in multiple organs. These findings led to diagnosis of systemic vasculitis anatomically compatible with PAN. This was a rare case of a patient with MPO-ANCA-positive PAN who may have developed bilateral exudative otitis media and hearing loss as the initial manifestation of PAN.

Autophagy protects the proximal tubule from degeneration and acute ischemic injury.

Autophagy is a bulk protein degradation system that likely plays an important role in normal proximal tubule function and recovery from acute ischemic kidney injury. Using conditional Atg5 gene deletion to eliminate autophagy in the proximal tubule, we determined whether autophagy prevents accumulation of damaged proteins and organelles with aging and ischemic renal injury. Autophagy-deficient cells accumulated deformed mitochondria and cytoplasmic inclusions, leading to cellular hypertrophy and eventual degeneration not observed in wildtype controls. In autophagy-deficient mice, I/R injury increased proximal tubule cell apoptosis with accumulation of p62 and ubiquitin positive cytoplasmic inclusions. Compared with control animals, autophagy-deficient mice exhibited significantly greater elevations in serum urea nitrogen and creatinine. These data suggest that autophagy maintains proximal tubule cell homeostasis and protects against ischemic injury. Enhancing autophagy may provide a novel therapeutic approach to minimize acute kidney injury and slow CKD progression.