Curcuma sp.-derived dehydrocurdione induces heme oxygenase-1 through a Michael reaction between its α, ß-unsaturated carbonyl and Keap1.

To elucidate the anti-inflammatory mechanism of Curcuma sp., we investigated whether dehydrocurdione, a sesquiterpene contained in Curcuma sp., induces heme oxygenase (HO)-1, an antioxidative enzyme, in RAW 264.7 macrophages. Dehydrocurdione was extracted from the rhizome of Curcuma sp., and its purity was verified by high performance liquid chromatography. Treatment with 10-100 µM dehydrocurdione transiently and concentration-dependently increased HO-1 mRNA and protein levels. Docking simulation suggested the presence of the Michael reaction between dehydrocurdione and Kelch-like ECH-associated protein (Keap)1 keeping nuclear factor-erythroid2-related-factor (Nrf)2, a transcription factor, in the cytoplasm. Nrf2 that was definitely free from Keap1 was detected in the nuclei after dehydrocurdione treatment. Subsequently, the HO-1 E2 enhancer, a target of Nrf2, was activated, resulting in HO-1 expression. Also, an investigation using 6-shogaol and 6-gingerol supported the concept that the α, ß-unsaturated carbonyl structure plays an important role in the interaction with Keap1. Dehydrocurdione suppressed lipopolysaccharide-induced NO release, a marker of inflammation. Clarification of the HO-1 synthesis increase mechanism revealed in this study will help contribute to the development of novel phytotherapeutic strategies against inflammation-associated diseases.

Minimal change nephrotic syndrome and prohibitin-2 gene polymorphism.

BACKGROUND: Patients with minimal change nephrotic syndrome (MCNS) often also have allergic diseases. Abnormalities of Th2-derived cytokines and T-cell functions contribute to development of these diseases. On the other hand, imbalances between reactive oxygen species (ROS) and antioxidants have been implicated in MCNS and progression of atopic dermatitis. ROS, produced mainly within mitochondria, subject cells to oxidative stress, while prohibitin 2 protects mitochondria by increasing tolerance to ROS. Additionally, podocin, a member of the slit diaphragm protein complex, contains PHB-like domain that serves as a signaling platform regulating podocyte function through associated transmembrane proteins. PATIENTS AND METHOD: Then, we performed exome sequencing analysis in five patients with frequently relapsing their MCNS associated with allergic disease and serum IgE concentrations of 2000 IU/L or higher. RESULTS: We detected a heterozygous prohibitin 2 polymorphism, c.873-3_873-2 delCA (rs111523336), in 1 patient. This mutation in exon 9 caused frameshifts in regions connected to splicing sites, where they could disrupt transcription of prohibitin 2. Frequency of this polymorphism in exon 9 is 7.3% among Japanese. Increase in peripheral blood ROS even MCNS remission state suggests the heterozygous prohibitin 2 variant may contribute to give more susceptibility towards the recurrence of MCNS as well as atopic skin disease. This increase may have progression of atopic dermatitis, which sometimes heralded. CONCLUSION: The prohibitin-2 polymorphism may reduce ROS tolerance in glomerular epithelium and led to high local exposure to ROS, increasing permeability of the glomerular basement membrane to result in proteinuria. Imbalance between ROS and antioxidants together with failure of signal transduction in the glomerular slit membrane caused by prohibitin 2 abnormality could have contributed to nephrotic syndrome in our patients. Prohibitin 2 analysis is needed in additional MCNS patients with concomitant allergic disease.

Heterozygous p.S811F RET gene mutation associated with renal agenesis, oligomeganephronia and total colonic aganglionosis: a case report.

BACKGROUND: Several shared common gene networks participate in development of interstinal ganglia and also nephron formation; the glial cell line-derived neurotrophic factor/Ret/glial cell line-derived neurotrophic factor receptor gene network is particularly important. CASE PRESENTATION: We encountered a patient with total colonic aganglionosis as well as right renal agenesis and oligomeganephronia. Gene analysis in this patient disclosed a heterozygous p.S811F mutation was in Ret gene exon 14, resulting in a substitution of phenylalanine for serine. The large side chain of phenylalanine obstructed the opening of the hydrophobic pocket of the Ret molecule causing interference with its interaction with adenosine triphosphate and consequent marked reduction in its enzyme activity. This could account for our patient's severe intestinal disease and renal dysplasia. We know of no previous reports of concomitant Hirschsprung's disease and oligomeganephronia. CONCLUSIONS: The patient's overall illness could be considered a novel Ret gene mutation syndrome.

Clinical and genetic characteristics of Japanese nephronophthisis patients.

BACKGROUND: Nephronophthisis (NPH) accounts for 4-5 % of end-stage renal disease occurring in childhood. METHOD: We investigated the clinical context and characteristics of renal and extrarenal symptoms, as well as the NPHP genes, in 35 Japanese patients with clinical and histologic features suggesting NPH. RESULTS: NPH occurred fairly uniformly throughout Japan irrespective of region or gender. In three families, NPH affected siblings. The median age of patients was 12.5 years. Renal abnormalities attributable to NPH discovered through mass screening, such as urine tests in school. However, NPH accounted for less than 50 % of children with abnormal findings, including incidentally discovered renal dysfunction during evaluation of extrarenal symptoms or during routine check-ups. Typical extrarenal manifestations leaded to discovery including anemia and delayed physical development. The urine often showed low gravity specific density and low molecular weight proteinuria. Frequent renal histologic findings included cystic dilation of tubules, mainly in the medulla, and irregularity of tubular basement membranes. Genetically abnormalities of NPHP1 were not common, with large deletions frequently noted. Compound heterozygotes showing single abnormalities in each of NPHP1, NPHP3, and NPHP4 were observed. CONCLUSIONS: Our findings resemble those reported in Western populations.

Tubulointerstitial nephritis complicating IVIG therapy for X-linked agammaglobulinemia.

BACKGROUND: Patients with X-linked agammaglobulinemia (XLA) develop immune-complex induced diseases such as nephropathy only rarely, presumably because their immunoglobulin (Ig) G concentration is low. We encountered a patient with XLA who developed tubulointerstitial nephritis during treatment with intravenous immunoglobulin (IVIG). CASE PRESENTATION: A 20-year-old man was diagnosed with XLA 3 months after birth and subsequently received periodic γ-globulin replacement therapy. Renal dysfunction developed at 19 years of age in association with high urinary ß2-microglobulin (MG) concentrations. A renal biopsy specimen showed dense CD3-positive lymphocytic infiltration in the tubulointerstitium and tubular atrophy, while no IgG4-bearing cell infiltration was found. Fibrosclerosis and crescent formation were evident in some glomeruli. Fluorescent antibody staining demonstrated deposition of IgG and complement component C3 in tubular basement membranes. After pulse steroid therapy was initiated, urinary ß2-MG and serum creatinine concentrations improved. CONCLUSION: Neither drug reactions nor collagen disease were likely causes of tubular interstitial disorder in this patient. Although BK virus was ruled out, IgG in the γ-globulin preparation might have reacted with a pathogen present in the patient to form low-molecular-weight immune complexes that were deposited in the tubular basement membrane.

Childhood Cogan syndrome with aortitis and anti-neutrophil cytoplasmic antibody-associated glomerulonephritis.

Cogan syndrome is a systemic disease manifesting interstitial keratitis, sensorineural hearing loss, tinnitus, and rotatory vertigo. Renal complications of this syndrome are very rare. We encountered an adolescent with Cogan syndrome complicated by aortitis and anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis. At the age of 14, the patient showed proteinuria in a screening urinalysis at school and was found to lack a right radial pulse. Magnetic resonance angiography disclosed right subclavian artery stenosis. Examination of a renal biopsy specimen showed ANCA-positive crescentic glomerulonephritis. Steroid and immunosuppressant treatment improved renal function and histopathology, but repeated recurrences followed. At 18, the patient developed rotatory vertigo, a sense of ear fullness, and sensorineural hearing loss. The patient was diagnosed with Cogan syndrome. We know of no previous description of ANCA-positive crescentic glomerulonephritis in children with Cogan syndrome. Accordingly, evaluation of aortitis in childhood should include not only otolaryngologic and ophthalmologic examinations, but also periodic urine examination and renal function tests.

A novel OCRL1 mutation in a patient with the mild phenotype of Lowe syndrome.

Oculocerebrorenal syndrome of Lowe (OCRL, OMIM 309000), also known as Lowe syndrome, is a rare X-linked multisystem disorder characterized by congenital cataracts, mental retardation, and Fanconi syndrome of the kidney proximal tubules. Lowe syndrome is caused by mutations in the gene encoding a member of the inositol polyphosphate-5-phosphatase protein family (OCRL1) on chromosome Xq26.1. OCRL1 contains 24 exons and encodes a 105-kDa phosphatidylinositol (4,5) bisphosphate 5-phosphatase. An OCRL1 isoform generated by alternative splicing is predominantly expressed in brain, and localizes to the trans-Golgi network, lysosomes, and endosomes. Impaired inositol polyphosphate-5-phosphatase activity elevates phosphatidylinositol (4,5) bisphosphate levels that are required for vesicle trafficking within the Golgi apparatus, actin cytoskeleton remodeling closely associated with Golgi, and endosomal membrane trafficking. Accordingly, abnormalities in the actin cytoskeleton may influence the function of renal epithelial cells in patients with Lowe syndrome. OCRL1 mutations exist in about 95% of patients with Lowe syndrome, and new mutations occur in 32% affected males. We here describe a Japanese male with the mild phenotype of Lowe syndrome. Physical examination revealed mild congenital bilateral cataracts, mild mental disability, and short stature. Proteinuria was also mild with a high ß2-microglobulinuria level. Nucleotide sequence analysis identified a hemizygous mutation (T-to-C transition) at nucleotide 2039 in exon 18 that substitutes Ser (TCT) for Phe (TTT) at amino acid position 680. This missense mutation is located outside the known catalytic domain that is encoded by exons 4 through 15. The present patient carries a novel OCRL1 mutation that is helpful for genetic counseling.

Cyclosporin A may cause injury to undifferentiated glomeruli persisting in patients with Alport syndrome.

BACKGROUND/AIMS: Alport syndrome (AS) is a renal disorder caused by a genetic abnormality of type IV collagen α3 and α4, or α5 genes and shows a poor prognosis. Since the defect of type IV collagen synthesis disturbs the maturation process of the glomerular capillary loop, residual immature glomeruli persist after birth. The therapeutic efficacy of cyclosporin A (CyA) for AS patients seems to be controversial. We recently noted that renal specimens obtained from a child with AS who was treated with CyA and then developed CyA nephropathy included an increased number of undifferentiated embryonic-type glomeruli. METHODS: We analyzed renal histologic and immunohistologic findings in children with AS who did (n = 3) or did not (n = 2) develop CyA-induced nephropathy despite appropriately low serum CyA concentrations (<100 ng/mL) being maintained over a period of 2 years. To discriminate embryonic-type from mature glomeruli, staining for type IV collagen α1, laminin ß1, and laminin ß2 accompanied by light microscopic observation were employed. Staining patterns were used to semiquantitatively assess glomerular immaturity (glomerular immaturity index, or GII). RESULTS: In initial biopsy specimens, residual embryonic-type glomeruli were observed in each patient. Patients with early-onset CyA nephropathy had a high GII (median value 2.91 vs 1.23 ± 0.62 normal kidney tissues). In the follow-up biopsy after CyA treatment, surviving embryonic-type, collapsing embryonic-type, and sclerotic glomeruli that had failed to differentiate were observed. Taken together, the number of these glomeruli essentially equaled the total number of embryonic-type glomeruli in specimens obtained before CyA treatment. CONCLUSIONS: Our findings indicate a need for caution in CyA therapy for patients with AS, even for a relatively short course of administration, because some patients may have an unexpected number of embryonic-type glomeruli that predispose to CyA nephropathy.

Cure of relapsing nephrosis by an allogeneic marrow graft for chronic myelogenous leukemia.

BACKGROUND: Minimal-change nephrotic syndrome has recently been attributed to an immature, dysfunctional T-cell population. CASE-DIAGNOSIS/TREATMENT: A woman, now 23 years old, developed nephrotic syndrome when she was 6 years old. Despite treatment with steroids and immunosuppressants such as cyclosporine, mizoribine, mycophenolate mofetil, and tacrolimus, the patient relapsed 14 times. At the age of 19 years, she developed chronic myelogenous leukemia, against which imatinib achieved cytogenetic remission. The patient received an allogeneic bone marrow graft transplantation from an unrelated marrow bank donor, with an uncomplicated recovery and molecular genetic remission. Immunosuppressants were withdrawn within 6 months. The patient is now without drug treatment. Complete remission of nephrotic syndrome has also been maintained for over 4 years without any drug administration. CONCLUSIONS: The patient's course supports suggestions that immunological dysfunction in nephrosis is associated with abnormality of immature, relatively unclassified T cells (CD34(+)) representing hematopoietic stem cells, as opposed to mature T cells (CD34(-)).

Effect and therapeutic mechanisms of tonsillectomy for childhood IgA nephropathy.

AIM: We investigated efficacy and therapeutic mechanisms of tonsillectomy for intractable childhood IgA nephropathy. Five patients refused tonsillectomy. Among 25 patients, 19 patients were able to evaluate histological findings before and after surgery. Patients with poor (n = 7) or relatively poor (n = 18) histologically determined prognosis and an age of at least 7 years, together with proteinuria of at least 0.3 g/day or severe persisting despite ongoing drug treatment, are candidates for surgery. Patients were grouped by interval between diagnosis of IgA nephropathy and tonsillectomy (within 3 years; early group vs 3 years or later; later group). Patients underwent kidney biopsy shortly before and 1 to 2 years after tonsillectomy. RESULTS: Proteinuria was reduced after tonsillectomy over 2 years of follow-up in both early and later groups compared with proteinuria in the 6 months preceding surgery. Complete remission was achieved in 10 patients, most often among those having surgery within 3 years, while patients refusing surgery failed to attain complete remission of urinary findings. Histological activity decreased in both groups, significantly when surgery was early. Complement component C3 deposition and activated macrophages in glomeruli decreased after tonsillectomy, especially with early surgery. CONCLUSION: Tonsillectomy improved clinicopathological features in relatively severe paediatric IgA nephropathy, especially with the early-surgery group. Therapeutic mechanisms may include inhibition of complement activity in glomeruli and glomerular infiltration by activated macrophages.

Nonfunction of the ECT2 gene may cause renal tubulointerstitial injury leading to focal segmental glomerulosclerosis.

BACKGROUND: Secondary focal segmental glomerulosclerosis (FSGS) follows congenital or acquired tubulointerstitial alterations such as in Dent's disease, Lowe syndrome, and reflux nephropathy. Failure of adequate regeneration after tubulointerstitial injury, or abnormal tubulogenesis, can disturb intrarenal blood circulation, causing excessive glomerular filtration. The epithelial cell-transforming sequence 2 gene (ECT2) contributes to tight junction function in epithelial cells. METHODS: We encountered two patients with a nonfunctioning ECT2 genotype who later developed FSGS. Both developed proteinuria associated with acute renal failure in early childhood. RESULTS: Renal biopsy specimens showed marked tubulointerstitial nephritis at the onset of proteinuria, later progressing to FSGS consequent to tubulointerstitial injury. The patients did not respond to corticosteroids and attained only incomplete remission upon cyclosporine A administration. One patient received a maternal renal transplant with good function and no rejection. CONCLUSIONS: ECT2 is important for tight junction function and maintenance of cell polarity. Nonfunction of this gene may cause renal tubulointerstitial injury, progressing to glomerular sclerosis.

Pediatric left renal vein entrapment syndrome diagnosed by 99mTc-albumin-conjugate scintigraphy.

BACKGROUND/AIMS: Procedures for diagnosis of left renal vein entrapment syndrome (LRVES) in children have been either invasive or limited in accuracy. We examined scintigraphy with (99m)Tc-diethylene triamine pentaacetic acid-conjugated human serum albumin ((99m)Tc-HSA-D) scintigraphy in childhood LRVES, demonstrating selective left renal nuclides excretion. We also measured peak velocity using pulse Doppler ultrasonography, calculating pressure differences between inferior vena cava and left renal vein using a simplified Bernoulli equation. METHODS: Thirteen patients provisionally diagnosed with LRVES by ultrasonography combined with other imaging such as magnetic resonance angiography and three-dimensional computer tomography (CT) were examined. RESULTS: Four children showing repeated gross hematuria all showed pressure differences exceeding 3.0 mm Hg. Selective left renal albumin excretion was demonstrated by (99m)Tc-HSA-D scintigraphy. Single-photon emission CT also showed accumulation in a site consistent with the left renal pelvis. Among 9 children manifesting mainly orthostatic proteinuria, selective left renal albumin excretion examined by (99m)Tc-HSA-D scintigraphy was demonstrated only in those with proteinuria exceeding 1 g/g Cr after standing in a lordotic position. Pressure differences in patients with orthostatic proteinuria were unrelated to proteinuria severity. CONCLUSIONS: Combining pulse Doppler ultrasonography with (99m)Tc-HSA-D scintigraphy, both noninvasive and safe in children, may suffice for diagnosis of LRVES, especially with gross hematuria.