Calpain-mediated proteolysis of polycystin-1 C-terminus induces JAK2 and ERK signal alterations.

Autosomal dominant polycystic kidney disease (ADPKD), a hereditary renal disease caused by mutations in PKD1 (85%) or PKD2 (15%), is characterized by the development of gradually enlarging multiple renal cysts and progressive renal failure. Polycystin-1 (PC1), PKD1 gene product, is an integral membrane glycoprotein which regulates a number of different biological processes including cell proliferation, apoptosis, cell polarity, and tubulogenesis. PC1 is a target of various proteolytic cleavages and proteosomal degradations, but its role in intracellular signaling pathways remains poorly understood. Herein, we demonstrated that PC1 is a novel substrate for µ- and m-calpains, which are calcium-dependent cysteine proteases. Overexpression of PC1 altered both Janus-activated kinase 2 (JAK2) and extracellular signal-regulated kinase (ERK) signals, which were independently regulated by calpain-mediated PC1 degradation. They suggest that the PC1 function on JAK2 and ERK signaling pathways might be regulated by calpains in response to the changes in intracellular calcium concentration.

Increased urinary Angiotensinogen/Creatinine (AGT/Cr) ratio may be associated with reduced renal function in autosomal dominant polycystic kidney disease patients.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary kidney diseases that frequently result in renal failure. In this cross-sectional observational cohort study, we evaluated urinary angiotensinogen (AGT) as a potential biomarker to assess renal function in ADPKD. METHODS: Urinary AGT was measured in 233 ADPKD patients and its association with estimated glomerular filtration rate (eGFR) and height-adjusted total kidney volume (htTKV) were evaluated. The localization of AGT and other renin-angiotensin system (RAS)-related molecules were identified using immunohistochemistry in human ADPKD tissues. RESULTS: Baseline urinary AGT/Cr was negatively correlated with CKD-EPI eGFR (r(2) = 0.162, P < 0.001) and positively correlated with htTKV (r(2) = 0.107, P < 0.001). Both urinary AGT/Cr and plasma renin activity levels were significantly elevated in hypertensive ADPKD patients. Among hypertensive subjects, urinary AGT/Cr was significantly increased in the advanced CKD stages (III-V) compared to early CKD stages (I-II) (28.6 ± 60.3 vs. 93.2 ± 139.3 µg/g, P < 0.001). Immunohistochemical study showed strong expression of AGT along the cyst-lining epithelial cells as well as the nearby compressed tubular epithelial cells. CONCLUSIONS: Our results suggested that urinary AGT/Cr may be a valuable biomarker for renal damage in ADPKD since intrarenal ischemic insults induced by cyst growth and subsequent intrarenal RAS activation may play a potential role in the development of hypertension and renal dysfunction in ADPKD.

Hyperuricemia and deterioration of renal function in autosomal dominant polycystic kidney disease.

BACKGROUND: The role of hyperuricemia in disease progression of autosomal dominant polycystic kidney disease (ADPKD) has not been defined well. We investigated the association of serum uric acid (sUA) with renal function and the effect of hypouricemic treatment on the rate of renal function decline. METHODS: This is a single-center, retrospective, observational cohort study. A total of 365 patients with ADPKD who had estimated glomerular filtration rate (eGFR) ≥ 15 mL/min/1.73 m2 and who were followed up for > 1 year were included in our analysis. Hyperuricemia was defined by a sUA level of ≥ 7.0 mg/dL in male and ≥ 6.0 mg/dL in female or when hypouricemic medications were prescribed. RESULTS: Hyperuricemia was associated with reduced initial eGFR, independent of age, sex, hypertension, albuminuria, and total kidney volume. During a median follow-up period of over 6 years, patients with hyperuricemia showed a faster annual decline in eGFR (-6.3% per year vs. -0.9% per year, p = 0.008). However, after adjusting for age, sex, hypertension and initial eGFR, sUA was no longer associated with either annual eGFR decline or the development of ESRD. Among 53 patients who received hypouricemic treatment, the annual eGFR decline appeared to be attenuated after hypouricemic treatment (pretreatment vs. posttreatment: -5.3 ± 8. 2 vs. 0.2 ± 6.2 mL/min/1.73 m2 per year, p = 0.001 by Wilcoxon signed-rank test). CONCLUSIONS: Although hyperuricemia was associated with reduced eGFR, it was not an independent factor for renal progression in ADPKD. However, the correction of hyperuricemia may attenuate renal function decline in some patients with mild renal insufficiency.

Urinary N-acetyl-ß-D glucosaminidase as a surrogate marker for renal function in autosomal dominant polycystic kidney disease: 1 year prospective cohort study.

BACKGROUND: Renal failure is one of the most serious complications associated with autosomal dominant polycystic kidney disease (ADPKD). To date, early markers have failed to predict renal function deterioration at the early stages. This 1-year prospective study evaluated N-acetyl-ß-D-glucosaminidase (NAG) as a new surrogate marker for renal function in ADPKD. METHODS: A total of 270 patients were enrolled in the study, and we measured urinary NAG, ß2-microglobulin, neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) prospectively for 1 year to compare their predictive values for renal function. RESULTS: Baseline urinary NAG/Cr was negatively correlated with estimated glomerular filtration rate (GFR) (r2 = 0.153, P < 0.001) and positively correlated with total kidney volume (TKV) (r2 = 0.113, P < 0.001). Among other biomarkers, urinary NAG/Cr better discriminated patients with decreased renal function from those with conserved renal function, showing the largest area under the curve (AUC 0.794). Immunohistochemical study revealed strong staining along the cyst-lining epithelial cells as well as the nearby compressed tubular epithelial cells. However, both single and repeated measurements of urinary NAG/Cr failed to predict renal function decline in 1 year. CONCLUSIONS: Urinary NAG/Cr may be a useful surrogate marker for renal function in ADPKD patients.

The effect of essential oils of dietary wormwood (Artemisia princeps), with and without added vitamin E, on oxidative stress and some genes involved in cholesterol metabolism.

Wormwood (Artemisia princeps) due to the abundance of antioxidant in its essential oils (EO), has been used as a traditional drug and health food in Korea. Oxidative stress plays an important role in the etiology of atherosclerosis thus antioxidative chemicals improves hepatic lipid metabolism partly by reducing oxysterol formation. The antioxidant activity was assessed using two methods, human low-density lipoprotein (LDL) oxidation and the anti-DPPH free radical assays. It was found that the antioxidant activity of EO with vitamin E higher than EO alone. To study mechanisms accounting for the antiatherosclerotic properties of this wormwood EO, we examined the expression of key genes in cholesterol metabolism such as the LDL receptor, the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and sterol regulatory element binding proteins. The induction was increased up to twofold at 0.05 mg/mL of EO treatment in HepG2 cells for 24h. When EO (0.2 mg/mL) was co-incubated with vitamin E, interestingly, the LDL receptor was dramatically induced by 5-6-folds. HMG-CoA reductase did not change. However, treatment with the higher concentration resulted in cytotoxicity. Our data suggest that wormwood EO with vitamin E may be anti-atherogenic due to their inhibition of LDL oxidation and upregulation of the LDL receptor.

Water-soluble genistin glycoside isoflavones up-regulate antioxidant metallothionein expression and scavenge free radicals.

Genistin has antioxidant activities; however, its insolubility in water often limits its biological availability in vivo. Using a novel transglycosylation process, the solubility of genistin glycosides was increased 1000 to 10000-fold, but it was not known whether these modified genistin glycosides maintained antioxidant activity. We found that both genistin and its glycosides similarly up-regulated the transcription of several metallothionein (MT) antioxidant genes (MT1A, MT2A, MT1E, and MT1X), as well as the glucose 6-phosphate dehydrogenase (G6PD) gene in HepG2 cells. This gene induction was mediated by the sequestration of zinc in the cytosol, which up-regulated the metal-responsive transcription factor-1 (MTF-1) that induced MT gene expression. Although not as effective as ascorbic acid, genistin glycosides possessed slightly greater reducing power than genistin. We concluded that genistin and genistin glycosides have a direct antioxidant effect and an indirect antioxidant effect, perhaps via induction of MT by activity of MTF-1.

[Prognostic factors and survival according to the Okuda stage in patients with hepatocellular carcinoma].

BACKGROUND/AIMS: There are several staging systems to decide the stage of hepatocellular carcinoma (HCC), but yet incomplete. Okuda stage which includes both tumor characteristics and liver function is widely used. The aims of this study were to assess the usefulness of known prognostic factors and Okuda staging system in 237 cases of HCC. METHODS: A retrospective analysis of 237 cases of HCC diagnosed from 2000 to 2002 was performed. We analyzed prognostic factors such as age, sex, liver cirrhosis, Child-Pugh classification, tumor size, albumin, bilirubin, alpha-FP, ascites, encephalopathy and Okuda stage. Prognostic analysis was performed for single variables and estimating survival distributions were analyzed by the Kaplan-Meier method, statistically compared by the log-rank test. RESULTS: Patients had a mean age of 57.5 years and were predominantly men (79.7%). Liver cirrhosis were noticed in 214 cases (90.3%). The overall median survival period was 25.7 months. The median survival period was correlated to bilirubin, ascites, alpha-FP, tumor size, and Child-Pugh classification, but not to age, sex, and pattern of viral infection. The median survival period of the Okuda stage I, II and III cases was 35.8, 11.9 and 8.5 months (p<0.001). CONCLUSIONS: The median survival period of patients with HCC is significantly correlated to Okuda staging system, and survival period has improved than the initial data when the Okuda staging system was published in 1985. However, in order to discriminate early staged HCC more accurately, other prognostic factors such as alpha-FP and tumor morphology should be included in future staging system for HCC.

Effects of furanocoumarins from apiaceous vegetables on the catalytic activity of recombinant human cytochrome P-450 1A2.

Inhibition of cytochrome P-450 1A2 (CYP1A2)-mediated activation of procarcinogens may be an important chemopreventive mechanism. Consumption of apiaceous vegetables (rich in furanocoumarins) inhibits CYP1A2 in humans. Because many furanocoumarins are potent inhibitors of several CYPs, we characterized the effects of three furanocoumarins from apiaceous vegetables on human CYP1A2 (hCYP1A2). We assessed hCYP1A2 methoxyresorufin O-demethylase (MROD) activity using microsomes from Saccharomyces cerevisiae expressing hCYP1A2. Isopimpinellin exhibited mechanism-based inactivation (MBI) of hCYP1A2 (K(i) = 1.2 µM, k (inact) = 0.34 min⁻¹, and partition ratio = 8). Imperatorin and trioxsalen were characterized as mixed inhibitors with K(i) values of 0.007 and 0.10 µM, respectively. These results indicate that even if present at low levels in apiaceous vegetables, imperatorin, trioxsalen and isopimpinellin may contribute significantly to CYP1A2 inhibition and potentially decreased procarcinogen activation. Moreover, the in vivo effect of isopimpinellin on CYP1A2 may be longer lasting compared to reversible inhibitors.

Therapeutic target achievement in type 2 diabetic patients after hyperglycemia, hypertension, dyslipidemia management.

BACKGROUND: Our study group established "3H care" in 2002. The meaning of "3H care" attain and maintain adequate controls over hypertension, hyperlipidemia, and hyperglycemia in type 2 diabetic patients. This study evaluated the achievement of target goals after one year or more of "3H care" by specialists in our diabetic clinic. METHODS: This was a retrospective study of 200 type 2 diabetic patients who received "3H care" for one year or more in our diabetic clinic. We evaluated achievement of target goals for metabolic controls as suggested by the American Diabetes Association. RESULTS: Overall, 200 type 2 diabetes patients were enrolled, of whom 106 were males (53%) and 94 were females (47%). After one year of "3H care," the mean HbA1c was 7.2±1.5% and the percentage of patients achieving glycemic control (HbA1c <7%) was 51.8%. However only 32.2% of hypertensive patients achieved the recommended target. After one year of "3H care," the percentages of those who achieved the target value for dyslipidemia were 80.0% for total cholesterol, 66.3% for low density lipoprotein cholesterol, 57.9% for triglyceride, and 51.8% for high density lipoprotein cholesterol. The percentage that achieved all three targets level was only 4.4% after one year and 14.8% after two years. CONCLUSION: The results of this study demonstrate that only a minor proportion of patients with type 2 diabetes achieved the recommended goals despite the implementation of "3H care." It is our suggestion that better treatment strategies and methods should be used to control hypertension, hyperlipidemia and hyperglycemia.

Diffuse alveolar hemorrhage associated with antineutrophil cytoplasmic antibody levels in a pregnant woman taking propylthiouracil.

Propylthiouracil (PTU) is known to be a potential cause of antineutrophil cytoplasmic antibody (ANCA) positive small vessel vasculitis, resulting in glomerulonephritis and diffuse alveolar hemorrhage (DAH). Herein, we describe a 25-year-old pregnant woman who developed a perinulcear ANCA (p-ANCA) and myeloperoxidase ANCA (MPO-ANCA) positive DAH during PTU therapy. The patient improved after corticosteroid therapy and discontinuation of the PTU. Methimazole was prescribed in spite of the risk of recurrence of DAH because of the pregnancy. The patient is currently free from pulmonary problems. Our case shows that the alternative agent, methimazole, can be used to treat hyperthyroidism in a pregnant patient with PTU associated DAH.