Overexpression of WNK1 in POMC-expressing neurons reduces weigh gain via WNK4-mediated degradation of Kir6.2.

"With no lysine" (WNK) kinases have been shown to regulate various ion transporters in various tissues, but studies on the function of WNK kinases in the brain have been limited. In this study, we discovered that WNK1 and WNK4 in POMC-expressing neuronal cells in WNK1 overexpressed transgenic mice (WNK1 TG) decrease appetite via degradation of Kir6.2. Weight gain after 20 weeks of age was delayed in WNK1 TG mice as a result of reduced food intake. Expression of WNK1 and proopiomelanocortin (POMC) was higher in POMC-expressing neurons in the hypothalamus of WNK1 TG mice than in WT mice. Immunostaining of serial sections of the hypothalamus revealed that POMC-expressing neurons were smaller in WNK1 TG mice than in WT mice. In addition, expression of Kir6.2 was significantly reduced in WNK1 TG mice. Overexpression and knockdown of WNK4 demonstrated that WNK4 regulates protein expression of Kir6.2 via protein-protein interaction. Accordingly, reduced age-dependent weight gain of WNK1 TG mice seems to be related with the decreased Kir6.2 expression via WNK1- and WNK4-regulated protein stability of Kir6.2.

Application of a drug-interaction detection method to the Korean National Health Insurance claims database.

Drug interactions (DIs) constitute a serious problem and are considered to contribute to 6-30% of all adverse events (AEs). The use of existing data, including claims data, is expected to be helpful in detecting unknown DIs by complementing conventional spontaneous reporting systems. In the present study, an 'Ω shrinkage measure' was applied to the Korean National Health claims database to test the potential of the claims database as a DI surveillance resource. A well-known DI between non-steroidal anti-inflammatory drugs (NSAIDs) and diuretics was analyzed using the model. International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) codes related to DIs were assigned to the AEs of the DIs: I50, I50.0, I50.1, I50.9, R60, R60.1, R60.9, and J81. An elevated occurrence of AEs versus the expected level was observed using a two-sided 95% lower credibility interval limit above zero, Ω025=0.245, which was the screening limit. The result was consistent with the actual DI between the two drugs. The finding indicates that the claims data have the potential to be used as a DI surveillance resource and that the Ω shrinkage measure may be a promising tool for detecting DIs in claims data.

Renal toxicity evaluation and comparison between visipaque (iodixanol) and hexabrix (ioxaglate) in patients with renal insufficiency undergoing coronary angiography: the RECOVER study: a randomized controlled trial.

OBJECTIVES: This study sought to compare the nephrotoxicity of iodixanol and ioxaglate in patients with renal impairment undergoing coronary angiography. BACKGROUND: Iodixanol, a nonionic, dimeric, iso-osmolar contrast medium (IOCM), may be less nephrotoxic than low-osmolar contrast media (LOCM) in high-risk patients. METHODS: In a prospective, randomized trial in 300 adults with creatinine clearance (CrCl) < or =60 ml/min, patients received either iodixanol or ioxaglate and underwent coronary angiography with or without percutaneous coronary intervention. The primary end point was the incidence of contrast-induced nephropathy (CIN) (an increase in serum creatinine [SCr] > or =25% or > or =0.5 mg/dl [> or =44.2 mumol/l]). The incidence of CIN in patients with severe renal impairment at baseline (CrCl <30 ml/min) or diabetes and in those receiving large doses (> or =140 ml) of contrast medium was also determined. RESULTS: The incidence of CIN was significantly lower with iodixanol (7.9%) than with ioxaglate (17.0%; p = 0.021), corresponding to an odds ratio (OR) of CIN of 0.415 (95% confidence interval [CI] 0.194 to 0.889) for iodixanol. The incidence of CIN was also significantly lower with iodixanol in patients with severe renal impairment (p = 0.023) or concomitant diabetes (p = 0.041), or in patients given > or =140 ml of contrast media (p = 0.038). Multivariate analysis identified use of ioxaglate (OR 2.65, 95% CI 1.11 to 6.33, p = 0.028), baseline SCr, mg/dl (OR 2.0, 95% CI 1.04 to 3.85, p = 0.038), and left ventricular ejection fraction, % (OR 0.97, 95% CI 0.94 to 0.99, p = 0.019) as independent risk factors for CIN. CONCLUSIONS: The IOCM iodixanol was significantly less nephrotoxic than ioxaglate, an ionic, dimeric LOCM. (The RECOVER Trial; http://clinicaltrials.gov; NCT00247325).