IKKγ Facilitates the Activation of NF-κB by Hepatitis C Virus Core Protein

Hepatitis C virus (HCV) is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV core protein has been shown to modulate various cellular signaling pathways including the nuclear factor κB (NF-κB) pathway which is associated with inflammation, cell proliferation and apoptosis. However, there have been conflicting reports about the effect of HCV core protein on NF-κB pathway, and the mechanism by which the core protein affects NF-κB activity remains nuclear. In this study, the functional interaction of HCV core protein and IκB kinase γ (IKKγ) was investigated using the expression plasmids of core and the components of IKK complex. The data revealed that HCV core protein activates NF-κB. Also, HCV core protein up-regulated the phosphorylation and degradation of IκBα. The activating effect of HCV core protein on NF-κB was synergistically elevated by IKKγ. It was noticed that the N-terminal IKKβ binding site, C-terminal leucine zipper, and zinc finger domains of IKKγ are not necessary for its synergistic effect. HCV core protein and IKKγ appeared to activate NF-κB by up-regulating the IKKβ activity resulting in the degradation of IκBα. As expected, HCV core protein induced the expression of NF-κB-targeted pro-inflammatory genes such as iNOS, IL-1β and IL-6 in the transcription level. These results suggest that HCV core protein induces NF-κB through the interaction with IKKγ and may play a critical role in the development of inflammation and related liver diseases.

Low Non-NMDA Receptor Current Density as Possible Protection Mechanism from Neurotoxicity of Circulating Glutamate on Subfornical Organ Neurons in Rats

The subfornical organ (SFO) is one of circumventricular organs characterized by the lack of a normal blood brain barrier. The SFO neurons are exposed to circulating glutamate (60~100 microM), which may cause excitotoxicity in the central nervous system. However, it remains unclear how SFO neurons are protected from excitotoxicity caused by circulating glutamate. In this study, we compared the glutamate-induced whole cell currents in SFO neurons to those in hippocampal CA1 neurons using the patch clamp technique in brain slice. Glutamate (100 microM) induced an inward current in both SFO and hippocampal CA1 neurons. The density of glutamate-induced current in SFO neurons was significantly smaller than that in hippocampal CA1 neurons (0.55 vs. 2.07 pA/pF, p0.05). These results demonstrate that glutamate-mediated action through non-NMDA glutamate receptors in SFO neurons is smaller than that of hippocampal CA1 neurons, suggesting a possible protection mechanism from excitotoxicity by circulating glutamate in SFO neurons.

Direct Corticosteroid Modulation of GABAergic Neurons in the Anterior Hypothalamic Area of GAD65-eGFP Mice

Corticosterone is known to modulate GABAergic synaptic transmission in the hypothalamic paraventricular nucleus. However, the underlying receptor mechanisms are largely unknown. In the anterior hypothalamic area (AHA), the sympathoinhibitory center that project GABAergic neurons onto the PVN, we examined the expression of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) of GABAergic neurons using intact GAD65-eGFP transgenic mice, and the effects of corticosterone on the burst firing using adrenalectomized transgenic mice. GR or MR immunoreactivity was detected from the subpopulations of GABAergic neurons in the AHA. The AHA GABAergic neurons expressed mRNA of GR (42%), MR (38%) or both (8%). In addition, in brain slices incubated with corticosterone together with RU486 (MR-dominant group), the proportion of neurons showing a burst firing pattern was significantly higher than those in the slices incubated with vehicle, corticosterone, or corticosterone with spironolactone (GR-dominant group; 64 vs. 11~14%, p<0.01 by chi2-test). Taken together, the results show that the corticosteroid receptors are expressed on the GABAergic neurons in the AHA, and can mediate the corticosteroid-induced plasticity in the firing pattern of these neurons. This study newly provides the experimental evidence for the direct glucocorticoid modulation of GABAergic neurons in the AHA in the vicinity of the PVN.

Effects of alprazolam on capture stress-related serum cortisol responses in Korean raccoon dogs (Nyctereutes procyonoides koreensis)

The purpose of this study was to evaluate the effect of alprazolam on the stress that Korean raccoon dogs (Nyctereutes procyonoides koreensis) may experience while caught in a live trap by measuring their serum cortisol response. The animals were placed in a live trap with or without being pretreated with oral doses of alprazolam. In both groups, pre-trap blood samples were initially collected without anesthesia before the animals were positioned in the live trap; then post-trap blood samples were collected after the animals had remained in the live trap for 2 h. Changes in cortisol levels were observed using a chemiluminescent immunoassay. The level of cortisol increased in the control group and decreased in the alprazolam-pretreatment group (p < 0.05). In this study, we demonstrated that alprazolam pretreatment reduced stress during live trap capture.

Dendrotoxin-kappa suppresses tumor growth induced by human lung adenocarcinoma A549 cells in nude mice

Voltage-gated K+ (Kv) channels have been considered to be a regulator of membrane potential and neuronal excitability. Recently, accumulated evidence has indicated that several Kv channel subtypes contribute to the control of cell proliferation in various types of cells and are worth noting as potential emerging molecular targets of cancer therapy. In the present study, we investigated the effects of the Kv1.1-specific blocker, dendrotoxin-kappa (DTX-kappa), on tumor formation induced by the human lung adenocarcinoma cell line A549 in a xenograft model. Kv1.1 mRNA and protein was expressed in A549 cells and the blockade of Kv1.1 by DTX-kappa, reduced tumor formation in nude mice. Furthermore, treatment with DTX-kappa significantly increased protein expression of p21Waf1/Cip1, p27Kip1, and p15INK4B and significantly decreased protein expression of cyclin D3 in tumor tissues compared to the control. These results suggest that DTX-kappa has anti-tumor effects in A549 cells through the pathway governing G1-S transition.

Expression of iNOS and NADPH-diaphroase Reactivity in the Lipopolysaccharide Treated Rat Kidney / 대한해부학회지

Inducible nitric oxide synthase (iNOS) has been known to be involved in the various physiological metabolim and has been attracting topic. However, there are extensive differences in the reports about the localization of iNOS expression. To resolve this discrepancy, we compared immunohistochemical data from four iNOS antibody produced by different company (Chemicon, CH; Sigma, SI; Transduction Laboratories, TL; Upstate, UP), and NADPHdiaphorase (NADPH-d) enzyme-histochemical results using light- and transmission electorn-microscope in the lipopolysaccharide (LPS)-treated rat kidney. Electron microscopical examination revealed two different distribution of the NADPH-d reaction product. In the majority of NADPH-d reaction-positive cells, reaction depositions were restricted to the mitochondia, and in the cells of macula densa, descending thin limb (DTL), capsular epithelium (CE) and interstitial wandering cells (WC), NADPH-d positivities were found in the cytoplasm. In immunohistochemical results from LPStreated animal, DTL, CE and WC were positively stained with TL and UP antibodies but with CH and SI antibodies. We conclude that NADPH-d histochemistry may be usefull for identifing the iNOS-positive cells morphologically.

Infrared spectroscopy characterization of normal and lung cancer cells originated from epithelium

The vibrational spectral differences of normal and lung cancer cells were studied for the development of effective cancer cell screening by means of attenuated total reflection infrared spectroscopy. The phosphate monoester symmetric stretching nus(PO3(2-)) band intensity at ~970 cm-1 and the phosphodiester symmetric stretching nus(PO2-) band intensity at ~1,085 cm-1 in nucleic acids and phospholipids appeared to be significantly strengthened in lung cancer cells with respect to the other vibrational bands compared to normal cells. This finding suggests that more extensive phosphorylation occur in cancer cells. These results demonstrate that lung cancer cells may be prescreened using infrared spectroscopy tools.

Organotypic slice culture of the hypothalamic paraventricular nucleus of rat

Organotypic slice cultures have been developed as an alternative to acute brain slices because the neuronal viability and synaptic connectivity in these cultures can be preserved well for a prolonged period of time. This study evaluated a stationary organotypic slice culture developed for the hypothalamic paraventricular nucleus (PVN) of rat. The results showed that the slice cultures maintain the typical shape of the nucleus, the immunocytochemical signals for oxytocin, vasopressin, and corticotropin-releasing hormone, and the electrophysiological properties of PVN neurons for up to 3 weeks in vitro. The PVN neurons in the culture expressed the green fluorescent protein gene that had been delivered by the adenoviral vectors. The results indicate that the cultured slices preserve the properties of the PVN neurons, and can be used in longterm studies on these neurons in vitro.

Management of Metastatic Thyroid Papillary Carcinoma with Radioiodine in a Patient with Chronic Renal Failure on Hemodialysis / 대한신장학회잡지

Metastatic thyroid papillaty carcinoma was diagnosed in a 54-year-old woman. The cancer had present in many lymph nodes. After her surgical procedure, she was advised to have radioiodine treatment. However, the patient had chronic renal failure and was on hemodialysis. We tried radioiodine therapy of usual dose for remove of residual tumor burden. Hemodialysis treatments of 4hours and 2 hours performed each 24 and 48 hours after the administration of 131I resulted in a 66% and 80% reduction in total body radiation levels. All contaminated wastes were disposed of by the hospital's department of radiation safety. Postdialysis monitoring revealed no residual radiation contamination of dialysis machines or radiation exposure to the dialysis staff. It is needed more experiences about dose of radioiodine and timing, blood flow rate and duration of hemodialysis.

Expression of ATP-sensitive potassium channel and sulfonylurea receptor in neonate and adult rat tissues

The ATP-sensitive potassium (KATP) channel is a member of inward rectifier potassium channel (Kir) that is inhibited by intracellular ATP and functions in close relation to sulfonylurea receptors (SUR). Although the molecular mechanism and physiological function of KATP channels are well understood, the expression pattern during development or treatment with the channel modulators such as glybenclamide is little known. In this work, we determined mRNA levels of a KATP channel (Kir6.2) and a sulfonylurea receptor (SUR2) in rat tissues by RNase protection assay. Levels of Kir6.2 and SUR2 mRNA in the rat brain and skeletal muscle were higher in adult (90-120 days) than in neonate (2-8 days), whereas those in the heart were not much different between neonate (2-8 days) and adult (90-120 days). In addition, none of KATP channel modulators (opener, pinacidil and nicorandil; blocker, glybenclamide) affected the Kir6.2 mRNA levels in the heart, brain and skeletal muscle. The results indicate that the expression of Kir and SUR genes can vary age-dependently, but the expression of Kir is not dependent on the long-term treatment of channel modulators. The effect of the channel modulators on mRNA level of SUR is remained to be studied further.