14-3-3 proteins regulate cullin 7-mediated Eag1 degradation.

BACKGROUND: Mutations in the human gene encoding the neuron-specific Eag1 (KV10.1; KCNH1) potassium channel are linked to congenital neurodevelopmental diseases. Disease-causing mutant Eag1 channels manifest aberrant gating function and defective protein homeostasis. Both the E3 ubiquitin ligase cullin 7 (Cul7) and the small acid protein 14-3-3 serve as binding partners of Eag1. Cul7 mediates proteasomal and lysosomal degradation of Eag1 protein, whereas over-expression of 14-3-3 notably reduces Eag1 channel activity. It remains unclear whether 14-3-3 may also contribute to Eag1 protein homeostasis. RESULTS: In human cell line and native rat neurons, disruptions of endogenous 14-3-3 function with the peptide inhibitor difopein or specific RNA interference up-regulated Eag1 protein level in a transcription-independent manner. Difopein hindered Eag1 protein ubiquitination at the endoplasmic reticulum and the plasma membrane, effectively promoting the stability of both immature and mature Eag1 proteins. Suppression of endogenous 14-3-3 function also reduced excitotoxicity-associated Eag1 degradation in neurons. Difopein diminished Cul7-mediated Eag1 degradation, and Cul7 knock-down abolished the effect of difopein on Eag1. Inhibition of endogenous 14-3-3 function substantially perturbed the interaction of Eag1 with Cul7. Further structural analyses suggested that the intracellular Per-Arnt-Sim (PAS) domain and cyclic nucleotide-binding homology domain (CNBHD) of Eag1 are essential for the regulatory effect of 14-3-3 proteins. Significantly, suppression of endogenous 14-3-3 function reduced Cul7-mediated degradation of disease-associated Eag1 mutant proteins. CONCLUSION: Overall these results highlight a chaperone-like role of endogenous 14-3-3 proteins in regulating Eag1 protein homeostasis, as well as a therapeutic potential of 14-3-3 modulators in correcting defective protein expression of disease-causing Eag1 mutants.

FJU-C28 inhibits the endotoxin-induced pro-inflammatory cytokines expression via suppressing JNK, p38 MAPK and NF-κB signaling pathways.

Despite marked improvements in supportive care, the mortality rate of acute respiratory distress syndrome due to the excessive inflammatory response caused by direct or indirect lung injury induced by viral or bacterial infection is still high. In this study, we explored the anti-inflammatory effect of FJU-C28, a new 2-pyridone-based synthetic compound, on lipopolysaccharide (LPS)-induced inflammation in vitro and in vivo models. FJU-C28 suppressed the LPS-induced mRNA and protein expression of iNOS, COX2 and proinflammatory cytokines. The cytokine protein array results showed that LPS stimulation enhanced the secretion of IL-10, IL-6, GCSF, Eotaxin, TNFα, IL-17, IL-1ß, Leptin, sTNF RII, and RANTES. Conversely, the LPS-induced secretion of RANTES, TIMP1, IL-6, and IL-10 was dramatically suppressed by FJU-C28. FJU-C28 suppressed the LPS-induced expression of RANTES, but its parental compound FJU-C4 was unable to diminish RANTES in cell culture media or cell lysates. FJU-C28 blocked the secretion of IL-6 and RANTES in LPS-activated macrophages by regulating the activation of JNK, p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB). FJU-C28 prevented the LPS-induced decreases in lung function including vital capacity (VC), lung compliance (C chord), forced expiratory volume at 100 ms (FEV100), and forced vital capacity (FVC) in mice with LPS-induced systemic inflammatory responses. FJU-C28 also reduced neutrophil infiltration in the interstitium, lung damage and circulating levels of IL-6 and RANTES in mice with systemic inflammation. In conclusion, these findings suggest that FJU-C28 possesses anti-inflammatory activities to prevent endotoxin-induced lung function decrease and lung damages by down-regulating proinflammatory cytokines including IL-6 and RANTES via suppressing the JNK, p38 MAPK and NF-κB signaling pathways.

Identification of MKRN1 as a second E3 ligase for Eag1 potassium channels reveals regulation via differential degradation.

Mutations in the human gene encoding the neuron-specific Eag1 voltage-gated K+ channel are associated with neurodevelopmental diseases, indicating an important role of Eag1 during brain development. A disease-causing Eag1 mutation is linked to decreased protein stability that involves enhanced protein degradation by the E3 ubiquitin ligase cullin 7 (CUL7). The general mechanisms governing protein homeostasis of plasma membrane- and endoplasmic reticulum (ER)-localized Eag1 K+ channels, however, remain unclear. By using yeast two-hybrid screening, we identified another E3 ubiquitin ligase, makorin ring finger protein 1 (MKRN1), as a novel binding partner primarily interacting with the carboxyl-terminal region of Eag1. MKRN1 mainly interacts with ER-localized immature core-glycosylated, as well as nascent nonglycosylated, Eag1 proteins. MKRN1 promotes polyubiquitination and ER-associated proteasomal degradation of immature Eag1 proteins. Although both CUL7 and MKRN1 contribute to ER quality control of immature core-glycosylated Eag1 proteins, MKRN1, but not CUL7, associates with and promotes degradation of nascent, nonglycosylated Eag1 proteins at the ER. In direct contrast to the role of CUL7 in regulating both ER and peripheral quality controls of Eag1, MKRN1 is exclusively responsible for the early stage of Eag1 maturation at the ER. We further demonstrated that both CUL7 and MKRN1 contribute to protein quality control of additional disease-causing Eag1 mutants associated with defective protein homeostasis. Our data suggest that the presence of this dual ubiquitination system differentially maintains Eag1 protein homeostasis and may ensure efficient removal of disease-associated misfolded Eag1 mutant channels.

Trait mindfulness and depressive symptoms in non-small cell lung cancer patients: the mediating roles of quality of life and meaning in life.

OBJECTIVE: The present study examined the potential mediating influences of meaning in life and quality of life in the relationship of trait mindfulness and depressive symptoms in lung cancer patients. Design: We adopted a cross-sectional design studying a sample of patients with non-small cell lung cancer, aged 20-65 years, and receiving cancer treatments or follow-up care. Main Outcome Measures: The outcome measures included Beck Depression Inventory-II, European Organisation for Research and Treatment of Cancer Core Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and lung cancer specific complementary measure (EORTC QLQ-LC13), Five Facet Mindfulness Questionnaire, and the meaning in life questionnaire. Results: Among 116 lung cancer patients, 26.72% of them had clinically significant depressive symptoms. The presence of meaning, quality of life (QOL) functioning and symptom distress mediated the relationship of trait mindfulness and depressive symptoms. Multiple mediation analyses found that the presence of meaning in life was the main mediator. Conclusion: The reductions of depressive symptoms might be related to trait mindfulness enhancing lung cancer patients' perceptions of meaning in life. A mindfulness program has the potential to improve depressive symptoms in people with lung cancer.

The changes of quality of life and their correlations with psychosocial factors following surgery among women with breast cancer from the post-surgery to post-treatment survivorship.

OBJECTIVES: This 14-month study aimed to examine the changes of quality of life following breast cancer surgery and associations of such changes with depression and anxiety levels, and protective factors (attachment styles in close relationship, and meaning in life) based on positive psychology theory. MATERIALS AND METHODS: Women with breast cancer were recruited within one week of completion of breast cancer surgery. They were asked to complete several questionnaires to measure the generic and breast cancer specific quality of life, depression and anxiety levels, attachment styles in close relationship, and meaning in life. Assessments were performed at baseline (T0), T1 (the 2nd month), T2 (the 5th month), T3 (the 8th month), and T4 (the 14th month). RESULTS: While the generic functions of quality of life improve after surgery, no significant changes of the breast-specific functions were found during the 14-month follow up period. While physical, role, and social functions improved immediately after surgery, the improvements of emotional and cognitive functions began to occur at the 5th and the 8th months after surgery. Depressive symptoms predicted almost all general and breast-specific QOL functions and symptoms. Avoidant and anxious attachment styles were associated with the negative scores for breast-specific functions and symptoms. CONCLUSION: Breast-specific functions, in particular body image and sexual function, remain unchanged with the passage of time following surgery. A psychological rehabilitation program aiming to reduce depressive symptoms and enhance secure attachment styles in close relationships needs to be established immediately following surgery and continue through the post-treatment survivorship stages.

The Emerging Role of Nutritional Vitamin D in Secondary Hyperparathyroidism in CKD.

In chronic kidney disease (CKD), hyperphosphatemia induces fibroblast growth factor-23 (FGF-23) expression that disturbs renal 1,25-dihydroxy vitamin D (1,25D) synthesis; thereby increasing parathyroid hormone (PTH) production. FGF-23 acts on the parathyroid gland (PTG) to increase 1α-hydroxylase activity and results in increase intra-gland 1,25D production that attenuates PTH secretion efficiently if sufficient 25D are available. Interesting, calcimimetics can further increase PTG 1α-hydroxylase activity that emphasizes the demand for nutritional vitamin D (NVD) under high PTH status. In addition, the changes in hydroxylase enzyme activity highlight the greater parathyroid 25-hydroxyvitmain D (25D) requirement in secondary hyperparathyroidism (SHPT); the higher proportion of oxyphil cells as hyperplastic parathyroid progression; lower cytosolic vitamin D binding protein (DBP) content in the oxyphil cell; and calcitriol promote vitamin D degradation are all possible reasons supports nutritional vitamin D (NVD; e.g., Cholecalciferol) supplement is crucial in SHPT. Clinically, NVD can effectively restore serum 25D concentration and prevent the further increase in PTH level. Therefore, NVD might have the benefit of alleviating the development of SHPT in early CKD and further lowering PTH in moderate to severe SHPT in dialysis patients.

Antofine suppresses endotoxin-induced inflammation and metabolic disorder via AMP-activated protein kinase.

The inhibition of activated macrophages has been used to develop anti-inflammatory agents for therapeutic intervention to human diseases that cause excessive inflammatory responses. Antofine, a phenanthroindolizidine alkaloid, has a potent anti-inflammatory effect. However, the molecular mechanisms of its anti-inflammatory activity have not yet been fully detailed. In this study, we comprehensively explored the anti-inflammatory effects of antofine on endotoxin-induced inflammation in macrophages using cDNA microarray analysis, thereby elucidating the potential mechanism by which antofine suppresses inflammation. Antofine significantly suppressed the secretion of proinflammatory cytokines such as TNFα and IL-1ß and the production of iNOS in LPS-activated Raw264.7 macrophage cells. In addition, antofine can suppress the expressions of several inflammation-related genes (such as ARG-1, IL1F9, IL-10, and IL-33) and extracellular matrix genes (such as TNC and HYAL1), as well as a vasopressor gene (EDN1) in activated macrophage cells, that are induced by LPS stimulation. The gene expression profiles analyzed by GeneMANIA software showed that antofine not only contributed anti-inflammatory activity but also modulated the cellular metabolism via AMPK. Furthermore, antofine also modulated the activation of AMPK and caspase-1, the key regulator in inflammasome-mediated IL-1ß maturation, in activated macrophage cells. In conclusion, these data indicated that antofine potentially can not only contribute an anti-inflammatory effect but can also attenuate the metabolic disorders induced by inflammation via AMPK.

A longitudinal study of diurnal cortisol patterns and associated factors in breast cancer patients from the transition stage of the end of active cancer treatment to post-treatment survivorship.

OBJECTIVES: The aim of this study was to examine the changes in diurnal cortisol patterns and its associated factors among breast cancer patients over a 14-month follow up period. MATERIALS AND METHODS: A total of 85 breast cancer patients were recruited to participate in this study. Assessments were performed at baseline (T0), T1 (the 2nd month), T2 (the 5th month), T3 (the 8th month), and T4 (the 14th month). Salivary cortisol was measured and the following questionnaires were administered: BDI-II depression scale, European Organization for Research and Treatment of Cancer Core Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its breast cancer-specific complementary measure (EORTC QLQ-BR23). Patients were grouped into flat and steep groups, according to the median of the diurnal cortisol slopes at the time of the transition period. RESULTS: Breast cancer patients in the flatter slope group at transition period demonstrated steeper slopes over the course of recovery from treatment and those in the steeper slope group at transition period continued with steeper slopes over the course of recovery. The greater breast cancer-related symptoms (side-effects, symptoms relating to breast and arm, and hair loss) were associated with the changes in flatter diurnal cortisol slopes during14-month follow up period. CONCLUSION: Diurnal cortisol patterns in flatter slope group at the transition period appear to have a trend of recovery with the passage of time over the course of recovery from treatment. Management of breast cancer symptoms could improve dysregulation of diurnal cortisol patterns among survivors.

Cullin 7 mediates proteasomal and lysosomal degradations of rat Eag1 potassium channels.

Mammalian Eag1 (Kv10.1) potassium (K+) channels are widely expressed in the brain. Several mutations in the gene encoding human Eag1 K+ channel have been associated with congenital neurodevelopmental anomalies. Currently very little is known about the molecules mediating protein synthesis and degradation of Eag1 channels. Herein we aim to ascertain the protein degradation mechanism of rat Eag1 (rEag1). We identified cullin 7 (Cul7), a member of the cullin-based E3 ubiquitin ligase family, as a novel rEag1 binding partner. Immunoprecipitation analyses confirmed the interaction between Cul7 and rEag1 in heterologous cells and neuronal tissues. Cul7 and rEag1 also exhibited significant co-localization at synaptic regions in neurons. Over-expression of Cul7 led to reduced protein level, enhanced ubiquitination, accelerated protein turn-over, and decreased current density of rEag1 channels. We provided further biochemical and morphological evidence suggesting that Cul7 targeted endoplasmic reticulum (ER)- and plasma membrane-localized rEag1 to the proteasome and the lysosome, respectively, for protein degradation. Cul7 also contributed to protein degradation of a disease-associated rEag1 mutant. Together, these results indicate that Cul7 mediates both proteasomal and lysosomal degradations of rEag1. Our findings provide a novel insight to the mechanisms underlying ER and peripheral protein quality controls of Eag1 channels.

Effects of hydrocortisone on activation of inflammation via interleukin-33 in ventilator-induced lung injury.

Despite mechanical ventilation being a very important life-saving intervention, ventilator-induced lung injury (VILI) is related with inflammatory effects and causes high mortality. Our previous study demonstrated that the interleukin-33 (IL-33) cytokine pathway is a biomarker of VILI. The purpose of this study was to further explore the effects of hydrocortisone sodium succinate (HC) on pro-inflammatory IL-33 activation by VILI. The rats were intubated and received ventilation at 20 cmH2O of inspiratory pressure (PC20) by a G5 ventilator for 4 h as a control group, and an intervention group received the same inspiratory pressure as well as treated with HC at 1 mg/kg at the third hour of ventilation (PC20+HC). The hemodynamic and respiratory data showed similar changes in the two groups that were exposed to VILI. The pathophysiological results showed that the HC treatment attenuated the VILI severity. Treatment of HC increased IL-33 expression in the bronchoalveolar lavage fluid (BALF). These results demonstrated that IL-33 is involved in VILI processing and HC treatment attenuated IL-33 involvement in inflammatory activation in VILI. In conclusion, IL-33 may play an important role in VILI.

Beauvericin-induced cell apoptosis through the mitogen-activated protein kinase pathway in human nonsmall cell lung cancer A549 cells.

Beauvericin (BEA) is a cyclic hexadepsipeptide that derives from Codyceps cicadae. Our previous study results indicated that the cytotoxic effects of BEA on human A549 lung cancer cells BEA occur through an apoptotic pathway, which involves the up-regulation of cytochrome c release from mitochondria, upregulation of caspase 3 activity, and cellular and morphological changes. In this study, we identified that the mitogen-activated protein kinase (MAPK) inhibitor U0126 inhibits the cytotoxic effects of BEA on A549 cells. After exposing human A549 cells to 10 µM BEA, we observed a significant and dose-dependent increase in the percentage of hypoploid (sub-G1) phase cells in the A549 population. Following the pretreatment of the A549 cells with 25 µM U0126, the distribution of A549 cells in the sub-G1 phase decreased significantly. The BEA treatment resulted in a significant increase apoptosis in A549 cells by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Moreover, the MEK1/2 (mitogen-activated protein kinase kinase)-ERK42/44 (extracellular signal-regulated kinases)-90RSK (ribosomal s6 kinase) signaling pathway was activated in BEA-induced apoptotic A549 cells. Furthermore, treatment with MEK1/2 inhibitor U0126 was capable to attenuate the BEA induced typical apoptotic morphological change, apoptotic cells, and MEK1/2-ERK42/44-90RSK signaling pathway. These results suggested that MEK1/2-ERK42/44-90RSK signaling pathway may play a important role in BEA-induced apoptosis in human NSCLC A549 cancer cells.

ß-Elemonic acid inhibits the cell proliferation of human lung adenocarcinoma A549 cells: The role of MAPK, ROS activation and glutathione depletion.

ß-elemonic acid, a known triterpene, exhibits anti-inflammatory effects, yet research on the pharmacological effects of ß-elemonic acid is rare. We investigated the anticancer effects and the related molecular mechanisms of ß-elemonic acid on human non-small cell lung cancer (NSCLC) A549 cells. The effects of ß-elemonic acid on the growth of A549 cells were studied using a 3-(4,5)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected using Annexin V staining. The effect of ß-elemonic acid on the cell cycle of A549 cells was assessed using the propidium iodide method. The change in reactive oxygen species (ROS) was detected using a dichlorodihydrofluorescein diacetate (DCFH-DA) assay with microscopic examination. The expression levels of Bcl-2 family proteins, mitogen-activated protein kinase (MAPK) family proteins and cyclooxygenase 2 (COX-2) were detected using western blot analysis. Our data revealed that ß-elemonic acid strongly induced human A549 lung cancer cell death in a dose- and time-dependent manner as determined by the MTT assay. ß-elemonic acid-induced cell death was considered to be apoptotic when the phosphatidylserine exposure was observed using Annexin V staining. The death of human A549 lung cancer cells was caused by apoptosis induced by activation of ROS activity, increase in the sub-G1 proportion, downregulation of Bcl-2 expression, upregulation of Bax expression and inhibition of the MAPK signaling pathways. These results clearly demonstrated that ß-elemonic acid inhibits proliferation by inducing hypoploid cells and cell apoptosis. Moreover, the anticancer effects of ß-elemonic acid were related to the MAPK signaling pathway, ROS activation and glutathione depletion in human A549 lung cancer cells.

HYS-32-Induced Microtubule Catastrophes in Rat Astrocytes Involves the PI3K-GSK3beta Signaling Pathway.

HYS-32 is a novel derivative of combretastatin-A4 (CA-4) previously shown to induce microtubule coiling in rat primary astrocytes. In this study, we further investigated the signaling mechanism and EB1, a microtubule-associated end binding protein, involved in HYS-32-induced microtubule catastrophes. Confocal microscopy with double immunofluorescence staining revealed that EB1 accumulates at the growing microtubule plus ends, where they exhibit a bright comet-like staining pattern in control astrocytes. HYS-32 induced microtubule catastrophes in both a dose- and time-dependent manner and dramatically increased the distances between microtubule tips and the cell border. Treatment of HYS-32 (5 µM) eliminated EB1 localization at the microtubule plus ends and resulted in an extensive redistribution of EB1 to the microtubule lattice without affecting the ß-tubulin or EB1 protein expression. Time-lapse experiments with immunoprecipitation further displayed that the association between EB-1 and ß-tubulin was significantly decreased following a short-term treatment (2 h), but gradually increased in a prolonged treatment (6-24 h) with HYS-32. Further, HYS-32 treatment induced GSK3ß phosphorylation at Y216 and S9, where the ratio of GSK3ß-pY216 to GSK3ß-pS9 was first elevated followed by a decrease over time. Co-treatment of astrocytes with HYS-32 and GSK3ß inhibitor SB415286 attenuated the HYS-32-induced microtubule catastrophes and partially prevented EB1 dissociation from the plus end of microtubules. Furthermore, co-treatment with PI3K inhibitor LY294002 inhibited HYS-32-induced GSK3ß-pS9 and partially restored EB1 distribution from the microtubule lattice to plus ends. Together these findings suggest that HYS-32 induces microtubule catastrophes by preventing EB1 from targeting to microtubule plus ends through the GSK3ß signaling pathway.

Membrane translocation of IL-33 receptor in ventilator induced lung injury.

Ventilator-induced lung injury is associated with inflammatory mechanism and causes high mortality. The objective of this study was to discover the role of IL-33 and its ST2 receptor in acute lung injury induced by mechanical ventilator (ventilator-induced lung injury; VILI). Male Wistar rats were intubated after tracheostomy and received ventilation at 10 cm H2O of inspiratory pressure (PC10) by a G5 ventilator for 4 hours. The hemodynamic and respiratory parameters were collected and analyzed. The morphological changes of lung injury were also assessed by histological H&E stain. The dynamic changes of lung injury markers such as TNF-α and IL-1ß were measured in serum, bronchoalveolar lavage fluid (BALF), and lung tissue homogenization by ELISA assay. During VILI, the IL-33 profile change was detected in BALF, peripheral serum, and lung tissue by ELISA analysis. The Il-33 and ST2 expression were analyzed by immunohistochemistry staining and western blot analysis. The consequence of VILI by H&E stain showed inducing lung congestion and increasing the expression of pro-inflammatory cytokines such as TNF-α and IL-1ß in the lung tissue homogenization, serum, and BALF, respectively. In addition, rats with VILI also exhibited high expression of IL-33 in lung tissues. Interestingly, the data showed that ST2L (membrane form) was highly accumulated in the membrane fraction of lung tissue in the PC10 group, but the ST2L in cytosol was dramatically decreased in the PC10 group. Conversely, the sST2 (soluble form) was slightly decreased both in the membrane and cytosol fractions in the PC10 group compared to the control group. In conclusion, these results demonstrated that ST2L translocation from the cytosol to the cell membranes of lung tissue and the down-expression of sST2 in both fractions can function as new biomarkers of VILI. Moreover, IL-33/ST2 signaling activated by mechanically responsive lung injury may potentially serve as a new therapy target.

Habitual sleep-wake behaviors and lifestyle as predictors of diurnal cortisol patterns in young breast cancer survivors: a longitudinal study.

OBJECTIVE: This study aimed to identify predictors of changes in diurnal cortisol patterns during the 8-month follow up period for young breast cancer survivors. Among the potential predictors were tumor size, lymph node metastasis, changes in sleep problems, habitual time of awakening and bedtime, physical activity levels, body mass index (BMI), and depressive levels across 8 months. METHODS: The participants were 62 breast cancer women who were aged 40 years and below, and had completed active breast cancer treatment. The longitudinal data were collected at four points: baseline assessment (T0) and three follow-ups after baseline: T1 (in the 2nd month), T2 (in the 5th month), and T3 (in the 8th month). The participants collected their salivary cortisol at home at six time points: upon waking, 30 and 45min after waking, and at 1200h, 1700h, and 2100h. They also completed several questionnaires: the Medical Outcomes Study Sleep scale; the Beck Depression Inventory-II, physical activity levels on a 10-point scale, time of going to bed, time of awakening, and total sleep hours. RESULTS: This study found that the main predictors of changes toward flatter diurnal cortisol patterns during the 8-month follow ups were greater tumor sizes, increases of BMI scores, and habitually later times of awakening. CONCLUSIONS: While greater tumor sizes represent biological vulnerability of disruption of cortisol circadian rhythm, maintaining an appropriate BMI and good sleep habits could be a protective factor for normal cortisol regulation, which likely helps to reduce early mortality in young breast cancer survivors.

The Eag domain regulates the voltage-dependent inactivation of rat Eag1 K+ channels.

Eag (Kv10) and Erg (Kv11) belong to two distinct subfamilies of the ether-à-go-go K+ channel family (KCNH). While Erg channels are characterized by an inward-rectifying current-voltage relationship that results from a C-type inactivation, mammalian Eag channels display little or no voltage-dependent inactivation. Although the amino (N)-terminal region such as the eag domain is not required for the C-type inactivation of Erg channels, an N-terminal deletion in mouse Eag1 has been shown to produce a voltage-dependent inactivation. To further discern the role of the eag domain in the inactivation of Eag1 channels, we generated N-terminal chimeras between rat Eag (rEag1) and human Erg (hERG1) channels that involved swapping the eag domain alone or the complete cytoplasmic N-terminal region. Functional analyses indicated that introduction of the homologous hERG1 eag domain led to both a fast phase and a slow phase of channel inactivation in the rEag1 chimeras. By contrast, the inactivation features were retained in the reverse hERG1 chimeras. Furthermore, an eag domain-lacking rEag1 deletion mutant also showed the fast phase of inactivation that was notably attenuated upon co-expression with the rEag1 eag domain fragment, but not with the hERG1 eag domain fragment. Additionally, we have identified a point mutation in the S4-S5 linker region of rEag1 that resulted in a similar inactivation phenotype. Biophysical analyses of these mutant constructs suggested that the inactivation gating of rEag1 was distinctly different from that of hERG1. Overall, our findings are consistent with the notion that the eag domain plays a critical role in regulating the inactivation gating of rEag1. We propose that the eag domain may destabilize or mask an inherent voltage-dependent inactivation of rEag1 K+ channels.

Sensitization by pulmonary reactive oxygen species of rat vagal lung C-fibers: the roles of the TRPV1, TRPA1, and P2X receptors.

Sensitization of vagal lung C-fibers (VLCFs) induced by mediators contributes to the pathogenesis of airway hypersensitivity, which is characterized by exaggerated sensory and reflex responses to stimulants. Reactive oxygen species (ROS) are mediators produced during airway inflammation. However, the role of ROS in VLCF-mediated airway hypersensitivity has remained elusive. Here, we report that inhalation of aerosolized 0.05% H2O2 for 90 s potentiated apneic responses to intravenous capsaicin (a TRPV1 receptor agonist), α,ß-methylene-ATP (a P2X receptor agonist), and phenylbiguanide (a 5-HT3 receptor agonist) in anesthetized rats. The apneic responses to these three stimulants were abolished by vagatomy or by perivagal capsaicin treatment, a procedure that blocks the neural conduction of VLCFs. The potentiating effect of H2O2 on the apneic responses to these VLCF stimulants was prevented by catalase (an enzyme that degrades H2O2) and by dimethylthiourea (a hydroxyl radical scavenger). The potentiating effect of H2O2 on the apneic responses to capsaicin was attenuated by HC-030031 (a TRPA1 receptor antagonist) and by iso-pyridoxalphosphate-6-azophenyl-2',5'-disulphonate (a P2X receptor antagonist). The potentiating effect of H2O2 on the apneic responses to α,ß-methylene-ATP was reduced by capsazepine (a TRPV1 receptor antagonist), and by HC-030031. The potentiating effect of H2O2 on the apneic responses to phenylbiguanide was totally abolished when all three antagonists were combined. Consistently, our electrophysiological studies revealed that airway delivery of aerosolized 0.05% H2O2 for 90 s potentiated the VLCF responses to intravenous capsaicin, α,ß-methylene-ATP, and phenylbiguanide. The potentiating effect of H2O2 on the VLCF responses to phenylbiguanide was totally prevented when all antagonists were combined. Inhalation of 0.05% H2O2 indeed increased the level of ROS in the lungs. These results suggest that 1) increased lung ROS sensitizes VLCFs, which leads to exaggerated reflex responses in rats and 2) the TRPV1, TRPA1, and P2X receptors are all involved in the development of this airway hypersensitivity.

The punctate localization of rat Eag1 K+ channels is conferred by the proximal post-CNBHD region.

BACKGROUND: In mammals, Eag K+ channels (KV10) are exclusively expressed in the brain and comprise two isoforms: Eag1 (KV10.1) and Eag2 (KV10.2). Despite their wide presence in various regions of the brain, the functional role of Eag K+ channels remains obscure. Here we address this question by characterizing the subcellular localization of rat Eag1 (rEag1) and rat Eag2 (rEag2) in hippocampal neurons, as well as determining the structural basis underlying their different localization patterns. RESULTS: Immunofluorescence analysis of young and mature hippocampal neurons in culture revealed that endogenous rEag1 and rEag2 K+ channels were present in both the dendrosomatic and the axonal compartments. Only rEag1 channels displayed a punctate immunostaining pattern and showed significant co-localization with PSD-95. Subcellular fractionation analysis further demonstrated a distinct enrichment of rEag1 in the synaptosomal fraction. Over-expression of recombinant GFP-tagged Eag constructs in hippocampal neurons also showed a significant punctate localization of rEag1 channels. To identify the protein region dictating the Eag channel subcellular localization pattern, we generated a variety of different chimeric constructs between rEag1 and rEag2. Quantitative studies of neurons over-expressing these GFP-tagged chimeras indicated that punctate localization was conferred by a segment (A723-R807) within the proximal post-cyclic nucleotide-binding homology domain (post-CNBHD) region in the rEag1 carboxyl terminus. CONCLUSIONS: Our findings suggest that Eag1 and Eag2 K+ channels may modulate membrane excitability in both the dendrosomatic and the axonal compartments and that Eag1 may additionally regulate neurotransmitter release and postsynaptic signaling. Furthermore, we present the first evidence showing that the proximal post-CNBHD region seems to govern the Eag K+ channel subcellular localization pattern.

The partner's insecure attachment, depression and psychological well-being as predictors of diurnal cortisol patterns for breast cancer survivors and their spouses.

The purpose of this study was to explore whether stress from individual's and partner's depression, anxiety, sleep disturbances, insecure attachment and meaning in life were predictors of diurnal cortisol patterns in breast cancer survivors and their spouses. Thirty-four couple dyads participated in this eight-month follow-up study. The breast cancer survivors and their spouses completed the Medical Outcomes Study Sleep scale, the Beck Depression Inventory-II, the State Trait Anxiety Inventory, the Experiences in Close Relationships-Revised scale and the Meaning in Life Questionnaire, and they collected salivary cortisol at home at the time of awakening, 30 and 45 min after waking and at 1200 h, 1700 h and 2100 h. Diurnal cortisol slopes of survivors and spouses are positively correlated. But the factors associated with diurnal cortisol patterns are different between survivors and spouses. For survivors, neither survivor individuals' nor spouses' psychosocial factors were the predictors of survivors' diurnal cortisol patterns. For spouses, the survivors' higher anxious attachment style was the main predictor of spouses' flatter diurnal cortisol patterns. In conclusion, for spouses, psychophysiological stress responses are mainly influenced by breast cancer survivors' insecure attachment. Future couple supportive care interventions can address survivors' attachment styles in close relationships in order to improve neuroendocrine functions for both breast cancer survivors and their spouses.

Efficacy of psychotherapy on diurnal cortisol patterns and suicidal ideation in adjustment disorder with depressed mood.

AIMS: The aims were to examine the effects of psychotherapy on depressive and anxiety symptoms, the occurrence of suicidal ideations and diurnal cortisol patterns in patients with adjustment disorder (AD) with depressed mood. METHODS: Participants recruited from an outpatient department of psychiatry at a general hospital were randomly assigned to one of two groups: 34 in psychotherapy group and 37 in control group. The control group consisted of one-session psychoeducation. Psychotherapy included the eight-weekly body-mind-spirit (BMS) group psychotherapy. Measures included Beck Depression Inventory-II and State Trait Anxiety Inventory. Salivary cortisol samples were collected from the patients at their homes on awakening; 30 and 45 min after awakening; and at 1200, 1700 and 2100 h. Measurements were taken at baseline and at months 2 (end of intervention), 5, 8 and 14. RESULTS: There was no differential change over time between the BMS and control groups in self-reported depression or anxiety symptoms. However, suicidal ideation appeared to be reduced in the psychotherapy group. Changes in diurnal cortisol patterns were also significantly different in group × time interactions, in favor of BMS group. CONCLUSIONS: Psychotherapy likely provides improvements in psychobiological stress responses and decreases the occurrence of suicidal ideation in patients with AD.