Alkaloids from Corydalis saxicola and their antiproliferative activity against cancer cells.

Eight undescribed alkaloids named corydalisine D-K (1-7), including one isoquinoline benzopyranone alkaloid (1), one benzocyclopentanone alkaloid (2), four benzofuranone alkaloids (3, 4, and 5a/5b) and two protoberberine alkaloids (6 and 7), along with fourteen known ones, were isolated from the Corydalis saxicola. Their structures, including absolute configurations, were unambiguously identified using spectroscopic techniques, single-crystal X-ray diffraction and electron circular dichroism calculation. Compounds 2, 14 and 21 exhibit antiproliferative activity against five cancer cell lines. The aporphine alkaloid demethylsonodione (compound 14), which exhibited the best activity (IC50 = 3.68 ± 0.25 µM), was subjected to further investigation to determine its mechanism of action against the T24 cell line. The molecular mechanism was related to the arrest of cell cycle S-phase, inhibition of CDK2 expression, accumulation of reactive oxygen species (ROS), induction of cell apoptosis, inhibition of cell migration, and activation of p38 MAPK signaling pathway. The results indicated that 14 could be used as a potential candidate agent for further development of anti-bladder transitional cell carcinoma.

Combination of cataract surgery with intravitreal injection of dexamethasone intravitreal implant (Ozurdex) for uveitis-induced cataract.

AIM: To evaluate the long-term results of patients with chronic uveitis-induced cataract by phacoemulsification with IOL implantation and intravitreal injection of dexamethasone (DEX) intravitreal implant (Ozurdex). METHODS: The study included 32 eyes of 26 patients treated with DEX implant due to chronic uveitis-induced cataract and followed up for at least a year. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), anterior chamber reaction, central macular thickness (CMT), intraoperative and postoperative complications and uveitis recurrence were analyzed retrospectively. RESULTS: A successful surgery was performed in all patients. The average follow-up period was 12mo. The female/male ratio was 13/13. Mean age was 45.65±3.83y (range 26 to 65y). Etiologically, rheumatic arthritis occurred in 6 patients (18.75%), ankylosing spondylitis in 4 (12.50%), HLA-B27 associated uveitis in 3 (9.38%), Vogt-Koyanagi-Harada-associated uveitis in 4 (12.50%) , Behcet's disease in 2 (6.25%), and 7 (21.88%) suffered from unknown diseases. All 32 eyes had varying degrees of improvement at 12mo after surgery, with 2 eyes showing BCVA of 0.1 or below (6.25%), 6 having 0.1-0.5 (18.75%), 18 of 0.5-1.0 (56.25%), and 6 of 1.0 or above (18.75%). No cases with increased IOP were observed. The values of mean CMT was increased at day 1, decreased at 1, 3mo after surgery and increased at 6, 12mo after surgery. No severe uveitis reactions, such as fibrinous exudates in the anterior chamber and exudative membrane formation on the anterior surface of the IOL, were observed after surgery. CONCLUSION: The present studies show that intravitreal injection of Ozudex during cataract operation can provide a new option for the clinical treatment of uveitis-induced cataract.

Soluble epoxide hydrolase and TRPC3 channels jointly contribute to homocysteine-induced cardiac hypertrophy: Interrelation and regulation by C/EBPß.

OBJECTIVES: Studies in certain cardiac hypertrophy models suggested the individual role of soluble epoxide hydrolase (sEH) and canonical transient receptor potential 3 (TRPC3) channels, however, whether they jointly mediate hypertrophic process remains unexplored. Hyperhomocysteinemia promotes cardiac hypertrophy while the involvement of sEH and TRPC3 channels remains unknown. This study aimed to explore the role of, and interrelation between sEH and TRPC3 channels in homocysteine-induced cardiac hypertrophy. METHODS: Rats were fed methionine-enriched diet to induce hyperhomocysteinemia. H9c2 cells and neonatal rat cardiomyocytes were incubated with homocysteine. Cardiac hypertrophy was evaluated by echocardiography, histological examination, immunofluorescence imaging, and expressions of hypertrophic markers. Epoxyeicosatrienoic acids (EETs) were determined by ELISA. TRPC3 current was recorded by patch-clamp. Gene promotor activity was measured using dual-luciferase reporter assay. RESULTS: Inhibition of sEH by 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) reduced ventricular mass, lowered the expression of hypertrophic markers, decreased interstitial collagen deposition, and improved cardiac function in hyperhomocysteinemic rats, associated with restoration of EETs levels in myocardium. TPPU or knockdown of sEH suppressed TRPC3 transcription and translation as well as TRPC3 current that were enhanced by homocysteine. Exogenous 11,12-EET inhibited homocysteine-induced TRPC3 expression and cellular hypertrophy. Silencing C/EBPß attenuated, while overexpressing C/EBPß promoted homocysteine-induced hypertrophy and expressions of sEH and TRPC3, resulting respectively from inhibition or activation of sEH and TRPC3 gene promoters. CONCLUSIONS: sEH and TRPC3 channels jointly contribute to homocysteine-induced cardiac hypertrophy. Homocysteine transcriptionally activates sEH and TRPC3 genes through a common regulatory element C/EBPß. sEH activation leads to an upregulation of TRPC3 channels via a 11,12-EET-dependent manner.

Ginsenoside Rb1 from Panax notoginseng Suppressed TNF-α-Induced Matrix Metalloproteinase-9 via the Suppression of Double-Strand RNA-Dependent Protein Kinase (PKR)/NF-κB Pathway.

Chronic inflammation is commonly accompanied by the stimulation of matrix metalloproteinases (MMPs) production and the degradation of the extracellular matrix. The overexpression of MMP-9 (Gelatinase B) highly participates in the progression of pathetic cardiac remodeling and liver cancer metastasis. Panax notoginseng (Burkill) F. H. Chen (Sanqi), a widely used traditional Chinese medicinal herb, shows myocardial protective and anti-tumor effects. In this study, we examined the inhibitory effect of different PNG extracts on tumor necrosis factor (TNF)-α-induced MMP-9 expression in cardiac myoblast H9c2 cells. Using a bioassay-guided fractionation scheme, the most active extract was fractionated by silica gel column chromatography and high-performance liquid chromatography until an active compound was obtained. The compound was identified as Ginsenoside Rb1 by nuclear magnetic resonance. Ginsenoside Rb1 inhibited TNF-α-induced MMP-9 production in both H9c2 and liver carcinoma HepG-2 cells. Interestingly, it did not affect the MMP-2 (Gelatinase A) level and the cell proliferation of the two cell lines. The inhibitory effects of Ginsenoside Rb1 may be due to its modulation of double-strand RNA-dependent protein kinase and nuclear factor kappa B signaling pathways. The results reveal the potential use of Ginsenoside Rb1 for the treatment of inflammatory and MMP-9-related cardiac remodeling and metastasis of hepatocellular carcinomas.

Targeting IRE1α-JNK-c-Jun/AP-1-sEH Signaling Pathway Improves Myocardial and Coronary Endothelial Function Following Global Myocardial Ischemia/Reperfusion.

Objectives: Endoplasmic reticulum (ER) stress and soluble epoxide hydrolase (sEH) upregulation/activation have been implicated in myocardial ischemia/reperfusion (I/R) injury. We previously reported that ER stress mediates angiotensin II-induced sEH upregulation in coronary endothelium, whether and how ER stress regulates sEH expression to affect postischemic cardiac function remain unexplored. This study aimed to unravel the signaling linkage between ER stress and sEH in an ex vivo model of myocardial I/R injury. Methods: Hearts from male Wistar-Kyoto rats were mounted on a Langendorff apparatus and randomly allocated to 7 groups, including control, I/R (30-min ischemia and 60-min reperfusion), and I/R groups pretreated with one of the following inhibitors: 4-PBA (targeting: ER stress), GSK2850163 (IRE1α), SP600125 (JNK), SR11302 (AP-1), and DCU (sEH). The inhibitor was administered for 15 min before ischemia with a peristaltic pump. Hemodynamic parameters including left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), and maximal velocity of contraction (+dp/dtmax) and relaxation (-dp/dtmax) of the left ventricle were continuously recorded using an intraventricular balloon. Endothelial dilator function of the left anterior descending artery was studied in a wire myograph upon completion of reperfusion. The expression of ER stress molecules, JNK, c-Jun, and sEH was determined by western-blot. Results: I/R decreased LVSP (105.5±6.4 vs. 146.9±13.4 mmHg), and increased LVEDP (71.4±3.0 vs. 6.0±2.7 mmHg), with a resultant decreased LVDP (34.1±9.2 vs. 140.9±13.1 mmHg). I/R attenuated +dp/dtmax (651.7±142.1 vs. 2806.6±480.6 mmHg/s) and -dp/dtmax (-580.0±109.6 vs. -2118.0±244.9 mmHg/s) (all ps<0.001). The I/R-induced cardiac dysfunction could be alleviated by 4-PBA (LVSP 119.5±15.6 mmHg, p<0.01; LVEDP 21.2±4.2 mmHg, LVDP 98.3±12.0 mmHg, +dp/dtmax 2166.7±208.4 mmHg/s, and -dp/dtmax -1350.9±99.8 mmHg/s, all ps<0.001), GSK2850163 (LVSP 113.4±10.9 mmHg, p<0.01; LVEDP 37.1±3.1 mmHg, LVDP 76.3±13.9 mmHg, +dp/dtmax 1586.5±263.3 mmHg/s, -dp/dtmax -1127.7±159.9 mmHg/s, all ps<0.001), SP600125 (LVSP 113.9±5.6 mmHg, LVDP 40.5±3.3 mmHg, +dp/dtmax 970.1±89.8 mmHg/s, all ps<0.01), SR11302 (LVSP 97.9±7.5 mmHg, p<0.01; LVEDP 52.7±8.6mmHg, p<0.001; LVDP 45.2±9.8mmHg, p<0.05; +dp/dtmax 1231.5±196.6 mmHg/s, p<0.01; -dp/dtmax -658.3±68.9 mmHg/s, p<0.05), or DCU (LVSP 109.9±4.1 mmHg, p<0.01; LVEDP 11.7±1.8 mmHg, LVDP 98.2±4.9 mmHg, +dp/dtmax 1869.8±121.9 mmHg/s, and -dp/dtmax -1492.3±30.8 mmHg/s, all ps<0.001). The relaxant response of the coronary artery to acetylcholine was decreased after I/R in terms of both magnitude and sensitivity (p<0.001). All inhibitors improved acetylcholine-induced relaxation. Global I/R increased sEH expression and induced ER stress in both myocardium and coronary artery. Inhibition of ER stress or IRE1α downregulated I/R-induced sEH expression and inhibited JNK and c-Jun phosphorylation. Both JNK and AP-1 inhibitors lowered sEH level in myocardium and coronary artery in I/R-injured hearts. Conclusions: This study deciphered the molecular linkage between ER stress and sEH regulation in global I/R insult by uncovering a novel signaling axis of IRE1α-JNK-c-Jun/AP-1-sEH, which provided basis for future research on the therapeutic potential of targeting the IRE1α-JNK-c-Jun/AP-1-sEH axis for ischemic myocardial injury.

The clinical and prognostic factors for biliary neuroendocrine neoplasm: a study based on the SEER database.

BACKGROUND: In this study, we aimed at elucidating the postoperative survival and prognostic factors in patients with biliary neuroendocrine neoplasm (NEN). METHODS: Cases of biliary system NEN and adenocarcinoma from 1975 to 2016 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. A propensity score matching (PSM) method was used to adjust baseline differences in clinicopathological characteristics in our analysis. The Kaplan-Meier analysis was carried out for survival analysis. RESULTS: A total of 233 patients with biliary system NEN were enrolled in this study, of which 119 patients' lesions located in gallbladder, while the others' located in bile duct. The postoperative overall survival of bile duct NEN is significantly longer than that of gallbladder NEN (P < 0.001). For gallbladder NENs, surgery method (P = 0.020) and lymph node metastasis (P = 0.018) were identified as independent prognostic factors. In terms of ampulla of vater (AOV) NENs, age (P = 0.017) and lymph node metastasis (P = 0.006) were identified as independent prognostic factors, while grade (P = 0.002) and lymph node metastasis (P = 0.036) were identified as independent prognostic factors for extrahepatic bile duct (EBD) NENs. PSM analysis indicated that patients with biliary duct NENs have a better postoperative prognosis than biliary duct adenocarcinoma. CONCLUSIONS: Patients with NEN have better overall survival than patients with adenocarcinoma. Gallbladder NEN has an adverse prognosis than that of biliary tract NEN. The pathological subtype, differentiation, lymph node metastasis, surgery method, and lymph node resection could affect the postoperative prognosis of the gallbladder and biliary tract NEN.

del Nido cardioplegia better preserves cardiac diastolic function but histidine-tryptophan-ketoglutarate is better for endothelial function.

OBJECTIVES: The effectiveness of myocardial protection of cardioplegia has been a matter of debate for decades. This study was designed to compare cardiac and endothelial protection of 3 clinically used cardioplegias: del Nido cardioplegia (DNC), histidine-tryptophan-ketoglutarate (HTK) and blood cardioplegia (BC) followed by HTK (BC + HTK) in a rat model of ischaemia/reperfusion (I/R). METHODS: Sixty male Wistar rats were subjected to either 120 min of global ischaemia at 4°C followed by 90 min of reperfusion (I/R) at 37°C or no I/R (control) in a Langendorff apparatus and were randomly allocated to 5 groups: control, I/R, DNC, HTK and BC + HTK. Cold cardioplegia solutions were administered at doses of 20 ml/kg for DNC and HTK or 10 ml/kg for BC followed by HTK. Haemodynamic parameters were continuously recorded using an intraventricular balloon. The endothelium-dependent relaxation to acetylcholine was measured in the left anterior descending artery using a myograph. Protein expression of cardiac troponin T (cTnT) and creatine kinase MB was determined by western blot. RESULTS: During reperfusion, HTK had higher left ventricular systolic pressure whereas DNC had lower left ventricular end-diastolic pressure, better left ventricular developed pressure and best +dp/dtmax and -dp/dtmax than the other 2 groups but the differences disappeared at the end of the reperfusion. HTK or BC + HTK preserves the acetylcholine-induced endothelium-dependent relaxation better than DNC (Emax = 48.2 ± 8.0% in DNC vs 75.0 ± 8.0% in HTK, P < 0.05; vs 96.9 ± 3.5% in BC + HTK, P < 0.001). The protein levels of cTnT and creatine kinase MB were downregulated in the 3 groups. CONCLUSIONS: All 3 cardioplegias prevented myocardial damage against I/R injury at the end of reperfusion. DNC demonstrated better preserved diastolic function of the left ventricle whereas HTK or BC + HTK showed better preserved coronary endothelial function. These findings may suggest that currently no 'perfect' cardioplegia exists and that exploration for the 'perfect' cardioplegia is needed.

Homocysteine alters vasoreactivity of human internal mammary artery by affecting the KCa channel family.

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for atherosclerotic heart disease. We previously demonstrated that disruption of calcium-activated potassium (KCa) channel activity is involved in homocysteine-induced dilatory dysfunction of porcine coronary arteries. Recently we reported that the KCa channel family, including large-, intermediate-, and small-conductance KCa (BKCa, IKCa, and SKCa) subtypes, are abundantly expressed in human internal mammary artery (IMA). In this study, we further investigated whether homocysteine affects the expression and functionality of the KCa channel family in this commonly used graft for coronary artery bypass surgery (CABG). METHODS: Residual IMA segments obtained from patients undergoing CABG were studied in a myograph for the role of KCa subtypes in both vasorelaxation and vasoconstriction. The expression and distribution of KCa subtypes were detected by Western blot and immunohistochemistry. RESULTS: Both the BKCa channel activator NS1619 and the IKCa/SKCa channel activator NS309 evoked significant IMA relaxation. Homocysteine exposure suppressed NS1619-induced relaxation whereas showed no influence on NS309-induced response. Blockade of BKCa but not IKCa and SKCa subtypes significantly suppressed acetylcholine-induced relaxation and enhanced U46619-induced contraction. Homocysteine compromised the vasodilating activity of the BKCa subtype in IMA, associated with a lowered protein level of the BKCa ß1-subunit. Homocysteine potentiated the role of IKCa and SKCa subtypes in mediating endothelium-dependent relaxation without affecting the expression of these channels. CONCLUSIONS: Homocysteine reduces the expression of BKCa ß1-subunit and compromises the vasodilating activity of BKCa channels in IMA. Unlike BKCa, IKCa and SKCa subtypes are unessential for IMA vasoregulation, whereas the loss of BKCa functionality in hyperhomocysteinemia enhances the role of IKCa and SKCa subtypes in mediating endothelial dilator function. Targeting BKCa channels may form a strategy to improve the postoperative graft performance in CABG patients with hyperhomocysteinemia who receive IMA grafting.

Clinical correlation of cadherin-17 marker with advanced tumor stages and poor prognosis of cholangiocarcinoma.

BACKGROUND AND OBJECTIVES: In this retrospective study, we examined the CA17 tissue expression and analyzed its clinical significance in cholangiocarcinoma (CCA). MATERIALS AND METHODS: Immunohistochemistry was performed to assess CA17 expression on tissue microarrays in a training cohort enrolling 120 CCA patients and a validation cohort comprising 60 CCA patients. Image pro plus was applied to score the staining intensity and expression level of CA17 marker. Kaplan-Meier analysis, Cox's proportional hazards regression, and nomogram were applied to evaluate the prognostic significance of CA17. RESULTS: CA17 cancer biomarker over-expression was significantly observed in CCA compared to their non-tumor counterparts, and positively correlated with aggressive tumor phenotypes, like lymph node metastasis. Meanwhile, patients with high expression of CA17 correlated with worse postoperative overall survival (OS) and recurrence-free survival. Besides, multivariate analysis identified that CA17 expression was an independent prognostic factor for cholangiocarcinoma patients, which indicated that the CA17 could be more efficient than serum CA19-9 in predicting the OS of CCA patients. Notably, the nomogram integrating CA17 expression had better prognostic performance as compared with current TNM staging systems. CONCLUSION: CA17 was an independent adverse prognostic factor for CCA patients' survival, which may serve as a promising prognostic biomarker for CCA patients.

Calcium-activated potassium channel family in coronary artery bypass grafts.

OBJECTIVES: We examined the expression, distribution, and contribution to vasodilatation of the calcium-activated potassium (KCa) channel family in the commonly used coronary artery bypass graft internal thoracic artery (ITA) and saphenous vein (SV) to understand the role of large conductance KCa (BKCa), intermediate-conductance KCa (IKCa), and small-conductance KCa (SKCa) channel subtypes in graft dilating properties determined by endothelium-smooth muscle interaction that is essential to the postoperative performance of the graft. METHODS: Real-time polymerase chain reaction and western blot were employed to detect the messenger RNA and protein level of KCa channel subtypes. Distribution of KCa channel subtypes was examined by immunohistochemistry. KCa subtype-mediated vasorelaxation was studied using wire myography. RESULTS: Both ITA and SV express all KCa channel subtypes with each subtype distributed in both endothelium and smooth muscle. ITA and SV do not differ in the overall expression level of each KCa channel subtype, corresponding to comparable relaxant responses to respective subtype activators. In ITA, BKCa is more abundantly expressed in smooth muscle than in endothelium, whereas SKCa exhibits more abundance in the endothelium. In comparison, SV shows even distribution of KCa channel subtypes in the 2 layers. The BKCa subtype in the KCa family plays a significant role in vasodilatation of ITA, whereas its contribution in SV is quite limited. CONCLUSIONS: KCa family is abundantly expressed in ITA and SV. There are differences between these 2 grafts in the abundance of KCa channel subtypes in the endothelium and the smooth muscle. The significance of the BKCa subtype in vasodilatation of ITA may suggest the potential of development of BKCa modulators for the prevention and treatment of ITA spasm during/after coronary artery bypass graft surgery.

Experimental Demonstration of a Dusty Plasma Ratchet Rectification and Its Reversal.

The naturally persistent flow of hundreds of dust particles is experimentally achieved in a dusty plasma system with the asymmetric sawteeth of gears on the electrode. It is also demonstrated that the direction of the dust particle flow can be controlled by changing the plasma conditions of the gas pressure or the plasma power. Numerical simulations of dust particles with the ion drag inside the asymmetric sawteeth verify the experimental observations of the flow rectification of dust particles. Both experiments and simulations suggest that the asymmetric potential and the collective effect are the two keys in this dusty plasma ratchet. With the nonequilibrium ion drag, the dust flow along the asymmetric orientation of this electric potential of the ratchet can be reversed by changing the balance height of dust particles using different plasma conditions.

Clinical outcomes with large macular holes using the tiled transplantation internal limiting membrane pedicle flap technique.

AIM: To report the surgical technique and efficacy of the tiled transplantation internal limiting membrane (ILM) pedicle flap technique after vitrectomy for 33 patients with large macular hole (MH). METHODS: This study was a prospective noncontrolled interventional study. All patients were treated by vitrectomy, the tiled transplantation ILM pedicle flap and gas tamponade. All patients underwent visual acuity measurements and optical coherence tomography (OCT), during preoperative and the follow-up visits postoperative. RESULTS: Two high-myopic patient had flap dislocation during surgery. The thorough closure of MH following the tiled transplantation ILM pedicle flap technique was ultimately achieved in 31 patients observed by OCT imaging (93.94%) 1wk after surgery. Visual acuity improved from 1.51±0.31 (logMAR) preoperative to 0.92±0.30 6mo after surgery (P=0.000). There were no significant changes in OCT finding during the follow-up period from 1mo to 6mo after surgery. CONCLUSION: The tiled transplantation ILM pedicle flap technique provides bridge for retinal gliosis to achieve successful closures of the large MHs, and the microenvironment of this technique is more similar to the normal physiological conditions.

Protection of dilator function of coronary arteries from homocysteine by tetramethylpyrazine: Role of ER stress in modulation of BKCa channels.

OBJECTIVES: We recently reported the involvement of ER stress-mediated BKCa channel inhibition in homocysteine-induced coronary dilator dysfunction. In another study, we demonstrated that tetramethylpyrazine (TMP), an active ingredient of the Chinese herb Chuanxiong, possesses potent anti-ER stress capacity. The present study investigated whether TMP protects BKCa channels from homocysteine-induced inhibition and whether suppression of ER stress is a mechanism contributing to the protection. Furthermore, we explored the signaling transduction involved in TMP-conferred protection on BKCa channels. METHODS: BKCa channel-mediated relaxation was studied in porcine small coronary arteries. Expressions of BKCa channel subunits, ER stress molecules, and E3 ubiquitin ligases, as well as BKCa ubiquitination were determined in porcine coronary arterial smooth muscle cells (PCASMCs). Whole-cell BKCa currents were recorded. RESULTS: Exposure of PCASMCs to homocysteine or the chemical ER stressor tunicamycin increased the expression of ER stress molecules, which was significantly inhibited by TMP. Suppression of ER stress by TMP preserved the BKCa ß1 protein level and restored the BKCa current in PCASMCs, concomitant with an improved BKCa-mediated dilatation in coronary arteries. TMP attenuated homocysteine-induced BKCa ß1 protein ubiquitination, in which inhibition of ER stress-mediated FoxO3a activation and FoxO3a-dependent atrogin-1 and Murf-1 was involved. CONCLUSIONS: Reversal of BKCa channel inhibition via suppressing ER stress-mediated loss of ß1 subunits contributes to the protective effect of TMP against homocysteine on coronary dilator function. Inhibition of FoxO3a-dependent ubiquitin ligases is involved in TMP-conferred normalization of BKCa ß1 protein level. These results provide new mechanistic insights into the cardiovascular benefits of TMP.

Tetramethylpyrazine suppresses angiotensin II-induced soluble epoxide hydrolase expression in coronary endothelium via anti-ER stress mechanism.

Activation of soluble epoxide hydrolase (sEH) is associated with endothelial dysfunction in hypertension, though the underlying mechanisms are inadequately understood and the role of endoplasmic reticulum (ER) stress is yet to be studied in detail. Tetramethylpyrazine (TMP), a major bioactive ingredient of Chinese herb Chuanxiong, is well-known for its cardiovascular benefits. Nevertheless, whether TMP may protect vascular endothelium from ER stress and whether regulation of sEH is involved remain unknown. This study aimed at investigating the role of ER stress in angiotensin-II (Ang-II)-induced sEH dysregulation and elucidating the significance of ER stress regulation in the vasoprotective effect of TMP. Porcine primary coronary artery endothelial cells (PCECs) were used for western blot, ELISA, and reverse-transcription PCR analysis. Porcine coronary arteries were assessed in a myograph for endothelial dilator function. Ang-II induced expression of ER stress molecules in PCECs meanwhile enhanced sEH expression and decreased 11,12-EET. Exposure of PCECs to the chemical ER stress inducer tunicamycin also increased sEH expression. Inhibition of ER stress suppressed sEH upregulation, resulting in an increase of 11,12-EET. The impairment of endothelium-dependent vasorelaxation induced by Ang-II or tunicamycin was ameliorated by inhibitors of ER stress or sEH. TMP showed comparable inhibitory effect to ER stress inhibitors on the expression of ER stress molecules, the dysregulation of sEH/EET, and the impairment of endothelial dilator function. We demonstrated that ER stress mediates Ang-II-induced sEH upregulation in coronary endothelium. TMP has potent anti-ER stress capacity through which TMP normalizes sEH expression and confers protective effect against Ang-II on endothelial function of coronary arteries.

Activation of PERK branch of ER stress mediates homocysteine-induced BKCa channel dysfunction in coronary artery via FoxO3a-dependent regulation of atrogin-1.

The molecular mechanism of endoplasmic reticulum (ER) stress in vascular pathophysiology remains inadequately understood. We studied the role of ER stress in homocysteine-induced impairment of coronary dilator function, with uncovering the molecular basis of the effect of ER stress on smooth muscle large-conductance Ca2+-activated K+ (BKCa) channels. The vasodilatory function of BKCa channels was studied in a myograph using endothelium-denuded porcine small coronary arteries. Primary cultured porcine coronary artery smooth muscle cells were used for mRNA and protein measurements and current recording of BKCa channels. Homocysteine inhibited vasorelaxant response to the BKCachannel opener NS1619, lowered BKCa ß1 subunit protein level and suppressed BKCa current. Inhibition of ER stress restored BKCa ß1 protein level and NS1619-evoked vasorelaxation. Selective blockade of the PKR-like ER kinase (PERK) yielded similarly efficient restoration of BKCa ß1, preserving BKCa current and BKCa-mediated vasorelaxation. The restoration of BKCa ß1 by PERK inhibition was associated with reduced atrogin-1 expression and decreased nuclear localization of forkhead box O transcription factor 3a (FoxO3a). Silencing of atrogin-1 prevented homocysteine-induced BKCa ß1 loss and silencing of FoxO3a prevented atrogin-1 upregulation induced by homocysteine, accompanied by preservation of BKCa ß1 protein level and BKCa current. ER stress mediates homocysteine-induced BKCa channel inhibition in coronary arteries. Activation of FoxO3a by PERK branch underlies the ER stress-mediated BKCa inhibition through a mechanism involving ubiquitin ligase-enhanced degradation of the channel ß1 subunit.

Impairment of Coronary Endothelial Function by Hypoxia-Reoxygenation Involves TRPC3 Inhibition-mediated KCa Channel Dysfunction: Implication in Ischemia-Reperfusion Injury.

Despite increasing knowledge of the significance of calcium-activated potassium (KCa) and canonical transient receptor potential (TRPC) channels in endothelial physiology, no studies so far have investigated the link between these two distinct types of channels in the control of vascular tone in pathological conditions. We previously demonstrated that hypoxia-reoxygenation (H-R) inhibits endothelial KCa and TRPC3 channels in porcine coronary arteries (PCAs). The present study further investigated whether modulation of TRPC3 is involved in H-R-induced KCa channel inhibition and associated vasodilatory dysfunction using approaches of wire myography, whole-cell voltage-clamp, and coimmunoprecipitation. Pharmacological inhibition or siRNA silencing of TRPC3 significantly suppressed bradykinin-induced intermediate- and small-conductance KCa (IKCa and SKCa) currents in endothelial cells of PCAs (PCAECs). TRPC3 protein exists in physical association with neither IKCa nor SKCa. In H-R-exposed PCAECs, the response of IKCa and SKCa to bradykinin-stimulation and to TRPC3-inhibition was markedly weakened. Activation of TRPC3 channels restored H-R-suppressed KCa currents in association with an improved endothelium-derived hyperpolarizing factor (EDHF)-type vasorelaxation. We conclude that inhibition of TRPC3 channels contributes to H-R-induced suppression of KCa channel activity, which serves as a mechanism underlying coronary endothelial dysfunction in ischemia-reperfusion (I-R) injury and renders TRPC3 a potential target for endothelial protection in I-R conditions.

Hydrothermal synthesis of organometal halide perovskites for Li-ion batteries.

A facile hydrothermal method was developed to prepare CH3NH3PbBr3 and CH3NH3PbI3. The as-prepared products were utilized in lithium batteries as anode materials with good performance. Considering the structural diversity, more hybrid perovskites can be targets for further optimization, indicating their promising potential in Li-ion battery applications.

ER stress mediates homocysteine-induced endothelial dysfunction: Modulation of IKCa and SKCa channels.

OBJECTIVE: It remains incompletely understood how homocysteine impairs endothelial function. Whether mechanisms such as calcium-activated potassium (KCa) channels are involved is uncertain and the significance of endoplasmic reticulum (ER) stress in KCa channel-dependent endothelial function in hyperhomocysteinemia remains unexplored. We investigated the effect of homocysteine on endothelial KCa channels in coronary vasculature with further exploration of the role of ER stress. METHODS: Vasorelaxation mediated by intermediate- and small-conductance KCa (IKCa and SKCa) channels was studied in porcine coronary arteries in a myograph. IKCa and SKCa channel currents were recorded by whole-cell patch-clamp in coronary endothelial cells. Protein levels of endothelial IKCa and SKCa channels were determined for both whole-cell and surface expressions. RESULTS: Homocysteine impaired bradykinin-induced IKCa and SKCa-dependent EDHF-type relaxation and attenuated the vasorelaxant response to the channel activator. IKCa and SKCa currents were suppressed by homocysteine. Inhibition of ER stress during homocysteine exposure enhanced IKCa and SKCa currents, associated with improved EDHF-type response and channel activator-induced relaxation. Homocysteine did not alter whole-cell protein levels of IKCa and SKCa whereas lowered surface expressions of these channels, which were restored by ER stress inhibition. CONCLUSIONS: Homocysteine induces endothelial dysfunction through a mechanism involving ER stress-mediated suppression of IKCa and SKCa channels. Inhibition of cell surface expression of these channels by ER stress is, at least partially, responsible for the suppressive effect of homocysteine on the channel function. This study provides new mechanistic insights into homocysteine-induced endothelial dysfunction and advances our knowledge of the significance of ER stress in vascular disorders.

Floating growth of large-scale freestanding TiO2 nanorod films at the gas-liquid interface for additive-free Li-ion battery applications.

The floating growth process of large-scale freestanding TiO2 nanorod films at the gas-liquid interface was investigated. On the basis of the experiments, a self-templated growth scenario was developed to account for the self-assembly process. In the scenario, titanium complexes function not only as the Ti source for the growth of TiO2 but also as a soft template provider for the floating growth. According to the scenario, several new recipes of preparing freestanding TiO2 nanorod films at the gas-liquid interface were developed. The freestanding film was applied to a lithium ion battery as a binder-free and conducting agent-free anode, and good cyclability was obtained. This work may pave a new way to floating and freestanding TiO2 and other semiconductor materials, which has great potential not only in basic science but also in the applications such as materials engineering, Li-ion battery, photocatalyst, dye-sensitized solar cell, and flexible electronics.

Organohalide lead perovskite based photodetectors with much enhanced performance.

CH3NH3PbI3 based photodetectors were fabricated by a facile low-cost process with much enhanced performance. The rise time changed from 2.7 s to 0.02 s, the decay time from 0.5 s to 0.02 s, and the ON/OFF ratio tripled with improved stability. The results indicate that perovskites are promising light-harvesting materials for photodetectors.