Identification of G protein-coupled receptor 55 (GPR55) as a target of curcumin.

The identification of molecular targets of bioactive food components is important to understand the mechanistic aspect of their physiological functions. Here, we have developed a screening system that enables us to determine the activation of G protein-coupled receptors (GPCRs) by food components and have identified GPR55 as a target for curcumin. Curcumin activated GPR55 and induced serum-response element- and serum-response factor-mediated transcription, which were inhibited by Rho kinase and GPR55 antagonists. Both the methoxy group and the heptadienone moiety of curcumin were required for GPR55 activation. The F1905.47 residue of GPR55 was important for the interaction with curcumin. The curcumin-induced secretion of glucagon-like peptide-1 in GLUTag cells was inhibited by a GPR55 antagonist. These results indicate that expression screening is a useful system to identify GPCRs as targets of food components and strongly suggest that curcumin activates GPR55 as an agonist, which is involved in the physiological function of curcumin.

Curcumin activates G protein-coupled receptor 97 (GPR97) in a manner different from glucocorticoid.

Curcumin is a yellow pigment in turmeric (Curcuma longa) with various physiological effects in the body. To elucidate the molecular mechanisms by which bioactive compounds exert their function, identification of their molecular targets is crucial. In this study, we show that curcumin activates G protein-coupled receptor 97 (GPR97). Curcumin dose-dependently activated serum-response element-, but not serum-response factor-response element-, nuclear factor of activated T-cell-response element-, or cAMP-response element-, mediated transcription in cells overexpressed with GPR97. The structure-activity relationship indicated that (i) the double-bonds of the central 7-carbon chain were essential for activation; (ii) a methoxy group on the aromatic ring was required for maximal activity; (iii) the addition of glucuronic acid moiety or a methoxy group to the aromatic ring, but not the methylation of the aromatic p-hydroxy group, eliminated the activity; (iv) the stability of curcumin would be related to receptor activation. Both mutant GPR97(T250A) lacking the cleavage at GPCR proteolysis site and mutant GPR97(ΔN) lacking the N-terminal extracellular region were activated by curcumin and its related compounds similar to wild-type GPR97. In contrast, the synthetic glucocorticoid beclomethasone dipropionate and l-Phe activated wild-type GPR97 and GPR97(T250A), but not GPR97(ΔN). Moreover, curcumin exerted an additive effect on the activation of wild-type GPR97 with beclomethasone dipropionate, but not with l-Phe. Taken together, these results indicate that curcumin activates GPR97 coupled to Gi/Go subunit, and suggest that curcumin and glucocorticoid activate GPR97 in a different manner.

A Curcumin Degradation Product, 7-Norcyclopentadione, Formed by Aryl Migration and Loss of a Carbon from the Heptadienedione Chain.

Evidence that anti-inflammatory and other biological effects of curcumin may at least in part be mediated by its metabolites underscores the importance of identifying novel transformation products. Spontaneous degradation of curcumin in buffer pH 7.5 results mainly in dioxygenated products with a characteristic cyclopentadione ring composed of carbons 2 through 6 of the former heptadienedione chain. When analyzing degradation reactions of 4'- O-methylcurcumin, a product was identified missing one of the terminal carbons of the heptadienedione moiety while containing a cyclopentadione ring and adjacent hydroxy group typical of curcumin degradation products. Analysis of curcumin autoxidation reactions showed formation of an analogous compound, 7-norcyclopentadione, a degradation product exhibiting net loss of a carbon and gain of an oxygen atom. Removal of the carbon is proposed to occur via a peroxide-linked curcumin dimer in conjunction with radical-mediated 1,2-aryl migration of a guaiacol moiety. Oxidation reactions of demethoxycurcumin gave demethoxy-7-norcyclopentadione, whereas an analogous product was not observed from bis-demethoxycurcumin. Incubation of RAW264.7 macrophage-like cells with curcumin showed the presence of 7-norcyclopentadione, the formation of which was not increased upon activation of the cells with 12- O-tetradecanoylphorbol-13-acetate . 7-Norcyclopentadione is a novel type of degradation product that is most likely formed via autoxidative processes when cells are incubated with curcumin.

Stability and anti-inflammatory activity of the reduction-resistant curcumin analog, 2,6-dimethyl-curcumin.

The efficacy of the curry spice compound curcumin as a natural anti-inflammatory agent is limited by its rapid reductive metabolism in vivo. A recent report described a novel synthetic derivative, 2,6-dimethyl-curcumin, with increased stability against reduction in vitro and in vivo. It is also known that curcumin is unstable at physiological pH in vitro and undergoes rapid autoxidative transformation. Since the oxidation products may contribute to the biological effects of curcumin, we tested oxidative stability of 2,6-dimethyl-curcumin in buffer (pH 7.5). The rate of degradation was similar to curcumin. The degradation products were identified as a one-carbon chain-shortened alcohol, vanillin, and two isomeric epoxides that underwent cleavage to vanillin and a corresponding hydroxylated cleavage product. 2,6-Dimethyl-curcumin was more potent than curcumin in inhibiting NF-κB activity but less potent in inhibiting expression of cyclooxygenase-2 in LPS-activated RAW264.7 cells. 2,6-Dimethyl-curcumin and some of its degradation products covalently bound to a peptide that contains the redox-sensitive cysteine of IKKß kinase, the activating kinase upstream of NF-κB, providing a mechanism for the anti-inflammatory activity. In RAW264.7 cells vanillin, the chain-shortened alcohol, and reduced 2,6-dimethyl-curcumin were detected as major metabolites. These studies provide new insight into the oxidative transformation mechanism of curcumin and related compounds. The products resulting from oxidative transformation contribute to the anti-inflammatory activity of 2,6-dimethyl-curcumin in addition to its enhanced resistance against enzymatic reduction.

The anti-inflammatory activity of curcumin is mediated by its oxidative metabolites.

The spice turmeric, with its active polyphenol curcumin, has been used as anti-inflammatory remedy in traditional Asian medicine for centuries. Many cellular targets of curcumin have been identified, but how such a wide range of targets can be affected by a single compound is unclear. Here, we identified curcumin as a pro-drug that requires oxidative activation into reactive metabolites to exert anti-inflammatory activities. Synthetic curcumin analogs that undergo oxidative transformation potently inhibited the pro-inflammatory transcription factor nuclear factor κB (NF-κB), whereas stable, non-oxidizable analogs were less active, with a correlation coefficient (R2) of IC50versus log of autoxidation rate of 0.75. Inhibition of glutathione biosynthesis, which protects cells from reactive metabolites, increased the potency of curcumin and decreased the amount of curcumin-glutathione adducts in cells. Oxidative metabolites of curcumin adducted to and inhibited the inhibitor of NF-κB kinase subunit ß (IKKß), an activating kinase upstream of NF-κB. An unstable, alkynyl-tagged curcumin analog yielded abundant adducts with cellular protein that were decreased by pretreatment with curcumin or an unstable analog but not by a stable analog. Bioactivation of curcumin occurred readily in vitro, which may explain the wide range of cellular targets, but if bioactivation is insufficient in vivo, it may also help explain the inconclusive results in human studies with curcumin so far. We conclude that the paradigm of metabolic bioactivation uncovered here should be considered for the evaluation and design of clinical trials of curcumin and other polyphenols of medicinal interest.

Kaempferol increases levels of coenzyme Q in kidney cells and serves as a biosynthetic ring precursor.

Coenzyme Q (Q) is a lipid-soluble antioxidant essential in cellular physiology. Patients with Q deficiencies, with few exceptions, seldom respond to treatment. Current therapies rely on dietary supplementation with Q10, but due to its highly lipophilic nature, Q10 is difficult to absorb by tissues and cells. Plant polyphenols, present in the human diet, are redox active and modulate numerous cellular pathways. In the present study, we tested whether treatment with polyphenols affected the content or biosynthesis of Q. Mouse kidney proximal tubule epithelial (Tkpts) cells and human embryonic kidney cells 293 (HEK 293) were treated with several types of polyphenols, and kaempferol produced the largest increase in Q levels. Experiments with stable isotope 13C-labeled kaempferol demonstrated a previously unrecognized role of kaempferol as an aromatic ring precursor in Q biosynthesis. Investigations of the structure-function relationship of related flavonols showed the importance of two hydroxyl groups, located at C3 of the C ring and C4' of the B ring, both present in kaempferol, as important determinants of kaempferol as a Q biosynthetic precursor. Concurrently, through a mechanism not related to the enhancement of Q biosynthesis, kaempferol also augmented mitochondrial localization of Sirt3. The role of kaempferol as a precursor that increases Q levels, combined with its ability to upregulate Sirt3, identify kaempferol as a potential candidate in the design of interventions aimed on increasing endogenous Q biosynthesis, particularly in kidney.

Complete versus culprit-only revascularisation in ST elevation myocardial infarction with multi-vessel disease.

BACKGROUND: Multi-vessel coronary disease in people with ST elevation myocardial infarction (STEMI) is common and is associated with worse prognosis after STEMI. Based on limited evidence, international guidelines recommend intervention on only the culprit vessel during STEMI. This, in turn, leaves other significantly stenosed coronary arteries for medical therapy or revascularisation based on inducible ischaemia on provocative testing. Newer data suggest that intervention on both the culprit and non-culprit stenotic coronary arteries (complete intervention) may yield better results compared with culprit-only intervention. OBJECTIVES: To assess the effects of early complete revascularisation compared with culprit vessel only intervention strategy in people with STEMI and multi-vessel coronary disease. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, World Health Organization International Clinical Trials Registry Platform Search Portal, and ClinicalTrials.gov. The date of the last search was 4 January 2017. We applied no language restrictions. We handsearched conference proceedings to December 2016, and contacted authors and companies related to the field. SELECTION CRITERIA: We included only randomised controlled trials (RCTs), wherein complete revascularisation strategy was compared with a culprit-only percutaneous coronary intervention (PCI) for the treatment of people with STEMI and multi-vessel coronary disease. DATA COLLECTION AND ANALYSIS: We assessed the methodological quality of each trial using the Cochrane 'Risk of bias' tool. We resolved the disagreements by discussion among review authors. We followed standard methodological approaches recommended by Cochrane. The primary outcomes were long-term (one year or greater after the index intervention) all-cause mortality, long-term cardiovascular mortality, long-term non-fatal myocardial infarction, and adverse events. The secondary outcomes were short-term (within the first 30 days after the index intervention) all-cause mortality, short-term cardiovascular mortality, short-term non-fatal myocardial infarction, revascularisation, health-related quality of life, and cost. We analysed data using fixed-effect models, and expressed results as risk ratios (RR) with 95% confidence intervals (CI). We used GRADE criteria to assess the quality of evidence and we conducted Trial Sequential Analysis (TSA) to control risks of random errors. MAIN RESULTS: We included nine RCTs, that involved 2633 people with STEMI and multi-vessel coronary disease randomly assigned to either a complete (n = 1381) versus culprit-only (n = 1252) revascularisation strategy. The complete and the culprit-only revascularisation strategies did not differ for long-term all-cause mortality (65/1274 (5.1%) in complete group versus 72/1143 (6.3%) in culprit-only group; RR 0.80, 95% CI 0.58 to 1.11; participants = 2417; studies = 8; I2 = 0%; very low quality evidence). Compared with culprit-only intervention, the complete revascularisation strategy was associated with a lower proportion of long-term cardiovascular mortality (28/1143 (2.4%) in complete group versus 51/1086 (4.7%) in culprit-only group; RR 0.50, 95% CI 0.32 to 0.79; participants = 2229; studies = 6; I2 = 0%; very low quality evidence) and long-term non-fatal myocardial infarction (47/1095 (4.3%) in complete group versus 70/1004 (7.0%) in culprit-only group; RR 0.62, 95% CI 0.44 to 0.89; participants = 2099; studies = 6; I2 = 0%; very low quality evidence). The complete and the culprit-only revascularisation strategies did not differ in combined adverse events (51/2096 (2.4%) in complete group versus 57/1990 (2.9%) in culprit-only group; RR 0.84, 95% CI 0.58 to 1.21; participants = 4086; I2 = 0%; very low quality evidence). Complete revascularisation was associated with lower proportion of long-term revascularisation (145/1374 (10.6%) in complete group versus 258/1242 (20.8%) in culprit-only group; RR 0.47, 95% CI 0.39 to 0.57; participants = 2616; studies = 9; I2 = 31%; very low quality evidence). TSA of long-term all-cause mortality, long-term cardiovascular mortality, and long-term non-fatal myocardial infarction showed that more RCTs are needed to reach more conclusive results on these outcomes. Regarding long-term repeat revascularisation more RCTs may not change our present result. The quality of the evidence was judged to be very low for all primary and the majority of the secondary outcomes mainly due to risk of bias, imprecision, and indirectness. AUTHORS' CONCLUSIONS: Compared with culprit-only intervention, the complete revascularisation strategy may be superior due to lower proportions of long-term cardiovascular mortality, long-term revascularisation, and long-term non-fatal myocardial infarction, but these findings are based on evidence of very low quality. TSA also supports the need for more RCTs in order to draw stronger conclusions regarding the effects of complete revascularisation on long-term all-cause mortality, long-term cardiovascular mortality, and long-term non-fatal myocardial infarction.

Oxidative metabolism of curcumin-glucuronide by peroxidases and isolated human leukocytes.

Conjugation with glucuronic acid is a prevalent metabolic pathway of orally administrated curcumin, the bioactive diphenol of the spice turmeric. The major in vitro degradation reaction of curcumin is autoxidative transformation resulting in oxygenation and cyclization of the heptadienedione chain to form cyclopentadione derivatives. Here we show that curcumin-glucuronide is much more stable than curcumin, degrading about two orders of magnitude slower. Horseradish peroxidase-catalyzed oxidation of curcumin-glucuronide occurred at about 80% of the rate with curcumin, achieving efficient transformation. Using LC-MS and NMR analyses the major products of oxidative transformation were identified as glucuronidated bicyclopentadione diastereomers. Cleavage into vanillin-glucuronide accounted for about 10% of the products. Myeloperoxidase and lactoperoxidase oxidized curcumin-glucuronide whereas tyrosinase and xanthine oxidase were not active. Phorbol ester-activated primary human leukocytes showed increased oxidative transformation of curcumin-glucuronide which was inhibited by the peroxidase inhibitor sodium azide. These studies provide evidence that the glucuronide of curcumin is not an inert product and may undergo further enzymatic and non-enzymatic metabolism. Oxidative transformation by leukocyte myeloperoxidase may represent a novel metabolic pathway of curcumin and its glucuronide conjugate.

Extreme confinement of xenon by cryptophane-111 in the solid state.

Solids that sorb, capture and/or store the heavier noble gases are of interest because of their potential for transformative rare gas separation/production, storage, or recovery technologies. Herein, we report the isolation, crystal structures, and thermal stabilities of a series of xenon and krypton clathrates of (±)-cryptophane-111 (111). One trigonal crystal form, Xe@111⋅y(solvent), is exceptionally stable, retaining xenon at temperatures of up to about 300 °C. The high kinetic stability is attributable not only to the high xenon affinity and cage-like nature of the host, but also to the crystal packing of the clathrate, wherein each window of the molecular container is blocked by the bridges of adjacent containers, effectively imprisoning the noble gas in the solid state. The results highlight the potential of discrete molecule materials exhibiting intrinsic microcavities or zero-dimensional pores.

Rim-functionalized cryptophane-111 derivatives via heterocapping, and their xenon complexes.

Capping of cyclotriphenolene (3a) by the more available cyclotriguaiacylene (3c) or trisbromocyclotriphenolene (3b) gives the first rim-functionalized cryptophane-111 derivatives. Crystal structures of the xenon complexes reveal high cavity packing coefficients and unprecedentedly short Xe···C contacts.

Physician-directed heart failure transitional care program: a retrospective case review.

BACKGROUND: Despite a variety of national efforts to improve transitions of care for patients at risk for rehospitalization, 30-day rehospitalization rates for patients with heart failure have remained largely unchanged. METHODS: This is a retrospective review of 73 patients enrolled in our hospital-based, physican-directed Heart Failure Transitional Care Program (HFTCP). This study evaluated the 30- and 90- day readmission rates before and after enrollment in the program. The Transitionalist's services focused on bedside consultation prior to hospital discharge, follow-up home visits within 72 hours of discharge, frequent follow-up phone calls, disease-specific education, outpatient intravenous diuretic therapy, and around-the-clock telephone access to the Transitionalist. RESULTS: The pre-enrollment 30-day readmission rates for acute decompensated heart failure (ADHF) and all-cause readmission was 26.0% and 28.8%, respectively, while the post-enrollment rates for ADHF and all-cause readmission were 4.1% (P < 0.001) and 8.2% (P = 0.002), respectively. The pre-enrollment 90-day all-cause and ADHF readmission rates were 69.8%, and 58.9% respectively, while the post-enrollment rates for all-cause and ADHF were 27.3% (P < 0.001) and 16.4% (P < 0.001) respectively. CONCLUSIONS: Our physician-implemented HFTCP reduced rehospitalization risk for patients enrolled in the program. This program may serve as a model to assist other hospital systems to reduce readmission rates of patients with HF.

Direct Telephonic Communication in a Heart Failure Transitional Care Program: An observational study.

BACKGROUND: This study investigated the trend of phone calls in the Banner Good Samaritan Medical Center (BGSMC) Heart Failure Transitional Care Program (HFTCP). The primary goal of the HFTCP is to reduce 30-Day readmissions for heart failure patients by using a multi-pronged approach. METHODS: This study included 104 patients in the HFTCP discharged over a 51-week period who had around-the-clock telephone access to the Transitionalist. Cellular phone records were reviewed. This study evaluated the length and timing of calls. RESULTS: A total of 4398 telephone calls were recorded of which 39% were inbound and 61% were outbound. This averaged to 86 calls per week. During the "Weekday Daytime" period, Eighty-five percent of the totals calls were made. There were 229 calls during the "Weekday Nights" period with 1.5 inbound calls per week. The "Total Weekend" calls were 10.2% of the total calls which equated to a weekly average of 8.8. CONCLUSIONS: Our experience is that direct, physician-patient telephone contact is feasible with a panel of around 100 HF patients for one provider. If the proper financial reimbursements are provided, physicians may be apt to participate in similar transitional care programs. Likewise, third party payers will benefit from the reduction in unnecessary emergency room visits and hospitalizations.

Assessment of Toll-like receptor-4 gene polymorphism on pyelonephritis and renal scar.

The aim of this study was to evaluate the effect of the TLR-4 gene TLR4 c.896A < G polymorphism on the development and clinical severity of urinary tract infections (UTI) and renal scar formations in children. The patients with first diagnosis of UTI (n = 112) and healthy controls (n = 93) were enrolled in the study. The TLR4 c.896A < G polymorphism was analysed in groups. The mean age of the patients in the study group was 8.1 ± 3.5 years and 9.2 ± 2.7 years for those in the control group. The TLR4 c.896A < G polymorphism was detected in 12.5% in the UTI group and in 15.1% of the control group. Forty patients showed pyelonephritis (PN) with scar tissue, 37 patients had PN without scars, and 35 patients had lower UTI. The TLR4 c.896A < G polymorphism was found in 22.5% of patients with scar-positive PN, and it was also present in 10.8% of patients with scar-negative PN and 2.9% of patients with lower UTI. We found higher TLR4 c.896A < G polymorphism and allelic frequency in patients with upper UTI compared to patients with lower UTI (P = 0.041 and P = 0.039, respectively). No significant difference was observed between patients and the control group for TLR-4 c.896A3. The TLR4 c.896A < G polymorphism and alleles were higher in patients with upper UTI than in patients with lower UTI. The TLR4 c.896A < G polymorphism frequency was nearly twice that in the scar-positive PN patients when compared to the scar-negative patients. Larger-scale studies involving larger numbers of patients should be performed.

A water-soluble Xe@cryptophane-111 complex exhibits very high thermodynamic stability and a peculiar (129)Xe NMR chemical shift.

The known xenon-binding (±)-cryptophane-111 (1) has been functionalized with six [(η(5)-C(5)Me(5))Ru(II)](+) ([Cp*Ru](+)) moieties to give, in 89% yield, the first water-soluble cryptophane-111 derivative, namely [(Cp*Ru)(6)1]Cl(6) ([2]Cl(6)). [2]Cl(6) exhibits a very high affinity for xenon in water, with a binding constant of 2.9(2) × 10(4) M(-1) as measured by hyperpolarized (129)Xe NMR spectroscopy. The (129)Xe NMR chemical shift of the aqueous Xe@[2](6+) species (308 ppm) resonates over 275 ppm downfield of the parent Xe@1 species in (CDCl(2))(2) and greatly broadens the practical (129)Xe NMR chemical shift range made available by xenon-binding molecular hosts. Single crystal structures of [2][CF(3)SO(3)](6)·xsolvent and 0.75H(2)O@1·2CHCl(3) reveal the ability of the cryptophane-111 core to adapt its conformation to guests.

Novel ATP6V1B1 and ATP6V0A4 mutations in autosomal recessive distal renal tubular acidosis with new evidence for hearing loss.

Autosomal recessive distal renal tubular acidosis (rdRTA) is characterised by severe hyperchloraemic metabolic acidosis in childhood, hypokalaemia, decreased urinary calcium solubility, and impaired bone physiology and growth. Two types of rdRTA have been differentiated by the presence or absence of sensorineural hearing loss, but appear otherwise clinically similar. Recently, we identified mutations in genes encoding two different subunits of the renal alpha-intercalated cell's apical H(+)-ATPase that cause rdRTA. Defects in the B1 subunit gene ATP6V1B1, and the a4 subunit gene ATP6V0A4, cause rdRTA with deafness and with preserved hearing, respectively. We have investigated 26 new rdRTA kindreds, of which 23 are consanguineous. Linkage analysis of seven novel SNPs and five polymorphic markers in, and tightly linked to, ATP6V1B1 and ATP6V0A4 suggested that four families do not link to either locus, providing strong evidence for additional genetic heterogeneity. In ATP6V1B1, one novel and five previously reported mutations were found in 10 kindreds. In 12 ATP6V0A4 kindreds, seven of 10 mutations were novel. A further nine novel ATP6V0A4 mutations were found in "sporadic" cases. The previously reported association between ATP6V1B1 defects and severe hearing loss in childhood was maintained. However, several patients with ATP6V0A4 mutations have developed hearing loss, usually in young adulthood. We show here that ATP6V0A4 is expressed within the human inner ear. These findings provide further evidence for genetic heterogeneity in rdRTA, extend the spectrum of disease causing mutations in ATP6V1B1 and ATP6V0A4, and show ATP6V0A4 expression within the cochlea for the first time.

Hemodiafiltration for vancomycin overdose in a patient with end-stage renal failure.

A 17-year-old anuric female patient with end-stage renal failure received a massive overdose of vancomycin and was treated with high-flux hemodiafiltration, as described in this report. The hemodiafiltration procedure with a polysulfone membrane was performed 3 times. The vancomycin concentration was decreased from 101 mg/l to 16.59 mg/l at the end of the procedure. No adverse effects were noted from either vancomycin or hemodiafiltration. Hemodiafiltration with a high-flux polysulfone membrane is a novel and safe treatment modality for vancomycin overdose in pediatric patients.