Successful Use of Bortezomib for Recurrent Progressive Familial Intrahepatic Cholestasis Type II After Liver Transplantation: A Pediatric Case with a 9-Year Follow-Up.

Recurrence of progressive familial intrahepatic cholestasis (PFIC) type II poses challenges during postoperative liver transplant care. Posttransplant patients with PFIC type II risk developing recurrent cholestasis with normal gamma-glutamyl transferase activity, which mimics the original bile salt export pump (BSEP) protein deficiency and is related to a form of immunoglobulin G antibody (anti-BSEP)-mediated rejection. Bortezomib effectively induces apoptosis of actively antibody-producing plasma cells that may have a role in antibody-mediated rejection. In this case, we used bortezomib to treat PFIC type II recurrence after liver transplantation in a child.

Understanding the molecular mechanism of pathogenic variants of BIR2 domain in XIAP-deficient inflammatory bowel disease.

X-linked inhibitor of apoptosis protein (XIAP) deficiency causes refractory inflammatory bowel disease. The XIAP protein plays a pivotal role in the pro-inflammatory response through the nucleotide-binding oligomerization domain-containing signaling pathway that is important in mucosal homeostasis. We analyzed the molecular mechanism of non-synonymous pathogenic variants (PVs) of XIAP BIR2 domain. We generated N-terminally green fluorescent protein-tagged XIAP constructs of representative non-synonymous PVs. Co-immunoprecipitation and fluorescence cross-correlation spectroscopy showed that wild-type XIAP and RIP2 preferentially interacted in live cells, whereas all non-synonymous PV XIAPs failed to interact properly with RIP2. Structural analysis showed that various structural changes by mutations, such as hydrophobic core collapse, Zn-finger loss, and spatial rearrangement, destabilized the two loop structures (174-182 and 205-215) that critically interact with RIP2. Subsequently, it caused a failure of RIP2 ubiquitination and loss of protein deficiency by the auto-ubiquitination of all XIAP mutants. These findings could enhance our understanding of the role of XIAP mutations in XIAP-deficient inflammatory bowel disease and may benefit future therapeutic strategies.

Assessment of pathogens and risk factors associated with bloodstream infection in the year after pediatric liver transplantation.

BACKGROUND: Bloodstream infection (BSI) is one of the most significantly adverse events that can occur after liver transplantation (LT) in children. AIM: To analyze the profile of BSI according to the postoperative periods and assess the risk factors after pediatric LT. METHODS: Clinical data, collected from medical charts of children (n = 378) who underwent primary LT, were retrospectively reviewed. The primary outcome considered was BSI in the first year after LT. Univariate and multivariate analyses were performed to identify risk factors for BSI and respective odds ratios (ORs). RESULTS: Of the examined patients, 106 (28%) experienced 162 episodes of pathogen-confirmed BSI during the first year after LT. There were 1.53 ± 0.95 episodes per children (mean ± SD) among BSI-complicated patients with a median onset of 0.4 mo post-LT. The most common pathogenic organisms identified were Coagulase-negative staphylococci, followed by Enterococcus spp. and Streptococcus spp. About half (53%) of the BSIs were of unknown origin. Multivariate analysis demonstrated that young age (≤ 1.3 year; OR = 2.1, P = 0.011), growth failure (OR = 2.1, P = 0.045), liver support system (OR = 4.2, P = 0.008), and hospital stay of > 44 d (OR = 2.3, P = 0.002) were independently associated with BSI in the year after LT. CONCLUSION: BSI was frequently observed in patients after pediatric LT, affecting survival outcomes. The profile of BSI may inform clinical treatment and management in high-risk children after LT.

Clinical characteristics of neonatal cholestasis in a tertiary hospital and the development of a novel prediction model for mortality.

BACKGROUND: Few studies have described the aetiologies of neonatal cholestasis, and the overall neonatal cholestasis-related mortality (NCM) rate is unclear. We investigated the aetiology and outcome of neonatal cholestasis in a tertiary hospital and developed an NCM prediction model for these patients. METHODS: Patients aged <100 days with serum direct bilirubin (DB) levels of >1.0 mg/dL were retrospectively screened. Diagnostic and laboratory data during the 8-week follow-up period after enrolment between 2005 and 2020 were extracted digitally, and medical charts were reviewed manually by clinicians. Logistic regression was used to derive a prediction model for the 1-year mortality outcome of neonatal cholestasis, and performance evaluation and external validation were conducted for the NCM prediction model. FINDINGS: We enrolled 4028 neonates with DB of >1.0 mg/dL at least once. Prematurity and birth injury (35.4%), complex heart anomalies (18.6%), liver diseases (11.4%), and gastrointestinal anomalies (9.2%) were the most common aetiologies; 398 (9.9%) patients died before one year of age. The peak value of DB was positively correlated to the 1-year mortality rate. In the multivariate analysis, simple laboratory indices, including platelet, prothrombin time, aspartate aminotransferase, albumin, direct bilirubin, creatinine, and C-reactive protein, were independent predictors of 1-year mortality outcome of complete-case subjects. Using these laboratory indices, a logistic regression-based NCM prediction model was constructed. It showed acceptable performances on discrimination (area under the curve, 0.916), calibration (slope, 1.04) and Brier scoring (0.072). The external validation of the sample (n = 920) from two other centres also revealed similar performance profiles of the NCM model. INTERPRETATION: Various aetiologies of neonatal cholestasis were identified in a tertiary hospital, resulting in unfavourable outcomes of a large proportion. The NCM prediction model may have the potential to help clinicians to be aware of high-risk neonatal cholestasis. FUNDING: Ministry of Health & Welfare, Republic of Korea.

The Knockdown of TREK-1 in Hippocampal Neurons Attenuate Lipopolysaccharide-Induced Depressive-Like Behavior in Mice.

TWIK-related potassium channel-1 (TREK-1) is broadly expressed in the brain and involved in diverse brain diseases, such as seizures, ischemia, and depression. However, the cell type-specific roles of TREK-1 in the brain are largely unknown. Here, we generated a Cre-dependent TREK-1 knockdown (Cd-TREK-1 KD) transgenic mouse containing a gene cassette for Cre-dependent TREK-1 short hairpin ribonucleic acid to regulate the cell type-specific TREK-1 expression. We confirmed the knockdown of TREK-1 by injecting adeno-associated virus (AAV) expressing Cre into the hippocampus of the mice. To study the role of hippocampal neuronal TREK-1 in a lipopolysaccharide (LPS)-induced depression model, we injected AAV-hSyn-BFP (nCTL group) or AAV-hSyn-BFP-Cre (nCre group) virus into the hippocampus of Cd-TREK-1 KD mice. Interestingly, the immobility in the tail suspension test after LPS treatment did not change in the nCre group. Additionally, some neurotrophic factors (BDNF, VEGF, and IGF-1) significantly increased more in the nCre group compared to the nCTL group after LPS treatment, but there was no difference in the expression of their receptors. Therefore, our data suggest that TREK-1 in the hippocampal neurons has antidepressant effects, and that Cd-TREK-1 KD mice are a valuable tool to reveal the cell type-specific roles of TREK-1 in the brain.

A Silyl-Nickel Moiety as a Metal-Ligand Cooperative Site.

Nickel(II) complexes supported by a diphosphinosilyl ligand, [PhSi(2-PiPr2C6H4)2]- (PhSiP2), reveal unusual metal-ligand cooperativity (MLC). While (PhSiP2)Ni(NHMes) (2a) was cleanly isolated at room temperature, a nickel triisopropylphenylamido species, (PhSiP2)Ni(NHTrip) (2b), slowly transformed into a nickel(II) phenyl species, [(ArNH)SiP2]Ni(Ph) (3b), where (ArNH)SiP2- = [(NHTrip)Si(2-PiPr2C6H4)2]-. The X-ray crystallographic data of 3b exhibit a Si-N bond generated from Si-N coupling between the silyl moiety and amino group, along with cleavage of a Si-C bond. Because substoichiometric amounts of π-acidic ligands, such as isocyanide, enhance the conversion rate of 2 to 3 (kobs = 0.28 vs 0.44 h-1), this reaction may involve reductive elimination (RE) and oxidative addition (OA) operating at the silyl-nickel moiety. This is further supported by the fact that the presence of excess π-acidic ligands results in the generation of demetalated ligands (ArNH)PhSiP2 (4) having both Si-N and Si-Ph bonds and the nickel(0) species. Theoretical evaluations also agree on such a pathway. Interestingly, the reaction of a nickel phenyl species (3) with gaseous carbon dioxide (CO2(g)) produces a nickel(II) carbamato complex, (PhSiP2)Ni(OC(O)NHAr) (6), which may involve a RE-OA process occurring at a nickel center. Although 2 and 3 might be in equilibrium, the reaction of 3 with CO2 does not follow this pathway. Instead, a CO2 interaction induces RE at the silyl-nickel moiety, followed by amide group transfer, to give a carbamato product, 6, based on our experimental and theoretical evaluations. These results highly support that group transfer involving MLC can be managed via a RE-OA pathway at the silyl-nickel(II) moiety.

Central nervous system vasculitis from Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorder in children: A case report.

BACKGROUND: Epstein-Barr virus-associated T/natural killer-cell lymphoproliferative disorders (EBV-T/NK-LPD) is a group of rare disorders resulting from EBV-infected T/NK-cells. It manifests as a broad spectrum of clinical symptoms according to immunologic status and viral load of an infected patient. Here, we report a boy who developed central nervous system (CNS) vasculitis and myelopathy as possible neurologic manifestations of EBV-T/NK-LPD. CASE REPORT: A 16-year-old boy came to our hospital with a necrotic skin lesion on his right shoulder. He suffered from local skin reactions with high fevers after mosquito bites since he was 10 years old. During the evaluation of his skin lesion, he suddenly developed left facial palsy. Brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) showed acute infarctions of the pons and middle cerebellar peduncle and irregularities of both anterior inferior cerebellar arteries. Serologic testing showed an elevation of total Ig E levels, anti-VCA IgG levels, and anti-EA IgG titers. EBV DNA copy numbers of the whole blood and cerebrospinal fluid (CSF) were elevated. Biopsy of the right shoulder skin showed extranodal NK/T-cell lymphoma. According to clinical features and laboratory findings, he was diagnosed with EBV-T/NK-LPD. He was treated with chemotherapy and hematopoietic stem cell transplantation but developed recurrent infarctions during treatment. CONCLUSION: This case showed the diagnostic challenge of neurologic manifestations of EBV-T/NK-LPD. EBV-T/NK-LPD-associated CNS vasculitis needs to be considered as a differential diagnosis of CNS vasculitis, when it is accompanied by the typical clinical spectrum of EBV-T/NK-LPD such as severe mosquito bite allergy, extranodal NK/T-cell lymphoma.

The E3 ubiquitin ligase, NEDD4L (NEDD4-2) regulates bestrophin-1 (BEST1) by ubiquitin-dependent proteolysis.

The bestrophin family comprises well-known Ca2+-activated chloride channels (CaCC) that are expressed in a variety tissues including the brain, eye, gastrointestinal tract, and muscle tissues. Among the family members, bestrophin-1 (BEST1) is known to exist mainly in retinal pigment epithelium cells, but we recently reported that BEST1 mediates Ca2+-activated Cl- currents in hippocampal astrocytes. Despite its critical roles in physiological processes, including tonic γ-aminobutyric acid release and glutamate transport, the mechanisms that regulate BEST1 are poorly understood. In this study, we identified NEDD4L (NEDD4-2), an E3 ubiquitin ligase, as a binding partner of BEST1. A series of deletion constructs revealed that the WW3-4 domains of NEDD4L were important for interaction with BEST1. We observed that BEST1 underwent ubiquitin-dependent proteolysis and found that the conserved lysine370 residue in the C-terminus of BEST1 was important for its ubiquitination. Finally, we demonstrated that NEDD4L inhibited whole cell currents mediated by BEST1 but not by the BEST1(K370R) mutant. Collectively, our data demonstrated that NEDD4L played a critical role in regulating the surface expression of BEST1 by promoting its internalization and degradation.

Physicochemical and in vitro digestion characteristics of size-different red ginseng powders.

The aims of the present study were to prepare different-sized red ginseng powders and investigate the particle size effect on the release property of ginsenosides in in vitro digestion conditions. Ultrafine powder showed bimodal particle size distribution with a large peak at around 100 µm and small peak at around 10 µm, differently from fine powder showing unimodal distribution at 100 µm. The specific surface areas of fine- and ultrafine powders were 48.72 ± 6.41 and 86.74 ± 5.96 m2/g, respectively. Time-dependent release property of the powders in the simulated gastrointestinal fluids was determined by quantifying ginsenoside Rg1 released. The initial and final concentrations of ginsenoside Rg1 released was higher in ultrafine powder than fine one. It is expected that particle size reduction and corresponding increase in the specific surface area have a potential to improve the release of ginsenosides in the gastrointestinal tract and enhance the chances to be absorbed in human body.

A P-P Bond as a Redox Reservoir and an Active Reaction Site.

The carbonylation of a nickel(II) anilido species 2 led to the formation of a dinickel(0)-CO complex (P2 P-PP2 ){Ni(CO)}2 3 with a P-P bond along with isocyanate generation. In this reaction, the central phosphide moiety of an anionic PPP ligand (PPP- =- P[2-Pi Pr2 C6 H4 ]2 ) acts as a single-electron donor to form a P radical. Alternatively, 3 can be synthesized from the reduction of (PPP)NiCl (1) in the presence of CO; thus, the reaction proceeds by radical coupling of a . P-Ni0 -CO species. The reverse reaction occurred to generate 1 when 3 was treated with AgCl. Since the P-P bond is light-sensitive, its homolysis is possible and was explored by EPR spectroscopy and DFT analysis. Finally, various bond-activation reactions of 3 occurred under visible-light conditions, thus indicating that a P-P bond can act as an active reaction site.

Selective Transformation of CO2 to CO at a Single Nickel Center.

Carbon dioxide conversion mediated by transition metal complexes continues to attract much attention because of its future potential utilization as a nontoxic and inexpensive C1 source for the chemical industry. Given the presence of nickel in natural systems that allow for extremely efficient catalysis, albeit in an Fe cluster arrangement, studies that focus on selective CO2 conversion with synthetic nickel species are currently of considerable interest in our group. In this Account, the selective conversion of CO2 to carbon monoxide occurring at a single nickel center is discussed. The chemistry is based on a series of related nickel pincer complexes with attention to the uniqueness of the coordination geometry, which is crucial in allowing for particular reactivity toward CO2. Our research is inspired by the efficient enzymatic CO2 catalysis occurring at the active site of carbon monoxide dehydrogenase. Since the binding and reactivity toward CO2 are controlled in part by the geometry of a L3Ni scaffold, we have explored the chemistry of low-valent nickel supported by PPMeP and PNP ligands, in which a pseudotetrahedral or square-planar geometry is accommodated. Two isolated nickel-CO2 adducts, (PPMeP)Ni(η2-CO2-κ C) (2) and {Na(12-C-4)2}{(PNP)Ni(η1-CO2-κ C)} (7), clearly demonstrate that the geometry of the nickel ion is crucial in the binding of CO2 and its level of activation. In the case of a square-planar nickel center supported by a PNP ligand, a series of bimetallic metallacarboxylate Ni-µ-CO2-κ C, O-M species (M = H, Na, Ni, Fe) were synthesized, and their structural features and reactivity were studied. Protonation cleaves the C-O bond, resulting in the formation of a nickel(II) monocarbonyl complex. By sequential reduction, the corresponding mono- and zero-valent Ni-CO species were produced. The reactivities of three nickel carbonyl species toward various iodoalkanes and CO2 were explored to address whether their corresponding reactivities could be controlled by the number of valence d electrons. In particular, a (PNP)Ni(0)-CO species (13) shows immediate reactivity toward CO2 but displays multiple product formation. By incorporation of a -CMe2- bridging unit, a structurally rigidified acriPNP ligand was newly designed and produced. This ligand modification was successful in preparing the T-shaped nickel(I) metalloradical species 9 exhibiting open-shell reactivity due to the sterically exposed nickel center possessing a half-filled d x2- y2 orbital. More importantly, the selective addition of CO2 to a nickel(0)-CO species was enabled to afford a nickel(II)-carboxylate species (22) with the expulsion of CO(g). Finally, the (acriPNP)Ni system provides a synthetic cycle in the study of the selective conversion of CO2 to CO that involves two-electron reduction of Ni-CO followed by the direct addition of CO2 to release the coordinated CO ligand.

σ-Complexation as a strategy for designing copper-based light emitters.

Strongly emissive cuprous complexes containing a stable σ-SiH-Cu motif were prepared. These complexes serve as a proof of principle that σ-complexation can be utilized as a design principle for engineering responsive light emitting materials. Their excited state lifetimes were found to be long (∼20 µs) with high quantum yields (φ = 0.40-0.59).

Influence of autoclave treatment and enzymatic hydrolysis on the antioxidant activity of Opuntia ficus-indica fruit extract.

The objectives of this study were to obtain Opuntia ficus-indica fruit (OFIF) extract by autoclave treatment, to convert the flavonoid glycosides in the autoclave extract (AE) to aglycones by enzymatic hydrolysis, and to compare the antioxidant activity of AE and OFIF extracts obtained by other conventional methods. It was revealed that the total polyphenol and flavonoid content and antioxidant activity of AE were higher than those of water extract but were a slightly lower than those of ethanol extract, which indicates that autoclave treatment might be an efficient extraction method for OFIF. Moreover, it was confirmed that the conversion of various flavonoid glycosides to aglycones in all the OFIF extracts does not significantly affect the antioxidant activities. Therefore, it is extrapolated that the antioxidant activity might be correlated to the intestinal absorption rates and metabolic pathway induction upon oral administration rather than the structure of compound itself.

Effect of frozen-storage period on quality of American sirloin and mackerel (Scomber japonicus).

This study aimed to study the effect of frozen-storage period on the quality of sirloin and mackerel (Scomber japonicus). The samples were evaluated after being kept in frozen storage at -17.9 °C for different periods of time (1, 8, 15, 22, and 29 days). The frozen storage resulted in increase in ice crystal formation on the surface of both sirloin and mackerel. Frozen-storage period had an effect on the increase in the drip loss of both sirloin and mackerel with a positive correlation (p < 0.05) as well as on the decrease in the hardness of sirloin with a negative correlation (p < 0.05). During the frozen-storage period, the 2-thiobarbituric acid reactive substance level was increased in mackerel while the level in sirloin was maintained; both levels were within safe limits. Consequently, a 29-day freezing period is postulated to have little effect on the quality of sirloin and mackerel.

Phosphinite-Ni(0) mediated formation of a phosphide-Ni(II)-OCOOMe species via uncommon metal-ligand cooperation.

Reversible transformations are observed between a phosphide-nickel(II) alkoxide and a phosphinite-nickel(0) species via a P-O bond formation coupled with a 2-e(-) redox change at the nickel center. In the forward reaction, the nickel(0) dinitrogen species (PP(OMe)P)Ni(N2) (2) and {(PP(OMe)P)Ni}2(µ-N2) (3) were formed from the reaction of (PPP)NiCl (1) with a methoxy anion. In the backward reaction, a (PPP)Ni(II) moiety was regenerated from the CO2 reaction of 3 with the concomitant formation of a methyl carbonate ligand in (PPP)Ni(OCOOMe) (7). Thus, unanticipated metal-ligand cooperation involving a phosphide based ligand is reported.

Highly regio- and stereoselective synthesis of boron-substituted enynes via copper-catalyzed borylation of conjugated diynes.

A mild copper-catalyzed regio- and stereoselective monoborylation of conjugated diynes with bis(pinacolato)diboron that affords enynylboronates is reported. The reaction is efficient for different types of conjugated diynes including unsymmetrical diynes and produces enynylboron compounds with high and complementary regioselectivity compared with classical hydrometalation reactions. In particular, the reactions of internal conjugated diynes with a silyl substitution produced highly functionalized enynes with high regio- and stereoselectivity, which can be used in further transformations.

Regioselective synthesis of highly functionalized alkenylboronates by Cu-catalyzed borylation of propargylic silylalkynes.

High regioselectivity was achieved in the Cu(i)-catalyzed borylation of internal propargylic alkynes with a silyl substituent to afford multifunctionalized alkenylboron compounds. While both the silyl and propargylic substituents are known to act as directing groups, a N-heterocyclic carbene (NHC)-Cu complex furnished ß-vinylboronate products (relative to Si) with high selectivity.

Formation of a nickel carbon dioxide adduct and its transformation mediated by a Lewis acid.

An uncommon nickel dinitrogen adduct and its tendency toward CO2 binding are investigated using a (PP(Me)P)Ni scaffold. (PP(Me)P)Ni(N2) (1) and {(PP(Me)P)Ni}2(µ-N2) (2) were prepared and their treatment with CO2 revealed the formation of (PP(Me)P)Ni(η(2)-CO2) (3). This is a new type of CO2 binding for a zero-valent nickel center supported by three donor ligands, reminiscent of the CODH active site environment. Clear unique structural differences in 3 are evident when compared with previous 4-coordinate Ni-CO2 adducts. Compound 3 when treated with B(C6F5)3 gives the Lewis acid-base adduct (PP(Me)P)Ni{COOB(C6F5)3} (4) possessing a Ni-µ-CO2-κ(2)C,O-B moiety.

20-O-ß-D-glucopyranosyl-20(S)-protopanaxadiol-fortified ginseng extract attenuates the development of atopic dermatitis-like symptoms in NC/Nga mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng and ginsenosides are frequently used in the treatment of chronic inflammatory diseases. Recently, 20-O-ß-d-glucopyranosyl-20(S)-protopanaxadiol (GPD), the main metabolite of ginsenosides, was reported to have both anti-allergic and anti-pruritic effects. The immunomodulatory effects of GPD-fortified ginseng extract (GFGE) on atopic dermatitis (AD)-like symptoms in mice were investigated. This study was designed to investigate the preventive effect of GFGE on AD-like symptoms. MATERIALS AND METHODS: The effects of orally administered GFGE on Dermatophagoides farinae body extract (DFE)-induced AD-like symptoms in NC/Nga mice were assessed by analyzing dermatitis score, ear thickness, scratching time, skin histological changes, and serum level of macrophage-derived chemokine (MDC). In addition, splenocytes were isolated from the mice and stimulated with anti-CD3 and anti-CD28 monoclonal antibodies to produce cytokines. RESULTS: Oral administration of GFGE significantly attenuated DFE-induced increases in dermatitis score, ear thickness, scratching time, and severity of skin lesions in NC/Nga mice. GFGE treatment also reduced level of MDC in serum, infiltration of eosinophils and mast cells in skin, and production of cytokines in splenocytes. CONCLUSIONS: These results suggest that GFGE might ameliorate DFE-induced AD-like symptoms and be an alternative therapeutic agent for the prevention of AD.