Furosemide clearance in very preterm neonates early in life: A pilot study using scavenged samples.

BACKGROUND: Furosemide is an off-label drug, frequently used as a diuretic in neonates with oliguria and/or edema. Its clearance in preterm neonates is lower than in term neonates or children. We aimed, herein, to clarify furosemide clearance (CL) in very preterm (VP) neonates (<28 weeks' gestation) within the first 2 weeks of life and identify the factors predictive of the pharmacokinetics (PK) parameters, such as CL. METHODS: Furosemide was administered at 0.5 or 1 mg/kg in a 0.5-h infusion via a syringe pump; blood samples were drawn from an artery or vein after the intravenous injection. The serum furosemide concentration was measured using high-performance liquid chromatography. The PK parameters were then analyzed using Bayesian estimation. RESULTS: Thirteen blood samples were obtained from 10 VP neonates after intravenous injection. The mean postconceptional age and mean postnatal days at exposure to furosemide were 26.9 weeks and 7.1 days, respectively. The estimated mean CL was 16.5 mL/kg/h. The mean distribution volume (Vd) and elimination half-life (t1/2) were 0.37 L/kg and 15.3 h, respectively. Furosemide CL was negatively associated with serum creatinine (SCr) [CL = 84.2 - 67.1 × SCr (mg/dL)]. CONCLUSIONS: Very preterm neonates within the first 2 weeks of life had a higher CL than subjects in other preterm neonatal studies. The SCr level was the sole parameter influencing furosemide CL and might serve as a good index for furosemide dosing in VP neonates.

Dissociation of the AhR/ARNT complex by TGF-ß/Smad signaling represses CYP1A1 gene expression and inhibits benze[a]pyrene-mediated cytotoxicity.

Cytochrome P450 1A1 (CYP1A1) catalyzes the metabolic activation of polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (B[a]P) and is transcriptionally regulated by the aryl hydrocarbon receptor (AhR)/AhR nuclear translocator (ARNT) complex upon exposure to PAHs. Accordingly, inhibition of CYP1A1 expression reduces production of carcinogens from PAHs. Although transcription of the CYP1A1 gene is known to be repressed by transforming growth factor-ß (TGF-ß), how TGF-ß signaling is involved in the suppression of CYP1A1 gene expression has yet to be clarified. In this study, using mammalian cell lines, along with shRNA-mediated gene silencing, CRISPR/Cas9-based genome editing, and reporter gene and quantitative RT-PCR assays, we found that TGF-ß signaling dissociates the B[a]P-mediated AhR/ARNT heteromeric complex. Among the examined Smads, Smad family member 3 (Smad3) strongly interacted with both AhR and ARNT via its MH2 domain. Moreover, hypoxia-inducible factor 1α (HIF-1α), which is stabilized upon TGF-ß stimulation, also inhibited AhR/ARNT complex formation in the presence of B[a]P. Thus, TGF-ß signaling negatively regulated the transcription of the CYP1A1 gene in at least two different ways. Of note, TGF-ß abrogated DNA damage in B[a]P-exposed cells. We therefore conclude that TGF-ß may protect cells against carcinogenesis because it inhibits CYP1A1-mediated metabolic activation of PAHs as part of its anti-tumorigenic activities.

PDZK1-interacting protein 1 (PDZK1IP1) traps Smad4 protein and suppresses transforming growth factor-ß (TGF-ß) signaling.

Transforming growth factor (TGF)-ß signaling in humans is stringently regulated to prevent excessive TGF-ß signaling. In tumors, TGF-ß signaling can both negatively and positively regulate tumorigenesis dependent on tumor type, but the reason for these opposite effects is unclear. TGF-ß signaling is mainly mediated via the Smad-dependent pathway, and herein we found that PDZK1-interacting protein 1 (PDZK1IP1) interacts with Smad4. PDZK1IP1 inhibited both the TGF-ß and the bone morphogenetic protein (BMP) pathways without affecting receptor-regulated Smad (R-Smad) phosphorylation. Rather than targeting R-Smad phosphorylation, PDZK1IP1 could interfere with TGF-ß- and BMP-induced R-Smad/Smad4 complex formation. Of note, PDZK1IP1 retained Smad4 in the cytoplasm of TGF-ß-stimulated cells. To pinpoint PDZK1IP1's functional domain, we created several PDZK1IP1 variants and found that its middle region, from Phe40 to Ala49, plays a key role in its Smad4-regulating activity. PDZK1IP1 knockdown enhanced the expression of the TGF-ß target genes Smad7 and prostate transmembrane protein androgen-induced (TMEPAI) upon TGF-ß stimulation. In contrast, PDZK1IP1 overexpression suppressed TGF-ß-induced reporter activities, cell migration, and cell growth inhibition. In a xenograft tumor model in which TGF-ß was previously shown to elicit tumor-promoting effects, PDZK1IP1 gain of function decreased tumor size and increased survival rates. Taken together, these findings indicate that PDZK1IP1 interacts with Smad4 and thereby suppresses the TGF-ß signaling pathway.

Developmental changes in urinary coproporphyrin ratio in premature infants.

BACKGROUND: Premature infants have a high concentration of conjugated bilirubin in their blood, although they have a poor glucuronide conjugation of bilirubin. This may be due to developmental changes in the function of adenosine triphosphate binding cassette subfamily C member 2, which is involved in the cellular export of conjugated bilirubin. In the present study, we examined the developmental changes in the urinary coproporphyrin I/(urinary coproporphyrin I+ urinary coproporphyrin III) ratio (UCP (I/ [I + III])), a known biomarker for adenosine triphosphate binding cassette subfamily C member 2 function, in premature infants. METHOD: Twenty-one premature infants born between 25 and 32 weeks of gestation were included in the study. Urine samples were collected within 24 h of birth, and at 1 week and 3-4 weeks after birth. The samples were analyzed by high-performance liquid chromatography to calculate UCP (I/ [I + III]) to examine its association with postnatal age and corrected gestational age. Subjects were excluded if they had liver dysfunction, cholestasis, urinary tract infection, or chromosomal abnormalities. RESULTS: The average UCP (I/ [I + III]) within 24 h of birth, at 1 week, and at 3-4 weeks after birth was 0.84, 0.61, and 0.65, respectively. The UCP (I/ [I + III]) within 24 h of birth was significantly higher than that measured at 1 week or 3-4 weeks after birth. There was no significant correlation between UCP (I/ [I + III]) and the corrected gestational age. CONCLUSION: The UCP (I/ [I + III]) was higher within 24 h of birth. It decreased 1 week after birth and remained low without any significant changes for up to 4 weeks after birth.

Hour-specific nomogram for transcutaneous Bilirubin in newborns in Myanmar.

BACKGROUND: Neonatal hyperbilirubinemia is a significant health problem in Myanmar, and the rate of kernicterus is also higher than in developed countries. Non-invasive methods for early detection and treatment of hyperbilirubinemia are urgently needed. In this study, we used transcutaneous bilirubin (TcB) measurements to develop an hour-specific TcB nomogram for the effective management of hyperbilirubinemia in Myanmar newborns. METHODS: The bilirubin levels of neonates born in Central Women Hospital in Yangon, Myanmar were measured three times a day within 72 h after birth using a transcutaneous bilirubinometer. An hour-specific TcB nomogram was created based on the data. RESULTS: Participants were 512 infants (287 boys, 225 girls) born in Central Women's Hospital in Yangon. The mean (±SD) gestational age was 38.4 ± 1.2 weeks; birthweight was 3078 ± 412 g. A total of 3,039 plots were obtained, and the TcB nomogram was created with smoothed percentile curves (97.5th, 50th, and 2.5th percentiles) for 0-72 h after birth. CONCLUSIONS: An hour-specific TcB nomogram was successfully created to manage hyperbilirubinemia in Myanmar newborns.

Green light-emitting diode phototherapy for neonatal hyperbilirubinemia: Randomized controlled trial.

BACKGROUND: The main photochemical pathway in phototherapy for neonatal hyperbilirubinemia is the production and elimination (in bile or urine) of cyclobilirubin, which is a structural photoisomer of bilirubin, and which is most efficiently produced by green light. Green light-emitting diode (LED) phototherapy, however, has not been evaluated in the clinical setting because it is not recommended in American Academy of Pediatrics guidelines. We therefore compared the efficacy of green LED phototherapy and blue LED phototherapy in patients with neonatal hyperbilirubinemia. METHODS: In this prospective randomized controlled trial, neonates with hyperbilirubinemia were randomly allocated to a green LED or blue LED phototherapy group. Both groups underwent 24 h of phototherapy, and blood was sampled before and after 24 h of phototherapy. Total serum bilirubin (TSB) was measured using enzymatic methods and bilirubin photoisomers were measured on high-performance liquid chromatography. RESULTS: Thirty-four infants were randomized (green, n = 16; blue, n = 18). TSB decreased significantly from 15.3 ± 1.5 to 13.9 ± 1.5 mg/dL in the green LED group (P < 0.01) and from 16.2 ± 1.3 to 14.5 ± 1.7 mg/dL in the blue LED group (P < 0.01) after 24 h of phototherapy. No significant difference was found in TSB reduction after phototherapy between the groups. CONCLUSIONS: Both light sources produced a significant reduction in TSB, indicating clinical effectiveness.

TMED10 Protein Interferes with Transforming Growth Factor (TGF)-ß Signaling by Disrupting TGF-ß Receptor Complex Formation.

The intensity and duration of TGF-ß signaling determine the cellular biological response. How this is negatively regulated is not well understood. Here, we identified a novel negative regulator of TGF-ß signaling, transmembrane p24-trafficking protein 10 (TMED10). TMED10 disrupts the complex formation between TGF-ß type I (also termed ALK5) and type II receptors (TßRII). Misexpression studies revealed that TMED10 attenuated TGF-ß-mediated signaling. A 20-amino acid-long region from Thr91 to Glu110 within the extracellular region of TMED10 was found to be crucial for TMED10 interaction with both ALK5 and TßRII. Synthetic peptides corresponding to this region inhibit both TGF-ß-induced Smad2 phosphorylation and Smad-dependent transcriptional reporter activity. In a xenograft cancer model, where previously TGF-ß was shown to elicit tumor-promoting effects, gain-of-function and loss-of-function studies for TMED10 revealed a decrease and increase in the tumor size, respectively. Thus, we determined herein that TMED10 expression levels are the key determinant for efficiency of TGF-ß receptor complex formation and signaling.

TMEPAI, a transmembrane TGF-beta-inducible protein, sequesters Smad proteins from active participation in TGF-beta signaling.

Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine of key importance for controlling embryogenesis and tissue homeostasis. How TGF-beta signals are attenuated and terminated is not well understood. Here, we show that TMEPAI, a direct target gene of TGF-beta signaling, antagonizes TGF-beta signaling by interfering with TGF-beta type I receptor (TbetaRI)-induced R-Smad phosphorylation. TMEPAI can directly interact with R-Smads via a Smad interaction motif. TMEPAI competes with Smad anchor for receptor activation for R-Smad binding, thereby sequestering R-Smads from TbetaRI kinase activation. In mammalian cells, ectopic expression of TMEPAI inhibited TGF-beta-dependent regulation of plasminogen activator inhibitor-1, JunB, cyclin-dependent kinase inhibitors, and c-myc expression, whereas specific knockdown of TMEPAI expression prolonged duration of TGF-beta-induced Smad2 and Smad3 phosphorylation and concomitantly potentiated cellular responsiveness to TGF-beta. Consistently, TMEPAI inhibits activin-mediated mesoderm formation in Xenopus embryos. Therefore, TMEPAI participates in a negative feedback loop to control the duration and intensity of TGF-beta/Smad signaling.

Targeted Degradation of Proteins Localized in Subcellular Compartments by Hybrid Small Molecules.

Development of novel small molecules that selectively degrade pathogenic proteins would provide an important advance in targeted therapy. Recently, we have devised a series of hybrid small molecules named SNIPER (specific and nongenetic IAP-dependent protein ERaser) that induces the degradation of target proteins via the ubiquitin-proteasome system. To understand the localization of proteins that can be targeted by this protein knockdown technology, we examined whether SNIPER molecules are able to induce degradation of cellular retinoic acid binding protein II (CRABP-II) proteins localized in subcellular compartments of cells. CRABP-II is genetically fused with subcellular localization signals, and they are expressed in the cells. SNIPER(CRABP) with different IAP-ligands, SNIPER(CRABP)-4 with bestatin and SNIPER(CRABP)-11 with MV1 compound, induce the proteasomal degradation of wild-type (WT), cytosolic, nuclear, and membrane-localized CRABP-II proteins, whereas only SNIPER(CRABP)-11 displayed degradation activity toward the mitochondrial CRABP-II protein. The small interfering RNA-mediated silencing of cIAP1 expression attenuated the knockdown activity of SNIPER(CRABP) against WT and cytosolic CRABP-II proteins, indicating that cIAP1 is the E3 ligase responsible for degradation of these proteins. Against membrane-localized CRABP-II protein, cIAP1 is also a primary E3 ligase in the cells, but another E3 ligase distinct from cIAP2 and X-linked inhibitor of apoptosis protein (XIAP) could also be involved in the SNIPER(CRABP)-11-induced degradation. However, for the degradation of nuclear and mitochondrial CRABP-II proteins, E3 ligases other than cIAP1, cIAP2, and XIAP play a role in the SNIPER-mediated protein knockdown. These results indicate that SNIPER can target cytosolic, nuclear, membrane-localized, and mitochondrial proteins for degradation, but the responsible E3 ligase is different, depending on the localization of the target protein.

Phototherapy for neonatal hyperbilirubinemia.

Approximately 60 years ago in England, phototherapy for neonatal hyperbilirubinemia was used in clinical practice. It was introduced in Japan approximately 50 years ago. At that time, the mechanism underlying the serum bilirubin concentration decrease by phototherapy was still unknown. The mechanism was identified by chemists, biochemists, and pediatricians. Clarification started with the report that unconjugated bilirubin was excreted into bile after photoirradiation in Gunn rats. After confirmation of the molecular structure of bilirubin on X-ray analysis, the mechanism for bile excretion of unconjugated bilirubin was verified based on geometric configurational photoisomers in the Gunn rat. Finally, the reaction and excretion of structural bilirubin photoisomers was proved to be the main mechanism for the decrease in serum bilirubin during phototherapy for neonatal hyperbilirubinemia, which differs from the mechanism in the Gunn rat. The most effective and safest light source and the optimal method to evaluate phototherapy, however, remain unknown. Moreover, as for bronze baby syndrome, which is a well-known adverse reaction to phototherapy, the etiology is unclear. Hence, we review phototherapy for hyperbilirubinemia including a fundamental understanding of the bilirubin photochemical reactions, and discuss the subclinical carcinogenic risk of phototherapy and the increased mortality rate of extremely low-birthweight infants due to aggressive phototherapy, which is becoming an increasing problem.

Developmental characteristics of urinary coproporphyrin I/(I + III) ratio.

BACKGROUND: The ratio of urinary coproporphyrin (UCP) I to total urinary coproporphyrin I and III [UCP {I/(I + III)]] serves as a biomarker of the ATP-binding cassette, sub-family C, member 2 (ABCC2) function. The aim of this study was to clarify the characteristics of the developmental pattern of UCP [I/(I + III)] in order to estimate ABCC2 function in children, especially in the neonatal period, by measuring it throughout the entirety of childhood. METHOD: Measurement of UCP [I/(I + III)] was done high-performance liquid chromatography, using urine samples collected from children from 1 day to 15 years old, involving one sample per child. Urine samples from children with liver and kidney disease and urinary tract infection were excluded. RESULTS: UCP [I/(I + III)] varied widely in infants younger than 6 months old, and was ≥0.3 in 80% of the infants. In contrast, it decreased to <0.30, the lowest, at 1-2 years old. In the 0-6-month-old group, no significant correlation was noted between postnatal age and UCP [I/(I + III)], but a moderate inverse correlation was noted between corrected gestational age and UCP [I/(I + III)]. CONCLUSION: UCP [I/(I + III)] is inversely correlated with corrected gestational age and is lowest at 1-2 years old. This suggests that ABCC2 activity is correlated with corrected gestational age and is highest at 1-2 years old.

Evans syndrome after autologous peripheral blood stem cell transplantation for recurrent Hodgkin lymphoma.

There have been a number of recent reports on the occurrence of autoimmune conditions after autologous hematopoietic stem cell transplantation. We describe a rare case of Evans syndrome (ES) that developed in a 16-year-old patient >1 year after autologous peripheral blood stem cell transplantation for recurrent Hodgkin lymphoma. ES is a rare and frequently refractory condition. No therapy for the condition has been established, and it can often be fatal. In the present case, i.v. cyclosporine A injection was significantly effective against the ES, which has not recurred.

C18 ORF1, a novel negative regulator of transforming growth factor-ß signaling.

Transforming growth factor (TGF)-ß signaling is deliberately regulated at multiple steps in its pathway from the extracellular microenvironment to the nucleus. However, how TGF-ß signaling is activated or attenuated is not fully understood. We recently identified transmembrane prostate androgen-induced RNA (TMEPAI), which is involved in a negative feedback loop of TGF-ß signaling. When we searched for a family molecule(s) for TMEPAI, we found C18ORF1, which, like TMEPAI, possesses two PY motifs and one Smad-interacting motif (SIM) domain. As expected, C18ORF1 could block TGF-ß signaling but not bone morphogenetic protein signaling. C18ORF1 bound to Smad2/3 via its SIM and competed with the Smad anchor for receptor activation for Smad2/3 binding to attenuate recruitment of Smad2/3 to the TGF-ß type I receptor (also termed activin receptor-like kinase 5 (ALK5)), in a similar fashion to TMEPAI. Knockdown of C18ORF1 prolonged duration of TGF-ß-induced Smad2 phosphorylation and concomitantly potentiated the expression of JunB, p21, and TMEPAI mRNAs induced by TGF-ß. Consistently, TGF-ß-induced cell migration was enhanced by the knockdown of C18ORF1. These results indicate that the inhibitory function of C18ORF1 on TGF-ß signaling is similar to that of TMEPAI. However, in contrast to TMEPAI, C18ORF1 was not induced upon TGF-ß signaling. Thus, we defined C18ORF1 as a surveillant of steady state TGF-ß signaling, whereas TMEPAI might help C18ORF1 to inhibit TGF-ß signaling in a coordinated manner when cells are stimulated with high levels of TGF-ß.

Transforming growth factor-ß signaling enhancement by long-term exposure to hypoxia in a tumor microenvironment composed of Lewis lung carcinoma cells.

Transforming growth factor-ß (TGF-ß) is a potent growth inhibitor in normal epithelial cells. However, a number of malignant tumors produce excessive amounts of TGF-ß, which affects the tumor-associated microenvironment by furthering the progression of tumorigenicity. Although it is known that the tumor-associated microenvironment often becomes hypoxic, how hypoxia influences TGF-ß signaling in this microenvironment is unknown. We investigated whether TGF-ß signaling is influenced by long-term exposure to hypoxia in Lewis lung carcinoma (LLC) cells. When the cells were exposed to hypoxia for more than 10 days, their morphology was remarkably changed to a spindle shape, and TGF-ß-induced Smad2 phosphorylation was enhanced. Concomitantly, TGF-ß-induced transcriptional activity was augmented under hypoxia, although TGF-ß did not influence the activity of a hypoxia-responsive reporter. Consistently, hypoxia influenced the expression of several TGF-ß target genes. Interestingly, the expressions of TGF-ß type I receptor (TßRI), also termed activin receptor like kinase-5 (ALK5), and TGF-ß1 were increased under the hypoxic condition. When we monitored the hypoxia-inducible factor-1 (HIF-1) transcriptional activity by use of green fluorescent protein governed by the hypoxia-responsive element in LLC cells transplanted into mice, TGF-ß-induced Smad2 phosphorylation was upregulated in vivo. Our results demonstrate that long-term exposure to hypoxia might alter responsiveness to TGF-ß signaling and affected the malignancy of LLC cells.

Current incidence of clinical kernicterus in preterm infants in Japan.

Clinical kernicterus in preterm infants has recently been reported in Japan, diagnosed on the basis of clinical findings during the neonatal and infancy periods. We investigated the incidence of clinical kernicterus in preterm infants <30 weeks gestational age (GA) based on a nationwide survey conducted in 233 certified educational facilities for neonatologists. The numbers of infants admitted and infants who died within 14 days after birth during 2011, and the number of infants who subsequently developed clinical kernicterus, were recorded. A total of 2720 infants were analyzed, representing 59% (2720/4623) of all preterm live births <30 weeks GA in Japan in 2011. Of these, 159 (5.8%) died within 14 days after birth, similar to the national rate. Five infants developed clinical kernicterus in infancy (5/2720, 0.18%). The current incidence of clinical kernicterus in Japan is therefore estimated at 1.8 per 1000 live births <30 weeks GA.

TMEPAI/PMEPA1 enhances tumorigenic activities in lung cancer cells.

TMEPAI/PMEPA1 is a transmembrane protein that was originally identified as a prostatic RNA, the synthesis of which is induced by testosterone or its derivatives. We have recently identified TMEPAI as a direct target gene of transforming growth factor-ß (TGF-ß)/Smad signaling that participates in negative feedback control of the duration and intensity of TGF-ß/Smad signaling. TMEPAI is constitutively and highly expressed in many types of cancer and is associated with poor prognosis. Here, we report that TMEPAI is highly expressed in the lung adenocarcinoma cell lines Calu3, NCI-H23, and RERF-LC-KJ. Expression of TMEPAI in these cancer cells was significantly suppressed by a TGF-ß receptor kinase antagonist, SB208, and by TGF-ß neutralizing antibodies. These results suggest that constitutive expression of TMEPAI in these cancer cells depends on autocrine TGF-ß stimulation. Knockdown of TMEPAI in Calu3 and NCI-H23 cells enhanced levels of Smad2 phosphorylation and significantly suppressed cell proliferation in the presence of TGF-ß, indicating that highly expressed TMEPAI suppresses levels of Smad phosphorylation in these cancer cells and reduces the growth inhibitory effects of TGF-ß/Smad signaling. Furthermore, knockdown of TMEPAI in Calu3 and NCI-H23 cells suppressed sphere formation in vitro and tumor formation in s.c. tissues and in lungs after tail vein injection in NOD-SCID mice in vivo. Together, these experiments indicate that TMEPAI promotes tumorigenic activities in lung cancer cells.

Smad2/Smad3 in endothelium is indispensable for vascular stability via S1PR1 and N-cadherin expressions.

Transforming growth factor-ß (TGF-ß) is involved in vascular formation through activin receptor-like kinase (ALK)1 and ALK5. ALK5, which is expressed ubiquitously, phosphorylates Smad2 and Smad3, whereas endothelial cell (EC)-specific ALK1 activates Smad1 and Smad5. Because ALK5 kinase activity is required for ALK1 to transduce TGF-ß signaling via Smad1/5 in ECs, ALK5 knockout (KO) mice were not able to give us the precise mechanisms by which TGF-ß/ALK5/Smad2/3 signaling is implicated in angiogenesis. To delineate the role of Smad2/3 signaling in endothelium, the Smad2 gene in Smad3 KO mice was selectively deleted in ECs using Tie2-Cre transgenic mice, termed EC-specific Smad2/3 double KO (EC-Smad2/3KO) mice. EC-Smad2/3KO embryos revealed hemorrhage leading to embryonic lethality around E12.5. EC-Smad2/3KO embryos exhibited no abnormality of vasculogenesis and angiogenesis in both the yolk sac and the whole embryo, whereas vascular maturation was incomplete because of inadequate assembly of mural cells in the vasculature. Wide gaps between ECs and mural cells could be observed in the vasculature of EC-Smad2/3KO mice because of reduced expression of N-cadherin and sphingosine-1-phosphate receptor-1 (S1PR1) in ECs from those mice. These results indicated that Smad2/3 signaling in ECs is indispensable for maintenance of vascular integrity via the fine-tuning of N-cadherin, VE-cadherin, and S1PR1 expressions in the vasculature.

Negative regulation of TGF-beta receptor/Smad signal transduction.

Members of the transforming growth factor-beta (TGF-beta) family are highly conserved multifunctional cell-cell signaling proteins that are of key importance for controlling embryogenesis and tissue homeostasis. At first glance, signaling through TGF-beta family members appears to be a simple process: ligands bind to specific serine/threonine kinase transmembrane receptors, which activate intracellular Smad effector proteins, which in turn relay the signal to the nucleus to control gene transcription. However, recent research has revealed that additional layers of complexity exist at each step in the TGF-beta/Smad pathway. The expression, activation and inactivation, subcellular localization, and stability of TGF-beta signaling components are tightly regulated and subject to input from other signaling pathways. A broad array of Smad interacting partners and diverse post-translational modifications of Smads have been identified. Recently, important advances have been made in our understanding of how TGF-beta family signals are attenuated and terminated to maintain control over this versatile pathway.

Neonatal Dubin-Johnson syndrome: novel compound heterozygous mutation in the ABCC2 gene.

Dubin-Johnson syndrome (DJS) is an autosomal recessive inherited disorder characterized by conjugated hyperbilirubinemia. Neonatal-onset DJS is rare. It is caused by dysfunction of adenosine triphosphate-binding cassette, sub-family C, member 2 (ABCC2). We found a novel compound heterozygous mutation of DJS-related gene: W709R (T2145C): a missense mutation in exon 17, and R768W (C2302T), a missense mutation in exon 18. Serum diglucuronosyl bilirubin/monoglucuronosyl bilirubin ratio was high. ABCC2 may excrete diglucuronosyl bilirubin preferentially over monoglucuronosyl bilirubin.

Design and synthesis of chiral Zn2+ complexes mimicking natural aldolases for catalytic C-C bond forming reactions in aqueous solution.

Extending carbon frameworks via a series of C-C bond forming reactions is essential for the synthesis of natural products, pharmaceutically active compounds, active agrochemical ingredients, and a variety of functional materials. The application of stereoselective C-C bond forming reactions to the one-pot synthesis of biorelevant compounds is now emerging as a challenging and powerful strategy for improving the efficiency of a chemical reaction, in which some of the reactants are subjected to successive chemical reactions in just one reactor. However, organic reactions are generally conducted in organic solvents, as many organic molecules, reagents, and intermediates are not stable or soluble in water. In contrast, enzymatic reactions in living systems proceed in aqueous solvents, as most of enzymes generally function only within a narrow range of temperature and pH and are not so stable in less polar organic environments, which makes it difficult to conduct chemoenzymatic reactions in organic solvents. In this review, we describe the design and synthesis of chiral metal complexes with Zn2+ ions as a catalytic factor that mimic aldolases in stereoselective C-C bond forming reactions, especially for enantioselective aldol reactions. Their application to chemoenzymatic reactions in aqueous solution is also presented.