The efficiency of translation termination is determined by a synergistic interplay between upstream and downstream sequences in Saccharomyces cerevisiae

In a recent study we found that the efficiency of translation termination could be decreased several hundred fold by altering the local sequence context surrounding stop codons in the yeast Saccharomyces cerevisiae. Suppression of termination was shown to be mediated by near-cognate tRNA mispairing with the termination codon. We have now examined in greater detail how the local sequence context affects the efficiency of translation termination in this organism. Our results indicate that the sequence immediately upstream of the termination codon plays a significant role in determining the efficiency of translation termination. An extended termination sequence (containing the stop codon and the following three nucleotides) was also found to be a major determinant of termination efficiency, with effects attributable to the fourth nucleotide being largely independent of the termination codon. For the UGA and UAA stop codons, the influence of the fourth position on termination efficiency (from most efficient to least efficient termination) was found to be G > U,A > C, while for the UAG codon it was U,A > C > G. These sequence-specific effects on the efficiency of translation termination suggest that polypeptide chain release factor (or another molecule that may play a role in translation termination, such as rRNA) recognizes an extended termination sequence in yeast. A previous study found a statistically significant bias toward certain tetranucleotide sequences (containing the stop codon and the first distal nucleotide) in several organisms. We found that tetranucleotide sequences most frequently used in yeast are among the most efficient at mediating translation termination, while rare tetranucleotide sequences mediate much less efficient termination. Taken together, our results indicate that upstream and downstream components of an extended sequence context act synergistically to determine the overall efficiency of translation termination in yeast.

Clinical significance of respiratory bronchiolitis on open lung biopsy and its relationship to smoking related interstitial lung disease

BACKGROUND

Respiratory bronchiolitis-associated interstitial lung disease (RBILD) is a rare form of interstitial lung disease which may present in similar fashion to other types of chronic interstitial pneumonia. The purpose of this study was to undertake a clinicopathological review of 10 patients with RBILD and to examine the clinical and imaging data related to its histopathological pattern, in particular the relationship of RBILD to smoking.

METHODS

Thirteen out of 168 retrospectively reviewed patients, from whom biopsy specimens were taken for suspected diffuse lung disease, were identified with a histopathological pattern of RBILD. Three cases were rejected as follow up data were unavailable. The 10 remaining cases constituted the study group and both clinical and imaging data were collected from patients' notes and referring physicians.

RESULTS

Histopathologically, four cases of RBILD overlapped with the pattern of desquamative interstitial pneumonitis (DIP) and nine also had microscopic evidence of centrilobular emphysema. Nine patients were smokers, ranging from 3 to 80 pack years. The one non-smoker had an occupational exposure to the fumes of solder flux. The sex distribution was equal with an age range of 32-65 years. Two patients were clubbed. Lung function tests showed both restrictive and obstructive patterns together with severe reductions in carbon monoxide transfer factor in seven patients. Chest radiographs showed reticular or reticulonodular infiltrates in five patients and a ground glass pattern in two. CT scans were consistent with either DIP or RBILD in six of eight patients. Although seven patients remained stable or improved, either with or without treatment, three patients deteriorated.

CONCLUSIONS

This study adds weight to the hypothesis that smoking can cause clinically significant interstitial lung disease, with deterioration in pulmonary function despite treatment. Given the overlapping histopathological patterns of RBILD and DIP and their strong association with smoking, the term "smoking related interstitial lung disease" is suggested for those patients who are smokers.

Crystal structure and functional analysis of the SurE protein identify a novel phosphatase family

Homologs of the Escherichia coli surE gene are present in many eubacteria and archaea. Despite the evolutionary conservation, little information is available on the structure and function of their gene products. We have determined the crystal structure of the SurE protein from Thermotoga maritima. The structure reveals the dimeric arrangement of the subunits and an active site around a bound metal ion. We also demonstrate that the SurE protein exhibits a divalent metal ion-dependent phosphatase activity that is inhibited by vanadate or tungstate. In the vanadate- and tungstate-complexed structures, the inhibitors bind adjacent to the divalent metal ion. Our structural and functional analyses identify the SurE proteins as a novel family of metal ion-dependent phosphatases.

Crystal structure of NAD(+)-dependent DNA ligase: modular architecture and functional implications

DNA ligases catalyze the crucial step of joining the breaks in duplex DNA during DNA replication, repair and recombination, utilizing either ATP or NAD(+) as a cofactor. Despite the difference in cofactor specificity and limited overall sequence similarity, the two classes of DNA ligase share basically the same catalytic mechanism. In this study, the crystal structure of an NAD(+)-dependent DNA ligase from Thermus filiformis, a 667 residue multidomain protein, has been determined by the multiwavelength anomalous diffraction (MAD) method. It reveals highly modular architecture and a unique circular arrangement of its four distinct domains. It also provides clues for protein flexibility and DNA-binding sites. A model for the multidomain ligase action involving large conformational changes is proposed.

Structural basis of non-specific lipid binding in maize lipid-transfer protein complexes revealed by high-resolution X-ray crystallography

Non-specific lipid-transfer proteins (nsLTPs) are involved in the movement of phospholipids, glycolipids, fatty acids, and steroids between membranes. Several structures of plant nsLTPs have been determined both by X-ray crystallography and nuclear magnetic resonance. However, the detailed structural basis of the non-specific binding of hydrophobic ligands by nsLTPs is still poorly understood. In order to gain a better understanding of the structural basis of the non-specific binding of hydrophobic ligands by nsLTPs and to investigate the plasticity of the fatty acid binding cavity in nsLTPs, seven high-resolution (between 1.3 A and 1.9 A) crystal structures have been determined. These depict the nsLTP from maize seedlings in complex with an array of fatty acids.A detailed comparison of the structures of maize nsLTP in complex with various ligands reveals a new binding mode in an nsLTP-oleate complex which has not been seen before. Furthermore, in the caprate complex, the ligand binds to the protein cavity in two orientations with equal occupancy. The volume of the hydrophobic cavity in the nsLTP from maize shows some variation depending on the size of the bound ligands. The structural plasticity of the ligand binding cavity and the predominant involvement of non-specific van der Waals interactions with the hydrophobic tail of the ligands provide a structural explanation for the non-specificity of maize nsLTP. The hydrophobic cavity accommodates various ligands from C10 to C18. The C18:1 ricinoleate with its hydroxyl group hydrogen bonding to Ala68 possibly mimics cutin monomer binding which is of biological importance. Some of the myristate binding sites in human serum albumin resemble the maize nsLTP, implying the importance of a helical bundle in accommodating the non-specific binding of fatty acids.

Antiobesity effects of quercetin-rich onion peel extract on the differentiation of 3T3-L1 preadipocytes and the adipogenesis in high fat-fed rats

The aim of the present study was to examine the effect of quercetin-rich onion peel extract (OPE) on anti-differentiation in 3T3-L1 preadipocytes and the antiobesity in high-fat fed rats. We found that lipid accumulations and TG contents in 3T3-L1 cells were markedly suppressed by OPE. The mRNA levels of activating protein (AP2) were down-regulated and those of carnitine palmitoyl transferase-1 α (CPT-1α) and fatty acid binding protein 4 (FABP4) were up-regulated by 75 and 100 μg/ml OPE. Body weight, retroperitoneal and mesenteric fat weights of SD rats were significantly lower in the 8 week high fat (HF) diet+0.72% OPE group than in the HF group. Peroxisome proliferator-activated receptor (PPAR)γ mRNA levels were down-regulated in the epididymal fat of OPE than those of control and HF, and significant down-regulation of CCAAT/enhancer binding protein (C/EBP)α mRNA levels in OPE was also observed than the control. The mRNA levels of CPT-1α and uncoupling protein-1 (UCP-1) were up-regulated by the OPE, while those of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) were down-regulated in HF and OPE groups compared to control group. These results suggest that quercentin-enriched OPE may have antiobesity effects by suppressing preadipocyte differentiation and inhibiting adipogenesis.

Vanadium as a modulator of cellular regulatory cascades and oncogene expression

Vanadium, a trace metal in the environment and in biological systems, influences the behavior of enzymes, mimics and regulates growth factor activity, is a potential mutagenic and carcinogenic agent, and regulates gene expression. The diverse biological actions of vanadium result from its capacity to function as an oxyanion, oxycation, or prooxidant. Vanadium is found in water, rocks, and soils in low concentration and in relatively high concentrations in coal and oil deposits. Vanadium compounds at much higher concentrations than are typically ingested are being considered in the treatment of diabetes mellitus. The actions of insulin and vanadium on the insulin receptor are similar, but the mechanisms are not identical. Vanadium modulates growth-factor-mediated signal transduction pathways. Vanadium promotes cell transformation and diminishes cell adhesion. Consistent with its mitogenic action and its capacity to mimic mitogenic growth factors, vanadium stimulates expression of protooncogenes. In particular, oxygen-derived active species are involved in the expression of the jun protooncogene in the presence of vanadium. The unique cellular activity of vanadium makes it a tool of unparalleled potential for studying mechanisms of cell growth, differentiation, and metabolism.

Ten-year experience in porto-caval hemitransposition for liver transplantation in the presence of portal vein thrombosis

Porto-caval hemitransposition (PCH) in liver transplantation allows revascularization of the liver when the porto-mesenteric axis is thrombosed. We, here, review our experience over an 11-year period. A total of 23 patients underwent liver transplantation using PCH. Immunosuppression was based on tacrolimus, with sirolimus used in case of renal insufficiency. Most common diagnoses were hepatitis C, Laennec's, Budd-Chiari and cryptogenic cirrhosis. Six patients needed splenectomy prior to transplant, 5 during transplant, 1 post-transplant, 11 had no splenectomy. Overall survival was 60% at 1 year and 38% at 3 years, with 10 of 23 patients currently alive and the longest survivor at 9.3 years. Most common cause of death was sepsis/multisystem organ failure, followed by pulmonary embolism. A total of 7/23 patients experienced post-operative gastrointestinal bleeding episodes, 6/23 patients developed thrombosis of the vena cava (median 162 days post-op). Post-operative ascites was noted in almost all patients. Renal dysfunction was commonly seen even after the first month post-transplant. PCH offers a feasible option for liver transplantation in those patients with complex thrombosis of the mesenteric and portal circulation.

Is respiratory sinus arrhythmia a good index of cardiac vagal tone in exercise?

To assess the relative roles of neural and nonneural mechanisms in respiratory sinus arrhythmia (RSA) at rest and during exercise (steady-state supine cycle ergometry at 25% of peak oxygen uptake), we studied 10 healthy men (mean age 21 +/- 1 yr) before (control) and during ganglion blockade (GB) with trimetaphan camsylate (3-5 mg/min i.v.). GB was confirmed by the abolition of the reflex bradycardia in response to intravenous phenylephrine and of the blood pressure rise with the cold pressor test. RSA was calculated from the power of the spectral component of the R-R interval variability centered at the breathing frequency. GB decreased but did not abolish RSA. At rest, this nonneural component of RSA was negligible, accounting for < 1% of the control RSA. During GB, exercise did not affect RSA significantly. However, because control RSA was decreased by exercise, the proportion of nonneural RSA increased by 32% (range from 17 to 75%). These results indicate that as the vagal tone decreases with exercise, an increasing proportion of RSA is due to nonneural mechanisms.

Differences in the fetal interleukin-6 response to microbial invasion of the amniotic cavity between term and preterm gestation

BACKGROUND/OBJECTIVE

Fetal inflammatory response has been implicated as a mechanism of multi-system organ injury in preterm and term neonates. Microbial invasion of the amniotic cavity (MIAC) is frequently associated with a fetal inflammatory response. However, there are no studies comparing the fetal response to MIAC in term and preterm gestations. The purpose of this study was to compare the umbilical cord plasma interleukin-6 (IL-6) concentrations in term and preterm neonates in the presence or absence of MIAC.

STUDY DESIGN

Umbilical cord blood was obtained at birth from 252 neonates whose mothers had an amniocentesis within 48 h of delivery (preterm delivery, n = 62; term delivery, n = 190). MIAC was defined as a positive amniotic fluid culture for bacteria or genital mycoplasmas. IL-6 was measured by a sensitive and specific immunoassay.

RESULTS

The median IL-6 concentration in umbilical cord plasma was significantly higher in preterm neonates than in term neonates (median 13.4 pg/ml, range 0.1-676 pg/ml vs. median 3.2 pg/ml, range 0.1-408 pg/ml; p < 0.0001). In the context of MIAC, the median umbilical cord plasma IL-6 concentration was significantly higher in preterm than in term neonates (median 31.6 pg/ml, range 1.4-676 pg/ml vs. median 11.7 pg/ml, range 1.3-82 pg/ml, respectively; p < 0.05). Neonates born to mothers with a positive amniotic fluid culture had a significantly higher median IL-6 concentration than neonates born to mothers with a negative amniotic fluid culture (preterm: median 31.6, range 1.4-676 pg/ml vs. median 8.0, range 0.1-656 pg/ml; p < 0.05 and term: median 11.7, range 1.3-82 pg/ml vs. median 3.1, range 0.1-408 pg/ml; p < 0.01, respectively).

CONCLUSIONS

The preterm fetus is capable of mounting a systemic cytokine response as measured by IL-6 in its peripheral blood. In the setting of MIAC, a fetal IL-6 response is higher in preterm than in term gestation.

Attentional dysfunction, impulsivity, and resistance to change in a mouse model of fragile X syndrome

On a series of attention tasks, male mice with a mutation targeted to the fragile X mental retardation 1 (Fmrl) gene (Fmrl knockout [KO] mice) committed a higher rate of premature responses than wild-type littermates, with the largest differences seen when task contingencies changed. This finding indicates impaired inhibitory control, particularly during times of stress or arousal. The KO mice also committed a higher rate of inaccurate responses than controls, particularly during the final third of each daily test session, indicating impaired sustained attention. In the selective attention task, the unpredictable presentation of potent olfactory distractors produced a generalized disruption in the performance of the KO mice, whereas for controls, the disruption produced by the distractors was temporally limited. Finally, the attentional disruption seen following an error was more pronounced for the KO mice than for controls, further implicating impaired regulation of arousal and/or negative affect. The present study provides the first evidence that the Fmrl KO mouse is impaired in inhibitory control, attention, and arousal regulation, hallmark areas of dysfunction in fragile X syndrome. The resistance to change also seen in these mice provides a behavioral index for studying the autistic features of this disorder.

Room-Temperature Continuous-Wave Operation of Organometal Halide Perovskite Lasers

Solution-processed organic-inorganic lead halide perovskites have recently emerged as promising gain media for tunable semiconductor lasers. However, optically pumped continuous-wave lasing at room temperature, a prerequisite for a laser diode, has not been realized so far. Here, we report lasing action in a surface-emitting distributed feedback methylammonium lead iodide (MAPbI₃) perovskite laser on a silicon substrate at room temperature under continuous-wave optical pumping. This outstanding performance is achieved because of the ultralow lasing threshold of 13 W/cm², which is enabled by thermal nanoimprint lithography that directly patterns perovskite into a high- Q cavity with large mode confinement, while at the same time, it improves perovskite's emission characteristics. Our results represent a major step toward electrically pumped lasing in organic and thin-film materials as well as the insertion of perovskite lasers into photonic integrated circuits for applications in optical computing, sensing, and on-chip quantum information.

Phase II trial of imatinib mesylate in recurrent, biomarker positive, ovarian cancer (Southwest Oncology Group Protocol S0211)

Platinum-resistant ovarian cancer continues to be a difficult therapeutic problem. Clearly, molecularly targeted agents should be evaluated in this patient population. Patients were eligible for this phase II study with stage III or IV ovarian cancer, whose tumor expressed Kit (CD117) or platelet-derived growth factor receptor (PDGFR) and with relapse of measurable disease within 6 months of completing frontline, platinum- and taxane-based chemotherapy. Patients were treated daily with 400 mg of imatinib mesylate orally. It was assumed that the agent would be of no further interest if the population response rate was less than 10%. A two-stage design was used for patient accrual. A total of 34 patients were registered to the study. Of these, 15 were found to be ineligible or not evaluable (8 because their tumor samples were negative for both DC117 and PDGFR). Of 19 evaluable patients, 2 (11%) tested positively for c-Kit and 17 (89%) tested positively for PDGFR. There were no objective responders. Thirteen patients (68%) had increasing disease or symptomatic deterioration, and six (32%) went off protocol during the first month due to adverse events. Median progression-free survival was 2 months (95% CI 1-3 months) and median overall survival was 10 months (95% CI 6-18 months). Eleven percent of patients experienced grade 4 hematologic/metabolic toxicity and 37% experienced grade 3 nonhematologic toxicity. We conclude that imatinib mesylate as a single agent does not appear to have useful clinical activity in c-Kit and/or PDGFR positive, recurrent ovarian cancer in heavily pretreated patients with ovarian cancer.

Quercetin up-regulates expressions of peroxisome proliferator-activated receptor γ, liver X receptor α, and ATP binding cassette transporter A1 genes and increases cholesterol efflux in human macrophage cell line

Cholesterol-laden macrophages trigger accumulation of foam cells and increase the risk of developing atherosclerosis. We hypothesized that quercetin could lower the content of cholesterol in macrophages by regulating the expression of the ATP binding cassette transporter A1 (ABCA1) gene in differentiated human acute monocyte leukemia cell line (THP-1) cells and thereby reducing the chance of forming foam cells. Quercetin, in concentrations up to 30 μM, was not cytotoxic to differentiated THP-1 cells. Quercetin up-regulated both ABCA1 messenger RNA and protein expression in differentiated THP-1 cells, and its maximum effects were demonstrated at 0.3 μM for 4 to 8 hours in incubation. In addition, quercetin increased protein levels of peroxisome proliferator-activated receptor γ (PPARγ) and liver X receptor α (LXRα) within 2 hours of treatment. Because PPARγ and LXRα are important transcriptional factors for ABCA1, quercetin-induced up-regulation of ABCA1 may be mediated by increased expression levels of the PPARγ and LXRα genes. Furthermore, quercetin-enhanced cholesterol efflux from differentiated THP-1 cells to both high-density lipoprotein (HDL) and apolipoprotein A1. Quercetin at the dose of 0.15 μM elevated the cholesterol efflux only for HDL. At the dose of 0.3 μM, quercetin demonstrated effects both on HDL and apolipoprotein A1. Our data demonstrated that quercetin increased the expressions of PPARγ, LXRα, and ABCA1 genes and cholesterol efflux from THP-1 macrophages. Quercetin-induced expression of PPARγ and LXRα might subsequently affect up-regulation of their target gene ABCA1. Taken together, ingestion of quercetin or quercetin-rich foods could be an effective way to improve cholesterol efflux from macrophages, which would contribute to lowering the risk of atherosclerosis.

The role of vitamin D in toxic metal absorption: a review

Vitamin D increases intestinal calcium and phosphate absorption. Not so well known, however, is that vitamin D stimulates the co-absorption of other essential minerals like magnesium, iron, and zinc; toxic metals including lead, cadmium, aluminum, and cobalt; and radioactive isotopes such as strontium and cesium. Vitamin D may contribute to the pathologies induced by toxic metals by increasing their absorption and retention. Reciprocally, lead, cadmium, aluminum, and strontium interfere with normal vitamin D metabolism by blocking renal synthesis of 1,25-dihydroxyvitamin D. This is the first review of the role of the vitamin D endocrine system in metal toxicology.

Analysis of acute cellular rejection episodes in recipients of primary intestinal transplantation: a single center, 11-year experience

Intestinal transplantation has evolved over the years with major improvements in patient and graft survival. Acute cellular rejection of the intestine, however, still remains one of the most challenging aspects of postoperative management. We analyzed retrospectively collected data from 209 recipients of primary intestinal grafts at our institution over the past 11 years. A total of 290 episodes of biopsy-proven rejection requiring clinical treatment were analyzed. Rejection episodes doubled in length, on average, with each increasing grade (mild, moderate, severe). We observed increased incidence of overall rejection and particularly severe rejection in recipients of isolated intestinal and liver-intestine grafts in comparison with multivisceral grafts. Two rejection history variables had a significant negative impact on graft survival: the occurrence of a severe rejection episode and a rejection episode lasting >or=21 days. The lower incidence rate of severe rejection in recipients of multivisceral grafts might be due to a combination of increased donor lymphatic tissue and larger load of donor-derived immune competent cells present in the graft. The development of more effective monitoring and treatment protocols to prevent the occurrence of severe and/or lengthy rejection episodes is of critical importance for intestinal graft survival.

Expanded use of transplantation techniques: abdominal wall transplantation and intestinal autotransplantation

Surgical principles and techniques derived from organ transplantation surgery can provide novel applications in general surgery. We present an update on our 5-year experience with intestinal autotransplantation and abdominal wall transplantation. Nine patients underwent intestinal or multivisceral transplantation with the addition of 10 abdominal wall grafts to cover the large open areas from previous surgeries. Seven patients underwent near-total abdominal evisceration, ex vivo resection of masses at the base of the mesentery, followed by intestinal autotransplantation; 44% of the abdominal wall graft recipients are alive, but none of the fatalities were related to the graft itself. In two cases the graft had to be removed due to venous thrombosis. Of patients with intestinal autotransplants, 71% are alive with two mortalities due to recurrent metastatic malignancy. In only one case, the intestinal autograft had to be removed because of venous thrombosis. All surviving patients but one are on a regular diet; two are on supplemental enteral feeds. These results show that anastomotic and resection techniques derived from the experience in solid organ transplant can be utilized in complex wound closure, as is the case of abdominal wall transplantation, or resection of large retroperitoneal tumors with intestinal autotransplantation.

Production of Poly(ε-Caprolactone)/Hydroxyapatite Composite Scaffolds with a Tailored Macro/Micro-Porous Structure, High Mechanical Properties, and Excellent Bioactivity

We produced poro-us poly(ε-caprolactone) (PCL)/hydroxyapatite (HA) composite scaffolds for bone regeneration, which can have a tailored macro/micro-porous structure with high mechanical properties and excellent in vitro bioactivity using non-solvent-induced phase separation (NIPS)-based 3D plotting. This innovative 3D plotting technique can create highly microporous PCL/HA composite filaments by inducing unique phase separation in PCL/HA solutions through the non-solvent-solvent exchange phenomenon. The PCL/HA composite scaffolds produced with various HA contents (0 wt %, 10 wt %, 15 wt %, and 20 wt %) showed that PCL/HA composite struts with highly microporous structures were well constructed in a controlled periodic pattern. Similar levels of overall porosity (~78 vol %) and pore size (~248 µm) were observed for all the PCL/HA composite scaffolds, which would be highly beneficial to bone tissue regeneration. Mechanical properties, such as ultimate tensile strength and compressive yield strength, increased with an increase in HA content. In addition, incorporating bioactive HA particles into the PCL polymer led to remarkable enhancements in in vitro apatite-forming ability.

Influence of quercetin-rich onion peel extracts on adipokine expression in the visceral adipose tissue of rats

We examined the effects of quercetin-rich onion peel extract supplementation on adipokine expressions from adipose tissues in a diet-induced obese animal model. Male Sprague-Dawley rats (n = 24) were randomly assigned into control (n = 8), high fat diet (HF, n = 8) and high fat diet with onion peel extract (HFOE, n = 8). After 8 weeks, serum biochemical parameters, weights of adipose tissues (epididymal, perirenal and mesenteric fats) and adipokine mRNA levels (adiponectin, IL (interleukin)-6 and visfatin) along with PPAR (peroxisome proliferator-activated receptor) γ2 from adipose tissues were measured. After the 8 week supplementation, mesenteric fat weights were lower in the HFOE group than the HF group (p < 0.05). Adiponectin mRNA levels (mesenteric fats) were remarkably higher in the HFOE group than the other groups (p < 0.05 for both). Levels of PPARγ2 mRNA (mesenteric fats) were significantly higher in the HF group (p < 0.05) than those in the control group, but those in the HFOE group were not different from those in the control group. The IL-6 mRNA levels (perirenal and mesenteric fats) were higher in the HF and HFOE groups, but those in the HFOE group were slightly lower than those in the HF group. In conclusion, quercetin-rich onion peel extract supplementation influenced adipokine expressions, particularly from mesenteric fat, addressing the modulatory effect of this substance on obesity-induced inflammation.

The myokine meteorin-like (metrnl) improves glucose tolerance in both skeletal muscle cells and mice by targeting AMPKα2

Meteorin‐like (metrnl) is a recently identified adipomyokine that beneficially affects glucose metabolism; however, its underlying mechanism of action is not completely understood. We here show that the level of metrnl increases in vitro under electrical pulse stimulation and in vivo in exercised mice, suggesting that metrnl is secreted during muscle contractions. In addition, metrnl increases glucose uptake via the calcium‐dependent AMPKα2 pathway in skeletal muscle cells and increases the phosphorylation of HDAC5, a transcriptional repressor of GLUT4, in an AMPKα2‐dependent manner. Phosphorylated HDAC5 interacts with 14‐3‐3 proteins and sequesters them in the cytoplasm, resulting in the activation of GLUT4 transcription. An intraperitoneal injection of recombinant metrnl improved glucose tolerance in mice with high‐fat‐diet‐induced obesity or type 2 diabetes, but not in AMPK β1β2 muscle‐specific null mice. Metrnl improves glucose metabolism via AMPKα2 and is a promising therapeutic candidate for glucose‐related diseases such as type 2 diabetes.

Insights into eukaryotic multistep phosphorelay signal transduction revealed by the crystal structure of Ypd1p from Saccharomyces cerevisiae

"Two-component" phosphorelay signal transduction systems constitute a potential target for antibacterial and antifungal agents, since they are found exclusively in prokaryotes and lower eukaryotes (yeast, fungi, slime mold, and plants) but not in mammalian organisms. Saccharomyces cerevisiae Ypd1p, a key intermediate in the osmosensing multistep phosphorelay signal transduction, catalyzes the phosphoryl group transfer between response regulators. Its 1.8 A structure, representing the first example of a eukaryotic phosphorelay protein, contains a four-helix bundle as in the HPt domain of Escherichia coli ArcB sensor kinase. However, Ypd1p has a 44-residue insertion between the last two helices of the helix bundle. The side-chain of His64, the site of phosphorylation, protrudes into the solvent. The structural resemblance between Ypd1p and ArcB HPt domain suggests that both prokaryotes and lower eukaryotes utilize the same basic protein fold for phosphorelay signal transduction. This study sheds light on the best characterized eukaryotic phosphorelay system.

Blue light effect on retinal pigment epithelial cells by display devices

Blue light has high photochemical energy and induces cell apoptosis in retinal pigment epithelial cells. Due to its phototoxicity, retinal hazard by blue light stimulation has been well demonstrated using high intensity light sources. However, it has not been studied whether blue light in the displays, emitting low intensity light, such as those used in today's smartphones, monitors, and TVs, also causes apoptosis in retinal pigment epithelial cells. We attempted to examine the blue light effect on human adult retinal epithelial cells using display devices with different blue light wavelength ranges, the peaks of which specifically appear at 449 nm, 458 nm, and 470 nm. When blue light was illuminated on A2E-loaded ARPE-19 cells using these displays, the display with a blue light peak at a shorter wavelength resulted in an increased production of reactive oxygen species (ROS). Moreover, the reduction of cell viability and induction of caspase-3/7 activity were more evident in A2E-loaded ARPE-19 cells after illumination by the display with a blue light peak at a shorter wavelength, especially at 449 nm. Additionally, white light was tested to examine the effect of blue light in a mixed color illumination with red and green lights. Consistent with the results obtained using only blue light, white light illuminated by display devices with a blue light peak at a shorter wavelength also triggered increased cell death and apoptosis compared to that illuminated by display devices with a blue light peak at longer wavelength. These results show that even at the low intensity utilized in the display devices, blue light can induce ROS production and apoptosis in retinal cells. Our results also suggest that the blue light hazard of display devices might be highly reduced if the display devices contain less short wavelength blue light.

Steroid-free induction and preemptive antiviral therapy for liver transplant recipients with hepatitis C: a preliminary report from a prospective randomized study

Recurrence of hepatitis C (HepC) has been a most difficult dilemma in liver transplantation (OLT) because the effects of immunosuppression with steroid, mycophenolate mofetil (MMF) calcineurin antagonists, and anti-interleukin-2 antibody as well as the role of preemptive antiviral therapy are uncertain. In this study, we randomized OLT recipients with HepC into two treatment arms: tacrolimus+daclizumab+MMF (study arm) versus tacrolimus+steroids+MMF (control arm). The study arm only received steroids for the treatment of biopsy-proven rejection episodes. Both arms received preemptive anti-viral therapy with Pegasys and ribavirin. The 39 enrolled patients (among 50 to be enrolled) have median follow-up of 458 days with 23 patients (8 in study arm, 15 in control arm) having reached 1 year. The incidences of rejection episodes within 0 to 3 months, 3 to 6 months, and 6 to 12 months were (study vs control): 0% vs 28%; 0% vs 6%; and 13% vs 20%; respectively (P = NS). The 1-year protocol biopsies showed advanced fibrosis (stage 3 or greater) in 20% (3 of 15) of the control arm, but none (0 of 7) of the study arm (P = NS). We compared anticipated side effects of steroids in the first 3 months (study vs control): hypertension (36% vs 58%, P = NS), PTDM (7% vs 43%, P = .02), and wound infections (14% vs 37%, P = NS). In conclusion, liver transplant recipients with HepC tolerate a steroid-free protocol. There was a trend toward reduced steroid side effects and a lower incidence of advanced fibrosis in 1-year biopsy samples among patients receiving the steroid-free protocol.

The Impact of Campath 1H Induction in Adult Liver Allotransplantation

BACKGROUND

We report our experience with Campath 1H in adult liver allotransplantation.

METHODS

Between December 2001 and February 2004, 77 patients underwent liver transplantation using Campath 1H induction and low-dose maintenance tacrolimus immunosuppression. The control group consisted of 50 patients with similar baseline characteristics and the same eligibility criteria, transplanted under our standard Tacrolimus/steroids regimen. Hepatitis C patients were excluded from the study.

RESULTS

Patient and graft survival were similar for both groups. The incidence of rejection was significantly lower in the Campath vs the control group (51% vs 65% at 12 months, P = .009). Tacrolimus trough levels and conversion from Tacrolimus or the addition of other immunosuppressive drugs due to nephrotoxicity were also significantly lower in the Campath 1H group.

CONCLUSION

Campath 1H induction with low-dose Tacrolimus maintenance immunosuppression is an effective regimen in reducing acute rejection in adult liver transplantation, while maintaining lower tacrolimus levels and less nephrotoxicity than our conventional immunosuppressive regimen.