Identification of a Polyketide Synthase Gene in the Synthesis of Phleichrome of the Phytopathogenic Fungus Cladosporium phlei

Phleichrome, a pigment produced by the phytopathogenic fungus Cladosporium phlei, is a fungal perylenequinone whose photodynamic activity has been studied intensively. To determine the biological function of phleichrome and to engineer a strain with enhanced production of phleichrome, we identified the gene responsible for the synthesis of phleichrome. Structural comparison of phleichrome with other fungal perylenequinones suggested that phleichrome is synthesized via polyketide pathway. We recently identified four different polyketide synthase (PKS) genes encompassing three major clades of fungal PKSs that differ with respect to reducing conditions for the polyketide product. Based on in silico analysis of cloned genes, we hypothesized that the non-reducing PKS gene, Cppks1, is involved in phleichrome biosynthesis. Increased accumulation of Cppks1 transcript was observed in response to supplementation with the application of synthetic inducer cyclo-(l-Pro-l-Phe). In addition, heterologous expression of the Cppks1 gene in Cryphonectria parasitica resulted in the production of phleichrome. These results provide convincing evidence that the Cppks1 gene is responsible for the biosynthesis of phleichrome.

A regulatory gene network related to the porcine umami taste receptor (TAS1R1/TAS1R3)

Taste perception plays an important role in the mediation of food choices in mammals. The first porcine taste receptor genes identified, sequenced and characterized, TAS1R1 and TAS1R3, were related to the dimeric receptor for umami taste. However, little is known about their regulatory network. The objective of this study was to unfold the genetic network involved in porcine umami taste perception. We performed a meta-analysis of 20 gene expression studies spanning 480 porcine microarray chips and screened 328 taste-related genes by selective mining steps among the available 12,320 genes. A porcine umami taste-specific regulatory network was constructed based on the normalized coexpression data of the 328 genes across 27 tissues. From the network, we revealed the 'taste module' and identified a coexpression cluster for the umami taste according to the first connector with the TAS1R1/TAS1R3 genes. Our findings identify several taste-related regulatory genes and extend previous genetic background of porcine umami taste.

Long-term control of diabetes in immunosuppressed nonhuman primates (NHP) by the transplantation of adult porcine islets

Pig islets are an alternative source for islet transplantation to treat type 1 diabetes (T1D), but reproducible curative potential in the pig-to-nonhuman primate (NHP) model has not been demonstrated. Here, we report that pig islet grafts survived and maintained normoglycemia for >6 months in four of five consecutive immunosuppressed NHPs. Pig islets were isolated from designated pathogen-free (DPF) miniature pigs and infused intraportally into streptozotocin-induced diabetic rhesus monkeys under pretreatment with cobra venom factor (CVF), anti-thymocyte globulin (ATG) induction and maintenance with anti-CD154 monoclonal antibody and low-dose sirolimus. Ex vivo expanded autologous regulatory T cells were adoptively transferred in three recipients. Blood glucose levels were promptly normalized in all five monkeys and normoglycemia (90-110 mg/dL) was maintained for >6 months in four cases, the longest currently up to 603 days. Intravenous glucose tolerance tests during the follow-up period showed excellent glucose disposal capacity and porcine C-peptide responses. Adoptive transfer of autologous regulatory T cells was likely to be associated with more stable and durable normoglycemia. Importantly, the recipients showed no serious adverse effects. Taken together, our results confirm the clinical feasibility of pig islet transplantation to treat T1D patients without the need for excessive immunosuppressive therapy.

Chemopreventive Action of Anthocyanin-rich Black Soybean Fraction in APC (Min/+) Intestinal Polyposis Model

BACKGROUND

Anthocyanins have been shown to inhibit cancer cell growth by suppressing oxidative stress and inflammatory responses. The purpose of this study was to investigate the effects of an anthocyanin-rich extract (AE) from black soybean coat on intestinal carcinogenesis.

METHODS

Apc (Min/+) mice were fed a diet of 0.2% or 0.5% AE for 7 weeks. We analyzed the number of intestinal tumors, oxidative stress and inflammatory markers associated with β-catenin and cytosolic phospholipase A2 (cPLA2) signals. The number of intestinal tumors, and cellular expression of β-catenin were determined.

RESULTS

The number of intestinal tumors was significantly lower in mice fed a 0.5% AE diet compared to those of the other groups. Cytosolic β-catenin expression was significantly decreased in the AE supplemented groups compared to that of the control animals. In addition, mucosa expression of cyclooxygenase-2 and cPLA2 were also significantly decreased in the 0.5% AE group, by 32% and 62%, respectively, compared to the control group.

CONCLUSIONS

These results suggest that dietary AE reduced the development of intestinal tumors, possibly through the ability to suppress oxidative stresses, decreasing inflammatory responses mediated by β-catenin associated signals.

The use of statins for the treatment of depression in patients with acute coronary syndrome

This study aimed to investigate the effect of statins for the treatment of depression in individuals with acute coronary syndrome (ACS). We used 1-year follow-up data of a 24-week double-blind, placebo-controlled trial of escitalopram and a naturalistic prospective observational cohort study. Of 446 participants with comorbid depressive disorders and ACS at baseline, 300 participated in a randomised escitalopram trial and the remaining 146 participated in a naturalistic observational study. The participants in the two studies were approached for a 1-year follow-up investigation. Treatment response rates, defined as a ⩾ 50% reduction in the Hamilton Depression Rating Scale (HAM-D) and Beck Depression Inventory (BDI) scores, were used as the outcome variables. In the escitalopram trial, both HAM-D and BDI response rates were highest in patients taking escitalopram and statins together and lowest in patients receiving neither medication. Logistic regression analyses revealed that statin use was significantly associated with higher response rates on both the HAM-D and BDI at 1 year, whereas no such associations were found for escitalopram. In the naturalistic observational study, the response rates at 1 year did not differ significantly by statin use. Instead, the HAM-D response rate was significantly higher in patients taking lipophilic statins than in those who did not. In conclusion, statins may be effective for the treatment of depression independent of medical status and escitalopram use, and they may potentiate the antidepressant action of serotonergic antidepressants in patients with ACS.

The cortical contrast accumulation from brain computed tomography after endovascular treatment predicts symptomatic hemorrhage

BACKGROUND AND PURPOSE

The prognostic value of contrast accumulation from non-contrast brain computed tomography taken immediately after endovascular reperfusion treatment in acute ischaemic stroke patients to predict symptomatic hemorrhage was studied.

METHODS

Between July 2007 and August 2014, acute anterior circulation ischaemic stroke patients who were treated by intra-arterial thrombolysis or thrombectomy were included. Contrast accumulation was defined as a high attenuation area from non-contrast brain computed tomography immediately taken after endovascular reperfusion treatment, and patients were categorized into three groups according to the presence and location of contrast: (i) negative, (ii) cortical involvement and (iii) non-cortical involvement. The rates of symptomatic hemorrhage after 24 h and functional outcome at discharge were compared between patients with and without cortical involvement.

RESULTS

Of 64 patients who were treated by endovascular intervention, contrast accumulation was detected in 56, including 33 patients with cortical involvement and 23 patients without cortical involvement. The cortical involvement pattern was more frequently associated with symptomatic hemorrhage (13 vs. 1 patient, P = 0.003) and with grave outcome at discharge with modified Rankin Scale 5 or 6 (14 vs. 4, P = 0.048) than the non-cortical involvement group. Multivariate logistic regression analysis including initial collateral status and occlusion site disclosed that cortical involvement pattern independently predicted symptomatic hemorrhage after endovascular treatment (odds ratio 19.0, confidence interval 1.6-227.6, P = 0.020).

CONCLUSION

Our study provides evidence that the cortical involvement of contrast accumulation is associated with symptomatic hemorrhage after endovascular reperfusion treatment.

Influence of hepatitis B virus reactivation on the recurrence of HBV-related hepatocellular carcinoma after curative resection in patients with low viral load

It is unclear whether the reactivation of hepatitis B virus (HBV) influences the prognosis of hepatocellular carcinoma (HCC) after resection in patients with chronic hepatitis B. The aim of this study was to identify the influence of HBV reactivation on the recurrence of hepatitis B-related HCC after curative resection in patients with low viral load (HBV DNA <2000 IU/mL). We retrospectively analysed a total of 130 patients who underwent curative resection for HBV-related early stage HCC (single nodule; <5 cm/two or three nodules; <3 cm) with pre-operative HBV DNA levels <2000 IU/mL with serial HBV DNA tests. The predictive factors including HBV reactivation for the recurrence of HBV-related HCC after curative resection were investigated. Fifty-three patients (41%) had HBV reactivation after resection among 130 patients. HBV reactivation was observed in 22 of 53 patients with undetectable baseline HBV DNA and in 31 of 77 patients with detectable baseline HBV DNA. Cumulative recurrence rates after resection at 1, 2 and 3 years were 17.0%, 23.3% and 31.4%, respectively. The multivariable analysis demonstrated that the risk factors for the recurrence were the presence of microvascular invasion (hazard ratio (HR) 2.62, P = 0.003), multinodularity (HR 4.61, P = 0.005), HBV reactivation after resection (HR 2.03, P = 0.032) and HBeAg positivity (HR 2.06, P = 0.044). HBV reactivation after curative resection is associated with the recurrence of HBV-related HCC in patients with low viral load.

The flavone eupatilin inhibits eotaxin expression in an NF-κB-dependent and STAT6-independent manner

The CC chemokine eotaxin contributes to epithelium-induced inflammation in airway diseases such as asthma. Eupatilin (5,7-dihydroxy-3',4',6'-trimethoxyflavone), a bioactive component of Artemisia asiatica Nakai (Asteraceae), is reported to inhibit the adhesion of eosinophils to bronchial epithelial cells. However, little is known about the molecular mechanism of eupatilin-induced attenuation of bronchial epithelium-induced inflammation. In this study, we investigated the effect of eupatilin on expression of eotaxin-1 (CCL11), a potent chemoattractant for eosinophils. Eupatilin significantly inhibited eotaxin expression in bronchial epithelial cells stimulated with TNF-α, while NF-κB and IκBα kinase (IKK) activities declined concurrently. Eupatilin also inhibited mitogen-activated protein kinase (MAPK) activity; however, all of these anti-inflammatory activities were reversed by MAPK overexpression. In contrast, eupatilin did not affect the signal transducer and activator of transcription 6 (STAT6) signalling in bronchial epithelial cells stimulated with IL-4. Furthermore, eupatilin significantly attenuated TNF-α-induced eosinophil migration. These results suggest that the eupatilin inhibits the signalling of MAPK, IKK, NF-κB and eotaxin-1 in bronchial epithelial cells, leading to inhibition of eosinophil migration.

Expanded criteria for liver transplantation in patients with hepatocellular carcinoma

Liver transplantation (LT) is one of the few effective treatment options for hepatocellular carcinoma (HCC). Our aim in this study was to evaluate the risk factors for HCC recurrence and propose new criteria for LT based on pretransplantation findings. One hundred eighty patients who underwent LT for HCC between 2002 and 2008 were reviewed retrospectively. Outcome measures included maximal tumor size and number of tumors revealed by radiological studies before transplantation, demographics, and tumor recurrence. Maximal tumor size >6 cm, >7 tumors, and alpha-fetoprotein (AFP) levels >1000 ng/mL were identified as independent prognostic factors of HCC recurrence in univariate and multivariate analysis. Disease-free survival rate in patients with a maximal tumor size ≤6 cm, ≤7 tumors, and/or AFP levels ≤1000 ng/mL at 1, 3, and 5 years was 97.9%, 91.5%, and 90.0%, respectively, but the 1-, 3-, and 5-year disease-free survival rate of patients who had a maximal tumor size >6 cm, >7 tumors, and/or AFP levels >1000 ng/mL was 61.9%, 47.6%, and 47.6%, respectively (P < .001). In conclusion, LT can improve the survival of patients with advanced HCC if they have a maximal tumor size ≤6 cm, tumor number ≤7, and/or AFP levels ≤1000 ng/mL.

The predictors for continuous renal replacement therapy in liver transplant recipients

BACKGROUND

Acute renal failure (ARF) after liver transplantation requiring continuous renal replacement therapy (CRRT) adversely affects patient survival. We suggested that postoperative renal failure can be predicted if a clinically simple nomogram can be developed, thus selecting potential risk factors for preventive strategy.

METHODS

We retrospectively reviewed the medical records of 153 liver transplant recipients from January 2008 to December 2011 at Severance Hospital, Yonsei University Health System, in Seoul, Korea. There were 42 patients treated with CRRT (20 and 22 patients received transplants from living and deceased donors, respectively) and 115 were not. Univariate and stepwise logistic multivariate analyses were performed. A clinical nomogram to predict postoperative CRRT application was constructed and validated internally.

RESULTS

Hepatic encephalopathy (HEP; odds ratio OR, 5.47), deceased donor liver donations (OR, 3.47), Model for End-Stage Liver Disease (MELD) score (OR, 1.09), intraoperative blood loss (L; OR, 1.16), and tumor (hepatocellular carcinoma) as the indication for liver transplantation (OR, 0.11) were identified as independent predictive factors for postoperative CRRT on multivariate analysis. A clinical prediction model constructed for calculating the probability of CRRT post-transplantation was 1.7000 × HEP + [-4.5427 + 1.2440 × (deceased donor) + 0.0830 × (MELD score) + 0.000149 × the amount of intraoperative bleeding (L) - 2.1785 × tumor]. The validation set discriminated well with an area under the curve (AUC) of 0.90 (95% confidence interval, 0.85-0.95). The predicted and the actual probabilities were calibrated with the clinical nomogram.

CONCLUSIONS

We developed a predictive model of postoperative CRRT in liver transplantation patients. Perioperative strategies to modify these factors are needed.

Characterization of NpgA, a 4'-phosphopantetheinyl transferase of Aspergillus nidulans, and evidence of its involvement in fungal growth and formation of conidia and cleistothecia for development

The null pigmentation mutant (npgA1) in Aspergillus nidulans results in a phenotype with colorless organs, decreased branching growth, delayed of asexual spore development, and aberrant cell wall structure. The npgA gene was isolated from A. nidulans to investigate these pleiomorphic phenomena of npgA1 mutant. Sequencing analysis of the complementing gene indicated that it contained a 4'-phosphopantetheinyl transferase (PPTase) superfamily domain. Enzymatic assay of the PPTase, encoded by the npgA gene, was implemented in vivo and in vitro. Loss-of-function of LYS5, which encoded a PPTase in Saccharomyces cerevisiae, was functionally complemented by NpgA, and Escherichia coli-derived NpgA revealed phosphopantetheinylation activity with the elaboration of 3'5'-ADP. Deletion of the npgA gene caused perfectly a lethal phenotype and the absence of asexual/sexual sporulation and secondary metabolites such as pigments in A. nidulans. However, a cross feeding effect with A. nidulans wild type allowed recovery from deletion defects, and phased-culture filtrate from the wild type were used to verify that the npgA gene was essential for formation of metabolites needed for development as well as growth. In addition, forced expression of npgA promoted the formation of conidia and cleistothecia as well as growth. These results indicate that the npgA gene is involved in the phosphopantetheinylation required for primary biological processes such as growth, asexual/sexual development, and the synthesis of secondary metabolites in A. nidulans.

A polymorphism in the porcine miR-208b is associated with microRNA biogenesis and expressions of SOX-6 and MYH7 with effects on muscle fibre characteristics and meat quality

MicroRNAs (miRNAs) encoded by the myosin heavy chain (MHC) genes are muscle-specific miRNAs (myomiRs) and regulate the expression of MHC isoforms in skeletal muscle. These miRNAs have been implicated in muscle fibre types and their characteristics by affecting the heterogeneity of myosin. In pigs, miR-208b and miR-499 are embedded in introns of MYH7 and MYH7b respectively. Here, we identified a novel single nucleotide polymorphism (SNP) in intron 30 of MYH7 by which porcine miR-208b is encoded. Based on the association study using a total of 487 pigs including Berkshire (n = 164), Landrace (n = 121) and Yorkshire (n = 202), the miR-208b SNP (g.17104G>A) had significant effects on the proportions of types I and IIb fibre numbers (P < 0.010) among muscle fibre characteristics and on drip loss (P = 0.012) in meat quality traits. Moreover, the SNP affected the processing of primary miR-208b into precursor miR-208b with a marginal trend towards significance (P = 0.053), thereby leading to significant changes in the levels of mature miR-208b (P = 0.009). These SNP-dependent changes in mature miR-208b levels were negatively correlated with the expression levels of its target gene, SOX-6 (P = 0.038), and positively associated with the expression levels of its host gene, MYH7 (P = 0.046). Taken together, our data suggest that the porcine miR-208b SNP differentially represses the expression of SOX-6 by regulating miRNA biogenesis, thereby affecting the expression of MYH7 and the traits of muscle fibre characteristics and meat quality.

Mycoflora dynamics analysis of Korean traditional wheat-based nuruk

The growing popularity of traditional Korean alcoholic beverages has led to a demand for quality enhancement of the traditional starter culture nuruk, which consists primarily of wheat. Therefore, this study focused on mycoflora characterization and the temporal variations in traditional wheat-based nuruks fermented at two representative traditional temperature conditions for 30 days. Nuruk A was fermented at a constant temperature of 36°C for 30 days and nuruk B was fermented at a high initial temperature of 45°C for 10 days followed by 35°C for 20 days. The average mycoflora load in the two different nuruk conditions did not vary significantly between the 0 and 30 day cultures, and a maximum load of 8.39 log CFU/g was observed for nuruk A on culture day 3 and 7.87 log CFU/g for nuruk B on culture day 30. Within two samples, pH was negatively correlated with temporal changes in mycoflora load. The pH of nuruk A was significantly lower than that of nuruk B at all of the time points evaluated. Culture-dependent characterization led to the identification of 55 fungal isolates belonging to 9 genera and 15 species, with the most prominent genera comprising Lichtheimia, Penicillium, Trametes, Aspergillus, Rhizomucor, and Mucor. A total of 25 yeast isolates were characterized belonging to 6 genera and 7 species, the most prominent among which were Rhodotorula, Pichia, Debaryomyces, Saccharomycopsis, and Torulospora. Mycofloral community dynamics analysis revealed that both samples A and B varied considerably with respect to the fungal communities over a span of 30 days.

Transformation of a layered perovskite to a defect perovskite via cooperative Li-insertion and O/N substitution

Defect perovskite oxynitrides containing lithium on the octahedral sites, i.e., Sr(1-x)(Li(x)Ta(1-x))(O(3.5-3x-3y)N(2y)), were produced by the ammonolytic heating of a layered perovskite, Sr2Ta2O7, with Li2CO3. The above phase evolution involved the thermal diffusion of Li(+) into the Sr2Ta2O7 lattice and concurrent 3O(2-) → 2N(3-) substitution. The concentrations of Li, N, and anion vacancies in the product oxynitride could be controlled by adjusting the Li2CO3 to Sr2Ta2O7 ratio in the reactant mixture. This study identified three different compositions, Sr(0.92)Li(0.08)Ta(0.92)O(1.91)N(0.89), Sr(0.83)Li(0.17)Ta(0.83)O(1.88)N(0.74) and Sr(0.73)Li(0.27)Ta(0.73)O(1.82)N(0.58), where an increase in the Li composition accompanied decreases in the a- and c-parameters of the tetragonal cell, along with an increase in the band gap. Neutron diffraction and solid state (7)Li nuclear magnetic resonance spectroscopy of Sr(1-x)(Li(x)Ta(1-x))(O(3.5-3x-3y)N(2y)) showed that Li occupied the octahedral site, and these oxynitrides exhibited enhanced bond covalency compared to similar oxides.

Changes in the mycovirus (LeV) titer and viral effect on the vegetative growth of the edible mushroom Lentinula edodes

This study attempted to cure the edible mushroom Lentinula edodes strain FMRI0339 of the L. edodes mycovirus (LeV) in order to obtain an isogenic virus-free fungal strain as well as a virus-infected strain for comparison. Mycelial fragmentation, followed by being spread on a plate with serial dilutions resulted in a virus-free colony. Viral absence was confirmed with gel electrophoresis after dsRNA-specific virus purification, Northern blot analysis, and PCR using reverse transcriptase (RT-PCR). Once cured, all of fungal cultures remained virus-free over the next two years. Interestingly, the viral titer of LeV varied depending on the culture condition. The titer from the plate culture showed at least a 20-fold higher concentration than that grown in the liquid culture. However, the reduced virus titer in the liquid culture was recovered by transferring the mycelia to a plate containing the same medium. In addition, oxygen-depleted culture conditions resulted in a significant decrease of viral concentration, but not to the extent seen in the submerged liquid culture. Although no discernable phenotypic changes in colony morphology were observed, virus-cured strains showed significantly higher growth rates and mycelial mass than virus-infected strains. These results indicate that LeV infection has a deleterious effect on mycelial growth.

Microtubule plus end-tracking proteins play critical roles in directional growth of hyphae by regulating the dynamics of cytoplasmic microtubules in Aspergillus nidulans

Cytoplasmic microtubules (MTs) serve as a rate-limiting factor for hyphal tip growth in the filamentous fungus Aspergillus nidulans. We hypothesized that this function depended on the MT plus end-tracking proteins (+TIPs) including the EB1 family protein EBA that decorated the MT plus ends undergoing polymerization. The ebAΔ mutation reduced colony growth and the mutant hyphae appeared in an undulating pattern instead of exhibiting unidirectional growth in the control. These phenotypes were enhanced by a mutation in another +TIP gene clipA. EBA was required for plus end-tracking of CLIPA, the Kinesin-7 motor KipA, and the XMAP215 homologue AlpA. In addition, cytoplasmic dynein also depended on EBA to track on most polymerizing MT plus ends, but not for its conspicuous appearance at the MT ends near the hyphal apex. The loss of EBA reduced the number of cytoplasmic MTs and prolonged dwelling times for MTs after reaching the hyphal apex. Finally, we found that colonies were formed in the absence of EBA, CLIPA, and NUDA together, suggesting that they were dispensable for fundamental functions of MTs. This study provided a comprehensive delineation of the relationship among different +TIPs and their contributions to MT dynamics and unidirectional hyphal expansion in filamentous fungi.

Mycoflora and enzymatic characterization of fungal isolates in commercial meju, starter for a korean traditional fermented soybean product

Mycoflora was assessed in the commercial meju from four well-separated geographic origins. A total of 112 fungal isolates were identified by phenotypic characteristics and molecular taxonomy using sequencing the internal transcribed spacer of the rDNA and revealed 19 species from 13 genera. Enzymatic characteristics of protease and amylase, and mycotoxin production were analyzed.

Genotoxic stress/p53-induced DNAJB9 inhibits the pro-apoptotic function of p53

DNAJB9 is a recently isolated member of the molecular chaperone gene family, whose precise function is largely unknown. In the present study, we have identified DNAJB9 as an inducible gene of the tumor suppressor p53. DNAJB9 expression was induced by p53 or genotoxic stress in a p53-dependent manner, which was mediated by the Ras/Raf/ERK pathway. In addition, depletion of DNAJB9 by using siRNAs greatly increased genotoxic stress/p53-induced apoptosis, suggesting that DNAJB9 inhibits the pro-apoptotic function of p53. We also found that DNAJB9 physically interacts with p53 through its J domain, through which it inhibits the pro-apoptotic function of p53. Moreover, DNAJB9 colocalized with p53 in both cytoplasm and nucleus under genotoxic conditions. Together, these results demonstrate that DNAJB9 is a downstream target of p53 that belongs to the group of negative feedback regulators of p53.