Non‐invasive transcriptomic analysis using mRNAs in skin surface lipids obtained from children with mild‐to‐moderate atopic dermatitis

Background

Specimens for analysing the molecular pathology of skin disease are generally obtained through invasive methods, such as biopsy. However, less burdensome methods are desirable for paediatric patients. We recently established a method that comprehensively analyses RNA present in sebum (skin surface lipid–RNAs: SSL‐RNAs) using a next‐generation sequencer. Using this method, biological information can be obtained from the skin in a completely non‐invasive manner.

Objectives

To verify the applicability of the SSL‐RNA method for analysis of paediatric skin and analyse the molecular pathology of mild‐to‐moderate atopic dermatitis (AD) in children.

Methods

We collected sebum specimens from the whole faces of 23 healthy children and 16 children with mild‐to‐moderate AD (eczema area and severity index (EASI) score: 5.9 ± 2.6) ranging in age from 6 months to 5 years, using an oil‐blotting film. We then extracted SSL‐RNAs from the samples and performed an AmpliSeq transcriptomic analysis.

Results

The expressions of genes related to keratinization (LCE, PSORS1C2, IVL and KRT17), triglyceride synthesis and storage (PLIN2, DGAT2 and CIDEA), wax synthesis (FAR2), ceramide synthesis (GBA2, SMPD3 and SPTLC3), antimicrobial peptides (DEFB1) and intercellular adhesion (CDSN), all of which are related to the skin barrier, are lower in children with AD than in healthy children. The children with AD also have higher expression of CCL17, a Th2‐cytokine and an increased Th2‐immune response as demonstrated by a gene set variation analysis. Moreover, KRT17 and CCL17 expression levels are significantly correlated with the EASI score.

Conclusions

Molecular changes associated with abnormal immune responses and the epidermal barrier in children with mild‐to‐moderate AD can be determined using the SSL‐RNA method. This non‐invasive method could therefore be a useful means for understanding the molecular pathology of paediatric AD.

Expression of Peroxisome Proliferator-activated Receptor-γ in the Kidneys of Cats with Chronic Kidney Disease

Peroxisome proliferator-activated receptor (PPAR)-γ plays an important role in various cellular functions and its activation exerts protective effects in kidney diseases. In the present study, chronic kidney disease in cats was examined, and changes in renal expression of PPARγ were observed by use of immunohistochemistry. In normal kidneys, nuclei of the superficial cortical tubules, medullary tubules and glomerular cells expressed PPARγ. The vascular walls (tunica media) also showed positive expression. In diseased kidneys, the expression of PPARγ varied between the cases. Some cases showed strong expression, while others had weak expression. PPARγ expression in the nuclei of infiltrating mononuclear cells was also detected in over half of the cases. Although there was no significant relationship between the expression of renal PPARγ and the severity of kidney disease, the fact that there were many cases where the expression of renal PPARγ was reduced was an important finding, and might be one of the possible mechanisms underlying feline chronic kidney diseases.

Angiopoietin-like protein 2 promotes chondrogenic differentiation during bone growth as a cartilage matrix factor

OBJECTIVE

Chondrocyte differentiation is crucial for long bone growth. Many cartilage extracellular matrix (ECM) proteins reportedly contribute to chondrocyte differentiation, indicating that mechanisms underlying chondrocyte differentiation are likely more complex than previously appreciated. Angiopoietin-like protein 2 (ANGPTL2) is a secreted factor normally abundantly produced in mesenchymal lineage cells such as adipocytes and fibroblasts, but its loss contributes to the pathogenesis of lifestyle- or aging-related diseases. However, the function of ANGPTL2 in chondrocytes, which are also differentiated from mesenchymal stem cells, remains unclear. Here, we investigate whether ANGPTL2 is expressed in or functions in chondrocytes.

METHODS

First, we evaluated Angptl2 expression during chondrocyte differentiation using chondrogenic ATDC5 cells and wild-type epiphyseal cartilage of newborn mice. We next assessed ANGPTL2 function in chondrogenic differentiation and associated signaling using Angptl2 knockdown ATDC5 cells and Angptl2 knockout mice.

RESULTS

ANGPTL2 is expressed in chondrocytes, particularly those located in resting and proliferative zones, and accumulates in ECM surrounding chondrocytes. Interestingly, long bone growth was retarded in Angptl2 knockout mice from neonatal to adult stages via attenuation of chondrocyte differentiation. Both in vivo and in vitro experiments show that changes in ANGPTL2 expression can also alter p38 mitogen-activated protein kinase (MAPK) activity mediated by integrin α5β1.

CONCLUSION

ANGPTL2 contributes to chondrocyte differentiation and subsequent endochondral ossification through α5β1 integrin and p38 MAPK signaling during bone growth. Our findings provide insight into molecular mechanisms governing communication between chondrocytes and surrounding ECM components in bone growth activities.

Surfactant protein D inhibits activation of non-small cell lung cancer-associated mutant EGFR and affects clinical outcomes of patients

Tyrosine kinase inhibitor (TKI)-sensitive and TKI-resistant mutations of epidermal growth factor receptor (EGFR) are associated with lung adenocarcinoma. EGFR mutants were previously shown to exhibit ligand-independent activation. We have previously demonstrated that pulmonary surfactant protein D (SP-D, SFTPD) suppressed wild-type EGFR signaling by blocking ligand binding to EGFR. We herein demonstrate that SFTPD downregulates ligand-independent signaling in cells harboring EGFR mutations such as TKI-sensitive exon 19 deletion (Ex19del) and L858R mutation as well as TKI-resistant T790M mutation, subsequently suppressing cellular growth and motility. Lectin blotting and ligand blotting in lung cancer cell lines suggested that EGFR mutants express oligomannose-type N-glycans and interact with SFTPD directly. Cross-linking assay indicated that SFTPD inhibits ligand-independent dimerization of EGFR mutants. We also demonstrated that SFTPD reduced dimerization-independent phosphorylation of Ex19del and T790M EGFR mutants using point mutations that disrupted the asymmetric dimer interface. It was confirmed that SFTPD augmented the viability-suppressing effects of EGFR-TKIs. Furthermore, retrospective analysis of 121 patients with lung adenocarcinoma to examine associations between serum SFTPD levels and clinical outcome indicated that in TKI-treated patients with lung cancer harboring EGFR mutations, including Ex19del or L858R, high serum SFTPD levels correlated with a lower number of distant metastases and prolonged overall survival and progression-free survival. These findings suggest that SFTPD downregulates both TKI-sensitive and -resistant EGFR mutant signaling, and SFTPD level is correlated with clinical outcome. These findings illustrate the use of serum SFTPD level as a potential marker to estimate the efficacy of EGFR-TKIs.

Impact of inadequate initial antimicrobial therapy on mortality in patients with bacteraemic cholangitis: a retrospective cohort study

OBJECTIVES

Acute cholangitis is a common cause of bacteraemia resulting in severe sepsis or septic shock. The impact of the appropriate initial antimicrobial therapy on short-term mortality in bacteraemic cholangitis has not been well investigated.

METHODS

We conducted a retrospective cohort study of patients with bacteraemic cholangitis at two large tertiary care centres in Tokyo, Japan between 2009 and 2015. We determined the factors associated with 30-day all-cause mortality from the date of drawing the first positive blood culture, using a multivariate logistic regression analysis.

RESULTS

We identified 573 patients with bacteraemic cholangitis (median age, 77 years; male, 58.3%). The 30-day all-cause mortality rate was 6.6% (38/573). Inadequate initial antimicrobial therapy occurred in 133 (23.2%) patients. Factors associated with 30-day all-cause mortality included the Charlson co-morbidity index score >3 (adjusted odds ratio (aOR) 4.12; 95% CI 1.18-14.38), jaundice (total bilirubin >2.5 mg/dL) (aOR 3.39; 95% CI 1.46-7.89), septic shock within 48 h of the first positive blood culture (aOR 3.34; 95% CI 1.42-7.89), biliary obstruction due to hepatobiliary malignancy (aOR 8.00; 95% CI 2.92-21.97), and inadequate initial antimicrobial therapy (aOR 2.78; 95% CI 1.27-6.11).

CONCLUSIONS

Inadequate initial antimicrobial therapy was an important, modifiable determinant of survival.

The role of mitochondria-derived reactive oxygen species in the pathogenesis of non-steroidal anti-inflammatory drug-induced small intestinal injury

Non-steroidal anti-inflammatory drugs (NSAIDs) have been implemented in clinical settings for a long time for their anti-inflammatory effects. With the number of NSAID users increasing, gastroenterological physicians and researchers have worked hard to prevent and treat NSAID-induced gastric mucosal injury, an effort that has for the large part being successful. However, the struggle against NSAID-induced mucosal damage has taken on a new urgency due to the discovery of NSAID-induced small intestinal mucosal injury. Although the main mechanism by which NSAIDs induce small intestinal mucosal injury has been thought to depend on the inhibitory effect of NSAIDs on cyclooxygenase (COX) activity, recent studies have revealed the importance of mitochondria-derived reactive oxygen species (ROS) production, which occurs independently of COX-inhibition. ROS production is an especially important factor in the increase of small intestinal epithelial cell permeability, an early stage in the process of small intestinal mucosal injury. By clarifying the precise mechanism, together with its clinical features using novel endoscopy, effective strategies for preventing NSAID-induced small intestinal damage, especially targeting mitochondria-derived ROS production, may be developed.

Endoplasmic reticulum stress-induced apoptosis contributes to articular cartilage degeneration via C/EBP homologous protein

OBJECTIVE

When endoplasmic reticulum (ER) stress, i.e., the excessive accumulation of unfolded proteins in ER, endangers homeostasis, apoptosis is induced by C/EBP homologous protein (Chop). In osteoarthritis (OA) cartilage, Chop expression and apoptosis increase as degeneration progresses. We investigated the role of Chop in murine chondrocyte apoptosis and in the progression of cartilage degeneration.

METHOD

We induced experimental OA in Chop-knockout (Chop(-/-)) mice by medial collateral ligament transection and meniscectomy and compared cartilage degeneration, apoptosis, and ER stress in Chop(-/-)- and wild-type (Chop(+/+)) mice. In our in vitro experiments we treated murine Chop(-/-) chondrocytes with the ER stress inducer tunicamycin (TM) and evaluated apoptosis, ER stress, and chondrocyte function.

RESULTS

In vivo, the degree of ER stress was similar in Chop(-/-)- and Chop(+/+) mice. However, in Chop(-/-) mice apoptosis and cartilage degeneration were lower by 26.4% and 42.4% at 4 weeks, by 26.8% and 44.9% at 8 weeks, and by 26.9% and 32.3% at 12 weeks after surgery than Chop(+/+) mice, respectively. In vitro, the degree of ER stress induction by TM was similar in Chop(-/-)- and Chop(+/+) chondrocytes. On the other hand, apoptosis was 55.3% lower and the suppression of collagen type II and aggrecan mRNA was 21.0% and 23.3% less, and the increase of matrix metalloproteinase-13 mRNA was 20.0% less in Chop(-/-)- than Chop(+/+) chondrocytes.

CONCLUSION

Our results indicate that Chop plays a direct role in chondrocyte apoptosis and that Chop-mediated apoptosis contributes to the progression of cartilage degeneration in mice.

Effect of chronic kidney disease on excessive daytime sleepiness in Parkinson disease

BACKGROUND AND PURPOSES

Excessive daytime sleepiness (EDS) is a common sleep disorder in patients with Parkinson disease (PD). Non-ergot dopamine agonists increase the risk of unanticipated sleep episodes.

OBJECTIVE

  We aimed to assess the influence of renal function on EDS in patients with PD.

METHODS

Sixty-two patients treated with ropinirole or pramipexole were recruited for this study. We evaluated the historical and clinical characteristics including the motor symptom rating scales, Epworth Sleepiness Scale (ESS), and estimated glomerular filtration rate (eGFR). An ESS score of 10 or greater was defined as EDS. Participants with eGFR < 60 ml/min/1.73 m(2) were determined to have chronic kidney disease (CKD). Multiple logistic regression analysis was performed to determine the predictive factors of EDS.

RESULTS

Chronic kidney disease was found to be a significant predictive factor for EDS in all patients (P = 0.014). We observed a negative correlation between the severity of daytime sleepiness and renal function in patients treated with pramipexole alone (r(s) = -0.637, P < 0.001).

CONCLUSIONS

Chronic kidney disease may be a risk factor for EDS, especially in patients treated with pramipexole, which is directly excreted in the urine.

Clonal distribution of enterotoxigenic Staphylococcus aureus on handles of handheld shopping baskets in supermarkets

AIMS

Shopping carts and handheld shopping baskets in supermarkets are subject to accidental bacterial contamination through contacts with a variety of food. We investigated the prevalence of Staphylococcus aureus on the handles of handheld shopping baskets in four supermarkets distantly located in Osaka district, Japan.

METHODS AND RESULTS

Fifty two strains of Staph. aureus were isolated from 760 basket handles. Among these, six strains were positive for staphylococcal enterotoxin B (SEB) production, representing 12% of total. This SEB producer ratio is considerably higher than among Staph. aureus isolated from nasal swabs of the supermarket workers (2%) and from independently collected clinical specimens (4%). These SEB-producing Staph. aureus strains from the basket handles are clonal and belong to ST12. Coagulase typing showed that they are in group VII, which is the most common cause of food poisoning in Japan. Biofilm assays indicated that SEB gene (seb)-positive strains including this clone produced a significantly higher amount of biofilm than seb-negative strains.

CONCLUSIONS

The frequent isolation of seb-positive Staph. aureus on shopping basket handles raises the possibility that they could be a hidden reservoir for Staph. aureus with a potential to cause food poisoning and draws attention to the importance of shopping basket sanitation.

Genome-wide single-nucleotide polymorphism arrays in endometrial carcinomas associate extensive chromosomal instability with poor prognosis and unveil frequent chromosomal imbalances involved in the PI3-kinase pathway

Endometrial cancer is one of the tumor types in which either chromosomal instability (CIN) or microsatellite instability (MSI) may occur. It is known to possess mutations frequently in the Ras-PI3K (phosphatidylinositol 3'-kinase) pathway. We performed a comprehensive genomic survey in 31 endometrial carcinomas with paired DNA for chromosomal imbalances (25 by the 50K and 6 by the 250K single-nucleotide polymorphism (SNP) array), and screened 25 of the 31 samples for MSI status and mutational status in the Ras-PI3K pathway genes. We detected five or more copy number changes (classified as CIN-extensive) in 9 (29%), 1 to 4 changes (CIN-intermediate) in 17 (55%) and no changes (CIN-negative) in 5 (16%) tumors. Positive MSI was less common in CIN-extensive tumors (14%), compared with CIN-intermediate/negative tumors (50%), and multivariate analysis showed that CIN-extensive is an independent poor prognostic factor. SNP array analysis unveiled copy number neutral LOH at 54 loci in 13 tumors (42%), including four at the locus of PTEN. In addition to eight (26%) tumors with PTEN deletions, we detected chromosomal imbalances of NF1, K-Ras and PIK3CA in four (13%), four (13%) and six (19%) tumors, respectively. In all, 7 of the 9 CIN-extensive tumors harbor deletions in the loci of PTEN and/or NF1, whereas all the 10 MSI-positive tumors possess PTEN, PIK3CA and/or K-Ras mutations. Our results showed that genomic alterations in the Ras-PI3K pathway are remarkably widespread in endometrial carcinomas, regardless of the type of genomic instability, and suggest that the degree of CIN is a useful biomarker for prognosis in endometrial carcinomas.

Sucrose feeding at weaning alters the preference for sucrose in adolescence

The present studies were undertaken to examine the hypothesis that sucrose feeding at weaning may alter the preference for sucrose in the adolescence. Chronological changes of hypothalamic dopamine (DA), its metabolite, 3,4-dihydroxy-phenylacetic acid (DOPAC) and norepinephrine (NE) contents were also measured by HPLC. In 21 day-aged rats, 10% sucrose or water was given as drinking water for 3 weeks. From 9 weeks, all animals were maintained under a free choice between 30% sucrose solution and water. Sucrose-ingested rats more preferred to 30% sucrose solution than control rats and body weight gain of sucrose group was significantly greater than that of controls. Hypothalamic DA content was significantly decreased at 6 and 13 weeks and the DOPAC/DA ratio increased at 3, 6, and 13 weeks later. In contrast, hypothalamic NE concentration was not changed at all. The data obtained herein suggest that sucrose feeding at weaning alters the preference for sucrose, resulting in an overweight gain, and that the observed increase of hypothalamic DA metabolism may be involved in the altered preference for sucrose.

Reduced ability of neutrophils to produce active oxygen species in streptozotocin-induced diabetic rats

We investigated a possible alteration in the ability of neutrophils to produce active oxygen species in streptozotocin (STZ)-induced diabetic rats. The production of superoxide of the neutrophils was assessed by luminol-dependent chemiluminescence (LDCL) after the stimulation by opsonized zymosan. Four days after STZ (60 mg/kg, ip) injection, blood glucose level increased by 399 +/- 9 mg/dl and the LDCL activity was significantly reduced in diabetic rats (control group: 5.12 +/- 1.53 KC/min2/10(6) cells, STZ group: 1.10 +/- 0.07 KC/min2/10(6) cells, p less than 0.01). At Day 17, blood glucose level was maintained high (598 +/- 8 mg/dl) and the LDCL activity (1.01 +/- 0.39 KC/min2/10(6) cells) was almost at the same level as that of diabetic rats at Day 4. Subcutaneous injection of insulin for 10 consecutive days increased the LDCL activity of diabetic rats in a dose-dependent manner (vehicle: 0.82 +/- 0.27 KC/min2/10(6) cells, 0.04 U/day: 1.61 +/- 0.09 KC/min2/10(6) cells, 0.40 U/day: 1.99 +/- 0.47 KC/min2/10(6) cells, 4.00 U/day: 3.33 +/- 0.43 KC/min2/10(6) cells). The data obtained herein indicate that an increased susceptibility to bacterial infection in diabetic rats results from impaired neutrophil function to produce active oxygen species.

Colonic temperature was not changed in the development of obesity after ovariectomy

We tested the hypothesis that altered heat production ability after ovariectomy may be involved in the development of obesity. Two weeks after ovariectomy, food intake of ovariectomized (Ovx) rats was increased and body weight gain was obvious, compared with sham-operated animals. However, colonic temperature of Ovx rats was not different from that of sham-operated animals. Food intake of Ovx rats was similar with that of sham-operated rats at 8 weeks later. In this period, colonic temperature of Ovx rats was not different from that of sham-operated animals and diurnal rhythmicity was maintained. The present data suggested that changes in heat production may be not an important inducer of obesity in both the dynamic and static phases of the development of obesity after ovariectomy.

Hypothermia in insulin-treated obese rats

Changes of colonic temperature were investigated to examine a mechanism of hypothermia in the obese rats which received subcutaneous administration of intermediate type-insulin (8 U/day) for 8 weeks. Although diurnal rhythmicity of colonic temperature levels was maintained similarly with those of vehicle-injected controls, the overall colonic temperature levels were significantly lowered in insulin-treated animals. In the condition of cold exposure at 5 degrees C, colonic temperature levels of insulin-treated animals were immediately and significantly decreased at 60 minutes after the start of cold exposure. The data obtained herein demonstrated that hyperinsulinemia accompanying with hyperphagia should be profoundly involved in hypothermia, observed in various experimental models of obesity.

Altered monoamine metabolism in the hypothalamus of the genetically obese yellow (Ay/a) mouse

Changes in hypothalamic monoamine metabolism were investigated in the genetically obese yellow (Ay/a) mouse. At the age of 6 weeks when there was no difference in body weight between black (a/a) and yellow (Ay/a) mice, the contents of norepinephrine (NE), dopamine (DA) and their main metabolites (MHPG, DOPAC) were already significantly reduced in yellow (Ay/a) mice. Reduction of 5-hydroxytryptamine (5-HT) level and an increasing 5-HIAA/5-HT ratio has been observed. When a significant increase in body weight in the yellow (Ay/a) mouse at the age of 12 weeks was present, both NE and DA contents have been increased in the hypothalamus of the obese mouse. MHPG level was lower than in the lean mouse, resulting in an increase of MHPG/NE ratio. The present study suggests that the observed reduction in hypothalamic NE and DA metabolism might be involved in the development of overweight gain in the yellow (Ay/a) mouse.

Molecular nature of mutations induced by irradiation with repeated low doses of X‐rays in spleen, liver, brain and testis oflacZ‐transgenic mice

PURPOSE

To investigate the molecular characteristics of mutations induced by repeated low doses of X-rays in spleen, liver, brain and testis of mice.

MATERIALS AND METHODS

Muta mice, which harbour the lacZ gene contained in the lambda genome, were irradiated with 0.15 Gy every Monday, Wednesday and Friday for 6 months starting at 10 weeks of age for a total of 78 times. Four months after the last irradiation, DNAs were isolated from the four different tissues and the mutant frequencies of lacZ were determined. Next, the nucleotide sequences of the mutant lacZ genes were determined and compared with that of the wild-type to identify the molecular changes in the mutants. The frequencies of different types of mutations were compared with those found in age-matched non-irradiated mice. They were also compared with those found in mice irradiated with a single high dose.

RESULTS

The repeated low-dose irradiation resulted in slight increases in the mutant frequency in the four kinds of tissues. The spleen, liver and brain in repeatedly irradiated mice showed higher frequencies of deletion type mutations than those of non-irradiated mice. In testis, however, the level of the increase was modest and not statistically significant. Complex type mutations were observed only in irradiated tissues. The characteristics observed in somatic tissues were similar to those induced by a single high dose of irradiation.

CONCLUSIONS

The results suggest that the mechanism of mutation induction in vivo is similar between low- and high-dose irradiation in spleen, liver and brain. The low induction of deletion mutations in testis with low-dose irradiation suggests that spermatogonial cells have a unique DNA repair system against low-dose radiation-induced damage.

The oncogenic mutation in the pleckstrin homology domain of AKT1 in endometrial carcinomas

Background:

The phosphatidylinositol 3′-kinase (PI3K)–AKT pathway is activated in many human cancers and plays a key role in cell proliferation and survival. A mutation (E17K) in the pleckstrin homology domain of the AKT1 results in constitutive AKT1 activation by means of localisation to the plasma membrane. The AKT1 (E17K) mutation has been reported in some tumour types (breast, colorectal, ovarian and lung cancers), and it is of interest which tumour types other than those possess the E17K mutation.

Methods:

We analysed the presence of the AKT1 (E17K) mutation in 89 endometrial cancer tissue specimens and in 12 endometrial cancer cell lines by PCR and direct sequencing.

Results:

We detected two AKT1 (E17K) mutations in the tissue samples (2 out of 89) and no mutations in the cell lines. These two AKT1 mutant tumours do not possess any mutations in PIK3CA, PTEN and K-Ras.

Interpretation:

Our results and earlier reports suggest that AKT1 mutations might be mutually exclusive with other PI3K–AKT-activating alterations, although PIK3CA mutations frequently coexist with other alterations (such as HER2, K-Ras and PTEN) in several types of tumours.

Increased insulin demand promotes while pioglitazone prevents pancreatic beta cell apoptosis in Wfs1 knockout mice

AIMS/HYPOTHESIS

The WFS1 gene encodes an endoplasmic reticulum (ER) membrane-embedded protein called Wolfram syndrome 1 protein, homozygous mutations of which cause selective beta cell loss in humans. The function(s) of this protein and the mechanism by which the mutations of this gene cause beta cell death are still not fully understood. We hypothesised that increased insulin demand as a result of obesity/insulin resistance causes ER stress in pancreatic beta cells, thereby promoting beta cell death.

METHODS

We studied the effect of breeding Wfs1 ( -/- ) mice on a C57BL/6J background with mild obesity and insulin resistance, by introducing the agouti lethal yellow mutation (A ( y ) /a). We also treated the mice with pioglitazone.

RESULTS

Wfs1 ( -/- ) mice bred on a C57BL/6J background rarely develop overt diabetes by 24 weeks of age, showing only mild beta cell loss. However, Wfs1 ( -/- ) A ( y ) /a mice developed selective beta cell loss and severe insulin-deficient diabetes as early as 8 weeks. This beta cell loss was due to apoptosis. In Wfs1 ( +/+ ) A ( y ) /a islets, levels of ER chaperone immunoglobulin-binding protein (BiP)/78 kDa glucose-regulated protein (GRP78) and phosphorylation of eukaryotic translation initiation factor 2, subunit alpha (eIF2alpha) apparently increased. Levels of both were further increased in Wfs1 ( -/- ) A ( y ) /a murine islets. Electron micrography revealed markedly dilated ERs in Wfs1 (-/-) A ( y ) /a murine beta cells. Interestingly, pioglitazone treatment protected beta cells from apoptosis and almost completely prevented diabetes development.

CONCLUSIONS/INTERPRETATION

Wfs1-deficient beta cells are susceptible to ER stress. Increased insulin demand prompts apoptosis in such cells in vivo. Pioglitazone, remarkably, suppresses this process and prevents diabetes. As common WFS1 gene variants have recently been shown to confer a risk of type 2 diabetes, our findings may be relevant to the gradual but progressive loss of beta cells in type 2 diabetes.

Breed differentiation among Japanese native chickens by specific skull features determined by direct measurements and computer vision techniques

1. Inter-breed morphological comparisons were made among 11 breeds of Japanese native chickens (Gifujidori, Hinaidori, Shokoku, Totenko, Tomaru, Satsumadori, Shamo, Koshamo, Koeyoshi, Chabo and Nagoya), White Leghorn, broiler chickens (Chunky) and red junglefowl collected in the Philippines, based on results of direct measurements and analysis by computer vision techniques of the skull. 2. Analysis of direct measurements identified two groups of chicken: a small type that included the Chabo, Koshamo, red junglefowl, Gifujidori and Shokoku and a large type that included the remaining breeds studied. These groupings were made based on size determined both in the first (PC1) and second principal component (PC2). The greatest length of the cranium and condylobasal length greatly contributed to the morphological differences between these two groups. 3. Analysis by computer vision techniques, however, identified three groups: the Bantam group (which includes red junglefowl), Shokoku group and Shamo group. White Leghorn clustered within the Shokoku group while the broiler chicken belonged to the Shamo group. The region around the junction of the neural cranium and the visceral cranium contributed greatly to the morphological differences among breeds, both in the PC1 and PC2.

Purification and characterization of a novel esterase (beta-hydroxypalmitate methyl ester hydrolase) and prevention of the expression of virulence by Ralstonia solanacearum

AIMS

To screen novel micro-organisms and enzymes capable of degrading 3-hydroxypalmitic acid methyl ester (3-OH PAME), the quorum-sensing signal molecule (quormone), which regulates the virulence of Ralstonia solanacearum.

METHODS AND RESULTS

Ideonella sp. 0-0013, a betaproteobacterium isolated from soil using the selective-enrichment culture method, was grown on plates containing 3-OH PAME as its main carbon source. beta-Hydroxypalmitate methyl ester hydrolase (betaHPMEH) purified from the supernatant of the Ideonella sp. 0-0013 culture exhibited high hydrolysing activity towards the ester bond of 3-OH PAME and eliminated the 3-OH PAME activity, thereby reducing the virulence of R. solanacearum. An Escherichia coli transformant of the betahpmeh gene expression vector degraded 3-OH PAME, and the crude enzyme from the transformant inhibited in vitro production of the R. solanacearum exopolysaccharide (EPS).

CONCLUSIONS

The ability of betaHPMEH to hydrolyse 3-OH PAME inhibited the production of EPS by the R. solanacearum wild-type strain, indicating that betaHPMEH inhibits the effects of activation of virulence genes. This ability will be potentially useful for pest control of the wilt disease caused by this bacterium.

SIGNIFICANCE AND IMPACT OF THE STUDY

This enzyme is the first protein that has been found to degrade a quormone other than N-acyl homoserine lactone.

Hypermethylation of CpGs in the promoter of the COL1A1 gene in the aged periodontal ligament

Although the human periodontal ligament shows age-associated histological alterations, the molecular mechanisms are not yet understood. We previously found that COL1A1 gene expression declines with age. In this study, we asked whether DNA methylation in the regulatory region of the gene alters in the aging process, as a possible cause of the decline. The method used was a bisulfite modification of cytosine and nucleotide sequencing of DNA. While the 1st intron region was kept demethylated at young and old ages, the levels of methylation at most CpG sites in the proximal and distal regions of the promoter showed elevation at older ages. Analysis of the data indicates the possible importance of DNA hypermethylation in the promoter region for the age-associated decrease of COL1A1 gene expression.

Endoscopic management of pancreaticopleural fistulas: a report of three patients

Pancreaticopleural fistulas are a rare complication of acute or chronic pancreatitis, and are usually treated by surgery. We report three patients whose pancreaticopleural fistulas were successfully treated by endoscopic retrograde cholangiopancreatography and drainage (stenting, nasopancreatic drainage). In one patient a pancreatic pseudocyst persisted despite successful initial closure of the leak using this method and, as it was also suspected to be infected, additional drainage of the pseudocyst was required. Endotherapy of pancreaticopleural fistulas could obviate the need for surgery when conventional medical treatment has failed in this condition.

Secretory IgA, salivary peroxidase, and catalase-mediated microbicidal activity during hydrogen peroxide catabolism in viridans streptococci: pathogen coaggregation

Viridans streptococci can kill methicillin-resistant Staphylococcus aureus (MRSA) through the production of hydrogen peroxide (H2O2). However, several hundred viridans streptococci cells are necessary to kill 1 cfu of MRSA. We analyzed the potency of bactericidal and fungicidal effector molecules induced by catabolism of H2O2 in the oral cavity. Secretory IgA (SIgA) and an unidentified salivary component bound Streptococcus sanguinis, a viridans streprococcus, and MRSA into coaggregates. In these coaggregates, salivary peroxidase and the MRSA catalase produced singlet molecular oxygen (1O2) from H2O2 produced by viridans streptococci. SIgA converted 1O2 into ozone, which has potent bactericidal and fungicidal activity. We calculated that <10 cfu of Streptococcus sanguinis were necessary to kill 1 cfu of MRSA in the coaggregate. SIgA, Aspergillus niger catalase, and H2O2 in saliva killed Candida albicans, which is highly resistant to reagent H2O2. Together with indigenous bacteria and innate immunity, SIgA potentially constitutes a novel system that may sustain oral homeostasis.