Involvement of the Arg566 residue of Aeromonas sobria serine protease in substrate specificity

Aeromonas sobria serine protease (ASP) is an extracellular serine protease secreted by the organism. Here, we identified the amino acid residue of ASP that contributes to substrate specificity by using both synthetic peptides and biological protein components. The results showed that the arginine residue at position 566 (Arg-566) of ASP, which is located in the extra occluding region of ASP close to an entrance of the catalytic cavity, is involved in the substrate specificity. A substitutional point mutation of the Arg-566 residue of ASP to Ala residue (ASP[R566A]) caused a decrease of the proteolytic efficiency for a certain substrate. In addition, ASP lost the ability to recognize the primary substrate by such a point mutation, and ASP[R566A] reacted to a wide range of synthetic substrates. It is likely that Arg-566 causes an interaction with the amino acid residue at position P3 of the substrate, which is the third amino acid residue upstream from the cleavage site. Another study using ORF2 protein, a chaperone protein of ASP, further suggested that Arg-566 could also play an important role in interaction with ORF2. We therefore conclude that the Arg-566 residue of ASP is likely responsible for the selection of substrates.

Photoluminescence from vibrational excited-states for organic molecules adsorbed on Si nanoparticles

Herein, Si nanoparticles have been fabricated from Si swarf using a bead milling method. The adsorption of 9,10-dimethylanthracene (DMA) on Si nanoparticles enhances the photoluminescence (PL) intensity by ∼60 000 times that of DMA in hexane. The PL spectra possess peaked structures due to the vibronic transition of DMA. For the excitation energies higher than 4.0 eV, vibronic bands with energies higher than the (0, 0) band were observed and attributed to PL from the vibrational excited-states. The excitation spectra showed that incident light was absorbed by both DMA and the Si nanoparticles. The lifetime of the photo-generated electron-hole pairs in the Si nanoparticles was much longer than the DMA PL lifetime; this indicated that either a hole or an electron transferred to DMA first, followed by an opposite charge transfer. In the cases where a hole is first transferred to DMA, an electronic ground-state is stabilized via solvation. When an electron is captured by the potential of the electronic excited-state, transitions from the vibrational excited-states proceed due to the high transition probability, generating PL bands with energies higher than the (0, 0) band. In the cases where an electron is first transferred to DMA, internal relaxation to the vibrational ground-state occurs, and the potential of the electronic excited-state is lowered via solvation.

The influence of CYP2C19 polymorphisms on exacerbating effect of rabeprazole in celecoxib-induced small bowel injury

BACKGROUND

Simultaneous use of proton pump inhibitors (PPIs) has been shown to increase the risk of nonsteroidal anti-inflammatory drug (NSAID)-induced small bowel injury.

AIM

To investigate whether polymorphisms of the cytochrome P450 2C19 gene (CYP2C19), encoding a key metabolising enzyme for PPIs, are associated with small bowel injury induced by celecoxib in combination with the PPI rabeprazole.

METHODS

Study participants included 55 healthy Japanese volunteers, who participated in the PPI-NSAID Kyushu University Study using video capsule endoscopy. For 2 weeks, 26 subjects were treated with celecoxib plus rabeprazole (rabeprazole group), and 29 subjects received celecoxib plus placebo (placebo group). All subjects were genotyped for CYP2C19 using real-time fluorescent polymerase chain reaction. Subjects were sub-classified as poor metabolizers or extensive metabolizers. The incidence and number of small bowel injuries were compared between poor metabolizers and extensive metabolizers in each group.

RESULTS

In the rabeprazole group, the incidence of small bowel injuries was significantly higher in poor metabolizers than in extensive metabolizers (85.7% vs 31.6%, P=.026). The number of mucosal injuries in the rabeprazole group was also significantly higher in poor metabolizers compared with extensive metabolizers (median [range] 3 [0-31] vs 0 [0-7], P=.01). In addition, we found a significant interaction between CYP2C19 genotype and concomitant use of rabeprazole in subjects at risk for celecoxib-induced small bowel injury.

CONCLUSIONS

The CYP2C19 genotype might be associated with the risk of small bowel injury when celecoxib is combined with rabeprazole.

Association of NOD2 Mutations with Aggressive Periodontitis

Aggressive periodontitis (AgP) is characterized by rapid alveolar bone destruction and tooth loss early in life, and its etiology remains unclear. To explore the genetic risk factors of AgP, we performed genome-wide single-nucleotide polymorphism genotyping for identity-by-descent mapping and identified 32 distinct candidate loci, followed by whole exome sequencing with 2 pedigrees of AgP consisting of 3 cases and 1 control in 1 family and 2 sibling cases in the other. After variant filtering procedures and validation by targeted Sanger sequencing, we identified 2 missense mutations at 16q12 in NOD2 (p.Ala110Thr and p.Arg311Trp), which encodes nucleotide-binding oligomerization domain protein 2. We further examined 94 genetically unrelated AgP patients by targeted sequencing of NOD2 and found that 2 patients among them also carried the p.Arg311Trp variant. Furthermore, we found 3 additional missense mutations in this gene (p.His370Tyr, p.Arg459Cys, and p.Ala868Thr). These mutations either had not been previously observed or are extremely rare (frequency <0.001) in Asian populations. NOD2 plays a crucial role in innate immunity as an intracellular receptor initiating nuclear factor κB-dependent and mitogen-activated protein kinase-dependent gene transcription. These results demonstrated NOD2 as a novel gene involved in AgP.

Lip b 1 is a novel allergenic protein isolated from the booklouse, Liposcelis bostrychophila

BACKGROUND

Booklice, belonging to the order Psocoptera, are small household insect pests that are distributed worldwide. Liposcelis bostrychophila, a common home-inhabiting species of booklouse, infests old books, sheets of paper, and stored food. Recent entomological and serological studies demonstrated that L. bostrychophila accounted for the majority of detectable insects in house dust and could be a potent inducer of respiratory allergy. Our recent proteomic analysis identified a potent allergenic protein from L. bostrychophila, designated Lip b 1, and determined its partial amino acid sequences.

METHODS

Cloning of cDNAs for Lip b 1 was performed by large-scale transcriptome analysis (RNA-seq) and subsequent reverse transcription polymerase chain reaction. The full-length amino acid sequences deduced from Lip b 1 cDNAs were bioinformatically analyzed. The recombinant proteins of glutathione S-transferase (GST)-fused Lip b 1 were analyzed by Western blot and enzyme-linked immunosorbent assay.

RESULTS

Lip b 1 cDNAs encoding two types of 254-amino acid proteins were cloned. The clones shared 87% identity, and the deduced molecular weights and isoelectric points were consistent with those determined in our previous study. The two types of Lip b 1 proteins in the GST-fused form were similarly reactive with sera from allergic patients sensitized with L. bostrychophila.

CONCLUSIONS

Lip b 1 is a novel protein possibly causing booklouse allergy.

Influence of coronal bowing on the lower alignment and the positioning of component in navigation and conventional total knee arthroplasty

BACKGROUND

Coronal alignment is an important factor for the function and longevity of total knee arthroplasty (TKA). Coronal bowing of the lower extremity is common among Asians and it may pose a risk for malalignment of the lower leg and malposition of component.

HYPOTHESIS

We hypothesized that coronal bowing itself has a risk for malalignment of the lower leg and malposition of femoral/tibial components and that navigation TKA is beneficial for patients with coronal bowing. We investigated the incidence of femoral/tibial bowing in patients treated with TKA and compared the radiographic parameters between the navigation group and the conventional group. Additionally, the influence of coronal bowing on these radiographic parameters was investigated.

MATERIALS AND METHODS

We enrolled 35 patients with knee osteoarthritis and 70 bilateral simultaneous TKAs. The patients underwent TKA with the use of a computer tomography-free navigation in one knee and conventional TKA in the contralateral knee. Preoperative coronal bowing were measured, and the subjects were divided into 2 subgroups, i.e. the bowing group and the non-bowing group. Lateral bowing was expressed as plus (+) and medial bowing was expressed as minus (-). Various radiographic parameters, including coronal bowing, lower leg alignment, component position, and outliers were compared between the navigation group and the conventional group.

RESULTS

Femoral bowing varied from -7.4° to 10.9° with an average of 3.0°. Tibial bowing varied from -4.1° to 4.6° with an average of 0.4°. The femoral component was placed more properly in the navigation group. Number of outlier regarding to the coronal femoral component angle to the femoral mechanical axis was 14 cases (37.8%) in the bowing group and 6 cases (18.2%) in the non-bowing group (P=0.04).

DISCUSSION

In conclusion, coronal femoral bowing has an important effect on femoral bone cut in TKA. The navigated TKA was more consistent than conventional TKA in aiding proper alignments of femoral component.

LEVEL OF EVIDENCE

Level II, comparative prospective study.

Assessing the progression of chronic periodontitis using subgingival pathogen levels: a 24-month prospective multicenter cohort study

BACKGROUND

The diagnosis of the progression of periodontitis presently depends on the use of clinical symptoms (such as attachment loss) and radiographic imaging. The aim of the multicenter study described here was to evaluate the diagnostic use of the bacterial content of subgingival plaque recovered from the deepest pockets in assessing disease progression in chronic periodontitis patients.

METHODS

This study consisted of a 24-month investigation of a total of 163 patients with chronic periodontitis who received trimonthly follow-up care. Subgingival plaque from the deepest pockets was recovered and assessed for bacterial content of Porphyromonas gingivalis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans using the modified Invader PLUS assay. The corresponding serum IgG titers were measured using ELISA. Changes in clinical parameters were evaluated over the course of 24 months. The sensitivity, specificity, and prediction values were calculated and used to determine cutoff points for prediction of the progression of chronic periodontitis.

RESULTS

Of the 124 individuals who completed the 24-month monitoring phase, 62 exhibited progression of periodontitis, whereas 62 demonstrated stable disease. The P. gingivalis counts of subgingival plaque from the deepest pockets was significantly associated with the progression of periodontitis (p < 0.001, positive predictive value = 0.708).

CONCLUSIONS

The P. gingivalis counts of subgingival plaque from the deepest pockets may be associated with the progression of periodontitis.

Loss of p53 induces leukemic transformation in a murine model of Jak2 V617F-driven polycythemia vera

As leukemic transformation of myeloproliferative neoplasms (MPNs) worsens the clinical outcome, reducing the inherent risk of the critical event in MPN cases could be beneficial. Among genetic alterations concerning the transformation, the frequent one is TP53 mutation. Here we show that retroviral overexpression of Jak2 V617F mutant into wild-type p53 murine bone marrow cells induced polycythemia vera (PV) in the recipient mice, whereas Jak2 V617F-transduced p53-null mice developed lethal leukemia after the preceding PV phase. The leukemic mice had severe anemia, hepatosplenomegaly, pulmonary hemorrhage and expansion of dysplastic erythroid progenitors. Primitive leukemia cells (c-kit⁺Sca1⁺Lin^- (KSL) and CD34^-CD16/32^-c-kit⁺Sca1^-Lin^- (megakaryocyte-erythroid progenitor; MEP)) and erythroid progenitors (CD71⁺) from Jak2 V617F-transduced p53-null leukemic mice had leukemia-initiating capacity, however, myeloid differentiated populations (Mac-1⁺) could not recapitulate the disease. Interestingly, recipients transplanted with CD71⁺ cells rapidly developed erythroid leukemia, which was in sharp contrast to leukemic KSL cells to cause lethal leukemia after the polycythemic state. The leukemic CD71⁺ cells were more sensitive to INCB18424, a potent JAK inhibitor, than KSL cells. p53 restoration could ameliorate Jak2 V617F-transduced p53-null erythroleukemia. Taken together, our results show that p53 loss is sufficient for inducing leukemic transformation in Jak2 V617F-positive MPN.

Development of an in vitro immunobiotic evaluation system against rotavirus infection in bovine intestinal epitheliocytes

The bovine intestinal epithelial cell line (BIE cells) expresses the Toll-like receptor (TLR)3 and is able to mount an antiviral immune response after the stimulation with poly(I:C). In the present study, we aimed to further characterise the antiviral defence mechanisms in BIE cells by evaluating the innate immune response triggered by rotavirus (RV) infection. In addition, we attempted to determine whether immunobiotic bifidobacteria are able to confer protection of BIE cells against RV infection by beneficially modulating the antiviral immune response. RV OSU (porcine) and UK (bovine) effectively infected BIE cells, while a significant lower capacity to infect BIE cells was observed for human (Wa) and murine (EW) RV. We observed that viral infection in BIE cells triggered TLR3/RIG-I-mediated immune responses with activation of IRF3 and TRAF3, induction of interferon beta (IFN-β) and up-regulation of inflammatory cytokines. Our results also demonstrated that preventive treatments with Bifidobacterium infantis MCC12 or Bifidobacterium breve MCC1274 significantly reduced RV titres in infected BIE cells and differentially modulated the innate immune response. Of note, both strains significantly improved the production of the antiviral factor IFN-β in RV-infected BIE cells. In conclusion, this work provides comprehensive information on the antiviral immune response of BIE cells against RV, that can be further studied for the development of strategies aimed to improve antiviral defences in bovine intestinal epithelial cells. Our results also demonstrate that BIE cells could be used as a newly immunobiotic evaluation system against RV infection for application in the bovine host.

Effects of Aerobic and Resistance Training Combined with Fortified Milk on Muscle Mass, Muscle Strength, and Physical Performance in Older Adults: A Randomized Controlled Trial

OBJECTIVES

Fortified milk and resistance training (RT) increase muscle mass, muscle strength, and physical performance in older adults, but it remains unclear whether RT combined with aerobic training (AT) would have stronger effects on these outcomes. The purpose of this study was to examine the effects of aerobic and resistance training (ART) combined with fortified milk consumption on muscle mass, muscle strength, and physical performance in older adults.

DESIGN

Open-labeled randomized controlled trial.

SETTING

University of Tsukuba.

PARTICIPANTS

Fifty-six older adults aged 65-79.

INTERVENTION

Participants were randomly allocated into resistance training (RT + fortified milk, n = 28) and aerobic and resistance training (ART + fortified milk, n = 28) groups. All participants attended supervised exercise programs twice a week at University of Tsukuba and ingested fortified milk every day for 12 weeks. Skeletal muscle index ([SMI]: appendicular lean mass/height2) was assessed using dual-energy X-ray absorptiometry as a muscle mass measure. One-repetition maximum strength was measured using four kinds of resistance training machines (chest press, leg extension, leg curl, and leg press) as muscle strength measures. Sit-to-stand and arm curl tests were also assessed as physical performance measures.

MEASUREMENTS

The primary measurements were muscle mass and strength. The secondary outcomes were physical performance, blood samples, habitual diet, habitual physical activity, and medication use.

RESULTS

Although the muscle strength and physical performance measures significantly improved in both groups, SMI significantly improved in only the RT group. There was no significant difference in the change in SMI and muscle strength measures between the two groups. However, the change in sit-to-stand and arm curl measures in the ART group were significantly higher than those in the RT group.

CONCLUSIONS

These results suggest that AT before RT combined with fortified milk consumption has similar effects on skeletal muscle mass and strength compared with RT alone, but it may be a more useful strategy to improve physical performance in older adults. Although the mechanism of our intervention is uncertain, our program would be an effective prevention for sarcopenia in older adults.

Proliferative Enteropathy caused by Lawsonia intracellularis in Chickens

Proliferative enteropathy (PE) is an infectious disease caused by Lawsonia intracellularis (Li), an obligate intracellular bacterium. PE is endemic in swine herds and has been reported in a variety of mammals including horses, hamsters, rabbits, rats, guinea pigs, ferrets, foxes, dogs, sheep, deer and non-human primates. Avian cases are reported only in ratite birds, including emus and ostriches. Some studies show an absence of Lawsonia spp. infection in chickens. In this study, we performed morphological and bacteriological examinations on the intestines of two broiler chickens that had been condemned at a poultry slaughter plant in Japan due to intestinal haemorrhage, which was a result of focal coccidial enteritis. Histopathology revealed proliferation of the villous epithelium in the small and/or large intestines, especially the caeca, regardless of coccidial lesions. Warthin-Starry silver staining and immunohistochemistry using anti-Li monoclonal antibody revealed numerous bacteria and/or antigens in the villous epithelium. Scanning electron microscopy and transmission electron microscopy revealed the presence of curved rods, morphologically compatible with Li, in the apical cytoplasm of the epithelium. Polymerase chain reaction products specific for Li were amplified from DNA samples extracted from formalin-fixed and paraffin wax-embedded tissue. These results suggest that Li can cause PE, characterized by proliferation of the villous epithelium, in chickens.

The Human KROX-26/ZNF22 Gene is Expressed at Sites of Tooth Formation and Maps to the Locus for Permanent Tooth Agenesis (He-Zhao Deficiency)

Tooth development is mediated by sequential and reciprocal interactions between dental epithelium and mesenchyme under the molecular control of secreted growth factors and responsive transcription factors. We have previously identified the transcription factor Krox-26 as a potential regulator of tooth formation in mice. The purpose of this study was to investigate a potentially similar role for the human KROX-26 orthologue. We cloned the KROX-26 gene and found its single mRNA transcript (2.4 kb) to be expressed in multiple adult tissues. During fetal development, KROX-26 is expressed in the epithelial component of the developing tooth organ during early bud and cap stages as well as in osteoblasts of craniofacial bone and the developing tongue. The KROX-26 gene was mapped to chromosome 10q11.21, a locus that has been associated with permanent tooth agenesis (He-Zhao deficiency). These results indicate a potential function for KROX-26 in the molecular regulation of tooth formation in humans.

Modulation of porcine intestinal epitheliocytes immunetranscriptome response by Lactobacillus jensenii TL2937

In order to evaluate probiotic strains applicable for the beneficial immunomodulation of the porcine gut (immunobiotics), we previously developed a porcine intestinal epitheliocyte cell line (PIE cells). Here, transcriptomic studies using PIE cells were performed considering that this information would be valuable for understanding the mechanisms involved in the protective activity of the immunobiotic strain Lactobacillus jensenii TL2937 against intestinal inflammatory damage in pigs. In addition, those studies would provide criteria for selecting biomarkers for the screening of new immunobiotic strains. We performed microarray analysis to investigate the transcriptomic response of PIE cells to the challenge with heat-stable enterotoxigenic Escherichia coli (ETEC) pathogen-associated molecular patterns (PAMPs) and, the changes induced by L. jensenii TL2937 in that response. The approach allowed us to obtain a global overview of the immune genes involved in the response of PIE cells to heat-stable ETEC PAMPs. We observed that L. jensenii TL2937 differently modulated gene expression in ETEC PAMPs-challenged PIE cells. Microarray and RT-PCR analysis indicated that the most remarkable changes in PIE cells transcriptomic profile after heat-stable ETEC PAMPs challenge were observed in chemokines, adhesion molecules, complement and coagulation cascades factors. In addition, an anti-inflammatory effect triggered by TL2937 strain in PIE cells was clearly demonstrated. The decrease in the expression of chemokines (CCL8, CXCL5, CXCL9, CXCL10, and CXCL11), complement (C1R, C1S, C3, and CFB), and coagulation factors (F3) by L. jensenii TL2937 supports our previous reports on the immunoregulatory effect of this strain. These results provided clues for the better understanding of the mechanism underlying host-immunobiotic interaction in the porcine host. The comprehensive transcriptomic profiles of PIE cells provided by our analyses successfully identified a group of genes, which could be used as prospective biomarkers for the screening and evaluation of new anti-inflammatory immunobiotics for the prevention of inflammatory intestinal disorders in pigs.

Heat stress-induced phosphorylation of FoxO3a signalling in rat skeletal muscle

AIM

A recent study demonstrated that FoxO3a was directly induced by the overexpression of Hsp72 in rat soleus muscle. However, whether heat stress treatment induces FoxO3a phosphorylation in rat skeletal muscle remains unclear. This study examined the effects of heat stress on the regulation of the FoxO3a signalling pathway in rat skeletal muscle.

METHODS

Thirty-two male Wistar rats (15 weeks old) were randomly assigned into two groups; sedentary control group (Sed, n = 8) and experimental group (n = 24). After an overnight fast, one leg of each rat (HS leg) in the experimental group was immersed in hot water (43 °C) for 30 min, and the soleus and plantaris muscles in both legs were removed immediately (0 min), 30 min, 60 min, or 24 h after the heat stress (n = 6 each group). The contralateral, non-heated leg in the experimental group served as an internal control (CT leg).

RESULTS

Heat stress treatment resulted in a significant increase in FoxO3a phosphorylation (Ser253) in the soleus and plantaris muscles of heat-stressed legs after 24 h. Hsp72 expression in heat-stressed legs was significantly higher at 60 min and 24 h in these muscles. Activation of the PTEN/Akt and MEK/ERK pathways was also observed in these muscles immediately after stress, but not at 24 h. There were no differences in FoxO1 and AMPKα phosphorylation in either muscle.

CONCLUSION

Heat stress in rat skeletal muscle induces phosphorylation of FoxO3a signalling, and it may be related to Hsp72 upregulation, and the activation of the PTEN/Akt and MEK/ERK pathways.