Pigment-dispersing factor affects nocturnal activity rhythms, photic entrainment, and the free-running period of the circadian clock in the cricket gryllus bimaculatus

Pigment-dispersing factor (PDF) is a neuropeptide widely distributed in insect brains and plays important roles in the circadian system. In this study, we used RNA interference to study the role of the pigment-dispersing factor (pdf) gene in regulating circadian locomotor rhythms in the cricket, Gryllus bimaculatus. Injections of pdf double-stranded RNA (dspdf) effectively knocked down the pdf mRNA and PDF peptide levels. The treated crickets maintained the rhythm both under light-dark cycles (LD) and constant darkness (DD). However, they showed rhythms with reduced nocturnal activity with prominent peaks at lights-on and lights-off. Entrainability of dspdf-injected crickets was higher than control crickets as they required fewer cycles to resynchronize to the LD cycles shifted by 6 h. The free-running periods of the dspdf-injected crickets were shorter than those of control crickets in DD. These results suggest that PDF is not essential for the rhythm generation but involved in control of the nocturnality, photic entrainment, and fine tuning of the free-running period of the circadian clock.     

Gingipains inactivate a cell surface ligand on Porphyromonas gingivalis that induces TLR2-and TLR4-independent signaling

Arginine-specific gingipain and lysine-specific gingipain are two major cysteine proteinases produced by Porphyromonas gingivalis. To clarify the role of gingipains in the interaction between P. gingivalis and the innate immune system, CHO reporter cells expressing TLR2 or TLR4 were stimulated with wildtype or gingipain-deficient P. gingivalis cells and activation of nuclear factor-kappaB in these cells was examined. While CHO/CD14 cells and 7.19 cells, an MD-2-defective mutant derived from CHO/CD14 cells, failed to respond to wild-type P. gingivalis, they responded to gingipain-deficient P. gingivalis. On the other hand, CHO/CD14/TLR2 cells responded to both wild-type and gingipain-deficient P. gingivalis. These results suggested that gingipains have no effects on TLR2-dependent signaling from P. gingivalis but have inhibitory effects on TLR2-and TLR4-independent signaling in CHO cells. Indeed, the activity of gingipain-deficient P. gingivalis to induce the activation of 7.19 cells was diminished after treatment of the bacterial cells with gingipains. We next partially purified bacterial cell components activating 7.19 cells from gingipain-deficient P. gingivalis. The activity of the partially purified components was diminished by treatment with heat or gingipains. It is also noteworthy that anti-CD14 mAb inhibited the activation of 7.19 cells induced by the partially purified components. These results indicated that the components of P. gingivalis that were able to induce TLR2-and TLR4-independent signaling were inactivated by gingipains before being recognized by CD14. The inactivation of the components would be helpful for P. gingivalis to escape from the innate immune system.     

Association of mast cells with Warthin's tumor in fine needle aspirates of the salivary gland

OBJECTIVE: To determine the significance of the presence of mast cells in Warthin's tumor by evaluating the occurrence of these cells in cellular and immunohistochemical preparations. STUDY DESIGN: Specimens derived from five cases of FNAC were examined. A total of four slides from five cases were prepared from each: two air-dried smears were stained with May-Grünwald-Giemsa (MGG) stain and two with Hansel's stain. The other two were alcohol fixed and stained using the Papanicolaou method. The smears were evaluated for the presence of mast cells, especially associated with oxyphilic cells. In order to investigate the location of mast cells, we also counted those cells by means of immunohistochemistry using anti-mast cell monoclonal antibody AA1. RESULTS: The Hanselstained cellular sample from Warthin's tumor contained numerous mast cells, associated mainly with large, oxyphilic cell sheets. The number of AA1-positive cells (mast cells) stained with immunohistochemistry was greater in epithelial component than in lymphoid stroma. CONCLUSION: Mast cells in a salivary gland aspirate might be indicative of Warthin's tumor; therefore, MGG-stained slides offer the advantage of ease of preparation, particularly when the typical cytologic features are not present.     

Hormonal regulation of fruit set, parthenogenesis induction and fruit expansion in Japanese pear

The effects of applied gibberellins (GAs), GA₁, GA₃, GA₄ and GA₇ with a cytokinin, N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) and indole-3-acetic acid (IAA) on fruit set, parthenogenesis induction and fruit expansion of a number of Rosaceae species were assessed. These included Japanese pear cv. ‘Akibae’ (self-compatible) and cv. ‘Iwate yamanashi’ (a seedless cultivar). Other Rosaceae species (Pyrus communis, Chaenomeles sinensis, Cydonia oblonga, and Malus pumila) were also investigated. GA₄, GA₇ and CPPU are very effective in inducing parthenocarpic fruit growth, whereas GA₁, GA₃ and IAA, have no ability to induce parthenogenesis in Japanese pear. GA₄- and GA₇-induced parthenocarpic fruit tended to be smaller in size, higher in flesh hardness, and showed advanced fruit ripening in comparison to pollinated fruit and to parthenocarpic fruit induced by CPPU. GA₄- and GA₇-induced parthenocarpic fruit also had an increased pedicel length and fruit shape index and also showed a slight protrusion of the calyx end. CPPU, GA₄ and GA₇ alone or combination with uniconazole were also active in inducing parthenogenesis in three other Rosaceae species, although final fruit set was extremely low. GA₁ was essentially inactive in promoting fruit expansion unlike the other bioactive GAs, whose effectiveness in promoting fruit cell expansion was as follow: GA₄ ≈ GA₇ > GA₃ > GA₁.     

Enhanced plasma ghrelin levels in rats with streptozotocin-induced diabetes

Human saliva, which contains nitrite, is normally mixed with gastric juice, which contains ascorbic acid (AA). When saliva was mixed with an acidic buffer in the presence of 0.1 mM AA, rapid nitric oxide formation and oxygen uptake were observed. The oxygen uptake was due to the oxidation of nitric oxide, which was formed by AA-dependent reduction of nitrite under acidic conditions, by molecular oxygen. A salivary component SCN⁻ enhanced the nitric oxide formation and oxygen uptake by the AA/nitrite system. The oxygen uptake by the AA/nitrite/SCN⁻ system was also observed in an acidic buffer solution. These results suggest that oxygen is normally taken up in the stomach when saliva and gastric juice are mixed.     

Novel mutations of CDKN1C in Japanese patients with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is an imprinting-related human disease that is characterized by macrosomia, macroglossia, abdominal wall defects, and variable minor features. BWS is caused by several genetic/epigenetic alterations, such as loss of methylation at KvDMR1, gain of methylation at H19-DMR, paternal uniparental disomy of chromosome 11, CDKN1C mutations, and structural abnormalities of chromosome 11. CDKN1C is an imprinted gene with maternal preferential expression, encoding for a cyclin-dependent kinase (CDK) inhibitor. Mutations in CDKN1C are found in 40 % of familial BWS cases with dominant maternal transmission and in ~5 % of sporadic cases. In this study, we searched for CDKN1C mutations in 37 BWS cases that had no evidence for other alterations. We found five mutations—four novel and one known—from a total of six patients. Four were maternally inherited and one was a de novo mutation. Two frame-shift mutations and one nonsense mutation abolished the QT domain, containing a PCNA-binding domain and a nuclear localization signal. Two missense mutations occurred in the CDK inhibitory domain, diminishing its inhibitory function. The above-mentioned mutations were predicted by in silico analysis to lead to loss of function; therefore, we strongly suspect that such anomalies are causative in the etiology of BWS.     

EML4 promotes the loading of NUDC to the spindle for mitotic progression

Echinoderm microtubule-associated protein (EMAP)-like (EML) family proteins are microtubule-associated proteins that have a conserved hydrophobic EMAP-like protein (HELP) domain and multiple WD40 domains. In this study, we examined the role of EML4, which is a member of the EML family, in cell division. Time-lapse microscopy analysis demonstrated that EML4 depletion induced chromosome misalignment during metaphase and delayed anaphase initiation. Further analysis by immunofluorescence showed that EML4 was required for the organization of the mitotic spindle and for the proper attachment of kinetochores to microtubules. We searched for EML4-associating proteins by mass spectrometry analysis and found that the nuclear distribution gene C (NUDC) protein, which is a critical factor for the progression of mitosis, was associated with EML4. This interaction was mediated by the WD40 repeat of EML4 and by the C-terminus of NUDC. In the absence of EML4, NUDC was no longer able to localize to the mitotic spindle, whereas NUDC was dispensable for EML4 localization. Our results show that EML4 is critical for the loading of NUDC onto the mitotic spindle for mitotic progression.     

Water-soluble ferulic acid derivatives improve amyloid-β-induced neuronal cell death and dysmnesia through inhibition of amyloid-β aggregation

Ferulic acid (FA) has been reported to exhibit protective effects against amyloid-β (Aβ)-induced neurodegeneration in vitro and in vivo. Recently, we developed two water-soluble FA derivatives: 1-feruloyl glycerol and 1-feruloyl diglycerol. In this study, we examined the neuroprotective effects of these water-soluble FA derivatives on Aβ-induced neurodegeneration both in vitro and in vivo. FA and water-soluble FA derivatives inhibited Aβ aggregation and destabilized pre-aggregated Aβ to a similar extent. Furthermore, water-soluble FA derivatives, as well as FA, inhibited Aβ-induced neuronal cell death in cultured neuronal cells. In in vivo experiments, oral administration of water-soluble FA derivatives to mice improved Aβ-induced dysmnesia assessed by contextual fear conditioning test and protected hippocampal neurons against Aβ-induced neurotoxicity. This study provides useful evidence suggesting that water-soluble FA derivatives are expected to be effective neuroprotective agents.