cDNA Cloning and Partial Characterization of the DJ-1 Gene from Tribolium castaneum.

The DJ-1 gene is highly conserved across a wide variety of organisms and it plays a role in anti-oxidative stress mechanisms in cells. The red flour beetle, Tribolium castaneum, is widely used as a model insect species because it is easy to evaluate gene function in this species using RNA interference (RNAi). The T. castaneum DJ-1 (TcDJ-1) sequence is annotated in the T. castaneum genome database; however, the function and characteristics of the TcDJ-1 gene have not been elucidated. Here, we investigated the cDNA sequence of TcDJ-1 and partially characterized its function. First, we examined the TcDJ-1 amino acid sequence and found that it was highly conserved with sequences from other species. TcDJ-1 mRNA expression was higher in the early pupal and adult developmental stages. We evaluated oxidant tolerance in TcDJ-1 knockdown adults using paraquat and found that adults with TcDJ-1 knockdown exhibited increased sensitivity to paraquat. Our findings show that TcDJ-1 has an antioxidant function, as observed for DJ-1 from other insects. Therefore, these results suggest that TcDJ-1 protects against oxidative stress during metamorphosis.

De novo transcriptome analysis for examination of the nutrition metabolic system related to the evolutionary process through which stick insects gain the ability of flight (Phasmatodea).

OBJECTIVE: Insects are the most evolutionarily successful groups of organisms, and this success is largely due to their flight ability. Interestingly, some stick insects have lost their flight ability despite having wings. To elucidate the shift from wingless to flying forms during insect evolution, we compared the nutritional metabolism system among flight-winged, flightless-winged, and flightless-wingless stick insect groups. RESULTS: Here, we report RNA sequencing of midgut transcriptome of Entoria okinawaensis, a prominent Japanese flightless-wingless stick insect, and the comparative analysis of its transcriptome in publicly available midgut transcriptomes obtained from seven stick insect species. A gene enrichment analysis for differentially expressed genes, including those obtained from winged vs wingless and flight vs flightless genes comparisons, revealed that carbohydrate metabolic process-related genes were highly expressed in the winged stick insect group. We also found that the expression of the mitochondrial enolase superfamily member 1 transcript was significantly higher in the winged stick insect group than in the wingless stick insect group. Our findings could indicate that carbohydrate metabolic processes are related to the evolutionary process through which stick insects gain the ability of flight.

Apoptosis-mediated vasa down-regulation controls developmental transformation in Japanese Copidosoma floridanum female soldiers.

Copidosoma floridanum is a polyembryonic, caste-forming, wasp species. The ratio of investment in different castes changes with environmental stressors (e.g. multi-parasitism with competitors). The vasa gene was first identified in Drosophila melanogaster as a germ-cell-determining factor, and C. floridanum vasa (Cf-vas) gene positive cells have been known to develop into reproductive larvae. Cf-vas seems to control the ratio of investment in C. floridanum larval castes. In this study, we identified environmental factors that control Cf-vas mRNA expression in Japanese C. floridanum by examining Cf-vas mRNA expression under competitor (Meteorus pulchricornis) venom stress; we treated the male and female morulae with M. pulchricornis venom. We also assessed the effects of multi-parasitism of Japanese C. floridanum with M. pulchricornis and found an increasing number of female soldier larvae. The results showed that several amino acid sequences differ between the Japanese and US Cf-vas. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) showed that Japanese Cf-vas mRNA is expressed in both male and female larvae and pupae, but mRNA expression decreases in adults. Cf-vas mRNA expression significantly decreased, while C. floridanum dronc (Cf-dronc) mRNA expression increased, in female morulae after M. pulchricornis venom treatment at 20 h and 0 h of the culture period, respectively. Females and males showed different Cf-vas or Cf-dronc mRNA expression after M. pulchricornis venom treatment. Therefore, M. pulchricornis venom could affect the ratio of investment in different female castes of Japanese C. floridanum by decreasing Cf-vas mRNA expression via apoptosis.

Incidence of lymph node metastasis in intramucosal gastric cancer measuring 30 mm or less, with ulceration; mixed, predominantly differentiated-type histology; and no lymphovascular invasion: a multicenter retrospective study.

BACKGROUND: Intramucosal gastric cancer, ≤3 cm (≤30 mm) with ulceration, and mixed histology (predominantly differentiated), was previously considered curative after endoscopic resection, and additional surgery was thought to be unnecessary. However, as the evidence base for these criteria remains insufficient, the Japanese Gastric Cancer Treatment Guidelines, ver. 3 (2010) specify that this pathology should be considered noncurative and recommend additional surgery. We report the frequency of lymph node metastasis in patients with these conditions based on a multicenter study. METHODS: Of patients with early gastric cancer who underwent gastrectomy with lymph node dissection, those with a mixed, predominantly differentiated tumor type, ulceration, a tumor diameter ≤3 cm, and no lymphovascular invasion were entered into this study. RESULTS: Four hundred and seven patients met the criteria, 21 of whom were excluded owing to a lack of available information. Thus, a total of 386 patients were included in the analysis, from 37 of the 42 member institutions. The mean study duration was 125 months. The most common combination of mixed histology was tub2 + por (67 %). None of the 386 patients had lymph node metastasis (95 % confidence interval, 0-0.8 %). CONCLUSION: The results of this retrospective study indicate that the risk of lymph node metastasis was less than 1 % among patients with the criteria defined here, considered to be criteria for noncurative resection as per the current guidelines, and suggest that observation alone without additional surgery may result in a good outcome.

[Risk factors for cardiotoxicity during fluorouracil and cisplatin combination chemotherapy].

We investigated the incidence of cardiovascular symptoms in patients treated with fluorouracil and cisplatin (FP) combination chemotherapy. Between April 2010 and March 2011, 61 patients were treated with FP therapy at the Department of Gastroenterology, Niigata Prefectural Cancer Center Hospital. Within 1 week of treatment and within the first or second course of therapy, six patients developed chest pain. To investigate the risk factors for cardiotoxicity following FP therapy, patients were divided into cardiotoxicity incidence and non-incidence groups. The prevalence of diabetes, hypertension, and heart disease was not significantly different between the two groups. Furthermore, serum sodium and potassium levels were not altered following FP therapy. Therefore, no definitive risk factors for cardiotoxicity were identified. These results suggest that while FP chemotherapy-induced nausea, vomiting, and renal damage are serious adverse effects, further attention should also be paid to the potential cardiotoxic effects of FP therapy.

Blockade of CXCL10 protects mice from acute colitis and enhances crypt cell survival.

Crypt cell renewal is essential for normal intestinal homeostasis as well as mucosal regeneration following injury. However, the factors regulating crypt cell growth in pathological conditions are not fully understood. We report here that the endogenously produced chemokine CXCL10 regulates crypt cell proliferation. CXCL10 was constitutively expressed by basal crypts in mouse colon, but the expression of CXCL10 as well as CXCR3 was enhanced in the epithelium in the proliferative zone after oral administration of dextran sulfate sodium. Neutralization of CXCL10 protected mice from epithelial ulceration by promoting crypt cell survival without evidence of altered immune cell infiltration. Furthermore, recombinant CXCL10 administration into mice inhibited intestinal epithelial cell proliferation. These findings suggest that CXCL10 regulates crypt cell growth to maintain intestinal homeostasis in an autocrine or paracrine fashion. Thus, CXCL10 can be a new therapeutic target for inflammatory bowel disease by controlling the dynamics of epithelial homeostasis.