The increase of amino acids induces the expression of vitellogenin after spinning in the silkworm Bombyx mori.

Silkworms are economically important insects because of the value of their silk. After finishing silk spinning, silkworms begin another important physiological process, vitellogenesis. In this study, we explored the relationship between silk spinning and vitellogenin (BmVg) expression in silkworms. In silkworms with the silk fibroin heavy chain gene knocked-out, the concentration of amino acids in the hemolymph was found to be significantly higher than that in the wild type, and the expression of BmVg was advanced at day 7 of the fifth instar stage and 0 h after spinning. Furthermore, through culturing fat body in vitro with different substances treatment including glucose, trehalose, amino acids, 20-hydroxyecdysone, and insulin, we found that only amino acids could induce BmVg expression. RNA interference of BmTOR1 in female silkworms could down-regulate BmVg transcription, resulting in shortened egg ducts and smaller eggs relative to the control. Therefore, these results showed that amino acids could induce BmVg expression through the TOR signaling pathway. Fat body cultured with amino acids in vitro and experiments involving amino acids injected into the silkworm showed that the majority of main amino acids of silk protein could induce BmVg expression. These results suggested that BmVg expression is related to silk spinning and this study would lay a foundation for elucidating the stage specificity expression of BmVg.

A novel GATA transcription factor GATAß4 promotes vitellogenin transcription and egg formation in the silkworm Bombyx mori.

GATA transcription factors (GATAs) are widely expressed among various organisms and belong to the zinc finger protein family. GATA transcription factors play important roles in the proliferation, differentiation, and development of eukaryotes. Previous studies have shown that GATA participates in oogenesis by selective splicing in silkworms. In this study, we investigated the function of GATAs during vitellogenesis using female silkworms (Bombyx mori). Six types of GATA transcription factors were successfully cloned in the fat body of silkworms during the wandering stage and only BmGATAß4 induced the activity of the Bombyx mori vitellogenin (BmVg) promoter. Furthermore, BmVg and BmGATAß4 exhibited similar expression patterns in the fat body of female silkworms during the wandering stage. Electrophoretic mobility shift assays, cell transfection assays, and chromatin immunoprecipitation showed that BmGATAß4 was involved in regulating the transcription of BmVg by directly binding to the GATA cis-response element 1 (CRE1) and GATA cis-response element 2 (CRE2) in the promoter of the BmVg gene. RNA interference of BmGATAß4 in female silkworms downregulated BmVg transcription, resulting in a decrease in egg size and shortening of the length of egg tubes relative to the control. In summary, our results indicated that BmGATAß4 bound to the GATA CRE1 and CRE2 motifs in the BmVg promoter to upregulate BmVg expression in the fat body of female silkworms.

[Establishment of a suitable control reporter plasmid of a dual luciferase reporter gene system for hormone research in silkworm cell lines].

The dual luciferase reporter gene system provides sensitive readout, while it relies on a constitutively-expressed control gene for readout normalization. However, most standard control reporter genes are not constitutively expressed under all conditions. Here, we report an effective method to construct a control reporter plasmid for the dual luciferase reporter gene system that would be suitable for hormone research in silkworm cell lines. First, we modified BmVgP78M, a stably-expressed constitutive promoter in silkworm cells by mutating its hormone-related element. Then, we constructed the pRL-VgP78M control reporter plasmid by replacing the SV40 promoter and chimeric intron sequences in pRL-SV40 with the BmVgP78M sequence. Finally, we confirmed that the pRL-VgP78M control reporter plasmid could be stably expressed in silkworm cell lines via cell transfection experiments, and it was unresponsive to the induction of ecdysone, juvenile hormone, or their transcription factors. We thus obtained a control reporter plasmid pRL-VgP78M that could be expressed stably and moderately in silkworm cells. It can be readily used as the control reporter plasmid of the dual luciferase reporter gene system for hormone research in silkworm cell lines. It will also provide a reference for construction of control reporter plasmids of dual luciferase reporter gene systems that are adaptable to cell lines isolated from other species.

Pigmentary analysis of eggs of the silkworm Bombyx mori.

Ommochromes are major pigments involved in coloration of eggs, eyes, wings, and epidermis of insects. Bombyx mori (silkworm) eggs contain a mixture of ommochrome pigments and their precursors. Here, we analyzed the pigment composition of every egg color strain using egg color mutants (w-2, pe, and re) and wild-type strains (dazao and C108) by using full wavelength scanning and high-performance liquid chromatography. We identified ommochrome pigments and their precursors in pigment extracts from non-diapause eggs and diapause eggs, and found that the quantities of ommochrome precursor 3-hydroxy-kynurenine were much higher in the diapause eggs. Ommochrome pigments were absent in the non-diapause eggs. We analyzed the pigment composition of every egg color strain and found an accumulation of 3-hydroxy-kynurenine and absence of ommochromes in the yellow eggs (w-2 and pe), suggesting that the essential factors for ommochrome biosynthesis are high levels of 3-hydroxy-kynurenine, enzymes for ommochrome synthesis and transferase, and spermatiation. Moreover, we confirmed that both decarboxylated xanthommatin and xanthommatin are major ommochrome pigments, and the quantity of decarboxylated xanthommatin is much higher than that of xanthommatin in silkworm eggs. Since ommochrome pigments can change color under oxidative/reductive conditions and the egg color mutant re turns crimson when preserved at a low temperature for a few weeks, we used an oxidation-reduction reaction in vitro to explore mechanisms behind the pigment-based color change. Specifically, during diapause, the contents of decarboxylated xanthommatin and xanthommatin are increased, and the ommochrome pigments convert into their reduced forms.

Safety and efficacy of splenic artery coil embolization for hypersplenism in liver cirrhosis.

BACKGROUND: Partial splenic artery embolization is an effective treatment for hypersplenism but often lacks long-term benefits. PURPOSE: To evaluate the long-term effects of coil embolization of the splenic artery in patients with liver cirrhosis and hypersplenism. MATERIAL AND METHODS: Forty-nine patients with liver cirrhosis and hypersplenism underwent coil embolization of the main splenic artery. The coils were deployed in the mid- or distal segment of the splenic artery to allow collateral blood flow to the spleen. The following data were collected from 2 weeks to 4 years after the embolization: technical success, length of hospital stay, white blood cell count, platelet count, splenic volume, and complication. RESULTS: The technical success rate of splenic artery coil embolization was 100%. The post embolization syndrome rate was 75% (36/49) with no incidence of major complications. The mean length of hospital stay was 9 days. After embolization, the patient's white blood and platelet counts increased significantly, peaked at 2 weeks, and gradually decreased during the 4-year follow-up period, but remained at significantly higher levels than pre-embolization levels. Follow-up CT scans demonstrated a gradual increase in the volume of the enhanced portions of the spleens with a decrease in the volume of unenhanced portion. No significant changes occurred in the red blood cell count and liver function after the embolization. CONCLUSION: Embolization of the mid-and distal main splenic artery with coils is a safe and effective treatment of hypersplenism in cirrhosis with long-term hematologic benefits.

Comparison of total splenic artery embolization and partial splenic embolization for hypersplenism.

AIM: To evaluate whether total splenic artery embolization (TSAE) for patients with hypersplenism delivers better long-term outcomes than partial splenic embolization (PSE). METHODS: Sixty-one patients with hypersplenism eligible for TSAE (n = 27, group A) or PSE (n = 34, group B) were enrolled into the trial, which included clinical and computed tomography follow-up. Data on technical success, length of hospital stay, white blood cell (WBC) and platelet (PLT) counts, splenic volume and complications were collected at 2 wk, 6 mo, and 1, 2, 3, 4 years postoperatively. RESULTS: Both TSAE and PSE were technically successful in all patients. Complications were significantly fewer (P = 0.001), and hospital stay significantly shorter (P = 0.007), in group A than in group B. Post-procedure WBC and PLT counts in group A were significantly higher than those in group B from 6 mo to 4 years (P = 0.001), and post-procedure residual splenic volume in group A was significantly less than that observed in group B at 1, 2, 3 and 4 years post-procedure (P = 0.001). No significant differences were observed in red blood cell counts and liver function parameters between the two groups following the procedure. CONCLUSION: Our results indicate that TSAE for patients with hypersplenism not only delivers a better long-term outcome, but is also associated with lower complication rates and a shorter hospital stay than PSE.

[Studies on the infection status of seven species Mycoplasma, three species of Chlamydia, Neisseria gonorrhoeae and Garderella vaginalis in 76 patients with sexual transmitted diseases].

OBJECTIVE: To study the infectious status of seven species of Mycoplasma, three species of Chlamydia, Neisseria gonorrhoeae and Garderella vaginalis in the 76 male sexual transmitted disease (STD) patients in Yangzhou city. METHODS: Twelve species of pathogens including Ureaplasma urealyticum (Uu), Mycoplasma hominis (Mh), Mycoplasma pneumoniae (Mpn), Mycoplasma genitalium (Mg), Mycoplasma fermentans (Mf), Mycoplasma penetrans (Mpe), Mycoplasma prium (Mpi), Chlamydia trachomatis (Ct), Chlamydia pneumoniae (Cpn), Chlamydia psittaci (Cps), Neisseria gonorrhoeae (Ng) and Garderella vaginalis (GV) were detected by nested polymerase chain reaction including PPNG. RESULTS: The positive rates of Uu, Mh, Mpn, Mg, Mf, Mpe, Ct, Ng were 64.5%, 27.6%, 26.3%, 18.4%, 2.6%, 2.6%, 31.6%, 36.8%, in which Penicillinase-producing neisseria gonorrhoeae (PPNG) accounted for 14.3%, GV 15.8%. No Mpi, Cpn or Cps were found. There was more significant therapeutic effects on the detectable rate of Mycoplasma nucleic acid between positive gonococcus and negative gonococcus in male STDs patients (chi(2) = 3.848, P < 0.05). CONCLUSION: The infection rates of Mycoplasma, Chlamydia, Ng and GV were high among male STD patients in Yangzhou city. In clinical practice, more attention should be paid on correct diagnosis and treatment for patients, with Gonococcus, Chlamydia, Mycoplasma and GV.