Dual roles of α1,4-galactosyltransferase 1 in spermatogenesis of Drosophila melanogaster.

Spermatogenesis is critical for insect reproduction and the process is regulated by multiple genes. Glycosyltransferases have been shown to participate in the development of Drosophila melanogaster; however, their role in spermatogenesis is still unclear. In this study, we found that α1,4-galactosyltransferase 1 (α4GT1) was expressed at a significantly higher level in the testis than in the ovary of Drosophila. Importantly, the hatching rate was significantly decreased when α4GT1 RNA interference (RNAi) males were crossed with w1118 females, with only a few mature sperm being present in the seminal vesicle of α4GT1 RNAi flies. Immunofluorescence staining further revealed that the individualization complex (IC) in the testes from α4GT1 RNAi flies was scattered and did not move synchronically, compared with the clustered IC observed in the control flies. Terminal deoxyribonucleotide transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay showed that apoptosis signals in the sperm bundles of α4GT1 RNAi flies were significantly increased. Moreover, the expression of several individualization-related genes, such as Shrub, Obp44a and Hanabi, was significantly decreased, whereas the expression of several apoptosis-related genes, including Dronc and Drice, was significantly increased in the testes of α4GT1 RNAi flies. Together, these results suggest that α4GT1 may play dual roles in Drosophila spermatogenesis by regulating the sperm individualization process and maintaining the survival of sperm bundles.

Identification and functional analysis of CG3526 in spermatogenesis of Drosophila melanogaster.

Spermatogenesis is a critical part of reproduction in insects; however, its molecular mechanism is still largely unknown. In this study, we identified a testis-specific gene CG3526 in Drosophila melanogaster. Bioinformatics analysis showed that CG3526 contains a zinc binding domain and 2 C2 H2 type zinc fingers, and it is clustered to the vertebrate really interesting new gene (RING) family E3 ubiquitin-protein ligases. When CG3526 was knocked down by RNA interference (RNAi), the testis became much smaller in size, and the apical tip exhibited a sharp and thin end instead of the blunt and round shape in the control testis. More importantly, compared to the control flies, only a few mature sperm were present in the seminal vesicle of C587-Gal4 > CG3526 RNAi flies. Immunofluorescence staining of the testis from CG3526 RNAi flies showed that the homeostasis of testis stem cell niche was disrupted, cell distribution in the apical tip was scattered, and the process of spermatogenesis was not completed. Furthermore, we found that the phenotype of CG3526 RNAi flies' testis was similar to that of testis of Stat92E RNAi flies, the expression level of CG3526 was significantly downregulated in the Stat92EF06346 mutant flies, and the promoter activity of CG3526 was upregulated by STAT92E. Taken together, our results indicated that CG3526 is a downstream effector gene in the JAK-STAT signaling pathway that plays a key role in the spermatogenesis of Drosophila.

ANGPTL4, a direct target of hsa-miR-133a-3p, accelerates lung adenocarcinoma lipid metabolism, proliferation and invasion.

BACKGROUND: Globally, lung adenocarcinoma (LUAD) is the most common type of lung cancer. The secreted protein angiopoietin-like 4 (ANGPTL4) has been implicated in a number of physiological and pathological processes, including angiogenesis and lipid metabolism. But the role of ANGPTL4 in LUAD remains unknown. METHODS: The expression of ANGPTL4 and miR-133a-3p was confirmed by public database analysis. Xenograft model, MTT, Clone formation and EdU analysis were used to confirm the effects of miR-133a-3p/ANGPTL4 on LUAD cell proliferation and growth. Wound healing and Transwell analysis were used to elucidate the role of miR-133a-3p/ANGPTL4 in LUAD cell migration and invasion. Oil red O staining was used to confirm ANGPTL4 in LUAD lipids production. Dual-luciferase reporter gene analysis was used to demonstrate miR-133a-3p could directly bind ANGPTL4 3'-UTR. WB and PCR were used to confirm the protein expression of ANGPTL4. RESULTS: ANGPTL4 was significantly increased in LUAD samples, which could promote LUAD cell proliferation, migration, invasion, growth and lipid production. miR-133a-3p could directly bind to ANGPTL4 mRNA, and repress the expression ANGPTL4, resulting in suppressing LUAD proliferation and metastasis. CONCLUSION: In conclusion, miR-133a-3p/ANGPTL4 axis might be a potential biomarker and therapeutic target for LUAD patients.

Miniature Fabry-Perot Cavity Based on Fiber Bragg Gratings Fabricated by Fs Laser Micromachining Technique.

Fabry-Perot cavity (FPC) based on Fiber Bragg gratings (FBGs) is an excellent candidate for fiber sensing and high-precision measurement. The advancement of the femtosecond laser micromachining technique provides more choices for the fabrication of FBGs-based FPCs. In this paper, we fabricate miniature FBGs-based FPCs, using the femtosecond laser line-by-line scanning writing technique for the first time. By this method, the FBGs can be limited to a specific area in the fiber core region. The grating length, position, and the distance between two successive FBGs can be conveniently controlled to achieve the desired transmission spectrum. For future applications in sensing, the temperature and strain responses of the fabricated FBGs-based FPCs were studied experimentally. This work provides a meaningful guidance for the fabrication and application of miniature FPCs based on FBGs.

Identification of Biomarkers Related to CD8+ T Cell Infiltration With Gene Co-expression Network in Lung Squamous Cell Carcinoma.

Lung squamous cell carcinoma (LSCC) is one of the most common types of lung cancer in adults worldwide. With the development of modern medicine, cancer treatment that harnesses the power of the immune system might be particularly effective for treating LSCC. In this research, LSCC expression data, which quantify the cellular composition of immune cells, were analyzed by weighted gene coexpression network analysis (WGCNA) and a deconvolution algorithm based on the Gene Expression Omnibus (GEO) database, and the results indicated a close relationship between LSCC and CD8+ T cells. Six hub genes (SYT3, METTL8, HSPB3, GFM1, ERLIN2, and CLCN2) were verified by gene-gene network and protein-protein interaction (PPI) network analyses. We found that the six hub genes were increased in cancer tissues and were closely correlated with cancer development and progression. After immune correlation analysis, METTL8 was selected as a prognostic biomarker. Finally, we found that the METTL8 levels were increased in multiple lung cancer cell lines and LSCC tissues. METTL8 inhibition could clearly induce G1 cell cycle arrest and suppress proliferation. Therefore, METTL8, which is related to CD8+ T cell infiltration, might be identified as a potential biomarker and gene therapy target in LSCC.

Transcriptomic analysis reveals the regulation network of BmKrüppel homolog 1 in the oocyte development of Bombyx mori.

Krüppel homolog 1 (Kr-h1), a zinc finger transcription factor, is involved in the metamorphosis and adult reproduction of insects. However, the role of Kr-h1 in reproduction of holometabolic insects remains to be elucidated. The regulation network of Kr-h1-associated genes in the reproduction in Bombyx mori was investigated in this study. The higher expression level of BmKr-h1 in the ovaries was detected during the late pupal stage and adults. RNA interference (RNAi)-mediated depletion of BmKr-h1 in the female at day 6 of pupae resulted in abnormal oocytes at 48 h post-double-stranded RNA treatment, which showed less yolk protein deposition and partially transparent chorion. RNA-seq and subsequent differentially expressed transcripts analysis showed that knockdown of BmKr-h1 caused a decrease in the expression of 2882 genes and an increase in the expression of 2565 genes in the oocytes at day 8 of pupae. Totally, 27 genes coding for transcription factors were down-regulated, while six genes coding for other transcription factors were up-regulated. BmKr-h1 bound to the Kr-h1 binding site of the transcription factors AP-1 (activating protein-1) and FOXG1 to increase their messenger RNA transcripts in the BmN cells, respectively. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses of that positively co-expressed with AP-1 and FOXG1 transcripts showed mainly enrichment in the metabolic-related pathways, the nutrient absorption and the yolk protein absorption processes. These data suggested that BmKr-h1 might directly regulate the metabolic-related pathways, the nutrient absorption and the yolk protein absorption processes or probably through AP-1 and /or FOXG1 to regulate oocyte development.

Comparative genomic analysis of C-type lectin-domain genes in seven holometabolous insect species.

C-type lectins (CTLs) recognize various glycoconjugates through carbohydrate recognition domains (CRDs) and they play important roles in immune responses. In this study, comparative genomic analysis of CTLs were performed in 7 holometabolous species. CTL-S1 to S8 and CTL-X1 to X4 orthologous groups existed in the 7 species, while CTL-X5 group with dual-CRD, CTL-S11 group with triple-CRD, CTL-S9 group with a long C-terminus and Lepidopteran specific CTL-S10 group were not conserved. SliCTL-S12 to S14 cluster was only present in Spodoptera litura, and CTL-S genes were expanded on chromosomes 2 L and 2 R in Drosophila melanogaster. Most IMLs were clustered into three groups and the numbers of IMLs vary among species due to gene duplications. D. melanogaster specific CTLs and Lepidopteran IMLs within each of the three groups evolved more rapidly with higher dN/dS ratios. Two CRDs in IMLs clustered into two clades, with conserved Cys4-Cys5 and Cys1-Cys2 bonds in the first and second CRDs, respectively. The CTL-S and CTL-X family members in S. litura were mainly expressed in the fat body of 5th but not 6th instar larvae, and responded differently to S. litura nucleopolyhedrovirus (SpltNPV) and Nomuraea rileyi infection. The transcription levels of SliCTLs that expressed in fat body but not highly expressed in hemocytes were decreased at the middle and late stages of SpltNPV infection, and the mRNA levels of SliCTLs highly or specifically expressed in hemocytes were mainly decreased by SpltlNPV, N. rileyi and Bacillus thuringiensis infection. These results provide valuable information for further exploration of CTL functions in host-pathogen interaction.

Influence of Bragg reflection of chirped tilted fiber Bragg grating on Raman suppression in high-power tandem pumping fiber amplifiers.

The key remaining technological challenge to the realization of further power scaling for high-power fiber laser systems is overcoming the stimulated Raman scattering (SRS) effect. In past years, chirped and tilted fiber Bragg gratings (CTFBGs) have been demonstrated to be a simple and effective way to suppress SRS in high-power fiber amplifiers. However, the weak reflection at the Bragg wavelength could be strongly amplified, which not only limits the power and efficiency but also degrades the beam quality. We report here, for the first time to the best of our knowledge, the influence of the residual Bragg reflection of CTFBGs on SRS suppression in high-power fiber laser systems. Two groups of CTFBGs with different Bragg reflection wavelengths are fabricated and used for the comparison experiments. Test results show that the CTFBGs of longer Bragg wavelengths have a better suppression effect, in particular, at a higher power level. By further moving the Bragg wavelength of a CTFBG out of the Raman gain spectral range, a better suppression effect and a promotion in laser efficiency could be achieved, which is very useful for further power scaling.

Immunological role and underlying mechanisms of B7-H6 in tumorigenesis.

B7 homolog 6 (B7-H6) has been identified as involved in tumorigenesis. Elucidating its role and potential mechanism of action is essential for understanding tumorigenesis and the potential development of an effective clinical strategy. Abnormal overexpression of B7-H6 in various types of tumors was reported to be linked with poor prognosis. B7-H6 suppresses the initiation of the "caspase cascade" and induces anti-apoptosis by STAT3 pathway activation to provoke tumorigenesis. B7-H6 facilitates tumor proliferation and cell cycle progression by regulating apoptosis suppressors. B7-H6 induces cellular cytotoxicity, secretion of TNF-α and IFN-γ and B7-H6-specific BiTE triggers T cells to accelerate tumorigenesis. B7-H6 induces abnormal immunological progression by HER2-scFv mediated ADCC and NKp30 immune escape to promote tumorigenesis. B7-H6 promotes tumorigenesis via apoptosis inhibition, proliferation and immunological progression. B7-H6 may a valuable potential biomarker and therapeutic strategy for diagnostics, prognostics and treatment in cancer.

Pattern recognition receptors in Drosophila immune responses.

Insects, which lack the adaptive immune system, have developed sophisticated innate immune system consisting of humoral and cellular immune responses to defend against invading microorganisms. Non-self recognition of microbes is the front line of the innate immune system. Repertoires of pattern recognition receptors (PRRs) recognize the conserved pathogen-associated molecular patterns (PAMPs) present in microbes, such as lipopolysaccharide (LPS), peptidoglycan (PGN), lipoteichoic acid (LTA) and ß-1, 3-glucans, and induce innate immune responses. In this review, we summarize current knowledge of the structure, classification and roles of PRRs in innate immunity of the model organism Drosophila melanogaster, focusing mainly on the peptidoglycan recognition proteins (PGRPs), Gram-negative bacteria-binding proteins (GNBPs), scavenger receptors (SRs), thioester-containing proteins (TEPs), and lectins.

Bombyx mori transcription factors FoxA and SAGE divergently regulate the expression of wing cuticle protein gene 4 during metamorphosis.

Stage-specific gene expression governs metamorphosis of the silkworm, Bombyx mori. B. mori wing cuticle protein gene 4 (BmWCP4) is an essential gene for wing disc development expressed specifically during pupation. BmWCP4 transcription is suppressed at the larval stage by unknown mechanisms, which we sought to elucidate here. Bioinformatics analysis predicted seven potential Forkhead box (Fox) cis-regulatory elements (CREs) in the BmWCP4 promoter region, and we found that Fox CRE6 contributes to suppression of BmWCP4 expression. Electrophoretic mobility shift (EMSA) and DNA pull-down assays revealed that BmFoxA suppressed activity at the BmWCP4 promoter by specifically binding to the Fox CRE6. The expression level of BmFoxA in the wing discs was higher during the larval stage than at the pupal stage. In contrast, expression of another transcription factor, BmSAGE, increased over the course of development. Of note, the hormone 20-hydroxyecdysone (20E), which governs molting in insects, suppressed BmFoxA expression in the wing discs and up-regulated that of BmSage EMSA and cell co-transfection assays indicated that BmSAGE interacted with BmFoxA and suppressed its binding to the Fox CRE6, thereby releasing BmFoxA-mediated suppression of BmWCP4 In summary, higher BmFoxA expression during the larval stage suppresses BmWCP4 expression by binding to the Fox CRE6 on the BmWCP4 promoter. During metamorphosis, BmSAGE forms a complex with BmFoxA to relieve this repression, initiating BmWCP4 expression. Taken together, this study reveals a switchlike role for BmFoxA in regulating BmWCP4 expression and provides new insights into the regulatory regulation of wing disc development in insects.

Identification of the binding domains and key amino acids for the interaction of the transcription factors BmPOUM2 and BmAbd-A in Bombyx mori.

The transcription factor BmPOUM2 interacted with another transcription factor BmAbd-A to regulate the expression of the wing cuticle protein gene BmWCP4 in Bombyx mori. In this study, the binding domains and amino acids for the interaction between BmPOUM2 and BmAbd-A were reported. Two isoforms of BmPOUM2 were identified. The short isoform (BmPOUM2-S) lacks a 114-amino acid sequence containing a POU-homeodomain and a nuclear localization signal peptide (NLS), as compared to the full-length isoform (BmPOUM2). Both BmPOUM2 and BmPOUM2-S proteins bound to the BmAbd-A through the POU-specific domain. When the six amino acids (Lys166, Gly173, Gln176, Ser192, Glu200 and Asn208) that are highly conserved in POU family genes were mutated, BmPOUM2 did not bind to BmAbd-A. BmAbd-A interacted with BmPOUM2 by the homeobox domain or the LCR2 (low complexity region) domain. When seven amino acids (Phe156/248, His158/250, Ala175/263, Cys180/265, Glu190/268, Trp196/274 and Val214/289) that are shared in the homeobox and LCR2 domains were mutated, BmAbd-A did not bind to BmPOUM2. Overexpression of either BmPOUM2 or BmAbd-A or both increased the activity of BmWCP4 promoter in CHO cells. ChIP assay and EMSA showed that BmAbd-A protein bound to the Hox cis-regulatory element in the BmWCP4 promoter, while the BmPOUM2 bound to the nearby POU CRE. A model for the interaction and action of BmPOUM2 and BmAbd-A in regulation of the BmWCP4 expression is proposed.