Synchronized expression of two caspase family genes, ice-2 and ice-5, in hydrogen peroxide-induced cells of the silkworm, Bombyx mori

Spindle-E is essential for gametogenesis in the silkworm, Bombyx mori

As a defense mechanism against transposable elements, the PIWI-interacting RNA (piRNA) pathway maintains genomic integrity and ensures proper gametogenesis in gonads. Numerous factors are orchestrated to ensure normal operation of the piRNA pathway. Spindle-E (Spn-E) gene was one of the first genes shown to participate in the piRNA pathway. In this study, we performed functional analysis of Spn-E in the model lepidopteran insect, Bombyx mori. Unlike the germline-specific expression pattern observed in Drosophila and mouse, BmSpn-E was ubiquitously expressed in all tissues tested, and it was highly expressed in gonads. Immunofluorescent staining showed that BmSpn-E was localized in both germ cells and somatic cells in ovary and was expressed in spermatocytes in testis. We used a binary transgenic CRISPR/Cas9 system to construct BmSpn-E mutants. Loss of BmSpn-E expression caused derepression of transposons in gonads. We also found that mutant gonads were much smaller than wild-type gonads and that the number of germ cells was considerably lower in mutant gonads. Quantitative real-time PCR analysis and TUNEL staining revealed that apoptosis was greatly enhanced in mutant gonads. Further, we found that the BmSpn-E mutation impacted gonadal development and gametogenesis at the early larval stage. In summary, our data provided the first evidence that BmSpn-E plays vital roles in gonadal development and gametogenesis in B. mori.

Ropivacaine inhibits proliferation, invasion, migration and promotes apoptosis of papillary thyroid cancer cells via regulating ITGA2 expression

The present study aimed to investigate the roles of Ropivacaine in papillary thyroid cancer (PTC) and identify the possible mechanisms. The expression of integrin alpha-2 (ITGA2) in TC cell lines was tested using Western blotting and RT-qPCR. Subsequently, the level of ITGA2 in human PTC cell line (TPC-1) was measured following intervention with a series of concentrations of Ropivacaine. Then, cell counting kit-8 (CCK-8) assay and colony formation assay were executed for detecting proliferation of cells after transfection with ITGA2 pcDNA3.1. The expression of proliferation-related protein was determined by Western blotting. Additionally, the abilities of TPC-1 cell invasion and migration were examined using Transwell assay and scratch wound healing assay. Apoptosis of TPC-1 cells was analyzed using TUNEL assay and the expressions of apoptosis-related proteins were tested via West blotting. The results suggested that ITGA2 was highly expressed in TC cell lines, especially in TPC-1 cells. Ropivacaine decreased the expression of ITGA2 in a dose-dependent manner. Moreover, after treatment with Ropivacaine, cell proliferation was inhibited accompanied by changes of proliferation-related protein expressions, which was reversed following co-transfection with ITGA2 pcDNA3.1. Furthermore, Ropivacaine concentration-dependently suppressed invasion and migration of TPC-1 cells, whereas these inhibitory effects were attenuated after ITGA2 overexpression. Furthermore, apoptosis was promoted, coupled with a decrease of Bcl-2 expression and increases of Bax, cleaved caspase-3 and cleaved caspase-9 expression, in Ropivacaine-treated TPC-1 cells, which was restored following ITGA2 overexpression. These findings demonstrated that Ropivacaine could suppress proliferation, invasion, migration, and accelerate apoptosis of PTC cells via regulating ITGA2 expression.

Maelstrom regulates spermatogenesis of the silkworm, Bombyx mori

The spermatogenesis of animal is essential for the reproduction and a very large number of genes participate in this procession. The Maelstrom (Mael) is identified essential for spermatogenesis in both Drosophila and mouse, though the mechanisms appear to differ. It was initially found that Mael gene is necessary for axis specification of oocytes in Drosophila, and recent studies suggested that Mael participates in the piRNA pathway. In this study, we obtained Bombyx mori Mael mutants by using a binary transgenic CRISPR/Cas9 system and analyzed the function of Mael in B. mori, a model lepidopteran insect. The results showed that BmMael is not necessary for piRNA pathway in the ovary of silkworm, whereas it might be essential for transposon elements (TEs) repression in testis. The BmMael mutation resulted in male sterility, and further analysis established that BmMael was essential for spermatogenesis. The spermatogenesis defects occurred in the elongation stage and resulted in nuclei concentration arrest. RNA-seq and qRT-PCR analyses demonstrated that spermatogenesis defects were associated with tight junctions and apoptosis. We also found that BmMael was not involved in the silkworm sex determination pathway. Our data provide insights into the biological function of BmMael in male spermatogenesis and might be useful for developing novel methods to control lepidopteron pests.

In vivo and in vitro effects of hyperplasia suppressor gene on the proliferation and apoptosis of lung adenocarcinoma A549 cells

Lung adenocarcinoma is the most common subtype of non-small cell lung cancer (NSCLC). Hyperplasia suppressor gene (HSG) has been reported to inhibit cell proliferation, migration, and remodeling in cardiovascular diseases. However, there lacks systematic researches on the effect of HSG on the apoptosis and proliferation of lung adenocarcinoma A549 cells and data of in vivo experiments. The present study aims to investigate the effects of HSG gene silencing on proliferation and apoptosis of lung adenocarcinoma A549 cells. The human lung adenocarcinoma A549 cell was selected to construct adenovirus vector. Reverse transcription-quantitative PCR (RT-qPCR) and Western blot analysis were conducted to detect expressions of HSG and apoptosis related-proteins. Cell Counting Kit (CCK)-8 assay was performed to assess A549 cell proliferation and flow cytometry to analyze cell cycle and apoptosis rate. The BALB/C nude mice were collected to establish xenograft model. Silenced HSG showed decreased mRNA and protein expressions of HSG, and elevated A549 cell survival rates at the time point of 24, 48, and 72 h. The ratio of cells at G₀/G₁ phase and apoptosis rate decreased and the ratio of cells at S- and G₂/M phases increased following the silencing of HSG. There were decreases of B cell lymphoma-2 (Bcl-2)-associated X protein (Bax), Caspase-3, and Caspase-8 expressions but increases in Bcl-2 induced by silenced HSG. As for the xenograft in nude mice, tumor volume increased, and apoptosis index (AI) decreased after HSG silencing. These results indicate that HSG gene silencing may promote the proliferation of A549 cells and inhibit the apoptosis. HSG may be a promising target for the treatment of lung adenocarcinoma.