Cell death dependent on holins LrgAB repressed by a novel ArsR family regulator CdsR.

The cell death and survival paradox in various biological processes requires clarification. While spore development causes maternal cell death in Bacillus species, the involvement of other cell death pathways in sporulation remains unknown. Here, we identified a novel ArsR family transcriptional regulator, CdsR, and found that the deletion of its encoding gene cdsR causes cell lysis and inhibits sporulation. To our knowledge, this is the first report of an ArsR family transcriptional regulator governing cell death. We found that CdsR directly repressed lrgAB expression. Furthermore, lrgAB overexpression resulted in cell lysis without sporulation, akin to the cdsR mutant, suggesting that LrgAB, a holin-like protein, induces cell death in Bacillus spp. The lrgAB mutation increases abnormal cell numbers during spore development. In conclusion, we propose that a novel repressor is vital for inhibiting LrgAB-dependent cell lysis.

A Novel Regulator PepR Regulates the Expression of Dipeptidase Gene pepV in Bacillus thuringiensis.

Bacillus thuringiensis produces insecticidal crystal proteins encoded by cry or cyt genes and targets a variety of insect pests. We previously found that a strong promoter of a DeoR family transcriptional regulator (HD73_5014) can efficiently drive cry1Ac expression in B. thuringiensis HD73. Here, we investigated the regulation of neighbor genes by HD73_5014. The HD73_5014 homologs are widely distributed in Gram-positive bacterial species. Its neighbor genes include pepV, rsuA, and ytgP, which encode dipeptidase, rRNA pseudouridine synthase and polysaccharide biosynthesis protein, respectively. The four open reading frames (ORFs) are organized to be a pepR gene cluster in HD73. RT-PCR analysis revealed that the rsuA and ytgP genes formed a transcriptional unit (rsuA-ytgP operon), while pepV formed a transcriptional unit in HD73. Promoter-lacZ fusion assays showed that the pepV and rsuA-ytgP promoters are regulated by HD73_5014. EMSA experiments showed that HD73_5014 directly binds to the pepV promoter region but not to the rusA-ytgP promoter region. Thus, the HD73_5014 transcriptional regulator, which controls the expression of the dipeptidase pepV, was named PepR (dipeptidase regulator). We also confirmed the direct regulation between PepR and PepV by the increased sensitivity to vancomycin in ΔpepV and ΔpepR mutants compared to HD73.

Characterization of metabolic patterns in porcine cumulus cells during meiotic maturation.

Metabolic coupling between oocytes and the surrounding somatic cells allows for normal two-way communication, and their interactions is necessary for generating developmentally competent eggs. However, the metabolic framework that support oocyte maturation in surrounding cumulus cells is still lacking. Herin, we established a temporal metabolome profile of porcine cumulus cells at three key stages during oocyte maturation, illustrating the picture of global metabolic network in cumulus cells. Importantly, we discovered the novel metabolic signature in cumulus cells during meiotic maturation, in specific, significant consumption of fatty acids, elevated activity of hexosamine biosynthetic pathway (HBP), and enhanced polyamine biosynthesis. Meanwhile, we observed the different utilization of tryptophan, active biosynthesis of progesterone, and progressive decrease in purine and pyrimidine metabolism as the oocytes progress through meiosis. Collectively, our metabolomic data serves an entree to elaborate on the dynamic changes in these metabolic pathways, which not only reveals the metabolic networks controlling oocyte development, but also lays a foundation for the discovery of biomarkers in the improvement in porcine oocyte culture system.

Botryorhodine J, a new anti-MRSA depsidone isolated from endophytic fungus Alternaria alternata Pas11.

A new depsidone derivative botryorhodine J (1), along with six known compounds (2-7) were obtained from solid rice cultures of Alternaria alternata Pas11 that was isolated from leaves of Phragmites australis. The structure of the new compound was elucidated on the basis of combination of NMR spectroscopic data and high resolution mass spectrometry (HRMS). All the isolated compounds were evaluated for their antibacterial activities against a panel of Gram-positive bacterial strains (methicillin-resistant Staphylococcus aureus [MRSA], Bacillus subtilis and S. aureus). Compounds 1 and 6 displayed antibacterial activity against the three bacterial strains with the minimum inhibitory concentration values (MICs) of 14 - 32 µg/mL, while compound 5 showed good antibacterial activity against above bacterial strains with MIC values of 5 - 8 µg/mL.

Integration of parallel metabolomics and transcriptomics reveals metabolic patterns in porcine oocytes during maturation.

Well-controlled metabolism is the prerequisite for optimal oocyte development. To date, numerous studies have focused mainly on the utilization of exogenous substrates by oocytes, whereas the underlying mechanism of intrinsic regulation during meiotic maturation is less characterized. Herein, we performed an integrated analysis of parallel metabolomics and transcriptomics by isolating porcine oocytes at three time points, cooperatively depicting the global picture of the metabolic patterns during maturation. In particular, we identified the novel metabolic features during porcine oocyte meiosis, such as the fall in bile acids, the active one-carbon metabolism and a progressive decline in nucleotide metabolism. Collectively, the current study not only provides a comprehensive multiple omics data resource, but also may facilitate the discovery of molecular biomarkers that could be used to predict and improve oocyte quality.

NAMPT reduction-induced NAD+ insufficiency contributes to the compromised oocyte quality from obese mice.

Maternal obesity is associated with multiple adverse reproductive outcomes, whereas the underlying molecular mechanisms are still not fully understood. Here, we found the reduced nicotinamide phosphoribosyl transferase (NAMPT) expression and lowered nicotinamide adenine dinucleotide (NAD+ ) content in oocytes from obese mice. Next, by performing morpholino knockdown assay and pharmacological inhibition, we revealed that NAMPT deficiency not only severely disrupts maturational progression and meiotic apparatus, but also induces the metabolic dysfunction in oocytes. Furthermore, overexpression analysis demonstrated that NAMPT insufficiency induced NAD+ loss contributes to the compromised developmental potential of oocytes and early embryos from obese mice. Importantly, in vitro supplement and in vivo administration of nicotinic acid (NA) was able to ameliorate the obesity-associated meiotic defects and oxidative stress in oocytes. Our results indicate a role of NAMPT in modulating oocyte meiosis and metabolism, and uncover the beneficial effects of NA treatment on oocyte quality from obese mice.

LncRNA BACE1-AS enhances the invasive and metastatic capacity of hepatocellular carcinoma cells through mediating miR-377-3p/CELF1 axis.

AIMS: Hepatocellular carcinoma (HCC) is a malignant cancer that threatened human life seriously. Long non-coding RNA (lncRNA) BACE1-AS has been reported as a key regulator in tumorigenesis. Yet the specific correlation between BACE1-AS and HCC still needs further investigation. The primary purpose of our study is to reveal the exact correlation between BACE1-AS and HCC. MAIN METHODS: Bioinformatics via TCGA database revealed BACE1-AS closely related with HCC. qRT-PCR confirmed the abnormal BACE1-AS level in HCC tissues and cells. Databases prediction suggested that miR-377-3p might be a modulatory target of BACE1-AS and luciferase assay confirmed this hypothesis. Further study discovered that CELF1 also partook in the regulatory axis of BACE1-AS/miR-377-3p. Wound healing assays and transwell assays were utilized to investigate the impact of BACE1-AS, miR-377-3p and CELF1 in vitro. In vivo metastasis was examined by pulmonary metastasis model. KEY FINDINGS: This study found that BACE1-AS was overexpressed in HCC tissues and cell lines. Knockdown of BACE1-AS could restrain HCC progression in vitro, and inhibit pulmonary metastasis in vivo. MiR-377-3p was negatively modulated by BACE1-AS in HCC tumor tissues and cells. MiR-377-3p up-regulation inhibited HCC cells migration and invasion via inactivating EMT process. Moreover, CELF1 was identified as a downstream regulator of miR-377-3p and served as an oncogene in HCC cells. SIGNIFICANCE: Our findings supported that lncRNA BACE1-AS was up-regulated in HCC, promoting invasion and metastasis of hepatocellular carcinoma cells by modulating miR-377-3p/CELF1 axis via contributing to EMT pathway. BACE1-AS could be a potential biomarker in HCC for future treatment.

ASB7 Is a Novel Regulator of Cytoskeletal Organization During Oocyte Maturation.

Ankyrin repeat and SOCS box (ASB) family members have a C-terminal SOCS box and an N-terminal ankyrin-related sequence of variable repeats. To date, the roles of ASB family members remain largely unknown. In the present study, by employing knockdown analysis, we investigated the effects of ASB7 on mouse oocyte meiosis. We show that specific depletion of ASB7 disrupts maturational progression and meiotic apparatus. In particular, abnormal spindle, misaligned chromosomes, and loss of cortical actin cap are frequently observed in ASB7-abated oocytes. Consistent with this observation, incidence of aneuploidy is increased in these oocytes. Meanwhile, confocal scanning reveals that loss of ASB7 impairs kinetochore-microtubule interaction and provokes the spindle assembly checkpoint during oocyte meiosis. Furthermore, we find a significant reduction of ASB7 protein in oocytes from aged mice. Importantly, increasing ASB7 expression is capable of partially rescuing the maternal age-induced meiotic defects in oocytes. Together, our data identify ASB7 as a novel player in regulating cytoskeletal organization and discover the potential effects of ASB7 on quality control of aging oocytes.

miR-96 regulates liver tumor-initiating cells expansion by targeting TP53INP1 and predicts Sorafenib resistance.

Liver tumor-initiating cells (T-ICs) contribute to tumorigenesis, progression, recurrence and drug resistance of hepatocellular carcinoma (HCC). However, the underlying mechanism for the propagation of liver T-ICs remains unclear. In the present study, our finding shows that miR-96 is upregulated in liver T-ICs. Functional studies revealed that forced miR-96 promotes liver T-ICs self-renewal and tumorigenesis. Conversely, knockdown miR-96 inhibits liver T-ICs self-renewal and tumorigenesis. Mechanistically, miR-96 downregulates TP53INP1 via its mRNA 3'UTR in liver T-ICs. Furthermore, the miR-96 expression determines the responses of hepatoma cells to sorafenib treatment. Analysis of patient cohorts and patient-derived xenografts (PDXs) further demonstrate that the miR-96 may predict sorafenib benefits in HCC patients. Our findings revealed the crucial role of the miR-96 in liver T-ICs expansion and sorafenib response, rendering miR-96 as an optimal target for the prevention and intervention of HCC.