Effects of maize straw and its biochar application on soil organic carbon chemical composition and carbon degradation genes in a Moso bamboo forest.

We investigated the effects of maize straw and its biochar application on soil organic carbon chemical composition, the abundance of carbon degradation genes (cbhI) and the composition of cbhI gene community in a Moso bamboo forest, to provide the theoretical and scientific basis for enhancing carbon sequestration. We conducted a one-year field experiment in a subtropical Moso bamboo forest with three treatments: control (0 t C·hm-2), maize straw (5 t C·hm-2), and maize straw biochar (5 t C·hm-2). Soil samples were collected at the 3rd and 12th months after the treatment. Soil organic carbon chemical composition, the abundance and community composition of cbhI gene were determined by solid-state 13C NMR, real-time fluorescence quantitative PCR, and high-throughput sequencing, respectively. The results showed that compared with the control, maize straw treatment significantly increased the content of O-alkyl C and decreased aromatic C content, while maize straw biochar treatment showed an opposite effect. Maize straw treatment significantly increased the abundance of cbhI gene and the relative abundance of Penicillium, Gaeumannomyces and Marasmius. However, maize straw biochar treatment reduced the abundance of this gene. The relative abundance of dominant cbhI in soils was positively correlated with the content of O-alkyl C and negatively correlated with the content of aromatic C. Results of redundancy analysis showed that maize straw treatment had a significant effect on the microbial community composition of cbhI gene by changing soil O-alkyl C content, while maize straw biochar affected the microbial community composition of cbhI gene by changing soil pH, organic carbon, and aromatic C content. Maize straw biochar treatment was more effective in increasing soil organic carbon stability and reducing microbial activity associated with carbon degradation in the subtropical Moso bamboo forest ecosystem compared with maize straw treatment. Therefore, the application of biochar has positive significance for maintaining soil carbon storage in subtropical forest ecosystems.

The Discovery, Enzymatic Characterization and Functional Analysis of a Newly Isolated Chitinase from Marine-Derived Fungus Aspergillus fumigatus df347.

In order to discover a broad-specificity and high stability chitinase, a marine fungus, Aspergillus fumigatus df347, was identified in the sediments of mangrove wetlands in Qinzhou Bay, China. The chitinase gene (AfChi28) from A. fumigatus df347 was cloned and heterologously expressed in Escherichia coli, and the recombinant enzyme AfChi28 was purified and characterized. AfChi28 is an acido-halotolerant- and temperature-resistant bifunctional enzyme with both endo- and exo-cleavage functions. Its enzymatic products are mainly GlcNAc, (GlcNAc)2, (GlcNAc)3 and (GlcNAc)4. Na+, Mg2+, K+, Ca2+ and Tris at a concentration of 50 mM had a strong stimulatory effect on AfChi28. The crude enzyme and pure enzyme exhibited the highest specific activity of 0.737 mU/mg and 52.414 mU/mg towards colloidal chitin. The DxDxE motif at the end of strand ß5 and with Glu154 as the catalytic residue was verified by the AlphaFold2 prediction and sequence alignment of homologous proteins. Moreover, the results of molecular docking showed that molecular modeling of chitohexaose was shown to bind to AfChi28 in subsites -4 to +2 in the deep groove substrate-binding pocket. This study demonstrates that AfChi28 is a promising chitinase for the preparation of desirable chitin oligosaccharides, and provides a foundation for elucidating the catalytic mechanism of chitinases from marine fungi.

Efficacy and safety of two different adjuvant chemotherapy regimens in combination with concurrent chemoradiotherapy in treating patients with advanced nasopharyngeal carcinoma: A protocol for randomized controlled trial.

BACKGROUND: Concurrent chemoradiotherapy is widely utilised as a standardized primary method of treatment for patients with advanced nasopharyngeal carcinoma (NPC). However, the combination of concurrent chemoradiotherapy and adjuvant chemotherapy for treating NPC patients remain unclear. Therefore, this study attempts to elucidate the efficiency and safety of concurrent chemoradiotherapy combined with adjuvant chemotherapy (gemcitabine plus cisplatin versus 5-fluorouracil plus cisplatin) for treating patients with NPC. MATERIALS AND METHODS: This study is a randomized, multicentral, open-labelled trial to assess the clinical efficiency and safety of using concurrent chemoradiotherapy combined with adjuvant chemotherapy as a therapeutic measure for advanced NPC patients. A total of 50 patients will be randomly assigned into 2 groups, namely treatment-group-one and treatment-group-two. Eligible patients will be administered with concurrent chemoradiotherapy and subsequentially with adjuvant chemotherapy (gemcitabine plus cisplatin or 5-fluorouracil plus cisplatin). Moreover, the primary endpoint is a comparison of progression-free survival between concurrent chemoradiotherapy and subsequentially adjuvant gemcitabine and cisplatin and chemoradiotherapy, which is proceeded by adjuvant 5-fluorouracil and cisplatin in advanced NPC patients. Overall survival, overall response rate, incidence of acute and late toxicity, and adverse events are the minor endpoints. Statistical analyses will be performed with SPSS 25.0 software. DISCUSSION: The current research evaluates the clinical efficiency and safety of utilising concurrent chemoradiotherapy combined with adjuvant chemotherapy as a therapeutic strategy to treat advanced NPC patients. The work done in this study will provide a clinical basis for concurrent chemoradiotherapy in combination with adjuvant chemotherapy for treating advanced NPC. TRIAL REGISTRATION: DOI 10.17605/OSF.IO/5UPVM.

Potentials of marine natural products against malaria, leishmaniasis, and trypanosomiasis parasites: a review of recent articles.

BACKGROUND: Malaria and neglected communicable protozoa parasitic diseases, such as leishmaniasis, and trypanosomiasis, are among the otherwise called diseases for neglected communities, which are habitual in underprivileged populations in developing tropical and subtropical regions of Africa, Asia, and the Americas. Some of the currently available therapeutic drugs have some limitations such as toxicity and questionable efficacy and long treatment period, which have encouraged resistance. These have prompted many researchers to focus on finding new drugs that are safe, effective, and affordable from marine environments. The aim of this review was to show the diversity, structural scaffolds, in-vitro or in-vivo efficacy, and recent progress made in the discovery/isolation of marine natural products (MNPs) with potent bioactivity against malaria, leishmaniasis, and trypanosomiasis. MAIN TEXT: We searched PubMed and Google scholar using Boolean Operators (AND, OR, and NOT) and the combination of related terms for articles on marine natural products (MNPs) discovery published only in English language from January 2016 to June 2020. Twenty nine articles reported the isolation, identification and antiparasitic activity of the isolated compounds from marine environment. A total of 125 compounds were reported to have been isolated, out of which 45 were newly isolated compounds. These compounds were all isolated from bacteria, a fungus, sponges, algae, a bryozoan, cnidarians and soft corals. In recent years, great progress is being made on anti-malarial drug discovery from marine organisms with the isolation of these potent compounds. Comparably, some of these promising antikinetoplastid MNPs have potency better or similar to conventional drugs and could be developed as both antileishmanial and antitrypanosomal drugs. However, very few of these MNPs have a pharmaceutical destiny due to lack of the following: sustainable production of the bioactive compounds, standard efficient screening methods, knowledge of the mechanism of action, partnerships between researchers and pharmaceutical industries. CONCLUSIONS: It is crystal clear that marine organisms are a rich source of antiparasitic compounds, such as alkaloids, terpenoids, peptides, polyketides, terpene, coumarins, steroids, fatty acid derivatives, and lactones. The current and future technological innovation in natural products drug discovery will bolster the drug armamentarium for malaria and neglected tropical diseases.

Histone H1 defect in escort cells triggers germline tumor in Drosophila ovary.

Drosophila ovary is recognized as one of the best model systems to study stem cell biology in vivo. We had previously identified an autonomous role of the histone H1 in germline stem cell (GSC) maintenance. Here, we found that histone H1 depletion in escort cells (ECs) resulted in an increase of spectrosome-containing cells (SCCs), an ovary tumor-like phenotype. Further analysis showed that the Dpp pathway is excessively activated in these SCC cells, while the expression of bam is attenuated. In the H1-depleted ECs, both transposon activity and DNA damage had increased dramatically, followed by EC apoptosis, which is consistent with the role of H1 in other somatic cells. Surprisingly, H1-depleted ECs acquired cap cell characteristics including dpp expression, and the resulting abnormal Dpp level inhibits SCC further differentiation. Most interestingly, double knockdown of H1 and dpp in ECs can reduce the number of SCCs to the normal level, indicating that the additional Dpp secreted by ECs contributes to the germline tumor. Taken together, our findings indicate that histone H1 is an important epigenetic factor in controlling EC characteristics and a key suppressor of germline tumor.

Histone H1-mediated epigenetic regulation controls germline stem cell self-renewal by modulating H4K16 acetylation.

Epigenetics plays critical roles in controlling stem cell self-renewal and differentiation. Histone H1 is one of the most critical chromatin regulators, but its role in adult stem cell regulation remains unclear. Here we report that H1 is intrinsically required in the regulation of germline stem cells (GSCs) in the Drosophila ovary. The loss of H1 from GSCs causes their premature differentiation through activation of the key GSC differentiation factor bam. Interestingly, the acetylated H4 lysine 16 (H4K16ac) is selectively augmented in the H1-depleted GSCs. Furthermore, overexpression of mof reduces H1 association on chromatin. In contrast, the knocking down of mof significantly rescues the GSC loss phenotype. Taken together, these results suggest that H1 functions intrinsically to promote GSC self-renewal by antagonizing MOF function. Since H1 and H4K16 acetylation are highly conserved from fly to human, the findings from this study might be applicable to stem cells in other systems.