Diversity and geographical distribution of haptophyte Phaeocystis in the Chinese seas based on metabarcoding analysis

Phaeocystis is an important bloom-forming species and over 100 blooms have occurred since 1997 along the Chinese coasts,while only the species P.globosa was described.In this project,a total of 246 phytoplankton samples collected from the Bohai Sea,the Yellow Sea,and the East China Sea in April 2021 were analyzed to evaluate the species diversity and geographical distribution of the genus Phaeocystis based on metabarcoding 18S r DNA sequence.Four described Phaeocystis species were recognized,including P.globosa,P.pouchetii,P.jahnii,and P.cordata,and each has distinguished geographical distribution characteristics.P.globosa was the most widespread and abundant species,and P.pouchetii was found in the Bohai Sea and the northern Yellow Sea with substantially elevated abundance.P.cordata was also a widespread species,but its abundance was relatively low,while P.jahnii gathered only in the southeastern East China Sea.Water temperature,phosphate as well as ammonium contents were found to be associated with the abundance of P.globosa,P.pouchetii,and P.jahnii significantly.Moreover,two uncharacterized Phaeocystis species were detected in the Chinese seas,indicating the diversity of the genus remains underestimated worldwide.

Factors inducing morphological transition in harmful algal bloom-forming species Phaeocystis globosa with emphasis on predator chemical cue

The microalga Phaeocystis globosa is recognized as a harmful alga and also one of the few keystone phytoplankton genera that shape the structure and function of marine ecosystems.P.globosa possess a complex polymorphic life cycle,exhibiting phase alternation between free-living cells of approximately 3-6μm in diameter and gelatinous colonies(palmelloid stage)reaching several millimeters.The knowledge on the factors that induced the morphological transition of P.globosa in the last two decades was reviewed.Emphasis is given to infochemicals,an additional biological factor induced by predator,with the attempt to reveal a relevant mechanism of induced morphological defense.

Cell Size Dependent Responses of Phytoplankton Assemblages to Nitrate and Phosphate Additions in Surface Waters of the Northern South China Sea

Bioavailability of nitrogen (N) and phosphorus (P) is known to affect marine phytoplankton physiology, thus influencing their primary productivity;and it’s of general interest to see how the N or/and P additions affect the differently cell-sized phytoplankton assemblages. Data from the northern South China Sea showed that P addition increased up to 6 times of total chl a content within 24 h in the estuarine water;and N+P addition increased more than 20 times of chl a within 144 h in the pelagic water. The P addition powered 18.0% and 149% increase in the carbon fixation of larger (>3 μm) and smaller (

Research on the New Modern English Teaching Mode in Higher Vocational Colleges based on Multimedia and Interactive System

In this paper, we conduct research on the new modern English teaching mode in higher vocational colleges based on multimediaand interactive system. Multimedia can make the local conditions and customs of English-speaking countries, culture, art and life phenomenon,along with beautiful music and authentic English explanation, in order to real natural life scenes, abstract, boring of the learning content, becomevivid language communication environment, easy to stimulate students’ learning motivation, arouse their strong desire for knowledge, andthe thirst for knowledge into sustainable self-need, internalized learning motivation. Learning motivation is directly promote the inner power ofstudents in learning activities as point and level directly affect students’ learning behavior and academic achievement. Establishment situation,stimulate students’ curiosity and it is an effective way of training students’ learning motivations. This paper combines the related theories topropose the new perspective of the issues that will be meaningful.

A novel mesenchymal stem cell-based regimen for acute myeloid leukemia differentiation therapy

Currently the main treatment of acute myeloid leukemia(AML)is chemotherapy combining hematopoietic stem cell transplantation.However,the unbearable side effect of chemotherapy and the high risk of life-threatening infections and disease relapse following hematopoietic stem cell transplantation restrict its application in clinical practice.Thus,there is an urgent need to develop alternative therapeutic tactics with significant efficacy and attenuated adverse effects.Here,we revealed that umbilical cord-derived mesenchymal stem cells(UC-MSC)efficiently induced AML cell differentiation by shuttling the neutrophil elastase(NE)-packaged extracellular vesicles(EVs)into AML cells.Interestingly,the generation and release of NE-packaged EVs could be dramatically increased by vitamin D receptor(VDR)activation in UC-MSC.Chemical activation of VDR by using its agonist 1a,25-dihydroxyvitamin D3 efficiently enhanced the pro-differentiation capacity of UC-MSC and then alleviated malignant burden in AML mouse model.Based on these discoveries,to evade the risk of hypercalcemia,we synthetized and identified sw-22,a novel non-steroidal VDR agonist,which exerted a synergistic prodifferentiation function with UC-MSC on mitigating the progress of AML.Collectively,our findings provided a non-gene editing MSC-based therapeutic regimen to overcome the differentiation blockade in AML.

Crosstalk between IL-15Rα^(+)tumor-associated macrophages and breast cancer cells reduces CD8+T cell recruitment

Background:Interleukin-15(IL-15)is a promising immunotherapeutic agent owing to its powerful immune-activating effects.However,the clinical benefits of these treatments are limited.Crosstalk between tumor cells and immune cells plays an important role in immune escape and immunotherapy drug resistance.Herein,this study aimed to obtain in-depth understanding of crosstalk in the tumor microenvironment for providing potential therapeutic strategies to prevent tumor progression.Methods:T-cell killing assays and co-culture models were developed to determine the role of crosstalk between macrophages and tumor cells in breast cancer resistant to IL-15.Western blotting,histological analysis,CRISPR-Cas9 knockout,multi-parameter flow cytometry,and tumor cell-macrophage co-injection mouse models were developed to examine the mechanism by which IL-15Rα^(+)tumor-associated macrophages(TAMs)regulate breast cancer cell resistance to IL-15.Results:We found thatmacrophages contributed to the resistance of tumor cells to IL-15,and tumor cells induced macrophages to express high levels of theαsubunit of the IL-15 receptor(IL-15Rα).Further investigation showed that IL-15Rα^(+)TAMs reduced the protein levels of chemokine CX3C chemokine ligand 1(CX3CL1)in tumor cells to inhibit the recruitment of CD8^(+)T cells by releasing the IL-15/IL-15Rαcomplex(IL-15Rc).Administration of an IL-15Rc blocking peptide markedly suppressed breast tumor growth and overcame the resistance of cancer cells to anti-programmed cell death protein 1(PD-1)antibody immunotherapy.Interestingly,Granulocyte-macrophage colony-stimulating factor(GMCSF)inducedγchain(γc)expression to promote tumor cell-macrophage crosstalk,which facilitated tumor resistance to IL-15.Additionally,we observed that the non-transcriptional regulatory function of hypoxia inducible factor-1alpha(HIF-1α)was essential for IL-15Rc to regulateCX3CL1 expression in tumor cells.Conclusions:The IL-15Rc-HIF-1α-CX3CL1 signaling pathway serves as a crosstalk between macrophages and tumor cells in the tumormicroenvironment of breast cancer.Targeting this pathway may provide a potential therapeutic strategy for enhancing the efficacy of cancer immunotherapy.

Intervening pyruvate carboxylase stunts tumor growth by strengthening anti-tumor actions of tumor-associated macrophages

Dear Editor,Tumor-associated macrophages(TAMs)are critical pro-tumor immunocytes and depletion of TAMs has been exploited for cancer therapy.1 However,the phenotypes and functions of TAMs are plastic,TAMs can also be effector cells by engulfing tumor cells and recruiting cytotoxic T cells,thus shaping the actions of TAMs is more scientific rational than depleting them indiscriminately.2 To promote the entry of reorienting TAMs into the clinical treatments of tumors,it is essential to explore the underline mechanisms controlling the anti-and pro-tumor activities of TAMs.