Biology subjects

Mai, C.

Publications and source records attributed to Mai, C..

3 recordsLinked to original sources

bioRxiv2024

SIRPalpha+ PD-L1+ bone marrow macrophages aid AML growth by modulating T cell function

Acute myeloid leukemia (AML) continues to have a poor prognosis due to its ability to relapse following initial response to chemotherapy. While immunotherapies hold the promise to revolutionize cancer treatment, AML has been particularly challenging to target. It is therefore important to better understand the relationship between AML cells and immune cells within the bone marrow (BM) microenvironment, where this disease grows. Here we focus on non-malignant BM macrophages, and using a combination of intravital microscopy, flow cytometry, transcriptomics and functional analyses we identify a subpopulation of immunomodulatory BM macrophages (IMMs) with a unique profile and function during AML progression. While the majority of macrophages are already being lost at early infiltration, IMMs are locally enriched. They are capable of efferocytosis and support AML growth through inhibition of T cells. Enrichment of IMMs in the BM of patients developing early relapse indicates that future development of interventions that target IMMs development and function may improve AML patients outcome.

cancer biology↗

bioRxiv2024

Soybean PHR1-regulated low phosphorus-responsive GmRALF22 increases uptake of phosphate via stimulating GmPTs expression

Phosphorus (P) is one of essential macronutrients for plant growth and development. Rapid Alkalization Factors (RALFs) play crucial roles in plant responses to nutrient stresses, however, the functions of Glycine max RALFs (GmRALFs) under low P (LP) stress remain elusive. In this study, we first identified 27 GmRALFs in soybean, then we revealed that GmRALF10, GmRALF11, and GmRALF22 are induced in both roots and leaves, while only GmRALF5, GmRALF6, and GmRALF25 are up-regulated in leaves in LP conditions. Furthermore, GmRALF22 was found to be the target gene of transcription factor GmPHR1, which binds the P1BS cis-element in the promoter of GmRALF22 via electrophoretic mobility shift assay (EMSA) and DUAL-LUC experiment. Colonization of Bacillus subtilis that deliver GmRALF22 increases the expression of high affinity phosphate (Pi) transporter gene GmPT2, GmPT11, GmPT13 and GmPT14, thus increases the total amount of dry matter and soluble Pi in soybean. RNA-sequencing uncovered that GmRALF22 alleviates LP stress by regulating the expression of JA-, SA- and immune-related genes. Finally, we verified that GmRALF22 is dependent on FERONIA to promote Arabidopsis primary root growth under LP conditions. In summary, GmPHR1-GmRALF22 module positively regulates soybeans tolerance to LP. HighlightsO_LISoybean genome has 27 GmRALFs. GmRALF5, GmRALF6, GmRALF10, GmRALF11, GmRALF22 and GmRALF25 are induced in low phosphorus (LP). C_LIO_LIGmPHR1 directly regulate the transcription of GmRALF22 via binding the promoter P1BS cis-element. C_LIO_LISecretion of GmRALF22 protein by Bacillus subtilis promoted soybean growth under LP conditions by improving soybean P nutrition through increased expression of high affinity phosphate (Pi) transporter gene. C_LIO_LIGmRALF22 regulates soybean P nutrition by JA-, SA- and immune-related genes expression at transcriptome level. That application of GmRALF22 promoted primary root growth in Arabidopsis in LP is dependent on FER receptor. C_LI

molecular biology↗

bioRxiv2023

Arabidopsis Transcription Factor WRKY45 Confers Cadmium Tolerance via Activating PCS1 and PCS2 Expression

Cadmium (Cd) has long been recognized as toxic pollutant to crops worldwide. The biosynthesis of glutathione-dependent phytochelatin plays crucial roles in the detoxification of Cd in plants. However, its regulatory mechanism remains elusive. Here, we revealed that Arabidopsis transcription factor WRKY45 confers Cd tolerance via promoting the expression of PC synthesis-related genes PCS1 and PCS2, respectively. Firstly, we found that Cd stress induces the transcript levels of WRKY45 and its protein abundance. Accordingly, in contrast to wild type Col-0, the increased sensitivity to Cd is observed in wrky45 mutant, while overexpressing WRKY45 plants are more tolerant to Cd. Secondly, quantitative real-time PCR revealed that the expression of AtPCS1 and AtPCS2 is stimulated in overexpressing WRKY45 plants, but decreased in wrky45 mutant. Thirdly, WRKY45 promotes the expression of PCS1 and PCS2, electrophoresis mobility shift assay analysis uncovered that WRKY45 directly bind to the W-box cis-element of PCS2 promoter. Lastly, the overexpression of WRKY45 in Col-0 leads to more accumulation of PCs in Arabidopsis, and the overexpression of PCS1 or PCS2 in wrky45 mutant plants rescues the phenotypes induced by Cd stress. In conclusion, our results show that AtWRKY45 positively regulate Cd tolerance in Arabidopsis via activating PCS1 and PCS2 expression. Environmental implicationAccumulation of cadmium (Cd) in soils poses a threat to crop productivity and food safety. It has been revealed that phytochelatin (PC) plays an essential role in plants to alleviate Cd toxicity, yet the regulatory mechanisms governing its expression remain unclear. We have demonstrated that the Arabidopsis transcription factor WRKY45 directly activates the expression of PCS1 and PCS2, which encode PC synthase, thereby increasing the content of PC and enhancing Arabidopsis tolerance to Cd stress. These findings offer insights into precise regulation strategies for crop Cd tolerance via modulation of WRKY45 homologue in crops.

molecular biology↗