Enzyme activity highlights the importance of the oxidative pentose phosphate pathway in lipid accumulation and growth of Phaeodactylum tricornutum under CO2 concentration

BACKGROUND: Rising CO(2) concentration was reported to increase phytoplankton growth rate as well as lipid productivity. This has raised questions regarding the NADPH supply for high lipid synthesis as well as rapid growth of algal cells. RESULTS: In this study, growth, lipid content, photosynthetic performance, the activity, and expression of key enzymes in Calvin cycle and oxidative pentose phosphate pathway (OPPP) were analyzed in the marine diatom Phaeodactylum tricornutum under three different CO(2) concentrations (low CO(2) (0.015 %), mid CO(2) (atmospheric, 0.035 %) and high CO(2) (0.15 %)). Both the growth rate and lipid content of P. tricornutum increased significantly under the high CO(2) concentration. Enzyme activity and mRNA expression of three Calvin cycle-related enzymes (Rubisco, 3-phosphoglyceric phosphokinase (PGK), phosphoribulokinase (PRK)) were also increased under high CO(2) cultivation, which suggested the enhancement of Calvin cycle activity. This may account for the observed rapid growth rate. In addition, high activity and mRNA expression of G6PDH and 6PGDH, which produce NADPH through OPPP, were observed in high CO(2) cultured cells. These results indicate OPPP was enhanced and might play an important role in lipid synthesis under high CO(2) concentration. CONCLUSIONS: The oxidative pentose phosphate pathway may participate in the lipid accumulation in rapid-growth P. tricornutum cells in high CO(2) concentration

Prognostic genes related to mitochondrial dynamics and mitophagy in diffuse large B-cell lymphoma are identified and validated using an integrated analysis of bulk and single-cell RNA sequencing

BackgroundWhile the link between mitochondrial homeostasis, specifically dynamics and mitophagy, and the progression of diffuse large B-cell lymphoma (DLBCL) has been suggested, their prognostic significance and functional networks remain unclear. This study aimed to investigate the role of mitochondrial dynamics-related genes (MDRGs) in DLBCL patient outcomes.MethodsCandidate MDGRs were identified via Weighted Gene Co-expression Network Analysis (WGCNA) and differential expression analysis using public RNA-seq data. A prognostic signature was established via LASSO-Cox regression, followed by proportional hazards assumption validation. Functional pathways, regulatory networks (including miR-1252-5p/NEAT1), and a risk-scoring model were analyzed. Model assessment included nomograms, immune cell infiltration, m6A regulator, and pharmacogenomics. Single-cell mapping was employed to characterize B-cell differentiation and spatial gene expression. Finally, the findings were validated using RT-qPCR on clinical samples.ResultsSix lysosomal-enriched genes (TCF7, CEBPA, BBC3, GALR3, BMP8B, and BAALC) were identified as independent prognostic indicators. A composite model integrating our risk score and clinical parameters showed superior predictive accuracy (AUC > 0.8). High-risk DLBCL was characterized by altered M0 macrophage infiltration, YTHDC1-mediated m6A dysregulation, and dihydrotestosterone sensitivity. Single-cell analysis revealed an association between stage-specific B-cell differentiation and gene expression gradients. RT-qPCR confirmed the upregulation of CEBPA, BBC3, GALR3, BMP8B, and BAALC in DLBCL clinical samples.ConclusionTCF7, CEBPA, BBC3, GALR3, BMP8B, and BAALC were identified as novel lysosomal pathway-enriched prognostic genes in DLBCL. Our validated composite model demonstrated strong predictive power. These findings establish an association between high-risk disease and specific tumor microenvironment alterations (M0 macrophages), epitranscriptomic dysregulation (m6A), and therapeutic vulnerabilities, providing valuable insights for refining prognosis and advancing targeted therapies for DLBCL

A Strategy for the Proliferation of Ulva prolifera, Main Causative Species of Green Tides, with Formation of Sporangia by Fragmentation

Ulva prolifera, a common green seaweed, is one of the causative species of green tides that occurred frequently along the shores of Qingdao in 2008 and had detrimental effects on the preparations for the 2008 Beijing Olympic Games sailing competition, since more than 30 percent of the area of the games was invaded. In view of the rapid accumulation of the vast biomass of floating U. prolifera in green tides, we investigated the formation of sporangia in disks of different diameters excised from U. prolifera, changes of the photosynthetic properties of cells during sporangia formation, and development of spores. The results suggested that disks less than 1.00 mm in diameter were optimal for the formation of sporangia, but there was a small amount of spore release in these. The highest percentage of area of spore release occurred in disks that were 2.50 mm in diameter. In contrast, sporangia were formed only at the cut edges of larger disks (3.00 mm, 3.50 mm, and 4.00 mm in diameter). Additionally, the majority of spores liberated from the disks appeared vigorous and developed successfully into new individuals. These results implied that fragments of the appropriate size from the U. prolifera thalli broken by a variety of factors via producing spores gave rise to the rapid proliferation of the seaweed under field conditions, which may be one of the most important factors to the rapid accumulation of the vast biomass of U. prolifera in the green tide that occurred in Qingdao, 2008

Natural Coevolution of Tumor and Immunoenvironment in Glioblastoma.

Isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM) has a dismal prognosis. A better understanding of tumor evolution holds the key to developing more effective treatment. Here we study GBM\u27s natural evolutionary trajectory by using rare multifocal samples. We sequenced 61,062 single cells from eight multifocal IDH wild-type primary GBMs and defined a natural evolution signature (NES) of the tumor. We show that the NES significantly associates with the activation of transcription factors that regulate brain development, including MYBL2 and FOSL2. Hypoxia is involved in inducing NES transition potentially via activation of the HIF1A-FOSL2 axis. High-NES tumor cells could recruit and polarize bone marrow-derived macrophages through activation of the FOSL2-ANXA1-FPR1/3 axis. These polarized macrophages can efficiently suppress T-cell activity and accelerate NES transition in tumor cells. Moreover, the polarized macrophages could upregulate CCL2 to induce tumor cell migration. SIGNIFICANCE: GBM progression could be induced by hypoxia via the HIF1A-FOSL2 axis. Tumor-derived ANXA1 is associated with recruitment and polarization of bone marrow-derived macrophages to suppress the immunoenvironment. The polarized macrophages promote tumor cell NES transition and migration. This article is highlighted in the In This Issue feature, p. 2711

Characteristics and phylogenetic analysis of the complete mitochondrial genome of Glyptothorax pallozonus (Siluriformes, Sisoridae)

Glyptothorax pallozonus Lin, 1934 is a small benthic fish belonging to the Sisoridae family that is distributed in the Dongjiang and Rongjiang Rivers of China. In the present study, we sequenced and characterized the complete mitochondrial genome of G. pallozonus for the first time. The complete mitogenome of G. pallozonus is 16,542 bp in length and includes 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNA (rRNAs), and a control region (CR). The mitogenome architecture was identical to that of other teleosts. Maximum likelihood (ML) phylogenetic analysis strongly supported the monophyly of Glyptothorax, which contains two clades. These results advance our understanding of the molecular phylogeny of the genus Glyptothorax

Single cell RNA-seq data and bulk gene profiles reveal a novel signature of disease progression in multiple myeloma

Abstract Background The development of multiple myeloma (MM) is considered to involve a multistep transformation process, but the role of cytogenetic abnormalities and molecular alterations in determining the cell fate of multiple myeloma (MM) remains unclear. Here, we have analyzed single cell RNA-seq data and bulk gene profiles to reveal a novel signature associated with MM development. Methods The scRNA-seq data from GSE118900 was used to profile the transcriptomes of cells from MM patients at different stages. Pseudotemporal ordering of the single cells was performed using Monocle package to feature distinct transcriptomic states of the developing MM cells. The bulk microarray profiles from GSE24080 and GSE9782 were applied to identify a signature associated with MM development. Results The 597 cells were divided into 7 clusters according to different risk levels. They were initiated mainly from monoclonal gammopathy of undetermined significance (MGUS), newly diagnosed MM (NDMM), or relapsed and/or refractory myeloma (RRMM) with cytogenetically favorable t(11;14), moved towards the cells from smoldering MM (SMM) or NDMM without t(11;14) or t(4;14), and then finally to cells from SMM or RRMM with t(4;14). Based on the markers identified in the late stage, the bulk data was used to develop a 20-gene signature stratifying patients into high and low-risk groups (GSE24080: HR = 3.759, 95% CI 2.746–5.145; GSE9782: HR = 2.612, 95% CI 1.894–3.603), which was better than the previously published gene signatures (EMC92, UAMS70, and UAMS17) and International Staging System. This signature also succeeded in predicting the clinical outcome of patients treated with bortezomib (HR = 2.884, 95% CI 1.994–4.172, P = 1.89e−8). The 20 genes were further verified by quantitative real-time polymerase chain reaction using samples obtained from the patients with MM. Conclusion Our comprehensive analyses offered new insights in MM development, and established a 20-gene signature as an independent biomarker for MM. </jats:sec