Genomics, Proteomics & Bioinformatics•2024•DOI: 10.1093/gpbjnl/qzad002
The order Acipenseriformes, which includes sturgeons and paddlefishes, represents “living fossils” with complex genomes that are good models for understanding whole-genome duplication (WGD) and ploidy evolution in fishes. Here, we sequenced and assembled the first high-quality chromosome-level genome for the complex octoploid Acipenser sinensis (Chinese sturgeon), a critically endangered species that also represents a poorly understood ploidy group in Acipenseriformes. Our results show that A. sinensis is a complex autooctoploid species containing four kinds of octovalents (8n), a hexavalent (6n), two tetravalents (4n), and a divalent (2n). An analysis taking into account delayed rediploidization reveals that the octoploid genome composition of Chinese sturgeon results from two rounds of homologous WGDs, and further provides insights into the timing of its ploidy evolution. This study provides the first octoploid genome resource of Acipenseriformes for understanding ploidy compositions and evolutionary trajectories of polyploid fishes.
Stem Cell Research & Therapy•2025•DOI: 10.1186/s13287-025-04154-3
Background Myelodysplastic syndrome (MDS) is a clonal disorder of hematopoietic stem cells (HSCs), characterized by ineffective hematopoiesis and a high risk of progression to acute myeloid leukemia. Elucidating the mechanism underlying the dysfunction of MDS-HSCs is crucial for exploring the pathogenesis of the syndrome. While previous studies have implicated mesenchymal stem cells (MSCs), a principal component of the bone marrow (BM) microenvironment, in the inhibition of normal hematopoiesis, the precise molecular mechanisms have not been fully elucidated. In this study, we investigated the effects of MSCs from MDS patients on hematopoietic functions of HSCs from a metabolic perspective. Methods MSCs were isolated from BM of MDS patients. The proliferation, apoptosis, differentiation and support for hematopoiesis of these cells were analyzed using CCK-8 assay, FC and induction medium and CFU (colony forming units) assay, respectively. Expression levels of metabolic molecules were used as indicators to screen MSCs with different metabolic pathways and were detected by RT-PCR and Western blotting. Exosome derived from MSCs were isolated from the culture supernatant and confirmed by Transmission Electron Microscope, Dynamic Light Scattering and Western blotting. The effects of these exosomes on HSCs were analyzed using the same methods as those used to assess MSCs function. Results Our findings demonstrated that MDS-MSCs exhibited significant functional impairments, including reduced proliferation, impaired differentiation, diminished support for hematopoiesis, and increased apoptosis. Notably, we observed an upregulation of lipid metabolism in these MSCs, which appears to contribute to their dysfunction. Intriguingly, the aberrant lipid metabolic profile can be effectively reversed by the administration of etomoxir (ETO), an inhibitor of carnitine palmitoyltransferase 1A (CPT-1A). Furthermore, MSCs with enhanced lipid metabolism could transmit this dysfunction to HSCs through the secretion of exosomes that are enriched in CPT-1A. Conclusions We suggest that the MDS BM microenvironment disrupts MSCs metabolism by increasing the expression of CPT-1A, which impairs the ability to support normal HSCs. Interestingly, the suppressive effect is mediated by exosomes rich in CPT-1A, which derived from MSCs. These findings provide novel insights into MDS MSCs-metabolism-Exosome axis in ineffective hematopoiesis and offer new strategies for the treatment of MDS.
Stem Cell Research & Therapy•2025•DOI: 10.1186/s13287-025-04525-w
Background Mesenchymal stem cells (MSCs) are widely used in treating autoimmune diseases. However, replicative senescence limits the quantity and quality of MSCs during population doublings in vitro. Transcription factor SOX4 is a crucial regulator of cell fate and stemness. This study aims to explore the role of SOX4 in senescence of MSCs and enhance their therapeutic efficacy in systemic lupus erythematosus (SLE). Methods In early-passage MSCs (P3), late-passage MSCs (P8), SOX4 downregulated P3-MSCs or SOX4 overexpressed P8-MSCs, cell morphology, mitochondrial reactive oxygen species (mtROS), senescence-associated β-galactosidase (SA-β-Gal) activity, cell proliferation rate, senescence-associated secretory phenotype (SASP) factors, cell cycle suppressors, the immunosuppressive effects on T cell activation and proliferation and the expression levels of SOX4 were determined. Imiquimod induced SLE mice were transplanted with P3-MSCs and P8-MSCs or control and SOX4 overexpressed P8-MSCs, and clinical symptoms were assessed. Results Compared to P3-MSCs, P8-MSCs display a senescent phenotype, increased mtROS, SA-β-Gal activity, SASP factors, and cell cycle suppressors p53, p21, and p16. Additionally, P8-MSCs have a reduced immunosuppressive function on T cell activation and proliferation, and express lower levels of SOX4. Downregulation of SOX4 in P3-MSCs promotes cellular senescence and impairs their immunosuppressive function. Conversely, overexpression of SOX4 in P8-MSCs ameliorates cellular senescence and enhances their immunosuppressive function. Furthermore, transplantation of P3-MSCs or SOX4-overexpressing P8-MSCs demonstrates greater therapeutic significantly efficacy in SLE mice compared to P8-MSCs.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025019
Cancer cells evade immune detection through checkpoint molecules like PD-L1 and PD-L2 which suppress T-cell activation. While PD-L1 is well-studied, the role of PD-L2 remains unclear. Pyruvate kinase M2 (PKM2), a metabolic enzyme, influences immune checkpoint regulation, but its role in PD-L1 and PD-L2 modulation is not well defined. Here, we investigate the role of pyruvate kinase M2 (PKM2) in modulating the immune checkpoint molecules PD-L1 and PD-L2 via GATA3 in cancer cells, with insights from both human and mouse models. We find that PKM2 enhances PD-L1 expression while inhibiting PD-L2, a dual regulatory mechanism that facilitates immune evasion. Knockdown and overexpression experiments revealed GATA3 as a key mediator. PKM2 knockout reduced GATA3 level, leading to decreased PD-L1 and increased PD-L2 expression. Chromatin immunoprecipitation (ChIP)-qPCR demonstrates that GATA3 functions as a direct transcription factor capable of binding to the promoters of PD-L1 and PD-L2. In silico analyses of 81 esophageal squamous cell carcinoma (ESCC) cases from the TCGA database demonstrate that PKM2 mRNA is unrelated to PD-L1 and PD-L2 expression but is negatively correlated with CD8+ T-cell infiltration in ESCC. To further validate these findings, we establish a xenograft model using immune-competent C57/BL6N mice, where knockdown of PKM2 results in significant downregulation of both PD-L1 and PD-L2 expression. Collectively, these findings underscore the divergent roles of PKM2 in regulating immune checkpoint expression in human and mouse cancer models and suggest that targeting the PKM2-GATA3 axis could enhance cancer immunotherapy by fine-tuning PD-L1 and PD-L2 levels.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21409
BACKGROUND: Conventional rectangular targeting devices are divided into two modules, one left and one right, which hinders flexible intraoperative use and is prone to deformation and error. Even after connection, repeated fluoroscopic confirmation is still required for screw drilling and placement. OBJECTIVE: To investigate the key technology development and clinical application of a modified rectangular locking device for precise distal locking screw placement in intramedullary nailing of femoral shaft fractures. METHODS: Medical records of patients with femoral shaft fractures admitted to Affiliated Suqian Hospital of Xuzhou Medical University and Suyu District People's Hospital from 2021 to 2023 were collected. Patients aged 18-65 years, diagnosed with femoral shaft fractures (AO classification: A, B, or C) by radiographic examination, who underwent closed reduction and intramedullary nailing with distal locking screw placement using the modified rectangular locking device, and whose clinical data (including medical history, radiographic findings, surgical records, and follow-up records) were selected. Forty-one cases met the criteria, including 30 males and 11 females, aged 20-62 years, with an average age of (41.17±8.14) years. Intraoperative fluoroscopy times, locking success rate, time for successful distal locking screw placement, American Knee Society Score at 1 month postoperatively and after fracture healing, and fracture healing time were collected. RESULTS AND CONCLUSION: (1) All 41 patients underwent distal locking screw placement using the modified rectangular locking device. Intraoperative fluoroscopy times ranged from 0 to 2 times, with an average of (1.1±0.5) times; the locking success rate was 98%; the time for successful distal locking screw placement ranged from 6 to 10 minutes, with an average of (7.0±1.5) minutes; the American Knee Society Score at 1 month postoperatively ranged from 140 to 190, with an average of (150±15) points. (2) Thirty-eight patients were followed up completely for 12-24 months. Fracture healing time ranged from 9 to 14 months, with an average of (10.5±2.5) months. After fracture healing, the American Knee Society Score ranged from 150 to 190, with an average of (185±8) points, with 35 excellent and 3 good results. (3) The results indicate that compared with freehand locking, oblique fluoroscopic placement, arthroscopic-assisted placement, and electromagnetic navigation locking of distal locking screws, the modified rectangular locking device offers advantages including no dependence on arthroscopic or electromagnetic navigation equipment, no requirement for extensive surgical experience, simple steps, accurate locking, high repeatability, and reduced radiation exposure.
Acta Biochimica et Biophysica Sinica•2026•DOI: 10.3724/abbs.2026020
The insulin receptor (IR) is central to the regulation of glucose and lipid metabolism. Although insulin is its primary ligand, insulin-like growth factors I and II (IGF-I and IGF-II) also engage IR, albeit with reduced affinity. The structural basis of cooperative ligand binding, however, has remained poorly understood. Here, we report cryo-Electron Microscopy (cryo-EM) structures of IR in complex with insulin, IGF-I, and IGF-II, revealing that all three ligands engage the receptor at overlapping binding sites and can induce a conserved T-shaped quaternary assembly involving four ligand molecules at site 1/1′ and site 2/2′. Despite this shared overall architecture, distinct ligand-specific conformational changes are observed. Notably, IGF-I and IGF-II adopt different binding sequence at site 1 and site 2 compared to insulin, suggesting unique interaction dynamics. These structural insights highlight divergent mechanisms of ligand recognition and cooperative binding, providing a deeper understanding of hormone-induced conformational modulation of the IR.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025019
Cancer cells evade immune detection through checkpoint molecules PD-L1 and PD-L2, which suppress T-cell activation. While PD-L1 is well-studied, the role of PD-L2 remains unclear. Pyruvate kinase M2 (PKM2), a metabolic enzyme, influences immune checkpoint regulation, but its role in PD-L1 and PD-L2 modulation is not well defined. Here, we investigate the role of PKM2 in modulating PD-L1 and PD-L2 via GATA3 in cancer cells, with insights from both human and mouse models. We find that PKM2 enhances PD-L1 expression while inhibiting PD-L2, a dual regulatory mechanism that facilitates immune evasion. Knockdown and overexpression experiments revealed GATA3 as a key mediator. PKM2 knockout reduced GATA3 level, leading to decreased PD-L1 and increased PD-L2 expression. Chromatin immunoprecipitation (ChIP)-qPCR demonstrates that GATA3 functions as a direct transcription factor capable of binding to the promoters of PD-L1 and PD-L2. In silico analyses of 81 esophageal squamous cell carcinoma (ESCC) cases from the TCGA database demonstrate that PKM2 mRNA is unrelated to PD-L1 and PD-L2 expression but is negatively correlated with CD8+ T-cell infiltration in ESCC. To further validate these findings, we establish a xenograft model using immune-competent C57/BL6N mice, where knockdown of PKM2 results in significant downregulation of both PD-L1 and PD-L2 expression. Collectively, these findings underscore the divergent roles of PKM2 in regulating immune checkpoint expression in human and mouse cancer models and suggest that targeting the PKM2-GATA3 axis could enhance cancer immunotherapy by fine-tuning PD-L1 and PD-L2 levels.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025143
Vascular calcification (VC) is an independent risk factor for cardiovascular morbidity and mortality, characterized by hydroxyapatite deposition in arterial walls, leading to increased stiffness, decreased compliance, and plaque rupture. No clinically acknowledged therapy reverses VC. Dihydrocapsaicin (DHC), the primary pungent capsaicinoid in chili peppers, exhibits analgesic, anticancer, anti-inflammatory, antioxidant, and anti-obesity properties. Using the Comparative Toxicogenomics Database, we identified 20 experimental target genes of DHC, including ATF4, CASP3, CASP4, CASP7, CAT, CDKN1A, CYP1A2, CYP2C19, CYP2C9, CYP2D6, CYP2E1, DDIT3, EIF2S1, ERN1, HSPA5, IGF1, MAP1LC3A, MAPK1, MAPK3, and TP53. Chemical-phenotype analysis revealed associations with apoptotic processes and autophagy. In a human vascular smooth muscle cell (hVSMC) calcification model induced by 1.2 μL of 100 mM CaCl2 in α-MEM basal medium, co-treatment with DHC (0.5, 2, or 8 μL of 4 mM solution) for 3–6 h significantly inhibited calcium deposition, as quantified by Alizarin Red staining and ImageJ analysis. These findings suggest that DHC modulates VC through mechanisms involving cell death, endoplasmic reticulum stress, and calcium signaling, highlighting its potential as a therapeutic agent for VC.