Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025014
Ferroptosis is a novel form of regulated cell death characterized by the iron-dependent accumulation of lipid peroxides. Recent research has suggested that ferroptosis in osteoblasts contributes to steroid-induced osteonecrosis of the femoral head (SONFH). However, the relationship between ferroptosis and SONFH remains unclear. In this study, in vitro experiments show that dexamethasone (Dex) treatment reduces the expressions of key ferroptosis regulators, SLC7A11 and GPX4, in MC3T3-E1 cells. This reduction leads to a decrease in intracellular glutathione (GSH) levels, accompanied by elevated levels of total iron, malondialdehyde (MDA), and reactive oxygen species (ROS). Importantly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively reverses Dex-induced ferroptosis in MC3T3-E1 cells. Furthermore, RNA-seq analysis reveals that the long noncoding RNA (lncRNA) XR_877193.1 is significantly upregulated in Dex-treated MC3T3-E1 cells. Functional studies demonstrate that the knockdown of lncRNA XR_877193.1 promotes osteogenic differentiation by inhibiting Dex-induced ferroptosis in MC3T3-E1 cells, whereas its overexpression exacerbates cell death via ferroptosis. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis reveals that the differentially expressed lncRNA XR_877193.1 is enriched in ferroptosis-related pathways, including the PI3K/AKT signaling pathway. Moreover, PI3K/AKT inhibitors reverse ferroptosis in MC3T3-E1 cells inhibited by lncRNA XR_877193.1 knockdown. Collectively, our findings indicate that lncRNA XR_877193.1 knockdown exerts anti-ferroptosis effects by stimulating the PI3K/AKT signaling pathway, suggesting a promising therapeutic strategy for attenuating SONFH.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024084
Osteosarcoma (OS) is a primary bone cancer mostly found in adolescents and elderly individuals. The treatment of OS is still largely dependent on traditional chemotherapy. However, the high incidence of drug resistance remains one of the greatest impediments to limiting improvements in OS treatment. Recent findings have indicated that the transcription factor FOXM1 plays an important role in various cancer-related events, especially drug resistance. However, the possible role of FOXM1 in the resistance of OS to methotrexate (MTX) remains to be explored. Here, we find that FOXM1, which confers resistance to MTX, is highly expressed in OS tissues and MTX-resistant cells. FOXM1 overexpression promotes MTX resistance by enhancing autophagy in an HMMR/ATG7-dependent manner. Importantly, silencing of FOXM1 or inhibiting autophagy reverses drug resistance. These findings demonstrate a new mechanism for FOXM1-induced MTX resistance and provide a promising target for improving OS chemotherapy outcomes.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025065
Stem cell fate is profoundly influenced by a complex interplay of biochemical and biophysical cues, with the latter increasingly recognized for its roles in cellular processes, yet the mechanisms are unclear. Since chromatin accessibility is a critical determinant in the processes of osteogenesis and bone repair, investigating the contributions of open chromatin regions (OCRs) to the intracellular signaling pathways triggered by topographical cues, which lead to osteogenic differentiation is highly valuable. This study explores the impact of the nanotopography of biomaterials on the osteogenic differentiation of human bone marrow stem cells (hBMSCs). By utilizing electrospun poly-L-lactide (PLLA) membranes with random fiber arrangements, we mimic the natural extracellular matrix (ECM) topography to study its effects on hBMSCs, contrasting them with flat PLLA controls. Through high-throughput Assay for Transposase-Accessible Chromatin with sequencing (ATAC-seq) and RNA sequencing (RNA-seq), we reveal that the nanotopography of electrospun surfaces promotes osteogenic differentiation by modulating the chromatin accessibility of the YBX1 gene promoter, leading to its upregulation. Lentiviral knockdown experiments further confirm the crucial role of YBX1, revealing a reversal of the osteogenic effects induced by nanotopography. This study emphasizes the importance of YBX1 in the osteogenic response to the surface topography of biomaterials and suggests that nanotopographical cues could be harnessed to direct stem cell fate. These findings are important for developing biomaterials that promote specific stem cell outcomes in regenerative medicine. Our results further contribute to a deeper understanding of the mechanisms underlying stem cell differentiation in response to environmental cues and pave the way for the rational design of biomaterials with enhanced osteogenic potential. By elucidating the role of chromatin accessibility and specific transcription factors such as YBX1, this study highlights the intricate interplay between cell-material interactions and the intracellular signaling pathways that govern stem cell fate.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024077
Epigenetic modifications play an important role in cellular senescence, and enhancer of zeste homolog 2 (EZH2) is a key methyltransferase involved in epigenetic remodeling in multiple myeloma (MM) cells. We have previously demonstrated that GSK126, a specific EZH2 inhibitor, exhibits anti-MM therapeutic efficacy and safety in vivo and in vitro; however, its specific mechanism remains unclear. This study shows that GSK126 induces cellular senescence in MM, which is characterized by the accumulation of senescence-associated heterochromatin foci (SAHF) and p21, and increased senescence-associated β galactosidase activity. Furthermore, EZH2 is inhibited in ribonucleotide reductase regulatory subunit M2 (RRM2)-overexpressing OCI-MY5 and RPMI-8226 cells. RRM2 overexpression inhibits the methyltransferase function of EZH2 and promotes its degradation through the ubiquitin-proteasome pathway, thereby inducing cellular senescence. In this senescence model, Lamin B1, a key component of the nuclear envelope and a marker of senescence, does not decrease but instead undergoes aberrant accumulation. Meanwhile, phosphorylation of extracellular signal-regulated protein kinase (ERK1/2) is significantly increased. The inhibition of ERK1/2 phosphorylation in turn partially restores Lamin B1 level and alleviates senescence. These findings suggest that EZH2 inhibition increases Lamin B1 level and induces senescence by promoting ERK1/2 phosphorylation. These data indicate that EZH2 plays an important role in MM cellular senescence and provide insights into the relationships among Lamin B1, p-ERK1/2, and cellular senescence.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024096
Autophagy is a cellular mechanism for self-renewal that involves the breakdown of cytoplasmic proteins or organelles within lysosomes. Although preeclampsia (PE) exhibits several characteristics that could imply disrupted autophagy, there is limited evidence supporting the notion that impaired placental autophagy directly causes PE, as indicated by differential expression profiling of whole placental tissue. In this study, we aim to explore the significance of autophagy in maintaining pregnancy and its association with PE. First, the RNA-seq results show that 218 genes are differentially expressed in placentas from preeclamptic pregnancies. Notably, KEGG pathway analysis reveals significant enrichment of genes related to autophagy-related signaling pathways, including the PI3K-Akt signaling pathway, the AMPK signaling pathway, and the mTOR signaling pathway. Additionally, our findings indicate an increase in autophagy in placentas from pregnancies complicated by preeclampsia as well as in trophoblasts subjected to hypoxic conditions. Next, we examine the impact of 3-methyladenine (3-MA), a targeted inhibitor of autophagy, on the progression of PE. The administration of 3-MA profoundly alleviates the severity of PE-like symptoms in rats subjected to reduced uterine perfusion pressure (RUPP). The findings from our study suggest that inhibiting autophagy may serve as a promising approach for adjuvant chemotherapy for PE.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024140
There are three isoforms of human collagen prolyl 4-hydroxylases (C-P4Hs), each of which has been reported to play an important role in regulating the progression of a variety of human cancers. By analyzing TGCA datasets on human head and neck squamous cell carcinoma (HNSC), we find that a higher expression of all three C-P4HAs (the α subunit of C-P4Hs) is a superior prognostic indicator than a higher expression of two or a single C-P4HA. Unexpectedly, some patients with higher levels of three C-P4HAs survive longer than patients whose tumors have lower expression of C-P4HAs. Therefore, there may be molecule(s) that can negate the deleterious effects of overexpressing C-P4HAs during cancer progression. By constructing a functional protein interaction network of C-P4HAs and analyzing molecules whose expressions are correlated significantly with that of C-P4HAs, we identify scribble cell polarity complex component 2 (LLGL2) as a factor that antagonizes the effects of overexpressed C-P4HAs on HNSC. Silencing of LLGL2 in the human oral squamous cell line Cal-27 upregulates the expression of occludin and increases cancer cell invasion and migration. In contrast, knocking down C-P4HA alone inhibits cell migration and invasion. Furthermore, simultaneously downregulating three C-P4HAs has more pronounced effects on inhibiting cell migration and invasion. Accordingly, high LLGL2 expression is also a marker indicating improved prognosis in patients with HNSC. These results suggest that the interplay between LLGL2 and C-P4HAs may be targeted to mitigate HNSC tumorigenesis and progression.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024203
Increased glycolytic metabolism is a key step in the reproduction of Brucella and the induction of brucellosis, however, little is known about how this process is regulated during infection. Forkhead box protein O1 (FOXO1) is a transcription factor that regulates energy metabolism. In this study, we employ the yeast two-hybrid system (Y2H) and immunoprecipitation (Co-IP) to reverse screen for the FOXO1 for the first time and identify interactions between FOXO1 and the Brucella secretory protein VceA. Our findings reveal that the Brucella secretory protein VceA colocalizes with FOXO1 in the cytoplasm. Additionally, we observe that infection of macrophages with Brucella abortus 2308 (S2308) promotes FOXO1 entry into the nucleus, leading to a significant upregulation of glycolysis level in macrophage. Conversely, in a VceA mutant strain (S2308-ΔVceA), we note a significant reduction in the ability of FOXO1 to enter the nucleus, accompanied by a decrease in glycolysis level. Furthermore, Brucella interacts with FOXO1 through the secreted protein VceA, promoting the entry of FOXO1 into the nucleus and thereby altering host metabolic patterns. This study provides insights into the mechanisms by which Brucella invades host macrophages and induces unique metabolic changes. These insights may offer a novel rationale for developing metabolic therapeutic strategies for the treatment and prevention of related diseases.
Acta Biochimica et Biophysica Sinica•2024•DOI: 10.3724/abbs.2024188
DNA replication stress is a significant contributor to spontaneous DNA damage and genome instability. While the impact of p53 deficiency on increasing DNA replication stress is known, the specific molecular mechanism underlying this phenomenon remains poorly understood. This study explores how p53 deficiency induces DNA replication stress by activating mTORC1 through R-loop formation, which is facilitated by the upregulation of RNR. Research has shown that p53 deficiency results in increased γH2AX expression and a higher mutation rate in the HPRT gene. Interestingly, these effects can be alleviated by rapamycin, an mTORC1 inhibitor. Additionally, rapamycin reduces the abundance of R-loop structures in p53KO cells, which is linked to mTORC1’s regulation of ribonucleotide reductase (RNR) level. These findings suggest that p53 deficiency-induced DNA replication stress relies on mTORC1 activation, with the upregulation of RNR expression and R-loop formation. Overall, this study underscores the importance of R-loops in mTORC1 activation-dependent DNA replication stress triggered by p53 deficiency.
Chinese Journal of Pathophysiology•2025•DOI: 10.3969/j.issn.1000-4718.2025.06.001
AIM: Regulatory T cells (Tregs) are a specialized subset of CD4+ T cells primarily involved in immunosuppressive functions. AMP-activated protein kinase (AMPK) serves as a metabolic sensor that governs the differentiation, maturation, and immune functions of Tregs through metabolic reprogramming. However, the impact of AMPKα1 (the catalytic subunit of AMPK) knockout specifically in Tregs on the host's immune microenvironment remains largely unexplored. METHODS: Histological changes in immune organs were assessed using HE staining. The types of immune cells and their relative population percentages in immune organs and blood were quantified through flow cytometry in both AMPKα1flox/flox (AMPKα1fl/fl) mice and Treg-specific AMPKα1 knockout mice (AMPKα1fl/flFoxp3cre mice). RESULTS: Compared to AMPKα1fl/fl mice, the percentage of eosinophils in the bone marrow of AMPKα1fl/flFoxp3cre mice was significantly reduced. Additionally, while the thymus of AMPKα1fl/flFoxp3cre mice exhibited normal structure, both its size and the ratio of thymus weight to body weight were significantly decreased. The knockout of AMPKα1 in Tregs led to a notable reduction in the total percentage of immature double-negative (DN) cells. Consequently, the percentage of CD4+ T cells derived from these DN cells also decreased, even though the percentages of DN1 and DN4 cells were higher in the thymus of AMPKα1fl/flFoxp3cre mice compared to AMPKα1fl/fl mice. Importantly, the proportion of Siglec-F+ CD11b+ eosinophils in the thymus was significantly lower in AMPKα1fl/flFoxp3cre mice. Knockout of AMPKα1 in Tregs resulted in a marked increase in the percentage of CD4+ T cells in peripheral blood, alongside a decrease in the proportion of mature CD8+ T cells. Similarly, the proportion of CD4+ T cells in the spleen of AMPKα1fl/flFoxp3cre mice was elevated compared to AMPKα1fl/fl mice. In contrast, the proportion of neutrophils significantly decreased, while mononuclear cell proportions increased in the spleen of AMPKα1fl/flFoxp3cre mice. In lymph nodes, the medullary boundaries in AMPKα1fl/flFoxp3cre mice were blurred, and the lymphoid follicles were missing, a feature not observed in AMPKα1fl/fl mice. Furthermore, the knockout of AMPKα1 in Tregs reduced the CD3+ T cell population, particularly the CD8+ T cell population, in lymph nodes. Although the mature Treg cell population was significantly lower in AMPKα1fl/flFoxp3cre mice, the percentage of CD4+ T cells was markedly increased. In contrast, there was no statistically significant difference in granulocyte populations between AMPKα1fl/flFoxp3cre and AMPKα1fl/fl mice. CONCLUSION: The populations of mature Tregs, CD8+ T cells and eosinophils in various immune organs were significantly altered in mice with Treg-specific AMPKα1 knockout, suggesting a potential remodeling of the host immune microenvironment in response to inflammatory stimuli.
Chinese Traditional and Herbal Drugs•2026•DOI: 10.7501/j.issn.0253-2670.2026.16.20261623
Endophytic bacterial communities associated with the medicinal plant Duchesnea indica were profiled across root, stem, leaf, and fruit tissues using Illumina paired-end high-throughput sequencing. A total of 1,914,360 raw sequences were generated and processed via DADA2 and Vsearch pipelines. At the phylum level, Proteobacteria dominated all tissues. Tissue-specific variation was pronounced: the stem harbored the highest richness, whereas the root exhibited the highest diversity. Sphingomonas was identified as a key biomarker discriminating intergroup differences and displayed a significant positive correlation with Pseudomonas. Both genera were principal contributors to the N10-formyltetrahydrofolate biosynthesis pathway. Leaf, fruit, and stem communities clustered with high similarity, while root communities were distinctly separated. Functional prediction indicated that Pseudomonas and Sphingomonas may act synergistically in secondary metabolite synthesis or host stress resistance. These findings establish a microbiological basis for the pharmacological activity of D. indica and suggest that endophytic community modulation could enhance the accumulation of bioactive flavonoids, triterpenoids, and polyphenols, offering a novel avenue for the sustainable development of traditional Chinese medicine resources.
Acta Hydrobiologica Sinica•2026•DOI: 10.3724/1000-3207.2026.2026.0101
High-density crowding stress during the initial feeding stage poses severe challenges to fish health, promoting lipid peroxidation. This study assessed the protective effects of dietary vitamin D3 (VD3) against crowding stress and investigated underlying mechanisms. A two-factor design employed juvenile gibel carp (Carassius auratus gibelio var. CAS V) (0.47±0.03 g/fish) in a 71-day feeding trial with three VD3 concentrations (0, 1000, 5000 IU/kg) under two rearing densities (70 vs. 210 fish/tank). Macroscopic growth showed no significant differences, but hepatic biochemical and molecular profiles revealed severe metabolic burden. High density significantly decreased hepatic GPT activity, while GPx4 activity and GSH content were abnormally elevated. Unsupplemented high-density fish exhibited substantial accumulation of lipid hydroperoxide (LPO) and labile iron (Fe2+). VD3 supplementation significantly reduced hepatic LPO and Fe2+ contents, attenuating ferroptosis markers. Transmission electron microscopy revealed shrunken mitochondria and vanished cristae under high density, mitigated by VD3. Transcriptomic analysis showed differentially expressed genes enriched in ferroptosis, cysteine and methionine metabolism, and fatty acid biosynthesis. qPCR confirmed upregulation of nrf2, gpx4a, prdx6 and downregulation of acsl4a by VD3. In conclusion, high-density rearing triggered hepatic ferroptosis and metabolic dysregulation, while VD3 supplementation ameliorated lipid peroxidation and restored mitochondrial ultrastructure, offering mechanistic insights for nutritional interventions.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21445
BACKGROUND: Polyether ether ketone (PEEK) has insufficient inherent bioactivity, and as a bone implant material, it carries risks of poor osseointegration and implant-related infection. Developing surface modification strategies with both osteogenic and antibacterial functions is of great clinical significance for improving the implantation performance of PEEK. OBJECTIVE: To analyze the biocompatibility, osteogenic and antibacterial effects of PEEK loaded with polydopamine-modified strontium-doped hydroxyapatite-silver composite coating. METHODS: (1) A polydopamine-hydroxyapatite composite coating was prepared on the PEEK surface, denoted as PEEK@PDA-HA. According to the ratios of Sr2+/(Sr2++Ca2+) of 0%, 5%, 10%, and 20%, polydopamine-strontium-doped hydroxyapatite-silver composite coatings were prepared on the PEEK surface, denoted as PEEK@PDA-HA-Ag, PEEK@PDA-5Sr/HA-Ag, PEEK@PDA-10Sr/HA-Ag, and PEEK@PDA-20Sr/HA-Ag, respectively. MC3T3-E1 cells were co-cultured with PEEK, PEEK@PDA-HA-Ag, PEEK@PDA-5Sr/HA-Ag, PEEK@PDA-10Sr/HA-Ag, and PEEK@PDA-20Sr/HA-Ag. The best material was selected for subsequent experiments through cell proliferation, live/dead staining, and adhesion assays. The surface morphology and water contact angle of PEEK@PDA-10Sr/HA-Ag were characterized. (2) MC3T3-E1 cells were seeded on PEEK, PEEK@PDA-HA, PEEK@PDA-HA-Ag, and PEEK@PDA-10Sr/HA-Ag surfaces. After osteogenic induction, alkaline phosphatase staining, alizarin red staining, and osteocalcin immunofluorescence staining were performed to evaluate the osteogenic differentiation performance of the materials. (3) Escherichia coli (or Staphylococcus aureus) were co-cultured with PEEK, PEEK@PDA-HA, PEEK@PDA-HA-Ag, and PEEK@PDA-10Sr/HA-Ag. The antibacterial properties were evaluated by agar plate counting and bacterial live/dead staining. RESULTS AND CONCLUSION: (1) Cell proliferation, live/dead staining, and adhesion assays showed that PEEK@PDA-10Sr/HA-Ag had the best effect on promoting MC3T3-E1 cell proliferation, and the cells adhered on the material surface exhibited good morphology with many filopodia, making it suitable for subsequent experiments. Scanning electron microscopy revealed a rough and uneven surface of PEEK@PDA-10Sr/HA-Ag with numerous spherical nanoparticle aggregates. Compared with PEEK, the water contact angle of PEEK@PDA-10Sr/HA-Ag decreased, indicating enhanced hydrophilicity. (2) Alkaline phosphatase staining, alizarin red staining, and osteocalcin immunofluorescence staining showed that PEEK@PDA-10Sr/HA-Ag had the strongest osteogenic effect. (3) Bacterial plate counting and live/dead staining showed that compared with the other three groups, PEEK@PDA-10Sr/HA-Ag effectively inhibited the growth of Escherichia coli and Staphylococcus aureus. (4) These results indicate that PEEK loaded with polydopamine-modified strontium-doped hydroxyapatite-silver composite coating has good biocompatibility, osteogenic and antibacterial effects.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21492
BACKGROUND: Previous studies from our group have shown that triptolide exerts protective effects on nerve cells and alleviates symptoms of neurodegenerative diseases. However, whether it acts by improving mitochondrial dynamic abnormalities requires further investigation. OBJECTIVE: To explore the effect and mechanism of triptolide in regulating the mitochondrial fusion-fission balance to mitigate hydrogen peroxide (H₂O₂)-induced apoptosis in SH-SY5Y cells. METHODS: Human neuroblastoma SH-SY5Y cells were cultured and divided into three groups: control group, model group (200 μmol/L H₂O₂), and triptolide group (2.5 nmol/L triptolide + 200 μmol/L H₂O₂). After 24 hours of intervention, oxidative stress markers (superoxide dismutase activity and malondialdehyde levels), mitochondrial membrane potential, and apoptosis levels were measured. Western blot was used to detect the expression of apoptosis-related proteins, mitochondrial dynamics-related proteins, and respiratory chain-related proteins. Immunofluorescence staining was used to detect the expression of phosphorylated dynamin-related protein 1, optic atrophy protein 1, cytochrome C oxidase 1, and ATP synthase F1 subunit alpha. RESULTS AND CONCLUSION: Compared with the control group, the model group showed significantly decreased superoxide dismutase activity, mitochondrial membrane potential, anti-apoptotic protein Bcl-2, mitochondrial fusion proteins 1 and 2, optic atrophy protein 1, and oxidative phosphorylation complex proteins (NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, ubiquinol-cytochrome c reductase core protein 2, cytochrome c oxidase 1, succinate dehydrogenase B, ATP synthase F1 subunit alpha) (P < 0.05). Meanwhile, malondialdehyde levels, pro-apoptotic proteins Bax and Caspase-3, mitochondrial fission protein 1, phosphorylated dynamin-related protein 1 expression, and apoptosis rate were significantly increased (P < 0.05). Compared with the model group, triptolide intervention reduced malondialdehyde levels, increased superoxide dismutase activity and mitochondrial membrane potential, promoted fusion protein expression, inhibited fission protein expression, increased oxidative phosphorylation complex protein levels, and decreased apoptosis rate (P < 0.05). These results confirm that triptolide can regulate mitochondrial dynamic imbalance to alleviate H₂O₂-induced apoptosis in SH-SY5Y cells.
Acta Biochimica et Biophysica Sinica•2026•DOI: 10.3724/abbs.2026035
Pulmonary fibrosis (PF) is a life-threatening interstitial lung disease characterized by scarring and inflammation in lung tissues. Aberrant activation of the JAK/STAT and NF-κB signaling pathways is critical in initiating and sustaining the inflammatory processes that drive fibrotic progression. In this study, we identify a novel small-molecule compound, T4015, a 4-indolyl-2-phenylaminopyrimidine derivative, as a dual-pathway inhibitor targeting both JAK/STAT and NF-κB signaling. Dual-luciferase reporter assays demonstrate the potent inhibitory activity of T4015 against these pathways. T4015 effectively suppresses the phosphorylation of STAT3, JAK1, and TYK2 induced by IL-6 and IFN-β, while suppressing LPS-induced NF-κB activation in macrophages. Transcriptome sequencing and pathway enrichment analyses further confirm that T4015 downregulates multiple inflammation-related signaling cascades, including the JAK/STAT, NF-κB, TNF, IL-17, and Toll-like receptor pathways. In a mouse model of bleomycin-induced PF, T4015 treatment significantly improves survival, attenuates collagen deposition, and reduces the expression of pro-inflammatory and profibrotic markers such as IL-6, CCL2, and COL1. Molecular docking and target prediction analyses suggest that T4015 exhibits strong binding affinity for multiple kinases within the JAK/STAT and NF-κB networks, including JAK1, TYK2, JAK2, JAK3, RIPK1, IRAK1/4, TAB1, and ZAP70. Collectively, these results highlight T4015 as a promising therapeutic candidate for PF through its simultaneous inhibition of the JAK/STAT and NF-κB signaling pathways.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025065
Stem cell fate is profoundly influenced by a complex interplay of biochemical and biophysical cues, with the latter increasingly recognized for its roles in cellular processes, yet the mechanisms are unclear. Since chromatin accessibility is a critical determinant in the processes of osteogenesis and bone repair, investigating the contributions of open chromatin regions (OCRs) to the intracellular signaling pathways triggered by topographical cues, which lead to osteogenic differentiation is highly valuable. This study explores the impact of the nanotopography of biomaterials on the osteogenic differentiation of human bone marrow stem cells (hBMSCs). By utilizing electrospun poly-L-lactide (PLLA) membranes with random fiber arrangements, we mimic the natural extracellular matrix (ECM) topography to study its effects on hBMSCs, contrasting them with flat PLLA controls. Through high-throughput Assay for Transposase-Accessible Chromatin with sequencing (ATAC-seq) and RNA sequencing (RNA-seq), we reveal that the nanotopography of electrospun surfaces promotes osteogenic differentiation by modulating the chromatin accessibility of the YBX1 gene promoter, leading to its upregulation. Lentiviral knockdown experiments further confirm the crucial role of YBX1, revealing a reversal of the osteogenic effects induced by nanotopography. This study emphasizes the importance of YBX1 in the osteogenic response to the surface topography of biomaterials and suggests that nanotopographical cues could be harnessed to direct stem cell fate. These findings are important for developing biomaterials that promote specific stem cell outcomes in regenerative medicine. Our results further contribute to a deeper understanding of the mechanisms underlying stem cell differentiation in response to environmental cues and pave the way for the rational design of biomaterials with enhanced osteogenic potential. By elucidating the role of chromatin accessibility and specific transcription factors such as YBX1, this study highlights the intricate interplay between cell-material interactions and the intracellular signaling pathways that govern stem cell fate.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025125
African swine fever virus (ASFV), a large DNA virus with a 170–193 kb genome encoding 150–167 proteins, including over 68 structural proteins, poses a significant threat to the global swine industry. The lack of a comprehensive protein library hinders functional, antigenic, and vaccine studies. Here, we constructed an ASFV proteome library by expressing recombinant ASFV proteins with an N-terminal glutathione S-transferase (GST) tag in Saccharomyces cerevisiae. Through optimization of codons, expression vectors, strains, and expression and purification conditions, we achieved satisfactory yields for analytical applications, covering approximately 95% of the ASFV proteome. A protein chip fabricated from 94 proteins with concentrations above 5 μg/mL and purities greater than 90% was used to screen interactions between ASFV and swine proteins (IRF3, p65, and IκBα). Among purification methods, 96-deep-well plate purification yielded the highest protein purity, outperforming gravity-flow and peristaltic-pump-flow column chromatography, as explained by chromatographic plate theory. This library and the optimized methods provide a foundation for understanding ASFV biology and for developing diagnostics and vaccines, and are instructive for generating other proteome libraries for high-throughput applications.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025021
Homocysteine (Hcy) is an independent risk factor for atherosclerosis, and defective macrophage autophagy accelerates plaque formation. Pyruvate dehydrogenase (PDH), a key component of the PDH complex, links energy metabolism to autophagy, but its role in Hcy-induced atherosclerosis remains undefined. Proteomic profiling of Hcy-treated macrophages identified 748 upregulated and 760 downregulated proteins, with KEGG enrichment in amino acid biosynthesis, carbon metabolism, and glycolysis/gluconeogenesis. In ApoE–/– mice, Hcy treatment markedly reduced PDH expression and activity, leading to impaired autophagy. PDH activation restored autophagy by promoting assembly of the ULK1-FIP200-Atg13 complex via modulation of AMPK/mTOR signaling. These findings suggest that PDH activation may serve as a therapeutic strategy for Hcy-induced atherosclerosis.