BACKGROUND: Temozolomide (TMZ) resistance is a significant challenge in treating glioblastoma (GBM). Collagen remodeling has been shown to be a critical factor for therapy resistance in other cancers. This study aimed to investigate the mechanism of TMZ chemoresistance by GBM cells reprogramming collagens. METHODS: Key extracellular matrix components, including collagens, were examined in paired primary and recurrent GBM samples as well as in TMZ-treated spontaneous and grafted GBM murine models. Human GBM cell lines (U251, TS667) and mouse primary GBM cells were used for in vitro studies. RNA-sequencing analysis, chromatin immunoprecipitation, immunoprecipitation-mass spectrometry, and co-immunoprecipitation assays were conducted to explore the mechanisms involved in collagen accumulation. A series of in vitro and in vivo experiments were designed to assess the role of the collagen regulators prolyl 4-hydroxylase subunit alpha 1 (P4HA1) and yes-associated protein (YAP) in sensitizing GBM cells to TMZ. RESULTS: This study revealed that TMZ exposure significantly elevated collagen type I (COL I) expression in both GBM patients and murine models. Collagen accumulation sustained GBM cell survival under TMZ-induced stress, contributing to enhanced TMZ resistance. Mechanistically, P4HA1 directly binded to and hydroxylated YAP, preventing ubiquitination-mediated YAP degradation. Stabilized YAP robustly drove collagen type I alpha 1 ( COL1A1) transcription, leading to increased collagen deposition. Disruption of the P4HA1-YAP axis effectively reduced COL I deposition, sensitized GBM cells to TMZ, and significantly improved mouse survival. CONCLUSION P4HA1 maintained YAP-mediated COL1A1 transcription, leading to collagen accumulation and promoting chemoresistance in GBM.
Temozolomide ; Humans ; Glioblastoma/drug therapy* ; Animals ; Mice ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics* ; YAP-Signaling Proteins ; Hydroxylation ; Dacarbazine/pharmacology* ; Adaptor Proteins, Signal Transducing/metabolism* ; Transcription Factors/metabolism* ; Collagen/biosynthesis* ; Collagen Type I/metabolism* ; Prolyl Hydroxylases/metabolism* ; Antineoplastic Agents, Alkylating/therapeutic use*

The circadian clock plays a critical role in regulating various physiological processes, including gene expression, metabolic regulation, immune response, and the sleep-wake cycle in living organisms. Post-translational modifications (PTMs) are crucial regulatory mechanisms to maintain the precise oscillation of the circadian clock. By modulating the stability, activity, cell localization and protein-protein interactions of core clock proteins, PTMs enable these proteins to respond dynamically to environmental and intracellular changes, thereby sustaining the periodic oscillations of the circadian clock. Different types of PTMs exert their effects through distincting molecular mechanisms, collectively ensuring the proper function of the circadian system. This review systematically summarized several major types of PTMs, including phosphorylation, acetylation, ubiquitination, SUMOylation and oxidative modification, and overviewed their roles in regulating the core clock proteins and the associated pathways, with the goals of providing a theoretical foundation for the deeper understanding of clock mechanisms and the treatment of diseases associated with circadian disruption.
Protein Processing, Post-Translational/physiology* ; Circadian Rhythm/physiology* ; Humans ; Animals ; CLOCK Proteins/physiology* ; Circadian Clocks/physiology* ; Phosphorylation ; Acetylation ; Ubiquitination ; Sumoylation

Sepsis is a life-threatening organ dysfunction caused by the host's dysregulated response to infection, with a complex pathogenesis and high mortality rate. Currently, there are no clear and effective treatment drugs available. Epigenetic modification serves as a major mechanism regulating gene expression under pathological and physiological conditions, and it has been shown to play a critical role in regulating the occurrence and development of sepsis. Histone acetylation modification, as a sophisticated epigenetic modification mechanism, plays a crucial regulatory role in many aspects of life. It can jointly regulate the acetylation status of histones through histone acetyltransferase (HAT) and histone deacetylase (HDAC), thereby changing DNA expression and dynamically regulating sepsis related gene expression at the epigenetic level. Previous studies have shown that histone acetylation can participate in the progression of sepsis by regulating inflammatory mediators, nuclear factor-ΚB (NF-ΚB) signaling pathway, autophagy, efferocytosis, ferroptosis, pyroptosis. These mechanisms are promising targets for novel sepsis treatments. In addition, with the deepening of research, it has been found that various selective/non selective histone deacetylase inhibitors (HDACI) can regulate histone acetylation status by acting on different HDAC targets, which has been shown to alleviate organ damage caused by sepsis and improve prognosis in septic animal models. This article further summarizes the role and potential applications of histone acetylation in sepsis, providing new ideas for the treatment of sepsis.
Sepsis/metabolism* ; Acetylation ; Humans ; Histones/metabolism* ; Histone Acetyltransferases/metabolism* ; Histone Deacetylase Inhibitors ; Epigenesis, Genetic ; Histone Deacetylases/metabolism* ; Signal Transduction ; NF-kappa B/metabolism* ; Animals

Benzylisoquinoline alkaloids (BIAs) are a structurally diverse group of plant metabolites renowned for their pharmacological properties. However, sustainable sources for these compounds remain limited. Consequently, researchers are focusing on elucidating BIA biosynthetic pathways and genes to explore alternative sources using synthetic biology approaches. CYP80B, a family of cytochrome P450 (CYP450) enzymes, plays a crucial role in BIA biosynthesis. Previously reported CYP80Bs are known to catalyze the 3'-hydroxylation of (S)-N-methylcoclaurine, with the N-methyl group essential for catalytic activity. In this study, we successfully cloned a full-length CYP80B gene (StCYP80B) from Stephania tetrandra (S. tetrandra) and identified its function using a yeast heterologous expression system. Both in vivo yeast feeding and in vitro enzyme analysis demonstrated that StCYP80B could catalyze N-methylcoclaurine and coclaurine into their respective 3'-hydroxylated products. Notably, StCYP80B exhibited an expanded substrate selectivity compared to previously reported wild-type CYP80Bs, as it did not require an N-methyl group for hydroxylase activity. Furthermore, StCYP80B displayed a clear preference for the (S)-configuration. Co-expression of StCYP80B with the CYP450 reductases (CPRs, StCPR1, and StCPR2), also cloned from S. tetrandra, significantly enhanced the catalytic activity towards (S)-coclaurine. Site-directed mutagenesis of StCYP80B revealed that the residue H205 is crucial for coclaurine catalysis. Additionally, StCYP80B exhibited tissue-specific expression in plants. This study provides new genetic resources for the biosynthesis of BIAs and further elucidates their synthetic pathway in natural plant systems.
Cytochrome P-450 Enzyme System/chemistry* ; Benzylisoquinolines/chemistry* ; Hydroxylation ; Plant Proteins/chemistry* ; Alkaloids/metabolism* ; Stephania tetrandra/genetics*

As the chip of synthetic biology, enzymes play a vital role in the bio-manufacturing industry. The development of diverse functional enzymes can provide a rich toolbox for the development of synthetic biology. This article reports the construction of an artificial enzyme with the introduction of a non-natural cofactor. By introducing the 4-dimethylaminopyridine (DMAP) cofactor into the optimal protein skeleton via covalent bonds based on a click-chemistry strategy, we successfully constructed a novel artificial enzyme with the DMAP cofactor as the catalytic center. The artificial enzyme successfully catalyzed an unnatural asymmetric Morita-Baylis- Hillman (MBH) reaction between cycloketenone and p-nitrobenzaldehyde, with a conversion rate of 90% and enantioselectivity (e.e.) of 38%. This study not only provides an effective strategy for the design of new artificial enzymes but also establishes a theoretical basis for the development of unnatural biocatalytic MBH reactions.
Biocatalysis ; 4-Aminopyridine/chemistry* ; Enzymes/metabolism* ; Coenzymes/chemistry* ; Benzaldehydes/chemistry* ; Protein Engineering/methods* ; Click Chemistry

CD20 is a surface marker protein of B-cell lymphoma, and its extracellular region is the target of specific antibodies and drugs. To obtain a cheap and easily modified specific preparation targeting CD20, we optimized the gene of CD20 extracellular region according to codon degeneracy to facilitate its expression in Escherichia coli. The optimized gene was cloned into pGEX-4T-1 vector, and the recombinant vector was transformed into E. coli BL21(DE3) for expression. The purified protein was identified by SDS-PAGE and Western blotting. Systematic evolution of ligands by exponential enrichment (SELEX) was employed to screen the ssDNA aptamer that specifically binds to the fusion protein, and the affinity of the aptamer to CD20 was detected by flow cytometry. Then, the cytotoxicity test was carried out to examine the inhibitory effect of the aptamer on B lymphoma cells. In this study, we established the prokaryotic expression method of CD20 and obtained the aptamer specifically binding to the extracellular region of CD20, which laid a foundation for the development of therapeutic drugs targeting CD20.
Humans ; Escherichia coli/metabolism* ; SELEX Aptamer Technique/methods* ; Aptamers, Nucleotide/genetics* ; Antigens, CD20/metabolism* ; Ligands

Small urban wetlands are widely distributed and susceptible to human activities, serving as important sources and sinks of carbon. Microorganisms play a crucial role in carbon cycle, while limited studies have been conducted on the microbial diversity in small urban wetlands and the functions of microbiome in carbon fixation and metabolism. To probe into the microbiome-driven carbon cycling in small urban wetlands and dissect the composition and functional groups of microbiome, we analyzed the relationships between the microbiome structure, element metabolism pathways, and habitat physicochemical properties in sediment samples across three small wetlands in Huzhou City, and compared them with natural wetlands in the Zoige wetland. High-throughput sequencing of 16S rRNA gene amplicons and metagenomics was employed to determine the species and functional groups. Sixty medium to high-quality metagenome-assembled genomes (MAGs) were constructed, including 55 bacterial and 5 archaeal taxa, and their potential in driving elemental cycles were analyzed, with a focus on carbon fixation. Several bacterial species were found to encode a nearly complete carbon fixation pathway, including the Calvin cycle, the reductive tricarboxylic acid cycle, the Wood-Ljungdahl pathway, and the reductive glycine pathway. There were several potential novel carbon-fixing bacterial members, such as those belonging to Syntrophorhabdus (Desulfobacterota) and UBA4417 (Bacteroidetes), which had high relative abundance in the wetland microbiome. Unveiling the genetic potential of these functional groups to facilitate element cycling is of great scientific importance for enhancing the carbon sequestration capacity of small urban wetlands.
Wetlands ; Microbiota/genetics* ; Carbon Cycle/genetics* ; Bacteria/classification* ; RNA, Ribosomal, 16S/genetics* ; China ; Cities ; Geologic Sediments/microbiology* ; Archaea/classification* ; Metagenomics ; Metagenome

Microalgae possess high photosynthetic efficiency, robust adaptability, and substantial biomass, serving as excellent biological resources for large-scale cultivation. Malic enzyme (ME), a ubiquitous metabolic enzyme in living organisms, catalyzes the decarboxylation of malate to produce pyruvate, CO₂, and NAD(P)H, playing a role in multiple metabolic pathways including energy metabolism, photosynthesis, respiration, and biosynthesis. In this study, we identified the Scenedesmus quadricauda malic enzyme gene (SqME) and its biological functions, aiming to provide excellent target genes for the genetic improvement of higher plants. Based on the RNA-seq data from S. quadricauda under the biofilm cultivation mode with high CO₂ and light energy transfer efficiency and small water use, a highly expressed gene (SqME) functionally annotated as ME was cloned. The physicochemical properties of the SqME-encoded protein were systematically analyzed by bioinformatics tools. The subcellular localization of SqME was determined via transient transformation in Nicotiana benthamiana leaves. The biological functions of SqME were identified via genetic transformation in Nicotiana tabacum, and the potential of SqME in the genetic improvement of higher plants was evaluated. The ORF of SqME was 1 770 bp, encoding 590 amino acid residues, and the encoded protein was located in chloroplasts. SqME was a NADP-ME, with the typical structural characteristics of ME. The ME activity in the transgenic N. tabacum plant was 1.8 folds of that in the wild-type control. Heterologous expression of SqME increased the content of chlorophyll a, chlorophyll b, and total chlorophyll by 20.9%, 26.9%, and 25.2%, respectively, compared with the control. The transgenic tobacco leaves showed an increase of 54.0% in the fluorescence parameter NPQ and a decrease of 30.1% in Fo compared with the control. Moreover, the biomass, total lipids, and soluble sugars in the transgenic tobacco leaves enhanced by 20.5%, 25.7%, and 9.5%, respectively. On the contrary, the starch and protein content in the transgenic tobacco leaves decreased by 22.4% and 12.2%, respectively. Collectively, the SqME-encoded protein exhibited a strong enzymatic activity. Heterologous expressing of SqME could significantly enhance photosynthetic protection, photosynthesis, and biomass accumulation in the host. Additionally, SqME can facilitate carbon metabolism remodeling in the host, driving more carbon flux towards lipid synthesis. Therefore, SqME can be applied in the genetic improvement of higher plants for enhancing photosynthetic carbon fixation and lipid accumulation. These findings provide scientific references for mining of functional genes from S. quadricauda and application of these genes in the genetic engineering of higher plants.
Nicotiana/genetics* ; Photosynthesis/physiology* ; Malate Dehydrogenase/biosynthesis* ; Plant Leaves/genetics* ; Scenedesmus/enzymology* ; Carbon Cycle/genetics* ; Lipid Metabolism/genetics* ; Plants, Genetically Modified/metabolism*

Objective To investigate the impact of Astragaloside-IV (AS-IV) on the progression of myocardial infarction (MI) through macrophage-dependent mechanisms by regulating Snail1 lactylation and acetylation, as well as the transforming growth factor β (TGF-β) pathway. Methods Oxygen glucose deprivation (OGD) was used to establish an in vitro myocardial ischemia model in rat cardiomyocytes (H9c2), which were then treated with AS-IV. Cell viability was assessed using CCK-8, apoptosis was evaluated by flow cytometry, and LDH levels were measured to assess cellular damage. RAW246.7 cells were treated with LPS, and lactate levels in the supernatant were measured using ELISA, while expression of macrophage phenotype markers was evaluated using Western blot. RAW246.7 cell-conditioned medium (CM) was co-cultured with H9c2 cells to assess the protective effects of AS-IV on macrophage CM-mediated H9c2 damage. RAW246.7 cells were induced to differentiate into M1-like macrophages using LPS (100 ng/mL) + IFN-γ (20 ng/mL), and Snail1 was overexpressed in M1 macrophages. Transfected M1 macrophage CM was co-cultured with H9c2 cells to validate the mechanisms of AS-IV in MI. An MI rat model was established by ligation of the left anterior descending coronary artery (LAD), and was treated with AS-IV. Cardiac function, myocardial cell apoptosis, and cardiac tissue pathology were studied using echocardiography, TUNEL, and HE staining, respectively. Results Compared to the OGD group, AS-IV treatment promoted cell viability, reduced apoptosis and decreased LDH release. LPS upregulated lactate levels in the supernatant of RAW246.7 cell cultures and induced polarization of RAW246.7 cells to the M1 phenotype. AS-IV attenuated the damaging effects of RAW246.7 cell CM on H9c2 cells . Overexpression of Snail1 in M1 macrophages weakened the protective effects of AS-IV on H9c2 cells . In vivo study, results showed that, compared to the MI group, AS-IV treatment reduced lactate levels in the hearts of MI rats, improved cardiac function and myocardial injury and attenuated myocardial cell apoptosis. Conclusion AS-IV inhibits TGF-β pathway activation through the suppression of Snail1 lactylation and acetylation in a macrophage-dependent manner, thereby mitigating myocardial cell damage following MI.
Animals ; Myocardial Infarction/drug therapy* ; Rats ; Snail Family Transcription Factors/metabolism* ; Macrophages/cytology* ; Myocytes, Cardiac/metabolism* ; Triterpenes/pharmacology* ; Saponins/pharmacology* ; Acetylation/drug effects* ; Apoptosis/drug effects* ; Mice ; Cell Line ; RAW 264.7 Cells ; Transforming Growth Factor beta/metabolism*

OBJECTIVES: To explore the mechanism by which histone deacetylase 1 (HDAC1) regulates steroid-induced apoptosis of mouse osteocyte-like MLO-Y4 cells. METHODS: MLY-O4 cells were treated with 400 nmol/L trichostatin A (TSA) or 1 mmol/L dexamethasone for 24 h or transfected with a HDAC1-overexpressing vector prior to TSA or dexamethasone treatment. The changes in the expressions of HDAC1, SP1, cleaved caspase-3 and Bax, SP1 acetylation level, cell proliferation, and cell apoptosis were examined. The interaction between HDAC1 and SP1 was determined with immunoprecipitation assay and Western blotting. RESULTS: Treatment with dexamethasone significantly increased cell apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, reduced HDAC1 expression, and suppressed proliferation of MLO-Y4 cells. Both TSA and dexamethasone obviously increased SP1 acetylation level and the expression of SP1 in MLO-Y4 cells. HDAC1 overexpression in the cells significantly attenuated the effect of TSA and dexamethasone, promoted cell proliferation, lowered the expressions of SP1, cleaved caspase-3 and Bax, and inhibited dexamethasone-induced cell apoptosis. Immunoprecipitation assay and Western blotting demonstrated the interaction between HDAC1 and SP1 in the cells. CONCLUSIONS HDAC1 inhibits dexamethasone-induced apoptosis and promotes proliferation of cultured mouse osteocytes by suppressing SP1 expression via promoting its deacetylation.
Animals ; Apoptosis/drug effects* ; Mice ; Histone Deacetylase 1/genetics* ; Osteocytes/drug effects* ; Sp1 Transcription Factor/metabolism* ; Acetylation ; Dexamethasone/pharmacology* ; Cell Proliferation/drug effects* ; Caspase 3/metabolism* ; Cell Line ; Hydroxamic Acids/pharmacology* ; bcl-2-Associated X Protein/metabolism*