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1.
ACP-Mediated Phase Transformation for Collagen Mineralization: A New Understanding of the Mechanism.
Shan, S, Tang, Z, Sun, K, Jin, W, Pan, H, Tang, R, Yin, W, Xie, Z, Chen, Z, Shao, C
Advanced healthcare materials. 2024;(2):e2302418
Abstract
Despite significant efforts utilizing advanced technologies, the contentious debate surrounding the intricate mechanism underlying collagen fibril mineralization, particularly with regard to amorphous precursor infiltration and phase transformation, persists. This work proposes an amorphous calcium phosphate (ACP)-mediated pathway for collagen fibril mineralization and utilizing stochastic optical reconstruction microscopy technology, and has experimentally confirmed for the first time that the ACP nanoparticles can infiltrate inside collagen fibrils. Subsequently, the ACP-mediated phase transformation occurs within collagen fibrils to form HAP crystallites, and significantly enhances the mechanical properties of the mineralized collagen fibrils compared to those achieved by the calcium phosphate ion (CPI)-mediated mineralization and resembles the natural counterpart. Furthermore, demineralized dentin can be effectively remineralized through ACP-mediated mineralization, leading to complete restoration of its mechanical properties. This work provides a new paradigm of collagen mineralization via particle-mediated phase transformation, deepens the understanding of the mechanism behind the mineralization of collagen fibrils, and offers a new strategy for hard tissue repair.
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2.
OsmiR5519 regulates grain size and weight and down-regulates sucrose synthase gene RSUS2 in rice (Oryza sativa L.).
Guo, S, Li, Y, Wang, Y, Xu, Y, Li, Y, Wu, P, Wu, J, Wang, L, Liu, X, Chen, Z
Planta. 2024;(5):106
Abstract
The up-regulation of OsmiR5519 results in the decrease of grain size, weight and seed setting rate. OsmiR5519 plays important roles in the process of grain filling and down-regulates sucrose synthase gene RSUS2. MicroRNAs (miRNAs) are one class of small non-coding RNAs that act as crucial regulators of plant growth and development. In rice, the conserved miRNAs were revealed to regulate the yield components, but the function of rice-specific miRNAs has been rarely studied. The rice-specific OsmiR5519 was found to be abundantly expressed during reproductive development, but its biological roles remain unknown. In this study, the function of rice-specific OsmiR5519 was characterized with the miR5519-overexpressing line (miR5519-OE) and miR5519-silenced line (STTM5519). At seedling stage, the content of sucrose, glucose and fructose was obviously lower in the leaves of miR5519-OE lines than those of wild-type (WT) line. The grain size and weight were decreased significantly in miR5519-OE lines, compared to those of WT rice. The cell width of hull in miR5519-OE was smaller than that in WT. The seed setting rate was notably reduced in miR5519-OE lines, but not in STTM5519 lines. Cytological observation demonstrated that the inadequate grain filling was the main reason for the decline of seed setting rate in miR5519-OE lines. The percentage of the defects of grain amounted to 40% in miR5519-OE lines, which almost equaled to the decreased value of seed setting rate. Furthermore, the sucrose synthase gene RSUS2 was identified as a target of OsmiR5519 via RNA ligase-mediated 3'-amplification of cDNA ends (3'-RLM-RACE), dual luciferase assays and transient expression assays. In summary, our results suggest that OsmiR5519 regulates grain size and weight and down-regulates RSUS2 in rice.
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3.
BVES-AS1 suppresses the colorectal cancer progression via the miR-1269a/b-SVEP1-PI3K/AKT axis.
Yang, J, Deng, Q, Chen, Z, Chen, Y, Fu, Z
Advances in clinical and experimental medicine : official organ Wroclaw Medical University. 2024
Abstract
BACKGROUND Numerous studies have indicated the engagement of long non-coding RNA (lncRNA) in various cancer types, including colorectal cancer (CRC). However, the functional and mechanistic roles of lncRNAs in CRC remain largely elusive. OBJECTIVES The aim of this study was to explore the function and mechanism of lncRNA BVES-AS1 in CRC. MATERIAL AND METHODS The expression levels of BVES-AS1 were validated in CRC tissues and paired normal samples using quantitative real-time polymerase chain reaction (qPCR) Subsequently, the biological functions of BVES-AS1 in CRC cells were investigated both in vitro and in vivo. Various experimental techniques such as western blot, fluorescence in situ hybridization, RNA-sequencing (RNA-seq), biotin-labeled miRNA pulldown assay, dual-luciferase reporter gene assay, and RNA-protein immunoprecipitation (RIP) assay were employed to elucidate the potential mechanism of BVES-AS1. RESULTS The findings of this study demonstrated that BVES-AS1 expression was downregulated in CRC tissues compared to normal tissues, and its expression level was associated with tumor infiltration and tumor-nodule-metastasis (TNM) stage. Furthermore, BVES-AS1 was found to suppress CRC cell proliferation, migration and metastasis both in vitro and in vivo. Mechanistically, BVES-AS1 acted as a sponge for miR-1269a and miR-1269b, thereby regulating SVEP1. Additionally, the silencing of SVEP1 activated the PI3K/AKT pathway. CONCLUSIONS These results suggest that BVES-AS1 plays a crucial role in the progression of CRC through the miR-1269a/b-SVEP1-PI3K/AKT axis, providing new insights into the therapeutic strategies for CRC.
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4.
Roles of SP/KLF transcription factors in odontoblast differentiation: From development to diseases.
Wang, X, Sun, K, Xu, Z, Chen, Z, Wu, W
Oral diseases. 2024
Abstract
OBJECTIVES A zinc-finger transcription factor family comprising specificity proteins (SPs) and Krüppel-like factor proteins (KLFs) plays an important role in dentin development and regeneration. However, a systematic regulatory network involving SPs/KLFs in odontoblast differentiation has not yet been described. This review examined the expression patterns of SP/KLF gene family members and their current known functions and mechanisms in odontoblast differentiation, and discussed prospective research directions for further exploration of mechanisms involving the SP/KLF gene family in dentin development. MATERIALS AND METHODS Relevant literature on SP/KLF gene family members and dentin development was acquired from PubMed and Web of Science. RESULTS We discuss the expression patterns, functions, and related mechanisms of eight members of the SP/KLF gene family in dentin development and genetic disorders with dental problems. We also summarize current knowledge about their complementary or synergistic actions. Finally, we propose future research directions for investigating the mechanisms of dentin development. CONCLUSIONS The SP/KLF gene family plays a vital role in tooth development. Studying the complex complementary or synergistic interactions between SPs/KLFs is helpful for understanding the process of odontoblast differentiation. Applications of single-cell and spatial multi-omics may provide a more complete investigation of the mechanism involved in dentin development.
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5.
Effect of Intensive Lifestyle Intervention on Cardiovascular Risk Factors: Analysis From the Perspective of Long-Term Variability.
He, L, Liu, M, Zhuang, X, Guo, Y, Wang, P, Zhou, Z, Chen, Z, Peng, L, Liao, X
Journal of the American Heart Association. 2024;(3):e030132
Abstract
BACKGROUND An association between variability of cardiovascular risk factors and cardiovascular events has been reported. We examined whether intensive lifestyle intervention (ILI) for weight loss decreased variability of cardiovascular risk factors with a view to additional cardiometabolic benefits. METHODS AND RESULTS This study was a post hoc secondary analysis of the Look AHEAD (Action for Health in Diabetes) study. Cardiovascular risk factors were measured at 1-year intervals for 4 years in 4249 adults with overweight or obesity and type 2 diabetes who were randomly assigned to ILI or diabetes support and education. Long-term variability was defined as the SD of cardiovascular risk factors during 4-year follow-up. At multiple linear regression analysis, compared with the diabetes support and education group, the ILI group was associated with reduced variability of fasting blood glucose (β=-1.49 [95% CI, -2.39 to -0.59]), total cholesterol (β=-1.12 [95% CI, -1.75 to -0.48]), and low-density lipoprotein cholesterol (β=-1.04 [95% CI, -1.59 to -0.49]), as well as increased variability of systolic blood pressure (β=0.27 [95% CI, 0.00-0.54]). No significant effect of ILI was found on the variability of diastolic blood pressure (β=-0.08 [95% CI, -0.22 to 0.05]). CONCLUSIONS Among adults with overweight or obesity and type 2 diabetes, ILI may reduce long-term variability of fasting blood glucose, total cholesterol, and low-density lipoprotein cholesterol. Our results support that ILI should be recommended to individuals with diabetes as part of management of long-term glycemic and blood lipid control.
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6.
Antibiotic-induced ROS-mediated Fur allosterism contributes to Helicobacter pylori resistance by inhibiting arsR activation of mutS and mutY.
Xue, J, Li, W, Zhao, Y, Wang, L, Cheng, P, Zhang, L, Zheng, Y, Zhang, W, Bi, Y, Chen, Z, et al
Antimicrobial agents and chemotherapy. 2024;(4):e0167923
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Abstract
The increasing antibiotic resistance of Helicobacter pylori primarily driven by genetic mutations poses a significant clinical challenge. Although previous research has suggested that antibiotics could induce genetic mutations in H. pylori, the molecular mechanisms regulating the antibiotic induction remain unclear. In this study, we applied various techniques (e.g., fluorescence microscopy, flow cytometry, and multifunctional microplate reader) to discover that three different types of antibiotics could induce the intracellular generation of reactive oxygen species (ROS) in H. pylori. It is well known that ROS, a critical factor contributing to bacterial drug resistance, not only induces damage to bacterial genomic DNA but also inhibits the expression of genes associated with DNA damage repair, thereby increasing the mutation rate of bacterial genes and leading to drug resistance. However, further research is needed to explore the molecular mechanisms underlying the ROS inhibition of the expression of DNA damage repair-related genes in H. pylori. In this work, we validated that ROS could trigger an allosteric change in the iron uptake regulatory protein Fur, causing its transition from apo-Fur to holo-Fur, repressing the expression of the regulatory protein ArsR, ultimately causing the down-regulation of key DNA damage repair genes (e.g., mutS and mutY); this cascade increased the genomic DNA mutation rate in H. pylori. This study unveils a novel mechanism of antibiotic-induced resistance in H. pylori, providing crucial insights for the prevention and control of antibiotic resistance in H. pylori.
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7.
Improving vitrification efficiency of human in vitro matured oocytes by the addition of LEA proteins.
Li, L, Bi, X, Wu, X, Chen, Z, Cao, Y, Zhao, G
Human reproduction (Oxford, England). 2024
Abstract
STUDY QUESTION Can the addition of late embryogenesis-abundant (LEA) proteins as a cryoprotective agent during the vitrification cryopreservation of in vitro matured oocytes enhance their developmental potential after fertilization? SUMMARY ANSWER LEA proteins improve the developmental potential of human in vitro matured oocytes following cryopreservation, mostly by downregulating FOS genes, reducing oxidative stress, and inhibiting the formation of ice crystals. WHAT IS KNOWN ALREADY Various factors in the vitrification process, including cryoprotectant toxicity, osmotic stress, and ice crystal formation during rewarming, can cause fatal damage to oocytes, thereby affecting the oocytes developmental potential and subsequent clinical outcomes. Recent studies have shown that LEA proteins possess high hydrophilicity and inherent stress tolerance, and can reduce low-temperature damage, although the molecular mechanism it exerts protective effects is still unclear. STUDY DESIGN, SIZE, DURATION Two LEA proteins extracted and purified by us were added to solutions for vitrification-warming of oocytes at concentrations of 10, 100, and 200 µg/mL, to determine the optimal protective concentration for each protein. Individual oocyte samples were collected for transcriptomic analysis, with each group consisting of three sample replicates. PARTICIPANTS/MATERIALS, SETTING, METHODS Immature oocytes were collected from patients who were undergoing combined in vitro fertilization (IVF) treatment and who had met the designated inclusion and exclusion criteria. These oocytes underwent in vitro maturation (IVM) culture for experimental research. A fluorescence microscope was used to detect the levels of mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and calcium in the mitochondria of vitrified-warmed human oocytes treated with different concentrations of LEA proteins, and the protective effect of the protein on mitochondrial function was assessed. The levels of intracellular ice recrystallization inhibition (IRI) in human oocytes after vitrification-warming were characterized by the cryomicroscope, to determine the LEA proteins inhibitory effect on recrystallization. By analyzing transcriptome sequencing data to investigate the potential mechanism through which LEA proteins exert their cryoprotective effects. MAIN RESULTS AND THE ROLE OF CHANCE The secondary structures of AfrLEA2 and AfrLEA3m proteins were shown to consist of a large number of α-helices and the proteins were shown to be highly hydrophilic, in agreement with previous reports. Confocal microscopy results showed that the immunofluorescence of AfrLEA2-FITC and AfrLEA3m-FITC-labeled proteins appeared to be extracellular and did not penetrate the cell membrane compared with the fluorescein isothiocyanate (FITC) control group, indicating that both AfrLEA2 and AfrLEA3m proteins were extracellular. The group treated with 100 µg/mL AfrLEA2 or AfrLEA3m protein had more uniform cytoplasmic particles and fewer vacuoles compared to the 10 and 200 µg/mL groups and were closest to the fresh group. In the 100 µg/mL groups, MMPs were significantly higher while ROS and calcium levels were significantly lower than those in the control group and were closer to the levels observed in fresh oocytes. Meanwhile, 100 µg/mL of AfrLEA2 or AfrLEA3m protein caused smaller ice crystal formation in the IRI assay compared to the control group treated with dimethylsulphoxide (DMSO) and ethylene glycol (EG); thus, the recrystallization inhibition was superior to that with the conventional cryoprotectants DMSO and EG. Further results revealed that the proteins improved the developmental potential of human oocytes following cryopreservation, likely by downregulating FOS genes and reducing oxidative stress. LIMITATIONS, REASONS FOR CAUTION The in vitro-matured metaphase II (IVM-MII) oocytes used in the study, due to ethical constraints, may not accurately reflect the condition of MII oocytes in general. The AfrLEA2 and AfrLEA3m proteins are recombinant proteins and their synthetic stability needs to be further explored. WIDER IMPLICATIONS OF THE FINDINGS LEA proteins, as a non-toxic and effective cryoprotectant, can reduce the cryoinjury of oocytes during cryopreservation. It provides a new promising method for cryopreservation of various cell types. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Key Research and Development Program of China (2022YFC2703000) and the National Natural Science Foundation of China (52206064). The authors declare no competing interest. TRIAL REGISTRATION NUMBER N/A.
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8.
Radical fluorine transfer catalysed by an engineered nonheme iron enzyme.
Zhao, Q, Chen, Z, Rui, J, Huang, X
Methods in enzymology. 2024;:231-247
Abstract
Nonheme iron enzymes stand out as one of the most versatile biocatalysts for molecular functionalization. They facilitate a wide array of chemical transformations within biological processes, including hydroxylation, chlorination, epimerization, desaturation, cyclization, and more. Beyond their native biological functions, these enzymes possess substantial potential as powerful biocatalytic platforms for achieving abiological metal-catalyzed reactions, owing to their functional and structural diversity and high evolvability. To this end, our group has recently engineered a series of nonheme iron enzymes to employ non-natural radical-relay mechanisms for abiological radical transformations not previously known in biology. Notably, we have demonstrated that a nonheme iron enzyme, (S)-2-hydroxypropylphosphonate epoxidase from Streptomyces viridochromogenes (SvHppE), can be repurposed into an efficient and selective biocatalyst for radical fluorine transfer reactions. This marks the first known instance of a redox enzymatic process for C(sp3)F bond formation. This chapter outlines the detailed experimental protocol for engineering SvHPPE for fluorination reactions. Furthermore, the provided protocol could serve as a general guideline that might facilitate other engineering endeavors targeting nonheme iron enzymes for novel catalytic functions.
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Emerging Contaminants: An Emerging Risk Factor for Diabetes Mellitus.
Niu, H, Xu, M, Tu, P, Xu, Y, Li, X, Xing, M, Chen, Z, Wang, X, Lou, X, Wu, L, et al
Toxics. 2024;(1)
Abstract
Emerging contaminants have been increasingly recognized as critical determinants in global public health outcomes. However, the intricate relationship between these contaminants and glucose metabolism remains to be fully elucidated. The paucity of comprehensive clinical data, coupled with the need for in-depth mechanistic investigations, underscores the urgency to decipher the precise molecular and cellular pathways through which these contaminants potentially mediate the initiation and progression of diabetes mellitus. A profound understanding of the epidemiological impact of these emerging contaminants, as well as the elucidation of the underlying mechanistic pathways, is indispensable for the formulation of evidence-based policy and preventive interventions. This review systematically aggregates contemporary findings from epidemiological investigations and delves into the mechanistic correlates that tether exposure to emerging contaminants, including endocrine disruptors, perfluorinated compounds, microplastics, and antibiotics, to glycemic dysregulation. A nuanced exploration is undertaken focusing on potential dietary sources and the consequential role of the gut microbiome in their toxic effects. This review endeavors to provide a foundational reference for future investigations into the complex interplay between emerging contaminants and diabetes mellitus.
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10.
Effect of injectable calcium alginate-amelogenin hydrogel on macrophage polarization and promotion of jawbone osteogenesis.
Zhao, T, Chen, L, Yu, C, He, G, Lin, H, Sang, H, Chen, Z, Hong, Y, Sui, W, Zhao, J
RSC advances. 2024;(3):2016-2026
Abstract
Due to persistent inflammation and limited osteogenesis, jawbone defects present a considerable challenge in regenerative medicine. Amelogenin, a major protein constituent of the developing enamel matrix, demonstrates promising capabilities in inducing regeneration of periodontal supporting tissues and exerting immunomodulatory effects. These properties render it a potential therapeutic agent for enhancing jawbone osteogenesis. Nevertheless, its clinical application is hindered by the limitations of monotherapy and its rapid release characteristics, which compromise its efficacy and delivery efficiency. In this context, calcium alginate hydrogel, recognized for its superior physicochemical properties and biocompatibility, emerges as a candidate for developing a synergistic bioengineered drug delivery system. This study describes the synthesis of an injectable calcium amelogenin/calcium alginate hydrogel using calcium alginate loaded with amelogenin. We comprehensively investigated its physical properties, its role in modulating the immunological environment conducive to bone healing, and its osteogenic efficacy in areas of jawbone defects. Our experimental findings indicate that this synthesized composite hydrogel possesses desirable mechanical properties such as injectability, biocompatibility, and biodegradability. Furthermore, it facilitates jawbone formation by regulating the bone-healing microenvironment and directly inducing osteogenesis. This research provides novel insights into the development of bone-tissue regeneration materials, potentially advancing their clinical application.