Journal of Zhejiang University SCIENCE B最新文献

This study used molecular dynamics simulations, B-factor analysis, and saturation mutagenesis screening to enhance the thermal stability of the trans-epoxysuccinate hydrolase (TESH) derived from Pseudomonas koreensis. Eleven mutants that influence this characteristic were selected, yielding four mutants with improved activity. Among them, mutants A142C and S178Q exhibited lower Michaelis constant (K_m) values, and their k_cat/K_m ratios (k_cat, catalytic constant) were 3.7 and 0.9 times higher than those of the wild type, respectively. The values of half-life at 50 ℃ (T 1/ 2 50) of the two mutants were increased by 107% and 59%, respectively, compared to the wild type. Molecular docking and molecular dynamics simulations indicated that the two mutants showed stronger substrate interaction, lower binding energy, and reduced root mean square deviation compared to the wild type, along with decreased electrostatic potential energy and increased hydrophobicity near their mutation sites. The study of protein thermal stability engineering and associated mechanisms provides a valuable reference and holds practical significance for the industrial production of meso-tartaric acid.

The intestinal microbiome, which is a key factor in the maintenance of host gut homeostasis, enhances intestinal mucosal barrier function and immune tolerance (Rooks and Garrett, 2016; Skelly et al., 2019). However, the specific immunomodulatory functions of microbiota-derived metabolites in mucosal inflammatory responses remain largely unknown. The effects of microbial metabolites may vary across different immune cell types and host homeostasis (Hu et al., 2023; Zhao et al., 2023). Hence, it is fundamental to understand how specific intestinal microbes and their metabolic small molecules cause or mitigate gut-related diseases like inflammatory bowel disease (IBD). It has been uncovered that during the pathogenesis of IBD, excessive T helper 1 cell (Th1)/Th17 activation and impaired function of colonic regulatory T cells (Tregs) occur (Subramanian, 2020). Given that colonic Tregs play an important role in inhibiting IBD via secreting immunosuppressive cytokines, the molecular mechanisms linking certain intestinal microbes and their metabolites to Treg-mediated immune tolerance are yet to be fully understood.

Real-world studies (RWSs) have emerged as a transformative force in oncology research, complementing traditional randomized controlled trials (RCTs) by providing comprehensive insights into cancer care within routine clinical settings. This review examines the evolving landscape of RWSs in oncology, focusing on their implementation, methodological considerations, and impact on precision medicine. We systematically analyze how RWSs leverage diverse data sources, including electronic health records (EHRs), insurance claims, and patient registries, to generate evidence that bridges the gap between controlled clinical trials and real-world clinical practice. The review underscores the key contributions of RWSs, including capturing therapeutic outcomes in traditionally underrepresented populations, expanding drug indications, and evaluating long-term safety and effectiveness in routine clinical settings. While acknowledging significant challenges, including data quality variability and privacy concerns, we discuss how emerging technologies like artificial intelligence are helping to address these limitations. The integration of RWSs with traditional clinical research is revolutionizing the paradigm of precision oncology and enabling more personalized treatment approaches based on real-world evidence.

Premenstrual dysphoric disorder (PMDD), a subtype of premenstrual syndrome (PMS), involves physical and emotional symptoms that impact patients' daily lives and productivity. A reliable, side-effect-free clinical intervention is needed. Shuyu capsule is an effective traditional Chinese medicine preparation for PMDD used in the clinics, but its therapeutic mechanism remains unclear. Previous research has suggested that the γ-aminobutyric acidergic (GABAergic) system in the periaqueductal gray (PAG) may play a role in treating PMDD with traditional Chinese medicine, but there is a lack of functional verification. This study aims to reveal the potential mechanism of the Shuyu capsule in treating PMDD. The study employed an experimental design using female C57BL/6J and Vgat-Cre mice to assess the effects of Shuyu capsules on PMDD, with a focus on the GABAergic system in the dorsal PAG (dPAG). Assessments were conducted using the forced swimming test (FST) to gauge depression-like behaviors and western blot (WB) and immunofluorescence (IF) to measure the numbers of active GABAergic neurons and the γ-aminobutyric acid type A receptor (GABA_AR) δ subunit (GABRD) expression. Chemogenetic techniques and adeno-associated virus were specifically used to activate GABAergic neurons and knock down the expression of subunits, respectively, providing insights into the neurobiological mechanisms underpinning the therapeutic effects of Shuyu capsules in treating PMDD. After being stressed by FST, the immobility duration of PMDD mice in the late dioestrus (LD) phase decreased after the Shuyu capsule intervention, implying that it can improve the estrous cycle-dependent depression-like phenotype in PMDD mice. Additionally, the application of Shuyu capsule can downregulate the expression of GABRD and reverse the downtrend of activated GABAergic neurons in the dPAG of PMDD model mice. We also found that single-target manipulation was enough to improve the depression-like behavior of PMDD model mice. Transgenic mice with GABRD knockout were established, and their behaviors were tested, revealing changes in their exploratory behaviors, indicating that the GABRD may be closely related to anxiety disorders. Shuyu capsule plays an anti-PMDD role by activating GABAergic neurons and downregulating the expression of GABRD in the dPAG. This provides a theoretical basis for the clinical treatment of PMDD with traditional Chinese medicine and promotes the development of drugs for treating PMDD.

Carbonyl reductase 1 (CBR1), a member of the short-chain dehydrogenase/reductase (SDR) superfamily, is implicated in tumor progression and treatment resistance. However, its role in non-small cell lung cancer (NSCLC) remains unclear. This study examined CBR1 expression in NSCLC tissues and cell lines, using gene interference and pharmacological inhibition to assess its impact on stemness, chemosensitivity, and quiescence, and to explore underlying mechanisms. Our findings indicate that CBR1 expression is elevated in NSCLC tissues and cell lines, and further increases in the presence of cisplatin (CDDP). Gene interference reducing CBR1 expression significantly decreased the percentage of cluster of differentiation 133 (CD133)-positive cells and the expression of octamer-binding transcription factor 4 (OCT4) and SRY (sex determining region Y)-box 2 (SOX2), while enhancing CDDP chemosensitivity. The CBR1-specific inhibitor hydroxy-PP-Me (PP-Me) markedly increased CDDP cytotoxicity and reduced stemness. Additionally, CBR1 inhibition via short hairpin RNA (shRNA) CBR1 (sh-CBR1) or PP-Me disrupted NSCLC cell quiescence, as shown by a decrease in G0 phase cells and p27 expression, alongside an increase in cyclin D1 and phospho-retinoblastoma (pRb) expression. Furthermore, SET domain-containing protein 4 (SETD4), which mediates stemness, chemosensitivity, and quiescence in NSCLC cells, was downregulated by sh-CBR1 or PP-Me treatment. The overexpression of SETD4 counteracted the enhanced chemosensitivity resulting from CBR1 inhibition. In A549 xenografts, combined PP-Me and CDDP therapy significantly inhibited tumor growth compared to either treatment alone. In conclusion, CBR1 inhibition enhances CDDP chemosensitivity by suppressing stemness and quiescence in NSCLC.

Hydrogels, owing to their porous network structure resembling the extracellular matrix (ECM), have become essential scaffold materials in the field of cartilage tissue engineering. Among them, gelatin methacrylate (GelMA) hydrogels are widely used in bioink development due to their excellent biocompatibility, biodegradability, and tunable photo-crosslinking properties. However, the high biocompatibility of pure GelMA often comes at the cost of mechanical strength, limiting its applicability in cartilage regeneration. To overcome this trade-off, this study developed composite bioinks based on GelMA, silk fibroin (SF), and polyethylene oxide (PEO) for fabricating porous hydrogel scaffolds, which were then systematically characterized in terms of morphology, porosity, hydrophilicity, mechanical strength, rheological behavior, printability, and cytocompatibility. In this design, PEO serves as a porogen to generate highly porous structures (porosity up to 88%), while SF compensates for the mechanical loss caused by PEO, enabling the scaffold to retain a compression strength of up to 29.10 kPa. Among the tested formulations, the 10% GelMA/1% SF/1.5% PEO (1%=0.01 g/mL) bioink exhibited excellent printability, mechanical integrity, and cytocompatibility, and it supported a robust deposition of collagen II and aggrecan by chondrocytes after printing. This work provides a versatile strategy for balancing the biocompatibility and mechanical robustness in bioinks, offering a promising platform for next-generation cartilage tissue engineering scaffolds.

Poly(ADP-ribose) polymerase (PARP) is a family of proteins that play a crucial role in diverse cellular processes, including DNA repair, cell death, and changes in chromatin structure. PARP inhibitors (PARPi) have been recognized as notable agents in the realm of anticancer therapeutics owing to their capacity to specifically impact DNA repair pathways, thereby inducing targeted death of cancerous cells, particularly in cancers with homologous recombination deficiency (HRD). These inhibitors have been approved for the treatment of several cancers, such as ovarian, breast, and pancreatic cancers. Despite their promising therapeutic attributes, developing resistance to PARPi presents a formidable obstacle, curtailing their overall efficacy. This article presents a comprehensive description of the potential mechanisms related to PARPi resistance, an in-depth study of potential strategies to overcome resistance, and an assessment of the therapeutic potential of the PARPi in combination with alternative therapies.

Acute respiratory distress syndrome (ARDS) is a form of progressive hypoxemia that can be brought on by a variety of cardiorespiratory or systemic disorders, such as coronavirus disease 2019 (COVID-19). The binding of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus spike protein to the cell membrane is mediated through its binding to angiotensin-converting enzyme 2 (ACE2) receptors, resulting in viral entry, replication, and induction of a signaling cascade inducing pro-inflammatory responses that are linked to a higher mortality rate and the progression of ARDS, leading to multi-organ failure in these patients. We aimed to analyze the relationships between circulating gene expression levels of ACE2, Toll-like receptor 4 (TLR4), and interleukin-17 (IL-17) and the clinical severity of COVID-19, as well as the associated pathogenic conditions, in hospitalized patients. Sixty COVID-19 patients (34 mild/moderate COVID-19 and 26 COVID-19 with severe ARDS manifestation) and 60 healthy controls were included. The patient group was also subdivided according to outcomes into 32 recoveries and 28 deaths. ACE2, TLR4, and IL-17 levels were assessed by quantitative polymerase chain reaction (qPCR) in addition to all routine baseline laboratory investigations, including complete blood count (CBC) with differential analysis and the levels of C-reactive protein (CRP), ferritin, and d-dimer. ACE2, TLR4, and IL-17 serum expression levels were significantly higher in the COVID-19 group and subgroups and were correlated with different laboratory and clinical parameters. The serum expression levels of ACE2, TLR4, and IL-17 were accurate in differentiating between the patient groups and controls, with 86.7%, 91.7%, and 95.0% sensitivity and 96.7%, 98.3%, and 98.3% specificity, respectively, and correlated with more severe disease courses in COVID-19 patients. Higher levels are associated with overwhelmingly distressing outcomes. Our results allow us to conclude that increased circulating gene expression levels of ACE2, TLR4, and IL-17 are important in assessing the severity of COVID-19. Consequently, targeting these biomarkers may offer additional therapeutic options for COVID-19 patients in the future.

Macrophages are sensitive cells to various external mechanical forces in the environment, such as stretch, shear, and pressure. Mechanical forces can be recognized by mechanical signal receptors on the cell surface, such as cell adhesion molecules and ion channels, and transformed into intracellular biological signals, in turn activating different signaling pathways and thereby regulating the phagocytosis, migration, and polarization of macrophages. The phenomenon in which macrophages transform into different activated phenotypes and perform different functions under varying environmental stimuli is also known as macrophage polarization. In this review, we discuss the roles of mechanically sensitive integrins and ion channels in the mechanical signal sensing of macrophages. We expound on several downstream signaling pathways closely related to integrins and ion channels, such as the nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) pathways, which have made good research progress. In addition, we summarize some in vitro experiments on the regulation of macrophage polarization by external mechanical forces, some current cell models for macrophages in vitro, and some commonly used force application devices, with the aim to provide convenience for future in vitro research on macrophages. This paper offers a deep understanding of the mechanical sensitivity and conduction mechanisms of macrophages, which can provide new ideas for the treatment of human diseases.

Bone-related diseases, including osteoporosis (OP), osteoarthritis (OA), rheumatoid arthritis (RA), fracture, and periodontitis, significantly impact human health. Succinate, primarily known as a metabolic intermediate in the tricarboxylic acid (TCA) cycle, has emerged as a regulator of cellular functions beyond its metabolic role. Under stress, succinate accumulates in mitochondria and acts as a signaling molecule, modulating cellular processes. Notably, succinate activates angiogenesis and inflammation by stabilizing hypoxia-inducible factor-1α (HIF-1α). Moreover, it influences various pathophysiological processes by interacting with the succinate receptor 1 (SUCNR1), thereby impacting immune response, inflammation, cancer metastasis, and bone homeostasis. The multifaceted roles of succinate as a signaling molecule vary depending on its cellular location and concentration. Recent metabolomic analyses have revealed elevated succinate levels in bone-related diseases, indicating its potential association with these conditions. The objective of this review is to elucidate the impacts of succinate on different bone-related diseases and to discuss potential therapeutic targets and drug molecules based on its mechanisms of action.