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Biomedical subjects

Hua Zhang

Publications and source records attributed to Hua Zhang.

6 recordsLinked to original sources

Differentiated extraction strategies for selenium speciation in hyperaccumulator and non-hyperaccumulator plants via orthogonal LC-AFS.

The growing demand for selenium (Se)-enriched products highlights the need for accurate and accessible Se speciation analysis. In this study, a cost-effective orthogonal liquid chromatography-atomic fluorescence spectrometry (LC-AFS) method was developed for the determination of seven Se species (SeO3 2-, SeO4 2-, SeLan, SeMet, SeCys2, MeSeCys, and γ-GluMeSeCys), providing an alternative to ICP-MS-based approaches. Differences in Se accumulation mechanisms between hyperaccumulator Cardamine hupingshanensis and non-hyperaccumulator wheat significantly affected extraction efficiency. The sequential aqueous-enzymatic extraction increased SeLan recovery in C. hupingshanensis from 5.06 to 143.74 μg Se g-1, a 28.41-fold increase, while anaerobic extraction enhanced SeMet recovery in wheat from 98.73 to 112.17 μg Se g-1. Consequently, matrix-specific strategies improved Se recoveries from 20.82% to 80.65% in C. hupingshanensis and from 34.11% to 90.02% in wheat. These findings highlight the importance of matrix-specific extraction for accurate Se speciation analysis.

Cardamine hupingshanensis

Development and validation of a serum peptidomic signature for early detection of asymptomatic ovarian cancer: A multi-center prospective study.

Early detection of asymptomatic ovarian cancer (asym-OC) remains a critical challenge, the failure of which underlies its high mortality. Performing serum peptidomic profiling of 843 participants in the cohort SOCFCP, we distill 1,081 initial features into a 7-marker panel for asym-OC detection via a biology-informed machine-learning (ML)-based feature selection strategy. Three markers significantly revert toward non-OC levels after surgery. Integrating the panel with age, CA125, and HE4, we develop and externally validate (n = 159) a LightGBM model, ProMS+. For early-stage OC detection, ProMS+ shows a specificity of 92.6% at 95.0% sensitivity, outperforming CA125 (44.7%), HE4 (11.2%), and Risk of Ovarian Malignancy Algorithm (ROMA) (24.0%), with an area under the curve (AUC) of 0.993. In a simulated high-risk population (n = 100,000; OC prevalence = 1%), ProMS+ yields a high AUC (0.983) and a higher positive predictive value than CA125, HE4, and Age + CA125 + HE4 combined model (0.201 vs. 0.027, 0.090, and 0.064). ProMS+ offers a promising, non-invasive, and interpretable approach for the early detection of asym-OC.

Humans

Maternal PAN2 selectively maintains mRNA Poly(A) tail homeostasis to regulate RNA degradation during oocyte-to-early embryo transition in mice.

In mammals, the precise degradation of maternal mRNAs is essential for oocyte maturation and early embryonic development, as it facilitates the "maternal-to-zygotic transition (MZT)" by eliminating maternal transcripts and enabling zygotic genome activation (ZGA). However, the physiological role of the poly(A)-specific nuclease 2 (PAN2), a deadenylase that initiates cascade degradation of long-tailed transcripts, remains unknown. Here, we generated oocyte-specific Pan2 conditional knockout (cKO) mice to investigate its role. We found that Pan2 cKO females exhibit severe female subfertility despite normal oocyte maturation and ovulation, with embryos arresting at the 2-cell stage. PAIso-seq2 and transcriptome sequencing reveal that PAN2 coordinates maternal mRNA deadenylation and decay. Mechanistically, PAN2 recognizes its substrates through a PAN3-PABPC1 bridging complex, and it preferentially targets transcripts whose poly(A) tails lack guanosine (G) but are enriched for uridine (U). PAN2 deficiency causes poly(A) tail dyshomeostasis, leading to global accumulation of maternal mRNAs, impaired zygotic genome activation, and abnormal protein accumulation in 2-cell embryos. Overexpression of these proteins phenocopies developmental defects. Notably, the PAN2-regulated transcriptome is largely non-overlapping with the LC3B-mediated degradation pathway, highlighting the unique and non-redundant role of PAN2 in maternal mRNA clearance. Our study establishes maternal PAN2 as a critical regulator of poly(A) tail homeostasis, ensuring timely maternal mRNA clearance and proper ZGA, highlighting the stage-specific and tail-composition-dependent functions of the deadenylase cascade during the maternal-to-zygotic transition. These findings offer new perspectives on post-transcriptional regulatory mechanisms in early mammalian embryogenesis.

Deadenylation

Genomic and Transcriptomic Landscape of Epstein-Barr Virus-Positive Inflammatory Follicular Dendritic Cell Sarcoma: A Multicenter Study.

Epstein-Barr virus (EBV)-positive inflammatory follicular dendritic cell sarcoma (EBV+ IFDCS) is a rare indolent malignant neoplasm, which occurs almost exclusively in the liver or spleen and may arise from a common EBV-infected mesenchymal cell that differentiates along the follicular or fibroblastic dendritic cell pathway. Despite its rarity, it presents a pressing need for an improved understanding of its genetic underpinnings and potential treatment strategies for recurrent or disseminated cases. To address this, we conducted comprehensive whole-exome sequencing and transcriptome sequencing (mRNA-seq) analyses on 31 and 6 cases of EBV+ IFDCS, respectively, collected from multiple centers in China. We also compared the genetic features of EBV+ IFDCS with those of other EBV-associated malignancies. Our analyses revealed a relatively high somatic mutation rate and widespread copy number variations affecting the major histocompatibility complex-I/II in EBV+ IFDCS. Integrated mutational profiling identified key signaling pathways involved in epigenetic regulation, NF-κB signaling, RTK/RAS/PI(3)K, and the Hippo pathway. Furthermore, we identified several frequently altered genes that could serve as potential therapeutic targets in EBV+ IFDCS. Transcriptomic analysis unveiled significant upregulation of pathways related to virus infection, immune responses, and multiple immune checkpoint genes in EBV+ IFDCS. Comparative analysis demonstrated clear genetic distinctions between EBV+ IFDCS and other EBV-associated tumors. In conclusion, our study provides comprehensive insights into the unique genomic and transcriptomic landscape of EBV+ IFDCS. We have identified multiple genetic alterations that likely contribute to the development and progression of this malignancy. Our results suggest that targeted therapy and immune checkpoint inhibitors may hold promise as potential therapeutic approaches for patients with recurrent or disseminated EBV+ IFDCS.

Humans

Discovery of novel diagnostic biomarkers of hepatocellular carcinoma associated with immune infiltration.

OBJECTIVE: Diagnosis of hepatocellular carcinoma (HCC) remains challenging for clinicians. Machine learning approaches and big data analyses are viable strategies for identifying HCC diagnostic markers. MATERIALS AND METHODS: In this study, we downloaded mRNA expression profiles of HCC from the GEO database and used random forest and machine learning algorithms, such as least absolute shrinkage and selection operator, to screen for reliable diagnostic genes. Disease Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Set Enrichment Analysis enrichment analyses were performed to explore differential gene functions and disease pathways. CIBERSORT was performed to calculate the immune cell infiltration of HCC and the correlation between diagnostic genes and immune cells. Cell experiments were performed to evaluate the function of R-spondin 3 (RSPO3) in HCC cells. Immunohistochemical staining was used to evaluate the protein expression of CD138, CD206 and iNOS. RESULTS: The results indicated that extracellular matrix protein 1 (ECM1), Niemann-Pick C1-Like 1 (NPC1L1) and RSPO3 were down-regulated in HCC compared with the normal group (p&#x2009;<&#x2009;0.05), which was validated in clinical tissue samples. Moreover, ECM1, NPC1L1 and RSPO3 had high diagnostic values (AUC > 0.75) for HCC in both training and test groups. Immuno-infiltration analysis revealed that ECM1 and RSPO3 were highly positively correlated with neutrophil and macrophage M2 levels, whereas they were negatively correlated with Tregs. RSPO3-si affected cell proliferation and apoptosis in HCC. Furthermore, RSPO3 exhibited a positive correlation with tumour progression, the proportion of plasma cells and M2 macrophages in mice, while showing a negative association with M1 macrophages. CONCLUSION: The present study identified ECM1, NPC1L1 and RSPO3 as new diagnostic biomarkers for HCC based on normal and diseased samples from HCC, meanwhile the pro-oncogenic function of RSPO3 and its regulation on immune infiltration have been confirmed.

Carcinoma, Hepatocellular

SloR-SRE binding to the S. mutans mntH promoter is cooperative.

UNLABELLED: Streptococcus mutans is a commensal member of the plaque microbiome. It is especially prevalent when dietary sugars are available for S. mutans fermentation, generating acid byproducts that lower plaque pH and foster tooth decay. S. mutans can survive in the transient conditions of the mouth, in part because it can regulate the uptake of manganese and iron during periods of feast when metal ions are available, and famine when they are limited. S. mutans depends on a 25kDa metalloregulatory protein, called SloR, to modulate the uptake of these cations across the bacterial cell surface. When bound to manganese, SloR binds to palindromic recognition elements in the promoter of the sloABC genes that encode the major manganese transporter in S. mutans. Reports in the literature describe MntH, an ancillary manganese transporter in S. mutans, that is also subject to SloR control. In the present study, we performed expression profiling experiments that reveal coordinate regulation of the sloABC and mntH genes at the level of transcription. In addition, we describe a role for the mntH gene product that is redundant with that of the sloABC-encoded metal ion uptake machinery. The results of DNA-binding studies support direct SloR binding to the mntH promoter region which, like that at the sloABC promoter, harbors three palindromic recognition elements to which SloR binds cooperatively to repress downstream transcription. These findings expand our understanding of the SloR metalloregulome and elucidate SloR-DNA binding that is essential for S. mutans metal ion homeostasis and fitness in the oral cavity. IMPORTANCE: Dental caries disproportionately impacts low-income socioeconomic groups in the United States and abroad. Research that is focused on S. mutans, the primary causative agent of dental caries in humans, is significant to mitigation efforts aimed at alleviating or preventing dental caries. The SloR protein is a major regulator of the S. mutans metal ion uptake machinery encoded by the sloABC- and mntH genes. This SloR-mediated gene control is essential for maintaining intracellular metal ion homeostasis, and hence S. mutans fitness in the plaque microbiome. An improved understanding of the sloABC and mntH metal ion transporters and their regulation by SloR can guide rational drug design that, by targeting the SloR-DNA-binding interface, can alleviate or prevent S. mutans-induced disease.

Streptococcus mutans