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Biomedical subjects

Li Zhu

Publications and source records attributed to Li Zhu.

9 recordsLinked to original sources

Development of a Recombinant Adeno-Associated Virus Vector for Human T Lymphocyte- and Natural Killer Cell-Targeted Gene Therapy.

Recombinant adeno-associated virus (rAAV) vectors are widely used for gene delivery but show limited efficiency in immune cells, including T lymphocytes and natural killer (NK) cells. To overcome this barrier, we have developed a CD7-targeted rAAV vector (CD7-AAV6/9) featuring a nanobody-fused hybrid capsid derived from a rationally selected chimeric combination of AAV6 and AAV9. CD7-AAV6/9 enables efficient and selective transduction of immortalized and primary human T and NK cells in vitro and in vivo in a humanized mouse model, achieves high production titers, and exhibits markedly reduced off-target transduction compared with wild-type serotypes. Incorporation of a human gene-derived intron into the vector genome to overcome host-mediated transcriptional repression enables robust transgene expression in human CD7+ T lymphocyte and NK cell populations. Together, our findings establish an integrated capsid-genome design framework for targeting human T and NK cells, notoriously challenging immune cell populations for gene therapy, and provide a versatile platform readily adaptable to alternative surface markers and therapeutic payloads.

NK cells

Associations between gut microbiota on carcass traits and meat quality in Neijiang pigs, Yorkshire pigs, and their hybrids.

This study was designed as an exploratory analysis to compare carcass performance, meat quality traits, and gut microbiota of Neijiang pigs (NN), Yorkshire pigs (YY), and Yorkshire &#xd7; Neijiang hybrid pigs (YN), with the goal of generating testable hypotheses regarding potential links between gut microbial composition and production phenotypes. Compared with NN pigs, YN hybrids exhibited improved carcass performance while inheriting the favorable meat quality characteristics of Neijiang pigs. The results of 16S rRNA sequencing analysis showed that the relative abundance of the microbiota was similar to that of NN pigs. LDA effect size (LEfSe) results showed that Streptococcus, Treponema, probable_genus_10 and Fibrobacter were the differentially enriched taxa in YN pigs (p < 0.05). Correlation analysis was performed on carcass, meat quality and intestinal microbiota screened out by LEfSe. The results showed that Akkermansia tended to positively associate with body length and oblique length in YN pigs; Dialister correlated positively with dressing rate and pH45min; Treponema showed positive trends with a*45min and a*24h (p < 0.05). Finally, the correlation network model preliminarily mapped associations among production traits, gut microbiota, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for exploratory screening. Nine core microbial taxa exhibited close correlations with phenotypic indicators, which implied that these microbes might modulate metabolic pathways to shape pig performance. Overall, hybrids inherited superior parental carcass and meat quality but harbored unique gut microbial communities relative to purebreds-these preliminary correlative observations generate new hypotheses that gut microbiota may contribute to heterosis-associated phenotypic advantages, which require further targeted validation.

Animals

Effects of Blood Flow Restriction Training at Different Levels of Arterial Occlusion Pressure on Body Composition and Athletic Performance in Youth Soccer Players: A Randomized Controlled Trial.

This study aimed to investigate the effects of low-load blood flow restriction training (BFRT) performed at different levels of arterial occlusion pressure (AOP) on body composition, maximal strength, and athletic performance in youth soccer players. Twenty-four male youth soccer players were randomly assigned to 40% AOP group, 60% AOP group, or control group. Participants in the BFRT groups performed lower-limb resistance training at 30% of one-repetition maximum (1RM) under the corresponding pressure conditions, whereas the control group trained without BFR. Training was conducted three times per week for six weeks. Body composition, back squat 1RM, countermovement jump (CMJ), T-test, and 30-m sprint performance were assessed before and after the intervention. Results showed that lower-limb muscle mass increased significantly in both the 40% AOP group (mean change = 0.55 kg, 95% CI: 0.13 to 0.97 kg, P = 0.010) and the 60% AOP group (mean change = 0.83 kg, 95% CI: 0.37 to 1.29 kg, P < 0.001), with the 60% AOP group showing significantly greater gains than the control group (between-group difference = 1.48 kg, 95% CI: 0.40 to 2.56 kg, P = 0.008). Back squat 1RM improved significantly in both the 40% AOP group (mean change = 6.50 kg, 95% CI: 3.90 to 9.10 kg, P < 0.001) and the 60% AOP group (mean change = 9.25 kg, 95% CI: 6.75 to 11.75 kg, P < 0.001), with the 60% AOP group demonstrating superior strength gains compared with the 40% AOP group (between-group difference = 2.94 kg, 95% CI: 0.20 to 5.68 kg, P = 0.048). CMJ height and T-test performance improved significantly in both the 40% AOP group (CMJ: mean change = 2.07 cm, 95% CI: 0.80 to 3.34 cm, P = 0.002; T-test: mean change = -0.23 s, 95% CI: -0.35 to -0.11 s, P = 0.001) and the 60% AOP group (CMJ: mean change = 2.65 cm, 95% CI: 1.00 to 4.30 cm, P = 0.003; T-test: mean change = -0.26 s, 95% CI: -0.38 to -0.14 s, P < 0.001), with no significant differences between the two BFRT groups (all P > 0.05). No significant changes were observed in 30-m sprint performance across groups (all P > 0.05). This study showed that six weeks of low-load (30% 1RM) blood flow restriction training performed at both 40% and 60% AOP was associated with improvements in lower-limb muscle mass, squat strength, and selected aspects of athletic performance in youth soccer players, compared with low-load training without BFR. While both pressure levels elicited comparable improvements in CMJ and agility performance, training at 60% AOP was associated with greater adaptations in lower-limb muscle mass and squat strength, with no additional benefits observed for 30-m sprint performance.

Humans

NS2A V89F mutation in a DENV1 clinical isolate enhances neurotropism and neuroinvasion.

INTRODUCTION: Dengue virus (DENV) neurological complications are increasingly reported, yet the viral genetic determinants of neurotropism remain poorly characterized. METHODS: We screened 25 DENV1 clinical isolates from the 2014 outbreak in Guangdong, China, for neurotropism in suckling mice, and integrated comparative genomics, pre-expression functional assays, population-scale sequence analysis, and OpenFold3 structural modeling to identify mutations associated with enhanced neuroinvasion. RESULTS: We found that only strain P1253 induced neurological symptoms and mortality via subcutaneous inoculation, producing cortical-selective lesions distinct from the diffuse encephalitic damage observed after intracranial inoculation, and P1253 replicated preferentially in human brain microvascular endothelial cells (HBMEC) compared to contemporaneous strains. Comparative genomics identified three unique mutations in P1253 (NS1 175Y&#x2192;H, NS2A 89V&#x2192;F, NS4A 2V&#x2192;I), and pre-expression assays demonstrated that only NS2A 89V&#x2192;F significantly enhanced viral replication and cytopathic effect in HBMEC. Analysis of 1,990 complete DENV1 genomes revealed five natural mutant types in the NS2A 89 -96 residue region, with P1253 representing the FIPI quadruple-mutant type, and OpenFold3 structural prediction showed that 89V&#x2192;F introduced on the VIPI background induced the most significant distal domain reorientation (RMSD 1.605 &#xc5;), increasing the centroid-to-centroid distance between residues 89 -96 and 185 -218 from 18.221 &#xc5; to 27.462 &#xc5;. DISCUSSION: These findings identify NS2A 89V&#x2192;F as a candidate adaptive mutation associated with enhanced neurotropism in DENV1 and provide a framework for monitoring neurovirulent variants.

Dengue Virus

tRNA methylation: functional insights and epitranscriptomic regulation.

tRNAs, one of the most conserved and abundant RNAs, are central components of protein synthesis, transferring genetic information from DNA to proteins through a precise base-pairing mechanism. Post-transcriptional modifications of tRNAs by tRNA modifying enzymes are essential for maintaining their normal physiological functions, including methylation, isomerization and glycosylation. tRNA methylation, particularly 1-methyladenosine (m1A), 5-methylcytidine (m5C), and 7-methylguanosine (m7G), are among the most abundant and diverse types of post-transcriptional modifications of tRNA, which promote the stability of tRNA secondary and tertiary structures and allow for proper translation. In addition, tRNA methylation affects the production and function of tsRNA (tRNA-derived small RNA), small fragments of RNA that further regulate gene expression and protein synthesis. In our review, we discuss the relevant biological functions of tRNA methylation, including tRNA stability, protein translation, and tsRNA biogenesis.

RNA, Transfer

Identification of key genes related to bone metastasis of breast cancer using bioinformatics methods and construction of a prognostic model.

Breast cancer (BC) ranks among the most prevalent cancers in females, with bone metastasis significantly compromising patients' quality of life and survival rates. Enhancing our comprehension of BC bone metastasis mechanisms at the molecular level holds promise for improving BC treatment and prognosis. Leveraging bioinformatics tools, we integrated multiple datasets, conducted comprehensive analyses across various databases, identified biomarkers associated with BC bone metastasis, and constructed a prognostic model. Firstly, 3 BC bone metastasis-related datasets were downloaded from gene expression omnibus, the data were merged, and batch effects were removed, followed by identification of differentially expressed genes (DEGs). Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the DEGs. A protein-protein interaction network was constructed using the STRING database to screen hub genes. Then, survival analysis of hub genes was performed using the Cancer Genome Atlas (TCGA) database. A prognostic model was constructed using key genes with survival differences, and the model was evaluated. Two hundred ninety-two DEGs were identified. Gene ontology and KEGG pathway enrichment analysis yielded 769 biological processes (BPs), 78 cellular components, 43 molecular functions, and 50 KEGG pathways. Fifteen hub genes were selected from the protein-protein interaction network. Survival analysis revealed 6 genes related to BC survival. The prognostic model identified 4 genes with important predictive value for BC prognosis. Our study utilized bioinformatics analysis to identify a series of DEGs related to BC bone metastasis. Based on further selection of hub genes, we constructed a relatively ideal prognostic model for BC, and identified 4 genes (DLGAP5, TPX2, PLK1, and CENPN) with valuable predictive value for BC prognosis.

Humans

Association between residential greenness and coronary heart disease: A proteomics and miRNA microarray analysis.

Greenness has been linked to cardiovascular disease. However, the specific biological mechanisms through which greenness impacts coronary heart disease (CHD) remain unclear. We aim to explore the underlying epigenetic mechanisms linking greenness and CHD by using proteomics and miRNA microarray. A total of 2387 participants were included in the population study, 816 of whom were diagnosed with CHD. Residential greenness exposure was characterized using the normalized difference vegetation index (NDVI). Generalized additive models and restricted cubic splines investigated the association between greenness and CHD. Mediation analysis examined whether cardiovascular metabolic risk factors (blood pressure, inflammation indicators, and glucose) mediated the association. After proteomics and miRNA microarray screening, Elisa and qRT-PCR validated selected proteins (THBS1, FCN3, and LTBP1) and miRNAs (miR-671-5p, miR-124-3p, and miR-379-5p) in CHD. Among these, LTBP1 and miR-379-5p showed significant differential expression (P&#xa0;<&#xa0;0.05) and were examined as potential molecular mediators. Higher greenness exposure within a 1000-m area was associated with a lower risk of CHD (OR: 0.86, 95&#xa0;% CI: 0.81, 0.92). Systolic blood pressure (6.32&#xa0;% [95&#xa0;% CI: 1.49&#xa0;%, 13.12&#xa0;%]), lymphocyte (10.98&#xa0;% [95&#xa0;% CI: 3.76&#xa0;%, 22.00&#xa0;%]), monocyte (9.94&#xa0;% [95&#xa0;% CI: 3.42&#xa0;%, 20.87&#xa0;%]), and fasting blood glucose (3.41&#xa0;% [95&#xa0;% CI: 0.56&#xa0;%, 7.84&#xa0;%]) mediated this association. LTBP1 and miR-379-5p were differentially expressed in CHD and mediated 7.19&#xa0;% [95&#xa0;% CI: 0.01&#xa0;%, 23.37&#xa0;%] and 20.03&#xa0;% [95&#xa0;% CI: 2.85&#xa0;%, 69.71&#xa0;%] of greenness effect on CHD, respectively. Combining the population study and experiments, we found that miR-379-5p and LTBP1 may jointly modulate vascular constriction and immune inflammation in the association between greenness and CHD.

Humans

Differences of clinical features, prognosis and genetic mutations in Chinese patients with malignant melanoma and additional primary tumours.

BACKGROUND: The differences in the clinical features, prognosis and genetic mutations in Chinese patients with malignant melanoma (MM) and additional primary tumours remain unclear. METHODS: A retrospective analysis was conducted on patients with malignancies in Fujian Cancer Hospital from January 2007 to September 2022, end follow-up in September 2023. Clinical data were gathered, survival analysis was performed, and genetic mutations were detected. RESULTS: There were 58 of 1223 melanoma patients with melanoma and additional primary tumours, an incidence of 4.74%. Acral MM was the most common subtype (26/58), 23 (39.66%) patients had concomitant digestive tumours. Patients who had MM as their first primary tumour (MMFP) had shorter tumour occurrence intervals (9.93 vs. 57.78&#xa0;months, p&#xa0;=&#xa0;.008) but longer melanoma survival (MM-OS) than the non-MMFP group (100.43 vs. 18.93&#xa0;months, p&#xa0;=&#xa0;.015). Patients with cancer family histories were more likely to have pathogenic and likely pathogenic (P/LP) mutations (2/5 vs. 4/25). The somatic BRAF gene mutation was frequently observed in MM tissue (8/19, 42.11%). Three patients had whole-genome doubling and microsatellite instability-high (MSI-H). The COSMIC2 signature 3 was significantly higher in the P/LP group. CONCLUSIONS: The frequency of MM and additional primary tumours is about 5% in Chinese populations. Patients with melanoma diagnosed first have longer melanoma survival. Digestive system tumours were the most concomitant; a digestive examination is advisable, especially for those with an expected overall survival (OS) greater than 10&#xa0;months. Meanwhile, patient's family cancer history should be followed up in detail, along with completion of germline P/LP mutation and somatic mutation testing, all of which may provide valuable support for further treatment.

Adult

Structure-function relationship of ASH1L and histone H3K36 and H3K4 methylation.

The histone H3K36-specific methyltransferase ASH1L plays a critical role in development and is frequently dysregulated in human diseases, particularly cancer. Here, we report on the biological functions of the C-terminal region of ASH1L encompassing a bromodomain (ASH1LBD), a plant homeodomain (ASH1LPHD) finger, and a bromo-adjacent homology (ASH1LBAH) domain, structurally characterize these domains, describe their mechanisms of action, and explore functional crosstalk between them. We find that ASH1LPHD recognizes H3K4me2/3, whereas the neighboring ASH1LBD and ASH1LBAH have DNA binding activities. The DNA binding function of ASH1LBAH is a driving force for the association of ASH1L with the linker DNA in the nucleosome, and the large interface with ASH1LPHD stabilizes the ASH1LBAH fold, merging two domains into a single module. We show that ASH1L is involved in embryonic stem cell differentiation and co-localizes with H3K4me3 but not with H3K36me2 at transcription start sites of target genes and genome wide, and that the interaction of ASH1LPHD with H3K4me3 is inhibitory to the H3K36me2-specific catalytic activity of ASH1L. Our findings shed light on the mechanistic details by which the C-terminal domains of ASH1L associate with chromatin and regulate the enzymatic function of ASH1L.

Histones