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Biomedical subjects

Xuan Liu

Publications and source records attributed to Xuan Liu.

8 recordsLinked to original sources

Parenting styles and fertility intention: Mediating effects of childbearing beliefs and psychological resilience.

China's declining fertility rate is partly due to low fertility intention among childbearing population. To understand family influence on young people's fertility intention and its underlying mechanisms, this study examines how parenting styles (authoritarian vs. permissive) affect Chinese college students' fertility intention, with traditional childbearing beliefs and resilience as mediators. Data were collected from 839 participants (Age: M = 21.1, SD = 1.7 years) using structured questionnaires. Logistic regression found that a positive correlation between permissive parenting style and fertility intention, with authoritarian parenting having no impact. Mediation analysis showed the association between permissive parenting style and fertility intention was fully mediated through resilience ( = 0.0, 95%CI = [0.0,0.1]) and greater childbearing beliefs ( = 0.0, 95%CI = [0.0,0.1]). The findings indicate that permissive parenting is related to higher fertility intention in youth via resilience and childbearing beliefs. Promoting positive family environments and permissive parenting may enhance childbearing intention.

Humans

Preclinical evaluation of AL-001, a gene therapy for wet age-related macular degeneration.

BACKGROUND: Frequent intravitreal administration of antivascular endothelial growth factor Vascular endothelial growth factor agents remains a major limitation in the management of wet age-related macular degeneration (wAMD). This study evaluated whether suprachoroidal delivery of an engineered recombinant adeno-associated viral (rAAV)-aflibercept vector could achieve sustained, targeted expression with improved efficacy and safety compared with intravitreal administration. METHODS: AL-001, an engineered rAAV vector expressing aflibercept, was developed and characterized. Its expression profile was first assessed in New Zealand white rabbits following suprachoroidal space (SCS) injection. Efficacy, pharmacokinetics, and safety were then evaluated in a nonhuman primate model of laser-induced choroidal neovascularization (CNV), comparing SCS and intravitreal (IVT) administration routes. RESULTS: AL-001 efficiently expressed aflibercept in relevant ocular cells in vitro. In rabbits, SCS administration produced sustained aflibercept levels in ocular tissues. In the nonhuman primate CNV model, a single SCS injection of AL-001 showed favorable efficacy to IVT injection and a notable mild inflammatory response. At week 4, grade IV lesion incidence was 0% (0/48) after SCS administration versus 14.3% (6/42) after IVT administration (absolute difference, -14.3 percentage points; 95% CI, 3.7%-27.8%; P = 0.0258). Throughout follow-up, mean leakage area and grade IV lesion incidence remained 0 with SCS, versus IVT peaks of approximately 0.3 mm2 and 33.0%, respectively, declining to 0.03 mm2 and 2.0% by day 100. Both the medium and high doses decreased pathological vascular leakage and subretinal hyperreflective material. Vector administration preceded laser-induced CNV modeling, demonstrating that sustained intraocular aflibercept expression in the retina and choroid provided durable antiangiogenic protection. Pharmacokinetic analysis confirmed distinct ocular exposure profiles between routes, with viral genomes confined predominantly to the injected eye and no significant systemic accumulation. AL-001 was well tolerated, without sustained intraocular pressure elevation or severe ocular inflammation, and only mild-to-moderate treatment-emergent adverse events. Low pre-existing anti-AAV2 immunity and time-dependent neutralizing antibody responses postdosing, informing a translational model for patient stratification and redosing feasibility. CONCLUSION: Suprachoroidal administration of AL-001 is well tolerated and provides durable, targeted aflibercept expression with pronounced antiangiogenic efficacy. These results support AL-001 as a promising, long-acting therapeutic candidate for wAMD.

AAV

Rational and computation-assisted engineering of a compact and efficient CRISPR-Cas12f genome editor.

The CRISPR-Cas12f system is an ultracompact genome-editing platform, yet only a few orthologs exhibit robust activity in mammalian cells. Here, we systematically screened 23 Cas12f orthologs and identified two active nucleases, PspCas12f1 and TcCas12f1, capable of genome editing in human cells. Single guide RNA (sgRNA) scaffold optimization enhanced the basal activity of PspCas12f1. To further improve its performance, we combined structure-guided rational design with protein language model-assisted filtering. Candidate mutations predicted by SaProt were further screened based on structural proximity to the DNA-binding interface and electrostatic compatibility. This integrative strategy identified Q100R and E293R, whose combination yielded the optimized variant enPspCas12f1. enPspCas12f1 achieved genome-editing efficiencies comparable to SpCas9 across multiple endogenous loci while maintaining high specificity. Collectively, our results demonstrate that integrating protein language model-assisted filtering with structure-guided rational design provides an effective strategy for engineering PspCas12f1 and may facilitate the optimization of additional compact CRISPR nucleases.

CRISPR-Cas12f

Case Report: Early infantile drug-resistant epilepsy and gastrointestinal dysmotility associated with a de novo GNAO1 variant and a 16p13.11 microdeletion.

BACKGROUND: The GNAO1 gene is located on the long arm of chromosome 16 (16q13) and is associated with Developmental and Epileptic Encephalopathy 17. It encodes a protein involved in regulating various neurotransmitters and neuronal growth and development. The 16p13.11 microdeletion is a genomic deletion in the p13.11 region of the short arm of chromosome 16, previously reported to predispose individuals to neurodevelopmental disorders. These two regions do not overlap on the chromosome, and the 16p13.11 microdeletion does not involve the GNAO1 gene locus. CASE PRESENTATION: We reports a 1-month-old infant presenting with concurrent GNAO1 (p. G203R) gene variation and a 16p13.11 microdeletion. The patient initially presented with recurrent abdominal distension in the neonatal period, which gradually progressed to include focal seizures and intractable epileptic spasms. Interictal EEG showed multifocal discharges and burst-suppression patterns. Brain MRI revealed no abnormalities. A full gastrointestinal series suggested intestinal obstruction and gastro-esophageal reflux. Improved whole-exome sequencing identified: 1) A single nucleotide variantion: GNAO1, NM_020988.3:exon6: c.607G > A (p.Gly203Arg). 2) A copy number variation: A pathogenic 1.453 Mb deletion in the 16p13.11 region. CONCLUSIONS: We describe the developmental trajectory of an infant with overlapping features of gastrointestinal symptoms and drug-resistant epilepsy, carrying a GNAO1 variant and a 16p13.11 microdeletion. This case provides insights into the contribution of both single nucleotide variant and copy number variant to the phenotype.

16p13.11 microdeletion

Physiological and molecular responses of coelomocytes to low- to mid-frequency acoustic exposure in the sea urchin Strongylocentrotus intermedius.

Underwater noise is a widespread environmental pollutant in marine ecosystems, yet the effects of low- to mid-frequency acoustic exposure on immune physiology and molecular responses in echinoderms remain unclear. In this study, the sea urchin Strongylocentrotus intermedius was exposed to continuous pure-tone acoustic stimulation at 80, 125, 250, 500, 750, and 1000 Hz for 3 h. Results showed that acoustic exposure significantly affected redox homeostasis, energy metabolism, and immune function in S. intermedius coelomocytes: the antioxidant system and glutathione redox balance were altered, as indicated by increased superoxide dismutase (SOD) and catalase (CAT) activities, elevated reduced glutathione (GSH) content, and a higher GSH/GSSG ratio; glycolysis-related enzyme activities were enhanced, with increased pyruvate kinase (PK) activity under 125-500 Hz exposure and elevated hexokinase (HK) activity at 250 Hz; and immune function was impaired, as shown by increased coelomocyte mortality, reduced phagocytic activity, and inhibited acid phosphatase (ACP) and alkaline phosphatase (AKP) activities, whereas respiratory burst activity showed no significant change. Among all treatments, 250 Hz induced the most pronounced physiological responses. Transcriptomic analysis of coelomocytes from the 250 Hz group identified 663 differentially expressed genes, including 537 upregulated and 126 downregulated genes, mainly enriched in pathways related to apoptosis, phagosome, lysosome, glutathione metabolism, arachidonic acid metabolism, and carbohydrate metabolism. These findings indicate that low- to mid-frequency acoustic exposure can act as a physiological and molecular stressor to S. intermedius coelomocytes by affecting redox homeostasis, enhancing energy metabolism, and suppressing immune effector processes, with 250 Hz showing the strongest effect under the present exposure conditions. This study provides experimental evidence for evaluating the potential biological effects of low- to mid-frequency acoustic exposure on benthic echinoderms.

Animals

Protective effects of seminal exosomes on cryopreserved sperm via inhibiting oxidative damage.

This study aimed to explore the protective effect of seminal plasma exosomes (SPEs) on human sperm structure and function during cryopreservation and its potential mechanism. The samples were divided into two groups: the control group was treated solely with sperm cryoprotectant before freezing, while the exosome group was supplemented with SPEs. After cryopreservation and thawing, sperm progressive motility, normal morphological rate, and survival rate were evaluated. Furthermore, PKH67 labeling experiments were performed, and oxidative stress markers as well as energy metabolism indicators in sperm were detected. Subsequent mechanism exploration was conducted via proteomic analysis and protein validation assays. This work reveals that adding SPEs at a concentration of 1 or 2 mg/ml effectively improves sperm progressive motility after cryopreservation. After supplementing with SPEs, sperm glucose levels are reduced and mitochondrial membrane potential is enhanced. Simultaneously, SPEs alleviate oxidative stress by decreasing reactive oxygen species (ROS) and DNA fragment index (DFI) while increasing superoxide dismutase (SOD) activity. Functional annotation of proteomics reveals that 14 of the differentially expressed proteins (DEPs) are associated with sperm motility. Enriched metabolic pathways related to sperm motility and sperm protein validation experiments indicate that the expression of MAPK, p-MAPK, and p-JNK proteins in sperm is higher in the Exosome group than in the Control group. This study provides important theoretical support for the application of SPEs in mitigating cryopreservation damage to sperm by enhancing antioxidant capacity. The specific mechanism may be mediated by the MAPK/p-JNK pathway.

Male

Effects of aerobic exercise on inflammation and gut microbiota in obese mice: a metagenomic and metabolomic analysis.

BACKGROUND: Aerobic exercise can ameliorate insulin resistance (IR). However, the mechanism by which aerobic exercise regulates the gut microbiome to ameliorate IR and obesity remains unexplored. METHODS: Obese models were established by feeding C57BL/6 male mice a high-fat diet. A total of 26 mice were randomly divided into control group (group A, N&#x2009;=&#x2009;8) and high-fat diet group (HFD group, N&#x2009;=&#x2009;18). Successfully modeled mice were further assigned to model group (group B, N&#x2009;=&#x2009;8) and exercise group (group C, N&#x2009;=&#x2009;8). Group C underwent a 6-week treadmill exercise program (12&#xa0;m/min, 60&#xa0;min per day, 5 days per week). After intervention, colon tissue morphology was observed through hematoxylin-eosin staining, serum lipids and inflammatory indicators levels were detected by ELISA. The changes in the intestinal microbiota of the mice were also examined using metagenomic sequencing and UPLC-MS non-targeted metabolomics. RESULTS: Compared with the group A, the body weight, TC, TG, LDL-C, blood glucose, insulin, and IR in the group B significantly increased (P&#x2009;<&#x2009;0.01), while the levels of pro-inflammatory cytokines TXNIP, TNF-&#x3b1;, NLRP3, IL-1&#x3b2;, and IL-18 significantly increased (P&#x2009;<&#x2009;0.05 or P&#x2009;<&#x2009;0.01). Compared with the group B, aerobic exercise reduced the body weight, TC, blood glucose, insulin, IR, TXNIP, TNF-&#x3b1; and other indicators in obese mice (P&#x2009;<&#x2009;0.05 or P&#x2009;<&#x2009;0.01). Moreover, aerobic exercise can regulate the imbalance of the intestinal flora in obese mice and ameliorate the disorder of metabolites. The metabolic pathways including arachidonic acid metabolism and histidine metabolism showed the most significant differences after the intervention of aerobic exercise. CONCLUSIONS: In conclusion, aerobic exercise can ameliorate glucose and lipid metabolism, IR, inflammatory response, and regulate the intestinal microecology and metabolic disorders in obese mice. The mechanism may be closely related to enhancing the diversity of intestinal flora, regulating the metabolism of arachidonic acid and histidine.

Animals

The evolutionary trajectories and gene regulatory roles of nuclear-integrated plastid DNA: clues for enhancing environmental adaptation in Caryophyllales.

Environmental stimuli can induce the transfer of chloroplast DNA to the nuclear genome, resulting in nuclear-integrated plastid DNAs (NUPTs). However, their role in plant adaptability remains unclear. Species within the Caryophyllales order, known for their adaptation to extreme environments, provide an ideal model for studying the evolutionary dynamics and functions of NUPTs. In this study, we analyzed NUPTs in 24 Caryophyllales species to investigate their evolution and regulatory roles in gene expression, particularly in response to environmental stimuli. We found significant interspecies variation in NUPT abundance, ranging from 566 insertions in Amaranthus cruentus to 3585 in Beta vulgaris, with sizes spanning from 100&#x2009;bp to over 100&#x2009;kb. Approximately 62% of NUPTs were inserted within the last 20&#x2009;million years, while some species exhibit insertion peaks dating back 49&#x2009;million years. NUPT presence/absence polymorphisms in six related species suggest that NUPT insertions and deletions are dynamic processes influenced by phylogeny. NUPTs predominantly integrate into intergenic regions but also insert into genes and promoters, with certain regions acting as hotspots. Notably, NUPTs introduce numerous environmental-responsive cis-acting elements in promoter regions. Genes with NUPT insertions in their promoters are significantly enriched for functions related to environmental response. Further luciferase assays in Spinacia oleracea demonstrated that NUPT insertions can regulate the expression of genes related to environmental responses, indicating their potential role in adaptive evolution. Overall, our study provides insights into NUPT evolution and their influence on gene function and plant adaptability to environmental stimuli.

Plastids