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Biomedical subjects

Nan Liu

Publications and source records attributed to Nan Liu.

7 recordsLinked to original sources

PSMA6 drives non-small cell lung cancer progression by stabilizing NEDD8 and activating NF-κB signaling.

BACKGROUND: Non‑small cell lung cancer (NSCLC) is a major cause of cancer‑associated death globally. Elucidating novel molecular drivers is essential for targeted therapy development. This study sought to investigate the function and regulatory mechanism of proteasome 20S subunit alpha 6 (PSMA6) in NSCLC. METHODS: Proteasome 20S subunit alpha 6 (PSMA6) expression in NSCLC tissues and cells was analyzed using The Cancer Genome Atlas (TCGA) datasets, immunohistochemistry, and Western blotting. Gain- and loss-of-function assays were performed to evaluate its biological functions. Protein interaction assays and functional rescue experiments were conducted to investigate the underlying mechanisms. RESULTS: We found that PSMA6 was significantly upregulated in NSCLC tissues and cell lines and was associated with poor patient prognosis. Functional experiments demonstrated that PSMA6 promoted NSCLC cell proliferation and migration. Mechanistically, PSMA6 activated nuclear factor kappa B (NF-κB) signaling by enhancing p65 nuclear translocation and IκBα phosphorylation. Further investigation revealed that PSMA6 directly interacted with neural precursor cell expressed, developmentally down-regulated 8 (NEDD8) and increased its protein stability without affecting its mRNA level. Importantly, NEDD8 knockdown abolished PSMA6-induced NF-κB activation and malignant phenotypes, confirming that PSMA6 exerts its oncogenic effects through the NEDD8/NF-κB axis. CONCLUSIONS: Our findings identify a novel PSMA6/NEDD8/NF-κB regulatory axis that promotes NSCLC progression and suggest PSMA6 as a potential therapeutic target.

Proteasome 20S subunit alpha 6 (PSMA6)

Disentangling oscillatory and aperiodic neural activity in autism: A spectral parameterization analysis of neurofeedback intervention.

BACKGROUND: Autism Spectrum Disorder (ASD) is characterized by atypical neural oscillations and heterogeneous alterations in excitation/inhibition (E/I) balance, the directionality of which varies across individuals, neural circuits, and developmental stages. While Alpha-band neurofeedback (NFB) is a promising intervention, its underlying neurophysiological mechanisms remain unclear, partly due to the conflation of periodic and aperiodic signals in traditional EEG analysis. METHODS: This randomized controlled trial recruited 40 children with ASD, assigned to either an experimental group (Alpha-training NFB) or a no-feedback group. Resting-state EEG and behavioral assessments (SRS, ABC) were collected pre- and post-intervention. We employed spectral parameterization to decompose neural activity into aperiodic (1/f slope, offset) and periodic (periodic alpha power, center frequency) components. RESULTS: NFB training yielded significant behavioral improvements in social cognition and relating skills. Physiologically, the experimental group exhibited a significant steepening of the aperiodic slope (increased exponent), reflecting a reduction in neural noise and potential optimization of inhibitory modulation. Furthermore, we observed enhanced periodic alpha power and an acceleration of the alpha center frequency (ACF), indicative of improved neural efficiency and maturation. These physiological shifts in frontal and occipital regions were significantly correlated with improvements in behavioral scores. CONCLUSION: Alpha-training NFB was associated with improvements in caregiver-rated behavioral scores and modulated spectral features of resting-state EEG in children with ASD. These findings validate the utility of spectral parameterization markers in evaluating neuromodulatory interventions.

Humans

Comprehensive analysis of mRNA-microRNA-lncRNA expression profiles in post-traumatic elbow heterotopic ossification using RNA sequencing and experimental validation.

BACKGROUND: This study aimed to profile the molecular signatures of post-traumatic elbow heterotopic ossification (HO) to identify key regulators and potential therapeutic targets. METHODS: Total RNA from post-traumatic elbow HO tissues (n=4) and normal bone tissues (n=6) was subjected to high-throughput sequencing to identify differentially expressed mRNAs (DEGs), microRNAs (DEMs), and lncRNAs (DELs). Bioinformatics analyses included Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, protein-protein interaction network construction, and transcription factor (TF)-microRNA-mRNA network analysis. The expression trends of four most upregulated and four most downregulated DEGs were validated by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: We identified 2,138 DEGs, 40 DEMs, and 905 DELs. DEGs were significantly enriched in biological process "bone mineralization," cellular component "plasma membrane," molecular function "integrin binding," and pathways including PI3K-Akt, NF-κB, JAK-STAT, and TNF signaling pathways. Hub genes with high connectivity included MMP9, IL6, MMP3, CTSK, and BGLAP. Integrated network analysis highlighted the transcription factor JUN and key microRNAs (hsa-miR-124-3p, hsa-miR-548c-3p, and hsa-miR-135b). The qRT-PCR results confirmed the expression trends of selected DEGs. CONCLUSIONS: This study, for the first time, profiled the differentially expressed mRNAs, microRNAs, and lncRNAs in post-traumatic elbow HO using high-throughput RNA sequencing. These findings provide valuable insights into the molecular mechanisms of HO following elbow trauma. The identified hub genes (MMP9, IL6, MMP3, CTSK, and BGLAP), key TF (JUN), and key microRNAs (hsa-miR-124-3p, hsa-miR-548c-3p, and hsa-miR-135b) may serve as potential therapeutic targets for preventing and treating post-traumatic elbow HO.

Humans

BCKDHA-BCKDHB digenic gene therapy restores metabolic homeostasis in two mouse models and a calf with classic maple syrup urine disease.

Classic maple syrup urine disease (MSUD) results from biallelic mutations in genes that encode the branched-chain α-ketoacid dehydrogenase E1α (BCKDHA), E1β (BCKDHB), or dihydrolipoamide branched-chain transacylase (DBT) subunits, which interact to form the mitochondrial BCKDH complex that decarboxylates ketoacid derivatives of leucine, isoleucine, and valine. MSUD is an inborn error of metabolism characterized by recurrent life-threatening neurologic crises and progressive brain injury that can only be managed with an exacting prescription diet or allogeneic liver transplant. To develop a gene replacement therapy for MSUD, we designed a dual-function recombinant adeno-associated virus serotype 9 (rAAV9) vector to deliver codon-optimized BCKDHA and BCKDHB (rAAV9.hA-BiP-hB) to the liver, muscle, heart, and brain. rAAV9.hA-BiP-hB restored coexpression of BCKDHA and BCKDHB as well as BCKDH holoenzyme activity in BCKDHA-/- HEK293T cells and did not perturb physiologic branched-chain amino acid homeostasis in wild-type mice at a systemic dose of 2.7 × 1014 vector genomes per kilogram. In two models of severe MSUD (Bckdha-/- and Bckdhb-/- mice) and a newborn calf homozygous for BCKDHA c.248C>T, one postnatal injection prevented perinatal death, normalized growth, restored coordinated expression of BCKDHA and BCKDHB in the skeletal muscle, liver, heart, and brain, and stabilized MSUD biomarkers in the face of high protein ingestion. In summary, we developed a one-time BCKDHA-BCKDHB systemic dual-gene replacement strategy that holds promise as a therapeutic alternative to prescription diet and liver transplant for treatment of MSUD types 1A and 1B, the two most common forms of MSUD in humans.

Animals

Multi-omics analyses provide insights into the molecular basis for salt tolerance of Phyla nodiflora.

The perennial herbaceous plant, Phyla nodiflora (Verbenaceae), which possesses natural resistance to multiple abiotic stresses, is widely used as a pioneer species in island ecological restoration. Due to the lack of information about its genome, the mechanism underlying its tolerance to environmental stresses, such as salinity, is almost entirely unknown. Here, we report on the high-quality genome of P. nodiflora that is 403.07 Mb in size, and which was assembled and anchored onto 18 pseudo-chromosomes. Genomic synteny revealed that P. nodiflora underwent two whole genome duplication events, which promoted the expansion of genes related to environmental adaptation and the biosynthesis of secondary metabolites. An integrated genomic and transcriptomic analysis suggested that salt stress tolerance in P. nodiflora is associated with the expansion and activated expression of genes related to abscisic acid (ABA) homeostasis and signaling. The expansion of ZEP family genes may contribute to the consistent increase in ABA levels under salt stress. Lysine acetylomic analysis revealed that exposure to salt led to widespread protein deacetylation, with these proteins primarily involved in signal transduction, carbohydrate transport and metabolism, and transcription regulation. Deacetylation of glutathione S-transferase increased enzymatic activities in response to salt-induced oxidative stress. Collectively, the genomic, transcriptomic, and lysine acetylomic analyses provide profound insight into the molecular basis of the adaptation of P. nodiflora to salt stress, and will be helpful to engineer salt-tolerant plants for ecological restoration.

Salt Tolerance

Refining the genetic diagnostic puzzle: A case report on a Chinese ARPKD patient with a reciprocal balanced translocation and c.2507 T > C (p.V836A) in PKHD1.

INTRODUCTION: Autosomal recessive polycystic kidney disease (ARPKD) ranks among the most severe chronic kidney diseases (CKD). Its primary cause is variants in the Polycystic Kidney and Hepatic Disease 1 gene (PKHD1). The clinical spectrum of ARPKD varies widely, ranging from mild late-onset symptoms to severe perinatal mortality. However, achieving an early genetic diagnosis in ARPKD patients before clinical symptoms appear proves challenging. CASE PRESENTATION: This case is a 4-year-old boy who experienced a convulsion characterized by a generalized tonic attack lasting approximately 3-5 minutes and later sought treatment to our hospital. However, routine abdominal ultrasound examination accidentally detected that he had diffuse liver lesions, splenomegaly, and bilateral renal enlargement with renal pelvis dilation. Given the uncertainty regarding the underlying cause of the patient's structural abnormalities and convulsions, karyotyping, whole exome sequencing (WES), structural variant analysis (SV analysis) of whole genome sequencing (WGS) were recommended. The result of SV analysis revealed that he has an RBT impacting PKHD1 and the precise location of breakpoints was confirmed through Long-Range Polymerase Chain Reaction (LR-PCR). However, WES did not screen out pathogenic variants initially, the WES data was reviewed subsequently based on SV analysis results. CONCLUSION: We identified an infrequent variant combination, c.2507T>C (p.V836A) in PKHD1 and an RBT with broken PKHD1, which extends the genetic spectrum of ARPKD, and provide a basis for further genetic counselling to the family.

Humans

LINC00887 promotes GCN5-dependent H3K27cr level and CRC metastasis via recruitment of YEATS2 and enhancing ETS1 expression.

Recent observations have revealed upregulation of H3K27cr in colorectal cancer (CRC) tissues; however, the underlying cause remains elusive. This study aimed to investigate the mechanism of H3K27cr upregulation and its roles in CRC metastasis. Clinically, our findings showed that H3K27cr served as a highly accurate diagnostic marker to distinguish CRC tissues from healthy controls. Elevated levels of LINC00887 and H3K27cr were associated with a poorer prognosis in CRC patients. Functionally, LINC00887 and H3K27cr facilitated the migration and invasion of CRC cells. Mechanistically, LINC00887 interacted with SIRT3 protein. Overexpressed of LINC00887 obstructed the enrichment of SIRT3 within GCN5 promoter, thereby elevating H3K27ac but not H3K27cr level within this region, subsequently activating GCN5 expression. This activation increased the global level of H3K27cr, promoting the enrichment of GCN5, H3K27cr, and YEATS2 within ETS1 promoter, activating ETS1 transcription and ultimately promoting the metastasis of CRC. The in vivo study demonstrated that inhibition of LINC00887 suppressed CRC metastasis, but this inhibitory effect was nullified when mice were treated with NaCr. In conclusion, our results confirmed the diagnostic biomarker potential of H3K27cr in individuals with CRC, and proposed a functional model to elucidate the involvement of LINC00887 in promoting CRC metastasis by elevating H3K27cr level.

Humans