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Biology subjects

ZHAO, L.

Publications and source records attributed to ZHAO, L..

4 recordsLinked to original sources

Elucidating the potential carcinogenic molecular mechanisms of parabens in head and neck squamous cell carcinoma through network toxicology and molecular docking

ObjectiveThis study aims to systematically investigate the molecular mechanisms through which parabens may contribute to head and neck squamous cell carcinoma (HNSCC) carcinogenesis using integrated network toxicology and molecular docking. Materials and MethodsSix commonly used parabens (ethyl-, propyl-, methyl-, heptyl-, butyl-, and benzylparaben) were selected for toxicity prediction via ProTox 3.0 and ADMETlab2.0. Their potential targets were retrieved from Swiss Target Prediction, ChEMBL, and the Similarity Ensemble Approach (SEA). HNSCC-related targets were collected from GeneCards, OMIM, and CTD, while differentially expressed genes (DEGs) were identified using TCGA-HNSC data. Functional enrichment, protein-protein interaction (PPI) network construction, hub gene identification, molecular docking, and immune infiltration analyses were performed using DAVID, STRING, Cytoscape, CB-DOCK2, and TIMER2.0. ResultsWe identified 80 common targets through which parabens may exert toxic effects in HNSCC. Among these, 12 hub genes (CCNB1, CDK1, CCNA2, CDK2, CDK4, TYMS, AURKA, CCNA1, CHEK1, CCNB2, PLK1, CDC25A) were significantly overexpressed in HNSCC tissues and were primarily enriched in cell cycle regulation, p53 signaling, and viral carcinogenesis pathways. CCNA1 was further validated as an independent prognostic factor associated with poor survival. Molecular docking revealed strong binding affinities between parabens and hub proteins. Immune infiltration analysis indicated a negative correlation between CCNA1 expression and CD8+ T cell and B cell infiltration. ConclusionsParabens may promote HNSCC progression by disrupting cell cycle regulation and immune responses via direct interactions with key hub genes. These findings provide a novel mechanistic basis for the carcinogenic potential of parabens in HNSCC and underscore the need for further experimental and epidemiological validation.

pharmacology and toxicology↗

The fully activated open state of KCNQ1 controls the cardiac 'fight-or-flight' response

The cardiac KCNQ1+KCNE1 (IKs) channel regulates heart rhythm in both normal and stress conditions. Under stress, the {beta}-adrenergic stimulation elevates the intracellular cAMP level, leading to KCNQ1 phosphorylation by protein kinase A and increased IKs, which shortens action potentials to adapt to accelerated heart rate. An impaired response to the {beta}-adrenergic stimulation due to KCNQ1 mutations is associated with the occurrence of a lethal congenital long QT syndrome (type 1, also known as LQT1). However, the underlying mechanism of {beta}-adrenergic stimulation of IKs remains unclear, impeding the development of new therapeutics. Here we find that the unique properties of KCNQ1 channel gating with two distinct open states are key to this mechanism. KCNQ1s fully activated open (AO) state is more sensitive to cAMP than its intermediate open (IO) state. By enhancing the AO state occupancy, the small molecules ML277 and C28 are found to effectively enhance the cAMP sensitivity of the KCNQ1 channel, independent of KCNE1 association. This finding of enhancing AO state occupancy leads to a potential novel strategy to rescue the response of IKs to {beta}-adrenergic stimulation in LQT1 mutants. The success of this approach is demonstrated in cardiac myocytes and also in a high-risk LQT1 mutation. In conclusion the present study not only uncovers the key role of the AO state in IKs channel phosphorylation, but also provides a new target for anti-arrhythmic strategy. Significance statementThe increase of IKs potassium currents with adrenalin stimulation is important for "fight-or-flight" responses. Mutations of the IKs channel reducing adrenalin responses are associated with more lethal form of the type-1 long-QT syndrome (LQT). The alpha subunit of the IKs channel, KCNQ1 opens in two distinct open states, the intermediate-open (IO) and activated-open (AO) states, following a two-step voltage sensing domain (VSD) activation process. We found that the AO state, but not the IO state, is responsible for the adrenalin response. Modulators that specifically enhance the AO state occupancy can enhance adrenalin responses of the WT and LQT-associated mutant channels. These results reveal a mechanism of state dependent modulation of ion channels and provide an anti-arrhythmic strategy.

biophysics↗

The heterogeneity and effect of diabetes and hypertension on spectral characteristics of vasomotion

Vasomotion refers to the spontaneous oscillation of blood vessels within a frequency range of 0.01 to 1.6 Hz. Various disease states, including hypertension and diabetes, have been associated with alterations in vasomotion at the finger, indicating potential impairment of skin microcirculation. Due to the non-linear nature of human vasculature, the modification of vasomotion may vary across different locations for different diseases. In this study, Laser Doppler Flowmetry was used to measure blood flow motion at acupoints LU8, LU5, SP6, and PC3 among 49 participants with or without diabetes and/or hypertension. Fast Fourier Transformation was used to analyze noise type while Hilbert-Huang Transformation and wavelet analysis were applied to assess Signal Noise Ratio (SNR) results. Statistical analysis revealed that different acupoints exhibit distinct spectral characteristics of vasomotion not only among healthy individuals but also among patients with diabetes and hypertension. The results showed strong heterogeneity of vasomotion among blood vessels, indicating that the vasomotion measured at a certain point may not reflect the real status of microcirculation.

bioengineering↗

ATG5- and ATG7-mediated autophagy regulates pollen tube guidance and male fertility in Arabidopsis thaliana

Autophagy functions as a crucial cellular scavenger by targeting cytoplasmic cargo to specific lysosome/vacuole for degradation. Autophagy-related (ATG) core proteins including ATG5 and ATG7 are evolutionarily conserved factors that are spatiotemporally orchestrated to regulate multiple processes of autophagy in yeast, mammalian and plant cells. However, autophagy is believed to be functionally dispensable in Arabidopsis thaliana since severe defects during plant growth, development and reproduction have not been observed in most of the ATG loss-of-function mutants, including atg5 and atg7, under standard cultivation conditions. In this study, we report that autophagy does in fact play roles in regulating pollen tube growth guidance and male fertility in Arabidopsis thaliana. A detailed re-assessment of atg5 and atg7 mutants revealed greatly reduced autophagy activity in germinated pollens and the seed formation within siliques is partially abolished. Next, we demonstrated that both the pollen germination ratio and pollen tube length of the mutants decreased at the beginning of germination by time-lapse tracking of pollen germination in vitro and in vivo. Additionally, we observed occurrences of pollen tube twisting and stacking during their growth towards the ovules. Finally, we found abnormal pollen grains containing only a single sperm cell or an undivided generative nucleus. Collectively, these results indicate that ATG5- and ATG7-mediated autophagy is functionally involved in regulating pollen germination, tube growth guidance and sperm cell development in Arabidopsis thaliana.

plant biology↗