1.Ion Filtering and Reactivity Investigation Based on Tandem Ion Mobility Spectrometry
Yi-Qian XU ; Qi-Mu YANG ; Man-Man PAN ; Dan-Dan JIANG ; Chuang CHEN ; Hai-Yang LI
Chinese Journal of Analytical Chemistry 2025;53(5):740-748
In analytical techniques such as ion mobility spectrometry(IMS)and mass spectrometry(MS),the ionization efficiency of target analytes is primarily constrained by the type of ionization source and factors such as the species and number density of the reactant ions.Systematic investigation into the reactivity differences of various reactant ions under varying conditions can not only significantly enhance the detection sensitivity of target compound product ions but also provide a theoretical foundation for establishing efficient detection methods based on ion-molecule reaction mechanisms.In this study,the pressure of a pressure-tunable photoionization tandem ion mobility spectrometry(PI-tandem-IMS)was reduced from ambient pressure(100 kPa)to low pressure(20 kPa)to systematically examine the reactivity differences between two negative reactant ions,CO3-and CO4-,and methyl salicylate(MeSA)under varying pressures.When the pressure decreased,the increased relative signal intensity of CO4-significantly influenced the detection sensitivity of the characteristic product ion[MeSA·O2]-.Based on differences in ion mobility(k0),the delay time for the opening of TPG2 was adjusted to selectively inject CO-3 and CO-4 in the drift region 2.Independent characterization of the reactivity of these reactant ions with MeSA in the reaction region confirmed that CO4-exhibited superior reactivity toward MeSA.The theoretical model revealed an Arrhenius plot for the ion-molecule reaction between CO4-and MeSA,showing a positive correlation between the reaction rate coefficient(k)and temperature,the activation energy Ea was 62.45 kJ/mol.Furthermore,controlling parameters such as pressure or temperature significantly influenced the progression of this ion-molecule reaction,demonstrating the technical advantages of PI-tandem-IMS in mechanistic studies and regulation of ion-molecule reactions.
2.Improvement of Performance of Ion Mobility Spectrometry Using A Low Discrimination Bradbury-Nielsen Gate Controlling Method
Qi-Mu YANG ; Yi-Qian XU ; Man-Man PAN ; Dan-Dan JIANG ; Chuang CHEN ; Hai-Yang LI
Chinese Journal of Analytical Chemistry 2025;53(6):875-884
The resolving power and sensitivity are critical for on-site detection of hazardous chemicals using stand-alone ion mobility spectrometry(IMS).However,improving the sensitivity and resolving power of IMS has long been a prominent research hot spot.In the commonly used IMS based on the Bradbury-Nielsen gate(BNG),the gating voltage difference(GVD)applied between the two sets of grid wires affects the electric field distribution in the ionization region and the drift region.This,in turn,influences the spatial distribution and temporal width of the injected ion swarm,and has an impact on the ion mobility discrimination,sensitivity,and resolving power of the instrument.This study showed that increasing the GVD could induce an ion converging effect,boosting the ion number density in front of the BNG by nearly 300%.To simultaneously utilize temporal compression and ion converging effects,a novel BNG controlling mode was proposed by adding a chopping state to the conventional controlling mode.This chopping state reduced the mobility discrimination effects between ions with mobility differences up to about 0.90 cm2/(V·s)to 1/22 of their original value.When analyzing hazardous chemical mixtures using the novel BNG controlling mode,compared with conventional mode,the signal intensity of low-mobility methyl salicylate ions(MS·O2)-increased by 18-fold while the resolving power maintained around 100,and the detection limit for MS was improved from 3.75 μg/L to 97 ng/L.This novel BNG controlling mode only added a potential wave to the low voltage wires,with no requirement of changing the structure of the drift tube,and was easy to apply to existing commercial instruments.
3.Longitudinal profile of plasma pregenomic RNA in patients with chronic hepatitis B infection on long-term nucleoside analogues and its interaction with clinical parameters
Lung-Yi MAK ; Mark ANDERSON ; Michael STEC ; Matthew Shing-Hin CHUNG ; Danny Ka-Ho WONG ; Rex Wan-Hin HUI ; Wai-Kay SETO ; Gavin CLOHERTY ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(2):460-473
Background:
s/Aims: Plasma pregenomic hepatitis B virus RNA (pgRNA) is a novel biomarker in chronic hepatitis B infection (CHB). We aimed to describe the longitudinal profile of pgRNA and factors influencing its levels in CHB patients on nucleoside analogue (NUC).
Methods:
Serial plasma samples from 1,354 CHB patients started on first-line NUC were evaluated. Time of NUC initiation was taken as baseline (year 0), followed by 1-year, 3-year and 5-year of NUC therapy. pgRNA was measured by Research Use Only RealTime HBV RNA v2.0 (0.2 mL) (Abbott Diagnostics) with lower limit of detection of 0.8 log U/mL (~20 copies/mL).
Results:
Among 1,354 subjects (median age at baseline 49.8 [interquartile range, IQR 40.2–57.3]) years, 65.2% male, 16.1% hepatitis B e antigen (HBeAg)-positive, 28.6% cirrhotic), baseline median HBV RNA was 3.68 (IQR 2.42–5.19) log U/mL. Upon NUC therapy, median pgRNA levels were 2.45 (IQR 1.82–3.62), 2.23 (IQR 1.67–3.05) and 2.14 (IQR 1.48–2.86) log U/mL at 1, 3 and 5 years, respectively, with the corresponding log U/mL reductions of 0.82, 1.20 and 1.54. Undetectable/ unquantifiable pgRNA was achieved in 13.5%, 15.9% and 20.1% of patients at 1, 3 and 5 years, respectively. Older age, male sex, HBeAg-negativity and high PAGE-B score were associated with lower pgRNA.
Conclusions
Plasma pgRNA declines are modest under NUC therapy, with only 16.3% achieving RNA undetectability after 5 years of first-line NUC indicating cccDNA silencing has not been achieved in the majority of patients. Clinical characteristics should be taken into consideration when interpreting the plasma pgRNA level.
4.Prospect of emerging treatments for hepatitis B virus functional cure
Rex Wan-Hin HUI ; Lung-Yi MAK ; James FUNG ; Wai-Kay SETO ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(Suppl):S165-181
Functional cure, defined as sustained hepatitis B surface antigen (HBsAg) seroclearance with unquantifiable hepatitis B virus (HBV) DNA at 24 weeks off treatment, is a favorable treatment endpoint in chronic hepatitis B (CHB). Nonetheless, functional cure is rarely attained with the current treatment modalities of nucleos(t)ide analogues (NUCs) and pegylated interferon alpha. Multiple novel virus-targeting agents and immunomodulators are under development for HBV with functional cure as the treatment goal. Among virus-targeting agents, antisense oligonucleotides and small-interfering RNAs are the most advanced in the developmental pipeline, and can induce potent and sustainable HBsAg suppression. The other virus-targeting agents have varying effects on HBsAg and HBV DNA, depending on the drug mechanism. In contrast, immunomodulators have modest effects on HBsAg and have limited roles in monotherapy. Multiple combination regimens incorporating RNA interference agents with immunomodulators have been studied through many ongoing clinical trials. These combination strategies demonstrate synergistic effects in inducing functional cure, and will likely be the future direction of development. Despite the promising results, research is warranted to optimize treatment protocols and to establish criteria for NUC withdrawal after novel therapies. Functional cure is now an attainable target in CHB, and the emerging novel therapeutics will revolutionize CHB management.
5.Mechanisms of hepatocellular carcinoma and cirrhosis development in concurrent steatotic liver disease and chronic hepatitis B
Saisai ZHANG ; Lung-Yi MAK ; Man-Fung YUEN ; Wai-Kay SETO
Clinical and Molecular Hepatology 2025;31(Suppl):S182-S195
Chronic hepatitis B (CHB) poses a major global public health challenge and is a leading cause of cirrhosis and liver cancer. Hepatic steatosis is common in individuals with CHB compared to the non-CHB population and is particularly prevalent in hepatitis B virus (HBV)-endemic regions, affecting about one-third of CHB patients. The interaction between hepatic steatosis and CHB-related disease progression is complex and still under debate. Evidence demonstrates that co-existing steatosis may worsen liver fibrosis while paradoxically increasing the likelihood of achieving better HBV control. In particular, despite the association of steatotic liver disease (SLD) with lower HBV viral loads and higher rates of HBsAg seroclearance, the coexistence of CHB and SLD can potentially accelerate liver disease progression. Factors such as fat deposition, lipotoxicity, oxidative stress, and chronic inflammation in SLD may foster a pro-fibrotic and pro-carcinogenic environment, accelerating the disease progression. Additionally, loss of global DNA methylation, changes in the immune microenvironment, and genetic susceptibility further contribute to the development of CHB-related cirrhosis and hepatocellular carcinoma (HCC). This review examines the mechanisms driving liver disease progression and the heightened risk of cirrhosis and HCC in patients with concurrent CHB and steatotic liver disease, underscoring the importance of prioritizing antiviral therapy for CHB in addition to addressing SLD.
6.Rubioncolin C targets cathepsin D to induce autophagosome accumulation and suppress gastric cancer.
Liang ZHANG ; Jun-Jie CHEN ; Man-Xiang GU ; Yi-Fan ZHONG ; Yuan SI ; Ying LIU
China Journal of Chinese Materia Medica 2025;50(5):1267-1275
This study aimed to explore the molecular mechanism of rubioncolin C(RuC) in inhibiting gastric cancer(GC). AGS and MGC803 cell lines were selected as cellular models. After treating the cells with RuC at different concentrations, the effects of RuC on the proliferation ability of GC cells were assessed using the CCK-8 method, real-time cellular analysis(RTCA), and colony formation assays. Transmission electron microscopy was used to observe subcellular structural changes. Immunofluorescence was applied to detect LC3 fluorescent foci. Acridine orange staining was used to evaluate the state of intracellular lysosomes. Western blot was employed to detect the expression of autophagy-related proteins LC3Ⅱ, P62, and lysosomal cathepsin D(CTSD). The SuperPred online tool was used to predict the target proteins that bound to RuC, and molecular docking analysis was conducted to identify the interaction sites between RuC and CTSD. The drug affinity responsive target stability(DARTS) assay was performed to detect the direct binding interaction between RuC and CTSD. The results showed that RuC significantly inhibited the proliferation and colony formation of GC cells at low concentrations, with 24-hour half-maximal inhibitory concentrations(IC_(50)) of 3.422 and 2.697 μmol·L~(-1) for AGS and MGC803 cells, respectively. After 24 hours of treatment with RuC at concentrations of 1, 2, and 3 μmol·L~(-1), the colony formation rates for AGS cells were 61.0%±1.5%, 28.0%±0.5%, and 18.2%±0.5%, respectively, while the rates for MGC803 cells were 56.0%±0.5%, 23.3%±1.0%, and 11.8%±1.0%, all of which were significantly reduced. Transmission electron microscopy revealed that RuC promoted an increase in autophagosome formation in GC cells. Immunofluorescence detection showed that LC3 fluorescent foci of GC cells increased with the increase in RuC dose. RuC up-regulated the expression of autophagy-related proteins LC3Ⅱ and P62 in GC cells. Acridine orange staining indicated that RuC altered the acidic environment of lysosomes. SuperPred online prediction identified CTSD as a potential target protein of RuC. Western blot analysis revealed that RuC induced the up-regulation of the inactive precursor of CTSD in GC cells. CTSD activity assays indicated that RuC reduced the activity of CTSD. Molecular docking simulations found that RuC bound to the substrate-binding region of CTSD, forming hydrogen bonds with the Tyr205 and Asp231 residues. Microscale thermophoresis and DARTS assays further confirmed that RuC directly bound to CTSD. In summary, RuC inhibits lysosomal activity by targeting and down-regulating the expression of CTSD, thereby inducing autophagosome accumulation in GC cells.
Humans
;
Stomach Neoplasms/enzymology*
;
Cathepsin D/chemistry*
;
Cell Line, Tumor
;
Molecular Docking Simulation
;
Cell Proliferation/drug effects*
;
Autophagosomes/metabolism*
;
Autophagy/drug effects*
7.Programmed death-ligand 1 regulates ameloblastoma growth and recurrence.
Linzhou ZHANG ; Hao LIN ; Jiajie LIANG ; Xuanhao LIU ; Chenxi ZHANG ; Qiwen MAN ; Ruifang LI ; Yi ZHAO ; Bing LIU
International Journal of Oral Science 2025;17(1):29-29
Tumor cell-intrinsic programmed death-ligand 1 (PD-L1) signals mediate tumor initiation, progression and metastasis, but their effects in ameloblastoma (AM) have not been reported. In this comprehensive study, we observed marked upregulation of PD-L1 in AM tissues and revealed the robust correlation between elevated PD-L1 expression and increased tumor growth and recurrence rates. Notably, we found that PD-L1 overexpression markedly increased self-renewal capacity and promoted tumorigenic processes and invasion in hTERT+-AM cells, whereas genetic ablation of PD-L1 exerted opposing inhibitory effects. By performing high-resolution single-cell profiling and thorough immunohistochemical analyses in AM patients, we delineated the intricate cellular landscape and elucidated the mechanisms underlying the aggressive phenotype and unfavorable prognosis of these tumors. Our findings revealed that hTERT+-AM cells with upregulated PD-L1 expression exhibit increased proliferative potential and stem-like attributes and undergo partial epithelial‒mesenchymal transition. This phenotypic shift is induced by the activation of the PI3K-AKT-mTOR signaling axis; thus, this study revealed a crucial regulatory mechanism that fuels tumor growth and recurrence. Importantly, targeted inhibition of the PD-L1-PI3K-AKT-mTOR signaling axis significantly suppressed the growth of AM patient-derived tumor organoids, highlighting the potential of PD-L1 blockade as a promising therapeutic approach for AM.
Ameloblastoma/metabolism*
;
Humans
;
B7-H1 Antigen/metabolism*
;
Neoplasm Recurrence, Local/pathology*
;
Signal Transduction
;
Cell Proliferation
;
Up-Regulation
;
TOR Serine-Threonine Kinases/metabolism*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Telomerase/metabolism*
;
Jaw Neoplasms/metabolism*
;
Epithelial-Mesenchymal Transition
;
Animals
;
Cell Line, Tumor
;
Female
;
Male
8.Predictive Modeling of Symptomatic Intracranial Hemorrhage Following Endovascular Thrombectomy: Insights From the Nationwide TREAT-AIS Registry
Jia-Hung CHEN ; I-Chang SU ; Yueh-Hsun LU ; Yi-Chen HSIEH ; Chih-Hao CHEN ; Chun-Jen LIN ; Yu-Wei CHEN ; Kuan-Hung LIN ; Pi-Shan SUNG ; Chih-Wei TANG ; Hai-Jui CHU ; Chuan-Hsiu FU ; Chao-Liang CHOU ; Cheng-Yu WEI ; Shang-Yih YAN ; Po-Lin CHEN ; Hsu-Ling YEH ; Sheng-Feng SUNG ; Hon-Man LIU ; Ching-Huang LIN ; Meng LEE ; Sung-Chun TANG ; I-Hui LEE ; Lung CHAN ; Li-Ming LIEN ; Hung-Yi CHIOU ; Jiunn-Tay LEE ; Jiann-Shing JENG ;
Journal of Stroke 2025;27(1):85-94
Background:
and Purpose Symptomatic intracranial hemorrhage (sICH) following endovascular thrombectomy (EVT) is a severe complication associated with adverse functional outcomes and increased mortality rates. Currently, a reliable predictive model for sICH risk after EVT is lacking.
Methods:
This study used data from patients aged ≥20 years who underwent EVT for anterior circulation stroke from the nationwide Taiwan Registry of Endovascular Thrombectomy for Acute Ischemic Stroke (TREAT-AIS). A predictive model including factors associated with an increased risk of sICH after EVT was developed to differentiate between patients with and without sICH. This model was compared existing predictive models using nationwide registry data to evaluate its relative performance.
Results:
Of the 2,507 identified patients, 158 developed sICH after EVT. Factors such as diastolic blood pressure, Alberta Stroke Program Early CT Score, platelet count, glucose level, collateral score, and successful reperfusion were associated with the risk of sICH after EVT. The TREAT-AIS score demonstrated acceptable predictive accuracy (area under the curve [AUC]=0.694), with higher scores being associated with an increased risk of sICH (odds ratio=2.01 per score increase, 95% confidence interval=1.64–2.45, P<0.001). The discriminatory capacity of the score was similar in patients with symptom onset beyond 6 hours (AUC=0.705). Compared to existing models, the TREAT-AIS score consistently exhibited superior predictive accuracy, although this difference was marginal.
Conclusions
The TREAT-AIS score outperformed existing models, and demonstrated an acceptable discriminatory capacity for distinguishing patients according to sICH risk levels. However, the differences between models were only marginal. Further research incorporating periprocedural and postprocedural factors is required to improve the predictive accuracy.
9.Longitudinal profile of plasma pregenomic RNA in patients with chronic hepatitis B infection on long-term nucleoside analogues and its interaction with clinical parameters
Lung-Yi MAK ; Mark ANDERSON ; Michael STEC ; Matthew Shing-Hin CHUNG ; Danny Ka-Ho WONG ; Rex Wan-Hin HUI ; Wai-Kay SETO ; Gavin CLOHERTY ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(2):460-473
Background:
s/Aims: Plasma pregenomic hepatitis B virus RNA (pgRNA) is a novel biomarker in chronic hepatitis B infection (CHB). We aimed to describe the longitudinal profile of pgRNA and factors influencing its levels in CHB patients on nucleoside analogue (NUC).
Methods:
Serial plasma samples from 1,354 CHB patients started on first-line NUC were evaluated. Time of NUC initiation was taken as baseline (year 0), followed by 1-year, 3-year and 5-year of NUC therapy. pgRNA was measured by Research Use Only RealTime HBV RNA v2.0 (0.2 mL) (Abbott Diagnostics) with lower limit of detection of 0.8 log U/mL (~20 copies/mL).
Results:
Among 1,354 subjects (median age at baseline 49.8 [interquartile range, IQR 40.2–57.3]) years, 65.2% male, 16.1% hepatitis B e antigen (HBeAg)-positive, 28.6% cirrhotic), baseline median HBV RNA was 3.68 (IQR 2.42–5.19) log U/mL. Upon NUC therapy, median pgRNA levels were 2.45 (IQR 1.82–3.62), 2.23 (IQR 1.67–3.05) and 2.14 (IQR 1.48–2.86) log U/mL at 1, 3 and 5 years, respectively, with the corresponding log U/mL reductions of 0.82, 1.20 and 1.54. Undetectable/ unquantifiable pgRNA was achieved in 13.5%, 15.9% and 20.1% of patients at 1, 3 and 5 years, respectively. Older age, male sex, HBeAg-negativity and high PAGE-B score were associated with lower pgRNA.
Conclusions
Plasma pgRNA declines are modest under NUC therapy, with only 16.3% achieving RNA undetectability after 5 years of first-line NUC indicating cccDNA silencing has not been achieved in the majority of patients. Clinical characteristics should be taken into consideration when interpreting the plasma pgRNA level.
10.Prospect of emerging treatments for hepatitis B virus functional cure
Rex Wan-Hin HUI ; Lung-Yi MAK ; James FUNG ; Wai-Kay SETO ; Man-Fung YUEN
Clinical and Molecular Hepatology 2025;31(Suppl):S165-181
Functional cure, defined as sustained hepatitis B surface antigen (HBsAg) seroclearance with unquantifiable hepatitis B virus (HBV) DNA at 24 weeks off treatment, is a favorable treatment endpoint in chronic hepatitis B (CHB). Nonetheless, functional cure is rarely attained with the current treatment modalities of nucleos(t)ide analogues (NUCs) and pegylated interferon alpha. Multiple novel virus-targeting agents and immunomodulators are under development for HBV with functional cure as the treatment goal. Among virus-targeting agents, antisense oligonucleotides and small-interfering RNAs are the most advanced in the developmental pipeline, and can induce potent and sustainable HBsAg suppression. The other virus-targeting agents have varying effects on HBsAg and HBV DNA, depending on the drug mechanism. In contrast, immunomodulators have modest effects on HBsAg and have limited roles in monotherapy. Multiple combination regimens incorporating RNA interference agents with immunomodulators have been studied through many ongoing clinical trials. These combination strategies demonstrate synergistic effects in inducing functional cure, and will likely be the future direction of development. Despite the promising results, research is warranted to optimize treatment protocols and to establish criteria for NUC withdrawal after novel therapies. Functional cure is now an attainable target in CHB, and the emerging novel therapeutics will revolutionize CHB management.

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