PubMed Health⌕ Search

Biomedical subjects

Min Liu

Publications and source records attributed to Min Liu.

At least 19 recordsLinked to original sources
PubMed2026

Comparison of Keverprazan-based versus esomeprazole-based dual therapy for initial treatment of Helicobacter pylori infection: a prospective, multicenter, randomized controlled trial.

BACKGROUND: Keverprazan offers a new perspective for Helicobacter pylori eradication. This study compared 14-day keverprazan-amoxicillin therapy with esomeprazole-amoxicillin therapy to explore a superior treatment strategy. METHODS: This was a prospective, open-label, multicenter, randomized controlled trial in adult patients with treatment-naive H. pylori infection. Participants were randomly assigned to receive either 14-day of KA therapy (Keverprazan 20&#x2009;mg b.i.d plus amoxicillin 1&#x2009;g t.i.d) or 14-day of EA therapy (Esomeprazole 40&#x2009;mg b.i.d plus amoxicillin 1&#x2009;g t.i.d). The primary outcome was the H. pylori eradication rate. Secondary outcomes were the incidence of adverse events and patient adherence. RESULTS: A total of 264 patients were enrolled in the study. In the intention-to-treat (ITT) analysis, the eradication rates for the 14-day KA group and the 14-day EA group were 87.9% and 80.3%, respectively (p&#x2009;=&#x2009;0.092); in the modified intention-to-treat (mITT) analysis, the eradication rates were 92.1% and 86.2%, respectively (p&#x2009;=&#x2009;0.135); and in the per-protocol (PP) analysis, the eradication rates were 93.5% and 88.3%, respectively (p&#x2009;=&#x2009;0.155). Non-inferiority was confirmed between the two groups (all p&#x2009;<&#x2009;0.001). Adverse events and patient adherence were similar between the two groups. CONCLUSION: For treatment-naive H. pylori infection, the 14-day KA therapy is non-inferior to EA therapy. Given its good tolerability, pharmacogenomic independence, and potent acid suppression, KA is a rational first-line alternative to EA in the Chinese population.

Humans↗
PubMed2026

Sex- and development-specific transcriptomic profiling of venom and silk genes in the wolf spider Pardosa astrigera provides insights into ecological adaptation and predatory strategies.

Spider venom and silk glands are two major secretory systems that contribute to prey capture, defense, and reproduction, but their sex- and development-specific molecular regulation in wandering wolf spiders remains poorly understood. Here, the transcriptome of Pardosa astrigera, an important agricultural natural enemy in China, revealed significant sex- and development-associated molecular differentiation among adult females, adult males, and spiderlings. A total of 100,025 unigenes were obtained, of which 23,852 were functionally annotated, providing a comprehensive transcriptomic resource for this species. Differential expression patterns showed marked variation among groups, with 531, 1792, and 832 DEGs detected in PAF vs PAS, PAM vs PAS, and PAF vs PAM, respectively. These genes were mainly associated with metabolic, oxidation-reduction, cuticle development, MAPK signaling, and lysosome pathways. Fifteen co-expression modules revealed distinct expression patterns. The turquoise, pink, yellow, and red modules were development-related, whereas the blue module was male-biased. Venom- and spidroin-related genes were distributed across multiple modules, suggesting coordinated regulation. Overall, 42 venom peptides, 21 venom proteins, and 11 spidroins were identified. Representative genes showed strongly biased expression, including spiderling-biased U3_Pp1a and U5_Pp1e, female-biased U4_Pp1a, and male-biased SMase D_108750 and PaTuSp_108466. These findings reveal sex- and development-biased expression patterns of venom- and silk-related candidate genes in P. astrigera and may provide molecular insights into ecological adaptation and predatory strategies in wandering wolf spiders.

Animals↗
PubMed2026

Comparison of short-term clinical outcomes and patient satisfaction between intraoral scanning and conventional impressions for complete-arch implant prostheses: a pilot RCT.

OBJECTIVE: To compare framework passive fit, subjective evaluations, and short-term clinical outcomes between conventional impressions (CI) and intraoral scanning (IOS) for complete-arch implant-supported fixed dental prostheses (CIFDPs). METHODS: In this randomized controlled trial, 22 patients were allocated to the CI or IOS groups. All participants received a definitive one-piece CIFDP. The primary outcome was framework passive fit, assessed using the Vision and Tactile Score (V&T score), which included framework lift-off, the single-screw test, the full-screw test, smoothness of screw insertion, and radiographic gap assessment. Secondary outcomes included operator evaluation, patient satisfaction using a visual analog scale (VAS), early implant survival, marginal bone loss (MBL), modified Plaque Index (mPII), and complications at the 6-month follow-up. RESULTS: Twenty-two patients were enrolled (CI: n = 11; IOS: n = 11), and one patient in the CI group was lost to follow-up. No statistically significant difference in the V&T score was observed between the CI and IOS groups (4.66 &#xb1; 0.17 vs. 4.65 &#xb1; 0.28; P = 0.93). The operator reported greater nervousness during the CI procedure than during IOS (21.82 &#xb1; 15.69 vs. 8.64 &#xb1; 7.47; P < 0.05). Patients in the CI group reported significantly greater discomfort, including nausea and anxiety, than those in the IOS group (P < 0.05). At the 6-month follow-up, the early implant survival rate was 100% in both groups. No significant differences were found between the groups in MBL (0.09 &#xb1; 0.09 vs. 0.06 &#xb1; 0.10 mm; P = 0.43) or mPII (0.10 &#xb1; 0.12 vs. 0.10 &#xb1; 0.28; P = 0.99). CONCLUSION: IOS and CI achieved comparable short-term clinical outcomes in patients who met the predefined inclusion criteria, including controlled implant number, spacing, and angulation. IOS provided a more favorable experience for both operators and patients. CLINICAL SIGNIFICANCE: In complete-arch implant restorations, intraoral scanning may provide clinical outcomes comparable to those of conventional impressions while improving patient comfort.

Humans↗
PubMed2026

Mycobacterium tuberculosis MEM39 (Rv1977) hijacks host aldolase A (ALDOA) to subvert immunometabolism to facilitate bacterial intracellular survival.

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the leading cause of infectious disease-related death. As a major intracellular pathogen, Mtb can escape clearance by the immune system, but the underlying molecular mechanisms remain incompletely elucidated. Specific genomic regions of deletion (RD)-encoded proteins in virulent Mtb H37Rv have been implicated in modulating pathogenicity and immunity. Here, we report a novel RD15-encoding protein, Rv1977 (a mycobacterial cell wall protein with a size of 39&#x2009;kDa, named MEM39), which facilitates Mtb survival in macrophages. The survival of the Mtb H37Rv MEM39-deficient strain is reduced in both macrophage and murine infection models. Furthermore, the mycobacterial MEM39 protein binds fructose-diphosphate aldolase A (ALDOA), a key enzyme of glycolysis, thereby impairing ALDOA enzyme activity, disrupting macrophage metabolite flux, and reducing lactate production. The MEM39-ALDOA interaction also suppresses lysosomal acidification; reduces NLRP3 inflammasome activation and the production of proinflammatory cytokines (TNF-&#x3b1;, IL-6 and IL-1&#x3b2;); and thereby promotes bacterial survival within macrophages. Disruption of the interaction between MEM39-ALDOA and a cell-penetrating synthetic peptide (VLARYASICQ) significantly suppressed Mtb survival by restoring lactate production, lysosome acidification and proinflammatory cytokine production in both macrophage and mouse infection models. These findings revealed that mycobacterial MEM39 negatively regulates host immune defense through reprogramming ALDOA-mediated glycolysis in macrophages, thereby forming a "mycobacterial MEM39 virulence factor-glycolysis metabolism-immunity" regulatory axis. Targeting MEM39 or the MEM39-ALDOA interaction interface holds promise as a new therapeutic strategy against tuberculosis.

Mycobacterium tuberculosis↗
PubMed2026

A CRISPR-Cas9 screen identifies LAPTM4A (lysosomal protein transmembrane 4 alpha) as a key host barrier against PRRSV infection.

Porcine reproductive and respiratory syndrome virus (PRRSV) manipulates host intracellular processes, particularly macroautophagy/autophagy and lysosomal function, to facilitate its replication and spread. However, the precise host factors and molecular mechanisms by which PRRSV remodels the autophagy-lysosome axis remain poorly defined. Here, we performed a CRISPR-Cas9 knockout screen targeting 1,332 genes involved in protein degradation, metabolism, and vesicular trafficking, and identified LAPTM4A (lysosomal protein transmembrane 4 alpha) as a critical antiviral factor involved in the lysosomal pathway. A yeast two-hybrid screen identified LAPTM4A as an interactor of PRRSV GP5 (glycoprotein 5). Mechanistically, GP5 recruits the E3 ubiquitin ligase NEDD4 and the autophagy receptor SQSTM1/p62 to promote K63-linked polyubiquitination of LAPTM4A, leading to its autophagic degradation. This selective degradation activates the AMPK-ULK1-MAP1LC3/LC3 signaling cascade, initiating autophagy while facilitating MTOR-lysosome colocalization, thereby suppressing TFEB nuclear translocation and transcription of lysosome-related genes. The resulting incomplete autophagic flux enhances viral replication. Additionally, in terms of host defense, LAPTM4A maintains lysosomal homeostasis by restraining excessive autophagy through AMPK-ULK1-LC3 signaling and promoting TFEB-dependent lysosomal gene expression by impairing the binding of RPTOR/raptor to MTOR, thus providing broad antiviral protection against multiple RNA viruses. Collectively, our findings identify LAPTM4A as a central regulator of lysosome-autophagy homeostasis and reveal a viral strategy that dismantles this defense axis to facilitate infection.Abbreviations: ATG5: autophagy related 5; AMPK: adenosine 5'-monophosphate (AMP)-activated protein kinase; Baf A1: bafilomycin A1; CHX: cycloheximide; Co-IP: co-immunoprecipitation; DMVT library: protein degradation, metabolism, and vesicular trafficking library; LAPTM4A: lysosomal protein transmembrane 4 alpha; MAGeCK: model-based analysis of genome-wide CRISPR-Cas9 knockout; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; NC: negative control; PAMs: porcine alveolar macrophages; PRKAA/AMPK&#x3b1;: protein kinase AMP-activated catalytic subunit alpha; PRRSV: porcine reproductive and respiratory syndrome virus; qRT-PCR: quantitative real-time PCR; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TCID50: 50% tissue culture infective dose; TFEB: transcription factor EB; Ub: ubiquitin; ULK1: unc-51 like autophagy activating kinase 1; WT: wild type.

Animals↗
PubMed2026

A single-nucleus and spatial transcriptomic atlas of poplar leaves reveals the regulation of leaf polarity and cuticle deposition.

Leaf adaxial-abaxial polarity is fundamental for plant morphogenesis and environmental adaptation through asymmetric cell differentiation. Emerging evidence reveals dorsoventral metabolic gradients act downstream of transcriptional networks to fine-tune cellular specialization. While conserved transcription factors (e.g., HD-ZIP III and KANADI) establish initial polarity, the molecular networks driving position-specific cellular differentiation and their integration with metabolic adaptation remain unclear. Leveraging single-nucleus and spatial transcriptomics, we resolve major cell classes (mesophyll, epidermal, and vascular-associated) and their adaxial-abaxial subtypes, revealing dorsoventral polarity in transcriptional profiles and metabolic pathways. Adaxial cells are enriched in phenylpropanoid/flavonoid biosynthesis, while abaxial cells show preferential activation of stress and hormone signaling. Notably, we identify MYC2 as a key regulator of adaxial cuticle biosynthesis, binding to promoters of lipid biosynthetic and transport genes (e.g., CER10 and LTPG1) and promoting cuticle thickening. Our study uncovers how positional identity shapes transcriptional and metabolic polarity in leaves, with MYC2 emerging as a central regulator coordinating organ-specific adaptations. These findings provide insights into the spatial regulation of plant development and stress resilience, offering potential strategies for engineering stress-tolerant woody crops.

Plant Leaves↗
PubMed2025

Engineering TME-activated CD47-specific CAR macrophage via Arg1 promoter for safe and effective solid tumor immunotherapy.

BACKGROUND: Chimeric antigen receptor macrophage (CAR-M&#x3c6;) therapy has promising therapeutic potential in solid tumors, yet challenges remain in target compatibility and systemic toxicity. METHODS: In this study, we screened the CD47-scFv sequence of CAR-M&#x3c6; as the extracellular structure. We then constructed a classical CD47 CAR-M&#x3c6; incorporated the costimulatory domain of the &#x3b1;1&#x3b2;1 integrin-mediated Fc-gamma receptor I (Fc&#x3b3;RI) signaling component. Subsequently, we developed a tumor microenvironment (TME)-responsive CAR macrophage platform by the arginase 1 (Arg1) promoter to target CD47, a highly expressed but clinically challenging immune checkpoint in solid tumors. RESULTS: We found that anti-CD47-scFv-mediated macrophages can effectively kill tumor cells both in vivo and in vitro. Furthermore, by integrating an &#x3b1;1&#x3b2;1 integrin-mediated Fc&#x3b3;RI signaling domain, CD47 CAR-M&#x3c6; exhibited superior antitumor activity in hCD47+4T1&#x2009;and SGC-7901 cells in vitro, which demonstrated that the CD47 CAR-M&#x3c6; was effective against solid tumors. Subsequently, Arg1-mediated activated pArg1 CD47 CAR-M&#x3c6; exhibited strong cytotoxicity against target cancer cells. We further demonstrated TME-controllable CAR gene expression in situ and induced a significant regression of established tumors in vivo. Besides, TME-dependent activation of CD47 CAR M&#x3c6; reduced the cytotoxic killing effect on erythrocytes. CONCLUSIONS: Our findings confirmed that the TME-specific activation mechanism of pArg1 CD47 CAR-M&#x3c6; based on intrinsic Arg1 promoter reprogramming endowed CAR-M&#x3c6; to effectively mitigate erythrocyte toxicity while enabling safe multidose administration regimens. This Trojan horse-like CAR-M&#x3c6; system achieves tumor-specific activation while minimizing systemic toxicity, offering a novel strategy to expand CAR-M&#x3c6; applications for solid tumors.

Animals↗
PubMed2025

Proteomic insights into platelet dysregulation and pathogenic mechanisms of chronic thromboembolic pulmonary hypertension.

BACKGROUND: Undissolved thrombus blocks the pulmonary arteries in chronic thromboembolic pulmonary hypertension (CTEPH), a potentially fatal illness that raises pulmonary resistance, causes right heart failure, and even results in death. Although platelets are linked to vascular dysfunction and thrombus formation, it is yet unknown what precise proteome alterations and mechanistic roles they play in CTEPH. METHODS: We extracted platelet-rich plasma from peripheral blood and separated the plasma to obtain enriched platelet pellet (EPP). Quantitative proteomics was used to examine EPP from CTEPH patients and healthy controls using mass spectrometry. The relationship between protein levels and clinical markers of right heart function was examined. Platelet activity, morphology, and interactions with other blood components were evaluated using transmission electron microscopy, immunofluorescence, and flow cytometry. RESULTS: The proteomic investigation found that 179 proteins were differentially expressed in CTEPH patients. The analysis revealed that these proteins were involved in crucial processes such as complement and coagulation cascades, phagosome, and neutrophil extracellular trap (NET) formation. Elevated proteins, specifically NOX2, PAD4, ITGB2, and HMGB1, have been associated to platelet-neutrophil aggregates and NET formation. In addition, enhanced P-selectin expression in platelets and plasma confirmed greater platelet activation in CTEPH patients. Notably, PAD4 and NOX2 levels showed a substantial correlation with hemodynamic parameters and right heart dysfunction. MPO-DNA, a NET marker associated with P-selectin and ITGB2 expression, was discovered in higher concentrations in CTEPH patients' plasmas. CONCLUSION: Platelet aggregation and activation in CTEPH encourage the formation of NETs, which advances the disease and prolongs thrombus. Right heart insufficiency and hemodynamic markers had a strong correlation with PAD4 and NOX2 levels, indicating that these biomarkers may be employed to assess the severity and prognosis of CTEPH disease and offer a fresh approach to targeted treatment. The results highlight the need for additional study to elucidate platelet-mediated pathways and create therapies for CTEPH that target platelets.

Humans↗
PubMed2025

Tandem gene duplication facilitates intertidal adaptation in atypical mangrove plants.

Mangrove plants, originating from inland ancestors, have independently adapted to extreme intertidal zones characterized by salt and hypoxia stress. While typical mangroves exhibit specialized phenotypes, like viviparous seeds and salt secretion, atypical clades that have thrived without such traits are particularly suitable for exploring the molecular and physiological basis underlying plant adaptation to intertidal zones. We assembled a chromosome-level genome of an atypical mangrove, Scyphiphora hydrophylacea, the only mangrove species in Gentianales. Similar to other mangroves, S. hydrophylacea colonized intertidal zones during climatic optimum periods of sea-level rise. Despite lacking recent whole-genome duplications (WGDs), its genome acquired extensive tandem gene duplications (TDs), leading to the rapid expansion of key salt- and hypoxia-related genes. Transcriptome data further corroborated that TD-driven gene expansions contribute to stress tolerance. Specifically, the expansion of genes involved in cation transmembrane transport, osmotic regulation, and oxidative stress response may enhance salinity tolerance, and the expansion of signal transduction and energy metabolism genes in hypoxia-response pathways may confer waterlogging tolerance. Therefore, in the absence of large-scale gene duplication, the rapid expansion of core genes involved in salt and hypoxia tolerance through tandem duplication may represent a key force driving the adaptation of atypical mangroves. These findings also provide valuable insights for crop improvement strategies aimed at enhancing environmental resilience while maintaining phenotypic stability.

Gene Duplication↗
PubMed2006

Temporal trends of esophageal cancer during 1995-2004 in Nanao Island, an extremely high-risk area in China.

The purpose of our study was to investigate the temporal malignant tumor incidence rates among the 70,000 residents at the relatively isolated Nanao Island in South China Sea. The data on all malignant tumor cases from Nanao Cancer Registry during 1995-2004 were coded, computerized, and analyzed using the software SPSS10.0. The tumor incident cases, crude incident rate, age-standardized incidence rate, their sex distribution and temporal trend were assessed. A total of 1450 new cancer cases (990 males and 460 females) were identified. The annual average age-standardized incidence rate (ASR) of malignant tumors was 208.18/100,000. The age-standardized incidence rate of the ten leading cancers in both sexes combined per 100,000 population were 74.47 for esophageal cancer (EC), 34.81 for cardiac cancer (CC), 25.66 for liver cancer, 26.01 for lung cancer, 18.52 for stomach cancer, 4.45 for nasopharyngeal cancer, 3.91 for breast cancer, 2.53 for colon/rectum cancer, 2.45 for bladder cancer and 1.92 for pancreatic cancer. These ten types of cancers make up to 93% of all cancer cases, with EC and CC being the most prevalent and making up 52% of the total cases. The incidence rates of esophagus, liver, lung, breast, nasopharyngeal, and colon/rectum cancers showed increasing trends during the period from 1995 to 2004 in Nanao Island. Astounding the EC ASR were 72-150/100,000 among male and 26-64/100,000 among female in Nanao Island during 1995-2004. The EC incidence rate in Nanao population is among the highest across the world, which suggests that there are potential genetic and/or environmental factors affecting this particular population.

Age Distribution↗
PubMed2006

Engineering of N-glycosylation of hepatitis C virus envelope protein E2 enhances T cell responses for DNA immunization.

N-linked oligosaccharides are known to be important in modulating immunogenicity of some viral proteins. However, the roles of N-glycans of hepatitis C virus (HCV) E2 envelope glycoprotein in specific cellular immune responses remain elusive. Previous studies showed that the epitopes aa481-500 and aa551-570 of E2 might be important for immunoreactivity and that the binding site of E2 for hCD81 is located at aa480-493 and aa544-551 within the E2 protein. Here, we made plasmids containing genes encoding either wild type or mutant E2 proteins in which N-glycosylation sites (N560NT and N576ST) close to these important regions were mutated separately or in combination. The immunogenicities of wild type E2 and three mutated E2 proteins were analyzed in BALB/c mice using DNA vaccination. The E2-M2 mutant (at N576ST) significantly enhanced (compared to control) E2-specific CTL activity (P<0.05), expression of IFN-gamma (P<0.05) and suppression of tumor growth (P<0.05). Also, high IgG2a/IgG1 ratios were elicited in a Th1-type response. These results indicate that engineering of the N-glycosylation site N576ST of HCV E2 protein enhances specific cellular immune responses, providing insights into the development of E2-based DNA vaccines with enhanced immunogenicity.

Animals↗
PubMed2006

Emergent criticality from coevolution in random Boolean networks.

The coevolution of network topology and dynamics is studied in an evolutionary Boolean network model that is a simple model of a gene regulatory network. We find that a critical state emerges spontaneously resulting from the interplay between topology and dynamics during the evolution. The final evolved state is shown to be independent of initial conditions. The network appears to be driven to a random Boolean network with uniform in-degree of 2 in the large-network limit. However, for biologically realized network sizes, significant finite-size effects are observed including a broad in-degree distribution and an average in-degree connections between 2 and 3. These results may be important for explaining the properties of gene regulatory networks.

Cell Physiological Phenomena↗
PubMed2006

Mechanism of the induction of brain c-Fos-positive neurons by lipid absorption.

Many gastrointestinal meal-related signals are transmitted to the central nervous system via the vagus nerve and thereby control changes in meal size. The c-Fos-positive neuron has been used as a marker of neuronal activation after lipid meals to examine the contribution of a selective macronutrient on brain neurocircuit activity. In rats fed Intralipid, the c-Fos-positive neurons were highly stimulated in the nucleus of the solitary tract (NTS) and in the hypothalamus, including the paraventricular nucleus (PVN), arcuate nucleus of the hypothalamus (ARC), and ventromedial hypothalamus at 4 h lipid feeding. However, c-Fos-like immunoreactivity was markedly attenuated in these brain regions when chylomicron formation/secretion was blocked by Pluronic L-81. After lymph was diverted from the lymph cannulated animals, the rats had a lower number of c-Fos-positive cells in the NTS and ARC. In contrast, the rats had higher c-Fos-positive neurons in PVN. The present study also revealed that c-Fos-positive neurons induced by feeding of Intalipid were abolished by CCK type 1 receptor antagonist, Lorglumide. We conclude that the formation and/or secretion of chylomicron are critical steps for initiating neuronal activation in the brain.

Animals↗
PubMed2006

N-acetylcysteine attenuates TNF-alpha-induced human vascular endothelial cell apoptosis and restores eNOS expression.

The circulatory inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is increased in pathological conditions, such as diabetes, which initiate or exacerbate vascular endothelial injury. Both nitric oxide (NO) and reactive oxygen species may play a dual role (i.e., inhibiting or promoting) in TNF-alpha-induced endothelial cell apoptosis. We investigated the effects of the antioxidant N-acetylcysteine on TNF-alpha-induced apoptosis in human vascular endothelial cell (cell line ECV304) apoptosis, NO production and lipid peroxidation. Cultured vascular endothelial cell (ECV304) were either not treated (control), or treated with TNF-alpha (40 ng/ml) alone or TNF-alpha in the presence of N-acetylcysteine at 30 mmol/l or 1 mmol/l, respectively, for 24 h. Cell viability was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Cell apoptosis was assessed by flow cytometry. TNF-alpha-induced endothelial cell apoptosis was associated with increased inducible NO synthase but reduced endothelial NO synthase (eNOS) protein expression. NO production and the levels of the lipid peroxidation product malondialdehyde were concomitantly increased. Treatment with NAC at 30 mmol/l restored eNOS expression and further increased NO production as compared to TNF-alpha alone, resulting in improved cell viability and reduced apoptosis. This was accompanied by increased superoxide dismutase activity, increased glutathione peroxidase production and reduced malondialdehyde levels. N-acetylcysteine at 1 mmol/l, however, did not have significant effects on TNF-alpha-induced endothelial cell apoptosis and cell viability despite it slightly enhanced glutathione peroxidase production. N-acetylcysteine attenuation of TNF-alpha-induced human vascular endothelial cell apoptosis is associated with the restoration of eNOS expression.

Acetylcysteine↗
PubMed2006

RNA interference effectively inhibits mRNA accumulation and protein expression of hepatitis C virus core and E2 genes in human cells.

RNA interference (RNAi) has been widely used for the analysis of gene function and represents a new promising approach to develop effective antiviral drugs. In this study, several small interfering RNAs (siRNAs) corresponding to two structural genes (core and E2) of hepatitis C virus (HCV) were designed and in vitro transcribed to explore the possibility of silencing these two genes. The plasmids pEGFP-C and pEGFP-E2, which contain the EGFP reporter gene and the core or E2 gene as silencing targets, were co-transfected with siRNAs into HEK 293T cells. At various time points of post-transfection, core and E2 expression levels were detected by fluorescence microscopy, flow cytometry, Western blotting, and real-time quantitative PCR. The results showed that the mean fluorescence intensity, protein expression, and RNA transcripts of siRNAs transfected cells were significantly reduced. This may provide an approach for the development of novel prophylactic or therapeutic agents for HCV infection.

Blotting, Western↗
PubMed2006

Cch1 mediates calcium entry in Cryptococcus neoformans and is essential in low-calcium environments.

The ability of Cryptococcus neoformans to grow at the mammalian body temperature (37 degrees C to 39 degrees C) is a well-established virulence factor. Growth of C. neoformans at this physiological temperature requires calcineurin, a Ca(2+)/calmodulin-dependent protein phosphatase. When cytosolic calcium concentrations are low ( approximately 50 to 100 nM), calcineurin is inactive and becomes active only when cytosolic calcium concentrations rise ( approximately 1 to 10 microM) through the activation of calcium channels. In this study we analyzed the function of Cch1 in C. neoformans and found that Cch1 is a Ca(2+)-permeable channel that mediates calcium entry in C. neoformans. Analysis of the Cch1 protein sequence revealed differences in the voltage sensor (S4 regions), suggesting that Cch1 may have diminished voltage sensitivity or possibly an alternative gating mechanism. The inability of the cch1 mutant to grow under conditions of limited extracellular calcium concentrations ([Ca(2+)](extracellular), approximately 100 nM) suggested that Cch1 was required for calcium uptake in low-calcium environments. These results are consistent with the role of ScCch1 in mediating high-affinity calcium uptake in Saccharomyces cerevisiae. Although the growth defect of the cch1 mutant under conditions of limited [Ca(2+)](extracellular) ( approximately 100 nM) became more severe with increasing temperature (25 degrees C to 38.5 degrees ), this temperature sensitivity was not observed when the cch1 mutant was grown on rich medium ([Ca(2+)](extracellular), approximately 0.140 mM). Accordingly, the cch1 mutant strain displayed only attenuated virulence when tested in the mouse inhalation model of cryptococcosis, further suggesting that C. neoformans may have a limited requirement for Cch1 and that this requirement appears to include ion stress tolerance.

Amino Acid Sequence↗
PubMed2006

Automated on-line liquid chromatography-photodiode array-mass spectrometry method with dilution line for the determination of bisphenol A and 4-octylphenol in serum.

A novel on-line liquid chromatography-photodiode array detection-mass spectrometry (LC-DAD-MS) system was established with restricted-access media (RAM) pre-column and dilution line combined with a column-switching valve. The serum samples were injected directly onto pre-column under diluted condition by dilution line. After elution of proteins in the serum, the analytes were backflushed onto an ODS analytical column using a six-port column-switching device. The influence of the composition of the mobile phase, for instance, organic modifer, ionic strength, pH, dilution times and the rotation time of the switching valve have been investigated using bisphenol A (BPA) and 4-octyphenol (4-OP) as analytes. The evaluations for peak responses and sensitivity were conducted by MS, and proteins were removed by RAM-column with DAD monitoring at 280 nm. The peak shape was improved by adding a dilution line, especially in the case of large volume injection (LVI), which increased the sensitivity of the analysis. The selective and sensitive quantification of BPA and 4-OP in serum sample could be finished within 25 min. The method had linearity in the range 0.1-500 ng/mL with a limit of quantification for BPA and 4-OP of 0.1 and 0.5 ng/mL, respectively. The recoveries were in the range of 80-101% with less than 9.0% RSDs. This on-line LC-MS method demonstrates potential application to evaluating the exposure and risk of BPA and 4-OP in human.

Benzhydryl Compounds↗