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Biomedical subjects

Gang Liu

Publications and source records attributed to Gang Liu.

At least 19 recordsLinked to original sources

Protein Profiling Identifies Biomarkers for Predicting Disease Severity in Anti-NMDAR Encephalitis.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune neurological disorder characterized by pathogenic antibodies against the NMDAR. A systematic protein profiling approach is warranted to identify biomarkers capable of predicting disease status. An Olink proximity extension assay (PEA) profiled 91 inflammation-related proteins from anti-NMDAR encephalitis patients. Disease severity or prognosis were assessed by CASE score or mRS score at 6-month follow-up. Patients were stratified into distinct molecular clusters using unsupervised clustering. Logistic regression models incorporating selected biomarkers were developed to predict disease severity and prognosis, followed by absolute quantification using ELISA. Patients were classified into four consensus clusters. Clusters 1 and 2 corresponded to the mild group, while Cluster 3 represented the severe group, consistent with CASE score above 6. Cluster 4 showed heterogeneous clinical features. Elevated serum levels of IL-10, IL-6, and SIRT2, as well as increased CSF levels of CXCL10, CXCL11, and MMP10, were positively associated with severe disease. Conversely, several proteins including LTA and CCL11, CCL8, TGFB1, CXCL6 were associated with severe disease or unfavorable 6-month outcomes. A logistic regression model combining serum CXCL6 and CCL11 with CSF MMP10 achieved an area under the curve (AUC) of 0.95 for predicting disease severity. Serum CCL11 alone showed predictive value for 6-month prognosis, with an AUC of 0.79. These findings delineate distinct protein signatures associated with clinical heterogeneity of anti-NMDAR encephalitis. Prediction models incorporating multiple biomarkers may provide an approach for disease severity stratification and prognosis forecast.

Humans↗

Metagenomic insights into microbial drivers of organic micropollutant removal in wastewater-impacted riverbank filtration.

Organic micropollutants (OMPs) in wastewater treatment plant (WWTP) effluent pose persistent risks to aquatic ecosystems and drinking water sources. Riverbank filtration (RBF) is a nature-based treatment process, yet the compartment-specific roles of riverbed sediment and downstream soil in OMP attenuation remain poorly resolved under wastewater-impacted conditions. Here, we combined targeted chemical analysis, OMP property compilation, shotgun metagenomics, EnviPath-based biotransformation annotation, and exploratory network analysis to investigate OMP attenuation in a laboratory-scale RBF system treating real WWTP effluent for 10 months. Nineteen OMPs were monitored along a sequential sediment-soil filtration pathway. Sediment preferentially attenuated hydrophilic or charged compounds, including lidocaine, amantadine, and sotalol, whereas soil contributed more strongly to the attenuation of naproxen, atenolol, and losartan. Metagenomic profiling revealed distinct microbial communities and functional gene repertoires between sediment and soil after long-term operation. Sediment harbored higher relative abundances of genes associated with oxidative xenobiotic transformation, including cytochrome P450-related enzymes, demethylases, dehydrogenases, oxidases, and aromatic compound degradation pathways. An exploratory Spearman network further identified associations among microbial genera, EnviPath-annotated candidate biotransformation genes, and OMP removal rates, including 17 KO-OMP links supported by both correlation and pathway annotation. These findings indicate that sediment and soil develop complementary microbial functional potentials that may support compound-specific OMP attenuation. This study provides a mechanistic basis for optimizing sediment-soil configurations in wastewater-impacted RBF systems and for improving nature-based barriers against diverse OMP mixtures.

Wastewater↗

MED12-STAT1-TAP2 axis regulates CD8 + T cell cytotoxicity and mediates immunotherapy outcome in non-small cell lung cancer.

Although immunotherapy for late-stage non-small cell lung carcinoma (NSCLC) has been clinically utilized, its prognosis remains highly heterogeneous, prompting us to investigate novel predictive immunotherapy biomarkers for NSCLC. We analyzed the correlations between MED12 nonsynonymous mutations and survival, clinical, genomic, transcriptomic information, and immune infiltration information through data mining across multiple datasets. We also investigated the mechanism of MED12 using luciferase assay, Western blot, ChIP-PCR, and siRNA. MED12 is significantly associated with survival in completely independent immunotherapy datasets, including MSKCC (N = 350), Naiyer2015 (N = 34), our own (N = 295) and the pan-cancer dataset, but not in the TCGA dataset, where patients received non-immunotherapy regimens. Mutations in MED12 showed no significant correlation with known metrics (TMB, IPS/CTLA4/PD1 status, PD-1/PD-L1 expression, and TCR/BCR status) or DNA Damage Repair (DDR) pathway mutations, yet they carried independent prognostic information according to the Cox multivariate regression. On the other hand, MED12 mutation is significantly associated with multiple immune-related pathways and immune infiltration of CD8 + T cells and activated NK cells. Lactate dehydrogenase assay revealed that knockdown of TAP2 restored the upregulation of CD8 + T cell cytotoxicity triggered by MED12 knockdown. ChIP-PCR, luciferase assay and siRNA knock down assay indicate that MED12 binds to the promoter region of STAT1 to suppress its transcription, while the transcription factor STAT1 promotes the transcription of TAP2, thus inhibiting the antigen processing and presentation. Collectively, MED12 mutation is an independent and valuable biomarker for predicting the response to immune checkpoint inhibitor (ICI)therapy in NSCLC by modulating CD8 + T cell cytotoxicity via the STAT1/TAP2 axis.

Humans↗

Validation of breast cancer as a risk factor for anxiety and depression: Insights from Mendelian randomization analysis.

This study employed Mendelian randomization (MR) analysis to confirm the association between breast cancer and the risk of anxiety and depression, and to explore the molecular mechanisms by which lipid nanoparticles of ketamine (LNP@Ket) modulate these behaviors in a mouse model of breast cancer. Through single-cell transcriptomic analysis, the study aimed to clarify nuclear factor erythroid 2-related factor 2 (Nrf2)'s role in the development of anxiety and depression in these mice. Analysis of patient data from genome-wide association study (GWAS) databases supported the link between breast cancer, anxiety, and depression. In vivo experiments demonstrated that treating breast cancer mice with LNP@Ket significantly reduced anxiety and depression behaviors. The synthesis of LNP@Ket and its subsequent analysis highlighted its inhibitory effects on these behaviors. Single-cell transcriptomic sequencing identified key cells and genes affected by LNP@Ket treatment, particularly emphasizing Nrf2. Upregulation of Nrf2 in astrocytes increased the expression of antioxidant enzymes and reduced pro-inflammatory cytokines, alleviating anxiety and depression symptoms by inhibiting neuroinflammation and neurodegeneration. This comprehensive study highlights the pivotal role of Nrf2 in the therapeutic efficacy of LNP@Ket for treating anxiety and depression in breast cancer mice.

Anxiety and depression behaviors↗

Genomic insights into the population history of fat-tailed sheep and identification of two mutations that contribute to fat tail adipogenesis.

INTRODUCTION: Since their domestication, domestic sheep (Ovis aries) have been culturally and economically significant farming animals worldwide. Fat-tailed sheep serve as a unique genetic resource for understanding adipogenesis and adaptive evolution in livestock. OBJECTIVES: Several genomic analyses have been conducted on various sheep breeds to elucidate the genome and regulation mechanism of the fat tail trait, prior genomic studies have failed to reconcile conflicting evidence about the genetic basis of tail morphology, particularly regarding the roles of PDGFD and BMP2. METHODS: Here, we conducted whole-genome resequencing of 283 sheep, encompassing 66 domestic breeds and 5 wild ovine species, to investigate the domestication history and selection signatures of fat-tailed sheep. Additionally, we performed transcriptome sequencing on adipose tissue to identify differentially expressed genes and cellular assays to validate these results. RESULTS: Demographic analysis revealed that domestic sheep descended from Asiatic mouflon and fat-tailed sheep began to diverge from thin-tailed sheep approximately 4.4-7.5 thousand years ago in East Asia. Chinese indigenous sheep were classified into Mongolian, Kazakh, Tibetan, and Yunnan populations. The Yunnan population may have experienced more recent genetic introgression from wild species, rather than an independent domestication event. Moreover, many potential regions associated with the fat-tailed phenotype (DDI1, PDGFD, and BMP2) were identified by selective sweep and genome-wide association analyses. Additionally, a fine-scale analysis of fat-tailed and thin-tailed sheep revealed two novel mutations: a G/A missense variant of PDGFD (Chr15: 3900312) and a C/T missense variant of BMP2 (Chr13: 48462350), both of which were significantly associated with tail adiposity. Functional validation demonstrated that mutant A-PDGFD significantly activated PFGFD expression and reduced fat deposition compared to wildtype. The C-BMP2 mutant activated BMP2 expression and promoted preadipocyte fat deposition. CONCLUSION: Our study provides the first evidence that these genes jointly regulate fat tail development through complementary mechanisms: PDGFD promotes adipose expansion, whereas BMP2 modulates energy partitioning. These findings offer new insights into the evolutionary history of fat-tailed sheep and identify potential targets for precision breeding in small ruminants.

Animals↗

Similarities and differences between smoking-related gene expression in nasal and bronchial epithelium.

Previous studies have shown that physiological responses to cigarette smoke can be detected via bronchial airway epithelium gene expression profiling and that heterogeneity in this gene expression response to smoking is associated with lung cancer. In this study, we sought to determine the similarity of the effects of tobacco smoke throughout the respiratory tract by determining patterns of smoking-related gene expression in paired nasal and bronchial epithelial brushings collected from 14 healthy nonsmokers and 13 healthy current smokers. Using whole genome expression arrays, we identified 119 genes whose expression was affected by smoking similarly in both bronchial and nasal epithelium, including genes related to detoxification, oxidative stress, and wound healing. While the vast majority of smoking-related gene expression changes occur in both bronchial and nasal epithelium, we also identified 27 genes whose expression was affected by smoking more dramatically in bronchial epithelium than nasal epithelium. Both common and site-specific smoking-related gene expression profiles were validated using independent microarray datasets. Differential expression of select genes was also confirmed by RT-PCR. That smoking induces largely similar gene expression changes in both nasal and bronchial epithelium suggests that the consequences of cigarette smoke exposure can be measured in tissues throughout the respiratory tract. Our findings suggest that nasal epithelial gene expression may serve as a relatively noninvasive surrogate to measure physiological responses to cigarette smoke and/or other inhaled exposures in large-scale epidemiological studies.

Adult↗

HIV-1 viral fitness estimation using exchangeable on subsets priors and prior model selection.

The phenotype-genotype problem is a fundamental problem of biology where an organism's genotype (genetic information) predicts its phenotype (observable characteristic). Viral fitness, defined as the reproductive capacity of a virus compared to a standard, is a continuous phenotype. We construct models to predict viral fitness as a function of mutation away from the standard wildtype virus. Data of this nature are difficult to analyse because there are potentially many more parameters than observations. We treat this issue as a regression problem using a prior with both a shrinkage component and a variable selection component. The key to practical implementation of the model is the prior specification for the regression coefficients. We use results from the scientific literature to construct several informative exchangeable within subsets priors (ESP). We use prior model selection (PMS) to select among our priors. Two novel graphics present results from five models each with 71 predictors.

Codon↗

Adamantyl-substituted retinoid-related molecules bind small heterodimer partner and modulate the Sin3A repressor.

6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalenecarboxylic acid (CD437/AHPN) and 4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC/MM002) are inducers of apoptosis of malignant cells both in vitro and in vivo. Numerous mechanisms have been proposed for how these compounds exert this effect. This report shows that AHPN/3-Cl-AHPC binds specifically to the orphan nuclear receptor small heterodimer partner (SHP; NR0B2), and this binding promotes interaction of the receptor with a corepressor complex that minimally contains Sin3A, N-CoR, histone deacetylase 4, and HSP90. Formation of the SHP-Sin3A complex is essential for the ability of AHPN and 3-Cl-AHPC to induce apoptosis, as both knockout SHP and knockdown of Sin3A compromise the proapoptotic activity of these compounds but not other apoptosis inducers. These results suggest that AHPN/3-Cl-AHPC and their analogues are SHP ligands and their induction of apoptosis is mediated by their binding to the SHP receptor.

Adamantane↗

Preformed precursor of microporous aluminophosphate coating on mesoporous SBA-15: synthesis, characterization, and catalytic property for selective O-methylation of catechol.

The synthesis of mesoporous SBA-15 coated with the preformed precursor of microporous aluminophosphate (AlPO) has been reported. The physicochemical properties of the coated samples were investigated by using XRD, FT-IR, N(2)-adsorption, ICP, (29)Si MAS NMR, NH(3)-TPD and CO(2)-TPD. The characterization results suggest that the nanometer-scaled zeolite units are present on the wall surface of SBA-15, thus bringing the weak acid-base characteristics to the resulting mesoporous materials, and that the acid-base properties of these materials can be modified by the aging treatment in glycol. Moreover, vapor-phase O-methylation of catechol with methanol has been studied on these coated samples as catalysts. It is found that the coated sample bearing suitable weak acid-base sites exhibits the relatively high activity and selectivity to guaiacol.

Journal Article↗

A gene encoding alanine racemase is involved in spore germination in Bacillus thuringiensis.

Alanine racemase is a major component of the exosporium of Bacillus cereus spores. A gene homologous to that of alanine racemase (alrA) was cloned from Bacillus thuringiensis subsp. kurstaki, and RT-PCR showed that alrA was transcribed only in the sporulating cells. Disruption of alrA did not affect the growth and sporulation of B. thuringiensis, but promoted L-alanine-induced spore germination. When the spore germination rate was measured by monitoring DPA release, complementation of the alrA disruptant reduced the rate of L-alanine-induced spore germination below that of even wild-type spores. As previously reported for spores of other Bacillus species, D-alanine was an effective and competitive inhibitor of L-alanine-induced germination of B. thuringiensis spores. D-cycloserine alone stimulated inosine-induced germination of B. thuringiensis spores in addition to increasing L-alanine-induced germination by inhibiting alanine racemase. D-alanine also increased the rate of inosine-induced germination of wild-type spores. However, D-alanine inhibited inosine-induced germination of the alrA disruptant spores. It is possible that AlrA converted D-alanine to L-alanine, and this in turn, stimulated spore germination in B. thuringiensis. These results suggest that alrA plays a crucial role in moderating the germination rate of B. thuringiensis spores.

Alanine Racemase↗

Localization of TGF-beta signaling intermediates Smad2, 3, 4, and 7 in developing and mature human and mouse kidney.

Smad proteins are signaling intermediates of the TGF-beta superfamily and are involved in a range of biological activities including development and immune responses. We studied the expression of TGF-beta-receptor activated Smads (Smad2 and Smad3), the common partner Smad (Smad4), an inhibitory Smad (Smad7), and the activated (phosphorylated) Smad2 (pSmad2) in developing and adult kidneys of humans and mice. These studies demonstrate associated expression of these Smads in multiple renal cell types in all developmental stages and in mature non-diseased kidneys. Smad expression is in general most widespread at the earliest stages of nephron development and diminishes as components of the nephrons become more differentiated. Paucity of Smad expression in mesangial cells in contrast to widespread expression of these Smads in glomerular visceral epithelial cells in both developing and mature kidneys was remarkable. Divergent and less extensive expression of Smad4, compared with other Smad proteins, was also demonstrated in tubules of human kidneys. Based on the observed expression patterns, these findings demonstrate, for the first time, expression of the TGF-beta-receptor-activated Smad2 and Smad3, the common mediator Smad4, and the inhibitory Smad7 in the developing human fetal kidney, extending observations previously made in rodent systems to humans.

Adult↗

Visible light photocatalyst: iodine-doped mesoporous titania with a bicrystalline framework.

Iodine-doped (I-doped) mesoporous titania with a bicrystalline (anatase and rutile) framework was synthesized by a two-step template hydrothermal synthesis route. I-doped titania with anatase structure was also synthesized without the use of a block copolymer as a template. The resultant titania samples were characterized by X-ray diffraction, Raman spectroscopy, Fourier transform infrared, nitrogen adsorption, transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-visible absorption spectroscopy. Both I-doped titania samples, with and without template, show much better photocatalytic activity than commercial P25 titania in the photodegradation of methylene blue under the irradiation of visible light (>420 nm) and UV-visible light. Furthermore, I-doped mesoporous titania with a bicrystalline framework exhibits better activity than I-doped titania with anatase structure. The effect of rutile phase in titania on the adsorptive capacity of water and surface hydroxyl, and photocatalytic activity was investigated in detail. The excellent performance of I-doped mesoporous titania under both visible light and UV-visible light can be attributed to the combined effects of bicrystalline framework, high crystallinity, large surface area, mesoporous structure, and high visible light absorption induced by I-doping.

Journal Article↗

Characterization and surface reactivity of ferrihydrite nanoparticles assembled in ferritin.

Ferrihydrite nanoparticles with nominal sizes of 3 and 6 nm were assembled within ferritin, an iron storage protein. The crystallinity and structure of the nanoparticles (after removal of the protein shell) were evaluated by high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), and scanning tunneling microscopy (STM). HRTEM showed that amorphous and crystalline nanoparticles were copresent, and the degree of crystallinity improved with increasing size of the particles. The dominant phase of the crystalline nanoparticles was ferrihydrite. Morphology and electronic structure of the nanoparticles were characterized by AFM and STM. Scanning tunneling spectroscopy (STS) measurements suggested that the band gap associated with the 6 nm particles was larger than the band gap associated with the 3 nm particles. Interaction of SO2(g) with the nanoparticles was investigated by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and results were interpreted with the aid of molecular orbital/density functional theory (MO/DFT) frequency calculations. Reaction of SO2(g) with the nanoparticles resulted primarily in SO(3)2- surface species. The concentration of SO3(2-) appeared to be dependent on the ferrihydrite particle size (or differences in structural properties).

Ferric Compounds↗

ZHX proteins regulate podocyte gene expression during the development of nephrotic syndrome.

Transcriptional regulation of podocyte gene expression in primary glomerular disease is poorly understood. In this study, we demonstrate a prominent role of members of the ZHX (zinc fingers and homeoboxes) family of proteins in regulating podocyte gene expression during the development of nephrotic syndrome. While studying mechanisms of glomerular disease, rat ZHX3 was cloned from a down-regulated gene fragment; its cellular localization, DNA binding, and transcriptional repressor properties were characterized; and its ability to influence podocyte gene expression directly or via ZHX1 and ZHX2 was studied. In eukaryotic promoters, ZHX3 bound to the CdxA binding motif. ZHX proteins were mostly sequestered in the non-nuclear compartment in the normal in vivo podocyte by virtue of heterodimer formation, and loss of heterodimerization was associated with entry into the nucleus. In experimental minimal change disease, ZHX3 was transiently down-regulated prior to the onset of proteinuria, and recovery of expression was associated with migration of ZHX3 protein into the nucleus and the development of proteinuria. This expression pattern mirrored the increased nuclear ZHX3 expression noted in vivo in the podocytes in human minimal change disease biopsies. In vitro, migration of ZHX3 protein into the nucleus during recovery from transient ZHX3 knockdown reproduced the gene expression profile of in vivo minimal change disease. Severe sustained knockdown of ZHX3 caused down-regulation of genes involved in focal sclerosis, including WT1, mediated mostly by increased nuclear entry of ZHX2 and ZHX1. In summary, ZHX proteins are major transcriptional mediators of podocyte disease.

Animals↗

Hemodynamic effects of potent and selective JNK inhibitors in anesthetized rats: implication for targeting protein kinases in metabolic diseases.

The hemodynamic effects of a series of potent and selective 4-aminopyridine carboxamide-based pan-JNK inhibitors were assessed in an anesthetized rat model. The effects of these agents on mean arterial pressure, heart rate, cardiac contractility, and peripheral vascular resistance are described, and the implication for targeting protein kinases in metabolic diseases is discussed.

Aminopyridines↗

Effect of five triterpenoid compounds from the buds of Aralia elata on stimulus-induced superoxide generation, tyrosyl phosphorylation and translocation of cytosolic compounds to the cell membrane in human neutrophils.

The buds of Aralia elata (Miq.) Seem (Japanese angelica tree) have long been used as a tonic, antiarthritic and antidiabetic agent in China and Japan. We have isolated five triterpenoids, congmuyanosides A, C, D, echinocystic acid and 3-O-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-hederagenin from the buds of Aralia elata , and investigated their effects on stimulus-induced superoxide generation in human neutrophils. Congmuyanoside A, echinocystic acid and 3-O-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-hederagenin suppressed the superoxide generation induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) in a concentration-dependent manner. Congmuyanosides C, D and echinocystic acid significantly suppressed the superoxide generation induced by phorbol 12-myristate 13-acetate (PMA) and arachidonic acid (AA). The compounds also suppressed fMLP- and AA-induced tyrosyl or PMA-induced serine/threonine phosphorylation and translocation of cytosolic compounds, p47 (phox), p67 (phox) and Rac to the cell membrane.

Aralia↗

Structure-activity relationships for a novel series of thiazolyl phenyl ether derivatives exhibiting potent and selective acetyl-CoA carboxylase 2 inhibitory activity.

Structure-activity relationships for a recently discovered thiazolyl phenyl ether series of acetyl-CoA carboxylase (ACC) inhibitors were investigated. Preliminary efforts to optimize the series through modification of the distal aryl ether moiety of the lead scaffold resulted in the identification of compounds exhibiting low-nanomolar potency and isozyme-selective ACC2 activity.

Acetyl-CoA Carboxylase↗