Biomedical subjects

Xia Zhang

Publications and source records attributed to Xia Zhang.

At least 19 recordsLinked to original sources

PubMed2026

Molecular epidemiology and phylogeographic architecture of oncogenic intracellular bacteria in cervical cancer patients across Northern China.

BACKGROUND: Oncogenic intracellular bacteria, including Chlamydia trachomatis, Mycoplasma genitalium, and Fusobacterium nucleatum, have emerged as significant contributors to cervical carcinogenesis. Despite growing interest in microbial oncology, the molecular epidemiological landscape and phylogeographic distribution of these pathogens in Northern China remain poorly characterized. This study aimed to determine the prevalence, co-infection patterns, genotypic diversity, and spatial phylogeographic clustering of oncogenic intracellular bacteria among cervical cancer patients across five provinces of Northern China. METHODS: A cross-sectional, multi-center study was conducted between March 2022 and November 2024 across Shaanxi, Heilongjiang, Beijing, Shandong, and Inner Mongolia. Cervical swab specimens were collected from 1247 confirmed cervical cancer patients. Pathogen detection was performed using multiplex real-time polymerase chain reaction, 16S rRNA gene amplicon sequencing, and whole-genome sequencing. Phylogeographic analyses employed maximum likelihood and Bayesian evolutionary inference frameworks. Statistical analyses included multivariate logistic regression and geographic information system-based spatial clustering. RESULTS: The overall prevalence of at least one oncogenic intracellular bacterium was 68.3% (n = 852). Chlamydia trachomatis was the most prevalent pathogen detected in 41.2% of participants. Co-infection with two or more bacteria was identified in 29.7% of cases and was independently associated with advanced-stage cervical cancer (adjusted odds ratio = 2.87; 95% confidence interval: 1.94 to 4.23; p < 0.001). Phylogeographic analysis revealed three distinct molecular clades with evidence of bidirectional gene flow between Shaanxi and Heilongjiang. Whole-genome sequencing identified 14 novel virulence gene variants not previously characterized in Chinese clinical isolates. CONCLUSIONS: Oncogenic intracellular bacteria are highly prevalent and genotypically diverse among cervical cancer patients in Northern China. The identified phylogeographic clustering and novel virulence variants have direct implications for regional screening programs, targeted antimicrobial strategies, and the development of region-specific molecular diagnostic panels.

Cervical cancer↗

PubMed2026

Systematic Identification of Therapeutic Targets and Repurposed Drugs for Stroke: From Genome Causal Analysis to Multilevel Validation.

BACKGROUND: Stroke is a severe cerebrovascular disease characterized by narrow time windows and complications. This study aimed to identify novel drug targets and repurposed drugs for stroke. METHODS: This study used expression quantitative trait loci data from druggable genes in brain and blood as instrumental variables. Mendelian randomization, colocalization, and phenome-wide Mendelian randomization were applied to evaluate causal relationships and potential side effects, with stroke and ischemic stroke as primary outcomes. Preclinical validation used oxygen-glucose deprivation/reperfusion and middle cerebral artery occlusion/reperfusion models. Pharmacological and behavioral assessments evaluated the therapeutic potential of candidate targets and drugs. Additionally, proteomic sequencing was performed following GGCX (γ-glutamyl carboxylase) overexpression to explore its biological functions. RESULTS: Elevated GGCX expression in brain and blood was potentially causally associated with reduced risk of stroke and ischemic stroke, supported by colocalization evidence, although potential cardiovascular risks could not be excluded. Drug repositioning identified ifenprodil as a candidate agent that reduced infarction volume, improved motor and cognitive functions, and reversed GGCX downregulation in mice. Ifenprodil treatment and GGCX overexpression alleviated oxygen-glucose deprivation/reperfusion-induced injury and upregulated GGCX expression. Mechanistically, GGCX conferred neuroprotection by regulating protein homeostasis, suppressing inflammation, promoting metabolic recovery, and modulating nuclear transcriptional regulation. CONCLUSIONS: This study established a potential causal link between GGCX and stroke risk, particularly ischemic stroke. GGCX represents a promising therapeutic target for ischemic stroke. Targeted GGCX expression upregulation and drug repurposing, particularly ifenprodil, may offer novel therapeutic avenues. Further validation is warranted to assess clinical efficacy and safety.

Animals↗

PubMed2026

Screening and identification of key genes related to the immune microenvironment of rectal cancer influenced by radiotherapy based on bioinformatics methods.

OBJECTIVE: Radiotherapy (RT) plays a crucial role in the comprehensive treatment of rectal cancer. However, the impact of radiotherapy on the tumor microenvironment (TME), especially its effect on immune cell infiltration and immune-related gene expression, has not been fully studied. This study aims to screen and analyze key genes related to the immune microenvironment of rectal cancer influenced by radiotherapy based on bioinformatics methods for the purpose of identifying potential biomarkers and providing new insights for the personalized therapy of rectal cancer. METHODS: Using data from the Public Gene Expression Database (GEO) and the Cancer Genomics Database (TCGA), the impact of radiotherapy on the immune microenvironment of rectal cancer was explored using bioinformatics tools. Through screening differentially expressed genes (DEGs), correlation analysis, TIMER database analysis, immune infiltration score, and correlation analysis between key genes and prognosis, the effects of radiotherapy on the immune microenvironment of rectal cancer were investigated. RESULTS: Totally 7 upregulated and 4 downregulated differentially expressed genes were identified, among which MASP1, LTK, SLC9A3R2 were negatively correlated with myeloid suppressor cell infiltration (MDSCs), while ZP2 was positively correlated. The expression of MASP1 and SLC9A3R2 was closely related to the level of immune cell infiltration and played significant roles in the immune microenvironment. High expression of MASP1 was significantly correlated with survival benefits from immune checkpoint inhibitor therapy, while SLC9A3R2 was closely related to the efficacy of PD-L1 inhibitors and CTLA4 inhibitors. CONCLUSIONS: MASP1 and SLC9A3R2, as two key genes that may be related to the immune microenvironment of rectal cancer radiotherapy, deserve further exploration of their roles in the mechanism. The combination of radiotherapy and immunotherapy holds promising prospects in the treatment of rectal cancer, and exploration of related mechanisms will provide new strategies and targets for the treatment of various tumors and rectal cancer.

Bioinformatics↗

PubMed2026

Multi-omics revealed the effects of rumen to blood path on early lactation performance in transition dairy cows.

BACKGROUND: The transition period is vitally important to the life cycle of dairy cows. However, the function of the microbiota during both pre- and post-partum and their relationship with ruminal, plasma, and milk metabolites still require systematic investigation. To address this, the 7 highest- and 7 lowest-performing animals among a cohort of 100 dairy cows were selected based on their postpartum energy-corrected milk yield. Rumen fluid and plasma samples were collected during both pre- and post-partum periods, whereas milk samples were obtained postpartum. Shotgun metagenomics of rumen contents in addition to metabolomics of rumen, plasma, and milk samples were performed to evaluate the associations between ruminal microbes and early lactation performance in transition dairy cows. RESULTS: Compared with prepartum cows, postpartum high-yield cows had greater concentrations of ruminal volatile fatty acids and plasma total bile acid. Moreover, plasma urea nitrogen and most amino acids, peptides, and their derivatives in plasma and milk were increased in postpartum high-yield cows, relative to postpartum low-yield cows. Metagenomic analysis revealed that the relative abundances of several species within the Prevotella, Succinimonas, Succinatimonas, and Methanosphaera increased, while other bacteria belong to Alistipes and Bacteroides, and archaeal Methanobrevibacter species decreased in postpartum cows, particularly in postpartum high-yield cows. Co-occurrence network and correlation analysis suggested that Prevotella and Succinatimonas were negatively correlated to Alistipes, Bacteroides, and Methanobrevibacter, potentially contributing to the nutritionally efficient phenotype of postpartum high-yield cows. A metabolic pathway analysis of our metagenomic data revealed that postpartum high-yield cows possessed more microbial genes involved in starch utilization and amino acid synthesis, while a wide range of microbial genes involved in cellulose utilization, acetogenesis, and amino acid degradation were found in prepartum cows with low-yield in postpartum. A structural equation model analysis showed that the increased relative abundances of Prevotella tf.2-5 and Succinatimonas CAG_777 were related to greater concentrations of plasma chenodeoxycholic acid glycine conjugate, milk 5-Methoxytryptophan, and energy-corrected milk yield. Finally, pan-genomic analysis confirmed that Alistipes, Bacteroides, and Methanobrevibacter possess genetic conservation of both hydrogenases and dehydrogenases, which may contribute to energy loss in the rumen via hydrogen dissipation. CONCLUSION: In summary, our findings provide a fundamental understanding of how microbiome-dependent mechanisms contribute to early lactation performance in dairy cows during the transition period. The increased abundance of Prevotella, Succinimonas, and Succinatimonas in postpartum cows suggest that they are important microbes during the transition period and may help in coping with metabolic challenges, while improving nutrient utilization efficiency during this period. Our study underscores the importance of the ruminal microbiome during the transition period and highlights the need for rumen-based nutritional intervention strategies to improve production efficiency in ruminants. Video Abstract.

Animals↗

PubMed2026

Third-generation whole-genome sequencing reveals the role of CNTNAP2 as a tumor suppressor gene in high-risk neuroblastomas.

BACKGROUND: Neuroblastoma is a common and aggressive pediatric sympathetic nervous system tumor. Genomic structural variants (SVs) contribute substantially to neuroblastoma, yet remain under-characterized in high-risk neuroblastomas. We aimed to elucidate neuroblastoma pathogenesis using third-generation whole-genome sequence high-risk cases to identify driver aberrations and explore potential therapeutic strategies. METHODS: We analyzed third-generation whole-genome sequencing data of 20 high-risk neuroblastoma samples and combined the findings with those obtained from the analysis of clinical samples, in vitro models, and public datasets. RESULTS: The contactin-associated protein-like 2 (CNTNAP2) gene was observed to be frequently aberrated because of structural variants in high-risk neuroblastoma samples. CNTNAP2 expression was significantly correlated with favorable histology and could be used to predict prognosis using clinical samples and neuroblastoma datasets. Overexpression and knockdown experiments and transcriptomic analysis revealed that CNTNAP2 was primarily involved in neuronal differentiation and axon guidance pathways; moreover, CNTNAP2 was required for neuroblastoma differentiation and affected cancer stemness. Immunoprecipitation and mass spectrometry revealed that CNTNAP2 interacted with cytoskeletal proteins like drebrin 1 (DBN1) and myosin-heavy chain 9 (MYH9). CNTNAP2 dynamically reorganises actin and microtubules for DBN1-mediated neuronal differentiation. CNTNAP2 also reduces CTNNB1 transcription and β-catenin pathway activation by inhibiting MYH9 nuclear translocation. CNTNAP2 overexpression in neuroblastoma cell lines resulted in cell cycle arrest, decreased cell proliferation and metastasis. CONCLUSIONS: The recurrent loss of CNTNAP2 in neuroblastoma contributes to an aggressive phenotype by impairing neuronal differentiation and increasing cancer stemness. These findings may serve as a foundation for developing therapeutic strategies to overcome barriers to differentiation.

Humans↗

PubMed2026

Discovery of the Underlying Mechanism of Ginger Juice Processed Ziziphi Spinosae Semen for Its Sedative-Hypnotic Effect on Insomnia Mice via Regulation of HPA Axis and cAMP/PKA Signaling Pathway.

Based on Traditional Chinese Medicine (TCM) theory, the efficacy and mechanism of Ginger juice processed Ziziphi Spinosae Semen (GJPZSS) for treating insomnia, particularly stress-related types, were investigated to provide empirical evidence. An insomnia model was induced in mice by DL-4-chlorophenylalanine (PCPA) and chronic tail clamping. The sedative effect was evaluated by behavioral tests. Serum components from GJPZSS were analyzed by UHPLC-Q-TOF-MS/MS, and 64 potential targets were identified. The cAMP signaling pathway was enriched as the core pathway by Kyoto Encyclopedia of genes and genomes (KEGG) analysis and was validated by molecular docking. GJPZSS was demonstrated to prolong sleep time, reduce immobility time, increase 5-hydroxytryptamine (5-HT) and gamma-aminobutyric acid (GABA) levels, decrease hypothalamic-pituitary-adrenal (HPA) axis levels, and suppress neuronal death. The reduction of the cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP-response element binding protein (CREB) and brain-derived neurotrophic factor (BDNF) in the brain was also significantly inhibited. It was concluded that the sleep-improving effect of GJPZSS was mediated through the regulation of the HPA axis and the cAMP/PKA/CREB/BDNF signaling pathway.

Animals↗

PubMed2007

Activation of the MAPK, ERK, following Leishmania amazonensis infection of macrophages.

IL-10 is a critical cytokine in determining host susceptibility to Leishmania spp. We previously demonstrated that macrophage-derived IL-10 could contribute to disease exacerbation, but the mechanisms whereby Leishmania infections led to IL-10 induction were not fully understood. In this study, we demonstrated that infection of macrophages with Leishmania amazonensis amastigotes led to the activation of the MAPK, ERK1/2. This activation was required, but not sufficient for IL-10 induction. In addition to ERK activation, an inflammatory stimulus, such as low m.w. hyaluronic acid from the extracellular matrix, must also be present. The combination of these two signals resulted in the superinduction of IL-10. We also demonstrated that IgG on the surface of Leishmania amastigotes was required to achieve maximal IL-10 production from infected macrophages. Surface IgG engages macrophage FcgammaR to induce ERK activation. Macrophages lacking FcgammaR, or macrophages treated with an inhibitor of spleen tyrosine kinase, the tyrosine kinase that signals via FcgammaR, failed to activate ERK and consequently failed to produce IL-10 following infection with Leishmania amastigotes. We confirmed that ERK1/2 activation led to the phosphorylation of histone H3 at the IL-10 promoter, and this phosphorylation allowed for the binding of the transcription factor, Sp1, to the IL-10 promoter. Finally, the administration of U0126, an inhibitor of ERK activation, to infected mice resulted in decreased lesion progression with reduced numbers of parasites in them. Thus, our findings reveal an important role of MAPK, ERK signaling in the pathogenesis of Leishmania infection.

Animals↗

PubMed2007

Effects of delayed excision of oviducts/ovaries on mouse oocytes and embryos.

To achieve the best and reproducible results of experiments, effects of delayed excision of oviducts/ovaries on mouse ovarian/ovulated oocytes and embryos have been studied. Oviducts/ovaries were excised at different times after death of mice and effects of the postmortem interval on ovarian/ovulated oocytes and embryos were analyzed. When oviduct excision was delayed 10 min, many ovulated oocytes lysed or underwent in vitro spontaneous activation, and this postmortem effect aggravated with the extension of postmortem interval and oocyte aging. Oocytes from different mouse strains responded differently to delayed oviduct removal. Delayed oviduct excision did not cause lysis of zygotes or embryos but compromised their developmental potential. When ovaries were excised at 30 min after death, percentages of atretic follicles increased while blastocyst cell number declined significantly after oocyte maturation in vitro. Preservation of oviducts in vitro, in intact or opened abdomen at different temperatures and histological analysis of oviducts from different treatments suggested that toxic substance(s) were secreted from the dying oviducts which induced oocyte lysis and spontaneous activation and both this effect itself and the sensitivity of oocytes to this effect was temperature dependent. It is concluded that a short delay of oviduct/ovary removal had marked detrimental effects on oocytes and embryos. This must be taken into account in experiments using oocytes or embryos from slaughtered animals. The data may also be important for estimation of the time of death in forensic medicine and for rescue of oocytes from deceased valuable or endangered mammals.

Animals↗

PubMed2006

Recent advances in basic neurosciences and brain disease: from synapses to behavior.

Understanding basic neuronal mechanisms hold the hope for future treatment of brain disease. The 1st international conference on synapse, memory, drug addiction and pain was held in beautiful downtown Toronto, Canada on August 21-23, 2006. Unlike other traditional conferences, this new meeting focused on three major aims: (1) to promote new and cutting edge research in neuroscience; (2) to encourage international information exchange and scientific collaborations; and (3) to provide a platform for active scientists to discuss new findings. Up to 64 investigators presented their recent discoveries, from basic synaptic mechanisms to genes related to human brain disease. This meeting was in part sponsored by Molecular Pain, together with University of Toronto (Faculty of Medicine, Department of Physiology as well as Center for the Study of Pain). Our goal for this meeting is to promote future active scientific collaborations and improve human health through fundamental basic neuroscience researches. The second international meeting on Neurons and Brain Disease will be held in Toronto (August 29-31, 2007).

Behavior↗

PubMed2006

Increased frequencies of CD8+ T lymphocytes recognizing wild-type p53-derived epitopes in peripheral blood correlate with presence of epitope loss tumor variants in patients with hepatocellular carcinoma.

Wild-type (WT) sequence p53 peptides are attractive candidates for broadly applicable cancer vaccines. The aim of this study was to evaluate the potential of a WT p53-based immunotherapeutic approach for patients with hepatocellular carcinoma (HCC). Circulating CD8+ T cells specific for WT p53(149-157) and WT p53(264-272) HLA-A*0201 restricted epitopes were directly identified in the peripheral blood by the use of peptide/HLA-A2.1 tetramers in 24 HCC patients. Cytotoxic T lymphocyte (CTL) activity after WT p53 peptide-specific stimulation was assessed by analysis of granzyme B and interferon-gamma mRNA transcription, using a quantitative real-time polymerase chain reaction assay. Tumor immunophenotyping was performed to evaluate the p53 status, the expression of major histocompatibility complex (MHC) and costimulatory molecules in freshly isolated tumor cells. HCC patients exhibited significantly higher frequencies of WT p53-specific memory CD8+ T cells and stronger WT p53-specific CTL activity, when compared with healthy controls. Increased frequencies of p53-specific CD8+ T cells and their activity correlated with selective HLA-A2 allele loss and reduced costimulatory molecule expression of tumor cells. Moreover, augmented numbers of p53-specific T cells coincided with high MHC class II expression in tumor cells but were inversely related to the T status of the tumor node metastasis staging system. Our results indicate the existence of natural immunosurveillance and tumor immune evasion, involving a T cell response against WT p53 tumor antigen in patients with HCC. These findings may have important implications for the future development of cancer vaccines.

Aged↗

PubMed2006

The serotonin 5-HT1D receptor gene and attention-deficit hyperactivity disorder in Chinese Han subjects.

Attention-deficit/hyperactivity disorder (ADHD) is a heritable disease. Serotonin is one of the neurotransmitters involved in the etiology of ADHD. Serotonin-1D receptors are autoreceptors which can regulate the release of serotonin in brain, so the HTR1D gene may be predisposing. The current study genotyped two variants of HTR1D gene in 272 ADHD trios of Chinese ethnicity, that is 1350T > C in the coding region and 1236A > G in 3'-UTR by the use of transmission disequilibrium test (TDT). The A allele of the 1236A > G polymorphism exhibited both a trend toward preferential transmission to ADHD probands (chi2 = 3.815, P = 0.051) and a significant preferential transmission to probands of ADHDC (chi2 = 4.198, P = 0.040). Additional polymorphisms in this gene need to be studied further.

Asian People↗

PubMed2006

Effects of species and cellular activity of oviductal epithelial cells on their dialogue with co-cultured mouse embryos.

An efficient co-culture system, especially with oviductal or uterine epithelial cells, is important not only for the production of high quality embryos, but also for the study of the molecular dialogue between embryos and their maternal environment. Although mouse embryos have been co-cultured successfully with oviductal epithelial cells (OECs) from several species, studies on the effects of species and functionality of OECs are few. Reports concerning the necessity of direct contact between the embryo and OECs and about the culture of mouse embryos in medium conditioned with heterologous OECs have been controversial. In this study, pronuclear embryos from Kunming mice, characterized by an obvious two-cell block in vitro, were co-cultured with mouse, goat, and chick OECs. The functionality of OECs was determined by analyzing the cell cycle, apoptosis, the numbers of mitochondria and cilia, and the ability both to support embryonic development and to remove hypoxanthine from the culture medium. The necessity of direct contact between OECs and embryos was studied by repeated renewal of culture medium with fresh conditioned medium, the culture of embryos in plastic wells connected by tunnels to wells with OEC monolayers, and the co-culture of embryos separated from OECs by a filter. Both goat and chick OECs supported mouse embryonic development, but their embryotrophic lifespan was shorter than that of the mouse OECs. Whereas media conditioned with mouse OECs supported mouse embryonic development satisfactorily, medium conditioned with goat OECs supported little development. Immediate dialogue between heterologous OECs and embryos was essential for efficient co-culture, whereas direct contact between the two cell types was not; neither dialogue nor contact was needed between isologous OECs and embryos. Embryotrophic activity and the ability to remove hypoxanthine from conditioned medium declined with time after confluence and number of passages of OECs, mainly because of apoptosis and dedifferentiation. Thus, the species and functionality of OECs have profound effects on their molecular dialogue with co-cultured embryos, and efficient co-culture depends upon both positive and negative conditioning.

Animals↗

PubMed2006

The comparative study of magnetic resonance angiography diagnosis and pathology of blunt vertebral artery injury.

STUDY DESIGN: Observational and comparative study of the vertebral artery injury detected by 2-dimensional (2-D) time-of-flight magnetic resonance angiography (MRA) for admitting patients. Construct a strike-induced flexion injury model of cervical spine with blunt vertebral artery injury in dogs. OBJECTIVES: To evaluate the value of MRA for diagnosing vertebral artery injury in cervical spinal trauma patients, and conduct a comparative study of MRA image and pathology of blunt vertebral artery injury in an animal experiment. SUMMARY OF BACKGROUND DATA: The 2-D time-of-flight MRA is the most important method for diagnosing vertebral artery injury. However, there is still controversy over MRA's accuracy in detecting vertebral artery injury of varying degrees. In addition, to our knowledge, no animal studies regarding this subject have been found in the literature so far. METHODS: In a clinical study, 319 patients with close cervical spinal trauma underwent 2-D time-of-flight MRA prospective examination. The 2-D time-of-flight MRA detected vertebral artery injury in 52 of the 319 subjects. Of the 52 patients, 51 had unilateral vertebral artery injuries, including 22 injuries on the left vertebral artery and 29 on the right vertebral artery. One case involved bilateral vertebral artery injury. In an animal experiment, the strike-induced flexion injury model of cervical spine was constructed based on an animal experiment with 26 adult dogs. A radiograph was taken immediately after injury, and 2-D time-of-flight MRA was taken in 24-36 hours. The vertebral artery sample was then harvested for pathologic examination. RESULTS: In the animal experiment, cervical facet dislocation occurred in 14 of the 26 dogs. Of the 26 dogs, 7 had unilateral vertebral artery injury as detected by MRA. There were 2 dogs that had incomplete blood flow imaging on one side of the vertebral artery, which MRA diagnosed as suspect positive. There were no vertebral artery injuries in the other 17 dogs. The vertebral artery sample of all 26 dogs underwent the pathologic study. Of the 7 dogs with positive MRA, 4 had disruption of the intima and media, and 3 had disruption of the intima. Of the 2 dogs with suspicious positive MRA diagnosis, 1 had no intima injury, while the other had intima disruption and late mural thrombus. There was no intima injury in the 17 dogs with negative MRA findings. CONCLUSIONS: The 2-D time-of-flight MRA is an effective diagnostic method for blunt vertebral artery injury. It may have difficulties differentiating spasm, small disruption of the intima from others under certain conditions.

Adolescent↗

PubMed2006

Biochemical and functional characterization of three activated macrophage populations.

We generated three populations of macrophages (Mphi) in vitro and characterized each. Classically activated Mphi (Ca-Mphi) were primed with IFN-gamma and stimulated with LPS. Type II-activated Mphi (Mphi-II) were similarly primed but stimulated with LPS plus immune complexes. Alternatively activated Mphi (AA-Mphi) were primed overnight with IL-4. Here, we present a side-by-side comparison of the three cell types. We focus primarily on differences between Mphi-II and AA-Mphi, as both have been classified as M2 Mphi, distinct from Ca-Mphi. We show that Mphi-II more closely resemble Ca-Mphi than they are to AA-Mphi. Mphi-II and Ca-Mphi, but not AA-Mphi, produce high levels of NO and have low arginase activity. AA-Mphi express FIZZ1, whereas neither Mphi-II nor Ca-Mphi do. Mphi-II and Ca-Mphi express relatively high levels of CD86, whereas AA-Mphi are virtually devoid of this costimulatory molecule. Ca-Mphi and Mphi-II are efficient APC, whereas AA-Mphi fail to stimulate efficient T cell proliferation. The differences between Ca-Mphi and Mphi-II are more subtle. Ca-Mphi produce IL-12 and give rise to Th1 cells, whereas Mphi-II produce high levels of IL-10 and thus, give rise to Th2 cells secreting IL-4 and IL-10. Mphi-II express two markers that may be used to identify them in tissue. These are sphingosine kinase-1 and LIGHT (TNF superfamily 14). Thus, Ca-Mphi, Mphi-II, and AA-Mphi represent three populations of cells with different biological functions.

Animals↗

PubMed2006

Identification of a drought tolerant introgression line derived from Dongxiang common wild rice (O. rufipogon Griff.).

Construction of introgression lines using cultivated rice as recipient and wild rice is a novel approach to explore primitive and broad genetic resources in rice breeding. We recently generated a set of 159 introgression lines via a backcrossing program using an elite Indica cultivar rice Guichao 2 (O. sativa L. ssp. indica) as recipient and a common wild rice Dongxiang accession (O. rufipogon Griff.) as donor. In this study, we have evaluated the previously constructed 159 introgression lines for drought-tolerance. A total of 12 quantitative trait loci (QTLs) related to drought tolerance were mapped. Furthermore, a drought tolerant introgression line, IL23, was identified and characterized. Genotype analysis of IL23 demonstrated that IL23 contained two QTLs associated with drought tolerance, qSDT2-1 and qSDT12-2, which were located on chromosome 2 and 12 within the two introgressed segments derived from the common wild rice, respectively. Physiological characterization, including measurement of water loss, osmotic potential, electrolytical leakage, MDA content, soluble sugars content and the leaf temperature, revealed that IL23 showed the characteristics associated with drought tolerance. Identification and characterization of IL23 would provide a useful basis for isolation of novel genes associated with drought tolerance and for molecular breeding of drought tolerant rice. Furthermore, the results in this study indicated that construction of introgression lines from common wild rice should be an appropriate approach to obtain favorable genetic materials.

China↗

PubMed2006

Dynamic and transient remodeling of the macrophage IL-10 promoter during transcription.

To gain insight into the molecular mechanism(s) whereby macrophages produce large amounts of IL-10, we analyzed IL-10 gene expression and temporally correlated it with modifications to chromatin associated with the IL-10 promoter. In resting cells, which make essentially no cytokines, the IL-10 promoter is associated with histones containing little or no detectable modifications. Macrophages stimulated in the presence of immune complexes begin to produce high levels of IL-10 pre-mRNA transcripts within minutes of stimulation. Coincident with this transcription was a rapid and dynamic phosphorylation of histone H3 at specific sites in the IL-10 promoter. Histone phosphorylation was closely followed by the binding of transcription factors to the IL-10 promoter. Blocking the activation of ERK prevented histone phosphorylation and transcription factor binding to the IL-10 promoter. In contrast to histone phosphorylation, the peak of histone acetylation at this promoter did not occur until after transcription had peaked. Inhibition of histone deactylase did not alter IL-10 gene expression, suggesting that phosphorylation but not acetylation was the proximal event responsible for IL-10 transcription. Our findings reveal a rapid and well-orchestrated series of events in which ERK activation causes a rapid and transient phosphorylation of histone H3 at specific regions of the IL-10 promoter, resulting in a transient exposure of the IL-10 promoter to the transcription factors that bind there. This exposure is essential for the efficient induction of IL-10 gene expression in macrophages. To our knowledge, this represents a unique way in which the expression of a cytokine gene is regulated in macrophages.

Acetylation↗

PubMed2006

NF-kappaB1 (p50) homodimers differentially regulate pro- and anti-inflammatory cytokines in macrophages.

NF-kappaB/Rel is a family of transcription factors whose activation has long been linked to the production of inflammatory cytokines. Here, we studied NF-kappaB signaling in the regulation of the anti-inflammatory cytokine, interleukin-10 (IL-10). We identified a role for a single NF-kappaB family member, NF-kappaB1 (p50), in promoting the transcription of IL-10. The NF-kappaB ciselement on IL-10 proximal promoter was located to -55/-46, where p50 can homodimerize and form a complex with the transcriptional co-activator CREB-binding protein to activate transcription. The other Rel family members appear to play a negligible role in IL-10 transcription. Mice lacking p50 were more susceptible to lethal endotoxemia, and macrophages taken from p50-/- mice exhibit skewed cytokine responses to lipopolysaccharide, characterized by decreased IL-10 and increased tumor necrosis factor and IL-12. Taken together, our studies demonstrate that NF-kappaB1 (p50) homodimers can be transcriptional activators of IL-10. The reciprocal regulation of pro- and anti-inflammatory cytokine production by NF-kappaB1 (p50) may provide potential new ways to manipulate the innate immune response.

Animals↗

PubMed2006

First identification of benzo[ghi]naphtho[8,1,2-bcd]perylene as a product of fuel pyrolysis, using high-performance liquid chromatography with diode-array ultraviolet-visible absorbance detection and mass spectrometry.

We present HPLC/UV/MS evidence to support the identification of benzo[ghi]naphtho[8,1,2-bcd]perylene as a product of supercritical toluene pyrolysis. Mass spectral data confirm that compound I-eluting in between co-eluting benzo[a]coronene/phenanthro[5,4,3,2-efghi]perylene and benzo[pqr]naphtho[8,1,2-bcd]perylene, all three of which have been unequivocally identified as C(28)H(14) products of toluene pyrolysis-is also a C(28)H(14) product component. The UV spectrum of compound I is presented, and indicates that it is a benzenoid polycyclic aromatic hydrocarbon (PAH). Five of the eight benzenoid C(28)H(14) PAH isomers have published UV spectra, and characteristics of the remaining three are deduced from annelation theory. Only one of these compounds, benzo[ghi]naphtho[8,1,2-bcd]perylene, is predicted to have a UV spectrum with characteristics that we find in the spectrum of compound I. In addition, benzo[ghi]naphtho[8,1,2-bcd]perylene is the only benzenoid C(28)H(14) isomer whose length-to-breadth ratio is consistent with the HPLC retention time of compound I. The reaction mechanism through which benzo[ghi]naphtho[8,1,2-bcd]perylene is formed in this environment is shown, and is consistent with reaction pathways of other large PAH found in this product mixture.

Aza Compounds↗