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Guang Chen

Publications and source records attributed to Guang Chen.

At least 19 recordsLinked to original sources
PubMed2025

Harnessing fern stress adaptations: From evolution and ecophysiology to molecular biology.

Ferns are the second most diverse vascular plant lineage after angiosperms and have been a key ecological component of Earth's biodiversity for more than 380 million years. Importantly, ferns are sister to seed plants, providing a critical outgroup for understanding the evolution of seed plant features. Ferns are remarkably resilient to abiotic and biotic stresses due to a long evolutionary history with adaptations to diverse habitats, stresses, and herbivores. As a result, ferns produce a multitude of secondary metabolites with unique bioactivities; these chemicals are potentially linked to the adaptation of ferns to herbivory, various abiotic and biotic stresses, and changing environments. Assembled reference genomes and the identification of key metabolic compounds of multiple ferns have already made significant contributions to human health and well-being. Here, we review the recent scientific advances in fern research, including evolution, stress resistance, metabolites and medicinal utilization, and comparative multi-omics applications. We propose that integrated investigations involving ecological, physiological, and molecular techniques will facilitate the future research translation of fern resources in diverse areas including soil remediation, biopesticides, and medicine. Advances in our understanding of fern molecular biology will provide new insights into the evolution of land plants and promote the utilization of ferns for heightened environmental restoration, crop protection and human health.

Ferns↗
PubMed2007

Clustering of genes into regulons using integrated modeling-COGRIM.

We present a Bayesian hierarchical model and Gibbs Sampling implementation that integrates gene expression, ChIP binding, and transcription factor motif data in a principled and robust fashion. COGRIM was applied to both unicellular and mammalian organisms under different scenarios of available data. In these applications, we demonstrate the ability to predict gene-transcription factor interactions with reduced numbers of false-positive findings and to make predictions beyond what is obtained when single types of data are considered.

CCAAT-Enhancer-Binding Protein-beta↗
PubMed2006

Neurotrophic signaling cascades in the pathophysiology and treatment of bipolar disorder.

Increasing evidence suggests that bipolar disorder (BPD) is associated with regional brain volumetric reductions, accompanied by cellular atrophy and/or loss. Considerable data suggest that the protypical drugs for BPD--lithium and valproate--when administered in therapeutically relevant paradigms regulate neurotrophic signaling cascades. Notably, brain-derived neurotrophic factor, the extracellular signal-regulated kinase pathway, the glycogen synthase kinase-3-mediated pathway and Bcl-2 are major targets for mood stabilizers. Further data suggest that agents which directly target neurotrophic signaling cascades may have considerable utility for the treatment of this devastating illness.

Animals↗
PubMed2006

Chromium(III) complexes of D-glucosaminic acid and their effect on decreasing blood sugar in vivo.

Two chromium(III) complexes of glucosaminic acid were synthesized by neutralization and exchange reaction. The formation of 1 : 1 and 2 : 3 (Cr : glucosaminate) complexes was confirmed by elemental analyses and spectroscopic studies. The effect of the complexes on decreasing blood sugar was investigated on type-2 diabetes model rats induced by tetraoxypyrimidine. The results indicated that the effect on decreasing blood sugar was comparable to that of picolinate chromium complex (Cr(pic)(3)) currently used world wide.

Alloxan↗
PubMed2006

Genetic diversity of source germplasm of Upland cotton in China as determined by SSR marker analysis.

The genetic diversity of 43 sources of Upland cotton germplasm with different parental origins, breeding periods, and ecological growing areas in China were studied on the basis of simple sequence repeat (SSR) markers. A total of 130 gene alleles with 80% polymorphism were detected from 36 SSR primers. The number of alleles per primer ranged from two to eight with an average of 3.6. The polymorphism information content (PIC) range was 0.278-0.865, with an average of 0.62. The average genotype diversity index (H') was 1.102, the highest was 2.039 and the lowest was 0.451. The average coefficient of the genetic similarity of SSR markers among source germplasm was 0.610, ranging from 0.409 to 0.865. These indicated that the genetic diversity at the genomic level of the selected source germplasm was rich, and was representative of the diversity of the germplasms, in general. The diversity at the genome level of the base germplasm from the second and third breeding periods was decreased compared to that of the first period, indicating that the cotton genetic background in China became narrow gradually. The diversity of SSR markers among the base germplasm from early maturity cotton growing areas in the north was higher than those from the Huanghe and Yangtze growing areas. The molecular marker genetic similarity index of the domestic varieties was higher than that in the introduced varieties, which indicates that the genetic diversity in domestic cultivars was lower than that in the introduced varieties. This study gives an overview of the genetic diversity of the cotton germplasm base in China, and provides a guide for breeders to develop new cultivars efficiently.

China↗
PubMed2006

The extracellular signal-regulated kinase pathway: an emerging promising target for mood stabilizers.

PURPOSE OF REVIEW: There exists a growing appreciation that, though not classical neurodegenerative disorders, severe mood disorders are associated with regional impairments of structural plasticity and cellular resilience. Exciting recent data suggest that synaptic plasticity probably is involved in mechanisms of actions of mood stabilizers and antidepressants. Notably, the extracellular signal-regulated kinase pathway is a critical 'plasticity pathway' in the brain. The present review summarizes neurobiological, pharmacological, and behavioral data on the role of the extracellular signal-regulated kinase pathway in regulating some of the symptoms of bipolar disorder and as a therapeutically relevant target for mood stabilizers. RECENT FINDINGS: The extracellular signal-regulated kinase pathway is known to mediate neurotrophic actions and synaptic plasticity. Treatment with lithium and valproate activates the extracellular signal-regulated kinase pathway in cultured cells and in prefrontal cortex and hippocampus. In addition, lithium or valproate treatment promotes neurogenesis, neurite growth, and cell survival. The extracellular signal-regulated kinase pathway is also targeted by antipsychotics. Modulation of the central nervous system extracellular signal-regulated kinase pathway induces animal behavioral alterations reminiscent of manic symptoms; these complex behaviors probably depend on the effects of extracellular signal-regulated kinase on discrete brain regions and the presence of other interacting molecules. SUMMARY: The extracellular signal-regulated kinase pathway may represent a novel target for the development of improved therapeutics for bipolar disorder.

Animals↗
PubMed2006

[Target lethal effect of recombinant soluble Fas coupled with protein kinase C inhibitor on colorectal carcinoma cells].

OBJECTIVE: To study the target killing effect of soluble Fas(sFas) coupled with protein kinase C(PKC) inhibitor on colorectal carcinoma cells. METHODS: The extracellular region of Fas protein was cloned and amplified by RT-PCR, and the expressing vector pGEX-4T-1-sFas was constructed. The sFas protein was purified by GST fusion protein purification system and coupled with Calphostin C(one kind of PKC inhibitor). The killing effect of soluble Fas coupled with PKC inhibitor on FasL-positive colorectal carcinoma cells was detected. RESULTS: After amplifying and cloning, the extracellular region of Fas protein, a 571 bp fragment, was proved by limited enzyme cutting and DNA sequencing. The expressed and purified protein was identified by Western Blot after transformed into E. coli BL21. The coupled sFas-Calphostin C showed suppressant activity on PKC kinase by the PKC kinase activity assay kit. The growth suppression rate of FasL-positive colorectal carcinoma HR-8348 cells treated with sFas-Calphostin C was significantly higher than that of FasL-negative cells, but the killing effect of sFas-Calphostin C on normal human monocyte was not obvious. Compared with 5-Fu alone, the growth suppression rate of FasL-positive colorectal carcinoma HR-8348 cells was significantly raised by sFas-Calphostin C combined with 5-Fu. CONCLUSION: The recombinant of soluble Fas and PKC inhibitor shows target killing effect on colorectal carcinoma cells.

Colorectal Neoplasms↗
PubMed2005

Defining the mammalian CArGome.

Serum response factor (SRF) binds a 1216-fold degenerate cis element known as the CArG box. CArG boxes are found primarily in muscle- and growth-factor-associated genes although the full spectrum of functional CArG elements in the genome (the CArGome) has yet to be defined. Here we describe a genome-wide screen to further define the functional mammalian CArGome. A computational approach involving comparative genomic analyses of human and mouse orthologous genes uncovered >100 hypothetical SRF-dependent genes, including 10 previously identified SRF targets, harboring a conserved CArG element within 4000 bp of the annotated transcription start site (TSS). We PCR-cloned 89 hypothetical SRF targets and subjected each of them to at least two of several validations including luciferase reporter, gel shift, chromatin immunoprecipitation, and mRNA expression following RNAi knockdown of SRF; 60/89 (67%) of the targets were validated. Interestingly, 26 of the validated SRF target genes encode for cytoskeletal/contractile or adhesion proteins. RNAi knockdown of SRF diminishes expression of several SRF-dependent cytoskeletal genes and elicits an attending perturbation in the cytoarchitecture of both human and rodent cells. These data illustrate the power of integrating existing algorithms to interrogate the genome in a relatively unbiased fashion for cis-regulatory element discovery. In this manner, we have further expanded the mammalian CArGome with the discovery of an array of cyto-contractile genes that coordinate normal cytoskeletal homeostasis. We suggest one function of SRF is that of an ancient master regulator of the actin cytoskeleton.

Animals↗
PubMed2005

[Analysis of 618 cases of radical resection of rectal carcinoma].

OBJECTIVE: To investigate and analyse curative effects of Miles operation and anal sphincter preserving operation for rectal carcinoma in 20 years. METHODS: From 1984 to 2004, 618 cases of rectal carcinoma that underwent radical resection including Miles operation and anal sphincter preserving procedures were analysed retrospectively each 10 years, earlier 10 years from 1984 to 1994, and later 10 years from 1994 to 2004. RESULTS: Among the 618 cases, 492 (79.6%) were followed up. The median of the follow-up time was 5.4 years. In the earlier 10 years, local recurrence rate of post operation was 6.9% (14/201), for Miles operation and anal sphincter preserving procedures the local recurrence rate was 6.7% and 7.1% respectively. In the later 10 years, the local recurrence rate was 5.1% (15/291), 4.8% for Miles operation, 5.2% for anal sphincter preserving procedures. With the procedure of canular anastomosis of colon and rectal mucosa, the local recurrence rate was 4.9%. Overall five-year survival rate was 64.7% (130/201) in the earlier 10 years, 66.3% (59/89) for Miles operation, 63.4% (71/112) for anal sphincter preserving procedures. In the later 10 years, the five-year survival rate was 68.0% (198/291) in all, for Miles operation 66.3% (55/83), for anal sphincter preserving procedures 68.7% (143/208). With the procedure of canular anastomosis of colon and rectal mucosa, the five-year survival rate was 71.3% (62/87). CONCLUSIONS: The operation for rectal cancer should be chosen individually according to locus, biological character, and clinical stages. Anal sphincter preserving procedures are performed increasingly, and they provide the same five-year survival rate as Miles operation does, and the patient's quality of life can be improved obviously.

Adult↗
PubMed2005

The anti-apoptotic, glucocorticoid receptor cochaperone protein BAG-1 is a long-term target for the actions of mood stabilizers.

Increasing data suggest that impairments of cellular plasticity/resilience underlie the pathophysiology of bipolar disorder. A series of microarray studies with validating criteria have recently revealed a common, novel target for the long-term actions of the structurally highly dissimilar mood stabilizers lithium and valproate: BAG-1 [BCL-2 (B-cell CLL/lymphoma 2)-associated athanogene]. Because BAG-1 attenuates glucocorticoid receptor (GR) nuclear translocation, activates ERK (extracellular signal-regulated kinase) MAP (mitogen-activated protein) kinases, and potentiates anti-apoptotic functions of BCL-2, extensive additional studies were undertaken. Chronic administration of both agents at therapeutic doses increased the expression of BAG-1 in rat hippocampus. Furthermore, these findings were validated at the protein level, and the effects were seen in a time frame consistent with therapeutic effects and were specific for mood stabilizers. Functional studies showed that either lithium or valproate, at therapeutically relevant levels, inhibited dexamethasone-induced GR nuclear translocation and inhibited GR transcriptional activity. Furthermore, small interfering RNA studies showed that these inhibitory effects on GR activity were mediated, at least in part, through BAG-1. The observation that BAG-1 inhibits glucocorticoid activation suggests that mood stabilizers may counteract the deleterious effects of hypercortisolemia seen in bipolar disorder by upregulating BAG-1. Additionally, these studies suggest that regulation of GR-mediated plasticity may play a role in the treatment of bipolar disorder and raise the possibility that agents affecting BAG-1 more directly may represent novel therapies for this devastating illness.

Alkaline Phosphatase↗
PubMed2005

Kakispyrol, a new biphenyl derivative from the leaves of Diospyros kaki.

A new biphenyl derivative, 4',5-dimethoxy-3-beta-D-glucopyranosyloxy-4-hydroxy-biphenyl, named kakispyrol (1), has been isolated from the leaves of Diospyros kaki, together with three known compounds, vitexin (2), 2'-O-rhamnosyl vitexin (3) and isorhamnetin-3-O-beta-D-glucopyranoside (4). The structure of compound 1 has been determined on the basis of spectroscopic evidence.

Biphenyl Compounds↗
PubMed2005

Biocompatibility of Poly(epsilon-caprolactone) scaffold modified by chitosan--the fibroblasts proliferation in vitro.

In this study, the surface of poly(epsilon-caprolactone) (PCL) scaffold was modified by chitosan (CS) in order to enhance its cell affinity and biocompatibility. It is demonstrated by scanning electronic microscopy (SEM) that when 0.5-2.0 wt% chitosan solutions are used to modify the PCL scaffold, the amount of adhesion of the fibroblasts on the chitosan-modified PCL scaffolds dramatically increase when compared to the control after 7 days cell culture. The results indicate that the chitosan-modified PCL scaffolds are more favorable for cell proliferation by improving the scaffold biocompatibility. The improvement may be helpful for the extensive applications of PCL scaffold in heart valve and blood vessel tissue engineering.

Cell Adhesion↗
PubMed2005

Determination of theophylline concentration in serum by chemiluminescent immunoassay.

OBJECTIVE: This study aimed to establish chemiluminescent immunoassay (CLIA) for quantitative determination of theophylline levels in human serum. METHODS: To measure the concentration of theophylline (n=122) and evaluate the assay. RESULTS: The linear range of the CLIA method was 0.51-40 mg/L (Y=1.02X+0.44, r=0.995). The intra and inter CV (coefficient variance) of CLIA were 3.20% and 3.57%, respectively. The average recovery rate was 102.3%. This method was free from interference by brilirubin (<200 micromol/L), hemoglobin (<10 g/L), and triglycerides (<15 mmol/L). CONCLUSION: This method is simple, convenient and precise for clinical pharmacokinetics study of theophylline.

Blood Chemical Analysis↗
PubMed2004

Mood stabilizer valproate promotes ERK pathway-dependent cortical neuronal growth and neurogenesis.

Manic-depressive illness has been conceptualized as a neurochemical illness. However, brain imaging and postmortem studies reveal gray-matter reductions, as well as neuronal and glial atrophy and loss in discrete brain regions of manic-depressive patients. The roles of such cerebral morphological deficits in the neuropathophysiology and therapeutic mechanisms of manic-depressive illness are unknown. Valproate (2-propylpentanoate) is a commonly used mood stabilizer. The ERK (extracellular signal-regulated kinase) pathway is used by neurotrophic factors to regulate neurogenesis, neurite outgrowth, and neuronal survival. We found that chronic treatment of rats with valproate increased levels of activated phospho-ERK44/42 in neurons of the anterior cingulate, a region in which we found valproate-induced increases in expression of an ERK pathway-regulated gene, bcl-2. Valproate time and concentration dependently increased activated phospho-ERK44/42 and phospho-RSK1 (ribosomal S6 kinase 1) levels in cultured cortical cells. These increases were attenuated by Raf and MEK (mitogen-activated protein kinase/ERK kinase) inhibitors. Although valproate affects the functions of GSK-3 (glycogen synthase kinase-3) and histone deacetylase (HDAC), its effects on the ERK pathway were not fully mimicked by selective inhibitors of GSK-3 or HDAC. Similar to neurotrophic factors, valproate enhanced ERK pathway-dependent cortical neuronal growth. Valproate also promoted neural stem cell proliferation-maturation (neurogenesis), demonstrated by bromodeoxyuridine (BrdU) incorporation and double staining of BrdU with nestin, Tuj1, or the neuronal nuclei marker NeuN (neuronal-specific nuclear protein). Chronic treatment with valproate enhanced neurogenesis in the dentate gyrus of the hippocampus. Together, these data demonstrate that valproate activates the ERK pathway and induces ERK pathway-mediated neurotrophic actions. This cascade of events provides a potential mechanism whereby mood stabilizers alleviate cerebral morphometric deficits associated with manic-depressive illness.

Animals↗
PubMed2004

[Studies on the relationship between the level of cytokine and liver function in patients with clonorchiasis sinensis].

OBJECTIVE: To explore the relationship between cytokine level and liver function among patients infected with Clonorchis sinensis. METHODS: 47 patients were divided into three groups according to the degree of Child-Pugh liver function grade: 20 in group A (3-4 scores), 15 in group B (5-6 scores) and 12 in group C (7-9 scores). Interleukin 2 (IL-2), soluble IL-2 receptor (sIL-2R), interleukin 8 (IL-8) and tumor necrosis factor (TNF-alpha) were examined by radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA). Automatic biochemical analyzer was employed for the determination of serum level of total bilirubin (TBL), albumin (ALB) and alanine aminotransferase (ALT). Data were analyzed with SAS statistic software. RESULTS: Serum levels of sIL-2R, IL-8 and TNF-alpha from patients were significantly higher than those obtained from healthy people (P<0.05, P<0.05, P<0.01), whereas the IL-2 level was significantly lower than the former (P<0.01). With the affected degree of the liver, serum levels of sIL-2R, IL-8 and TNF-alpha increased, in contrast to the decrease of IL-2 level. The differences were significant between groups A and C (P<0.05). The level of sIL-2R and TNF-alpha directly correlated with that of TBL (r=0.331 P<0.05, r=0.518 P<0.01) and ALT (r=0.475 P<0.01, r=0.285 P<0.05) respectively, but inversely correlated with the level of ALB (r=-0.319 P<0.05, r=-0.665 P<0.01). CONCLUSION: The infection of Clonorchis sinensis results in the reduction of cellular immune function of the patients. Certain relationship exists between serum cytokine level and liver function. Two cytokines, sIL-2R and TNF-alpha, are involved in the process of pathology.

Adult↗
PubMed2004

Silk fibroin modified porous poly(epsilon-caprolactone) scaffold for human fibroblast culture in vitro.

In order to develop scaffolds with improved biocompatibility for cell culture, hybrid scaffolds were fabricated by modifying poly(epsilon-caprolactone) (PCL) with silk fibroin (SF) in a porous structure. Scanning electronic microscopy revealed that the morphology of the PCL-SF hybrid scaffold was affected by the concentration of the SF solution. Availability of SF on the surface and the conformational transition induced by methanol treatment were proved by attenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR), and wettability of the hybrid scaffold was greatly improved. To evaluate scaffold biocompatibility, human fibroblasts were cultured on the hybrid scaffold with the unmodified PCL scaffold as control. An MTT assay indicated that although fewer cells were initially held on the hybrid scaffold after one day of culture, comparable cell numbers were achieved after four days and significantly more cells proliferated on the hybrid after seven days. The cell morphology also indicated that the PCL-SF hybrid scaffold was favorable for cell culture. This study suggests that surface modification with SF would be an effective way to improve the biocompatibility of PCL, facilitating its application in practical tissue engineering.

Cell Adhesion↗