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Jing Chen

Publications and source records attributed to Jing Chen.

At least 181 records · Page 10Linked to original sources
PubMed2005

Characterization of electrospray ionization mass spectrometry for N-diisopropyloxyphosphoryl dipeptide methyl esters.

A systematic study of the fragmentation pattern of N-diisopropyloxyphosphoryl (DIPP) dipeptide methyl esters in an electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was presented. A combination of accurate mass measurement and tandem mass spectrometry had been used to characterize the major fragment ions observed in the ESI mass spectrum. It was found that the alkali metal ions acted as a fixed charge site and expelled the DIPP group after transferring a proton to the amide nitrogen. For all the N-phosphoryl dipeptide methyl esters, under the activation of a metal ion, the rearrangement product ion at m/z 163 was observed and confirmed to be the sodium adduct of phosphoric acid mono-isopropyl esters (PAIE), via a specific five-membered penta-co-ordinated phosphorus intermediate. However, no rearrangement ion was observed when a beta-amino acid was at the N-terminal. This could be used to develop a novel method for differentiating isomeric compounds when either alpha- or beta-amino acid are at the N-terminus of peptides. From the [M+Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters (DIPP Xaa1 Xaa2 OMe), the peaks corresponding to the [M+Na Xaa1 C3H6]+ were observed and explained. The [M+Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters with Phe located in the C-terminal, such as DIPPValPheOMe, DIPPLeuPheOMe, DIPPIlePheOMe, DIPPAlaPheOMe and DIPPPhePheOMe, had characteristic fragmentation. Two unusual gas-phase intramolecular rearrangement mechanisms were first proposed for this fragmentation. These rearrangements were not observed in dipeptide methyl ester analogs which did not contain the DIPP at the N-terminal, suggesting that this moiety was critical for the rearrangement.

Cations↗
PubMed2005

Increasing expression of heme oxygenase-1 by proteasome inhibition protects astrocytes from heme-mediated oxidative injury.

Hemin is released from hemoglobin after CNS hemorrhage, and may contribute to cell loss in surrounding tissue. Heme oxygenase-1 (HO-1) is induced by these injuries, and may have an effect on cell viability. In a prior study, we reported that increasing HO-1 expression by adenoviral gene transfer prior to hemin exposure attenuated oxidative stress and cell death in astrocytes. However, rapid gene transfer to the CNS may not be feasible. HO-1 expression is controlled by a stress-responsive transcription factor, Nrf2, which is a labile protein that is subject to proteasomal degradation. In this study, we hypothesized that preventing degradation of Nrf2 with a lipid-soluble proteasome inhibitor would increase HO-1 expression and protect astrocytes from hemin. Treatment of cortical astrocyte cultures with 1 microM MG-132 resulted in a rapid increase in Nrf2, to a level that was five-fold that of vehicle-treated cultures by 2 h. This was followed by a three to six-fold increase in HO-1 expression that persisted through the 16 h observation period. Exposure of cultures to 30 microM or 60 microM hemin for 8 h resulted in death, as measured by LDH release, of 39+/-3.0 or 67.5+/-5.9% of astrocytes. Pre-treatment with MG-132 prevented approximately half of this injury. Cytoprotection persisted at 24 h, and was also observed when injury was assessed via the MTT assay. Astrocyte protein oxidation produced by hemin was also significantly attenuated by MG-132 pre-treatment. These results suggest that increasing HO-1 expression with a proteasome inhibitor protects astrocytes from heme-mediated oxidative injury. This pharmacological approach may provide a mechanism for rapidly upregulating HO-1 in astrocytes after CNS hemorrhage.

Animals↗
PubMed2005

Purification and characterization of a thermostable glucoamylase from Chaetomium thermophilum.

Thermostable amylolytic enzymes are currently being investigated to improve industrial processes of starch degradation. A thermostable extracellular glucoamylase (exo-1, 4-alpha-D-glucanohydrolase, E.C.3.2.1.3) from the culture supernatant of a thermophilic fungus Chaetomium thermophilum was purified to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) homogeneity by using ammonium sulfate fraction, DEAE-Sepharose Fast Flow chromatography, and Phenyl-Sepharose Fast Flow chromatography. SDS-PAGE of the purified enzyme showed a single protein band of molecular weight 64 kDa. The glucoamylase exhibited optimum catalytic activity at pH 4.0 and 65 degrees C. It was thermostable at 50 degrees C and 60 degrees C, and retained 50% activity after 60 min at 65 degrees C. The half-life of the enzyme at 70 degrees C was 20 min. N-terminal amino acid sequencing (15 residues) was AVDSYIERETPIAWN. Different metal ions showed different effects on the glucoamylase activity. Ca2+, Mg2+, Na+, and K+ enhanced the enzyme activity, whereas Fe2+, Ag+, and Hg2+ cause obvious inhibition. These properties make it applicable to other biotechnological purposes.

Amino Acid Sequence↗
PubMed2005

Novel leptin receptor mutation in NOD/LtJ mice suppresses type 1 diabetes progression: I. Pathophysiological analysis.

A spontaneous single-base mutation in the leptin receptor of type 1 diabetes-prone NOD/LtJ mice (designated as Lepr(db-5J)) produced a glycine640valine transversion in the extracellular domain. All mutant mice became obese and hyperinsulinemic at weaning, with 70-80% developing early-onset hyperglycemia. However, these obese diabetic mice continued to gain weight without insulin therapy. Spontaneous diabetes remission was observed in all obese females and a subset of obese males. Insulitis was largely limited to islet perimeters, with intraislet insulitis infrequently observed. In 17 obese males (age 39 weeks), we observed phenotypic heterogeneity, including full remission from hyperglycemia (24%), intermediate hyperglycemia with elevated body weight (41%), and severe hyperglycemia and weight loss (35%). The remitting normoglycemic and intermediate hyperglycemic phenotypes were associated with extensive beta-cell hyperplasia. Unlike the extensive intraislet insulitis present in diabetic lean NOD/Lt mice, the severe obese diabetic phenotype was associated with islet atrophy without extensive intraislet insulitis. These results indicated that the manipulation of the leptin/leptin receptor axis may provide a novel means of downregulating autoimmunity in type 1 diabetes and confirmed a role for leptin as a mediator in the development of this disease in NOD mice.

Amino Acid Sequence↗
PubMed2005

Relationship between HbA1c level and peripheral arterial disease.

OBJECTIVE: Homeostatic glucose control may play an important role in the development of peripheral arterial disease among individuals without diabetes. We sought to evaluate the association of HbA(1c) (A1C) with peripheral arterial disease in a representative sample of the U.S. population with and without diabetes. RESEARCH DESIGN AND METHODS: A cross-sectional study was conducted among 4,526 National Health and Nutrition Examination Survey 1999-2002 participants > or = 40 years of age. Peripheral arterial disease was defined as an ankle-brachial index <0.9 (n = 327). RESULTS: Among nondiabetic subjects, the age-standardized prevalence of peripheral arterial disease was 3.1, 4.8, 4.7, and 6.4% for participants with an A1C <5.3, 5.3-5.4, 5.5-5.6, and 5.7-6.0%, respectively (P trend <0.001). The prevalence of peripheral arterial disease was 7.5 and 8.8% for diabetic participants with A1C <7 and > or = 7%, respectively. After multivariable adjustment and compared with nondiabetic participants with A1C <5.3%, the odds ratio (95% CI) of peripheral arterial disease for nondiabetic participants with an A1C of 5.3-5.4, 5.5-5.6, and 5.7-6.0% was 1.41 (0.85-2.32), 1.39 (0.70-2.75), and 1.57 (1.02-2.47), respectively, and it was 2.33 (1.15-4.70) and 2.74 (1.25-6.02) for diabetic participants with A1C <7 and > or = 7%, respectively. CONCLUSIONS: An association exists between higher levels of A1C and peripheral arterial disease, even among patients without diabetes. Individuals with A1C levels > or = 5.3% should be targeted for aggressive risk factor reduction, which may reduce the burden of subclinical cardiovascular disease even among those without diabetes.

Age Factors↗
PubMed2005

[Effect of scalp acupuncture on glucose metabolism in brain of patients with depression].

OBJECTIVE: To observe the effect of scalp acupuncture (SA) on the glucose metabolism in different regions of brain in patients with depression by positron emission computed tomography (PET). METHODS: Twelve depressive patients were treated by scalp acupuncture on middle line of vertex (MS5), middle line of forehead (MS1) and bilateral lateral line 1 of forehead (MS2), once a day for six days per week, and received PET detection on different region of brain before and after 6 weeks acupuncture treatment. Semiquantitative analysis was used to compare the average values of radioactive count gotten from various brain regions before and after treatment, which could reflect the condition of glucose metabolism at the brain region detected. RESULTS: SA could increase the glucose metabolism at bilateral frontal lobes, bilateral parietal lobes, right occipital lobe, right caudate nucleus, right cingulated gyrus and left cerebellum and decrease that at right temporal lobe and bilateral thalamus. CONCLUSION: SA on MS5, MS1 and MS2 in depressive patients could influence the glucose metabolism in various brain regions. It primarily illustrated that the mechanism of SA in treating depression is related with its regulation on cortex-limbic circuitry dysfunction and increase the glucose metabolism in various brain regions.

Adult↗
PubMed2005

[Changes in the expression of apoptotic genes in the intestinal tissue of scalded rats before and after resuscitation].

OBJECTIVE: To explore the dynamic changes in the expression of c-fos, proliferation cell nuclear antigen (PCNA) and Bax in the intestinal tissue of scalded rats before and after resuscitation. METHODS: Wistar rats inflicted with 30% TBSA full thickness scald were employed as the model and randomly divided into four groups with 8 in each group, i.e. 2.0, 2.5, 4.0, 6.0 postscald hour (PSH) groups. Rats in each group received routine fluid infusion at 2 PSH, and were sacrificed at 2, 2.5, 4, 6 PSH, respectively. Then the intestinal tissue of the rats was harvested for the detection of the expression of c-fos, PCNA and Bax. RESULTS: The expression of c-fos, PCNA and Bax at 2.0 PSH group (65.8 +/- 4.2%, 74.5 +/- 2.4%, 26.3 +/- 5.7%, respectively) significantly increased when compared with those in 2.5 PSH group (92.4 +/- 5.7%, 85.6 +/- 4.5%, 67.1 +/- 6.6%, respectively) (P < 0.01). The expression of 3 genes increased dramatically at 2.5 and 4.0 PSH, and reached the peak at 2.5 PSH. There was no obvious difference in the gene expression between 4 PSH and 2 PSH groups. CONCLUSION: The expression of apoptotic genes in the intestinal tissue of scalded rats increased significantly during early resuscitation stage after burn injury.

Animals↗
PubMed2005

[Comparative study on bone marrow megakaryocytes in children with thrombocytopenic purpura, aplastic anemia and myelodysplastic syndrome].

OBJECTIVE: Thrombocytopenic hemorrhage is one of the major appearance in pediatric hemorrhagic diseases, in which, idiopathic thrombocytopenic purpura (ITP) is the most common disease. Thrombocytopenia is the earliest phenomenon or the only one in certain phases of hemorrhagic diseases, such as ITP, aplastic anemia (AA) and myelodysplastic syndrome (MDS). By now, the pathogenesis of thrombocytopenia in different diseases has not been clearly determined. At present, it is very difficult to diagnose these diseases and estimate their prognosis with current clinical data. In this study, morphological characteristics and hematopoiesis function of bone marrow megakaryocyte in pediatric patients with ITP, AA and MDS were observed and the cause and mechanism of different thrombocytopenias were analyzed. METHODS: There were 16 children with ITP, 17 with AA and 16 with MDS in this study. CD41 McAb immunohistochemical technique was used to detect micromegakaryocyte on bone marrow smears. Plasma clot culture and CD41 McAb immunohistochemical technique were used for the MK-colony forming assay. The colony formation rate of colony formation unit-megakaryocyte (CFU-MK) and burst formation unit-megakaryocyte (BFU-MK) were counted. RESULTS: There was no statistical difference on the positive rates of micromegakaryocyte and type I lymphoid small micromegakaryocyte between groups of ITP and control. The number of micromegakaryocyte and the formation rates of CFU-MK in ITP group were significantly higher than those in control group. Among AA patients, the numbers of MK, micromegakaryocyte and the formation rates of CFU-MK, BFU-MK in vitro significantly decreased. There was no significant difference in the positive rate of micromegakaryocyte between groups of MDS and control, but the number of micromegakaryocyte and the positive rate of type I lymphoid micromegakaryocyte were significantly higher than those of control group. There was no statistical difference of the formation rate of CFU-MK between groups of MDS and control. But in 63% childhood patients, the formation rate of CFU-MK decreased, 25% increased,and 13% was normal; BFU-MK formation rate decreased significantly in MDS group. CONCLUSION: Overproliferation of bone MKs may exist in most ITP patients. For obviating the nosogenetic factors, the normal MK releasing platelet could be easily found in the culture system. But the colony formation rate of MK decreased in a few patients with CITP. The abnormality of MK might be one of the reasons for thrombocytopenia in partial patients with ITP. Underproliferation of MKs may exist in AA, but no pathosishemogenesis was found. The dysfunction of early phase MK progenitor and stem cell might be the major reason for AA, but not the abnormality of hematopoietic microenvironment. There may be two kinds of megakaryocyte clones in bone marrow of children with MDS. One may be pathologic and potentially malignant micromegakaryocytes, the other may be the normal megakaryocytic precursors. The increase of pathologic MK resulted in abnormal development and maturation of MK in bone marrow. The change of megakaryopoiesis showed different in ITP, AA or MDS. Using bone marrow smear megakaryocyte counting, small micromegakaryocyte immunohistochemical detecting and the formation rate of bone marrow MK colony assay, the different thrombocytopenia can be diagnosed during the early stage of ITP, AA or MDS.

Adolescent↗
PubMed2005

[Visualization of regenerated sciatic nerve of rat after injury].

There is close relationship between the morphologic changes of peripheral nerve after injury and its function recovery during regeneration. In our experiment, the sciatic nerve of rats was transected and bridge-connected with silicone tube, and the images of serial slices of different time and different injury parts were taken by micro-photograph system. The volume unit model was applied to rendering the three dimensional (3D) structure of degenerative and regenerative sciatic nerve fiber and its affiliated structure after injury. The 3D images showed that node of Ranvier had not formed and its array was turbulent, both the myelin sheath and the axis-cylinder were thinner, and the collagen fibres had proliferated.

Animals↗
PubMed2005

[Experimental study on the relationship between neuropeptide substance P and wound healing in scalded rats].

OBJECTIVE: To explore the relationship between neuropeptide substance P (SP) and wound healing in scalded rats. METHODS: (1) Scalded rats with different degrees of scald injury were employed as the experimental model and were sacrificed at 24 post scald hour (PSH), and on 3, 7 and 14 post scald days (PSD). The SP content in the wound was detected with radioimmunoassay method. (2) The murine granulation tissue fibroblasts (GTF) were cultured with different culture media, and divided into control, SP and Spantide (SP receptor antagonism) groups. The effects of SP and Spantide on the cellular activity and apoptotic rate of murine GTF were assessed in vitro. RESULTS: There was significant difference of the SP content among the superficial (145 +/- 78) ng/g, partial (94 +/- 48 ng/g) and full thickness (53 +/- 27 ng/g) scald wounds at 24 PSH (P < 0.01), while the SP content in partial thickness burn wound on 3 and 7 PSD obviously increased; and that in deep partial thickness burn wound obviously increased on 7 and 14 PSD. But the SP content remained unchanged in full thickness scald wound. (2) SP could promote the activity of GTF and inhibit its apoptosis (The GTF activity in control, SP groups were 0.21 +/- 0.05, 0.36 +/- 0.07, respectively, P < 0.01). Spantide could inhibit the interaction between SP and GTF. CONCLUSION: SP can promote GTF proliferation, and the SP content in wound is closely associated with the depth of the injury and wound healing capacity.

Animals↗
PubMed2005

[Prognostic value of both detection of lymphoblasts in the period of early treatment and minimal residual disease in childhood acute lymphoblastic leukemia].

OBJECTIVE: To assess the prognostic value of both morphological persistent disease on day 19, on complete remission (CR) and minimal residual disease (MRD) in the bone marrow (BM) after multiagent remission induction therapy. METHODS: From January 1998 to May 2003, 193 patients with newly diagnosed ALL were enrolled on protocol of ALL-XH-99. BM blast counts on day 19 and on CR after induction therapy were examined. BM MRD at the end of induction therapy was detected by MP-FCM. RESULTS: (1) The probability of 5-year event-free survival (pEFS) was significantly worse for patients with > or = 0.050 BM lymphoblasts on day 19 than that with < 0.050 BM lymphoblasts [(42.59 +/- 14.28)% vs (74.24 +/- 6.67)%, P < 0.001]. (2) The 5-year pEFS was significantly worse for patients with a low percentage of lymphoblasts (< 0.050) in BM on CR as compared to those with no morphological persistent lymphoblasts [(63.47 +/- 9.23)% vs (76.41 +/- 6.09)%, P < 0.05]. (3) No significant difference was found in BM lymphoblasts between patients with MRD (> or = 10(-4) of nucleated bone marrow cells) and those without MRD (< 10(-4)) at the end of induction therapy (P > 0.05). The 22-month pEFS was significantly worse for patients with MRD as compared with those without MRD on CR [(23.81 +/- 20.26)% vs (94.44 +/- 5.40)%, P = 0.001]. CONCLUSIONS: BM lymphoblast > or = 0.050 on day 19 after induction therapy is an independent prognostic factor for childhood ALL; low percentage of lymphoblasts and minimal residual disease in BM on remission also do it. Patients with > or = 0.050 lymphoblast in BM on day 19 or with MRD > or = 10(-4) at the end of induction therapy should receive altered and more intensive chemotherapy.

Adolescent↗
PubMed2005

[Influences of surfactant on the transport of PAHs in artificially contaminated soil columns].

The effect of anionic surfactant LAS on leaching of PAHs from artificially contaminated soil was studied. The interaction of these processes were studied in a two-layer column experiment with a base layer of uncontaminated soil(9cm) and a top layer of artificially contaminated soil(1cm). Results show that 5 critical micelle concentration (CMC) LAS enhanced the transport of PAHs. The breakthrough curves of low ring PAHs followed the normal distribution and the relative leaching ratios of 4 or more rings PAHs were low, and not more than 10%. The transport of PAHs was retarded compared with LAS, and the high ring PAHs were retarded more significantly. Linear correlation was observed between the relative leachability of the individual PAHs and the octanol/water coefficient of PAHs.

Polycyclic Aromatic Hydrocarbons↗
PubMed2005

[Expression and bioactive characterization of bacteriophage lysin gene of Bacillus anthracis in Escherichia coli].

The lysin gene of Bacillus anthracis-diagnosing bacteriophage, obtained by PCR amplification,was cloned into the Escherichia coli exepression vector pET22b which has been cleaved by EcoR I and Nde I. The recombinant vector pET22b-gamma lysin was verified to be correctly constructed by PCR, sequencing and enzyme digestion, and highly expressed in E. coli BL21 (DE3), which accounted for about 40 percent of total protein in E. coli BL21 (DE3), while in the 5L fermentor the expression level reached 15g/L. After expression, disruption and purification with three-step chromatography, Streamline SP, SP HP and Sephacryl S-100, the recombinant gamma lysin was finally obtained with purity of higher than 95 percent as determined by gel scan. The final yield following SP HP was 19.1 percent, with a greater-than-350-fold increase in specific activity. The pure enzyme has been shown active to Bacillus anthracis, and not to E. coli, Bacillus subtilis and Bacillus cereus. Its specific activity was about 1400 u/mg.

Bacillus anthracis↗
PubMed2005

[Effects of L-arginine on the microcirculation of rat island skin flaps after ischemia- reperfusion].

OBJECTIVE: To investigate the effects of L-arginine on the microcirculation and survival of rat island skin flaps after ischemia-reperfusion. METHOD: A right lower abdominal island flap was created in SD rats and the microcirculatory blood flow in these flaps measured with laser Doppler velocimetry following L-arginine injection via the contralateral femoral artery. Both NO and malondialdehyde (MDA) levels in the flaps were assayed and the survival of the flaps replanted in situ was evaluated 1 week later. RESULTS: L-arginine treatment caused increase in the microcirculatory blood flow of the flaps and elevation of NO while and decrease of MDA levels. The survival rate of the flaps with L-arginine treatment was significantly higher than the flaps from saline-treated and normal rats. CONCLUSION: L-arginine can improve the survival of island flap through increasing the microcirculatory blood flow and lessening ischemia-reperfusion injury of the flaps.

Animals↗
PubMed2005

[The significance of Th1/Th2 function imbalance in patients with post-infarction cardiac insufficiency].

OBJECTIVE: To study the significance of Th1/Th2 function imbalance in patients with post-infarction cardiac insufficiency. METHODS: Forty-three MI (myocardial infarction) patients were divided into 2 groups one month after the onset according to the New York Heart Association (NYHA) classification system: group MI 1 (I, II) 25 patients and group MI 2 (III, IV) 18 patients. At the same time, the heart function was evaluated by two-dimensional echocardiography. Peripheral blood mononuclear cells (PBMCs) were collected from these patients. Cytokine-producing CD4 + T cells were quantified by 3-color flow cytometry after being stimulated with phorbol myristate acetate (PMA) and ionomycin. After being stimulated with PHA, the levels of IFN-gamma and IL-4 in culture supernatants were measured by ELISA. RESULTS: The frequencies of IFN-gamma-producing T cells were found to be significantly higher in group MI 2 (16.8%) than that in group MI 1 (13.1%). There was no significant difference on the frequencies of IL-4-producing peripheral T cells between the two groups. The IFN-gamma level and the ratios of IFN-gamma/IL-4 in group MI 2 were significantly higher than those in group MI 1, while there was no significant difference in IL-4 levels between the two groups. CONCLUSIONS: The Th-cell function was associated with heart function in post MI patients. The up-regulation of Th1 cell function was consistent with poor heart function, suggesting that Th1/Th2 cell function imbalance may participate in ventricular remodelling after MI.

Aged↗
PubMed2005

[Failure of treatment and protocol compliance in patients with acute lymphoblastic leukemia].

OBJECTIVE: To analyze the main reason of failure in treatment and compliance to protocol in children with acute lymphoblastic leukemia (ALL) at a single institute which is located at the most developed city of China. METHODS: All the ALL patients who were diagnosed at the hospital from October 1998 to June 2003 were analyzed. The data were extracted from the department's tumor registry database. Failure in protocol compliance and treatment was analyzed within different risk groups, patients' resident area, and time period. The patients who had not received any therapy after ALL diagnosis were accounted as early protocol compliance failure, those who received therapy for less than 15 days were regarded as interim failure in protocol compliance, and those who gave up therapy or were lost in follow-up after 15 days with stable disease or complete remission (CR) were accounted as late compliance failure. RESULTS: Totally 224 patients were diagnosed to have ALL, of them 38 patients went home without receiving any therapy, i.e., the rate of early protocol compliance failure was 17.1%. Of the remaining 186 patients, 22 (10.5%) belonged to interim protocol compliance failure, and 6 cases discontinued the therapy after 15 days treatment, who were classified into late compliance failure. Six cases (10.5%) were regarded as protocol compliance failure among 57 Shanghainese, and so were 22 cases (17.1%) out of 129 non-Shanghainese. There was no significant difference between the two groups (chi(2) = 1.332, P > 0.05). Up to a median 40 months follow-up showed that in 52 patients (31.7%) the treatment failed, of which 37 cases (22.6%) died of incomplete response and relapse, and 15 cases (9.5%) died of therapy complication. Among different risk groups, 24 cases (47.1%) came from high risk group, 18 (34.0%) from medium risk group, and 5 (9.4%) from low risk group. Very significant difference was found among the different risk group (chi(2) = 21.463, P < 0.01). Treatment failure was 28.6% (32/112) in non-Shanghainese and 38.5% (20/52) in Shanghainese. Total failure in protocol compliance and treatment was 42.9% (32 + 22/129) in non-Shanghainese and 45.6% (20 + 6/57) in Shanghainese. The difference of treatment failure was not significant different between the two groups (chi(2) = 1.354, P > 0.05). CONCLUSION: Protocol compliance failure is the reason as important as the treatment failure for childhood ALL management failure. Either failure should not be neglected. Death from complications was relatively high which needs more attention, especially during induction period. Unusually high death rate occurred in high and medium risk group patients. The grouping criteria may need modification.

Adolescent↗
PubMed2005

[Subcellular localization and tissues expression profile of hGPCRc: an orphan G protein-coupled receptor].

As a member of orphan G protein-coupled receptors (oGPCRs), hGPCRc was cloned from human colon tissue and analyzed by bioinformatic softwares. It was showed that the corresponding amino acids of hGPCRc formed seven-transmembrane domains as the key characteristic of GPCRs. Then, the recombinant GFP-hGPCRc was constructed by fussing hGPCRc into pEGFP-N1 carrying green fluorescent protein (GFP) gene, and CHO-K1 cells were subsequently transfected with the GFP-hGPCRc or pEGFP-N1. The green fluorescence protein expression in the two different transfected cells was observed under the laser scanning confocal microscopy (LSCM). It was showed that green fluorescence protein was distributed in the whole bodies of the cells transfected with pEGFP-N1, but mainly distributed on the plasma membrane and cytoplasm membrane transfected with GFP-hGPCRc. Thus, the localization on the membrane of hGPCRc was accorded with the predication by bioinformatic analysis. The expression analysis of hGPCRc by RT-PCR indicated that hGPCRc was abundantly expressed in heart, kidney, cerebel and colon etc., but absent in liver, cerebra, small intestine and muscle etc. The expressing profile of hGPCRc could provide some useful clues to understanding its effects on embryonic development and physiological functions.

Amino Acid Sequence↗