Biomedical subjects

Qiong Cao

Publications and source records attributed to Qiong Cao.

17 recordsLinked to original sources

PubMed2007

2', 3'-Cyclic nucleotide 3'-phosphodiesterase cells derived from transplanted marrow stromal cells and host tissue contribute to perineurial compartment formation in injured rat spinal cord.

Transdifferentiation of transplanted marrow stromal cells (MSCs) and reactive changes of glial cells in a completely transected rat spinal cord were examined. Marrow stromal cells exhibited 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) at the plasma membrane and this has allowed their identification after transplantation by immunoelectron microscopy. In the control rats, the lesion site showed activated microglia/neural macrophages and some elongated cells, whose cytoplasm was immunoreactive for CNP. Cells designated as CNP1 and apparently host-derived expressed CXCR4. In experimental rats receiving MSCs transplantation, CNP1 cells were increased noticeably. This was coupled with the occurrence of a different subset of CNP cells whose plasma membrane was CNP-immunoreactive and expressed CXCR4. These cells, designated as CNP2, enclosed both myelinated and unmyelinated neurites thus assuming a spatial configuration resembling that of Schwann cells. A remarkable feature was the extensive ramifications of CNP1 cells with long filopodia processes delineating the CNP2 cells and their associated neurites, forming many perineurial-like compartments. Present results have shown that CNP2 cells considered to be MSCs-derived can transform into cells resembling Schwann cells based on their spatial relation with the regenerating nerve fibers, whereas the CNP1 glial cells participate in formation of perineurial compartments, probably serving as conduits to guide the nerve fiber growth. The chemotactic migration of CNP cells either derived from host tissue or MSCs bearing CXCR4 may be attracted by stromal derived factor-1alpha (SDF-1alpha) produced locally. The coordinated cellular interaction between transplanted MSCs and local glial cells may promote the growth of nerve fibers through the lesion site.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

PubMed2006

Transient expression of endothelins in the amoeboid microglial cells in the developing rat brain.

Amoeboid microglial cells (AMC) which transiently exist in the corpus callosum in the postnatal rat brain expressed endothelins (ETs), specifically endothelin-1 (ET-1) and ET3 as revealed by real time RT-PCR. ET immunoreactive AMC occurred in large numbers at birth, but were progressively reduced with age and were undetected in 14 days. In rats subjected to hypoxia exposure, ET immunoexpression in AMC was reduced but the incidence of apoptotic cells was not increased when compared with the control suggesting that this was due to its downregulation that may help regulate the constriction of blood vessels bearing ET-A receptor. AMC were endowed ET-B receptor indicating that ET released by the cells may also act via an autocrine manner. In microglia activated by lipopolysaccharide (LPS), ET-1 mNA expression coupled with that of monocyte chemoattractant protein (MCP-1) and stromal derived factor-1 (SDF-1) was markedly increased; ET-3 mRNA, however, remained unaffected. AMC exposed to oxygen glucose deprivation (OGD) in vitro resulted in increase in both ET-1 and ET-3 mRNA expression. It is suggested that the downregulated ETs expression in vivo of AMC subjected to hypoxia as opposed to its upregulated expression in vitro may be due to the complexity of the brain tissue. Furthermore, the differential ET-1 and ET-3 mRNA expression in LPS and OGD treatments may be due to different signaling pathways independently regulating the two isoforms. The present novel finding has added microglia as a new cellular source of ET that may take part in multiple functions including regulating vascular constriction and chemokines release.

Animals↗

PubMed2006

Brain-specific BNIP-2-homology protein Caytaxin relocalises glutaminase to neurite terminals and reduces glutamate levels.

Human Cayman ataxia and mouse or rat dystonia are linked to mutations in the genes ATCAY (Atcay) that encode BNIP-H or Caytaxin, a brain-specific member of the BNIP-2 family. To explore its possible role(s) in neuronal function, we used protein precipitation and matrix-assisted laser desorption/ionisation mass spectrometry and identified kidney-type glutaminase (KGA) as a novel partner of BNIP-H. KGA converts glutamine to glutamate, which could serve as an important source of neurotransmitter. Co-immunoprecipitation with specific BNIP-H antibody confirmed that endogenous BNIP-H and KGA form a physiological complex in the brain, whereas binding studies showed that they interact with each other directly. Immunohistochemistry and in situ hybridisation revealed high BNIP-H expression in hippocampus and cerebellum, broadly overlapping with the expression pattern previously reported for KGA. Significantly, BNIP-H expression was activated in differentiating neurons of the embryonic carcinoma cell line P19 whereas its overexpression in rat pheochromocytoma PC12 cells relocalised KGA from the mitochondria to neurite terminals. It also reduced the steady-state levels of glutamate by inhibiting KGA enzyme activity. These results strongly suggest that through binding to KGA, BNIP-H could regulate glutamate synthesis at synapses during neurotransmission. Thus, loss of BNIP-H function could render glutamate excitotoxicity or/and deregulated glutamatergic activation, leading to ataxia, dystonia or other neurological disorders.

Amino Acid Sequence↗

PubMed2006

Characterization of AMPA receptors targeted by the climbing fiber transmitter mediating presynaptic inhibition of GABAergic transmission at cerebellar interneuron-Purkinje cell synapses.

The climbing fiber (CF) neurotransmitter not only excites the postsynaptic Purkinje cell (PC) but also suppresses GABA release from inhibitory interneurons converging onto the same PC depending on AMPA-type glutamate receptor (AMPAR) activation. Although the CF-/AMPAR-mediated inhibition of GABA release provides a likely mechanism boosting the CF input-derived excitation, how the CF transmitter reaches target AMPARs to elicit this action remains unknown. Here, we report that the CF transmitter diffused from its release sites directly targets GluR2/GluR3 AMPARs on interneuron terminals to inhibit GABA release. A weak GluR3-AMPAR agonist, bromohomoibotenic acid, produced excitatory currents in the postsynaptic PCs without presynaptic inhibitory effect on GABAergic transmission. Conversely, a specific inhibitor of the GluR2-lacking/Ca2+-permeable AMPARs, philanthotoxin-433, did not affect the CF-induced inhibition but suppressed AMPAR-mediated currents in Bergmann glia. A low-affinity GluR antagonist, gamma-D-glutamylglycine, or retardation of neurotransmitter diffusion by dextran reduced the inhibitory action of CF-stimulation, whereas blockade of glutamate transporters enhanced the CF-induced inhibition. The results suggest that the CF transmitter released after repeated stimulation overwhelms local glutamate uptake and thereby diffuses from the release site to reach GluR2/GluR3 AMPARs on nearby interneuron terminals. Double immunostaining showed that GluR2/3 subunits and glutamate decarboxylase or synaptophysin are colocalized at the perisomatic GABAergic processes surrounding PCs. Finally, electron microscopy detected specific immunoreactivity for GluR2/3 at the presynaptic terminals of symmetric axosomatic synapses on the PC. These findings demonstrate that the CF transmitter directly inhibits GABA release from interneurons to the PC, relying on extrasynaptic diffusion and local heterogeneity in AMPAR subunit compositions.

Animals↗

PubMed2006

[A comparative research on RHD gene structures of Chinese Han and Uigur population].

OBJECTIVE: To research comparatively on the RHD gene structures in unrelated RhD negative individuals of Chinese Uigur and Han population. METHODS: The upstream, downstream, hybrid box and 10 exons of RHD gene were detected with sequence specific primer-PCR technique. RESULTS: The results showed the genotypes of RhD negative individuals to have the significant difference between Chinese Uigur and Han population, that 94.44% Uigur individuals were with RHD(-)/RHD(-) genotype but just 61.40% Han population were with this genotype(94.44% versus 61.40%, P<0.01); 2.78% Uigur individuals were with RHD(+)/RHD(-) genotype but 34.21% Han population were with this genotype(2.78% versus 34.21%, P<0.01). However, there was significantly no RHD(+)/RHD(+) genotype difference between Chinese Uigur and Han population(2.78% versus 4.39%, P>0.05). In 78 cases of RhD negative Chinese Hans with single RHD gene, of which the RHD gene structure showed that 53(67.95%) cases were RHD(1-10) allele(of 53 RHD(1-10) alleles, 14 alleles were unexpressed); 15(19.23%) were RHD-CE(2-9)-D(2) allele; 5(6.41%) cases were RHD-CE(2-7)-D(2) allele; 2(2.56%) were similar to RHD-CE(3-6)D allele; 1(1.28%) case was RHD-CE(5-6)-D allele; and 2(2.56%) were RHD-CE(6)-D or point mutation respectively. Of 2 RhD negative Chinese Uigurs with RhD(-)/RHD(+) genotype, one carried RHD(1-10) allele, another carried RHD-CE(2-9)-D(2) allele. CONCLUSION: The most frequently unexpressed RHD alleles were RHD-CE(2-9)-D(2), RHD(1-10) and RHD-CE(2-7)-D(2) respectively in Chinese Han population who carried single RHD allele with RHD(-) phenotype and RHD(+) genotype. It showed the confluent character of RH gene in Chinese Han and Uigur population that there existed unexpressed RHD-CE(2-9)-D(2) allele in Chinese Uigur nationality, which was infrequent in Chinese Uigur population but frequent in Chinese Han population.

Alleles↗

PubMed2005

Juxtanodin: an oligodendroglial protein that promotes cellular arborization and 2',3'-cyclic nucleotide-3'-phosphodiesterase trafficking.

In the process of screening cell-type-specific genes, we identified juxtanodin (JN), an oligodendroglial protein featuring a putative C-terminal actin-binding domain. At the cellular level, JN in the rat CNS colocalized with 2',3'-cyclic nucleotide-3'-phosphodiesterase (CNPase), a cytoskeleton-related oligodendroglial protein. In the myelin sheath, JN was found mainly in the abaxon and the lateral few terminal loops. Its apposition to the myelinated axon, through the latter, defined an axonal subregion, herewith termed juxtanode, at the Ranvier node-paranode junction. During forebrain ontogenesis, JN expression paralleled that of MBPs but lagged behind CNPase. Juxtanodin transfection promoted arborization of cultured OLN-93 cells and augmented endogenous CNPase expression and transport to the process arbors of cultured primary oligodendrocyte precursors. These results reveal JN as a cytoskeleton-related oligodendroglial protein that delineates the juxtanode and might serve oligodendrocyte motility, differentiation, or myelin-axon signaling. Functionally, JN may be involved in CNS myelination and/or specialization of the node of Ranvier.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

PubMed2005

Adipocyte/macrophage fatty acid binding proteins control integrated metabolic responses in obesity and diabetes.

Fatty acid binding proteins (FABPs) are cytosolic fatty acid chaperones whose biological role and mechanisms of action are not well understood. Here, we developed mice with targeted mutations in two related adipocyte FABPs, aP2 and mal1, to resolve their role in systemic lipid, glucose, and energy metabolism. Mice lacking aP2 and mal1 exhibited a striking phenotype with strong protection from diet-induced obesity, insulin resistance, type 2 diabetes, and fatty liver disease. These mice have altered cellular and systemic lipid transport and composition, leading to enhanced insulin receptor signaling, enhanced muscle AMP-activated kinase (AMP-K) activity, and dramatically reduced liver stearoyl-CoA desaturase-1 (SCD-1) activity underlying their phenotype. Taken together with the previously reported strong protection against atherosclerosis, these results demonstrate that adipocyte/macrophage FABPs have a robust impact on multiple components of metabolic syndrome, integrating metabolic and inflammatory responses in mice and constituting a powerful target for the treatment of these diseases.

AMP-Activated Protein Kinases↗

PubMed2005

Expression of an olfactomedin-related gene in rat hair follicular papilla cells.

Follicular papilla (FP) cells, but not their closely related dermal fibroblasts, can maintain hair growth suggesting cell type-specific molecular signals. To define the molecular differences between these two cell types, we generated a subtraction complementary DNA (cDNA) library highly enriched in FP-specific cDNA. Differential screening identified FP-1 as the most abundant cDNA sequence in this subtraction library. FP-1 message RNA is highly abundant in cultured rat vibrissa FP cells, can be detected at very low levels in the stomach and the ovary, and is undetectable in cultured dermal fibroblasts and in 16 rat non-follicular tissues. The full-length, 2.3 kb FP-1 cDNA encodes a protein of 549 amino acids harboring a signal peptide, collagen triple helix repeats, and an olfactomedin-like domain. Monospecific rabbit antibodies to FP-1 recognize in cultured FP cells a single approximately 72 kDa glycoprotein with a approximately 60 kDa protein core. FP-1 protein is expressed in vivo in a hair cycle-dependent manner, as it can be detected in FP during anagen, but not in catagen and telogen phases of the hair cycle. FP-1 is presumably a highly specific extracellular matrix protein synthesized by FP cells and may be involved in the organization of FP during certain phases of normal or pathological hair growth.

Amino Acid Sequence↗

PubMed2005

[Dynamic monitoring of graft-versus-host disease after allogeneic peripheral blood stem cell transplantation by soluble HLA-I antigen detection].

OBJECTIVE: To assess the value of dynamic monitoring of soluble human lymphocytic antigen-I (sHLA-I) in the prediction of graft-versus-host disease (GVHD) after allogeneic peripheral blood stem cell transplantation (PBSCT). METHOD: Sandwich enzyme-linked immunosorbent assay (ELISA) was used to quantitatively detect serum sHLA-I. The serum samples for testing were added into W6 32 monoclonal antibody-coated microtiter plate and incubated with anti-beta2m HRP followed by color development with the addition of the substrate. Serum sHLA-I level was measured in 63 healthy blood donors of Shanghai and in 24 PBSCT recipients before and and at different time points after the operation. RESULT: No changes in sHLA-I levels occurred in allogeneic PBSCT recipients without GVHD or with only grade I GVHD, but sHLA-I reached high levels in patients suffering GVHD II-IV(P<0.05), which was effectively lowered by the application of immunosuppressants. CONCLUSION: Measurements of sHLA-I levels can be valuable for monitoring GVHD after PBSCT.

Adolescent↗

PubMed2005

[Comparison of Rhesus boxes in Hans and Uighurs].

OBJECTIVE: To study the difference and similarity between Hans and Uighurs in regard to Rhesus box and its significance. METHODS: The sequence specific primers of upstream, downstream and hybrid Rhesus boxes were designed on the basis of RHD gene sequence. The upstream, downstream and hybrid Rhesus boxes were determined by polymerase chain reaction-sequence specific primer(PCP-SSP) and mismatched PCR. RESULTS: The percentage of RHD-/RHD-, RHD+/RHD- and RHD+/RHD+ genotypes ascertained in the unrelated Hans with RhD(-) were 61.40%, 34.21% and 4.39% respectively, while those in the unrelated Chinese Uighurs with RhD(-) were 94.44%, 2.78% and 2.78% respectively. Furthermore, all 6 cases of some other minorities were RHD-/RHD- types. The percentage of RHD-/RHD- and RHD+/RHD- genotypes ascertained in the unrelated Chinese Uighurs were significantly higher than those in Chinese Hans (P < 0.01), whereas no statistically significant difference in the percentage of RHD+/RDH+ genotype between the two groups was observed (P > 0.05). CONCLUSION: The Rh blood group of Uighurs in Xingjiang possesses both Oriental and Caucasian characteristics, which embodies a special ethnical aspect of the Chinese nation and is in accord with the anthropologic research results.

China↗

PubMed2005

Ex vivo expansion of T, NK and CD34+ cells from umbilical cord blood.

Umbilical cord blood stem cell transplantation (CBSCT) has made significant progress in treatment of lethal congenital or malignant disorders. Both the incidence and severity of GVHD from CBSCT were lower than that from bone marrow and peripheral blood stem cell transplantation, particularly for adult patients, but these advantages were also associated with higher rates of relapse. The immune-mediated effect of natural killer and cytotoxic T cells against residual tumor cells were shown to prevent relapse and to induce remission after bone marrow transplantation. To explore possibility of ex vivo expansion of T, NK and CD34(+) cells from umbilical cord blood, cord blood was expanded ex vivo with different combinations of cytokines, T and NK cells proliferation and differentiation were observed. CB MNCs were separated in Ficoll-Isopaque column and cultured in IMDM for 14 days with different recombinant cytokines. Cultured cells were collected and analyzed for progenitor/stem cell immunophenotyping at day 0, 3, 7, and 14 by using flow cytometry. The results indicated that all test groups cultured with different combinations of SCF, IL-3, IL-6, IL-7, IL-2 showed significant expansion of UCB MNC, compared with the group without cytokines. All test groups showed expansion effects on CD34(+) cells, CD34(+) percentage went up from 1.6% in fresh CB to the highest 11.9% in group D (SCF + IL-3, IL-6, IL-2). The CD34(+) cells peak displayed at day 7 of culture in group A and D, while in other two groups B and C appeared at day 14 of culture. The expansion multiple of CD34(+) cells in all test groups at day 7 of culture were from 10 to 50. The average value of CD3(+) T cell in fresh UCB was 18.7 +/- 4.3%, the CD3(+) T cells decreased sharply in the medium without any interleukin, while obvious increase were observed in the other test groups containing different combinations of cytokines. The maximal expansion multiple of CD3(+) T cells reached 2 times of the fresh UCB level. CD56(+) cells amounted to 3.6 +/- 1.9% of fresh UCB, CD56(+) cell number increased significantly only in medium containing IL-2. It is concluded that T cells, NK cells as well as stem/progenitor cells can be expanded in the same time from CB-MNC with the combinations of cytokines.

Antigens, CD34↗

PubMed2005

[A method for Rhesus box test].

To study the method for Rhesus box test and its significance, the sequence specific primers of upstream, downstream and hybrid Rhesus boxes were designed according to RhD gene sequence; the upstream, downstream and hybrid Rhesus boxes were determined by PCP-SSP and mismatched PCR. The results showed that this method was confirmed by DNA Standard test. It was shown that in unrelative RhD positive individuals RHD(+)/RHD(-), RHD(+)/RHD(+) genotype accounted for 9.00%, 91.00% respectively, and in RhD negative individuals RHD(+)/RHD(-), RHD(+)/RHD(+), RHD(-)/RHD(-) genotype were 26.14%, 3.92%, 69.94% respectively. It is concluded that the method of Rhesus box test was confirmed to be reliable and can be used for the identification of RhD haplotype gene structure, as well as for study on inheritance, clinical transfusion and neonatal hemolytic diseases.

Base Sequence↗

PubMed2004

Endoplasmic reticulum stress links obesity, insulin action, and type 2 diabetes.

Obesity contributes to the development of type 2 diabetes, but the underlying mechanisms are poorly understood. Using cell culture and mouse models, we show that obesity causes endoplasmic reticulum (ER) stress. This stress in turn leads to suppression of insulin receptor signaling through hyperactivation of c-Jun N-terminal kinase (JNK) and subsequent serine phosphorylation of insulin receptor substrate-1 (IRS-1). Mice deficient in X-box-binding protein-1 (XBP-1), a transcription factor that modulates the ER stress response, develop insulin resistance. These findings demonstrate that ER stress is a central feature of peripheral insulin resistance and type 2 diabetes at the molecular, cellular, and organismal levels. Pharmacologic manipulation of this pathway may offer novel opportunities for treating these common diseases.

Adipose Tissue↗

PubMed2004

Expression profiles of tyrosine kinases in cultured follicular papilla cells versus dermal fibroblasts.

Tyrosine kinases play crucial roles in cell differentiation and proliferation. Using degenerative primed PCR followed by differential display, we analyzed the tyrosine kinase expression profiles of cultured rat follicular papilla (FP) cells versus dermal fibroblasts. We showed that c-met, cdc2, and tec were preferentially expressed in cultured FP cells, whereas alpha-platelet-derived growth factor receptor (alpha-PDGFR) was preferentially expressed in cultured fibroblasts. The cell type specificity of these tyrosine kinases was confirmed by semi-quantitative RT-PCR using both rat and human cultured cells. Consistent with these results, hepatocyte growth factor preferentially stimulated the growth of rat FP cells, whereas PDGF-AA preferentially stimulated rat fibroblasts. High concentrations of some these kinases are also found in the follicular matrix keratinocytes as revealed by in situ hybridization. The expression of specific tyrosine kinases in FP and matrix cells may play roles in regulating hair growth and cycling.

Amino Acid Sequence↗

PubMed2004

[Method of detection of soluble HLA-I and soluble HLA-I level alteration in storage blood].

Aim of this study was to develop the detection method of soluble human leukocyte antigens I (sHLA-I) and to explore sHLA-I level alteration in storage blood and its significance. sHLA-I level in sera of 60 Guangdong normal individuals and sHLA-I concentration in blood components from 20 donors quantitatively were detected by sandwich ELISA. The results showed that sensitivity of this assay was 2.84 ng/ml. Coefficients of variation were 5.80% within assays and 9.00% between assays respectively. The recovery rate was >/= 98.57%. The sHLA-I level of normal individuals in Guangdong was (699.54 +/- 360.10) ng/ml. sHLA-I in red blood cells stored for 28 days and in random-donor platelets were significantly higher than that in other blood components and their amount was proportionate to the number of residual donor leukocytes and to the length of storage. In conclusion, sandwich ELISA assay for detection of sHLA-I is a sensitive, specific and stable technique. Blood components with different concentration of sHLA-I may be chosen for clinical transfusion.

Apoptosis↗

PubMed2003

[Observation on gene polymorphism of Rh blood group in Chinese Han nationality].

To observe the gene polymorphism of Rh blood group in unrelated random individuals and families for Chinese Han nationality, polymerase chain reaction-sequence specific primer (PCR-SSP) was used to amplify the Rh C/E gene, RhD gene, exons, intron 2 and 10, insert and Rh Box in 160 blood samples of RhD positive unrelated individuals and 71 samples of RhD negative unrelated individuals and 7 samples of families whose probands were RhD-negative. The results showed that RhD genes of RhD-negative individuals with C antigens were polymorphism, three forms were found for D exon including intact, partial deletion and complete deletion exons. Insert fragments and Rh Box were found in most cases of families whose probands were RhD-negative and its inheritance accorded with the Mendel's Law, and it did not affect the expression of RhD gene. "Normal" RhD exon 4 amplifying product was not found in all of the samples. It was concluded that gene structure of the RhD-negative in Chinese was polymorphism, intact, partial deletion and complete deletion exons were found in the individuals with C antigen and probably existed specific D (nf) Ce haplotype. The function of insert was uncertain. The Rh gene sequences of Chinese Han nationality are different from those of Caucasian and the Rh gene library based on Han nationality should be established.

Asian People↗

PubMed2001

[Research of Typing for HLA-A, -B on Cord Blood Lymphocytes]

Serological typing for HLA-A, -B has been used for a long time. Recently with the developing of molecular biology technologies, HLA-A, -B typing is now turning to genotyping methods. In our study, the capacity of PCR-SSP in solving problems in HLA-A, -B typing with serological methes was evaluated. With this aim the serological method was compared with PCR-SSP in 102 cord blood samples, and the results showed that 18.6% of 102 cord blood samples can't give a satisfactory detection, for 14 samples, give discrepant results with the 2 methods. It is mainly due to weak expression of HLA class I cord blood lymphocytes and the cross reaction of some antigens. About B 15 group, the further study was made, it was found that most of the B 15 splits is wrongly disassigned, especially among the B62-B75, B75/*1511(+)-B75/*1511(-), B46-*1511 antigens. It was concluded that DNA typing is more preferable than serological typing, about B 15 group, the subtyping or high resolution typing can be fulfilled at first in China.

Journal Article↗