The Proangiogenic Roles of Long NonCoding RNAs Revealed by RNA-Sequencing Following Oxygen-Glucose Deprivation/Re-Oxygenation.

BACKGROUND/AIMS: With advances in RNA-sequencing (RNA-seq), exploring the expression and transcripts of different classes of genes are now possible. Our purpose was to analyse to the long non-coding RNAs (lncRNAs) in mouse brain microvascular endothelial cells (bEnd.3) after oxygen-glucose deprivation/re-oxygenation (OGD/R). METHODS: RNA-seq was employed to explore the expression of lncRNAs, and quantitative real-time PCR (qRT-PCR) was used to identify the results of RNA-seq. Furthermore, the biological functions of the lncRNAs were identified by cell viability, wound healing, transwell, tube formation and immunofluorescent staining assays. Finally, the molecular mechanisms involving the differentially expressed lncRNAs were further explored by bioinformatics and Western blotting (WB). RESULTS: In total, 2710 lncRNAs were found, 33 of which were significantly differentially expressed, with 18 upregulated lncRNAs and 15 downregulated lncRNAs in brain microvascular endothelial cells following OGD/R. Among the dysregulated genes, G protein-coupled receptor 137b-pseudogene (Gpr137b-ps), predicted gene 32856 (Gm32856), small nucleolar RNA host gene 17 (snhg17), chaperonin containing Tcp1 and subunit 6a (Cct6a) were significantly upregulated lncRNAs; this finding was further validated using qRT-PCR. Moreover, Gene Ontology (GO) and Kyoto Encyclopaedia of Genes (KEGG) pathway analyses were employed to decipher the potential target genes and signaling pathways of the differentially expressed lncRNAs. Finally, we selected pseudogene-expressed lncRNA Gpr137b-ps as a candidate gene, and report for the first time that pseudogenes can mediate angiogenesis and their potential target genes, namely, 15-lipoxygenase1 (15-LOX1), Signal Transducer and Activator of Transcription 3 (S TAT3) and vascular endothelial growth factor (VEGF). CONCLUSION: Therefore, our study revealed that Gpr137b-ps plays critical roles in the process of angiogenesis, suggesting avenues for the development of future therapeutic strategies that contribute to promoting angiogenesis following I/R.

Long non-coding RNA MALAT1 regulates angiogenesis following oxygen-glucose deprivation/reoxygenation.

Long non-coding RNAs (lncRNAs) have been identified as playing critical roles in multiple diseases. However, little is known regarding their roles and mechanisms in post-stroke angiogenesis. Our studies focused on deciphering the functional roles and the underlying mechanisms of the lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in the process of angiogenesis following oxygen-glucose deprivation/reoxygenation (OGD/R). We characterized the up-regulation of MALAT1 expression in the process of angiogenesis after hypoxic injury in vivo and in vitro. We further showed that compared with the empty vector, MALAT1 knockdown had significantly reduced the capacity for angiogenesis, which was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT), scratching, cell cycle and immunofluorescent staining. Thus, our findings suggest that MALAT1 may mediate proangiogenic function in OGD/R. To further explore the potential mechanisms, we used lentiviruses expressing shMALAT1 and empty vector; the results revealed that shMALAT1 reduced the expression of 15-lipoxygenase 1 (15-LOX1), vascular endothelial growth factor (VEGF) and the phosphorylation of signal transducers and activators of transcription 3 (pSTAT3). Taken together, our results are the first to propose that MALAT1 may regulate angiogenesis through the 15-LOX1/STAT3 signalling pathway, and they may provide a critical target for the treatment of hypoxic injury and an avenue for therapeutic angiogenesis.

New isolates from leaves of Nicotiana tabacum and their biological activities.

Three new isolates (1-3) including one new sterol and two new flavonoids together with three known sterols (4-6) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly by spectroscopic methods, including extensive 1D and 2D NMR techniques. All compounds were evaluated for their anti-tobacco mosaic virus and cytotoxic activities. The results showed that compounds 2 and 3 exhibited high anti-TMV activity with inhibition rate of 34.2 and 33.4%, respectively, which were roughly equivalent to that of positive control. The cytotoxicities of compounds 1 and 4-6 against five human tumour cell lines were also tested, and tested compounds showed weak inhibitory activities against some tested human tumour cell lines.

Impaired cross-activation of ß3 integrin and VEGFR-2 on endothelial progenitor cells with aging decreases angiogenesis in response to hypoxia.

BACKGROUND: The mechanism by which vascular regeneration declines with aging is not fully understood. An interaction between integrin and vascular endothelial growth factor receptor-2 (VEGFR-2) plays a substantial role in angiogenesis. Here, we investigated whether aging impairs this interaction in endothelial progenitor cells (EPCs) under hypoxia. METHODS AND RESULTS: Aging reduced the blood flow and vessel density in ischemic muscles in mice. Levels of phosphorylated Src (p-Src), p-ß3, and p-VEGFR-2 in acute ischemia were reduced in the muscles of aged mice compared to young mice. The hypoxia-inducible factor (HIF)-1α stabilizer deferoxamine improved the age-related impairment of angiogenesis, but this effect was diminished by LY290004, an inhibitor of phosphatidylinositol 3-kinase. Deferoxamine improved the reduction in chronic ischemia-induced ß3-integrin and VEGFR-2 phosphorylation in the muscles of aged mice; this effect was also diminished by LY290004. In EPCs, we identified the molecular requirements for VEGF-mediated ß3-integrin and VEGFR-2 cross-activation in vitronectin-induced cell adhesion under acute hypoxia. We demonstrated that c-Src controlled the adhesion- and VEGF-induced ß3 tyrosine phosphorylation in hypoxia. Aging enhanced the hypoxia-induced EPC apoptosis and impaired several c-Src-related VEGF-induced receptor events, including ß3 tyrosine activation, ligand binding, cell adhesion, and tubulogenesis in cultured EPCs of animals and those of humans. CONCLUSIONS: These data suggest that the aging-related decline in angiogenic action in response to ischemia is mediated by the impairment of cross-activation between ß3 and VEGFR-2 in EPCs, which is partially associated with decreased HIF-1α stability.

[Influence of storage period and grading standards on quality of Prunella vulgaris].

OBJECTIVE: To investigate the influence of storage period and grading standards on the quality of Prunella vulgaris in order to provide a theoretical basis for standardized cultivation. METHOD: The spices of P. vulgaris in different storage period (including current year, first-year and second-year) were collected from Lujiang base in Anhui Province. The samples were randomized, with the methods of morphologic characteristics and commercial size on P. vulgaris, the samples were graded into three grades; according to the methods from the Pharmacopoeia of the People's Republic of China, water-soluble extracts, ethanol-soluble extracts, total ash and acid insoluble ash were measured, respectively, utilizing the UV spectrophotometry to detection the contents of total flavonoids and polysaccharides, the levels of ursolic acid, oleanolic acid and rosmarinic acid were adopted by HPLC. RESULT: The total ash and acid insoluble ash of P. vulgaris showed significantly increase during prolonged storage; however, the content of water-soluble extracts, ethanol-soluble, total flavonoids, polysaccharides, ursolic acid, oleanolic acid,rosmarinic acid showed significantly decrease during prolonged storage. The spica of P. vulgaris exhibited no rules differences between the quality and grading standards, The second-degree belongs to high content of total flavonoids; the high content of polysaccharides was first-degree; the total ash and acid insoluble ash of spicas exhibited gradually decreased from first-degree to third-grade, and the content of water-soluble extracts, ethanol-soluble extracts,ursolic acid,oleanolic acid, rosmarinic acid showed gradually increased from first-degree to third-grade. CONCLUSION: The current year was a suitable storage time of spicas from P. vulgaris could be selected; and the main bioactive components highest level of P. vulgaris spicas was third-degree, second-grade next, first-degree minimum.

[Study on the analysis of high-resolution HLA-A,B and DRB1 alleles from 3238 hematopoietic stem cell donors in Jiangsu Han Chinese].

OBJECTIVE: To analyze the genetic polymorphism, distribution of haplotypes, common and well-documented (CWD) and rare alleles of high-resolution HLA-A, B and DRB1 alleles by analysis from hematopoietic stem cell (HSC) donors in Jiangsu Han Chinese. METHODS: PCR-sequence-based typing and PCR-sequence specific oligonucleotide probes methods were applied for HLA-A, B and DRB1 high-resolution genotyping of 3238 unrelated healthy donors of hematopoietic stem cells in Jiangsu branch of Chinese National Marrow Donor Program registry. RESULTS: 46 alleles of HLA-A,85 HLA-B and 51 HLA-DRB1 locus were found. The frequencies of the most common alleles were A * 11:01 (16.52%), B * 13:02 (11.60%) and DRB1 *07:01 (15.78%). That of the most common haplotype was A * 30: 01-B * 13: 02-DRB1 * 07: 01 (8.87%). 40 alleles of HLA-A,77 alleles of HLA-B, and 47 HLA-DRB1 alleles of HLA-DRB1 were CWD, which account for 99. 8% of total number of samples, and a few rare alleles not reported in Chinese population were found. CONCLUSION: The results of high-resolution, CWD and rare alleles showed the characteristics of HLA distribution in Jiangsu Han population, which may be useful for finding HLA matched unrelated donors, as well as for HLA correlation with population genetics and disease association studies.

[Proteasome inhibitor bortezomib inducing apoptosis of K562 cells not affected by bone marrow mesenchymal stem cells in vitro].

The study was aimed to investigate the effects of proteasome inhibitor bortezomib on the apoptosis of K562 cells in the presence of bone marrow mesenchymal stem cells, and explore its effect on expression of adhesion molecule VCAM-1 of both MSC and K562 cells. The K562 cells were co-cultured in direct contact with MSC, while the control cells were just cultured alone. Bortezomib was administered at a final concentration of 50 nmol/L. Cell apoptosis was assayed by flow cytometry with Annexin-V/PI double staining kit. The VCAM-1 gene expression was determined by reverse transcription polymerase chain reaction (RT-PCR). The results indicated that bortezomib could induce apoptosis of K562 cells in a time-dependent manner. K562 cells growing on the layer of MSC demonstrated the similar sensitivity to apoptosis induction of bortezomib. K562 cells which did not express VCAM-1 originally were induced to express VCAM-1 mRNA when co-cultured with MSC. This effect could be abrogated by bortezomib treatment. Furthermore, bortezomib significantly downregulated the VCAM-1 expression of MSC. It is concluded that the proteasome inhibitor bortezomib can induce apoptosis of K562 cells even though in presence of the MSC layer.

The distribution of human leukocyte antigen-A, -B, and -DRB1 alleles and haplotypes based on high-resolution genotyping of 167 families from Jiangsu Province, China.

We investigated the human leukocyte antigen (HLA)-A, -B, and -DRB1 allele frequencies, the A-B-DRB1, A-B, B-DRB1, and A-DRB1 haplotype frequencies, and the characteristics of linkage disequilibrium between 2 loci in high resolution based on 167 unrelated families from Jiangsu Province, China. A total of 26 alleles at the A locus, 55 alleles at the B locus, and 34 alleles at the DRB1 locus were reported in this study. The top 5 most frequent HLA alleles at the HLA-A, -B, and -DRB1 loci, respectively, were A*11:01, A*24:02, A*02:01, A*33:03, A*30:01; B*13:02, B*40:01 B*46:01, B*58:01, B*54:01; DRB1*09:01, DRB1*07:01, DRB1*12:02, DRB1*15:01, and DRB1*08:03. Several haplotypes with high frequencies were deduced in this study. The top 3 most common A-B-DRB1 haplotypes observed were A*30:01-B*13:02-DRB1*07:01, A*33:03-B*58:01-DRB1*03:01, and A*02:07-B*46:01-DRB1*09:01. The top 3 most common A-B haplotypes were A*30:01-B*13:02, A*33:03-B*58:01, and A*02:07-B*46:01. The top 4 most common A-DRB1 haplotypes were A*30:01-DRB1*07:01, A*33:03-DRB1*13:02, A*24:02-DRB1*09:01, and A*33:03-DRB1*03:01. Finally, the top 3 most common B-DRB1 haplotypes were B*13:02-DRB1*07:01, B*46:01-DRB1*09:01, and B*58:01-DRB1*03:01. From the linkage disequilibrium calculation, the most prominent associations were A*30:01-B*13:02, B*13:02-DRB1*07:01, and A*01:03-DRB1*01:02. These allele and haplotype frequencies could be useful for finding the best matched donors for patients in the China Marrow Donor Program Jiangsu Branch.

The distribution of HLA-A, -B, and -DRB1 alleles and haplotypes in inhabitants of Guizhou Province of China.

The present study was aimed to analyze the frequencies of human leukocyte antigen (HLA)-A, -B, and -DRB1 alleles and A-B-DRB1, A-B, A-DRB1 and B-DRB1 haplotypes in inhabitants of Guizhou province, China. All samples were typed in the HLA-A,-B, and -DRB1 loci using the polymerase chain reaction-reverse sequence specific oligonucleotide probe (PCR-rSSOP) method and HLA polymorphisms were analyzed. A total of 18 HLA-A, 31 HLA-B, and 13 HLA-DRB1 alleles were found in the Guizhou population. The first two frequent alleles in the HLA-A, -B, and -DRB1 loci were A*11(30.72%) and A*02(30.65%), B*40(16.27%) and B*46(16.27%), and DRB1*09(15.91%) and DRB1*15(13.51%), respectively. The most common haplotype was A*02-B*46-DRB1*09(5.59%) in A-B-DRB1, A*02-B*46(11.73%) in A-B, B*46-DRB1*09(7.49%) in B-DRB1, and A*02-DRB1*09(8.08%) in A-DRB1. Some haplotypes with strong linkage disequilibrium (LD) were found not only in the common haplotypes, such as A*33-B*58, B*30-DRB1*07, and B*33-DRB1*03, but also in the rare haplotypes, such as A*01-B*37, B*37-DRB1*10, and A*01-DRB1*10. Guizhou inhabitants shared some characteristics of the Southern Chinese population but also had their own unique features. Overall, HLA polymorphism in Guizhou population was more consistent with that of Chengdu population than that of other populations in China.

[Absorption and allocation of nitrogen, phosphorus, potassium in Prunella vulgaris and their relationship to dry matter accumulation].

OBJECTIVE: The accumulation of dry matter, nitrogen, phosphorus and potassium in Prunella vulgaris and their relationships under field condition were studied, in order to provide a basis for the rational fertilization. METHOD: Through the dynamic sampling of P. vulgaris in different growing stages, and the dry weight of plant, the amount of dry matter and the content of N, P and K within each organ of the plant were measured. RESULT: The dry weight of P. vulgaris linearly increased with the increase of nitrogen, phosphorus and potassium accumulation, there existed a significant correlation at whole growth period. The maximum stage accumulation rate of dry matter from mid-April to the beginning of May, reached 63.71%. The amount of dry matter was mainly distribution in leaves from late March to mid-April. The distribution ratio in stem was the highest from beginning of May to late May. Until mid-June, the distribution ratio of dry matter in spicas was higher than that in other organs. The absorption amounts of N, P and K were lower before mid-April, and the nutrient element was concentrated in plant leaves. From late April to beginning of May, the N, P and K accumulation reached maximum of total absorptive capacity, which accounted for 72.35%, 59.82%, 87.41%, respectively, and the mineral elements were concentrated distribution of plant stems. When transferred to reproductive stage, both accumulation amount and distribution rate of nutrient elements in spicas increased rapidly, which reached the maximum until mid-June. From elongation stages to quaring period was the period of maximal accumulation of dry matter and showed the maximal efficiency of N, P and K nutrition. CONCLUSION: The time from elongation stages to quaring period is the most crucial period in the growth development stage of P. vulgaris, and should be paid more attention to the supply of mineral nutrition and moisture of plant to promote spicas formation and dry matter accumulation in this stage. The average N, P2O5 and K2O absorption amount per 100 kg dry matter of spicas were 1.62, 0.36, 2.88 kg respectively, and the ratio of N-P2O5,-K2O was 1 : 0.22: 1.77.

[Study on content and distribution characteristics of mineral elements from cultivated and wild Prunella vulgaris].

OBJECTIVE: The contents of mineral elements in soil and each organ from cultivated and wild Prunella vulgaris were determined in order to provide a theoretical basis for exploitation and protection of wild resources and GAP study. METHOD: The contents of mineral elements (P, K, Ca, Mg, Na, Fe, Cu, Zn, Mn, Al) in soil and each organ from cultivated and wild P. vulgaris were determined by ICP-AES, and the results were analyzed by correlation analysis. RESULT: The contents of mineral elements in soil and different organs of P. vulgaris were significant different between cultivated and wild species; the contents of P and Cu ranked in the order of spica > leaf > stem, the order of Mg, Ca, Zn, Fe, Mn, Al from high to low was leaf > spica > stem, the concentrations of K, Na were mainly distributed in leaf and stem, less in spica. A distinctly positive correlation between soil and spica for Fe content, and the relationship between soil and leaf, stem were significant positive correlation, the concentrations of Zn in spica, leaf, stem were positively related to soil, K contents in soil and stem were significant positive correlation. The different organs of cultivated and wild P. vulgaris had a strong tendency to accumulate P. CONCLUSION: There was no direct relationship between the concentrations of mineral elements in P. vulgaris, and their corresponding soil P. vulgaris adjusts the concentration of mineral elements mainly by active absorption.

[Effect of optimized fertilization on spicas biomass and yield of Prunella vulgaris].

OBJECTIVE: To study the effects of nitrogen (N), phosphorus (P2O5), potassium (K2O) and organic compound fertilizer (OF) on spicas biomass and yield of Prunella vulgaris in order to provide a theoretical basis for good agriculture practice (GAP). METHOD: Field plot experiments with a 4-variable quadratic orthogonal rotation combination design were adopted, and a function model of spicas yield in P. vulgaris was established. RESULT: The model analysis showed that spicas yields of P. vulgaris were significantly influenced under the N, P2O5 and K2O applications, among there factors, N had the greatest effects on spicas yield of P. vulgaris, the next was P2O5 and K2O, OF had the smallest effects on spicas yield. At the lower fertility levels, the spicas yields of P. vulgaris were improved along with the increasing of N, P2O5, K2O and OF applications, but the spicas yields decreased when N, P2O5, K2O and OF were applied too much. CONCLUSION: In this experiment condition, the spicas yields of P. vulgaris could reach to 722 kg x hm(-2) when the fertilizer rates were N 303. 9-335.1 kg x hm(-2), P2O5 432.5-500.6 kg x hm(-2), K2O 206.6-240.2 kg x hm(-2), OF 2 312.5-2 687.5 kg x hm(-2).

[Textual research on change of medicinal parts and herbal medicine of Prunella vulgaris].

OBJECTIVE: To investigate the herbal medicine of Prunella vulgaris by textual researches, and provide a theoretical basis for clinical medication, exploitation and protection of wild P. vulgaris resources. METHOD: Textual research on medicinal works of past dynasties and field work were adopted. RESULT: The natural distributions of P. vulgaris were concentrated distribution in Sichuan province, Huaihe river basin, and Middle-Lower Yangtze river valley in Chinese history. The indications of P. vulgaris in ancient and modern times were basically identical. While there were difference between the medicinal parts, harvest period and processing methods existed difference between ancient and modern. CONCLUSION: Three periods that whole grass of P. vulgaris as medicinal parts (from late Ming dynasty to late Qing dynasty and early stage of Republic of China), both whole grass and spicas as medicinal parts (from mid-term Republic of China to 1963), and the semi-maturity or maturity of spicas as medicinal parts (from 1963 to today) existed. The processing method for medicinal parts of P. vulgaris adopted sun drying and shady drying in ancient China, but only the sun drying was only used in modern times.

[Distribution of chemical constituents in Changium smyrnioides].

OBJECTIVE: To analyze the distribution of chemical constituents in different parts of Changium smyrnioides. METHOD: The content of polysaccharides, mannitol and choline was determined by colorimetry and the water-soluble components was determined by HPLC. similarity coefficient of water-soluble components was calculated by the included angle cosine method. RESULT: The Contents of chemical constituents were significantly different between the leaves and the roots. The contents of choline and polysaccharides in the roots was higher than those in the leaves, but the contents of water-soluble extract and physiological ash in the leaves was higher than those in the roots. Contents of chemical constituents were also significantly different at different segments in the root, which decreased from the upper to the lower parts, increased from the outside to the inside parts except physiological ash, and the difference in horizontal segments was higher than that in vertical segments. Total peak area of water-soluble components in the leaves was 2.81 times higher than that in the roots, and gradually increased from the outside to the inside parts. CONCLUSION: Total content of chemical constituents in the leaves was significantly higher than that in the roots. The quality of medicinal used parts decreased gradually from the inside to the outside parts and from the upper to the lower parts in the root of Ch. smyrnioides.

[Change of chemical constituents in Changium smyrnioides at different ages].

OBJECTIVE: To analyze the dynamic change of chemical constituents in Changium smyrnioides at different ages and give a reference for standard cultivation. METHOD: The contents of polysaccharides, mannitol and choline in the roots were determined by colorimetry. HPLC was used to analyze water-soluble components in the roots. GC-MS was used to analyze volatile oil components in the leaves. Similarity coefficient of water-soluble components was calculated by included angle cosine method. RESULT: There was significant difference in content of the analyzed chemical constituents except polysaccharide. Contents of mannitol, physiological ash and polysaccharide in the adult plant were higher than those in the young plant. On the contrast, content of water-soluble components and choline in the young plant was higher than that in the adult plant. With the increase of the growth years, water-soluble components in the roots and volatile oil components in the leaves were gradually concentrated. CONCLUSION: The growth time significantly affects the chemical constituents in Ch. smyrnioides, the reasonable harvest time is from the second to the forth year after transplanting.

[Genetic variation, correlation and principle component analysis on morphological characteristics of various germplasm from Prunella vulgaris].

OBJECTIVE: To study the correlation among the morphological characteristics and the spica yield of various germplasm of Prunella vulgaris. METHOD: The various P. vulgaris germplasm from all over the country were investigated by analysis of correlation analysis, path analysis and principle component analysis in a randomized block experiment. RESULT: The 6 morphological characteristics were greatly different from each other in various germplasm. The spica yield per plant had a very significantly positive correlation with the number of spica per plant and fresh leaves weight per plant, meanwhile the correlation between the spica yield per plant and spica length was very significantly. Three principal components which accounted for 87.533% of total variance were extracted from the principal component analysis. CONCLUSION: The strong growth potential, the number of spica per plant and spica length were main factors for the selection of high yield breeding of P. vulgaris.

[Human bone marrow stromal cells facilitate the cord blood CD34+ cells ex vivo expansion and short-term engraftment in NOD/SCID mice].

OBJECTIVE: To explore the potential of human bone marrow stromal cells (MSCs) as the feeding-layer to promote ex vivo expansion of cord blood CD34+ cells and engraftment of the expanded cells in NOD/SCID mice. METHODS: Human MSCs were routinely isolated and cultured. MSCs at passage 3 were used as feeding-layer for the expansion of cord blood CD34+ cell in the presence of thrombopoietin (TPO), flt3/flk2 ligand (FL), stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF). The engraftment potential between unexpanded and expanded cord blood cells transplanted into NOD/SCID mice was compared. RESULTS: The total nucleated cells (TNC), CD34 cells and colony forming units (CFUs) in the MSC feeding culture were increased by 111.6-, 19.3- and 58-fold after 1 week expansion and 532.8-, 41.3- and 563.5- fold increased after 2 weeks expansion respectively as compared with that in non MSC feeding culture. In transplant experiment, the percentage of human CD45+ cells (45.3% -59.1%) in bone marrow of recipient mice transplanted with the MSC feeding expanded cells was the highest in all the groups at six weeks after transplantation. CONCLUSION: Human MSCs enhance CB CD34+ cells in vitro expansion and their capacity of short-term engraftment in NOD/SCID mice.

[Effect of co-culture of bone marrow mesenchymal stem cells and K562 cells on expression of interleukin 8].

To investigate the effects of interaction between human bone marrow mesenchymal stem cells (MSCs) and K562 cells on the expression of proangiogenic factor IL-8, the K562 cells were co-cultured in direct contact with MSCs or cultured in MSCs conditioned medium while the controlled K562 cells were cultured alone. The IL-8 gene expression of K562 cells and MSCs was determined by RT-PCR. The results indicated that the expression of IL-8 in K562 cells when co-cultured in direct contact with MSCs or cultured in MSCs conditioned medium was obviously higher than that of K562 cells cultured alone (p<0.01). MSCs co-cultured with K562 cells also had an increased level of IL-8 compared with MSCs cultured alone (p<0.01). It is concluded that the interaction between MSCs and K562 cells via direct contact and the cytokine network promotes expression of IL-8.

[The population genetics study in HLA field].

Human leukocyte antigen (HLA) is the most polymorphic genetic system found in human genome. The polymorphisms of different HLA genes and haplotypes in different ethnic and geographic populations are of high importance for investigation of their population genetic characteristics and searching for HLA matched unrelated hematopoietic stem cell transplantation donors, as well as in disease association studies. The HLA molecular genetic principals and the progress of HLA population investigation were reviewed, as well as the methods applied in the field.

[Expression of HOXB4 in cord blood progenitor cells expanded in vitro].

HOXB4, a member of homeobox gene family, is closely related to the self-renewing and proliferative ability of primitive hematopoietic stem/progenitor cells (PHSC/PHPC). This study was aimed to investigate the self-renewing level of cord blood progenitor cells (CBPC) expanded in vitro. The HOXB4 expression at mRNA level was assayed by using real time RT-PCR. The results indicated that as culture prolonged, the total cells, CD34(+) cells greatly increased, however the HOXB4 expression gradually declined, even down to undetectable level similar to that of mature lymphocytes. Meanwhile, it was shown that CD34(+) cells co-cultured with bone marrow mesenchymal stem cells (BM-MSC) could abate the decline of HOXB4 expression. It is concluded that the self-renewing potential of CD34(+) cells gradually decreased during expansion in vitro, co-culture with BM-MSC was helpful to CD34(+) cell expansion and slowed the loss trend of its self-renewal.