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Double-stranded RNA enhances the expression of galectin-9 in vascular endothelial cells.

Treatment of cells with double-stranded RNA (dsRNA) in vitro mimics viral infection and regulates expression of various genes. We addressed the mechanisms of leucocyte traffic across the vascular endothelium induced by dsRNA. The present study focused on the expression of galectin-9, which is one of key molecules in the regulation of the interaction between vascular wall and white blood cells. Human umbilical vein endothelial cells (HUVEC) in culture were treated with polyinosinic-polycytidylic acid (poly IC), and expression of mRNA and protein of galectin-9 was analysed by reverse transcription polymerase-chain reaction (RT-PCR) and Western blotting. Poly IC enhanced the expression of galectin-9 mRNA and protein in concentration- and time-dependent manners. This effect of poly IC was almost completely suppressed by the pretreatment with 2-aminopurine, an inhibitor of dsRNA-dependent kinase. Poly IC treatment of HUVEC also enhanced the adherence of EoL-1 cells to the cells, which was inhibited by co-treatment with lactose. We conclude that poly IC upregulates galectin-9 expression in the vascular endothelium and this may explain part of the mechanism for leucocyte traffic through the vascular wall.

Base Sequence↗

Decrease of nuclear reactivity to growth-regulatory galectin-1 in senescent human keratinocytes and detection of non-uniform staining profile alterations upon prolonged culture for galectin-1 and -3.

Summary Multipotent stem cells (source for interfollicular epidermis, hairs and sebaceous glands) are localized in the bulge region of the outer root sheath of hair follicles, while stem cells giving rise to interfollicular epidermis reside in its basal. Using the multifunctional lectin galectin-1 as a marker to localize accessible binding sites in situ as a step to figure out galectin functionality in stem cells, we studied hair follicle-derived keratinocytes. Specific nuclear binding of galectin-1 associated with expression of DeltaNp63alpha, a potential marker of epidermal stem cells, was detected. Binding of chimera-type galectin-3 to a nuclear site was not found in parallel assays. During the process of ageing in culture when cells acquire properties of senescence, disappearance of the nuclear signal for galectin-1 binding was accompanied by a similar decrease of nuclear DeltaNp63alpha expression and increased binding of galectin-3 to the cell membrane, namely in regions of intercellular contacts. Expression of cytokeratin 10, a marker of the terminal differentiation was seen only in a small fraction of the cell population. These data extend the evidence for nuclear sites with galectin-1 reactivity in squamous epithelial cells, the expression of which is modulated upon senescence. Moreover, the results document the divergence of galectin-1 and -3 on the level of ligand selection in this cell type, underscoring the importance of the technical aspect to employ tissue lectins as probe and to perform a fingerprinting with several markers of the galectin family in parallel.

Aging↗

Efficacy of galectins in the amelioration of nephrotoxic serum nephritis in Wistar Kyoto rats.

BACKGROUND: Galectins are characterized by specific affinity for beta-galactoside sugars, and they play a role in diverse biological processes, including cell adhesion, cell proliferation, and apoptosis. Galectin-1, -3, and -9 have been implicated in modulating the immune response. METHODS: Nephrotoxic serum nephritis, which is characterized by crescent formation and glomerular influx of CD8+ cells into glomerular capillaries, was induced in Wistar Kyoto (WKY) rats by injecting rabbit antiglomerular basement membrane serum. Following induction, the rats were treated either with phosphate-buffered saline or dexamethasone, galectin-1, galectin-3, or galectin-9 on alternate days and were sacrificed at day 14. At day 8, splenic lymphocytes were isolated and employed for terminal deoxytransferase-mediated uridine triphosphate nick end-labeling (TUNEL) assay to assess the degree of apoptosis, and the kidneys were utilized to determine the extent of influx of CD4(+) and CD8(+) cells and glomerular damage. RESULTS: Dexamethasone induced a marked apoptosis of splenic CD4(+) and CD8(+) cells, and it inhibited the production of anti-rabbit IgG and the influx of CD8+ cells and macrophages into the renal glomeruli. Crescent formation and excretion of urinary proteins were also reduced. Galectin-9 failed to induce apoptosis in the CD4(+) cells; however, it induced apoptosis in the CD8(+) cells and inhibited the infiltration of CD8(+) cells. Although galectin-1 and -3 did not induce the apoptosis in the T cells, they inhibited the accumulation of macrophages in the renal glomeruli. Like dexamethasone, the galectins also reduced the crescentic formation, proliferation of glomerular cells, and excretion of urinary proteins. CONCLUSIONS: Galectin-9 selectively induces apoptosis of the activated CD8(+) cells, while the macrophage influx into the kidney is modulated by all three galectins. This finding raises an interesting possibility for the utility of galectins in the modulation of macrophages that are involved in immune-mediated glomerular diseases.

Adjuvants, Immunologic↗

Galectins are differentially expressed in supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas, and significantly modulate tumor astrocyte migration.

Galectins, a family of mammalian lectins with specificity to beta-galactosides, are involved in growth-regulatory mechanisms and cell adhesion. A relationship is assumed to exist between the levels of expression of galectins and the level of malignancy in human gliomas. A comparative study of this aspect in the same series of clinical samples is required to prove this hypothesis. Using computer-assisted microscopy, we quantitatively characterized by immunohistochemistry the levels of expression of galectins-1, -3 and -8 in 116 human astrocytic tumors of grades I to IV. Extent of transcription of galectins-1, -3, and -8 genes was investigated in 8 human glioblastoma cell lines by means of RT-PCR techniques. Three of these cell lines were grafted into the brains of nude mice in order to characterize in vivo the galectins-1, -3 and -8 expression in relation to the patterns of the tumor invasion of the brain. The role of galectin-1, -3 and -8 in tumor astrocyte migration was quantitatively determined in vitro by means of computer-assisted phase-contrast videomicroscopy. The data indicate that the levels of galectin-1 and galectin-3 expression significantly change during the progression of malignancy in human astrocytic tumors, while that of galectin-8 remains unchanged. These three galectins are involved in tumor astrocyte invasion of the brain parenchyma since their levels of expression are higher in the invasive parts of xenografted glioblastomas than in their less invasive parts. Galectin-3, galectin-1, and to a lesser extent galectin-8, markedly stimulate glioblastoma cell migration in vitro. Since bands for the transcripts of human galectins-2, -4 and -9 were apparently less frequent and intense in the 8 human glioblastoma cell lines, this system provides an excellent model to assign defined roles to individual galectins and delineate overlapping and distinct functional aspects.

Adolescent↗

Evidence for a role for galectin-1 in pre-mRNA splicing.

Galectins are a family of beta-galactoside-binding proteins that contain characteristic amino acid sequences in the carbohydrate recognition domain (CRD) of the polypeptide. The polypeptide of galectin-1 contains a single domain, the CRD. The polypeptide of galectin-3 has two domains, a carboxyl-terminal CRD fused onto a proline- and glycine-rich amino-terminal domain. In previous studies, we showed that galectin-3 is a required factor in the splicing of nuclear pre-mRNA, assayed in a cell-free system. We now document that (i) nuclear extracts derived from HeLa cells contain both galectins-1 and -3; (ii) depletion of both galectins from the nuclear extract either by lactose affinity adsorption or by double-antibody adsorption results in a concomitant loss of splicing activity; (iii) depletion of either galectin-1 or galectin-3 by specific antibody adsorption fails to remove all of the splicing activity, and the residual splicing activity is still saccharide inhibitable; (iv) either galectin-1 or galectin-3 alone is sufficient to reconstitute, at least partially, the splicing activity of nuclear extracts depleted of both galectins; and (v) although the carbohydrate recognition domain of galectin-3 (or galectin-1) is sufficient to restore splicing activity to a galectin-depleted nuclear extract, the concentration required for reconstitution is greater than that of the full-length galectin-3 polypeptide. Consistent with these functional results, double-immunofluorescence analyses show that within the nucleus, galectin-3 colocalizes with the speckled structures observed with splicing factor SC35. Similar results are also obtained with galectin-1, although in this case, there are areas of galectin-1 devoid of SC35 and vice versa. Thus, nuclear galectins exhibit functional redundancy in their splicing activity and partition, at least partially, in the nucleoplasm with another known splicing factor.

Antibodies, Monoclonal↗

"Galectin-1 induces central and peripheral cell death: implications in T-cell physiopathology".

The immune system has a remarkable capacity to maintain a state of equilibrium even as it responds to a diverse array of foreign proteins and despite its contact exposure to self-antigens. Apoptosis is one of the mechanisms aimed at preserving the homeostasis after the completion of an immune response, thus returning the immune system to a basal state and warranting the elimination of autoagressive cells in both central and peripheral lymphoid organs. Targeted deletions in critical genes involved in the apoptotic death machinery together with natural spontaneous mutations have clearly shown the importance of apoptosis in the regulation of the immune response. This complex scenario of stimulatory and inhibitory genes has been enriched with the finding that galectin-1, a 14.5 kDa beta-galactoside-binding protein, is able to induce apoptosis of immature cortical thymocytes and mature T cells by cross-linking cell surface glycoconjugates. Galectin-1 is present not only in central and peripheral lymphoid organs, but also at sites of immune privilege. In the present article we will discuss the implications of galectin-1-induced apoptosis in T-cell physiopathology in an attempt to validate its therapeutic potential in autoimmune and inflammatory diseases.

Animals↗

Regulatory roles of galectins in the immune response.

Galectins are a family of animal lectins with affinity for beta-galactosides. They are differentially expressed by various immune cells and their expression levels appear to be dependent on cell differentiation and activation. They can interact with cell-surface and extracellular matrix glycoconjugates (glycoproteins and glycolipids), through lectin-carbohydrate interactions. Through this action, they can promote cell growth, affect cell survival, modulate cell adhesions, and induce cell migration. They appear to do so by binding to different glycoconjugates decorated by suitable saccharides, rather than through specific receptors. Galectins do not have a classical signal peptide and are often localized in intracellular compartments, including the nucleus. Intracellularly, they can regulate cell growth and survival by interacting with cytoplasmic and nuclear proteins, through protein-protein interactions, thereby affecting intracellular signaling pathways. Current research indicates that galectins play important roles in the immune response through regulating the homeostasis and functions of the immune cells.

Adjuvants, Immunologic↗

Prognostic significance of endogenous adhesion/growth-regulatory lectins in lung cancer.

OBJECTIVE: To determine the expression of endogenous adhesion/growth-regulatory lectins and their binding sites using labeled tissue lectins as well as the binding profile of hyaluronic acid as an approach to define new prognostic markers. METHODS: Sections of paraffin-embedded histological material of 481 lungs from lung tumor patients following radical lung excision processed by a routine immunohistochemical method (avidin-biotin labeling, DAB chromogen). Specific antibodies against galectins-1 and -3 and the heparin-binding lectin were tested. Staining by labeled galectins and hyaluronic acid was similarly visualized by a routine protocol. After semiquantitative assessment of staining, the results were compared with the pT and pN stages and the histological type. Survival was calculated by univariate and multivariate methods. RESULTS: Binding of galectin-1 and its expression tended to increase, whereas the parameters for galectin-3 decreased in advanced pT and pN stages at a statistically significant level. The number of positive cases was considerably smaller among the cases with small cell lung cancer than in the group with non-small-cell lung cancer, among which adenocarcinomas figured prominently with the exception of galectin-1 expression. Kaplan-Meier computations revealed that the survival rate of patients with galectin-3-binding or galectin-1-expressing tumors was significantly poorer than that of the negative cases. In the multivariate calculations of survival lymph node metastases (p < 0.0001), histological type (p = 0.003), galectin-3-binding capacity (p = 0.01), galectin-3 expression (p = 0.03) and pT status (p = 0.003) proved to be independent prognostic factors, not correlated with the pN stage. CONCLUSION: The expression and the capacity to bind the adhesion/growth regulatory galectin-3 is defined as an unfavorable prognostic factor not correlated with the pTN stage.

Aged↗

Comparative analysis of galectins in primary tumors and tumor metastasis in human pancreatic cancer.

Galectins are galactoside-binding proteins that exhibit an important function in tumor progression by promoting cancer cell invasion and metastasis formation. Using Northern blotting and Western blotting analysis, in situ hybridization (ISH), and immunohistochemistry (IHC), we studied galectin-1 and galectin-3 in tissue samples of 33 primary pancreatic cancers and in tumor metastases in comparison to 28 normal pancreases. Furthermore, the molecular findings were correlated with the clinical and histopathological parameters of the patients. Northern blotting and Western blotting analysis showed significantly higher galectin-1 and galectin-3 mRNA and protein levels in pancreatic cancer samples than in normal controls. For galectin-1, no ISH signals and immunoreactivity were observed in acinar or ductal cells in the normal pancreas and in pancreatic cancer cells, whereas fibroblasts and extracellular matrix cells around the cancer mass exhibited strong mRNA signals and immunoreactivity. Galectin-3 mRNA signals and immunoreactivity were strongly present in most pancreatic cancer cells, whereas in the normal controls only faint ISH and IHC signals were seen in some ductal cells. Metastatic pancreatic cancer cells exhibited moderate to strong galectin-3 immunoreactivity but were negative for galectin-1. No relationship between the galectin-1 and galectin-3 mRNA levels and the tumor stage or between the IHC staining score and the tumor stage was found. However, galectin-1 mRNA levels and the IHC staining score were significantly higher in poorly differentiated tumors compared with well/moderately differentiated tumors, whereas for galectin 3 no differences were found. The expression pattern of galectin-1 and galectin-3 in pancreatic cancer tissues indicates that galectin-1 plays a role in the desmoplastic reaction that occurrs around pancreatic cancer cells, whereas galectin-3 appears to be involved in cancer cell proliferation. High levels of galectin-3 in metastatic cancer cells suggest an impact on metastasis formation.

Adenocarcinoma↗

Expression of galectin-1 and galectin-3 in human fetal thyroid gland.

High levels of expression of galectin-1 and galectin-3, the beta-galactoside-binding proteins, have been recently described in malignant thyroid tumors but not in adenomas nor in normal thyroid tissue. However, there are no data about the expression of these galectins during fetal thyroid development. In this study we analyzed immunohistochemically the presence of galectin-1 and galectin-3 in human fetal thyroid glands (16-37 weeks of gestation). Weak to moderate cytoplasmic staining for galectin-1 was observed in follicular cells of all fetal thyroids. Galectin-3 could not be detected in thyroid follicular cells of any fetal thyroid investigated. Both galectins were detected in stromal tissue, but staining for galectin-1 was more intense. The absence of galectin-3 in thyroid cells during fetal development suggests that galectin-3 is expressed de novo during malignant transformation of thyroid epithelium, and that galectin-1 could be considered an oncofetal antigen. The results obtained indicated potential roles for galectin-1 and galectin-3 during the investigated period of human fetal thyroid gland development. Both galectins might participate in developmental processes regarding stromal fetal thyroid tissue organization, whereas galectin-1 might have a function in thyroid epithelium maturation.

Galectin 1↗

Human galectin-1, -2, and -4 induce surface exposure of phosphatidylserine in activated human neutrophils but not in activated T cells.

Cellular turnover is associated with exposure of surface phosphatidylserine (PS) in apoptotic cells, leading to their phagocytic recognition and removal. But recent studies indicate that surface PS exposure is not always associated with apoptosis. Here we show that several members of the human galectin family of glycan binding proteins (galectins-1, -2, and -4) induce PS exposure in a carbohydrate-dependent fashion in activated, but not resting, human neutrophils and in several leukocyte cell lines. PS exposure is not associated with apoptosis in activated neutrophils. The exposure of PS in cell lines treated with these galectins is sustained and does not affect cell viability. Unexpectedly, these galectins bind well to activated T lymphocytes, but do not induce either PS exposure or apoptosis, indicating that galectin's effects are cell specific. These results suggest novel immunoregulatory contribution of galectins in regulating leukocyte turnover independently of apoptosis.

Apoptosis↗

Sertoli cell expression of galectin-1 and -3 and accessible binding sites in normal human testis and Sertoli cell only-syndrome.

Galectins are vertebrate lectins interacting with beta-galactosides and derivates thereof such as blood group A, B and H determinants. The expression of gelectin-1 and -3 and galectin-specific binding sites by human Sertoli cells was analyzed in normal human testis and Sertoli cell only-syndrome (SCOS). Staining intensity was scored semiquantitatively on a 4-grade scale. Sertoli cells in normal testes displayed a moderate cytoplasmic and weak nuclear staining for galectin-1-specific binding sites. Galectin-3-specific binding sites were expressed in Sertoli cells less intensely than accessible ligands for galectin-1 (mean score 2.25 for galectin-1 and 1.50 for galectin-3). Germ cells were only weakly reactive. Tubular walls were negative for both classes of galectin-specific binding sites. In SCOS, galectin-1 binding was moderate to strong and more pronounced than galectin-3 binding by Sertoli cells (mean scores 4.00 and 2.25). Tubular walls were negative for galectin-staining. The ratio for galectin-1-/galectin-3-specific binding (staining score ratio) was 1.50 form normal testis and 1.78 for SCOS disclosing a relative increase of galectin-3 binding sites in the latter. Staining with galectin-1- and -3-specific antisera showed a strong cytoplasmic galectin-1 immunoreactivity in Sertoli cells of normal and SCOS testis (score 4.00 for both). Anti-galectin-3 did not stain Sertoli cells or germ cells in normal testis. Only Leydig cells were labeled (score 3.00). In SCOS a weak to moderate nuclear staining of Sertoli cells was noted (score 2.00). Galectin-3 expression and galectin-1-specific binding sites were found to be increased in Sertoli cells of SCOS. This modulation of reactivity can have implications for Sertoli cell interactions with galectin-reactive extracellular matrix components like laminin and for anti-apoptotic effects.

Adult↗

Expression of galectin-1 and -3 and of accessible binding sites during murine hair cycle.

Although protein-carbohydrate interactions are supposed to play key roles in cell adhesion, signalling and growth control. Their exact role in skin physiology has only recently been investigated. The endogenous lectins galectin-1 and galectin-3 have been identified in skin including hair follicles. Here, we analyzed the expression and distribution of these galectins and their binding sites in C57BL/6 mice during hair cycle. The expression of galectin-1 and galectin-3 binding sites was found to be predominantly hair cycle-dependent showing some overlapping to the expression of galectin-1 and -3. The outer root sheath (ORS) expressed galectin-1 binding sites during anagen IV to VI and in early catagen, whereas galectin-1 was expressed from early anagen to late catagen. The ORS expressed galectin-3 binding sites during catagen transition corresponding to a galectin-3 expression during anagen V and catagen. The innermost layer of the ORS expressed galectin-3 binding sites during anagen VI until catagen VIII, but galectin-3 during anagen III to IV and catagen. The inner root sheath (IRS) expressed galectin-3 binding sites only in anagen IV but missed expression of any of the two galectins. The matrix cells expressed galectin-3 binding sites in catagen II-III as well as galectin-3 during anagen V to catagen IV. The present study provides the first evidence for a cycle-related expression of both galectin-1 and -3 and their binding sites during murine hair cycle.

Animals↗

Human galectin-2: expression profiling by RT-PCR/immunohistochemistry and its introduction as a histochemical tool for ligand localization.

Sugar-encoded information of glyco-conjugates is translated into cellular responses by endogenous lectins. Galectins stand out against other lectin families due to their wide range of functions including cell adhesion, tissue invasion or growth regulation exerted at extracellular, membrane, cytoplasmic and nuclear sites. This remarkable versatility warrants close scrutiny of their emerging network, in this study with focus on homodimeric human galectin-2. We first detected presence of specific mRNA in various tissue types by processing post mortem and surgical specimens by RT-PCR protocols. Overlap of gene expression was noted with proto-type galectins-1 and -7 and also family members from the other two subgroups. To monitor expression on the level of protein a polyclonal anti-galectin-2 antibody was raised. Immunopositivity was semi-quantitatively assessed in sections of 209 human samples establishing an array both of normal tissues and samples with inflammation or benign/malignant growth. In general, positivity was predominantly epithelial without restriction of staining to certain tissue types, as fittingly indicated by our RT-PCR analysis. Staining was not limited to the cytoplasm but also included nuclear sites. To examine the suitability of the labeled lectin as a histochemical probe we biotinylated galectin-2 under activity-preserving conditions and introduced it to tissue profiling. Specific cytoplasmic staining proved the validity of the concept. Our results encourage systematic histopathologic studies by immuno- and lectin histochemistry, especially by adding galectin-2 as study object to galectin fingerprinting which has already yielded prognostic information on galectins-1, -3, -4 and -8 and hereby contributed to define functional overlap/divergence in this lectin family.

Antibodies↗

Human epidermal Langerhans cells are selectively recognized by galectin-3 but not by galectin-1.

Langerhans cells are dendritic antigen-presenting cells residing predominantly in the epidermis. Since endogenous galactoside-binding lectins with the jelly-roll motif (galectins) are known to trigger cellular responses, including mediator release, we investigated by lectin histochemistry the cells' capacity to bind two common members of this family, i.e. galectin-1 and -3. Actually, surrounding keratinocytes express a high level of galectin-3, and these cells can be considered as donors of this lectin to Langerhans cells. Employing biotinylated galectin-1 and -3, and concomitantly an antibody against CD1a as a second marker, to visualize the position of Langerhans cells in the human epidermis, the expression of galectin-3-reactive glycoligands in contrast to the lack of binding of galectin-1 was observed. Although the functional consequences of this selectivity are unclear, these results reveal an example for differential cellular reactivity towards two related endogenous lectins.

Adult↗

Glycophenotype of psoriatic skin.

Psoriasis is considered an auto-immune disease with consequential keratinocyte hyperproliferation resulting in specific architecture of psoriatic skin. This process is associated with phenotypical keratinocyte changes including an altered carbohydrate expression pattern studied by labelled plant lectins. Expression of endogenous lectins and their reactive glycoligands are differentiation-dependent in squamous epithelia including epidermis. However, no data are available on psoriatic skin, although this disease represents an important medical problem. We investigated the expression of galectin-1, -3, -7 and the presence of their glycoligands in the psoriatic skin and compared the results with the normal skin samples. The results were correlated to expression patterns of cytokeratin 10 and cytokeratin peptide 37 as markers of keratinocyte differentiation as well as to the expression of proliferation marker Ki67. Contrary to normal epidermis, the psoriatic epithelium expressed no galectin-3 and no glycoligands for galectin-1. Strong expression of galectin-3/galectin-3-reactive glycoligands in capillaries of psoriatic dermis represents one of the most important findings demonstrating the activation of endothelium in the course of the disease. The keratin expression pattern was not affected in psoriatic skin compared with normal epidermis. In conclusion, the altered galectin expression and binding pattern in psoriatic skin indicates the modified process of keratinocyte maturation in hyperactivated psoriatic epithelium. The enhanced expression of galectin-3/galectin-3-reactive glycoligands in dermal capillaries of psoriatic skin can be important for rearrangement of the capillary network and migration of inflammatory cells to psoriatic skin.

Biomarkers↗

A parallel association between differentiation and induction of galectin-1, and inhibition of galectin-3 by retinoic acid in mouse embryonal carcinoma F9 cells.

Soluble endogenous lactoside-binding lectins, galectins, have been implicated in cell adhesion, growth, differentiation, neoplastic transformation, and metastasis. Two major classes of these lectins, galectin-1 and galectin-3, are developmentally regulated. To explore the mechanisms by which the expression of the galectins is regulated and to examine their association with the differentiation processes induced by all-trans retinoic acid (RA), dibutyryl cyclic AMP (Bt2cAMP) and their combination, we used the murine embryonal carcinoma (EC) cell line F9 and its RA-resistant mutant, RA-3-10. RA induced endodermal differentiation and a concurrent induction of galectin-1 and its complementary glycoconjugates (laminin and lysosomal-associated membrane protein, LAMP) in the F9 wild-type (wt) line, but failed to induce differentiation and had no effects on or even reduced the expression of galectin-1, laminin, and LAMP in the RA-3-10 line. On the other hand, RA inhibited expression of galectin-3 in the wild-type line but had no effect on the RA-3-10 line. The galectin-1 gene is at least partially regulated at the transcriptional level. These results demonstrate a parallel association between differentiation and induction of galectin-1, and inhibition of galectin-3 in F9 cells by RA. The study suggests that a regulated expression of galectins and their complementary glycoconjugates is involved in the differentiation pathway induced by RA in F9 cells.

Animals↗

Comparison of gene expression of umbilical cord vein and bone marrow-derived mesenchymal stem cells.

Mesenchymal stem cells (MSCs) give origin to the marrow stromal environment that supports hematopoiesis. These cells present a wide range of differentiation potentials and a complex relationship with hematopoietic stem cells (HSCs) and endothelial cells. In addition to bone marrow (BM), MSCs can be obtained from other sites in the adult or the fetus. We isolate MSCs from the umbilical cord (UC) veins that are morphologically and immunophenotpically similar to MSCs obtained from the BM. In culture, these cells are capable of differentiating in vitro into adipocytes, osteoblasts, and condrocytes. The gene expression profiles of BM-MSCs and of UC-MSCs were compared by serial analysis of gene expression, then validated by reverse transcription polymerase chain reaction of selected genes. The two lineages shared almost all of the first thousand most expressed transcripts, including vimentin, galectin 1, osteonectin, collagens, transgelins, annexin A2, and MMP2. Nevertheless, a set of genes related to antimicrobial activity and to osteogenesis was more expressed in BM-MSCs, whereas higher expression in UC-MSCs was observed for genes that participate in pathways related to matrix remodeling via metalloproteinases and angiogenesis. Finally, cultured endothelial cells, CD34+ HSCs, MSCs, blood leukocytes, and bulk BM clustered together, separated from seven other normal nonhematopoietic tissues, on the basis of shared expressed genes. MSCs isolated from UC veins are functionally similar to BM-MSCs, but differentially expressed genes may reflect differences related to their sites of origin: BM-MSCs would be more committed to osteogenesis, whereas UC-MSCs would be more committed to angiogenesis.

Adenoviridae↗