Temporo-spatial distribution of stem cell markers CD146 and p75NTR during odontogenesis in mice

Abstract Mesenchymal and epithelial stem cells were identified in dental tissues; however, knowledge about the odontogenic stem cells is limited, and there are some questions regarding their temporo-spatial dynamics in tooth development. Objective Our study aimed to analyze the expression of the stem cell markers CD146 and p75NTR during the different stages of odontogenesis. Methodology The groups consisted of 13.5, 15.5, 17.5 days old embryos, and 14 days postnatal BALB/c mice. The expression of CD146 and p75NTR was evaluated by immunohistochemistry. Results Our results showed that positive cells for both markers were present in all stages of tooth development, and the number of positive cells increased with the progression of this process. Cells of epithelial and ectomesenchymal origin were positive for CD146, and the expression of p75NTR was mainly detected in the dental papilla and dental follicle. In the postnatal group, dental pulp cells were positive for CD146, and the reduced enamel epithelium and the oral mucosa epithelium showed immunostaining for p75NTR. Conclusions These results suggest that the staining pattern of CD146 and p75NTR underwent temporal and spatial changes during odontogenesis and both markers were expressed by epithelial and mesenchymal cell types, which is relevant due to the significance of the epithelial-ectomesenchymal interactions in tooth development.

Comparison of the properties of CD146 positive and CD146 negative subpopulations of stem cells from human exfoliated deciduous teeth / 北京大学学报(医学版)

OBJECTIVE@#Stem cells from human exfoliated teeth (SHED) were sorted by magnetically activated cell sorting (MACS) technique to obtain the CD146 positive and negative cell subpopulation. Then the biological characteristics of these subpopulations were compared to explore their specific application potential in tissue engineering.@*METHODS@#In this study, freshly extracted deciduous teeth without any caries or dental pulp disease were obtained. SHED was isolated using enzyme digestion method and then sorted by MACS, CD146 positive cells and CD146 negative cells were obtained after cell sorting. The biological characteristics of the unsorted mixed cells, CD146 positive subpopulation and CD146 negative subpopulation were compared. The proliferation ability was detected through cell counting kit-8 (CCK-8) and colony-forming unit (CFU). After osteogenic induction, alizarin red staining was performed and the gene expression of osteogenic related markers was detected by quantitative real-time polymerase chain reaction(qPCR). After adipogenic induction, oil-red O staining was performed and the gene expression of adipogenic related markers was detected. After neurogenic differentiation induction, the expression of neural markers was detected by immunofluorescence and the gene expression of neural markers was detected by qPCR.@*RESULTS@#SHED of the fifth passage was sorted by MACS. And the CD146 positive cell subpopulation and CD146 negative cell subpopulation were obtained. CCK8 assay showed that the proliferative tendency of the three cell groups was consistent, but the proliferation potential of CD146 positive and negative cell subpopulations was significantly lower than that of the unsorted cells. The colony forming rates of the unsorted mixed cell group, CD146 positive and negative populations were 28.6%±3%,17.1%±2.3% and 27.5%±2.5%, respectively. After 21 days of osteogenic induction, alizarin red staining and qPCR showed that the CD146 positive cell population had more mineralized nodule formation and expressed higher level of osteogenic related genes compared with the other two groups. After 21 days of adipogenic induction, oil red O staining and qPCR results showed that the CD146 negative subpopulation produced more lipid droplets and the expression of lipid related genes increased more significantly. After 14 days of neural induction, cell immunofluorescence and qPCR results showed that the unsorted mixed cell group and CD146 positive subpopulation expressed glial cell marker, and the expressions of neural precursor cells and neuronal marker increased significantly in negative subpopulation.@*CONCLUSION@#The unsorted mixed cells showed better proliferative potential than CD146 positive and negative subpopulations. The CD146 positive subpopulation was most potent in osteogenic differentiation; it was more suitable for bone tissue engineering. The CD146 negative cells had stronger adipogenic differentiation potential than the other two cell groups; different subpopulations differed in neural differentiation.

Plasma Levels of Soluble CD146 Reflect the Severity of Pulmonary Congestion Better Than Brain Natriuretic Peptide in Acute Coronary Syndrome

BACKGROUND: Acute heart failure negatively affects short-term outcomes of patients with acute coronary syndrome (ACS). Therefore, reliable and non-invasive assessment of pulmonary congestion is needed to select patients requiring more intensive monitoring and therapy. Since plasma levels of natriuretic peptides are influenced by myocardial ischemia, they might not reliably reflect congestion in the context of ACS. The novel endothelial biomarker, soluble CD146 (sCD146), presents discriminative power for detecting the cardiac origin of acute dyspnea similar to that of natriuretic peptides and is associated with systemic congestion. We evaluated the performance of sCD146 for the assessment of pulmonary congestion in the early phase of ACS. METHODS: One thousand twenty-one consecutive patients with ACS were prospectively enrolled. Plasma levels of sCD146, brain natriuretic peptide (BNP), and high-sensitive troponin T were measured within 24 hr after the onset of chest pain. Pulmonary congestion on chest radiography was determined and classified in three groups according to the degree of congestion. RESULTS: Nine hundred twenty-seven patients with ACS were analyzed. Ninety-two (10%) patients showed signs of pulmonary edema on chest radiography. Plasma levels of sCD146 reflected the radiological severity of pulmonary congestion. Higher plasma levels of sCD146 were associated with the worse degree of pulmonary congestion. In contrast to BNP, sCD146 levels were not affected by the level of troponin T. CONCLUSIONS: The novel endothelial biomarker, sCD146, correlates with radiological severity of pulmonary congestion in the early phase of ACS and, in contrast to BNP, is not affected by the amount of myocardial cell necrosis.

Single CD271 marker isolates mesenchymal stem cells from human dental pulp / 国际口腔科学杂志·英文版

Mesenchymal stem cells (MSCs) are a promising tool in regenerative medicine due to their capacity to differentiate into multiple lineages. In addition to MSCs isolated from bone marrow (BMSCs), adult MSCs are isolated from craniofacial tissues including dental pulp tissues (DPs) using various stem cell surface markers. However, there has been a lack of consensus on a set of surface makers that are reproducibly effective at isolating putative multipotent dental mesenchymal stem cells (DMSCs). In this study, we used different combinations of surface markers (CD51/CD140α, CD271, and STRO-1/CD146) to isolate homogeneous populations of DMSCs from heterogeneous dental pulp cells (DPCs) obtained from DP and compared their capacity to undergo multilineage differentiation. Fluorescence-activated cell sorting revealed that 27.3% of DPCs were CD51(+)/CD140α(+), 10.6% were CD271(+), and 0.3% were STRO-1(+)/CD146(+). Under odontogenic conditions, all three subsets of isolated DMSCs exhibited differentiation capacity into odontogenic lineages. Among these isolated subsets of DMSCs, CD271(+) DMSCs demonstrated the greatest odontogenic potential. While all three combinations of surface markers in this study successfully isolated DMSCs from DPCs, the single CD271 marker presents the most effective stem cell surface marker for identification of DMSCs with high odontogenic potential. Isolated CD271(+) DMSCs could potentially be utilized for future clinical applications in dentistry and regenerative medicine.

Characterization of the osteogenic potential of mesenchymal stem cells from human periodontal ligament based on cell surface markers / 国际口腔科学杂志·英文版

Mesenchymal stem cell (MSC)-mediated therapy has been shown to be clinically effective in regenerating tissue defects. For improved regenerative therapy, it is critical to isolate homogenous populations of MSCs with high capacity to differentiate into appropriate tissues. The utilization of stem cell surface antigens provides a means to identify MSCs from various tissues. However, few surface markers that consistently isolate highly regenerative MSCs have been validated, making it challenging for routine clinical applications and making it all the more imperative to identify reliable surface markers. In this study, we used three surface marker combinations: CD51/CD140α, CD271, and STRO-1/CD146 for the isolation of homogenous populations of dental mesenchymal stem cells (DMSCs) from heterogeneous periodontal ligament cells (PDLCs). Fluorescence-activated cell sorting analysis revealed that 24% of PDLCs were CD51(+)/CD140α(+), 0.8% were CD271(+), and 2.4% were STRO-1(+)/CD146(+). Sorted cell populations were further assessed for their multipotent properties by inducing osteogenic and chondrogenic differentiation. All three subsets of isolated DMSCs exhibited differentiation capacity into osteogenic and chondrogenic lineages but with varying degrees. CD271(+) DMSCs demonstrated the greatest osteogenic potential with strong induction of osteogenic markers such as DLX5, RUNX2, and BGLAP. Our study provides evidence that surface marker combinations used in this study are sufficient markers for the isolation of DMSCs from PDLCs. These results provide important insight into using specific surface markers for identifying homogenous populations of DMSCs for their improved utilization in regenerative medicine.

Impaired tumor angiogenesis and VEGF-induced pathway in endothelial CD146 knockout mice

CD146 is a newly identified endothelial biomarker that has been implicated in angiogenesis. Though in vitro angiogenic function of CD146 has been extensively reported, in vivo evidence is still lacking. To address this issue, we generated endothelial-specific CD146 knockout (CD146(EC-KO)) mice using the Tg(Tek-cre) system. Surprisingly, these mice did not exhibit any apparent morphological defects in the development of normal retinal vasculature. To evaluate the role of CD146 in pathological angiogenesis, a xenograft tumor model was used. We found that both tumor volume and vascular density were significantly lower in CD146(EC-KO) mice when compared to WT littermates. Additionally, the ability for sprouting, migration and tube formation in response to VEGF treatment was impaired in endothelial cells (ECs) of CD146(EC-KO) mice. Mechanistic studies further confirmed that VEGF-induced VEGFR-2 phosphorylation and AKT/p38 MAPKs/NF-κB activation were inhibited in these CD146-null ECs, which might present the underlying cause for the observed inhibition of tumor angiogenesis in CD146(EC-KO) mice. These results suggest that CD146 plays a redundant role in physiological angiogenic processes, but becomes essential during pathological angiogenesis as observed in tumorigenesis.

Isolation and identification of Beagle dog dental pulp stem cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To identify the existence of the dental pulp stem cells in Beagle's pulp tissue by using the same methods of isolating and culturing the human dental pulp stem cells.</p><p><b>METHODS</b>Pulp tissue was extirpated from the crown and root of the Beagle's healthy permanent tooth, and digested by dispase for cell culture. Classical identification methods of mesenchymal stem cells including observation of biological characteristics, capacity of multilineage differentiation, and expression of specific markers associated with mesenchymal stem cells were applied to verify the existence of Beagle's dental pulp stem cells.</p><p><b>RESULTS</b>A clonogenic, rapidly proliferative population of cells were isolated from Beagle' pulp tissue. Under the same culture condition, the Beagle's dental pulp stem cells had a significant higher colony-forming unit-fibroblast (CFU-F) formation rate (150 colony/10(4) cells) than the dental pulp cells derived from the human pulp tissue (60 colony/10(4) cells). These cells also had the multilineage differentiation ability. They could be induced to form mineralized nodules, lipid droplets and chondrocytes. Furthermore these cells expressed the mesenchymal stem cell markers including STRO-1, CD146, alkaline phosphatase, nestin, vimentin and cytokeratin-18.</p><p><b>CONCLUSIONS</b>There are dental pulp stem cells in the Beagle's pulp tissue.</p>

Comparison of the effects of recombinant human endostatin and docetaxel on human umbilical vein endothelial cells in different growth states / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recombinant human endostatin (rh-endostatin, Endostar) has been proved to be an inhibitor of angiogenesis. Docetaxel has been also considered as a common chemotherapeutic agent with inhibition of angiogenesis of malignancies. However, their function has been seldom compared and a best synergism protocol is not determined. This study aimed to compare the effects of two drugs, investigate their combined impact on human umbilical vein endothelial cells (HUVECs), a molecular basis and find ideal protocols to inhibit endothelial cell proliferation.</p><p><b>METHODS</b>HUVECs on confluent growth or activated by vascular endothelial growth factor (VEGF) were treated by rh-endostatin or/and docetaxel at respective gradient concentration in following operations as cell proliferation determined by MTT assay, cell cycle distribution, apoptosis and markers of CD146, CD62E and CD105 detected by flow cytometery, the structure of the channel formed by HUVECs measured by tube formation count.</p><p><b>RESULTS</b>Rh-endostatin exhibited time dependent inhibition of proliferation while docetaxel showed both time and dose dependent inhibition. HUVECs accumulated in G(0)-G(1) with decreased numbers of cells in G(2) after a single treatment of rh-endostatin or that followed by docetaxel treatment. Cells accumulated in G(2) after both a single docetaxel and simultaneous administration. Both the number of cells in G(0)-G(1) and apoptotic cells were increased by docetaxel followed by rh-endostatin treatment. The number of non-apoptotic cells at G(0)-G(1) was increased by first administering rh-endostatin then docetaxel. Sequential treatment of docetaxel followed by rh-endostatin resulted in the greatest increase in apoptosis (34.7%) and the second highest apoptosis was seen with simultaneous administration (18.2%). Expression of CD146 and CD105 on confluent HUVECs was reduced at certain doses of rh-endostatin and/or docetaxel. However, rh-endostatin reduced CD105 without any apparent impact on either CD146 or CD62E expression, whereas these markers were down-regulated by docetaxel after pre-activation by VEGF. Rh-endostatin treatment maintained tube-like structures for a limited time. In contrast, docetaxel swiftly reduced tube formation. Simultaneous treatment, or docetaxel followed by rh-endostatin, exhibited a stronger inhibition on tube formation than either agent alone.</p><p><b>CONCLUSIONS</b>Both rh-endostatin and docetaxel can inhibit HUVEC proliferation while the high apoptotic rate after combined administration was probably owing to different sequent administration by docetaxel followed by rh-endostatin or simultaneous treatment. Both proliferation and adhesion molecules on HUVECs of confluent growth are down-regulated by the two drugs. The rh-endostatin decreased proliferation markers, but only slightly modified adhesion molecules, while both markers were down-regulated by docetaxel on HUVECs activated by VEGF. Rh-endostatin could maintain adhesion of HUVECs at first then induce cells apoptosis to damage tube formation. We hypothesize that it could lead to vascular normalization in short time. In contrast, docetaxel can suppress HUVEC proliferation, adhesion, and reduced tube formation swiftly due to its cytotoxicity. Combined treatments can induce a synergistic inhibition of tube formation.</p>

Leukemic stromal hematopoietic microenvironment negatively regulates the normal hematopoiesis in mouse model of leukemia / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>Leukemic microenvironment has a major role in the progression of leukemia. Leukemic cells can induce reversible changes in microenvironmental components, especially the stromal function which results in improved growth conditions for maintaining the malignant leukemic cells. This study aimed to investigate the survival advantage of leukemic cells over normal hematopoietic cells in stromal microenvironment in long term.</p><p><b>METHODS</b>The mice were injected intraperitoneally with N-N' ethylnitrosourea (ENU) to induce leukemia; the mice received injection of normal saline were used as control. At 180 days after ENU induction, the mice were killed and the bone marrows were cultured for 19 days. Colony-forming assays were used to analyze the formation of various cell colonies. The expression of Sca-1, CD146, VEGFR2, CD95, pStat3, pStat5, and Bcl-xL in marrow cells were detected by flow cytometry.</p><p><b>RESULTS</b>Long-term leukemic bone marrow culture showed abnormal elongated stromal fibroblasts with almost absence of normal hematopoietic cells. Adherent cell colonies were increased, but CFU-F and other hematopoietic cell colonies were significantly decreased in leukemia group (P<0.001). Primitive progenitor-specific Sca-1 receptor expression was decreased with subsequent increased expression of CD146 and VEGFR-2 in leukemic bone marrow cells. Decreased Fas antigen expression with increased intracellular pStat3, pStat5 and Bcl-xL proteins were observed in leukemic bone marrow cells.</p><p><b>CONCLUSIONS</b>Stromal microenvironment shows altered morphology and decreased maturation in leukemia. Effective progenitor cells are decreased in leukemia with increased leukemia-specific cell population. Leukemic microenvironment plays a role in promoting and maintaining the leukemic cell proliferation and survivability in long term.</p>

Biological effect of endostatin on transplanted human lung adenocarcinoma Calu-6 tumor in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To assess the effect of endostatin on growth and neoplastic angiogenesis in transplanted human lung adenocarcinoma Calu-6 tumor in nude mice.</p><p><b>METHODS</b>To treat Calu-6 tumor-bearing mice with endostatin at different doses, and to record the changes of the tumor size. The expressions of survivin, VEGF, COX-2 and MVD in tumor tissue were examined by immunohistochemistry staining, circulating endothelial cells (CECs) by flow cytometry and mRNA of CD146 and CD105 by RT-PCR and real-time PCR.</p><p><b>RESULTS</b>After endostatin treatment, the tumor size was conspicuously shrunk, and the expressions of survivin, COX-2 and VEGF protein and MVD in tumor tissue decreased concomitantly with the significant difference between each of trial groups and control group (all P < 0.05). Both CECs and mRNA of CD146 and CD105 diminished remarkably. A positive correlation between both exhibition and change of amount of activated CECs and survivin, VEGF expression and MVD count in tumor tissue was found.</p><p><b>CONCLUSION</b>Endostatin can decrease the expression of survivin, COX-2, VEGF and MVD, and to inhibit the growth of transplanted tumor. Activated CECs may probably serve as an ideal marker to predict the efficacy and prognosis of anti-angiogenesis therapy.</p>

Clinicopathologic study of tumors of intermediate trophoblasts / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features and immunophenotype of placental site trophoblastic tumor (PSTT) and epithelioid trophoblastic tumor (ETT).</p><p><b>METHODS</b>During the period from 1959 to 2005, a total of 1012 cases of gestational trophoblastic disease were diagnosed in Beijing Obstetrics and Gynecology Hospital. Six cases of PSTT and a case of ETT were retrieved from the archives of Beijing Obstetrics and Gynecology Hospital. Immunohistochemical study for cytokeratin 18, human chorionic gonadotropin (hCG), human placental lactogen (hPL), Mel-CAM (CD146), placental-like alkaline phosphatase (PLAP), epithelial membrane antigen (EMA), inhibin-alpha and proliferative cell nuclear antigen (PCNA) were performed. The morphologic features and immunohistochemical findings were compared with those of the controlled group which consisted of 20 cases of early gestational villi with decidua basalis and 20 cases of hydatidiform moles with implantation site.</p><p><b>RESULTS</b>The mean age of patients with PSTT was 32.4, while the age of patients with ETT was 36. Major clinical findings included irregular vaginal bleeding and amenorrhea. Preoperative serum hCG level varied from normal to moderately elevated. Serum testosterone level was raised in 1 case. Uterine curettage could achieve an accurate pathologic diagnosis in 60% of cases. ETT involved mainly the lower uterine segment and endocervix. Histologically, PSTT cells permeated between the myometrial fibers and vessels either individually or connecting in cords or sheets in a manner reminiscent of the implantation site reaction. ETT composed of a relatively uniform population of mononuclear trophoblastic cells, clumping together in nests as the cell islets associating with eosinophilic, fibrillary and hyaline material and necrotic debris, forming a "geographic map" like pattern. Immunohistochemical study for hPL, hCG, Mel-CAM (CD146) and PLAP was most helpful for the differential diagnosis. The duration of follow-up varied from 14 months to 19 years. One case of PSTT developed metastasis in pancreas, 5 months after the operation. The remaining patients survived without tumor recurrence.</p><p><b>CONCLUSIONS</b>PSTT is a tumor of implantation site intermediate trophoblasts while ETT differentiates towards chorionic-type intermediate trophoblasts. The different pathologic features and immunophenotype observed were closely related with the difference in tumor cell differentiation. An accurate pathologic diagnosis of the uterine curettage material is important for the clinical management. According to the limited follow-up data available, the clinical behavior of ETT is seemed similar to that of PSTT.</p>

Apoptosis and arterial thrombosis: expression of CD31 and CD146 in recent and old thrombotic disorders

Apoptosis [programmed cell death] of vascular lining endothelium is one of the causes of increased thrombogenicity. The Luminal release of apoptotic endothelium-derived microparticles can cause activation of tissue factor [TF], the most potent known inhibitor of the blood clotting system. The study was carried out at Al-Azhar University Hospitals on 70 cases of arterial thrombosis above the age of 25 years: Group 1: consisted of 15 apparently healthy subjects as a control group. Group 11: including 32 patients of recent thrombosis; 13 with cerebral infarction, 12 with acute myocardial in farction [MI] and 7 patients with peripheral arterial thrombosis. Group 111: including 38 patients with old thrombosis; 12 with cerebral infarction, 18 with MI and 8 patients with old peripheral arterial thrombosis. Endothelial-derived CD31 and CD146 were statistically higher in patients with recent and old arterial thrombosis than controls [p<0.005, p< 0.01] respectively and statistically higher in old than in recent arterial thrombosis [p<0.05]. Hypertension DM, smoking and lipid profile have no significant effect on CD31 and CD146. Finally, endothelial microparticle detection among cases of arterial thrombosis may indicate the persistence of the danger of re-thrombosis. Patients with acute and chronic ischemia have altered response of endothelial cells. It remains to be determined whether the reduction of the increased activity of CD31 and CD146 could provide an effective rationale for acute arterial thrombosis therapy