Hyangsin Lee

Differential Expression Patterns of a Disintegrin and Metalloproteinase With Thrombospondin Motifs (ADAMTS) -1, -4, -5, and -14 in Human Placenta and Gestational Trophoblastic Diseases

CONTEXT The ability of intermediate trophoblasts to invade maternal tissue during placentation depends on how well they can degrade the extracellular matrix. Invasion into the extracellular matrix requires many complex proteases. A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) is a novel family of secreted metalloproteinases. The ADAMTS-1, -4, -5, and -14 subtypes are known to be expressed in human placenta, but little is understood about their expression patterns. OBJECTIVE To examine the expression patterns of ADAMTS-1, -4, -5, and -14 in specific human placenta cell types during gestation and in gestational trophoblastic diseases. DESIGN Placental tissues were obtained from 25 pregnant women and 21 cases of gestational trophoblastic diseases (10 early complete moles, 3 placental site trophoblastic tumors, 4 invasive moles, and 4 choriocarcinomas). The expression of the 4 ADAMTS was analyzed by immunohistochemistry. RESULTS ADAMTS-1, -4, -5, and -14 were differentially expressed by the human placenta throughout gestation in a time-specific and cell type-specific manner, as well as in gestational trophoblastic diseases. ADAMTS-1 showed gradually strong staining intensity in gestational trophoblastic diseases according to the invasive potential but showed consistent strong intensity throughout normal placenta. ADAMTS-4 and ADAMTS-5 exhibited higher and restricted expression in first-trimester intermediate trophoblasts. They also exhibited comparably strong expression in gestational trophoblastic diseases. However, ADAMTS-14 expression remained unchanged throughout gestation. CONCLUSIONS The restricted expression pattern of ADAMTS-4 and ADAMTS-5 and their increased expression in gestational trophoblastic diseases suggest that these 2 ADAMTS subtypes are associated with a biological phenotype of trophoblasts involved in human placentation and the development of gestational trophoblastic diseases.

Macrophage Heterogeneity of Culprit Coronary Plaques in Patients With Acute Myocardial Infarction or Stable Angina

We investigated the polarization states of macrophages in coronary atherectomy tissues retrieved from patients with acute myocardial infarction (AMI, n = 52) or stable angina pectoris (SAP, n = 22). The specimens were analyzed immunohistochemically using antibodies specific to CD11c (M1 marker), CD206 (M2 marker), and to markers of endothelial cells, macrophages, and smooth muscle cells. Baseline characteristics were similar in the 2 groups. The proportion of areas immunopositive for α smooth muscle actin was similar, but those positive for CD31 and CD68 were larger in the AMI group compared with the SAP group. In addition, AMI had significantly greater areas immunopositive for CD11c (P = .007) than did SAP, but CD206 (P = .102) positivity was not different in the 2 groups. In conclusion, M1 macrophage infiltration, not M2 macrophage infiltration, was increased in culprit plaques of patients with AMI. Macrophage heterogeneity may therefore be related to plaque instability.

Comparison of Differential Expression of P2Y12 Receptor in Culprit Coronary Plaques in Patients With Acute Myocardial Infarction Versus Stable Angina Pectoris

P2Y₁₂ receptor antagonists may have pleiotropic benefits. Little is known, however, about the expression of P2Y₁₂ receptors in coronary atherosclerotic plaques. We investigated the expression of P2Y₁₂ receptor in coronary atherectomy tissues retrieved from patients with acute myocardial infarction (AMI) or stable angina pectoris (SAP). Tissue specimens were collected from 35 patients with AMI and 19 with SAP who underwent directional coronary atherectomy. Specimens were analyzed immunohistochemically using antibodies specific to P2Y₁₂ receptor and to markers of endothelial cells, macrophages, and smooth muscle cells. The 2 groups had similar baseline clinical characteristics. Plaque types were more likely to be cellular in the AMI group. The proportion of areas immunopositive for α-smooth muscle actin was smaller but those positive for CD31 and CD68 were larger in the AMI than in the SAP group. In addition, the relative area immunopositive for P2Y₁₂ receptor was significantly larger for AMI than SAP (1.1 ± 0.9% vs 0.5 ± 0.4%, respectively, p < 0.001). P2Y₁₂ receptor positivity coincided with areas positive for CD31 and α-smooth muscle actin. In conclusion, P2Y₁₂ receptor is present in coronary atherosclerotic plaques and is increased in culprit plaques of patients with AMI. P2Y₁₂ receptor may play a role in plaque destabilization.

Autophagic Markers BECLIN 1 and LC3 are Associated with Prognosis of Multiple Myeloma.

Background/Aims: Autophagy is crucial for the survival and function of plasma cells including protection from toxic misfolded immunoglobulin and proper energy metabolism. Multiple myeloma (MM) is an indolent but eventually fatal neoplasm of plasma cells. Autophagy may play a critical role in the survival of MM cells and their response to chemotherapeutic agents. In this study, we correlated the expression of autophagy-related proteins with the prognosis of MM. Methods: In this retrospective cohort study, we examined the expression of the autophagic markers BECLIN 1 and microtubule-associated protein light chain 3 (LC3) in 89 cases of MM biopsied from 2001 to 2004 at the Asan Medical Center. The association of the expression scores of these markers with clinical outcomes was assessed. Results: Patients with strong immunoreactivity to BECLIN 1 or LC3 had a significantly better overall survival (OS) than patients with negative to moderate immunoreactivity (p = 0.036 and 0.018, respectively). This was also true for disease-specific survival (DSS; p = 0.051 and 0.043, respectively). In addition, LC3 immunostaining remained an independent factor impacting OS (p = 0.028) and DSS (p = 0.020) after multivariate analysis. Conclusions: The results of this study suggest that higher immunoreactivity for autophagic markers in MM is associated with superior patient survival.

Expression of CD99 in Multiple Myeloma: A Clinicopathologic and Immunohistochemical Study of 170 Cases.

Background Multiple myeloma (MM) is a heterogeneous and ultimately fatal disease. Risk stratification using prognostic biomarkers is crucial to individualize treatments. We sought to investigate the role of CD99, a transmembrane protein highly expressed in many hematopoietic cells including subpopulations of normal and neoplastic plasma cells, for MM risk stratification. Methods CD99 expression was measured in paraffin samples of bone marrow and extramedullary biopsies of 170 patients with MM. Patients were divided into those with high score (moderately and strongly positive) and low score (negative and weakly positive), with all staining being cytoplasmic and/or membranous. Results High anti-CD99 immunostaining was observed in 72 of 136 (52.9%) bone marrow biopsies and 24 of 87 (27.6%) extramedullary biopsies in MM. High CD99 expression of extramedullary specimens was associated with significantly longer overall survival (OS; p=.016). High CD99 expression of extramedullary specimens was also associated with better prognosis in the nonautologous stem cell transplantation group of MM patients (p=.044). In multivariate analysis, International Staging System stage was an independent prognostic factor, whereas CD99 expression was no longer statistically significant. Conclusions Expression of CD99 in extramedullary specimens was correlated with longer OS, suggesting that CD99 may be a helpful immunohistochemical marker for risk stratification.

Comparison of ADAMTS-1, -4 and -5 expression in culprit plaques between acute myocardial infarction and stable angina

Background ADAMTS (a disintegrin and metalloproteinase with thrombospondin type 1 motifs) proteases might contribute to plaque destabilisation by weakening the fibrous cap. However, little is known about the expression of ADAMTS proteases in coronary atherosclerotic plaques. Objective To examine the expression of ADAMTS proteases in coronary atherectomy samples obtained from patients with acute myocardial infarction (AMI) or stable angina. Methods Atherectomy specimens were obtained from 34 patients with AMI (n=23) or stable angina (n=11) who underwent directional coronary atherectomy. The specimens were stained with H&E and analysed immunohistochemically using antibodies specific to ADAMTS-1, -4 and -5; versican cleavage products; and markers for endothelial cells, macrophages and smooth muscle cells. Results Baseline characteristics were similar between the two groups. The proportion of CD31 and CD68 immunopositive areas did not differ between the two groups, but the area immunopositive for smooth muscle α-actin was smaller in the AMI group. The relative area immunopositive for ADAMTS-1 in AMI (1.04% (IQR 0.59–2.09%)) was significantly greater than that in stable angina (0.24% (0.15–0.39%); p<0.001). In contrast, the proportion of areas immunopositive for ADAMTS-4 or -5 was similar in the two groups. Areas that stained for ADAMTS-1 largely overlapped with those positive for CD68 and versican cleavage products. The areas immunopositive for ADAMTS-1 were significantly correlated with CD68 immunostained areas (r=0.50, p=0.003). Conclusions ADAMTS-1, -4 and -5 were present in human coronary atherosclerotic plaques, and ADATS-1 was more strongly expressed in AMI plaques than in stable plaques. ADAMTS-1 may play a role in plaque instability.

Comparison of intravascular ultrasound and histological findings in culprit coronary plaques between ST-segment elevation and non-ST-segment elevation myocardial infarction.

It remains uncertain whether the histology of culprit coronary plaques differs between ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI). We compared intravascular ultrasound (IVUS) and histologic findings in coronary culprit plaques among patients presenting with STEMI and NSTEMI. Atherectomy specimens were obtained from 96 patients, 70 with STEMI and 26 with NSTEMI, who underwent directional coronary atherectomy for de novo coronary artery lesions. IVUS examinations were performed before directional coronary atherectomy. IVUS and histologic data were analyzed. Clinical characteristics were largely similar between the 2 groups; however, normal antegrade flow before angioplasty was less frequently observed in patients with STEMI than those with NSTEMI. Plaque rupture was more common on the proximal side of the minimal lumen site. There were no differences in vessel area, lumen area, calcification, plaque burden, or remodelling index at the reference and culprit sites. However, the arc of the ruptured cavity was significantly greater in patients with STEMI than those with NSTEMI (69.4 ± 27.9° vs 51.8 ± 20.0°, respectively, p = 0.008). The proportion of atheroma, fibrocellular, and thrombus areas was not different between the 2 groups. Similarly, the relative areas immunopositive for CD31, smooth muscle α-actin, and CD68 were similar in the 2 groups. In conclusion, coronary culprit lesions in patients with STEMI show more severe plaque rupture with similar histologic features than those in patients with NSTEMI, supporting the idea that a large plaque rupture is more likely in STEMI patients.

Expression of stanniocalcin-1 in culprit coronary plaques of patients with acute myocardial infarction or stable angina

Background Stanniocalcin-1 (STC1) is involved in fundamental biological processes such as angiogenesis, inflammation and wound healing, but little is known about its expression in human coronary atherosclerotic plaques or its relationship to plaque instability. Objective STC1 expression was examined in the culprit coronary plaques of 70 patients with acute myocardial infarction (AMI; n=49) or stable angina (n=21) who underwent directional coronary atherectomy. Methods The specimens were stained with H&E, STC1-specific antibodies, and endothelial cells, macrophages and smooth muscle cell markers. Results The baseline characteristics of the two groups of patients were largely similar. CD31-immunopositive and CD68-immunopositive areas, indicative of the presence of endothelial cells and macrophages, respectively, were proportionately larger while areas immunopositive for α-actin, as a smooth muscle cell marker, were proportionately smaller in the AMI group than in the stable angina group. The proportion of STC1-immunopositive areas was significantly greater in the AMI group than in the stable angina group (20.0% (8.2–29.0%) vs 8.8% (3.9–19.4%), p=0.022). Areas positive for STC1 were independently correlated with those immunopositive for CD31 (r=0.42, p<0.001) and CD68 (r=0.40, p<0.001). STC1 immunoreactivity co-localised with CD31-immunopositive and CD68-immunopositive cells. Conclusions STC1 is differentially expressed in the culprit coronary plaques of patients with AMI versus those with stable angina. STC1 may play a role in plaque instability.

An effective immune-monitoring protocol based on gene expression profiles in the peripheral T-cell fraction reactive to graft antigens.

Background The ability to induce tolerance, or at least minimize the need for immunosuppressive therapy, is a high priority in organ transplantation. Accomplishing this goal requires a novel method for determining when a patient has become tolerant to or is rejecting their graft. Here, we sought to develop an efficient monitoring protocol based on gene expression profiles of recipient T cells in murine skin and islet allograft models. Methods Unlike previous studies, here, gene expression analysis was focused on donor antigen-reactive T cells, which were prepared by collecting CD69+ T cells from cocultures of recipient peripheral T cells and donor antigen-presenting cells. Candidate tolerance and rejection biomarker genes were selected from a CD69+ T-cell microarray analysis, and their expression levels were measured in the recipient CD69+ T-cell fraction using quantitative reverse transcription polymerase chain reaction. Results Our new monitoring protocol was capable of precisely detecting the immune status of recipients relative to their graft regardless of the organ received, whether they were taking immunosuppressive drugs, or different strains of origin. Conclusions Gene expression analysis focusing on recipient CD69+ T cells as the donor antigen-reactive T-cell population could be used as an effective and sensitive method for monitoring transplant patients.

Engagement of CD99 Reduces AP-1 Activity by Inducing BATF in the Human Multiple Myeloma Cell Line RPMI8226.

CD99 signaling is crucial to a diverse range of biological functions including survival and proliferation. CD99 engagement is reported to augment activator protein-1 (AP-1) activity through mitogen-activated protein (MAP) kinase pathways in a T-lymphoblastic lymphoma cell line Jurkat and in breast cancer cell lines. In this study, we report that CD99 differentially regulated AP-1 activity in the human myeloma cell line RPMI8226. CD99 was highly expressed and the CD99 engagement led to activation of the MAP kinases, but suppressed AP-1 activity by inducing the expression of basic leucine zipper transcription factor, ATF-like (BATF), a negative regulator of AP-1 in RPMI8226 cells. By contrast, engagement of CD99 enhanced AP-1 activity and did not change the BATF expression in Jurkat cells. CD99 engagement reduced the proliferation of RPMI8226 cells and expression of cyclin 1 and 3. Overall, these results suggest novel CD99 functions in RPMI8226 cells.