Expression of Cyclophilin A in Coronary Artery Plaque with Intraplaque Hemorrhage Is More Frequent in Deceased Patients Who Had Impaired Kidney Function.

Patients with impaired kidney function have a high frequency of intraplaque hemorrhage (IPH) in their coronary arteries. Levels of cyclophilin A (CyPA), an indirect matrix metalloproteinase inducer, are increased in deceased patients who had impaired kidney function. In this study, we have examined the relationship between IPH and CyPA.We examined 47 samples of coronary plaque from 27 cadavers with coronary stenosis. These sections, all with > 50% coronary stenosis, were stained with an antibody against CyPA and the expression of CyPA was semi-quantified. Cadavers and plaques were classified into one of two groups depending on the presence or absence of IPH. IPH was defined as the presence of red blood cells stained with hematoxylin and eosin (HE) indicative of overt acute hemorrhage.In an individual analysis, estimation of glomerular filtration rate (eGFR) in the IPH group was significantly lower than that in the non-IPH group (P = 0.002). In a histological analysis, the percentage of stained area of CyPA in the IPH group was significantly higher than that in the non-IPH group (P < 0.0001).IPH was associated with a significantly higher expression of CyPA in this study. In addition, patients with IPH in their coronary arteries had significantly impaired kidney function.

Feasibility of optical coronary tomography in quantitative measurement of coronary arteries with lipid-rich plaque.

BACKGROUND: The aim of the present study was to evaluate the feasibility of optical coherence tomography (OCT) for measurement of vessel area in coronary arteries with lipid-rich plaque as compared with intravascular ultrasound (IVUS). METHODS AND RESULTS: We investigated 80 coronary artery segments with lipid-rich plaque on OCT and non-attenuated plaque on IVUS. According to the lipid arc on OCT, the plaques were classified into 4 groups: group 1, lipid arc ≤90°; group 2, 90°270°. Vessel circular arcs that could not be identified due to OCT signal attenuation were interpolated using an approximating algorithm. OCT-measured vessel area was well-correlated with IVUS-measured vessel area (R=0.834, P<0.001). On Bland-Altman plot, there was a good agreement between OCT-measured vessel area and IVUS-measured vessel area, although mean difference and limits of agreement increased with increase of lipid arc (mean difference in groups 1-4: -0.21, -0.31, -1.02, and -2.13 mm(2); lower limit: -1.49, -3.22, -5.24, and -9.25 mm(2); and upper limit: 1.07, 2.60, 3.20, and 4.99 mm(2)). Intra-observer (R=0.97-0.99, P<0.001) and inter-observer (R=0.97-0.99, P<0.001) reproducibility for OCT measurement of vessel area was excellent. CONCLUSIONS: Like IVUS, OCT can be used to measure vessel area in coronary arteries with lipid-rich plaque.

The loss of Trps1 suppresses ureteric bud branching because of the activation of TGF-ß signaling.

In a previous study, we demonstrated that Trps1-deficient (KO) mice show an expanded renal interstitium compared to wild-type (WT) mice because the loss of Trps1 affects the mesenchymal-epithelial transition (MET) in the cap mesenchyme and ureteric bud (UB) branching. Although we previously elucidated the mechanism underlying the impact of Trps1 on the MET, how Trps1 is involved in UB branching remains unknown. In the present study, we unveil the molecular mechanisms by which the loss of Trps1 suppresses UB branching. When we compared gene expression patterns via DNA microarray analysis using cultured ureteric buds isolated from E11.5 kidneys of WT and KO embryos, we found aberrant expression of genes associated with the transforming growth factor (TGF)-ß/Smad3 signaling pathway in the KO UBs. Western blot and immunohistochemistry analyses showed increased levels of Rb1cc1, Arkadia1, and phosphorylated Smad3 and decreased levels of Smurf2, Smad7, and c-Ski in the KO embryonic kidneys. In addition, TUNEL staining and immunohistochemical detection of PCNA revealed that the apoptosis of UB cells was upregulated and, conversely, that cell proliferation was suppressed. Finally, we demonstrated that the suppression of UB branching in the KO UBs was restored via the exogenous addition of the Smad3 inhibitor SIS3, whereas the addition of TGF-ß1 accelerated the suppression of UB branching in organ cultures of both isolated UBs and whole embryonic kidneys. Considering these results, we conclude that UB branching is suppressed through increased activation of the TGF-ß/Smad3 signaling pathway when Trps1 is lost.

Smad3 plays an inhibitory role in phosphate-induced vascular smooth muscle cell calcification.

Arterial medial calcification is a major complication in patients with chronic kidney disease and diabetes. It has been hypothesized that a high concentration of inorganic phosphate (Pi) induces calcification in vascular smooth muscle cells (vSMCs). However, the role of transforming growth factor-ß (TGF-ß)/Smad3 signaling in Pi-induced vascular calcification remains controversial. The aim of this study was to investigate the possible involvement of Smad3 in Pi-induced vascular calcification. We compared the degree of Pi-induced vSMC calcification between vSMCs isolated from wild-type (Smad3(+/+)) and Smad3-deficient (Smad3(-/-)) mice. We found that vSMCs from Smad3(+/+) mice had less calcium (Ca) than those from Smad3(-/-) mice when they were exposed to high concentrations of Pi and Ca (Pi+Ca). The phosphorylation of Smad3 was induced in Smad3(+/+) vSMCs by exposure to Pi+Ca. The concentration of extracellular pyrophosphate (ePPi) was lower in Smad3(-/-) vSMCs than in Smad3(+/+) vSMCs and was significantly increased in Smad3(+/+) vSMCs by treatment with TGF-ß1. Also, the addition of a small amount of PPi to culture medium significantly decreased the deposition of Ca in both Smad3(+/+) and Smad3(-/-) vSMCs. Ectonucleotide phosphatase/phosphodiesterase1 (Enpp1) was decreased at the mRNA, protein, and enzymatic activity levels in Smad3(-/-) vSMCs compared with Smad3(+/+) vSMCs. A ChIP assay showed that phosphorylated Smad3 directly binds to the Enpp1 gene. Furthermore, the calcification of aortic segments was attenuated by treatment with TGF-ß1 only in Smad3(+/+) mice. Taken together, we conclude that Pi-induced vSMC calcification is suppressed by Smad3 via an increase in ePPi.

MicroRNAs that target Ca(2+) transporters are involved in vascular smooth muscle cell calcification.

The role of microRNAs (miRNAs) in vascular calcification is currently unclear. To examine how miRNAs are involved in vascular smooth muscle cell (VSMC) calcification, we explored the alteration of miRNAs in VSMC calcification in vitro and in vivo. Klotho homozygous mutant mice (kl/kl) display vascular calcification and have perturbations of calcium handling. We therefore hypothesized that the calcium perturbations in VSMCs could be mediated by miRNAs. Using an miRNA array analysis, we demonstrated that miRNAs are aberrantly expressed in the aortic media of 3-week-old kl/kl mice compared with wild-type (WT) mice. The expression levels of miR-135a(*), miR-762, miR-714, and miR-712(*) in the aortic media of kl/kl mice were significantly higher than in WT mice. We used quantitative real-time reverse transcriptase polymerase chain reaction to further confirm that these miRNAs were increased in the aortic media of kl/kl mice and in cultured VSMCs treated with high phosphate and calcium. A search of the miRNA database indicated that the Ca(2+) efflux proteins NCX1, PMCA1, and NCKX4 frequently appeared as potential targets of these miRNAs. The transfection of miRNA mimics into cultured VSMCs reduced the protein levels of each potential target. Conversely, miRNA inhibitors reduced phosphate and calcium-induced VSMC calcification. Furthermore, these inhibitors decreased the intracellular Ca(2+) concentration in cultured VSMCs after treatment with phosphate and calcium. Our results suggest that increased expression of miR-135a(*), miR-762, miR-714, and miR-712(*) in VSMCs may be involved in VSMC calcification by disrupting Ca(2+) efflux proteins.

Diverse roles of macrophages in atherosclerosis: from inflammatory biology to biomarker discovery.

Cardiovascular disease, a leading cause of mortality in developed countries, is mainly caused by atherosclerosis, a chronic inflammatory disease. Macrophages, which differentiate from monocytes that are recruited from the blood, account for the majority of leukocytes in atherosclerotic plaques. Apoptosis and the suppressed clearance of apoptotic macrophages (efferocytosis) are associated with vulnerable plaques that are prone to rupture, leading to thrombosis. Based on the central functions of macrophages in atherogenesis, cytokines, chemokines, enzymes, or microRNAs related to or produced by macrophages have become important clinical prognostic or diagnostic biomarkers. This paper discusses the impact of monocyte-derived macrophages in early atherogenesis and advanced disease. The role and possible future development of macrophage inflammatory biomarkers are also described.

Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology.

Optical coherence tomography (OCT) is a coronary artery imaging technique with high resolution. Second-generation frequency-domain OCT (FD-OCT) technology allows safer and faster clinical application compared with first-generation time-domain OCT (TD-OCT). Only limited validation studies compare FD-OCT with other modes of analysis: histology, which is the current gold standard, and intravascular ultrasound (IVUS). This study therefore aims to demonstrate the accuracy of FD-OCT images compared with IVUS and histology. FD-OCT and IVUS images were acquired from 203 segments from 31 coronary arteries obtained at autopsy from 20 cadavers. Of these, 30 randomly-selected pairs were used to create three classifications of plaque type based on morphological features in FD-OCT and IVUS compared with corresponding histopathology. The remaining 173 pairs were used to demonstrate the diagnostic accuracy for classification of coronary plaques by FD-OCT. Plaque type distributions were 27% fibroatheroma, 22% fibrocalcific plaque and 51% fibrous plaque. The diagnostic accuracies of FD-OCT for fibroatheroma, fibrocalcific plaque and fibrous plaque were 90, 95 and 93%, respectively. Those of IVUS were 81, 89 and 84%, respectively. FD-OCT achieved high diagnostic accuracy for the classification of coronary plaques comparable to TD-OCT. Physicians should consider the differences in the ability to classify plaque morphology of OCT of imaging devices when applying their use.

In vivo optical coherence tomography imaging and histopathology of healed coronary plaques.

BACKGROUND AND AIMS: The aim of this study was to assess agreement between optical coherence tomography (OCT) and histopathology for healed coronary plaques (HCPs) in human coronary arteries ex vivo, and to evaluate the prevalence and characteristics of HCPs in vivo. METHODS: Ex vivo OCT images were co-registered with histopathology in 144 cross-sections with ≥50% stenosis. Of these, 30 randomly selected pairs were employed to define morphological features of OCT for HCPs (OCT-derived HCPs); the remaining 114 pairs were used to evaluate the accuracy of OCT in detecting histologically-defined HCPs. In a clinical study, 60 target lesions from 60 patients with stable ischemic heart disease were divided into 2 groups according to the presence or absence of OCT-derived HCPs. Plaque characteristics were compared between the two groups. RESULTS: In the autopsy study, an OCT-derived HCP was defined as a plaque with heterogeneous signal-rich layers of different optical signal density. The sensitivity, specificity, positive predictive value, and negative predictive value of OCT-derived HCP to detect histologically-defined HCPs were 81%, 98%, 93%, and 93%, respectively. In the clinical study, 46 (77%) had OCT-derived HCPs. Both microvessels and macrophages were more frequently identified in OCT-derived HCPs compared to their counterparts (43% vs. 0%; p<0.01, 70% vs. 21%; p<0.01, respectively). CONCLUSIONS: An ex vivo OCT image has a good agreement with histology for HCPs detection. HCPs were frequently identified by OCT in target lesions in stable ischemic heart disease patients. OCT may be a useful intracoronary imaging for HCPs detection in vivo.

Automated lipid-rich plaque detection with short wavelength infra-red OCT system.

Aims: Vulnerable coronary plaque is characterized by a large lipid core. Although commercially-available optical coherence tomography (OCT) systems use near-infrared light at 1300 nm wavelength, lipid shows characteristic absorption at 1700 nm. Therefore, we developed a novel, short wavelength infra-red, spectroscopic, spectral-domain OCT. The aim of the present study is to evaluate the accuracy of short wavelength (1700 nm) infra-red optical coherence tomography (SWIR-OCT) for identification of lipid tissue within coronary plaques. Methods and results: Twenty-three coronary arteries from 10 cadavers were imaged at physiological pressure with 2.7 Fr SWIR-OCT catheter. When a blood-free image was observed, the SWIR-OCT imaging core was withdrawn at a rate of 20 mm/s using an automatic pullback device. SWIR-OCT images were acquired at 94 frames/s and digitally archived. SWIR-OCT generated grey-scale cross sectional images and colour tissue maps of all of the plaque by using a lipid analysis algorithm. After SWIR-OCT imaging, the arteries were pressure-fixed, sliced by cryostat and stained with Oil Red O, and then corresponding histology was collected in matched images. Regions of interest, selected from histology, were 117 lipidic and 34 fibrotic/calcified regions. SWIR-OCT showed high sensitivity (89%) and specificity (92%) for identifying lipid tissue within coronary plaques. The positive predictive value and negative predictive value were 97% and 74%, respectively. Conclusion: SWIR-OCT accurately identified lipid tissue in coronary autopsy specimens. This new technique may hold promise for identifying histopathological features of coronary plaque at risk for rupture.

B-Cell-Rich T-Cell Lymphoma Associated with Epstein-Barr Virus-Reactivation and T-Cell Suppression Following Antithymocyte Globulin Therapy in a Patient with Severe Aplastic Anemia.

B-cell lymphoproliferative disorder (B-LPD) is generally characterized by the proliferation of Epstein-Barr virus (EBV)-infected B lymphocytes. We here report the development of EBV-negative B-LPD associated with EBV-reactivation following antithymocyte globulin (ATG) therapy in a patient with aplastic anemia. The molecular autopsy study showed the sparse EBV-infected clonal T cells could be critically involved in the pathogenesis of EBV-negative oligoclonal B-LPD through cytokine amplification and escape from T-cell surveillances attributable to ATG-based immunosuppressive therapy, leading to an extremely rare B-cell-rich T-cell lymphoma. This report helps in elucidating the complex pathophysiology of intractable B-LPD refractory to rituximab.

Optical coherence tomography assessment of efficacy of thrombus aspiration in patients undergoing a primary percutaneous coronary intervention for acute ST-elevation myocardial infarction.

OBJECTIVE: We used optical coherence tomography (OCT) to assess the impact of thrombus aspiration before angioplasty on poststenting tissue protrusions in patients undergoing a primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS: A total of 188 patients with STEMI who underwent thrombus-aspiration PCI (n=113) or standard PCI (n=75) were examined in this study. OCT was performed immediately after primary PCI to assess lesion morphology in the stented segment. The minimum stent area was similar between the thrombus-aspiration PCI group and the standard PCI group [7.4 interquartile range (IQR): 5.8-9.4 vs. 7.4 IQR: 5.8-8.9 mm², P=0.788]. The maximum tissue protrusion area [0.6 (IQR: 0.3-1.1) vs. 1.2 (IQR: 0.8-1.9) mm², P<0.001], the mean tissue protrusion area [0.1 (IQR: 0.1-0.2) vs. 0.5 (IQR: 0.3-0.8) mm², P<0.001], and tissue protrusion volume [2.3 (IQR: 1.3-4.3) vs. 8.3 (IQR: 5.4-14.6) mm², P<0.001] were significantly smaller in the thrombus-aspiration PCI group compared with the standard PCI group. Minimum lumen area was significantly greater in the thrombus-aspiration PCI group compared with the standard PCI group [6.9 (IQR: 5.4-8.8) vs. 6.3 (IQR: 4.6-7.8) mm², P=0.033]. CONCLUSION: Thrombus aspiration before angioplasty in patients with STEMI was associated with significantly smaller tissue protrusion and larger lumen poststenting compared with standard PCI. Thrombus aspiration in primary PCI favorably influenced lesion morphologies in the stented segment.

Elevated serum 1,25(OH)2-vitamin D3 level attenuates renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction in kl/kl mice.

Previous studies have suggested that Klotho provides reno-protection against unilateral ureteral obstruction (UUO)-induced renal tubulointerstitial fibrosis (RTF). Because the existing studies are mainly performed using heterozygous Klotho mutant (HT) mice, we focused on the effect of UUO on homozygous Klotho mutant (kl/kl) mice. UUO kidneys from HT mice showed a significantly higher level of RTF and TGF-ß/Smad3 signaling than wild-type (WT) mice, whereas both were greatly suppressed in kl/kl mice. Primary proximal tubular epithelial culture cells isolated from kl/kl mice showed no suppression in TGF-ß1-induced epithelial mesenchymal transition (EMT) compared to those from HT mice. In the renal epithelial cell line NRK52E, a large amount of inorganic phosphate (Pi), FGF23, or calcitriol was added to the medium to mimic the in vivo homeostasis of kl/kl mice. Neither Pi nor FGF23 antagonized TGF-ß1-induced EMT. In contrast, calcitriol ameliorated TGF-ß1-induced EMT in a dose dependent manner. A vitamin D3-deficient diet normalized the serum 1,25 (OH)2 vitamin D3 level in kl/kl mice and enhanced UUO-induced RTF and TGF-ß/Smad3 signaling. In conclusion, the alleviation of UUO-induced RTF in kl/kl mice was due to the TGF-ß1 signaling suppression caused by an elevated serum 1, 25(OH)2 vitamin D3.

The Role of Tricho-Rhino-Phalangeal Syndrome (TRPS) 1 in Apoptosis during Embryonic Development and Tumor Progression.

TRPS1 is a GATA-type transcription factor that is closely related to human tricho-rhino-phalangeal syndrome (TRPS) types I and III, variants of an autosomal dominant skeletal disorder. During embryonic development, Trps1 represses Sox9 expression and regulates Wnt signaling pathways that determine the number of hair follicles and their normal morphogenesis. In the growth plate, Trps1 regulates chondrocytes condensation, proliferation, and maturation and phalangeal joint formation by functioning downstream of Gdf5 signaling and by targeting at Pthrp, Stat3 and Runx2. Also, Trps1 protein directly interacts with an activated form of Gli3. In embryonic kidneys, Trps1 functions downstream of BMP7 promoting the mesenchymal-to-epithelial transition, and facilitating tubule morphogenesis and ureteric bud branching. Moreover, Trps1 has been found to be closely related to tumorigenesis, invasion, and metastasis in prostate and breast cancers. It is interesting to note that during the development of hair follicles, bones, and kidneys, mutations in Trps1 cause, either directly or through crosstalk with other regulators, a notable change in cell proliferation and cell death. In this review, we will summarize the most recent studies on Trps1 and seek to elucidate the role for Trps1 in apoptotic regulation.

Scanning electron microscopic analysis of polymer damage in drug-eluting stents during multiple stenting.

Polymer damage of drug-eluting stents (DES) during percutaneous coronary intervention procedure could be associated with stent restenosis. We assessed the damage to the drug-containing polymer of DES during multiple stenting in a phantom model by using scanning-electron microscopy (SEM). Unexpanded sirolimus-eluting stent (SES; n = 15) was delivered through the formerly expanded SES (n = 15) in a bended polytetrafluoroethylene plastic tube. The stent was subcategorized into 4 segments (S), including distal (S1), mid distal (S2), mid proximal (S3) and proximal segments (S4), for qualitative SEM assessment. Polymer damage, such as detachments, missing or tears, was observed not only in the outer surface of the unexpanded stents (100%) but also in the inner surface of the formerly expanded stents (100%). There was a significant difference in the frequency of polymer damage among the 4 segments in the unexpanded stents (S1 vs. S2 vs. S3 vs. S4: 86.7 vs. 80.0 vs. 53.3 vs. 40.0%, p = 0.022) and the formerly expanded stents (S1 vs. S2 vs. S3 vs. S4: 80.0 vs. 73.3 vs. 73.3 vs. 40.0%, p = 0.041). The damage was distributed more frequently in distal part than proximal part of either unexpanded stents (S1 vs. S4, p = 0.0079) and the formerly expanded stents (S1 vs. S4, p = 0.0079). Delivery of DES through a formerly expanded DES could cause damage to drug-containing polymer of the stents.

The Roles of Mitogen-Activated Protein Kinase Pathways in TGF-ß-Induced Epithelial-Mesenchymal Transition.

The mitogen-activated protein kinase (MAPK) pathway allows cells to interpret external signals and respond appropriately, especially during the epithelial-mesenchymal transition (EMT). EMT is an important process during embryonic development, fibrosis, and tumor progression in which epithelial cells acquire mesenchymal, fibroblast-like properties and show reduced intercellular adhesion and increased motility. TGF-ß signaling is the first pathway to be described as an inducer of EMT, and its relationship with the Smad family is already well characterized. Studies of four members of the MAPK family in different biological systems have shown that the MAPK and TGF-ß signaling pathways interact with each other and have a synergistic effect on the secretion of additional growth factors and cytokines that in turn promote EMT. In this paper, we present background on the regulation and function of MAPKs and their cascades, highlight the mechanisms of MAPK crosstalk with TGF-ß signaling, and discuss the roles of MAPKs in EMT.

Left ventricular apical aneurysm due to unrecognized sarcoidosis.

A 47-year-old woman was hospitalized for syncope. An electrocardiogram showed complete right bundle branch block and T-wave inversion in leads III, aVF, and V2-4. Cardiac catheterization was performed since the echocardiogram demonstrated the existence of a left ventricular apical aneurysm and apical thrombus. Coronary angiography revealed normal coronary arteries. An endomyocardial biopsied specimen from the right ventricular apical wall demonstrated typical noncaseating granulomas with giant cells. There was no evidence suggesting the involvement of other systemic organs. The patient was diagnosed as having cardiac sarcoidosis. Cardiac sarcoidosis should be considered within a spectrum of diseases that cause left ventricular apical aneurysm.