Plasma miR-124 as a biomarker for cerebral infarction

MicroRNAs (miRNAs) are endogenous small RNAs that play an important role in various physiological processes by downregulating target genes. Recently, plasma miRNAs have been investigated as biomarkers for various diseases. In this study, miRNA array analysis in various tissues showed that miR-124 is almost exclusively expressed in the central nervous system and neuronal cells, suggesting that it might be useful as a potential biomarker for neurological diseases. We examined whether plasma concentrations of brain-specific miRNA can serve as a biomarker for cerebral infarction, where the cerebral infarction was modeled by middle cerebral artery occlusion (MCAO) in the rat. Plasma concentrations of miR-124 were significantly elevated at 6 h, and remained elevated at 48 h after MCAO introduction. Thus, plasma concentration of miR-124 provides a promising candidate biomarker for early detection of cerebral infarction.     

Saireito probably prevents mesangial cell proliferation in HIGA mice via PDGF-BB tyrosine kinase inhibition

Background In this study, we administered saireito to high serum IgA (HIGA) mice and investigated its inhibitory effect on platelet-derived growth factor (PDGF) receptor tyrosine kinase (which causes mesangial proliferation) as one of the possible antinephritic mechanisms of saireito. Methods Female HIGA/NscSlc mice, aged 10 weeks, were divided into five groups (each, n = 12; a control group, three saireito-mixed feed groups, and a captopril-mixed feed group) so that the plasma IgA levels were comparable among the groups. After the grouping, the animals were administered the saireito or captopril, mixed in the feed, until the age of 45 weeks. Results At the age of 45 weeks, the glomerular cell number was 47.8 ± 3.9 / cross section in the HIGA mice in the control group, but 41.6 ± 2.3 / cross section in the 1.3% saireito-mixed feed group and 38.7 ± 3.5 / cross section in the captopril-mixed feed group, being significantly lower in both these treatment groups than in the control group. At the age of 45 weeks, the sclerosis score in the HIGA mice in the control group was 0.92 ± 0.23. However, the sclerosis scores in the 0.26% (0.59 ± 0.26) and 1.3% (0.58 ± 0.16) saireito-mixed feed groups were significantly lower than that in the control group. In the captopril-mixed feed group, the sclerosis score was 0.64 ± 0.34, significantly lower than that in the control group. It was clarified that saireito suppressed mesangial cell proliferation without showing any cytotoxicity. Furthermore, as a result of investigating the mesangial cell proliferation-suppressing effect similarly with the 23 substances constituting saireito, a proliferation-suppressing effect was recognized with isoliquiritigenin (a component of Glycyrrhizae Radix) and oroxylin A (a component of Scutellariae Radix). Oroxylin A and isoliquiritigenin showed an inhibitory effect on PDGF receptor tyrosine kinase. Furthermore, the inhibitory effects of oroxylin A and isoliquiritigenin on tyrosine kinase were found to be specific to the PDGF receptor, and showed no influence on the tyrosine kinase activities of other growth-factor receptors examined. Conclusion These results suggest that the antinephritic effects of saireito in HIGA mice may be partly due to the inhibiton of PDGF tyrosine kinase by oroxylin A and isoliquiritigenin, components of saireito.     

Caveolin-1 in extracellular matrix vesicles secreted from osteoblasts

Caveolin-1 is an essential and signature protein of caveolae, which are small invaginations of the plasma membrane enriched in cholesterol and sphingolipids. Although high levels of expression of caveolin-1 have been demonstrated in osteoblasts as well as endothelial cells, fibroblasts, and muscular cells, the role of caveolin-1 in osteoblasts has not been clarified. Here, we show that caveolin-1 is secreted from osteoblasts in the form of matrix vesicles; extracellular vesicles released from the plasma membrane of osteoblasts. In this study, caveolae and matrix vesicles were similarly enriched in cholesterol and sphingomyelin in fractions isolated from mineralizing MC3T3-E1 cells. Interestingly, in the MC3T3-E1 cells caveolin-1 was enriched in the matrix vesicle fraction as well as the caveolar membrane fraction, and the amount of caveolin-1 in the matrix vesicle fraction increased as differentiation progressed. Localization of caveolin-1 in matrix vesicles was also confirmed in murine tibia. Furthermore, overexpression of caveolin-1 enhanced matrix calcification in MC3T3-E1 cells, whereas knockdown of caveolin-1 diminished it. These results suggest that secreted caveolin-1 as a component of matrix vesicles may play an important role in osteoblast calcification.     

Pirh2 promotes ubiquitin-dependent degradation of the cyclin-dependent kinase inhibitor p27Kip1

The cyclin-dependent kinase inhibitor p27(Kip1) is degraded in late G(1) phase by the ubiquitin-proteasome pathway, allowing cells to enter S phase. Due to accelerated degradation of p27(Kip1), various human cancers express low levels of p27(Kip1) associated with poor prognosis. S-phase kinase-associated protein 2, the F-box protein component of an SCF ubiquitin ligase complex, is implicated in degradation of p27(Kip1) during S-G(2) phases. Recently, Kip1 ubiquitination-promoting complex has been reported as another ubiquitin ligase that targets cytoplasmic p27(Kip1) exported from the nucleus in G(0)-G(1) phases. Here, we identified a RING-H2-type ubiquitin ligase, Pirh2, as a p27(Kip1)-interacting protein. Endogenous Pirh2 physically interacted with endogenous p27(Kip1) in mammalian cells. Pirh2 directly ubiquitinated p27(Kip1) in an intact RING finger domain-dependent manner in vivo, as well as in vitro. Ablation of endogenous Pirh2 by small interfering RNA increased the steady-state level of p27(Kip1) and decelerated p27(Kip1) turnover. Depletion of Pirh2 induced accumulation of p27(Kip1) in both the nucleus and cytoplasm. Pirh2 expression was induced from late G(1)-S phase, whereas p27(Kip1) was decreased in synchronization with accumulation of Pirh2. Furthermore, reduction of Pirh2 resulted in an impairment of p27(Kip1) degradation and an inhibition of cell cycle progression at G(1)-S transition in a p53-independent manner. Overall, the results indicate that Pirh2 acts as a negative regulator of p27(Kip1) function by promoting ubiquitin-dependent proteasomal degradation.     

Transcatheter arterial chemoembolization for hepatocellular carcinoma fed by the reconstructed inferior phrenic artery: anatomical and technical analysis

PURPOSE: To evaluate reconstructed patterns of occluded inferior phrenic artery (IPA) and determine the technical success rate and complications of transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) fed by the occluded IPA through the anastomosing branch. MATERIALS AND METHODS: In 19 patients, 24 IPAs, including two that had been previously embolized, were demonstrated through collateral pathways. The incidence of each collateral circulation was evaluated. Thirteen IPAs in 12 patients fed the tumor and TACE was attempted. TACE was performed only if the catheter could be advanced into the anastomosing branch so that the nontarget branches were avoided. RESULTS: A reconstructed unilateral IPA was observed in 14 patients (11 right IPAs and three left IPAs) and two reconstructed IPAs were observed in five. The IPA was demonstrated through the dorsal pancreatic artery (n = 13), inferior or middle adrenal artery (n = 7), left gastric artery (n = 2), contralateral IPA (n = 2), lumbar artery (n = 1), and small branch derived from the celiac trunk (n = 1). Five IPAs (21%) were demonstrated through more than two separate arteries, including two demonstrated through both dorsal pancreatic arteries arising from the celiac and superior mesenteric artery. The IPA opacified through the lumbar artery had been previously embolized. TACE of the reconstructed IPA was possible in 10 of 13 IPAs (77%). Complications related to the procedure were a small amount of pleural effusion (n = 4) and basal atelectasis (n = 2). CONCLUSION: The IPA is reconstructed mainly through the retroperitoneal anastomosing branch in the upper abdomen. TACE of the reconstructed IPA can be performed with a high success rate without major complications.     

Regulation of endothelial Fas expression as a mechanism of promotion of vascular integrity by mural cells in tumors

Angiogenesis is a multi‐step process that culminates in vascular maturation whereby nascent vessels stabilize to become functional, and mural cells play an essential role in this process. Recent studies have shown that mural cells in tumors also promote and maintain vascular integrity, with wide‐reaching clinical implications including the regulation of tumor growth, metastases, and drug delivery. Various regulatory signaling pathways have been hitherto implicated, but whether regulation of Fas‐dependent apoptotic mechanisms is involved has not yet been fully investigated. We first compared endothelial FAS staining in human pancreatic ductal adenocarcinomas and colon carcinomas and show that the latter, characterized by lower mural cell coverage of tumor vasculature, demonstrated higher expression of FAS than the former. Next, in an in vitro coculture system of MS‐1 and 10T1/2 cells as endothelial and mural cells respectively, we show that mural cells decreased endothelial Fas expression. Then, in an in vivo model in which C26 colon carcinoma cells were inoculated together with MS‐1 cells alone or with the further addition of 10T1/2 cells, we demonstrate that mural cells prevented hemorrhage. Finally, knockdown of endothelial Fas sufficiently recapitulated the protection against hemorrhage seen with the addition of mural cells. These results together suggest that regulation of endothelial Fas signaling is involved in the promotion of vascular integrity by mural cells in tumors.     

Serum pentraxin 3 as a possible marker for mature cystic teratomas

Pentraxin 3 (PTX3) is an inflammatory mediator that is released by a wide range of tissues and cells. Elevated PTX3 levels may represent a useful diagnostic and/or prognostic marker for a number of diseases. The purpose of this study was to investigate serum PTX3 levels in benign gynecological conditions including mature cystic teratomas (MCTs), endometriomas, and uterine leiomyomas. Serum PTX3 levels of the MCT group were found to be significantly higher compared to those of the other groups, including healthy controls (p?=?0.001), although carbohydrate antigen 19-9 (CA19-9) did not exhibit a significant difference. Serum PTX3 levels of the MCT, but not the endometrioma group, were also found to have significantly decreased post-operatively (mean?±?standard deviation, 4.98?±?2.10 to 3.61?±?1.53?ng/mL). Immunohistochemical analyses demonstrated positive staining for PTX3 protein in the sebaceous glands, epidermal tissues, and hair roots of MCT specimens. PTX3 is expressed by MCTs and is associated with increased serum concentrations compared to healthy controls and patients with either endometriomas or uterine leiomyomas. We conclude that serum PTX3 levels could be used as a potential diagnostic marker for MCTs, especially helpful in differentiating them from endometriomas with elevated expression of CA19-9.