Altered expression of matrix metalloproteinases in pig-to-primate xenotransplanted hearts.
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Publications and source records attributed to M Endoh.
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BACKGROUND: The mechanisms of intimal thickening in cardiac allograft vasculopathy (CAV) remain controversial after heart transplantation. Matrix metalloproteinase-2 (MMP-2) plays a crucial role in degrading extracellular matrix (ECM) during neointimal formation. Recently, it has been revealed that MMP-2 is activated by membrane-type 1 matrix metalloproteinase (MT1-MMP). This process involves tissue inhibitor of MMP-2 (TIMP-2), forming an MT1-MMP/TIMP-2/pro-MMP-2 complex. In this study, we hypothesize that these components contribute to the pathogenesis of CAV. METHODS: Heterotopic cardiac allografting was performed in randomly paired Japanese monkeys with an immunosuppressive regimen of intravenous administration of antihuman CD18 monoclonal antibody. The donor hearts were harvested at Days 22, 28, 40, 41, and 95 posttransplantation. We examined expression of MMP-2, MT1-MMP, and TIMP-2 of graft vessels using immunohistochemistry and protein level by western blot analysis. RESULTS: Pathologically, various degrees of neointimal formation were observed. In the allografts harvested at Days 22, 28, 40, and 41, MT1-MMP was expressed in the endothelial cells and smooth muscle cells (SMCs) in media of some arteries without histological change, accompanied by expression of MMP-2 and TIMP-2. In the severely thickened neointima of the allograft harvested at Day 95, MMP-2 and faint MT1-MMP were expressed in SMCs of severely thickened neointima and media; TIMP-2 expression was seen only in noncollagenous tissue of severely thickened neointima. MMP-2 protein was more intensely expressed in the allograft harvested at Day 95 than in the allograft harvest at Day 41, while TIMP-2 protein level was almost same in the 2 samples. CONCLUSION: We observed the simultaneous expression of MMP-2, MT1-MMP, and TIMP-2. Thus, ECM degradation triggered by MT1-MMP/TIMP-2/pro-MMP-2 complex could be a novel mechanism of CAV.
The role of Na(+)/H(+) exchange in endothelin-1 (ET-1)-induced increases in Ca(2+) transients and cell shortening was studied in rabbit ventricular myocytes loaded with indo-1/AM. Selective inhibitors of Na(+)/H(+) exchange HOE642 (4-isopropyl-3-methyl-sulphonylbenzoyl guanidine methanesulphonate) and KB-R9032 (N-(4-isopropyl-2,2-dimethyl-3-oxo-3, 4-dihydro-2H-benzo-[1,4]oxazine-6-carbonyl) guanidine methanesulphonate) were used as pharmacological tools for the analysis. ET-1 at 0.1 nM induced an increase in Ca(2+) transients by 45.6%, while it increased cell shortening by 109.6%. For a given increase in cell shortening, the ET-1-induced increase in Ca(2+) transients was much smaller than that induced by isoprenaline (ISO, 10 nM). Pretreatment with HOE642 and KB-R9032 (1 microM) inhibited the increase in cell shortening induced by 0.1 nM ET-1 by 51 and 65. 4%, respectively, without a significant alteration of ET-1-induced increase in Ca(2+) transients. HOE642 and KB-R9032 did not affect baseline levels of cell shortening and peak Ca(2+) transients, and the effects of ISO (10 nM). These results indicate that activation of Na(+)/H(+) exchange by ET-1 may play an important role in the positive inotropic effect and the ET-1-induced increase in myofilament Ca(2+) sensitivity in rabbit ventricular myocytes.
BACKGROUND: Profiling of gene expression in healthy and diseased renal tissue is important for elucidating the pathogenesis of renal diseases. Comprehensive information about the genes expressed in renal tissue is unavailable. The recently developed cDNA array hybridization methodology allows simultaneous monitoring of thousands of genes expressed renal tissue. METHODS: Complex [alpha-33P]-labeled cDNA probes were prepared from histopathologically uninvolved remnants of nine renal tissues obtained by nephrectomy. Each probe was hybridized to a high-density array of 18,326 paired target genes. The radioactive hybridization signals by phosphorimager screens were quantitated by special software. Bioinformatics from public genomic databases were used to assign a chromosomal location of each expressed transcript and gene function. Cluster analysis was used to arrange genes according to the similarity in pattern of gene expression. RESULTS: A total of 7563 different gene transcripts was detected in the nine tissue samples. Approximately 870 of these genes were full-length mRNA human transcripts (HT), and the remaining 6693 were expressed sequence tags (ESTs). The full-length transcripts were classified by function of the gene product and were listed with information of their chromosomal positions. To allow a comparison between gene expression in clinical and experimental studies, the mouse genes with known similar function to the human counterpart were included in the bioinformatics analysis. Cluster analysis of 502 full-length genes that are expressed in four or more renal tissues revealed more than 110 genes that are highly expressed in all the renal specimens. CONCLUSIONS: The presented data constitute a comprehensive preliminary transcriptional map of the adult human renal cortex. The information may serve as a resource for speeding up the discovery of genes underlying human renal disease. The integrated listing of the full-length expressed human and mouse genes is available through e-mail (Abdalla_Rifai@Brown.edu).
To clarify the incidence and characteristics of hematopoietic cell transplantation (HCT)-related nephropathy (HCT-N) in Japan, we sent questionnaire letters to 188 hematologic divisions of 91 hospitals and analyzed the responses. Of 2,136 Japanese hematopoietic cell transplant recipients, 51 patients (2.4%) had HCT-N. The early-onset (</=30 days after HCT), middle-onset (31 to 120 days after HCT), and late-onset (>180 days after HCT) groups included 20, 16, and 15 patients, respectively. The early-onset group mainly consisted of patients with acute renal failure (ARF) and hemolytic uremic syndrome and/or thrombotic thrombocytopenic purpura. ARF was the dominant type in the middle-onset group. The main phenotype of the late-onset group was nephrotic syndrome, which correlated with chronic graft-versus-host disease (P=0.008). The total amounts of irradiation for patients with chronic renal failure and urinary abnormality were significantly greater than those for patients with ARF (P=0.004). The survival rate of the early-onset and middle-onset groups was 47.2%, whereas 87% of patients in the late-onset group survived (P=0.002). HCT-N is expected to become a serious and important problem in Japan because of the increasing number of HCTs from unrelated donors.
BACKGROUND: We investigated the effects of EMD 57033, a prototype Ca2+ sensitizer, and beta-adrenoceptor agonists in ventricular myocytes isolated from the volume-overload (V-O) heart failure model of the rabbit. METHODS AND RESULTS: V-O cardiac hypertrophy was induced in rabbits by the formation of an arterio-venous shunt between the carotid artery and jugular vein 12 to 15 weeks after the operation. Ventricular myocytes were enzymically isolated from normal and V-O rabbit hearts. The myocyte was loaded with a fluorescence Ca2+ dye, indo-1, and Ca2+ transients, and cell lengths were measured simultaneously. V-O myocytes were significantly larger than control myocytes. Duration of Ca2+ transients and cell shortening was significantly longer in the V-O myocytes than in control myocytes. Effects of cardiotonic interventions, including EMD 57033, isoproterenol, and dobutamine, on Ca2+ transients and cell shortening in V-O myocytes were compared with those in control rabbit myocytes. Isoproterenol and dobutamine increased the systolic cell shortening and peak Ca2+ transients and abbreviated the duration of cell shortening and Ca2+ transients. These responses were markedly attenuated in V-O myocytes. By contrast, the response of cell shortening to EMD 57033 was unaltered, and the Ca2+ sensitizing effect of EMD 57033 was rather enhanced in V-O myocytes. CONCLUSION: Our results indicate that the effectiveness of Ca2+ sensitizers is maintained in the V-O rabbit hypertrophy and heart failure model in contrast to the blunted response to beta-adrenoceptor agonists, which provides an insight on therapeutic strategy with Ca2+ sensitizers for the treatment of contractile dysfunction in congestive heart failure.
PURPOSE: To describe the characteristics of pancreatoblastoma. MATERIAL AND METHODS: We studied 3 cases of pancretoblastoma and reviewed another 59 cases. Parameters analyzed were tumor site, hemorrhage, capsule formation, necrosis, vascularity, production of alpha-fetoprotein (AFP), cystic changes and calcification. RESULTS: The diagnostic findings were as follows: pancreatic head origin (24/54, 44%), pancreatic body and tail origin (30/54, 56%), hemorrhage (16/17, 94%), capsule formation (24/26, 92%), necrosis (28/31, 90%), hypervascularity (10/14, 71%), production of AFP (19/28, 68%), cystic changes (11/16, 69%), and calcification (10/21, 48%). All neonatal cases demonstrated cystic changes. Three of them were patients with Beckwith-Wiedmann syndrome. The incidence of capsule formation and calcification was not related to the origin of the tumor. CONCLUSION: The most common features of pancreatoblastoma are hemorrhage, capsule formation and necrosis.
The present study was undertaken to investigate the interaction between endothelin-1 (ET-1) and norepinephrine (NE) on contractile regulation in dog ventricular myocardium. ET-1 alone did not elicit any inotropic response in isolated dog ventricular trabeculae (37 degrees C, 0.5 Hz). In the presence of NE at a high concentration (10(-7) M), ET-1 (10(-8) M) elicited a long-lasting negative inotropic effect, while in the presence of NE at a moderate concentration (3 x 10(-8) M) it produced a biphasic inotropic effect: a sustained positive inotropic effect subsequent to a short-lasting negative inotropic effect. In the presence of a lower concentration (10(-9) M) that affected scarcely the basal force of contraction, ET-1 produced a pronounced positive inotropic effect in association with negative lusitropic and negative clinotropic effects in a concentration-dependent manner subsequent to a small transient negative inotropic effect. The presented results indicate that not only the extent, but also the quality of the inotropic response to ET-1 is determined by the level of NE in the biophase. The crosstalk of ET-1 with NE may play a crucial role in pathophysiological regulation of cardiac contractility in intact dog ventricular myocardium.
We examined the effects of the potassium channel opener KRN4884 (5-amino-N-[2-(2-chlorophenyl)ethyl]-N'-cyano-3-pyridinecarboxamidine ) on cardiovascular metabolic syndrome (i.e., syndrome X), in rats. High-fructose diet rats developed hypertension, hypertriglyceridemia, increased total cholesterol/HDL (high-density lipoprotein)-cholesterol ratio, and hyperinsulinemia, KRN4884 (0.3-3.0 mg/kg, twice a day for 14 days, p.o.) alleviated the risk factors in fructose-fed rats. Furthermore, fructose-fed rats exhibited impairment of glucose tolerance and excess insulin secretion when loaded with glucose orally. Treatment with KRN4884 (1.0 mg/kg, twice a day for 14 days, p.o.) improved the glucose intolerance and inhibited hypersecretion of insulin in the glucose-loaded, fructose-fed rats. In contrast, KRN4884 (0.3-1.0 mg/kg, twice a day for 10 days, p.o.) did not affect serum triglyceride, cholesterol, glucose, or insulin concentrations in normal rats. LPL (lipoprotein lipase) activities in skeletal muscle and adipose tissue, and HTGL (hepatic triglyceride lipase) activity in liver were measured after administration of KRN4884 or vehicle twice a day for 14 days in fructose-fed rats. KRN4884 caused a significant increase in LPL activity in muscle and tended to increase LPL activity in adipose tissue in fructose-fed rats. HTGL was decreased in fructose-fed rats as compared with normal controls and was unaffected by KRN4884. These findings suggested that KRN4884 enhances insulin sensitivity and LPL activity, which are related to glucose and lipid metabolism and may be useful for the treatment of syndrome X.
We performed experiments in rabbit ventricular papillary muscles loaded with aequorin to elucidate the mechanism of positive inotropic effect (PIE) of OR-1896, an active metabolite of levosimendan. The concentration-response curve (CRC) for OR-1896 was biphasic: PIE of OR-1896 reached a plateau at 10(-5) M (first phase), and the CRC became steeper at 10(-3) M and higher (second phase). Maximal response of the first phase was 11% of the maximal response to isoproterenol (ISOmax) and associated with an increase in Ca2+ transients of 5% of ISOmax. For a given degree of PIE, the increase in Ca2+ transients by OR-1896 was lower than that induced by elevation of [Ca2+]o. The PIE of OR-1896 was not associated with impairment of relaxation, and it was abolished by carbachol. In conclusion, OR-1896 has a PIE partly due to an increase in myofibrillar Ca2+ sensitivity that is exerted through crosstalk with signal transduction mediated by cyclic adenosine monophosphate (cAMP).
The effect of endothelin-1 (ET-1) on L-type Ca2+ current (I(Ca)) and the interaction of ET-1 with beta-adrenergic stimulation were studied in dog ventricular myocytes by means of a whole-cell patch-clamp technique. ET-1 (10(-8) M) had no effect on the baseline I(Ca), but at 10(-9)-10(-7) M, it inhibited the isoproterenol (ISO)-induced increase in I(Ca). The maximal inhibition induced by ET-1 at 3 x 10(-8) M was approximately 30%, and the median inhibitory (IC50) value of ET-1 was 1.1 x 10(-9) M. The inhibitory action of ET-1 (10(-8) M) on the ISO-induced increase in I(Ca) was markedly attenuated by the ET(A) antagonist FR139317 (10(-6) M) and was partially inhibited by the ET(B) antagonist BQ-788 (10(-6) M). The inhibitory action of ET-1 was totally inhibited by the nonselective ET-receptor antagonist, TAK-044 (10(-6) M). These results indicate that ET-1 exerts an antiadrenergic effect on the ISO-induced increase in I(Ca), which is mediated mainly by ET(A), but activation of ET(B) receptors might contribute to the effect of ET-1 to a lesser extent.
Influence of JTH-601 [N-(3-hydroxy-6-methoxy-2,4,5-trimethylbenzyl)-N-methyl-2-(4-hydroxy-2-isopropyl-5-methylphenoxy)ethylamine hemifumarate], a selective alpha1-adrenoceptor antagonist, on alpha1-mediated positive inotropic effect (PIE) was studied in isolated rabbit papillary muscle (1 Hz at 37 degrees C). JTH-601 (0.1-10 microM) shifted the concentration-response curve (CRC) for PIE of phenylephrine mediated by alpha1-adrenoceptor (with timolol at 1 microM) to the right and downward. In the presence of 100 nM WB 4101, an alpha1A antagonist, the shift to the right disappeared and JTH-601 (1-3 microM) shifted CRC for phenylephrine downward. The antagonistic action of JTH-601 was unchanged by 100 nM (+)-niguldipine, another alpha1A antagonist. Following pretreatment with 10 microM chloroethylclonidine, an alpha1B antagonist, the shift of CRC for phenylephrine to the right disappeared and JTH-601 (3-10 microM) shifted CRC downward. Antagonistic action of JTH-601 (3 microM) was unaltered by 100 nM BMY 7378, an alpha1D antagonist. JTH-601 (10 microM) had no effect on beta-mediated PIE of isoproterenol. These results indicate that JTH-601 exerts an inhibitory action on alpha1-mediated PIE through antagonism of alpha1A- and/or alpha1B-adrenoceptors in rabbit ventricular myocardium. As an alpha1 antagonist, JTH-601 is much less potent in rabbit ventricular muscle than in smooth muscle.
The liver plays important roles in the clearance and metabolism of sex steroids. Its dysfunction is considered to influence the metabolic pathways of sex steroids, and to result in gynecomastia and other abnormalities of sex steroids. However, the details of its mechanism have not been well-characterized. We therefore examined the enzymes involved in the hepatic clearance and/or metabolism of sex steroids in human liver and its disorders using immunohistochemistry to determine whether there are any abnormalities of expression of these enzymes in human liver disorders. These enzymes are 17beta-hydroxysteroid dehydrogenase (17beta-HSD) type 2, an enzyme that catalyzes the biologically active estrogen, estradiol (E2), to inactive estrogen, estrone (El), and dehydroepiandrosterone sulfotransferase (DHEA-ST), which catalyzes sulfonation of dehydroepiandrosterone (DHEA) to form biologically inactive DHEA-S. A total of 162 cases including normal liver (n=31), chronic hepatitis (n=41), liver cirrhosis (n = 21), hepatocellular carcinoma (n = 47), cholangiocellular carcinoma (n = 22) and fetal liver (n = 4) were examined by immunohistochemistry. Both enzymes were expressed in the hepatocytes around portal area and central vein in normal liver. Immunopositive area for DHEA-ST was significantly larger in chronic hepatitis than in normal liver, but that of 17beta-HSD type 2 in chronic hepatitis was not different from normal liver. There were no significant differences in the immunopositive area for both enzymes between liver cirrhosis and normal liver. In hepatocellular carcinoma, immunoreactivity for both enzymes were categorized into Group A, or low positive group, and Group B, or high positive group. The latter tended to be poorly differentiated carcinoma. In cholangiocellular carcinoma, immunopositive areas of both enzymes were significantly smaller than those of normal liver. These findings indicate that the amount of expression of the enzymes involved in metabolism and/or clearance of sex steroids per hepatocyte did not decrease in liver cirrhosis. Therefore, sex steroids' abnormalities may be due to the decreased quantity of hepatocytes associated with liver cirrhosis. In hepatocellular carcinoma, some poorly differentiated cases were associated with increased expression of 17beta-HSD type 2 but its biological significance needs to be determined by further studies.
46 formalin-fixed, paraffin-embedded skin biopsy specimens, which were clinically suspected or diagnosed as early leprosy, were retrieved from the files of Sichuan, China from 1997 to 1999. All of them were examined by polymerase chain reaction (PCR) using the primers amplifying the 130 base-pair fragment of the gene from the 16S ribosomal RNA of Mycobacterium leprae, hematoxylin and eosin (H&E) staining, modified Fite-Faraco technique for M. leprae and immunostaining with the antiserum against the PGL-1, LAM-B, S-100 protein using ABC method. PCR was positive for 27 (58.7%) of 46 specimens. In 13 (28.3%) among them, only PCR signals were positive for M. leprae and all other test were negative. AFB was positive for 7 (15.2%) of 46, PGL-1 was positive for 17 (36.9%) of 46, LAM-B was positive for 10 (21.7%) of 46. Early epithelioid cells granuloma was detected in 4 (8.7%) patients (TT 3, BT 1), macrophage granuloma was detected in 1 (2.2%) patient (BL), S-100 protein staining showed early nerve granuloma for 4 (8.7%) of 46, peripheral nerve inflammatory infiltration for 11 (23.9%) of 46. Comparison PCR with other method showed statistically significant difference. PCR have an advantage over microscopic examination in detecting M. leprae in biopsy specimens negative for acid-fast bacilli.