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Taku Fukuzawa,
Masanori Fukazawa,
Otoya Ueda,
Hideaki Shimada,
Aki Kito,
Mami Kakefuda, Yosuke Kawase,
Naoko A Wada,
Chisato Goto,
Naoshi Fukushima,
Kou-Ichi Jishage,
Kiyofumi Honda,
George L King,
Yoshiki Kawabe
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ABSTRACT: Although excessive fructose intake is epidemiologically linked with dyslipidemia, obesity, and diabetes, the mechanisms regulating plasma fructose are not well known. Cells transfected with sodium/glucose cotransporter 5 (SGLT5), which is expressed exclusively in the kidney, transport fructose in vitro; however, the physiological role of this transporter in fructose metabolism remains unclear. To determine whether SGLT5 functions as a fructose transporter in vivo, we established a line of mice lacking the gene encoding SGLT5. Sodium-dependent fructose uptake disappeared in renal brush border membrane vesicles from SGLT5-deficient mice, and the increased urinary fructose in SGLT5-deficient mice indicated that SGLT5 was the major fructose reabsorption transporter in the kidney. From this, we hypothesized that urinary fructose excretion induced by SGLT5 deficiency would ameliorate fructose-induced hepatic steatosis. To test this hypothesis we compared SGLT5-deficient mice with wild-type mice under conditions of long-term fructose consumption. Paradoxically, however, fructose-induced hepatic steatosis was exacerbated in the SGLT5-deficient mice, and the massive urinary fructose excretion was accompanied by reduced levels of plasma triglycerides and epididymal fat but fasting hyperinsulinemia compared with fructose-fed wild-type mice. There was no difference in food consumption, water intake, or plasma fructose between the two types of mice. No compensatory effect by other transporters reportedly involved in fructose uptake in the liver and kidney were indicated at the mRNA level. These surprising findings indicated a previously unrecognized link through SGLT5 between renal fructose reabsorption and hepatic lipid metabolism.
PLoS ONE 01/2013; 8(2):e56681. · 4.09 Impact Factor
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Otoya Ueda,
Hiromi Tateishi,
Yoshinobu Higuchi,
Etsuko Fujii,
Atsuhiko Kato, Yosuke Kawase,
Naoko A Wada,
Takanori Tachibe,
Mami Kakefuda,
Chisato Goto,
Makoto Kawaharada,
Shin Shimaoka,
Kunihiro Hattori,
Kou-Ichi Jishage
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ABSTRACT: For clinical trials of therapeutic monoclonal antibodies (mAbs) to be successful, their efficacy needs to be adequately evaluated in preclinical experiments. However, in many cases it is difficult to evaluate the candidate mAbs using animal disease models because of lower cross-reactivity to the orthologous target molecules. In this study we have established a novel humanized Castleman's disease mouse model, in which the endogenous interleukin-6 receptor gene is successfully replaced by human IL6R, and human IL6 is overexpressed. We have also demonstrated the therapeutic effects of an antibody that neutralizes human IL6R, tocilizumab, on the symptoms in this mouse model. Plasma levels of human soluble IL6R and human IL6 were elevated after 4-week treatment of tocilizumab in this mouse model similarly to the result previously reported in patients treated with tocilizumab. Our mouse model provides us with a novel means of evaluating the in vivo efficacy of human IL6R-specific therapeutic agents.
Scientific Reports 01/2013; 3:1196.
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ABSTRACT: This review describes the study of freeze-dried mouse sperm for practical application in preserving and transporting genetic resources. Freeze-dried sperm can be used to preserve and transport genetic resources; however, there still remain many areas which need to be studied. In particular, it is essential to assure long-term preservation over several decades or centuries. Recently, the theory of accelerated degradation kinetics to freeze-dried mouse sperm has been applied, and found that long-term preservation by conventional methods requires temperatures lower than -80 C. When the relationship between the pressure at primary drying and the preservation potential of freeze-dried mouse sperm was examined, a pressure of 0.37 mbar at primary drying significantly improved the developmental rate to the blastocyst stage. In addition, it has been shown that freeze-dried sperm stored at -80 C with and without transportation can retain their ability to generate viable offspring after storage for up to 2 years. Sperm chromatin structure assay (SCSA) was applied to mouse sperm freeze-dried under several conditions and compared the results with the embryonic developmental rates of freeze-dried sperm after intracytoplasmic sperm injection (ICSI) and with comet assay results. Furthermore, SCSA might be useful for estimation of developmental potential of fertilized eggs derived from ICSI using freeze-dried sperm in mice.
Journal of Reproduction and Development 05/2011; 57(2):176-82. · 1.46 Impact Factor
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Kazunori Otsui,
Makoto Kakutani,
Koji Yuasa,
Atushi Nakano,
Chang-Ping Hu,
Akemi Kakino,
Yuko Sato,
Yoshiko Fujita, Yosuke Kawase,
Kou-ichi Jishage,
Hiroshi Suzuki,
Jawahar L Mehta,
Mitsuhiro Yokoyama,
Ken-Ichi Hirata,
Nobutaka Inoue,
Tatsuya Sawamura
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ABSTRACT: Aims Platelet aggregation at the injured surface of blood vessels plays a crucial role in arterial thrombosis. Platelet aggregation in plasma has been analyzed in the presence of calcium chelator to avoid coagulation. Here, we describe a novel mechanism of platelet aggregation that involves calcium-dependent binding between phosphatidylserine (PS) and lectin-like oxidized LDL receptor-1 (LOX-1), and contribution of platelet LOX-1 to arterial thrombosis. Methods and Results In vitro, LOX-1 gene deletion and anti-LOX-1 antibody suppressed the aggregation of platelets from mice and humans, respectively, in the absence of calcium chelating citrate, but not in the presence of citrate. LOX-1 blockade and annexin V, in parallel, suppressed platelet aggregation and shifted the population of aggregates from large to small in size. Simultaneous application of anti-LOX-1 antibody and annexin V did not exert additive suppressive effects on aggregation. On activation, platelets exposed LOX-1 and PS, and bound to PS-coated surface in LOX-1-dependent manner. In vivo, both LOX-1 deletion and anti-LOX-1 antibody significantly suppressed thrombus formation in mice and rats, respectively. Furthermore, platelet transfusion from LOX-1 knockout to wild-type mice still showed the suppressive effects of LOX-1 gene deletion, suggesting that platelet LOX-1 promoted thrombus formation. Conclusion LOX-1 blockade could be a novel approach to prevent platelet aggregation and thrombosis.
Cardiovascular research 08/2010; · 5.80 Impact Factor
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Takei Kake,
Hidetomo Kitamura,
Yuichiro Adachi,
Tetsuro Yoshioka,
Tomoyuki Watanabe,
Hiroaki Matsushita,
Toshihito Fujii,
Eri Kondo,
Takanori Tachibe, Yosuke Kawase,
Kou-ichi Jishage,
Akihiro Yasoda,
Masashi Mukoyama,
Kazuwa Nakao
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ABSTRACT: C-type natriuretic peptide (CNP) plays a critical role in endochondral ossification through guanylyl cyclase-B (GC-B), a natriuretic peptide receptor subtype. Cartilage-specific overexpression of CNP enhances skeletal growth and rescues the dwarfism in a transgenic achondroplasia model with constitutive active mutation of fibroblast growth factor receptor-3. For future clinical application, the efficacy of CNP administration on skeletal growth must be evaluated. Due to the high clearance of CNP, maintaining a high concentration is technically difficult. However, to model high blood CNP concentration, we established a liver-targeted CNP-overexpressing transgenic mouse (SAP-CNP tgm). SAP-CNP tgm exhibited skeletal overgrowth in proportion to the blood CNP concentration and revealed phenotypes of systemic stimulation of cartilage bones, including limbs, paws, costal bones, spine, and skull. Furthermore, in SAP-CNP tgm, the size of the foramen magnum, the insufficient formation of which results in cervico-medullary compression in achondroplasia, also showed significant increase. CNP primarily activates GC-B, but under high concentrations it cross-reacts with guanylyl cyclase-A (GC-A), a natriuretic peptide receptor subtype of atrial natriuretic peptides (ANP) and brain natriuretic peptides (BNP). Although activation of GC-A could alter cardiovascular homeostasis, leading to hypotension and heart weight reduction, the skeletal overgrowth phenotype in the line of SAP-CNP tgm with mild overexpression of CNP did not accompany decrease of systolic blood pressure or heart weight. These results suggest that CNP administration stimulates skeletal growth without adverse cardiovascular effect, and thus CNP could be a promising remedy targeting achondroplasia.
AJP Endocrinology and Metabolism 10/2009; 297(6):E1339-48. · 4.75 Impact Factor
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ABSTRACT: Zona incision using a piezo-micromanipulator (ZIP) has been demonstrated to be effective for in vitro fertilization (IVF) using cryopreserved C57BL/6 spermatozoa. In this study, ZIP oocytes inseminated with frozen-thawed genetically modified C57BL/6J or FVB mice spermatozoa (21 lines) showed fertilization rates of 22-75% and live fetus rates of 8-49%. In 6 of the lines, the fertilization rates for oocytes compared with ZIP (42-75%) were significantly higher than that of nontreated oocytes (0-50%). Using only 90 oocytes for IVF with ZIP, 5 breeding pairs were produced from cryopreserved genetically modified mice spermatozoa. Our results indicate that application of the ZIP technique is effective for IVF using cryopreserved genetically modified mouse spermatozoa.
Experimental Animals 08/2009; 58(4):415-9. · 0.92 Impact Factor
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Changping Hu,
Abhijit Dandapat,
Liuqin Sun,
Muhammad R Marwali,
Nobutaka Inoue,
Fumiaki Sugawara,
Kazuhiko Inoue, Yosuke Kawase,
Kou-ichi Jishage,
Hiroshi Suzuki,
Paul L Hermonat,
Tatsuya Sawamura,
Jawahar L Mehta
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ABSTRACT: Angiotensin II via type 1 receptor activation upregulates the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), and LOX-1 activation, in turn, upregulates angiotensin II type 1 receptor expression. We postulated that interruption of this positive feedback loop might attenuate the genesis of angiotensin II-induced hypertension and subsequent cardiac remodeling. To examine this postulate, LOX-1 knockout and wild-type mice were infused with angiotensin II or norepinephrine (control for angiotensin II) for 4 weeks. Angiotensin II-, but not norepinephrine-, induced hypertension was attenuated in LOX-1 knockout mice. Angiotensin II-induced cardiac remodeling was also attenuated in LOX-1 knockout mice. Importantly, angiotensin II type 1 receptor expression was reduced, and the expression and activity of endothelial NO synthase were preserved in the tissues of LOX-1 knockout mice given angiotensin II. Reactive oxygen species generation, nicotinamide-adenine dinucleotide phosphate oxidase expression, and phosphorylation of p38 and p44/42 mitogen-activated protein kinases were also much less pronounced in the LOX-1 knockout mice given angiotensin II. These alterations in biochemical and structural abnormalities were associated with preservation of cardiac hemodynamics in the LOX-1 knockout mice. To confirm that fibroblast function is modulated in the absence of LOX-1, cardiac fibroblasts from wild-type and LOX-1 knockout mice were treated with angiotensin II. Indeed, LOX-1 knockout mice cardiac fibroblasts revealed an attenuated profibrotic response on treatment with angiotensin II. These observations provide strong evidence that LOX-1 is a key modulator of the development of angiotensin II-induced hypertension and subsequent cardiac remodeling.
Hypertension 09/2008; 52(3):556-62. · 6.21 Impact Factor
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Changping Hu,
Jiawei Chen,
Abhijit Dandapat,
Yoshiko Fujita,
Nobutaka Inoue, Yosuke Kawase,
Kou-ichi Jishage,
Hiroshi Suzuki,
Dayuan Li,
Paul L Hermonat,
Tatsuya Sawamura,
Jawahar L Mehta
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ABSTRACT: LOX-1 is a newly described lectin-like receptor for oxidized-LDL (ox-LDL), which is over-expressed in the ischemic myocardium. To examine the pathogenic role of LOX-1 in the determination of ischemia-reperfusion (I-R) injury to the heart, we developed LOX-1 knockout (KO) mice, and subjected these mice to 60 min of left coronary artery occlusion followed by 60 min of reperfusion. I-R in the LOX-1 KO mice resulted in a significant reduction in myocardial injury as well as in accumulation of inflammatory cells in the I-R myocardium and lipid peroxidation (P<0.01 vs. wild-type mice). Concomitantly, there was significant preservation of cardiac function in the LOX-1 KO mice despite I-R (P<0.01 vs. the wild-type mice). The phosphorylation of oxidative stress-sensitive mitogen-activated protein kinase (p38MAPK) and protein kinase B/Akt-1, expression of nitrotyrosine and inducible nitric oxide synthase (iNOS), and superoxide dismutase activity were enhanced during I-R in the wild-type mice. These alterations in p38MAPK, Akt-1 and iNOS were much less pronounced in the LOX-1 KO mice. The superoxide dismutase activity increased further in the LOX-1 KO mice. These observations provide compelling evidence that LOX-1 may be a key modulator of myocardial I-R injury, and its effect is mediated by pro-oxidant signals. LOX-1 may be a potential target for therapy of myocardial ischemic injury.
Journal of Molecular and Cellular Cardiology 01/2008; 44(1):76-83. · 5.17 Impact Factor
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ABSTRACT: Freeze-dried mouse spermatozoa can be used for normal embryonic development after injection into oocytes, thus indicating that freeze-drying is a useful method for the storage and transportation of genetic materials from animals. We recently reported that storage of freeze-dried mouse spermatozoa requires maintenance at temperatures lower than -80 C for long-term preservation and a pressure of 0.37 mbar at primary drying and that these conditions significantly improve the developmental rate to the blastocyst stage. In this study, we examined the influence of transportation and preservation conditions on freeze-dried spermatozoa. Freeze-dried spermatozoa stored for 2 or 2.5 years at 4 or -80 C were transported round trip overland between Shizuoka and Hokkaido prefectures in Japan or by air between Japan and Belgium. The freeze-drying conditions consisted of primary drying at pressures of 0.04, 0.37 and 1.03 mbar and secondary drying at a pressure of 0.001 mbar. Embryos (2-cell stage) from freeze-dried spermatozoa dried at 0.04 mbar and stored at 4 C for 2 years with and without overland transportation did not develop to term. The development rates of embryos from spermatozoa stored at -80 C for up to 2 years and transported overland, by air and without transportation were 8, 1 and 28%, respectively. The development rates of embryos from spermatozoa without transportation were significantly higher than with transportation (P<0.05). These data indicate that freeze-dried spermatozoa stored at -80 C with and without transportation can retain their ability to generate viable offspring after storage for up to 2 years. However, there are limitations to be considered in the transportation of freeze-dried spermatozoa at ambient temperature.
Journal of Reproduction and Development 12/2007; 53(6):1169-74. · 1.46 Impact Factor
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ABSTRACT: Chronic ischemia is associated with alterations in genes that result in myocardial remodeling. An important biochemical basis of cardiac remodeling is generation of reactive oxygen species (ROS). A few studies have suggested that acute ischemia triggers signals for remodeling. We examined the hypothesis that targeted deletion of lectin-like oxidized-LDL receptor (LOX-1) may inhibit signals related to cardiac remodeling.
We generated LOX-1 knockout (KO) mice on C57BL/6 (wild-type mice) background, and subjected wild-type and KO mice to ischemia-reperfusion (I-R). The wild-type mice developed a marked reduction in left ventricular systolic pressure and +/-dp/dt(max) and an increase in left ventricular end-diastolic pressure following I-R, and this change was much less in the LOX-1 KO mice, indicating preservation of left ventricular function with LOX-1 deletion. There was evidence for marked oxidative stress (NADPH oxidase expression, malondialdehyde and 8-isoprostane) following I-R in the wild-type mice, much less so in the LOX-1 KO mice (P<0.01). In concert, collagen deposition (Masson's trichrome and Picro-sirius red staining) increased dramatically in the wild-type mice, but only half as much in the LOX-1 KO mice (P<0.01). Collagen staining data was corroborated with procollagen-I expression. Further, fibronectin and osteopontin expression increased in the wild-type mice, but to a much smaller extent in the LOX-1 KO mice (P<0.01).
These findings provide compelling evidence that LOX-1 is a key modulator of cardiac remodeling which starts immediately following I-R.
Cardiovascular Research 11/2007; 76(2):292-302. · 6.06 Impact Factor
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Jawahar L Mehta,
Nobuhito Sanada,
Chang Ping Hu,
Jiawei Chen,
Abhijit Dandapat,
Fumiaki Sugawara,
Hiroo Satoh,
Kazuhiko Inoue, Yosuke Kawase,
Kou-ichi Jishage,
Hiroshi Suzuki,
Motohiro Takeya,
Laura Schnackenberg,
Richard Beger,
Paul L Hermonat,
Maria Thomas,
Tatsuya Sawamura
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ABSTRACT: Atherosclerosis is associated with oxidative stress and inflammation, and upregulation of LOX-1, an endothelial receptor for oxidized LDL (oxLDL). Here, we describe generation of LOX-1 knockout (KO) mice in which binding of oxLDL to aortic endothelium was reduced and endothelium-dependent vasorelaxation preserved after treatment with oxLDL (P<0.01 versus wild-type mice). To address whether endothelial functional preservation might lead to reduction in atherogenesis, we crossed LOX-1 KO mice with LDLR KO mice and fed these mice 4% cholesterol/10% cocoa butter diet for 18 weeks. Atherosclerosis was found to cover 61+/-2% of aorta in the LDLR KO mice, but only 36+/-3% of aorta in the double KO mice. Luminal obstruction and intima thickness were significantly reduced in the double KO mice (versus LDLR KO mice). Expression of redox-sensitive NF-kappaB and the inflammatory marker CD68 in LDLR KO mice was increased (P<0.01 versus wild-type mice), but not in the double KO mice. On the other hand, antiinflammatory cytokine IL-10 expression and superoxide dismutase activity were low in the LDLR KO mice (P<0.01 versus wild-type mice), but not in the double KO mice. Endothelial nitric oxide synthase expression was also preserved in the double KO mice. The proinflammatory signal MAPK P38 was activated in the LDLR KO mice, and LOX-1 deletion reduced this signal. In conclusion, LOX-1 deletion sustains endothelial function leading to a reduction in atherogenesis in association with reduction in proinflammatory and prooxidant signals.
Circulation Research 07/2007; 100(11):1634-42. · 9.49 Impact Factor
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Ryoichi Saitoh,
Toshihiko Ohtomo,
Yoshiki Yamada,
Nobuo Kamada,
Jun-Ichi Nezu,
Naoki Kimura,
Shin-Ichi Funahashi,
Koh Furugaki,
Takeshi Yoshino, Yosuke Kawase, [......],
Masami Suzuki,
Rie Fukuda,
Masahiro Arai,
Hiroko Iwanari,
Kazuaki Takahashi,
Toshiko Sakihama,
Iwao Ohizumi,
Tatsuhiko Kodama,
Masayuki Tsuchiya,
Takao Hamakubo
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ABSTRACT: We have been investigating the functional display of multipass membrane protein such as transporter or G-protein coupled receptor on the budded baculovirus (BV). We tested the use of a viral envelope protein gp64 transgenic mouse for the direct immunization of these membrane proteins displayed on BVs. The gp64 transgenic mice showed only a weak response to virus compared to wild type BALB/c mice. Immunizing gp64 transgenic mice with the BV expressing peptide transporter PepT1, we obtained 47 monoclonal antibodies (mAbs). These mAbs were specific to the PepT1 on the pancreatic cancer cells AsPC-1 by fluorocytometric analysis and exhibited antibody-dependent cellular cytotoxicity or complement-dependent cytotoxicity to AsPC-1. We also generated 7 mAbs by immunizing gp64 transgenic mice on a CCR2-deficient background with the BV expressing chemokine receptor CCR2 together with partially purified CCR2. These mAbs possessed specific binding to CCR2 in CHO cells on fluorocytometric analysis, and exhibited neutralizing activities for ligand-dependent inhibition of cyclic AMP production. This method provides a powerful tool for the generation of therapeutic/diagnostic mAbs against membrane proteins.
Journal of Immunological Methods 05/2007; 322(1-2):104-17. · 2.20 Impact Factor
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ABSTRACT: Freeze-dried spermatozoa are capable of participating in normal embryonic development after injection into oocytes and thus useful for the maintenance of genetic materials. We recently reported that long-term preservation of freeze-dried mouse spermatozoa by conventional methods requires temperatures lower than -80 degrees C. Successful permanent preservation of mouse spermatozoa at much higher temperatures requires thorough investigation of the freeze-drying procedure. Thus, we examined the relationship between the pressure at primary drying and the preservation potential of freeze-dried mouse spermatozoa. Three different primary drying pressures were applied to evaluate the effect of pressure on freeze-dried spermatozoa under varying storage conditions and the rate of development measured. The developmental rate of embryos to the blastocyst stage from intracytoplasmic sperm injection by freeze-dried spermatozoa at pressures of 0.04, 0.37, and 1.03 mbar without storage were 59% (337/576), 71% (132/187), and 33% (99/302) respectively. When stored at 4 degrees C for 6 months, the rate was 13% (48/367), 50% (73/145), and 36% (66/182) respectively. These results show that primary drying pressure is an influential factor in the long-term preservation of freeze-dried mouse spermatozoa.
Reproduction (Cambridge, England) 05/2007; 133(4):841-6. · 3.09 Impact Factor
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Norihito Shibata,
Kou-ichi Jishage,
Makoto Arita,
Miho Watanabe, Yosuke Kawase,
Kiyotaka Nishikawa,
Yasuhiro Natori,
Hiroyasu Inoue,
Hitoshi Shimano,
Nobuhiro Yamada,
Masafumi Tsujimoto,
Hiroyuki Arai
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ABSTRACT: Supernatant protein factor (SPF) is a novel cholesterol biosynthesis-accelerating protein expressed in liver and small intestine. Here, we report on the physiological role of SPF by using Spf-deficient mice. Although plasma cholesterol levels were similar in chow-fed Spf-/- and wild-type (WT) mice, fasting significantly decreased plasma cholesterol levels in Spf-/- mice but not in WT mice. While fasting reduced hepatic cholesterol synthesis rate in WT mice, a more pronounced reduction was observed in Spf-/- mice. The expression of cholesterogenic enzymes was dramatically suppressed by fasting both in WT and Spf-/- mice. In contrast, hepatic SPF expression of WT mice was up-regulated by fasting in peroxisome proliferator-activated receptor alpha (PPAR-alpha)-dependent manner. These results indicate that in WT mice, the decrease of hepatic cholesterol synthesis under fasting conditions is at least in part compensated by SPF up-regulation. Fibrates, which function as a PPAR-alpha agonist and are widely used as hypotriglycemic drugs, reduced hepatic cholesterol synthesis and plasma cholesterol levels by approximately one-half in Spf-/- mice but not in WT mice. These findings suggest that co-administration of fibrates and an SPF inhibitor may reduce not only plasma triglyceride but also cholesterol levels, indicating that SPF is a promising hypocholesterolemic drug target.
The FASEB Journal 01/2007; 20(14):2642-4. · 5.71 Impact Factor
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ABSTRACT: Acute pharmacological inhibition of cardiac malonyl coenzyme A decarboxylase (MCD) protects the heart from ischemic damage by inhibiting fatty acid oxidation and stimulating glucose oxidation. However, it is unknown whether chronic inhibition of MCD results in altered cardiac function, energy metabolism, or ischemic cardioprotection.
Mcd-deficient mice were produced and assessed for in vivo cardiac function as well as ex vivo cardiac function, energy metabolism, and ischemic tolerance. In vivo and ex vivo cardiac function was similar in wild-type and mcd-/- mice. Ex vivo working hearts from mcd-/- and wild-type mice displayed no significant differences in rates of fatty acid oxidation, glucose oxidation, or glycolysis. However, cardiac deletion of mcd resulted in an increased expression of genes regulating fatty acid utilization that may compensate for the loss of MCD protein and likely contributes to the absence of changes in energy metabolism in the aerobic heart. Despite the lack of changes in fatty acid utilization, hearts from mcd-/- mice displayed a marked preference for glucose utilization after ischemia, which correlated with a significant cardioprotection of ischemic hearts from mcd-/- mice compared with wild-type mice.
Deletion of MCD markedly increases glucose oxidation and improves functional recovery of the heart after ischemia. As a result, chronic pharmacological inhibition of MCD may be a viable approach to treat myocardial ischemia.
Circulation 11/2006; 114(16):1721-8. · 14.74 Impact Factor
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ABSTRACT: Left ventricular (LV) remodeling after myocardial infarction is associated with hypertrophy of surviving myocytes and represents a major process that leads to heart failure. One of the intrinsic histone acetyltransferases, p300, serves as a coactivator of hypertrophy-responsive transcriptional factors such as a cardiac zinc finger protein GATA-4 and is involved in its hypertrophic stimulus-induced acetylation and DNA binding. However, the role of p300-histone acetyltransferase activity in LV remodeling after myocardial infarction in vivo is unknown.
To solve this problem, we have generated transgenic mice overexpressing intact p300 or mutant p300 in the heart. As the result of its 2-amino acid substitution in the p300-histone acetyltransferase domain, this mutant lost its histone acetyltransferase activity and was unable to activate GATA-4-dependent transcription. The two kinds of transgenic mice and the wild-type mice were subjected to myocardial infarction or sham operation at the age of 12 weeks. Intact p300 transgenic mice showed significantly more progressive LV dilation and diminished systolic function after myocardial infarction than wild-type mice, whereas mutant p300 transgenic mice did not show this.
These findings demonstrate that cardiac overexpression of p300 promotes LV remodeling after myocardial infarction in adult mice in vivo and that histone acetyltransferase activity of p300 is required for these processes.
Circulation 03/2006; 113(5):679-90. · 14.74 Impact Factor
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ABSTRACT: In the present study, we established transgenic mice overexpressing Del1, a ligand of integrins, to examine the effect of overexpression of Del1 on vascular morphogenesis. In the wild-type mouse, mesenteric vessels are shaped like rakes consisting of a long stalk and short branches at the periphery. In contrast, those in transgenic mice showed typical dendritic architecture consisting of a few large primary branches with smaller spreading branches. The phenotype of mice overexpressing Del1 suggests the existence of a tissue-specific mechanism for branching morphogenesis in the mesentery.
The Anatomical Record Part A Discoveries in Molecular Cellular and Evolutionary Biology 01/2006; 287(2):1165-75.
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ABSTRACT: Freeze-dried mouse spermatozoa are capable of participating in normal embryonic development after injection into oocytes. When the freeze-dried spermatozoa are used as a method for storage of genetic materials, however, it is essential to assure the relevance of long-term preservation over several decades or centuries. Thus, we applied the theory of accelerated degradation kinetics to freeze-dried mouse spermatozoa. Thermal denaturation kinetics were determined based on Arrhenius plots derived from transition-state theory analysis at three elevated temperatures: 30, 40, and 50 degrees C. Accelerated degradation kinetics were calculated by extrapolation of Arrhenius plots. This theory also is being applied to the long-term stability of drugs. The estimated rate of development to the blastocyst stage at 3 and 6 mo and at 1, 10, and 100 yr of sperm storage at 4 degrees C were 21.60%, 7.91%, 1.00%, 0%, and 0%, respectively. At -80 degrees C, estimated development rates to the blastocyst stage that would be expected after 100 yr of storage did not decline significantly. In addition, after 3 or 6 mo of storage at 4 or -80 degrees C, preimplantation development of the embryos derived from intracytoplasmic sperm injection (ICSI) was examined. The actual developmental rates to the blastocyst stage from ICSI by freeze-dried sperm stored for 3 mo at 4 and -80 degrees C were 21% and 62%, respectively, and the rates for such sperm stored for 6 mo were 13% and 59%, respectively. These results indicate that the determination of accelerated degradation kinetics can be applied to the preservation of freeze-dried mouse spermatozoa. Furthermore, for long-term preservation, freeze-dried mouse spermatozoa appear to require being kept at lower than -80 degrees C.
Biology of Reproduction 04/2005; 72(3):568-73. · 4.01 Impact Factor
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ABSTRACT: Doxorubicin is an anti-tumor agent that represses cardiac-specific gene expression and induces myocardial cell apoptosis. Doxorubicin depletes cardiac p300, a transcriptional coactivator that is required for the maintenance of the differentiated phenotype of cardiac myocytes. However, the role of p300 in protection against doxorubicin-induced apoptosis is unknown. Transgenic mice overexpressing p300 in the heart and wild-type mice were subjected to doxorubicin treatment. Compared with wild-type mice, transgenic mice exhibited higher survival rate as well as more preserved left ventricular function and cardiac expression of alpha-sarcomeric actin. Doxorubicin induced myocardial cell apoptosis in wild-type mice but not in transgenic mice. Expression of p300 increased the cardiac level of bcl-2 and mdm-2, but not that of p53 or other members of the bcl-2 family. These findings demonstrate that overexpression of p300 protects cardiac myocytes from doxorubicin-induced apoptosis and reduces the extent of acute heart failure in adult mice in vivo.
Biochemical and Biophysical Research Communications 04/2004; 315(3):733-8. · 2.48 Impact Factor
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ABSTRACT: Cryopreservation of mouse spermatozoa has been widely applied for maintenance of transgenic and knockout lines. However, the fertility of cryopreserved spermatozoa from some inbred strains such as C57BL/6 and BALB/c is extremely poor. We have recently reported that a partial zona-pellucida incision by piezo-micromanipulator (ZIP) significantly improves the fertilization rate and subsequent embryonic development after in vitro fertilization (IVF) using cryopreserved C57BL/6 transgenic mouse spermatozoa and that inbred C57BL/6 mice could be produced by intracytoplasmic sperm injection (ICSI). These findings prompted us to compare the efficiency of fertilization and subsequent embryonic development between ICSI and IVF with ZIP (ZIP/IVF) using cryopreserved spermatozoa. In conventional IVF, BALB/cA, C57BL/6J, and B6C3F1 cryopreserved spermatozoa fertilized 19%, 0%, and 51% of oocytes, respectively. The fertilization rates of manipulated oocytes by ICSI versus ZIP/IVF using cryopreserved BALB/cA spermatozoa were 52% versus 68%, cryopreserved C57BL/6J spermatozoa were 43% versus 63%, and cryopreserved B6C3F1 spermatozoa were 58% versus 82%, respectively. In these strains, fertilization rates for ZIP/IVF were significantly higher (P < 0.05) than for other techniques. However, embryonic development to term for oocytes fertilized by cryopreserved spermatozoa was not significantly different between ZIP/IVF and ICSI in C57BL/6J and B6C3F1. The overall efficiency of mouse production in ZIP/IVF was higher than for ICSI and conventional IVF in C57BL/6J and B6C3F1. Furthermore, ZIP/IVF required approximately 3.3 times less manipulation time than did ICSI. Our results indicate that ZIP is a useful assisted reproductive technique for IVF of ova by cryopreserved spermatozoa and improves production in some mouse strains.
Contemporary topics in laboratory animal science / American Association for Laboratory Animal Science 01/2004; 43(1):21-5. · 0.82 Impact Factor
