Collapsin response mediator protein 2, CRMP2, has been identified as an intracellular signaling mediator for Semaphorin 3A (Sema3A). CRMP2 plays a key role in axon guidance, dendritic morphogenesis, and cell polarization. It has been also implicated in a variety of neurological and psychiatric disorders. However, the in vivo functions of CRMP2 remain unknown. We generated CRMP2 gene-deficient (crmp2 À/À ) mice. The crmp2 À/À mice showed irregular development of dendritic spines in cortical neurons. The density of dendritic spines was reduced in the cortical layer V pyramidal neurons of crmp2 À/À mice as well as in those of sema3A À/À and crmp1 À/À mice. However, no abnormality was found in dendritic patterning in crmp2 À/À compared to wild-type (WT) neurons. The level of CRMP1 was increased in crmp2, but the level of CRMP2 was not altered in crmp1 À/À compared to WT cortical brain lysates.Dendritic spine density and branching were reduced in double-heterozygous sema3A +/À ;crmp2 +/À and sema3A +/À ;crmp1 +/À mice. The phenotypic defects had no genetic interaction between crmp1 and crmp2. These findings suggest that both CRMP1 and CRMP2 mediate Sema3A signaling to regulate dendritic spine maturation and patterning, but through overlapping and distinct signaling pathways.
Kaempferia parviflora Wall. Ex Baker (KP) has been used as a folk medicine in Laos and Thailand to lower blood glucose levels, improve blood flow, and increase vitality. This study investigated the preventive effects of KP on obesity and its downstream symptoms (various metabolic disorders) using Tsumura, Suzuki, Obese Diabetes (TSOD) mice, a multifactorial genetic disease animal model in which metabolic diseases develop spontaneously, similar to metabolic syndrome in humans, and Tsumura, Suzuki, Non-Obesity (TSNO) mice as the corresponding control mice. When feed that was mixed with KP (1 or 3%) was given ad libitum to TSOD and TSNO mice for 8 weeks, body weight increase, visceral fat accumulation, lipid metabolism abnormalities, hyperinsulinemia, glucose intolerance, insulin resistance, hypertension, and peripheral neuropathy were suppressed in TSOD mice, but no marked differences were observed in TSNO mice. Because KP had preventive effects on metabolic diseases, including antiobesity effects, only in obese animals, we propose that KP will be extremely valuable as a medicine or component of food in alternative health care.
Visceral fat accumulation induces insulin resistance, abnormal glucose metabolism, abnormal lipid metabolism and hypertension. Furthermore, even when these individual diseases are present in only a mild form, if more than one of these diseases is present, this may induce development of arteriosclerosis or ischemic cardiovascular diseases.1,2) For these reasons, it is important that some form of medical therapy including exercise and diet therapy be devised to prevent the development of obesity and various metabolic disorders.Bofutsushosan, a traditional Japanese herbal medicine comprising 18 crude drugs (Table 1), has been an effective treatment for obesity, constipation and hypertension. Bofutsushosan was shown to reduce body weight and improve impaired glucose tolerance in a clinical trial.3) In addition, several pharmacological studies have reported on its ability to counter obesity, [4][5][6][7][8] fatty liver, 9,10) and arteriosclerotic diseases. 11)In the present study, we investigated the preventive effects of Bofutsushosan on various disease states (diabetes, hyperlipidemia, hypertension and diabetic peripheral neuropathy) that accompany metabolic disorders, focusing on visceral fat accumulation using a model animal, TSOD (Tsumura, Suzuki, Obese, Diabetes) mice, which are known to develop disease states similar to human metabolic disorders including glucose intolerance, hyperlipidemia, hypertension, hyperinsulinemia and peripheral neuropathy. [12][13][14] MATERIALS AND METHODS Experimental AnimalsWe used male TSOD mice aged 3 weeks. As a control animal, male TSNO (Tsumura, Suzuki, Non-Obesity) mice 12) aged 3 weeks were used as these animals do not develop obesity and various metabolic disorders. All mice were obtained from the Institute for Animal Reproduction (Ibaragi Prefecture). The animals were housed in an animal room under the following conditions: room temperature of 23Ϯ2°C, relative humidity of 55Ϯ10% and 12 h of light per day. In the 1-week acclimation period, the animals were given ad libitum powder feed MF (Oriental Yeast Co., Ltd.) and water. Following this period, the powder feed was switched to the study feed containing the test drug, and the animals were kept for further 8 weeks. We certify that all ap- Clinical and Biomedical Sciences, Showa Pharmaceutical University; 3-3165 Higashi-tamagawagakuen, Machida, Tokyo 142-8501, Japan. Received January 23, 2008; accepted May 7, 2008; published online May 8, 2008 Visceral fat accumulation has been reported as the most important risk factor for the development of various metabolic disorders. In this study, the preventive effects of Bofutsushosan, a Japanese Kampo preparation, on obesity and various metabolic disorders were investigated focusing on visceral fat accumulation using Tsumura, Suzuki, Obese, Diabetes (TSOD) mice, which showed significant accumulation of visceral fat, and developed metabolic disorders including glucose intolerance, hyperlipidemia, hypertension and hyperinsulinemia. At 2 months after initiation of the study, the c...
The purpose of this study was to test the hypothesis that obese diabetic mice exhibit marked skin fragility, which is caused by increased oxidative stress and increased matrix metalloproteinase (MMP) gene expression in the subcutaneous adipose tissue. Scanning electron microscopy of skin samples from Tsumura-Suzuki obese diabetic (TSOD) mice revealed thinner collagen bundles, and decreased density and convolution of the collagen fibres. Furthermore, skin tensile strength measurements confirmed that the dorsal skin of TSOD mice was more fragile to tensile force than that of non-obese mice. The mRNA expressions of heme oxygenase 1 (Hmox1), a marker of oxidative stress, Mmp2 and Mmp14 were increased in the adipose tissue of TSOD mice. Antioxidant experiments were subsequently performed to determine whether the changes in collagen fibres and skin fragility were caused by oxidative stress. Strikingly, oral administration of the antioxidant dl-α-tocopherol acetate (vitamin E) decreased Hmox1, Mmp2 and Mmp14 mRNA expressions, and improved the skin tensile strength and structure of collagen fibres in TSOD mice. These findings suggest that the skin fragility in TSOD mice is associated with dermal collagen damage and weakened tensile strength, and that oxidative stress and MMP overexpression in the subcutaneous adipose tissue may, at least in part, affect dermal fragility via a paracrine pathway. These observations may contribute to novel clinical interventions, such as dietary supplementation with antioxidants or application of skin cream containing antioxidants, which may overcome skin fragility in obese patients with diabetes.
An animal model is needed to study the pathophysiology of wound infections; however, an animal model that is reproducible and clinically relevant has not previously been available. In addition, an animal model of wound colonization generated in a manner similar to the wound infection model would be useful. Here, we describe new animal models of the wound infection continuum for the characterization of essential host-pathogen relationships. We determined the conditions needed to establish rat models of stable wound colonization and infection, without the use of disturbing factors (e.g., foreign bodies or induction of diabetes mellitus). We found that the age of the rats, bacterial inoculum size, and wound location were important elements in generating reproducible, obvious, spreading wound infections. We inoculated approximately 6-month-old rats with 2.06 × 10(9) or 4.12 × 10(9) colony-forming units of Pseudomonas aeruginosa to generate the wound colonization and wound infection models, respectively. Wounds were made 2 cm cranial to the greater trochanter. These clinically relevant and highly reproducible animal models can be used to investigate the mechanisms of wound infection and monitor the effect of therapeutic agents in vivo.
The extracts of Salacia reticulata (Salacia extract), a plant that has been used for the treatment of early diabetes, rheumatism and gonorrhea in Ayurveda, have been shown to have an anti-obesity effect and suppress hyperglycemia. In this study, the effects of Salacia extract on various symptoms of metabolic disorder were investigated and compared using these TSOD mice and non-obese TSNO mice. Body weight, food intake, plasma biochemistry, visceral and subcutaneous fat (X-ray and CT), glucose tolerance, blood pressure and pain tolerance were measured, and histopathological examination of the liver was carried out. A significant dose-dependent decline in the gain in body weight, accumulation of visceral and subcutaneous fat and an improvement of abnormal glucose tolerance, hypertension and peripheral neuropathy were noticed in TSOD mice. In addition, hepatocellular swelling, fatty degeneration of hepatocytes, inflammatory cell infiltration and single-cell necrosis were observed on histopathological examination of the liver in TSOD mice. Salacia extract markedly improved these symptoms upon treatment. Based on the above results, it is concluded that Salacia extract has remarkable potential to prevent obesity and associated metabolic disorders including the development of metabolic syndrome.
SummaryAging is accelerated, at least in part, by pathological condition such as metabolic syndrome (MetS), and various molecular pathways such as oxidative stress are common mediators of aging and MetS. We previously developed the aging-like skin model by single ultraviolet (UV) irradiation on the MetS model mice. Recent studies revealed that mineralocorticoid receptor (MR) signaling plays a pivotal role for various tissue inflammation and damages in MetS. Although previous studies reported that MR is expressed in the skin and that overexpression of MR in the skin resulted in the skin atrophy, the physiological or pathological functions of MR in the skin are not fully elucidated. Here, we show the involvement of MR signaling in the aging-like skin changes in our own model. Elevations of oxidative stress and inflammation markers were observed in the MetS mice, and the UV-evoked aging-like skin damages were attenuated by topical antioxidant. MR expression was higher in the MetS mouse skin, and notably, expression of its effecter gene Sgk1 was significantly upregulated in the aging-like skin in the UV-irradiated MetS mice. Furthermore, topical application of MR antagonist spironolactone suppressed Sgk1 expression, oxidative stress, inflammation, and the aging-like changes in the skin. The 2-week UV onto the non-MetS mice, the more usual photoaging model, resulted in the skin damages mostly equivalent to the MetS mice with single UV, but they were not associated with upregulation of MR signaling. Our studies suggested an unexpected role of MR signaling in the skin aging in MetS status.
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