Background: Bone marrow-derived mesenchymal stem cells (BM-MSCs) and adipose tissue-derived mesenchymal stem cells (AT-MSCs) are potential cellular sources of therapeutic stem cells. MSCs are a multipotent population of cells capable of differentiating into a number of mesodermal lineages. Treatment using MSCs appears to be a helpful approach for structural restoration in regenerative medicine. Correct identification of these cells is necessary, but there is inadequate information on the MSC profile of cell surface markers and mRNA expression in dogs. In this study, we performed molecular characterization of canine BM-MSCs and AT-MSCs using immunological and mRNA expression analysis. Results: Samples were confirmed to be multipotent based on their osteogenic and adipogenic differentiation. And these cells were checked as stem cell, hematopoietic and embryonic stem cell (ESC) markers by flow cytometry. BM- and AT-MSCs showed high expression of CD29 and CD44, moderate expression of CD90, and were negative for CD34, CD45, SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81. SSEA-1 was expressed at very low levels in AT-MSCs. Quantitative real-time PCR (qRT-PCR) revealed expression of Oct3/4, Sox2, and Nanog in BM- and AT-MSCs. There was no significant difference in expression of Oct3/4 and Sox2 between BM-MSCs and AT-MSCs. However, Nanog expression was 2.5-fold higher in AT-MSCs than in BM-MSCs. Using immunocytochemical analysis, Oct3/4 and Sox2 proteins were observed in BM- and AT-MSCs. Conclusion: Our results provide fundamental information to enable for more reproducible and reliable quality control in the identification of canine BM-MSCs and AT-MSCs by protein and mRNA expression analysis.

In dogs, occurrence of lipid metabolism disorders such as obesity and diabetes mellitus has increased markedly in recent years. Hyperlipidemia has been regarded as a common characteristic for obese animals and hyperlipidemic condition may be associated with inflammation, oxidative stress and lipid composition changes. In this study, we investigated the changes in plasma cholesterol and triglyceride (TG) profiles and metabolite concentrations in 24 dogs (young group: 0-7 years old, n = 12, aged group: 8-13 years old, n = 12). Plasma adiponectin (ADN) concentrations were significantly lower in aged dogs than those in young dogs (mean ± SD, 17.2 ± 10.0 μg mL^-1 vs 29.3 ± 12.5 μg mL^-1, respectively; P <0.05). Although there were no significant differences statistically, aged dogs showed significantly higher plasma alpha1- acid glycoprotein (alpah1-AG) levels compared to those in young dogs. Plasma cholesterol lipoprotein and TG lipoprotein were divided into four fractions by biphasic agarose gel electrophoresis technique. The levels of the third TG-lipoprotein fraction from the positive pole (TG Fraction 3) were significantly higher in aged dogs than in young dogs (mean ± SD, 143.0 ± 109.3 mg dL^-1 vs 55.2 ± 31.3 mg dL^-1, respectively; P <0.05). On the correlation coefficient analysis by Peason’s method, moderate positive correlations were seen between the age and TG (r = 0.446, P = 0.029), TG Fraction 3 (r = 0.516, P = 0.010), malondialdehyde (r = 0.146, P = 0.043), alpha-1 AG (r = 0.448, P = 0.028) levels, respectively. Moderate negative correlations were seen the age and total cholesterol (TC) Fraction 2 (r = -0.446, P = 0.029), glucose (r = -0.637, P = 0.001), ADN (r = -0.408, P = 0.048), respectively. Present data suggest biochemical characteristics of lipid metabolism disorder may be affected by aging in dogs.

Accumulated visceral and subcutaneous fat masses were measured with computed tomography (CT) in cats with various body condition scores (BCS) from 5/9 to 9/9. BCS does not always reflect visceral fat accumulation which induces pro-inflammatory reactions. Obese cats with accumulated visceral fat showed low plasma adiponectin and high serum amyloid A (SAA) concentrations, an inflammatory marker. Based on the above results, new diagnostic criteria for obesity disease were established as follows. For overweight cats with high BCS of >7/9, showing two or more of the following three symptoms, low adiponectin concentrations, hyperlipidemia, and high SAA concentrations, categorizes them as having obesity disease. Cats with BCS 6/9–9/9, without inflammatory reactions, were classified as simple obesity, which is similar to metabolically healthy obesity (MHO) defined in human medicine. Simple obesity group showed significantly higher adiponectin concentrations than those in control group. The obesity disease group showed significantly higher plasma triglyceride (TG) and SAA concentrations and lower concentrations of adiponectin than the control group. Moreover, plasma glucose and malondialdehyde (MDA) concentrations in the obesity disease group were higher than those in healthy control group, although the differences were not statistically significant. Establishing criteria for obesity disease based on visceral fat accumulation and inflammation markers levels contributes to early and correct diagnosis of obesity in cats.

Obesity and overweight have been frequently observed in dogs and cats in recent years as in humans. The compositions of fatty acids (FAs) in the accumulated lipids in tissues of obese animals may have important roles in the process and mechanisms related to the onset of metabolic disorders. The purpose of this study was to evaluate the effects of a high fat (HF) diet, which contained a higher proportion of saturated FAs, on FA metabolism and distribution in obese cats. Cats (N = 12) were divided into control diet group (crude fat; 16.0 %) (n = 4) or a high fat (HF) diet group (crude fat; 23.9 %) (n = 8). The HF diet contained up to 60 % of calories from fat and was rich in stearic acid. Blood samples were collected at 0, 2, 4 and 6 weeks after the feeding. Adipose and liver tissues were collected at the 6th week after feeding. We performed analysis of histological findings and fatty acid composition in serum and tissues. Body weights of the cats significantly increased in the HF group. The increased activities of hepatic enzymes and the accumulation of lipid droplets were found in hepatocytes in the HF group at the 6th week after feeding. In this study, the stearic acid (C18:0)-rich HF diet contained less oleic acid (C18:1n-9) and more linoleic acid (C18:2n-6) than the control. However, the composition of oleic acid in the liver was higher, and those of stearic acid and linoleic acid were lower in the HF group at the 6th week after feeding. The higher oleic acid:stearic acid ratio suggests an increase in the conversion from saturated FA to mono-unsaturated FAs, which may reflect the hepatic storage of FAs as a relatively harmless form. The stearic acid-rich HF diet increased hepatic lipid accumulation accompanied by the increased of hepatic oleic acid, increased serum oleic acid and activation of hepatic enzymes. These findings could be an important sign of early stages of dyslipidemia and hepatic damage. Also, the higher oleic acid:stearic acid ratio might be related to the increased activity of SCD-1, which suggests that the stearic acid-rich HF diet evoked hepatic lipogenesis in the feline liver.