Lipogenic gene expression in abdominal adipose and liver tissues of diet-induced overweight cats

Effects of Age on Inflammatory Profiles and Nutrition/Energy Metabolism in Domestic Cats

BACKGROUND

Animals tend to increase in body weight and body condition score (BCS) with aging. Serum diagnostic markers related to energy metabolism may show changes even in healthy cats with aging.

MATERIALS AND METHODS

Seventy domestic cats were recruited for this study. Based upon the modified AAFP-AAHA Feline Life Stage Guidelines, animals were divided into six groups: Junior (7 months-2 years), Prime (3 -6 years), Mature (7-10 years), Senior (11-14 years), Geriatric-obese (15 years ≤) and Geriatric-thin (15 years ≤). Their body condition scores (BCS) ranged from 3/9 to 9/9. Changes in metabolites, inflammatory markers, hormone concentrations and enzyme activities related to energy metabolism were investigated in serum of 70 domestic cats of various ages.

RESULTS

Serum glucose (GLU) concentrations in the Mature, Senior, and Geriatric-obese groups were significantly higher than those in the Junior group. Serum amyloid A (SAA) concentrations in the Geriatric-thin group were significantly increased compared with the Junior group. SAA concentrations in the Geriatric-obese group tended to increase although there were no statistically significant differences. In the Mature, Senior, Geriatric-obese and Geriatric-thin groups, malate dehydrogenase/lactate dehydrogenase (M/L) ratio, an energy metabolic indicator, tended to decrease compared with the Junior group. In the Senior group, triglyceride (TG) concentrations were significantly increased compared with the Junior group. In the Geriatric-obese and Geriatric-thin groups, blood urea nitrogen (BUN) concentrations were significantly increased compared with the Junior group. In the Geriatric-obese group, albumin (ALB) concentrations were decreased compared with the Junior group.

CONCLUSION

Aged domestic cats tend to increase in body weight and BCS. In addition, serum GLU, TG, SAA, and BUN concentrations increased and serum ALB concentrations and M/L ratio decreased. These diagnostic markers may be useful to detect small changes related to energy metabolism with aging that may cause obesity with light inflammation in healthy cats.

Gene expressions of de novo hepatic lipogenesis in feline hepatic lipidosis

Objectives

The aim of this study was to evaluate if de novo hepatic lipid synthesis contributes to fatty acid overload in the liver of cats with feline hepatic lipidosis (FHL).

Methods

Lipogenic gene expression of peroxisome proliferator-activated receptor-alpha (PPAR-α), peroxisome proliferator-activated receptor-gamma (PPAR-γ), fatty acid synthase (FASN) and sterol regulatory element-binding factor (SREBF1) were evaluated using quantitative RT-PCR in liver tissue of six cats with FHL and compared with the liver tissue of eight healthy cats.

Results

In liver tissue, PPAR-α, PPAR-γ and FASN mRNA expression levels were not significantly different (P >0.12, P >0.89 and P >0.5, respectively) in the FHL group compared with the control group. SREBF1 gene expression was downregulated around 10-fold in the FHL group vs the control group (P = 0.039).

Conclusions and relevance

The downregulation of SREBF1 in the liver tissue of cats with FHL does not support the hypothesis that de novo lipogenesis in the liver is an important pathway of fatty acid accumulation in FHL.

Feline Hepatic Lipidosis

Feline hepatic lipidosis (FHL) is a common and potentially fatal liver disorder. Although the pathophysiologic mechanisms of FHL remain elusive, there is an imbalance between the influx of fatty acids from peripheral fat stores into the liver, de novo liposynthesis, and the rate of hepatic oxidation and dispersal of hepatic TAG via excretion of very-low density lipoproteins. The diagnosis of FHL is based on anamnestic, clinical, and clinicopathologic findings, associated with diagnostic imaging of the liver, and cytology, or histological examination of liver biopsies. Fluid therapy, electrolyte correction and adequate early nutrition are essential components of the therapy for FHL.

Current Topics in Canine and Feline Obesity

The domestication and urbanization of dogs and cats has dramatically altered their environment and behavior. Human and pet obesity is a global concern, particularly in developed countries. An increased incidence of chronic disease is associated with obesity secondary to low-grade systemic inflammation. This article reviews current research into the genetic, dietary, and physiologic factors associated with obesity, along with use of "omics" technology to better understand and characterize this disease.