Surfactant protein D of the innate immune defence is inversely associated with human obesity and SP-D deficiency infers increased body weight in mice.
Surfactant protein D (SP-D) is a key regulator of pathogen-induced inflammation. SP-D is further involved in lipid homeostasis in mouse lung and circulation and recent data have demonstrated that the body mass index (BMI; in kg/m(2)) is influenced by genes in common with SP-D. The objective of the present study was to describe the association between serum SP-D and weight, waist circumference or BMI, and furthermore to observe body weight development in SP-D-deficient (Spd-/-) mice. As a part of the Danish population-based twin study (GEMINAKAR) on the metabolic syndrome, we analysed 1476 Danish twins for serum SP-D and investigated associations with weight, waist circumference and BMI by multiple regression analysis. Serum SP-D was significantly and inversely associated with weight (P = 0.001) and waist circumference in men (P < 0.001) and to BMI in both genders (P = 0.039 women, P < 0.001 men). The age-dependent increase in serum SP-D was most prominent in lean persons (BMI < 20). Spd-/- mice and wild-type mice were subjected to a feeding study and body weights were recorded in a time course over 24 weeks. Spd-/- mouse weight gain was significantly increased, with 90 mg/week (P < 0.0001) in males on normal chow. Fat percentage was significantly increased by 17% in the Spd-/- male mice (P = 0.003). We conclude, that there is an association between low levels or absent SP-D and obesity.
Sorensen
G L
GL
Medical Biotechnology Center, University of Southern Denmark, Odense, Denmark. glsorensen@health.sdu.dk
Hjelmborg
J V B
JV
Leth-Larsen
R
R
Schmidt
V
V
Fenger
M
M
Poulain
F
F
Hawgood
S
S
Sørensen
T I A
TI
Kyvik
K O
KO
Holmskov
U
U
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008875:Middle Aged; D009765:Obesity / Q000235:genetics / Q000276:immunology*; D037663:Pulmonary Surfactant-Associated Protein D / Q000172:deficiency* / Q000235:genetics; D015430:Weight Gain / Q000235:genetics / Q000276:immunology*
D037663:Pulmonary Surfactant-Associated Protein D