Weight loss reduces adipose tissue cathepsin S and its circulating levels in morbidly obese women.
BACKGROUND
Human adipose tissue produces several adipokines, including the newly identified protein cathepsin S (CTSS), a cysteine protease involved in the pathogenesis of atherosclerosis. Obesity is characterized by high levels of CTSS in the circulation and in sc white adipose tissue (scWAT).


OBJECTIVE
We investigated the effect of surgery-induced weight loss on circulating CTSS and its protein expression in scWAT.


METHODS
Fifty morbidly obese women before and 3 months after surgery and 10 healthy lean women were studied. We analyzed the relationships between circulating CTSS and clinical and biological parameters. Immunohistochemistry of the CTSS protein variations in scWAT was performed.


RESULTS
Weight loss decreased by 42% (P < 0.0001) the circulating CTSS levels, which correlated with changes in body weight (P = 0.03). We observed a significant decrease in CTSS enzymatic activity by 25% after weight loss (P = 0.001). Adipose tissue CTSS content was reduced by 30% (P = 0.002) after surgery. The variations in CTSS expression in scWAT after surgery correlated with changes in circulating CTSS serum levels (P = 0.03). Most of the correlations between CTSS and clinical and biological parameters disappeared after adjustment for body mass index, emphasizing the strong link between CTSS and corpulence in humans.


CONCLUSIONS
Changes in CTSS scWAT might contribute to serum variations in CTSS during weight loss. The decrease in CTSS concentrations in the circulation may contribute to vascular improvement in obese subjects after weight loss.
Taleb
Soraya
S
Institut National de la Santé et de la Recherche Médicale U755, Nutrition Department, Hôtel Dieu, Place du parvis Notre Dame, 75004 Paris, France.
Cancello
Raffaella
R
Poitou
Christine
C
Rouault
Christine
C
Sellam
Philippe
P
Levy
Patrick
P
Bouillot
Jean-Luc
JL
Coussieu
Christiane
C
Basdevant
Arnaud
A
Guerre-Millo
Michèle
M
Lacasa
Danièle
D
Clement
Karine
K
D000273:Adipose Tissue / Q000201:enzymology*; D000328:Adult; D001808:Blood Vessels / Q000201:enzymology; D015992:Body Mass Index; D001835:Body Weight; D002403:Cathepsins / Q000097:blood / Q000378:metabolism*; D018929:Cell Culture Techniques; D005260:Female; D006801:Humans; D009767:Obesity, Morbid / Q000097:blood* / Q000503:physiopathology / Q000601:surgery*; D012016:Reference Values; D013851:Thinness; D015431:Weight Loss
D002403:Cathepsins; C028217:cathepsin S