TY  - JOUR
A1  - Hauffe, Robert
A1  - Rath, Michaela
A1  - Schell, Mareike
A1  - Ritter, Katrin
A1  - Kappert, Kai
A1  - Deubel, Stefanie
A1  - Ott, Christiane
A1  - Jähnert, Markus
A1  - Jonas, Wenke
A1  - Schürmann, Annette
A1  - Kleinridders, André
T1  - HSP60 reduction protects against diet-induced obesity by modulating energy metabolism in adipose tissue
JF  - Molecular Metabolism
N2  - Objective
Insulin regulates mitochondrial function, thereby propagating an efficient metabolism. Conversely, diabetes and insulin resistance are linked to mitochondrial dysfunction with a decreased expression of the mitochondrial chaperone HSP60. The aim of this investigation was to determine the effect of a reduced HSP60 expression on the development of obesity and insulin resistance.

Methods
Control and heterozygous whole-body HSP60 knockout (Hsp60+/−) mice were fed a high-fat diet (HFD, 60% calories from fat) for 16 weeks and subjected to extensive metabolic phenotyping. To understand the effect of HSP60 on white adipose tissue, microarray analysis of gonadal WAT was performed, ex vivo experiments were performed, and a lentiviral knockdown of HSP60 in 3T3-L1 cells was conducted to gain detailed insights into the effect of reduced HSP60 levels on adipocyte homeostasis.

Results
Male Hsp60+/− mice exhibited lower body weight with lower fat mass. These mice exhibited improved insulin sensitivity compared to control, as assessed by Matsuda Index and HOMA-IR. Accordingly, insulin levels were significantly reduced in Hsp60+/− mice in a glucose tolerance test. However, Hsp60+/− mice exhibited an altered adipose tissue metabolism with elevated insulin-independent glucose uptake, adipocyte hyperplasia in the presence of mitochondrial dysfunction, altered autophagy, and local insulin resistance.

Conclusions
We discovered that the reduction of HSP60 in mice predominantly affects adipose tissue homeostasis, leading to beneficial alterations in body weight, body composition, and adipocyte morphology, albeit exhibiting local insulin resistance.
KW  - Mitochondria
KW  - Stress response
KW  - Obesity
KW  - Glucose homeostasis
KW  - Insulin resistance
KW  - Adipose tissue
Y1  - 2021
U6  - https://doi.org/10.1016/j.molmet.2021.101276
SN  - 2212-8778
VL  - 53
SP  - 1
EP  - 14
PB  - Elsevier
CY  - Amsterdam, Niederlande
ER  - 
TY  - JOUR
A1  - Laeger, Thomas
A1  - Castano-Martinez, Teresa
A1  - Werno, Martin W.
A1  - Japtok, Lukasz
A1  - Baumeier, Christian
A1  - Jonas, Wenke
A1  - Kleuser, Burkhard
A1  - Schürmann, Annette
T1  - Dietary carbohydrates impair the protective effect of protein restriction against diabetes in NZO mice used as a model of type 2 diabetes
JF  - Diabetologia : journal of the European Association for the Study of Diabetes (EASD)
N2  - Aims/hypothesis Low-protein diets are well known to improve glucose tolerance and increase energy expenditure. Increases in circulating fibroblast growth factor 21 (FGF21) have been implicated as a potential underlying mechanism. Methods We aimed to test whether low-protein diets in the context of a high-carbohydrate or high-fat regimen would also protect against type 2 diabetes in New Zealand Obese (NZO) mice used as a model of polygenetic obesity and type 2 diabetes. Mice were placed on high-fat diets that provided protein at control (16 kJ%; CON) or low (4 kJ%; low-protein/high-carbohydrate [LP/HC] or low-protein/high-fat [LP/HF]) levels. Results Protein restriction prevented the onset of hyperglycaemia and beta cell loss despite increased food intake and fat mass. The effect was seen only under conditions of a lower carbohydrate/fat ratio (LP/HF). When the carbohydrate/fat ratio was high (LP/HC), mice developed type 2 diabetes despite the robustly elevated hepatic FGF21 secretion and increased energy expenditure. Conclusion/interpretation Prevention of type 2 diabetes through protein restriction, without lowering food intake and body fat mass, is compromised by high dietary carbohydrates. Increased FGF21 levels and elevated energy expenditure do not protect against hyperglycaemia and type 2 diabetes per se.
KW  - Energy expenditure
KW  - FGF21
KW  - Hyperglycaemia
KW  - Insulin resistance
KW  - NZO
KW  - Obesity
KW  - Protein restriction
Y1  - 2018
U6  - https://doi.org/10.1007/s00125-018-4595-1
SN  - 0012-186X
SN  - 1432-0428
VL  - 61
IS  - 6
SP  - 1459
EP  - 1469
PB  - Springer
CY  - New York
ER  -