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Measuring the Rate of Lipolysis in Ex Vivo Murine Adipose Tissue and Primary Preadipocytes Differentiated In Vitro
Published on: March 17, 2023
Cysteine cathepsin S processes leptin, inactivating its biological activity
Marcela Oliveira1, Diego M Assis, Thaysa Paschoalin
1Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo 669, São Paulo, São Paulo 04039-032, Brazil.
The Journal of Endocrinology
|June 2, 2012
Summary
Cysteine cathepsins, particularly cathepsin S, degrade leptin in white adipose tissue. This process inactivates leptin’s functions, suggesting cathepsins regulate leptin activity.
Area of Science:
- Biochemistry
- Endocrinology
- Molecular Biology
Background:
- Leptin, a 16 kDa adipocyte-produced hormone, regulates appetite, energy balance, and inflammatory processes.
- The role of proteolytic enzymes in leptin processing remains incompletely understood.
- White adipose tissue (WAT) exhibits significant peptidase activity.
Purpose of the Study:
- To investigate the degradation of human leptin by cysteine cathepsins.
- To identify specific cysteine cathepsins involved in leptin processing.
- To determine the functional consequences of leptin degradation by cathepsins.
Main Methods:
- Assessing cysteine peptidase expression and activity in WAT.
- Incubating human leptin with recombinant human cathepsins B, K, L, and S.
- Utilizing mass spectrometry to identify leptin degradation products.
- Employing Matrigel assays to evaluate the angiogenic potential of leptin fragments.
- Intracerebroventricular administration in Wistar rats to assess effects on food intake.
Main Results:
- High cysteine peptidase expression and activity were found in WAT, capable of degrading leptin.
- Cathepsin S demonstrated the highest catalytic activity against human leptin among tested enzymes.
- Leptin fragments generated by cathepsin S digestion lacked angiogenic activity.
- These fragments did not inhibit food intake in Wistar rats.
Conclusions:
- Cysteine cathepsins, especially cathepsin S, effectively degrade leptin.
- Cathepsin S-mediated leptin degradation inactivates its angiogenic and appetite-regulating functions.
- Cysteine cathepsins are suggested as potential regulators of leptin activity within WAT.
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