Reduced adipose tissue H₂S in obesity

Area of Science:

• Biochemistry and Metabolism
• Endocrinology
• Molecular Biology

Background:

• Hydrogen sulfide (H2S) is an endogenous signaling molecule crucial for bioenergetics and metabolism.
• H2S is synthesized by three key enzymes: cystathionine γ-lyase (CSE), cystathionine β-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST).
• Altered H2S levels are implicated in various metabolic disorders.

Purpose of the Study:

• To investigate the expression of H2S-producing enzymes (CSE, CBS, 3-MST) in adipose tissues.
• To examine changes in enzyme expression and H2S levels in mouse models of obesity and metabolic disruption.
• To explore the potential role of reduced H2S in obesity-associated metabolic alterations.

Main Methods:

• Analysis of mRNA and protein levels of CSE, CBS, and 3-MST in epididymal white adipose tissue (EWAT) and brown adipose tissue (BAT).
• Utilized mouse models including high-fat diet (HFD)-induced obesity, db/db genetic obesity model, and age-related weight gain model.
• Measured tissue H2S levels in different adipose depots across the models.

Main Results:

• HFD-fed mice showed reduced mRNA for all three enzymes in EWAT and reduced CSE/3-MST in BAT; 3-MST protein was decreased in all fat depots.
• Db/db mice exhibited reduced mRNA for CSE, CBS, and 3-MST in white fat, and reduced CSE in BAT; CBS and CSE protein levels were suppressed in all fat depots.
• Lower H2S levels were observed in WAT of HFD mice and in both WAT and BAT of db/db mice.

Conclusions:

• Obesity in mice is associated with decreased expression of H2S-synthesizing enzymes and lower H2S levels in adipose tissues.
• The reduction in H2S may contribute to the metabolic dysregulation observed in obesity.
• Further research is warranted to determine if restoring H2S levels can ameliorate obesity-associated metabolic changes.