Biochemi

Seminar

-Relationship between vitamin D and obesity

-Obesity…complications, psychological, financial

-Functions of Adipose tissue

-regulation of insulin, blood pressure

-changes in adipose tissue during obesity- obese with metabolic dysfunction( increase inflammation)

-Vitamin D metabolism

-Vitamin D status is inversely correlated with markers of adiposity

-Vitamin D regulates adipose tissue function

-Adipocyte differentiation- pre-adipocyte- early adipocyte - mature adipocyte

-glucocorticoid and insulin promote adipocyte differentiation.

Does 1,25(OH)2D Inhibits 3t3-l1 differentiation in a dose-dependent manner

-Lipid storage in adipocytes(image)

-1,25(OH)2D stimulates lipolysis in 3T3-L1 Adipocytes

-TAG storage in adipocytes

-effect of 1,25(OH)2D on lipolytic protein expression.

Conclusion:

1,25(OH)2D stimulates:

-increased PKA-dependent lipolysis

-increased HSL phosphorylation

-increased CGI-58 protein expression

-decreased ATGL protein expression

Extracellular fatty acid accumulation does not account for reduction in TAG stores.

1,25(OH)2D stimulates fatty acid uptake in 3T3-L1 Adipocytes

1,25(OH)2D reduces acetate incorporation into fatty acids

1,25(OH)2D stimulates:

-decreased glucose incorporation into fatty acids

-decreased ACC1/FAS activity

Effect of 1,25(OH)2D on 3T3-L1 Adipocytes:

Increased fatty acid turnover

-decreased glucose incorporation into fatty acids

Implications:

-Reduced TAG accumulation may alleviate chronic inflammation associated with expansion of adipose tissue.

- Inhibition of de novo lipogenesis in adipose tissue, coupled with increased insulin sensitivity in skeletal muscle, may be metabolically favorable.

Future Studies:

-Identify the lowest concentration of 1,25(OH)2D that is sufficient to induce these changes in 3T3-L1 adipocytes.

- Determine whether 1,25(OH)2D- induced regulation of lipid metabolism specific to murine adipocytes.

-Identify vitamin D target genes responsible for...