| 1. |
- Carvalho, Eugénia, 1967, et al.
(författare)
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Low cellular IRS 1 gene and protein expression predict insulin resistance and NIDDM.
- 1999
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Ingår i: The FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 0892-6638 .- 1530-6860. ; 13:15, s. 2173-8
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Tidskriftsartikel (refereegranskat)abstract
- We examined the gene and protein expression of IRS 1 (insulin receptor substrate 1) in adipocytes from two groups of healthy individuals with an increased propensity for non-insulin-dependent diabetes mellitus (NIDDM): those with two first-degree relatives with diabetes and another group with massive obesity. A low expression of IRS 1 (
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| 2. |
- Gustafson, Birgit, 1951, et al.
(författare)
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BMP4 and BMP antagonists regulate human white and beige adipogenesis.
- 2015
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Ingår i: Diabetes. - : American Diabetes Association. - 1939-327X .- 0012-1797. ; 64:5, s. 1670-1681
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Tidskriftsartikel (refereegranskat)abstract
- The limited expandability of subcutaneous adipose tissue, due to reduced ability to recruit and differentiate new adipocytes, prevents its buffering effect in obesity and is characterized by expanded adipocytes (hypertrophic obesity). Bone morphogenetic protein-4 (BMP4) plays a key role in regulating adipogenic precursor cell commitment and differentiation. We found BMP4 to be induced and secreted by differentiated (pre)adipocytes and BMP4 protein was increased in large adipose cells. However, the precursor cells exhibited a resistance to BMP4 due to increased secretion of the BMP inhibitor Gremlin-1 (GREM1). GREM1 is secreted by (pre)adipocytes and is an inhibitor of both BMP4 and BMP7. BMP4 alone, and/or silencing GREM1, increased transcriptional activation of peroxisome proliferator-activated receptor-γ (PPARγ) and promoted the preadipocytes to assume an oxidative beige/brown adipose phenotype including markers of increased mitochondria and PGC1α. Driving white adipose differentiation inhibited the beige/brown markers suggesting the presence of multipotent adipogenic precursor cells. However, silencing GREM1 and/or adding BMP4 during white adipogenic differentiation re-activated beige/brown markers suggesting that increased BMP4 preferentially regulates the beige/brown phenotype. Thus BMP4, secreted by white adipose cells, is an integral feedback regulator of both white and beige adipogenic commitment and differentiation and resistance to BMP4 by GREM1 characterizes hypertrophic obesity.
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| 3. |
- Herrera, Marcela, et al.
(författare)
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Inhibition of T-cell activation by CTLA4-Fc is sufficient to ameliorate proteinuric kidney disease.
- 2017
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Ingår i: American journal of physiology. Renal physiology. - : American Physiological Society. - 1522-1466 .- 1931-857X. ; 312:4
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Tidskriftsartikel (refereegranskat)abstract
- Diabetic Nephropathy (DN) remains an unmet medical challenge as its prevalence is projected to continue to increase and specific medicines for treatment remain undeveloped. Activation of the immune system, in particular T-cells, is emerging as a possible mechanism underlying DN disease progression in humans and animal models. We hypothesized that inhibition of T-cell activation will ameliorate DN. Interaction of B7-1 (CD80) on the surface of antigen presenting cells with its binding partners, CTLA4 (CD152) and CD28 on T-cells, is essential for T-cell activation. In this study we used the soluble CTLA4-Fc fusion protein Abatacept to block cell surface B7-1, preventing the cellular interaction and inhibiting T-cell activation. When Abatacept was dosed in an animal model of diabetes-induced albuminuria, it reduced albuminuria in both prevention and intervention modes. The number of T-cells infiltrating the kidneys of DN animals correlated with the degree of albuminuria and treatment with Abatacept reduced the number of renal T-cells. As B7-1 induction has been recently proposed to underlie podocyte damage in DN, Abatacept could be efficacious in DN by protecting podocytes. However, this does not appear to be the case as B7-1 was not expressed in: 1) kidneys of DN animals; 2) stimulated human podocytes in culture; or 3) glomeruli of DN patients. We conclude that Abatacept ameliorates DN by blocking systemic T-cell activation and not by interacting with podocytes.
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