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Rachid, L.

Publications and source records attributed to Rachid, L..

2 recordsLinked to original sources

Inhibition of the NLRP3 Inflammasome Prevents Hyperglycemia in a Humanized Rodent Model of Type 2 Diabetes

The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome is a protein complex that senses metabolic disturbances and in response processes IL-1beta. Prolonged activation of the NLRP3 inflammasome by metabolic stress induces chronic low-grade inflammation and contributes to the development type 2 diabetes and its comorbidities. Here, we developed a mouse model of type 2 diabetes that features impaired proinsulin processing and the ability to form islet amyloid plaques, two determinants of human type 2 diabetes pathology. We show that at advanced ages, these mice develop amyloidosis and inflammation in their insulin-producing pancreatic islets. Beta-cell mass and function were impaired in these mice and severe hyperglycemia developed within 6 months. Oral application of OLT1177, a selective inhibitor of the NLRP3 inflammasome, prevented the development of hyperglycemia. Our data show that inhibition of the NLRP3 inflammasome in a humanized mouse model of severe type 2 diabetes prevents the development of amyloid-associated hyperglycemia.

Cell Biology↗

Cystine/glutamate antiporter system Xc- deficiency impairs insulin secretion.

System Xc-, encoded by Slc7a11, is an antiporter that exports glutamate and imports cystine. Cystine is used for protein synthesis and incorporation in thiol peptides such as glutathione, which function as cofactors for reactive oxygen species scavenging enzymes. Glutamate export by astrocytes through system Xc- has been implicated in excitotoxicity, a form of neurotoxicity that has been postulated to also occur in insulin-producing beta-cells in the pancreatic islets. This study describes the implications of Slc7a11 deficiency on glucose metabolism in both constitutive and myeloid cells-specific knockout mice. Constitutive Slc7a11 deficiency leads to drastically lowered glutathione levels in the pancreatic islets and immune cells in addition to diminished insulin secretion both in vitro and in vivo. Macrophage-specific deletion did not have a significant impact on metabolism or islet function. These findings suggest that system Xc- is required for glutathione maintenance and insulin production in beta-cells, but is dispensable for islet macrophage function.

molecular biology↗