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Juliane Glaubitz

Publications and source records attributed to Juliane Glaubitz.

2 recordsLinked to original sources

Interleukin-1α Mediates Pancreatic Fibroblast Activation, Regulates Immune Cell Recruitment and Fibrosis in Acute and Chronic Pancreatitis.

Pancreatitis is a life-threatening inflammatory disease of the pancreas. The cytokine interleukin-1α has been demonstrated to act as an alarmin released by necrotic cells. In the present study, we investigated the influence of IL-1α on the immune response during acute and chronic pancreatitis. Following tissue injury, pancreatic acinar cells released IL-1α, which activates tissue-resident fibroblasts to differentiate toward a pro-inflammatory phenotype. By secreting chemokines and cytokines such as CXCL5, CCL2, and IL-6, these fibroblasts recruit immune cells to the pancreas. The absence of IL-1α reduces disease severity in acute pancreatitis and chemokine release. Furthermore, IL-1α primes fibroblasts to enhance the production of extracellular matrix-components by the up-regulation of pro-fibrotic receptors such as Il4ra, Il13ra1, and Tgfbr3. Therefore, the deletion of IL-1α significantly reduced the development of tissue fibrosis. A therapeutic blockade of the IL1R1-signaling by i.p. administration of the IL-1-receptor antagonist Anakinra showed the same effect; the severity of acute pancreatitis and fibrogenesis during chronic pancreatitis were reduced. In conclusion, the crosstalk between necrotic acinar cells and fibroblasts mediated by IL-1α plays a crucial role in acute inflammation of the pancreas and fibrogenic signaling. Blockade of IL1R1-signaling by Anakinra is therefore a promising therapeutic intervention for both acute and chronic pancreatitis.

Anakinra

Identifying transcription factors controlling the basal expression of human MRP4 highlights a substantial role for Sp1.

The multidrug resistance protein 4 (MRP4/ABCC4) is a versatile efflux pump, known to transport several drugs but also signaling molecules such as cyclic nucleotides and lipid mediators. Based on this substrate spectrum and its broad tissue distribution, MRP4 plays a significant physiological and pathophysiological role in both the cardiovascular and oncological fields. However, the determinants of its gene expression are still incompletely defined. This study aimed to identify key regulatory elements and transcription factors that are essential for basal MRP4 expression. Using luciferase reporter assays with a series of 5'-deletion constructs, we identified a region upstream of the transcription start site as crucial for basal expression across diverse cell types. This region is evolutionary highly conserved and contains putative binding sites for Sp1 and Ets transcription factors. Site-directed mutagenesis of both binding elements resulted in a significant decrease in the promoter activity in HeLa and megakaryoblastic M07e cells. The binding of Sp1 to this region was further confirmed by electrophoretic mobility shift and chromatin immunoprecipitation assays. Finally, siRNA knockdown of Sp1 led to a significant decrease in MRP4 protein levels and function. In summary, we show that Sp1 binds to the MRP4 promoter and plays an essential role in the basal expression of MRP4, with Ets factors also potentially cooperating in this regulation.

Humans