Changes in expression of signal transduction-related genes, and formation of aggregates of GPER1 and OXTR receptors in mucopolysaccharidosis cells

Abstract

Mucopolysaccharidoses (MPS) are inherited metabolic diseases caused by storage of glycosaminoglycans (GAGs), however, various modulations of the course of these diseases were identified recently due to impairment of different cellular processes. Here, using transcriptomic analyses in cells derived from patients suffering from eleven types of MPS, we demonstrated that expression of dozens to hundreds of genes coding for proteins involved in signal transduction processes is significantly changed in MPS cell relative to controls. When studying membrane estrogen receptor 1 (GPER1) and oxytocin receptor (OXTR) in more detail, we unexpectedly found formation of aggregates of GPER1 in MPS I, and those of OXTR in both MPS I and MPS II cells. The presence of these aggregates did not correlate with levels of expression of GPER1 and OXTR genes and levels of corresponding gene products. On the other hand, the aggregates disappeared in cells treated with enzymes which are otherwise deficient in MPS I and MPS II, causing efficient degradation of GAGs. We demonstrated that GPER1 and OXTR aggregates might be formed due to interactions with GAGs rather than arising from changes of levels of these proteins in cells.