Red blood cell proteomics reveal remnant protein biosynthesis and folding pathways in PIEZO1-related hereditary xerocytosis

Abstract

Hereditary xerocytosis is a dominant red cell membrane disorder characterized by an increased leak of potassium from the inside to outside the red blood cell membrane, associated with loss of water leading to red cell dehydration and chronic hemolysis. 90% of cases are related to heterozygous gain of function mutations in PIEZO1, encoding a mechanotransductor that translates a mechanical stimulus into a biological signaling. Data are still required to understand better PIEZO1-HX pathophysiology. Recent studies identified proteomics as an accurate and high-input tool to study erythroid progenitors and circulating red cell physiology. Here, we isolated red blood cells from 5 controls and 5 HX patients carrying an identified and pathogenic PIEZO1 mutation and performed a comparative deep proteomic analysis. A total of 603 proteins were identified among which 56 were differentially expressed (40 over expressed and 16 under expressed) between controls and HX with a homogenous expression profile within each group. We observed relevant modifications in the protein expression profile related to PIEZO1 mutations, identifying two main “knots”. The first contained both proteins of the chaperonin containing TCP1 complex involved in the assembly of unfolded proteins, and proteins involved in translation. The second contained proteins involved in ubiquitination. Deregulation of proteins involved in protein biosynthesis was also observed in in vitro-produced reticulocytes after Yoda1 exposure. Thus, our work identifies significant changes in the protein content of PIEZO1-HX erythrocytes, revealing a “PIEZO1 signature” and identifying potentially targetable pathways in this disease characterized by a heterogeneous clinical expression and contra-indication of splenectomy.

Exploring unconventional attributes of red blood cells and their potential applications in biomedicine

“…The discovery of midnolin, a protein that shuttles non-ubiquitinated nuclear proteins to the proteasome ( Gu et al, 2023 ), may shed some light on this pathway, but it remains to be determined if RBCs contain a midnolin-like protein. Notably, translation- and protein control-related molecules seem to differ in RBCs from different pathophysiological backgrounds, such as with glucose-6-phosphate dehydrogenase deficiency ( Tzounakas et al, 2022b ), beta-thalassemia trait ( Anastasiadi et al, 2021b ), and hereditary xerocytosis ( Caulier et al, 2022 ), adding complexity to these “simple” cells.…”

Modeling Red Blood Cell Metabolism in the Omics Era

“…To this end, RBCs have evolved to maximize oxygencarrying capacity by removing non-essential cellular components for this task-nuclei and organelles [3]. Of note, the almost complete inability [4] to de novo synthesize proteins in response to environmental stimuli has contributed to the evolutive pressure that favorably selected mechanisms of metabolic regulation of RBC physiology, including modulation of hemoglobin allostery to facilitate oxygen binding at high oxygen saturation in the lung and oxygen release under hypoxic districts, where oxygen demand is high [5]. Therefore, understanding RBC metabolism and its regulation is essential to understanding physiological regulation by oxygen and thus, virtually, almost every aspect of health and disease.…”