RNA production of IgG receptors is present in podocytes and varies depending on glycemia – preliminary results on Fc gamma receptor presence in kidney cells

Abstract

Diabetes results from high blood glucose level and is one of the four main noncommunicable diseases. It is also a major cause of kidney failure. An inflammation of renal tissue during diabetic kidney disease (DKD) is aimed to resolve the ongoing homeostatic imbalance, however it leads to renal tissue injury. Because, the kidney glomerulus, where the blood filtration occurs, is an immunologically privileged place with very few leukocytes within, it was suspected that cells within the glomerulus possess immunological features and may initiate or increase the inflammation of renal tissue. One of the cell types in glomerulus, podocytes, are not only crucial for plasma filtration, but also can phagocytose and were described as professional antigen presenting cells. Due to an increased level of IgG-based immune complexes generated in the blood of diabetic patients and deposited in their kidneys, it was also proposed, that podocytes may express receptors for Fc fragment of IgG (FcγRs), which initiate phagocytosis. Many analyses point to that, but it has never been tested before. Thus, in the current study, we have analyzed mRNA expression levels of FcγR-coding genes in human podocytes, compared it to their expression levels in other non-immune epithelial cells (ovarian cells) and to leukocytes, as well as compared FcγR-coding genes’ expression levels in podocytes cultured in a medium with standard versus high glucose concentration. The detection of FcγR expression in podocytes could help to understand the pathomechanism of renal tissue inflammation during DKD and subsequently help to prevent or minimize it.