Role of histones deacetylases in regeneration and macrophage polarization in post-inducing acute kidney injury in Zebrafish (Danio rerio)

• Grant number: 20/10263-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2021
• End date: July 31, 2025
• Field of knowledge: Biological Sciences - Immunology - Cellular Immunology
• Principal Investigator: Niels Olsen Saraiva Câmara
• Grantee: Lais Cavalieri Paredes
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/05264-7 - Cell metabolism, microbiota and immune system: new paradigms in renal diseases physiopathology, AP.TEM
• Associated scholarship(s): 23/04482-1 - B2m role in the crosstalk between macrophages and HSPCs and its impact on hematopoietic clonality, BE.EP.DR

Abstract

Acute Kidney Injury (AKI) is defined as an abrupt decrease in renal function, compromising the structure and function of the kidneys, and which, in developed countries, affects about 15% of hospitalized patients. After the injury, macrophages and neutrophils are recruited and participate in several processes, including the promotion and subsequent resolution of inflammation. The epigenetic control of some transcription factors, characterized by changes in the chromatin arrangement through acetylation, among other processes, has been shown to be the main regulatory mechanism for the transcription of genes related to tissue regeneration. Thus, the hypothesis is that histone deacetylases act in the transition of phenotypes from pro-inflammatory macrophages to pro-resolving macrophages, playing an important role in the modulation of processes that promote renal regeneration in Zebrafish. To this end, the present study aims to investigate the role of these enzymes in the renal regenerative process in Zebrafish and to identify metabolic changes in infiltrating macrophages, at different times after injury. AKI will be induced with the use of cisplatin, a highly nephrotoxic drug. The Zebrafish larvae will be treated prophylactically or therapeutically with valproic acid, and then sent for survival analysis, expression of genes related to cell de-differentiation and renal damage, in addition to parameters such as cell death and proliferation, and the polarization of macrophages by fluorescence microscopy and flow cytometry. In addition, we will develop knockout animals (KO) for arg1, a positively regulated gene in M2 macrophages. The KO animals will be used for the investigation of macrophage polarization. For this, after the construction of the genetically modified fish, we will isolate macrophages, in different stages of the lesion, and study the remodeling of chromatin. Finally, to look for the mechanisms, we hope to specifically study the acetylation of histones in genes involved in the polarization of macrophages in vitro, under the action of valproic acid or trichostatin A, through the adoptive transfer of these cells to animals depleted of macrophages. We hope, with this project, to unravel the role of histone deacetylases enzymes in renal regeneration and their relationship with the performance of cells of the innate immune system. (AU)