Distinct global DNA methylation and NF-κB expression profile of preimplantation biopsies from ideal and non-ideal kidneys
Naiane do Nascimento Gonçalves1,4, Heloisa Cristina Caldas1,4, Greiciane Maria da Silva Florim1, Giovanna Mattiello Sormani1, Lidia Maria Rebolho Batista Arantes2, Bruna Pereira Sorroche2, Maria Alice Sperto Ferreira Baptista1,4, Ida Maria Maximina Fernandes-Charpiot1,4, Carlos Henrique Viese Nascimento-Filho3, Rogério Moraes de Castilho3, Mario Abbud-Filho1,4.
1Medicine , Laboratory of Immunology and Experimental Transplantation (LITEX), Medical School of Sao Jose do Rio, Sao Jose Do Rio Preto, Brazil; 2Medicine , Molecular Oncology Research Center, Barretos Cancer Hospital, Barretos, Brazil; 3Periodontics and Oral Medicine, Laboratory of Epithelial Biology, University of Michigan School of Dentistry, Ann Arbor, MI, United States; 4Kidney Transplant Unit, Hospital de Base, FAMERP/FUNFARME, Sao Jose Do Rio Preto, Brazil
Background: Epigenetic mechanisms may differently affect the ideal and non-ideal kidneys and their inflammatory gene expression profile and may contribute to poor clinical outcomes.
Objective: To identify the Global DNA methylation was evaluated, as well as the expression profiles of the DNA methyltransferases (DNMTs) and nuclear factor kappa B (NF-κB) in preimplantation kidney biopsies from ideal and non-ideal kidneys (extended criteria donor-ECD and with KDPI>85%).
Methods: Global DNA methylation was estimated by LINE-1 repeated elements methylation using bisulfite pyrosequencing, DNMTs expression was assessed by q-PCR and NF-κB protein expression by immunofluorescence.
Results: ECD kidneys displayed increased methylation levels in LINE-1, and DNMT1 and DNMT3B expression were upregulated when comparing ECD to standard criteria donor kidneys. Similarly, kidneys with KDPI > 85% exhibited increased LINE-1 hypermethylation and DNMT1 upregulation vs. kidneys with a KDPI ≤ 85%. NF-κB protein expression levels were greatly increased in both types of non-ideal kidneys compared to ideal kidneys. Moreover, hypermethylation of LINE-1 was associated with cold ischemia time > 20 h and ECD kidney classification.
Conclusions: This study shows that global DNA hypermethylation and high expression of NF-κB occurred in both types of non-ideal kidneys and were associated with prolonged cold ischemia time. Global DNA methylation can be a useful tool to assess suboptimal kidneys and hence, could be used to increase the use of these kidneys to expand the donor pool.
This study was supported by São Paulo State Research Foundation (FAPESP – Fundação de Amparo à Pesquisa do Estado de São Paulo) grant number 2016/08301-8.
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