Generation and characterisation of seven induced pluripotent stem cell lines from two patients with Parkinson's disease carrying the pathological variant c.1087G>T of the LGR4 gene.

Parkinson's disease is a neurodegenerative disorder affecting dopaminergic neurons of the substantia nigra pars compacta. The known pathological genetic variants may explain the cause of only 5 % of cases of the disease. In our study, we found two patients with a clinical diagnosis of Parkinson's disease with the genetic variant c.1087G>T (p.Gly363Cys) of the LGR4 gene. The LGR4 gene encodes the membrane receptor LGR4 (leucine rich repeat containing G protein-coupled receptor 4) associated with the G protein. We hypothesize that the LGR4 gene may be either a direct cause or a risk factor for this disease, since it is one of the main participants of the WNT/β-catenin signalling pathway. This signalling pathway is necessary for the proliferation of neurons during their differentiation, which may lead to Parkinson's disease. To study the relationship between this genetic variant and Parkinson's disease, an ideal tool is a cellular model based on induced pluripotent stem cells (iPSCs) and their differentiated derivatives, dopaminergic neurons. We reprogrammed the peripheral blood mononuclear cells of the two patients with the c.1087G>T variant of the LGR4 gene with non-integrating episomal vectors expressing OCT4, SOX2, KLF4, LIN28, L-MYC and mp53DD proteins. The obtained seven lines of induced pluripotent stem cells were characterised in detail. The iPSCs lines obtained meet all the requirements of pluripotent cells, namely, they stably proliferate, form colonies with a morphology characteristic of human pluripotent cells, have a normal diploid karyotype, express endogenous alkaline phosphatase and pluripotency markers (OCT4, NANOG, SSEA-4 and SOX2) and are capable to differentiate into derivatives of the three germ layers. The iPSC lines obtained in this work can be used as a tool to generate a relevant model to study the effect of the pathological variant c.1087G>T of the LGR4 gene on dopaminergic neuron differentiation.