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 genePodvysotskaya, Grigor'eva, Malakhova
et alVavilovskii Zhurnal Genet Selektsii (2025) 29 (1), 15-25
Abstract: 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.Copyright © AUTHORS.
Deficiency of neuronal LGR4 increases energy expenditure and inhibits food intake via hypothalamic leptin signalingZhang, Li, Gao
et alEMBO Rep (2025)
Abstract: The metabolic effects of leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) remain largely unknown. Here, we showed that knockdown of Lgr4 in nestin progenitor or Sp1 mature neurons reduced high fat diet (HFD)-induced obesity by increasing energy expenditure and inhibiting food intake. Deficiency of LGR4 in AgRP neurons increased energy expenditure, and inhibited food intake, leading to alterations in glucose and lipid metabolism. Knock-down of Lgr4 in Sf1 neurons enhanced energy expenditure, reduced adiposity, and improved glucose and lipid metabolism. The metabolic benefits of neuronal LGR4 occurred via improvement of leptin signaling in AgRP and Sf1 neurons. Knockdown of Lgr4 in nestin, Sp1, AgRP or Sf1 neurons decreased hypothalamic levels of SOCS-3, and increased phosphorylation of STAT3. These alterations were associated with a significant reduction in the hypothalamic levels of β-catenin. Inhibition of β-catenin signaling by Dkk1 significantly attenuated the decrement of phospho-STAT3 and concurrent increase of SOCS-3 induced by Rspondin 3, an endogenous ligand for LGR4. Our results thus demonstrate that hypothalamic LGR4 may promote energy conversation by increasing food intake and decreasing energy expenditure. Deficiency of neuronal LGR4 improves hypothalamic leptin sensitivity via suppression of β-catenin signaling.© 2025. The Author(s).
Receptor deorphanization in starfish reveals the evolution of relaxin signaling as a regulator of reproductionFeng, Escudero Castelán, Hossain
et alBMC Biol (2025) 23 (1), 59
Abstract: Relaxins are a family of peptides that regulate reproductive physiology in vertebrates. Evidence that this is an evolutionarily ancient role of relaxins has been provided by the discovery of two relaxin-like gonad-stimulating peptides (RGP1 and RGP2) that trigger spawning in starfish. The main aim of this study was to identify the receptor(s) that mediate(s) the effects of RGP1 and RGP2 in starfish.Here we show that RGP1 and RGP2 belong to a family of peptides that include vertebrate relaxins, Drosophila insulin-like peptide 8 (Dilp8), and other relaxin-like peptides in several protostome taxa. An ortholog of the human relaxin receptors RXFP1 and RXFP2 and the Drosophila receptor LGR3 was identified in starfish (RXFP/LGR3). In Drosophila, but not in humans and other vertebrates, there is a paralog of LGR3 known as LGR4, and here an LGR4-type receptor was also identified in starfish. In vitro pharmacological experiments revealed that both RGP1 and RGP2 act as ligands for RXFP/LGR3 in the starfish Acanthaster cf. solaris and Asterias rubens, but neither peptide acts as a ligand for LGR4 in these species.Discovery of the RXFP/LGR3-type receptor for RGP1 and RGP2 in starfish provides a new insight into the evolution of relaxin-type signaling as a regulator of reproductive processes. Furthermore, our findings indicate that RXFP/LGR3-type receptors have been lost in several phyla, including urochordates, mollusks, bryozoans, platyhelminthes, and nematodes.© 2025. The Author(s).
Genetic-epigenetic interactions (meQTLs) in orofacial clefts etiologyMachado-Paula, Romanowska, Lie
et almedRxiv (2025)
Abstract: Nonsyndromic orofacial clefts (OFCs) etiology involves multiple genetic and environmental factors with over 60 identified risk loci; however, they account for only a minority of the estimated risk. Epigenetic factors such as differential DNA methylation (DNAm) are also associated with OFCs risk and can alter risk for different cleft types and modify OFCs penetrance. DNAm is a covalent addition of a methyl (CH3) group to the nucleotide cytosine that can lead to changes in expression of the targeted gene. DNAm can be affected by environmental influences and genetic variation via methylation quantitative loci (meQTLs). We hypothesize that aberrant DNAm and the resulting alterations in gene expression play a key role in the etiology of OFCs, and that certain common genetic variants that affect OFCs risk do so by influencing DNAm.We used genotype from 10 cleft-associated SNPs and genome-wide DNA methylation data (Illumina 450K array) for 409 cases with OFCs and 456 controls and identified 23 cleft-associated meQTLs. We then used an independent cohort of 362 cleft-discordant sib pairs for replication. We used methylation-specific qPCR to measure methylation levels of each CpG site and combined genotypic and methylation data for an interaction analysis of each SNP-CpG pair using the R package MatrixeQTL in a linear model. We also performed a Paired T-test to analyze differences in DNA methylation between each member of the sibling pairs.We replicated 9 meQTLs, showing interactions between rs13041247 (MAFB) - cg18347630 (PLCG1) (P=0.04); rs227731 (NOG) - cg08592707 (PPM1E) (P=0.01); rs227731 (NOG) - cg10303698 (CUEDC1) (P=0.001); rs3758249 (FOXE1) - cg20308679 (FRZB) (P=0.04); rs8001641 (SPRY2) - cg19191560 (LGR4) (P=0.04); rs987525(8q24) - cg16561172(MYC) (P=0.00000963); rs7590268(THADA) - cg06873343 (TTYH3) (P=0.04); rs7078160 (VAX1) - cg09487139 (P=0.05); rs560426 (ABCA4/ARHGAP29) - cg25196715 (ABCA4/ARHGAP29) (P=0,03). Paired T-test showed significant differences for cg06873343 (TTYH3) (P=0.04); cg17103269 (LPIN3) (P=0.002), and cg19191560 (LGR4) (P=0.05).Our results confirm previous evidence that some of the common non-coding variants detected through GWAS studies can influence the risk of OFCs via epigenetic mechanisms, such as DNAm, which can ultimately affect and regulate gene expression. Given the large prevalence of non-coding SNPs in most OFCs genome wide association studies, our findings can potentially address major knowledge gaps, like missing heritability, reduced penetrance, and variable expressivity associated with OFCs phenotypes.