Disease relevance of LGR5

• Overexpression of orphan G-protein-coupled receptor, Gpr49, in human hepatocellular carcinomas with beta-catenin mutations [1].

High impact information on LGR5

• The physiological role of an orphan G protein-coupled receptor, LGR5, was investigated by targeted deletion of this seven-transmembrane protein containing a large N-terminal extracellular domain with leucine-rich repeats [2].
• The observed ankyloglossia phenotype provides a model for understanding the genetic basis of this craniofacial defect in humans and an opportunity to elucidate the physiological role of the LGR5 signaling system during embryonic development [2].
• Gross and histological examination revealed fusion of the tongue to the floor of oral cavity in the mutant newborns and immunostaining of LGR5 expression in the epithelium of the tongue and in the mandible of the wild-type embryos [2].
• LGR5 null mice exhibited 100% neonatal lethality characterized by gastrointestinal tract dilation with air and an absence of milk in the stomach [2].
• Moreover, introduction of mutant beta-catenin into mouse hepatocytes in culture caused up-regulation of the Gpr49 mouse homologue [1].

Biological context of LGR5

• Comparison of overall amino acid sequences indicated that LGR4 and LGR5 are closely related to each other but diverge, during evolution, from the homologous receptor found in snail and the mammalian glycoprotein hormone receptors [3].
• In addition, expression of GPR49 induced transformation in a ligand-dependent manner and Knockdown of GPR49 mRNA level induced apoptosis in colon tumor cells [4].
• Radiation hybrid mapping placed HG38 into human chromosome 12q22-23 [5].
• Thus, the aim of this study was to evaluate single-dose and steady-state bioequivalence of FEX 180 mg/PSE 240 mg 24-h compared with the individual formulations taken concurrently [6].
• CONCLUSIONS: These findings demonstrate that the pharmacokinetics of the new 24-h FEX 180 mg/PSE 240 mg combination formulation are bioequivalent to the concurrent administration of the individual drug components [6].

Anatomical context of LGR5

• In contrast to the restricted tissue expression of gonadotropin and TSH receptors in gonads and thyroid, respectively, LGR4 is expressed in diverse tissues including ovary, testis, adrenal, placenta, thymus, spinal cord, and thyroid, whereas LGR5 is found in muscle, placenta, spinal cord, and brain [3].
• Northern blot analysis showed that HG38 was expressed in skeletal muscle, placenta, spinal cord, and various regions of the brain [5].

Associations of LGR5 with chemical compounds

• OBJECTIVE: A 24-h extended-release formulation of fexofenadine HCl 180 mg/pseudoephedrine HCl 240 mg (FEX 180 mg/PSE 240 mg) has recently been approved by the US Food and Drug Administration for symptom relief of seasonal allergic rhinitis, including nasal congestion [6].
• Seventh to tenth generation NPFs were cultured with or without 1 microg/ml lipopolysaccharide (LPS) in the presence of various concentrations of FEX [7].

Analytical, diagnostic and therapeutic context of LGR5

• In addition to colon tumors, GPR49 was also found to be upregulated in 18 of 33 (53%) ovarian primary tumor tissues analyzed by RT-PCR [4].
• Plasma concentrations of FEX and PSE were determined using high-performance liquid chromatography/mass spectrometry [6].

References