Rescue of Cell Surface Expression and Signaling of Mutant Follicle-Stimulating Hormone Receptors

Mutations in G protein-coupled receptors (GPCRs) underlie numerous diseases. Many cause receptor misfolding and failure to reach the cell surface. Pharmacological chaperones are cell-permeant small molecules that engage nascent mutant GPCRs in the endoplasmic reticulum, stabilizing folding and "rescuing" cell surface expression. We previously demonstrated rescue of cell surface expression of luteinizing hormone receptor mutants by an allosteric agonist. Here we demonstrate that a similar approach can be employed to rescue mutant follicle-stimulating hormone receptors (FSHRs) with poor cell surface expression using a small-molecule FSHR agonist, CAN1404. Seventeen FSHR mutations described in patients with reproductive dysfunction were expressed in HEK 293T cells, and cell surface expression was determined by enzyme-linked immunosorbent assay of epitope-tagged FSHRs before/after treatment with CAN1404. Cell surface expression was severely reduced to ≤18% of wild-type (WT) for 11, modestly reduced to 66% to 84% of WT for 4, and not reduced for 2. Of the 11 with severely reduced cell surface expression, restoration to ≥57% of WT levels was achieved for 6 by treatment with 1 µM CAN1404 for 24 h, and a corresponding increase in FSH-induced signaling was observed for 4 of these, indicating restored functionality. Therefore, CAN1404 acts as a pharmacological chaperone and can rescue cell surface expression and function of certain mutant FSHRs with severely reduced cell surface expression. These findings aid in advancing the understanding of the effects of genetic mutations on GPCR function and provide a proof of therapeutic principle for FSHR pharmacological chaperones.

Profile of follicle-stimulating hormone and polymorphism of follicle-stimulating hormone receptor in Madrasin cattle with ovarian hypofunction

Background and Aim

The follicle-stimulating hormone (FSH) gene is an essential regulator of fertility in livestock. This study aims to provide information on the genetic makeup of Madrasin cattle experiencing hypofunction by the FSH profile and FSH receptors (FSHR) polymorphism.

Materials and Methods

Blood samples were collected from the Bangkalan regency in Indonesia. DNA was isolated and purified following the extraction protocol of polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism.

Results

Our results showed that the FSH gene had a band length of 310 bp and produce two alleles (A and B) with restriction enzymes at 250 bp, 230 bp, and 145 bp. Furthermore, the FSHR gene had a band length of 303 bp and produced two homozygous genotypes: GG at bp 239 and CC at bp 188.

Conclusion

Based on these differences, there was no change in allele frequency and genotype between Madura and Madrasin cattle due to crossbreeding with Limousin cattle. Thus, further detailed investigations of Madrasin cattle are required to elucidate the profile of the LH and LHR genes.