Limits...
FGFR1 and PROKR2 rare variants found in patients with combined pituitary hormone deficiencies.

Correa FA, Trarbach EB, Tusset C, Latronico AC, Montenegro LR, Carvalho LR, Franca MM, Otto AP, Costalonga EF, Brito VN, Abreu AP, Nishi MY, Jorge AA, Arnhold IJ, Sidis Y, Pitteloud N, Mendonca BB - Endocr Connect (2015)

Bottom Line: Regarding PROKR2 variants, results from previous functional studies indicated that p.Arg85Cys moderately compromises receptor signalling through both MAPK and Ca(2) (+) pathways while p.Arg248Glu decreases calcium mobilization but has normal MAPK activity.The presence of loss-of-function variants of FGFR1 and PROKR2 in our patients with CPHD is indicative of an adjuvant and/or modifier effect of these rare variants on the phenotype.Other associated genetic and/or environmental modifiers may play a role in the aetiology of this condition.

View Article: PubMed Central - PubMed

Affiliation: Unidade de Endocrinologia do DesenvolvimentoLaboratório de Hormônios e Genética Molecular LIM42Unidade de Endocrinologia GenéticaLaboratório de Endocrinologia Celular e Molecular LIM25, Hospital das Clínicas, Disciplina de Endocrinologia, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Eneas de Carvalho Aguiar, 255, 05403-000 São Paulo, BrazilCentre Hospitalier Universitaire Vaudois (CHUV)Faculté de Biologie et Médecine de l'Univesité de Lausanne, Lausanne, SwitzerlandDivision of EndocrinologyDiabetes, and Hypertension, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA fernandacorrea@usp.br.

No MeSH data available.


Related in: MedlinePlus

Functional analysis of FGFR1 variants. (A, B and C) Signalling activity of WT and altered FGFR1 receptors in L6 myoblasts. Plotted are means±s.e.m. of three independent experiments. p.Ser107Leu (A) and p.Pro772Ser (B) variants had normal signalling activity, while p.Arg448Trp had reduced maximal signalling activity (**statistically significant (P<0.01)) (C). (D) Western blot analysis of CHO cells transiently transfected with empty vector (EV), FGFR1 WT or p.Arg448Trp constructs. UT, untreated; EH, EndoH treated; PG, PNGase treated. (E and F) Densitometry analysis of total protein and maturation levels of WT and p.Arg448Trp receptors. Plotted are means±s.e.m. of three independent experiments. (G) Cell-surface expression levels of WT and p.Arg448Trp receptors assessed in live transiently transfected COS-7 cells. Plotted are means±s.e.m. of five independent experiments (*statistically significant (P<0.05)).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4401104&req=5

fig1: Functional analysis of FGFR1 variants. (A, B and C) Signalling activity of WT and altered FGFR1 receptors in L6 myoblasts. Plotted are means±s.e.m. of three independent experiments. p.Ser107Leu (A) and p.Pro772Ser (B) variants had normal signalling activity, while p.Arg448Trp had reduced maximal signalling activity (**statistically significant (P<0.01)) (C). (D) Western blot analysis of CHO cells transiently transfected with empty vector (EV), FGFR1 WT or p.Arg448Trp constructs. UT, untreated; EH, EndoH treated; PG, PNGase treated. (E and F) Densitometry analysis of total protein and maturation levels of WT and p.Arg448Trp receptors. Plotted are means±s.e.m. of three independent experiments. (G) Cell-surface expression levels of WT and p.Arg448Trp receptors assessed in live transiently transfected COS-7 cells. Plotted are means±s.e.m. of five independent experiments (*statistically significant (P<0.05)).

Mentions: All the three FGFR1 variants were predicted to be pathogenic by at least one of the three prediction programmes tested (Table 1). Signalling activity of these variants was assessed in vitro using the well-established FGF-responsive osteocalcin reporter system, which acts downstream of the MAPK pathway. Cells expressing the p.Ser107Leu and p.Pro772Ser variants elicited dose–response curves similar to the WT FGFR1c curve (Fig. 1A and B). The p.Arg448Trp variant, on the other hand, demonstrated a small (approximately 15%) but significant reduction in maximal signalling activity (P<0.01; Fig. 1C). To evaluate potential molecular mechanisms underlying the observed reduced signalling activity, we performed protein expression studies. Overall protein expression and maturation levels of p.Arg448Trp were similar to those for the WT, indicative of normal protein synthesis and folding processes (Fig. 1D, E and F). However, cell-surface expression levels of this variant were significantly increased compared with the WT (approximately 20%, P<0.05; Fig. 1G), indicating a defect in the receptor internalization process.


FGFR1 and PROKR2 rare variants found in patients with combined pituitary hormone deficiencies.

Correa FA, Trarbach EB, Tusset C, Latronico AC, Montenegro LR, Carvalho LR, Franca MM, Otto AP, Costalonga EF, Brito VN, Abreu AP, Nishi MY, Jorge AA, Arnhold IJ, Sidis Y, Pitteloud N, Mendonca BB - Endocr Connect (2015)

Functional analysis of FGFR1 variants. (A, B and C) Signalling activity of WT and altered FGFR1 receptors in L6 myoblasts. Plotted are means±s.e.m. of three independent experiments. p.Ser107Leu (A) and p.Pro772Ser (B) variants had normal signalling activity, while p.Arg448Trp had reduced maximal signalling activity (**statistically significant (P<0.01)) (C). (D) Western blot analysis of CHO cells transiently transfected with empty vector (EV), FGFR1 WT or p.Arg448Trp constructs. UT, untreated; EH, EndoH treated; PG, PNGase treated. (E and F) Densitometry analysis of total protein and maturation levels of WT and p.Arg448Trp receptors. Plotted are means±s.e.m. of three independent experiments. (G) Cell-surface expression levels of WT and p.Arg448Trp receptors assessed in live transiently transfected COS-7 cells. Plotted are means±s.e.m. of five independent experiments (*statistically significant (P<0.05)).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401104&req=5

fig1: Functional analysis of FGFR1 variants. (A, B and C) Signalling activity of WT and altered FGFR1 receptors in L6 myoblasts. Plotted are means±s.e.m. of three independent experiments. p.Ser107Leu (A) and p.Pro772Ser (B) variants had normal signalling activity, while p.Arg448Trp had reduced maximal signalling activity (**statistically significant (P<0.01)) (C). (D) Western blot analysis of CHO cells transiently transfected with empty vector (EV), FGFR1 WT or p.Arg448Trp constructs. UT, untreated; EH, EndoH treated; PG, PNGase treated. (E and F) Densitometry analysis of total protein and maturation levels of WT and p.Arg448Trp receptors. Plotted are means±s.e.m. of three independent experiments. (G) Cell-surface expression levels of WT and p.Arg448Trp receptors assessed in live transiently transfected COS-7 cells. Plotted are means±s.e.m. of five independent experiments (*statistically significant (P<0.05)).
Mentions: All the three FGFR1 variants were predicted to be pathogenic by at least one of the three prediction programmes tested (Table 1). Signalling activity of these variants was assessed in vitro using the well-established FGF-responsive osteocalcin reporter system, which acts downstream of the MAPK pathway. Cells expressing the p.Ser107Leu and p.Pro772Ser variants elicited dose–response curves similar to the WT FGFR1c curve (Fig. 1A and B). The p.Arg448Trp variant, on the other hand, demonstrated a small (approximately 15%) but significant reduction in maximal signalling activity (P<0.01; Fig. 1C). To evaluate potential molecular mechanisms underlying the observed reduced signalling activity, we performed protein expression studies. Overall protein expression and maturation levels of p.Arg448Trp were similar to those for the WT, indicative of normal protein synthesis and folding processes (Fig. 1D, E and F). However, cell-surface expression levels of this variant were significantly increased compared with the WT (approximately 20%, P<0.05; Fig. 1G), indicating a defect in the receptor internalization process.

Bottom Line: Regarding PROKR2 variants, results from previous functional studies indicated that p.Arg85Cys moderately compromises receptor signalling through both MAPK and Ca(2) (+) pathways while p.Arg248Glu decreases calcium mobilization but has normal MAPK activity.The presence of loss-of-function variants of FGFR1 and PROKR2 in our patients with CPHD is indicative of an adjuvant and/or modifier effect of these rare variants on the phenotype.Other associated genetic and/or environmental modifiers may play a role in the aetiology of this condition.

View Article: PubMed Central - PubMed

Affiliation: Unidade de Endocrinologia do DesenvolvimentoLaboratório de Hormônios e Genética Molecular LIM42Unidade de Endocrinologia GenéticaLaboratório de Endocrinologia Celular e Molecular LIM25, Hospital das Clínicas, Disciplina de Endocrinologia, Faculdade de Medicina da Universidade de São Paulo, Av. Dr. Eneas de Carvalho Aguiar, 255, 05403-000 São Paulo, BrazilCentre Hospitalier Universitaire Vaudois (CHUV)Faculté de Biologie et Médecine de l'Univesité de Lausanne, Lausanne, SwitzerlandDivision of EndocrinologyDiabetes, and Hypertension, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA fernandacorrea@usp.br.

No MeSH data available.


Related in: MedlinePlus