Evaluation of in vivo bioactivities of recombinant hypo- (FSH 21/18 ) and fully- (FSH 24 ) glycosylated human FSH glycoforms in Fshb null mice

Autor: Jacob May, Jeffrey V. May, Huizhen Wang, T. Rajendra Kumar, Bin Shuai, Viktor Y. Butnev, George R. Bousfield
Rok vydání: 2016
Předmět:
Male
0301 basic medicine
endocrine system
Glycosylation
Time Factors
Protein subunit
Blotting
Western
030209 endocrinology & metabolism
Ovary
Biology
Real-Time Polymerase Chain Reaction
Biochemistry
Article
FSHB
law.invention
03 medical and health sciences
0302 clinical medicine
Endocrinology
Western blot
In vivo
law
medicine
Animals
Humans
Phosphorylation
Ovarian follicle
Cyclic AMP Response Element-Binding Protein
Molecular Biology
Mice
Knockout
medicine.diagnostic_test
Molecular biology
Recombinant Proteins
In vitro
carbohydrates (lipids)
030104 developmental biology
medicine.anatomical_structure
Gene Expression Regulation
Follicle Stimulating Hormone
beta Subunit
Recombinant DNA
Female
Follicle Stimulating Hormone
Human
hormones
hormone substitutes
and hormone antagonists
Signal Transduction
Zdroj: Molecular and Cellular Endocrinology. 437:224-236
ISSN: 0303-7207
Popis: The hormone - specific FSHβ subunit of the human FSH heterodimer consists of N-linked glycans at Asn7 and Asn24 residues that are co-translationally attached early during subunit biosynthesis. Differences in the number of N-glycans (none, one or two) on the human FSHβ subunit contribute to macroheterogeneity in the FSH heterodimer. The resulting FSH glycoforms are termed hypo-glycosylated (FSH21/18, missing either an Asn24 or Asn7 N-glycan chain on the β - subunit, respectively) or fully glycosylated (FSH24, possessing of both Asn7 and Asn24 N-linked glycans on the β - subunit) FSH. The recombinant versions of human FSH glycoforms (FSH21/18 and FSH24) have been purified and biochemically characterized. In vitro functional studies have indicated that FSH21/18 exhibits faster FSH- receptor binding kinetics and is much more active than FSH24 in every assay tested to date. However, the in vivo bioactivity of the hypo-glycosylated FSH glycoform has never been tested. Here, we evaluated the in vivo bioactivities of FSH glycoforms in Fshb null mice using a pharmacological rescue approach. In Fshb null female mice, both hypo- and fully-glycosylated FSH elicited an ovarian weight gain response by 48 h and induced ovarian genes in a dose- and time-dependent manner. Quantification by real time qPCR assays indicated that hypo-glycosylated FSH21/18 was bioactive in vivo and induced FSH-responsive ovarian genes similar to fully-glycosylated FSH24. Western blot analyses followed by densitometry of key signaling components downstream of the FSH-receptor confirmed that the hypo-glycosylated FSH21/18 elicited a response similar to that by fully-glycosylated FSH24 in ovaries of Fshb null mice. When injected into Fshb null males, hypo-glycosylated FSH21/18 was more active than the fully-glycosylated FSH24 in inducing FSH-responsive genes and Sertoli cell proliferation. Thus, our data establish that recombinant hypo-glycosylated human FSH21/18 glycoform elicits bioactivity in vivo similar to the fully-glycosylated FSH. Our studies may have clinical implications particularly in formulating FSH-based ovarian follicle induction protocols using a combination of different human FSH glycoforms.
Databáze: OpenAIRE
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