Use of follicle-stimulating hormone for the treatment of female infertility - current concepts

Long-acting recombinant human follicle-stimulating hormone (SAFA-FSH) enhances spermatogenesis

INTRODUCTION

Administration of follicle-stimulating hormone (FSH) has been recommended to stimulate spermatogenesis in infertile men with hypogonadotropic hypogonadism, whose sperm counts do not respond to human chorionic gonadotropin alone. However, FSH has a short serum half-life requiring frequent administration to maintain its therapeutic efficacy. To improve its pharmacokinetic properties, we developed a unique albumin-binder technology, termed "anti-serum albumin Fab-associated" (SAFA) technology. We tested the feasibility of applying SAFA technology to create long-acting FSH as a therapeutic candidate for patients with hypogonadotropic hypogonadism.

METHODS

SAFA-FSH was produced using a Chinese hamster ovary expression system. To confirm the biological function, the production of cyclic AMP and phosphorylation of ERK and CREB were measured in TM4-FSHR cells. The effect of gonadotropin-releasing hormone agonists on spermatogenesis in a hypogonadal rat model was investigated.

RESULTS

In in vitro experiments, SAFA-FSH treatment increased the production of cyclic AMP and increased the phosphorylation of ERK and CREB in a dose-dependent manner. In animal experiments, sperm production was not restored by human chorionic gonadotropin treatment alone, but was restored after additional recombinant FSH treatment thrice per week or once every 5 days. Sperm production was restored even after additional SAFA-FSH treatment at intervals of once every 5 or 10 days.

DISCUSSION

Long-acting FSH with bioactivity was successfully created using SAFA technology. These data support further development of SAFA-FSH in a clinical setting, potentially representing an important advancement in the treatment of patients with hypogonadotropic hypogonadism.

Actions and Roles of FSH in Germinative Cells

Follicle stimulating hormone (FSH) is produced by the pituitary gland in a coordinated hypothalamic-pituitary-gonadal (HPG) axis event, plays important roles in reproduction and germ cell development during different phases of reproductive development (fetal, neonatal, puberty, and adult life), and is consequently essential for fertility. FSH is a heterodimeric glycoprotein hormone of two dissociable subunits, α and β. The FSH β-subunit (FSHβ) function starts upon coupling to its specific receptor: follicle-stimulating hormone receptor (FSHR). FSHRs are localized mainly on the surface of target cells on the testis and ovary (granulosa and Sertoli cells) and have recently been found in testicular stem cells and extra-gonadal tissue. Several reproduction disorders are associated with absent or low FSH secretion, with mutation of the FSH β-subunit or the FSH receptor, and/or its signaling pathways. However, the influence of FSH on germ cells is still poorly understood; some studies have suggested that this hormone also plays a determinant role in the self-renewal of germinative cells and acts to increase undifferentiated spermatogonia proliferation. In addition, in vitro, together with other factors, it assists the process of differentiation of primordial germ cells (PGCLCs) into gametes (oocyte-like and SSCLCs). In this review, we describe relevant research on the influence of FSH on spermatogenesis and folliculogenesis, mainly in the germ cell of humans and other species. The possible roles of FSH in germ cell generation in vitro are also presented.

Chinese medicine as complementary therapy for female infertility

Chinese medicine (CM) has been used in clinical treatment for thousands of years in China, Japan, Korea, and other countries. CM is at present attracting many attentions around the world for reproductive health care and disease prevention, including treatment of female infertility. This review focuses on the CM treatment for female infertility patients, and supplies a summary on the efficacy, safety, and mechanism of some Chinese herbal medicines, herbal medicine-derived active compounds, and acupuncture. A large number of researches have reported that CM could alleviate or even cure female infertility by regulating hormone, improving reproductive outcome of in vivo fertilization, affecting embryonic implantation, curing polycystic ovarian syndrome, endometriosis, pelvic inflammatory disease, relieving mental stress, and regulating immune system. Meanwhile, a few studies claimed that there was little adverse reaction of CM in randomized controlled trials. However, up to present there is a lack of adequate evidences with molecular mechanistic researches and randomized controlled trials to prove the CM as an effective and safe treatment for infertility. Thus, utility of CM as a complementary medicine will be a feasible method to improve the outcome of female infertility treatment.

Effects of FSH extracted from in vitro cultured anterior pituitary cells of male buffalo calves on body and testes weight, serum FSH and total cholesterol and hematological variables in male rabbits

In this study, anterior pituitary glands were collected from 12 young male buffalo calves after slaughter, cultured with gonadotropin releasing hormone (GnRH) and estrogen stimulus and the extract obtained. Adult male rabbits (n = 15) were divided into three equal groups. Rabbits of Group A served as control; those of Groups B and C were given extract containing 4 and 8 mIU of follicle stimulating hormone (FSH), respectively twice daily for 3 weeks. Body weight of rabbits was recorded before and after treatment; blood samples were collected after treatment and analyzed for hemoglobin (Hb), red blood cell (RBC) count, white blood cell (WBC) count, packed cell volume (PCV), platelet counts, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH), while serum samples were analyzed for FSH and total cholesterol. Then, all rabbits were slaughtered, and weight of paired testes was recorded. Results showed that the values for weight gain, RBC count, WBC count, PCV and MCH did not differ among rabbits of three groups. Blood Hb was greater (P < 0.05) in rabbits of Group B than Group C. Testis weight, serum FSH, total cholesterol and blood platelets count were greater in rabbits of Groups B and C, while MCV was less in rabbits of Group C, compared to the control (P < 0.05). In conclusion, in vitro cultured cells of adenohypophysis from male buffalo calves showed FSH activity. This FSH increased testes size, serum FSH, total cholesterol and blood platelets counts and decreased MCV in rabbits. However, it had no effect on weight gain, RBC counts, WBC counts, PCV and MCH.

Total synthesis of the α-subunit of human glycoprotein hormones: toward fully synthetic homogeneous human follicle-stimulating hormone

Described herein is the first total chemical synthesis of the unique α-subunit of the human glycoprotein hormone (α-hGPH). Unlike the biologically derived glycoprotein hormones, which are isolated as highly complex mixtures of glycoforms, α-hGPH obtained by chemical synthesis contains discrete homogeneous glycoforms. Two such systems have been prepared. One contains the disaccharide chitobiose at the natural N-glycosylation sites. The other contains dodecamer oligosaccharides at these same sites. The dodecamer sugar is a consensus sequence incorporating the key features associated with human glycoproteins.

A program for ligation at threonine sites: application to the controlled total synthesis of glycopeptides

A method by which to accomplish formal threonine ligation has been developed. The method accomplishes ligations of two peptide domains. We have also demonstrated the ability to successfully ligate two independent glycopeptide domains.

Toward fully synthetic homogeneous beta-human follicle-stimulating hormone (beta-hFSH) with a biantennary N-linked dodecasaccharide. synthesis of beta-hFSH with chitobiose units at the natural linkage sites

A highly convergent synthesis of the sialic acid-rich biantennary N-linked glycan found in human glycoprotein hormones and its use in the synthesis of a fragment derived from the beta-domain of human Follicle-Stimulating Hormone (hFSH) are described. The synthesis highlights the use of the Sinay radical glycosidation protocol for the simultaneous installation of both biantennary side-chains of the dodecasaccharide as well as the use of glycal chemistry to construct the tetrasaccharide core in an efficient manner. The synthetic glycan was used to prepare the glycosylated 20-27aa domain of the beta-subunit of hFSH under a Lansbury aspartylation protocol. The proposed strategy for incorporating the prepared N-linked dodecasaccharide-containing 20-27aa domain into beta-hFSH subunit was validated in the context of a model system, providing protected beta-hFSH subunit functionalized with chitobiose at positions 7 and 24.