The role played by granulocyte colony stimulating factor (G-CSF) on women submitted to in vitro fertilization associated with thin endometrium: systematic review

Bioactive peptides and proteins for tissue repair: microenvironment modulation, rational delivery, and clinical potential

Bioactive peptides and proteins (BAPPs) are promising therapeutic agents for tissue repair with considerable advantages, including multifunctionality, specificity, biocompatibility, and biodegradability. However, the high complexity of tissue microenvironments and their inherent deficiencies such as short half-live and susceptibility to enzymatic degradation, adversely affect their therapeutic efficacy and clinical applications. Investigating the fundamental mechanisms by which BAPPs modulate the microenvironment and developing rational delivery strategies are essential for optimizing their administration in distinct tissue repairs and facilitating clinical translation. This review initially focuses on the mechanisms through which BAPPs influence the microenvironment for tissue repair via reactive oxygen species, blood and lymphatic vessels, immune cells, and repair cells. Then, a variety of delivery platforms, including scaffolds and hydrogels, electrospun fibers, surface coatings, assisted particles, nanotubes, two-dimensional nanomaterials, and nanoparticles engineered cells, are summarized to incorporate BAPPs for effective tissue repair, modification strategies aimed at enhancing loading efficiencies and release kinetics are also reviewed. Additionally, the delivery of BAPPs can be precisely regulated by endogenous stimuli (glucose, reactive oxygen species, enzymes, pH) or exogenous stimuli (ultrasound, heat, light, magnetic field, and electric field) to achieve on-demand release tailored for specific tissue repair needs. Furthermore, this review focuses on the clinical potential of BAPPs in facilitating tissue repair across various types, including bone, cartilage, intervertebral discs, muscle, tendons, periodontal tissues, skin, myocardium, nervous system (encompassing brain, spinal cord, and peripheral nerve), endometrium, as well as ear and ocular tissue. Finally, current challenges and prospects are discussed.

The Effect of Granulocyte Colony-Stimulating Factor on Endometrial Receptivity of Implantation Failure Mouse

The purpose of this study was to investigate the effect of G-CSF on the endometrial receptivity of implantation failure mice. Sixty female mice were treated mifepristone to establish an implant failure model. The treatment groups received different doses of G-CSF. Endometrial tissue and serum were collected on day 5 after mating. The abundance of pinopodes on the endometrium was observed by scanning electron microscopy. The expressions of LPAR3, COX2, and HOXA10 were detected by RT-qPCR and Western blotting. Serum levels of E2, P, VEGF, LIF, TNF-α and IL-10 were measured by ELISA. The expressions of VEGF, CD34, CD57, TNF-α, and IL-10 were assessed by immunohistochemistry. Immunofluorescence analysis was performed to determine the number of CD57, Treg, and Th17 cells. G-CSF increased implantation and pregnancy rates of mifepristone-induced implantation failure mice, with the most significant effect seen at the intermediate dose. G-CSF increased the serum levels of E2 and P, the abundance of endometrial pinopodes, and the level of LIF in the endometrium. It also promoted the expression of VEGF, HOXA10, LPAR3, and COX2. Moreover, G-CSF reduced the level of CD57 cells and the ratio of Th17/Treg cells in endometrium. G-CSF reduced the inflammatory factor TNF-α, but IL-10 did not change significantly. G-CSF can enhance embryo implantation rate and pregnancy rate and improve endometrial receptivity by attenuating degeneration of pinopodes, upregulating estrogen and progesterone, facilitating angiogenesis, maintaining immune cell homeostasis, and reducing the production of inflammatory cytokines in implantation failure mouse.

Efficacy of granulocyte colony-stimulating factor for infertility undergoing IVF: a systematic review and meta-analysis

OBJECTIVE

This study aimed to evaluate the effectiveness of granulocyte colony-stimulating factor (G-CSF) for infertility and recurrent spontaneous abortion.

METHODS

Existing research was searched in PubMed, Embase and Cochrane Library till Dec 2021. Randomized control trials (RCTs) that compared G-CSF administration with the control group in infertility women undergoing IVF were included. The primary outcomes included clinical pregnancy rate; the secondary outcomes included live birth rate, abortion ratebiochemical pregnancy rate, embryo implantation rate, as well as endometrial thickness.

RESULT(S)

20 RCTs were included in this study. G-CSF increased the clinical pregnancy rate (RR = 1.85; 95% CI: 1.07, 3.18) and the endometrial thickness (MD = 2.25; 95% CI: 1.58,2.92;) in patients with thin endometrium undergoing IVF. G-CSF increased the biochemical pregnancy rate (RR = 2.12; 95% CI: 1.54, 2.93), the embryo implantation rate (RR = 2.51; 95% CI: 1.82, 3.47) and the clinical pregnancy rate (RR = 1.93; 95% CI: 1.63, 2.29) in patients with a history of repeated implantation failure undergoing IVF. No differences were found in pregnancy outcomes of general IVF patients.

CONCLUSIONS

Granulocyte colony-stimulating factor is likely to be a potential option for infertility women undergoing IVF with thin endometrium or recurrent implantation failure .

TRIAL REGISTRATION

Retrospectively registered (The PROSPERO registration number: CRD42022360161).

Hormone replacement therapy alone or in combination with tamoxifen in women with thin endometrium undergoing frozen-thawed embryo transfer: A retrospective study

RESEARCH QUESTION

To investigate the effects of two protocols (hormone replacement therapy (HRT) alone or in combination with tamoxifen) on the endometrium and pregnancy outcome of patients with thin endometrium in frozen-thawed embryo transfer (FET) cycles.

DESIGN

A total of 465 infertile patients with thin endometrium who underwent FET between January 2020 to June 2021 at the Drum Tower Hospital affiliated with Nanjing University Medical School were retrospectively analyzed. A total of 187 patients were given tamoxifen in addition to HRT (TMXF-HRT group), whereas 278 patients were given only HRT (HRT group). Clinical data were compared between the two groups, including general characteristics, endometrial thickness, and clinical pregnancy outcomes.

RESULTS

There were no significant differences in baseline characteristics of all enrolled patients between two groups. Serum progesterone (P) was higher in HRT group than in the TMXF-HRT group (0.28 ± 0.53 ng/mL vs. 0.15 ± 0.25 ng/mL, P = 0.002). There was a significant increase in endometrial thickness in the TMXF-HRT group compared with the HRT group (OR: 1.54, 95% CI: 1.32-1.75, P < 0.001). There were no significant differences in the clinical pregnancy rate, embryo implantation rate, early miscarriage rate, or live birth rate between these two groups.

CONCLUSION

Although tamoxifen when used in combination with hormone replacement therapy can significantly increase endometrial thickness, it may not have a role in improving the pregnancy outcomes of patients with thin endometrium undergoing FET cycles.

Is There any Role for Granulocyte Colony Stimulating Factor in Improvement of Implantation in Intrauterine Insemination? A Prospective Double-Blind Randomized Control Trial

BACKGROUND

Granulocyte colony stimulating factor (GCSF) has been introduced as an immunomodulatory agent by increasing implantation rate in vitro fertilization (IVF) patients but it has not been studied in intrauterine insemination (IUI) patients. The aim of this study is to answer the role of GCSF in implantation rate of IUI.

MATERIALS AND METHODS

In this prospective double-blind randomized control trial, 320 eligible patients were enrolled, who were referred to the referral infertility clinic of Shiraz University of Medical Sciences from February 2018 till the end of 2019. They were divided into two groups randomly. After collecting the demographic data, all patients received clomiphene citrate from the 5th day of the menstruation cycle for 5 days. 50-150 units of recombinant purified follicle-stimulating factor (FSH) were started from the 8th day of the cycle. Follicle monitoring was done by transvaginal sonography till a mature follicle of 18 mm or more was developed. Human chorionic gonadotropin (HCG) injection was done in both groups with intrauterine administration of 300 μg GCSF in the case group and normal saline in the control group simultaneously. After 36 hours, IUI was performed. The clinical pregnancy, miscarriage, and ongoing pregnancy rates of both groups were calculated by SPSS software.

RESULTS

The results showed improvement of clinical pregnancy rate [15.38% vs. 13.81% OR=1.17 (0.62-2.21)], miscarriage rate [3.84% vs. 5.26% OR=0.74 (0.25-2.20)] and ongoing pregnancy rate [11.53% vs. 8.55% OR=1.37 (0.65-2.92)] in the GCSF group compared to the control. However, the results revealed no statistically significance (P>0.05).

CONCLUSION

Although it was not statistically significant, 300 μg Intrauterine GCSF administration simultaneously with hCG injection in standard IUI procedure might increase the pregnancy outcomes. Further studies are warranted (registration number: IRCT201212079281N2).

Vitamin D Promotes Trophoblast Cell Induced Separation of Vascular Smooth Muscle Cells in Vascular Remodeling via Induction of G-CSF

Vitamin D deficiency is associated with complications of pregnancy such as pre-eclampsia, fetal growth restriction, and miscarriage, all of which are also associated with incomplete spiral artery (SpA) remodeling. We have previously shown that both uterine natural killer (uNK) cells and extravillous trophoblast cells (EVT) are required for successful SpA remodeling, but whether their activity in this process is modulated by vitamin D is not known. In the current study, we use a previously described chorionic plate artery (CPA) ex vivo model of vascular remodeling to determine the effects of 1,25(OH)₂D treated uNK cell, placental explant (PEx), and uNK/PEx conditioned medium (CM) on vascular smooth muscle cell (VSMC) disorganization and phenotypic switching. Significant results were followed up in VSMCs in vitro. We demonstrate that 1,25(OH)₂D can enhance the ability of PEx to induce SpA remodeling, via a mechanism associated with increased secretion of granulocyte-colony stimulating factor (G-CSF). G-CSF appears able to increase VSMC disorganization and phenotypic switching in both an ex vivo vascular model and in vitro VSMC cultures. The clinical relevance of these findings are still to be determined. G-CSF may have differential effects depending on dose and vascular bed, and vitamin D may play a role in potentiating these actions. G-CSF may be an interesting potential therapeutic target for facilitating physiological vascular remodeling for the prevention of adverse obstetric outcomes.