Elimination of Signaling by the Luteinizing Hormone Receptor Reduces Ocular VEGF and Retinal Vascularization during Mouse Eye Development

Can Serum Biomarker Values from Second-Trimester Aneuploidy Screening Predict the development of Retinopathy of Prematurity in Premature Infants?

Objectives

This study aimed to evaluate serum biomarker values measured during second-trimester aneuploidy screening in terms of their predictive ability for the development of retinopathy of prematurity (ROP) in premature infants.

Methods

This retrospective cohort study evaluated the data of 1985 idiopathic premature infants who underwent ROP screening from 2016 to 2022. The infants were divided into two groups according to the presence of ROP, and those with ROP were further evaluated in two subgroups based on the presence of proliferation. Comparisons were made concerning the serum multiple of the median values of unconjugated estriol (uE3), human chorionic gonadotropin (hCG), and alpha-fetoprotein (AFP) among aneuploidy screening biomarkers.

Results

While 1628 premature infants were in the non-ROP group, 357 were in the ROP group. Of the infants with ROP, 72 were in the proliferative ROP group and 285 in the non-proliferative ROP group. There was no significant difference in the multiple of the median values of the evaluated serum biomarkers (uE3, hCG, and AFP) between the ROP and non-ROP groups or between the proliferative ROP, non-proliferative ROP, and non-ROP groups.

Conclusion

The multiple of the median values of second-trimester aneuploidy screening serum biomarkers were not able to predict the development of ROP in premature infants. This result may have been caused by the fact that the blood tests were taken only once and in the same weeks.

Is There a Relationship Between First-Trimester Aneuploidy Screening Serum Biomarker Values and Nuchal Translucency Measurements and the Development of Retinopathy of Prematurity (ROP) in Premature Infants?

Purpose The purpose of this study is the evaluation of serum biomarker and nuchal translucency (NT) values measured during first-trimester aneuploidy screening in terms of the development of retinopathy of prematurity (ROP) in premature infants and investigation of whether the development of ROP is associated with these parameters. Methods In this retrospective cohort study, 3,750 premature infants who underwent ROP screening from 2016 to 2021 were identified from the hospital medical record system. Among 2,130 premature babies screened for first-trimester aneuploidy, 166 babies whose mothers had single pregnancies were screened by the same method and showed the same clinical course in both eyes were included in the study. The infants were divided into two groups according to the presence of ROP, and those with ROP were further evaluated in two groups according to the presence of proliferation. The groups were compared in terms of the serum values of human chorionic gonadotropin and pregnancy-associated plasma protein A, among aneuploidy screening biomarkers, and NT measurements. Results There was no significant difference in the evaluated serum biomarker values and NT measurements between the ROP and non-ROP groups or between the proliferative ROP, non-proliferative ROP, and non-ROP groups. Conclusion Our results showed that first-trimester aneuploidy screening serum biomarker values and NT measurements were not associated with the development of ROP in premature infants.

Characteristics of retinal image associated with premature ovarian insufficiency: a case- control study

PURPOSE

To establish an early clinical diagnosis model based on the retinal vascular features associated with POI, supplying a non-invasive way for accurately and early predicted the risk of POI.

METHODS

A total of 78 women with spontaneous POI and 48 healthy women were recruited from the Affiliated Shenzhen Maternity & Child Healthcare Hospital in the study. Retinal characteristics were analyzed using an automated retinal image analysis system. Binary logistic regression was used to identify POI cases and develop predictive models.

RESULTS

Compared to the normal group, the POI group had larger central retinal artery equivalent (CRAE) (P = 0.006), central retinal vein equivalent (CRVE) (P = 0.001), index of venules asymmetry (Vasym) (P = 0.000); larger bifurcation angles of arterioles (Aangle) (P = 0.001), bifurcation coefficient of venule (BCV) (P = 0.001) and more obvious arteriovenous nipping (Nipping) (P = 0.005), but lower arteriole-to-venule ratio (AVR) (P = 0.012). In the POI group, the odds ratio (OR) of Vasym was 6.72e-32 (95% C.I. 4.62e-49-9.79e-15, P = 0.000), the OR of BCV was 5.66e-20 (95% C.I. 1.93e-34-.0000, P = 5.66e-20) and the OR of Nipping was 6.65e-06 (95% C.I. 6.33e-10-.0698, P = 0.012). Moreover, the area under the ROC curve for the binary logistic regression with retinal characteristics was 0.8582, and the fitting degree of regression models was 60.48% (Prob > chi-square = 0.6048).

CONCLUSION

This study demonstrated that retinal image analysis can provide useful information for POI identification and certain characteristics may help with early clinical diagnosis of POI.

Luteinizing hormone receptor promotes angiogenesis in ovarian endothelial cells of Macaca fascicularis and Homo sapiens†

Angiogenesis within the ovarian follicle is an important component of ovulation. New capillary growth is initiated by the ovulatory surge of luteinizing hormone (LH), and angiogenesis is well underway at the time of follicle rupture. LH-stimulated follicular production of vascular growth factors has been shown to promote new capillary formation in the ovulatory follicle. The possibility that LH acts directly on ovarian endothelial cells to promote ovulatory angiogenesis has not been addressed. For these studies, ovaries containing ovulatory follicles were obtained from cynomolgus macaques and used for histological examination of ovarian vascular endothelial cells, and monkey ovarian microvascular endothelial cells (mOMECs) were enriched from ovulatory follicles for in vitro studies. mOMECs expressed LHCGR mRNA and protein, and immunostaining confirmed LHCGR protein in endothelial cells of ovulatory follicles in vivo. Human chorionic gonadotropin (hCG), a ligand for LHCGR, increased mOMEC proliferation, migration and capillary-like sprout formation in vitro. Treatment of mOMECs with hCG increased cAMP, a common intracellular signal generated by LHCGR activation. The cAMP analog dibutyryl cAMP increased mOMEC proliferation in the absence of hCG. Both the protein kinase A (PKA) inhibitor H89 and the phospholipase C (PLC) inhibitor U73122 blocked hCG-stimulated mOMEC proliferation, suggesting that multiple G-proteins may mediate LHCGR action. Human ovarian microvascular endothelial cells (hOMECs) enriched from ovarian aspirates obtained from healthy oocyte donors also expressed LHCGR. hOMECs also migrated and proliferated in response to hCG. Overall, these findings indicate that the LH surge may directly activate ovarian endothelial cells to stimulate angiogenesis of the ovulatory follicle.

Seasonal expressions of VEGF and its receptors VEGFR1 and VEGFR2 in the prostate of the wild ground squirrels (<em>Spermophilus dauricus</em>)

As a vital male accessory reproductive gonad, the prostate requires vascular endothelial growth factors for promoting its growth and development. In this study, we investigated the localizations and expressions of vascular endothelial growth factor (VEGF) and its receptors including VEGF-receptor1 (VEFGR1) and VEGF-receptor2 (VEGFR2) in the prostate of the wild ground squirrels during the breeding and the non-breeding seasons. The values of total prostate weight and volume in the breeding season were higher than those in the non-breeding season. Histological observations showed that the exocrine lumens of the prostate expanded in the breeding season and contracted in the non-breeding season. The mRNA expression levels of VEGF and VEGFR2 in the prostate were higher in the breeding season than those in the non-breeding season, but the mRNA expression level of VEGFR1 had no significant change between the breeding and non-breeding seasons. Immunohistochemical results revealed that VEGF, VEGFR1 and VEGFR2 were presented in epithelial and stromal cells during the breeding and non-breeding seasons. In addition, the microvessels of the prostate were widely distributed and the number of microvessels increased obviously in the breeding season, while decreased sharply in the non-breeding season. These results suggested that expression levels of VEGF and VEGFR2 might be correlated with seasonal changes in morphology and functions of the prostate, and VEGF might serve as pivotal regulators to affect seasonal changes in the prostate functions of the wild male ground squirrels via an autocrine/paracrine pathway.

Assessment of the retinal and choroidal microvascularization in polycystic ovary syndrome: an optical coherence tomography angiography study

PURPOSE

To examine the retinal, peripapillary, choroidal microvascularization and the choroid thickness (CT) of the patients with polycystic ovary syndrome (PCOS) using optical coherence tomography angiography (OCT-A) and compare the results to measurements obtained from healthy controls.

METHODS

In total, 47 eyes of 47 patients recently diagnosed with PCOS and 47 eyes of 47 age-matched healthy women were included in this study. An RT XR Avanti instrument with AngioVue software was used for the OCT-A imaging using 6 × 6 mm macular and 4.5 × 4.5 mm optic nerve head scans. Quantitative vessel density results of superficial capillary plexus (SCP), deep capillary plexus (DCP) and radial peripapillary capillaries (RPC); flow area and flow density of choriocapillaris; and foveal avascular zone (FAZ) area were analyzed. CT was evaluated by using the measurements obtained from the subfoveolar area.

RESULTS

No significant differences were detected between the groups for any of vessel density results for the SCP, DCP, and RPC as well as the FAZ area. The difference in the choriocapillaris flow area and flow density between the groups was not statistically significant. The choroid was significantly thicker in women with PCOS than in the healthy group (p = 0.002).

CONCLUSION

Retinal and choroidal microvascularization was comparable between the women who were evaluated early after diagnosed with PCOS and age-matched healthy controls. Choroid was found thicker in patients with PCOS than in healthy women. OCT-A, as a new and noninvasive imaging method, may help in understanding the effect of PCOS on the posterior segment of the eye.

The Risk Factors for Diabetic Retinopathy in a Chinese Population: A Cross-Sectional Study

AIMS

Epidemiological data on diabetic retinopathy (DR) in Chinese population is still rather scarce, and risk factors for diabetic retinopathy are inconsistent because of study designs, grading standards, and population samples.

MATERIALS AND METHODS

This hospital-based retrospective study included 1052 type 2 diabetes patients. Diabetic retinopathy was diagnosed by nonmydriatic fundus photography and/or fundus examination apparatus. Logistic regression analysis was performed to evaluate the risk of diabetic retinopathy.

RESULTS

A total of 352 (33.5% prevalence) subjects were diagnosed with diabetic retinopathy based on our population. The patients in the DR group not only had significantly higher hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), urinary microalbumin-creatinine ratio (ACR), and systolic blood pressure but also had higher follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) levels compared to those in the non-DR group. Moreover, we confirmed that diabetes duration and HbA1c are strongly associated with DR risk. We also found that serum LH was an independent risk factor in male diabetic retinopathy patients (OR = 1.086, 95% CI 1.024-1.152), and the levels of LH were significantly associated with diabetic retinopathy prevalence (P = 0.018).

CONCLUSIONS

Our study strengthens the argument that diabetes duration and HbA1c are risk factors for patients with DR. Additionally; we firstly confirmed that serum LH was an independent risk factor in male diabetic retinopathy patients.

Glycoprotein G-protein Coupled Receptors in Disease: Luteinizing Hormone Receptors and Follicle Stimulating Hormone Receptors

Signal transduction by luteinizing hormone receptors (LHRs) and follicle-stimulating hormone receptors (FSHRs) is essential for the successful reproduction of human beings. Both receptors and the thyroid-stimulating hormone receptor are members of a subset of G-protein coupled receptors (GPCRs) described as the glycoprotein hormone receptors. Their ligands, follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and a structurally related hormone produced in pregnancy, human chorionic gonadotropin (hCG), are large protein hormones that are extensively glycosylated. Although the primary physiologic functions of these receptors are in ovarian function and maintenance of pregnancy in human females and spermatogenesis in males, there are reports of LHRs or FSHRs involvement in disease processes both in the reproductive system and elsewhere. In this review, we evaluate the aggregation state of the structure of actively signaling LHRs or FSHRs, their functions in reproduction as well as summarizing disease processes related to receptor mutations affecting receptor function or expression in reproductive and non-reproductive tissues. We will also present novel strategies for either increasing or reducing the activity of LHRs signaling. Such approaches to modify signaling by glycoprotein receptors may prove advantageous in treating diseases relating to LHRs or FSHRs function in addition to furthering the identification of new strategies for modulating GPCR signaling.

The association between high levels of luteinizing hormone and proliferative retinopathy of prematurity in female preterm infants

BACKGROUND

Luteinizing hormone (LH) and human chorionic gonadotropin (hCG), generally considered reproductive hormones, have potent proangiogenic properties. Both of these hormones and their joint receptor (CG/LH receptor) are found in the human eye. We hypothesized that an excess of these hormones is associated with proliferative retinopathy of prematurity (P-ROP).

METHODS

Dried blood spots (DBS) were used to perform a cross-sectional study of infants (gestational age of <26 weeks) with and without P-ROP, born in Michigan between August 1, 2012, and March 15, 2015. The DBS were collected at 1 week and 4 weeks of age from 45 preterm infants (27 no-ROP and 18 P-ROP). The DBS were linked to hospital records and then deidentified. ICD-9 codes were used to identify P-ROP cases. Hormones levels were measured via electrochemiluminescence assays on the Meso Scale Discovery platform. Associations between hormone levels at 1 and 4 weeks of age and the presence or absence of P-ROP were assessed.

RESULTS

In female infants, we noted a trend toward higher LH levels in ROP cases at week 1 (P = 0.11) and significantly higher LH levels in cases at week 4 (P = 0.03). In male infants, no ROP-related differences in LH levels were found at either time point. For hCG levels, no associations with P-ROP were found in either sex at either time point.

CONCLUSIONS

The association of high LH with P-ROP in female but not male infants raises the possibility that there are sex-specific hormonal determinants of aberrant retinal angiogenesis.

The potential effect of human chorionic gonadotropin on vasoproliferative disorders of the immature retina

Human chorionic gonadotropin (hCG) is known to be a powerful vascular endothelial growth factor (VEGF)-regulating hormone. It stimulates vascularization of the gravid uterus by upregulating VEGF expression. In the body, hCG activates the same receptor as luteinizing hormone (LH). Like hCG, LH is also strongly proangiogenic. Recently, it has been shown that LH/hCG receptors are present in the retina and that both LH and hCG are found in the eye. In fact, the human eye can synthesize its own hCG. We have previously shown that LH and VEGF are significantly correlated in mammalian eyes, potentially implicating LH-receptor/hCG-receptor activation in intraocular VEGF regulation. Given that elevated VEGF is associated with progression of two vasoproliferative pediatric retinal disorders, retinopathy of prematurity and retinoblastoma, our objective was to determine whether hCG may potentially affect VEGF production and pathologic retinal vascularization in vasoproliferative disorders affecting the immature retina. In this study, we used (a) oxygen-induced retinopathy mouse model (standard model for retinopathy of prematurity) and (b) Y79 retinoblastoma cells (a human cell line derived from immature retinal cells). In the oxygen-induced retinopathy model, number of preretinal nuclei (representing pathologic retinal neovascularization) significantly increases by 57% (P<0.05) in hCG-treated mice. In Y79 cells, VEGF production significantly increases by 37% (P<0.05) in hCG-treated cells. These findings suggest that hCG is potentially able to influence retinal vascularization and VEGF production and thus, the hCG receptor may potentially represent a therapeutic target for vasoproliferative retinal disorders affecting the young eye.