Enhanced generation of retinal progenitor cells from human retinal pigment epithelial cells induced by amniotic fluid.

BACKGROUND: Retinal progenitor cells are a convenient source of cell replacement therapy in retinal degenerative disorders. The purpose of this study was to evaluate the expression patterns of the homeobox genes PAX6 and CHX10 (retinal progenitor markers) during treatment of human retinal pigment epithelium (RPE) cells with amniotic fluid (AF), RPE cells harvested from neonatal cadaver globes were cultured in a mixture of DMEM and Ham's F12 supplemented with 10% FBS. At different passages, cells were trypsinized and co-cultured with 30% AF obtained from normal fetuses of 1416 weeks gestational age. RESULTS: Compared to FBS-treated controls, AF-treated cultures exhibited special morphological changes in culture, including appearance of spheroid colonies, improved initial cell adhesion and ordered cell alignment. Cell proliferation assays indicated a remarkable increase in the proliferation rate of RPE cells cultivated in 30% AF-supplemented medium, compared with those grown in the absence of AF. Immunocytochemical analyses exhibited nuclear localization of retinal progenitor markers at a ratio of 33% and 27% for CHX10 and PAX6, respectively. This indicated a 3-fold increase in retinal progenitor markers in AF-treated cultures compared to FBS-treated controls. Real-time PCR data of retinal progenitor genes (PAX6, CHX10 and VSX-1) confirmed these results and demonstrated AF's capacity for promoting retinal progenitor cell generation. CONCLUSION: Taken together, the results suggest that AF significantly promotes the rate of retinal progenitor cell generation, indicating that AF can be used as an enriched supplement for serum-free media used for the in vitro propagation of human progenitor cells.

Immunohistochemical localization of endothelial nitric oxide synthase in endometrial tissue of women with unexplained infertility.

BACKGROUND: Nitric oxide (NO) is a molecule that incorporates in many physiological processes of female reproductive system. Recent studies suggested the possible role of endothelial isoform of nitric oxide synthase (eNOS) enzyme in female infertility. OBJECTIVE: The aim of this study is to evaluate the expression of endothelial nitric oxide synthase in endometrial tissue of women with unexplained infertility. MATERIALS AND METHODS: In this case-control study a total of 18 endometrial tissues obtained from 10 women with unexplained infertility and 8 normal and fertile women by endometrial biopsy, 6 to 10 days after LH surge. Specimens were fixed in 4% paraformaldhyde fixative and frozen sectioned for semi-quantitative immunohistochemical evaluation using monoclonal anti-human eNOS antibody. Hematoxilin and Eosin was used for Histological dating. RESULTS: Localization of endothelial nitric oxide synthase was seen in glandular and luminal epithelium, vascular endothelium and stroma in both fertile women and women with unexplained infertility. Although there were differences in immunoreactivity of glandular epithelium (p=0.44), vascular endothelium (p=0.60) and stroma (p=0.63) but only over-expression of eNOS in luminal epithelium (p=0.045) of women with unexplained infertility compared to fertile women was statistically significant (p<0.05). CONCLUSION: This study suggests that changes in luminal expression of eNOS may influence receptivity of endometrium.

Evaluation of RPE65, CRALBP, VEGF, CD68, and tyrosinase gene expression in human retinal pigment epithelial cells cultured on amniotic membrane.

The retinal pigment epithelium (RPE) plays a key role in the maintenance of the normal functions of the retina. Tissue engineering using amniotic membrane as a substrate to culture RPE cells may provide a promising new strategy to replace damaged RPE. We established a method of culturing RPE cells over the amniotic membrane as a support for their growth and transplantation. The transcription of specific genes involved in cellular function of native RPE, including RPE65, CRALBP, VEGF, CD68, and tyrosinase, were then measured using quantitative real-time PCR. Data showed a considerable increase in transcription of RPE65, CD68, and VEGF in RPE cells cultured on amniotic membrane. The amounts of CRALBP and tyrosinase transcripts were not affected. This may simply indicate that amniotic membrane restricted dedifferentiation of RPE cells in culture. The results suggest that amniotic membrane may be considered as an elective biological substrate for RPE cell culture.

Human amniotic fluid promotes retinal pigmented epithelial cells' trans-differentiation into rod photoreceptors and retinal ganglion cells.

To evaluate the effect of human amniotic fluid (HAF) on retinal pigmented epithelial cells growth and trans-differentiation into retinal neurons, retinal pigmented epithelium (RPE) cells were isolated from neonatal human cadaver eye globes and cultured in Dulbecco's modified Eagle's medium-F12 supplemented with 10% fetal bovine serum (FBS). Confluent monolayer cultures were trypsinized and passaged using FBS-containing or HAF-containing media. Amniotic fluid samples were received from pregnant women in the first trimester of gestation. Cell proliferation and death enzyme-linked immunosorbent assays were performed to assess the effect of HAF on RPE cell growth. Trans-differentiation into rod photoreceptors and retinal ganglion cells was also studied using immunocytochemistry and real-time polymerase chain reaction techniques. Primary cultures of RPE cells were successfully established under FBS-containing or HAF-containing media leading to rapid cell growth and proliferation. When RPE cells were moved to in vitro culture system, they began to lose their differentiation markers such as pigmentation and RPE65 marker and trans-differentiated neural-like cells followed by spheroid colonies pertaining to stem/progenitor cells were morphologically detected. Immunocytochemistry (ICC) analysis of HAF-treated cultures showed a considerable expression of Rhodopsin gene (30% Rhodopsin-positive cells) indicating trans-differentiation of RPE cells to rod photoreceptors. Real-time polymerase chain reaction revealed an HAF-dose-dependant expression of Thy-1 gene (RGC marker) and significant promoting effect of HAF on RGCs generation. The data presented here suggest that HAF possesses invaluable stimulatory effect on RPE cells growth and trans-differentiation into retinal neurons. It can be regarded as a newly introduced enriched supplement in serum-free kinds of media used in neuro-retinal regeneration studies.

Thyroid autoimmunity and recurrent spontaneous abortion in Iran: a case-control study.

OBJECTIVE: To determine the association of thyroglobulin antibodies (TG-Ab) and thyroid peroxidase antibodies (TPO-Ab) with recurrent spontaneous abortion in a euthyroid, nonpregnant population of women in Iran. METHODS: In this case-control study conducted between November 2003 and September 2006 in Tehran, Iran, nonpregnant women with a history of 3 or more consecutive pregnancy losses and age-matched, healthy parous women without a history of reproductive problems were assessed. Thyroid function tests were performed, which included assessment of thyroid-stimulating hormone, triiodothyronine, thyroxine, and the presence of TG-Ab and TPO-Ab. RESULTS: A total of 641 patients and 269 controls were included. Mean age (+/- SD) was 30.6 +/- 6.4 years (range, 16-51 years) in the patient group and 30.05 +/- 6.6 years (range, 18-48 years) in the control group. Thyroid antibodies were present in 157 of 641 patients (24.5%) and in 34 of 269 controls (12.6%) (P<.001). The presence of thyroid antibodies was significantly associated with recurrent abortion independent of the impact of age with an odds ratio of 2.24 (95% confidence interval, 1.5-3.35). CONCLUSIONS: In this population of women in Iran, TG-Ab and TPO-Ab were identified more frequently in women with recurrent abortions compared with controls, and thyroid autoimmunity was independently associated with a higher risk of recurrent abortion.