Exosomes of Endothelial Progenitor Cells Inhibit Neointima Formation After Carotid Artery Injury.

BACKGROUND: Exosomes released from endothelial progenitor cells (EPCs) play a protective role in various disease models. Both endothelial cell (EC) damage and smooth muscle cell (SMC) proliferation are involved in the pathological process of restenosis after angioplasty and stenting. Few studies have focused on the therapeutic role of exosomes in EC damage and SMC proliferation. In this study, we sought to investigate the effect of exosomes released by human fetal aorta-derived EPCs on the rat carotid artery balloon injury model in vivo. We also sought to determine the effect of exosomes on both ECs and SMCs in vitro. METHODS: Exosomes (Exo group) or saline (Con group) were injected in rat carotid balloon injury model animals. The rats were sacrificed after 2, 4, 14, and 28 d, and injured carotid specimens were collected for Evans blue staining, hematoxylin-eosin staining, and immunohistochemistry. RESULTS: When the Con group and the Exo group were compared, the reendothelialized areas were not significantly different after 2 or 4 d, as shown by Evans blue staining. The hematoxylin-eosin results showed that the intimal to medial area ratio was slightly but not significantly higher in the Exo group after 2 and 4 d. The immunohistochemistry results showed that the proliferation of SMCs was slightly higher in the Exo group after 2 and 4 d, but the difference was not significant. The reendothelialization area of the Con group was significantly smaller than that of the Exo group at day 14. Both the intimal to medial area ratio and SMC proliferation in the Exo group were significantly smaller than those of the Con group at 14 or 28 d. In the in vitro study, exosome treatment significantly enhanced the proliferation and migration of both ECs and SMCs. CONCLUSIONS: Exosomes derived from EPCs could inhibit neointimal hyperplasia after carotid artery injury in rats. The protective effect of exosomes may manifest through the promotion of EC repair rather than direct suppression of proliferation and migration of smooth muscles cells.

First trimester miscarriage evaluation.

Miscarriage is a relatively common occurrence for otherwise healthy women. Despite its frequency, evaluation for cause is rare. The most common cause of miscarriage is sporadic chromosome errors. Chromosomal analysis of the miscarriage offers an explanation in at least 50% of cases. Conventional cytogenetic evaluation can only be done on fresh tissue, so it is critical that the treating physician consider genetic testing at the time of the miscarriage. Ultrasound can estimate the gestational age at the time of miscarriage and identify major abnormalities in some embryos. A careful pathological examination can add to the evaluation by ruling out rare disorders with the highest recurrence risk. A multidisciplinary approach to miscarriage evaluation is essential to understanding the cause and risk of recurrence. A thorough evaluation of a miscarriage, in combination with emotional support, can often provide the necessary reassurance and confidence as the patient prepares for her next pregnancy.

Umbilical cord hypercoiling and thinning: a rare cause of intrauterine death in the second trimester of pregnancy.

Little attention has been paid to the pathologic features of the umbilical cord, which might fatally damage the fetus. We determined the association of hypercoiling (more than 1 coil per 5 cm) and thinning with consecutive constriction of the umbilical vessels (thin cord syndrome; TCS) and intrauterine fetal death (IUFD). Three hundred and three cases of consecutive fetal autopsies over a 5-year period, including spontaneous and induced abortions of the 2nd trimester of pregnancy, were examined using a standardized protocol. The mean maternal age was 28.5 years and the mean gestational age was 19.1 weeks (range: 12.6 to 24.5 weeks). Thirty-six percent of all cases were induced abortions because of congenital malformations, and 8.9% resulted from legal abortions, as regulated by German law. One hundred sixty-seven cases (55.1%) were spontaneous abortion specimens. The leading cause for IUFD in the spontaneous abortion group was an amnion infection (34.7%), followed by abruptio placentae (15.6%). In 25.1% of cases, placental dysmaturity with consecutive placental insufficiency was responsible for IUFD. Pathologies of the umbilical cord as the cause of IUFD were seen in 10.2% of the cases. Most of these cases (15/17) involved TCS. In 14.4% of all spontaneous abortion specimens the cause of IUFD could not be determined by autopsy. There was an apparent difference in the frequency of TCS in the spontaneous abortion group (15/167 = 9%) compared to the nonspontaneous group (2/136 = 1.5%). A remarkably high percentage (17/303 = 5.6%) of all cases showed TCS. In cases of spontaneous abortions, TCS was causative for intrauterine death in 9% of cases (15/167). Careful pathologic examination of the umbilical cord is recommended to detect TCS and to reduce the cases with unexplained intrauterine death.

A comparison in concentration of heat shock proteins (HSP) 70 and 90 on chorionic villi of human placenta in normal pregnancies and in missed miscarriages.

PURPOSE: To investigate the role of heat shock protein (HSP) on the chorionic villi of human placental cells and to compare the concentration of placental HSP70 & 90 in term deliveries and in missed miscarriages. MATERIALS AND METHODS: Fifty products of conception from women who experienced first trimester missed miscarriage and 50 placentas from women who gave birth at term were studied. An immunohistochemical investigation was carried out with which we marked the localization of heat shock proteins 70 and 90 on the syncytiotrophoblastic, cytotrophoblastic, stromal and blood vessel cells, using specific antibodies which can detect the presence of those proteins on light microscopy. We compared their expression with the normal placental tissue of term pregnancies and with material acquired from first trimester missed miscarriages. An indirect immunoperoxidase method was applied using polyclonal antibodies against HSP70 and HSP90 on formalin-fixed paraffin-embedded tissues. RESULTS: Expression of HSP90B was increased in chorionic villi of first trimester missed miscarriages concerning syncytiotrophoblasts, cytotrophoblasts, vessel and stroma cells compared to full-term placentas. There was a statistically significant increase of HSP90A expression in chorionic villi of first trimester missed miscarriages, concerning only the cytotrophoblast cells, compared to full-term placentas. Expression of HSP70 cognate protein was significantly increased in chorionic villi of first trimester missed miscarriages, concerning syncytiotrophoblastic cells only, compared to full-term placentas. Finally, HSP70 inducible protein was significantly increased in chorionic villi of first trimester missed miscarriages concerning syncytiotrophoblasts, cytotrophoblasts, vessel and stroma cells compared to full-term placentas. CONCLUSIONS: The results of the present study have sufficiently shown that there is an increase of HSP70 & 90 expression in chorionic villi of first trimester missed miscarriages compared to full-term placentas and this increase may have an important implication on the miscarriage process.