Leptin and prolactin reduce cryodamage in normozoospermic human semen samples during cryopreservation.

OBJECTIVES: Cryopreservation has destructive effects on the function and structure of spermatozoa. It is known that leptin and prolactin play an active role in decreasing the rates of reactive oxygen species and DNA fragmentation, as well as enhancing sperm motility. Hence, this experiment aimed to investigate the effects of leptin and prolactin as pro-survival factors on the normozoospermic human semen samples during cryopreservation. MATERIAL AND METHODS: Semen samples were collected from 15 healthy, fertile men ranging from 25 to 40 years. Cryopreservation of the samples was performed in liquid nitrogen over a period of two weeks, using five varying concentrations of leptin/prolactin, 0, 10, 100, 500, and 1000ng/ml respectively. Sperm motility, total caspase activity, and mitochondrial and cytosolic ROS were measured by flowcytometry, TUNEL, and other appropriate tests after thawing of the samples. RESULTS: Both hormones were observed to have positive effects on the motility of the samples post-cryopreservation, the highest improvement being in the 100ng/ml concentration leptin and prolactin in comparison to the control group (P=0.01 and P=0.041, respectively). A significant reduction of mitochondrial ROS was also observed in 100 and 1000ng/ml of leptin (P=0.042), and there was a considerable decrease in the cytosolic ROS in the 100ng/ml of prolactin in comparison to the control group (P=0.048). Total caspase activity was also highly reduced in the 100, 500, and 1000ng/ml of leptin compared to the control group (P=0.039). Interestingly, both hormones also significantly decreased DNA fragmentation in 1000ng/ml compared to the control group (P=0.042). CONCLUSION: It can be concluded that leptin and prolactin act as protective agents against cryodamage to spermatozoa during cryopreservation.

Effects of Endothelial and Mesenchymal Stem Cells on Improving Myocardial Function in a Sheep Animal Model.

Background: Myocardial infarction is the main cause of death worldwide. Angiogenesis, a promising new therapy for the treatment of diffuse coronary artery disease, shows a poor response to conventional revascularization techniques. This study focused on improving myocardial function using endothelial cells (ECs) and mesenchymal stem cells (MSCs) in a sheep animal model. Methods: Acute myocardial infarction was induced in 18 sheep (12 treated cases and 6 controls). Autologous MSCs and ECs were injected in the infarcted area and the border zone. Two months after transplantation, echocardiography, electron microscopy, and immunohistochemistry were performed. Results: Echocardiography in both MSC and EC groups revealed a significant improvement in the ejection fraction compared with the control group (p value < 0.05). Vascular density, estimated by antibodies against the von Willebrand factor and smooth muscle actin, increased in both study groups. The pattern of vascularity in the MSC and EC groups was diffused. The electron microscopic evaluation of the infracted areas revealed cardiomyocytes in variable stages of development in the border zone in both EC and MSC groups. Conclusion: Both ECs and MSCs were able to promote angiogenesis and improve cardiac function. Presumably, MSCs differentiate into ECs and cause angiogenesis as it occurs for ECs.

Tumor suppression effects of myoepithelial cells on mice breast cancer.

Several studies have assumed that myoepithelial cells (MECs) loss may contribute to epithelial tumor induction and/or progression. We adopted an in vitro assay and a syngeneic mice breast cancer model with histological and molecular characteristics resembling human lesions to evaluate tumor suppression effects of MECs. Flow cytometric, cell viability, blood chemistry, transmission electron microscope, immunohistochemistry and qRT-PCR assays were performed at the end of the study. We demonstrated that MECs could significantly suppress the viability of cancer cells at different time points (P<0.05). At the end of the fourth and fifth weeks, treated mice had smaller tumor volume compared with control animals. Average tumor volume was significantly less in treated groups than control group at days 21 (0.38±0.19 vs. 1.99±0.13 cm3), 28 (0.57±0.3 vs. 2.5±0.37 cm3) and 35 (0.7±0.35 vs. 2.65±0.4 cm3) after tumor cell injection (P<0.05). No hematological, hepatocellular, and renal toxicities were seen in MECs treated groups. Ultrastructural features revealed severe relationship between adjacent tumoral cells and loose interconnections of neoplastic cells in treated group. Immunohistochemical examinations of breast tumors showed high p63 and low alpha-smooth muscle actin protein expression in treated mice compared to control (P<0.05). MRNA expressions of TNF-α, smooth muscle-myosin heavy chain, connexin 43, and maspin were significantly up-regulated in breast tumor tissues in treated group compared to control (P<0.05). VEGF and alpha-smooth muscle actin mRNA expression were reduced in treated animals (P<0.05). The present study highlighted the potential tumor suppression effects of MECs on breast cancer in a typical animal model.

Retinoic Acid as the Stimulating Factor for Differentiation of Wharton's Jelly-Mesenchymal Stem Cells into Hepatocyte-like Cells.

BACKGROUND: Wharton's Jelly-Mesenchymal Stem Cells (WJ-MSCs) are pluripotent cells with differentiation capability into most cell lineages. The aim of the current work was to examine the role of Retinoic Acid (RA) in differentiation process of these cells into hepatocyte-like cells and determine the morphological and functional patterns. METHODS: Human WJ-MSCs were extracted, cultured and expanded; after approximately 95% of confluence, the cells were treated with hepatogenic media containing RA. The cells were subsequently analyzed for morphological changes, glycogen storage, albumin production, and specific gene expression. RESULTS: WJ-MSCs expressed high levels of CD90 (93.6%) and CD105 (90.7%), but low levels of CD34 (0.3%) and CD45 (0.8%). Albumin production had significant difference in the two groups (p≤0.05). The data showed specific characteristics in favor of considering the differentiated cells as hepatocyte-like cells such as obtaining morphologic, functional, and αFP and HNF1-α expression patterns which in turn were higher in cells exposed to RA. CONCLUSION: Based on the data of present study, RA is an effective molecule in inducing differentiation of WJ-MSCs into hepatocyte-like cells; therefore, it may be considered as a promising factor for targeting therapy of liver disorders.

Differentiation of human umbilical cord matrix-derived mesenchymal stem cells into germ-like cells.

BACKGROUND: Mesenchymal Stem Cells (MSCs) are multipotent cells that can be collected from different sources. Under specific conditions, MSCs can be differentiated to tissue specific cells in vitro. Human Umbilical Cord mesenchymal Stem Cells (hUCMSCs) can easily be harvested and cultured in in vitro conditions. Production of germ cells from mesenchymal stem cells is a very interesting and promising area in the field of reproductive medicine. In the present study, the possible trans-differentiation of hUCMSCs into Primordial like Germ Cell (PGC) was performed in vitro under specific condition. METHODS: Human umbilical cord mesenchymal stem cells were cultured and expanded in DMEM medium containing 10% FBS. The cultured cells were studied for differentiation ability to adipocytes and osteocytes. Furthermore, MSCs related markers were identified by flow cytometry method. For PGC differentiation, hUCMS cells were cultured in differentiation medium containing Bone Morphogenetic Protein 4 (BMP4) and it was followed by retinoic acid (RA). Real time PCR and immunocytochemistry analysis were performed to evaluate the expression of PGC specific genes and proteins, respectively. RESULTS: Our results showed that hUCMSCs cultured in the presence of BMP4 and RA are able to transdifferentiate in to PGC like cells in vitro. Real time PCR and immunocytochemistry results showed that differentiated cells expressed PGC specific markers after 14 days of culture. CONCLUSION: Based on these results, it was concluded that hUCMSC may be considered as a promising alternative cell source in reproductive medicine. More studies including laboratory and also animal models are needed to evaluate the functionality of differentiated PGCs before introducing them to clinical applications.

Immunomodulatory effects of human umbilical cord Wharton's jelly-derived mesenchymal stem cells on differentiation, maturation and endocytosis of monocyte-derived dendritic cells.

The Wharton's jelly of the umbilical cord is believed to be a source of mesenchymal stem cells (MSCs) which can be therapeutically applied in degenerative diseases.In this study, we investigated the immunomodulatory effect of umbilical cord derived-mesenchymal stem cells (UC-MSCs) and bone marrow-derived-mesenchymal stem cells (BM-MSCs) on differentiation, maturation, and endocytosis of monocyte-derived dendritic cells in a transwell culture system under laboratory conditions. Monocytes were differentiated into immature dendritic cells (iDCs) in the presence of GM-CSF and IL-4 for 6 days and then differentiated into mature dendritic cells (mDCs) in the presence of TNF-α for 2 days. In every stage of differentiation, immature and mature dendritic cells were separately co-cultured with UC-MSCs and BM-MSCs. The findings showed that UC-MSCs and BM-MSCs inhibited strongly differentiation and maturation of dendritic cells at higher dilution ratios (1:1). The BM-MSCs and UC-MSCs showed more inhibitory effect on CD1a, CD83, CD86 expression, and dendritic cell endocytic activity, respectively. On the other hand, these cells severely up-regulated CD14 marker expression. We concluded that UC-MSCs and BM-MSCs could inhibit differentiation, maturation and endocytosis in monocyte-derived DCs through the secreted factors and free of any cell-cell contacts under laboratory conditions. As DCs are believed to be the main antigen presenting cells for naïve T cells in triggering immune responses, it would be logical that their inhibitory effect on differentiation, maturation and function can decrease or modulate immune and inflammatory responses.

The role of nitric oxide, reactive oxygen species, and protein kinase C in oxytocin-induced cardioprotection in ischemic rat heart.

Ischemia-reperfusion injury is a common complication of heart disease that is the leading cause of death worldwide. Here, we plan to elucidate oxytocin cardioprotection effects against ischemia-reperfusion via nitric oxide (NO), reactive oxygen species (ROS), and protein kinase C (PKC) in anesthetized rat preconditioned myocardium. Forty-eight Sprague-Dawley rats were equally divided into eight groups. All animals were subjected to 25 min ischemia and 120 min reperfusion. Oxytocin (OT), L-NAME (LNA, a nitric oxide synthase inhibitor), chelerythrine (CHE, a PKC enzyme inhibitor), and N-acetylcysteine (NAC, a ROS scavenger) were used prior to ischemia. Results showed that mean arterial pressure significantly reduced during the first 10 min of ischemia and reperfusion in IR, LNA, CHE, and NAC groups (p<0.05). OT prevented mean arterial pressure decline during early phase of ischemia and reperfusion. Cardioprotective effects of OT in infarct size, plasma levels of creatine kinase-MB and lactate dehydrogenase, severity and incidence of ventricular arrhythmias were abolished by L-NAME, chelerythrine, and N-acetylcysteine (p<0.05). The present study showed that OT pretreatment reduces myocardial infarct size and ventricular arrhythmias, and improves mean arterial pressure via NO production, PKC activation, and ROS balance. These findings provide new insight into therapeutic strategies for ischemic heart disease.

Improvement in cardiac function following transplantation of human umbilical cord matrix-derived mesenchymal cells.

OBJECTIVES: Human umbilical cord mesenchymal cells (hUCM) can be easily obtained and processed in a laboratory. These cells may be considered as a suitable source in the repair of heart failure diseases. We, therefore, examined whether these cells may contribute to heart regeneration following an acute experimental myocardial infarction (MI). METHODS: MI-induced animals received 5 × 10(6) hUCM cells, 5 × 10(6) 5-azacytidine-treated cells (dhUCM), or PBS alone, subepicardially. A group of animals with MI and no other former intervention served as controls. dhUCM cells were assessed for F-actin, myogenin and troponin-I expression. RESULTS: dhUCM cells appeared as binucleated cells with extensive cytoplasmic processes. These differentiated cells were F-actin and myogenin positive. Thirty days after LAD ligation, left ventricular ejection fraction and the percentage of fractional shortening improved significantly in cell-receiving animals. In addition, the amount of scar tissue was significantly reduced in hUCM and dhUCM groups compared to MI group (p < 0.05). These parameters were comparable between hUCM and dhUCM groups. Histopathological evaluations revealed that some engrafted cells adjacent to and remote from the MI area expressed troponin-I, F-actin and connexin43. CONCLUSION: These findings demonstrated the potential therapeutic use of either differentiated or undifferentiated hUCM cells in treatment of heart failure conditions.