Epithelial to mesenchymal transition (EMT) is a critical cellular process that has been well characterized during embryonic development and cancer metastasis and it also is implicated in several ...physiological and pathological events including embryonic stem cell differentiation. During early stages of differentiation, human embryonic stem cells pass through EMT where deeper morphological, molecular and biochemical changes occur. Though initially considered as a decision between two states, EMT process is now regarded as a fluid transition where cells exist on a spectrum of intermediate states. In this work, using a CRISPR interference system in human embryonic stem cells, we describe a molecular characterization of the effects of downregulation of E-cadherin, one of the main initiation events of EMT, as a unique start signal. Our results suggest that the decrease and delocalization of E-cadherin causes an incomplete EMT where cells retain their undifferentiated state while expressing several characteristics of a mesenchymal-like phenotype. Namely, we found that E-cadherin downregulation induces SNAI1 and SNAI2 upregulation, promotes MALAT1 and LINC-ROR downregulation, modulates the expression of tight junction occludin 1 and gap junction connexin 43, increases human embryonic stem cells migratory capacity and delocalize β-catenin. Altogether, we believe our results provide a useful tool to model the molecular events of an unstable intermediate state and further identify multiple layers of molecular changes that occur during partial EMT.
Microplastics are among the major environmental problems to be addressed because it is beginning to affect food chains and is also reaching human populations. The present study investigated the size, ...color, shape and abundance of microplastics in juvenile silversides (Atheriniformes) belonging to the edible species Odontesthes bonariensis, Odontesthes nigricans and Odontesthes argentinensis from shallow coastal waters. While 100 % of the sampled individuals presented microplastics in stomach contents, fibers were 95 %. There is a correlation between the size of the individuals and the maximum particle size ingested ranging from 0.2 to 1.2 mm. There is no significant difference in the number of particles ingested per individual. The plastic particles had a lower density than seawater, which is why they floated on the surface. These results imply that the protected areas of large ocean currents increase the exposure of local fauna to microplastics increasing the risk of ingestion of PMs.
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Microplastics are one of the major environmental issues that need to be addressed because they are starting to impact food chains and are also affecting human populations. The size, colour, form, and ...abundance of microplastics in young blennies of the species Eleginops maclovinus were examined in the current study. While the stomach contents of 70 % of the studied individuals contained microplastics, 95 % of them included fibres. Individual size and the largest particle size that can be eaten, which ranges between 0.09 and 1.5 mm present no statistical correlation. The quantity of particles taken in by each individual does not change with size. The most present microfibers colours were blue and red. Sampled fibres were analysed with FT-IR and no natural fibres were detected, proving the synthetic origin of the detected particles. These findings suggest that protected coastlines create conditions that favour the encounter of microplastics increasing local wildlife exposure to microplastics, raising the danger of their ingestion with potential physiological, ecological, economical and human health consequences.
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•Benthic fishes ingested microplastics independently of the size.•Plastics were present in 70 % of the studied individuals.•Microfibers were the predominant for of plastic in gut content.
Cell plasticity is crucial in cloning to allow an efficient nuclear reprogramming and healthy offspring. Hence, cells with high plasticity, such as multipotent mesenchymal stem cells (MSCs), may be a ...promising alternative for horse cloning. In this study, we evaluated the use of bone marrow-MSCs (BM-MSCs) as nuclear donors in horse cloning, and we compared the in vitro and in vivo embryo development with respect to fibroblasts.
Zona-free nuclear transfer was performed using BM-MSCs (MSC group, n=3432) or adult fibroblasts (AF group, n=4527). Embryos produced by artificial insemination (AI) recovered by uterine flushing and transferred to recipient mares were used as controls (AI group).
Blastocyst development was higher in the MSC group than in the AF group (18.1% vs 10.9%, respectively;
<0.05). However, pregnancy rates and delivery rates were similar in both cloning groups, although they were lower than in the AI group (pregnancy rates: 17.7% 41/232 for MSC, 12.5% 37/297 for AF and 80.7% 71/88 for AI; delivery rates: 56.8% 21/37, 41.5% 17/41 and 90.1% 64/71, respectively). Remarkably, the gestation length of the AF group was significantly longer than the control (361.7±10.9 vs 333.9±8.7 days), in contrast to the MSC group (340.6±8.89 days). Of the total deliveries, 95.2% (20/21) of the MSC-foals were viable, compared to 52.9% (9/17) of the AF-foals (
<0.05). In addition, the AF-foals had more physiological abnormalities at birth than the MSC-foals; 90.5% (19/21) of the MSC-delivered foals were completely normal and healthy, compared to 35.3% (6/17) in the AF group. The abnormalities included flexural or angular limb deformities, umbilical cord enlargement, placental alterations and signs of syndrome of neonatal maladjustment, which were treated in most cases.
In summary, we obtained 29 viable cloned foals and found that MSCs are suitable donor cells in horse cloning. Even more, these cells could be more efficiently reprogrammed compared to fibroblasts.
Immunosuppressants are necessary to prevent graft rejection after solid organ transplantation. However, they are also known to have significant side effects, including endothelial toxicity. ...Endothelial progenitor cells originate in the bone marrow and are recognized by their angiogenic and endothelial reparative properties. The effects of the immunosuppressants cyclosporine A (CyA), tacrolimus and rapamycin were analyzed on endothelial progenitor‐like cells. Rapamycin induced rapid cell death, even at concentrations much lower than those used clinically, in peripheral blood mononuclear cells (PBMC) cultured to favor outgrowth of endothelial progenitors. Cyclosporine A and tacrolimus had no significant effects at clinical concentrations. The effect of rapamycin was specific to endothelial progenitor cells, in particular to the early stages of differentiation, as a lesser effect was observed in late outgrowth endothelial progenitors, mature aortic endothelial cells, and macrophages derived from the same PBMCs. The mechanism of cell death appeared to be apoptosis; however, its induction was probably multifactorial and did not depend on caspase or cathepsin activation. In conclusion, rapamycin induces endothelial progenitor cell death, possibly because it blocks survival signals given by growth factors critically required by these cells.
This in vitro study of human peripheral blood mononuclear cells found that sirolimus, but not cyclosporine or tacrolimus, induced endothelial cell progenitor death, possibly by blocking survival signals for growth factors.
Thromboembolism has been reported as a frequent complication after cardiac transplantation. Many risk factors for thrombosis may explain this, such as metabolic alterations and the use of ...cyclosporine. In the general population, two single nucleotide polymorphisms (SNPs), factor V Leiden and prothrombin G20210A (PT G20210A), have been associated with a significant increase in the risk of thrombosis. However, these mutations have not been analyzed in cardiac transplant patients. We describe the protracted history of recurrent thromboembolism in a rare case of homozygosity for the PT G20210A variant. This prompted us to analyze the entire cardiac transplant cohort for the incidence of thromboembolic events and their association with these genetic polymorphisms.
We report the study of 84 cardiac transplant recipients. We retrospectively analyzed the frequency of thromboembolic episodes. The genotypes for FVL and PT G20210A were determined and correlated with those episodes.
Our results confirm a very high incidence of thromboembolism in this population. We also found a significant increase in the likelihood of thromboembolism in subjects with the PTB G20210A variant (odds ratio 3.08; 95% confidence interval: 1.7-5.5).
The incidence of thromboembolic complications after heart transplantation is increased and may be related in part to genetic predisposition.
Cardiac allograft vasculopathy (CAV) is a major factor limiting long-term survival after cardiac transplantation. CAV is an accelerated form of coronary artery disease (CAD) that is characterized by ...concentric fibrous intimal hyperplasia along the length of coronary vessels. Both immunologic and nonimmunologic risk factors contribute to the development of CAV by causing endothelial dysfunction and injury eventually leading to progressive intimal thickening. The diagnosis of CAV remains a challenge as angiography, the standard method for detecting focal plaques, lacks sensitivity in detecting CAV, and intravascular ultrasonography, a more sensitive method, lacks the ability to evaluate the entire coronary tree. The disease is difficult to treat and results in significant morbidity and mortality. Since treatment of CAV is limited and usually involves repeat transplantation, prevention or mitigation of immunologic and nonimmunologic risk factors is critically important. CAV prevention may involve therapy that provides protection against endothelial injury implemented just before transplantation, during storage and transplantation as well as after transplantation. This review addresses the frequency of occurrence, pathophysiology, diagnosis and treatment of CAV, highlighting areas of active research.
Cyclosporine 2-hour post-dose (C2) monitoring is predictive of outcomes in solid-organ transplants. The purpose of this study was to determine C2 levels at various time points after heart ...transplantation and determine whether trough (C0) or C2 better predicts clinical outcomes.
This was a 2-phase prospective study with paired determinations of cyclosporine levels at C0 and C2 in 58 heart transplant patients (46 men; mean age, 56 years). Phase I (6-month follow-up): cyclosporine monitored according to C0 levels (C2 blinded). Phase II (6-month follow-up): cyclosporine monitored according to C2 levels (C0 blinded). Clinical outcomes assessed were severe infections, rejection score, and renal dysfunction.
No differences were observed in renal function between the phases. In Phase I, 8 infections (4 severe) and in Phase II, 6 infections (2 severe) were detected. During Phase I, the C0 levels did not correlate (p = .96) with the presence (195 +/- 121 ng/ml) or not (197 +/- 100 ng/ml) of rejection. During Phase II, C0 levels did not correlate (p = .88) with the presence (204 +/- 85 ng/ml) or not (209 +/- 138 ng/ml) of rejection. During Phase I, C2 levels did correlate (p = 0.022) with the presence (777 +/- 326 ng/ml) or not (1,015 +/- 422 ng/ml) of rejection. During Phase II, higher C2 levels showed a significant correlation (p = 0.03) with no rejection (967 +/- 470 ng/ml vs 765 +/- 297 ng/ml, no rejection vs rejection, respectively).
High C2 levels were associated with less episodes of acute cellular rejection in patients post-heart transplantation. Monitoring with C2 levels is feasible and safe in terms of preservation of renal function and infection rates.
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