Tissue Plasminogen Activator Gene Research Articles

Preventative effects of the albumin nano tissue-type plasminogen activator gene plasmid ultrasound microbubble carrier system on thrombosis after cardiac valve replacement

Mechanical valve replacement is a new method for treating rheumatic heart valve disease. However, patients require long-term anticoagulation therapy after surgery, thus reducing their use of anticoagulants, making the prevention of postoperative thrombosis of great research interest. We examined the potential preventative effects of the albumin nano tissue plasminogen activator (tPA) gene plasmid ultrasound microbubble carrier system on thrombosis. The average particle size of the nano tPA gene plasmid was 131.8 nm, the surface zeta potential was 30.65±40.34 mV, and the encapsulation efficiency was 76.56%, all meeting experimental requirements. One month after gene integration, the tPA content of group B had increased beyond pre-integration levels and above post-integration levels of group A. After valve replacement operations, the venous blood D-Dimer (D-D) content of group B increased significantly, whereas the venous blood D-D content of group A decreased. In addition, at 1, 2, and 4 weeks after operation, the venous blood D-D content of group B was greater than that of group A. These results suggest that the prepared albumin nano tPA gene plasmid ultrasound microbubble vector system can prevent thrombosis after heart valve replacement.

Association between Alu insertion/deletion polymorphism in intron 8 of human tissue plasminogen activator gene (PLAT) and risk of age-related macular degeneration

Background/Aim: Age-related macular degeneration (AMD) is major reason of blindness in human. Plasminogen is converted to plasmin by tissue plasminogen activator protein (PLAT, formerly known as TPA). A polymorphism in intron 8 of PLAT gene has been reported, either with (insertion) or without (deletion) a 311 bp Alu sequence. This polymorphism is associated with plasma levels of glycoprotein t-PA. t-PA is expressed in the retina and is involved in the development of the eye. It can be hypothesised that the PLAT polymorphism may be correlated with AMD. Therefore, the current study was conducted. Methods: A total of 121 AMD patients and 108 healthy subjects were included in the study. Genotyping was performed by PCR. The strength of the association between AMD and polymorphism was expressed by estimating the odds ratio (OR). Results: There was a significant relationship between the Del/Del genotype and susceptibility to AMD (OR = 2.25, 95 % CI = 1.07-4.69, p = 0.031). After adjusting for various factors such as age, smoking habit and workplace, a similar relationship was obtained (OR = 2.51, 95 % CI = 1.01-6.23, p = 0.049). Conclusions: The homozygosity of the Del allele was found to increase the susceptibility to AMD. This polymorphism may contribute to the risk of AMD in population.

Association of Alu-repeat Polymorphism and Myocardial Infarction in Pakistani Population

Polymorphism of tissue plasminogen activator(t-PA), gene-induced myocardial infarction (MI) is not well-defined in patients suffering from high blood pressure. Plasminogen activator generates the active enzyme by limited proteolysis of zymogen plasminogen to plasmin. Plasmin then degrades the fibrin network of a clot to form soluble product in thrombi. This action of t-PA can be suppressed by plasminogen activator inhibitor type1(PAI-1). This study determined the potential insertion/deletion of polymorphism that may contribute to the development of MI in Pakistani population. The study analyzed blood samples originating from three hundred and fifty patients with MI, two hundred and fifty healthy individuals as controls, and hundred hypertensive study subjects. The genomic DNA was extracted from the blood of each individual, and a Polymerase Chain Reaction was carried out to study polymorphism of Tissue plasminogen Activator (t-PA) gene. The Chi-square method was used to reveal the demographic differences among the groups. Cholesterol's higher levels, triglyceride, LDL-cholesterol, and lower HDL-cholesterol levels had been investigated in cases/patients in contrast with controls. In some cases, the input allele frequency ("I") is higher with MI (p = 0.0354). Diabetes, high blood pressure, family history, and smoking had a strong association with MI (p<0.01). No significant association between myocardial infarction and Insertion/Deletion (I/D) and Deletion/Deletion (D/D) polymorphism of t-PA gene, significant association found between Insertion/Insertion(I/I) and MI, which supports the results of previous MI studies.

Alu-repeat polymorphism in the tissue plasminogen activator (t-PA) gene, seminal t-PA concentration, and male fertility impairment: A case-control study.

BackgroundTissue plasminogen activator (t-PA) is a protein involved in the fibrinolytic system that catalyzes the conversion of plasminogen into the active plasmin. The activity of t-PA is controlled by plasminogen activator inhibitor-1. t-PA has crucial functions during spermatogenesis. One polymorphism was reported for t-PA gene, either the presence of a 300-bp Alu-repeat (Alu ) or its absence (Alu ).Objective The current work aimed at studying the association between Alu polymorphism in the t-PA gene and male infertility.Materials and MethodsUsing polymerase chain reaction on genomic DNA isolated from the blood of 79 participants, a region polymorphic for Alu element insertion in t-PA gene was amplified. In addition, total t-PA concentration, plasminogen activator inhibitor-1 /t-PA complex concentration, and t-PA activity in seminal plasma were measured by enzyme-linked immunosorbent assay.ResultsThe results indicate that the percentage of infertile participants (n = 50) who were homozygous for t-PA Alu insertion (Alu), heterozygous Alu or homozygous for t-PA Alu deletion (Alu) did not change significantly (p = 0.43, 0.81, and 0.85, respectively) when compared with the control participants (n = 29). On the other hand, a significant decrease (p = 0.0001) of t-PA total concentration in seminal plasma was observed in the infertile group in comparison with the control group. However, the results indicate that there is no association between the t-PA Alu different genotypes and the total t-PA seminal concentration in the infertile group when compared to the control group (p = 0.63).ConclusionData obtained from the current study does not support an association between t-PA Alu polymorphism and t-PA seminal concentration or male infertility.

The Role of TPA Gene Polymorphism in the Risk Of Recurrent Venous Thromboembolism in Young Patients

Introduction - Tissue plasminogen activator (TPA) is a protein involved in the breakdown of blood clots. The TPA 311 bp Ins/Del gene polymorphism influences the release of intravascular injection of TPA. However, the role of this polymorphism in pathogenesis of recurrent venous thromboembolism (VTE) remains controversial. Methods - We analyzed 208 young patients under 45 years old (101 men and 107 women, mean age – 37,4 years) with at least one confirmed episode of VTE. The patients were genotyped by PCR and subsequent gel electrophoresis for DNA polymorphism of tissue plasminogen activator gene (TPA, 311 bp Ins/Del). Intergroup differences in the distribution of genotypes were assessed by Fisher's exact method. The “odds ratios” (OR) with 95% confidence intervals (CI) and p-values were determined using the SPSS software version 17,0 (SPSS Inc, Chicago, IL, USA). Results - Recurrent VTE was diagnosed in 105 (50,5%) patients (First group). The comparison group consisted of 103 patients without disease recurrence (Second group). Recurrence of isolated deep-vein thrombosis (DVT) was diagnosed in 68,6% patients (n=72), whereas recurrent thromboembolic events were detected in 31,4% patients (n=33). The frequency of TPA Del/Del genotype was almost 2-fold decreased in patients with recurrent VTE when compared to those with single thrombotic episode (14,3% vs 28,2%, respectively; OR=0,4; 95% CI: 0,2-0,9; p=0,017). For other genotypes of this gene we haven’t found any significant difference between the compared groups (group I vs. group II): TPA Del/Ins - 53,3 % vs. 42,7 % and TPA Ins/Ins - 32,4 % vs. 29,1% (p>0,05). However, we observed significant differences in distribution of TPA genotypes between the patients with recurrence of isolated DVT and those with thromboembolic events. In particular, the frequency of TPA Del/Del genotype was 2,5 times less in the group of patients with recurrence of isolated DVT (9,7% vs. 24,2% in patients with recurrent thromboembolic events; OR=0,3; 95% CI: 0,1-1,0; p=0,049). Conclusion - The presence of TPA Del/Del genotype may have a protective effect against the risk of recurrent VTE episodes. This effect is more evident for patients with isolated DVT. Further studies are needed to confirm these findings.

Alu DNA Polymorphism of Human Tissue Plasminogen Activator (tPA) Gene in Diabetic Jordanian Patients Patients

Background:Hypercoagulability and hypofibrinolysis are among the symptoms exhibited by diabetic patients. Our study aimed to address the polymorphic nature of Alu DNA fragment in the human tissue plasminogen activator gene within diabetes mellitus (DM) Jordanian patients.Methods:Genomic DNA was isolated from 76 DM patients and 60 non-diabetic Jordanian individuals, and the Alu fragment was amplified using PCR. Results:The results showed that 80% of the non-diabetic Jordanian subjects were homozygotes for the deletion of the Alu fragment (Alu-/-), 16.7% were homozygotes for its insertion (Alu+/+), and 3.3% were heterozygotes (Alu+/-). Besides, 36.8% of the diabetic patients exhibited the Alu-/- or Alu+/- genotype, and 26.3% were Alu+/+. The Alu-/- genotype occurred less frequently in the diabetic individuals. Conclusion:The high frequency of the Alu-/- genotype constitutes a protective deletion with respect to DM within the normal subjects.

Effect of Periodontal Surgery on Tissue Plasminogen Activator and Plasminogen Activator Inhibitor Type-1 Gene Expression in Gingival Tissues of Periodontitis Patients: A Controlled Before-And-After Study

Background: Regulation of the plasminogen activation system (PAS) is a vital component in governing proteolytic events within the extracellular matrix (ECM). PAS is believed to play a substantial role in the destruction and healing of periodontal tissues. Thus, the current work aimed to study the histopathological effect of open flap debridement (OFD) on periodontitis, as well as its effect on tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) gene levels in gingival tissues. Methods: A total of 30 subjects were enrolled in the present study. They were divided into two groups: Group I (control group) included 10 periodontally healthy volunteers and group II (periodontitis group) comprised 20 patients suffering from stage III grade B periodontitis. Gingival tissue samples were collected from all periodontitis patients, before and after OFD, and from healthy controls. Hematoxylin and eosin (H&E) stained slides were subsequently examined and gene expression levels of t-PA and PAI-1 were assessed in the gingiva through quantitative reverse transcription polymerase chain reaction (RT-PCR). Results: Gingival tissue samples from periodontitis patients showed widely dilated blood vessels, diffuse hemorrhage, areas of edema, and disorganized collagen fibers together with large amounts of inflammatory cells in between. Following OFD, smaller sized blood vessels, a restored collagen fiber distribution, and an obvious decrease in the inflammatory infiltrate were noted. Gene expression levels of t-PA and PAI-1 were significantly higher in the periodontitis patients compared to the healthy controls. Although their levels showed a significant decrease following OFD in the periodontitis group, they were still significantly higher than the control group. Conclusion: OFD procedures resulted in down regulation of t-PA and PAI-1 expression levels in the gingiva of periodontitis patients, which could signify an important role of these proteins on periodontal disease progression.

The Effect of Methyl Jasmonate and Temperature on the Transient Expression of Recombinant Proteins in Cucurbita pepo L.

The aim of this study is to assess the effect of methyl jasmonate (MeJA) and temperature on the valuable pharmaceuticals expression in a virus-mediated transient expression system, and so the Zuchini Yellow Mosaic Virus (ZYMV) based vector was used for transferring the GFP reporter gene and recombinant tissue plasminogen activator (rtPA) gene (K2S) to cucurbit (Cucurbita pepo L.). MeJA, temperature and time (days after inoculation), were evaluated as a factorial experiment in a completely randomized design (CRD). At first, the effect of all treatment combinations on GFP expression was assessed. At this step, the ELISA test was used to select the optimum treatment combination. ELISA method revealed the significant difference between applied treatments. The optimized treatment significantly increased the expression of rtPA compared to the control. The Real-Time PCR reaction for both GFP and rtPA genes showed no significant differences between optimum and control treatments, however, transcripts of the small subunit of RuBisCO were extremely down-regulated in optimum treatment condition. Reduction in RuBisCO expression at protein level was tangible under treatment condition based on the ELISA test. Therefore, it can be inferred that suppressing the expression of RuBisCO, probably resulted in higher access of expression system to free amino acids inside the cell. In this study, MeJA has been shown to be a positive factor, but the low temperature (17°C), unlike previous studies, suppressed the expression of recombinant protein unexpectedly, probably due to the incompatibility of the viral construct with low temperature. In conclusion, the use of a suitable gene construct, which is not sensitive to temperature, is likely to result in a more favorable outcome.

Deletion of the Alu Repeat in the Tissue Plasminogen Activator (tPA) Gene For Protection of Breast Cancer

Deletion of the Alu Repeat in the Tissue Plasminogen Activator (tPA) Gene For Protection of Breast Cancer

ChAdOx1 and MVA based vaccine candidates against MERS-CoV elicit neutralising antibodies and cellular immune responses in mice

The Middle East respiratory syndrome coronavirus (MERS-CoV) has infected more than 1900 humans, since 2012. The syndrome ranges from asymptomatic and mild cases to severe pneumonia and death. The virus is believed to be circulating in dromedary camels without notable symptoms since the 1980s. Therefore, dromedary camels are considered the only animal source of infection. Neither antiviral drugs nor vaccines are approved for veterinary or medical use despite active research on this area. Here, we developed four vaccine candidates against MERS-CoV based on ChAdOx1 and MVA viral vectors, two candidates per vector. All vaccines contained the full-length spike gene of MERS-CoV; ChAdOx1 MERS vaccines were produced with or without the leader sequence of the human tissue plasminogen activator gene (tPA) where MVA MERS vaccines were produced with tPA, but either the mH5 or F11 promoter driving expression of the spike gene. All vaccine candidates were evaluated in a mouse model in prime only or prime-boost regimens. ChAdOx1 MERS with tPA induced higher neutralising antibodies than ChAdOx1 MERS without tPA. A single dose of ChAdOx1 MERS with tPA elicited cellular immune responses as well as neutralising antibodies that were boosted to a significantly higher level by MVA MERS. The humoral immunogenicity of a single dose of ChAdOx1 MERS with tPA was equivalent to two doses of MVA MERS (also with tPA). MVA MERS with mH5 or F11 promoter induced similar antibody levels; however, F11 promoter enhanced the cellular immunogenicity of MVA MERS to significantly higher magnitudes. In conclusion, our study showed that MERS-CoV vaccine candidates could be optimized by utilising different viral vectors, various genetic designs of the vectors, or different regimens to increase immunogenicity. ChAdOx1 and MVA vectored vaccines have been safely evaluated in camels and humans and these MERS vaccine candidates should now be tested in camels and in clinical trials.

Transient expression of recombinant tissue plasminogen activator (rt-PA) gene in cucurbit plants using viral vector.

To use a transient expression system to express a truncated human tissue plasminogen activator (K2S) gene in cucurbit plants. The recombinant tissue plasminogen activator protein (K2S form) was expressed in active form in cucurbit plants. Its molecular weight was 43kDa. The plant-derived rt-PA was determined using goat anti-rabbit antibody by western blotting. Among the infected lines, the highest expression of rt-PA was 62ng/100mg per leaf tissue as measured by ELISA. The enzymatic activity of the plant-derived rt-PA was 0.8IU/ml. The K25 form of rt-PA was expressed for the first time using the viral expression system. Plant-derived rt-PA showed similar potency to commercially-available PA.

Alu-repeat Polymorphism in the Tissue Plasminogen Activator Gene and Risks of Myocardial Infarction in Tunisian Population

This study aimed to determine whether I/D polymorphism predispose to the development of MI in Tunisia. 50 patients with coronary artery disease complicated by MI and 70 healthy controls were analyzed. Quantitative analyses lipids are founded. DNA was isolated from blood samples. Polymorphisms were assessed by polymerase chain reaction method. Statistical differences between groups were determined by Chi-square test. Compared to controls, cases have significantly higher levels of total cholesterol, triglycerides and LDL-cholesterol and lower level of HDL-cholesterol. There are no significant differences between patients and controls in terms of allelic and genotypic frequencies. However, the frequency of the “I” allele is higher in cases which have 2 MI (p=0.0354). Additionally, a statistically significant association between diabetes, arterial high blood pressure, family history and cigarette smoking with MI was founded (p<0.01). I/D polymorphism of t-PA gene is not associated with MI in this sample of Tunisian population.

The Effects of Glucocorticoids on Trabecular Meshwork and its Role in Glaucoma

Primary Open-Angle Glaucoma (POAG), an optic neuropathy that is a leading cause of irreversible blindness, has been studied extensively in hopes of better understanding its underlying mechanism. Glucocorticoids (GC) are commonly used to treat inflammatory ocular conditions but are also known to increase the risk of glaucoma by raising Intraocular Pressure (IOP) in susceptible individuals, leading to steroid- induced glaucoma. Based on clinical studies as well as molecular experiments, steroid-induced glaucoma and POAG show many similarities, including a common underlying mechanism of IOP elevation. Studying steroid-induced glaucoma can reveal more about the pathways underlying decreased outflow of aqueous humor and POAG. GCs have been shown to cause numerous structural changes in the Trabecular Meshwork (TM), including thickening of trabecular beams, activation of TM cells and increased deposition of extracellular material. GCs also upregulate the expression of MYOC (myocilin) in human TM, a gene whose mutation is linked to 10% of juvenile glaucoma cases. Other studies demonstrate that GCs downregulate PLAT, which codes for tissue Plasminogen Activator (tPA) and decrease Matrix Metalloproteinase (MMP) gene expression. In addition, tPA administration has been shown to prevent GC-induced IOP elevation in sheep eyes. The present review demonstrates some of the important interactions between GCs and the TM that can lead to novel therapeutic measures in the setting of steroid- induced glaucoma as well as POAG.

Histone deacetylase inhibition enhances tissue plasminogen activator release capacity in atherosclerotic man.

The expression of the tissue plasminogen activator (t-PA) gene appears to be under epigenetic control and can be affected by histone deacetylation inhibition. The study aimed to test if histone deacetalyase inhibitor treatment lead to increased t-PA release or reduced exhaustion in t-PA release in response to stimulation, as well as change in plasminogen activator inhibitor-1 (PAI-1) in subjects with coronary disease. In this clinical study, 16 post-myocardial infarction subjects, the perfused forearm model was used with isoprenaline provocation during 20 minutes, to stimulate local t-PA release. Each subject was measured twice on the same day (repeated stimuli sequences) as well as on two different occasions, without treatment and after four weeks of treatment with valproic acid (500 mg, twice daily). Net forearm release for t-PA in response to isoprenaline at minutes 1.5, 3, 6, 9, 12, 15 and 18 was measured, allowing assessment of cumulative t-PA release. There was a reduction in the exhaustion of cumulative t-PA release during repeated and prolonged stimulation with valproic acid treatment compared to non-treatment. Plasma PAI-1 antigen was decreased following treatment compared to non-treatment (18.4 ± 10.0 vs. 11.0 ± 7.1 nanograms/ml respectively, mean with 95% confidence interval). These findings demonstrate that histone deacetylation inhibition increases the capacity for endogenous t-PA release in subjects with vascular disease. Furthermore, the fibrinolytic balance is favored with suppressed PAI-1 levels. More studies are needed to establish the clinical relevance of these findings.Trial registrationEU Clinical Trials Register 2012-004950-27

Relation of PAI-1 and TPA genes polymorphisms to acute myocardial infarction and its outcomes in Egyptian patients.

Endogenous fibrinolysis is a protective mechanism against arterial thrombotic occlusion, which would otherwise lead to permanent tissue damage as acute myocardial infarction (AMI). We aimed to investigate the association of plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (TPA) genes polymorphisms with myocardial infarction and its outcomes in Egyptian patients. 184 patients with AMI and 184 controls were included in the study. PAI-1 and TPA genes polymorphisms were analyzed by polymerase chain reaction. All patients were followed for AMI complications during their hospitalization. We found a significant association among TPA ID, II genotypes, and I allele and increased risk of AMI by 2.1, 3.2, and 1.9 fold, respectively. Also, the frequencies of PAI-1 4G/4G genotype and 4G allele were significantly increased in patients with AMI as compared to the control group. Furthermore, AMI patients with PAI-1 4G/4G genotype were significantly more likely to have morbidity and mortality complications as compared to AMI patients without complications (P = 0.00 and 0.048, respectively). We concluded that 4G/4G genotype and 4G allele of the PAI-1 gene are associated with risk of AMI and its morbidity. The PAI-1 4G/4G genotype is associated with mortality of AMI. There is also an association between TPA ID, II genotypes, and I allele with increased risk of AMI.

Histone Deacetylase Inhibitor Treatment Increases Coronary t-PA Release in a Porcine Ischemia Model

BackgroundThe expression of the tissue plasminogen activator gene can be affected by histone deacetylation inhibition and thus appears to be under epigenetic control.ObjectivesThe study aimed to test if in vivo pharmacological intervention by valproic acid treatment would lead to increase in tissue plasminogen activator release capacity.MethodsIn an anaesthetized pig model, a controlled transient coronary occlusion was used to stimulate coronary tissue plasminogen activator release in a valproic acid treated (one week) and a non-treated group. Coronary venous blood samples from the ischemic region were collected, great cardiac vein thermodilution flow measurements were performed, and trans-coronary tissue plasminogen activator fluxes were calculated. Plasminogen activator inhibitor-1 was also measured.ResultsAdequate sampling from the affected area after the 10 minute ischemic period was confirmed by lactate measurements. Fluxes for tissue plasminogen activator at minutes 1, 3, 5, 7 and 10 were measured and then used to present cumulative net tissue plasminogen activator release for the whole measurement period for both groups. Area under the curve was higher for the valproic acid treated group at 10 minutes; 932±173 nanograms (n = 12) compared to the non-treated group, 451±78 nanograms (n = 10, p = 0.023). There was no difference in levels of plasminogen activator inhibitor-1 between groups.ConclusionsThese findings support a proof of concept for histone deacetylation inhibition positive effect on tissue plasminogen activator expression in an in vivo setting. Further studies are needed to find an optimal way to implement histone deacetylation inhibition to achieve desired clinical changes in tissue plasminogen activator expression.

Expression of the truncated tissue plasminogen activator (K2S) gene in tobacco chloroplast

As because the plant plastid genome is highly polyploid, the transformation of chloroplasts permits the introduction of thousands of copies of foreign genes per plant cell and generates extraordinarily high levels of recombinant protein. Human tissue-type plasminogen activator is one of the most important pharmaceutical proteins involved in the breakdown of blood clots in brain and heart blood vessels. We report the introduction and expression of the truncated human tissue plasminogen activator (K2S) gene in tobacco chloroplasts. The K2S-containing vector pKCZK2S was successfully transferred to tobacco plastomes using the biolistic delivery procedure. Transplastomic plants were selected on RMOP medium containing spectinomycin (500 mg/l). In order to achieve homoplasmy, several rounds of selection and regeneration were performed. The presence, site-specific integration, homoplasmy, expression and activity assay of the transgene were confirmed in the transplastomic plants by PCR, Southern-blot, RT-PCR, SDS-PAGE, ELISA, Dot-blot, Western-blot and zymography analysis. Our results show that the tissue plasminogen activator (K2S form) protein to be expressed in tobacco chloroplasts in active form.

Targeted introduction of tissue plasminogen activator (TPA) at the AAVS1 locus in mesenchymal stem cells (MSCs) and its stable and effective expression

Thrombolytic therapy using tissue plasminogen activator (TPA) is an effective method for treating acute myocardial infarction. However, the systemic administration of TPA is associated with the risk of hemorrhage. Mesenchymal stem cells (MSCs) from bone marrow are characterized by low immunogenicity and homing toward damaged tissues and are therefore ideal cell carriers to achieve lesion-targeting medication. In this article, TPA gene was integrated into the AAVS1 of mesenchymal stem cells, which has been confirmed to be a safe chromosomal locus. The targeting efficiency was 83%. The clones with the site-specific integration retained the stem cell traits of MSCs, displayed a normal karyotype and could persistently and effectively express TPA, as demonstrated by an average expression activity of 1.5units/mL (3.4-fold that of the control group). After subculture and subsequent growth for two weeks, the clones showed an average TPA activity of 1.43units/mL and exhibited no significant differences among the individual clones. In summary, the foreign TPA gene can be specifically introduced to the AAVS1 locus, whereby it can be stably and effectively expressed. MSCs can serve as cell carriers for the targeted treatment of a thrombus using TPA.

Non-Invasive Magnetic Resonance Imaging in Rats for Prediction of the Fate of Grafted Kidneys from Cardiac Death Donors

The main objective of this study was to assess cardiac death (CD) kidney grafts before transplantation to determine whether blood oxygen level-dependent (BOLD) and diffusion MRI techniques can predict damage to these grafts after transplantation. We assessed CD kidney tissue by BOLD and diffusion MRI. We also examined pathological and gene expression changes in CD kidney grafts before and after transplantation. Although there was significantly more red cell congestion (RCC) in the inner stripe of the outer medulla (IS) in both 1 h after cardiac death (CD1h) and CD2h kidneys destined for grafts before transplantation compared with CD0h (p<0.05), CD2h, but not CD1h, kidney grafts had significantly different RCC in the IS 2 days after transplantation (p<0.05). Consistent with these pathological findings, tissue plasminogen activator (tPA) gene expression was increased only in the cortex and medulla of CD2h kidney grafts after transplantation. BOLD MRI successfully and non-invasively imaged and quantified RCC in the IS in both CD1h and CD2h kidney grafts (p<0.05). Diffusion MRI also non-invasively assessed increased the apparent diffusion coefficient in the IS and decreased it in the outer stripe (OS) of CD2h grafts, in concordance with interstitial edema in the IS and tubule cellular edema in the OS. These two types of edema in the outer medulla could explain the prolonged RCC in the IS only of CD2h kidney grafts, creating part of a vicious cycle inhibiting red cells coming out of capillary vessels in the IS. Perfusion with University of Wisconsin solution before MRI measurements did not diminish the difference in tissue damage between CD1h and CD2h kidney grafts. BOLD and diffusion MRI, which are readily available non-invasive tools for evaluating CD kidney grafts tissue damage, can predict prolonged organ damage, and therefore the outcome, of transplanted CD kidney grafts.

The -7351C/T Polymorphism in the TPA Gene and Ischemic Stroke Risk: A Meta-Analysis

BackgroundA number of studies assessed the association of tissue plasminogen activator(TPA) gene polymorphisms with ischemic stroke, but the results were contradictory. We aimed to explore the role of TPA -7351C/T SNP in the susceptibility to ischemic stroke through a meta-analysis.MethodsThe PubMed, MEDLINE, EMBASE, China Biological Medicine Database and WANFANG DATA databases were searched until August 2012. The strict selection criteria and exclusion criteria were determined, and odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Stroke subtype was determined using Trial of Org 10172 in Acute Treatment criteria (TOAST). Statistical analyses were performed using the STATA12.0 software.ResultsA total of 2,299 ischemic stroke cases and 1,948 controls in seven case-control studies were included in the meta-analysis. Significant association between -7351C/T polymorphism in the TPA gene and ischemic stroke was observed in all comparison models (TT+CT versus CC, TT versus CT+CC and T versus C). In the subgroup analysis by ethnicity, TT homozygote carriers had a 142% increased risk of ischemic stroke compared with the C allele carriers among East-Asians (TT versus CT+CC: OR = 2.42, 95% CI = 1.07–5.48), but not in South-Asians and Caucasians, and significantly increased risks were found for T versus C among both East-Asians (OR = 1.33, 95% CI = 1.05–1.68) and Caucasians(OR = 1.16, 95% CI = 1.02–1.31). Further stratification for stroke subtype in three Caucasian studies showed the association between -7351C/T polymorphism and Large-artery atherosclerosis (LAA), but not Small-vessel occlusion (SVO) and Cardioembolism (CE).ConclusionsThis meta-analysis suggested that the -7351C/T polymorphism in TPA gene would be a risk factor for ischemic stroke, especially among East-Asians compared with Caucasians, but not in South-Asians, and it may play a role in the pathogenesis of LAA in Caucasians, but not in SVO and CE.