Gene expression changes of urokinase plasminogen activator and urokinase receptor in rat testes at postnatal stages

Aim： To investigate the gene expression changes of urokinase plasminogen activator （uPA）/urokinase receptor （uPAR） in rat testes at postnatal stages and explore the effects of uPA/uPAR system on the rat spermatogenesis. Methods： The mRNAs of uPA and uPAR in rat testes were measured by using real-time quantitative polymerase chain reaction （PCR） at postnatal days 0, 5, 10, 15, 21, 28, 35, 42, 49 and 56, respectively. Results： The tendencies of uPA and uPAR mRNA expression were similar at most postnatal stages except for Do. The expression of uPAR mRNA in rats testes was relatively higher than that of uPA at postnatal Do, and both were decreased until D21, increased obviously at postnatal D28, reached a peak at postnatal D35, then declined sharply at postnatal D42 and retained at a low level afterwards. Conclusion： The uPA/uPAR system may be strongly linked to spermiation and spermatogenesis via regulating germ cell migration and proliferation, as well as promoting the spermiation and detached residual bodies from the mature spermatids.

Studies on the Relationship between Urokinase Plasminogen Activator(uPA)and Human Sperm Motility

To clarify the role of urokinase plasminogen activator(uPA) in the mechanisms of regulating sperm motility and the ability of fertilizing, we investigated the quantities and activities of uPA in human seminal Plasma and on the membrane of spermatozoa.Semens were harvested from 22 infertile patients with asthenospermia and 20 healthy fertile men according to WHO standards. To quantify the membrane-bound uPA in the samples, polyclonal antibodies against human urokinase were employed by means of a sandwich ELISA. The uPA activities in seminal plasma and on the surface of spermatozoa were determined using Agarose-Fibrine-Plate method and the experiment of immunological identification with polyclonal antibodies against urokinase. In lysates of spermatozoa, significantly lower levels of uPA(23. 1±7.35 mu/106 cells ) and uPA activity (5.13±3.85 mu/106 cells) were found in patient group as compared to healthy fertile men exhibiting normospermia (29. 89±9. 40 mu/105 cells and 10. 17±6. 18 mu/106 cells). In seminal plasma, uPA activity in patient group (2134±1581. 3 IU/L)was also found significantly lower than that of normal group (3365±1859. 5 IU/L). Positive correlations were observed between sperm motility and uPA quantities (r=0. 48, P＜0. 005), as well as with uPA activities (r= 0. 45,P＜0. 005).Thus, it is inferred that membrane associated uPA on human spermatozoa may be related directly to sperm motility and fertility.

Gene expression of fibrinolytic factors urokinase plasminogen activator and plasminogen activator inhibitor-1 in rabbit temporo-mandibular joint cartilage with disc displacement

Background The urokinase plasminogen activator system is believed to play an important role in degradation of the extracellular matrix associated with cartilage and bone destruction; however its precise roles in temporomandibular disorders have not yet been clarified. The aims of this study were to investigate the gene expression of fibrinolytic factors urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in the articular cartilage of rabbit temporomandibular joint (TMJ) with disc displacement (DD) and to probe the relationship between fibrinolytic activity and cartilage remodeling. Methods Disc displacement of right joints was performed in 36 of 78 rabbits under investigation. The animals were sacrificed at 4 days and 1, 2, 4, 8 and 12 weeks after surgery, respectively. The right joints of these animals were harvested and processed for the examination of mRNA expression of uPA and PAI-1 in articular cartilage using in situ hybridization techniques. Results The expression of uPA and PAI-1 was co-expressed weakly in the chondrocytes from transitive zone to hypertrophic zone and mineralized zone, while no hybridizing signals were shown in proliferative zone and superficial zone in control rabbits. The most striking was the up-regulation of uPA and PAI-1 mRNA in 4-day rabbits postoperatively at the onset of cartilage degeneration. The strongest hybridizing signals for uPA and PAI-1 were seen in 2-week rabbits postoperatively. After 2 weeks, the expression of uPA and PAI-1 began to decrease and reached nearly normal level at 12 weeks. Conclusions The expression of the uPA/PAI-1 system coincides with the pathological changes in condylar cartilage after DD. The uPA/PAI-1 system may be one of the essential mediators in articular cartilage remodeling.

Genetic association of urokinase-type plasminogen activator gene rs2227564 site polymorphism with sporadic Alzheimer's disease in the Han Chinese population

A missense C/T polymorphism in exon 6 （the NCBI rslD is rs2227564） of the urokinase-type plasminogen activator gene has been identified as a possible hot spot for Alzheimer＇s disease risk. The present study analyzed urokinase-type plasminogen gene polymorphisms of rs2227564 with sporadic Alzheimer＇s disease by PCR-restriction fragment length polymorphism. Results showed that CC, CT and TT genotype distribution frequencies had significant differences between sporadic Aizheimer＇s disease patients and healthy controls, in-depth analysis of the association between urokinase-type plasminogen gene rs2227564 polymorphisms and sporadic Alzheimer＇s disease indicated that people with the C-positive genotype CC ＋ CT were at a higher risk for developing sporadic Alzheimer＇s disease. These results support the contribution of the polymorphisms of rs2227564 in the urokinase-type plasminogen gene to the pathogenesis of sporadicAIzheimer＇s disease in the Han Chinese population.

Cloning and Analysis of the Promoter Region of Rat uPA Gene

Objective To clone and analyze the promoter sequence of rat urokinase plasminogen activator protein gene. Methods The genomic DNA was extracted from rat testicular tissue. According to urokinase plasminogen activator, the gene sense primer and antisense primer of uPA gene were designed and synthesized, then Touch-Down PCR were performed. After proper purification, the PCR product was sequenced, analyzed with the promoter prediction software and compared with the DNA sequence of rattuas urokinase plasminogen activator. Results The cloned uPA gene was about 1 572 bp in length, which contained a full open-reading frame with 21 bp in length exons, and the upper region of transcriptional start was 1 551 bp in length which was eucaryon transcriptional control area. The 5＇ UTR had a promoter region including a non-responsive TATA-box. Not only the GC-box binding region was found in this gene, but also active protein I （AP1） and SP1 were seen in other regions. Conclusion A 1 572 bp uPA gene fragment （GenBank accession No.X65651） was obtained from rat genomic DNA library, containing eucaryon transcriptional control area with a promoter region, non-conspicuous TATA-box, GC-box and an extron. A non-responsive TATA-box is located at the upper -30 region.

Bioactive proteins in healthy pregnancies and preeclampsia： relevance to hypertension and proteinuria

Background Bioactive proteins, such as cytokines and chemokines, have not been systematically evaluated in healthy and preeclamptic pregnancies. We aimed to investigate the difference of these proteins between healthy and preeclamptic pregnancies in order to help clarify their potential roles in the pathogenesis of hypertension and proteinuria in preeclampsia. Methods Samples of amniotic fluid and maternal/umbilical cord blood were collected from normal pregnancies and women with preeclampsia for examination of bioactive proteins. Fifty-three pregnant women were enrolled in this study. Of them, 30 pregnant women were recruited as healthy controls, and 23 pregnant women were diagnosed with preeclampsia. An antibody array was used to screen for higher levels of cytokines and related proteins in amniotic fluid than in the blood samples, and these proteins were then selected for quantification by immunoassay. Results Interleukin-1 receptor 4, hepatocyte growth factor, and urokinase plasminogen activator receptor were significantly elevated in the blood of preec^ampsia patients. In particular, intedeukin-1 receptor 4 was 8-fold higher in preeclampsia patients than in the healthy pregnancies. Moreover, in cord blood samples hepatocyte growth factor and interleukin-8 were significantly higher in preeclampsia patients. Conclusions Because of the biologic activities, Interleukin-1 receptor 4, hepatocyte growth factor, urokinase plasminogen activator receptor and interleukin-8 in maternal and/or cord blood could play a role in the pathogenesis of hypertension and proteinuria in preeclampsia.