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Abstract Background Fibroblast-like synoviocytes (FLS) play a prominent role in rheumatoid synovitis and degradation of the extracellular matrix through the production of inflammatory cytokines and metalloproteinases (MMPs). Since animal models are frequently used for elucidating the disease mechanism and therapeutic development, it is relevant to study the ultrastructural characteristics and functional responses in human and mouse FLS. The objective of the study was to analyze ultrastructural characteristics, Interleukin-6 (IL-6) and Metalloproteinase-3 (MMP-3) production and the activation of intracellular pathways in Fibroblast like synoviocytes (FLS) cultures obtained from patients with rheumatoid arthritis (RA) and from mice with collagen-induced arthritis (CIA). Methods FLSs were obtained from RA patients (RA-FLSs) (n = 8) and mice with CIA (CIA-FLSs) (n = 4). Morphology was assessed by transmission and scanning electron microscopy. IL-6 and MMP-3 production was measured by ELISA, and activation of intracellular signaling pathways (NF-κB and MAPK: p-ERK1/2, p-P38 and p-JNK) was measured by Western blotting in cultures of RA-FLSs and CIA-FLSs stimulated with tumor necrosis factor-alpha (TNF-α) and IL-1β. Results RA-FLS and CIA-FLS cultures exhibited rich cytoplasm, rough endoplasmic reticula and prominent and well- developed Golgi complexes. Transmission electron microscopy demonstrated the presence of lamellar bodies, which are cytoplasmic structures related to surfactant production, in FLSs from both sources. Increased levels of pinocytosis and numbers of pinocytotic vesicles were observed in RA-FLSs (p < 0.05). Basal production of MMP-3 and IL-6 was present in RA-FLSs and CIA-FLSs. Regarding the production of MMP-3 and IL-6 and the activation of signaling pathways, the present study demonstrated a lower response to IL-1β by CIA-FLSs than by RA-FLSs. Conclusion This study provides a comprehensive understanding of the biology of RA-FLS and CIA-FLS. The differences and similarities in ultrastructural morphology and important inflammatory cytokines shown, contribute to future in vitro studies using RA-FLS and CIA-FLS, in addition, they indicate that the adoption of CIA-FLS for studies should take careful and be well designed, since they do not completely resemble human diseases.
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Recent studies have found that the mechanistic target of rapamycin (mTOR) signaling pathway affects the growth and development of hair follicles, and is closely related to hair growth cycle. This review summarizes the effect of mTOR signaling pathway on the hair growth cycle, and provides new ideas for the treatment of hair diseases.
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Arsenic, as a metal element, has metallic and non-metallic properties and is widely distributed in nature. In the list of carcinogens of the International Agency for Research on Cancer, arsenic is clearly listed as the first class of carcinogens. Chronic arsenic poisoning caused by arsenic contamination of drinking water is a major health problem facing human beings worldwide. This kind of pollution occurs naturally due to geological structure, and the most serious one can lead to cancer, among which skin cancer is the most specific. In addition, epidemiological studies have shown that long-term arsenic exposure can also lead to bladder cancer, lung cancer, and liver cancer, etc. However, there have been a number of different views on the potential mechanisms of arsenic carcinogenesis. Carcinogenesis through signal transduction pathway is one of the important molecular mechanisms, including Wnt, mitogen-activated protein kinase (MAPK), phosphatidylinositol 3 kinase-protein kinase B-mammalian target of rapamycin (PI3K/AKT/mTOR), nuclear factor kappa-B (NF-κB) and transforming growth factor-β (TGF-β). When there is a problem in the upstream and downstream or one of its links in the signal transduction pathway, the proliferation and differentiation of human cells are out of control, which can lead to cancer.
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The Notch signaling pathway plays an important role in cell fate and homeostasis.Various studies have proved that the Notch signaling pathway has strong effects on corneal wound healing and the maintenance of corneal homeostasis.Limbal stem cells inhibit differentiation and proliferation by inhibiting the Notch signaling pathway.Physiologic downregulation promotes cell migration and wound coverage in the early stage of corneal epithelial repair, and physiologic upregulation in the late stage of corneal epithelial repair is related to preventing excessive stratification of corneal epithelial cells and maintaining cell differentiation.Fibrosis is correlated with Notch after corneal stromal injury.The Notch signaling pathway is directly involved in the endothelial-to-mesenchymal transition induced by transforming growth factor-β after corneal endothelial injury.In addition, there are interactions between the Notch signaling pathway and 14-3-3 sigma, epidermal growth factor receptor, Sirt6, microRNA, and matrix metalloproteinases in maintaining corneal epithelial homeostasis, corneal epithelial differentiation, corneal stromal excessive inflammatory response, corneal neovascularization, etc.This review summarizes the function of the Notch signaling pathway in corneal wound healing.
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The Notch signaling pathway plays an important role in cell fate and homeostasis.Various studies have proved that the Notch signaling pathway has strong effects on corneal wound healing and the maintenance of corneal homeostasis.Limbal stem cells inhibit differentiation and proliferation by inhibiting the Notch signaling pathway.Physiologic downregulation promotes cell migration and wound coverage in the early stage of corneal epithelial repair,and physiologic upregulation in the late stage of corneal epithelial repair is related to preventing excessive stratification of corneal epithelial cells and maintaining cell differentiation.Fibrosis is correlated with Notch after corneal stromal injury.The Notch signaling pathway is directly involved in the endothelial-to-mesenchymal transition induced by transforming growth factor-β after corneal endothelial injury.In addition,there are interactions between the Notch signaling pathway and 14-3-3 sigma,epidermal growth factor receptor,Sirt6,microRNA,and matrix metalloproteinases in maintaining corneal epithelial homeostasis,corneal epithelial differentiation,corneal stromal excessive inflammatory response,corneal neovascularization,etc.This review summarizes the function of the Notch signaling pathway in corneal wound healing.
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Objective To investigate the effects of ferulic acid (FA) and adipose-derived mesenchymal stem cells(ADMSCs)on rat hepatic stellate cells (HSCs) by regulating TGF-β/smad signal transduction pathway.Methods HSCs were divided into 4 groups:blank control group,FA control group,ADMSCs control group and FA+ADMSCs group.The apoptosis rate of HSCs in each group was detected by flow cytometry.The expression levels of TGF-β1,Smad2,Smad3 and Smad7 mRNA in HSCs were detected by qRT-PCR.The TGF-β1 and Smad7 protein levels,and phosphorylated-Smad2/3 (p-Smad2/3)expression were detected by Western blot.Results Compared with the other 3 groups,the apoptosis rate of HSCs in the FA+ADMSCs group was significantly increased(P＜0.05),while the expression levels of TGF-β1,Smad2 and Smad3 mRNA were significantly decreased,and the Smad7 mRNA expression was increased;moreover,the expression levels of TGF-β1 protein and p-Smad2/3 were significantly decreased,while the Smad7 protein expression was significantly increased(P＜0.05).Conclusion FA can enhance the effect of ADMSCs for down-regulating the TGF-β1 expression in HSCs,and then leads to the decrease of downstream p-Smad2/3 activity and Smad7 expression increase,thus participates in promoting cellular apoptosis.
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Objective To analyze the effects of bone morphogenetic protein 7 (BMP 7) on insulin signaling pathway in mice and its involved molecular mechanisms. Methods To increase BMP7 expression in liver, adenovirus bearing BMP7 was injected into mice via tail vein. The impact of BMP7 overexpression on glucose metabolism was assayed by glucose tolerance test and insulin tolerance test. The levels of proteins involved in insulin signaling pathway and c-Jun N-terminal kinase ( JNK) signaling pathway were analyzed by Western blot. Results The blood glucose level was increased by BMP7 overexpression (P>0. 05), while the glucose tolerance and insulin tolerance were decreased by BMP7. The p-Akt and p-GSK3βin liver and epididymal white adipose tissue (WAT) were reduced in the BMP7-overexpressed mice (P>0. 01), indicating insulin signal transduction was inhibited. In gastrocnemius muscle, the insulin signal transduction was not altered by BMP7. Mechanistically, the JNK pathway was activated by BMP7 in liver and epididymal WAT (P>0. 01), while the JNK pathway in skeletal muscle was not changed. Conclusions In mice, BMP7 elevated blood sugar and decreased glucose and insulin tolerance. BMP7 inhibited the insulin signaling pathway in liver and WAT. These inhibitory effects on insulin signaling pathway was likely to be achieved by an activating JNK signaling pathway.
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Thromboxane A2 receptors (TPs) widely distribute in different organ systems and localize both on cell membranes and in intracellular structures.TPs are the members of seven-transmembrane G-protein-coupled receptor (GPCR) super family.Historical-ly, the involvement of TPs in platelet functions has received the greatest attention .TPs have the capacity to activate different signaling cascades which regulate platelet shape change , aggregation and secretion response .Currently , anti-platelet drugs primarily act on re-ceptors and /or signaling molecules in activation pathways .The signaling transduction of TPs in platelet contributes to the investigation of the effects of extracts of traditional Chinese medicine on antiplatelet aggregation and the exploration of the action mechanisms .
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Cross-talk of intracellular signaling pathways that share common components (hubs) is organized in form of a bow-tie network topology.Signaling cross-talk is functionally pleiotropic for target genes regulation, resulting in functional redundancy, synergism and antagonism, which should be precisely controlled to prevent signaling 'leaking' or 'spillover'.Thus, the biological system has evolved multiple insulating mechanisms to achieve stimulus-specific response that maintains intracellular homeostasis.The insulation mechanism of signaling cross-talk suggests: (1) the functional duality of cross-talk molecules that determine cell fate requires selectively targeting dysregulated cross-talk molecules while protecting the normal ones from off-target or unintended effects, and we propose them as the targetable cross-talk molecules;(2) cross-talk molecules are usually carried on the macromolecular complex as their functional platforms, thus the structural plasticity of conformational changes at the interaction surface of cross-talk molecules asks for intensive work on the relationship study between drug binding and biological activity, which we propose as the accessible cross-talk molecules.Therefore, signaling cross-talk and its insulation mechanism play instructive leading roles in resolving the bottlenecks of current drug R&D and improve the clinical outcome.
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Cells in the body are exposed to physiological and pathophysiological stimuli that encompass both chemical and mechanical factors. It is important to understand how these factors modulate functions at cellular and organ levels. Compared to the large amount of information on cellular or organ responses to chemical factors, there is a paucity of knowledge on the effects of mechanical factors. Recent advances of fluorescence proteins and microscopy make it a very useful tool for elucidating the mechanotransduction processes; the state-of-the-art technologies for live-cell imaging of signaling is particularly valuable for investigating the spatial and temporal aspects of molecular mechanisms in mechanobiology. This review will cover the basic knowledge of fluorescence proteins and their application for biological research. In particular, the development and characterization of biosensors based on fluorescent resonance energy transfer (FRET) will be discussed. Genetically encoded FRET biosensors, which allows the imaging and quantification of tempo-spatial activation of molecules, will be introduced to demonstrate how the initiation and transmission of biochemical signals in response to local mechanical stimulation can be visualized in live cells. Specific emphasis will be on the elucidation of molecule hierarchy of signaling transduction in live cells upon the mechanical stimulation.
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Objective:To investigate the role of epidermal growth factor receptor (EGFR)in the regulation of B[a]P-induced silent information regulator 1 (SIRT1 ) activation in the human bronchial epithelial cells (BEAS-2B),and to clarify the relationship between EGFR/SIRT1 signal transduction pathway and the occurrence and development lung cancer.Methods:The prediction analysis of transcriptional factor binding sites of SIRT1 was performed by MOTIF SearchTM software.The primary cultivated BEAS-2B cells were divided into control group (without B[a]P exposure)and B[a]P groups (the cells were exposed to B[a]P for 6,12,24,48 h).RT-PCR and Western blotting method were carried out to detect the EGFR mRNA and protein expression levels.The BEAS-2B cells transfected with SIRT1 promotor luciferase reporter gene plasmid were treated with human epidermal growth factor (hEGF)and Genistein (tyrosine protein kinase inhibitor)for 24 h,the morphology of BEAS-2B cells was observed by inverted microscope, and luciferase reporter assay was used to test the SIRT1 transcriptional activity.The human lung tissue biopsies were acquired and the immunohistochemical analysis was used to determine the EGFR protein expression level.Results:The transcriptional factor binding sites of SIRT1 contained EGF, 2Fe-2S and vWF.Compared with control group,the expression levels of EGFR mRNA in B [a]P groups were increased in a time-dependent manner,and reached the peak at 12 h (P < 0.05);the EGFR protein expression levels were also increased (P <0.05).The SIRT1 luciferase activity in hEGF group was increased compared with control group (P <0.05);when hEGF and B[a]P worked together,the SIRT1 luciferase activity was increased even further (P <0.001). The cells showed arrangement and morphologic changes gradually when the B[a]P concentration was above 30 μmol · L-1. Genistein (30 μmol · L-1 )inhibited the increase of SIRT1 luciferase activity induced by B [a]P ,and there was significant difference compared with control group (P <0.05).The immunohistochemistry results showed that EGFR expression level in lung cancer tissue was higher than that in normal lung tissue (P < 0.001).Conclusion:EGFR can regulate the B [a]P-induced SIRT1 expression in BEAS-2B cells,and to cause lung chronic inflammation;EGFR/SIRT1 signal transduction pathway may play a role in the occurrence and development of lung cancer.
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Objective: To explore the role of angiotensin receptor type I (AT1)-calcineurin (CaN) signaling pathway in transient outward potassium ion channel (Ito) remolding in hypertrophic atrial myocytes of neonatal rats. Methods: 1 day old neonatal rats’ atrial myocytes were isolated and the cells were divided into 4 groups:①Control group, normal cells were cultured for 24 h,②Stretching group, the cells were cultured for 24 h with mechanical stretching to induce hypertrophy,③Telmisartan group, the cells were treated by telmisartan at 1 μmol/L for 1 h, then cultured for 24 h and ④Cyclosporin-A (CsA) group, the cells were treated by CsA at 0.25 μg/ml for 1 h, then cultured for 24 h. The ratios of protein/DNA in myocytes were compared between Control group and Stretching group, cell hypertrophy was deifned by mRNA expression of atrial natriuretic peptide (ANP). Ito changes were detected by whole-cell patch clamping technique, proteins expressions of Kv4.3 and CaN A subunit were examined by Western blot analysis. Results: Compared with Control group, Stretching group showed obviously decreased Ito density and Kv4.3 protein expression, while increased CaN A protein expression; Compared with Stretching group, the above effects were reduced in Telmisartan group and CsA group. Conclusion: AT1-CaN signaling pathway was involved in the regulation of Ito channel remodeling in hypertrophic atrial myocytes of neonatal rats.
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Aim: Rubiaceae is one of the largest families of plants and it includes the Jamaican genus Portlandia. This family has been used in several ethnomedicinal practices. Thus, in this study we investigated whether extracts of two species of Portlandia affect In vitro proliferation of breast cancer cells. Study Design: Metastatic (MDA-MB-231 and HeLa) cells were incubated in the absence or in the presence of Portlandia extracts. A human non-metastatic (MCF-10A) and normal (ATCC PCS-600-010) epithelial cell lines were used as control. Methodology: At the end of the study all cell lines were incubated with Portlandia extracts (-and its subfractions-) and then analyzed on proliferation, thymidine incorporation and mitogenic and survival signaling pathways on metastatic and non-metastatic cells. Results: It was found that Portlandia methanol extract inhibited proliferation of MDA-MB- 231 in a dose-dependent manner attenuating the phosphorylation of Erk1/2 and Akt1 without affecting the proliferation of MCF-10A cells. [3H] thymidine incorporation was also decreased by Portlandia methanol extract. This study suggests that Portlandia extracts selectively affected the proliferation of metastatic breast cancer cells through the modulation of Erk1/2 and Akt1 activities that play a critical role during cell survival and proliferation. Conclusion: Portlandia leaf extracts contain active compounds, which strongly repress cancer cell proliferation in a dose-dependent manner and selectively down-regulate phosphorylation of both Erk1/2 and Akt1 activities.
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Objective To observe the effects of Qishu granule on PI3K/Akt signaling transduction pathways in the process of hepatic fibrosis, and further explain the anti-hepatic fibrosis mechanism of Qishu granule.Methods Wistar rats were randomly divided into normal group, model group, experimental control group and Qishu granule group. Liver fibrosis was duplicated in rats by intraperitoneal injection of CCl4, and the rats were given appropriate treatment at the same day. Rats in Qishu granule group were given a gavage 2 g/(kg?d), 1.0 mL/100 g, while rats in experimental control group and normal group were given the same amount of aquae sterilisata. Rats in each group were taken liver tissue samples in the 1st, 2nd and 4th week, and were checked for the protein expression levels of p-Akt (Ser473), p-Akt (Thr308), Bad (Ser136) and Caspase9 by Western blot.Results Compared with the model group, expression levels of p-Akt (Ser473), p-Akt (Thr308), Bad (Ser136) and Caspase9 in model and Qishu granule groups increased in every time points (P0.05).Conclusion Qishu granule could regulate PI3K/Akt signaling transduction pathways, and inhibit the occurrence and development of liver fibrosis.
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As one of members of the Notch gene family , Notch-1 signaling pathway plays an important role in the processing of cell proliferation , differentiation , survival and apoptosis .The abnormal expression of Notch-1 is closely related to tumorigenesis and de-velopment .In recent years , many studies have focused on the relationship between the Notch-1 signaling pathway and tumor .This arti-cle reviews the achievement of Notch-1 signaling pathway in recent tumor researches .
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Objective Using an adenoviral vector , the wild-type PTEN gene was transduced into activated hepatic stellate cell (HSC) in vitro and the phosphorylation status of Akt were investigated. Methods The wild type PTEN gene was transduced into activated HSC in vitro mediated by adenoviral vector. The expressions of PTEN and total Akt in HSC were measured by Western blot and Real-time fluorescent quantitation PCR. And the expressions of phosphorylated Akt (Thr308) in HSC was determined by Western blot. Results The data showed that exogenous wild type PTEN gene was successfully transduced and expressed in activated HSC in vitro. The over-expression of wild type PTEN resulted in the significant down-regulated expression of phosphorylated Akt (Thr308) in activated HSC (P 0.50). Conclusions The overexpression of wild-type PTEN can negatively regulate PI3K/Akt signaling transduction by inhibiting the phosphorylation of Akt in activated HSC in vitro.
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BACKGROUND: Calcium calmodulin-dependent kinase Ⅱ (CaMKⅡ) can be more active in patients with left ventricular hypertrophy (LVH), which in turn causes phosphorylation of ryanodine receptors, resulting in inactivation and the instability of intracellular calcium homeostasis. The present study aimed to determine the effect of CaMKⅡ–ryanodine receptor pathway signaling in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia. METHODS: Forty New Zealand rabbits were randomized into four groups (10 per group): sham group, LVH group, KN-93 group (LVH+KN-93), and ryanodine group (LVH+ryanodine). Rabbits in the LVH, KN-93, and ryanodine groups were used to establish a left ventricular hypertrophy model by the coarctation of the abdominal aorta, while those in the sham group did not undergo the coarctation. After eight weeks, action potentials (APs) were recorded simultaneously in the endocardium and epicardium, and a transmural electrocardiogram (ECG) was also recorded in the rabbit left ventricular wedge model. Drugs were administered to the animals in the KN-93 and ryanodine groups, and the frequency of triggered APs and ventricular tachycardia was recorded after the rabbits were given isoprenaline (1 mol/L) and high-frequency stimulation. RESULTS: The frequency (animals/group) of triggered APs was 0/10 in the sham group, 10/10 in the LVH group, 4/10 in the KN-93 group, and 1/10 in the ryanodine group. The frequencies of ventricular tachycardia were 0/10, 9/10, 3/10, and 1/10, respectively. The frequencies of polymorphic ventricular tachycardia or ventricular fibrillation were 0/10, 7/10, 2/10, and 1/10, respectively. The frequencies of triggered ventricular arrhythmias in the KN-93 and ryanodine groups were much lower than those in the LVH group (P<0.05). CONCLUSIONS: KN-93 and ryanodine can effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH. The CaMKⅡ–ryanodine signaling pathway can be used as a new means of treating ventricular arrhythmia.
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Objective To explore the effects of sumatriptan on the modulation of calcitonin generelated peptide(CGRP) expression and its involving intracellular signaling transduction mechanisms in rat trigeminal ganglion(TG) after organ culture.Methods Using organ culture in vitro model,54 isolated TGs of SD rats were randomly divided into fresh group ( n =6 ),control group ( n =6 ) and experimental group (n =42,6 TGs for each subgroup).Experimental group included seven subgroups,which were respectively pretreated with four different concentrations of sumatriptan,specific inhibitors of extracellular signalregulated kinases 1/2 (ERK1/2) pathway (U0126 and PD98059 ),and the inhibitor of c-Jun N-terminal kinase (JNK) (SP600125).After co-cultured with above intervention agents for 24 h,CGRP-immunoreactivity (CGRP-ir) positive neurons and CGRP-mRNA expression levels were quantified by immunohistoehemistry stain and real-time polymerase chain reaction,respectively.Phosphorylated ERK1/2 (pERK1/2) and JNK (pJNK) proteins levels were determined by Western-blotting method.Results The CGRP-ir ( + ) neurons expression levels were significantly increased after 24 h organ culture.However,0.10 and 0.50 mg/ml concentrations of sumatriptan remarkably decreased the CGRP-ir ( + ) neurons expression levels.The positive cell percentage,positive optic area,integrated optical density,mean optical density and CGRP-mRNA expression level in TG were significantly reduced than control groups (tPCP =8.652,26.382; tarea =6.220,13.917; tIA =5.606,15.904; tM14 =2.661,21.748; tmRNA =8.032,15.675.P ＜ 0.05 ).The CGRP-mRNA expressions were significantly down-regulated after co-incubation with concentration of 0.50 mg/ml sumatriptan for 24 h in TG of SD rat ( P ＜0.05 ).The levels of pERK1/2 and pJNK protein kinase detected by Western-blotting were significantly reduced by 0.50 mg/ml concentration of sumatriptan,the degrees of which were closed to the ERK1/2 and JNK pathway specific blockers.Conclusion It suggests that the optimal concentration of sumatriptan significantly down-regulates CGRP over-expression via intracellular ERK1/2 and JNK signaling transduction pathways in TG after organ culture.
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Objective To investigate whether Tumor Necrosis Factor-alpha (TNFα) is capable of activating Rho kinase pathway which leads to smooth muscle cell proliferation and the intervention function of Rosuvastatin, and clarify the mechanism and intervention manner of anti-atherosclerosis by Rosuvastatin. Methods Wistar neonate rat smooth muscle cells were cultured, and the activity of cell proliferation was determined by methyl thiazolyl tetrazolium (MTT). The expression of Rho kinase genes after the stimulation of TNFα was evaluated by RT-PCR. Western blot method was used to measure the protein expression of proliferating cell nuclear antigen (PCNA) after TNFα stimulation and Rosuvastatin intervention in smooth muscle cell. Results The TNFα stimulation significantly enhanced the expression of Rho kinase and increased the expression of PCNA protein in smooth muscle cells (P < 0.05). These effects were positively correlated with prolonged treatment whereas additional Rosuvastatin administration inhibited the above-mentioned effects (P < 0.05). Conclusions The activation of TNFα mediated Rho kinase signaling pathway can significantly promote smooth muscle cell proliferation, and Rosuvastatin can not only inhibit this pathway but also the induced proliferation.
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Objective To explore the effects and mechanisms of urokinase-type plasminogen activator (uPA) on high glucose-induced rat mesangial cells proliferation and phenotype transformation. Methods Rat mesangial cells were cultured and incubated in media containing either 5 mmol/L D-glucose or 30 mmol/L D-glucose with or without addition of wortmannin, or uPA (105 U/L) for different time periods. At the end of the incubation period, mesangial cells proliferation was assessed by MTT assay and flow cytometric analysis. Cyclin-dependent kinase 2 (CDK2) and p27kip1 expression and activation of Akt were evaluated by Western blotting and Akt kinase assay respectively. Furthermore, the expression and distribution of α-SMA were detected with laser confocal microscopy. Results MTT assay and flow cytometric analysis demonstrated that high glucose induced mesangial cells proliferation (P＜0.05) and an incresed proportion of cells in G2/M+S stage after 24 h incubation (P＜0.01), which were attenuated by uPA or wortmannin (P＜0.01). High glucose induced the enhance of Akt activity after 3 h (P＜0.05), and the effect was inhibited by wortmannin or uPA (P＜0.01). High glucose did not alter CDK2 expression (P＞0.05),but significantly inhibited p27kip1 expression (P＜0.05), which was attenuated by wortmannin or uPA (P＜0.01). High glucose induced the up-regulation of α-SMA expression and perinucleus location in mesangial cells after 24 h (P＜0.01), which were alleviated by wortmannin or uPA (P＜0.01). Conclusion uPA up-regulates p27kip1 expression and counteracts high glucose-induced mesangial cells proliferation and phenotype transformation via blocking PI3K-Akt signaling pathway.