BACKGROUND Although transmembrane protein 106C(TMEM106C)has been elucidated to be overexpressed in cancers,its underlying mechanisms have not yet been fully understood.AIM To investigate the expression levels and mole...BACKGROUND Although transmembrane protein 106C(TMEM106C)has been elucidated to be overexpressed in cancers,its underlying mechanisms have not yet been fully understood.AIM To investigate the expression levels and molecular mechanisms of TMEM106C across 34 different cancer types,including liver hepatocellular carcinoma(LIHC).METHODS We analyzed TMEM106C expression patterns in pan-cancers using microenvironment cell populations counter to evaluate its association with the tumor microenvironment.Gene set enrichment analysis was conducted to identify molecular pathways related to TMEM106C.Chromatin immunoprecipitation followed by sequencing(ChIP-seq)analysis was conducted to identify upstream transcriptional regulators of TMEM106C.In LIHC,we examined mRNA profiles,performed in-house quantitative polymerase chain reaction,immunohistochemistry,and constructed a co-expression gene network.Functional assays,including cell counting kit-8,cell cycle,apoptosis,migration,and invasion,were conducted.The effect of nitidine chloride(NC)on LIHC xenograft was evaluated through RNA sequencing and molecular docking.Finally,potential therapeutic agents targeting TMEM106C were predicted.RESULTS TMEM106C was significantly overexpressed in 27 different cancer types and presaged poor prognosis in four of these types,including LIHC.Across pan-cancers,TMEM106C was inversely correlated to the abundances of immune and stromal cells.Furthermore,TMEM106C was significantly linked to cell cycle and DNA replication pathways in pan-cancers.ChIP-seq analysis predicted CCCTC-binding factor as a pivotal transcriptional factor targeting the TMEM106C gene in pan-cancers.Integrated analysis showed that TMEM106C was upregulated in 4657 LIHC compared with 3652 normal liver tissue[combined standardized mean difference=1.31(1.09,1.52)].Inhouse LIHC samples verified the expression status of TMEM106C.Higher TMEM106C expression signified worse survival conditions in LIHC patients treated with sorafenib,a tyrosine kinase inhibitor(TKI).Co-expressed analysis revealed that TMEM106C were significantly enriched in the cell cycle pathway.Knockout experiments demonstrated that TMEM106C plays a crucial role in LIHC cell proliferation,migration,and invasion,with cell cycle arrest occurring at the DNA synthesis phase,and increased apoptosis.Notably,TMEM106C upregulation was attenuated by NC treatment.Finally,TMEM106C expression levels were significantly correlated with the drug sensitivity of anti-hepatocellular carcinoma agents,including JNJ-42756493,a TKI agent.CONCLUSION Overexpressed TMEM106C was predicted as an oncogene in pan-cancers,which may serve as a promising therapeutic target for various cancers,including LIHC.Targeting TMEM106C could potentially offer a novel direction in overcoming TKI resistance specifically in LIHC.Future research directions include in-depth experimental validation and exploration of TMEM106C’s role in other cancer types.展开更多
The transjugular intrahepatic portosystemic stent-shunt (TIPS) has successfully been used in the management of refractory variceal bleeding and ascites in patients with portal hypertension. Major drawbacks are the ind...The transjugular intrahepatic portosystemic stent-shunt (TIPS) has successfully been used in the management of refractory variceal bleeding and ascites in patients with portal hypertension. Major drawbacks are the induction of hepatic encephalopathy and shunt dysfunction. We present a 59-year-old woman with alcoholic liver cirrhosis who received a TIPS because of recurrent bleeding from esophageal varices. Stent occlusion occurred 4 mo after placement of the TIPS. Laboratory testing revealed resistance to activated protein C (APC). Combination therapy with low-dose enoxaparin and clopidogrel could not prevent her recurrent stent occlusion. Finally, therapy with high-dose enoxaparin was sufficient to prevent further shunt complications up to now (follow-up period of 1 year). In conclusion, early occlusion of a TIPS warrants testing for thrombophilia. If risk factors are confirmed,anticoagulation should be intensified. There are currently no evidence-based recommendations regarding the best available anticoagulant therapy and surveillance protocol for patients with TIPS.展开更多
Protein C(PC)is a key component of the vitamin K-dependent coagulation pathway.It exerts anticoagulant effects by inactivating factors V and VIII.Acquired or inherited PC deficiency results in a prothrombotic state,wi...Protein C(PC)is a key component of the vitamin K-dependent coagulation pathway.It exerts anticoagulant effects by inactivating factors V and VIII.Acquired or inherited PC deficiency results in a prothrombotic state,with presentations varying from asymptomatic to venous thromboembolism.However,there has been an increasing number of reports linking PC deficiency to arterial thromboembolic events,such as myocardial infarction and ischemic stroke.This editorial focuses on the association between PC deficiency and thromboembolism,which may provide some insights for treatment strategy and scientific research.展开更多
Primary Budd-Chiari syndrome (BCS) is a spontaneously fatal disease characterized by an obstruction of the hepatic venous outflow tract due to thrombosis or a primary disease of the venous wall. The primary form of BC...Primary Budd-Chiari syndrome (BCS) is a spontaneously fatal disease characterized by an obstruction of the hepatic venous outflow tract due to thrombosis or a primary disease of the venous wall. The primary form of BCS is extremely rare. This is a disease mainly affecting young adults of both sexes. Clinical manifestations are variable;they can be asymptomatic, acute, or subacute but mostly chronic. Several causes have been identified, such as myeloproliferative syndrome, antiphospholipid syndrome, paroxysmal nocturnal hemoglobinuria, and inherited thrombotic disorders. Data on primary BCS in Sub-Saharan Africa is rare as most publications available are case reports. In these reports, the causes are unknown with poor prognosis in most cases often leading to patient death. We herein present a case report of a male patient diagnosed with a primary BCS at Yaoundé General Hospital (Cameroon) caused by a Protein C deficiency who presented with ascites decompensating liver cirrhosis. Treatment was based on anticoagulants, diuretics and laxatives administration. Two years after the diagnosis, the patient is alive with clinical and paraclinical improvement.展开更多
Background: Preeclampsia is reported to complicate 2% - 8% of pregnancies globally and is an important cause of maternal and perinatal morbidity and mortality. The aetiology and pathogenesis are still poorly understoo...Background: Preeclampsia is reported to complicate 2% - 8% of pregnancies globally and is an important cause of maternal and perinatal morbidity and mortality. The aetiology and pathogenesis are still poorly understood and substantial improvement has not been made in the prediction, prevention and treatment of the disease. Objective: To compare the frequency of activated protein C resistance (APC-R) in patients with pre-eclampsia to that of normotensive pregnant women and to determine the correlation between activated protein ratio (APC-ratio) and the severity of pre-eclampsia. Methodology: A cross-sectional study was carried out in 100 pre-eclamptic patients and 100 normotensive pregnant controls. The APC-ratio was determined using the modified activated partial thromboplastin time. Study participants with APC-ratio of less than 2.0 were defined as having APC-R. Data was analyzed using SPSS version 22.0. Results: Mean APC-ratio was significantly lower in pre-eclamptics (2.89 ± 1.70) compared to normotensive pregnant women (3.57 ± 1.06) (p = 0.0008) and the levels were also higher in mild (2.95 ± 1.15) compared to severe pre-eclamptics (2.62 ± 1.14). The frequency of APC-R was 26% among women with pre-eclampsia compared to 4% among normotensive controls (p = 0.000). Among 100 pre-eclamptic women 7 (21.2%) out of 33 with mild pre–eclampsia had APC-R, while 19 (28.4%) out of 67 with severe pre-eclampsia had APC-R. APC-ratio had a significant negative correlation with mean arterial blood pressure (r = −0.324;p = 0.000) and proteinuria (r = −0.379;p = 0.000) among study participants. Conclusion: The frequency of activated protein c resistance is significantly higher in pre-eclamptics compared to normotensive pregnant women and this is more pronounced in those with severe pre-eclampsia compared with those with mild disease. APC-R may therefore be used as a marker of severity in the disease.展开更多
BACKGROUND Systemic lupus erythematosus(SLE)is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum.Patients with protein C(PC)and protein S(PS)deficiency are prone to t...BACKGROUND Systemic lupus erythematosus(SLE)is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum.Patients with protein C(PC)and protein S(PS)deficiency are prone to thrombosis.In contrast,patients with primary hyperfibrino-lysis tend to bleed.CASE SUMMARY A 52-year-old female patient with bilateral pleural effusion was diagnosed with"tuberculous pleurisy"and treated with anti-tuberculosis drugs and prednisone.The coagulation-related laboratory results showed decreased fibrinogen,PC activity,PS activity,and antithrombinШactivity.The immune-related laboratory results showed positive antinuclear antibody,anti-Smith antibody,anticardiolipin antibody(ACL),anti-β2-glycoprotein I antibody(aβ2GPI)and direct Coomb’s test and decreased complement 3 and complement 4.Thoracoscopy was performed and bloody pleural fluid was drained.Pathology of the pleural biopsy showed lymphocytes,plasma cells,and a few eosinophils in adipose and fibrous connective tissue.Results of whole exome sequencing of blood showed no genetic mutations suggesting the presence of hereditary hematological diseases.The patient was finally diagnosed with SLE and primary hyperfibrinolysis,and was treated with prednisolone,hydroxychloroquine,and compound cyclophosphamide.CONCLUSION PC and PS deficiency in SLE might be related to ACL and aβ2GPI.SLE and primary hyperfibrinolysis can coexist in one patient,with both a risk of thrombosis and a risk of bleeding.展开更多
Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cereb...Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.展开更多
Studies on structure-activity relationship of phenothiazines (PTZs) forinhibition of protein kinase C (PKC) and reversal of multidrug resistance (MDR) has been made invitro. The results showed that the order of potenc...Studies on structure-activity relationship of phenothiazines (PTZs) forinhibition of protein kinase C (PKC) and reversal of multidrug resistance (MDR) has been made invitro. The results showed that the order of potency of reversal effect of PTZs on MDR is as follows:2-COC_3 H_7 > 2-CF_3 > 2-COCH_3 > H. The type of piperazinyl substitution also significantlyaffected potency against MDR. The results show the order: CH_3 > COOC_2 H_5 > C_2 H_4 OH. Inaddition, PKC plays a marked role in diverse cellular process including MDR. Some derivatives of PTZwas tested for inhibition of PKC, of which PTZ11 showed the highest inhibitory effect of MDR andPKC, implying a potential reversal agent of MDR for tumor therapy in the future. We also tried toexplore the possible binding model of PTZs to PKC. Our molecular-modeling study preliminarilysuggests how these PTZs bind to PKC and provides a structural basis for the design of high affinityPKC-modulator. The infor-mation may be used in the rational design of more effective drugs.展开更多
Inflammation and coagulation constantly influence each other and are constantly in balance.Emerging evidence supports this statement in acute inflammatory diseases,such as sepsis,but it also seems to be very important...Inflammation and coagulation constantly influence each other and are constantly in balance.Emerging evidence supports this statement in acute inflammatory diseases,such as sepsis,but it also seems to be very important in chronic inflammatory settings,such as inflammatory bowel disease(IBD).Patients with Crohn's disease and ulcerative colitis have an increased risk of thromboembolic events,and several abnormalities concerning coagulation components occur in the endothelial cells of intestinal vessels,where most severe inflammatory abnormalities occur.The aims of this review are to update and classify the type of coagulation system abnormalities in IBD,and analyze the strict and delicate balance between coagulation and inflammation at the mucosal level.Recent studies on possible therapeutic applications arising from investigations on coagulation abnormalities associated with IBD pathogenesis will also be briefly presented and critically reviewed.展开更多
AIM: To investigate the effects of hyperlipidemia on acute pancreatitis (AP) and the possible mechanisms. METHODS: Rat models of hyperlipidemia and AP were established by Triton WR1339 and cerulein respectively. H...AIM: To investigate the effects of hyperlipidemia on acute pancreatitis (AP) and the possible mechanisms. METHODS: Rat models of hyperlipidemia and AP were established by Triton WR1339 and cerulein respectively. Human albumin was used to treat AP complicated by hyperlipidemia. In each group, we compared the histological score, volume of ascites, ratio of pancreatic wet/dry weight, serum amylase (AMY) and pancreatic acinar cell apoptosis. The level of protein kinase C (PKC) membrane translocation in pancreatic tissue was detected by Western blot.RESULTS: In the hyperlipidemia model established by Triton WR1339, triglyceride (TG) increased remarkably and reached its peak 6 h after injection, and most rats developed mild acute pancreatitis. Histological score, volume of ascites, ratio of wet/dry weight and serum AMY in AP animals with hyperlipidemia were obviously higher than those in AP animals (P 〈 0.05) and decreased after albumin therapy but not significantly (P 〉 0.05). Apoptotic cells detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) increased in AP animals with hyperlipidemia and did not change distinctly after albumin therapy. PKC membrane translocation level increased in AP animals with hyperlipidemia and decreased remarkably after albumin therapy (P 〈 0.05).CONCLUSION: Hyperlipidemia may induce AP or intensify pancreatic injury. Albumin therapy can not alleviate pancreatic lesion effectively. PKC activation may be one mechanism by which AP is intensified by hyperlipidemia.展开更多
The full-length c DNA of functionally-unknown salivary protein C002 in Schizaphis graminum was cloned using rapid amplification of c DNA ends(RACE) and designated as Sg C002(Gen Bank accession no. KC977563). It is...The full-length c DNA of functionally-unknown salivary protein C002 in Schizaphis graminum was cloned using rapid amplification of c DNA ends(RACE) and designated as Sg C002(Gen Bank accession no. KC977563). It is 767 bp long and encodes a protein of 190 amino acid residues with a predicted mass of 21.5 k Da and a predicted cleavage site of N-terminal signal peptide between the 24 th and the 25 th residues. Sg C002 is specifically expressed in salivary gland with the highest level at the 2nd instar. Introducing Sg C002-specific 476-si RNA, but not 546-si RNA to aphids through artificial diet significantly suppressed Sg C002 expression. Silencing Sg C002 gene led to lethality of the aphid on wheat plants, but not on pure artificial diet. Our study demonstrated that artificial diet-mediated RNAi can be a useful tool for research on the roles of genes in aphid salivary gland, and also provided new insights into the characteristics of C002 in wheat aphids.展开更多
The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phy- toestrogen derived from radix astragali that binds to estrogen receptors to produc...The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phy- toestrogen derived from radix astragali that binds to estrogen receptors to produce estrogen-like effects. Radix astragali Calycosin has been shown to relieve cognitive impairment induced by diabetes mellitus, suggesting calycosin may improve the cognitive function of Alzhei- mer's disease patients. The protein kinase C pathway is upstream of the mitogen-activated protein kinase pathway and exerts a neuropro- tective effect by regulating Alzheimer's disease-related beta amyloid degradation. We hypothesized that calycosin improves the cognitive function of a transgenic mouse model of Alzheimer's disease by activating the protein kinase C pathway. Various doses of calycosin (10, 20 and 40 mg/kg) were intraperitoneally injected into APP/PS1 transgenic mice that model Alzheimer's disease. Calycosin diminished hippocampal beta amyloid, Tau protein, interleukin-lbeta, tumor necrosis factor-alpha, acetylcholinesterase and malondialdehyde levels in a dose-dependent manner, and increased acetylcholine and glutathione activities. The administration of a protein kinase C inhibitor, cal- phostin C, abolished the neuroprotective effects of calycosin including improving cognitive ability, and anti-oxidative and anti-inflammato- ry effects. Our data demonstrated that calycosin mitigated oxidative stress and inflammatory responses in the hippocampus of Alzheimer's disease model mice by activating the protein kinase C pathway, and thereby improving cognitive function.展开更多
Summary: Activated protein C (APC), a natural anticoagulant, has been reported to exert direct vascu- loprotective, neural protective, anti-inflammatory, and proneurogenic activities in the central nervous system. ...Summary: Activated protein C (APC), a natural anticoagulant, has been reported to exert direct vascu- loprotective, neural protective, anti-inflammatory, and proneurogenic activities in the central nervous system. This study was aimed to explore the neuroprotective effects and potential mechanisms of APC on the neurovascular unit of neonatal rats with intrauterine infection-induced white matter injury. In- traperitoneal injection of 300 ~tg/kg lipopolysaccharide (LPS) was administered consecutively to preg- nant Sprague-Dawley rats at embryonic days 19 and 20 to establish the rat model of intrauterine infec- tion-induced white matter injury. Control rats were injected with an equivalent amount of sterile saline on the same time. APC at the dosage of 0.2 mg/kg was intraperitoneally injected to neonatal rats imme- diately after birth. Brain tissues were collected at postnatal day 7 and stained with hematoxylin and eo- sin (H&E). Immunohistochemistry was used to evaluate myelin basic protein (MBP) expression in the periventricular white matter region. Blood-brain barrier (BBB) permeability and brain water content ~were measured using Evens Blue dye and wet/dry weight method. Double immunofluorescence staining and real-time quantitative PCR were performed to detect microglial activation and the expression of protease activated receptor 1 (PAR1). Typical pathological changes of white matter injury were ob- served in rat brains exposed to LPS, and MBP expression in the periventricular region was significantly decreased. BBB was disrupted and the brain water content was increased. Microglia were largely acti- vated and the mRNA and protein levels of PAR1 were elevated. APC administration ameliorated the pathological lesions of the white matter and increased MBP expression. BBB permeability and brain water content were reduced. Microglia activation was inhibited and the PAR1 mRNA and protein ex- pression levels were both down-regulated. Our results suggested that APC exerted neuroprotective ef- fects on multiple components of the neurovascular unit in neonatal rats with intrauterine infec- tion-induced white matter injury, and the underlying mechanisms might involve decreased expression of PAR1.展开更多
The potential role of the protein kinase C (PKC) transduction systemin controlling proliferation of human pituitary somatotrophinomas was investigat-ed. Twenty somatotrophinomas were studied using PCR and diract seque...The potential role of the protein kinase C (PKC) transduction systemin controlling proliferation of human pituitary somatotrophinomas was investigat-ed. Twenty somatotrophinomas were studied using PCR and diract sequencing methods. No point mutation within the QPKC gene, previously thought to be as-sociated with invasive pituitary tumors, was found in any of the 20 somatotrophi-nomas. It is concluded that PKC trareduction system may play an important rolein controlling pituitary somatotrophinoma proliferation, but there is no correlation between invasiveness and the previously reported QPKC gene mutation.展开更多
This study examined the effect of GHRP-6, a known GHSs receptor agonist, on the phosphorylation of cAMP-responsive element-binding protein (CREB) and the tmderly mechanism. GH3 cells were cultured and subjected to d...This study examined the effect of GHRP-6, a known GHSs receptor agonist, on the phosphorylation of cAMP-responsive element-binding protein (CREB) and the tmderly mechanism. GH3 cells were cultured and subjected to different treatments as follows: GHRP-6, GHRP-6 plus GHRH, phorbol ester (PMA), an activator of PKC, alone or in combination with GHRP-6, G66983, a general inhibitor of PKCs, in the presence or absence of GHRP-6, rottlerin, an inhibitor of PKCs, alone or plus GHRP-6. The cells were transiently transfected with PKCσ-specific siRNA and then treated with GHRP-6. GH level was measured by enzyme-linked immunosorbent assay (ELISA). The expression of phosphor-CREB, PKCσ, PKC0 and phosphor-PKCo was determined by Western blotting. The results showed that GHRP-6 stimulated GH secretion in both time- and dose-dependent manners and enhanced the effect of GHRH on GH secretion. GHRP-6 was also found to induce CREB phosphorylation. Moreover, GH secretion was enhanced by the PKC activator PMA and reduced by the PKC inhibitors (G66983, rottlerin) and knockdown of PKCσ. PKCσ could be activated by GHRP-6. It is concluded that PKC, especialiy PKCσ, mediates CREB phosphorylation and GHRP-6-induced GH secretion.展开更多
BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ...BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ex-pression of protein kinase C (PKC) and their effects on he-patic metastasis of colorectal cancer.METHODS: High performance liquid chromatography wasused to detect contents of cell membrane phospholipids:phosphatidylinosital (PI), phosphatidylserine (PS), phos-phatidylethanolamine (PE) and phosphatidylcholine (PC)in primary foci, paratumor mucosa and hepatic metastaticfoci in patients with colorectal carcinoma. The mRNA ex-pression levels of PKC-α, -δ, -ε, -λ, -ξ isoenzymeswere detected with the QRT-PCR technique.RESULTS: The levels of PI, PC and PE in primary foci andhepatic metastatic foci were higher than those in paratumormucosa. The level of PE in hepatic metastatic foci wasmuch higher than that in primary foci (t =98.88, P <0.01);but the levels of PI and PC were not significantly differentbetween primary foci and hepatic metastatic foci (t =1.73 ,1.36, P>0.05). The expression levels of -δ, -ε,-λ, -ξ were enhanced in primary foci and hepatic metasta-tic foci, but the level of PKC-α in primary foci was de-creased as compared with that in paratumor mucosa. Thelevels of PKC-δ, -ε, -λ, -ξ in hepatic metastatic foci werehigher than those in primary foci. A positive correlationwas observed between the expression levels of PI, PC andand also between those of PE and PKC-δ, -ε, -λ,-ξ. However, there was a close negative correlation be-tween PE and PKC-α.CONCLUSION: Increased levels of PI and PC and de-creased ratio of PKC-α to are related to colorectalcancer genesis. Increased levels of PE, increased expressionof PKC-δ, -ε, -λ, -ξ isoenzymes and decreased level ofPKC-α are related to hepatic metastasis in colorectal carci-noma.展开更多
AIM:To study the protein C activation system in human liver myofibroblasts,and the effects of activated protein C(APC)on these cells.METHODS:Human liver myofibroblasts were obtained by outgrowth.Expression of protease...AIM:To study the protein C activation system in human liver myofibroblasts,and the effects of activated protein C(APC)on these cells.METHODS:Human liver myofibroblasts were obtained by outgrowth.Expression of protease activated receptor 1(PAR-1),endothelial protein C receptor(EPCR) and thrombomodulin(TM)was analyzed by flow cytometry.Extracellular signal-regulated kinase(ERK)1/2 activation was assessed by Western blotting using anti-phospho-ERK antibodies.Collagen synthesis was studied with real-time reverse transcription-polymerase chain reaction(RT-PCR).Activation of protein C was studied by incubating liver myofibroblasts with zymogen protein C in the presence of thrombin and detecting the generation of APC with a colorimetric assay using a peptide substrate. RESULTS:Primary cultures of human liver myofibroblasts expressed EPCR on their surface,together with PAR-1 and TM.This receptor system was functional since exposure of myofibroblasts to APC inducedERK1/2 phosphorylation in a dose-and time-dependent manner.Furthermore,APC significantly upregulated the expression of collagen mRNA,as shown by real-time RT-PCR.Collagen upregulation was controlled through the ERK pathway as it was inhibited when using the mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor PD98059.Finally,using a cell-based colorimetric assay,we showed that intact myofibroblasts converted protein C into APC in the presence of thrombin.CONCLUSION:These data suggest that APC is a new modulator of liver myofibroblast activity and contributes to the pathophysiology of chronic liver diseases.展开更多
AIM: To identify whether Aspergillus fumigatus(A.fumigatus) hyphae antigens induced the release of interleukin-8(IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells(HCECs) and determine the...AIM: To identify whether Aspergillus fumigatus(A.fumigatus) hyphae antigens induced the release of interleukin-8(IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells(HCECs) and determine the involvement of intracellular signalling pathways. METHODS: HCECs were treated with A. fumigatus hyphae antigens with different concentrations and time.The cytoplasmic calcium of HCECs were assessed by fluorescence imaging. Western blot was used to detect the expression of Ca2 +-dependent protein kinase C(PKC). The IL-8 levels were determined by specific human IL-8 enzyme-linked immunosorbent assay(ELISA) and reverse transcriptase polymerase chain reaction(RT-PCR). Using a series of pharmacological inhibitors, we examined the upstream signalling pathway responsible for IL-8 expression in response to A.fumigatus hyphae antigens. RESULTS: Cells exposed to A. fumigatus hyphae antigens showed higher level of IL-8 m RNA expression and protein production. We demonstrated here that stimulation of HCECs with A. fumigatus hyphae triggers an intracellular Ca2 +flux and results in the activation of Ca2 +-dependent PKC(α, βⅠ and βⅡ) which can be attenuated by pre-treatment of cells with laminarin,suggesting that Dectin-1 signals pathway induced cytoplasmic calcium and influence the activation of PKC in HCECs. Inhibitors of Ca2 +-dependent PKC(Ro-31-8220 and Go6976) significantly abolished hyphae-induced expression of IL-8.CONCLUSION: Our findings suggest that A. fumigatushyphae-induced IL-8 expression was regulated by the activation of Dectin-1-mediated Ca2 +-dependent PKC in HCECs.展开更多
基金Supported by the National Natural Science Foundation of China,No.NSFC82160762,No.NSFC82460783Natural Science Foundation of Guangxi,No.2022GXNSFBA035657Innovation Project of Guangxi Graduate Education,No.JGY2023068,No.YCSW2023220.
文摘BACKGROUND Although transmembrane protein 106C(TMEM106C)has been elucidated to be overexpressed in cancers,its underlying mechanisms have not yet been fully understood.AIM To investigate the expression levels and molecular mechanisms of TMEM106C across 34 different cancer types,including liver hepatocellular carcinoma(LIHC).METHODS We analyzed TMEM106C expression patterns in pan-cancers using microenvironment cell populations counter to evaluate its association with the tumor microenvironment.Gene set enrichment analysis was conducted to identify molecular pathways related to TMEM106C.Chromatin immunoprecipitation followed by sequencing(ChIP-seq)analysis was conducted to identify upstream transcriptional regulators of TMEM106C.In LIHC,we examined mRNA profiles,performed in-house quantitative polymerase chain reaction,immunohistochemistry,and constructed a co-expression gene network.Functional assays,including cell counting kit-8,cell cycle,apoptosis,migration,and invasion,were conducted.The effect of nitidine chloride(NC)on LIHC xenograft was evaluated through RNA sequencing and molecular docking.Finally,potential therapeutic agents targeting TMEM106C were predicted.RESULTS TMEM106C was significantly overexpressed in 27 different cancer types and presaged poor prognosis in four of these types,including LIHC.Across pan-cancers,TMEM106C was inversely correlated to the abundances of immune and stromal cells.Furthermore,TMEM106C was significantly linked to cell cycle and DNA replication pathways in pan-cancers.ChIP-seq analysis predicted CCCTC-binding factor as a pivotal transcriptional factor targeting the TMEM106C gene in pan-cancers.Integrated analysis showed that TMEM106C was upregulated in 4657 LIHC compared with 3652 normal liver tissue[combined standardized mean difference=1.31(1.09,1.52)].Inhouse LIHC samples verified the expression status of TMEM106C.Higher TMEM106C expression signified worse survival conditions in LIHC patients treated with sorafenib,a tyrosine kinase inhibitor(TKI).Co-expressed analysis revealed that TMEM106C were significantly enriched in the cell cycle pathway.Knockout experiments demonstrated that TMEM106C plays a crucial role in LIHC cell proliferation,migration,and invasion,with cell cycle arrest occurring at the DNA synthesis phase,and increased apoptosis.Notably,TMEM106C upregulation was attenuated by NC treatment.Finally,TMEM106C expression levels were significantly correlated with the drug sensitivity of anti-hepatocellular carcinoma agents,including JNJ-42756493,a TKI agent.CONCLUSION Overexpressed TMEM106C was predicted as an oncogene in pan-cancers,which may serve as a promising therapeutic target for various cancers,including LIHC.Targeting TMEM106C could potentially offer a novel direction in overcoming TKI resistance specifically in LIHC.Future research directions include in-depth experimental validation and exploration of TMEM106C’s role in other cancer types.
文摘The transjugular intrahepatic portosystemic stent-shunt (TIPS) has successfully been used in the management of refractory variceal bleeding and ascites in patients with portal hypertension. Major drawbacks are the induction of hepatic encephalopathy and shunt dysfunction. We present a 59-year-old woman with alcoholic liver cirrhosis who received a TIPS because of recurrent bleeding from esophageal varices. Stent occlusion occurred 4 mo after placement of the TIPS. Laboratory testing revealed resistance to activated protein C (APC). Combination therapy with low-dose enoxaparin and clopidogrel could not prevent her recurrent stent occlusion. Finally, therapy with high-dose enoxaparin was sufficient to prevent further shunt complications up to now (follow-up period of 1 year). In conclusion, early occlusion of a TIPS warrants testing for thrombophilia. If risk factors are confirmed,anticoagulation should be intensified. There are currently no evidence-based recommendations regarding the best available anticoagulant therapy and surveillance protocol for patients with TIPS.
文摘Protein C(PC)is a key component of the vitamin K-dependent coagulation pathway.It exerts anticoagulant effects by inactivating factors V and VIII.Acquired or inherited PC deficiency results in a prothrombotic state,with presentations varying from asymptomatic to venous thromboembolism.However,there has been an increasing number of reports linking PC deficiency to arterial thromboembolic events,such as myocardial infarction and ischemic stroke.This editorial focuses on the association between PC deficiency and thromboembolism,which may provide some insights for treatment strategy and scientific research.
文摘Primary Budd-Chiari syndrome (BCS) is a spontaneously fatal disease characterized by an obstruction of the hepatic venous outflow tract due to thrombosis or a primary disease of the venous wall. The primary form of BCS is extremely rare. This is a disease mainly affecting young adults of both sexes. Clinical manifestations are variable;they can be asymptomatic, acute, or subacute but mostly chronic. Several causes have been identified, such as myeloproliferative syndrome, antiphospholipid syndrome, paroxysmal nocturnal hemoglobinuria, and inherited thrombotic disorders. Data on primary BCS in Sub-Saharan Africa is rare as most publications available are case reports. In these reports, the causes are unknown with poor prognosis in most cases often leading to patient death. We herein present a case report of a male patient diagnosed with a primary BCS at Yaoundé General Hospital (Cameroon) caused by a Protein C deficiency who presented with ascites decompensating liver cirrhosis. Treatment was based on anticoagulants, diuretics and laxatives administration. Two years after the diagnosis, the patient is alive with clinical and paraclinical improvement.
文摘Background: Preeclampsia is reported to complicate 2% - 8% of pregnancies globally and is an important cause of maternal and perinatal morbidity and mortality. The aetiology and pathogenesis are still poorly understood and substantial improvement has not been made in the prediction, prevention and treatment of the disease. Objective: To compare the frequency of activated protein C resistance (APC-R) in patients with pre-eclampsia to that of normotensive pregnant women and to determine the correlation between activated protein ratio (APC-ratio) and the severity of pre-eclampsia. Methodology: A cross-sectional study was carried out in 100 pre-eclamptic patients and 100 normotensive pregnant controls. The APC-ratio was determined using the modified activated partial thromboplastin time. Study participants with APC-ratio of less than 2.0 were defined as having APC-R. Data was analyzed using SPSS version 22.0. Results: Mean APC-ratio was significantly lower in pre-eclamptics (2.89 ± 1.70) compared to normotensive pregnant women (3.57 ± 1.06) (p = 0.0008) and the levels were also higher in mild (2.95 ± 1.15) compared to severe pre-eclamptics (2.62 ± 1.14). The frequency of APC-R was 26% among women with pre-eclampsia compared to 4% among normotensive controls (p = 0.000). Among 100 pre-eclamptic women 7 (21.2%) out of 33 with mild pre–eclampsia had APC-R, while 19 (28.4%) out of 67 with severe pre-eclampsia had APC-R. APC-ratio had a significant negative correlation with mean arterial blood pressure (r = −0.324;p = 0.000) and proteinuria (r = −0.379;p = 0.000) among study participants. Conclusion: The frequency of activated protein c resistance is significantly higher in pre-eclamptics compared to normotensive pregnant women and this is more pronounced in those with severe pre-eclampsia compared with those with mild disease. APC-R may therefore be used as a marker of severity in the disease.
文摘BACKGROUND Systemic lupus erythematosus(SLE)is an autoimmune disease characterized by systemic involvement and multiple autoantibodies in the serum.Patients with protein C(PC)and protein S(PS)deficiency are prone to thrombosis.In contrast,patients with primary hyperfibrino-lysis tend to bleed.CASE SUMMARY A 52-year-old female patient with bilateral pleural effusion was diagnosed with"tuberculous pleurisy"and treated with anti-tuberculosis drugs and prednisone.The coagulation-related laboratory results showed decreased fibrinogen,PC activity,PS activity,and antithrombinШactivity.The immune-related laboratory results showed positive antinuclear antibody,anti-Smith antibody,anticardiolipin antibody(ACL),anti-β2-glycoprotein I antibody(aβ2GPI)and direct Coomb’s test and decreased complement 3 and complement 4.Thoracoscopy was performed and bloody pleural fluid was drained.Pathology of the pleural biopsy showed lymphocytes,plasma cells,and a few eosinophils in adipose and fibrous connective tissue.Results of whole exome sequencing of blood showed no genetic mutations suggesting the presence of hereditary hematological diseases.The patient was finally diagnosed with SLE and primary hyperfibrinolysis,and was treated with prednisolone,hydroxychloroquine,and compound cyclophosphamide.CONCLUSION PC and PS deficiency in SLE might be related to ACL and aβ2GPI.SLE and primary hyperfibrinolysis can coexist in one patient,with both a risk of thrombosis and a risk of bleeding.
基金supported by the National Natural Science Foundation of China,Nos.82260245(to YX),81660207(to YX),81960253(to YL),82160268(to YL),U1812403(to ZG)Science and Technology Projects of Guizhou Province,Nos.[2019]1440(to YX),[2020]1Z067(to WH)+1 种基金Cultivation Foundation of Guizhou Medical University,No.[20NSP069](to YX)Excellent Young Talents Plan of Guizhou Medical University,No.(2022)101(to WH)。
文摘Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.
文摘Studies on structure-activity relationship of phenothiazines (PTZs) forinhibition of protein kinase C (PKC) and reversal of multidrug resistance (MDR) has been made invitro. The results showed that the order of potency of reversal effect of PTZs on MDR is as follows:2-COC_3 H_7 > 2-CF_3 > 2-COCH_3 > H. The type of piperazinyl substitution also significantlyaffected potency against MDR. The results show the order: CH_3 > COOC_2 H_5 > C_2 H_4 OH. Inaddition, PKC plays a marked role in diverse cellular process including MDR. Some derivatives of PTZwas tested for inhibition of PKC, of which PTZ11 showed the highest inhibitory effect of MDR andPKC, implying a potential reversal agent of MDR for tumor therapy in the future. We also tried toexplore the possible binding model of PTZs to PKC. Our molecular-modeling study preliminarilysuggests how these PTZs bind to PKC and provides a structural basis for the design of high affinityPKC-modulator. The infor-mation may be used in the rational design of more effective drugs.
基金Supported by Italian Ministry of University,No. PRIN-2007Catholic University School of Medicine,No. Linea D1-2009
文摘Inflammation and coagulation constantly influence each other and are constantly in balance.Emerging evidence supports this statement in acute inflammatory diseases,such as sepsis,but it also seems to be very important in chronic inflammatory settings,such as inflammatory bowel disease(IBD).Patients with Crohn's disease and ulcerative colitis have an increased risk of thromboembolic events,and several abnormalities concerning coagulation components occur in the endothelial cells of intestinal vessels,where most severe inflammatory abnormalities occur.The aims of this review are to update and classify the type of coagulation system abnormalities in IBD,and analyze the strict and delicate balance between coagulation and inflammation at the mucosal level.Recent studies on possible therapeutic applications arising from investigations on coagulation abnormalities associated with IBD pathogenesis will also be briefly presented and critically reviewed.
基金Supported by the Key Program of Beijing Academy of Health, No. 1998-11-2001-09
文摘AIM: To investigate the effects of hyperlipidemia on acute pancreatitis (AP) and the possible mechanisms. METHODS: Rat models of hyperlipidemia and AP were established by Triton WR1339 and cerulein respectively. Human albumin was used to treat AP complicated by hyperlipidemia. In each group, we compared the histological score, volume of ascites, ratio of pancreatic wet/dry weight, serum amylase (AMY) and pancreatic acinar cell apoptosis. The level of protein kinase C (PKC) membrane translocation in pancreatic tissue was detected by Western blot.RESULTS: In the hyperlipidemia model established by Triton WR1339, triglyceride (TG) increased remarkably and reached its peak 6 h after injection, and most rats developed mild acute pancreatitis. Histological score, volume of ascites, ratio of wet/dry weight and serum AMY in AP animals with hyperlipidemia were obviously higher than those in AP animals (P 〈 0.05) and decreased after albumin therapy but not significantly (P 〉 0.05). Apoptotic cells detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) increased in AP animals with hyperlipidemia and did not change distinctly after albumin therapy. PKC membrane translocation level increased in AP animals with hyperlipidemia and decreased remarkably after albumin therapy (P 〈 0.05).CONCLUSION: Hyperlipidemia may induce AP or intensify pancreatic injury. Albumin therapy can not alleviate pancreatic lesion effectively. PKC activation may be one mechanism by which AP is intensified by hyperlipidemia.
基金supported by the National Natural Science Foundation of China (30971920,31371946)the International Cooperation Project between China and Belgium (2010DFA32810)the Earmarked Fund for Modern Agro-Industry Technology Research System,China (CARS3)
文摘The full-length c DNA of functionally-unknown salivary protein C002 in Schizaphis graminum was cloned using rapid amplification of c DNA ends(RACE) and designated as Sg C002(Gen Bank accession no. KC977563). It is 767 bp long and encodes a protein of 190 amino acid residues with a predicted mass of 21.5 k Da and a predicted cleavage site of N-terminal signal peptide between the 24 th and the 25 th residues. Sg C002 is specifically expressed in salivary gland with the highest level at the 2nd instar. Introducing Sg C002-specific 476-si RNA, but not 546-si RNA to aphids through artificial diet significantly suppressed Sg C002 expression. Silencing Sg C002 gene led to lethality of the aphid on wheat plants, but not on pure artificial diet. Our study demonstrated that artificial diet-mediated RNAi can be a useful tool for research on the roles of genes in aphid salivary gland, and also provided new insights into the characteristics of C002 in wheat aphids.
基金supported by the a grant from China Postdoctoral Science Project,No.801161020425the Natural Science Foundation of China,No.8160010172
文摘The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phy- toestrogen derived from radix astragali that binds to estrogen receptors to produce estrogen-like effects. Radix astragali Calycosin has been shown to relieve cognitive impairment induced by diabetes mellitus, suggesting calycosin may improve the cognitive function of Alzhei- mer's disease patients. The protein kinase C pathway is upstream of the mitogen-activated protein kinase pathway and exerts a neuropro- tective effect by regulating Alzheimer's disease-related beta amyloid degradation. We hypothesized that calycosin improves the cognitive function of a transgenic mouse model of Alzheimer's disease by activating the protein kinase C pathway. Various doses of calycosin (10, 20 and 40 mg/kg) were intraperitoneally injected into APP/PS1 transgenic mice that model Alzheimer's disease. Calycosin diminished hippocampal beta amyloid, Tau protein, interleukin-lbeta, tumor necrosis factor-alpha, acetylcholinesterase and malondialdehyde levels in a dose-dependent manner, and increased acetylcholine and glutathione activities. The administration of a protein kinase C inhibitor, cal- phostin C, abolished the neuroprotective effects of calycosin including improving cognitive ability, and anti-oxidative and anti-inflammato- ry effects. Our data demonstrated that calycosin mitigated oxidative stress and inflammatory responses in the hippocampus of Alzheimer's disease model mice by activating the protein kinase C pathway, and thereby improving cognitive function.
基金supported by grants from National Natural Science Foundation of China(No.81471519 and No.81401277)the Program for Changjiang Scholars and Innovative Research Team in University of China(No.IRT_14R20)
文摘Summary: Activated protein C (APC), a natural anticoagulant, has been reported to exert direct vascu- loprotective, neural protective, anti-inflammatory, and proneurogenic activities in the central nervous system. This study was aimed to explore the neuroprotective effects and potential mechanisms of APC on the neurovascular unit of neonatal rats with intrauterine infection-induced white matter injury. In- traperitoneal injection of 300 ~tg/kg lipopolysaccharide (LPS) was administered consecutively to preg- nant Sprague-Dawley rats at embryonic days 19 and 20 to establish the rat model of intrauterine infec- tion-induced white matter injury. Control rats were injected with an equivalent amount of sterile saline on the same time. APC at the dosage of 0.2 mg/kg was intraperitoneally injected to neonatal rats imme- diately after birth. Brain tissues were collected at postnatal day 7 and stained with hematoxylin and eo- sin (H&E). Immunohistochemistry was used to evaluate myelin basic protein (MBP) expression in the periventricular white matter region. Blood-brain barrier (BBB) permeability and brain water content ~were measured using Evens Blue dye and wet/dry weight method. Double immunofluorescence staining and real-time quantitative PCR were performed to detect microglial activation and the expression of protease activated receptor 1 (PAR1). Typical pathological changes of white matter injury were ob- served in rat brains exposed to LPS, and MBP expression in the periventricular region was significantly decreased. BBB was disrupted and the brain water content was increased. Microglia were largely acti- vated and the mRNA and protein levels of PAR1 were elevated. APC administration ameliorated the pathological lesions of the white matter and increased MBP expression. BBB permeability and brain water content were reduced. Microglia activation was inhibited and the PAR1 mRNA and protein ex- pression levels were both down-regulated. Our results suggested that APC exerted neuroprotective ef- fects on multiple components of the neurovascular unit in neonatal rats with intrauterine infec- tion-induced white matter injury, and the underlying mechanisms might involve decreased expression of PAR1.
文摘The potential role of the protein kinase C (PKC) transduction systemin controlling proliferation of human pituitary somatotrophinomas was investigat-ed. Twenty somatotrophinomas were studied using PCR and diract sequencing methods. No point mutation within the QPKC gene, previously thought to be as-sociated with invasive pituitary tumors, was found in any of the 20 somatotrophi-nomas. It is concluded that PKC trareduction system may play an important rolein controlling pituitary somatotrophinoma proliferation, but there is no correlation between invasiveness and the previously reported QPKC gene mutation.
基金supported by a grant from the National Natural Sciences Foundation of China (No. 30672161)
文摘This study examined the effect of GHRP-6, a known GHSs receptor agonist, on the phosphorylation of cAMP-responsive element-binding protein (CREB) and the tmderly mechanism. GH3 cells were cultured and subjected to different treatments as follows: GHRP-6, GHRP-6 plus GHRH, phorbol ester (PMA), an activator of PKC, alone or in combination with GHRP-6, G66983, a general inhibitor of PKCs, in the presence or absence of GHRP-6, rottlerin, an inhibitor of PKCs, alone or plus GHRP-6. The cells were transiently transfected with PKCσ-specific siRNA and then treated with GHRP-6. GH level was measured by enzyme-linked immunosorbent assay (ELISA). The expression of phosphor-CREB, PKCσ, PKC0 and phosphor-PKCo was determined by Western blotting. The results showed that GHRP-6 stimulated GH secretion in both time- and dose-dependent manners and enhanced the effect of GHRH on GH secretion. GHRP-6 was also found to induce CREB phosphorylation. Moreover, GH secretion was enhanced by the PKC activator PMA and reduced by the PKC inhibitors (G66983, rottlerin) and knockdown of PKCσ. PKCσ could be activated by GHRP-6. It is concluded that PKC, especialiy PKCσ, mediates CREB phosphorylation and GHRP-6-induced GH secretion.
基金This study was supported by a grant from the National Nature Science Foun-dation of China (No. 30070747)
文摘BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ex-pression of protein kinase C (PKC) and their effects on he-patic metastasis of colorectal cancer.METHODS: High performance liquid chromatography wasused to detect contents of cell membrane phospholipids:phosphatidylinosital (PI), phosphatidylserine (PS), phos-phatidylethanolamine (PE) and phosphatidylcholine (PC)in primary foci, paratumor mucosa and hepatic metastaticfoci in patients with colorectal carcinoma. The mRNA ex-pression levels of PKC-α, -δ, -ε, -λ, -ξ isoenzymeswere detected with the QRT-PCR technique.RESULTS: The levels of PI, PC and PE in primary foci andhepatic metastatic foci were higher than those in paratumormucosa. The level of PE in hepatic metastatic foci wasmuch higher than that in primary foci (t =98.88, P <0.01);but the levels of PI and PC were not significantly differentbetween primary foci and hepatic metastatic foci (t =1.73 ,1.36, P>0.05). The expression levels of -δ, -ε,-λ, -ξ were enhanced in primary foci and hepatic metasta-tic foci, but the level of PKC-α in primary foci was de-creased as compared with that in paratumor mucosa. Thelevels of PKC-δ, -ε, -λ, -ξ in hepatic metastatic foci werehigher than those in primary foci. A positive correlationwas observed between the expression levels of PI, PC andand also between those of PE and PKC-δ, -ε, -λ,-ξ. However, there was a close negative correlation be-tween PE and PKC-α.CONCLUSION: Increased levels of PI and PC and de-creased ratio of PKC-α to are related to colorectalcancer genesis. Increased levels of PE, increased expressionof PKC-δ, -ε, -λ, -ξ isoenzymes and decreased level ofPKC-α are related to hepatic metastasis in colorectal carci-noma.
文摘AIM:To study the protein C activation system in human liver myofibroblasts,and the effects of activated protein C(APC)on these cells.METHODS:Human liver myofibroblasts were obtained by outgrowth.Expression of protease activated receptor 1(PAR-1),endothelial protein C receptor(EPCR) and thrombomodulin(TM)was analyzed by flow cytometry.Extracellular signal-regulated kinase(ERK)1/2 activation was assessed by Western blotting using anti-phospho-ERK antibodies.Collagen synthesis was studied with real-time reverse transcription-polymerase chain reaction(RT-PCR).Activation of protein C was studied by incubating liver myofibroblasts with zymogen protein C in the presence of thrombin and detecting the generation of APC with a colorimetric assay using a peptide substrate. RESULTS:Primary cultures of human liver myofibroblasts expressed EPCR on their surface,together with PAR-1 and TM.This receptor system was functional since exposure of myofibroblasts to APC inducedERK1/2 phosphorylation in a dose-and time-dependent manner.Furthermore,APC significantly upregulated the expression of collagen mRNA,as shown by real-time RT-PCR.Collagen upregulation was controlled through the ERK pathway as it was inhibited when using the mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor PD98059.Finally,using a cell-based colorimetric assay,we showed that intact myofibroblasts converted protein C into APC in the presence of thrombin.CONCLUSION:These data suggest that APC is a new modulator of liver myofibroblast activity and contributes to the pathophysiology of chronic liver diseases.
基金Supported by National Natural Science Foundation of China (No. 81470609 No. 81170825)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20123706110003)the Key Project of Natural Science Foundation of Shandong Province (No. ZR2012FZ001) the Youth Project of Natural Science Foundation of Shandong Province (No. ZR2013HQ007)
文摘AIM: To identify whether Aspergillus fumigatus(A.fumigatus) hyphae antigens induced the release of interleukin-8(IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells(HCECs) and determine the involvement of intracellular signalling pathways. METHODS: HCECs were treated with A. fumigatus hyphae antigens with different concentrations and time.The cytoplasmic calcium of HCECs were assessed by fluorescence imaging. Western blot was used to detect the expression of Ca2 +-dependent protein kinase C(PKC). The IL-8 levels were determined by specific human IL-8 enzyme-linked immunosorbent assay(ELISA) and reverse transcriptase polymerase chain reaction(RT-PCR). Using a series of pharmacological inhibitors, we examined the upstream signalling pathway responsible for IL-8 expression in response to A.fumigatus hyphae antigens. RESULTS: Cells exposed to A. fumigatus hyphae antigens showed higher level of IL-8 m RNA expression and protein production. We demonstrated here that stimulation of HCECs with A. fumigatus hyphae triggers an intracellular Ca2 +flux and results in the activation of Ca2 +-dependent PKC(α, βⅠ and βⅡ) which can be attenuated by pre-treatment of cells with laminarin,suggesting that Dectin-1 signals pathway induced cytoplasmic calcium and influence the activation of PKC in HCECs. Inhibitors of Ca2 +-dependent PKC(Ro-31-8220 and Go6976) significantly abolished hyphae-induced expression of IL-8.CONCLUSION: Our findings suggest that A. fumigatushyphae-induced IL-8 expression was regulated by the activation of Dectin-1-mediated Ca2 +-dependent PKC in HCECs.