PURPOSE:To verify existance of a-,~-,and 3'-protein kinase C(PKC)subspecies and their localization in rabbit retina. METHODS: Using an immunohistoehemical technique with mono- elonal antibodies against PKC isozymes- I (a),-I[ (13),and -~[ (Y) to characterize the distribution of PKC in rabbit retina. RESULTS:There is a positive immunostaining for a-,13-,and ~-PKC in rabbit retina. The immunoreactivity of a-PKC was observed mainly in the bipolar cells of inner nuclear layer and the outer segments of photorecptors. The positive immunostaining of 13-PKC could be seen in the ganglion cells,inner plexiform layer,inner nuclear layer,and the outer segments of photoreceptors. A diffuse and weak staining of Y-PKC is recognized in the ganglion cell layer,inner plexifrom layer,inner nuclear layer, and the outer segments of photoreceptors. CONCLUSION:The protein kinase C sub- speeies-a,-~,and-'Y are present in retina which is a part of the central nervous system
Objective To investigate the effects of cytokines on the expression of syndecan-1 in cultured human retinal pigment epithelial (RPE) cells and the signal transduction pathway. Methods Reverse transcription polymerase chain reaction and immunofluorescence staining were used to detect the expression of syndecan-1 mRNA and protein in normal RPE cells. The expression of syndecan-1 in RPE cells stimulated by different cytokines was detected and quantitatively analyzed by image process of immunofluorescence. The stimulation included 7 and 35 ng/ml tumor necrosis factor (TNF)-alpha; for 24 hours, 1 and 6 mu;g/ml lipopolysaccharide (LPS) for 11 hours, 7 ng/ml TNF-alpha; for 0 to 24 hours (once per 2 hours, and 13 times in total), and 30% supernatant of monocyte/macrophage strain (THP-1 cells) for 3, 14 and 43 hours. The effect of 30% supernatant of THP-1 cells was assayed after pretreated by PD098059［the specific inhibitor of extracellular signal regulated kinase(ERK) 1/2］for 2 hours. After exposed to 30% supernatant of THP-1 cells for 3 hours and treated by 0.25% trypsin for 5 minutes, RPE cells attaching was evaluated by methyl thiazolyl tetrazolium assay. Results In normal human RPE cells, expressions of syndecan-1 mRNA and protein were detected, and b syndecan-1 positive yellowish green fluorescence was found in the cell membrane and cytoplasm while light green fluorescence was in the nucleus. As the concentration and stimulated time of TNF-alpha; or LPS increased, the fluorescence intensity decreased（Plt;0.01）, and after exposed to 30% supernatant of THP-1 cells, weaker fluorescence intensity was detected (Plt;0.001). Pretreatment with 50 mu;mol/L PD098059 for 2 hours partly inhibited the effect of THP-1 cells supernatant. After exposed to 30% supernatant of THP-1 cells for 3 hours, the number of attached cells decreased compared with the controls（Plt;0.05）. Conclusions TNF-alpha; and LPS down-regulate the expression of syndecan-1 in cultured human RPE cells. The supernatant of THP-1 cells down-regulates the expression of syndecan-1 and lessens the cells attaching, which is at least mediated by ERK 1/2 pathway. (Chin J Ocul Fundus Dis, 2006, 22: 113-116)
Objective To find a new specific marker that can be used to early diagnose hepatic fibrosis by detecting the change of serum protein in patients with hepatic fibrosis. Methods This research adopted 50 SD rats (25 males and 25 females), and from which 6 rats were selected randomly (3 males and 3 females) as control group, last 44 rates were divided into four groups according to four pathological stages as hepatic fibrosis model group (experimental group). Distinct proteins in serum were detected by surface-enhanced laser desorption/ionization-time of flight-mass spectra (SELDI-TOF-MS). Radioimmunoassay was used to measure four parameters of hepatic fibrosis which were hyaluronidase (HA), precollagen Ⅲ (PCⅢ), laminin (LN) and collagen Ⅳ (Ⅳ-C). Results Distinct proteins in serum were detected in 8 cases of stage Ⅰ of hapatic fibrosis, 5 cases of stage Ⅱ, 5 cases of stage Ⅲ, 6 cases of stage Ⅳ, and 5 cases of control by SELDI-TOF-MS. Three protein peaks were found (M/Z: 4 203, 4 658, and 7 400). The peaks of M/Z 4 658 and 4 700 proteins were obviously increased in the stage Ⅰ of hepatic fibrosis （Plt;0.05）, while the changes of hepatic fibrosis four parameters appeared in stage Ⅳ of hepatic fibrosis. Conclusion This method shows great potential for early diagnosing of hepatic fibrosis and finding better biomarkers to hepatic fibrosis.
Objective To investigate the role of ephrin A genes in the development of oxygen induced retinalneovascularization (OIR) in mice.Methods The OIR model was established by oxygen induction in new born C57BL/6J mice.Reversed transcript polymerase chain reaction (RT-PCR) was used to measure the expression levels of ephrin A1-A5 in retinas of mice in experimental and normal control group.Results All of the ephrin A family genes expressed in normal retinas. Ephrin A1 mRNA was significantly higher in OIR group(t=3.19,P=0.019); ephrin A2 mRNA was higher in the 15-day-old OIR retinas(t=3.71,P=0.033）; ephrin A3-A5 mRNA decreased or disappeared in 12 and 13-day-old RNV mice, and increased in 15-day-old OIR mice. Conclusion Ephrin A genes are involved in the development of retina and OIR.
Objective To describe cultured human retinal pigment epithelial (RPE) cells transdifferentiation and investigate the effects of human vitreous fluid on the morphologic and cytoskeleton changes of RPE cells in vitro. Methods Cytoskeleton characteristics in the 2nd, 5th, 8th passage of RPE cells in normal culture, which included cytokeratin 18 (CK18) and α-smooth muscle actin (α-SMA) were analyzed by Western blot. RPE cells were cultured in human vitreous-conditioned medium (VCM) at the concentration of 1∶4 for 6 days, morphologic changes were examined by light and electron microscopy, and cytoskeleton characteristics were analyzed by imunocytochemistry and Western blot. Results During culture in vitro, RPE cells lost epithelial characteristics and aquired fibroblast-like phenotype. The expression of CK18 was the highest at the 5th passage, and it decreased in the following passage, but α-SMA increased gradually. The morphologic transdifferentiation from epithelial to fibroblast-like cells of RPE was accelerated by VCM. Ultrastructural changes such as decreased microvilli and gradually increased rough endoplasmic reticulum and Golgi complex were found during the cultivation. CK18 produced by RPE cells decreased in VMC (P＜0.05), and α-SMA increased (P＜0.01). Conclusion Morphologic changes in epithelialmesenchymal transdifferenetiation of RPE cells are stimulated by VCM and accomplied by the shift of cytoskeleton proteins, The results imply that cells migration may be decreased and contraction may be enhanced in VCM. It may suggest that vitreous accelerates the pathogenesis of PVR and RPE cells play an important role. (Chin J Ocul Fundus Dis, 2002, 18: 289-292)
Objective To investigate the effect of hypericin on the activity of protein kinase C (PKC) in cultured human retinal pigment epithelium (RPE) cells in vitro.Methods RPE cells were cultured in standard medium with 10% serum concentrations containing 0.5 to 5.0 μmol/L hypericin with or without preincubation of phorbol 12-myristate 13-acetate (PMA). The activities of cytosolic PKC (c-PKC) and membranous PKC (m-PKC) were assayed by PKC kit. Results The original activities of c-PKC and m-PKC of RPE cells were (35.34±4.10) pmol·min-1·mg-1and (62.52±8.80) pmol·min-1·mg-1.The activity of c-PKC in RPE cells with PMA preincubation decreased rapidly in 5 minutes, with a subsequent slow decrease after 20 minutes and a decrease to 18% of the activity of c-PKC in RPE cells without PMA preinubation after 60 minutes. While the activity of m-PKC in RPE cells with PMA preincubation increased gradually after 5 minutes and reduced after reached the peak at 40 minutes, and then returned to baseline after 60 minutes, eventually decreased below 30% of the control group. When RPE cells were cultured with PMA for 48 hours, the activities of c-PKC and m-PKC were hardly detectable, while RPE cells were cultured with both PMA and hypericin, hypericin could counteract most of down-regulation by PMA. Conclusion Hypericin may inhibit the translocation of PKC in RPE cells,change the activity of PKC, promote the apoptosis of RPE cells likely,and then prevent proliferative vitreoretinopathy. (Chin J Ocul Fundus Dis，2003，19：55-58)
Diabetic retinopathy (DR), a neurovascular complication of diabetes, presents a multifaceted pathogenesis that encompasses numerous biological processes and molecular mechanisms. Endoplasmic reticulum stress (ERS) plays a critical role in the maintenance of cellular homeostasis, and diabetic neuro-microangiopathy is driven by high glucose, which activated ERS through the promotion of protein misfolding, oxidative stress, and disturbances in calcium homeostasis. ERS activates the unfolded protein response, thereby influencing the onset and progression of DR through modulating mitochondria-associated endoplasmic reticulum membranes, autophagy, apoptosis, microvascular function, oxidative stress, and inflammation pathways. Currently, the principal interventions against ERS comprise the modulation of the ERS signalling axis and its interactions with associated pathological processes such as autophagy, oxidative stress, and inflammation, through pharmacological and molecular mechanisms. These interventions are directly or indirectly shown to inhibit persistent ERS and are demonstrated to ameliorate DR. With the in-depth study of ERS and the research and development of various drugs for ERS, it is expected to bring novel insights and strategies for DR management in the future.
Lung cancer is one of the most malignant common tumor worldwidely and it's the most popular cancer in China. Both the prevalence and mortality of it are higher than other cancers. And its 5-year survival rate is 15%. Non-small cell lung cancer(NSCLC) accounts for about 85% lung cancer and its pathogenesis has not been elucidated. Therefore, early prediction and detection are very important for improving the effect of treatment and prognosis. Recently, dysregulation and excessive activity of the C4.4A as a member of the LY6/uPAR family of membrane proteins has been shown to associate with multiple cancer types. And previous studies suggest that the C4.4A participates in the invasion and metastasis of NSCLC. At the same time, circumstantial evidence proves that C4.4A and liver kinase B1(LKB1) tumor suppressor gene have a negative regulatory relationship. This article will briefly summarize the recent research progresses of C4.4A in NSCLC.
PURPOSE:To evaluate the activitv of protein kinase C(PKC) in response to retinal photochemical insult in rat. Furthermore, to investigate the effect of dexamethasone(DXM ) on PKC activity. METHODS :The experiments were performed on 48 SI') rats whieh were separated into two groups,control and treated groups,and the latter received daily intraperitoneal injections of DXM (1 mg/kg)for 5 consecutive days,starting 3 days before light exposure. The animals were continually exposed to green fluorescent light (510nm~560nm) with an illuminance level of (1 900plusmn;106.9)lx for 24 hrs.The retinal enzyme activity of PKC was tested at 6 hrs,1 day,3 days,7 days,and 14 days after light exposure respectively. RESULTS:In animal models,PKC activity showed a transient increase in both groups at 6 hrs after light exposure and then decrease persistently there alter. The activity of PKC was unresponsive to DXM intervention. CONCLUSIONS :These results suggested that the persistent lower PKC activity might result in disturbance of retinal function in rat retinal photochemical injury. （Chin J Ocul Fundus Dis,1997,13: 78-80）
ObjectiveTo evaluate the screening performance of commonly used renal function indicators for chronic kidney disease (CKD) in subjects of different ages, so as to explore the appropriate screening regimen for Chinese population.MethodsA total of 2 131 adult subjects in Sichuan Orthopaedic Hospital or Mianyang Central Hospital from May 2016 to October 2017 were selected. They were divided into three groups according to age: group A (18–39 years, n=278), group B (40–64 years, n=1 167), and group C (≥65 years, n=686). Serum levels of creatinine (SCr), urea, and cystatin C [CysC; to calculate estimated glomerular filtration rate (eGFR) based on this index], as well as urine levels of albumin, total protein and creatinine were measured, and urine albumin to creatinine ratio (ACR) and urine protein to creatinine ratio (PCR) were calculated respectively. CKD was diagnosed according to the Kidney Disease: Improving Global Outcomes (KDIGO) Guideline (2012 Edition). The receiver-operating characteristic (ROC) curve analysis was finally performed to investigate the diagnostic performance of each indicator for CKD.ResultsThe prevalences of CKD in group A, B, and C were 10.8% (30/278), 16.4% (191/1 167), and 45.8% (314/686), respectively, and the difference among these groups was statistically significant (χ2=233.525, P<0.001). In addition, the levels of the six renal function indicators between CKD and non-CKD subjects also had statistically significant differences in different age groups (P<0 05="" otherwise="" roc="" curve="" analysis="" revealed="" that="" the="" diagnostic="" values="" of="" these="" indicators="" were:="" acr="" or="" pcr=""> eGFR or CysC > serum urea or SCr (AllP<0 05="" except="" that="" egfr="" cysc="" serum="" urea="" and="" scr="" in="" group="" a="" assessed="" the="" similar="" diagnostic="" performance="" among="" the="" three="" indicators="" recommended="" by="" kdigo="" guideline="" the="" diagnostic="" performances="" of="" acr="" and="" pcr="" in="" different="" age="" groups="" were:="" group="" b="" 0="" 915="" 0="" 914=""> group A (0.885, 0.890) > group C (0.841, 0.846), while the diagnostic performance of eGFR was group C (0.807) > group B (0.728) > group A (0.696). The best boundary values of ACR and PCR were lower while the value of eGFR was higher than the corresponding KDIGO recommended medical decision levels.ConclusionsACR is the first choice for screening CKD when the renal function index creatinine is normal. Moreover, eGFR can further improve the diagnostic value, especially in subjects over 65 years old.