Preliminary exploration of animal models of congenital choledochal cysts.

BACKGROUND: Various animal models have been used to explore the pathogenesis of choledochal cysts (CCs), but with little convincing results. Current surgical techniques can achieve satisfactory outcomes for treatment of CCs. Consequently, recent studies have focused more on clinical issues rather than basic research. Therefore, we need appropriate animal models to further basic research. AIM: To establish an appropriate animal model that may contribute to the investigation of the pathogenesis of CCs. METHODS: Eighty-four specific pathogen-free female Sprague-Dawley rats were randomly allocated to a surgical group, sham surgical group, or control group. A rat model of CC was established by partial ligation of the bile duct. The reliability of the model was confirmed by measurements of serum biochemical indices, morphology of common bile ducts of the rats as well as molecular biology experiments in rat and human tissues. RESULTS: Dilation classified as mild (diameter, ≥ 1 mm to < 3 mm), moderate (≥ 3 mm to < 10 mm), and severe (≥ 10 mm) was observed in 17, 17, and 2 rats in the surgical group, respectively, while no dilation was observed in the control and sham surgical groups. Serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, and total bile acids were significantly elevated in the surgical group as compared to the control group 7 d after surgery, while direct bilirubin, total bilirubin, and gamma-glutamyltransferase were further increased 14 d after surgery. Most of the biochemical indices gradually decreased to normal ranges 28 d after surgery. The protein expression trend of signal transducer and activator of transcription 3 in rat model was consistent with the human CC tissues. CONCLUSION: The model of partial ligation of the bile duct of juvenile rats could morphologically simulate the cystic or fusiform CC, which may contribute to investigating the pathogenesis of CC.

Intravitreal injection of conbercept for diabetic macular edema complicated with diabetic nephropathy.

AIM: To observe the therapeutic effect of conbercept on diabetic macular edema (DME) complicated with diabetic nephropathy (DN). METHODS: In this retrospective study, 54 patients (54 eyes) that diagnosed as DME from January 2017 to October 2021 were collected. The patients were divided into two groups: DME patients with DN (25 eyes), and DME patients without DN (29 eyes). General conditions were collected before treatment, laboratory tests include fasting blood glucose, HbA1c, microalbumin/creatinine, serum creatinine. Optical coherence tomography (OCT) was used to check the ellipsoidal zone (EZ) and external limiting membrane (ELM) integrity. Central macular thickness (CMT), best corrected visual acuity (BCVA), and retinal hyperreflective foci (HF) as well as numbers of injections were recorded. RESULTS: There were significant differences between fasting blood glucose, HbA1c, serum creatinine, urinary microalbumin/creatinine, and estimated glomerular filtration rate (eGFR) between the two groups (all P<0.05). EZ and ELM continuity in the DME+DN group was worse than that in the DME group (P<0.05). BCVA (logMAR) in the DME group was significantly better than that in the DME+DN group at the same time points during treatment (all P<0.05). CMT and HF values were significantly higher in the DME+DN group than that in the DME group at the all time points (all P<0.05) and significantly decreased in both groups with time during treatment. At 6mo after treatment, the mean number of injections in the DME+DN and DME group was 4.84±0.94 and 3.79±0.86, respectively. CONCLUSION: Conbercept has a significant effect in short-term treatment of DME patients with or without DN, and can significantly ameliorate BCVA, CMT and the number of HF, treatment efficacy of DME patients without DN is better than that of DME patients with DN.

FAM171B as a Novel Biomarker Mediates Tissue Immune Microenvironment in Pulmonary Arterial Hypertension.

The purpose of this study was to uncover potential diagnostic indicators of pulmonary arterial hypertension (PAH), evaluate the function of immune cells in the pathogenesis of the disease, and find innovative treatment targets and medicines with the potential to enhance prognosis. Gene Expression Omnibus was utilized to acquire the PAH datasets. We recognized differentially expressed genes (DEGs) and investigated their functions utilizing R software. Weighted gene coexpression network analysis, least absolute shrinkage and selection operators, and support vector machines were used to identify biomarkers. The extent of immune cell infiltration in the normal and PAH tissues was determined using CIBERSORT. Additionally, the association between diagnostic markers and immune cells was analyzed. In this study, 258DEGs were used to analyze the disease ontology. Most DEGs were linked with atherosclerosis, arteriosclerotic cardiovascular disease, and lung disease, including obstructive lung disease. Gene set enrichment analysis revealed that compared to normal samples, results from PAH patients were mostly associated with ECM-receptor interaction, arrhythmogenic right ventricular cardiomyopathy, the Wnt signaling pathway, and focal adhesion. FAM171B was identified as a biomarker for PAH (area under the curve = 0.873). The mechanism underlying PAH may be mediated by nave CD4 T cells, resting memory CD4 T cells, resting NK cells, monocytes, activated dendritic cells, resting mast cells, and neutrophils, according to an investigation of immune cell infiltration. FAM171B expression was also associated with resting mast cells, monocytes, and CD8 T cells. The results suggest that PAH may be closely related to FAM171B with high diagnostic performance and associated with immune cell infiltration, suggesting that FAM171B may promote the progression of PAH by stimulating immune infiltration and immune response. This study provides valuable insights into the pathogenesis and treatment of PAH.

Efficacy of intravitreal conbercept injection on short- and long-term macular edema in branch retinal vein occlusion.

AIM: To observe the best-corrected visual acuity (BCVA) and central foveal thickness (CFT) repeatedly after the intravitreal injection of conbercept (IVC) for treating cystoid macular edema (CME) in branch retinal vein occlusion (BRVO) and explore the relationship between the duration of CME and visual outcome. METHODS: Subgroup analysis was performed to compare short-term (within 90d of CME onset) and long-term (over 90d of CME onset) macular edema in BRVO. After an initial IVC, a pro re nata (PRN) strategy was performed according to the recurrence of CFT or decrease of BCVA. Analysis of variance using repeated measurements, statistical analysis following indicators including BCVA and CFT collected at baseline and 1, 3, and 6mo after IVC. RESULTS: Among the 60 cases included in this retrospective study, 36 were short-term CME, and 24 were long-term CME. There were statistical significances between and within groups of the BCVAs at different time points (P<0.001). The interaction was found between group and time (P=0.006), indicating the difference in the speed of BCVA improvement between groups. In particular, the improvement speed of BCVA in the short-term CME group was faster than that in the long-term CME group. There were significant differences between and with groups of the CFT at different time points (P<0.001). However, the interaction between group and time in relation to CFT had no significant differences (P=0.59). CONCLUSION: IVC treatment for CME following BRVO is effective and safe. The duration of CME before treatment is a significant predictor of the visual outcomes of patients with BRVO. The improvement of vision might be faster with early IVC treatment than with delayed treatment.

The relationship of blood cell-associated inflammatory indices and diabetic retinopathy: a Meta-analysis and systematic review.

AIM: To explore the correlation between several blood cell-associated inflammatory indices including mean platelet volume (MPV), platelet distribution width (PDW), neutrophil to lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), and the presence and severity of diabetic retinopathy (DR). METHODS: We searched for eligible studies from PubMed, EMBASE, Web of Science and CNKI up to December 13, 2017. Standardized mean difference (SMD) calculated with confidence interval (CI) of 95% was used to estimate the values of those indices. RESULTS: A total of 31 studies were included in the present Meta-analysis. As compared with type 2 diabetes mellitus (T2DM) patients without DR, the values of MPV, PDW, NLR, and PLR were higher in patients with DR (SMD=0.67; 95%CI: 0.36 to 0.98; SMD=0.51; 95%CI: 0.27 to 0.75; SMD=0.77; 95%CI: 0.49 to 1.05 and SMD=1.18; 95%CI: 0.07 to 2.28). Additionally, it was also observed that MPV was closely correlated with the severity of DR. CONCLUSION: MPV, PDW, NLR, and PLR could be recommended as diagnostic biomarkers for DR, and MPV could be applied to assess the severity of DR.

Inhibitory effect of Sophora subprosrate polysaccharide on mitochondria oxidative stress induced by PCV-2 infection in RAW264.7 cells.

In the present study, the inhibitory effect of Sophora subprosrate polysaccharide (SSP) on PCV-2-induced mitochondrial respiratory burst in RAW264.7 cells was first investigated. The findings suggested that SOD activity and the anti-superoxide anion radical activity of the RAW264.7 cells were significantly decreased after PCV-2 infection, and MnSOD mRNA levels were significantly decreased, while NOX2 mRNA levels and protein expression were increased. Meanwhile, the O2•- levels and mitochondrial membrane potentials were significantly increased. After treatment with SSP, significant increases in the activities of SOD, anti-superoxide anion radical activities, and MnSOD mRNA levels in the PCV-2 infected cells were observed. Meanwhile, significant increases in NOX2 mRNA levels and protein expression, O2•- levels and mitochondrial membrane potentials were also observed. The results showed that PCV2 infection resulted in the mitochondria oxidative stress of RAW264.7 cells as indicated by an increasing mitochondrial membrane potential, which was then inhibited by SSP. It was concluded that RAW264.7 cells treated with SSP could suffer from mitochondrial damage, which may be mediated by the inhibition of the mitochondrial membrane potential.

In Vitro and In Vivo Synergistic Therapeutic Effect of Cisplatin with Human Papillomavirus16 E6/E7 CRISPR/Cas9 on Cervical Cancer Cell Line.

PURPOSE: Human papillomavirus (HPV) type 16 is one of the major etiologic factors of cervical cancer. Our study aims to investigate the potentiality of the antiviral clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated Cas9 system (CRISPR/Cas9) targeting the E6 and E7 oncogenes of HPV16 as a potential chemosensitizer of cisplatin (cis-diaminedichloroplatinum II; CDDP) for cervical cancer. METHODS: Specifically, the therapeutic efficacy of combination of CDDP and HPV16 E6 + E7-CRISPR/Cas9 was assessed in cervical cancer cells and cervical cancer xenograft models. RESULTS: In vitro experiments showed that long-term exposure of SiHa cells to the HPV16 E6 + E7-CRISPR/Cas9 induced apoptosis, and its pro-apoptosis effect became more obvious when combined with CDDP. In vivo study found the efficacy of the combination of HPV16 E6 + E7-CRISPR/Cas9 and CDDP were superior to either of the treatments in term of apoptosis induction and metastasis inhibition. CONCLUSION: Collectively, our results suggested that HPV16 E6 + E7-CRISPR/Cas9 could be an effective sensitizer of CDDP chemotherapy in cervical cancer.

Human ß-NGF gene transferred to cat corneal endothelial cells.

AIM: To transfect the cat corneal endothelial cells (CECs) with recombinant human ß-nerve growth factor gene adeno-associated virus (AAV-ß-NGF) and to observe the effect of the expressed ß-NGF protein on the proliferation activity of cat CECs. METHODS: The endothelium of cat cornea was torn under the microscope and rapidly cultivated in Dulbecco's modified Eagle's medium (DMEM) to form single layer CECs and the passage 2 endothelial cells were used in this experiment. The recombinant human AAV-ß-NGF was constructed. The recombinant human AAV-ß-NGF was transferred into cat CECs directly. Three groups were as following: normal CEC control group, CEC-AAV control group and recombinant CEC-AAV-ß-NGF group. Forty-eight hours after transfection, the total RNA was extracted from the CEC by Trizol. The expression of the ß-NGF target gene detected by fluorescence quantitative polymerase chain reaction; proliferation activity of the transfected CEC detected at 48h by MTT assay; the percentage of G1 cells among CECs after transfect was detected by flow cytometry method (FCM); cell morphology was observed under inverted phase contrast microscope. RESULTS: The torn endothelium culture technique rapidly cultivated single layer cat corneal endothelial cells. The self-designed primers for the target gene and reference gene were efficient and special confirmed through electrophoresis analysis and DNA sequencing. Forty-eight hours after transfect, the human ß-NGF gene mRNA detected by fluorescence quantitative polymerase chain reaction showed that there was no significant difference between normal CEC control group and CEC-AAV control group (P>0.05); there was significant difference between two control groups and recombinant CEC-AAV-ß-NGF group (P<0.05). MTT assay showed that transfect of recombinant AAV-ß-NGF promoted the proliferation activity of cat CEC, while there was no significant difference between normal CEC control group and CEC-AAV control group (P>0.05). FCM result showed that the percentage of G1cells in CEC-AAV-NGF group was 76.8% while that in normal CEC control group and CEC-AAV control group was 46.6% and 49.8%. CONCLUSION: Recombinant AAV-ß-NGF promotes proliferation in cat CECs by expressing bioactive ß-NGF protein in high efficiency and suggests that its modulation can be used to treat vision loss secondary to corneal endothelial dysfunction.

[Research on the Combined Detection of Urine UmAlb and Urinary Nephrin, Podocalyxin in Podocyte of MKR Mice with Diabetic Nephropathy].

OBJECTIVE: To explore the combined detection of urine UmAlb and urinary nephrin (Unephrin), podocalyxin (UPCX) in podocyte of MKR mice with diabetic nephropathy. METHODS: Thirty 8 weeks old MKR mice were randomly divided into two groups as follows: negative control group, DN model group, and another 15 wild C57 mice were used as normal control. Mice in DN model group were received unilateral nephrectomy and high-fat diet feed for 2 months. The morphological structure changes of the podocytes were observed by transmission electron microscopes. The levels of FBG were detected by electrochemical detection method, The nephrin and PCX protein expression were measured by western blotting. The levels of UmAlb, Unephrin and UPCX were detected by ELISA. RESULTS: The podocyte damage in the mice of DN model group increased significantly when compared with normal control. As compared with normal control, FBG in the model group increased significantly (P<0. 01), the expression level of nephrin and PCX in Renal Tissue and Unephrin, UPCX, and urine UmAlb were also increased significantly (P<0. 01). CONCLUSION: The level of Unephrin and UPCX were positive correlated with the level of urine UmAlb, the loss of podocyte strcture protein might be one of the mechanism in leading proteinuria in diabetic nephropathy.

A dietary polyphenol resveratrol acts to provide neuroprotection in recurrent stroke models by regulating AMPK and SIRT1 signaling, thereby reducing energy requirements during ischemia.

Polyphenol resveratrol (RSV) has been associated with Silent Information Regulator T1 (SIRT1) and AMP-activated protein kinase (AMPK) metabolic stress sensors and probably responds to the intracellular energy status. Our aim here was to investigate the neuroprotective effects of RSV and its association with SIRT1 and AMPK signaling in recurrent ischemia models. In this study, elderly male Wistar rats received a combination of two mild transient middle cerebral artery occlusions (tMCAOs) as an in vivo recurrent ischemic model. Primary cultured cortical neuronal cells subjected to combined oxygen-glucose deprivation (OGD) were used as an in vitro recurrent ischemic model. RSV administration significantly reduced infarct volumes, improved behavioral deficits and protected neuronal cells from cell death in recurrent ischemic stroke models in vivo and in vitro. RSV treatments significantly increased the intracellular NAD(+) /NADH ratio, AMPK and SIRT1 activities, decreased energy assumption and restored cell energy ATP level. SIRT1 and AMPK inhibitors and specific small interfering RNA (siRNA) for SIRT1 and AMPK significantly abrogated the neuroprotection induced by RSV. AMPK-siRNA and inhibitor decreased SIRT1 activities; however, SIRT1-siRNA and inhibitor had no impact on phospho-AMPK (p-AMPK) levels. These results indicated that the neuroprotective effects of RSV increased the intracellular NAD(+) /NADH ratio as well as AMPK and SIRT1 activities, thereby reducing energy ATP requirements during ischemia. SIRT1 is a downstream target of p-AMPK signaling induced by RSV in the recurrent ischemic stroke model.

Modulation of CD147-induced matrix metalloproteinase activity: role of CD147 N-glycosylation.

Degradation of the basement membrane by MMPs (matrix metalloproteinases) is one of the most critical steps in tumour progression. CD147 is a tumour-associated antigen that plays a key regulatory role for MMP activities. In the present study, mass spectrum analysis demonstrated that the purified native CD147 from human lung cancer tissue was N-glycosylated and contained a series of high-mannose and complex-type N-linked glycan structures. Moreover, native glycosylated CD147 existed exclusively as oligomers in solution and directly stimulated MMP production more efficiently than non-glycosylated prokaryotic CD147. The glycosylation site mutation results indicated that, among three N-glycan attachment sites, the N152Q mutants were retained in the endoplasmic reticulum and unfolded protein response signalling was activated. This improper intracellular accumulation impaired its MMP-inducing activity. Increased ß1,6-branching of N-glycans as a result of overexpression of GnT-V (N-acetylglucosaminyltransferase V) plays an important role in tumour metastasis. In the present study, we identified CD147 as a target protein of GnT-V and found that overexpression of GnT-V resulted in an elevated level of CD147 at the plasma membrane and in cell-conditioned medium, thereby increasing the induction of MMPs. The present study reveals the important role of N-glycosylation of CD147 in its biological function and implied that targeting aberrant ß1,6-branching of N-glycans on CD147 would be valuable for the development of novel therapeutic modalities against carcinoma.

Effect of recombinant human platelet-derived growth factor B on cat corneal endothelial cell viability mediated by adeno-associated virus.

AIM: To transduce recombinant human platelet-derived growth factor B(PDGF-B) gene adeno-associated virus(AAV) to in vitro cultured cat corneal endothelial cell (CEC) and observe the effect of the expressed PDGF-BB protein on the viability of cat CEC. METHODS: Cat cornea endothelium was torn under microscope and rapidly cultivated in DMEM to form single layer CEC and the passage 2 endothelial cells were used in this study. The recombinant human PDGF-B gene AAV was constructed and transduced into cat CEC directly. Three groups were as following: blank control group, AAV control group and recombinant AAV group. At 24 hours, 48 hours, and 5 days after transduction, total RNA was extracted from the CEC by Trizol and the expression of PDGF-B gene was detected by fluorescence quantitative polymerase chain reaction. Viability of the transduced CEC was detected at 48 hours after transduction by MTT assay. Cell morphology was observed under inverted phase contrast microscope. RESULTS: With the torn endothelium culture technique, we rapidly got single layer cat CEC. At 24 hours, 48 hours and 5 days after transduction, fluorescence quantitative polymerase chain reaction showed there was no significant difference of the expressed PDGF-B gene mRNA between blank control group and AAV control group (P>0.05). In contrast, there were significant differences between two control groups and recombinant AAV group (P<0.05). MTT assay showed that in recombinant AAV group, the expressed PDGF-BB protein could promote the viability of cat CEC. Morphology observation showed at 48 hours after transduction, cells in CEC-AAV-PDGF-B group proliferated into bigger scales in regular triangle to hexagon shape with distinct boundary, while the number of cells was significantly less in the two control groups. CONCLUSION: The recombinant AAV-PDGF-B expresses biological active PDGF-BB protein in cat CECs, which promotes the viability and proliferation of cells.

The study of human PDGF-B gene transferred to cat corneal endothelial cells.

AIM: To demonstrate that human platelet-derived growth factor-B (PDGF-B) cDNA could be expressed in primary cultured cat corneal endothelia cells by using gene transfer techniques; to explore a useful tool for the further studies of the molecular mechanisms of corneal endothelium failure and provide a potential effective genetic therapy for the blind patients. METHODS: Human PDGF-B cDNA was isolated from human placent by RT-PCR and inserted into pcDNA(4) vector to construct recombinant eukaryotic expression plasmid pcDNA(4)-PDGF-B. The full length was confirmed by the DNA sequencing analysis. By tearing endothelium technique we obtained pure single layer of cat corneal endothelial cells. The pcDNA(4)-PDGF-B eukaryotic expression vector was transferred into cat corneal endothelial cells by Effectene™ lipofectine. The transfection efficiency of Effectene™ lipofectine in pcDNA(4)-B was detected with pcDNA(4)-GFP. 5 days later, RT-PCR was used to check the PDGF-B expression. Cell viability was tested by modified tertrozalium salt (MTT) method. Cell morphology was observed under inverted phase contrast microscope. RESULTS: The human PDGF-B cDNA was isolated successfully from healthy parturien placent tissue and the sequence was confirmed by computer automatic sequence and PCR analysis. Pure single layer cat corneal endothelial cells were successfully cultured by tearing endothelium technique. Effectene™ lipofectine transfection technique could be effectively used to transfer pcDNA(4)-PDGF-B into cat corneal endothelial cells in vitro, the transfection efficiency was 30%. RT-PCR result showed that human PDGF-B gene was highly expressed in transfected cat corneal endothelial cells. The expressed PDGF-BB protein promoted the viability of cat corneal endothelial cells. CONCLUSION: Human platelet-derived growth factor-B (PDGF-B) cDNA could be highly expressed in cultured cat corneal endothelial cells by gene transfection techniques. Expressed PDGF-BB protein significantly promoted the viability of cat corneal endothelial cells, thus provided a potential effective method for corneal endothelium blindness genetic therapy.

[Mechanisms of preventive effect of tetrandrine on acquired multidrug resistance in K562 cells].

This study was purposed to explore the mechanisms of preventive effect of tetrandrine (TTD) on doxorubicin (ADM)-induced multidrug resistance (MDR) in human leukemia cell line K562 from two aspects of the transcription control of MDR1 gene and cell apoptosis. The experiment was divided into 3 groups: group I-blank control; group II-ADM-induced drug-resistance; group III-ADM-induced drug-resistance after pretreatment with TTD. Reverse transcription-PCR (RT-PCR) was used to detect the mRNA expression levels of c-Jun, YB-1 and Survivin genes. Western blot was used to determine the nuclear protein expression levels of c-Jun and YB-1. Flow cytometry was used to assay the apoptosis of cells. The results showed that as compared with group I, the expression levels of c-Jun mRNA and nuclear protein decreased (p < 0.05), as well as the expression levels of YB-1 mRNA and nuclear protein increased in group II (p < 0.05). However, the expression of Survivin mRNA had no change (p > 0.05); the apoptosis rate of cells was 8.31%. As compared with group II, the expression levels of c-Jun mRNA and nuclear protein increased (p < 0.05), expression levels of YB-1 mRNA and nuclear protein as well as Survivin mRNA decreased in group III (p < 0.05). The apoptosis of cells was 97.2%. It is concluded that TTD can inhibit the expression of YB-1 and up-regulate the expression of c-Jun, thus inhibit the expression of MDR1 gene. TTD can also inhibit the expression of Survivin and increase the apoptosis of cells induced by ADM.

Effect of basic fibroblast growth factor on cat corneal endothelial cell proliferation.

AIM: To investigate the function of basic fibroblast growth factor (bFGF) on cat corneal endothelial cells proliferation. METHODS: Cat corneal endothelial cells were primarily cultured, stimulated with bFGF for different period, the proliferation of cells was assayed by modified tertrozalium salt (MTT) method, and the morphologic changes were observed with inverted phase contrast microscope and transmission electron microscope. RESULTS: At 1, 3 and 5 days after bFGF was added to cat corneal endothelial cells, the result of MTT in 490nm showed significant difference than that in control group, and the difference was most significant in 10ng/mL group. CONCLUSION: bFGF can promote proliferation of cat corneal endothelial cells. 10ng/mL is the relatively most effective dose.

Cloning, expression and functional analyses of human platelet-derived growth factor-B chain peptide for wound repair of cat corneal endothelial cells.

OBJECTIVE: To investigate the biological function of platelet-derived growth factor B (PDGF-B) on the survival and proliferation of cat corneal endothelial cells so as to provide bases for further studies of its role in wound repair and its clinical application. METHODS: Total RNA was extracted from the placenta tissues of healthy pregnant women undergoing hysterotokotomy and PDGF cDNA was obtained with reverse transcription-polymerase chain reaction (RT-PCR). The prokaryotic expression vector pET-PDGF-B was constructed and expressed the recombinant PDGF-B in Escherichia coli (E. coli) BL21 (DE3). After purification and refolding on Ni2+-chelation affinity chromatography (NTA) column, it was used to culture cat corneal endothelial cells. Cell proliferation was tested by modified tertrazolium salt (MTT) and flow cytometer. And the morphologic change and the ultrastructure were observed under an inverted phase contrast microscope, a scanning electron microscope and a transmission electon microscope, respectively. RESULTS: PDGF-B chain peptide (PDGF-BB) gene was successfully inserted into the prokaryotic expression vector, pET-28a (+). The purified recombined protein pET-PDGF-B showed a single band on sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE) with the molecular weight of about 27 u, which was in agreement with the deduced value. MTT and flow cytometry showed that PDGF-BB promoted the survival and proliferation of cat corneal endothelial cells. CONCLUSIONS: The construction of recombinant prokaryotic expression vector pET-PDGF-B and the preparation of PDGF-BB protein provide a foundation for further study of the function of PDGF-BB and producing biological PDGF-BB protein. The expressed PDGF-BB promotes the proliferation of cultured cat corneal endothelial cells.

[Effect of tetrandrine on the doxorubicin-induced expression of mdr1 gene in K562 cells].

OBJECTIVE: To investigate the effect of tetrandrine (TTD) on doxorubicin-induced mdr1 gene expression and its mechanism. METHODS: MTT assay was used to detect the cytotoxicity of TTD to K562 cells. K562 cells were treated with doxorubicin alone or 0.6 microg/ml doxorubicin combined with various concentrations of TTD. RT-PCR was used to detect the mRNA expression of mdr1 and NF-kappa B. Flow cytometry was used to assay the expression of P-glycoprotein (P-gp). Intracellular rhodamine 123 (Rho123) retention assay was applied to test the P-gp function. RESULTS: After treatment with 0.6 microg/ml doxorubicin for 24 hours, the expressions of mdr1 mRNA, NF-kappa B mRNA and P-gp in K562 cells were increased from 0.171 +/- 0.012, 0.783 +/- 0.090, 7.85 +/- 0.15 to 0.428 +/- 0.012, 1.075 +/- 0.047 and 73.68 +/- 1.84, respectively. The intracellular Rho123 retention was decreased from 711.9 +/- 63.6 to 347.8 +/- 60.6, indicating up-regulation of P-gp function (P<0.05). Pretreatment of K562 cells with 2.0 microg/ml TTD for 24 hours and then incubated for another 24 h with doxorubicin, the expressions of mdr1 mRNA, NF-kappa B mRNA, P-gp and up-regulation of P-gp function induced by doxorubicin were prevented in K562 cells (0.148 +/- 0.006, 0.627 +/- 0.098, 7.18 +/- 0.38 and 799.7 +/- 45.8, respectively P<0.05). But 0.5 microg/ml and 1.0 microg/ml TTD had little effect. CONCLUSIONS: TTD inhibits the expression of mdr1 mRNA, P-gp and up-regulated P-gp function induced by doxorubicin in a dose dependent manner. The mechanism of this effect may be down-regulation of NF-kappa B by TTD.

ATR alterations in Hodgkin's lymphoma.

Hodgkin's lymphoma (HL) is characterized by the presence of neoplastic Hodgkin and Reed-Sternberg cells (HRSC) in a background of inflammatory cells. Free radicals and oxidative stress generated in the inflammatory lesions could cause DNA damage, thus providing a basis for lymphomagenesis. Ataxia-telangiectasia mutated (ATM) and Rad3-related (ATR) genes are responsive genes for DNA damage, therefore the potential involvement of the ATR gene in HL pathogenesis was examined in 8 HL cell lines and 7 clinical cases. ATR alterations were detected in 6 out of 8 HL lines. Most aberrant transcripts observed were heterozygous deletions, which may have resulted from aberrant splicing. ATR aberrant transcripts were also detected in 3 out of 7 clinical cases. Three alterations, del exon 4, deletion exon 29-34 and insertion of 137 bp in exon 46/47 were commonly observed in both cell lines and clinical samples. HL cells with ATR alterations except del exon 4 showed a delay/abrogation in repair for DNA double-strand breaks (DSBs) and single-strand break (SSB) as well as exhibiting a defect in p53 accumulation. These findings suggested the role of ATR gene alterations in HL lymphomagenesis.

Alterations in ATR in nasal NK/T-cell lymphoma and chronic active Epstein-Barr virus infection.

Nasal natural killer (NK)/T-cell lymphoma (NKTCL) and chronic active Epstein-Barr virus infection (CAEBV) are relatively frequent, especially in Asia, and are poor in prognosis. Both diseases are proliferative diseases of NK/T cells that show highly complicated karyotypes, suggesting the involvement of chromosomal instability. ATR is an important gene for DNA damage response and chromosomal stability. To evaluate the role of ATR gene alterations in the pathogenesis of NKTCL and CAEBV, the whole coding region of the ATR gene was examined in cell lines derived from NKTCL and CAEBV, as well as tumor samples from patients. ATR alterations were detected in two of eight NKTCL and in one of three CAEBV lines. Most aberrant transcripts observed were deletions resulting from aberrant splicing. ATR alterations were also detected in four of 10 NKTCL clinical samples. Both NKTCL and CAEBV cell lines with ATR alterations showed a delay or abrogation in repair of ionizing radiation-induced DNA double-strand breaks and ultraviolet-induced DNA single-strand breaks, and both exhibited a defect in p53 accumulation. These findings show that alterations in the ATR gene result in an abnormal response to DNA double-strand break and single-strand break repair, suggesting a role for ATR gene alterations in NKTCL lymphomagenesis.

[Molecular cloning and expression of human PDGF-B chain peptide gene and its effect on cat corneal endothelial cell proliferation in vitro].

OBJECTIVE: To construct pET-PDGF-B plasmid with over expression of PDGF and investigate its effects on cat corneal endothelial cells proliferation in vitro. METHODS: Gene rearrangement technique was used to construct the prokaryotic vector with insertion of pET-PDGF-B. The recombinant PDGF-B was obtained from E. coli BL21 (DE3). The effects of recombinant PDGF-B on proliferation and morphologic changes of cultured cat corneal endothelial cells were assayed by modified tertrozalium salt (MTT), inverted phase contrast microscope and transmission electron microscope. RESULTS: PDGF-B peptide gene was inserted into prokaryotic expression vector pET-28a (+), which was confirmed by sequence analysis; a 27,000 protein band was demonstrated as pET-PDGF-B from extraction of E. coli BL21 (DE3) using western blot; MTT assay showed PDGF-BB promoted the proliferation of cat corneal endothelial cells. CONCLUSIONS: A constructed pET-PDGF-B plasmid vector over expression of PDGF is produced. Recombinant PDGF-BB promotes cultured cat corneal endothelial cells proliferation.