[Association study between the KCNE family gene polymorphisms of potassium channel gene and the susceptibility of atrial fibrillation].

Objective: To investigate the relationship between KCNE family gene polymorphisms of potassium channel gene and the susceptibility of atrial fibrillation (AF). Methods: In the case-control study, a total of 648 subjects were studied, of which 338 patients with atrial fibrillation were selected from the Department of Cardiovascular Medicine, Putuo Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January 2019 to December 2019, and 310 healthy people were selected from the physical examination population during the same period. DNA sequencing technology and polymerase chain reaction (PCR) were used to detect the genotype and allele frequency of rs1805127 of KCNE1, rs9984281 of KCNE2, rs9516, rs626930 of KCNE3 and rs12621643 of KCNE4. Results: The ages of subjects in atrial fibrillation group and control group were (69±13) and (73±8) years, respectively (P=0.077). Men subjects accounted for 57.70% (195 men) and 40.00% (124 men) in the two groups, respectively (P=0.092). The distribution frequencies of the allele C at rs1805127 of gene KCNE1, the allele A at rs9984281 of gene KCNE2 and the allele G at rs12621643 of gene KCNE4 were significantly different between groups (P<0.05). After adjustment for sex, smoking, hypertension, cardiac insufficiency and other factors, it was found that the increase in the frequency of the above three loci would increase the risk of atrial fibrillation (rs1805127 OR=7.064, 95%CI:1.559-31.997; rs9984281 OR=4.210, 95%CI:1.118-15.850; rs12621643 OR=2.679, 95%CI:1.025-6.998). Conclusion: The rs1805127 of KCNE1, the rs9984281 of KCNE2,the rs12621643 of KCNE4 were significantly associated with the susceptibility to atrial fibrillation.

[A multicenter randomized prospective study of concurrent chemoradiation with 60 Gy versus 50 Gy for inoperable esophageal squamous cell carcinoma].

Objective: To determine whether 60 Gy is superior to standard 50 Gy for definitive concurrent chemoradiation(CCRT) in esophageal squamous cell carcinoma (ESCC) using modern radiation technology in a phase Ⅲ prospective randomized trial. Methods: From April 2013 to May 2017, 331 patients from 22 hospitals who were pathologically confirmed with stage ⅢA-ⅣA ESCC were randomized to 60 Gy or 50 Gy with random number table. Total of 305 patients were analyzed, including 152 in 60 Gy group and 153 in 50 Gy group. The median age was 63 years, 242(79.3%) males and 63(20.7%) females. The median length of primary tumor was 5.6 cm. The clinical characteristics between two groups were comparable. All patients were delivered 2 Gy per fraction, 5 fractions per week. Concurrent weekly chemotherapy with docetaxel (25 mg/m(2)) and cisplatin (25 mg/m(2)) and 2 cycles consolidation chemotherapy with docetaxel (70 mg/m(2)) and cisplatin (25 mg/m(2), d1-3) were administrated. The primary endpoint was local/regional progression-free survival (LRPFS). The data were compared with Pearson chi-square test or Fisher's exact test. Results: At a median follow-up of 27.3 months, the disease progression rate was 37.5% (57/152), 43.8% (67/153) in the high and standard-dose group, respectively (χ(2)=1.251, P=0.263). The 1, 2, 3-year LRPFS rate was 75.4%, 56.8%, 52.1% and 74.2%, 58.4%, 50.1%, respectively (HR: 0.95, 95%CI: 0.69-1.31, P=0.761). The 1, 2, 3-year overall survival rate was 84.1%, 64.8%, 54.1% and 85.4%, 62.9%, 54.0%, respectively (HR: 0.98, 95%CI: 0.71-1.38, P=0.927). The 1, 2, 3-year progression-free survival rate was 70.8%, 54.2%, 48.5% and 65.5%, 51.9%, 45.1%, respectively (HR: 0.93, 95%CI: 0.68-1.26, P=0.621). The incidence rates in toxicities between the two groups were similar except for higher rate of severe pneumonitis in high dose group (χ(2)=11.596, P=0.021). Conclusions: The efficacy in disease control is similar between 60 Gy and 50 Gy using modern radiation technology concurrent with chemotherapy for ESCC. The 50 Gy should be recommended as the regular radiation dose with CCRT for ESCC.

Surface premelting/recrystallization governing the collapse of open-cell nanoporous Cu via thermal annealing.

We systematically investigate the collapse of a set of open-cell nanoporous Cu (np-Cu) materials with the same porosity and shape but different specific surface areas, during thermal annealing, by performing large-scale molecular dynamics simulations. Two mechanisms govern the collapse of np-Cu. One is direct surface premelting, facilitating the collapse of np-Cu, when the specific surface area is less than a critical value (∼2.38 nm-1). The other is recrystallization followed by surface premelting, accelerating the sloughing of ligaments and the annihilation of voids, when the critical specific surface area is exceeded. Surface premelting results from surface reconstruction by prompting localized "disordering" and "chaos" on the surface, and the melting temperature reduces linearly with the increase of the specific surface area. Recrystallization is followed by surface premelting as the melting temperature is below the supercooling point, where a liquid is unstable and instantaneously recrystallizes.

Shock wave propagation, plasticity, and void collapse in open-cell nanoporous Ta.

We systematically investigate the wave propagation, plasticity and void collapse, as well as the effects of porosity, specific surface area and impact velocity, in a set of open-cell nanoporous Ta, during shock compression, via performing large-scale non-equilibrium molecular dynamics simulations. The shock wave propagation presents an impedance, sensitive to porosity, but not to specific surface area. Such surprising phenomena are due to the similar sensitivities in density and stress variations to porosity or specific surface area. Upon impact, shock front shapes change from ramped to steep ones, with increasing porosity, specific surface area or impact velocity, owing to the transition from the heterogeneous to homogeneous plasticity along transverse directions. This transition of plasticity arises by (i) the strong impedance on large deformation bands as porosity increases; and (ii) the transition from deformation twinning to dislocation slips, and to amorphization, as the specific surface area or impact velocity increases. Shock-induced plasticity, including their nucleation, growth and interactions, also facilitates the collapse of voids.

Media influence on drive for thinness, body satisfaction, and eating attitudes among young women in Hong Kong and China.

The present study examined the impact of thin-ideal media exposure on Chinese women's drive for thinness, attitudes towards body shape, and eating attitude. Women were assigned to one of two video conditions, which portrayed the thin-ideal (experimental) or was neutral (control group), in terms of content. A total of 83 young women from Hong Kong (N = 38) and Shanghai (N = 45), aged between 18 and 25 years (Mage = 22.7) participated in the study. A significant interaction was observed between the experimental video condition and location. Hong Kong women in the experimental group experienced greater levels of body dissatisfaction than Shanghai women exposed to the same condition. Exposure to thin-ideal media produced an increase in drive for thinness, body dissatisfaction and problematic eating attitudes regardless of location, with a greater immediate impact shown in Hong Kong women.

[Clinicopathologic features of hepatocellular carcinoma patients surviving more than 10 years after radical hepatectomy].

Objective: To clarify the clinicopathologic features of hepatocellular carcinoma (HCC) patients survived more than 10 years after radical hepatectomy. Methods: Two hundreds and fifty-two patients who underwent curative resection for HCC between January 1999 and March 2006 at Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Qingdao University were included.There were 217 male cases and 35 female cases aging from 17 to 82 years with median age of (53.8±10.5)years. Followed by March 31 2016, clinicopathologic factors in 10-year survivors and patients who died within 10 years were compared by χ(2) test, Kaplan-Meier survival analysis and Cox proportional hazards model and the prognostic factors affecting survival were identified. Results: All patients were followed-up for 4.0 to 205.7 months with median time of 53.4 months. The 10-year overall survival rate was 26%, there were 62 cases(26.2%) who survived for more than 10 years after initial hepatectomy. In survival >10-year group, the paitents with ALT<40 U/L, gamma-glutamyl transpeptidase<64 U/L, albumin≥35 g/L, without liver cirrhosis and portal hypertension, Child-Pugh grade A, no blood transfusion, AFP≤20 µg/L, tumor size ≤5.0 cm, single tumor, high differentiation, TNM stage Ⅰ and TACE negative after resection were more than the patients in survival <10-year group (P<0.05). In multivariate analysis, Child-Pugh grade A, the tumor size ≤5.0 cm and TACE negative after resection were favorable independent factors associated with 10-year survival (P<0.05). Conclusion: Based on the results of the study, Child-Pugh grade A, tumor size ≤5.0 cm and TACE negative after resection at initial hepatectomy might be biologically favorable conditions for patients surviving more than 10 years.

[Expression and significance of microtubule associated protein 1 light chain 3B, p62 and Beclin1 in lesion tissues of oral lichen planus patients].

Objective: To explore the expression of autophagy related factors microtubule associated protein 1 light chain 3B (LC3B), p62, autophagy key factor Beclin1 in oral lichen planus (OLP) tissues and their relationships with the clinicopathological characteristics of OLP, investigating the function and significance of autophagy in pathogenesis of OLP. Methods: Forty-one lesion tissues (OLP group, twenty-one cases of erosive OLP and twenty cases of non-erosive OLP) were selected from OLP patients visiting the Department of Periodontal and Oral Medicine, School and Hospital of Stomatology, Guizhou Medical University from October 2017 to December 2019. Fifteen cases of normal oral mucosal tissues (control group) were collected from oral and maxillofacial surgery at The Affiliated Stomatology Hospital of Guizhou Medical University during the same period. Protein and mRNA expression levels of LC3B, p62 and Beclin1 were detected by immunohistochemistry (IHC) and real-time quantitative PCR (RT-qPCR) in OLP lesions respectively. The protein expression levels of LC3B, p62, Beclin1 and ratio of LC3B-Ⅱ/LC3B-Ⅰ in sixteen cases (eight cases of erosive OLP and eight cases of non-erosive OLP) from the OLP group were detected by Western blotting (WB). The potential relationship between LC3B, p62, Beclin1, LC3B-Ⅱ/LC3B-Ⅰ ratio and clinical features of OLP were analyzed. Results: IHC results showed that the positive expression rates of LC3B and p62 proteins in OLP lesion tissues [LC3B: 68% (28/41); p62: 59% (24/41)] were higher than those in the control group [LC3B: 5/15; p62: 3/15] (LC3B: χ2=5.55, P=0.019; p62: χ2=5.55, P=0.015). The positive expression rates of LC3B and p62 proteins in the erosive OLP group [LC3B: 86% (18/21); p62: 76% (16/21)] were higher than those in the non-erosive OLP group [LC3B: 50% (10/20); p62: 40% (8/20)] (LC3B: χ2=4.50, P=0.034; p62:χ2=5.53, P=0.019). The positive expression rate of Beclin1 protein in the OLP lesions[20% (8/41)] was lower than that in the control group (7/15) (χ2=4.13, P=0.042), but was not statistically different between the two types of OLP (P>0.05). The RT-qPCR results showed that the mRNA expression levels of LC3B and p62 in OLP lesions [LC3B: 2.78 (1.59, 6.15); p62: 4.30 (2.34, 6.29)] were higher than those in the control group [LC3B: 1.05 (0.88, 1.21); p62: 1.12 (0.89, 1.36)] (LC3B: Z=-4.56, P<0.001; p62: Z=-4.78, P<0.001), and the mRNA expression levels of LC3B and p62 in the erosive OLP group were higher than those in the non-erosive OLP group (LC3B: Z=-2.87, P=0.004; p62: Z=-2.95, P=0.003). The mRNA expression level of Beclin1 in OLP tissues was lower than that in the control group (Z=-2.43, P=0.015), but the difference was not statistically significant between the two types of OLP (P>0.05). WB results showed that the LC3B-Ⅱ/LC3B-Ⅰ ratio was higher in the OLP lesions than that in the control group (t=-2.45, P=0.021), and the LC3B-Ⅱ/LC3B-Ⅰ ratio was higher in the non-erosive OLP group than in the erosive OLP group (t=-2.38, P=0.032). Spearman's correlation analysis showed that the ratio was negatively correlated with the clinical staging and the degree of basal cell liquefaction in OLP (clinical staging: r=-0.57, P=0.021; basal cell liquefaction: r=-0.54, P=0.032), but not with the disease duration and the degree of lymphocytic infiltration (P>0.05). Conclusions: Autophagy related factors LC3B, p62 and Beclin1 may play a role in the formation and progression of OLP lesions. The autophagy level was relatively lack in erosive OLP compared to non-erosive OLP, contributing to the increased local lesion destruction in erosive OLP. Abnormal cellular autophagy may play an important role in the formation of OLP lesions.

[Effects of interleukin-35 on the balance of helper T cell 17/regulatory T cell in peripheral blood of patients with oral lichen planus].

Objective: To investigate the effects of exogenous interleukin (IL)-35 on the balance of helper T cell 17 (Th17) and regulatory T cell (Treg) in peripheral blood of patients with oral lichen planus (OLP). Methods: Totally 12 peripheral blood samples of OLP patients (OLP group, one male and 11 female, 26-68 years old; four cases of reticular OLP and eight cases of erosive OLP) were collected from patients of Department of Oral Mucosal Specialist of the Affiliated Hospital of Guizhou Medical University from October to December 2016. During the same period, thirteen normal peripheral blood samples were collected from the Physical Examination Center of the Affiliated Hospital of Guizhou Medical University (normal control group, one male and 12 female, 20-68 years old). The peripheral blood mononuclear cells (PBMC) were extracted in sterile condition and CD4+ T cells were sorted by flow cytometry (FCM). Quantitative real-time PCR (qPCR) technique was used to detect the mRNA expression levels of retinoid-related orphan nuclear γt (RORγt) and forkhead box3 (Foxp3). The CD4+ T cells were divided into experimental group and control group. The CD4+ T cells of experimental group were cultured in vitro by adding rhIL-35, and the CD4+ T cells of control group were cultured with the same volume of phosphate buffered saline (PBS). After the completion of the culture, the cells were collected. The expression levels of the same factors were detected by qPCR. Results: The expression [M(Q(25), Q(75))] of Foxp3 [0.15 (0.09, 0.30)] and RORγt mRNA [1.04 (0.45, 2.15)] in the CD4+ T cells of OLP were significantly higher than those in normal control group [0.04 (0.02, 0.06), 0.10 (0.05, 0.11)] (Z=-4.134, P<0.01; Z=-3.699, P<0.01). The ratio of ROR γt/Foxp3 mRNA in OLP group [6.22(3.67, 15.34)] was higher than that in normal control group [2.50 (1.24, 5.23)] (Z=-2.665, P=0.007). In the CD4+ T cells of OLP patients, the expression of Foxp3 mRNA in the experiment group [0.40 (0.21, 1.22)] was higher than that in the control group [0.15 (0.11, 0.26)](Z=-2.510, P=0.012), and the expression of ROR γt mRNA between two groups showed no significant difference (P>0.05). The ROR γt/Foxp3 mRNA ratio [3.44 (1.55, 8.16)] of the experiment group was lower than that in the control group [6.22 (4.43, 12.21)] (Z=-2.746, P=0.006). Conclusions: There was a Th17/Treg imbalance with predominated by Th17 cells in the peripheral blood of patients with OLP. Exogenous rhIL-35 had an immunomodulatory effect on the balance of Th17/Treg.

First-principles study for vacancy-induced magnetism in nonmagnetic ferroelectric BaTiO3.

The possibilities of vacancy-induced magnetism in perovskite BaTiO(3) are investigated by first-principles calculations. Calculated results show that both titanium and oxygen vacancies could induce magnetism, but the barium vacancy did not induce magnetism. New and interesting magnetic properties of half-metallic magnetism are found in BaTiO(3) induced by the Ti-vacancy. Based on the density of states and the spin charge density distribution of BaTiO(3), we discuss the different origins of magnetism induced by the partial spin-polarized O 2p states around Ti vacancies and the partially filled d-states Ti around the oxygen vacancies. The discrepancy between the magnetic moments in the cubic phase and the tetragonal phase is due to anisotropic spin polarization induced by structure distortions. Our calculations would enable exploring magneto-electric coupling in nonmagnetic ferroelectric oxides.

The practicalities of terminally ill patients signing their own DNR orders--a study in Taiwan.

OBJECTIVES: To investigate the current situation of completing the informed consent for do-not-resuscitate (DNR) orders among the competent patients with terminal illness and the ethical dilemmas related to it. PARTICIPANTS: This study enrolled 152 competent patients with terminal cancer, who were involved in the initial consultations for hospice care. ANALYSIS: Comparisons of means, analyses of variance, Student's t test, chi(2) test and multiple logistic regression models. RESULTS: After the consultations, 117 (77.0%) of the 152 patients provided informed consent for hospice care and DNR orders. These included 21 patients (17.9%) who signed the consent by themselves, and 96 (82.1%) whose consent sheet was signed only by family members. The reasons why patients were not involved in the discussions toward the consent (n = 82) included poor physical or psychological condition (44.9%), concerns of the consultant hospice team (37.2%), and the family's refusal (28.2%). On a multivariate analysis, patients' awareness of their poor prognosis (odds ratio = 4.07, 95% confidence interval = 2.05 to 8.07) and their understanding of hospice care (2.27, 1.33 to 3.89) were two independent factors (p < 0.01) that influenced their participation in the discussions or their personal signature in the informed consent. CONCLUSION: The family-oriented culture in Asian countries may violate the principles of the Patient Self-Determination Act and the requirements of the Hospice Care Law in Taiwan, which inevitably poses an ethical dilemma. Earlier truth-telling and continuing education of the public by hospice care workers will be helpful in solving such ethical dilemmas.

Hydroxyapatite/titania sol-gel coatings on titanium-zirconium alloy for biomedical applications.

A simple sol-gel method was developed for hydroxyapatite/titania (HA/TiO(2)) coatings on non-toxic titanium-zirconium (TiZr) alloy for biomedical applications. The HA/TiO(2)-coated TiZr alloy displayed excellent bioactivity when soaked in a simulated body fluid (SBF) for an appropriate period. Differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy-energy dispersive spectrometry were used to characterize the phase transformations and the surface structures and to assess the in vitro tests. The HA/TiO(2) layers were spin-coated on the surface of TiZr alloy at a speed of 3000rpm for 15s, followed by a heat treatment at 600 degrees C for 20min in an argon atmosphere sequentially. The TiO(2) layer exhibited a cracked surface and an anatase structure and the HA layer displayed a uniform dense structure. Both the TiO(2) and HA layers were 25microm thick, and the total thickness of the HA/TiO(2) coatings was 50microm. The TiZr alloy after the above HA/TiO(2) coatings displayed excellent bone-like apatite-forming ability when soaked in SBF and can be anticipated to be a promising load-bearing implant material.

Using wound bed preparation to heal a malignant fungating wound: a single case study.

Full healing was achieved within eight weeks in a malignant fungating wound using the principles of the TIME paradigm. This concept appears to provide a structured and systematic approach for managing such non-healing wounds.

Evaluation of the COBAS® TaqMan® system in patients with low hepatitis B virus DNA undetectable with PCR assay kit.

OBJECTIVE: We conducted a comparison of the diagnostic kit for quantification of hepatitis B virus DNA (PCR-fluorescence probing) and COBAS TaqMan automated nucleic acid extraction and real-time polymerase chain reaction (PCR) amplification systems. We tested their capacity to quantify and diagnose patients with chronic viral hepatitis B with low viral load < 1 x 103 IU/mL, in hope to provide further evidence for promoting the application of COBAS TaqMan as the diagnostic method for such patients. PATIENTS AND METHODS: Diagnostic kit and COBAS TaqMan system were tested on 100 patients diagnosed with chronic viral hepatitis B in our hospital and with a viral load lower than the detection limit of real-time extraction-quantification kit. These patients included 47 cases with chronic viral HBV, 53 cases of HBV-associated cirrhosis (11 cases were HBV-associated liver cancer with cirrhosis). COBAS TaqMan real-time quantification PCR with a sensitivity of 20 IU/ml was performed to test the reproducibility for the diagnosis result. RESULTS: The COBAS TaqMan real-time system quantified 76 cases out of 100 with a viral load higher than 20 IU/ml (detection rate, 76%). Among these patients, there were 33 cases of chronic viral HBV (without cirrhosis) (detection rate, 70.2%), 43 cases of cirrhosis (detection rate, 81.1%, including 28 cases of compensatory cirrhosis and 15 cases of decompensated cirrhosis), and 11 cases of liver cancer (detection rate, 81.2%). CONCLUSIONS: The COBAS TaqMan system has higher sensitivity than traditional real-time PCR detection kit, especially for HBV-related cirrhosis and liver cancer with low viral load. The limitation of real-time PCR should be taken into account during treatment monitoring and the alternative of COBAS TaqMan system should be promoted in patients with high risk of liver cirrhosis and cancer to avoid delayed diagnosis and improve clinical outcome.

Anatomy of a preferred target site for the bacterial insertion sequence IS903.

Like many transposons the bacterial insertion sequence IS903 was thought to insert randomly. However, using both genetic and statistical approaches, we have derived a target site for IS903 that is used 84% of the time. Computational and genetic analyses of multiple IS903 insertion sites predicted a preferred target consisting of a 21 bp palindromic pattern centered on the 9 bp target duplication generated during transposition. Here we show that targeting can be dissected into four components: the 5 bp flanking sequences, the most important sequences required for site-specific insertion; the 7 bp palindromic core within the target duplication; the dinucleotide pair at the transposon-target junction; and the local DNA context. Finally, using a substrate with multiple target sites we show that a target site is more likely found by a local bind-and-slide model and not by extended DNA tracking.

DNA-RNA chimeric hammerhead ribozyme to transforming growth factor-beta(1) mRNA inhibits the exaggerated growth of vascular smooth muscle cells from spontaneously hypertensive rats.

OBJECTIVE: The purpose of this study was to develop DNA-RNA chimeric hammerhead ribozyme against transforming growth factor-beta(1) (TGF-beta(1)) mRNA as a gene therapy agent for arterial proliferative diseases. METHODS: A 38-base hammerhead ribozyme against rat TGF-beta(1) mRNA, to produce cleavage at the GUC sequence at nucleotide 825 according to the secondary structure of rat TGF-beta(1) mRNA was designed. To enhance its stability, we synthesized a DNA-RNA chimeric ribozyme with two phosphorothioate linkages at the 3'-terminal. We also synthesized a mismatch ribozyme with single base change in the catalytic loop region as a control. These ribozymes were delivered into rat vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats by lipofectin-mediated transfection, and their biological effects were investigated. RESULTS: According to in vitro cleavage studies, the synthetic ribozyme can cleave the synthetic substrate RNA into two RNA fragments. Chimeric ribozyme significantly inhibited DNA synthesis in VSMC from SHR but not in cells from WKY rats. Mismatch ribozyme showed only a little effect on growth of VSMC from SHR. Chimeric ribozyme significantly inhibited proliferation of VSMC from SHR; in contrast, the proliferation of VSMC from WKY rats was significantly increased by this chimeric ribozyme. Mismatch ribozyme did not affect proliferation of VSMC from either rat strain. Chimeric hammerhead ribozyme to rat TGF-beta(1) dose-dependently inhibited TGF-beta(1) mRNA expression detected by reverse transcription and polymerase chain reaction analysis in VSMC from both rat strains. Chimeric hammerhead ribozyme to rat TGF-beta(1) also dose-dependently inhibited TGF-beta(1) protein production detected by Western blot analysis. CONCLUSIONS: The present results demonstrated that our designed DNA-RNA chimeric hammerhead ribozyme to TGF-beta(1) mRNA might be a useful gene therapy agent for hypertensive vascular diseases.

Abnormal regulation of transforming growth factor-beta receptors on vascular smooth muscle cells from spontaneously hypertensive rats by angiotensin II.

The effects of angiotensin II (Ang II) on the expression and characteristics of transforming growth factor-beta (TGF-beta) receptors on vascular smooth muscle cells (VSMC) from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) were investigated. TGF-beta-induced stimulation of DNA synthesis by VSMC from WKY rats was abolished with Ang II, whereas basal and TGF-beta-stimulated DNA synthesis by VSMC from SHR was increased with Ang II. Ang II stimulated DNA synthesis by VSMC from WKY rats in the presence but not in the absence of neutralizing antibody to TGF-beta1. Antibody to TGF-beta1 enhanced the stimulatory effect of Ang II on DNA synthesis by VSMC from SHR. Ang II increased the specific binding of TGF-beta to VSMC from WKY rats by increasing both the expression of the lower-affinity of TGF-beta receptors as well as the total number of TGF-beta binding sites. In contrast, VSMC from SHR showed a higher affinity and number of TGF-beta receptors in the absence of Ang II than did cells from WKY rats, and these parameters were not affected by Ang II. Ang II increased the expression of TGF-beta type I receptor mRNA in VSMC from WKY rats but had no effect of TGF-beta receptor type I or II mRNA in VSMC from SHR, which predominantly express the type II receptor. These results indicate that an increase in the expression of the TGF-beta type I receptor by Ang II may facilitate the ability of endogenous TGF-beta to counteract the stimulatory effect of Ang II on growth in VSMC from WKY rats, whereas endogenous TGF-beta induced by Ang II cannot counteract the growth-promoting action of Ang II in VSMC from SHR. The abnormal regulation of TGF-beta receptors by Ang II may be associated with the exaggerated growth of VSMC from SHR.

Hammerhead ribozyme targeting human platelet-derived growth factor A-chain mRNA inhibited the proliferation of human vascular smooth muscle cells.

Platelet-derived growth factor (PDGF) A-chain contributes to the pathogenesis of cardiovascular proliferative diseases, such as hypertensive vascular disease, atherosclerosis, and re-stenosis of an artery after angioplasty. To develop a ribozyme against human PDGF A-chain mRNA as a gene therapy for human arterial proliferative diseases, we designed and synthesized a 38-base hammerhead ribozyme to cleave human PDGF A-chain mRNA at the GUC sequence at nucleotide 591. In the presence of MgCl(2), synthetic hammerhead ribozyme to human PDGF A-chain mRNA cleaved the synthetic target RNA to two RNA fragments at a predicted size. Doses of 0.01-1.0 microM hammerhead ribozyme to human PDGF A-chain mRNA significantly inhibited angiotensin II (Ang II) and transforming growth factor (TGF)-beta(1)-induced DNA synthesis in vascular smooth muscle cells (VSMC) from human in a dose-dependent manner. One micromolor of hammerhead ribozyme to human PDGF A-chain mRNA significantly inhibited Ang II-induced PDGF A-chain mRNA and PDGF-AA protein expressions in VSMC from humans. These results indicate that the designed hammerhead ribozyme to human PDGF A-chain mRNA effectively inhibited growth of human VSMC by cleaving the PDGF A-chain mRNA and inhibiting the PDGF-AA protein expression in human VSMC. This suggests that the designed hammerhead ribozyme to PDGF A-chain mRNA is a feasible gene therapy for treating arterial proliferative diseases.