OBJECTIVETo assess the pathologic markers for evaluation of reversibility in pulmonary hypertension (PAH) related to congenital heart disease.

METHODSTwenty-eight patients with congenital heart disease complicated by PAH were subclassified into reversible pulmonary hypertension (RPAH) and irreversible pulmonary hypertension (IPAH), according to post-operative mean pulmonary artery pressure (MPAP). Pulmonary vascular lesion was analyzed according to Ruan's method. Mean medium thickness percent, mean medium area percent and pulmonary arteriolar density were measured by quantitative morphometry. Immunohistochemical study for transgelin and filamin A was carried out.

RESULTSAmongst the 28 cases studied, 24 were RPAH and 4 were IPAH. Of the 24 patients with RPAH, 13 (54.2%, 13/24) had pulmonary vascular lesion of grade 0, 9 (37.5%, 9/24) of grade 1 and 2 (8.3%, 2/24) of grade 2. Of the 4 patients with IPAH, 1 had lesion of grade 1, 1 of grade 2 and 2 of grade 3. Both preoperative and postoperative MPAP were higher in IPAH patients than that in RPAH patients[(53.3±23.4) mmHg versus (34.1±12.7) mmHg, P=0.020 and (35.0±8.8) mmHg versus (17.8±3.9) mmHg, P<0.01]. Compared to patients with pulmonary vascular lesion of grades 0 and 1, the preoperative MPAP in patients with grades 2 and 3 showed no significant difference, but the postoperative MPAP was higher (P<0.05 or 0.01). Compared to control group, mean medium thickness percent and mean medium area percent were significantly higher in RPAH and IPAH categories (12.0±3.5, 8.5±2.0 versus 5.7±1.0, P<0.01 and 55.8±11.1, 49.0±9.4 versus 34.0±5.5, P<0.01). Mean medium thickness percent was significantly higher in IPAP group than that in RPAH group (12.0±3.5 versus 8.5±2.0, P=0.001). Correlation analysis demonstrated that mean medium thickness percent and mean medium area percent had positive correlation with preoperative and postoperative MPAP. There was no correlation between grading of pulmonary vascular lesion and reversibility. Transgelin and filamin A had stronger staining in pulmonary vascular smooth muscle cells in IPAH than those in RPAH and controls(P<0.05).

CONCLUSIONSPathologic assessment of lung biopsy remains the gold standard for evaluation of the reversibility in PAH related to congenital heart disease. Mean medium thickness percent, mean medium area percent and immunoreactivity for transgelin and filamin A are useful parameters.

Biomarkers ; metabolism ; Biopsy ; Filamins ; metabolism ; Heart Diseases ; complications ; pathology ; Humans ; Hypertension, Pulmonary ; complications ; diagnosis ; pathology ; Lung ; pathology ; Microfilament Proteins ; metabolism ; Muscle Proteins ; metabolism

In resting platelets, the 17 ^th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563 ^rd phenylalanine (PHE ⁵⁶³-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
Filamins/metabolism* ; Platelet Glycoprotein GPIb-IX Complex/metabolism* ; Molecular Dynamics Simulation ; Ligands ; Protein Binding ; Blood Platelets/metabolism* ; von Willebrand Factor/metabolism*

Objective: To investigate the effect of adenovirus-mediated shRNA down-regulating phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on vinculin, filamin A, and cortactin in activated hepatic stellate cells (HSCs). Methods: Activated rats hepatic stellate cell line (HSC-T6) was cultured in vitro. Recombinant adenovirus Ad-shRNA/PTEN carrying PTEN targeted RNA interference sequence [short hairpin RNA (shRNA)] and empty control virus Ad-GFP were transfected into HSCs. The PTEN mRNA and protein expression of HSCs in each group were detected by real-time fluorescence quantitative PCR and Western blot. The expressional change of vinculin, filamin A and cortactin in HSCs of each group were detected by confocal laser scanning immunofluorescence microscope. Image-pro plus 6.0 software was used for image analysis and processing. The integrated optical density (IOD) of the fluorescence protein expression was measured. The experiment was divided into three groups: control group (DMEM instead of adenovirus solution in the adenovirus transfection step), Ad-GFP group (transfected with empty virus Ad-GFP only expressing green fluorescent protein), and Ad-shRNA/PTEN group (recombinant adenovirus Ad-shRNA/PTEN carrying shRNA targeting PTEN and expressing green fluorescent protein). One-way analysis of variance was used for comparison of mean value among the three groups, and LSD-test was used for comparison between the groups. Results: shRNA targeted PTEN was successfully transfected and the expression of PTEN mRNA and protein in HSC (P < 0.05) was significantly down-regulated. HSCs vinculin was mainly expressed in the cytoplasm. HSCs vinculin fluorescence IOD in the Ad-shRNA/PTEN group (19 758.83 ± 1 520.60) was higher than control (7 737.16 ± 279.93) and Ad-GFP group (7 725.50 ± 373.03) (P < 0.05), but there was no statistically significant difference between control group and Ad-GFP group (P > 0.05). There was no statistically significant difference in the fluorescence IOD of Filamin A among the three groups (P > 0.05), but the subcellular distribution of Filamin A among the three groups were changed. Filamin A in the Ad-shrNA /PTEN HSC group was mainly distributed in the cytoplasm. Filamin A HSC was mainly located in the nucleus.The filamin A HSC in the control group and Ad-GFP group was mainly located in the nucleus. The nucleocytoplasmic ratio of Filamin A in the AD-shrNA /PTEN group (0.60 ± 0.15) was significantly lower than control group (1.20 ± 0.15) and Ad-GFP group (1.08 ± 0.23), P < 0.05. but there was no statistically significant difference in filamin A nucleocytoplasmic ratio of HSC between the control group and the Ad-GFP group (P > 0.05). Cortactin HSCs in the three groups was mainly distributed in the cytoplasm. The cortactin fluorescence IOD of HSCs in the Ad-shRNA/PTEN group was significantly higher than control group (22 959.94 ± 1 710.42) and the Ad-GFP group (22 547.11 ± 1 588.72 ) (P < 0.05), while there was no statistically significant difference in the IOD of cortactin fluorescence in HSCs between the control group and the Ad-GFP group (P > 0.05). Conclusion: The down-regulation of PTEN expression raises the expression of microfilament-binding protein vinculin and cortactin, and changes the subcellular distribution of another microfilament binding protein filamin A, that is, translocation from nucleus to the cytoplasm in activated HSC in vitro.
Adenoviridae/metabolism* ; Animals ; Carrier Proteins ; Cell Proliferation ; Cortactin ; Filamins/genetics* ; Hepatic Stellate Cells/metabolism* ; PTEN Phosphohydrolase/metabolism* ; RNA, Small Interfering/genetics* ; Rats ; Vinculin/genetics*

OBJECTIVETo understand the role that esophageal cancer related gene-1 (ECRG-1) plays and to search for ECRG-1-interacting proteins.

METHODSA DNA fragment encoding the carboxy-terminus of ECRG-1 (amino acids 40 - 418) was inserted into pGBKT7-DNA-BD vector and fused in-frame to the DNA-binding domain of GAL4. Then, it was used as a bait to screen the human fetal liver cDNA library by yeast two-hybrid, with the cDNA fragment inserted into pACT2 vector and fused in-frame to the Gal4 activation domain. If ECRG-1 interacted with a protein encoded by a cDNA fragmant in the yeast, the transcription of reporter Gene could be activated. With the false positive clonies eliminated, the inserts in the positive plasmids were sequenced and compared to those in the GenBank.

RESULTSIn approximately 3 x 10(6) independent tansformants screened, 23 clonies exhibited the expression of reporter gene. After eliminating the false positive clonies, two cDNA fragments were obtained. DNA sequencing revealed that one encoded Miz-1 (Myc-interacting Zn finger protein-1), and another encoded FLNA (actin-binding protein-280), Miz-1, being a Zn finger protein, could be bound to p15 promotor and activated the transcription. FLNA, being an actin-binding protein took part in the TGF-beta pathway via interaction with Smad.

CONCLUSIONECRG-1 is able to be specifically bound to Miz-1 and FLNA in the yeast. It may play a role in the regulation of cell cycle via interaction with Miz-1 and FLNA.

Contractile Proteins ; metabolism ; DNA-Binding Proteins ; metabolism ; Escherichia coli Proteins ; metabolism ; physiology ; Filamins ; Gene Library ; Humans ; Kruppel-Like Transcription Factors ; Liver ; embryology ; physiology ; Membrane Proteins ; Microfilament Proteins ; metabolism ; Recombinant Fusion Proteins ; metabolism ; physiology ; Serine Proteases ; Transcription Factors ; Two-Hybrid System Techniques ; Yeasts ; genetics