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Jie Li

Publications and source records attributed to Jie Li.

At least 73 records · Page 4Linked to original sources
PubMed2006

[How brain-dead state affects the hepatic morphology and function of Ba-Ma mini pigs and its mechanism].

OBJECTIVE: To investigate the impact of brain death (BD) on the morphology and function of liver. METHODS: Fifteen Ba-ma minipigs were randomly divided into 3 equal groups: brain death group (Group B) made into BD models by increasing the intracranial pressure; breviscapine pretreatment group (Group P), with breviscapine 2.5 mg x kg(-1) given intravenous drip 1-2 hours after the successful establishment of BD model; and control group (Group C) undergoing operation similar to that in Group B but without increasing the intracranial pressure. 3, 6, 12, 18, and 24 hours after the initial confirmation of BD blood samples were collected from the superior vena cava to detect the serum alanine transaminase (ALT), aspartate transaminase (AST), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6, and a piece of liver tissues were collected to undergo light microscopy and electron microscopy, and immunohistochemistry to examine the expression of protein kinase (PKC)-alpha by RT-PCR. RESULTS: The levels of serum ALT and AST of Group B began to increase since 12 h after BD, and were both significantly higher than those of Group C 18 and 24 hours after BD (both P < 0.05). The levels of serum ALT and AST of Group P began to increase since 12 h after BD, and were both significantly lower than those of Group B (both P < 0.05). The levels of serum TNF-alpha, IL-1beta, and IL-6 of Group B and Group P began to increase gradually since 3 h after BD, however, those of Group B were all significantly higher than those of group P (all P < 0.05). PKC-alpha was only expressed in the plasma of a few normal liver cells. The PKC-alpha mRNA and protein levels of Groups B and P began to increase since 6 h after BD, however, those of Group B were all significantly higher than those of Group P (all P < 0.05). Light and electron microscopy showed that only mild edema of liver cells was seen in Group P, and since 12 h after BD swelling of mitochondria, edema of liver cells, etc. were seen in Group B, and the morphologic damages were more severe in Group B. CONCLUSION: Brain death evokes hepatic functional and morphological injuries. PKC-alpha may involve in the mechanism. Breviscapine inhibits the activation of PKC-alpha, thus reducing the damage in liver.

Alanine Transaminase↗
PubMed2006

Induction of primary human T cell responses against hepatitis C virus-derived antigens NS3 or core by autologous dendritic cells expressing hepatitis C virus antigens: potential for vaccine and immunotherapy.

Hepatitis C virus (HCV)-specific T cell responses have been suggested to play significant role in viral clearance. Dendritic cells (DCs) are professional APCs that play a major role in priming, initiating, and sustaining strong T cell responses against pathogen-derived Ags. DCs also have inherent capabilities of priming naive T cells against given Ags. Recombinant adenoviral vectors containing HCV-derived Core and NS3 genes were used to endogenously express HCV Core and NS3 proteins in human DCs. These HCV Ags expressing DCs were used to prime and stimulate autologous T cells obtained from uninfected healthy donors. The DCs expressing HCV Core or NS3 Ags were able to stimulate T cells to produce various cytokines and proliferate in HCV Ag-dependent manner. Evidence of both CD4(+) and CD8(+) T cell responses against HCV Core and NS3 generated in vitro were obtained by flow cytometry and Ab blocking experiments. Further, in secondary assays, the T cells primed in vitro exhibited HCV Ag-specific proliferative responses against recombinant protein Ags and also against immunodominant permissive peptide epitopes from HCV Ags. In summary, we demonstrate that the dendritic cells expressing HCV Ags are able to prime the Ag-specific T cells from uninfected healthy individuals in vitro. These studies have implications in designing cellular vaccines, T cell adoptive transfer therapy or vaccine candidates for HCV infection in both prophylactic and therapeutic settings.

Amino Acid Sequence↗
PubMed2006

Proteomic analysis of hemangioblastoma cyst fluid.

OBJECTIVE: Hemangioblastomas are benign CNS tumors that occur sporadically or in patients with von Hippel-Lindau (VHL) disease. These tumors are characteristically associated with formation of intra- or peritumoral cysts. Hemangioblastoma cyst formation is a major cause of morbidity and mortality with these tumors. While peritumoral cysts have been suggested to result from vascular leakage, the mechanism of intratumoral cyst formation is not understood. METHODS: To elucidate the origin of intratumoral hemangioblastoma cyst fluid, we characterized its biochemical composition by two-dimensional (2D) proteomic profiling followed by sequencing of several proteins. The proteomic pattern of intratumoral cyst fluid was furthermore compared to the proteomic pattern of serum, hemangioblastoma tumor tissue, and hemangioblastoma peritumoral cyst fluid. RESULTS: We show that proteomic patterns of intra- and peritumoral cyst fluid are identical Both are highly similar to serum and not to tumor. CONCLUSIONS: Intratumoral hemangioblastoma cyst fluid originates from serum. Cyst formation associated with hemangioblastoma, whether peri- or intratumoral, is a consequence of vascular leakage. Anti-VEGF therapy may effectively control hemangioblastoma cyst formation.

Biomarkers, Tumor↗
PubMed2006

Glutathione S-transferases as antioxidant enzymes: small cell lung cancer (H69) cells transfected with hGSTA1 resist doxorubicin-induced apoptosis.

It has been suggested that the alpha-class glutathione S-transferases (GSTs) protect various cell types from oxidative stress and lipid peroxidation (LPO). In order to examine the protective role of alpha-class GST isozyme hGSTA1-1 against doxorubicin (DOX)-induced lipid peroxidation, cytotoxicity, and apoptosis, human small cell lung cancer (SCLC) H69 cells were stably transfected with hGSTA1. Immunological and biochemical characterization of hGSTA1-transfected cells revealed the expression of functionally active hGSTA1-1 localized near the cellular plasma membranes. hGSTA1-transfected cells acquired significantly increased resistance to the DOX-induced cytotoxicity by suppressing lipid peroxidation levels in these cells. Overexpression of hGSTA1-1 in cells inhibited DOX-mediated depletion of GSH and higher GSH levels were found in DOX-treated hGSTA1-transfected cells as compared with empty vector-transfected controls. hGSTA1-1 overexpression also provided protection to cells from DOX-induced apoptosis by inhibiting phosphorylation of c-Jun-N-terminal kinases (JNK), caspase-3 activation, and by preserving the levels of anti-apoptotic protein Bcl-2. These results are consistent with the idea that the alpha-class GSTs provide protection against oxidative stress by attenuating lipid peroxidation and these enzymes can modulate signaling for apoptosis.

Antioxidants↗
PubMed2006

Enhancement of DNA vaccine potency by sandwiching antigen-coding gene between secondary lymphoid tissue chemokine (SLC) and IgG Fc fragment genes.

DNA vaccine has become an attractive approach for generating antigen-specific immunity. Targeting antigens to FcRs for IgG (FcgammaRs) on dendritic cells (DCs) has been demonstrated to enhance antigen presentation. Secondary lymphoid tissue chemokine (SLC) has been shown to increase immune responses not only by promoting coclustering of T cells and DCs in the lymph nodes and spleen but also by regulating their immunogenic potential for the induction of T cell responses. In this study, using HPV 16 E7 as a model antigen, we constructed a chemotactic-antigen plasmid DNA vaccine (pSLC-E7-Fc) by linking SLC and Fc gene sequences to each end of E7 and evaluated its potency of eliciting specific immune response. We found that immunization with pSLC-E7-Fc generated much stronger E7-specific lymphocyte proliferative and cytotoxic T lymphocyte (CTL) responses than control DNA. All the mice receiving pSLC-E7-Fc prophylactic vaccination remained tumor free upon subcutaneous inoculation of TC-1 cells, while those given control DNA all developed tumors. These tumor-free mice were also protected against TC-1 rechallenge. Complete tumor regression with long-term survival occurred in 72% of mice given pSLC-E7-Fc as therapeutic vaccination. In experimental lung metastasis model wherein TC-1 cells were intravenously injected, therapeutic vaccination with pSLC-E7-Fc significantly reduced the number of tumor nodules in the lung. In vivo depletion with antibodies against CD4+or CD8+ T cells both resulted in complete abrogation of the pSLC-E7-Fc-induced immunotherapeutic effect. Our data indicate that the DNA vaccine constructed by the fusion of SLC and IgG Fc fragment genes to antigen-coding gene is an effective approach to induce potent anti-tumor immune response via both CD4+ and CD8+ T cells dependent pathways.

Animals↗
PubMed2006

An experimental study on the repair of full skin loss of nude mice with composite graft of epidermal stem cells.

This study is to constitute a composite skin substitute with epidermal stem cells (ESCs) and fibroblasts on collagen sponge. ESCs were selected by rapid attachment to collagen IV for 10 min. Collagen was extracted from rat's tail. The matrix lattice was fabricated by freeze-dryer and cross-linked with glutaraldehyde. Fibroblasts were inoculated on collagen sponge and cultured for 1 week prior to inoculation of ESCs. Having cultured for 2 weeks in submerged culture, the bioengineered tissue was raised to the air-liquid interface and cultured for 2 weeks. The artificial skin was then grafted onto full skin loss wounds of nude mice. Collagen sponge membrane lacking cell inoculation and an artificial skin with epidermal cells (ECs) and fibroblasts were used as controls. The wounds were observed daily. Tissue samples were harvested and examined by means of histology, immunohistochemistry and electron microscopy. The wounds in the test group healed at a significantly faster rate than controls, with good skin appearance and minimal scar formation. The control group showed delayed wound healing and intensive wound contraction as compared to the test group. Thus the skin substitute with ESCs seemed to be a good equivalent.

Animals↗
PubMed2006

Hemangioblastomas share protein expression with embryonal hemangioblast progenitor cell.

Hemangioblastomas are central nervous system (CNS) tumors of unknown histogenesis, which can occur sporadically or in von Hippel-Lindau disease. Hemangioblastomas are composed of neoplastic "stromal" cells of unknown origin, accompanied by intensive reactive angiogenesis. Failure to specify the cytologic origin of the stromal cell has precluded the development of nonsurgical therapies and limits understanding of its basic biology. We report that the stromal cells express proteins (Scl, brachyury, Csf-1R, Gata-1, Flk-1, and Tie-2) that characterize embryonic progenitor cells with hemangioblastic differentiation potential and conclude that embryonic progenitors with hemangioblast potential represent a possible cytologic equivalent of the stromal cell. We also identified a new autocrine/paracrine stimulatory loop between the receptor Tie-2 and the hypoxia-inducible factor target Ang-1, which, combined with previous observations, suggests that a variety of autocrine loops may be initiated in hemangioblastomas, depending on the differentiation status of the tumor cells and the extent of HIF downstream activation. Finally, the consistent identification of Scl in the stromal cells may help explain the unique and characteristic topographical distribution of hemangioblastomas within the CNS.

Angiopoietin-1↗
PubMed2006

Ultralow-volume fraction collection from NanoLC columns for mass spectrometric analysis of protein phosphorylation and glycosylation.

An ultralow volume fraction collection system referred to as nano fraction analysis chip technology (nanoFACT) is reported. The system collects 25-2500-nL fractions from 75-microm nanoLC columns into pipet tips at a user-defined, timed interval, typically one fraction every 15-120 s. Following collection, the fractions in the tip dry down naturally on their own in such a way as to create a concentrated band at the very end of the interior of the pipet tip. The fractions are then reconstituted directly in the pipet tips in approximately 250 nL of solvent prior to analysis. Because the chromatography and reconstitution solvent are independent, the reconstitution solvent can be selected to maximize ionization efficiency without compromising chromatography. In the infusion analysis of the nanoLC fractions, a low-flow electrospray chip is used which consists of 400 nozzles, each with an inner diameter of 2.5 microm and yielding flow rates of approximately 20 nL/min. Therefore, when reconstituted in 250 nL, each nanoLC fraction can be analyzed for over 10 min. This increase in analysis time allows for signal averaging, resulting in higher data quality, collision energy optimization, slower scanning techniques to be used, such as neutral loss and precursor ion scanning, higher resolution scans on FTMS instruments, and improved peptide quantitation. Furthermore, the nanoLC fractions could be archived in the pipet tips for analysis at a later date. Here, the advantages of nanoFACT are shown for phosphorylation analysis using bovine fetuin and glycosylation analysis using bovine ribonuclease B (RNase B). In the phosphorylation analysis, a comparison between conventional nanoLC and a nanoFACT analysis was performed. An MS/MS spectrum of a triply phosphorylated peptide, 313-HTFSGVApSVEpSpSSGEAFHVGK-333 could only be obtained using nanoFACT, not with nanoLC. Furthermore, spectral quality for the nanoFACT analysis was significantly improved over nanoLC. This was determined by comparing the number of diagnostic ions between the nanoFACT and nanoLC spectra, and it was found that the nanoFACT spectra contained a 19% or greater number of diagnostic ions for nonphosphorylated peptides and 55% or greater for phosphorylated peptides. For the glycosylation analysis, the glycosylation site of RNase B was fully characterized using 100 fmol of tryptic digest on a three-dimensional ion trap mass spectrometer.

Amino Acid Sequence↗
PubMed2006

A single transition state serves two mechanisms. The branching ratio for CH2O*- + CH3Cl on improved potential energy surfaces.

The reaction of formaldehyde radical anion with methyl chloride, CH2O*- + CH3Cl, is an example in which a single transition state leads to two products: substitution at carbon (Sub(C), CH3CH2O* + Cl-) and electron transfer (ET, CH2O + CH3* + Cl-). The branching ratio for this reaction has been studied by ab initio molecular dynamics (AIMD). The energies of transition states and intermediates were computed at a variety of levels of theory and compared to accurate energetics calculated by the G3 and CBS-QB3 methods. A bond additivity correction has been constructed to improve the Hartree-Fock potential energy surface (BAC-UHF). A satisfactory balance between good energetics and affordable AIMD calculations can be achieved with BH&HLYP/6-31G(d) and BAC-UHF/6-31G(d) calculations. Approximately 200 ab initio classical trajectories were calculated for each level of theory with initial conditions sampled from a thermal distribution at 298 K at the transition state. Three types of trajectories were distinguished: trajectories that go directly to ET product, trajectories that go to Sub(C) product, and trajectories that initially go into the Sub(C) valley and then dissociate to ET products. The BH&HLYP/6-31G(d) calculations overestimate the number of nonreactive and direct ET trajectories because the transition state is too early. For the BH&HLYP and BAC-UHF methods, about one-third of the trajectories that initially go into the Sub(C) valley dissociate to ET products, compared to just over half with UHF/6-31G(d) in the earlier study. This difference can be attributed to a better value for the calculated energy release from the initial transition state and to an improved Sub(C) --> ET barrier height with the BH&HLYP and BAC-UHF methods.

Journal Article↗
PubMed2006

A computational exploration of some transnitrosation and thiolation reactions involving CH3SNO, CH3ONO and CH3NHNO.

Nitric oxide (NO) is a biologically active species and its carrier molecules RXNO (X = S, O, NH) have drawn significant attention recently. In the present work, the CBS-QB3 level of theory was used to study the transnitrosation and thiolation reaction between MeXNO (X = S, O, and NH) molecules and three reactive forms of the methanethiol: the neutral molecule, MeSH, the anion, MeS-, and the radical, MeS . The transnitrosation and thiolation reactions between MeXNO and MeSH have the highest barriers, both with and without a molecule of water assisting. Reactions with MeS- proceed with much lower barriers, while reactions with radical MeS have the lowest barriers. Comparing the reactions of MeXNO (X = S, O, NH), both transnitrosation and thiolation are more favorable for X = S than X = O or NH.

Hydrogen Bonding↗
PubMed2006

Preparation of novel saw-toothed and riblike alpha-Si3N4 whiskers.

alpha-Si(3)N(4) whiskers with novel saw-toothed and riblike structures have been synthesized in a high yield by a carbothermal reduction and nitridation route. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). The results show that the saw-toothed whiskers with one smooth surface and another toothlike surface have lengths about several tens of microns and widths in the range of 600-1200 nm. The riblike whiskers are composed of Si(3)N(4) rod-arrays, which grow closely packed perpendicular to the central axial whiskers with uniform diameter and length. The growth mechanism of the products can be considered as a combination of VS mechanism and secondary epitaxial nucleation process. The photoluminescence (PL) spectrum of the whiskers shows a strong blue light emission peak at 406 nm and a weak peak at 485 nm, suggesting their potential applications in light and electron emission devices.

Journal Article↗
PubMed2006

Generation and analysis of expressed sequence tags from NaCl-treated Glycine soja.

BACKGROUND: Salinization causes negative effects on plant productivity and poses an increasingly serious threat to the sustainability of agriculture. Wild soybean (Glycine soja) can survive in highly saline conditions, therefore provides an ideal candidate plant system for salt tolerance gene mining. RESULTS: As a first step towards the characterization of genes that contribute to combating salinity stress, we constructed a full-length cDNA library of Glycine soja (50109) leaf treated with 150 mM NaCl, using the SMART technology. Random expressed sequence tag (EST) sequencing of 2,219 clones produced 2,003 cleaned ESTs for gene expression analysis. The average read length of cleaned ESTs was 454 bp, with an average GC content of 40%. These ESTs were assembled using the PHRAP program to generate 375 contigs and 696 singlets. The resulting unigenes were categorized according to the Gene Ontology (GO) hierarchy. The potential roles of gene products associated with stress related ESTs were discussed. We compared the EST sequences of Glycine soja to that of Glycine max by using the blastn algorithm. Most expressed sequences from wild soybean exhibited similarity with soybean. All our EST data are available on the Internet (GenBank_Accn: DT082443-DT084445). CONCLUSION: The Glycine soja ESTs will be used to mine salt tolerance gene, whose full-length cDNAs will be obtained easily from the full-length cDNA library. Comparison of Glycine soja ESTs with those of Glycine max revealed the potential to investigate the wild soybean's expression profile using the soybean's gene chip. This will provide opportunities to understand the genetic mechanisms underlying stress response of plants.

Arabidopsis↗
PubMed2006

Tissue-cell- and species-specific expression of gonadotropin-regulated long chain acyl-CoA synthetase (GR-LACS) in gonads, adrenal and brain. Identification of novel forms in the brain.

Gonadotropin-regulated long chain acyl-CoA synthetase (GR-LACS) is a novel hormonally regulated fatty acyl-CoA synthetase (FACS) with activity for long-chain fatty acids. The presence of this enzyme in the Leydig cells of the mature rat testis and its mode of regulation suggest that it participates in testicular steroidogenesis. This study demonstrates that GR-LACS expression is tissue, cell and species-specific. The 79 kDa GR-LACS protein is expressed in rodent gonads and brain, and only in the mouse in the adrenal cortex. In the ovary of both species it is associated with follicles undergoing atresia. It is present in the newborn and immature testis tubules and after puberty only in the Leydig cells. A distinct GR-LACS protein species of 64 kDa that was more abundant than the 79 kDa long form was found in the rat brain. Also, a minor 73 kDa form was observed in the rat brain and mouse ovary. Two novel species resulting from alternatively splicing of the GR-LACS gene were identified in a rat brain cDNA library: a short form 1 (S1) lacking exon 8 and short form 2 (S2) lacking exons 6-8. Expression studies revealed that the sizes of the S1/S2 proteins are comparable to those of the endogenous variant species. Neither S form contains FACSs activity, suggesting that exon 8 is essential for the enzymatic function. GR-LACS variants exhibit small but significant dominant negative effects on the FACS activity of the long form. GR-LACS variants may regulate the long form's activity in the brain.

Adrenal Glands↗
PubMed2006

Identification of tumor precursor cells in the brains of primates with radiation-induced de novo glioblastoma multiforme.

The pathogenesis of de novo glioblastoma multiforme (GBM) is poorly understood and precursor cells are not known. To gain insight into the pathogenesis of GBM we analyzed brains from primates that developed de novo tumors ten years after whole brain radiation. Four animals had clinical and radiological evidence of GBM, and two animals had no evidence of GBM at the time of euthanization. Tumor precursor cells were identified diffusely scattered in the grossly normal white matter of all animals including two monkeys without evidence of GBM by MR-imaging or on autopsy examination. Tumor precursors demonstrated cellular atypia and mitoses, and were negative for tumor-associated markers GFAP, EGFR and p53. The cells were positive for Ki67 and N-CoR, the nuclear corepressor of astroglial differentiation. These results suggest that radiation-induced nuclear damage to neural stem cells or early astrocytic precursor cells can prevent normal differentiation and lead to tumor development. The findings provide insight into the tumorigenesis of de novo GBMs and suggest a new strategy for treatment of these lethal tumors by targeting both inactivation of N-CoR and inhibition of EGFR.

Animals↗
PubMed2006

[Arthroscopic treatment of the giant cell tumor of tendon sheath in knee joint].

OBJECTIVE: To explore the technique of diagnosis and treatment of intra-articular giant cell tumor of tendon sheath (GCTTS) in knee joint, and to evaluate its clinical results. METHODS: Twelve patients with GCTTS treated during 15 years were reviewed. Nine cases were misdiagnosed with meniscus injury (6 cases) and chronic synovitis (3 cases) before operation, only 3 cases were confirmed the diagnosis of GCTTS by MRI. Complete tumorectomy under arthroscope was performed on all 12 cases. RESULTS: The results of clinical and radiographic followed-up of 9 patients for 1 to 10 years after operation was satisfactory. Clinical symptoms disappeared, range of motion and X-ray findings were normal. There was no recurrent case found. CONCLUSIONS: Arthroscopic removal of GCTTS is an effective treatment. Tumor wide resection and debriding the channel which tumor passed through are the key point to prevent the recurrence after operation.

Adult↗
PubMed2006

Three homeotropically aligned nematic liquid crystals: comparison of ultrafast to slow time-scale dynamics.

The dynamics of two nematic liquid crystals, 4-(trans-4(')-n-octylcyclohexyl)isothiocyanatobenzene and 4-(4-pentyl-cyclohexyl)-benzonitrile, are investigated as a function of temperature both in the homeotropically aligned nematic phase and in the isotropic phase using optical heterodyne-detected optical Kerr effect experiments, which measures the time derivative of the polarizability-polarizability-correlation function (orientational relaxation). Data are presented over a time range of 500 fs-70 micros for the nematic phase and 500 fs to a few hundred nanoseconds for the isotropic phase. The nematic dynamics are compared with a previously studied liquid crystal in the nematic phase. All three liquid crystals have very similar dynamics in the nematic phase that are very different from the isotropic phase. On the slowest time scale (20 ns-70 micros), a temperature-independent power law, the final power law, t(-f) with f approximately 0.5, is observed. On short time scales (approximately 3 ps to approximately 1 ns), a temperature-dependent intermediate power law is observed with an exponent that displays a linear dependence on the nematic order parameter. Between the intermediate power law and the final power law, there is a crossover region that has an inflection point. For times that are short compared to the intermediate power law (approximately <2 ps), the data decay much faster, and can be described as a third power law, although this functional form is not definitive. The isotopic phase data have the same features as found in previous studies of nematogens in the isotropic phase, i.e., the temperature-independent intermediate power law and von Schweidler power law at short to intermediate times, and a highly temperature-dependent long time exponential decay that is well described by the Landau-de Gennes theory. The results show that liquid-crystal dynamics in the nematic phase exhibit universal behavior.

Journal Article↗
PubMed2006

Delta-subunit confers novel biophysical features to alpha beta gamma-human epithelial sodium channel (ENaC) via a physical interaction.

Native amiloride-sensitive Na+ channels exhibit a variety of biophysical properties, including variable sensitivities to amiloride, different ion selectivities, and diverse unitary conductances. The molecular basis of these differences has not been elucidated. We tested the hypothesis that co-expression of delta-epithelial sodium channel (ENaC) underlies, at least in part, the multiplicity of amiloride-sensitive Na+ conductances in epithelial cells. For example, the delta-subunit may form multimeric channels with alpha beta gamma-ENaC. Reverse transcription-PCR revealed that delta-ENaC is co-expressed with alpha beta gamma-subunits in cultured human lung (H441 and A549), pancreatic (CFPAC), and colonic epithelial cells (Caco-2). Indirect immunofluorescence microscopy revealed that delta-ENaC is co-expressed with alpha-, beta-, and gamma-ENaC in H441 cells at the protein level. Measurement of current-voltage that cation selectivity ratios for the revealed relationships Na+/Li+/K+/Cs+/Ca2+/Mg2+, the apparent dissociation constant (Ki) for amiloride, and unitary conductances for delta alpha beta gamma-ENaC differed from those of both alpha beta gamma- and delta beta gamma-ENaC (n = 6). The contribution of the delta subunit to P(Li)/P(Na) ratio and unitary Na+ conductance under bi-ionic conditions depended on the injected cRNA concentration. In addition, the EC50 for proton activation, mean open and closed times, and the self-inhibition time of delta alpha beta gamma-ENaC differed from those of alpha beta gamma- and delta beta gamma-ENaC. Co-immunoprecipitation of delta-ENaC with alpha- and gamma-subunits in H441 and transfected COS-7 cells suggests an interaction among these proteins. We, therefore, concluded that the interactions of delta-ENaC with other subunits could account for heterogeneity of native epithelial channels.

Amiloride↗