Biomedical subjects

Zhihong Yang

Publications and source records attributed to Zhihong Yang.

At least 19 recordsLinked to original sources

PubMed2025

Silencing FAF2 mitigates alcohol-induced hepatic steatosis by modulating lipolysis and PCSK9 pathway.

BACKGROUND: Chronic alcohol consumption leads to lipid accumulation, oxidative stress, cellular damage, and inflammation in the liver, collectively referred to as alcohol-associated liver disease (ALD). FAF2/UBXD8/ETEA (Fas-associated factor 2) is a ubiquitin ligase adaptor protein that plays a crucial role in the ubiquitin-mediated degradation of misfolded proteins in the endoplasmic reticulum. A recent genome-wide association study indicated an association between FAF2 and ALD; however, the exact contribution of FAF2 to ALD pathogenesis remains unclear. METHODS: FAF2 was knocked down using AAV-delivered shRNA in C57/BL6 mice. Mice were subjected to a chronic-plus-single binge ethanol feeding (NIAAA) model. Nine hours after gavage, liver, blood, and other organs of interest were collected for gene expression and biochemical analyses. RESULTS: We first observed a significant elevation in hepatic FAF2 protein expression in individuals with ALD and in mice subjected to an ethanol-binge model. Interestingly, knocking down FAF2 in the liver using adeno-associated virus serotype 8-delivered short hairpin RNA conferred a protective effect against alcohol-induced liver steatosis in ethanol-binged mice. Transcriptomic analysis revealed that differentially expressed genes were enriched in multiple lipid metabolism regulation pathways. Further analysis of transcription factors regulating these differentially expressed genes suggested potential regulation by SREBP1. Several SREBP1 target genes, including Fasn, Scd1, Lpin1, and Pcsk9 (proprotein convertase subtilisin/kexin type 9), were dysregulated in the livers of ethanol-fed FAF2 knockdown mice. Additionally, Pcsk9 could be regulated through the FOXO3-SIRT6 pathway in the livers of ethanol-fed FAF2 knockdown mice, leading to increased liver low-density lipoprotein receptor expression and reduced plasma LDL cholesterol levels. Furthermore, FAF2 knockdown in mouse liver enhanced adipose triglyceride lipase lipolytic activity by upregulating the adipose triglyceride lipase activator, comparative gene identification-58, and downregulating the adipose triglyceridelipase transport inhibitor, Elmod2, contributing to the alleviation of liver steatosis. CONCLUSIONS: Our study uncovers a novel mechanism involving FAF2 in the pathogenesis of ALD.

Animals↗

PubMed2006

Tissue type-specific modulation of ER transcriptional activity by NFAT3.

NFAT3 belongs to the NFAT family of transcription factors playing important roles in the development of several organ systems and was found to act as a transcriptional coactivator of estrogen receptors (ERalpha and ERbeta) in breast cancer cells. Since some cofactors of transcription factors show cell or tissue type-specific effects on transcriptional regulation, we investigated the effect of NFAT3 on the transcriptional activity of ERs in different cell lines originated from kidney. Surprisingly, overexpression of NFAT3 in these cell types decreased dose-dependently both ERalpha and ERbeta transcriptional activities in a ligand-independent manner. Knockdown of endogenous NFAT3 using NFAT3 small interfering RNA (siRNA) increased ER transcriptional activities. NFAT3 deletion mutants lacking the ER-binding sites completely abolished the NFAT3 repression of ERalpha and ERbeta transcriptional activities. Replacement of Ser168 and Ser170, the amino acid residues on which NFAT3 can be phosphorylated, with Ala did not change the ability of NFAT3 to inhibit the transcriptional activity of ERalpha and ERbeta. Taken together, these results demonstrate that NFAT3 is a new kind of cofactor that displays dual transcription modulation mode dependent on tissue types.

Amino Acid Sequence↗

PubMed2006

Impaired function and expression of P-glycoprotein in blood-brain barrier of streptozotocin-induced diabetic rats.

The aim was to investigate the effect of diabetes mellitus (DM) on P-glycoprotein (P-GP) function and expression in rat blood-brain barrier (BBB). P-GP function in BBB was assessed by measuring the brain-to-plasma concentration ratios (Kp values) of rhodamine 123 (Rho123) and vincristine (VCR), two well-known P-GP substrates, in control rats and 5-week streptozotocin (STZ)-induced diabetic rats. Evans blue (EB) dye was used as a BBB integrity indicator for examining the extravasation from the blood into the brain. P-GP expression in the brain cortex was evaluated with Western blot. The uptakes of Rho123 and VCR by cultured rat brain microvessel endothelial cells (rBMECs) incubated in diabetic and control rat serum for 72 h were also used to examine P-GP function, respectively. It was found that the Kp value of Rho123 (0.022+/-0.005 vs. 0.016+/-0.002 ml/g brain, p=0.033) and VCR (0.072+/-0.028 vs. 0.023+/-0.006 ml/g brain, p=0.006) in diabetic rats was significantly higher than that in control rats. The uptakes of Rho123 and VCR by cultured rBMECs incubated in the diabetic rat serum were higher than that in the control rat serum, respectively. No significant difference of the EB concentration in the brain cortex was found between the diabetic rats and control rats. Electron microscope examination of the brain cortex did not show a clear damage to the endothelial cells of microvessel in diabetic rats. In addition, the protein level of P-GP in the brains of the diabetic rats examined was significantly lower than that of control rats. These results suggested that the function and expression of P-GP might be impaired in the BBB of STZ-induced diabetic rats.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2006

Dimethyl sulfoxide inhibits tissue factor expression, thrombus formation, and vascular smooth muscle cell activation: a potential treatment strategy for drug-eluting stents.

BACKGROUND: Subacute stent thrombosis is a major clinical concern, and the search for new molecules to cover stents remains important. Dimethyl sulfoxide (DMSO) is used for preservation of hematopoietic progenitor cells and is infused into patients undergoing bone marrow transplantation. Despite its intravenous application, the impact of DMSO on vascular cells has not been assessed. METHODS AND RESULTS: In human endothelial cells, monocytes, and vascular smooth muscle cells (VSMC), DMSO inhibited tissue factor (TF) expression and activity in response to tumor necrosis factor-alpha or thrombin in a concentration-dependent manner. DMSO did not exert any toxic effects as assessed by phase-contrast microscopy, trypan blue exclusion, and lactate dehydrogenase release. Real-time polymerase chain reaction revealed that inhibition of TF expression occurred at the mRNA level. This effect was mediated by reduced activation of the mitogen-activated protein kinases c-Jun terminal NH2 kinase (51+/-6%; P=0.0005) and p38 (50+/-3%; P<0.0001) but not p44/42 (P=NS). In contrast to TF, DMSO did not affect expression of TF pathway inhibitor or plasminogen activator inhibitor-1. In vivo, DMSO treatment suppressed TF activity (41%; P<0.002) and prevented thrombotic occlusion in a mouse carotid artery photochemical injury model. DMSO also inhibited VSMC proliferation (70%; P=0.005) and migration (77%; P=0.0001) in a concentration-dependent manner; moreover, it prevented rapamycin and paclitaxel-induced upregulation of TF expression. CONCLUSIONS: DMSO suppresses TF expression and activity, as well as thrombus formation; in addition, it inhibits VSMC proliferation and migration. Given its routine use in modern clinical practice, we propose DMSO as a novel strategy for coating drug-eluting stents and treating acute coronary syndromes.

Animals↗

PubMed2006

Comparison of dye degradation efficiency using ZnO powders with various size scales.

ZnO powders with various size scales (mean diameter size: 10, 50, 200 and 1000nm) have been prepared by two different preparation methods, thermal evaporation method and chemical deposition method, and examined as photocatalysts for the UV-induced degradation of methyl orange in water solution. ZnO nanoparticle with diameter size 50nm prepared by thermal evaporation method showed the highest photocatalytic activity. In addition, the tetrapod ZnO nanopowders had the higher efficiency than irregular ZnO particles. However, the smallest 10nm ZnO nanoparticle prepared by chemical deposition method indicated the lower efficiency contrast to 200nm ZnO powders prepared by thermal evaporation method. The results indicated preparation method was the decisive factor rather than size and morphology. Moreover, the effect of catalyst loading, pH value and the initial dye concentration on the final degradation efficiency were discussed through the photocatalytic experiments using 50nm ZnO nanoparticle as photocatalyst.

Azo Compounds↗

PubMed2006

Different vascular smooth muscle cell apoptosis in the human internal mammary artery and the saphenous vein. Implications for bypass graft disease.

BACKGROUND: The remarkable patency of internal mammary artery (MA) grafts compared to saphenous vein (SV) grafts has been related to different biological properties of the two blood vessels. We examined whether proliferation and apoptosis of vascular smooth muscle cells (VSMC) from human coronary artery bypass vessels differ according to patency rates. METHODS AND RESULTS: Proliferation rates to serum or platelet-derived growth factor (PDGF)-BB were lower in VSMC from MA than SV. Surface expression of PDGF beta-receptor was slightly lower, while that of alpha-receptor was slightly higher in MA than SV. Cell cycle distribution, expression of cyclin E, cdk2, p21, p27, p57, and cdk2 kinase activity were identical in PDGF-BB-stimulated cells from MA and SV. However, apoptosis rates were higher in MA than SV determined by lactate dehydrogenase release, DNA fragmentation, and Hoechst 33258 staining. Moreover, caspase inhibitors (Z-VAD-fmk, Boc-D-fmk) abrogated the different proliferation rates of VSMC from MA versus SV. Western blotting and GSK3-beta kinase assay revealed lower Akt activity in VSMC from MA versus SV, while total Akt expression was identical. Adenoviral transduction of a constitutively active Akt mutant abrogated the different proliferation rates of VSMC from MA versus SV. CONCLUSIONS: Higher apoptosis rates due to lower Akt activity rather than different cell cycle regulation account for the lower proliferation of VSMC from MA as compared to SV. VSMC apoptosis may protect MA from bypass graft disease.

Apoptosis↗

PubMed2006

Hyaluronic acid and its derivative as a multi-functional gene expression enhancer: protection from non-specific interactions, adhesion to targeted cells, and transcriptional activation.

Hyaluronic acid (HA), a natural anionic mucopolysaccharide, can be deposited onto the cationic surface of DNA/polyethyleneimine (PEI) complexes to recharge the surface potential and reduce nonspecific interactions with proteins. HA can also be used as a ligand to target specific cell receptors. Furthermore, HA-coating enhanced the transcriptional activity of the plasmid/PEI complexes, probably by loosening the tight binding between DNA and PEI, which facilitated the approach of transcription factors. Amphoteric HA derivative having spermine side chains (Spn-HA) with a structure similar to HMG protein showed higher transcription-enhancing activity than HA. Plasmid/PEI/Spn-HA ternary complex exhibited 29-fold higher transgene expression efficiency than naked plasmid/PEI complexes in CHO cells.

Animals↗

PubMed2006

Zn2+ release from zinc and zinc oxide particles in simulated uterine solution.

Zn(2+) release from Zn and ZnO particles with different sizes in simulated uterine solution were investigated by absorbance measurements. The effects of pH and human serum albumin (HSA) on Zn(2+) release were also studied. The morphology of Zn and ZnO particles was observed by scanning electron microscopy, and the corrosion products of zinc nanoparticles were analyzed by XRD. The results indicate that the maximum release ratios of Zn(2+) from Zn and ZnO nanoparticles are higher than those from Zn and ZnO microparticles. Zn(2+) release ratio depends not only on the pH of the simulated uterine solution but also the presence of human serum albumin. It decreases as the pH of the uterine solution increases. The trends of Zn(2+) release ratios are almost the opposite for solutions with and without HSA. XRD analysis results indicate that zinc oxide is the main corrosion product of zinc particles.

Absorption↗

PubMed2006

Endothelial arginase: a new target in atherosclerosis.

Decreased endothelial nitric oxide (NO) bioavailability as it relates to endothelial dysfunction plays an important role in various cardiovascular disorders, including athero-sclerosis. Recent research has provided evidence that endothelial dysfunction in atherosclerosis is not primarily caused by decreased endothelial NO synthase (eNOS) gene expression, but rather deregulation of eNOS enzymatic activity, which contributes to the increased oxidative stress in atherosclerosis. Among other mechanisms, the substrate L-arginine is an important limiting factor for NO production. Emerging evidence demonstrates that L-arginine is not only converted to NO via eNOS, but also metabolized to urea and l-ornithine via arginase in endothelial cells. Hence, arginase competes with eNOS for the substrate L-arginine, resulting in deceased NO production. There are an increasing number of studies showing that enhanced arginase gene expression and/or activity contribute to endothelial dysfunction in various cardiovascular disorders, including atherosclerosis. Thus, endothelial arginase may represent a new therapeutic target in atherosclerosis.

Animals↗

PubMed2006

Recent advances in understanding endothelial dysfunction in atherosclerosis.

Over the last two decades, it has become evident that decreased bioavailability of endothelial nitric oxide (NO) produced from endothelial NO synthase (eNOS), referred to as endothelial dysfunction, plays a crucial role in the development and progression of atherosclerosis. Much progress has been made in understanding the mechanisms of decreased endothelial NO bioavailability at the levels of regulation of eNOS gene expression, eNOS enzymatic activity and NO inactivation. Initial studies suggest that increasing eNOS gene expression would improve endothelial NO release in the hope of inhibiting the progression of atherosclerosis. Recent experimental studies, however, do not always support this therapeutic concept and show some evidence that overexpression of eNOS in atherosclerosis may be even harmful for the disease progression.Thus, recent research to improve endothelial function in atherosclerosis has focused on regulation of eNOS enzymatic activity and prevention of NO inactivation by oxidative stress. Since the role of oxidative stress in endothelial NO bioavailability has been reviewed in a large number of comprehensive articles, this article focuses on the relevant regulatory mechanisms of eNOS enzymatic activity that are emerging to play a role in endothelial dysfunction in atherosclerosis.

Animals↗

PubMed2005

Controlled organization of ZnO building blocks into complex nanostructures.

ZnO complex nanostructure with special mushroom-like morphology was prepared by hydrolysis of zinc acetate dehydrate (Zn(CH3COO)2 2H2O) in water-methanol mixed solvent at 60 degrees C. The formation mechanism was studied using XRD investigation and FE-SEM observation, which showed that the mushroom-like particles were transformed from cauliflower-like layered basic zinc acetate (LBZA), Zn5(OH)8(CH3COO)22H2O, and composed of ZnO subunits with average size less than 10 nm. The introduction of hexamethylenetetramine (HMTA, C6H12N4) to the solution before deposition led to drastic changes in the morphologies of both aggregation particles and ZnO subunits. The novel ZnO microspheres, which were made of regular hexagonal plate-like ZnO with dimensional size 35 x 10 nm, were formed. These hexagonal plate-like ZnO subunits stacked very compactly and aligned regularly. Kinetic study of this unique complex nanostructure using TEM and FE-SEM observation showed the presence of HMTA played an important role on the formation of hexagonal ZnO subunits through different mechanisms related to the different parts of microspheres.

Journal Article↗

PubMed2005

Stabilization of PML nuclear localization by conjugation and oligomerization of SUMO-3.

The PML gene of acute promyelocytic leukemia (APL) encodes a cell-growth and tumor suppressor. PML localizes to discrete nuclear bodies (NBs) that are disrupted in APL cells, resulting from a reciprocal chromosome translocation t (15;17). Here we show that the nuclear localization of PML is also regulated by SUMO-3, one of the three recently identified SUMO isoforms in human cells. SUMO-3 bears similar subcellular distribution to those of SUMO-1 and -2 in the interphase nuclear body, which is colocalized with PML protein. However, both SUMO-2 and -3 are also localized to nucleoli, a region lacking SUMO-1. Immunoprecipitated PML protein bears SUMO-3 moiety in a covalently modified form, supporting the notion that PML is conjugated by SUMO-3. To determine the functional relevance of SUMO-3 conjugation on PML molecular dynamics, we suppressed SUMO-3 protein expression using a siRNA-mediated approach. Depletion of SUMO-3 markedly reduced the number of PML-containing NBa and their integrity, which is rescued by exogenous expression of SUMO-3 but not SUMO-1 or SUMO-2. The specific requirement of SUMO-3 for PML nuclear localization is validated by expression of SUMO-3 conjugation defective mutant. Moreover, we demonstrate that oligomerization of SUMO-3 is required for PML retention in the nucleus. Taken together, our studies provide first line of evidence showing that SUMO-3 is essential for PML localization and offer novel insight into the pathobiochemistry of APL.

Blotting, Western↗

PubMed2005

Statins prevent pulsatile stretch-induced proliferation of human saphenous vein smooth muscle cells via inhibition of Rho/Rho-kinase pathway.

OBJECTIVE: Pulsatile forces regulate vascular remodeling and trigger vascular diseases such as saphenous vein graft disease. The saphenous vein is exposed to high pressure and pulsatility only after implantation. Statins have been proved to reduce the incidence of vein graft failure. Thus, we investigated the molecular mechanisms of pulsatile stretch-induced saphenous vein smooth muscle cell (SMC) proliferation and potential beneficial effects of statins. METHODS AND RESULTS: Human saphenous vein SMCs were subjected to cyclic stretch (60 cycles/min) in Flex I plates. Cerivastatin and simvastatin significantly prevented stretch-induced increase in SMC proliferation. Stretch induced the membrane accumulation of Rho A and Rho kinase inhibitors (Y-27632 and hydroxyfasudil) and dominant negative Rho A mutant significantly prevented stretch-induced SMC proliferation. In addition, stretch increased the levels of both p44/42 mitogen-activated protein (MAP) kinase and Akt phosphorylation. MAP kinase kinase (MEK)1/2 inhibitor U0126, phosphatidylinositol (PI) 3-kinase inhibitors (wortmannin and LY294002), and dominant negative Akt mutant significantly prevented stretch-induced SMC proliferation. Cerivastatin significantly prevented stretch-induced membrane accumulation of Rho A. On the other hand, stretch-induced phosphorylation of p44/42 MAP kinase and Akt was not prevented by cerivastatin. Mevalonate restored the preventive effect of cerivasatain on stretch-induced Rho A membrane accumulation. Stretch induced hyperphosphorylation of retinoblastoma protein (pRb), which was prevented by cerivastatin and the Rho kinase inhibitors. CONCLUSION: Statins prevent stretch-induced saphenous vein SMC proliferation via inhibition of the Rho/Rho-kinase pathway. This may explain the beneficial effects of this class of drug, especially for patients after coronary artery bypass grafting.

Blotting, Western↗

PubMed2005

Mature adipocytes and perivascular adipose tissue stimulate vascular smooth muscle cell proliferation: effects of aging and obesity.

Adipocytes and perivascular adipose tissue are emerging as regulators of vascular function. The effects of adipocytes and perivascular adipose tissue on human smooth muscle cell (SMC) proliferation were investigated. Conditioned medium was prepared from cultured premature and differentiated 3T3-L1 adipocytes and from periaortic adipose tissue from young (3 mo) and old (24 mo) Wistar-Kyoto (WKY) rats, lean and obese Zucker rats (3 mo), and WKY rats fed normal chow or a high-fat diet for 3 mo. Conditioned medium from differentiated (but not premature) adipocytes stimulated SMC proliferation, which was abolished by charcoal and proteinase K treatment but was resistant to heat, trypsin, or phospholipase B (to hydrolyze lysophosphatidic acid). Further experiments demonstrated that the growth factor(s) are hydrosoluble and present in the fraction of molecular mass >100 kDa. Moreover, conditioned medium from periaortic adipose tissue stimulated SMC proliferation, which was significantly enhanced in aged rats and in rats fed a high-fat diet but not in obese Zucker rats deficient in functional leptin receptors. In conclusion, mature adipocytes release hydrosoluble protein growth factor(s) with a molecular mass >100 kDa for SMCs. Perivascular adipose tissue stimulates SMC proliferation, which is enhanced in aged WKY and in high-fat, diet-induced obesity but not in leptin receptor-deficient obese Zucker rats. These adipocyte-derived growth factor(s) and the effect of perivascular adipose tissue may be involved in vascular disease associated with aging and obesity.

Adipocytes↗

PubMed2005

Sirolimus increases tissue factor expression but not activity in cultured human vascular smooth muscle cells.

BACKGROUND: Sirolimus-eluting stents (CYPHER stents) demonstrated remarkable efficacy in reducing restenosis rates in patients with coronary artery disease. There is a concern of sub-acute and late stent thrombosis. Tissue factor (TF) is critical in thrombosis. This study investigated the effect of sirolimus on TF expression and activity in cultured human vascular smooth muscle cells (SMCs). METHODS: SMCs were cultured from human saphenous veins and aortas. Quiescent cells were stimulated with sirolimus (0.1 - 20 ng/ml) over 24 hours. Cellular TF expression and activity released into culture medium were measured. The effect of sirolimus on activation of mammalian target of rapamycin (mTOR) was measured by phosphorylation of the substrate p70s6k at T389, and activation of RhoA was measured by pull-down assay. RESULTS: Sirolimus increased TF protein level in cultured human SMCs in a concentration and time-dependent manner (about 2-fold, p < 0.01) reaching maximal effect at 5 ng/ml. The stimulation of TF expression by sirolimus was associated with inhibition of basal activity of mTOR. No effects of sirolimus on RhoA or p38mapk activation that are positive regulators of TF in vascular wall cells were observed. The stimulation of TF expression by sirolimus (20 ng/ml) was prevented by the HMG-CoA reductase inhibitor fluvastatin (1 micromol/L). However, no increase in TF activity released from SMC into culture medium was observed after sirolimus treatment. CONCLUSION: Although sirolimus stimulates TF protein expression in human SMC associated with inhibition of mTOR, it does not enhance TF activity released from the cells, suggesting a relatively safe profile of CYPHER stents. The inhibition of TF expression by fluvastatin favors clinical use of statins in patients undergoing coronary stenting.

Aorta↗

PubMed2004

Thrombin stimulates human endothelial arginase enzymatic activity via RhoA/ROCK pathway: implications for atherosclerotic endothelial dysfunction.

BACKGROUND: Arginase competes with endothelial nitric oxide synthase (eNOS) for the substrate l-arginine and decreases NO production. This study investigated regulatory mechanisms of arginase activity in endothelial cells and its role in atherosclerosis. METHODS AND RESULTS: In human endothelial cells isolated from umbilical veins, thrombin concentration- and time-dependently stimulated arginase enzymatic activity, reaching a 1.9-fold increase (P<0.001) at 1 U/mL for 24 hours. The effect of thrombin was prevented by C3 exoenzyme or the HMG-CoA reductase inhibitor fluvastatin, which inhibit RhoA, or by the ROCK inhibitors Y-27632 and HA-1077. Adenoviral expression of constitutively active RhoA or ROCK mutants enhanced arginase activity (approximately 3-fold, P<0.001), and the effect of active RhoA mutant was inhibited by the ROCK inhibitors. Neither thrombin nor the active RhoA/ROCK mutants affected arginase II protein level, the only isozyme detectable in the cells. Moreover, a significantly higher arginase II activity (1.5-fold, not the protein level) and RhoA protein level (4-fold) were observed in atherosclerotic aortas of apoE-/- compared with wild-type mice. Interestingly, l-arginine (1 mmol/L), despite a significantly higher eNOS expression in aortas of apoE-/- mice, evoked a more pronounced contraction, which was reverted to a greater vasodilation by the arginase inhibitor l-norvaline (20 mmol/L) compared with the wild-type animals (n=5, P<0.001). CONCLUSIONS: Thrombin enhances arginase activity via RhoA/ROCK in human endothelial cells. Higher arginase enzymatic activity is involved in atherosclerotic endothelial dysfunction in apoE-/- mice. Targeting vascular arginase may represent a novel therapeutic possibility for atherosclerosis.

Animals↗

PubMed2004

Endothelial nitric oxide synthase gene transfer restores endothelium-dependent relaxations and attenuates lesion formation in carotid arteries in apolipoprotein E-deficient mice.

Nitric oxide (NO) and monocyte chemoattractant protein-1 (MCP-1) exert partly opposing effects in vascular biology. NO plays pleiotropic vasoprotective roles including vasodilation and inhibition of platelet aggregation, smooth muscle cell proliferation, and endothelial monocyte adhesion, the last effect being mediated by MCP-1 downregulation. Early stages of arteriosclerosis are associated with reduced NO bioactivity and enhanced MCP-1 expression. We have evaluated adenovirus-mediated gene transfer of human endothelial NO synthase (eNOS) and of a N-terminal deletion (8ND) mutant of the MCP-1 gene that acts as a MCP-1 inhibitor in arteriosclerosis-prone, apolipoprotein E-deficient (ApoE(-/-)) mice. Endothelium-dependent relaxations were impaired in carotid arteries instilled with a noncoding adenoviral vector but were restored by eNOS gene transfer (p < 0.01). A perivascular collar was placed around the common carotid artery to accelerate lesion formation. eNOS gene transfer reduced lesion surface areas, intima/media ratios, and macrophage contents in the media at 5-week follow-up (p < 0.05). In contrast, 8ND-MCP-1 gene transfer did not prevent lesion formation. In conclusion, eNOS gene transfer restores endothelium-dependent vasodilation and inhibits lesion formation in ApoE(-/-) mouse carotids. Further studies are needed to assess whether vasoprotection is maintained at later disease stages and to evaluate the long-term efficacy of eNOS gene therapy for primary arteriosclerosis.

Adenoviridae↗

PubMed2004

Human Zwint-1 specifies localization of Zeste White 10 to kinetochores and is essential for mitotic checkpoint signaling.

Chromosome segregation in mitosis is orchestrated by dynamic interaction between spindle microtubules and the kinetochore, a multiprotein complex assembled onto centromeric DNA of the chromosome. Here we show that Zwint-1 is required and is sufficient for kinetochore localization of Zeste White 10 (ZW10) in HeLa cells. Zwint-1 specifies the kinetochore association of ZW10 by interacting with its N-terminal domain. Suppression of synthesis of Zwint-1 by small interfering RNA abolishes the localization of ZW10 to the kinetochore, demonstrating the requirement of Zwint-1 for ZW10 kinetochore localization. In addition, depletion of Zwint-1 affects no mitotic arrest but causes aberrant premature chromosome segregation. These Zwint-1-suppressed cells display chromosome bridge phenotype with sister chromatids inter-connected. Moreover, Zwint-1 is required for stable association of CENP-F and dynamitin but not BUB1 with the kinetochore. Finally, our studies show that Zwint-1 is a new component of the mitotic check-point, as cells lacking Zwint-1 fail to arrest in mitosis when exposed to microtubule inhibitors, yielding interphase cells with multinuclei. As ZW10 and Zwint-1 are absent from yeast, we reasoned that metazoans evolved an elaborate spindle checkpoint machinery to ensure faithful chromosome segregation in mitosis.

Animals↗