Paternal gene pool of Malays in Southeast Asia and its applications for the early expansion of Austronesians.

OBJECTIVES: The origin and differentiation of Austronesian populations and their languages have long fascinated linguists, archeologists, and geneticists. However, the founding process of Austronesians and when they separated from their close relatives, such as the Daic and Austro-Asiatic populations in the mainland of Asia, remain unclear. In this study, we explored the paternal origin of Malays in Southeast Asia and the early differentiation of Austronesians. MATERIALS AND METHODS: We generated whole Y-chromosome sequences of 50 Malays and co-analyzed 200 sequences from other Austronesians and related populations. We generated a revised phylogenetic tree with time estimation. RESULTS: We identified six founding paternal lineages among the studied Malays samples. These founding lineages showed a surprisingly coincident expansion age at 5000 to 6000 years ago. We also found numerous mostly close related samples of the founding lineages of Malays among populations from Mainland of Asia. CONCLUSION: Our analyses provided a refined phylogenetic resolution for the dominant paternal lineages of Austronesians found by previous studies. We suggested that the co-expansion of numerous founding paternal lineages corresponds to the initial differentiation of the most recent common ancestor of modern Austronesians. The splitting time and divergence pattern in perspective of paternal Y-chromosome evidence are highly consistent with the previous theories of ethnologists, linguists, and archeologists.

Whole sequence analysis indicates a recent southern origin of Mongolian Y-chromosome C2c1a1a1-M407.

The Y-chromosome haplogroup C2c1a1a1-M407 is a predominant paternal lineage in Mongolic-speaking populations, especially in Buryats and Kalmyks. However, the origin and internal phylogeny of C2c1a1a1-M407 have not been investigated in detail. In this study, we analyzed twenty-three Y-chromosome sequences of haplogroup C2c1a1a1-M407 and its most closely related clades. We generated a high-resolution phylogenetic tree of haplogroup C2c1a1a1-M407 and its upstream clade C2c1a1-CTS2657, including 32 subclades and 144 non-private Y-chromosome polymorphisms. We discover that all available C2c1a1a1-M407 samples from Mongolic-speaking populations belong to its newly defined downstream clade C2c1a1a1b-F8465, whereas all samples of C2c1a1-CTS2657(xF8465) come from northern Han Chinese, Korean, and Japanese. Furthermore, we observe that C2c1a1a1b-F8465 and its subclade C2c1a1a1b1-F8536 expanded at approximately 0.86 and 0.44 thousand years ago, respectively. Therefore, we conclude that C2c1a1a1-M407 in Mongolic-speaking populations has originated from northeastern Asia. C2c1a1a1b1-F8536, the newly defined subclade of C2c1a1a1-M407, probably represents the genetic relationships between ancient Oyrats, modern Kalmyks, Mongolians, and Buryats.

Reconstruction of Y-chromosome phylogeny reveals two neolithic expansions of Tibeto-Burman populations.

Diffusion of Tibeto-Burman populations across the Tibetan Plateau led to the largest human community in a high-altitude environment and has long been a focus of research on high-altitude adaptation, archeology, genetics, and linguistics. However, much uncertainty remains regarding the origin, diversification, and expansion of Tibeto-Burman populations. In this study, we analyzed a 7.0M bp region of 285 Y-chromosome sequences, including 81 newly reported ones, from male samples from Tibeto-Burman populations and other related Eastern Asian populations. We identified several paternal lineages specific to Tibeto-Burman populations, and most of these lineages emerged between 6000 and 2500 years ago. A phylogenetic tree and lineage dating both support the hypothesis that the establishment of Tibeto-Burman ancestral groups was triggered by Neolithic expansions from the middle Yellow River Basin and admixtures with local populations on the Tibetan Plateau who survived the Paleolithic Age. Furthermore, according to the geographical distributions of the haplogroups, we propose that there are two Neolithic expansion origins for all modern Tibeto-Burman populations. Our research provides a clear scenario about the sources, admixture process and later diffusion process of the ancestor population of all Tibeto-Burman populations.

A comparative analysis of genetic diversity of candidate genes associated with type 2 diabetes in worldwide populations.

Over the last decade, a larger number of type 2 diabetes mellitus (T2DM) susceptible candidate genes have been reported by numerous genome-wide association studies (GWAS). Understanding the genetic diversity of these candidate genes among worldwide populations not only facilitates to elucidating the genetic mechanism of T2DM, but also provides guidance to further studies of pathogenesis of T2DM in any certain population. In this study, we identified 170 genes or genomic regions associated with T2DM by searching the GWAS databases and related literatures. We next analyzed the genetic diversity of these genes (or genomic regions) among present-day human populations by curetting the 1000 Genomes Projects phase1 dataset covering 14 worldwide populations. We further compared the characteristics of T2DM genes in different populations. No significant differences of genetic diversity were observed among the 14 worldwide populations between the T2DM candidate genes and the non-T2DM genes in terms of overall pattern. However, we observed some genes, such as IL20RA, RNMTL1-NXN, NOTCH2, ADRA2A-BTBD7P2, TBC1D4, RBM38-HMGB1P1, UBE2E2, and PPARD, show considerable differentiation between populations. In particular, IL20RA (FST=0.1521) displays the greatest population difference which is mainly contributed by that between Africans and non-Africans. Moreover, we revealed genetic differences between East Asians and Europeans on some candidate genes such as DGKB-AGMO (FST=0.173) and JAZF1 (FST=0.182). Our results indicate that some T2DM susceptible candidate genes harbor highly-differentiated variants between populations. These analyses, despite preliminary, should advance our understanding of the population difference of susceptibility to T2DM and provide insightful reference that future studies can relay on.

Effects of cyclooxygenase inhibition on cardiovascular function in a hypercholesterolemic swine model of chronic ischemia.

The cardiovascular effects of cyclooxygenase (COX) inhibition remain controversial, especially in the setting of cardiovascular comorbidities. We examined the effects of nonselective and selective COX inhibition on cardiovascular function in a hypercholesterolemic swine model of chronic ischemia. Twenty-four intact male Yorkshire swine underwent left circumflex ameroid constrictor placement and were subsequently given either no drug (HCC; n = 8), a nonselective COX inhibitor (440 mg/day naproxen; HCNS; n = 8), or a selective COX-2 inhibitor (200 mg/day celecoxib; HCCX; n = 8). After 7 wk, myocardial functional was measured and myocardium from the nonischemic ventricle and ischemic area-at-risk (AAR) were analyzed. Regional function as measured by segmental shortening was improved in the AAR of HCCX compared with HCC. There was no significant difference in perfusion to the nonischemic ventricle between groups, but myocardial perfusion in the AAR was significantly improved in the HCCX group compared with controls at rest and during pacing. Endothelium-dependent microvessel relaxation was diminished by ischemia in HCC animals, but both naproxen and celecoxib improved vessel relaxation in the AAR compared with controls, and also decreased the vasoconstrictive response to serotonin. Thromboxane levels in the AAR were decreased in both HCNS and HCCX compared with HCC, whereas prostacyclin levels were decreased only in HCNS, corresponding to a decrease in prostacyclin synthase expression. Chronic ischemia increased apoptosis in Troponin T negative cells and intramyocardial fibrosis, both of which were reduced by celecoxib administration in the AAR. Capillary density was decreased in both the HCNS and HCCX groups. Protein oxidative stress was decreased in both HCNS and HCCX, whereas lipid oxidative stress was decreased only in the HCCX group. Thus nonselective and especially selective COX inhibition may have beneficial myocardial effects in the setting of hypercholesterolemia and chronic ischemia. Whether these effects modulate cardiovascular risk in patients taking these drugs remains to be seen, but evidence to date suggests that they do not.

Effects of neuropeptide Y on collateral development in a swine model of chronic myocardial ischemia.

We investigated the role of neuropeptide Y (NPY), abundant in the myocardial sympathetic nervous system and endothelial cells, in angiogenesis during chronic myocardial ischemia. Adult male Yorkshire swine underwent ameroid constrictor placement on the proximal left circumflex coronary artery. After 3 weeks, an osmotic pump was placed to deliver either placebo (control, n=8) or NPY(3-36) (NPY, n=8) to the collateral dependent region. Five weeks after pump placement, after cardiac catheterization and hemodynamic assessment, the heart was harvested for analysis. NPY treated animals demonstrated increased mean arterial pressures and improved left ventricular function (+dP/dt). Cardiac catheterization demonstrated a significant increase in the blush score in the NPY group (p<0.001). Blood flow to the ischemic myocardium was not different between groups at rest or during ventricular pacing. Immunohistochemical double staining for CD-31 and smooth muscle actin demonstrated an increase in capillary and arteriole formation in NPY treated animals (p=0.02 and p<0.001). Immunoblotting showed a significant upregulation of DPPIV (p=0.009) and NPY receptors 1 (p=0.008), 2 (p=0.02) and 5 (p=0.03) in the NPY treated group. Additionally, there was significant upregulation of VEGF (p=0.04), eNOS (p=0.014), phospho-eNOS (ser1177) (p=0.02), and PDGF (p<0.001) in NPY treated group. The anti-angiogenic factors endostatin and angiostatin were significantly decreased in NPY treated animals (endostatin, p=0.03; angiostatin, p=0.04). Exogenous NPY(3-36) resulted in improved myocardial function and increased angiogenesis and arteriogenesis by stimulating growth factor, pro-angiogenic receptor upregulation, and decreasing anti-angiogenic expression, but did not increase blood flow to the ischemic myocardium. NPY may act as a good adjunct to primary agents of therapeutic angiogenesis.

[Three-dimensional model analysis of obstructive sleep apnea hyponea syndrome patients with long-term treatment of oral appliances].

PURPOSE: The aim of the study was to investigate the dental changes of patients with obstructive sleep apnea hypopnea syndrome (OSAHS) with long-term treatment of oral appliances, via the method of three-dimensional model analysis. METHODS: Using Geomagic Studio 2014 software, we transferred the dental models, which were from 18 OSAHS patients before and after treatment of oral appliances, into three-dimensional models for digital analysis. Datasets obtained from pre- and after treatment were compared for accuracy via paired t test using SPSS 22.0 software package. RESULTS: Eighteen patients using oral appliances for 6.57±1.98 years, showed significant differences in some dentition values between pre-treatment and after-treatment. The total dentition changes indicated intrusion of upper premolars, buccalization of upper posterior teeth and mesialization of lower posterior teeth. Statistical analysis demonstrated decrease in upper dental arch length, increase in upper posterior arch width and decrease in upper arch depth and dramatic reduction of overjet in anterior teeth. In the same time, other values evaluated showed no significant change before and after treatment of oral appliances. CONCLUSIONS: Long-term wearing oral appliances results in changes in several variables of dental occlusion, which should not be ignored for dentists conducting this treatment plan. However, the side effect of dental occlusion changes is little on a whole, leading to high security in this aspect.

Novel genetic loci affecting facial shape variation in humans.

The human face represents a combined set of highly heritable phenotypes, but knowledge on its genetic architecture remains limited, despite the relevance for various fields. A series of genome-wide association studies on 78 facial shape phenotypes quantified from 3-dimensional facial images of 10,115 Europeans identified 24 genetic loci reaching study-wide suggestive association (p < 5 × 10-8), among which 17 were previously unreported. A follow-up multi-ethnic study in additional 7917 individuals confirmed 10 loci including six unreported ones (padjusted < 2.1 × 10-3). A global map of derived polygenic face scores assembled facial features in major continental groups consistent with anthropological knowledge. Analyses of epigenomic datasets from cranial neural crest cells revealed abundant cis-regulatory activities at the face-associated genetic loci. Luciferase reporter assays in neural crest progenitor cells highlighted enhancer activities of several face-associated DNA variants. These results substantially advance our understanding of the genetic basis underlying human facial variation and provide candidates for future in-vivo functional studies.

Functional, cellular, and molecular characterization of the angiogenic response to chronic myocardial ischemia in diabetes.

BACKGROUND: Ischemic heart disease is the most common cause of mortality in diabetic patients. Although therapeutic angiogenesis is an attractive option for these patients, they appear to have reduced collateral formation in response to myocardial ischemia. The aims of this study were to establish a large animal model of diabetes and chronic myocardial ischemia, evaluate the effects of diabetes on the angiogenic response, and elucidate the molecular pathways involved. METHODS AND RESULTS: Diabetes was induced in male Yucatan miniswine using a pancreatic beta-cell specific toxin, alloxan (150 mg/kg; n=8). Age-matched swine served as controls (n=8). Eight weeks after induction, chronic ischemia was induced by ameroid constrictor placement around the circumflex coronary artery. Myocardial perfusion and function were assessed at 3 and 7 weeks after ameroid placement using isotope-labeled microspheres. Endothelial cell density and myocardial expression of angiogenic mediators was evaluated. Diabetic animals exhibited significant endothelial dysfunction. Collateral dependent perfusion and LV function were significantly impaired in diabetic animals. Diabetic animals also demonstrated reduced endothelial cell density (173+/-14 versus 234+/-23 cells/hpf, P=0.03). Expression of VEGF, Ang-1, and Tie-2 was reduced, whereas antiangiogenic proteins, angiostatin (4.4+/-0.9-fold increase, P<0.001), and endostatin (2.9+/-0.4-fold increase, P=0.03) were significantly elevated in the diabetic myocardium. CONCLUSIONS: Diabetes results in a profound impairment in the myocardial angiogenic response to chronic ischemia. Pro- and antiangiogenic mediators identified in this study offer novel targets for the modulation of the angiogenic response in diabetes.

Comparison of vascular endothelial growth factor and fibroblast growth factor-2 in a swine model of endothelial dysfunction.

OBJECTIVE: Growth factor based angiogenesis, with or without cell therapy, is a promising therapeutic modality for patients with coronary artery disease. We compared the relative efficacies of surgically delivered vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) in a swine model of hypercholesterolemia-induced endothelial dysfunction which captures many of the pathophysiologic abnormalities of human coronary disease. METHODS: Yucatan mini-swine (20-30 kg), fed a high cholesterol diet (total 20 weeks), underwent circumflex ameroid placement to create chronic myocardial ischemia, followed three weeks later by perivascular administration of VEGF (2 microg; n=6), FGF-2 (100 microg; n=6), or placebo (n=7) in the ischemic territory. Normocholesterolemic animals (n=7) served as controls. Four weeks later, endothelial function, collateral-dependent perfusion, as well as myocardial protein and mRNA levels of angiogenic mediators were assessed. RESULTS: Endothelial dysfunction was observed in all hypercholesterolemic animals as impaired microvessel relaxation in response to adenosine diphosphate and VEGF. VEGF administration improved baseline-adjusted collateral-dependent perfusion at rest (-0.03+/-0.05 vs -0.12+/-0.04, VEGF vs placebo, p=0.09), but FGF-2 delivery caused a significantly greater improvement in perfusion compared to either group (+0.15+/-0.03, p<0.05 vs HC-placebo and HC-VEGF) at rest. Molecular analysis revealed increased eNOS expression (135%+/-8%, p=0.03 vs placebo) in all growth factor treated animals and increased expression of FGF-2 receptor, FGFR1 (65+/-26%, p=0.04 vs placebo), in FGF-2 treated animals. No significant changes were demonstrated in other angiogenic mediators including Akt, Syndecan-4. CONCLUSIONS: In the setting of hypercholesterolemic endothelial dysfunction, FGF-2 is more effective than VEGF at enhancing collateral-dependent perfusion and thus, may be a better candidate than VEGF for angiogenic therapy in patients with end-stage CAD.

Whole-sequence analysis indicates that the Y chromosome C2*-Star Cluster traces back to ordinary Mongols, rather than Genghis Khan.

The Y-chromosome haplogroup C3*-Star Cluster (revised to C2*-ST in this study) was proposed to be the Y-profile of Genghis Khan. Here, we re-examined the origin of C2*-ST and its associations with Genghis Khan and Mongol populations. We analyzed 34 Y-chromosome sequences of haplogroup C2*-ST and its most closely related lineage. We redefined this paternal lineage as C2b1a3a1-F3796 and generated a highly revised phylogenetic tree of the haplogroup, including 36 sub-lineages and 265 non-private Y-chromosome variants. We performed a comprehensive analysis and age estimation of this lineage in eastern Eurasia, including 18,210 individuals from 292 populations. We discovered that the origin of populations with high frequencies of C2*-ST can be traced to either an ancient Niru'un Mongol clan or ordinary Mongol tribes. Importantly, the age of the most recent common ancestor of C2*-ST (2576 years, 95% CI = 1975-3178) and its sub-lineages, and their expansion patterns, are consistent with the diffusion of all Mongolic-speaking populations, rather than Genghis Khan himself or his close male relatives. We concluded that haplogroup C2*-ST is one of the founder paternal lineages of all Mongolic-speaking populations, and direct evidence of an association between C2*-ST and Genghis Khan has yet to be discovered.

Role of stromal-derived factor-1alpha in the induction of circulating CD34+CXCR4+ progenitor cells after cardiac surgery.

BACKGROUND: Cardioplegia and cardiopulmonary bypass (CP/CPB) leads to an increase in circulating progenitor cells. The role of stromal-derived factor-1alpha (SDF-1alpha), a key regulator of progenitor cell mobilization, and other cytokines in this process is not clear. METHODS AND RESULTS: Peripheral blood (n=24), atrial and skeletal tissue (n=6) samples were taken from patients undergoing CP/CPB before (pre-CP/CPB), 4 hours (post-CP/CPB), and 4 days (POD4) after CP/CPB. The number of circulating CD34+CXCR4+ cells increased post-CP/CPB (442+/-53 versus 286+/-27; P=0.04 versus pre-CP/CPB), but not at POD4 (382+/-50; P=0.28 versus pre-CP/CPB). Plasma levels of SDF-1alpha increased post-CP/CPB as compared with pre-CP/CPB (3325+/-325 versus 2911+/-165 pg/mL; P=0.046) but returned to baseline at POD4 (2838+/-224 pg/mL; P=0.90). Plasma levels of vascular endothelial growth factor were similar post-CP/CPB (P=0.90 versus pre-CP/CPB) but increased at POD4 (220+/-40 pg/mL versus 134+/-26 pg/mL; P=0.04 versus pre-CP/CPB). Serum levels of granulocyte-colony stimulating factor (G-CSF) increased early after CP/CPB as compared with pre-CP/CPB (265.0+/-41.7 versus 11.1+/-1.1 pg/mL; P<0.001) and returned to baseline at POD4 (P=0.84 versus pre-CP/CPB). The circulating CD34+CXCR4+ cells were positively correlated with plasma levels of SDF-1alpha early after CP/CPB (r=0.56, P<0.01), but not at other times. Protein expression of SDF-1alpha was elevated in the atrial myocardium after CP/CPB (9.4-fold; P=0.03). CONCLUSIONS: Exposure to CP/CPB leads to an increase in circulating CD34+CXCR4+ progenitor cells, which is associated with increased myocardial SDF-1alpha expression. The numbers of CD34+CXCR4+ progenitor cells positively correlate with the plasma levels of SDF-1alpha post-CP/CPB, suggesting an important role of SDF-1alpha in progenitor cell mobilization.

Phylogeography of Y-chromosome haplogroup O3a2b2-N6 reveals patrilineal traces of Austronesian populations on the eastern coastal regions of Asia.

Austronesian diffusion is considered one of the greatest dispersals in human history; it led to the peopling of an extremely vast region, ranging from Madagascar in the Indian Ocean to Easter Island in Remote Oceania. The Y-chromosome haplogroup O3a2b*-P164(xM134), a predominant paternal lineage of Austronesian populations, is found at high frequencies in Polynesian populations. However, the internal phylogeny of this haplogroup remains poorly investigated. In this study, we analyzed -seventeen Y-chromosome sequences of haplogroup O3a2b*-P164(xM134) and generated a revised phylogenetic tree of this lineage based on 310 non-private Y-chromosome polymorphisms. We discovered that all available O3a2b*-P164(xM134) samples belong to the newly defined haplogroup O3a2b2-N6 and samples from Austronesian populations belong to the sublineage O3a2b2a2-F706. Additionally, we genotyped a series of Y-chromosome polymorphisms in a large collection of samples from China. We confirmed that the sublineage O3a2b2a2b-B451 is unique to Austronesian populations. We found that O3a2b2-N6 samples are widely distributed on the eastern coastal regions of Asia, from Korea to Vietnam. Furthermore, we propose- that the O3a2b2a2b-B451 lineage represents a genetic connection between ancestors of Austronesian populations and ancient populations in North China, where foxtail millet was domesticated about 11,000 years ago. The large number of newly defined Y-chromosome polymorphisms and the revised phylogenetic tree of O3a2b2-N6 will be helpful to explore the origin of proto-Austronesians and the early diffusion process of Austronesian populations.

GCH1 plays a role in the high-altitude adaptation of Tibetans.

Tibetans are well adapted to high-altitude hypoxia. Previous genome-wide scans have reported many candidate genes for this adaptation, but only a few have been studied. Here we report on a hypoxia gene ( GCH1, GTP-cyclohydrolase I), involved in maintaining nitric oxide synthetase (NOS) function and normal blood pressure, that harbors many potentially adaptive variants in Tibetans. We resequenced an 80.8 kb fragment covering the entire gene region of GCH1 in 50 unrelated Tibetans. Combined with previously published data, we demonstrated many GCH1 variants showing deep divergence between highlander Tibetans and lowlander Han Chinese. Neutrality tests confirmed a signal of positive Darwinian selection on GCH1 in Tibetans. Moreover, association analysis indicated that the Tibetan version of GCH1 was significantly associated with multiple physiological traits in Tibetans, including blood nitric oxide concentration, blood oxygen saturation, and hemoglobin concentration. Taken together, we propose that GCH1 plays a role in the genetic adaptation of Tibetans to high altitude hypoxia.

EP300 contributes to high-altitude adaptation in Tibetans by regulating nitric oxide production.

The genetic adaptation of Tibetans to high altitude hypoxia likely involves a group of genes in the hypoxic pathway, as suggested by earlier studies. To test the adaptive role of the previously reported candidate gene EP300 (histone acetyltransferase p300), we conducted resequencing of a 108.9 kb gene region of EP300 in 80 unrelated Tibetans. The allele-frequency and haplotype-based neutrality tests detected signals of positive Darwinian selection on EP300 in Tibetans, with a group of variants showing allelic divergence between Tibetans and lowland reference populations, including Han Chinese, Europeans, and Africans. Functional prediction suggested the involvement of multiple EP300 variants in gene expression regulation. More importantly, genetic association tests in 226 Tibetans indicated significant correlation of the adaptive EP300 variants with blood nitric oxide (NO) concentration. Collectively, we propose that EP300 harbors adaptive variants in Tibetans, which might contribute to high-altitude adaptation through regulating NO production.

Aprotinin preserves cellular junctions and reduces myocardial edema after regional ischemia and cardioplegic arrest.

BACKGROUND: Cardiac surgery with cardiopulmonary bypass (CPB) and cardioplegic arrest has been associated with myocardial edema attributable to vascular permeability, which is regulated in part by thrombin-induced alterations in cellular junctions. Aprotinin has been demonstrated to prevent activation of the thrombin protease-activated receptor, and we hypothesized that aprotinin preserves myocardial cellular junctions and prevents myocardial edema in a porcine model of regional ischemia and cardioplegic arrest. METHODS AND RESULTS: Fourteen pigs were subjected to 30 minutes of regional ischemia, followed by 60 minutes of CPB, with 45 minutes of crystalloid cardioplegia, then 90 minutes of post-CPB reperfusion. The treatment group (n=7) was administered aprotinin (40,000 kallikrein inhibitor units [KIU]/kg loading dose, 40,000 KIU/kg pump prime, and 10,000 KIU/kg per hour continuous infusion). Control animals (n=7) received normal saline. Myocardial vascular endothelial (VE)-cadherin, beta-catenin and gamma-catenin, and associated mitogen-activated protein kinase (MAPK) pathways were assessed by immunoblot and immunoprecipitation. Histologic analysis of the cellular junctions was done by immunofluorescence. Myocardial tissue water content was measured. VE-cadherin, beta-catenin, and gamma-catenin levels were significantly greater in the aprotinin group (all P<0.05). Immunfluorescence confirmed that aprotinin prevented loss of coronary endothelial adherens junction continuity. Aprotinin reduced tyrosine phosphorylation in myocardial tissue sections. Phospho-p38 activity was approximately 30% lower in the aprotinin group (P=0.007). The aprotinin group demonstrated decreased myocardial tissue water content (81.2+/-0.5% versus 83.5+/-0.3%; P=0.01) and reduced intravenous fluid requirements (2.9+/-0.2 L versus 4.0+/-0.4 L; P=0.03). CONCLUSIONS: Aprotinin preserves adherens junctions after regional ischemia and cardioplegic arrest through a mechanism potentially involving the p38 MAPK pathway, resulting in preservation of the VE barrier and reduced myocardial tissue edema.

Effects of L-arginine on fibroblast growth factor 2-induced angiogenesis in a model of endothelial dysfunction.

BACKGROUND: Nitric oxide availability, which is decreased in advanced coronary artery disease associated with endothelial dysfunction, is an important mediator of fibroblast growth factor-2 (FGF-2)-induced angiogenesis. This could explain the disappointing results of FGF-2 therapy in clinical trials despite promising preclinical studies. We examined the influence of L-arginine supplementation to FGF-2 therapy on myocardial microvascular reactivity and perfusion in a porcine model of endothelial dysfunction. METHODS AND RESULTS: Eighteen pigs were fed either a normal (NORM, n=6) or high cholesterol diet, with (HICHOL-ARG, n=6) or without (HICHOL, n=6) L-arginine. All pigs underwent ameroid placement on the circumflex artery and 3 weeks later received surgical FGF-2 treatment. Four weeks after treatment, endothelial-dependent coronary microvascular responses and lateral myocardial perfusion were assessed. Endothelial cell density was determined by immunohistochemistry. FGF-2, fibroblast growth receptor-1, endothelial-derived nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and syndecan-4 levels were determined by immunoblotting. Pigs from the HICHOL group showed endothelial dysfunction in the circumflex territory, which was normalized by L-arginine supplementation. FGF-2 treatment was ineffective in the HICHOL group (circumflex/left anterior descending blood flow ratios: 1.01 (rest) and 1.01 (pace), after and before treatment). Addition of L-arginine improved myocardial perfusion in response to FGF-2 at rest (ratio 1.13, P=0.02 versus HICHOL) but not during pacing (ratio 0.94, P=NS), and was associated with increased protein levels of iNOS and eNOS. CONCLUSIONS: L-arginine supplementation can partially restore the normal response to endothelium-dependent vasorelaxants and myocardial perfusion in response to FGF-2 treatment in a swine model of hypercholesterolemia-induced endothelial dysfunction. These findings suggest a role for L-arginine in combination with FGF-2 therapy for end-stage coronary artery disease.

Differences in gene expression profiles of diabetic and nondiabetic patients undergoing cardiopulmonary bypass and cardioplegic arrest.

BACKGROUND: Diabetes mellitus is an independent risk factor for early postoperative mortality and complications after coronary artery bypass grafting (CABG). We sought to compare the cardiac gene expression responses to cardiopulmonary bypass (CPB) and cardioplegic arrest (C) in patients with and without diabetes. METHODS AND RESULTS: Twenty atrial myocardium samples were harvested from 5 type II insulin-dependent diabetic and 5 matched nondiabetic patients undergoing CABG, before and after CPB/C. Oligonucleotide microarray analyses of 12625 genes were performed on the 10 sample pairs using matched pre-CPB tissues as controls. Array results were validated with Northern blotting and immunoblotting. Compared with pre-CPB/C, post-CPB/C myocardial tissues revealed 851 upregulated and 480 downregulated genes with a threshold P< or =0.025 (signal-to-noise ratio, 4.04) in the diabetic group, compared with 480 upregulated and 626 downregulated genes (signal-to-noise ratio, 3.04) in the nondiabetic group (P<0.001). There were 18 genes that were upregulated >4-fold in diabetic and nondiabetic patients (including inflammatory/transcription activators FOS, CYR 61, and IL-6, apoptotic gene NR4A1, stress gene DUSP1, and glucose-transporter gene SLC2A3). However, 28 genes showed such marked upregulation in the diabetic group exclusively (including inflammatory/transcription activators MYC, IL8, IL-1beta, growth factor vascular endothelial growth factor, amphiregulin, and glucose metabolism-involved gene insulin receptor substrate 1), and 27 genes in the nondiabetic group only, including glycogen-binding subunit PPP1R3C. CONCLUSIONS: Gene expression profile after CPB/C is quantitatively and qualitatively different in patients with diabetes. These results have important implications for the design of tailored myocardial protection and operative strategies for diabetic patients undergoing CPB/C.

Normalization of coronary microvascular reactivity and improvement in myocardial perfusion by surgical vascular endothelial growth factor therapy combined with oral supplementation of l-arginine in a porcine model of endothelial dysfunction.

OBJECTIVE: Vascular endothelial growth factor acts in part through nitric oxide release, the availability of which is decreased in endothelial dysfunction associated with advanced coronary artery disease. This could explain the relatively disappointing results of vascular endothelial growth factor therapy in clinical studies compared with animal studies. We examined the influence of L-arginine supplementation to vascular endothelial growth factor therapy on myocardial microvascular reactivity and perfusion in a porcine model of endothelial dysfunction. METHODS: Twenty-four pigs were fed either a normal (NORM, n = 8) or high-cholesterol diet with (CHOL-ARG, n = 8) or without (CHOL, n = 8) L-arginine. All pigs underwent ameroid placement on the circumflex artery and then 3 weeks later received surgical vascular endothelial growth factor treatment. Four weeks after treatment, endothelial-dependent coronary microvascular responses and lateral myocardial perfusion were assessed. Endothelial cell density was determined by means of immunohistochemistry. Vascular endothelial growth factor, endothelial nitric oxide synthase, and Akt levels were determined by means of immunoblotting. RESULTS: Pigs from the CHOL group showed endothelial dysfunction in the circumflex territory, which was normalized by L-arginine supplementation. Vascular endothelial growth factor treatment was ineffective in the CHOL group (circumflex/left anterior descending coronary artery blood flow ratios: 0.95 [rest] and 0.74 [pace] before-after treatment; P < .05 compared with the NORM group). Addition of L-arginine restored the angiogenic effect of vascular endothelial growth factor (ratios: 1.13 [rest] and 1.20 [pace]; P < .05) and was associated with increased endothelial cell density, as well as vascular endothelial growth factor, endothelial nitric oxide synthase, and Akt protein levels in the ischemic territory. CONCLUSIONS: L-Arginine supplementation can restore normal endothelium-dependent vasorelaxation and angiogenic response to vascular endothelial growth factor in a swine model of chronic myocardial ischemia with hypercholesterolemia-induced endothelial dysfunction. These findings suggest a putative role for L-arginine in combination with vascular endothelial growth factor therapy for end-stage coronary artery disease.

Effects of L-arginine on the endogenous angiogenic response in a model of hypercholesterolemia.

BACKGROUND: The angiogenic properties of vascular endothelial growth factor and fibroblast growth factor-2 are mediated in part through nitric oxide release, whose availability is decreased in endothelial dysfunction associated with advanced coronary artery disease. We examined the influence of L-arginine supplementation on the endogenous angiogenic response to ischemia in a porcine model of hypercholesterolemia. METHODS: Eighteen Yucatan pigs were fed either a normal (NORM, n=6) or a high-cholesterol diet, with (CHOL-ARG, n=6) or without (CHOL, n=6) L-arginine (100 mg/kg/day), throughout the experiment. All pigs underwent ameroid constrictor placement on the circumflex artery (LCx). Seven weeks later, endothelium-dependent coronary microvascular responses to fibroblast growth factor-2 and vascular endothelial growth factor were assessed by videomicroscopy. Perfusion was assessed with radioactive microspheres; angiogenesis was evaluated by platelet-endothelial cell adhesion molecule-1 (CD-31) staining. Regional myocardial function was assessed by sonomicrometry. Expression of endothelial nitric oxide synthase and inducible nitric oxide synthase was measured by Western blot analyses. RESULTS: Pigs from the CHOL group showed significant endothelial dysfunction in the LCx territory. The dysfunction was normalized partially by L-arginine supplementation, which restored the response in the LCx territory to the level of the nonischemic anterior wall. L-arginine supplementation resulted in increases of perfusion, density of capillary endothelial, and level of endothelial nitric oxide synthase in the ischemic region. Despite these findings, no improvement in myocardial regional function was found. CONCLUSIONS: L-arginine supplementation can partially restore endothelium-dependent vasorelaxation and improve myocardial perfusion in a swine model of chronic myocardial ischemia with hypercholesterolemia-induced endothelial dysfunction. These findings suggest a putative role for L-arginine in combination with growth factor therapy for end-stage coronary artery disease.