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Qiao RM, Ma JW, Guo YM, Duan YY, Zhou LH, Huang LS. Validation of a paternally imprinted QTL affecting pH24h distinct from PRKAG3 on SSC15. Anim Genet 2011; 42:316-20. [PMID: 21554348 DOI: 10.1111/j.1365-2052.2010.02133.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We previously performed a genome scan in a White Duroc × Erhualian F(2) population and identified a QTL on SSC15 with strong effect on pH24h in M. Longissimus dorsi and M. Semimembranous muscle tissue. At that time, the mode of inheritance of this QTL was not clarified, and it was also unclear whether the observed QTL effect was completely or partially caused by mutations in the PRKAG3 gene, which is the only major gene on SSC15 so far known to influence pH24h. In this study, effects of the PRKAG3 gene on meat quality traits were estimated by association analyses. Two substitutions in PRKAG3, p.Ile199Val (p.I199V) and p.Thr30Asn (p.T30N), were found to be segregating in the F(2) population and to significantly affect pH24h and total glycogen in meat, respectively. However, we excluded PRKAG3 as a causative gene for the detected QTL based on the following reasons: (i) the gene was located outside of the QTL confidence interval; (ii) when the PRKAG3 substitution was included as a fixed effect in the QTL model, the F-ratio for the QTL increased rather than decreased; (iii) favourable alleles for pH24h at the QTL and at the PRKAG3 p.I199V locus originated from Erhualian and White Duroc founders, respectively; (iv) more importantly, this QTL showed exclusive maternal expression, differing from the Mendelian expression of PRKAG3. In conclusion, this study is the first to report a maternally-expressed QTL for pH24h on SSC15, which is distinct from PRKAG3.
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Wei WH, Duan Y, Haley CS, Ren J, de Koning DJ, Huang LS. High throughput analyses of epistasis for swine body dimensions and organ weights. Anim Genet 2011; 42:15-21. [PMID: 20528845 DOI: 10.1111/j.1365-2052.2010.02082.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
High throughput analyses were performed to detect epistatic QTL in 17 body dimension and organ weight traits from a large F(2) pig population derived from a White Duroc and Erhualian intercross. The analyses used a nested test framework to handle multiple tests and a combined search algorithm to map epistatic QTL with empirical genome-wide thresholds derived via prior permutation. Alternative statistical models (e.g. including vs. excluding carcass weight as a covariate) were tested to develop an in-depth understanding of the role of epistasis in these kinds of traits. Epistasis signals were detected in only two or three traits under each statistical model studied. The interaction component of each pair of epistatic QTL explained a small proportion (0.7 to 2.1%) of the phenotypic variance in general. About half of the detected epistatic QTL pairs involved one of the two major QTL on porcine chromosomes 7 and 4. In those traits, the Erhualian allele consistently increased the phenotypes for the chromosome 7 QTL but decreased them for the chromosome 4 QTL. Models including carcass weight as covariate detected epistasis in body dimension traits whereas those excluding carcass weight found epistasis in organ weight traits. In addition, the epistasis results suggested that a QTL on chromosome 14 could be important for a number of organ weight traits. Using the high-throughput analysis tool to examine different statistical models was essential for the generation of a complete picture of epistasis in a whole category of traits.
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Huang LS, Chen JS, Hu JF, Ding YF. NiW/Ru underlayer for CoPt-SiO2 granular perpendicular recording media. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2011; 11:2636-2639. [PMID: 21449443 DOI: 10.1166/jnn.2011.2700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This paper presented the usage of the NiW/Ru underlayer to replace the single Ru underlayer for promoting CoPt hcp (0002) texture. Fcc (111) textured NiW film was used to induce the Ru hcp (0002) texture. It was found that the utilization of the (111) textured NiW alloying layer promoted the formation of Ru(0002) texture, enhanced the magnetic grain isolation and generated the uniform grains with gain size less than 10 nm in CoPt-SiO2 recording layer. The out-of-plane coercivity was also enhanced with the growth of 10 nm NiW underlayer below the Ru layer.
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Esteve A, Ojeda A, Huang LS, Folch JM, Pérez-Enciso M. Nucleotide variability of the porcine SERPINA6 gene and the origin of a putative causal mutation associated with meat quality. Anim Genet 2010; 42:235-41. [PMID: 21054451 DOI: 10.1111/j.1365-2052.2010.02138.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The serpin peptidase inhibitor, clade A, member 6 gene (SERPINA6), also known as corticosteroid-binding globulin or CBG, is involved in obesity and stress sensitivity. Previous studies have reported putative causal mutations within that gene in the porcine species. To characterize a hypothetical selective footprint, we have resequenced approximately 6 kb of coding and non-coding fragments in 20 pigs comprising domestic breeds and wild boars from Asia and Europe. Nucleotide variability was found to be far greater within Asian pig breeds than European breeds (π = 1% vs. 0.05%, respectively), which is consistent with pig evolutionary history. The putative causal amino acid substitution p.Gly307Arg (SNP c.919G>A) associated with meat quality (drip loss) was only detected in European domestic pig breeds, suggesting a very recent mutation that appeared after domestication in Europe. No support for positive selection was detected, as no reduction in levels of diversity surrounding the mutation was found in lean breeds with respect to wild boar.
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Jiao XT, Liu XQ, Huang LS, Zhang YJ, Han LS. [Role of caspase-3, -8, and -9 in apoptosis of copper induced primary cortical neurons]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2009; 11:917-922. [PMID: 20113661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE This study aimed to investigate the mechanism of primary cortical neuron injury induced by high concentrations of copper by observing the effect of aceticum culture medium on apoptosis of rat primary cortical neurons and expression of cleaved caspase 3, caspase 8 and caspase 9. METHODS Primary cortical neurons were cultured for 72 hrs and then exposed to different concentrations of aceticum culture medium (20, 40 and 80 microM). The viability of neurons was detected by the MTT method. Apoptosis was observed by Hoechst33258 and flow cytometry Annexin V/PI. Expression of caspase 3, caspase 8 and caspase 9 was measured by Western blot. RESULTS Following incubation with aceticum culture medium, apoptosis of neurons was induced. Theviability of neurons was remarkably reduced and the rate of apoptosis was tremendously increased in a concentration dependent manner. Caspase 8 and caspase 9 were activated in 20 microM of copper aceticum culture medium 4 hrs after incubation and peaked at 48 hrs in various concentrations of copper aceticum culture medium, presenting with a time and concentration dependent manner. The activated caspase 3 was observed in 20 microM of copper aceticum culture medium 24 hrs after incubation, which was later than the activated caspase 8 and caspase 9. Caspase 3 expression reached a peak 48 hrs in various concentrations of copper aceticum culture medium, presenting with a time and concentration dependent manner. CONCLUSIONS The apoptosis of primary cortical neurons can be induced by copper. Caspase 3, caspase 8 and caspase 9 cascade reaction may involve in the apoptosis of copper induced rat primary cortical neurons.
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Zhang ZY, Ren J, Ren DR, Ma JW, Guo YM, Huang LS. Mapping quantitative trait loci for feed consumption and feeding behaviors in a White Duroc x Chinese Erhualian resource population. J Anim Sci 2009; 87:3458-63. [PMID: 19684274 DOI: 10.2527/jas.2008-1694] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To identify QTL for feed consumption and feeding behavior traits in pigs, ADFI, feed conversion ratio (FCR), number of visits to the feeder per day (NVD), and average feeding rate (AFR) were recorded in 577 F(2) animals from a White Duroc x Chinese Erhualian resource population during the fattening period of 120 to 240 d. A whole genome scan was performed with 183 microsatellites covering the pig genome across the entire resource population. A total of 8 QTL were identified on 5 pig chromosomes, including 3 genome-wide significant QTL for FCR on SSC2, 7, and 9, 1 significant QTL for ADFI on SSC3, and 1 for NVD on SSC7. These QTL were identified for the first time, except for the QTL for FCR on SSC2. Four of the 5 significant QTL were adjacent to the known QTL for growth, carcass, and fat deposition traits, supporting the existence of gene(s) with pleiotropic effects on these traits. White Duroc alleles were generally associated with greater phenotypic values, except for those on SSC7 and 9. Comparison of QTL for feed consumption and feeding behaviors indicated that distinct chromosomes had effects on the 2 types of traits. Characterization of causative gene(s) underlying the identified QTL would shed new light on the genetic basis of feed consumption and feeding behaviors in pigs.
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Ramírez O, Ojeda A, Tomàs A, Gallardo D, Huang LS, Folch JM, Clop A, Sánchez A, Badaoui B, Hanotte O, Galman-Omitogun O, Makuza SM, Soto H, Cadillo J, Kelly L, Cho IC, Yeghoyan S, Pérez-Enciso M, Amills M. Integrating Y-chromosome, mitochondrial, and autosomal data to analyze the origin of pig breeds. Mol Biol Evol 2009; 26:2061-72. [PMID: 19535739 DOI: 10.1093/molbev/msp118] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We have investigated the origin of swine breeds through the joint analysis of mitochondrial, microsatellite, and Y-chromosome polymorphisms in a sample of pigs and wild boars with a worldwide distribution. Genetic differentiation between pigs and wild boars was remarkably weak, likely as a consequence of a sustained gene flow between both populations. The analysis of nuclear markers evidenced the existence of a close genetic relationship between Near Eastern and European wild boars making it difficult to infer their relative contributions to the gene pool of modern European breeds. Moreover, we have shown that European and Far Eastern pig populations have contributed maternal and paternal lineages to the foundation of African and South American breeds. Although West African pigs from Nigeria and Benin exclusively harbored European alleles, Far Eastern and European genetic signatures of similar intensity were detected in swine breeds from Eastern Africa. This region seems to have been a major point of entry of livestock species in the African continent as a result of the Indian Ocean trade. Finally, South American creole breeds had essentially a European ancestry although Asian Y-chromosome and mitochondrial haplotypes were found in a few Nicaraguan pigs. The existence of Spanish and Portuguese commercial routes linking Asia with America might have favored the introduction of Far Eastern breeds into this continent.
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Ding NS, Mao HR, Guo YM, Ren J, Xiao SJ, Wu GZ, Shen HQ, Wu LH, Ruan GF, Brenig B, Huang LS. A genome-wide scan reveals candidate susceptibility loci for pig hernias in an intercross between White Duroc and Erhualian. J Anim Sci 2009; 87:2469-74. [PMID: 19359506 DOI: 10.2527/jas.2008-1601] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pig scrotal/inguinal and umbilical hernias are the most prevalent congenital disorders in pigs and often cause animal welfare problems and economic loss. To identify susceptibility loci for these traits, a genome-wide scan with 194 microsatellite markers covering the pig genome was performed in a White Duroc x Erhualian resource population with 23 scrotal/inguinal F(2) animals, 50 umbilical F(2) animals, and their unaffected siblings. A sex-average linkage map with a total length of 2,350.3 cM and an average marker interval of 12.84 cM was constructed. Both nonparametric genome-wide linkage (NPL) analysis and transmission disequilibrium test (TDT) were implemented to detect closely linked markers. The NPL analysis revealed 11 chromosomal regions on SSC1, 2, 3, 6, 7, 8, 10, and 11 for umbilical hernia and 5 regions on SSC2, 4, 8, 13, and 16 for scrotal/inguinal hernia, whereas the TDT test identified susceptibility loci for umbilical hernia on SSC1, 2, 4, 7, 10, 13, 14, and 15 and for scrotal/inguinal hernias on SSC2, 8, 10, and 18. The most promising loci were SWR1928 on SSC7 and SW830 on SSC10 for umbilical hernia, and SW933 on SSC8 for scrotal hernia, which were consistently detected by both NPL and TDT. Several previously reported chromosomal regions for scrotal/inguinal hernia were confirmed, and new evidence for linkage with this pig defect was found. Moreover, susceptibility loci for pig umbilical hernia were detected for the first time.
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Cheung YF, Huang GY, Chen SB, Liu XQ, Xi L, Liang XC, Huang MR, Chen S, Huang LS, Liu XQ, Chan KW, Lau YL. Inflammatory gene polymorphisms and susceptibility to kawasaki disease and its arterial sequelae. Pediatrics 2008; 122:e608-14. [PMID: 18710885 DOI: 10.1542/peds.2008-0646] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE We tested the hypothesis that single-nucleotide polymorphisms of inflammatory genes C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-alpha) may exert influence on susceptibility to Kawasaki disease and its arterial sequelae. METHODS We analyzed the CRP +1444 C-->T and TNF-alpha -308 G-->A polymorphisms in 167 patients aged 8.9 +/- 4.1 years with a history of Kawasaki disease (73 with and 94 without coronary aneurysms) and 124 healthy control subjects. For patients with Kawasaki disease, we further determined whether these single-nucleotide polymorphisms were associated with coronary aneurysms, carotid arterial stiffening, and intima-media thickness. RESULTS Genotypic and allelic frequencies of CRP +1444 for T carrier and TNF-alpha -308 for A carrier were significantly higher in patients than in control subjects. The genotypic and allelic distributions did not differ between patients with and those without coronary aneurysms; however, patients with CRP +1444 CT/TT genotype compared with those with a CC genotype and patients with TNF-alpha -308 GA/AA genotype compared with those with a GG genotype had significantly greater carotid arterial stiffness and intima-media thickness. Carriers of both CRP +1444 T allele and TNF-alpha -308 A allele had the highest susceptibility to Kawasaki disease and a significant trend of increased arterial stiffness and intima-media thickness compared with those who carried either 1 or none of the rare alleles. Multiple linear regression analysis identified CRP +1444 allele carrier as a significant determinant of both carotid stiffness and carotid intima-media thickness and TNF-alpha -308 A allele carrier as a determinant of only intima-media thickness. CONCLUSIONS Our findings suggest that CRP +1444 C-->T and TNF-alpha -308 G-->A polymorphisms are associated with predisposition to Kawasaki disease and, in patients with Kawasaki disease, increased carotid arterial stiffness and intima-media thickness in the long-term.
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Xing YY, Huang LS, Brenig B, Knorr C. Radiation hybrid mapping of seven porcine calcium channel genes (CATSPER1-4 and CNGA1-3) associated with male fertility. Anim Genet 2008; 39:573-4. [PMID: 18644008 DOI: 10.1111/j.1365-2052.2008.01758.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Huang CJ, Gu XF, Zhang YJ, Ye J, Li D, Huang LS. [Effect of phenylalanine on the Nogo-66 receptor expression in the cortical neurons of rats]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2008; 10:211-215. [PMID: 18433550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
OBJECTIVE This study examined the effect of high concentration of phenylalanine (Phe) on Nogo-66 receptor (NgR) expression in the cortical neurons of rats in vitro in order to investigate whether NgR is involved in the etiology of Phe-induced brain damage. METHODS Neurons from the cerebral cortex of embryonic rats were cultured for 3 days and then were treated with 0.9 mM Phe. After 12, 24 and 48 hrs of Phe treatment, mRNA and protein expression of NgR was detected by real-time PCR and Western blot respectively. Growth cones and growth axons of neurons were detected by immunofluorescence and immunohistochemistry respectively after 12 and 24 hrs of Phe treatment. RESULTS The length of growth axons of neurons was significantly shorter after 12 and 24 hrs of Phe treatment compared with the control group without Phe treatment (P<0.05). Growth cones collapse occurred in 12.5+/-9.7% and 24.1+/-4.5% of neurons respectively after 12 and 24 hrs of Phe treatment but only in 3.5+/-1.5% in the control group (P<0.01). The protein level of NgR after 12, 24 and 48 hrs of Phe treatment was up-regulated, with 9.0, 9.4 and 12.6 times as the control. mRNA level of NgR in the Phe treatment group did not differ from control. CONCLUSIONS High concentration of Phe can induce an increased NgR protein expression in cortical neurons, and the increased NgR expression may contribute to the growth cones collapse and the inhibitory activities of axon regeneration after injury.
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Cui HS, Huang LS, Sok DE, Shin J, Kwon BM, Youn UJ, Bae K. Protective action of honokiol, administered orally, against oxidative stress in brain of mice challenged with NMDA. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2007; 14:696-700. [PMID: 17470388 DOI: 10.1016/j.phymed.2007.03.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Accepted: 07/11/2006] [Indexed: 05/15/2023]
Abstract
Neuroprotective effect of honokiol (HK), orally administered, on oxidative damage in the brain of mice challenged with N-methyl-d-aspartic acid (NMDA) was examined. HK (1-100 mg/kg) was administered to Institute of Cancer Research (ICR) male mice through a gavage for 3 days consecutively, and on the third day, NMDA (150 mg/kg) was intraperitoneally (i.p.) administered. Administration of NMDA, causing a lethality of approximately 60%, resulted in a significant decrease of total glutathione (GSH) level and increase of thiobarbituric acid-reactive substances (TBARS) value in brain tissue. Meanwhile, oral administration of HK (> or = 3 mg/kg) for 3 days reduced the lethality (60%) in NMDA-treated group to 10% level, and alleviated the behavioral signs of NMDA neurotoxicity. Moreover, HK pretreatment restored the levels of total GSH and TBARS in the brain tissue to control levels (p<0.01). Additionally, GSH peroxidase activity in cytosolic portion of brain homogenate was also restored significantly (p<0.01), whereas GSH reductase activity was not. Separately, compared to vehicle-treated control, no significant changes in body and brain weight were observed in mice administered with HK. Based on these results, oral intake of HK is suggested to prevent oxidative stress in the brain of mice.
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Knorr C, Beck J, Beuermann C, Chen K, Ding N, Gatphayak K, Huang LS, Laenoi W, Brenig B. Chromosomal assignment of porcine oncogenic and apoptopic genes CACNA2D2, TUSC4, ATP2A1, COL1A1, TAC1, BAK1 and CASP9. Anim Genet 2006; 37:523-5. [PMID: 16978189 DOI: 10.1111/j.1365-2052.2006.01507.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Chen KF, Beck J, Huang LS, Knorr C, Brenig B. Assignment of the phosphoglycerate kinase 1 (PGK1) gene to porcine chromosome Xq12-q13 by fluorescence in situ hybridization and hybrid panel analyses. Anim Genet 2004; 35:143-5. [PMID: 15025578 DOI: 10.1111/j.1365-2052.2004.01092.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chen KF, Beck J, Huang LS, Knorr C, Brenig B. Assignment of the phosphoglycerate kinase 2 (PGK2) gene to porcine chromosome 7q14-q15 by fluorescence in situ hybridization and by analysis of somatic cell and radiation hybrid panels. Anim Genet 2004; 35:71-2. [PMID: 14731237 DOI: 10.1046/j.1365-2052.2003.01066.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ren J, Knorr C, Habermann F, Fries R, Huang LS, Brenig B. Assignment of the porcine stearoyl-CoA desaturase (SCD) gene to SSC14q27 by fluorescence in situ hybridization and by hybrid panel mapping. Anim Genet 2004; 34:471-3. [PMID: 14687086 DOI: 10.1046/j.0268-9146.2003.01058.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Cobessi D, Huang LS, Ban M, Pon NG, Daldal F, Berry EA. The 2.6 A resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position'. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2002; 58:29-38. [PMID: 11752777 PMCID: PMC4615704 DOI: 10.1107/s0907444901017267] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2001] [Accepted: 10/15/2001] [Indexed: 11/10/2022]
Abstract
Bacterioferritin from Rhodobacter capsulatus was crystallized and its structure was solved at 2.6 A resolution. This first structure of a bacterioferritin from a photosynthetic organism is a spherical particle of 24 subunits displaying 432 point-group symmetry like ferritin and bacterioferritin from Escherichia coli. Crystallized in the I422 space group, its structural analysis reveals for the first time the non-symmetric heme molecule located on a twofold crystallographic symmetry axis. Other hemes of the protomer are situated on twofold noncrystallographic axes. Apparently, both types of sites bind heme in two orientations, leading to an average structure consisting of a symmetric 50:50 mixture, thus satisfying the crystallographic and noncrystallographic symmetry of the crystal. Five water molecules are situated close to the heme, which is bound in a hydrophobic pocket and axially coordinated by two crystallographic or noncrystallographically related methionine residues. Its ferroxidase center, in which Fe(II) is oxidized to Fe(III), is empty or fractionally occupied by a metal ion. Two positions are observed for the coordinating Glu18 side chain instead of one in the E. coli enzyme in which the site is occupied. This result suggests that the orientation of the Glu18 side chain could be constrained by this interaction.
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Siri P, Candela N, Zhang YL, Ko C, Eusufzai S, Ginsberg HN, Huang LS. Post-transcriptional stimulation of the assembly and secretion of triglyceride-rich apolipoprotein B lipoproteins in a mouse with selective deficiency of brown adipose tissue, obesity, and insulin resistance. J Biol Chem 2001; 276:46064-72. [PMID: 11598138 DOI: 10.1074/jbc.m108909200] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A mouse model of insulin resistance and its associated dyslipidemia was generated by crossing mice expressing human apolipoprotein B (apoB) with mice lacking only brown adipose tissue (BATless). On a high fat diet, male apoB/BATless mice became obese, hypercholesterolemic, hypertriglyceridemic, and hyperinsulinemic compared with control apoB mice. Fast performance liquid chromatography revealed increased triglyceride concentrations in intermediate density lipoprotein/low density lipoprotein (LDL) and reduced high density lipoprotein cholesterol concentrations. Inhibition of lipolysis by the drug, tetrahydrolipostatin, demonstrated that very low density lipoprotein-sized particles were initially secreted. Metabolic studies employing Triton WR-1339 and either [(3)H]glycerol or [(3)H]palmitate showed that the hypertriglyceridemia in apoB/BATless mice was due to the increased synthesis and secretion of triglyceride. Furthermore, lipoprotein lipase and hepatic lipase activities were not defective. ApoB was also secreted at increased rates in the apoB/BATless mice. Similar levels of apoB mRNA in apoB and apoB/BATless mice indicated that apoB secretion was regulated post-transcriptionally. LDL receptor mRNA was increased in the apoB/BATless mice, indicating that the observed increase in apoB-lipoprotein secretion was not due to their decreased reuptake. Finally, mRNA levels of the large subunit of microsomal triglyceride transfer protein, a required component for very low density protein assembly, were not different between apoB and apoB/BATless mice. This rodent model should prove useful in exploring mechanisms underlying the regulation of apoB secretion in the context of insulin resistance.
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Ko C, Lee TL, Lau PW, Li J, Davis BT, Voyiaziakis E, Allison DB, Chua SC, Huang LS. Two novel quantitative trait loci on mouse chromosomes 6 and 4 independently and synergistically regulate plasma apoB levels. J Lipid Res 2001; 42:844-55. [PMID: 11352992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
Abstract
An elevated plasma apolipoprotein B (apoB) level is a strong predictor of atherosclerosis and coronary heart disease. Epidemiologic and family linkage studies have suggested a genetic basis for the wide variations of plasma apoB levels in the general population. Using a human apoB transgenic (HuBTg) mouse model, we have previously shown that hepatic apoB-100 secretion is a major determinant of the high and low plasma human apoB levels in HuBTg mice of the C57BL/6 (B6) and 129/Sv (129) strains, respectively. In the present article, we present the identification of two novel quantitative trait loci (QTL) as major regulators of plasma human apoB levels in the F(2) and N(2) (backcrossed) offspring (n = 572) derived from crosses between the B6 and 129 mouse strains. These loci were designated ApoB regulator genes (Abrg), because the gene products are likely to be involved in the regulation of plasma apoB levels either directly or indirectly. The first locus, designated Abrg1, was mapped to chromosome 6 in 8-week-old male and female mice with a combined logarithm of odds ratio (LOD) score of 14 at the D6Mit55 marker ( approximately 45.9 cM). Abrg1 contributed approximately 35% of the genetic variance. The second locus, designated Abrg2, was mapped to chromosome 4 with an LOD score of 8.6 in 8-week-old male mice but an LOD score of only 2.0 in 8-week-old female mice at the D4Mit27 marker ( approximately 35 cM). Abrg2 contributed approximately 26% of the genetic variance. Epistasis between Abrg1 and Abrg2 was detected and accounted for approximately 12% of the genetic variance. The combination of these two QTL has major effects (>70%) on the regulation of plasma human apoB levels in the tested population. In summary, we have identified two novel loci that have a major role in the regulation of plasma apoB levels and are likely to regulate the secretory pathway of apoB. The human orthologs for the Abrg loci are strong candidates for human disorders characterized by altered plasma apoB levels, such as FCHL and familial hypobetalipoproteinemia.
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Chen KF, Huang LS, Li N, Zhang Q, Luo M, Wu CX. [The genetic effect of estrogen receptor(ESR) on litter size traits in pig]. YI CHUAN XUE BAO = ACTA GENETICA SINICA 2001; 27:853-7. [PMID: 11192427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Litter size is one of the most important economic traits in pig production, and the more piglet numbers per litter is capable to increase pork production and bring more economic profit for pig industry. ESR (estrogen receptor) gene has been determined to be one of the major genes affecting phenotype of litter size without any genetic negative correlation to growth and carcass traits. An optimized standard PCR-RFLP protocol is employed to type 262 sows from 5 different breeds in ESR loci, and then with the computation based on linear model ESR gene is confirmed to be a major locus significantly associated with litter size (P < 0.001). The genetic effect of ESR gene is quite large in these breeds, especially in these Chinese pig population. The sows of beneficial homozygote BB produce 1.40-3.37 total number born/litter and 0.63-3.58 number born alive/litter more than the sows of non-beneficial homozygote AA do. The information found in the present study is very important and could be utilized as DNA marker for improvement of reproduction trait in practice of pig breeding.
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Zhang Z, Berry EA, Huang LS, Kim SH. Mitochondrial cytochrome bc1 complex. Subcell Biochem 2001; 35:541-80. [PMID: 11192733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Abstract
The cytochrome bc complexes represent a phylogenetically diverse group of complexes of electron-transferring membrane proteins, most familiarly represented by the mitochondrial and bacterial bc1 complexes and the chloroplast and cyanobacterial b6f complex. All these complexes couple electron transfer to proton translocation across a closed lipid bilayer membrane, conserving the free energy released by the oxidation-reduction process in the form of an electrochemical proton gradient across the membrane. Recent exciting developments include the application of site-directed mutagenesis to define the role of conserved residues, and the emergence over the past five years of X-ray structures for several mitochondrial complexes, and for two important domains of the b6f complex.
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Ginsberg HN, Huang LS. The insulin resistance syndrome: impact on lipoprotein metabolism and atherothrombosis. JOURNAL OF CARDIOVASCULAR RISK 2000; 7:325-31. [PMID: 11143762 DOI: 10.1177/204748730000700505] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Insulin resistance is a common metabolic abnormality that is associated with an increased risk of both atherosclerosis and type 2 diabetes. The phenotype of insulin resistance includes a dyslipidemia characterized by an elevation of very low-density lipoprotein triglyceride, a reduction in high-density lipoprotein cholesterol, and the presence of small, triglyceride-enriched low-density lipoproteins. The underlying metabolic abnormality driving this dylipidemia is an increased assembly and secretion of very low-density lipoprotein particles, leading to an increased plasma level of triglyceride. Hypertriglyceridemia, in turn, results in a reduction in the high-density lipoprotein level and the generation of small, dense low-density lipoproteins; these events are mediated by cholesteryl ester transfer protein. In addition, hypertension, obesity, and a prothrombotic state are also integral components of the insulin resistance syndrome. In this review, we will provide a pathophysiologic basis, based on studies on humans and in tissue culture, for the dyslipidemia of insulin resistance. We will also review the effects of insulin resistance on the coagulation and fibrinolytic pathways. It is hoped that this review will allow health professionals better to evaluate and treat their patients with insulin resistance, thereby reducing the very much increased risk of atherosclerotic cardiovascular disease carried by these individuals.
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Chi YI, Huang LS, Zhang Z, Fernández-Velasco JG, Berry EA. X-ray structure of a truncated form of cytochrome f from chlamydomonas reinhardtii. Biochemistry 2000; 39:7689-701. [PMID: 10869174 DOI: 10.1021/bi000090k] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A truncated form of cytochrome f from Chlamydomonas reinhardtii (an important eukaryotic model organism for photosynthetic electron transfer studies) has been crystallized (space group P2(1)2(1)2(1); three molecules/asymmetric unit) and its structure determined to 2.0 A resolution by molecular replacement using the coordinates of a truncated turnip cytochrome f as a model. The structure displays the same folding and detailed features as turnip cytochrome f, including (a) an unusual heme Fe ligation by the alpha-amino group of tyrosine 1, (b) a cluster of lysine residues (proposed docking site of plastocyanin), and (c) the presence of a chain of seven water molecules bound to conserved residues and extending between the heme pocket and K58 and K66 at the lysine cluster. For this array of waters, we propose a structural role. Two cytochrome f molecules are related by a noncrystallographic symmetry operator which is a distorted proper 2-fold rotation. This may represent the dimeric relation of the monomers in situ; however, the heme orientation suggested by this model is not consistent with previous EPR measurements on oriented membranes.
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Kako Y, Huang LS, Yang J, Katopodis T, Ramakrishnan R, Goldberg IJ. Streptozotocin-induced diabetes in human apolipoprotein B transgenic mice. Effects on lipoproteins and atherosclerosis. J Lipid Res 1999; 40:2185-94. [PMID: 10588944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
The effects of diabetes and lipoprotein lipase (LpL) on plasma lipids were studied in mice expressing human apolipoprotein B (HuBTg). Our overall objective was to produce a diabetic mouse model in which the sole effects of blood glucose elevation on atherosclerosis could be assessed. Mice were made diabetic by intraperitoneal injection of streptozotocin, which led to a 2- to 2. 5-fold increase in plasma glucose. Lipids were assessed in mice on chow and on an atherogenic Western type diet (WTD), consisting of 21% (wt/wt) fat and 0.15% (wt/wt) cholesterol. Plasma triglyceride and cholesterol were the same in diabetic and non-diabetic mice on the chow diet. On the WTD, male diabetic HuBTg mice had a >50% increase in plasma cholesterol and more very low density lipoprotein (VLDL) cholesterol and triglyceride as assessed by FPLC analysis. A Triton study showed no increase in triglyceride or apolipoprotein B production, suggesting that the accumulation of VLDL was due to a decrease in lipoprotein clearance. Surprisingly, the VLDL increase in these mice was not due to a decrease in LpL activity in postheparin plasma. To test whether LpL overexpression would alter these diabetes-induced lipoprotein changes, HuBTg mice were crossed with mice expressing human LpL in muscle. LpL overexpression reduced plasma triglyceride, but not cholesterol, in male mice on WTD. Aortic root atherosclerosis assessed in 32-week-old mice on the WTD was not greater in diabetic mice. In summary, diabetes primarily increased plasma VLDL in HuBTg mice. LpL activity was not decreased in these animals. However, additional LpL expression eliminated the diabetic lipoprotein changes. These mice did not have more atherosclerosis with diabetes.
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