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Ross RJ, Zhou M, Shen D, Fariss RN, Ding X, Bojanowski CM, Tuo J, Chan CC. Immunological protein expression profile in Ccl2/Cx3cr1 deficient mice with lesions similar to age-related macular degeneration. Exp Eye Res 2008; 86:675-83. [PMID: 18308304 DOI: 10.1016/j.exer.2008.01.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Revised: 01/09/2008] [Accepted: 01/11/2008] [Indexed: 10/22/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in the United States. Ccl2 knock-out (KO) mice sporadically develop the cardinal features of AMD in their senescent stage. Humans bearing a loss of function variant or single nucleotide polymorphism (SNP) in CX3CR1 are at increased risk of developing AMD. We recently developed Ccl2(-/-)/Cx3cr1(-/-) mice, which consistently develop retinal degeneration with many AMD features. Since there is strong evidence for an immunological role in AMD pathogenesis, we examined ocular immune protein expression levels in Ccl2(-/-)/Cx3cr1(-/-), Ccl2(-/-), Cx3cr1(-/-), and age-matched wild-type (WT) mice. Immunohistochemistry revealed increased complement C3d in Bruch's membrane, retinal pigment epithelium (RPE), choroidal capillaries, and particularly drusen of the Ccl2(-/-)/Cx3cr1(-/-) mice relative to the WT controls. No change was detected in single KO mice. Real-time RT-PCR revealed a 2.5-fold increase in C3 expression in the Ccl2(-/-)/Cx3cr1(-/-). While the retinas of four month old WT and Ccl2(-/-) showed minimal immunoreactivity for markers of macrophages and microglia, infiltrates of these mononuclear phagocytic cells were detected in the Ccl2(-/-)/Cx3cr1(-/-)retinal lesions and a few foci in the Cx3cr1(-/-) retina. The Ccl2(-/-)/Cx3cr1(-/-) had reduced toll-like receptor 4 (TLR4) expression in the RPE. Following LPS injection, the Ccl2(-/-)/Cx3cr1(-/-) had significantly reduced endotoxin-induced uveitis scores and showed a diminished increase in Tlr4 mRNA expression. No changes in TLR4 expression were detected in either single KO. Autoantibodies against the retina and photoreceptors were also detected in the Ccl2(-/-)/Cx3cr1(-/-) serum. Real-time RT-PCR revealed significant increases in Ccl5 transcript in the Ccl2(-/-)/Cx3cr1(-/-) relative to the WT. These results suggest that innate immunity and possibly adaptive immunity play an important role in Ccl2(-/-)/Cx3cr1(-/-) retinal degeneration. Moreover, since human AMD patients show similar immunopathological profiles, these results support the Ccl2(-/-)/Cx3cr1(-/-) as a suitable model for human AMD.
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Tuo J, Bojanowski CM, Zhou M, Shen D, Ross RJ, Rosenberg KI, Cameron DJ, Yin C, Kowalak JA, Zhuang Z, Zhang K, Chan CC. Murine ccl2/cx3cr1 deficiency results in retinal lesions mimicking human age-related macular degeneration. Invest Ophthalmol Vis Sci 2007; 48:3827-36. [PMID: 17652758 PMCID: PMC2048751 DOI: 10.1167/iovs.07-0051] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Senescent Ccl2(-/-) mice are reported to develop cardinal features of human age-related macular degeneration (AMD). Loss-of-function single-nucleotide polymorphisms within CX3CR1 are also found to be associated with AMD. The authors generated Ccl2(-/-)/Cx3cr1(-/-) mice to establish a more characteristic and reproducible AMD model. METHODS Single Ccl2- and Cx3cr1-deficient mice were crossbred to obtain Ccl2(-/-)/Cx3cr1(-/-) mice. Funduscopy, histopathology, retinal A2E quantification, proteomics, RT-PCR gene expression assay, immunochemistry, and Western blotting were used to examine the retina and to evaluate gene expression within the retinal tissue. RESULTS By 6 weeks of age, all Ccl2(-/-)/Cx3cr1(-/-) mice developed AMD-like retinal lesions, including drusen, retinal pigment epithelium alteration, and photoreceptor degeneration. Furthermore, choroidal neovascularization occurred in 15% of the mice. These degenerative lesions progressed with age. A2E, a major lipofuscin fluorophore that accumulated during AMD progression, was significantly higher in the Ccl2(-/-)/Cx3cr1(-/-) retina than in the wild-type retina. Complement cofactor was higher in the Ccl2(-/-)/Cx3cr1(-/-) RPE. Proteomics data indicated that four proteins were differentially expressed in Ccl2(-/-)/Cx3cr1(-/-) retina compared with control. One of these proteins, ERp29, an endoplasmic reticulum protein, functions as an escort chaperone and in protein folding. CONCLUSIONS The authors concluded that Ccl2(-/-)/Cx3cr1(-/-) mice develop a broad spectrum of AMD abnormalities with early onset and high penetrance. These observations implicate certain chemokines and endoplasmic reticulum proteins in AMD pathogenesis. Similar to the mechanism of neurodegeneration caused by dysfunction of endoplasmic reticulum proteins, decreased chaperoning may cause misfolded protein accumulation, leading to drusen formation and retinal degeneration.
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Wang JJ, Ross RJ, Tuo J, Burlutsky G, Tan AG, Chan CC, Favaloro EJ, Williams A, Mitchell P. The LOC387715 polymorphism, inflammatory markers, smoking, and age-related macular degeneration. A population-based case-control study. Ophthalmology 2007; 115:693-9. [PMID: 17675241 PMCID: PMC2561271 DOI: 10.1016/j.ophtha.2007.05.038] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 05/23/2007] [Accepted: 05/23/2007] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE To assess combined effects on the risk of age-related macular degeneration (AMD) by the LOC387715 polymorphism, smoking, and inflammatory or hemostatic factors. DESIGN Population-based case-control study. PARTICIPANTS Two hundred seventy-eight AMD cases (224 early, 54 late) and 557 controls matched for age, gender, and smoking, drawn from the Blue Mountains Eye Study cohort. METHODS Subjects were genotyped for the LOC387715 Ala69Ser polymorphism (rs# 10490924). Smoking was self-reported. Serum high-sensitivity C-reactive protein (CRP), interleukin 6 (IL-6), soluble intercellular adhesion molecule 1 (sICAM-1), fibrinogen, homocysteine, plasminogen activator inhibitor 1 (PAI-1), von Willebrand factor, and white cell count (WCC) were measured. Combined effects of this genetic variant plus any of these study factors on AMD risk were assessed using logistic regression models, adjusted for age and smoking. We defined interaction if the influence of 2 factors departed from the multiplicative scale, confirmed by a statistically significant interaction term. Otherwise, the combined effect was used. MAIN OUTCOME MEASURES Age-related macular degeneration was graded using the Wisconsin grading system. RESULTS Combined effects on the likelihood of early or late AMD were demonstrated for the LOC387715 Ala69Ser G/T and T/T genotypes with the markers high-sensitivity CRP (odds ratios [ORs], 1.2 for the highest tertile alone, 1.6 for G/T and T/T genotypes alone, and 2.2 for both G/T and T/T genotypes plus the highest tertile, compared with the G/G genotype with the 2 lower tertiles), IL-6 (corresponding ORs, 1.1, 1.6, and 2.2), sICAM-1 (ORs, 1.0, 1.5, and 2.3, respectively), and PAI-1 (ORs, 1.3, 1.7, and 2.3, respectively), but not with WCC, fibrinogen, homocysteine, and von Willebrand factor. Findings were similar for early and late AMD separately. Current smokers with G/T and T/T genotypes had strong combined effects on late AMD risk compared with those who never smoked or past smokers with the G/G genotype (ORs, 1.2 for current smokers alone, 1.8 for G/T and T/T genotypes alone, and 6.1 for current smokers plus G/T and T/T genotypes). CONCLUSIONS We found no significant interaction but combined effects for the LOC387715 genotypes with 3 inflammatory markers and PAI-1 on the risk of early or late AMD, and with current smoking on the risk of late AMD.
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Ross RJ, Bojanowski CM, Wang JJ, Chew EY, Rochtchina E, Ferris FL, Mitchell P, Chan CC, Tuo J. The LOC387715 polymorphism and age-related macular degeneration: replication in three case-control samples. Invest Ophthalmol Vis Sci 2007; 48:1128-32. [PMID: 17325155 PMCID: PMC1885234 DOI: 10.1167/iovs.06-0999] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Age-related macular degeneration (AMD) is a multifactorial blinding disease in the elderly. LOC387715 harbors a single-nucleotide polymorphism that has an association with AMD. This study was conducted to confirm the association between LOC387715 and AMD and to refine estimates of the impact of this gene variation in using samples from three studies: an Australian population-based study and two U.S. clinic-based case-control studies. METHODS Cases and controls were collected from a National Eye Institute (NEI) clinical protocol (n = 240), the Age-Related Eye Disease Study (AREDS; n = 488), and the Blue Mountains Eye Study (BMES; n = 851). After DNA extraction, subjects were genotyped for the LOC387715 Ala69Ser polymorphism (rs10490924). RESULTS The combined NEI and AREDS samples yielded odds ratios (ORs) of 2.61 (95% CI 1.89-3.61, P = 1.42 x 10(-9)) and 8.59 (95% CI 4.49-16.5, P = 3.56 x 10(-13)) for the heterozygous and homozygous risk alleles, respectively. The corresponding odds ratios in the BMES sample were 1.69 (95% CI: 1.25-2.28, P = 0.0007) and 2.20 (95% CI: 1.05-4.62, P = 0.038) for the heterozygous and homozygous groups. Neither set of samples showed statistically significant interaction with smoking, although there appeared to be a trend of interaction between smoking and LOC387715 for risk of advanced AMD. CONCLUSIONS Although these data from three case-control samples support an AMD genetic risk marker harbored within LOC387715, the nested case-control data from the population-based BMES samples showed lower estimates than from the clinic-based samples. This may be because the BMES samples consisted of largely early AMD cases while the clinic-based AMD samples consisted exclusively of advanced cases.
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Siyambalapitiya S, Ibbotson V, Doane A, Ghigo E, Campbell MJ, Ross RJ. Combining growth hormone releasing hormone-arginine and synacthen testing diminishes the cortisol response. J Clin Endocrinol Metab 2007; 92:853-6. [PMID: 17192289 DOI: 10.1210/jc.2006-2140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVES The GHRH/arginine test and short synacthen test (SST) have been validated as safe alternatives to the insulin tolerance test for the assessment of the GH reserve and hypothalamic-pituitary-adrenal axis integrity, respectively. However, these two tests are usually performed separately. The objective was to see whether the synacthen and GHRH/arginine tests could be combined to save time and blood samples and minimize inconvenience to patients. PATIENTS/METHODS Twenty-four consecutive patients with adult onset pituitary disease requiring pituitary function testing were randomized to receive sequentially and in random order a SST, a GHRH/arginine test, and a combined SST and GHRH/arginine test on three different visits separated by at least 1 wk. RESULTS There was no difference in basal cortisol or ACTH values for the SST done alone or during the combined test. However, when GHRH/arginine was given with synacthen, patients had a lower peak cortisol response with a mean difference of 116 nmol/liter (95% confidence interval, 52.54 to 179.37; P < 0.001), and one patient with a normal response on the SST had a subnormal cortisol response in the combined test. Similar lower peak cortisol responses were observed in males and females with combined test. The difference between the peak cortisol responses showed no significant correlation with age (r = 0.123; P = 0.58) or with the body mass index (r = -0.376; P = 0.09). There was no difference in GH measurements between the GHRH/arginine test done alone or in combination with the SST. CONCLUSIONS Combining the SST and GHRH/arginine test results in a lower cortisol response to synacthen. For this reason, the combined test cannot be recommended to assess the integrity of cortisol and GH reserve using current diagnostic criteria.
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Chan CC, Shen D, Zhou M, Ross RJ, Ding X, Zhang K, Green WR, Tuo J. Human HtrA1 in the archived eyes with age-related macular degeneration. TRANSACTIONS OF THE AMERICAN OPHTHALMOLOGICAL SOCIETY 2007; 105:92-7; discussion 97-8. [PMID: 18427598 PMCID: PMC2258134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
PURPOSE HtrA1 belongs to the high temperature requirement factor A family of serine proteases, which are involved in protein quality control and cell fate. A single-nucleotide polymorphism (SNP), rs11200638, in the promoter of HtrA1 at chromosome 10q26 is reported as a likely causal variant for age-related macular degeneration (AMD). The SNP is located in the regulatory region and increases production of HtrA1 protein. This study investigates HtrA1 expression and SNP genotypes in archived ocular slides with AMD. METHODS Macular, nonretinal, and peripheral retinal cells were microdissected from archived slides from 57 eyes with AMD and 16 age-matched, non-AMD controls. HtrA1 rs11200638 SNP genotyping was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis. HtrA1 transcripts were measured using real-time reverse transcriptase-PCR. HtrA1 protein expression was evaluated using avidin-biotin complex immunohistochemistry. RESULTS HtrA1 (G/A) SNP was successfully genotyped in 52 AMD cases and 13 non-AMD subjects. The frequencies of the risk allele (A) were 55 of 104 (52.9%) and 8 of 26 (30.8%) in AMD and control groups, respectively. HtrA1 mRNA was detected in normal peripheral and macular retinas, higher in the periphery than maculae. HtrA1 mRNA was much higher in the macula and a lot lower in the periphery of the AMD eyes as compared to control eyes. HtrA1 protein was expressed in normal retinal vascular endothelia and retinal pigment epithelia. Intense immunoreaction against HtrA1 was found in AMD lesions, slightly more in wet than dry AMD lesions. CONCLUSION This study successfully analyzes HtrA1 SNP and transcript expression in microdissected cells from archived paraffin fixed slides. Up-regulation of HtrA1 is detected in the macular lesions of AMD eyes. The data further suggest that rs11200638 in HtrA1 promoter is associated with AMD development.
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Merza Z, Rostami-Hodjegan A, Memmott A, Doane A, Ibbotson V, Newell-Price J, Tucker GT, Ross RJ. Circadian hydrocortisone infusions in patients with adrenal insufficiency and congenital adrenal hyperplasia. Clin Endocrinol (Oxf) 2006; 65:45-50. [PMID: 16817818 DOI: 10.1111/j.1365-2265.2006.02544.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Conventional hydrocortisone therapy in adrenal insufficiency cannot provide physiological replacement. We have explored the potential of circadian delivery of hydrocortisone as proof of concept for such therapy delivered in modified-release tablet formulation. METHODS We investigated whether the circadian intravenous infusion of hydrocortisone could improve control of ACTH and androgen levels. Two healthy subjects, two patients with Addison's disease and two patients with congenital adrenal hyperplasia (CAH) were studied. RESULTS In patients on thrice daily oral hydrocortisone, peak serum cortisol levels were higher than in normal subjects and overnight levels were very low. Patients had very high plasma ACTH levels before their morning dose of hydrocortisone, both at the beginning and at the end of their conventional oral therapy: mean +/- SEM 311.8 +/- 123.2 and 311.2 +/- 85.4 ng/l, respectively. In the patients with CAH, serum 17-hydroxyprogesterone levels were also elevated: 550 and 642 nmol/l at the beginning and 550 and 777 nmol/l at the end of conventional treatment, respectively. The overall 24-h mean cortisol levels were similar for conventional oral hydrocortisone and the circadian infusion. At 0700 h, ACTH levels were much higher on conventional treatment than after circadian infusion: mean +/- SEM 311.2 +/- 85.4 vs. 70.5 +/- 45.0 ng/l, respectively (P < 0.05). The same pattern was observed in 17-hydroxyprogesterone levels, which were 550 and 777 nmol/l after conventional treatment and 3 and 64 nmol/l after circadian infusion. CONCLUSIONS In patients with poor biochemical control of Addison's disease and CAH, a 24-h circadian infusion of hydrocortisone can decrease morning ACTH and 17-hydroxyprogesterone levels to near normal.
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Tuo J, Ning B, Bojanowski CM, Lin ZN, Ross RJ, Reed GF, Shen D, Jiao X, Zhou M, Chew EY, Kadlubar FF, Chan CC. Synergic effect of polymorphisms in ERCC6 5' flanking region and complement factor H on age-related macular degeneration predisposition. Proc Natl Acad Sci U S A 2006; 103:9256-61. [PMID: 16754848 PMCID: PMC1474016 DOI: 10.1073/pnas.0603485103] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This study investigates age-related macular degeneration (AMD) genetic risk factors through identification of a functional single-nucleotide polymorphism (SNP) and its disease association. We chose ERCC6 because of its roles in the aging process, DNA repair, and ocular degeneration from the gene disruption. Bioinformatics indicated a putative binding-element alteration on the sequence containing C-6530>G SNP in the 5' flanking region of ERCC6 from Sp1 on the C allele to SP1, GATA-1, and OCT-1 on the G allele. Electrophoretic mobility shift assays displayed distinctive C and G allele-binding patterns to nuclear proteins. Luciferase expression was higher in the vector construct containing the G allele than that containing the C allele. A cohort of 460 advanced AMD cases and 269 age-matched controls was examined along with pathologically diagnosed 57 AMD and 18 age-matched non-AMD archived cases. ERCC6 C-6530>G was associated with AMD susceptibility, both independently and through interaction with an SNP (rs380390) in the complement factor H (CFH) intron reported to be highly associated with AMD. A disease odds ratio of 23 was conferred by homozygozity for risk alleles at both ERCC6 and CFH compared with homozygozity for nonrisk alleles. Enhanced ERCC6 expression was observed in lymphocytes from healthy donors bearing ERCC6 C-6530>G alleles. Intense immunostaining of ERCC6 was also found in AMD eyes from ERCC6 C-6530>G carriers. The strong AMD predisposition conferred by the ERCC6 and CFH SNPs may result from biological epistasis, because ERCC6 functions in universal transcription as a component of RNA pol I transcription complex.
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Greenfield DM, Wright J, Brown JE, Hancock BW, Davies HA, O'toole L, Eiser C, Coleman RE, Ross RJ. High incidence of late effects found in Hodgkin's lymphoma survivors, following recall for breast cancer screening. Br J Cancer 2006; 94:469-72. [PMID: 16465193 PMCID: PMC2361189 DOI: 10.1038/sj.bjc.6602974] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Assessment of late effects in a cohort of female Hodgkin's lymphoma patients treated with mantle radiotherapy, identified from the DoH breast cancer screening recall showed high mortality and frequent undiagnosed abnormalities in tissues affected by radiotherapy. With increasing age, this patient group may suffer premature cardiac and respiratory morbidity.
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Sanford LD, Yang L, Tang X, Dong E, Ross RJ, Morrison AR. Cholinergic regulation of the central nucleus of the amygdala in rats: Effects of local microinjections of cholinomimetics and cholinergic antagonists on arousal and sleep. Neuroscience 2006; 141:2167-76. [PMID: 16843604 DOI: 10.1016/j.neuroscience.2006.05.064] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2006] [Revised: 05/26/2006] [Accepted: 05/29/2006] [Indexed: 11/18/2022]
Abstract
The amygdala has emerged as an important forebrain modulator of arousal. Acetylcholine plays a role in the regulation of sleep and wakefulness, particularly rapid eye movement sleep (REM). The major cholinergic input to the amygdala comes from the basal forebrain, a region primarily linked to wakefulness. We examined sleep and the encephalogram for 8 h following bilateral microinjections into the central nucleus of the amygdala (CNA) of the cholinergic agonist, carbachol (CARB(L): 0.3 microg; CARB(H): 3.0 microg), the acetylcholinesterase inhibitor, neostigmine (NEO(L): 0.3 microg; NEO(H): 3.0 microg), the muscarinic antagonist, scopolamine (SCO(L): 0.3 microg; SCO(H): 1.0 microg), the nicotinic antagonist, mecamylamine (MEC(L): 0.3 microg; MEC(H): 1.0 microg) and saline (SAL, 0.2 microl) alone. Both doses of CARB and NEO significantly reduced REM, but did not significantly alter non-rapid eye movement sleep (NREM). Both doses of SCO significantly increased NREM, and SCO(H) also produced an initial increase in REM followed by a significant decrease. CARB(H) and NEO(H) decreased REM electroencephalogram (EEG) power in the 5.5-10 Hz band, and NEO(L) and NEO(H) decreased NREM EEG power in the 0.5-5.0 Hz band. CARB(L) decreased waking EEG power in the 0.5-5.0 Hz band, and NEO(H) decreased waking EEG power in the 5.0-10.0 Hz band. Both doses of SCO significantly increased waking EEG power in the 5.5-10.0 Hz band. Compared with SAL, MEC did not significantly alter sleep or EEG power. The reduction of REM by CARB and NEO and the alteration of sleep by SCO indicate that cholinergic regulation of the amygdala is involved in the control of arousal in rodents. In contrast, CARB microinjections into CNA increase REM in cats, though the reasons for the species difference are not known. The results are discussed in the context of anatomical inputs and species differences in the cholinergic regulation of CNA.
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McCloy U, Ryan MA, Pencharz PB, Ross RJ, Cunnane SC. A comparison of the metabolism of eighteen-carbon 13C-unsaturated fatty acids in healthy women. J Lipid Res 2003; 45:474-85. [PMID: 14679164 DOI: 10.1194/jlr.m300304-jlr200] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Altered use of different dietary fatty acids may contribute to several chronic diseases, including obesity, noninsulin-dependent diabetes mellitus, and cardiovascular disease. However, few comparative data are available to support this link, so the goal of the present study was to compare the metabolism of [(13)C]oleate, [(13)C]alpha-linolenate, [(13)C]elaidate, and [(13)C]linoleate through oxidation and incorporation into plasma lipid fractions and adipose tissue. Each tracer was given as a single oral bolus to six healthy women. Samples were collected over 8 days, and (13)C was analyzed using isotope ratio mass spectrometry. At 9 h postdose, cumulative oxidation was similar for [(13)C]elaidate, [(13)C]oleate, and [(13)C]alpha-linolenate (19 +/- 1%, 20 +/- 4%, and 19 +/- 3% dose, respectively). Significantly lower oxidation of [(13)C]linoleate (12 +/- 4% dose; P < 0.05) was accompanied by its higher incorporation into plasma phospholipids and cholesteryl esters. Abdominal adipose tissue was enriched with [(13)C]alpha-linolenate, [(13)C]elaidate, or [(13)C]linoleate within 6 h. The percentage linoleate in plasma phospholipids correlated positively with [(13)C]linoleate and [(13)C]elaidate oxidation, indicating a potential role of background diet. Conversion of [(13)C]linoleate and [(13)C]alpha-linolenate to longer chain polyunsaturates was a quantitatively minor route of utilization.
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Savage DB, Agostini M, Barroso I, Gurnell M, Luan J, Meirhaeghe A, Harding AH, Ihrke G, Rajanayagam O, Soos MA, George S, Berger D, Thomas EL, Bell JD, Meeran K, Ross RJ, Vidal-Puig A, Wareham NJ, O'Rahilly S, Chatterjee VKK, Schafer AJ. Erratum: Digenic inheritance of severe insulin resistance in a human pedigree. Nat Genet 2002. [DOI: 10.1038/ng0902-211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Paquette LA, Nitz TJ, Ross RJ, Springer JP. Ingenane synthetic studies. An expedient approach to highly oxygenated ABC subunits of ingenol via reductive dialkylative annulation and .alpha.,.beta.-epoxy ketone photoisomerization. J Am Chem Soc 2002. [DOI: 10.1021/ja00317a043] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Paquette LA, Ross RJ, Shi YJ. Regioselective routes to nucleophilic optically active 2- and 3-carene systems. J Org Chem 2002. [DOI: 10.1021/jo00292a039] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ross RJ, Paquette LA. Ingenane synthetic studies. Stereocontrolled introduction of all oxygenated and unsaturated centers in an ingenol prototype. J Org Chem 2002. [DOI: 10.1021/jo00233a048] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Paquette LA, Ross RJ, Springer JP. Stereocontrolled construction of an ingenol prototype having a complete array of oxygenated and unsaturated centers. J Am Chem Soc 2002; 110:6192-204. [DOI: 10.1021/ja00226a039] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Paquette LA, Peterson JR, Ross RJ. Migratory selectivity in the ring expansion of .alpha.,.beta.-unsaturated cyclic ketones via .beta.-hydroxy selenides. J Org Chem 2002. [DOI: 10.1021/jo00225a043] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sanford LD, Nassar P, Ross RJ, Schulkin J, Morrison AR. Prolactin microinjections into the amygdalar central nucleus lead to decreased NREM sleep. SLEEP RESEARCH ONLINE : SRO 2001; 1:109-13. [PMID: 11382866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Prolactin administered systemically, intracerebroventricularly or locally into the lateral hypothalamus enhances rapid eye movement sleep (REM) when given diurnally and decreases REM when given nocturnally. The amygdala is being recognized as an important modulator of behavioral state, and the central nucleus of the amygdala (CNA) has a high concentration of prolactin fibers and receptors. We microinjected prolactin (10, 100, 250 ng/0.2 microliter saline) or saline alone into CNA of rats and measured the effect on behavioral state. Prolactin produced a dose-dependent decrease in non-REM (NREM), with the effect becoming significant at the high (250 ng) dose. REM was not significantly affected at any dosage. The results indicate a role for prolactin in CNA in the control of NREM. The results are discussed in terms of the amygdala having a broad role in the regulation of behavioral state.
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Sanford LD, Hunt WK, Ross RJ, Pack AI, Morrison AR. Central administration of a 5-HT2 receptor agonist and antagonist: lack of effect on rapid eye movement sleep and pgo waves. SLEEP RESEARCH ONLINE : SRO 2001; 1:80-6. [PMID: 11382861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Serotonin (5-HT) has a role in regulating behavioral state and controlling the production of ponto-geniculo-occipital (PGO) waves, though the exact mechanism of action is not known. The most prevailing explanation is that 5-HT exerts its influence on behavioral state and PGO waves by inhibiting and disinhibiting cholinergic cells in the pedunculopontine tegmentum (PPT) and laterodorsal tegmentum (LDT), which have been implicated in their generation. Recent work in rats has demonstrated 5-HT2 receptors on most cholinergic cells in PPT/LDT. We microinfused the relatively specific 5-HT2 agonist, DOI (1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane), the relatively specific 5-HT2 antagonist, ketanserin, and the nonspecific 5-HT antagonist, methysergide, locally into the peribrachial region of PPT in cats and monitored behavioral state and PGO waves. Neither drug significantly affected behavioral state or PGO wave activity. These results suggest that 5-HT2 receptors associated with cholinergic cells are minimally involved in the control of behavioral state and, together with the recent findings of others, suggest that 5-HT may not modulate PGO wave generation via direct action on cholinergic neurons in PPT/LDT, a departure from the long-held but minimally-tested view.
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Zarkesh-Esfahani H, Pockley G, Metcalfe RA, Bidlingmaier M, Wu Z, Ajami A, Weetman AP, Strasburger CJ, Ross RJ. High-dose leptin activates human leukocytes via receptor expression on monocytes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:4593-9. [PMID: 11591788 DOI: 10.4049/jimmunol.167.8.4593] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Leptin is capable of modulating the immune response. Proinflammatory cytokines induce leptin production, and we now demonstrate that leptin can directly activate the inflammatory response. RNA expression for the leptin receptor (Ob-R) was detectable in human PBMCs. Ob-R expression was examined at the protein level by whole blood flow cytometry using an anti-human Ob-R mAb 9F8. The percentage of cells expressing leptin receptor was 25 +/- 5% for monocytes, 12 +/- 4% for neutrophils, and 5 +/- 1% for lymphocytes (only B lymphocytes). Incubation of resting PBMCs with leptin induced rapid expression of TNF-alpha and IL-6 mRNA and a dose-dependent production of TNF-alpha and IL-6 by monocytes. Incubation of resting PBMCs with high-dose leptin (250 ng/ml, 3-5 days) induced proliferation of resting cultured PBMCs and their secretion of TNF-alpha (5-fold), IL-6 (19-fold), and IFN-gamma (2.5-fold), but had no effect on IL-4 secretion. The effect of leptin was distinct from, and additive to, that seen after exposure to endotoxin or activation by the mixed lymphocyte reaction. In conclusion, Ob-R is expressed on human circulating leukocytes, predominantly on monocytes. At high doses, leptin induces proinflammatory cytokine production by resting human PBMCs and augments the release of these cytokines from activated PBMCs in a pattern compatible with the induction of Th1 cytokines. These results demonstrate that leptin has a direct effect on the generation of an inflammatory response. This is of relevance when considering leptin therapy and may partly explain the relationship among leptin, proinflammatory cytokines, insulin resistance, and obesity.
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Maamra M, Bidlingmaier M, Postel-Vinay MC, Wu Z, Strasburger CJ, Ross RJ. Generation of human soluble leptin receptor by proteolytic cleavage of membrane-anchored receptors. Endocrinology 2001; 142:4389-93. [PMID: 11564702 DOI: 10.1210/endo.142.10.8442] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The leptin receptor (ObR) exists in multiple isoforms. In rodents, a soluble isoform is generated by alternative splicing; but in humans, there is no mRNA encoding soluble receptor (leptin binding protein). We investigated the hypothesis that human leptin binding protein can be generated by proteolytic cleavage of membrane-anchored leptin receptors (ObRb and ObRa). Leptin binding protein of similar size to that previously detected in human serum was detected by HPLC in medium of cells transfected with ObRa. ObRa exhibited higher expression at the cell surface than ObRb and generated greater levels of leptin binding protein. Ligand-mediated immunofunctional and immunofluorometric assays revealed that the leptin binding protein in medium bound both leptin and an ObR-specific antibody and that the level of leptin binding protein correlated with receptor expression at the cell surface. Phorbol 12-myristate-13-acetate and N-ethylmaleimide increased the accumulation of leptin binding protein, an indication that the production of leptin binding protein was up-regulated by PKC and sulfhydryl group activation. The protease inhibitors, TNFalpha protease inhibitor 1 and Immunex compound 2, could inhibit the production of leptin binding protein, indicating that the enzyme responsible for leptin binding protein cleavage belongs to the metalloprotease family. In conclusion, human leptin binding protein is generated by proteolytic cleavage of membrane-anchored leptin receptor by a metalloprotease.
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Savage MO, Camacho-Hübner C, Dunger DB, Ranke MB, Ross RJ, Rosenfeld RG. Is there a medical need to explore the clinical use of insulin-like growth factor I? Growth Horm IGF Res 2001; 11 Suppl A:S65-S69. [PMID: 11527091 DOI: 10.1016/s1096-6374(01)80011-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Cloning of the insulin-like growth factor I (IGF-I) gene led to the development in 1987 of recombinant IGF-I available for clinical use. Trials were started targeting endocrine, metabolic and neurological disorders, and beneficial results have been demonstrated in IGF-I deficiency states caused by IGF-I gene deletion and growth hormone (GH) receptor deficiency, type 1 and type 2 diabetes mellitus, and severe insulin resistance syndromes. Results of equivocal benefit have also been reported in osteoporosis and amyotrophic lateral sclerosis. Recent encouraging data using the IGF-I-IGF-binding protein 3 (IGFBP-3) complex in diabetes mellitus suggest that this preparation may eventually replace recombinant free IGF-I. The lack of an established therapeutic indication for IGF-I has resulted in its supplies being severely limited. It will probably be decided during the next decade whether use of IGF-I or the IGF-I-IGFBP-3 complex becomes firmly established as an accepted endocrine therapy.
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Quinton ND, Lee AJ, Ross RJ, Eastell R, Blakemore AI. A single nucleotide polymorphism (SNP) in the leptin receptor is associated with BMI, fat mass and leptin levels in postmenopausal Caucasian women. Hum Genet 2001; 108:233-6. [PMID: 11354636 DOI: 10.1007/s004390100468] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The human leptin (obese) receptor gene contains a number of single nucleotide polymorphisms, including GLN223ARG, which changes an amino acid on the extracellular region common to all isoforms of the receptor. Here, we demonstrate that, in postmenopausal Caucasian women, genotypes at that locus are associated with differences in body mass index (BMI), fat mass and serum leptin levels. Measurement of serum leptin-binding activity indicates that this may reflect changed receptor function associated with genotype. These observations indicate that functional variations in the leptin receptor gene are important factors in the regulation of adiposity and BMI.
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Johnson TS, O'Leary M, Justice SK, Maamra M, Zarkesh-Esfahani SH, Furlanetto R, Preedy VR, Hinds CJ, El Nahas AM, Ross RJ. Differential expression of suppressors of cytokine signalling genes in response to nutrition and growth hormone in the septic rat. J Endocrinol 2001; 169:409-15. [PMID: 11312157 DOI: 10.1677/joe.0.1690409] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
GH treatment during critical illness and sepsis may increase mortality. A family of negative regulators of cytokine signalling, the suppressors of cytokine signalling (SOCS), have been characterised. SOCS provide a mechanism for cross-talk between the cytokine receptors, including GH. Here, we have investigated the impact of nutrition and GH treatment on GH receptor, SOCS1, SOCS-2, SOCS-3 and cytokine-inducible SH2-containing protein (CIS) hepatic mRNA expression in a rat model of sepsis, caecal ligation and puncture (CLP). Four groups of rats were studied: control (food given ad libitum, n=7), CLP only (n=8), CLP and total parenteral nutrition (TPN) (n=9), and CLP, TPN and GH (n=10). CLP rats underwent surgery and 18 h later received saline or TPN or TPN+GH for 6 h before they were killed. Serum IGF-I levels were lower in all CLP groups (P<0.001). The combination of TPN and GH treatment increased IGF-I levels compared with the saline-treated CLP rats (P<0.01), but IGF-I levels remained lower than control animals (P<0.001). GH receptor and GH-binding protein expression in liver was reduced in animals subjected to CLP and was unaffected by nutrition or GH treatment. Hepatic SOCS-1 was detectable in normal rats, induced in all CLP animals but was unaffected by nutrition and GH. Hepatic SOCS-2 expression was difficult to detect in normal and CLP rats but was greatly induced in CLP rats treated with GH. Hepatic SOCS-3 expression was only just detectable in the control group but was elevated in all CLP groups and unaffected by nutrition and GH. Hepatic CIS expression was difficult to detect in normal rats, was not induced by CLP but was induced by both nutrition and GH. In conclusion, CLP induced low IGF-I levels associated with increased expression of SOCS-1 and SOCS-3, both of which are known to inhibit GH receptor signalling. GH induced SOCS-2 and CIS in the CLP rat despite resistance with respect to IGF-I generation, and parenteral feeding induced CIS in the CLP rat. Thus, there is potential for a complex interaction between GH and cytokine signalling at the level of SOCS expression whereby the inflammatory response may alter GH signalling and GH may influence the inflammatory response.
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Sanford LD, Silvestri AJ, Ross RJ, Morrison AR. Influence of fear conditioning on elicited ponto-geniculo-occipital waves and rapid eye movement sleep. Arch Ital Biol 2001; 139:169-83. [PMID: 11330199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The amygdala plays a central role in fear conditioning, a model of anticipatory anxiety. It has massive projections to brainstem regions involved in rapid eye movement sleep (REM) and ponto-geniculo-occipital (PGO) wave generation. PGO waves occur spontaneously in REM or in response to stimuli. Electrical stimulation of the central nucleus of the amygdala enhances spontaneous PGO wave activity during REM and the amplitude of both the acoustic startle response and the elicited PGO wave (PGOE), a neural marker of alerting. This study examined the effects of fear conditioning on REM and on PGOE. On conditioning days, the number of REM episodes, the average REM duration and the REM percentage were decreased while REM latency was increased. The presentation of auditory stimuli in the presence of a light conditioned stimulus produced PGOE of greater amplitudes. The results suggest that fear, most likely involving the amygdala, can influence REM and brainstem alerting mechanisms.
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