Vector-mediated l-3,4-dihydroxyphenylalanine delivery reverses motor impairments in a primate model of Parkinson's disease.

Ever since its introduction 40 years ago l-3,4-dihydroxyphenylalanine (l-DOPA) therapy has retained its role as the leading standard medication for patients with Parkinson's disease. With time, however, the shortcomings of oral l-DOPA treatment have become apparent, particularly the motor fluctuations and troublesome dyskinetic side effects. These side effects, which are caused by the excessive swings in striatal dopamine caused by intermittent oral delivery, can be avoided by delivering l-DOPA in a more continuous manner. Local gene delivery of the l-DOPA synthesizing enzymes, tyrosine hydroxylase and guanosine-tri-phosphate-cyclohydrolase-1, offers a new approach to a more refined dopaminergic therapy where l-DOPA is delivered continuously at the site where it is needed i.e. the striatum. In this study we have explored the therapeutic efficacy of adeno-associated viral vector-mediated l-DOPA delivery to the putamen in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated rhesus monkeys, the standard non-human primate model of Parkinson's disease. Viral vector delivery of the two enzymes, tyrosine hydroxylase and guanosine-5'-tri-phosphate-cyclohydrolase-1, bilaterally into the dopamine-depleted putamen, induced a significant, dose-dependent improvement of motor behaviour up to a level identical to that obtained with the optimal dose of peripheral l-DOPA. Importantly, this improvement in motor function was obtained without any adverse dyskinetic effects. These results provide proof-of-principle for continuous vector-mediated l-DOPA synthesis as a novel therapeutic strategy for Parkinson's disease. The constant, local supply of l-DOPA obtained with this approach holds promise as an efficient one-time treatment that can provide long-lasting clinical improvement and at the same time prevent the appearance of motor fluctuations and dyskinetic side effects associated with standard oral dopaminergic medication.

Biopsychosocial Influence on Shoulder Pain: Influence of Genetic and Psychological Combinations on Twelve-Month Postoperative Pain and Disability Outcomes.

OBJECTIVE: To identify novel combinations of genetic and psychological factors that predicted 12-month postoperative pain and disability outcomes following arthroscopic shoulder surgery. METHODS: A prospective presurgical cohort (n = 150) was recruited to complete validated psychological questionnaires and have their DNA collected from saliva. DNA was genotyped for a priori selected genes involved with pain modulation (ADRB2, OPRM1, AVPR1A, GCH1, and KCNS1) and inflammation (IL1B, TNF/LTA, and IL6). The outcome measures of interest were the Brief Pain Inventory and Disabilities of the Arm, Shoulder, and Hand questionnaire. Followup for the cohort was at 3, 6, and 12 months postoperatively. After controlling for age, sex, race, and preoperative status, genetic and psychological factors were entered as main effects and interaction terms in separate general linear models for predicting postoperative pain and disability outcomes. RESULTS: Seven interactions involving pain-modulatory genes were identified. Three provided strong statistical evidence for different outcomes, including KCNS1 and kinesiophobia for preoperative pain intensity, ADRB2 and depressive symptoms for postoperative course, and GCH1 and anxiety symptoms for 12-month pain-intensity outcome. Ten interactions involving inflammatory genes were identified. Three provided strong statistical evidence for the 12-month postoperative course outcome, including 2 different IL6 single-nucleotide polymorphism and pain catastrophizing, and IL6 and depressive symptoms. CONCLUSION: The current study identified novel genetic and psychological interactions that can be used in future studies to further understand the development of persistent postoperative pain and investigate the effectiveness of tailored treatment.

Urinary neopterin: an immune activation marker in mesangial proliferative glomerulonephritis.

BACKGROUND: To clarify in vivo neopterin expression within the human kidney and its clinical role as a biomarker for immune complex-mediated mesangial proliferative glomerulonephritis (mesPGN) in children. METHODS: We examined neopterin expression within the kidneys of 14 patients with mesPGN and five patients with minimal changes. We also measured the serum and urinary neopterin levels in fourteen patients with mesPGN and sixteen age-matched healthy controls and correlated the histological findings and clinical features. RESULTS: Neopterin expression was observed within the distal tubular epithelial cells. It was induced within the glomerular endothelial cells and infiltrated CD68-positive macrophages in the glomeruli and interstitial areas. Furthermore, urinary neopterin levels were significantly elevated and positively correlated with histopathological findings and the degree of proteinuria. CONCLUSIONS: These findings indicate that increased urinary neopterin may reflect macrophage activation and active inflammation within the kidney in immune complex-mediated glomerulonephritis. Neopterin may thus represent a useful biomarker of immune complex-mediated glomerulonephritis in the clinical setting.

Cilostazol inhibits cytokine-induced tetrahydrobiopterin biosynthesis in human umbilical vein endothelial cells.

AIMS: Cilostazol, a type III phosphodiesterase inhibitor, is utilized for the treatment of intermittent claudication and is considered to have the beneficial effects against the atherogenic process. In the present study, we examined the effects of cilostazol on BH(4) biosynthesis in HUVEC treated with a mixture of the pro-inflammatory cytokines IFN-γ and TNF-α. METHODS: Isolated HUVECs were grown to confluence and treated with IFN-γ (300 units/mL) and TNF-α (300 units/mL) for 16 h in order to stimulate BH(4) biosynthesis. The BH(4) levels were measured by HPLC. The mRNA expression of GTP cyclohydrolase I (GTPCH), the rate-limiting enzyme of BH(4) biosynthesis, and GTPCH feedback regulatory protein (GFRP) were quantified by real-time PCR. The GTPCH protein expression was assessed by western blot analysis. RESULTS: Cilostazol significantly reduced the BH(4) levels in cytokine-stimulated HUVEC. Cilostazol produced a concomitant increase in the cAMP levels in HUVEC. Cilostazol decreased the GTPCH activity as well as the expression of GTPCH mRNA and protein. 8-bromo-cAMP (8Br-cAMP), a cell-permeable cAMP analogue, did not reproduce the effects of cilostazol. Cilostazol did not affect the cytokine-induced inhibition of GFRP mRNA expression. CONCLUSIONS: We conclude that cilostazol inhibited cytokine-stimulated BH(4) biosynthesis via a cAMP-independent mechanism in HUVEC. Our data indicate that cilostazol reduced GTPCH activity and did so by suppressing the GTPCH protein levels.

Select nutrients in the ovine uterine lumen. V. Nitric oxide synthase, GTP cyclohydrolase, and ornithine decarboxylase in ovine uteri and peri-implantation conceptuses.

Nitric oxide (NO) and polyamines are critical for implantation and development of conceptuses (embryo and extraembryonic membranes), but mechanisms regulating their biosynthesis in uteri and conceptuses are largely unknown. This study determined the effects of the estrous cycle, pregnancy, progesterone, and interferon tau (IFNT) on expression of NO synthases (NOS1, NOS2, and NOS3), guanosine triphosphate (GTP) cyclohydrolase (GCH1, the key enzyme in de novo synthesis of tetrahydrobiopterin, a cofactor for NO production), and ornithine decarboxylase (ODC1) in uterine endometria in cyclic ewes (Days 10-16) and pregnant ewes (Days 10-20). The mRNAs and proteins for NOS1 and ODC1 were most abundant in uterine luminal (LE) and superficial glandular (sGE) epithelia, and abundance was affected by day of estrous cycle and early pregnancy. NOS2, GCH1, and NOS3 mRNAs were detected in very low abundance in uterine epithelia and stromal cells in both cyclic and pregnant ewes. NOS1 mRNA also was expressed very weakly in conceptuses, whereas NOS3 mRNA was abundant in the trophectoderm and endoderm of conceptuses, as were total NOS1 and NOS3 proteins, inhibitory p-NOS1 protein, and stimulatory p-NOS3 protein. GCH1 mRNA was abundant in the trophectoderm and endoderm of conceptuses between Days 13 and 15 of pregnancy and then decreased thereafter, whereas ODC1 mRNA abundance increased in conceptuses between Days 13 and 18 of pregnancy. GCH1 protein was localized primarily in the nuclei of trophectoderm and endoderm, and its abundance decreased after Day 14 of pregnancy, whereas ODC1 protein was more abundant in the trophectoderm than in the endoderm between Days 13 and 18 of pregnancy. Progesterone stimulated NOS1 and GCH1 expression in LE/sGE and glandular epithelia, whereas IFNT inhibited NOS1 expression in these cell types. Thus, biosynthesis of NO and polyamines in ovine uterine endometria and conceptuses is potentially regulated at transcriptional, translational, and posttranslational levels to favor conceptus development and implantation.

Role of angiotensin II on dihydrofolate reductase, GTP-cyclohydrolase 1 and nitric oxide synthase expressions in renal ischemia-reperfusion.

BACKGROUND: The present study was conducted to investigate the role of renal ischemia-reperfusion (IR) and angiotensin II (ANG II) on mRNA and protein levels of renal dihydrofolate reductase (DHFR), GTP-cyclohydrolase 1 (GTP- CH 1), and endothelial and inducible nitric oxide synthase (eNOS and iNOS, respectively). METHODS: Male Wistar rats were sham operated or received IR (30 min occlusion, and reperfusion for 1 day). Each group was treated separately with water, angiotensin-converting enzyme inhibitor (ACEI) and ANG II receptor type 1 blocker (ARB) for 1 day before the sham operation or IR, and continuously for 1 day after the operation. The mRNA and protein levels were detected by RT-PCR and Western blot, respectively. RESULTS: IR decreased DHFR mRNA and protein levels (p < 0.01), both of which were restored by ACEI or ARB, whereas GTP-CH 1 expression was unaltered. IR suppressed eNOS dimer while enhancing the monomer (p < 0.01). IR augmented iNOS mRNA, total iNOS protein and iNOS monomer (all p < 0.01) which were attenuated by ACEI or ARB. CONCLUSION: Our study is the first to demonstrate that the heightened ANG II in IR, via stimulation of ANG II receptor type 1, suppresses DHFR and eNOS dimer, while activating both iNOS mRNA and protein levels.

2,4-Diamino-6-hydroxypyrimidine (DAHP) suppresses cytokine-induced VCAM-1 expression on the cell surface of human umbilical vein endothelial cells in a BH(4)-independent manner.

2,4-Diamino-6-hydroxypyrimidine (DAHP) is considered a specific inhibitor of BH(4) biosynthesis and is widely used in order to elucidate the possible biological function of BH(4) in various cells. In the present study, we found that both the synthesis of tetrahydrobiopterin (BH(4)) and expression of vascular cell adhesion molecule 1 (VCAM-1) were increased in human umbilical vein endothelial cells (HUVEC) treated with proinflammatory cytokines. Thus we examined the effects of DAHP to clarify whether BH(4) might be involved in the expression of VCAM-1 in HUVEC. DAHP reduced the levels of both BH(4) and VCAM-1 induced by TNF-alpha and IFN-gamma. However, the dose-response curves of DAHP for the suppression of the VCAM-1 level and that of BH(4) level were markedly different. Supplementation with sepiapterin failed to restore the depressed VCAM-1 level, although it completely restored the BH(4) level. Furthermore, DAHP significantly reduced the VCAM-1 level under the experimental conditions using TNF-alpha alone, which failed to induce BH(4) production. Taken together, these results indicate that DAHP inhibited the expression of VCAM-1 in a BH(4)-independent manner in HUVEC. In the present study, we also found that DAHP significantly suppressed the accumulation of cytokine-induced NF-kappaB (p65) in the nucleus as well as the mRNA levels of VCAM-1 and GTP cyclohydrolase I (GTPCH), the rate-limiting enzyme of BH(4) synthesis. The data obtained in this study suggest that DAHP reduced VCAM-1 and GTPCH protein synthesis at least partially via suppressing the NF-kappaB level in the nucleus of HUVEC.

A specific role for eNOS-derived reactive oxygen species in atherosclerosis progression.

OBJECTIVE: When the availability of tetrahydrobiopterin (BH4) is deficient, endothelial nitric oxide synthase (eNOS) produces superoxide rather than NO (uncoupled eNOS). We have shown that the atherosclerotic lesion size was augmented in apolipoprotein E-deficient (ApoE-KO) mice overexpressing eNOS because of the enhanced superoxide production. In this study, we addressed the specific importance of uncoupled eNOS in atherosclerosis, and the potential mechanistic role for specific versus nonspecific antioxidant strategies in restoring eNOS coupling. METHODS AND RESULTS: We crossed mice overexpressing eNOS in the endothelium (eNOS-Tg) with mice overexpressing GTP-cyclohydrolase I (GCH), the rate-limiting enzyme in BH4 synthesis, to generate ApoE-KO/eNOS-Tg/GCH-Tg mice. As a comparison, ApoE-KO/eNOS-Tg mice were treated with vitamin C. Atherosclerotic lesion formation was increased in ApoE-KO/eNOS-Tg mice compared with ApoE-KO mice. GCH overexpression in ApoE-KO/eNOS-Tg/GCH-Tg mice increased vascular BH4 levels and reduced plaque area. This reduction was associated with decreased superoxide production from uncoupled eNOS. Vitamin C treatment failed to reduce atherosclerotic lesion size in ApoE-KO/eNOS-Tg mice, despite reducing overall vascular superoxide production. CONCLUSION: In contrast to vitamin C treatment, augmenting BH4 levels in the endothelium by GCH overexpression reduced the accelerated atherosclerotic lesion formation in ApoE-KO/eNOS-Tg mice, associated with a reduction of superoxide production from uncoupled eNOS.

GTP cyclohydrolase feedback regulatory protein controls cofactor 6-tetrahydrobiopterin synthesis in the cytosol and in the nucleus of epidermal keratinocytes and melanocytes.

(6R)-L-erythro 5,6,7,8 tetrahydrobiopterin (6BH4) is crucial in the hydroxylation of L-phenylalanine-, L-tyrosine-, and L-tryptophan-regulating catecholamine and serotonin synthesis as well as tyrosinase in melanogenesis. The rate-limiting step of 6BH4 de novo synthesis is controlled by guanosine triphosphate (GTP) cyclohydrolase I (GTPCHI) and its feedback regulatory protein (GFRP), where binding of L-phenylalanine to GFRP increases enzyme activities, while 6BH4 exerts the opposite effect. Earlier it was demonstrated that the human epidermis holds the full capacity for autocrine 6BH4 de novo synthesis and recycling. However, besides the expression of epidermal mRNA for GFRP, the presence of a functioning GFRP feedback has never been shown. Therefore, it was tempting to investigate whether this important mechanism is present in epidermal cells. Our results identified indeed a functioning GFRP/GTPCHI axis in epidermal keratinocytes and melanocytes in the cytosol, adding the missing link for 6BH4 de novo synthesis which in turn controls cofactor supply for catecholamine and serotonin biosynthesis as well as melanogenesis in the human epidermis. Moreover, GFRP expression and GTPCHI activities have been found in the nucleus of both cell types. The significance of this result warrants further investigation.

The assays of activities and function of TH, AADC, and GCH1 and their potential use in ex vivo gene therapy of PD.

In the past decades, there have been numerous studies in the gene therapy for Parkinson's disease (PD), especially in delivering genes of enzymes for dopamine (DA) synthesis. Gene therapy in PD appears to be at the brink of the clinical study phase. However, there are many questions that need to be solved before this approach can be contemplated clinically, especially the question about the control of DA production because too much DA could cause toxicity. Until recently, few studies have investigated the relation between DA production and PD improvement and respective expressed human tyrosine hydroxylase (hTH), human GTP-cyclohydrolase 1 (hGCH1), and human aromatic acid decarboxylase (hAADC) in ex vivo gene therapy for PD. Now, we have developed a simple, fast, and reliable method to assay the activities of TH and AADC and have provided the possibility of ex vivo gene therapy for PD by genetically modifying cells with separate hTH, hGCH1, and hAADC genes. Using the method, we found though hTH, hGCH1, and hAADC genes were expressed, respectively, they could fulfil the function of DA synthesis by incubating together in vitro, and more DA was synthesized in vitro when hTH, hGCH1, and hAADC genes were expressed together rather than hTH and hAADC genes expressed or hTH expressed. The result suggests that we could easily control DA production in ex vivo gene therapy before transplantation. By combining this method and microdialysis, we also could further investigate the DA production in vitro and in vivo and then decide the optimal number and ratio of different transduced cells to improve the therapy of PD. Thus, the method has potential use in ex vivo gene therapy of PD.