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A triple-transgenic (tyrosine hydroxylase/dopamine decarboxylase/GTP cyclohydrolase 1, TH/DDC/GCH1) bone marrow mesenchymal stem cell line (BMSCs) capable of stably synthesizing dopamine (DA) transmitters were established to provide experimental evidence for the clinical treatment of Parkinson's disease (PD) by using this cell line. The DA-BMSCs cell line that could stably synthesize and secrete DA transmitters was established by using the triple transgenic recombinant lentivirus. The triple transgenes (TH/DDC/GCH1) expression in DA-BMSCs was detected using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and immunofluorescence. Moreover, the secretion of DA was tested by enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). Chromosome G-banding analysis was used to detect the genetic stability of DA-BMSCs. Subsequently, the DA-BMSCs were stereotactically transplanted into the right medial forebrain bundle (MFB) of Parkinson's rat models to detect their survival and differentiation in the intracerebral microenvironment of PD rats. Apomorphine (APO)-induced rotation test was used to detect the improvement of motor dysfunction in PD rat models with cell transplantation. The TH, DDC and GCH1 were expressed stably and efficiently in the DA-BMSCs cell line, but not expressed in the normal rat BMSCs. The concentration of DA in the cell culture supernatant of the triple transgenic group (DA-BMSCs) and the LV-TH group was extremely significantly higher than that of the standard BMSCs control group (P < 0.000 1). After passage, DA-BMSCs stably produced DA. Karyotype G-banding analysis showed that the vast majority of DA-BMSCs maintained normal diploid karyotypes (94.5%). Moreover, after 4 weeks of transplantation into the brain of PD rats, DA-BMSCs significantly improved the movement disorder of PD rat models, survived in a large amount in the brain microenvironment, differentiated into TH-positive and GFAP-positive cells, and upregulated the DA level in the injured area of the brain. The triple-transgenic DA-BMSCs cell line that stably produced DA, survived in large numbers, and differentiated in the rat brain was successfully established, laying a foundation for the treatment of PD using engineered culture and transplantation of DA-BMSCs.
Subject(s)
Rats , Animals , Dopamine , Parkinson Disease/metabolism , Mesenchymal Stem Cells/metabolism , Cell Line , Brain/metabolism , Cell Differentiation , Mesenchymal Stem Cell TransplantationABSTRACT
RESUMEN Las distonías que responden a levodopa (DRD, siglas en inglés) abarcan un grupo de distonías primarias, causadas por deficiencias enzimáticas en la vía metabólica de las aminas y, por definición, comparten como característica principal su respuesta favorable y sostenida a levodopa. Existen hasta seis genes asociados a DRD, siendo el gen GCH1 el más frecuentemente involucrado. La presentación típica de esta entidad se caracteriza por su aparición en la niñez, distonía de inicio en miembros inferiores con fluctuación diurna, leve parkinsonismo y respuesta clara a dosis bajas de levodopa. Se incluye una búsqueda sistemática de la literatura con casos de DRD publicados en Latinoamérica.
SUMMARY Dopa-responsive dystonia (DRD) encompasses a heterogenous group of primary dystonias, caused by enzymatic deficiencies across the amines pathway and, by definition, show as their main characteristic a favorable and sustained response to levodopa. There are up to 6 genes associated with DRD, including pathogenic variants of the GCH1 gene as the most frequently involved. The typical presentation of DRD is characterized by start in childhood, lower limb-onset dystonia with daytime fluctuation, mild parkinsonism, and a sustained response to low doses of levodopa. A systematic literature search on DRD reported cases in Latin America is presented.
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Guanosine triphosphate cyclohydrolase (GTP cyclohydrolase,Gch) is a protease with a GTP- cyclohydro domain, which is widely found in vertebrates and invertebrates.Mammals and birds only have Gch 1.In teleost and amphibian, other two paralogs (Gch2 and Gch3) also exists besides Gchl, which also displayed functional differences.Gch is a rate-limiting enzyme that ultimately synthesized the tetrahydrobiopterin (BH4) using guanosine triphosphate as a substrate.BH4 is an essential coenzyme of aromatic amino acid hydroxylase and contributes to the synthesis of various hormones and neurotransmitters.The Gch is an initial step in the catalysis of various pterin biosynthesis and plays important roles in a series of physiological and pathological processes, such as skin pigmentation, ocular pigmentation, methotrexate, folic acid, and tetrahydrobiopterin.The physiological function of Gch is inextricably linked to the biosynthesis of BH4.As the only rate-limiting enzyme in BH4 biosynthesis, the activity of Gch is a useful indicator for the development of neurons and pigment cells.Besides, it is also an important marker of pigment synthesis and neurotransmitter biosynthesis.Nowadays, the functions of Geh in pathogenesis of tumor and cardiovascular diseases have been widely concerned, while the researches on the pigmentation and color formation are mainly concentrated in insects, and rarely in teleost.Therefore, this article summarized the characteristics of Gch genes, protein and the functions of Gch in fish coloration, which has important guiding significance for further illustration the mechanism of Gch in teleost pigmentation and fish color genetic improvements.
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Guanosine triphosphate cyclohydrolase 1 (GTPCH1) is a protein encoded by the GCH1 gene,which catalyze GTP to tetrahydrofolinine (BH4) under physiological condition.BH4 is a coenzyme of aromatic amino acid hydroxylase and a cofactor of nitric oxide synthases.BH4 involves in the synthesis of various hormones and neurotransmitters and plays an important role in a series of pathophysiological processes in vivo.Recent studies showed that GTPCH1 is involved in the pathogenesis of neuropathic pain,doparesponsive dystonia,cancer and cardiovascular diseases.In this review,we will discuss the role of GTPCH1 in those diseases mentioned above.
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Neuropathic pain is one of the most common chronic pain in clinic, and its treatment has always been a global difficulty, mainly because its pathogenesis is unknown. GTP cyclohydrolase 1 (GCH1) mediated neuropathic pain by regulating inflammatory cytokines. Besides, GCH1 is also the main speed limit in the process of tetrahydrobiopterin (BH4) enzyme synthesis. BH4 is a necessary cofactor for the synthesis of various inflammatory factors and neurotransmitters. In the study of its relationship with pain, it was found that when the GCH1 gene was silent, the pain was relieved and the expression of BH4 decreased. The results suggest that GCH1 and BH4 have a certain relationship with neuropathic pain.
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Objective To evaluate the clinical features and guanosine triphosphate cyclohydrolase 1 (GCH-1) gene mutation in a family with dopa-responsive dystonia (DRD).Methods The clinical features of this family were collected and their peripheral blood samples were screened for mutation in GCH-1 gene using PCR and DNA direct sequencing.Results The clinical features among each patient in this family were different.But all affected family members had quite a good response to levodopa treatment without significant adverse reactions.DNA test showed an AT deletion mutation at point of 631-632 in the 6th exon of GCH-1 gene in 5 affected members and 1 asymptomatic immediate family member.Conclusions Clinical heterogeneity is an important characteristic of DRD and clinical symptoms vary intra-families.Same gene type may cause different phenotype and not all carriers are patients.The deletion mutation at point of 631-632 in the 6th exon of GCH-1 gene should be considered as a pathogenic mutation for DRD.
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Objective To investigate the efficiency of levodopa in dopa responsive dystonia (DRD) patients and drugs safety in pregnancy cases confirmed by genetic detection.Methods The clinical characteristics of two patients were analyzed.Direct sequences were performed in guanosine triphosphate (GTP) cyclohydrolase Ⅰ (GCH1) gene and tyrosine hydroxylase (TH) gene mutation screening.Results Case 1 was a young man exhibiting writer's cramp and dystonia of lower legs with marked diurnal fluctuation.Writer's cramp could not be relieved by treatment of low dose levodopa/benserazide.After increasing dose,the symptom of writer's cramp appeared occasionally.Case 2 was a young woman who experienced gait disorder.The symptom disappeared completely by levodopa treatment.She used levodopa and benzhexol during pregnancy.By 38 gestational weeks,she gave birth to a healthy baby.Sequence analysis of GCH1 gene in case 1 revealed a mutation (c.230C ＞ G p.S77C) that is a novel pathogenic mutation.The confirmed mutation c.628delC (p.His210Thrfs* 5) found in case 2 had been reported previously.No mutations in TH gene were detected in two patients.Condnsions Most of DRD patients have dramatic response to levodopa,but patients exhibited writer' s cramp may respond to levodopa incompletely.The previous reports indicate that no adverse events have been reported in DRD pregnant women with the monotherapy of levodopa.
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It has been suggested that transition metal ions such as iron can produce an oxidative injuries to nigrostriatal dopaminergic neurons, like Parkinson's disease (PD) and subsequent compensative increase of tetrahydrobiopterin (BH4) during the disease progression induces the aggravation of dopaminergic neurodegeneration in striatum. It had been established that the direct administration of BH4 into neuron would induce the neuronal toxicity in vitro. To elucidate a role of BH4 in pathogenesis in the PD in vivo, we assessed the changes of dopamine (DA) and BH4 at striatum in unilateral intranigral iron infused PD rat model. The ipsistriatal DA and BH4 levels were significantly increased at 0.5 to 1 d and were continually depleting during 2 to 7 d after intranigral iron infusion. The turnover rate of BH4 was higher than that of DA in early phase. However, the expression level of GTP-cyclohydrolase I mRNA in striatum was steadily increased after iron administration. These results suggest that the accumulation of intranigral iron leads to generation of oxidative stress which damage to dopaminergic neurons and causes increased release of BH4 in the dopaminergic neuron. The degenerating dopaminergic neurons decrease the synthesis and release of both BH4 and DA in vivo that are relevance to the progression of PD. Based on these data, we propose that the increase of BH4 can deteriorate the disease progression in early phase of PD, and the inhibition of BH4 increase could be a strategy for PD treatment.
Subject(s)
Disease Progression , Dopamine , Dopaminergic Neurons , Ions , Iron , Models, Animal , Neurons , Oxidative Stress , Parkinson Disease , RNA, MessengerABSTRACT
Objective To investigate the clinical characteristics,treatment effect,long-term follow up results,guanosine triphosphate (GTP) cyrclohydrolase Ⅰ (GCH Ⅰ)gene and tyrosine hydroxylase(TH) gene mutations in patients with dopa-responsive dystonia (DRD).Methods The clinical features of 3 families with 4 affected members were analyzed and all of 4 patients were screened for mutations of the GCH Ⅰ gene and TH gene with DNA sequences.Results Four patients were females,average age at onset was (15.3 ± 5.6) years (range:from 9 to 20 years).The initial symptoms were a gait disorder,stiffness or tremor of the lower limbs in all patients presented with diurnal fluctuation.As the increase of disease duration,bilateral hand tremor was found in three patients,systemic torsion was found in one patient and torticollis was found in one patient.All patients' symptoms were in complete remission after administration of low dose of levodopa.Four patients were followed up for 0.5 to 10.0 years,and all were still responsive to the levodopa treatment and effective dosage was decreased as the increase of the disease duration.No longterm side effects of levodopa had occurred after long-term treatment.One patient was found to have c.607G ＞A(p,Gly203Arg) heterogenetic mutation in GCH I gene.Molecular analysis revealed a compound heterozygous mutation in the TH gene (p.Y447Ter and p.V468M) in one patient.No point mutations in both genes were found in other patients.Conclusions DRD patients have dramatic and sustained response to levodopa and no long-term side effects of levodopa after long-term treatment.The detection of GCH Ⅰ and TH gene mutations is helpful in early diagnosis but the negative results could not exclude the diagnosis of DRD.
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Objective To study the effects of sodium arsenite on the mRNA expression of GTP cyclohydrolase (GTPCH) and 6-pyruvoyl-tetrahydropterin synthase (PTPS) in Chang liver cells. Methods Human Chang liver cells were cultured with sodium arsenite at doses of 0, 50, 200 and 400 ?mol/L for 12 hours. Cell viability was tested by MTT assay, and the expression of mRNA of GTPCH and PTPS was detected by RT-PCR. Results Cell viability in 50 ?mol/L group was almost the same as that in control, while the viability in the other two groups were significantly lower than that in control. All of the mRNA expression levels in the three groups were significantly lower than that in control with dose-dependent manner. Conclusion The down-regulated expression of GTPCH and PTPS, the main enzymes of the synthesis of BH4, induced by sodium arsenite exposure may be related with arsenic related skin depigmentation.
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Segawa disease, hereditary progressive dystonia with marked diurnal fluctuations or defined dopa-responsive dystonia has age-dependent clinical courses, which are characterized with marked progression in the first one and half decades, its subsiding in the third decade and almost stationary courses after the fourth decade. Also, it has characteristic diurnally fluctuating symptoms, aggravated towards the evening and alleviated after sleep. This autosomally dominantly inherited dystonia is caused by abnormalities of the gene of GTP cyclohydrolase I. The heterozygotic gene's abnormality induces partial decrement of tetrahydrobiopterin and affects synthesis of tyrosine hydroxylase(TH) rather selectively. The reduction of TH induces decrement of dopamine and disfacilitates the D1 receptor-striatal direct pathway. The pathognomonic finding in biochemical examination is the decrease of neopterin in the cerebrospinal fluid(CSF). Levodopa, by replacing dopamine contents at the terminal, alleviates motor symptoms completely and the effects sustain without any side effects. We experienced a girl diagnosed as Segawa disease with typical clinical courses and a decrease of neopterin in the CSF.
Subject(s)
Female , Humans , Dopamine , Dystonia , Genetic Diseases, Inborn , GTP Cyclohydrolase , Levodopa , Neopterin , TyrosineABSTRACT
Objective To detect the mutations in coding region of the guanosine triphosphate cyclohydrolase Ⅰ (GCH1) gene in Chinese patients with dopa-responsive dystonia (DRD).Methods Two families with five affected family members and six patients with sporadic DRD were examined, as well as their eighteen relatives and twenty normal members. Mutation screening was performed using single-strand conformation polymorphism analysis followed by direct sequencing of the presumably mutated exons; in patients whose results showed a normal pattern on single-strand conformation polymorphism analysis, the entire coding region of the GCH1 gene was sequenced. To confirm the mutation, a pair of primers was designed, which produced a restrictive site for SphI.Results DNA sequencing revealed a new heterozygous A224G missense mutation (Tyr75Cys) located within exon 1 in one family with autosomal-dominant inheritance. The mutation was confirmed with restriction enzyme analysis; it was not present in 20 control alleles. Restriction enzyme analysis also detects two systematic gene mutation carriers. In patients from the other family and patients with sporadic DRD, no alterations in the translated portion of the GCH1 gene were observed. Direct sequencing also showed that there existed gene polymorphisms in intron 1 and intron 3 which neared the exon2 and exon3 respectively in Chinese.Conclusions We describe a new missense mutation (Tyr75Cys) in the GCH1 gene. Mutation in the coding region of the gene might be accounted for a part of patients with DRD.
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Objective To observe the effect of gene therapy for Parkinson disease by triple transduction with dopamine-biosynthesizing enzyme genes. Methods We constructed high titer purified adeno-associated virus (AAV) vectors containing cDNAs encoding human tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC) and GTP cyclohydrolase I (GCH) respectively. AAV-TH, AAV-AADC and AAV-GCH were stereotaxically injected into the denervated striatum of Parkinsonian rat; the expression of TH, AADC or GCH was assayed by using immunohistochemical staining; the rotational behavior was assayed for 1 year.Results The immunohistochemical staining and behavioral testing showed that all of TH, AADC and GCH were expressed stably in the striatum, and the rats treated with AAV-TH, AAV-AADC and AAV-GCH showed more remarkable decrease in rotation rate persisted for at least 1 year, than those treated with AAV-TH and AAV-AADC(P