Lauric acid with or without levodopa ameliorates Parkinsonism in genetically modified model of Drosophila melanogaster via the oxidative-inflammatory-apoptotic pathway.

BACKGROUND: Parkinson's disease (PD), the most prevalent type of Parkinsonism, is a progressive neurological condition characterized by a range of motor and non-motor symptoms. The complicated etiology of PD is thought to involve a summation of aging, genetic predisposition, and environmental variables. However, the α-synuclein protein plays a significant role in the disease's pathophysiology. MATERIALS AND METHODS: The UAS-α-Syn and Ddc-Gal4 strains were crossed to produce offspring referred to as PD flies. The entire population of flies was divided into five groups, each having about 100 flies and five replicates. The control group (w1118) and the PD group not receiving treatment were exposed to lauric acid (LA)/levodopa (LD)-free diet, while the PD groups that received treatments were fed with either a 250 mg/kg LA diet, a 250 mg/kg LD diet, or a combination of the two for 21 days. Longevity, geotaxis, and olfactory assays were performed in addition to other biochemical tests. RESULTS: As a result of the overexpression of α-synuclein, the locomotive capacity, lifespan, and antioxidant status were all significantly (p < .05) reduced, and the apoptotic and neuroinflammatory activities were increased. Nevertheless, the majority of the treated flies improved significantly (p < .05). CONCLUSION: LA, whether combined with LD or not, elicited a significant response in α-synuclein/dopa decarboxylase genetically modified Drosophila melanogaster Parkinsonism models.

Combined effects of vitamin D3 and dioxopiperidinamide derivative on lipid homeostasis, inflammatory pathways, and redox imbalance in non-alcoholic fatty liver disease in vivo zebrafish model.

Liver damage and metabolic dysfunctions, the defining features of non-alcoholic fatty liver disease (NAFLD), are marked by inflammation, oxidative stress, and excessive hepatic fat accumulation. The current therapeutic approaches for NAFLD are limited, necessitating exploring novel treatment strategies. Dioxopiperidinamide derivatives, particularly DOPA-33, have shown effective anti-inflammatory and antioxidant properties, potentially offering therapeutic benefits against NAFLD. This study investigated the combined potential of vitamin D3 (Vit D3) and DOPA-33 in treating NAFLD. The network pharmacology analysis identified key NAFLD targets modulated by Vit D3 and DOPA-33, emphasizing their potential mechanisms of action. In NAFLD-induced zebrafish models, Vit D3 and DOPA-33 significantly reduced hepatic lipid accumulation, oxidative stress, and apoptosis, demonstrating superior efficacy over individual treatments. The treatment also lowered reactive oxygen species (ROS) levels, decreased liver damage, and enhanced antioxidant defense mechanisms. Moreover, behavioral analyses showed improved locomotion and reduced weight gain in treated zebrafish. Biochemical analyses revealed lower triglycerides (TG) and glucose levels with improved oxidative markers. Furthermore, histological analyses indicated reduced hepatic steatosis and inflammation, with decreased expression of lipogenesis-related genes and inflammatory mediators. Finally, high-performance liquid chromatography (HPLC) confirmed a significant reduction in hepatic cholesterol levels, indicating the effectiveness of the combination therapy in addressing key NAFLD-related dyslipidemias. These findings suggest that Vit D3 + DOPA-33 targets pathways involved in lipid metabolism, inflammation, and oxidative stress by offering a promising therapeutic approach for NAFLD.

Long-standing preservation of levodopa response in progressive supranuclear palsy.

The clinical and neuropathological characteristics of progressive supranuclear palsy (PSP) with preservation of levodopa (L-dopa) response are described in this report. We present the case of a 73-year-old Japanese man with a 13-year history of dopa-responsive Parkinsonism and abnormalities observed in metaiodobenzylguanidine (MIBG) myocardial scintigraphy, suggesting Parkinson's disease. However, autopsy results revealed PSP pathology, including tuft-shaped astrocytes and globose-type neurofibrillary tangles, without Lewy body pathology. The degeneration was moderately to severely distributed in the globus pallidus, subthalamic nucleus, and substantia nigra, whereas striatal degeneration was mild. These findings suggest an intact response to L-dopa therapy throughout the patient's lifetime. Pathological examination of cardiac sympathetic nerves revealed intact nerves, suggesting functional involvement in the MIBG abnormality. This study provides further evidence of the clinical and pathological heterogeneity of PSP. Homozygosity for both the rs564309-C allele at TRIM11 and the rs2242367-G allele at SLC2A13 might have played a protective role. This case indicates a protracted course-PSP, which may hold promise for future treatments.

Dihydroxyphenylalanine-conjugated high molecular weight polyethylenimine for targeted delivery of Plasmid.

High molecular weight polyethylenimine (HMW PEI; branched 25 kDa PEI) has been widely investigated for gene delivery due to its high transfection efficiency. However, the toxicity and lack of targeting to specific cells have limited its clinical application. In the present investigation, L-3, 4-dihydroxyphenylalanine (L-DOPA) was conjugated on HMW PEI in order to target L-type amino acid transporter 1 (LAT-1) and modulate positive charge density on the surface of polymer/plasmid complexes (polyplexes). The results of biophysical characterization revealed that the PEI conjugates are able to form nanoparticles ≤ 180 nm with the zeta potential ranging from + 9.5-12.4 mV. These polyplexes could condense plasmid DNA and protect it against nuclease digestion at the carrier to plasmid ratios higher than 4. L-DOPA conjugated PEI derivatives were complexed with a plasmid encoding human interleukin-12 (hIL-12). Targeted polyplexes showed up to 2.5 fold higher transfection efficiency in 4T1 murine mammary cancer cell line, which expresses LAT-1, than 25 kDa PEI polyplexes prepared in the same manner. The cytotoxicity of these polyplexes was also substantially lower than the unmodified parent HMW PEI. These results support the use of L-3, 4-dihydroxyphenylalanine derivatives of PEI in any attempt to develop a LAT-1 targeted gene carrier.

Observing extradiol dioxygenases in action through a crystalline lens.

Extradiol dioxygenases are a class of non-heme iron-dependent enzymes found in eukaryotes and prokaryotes that play a vital role in the aerobic catabolism of aromatic compounds. They are generally divided into three evolutionarily independent superfamilies with different protein folds. Our recent studies have shed light on the catalytic mechanisms and structure-function relationships of two specific extradiol dioxygenases: 3-hydroxyanthranilate-3,4-dioxygenase, a Type III enzyme essential in mammals for producing a precursor for nicotinamide adenine dinucleotide, and L-3,4-dihydroxyphenylalanine dioxygenase, an uncommon form of Type I enzymes involved in natural product biosynthesis. This work details the expression and isolation methods for these extradiol dioxygenases and introduces approaches to achieve homogeneity and high occupancy of the enzyme metal centers. Techniques such as ultraviolet-visible and electron paramagnetic resonance spectroscopies, as well as oxygen electrode measurements, are discussed for probing the interaction of the non-heme iron center with ligands and characterizing enzymatic activities. Moreover, protein crystallization has been demonstrated as a powerful tool to study these enzymes. We highlight in crystallo reactions and single-crystal spectroscopic methods to further elucidate enzymatic functions and protein dynamics.

Noninvasive Therapies: A Forthcoming Approach to Parkinson's Treatment.

In this review, we have discussed the invasive and non-invasive treatment options for Parkinson's Disease (PD) following their safety, specificity, and reliability. Initially, this study has highlighted the invasive treatment options and the side effects they possess. A deep understanding of L-Dopa treatment, as oral or infusion, and the use of dopamine agonists has indicated that there is a need to acquire an alternative treatment for PD. The combined therapy with L-Dopa has been proven to affect PD, but with some limitations, such as mild to chronic side effects, with particular requirements of age and health of the patient and a large amount of expenditure. In the discussion of noninvasive methods to treat PD, we have found that this approach is comparatively slow and requires repetitive sessions, but is safe, effective, and reliable at any stage of PD. Electroconvulsive therapy has revealed its effectiveness in various neurological diseases, including PD. Transcranial current stimulation (direct or alternative) has already been shown to have an alleviative response to PD symptoms. Transcranial magnetic stimulations and other strategies of using the magnetic field for potential treatment options for PD need to be explored further imminently.

Neuroprotective effects of L-Dopa-modified zinc oxide nanoparticles on the rat model of 6-OHDA-induced Parkinson's disease.

Parkinson's disease (PD) is a chronic neurodegenerative case. As the disease progresses, the response time to doses of levodopa (L-Dopa) becomes shorter and the effects of the drug are severely limited by some undesirable side effects such as the 'on-off' phenomenon. In several diseases, including Parkinson's, nanoparticles can deliver antioxidant compounds that reduce oxidative stress. This study evaluates and compares the neuroprotective effects of L-Dopa-modified zinc nanoparticles (ZnNPs) in the 6-hydroxydopamine (6-OHDA)-induced PD rat model. For this purpose, the synthesis of NPs was carried out. Scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectrophotometer were used for characterization. The rats were randomized into 9 experimental groups: control, lesion group (6-OHDA), 6-OHDA + 5 mg/kg L-Dopa, 6-OHDA + 10 mg/kg L-Dopa, 6-OHDA + 20 mg/kg L-Dopa, 6-OHDA + 20 mg/kg ZnNPs, 6-OHDA + 40 mg/kg ZnNPs, 6-OHDA + 30 mg/kg ZnNPs + L-Dopa, and 6-OHDA + 60 mg/kg ZnNPs + L-Dopa. Behavioral tests were performed on all groups 14 days after treatment. Phosphatase and tensin homolog, Excitatory amino acid transporter 1/2, and Glutamine synthetase gene analyses were performed on brain samples taken immediately after the tests. In addition, histological and immunohistochemical methods were used to determine the general structure and properties of the tissues. We obtained important findings that L-Dopa-modified ZnNPs increased the activity of glutamate transporters. Our experiment showed that glutamate increases neuronal cell vitality and improves behavioral performance. Therefore, L-Dopa-modified ZnNPs can be used to prevent neurotoxicity. According to what we found, results show that L-Dopa-modified ZnNPs will lend to the effective avoidance and therapy of PD.

Proline-rich transmembrane protein 2 regulates the magnitude and frequency of dopamine release by repetitive neuronal stimuli in the striatum of L-dopa-treated mice.

Mutations in proline-rich transmembrane protein 2 (PRRT2) cause paroxysmal kinesigenic dyskinesia (PKD). Recently, we reported that a Prrt2 mutation exacerbated L-dopa-induced motor deficits in mice, suggesting that the basal ganglia might contribute to PKD pathology. Here, we demonstrated that the Prrt2 mutation enhanced depolarization stimuli-induced extracellular dopamine levels in the mouse striatum, which were attenuated by repeated stimulation. L-dopa administration maintained high dopamine levels in Prrt2-KI mice even during repetitive stimuli but did not affect dopamine levels in wild-type mice. Thus, the enhanced and prolonged responsiveness of dopamine release in nigrostriatal dopaminergic neurons to sequential excitation may be partially implicated in Prrt2-related dyskinesia.

Emission of 50-kHz ultrasonic vocalizations stimulated by antiparkinsonian dopaminomimetic drugs in hemiparkinsonian rats is associated with neuronal activation in subcortical regions that regulate the affective state.

Dopamine replacement therapy (DRT) of Parkinson's disease (PD) may trigger non-motor complications, some of which affect hedonic homeostatic regulation. Management of iatrogenic alterations in the affective state in PD is unsatisfactory, partly because of the limitations in the experimental models that are used in the preclinical investigation of the neurobiology and therapy of these alterations. In this connection, we recently employed a new experimental approach consisting in measuring the emission of 50-kHz ultrasonic vocalizations (USVs), a marker of positive affect, in hemiparkinsonian rats treated with drugs used in the DRT of PD. To further strengthen our approach, we here evaluated how the acute and repeated (× 5, on alternate days) administration of apomorphine (2 mg/kg, i.p.) or L-3,4-dihydroxyphenilalanine (L-DOPA, 12 mg/kg, i.p.) modified the immunoreactivity for Zif-268, a marker of neuronal activation, in the nucleus accumbens (NAc), caudate-putamen (CPu) and medial prefrontal cortex (mPFC), which are brain regions that regulate emotional states and drugs' affective properties. Acute and repeated treatment with either apomorphine or L-DOPA stimulated the emission of 50-kHz USVs in hemiparkinsonian rats, and this effect was paired with increased Zif-268 immunoreactivity in the NAc and CPu, but not mPFC. These findings indicate that subcortical and cortical regions may differently regulate the emission of 50-kHz USVs in hemiparkinsonian rats treated with dopaminergic drugs used in the DRT of PD. Moreover, they provide further evidence that measuring 50-kHz USV emissions in hemiparkinsonian rats may be a relevant approach to investigate at the preclinical level the affective properties of antiparkinsonian drugs.

18F-DOPA PET/MRI With Carbidopa for the Diagnosis of Hyperinsulinemic Hypoglycemia in an Adolescent Patient.

Hyperinsulinism due to focal or diffuse pancreatic lesions causing recurrent episodes of hypoglycemia is rare in mid-childhood. There is no consensus on the gold-standard imaging method to diagnose focal insulin-producing lesions beyond infancy. A 14-year-old boy with a complex medical history and refractory epilepsy, presented with blood glucose (BG) of 52 mg/dL (2.9 mmol/L) (normal reference range: 70-100 mg/dL [3.9-5.6 mmol/L]) and increased seizure frequency. He failed a fast within 4 hours, with BG of 48 mg/dL (2.7 mmol/L) and insulin level of 4.6 µIU/mL (24.6 pmol/L) (diagnostic at the time of hypoglycemia >1.25 µU/mL [8.7 pmol/L]). Conventional imaging studies showed no pancreatic lesion. Fluorine-18-L-dihydroxyphenylalanine positron emission tomography/magnetic resonance imaging (18F-DOPA-PET/MRI) scan premedicated with carbidopa demonstrated intense focal 18F-DOPA uptake in the distal pancreatic tail. He underwent distal pancreatectomy. Histopathology showed focal pancreatic islet cell hyperplasia, with more than 90% of the neuroendocrine islet cells being positive for chromogranin and synaptophysin, with no loss of p57 staining. Genetic studies were negative for mutations in ABCC8, KCNJ11, GCK, or GLUD1 genes, multiple endocrine neoplasia (MEN) type 1, and Beckwith-Wiedemann syndrome. BG normalized after surgery. Seizure frequency improved. This case highlights the utility of 18F-DOPA PET/MRI imaging in diagnosing focal hyperinsulinism beyond infancy.

Diagnostic Modalities, Management Considerations, and Outcomes of Insulinoma: A Case Series from a Tertiary Care Centre.

Introduction: Insulinomas are rare, usually sporadic, and typically benign pancreatic neuroendocrine tumours. Pre-operative localization is challenging and evidence on comparative analysis of anatomic and scintigraphic modalities for pre-operative tumour localization is limited, even in contemporary series. Methods: The current study was designed to study the clinical features and management challenges of insulinomas managed at a tertiary care centre. Clinical features, diagnosis, imaging techniques, surgical procedures, and outcomes details were collated. Pre-operative imaging techniques (CT/MRI, nuclear scintigraphy) were compared with intraoperative and histopathological findings to assess their accuracy of localization. Results: Thirty-seven patients (15 females [42%]; median age 36 years [IQR 28-49]) were included in the study. In four patients (10.8%), the tumour occurred in the setting of multiple endocrine neoplasia type 1 (MEN 1) while the remaining were sporadic. The sensitivity of pre-operative localization was 61.5% (multiphasic CT), 66.6% (multiphasic MRI), 100% (68Ga Exendin-4 PET-CT), and 91.6% (EUS). Three patients with normal multiphasic CT had localization on 68Ga Exendin-4 PET-CT. The positive predictive value (PPV) of both Exendin-PET-CT and EUS was similar at 91.6% and 91.6%, respectively. All patients (except one with nesidioblastosis), who underwent enucleation or partial pancreatic resection, were cured. Conclusion: 68Ga Exendin-4 PET-CT based is a non-invasive imaging modality that has high sensitivity and PPV and can be used as a first-line imaging modality. The overall prognosis of these tumours is good with high cure rates attained following surgical resection.

Diabetic striatopathy: Hyperglycemic chorea/ballism successfully treated with L-dopa.

Diabetic striatopathy, a rare hyperglycemia complication, is characterized by chorea/ballism and striatal anomalies on neuroimaging, usually managed with glycemic control and haloperidol. However, practical strategies for haloperidol-resistant cases are scarce. We describe a 76-year-old Japanese woman with diabetic striatopathy who initially presented with polydipsia, polyuria, and lower-extremity weakness. Despite pronounced hyperglycemia (725 mg/dL), her blood glucose levels were reduced through saline infusion and intravenous insulin. Subsequently, she developed whole-body ballism concomitant with striatal hyperintensity on T1-weighted magnetic resonance imaging, which initially responded to haloperidol. Upon discontinuation of haloperidol, her symptoms relapsed and did not improve with the reintroduction of haloperidol. Dopamine transporter single photon emission computed tomography revealed diminished bilateral striatal uptake, suggesting presynaptic dopaminergic dysfunction. This finding prompted the initiation of L-dopa, which significantly improved her symptoms. This case underlines the need to consider presynaptic dopaminergic dysfunction in diabetic striatopathy patients unresponsive to standard treatments, highlighting the effectiveness of L-dopa in such scenarios.

(S)-3-(3,4-Dihydroxybenzyl) piperazine-2,5-dione (cyclo-Gly-L-DOPA or CG-Nio-CGLD) peptide loaded in Chitosan Glutamate-Coated Niosomes as anti-Colorectal cancer activity.

BACKGROUND: Colorectal cancer (CRC), now the second most prevalent malignant tumor worldwide, is more prevalent in young adults. In recent decades, there has been progress in creating anti-colorectal cancer medications, including cytotoxic compounds. OBJECTIVES: Novel anticancer drugs are needed to surmount existing obstacles. A recent study investigated the effectiveness of novel formulations in preventing colorectal cancer. METHODS: During this study, we assessed a new kind of niosome called cyclo-Gly-L-DOPA (CG-Nio-CGLD) made from chitosan glutamate. We evaluated the anti-colorectal cancer properties of CG-Nio-CGLD utilizing CCK-8, invasion assay, MTT assay, flow cytometry, and cell cycle analysis. The transcription of genes associated with apoptosis was analyzed using quantitative real-time PCR. At the same time, the cytotoxicity of nanomaterials on both cancer and normal cell lines was assessed using MTT assays. Novel anticancer drugs are needed to surmount existing obstacles. A recent study investigated the effectiveness of newly developed formulations in preventing colorectal cancer. RESULTS: The Nio-CGLD and CG-Nio-CGLD were spherical mean diameters of 169.12 ± 1.87 and 179.26 ± 2.17 nm, respectively. Entrapment efficiency (EE%) measurements of the Nio-CGLD and CG-Nio-CGLD were 63.12 ± 0.51 and 76.43 ± 0.34%, respectively. In the CG-Nio-CGLD group, the percentages of early, late, necrotic, and viable CL40 cells were 341.93%, 23.27%, 9.32%, and 25.48%. The transcription of the genes PP53, cas3, and cas8 was noticeably higher in the treatment group compared to the control group (P > 0.001). Additionally, the treatment group had lower BCL2 and survivin gene expression levels than the control group (P < 0.01). Additionally, CG-Nio-CGLD formulations demonstrated a biocompatible nanoscale delivery mechanism and displayed little cytotoxicity toward the CCD 841 CoN reference cell line. CONCLUSION: These findings indicate that chitosan-based noisome encapsulation may enhance the effectiveness of CG-Nio-CGLD formulations in fighting cancer.

Pharmacodynamic, pharmacokinetic and rat brain receptor occupancy profile of NLX-112, a highly selective 5-HT1A receptor biased agonist.

NLX-112 (i.e., F13640, befiradol) exhibits nanomolar affinity, exceptional selectivity and full agonist efficacy at serotonin 5-HT1A receptors. NLX-112 shows efficacy in rat, marmoset and macaque models of L-DOPA induced dyskinesia (LID) in Parkinson's disease and has shown clinical efficacy in a Phase 2a proof-of-concept study for this indication. Here we investigated, in rats, its pharmacodynamic, pharmacokinetic (PK) and brain 5-HT1A receptor occupancy profiles, and its PK properties in the absence and presence of L-DOPA. Total and free NLX-112 exposure in plasma, CSF and striatal ECF was dose-proportional over the range tested (0.04, 0.16 and 0.63 mg/kg i.p.). NLX-112 exposure increased rapidly (Tmax 0.25-0.5h) and exhibited approximately threefold longer half-life in brain than in plasma (1.1 and 3.6h, respectively). At a pharmacologically relevant dose of 0.16 mg/kg i.p., previously shown to elicit anti-LID activity in parkinsonian rats, brain concentration of NLX-112 was 51-63 ng/g from 0.15 to 1h. In microPET imaging experiments, NLX-112 showed dose-dependent reduction of 18F-F13640 (i.e., 18F-NLX-112) brain 5-HT1A receptor labeling in cingulate cortex and striatum, regions associated with motor control and mood, with almost complete inhibition of labeling at the dose of 0.63 mg/kg i.p.. Co-administration of L-DOPA (6 mg/kg s.c., a dose used to elicit LID in parkinsonian rats) together with NLX-112 (0.16 mg/kg i.p.) did not modify PK parameters in rat plasma and brain of either NLX-112 or L-DOPA. Here, we demonstrate that NLX-112's profile is compatible with 'druggable' parameters for CNS indications, and the results provide measures of brain concentrations and 5-HT1A receptor binding parameters relevant to the anti-dyskinetic activity of the compound.

L-DOPA Test in the Diagnosis of Childhood Short Stature: Evaluation of Growth Hormone Peaks Over Time.

INTRODUCTION: In childhood, growth hormone (GH) deficiency (GHD) diagnosis is based on auxological assessment and biochemical provocative tests, whose reliability remains disputed. Recently, several papers have been published on standardising the duration of some tests. The aim of our study was to analyse the possible length reduction of the L-DOPA provocative test. METHODS: We retrospectively investigated the response of GH to L-DOPA in 256 children, analysing 267 tests (some patients were retested over time for the persistence of severe auxopathy). We studied the same data considering GH peak threshold both at 8 ng/mL (Italian GHD cut-off) and at 10 ng/mL (international cut-off). Based on stimulation tests, patients were divided into two groups: GHD and no-GHD short children. We described the results in the whole population and then clustering for gender and pubertal stage. We termed as index the test stopped at 90 min. RESULTS: The GH peak after L-DOPA mostly occurred at 60 min. The sensitivity of the index test was the highest, while the specificity was slightly higher using the 8 ng/mL threshold (specificity = 0.68; 95% CI 0.60-0.76) then using the 10 ng/mL threshold (specificity = 0.56; 95% CI 0.47-0.65) at 90 min. The two ROC curves showed moderate performance of the test at 90 min. While the negative predictive value was 100% in both tests, the positive predictive value was slightly better with 10 ng/mL cut-off. Considering the two groups established by GHD definition and placing a GH threshold at 10 ng/mL, stopping L-DOPA test time at 90 min would have changed the test result and subsequentially patient's classification in 3/267 of the analysed tests (1.1%), while with the Italian GH threshold value at 8 ng/mL in 7/267 of the tests (2.6%). CONCLUSIONS: Our research shows that omitting 120-min time reduces L-DOPA test specificity, especially with GHD cut-off at 10 ng/mL.

Vicia faba L. Pod Valves: A By-Product with High Potential as an Adjuvant in the Treatment of Parkinson's Disease.

Vicia faba L. is a leguminous plant with seeds rich in nutritional compounds, such as polyphenols and L-dopa, a dopamine precursor and first-line treatment for Parkinson's symptoms. Recently, its by-products have been revalued as a sustainable source of bioactive compounds. In this study, aqueous extracts of Lucan broad bean pod valves (BPs) were characterized to evaluate their potential use as adjuvants in severe Parkinson's disease. L-dopa content, quantified by LC-UV, was much higher in BPs than in seeds (28.65 mg/g dw compared to 0.76 mg/g dw). In addition, vicine and convicine, the metabolites responsible for favism, were not detected in pods. LC-ESI/LTQ-Orbitrap/MS2 allowed the identification of the major polyphenolic compounds, including quercetin and catechin equivalents, that could ensure neuroprotection in Parkinson's disease. ESI(±)-FT-ICR MS was used to build 2D van Krevelen diagrams; polyphenolic compounds and carbohydrates were the most representative classes. The neuroprotective activity of the extracts after MPP+-induced neurotoxicity in SH-SY5Y cells was also investigated. BP extracts were more effective than synthetic L-dopa, even at concentrations up to 100 µg/mL, due to the occurrence of antioxidants able to prevent oxidative stress. The stability and antioxidant component of the extracts were then emphasized by using naturally acidic solutions of Punica granatum L., Ribes rubrum L., and gooseberry (Phyllanthus emblica L.) as extraction solvents.

Opposite regulation by L-DOPA receptor GPR143 of the long and short forms of the dopamine D2 receptors.

Dopamine (DA) D2 receptors (D2Rs) have 2 isoforms, a long form (D2L) and a short form (D2S). D2L is predominantly postsynaptic in the striatal medium spiny neurons and cholinergic interneurons. D2S is principally presynaptic autoreceptors in the nigrostriatal DA neurons. Recently, we demonstrated that L-3,4-dihydroxyphenylalanine (L-DOPA) augments D2L function through the coupling between D2L and GPR143, a receptor of L-DOPA that was originally identified as the gene product of ocular albinism 1. Here we show that GPR143 modifies the functions of D2L and D2S in an opposite manner. Haloperidol-induced catalepsy was attenuated in DA neuron-specific Gpr143 gene-deficient (Dat-cre;Gpr143flox/y) mice, compared with wild-type (Wt) mice. Haloperidol increased in vivo DA release from the dorsolateral striatum, and this increase was augmented in Gpr143-/y mice compared with Wt mice. A D2R agonist quinpirole-induced increase in the phosphorylation of GSK3ß(pGSK3ß(S9)) was enhanced in Chinese hamster ovary (CHO) cells coexpressing D2L and GPR143 compared with cells expressing D2L alone, while it was suppressed in cells coexpressing D2S and GPR143 compared with D2S alone, suggesting that GPR143 differentially modifies D2R functions depending on its isoforms of D2L and D2S.

Pharmacological Enhancement of Dopamine Neurotransmission Does Not Affect Illusory Pattern Perception.

Psychotic symptoms and delusional beliefs have been linked to dopamine transmission in both healthy and clinical samples and are assumed to result at least in part from perceiving illusory patterns in noise. However, the existing literature on the role of dopamine in detecting patterns in noise is inconclusive. To address this issue, we assessed the effect of manipulating dopaminergic neurotransmission on illusory pattern perception in healthy individuals (n = 48, n = 19 female) in a double-blind placebo-controlled within-subjects design (see preregistration at https://osf.io/a4k9j/). We predicted individuals on versus off ʟ-DOPA to be more likely to perceive illusory patterns, specifically objects in images containing only noise. Using a signal detection model, however, we found no credible evidence that ʟ-DOPA compared with placebo increased false alarm rates. Further, ʟ-DOPA did not reliably modulate measures of accuracy, discrimination sensitivity, and response bias. In all cases, Bayesian statistics revealed strong evidence in favor of the null hypothesis. The task design followed previous work on illusory pattern perception and comprised a limited number of items per condition. The results therefore need to be interpreted with caution, as power was limited. Future studies should address illusory pattern perception using more items and take into account potential dose-dependent effects and differential effects in healthy versus clinical samples.

Autosomal Recessive Guanosine Triphosphate Cyclohydrolase I Deficiency: Redefining the Phenotypic Spectrum and Outcomes.

BACKGROUND: The GCH1 gene encodes the enzyme guanosine triphosphate cyclohydrolase I (GTPCH), which catalyzes the rate-limiting step in the biosynthesis of tetrahydrobiopterin (BH4), a critical cofactor in the production of monoamine neurotransmitters. Autosomal dominant GTPCH (adGTPCH) deficiency is the most common cause of dopa-responsive dystonia (DRD), whereas the recessive form (arGTPCH) is an ultrarare and poorly characterized disorder with earlier and more complex presentation that may disrupt neurodevelopmental processes. Here, we delineated the phenotypic spectrum of ARGTPCHD and investigated the predictive value of biochemical and genetic correlates for disease outcome. OBJECTIVES: The aim was to study 4 new cases of arGTPCH deficiency and systematically review patients reported in the literature. METHODS: Clinical, biochemical, and genetic data and treatment response of 45 patients are presented. RESULTS: Three phenotypes were outlined: (1) early-infantile encephalopathic phenotype with profound disability (24 of 45 patients), (2) dystonia-parkinsonism phenotype with infantile/early-childhood onset of developmental stagnation/regression preceding the emergence of movement disorder (7 of 45), and (3) late-onset DRD phenotype (14 of 45). All 3 phenotypes were responsive to pharmacological treatment, which for the first 2 must be initiated early to prevent disabling neurodevelopmental outcomes. A gradient of BH4 defect and genetic variant severity characterizes the 3 clinical subgroups. Hyperphenylalaninemia was not observed in the second and third groups and was associated with a higher likelihood of intellectual disability. CONCLUSIONS: The clinical spectrum of arGTPCH deficiency is a continuum from early-onset encephalopathies to classical DRD. Genotype and biochemical alterations may allow early diagnosis and predict clinical severity. Early treatment remains critical, especially for the most severe patients.

Computer-aided design and implementation of efficient biosynthetic pathways to produce high added-value products derived from tyrosine in Escherichia coli.

Developing efficient bioprocesses requires selecting the best biosynthetic pathways, which can be challenging and time-consuming due to the vast amount of data available in databases and literature. The extension of the shikimate pathway for the biosynthesis of commercially attractive molecules often involves promiscuous enzymes or lacks well-established routes. To address these challenges, we developed a computational workflow integrating enumeration/retrosynthesis algorithms, a toolbox for pathway analysis, enzyme selection tools, and a gene discovery pipeline, supported by manual curation and literature review. Our focus has been on implementing biosynthetic pathways for tyrosine-derived compounds, specifically L-3,4-dihydroxyphenylalanine (L-DOPA) and dopamine, with significant applications in health and nutrition. We selected one pathway to produce L-DOPA and two different pathways for dopamine-one already described in the literature and a novel pathway. Our goal was either to identify the most suitable gene candidates for expression in Escherichia coli for the known pathways or to discover innovative pathways. Although not all implemented pathways resulted in the accumulation of target compounds, in our shake-flask experiments we achieved a maximum L-DOPA titer of 0.71 g/L and dopamine titers of 0.29 and 0.21 g/L for known and novel pathways, respectively. In the case of L-DOPA, we utilized, for the first time, a mutant version of tyrosinase from Ralstonia solanacearum. Production of dopamine via the known biosynthesis route was accomplished by coupling the L-DOPA pathway with the expression of DOPA decarboxylase from Pseudomonas putida, resulting in a unique biosynthetic pathway never reported in literature before. In the context of the novel pathway, dopamine was produced using tyramine as the intermediate compound. To achieve this, tyrosine was initially converted into tyramine by expressing TDC from Levilactobacillus brevis, which, in turn, was converted into dopamine through the action of the enzyme encoded by ppoMP from Mucuna pruriens. This marks the first time that an alternative biosynthetic pathway for dopamine has been validated in microbes. These findings underscore the effectiveness of our computational workflow in facilitating pathway enumeration and selection, offering the potential to uncover novel biosynthetic routes, thus paving the way for other target compounds of biotechnological interest.