| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Logotheti, Marianthi, et al.
(författare)
-
Recent Advancements in Bipolar Disorder studies through Genomic, Epigenomic and Metagenomic Approaches
- 2019
-
Ingår i: Journal of Psychiatry and Psychology Research. - : SciTech Central Inc.. - 2640-6136. ; 2:1, s. 56-66
-
Forskningsöversikt (refereegranskat)abstract
- Bipolar disorder is a complex and highly heritable psychiatric disorder characterized by severe mood alterations. The precise geneticunderpinnings of the disease have not been identified so far, despite numerous genome-wide association findings. This review describes thecurrent state of genetic studies based on next generation sequencing technologies including whole exome and whole genome sequencing, aswell as RNA-sequencing and highlights the fact that the integration of these studies can reveal novel knowledge such as the functional roleof gene variants. However, due to the complexity of bipolar disorder, it is a compelling candidate for studies beyond DNA and RNAsequencing. Epigenetic alterations, defined as heritable but reversible modifications including DNA methylation, DNAhydroxymethylation, histone modifications and non-coding RNAs may be the link between genome and environment interactions.Additionally, a possible source of the reported immune activation in bipolar disorder is the micro biome of gastrointestinal tract, due torecent studies that indicate its pivotal role in brain function through the ‘gut-brain’ axis. The identification of methods able to modulate themicro biome emerges as a promising path for novel diagnostic and treatment options in bipolar disorder, thus the number of metagenomicstudies in bipolar disorder has substantially increased the last years. Overall, the paper aims to review the most recent literature ongenomic, epigenomic and metagenomic studies that have contributed to our understanding of the pathophysiology of bipolar disorder sofar. The paper also focuses on the exploitation of recent advancements in high-throughput technologies for the elucidation of bipolardisorder through different approaches that may provide complementary knowledge and concludes to the need for merging the gap betweenall the gathered knowledge from the analysis of high-throughput data.
|
|
| 5. |
- Olsson, Emma, 1977-, et al.
(författare)
-
Tyrosine transport in fibroblasts from healthy volunteers and patients with schizophrenia
- 2006
-
Ingår i: Neuroscience Letters. - : Elsevier. - 0304-3940 .- 1872-7972. ; 393, s. 211-215
-
Tidskriftsartikel (refereegranskat)abstract
- Aberrant tyrosine transport across the fibroblast membrane, as measured by lower Vmax and/or lower Km is a repeated finding in patients with schizophrenia. The aim of this study was to investigate the importance of two major transporters, the L- and A-systems and tyrosine transport in fibroblast cell lines from patients with schizophrenia and healthy volunteers. Fibroblast cell lines, n=6 from healthy volunteers and n=6 from patients with schizophrenia, were included in the study. Uptake of [14-C] L-tyrosine in fibroblasts was measured using the cluster tray method in absence and presence of inhibitors. The uptake of tyrosine by the L-system was evaluated with the inhibitor 2-aminobicyclo heptane-2-carboxylic acid (BCH) and the A-system with the inhibitor nonmetabolized methyl-aminoisobutyric acid (MeAIB). Using [14-C] MeAIB the functionality of system A isoform 2, ATA2, was tested. BCH inhibited the uptake of tyrosine with 90%, showing that tyrosine transport in fibroblasts is mainly transported by the L-system. Not more than 10% could be contributed by the A-system. Excess of MeAIB did not influence tyrosine kinetics. Moreover, MeAIB kinetics did not differ between the patients and the controls. In conclusion, aberrant tyrosine transport observed in patients with schizophrenia is probably linked to the one of the L-systems and does not seem to involve the ATA2 transporter.
|
|
| 6. |
- Pernow, Ylva, et al.
(författare)
-
Aberrant tryptophan transport in cultured fibroblast from patients with Male Idiopathic Osteoporosis : an in vitro study
- 2018
-
Ingår i: Bone Reports. - Amsterdam, Netherlands : Elsevier. - 2352-1872. ; 8, s. 25-28
-
Tidskriftsartikel (refereegranskat)abstract
- It has been demonstrated, that long-term chronic tryptophan deficiency, results in decreased serotonin synthesis, which may lead to low bone mass and low bone formation. Findings from studies in male patients with idiopathic osteoporosis suggested a decreased transport of tryptophan in erythrocytes of osteoporotic patients, indicating that serotonin system defects may be involved in the etiology of low bone mass. Tryptophan is the precursor of serotonin, and a disturbed transport of tryptophan is implicated in altered serotonin synthesis. However, no study has investigated the tryptophan transport kinetics in MIO patients. The aim of this study is to investigate the kinetic parameters of tryptophan transport in fibroblasts derived from MIO patients compared to age and sex matched controls.Fibroblast cells were cultured from skin biopsies obtained from 14 patients diagnosed with Male Idiopathic Osteoporosis and from 13 healthy age-sex matched controls, without a diagnosis of osteoporosis. Transport of the amino acid tryptophan across the cell membrane was measured by the cluster tray method. The kinetic parameters, maximal transport capacity (Vmax) and affinity constant (Km) were determined by using the Lineweaver-Burke plot equation.The results of this study have shown a significantly lower mean value for Vmax (p = 0.0138) and lower Km mean value (p = 0.0009) of tryptophan transport in fibroblasts of MIO patients compared to the control group. A lower Vmax implied a decreased tryptophan transport availability in MIO patients.In conclusion, reduced cellular tryptophan availability in MIO patients might result in reduced brain serotonin synthesis and its endogenous levels in peripheral tissues, and this may contribute to low bone mass/formation. The findings of the present study could contribute to the etiology of idiopathic osteoporosis and for the development of novel approaches for diagnosis, treatment and management strategies of MIO.
|
|
| 7. |
- Rode, Julia, 1992-, et al.
(författare)
-
Butyrate Rescues Oxidative Stress-Induced Transport Deficits of Tryptophan : Potential Implication in Affective or Gut-Brain Axis Disorders.
- 2021
-
Ingår i: Neuropsychobiology. - : S. Karger. - 0302-282X .- 1423-0224. ; 80, s. 253-263
-
Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Butyrate is a short-chain fatty acid metabolite produced by microbiota in the colon. With its antioxidant properties, butyrate has also been shown to alter the neurological functions in affective disorder models, suggesting it as a key mediator in gut-brain interactions.OBJECTIVE: Here, we evaluated the negative effect of oxidative stress on the transport of the serotonin precursor tryptophan as present in affective disorders. Butyrate was hypothesized to be able to rescue these deficits due to its antioxidative capacities and its effect on transmembrane transport of tryptophan. Human skin-derived fibroblasts were used as cellular models to address these objectives.METHODS: Human fibroblasts were treated with hydrogen peroxide to induce oxidative stress. Stressed as well as control cells were treated with different concentrations of butyrate. Tryptophan (3H) was used as a tracer to measure the transport of tryptophan across the cell membranes (n = 6). Furthermore, gene expression profiles of different amino acid transporters were analyzed (n = 2).RESULTS: As hypothesized,oxidative stress significantly decreased the uptake of tryptophan in fibroblast cells, while butyrate counteracted this effect. Oxidative stress did not alter the gene expression profile of amino acid transporters. However, treatment of stressed and control cells with different concentrations of butyrate differentially regulated the gene expression of large amino acid transporters 1 and 2, which are the major transporters of tryptophan.CONCLUSIONS: Gut microbiota-derived butyrate may have therapeutic potential in affective disorders characterized by either aberrant serotonergic activity or neuroinflammation due to its role in rescuing the oxidative stress-induced perturbations of tryptophan transport.
|
|
| 8. |
|
|
| 9. |
- Tabrisi, Reza, 1982-, et al.
(författare)
-
Clozapine but not lithium reverses aberrant tyrosine uptake in patients with bipolar disorder
- 2023
-
Ingår i: Psychopharmacology. - : Springer. - 0033-3158 .- 1432-2072. ; 240:8, s. 1667-1676
-
Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: Availability of the dopamine and noradrenaline precursor tyrosine is critical for normal functioning, and deficit in tyrosine transport across cell membrane and the blood-brain barrier has been reported in bipolar disorder and schizophrenia. Clozapine and lithium are two psychoactive agents used to treat psychosis, mood disorders and suicidal behavior, but their mechanism of action remains largely unknown.OBJECTIVE: To characterize immediate and delayed differences in tyrosine uptake between healthy controls (HC) and bipolar patients (BP) and see if these differences could be normalized by either clozapine, lithium or both. A second objective was to see if clozapine and lithium have additive, antagonistic or synergistic effects in this.METHOD: Fibroblasts from five HC and five BP were incubated for 5 min or 6 h with clozapine, lithium, or combination of both. Radioactive labelled tyrosine was used to quantify tyrosine membrane transport.RESULTS: There was significantly reduced tyrosine uptake at baseline in BP compared to HC, a deficit that grew with increasing incubation time. Clozapine selectively increased tyrosine uptake in BP and abolished the deficit seen under baseline conditions, while lithium had no such effect. Combination treatment with clozapine and lithium was less effective than when clozapine was used alone.CONCLUSIONS: There was significant deficit in tyrosine transport in BP compared to HC that was reversed by clozapine but not lithium. Clozapine was more effective when used alone than when added together with lithium. Potential clinical implications of this will be discussed.
|
|
| 10. |
|
|
