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Biochemical Pharmacology May 2024The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have... (Review)
Review
The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have been implicated in various psychiatric disorders, including schizophrenia (SCZ). In particular, abnormalities in GABAergic signaling, specifically in parvalbumin (PV)-containing interneurons, have been consistently observed in SCZ pathophysiology. PV interneuron function is vital for maintaining an ideal E/I balance, and alterations in PV interneuron-mediated inhibition contribute to circuit deficits observed in SCZ, including hippocampus hyperactivity and midbrain dopamine system overdrive. While current antipsychotic medications primarily target D2 dopamine receptors and are effective primarily in treating positive symptoms, novel therapeutic strategies aiming to restore the E/I balance could potentially mitigate not only positive symptoms but also negative symptoms and cognitive deficits. This could involve, for instance, increasing the inhibitory drive onto excitatory neurons or decreasing the putative enhanced pyramidal neuron activity due to functional loss of PV interneurons. Compounds targeting the glycine site at glutamate NMDA receptors and muscarinic acetylcholine receptors on PV interneurons that can increase PV interneuron drive, as well as drugs that increase the postsynaptic action of GABA, such as positive allosteric modulators of α5-GABA-A receptors, and decrease glutamatergic output, such as mGluR2/3 agonists, represent promising approaches. Preventive strategies aiming at E/I balance also represent a path to reduce the risk of transitioning to SCZ in high-risk individuals. Therefore, compounds with novel mechanisms targeting E/I balance provide optimism for more effective and tailored interventions in the management of SCZ.
PubMed: 38782077
DOI: 10.1016/j.bcp.2024.116298 -
European Journal of Endocrinology Jun 2024Unravel the potential mechanism(s) of the on- and off-target actions of dopamine agonist therapy in both human prolactinoma tumors and neighboring stromal and immune...
OBJECTIVE
Unravel the potential mechanism(s) of the on- and off-target actions of dopamine agonist therapy in both human prolactinoma tumors and neighboring stromal and immune cells.
DESIGN AND METHODS
Five surgically resected prolactinomas (PRLomas) from 3 cabergoline (CBG)-treated patients and 2 treatment-naive patients were analyzed by using single-cell RNA sequencing (scRNA-seq) to compare the cellular composition and transcriptional landscape.
RESULTS
Six major cell populations, namely tumor (88.2%), immune (5.6%), stromal (4.9%), progenitor cells (0.6%), proliferating cells (0.4%), and erythrocytes (0.2%), were observed. Tumor cells from CBG-treated patients expressed lower levels of genes that regulated hormone secretion, such as SCG2, VGF, TIMP1, NNAT, and CALD1, consistent with the inhibitory effects of CBG on hormone processing and secretion. Interestingly, we also observed an increased number of CD8+ T cells in the CBG-treated tissues. These cytotoxic CD8+ T cells expressed killing granule components such as perforin and the granzymes GZMB, GNLY, and KLRD1 as well as the inflammatory cytokine CCL5. Immune cell activation of these CD8+ T cells was further analyzed in a compartment-specific manner, and increased CD25 (IL2R) expression was noted in the CD8+ T cells from the CBG-treated samples. Additionally, and confirming prior reports, we noted a higher stromal cell population in the CBG-treated samples.
CONCLUSIONS
Our scRNA-seq studies revealed key differences in the transcriptomic features of CBG-treated and CBG-untreated PRLomas in both tumor and microenvironment cellular constituents, and for the first time, describe the previously unknown activation of CD8+ T cells following CBG treatment, which may play a role in the tumoricidal actions of CBG.
Topics: Humans; Cabergoline; Prolactinoma; Male; Female; Pituitary Neoplasms; Adult; Middle Aged; Fibrosis; Prolactin; Dopamine Agonists; CD8-Positive T-Lymphocytes; Stromal Cells; Young Adult; Tumor Microenvironment
PubMed: 38781434
DOI: 10.1093/ejendo/lvae055 -
Current Opinion in Neurology Aug 2024to review recent progress in the development and use of continuous levodopa therapies in Parkinson disease (PD). (Review)
Review
PURPOSE OF REVIEW
to review recent progress in the development and use of continuous levodopa therapies in Parkinson disease (PD).
RECENT FINDINGS
Levodopa/Carbidopa intestinal gel (LCIG) is a continuous levodopa therapy which is widely used in the United States, Europe and other countries and is effective at reducing 'off' time. Recent work has shown that LCIG can be useful in managing dyskinesias and can improve nonmotor symptoms and quality of life. Several studies have shown good long-term effectiveness of LCIG. Recent data support the cost-effectiveness of this treatment strategy. Subcutaneous (SC) delivery of levodopa is a newer strategy that avoids the need for a surgically placed gastric tube. Two different products enabling SC delivery of levodopa are in development: ND0612 and foslevodopa/foscarbidopa. Both have recently been shown to reduce 'off' time in randomized, double-blind trials. Adverse effects of SC levodopa are primarily related to skin reactions at the infusion site.
SUMMARY
Continuous levodopa therapies can be used to treat Parkinson disease motor fluctuations that cannot be managed with standard oral therapies. They may also improve nonmotor symptoms, and improve overall quality of life in patients with advanced PD.
Topics: Humans; Levodopa; Parkinson Disease; Antiparkinson Agents; Carbidopa; Drug Combinations; Infusions, Subcutaneous
PubMed: 38780079
DOI: 10.1097/WCO.0000000000001277 -
Behavioural Brain Research Jul 2024Both dopamine (DA) and serotonin (5-HT) play key roles in numerous functions including motor control, stress response and learning. So far, there is scarce or...
Both dopamine (DA) and serotonin (5-HT) play key roles in numerous functions including motor control, stress response and learning. So far, there is scarce or conflicting evidence about the effects of 5-HT1A and 5-HT2A receptor (R) agonists and antagonists on recognition memory in the rat. This also holds for their effect on cerebral DA as well as 5-HT release. In the present study, we assessed the effects of the 5-HTR agonist 8-OH-DPAT and antagonist WAY100,635 and the 5-HTR agonist DOI and antagonist altanserin (ALT) on rat behaviors. Moreover, we investigated their impact on monoamine efflux by measuring monoamine transporter binding in various regions of the rat brain. After injection of either 8-OH-DPAT (3 mg/kg), WAY100,635 (0.4 mg/kg), DOI (0.1 mg/kg), ALT (1 mg/kg) or the respective vehicle (saline, DMSO), rats underwent an object and place recognition memory test in the open field. Upon the assessment of object exploration, motor/exploratory parameters and feces excretion, rats were administered the monoamine transporter radioligand N-o-fluoropropyl-2b-carbomethoxy-3b-(4-[I]iodophenyl)-nortropane ([I]-FP-CIT; 8.9 ± 2.6 MBq) into the tail vein. Regional radioactivity accumulations in the rat brain were determined post mortem. Compared vehicle, administration of 8-OH-DPAT impaired memory for place, decreased rearing behavior, and increased ambulation as well as head-shoulder movements. DOI administration led to a reduction in rearing behavior but an increase in head-shoulder motility relative to vehicle. Feces excretion was diminished after ALT relative to vehicle. Dopamine transporter (DAT) binding was increased in the caudateputamen (CP), but decreased in the nucleus accumbens (NAC) after 8-OH-DPAT relative to vehicle. Moreover, DAT binding was decreased in the NAC after ALT relative to vehicle. Findings indicate that 5-HTR inhibition and 5-HTR activation may impair memory for place. Furthermore, results imply associations not only between recognition memory, motor/exploratory behavior and emotionality but also between the respective parameters and the levels of available DA in CP and NAC.
Topics: Animals; Dopamine Plasma Membrane Transport Proteins; Male; Recognition, Psychology; Exploratory Behavior; Rats; Receptor, Serotonin, 5-HT1A; Receptor, Serotonin, 5-HT2A; Motor Activity; Brain; Emotions; Serotonin 5-HT1 Receptor Agonists; Serotonin 5-HT2 Receptor Agonists; Rats, Wistar
PubMed: 38777263
DOI: 10.1016/j.bbr.2024.115051 -
Scientific Reports May 2024Mitochondrial diseases are mainly caused by dysfunction of mitochondrial respiratory chain complexes and have a variety of genetic variants or phenotypes. There are only...
Mitochondrial diseases are mainly caused by dysfunction of mitochondrial respiratory chain complexes and have a variety of genetic variants or phenotypes. There are only a few approved treatments, and fundamental therapies are yet to be developed. Leigh syndrome (LS) is the most severe type of progressive encephalopathy. We previously reported that apomorphine, an anti- "off" agent for Parkinson's disease, has cell-protective activity in patient-derived skin fibroblasts in addition to strong dopamine agonist effect. We obtained 26 apomorphine analogs, synthesized 20 apomorphine derivatives, and determined their anti-cell death effect, dopamine agonist activity, and effects on the mitochondrial function. We found three novel apomorphine derivatives with an active hydroxy group at position 11 of the aporphine framework, with a high anti-cell death effect without emetic dopamine agonist activity. These synthetic aporphine alkaloids are potent therapeutics for mitochondrial diseases without emetic side effects and have the potential to overcome the low bioavailability of apomorphine. Moreover, they have high anti-ferroptotic activity and therefore have potential as a therapeutic agent for diseases related to ferroptosis.
Topics: Leigh Disease; Humans; Mitochondria; Aporphines; Fibroblasts; Apomorphine; Dopamine Agonists; Alkaloids
PubMed: 38773300
DOI: 10.1038/s41598-024-62445-w -
European Journal of Endocrinology Jun 2024The aim of this study is to compare the response to first-line medical treatment in treatment-naive acromegaly patients with pure growth hormone (GH)-secreting pituitary...
OBJECTIVE
The aim of this study is to compare the response to first-line medical treatment in treatment-naive acromegaly patients with pure growth hormone (GH)-secreting pituitary adenoma (GH-PA) and those with GH and prolactin cosecreting PA (GH&PRL-PA).
DESIGN
This is a retrospective multicentric study of acromegaly patients followed from 2003 to 2023 in 33 tertiary Spanish hospitals with at least 6 months of first-line medical treatment.
METHODS
Baseline characteristics, first-line medical treatment strategies, and outcomes were analyzed. We employed a multiple logistic regression full model to estimate the impact of some baseline characteristics on disease control after each treatment modality.
RESULTS
Of the 144 patients included, 72.9% had a GH-PA, and 27.1% had a GH&PRL-PA. Patients with GH&PRL-PA were younger (43.9 ± 15.0 vs 51.9 ± 12.7 years, P < .01) and harboring more frequently macroadenomas (89.7% vs 72.1%, P = .03). First-generation somatostatin receptor ligand (fgSRL) as monotherapy was given to 106 (73.6%) and a combination treatment with fgSRL and cabergoline in the remaining 38 (26.4%). Patients with GH&PRL-PA received more frequently a combination therapy (56.4% vs 15.2%, P < .01). After 6 months of treatment, in the group of patients under fgSRL as monotherapy, those patients with GH&PRL-PA had worse control compared to GH-PAs (29.4% vs 55.1%, P = .04). However, these differences in the rate of disease control between both groups disappeared when both received combination treatment with fgSRL and cabergoline.
CONCLUSION
In GH&PRL-PA, the biochemical control achieved with fgSRL as monotherapy is substantially worse than in patients harboring GH-PA, supporting the inclusion of cabergoline as first-line medical treatment in combination with fgSRLs in these subgroups of patients.
Topics: Humans; Acromegaly; Female; Male; Middle Aged; Retrospective Studies; Adult; Cabergoline; Treatment Outcome; Prolactin; Growth Hormone-Secreting Pituitary Adenoma; Human Growth Hormone; Adenoma; Aged; Drug Therapy, Combination; Somatostatin; Pituitary Neoplasms; Spain
PubMed: 38771697
DOI: 10.1093/ejendo/lvae053 -
Parkinson's Disease 2024Heightened trait impulsivity in both subclinical and pathological senses is becoming increasingly recognised in Parkinson's disease (PD). Impulsive behaviours and... (Review)
Review
Heightened trait impulsivity in both subclinical and pathological senses is becoming increasingly recognised in Parkinson's disease (PD). Impulsive behaviours and impulse control disorders (ICDs) are a consequence of perturbation to the rewards pathway leading individuals to conduct activities in a repetitive, excessive, and maladaptive fashion. Commonly linked to PD, heightened trait impulsivity has been found to primarily manifest in the forms of hypersexuality, pathological gambling, compulsive shopping, and binge eating, all of which may significantly impact social and financial standing. Subsequent burden to quality of life for both individuals with PD and caregivers are common. Although risk factors and indicators for ICDs in PD are currently lacking, it is recognised that the condition is often precipitated by dopamine replacement therapies, primarily dopamine agonist administration. While this nonmotor symptom is being increasingly diagnosed in PD populations, it remains relatively elusive in comparison to its motor counterparts. Through discussion of impulsivity characteristics, neuroanatomy, and neurochemistry, in addition to reviewing existing research on the potential contributing factors to impulsivity in PD, this review highlights impulsivity as a significant and detrimental PD symptom. Thus, emphasising the imperative need to establish efficacious diagnostic tools and treatments.
PubMed: 38766569
DOI: 10.1155/2024/8770997 -
Carbohydrate Polymers Aug 2024Transdermal rotigotine (RTG) therapy is prescribed to manage Parkinson's disease (Neupro® patch). However, its use is suffered from application site reactions. Herein,...
Transdermal rotigotine (RTG) therapy is prescribed to manage Parkinson's disease (Neupro® patch). However, its use is suffered from application site reactions. Herein, drug nanocrystalline suspension (NS)-loaded hydrogel (NS-HG) employing polysaccharides simultaneously as suspending agent and hydrogel matrix was constructed for transdermal delivery, with alleviated skin irritation. RTG-loaded NS-HG was prepared using a bead-milling technique, employing sodium carboxylmethyl cellulose (Na.CMC) as nano-suspending agent (molecular weight 90,000 g/mol) and hydrogel matrix (700,000 g/mol), respectively. NS-HG was embodied as follows: drug loading: ≤100 mg/mL; shape: rectangular crystalline; crystal size: <286.7 nm; zeta potential: -61 mV; viscosity: <2.16 Pa·s; and dissolution rate: >90 % within 15 min. Nuclear magnetic resonance analysis revealed that the anionic polymers bind to RTG nanocrystals via charge interaction, affording uniform dispersion in the matrix. Rodent transdermal absorption of RTG from NS-HG was comparable to that from microemulsions, and proportional to drug loading. Moreover, NS-HG was skin-friendly; erythema and epidermal swelling were absent after repeated application. Further, NS-HG was chemically stable; >95 % of the drug was preserved up to 4 weeks under long term (25 °C/RH60%), accelerated (40 °C/RH75%), and stress (50 °C) storage conditions. Therefore, this novel cellulose derivative-based nanoformulation presents a promising approach for effective transdermal RTG delivery with improved tolerability.
Topics: Thiophenes; Animals; Hydrogels; Nanoparticles; Carboxymethylcellulose Sodium; Administration, Cutaneous; Tetrahydronaphthalenes; Skin; Male; Skin Absorption; Rats; Mice; Drug Carriers; Rats, Sprague-Dawley; Drug Liberation
PubMed: 38763711
DOI: 10.1016/j.carbpol.2024.122197 -
Sleep Medicine Jul 2024Dopamine agonists (DAs) constitute the standard therapeutic scheme for restless leg syndrome (RLS) because they have been proven to be effective. However, DAs may change... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Dopamine agonists (DAs) constitute the standard therapeutic scheme for restless leg syndrome (RLS) because they have been proven to be effective. However, DAs may change sleep parameters, thus having adverse effects on patient condition. This meta-analysis clarified the effects of DAs used in RLS treatment on the sleep architecture.
METHODS
PubMed, Embase, and Cochrane Central databases were searched for randomized control trials (RCT) (up to October 2023) that discussed the effects of DAs on sleep architecture in patients with RLS. A meta-analysis employing a random-effects model was conducted. The patients were divided into subgroups according to individual DAs and treatment duration (1 day or ≥4 weeks).
RESULTS
Thirteen eligible randomized placebo-controlled trials were included in the assessment. The effects of three DAs (i.e., pramipexole, ropinirole, and rotigotine) on rapid eye movement (REM) sleep, slow-wave sleep (SWS), and sleep efficiency (SE) were analyzed. Overall, pramipexole significantly improved SE but decreased the percentage of REM sleep among treated patients. Ropinirole also enhanced SE compared with the placebo group. Rotigotine did not affect SE and REM sleep. Subgroup analysis found that pramipexole used for 1 day and ≥4 weeks significantly diminished the percentage of REM sleep. Ropinirole used for 1 day showed similar REM sleep patterns. Finally, none of the three DAs affected SWS.
CONCLUSIONS
This meta-analysis demonstrated that DAs significantly affect sleep parameters.
Topics: Restless Legs Syndrome; Humans; Dopamine Agonists; Pramipexole; Randomized Controlled Trials as Topic; Tetrahydronaphthalenes; Sleep, REM; Indoles; Thiophenes
PubMed: 38761607
DOI: 10.1016/j.sleep.2024.05.011 -
Journal of Neuro-oncology Jun 2024Functioning pituitary adenomas (FPAs) include most frequently prolactinomas, somatotroph or corticotroph adenomas, while thyrotroph and gonadotroph adenomas are very... (Review)
Review
CONTEXT
Functioning pituitary adenomas (FPAs) include most frequently prolactinomas, somatotroph or corticotroph adenomas, while thyrotroph and gonadotroph adenomas are very rare. Despite their benign histological nature (aggressive tumors are rare and malignant ones exceptional), FPAs could cause significant morbidity and increased mortality due to complications associated with hormonal excess syndromes and/or mass effect leading to compression of adjacent structures. This mini review will focus on the increasing role of medical therapy in the multimodal treatment, which also includes transsphenoidal surgery (TSS) and radiotherapy.
EVIDENCE SYNTHESIS
Most patients with prolactinomas are treated only with medications, but surgery could be considered for some patients in a specialized pituitary center, if higher chances of cure. Dopamine agonists, especially cabergoline, are efficient in reducing tumor size and normalizing prolactin. TSS is the first-line treatment for all other FPAs, but most patients require complex adjuvant treatment, including a combination of therapeutic approaches. Medical therapy is the cornerstone of treatment in all patients after unsuccessful surgery or when surgery cannot be offered and includes somatostatin receptor ligands and dopamine agonists (almost all FPAs), growth hormone receptor antagonists (acromegaly), adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers (Cushing's disease). Novel medical treatments, especially for acromegaly and Cushing's disease are under research.
CONCLUSIONS
An enlarged panel of effective drugs available with increased knowledge of predictive factors for response and/or adverse effects will enhance the possibility to offer a more individualized treatment. This would not only improve disease control and prognosis, but also quality of life.
Topics: Humans; Pituitary Neoplasms; Adenoma; Combined Modality Therapy; Clinical Trials as Topic
PubMed: 38760632
DOI: 10.1007/s11060-024-04670-x