Project description:Selective serotonin reuptake inhibitors (SSRIs) are antidepressants used for the treatment of mood and anxiety disorders. Here, we demonstrate that incubation (2 h) of murine islets or Min6 ? cell line with the SSRIs paroxetine, fluoxetine, or sertraline inhibited insulin-induced Tyr phosphorylation of insulin receptor substrate (IRS)-2 protein and the activation of its downstream targets Akt and the ribosomal protein S6 kinase-1 (S6K1). Inhibition was dose-dependent with half-maximal effects at ?15-20 ?M. It correlated with a rapid dephosphorylation and activation of the IRS kinase GSK3?. Introduction of GSK3? siRNAs eliminated the inhibitory effects of the SSRIs. Inhibition of IRS-2 action by 30 ?M SSRI was associated with a marked inhibition of glucose-stimulated insulin secretion from murine and human pancreatic islets. Secretion induced by basic secretagogues (KCl and Arg) was not affected by these drugs. Prolonged treatment (16 h) of Min6 cells with sertraline resulted in the induction of inducible nitric oxide synthase; activation of endoplasmic reticulum stress, and the initiation of the unfolded protein response, manifested by enhanced transcription of ATF4 and C/EBP homologous protein. This triggered an apoptotic process, manifested by enhanced caspase 3/7 activity, which resulted in ? cell death. These findings implicate SSRIs as inhibitors of IRS protein function and insulin action through the activation of GSK3?. They further suggest that SSRIs inhibit insulin secretion; induce the unfolded protein response; activate an apoptotic process, and trigger ? cell death. Given that SSRIs promote insulin resistance while inhibiting insulin secretion, these drugs might accelerate the transition from an insulin-resistant state to overt diabetes.
Project description:Background: The use of selective serotonin reuptake inhibitors (SSRIs) has been associated with potential effects on male fertility, although the exact mechanisms are not fully understood. The aim of this study was to understand the relationship between SSRIs and male infertility; Methods: A retrospective chart review of Saudi males who were treated with SSRIs and attended an infertility clinic in KSMC was undertaken. The medical records of men from an infertility clinic were reviewed to screen the quality of the sperm parameters in patients taking SSRIs; Results: In total, 299 men were identified, of whom 29 (9.6%) were exposed to SSRIs, while 270 (90.4%) did not receive SSRIs, defined as the control infertile group. When comparing the mean ages, a notable disparity was observed between the control group of infertile men (34.2 ± 6.9 years) and the infertile group using SSRIs (41.5 ± 3.2 years) (p < 0.001). Regarding the sperm analysis and the use of SSRIs, the impact of SSRIs use showed no significant differences in sperm liquefaction (p = 0.1), motility (p = 0.17), viscosity (p = 0.16), or count (p = 0.069) with escitalopram, fluoxetine, or paroxetine use; Conclusions: Our study showed no significant difference in the sperm analysis between the SSRI and non-SSRI cohorts. However, the relationship between SSRI use and sperm count warrants further investigation and consideration in clinical practice.
Project description:BackgroundThe therapeutic use of [131I]meta-iodobenzylguanidine ([131I]MIBG) is often accompanied by hematological toxicity, mainly consisting of persistent and severe thrombocytopenia. While MIBG accumulates in neuroblastoma cells via selective uptake by the norepinephrine transporter (NET), the serotonin transporter (SERT) is responsible for cellular uptake of MIBG in platelets. In this study, we have investigated whether pharmacological intervention with selective serotonin reuptake inhibitors (SSRIs) may prevent radiotoxic MIBG uptake in platelets without affecting neuroblastoma tumor uptake.MethodsTo determine the transport kinetics of SERT for [125I]MIBG, HEK293 cells were transfected with SERT and uptake assays were conducted. Next, a panel of seven SSRIs was tested in vitro for their inhibitory potency on the uptake of [125I]MIBG in isolated human platelets and in cultured neuroblastoma cells. We investigated in vivo the efficacy of the four best performing SSRIs on the accumulation of [125I]MIBG in nude mice bearing subcutaneous neuroblastoma xenografts. In ex vivo experiments, the diluted plasma of mice treated with SSRIs was added to isolated human platelets to assess the effect on [125I]MIBG uptake.ResultsSERT performed as a low-affinity transporter of [125I]MIBG in comparison with NET (Km = 9.7??M and 0.49??M, respectively). Paroxetine was the most potent uptake inhibitor of both serotonin (IC50 = 0.6?nM) and MIBG (IC50 = 0.2?nM) in platelets. Citalopram was the most selective SERT inhibitor of [125I]MIBG uptake, with high SERT affinity in platelets (IC50 = 7.8?nM) and low NET affinity in neuroblastoma cells (IC50 = 11.940?nM). The in vivo tested SSRIs (citalopram, fluvoxamine, sertraline, and paroxetine) had no effect on [125I]MIBG uptake levels in neuroblastoma xenografts. In contrast, treatment with desipramine, a NET selective inhibitor, resulted in profoundly decreased xenograft [125I]MIBG levels (p < 0.0001). In ex vivo [125I]MIBG uptake experiments, 100- and 34-fold diluted murine plasma of mice treated with citalopram added to isolated human platelets led to a decrease in MIBG uptake of 54-76%, respectively.ConclusionOur study demonstrates for the first time that SSRIs selectively inhibit MIBG uptake in platelets without affecting MIBG accumulation in an in vivo neuroblastoma model. The concomitant application of citalopram during [131I]MIBG therapy seems a promising strategy to prevent thrombocytopenia in neuroblastoma patients.
Project description:Antiinflammatory drugs achieve their therapeutic actions at least in part by regulation of cytokine formation. A "cytokine hypothesis" of depression is supported by the observation that depressed individuals have elevated plasma levels of certain cytokines compared with healthy controls. Here we investigated a possible interaction between antidepressant agents and antiinflammatory agents on antidepressant-induced behaviors and on p11, a biochemical marker of depressive-like states and antidepressant responses. We found that widely used antiinflammatory drugs antagonize both biochemical and behavioral responses to selective serotonin reuptake inhibitors (SSRIs). In contrast to the levels detected in serum, we found that frontal cortical levels of certain cytokines (e.g., TNFα and IFNγ) were increased by serotonergic antidepressants and that these effects were inhibited by antiinflammatory agents. The antagonistic effect of antiinflammatory agents on antidepressant-induced behaviors was confirmed by analysis of a dataset from a large-scale real-world human study, "sequenced treatment alternatives to relieve depression" (STAR*D), underscoring the clinical significance of our findings. Our data indicate that clinicians should carefully balance the therapeutic benefits of antiinflammatory agents versus the potentially negative consequences of antagonizing the therapeutic efficacy of antidepressant agents in patients suffering from depression.
Project description:Hybrid nitrate drugs have been reported to provide NO bioactivity to ameliorate side effects or to provide ancillary therapeutic activity. Hybrid nitrate selective serotonin reuptake inhibitors (NO-SSRIs) were prepared to improve the therapeutic profile of this drug class. A synthetic strategy for use of a thiocarbamate linker was developed, which in the case of NO-fluoxetine facilitated hydrolysis to fluoxetine at pH 7.4 within 7 hours. In cell culture, NO-SSRIs were weak inhibitors of the serotonin transporter, however, in the forced swimming task (FST) in rats, NO-fluoxetine demonstrated classical antidepressant activity. Comparison of NO-fluoxetine, with fluoxetine, and an NO-chimera nitrate developed for Alzheimer's disease (GT-1061), was made in the step through passive avoidance (STPA) test of learning and memory in rats treated with scopolamine as an amnesic agent. Fluoxetine was inactive, whereas NO-fluoxetine and GT-1061 both restored long-term memory. GT-1061 also produced antidepressant behavior in FST. These data support the potential for NO-SSRIs to overcome the lag in onset of therapeutic action and provide co-therapy of neuropathologies concomitant with depression.
Project description:Given the failure to develop disease-modifying therapies for Alzheimer's disease (AD), strategies aiming at preventing or delaying the onset of the disease are being prioritized. While the debate regarding whether depression is an etiological risk factor or a prodrome of AD rages on, a key determining factor may be the timing of depression onset in older adults. There is increasing evidence that untreated early-onset depression is a risk factor and that late-onset depression may be a catalyst of cognitive decline. Data from animal studies have shown a beneficial impact of selective serotonin reuptake inhibitors on pathophysiological biomarkers of AD including amyloid burden, tau deposits and neurogenesis. In humans, studies focusing on subjects with a prior history of depression also showed a delay in the onset of AD in those treated with most selective serotonin reuptake inhibitors. Paroxetine, which has strong anticholinergic properties, was associated with increased mortality and mixed effects on amyloid and tau deposits in mice, as well as increased odds of developing AD in humans. Although most of the data regarding selective serotonin reuptake inhibitors is promising, findings should be interpreted cautiously because of notable methodological heterogeneity between studies. There is thus a need to conduct large scale randomized controlled trials with long follow up periods to clarify the dose-effect relationship of specific serotonergic antidepressants on AD prevention.
Project description:There has been a growing interest in the potential for plasticity-inducing pharmacological interventions to enhance post-stroke recovery. One group of drugs that continues to garner a great deal of attention in this regard is a class of antidepressants called the selective serotonin reuptake inhibitors. Here we propose a model for the mechanism by which these drugs may enhance plasticity after ischemic brain injury. First, we review the research in animal models demonstrating how selective serotonin reuptake inhibitors reopen the critical period for ocular dominance plasticity in adulthood. We then compare this period of heightened plasticity to the cellular and biochemical milieu of perilesional tissue after an ischemic event in the adult brain. We argue that selective serotonin reuptake inhibitors administered acutely after an ischemic stroke alter excitatory-inhibitory balance in perilesional tissue and reinstate a type of plasticity reminiscent of the critical period in development. Finally, we discuss opportunities for future research in this area in both the preclinical and clinical realms.
Project description:Objective: To explore the efficacy and tolerability of selective serotonin reuptake inhibitors (SSRIs) for motor recovery in non-depressed patients after acute stroke. Methods: According to the predefined retrieval strategy, multiple electronic databases were searched for randomized controlled trials (RCTs) that met the inclusion criteria. The primary efficacy outcome was measured by Fugl-Meyer Motor Scale (FMMS) score and the indicators of tolerability included withdrawal rate and the incidence of adverse events (AEs). Results: 10RCTs were included, the pooled analyses showed patients who received fluoxetine (endpoint: MD = 21.17, 95% CI 14.13-28.21, P < 0.00001; mean change: MD = 16.27, 95% CI 10.05-22.50, P < 0.00001) and citalopram (endpoint: MD = 22.93, 95% CI 11.13-34.73, P = 0.0001; mean change: MD = 24.06, 95% CI 10.47-37.65, P = 0.0005) experienced greater improvement in FMMS score. There was no evident difference in total withdrawal rate (fluoxetine: OR = 1.11, 95% CI 0.90-1.27, P = 1.38; citalopram: OR = 0.94, 95% CI 0.69-1.28, P = 0.71; escitalopram: OR = 0.87, 95% CI 0.58-1.28, P = 0.47) between two groups. Besides, the incidence of hyponatremia (OR = 2.01, 95% CI 1.16-3.50, P = 0.01), seizure (OR = 1.46, 95% CI 1.03-2.08, P = 0.04) and fracture (OR = 2.34, 95% CI 1.61-3.40, P < 0.00001) in the fluoxetine group was higher than in the placebo group. Conclusions: Fluoxetine and citalopram can promote motor recovery in non-depressed patients with acute stroke, but it is necessary to pay attention to the possible AEs of fluoxetine, such as hyponatremia, seizure and fracture. Systematic Review Registration: PROSPERO, identifier [CRD42021227452].
Project description:The physiology of mood regulation in the postpartum is poorly understood despite the fact that postpartum depression (PPD) is a common pathology. Serotonergic mechanisms and their dysfunction are widely presumed to be involved, which has led us to investigate whether lactation induces changes in central or peripheral serotonin (5-HT) systems and related affective behaviors. Brain sections from lactating (day 10 postpartum) and age-matched nulliparous (non-pregnant) C57BL/6J mice were processed for 5-HT immunohistochemistry. The total number of 5-HT immunostained cells and optical density were measured. Lactating mice exhibited lower immunoreactive 5-HT and intensity in the dorsal raphe nucleus when compared with nulliparous controls. Serum 5-HT was quantified from lactating and nulliparous mice using radioimmunoassay. Serum 5-HT concentrations were higher in lactating mice than in nulliparous controls. Affective behavior was assessed in lactating and non-lactating females ten days postpartum, as well as in nulliparous controls using the forced swim test (FST) and marble burying task (MBT). Animals were treated for the preceding five days with a selective serotonin reuptake inhibitor (SSRI, citalopram, 5mg/kg/day) or vehicle. Lactating mice exhibited a lower baseline immobility time during the FST and buried fewer marbles during the MBT as compared to nulliparous controls. Citalopram treatment changed these behaviors in lactating mice with further reductions in immobility during the FST and decreased marble burying. In contrast, the same regimen of citalopram treatment had no effect on these behaviors in either non-lactating postpartum or nulliparous females. Our findings demonstrate changes in both central and peripheral 5-HT systems associated with lactation, independent of pregnancy. They also demonstrate a significant interaction of lactation and responsiveness to SSRI treatment, which has important implications in the treatment of PPD. Although recent evidence has cast doubt on the effectiveness of SSRIs, these results support their therapeutic use in the treatment of PPD.