There is growing evidence that the imbalance between oxidative stress and the antioxidant defense system may
be associated with the development neuropsychiatric disorders, such as depression and ...anxiety. Major depression and
anxiety are presently correlated with a lowered total antioxidant state and by an activated oxidative stress (OS) pathway.
The classical antidepressants may produce therapeutic effects other than regulation of monoamines by increasing the
antioxidant levels and normalizing the damage caused by OS processes. This chapter provides an overview of recent work
on oxidative stress markers in the animal models of depression and anxiety, as well as patients with the aforementioned
mood disorders. It is well documented that antioxidants can remove the reactive oxygen species (ROS) and reactive
nitrogen species (RNS) through scavenging radicals and suppressing the OS pathway, which further protect against
neuronal damage caused oxidative or nitrosative stress sources in the brain, hopefully resulting in remission of depression
or anxiety symptoms. The functional understanding of the relationship between oxidative stress and depression and
anxiety may pave the way for discovery of novel targets for treatment of neuropsychiatric disorders.
•Bay 60-7550 exhibits antidepressant- and anxiolytic-like effects in mouse behaviors.•Increased cGMP signaling may contribute to the protective effects of Bay 60-7550.•Bay 60-7550 is able to ...antagonize the oxidative damage produced by chronic stress.•Another possible mechanism of Bay 60-7550's function is its anti-apoptotic effects.
Stress occurs in everyday life, but the relationship between stress and the onset or development of depression/anxiety remains unknown. Increasing evidence suggests that the impairment of antioxidant defense and the neuronal cell death are important in the process of emotional disorders. Chronic stress impairs the homeostasis of antioxidants/oxidation, which results in the aberrant stimulation of the cell cycle proteins where cGMP-PKG signaling is thought to have an inhibitory role. Phosphodiesterase 2 (PDE2) is linked to cGMP-PKG signaling and highly expressed in the limbic brain regions including hippocampus and amygdala, which may play important roles in the treatment of depression and anxiety. To address the possible effects of PDE2 inhibitors on depression-/anxiety-like behaviors and the underlying mechanisms, Bay 60-7550 (0.75, 1.5 and 3mg/kg, i.p.) was administered 30min before chronic stress. The results suggested that Bay 60-7550 not only restored the behavioral changes but also regulated Cu/Zn superoxide dismutase (SOD) levels differentially in hippocampus and amygdala, which were increased in the hippocampus while decreased in the amygdala. It was also significant that Bay 60-7550 regulated the abnormalities of pro- and anti-apoptotic components, such as Bax, Caspase 3 and Bcl-2, and the indicator of PKG signaling characterized by pVASPser239, in these two brain regions. The results suggested that Bay 60-7550 is able to alleviate oxidative stress and mediate part of the apoptotic machinery in neuronal cells possibly through SOD-cGMP/PKG-anti-apoptosis signaling and that inhibition of PDE2 may represent a novel therapeutic target for psychiatric disorders, such as depression and anxiety.
Pharmacological inhibition of type 4 cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase (PDE4) produces antidepressant-like effects in animals; however, it is not known which of the ...four PDE4 subtypes mediates these actions. In the present study, immunoblot analysis showed loss of phosphodiesterase 4D (PDE4D) expression in the cerebral cortex and hippocampus of PDE4D knockout (PDE4D-/-) mice, but unchanged PDE4A and PDE4B expression, relative to the wild type (PDE4D+/+) and heterozygous knockout (PDE4D+/-) mice. This reduced expression was accompanied by a reduction in PDE4 activity, while non-PDE4 activity was unchanged. PDE4D-/- mice exhibited decreased immobility in tail-suspension and forced-swim tests, which is indicative of an antidepressant-like effect on behavior. Desipramine and fluoxetine produced similar antidepressant-like effects in all three genotypes, even though their behavioral baselines differed markedly. By contrast, the PDE4 inhibitor rolipram only produced antidepressant-like effects in PDE4D+/+ mice. Consistent with this, rolipram potentiated isoproterenol-induced cyclic AMP formation only in the PDE4D+/+ mice. These results suggest that PDE4D is an essential mediator of the antidepressant-like effects of rolipram, and that PDE4D-regulated cyclic adenosine monophosphate signaling may play a role in the pathophysiology and pharmacotherapy of depression.
Background and Purpose
Phosphodiesterase 4 (PDE4) inhibitors produce potent antidepressant‐like and cognition‐enhancing effects. However, their clinical utility is limited by the major side effect of ...emesis, which appears to be PDE4 isoform‐specific. Although PDE4D subtype plays the pivotal role in these therapeutic profiles, it is also the primary subtype responsible for emesis. Therefore, the aim of present research was to investigate whether long‐form PDE4D variants mediate antidepressant‐like and cognition‐enhancing effects, but are irrespective with emesis.
Experimental Approach
In mice microinfused with lentiviral vectors that contained shRNA‐mir hairpin structure targeting long‐form PDE4Ds into bilateral prefrontal cortices, the tail‐suspension and forced‐swim tests were used to measure antidepressant‐like effects; novel object recognition and Morris water‐maze tasks were used to determine cognition‐enhancing effects. The emetic potential was assessed by alpha2 adrenergic receptor‐mediated anaesthesia, a surrogate measure of emesis. Intracellular cAMP signalling was analysed by time‐resolved FRET immunoassay and Western‐blot. Dendritic complexity was assessed by Golgi staining.
Key Results
Microinfusions of lentiviral PDE4D‐shRNA down‐regulated PDE4D4 and PDE4D5, and imitated the antidepressant‐like and cognition‐enhancing effects of the prototypical PDE4 inhibitor rolipram. The behavioural effects were related to dendritic complexity and mediated by the increased cAMP signalling. In addition, these effects were not enhanced in the presence of rolipram. Finally, while rolipram shortened the duration of combined anaesthesia, RNA interference‐mediated PDE4D knock‐down in the prefrontal cortex did not.
Conclusion and Implications
These data suggest that long‐form PDE4Ds, at least PDE4D4 and PDE4D5, may be the promising targets for the development of PDE4 variant‐selective inhibitors as the new pharmacotherapies for depressive disorders and neurodegenerative diseases involving memory deficits.
Behavior maintained under a differential-reinforcement-of-low-rate (DRL) 72-s operant schedule, which reinforces responses with interresponse times greater than 72
s, exhibits a rather unique ...sensitivity to antidepressant drugs. Antidepressants from a number of pharmacological classes, including tricyclic antidepressants, selective serotonin or norepinephrine reuptake inhibitors, monoamine oxidase inhibitors, as well as a number of atypical antidepressants and putative antidepressants, reduce response rate and increase reinforcement rate of rats under this schedule. These effects are observed acutely but persist or are augmented with repeated treatment. By contrast, drugs from a number of other psychotherapeutic classes do not, in general, produce similar effects. This includes anxiolytic, sedative, stimulant, opioid, antihistaminic, and anticholinergic drugs, which can produce false positive results in some preclinical tests for antidepressant efficacy. There are conflicting data regarding the utility of DRL behavior for discriminating the effects of antidepressant and antipsychotic drugs. This results in part from methodological differences among studies, but likely also reflects the overlap between the neuropharmacological and clinical effects of some antipsychotic and antidepressant drugs. DRL behavior also has proven useful for identifying neurochemical and neuroanatomical mediators of antidepressant effects on behavior. Consistent with clinical data, it appears that activation of noradrenergic or serotonergic systems provides for parallel means of producing antidepressant-like effects on DRL behavior. Finally, the results of studies using DRL behavior highlight important roles for central beta-1 adrenergic receptors, as well as 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT2C receptors, in the mediation of antidepressant-like behavioral effects.
Hypertension is the most common cause of left ventricular (LV) hypertrophy. However, multiple causes can lead to LV hypertrophy, each of which has different histological and mechanical properties. To ...assess the value of a novel speckle-tracking echocardiographic measurement of myocardial strain and strain rate in defining the mechanical properties of LV hypertrophy, 20 patients with asymmetric hypertrophic cardiomyopathy, 24 patients with secondary LV hypertrophy, 12 patients with biopsy-proved confirmed cardiac amyloidosis, and 22 age-matched healthy asymptomatic volunteers were studied. Patients with amyloidosis had severe diastolic dysfunction, and myocardial deformation was significantly decreased. The new technique allowed cardiac amyloid to be easily differentiated from the other categories. In patients with hypertrophic cardiomyopathy, there was segmental myocardium dysfunction as assessed by strain imaging. LV global systolic velocity and radial displacement were higher, and abnormal relaxation was more frequent, in the group with secondary LV hypertrophy than in normal controls. In conclusion, the observations from strain parameters derived from speckle tracking were consistent with the known underlying pathology of each condition, which speaks to the value of strain imaging. Cardiac amyloid profoundly alters all strain parameters, and analysis of these parameters could aid in the diagnosis.
Excessive inflammation-associated coagulation is a feature of infectious diseases, occurring in such conditions as bacterial sepsis and COVID-19. It can lead to disseminated intravascular ...coagulation, one of the leading causes of mortality worldwide. Recently, type I interferon (IFN) signaling has been shown to be required for tissue factor (TF; gene name F3) release from macrophages, a critical initiator of coagulation, providing an important mechanistic link between innate immunity and coagulation. The mechanism of release involves type I IFN-induced caspase-11 which promotes macrophage pyroptosis. Here we find that F3 is a type I IFN-stimulated gene. Furthermore, F3 induction by lipopolysaccharide (LPS) is inhibited by the anti-inflammatory agents dimethyl fumarate (DMF) and 4-octyl itaconate (4-OI). Mechanistically, inhibition of F3 by DMF and 4-OI involves suppression of Ifnb1 expression. Additionally, they block type I IFN- and caspase-11-mediated macrophage pyroptosis, and subsequent TF release. Thereby, DMF and 4-OI inhibit TF-dependent thrombin generation. In vivo, DMF and 4-OI suppress TF-dependent thrombin generation, pulmonary thromboinflammation, and lethality induced by LPS, E. coli, and S. aureus, with 4-OI additionally attenuating inflammation-associated coagulation in a model of SARS-CoV-2 infection. Our results identify the clinically approved drug DMF and the pre-clinical tool compound 4-OI as anticoagulants that inhibit TF-mediated coagulopathy via inhibition of the macrophage type I IFN-TF axis.
Objectives
To establish the prevalence of pain and functional disability in Irish adults with moderate and severe haemophilia, and to examine demographic and lifestyle influences.
Methods
Males ...≥18 years with moderate or severe haemophilia participated. Pain and function were examined using the PROBE questionnaire.
Results
Of 49 participants median age 44 (IQR 32, 52) years, most had severe haemophilia (Factor VIII = 30; Factor IX = 13) and were on regular prophylaxis (88%). Those with moderate haemophilia (Factor VIII = 5; Factor IX = 1) treated on demand (12%). Acute (72%) and chronic pain (71%), functional difficulties (58%), and analgesic requirements (92%) were prevalent. Age was significantly associated with more advanced haemophilic arthropathy (p = .002), chronic pain (p = .029) and functional difficulties (p = .036). Adults who reported chronic pain commenced prophylaxis significantly later in life 32 (20, 51) vs. 8 (1, 23) years; p = .004. Physical activity was significantly lower in those with functional difficulties (p < .05). A disparity between self‐perceived ‘target joints’ and clinically defined target joints was also identified (76% vs. 23%).
Conclusion
Haemophilic arthropathy, pain and functional disability were prevalent amongst Irish adults with moderate and severe haemophilia. Age‐dependent lifestyle, analgesic and treatment influences on pain and function warrant further investigation.
Terminal sialylation determines the plasma half-life of von Willebrand factor (VWF). A role for macrophage galactose lectin (MGL) in regulating hyposialylated VWF clearance has recently been ...proposed. In this study, we showed that MGL influences physiological plasma VWF clearance. MGL inhibition was associated with a significantly extended mean residence time and 3-fold increase in endogenous plasma VWF antigen levels (P<0.05). Using a series of VWF truncations, we further demonstrated that the A1 domain of VWF is predominantly responsible for enabling the MGL interaction. Binding of both full-length and VWF-A1-A2-A3 to MGL was significantly enhanced in the presence of ristocetin (P<0.05), suggesting that the MGL-binding site in A1 is not fully accessible in globular VWF. Additional studies using different VWF glycoforms demonstrated that VWF O-linked glycans, clustered at either end of the A1 domain, play a key role in protecting VWF against MGLmediated clearance. Reduced sialylation has been associated with pathological, increased clearance of VWF in patients with von Willebrand disease. Herein, we demonstrate that specific loss of α2-3 linked sialylation from O-glycans results in markedly increased MGL-binding in vitro, and markedly enhanced MGL-mediated clearance of VWF in vivo. Our data further show that the asialoglycoprotein receptor (ASGPR) does not have a significant role in mediating the increased clearance of VWF following loss of O-sialylation. Conversely however, we observed that loss of N-linked sialylation from VWF drives enhanced circulatory clearance predominantly via the ASGPR. Collectively, our data support the hypothesis that in addition to regulating physiological VWF clearance, the MGL receptor works in tandem with ASGPR to modulate enhanced clearance of aberrantly sialylated VWF in the pathogenesis of von Willebrand disease.
Physiologic and behavioral changes during pregnancy may alter HIV-1 susceptibility and infectiousness. Prospective studies exploring pregnancy and HIV-1 acquisition risk in women have found ...inconsistent results. No study has explored the effect of pregnancy on HIV-1 transmission risk from HIV-1-infected women to male partners.
In a prospective study of African HIV-1-serodiscordant couples, we evaluated the relationship between pregnancy and the risk of HIV-1 acquisition among women and HIV-1 transmission from women to men.
Three thousand three hundred and twenty-one HIV-1-serodiscordant couples were enrolled, 1085 (32.7%) with HIV-1 susceptible female partners and 2236 (67.3%) with susceptible male partners. HIV-1 incidence in women was 7.35 versus 3.01 per 100 person-years during pregnant and nonpregnant periods hazard ratio 2.34, 95% confidence interval (CI) 1.33-4.09. This effect was attenuated and not statistically significant after adjusting for sexual behavior and other confounding factors (adjusted hazard ratio 1.71, 95% CI 0.93-3.12). HIV-1 incidence in male partners of infected women was 3.46 versus 1.58 per 100 person-years when their partners were pregnant versus not pregnant (hazard ratio 2.31, 95% CI 1.22-4.39). This effect was not attenuated in adjusted analysis (adjusted hazard ratio 2.47, 95% CI 1.26-4.85).
HIV-1 risk increased two-fold during pregnancy. Elevated risk of HIV-1 acquisition in pregnant women appeared in part to be explained by behavioral and other factors. This is the first study to show that pregnancy increased the risk of female-to-male HIV-1 transmission, which may reflect biological changes of pregnancy that could increase HIV-1 infectiousness.
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