Ladostigil Reduces the Adenoside Triphosphate/Lipopolysaccharide-Induced Secretion of Pro-Inflammatory Cytokines from Microglia and Modulate-Immune Regulators, TNFAIP3, and EGR1

Treatment of aging rats for 6 months with ladostigil (1 mg/kg/day) prevented a decline in recognition and spatial memory and suppressed the overexpression of gene-encoding pro-inflammatory cytokines, TNFα, IL1β, and IL6 in the brain and microglial cultures. Primary cultures of mouse microglia stimulated by lipopolysaccharides (LPS, 0.75 µg/mL) and benzoyl ATPs (BzATP) were used to determine the concentration of ladostigil that reduces the secretion of these cytokine proteins. Ladostigil (1 × 10-11 M), a concentration compatible with the blood of aging rats in, prevented memory decline and reduced secretion of IL1β and IL6 by ≈50%. RNA sequencing analysis showed that BzATP/LPS upregulated 25 genes, including early-growth response protein 1, (Egr1) which increased in the brain of subjects with neurodegenerative diseases. Ladostigil significantly decreased Egr1 gene expression and levels of the protein in the nucleus and increased TNF alpha-induced protein 3 (TNFaIP3), which suppresses cytokine release, in the microglial cytoplasm. Restoration of the aberrant signaling of these proteins in ATP/LPS-activated microglia in vivo might explain the prevention by ladostigil of the morphological and inflammatory changes in the brain of aging rats.

AN1284 attenuates steatosis, lipogenesis, and fibrosis in mice with pre-existing non-alcoholic steatohepatitis and directly affects aryl hydrocarbon receptor in a hepatic cell line

Non-alcoholic steatohepatitis (NASH) is an aggressive form of fatty liver disease with hepatic inflammation and fibrosis for which there is currently no drug treatment. This study determined whether an indoline derivative, AN1284, which significantly reduced damage in a model of acute liver disease, can reverse steatosis and fibrosis in mice with pre-existing NASH and explore its mechanism of action. The mouse model of dietary-induced NASH reproduces most of the liver pathology seen in human subjects. This was confirmed by RNA-sequencing analysis. The Western diet, given for 4 months, caused steatosis, inflammation, and liver fibrosis. AN1284 (1 mg or 5 mg/kg/day) was administered for the last 2 months of the diet by micro-osmotic-pumps (mps). Both doses significantly decreased hepatic damage, liver weight, hepatic fat content, triglyceride, serum alanine transaminase, and fibrosis. AN1284 (1 mg/kg/day) given by mps or in the drinking fluid significantly reduced fibrosis produced by carbon tetrachloride injections. In human HUH7 hepatoma cells incubated with palmitic acid, AN1284 (2.1 and 6.3 ng/ml), concentrations compatible with those in the liver of mice treated with AN1284, decreased lipid formation by causing nuclear translocation of the aryl hydrocarbon receptor (AhR). AN1284 downregulated fatty acid synthase (FASN) and sterol regulatory element-binding protein 1c (SREBP-1c) and upregulated Acyl-CoA Oxidase 1 and Cytochrome P450-a1, genes involved in lipid metabolism. In conclusion, chronic treatment with AN1284 (1mg/kg/day) reduced pre-existing steatosis and fibrosis through AhR, which affects several contributors to the development of fatty liver disease. Additional pathways are also influenced by AN1284 treatment.

Coordinated Transcriptional Waves Define the Inflammatory Response of Primary Microglial Culture

The primary role of microglia is to maintain homeostasis by effectively responding to various disturbances. Activation of transcriptional programs determines the microglia's response to external stimuli. In this study, we stimulated murine neonatal microglial cells with benzoyl ATP (bzATP) and lipopolysaccharide (LPS), and monitored their ability to release pro-inflammatory cytokines. When cells are exposed to bzATP, a purinergic receptor agonist, a short-lived wave of transcriptional changes, occurs. However, only combining bzATP and LPS led to a sustainable and robust response. The transcriptional profile is dominated by induced cytokines (e.g., IL-1α and IL-1β), chemokines, and their membrane receptors. Several abundant long noncoding RNAs (lncRNAs) are induced by bzATP/LPS, including Ptgs2os2, Bc1, and Morrbid, that function in inflammation and cytokine production. Analyzing the observed changes through TNF (Tumor necrosis factor) and NF-κB (nuclear factor kappa light chain enhancer of activated B cells) pathways confirmed that neonatal glial cells exhibit a distinctive expression program in which inflammatory-related genes are upregulated by orders of magnitude. The observed capacity of the microglial culture to activate a robust inflammatory response is useful for studying neurons under stress, brain injury, and aging. We propose the use of a primary neonatal microglia culture as a responsive in vitro model for testing drugs that may interact with inflammatory signaling and the lncRNA regulatory network.

Emotional states as distinct configurations of functional brain networks

The conceptualization of emotional states as patterns of interactions between large-scale brain networks has recently gained support. Yet, few studies have directly examined the brain’s network structure during emotional experiences. Here, we investigated the brain’s functional network organization during experiences of sadness, amusement, and neutral states elicited by movies, in addition to a resting-state. We tested the effects of the experienced emotion on individual variability in the brain’s functional connectome. Next, for each state, we defined a community structure of the brain and quantified its segregation and integration. We found that sadness, relative to amusement, was associated with higher modular integration and increased connectivity of cognitive control networks: the salience and fronto-parietal networks. Moreover, in both the functional connectome and the emotional report, the similarity between individuals was dependent on the sex. Our results suggest that the experience of emotion is linked to a reconfiguration of whole-brain distributed, not emotion-specific, functional networks and that the brain’s topological structure carries information about the subjective emotional experience.

“It's always hard being a mom, but the pandemic has made everything harder”: A qualitative exploration of the experiences of perinatal women during the COVID-19 pandemic

Background

Understanding the psychosocial impacts of the COVID-19 pandemic in vulnerable groups, such as pregnant and parenting women, is a critical research and clinical imperative. Although many survey-based perinatal health studies have contributed important information about mental health, few have given full voice about the experiences of pregnant and postpartum women during the prolonged worldwide pandemic using a qualitative approach.

Objective

The purpose of this study is to explore the lived experience of pregnant and postpartum women in the United States during the ongoing COVID-19 pandemic.

Design

Qualitative phenomenological study.

Setting

This study was conducted in the community, by recruiting women throughout the U.S.

Participants

Fifty-four pregnant and postpartum women participated in qualitative interviews.

Methods

Data from one-on-one semi-structured interviews were analyzed using a team-based phenomenological qualitative approach.

Results

Two key themes were apparent: the pandemic has shined a light on the many typical struggles of motherhood; and, there is a lack of consistent, community-based or healthcare system resources available to address the complex needs of pregnant and postpartum women, both in general and during the pandemic.

Conclusions

Going forward, as the world continues to deal with the current pandemic and possible future global health crises, health care systems and providers are encouraged to consider the suggestions provided by these participants: talk early and often to women about mental health; help pregnant and postpartum women create and institute a personal plan for early support of their mental health needs and create an easily accessible mental health network; conceptualize practice methods that enhance coping and resilience; practice in community-based and interdisciplinary teams (e.g., midwives, doulas, perinatal social workers/ psychotherapists) to ensure continuity of care and to foster relationships between providers and pregnant/ postpartum women; and consider learning from other countries’ successful perinatal healthcare practices.

Registration

Number (& date of first recruitment): not applicable.

Tweetable abstract

Pregnant and postpartum women insist that mental health care must be overhauled, stating the pandemic has highlighted inherent cracks in the system.

Comparison of the tissue distribution and metabolism of AN1284, a potent anti-inflammatory agent, after subcutaneous and oral administration in mice

This study is to compare the tissue distribution and metabolism of AN1284 after subcutaneous and oral administration at doses causing maximal reductions in IL-6 in plasma and tissues of mice. Anti-inflammatory activity of AN1284 and its metabolites was detected in lipopolysaccharide (LPS) activated RAW 264.7 macrophages. Mice were given AN1284 by injection or gavage, 15 min before LPS. IL-6 protein levels were measured after 4 h. Using a liquid chromatography/mass spectrometry method we developed, we showed that AN1284 is rapidly metabolized to the indole (AN1422), a 7-OH derivative (AN1280) and its glucuronide. AN1422 has weaker anti-inflammatory activity than AN1284 in LPS-activated macrophages and in mice. AN1284 (0.5 mg/kg) caused maximal reductions in IL-6 in the plasma, brain, and liver when injected subcutaneously and after gavage only in the liver. Similar reductions in the plasma and brain required a dose of 2.5 mg/kg, which resulted in 5.5-fold higher hepatic levels than after injection of 0.5 mg/kg, but 7, 11, and 19-fold lower ones in the plasma, brain, and kidneys, respectively. Hepatic concentrations produced by AN1284 were 2.5 mg/kg/day given by subcutaneously implanted mini-pumps that were only 12% of the peak levels seen after acute injection of 0.5 mg/kg. Similar hepatic concentrations were obtained by (1 mg/kg/day), administered in the drinking fluid. These were sufficient to decrease hepatocellular damage and liver triglycerides in previous experiments in diabetic mice. AN1284 can be given orally by a method of continuous release to treat chronic liver disease, and its preferential concentration in the liver should limit any adverse effects.

Effect of ladostigil treatment of aging rats on gene expression in four brain areas associated with regulation of memory

Episodic and spatial memory decline in aging and are controlled by the hippocampus, perirhinal, frontal and parietal cortices and the connections between them. Ladostigil, a drug with antioxidant and anti-inflammatory activity, was shown to prevent the loss of episodic and spatial memory in aging rats. To better understand the molecular effects of aging and ladostigil on these brain regions we characterized the changes in gene expression using RNA-sequencing technology in rats aged 6 and 22 months. We found that the changes induced by aging and chronic ladostigil treatment were brain region specific. In the hippocampus, frontal and perirhinal cortex, ladostigil decreased the overexpression of genes regulating calcium homeostasis, ion channels and those adversely affecting synaptic function. In the parietal cortex, ladostigil increased the expression of several genes that provide neurotrophic support, while reducing that of pro-apoptotic genes and those encoding pro-inflammatory cytokines and their receptors. Ladostigil also decreased the expression of axonal growth inhibitors and those impairing mitochondrial function. Together, these actions could explain the protection by ladostigil against age-related memory decline.

Trait-related changes in brain network topology in premenstrual dysphoric disorder

The female predominance in the prevalence of depression is partially accounted by reactivity to hormonal fluctuations. Premenstrual dysphoric disorder (PMDD) is a reproductive subtype of depression characterized by cyclic emotional and somatic symptoms that recur before menstruation. Despite the growing understanding that most psychiatric disorders arise from dysfunctions in distributed brain circuits, the brain's functional connectome and its network properties of segregation and integration were not investigated in PMDD. To this end, we examined the brain's functional network organization in PMDD using graph theoretical analysis. 24 drug naïve women with PMDD and 27 controls without premenstrual symptoms underwent 2 resting-state fMRI scans, during the mid-follicular and late-luteal menstrual cycle phases. Functional connectivity MRI, graph theory metrics, and levels of sex hormones were computed during each menstrual phase. Altered network topology was found in PMDD across symptomatic and remitted stages in major graph metrics (characteristic path length, clustering coefficient, transitivity, local and global efficiency, centrality), indicating decreased functional network segregation and increased functional network integration. In addition, PMDD patients exhibited hypoconnectivity of the anterior temporal lobe and hyperconnectivity of the basal ganglia and thalamus, across menstrual phases. Furthermore, the relationship between difficulties in emotion regulation and PMDD was mediated by specific patterns of functional connectivity, including connections of the striatum, thalamus, and prefrontal cortex. The shifts in the functional connectome and its topology in PMDD may suggest trait vulnerability markers of the disorder.

A Novel Indoline Derivative Ameliorates Diabesity-Induced Chronic Kidney Disease by Reducing Metabolic Abnormalities

Both diabetes and obesity (diabesity) contribute significantly to the development of chronic kidney disease (CKD). In search of new remedies to reverse or arrest the progression of CKD, we examined the therapeutic potential of a novel compound, AN1284, in a mouse model of CKD induced by type 2 diabetes with obesity. Six-week-old BKS Cg-Dock 7^m+/+ Lepr^db/J mice with type 2 diabetes and obesity were treated with AN1284 (2.5 or 5 mg kg^-1 per day) via micro-osmotic pumps implanted subcutaneously for 3 months. Measures included renal, pancreatic, and liver assessment as well as energy utilization. AN1284 improved kidney function in BSK-db/db animals by reducing albumin and creatinine and preventing renal inflammation and morphological changes. The treatment was associated with weight loss, decreased body fat mass, increased utilization of body fat toward energy, preservation of insulin sensitivity and pancreatic β cell mass, and reduction of dyslipidemia, hepatic steatosis, and liver injury. This indoline derivative protected the kidney from the deleterious effects of hyperglycemia by ameliorating the metabolic abnormalities of diabetes. It could have therapeutic potential for preventing CKD in human subjects with diabesity.

Low-dose ladostigil for mild cognitive impairment: A phase 2 placebo-controlled clinical trial

OBJECTIVE

Ladostigil reduces oxidative stress and microglial activation in aging rats. We assessed its safety and potential efficacy in a 3-year, randomized, double-blind, placebo-controlled phase 2 clinical trial in patients with mild cognitive impairment (MCI) and medial temporal lobe atrophy.

METHODS

Patients 55 to 85 years of age with MCI, Clinical Dementia Rating (CDR) score of 0.5, Mini-Mental State Examination (MMSE) score >24, Wechsler Memory Scale-Revised Verbal Paired Associates I score ≤18, and Medial Temporal Lobe Atrophy Scale score >1 were stratified by APOE ε4 genotype and randomly assigned (1:1) to ladostigil 10 mg/d or placebo. Primary outcomes were safety and onset of Alzheimer disease dementia. Secondary endpoints were Neuropsychological Test Battery (NTB) composite, Disability Assessment in Dementia (DAD), and Geriatric Depression Scale (GDS) scores. Exploratory outcomes were NTB component, CDR, and MMSE scores. Biomarkers included MRI-derived whole-brain, hippocampus, and entorhinal cortex volumes.

RESULTS

Two hundred ten patients from 15 sites in Austria, Germany, and Israel were randomly allocated to placebo (107 patients) or ladostigil (103 patients). After 36 months, 21 of 103 patients on placebo and 14 of 99 patients receiving ladostigil progressed to Alzheimer disease (log-rank test p = 0.162). There were no significant effects on the NTB composite, DAD, or GDS score. Whole-brain and hippocampus volumes decreased more in the placebo than in the ladostigil group (whole brain, p = 0.025, Cohen d = 0.43; hippocampus, p = 0.043, d = 0.43). Serious adverse events were reported by 28 of 107 patients treated with placebo and 26 of 103 with ladostigil.

CONCLUSION

Ladostigil was safe and well tolerated but did not delay progression to dementia. Its association with reduced brain and hippocampus volume loss suggests a potential effect on atrophy.

CLINICALTRIALSGOV IDENTIFIER

NCT01429623.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with MCI and medial temporal lobe atrophy, ladostigil did not significantly decrease the risk of the development of Alzheimer disease.

Sex differences during emotion processing are dependent on the menstrual cycle phase

Sex differences in the neural processing of emotion are of special interest considering that mood and anxiety disorders predominant in females. However, these sex-related differences were typically studied without considering the hormonal status of female subjects, although emotion processing in the brain was shown to differ between phases of the menstrual cycle. In this functional MRI study, we demonstrated the influence of the menstrual cycle phase on sex differences in brain activity and functional connectivity during negative and positive emotions, using two different paradigms: emotion perception and emotion experience. Twenty naturally cycling healthy women without premenstrual symptoms were scanned twice: during the mid-follicular and late-luteal menstrual phases, and compared to a matched group of twenty healthy men. During negative emotion perception, men showed increased neural activity in the right hippocampal formation relative to women in the mid-follicular phase, and increased activity in the right cerebellum relative to women in the late-luteal phase. During experience of amusement, reduced putamen-ventrolateral prefrontal cortex and putamen-dorsomedial prefrontal cortex functional connectivity were observed for women in the late-luteal phase relative to men and associated with levels of sex hormones. These neural and hormonal findings were complemented by behavioral reports of reduced amusement and increased sadness in late-luteal women. Our results demonstrate menstrual phase-dependent sex differences in emotion perception and experience and may suggest a biological tendency for a deficient experience of pleasure and reward during the late-luteal phase. These findings may further shed light on the underlying pathophysiology of premenstrual dysphoric disorder.

Indoline derivatives mitigate liver damage in a mouse model of acute liver injury

BACKGROUND

Exposure of mice to D-galactosamine (GalN) and lipopolysaccharide (LPS) induces acute liver failure through elevation of TNF-α, which causes liver damage resembling that in humans. The current study evaluated in this model the effect of two indoline derivatives, which have anti-inflammatory activity in macrophages.

METHODS

AN1297 and AN1284 (0.025-0.75mg/kg) or dexamethasone (3mg/kg), were injected subcutaneously, 15min before intraperitoneal injection of GalN (800mg) plus LPS (50μg) in male Balb/C mice. After 6h, their livers were evaluated histologically by staining with hematoxylin and eosin for tissue damage and by cleaved caspase 3 for apoptosis. Activity of liver enzymes, alanine transaminase (ALT) and aspartate aminotransferase (AST) and levels of TNF-α and IL-6 were measured in plasma, and those of TNF-α and IL-6, in the liver.

RESULTS

AN1297 (0.075-0.75mg/kg) and AN1284 (0.25-0.75mg/kg) maximally reduced ALT by 51% and 80%, respectively. Only AN1284 (0.25 and 0.75mg/kg) reduced AST by 41% and 48%. AN1297 and AN1284 (0.25mg/kg) decreased activation of caspase 3 (a sign of apoptosis) by 80% and plasma TNF-α by 75%. AN1297 and AN1284 (0.075mg/kg) prevented the rise in TNF-α and IL-6 in the liver. AN1284 (0.25mg/kg) reduced mortality from 90% to 20% (p<0.01) and AN1297, to 60% (p=0.121). Both indoline derivatives inhibited the phosphorylation of MAPK p38 and DNA binding of the transcription factor, AP-1.

CONCLUSION

While both compounds are highly potent anti-inflammatory agents, AN1284 is more effective in mitigating the underlying causes of GalN/LPS-induced acute liver failure in mice.

Cholinergic Anti-Inflammatory Pathway Does Not Contribute to Prevention of Ulcerative Colitis by Novel Indoline Carbamates

Indoline carbamates, AN680 and AN917 decrease cytokines, TNF-α and IL-6 in peritoneal macrophages activated by lipopolysaccharide (LPS) and in mouse tissues after LPS injection. They prevent nuclear translocation of nuclear factor κB (NF-κB) and activator protein 1. Only AN917 inhibits cholinesterase (ChE) at relevant concentrations. ChE inhibitors decrease NF-κB by activating α7 nicotinic acetylcholine receptors (α7nAChR). The current study compared the effect of rivastigmine, a ChE inhibitor, AN680 and AN917 on ulcerative colitis induced in mice by ingestion of dextran sodium sulfate (4.5%) solution. Rivastigmine (1 mg/kg), AN680 (2.5-10 mg/kg) and AN917 (2-5 mg/kg) were injected subcutaneously once daily for 8 days. Disease severity was assessed by disease activity index (DAI), colonoscopy, colon length and body weight loss, colonic levels of TNF-α, IL-6, IL-1β and myeloid peroxidase (MPO) activity. AN680 (5 mg/kg) reduced DAI, colon shrinkage, weight loss, histopathological signs of colon damage, MPO activity, TNF-α, IL-1β and IL-6 levels without inhibiting ChE. AN917 (5 mg/kg) and rivastigmine (1 mg/kg) inhibited ChE in plasma and colon by 65%, reduced DAI, MPO activity and IL-6, but not TNF-α or IL-1β. AN917 did not prevent weight loss or colon shrinkage. Mecamylamine abolished the reduction of DAI, MPO activity and IL-6 by AN917 and rivastigmine, indicating they were mediated by α7nAChR.

CONCLUSIONS

AN680 is very effective in preventing DSS-induced UC in mice and may therefore have potential therapeutic application in humans. Addition of ChE inhibition and indirect activation of α7nAChR lessens the efficacy of AN917 in this model.

Sex-Specific Effects of Prenatal Stress on Memory and Markers of Neuronal Activity in Juvenile Rats

Stress during pregnancy can increase the incidence of emotional problems, learning and language difficulties in human infants and pre-adolescents. Most preclinical studies in rats that attempted to find experimental support for these observations were performed in adult male offspring, but the results are inconsistent. The aim of the current study was to examine the effect of prenatal stress on novel object recognition (NOR) and spatial learning and memory in the Morris water maze (MWM) of juvenile rats of both sexes. By the use of fluorescence immunohistochemistry and protein measurements by Western blot, we measured the expression of markers of neurogenesis (doublecortin, DCX) and neuronal activity that are important for synaptic plasticity and learning (c-fos, GluR1, nNOS). Since neuronal activity in the developing and adult brain can be regulated by astrocytes, we also measured the number of astrocytes and the expression of two astroglial proteins (GFAP and S100B) in the stress-responsive hippocampal dentate gyrus (DG). Experiments were performed on littermates of rats in which its effects on behavior were measured. We found for the first time that juvenile females performed better than males in the NOR and MWM tests. They also had higher densities of DCX and c-fos in the DG, together with the expression of nNOS and GluR1 in the subgranular zone (SGZ) of the DG. There were no sex differences in the expression of GFAP and S100B in astrocytes. Prenatal stress did not affect NOR in females, but improved it in males, together with an increase in DCX+ and c-fos, the number of GFAP-expressing astrocytes and the intensity of GFAP and S100B immunofluorescence in the DG. Staining intensity of GluR1 and nNOS in the hilus and SGZ of the DG, and protein expression in the whole DG, was unchanged in prenatally stressed males. Thus, prenatal stress changed the behavior and expression of key proteins in the DG to resemble that in females. A reduction in plasma testosterone, which although not attaining statistical significance was associated with that in anogenital distance, may contribute to the effect of prenatal stress in males. In females, prenatal stress had no effect on c-fos, DCX or the number of astrocytes but reduced the staining intensity of GluR1 and nNOS. Protein expression of nNOS was also significantly lower than that in prenatally stressed males. The differential effects of prenatal stress on hippocampal neuronal and glial markers may help to explain the sex-dependent effect on spatial learning in prepubertal rats.

Safety and clinical activity of vascular endothelial growth factor receptor (VEGFR)-tyrosine kinase inhibitors after programmed cell death 1 inhibitor treatment in patients with metastatic clear cell renal cell carcinoma

BACKGROUND

Emerging agents blocking the programmed cell death 1 (PD-1) pathway show activity in metastatic clear cell renal cell carcinoma (mRCC). The aim of this study was to evaluate the efficacy and safety of vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR)-tyrosine kinase inhibitor (TKI) therapy after PD-1 inhibition.

PATIENTS AND METHODS

Patients with mRCC treated with anti-PD-1 antibody (aPD-1) monotherapy or in combination (with VEGFR-TKI or ipilimumab) that subsequently received VEGFR-TKI were retrospectively reviewed. The efficacy end points were objective response rate (ORR) and progression-free survival (PFS) stratified by the type of prior PD-1 regimen. Safety by the type and PD-1 exposure was also evaluated.

RESULTS

Seventy patients were included. Forty-nine patients received prior therapy with immune checkpoint inhibitors (CPIs) alone and 21 had combination therapy of aPD-1 and VEGFR-TKI. Overall, ORR to VEGFR-TKI after PD-1 inhibition was 28% (19/68) and the median PFS was 6.4 months (mo) (4.3-9.5). ORR to VEGFR-TKI after aPD-1 in combination with VEGFR-TKI was lower than that in patients treated with VEGFR-TKI after CPI alone (ORR 10% versus 36%, P = 0.039). In the multivariable analysis, patients treated with prior CPI alone were more likely to achieve an objective response than those treated with aPD-1 in combination with VEGFR-TKI (OR = 5.38; 95% CI 1.12-26.0, P = 0.03). There was a trend toward numerically longer median PFS in the VEGFR-TKI after the CPI alone group, 8.4 mo (3.2-12.4) compared with 5.5 mo (2.9-8.3) for those who had VEGFR-TKI after aPD-1 in combination with VEGFR-TKI (P = 0.15). The most common adverse events (AEs) were asthenia, hypertension, and diarrhea.

CONCLUSIONS

The efficacy and safety of VEGFR-TKIs after PD-1 inhibition were demonstrated in this retrospective study. The response rate was lower and the median progression-free survival was shorter in those patients who received prior PD-1 in combination with VEGFR-TKI. PD-1 exposure does not seem to significantly influence the safety of subsequent VEGFR-TKI treatment.

Perinatal citalopram does not prevent the effect of prenatal stress on anxiety, depressive-like behaviour and serotonergic transmission in adult rat offspring

It is still not clear whether the selective serotonin reuptake inhibitors frequently prescribed to depressed pregnant women improve the behavioural outcome in their children. The current study investigated whether administration of citalopram to pregnant rats could prevent anxiety and depressive-like behaviour induced by gestational stress in their offspring, and restore the expression of serotonin 1A autoreceptors in GABAergic interneurons in the medial prefrontal cortex and dorsal raphe nuclei in males, and of corticotropin-releasing factor type 2 receptors in GABAergic interneurons in the dorsal raphe nuclei in females. Activation of these receptors modulates serotonergic transmission to target areas and is reduced in a sex-dependent manner by prenatal stress. Citalopram (10 mg/kg/day), administered orally from day 7 of gestation until 21 days postpartum, prevented the increase in anxiety in stressed mothers but did not reduce anxiety and depressive-like behaviour in their offspring and even induced depressive-like behaviour in the offspring of control mothers. Citalopram failed to restore the reduction in the expression of serotonin 1A autoreceptors in the prefrontal cortex of males and in corticotropin-releasing factor type 2 receptors in the dorsal raphe nuclei of females induced by prenatal stress. Prenatal citalopram did not prevent the behavioural changes or reduction in serotonergic transmission to target areas induced by prenatal stress. It had adverse behavioural effects in the offspring of control rats, which, together with the lack of any change in prenatally-stressed rats, may be due to inhibition of the foetal serotonin transporter thereby preventing normal development of the serotonin system.

Sex dependent reduction by prenatal stress of the expression of 5HT1A receptors in the prefrontal cortex and CRF type 2 receptors in the raphe nucleus in rats: reversal by citalopram

RATIONALE

Alterations in the serotonergic transmission and activity of corticotropin-releasing factor (CRF) family may underlie anxiety and depressive disorders. These could be corrected by treatment with SSRIs.

OBJECTIVES

The objective of the current study is to determine whether the increased anxiety of prenatally stressed (PS) rats of both sexes is associated with changes in 5HT1A and CRF type 2 receptors (5HT1AR and CRFR2) in the prefrontal cortex (PFC)-dorsal raphe nuclei (DRN) axis, and how these are affected by chronic treatment with citalopram (10 mg/kg/day). We focussed on GABAergic cells that co-express parvalbumin and/or neuropeptide Y, and 5HT1AR in the medial prefrontal cortex (mPFC) and on cells that express 5HT, parvalbumin, 5HT1AR or CRFR2 in the DRN.

RESULTS

Immunohistochemistry with fluorescent antibodies demonstrated sex differences in the expression of 5HT1AR and CRFR2 protein. Prenatal stress selectively reduced the expression of 5HT1AR on GABAergic cells in the mPFC in males and that of CRFR2 in the DRN of females. Citalopram treatment for 5 weeks abolished the increase in anxiety in both sexes, restored the intensity of expression of 5HT1AR in the mPFC in males and increased their expression in the mPFC and DRN in females. Citalopram reduced CRFR2 expression in control and PS males but increased it in PS females.

CONCLUSIONS

Male and female rats show differences in the expression of 5HT1AR and CRFR2 protein that are selectively reduced by prenatal stress. Reversal by citalopram of the changes in the expression of these receptors induced by prenatal stress support their role in the aetiology of anxiety.

Peripheral catecholamines mediate certain responses to central cholinergic receptor stimulation by oxotremorine

The role of peripheral catecholamines in mediating the pressor and tremorigenic effects of oxotremorine were investigated in conscious rats. At time of peak tremor intensity induced by oxotremorine, plasma adrenaline and noradrenaline were increased 3--4-fold. Tremor intensity was substantially reduced by either adrenal medullectomy, chemical sympathectomy with 6-hydroxydopamine, or injection of 2.5 mg/kg L-propranolol. The pressor response to oxotremorine was not reduced by adrenal denervation, which however prevented the usual rise in plasma adrenaline but not that of noradrenaline. It is concluded that central cholinergic receptor stimulation activates the sympatho-adrenal system. While both adrenaline and intact sympathetic nerves are necessary for the mediation of the full tremorigenic effect, the pressor response to oxotremorine is mainly due to the effect of noradrenaline on vascular alpha-receptors.

Dose-limiting inhibition of acetylcholinesterase by ladostigil results from the rapid formation and fast hydrolysis of the drug-enzyme complex formed by its major metabolite, R-MCPAI

Ladostigil is a pseudo reversible inhibitor of acetylcholinesterase (AChE) that differs from other carbamates in that the maximal enzyme inhibition obtainable does not exceed 50-55%. This could explain the low incidence of cholinergic adverse effects induced by ladostigil in rats and human subjects. The major metabolite, R-MCPAI is believed to be responsible for AChE inhibition by ladostigil in vivo. Therefore we determined whether the ceiling in AChE inhibition resulted from a limit in the metabolism of ladostigil to R-MCPAI by liver microsomal enzymes, or from the kinetics of enzyme inhibition by R-MCPAI. Ladostigil reduces TNF-α in lipopolysaccharide-activated microglia. In vivo, it may also reduce pro-inflammatory cytokines by inhibiting AChE and increasing the action of ACh on macrophages and splenic lymphocytes. We also assessed the contribution of AChE inhibition in the spleen of LPS-injected mice to the anti-inflammatory effect of ladostigil. As in other species, AChE inhibition by ladostigil in spleen, brain and plasma did not exceed 50-55%. Since levels of R-MCPAI increased with increasing doses of ladostigil we concluded that there was no dose or rate limitation of metabolism. The kinetics of enzyme inhibition by R-MCPAI are characterized by a rapid formation of the drug-enzyme complex and fast hydrolysis which limits the attainable degree of AChE inhibition. Ladostigil and its metabolites (1-100 nM) decreased TNF-α in lipopolysaccharide-activated macrophages. Ladostigil (5 and 10mg/kg) also reduced TNF-α in the spleen after injection of lipopolysaccharide in mice. However, AChE inhibition contributed to the anti-inflammatory effect only at a dose of 10mg/kg.

Indoline-3-propionate and 3-aminopropyl carbamates reduce lung injury and pro-inflammatory cytokines induced in mice by LPS

BACKGROUND AND PURPOSE

In the search for safer and effective anti-inflammatory agents, we investigated the effect of methyl indoline-3-propionate and indoline-3-(3-aminopropyl) carbamates on LPS-induced lung injury and pro-inflammatory cytokines in mice. Their mechanism of action was determined in murine peritoneal macrophages.

EXPERIMENTAL APPROACH

Lung injury was induced by intratracheal infusion of LPS and assessed by the change in lung weight and structure by light microscopy after staining by haematoxylin and eosin. In LPS-activated macrophages, MAPK proteins and IκBα were measured by Western blotting and the transcription factors, AP-1 and NF-κB by electromobility shift assay. Cytokines in the plasma and spleen of mice injected with LPS were measured by elisa-based assay.

KEY RESULTS

AN917 and AN680 (1-10 pM) decreased TNF-α protein in macrophages by inhibiting phosphorylation of p38 MAPK, IκBα degradation and activation of AP-1 and NF-κB without affecting cell viability. In vivo, these compounds (10 μmol · kg(-1)) markedly decreased lung injury induced by LPS and the elevation of TNF-α and IL-6 in lung, plasma and spleen. Activation of α-7nACh receptors contributed to the reduction of TNF-α by AN917, which inhibited AChE in the spleen by 35%.

CONCLUSION AND IMPLICATIONS

Indoline carbamates are potent inhibitors of pro-inflammatory mediators in murine macrophages and in mice injected with LPS, acting via the p38 MAPK, AP-1 and NF-κB cascades. Indirect α-7nACh receptor activation by AN917, through inhibition of AChE, contributes to its anti-inflammatory effect. Indoline carbamates may have therapeutic potential for lung injury and other diseases associated with chronic inflammation without causing immunosuppression.

Functional connectivity in prenatally stressed rats with and without maternal treatment with ladostigil, a brain-selective monoamine oxidase inhibitor

Stress during pregnancy in humans is known to be a risk factor for neuropsychiatric disorders in the offspring. Prenatal stress in rats caused depressive-like behavior that was restored to that of controls by maternal treatment with ladostigil (8.5 mg/kg per day), a brain-selective monoamine oxidase (MAO) inhibitor that prevented increased anxiety-like behavior in stressed mothers. Ladostigil inhibited maternal striatal MAO-A and -B by 45-50% at the time the pups were weaned. Using resting state-functional connectivity magnetic resonance imaging on rat male offspring of control mothers, and mothers stressed during gestation with and without ladostigil treatment, we identified neuronal connections that differed between these groups. The percentage of significant connections within a predefined predominantly limbic network in control rats was 23.3 within the right and 22.0 within the left hemisphere. Prenatal stress disturbed hemispheric symmetry, resulting in 30.2 and 21.6%, significant connections in the right and left hemispheres, respectively, but this was fully restored in the maternal ladostigil group to 24.6% in both hemispheres. All connections that were modified in prenatally stressed rats and restored by maternal drug treatment were associated with the dopaminergic system. Specifically, we observed that restoration of the connections of the right nucleus accumbens shell with frontal areas, the cingulate, septum and motor and sensory cortices, and those of the right globus pallidus with the infra-limbic and the dentate gyrus, were most important for prevention of depressive-like behavior.

Dose-dependent effects of ladostigil on microglial activation and cognition in aged rats

The current study determined the effects of chronic treatment of aging rats with ladostigil, a cholinesterase (ChE) and monoamine oxidase (MAO) inhibitor, at doses of 1 and 8.5 mg/kg/day, on novel object recognition (NOR) and reference memory in the Morris water maze (MWM). A dose of (1 mg/kg/day) did not inhibit ChE or MAO but prevented the loss of NOR and reference memory in the MWM that occurs at 20.5 months of age. This anti-aging effect was associated with a reduction in the expression of CD11b, a marker of microglial activation, in the fornix and parietal cortex and restoration of microglial morphology to that in young adult rats. Ladostigil (8.5 mg/kg/day) inhibited brain ChE by ≈30 % and MAO A and B by 55-59 %, and had a similar, or greater effect than the low dose on microglia, but was less effective in preventing the decline in NOR. Ladostigil (8.5 mg/kg/day) may have caused too much cortical ChE inhibition and acetylcholine elevation at 16 months when NOR was intact. In support of this suggestion we showed that acute administration of ladostigil (8.5 mg/kg) worsened NOR at this age. However, at 20 months, when NOR was impaired and brain acetylcholine levels are 40 % below normal, ladostigil (8.5 mg/kg) reversed the memory deficit.

CONCLUSION

Ladostigil (1 mg/kg/day) prevents the development of age-related memory deficits by a combination of immunomodulatory and antioxidant effects. A dose causing 30 % ChE inhibition is necessary in order to reverse existing memory deficits at 20 months of age.

Anti-inflammatory effects of ladostigil and its metabolites in aged rat brain and in microglial cells

Impaired mitochondrial function accompanied by microglial activation and the release of nitric oxide (NO) and pro-inflammatory cytokines has been reported in Alzheimer's disease, its prodromal phase of Mild Cognitive Impairment (MCI) and in aged rats. The present study showed that 6 months treatment of 16 month old rats with ladostigil (1 mg/kg/day), a novel drug designed for the treatment of MCI, prevented the development of spatial memory deficits at 22 months of age and significantly decreased the gene expression of IL-1β, IL-6, TNF-α and inducible nitric oxide synthase (iNOS) in the parietal cortex. It was also shown that concentrations ranging from 1nM-1 μM of ladostigil and three of its active metabolites inhibited the release of nitric oxide (NO) induced by lipopolysaccharide (LPS) from mouse microglial cells by up to 35-40 %. Ladostigil and its metabolites (10nM) also reduced TNF-α mRNA and protein by 25-35 % and IL-1β and inducible nitric oxide synthase (iNOS) mRNA by 20-35 %. The concentration of 10nM is in the range of that of the parent drug, R-MCPAI and R-HPAI found in plasma after oral administration of ladostigil (1 mg/kg/day) to rats. All the compounds inhibited the degradation of IkB-α and nuclear translocation of the p65 subunit of NF-kB. They also inhibited phosphorylation of p38 and ERK1/2 mitogen-activated protein kinase (MAPK), but had no effect on that of JNK. We propose that the anti-inflammatory activity may contribute towards the neuroprotective action of ladostigil against the development of memory impairments induced by aging or toxin-induced microglial activation.

Sex-dependent changes induced by prenatal stress in cortical and hippocampal morphology and behaviour in rats: an update

Recent prospective studies have shown that gestational stress in humans is more likely to cause cognitive and emotional problems in the offspring if it occurs during weeks 12-20 of pregnancy. There are also suggestions that such problems may be gender dependent. This review describes recent studies that found sex differences in the behaviour and brain morphology of rats stressed prenatally during the equivalent period of neuronal development in humans. Learning deficits are more prevalent in males and anxious behaviour in females but their appearance depends also on the timing and intensity of the stress and the age when the offspring were tested. Cognitive deficits and anxiety are linked to a sex-dependent reduction in neurogenesis and in measures of dendritic morphology in the prefrontal cortex and hippocampal formation. Maternal adrenalectomy prior to the stress prevents the anxiety in both sexes and learning deficits in males. Corticosterone administration to the dam to mimic levels induced by stress reinstates only the anxiety, indicating that it arises from foetal exposure to corticosterone from the maternal circulation. Learning deficits in males may result from a combination of a reduction in testosterone and in aromatase activity, together with the action of other adrenal hormones.

Differential effect of prenatal stress on the expression of corticotrophin-releasing hormone and its receptors in the hypothalamus and amygdala in male and female rats

The present study examined the effect of prenatal stress in rats from days 13-20 of gestation on anxiogenic behaviour in the elevated plus maze (EPM) together with changes in the gene expression of corticotrophin-releasing hormone (CRH), its receptors, CRHR1 and CRHR2, as well as CRH binding protein (CRH-BP) in the paraventricular nucleus (PVN) and amygdala of their male and female offspring. Both prenatally-stressed (PS) males and females showed heightened anxiety in the EPM. Prenatal stress did not alter the gene expression of CRH or its receptors in the male PVN, although it decreased CRH-BP mRNA, which could augment the activity of free CRH. In the PVN of PS females, there was an increase in the expression of CRH, coupled with a decrease in that of CRHR2 and CRH-BP. These changes are compatible with the greater activation of the hypothalamic pituitary adrenal axis to stress in females. Anxiogenic behaviour of PS rats was associated with a reduction of CRHR2 mRNA and of CRH-BP mRNA in the amygdala of males and an increase in CRH mRNA and decrease in CRHR2 mRNA in females. Two hours after acute stress of exposure to the elevated plus maze in which heightened anxiety was manifested, increases were seen only in the amygdala of females in CRH and CRHR1 signalling, whereas CRHR2 mRNA was reduced in both sexes. The data show that both prenatal stress and acute stress in adulthood have a differential sex-dependent effect on the expression of CRH its receptors and binding protein in the PVN and amygdala of rats.

Corticosterone mediates some but not other behavioural changes induced by prenatal stress in rats

The effect of daily varied stress from days 13-21 of gestation in Wistar rats was investigated by tests of learning and memory and anxiogenic behaviour in the 60-day-old offspring of both sexes. Prenatal stress decreased the anogenital distance in males at 1 day of age. Anxiogenic behaviour in the elevated plus maze was seen in prenatally-stressed rats of both genders. There was no significant gender difference in the rate of spatial learning in the Morris water maze but prenatal stress only slowed that of males. In the object recognition test with an inter-trial interval of 40 min, females but not males, discriminated between a familiar and novel object. Prenatal stress did not affect object discrimination in females but feminised that in males. Maternal adrenalectomy with replacement of basal corticosterone levels in the drinking fluid prevented all of the above effects of prenatal stress in the offspring. To mimic the peak corticosterone levels and time course of elevation in response to stress, corticosterone (3 mg/kg) was injected twice (0 and 30 min) on days 13-16 and once on days 17-20 of gestation to adrenalectomised mothers. This treatment re-instated anxiogenic behaviour similar to that induced by prenatal stress, indicating that it is mediated by exposure of the foetal brain to raised levels of corticosterone. However, steroid administration to adrenalectomised dams did not decrease anogenital distance, feminise object recognition memory or slow spatial learning in their male offspring. The findings indicate that other adrenal hormones are necessary to induce these effects of prenatal stress.

Prenatal stress diminishes gender differences in behavior and in expression of hippocampal synaptic genes and proteins in rats

The study determined whether there were gender differences in the expression of hippocampal genes in adult rats in association with dissimilarity in their behavior, and how these were affected by prenatal stress. Pregnant Wistar rats were subjected to varied stress once daily on days 14-20 of gestation. Adult female offspring of control rats showed significantly less anxiogenic behavior in the elevated plus maze and better discrimination between a novel and familiar object than males in the object recognition test. These gender differences in behavior were markedly attenuated by prenatal stress. Using Affymetrix DNA chip technology on hippocampal extracts prepared from littermates of the offspring used for behavioral tests, we found that 1,680 genes were differentially expressed in control males and females. The gender difference in gene expression was decreased to 11% (191 genes) by prenatal stress. In both sexes, processes like the translational machinery, mitochondrial activity, and cation transport were downregulated compared to controls, but there was a greater suppression of genes involved in vesicle trafficking, regulation of synaptic plasticity, and neurogenesis in females than in males. This was compensated by a higher expression of other components of vesicle trafficking, microtubule-based processes, and neurite development. Prenatal stress decreased the expression of 19 Rab proteins in females and five Rabs in males, but a compensatory increase of Rab partner proteins and effectors only occurred in females. Exposure to stress decreased the expression of synaptic proteins, synaptophysin, and synaptopodin in prenatally stressed males and females and increased those of PSD-95 and NR1 subunit of the N-methyl-D-aspartic acid (NMDA) glutamate receptor only in females. The study provides an unbiased view of key genes and proteins that act as gender dependent molecular sensors. The disruption of their expression by adverse early life stress may explain the alterations that occur in behavior.

Intrauterine factors as determinants of depressive disorder

Although the etiology of major depressive disorder (MDD) is unknown, it is precipitated in susceptible individuals by adverse events. This review examines the role of intrauterine factors resulting from exposure to stress hormones in the increased vulnerability of the organism to MDD. Severe maternal stress or alcohol intake during the second and third trimesters causes excess release of corticotropin releasing hormone (CRH) and cortisol. These hormones reduce birth weight; impair the feedback regulation of the hypothalamic pituitary adrenal axis (HPA) axis and 5-HT1A and 5-HT2A signaling in key brain areas. Similar changes are seen in patients with MDD and in experimental animals after chronic inescapable stress, prenatal stress or alcohol, which also induce depressive-like behavior in rats, alterations in sleep and circadian rhythms reminiscent of those in humans with MDD. Clinical improvement of MDD by antidepressants is accompanied by normalization of the regulation of the HPA axis and of serotoninergic transmission.

Ladostigil prevents age-related glial activation and spatial memory deficits in rats

Oxidative stress and glial activation occur in the aging brain. Ladostigil is a new monoamine oxidase (MAO) and acetylcholinesterase (AChE) inhibitor designed for the treatment of Alzheimer's disease. It has neuroprotective and antioxidant activities in cellular models at much lower concentrations than those inhibiting MAO or AChE. When ladostigil (1mg/kg/day) was given for 6 months to 16-month-old rats it prevented the age-related increase in activated astrocytes and microglia in several hippocampal and white matter regions and increased proNGF immunoreactivity in the hippocampus towards the levels in young rats. Ladostigil also prevented the age-related reduction in cortical AChE activity and the increase in butyrylcholinesterase activity in the hippocampus, in association with the reduction in gliosis. The immunological and enzymatic changes in aged rats were associated with improved spatial memory. Ladostigil treatment had no effect on memory, glial or proNGF immunoreactivity in young rats. Early treatment with ladostigil could slow disease progression in conditions like Alzheimer's disease in which oxidative stress and inflammatory processes are present.

The long-term behavioural consequences of prenatal stress

Maternal distress during pregnancy increases plasma levels of cortisol and corticotrophin releasing hormone in the mother and foetus. These may contribute to insulin resistance and behaviour disorders in their offspring that include attention and learning deficits, generalized anxiety and depression. The changes in behaviour, with or independent of alterations in the function of the hypothalamic pituitary adrenal (HPA) axis, can be induced by prenatal stress in laboratory rodents and non-human primates. The appearance of such changes depends on the timing of the maternal stress, its intensity and duration, gender of the offspring and is associated with structural changes in the hippocampus, frontal cortex, amygdala and nucleus accumbens. The dysregulation of the HPA axis and behaviour changes can be prevented by maternal adrenalectomy. However, only the increased anxiety and alterations in HPA axis are re-instated by maternal injection of corticosterone.

CONCLUSION

Excess circulating maternal stress hormones alter the programming of foetal neurons, and together with genetic factors, the postnatal environment and quality of maternal attention, determine the behaviour of the offspring.

Chronic brain cytochrome oxidase inhibition selectively alters hippocampal cholinergic innervation and impairs memory: Prevention by ladostigil

A 25-35% reduction of brain cytochrome oxidase (COx) activity found in Alzheimer's disease (AD) could contribute to neuronal dysfunction and cognitive impairment. The present study replicated the reduction in brain COx activity in rats by administering sodium azide (NaN(3)) for 4 weeks via Alzet minipumps at the rate of 1 mg/kg/h, and determined its effect on hippocampal cholinergic transmission, spatial and episodic memory. NaN(3) caused a selective reduction in choline acetyltransferase (ChAT) immunoreactivity in the diagonal band, a major source of cholinergic input to the hippocampus and cingulate cortex, without altering the number of cholinergic neurons. NaN(3) also induced a significant increase in vesicular acetylcholine transporter (VAChT)-immunoreactive varicosities, GAP-43 in the subgranular layer and of transferrin receptors (TfR) in the hilus of the dentate gyrus. These neurochemical changes were associated with impairment in spatial learning in the Morris water maze and in episodic memory in the object recognition test. Chronic treatment with ladostigil, a novel cholinesterase and monoamine oxidase inhibitor, prevented the decrease in ChAT in the diagonal band, the compensatory increase in synaptic plasticity and TfR and the memory deficits without restoring COx activity. Ladostigil had no significant effect on ChAT activity, synaptic plasticity or TfR in control rats. Ladostigil may have a beneficial effect on cognitive deficits in AD patients that have a reduction in cortical COx activity and cholinergic hypofunction.

Gender differences in the effects of prenatal stress on brain development and behaviour

An increased incidence of anxiety, depression and attention deficits in children has been linked to psychological stress during pregnancy. Subjection of a pregnant rat to stress at a time when the foetal limbic and hypothalamic pituitary adrenal (HPA) axes develop results in anxiogenic and depressive behaviour and learning and attention deficits in the offspring, which depend on its gender, intensity and timing of the maternal stress and behaviour being tested. Maternal stress increases corticosterone levels in the foetal brain, decreases foetal testosterone and brain aromatase activity in males, and alters brain catecholamine activity to that in females. Learning deficits, reductions in hippocampal neurogenesis, LTP and dendritic spine density in the prefrontal cortex are more readily seen in prenatally-stressed males, while anxiety, depression and increased response of the HPA axis to stress are more prevalent in females. Genders may differ in the sensitivity of developing brain areas to stress hormones.