A concerted neuron-astrocyte program declines in ageing and schizophrenia

Human brains vary across people and over time; such variation is not yet understood in cellular terms. Here we describe a relationship between people's cortical neurons and cortical astrocytes. We used single-nucleus RNA sequencing to analyse the prefrontal cortex of 191 human donors aged 22-97 years, including healthy individuals and people with schizophrenia. Latent-factor analysis of these data revealed that, in people whose cortical neurons more strongly expressed genes encoding synaptic components, cortical astrocytes more strongly expressed distinct genes with synaptic functions and genes for synthesizing cholesterol, an astrocyte-supplied component of synaptic membranes. We call this relationship the synaptic neuron and astrocyte program (SNAP). In schizophrenia and ageing-two conditions that involve declines in cognitive flexibility and plasticity1,2-cells divested from SNAP: astrocytes, glutamatergic (excitatory) neurons and GABAergic (inhibitory) neurons all showed reduced SNAP expression to corresponding degrees. The distinct astrocytic and neuronal components of SNAP both involved genes in which genetic risk factors for schizophrenia were strongly concentrated. SNAP, which varies quantitatively even among healthy people of similar age, may underlie many aspects of normal human interindividual differences and may be an important point of convergence for multiple kinds of pathophysiology.

Concerted neuron-astrocyte gene expression declines in aging and schizophrenia

Human brains vary across people and over time; such variation is not yet understood in cellular terms. Here we describe a striking relationship between people's cortical neurons and cortical astrocytes. We used single-nucleus RNA-seq to analyze the prefrontal cortex of 191 human donors ages 22-97 years, including healthy individuals and persons with schizophrenia. Latent-factor analysis of these data revealed that in persons whose cortical neurons more strongly expressed genes for synaptic components, cortical astrocytes more strongly expressed distinct genes with synaptic functions and genes for synthesizing cholesterol, an astrocyte-supplied component of synaptic membranes. We call this relationship the Synaptic Neuron-and-Astrocyte Program (SNAP). In schizophrenia and aging - two conditions that involve declines in cognitive flexibility and plasticity 1,2 - cells had divested from SNAP: astrocytes, glutamatergic (excitatory) neurons, and GABAergic (inhibitory) neurons all reduced SNAP expression to corresponding degrees. The distinct astrocytic and neuronal components of SNAP both involved genes in which genetic risk factors for schizophrenia were strongly concentrated. SNAP, which varies quantitatively even among healthy persons of similar age, may underlie many aspects of normal human interindividual differences and be an important point of convergence for multiple kinds of pathophysiology.

MRI estimated changes in visceral adipose tissue and liver fat fraction in patients with obesity during a very low-calorie-ketogenic diet compared to a standard low-calorie diet

AIM

To compare the changes in visceral adipose tissue (VAT), liver fat fraction, and liver stiffness using quantitative magnetic resonance imaging (MRI) during a very-low-calorie ketogenic (VLCK) diet and a standard low-calorie diet (LC).

MATERIALS AND METHODS

The study involved secondary analysis of prospective collected clinical data. Patients undergoing weight loss interventions were randomised to either a LC or a VLCK diet. VAT, liver fat fraction, and stiffness were measured at baseline and after 2 months.

RESULTS

Forty-six patients were included; 39 patients were evaluated at baseline and at 2 months follow-up. Mean weight loss was -9.7±3.8 kg (interquartile range [IQR]: -12.3; -7 kg) in the VLCK group and -1.67±2.2 kg (IQR: -3.3, -0.1 kg) in the LC group (p<0.0001). Mean VAT reductions were -39.3±40 cm² (IQR: -52, -10 cm²) and -12.5±38.3 cm² (IQR: -29, 5 cm²; p=0.0398), and mean liver proton density fat fraction (PDFF) reductions were -4.77±4.2% (IQR: -7.3, -1.7%) and -0.79±1.7%, (IQR: -1.8, -0.4%; p<0.005) in the VLCK group and in the LC group, respectively. No significant changes in liver stiffness occurred from baseline to follow-up.

CONCLUSION

A VLCK diet resulted in greater weight loss than a standard low-calorie diet and in significantly greater reduction in liver PDFF. As anthropometric measurements may not correlate with liver fat changes, it may be advantageous to include quantitative MRI to the monitoring strategies of patients undergoing weight-loss programmes.

Timescales of water accumulation in magmas and implications for short warning times of explosive eruptions

Water plays a key role in magma genesis, differentiation, ascent and, finally, eruption. Despite the recognized crucial function of water, there are still several issues that continue to blur our view about its role in magmatic systems. What are the timescales of H₂O accumulation in crystallizing magmas? What are the ascent rates of water-rich residual melts leading to explosive eruptions? Here, we track the timescale of water accumulation in a residual melt resulting from crystallization of a hydrous CO₂-bearing magmatic mass stored at mid- to deep-crustal levels in a subduction-related geodynamic setting. Our results indicate that, after a repose period ranging from few to several thousand years, water-rich melts with water concentrations larger than 6–9 wt.% can migrate towards the Earth surface in very short timescales, on the order of days or even hours, possibly triggering explosive eruptions with short warning times and devoid of long-term geophysical precursors.

Volatiles such as water play a key role in magma ascent and ultimately triggering explosive eruptions. Here, the authors show that water-rich melts with water concentrations of 6–9 wt.% can ascend rapidly to the surface over the timescales of hours to days with very short warning times.

Atypical esophageal vascular lesions observed in liver cirrhosis

Chronic liver disease is known to be associated with several vascular alterations including portal hypertension and hepato-pulmonary insufficiency. We report a case of esophageal vascular lesions resembling spider naevi in a patient with nonalcoholic cirrhosis who underwent an upper gastrointestinal (GI) endoscopy. We observed the presence of multiple white round elevations, 5-6 mm in size, with radiating thin-walled vessels, in the middle and distal esophagus. The histological examination documented the presence of multiple dilated blood vessels in the mucosal layer of the esophagus, with striking thickening of the endothelium wall. There was no evidence of esophagogastric varices, but only of a moderate congestive antral gastropathy. To our knowledge, these endoscopic esophageal findings have not yet been described in cirrhosis.

The use of thiopurines for the treatment of inflammatory bowel diseases in clinical practice

BACKGROUND

Thiopurines are the most commonly used immunomodulatory drugs in inflammatory bowel diseases.

AIM

To evaluate the use, the therapeutic and safety profiles of thiopurines in a large sample of IBD patients.

METHODS

We reviewed 3641 case histories of IBD patients. Thiopurines were prescribed in 582 patients (16.0%); the analysis was performed on the 553 (267 ulcerative colitis, 286 Crohn's disease) with exhaustive clinical data.

RESULTS

The main indications for treatment were steroid-dependence (328/553, 59.3%) and steroid-resistance (113/553, 20.7%). Thiopurines were started when CD were younger than UC patients (p<0.001) but earlier from diagnosis in UC than in CD patients (p=0.003). Efficacy was defined as optimal (258/553, 46.6%), partial (108/553, 19.5%), absent (85/553, 15.4%) and not assessable (102/553, 18.4%). Efficacy was independent of disease type, location/extension or duration and age at starting. Side effects were observed in 151/553 (27.3%) patients, leading to drug discontinuation in 101 (18.3%). 15 out of the 130 (11.5%) patients who took thiopurines for more than 4 years relapsed, more frequently in CD than in UC (OR=3.67 95% C.I. 0.98-13.69; p=0.053).

CONCLUSIONS

Thiopurines confirm their clinical usefulness and acceptable safety profile in managing complicated IBD patients. The majority of patients treated for longer than 4 years maintain response. No clinical and demographic predictive factors for efficacy and side effects were identified.

Oral, colonic-release low-molecular-weight heparin: an initial open study of Parnaparin-MMX for the treatment of mild-to-moderate left-sided ulcerative colitis

BACKGROUND

Efficacy of heparin and low-molecular-weight heparins (LMWHs) in inflammatory bowel disease (IBD) treatment has been suggested. The multimatrix oral formulation MMX releases active drugs in the colon, avoiding systemic absorption. Parnaparin sodium is the LMWH chosen to be carried in the MMX formulation.

AIM

To assess the safety of three different oral dosages (70, 140 and 210 mg once daily) of Parnaparin-MMX (CB-01-05) in left-sided ulcerative colitis (UC).

METHODS

Left-sided UC patients, with a mild-to-moderate relapse were enrolled. All patients received Parnaparin-MMX for 8 weeks. Clinical Activity Index (CAI), Disease Activity Index (DAI), Endoscopic Activity Index and IBD-QoL were assessed throughout the study. A strict clinical and laboratory follow-up, including assessment of anti-factor Xa activity, was performed. Clinical remission was defined as CAI <4.

RESULTS

Ten UC patients were enrolled. One patient retired for clinical deterioration. No relevant side effects, including either interference with haemostasis parameters or increased bleeding, were observed. At the end of the treatment, seven patients (70%) were in clinical remission, only one achieving endoscopic healing. Mean final CAI, DAI and IBD-QoL scores were significantly improved from baseline.

CONCLUSIONS

Parnaparin-MMX appears to be a safe treatment option in mild-to-moderate UC. Controlled studies are warranted.

Carriage of CARD15 variants and smoking as risk factors for resective surgery in patients with Crohn's ileal disease

BACKGROUND

It is controversial whether CARD15 variants are truly associated with a more severe form of Crohn's disease. The relative role of CARD15 genotype and smoking in Crohn's disease progression is also debated.

AIM

To investigate the association between CARD15 variants and history of resective surgery in patients with Crohn's ileal disease, taking into account smoking as a possible confounding factor.

METHODS

We originally assessed CARD15 genotype in 239 north Italian Crohn's disease patients (mean follow-up: 10.1 +/- 8.1 years). We then focused on 193 patients with proven ileal involvement, 70 of whom (36.3%) carried CARD15-mutated alleles (G908R, R702W, L1007fs).

RESULTS

Carriage of CARD15 variants was positively associated with family history and ileal-only disease and negatively associated with uncomplicated behaviour at maximal follow-up (P < 0.05). Ileal resection was the only variable independently associated with CARD15 variants at multivariate analysis (OR 3.8; 95% CI 1.6-9.2; P = 0.003). Kaplan-Meier analysis showed that ileal resection was favoured both by CARD15 variant-carriage (P = 0.01) and by smoking (P = 0.05), but smoking did not affect progression to surgery in variant carriers (P = 0.31). Thirteen of 14 (93%) patients being resection-free at 15-year follow-up, had CARD15 wild-type genotype (P = 0.01), whereas only seven (50%) had never smoked (P = 1.0).

CONCLUSIONS

In summary, CARD15 variant-associated Crohn's ileitis is virtually committed to stricturing and/or penetrating disease and, eventually, to resective surgery. Smoking accelerates progression to surgery in patients with wild-type CARD15 genotype, but it seems to exert no additional effect in CARD15-variant carriers.

Assessment of thrombin-activatable fibrinolysis inhibitor (TAFI) plasma levels in inflammatory bowel diseases

OBJECTIVES

Hypofibrinolysis has been proposed as a possible mechanism underlying the known risk of thrombosis observed in patients with inflammatory bowel diseases (IBD). Thrombin-activatable fibrinolysis inhibitor (TAFI) is a recently described inhibitor of fibrinolysis. Increased TAFI plasma levels are associated with a risk for venous thrombosis. The objective was to evaluate TAFI plasma levels and their possible correlations with clinical features and acute-phase reactants in IBD patients.

METHODS

Eighty-one IBD patients (47 Crohn's disease and 34 ulcerative colitis) and 81 sex- and age-matched healthy controls were enrolled in the study; moreover, we studied 30 inflammatory controls (13 Reiter's syndrome, 4 Behçet's syndrome, and 13 patients with newly diagnosed celiac disease). TAFI plasma levels were assessed by means of a commercially available ELISA kit. Erythrocytes sedimentation rate, C-reactive protein, and alpha1-acid glycoprotein were measured as acute-phase reactants. Statistical analysis was performed by means of nonparametric tests and Fisher's exact test and chi(2) test for independence.

RESULTS

Median TAFI plasma levels were significantly higher in IBD patients (116.0%, range: 39.0-232.0%) and in inflammatory controls (176.0%, 50.0-435.0%) than in healthy controls (99.0%, 40.0-170.0%) (p< or = 0.05 and p< or = 0.001, respectively). TAFI plasma levels higher than the 95th percentile of control values were significantly more frequent in IBD patients (19.7%) and in inflammatory controls (53.3%) than in healthy controls (4.9%) (p< or = 0.008 and p< or = 0.0001, respectively) and more frequent in clinically active IBD than in clinically quiescent IBD (31.4%vs 10.9%, p< or = 0.03). Finally, in IBD, significant correlations were observed between TAFI plasma levels and erythrocytes sedimentation rate (p< or = 0.02), C-reactive protein (p< or = 0.001), and alpha1-acid glycoprotein (p< or = 0.05).

CONCLUSIONS

TAFI plasma levels are increased in IBD patients and correlate with acute-phase reactants. Increased TAFI plasma levels might contribute to the prothrombotic state observed in IBD through the induction of hypofibrinolysis.

Exploring the relationships between inflammatory response and coagulation cascade in inflammatory bowel disease

BACKGROUND

The inflammatory network and the coagulation cascade are strictly correlated biological systems. Inflammatory Bowel Diseases (IBD) are characterised by a prothrombotic state, a hypercoagulability state and an increased prevalence of thromboembolic events.

METHODS

We reviewed the IBD literature in which the relationships between inflammation and coagulation were evaluated.

RESULTS

Several risk factors and mechanisms have been suggested to be implicated in determining the increased risk for thrombosis of IBD. Even if IBD may be per se a prothrombotic condition, systemic inflammation and vitamin deficiencies appear to play a relevant role in determining such a risk.

CONCLUSIONS

A good and continuous control of the intestinal disease and vitamin supplementation are strongly recommended in order to correct some of the risk factors for thrombosis in IBD patients.

Dopamine-dependent behavioural stimulation by non-peptide delta opioids BW373U86 and SNC 80: 1. Locomotion, rearing and stereotypies in intact rats

The unconditioned behavioural effects of two non-peptide delta-opioid receptor agonists, BW 373U86 and SNC 80, were studied in the intact rat. BW 373U86 (0.1-2.5 mg/kg s.c.) and SNC 80 (2.5-10 mg/kg s.c.) dose-dependently elicited locomotion, rearing, stereotyped sniffing, licking and gnawing. These effects were abolished by pretreatment with the delta-opioid receptor antagonist naltrindole (5.0 mg/kg s.c.). In view of the phenomenological similarities between this syndrome and that elicited by dopamine-receptor agonists, the role played by dopamine receptors was investigated. The specific dopamine D1 receptor antagonist SCH 23390 and the specific dopamine D2/D3 receptor antagonist raclopride reduced or even abolished the behavioural stimulation induced by lower doses of BW 373U86 and SNC 80. When higher doses of BW 373U86 were used (2.5 mg/kg), however, raclopride, even at high cataleptic doses (6.0 mg/kg), only partly prevented the behavioural stimulation induced by the delta-opioid receptor agonist. The behavioural stimulation remaining after high doses of raclopride was abolished by the administration of SCH 23390. These results show that delta-opioid receptor stimulation elicits dopamine-dependent behavioural activation in the rat that depends on dopamine receptors, particularly of the D1 subtype.

Dopamine-dependent behavioural stimulation by non-peptide delta opioids BW373U86 and SNC 80: 2. Place-preference and brain microdialysis studies in rats

The motivational properties of the non-peptide delta-opioid receptor agonists BW373U86 and SNC 80 were investigated using the place-conditioning paradigm. BW373U86 (0.5-1.0 mg/kg s.c.) and SNC 80 (1.25-5.0 mg/kg s.c.) elicited significant preference for the drug-paired compartment, in a dose-related fashion. Naltrindole (5.0 mg/kg s.c.) pretreatment, while failing to modify preference when given alone, completely prevented place-preference induced by BW373U86 (1.0 mg/kg s.c.) and SNC 80 (1.25 mg/kg s.c.). The dopamine D1 receptor antagonist SCH23390, given at doses that do not affect place-preference (0.012 mg/kg s.c.), completely prevented the place-preference induced by BW373U86 and SNC 80. At the doses effective in eliciting place-preference, BW373U86 and SNC 80 failed to modify extracellular dopamine in the medial nucleus accumbens, while in the dorso-lateral caudate-putamen BW373U86 (1.0 and 2.5 mg/kg s.c.) reduced extracellular dopamine, and this effect was prevented by naltrindole (5.0 mg/kg s.c.). SNC 80, only at the dose of 5 mg/kg s.c., significantly reduced extracellular DA in the dorso-lateral caudate-putamen. The results indicate that stimulation of delta-opioid receptors has incentive properties that might be related to an indirect amplification of post-synaptic dopamine transmission.

(D-Ala2)deltorphin II: D1-dependent stereotypies and stimulation of dopamine release in the nucleus accumbens

In order to investigate the relative role of central delta- and mu-opioid receptors in behavior, the effects of (D-Ala2)deltorphin II, a natural delta-opioid peptide, and PL017, a beta-casomorphin derivative specific for mu receptors, were compared after local intracerebral and intraventricular administration. Intracerebral infusion of the two peptides was done bilaterally in the limbic nucleus accumbens and in the ventral and dorsal caudate putamen of freely moving rats through chronic intracerebral cannulas. After intra-accumbens infusion, the two peptides elicited marked but opposite behavioral effects: while (D-Ala2)deltorphin II evoked dose-dependent motor stimulation characterized by locomotion, sniffing, and oral stereotypies, PL017 elicited motor inhibition with rigidity and catalepsy. These effects were site specific because they could not be evoked from the ventral or from the dorsal caudate. Low doses of naloxone (0.1 mg/kg, s.c.) blocked the effects of PL017 but not those of (D-Ala2)deltorphin II, which instead were reduced by high doses of naloxone (1.0 mg/kg) and by the putative delta-antagonist naltrindole; this drug failed to affect the catalepsy induced by PL017. Therefore, while (D-Ala2)deltorphin II effects were delta-mediated, PL017 effects were mu-mediated. Blockade of dopamine D1 receptors by SCH 23390 abolished (D-Ala2)deltorphin II effects, while blockade of dopamine D2 receptors by raclopride or by haloperidol was without effect. Local application by reverse dialysis of (D-Ala2)deltorphin II (5 microM) to the accumbens resulted in a naloxone-sensitive increase of extracellular dopamine concentrations; these effects could not be evoked from the caudate, nor by PL017 in the accumbens. Intracerebroventricular administration of (D-Ala2)deltorphin II or of PL017 elicited behavioral effects qualitatively similar to those obtained from the accumbens.

SKF 38393 potentiates yawning induced by LY 171555: further evidence against the autoreceptor hypothesis of yawning

The effect of concurrent D-1 receptor stimulation by SKF 38393 on the expression of yawning elicited by D-2 receptor stimulation with LY 171555 was studied in the rat. A low dose of SKF 38393 (2.5 mg/kg SC), while failed to elicit yawning, potentiated the effectiveness of LY 171555 in eliciting yawning at all the doses tested (12.5, 25 and 50 micrograms/kg SC) and this effect was abolished by SCH 23390 (0.012 mg/kg SC). The results indicate that in analogy with typical post-synaptic dopaminergic effects (hypermotility-stereotypy), yawning elicited by a D-2 agonist is facilitated by concurrent stimulation of D-1 receptors and therefore is consistent with previous evidence that yawning in response to a D-2 agonist is not mediated by autoreceptors.

Permissive role of D-1 receptor stimulation for the expression of D-2 mediated behavioral responses: a quantitative phenomenological study in rats

The syndrome of behavioral stimulation induced in male Sprague-Dawley rats by two dopaminergic agents was studied by distinguishing specific behavioral items and quantifying them in terms of their incidence. The specific D-2 agonist LY 171555 elicited yawning, genital grooming, exploratory behavior, downward sniffing and licking but failed to induce gnawing even at high doses. On the other hand, the D-1/D-2 agonist apomorphine elicited the full stereotyped syndrome including gnawing. Depletion of endogenous dopamine (DA) by alpha-methyltyrosine (alpha-MT) prevented the ability of LY 171555 to elicit all the items of behavioral stimulation including the stereotyped ones (sniffing and licking). In contrast, the ability of apomorphine to induce stereotypies was not reduced by depletion of endogenous DA by alpha-MT pretreatment. Blockade of D-1 receptors with SCH 23390 abolished the capacity of both LY 171555 and apomorphine to elicit all the items of behavioral stimulation. In alpha-MT pretreated rats, administration of low doses of the D-1 agonist SKF 38393 (2.5 mg/kg s.c.) reinstated the ability of LY 171555 to elicit behavioral stimulation and eventually conferred the ability of inducing gnawing. The results support the hypothesis that stimulation of D-1 receptors exerts a permissive role for the expression of behavioral stimulation following D-2 receptor stimulation. Endogenous DA appears to provide sufficient D-1 input to permit full expression of yawning, genital grooming, exploratory behavior, downward sniffing and licking following D-2 stimulation; pharmacological stimulation of D-1 in addition to D-2 receptors seems however necessary for full expression of the highest rank stereotypy item, gnawing.

Permissive role of D-1 receptor stimulation by endogenous dopamine for the expression of postsynaptic D-2-mediated behavioural responses. Yawning in rats

Low doses of BHT 920, LY 171555 and (+)3PPP, three dopamine agonists selective for D-2 receptors, induced yawning in rats. This effect was reduced by the selective D-1 antagonist SCH 23390 but the antagonism did not exceed a 50% reduction from the control values. In contrast, the selective D-2 antagonist (-)sulpiride completely abolished agonist-induced yawning. A 6 h reserpine pretreatment (5 mg/kg i.p.), which depletes brain dopamine (DA) by about 95%, reduced agonist-induced yawning by an extent similar to SCH 23390; in the reserpinized rats, SCH 23390 completely lost the property of blocking agonist-induced yawning while (-)sulpiride retained it. Two 5HT receptor antagonist, ketanserin and metergoline failed to influence agonist-induced yawning. The reportedly selective D-1 agonist, SKF 38393, failed to induce yawning in normal rats as well as in rats pretreated with reserpine 6 or 16 h earlier. If one excludes that SCH 23390 and the D-2 agonists interact with the same DA-receptors, the data are consistent with the possibility that stimulation of D-1 receptors by endogenous DA plays a permissive-facilitatory role for the behavioural expression of D-2 receptor activation.

Dopaminergic D-1 receptors: essential role in morphine-induced hypermotility

Administration of morphine HCl (20 mg/kg SC) to male C57Bl/6 mice evoked hypermotility. Pretreatment with low doses of the specific D-1 antagonist SCH 23390 (0.006, 0.012, 0.025 mg/kg SC) dose-dependently inhibited morphine-evoked hypermotility. The results suggest that dopamine is the essential mediator of opiate hypermotility and indicate that D-1 receptors play an important role in this effect.

Antagonism of apomorphine-induced yawning by SCH 23390: evidence against the autoreceptor hypothesis

The ability of apomorphine to induce yawning (YWG) in normal and reserpinized rats and its interaction with SCH 23390, a potent and specific D-1 receptor antagonist, was studied. Apomorphine was more potent in inducing YWG in reserpine-pretreated as compared to control rats. SCH 23390, in low doses (0.05 mg/kg SC), was able to significantly reduce the YWG evoked by apomorphine both in control and in reserpine-pretreated rats. The results indicate that D-1 receptors contribute to YWG elicited by apomorphine and contradict the idea that this effect is mediated by DA autoreceptors.

Ipsiversive turning behaviour after discrete unilateral lesions of the dorsal mesencephalic reticular formation by kainic acid

Discrete axon-sparing lesions were placed unilaterally in the mesencephalon by the local injection of kainic acid. Unilateral lesions of the dorsal reticular formation just beneath the superior colliculus and lateral to the periacqueductal grey resulted in consistent ipsiversive apomorphine-induced circling. Only weak motor asymmetries were observed after unilateral lesions restricted to the superior colliculus or to the periacqueductal grey. The results indicate that the dorsal mesencephalic reticular formation plays an essential role as an output station for striatal postural functions.