Interaction of high-fat diet and brain trauma alters adipose tissue macrophages and brain microglia associated with exacerbated cognitive dysfunction

Obesity increases the morbidity and mortality of traumatic brain injury (TBI). Detailed analyses of transcriptomic changes in the brain and adipose tissue were performed to elucidate the interactive effects between high-fat diet-induced obesity (DIO) and TBI. Adult male mice were fed a high-fat diet (HFD) for 12 weeks prior to experimental TBI and continuing after injury. High-throughput transcriptomic analysis using Nanostring panels of the total visceral adipose tissue (VAT) and cellular components in the brain, followed by unsupervised clustering, principal component analysis, and IPA pathway analysis were used to determine shifts in gene expression patterns and molecular pathway activity. Cellular populations in the cortex and hippocampus, as well as in VAT, during the chronic phase after combined TBI-HFD showed amplification of central and peripheral microglia/macrophage responses, including superadditive changes in selected gene expression signatures and pathways. Furthermore, combined TBI and HFD caused additive dysfunction in Y-Maze, Novel Object Recognition (NOR), and Morris water maze (MWM) cognitive function tests. These novel data suggest that HFD-induced obesity and TBI can independently prime and support the development of altered states in brain microglia and VAT, including the disease-associated microglia/macrophage (DAM) phenotype observed in neurodegenerative disorders. The interaction between HFD and TBI promotes a shift toward chronic reactive microglia/macrophage transcriptomic signatures and associated pro-inflammatory disease-altered states that may, in part, underlie the exacerbation of cognitive deficits. Thus, targeting of HFD-induced reactive cellular phenotypes, including in peripheral adipose tissue immune cell populations, may serve to reduce microglial maladaptive states after TBI, attenuating post-traumatic neurodegeneration and neurological dysfunction.

Interaction of high-fat diet and brain trauma alters adipose tissue macrophages and brain microglia associated with exacerbated cognitive dysfunction

Obesity increases the morbidity and mortality of traumatic brain injury (TBI). We performed a detailed analysis of transcriptomic changes in the brain and adipose tissue to examine the interactive effects between high-fat diet-induced obesity (DIO) and TBI in relation to central and peripheral inflammatory pathways, as well as neurological function. Adult male mice were fed a high-fat diet (HFD) for 12 weeks prior to experimental TBI and continuing after injury. Combined TBI and HFD resulted in additive dysfunction in the Y-Maze, novel object recognition (NOR), and Morris water maze (MWM) cognitive function tests. We also performed high-throughput transcriptomic analysis using Nanostring panels of cellular compartments in the brain and total visceral adipose tissue (VAT), followed by unsupervised clustering, principal component analysis, and IPA pathway analysis to determine shifts in gene expression programs and molecular pathway activity. Analysis of cellular populations in the cortex and hippocampus as well as in visceral adipose tissue during the chronic phase after combined TBI-HFD showed amplification of central and peripheral microglia/macrophage responses, including superadditive changes in select gene expression signatures and pathways. These data suggest that HFD-induced obesity and TBI can independently prime and support the development of altered states in brain microglia and visceral adipose tissue macrophages, including the disease-associated microglia/macrophage (DAM) phenotype observed in neurodegenerative disorders. The interaction between HFD and TBI promotes a shift toward chronic reactive microglia/macrophage transcriptomic signatures and associated pro-inflammatory disease-altered states that may, in part, underlie the exacerbation of cognitive deficits. Targeting of HFD-induced reactive cellular phenotypes, including in peripheral adipose tissue macrophages, may serve to reduce microglial maladaptive states after TBI, attenuating post-traumatic neurodegeneration and neurological dysfunction.

Stigmatization attitudes of medical staff toward people with respiratory syndromes during COVID-19 pandemic

Introduction

The health care workers have extremely high risks of adverse psychological reactions from COVID-19 pandemic. On the other hand, patients with respiratory syndromes face stigmatization due to their possible contagiousness of SARS-Cov-2.

Objectives

To study the association of behavior, psychological distress in health care workers, and their stigmatization attitudes to the patients.

Methods

The online-survey of 1800 health care workers performed during different lockdown periods in Russia: the first week and the last (30/Mar-5/Apr/20 and 4-10/May/20). The Psychological stress scale (PSM-25), modified Perceived devaluation-discrimination scale (Cronbach’s α=0.74) were used. Dispersion analysis with p-value=0.05 and Cohen’s d, Cramer’s V calculation (ES) performed.

Results

In the 2nd phase medical stuff more often wore masks (64% vs. 89%; χ2=98.7, p=0.000, df=1; ES=0.23) and gloves (30% vs. 57%; χ2=57.6, p=0.000, df=1; ES=0.18), continued perform hand hygiene (94-95%) and physical distancing (73-74%), but was restricted in most effective protective measure: self-isolation (49% vs. 36%; χ2=16.0, p=0.000, df=1; ES=1.0). The psychological stress levels decreased in the 2nd phase (ES=0.13), while the stigma levels (ES=0.33) increased. Physicians experienced more stress compared with nurses and paramedical personnel (ES=0.34; 0.64) but were less likely to stigmatize SARS-CoV-2 infected individuals (ES=0.43; 0.41). The highest rates of contacts with COVID-19 patients (83%) were reported by physicians (χ2=123.0; p = 0.00, df=4; ES=0.28).

Conclusions

Direct contact with SARS-Cov-2 is associated with a significant increase in stress among medical personnel. However, the stigmatizing reactions are not directly associated with the risks of infection and are most prevalent among nurses and paramedical personnel.

Stress and affective disorders in COVID-19 pandemic: On-line survey of russian respondents in different cities of residence

Introduction

The psychological stress associated with the COVID-19 pandemic has a complex multifactorial nature.

Objectives

The aim: to evaluate the level of stress during the COVID-19 pandemic in the Russian-speaking population with(-out) affective disorders in different cities of residence.

Methods

The data obtained from an online survey of 4803 Russian-speaking respondents (age over 18) from March 30 to May 18, 2020. The survey included social, demographic and the history of affective disorders data. The anxiety distress level was evaluated with the Psychological Stress Measure (PSM-25).

Results

Individuals from sub-cohort of Russian cities with populations less than one million had higher stress levels (M=135.39) compared to Moscow (M=129.47; p=0.003) or St.-Petersburg (M=126.63; p<0.001). However, stress scores in respondents with a history of affective disorders correspond to the average stress level according to PSM-25. Respondents without affective disorders from St.-Petersburg reported lower stress levels (M=92.88) than respondents from Moscow (M=100.47; p<0.001) and Russian cities with less than one million population (M=98.4; p<0.001). Average stress scores from St.-Petersburg and other Russian cities show a low level of stress on PSM-25, which indicates psychological adaptation. Stress scores from Moscow have borderline values between low and medium levels.

Conclusions

Our study showed that the city of residence and affective disorders status significantly affect stress levels in Russian population. These factors could be further used in individual psychological support strategies.

Mithramycin selectively attenuates DNA-damage-induced neuronal cell death

DNA damage triggers cell death mechanisms contributing to neuronal loss and cognitive decline in neurological disorders, including traumatic brain injury (TBI), and as a side effect of chemotherapy. Mithramycin, which competitively targets chromatin-binding sites of specificity protein 1 (Sp1), was used to examine previously unexplored neuronal cell death regulatory mechanisms via rat primary neurons in vitro and after TBI in mice (males). In primary neurons exposed to DNA-damage-inducing chemotherapy drugs in vitro we showed that DNA breaks sequentially initiate DNA-damage responses, including phosphorylation of ATM, H2AX and tumor protein 53 (p53), transcriptional activation of pro-apoptotic BH3-only proteins, and mitochondrial outer membrane permeabilization (MOMP), activating caspase-dependent and caspase-independent intrinsic apoptosis. Mithramycin was highly neuroprotective in DNA-damage-dependent neuronal cell death, inhibiting chemotherapeutic-induced cell death cascades downstream of ATM and p53 phosphorylation/activation but upstream of p53-induced expression of pro-apoptotic molecules. Mithramycin reduced neuronal upregulation of BH3-only proteins and mitochondrial dysfunction, attenuated caspase-3/7 activation and caspase substrates' cleavage, and limited c-Jun activation. Chromatin immunoprecipitation indicated that mithramycin attenuates Sp1 binding to pro-apoptotic gene promoters without altering p53 binding suggesting it acts by removing cofactors required for p53 transactivation. In contrast, the DNA-damage-independent neuronal death models displayed caspase initiation in the absence of p53/BH3 activation and were not protected even when mithramycin reduced caspase activation. Interestingly, experimental TBI triggers a multiplicity of neuronal death mechanisms. Although markers of DNA-damage/p53-dependent intrinsic apoptosis are detected acutely in the injured cortex and are attenuated by mithramycin, these processes may play a reduced role in early neuronal death after TBI, as caspase-dependent mechanisms are repressed in mature neurons while other, mithramycin-resistant mechanisms are active. Our data suggest that Sp1 is required for p53-mediated transactivation of neuronal pro-apoptotic molecules and that mithramycin may attenuate neuronal cell death in conditions predominantly involving DNA-damage-induced p53-dependent intrinsic apoptosis.

Irradiation-Induced Upregulation of miR-711 Inhibits DNA Repair and Promotes Neurodegeneration Pathways

Radiotherapy for brain tumors induces neuronal DNA damage and may lead to neurodegeneration and cognitive deficits. We investigated the mechanisms of radiation-induced neuronal cell death and the role of miR-711 in the regulation of these pathways. We used in vitro and in vivo models of radiation-induced neuronal cell death. We showed that X-ray exposure in primary cortical neurons induced activation of p53-mediated mechanisms including intrinsic apoptotic pathways with sequential upregulation of BH3-only molecules, mitochondrial release of cytochrome c and AIF-1, as well as senescence pathways including upregulation of p21^WAF1/Cip1. These pathways of irradiation-induced neuronal apoptosis may involve miR-711-dependent downregulation of pro-survival genes Akt and Ang-1. Accordingly, we demonstrated that inhibition of miR-711 attenuated degradation of Akt and Ang-1 mRNAs and reduced intrinsic apoptosis after neuronal irradiation; likewise, administration of Ang-1 was neuroprotective. Importantly, irradiation also downregulated two novel miR-711 targets, DNA-repair genes Rad50 and Rad54l2, which may impair DNA damage responses, amplifying the stimulation of apoptotic and senescence pathways and contributing to neurodegeneration. Inhibition of miR-711 rescued Rad50 and Rad54l2 expression after neuronal irradiation, enhancing DNA repair and reducing p53-dependent apoptotic and senescence pathways. Significantly, we showed that brain irradiation in vivo persistently elevated miR-711, downregulated its targets, including pro-survival and DNA-repair molecules, and is associated with markers of neurodegeneration, not only across the cortex and hippocampus but also specifically in neurons isolated from the irradiated brain. Our data suggest that irradiation-induced miR-711 negatively modulates multiple pro-survival and DNA-repair mechanisms that converge to activate neuronal intrinsic apoptosis and senescence. Using miR-711 inhibitors to block the development of these regulated neurodegenerative pathways, thus increasing neuronal survival, may be an effective neuroprotective strategy.

Hydrothermal epitaxy growth of self-organized vanadium dioxide 3D structures with metal–insulator transition and THz transmission switch properties

The hydrothermal method is an effective approach for the synthesis of VO₂ films with unique crystallites morphology and sharp electrical and optical switch properties.

Structural and functional state of heart left ventricle depending on polymorphism rs966221 phosphodiesterase 4D gene in emergency workers of the Chornobyl NPP suffering from coronary heart disease

OBJECTIVE

This study consisted in examination the features of structural and functional state of the cardiovascular system in emergency workers (EW) of the Chernobyl nuclear power plant (ChNPP) who suffered from coronary heart disease (CHD) and having different genotypes due to polymorphism rs966221 phosphodiesterase 4D (PDE4D) gene.

MATERIALS AND METHODS

The study involved 121 EW and 63 non irradiated patients with CHD. Standardized survey included echo doppler cardiography (EchoCG) that was done by Diagnostic Ultrasound System DS N3 (Mindray). Polymorphism rs966221 PDE4D determined by polymerase chain reaction followed by restriction reaction products.

RESULTS

The distribution of genotypes PDE4D in EW was as follows: CC - 42, CT - 49 and TT - 30 patients. In the con trol group, carriers of the same genotypes were 27, 21 and 15 persons respectively. All echocardiographic parame ters in EW workers and non irradiated patients did not differ significantly. Amongst TT genotype carriers of both groups the proportion of patients with increased myocardial mass index was the highest (82.9%) compared to CC genotype (78.4%) and CT (71.4%). The concentric type of left ventricular (LV) hypertrophy was found in 54.9% of patients with CC genotype, in 51.8% with CT genotype and 45.7% with TT genotype, while the eccentric type in 23.5, 21.4 and 37.1% respectively. The relative number of people with high LV end diastolic volume (EDV) normalized by body surface area (BSA) was 27.5% in CC genotype carriers, 26.8% in CT genotype and 40% in TT genotype carriers (p > 0.05). The increase of BSA indexed LV end systolic volume (ESV) was found in 27.5, 30.4 and 28.6%, and the ejection fraction in 15.7, 23.2 and 22.9% respectively. The largest number of CHD patients with inadequate dias tolic function was in carriers of TT genotype (75%) compared with the data in CC (66.7%) and CT genotypes (42.9%) carriers.

CONCLUSIONS

In patients with the same genotype, both EW and non irradiated persons there were virtually no dif ferences in indicators of the structural and functional status of LV. The analysis of changes of LV structure the fol lowing feature was revealed: eccentric type of LV hypertrophy was more common for patients with TT genotype, but concentric type for CC genotype carriers. In one third of patients with CC and CT genotypes and in 40% of TT geno type carriers it was observed LV systolic function disorders. Diastolic dysfunction manifested as often in patients with TT genotype compared with CC and CT genotypes carriers.