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There is strong evidence that neuronal hyper-excitability underlies migraine, and may or may not be preceded by cortical spreading depression. However, the mechanisms for cortical spreading depression and/or migraine are not established. Previous studies reported that cerebrospinal fluid (CSF) [Na+] is higher during migraine, and that higher extracellular [Na+] leads to hyper-excitability. We raise the hypothesis that altered choroid plexus Na+, K+-ATPase activity can cause both migraine phenomena: inhibition raises CSF [K+] and initiates cortical spreading depression, while activation raises CSF [Na+] and causes migraine. In this study, we examined levels of specific Na+, K+-ATPase inhibitors, endogenous ouabain-like compounds (EOLC), in CSF from migraineurs and controls. CSF EOLC levels were significantly lower during ictal migraine (0.4 nM +/- 0.09) than from either controls (1.8 nM +/- 0.4) or interictal migraineurs (3.1 nM +/- 1.9). Blood plasma EOLC levels were higher in migraineurs than controls, but did not differ between ictal and interictal states. In a Sprague-Dawley rat model of nitroglycerin-triggered central sensitization, we changed the concentrations of EOLC and CSF sodium, and measured aversive mechanical threshold (von Frey hairs), trigeminal nucleus caudalis activation (cFos), and CSF [Na+] (ultra-high field 23Na MRI). Animals were sensitized by three independent treatments: intraperitoneal nitroglycerin, immunodepleting EOLC from cerebral ventricles, or cerebroventricular infusion of higher CSF [Na+]. Conversely, nitroglycerin-triggered sensitization was prevented by either vascular or cerebroventricular delivery of the specific Na+, K+-ATPase inhibitor, ouabain. These results affirm our hypothesis that higher CSF [Na+] is linked to human migraine and to a rodent migraine model, and demonstrate that EOLC regulates them both. Our data suggest that altered choroid plexus Na+, K+-ATPase activity is a common source of these changes, and may be the initiating mechanism in migraine.
The study aim was to describe human papillomavirus (HPV)-attributable cancer burden in Rwanda, according to anogenital cancer site, HPV type, age and HIV status. Tissue specimens of cervical, vulvar, vaginal, penile and anal cancer diagnosed in 2012-2018 were retrieved from three cancer referral hospitals and tested for high-risk (HR) HPV DNA. Cervical cancer represented the majority of cases (598 of 738), of which 96.0% were HR-HPV positive. HPV-attributable fractions in other cancer sites varied from 53.1% in 81 penile, through 76.7% in 30 vulvar, 83.3% in 24 vaginal, up to 100% in 5 anal cases. HPV16 was the predominant HR-HPV type in cervical cancer (55.0%), followed by HPV18 (16.6%) and HPV45 (13.4%). HPV16 also predominated in other cancer sites (60-80% of HR-HPV-attributable fraction). For cervical cancer, type-specific prevalence varied significantly by histology (higher alpha-9 type prevalence in 509 squamous cell carcinoma vs. higher alpha-7 type prevalence in 80 adenocarcinoma), but not between 501 HIV-negative and 97 HIV-positive cases. With respect to types targeted, and/or cross-protected, by HPV vaccines, HPV16/18 accounted for 73%, HPV31/33/45/52/58 for an additional 22% and other HR-HPV types for 5%, of HPV-attributable cancer burden, with no significant difference by HIV status nor age. These data highlight the preventive potential of the ongoing national HPV vaccination program in Rwanda, and in sub-Saharan Africa as a whole. Importantly for this region, the impact of HIV on the distribution of causal HPV types was relatively minor, confirming type-specific relevance of HPV vaccines, irrespective of HIV status.
Humans are continuously exposed to chemicals with suspected or proven endocrine disrupting chemicals (EDCs). Risk management of EDCs presents a major unmet challenge because the available data for adverse health effects are generated by examining one compound at a time, whereas real-life exposures are to mixtures of chemicals. In this work, we integrate epidemiological and experimental evidence toward a whole mixture strategy for risk assessment. To illustrate, we conduct the following four steps in a case study: (1) identification of single EDCs ("bad actors")-measured in prenatal blood/urine in the SELMA study-that are associated with a shorter anogenital distance (AGD) in baby boys; (2) definition and construction of a "typical" mixture consisting of the "bad actors" identified in Step 1; (3) experimentally testing this mixture in an in vivo animal model to estimate a dose-response relationship and determine a point of departure (i.e., reference dose [RfD]) associated with an adverse health outcome; and (4) use a statistical measure of "sufficient similarity" to compare the experimental RfD (from Step 3) to the exposure measured in the human population and generate a "similar mixture risk indicator" (SMRI). The objective of this exercise is to generate a proof of concept for the systematic integration of epidemiological and experimental evidence with mixture risk assessment strategies. Using a whole mixture approach, we could find a higher rate of pregnant women under risk (13%) when comparing with the data from more traditional models of additivity (3%), or a compound-by-compound strategy (1.6%).
Yeast carboxypeptidase Y (CPY) is a serine protease with broad substrate specificity. Structurally, CPY belongs to the α/β hydrolase fold family and contains characteristic large helices, termed the V-shape helix, above the active site cavity. Four intramolecular disulfide bonds are located in and around the V-shape helix. In this study, mutant CPYs were constructed in which one of these disulfide bonds was disrupted. Mutants lacking the C193-C207 bond located at the beginning of the V-shape helix aggregated easily, while mutants lacking the C262-C268 bond located at the end of the V-shape helix displayed decreased hydrolytic activity. The results indicate that the V-shape helix is involved in CPY catalysis and in maintenance of its conformation.
The blood-brain barrier (BBB) tightly regulates the entry of solutes from blood into the brain and is disrupted in several neurological diseases. Using Organ-Chip technology, we created an entirely human BBB-Chip with induced pluripotent stem cell (iPSC)-derived brain microvascular endothelial-like cells (iBMECs), astrocytes, and neurons. The iBMECs formed a tight monolayer that expressed markers specific to brain vasculature. The BBB-Chip exhibited physiologically relevant transendothelial electrical resistance and accurately predicted blood-to-brain permeability of pharmacologics. Upon perfusing the vascular lumen with whole blood, the microengineered capillary wall protected neural cells from plasma-induced toxicity. Patient-derived iPSCs from individuals with neurological diseases predicted disease-specific lack of transporters and disruption of barrier integrity. By combining Organ-Chip technology and human iPSC-derived tissue, we have created a neurovascular unit that recapitulates complex BBB functions, provides a platform for modeling inheritable neurological disorders, and advances drug screening, as well as personalized medicine.
Gene regulatory networks underpinning skeletal muscle determination and differentiation have been extensively investigated, providing molecular insights into how cell lineages are established during development. These studies have exclusively focused on the transcriptome downstream of RNA polymerase II (Pol II). RNA polymerase III (Pol III) drives the production of tRNAs and other small RNAs essential for the flow of genetic information from gene to protein and we have found that a specific isoform of a subunit unique to Pol III is expressed early in the myogenic lineage. This points to the possibility that additional regulatory networks exist to control the production of Pol III transcripts during skeletal muscle differentiation. We describe the differential expression of Polr3g and its alternate isoform Polr3gL during embryonic development and using a custom tRNA microarray, we demonstrate their distinct activity on the synthesis of tRNA isoacceptors. We show that Pol III dependent transcripts are dramatically down-regulated during the differentiation of skeletal muscle, as are mRNAs coding for Pol III associated proteins Brf1 and Brf2, while Polr3gL is up-regulated alongside contractile protein genes. Forcing Polr3g expression in this context results in a partial reversal of myogenic differentiation.
Age-related cognitive decline has been associated with proinflammatory cytokines, yet the precise relationship between cognitive decline and cytokine load remains to be elucidated. β-caryophyllene (BCP) is a cannabinoid receptor 2 (CB2) agonist with established anti-inflammatory effects that is known to improve memory and increase lifespan. It is of interest to explore the potential of BCP to reduce age-related cognitive decline and proinflammatory cytokine load. In this study, we assessed changes in circulating cytokines across the lifespan, memory performance in young and aged mice, and the effects of BCP on memory function and cytokine load. The plasma levels of 12 cytokines were assessed in male Swiss-Webster mice at 3, 12, and 18 months of age using multiplexed flow cytometry. Working memory was compared in 3 and 12 month-old mice using spontaneous alternations. A dose-response function (100-300 mg/kg, subchronic administration) for BCP-induced memory restoration was determined in 3- and 12- month-old mice. Finally, the effects on cytokine levels of the peak memory enhancing dose of BCP were assessed in 18- month-old mice. Circulating levels of several cytokines significantly increased with age. Multilinear regression analysis showed that IL-23 levels were most strongly associated with age. Aged mice showed deficits in working memory and higher levels of IL-23, both of which were reversed by BCP treatment. BCP appears to reverse age-associated impairments in memory and modulates cytokine production. IL-23 may play a significant role in the aging process, and future research should determine whether it has utility as a biomarker for novel anti-aging therapeutics.
We study the impairment of locomotion and rearing behavior in rats with a common bile duct ligation (BDL), and the possible involvement of the PKCγ and CamKIIα gene expression in the brain. Male Wistar rats undergo either sham operation or BDL to induce a rat model of cirrhotic hepatic encephalopathy (HE). Six groups of the animals were divided into three sets of sham-operated and BDL groups. In the first set, locomotion and rearing behavior were assessed on days 1, 7, 14, 21 and 28 of BDL. On day 28 of BDL, blood samples were collected from the second set of the animals for biochemical analysis, and the rats in the third set were used to extract the PFC, the hippocampus, and the cerebellar cortex for examining the Pkcγ and CamKIIα gene expression. The results showed that locomotion and rearing were decreased during 28 days of BDL with the most significant change on the 28th day. Biochemical analysis of the blood revealed hyperammonemia, increases in liver enzymes, and a decrease in albumin indicating liver damage and induction of cirrhotic HE. The results also showed that both of the Pkcγ and CamKIIα gene expressions were increased in the PFC but decreased in the hippocampus. However, the Pkcγ gene expression was decreased but the CamKIIα gene expression was increased in the cerebellar cortex. It can be concluded that the Ca2+-dependent kinases in different brain areas have a site-specific association with the impairment of locomotion and rearing behavior in the cirrhotic HE model rats.
The allocentric representation of space is a fundamental pillar of episodic experience. In infant rats, the neural circuitry underlying the formation of allocentric spatial representations is functioning from early on when eyes are opening, i.e., before postnatal day (PD) 15. However, it remains unclear when and how during early development rats use these representations to regulate spatial behavior. Here, we studied indicators of memory-based spatial navigation using a classical object-place recognition (OPR) task set-up in infant (PD15), pre-weanling (PD18), juvenile (PD25), peri-adolescent (PD31), adolescent (PD38, PD48), and young adult rats (PD84). On the task, rats explored an arena with two identical objects, and memory was tested in a recall phase 3 h later in the same arena with, one object displaced from its original location. Only at adolescence (PD38), rats showed the typical adult-like expression of allocentric spatial memory with a preferential exploration of the object at the novel location. However, the first expression of allocentric spatial memory was revealed already in PD18 rats, which contrasting with PD84 rats, showed a preference to explore the object at the familiar location. At PD31, rats showed a null preference between the object-locations. Nevertheless, spatial memory at this age expressed in a preference for the zone including the familiar object-location. In PD15 rats, we found no evidence for a memory-based organization of spatial behavior. In conclusion, although rats might be able to form allocentric neuronal representations of space already earlier, only from PD18 on, such representations are used to organize spatial behavior, with a motivational shift from familiarity to novelty-driven navigation occurring during adolescence.
Circulating microRNAs (miRNAs) in peripheral blood have been extensively investigated as biomarkers for early diagnosis and monitoring of disease progression. However, their cellular origin as well as their link to the pathophysiology, especially neurodegenerative disease, remains largely unknown. In the present study, we isolated neuron-derived extracellular vesicles (EVs) in plasma by immunoaffinity purification and comprehensively analyzed their miRNA expression profiles using microarray. A total of 30 miRNAs were differentially regulated in amyotrophic lateral sclerosis (ALS) plasma relative to healthy control plasma. Gene ontology analysis revealed that biological processes implicated in both up-regulated and down-regulated miRNAs were involved in synaptic vesicle-related pathways. Especially, 4 miRNAs in plasma neuro-derived EVs seemed to be regulated in the similar manner as those in formalin-fixed paraffin-embedded motor cortex samples from ALS patients. The target genes for the 4 miRNAs partly overlapped in STX1B, RAB3B, and UNC13A genes. UNC13A has been reported to be associated with increased odds of sporadic ALS in multiple genome-wide association studies. Our data suggest that miRNAs extracted from neuron-derived EVs in plasma reflect miRNA alterations in the brain as potential biomarkers of ALS.
Exosomal transfer of oncogenic miRNAs can enhance recipient cell growth, metastasis and chemoresistance. Currently we found that microRNA-501-5p (miR-501) was overexpressed in doxorubicin-resistant gastric cancer (GC) SGC7901/ADR cell-secreted exosomes (ADR Exo) than that in SGC7901 cell-secreted exosomes (7901 Exo). ADR Exo was internalized by SGC7901, and a Cy3-miR-501 mimic was transferred from SGC7901/ADR to SGC7901 via exosomes. ADR Exo conferred doxorubicin resistance, proliferation, migration and invasion abilities to negative control miRNA inhibitor-expressing GC cells, whereas it inhibited apoptosis. MiR-501 knockdown or BH3-like motif-containing protein, cell death inducer (BLID) overexpression could reverse the effects of ADR Exo on recipient cells. SGC7901 cells cocultured with SGC7901/ADR prior to treatment with GW4869 or transfection of a miR-501 inhibitor were sensitive to doxorubicin and exhibited attenuated proliferation, migration and invasion and increased apoptosis. The intratumoral injection of ADR Exo into negative control miRNA inhibitor-expressing SGC7901 cells induced rapid subcutaneous tumor growth and resistance to doxorubicin compared to that of miR-501 knockdown or BLID-overexpressing cells. This effect is possibly achieved by exosomal miR-501-induced downregulation of BLID, subsequent inactivation of caspase-9/-3 and phosphorylation of Akt. Exosomal miR-501 might be a therapeutic target for GC.
Incomplete radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) could initiate malignant transition. Patient-derived xenograft (PDX) mice model was established to investigate the effect of VEGF pathway in incomplete RFA of HCC with high fidelity. Cancer stem cell markers and metastatic markers were increased after incomplete RFA, with increased VEGFR1 and decreased VEGFR2 expression. In vitro experiments revealed sublethal heat treatment promoted migration ability of HepG2, HCCLM3, and SMMC7721 cells, which coincided with enhanced ability of sphere formation and up-regulation of VEGFR1, CD133, CD44, and EpCAM. Moreover, HCC cells secreted more VEGF after heat-treatment. VEGF promoted migration and enhanced stemness of HCC cells, which could not be suppressed by VEGFR2 inhibitor. PIGF, the ligand of VEGFR1, significantly increased migration and stemness of HCC cells. Blocking VEGFR1 reduced heat-induced enhancement of migration and stemness, whereas inhibition of VEGFR2 could not. In conclusion, VEGFR1 plays a critical role in sublethal heat treatment-induced enhancement of migration and stemness in HCC, suggesting that VEGFR1 may serve as a potential and promising therapeutic target for preventing recurrence after RFA.
Both obesity and low vitamin D levels have been associated with allergic asthma (AA) severity. In the present study, severity of AA was associated with obesity but to the in vitro IgE production. In those patients, higher levels of IL-5, IL-6 and IL-17 were quantified in CD4+ T-cell cultures as compared with patients with mild and moderate AA. In addition, the lowest IL-10 levels were detected in the cell cultures from patients with a worse prognosis. Interestingly, the occurrence of AA elevates the plasma levels of leptin, and this adipokine was positively correlated with the release of IL-5, IL-6 and IL-17, but inversely correlated with IL-10 production, by CD4+ T-cells from patients. In AA-derived CD4+ T-cell cultures, 1,25(OH)2D3 was less efficient at inhibiting IL-5, IL-6 and IL-17 production, and up regulating IL-10 release, as those from healthy subjects. Interestingly, the in vitro immunomodulatory effects of vitamin D were inversely correlated with serum leptin levels. In summary, our findings suggested that obesity, probably due to the overproduction of leptin, negatively impacts AA as it favors imbalance between Th2/Th17 and regulatory phenotypes. The deleterious effects of leptin may also be due to its ability to counter-regulate the immunosuppressive effects of vitamin D.
Acute stress triggers a broad psychophysiological response that is adaptive if rapidly activated and terminated. While the brain controls the stress response, it is strongly affected by it. Previous research of stress effects on brain activation and connectivity has mainly focused on pre-defined brain regions or networks, potentially missing changes in the rest of the brain. We here investigated how both stress reactivity and stress recovery are reflected in whole-brain network topology and how changes in functional connectivity relate to other stress measures. Healthy young males (n = 67) completed the Trier Social Stress Test or a control task. From 60 min before until 105 min after stress onset, blocks of resting-state fMRI were acquired. Subjective, autonomic, and endocrine measures of the stress response were assessed throughout the experiment. Whole-brain network topology was quantified using Eigenvector centrality (EC) mapping, which detects central hubs of a network. Stress influenced subjective affect, autonomic activity, and endocrine measures. EC differences between groups as well as before and after stress exposure were found in the thalamus, due to widespread connectivity changes in the brain. Stress-driven EC increases in the thalamus were significantly correlated with subjective stress ratings and showed non-significant trends for a correlation with heart rate variability and saliva cortisol. Furthermore, increases in thalamic EC and in saliva cortisol persisted until 105 min after stress onset. We conclude that thalamic areas are central for information processing after stress exposure and may provide an interface for the stress response in the rest of the body and in the mind.
The mechanism for nitric oxide (NO) generation from reduction of nitrate (NO3-) and nitrite (NO2-) has gained increasing attention due to the potential beneficial effects of NO in cardiovascular diseases and exercise performance. We have previously shown in rodents that skeletal muscle is the major nitrate reservoir in the body and that exercise enhances the nitrate reduction pathway in the muscle tissue and have proposed that nitrate in muscle originates from diet, the futile cycle of nitric oxide synthase 1 (NOS1) and/or oxidation of NO by oxymyoglobin. In the present study, we tested the hypothesis that lack of myoglobin expression would decrease nitrate levels in skeletal muscle. We observed a modest but significant decrease of nitrate level in skeletal muscle of myoglobin deficient mice compared to littermate control mice (17.3 vs 12.8 nmol/g). In contrast, a NOS inhibitor, L-NAME or a low nitrite/nitrate diet treatment led to more pronounced decreases of nitrate levels in the skeletal muscle of both control and myoglobin deficient mice. Nitrite levels in the skeletal muscle of both types of mice were similar (0.48 vs 0.42 nmol/g). We also analyzed the expression of several proteins that are closely related to NO metabolism to examine the mechanism by which nitrate and nitrite levels are preserved in the absence of myoglobin. Western blot analyses suggest that the protein levels of xanthine oxidoreductase and sialin, a nitrate transporter, both increased in the skeletal muscle of myoglobin deficient mice. These results are compatible with our previously reported model of nitrate production in muscle and suggest that myoglobin deficiency activates compensatory mechanisms to sustain NO homeostasis.
Though the cross-induction of either acute kidney (AKI) injury to ischemic stroke (IS) or IS to AKI might not be encountered in the early stages of cerebrorenal syndrome (CRS), both pathologies coexist in late stages. Therefore, we firstly established a late stage CRS rat model by simultaneous induction of both diseases, and further, cerebro and reno-protective activities of human platelet-rich plasma (hPRP), a blood-derived tissue engineering biomaterial, were tested in this pathology. hPRP was administrated via left common carotid artery and abdominal aorta 2 h post-sham procedure in Sprague-Dawley rats. Circulatory inflammatory markers (TNF-α/MPO/IL-6/Ly6G/CD11b/c), histopathologic cerebro and renal changes and oxidative stress were determined. Inflammation, infarct size, brain-associated inflammatory/DNA and mitochondrial damage and oxidative-stress with reduced neurons and neurological function were manifested in CRS group compared to other groups. CRS group also demonstrated declined renal function, accelerated renal collagen deposition, fibrosis and compromised glomerular podocyte components (podocin/ZO-1/fibronectin/synaptopodin). However, hPRP simultaneously suppressed all the inflammatory, cerebral and renal pathologic characteristics. hPRP also inhibited the expression of brain-associated inflammatory/DNA/mitochondrial damage and oxidative-stress biomarkers. These findings imply that hPRP may effectively exert cerebro- and renoprotective activities in late stage CRS through anti-oxidative, anti-inflammatory, anti-DNA and anti-mitochochondrial damaging activities.
Numerous brain disorders are associated with ventriculomegaly, including both neuro-degenerative diseases and cerebrospinal fluid disorders. Detailed evaluation of the ventricular system is important for these conditions to help understand the pathogenesis of ventricular enlargement and elucidate novel patterns of ventriculomegaly that can be associated with different diseases. One such disease is normal pressure hydrocephalus (NPH), a chronic form of hydrocephalus in older adults that causes dementia. Automatic parcellation of the ventricular system into its sub-compartments in patients with ventriculomegaly is quite challenging due to the large variation of the ventricle shape and size. Conventional brain labeling methods are time-consuming and often fail to identify the boundaries of the enlarged ventricles. We propose a modified 3D U-Net method to perform accurate ventricular parcellation, even with grossly enlarged ventricles, from magnetic resonance images (MRIs). We validated our method on a data set of healthy controls as well as a cohort of 95 patients with NPH with mild to severe ventriculomegaly and compared with several state-of-the-art segmentation methods. On the healthy data set, the proposed network achieved mean Dice similarity coefficient (DSC) of 0.895 ± 0.03 for the ventricular system. On the NPH data set, we achieved mean DSC of 0.973 ± 0.02, which is significantly (p < 0.005) higher than four state-of-the-art segmentation methods we compared with. Furthermore, the typical processing time on CPU-base implementation of the proposed method is 2 min, which is much lower than the several hours required by the other methods. Results indicate that our method provides: 1) highly robust parcellation of the ventricular system that is comparable in accuracy to state-of-the-art methods on healthy controls; 2) greater robustness and significantly more accurate results on cases of ventricular enlargement; and 3) a tool that enables computation of novel imaging biomarkers for dilated ventricular spaces that characterize the ventricular system.
The gene delivery to skeletal muscles is a promising strategy for the treatment of both muscular disorders (by silencing or overexpression of specific gene) and systemic secretion of therapeutic proteins. The use of a physical method like electroporation with plate or needle electrodes facilitates long-lasting gene silencing in situ. It has been reported that electroporation enhances the expression of the naked DNA gene in the skeletal muscle up to 100 times and decreases the changeability of the intramuscular expression. Coelectransfer of reporter genes such as green fluorescent protein (GFP), luciferase or beta-galactosidase allows the observation of correctly performed silencing in the muscles. Appropriate selection of plasmid injection volume and concentration, as well as electrotransfer parameters, such as the voltage, the length and the number of electrical pulses do not cause long-term damage to myocytes. In this review, we summarized the electroporation methodology as well as the procedure of electrotransfer to the gastrocnemius, tibialis, soleus and foot muscles and compare their advantages and disadvantages.
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