Many of the symptoms of Gulf War Illness (GWI) that include neurological abnormalities, neuroinflammation, chronic fatigue and gastrointestinal disturbances have been traced to Gulf War chemical ...exposure. Though the association and subsequent evidences are strong, the mechanisms that connect exposure to intestinal and neurological abnormalities remain unclear. Using an established rodent model of Gulf War Illness, we show that chemical exposure caused significant dysbiosis in the gut that included increased abundance of phylum Firmicutes and Tenericutes, and decreased abundance of Bacteroidetes. Several gram negative bacterial genera were enriched in the GWI-model that included Allobaculum sp. Altered microbiome caused significant decrease in tight junction protein Occludin with a concomitant increase in Claudin-2, a signature of a leaky gut. Resultant leaching of gut caused portal endotoxemia that led to upregulation of toll like receptor 4 (TLR4) activation in the small intestine and the brain. TLR4 knock out mice and mice that had gut decontamination showed significant decrease in tyrosine nitration and inflammatory mediators IL1β and MCP-1 in both the small intestine and frontal cortex. These events signified that gut dysbiosis with simultaneous leaky gut and systemic endotoxemia-induced TLR4 activation contributes to GW chemical-induced neuroinflammation and gastrointestinal disturbances.
Exposure to crude oil or its individual constituents can have detrimental impacts on fish species, including impairment of the immune response. Increased observations of skin lesions in northern Gulf ...of Mexico fish during the 2010 Deepwater Horizon oil spill indicated the possibility of oil-induced immunocompromisation resulting in bacterial or viral infection. This study used a full factorial design of oil exposure and bacterial challenge to examine how oil exposure impairs southern flounder (Paralichthys lethostigma) immune function and increases susceptibility to the bacteria Vibrio anguillarum, a causative agent of vibriosis. Fish exposed to oil prior to bacterial challenge exhibited 94.4% mortality within 48 hours of bacterial exposure. Flounder challenged with V. anguillarum without prior oil exposure had <10% mortality. Exposure resulted in taxonomically distinct gill and intestine bacterial communities. Mortality strongly correlated with V. anguillarum levels, where it comprised a significantly higher percentage of the microbiome in Oil/Pathogen challenged fish and was nearly non-existent in the No Oil/Pathogen challenged fish bacterial community. Elevated V. anguillarum levels were a direct result of oil exposure-induced immunosuppression. Oil-exposure reduced expression of immunoglobulin M, the major systemic fish antibody, and resulted in an overall downregulation in transcriptome response, particularly in genes related to immune function, response to stimulus and hemostasis. Ultimately, sediment-borne oil exposure impairs immune function, leading to increased incidences of bacterial infections. This type of sediment-borne exposure may result in long-term marine ecosystem effects, as oil-bound sediment in the northern Gulf of Mexico will likely remain a contamination source for years to come.
Intermittent fasting (IF) protects against the development of metabolic diseases and cancer, but whether it can prevent diabetic microvascular complications is not known. In
mice, we examined the ...impact of long-term IF on diabetic retinopathy (DR). Despite no change in glycated hemoglobin,
mice on the IF regimen displayed significantly longer survival and a reduction in DR end points, including acellular capillaries and leukocyte infiltration. We hypothesized that IF-mediated changes in the gut microbiota would produce beneficial metabolites and prevent the development of DR. Microbiome analysis revealed increased levels of Firmicutes and decreased Bacteroidetes and Verrucomicrobia. Compared with
mice on ad libitum feeding, changes in the microbiome of the
mice on IF were associated with increases in gut mucin, goblet cell number, villi length, and reductions in plasma peptidoglycan. Consistent with the known modulatory effects of Firmicutes on bile acid (BA) metabolism, measurement of BAs demonstrated a significant increase of tauroursodeoxycholate (TUDCA), a neuroprotective BA, in
on IF but not in
on AL feeding. TGR5, the TUDCA receptor, was found in the retinal primary ganglion cells. Expression of TGR5 did not change with IF or diabetes. However, IF reduced retinal TNF-α mRNA, which is a downstream target of TGR5 activation. Pharmacological activation of TGR5 using INT-767 prevented DR in a second diabetic mouse model. These findings support the concept that IF prevents DR by restructuring the microbiota toward species producing TUDCA and subsequent retinal protection by TGR5 activation.
Metabolic and molecular interactions between branched-chain amino acid (BCAA) and lipid metabolism are evident in insulin-resistant tissues. However, it remains unclear whether insulin resistance is ...a prerequisite for these relationships and whether BCAAs or their metabolic intermediates can modulate hepatic lipid oxidation and synthesis. We hypothesized that BCAAs can alter hepatic oxidative function and de novo lipogenesis, independent of them being anaplerotic substrates for the mitochondria. Mice (C57BL/6NJ) were reared on a low-fat (LF), LF diet plus 1.5X BCAAs (LB), high-fat (HF) or HF diet plus 1.5X BCAAs (HB) for 12 wk. Hepatic metabolism was profiled utilizing stable isotopes coupled to mass spectrometry and nuclear magnetic resonance, together with fed-to-fasted changes in gene and protein expression. A greater induction of lipid oxidation and ketogenesis on fasting was evident in the BCAA-supplemented, insulin-sensitive livers from LB mice, whereas their rates of hepatic de novo lipogenesis remained lower than their LF counterparts. Onset of insulin resistance in HF and HB mice livers blunted these responses. Whole body turnover of BCAAs and their ketoacids, their serum concentrations, and the ketogenic flux from BCAA catabolism, all remained similar between fasted LF and LB mice. This suggested that the impact of BCAAs on lipid metabolism can occur independent of them or their degradation products fueling anaplerosis through the liver mitochondria. Furthermore, the greater induction of lipid oxidation in the LB livers accompanied higher mitochondrial NADH/NAD
ratio and higher fed-to-fasting phosphorylation of AMPKα and ACC. Taken together, our results provide evidence that BCAA supplementation, under conditions of insulin sensitivity, improved the feeding-to-fasting induction of hepatic lipid oxidation through changes in cellular redox, thus providing a favorable biochemical environment for flux through β-oxidation and lower de novo lipogenesis.
Branched-chain amino acids (BCAAs) have been shown to modulate lipid metabolic networks in various tissues, especially during insulin resistance. In this study we show that the dietary supplementation of BCAAs to normal, insulin-sensitive mice resulted in higher mitochondrial NADH:NAD
ratios and AMPK activation in the liver. This change in the cellular redox status provided an optimal metabolic milieu to increase fatty acid oxidation while keeping the rates of de novo lipogenesis lower in the BCAA-supplemented mice livers.
Of note, decreased Bifidobacterium is associated with Clostridium difficile infection (CDI), 6 whereas supplementation with Bifidobacterium is associated with reduced risk of developing CDI in ...humans. 7 Similarly, the abundance of Streptococcaceae is significantly increased in CDI, while Lachnospiraceae are reduced compared with healthy controls. 8 While studies have been somewhat inconsistent, a 2012 meta-analysis of 42 studies found that PPI use was associated with an increased risk for initial and recurrent CDI. 9 This led the US Food and Drug Administration to issue a drug safety warning in 2012 regarding this association. Funding: KRR is supported by the National Institutes of Health/National Institute on Aging San Antonio Claude D Pepper Older Americans Independence Center (1P30AG044271-01A1) Career Development (KL2) Program. Gut 2016; 65: 749-56. doi:10.1136/gutjnl-2015-310861 3 Reimer C , Bytzer P . Clinical trial: long-term use of proton pump inhibitors in primary care patients- a cross sectional analysis of 901 patients.
Blood-brain barrier (BBB) breakdown is a hallmark of many diseases of the central nervous system (CNS). Loss of BBB integrity in CNS diseases such as viral encephalitis results in the loss of ...nutrient/oxygen delivery, rapid infiltration of immune cells, and brain swelling that can exacerbate neuronal injury. Despite this, the cellular and molecular mechanisms that underlie BBB breakdown in viral encephalitis are incompletely understood. We undertook a comprehensive analysis of the cellular and molecular signaling events that induce BBB breakdown in an experimental model of virus-induced encephalitis in which neonatal mice are infected with reovirus (serotype 3 strain Abney). We show that BBB leakage during reovirus infection correlates with morphological changes in the vasculature, reductions in pericytes (BBB supporting cells), and disorganization of vascular junctions. Pathway analysis on RNA sequencing from brain endothelial cells identified the activation of interferon (IFN) signaling within the brain vasculature following reovirus infection. Our
and
studies show that type II IFN mediated by IFN-γ, a well known antiviral signal, is a major contributor to BBB leakage during reovirus infection. We show that IFN-γ reduces barrier properties in cultured brain endothelial cells through Rho kinase (ROCK)-mediated cytoskeletal contractions, resulting in junctional disorganization and cell-cell separations.
neutralization of IFN-γ during reovirus infection significantly improved BBB integrity, pericyte coverage, attenuated vascular ROCK activity, and junctional disorganization. Our work supports a model in which IFN-γ acts directly on the brain endothelium to induce BBB breakdown through a mechanism involving ROCK-induced junctional disorganization.
In an experimental viral encephalitis mouse model in which mice are infected with reovirus, we show that IFN-γ induces blood-brain barrier leakage. We show that IFN-γ promotes Rho kinase activity, resulting in actin cytoskeletal contractions in the brain endothelium that lead to vascular junctional disorganization and cell-cell separations. These studies now provide insight into a previously unknown mechanism for how blood-brain barrier breakdown occurs in viral encephalitis and implicates IFN-γ-Rho kinase activity as major contributor to this phenomenon. By identifying this mechanism of blood-brain barrier breakdown, we now provide potential therapeutic targets in treating patients with viral causes of encephalitis with the hope of limiting damage to the central nervous system.
Cross talk between branched‐chain amino acids (BCAAs; valine, leucine and isoleucine), mitochondrial metabolism and lipid accumulation have been shown to occur in several tissues, including skeletal ...muscle. In fact, defects in BCAA metabolism and their degradation networks coexist with defects in lipid metabolism in insulin resistant muscle. Here, we hypothesized that the relationship between BCAAs and lipid metabolism is due to the ability of BCAAs to modulate mitochondrial oxidative metabolism and lipid accumulation in the muscle. Mice (C57BL/6N) were randomly assigned to a low‐fat diet (LFD; 10% fat kcal), LFD supplemented with BCAAs (LFBA; 150% BCAA), high‐fat diet (HFD; 60% fat kcal) or HFD supplemented with BCAAs (HFBA; 150% BCAA) for 12 or 26 weeks (n = 8‐11 per group). Following the dietary treatments, leg muscle tissue were collected and flash frozen in liquid nitrogen, under feeding and overnight fasting conditions. Lipid accumulation was evaluated by analyzing muscle triglycerides, Oil‐Red‐O staining, and gene expression profiles. Mitochondrial metabolism and BCAA degradation were evaluated using a combination of gas‐chromatography/mass‐spectroscopy based targeted metabolomics and western blot analysis. Levels of BCAAs in the muscle showed significant correlations to their corresponding keto‐acids (p ≤ 0.01). However, supplementation of BCAAs did not affect the levels of mitochondrial tricarboxylic acid (TCA) cycle intermediates or amino acids in the muscle. Further, mitochondrial proteins involved in oxidative phosphorylation also remained similar between non‐supplemented and BCAA supplemented muscle. Muscle tissue from HFD mice had higher lipid accumulation (mg/g ± SEM) (LFD; 8.22 ± 0.91, HFD; 11.03 ± 1.08; p ≤ 0.05), compared to their LFD counterparts. Interestingly, BCAA supplementation for 12‐weeks along with the HFD blunted muscle lipid accumulation (LFBA; 8.62 ± 1.12, HFBA; 9.76 ± 0.75), which was also evidenced from Oil Red‐O staining of the muscle (p = 0.07). A similar lowering of lipid accumulation (p ≤ 0.05) was evident between the HFD vs. HFBA groups, following 26‐weeks on the diets, as quantified by Oil Red‐O staining. Further, the expression of genes involved in lipid accumulation/synthesis Srebp1c (p ≤ 0.05) and Acc1 (p ≤ 0.1) were lower in the 12‐week LFBA vs. their LF counterparts, under fed conditions. Taken together, our results show that BCAAs have the ability to blunt muscle lipid accumulation without altering mitochondrial oxidative metabolism in the muscle.
Encounters with the surveillance state during fieldwork are common, raising practical and intellectual challenges for qualitative research methods. Despite a number of studies on this topic, ...surveillance in illiberal and liberal contexts tend to be treated as separate problems. We provide a comparative case study that addresses the impacts of surveillance on sensitive research topics in the relatively weak state of Kyrgyzstan and the stronger state of China. Drawing on stories about negotiating the surveillance state with our research participants, we argue that (1) surveillance changes the relations of trust and rapport that are essential for knowledge production, (2) that it operates across unevenly positioned subjects, and (3) that the effects of surveillance on research outcomes do not substantially diverge across different state formations, such as China and Kyrgyzstan. The stories illustrate the intimate geopolitics of surveillance.
The composition of the gut microbiome reflects the overall health status of the host. In this study, stool samples representing the gut microbiomes from 6 gluten-sensitive (GS) captive juvenile ...rhesus macaques were compared with those from 6 healthy, age- and diet-matched peers. A total of 48 samples representing both groups were studied using V4 16S rRNA gene DNA analysis. Samples from GS macaques were further characterized based on type of diet administered: conventional monkey chow, i.e., wheat gluten-containing diet (GD), gluten-free diet (GFD), barley gluten-derived diet (BOMI) and reduced gluten barley-derived diet (RGB). It was hypothesized that the GD diet would lower the gut microbial diversity in GS macaques. This is the first report illustrating the reduction of gut microbial alpha-diversity (
< 0.05) following the consumption of dietary gluten in GS macaques. Selected bacterial families (e.g.,
and
) were enriched in GS macaques while
was enriched in healthy animals. Within several weeks after the replacement of the GD by the GFD diet, the composition (beta-diversity) of gut microbiome in GS macaques started to change (
= 0.011) towards that of a normal macaque. Significance for alpha-diversity however, was not reached by the day 70 when the feeding experiment ended. Several inflammation-associated microRNAs (miR-203, -204, -23a, -23b and -29b) were upregulated (
< 0.05) in jejunum of 4 biopsied GS macaques fed GD with predicted binding sites on 16S ribosomal RNA of
(accession number: NR_025911),
(NR_041364) and
(AJ297218) that were overrepresented in feces. Additionally, claudin-1, a validated tight junction protein target of miR-29b was significantly downregulated in jejunal epithelium of GS macaques. Taken together, we predict that with the introduction of effective treatments in future studies the diversity of gut microbiomes in GS macaques will approach those of healthy individuals. Further studies are needed to elucidate the regulatory pathways of inflammatory miRNAs in intestinal mucosa of GS macaques and to correlate their expression with gut dysbiosis.
This paper explores notions of (hetero)sexuality circulating in elementary school classrooms through an analysis of students' own talk and interactions. Data collected during a multi-site ethnography ...in a diverse set of elementary schools demonstrate that while curricular silences and teachers contribute to heteronormative classroom environments, children also take up and perpetuate heteronormative ideals in their own interactions both through explicitly anti-gay talk and by silencing of lesbian, gay, bisexual, transgender and queer (LGBTQ)-inclusive perspectives, thereby maintaining the heteronormativity of schools. Findings show (hetero)sexuality to be a constitutive part of classroom life, present even in the formal teaching/instructional time of elementary schools and even in the talk/activities of children themselves. Uninterrupted, these discourses intersect with the official curriculum and reify schools as places in which LGBTQ people/perspectives are not welcome or valued, creating social and academic effects for all students.
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