Inflammation-associated Alterations Research Articles

Metabolomics and network analysis uncovered profound inflammation-associated alterations in hepatitis B virus-related cirrhosis patients with early hepatocellular carcinoma

Patients with hepatitis B virus (HBV)-related liver cirrhosis (LC) are at high risk for hepatocellular carcinoma (HCC). Limitations in the early detection of HCC give rise to poor survival in this high-risk population. Here, we performed comprehensive metabolomics on health individuals and HBV-related LC patients with and without early HCC. Compared to non-HCC patients (N = 108) and health controls (N = 80), we found that patients with early HCC (N = 224) exhibited a specific plasma metabolome map dominated by lipid alterations, including lysophosphatidylcholines, lysophosphatidic acids and bile acids. Pathway and function network analyses indicated that these metabolite alterations were closely associated with inflammation responses. Using multivariate regression and machine learning approaches, we identified a five-metabolite combination that showed significant performances in differentiating early-HCC from non-HCC than α-fetoprotein (area under the curve values, 0.981 versus 0.613). At metabolomic levels, this work provides additional insights of metabolic dysfunction related to HCC progressions and demonstrates the plasma metabolites might be measured to identify early HCC in patients with HBV-related LC.

Eosinophilic esophagitis-associated epithelial remodeling may limit esophageal carcinogenesis.

Under homeostatic conditions, esophageal epithelium displays a proliferation/differentiation gradient that is generated as proliferative basal cells give rise to suprabasal cells then terminally differentiated superficial cells. This proliferation/differentiation gradient is often perturbed in esophageal pathologies. Basal cell hyperplasia may occur in patients with gastroesophageal reflux disease (GERD), a condition in which acid from the stomach enters the esophagus, or eosinophilic esophagitis (EoE), an emerging form of food allergy. While GERD is a primary risk factor for esophageal cancer, epidemiological data suggests that EoE patients do not develop esophageal cancer. In order to investigate the impact of EoE and esophageal cancer specifically on the cellular landscape of esophageal epithelium, we perform single cell RNA-sequencing in murine models of EoE and esophageal cancer, specifically esophageal squamous cell carcinoma (ESCC). We further evaluate modules of co-expressed genes in EoE- and ESCC-enriched epithelial cell clusters. Finally, we pair EoE and ESCC murine models to examine the functional relationship between these pathologies. In mice with either EoE or ESCC, we find expansion of cell populations as compared to normal esophageal epithelium. In mice with EoE, we detect distinct expansion of 4 suprabasal populations coupled with depletion of 2 basal populations. By contrast, mice with ESCC display unique expansion of 2 basal populations and 1 suprabasal population, as well as depletion of 2 suprabasal populations. Senescence, glucocorticoid receptor signaling, and granulocyte-macrophage colony-stimulating factor pathways are associated with EoE-enriched clusters while pathways associated with cell proliferation and metabolism are identified in ESCC-enriched clusters. Finally, our in vivo data demonstrate that exposure to EoE inflammation limits tumor burden of esophageal carcinogenesis. Our findings provide the first functional investigation of the relationship between EoE and esophageal cancer and suggest that esophageal epithelial remodeling events occurring in response to EoE inflammation may limit esophageal carcinogenesis. This investigation may have future implications for leveraging allergic inflammation-associated alterations in epithelial biology to prevent and/or treat esophageal cancer.

Biogeographic and disease-specific alterations in epidermal lipid composition and single-cell analysis of acral keratinocytes.

The epidermis is the outermost layer of skin. Here, we used targeted lipid profiling to characterize the biogeographic alterations of human epidermal lipids across 12 anatomically distinct body sites, and we used single-cell RNA-Seq to compare keratinocyte gene expression at acral and nonacral sites. We demonstrate that acral skin has low expression of EOS acyl-ceramides and the genes involved in their synthesis, as well as low expression of genes involved in filaggrin and keratin citrullination (PADI1 and PADI3) and corneodesmosome degradation, changes that are consistent with increased corneocyte retention. Several overarching principles governing epidermal lipid expression were also noted. For example, there was a strong negative correlation between the expression of 18-carbon and 22-carbon sphingoid base ceramides. Disease-specific alterations in epidermal lipid gene expression and their corresponding alterations to the epidermal lipidome were characterized. Lipid biomarkers with diagnostic utility for inflammatory and precancerous conditions were identified, and a 2-analyte diagnostic model of psoriasis was constructed using a step-forward algorithm. Finally, gene coexpression analysis revealed a strong connection between lipid and immune gene expression. This work highlights (a) mechanisms by which the epidermis is uniquely adapted for the specific environmental insults encountered at different body surfaces and (b) how inflammation-associated alterations in gene expression affect the epidermal lipidome.

Monitoring and Modulating Inflammation-Associated Alterations in Synaptic Plasticity: Role of Brain Stimulation and the Blood-Brain Interface.

Inflammation of the central nervous system can be triggered by endogenous and exogenous stimuli such as local or systemic infection, trauma, and stroke. In addition to neurodegeneration and cell death, alterations in physiological brain functions are often associated with neuroinflammation. Robust experimental evidence has demonstrated that inflammatory cytokines affect the ability of neurons to express plasticity. It has been well-established that inflammation-associated alterations in synaptic plasticity contribute to the development of neuropsychiatric symptoms. Nevertheless, diagnostic approaches and interventional strategies to restore inflammatory deficits in synaptic plasticity are limited. Here, we review recent findings on inflammation-associated alterations in synaptic plasticity and the potential role of the blood–brain interface, i.e., the blood–brain barrier, in modulating synaptic plasticity. Based on recent findings indicating that brain stimulation promotes plasticity and modulates vascular function, we argue that clinically employed non-invasive brain stimulation techniques, such as transcranial magnetic stimulation, could be used for monitoring and modulating inflammation-induced alterations in synaptic plasticity.

Interleukin 10 Restores Lipopolysaccharide-Induced Alterations in Synaptic Plasticity Probed by Repetitive Magnetic Stimulation.

Systemic inflammation is associated with alterations in complex brain functions such as learning and memory. However, diagnostic approaches to functionally assess and quantify inflammation-associated alterations in synaptic plasticity are not well-established. In previous work, we demonstrated that bacterial lipopolysaccharide (LPS)-induced systemic inflammation alters the ability of hippocampal neurons to express synaptic plasticity, i.e., the long-term potentiation (LTP) of excitatory neurotransmission. Here, we tested whether synaptic plasticity induced by repetitive magnetic stimulation (rMS), a non-invasive brain stimulation technique used in clinical practice, is affected by LPS-induced inflammation. Specifically, we explored brain tissue cultures to learn more about the direct effects of LPS on neural tissue, and we tested for the plasticity-restoring effects of the anti-inflammatory cytokine interleukin 10 (IL10). As shown previously, 10 Hz repetitive magnetic stimulation (rMS) of organotypic entorhino-hippocampal tissue cultures induced a robust increase in excitatory neurotransmission onto CA1 pyramidal neurons. Furthermore, LPS-treated tissue cultures did not express rMS-induced synaptic plasticity. Live-cell microscopy in tissue cultures prepared from a novel transgenic reporter mouse line [C57BL/6-Tg(TNFa-eGFP)] confirms that ex vivo LPS administration triggers microglial tumor necrosis factor alpha (TNFα) expression, which is ameliorated in the presence of IL10. Consistent with this observation, IL10 hampers the LPS-induced increase in TNFα, IL6, IL1β, and IFNγ and restores the ability of neurons to express rMS-induced synaptic plasticity in the presence of LPS. These findings establish organotypic tissue cultures as a suitable model for studying inflammation-induced alterations in synaptic plasticity, thus providing a biological basis for the diagnostic use of transcranial magnetic stimulation in the context of brain inflammation.

In vivo analysis of mucosal lipids reveals histological disease activity in ulcerative colitis using endoscope-coupled Raman spectroscopy.

The goal of this study is to evaluate endoscopic Raman spectroscopy as a noninvasive technique to determine histological inflammatory status of colitis. Colon mucosal composition was investigated in vivo from patients with ulcerative colitis (UC) and from age- and body mass index (BMI) matched controls using endoscope-coupled Raman spectroscopy. The results were co-registered with histological assessment of inflammatory status at the same locations. Substantial decreases (50-60%) in the content of phosphotidylcholines (PCs) and total lipids were observed in inflamed colon tissue (histology grade 1, 2 and 3) compared to those from the quiescent (histology grade 0) and from the controls. No significant difference was observed in lipids or PC contents between control and grade 0, or among grades 1 - 3. The degree of lipid unsaturation increased in the inflamed tissue regardless of disease severity. The inflammation-associated alterations in lipids and PC are observed independent of BMI or the anatomical locations for data collection. Multivariate analysis using support vector machine (SVM) algorithm classified the spectra of the controls or the inactive colitis from those of inflamed tissue with a sensitivity of 83.5% and 97.1% respectively. Our results showed that mucosal lipid content is related to the microscopic disease activity, and thus could serve as a valuable spectral marker to differentiate active colitis from the quiescent.

Inflammation-associated alterations to the intestinal microbiota reduce colonization resistance against non-typhoidal Salmonella during concurrent malaria parasite infection.

Childhood malaria is a risk factor for disseminated infections with non-typhoidal Salmonella (NTS) in sub-Saharan Africa. While hemolytic anemia and an altered cytokine environment have been implicated in increased susceptibility to NTS, it is not known whether malaria affects resistance to intestinal colonization with NTS. To address this question, we utilized a murine model of co-infection. Infection of mice with Plasmodium yoelii elicited infiltration of inflammatory macrophages and T cells into the intestinal mucosa and increased expression of inflammatory cytokines. These mucosal responses were also observed in germ-free mice, showing that they are independent of the resident microbiota. Remarkably, P. yoelii infection reduced colonization resistance of mice against S. enterica serotype Typhimurium. Further, 16S rRNA sequence analysis of the intestinal microbiota revealed marked changes in the community structure. Shifts in the microbiota increased susceptibility to intestinal colonization by S. Typhimurium, as demonstrated by microbiota reconstitution of germ-free mice. These results show that P. yoelii infection, via alterations to the microbial community in the intestine, decreases resistance to intestinal colonization with NTS. Further they raise the possibility that decreased colonization resistance may synergize with effects of malaria on systemic immunity to increase susceptibility to disseminated NTS infections.

IL-1β reciprocally regulates chemokine and insulin secretion in pancreatic β-cells via NF-κB.

Proinflammatory cytokines impact islet β-cell mass and function by altering the transcriptional activity within pancreatic β-cells, producing increases in intracellular nitric oxide abundance and the synthesis and secretion of immunomodulatory proteins such as chemokines. Herein, we report that IL-1β, a major mediator of inflammatory responses associated with diabetes development, coordinately and reciprocally regulates chemokine and insulin secretion. We discovered that NF-κB controls the increase in chemokine transcription and secretion as well as the decrease in both insulin secretion and proliferation in response to IL-1β. Nitric oxide production, which is markedly elevated in pancreatic β-cells exposed to IL-1β, is a negative regulator of both glucose-stimulated insulin secretion and glucose-induced increases in intracellular calcium levels. By contrast, the IL-1β-mediated production of the chemokines CCL2 and CCL20 was not influenced by either nitric oxide levels or glucose concentration. Instead, the synthesis and secretion of CCL2 and CCL20 in response to IL-1β were dependent on NF-κB transcriptional activity. We conclude that IL-1β-induced transcriptional reprogramming via NF-κB reciprocally regulates chemokine and insulin secretion while also negatively regulating β-cell proliferation. These findings are consistent with NF-κB as a major regulatory node controlling inflammation-associated alterations in islet β-cell function and mass.

Aberrant maternal inflammation as a cause of pregnancy complications: A potential therapeutic target?

Pre-eclampsia (PE), fetal growth restriction (FGR), pre-term labour and fetal death are common complications of pregnancy often associated with abnormal maternal inflammation. Though the precise causes of these complications remain obscure, altered maternal blood flow to the placenta is an underlying hallmark, especially with respect to the pathogenesis of PE, FGR and fetal demise. Furthermore, deficient trophoblast-mediated spiral artery remodelling is often cited as the primary cause of impaired utero-placental perfusion. Considerably less attention has been directed towards investigating other factors, including maternal vasoconstriction or hemostatic alterations, as contributors to poor utero-placental perfusion. This review provides a rationale for investigating the role of abnormal maternal inflammation in the pathophysiology of pregnancy complications including PE, FGR and fetal demise. In particular, the association between aberrant maternal inflammation and inadequate utero-placental perfusion is considered in the context of inflammation-associated alterations in maternal hemostasis and vasoconstriction. Finally, the role of aberrant maternal inflammation as a cause of local oxidative/nitrosative stress is examined and the possibility of targeting deficient nitric oxide signalling as a therapeutic intervention for the treatment of inflammation-associated pregnancy complications is discussed.

Polyphenol Supplementation Improves Cardiomyocyte Recovery After Marathon Running

PURPOSE: The liberation and increase in concentration of cardiac troponin (cTn) during and after strenuous exercise are known phenomena. Polyphenols have anti-inflammatory and anti-oxidative effects that may counteract cTn release and inflammation-associated alterations of the cardiovascular system. Therefore, we investigated, whether supplementation with polyphenols has cardiomyocyte protective effects in marathon runners competing in the Munich Marathon. METHODS: We examined the effects of polyphenol supplementation in 277 male marathon runners (age 42±9yrs.) in a randomized, double-blind and placebo-controlled manner with regard to levels of cTnT and inflammatory biomarker levels before a marathon race, and immediately, 24 and 72hrs afterwards. Per-protocol (PP) population was defined as all participants who finished the race successfully and ingested ≥ 1L (≥ 326mg gallic acid equivalents (GAE) per 100g) of the supplementation per day. 149 participants (70 verum group (V=polyphenol supplementation), 79 placebo group (PL=identically with V except for polyphenols)) were in PP population. RESULTS: We observed no significant difference between V and PL regarding cTnT concentration immediately post-race (median [IQR]: V: 33.7 [19.2-54.6]ng/L vs. PL: 37.0 [21.0-51.0]ng/L, p=0.85). However, there was a significantly larger decrease in cTnT 24 hrs post-race in V (4.2 [2.8-6.0]-fold) compared to PL (3.4 [2.3-5.0]-fold) (p=0.02), resulting in lower cTnT levels 72 hrs post-race (24h-post: V: 8.0 [3.1-15.4]ng/L vs. PL: 11.0 [6.2-16.1]ng/L, p=0.08; 72h-post: V: 3.0 [3.0-6.3]ng/L vs. PL: 5.7 [3.0-8.7]ng/L, p=0.04). CONCLUSIONS: Supplementation with a polyphenolic mixture was linked to enhanced cardiomyocyte recovery after prolonged and strenuous exercise.

171. The neurocircuitry of increased inflammation in depression: Preliminary results

Evidence suggests a cause and effect relationship between inflammatory cytokines and behavioral symptoms relevant to a number of psychiatric illnesses. Previous neuroimaging studies have demonstrated that administration of inflammatory stimuli or cytokines changes activity of basal ganglia nuclei to mediate depressive symptoms, effects that may be mediated by decreased striatal dopamine. Whether the effects of inflammation extend beyond the basal ganglia to other brain regions to contribute to specific behavioral symptoms is unknown. This study examined whether increased inflammation in depression affects functional connectivity between the basal ganglia (striatum) and other brain regions to mediate depressive and neurocognitive symptoms. Wakeful resting-state fMRI pilot data were obtained from 17 currently depressed patients with low versus high inflammation (C-reactive protein ⩽ 3 versus >3 mg/L). Seed-to-whole brain correlations were computed and compared between groups using four predefined striatal seeds. Depressed patients with high inflammation exhibited attenuated functional connectivity between three striatal seeds and thirteen cortical or subcortical brain regions. Of these thirteen significant relationships, inflammation-related compromised connectivity between ventral striatum and both anterior cingulate cortex and amygdala correlated with symptoms of anhedonia and anxiety, whereas decreased connectivity between dorsal striatum and prefrontal cortex was associated with decreased psychomotor performance. Understanding inflammation-associated alterations in neurocircuitry that mediate specific depressive behaviors is important for identifying strategies to diagnose and treat behavioral symptoms in patients with increased inflammation.

IL-6 and IL-18 in Blood May Discriminate Cirrhotic Patients With and Without Minimal Hepatic Encephalopathy

Patients with liver cirrhosis may present minimal hepatic encephalopathy (MHE) that can be unveiled using specific neuropsychologic examination. Evaluation of MHE in cirrhotic patients might have prognostic value. The psychometric HE score (PHES) has been recommended as the "gold standard" in the diagnosis of MHE. It has been proposed that critical flicker frequency (CFF) analysis would be useful for easier detection of MHE. It would also be useful to have some peripheral parameter that could reflect the presence of MHE. It has been recently proposed that inflammation-associated alterations and hyperammonemia may cooperate in the induction of hepatic encephalopathy. The aim of the present work was to assess whether there is a correlation between the alterations in parameters reflecting inflammation, hyperammonemia, and the presence of MHE. We have studied in 55 patients with liver cirrhosis and 26 controls the performance in the PHES battery and the CFF, ammonia, and some interleukins (ILs) as inflammatory markers. IL-6 and IL-18 were significantly higher (2.5-fold and 2.2-fold, respectively) in patients with MHE than in those without MHE. There were significant correlations between IL-6 or IL-18 levels and PHES score and CFF. Moreover, all patients with MHE had IL-6 levels higher than 11 ng/mL, whereas all patients without MHE had IL-6 levels lower than 11 ng/mL. Inflammatory alterations related with IL-6 and IL-18 may contribute to MHE. Serum concentration of IL-6 and IL-18 may be useful to discriminate cirrhotic patients with and without MHE.

Neuroinflammation contributes to hypokinesia in rats with hepatic encephalopathy: Ibuprofen restores its motor activity

Patients with hepatic encephalopathy show altered motor function, psychomotor slowing, and hypokinesia, which are reproduced in rats with portacaval shunts (PCS). Increased extracellular glutamate in substantia nigra pars reticulata (SNr) is responsible for hypokinesia in PCS rats. The mechanisms by which liver failure leads to increased extracellular glutamate in SNr remain unclear. Inflammation seems to act synergistically with hyperammonemia to induce neurological alterations in hepatic encephalopathy. It is therefore possible that inflammation-associated alterations may contribute to motor alterations in hepatic encephalopathy. The aim of this work was to assess whether treatment with an antiinflammatory, ibuprofen, is able to normalize extracellular glutamate in SNr and/or to improve hypokinesia in PCS rats. The amounts of the glutamate transporters GLT-1 and EAAC-1 are reduced by 26% and 32%, respectively, in SNr of PCS rats. This reduction is associated with a tenfold increase in extracellular glutamate in SNr and a reduction in motor activity. Chronic treatment with 30 mg/kg ibuprofen completely normalizes the amount of GLT-1 and EAAC-1 and significantly reduces (by 53%) extracellular glutamate in SNr of PCS rats. Moreover, ibuprofen, at 15 or 30 (but not at 5) mg/kg/day, completely eliminates hypokinesia, restoring normal motor activity. This supports the idea that inflammation is a main contributor to the induction of hypokinesia in hepatic encephalopathy. Moreover, these data point to the possible therapeutic utility of decreasing inflammation, by safe procedures, in the treatment of the motor deficits in patients with hepatic encephalopathy.

Inflammation and hepatic encephalopathy: Ibuprofen restores learning ability in rats with portacaval shunts

One of the neurological alterations in patients with minimal or overt hepatic encephalopathy is cognitive impairment. This impairment is reproduced in rats with chronic liver failure due to portacaval shunt (PCS). These rats show decreased ability to learn a conditional discrimination task in a Y-maze, likely due to reduced function of the glutamate-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway in brain. It has been proposed that inflammation exacerbates the neuropsychological alterations induced by hyperammonemia, suggesting that inflammation-associated alterations may contribute to cognitive impairment in hepatic encephalopathy. This study assessed whether treatment with an anti-inflammatory drug, ibuprofen, is able to restore the function of the glutamate-NO-cGMP pathway in cerebral cortex in brain in vivo and/or learning ability in PCS rats. We show that PCS rats have increased levels of interleukin-6 and increased activities of cyclooxygenase and of inducible NO synthase in cerebral cortex, indicating the presence of inflammation. Chronic treatment with ibuprofen normalizes cyclooxygenase and inducible NO synthase activities but not interleukin-6 levels. Moreover, ibuprofen normalizes the function of the glutamate-NO-cGMP pathway in cerebral cortex in vivo and completely restores the ability of rats with chronic liver failure to learn the Y-maze task. This supports that inflammation contributes to the cognitive impairment in hepatic encephalopathy. the results reported point to the possible therapeutic utility of decreasing inflammation in the treatment of the cognitive deficits in patients with minimal or overt hepatic encephalopathy.

Leukocyte Changes Associated with Acute Inflammation in Chickens

Leukocyte changes in chickens with turpentine-induced inflammation were investigated sequentially at 0, 6, 12, and 24 hours and at 2, 3, 4, 7, and 14 days. During acute inflammation, significant leukocytosis and heterophilia developed by 6 hours and persisted through 7 days. The peak mean heterophil and leukocyte counts occurred at 12 hours and 3 days, respectively. Left shifts were present at 12 and 24 hours as detected by 100-cell leukocyte differential counts. Heterophil mean nuclear scores documented nuclear hyposegmentation (left shift) during early inflammation and nuclear hypersegmentation (right shift) during convalescence. Mean monocyte and lymphocyte counts peaked at 2 and 3 days, respectively. Basophil and eosinophil counts were erratic. Toxic changes of heterophils were most apparent during intense left shifts and consisted of cell swelling, degranulation, cytoplasmic vacuolation, and cytoplasmic basophilia. Cytoplasmic basophilia was the last aspect of toxic change to resolve. Ultrastructurally, toxic heterophils had intracellular edema, dissolution of granules, retention of ribosomes, nuclear membrane blebs, and decreased heterochromatin density. All inflammation-associated alterations in cell counts and morphology returned to baseline values and appearance by 14 days after turpentine administration.