Effects of CRAMP on the gut-brain axis in experimental sepsis.

The collaboration between the microbiota, mucosa, and intestinal epithelium is crucial for defending against pathogens and external antigens. Dysbiosis disrupts this balance, allowing pathogens to thrive and potentially enter the bloodstream, triggering immune dysregulation and potentially leading to sepsis. Antimicrobial peptides like LL-37 and CRAMP are pivotal in innate immune defense. Their expression varies with infection severity, exhibiting a dual pro- and anti-inflammatory response. Understanding this dynamic is key to comprehending sepsis progression. In our study, we examined the inflammatory response in CRAMP knockout mice post-cecal ligation and puncture (CLP). We assessed its impact on brain tissue damage and the intestinal microbiota. Our findings revealed higher gene expression of S100A8 and S100A9 in the prefrontal cortex of wild-type mice versus CRAMP-knockout mice. This trend was consistent in the hippocampus and cerebellum, although protein concentrations remained constant. Notably, there was a notable increase in Escherichia coli, Lactobacillus spp., and Enterococcus faecalis populations in wild-type mice 24 h post-CLP compared to the CRAMP-deficient group. These results align with our previous data suggesting that the absence of CRAMP may confer protection in this sepsis model.

Cardiovascular risk in women with nonclassical congenital adrenal hyperplasia.

CONTEXT: The outcomes related to cardiovascular risk (CVR) in patients with nonclassical form of congenital adrenal hyperplasia (NCAH) are unknown, especially those related to therapeutic options, including low doses of glucocorticoids (GCs) or oral contraceptive pills. OBJECTIVES: to analyze CVR by markers of atherosclerosis in females with nonclassical form according to therapeutic options. DESIGN AND SETTING: a cross-sectional study at a tertiary center. PATIENTS AND METHODS: Forty-seven females with NCAH (33.4 ± 10 years) were subdivided into: G1 (n = 28) treated with dexamethasone (0.14 ± 0.05 mg/m2/day); G2 (n = 19) with oral contraceptive pills; and G3 (30 matched controls). CVR was analyzed through serum lipids, HOMA-IR, inflammatory cytokines levels and quantitative image evaluations (pulse wave velocity-PWV, endothelial function by flow mediated dilatation-FMD, carotid intima media thickness-CIMT and visceral fat-VAT by abdominal tomography. RESULTS: There were no statistically significant differences in BMI, HOMA-IR, HDL-cholesterol, or triglyceride levels among groups (p > 0.05). Serum interleukin-6 levels ​​were higher in G1 than in G2 (p = 0.048), and interleukin-8 levels were higher in G1 than in G2/3 (p = 0.008). There were no statistically significant differences in VAT, PWV, FMD or CIMT among groups (p > 0.05). In multivariable regression analysis, there was no statistically significant association between glucocorticoid dose and evaluated outcomes. CONCLUSION: Adult females with NCAH did not show increased CVR using methodologies for detection of precocious atherosclerosis. Although patients receiving dexamethasone therapy had increased IL-6 and 8 levels, these data were not associated with radiological markers of atherosclerosis. Our cohort was composed of young adults and should be reevaluated in a long-term follow-up.

Short-term Obesity Worsens Heart Inflammation and Disrupts Mitochondrial Biogenesis and Function in an Experimental Model of Endotoxemia.

Cardiomyopathy is a well-known complication of sepsis that may deteriorate when accompanied by obesity. To test this hypothesis we fed C57black/6 male mice for 6 week with a high fat diet (60% energy) and submitted them to endotoxemic shock using E. coli LPS (10 mg/kg). Inflammatory markers (cytokines and adhesion molecules) were determined in plasma and heart tissue, as well as heart mitochondrial biogenesis and function. Obesity markedly shortened the survival rate of mouse after LPS injection and induced a persistent systemic inflammation since TNFα, IL-1ß, IL-6 and resistin plasma levels were higher 24 h after LPS injection. Heart tissue inflammation was significantly higher in obese mice, as detected by elevated mRNA expression of pro-inflammatory cytokines (IL-1ß, IL-6 and TNFα). Obese animals presented reduced maximum respiratory rate after LPS injection, however fatty acid oxidation increased in both groups. LPS decreased mitochondrial DNA content and mitochondria biogenesis factors, such as PGC1α and PGC1ß, in both groups, while NRF1 expression was significantly stimulated in obese mice hearts. Mitochondrial fusion/fission balance was only altered by obesity, with no influence of endotoxemia. Obesity accelerated endotoxemia death rate due to higher systemic inflammation and decreased heart mitochondrial respiratory capacity.

Banana green peels extract protects against nonalcoholic fatty liver disease in high-fat-fed mice through modulation of lipid metabolism and inflammation.

We investigate the effect of the banana green peels extract (BPE) as a preventive treatment against NAFLD in high-fat diet fed mice. Mice received daily doses of 100 or 250 mg/kg of BPE for 12 weeks along with the high-fat diet. BPE reduced weight gain (p < .0001), adipose tissue hypertrophy (p < .0001), and improved glucose homeostasis (p < .0001). Plasma levels of glucose-dependent insulinotropic polypeptide, triglycerides, total cholesterol, LDL-cholesterol, non-esterified fatty acids, aspartate and alanine transaminase, leptin, and resistin were decreased in BPE treated mice (p < .05). BPE effects on lipid metabolism were associated with decreased gene expression of lipogenic enzymes and increased expression of enzymes related to fatty acid and cholesterol degradation (p < .05). Plasma and liver bile acid (BA) profiles were modulated by BPE, with positive correlations between specific BA and UCP-1, CPT-1 and PGC-1ß expression in brown adipose tissue (p < .05). BPE reduced hepatic steatosis and inflammation, possibly due to reduced p65 NF-κB nuclear translocation (p < .05) and modulation of oxidative stress (p < .05). These data indicate that BPE is a source of phytochemical compounds with promising effects toward the prevention of metabolic disorders associated with obesity.

Endothelial injury in COVID-19 and septic patients.

Systemic inflammatory response, as observed in sepsis and severe COVID-19, may lead to endothelial damage. Therefore, we aim to compare the extent of endothelial injury and its relationship to inflammation in both diseases. We included patients diagnosed with sepsis (SEPSIS group, n = 21), mild COVID-19 (MILD group, n = 31), and severe COVID-19 (SEVERE group, n = 24). Clinical and routine laboratory data were obtained, circulating cytokines (INF-γ, TNF-α, and IL-10) and endothelial injury markers (E-Selectin, Tissue Factor (TF) and von Willebrand factor (vWF)) were measured. Compared to the SEPSIS group, patients with severe COVID-19 present similar clinical and laboratory data, except for lower circulating IL-10 and E-Selectin levels. Compared to the MILD group, patients in the SEVERE group showed higher levels of TNF-α, IL-10, and TF. There was no clear relationship between cytokines and endothelial injury markers among the three studied groups; however, in SEVERE COVID-19 patients, there is a positive relationship between INF-γ with TF and a negative relationship between IL-10 and vWF. In conclusion, COVID-19 and septic patients have a similar pattern of cytokines and endothelial dysfunction markers. These findings highlight the importance of endothelium dysfunction in COVID-19 and suggest that endothelium should be better evaluated as a therapeutic target for the disease.

Guanosine Neuroprotection of Presynaptic Mitochondrial Calcium Homeostasis in a Mouse Study with Amyloid-ß Oligomers.

Amyloid-ß oligomers (AßOs) toxicity causes mitochondrial dysfunction, leading to synaptic failure in Alzheimer's disease (AD). Considering presynaptic high energy demand and tight Ca2+ regulation, impairment of mitochondrial function can lead to deteriorated neural activity and cell death. In this study, an AD mouse model induced by ICV (intracerebroventricular) injection of AßOs was used to investigate the toxicity of AßOs on presynaptic function. As a therapeutic approach, GUO (guanosine) was given by oral route to evaluate the neuroprotective effects on this AD model. Following 24 h and 48 h from the model induction, behavioral tasks and biochemical analyses were performed, respectively. AßOs impaired object recognition (OR) short-term memory and reduced glutamate uptake and oxidation in the hippocampus. Moreover, AßOs decreased spare respiratory capacity, reduced ATP levels, impaired Ca2+ handling, and caused mitochondrial swelling in hippocampal synaptosomes. Guanosine crossed the BBB, recovered OR short-term memory, reestablished glutamate uptake, recovered mitochondrial Ca2+ homeostasis, and partially prevented mitochondrial swelling. Therefore, this endogenous purine presented a neuroprotective effect on presynaptic mitochondria and should be considered for further studies in AD models.

The PARP inhibitor olaparib exerts beneficial effects in mice subjected to cecal ligature and puncture and in cells subjected to oxidative stress without impairing DNA integrity: A potential opportunity for repurposing a clinically used oncological drug for the experimental therapy of sepsis.

Poly(ADP-ribose) polymerase (PARP) is involved in the pathogenesis of cell dysfunction, inflammation and organ failure during septic shock. The goal of the current study was to investigate the efficacy and safety of the clinically approved PARP inhibitor olaparib in experimental models of oxidative stress in vitro and in sepsis in vivo. In mice subjected to cecal ligation and puncture (CLP) organ injury markers, circulating and splenic immune cell distributions, circulating mediators, DNA integrity and survival was measured. In U937 cells subjected to oxidative stress, cellular bioenergetics, viability and DNA integrity were measured. Olaparib was used to inhibit PARP. The results show that in adult male mice subjected to CLP, olaparib (1-10 mg/kg i.p.) improved multiorgan dysfunction. Olaparib treatment reduced the degree of bacterial CFUs. Olaparib attenuated the increases in the levels of several circulating mediators in the plasma. In the spleen, the number of CD4+ and CD8+ lymphocytes were reduced in response to CLP; this reduction was inhibited by olaparib treatment. Treg but not Th17 lymphocytes increased in response to CLP; these cell populations were reduced in sepsis when the animals received olaparib. The Th17/Treg ratio was lower in CLP-olaparib group than in the CLP control group. Analysis of miRNA expression identified a multitude of changes in spleen and circulating white blood cell miRNA levels after CLP; olaparib treatment selectively modulated these responses. Olaparib extended the survival rate of mice subjected to CLP. In contrast to males, in female mice olaparib did not have significant protective effects in CLP. In aged mice olaparib exerted beneficial effects that were less pronounced than the effects obtained in young adult males. In in vitro experiments in U937 cells subjected to oxidative stress, olaparib (1-100 µM) inhibited PARP activity, protected against the loss of cell viability, preserved NAD+ levels and improved cellular bioenergetics. In none of the in vivo or in vitro experiments did we observe any adverse effects of olaparib on nuclear or mitochondrial DNA integrity. In conclusion, olaparib improves organ function and extends survival in septic shock. Repurposing and eventual clinical introduction of this clinically approved PARP inhibitor may be warranted for the experimental therapy of septic shock.

Chemical composition and cytotoxic screening of Musa cavendish green peels extract: Antiproliferative activity by activation of different cellular death types.

Musa cavendish, commonly known as banana, is a fruit with nutritional and therapeutic properties. We investigated the chemical composition and in vitro cytotoxic effect of M. cavendish green peel extract (MHE) on cancer cells for the first time. The compounds characterization was performed by HPLC-UV/Vis and FIA-ESI-IT-MSn. We investigated in vitro cytotoxic effect of Musa cavendish green peels extract (MHE) in HepG2, A-375, MCF-7 and Caco-2 cancer cells. We evaluated the effect of MHE on proliferation of different cell lines through apoptosis, necrosis, mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) content determination. We identified 12 compounds from different classes in the extract, including derivatives of phenolic acids, aglycone flavonoids, glycoside flavonoids and catecholamines. Our results indicate that MHE exerts, after 48 h treatment, an accentuated antiproliferative effect from the dose of 100 µg/mL in all cell lines tested. In HepG2 cells, these effects were related to the induction of cell death, both necrotic and apoptotic, and remarkable changes in cell morphology. Depolarization of MMP and high ROS content were also observed in the cells in a dose-dependent manner. Our results show that MHE may be used as a source of new drugs with anticancer activity.

Syzygium cumini Leaf Extract Reverts Hypertriglyceridemia via Downregulation of the Hepatic XBP-1s/PDI/MTP Axis in Monosodium L-Glutamate-Induced Obese Rats.

Syzygium cumini is used worldwide for the treatment of metabolic syndrome-associated outcomes. Previously, we described the antihypertriglyceridemic effect of the hydroethanolic extract of S. cumini leaf (HESc) in monosodium L-glutamate- (MSG-) induced obese rats. This study sought to investigate the molecular mechanisms underlying the antihypertriglyceridemic effect of HESc in MSG-obese rats. Newborn male Wistar rats were injected subcutaneously with MSG (4.0 g/kg/day, obese group) or saline 1.25% (1.0 mL/kg/day, lean group), from 2nd through 10th postnatal day. At 8 weeks old, obese rats started to be orally treated with HESc (0.5 or 1.0 g/kg/day, n = 7) or saline 0.9% (1 mL/kg/day, n = 7). Lean rats received saline solution (1 mL/kg/day, n = 7). Upon 8-week treatment, animals were euthanized for blood and tissue collection. Another set of adult nonobese Wistar rats was used for the assessment of HESc acute effects on Triton WR1339-induced hypertriglyceridemia. HESc reduced weight gain, as well as adipose tissue fat pads, without altering food intake of obese rats. HESc restored fasting serum glucose, triglycerides, total cholesterol, and free fatty acids, as well as insulin sensitivity, to levels similar to lean rats. Additionally, HESc halved the triglyceride content into very low-density lipoprotein particles, as well as healed liver steatosis, in obese rats. Hepatic protein expression of the endoplasmic reticulum chaperone GRP94 was decreased by HESc, which also downregulated the hepatic triglyceride secretion pathway by reducing the splicing of X-box binding protein 1 (XBP-1s), as well as protein disulfide isomerase (PDI) and microsomal triglyceride transfer protein (MTP) translational levels. This action was further corroborated by the acute inhibitory effect of HESc on triglyceride accumulation on Triton WR1339-treated rats. Our data support the downregulation of the XBP-1s/PDI/MTP axis in the liver of MSG-obese rats as a novel feasible mechanism for the antihypertriglyceridemic effect promoted by the polyphenolic phytocomplex present in S. cumini leaf.

The mechanisms involved in the increased adiposity induced by interruption of regular physical exercise practice.

AIMS: We investigated the effects of physical detraining on lipogenesis/lipolysis and cellularity (apoptosis/adipogenesis) in rat subcutaneous (inguinal; SC) and visceral (retroperitoneal; RP) white adipose depots. MAIN METHODS: Three groups of male Wistar rats (6-wk old) were studied: (1) (T) trained for 12 weeks; (2) (D) trained for 8 weeks and detrained for 4 weeks; and (3) (S) age-matched sedentary. Training consisted of treadmill running sessions (1 h/day, 5 days/week, 50-60% maximal race capacity). KEY FINDINGS: Physical detraining increased glucose oxidation, lipogenesis, and adipocyte size in the SC and RP depots. The number of apoptotic SC adipocytes was reduced by 53% in the T (p < 0.0001) and by 43% in the D (p < 0.001) as compared with S. RP adipocyte apoptosis in the T and D was 9.48% and 10.9% greater compared to the S, respectively (p < 0.05). In the SC stromal vascular fraction (SVF) of D rats, adiponectin, sterol regulatory element binding protein (SREBP)-1c, Peroxisome proliferator-activated receptor gamma (PPARγ), and Perilipin A mRNA expressions were more pronounced than S group, suggesting a more intense adipogenesis. This putative adipogenic effect was not observed in the RP depot. The physical detraining promoted rapid increase in the SC and RP depots however not through the same mechanisms. SIGNIFICANCE: Physical detraining induced fat cell hypertrophy (increase of lipogenesis) in both SC and RP whereas hyperplasia (increase of adipogenesis and reduction of apoptosis) was found in SC only. These results indicate the mechanism associated with obesogenic effects of detraining varies with the fat depot.

High-fat diet inhibits PGC-1α suppressive effect on NFκB signaling in hepatocytes.

PURPOSE: The peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) regulates the expression of genes implicated in fatty acid oxidation and oxidative phosphorylation. Its role in liver steatosis is well established, since mice with liver-specific deletion of PGC-1α exhibit lipid accumulation and high-fat diet reduces hepatic PGC-1α expression in mice. In this study, we investigated the role of PGC-1α in the inflammatory changes observed in steatohepatitis induced by high-fat diet. METHODS: C57black/6 mice were fed a high-fat diet containing 30% fat for 10 weeks. After euthanasia, liver morphology was examined by HE staining and inflammation was determined by IL-6, TNF-α, and IL-1ß quantification. Liver gene expression of PGC-1 isoforms was evaluated by real-time PCR and p65 NFκB nuclear translocation by Western blotting. HepG2 cells were treated with linoleic acid overload for 72 h to create an in vitro model of steatohepatitis. RNA interference (RNAi) was used to evaluate the involvement of PGC-1α on inflammatory mediators' production by hepatocytes. RESULTS: The high-fat diet led to a state of nonalcoholic steatohepatitis, associated with increased deposits of intra-abdominal fat, hyperglycemia and hyperlipidemia. Mice liver also exhibited increased proinflammatory cytokines' levels, decreased PGC-1α expression, and marked increase in p65 NFκB nuclear translocation. Linoleic acid treated cells also presented increased expression of proinflammatory cytokines and decreased PGC-1α expression. The knockdown of PGC-1α content caused an increase in IL-6 expression and release via enhanced IκBα phosphorylation and subsequent increase of p65 NFκB nuclear translocation. CONCLUSION: High-fat diet induces liver inflammation by inhibiting PGC-1α expression and its suppressive effect in NFκB pathway.

Cathelicidin-deficient mice exhibit increased survival and upregulation of key inflammatory response genes following cecal ligation and puncture.

Antimicrobial peptides possess a myriad of molecular properties including bacterial killing and the regulation of many aspects of innate immunity. Cathelicidins are a group of antimicrobial peptides widely investigated by the scientific community. Many studies have focused on the bactericidal and pro-inflammatory roles of cathelicidins. Because the role of endogenous cathelicidin expression remains obscure in deep-seated systemic infections, we induced sepsis in cathelicidin knockout and wild-type (WT) mice by cecal ligation and puncture, performing transcriptome screening by DNA microarray in conjunction with other immunologic assays. Cathelicidin-deficient mice showed increased survival compared to WT mice in this established experimental model of polymicrobial sepsis, in association with upregulation of certain key inflammatory response genes. Therefore, cathelicidins can exert both pro- and anti-inflammatory activities depending on the disease and cellular context. KEY MESSAGES: The role of cathelicidin in a CLP model is investigated using cathelicidin-KO mice. Cathelicidin-KO mice show an enhanced immune response and improved survival rates. An anti-inflammatory effect of cathelicidin is likely to be detrimental for CLP. Cathelicidin-KO mice show upregulation of genes associated with increased plasma levels of pro-inflammatory Ils. Cathelicidins appear to have both pro- and anti-inflammatory properties.

Sepsis induces telomere shortening: a potential mechanism responsible for delayed pathophysiological events in sepsis survivors?

Sepsis survivors suffer from additional morbidities, including higher disk of readmissions, nervous system disturbances and cognitive dysfunction, and increased mortality, even several years after the initial episode of sepsis. In many ways, the phenotype of sepsis survivors resembles the phenotype associated with accelerated aging. Since telomere shortening is a hallmark of aging, we investigated whether sepsis also leads to telomere shortening. Male balb/c mice were divided into two groups: the control group received 100 µl of normal saline intraperitoneally; the sepsis group received 15 mg/kg of bacterial lipopolysaccharide i.p. After 48 hours, animals were sacrificed to collect blood, spleen and kidney. The human component of our study utilized blood samples obtained from patients in the Trauma Department and samples collected 7 days later in those patients who developed sepsis. Telomere length was measured by quantitative PCR. Since oxidative stress is a known inducer of telomere shortening, thiobarbituric acid reactive substances and superoxide dismutase (SOD) activity were analyzed in order to evaluate oxidative stress burden. Induction of endotoxemia in mice resulted in significant telomere shortening in spleen and kidney. Blood cells from patients that progressed to sepsis also exhibited a statistically significant reduction of telomere length. Endotoxemia in mice also induced an early-onset increase in oxidative stress markers, but was not associated with a downregulation of telomerase protein expression. We conclude that endotoxemia and sepsis induce telomere shortening in various tissues and hypothesize that this may contribute to the pathogenesis of the delayed pathophysiological events in sepsis survivors.

Extracellular matrix remodeling derangement in ex-obese patients.

A known consequence of the large weight loss after bariatric surgery is the appearance of large skinfolds, particularly in the abdomen region of the patients. The balance between the synthesis of extracellular matrix (ECM) components and their proteolysis, mainly by fibrinolytic systems and matrix metalloproteases (MMPs), may be disturbed in these patients. The causes underlying the deregulation of ECM remodeling that occurs in these patients are not, however, clear. We investigated molecular mechanisms responsible for this dysfunction of ECM remodeling process, comparing it to normal skin. Collagen types, MMP2 and MMP9 expression and activity, interleukins 1ß (IL1ß) and 6 (IL6), and transcription coactivator PGC-1ß expression were analyzed in 16 patients. Ex-obese patients presented increased expression of collagen types III and IV mRNA, increased expression of MMP2, decreased expression and activity of MMP9, and increased expression of PGC-1ß in the skin. Inflammation markers IL1ß and IL6 mRNA were not different. We have demonstrated that obese patients with extensive weight loss after bariatric surgery have increased expression of PGC-1ß in the skin, which can result in a decreased expression and activity of MMP9 and increased collagen types III and IV deposition. These molecular changes may contribute for the formation of saggy skinfolds observed in these patients and impair wound healing.

Proteomic profiling identifies N-acetylmuramoyl-l-alanine amidase as a novel biomarker of sepsis.

AIM: Sepsis is a critical condition that leads to high mortality and is the most common cause of death in intensive care units. Despite exhaustive efforts by the scientific community, a reliable biomarker for diagnosis, evolution and prognosis of sepsis is still lacking. Results & methodology: Here, using high-throughput proteomics, we describe N-acetylmuramoyl-l-alanine amidase as a novel candidate for differentiating infectious and noninfectious inflammatory syndromes. DISCUSSION & CONCLUSION: This is the first description of N-acetylmuramoyl-l-alanine amidase as a biomarker that can be used alone or in conjunction with other biomarkers to facilitate the diagnosis of sepsis in the critically ill.

Antimicrobial peptide LL-37 participates in the transcriptional regulation of melanoma cells.

Antimicrobial peptides are an ancient family of molecules that emerged millions of years ago and have been strongly conserved during the evolutionary process of living organisms. Recently, our group described that the human antimicrobial peptide LL-37 migrates to the nucleus, raising the possibility that LL-37 could directly modulate transcription under certain conditions. Here, we showed evidence that LL-37 binds to gene promoter regions, and LL-37 gene silencing changed the transcriptional program of melanoma A375 cells genes associated with histone, metabolism, cellular stress, ubiquitination and mitochondria.

The contributions of dipeptidyl peptidase IV to inflammation in heart failure.

Circulating dipeptidyl peptidase IV (DPPIV) activity correlates with cardiac dysfunction in humans and experimental heart failure (HF) models. Similarly, inflammatory markers are associated with poorer outcomes in HF patients. However, the contributions of DPPIV to inflammation in HF remain elusive. Therefore, this study aimed to investigate whether the cardioprotective effects of DPPIV inhibition after myocardial injury are accompanied by reduced cardiac inflammation, whether circulating DPPIV activity correlates with the levels of systemic inflammatory markers in HF patients, and whether leukocytes and/or splenocytes may be one of the sources of circulating DPPIV in HF. Experimental HF was induced in male Wistar rats by left ventricular myocardial injury after radiofrequency catheter ablation. The rats were divided into three groups: sham, HF, and HF + DPPIV inhibitor (sitagliptin). Six weeks after surgery, cardiac function, perfusion and inflammatory status were evaluated. Sitagliptin treatment improved cardiac function and perfusion, reduced macrophage infiltration, and diminished the levels of inflammatory biomarkers including TNF-α, IL-1ß, and CCL2. In HF patients, serum DPPIV activity correlated with CCL2, suggesting that leukocytes may be the source of circulating DPPIV in HF. Unexpectedly, DPPIV release was higher in splenocytes from HF rats and similar in HF circulating mononuclear cells compared with those from sham, suggesting an organ-specific modulation of DPPIV in HF. Collectively, our data provide new evidence that the cardioprotective effects of DPPIV inhibition in HF may be due to suppression of inflammatory cytokines. Moreover, they suggest that a vicious circle between DPPIV and inflammation may contribute to HF development and progression.

The role of nitric oxide in the epigenetic regulation of THP-1 induced by lipopolysaccharide.

AIMS: Changes in the gene expression are one of the molecular events involved in the Systemic of Inflammatory Response Syndrome during sepsis. The preconditioning with low doses of lipopolysaccharide (LPS) reduces the expression of pro-inflammatory genes leading to less tissue damage and better outcome. This hyporesponsive state called tolerance is associated to alterations in chromatin structure and nitric oxide (NO) production. In the current study, we demonstrated that tolerance induced by LPS was found to be NO-dependent and related to epigenetic changes. MAIN METHODS: THP-1 cells were cultivated in RPMI medium (Control), submitted to tolerance (500ng/mL of LPS 24h before challenge with 1000ng/mL of LPS during 24h Tolerant group) and challenge (1000ng/mL of LPS during 24h Directly challenged group). The analyses performed were: cytokines production, histone acetyl transferases/histone deacetylases (HAT/HDAC) activity, nitrosylation of HDAC-2 and -3, expression of acetylated histones H3 and H4. HDAC and Nitric Oxide Synthases (NOS) activities were inhibited with 30mM trichostatin (TSA) and 100µM LNAME, respectively. KEY FINDINGS: Administration of low doses of LPS repressed the production of IL-6 and IL-10, however this effect was abolished with the inhibition of NOS activity and by TSA in the case of IL-10. Tolerance modulates the activity of HAT and, consequently, the acetylation of histones H3 and H4. Inhibition of NO decreases acetylation of Histones. The HDACs 2 and 3 were nitrosylated after the tolerance induction. SIGNIFICANCE: The tolerance to LPS regulates the cytokine production by modulating chromatin structure and this event is NO dependent.

Low level laser therapy reduces acute lung inflammation without impairing lung function.

Acute lung injury is a condition characterized by exacerbate inflammatory reaction in distal airways and lung dysfunction. Here we investigate the treatment of acute lung injury (ALI) by low level laser therapy (LLLT), an effective therapy used for the treatment of patients with inflammatory disorders or traumatic injuries, due to its ability to reduce inflammation and promote tissue regeneration. However, studies in internal viscera remains unclear. C57BL/6 mice were treated with intratracheal lipopolysaccharide (LPS) (5 mg/kg) or phosphate buffer saline (PBS). Six hours after instillation, two groups were irradiated with laser at 660 nm and radiant exposure of 10 J/cm2 . Intratracheal LPS inoculation induced a marked increase in the number of inflammatory cells in perivascular and alveolar spaces. There was also an increase in the expression and secretion of cytokines (TNF-α, IL-1ß, IL-6,) and chemokine (MCP-1). The LLLT application induced a significant decrease in both inflammatory cells influx and inflammatory mediators secretion. These effects did not affect lung mechanical properties, since no change was observed in tissue resistance or elastance. In conclusion LLLT is able to reduce inflammatory reaction in lungs exposed to LPS without affecting the pulmonary function and recovery.

Novel role of TLR4 in NAFLD development: Modulation of metabolic enzymes expression.

The rise in the prevalence of obesity and metabolic syndrome turned NAFLD as the most common cause of chronic liver diseases worldwide. Although the role of toll like receptors, especially TLR4, as activators of inflammatory pathways in liver diseases is well established, our goal was to investigate if TLR4 activation could modulate metabolic lipid pathways and alter the onset of NAFLD. We used LDL receptor-deficient mice (LDLrKO) fed with an atherogenic diet as a model. The role of TLR4 activation was evaluated by crossing LDLrKO mice with the TLR4 knockout mice. Animals were fed for 12weeks with high-fat high-cholesterol diet (HFD) containing 18% saturated fat and 1.25% cholesterol. TLR4/LDLr KO mice presented lower triacylglyceride (TAG) plasma levels when compared to LDLrKO, despite the type of diet ingested. HFD induced TAG and cholesterol accumulation in the liver of all mice genotypes studied, but TLR4/LDLr KO presented lower TAG accumulation than LDLrKO mice. Gene expression of TAG synthesis enzymes (ApoB100, MTTP, GPAT1 and GPAT4) was not differentially altered in TLR4/LDLr KO and LDLrKO mice. On the other hand, TLR4 deficiency enhanced the expression of several enzymes involved in the oxidation of fatty acids, as follows: ACOX, CPT-1, MTPa, MTBb, PBE and 3-ketoacyl-CoA thiolase. Acyl-carnitine plasma profile showed an increase in C0 and C2 concentration in TLR4/LDLr KO group, corroborating the hypothesis of increased fat oxidation. Our results indicate that TLR4 may have an important role in the onset of steatosis, once its depletion enhances fatty acid oxidation in the liver of mice, preventing triglyceride accumulation.