Enhanced monocyte chemoattractant protein-1 production in aging mice exaggerates cardiac depression during endotoxemia

m6A methylation in myocardial tissue of septic mice analyzed using MeRIP/m6A-sequencing and RNA-sequencing

Septic cardiomyopathy is a secondary myocardial injury caused by sepsis. N6-methyl-adenosine (m6A) modification is involved in the pathological progression of septic cardiomyopathy; however, the pathological mechanism remains unclear. In this study, we identified the overall m6A modification pattern in septic myocardial injury and determined its potential interactions with differentially expressed genes (DEGs). A sepsis mouse model exhibiting septic symptoms and myocardial tissue damage was induced by lipopolysaccharide (LPS). LPS-induced septic myocardial tissues and control myocardial tissues were subjected to methylated RNA immunoprecipitation sequencing and RNA sequencing to screen for differentially expressed m6A peaks and DEGs. We identified 859 significantly m6A-modified genes in septic myocardial tissues, including 432 upregulated and 427 downregulated genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed to explore the biological importance of differentially expressed m6A methylated genes and DEGs. Differentially expressed m6A methylated genes were enriched in immune- and inflammation-related pathways. Conjoint analysis revealed co-expression of differentially expressed m6A genes and DEGs, including genes that were upregulated or downregulated and those showing opposite trends. High expression of m6A-related genes (WTAP and IGF2BP2), interleukin-17, and interleukin-17 pathway-related genes (MAPK11 and TRAF3IP2) was verified using reverse transcription-quantitative PCR. We confirmed the presence of m6A modification of the transcriptome and m6A-mediated gene expression in septic myocardial tissues.

DNA-PKcs Phosphorylates Cofilin2 to Induce Endothelial Dysfunction and Microcirculatory Disorder in Endotoxemic Cardiomyopathy

The presence of endotoxemia is strongly linked to the development of endothelial dysfunction and disruption of myocardial microvascular reactivity. These factors play a crucial role in the progression of endotoxemic cardiomyopathy. Sepsis-related multiorgan damage involves the participation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). However, whether DNA-PKcs contributes to endothelial dysfunction and myocardial microvascular dysfunction during endotoxemia remains unclear. Hence, we conducted experiments in mice subjected to lipopolysaccharide (LPS)-induced endotoxemic cardiomyopathy, as well as assays in primary mouse cardiac microvascular endothelial cells. Results showed that endothelial-cell-specific DNA-PKcs ablation markedly attenuated DNA damage, sustained microvessel perfusion, improved endothelial barrier function, inhibited capillary inflammation, restored endothelium-dependent vasodilation, and improved heart function under endotoxemic conditions. Furthermore, we show that upon LPS stress, DNA-PKcs recognizes a TQ motif in cofilin2 and consequently induces its phosphorylation at Thr25. Phosphorylated cofilin2 shows increased affinity for F-actin and promotes F-actin depolymerization, resulting into disruption of the endothelial barrier integrity, microvascular inflammation, and defective eNOS-dependent vasodilation. Accordingly, cofilin2-knockin mice expressing a phospho-defective (T25A) cofilin2 mutant protein showed improved endothelial integrity and myocardial microvascular function upon induction of endotoxemic cardiomyopathy. These findings highlight a novel mechanism whereby DNA-PKcs mediates cofilin2Thr25 phosphorylation and subsequent F-actin depolymerization to contribute to endotoxemia-related cardiac microvascular dysfunction.

Aging exacerbates cardiac dysfunction and mortality in sepsis through enhancing TLR2 activity

Introduction

Sepsis is prevalent in the elderly population with increased incidence and mortality. Currently, the mechanism by which aging increases the susceptibility to sepsis and worsens outcome is unclear. We tested the hypothesis that aging exacerbates cardiac dysfunction in sepsis through a Toll-like receptor 2 (TLR2)-dependent mechanism.

Methods

Male young adult (4-6 months) and old (18-20 months) wild type (WT) and TLR2 knockout (KO) mice were subject to moderate sepsis by cecal ligation and puncture. Additional groups of young adult and old WT mice were treated with TLR2 agonist Pam3CSK4. Left ventricle (LV) performance was evaluated with a pressure-volume microcatheter. Tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and monocyte chemoattractant protein-1 (MCP-1) in the myocardium and plasma were assessed using enzyme-linked immunosorbent assay.

Results

Sepsis reduced LV ejection fraction and cardiac output in both young adult and old WT mice. However, identical CLP caused more severe cardiac dysfunction and high mortality in old WT mice that were accompanied by greater levels of TNF-α, IL-1β, IL-6 and MCP-1 in the myocardium and plasma. TLR2 KO diminished aging-related difference in myocardial and systemic inflammatory response, resulting in improved cardiac function and decreased mortality in old septic mice. In addition, higher myocardial TLR2 levels in old WT mice resulted in greater myocardial inflammatory response and worse cardiac dysfunction following administration of TLR2 agonist.

Conclusion

Moderate sepsis results in greater cardiac dysfunction and significant mortality in old mice. Aging elevates TLR2 level/activity to exacerbate the inflammatory response to sepsis, leading to worse cardiac dysfunction and mortality.

Up-regulation of Myocardial Klotho Expression to Promote Cardiac Functional Recovery in Old Mice following Endotoxemia

Objective

Endotoxemic cardiac dysfunction contributes to greater morbidity and mortality in elderly patients with sepsis. This study tested the hypothesis that Klotho insufficiency in aging heart exaggerates and prolongs myocardial inflammation to hinder cardiac function recovery following endotoxemia.

Methods

Endotoxin (0.5 mg/kg, iv) was administered to young adult (3-4 months) and old (18-22 months) mice with or without subsequent treatment with recombinant interleukin-37 (IL-37, 50 μg/kg, iv) or recombinant Klotho (10 μg/kg, iv). Cardiac function was analyzed using a microcatheter 24, 48 and 96 h later. Myocardial levels of Klotho, ICAM-1, VCAM-1 and IL-6 were determined by immunoblotting and ELISA.

Results

In comparison to young adult mice, old mice had worse cardiac dysfunction accompanied by greater myocardial levels of ICAM-1, VCAM-1 and IL-6 at each time point following endotoxemia and failed to fully recover cardiac function by 96 h. The exacerbated myocardial inflammation and cardiac dysfunction were associated with endotoxemia-caused further reduction of lower myocardial Klotho level in old mice. Recombinant IL-37 promoted inflammation resolution and cardiac functional recovery in old mice. Interestingly, recombinant IL-37 markedly up-regulated myocardial Klotho levels in old mice with or without endotoxemia. Similarly, recombinant Klotho suppressed myocardial inflammatory response and promoted inflammation resolution in old endotoxemic mice, leading to complete recovery of cardiac function by 96 h.

Conclusion

Myocardial Klotho insufficiency in old endotoxemic mice exacerbates myocardial inflammatory response, impairs inflammation resolution and thereby hinders cardiac functional recovery. IL-37 is capable of up-regulating myocardial Klotho expression to improve cardiac functional recovery in old endotoxemic mice.

CC chemokines family in fibrosis and aging: From mechanisms to therapy

Fibrosis is a universal aging-related pathological process in the different organ, but is actually a self-repair excessive response. To date, it still remains a large unmet therapeutic need to restore injured tissue architecture without detrimental side effects, due to the limited clinical success in the treatment of fibrotic disease. Although specific organ fibrosis and the associated triggers have distinct pathophysiological and clinical manifestations, they often share involved cascades and common traits, including inflammatory stimuli, endothelial cell injury, and macrophage recruitment. These pathological processes can be widely controlled by a kind of cytokines, namely chemokines. Chemokines act as a potent chemoattractant to regulate cell trafficking, angiogenesis, and extracellular matrix (ECM). Based on the position and number of N-terminal cysteine residues, chemokines are divided into four groups: the CXC group, the CX3C group, the (X)C group, and the CC group. The CC chemokine classes (28 members) is the most numerous and diverse subfamily of the four chemokine groups. In this Review, we summarized the latest advances in the understanding of the importance of CC chemokine in the pathogenesis of fibrosis and aging and discussed potential clinical therapeutic strategies and perspectives aimed at resolving excessive scarring formation.

MCP-1 Signaling Disrupts Social Behavior by Modulating Brain Volumetric Changes and Microglia Morphology

Autism spectrum disorder (ASD) is a disease characterized by reduced social interaction and stereotypic behaviors and related to macroscopic volumetric changes in cerebellar and somatosensory cortices (SPP). Epidemiological and preclinical models have confirmed that a proinflammatory profile during fetal development increases ASD susceptibility after birth. Here, we aimed to globally identify the effect of maternal exposure to high-energy dense diets, which we refer to as cafeteria diet (CAF) on peripheral and central proinflammatory profiles, microglia reactivity, and volumetric brain changes related to assisting defective social interaction in the mice offspring. We found a sex-dependent effect of maternal exposure to CAF diet or inoculation of the dsARN mimetic Poly (I:C) on peripheral proinflammatory and social interaction in the offspring. Notably, maternal exposure to CAF diet impairs social interaction and favors an increase in anxiety in male but not female offspring. Also, CAF diet exposure or Poly (I:C) inoculation during fetal programming promote peripheral proinflammatory profile in the ASD-diagnosed male but not in females. Selectively, we found a robust accumulation of the monocyte chemoattractant protein-1 (MCP-1) in plasma of ASD-diagnosed males exposed to CAF during fetal development. Biological assessment of MCP-1 signaling in brain confirms that systemic injection of MCP-1-neutralizing antibody reestablished social interaction and blocked anxiety, accompanied by a reduction in cerebellar lobule X (CbX) volume and an increase volume of the primary somatosensory (SSP) cortex in male offspring. These data highlight the contribution of diet-dependent MCP-1 signaling on volumetric brain changes and microglia morphology promoting ASD-like behavior in male mice.

Predictive Value of C-reactive Protein, Lactate Dehydrogenase, Ferritin and D-dimer Levels in Diagnosing COVID-19 Patients: a Retrospective Study

Background:

Since December 2019. millions of people in the world have been affected with the novel Coronavirus disease-2019 (COVID-19) pandemic, and high economic impact has affect many countries especially low socioeconomic one like Iraq due to the high cost and limited availability of RT-PCR for diagnosis of COVID-19, so there should be predictive low cost easily available laboratory tests that can be used before proceeding to the high cost techniques.

Objective:

In this retrospective study we aimed to evaluate the diagnostic accuracy of CRP, ferritin, LDH and D-dimer in predicting positive cases of COVID-19 in Iraq.

Methods:

It is a retrospective observational cohort study based on STARD guidelines to determine the diagnostic accuracy of (CRP, LDH, ferritin and D dimer) for COVID-19 of electronic medical records of private medical center in Najaf city, at which 566 individuals were recruited. The investigated subjects were either in close contact with previously COVID-19 positive patients or have one or more symptoms of COVID-19. They were categorized into 2 groups, 205 subjects diagnosed with RT-PCR as COVID-19 negative, and 361 COVID-19 positive patients, results of study variables of the cohort were recruited from the medical records.

Results:

Combining of these parameters had the following findings: CRP + ferritin; AUC: 0.77 with 55% sensitivity and 97% specificity, Ferritin + LDH; AUC: 0.83 with 65% sensitivity and 92% specificity, CRP+LDH; AUC: 0.78 with 56% sensitivity and 98% specificity, CRP + LDH + ferritin; AUC: 0.85, with 73% sensitivity and 88% specificity, CRP + LDH + ferritin + D dimer; AUC: 0.85 75% sensitivity and 87% specificity.

Conclusion:

Combination of routine laboratory biomarkers (CRP, LDH and ferritin ±D dimer) can be used to predict the diagnosis of COVID-19 with an accepted sensitivity and specificity before proceeding to definitive diagnosis by RT-PCR.

Changes of inflammatory and oxidative stress biomarkers in dogs with different stages of heart failure

Background

Heart failure (HF) is associated with changes in inflammatory and oxidative stress biomarkers. This study aimed to evaluate the changes of a panel of inflammatory and oxidative stress biomarkers in dogs with different stages of HF and its relation with the severity of the disease and echocardiographic changes. A total of 29 dogs with HF as a result of myxomatous mitral valve degeneration or dilated cardiomyopathy were included and classified as stage-A (healthy), B (asymptomatic dogs), C (symptomatic dogs) and D (dogs with end-stage HF) according to the ACVIM staging system. In these dogs an ecnhocardiographic examination was performed and cytokines, and inflammatory and oxidative stress markers were evaluated in serum.

Results

KC-like was significantly increased in dogs of stage-C (P < 0.01) and -D (P < 0.05) compared with stage-A and -B. Stage-D dogs showed significantly higher serum CRP and Hp (P < 0.05) but lower serum antioxidant capacity (PON1, TEAC, CUPRAC, and thiol) compared to stage-A and -B (P < 0.05). After the treatment, serum levels of CRP, Hp and KC-like decreased and serum antioxidant levels increased compared to their pre-treatment values. Left ventricular dimension and LA/Ao ratio correlated positively with CRP, MCP-1, and KC-like but negatively with PON1, GM-CSF, IL-7 and antioxidant biomarkers (P < 0.01).

Conclusion

Our results showed that dogs with advanced HF show increases in positive acute-phase proteins and selected inflammatory cytokines such as KC-like, and decreases in antioxidant biomarkers, indicating that inflammation and oxidative stress act as collaborative partners in the pathogenesis of HF. Some of these biomarkers of inflammation and oxidative stress could have the potential to be biomarkers to monitor the severity of the disease and the effect of treatment.

Sex-, Age-, and Metabolic Disorder-Dependent Distributions of Selected Inflammatory Biomarkers among Community-Dwelling Adults

BACKGROUND

Inflammatory cytokines are increasingly utilized to detect high-risk individuals for cardiometabolic diseases. However, with large population and assay methodological heterogeneity, no clear reference currently exists.

METHODS

Among participants of the Cardiovascular and Metabolic Diseases Etiology Research Center cohort, of community-dwelling adults aged 30 to 64 without overt cardiovascular diseases, we presented distributions of tumor necrosis factor (TNF)-α and -β, interleukin (IL)-1α, -1β, and 6, monocyte chemoattractant protein (MCP)-1 and -3 and high sensitivity C-reactive protein (hsCRP) with and without non-detectable (ND) measurements using multiplex enzyme-linked immunosorbent assay. Then, we compared each markers by sex, age, and prevalence of type 2 diabetes mellitus, hypertension, and dyslipidemia, using the Wilcoxon Rank-Sum Test.

RESULTS

In general, there were inconsistencies in direction and magnitude of differences in distributions by sex, age, and prevalence of cardiometabolic disorders. Overall, the median and the 99th percentiles were higher in men than in women. Older participants had higher TNF-α, high sensitivity IL-6 (hsIL-6), MCP-1, hsCRP, TNF-β, and MCP-3 median, after excluding the NDs. Participants with type 2 diabetes mellitus had higher median for all assayed biomarkers, except for TNF-β, IL-1α, and MCP-3, in which the medians for both groups were 0.00 due to predominant NDs. Compared to normotensive group, participants with hypertension had higher TNF-α, hsIL-6, MCP-1, and hsCRP median. When stratifying by dyslipidemia prevalence, the comparison varied significantly depending on the treatment of NDs.

CONCLUSION

Our findings provide sex-, age-, and disease-specific reference values to improve risk prediction and diagnostic performance for inflammatory diseases in both population- and clinic-based settings.

GDF3 Protects Mice against Sepsis-Induced Cardiac Dysfunction and Mortality by Suppression of Macrophage Pro-Inflammatory Phenotype

Macrophages are critical for regulation of inflammatory response during endotoxemia and septic shock. However, the mediators underlying their regulatory function remain obscure. Growth differentiation factor 3 (GDF3), a member of transforming growth factor beta (TGF-β) superfamily, has been implicated in inflammatory response. Nonetheless, the role of GDF3 in macrophage-regulated endotoxemia/sepsis is unknown. Here, we show that serum GDF3 levels in septic patients are elevated and strongly correlate with severity of sepsis and 28-day mortality. Interestingly, macrophages treated with recombinant GDF3 protein (rGDF3) exhibit greatly reduced production of pro-inflammatory cytokines, comparing to controls upon endotoxin challenge. Moreover, acute administration of rGDF3 to endotoxin-treated mice suppresses macrophage infiltration to the heart, attenuates systemic and cardiac inflammation with less pro-inflammatory macrophages (M1) and more anti-inflammatory macrophages (M2), as well as prolongs mouse survival. Mechanistically, GDF3 is able to activate Smad2/Smad3 phosphorylation, and consequently inhibits the expression of nod-like receptor protein-3 (NLRP3) in macrophages. Accordingly, blockade of Smad2/Smad3 phosphorylation with SB431542 significantly offsets rGDF3-mediated anti-inflammatory effects. Taken together, this study uncovers that GDF3, as a novel sepsis-associated factor, may have a dual role in the pathophysiology of sepsis. Acute administration of rGDF3 into endotoxic shock mice could increase survival outcome and improve cardiac function through anti-inflammatory response by suppression of M1 macrophage phenotype. However, constitutive high levels of GDF3 in human sepsis patients are associated with lethality, suggesting that GDF3 may promote macrophage polarization toward M2 phenotype which could lead to immunosuppression.

A novel isoquinoline derivative exhibits anti-inflammatory properties and improves the outcomes of endotoxemia

BACKGROUND

Sepsis initiates an inflammatory response that causes widespread injury, and candidates for related myocardial depressant factors include cytokines and nitric oxide (NO). Nuclear factor kappa-B (NF-κB) stimulated by toll-like receptor 4 activation in sepsis mediates the transcription of multiple proinflammatory genes. These inflammatory mediators can cause myocardial dysfunction, which may deteriorate sepsis outcomes. To address this risk, we investigated the potential beneficial effects of a novel isoquinolines derivative, CYY054c, in LPS-induced inflammatory response leading to endotoxemia.

METHODS

The effects of CYY054c on cytokine and inflammatory-related protein production were evaluated in lipopolysaccharide (LPS)-stimulated macrophages. To determine whether CYY054c alleviates inflammatory storm-induced myocardial dysfunction in vivo, LPS was injected in rats, and cardiac function was measured by a pressure-volume loop.

RESULTS

CYY054c inhibited LPS-induced NF-κB expression in macrophages and reduced the release of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), as well as the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). In the animal studies, CYY054c alleviated LPS-upregulated plasma TNF-α, IL-1β, IL-6, and NO concentrations, as well as cardiac monocyte chemotactic protein-1, iNOS, and COX-2 expression in rats, contributing to the improvement of cardiac function during endotoxemia.

CONCLUSIONS

The reduction of NF-κB-mediated inflammatory mediators and the maintenance of hemodynamic performance by CYY054c improved the outcomes during endotoxemia. CYY054c may be a potential therapeutic agent for sepsis.

Propofol attenuates sepsis-induced acute kidney injury by regulating miR-290-5p/CCL-2 signaling pathway

Previous studies have indicated that propofol has immunomodulatory and antioxidative properties. However, the renoprotection effect and the precise mechanisms of propofol in sepsis-induced renal injury remain unclear. The purpose of the present study was to investigate the role of miR-290-5p/CCL-2 signaling in septic mice treatment with propofol. Mice were treated with propofol (50 mg/kg) twice within 24 h. Survival outcome was monitored within 48 h. The mRNA and protein levels were assayed by qRT-PCR and western blotting, respectively. Mouse podocytes (MPC5) were treated with lipopolysaccharide (LPS) to establish the cell model in vitro. The proliferation of MPC5 was monitored using the MTS assay. Cell apoptosis was analyzed by flow cytometry. Propofol improved survival outcome and alleviated acute kidney injury in cecal ligation and puncture-operated mice. Propofol increased miR-290-5p expression and decreased CCL-2 and inflammatory cytokines levels in the kidney for septic mice. We found that miR-290-5p was a direct regulator of CCL-2 in MPC5. Propofol could abrogate LPS-induced growth inhibition and apoptosis in MPC5. Meanwhile, propofol inhibited CCL-2 expression in LPS-treated MPC5, however, knockdown of miR-290-5p abrogated the inhibitory effect propofol on the mRNA and protein expressions of CCL-2. Propofol could serve as an effective therapeutic medication to suppress sepsis-induced renal injury in vivo and in vitro by regulating the miR-290-5p/CCL-2 signaling pathway.

Early plasma monocyte chemoattractant protein 1 predicts the development of sepsis in trauma patients: A prospective observational study

Monocyte chemoattractant protein 1 (MCP-1) is an initiating cytokine of the inflammatory cascade. Extracellular MCP-1 exhibits pro-inflammatory characteristic and plays a central pathogenic role in critical illness. The purpose of the study was to identify the association between plasma MCP-1 levels and the development of sepsis after severe trauma.The plasma levels of MCP-1 in severe trauma patients were measured by a quantitative enzyme-linked immune sorbent assay and the dynamic release patterns were recorded at three time points during seven days post-trauma. The related factors of prognosis were compared between sepsis and non-sepsis groups and analyzed using multivariate logistic regression analysis. We also used receiver operating characteristic (ROC) curves to assess the values of different variables in predicting sepsis.A total of 72 patients who met criteria indicative of severe trauma (72.22% of male; mean age, 49.40 ± 14.29 years) were enrolled. Plasma MCP-1 concentrations significantly increased on post-trauma day 1 and that this increase was significantly correlated with the Injury Severity Score (ISS) and interleukin-6 (IL-6). Multivariate logistic regression analysis showed that early MCP-1, ISS, and IL-6 were independent risk factors for sepsis in severe trauma patients. Incorporation of the early MCP-1 into the ISS can increase the discriminative performance for predicting development of sepsis.Early plasma MCP-1 concentrations can be used to assess the severity of trauma and is correlated with the development of sepsis after severe trauma. The addition of the early MCP-1 levels to the ISS significantly improves its ability to predict development of sepsis.

Klotho suppresses the inflammatory responses and ameliorates cardiac dysfunction in aging endotoxemic mice

Background

Aging augments endotoxemic cardiac dysfunction, but the mechanism remains unclear. Anti-aging protein Klotho has been found to modulate tissue inflammatory responses. We tested the hypothesis that a reduced Klotho level in aging heart plays a role in the augmented endotoxemic cardiac dysfunction.

Materials and Methods

Endotoxin (0.5 mg/kg, iv) was injected to adults (4-6 months) and aging (18-20 months) C57BL/6 mice. Recombinant Klotho (10 μg/kg, iv) was administered to a group of aging mice after endotoxin injection. Cardiac function was analyzed using a microcatheter at 24 and 48 h after endotoxin administration. Myocardial levels of Klotho and heat shock protein 70 (HSP70) were determined by immunoblotting, and plasma and myocardial cytokines were analyzed using ELISA.

Results

More severe cardiac dysfunction in aging mice were accompanied by greater cytokine levels in the plasma and myocardium. Klotho was detected in the myocardial tissue. Klotho levels were lower in aging hearts and were further reduced during endotoxemia. Myocardial HSP70 levels were correlated with Klotho levels. Recombinant Klotho increased myocardial HSP70, inhibited NF-κB activation, reduced cytokine levels, and improved cardiac function in aging endotoxemic mice. Delivery of HSP70 into cultured macrophages suppressed endotoxin-induced NF-κB activation.

Conclusions

Aging-related augmentation of inflammatory responses and cardiac dysfunction is associated with relative Klotho deficiency. Post-treatment with recombinant Klotho suppresses the inflammatory responses and improves cardiac function in aging endotoxemic mice. Klotho modulates HSP70 levels and HSP70 appears to be involved in the anti-inflammatory mechanism of Klotho. Klotho may have therapeutic potential in amelioration of aging-related endotoxemic cardiac dysfunction.

Interleukin-37 suppresses the inflammatory response to protect cardiac function in old endotoxemic mice

Myocardial inflammatory responses to endotoxemia are enhanced in old mice, which results in worse cardiac dysfunction. Anti-inflammatory cytokine interleukin (IL)-37 has a broad effect on innate immunoresponses. We hypothesized that IL-37 suppresses myocardial inflammatory responses to protect cardiac function during endotoxemia in old mice. Old (20-24month) wild-type (WT), and IL-37 transgenic (IL-37tg) mice were treated with lipopolysaccharide (LPS, 0.5mg/kg, iv) or normal saline (0.1ml/mouse, iv). Six hours later, left ventricle (LV) function was assessed using a pressure-volume microcatheter. Levels of monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 in plasma and myocardial tissue, as well as mononuclear cell density in the myocardium, were examined. Cardiac microvascular endothelial cells isolated from WT and IL-37tg mice were treated with LPS (0.2µg/ml) for 0.5-24h. Nuclear factor-kappa B (NF-κB) p65 phosphorylation was examined by immunoblotting, and MCP-1 levels in cell culture supernatant was determined using enzyme-linked immunosorbent assay. LV dysfunction in old WT endotoxemic mice was accompanied by up-regulated MCP-1, myocardial accumulation of mononuclear cells and production of TNF-α, IL-1β and IL-6. Expression of IL-37 suppressed myocardial inflammatory responses to endotoxemia in old mice, resulting in improved LV function. Treatment of old WT endotoxemic mice with recombinant IL-37 also improved LV function. In vitro experiments revealed that cardiac microvascular endothelial cells from IL-37tg mice had attenuated NF-κB activation and MCP-1 production following LPS stimulation. In conclusion, IL-37 is potent to suppress myocardial inflammation and protects against cardiac dysfunction during endotoxemia in old mice.

Association study of MCP-1 promoter polymorphisms with the susceptibility and progression of sepsis

Previous studies have indicated that the monocyte chemo-attractant protein 1 (MCP-1), also referred to as C-C motif chemokine ligand 2 (CCL2), plays a significant role in the pathogenesis of sepsis, and this study investigated the clinical relevance of two MCP-1 gene polymorphisms on sepsis onset and progression. The Multiplex SNaPshot genotyping method was used to detect MCP-1 gene polymorphisms in the Chinese Han population (403 sepsis patients and 400 controls). MCP-1 mRNA expression levels were measured using real-time quantitative PCR, and enzyme-linked immunosorbent assays were used to analyze MCP-1, tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and interleukin-1 beta (IL-1β) plasma concentrations. The rs1024611 polymorphism analysis showed lower frequencies of minor homozygous genotype (AA) and allele (A) in sepsis patients compared to the healthy controls (19.4% vs. 31.5%, P = 0.0001 and 45.9% vs. 54.8%, P = 0.0004, respectively). And the frequencies of GG genotype and G allele were lower in sepsis patients compared to the controls (19.6% vs. 31.3%, P = 0.0002 and 46.0% vs. 54.5%, P = 0.0007, respectively). The rs1024611 AG/GG and rs2857656 GC/CC genotypes were both overrepresented in patients with severe sepsis (both P = 0.0005) and septic shock (P = 0.010 and P = 0.015, respectively) compared to the patients with mild sepsis. Moreover, among sepsis patients, the rs1024611 AG/GG and rs2857656 GC/CC carriers exhibited significant increases in expression levels of MCP-1 (P = 0.025), TNF-α (P = 0.034) and IL-6 (P = 0.043) compared with the rs1024611 AA or rs2857656 GG carriers. This study provides valuable clinical evidence that the MCP-1/CCL2 polymorphisms rs1024611 and rs2857656 are associated with sepsis susceptibility and development. We conclude that MCP-1/CCL2 plays a significant role in the pathogenesis of sepsis, which has potentially important therapeutic implications.

Cardioprotective effects of irbesartan in polymicrobial sepsis : The role of the p38MAPK/NF-κB signaling pathway

BACKGROUND

Sepsis is a systemic inflammatory response usually correlated with multi-organ failure. Myocardial dysfunction is one of the adverse outcomes in septic patients and results in high mortality rates. The aim of this study was to investigate the impact of irbesartan in attenuation of cardiac depression during polymicrobial sepsis via decreased activation of the phospho-p38MAPK/nuclear factor (NF)-κB signaling pathway.

MATERIALS AND METHODS

A model of polymicrobial sepsis induced via cecal ligation and puncture (CLP) with 8- to 12-week-old albino mice was used. Mice were treated with i.p. irbesartan (3 mg/kg) 1 h before CLP. Using a micro-tipped transducer catheter, the following hemodynamic parameters were evaluated after CLP: heart rate, ejection fraction, left ventricular (LV) end-diastolic pressure, LV systolic pressure, and cardiac output. Plasma levels of proinflammatory cytokines, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-6, monocyte chemoattractant protein-1 (MCP-1), and cardiac troponin I (cTn-I), were measured via ELISA analysis. The degree of p38MAPK and NF-κB phosphorylation was assessed via Western blotting.

RESULTS

Mice treated with irbesartan displayed improvement in LV function (ejection fraction: 42.4 ± 1.1% vs. 27.8 ± 3% in CLP mice). The attenuation of cardiac depression in irbesartan-treated mice was associated with lower levels of MCP-1 in plasma and a reduction in the levels of TNF-alpha, IL-1beta, and IL-6. Furthermore, irbesartan-treated mice displayed lower expression levels of p38-MAPK and NF-κB phosphorylation.

CONCLUSION

Irbesartan can attenuate cardiac dysfunction during polymicrobial sepsis possibly via a reduction of proinflammatory cytokines through decreased activation of the p38MAPK/NF-κB pathways.

Indocyanine Green-001 (ICG-001) Attenuates Wnt/β-catenin-induces Myocardial Injury Following Sepsis

Objective:

To investigate the mechanistic pathway of both indocyanine green (ICG)-001 in attenuated endotoxemia-induced cardiac depression through downregulation cardiac Wnt/ β-catenin cell signaling.

Materials and Methods:

Adult (4–6 months) male Albino-Webster mice, their weights ranged from 25 to 30 g, were pretreated with ICG-001 i.p., following cecal ligation and puncture (CLP). Left ventricle (LV) function was assessed using a microcatheter system. Monocyte chemoattractant protein-1 (MCP-1) and cytokines mediators in plasma and myocardium were analyzed by enzyme-linked immunosorbent assay. Further, the cardiac Wnt protein measured by quantitative real-time polymerase chain reaction while β-catenin analysis through Western blotting procedure. The pathological changes and cells injury in the myocardium were examined using hematoxylin and eosin staining.

Results:

CLP mice displayed worse LV function. The exaggerated cardiac depression in CLP mice was associated with higher levels of MCP-1 and cytokines in plasma and myocardium together with greater cardiac levels of cardiac troponin-I and Wnt/β-catenin. Neutralization of sepsis by either ICG-001resulted in improved LV function and reductions in inflammatory mediators.

Conclusion:

Taken together, these data showed that ICG-001 improved LV function following sepsis through downregulation of Wnt/β-catenin and serve as a potential mechanistic pathway ICG-001 in therapeutic cardiac endotoxemia in animal model.

Exercise-induced increase in IL-6 level enhances GLUT4 expression and insulin sensitivity in mouse skeletal muscle

A single bout of exercise is known to increase the insulin sensitivity of skeletal muscle; however, the underlying mechanism of this phenomenon is not fully understood. Because a single bout of exercise induces a transient increase in blood interleukin-6 (IL-6) level, we hypothesized that the enhancement of insulin sensitivity after a single bout of exercise in skeletal muscle is mediated at least in part through IL-6-dependent mechanisms. To test this hypothesis, C57BL6J mice were intravenously injected with normal IgG or an IL-6 neutralizing antibody before exercise. Twenty-four hours after a single bout of exercise, the plantaris muscle was harvested to measure insulin sensitivity and glucose transporter (GLUT)-4 expression levels by ex-vivo insulin-stimulated 2-deoxyglucose (2-DG) uptake and Western blotting, respectively. Compared with sedentary mice, mice that performed exercise showed enhanced IL-6 concentration, insulin-stimulated 2-DG uptake, and GLUT-4 expression in the plantaris muscle. The enhanced insulin sensitivity and GLUT4 expression were canceled by injection of the IL-6 neutralizing antibody before exercise. In addition, IL-6 injection increased GLUT4 expression, both in the plantaris muscle and the soleus muscle in C57BL6J mice. Furthermore, a short period of incubation with IL-6 increased GLUT4 expression in differentiated C2C12 myotubes. In summary, these results suggested that IL-6 increased GLUT4 expression in muscle and that this phenomenon may play a role in the post-exercise enhancement of insulin sensitivity in skeletal muscle.

Ovarian kisspeptin expression is related to age and to monocyte chemoattractant protein-1

PURPOSE

The objective of this study was to test the hypothesis that ovarian kisspeptin (kiss1) and its receptor (kiss1r) expression are affected by age, obesity, and the age- and obesity-related chemokine monocyte chemoattractant protein-1 (MCP-1).

METHODS

Ovaries from reproductive-aged and older C57BL/6J mice fed normal chow (NC) or high-fat (HF) diet, ovaries from age-matched young MCP-1 knockout and young control mice on NC, and finally, cumulus and mural granulosa cells (GCs) from women who underwent in vitro fertilization (IVF) were collected. Kiss1, kiss1r, anti-Mullerian hormone (AMH), and AMH receptor (AMHR-II) messenger RNA (mRNA) expression levels were quantified using real-time polymerase chain reaction (RT-PCR).

RESULTS

In mouse ovaries, kiss1 and kiss1r mRNA levels were significantly higher in old compared to reproductive-aged mice, and diet-induced obesity did not alter kiss1 or kiss1r mRNA levels. Compared to young control mice, young MCP-1 knockout mice had significantly lower ovarian kiss1 mRNA but significantly higher AMH and AMHR-II mRNA levels. In human cumulus GCs, kiss1r mRNA levels were positively correlated with age but not with BMI. There was no expression of kiss1 mRNA in either cumulus or mural GCs.

CONCLUSION

These data suggest a possible age-related physiologic role for the kisspeptinergic system in ovarian physiology. Additionally, the inflammatory MCP-1 may be associated with kiss1 and AMH genes, which are important in ovulation and folliculogenesis, respectively.

Aging and the intramyocardial inflammatory response

The sepsis-induced intramyocardial inflammatory response results in decreased ventricular function and myocardial damage. Chemokines such as monocyte chemoattractant protein-1 causally contribute to retention of intramyocardial mononuclear leukocytes and subsequent ventricular dysfunction during endotoxemic shock in mice and, importantly, this effect is age dependent. It is therefore useful to consider where monocyte chemoattractant protein-1 fits in the complex pathway leading to ventricular dysfunction during sepsis, why this might be an age-dependent effect, and what this implies for care of older sepsis patients.