Role of S100A1 in hypoxia-induced inflammatory response in cardiomyocytes via TLR4/ROS/NF-κB pathway

Blockage of DCLK1 in cardiomyocytes suppresses myocardial inflammation and alleviates diabetic cardiomyopathy in streptozotocin-induced diabetic mice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition triggered by diabetes mellitus and can lead to heart failure. Doublecortin-like kinase protein 1 (DCLK1) is a multifunctional protein kinase involved in the regulation of cell proliferation, differentiation, survival, and migration. Current studies on DCLK1 mainly focus on cancer development; however, its role in non-tumor diseases such as DCM is yet to be deciphered. Our analysis revealed that DCLK1 was upregulated in cardiomyocytes of streptozotocin (STZ)-induced type 1 diabetic mouse, suggesting a correlation between DCLK1 and DCM progression. It was further demonstrated that either cardiomyocyte-specific DCLK1 knockout or pharmacological DCLK1 inhibitor DCLK1-IN-1 significantly alleviated cardiac hypertrophy and fibrosis in STZ-induced diabetic mice. RNA-seq analysis of heart tissues revealed that DCLK1 regulated the nuclear factor kappa B (NF-κB)-mediated inflammatory response in DCM. In vitro, DCLK1 activated NF-κB and the inflammatory response by inducing the IKKβ phosphorylation in high-concentration glucose (HG)-challenged cardiomyocytes. DCLK1-IN-1 also prevented HG-induced IKKβ/NF-κB activation and inflammatory injuries in cardiomyocytes. In conclusion, this study highlights the novel role of cardiomyocyte DCLK1 in regulating IKKβ/NF-κB, which aggravates inflammation to promote the pathogenesis of DCM. DCLK1 may serve as a new target for DCM treatment.

Diagnostic value and mechanism of plasma S100A1 protein in acute ischemic stroke: a prospective and observational study

Background

Plasma S100A1 protein is a novel inflammatory biomarker associated with acute myocardial infarction and neurodegenerative disease's pathophysiological mechanisms. This study aimed to determine the levels of this protein in patients with acute ischemic stroke early in the disease progression and to investigate its role in the pathogenesis of acute ischemic stroke.

Methods

A total of 192 participants from hospital stroke centers were collected for the study. Clinically pertinent data were recorded. The volume of the cerebral infarction was calculated according to the Pullicino formula. Multivariate logistic regression analysis was used to select independent influences. ROC curve was used to analyze the diagnostic value of AIS and TIA. The correlation between S100A1, NF-κB p65, and IL-6 levels and cerebral infarction volume was detected by Pearson correlation analysis.

Results

There were statistically significant differences in S100A1, NF-κB p65, and IL-6 among the AIS,TIA, and PE groups (S100A1, [230.96 ± 39.37] vs [185.85 ± 43.24] vs [181.47 ± 27.39], P < 0.001; NF-κB p65, [3.99 ± 0.65] vs [3.58 ± 0.74] vs [3.51 ± 0.99], P = 0.001; IL-6, [13.32 ± 1.57] vs [11.61 ± 1.67] vs [11.42 ± 2.34], P < 0.001). Multivariate logistic regression analysis showed that S100A1 might be an independent predictive factor for the diagnosis of disease (P < 0.001). The AUC of S100A1 for diagnosis of AIS was 0.818 (P < 0.001, 95% CI [0.749-0.887], cut off 181.03, Jmax 0.578, Se 95.0%, Sp 62.7%). The AUC of S100A1 for diagnosis of TIA was 0.720 (P = 0.001, 95% CI [0.592-0.848], cut off 150.14, Jmax 0.442, Se 50.0%, Sp 94.2%). There were statistically significant differences in S100A1, NF-κB p65, and IL-6 among the SCI,MCI, and LCI groups (S100A1, [223.98 ± 40.21] vs [225.42 ± 30.92] vs [254.25 ± 37.07], P = 0.001; NF-κB p65, [3.88 ± 0.66] vs [3.85 ± 0.64] vs [4.41 ± 0.45], P < 0.001; IL-6, [13.27 ± 1.65] vs [12.77 ± 1.31] vs [14.00 ± 1.40], P = 0.007). Plasma S100A1, NF-κB p65, and IL-6 were significantly different from cerebral infarction volume (S100A1, r = 0.259, P = 0.002; NF-κB p65, r = 0.316, P < 0.001; IL-6, r = 0.177, P = 0.036). There was a positive correlation between plasma S100A1 and IL-6 with statistical significance (R = 0.353, P < 0.001). There was no significant positive correlation between plasma S100A1 and NF-κB p65 (R < 0.3), but there was statistical significance (R = 0.290, P < 0.001). There was a positive correlation between IL-6 and NF-κB p65 with statistical significance (R = 0.313, P < 0.001).

Conclusion

S100A1 might have a better diagnostic efficacy for AIS and TIA. S100A1 was associated with infarct volume in AIS, and its level reflected the severity of acute cerebral infarction to a certain extent. There was a correlation between S100A1 and IL-6 and NF-κB p65, and it was reasonable to speculate that this protein might mediate the inflammatory response through the NF-κB pathway during the pathophysiology of AIS.

S100A1 expression is increased in spinal cord injury and promotes inflammation, oxidative stress and apoptosis of PC12 cells induced by LPS via ERK signaling

Spinal cord injury (SCI) is a severe neurological disorder and the molecular mechanisms leading to its poor prognosis remain to be elucidated. S100A1, a mediator of Ca2+ handling of sarcoplasmic reticulum and mitochondrial function, operates as an endogenous danger signal (alarmin) associated with inflammatory response and tissue injury. The aim of the present study was to investigate the expression and biological effects of S100A1 in SCI. A rat model of SCI and a PC12 cell model of lipopolysaccharide (LPS)‑induced inflammation were established to examine S100A1 expression at the mRNA and protein levels. The inflammation level, which was mediated by S100A1, was determined based on inflammatory factor (IL‑1β, IL‑6 and TNF‑α) and anti‑inflammatory factor (IL‑10) expression. The effects of S100A1 on cellular oxidation and anti‑oxidation levels were observed by detecting the levels of reactive oxygen species, superoxide dismutase, catalase activities and nuclear factor erythroid 2‑related factor 2 expression. The protein levels of Bax, Bcl2 and cleaved caspase‑3 were used for the evaluation of the effects of S100A1 on apoptosis. Phosphorylated (p‑)ERK1/2 expression was used to evaluate the effects of S100A1 on ERK signaling. The results revealed that S100A1 expression was significantly upregulated in vivo and in vitro in the PC12 cell model of LPS‑inflammation. The silencing and overexpression of S100A1 helped alleviate and aggravate LPS‑induced inflammation, oxidative stress and apoptosis levels, respectively. S100A1 was found to regulate the ERK signaling pathway positively. An inhibitor of ERK signaling (MK‑8353) partially abolished the promoting effects of the overexpression of S100A1 on inflammation, oxidative stress damage and apoptosis. In conclusion, S100A1 expression was elevated in model of SCI and in the PC12 cell model of LPS‑induced inflammation. Furthermore, the overexpression/silencing S100A1 aggravated/mitigated the inflammation, oxidative stress damage and the apoptosis of LPS‑stimulated PC12 cells via the ERK signaling pathway. The present study revealed the mechanism of S100A1 in SCI, which provided a new theoretic reference for future research on SCI.

miRNA and mRNA expression analysis reveals the effects of continuous heat stress on antibacterial responses to Aeromonas hydrophila lipopolysaccharide (LPS) in grass carp (Ctenopharyngodon idella)

Grass carp (Ctenopharyngodon idella) is the largest economic fish in freshwater culture in China, which is predisposed to infectious diseases under high temperature. Under the background of global warming, the industrialization of the Pearl River Delta region has led to aggravated thermal pollution, which has increasingly serious impacts on the aquatic ecological environment. This will result in more frequent exposure of grass carp to overheated water temperatures. Previous studies have only identified the regulatory genes of fish that respond to pathogens or temperature stress, but the transcriptional response to both is unknown. In this study, the histopathological analysis showed heat stress exacerbated spleen damage induced by Aeromonas hydrophila. The transcriptional responses of the spleens from A. hydrophila lipopolysaccharide (LPS) -injected grass carp undergoing heat stress and at normal temperatures for 6, 24, and 72 h were investigated by mRNA and microRNA sequencing. We identified 28, 20, and 141 differentially expressed (DE) miRNAs and 126, 383, and 4841 DE mRNAs between the two groups after 6, 24, and 72 h, respectively. There were 67 DE genes mainly involved in the cytochrome P450 pathway, antioxidant defense, inflammatory response, pathogen recognition pathway, antigen processing and presentation, and the ubiquitin-proteasome system. There were 5 DE miRNAs involved in regulating apoptosis and inflammation. We further verified 17 DE mRNAs and 5 DE miRNAs using quantitative real-time PCR. Based on miRNAs and mRNAs analysis, continuous heat stress will affect the antibacterial responses of grass carp spleens, resulting in aggravation of spleen injury. Together, these results provide data for further understanding of the decreased tolerance of fish to pathogen infection in persistent high-temperature environments.

Identification of recurrent variants implicated in disease in bicuspid aortic valve patients through whole-exome sequencing

Bicuspid aortic valve (BAV) is the most common congenital heart defect in human beings, with an estimated prevalence in the general population of between 0.5 and 2%. Moreover, BAV is the most common cause of aortic stenosis in the pediatric population. Patients with BAV may have no symptoms for life, and some of them may progress to aortic stenosis. Genetic factors increase the susceptibility and development of BAV. However, the pathogenesis and BAV are still unclear, and more genetic variants are still needed for elucidating the molecular mechanism and stratification of patients. The present study carried out screening of variants implicated in disease in BAV patients. The whole-exome sequencing (WES) was performed in 20 BAV patients and identified 40 different heterozygous missense mutations in 36 genes (MIB2, FAAH, S100A1, RGS16, MAP3K19, NEB, TTN, TNS1, CAND2, CCK, KALRN, ATP10D, SLIT3, ROS1, FABP7, NUP205, IL11RA, NPR2, COL5A1, CUBN, JMJD1C, ANXA7, TRIM8, LGR4, TPCN2, APOA5, GPR84, LRP1, NCOR2, AKAP11, ESRRB, NGB, AKAP13, WWOX, KCNJ12, ARHGEF1). The mutations in these genes were identified as recurrent variants implicated in disease by in silico prediction tool analysis. Nine genes (MIB2, S100A1, TTN, CCK, NUP205, LGR4, NCOR2, ESRRB, and WWOX) among the 36 genes were identified as variants implicated in disease via unanimous agreement of in silico prediction tool analysis and sequenced in an independent cohort of 137 BAV patients to validate the results of WES. BAV patients carrying these variants demonstrated reduced left ventricular ejection fractions (LVEF) (63.8 ± 7.5% vs. 58.4 ± 5.2%, P < 0.001) and larger calcification volume [(1129.3 ± 154) mm³ vs. (1261.8 ± 123) mm³, P < 0.001]. The variants in TTN, NUP205 and NCOR2 genes are significantly associated with reduced LVEF, and the variants in S100A1, LGR4, ESRRB, and WWOX genes are significantly associated with larger calcification volume. We identified a panel of recurrent variants implicated in disease in genes related to the pathogenesis of BAV. Our data speculate that these variants are promising markers for risk stratification of BAV patients with increased susceptibility to aortic stenosis.

Repurposing Multiple-Molecule Drugs for COVID-19-Associated Acute Respiratory Distress Syndrome and Non-Viral Acute Respiratory Distress Syndrome via a Systems Biology Approach and a DNN-DTI Model Based on Five Drug Design Specifications

The coronavirus disease 2019 (COVID-19) epidemic is currently raging around the world at a rapid speed. Among COVID-19 patients, SARS-CoV-2-associated acute respiratory distress syndrome (ARDS) is the main contribution to the high ratio of morbidity and mortality. However, clinical manifestations between SARS-CoV-2-associated ARDS and non-SARS-CoV-2-associated ARDS are quite common, and their therapeutic treatments are limited because the intricated pathophysiology having been not fully understood. In this study, to investigate the pathogenic mechanism of SARS-CoV-2-associated ARDS and non-SARS-CoV-2-associated ARDS, first, we constructed a candidate host-pathogen interspecies genome-wide genetic and epigenetic network (HPI-GWGEN) via database mining. With the help of host-pathogen RNA sequencing (RNA-Seq) data, real HPI-GWGEN of COVID-19-associated ARDS and non-viral ARDS were obtained by system modeling, system identification, and Akaike information criterion (AIC) model order selection method to delete the false positives in candidate HPI-GWGEN. For the convenience of mitigation, the principal network projection (PNP) approach is utilized to extract core HPI-GWGEN, and then the corresponding core signaling pathways of COVID-19-associated ARDS and non-viral ARDS are annotated via their core HPI-GWGEN by KEGG pathways. In order to design multiple-molecule drugs of COVID-19-associated ARDS and non-viral ARDS, we identified essential biomarkers as drug targets of pathogenesis by comparing the core signal pathways between COVID-19-associated ARDS and non-viral ARDS. The deep neural network of the drug–target interaction (DNN-DTI) model could be trained by drug–target interaction databases in advance to predict candidate drugs for the identified biomarkers. We further narrowed down these predicted drug candidates to repurpose potential multiple-molecule drugs by the filters of drug design specifications, including regulation ability, sensitivity, excretion, toxicity, and drug-likeness. Taken together, we not only enlighten the etiologic mechanisms under COVID-19-associated ARDS and non-viral ARDS but also provide novel therapeutic options for COVID-19-associated ARDS and non-viral ARDS.

Toxicokinetics of Arenobufagin and its Cardiotoxicity Mechanism Exploration Based on Lipidomics and Proteomics Approaches in Rats

Arenobufagin (ArBu), one of the main active bufadienolides of toad venom with cardiotonic effect, analgesic effect, and outstanding anti-tumor potentiality, is also a potential cardiotoxic component. In the present study, the cardiac effect of ArBu and its underlying mechanism were explored by integrating data such as heart rates, toxicokinetics, myocardial enzyme and brain natriuretic peptide (BNP) activity, pathological sections, lipidomics and proteomics. Under different doses, the cardiac effects turned out to be different. The oral dose of 60 mg/kg of ArBu sped up the heart rate. However, 120 mg/kg ArBu mainly reduced the heart rate. Over time, they all returned to normal, consisting of the trend of ArBu concentration-time curve. High concentrations of myocardial enzymes and BNP indicated that ArBu inhibited or impaired the cardiac function of rats. Pathological sections of hearts also showed that ArBu caused myocardial fiber disorder and rupture, in which the high-dose group was more serious. At the same time, serum and heart tissue lipidomics were used to explore the changes in body lipid metabolism under different doses. The data indicated a larger difference in the high-dose ArBu group. There were likewise many significant differences in the proteomics of the heart. Furthermore, a multi-layered network was used to integrate the above information to explore the potential mechanism. Finally, 4 proteins that were shown to be significantly and differentially expressed were validated by targeted proteomics using parallel reaction monitoring (PRM) analysis. Our findings indicated that ArBu behaved as a bidirectional regulation of the heart. The potential mechanism of cardiac action was revealed with the increased dose, which provided a useful reference for the safety of clinical application of ArBu.

S100A1 is Involved in Myocardial Injury Induced by Exhaustive Exercise

Many studies have confirmed that exhaustive exercise has adverse effects on the heart by generating reactive oxygen species (ROS). S100A1 calcium-binding protein A1 (S100A1) is a regulator of myocardial contractility and a protector against myocardial injury. However, few studies have investigated the role of S100A1 in the regulation of myocardial injury induced by exhaustive exercise. In the present study, we suggested that exhaustive exercise led to increased ROS, downregulation of S100a1, and myocardial injury. Downregulation of S100a1 promoted exhaustive exercise-induced myocardial injury and overexpression of S100A1 reversed oxidative stress-induced cardiomyocyte injury, indicating S100A1 is a protective factor against myocardial injury caused by exhaustive exercise. We also found that downregulation of S100A1 promoted damage to critical proteins of the mitochondria by inhibiting the expression of Ant1, Pgc1a, and Tfam under exhaustive exercise. Our study indicated S100A1 as a potential prognostic biomarker or therapeutic target to improve the myocardial damage induced by exhaustive exercise and provided new insights into the molecular mechanisms underlying the myocardial injury effect of exhaustive exercise.

S100A1 is a Potential Biomarker for Papillary Thyroid Carcinoma Diagnosis and Prognosis

S100 calcium binding protein A1 (S100A1) is an important member of the S100 family and known to express in a variety of cancers. However, the biological functions of S100A1 in thyroid carcinoma have not been thoroughly studied. In this report, bioinformatics analyses and immunohistochemistry assays were applied to assess the expression profile of S100A1 as well as its relationship with the pathological features and prognosis of papillary thyroid carcinoma (PTC). Meanwhile, functions of S100A1 in PTC cells were analyzed with either in vitro or in vivo experiments. S100A1 was significantly up-regulated in PTC tissues compared with adjacent non-cancerous tissues. S100A1 protein expression was significantly associated with tumor size (p=0.0032) or lymph node metastasis (p=0.0331). More importantly, an elevated S100A1 expression was significantly correlated with a worse recurrence-free survival (RFS) (HR=2.26, p=0.042). Further, knockdown of S100A1 dramatically inhibited cell proliferation and migration as well as increased apoptosis of PTC cells. S100A1 knockdown inhibited tumor progression as seen in in vivo experiments. In terms of mechanism, down-regulation of S100A1 induced yes associated protein (YAP) phosphorylation in the cytoplasm and diminished Hippo/YAP pathway activation. Therefore, S100A1 may serve as a novel oncogene and a promising biomarker for PTC diagnosis and prognosis.

Mechanisms of Systolic Cardiac Dysfunction in PP2A, PP5 and PP2AxPP5 Double Transgenic Mice

As part of our ongoing studies on the potential pathophysiological role of serine/threonine phosphatases (PP) in the mammalian heart, we have generated transgenic mice with cardiac muscle cell-specific overexpression of PP2Acα (PP2A) and PP5 (PP5). For further studies we crossbred PP2A and PP5 mice to obtain PP2AxPP5 double transgenic mice (PP2AxPP5, DT) and compared them with littermate wild-type mice (WT) serving as a control. The mortality of DT mice was greatly enhanced vs. other genotypes. Cardiac fibrosis was noted histologically and mRNA levels of collagen 1α, collagen 3α and fibronectin 1 were augmented in DT. DT and PP2A mice exhibited an increase in relative heart weight. The ejection fraction (EF) was reduced in PP2A and DT but while the EF of PP2A was nearly normalized after β-adrenergic stimulation by isoproterenol, it was almost unchanged in DT. Moreover, left atrial preparations from DT were less sensitive to isoproterenol treatment both under normoxic conditions and after hypoxia. In addition, levels of the hypertrophy markers atrial natriuretic peptide and B-type natriuretic peptide as well as the inflammation markers interleukin 6 and nuclear factor kappa B were increased in DT. PP2A enzyme activity was enhanced in PP2A vs. WT but similar to DT. This was accompanied by a reduced phosphorylation state of phospholamban at serine-16. Fittingly, the relaxation times in left atria from DT were prolonged. In summary, cardiac co-overexpression of PP2A and PP5 were detrimental to animal survival and cardiac function, and the mechanism may involve dephosphorylation of important regulatory proteins but also fibrosis and inflammation.

Nutraceutical, Dietary, and Lifestyle Options for Prevention and Treatment of Ventricular Hypertrophy and Heart Failure

Although well documented drug therapies are available for the management of ventricular hypertrophy (VH) and heart failure (HF), most patients nonetheless experience a downhill course, and further therapeutic measures are needed. Nutraceutical, dietary, and lifestyle measures may have particular merit in this regard, as they are currently available, relatively safe and inexpensive, and can lend themselves to primary prevention as well. A consideration of the pathogenic mechanisms underlying the VH/HF syndrome suggests that measures which control oxidative and endoplasmic reticulum (ER) stress, that support effective nitric oxide and hydrogen sulfide bioactivity, that prevent a reduction in cardiomyocyte pH, and that boost the production of protective hormones, such as fibroblast growth factor 21 (FGF21), while suppressing fibroblast growth factor 23 (FGF23) and marinobufagenin, may have utility for preventing and controlling this syndrome. Agents considered in this essay include phycocyanobilin, N-acetylcysteine, lipoic acid, ferulic acid, zinc, selenium, ubiquinol, astaxanthin, melatonin, tauroursodeoxycholic acid, berberine, citrulline, high-dose folate, cocoa flavanols, hawthorn extract, dietary nitrate, high-dose biotin, soy isoflavones, taurine, carnitine, magnesium orotate, EPA-rich fish oil, glycine, and copper. The potential advantages of whole-food plant-based diets, moderation in salt intake, avoidance of phosphate additives, and regular exercise training and sauna sessions are also discussed. There should be considerable scope for the development of functional foods and supplements which make it more convenient and affordable for patients to consume complementary combinations of the agents discussed here. Research Strategy: Key word searching of PubMed was employed to locate the research papers whose findings are cited in this essay.

Multi-Omics Identifies Circulating miRNA and Protein Biomarkers for Facioscapulohumeral Dystrophy

The development of therapeutics for muscle diseases such as facioscapulohumeral dystrophy (FSHD) is impeded by a lack of objective, minimally invasive biomarkers. Here we identify circulating miRNAs and proteins that are dysregulated in early-onset FSHD patients to develop blood-based molecular biomarkers. Plasma samples from clinically characterized individuals with early-onset FSHD provide a discovery group and are compared to healthy control volunteers. Low-density quantitative polymerase chain reaction (PCR)-based arrays identify 19 candidate miRNAs, while mass spectrometry proteomic analysis identifies 13 candidate proteins. Bioinformatic analysis of chromatin immunoprecipitation (ChIP)-seq data shows that the FSHD-dysregulated DUX4 transcription factor binds to regulatory regions of several candidate miRNAs. This panel of miRNAs also shows ChIP signatures consistent with regulation by additional transcription factors which are up-regulated in FSHD (FOS, EGR1, MYC, and YY1). Validation studies in a separate group of patients with FSHD show consistent up-regulation of miR-100, miR-103, miR-146b, miR-29b, miR-34a, miR-454, miR-505, and miR-576. An increase in the expression of S100A8 protein, an inflammatory regulatory factor and subunit of calprotectin, is validated by Enzyme-Linked Immunosorbent Assay (ELISA). Bioinformatic analyses of proteomics and miRNA data further support a model of calprotectin and toll-like receptor 4 (TLR4) pathway dysregulation in FSHD. Moving forward, this panel of miRNAs, along with S100A8 and calprotectin, merit further investigation as monitoring and pharmacodynamic biomarkers for FSHD.

Overexpression of protein phosphatase 5 in the mouse heart: Reduced contractility but increased stress tolerance - Two sides of the same coin?

The pathophysiological mechanisms of sepsis-induced cardiac dysfunction are largely unknown. The Toll-like receptor 4 (TLR4) is expressed in cardiac myocytes and is involved in bacterial endotoxin-mediated inflammatory disorders. TLR4 signaling leads to activation of the nuclear factor kappa B followed by increased expression of cytokines. Several protein phosphatases including PP2Cβ, PP2A or PP1 are known to act as regulators of this signaling pathway. Here, we examined the role of PP5 for the inflammatory response to the bacterial endotoxin lipopolysaccharide in the heart using a transgenic mouse model with cardiac myocyte directed overexpression of PP5. In these transgenic mice, basal cardiac contractility was reduced, in vivo as well as in vitro, but LPS-induced cardiac dysfunction was less pronounced compared to wild type mice. Quantitative RT-PCR suggested an attenuated NF-κB signaling in the heart and cardiac expression of heat shock protein 25 (HSP25) was increased in PP5 transgenic mice. From our data we assume that PP5 increases stress tolerance of cardiac myocytes by downregulation of NF-κB signaling and upregulation of HSP25 expression.

Interleukin-37: The Effect of Anti-Inflammatory Response in Human Coronary Artery Endothelial Cells

Interleukin-37 (IL-37) is unique in the IL-1 family since it broadly suppresses innate immunity and elevates in humans with inflammatory and autoimmune diseases. IL-37 shows definite groups and transcripts for human IL37 gene, but it is still not completely understood the effect and mechanisms of inflammatory response in endothelial cells. It is well accepted that endothelial dysfunction caused by inflammation is a key initiating event in atherosclerotic plaque formation, which leads to the occurrence and development of the cardiovascular adverse events in clinical since the inflammatory responses of endothelial cells could induce and enhance the deposition of extensive lipid and the formation of atherosclerotic plaque in the intima. Thus, it is essential to investigate the role and potential mechanisms in endothelial inflammatory response to prevent the formation and development of many cardiovascular diseases including atherosclerosis. So far, the recent studies have revealed that IL-37 is able to inhibit inflammatory response by suppressing the TLR2-NF-κB-ICAM-1 pathway intracellularly in human coronary artery endothelial cells (HCAECs). Further, the role of IL-37 may be related to the IL-18 pathway extracellularly and involved in the adhesion and transmigration of neutrophils in HCAECs.

Elevated plasma S100A1 level is a risk factor for ST-segment elevation myocardial infarction and associated with post-infarction cardiac function

AIM

To investigate the association between plasma S100A1 level and ST-segment elevation myocardial infarction (STEMI) and potential significance of S100A1 in post-infarction cardiac function.

METHODS

We examined the plasma S100A1 level in 207 STEMI patients (STEMI group) and 217 clinically healthy subjects for routine physical examination without a history of coronary artery disease (Control group). Baseline characteristics and concentrations of relevant biomarkers were compared. The relationship between S100A1 and other plasma biomarkers was detected using correlation analysis. The predictive role of S100A1 on occurrence of STEMI was then assessed using multivariate ordinal regression model analysis after adjusting for other covariates.

RESULTS

The plasma S100A1 level was found to be significantly higher (P<0.001) in STEMI group (3197.7±1576.0 pg/mL) than in Control (1423.5±1315.5 pg/mL) group. Furthermore, the correlation analysis demonstrated plasma S100A1 level was significantly associated correlated with hypersensitive cardiac troponin T (hs-cTnT) (r = 0.32; P < 0.001), creatine kinase MB (CK-MB) (r = 0.42, P < 0.001), left ventricular eject fraction (LVEF) (r = -0.12, P = 0.01), N-terminal prohormone of brain natriuretic peptide (NT-proBNP) (r = 0.61; P < 0.001) and hypersensitive C reactive protein (hs-CRP) (r = 0.38; P < 0.001). Moreover, the enrolled subjects who with a S100A1 concentration ≤ 1965.9 pg/mL presented significantly better cardiac function than the rest population. Multivariate Logistic regression analysis revealed that S100A1 was an independent predictor for STEMI patients (OR: 0.671, 95% CI 0.500-0.891, P<0.001). In addition, higher S100A1 concentration (> 1965.9 pg/mL) significantly increased the risk of STEMI as compared with the lower level (OR: 6.925; 95% CI: 4.15-11.375; P<0.001).

CONCLUSION

These results indicated that the elevated plasma S100A1 level is an important predictor of STEMI in combination with several biomarkers and also potentially reflects the cardiac function following the acute coronary ischemia.

A multiomics analysis of S100 protein family in breast cancer

The S100 gene family is the largest subfamily of calcium binding proteins of EF-hand type, expressed in tissue and cell-specific manner, acting both as intracellular regulators and extracellular mediators. There is a growing interest in the S100 proteins and their relationships with different cancers because of their involvement in a variety of biological events closely related to tumorigenesis and cancer progression. However, the collective role and the possible coordination of this group of proteins, as well as the functional implications of their expression in breast cancer (BC) is still poorly known. We previously reported a large-scale proteomic investigation performed on BC patients for the screening of multiple forms of S100 proteins. Present study was aimed to assess the functional correlation between protein and gene expression patterns and the prognostic values of the S100 family members in BC. By using data mining, we showed that S100 members were collectively deregulated in BC, and their elevated expression levels were correlated with shorter survival and more aggressive phenotypes of BC (basal like, HER2 enriched, ER-negative and high grading). Moreover a multi-omics functional network analysis highlighted the regulatory effects of S100 members on several cellular pathways associated with cancer and cancer progression, expecially immune response and inflammation. Interestingly, for the first time, a pathway analysis was successfully applied on different omics data (transcriptomics and proteomics) revealing a good convergence between pathways affected by S100 in BC. Our data confirm S100 members as a promising panel of biomarkers for BC prognosis.

Downregulation of TLR4 by miR-181a Provides Negative Feedback Regulation to Lipopolysaccharide-Induced Inflammation

Acute lung injury (ALI) is a progressive clinical disease with a high mortality rate, and characterized by an excessive uncontrolled inflammatory response. MicroRNAs (miRNAs) play a critical role in various human inflammatory diseases, and have been recognized as important regulators of inflammation. However, the regulatory mechanisms mediated by miRNAs involved in Lipopolysaccharide (LPS)-induced inflammation in ALI remain hazy. In this study, we found that miR-181a expression in the lung tissues of ALI mice and LPS-stimulated RAW 264.7 macrophages is dramatically reduced. We also show that over-expression of miR-181a significantly decreased the production of inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, whereas inhibition of miR-181a reversed this decrease. Moreover, miR-181a inhibits NF-κB activation and accumulation of reactive oxygen species (ROS) by targeting TLR4 expression. We further verify that miR-181a suppresses TLR4 expression by binding directly to the 3′-UTR of TLR4. Therefore, we provide the first evidence for the negative regulation of miR-181a in LPS-induced inflammation via the suppression of ROS generation and TLR4-NF-κB pathway.

Atorvastatin alleviates cardiomyocyte apoptosis by suppressing TRB3 induced by acute myocardial infarction and hypoxia

BACKGROUND/PURPOSE

TRB3 (tribbles 3), an apoptosis-regulated gene, increases during endoplasmic reticulum stress. Hypoxia can induce inflammatory mediators and apoptosis in cardiomyocytes. However, the expression of TRB3 in cardiomyocyte apoptosis under hypoxia is not thoroughly known. We investigated the regulation mechanism of TRB3 expression and apoptosis induced by hypoxia in cardiomyocytes.

METHODS

An in vivo model of acute myocardial infarction (AMI) was applied in adult Wistar rats to induce myocardial hypoxia. Rat neonatal cardiomyocytes were subjected to 2.5% O₂ to induce hypoxia.

RESULTS

The expression of TRB3 was evaluated in cultured rat neonatal cardiomyocytes subjected to hypoxia. Hypoxia significantly enhanced TRB3 protein and mRNA expression. Adding c-jun N-terminal kinase (JNK) inhibitor SP600125, JNK small interfering RNA (siRNA), tumor necrosis factor-α (TNF-α) antibody, and atorvastatin 30 minutes before hypoxia reversed the induction of TRB3 protein. A gel-shift assay showed the DNA-binding activity of growth arrest and DNA damage-inducible gene 153 (GADD153), which increased after hypoxia. Hypoxia increased, whereas the TRB3-mut plasmid, SP600125, and TNF-α antibody abolished the hypoxia-induced TRB3 promoter activity. Hypoxia increased the secretion of TNF-α from cardiomyocytes. Exogenous administration of TNF-α recombinant protein to the cardiomyocytes without hypoxia increased TRB3 protein expression, similar to that observed after hypoxia. Hypoxia-induced cardiomyocyte apoptosis is inhibited by TRB3 siRNA, the TNF-α antibody, and atorvastatin. Atorvastatin reduced the TRB3 expression and cardiomyocyte apoptosis induced by AMI. Hypoxia induces TRB3 through TNF-α, JNK, and the GADD153 pathway.

CONCLUSION

Treatment of atorvastatin inhibits the expression of TRB3 and cardiomyocyte apoptosis induced by AMI and hypoxia.