Formal modelling of toll like receptor 4 and JAK/STAT signalling pathways: insight into the roles of SOCS-1, interferon-β and proinflammatory cytokines in sepsis

Human milk oligosaccharides 3'-sialyllactose and 6'-sialyllactose attenuate LPS-induced lung injury by inhibiting STAT1 and NF-κB signaling pathways

Acute lung injury (ALI) is the leading cause of respiratory diseases induced by uncontrolled inflammation and cell death. Lipopolysaccharide (LPS) is a major trigger of ALI in the progression through macrophage differentiation and the accelerated release of pro-inflammatory cytokines. The present study aimed to investigate the protective effects of human milk oligosaccharides, specifically 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL), on LPS-induced ALI and elucidate their underlying signaling pathways. The inhibitory effects of 3'-SL and 6'-SL on inflammation were evaluated using LPS-treated RAW 264.7 macrophages. To establish the ALI model, mice were treated with 10 mg/kg LPS for 24 h. Histological changes in the lung tissues were assessed using hematoxylin and eosin staining and immunofluorescence. LPS causes thickening of the alveolar wall infiltration of immune cells in lung tissues and increased serum levels of TNF-α, IL-1β, and GM-CSF. However, these effects were significantly alleviated by 100 mg/kg of 3'-SL and 6'-SL. Consistent with the inhibitory effects of 3'-SL and 6'-SL on LPS-induced pro-inflammatory cytokine secretion in serum, 3'-SL and 6'-SL suppressed mRNA expression of TNF-α, IL-1β, MCP-1, iNOS, and COX2 in LPS-induced RAW 264.7 cells. Mechanistically, 3'-SL and 6'-SL abolished LPS-mediated phosphorylation of NF-κB and STAT1. Interestingly, fludarabine treatment, a STAT1 inhibitor, did not affect LPS-mediated NF-κB phosphorylation. In summary, 3'-SL and 6'-SL protect LPS-induced macrophage activation and ALI through the STAT1 and NF-κB signaling pathways.

Modelling and analysis of the complement system signalling pathways: roles of C3, C5a and pro-inflammatory cytokines in SARS-CoV-2 infection

The complement system is an essential part of innate immunity. It is activated by invading pathogens causing inflammation, opsonization, and lysis via complement anaphylatoxins, complement opsonin's and membrane attack complex (MAC), respectively. However, in SARS-CoV-2 infection overactivation of complement system is causing cytokine storm leading to multiple organs damage. In this study, the René Thomas kinetic logic approach was used for the development of biological regulatory network (BRN) to model SARS-CoV-2 mediated complement system signalling pathways. Betweenness centrality analysis in cytoscape was adopted for the selection of the most biologically plausible states in state graph. Among the model results, in strongly connected components (SCCs) pro-inflammatory cytokines (PICyts) oscillatory behaviour between recurrent generation and downregulation was found as the main feature of SARS-CoV-2 infection. Diversion of trajectories from the SCCs leading toward hyper-inflammatory response was found in agreement with in vivo studies that overactive innate immunity response caused PICyts storm during SARS-CoV-2 infection. The complex of negative regulators FI, CR1 and DAF in the inhibition of complement peptide (C5a) and PICyts was found desirable to increase immune responses. In modelling role of MAC and PICyts in lowering of SARS-CoV-2 titre was found coherent with experimental studies. Intervention in upregulation of C5a and PICyts by C3 was found helpful in back-and-forth variation of signalling pattern linked with the levels of PICyts. Moreover, intervention in upregulation of PICyts by C5a was found productive in downregulation of all activating factors in the normal SCCs. However, the computational model predictions require experimental studies to be validated by exploring the activation role of C3 and C5a which could change levels of PICyts at various phases of SARS-CoV-2 infection.

Efficacy and Safety of Tofacitinib in Patients with Polymyalgia Rheumatica (EAST PMR): An open-label randomized controlled trial

BACKGROUND

Polymyalgia rheumatica (PMR) is a common inflammatory disease in elderly persons whose mechanism of pathogenesis has not been elucidated. Glucocorticoids are the main first-line treatments but result in numerous side effects. Therefore, there is a need to explore pathogenetic factors and identify possible glucocorticoid-sparing agents. We aimed to study the pathogenetic features of the disease and assess the efficacy and safety of Janus tyrosine kinase (JAK)-inhibitor tofacitinib in patients with PMR.

METHODS AND FINDINGS

We recruited treatment-naïve PMR patients from the First Affiliated Hospital, Zhejiang University School of Medicine, between September 2020 and September 2022. In the first cohort, we found that the gene expression patterns of peripheral blood mononuclear cells (PBMCs) in 11 patients (10 female, 1 male, age 68.0 ± 8.3) with newly diagnosed PMR were significantly different from 20 healthy controls (17 female, 3 male, age 63.7 ± 9.8) by RNA sequencing. Inflammatory response and cytokine-cytokine receptor interaction were the most notable pathways affected. We observed marked increases in expression of IL6R, IL1B, IL1R1, JAK2, TLR2, TLR4, TLR8, CCR1, CR1, S100A8, S100A12, and IL17RA, which could trigger JAK signaling. Furthermore, tofacitinib suppressed the IL-6R and JAK2 expression of CD4+T cells from patients with PMR in vitro. In the second cohort, patients with PMR were randomized and treated with tofacitinib or glucocorticoids (1/1) for 24 weeks. All PMR patients underwent clinical and laboratory examinations at 0, 4, 8, 12, 16, 20, and 24 weeks, and PMR activity disease scores (PMR-AS) were calculated. The primary endpoint was the proportion of patients with PMR-AS ≤10 at weeks 12 and 24. Secondary endpoints: PMR-AS score, c-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) at weeks 12 and 24. Thirty-nine patients with newly diagnosed PMR received tofacitinib, and 37 patients received glucocorticoid. Thirty-five patients (29 female, 6 male, age 64.4 ± 8.4) and 32 patients (23 female, 9 male, age 65.3 ± 8.7) patients completed the 24-week intervention, respectively. There were no statistically significant differences in primary or secondary outcomes. At weeks 12 and 24, all patients in both groups had PMR-AS <10. PMR-AS, CRP, and ESR were all significantly decreased in both groups. No severe adverse events were observed in either group. Study limitations included the single-center study design with a short observation period.

CONCLUSIONS

We found that JAK signaling was involved in the pathogenesis of PMR. Tofacitinib effectively treated patients with PMR as glucocorticoid does in this randomized, monocenter, open-label, controlled trial (ChiCTR2000038253).

TRIAL REGISTRATION

This investigator-initiated clinical trial (IIT) had been registered on the website (http://www.chictr.org.cn/, ChiCTR2000038253).

The Role of Noncoding RNA in Airway Allergic Diseases through Regulation of T Cell Subsets

Allergic rhinitis and asthma are common airway allergic diseases, the incidence of which has increased annually in recent years. The human body is frequently exposed to allergens and environmental irritants that trigger immune and inflammatory responses, resulting in altered gene expression. Mounting evidence suggested that epigenetic alterations were strongly associated with the progression and severity of allergic diseases. Noncoding RNAs (ncRNAs) are a class of transcribed RNA molecules that cannot be translated into polypeptides and consist of three major categories, microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). Previous studies showed that ncRNAs were involved in the physiopathological mechanisms of airway allergic diseases and contributed to their occurrence and development. This article reviews the current state of understanding of the role of noncoding RNAs in airway allergic diseases, highlights the limitations of recent studies, and outlines the prospects for further research to facilitate the clinical translation of noncoding RNAs as therapeutic targets and biomarkers.

Mesenchymal stromal cells-derived extracellular vesicles reprogramme macrophages in ARDS models through the miR-181a-5p-PTEN-pSTAT5-SOCS1 axis

RATIONALE

A better understanding of the mechanism of action of mesenchymal stromal cells (MSCs) and their extracellular vesicles (EVs) is needed to support their use as novel therapies for acute respiratory distress syndrome (ARDS). Macrophages are important mediators of ARDS inflammatory response. Suppressor of cytokine signalling (SOCS) proteins are key regulators of the macrophage phenotype switch. We therefore investigated whether SOCS proteins are involved in mediation of the MSC effect on human macrophage reprogramming.

METHODS

Human monocyte-derived macrophages (MDMs) were stimulated with lipopolysaccharide (LPS) or plasma samples from patients with ARDS (these samples were previously classified into hypo-inflammatory and hyper-inflammatory phenotype) and treated with MSC conditioned medium (CM) or EVs. Protein expression was measured by Western blot. EV micro RNA (miRNA) content was determined by miRNA sequencing. In vivo: LPS-injured C57BL/6 mice were given EVs isolated from MSCs in which miR-181a had been silenced by miRNA inhibitor or overexpressed using miRNA mimic.

RESULTS

EVs were the key component of MSC CM responsible for anti-inflammatory modulation of human macrophages. EVs significantly reduced secretion of tumour necrosis factor-α and interleukin-8 by LPS-stimulated or ARDS plasma-stimulated MDMs and this was dependent on SOCS1. Transfer of miR-181a in EVs downregulated phosphatase and tensin homolog (PTEN) and subsequently activated phosphorylated signal transducer and activator of transcription 5 (pSTAT5) leading to upregulation of SOCS1 in macrophages. In vivo, EVs alleviated lung injury and upregulated pSTAT5 and SOCS1 expression in alveolar macrophages in a miR181-dependent manner. Overexpression of miR-181a in MSCs significantly enhanced therapeutic efficacy of EVs in this model.

CONCLUSION

miR-181a-PTEN-pSTAT5-SOCS1 axis is a novel pathway responsible for immunomodulatory effect of MSC EVs in ARDS.

Application of Sensitivity Analysis to Discover Potential Molecular Drug Targets

Mathematical modeling of signaling pathways and regulatory networks has been supporting experimental research for some time now. Sensitivity analysis, aimed at finding model parameters whose changes yield significantly altered cellular responses, is an important part of modeling work. However, sensitivity methods are often directly transplanted from analysis of technical systems, and thus, they may not serve the purposes of analysis of biological systems. This paper presents a novel sensitivity analysis method that is particularly suited to the task of searching for potential molecular drug targets in signaling pathways. Using two sample models of pathways, p53/Mdm2 regulatory module and IFN-β-induced JAK/STAT signaling pathway, we show that the method leads to biologically relevant conclusions, identifying processes suitable for targeted pharmacological inhibition, represented by the reduction of kinetic parameter values. That, in turn, facilitates subsequent search for active drug components.

Scaffold compound L971 exhibits anti-inflammatory activities through inhibition of JAK/STAT and NFκB signalling pathways

JAK/STAT and NFκB signalling pathways play essential roles in regulating inflammatory responses, which are important pathogenic factors of various serious immune-related diseases, and function individually or synergistically. To find prodrugs that can treat inflammation, we performed a preliminary high-throughput screening of 18 840 small molecular compounds and identified scaffold compound L971 which significantly inhibited JAK/STAT and NFκB driven luciferase activities. L971 could inhibit the constitutive and stimuli-dependent activation of STAT1, STAT3 and IκBα and could significantly down-regulate the proinflammatory gene expression in mouse peritoneal macrophages stimulated by LPS. Gene expression profiles upon L971 treatment were determined using high-throughput RNA sequencing, and significant differentially up-regulated and down-regulated genes were identified by DESeq analysis. The bioinformatic studies confirmed the anti-inflammatory effects of L971. Finally, L971 anti-inflammatory character was further verified in LPS-induced sepsis shock mouse model in vivo. Taken together, these data indicated that L971 could down-regulate both JAK/STAT and NFκB signalling activities and has the potential to treat inflammatory diseases such as sepsis shock.

Imperatorin Interferes with LPS Binding to the TLR4 Co-Receptor and Activates the Nrf2 Antioxidative Pathway in RAW264.7 Murine Macrophage Cells

Imperatorin (IMP) could downregulate several inflammatory transcription factor signaling pathways. Some studies have pointed out that IMP could interfere with toll-like receptor 4 (TLR4) signaling. This study evaluates how IMP interferes with the TLR4 co-receptors signaling through the protein-ligand docking model, Western blotting, immunofluorescence (IF), and atomic force microscopy (AFM) assays in lipopolysaccharide (LPS) stimulated macrophage-like RAW264.7 cells in vitro. The results of the protein-ligand docking demonstrate that IMP interferes with LPS binding to the LPS-binding protein (LBP), the cluster of differentiation 14 (CD14), and the toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD-2) co-receptors in LPS-stimulated RAW264.7 cells. Compared with TLR4 antagonist CLI-095 or dexamethasone, IMP could suppress the protein expressions of LBP, CD14, and TLR4/MD-2 in LPS-stimulated cells. Furthermore, the three-dimensional (3D) image assay of the AFM showed IMP could prevent the LPS-induced morphological change in RAW264.7 cells. Additionally, IMP could activate the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, and it increased the antioxidative protein expression of heme oxygenase-1 (HO-1), superoxidase dismutase (SOD), and catalase (CAT). Our results are the first to reveal that the anti-inflammatory effect of IMP interferes with LPS binding to TLR4 co-receptor signaling and activates the antioxidative Nrf2 signaling pathway.

The role of circulating monocytes and JAK inhibition in the infectious-driven inflammatory response of myelofibrosis

Myelofibrosis (MF) is characterized by chronic inflammation and hyper-activation of the JAK-STAT pathway. Infections are one of the main causes of morbidity/mortality. Therapy with Ruxolitinib (RUX), a JAK1/2 inhibitor, may further increase the infectious risk. Monocytes are critical players in inflammation/immunity through cytokine production and release of bioactive extracellular vesicles. However, the functional behavior of MF monocytes, particularly during RUX therapy, is still unclear. In this study, we found that monocytes from JAK2V617F-mutated MF patients show an altered expression of chemokine (CCR2, CXCR3, CCR5) and cytokine (TNF-α-R, IL10-R, IL1β-R, IL6-R) receptors. Furthermore, their ability to produce and secrete free and extracellular vesicles-linked cytokines (IL1β, TNF-α, IL6, IL10) under lipopolysaccharides (LPS) stimulation is severely impaired. Interestingly, monocytes from RUX-treated patients show normal level of chemokine, IL10, IL1β, and IL6 receptors together with a restored ability to produce intracellular and to secrete extracellular vesicles-linked cytokines after LPS stimulation. Conversely, RUX therapy does not normalize TNF-R1/2 receptors expression and the LPS-driven secretion of free pro/anti-inflammatory cytokines. Accordingly, upon LPS stimulation, in vitro RUX treatment of monocytes from MF patients increases their secretion of extracellular vesicles-linked cytokines but inhibits the secretion of free pro/anti-inflammatory cytokines. In conclusion, we demonstrated that in MF the infection-driven response of circulating monocytes is defective. Importantly, RUX promotes their infection-driven cytokine production suggesting that infections following RUX therapy may not be due to monocyte failure. These findings contribute to better interpreting the immune vulnerability of MF and to envisaging strategies to improve the infection-driven immune response.

Deciphering the expression dynamics of ANGPTL8 associated regulatory network in insulin resistance using formal modelling approaches

ANGPTL8 is a recently identified novel hormone which regulates both glucose and lipid metabolism. The increase in ANGPTL8 during compensatory insulin resistance has been recently reported to improve glucose tolerance and a part of cytoprotective metabolic circuit. However, the exact signalling entities and dynamics involved in this process have remained elusive. Therefore, the current study was conducted with a specific aim to model the regulation of ANGPTL8 with emphasis on its role in improving glucose tolerance during insulin resistance. The main contribution of this study is the construction of a discrete model (based on kinetic logic of René Thomas) and its equivalent Stochastic Petri Net model of ANGPTL8 associated Biological Regulatory Network (BRN) which can predict its dynamic behaviours. The predicted results of these models are in‐line with the previous experimental observations and provide comprehensive insights into the signalling dynamics of ANGPTL8 associated BRN. The authors’ results support the hypothesis that ANGPTL8 plays an important role in supplementing the insulin signalling pathway during insulin resistance and its loss can aggravate the pathogenic process by quickly leading towards Diabetes Mellitus. The results of this study have potential therapeutic implications for treatment of Diabetes Mellitus and are suggestive of its potential as a glucose‐lowering agent.

Transcription analysis of the response of the porcine adrenal cortex to a single subclinical dose of lipopolysaccharide from Salmonella Enteritidis

Lipopolysaccharide (LPS) is a bacterial endotoxin which can participate in the induction of inflammatory responses. LPS may also play a significant role in some neurodegenerative, oncological and metabolic disorders. The aim of the current study was to determine the effect of a subclinical low single dose of LPS from Salmonella Enteritidis administrated in vivo on the transcriptome of porcine adrenal cortex cells, especially gene expression levels, long non-coding RNA (lncRNA) profiles, alternative splicing events and RNA editing sites using RNA-seq technology. The subclinical dose of LPS changed the expression of 354 genes, 27 lncRNA loci and other unclassified RNAs. An analysis of alternative splicing events revealed 104 genes with differentially expressed splice junction sites, and the single nucleotide variant calling approach supported the identification of 376 canonical RNA editing candidates and 7249 allele-specific expression variants. The obtained results suggest that the RIG-I-like receptor signaling pathway, may play a more important role than the Toll-like signaling pathway after the administration of a subclinical dose of LPS. Single subclinical dose of LPS can affect the expression profiles of genes coding peptide hormones, steroidogenic enzymes and transcriptional factors, and modulate the endocrine functions of the gland.

Logical modelling reveals the PDC-PDK interaction as the regulatory switch driving metabolic flexibility at the cellular level

BACKGROUND

Metabolic flexibility is the ability of an organism to switch between substrates for energy metabolism, in response to the changing nutritional state and needs of the organism. On the cellular level, metabolic flexibility revolves around the tricarboxylic acid cycle by switching acetyl coenzyme A production from glucose to fatty acids and vice versa. In this study, we modelled cellular metabolic flexibility by constructing a logical model connecting glycolysis, fatty acid oxidation, fatty acid synthesis and the tricarboxylic acid cycle, and then using network analysis to study the behaviours of the model.

RESULTS

We observed that the substrate switching usually occurs through the inhibition of pyruvate dehydrogenase complex (PDC) by pyruvate dehydrogenase kinases (PDK), which moves the metabolism from glycolysis to fatty acid oxidation. Furthermore, we were able to verify four different regulatory models of PDK to contain known biological observations, leading to the biological plausibility of all four models across different cells and conditions.

CONCLUSION

These results suggest that the cellular metabolic flexibility depends upon the PDC-PDK regulatory interaction as a key regulatory switch for changing metabolic substrates.

Exosomal miRNA-19b-3p of tubular epithelial cells promotes M1 macrophage activation in kidney injury

Tubulointerstitial inflammation is a common characteristic of acute and chronic kidney injury. However, the mechanism by which the initial injury of tubular epithelial cells (TECs) drives interstitial inflammation remains unclear. This paper aims to explore the role of exosomal miRNAs derived from TECs in the development of tubulointerstitial inflammation. Global microRNA(miRNA) expression profiling of renal exosomes was examined in a LPS induced acute kidney injury (AKI) mouse model and miR-19b-3p was identified as the miRNA that was most notably increased in TEC-derived exosomes compared to controls. Similar results were also found in an adriamycin (ADR) induced chronic proteinuric kidney disease model in which exosomal miR-19b-3p was markedly released. Interestingly, once released, TEC-derived exosomal miR-19b-3p was internalized by macrophages, leading to M1 phenotype polarization through targeting NF-κB/SOCS-1. A dual-luciferase reporter assay confirmed that SOCS-1 was the direct target of miR-19b-3p. Importantly, the pathogenic role of exosomal miR-19b-3p in initiating renal inflammation was revealed by the ability of adoptively transferred of purified TEC-derived exosomes to cause tubulointerstitial inflammation in mice, which was reversed by inhibition of miR-19b-3p. Clinically, high levels of miR-19b-3p were found in urinary exosomes and were correlated with the severity of tubulointerstitial inflammation in patients with diabetic nephropathy. Thus, our studies demonstrated that exosomal miR-19b-3p mediated the communication between injured TECs and macrophages, leading to M1 macrophage activation. The exosome/miR-19b-3p/SOCS1 axis played a critical pathologic role in tubulointerstitial inflammation, representing a new therapeutic target for kidney disease.

Ulinastatin protects rats from sepsis-induced acute lung injury by suppressing the JAK-STAT3 pathway

Sepsis is usually accompanied by pulmonary inflammations, leading to acute lung injury. During this process, endogenous factors that play a regulatory role could be exploited to therapeutically alleviate such lethal tissue injury. Here, we showed that ulinastatin (UTI) administration could reduce lung tissue necrosis and swelling during sepsis in rats. UTI treatment also decreased the levels of inflammatory mediators both in the lung and in the serum. Mechanistically, we showed that the phosphorylation levels of JAK2 and STAT3 in the lung of UTI-treated rats were lower than control rats and were correlated with the decreased levels of inflammatory mediators. Taken together, these results demonstrate the protective role of UTI in sepsis-induced acute lung injury.

Leptin Functions in Infectious Diseases

Leptin, a pleiotropic protein has long been recognized to play an important role in the regulation of energy homeostasis, metabolism, neuroendocrine function, and other physiological functions through its effects on the central nervous system (CNS) and peripheral tissues. Leptin is secreted by adipose tissue and encoded by the obese (ob) gene. Leptin acts as a central mediator which regulates immunity as well as nutrition. Importantly, leptin can modulate both innate and adaptive immune responses. Leptin deficiency/resistance is associated with dysregulation of cytokine production, increased susceptibility toward infectious diseases, autoimmune disorders, malnutrition and inflammatory responses. Malnutrition induces a state of immunodeficiency and an inclination to death from communicable diseases. Infectious diseases are the disease of poor who invariably suffer from malnutrition that could result from reduced serum leptin levels. Thus, leptin has been placed at the center of many interrelated functions in various pathogenic conditions, such as bacterial, viruses and parasitic infections. We review herein, the recent advances on the role of leptin in malnutrition in pathogenesis of infectious diseases with a particular emphasis on parasitic diseases such as Leishmaniasis, Trypanosomiasis, Amoebiasis, and Malaria.

Model-based in silico analysis of the PI3K/Akt pathway: the elucidation of cross-talk between diabetes and breast cancer

BACKGROUND

A positive association between diabetes and breast cancer has been identified by various epidemiological and clinical studies. However, the possible molecular interactions between the two heterogeneous diseases have not been fully determined yet. There are several underlying mechanisms which may increase the risk of breast cancer in diabetic patients.

INTRODUCTION

In this study, we focused on the role of O-GlcNAc transferase (OGT) enzyme in the regulation of phosphatidylinositol-3 kinase (PI3K) pathway through activation/deactivation of Akt protein. The efficiency of insulin signaling in adipocytes is reduced as a result of OGT overexpression which further attenuates Akt signaling; as a result, the efficiency of insulin signaling is reduced by downregulation of insulin-responsive genes. On the other hand, increased expression of OGT results in Akt activation in breast cancer cells, leading to enhanced cell proliferation and inhibition of the apoptosis. However, the interplay amongst these signaling pathways is still under investigation.

METHODS

In this study, we used Petri nets (PNs) to model and investigate the role of PI3K and OGT pathways, acting as key players in crosstalk between diabetes and breast cancer, resulting in progression of these chronic diseases. Moreover, in silico perturbation experiments were applied on the model to analyze the effects of anti-cancer agents (shRNA and BZX) and anti-diabetic drug (Metformin) on the system.

RESULTS

Our PN model reflects the alterations in protein expression and behavior and the correlation between breast cancer and diabetes. The analysis proposed two combination therapies to combat breast cancer progression in diabetic patients including combination of OGTmRNA silencing and OGT inhibitor (BZX) as first combination and BZX and Metformin as the second.

CONCLUSION

The PN model verified that alterations in O-GlcNAc signaling affect both insulin resistance and breast cancer. Moreover, the combination therapy for breast cancer patients consisting of anti-diabetic drugs such as Metformin along with OGT inhibitors, for example BZX, can produce better treatment regimens.

MicroRNA-30e promotes hepatocyte proliferation and inhibits apoptosis in cecal ligation and puncture-induced sepsis through the JAK/STAT signaling pathway by binding to FOSL2

INTRODUCTION

Hepatocyte proliferation and apoptosis are critical cellular behaviors in rat liver as a result of a liver injury. Herein, we performed this study in order to evaluate the role of miR-30e and its target Fos-Related Antigen-2 (FOSL2) in septic rats through the JAK/STAT signaling pathway.

METHODS

Rat models of sepsis were induced by cecal ligation and puncture. Enzyme-linked immunosorbent assay (ELISA) was performed to access serum levels of lipopolysaccharide (LPS), inflammatory factors, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) to confirm the successful establishment of the model. The hepatocytes were subject to miR-30e mimics, miR-30e inhibitors or siRNA-FOSL2. The expressions of miR-30e, FOSL2, apoptosis- and, JAK/STAT signaling pathway-related genes in liver tissues and hepatocytes were determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. MTT assay and flow cytometry were performed to evaluate hepatocyte viability and apoptosis, respectively.

RESULTS

The results obtained revealed that in the septic rats, serum levels of inflammatory factors, LPS, ALT and AST, as well as the expression of FOSL2 were elevated and the JAK/STAT signaling pathway was activated, while there was a reduction in the expression of miR-30e. An initial bioinformatics prediction followed by a confirmatory dual-luciferase reporter assay determined that miR-30e targeted and negatively regulated FOSL2 expression. MiR-30e inhibited the activation of JSK2/STAT3 signaling pathway by reducing FOSL2 expression, while miR-30e enhanced hepatocyte proliferation and decreased hepatocyte cell apoptosis in septic rats.

CONCLUSION

These findings indicated that miR-30e may serve as an independent therapeutic target for sepsis, due to its ability to inhibit apoptosis and induce proliferation of hepatocytes by targeted inhibition of FOSL2 through the JAK/STAT signaling pathway.

Interleukin-17A-promoted MSC2 polarization related with new bone formation of ankylosing spondylitis

It’s still unknown how over-hyperplasia of tissue such like new bone formation (NBF) developed in ankylosing spondylitis (AS). We found low level of IL-17A promoted TLR4+MSC1 polarization with suppressed osteogenic differentiation through JAK2/STAT3 pathway, while high level of IL-17A promoted TLR3+MSC2 polarization with enhanced osteogenic differentiation through WNT10b/RUNX2 pathway. Furthermore, both proteoglycan-induced spondylitis (PGISp) mouse model and AS patients without NBF showed MSC1 polarization, up-regulated JAK2/STAT3 pathway and high level of IL-17A (peripherally, but not locally), but those with NBF showed MSC2 polarization, up-regulated WNT10b/RUNX2 pathway and high expression of IL-17A at local site. Results showed NBF of AS was induced by MSC2 polarization that was promoted by high level of IL-17A, and may be treated by suppressing local MSC2 polarization.

SOCS-1 is involved in TNF-α-induced mitochondrial dysfunction and apoptosis in renal tubular epithelial cells

Tumor necrosis factor-α (TNF-α) is suggested to induce mitochondrial dysfunction and apoptosis of renal tubular epithelial cells that possibly exacerbates renal function in chronic kidney disease (CKD). Here we investigated whether suppressor of cytokine signaling-1 (SOCS-1), an inhibitor of cytokine signaling, was involved in TNF-α-induced human renal tubular epithelial cells (HKCs) oxidative stress and apoptosis. TNF-α promoted the protein and mRNA expression of SOCS-1 in a time and dose dependent manner, along with increased cell apoptosis and activation of apoptosis signal regulating kinase-1(ASK1) in HKCs. Furthermore, overexpression of SOCS-1 in HKCs reduced TNF-α-mediated oxidative stress and apoptosis. Meanwhile, We also found that overexpression of SOCS-1 could regulate the activity of JAK/STAT signaling pathway. In addition, a specific JAK2 inhibitor, AG490, that both attenuated TNF-α-induced oxidative stress, also reduced apoptosis. Taken together, overexpression of SOCS-1 prevented TNF-α-mediated cell oxidative stress and apoptosis may be via suppression of JAK/STAT signaling pathway activation in HKCs.

Formal Modeling of mTOR Associated Biological Regulatory Network Reveals Novel Therapeutic Strategy for the Treatment of Cancer

Cellular homeostasis is a continuous phenomenon that if compromised can lead to several disorders including cancer. There is a need to understand the dynamics of cellular proliferation to get deeper insights into the prevalence of cancer. Mechanistic Target of Rapamycin (mTOR) is implicated as the central regulator of the metabolic pathway involved in growth whereas its two distinct complexes mTORC1 and mTORC2 perform particular functions in cellular propagation. To date, mTORC1 is a well defined therapeutic target to inhibit uncontrolled cell division, while the role of mTORC2 is not well characterized. Therefore, the current study is designed to understand the signaling dynamics of mTOR and its partner proteins such as PI3K, PTEN, mTORC2, PKB (Akt), mTORC1, and FOXO. For this purpose, a qualitative model of mTOR-associated Biological Regulatory Network (BRN) is constructed to predict its regulatory behaviors which may not be predictable otherwise. The depleted expression of PTEN and FOXO along with the overexpression of PI3K, mTORC2, mTORC1 and Akt is predicted as a stable steady state which is in accordance with their observed expression levels in the progression of various cancers. The qualitative model also predicts the homeostasis of all the entities in the form of qualitative cycles. The significant qualitative (discrete) cycle is identified by analyzing betweenness centralities of the qualitative (discrete) states. This cycle is further refined as a linear hybrid automaton model with the production (activation) and degradation (inhibition) time delays in order to analyze the real-time constraints for its existence. The analysis of the hybrid model provides a formal proof that during homeostasis the inhibition time delay of Akt is less than the inhibition time delay of mTORC2. In conclusion, our observations characterize that in homeostasis Akt is degraded with a faster rate than mTORC2 which suggests that the inhibition of Akt along with the activation of mTORC2 may be a better therapeutic strategy for the treatment of cancer.

Immunoparalysis: Clinical and immunological associations in SIRS and severe sepsis patients

INTRODUCTION

This study was designed to identify changes in the monocytic membrane marker HLA-DR and heat shock proteins (HSPs) in relation to T-regulatory cells (T-regs) and other immunological marker changes in patients with systemic inflammatory response syndrome (SIRS) or sepsis/septic shock.

METHODS

Healthy volunteers, intensive care unit (ICU) patients with SIRS due to head injury and ICU patients with severe sepsis/septic shock were enrolled in the current study. Determination of CD14+/HLA-DR+ cells, intracellular heat-shock proteins and other immunological parameters were performed by flow cytometry and RT-PCR techniques as appropriate. Univariate and multivariate analysis examined associations of CD14/HLA-DR, HSPs, T-regs and suppressor of cytokine signalling (SOCS) proteins with SIRS, sepsis and outcome.

RESULTS

Fifty patients (37 with severe sepsis and 13 with SIRS) were enrolled, together with 20 healthy volunteers used as a control group. Compared to healthy individuals, patients with SIRS and severe sepsis showed progressive decline of their CD14/HLA-DR expression (0% to 7.7% to 50% within each study subpopulation, p<0.001). Mean fluorescent intensity (MFI) levels of HSP70 and HSP90 on monocytes and polymorphonuclear cells were significantly higher in SIRS patients compared to controls and fell significantly in severe sepsis/septic shock patients (p<0.05 for all comparisons). There was no statistically significant difference between subgroups for levels of T-regulatory cells or relative copies of Suppressor of Cytokine Signalling 3 (SOCS3) proteins. In univariate models percent of CD14/HLA-DR was associated with mortality (OR: 1.8 95%CI 1.02-3.2, p=0.05), while in multivariate models after adjusting for CD14/HLA-DR only younger age and lower Acute Physiology and Chronic Health Evaluation II (APACHE II) scores were associated with increased chances of survival (beta -0.05, OR 0.9, 95% CI 0.9-0.99, p=0.038 for age and beta -0.11, OR 0.89, 95% CI 0.8-0.99, p=0.037 for APACHE II score).

CONCLUSIONS

Significant associations with SIRS and sepsis were found for CD14/HLA-DR expression and monocyte and polymorphonuclear cell levels of HSP70 and 90. The role of these biomarkers in assessing the prognosis of sepsis needs to be further explored and validated in prospective studies.

High mobility group box 1 induces the activation of the Janus kinase 2 and signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway in pancreatic acinar cells in rats, while AG490 and rapamycin inhibit their activation

The pathogenesis of severe acute pancreatitis (SAP) remains unclear. The Janus kinase and signal transducer and activator of transcription (JAK/STAT) pathway is important for various cytokines and growth factors. This study investigated the effect of the late inflammatory factor high mobility group box 1 (HMGB1) on the activation of JAK2/STAT3 in pancreatic acinar cells and the inhibitory effects of AG490 (a JAK2 inhibitor) and rapamycin (a STAT3 inhibitor) on this pathway. Rat pancreatic acinar cells were randomly divided into the control, HMGB1, AG490, and rapamycin groups. The mRNA levels of JAK2 and STAT3 at 10, 30, 60, and 120 minutes were detected using reverse transcription polymerase chain reaction (RT-PCR). The protein levels of JAK2 and STAT3 at 60 and 120 minutes were observed using Western blotting. Compared with the control group, the HMGB1 group exhibited significantly increased levels of JAK2 mRNA at each time point; STAT3 mRNA at 30, 60, and 120 minutes; and JAK2 and STAT3 proteins at 60 and 120 minutes (p < 0.01). Compared with the HMGB1 group, the AG490 and rapamycin groups both exhibited significantly decreased levels of JAK2 mRNA at each time point (p < 0.05); STAT3 mRNA at 30, 60, and 120 minutes (p < 0.01); and JAK2 and STAT3 proteins at 60 and 120 minutes (p < 0.01). HMGB1 induces the activation of the JAK2/STAT3 signaling pathway in rat pancreatic acinar cells, and this activation can be inhibited by AG490 and rapamycin. The results of this study may provide new insights for the treatment of SAP.

Gram Negative Bacterial Inflammation Ameliorated by the Plasma Protein Beta 2-Glycoprotein I

Lipopolysaccharide (LPS) is a major component of the outer wall of gram negative bacteria. In high doses LPS contributes to the inflammation in gram negative sepsis, and in low doses contributes to the low grade inflammation characteristic of the metabolic syndrome. We wanted to assess the role of beta2-glycoprotein I (β2GPI) a highly conserved plasma protein and its different biochemical forms in a mouse model of LPS systemic inflammation. Normal and β2GPI deficient mice were administered LPS through their veins and assessed for a range of inflammation markers in their blood and liver. Different biochemical forms of β2GPI were measured in normal mice given either saline or LPS. We show that β2GPI has a significant role in inhibiting LPS induced inflammation. In this study we provide some evidence that β2GPI serves a protective role in a mouse model of LPS inflammation. This resolves the controversy of previous studies which used LPS and β2GPI in test tube based models of LPS induced activation of white cells. We also highlight the potential relevance of a newly discovered biochemical form of β2GPI in LPS mediated inflammation and we speculate that this form has a protective role against LPS induced pathology.

Modeling and analysis of innate immune responses induced by the host cells against hepatitis C virus infection

An in-depth understanding of complex systems such as hepatitis C virus (HCV) infection and host immunomodulatory response is an open challenge for biologists. In order to understand the mechanisms involved in immune evasion by HCV, we present a simplified formalization of the highly dynamic system consisting of HCV, its replication cycle and host immune responses at the cellular level using hybrid Petri net (HPN). The approach followed in this study comprises of step wise simulation, model validation and analysis of host immune response. This study was performed with an objective of making correlations among viral RNA levels, interferon (IFN) production and interferon stimulated genes (ISGs) induction. The results correlate with the biological data verifying that the model is very useful in predicting the dynamic behavior of the signaling proteins in response to a stimulus. This study implicates that HCV infection is dependent upon several key factors of the host immune response. The effect of host proteins on limiting viral infection is effectively overruled by the viral pathogen. This study also analyzes activity levels of RNase L, miR-122, IFN, ISGs and PKR induction and inhibition of TLR3/RIG1 mediated pathways in response to targeted manipulation in the presence of HCV. The results are in complete agreement at the time of writing with the published expression studies and western blot experiments. Our model also provides some biological insights regarding the role of PKR in the acute infection of HCV. It might help to explain why many patients fail to clear acute HCV infection while others, with low ISG basal levels, clear HCV spontaneously. The described methodology can easily be reproduced, which suitably supports the study of other viral infections in a formal, automated and expressive manner. The Petri net-based modeling approach applied here may provide valuable insights for study design and analyses to evaluate other disease associated integrated pathways in biological systems.