Epigenetic regulation of nitric oxide synthase 2, inducible (Nos2) by NLRC4 inflammasomes involves PARP1 cleavage

Sex-specific mechanisms of cerebral microvascular BKCa dysfunction in a mouse model of Alzheimer's disease

INTRODUCTION

Cerebrovascular dysfunction occurs in Alzheimer's disease (AD), impairing hemodynamic regulation. Large conductance Ca2+-activated K+ channels (BKCa) regulate cerebrovascular reactivity and are impaired in AD. BKCa activity depends on intracellular Ca2+ (Ca2+ sparks) and nitro-oxidative post-translational modifications. However, whether these mechanisms underlie BKCa impairment in AD remains unknown.

METHODS

Cerebral arteries from 5x-FAD and wild-type (WT) littermates were used for molecular biology, electrophysiology, ex vivo, and in vivo experiments.

RESULTS

Arterial BKCa activity is reduced in 5x-FAD via sex-dependent mechanisms: in males, there is lower BKα subunit expression and less Ca2+ sparks. In females, we observed reversible nitro-oxidative modification of BKCa. Further, BKCa is involved in hemodynamic regulation in WT mice, and its dysfunction is associated with vascular deficits in 5x-FAD.

DISCUSSION

Our data highlight the central role played by BKCa in cerebral hemodynamic regulation and that molecular mechanisms of its impairment diverge based on sex in 5x-FAD.

HIGHLIGHTS

Cerebral microvascular BKCa dysfunction occurs in both female and male 5x-FAD. Reduction in BKα subunit protein and Ca2+ sparks drive the dysfunction in males. Nitro-oxidative stress is present in females, but not males, 5x-FAD. Reversible nitro-oxidation of BKα underlies BKCa dysfunction in female 5x-FAD.

NAIP/NLRC4 inflammasome participates in macrophage responses to Trypanosoma cruzi by a mechanism that relies on cathepsin-dependent caspase-1 cleavage

Inflammasomes are large protein complexes that, once activated, initiate inflammatory responses by activating the caspase-1 protease. They play pivotal roles in host defense against pathogens. The well-established role of NAIP/NLRC4 inflammasome in bacterial infections involves NAIP proteins functioning as sensors for their ligands. However, recent reports have indicated the involvement of NLRC4 in non-bacterial infections and sterile inflammation, even though the role of NAIP proteins and the exact molecular mechanisms underlying inflammasome activation in these contexts remain to be elucidated. In this study, we investigated the activation of the NAIP/NLRC4 inflammasome in response to Trypanosoma cruzi, the protozoan parasite responsible for causing Chagas disease. This parasite has been previously demonstrated to activate NLRP3 inflammasomes. Here we found that NAIP and NLRC4 proteins are also required for IL-1β and Nitric Oxide (NO) release in response to T. cruzi infection, with their absence rendering macrophages permissive to parasite replication. Moreover, Nlrc4 -/- and Nlrp3 -/- macrophages presented similar impaired responses to T. cruzi, underscoring the non-redundant roles played by these inflammasomes during infection. Notably, it was the live trypomastigotes rather than soluble antigens or extracellular vesicles (EVs) secreted by them, that activated inflammasomes in a cathepsins-dependent manner. The inhibition of cathepsins effectively abrogated caspase-1 cleavage, IL-1β and NO release, mirroring the phenotype observed in Nlrc4 -/-/Nlrp3 -/- double knockout macrophages. Collectively, our findings shed light on the pivotal role of the NAIP/NLRC4 inflammasome in macrophage responses to T. cruzi infection, providing new insights into its broader functions that extend beyond bacterial infections.

Inflammasome activation and pyroptosis mediate coagulopathy and inflammation in Salmonella systemic infection

Inflammasome activation is a critical defense mechanism against bacterial infection. Previous studies suggest that inflammasome activation protects against Salmonella oral infection. Here we find inflammasome activation plays a critical role in the pathogenesis of Salmonella systemic infection. We show that in a systemic infection model by i.p. injection of Salmonella, deficiency of caspase-1 or gasdermin-D prolonged survival time, reduced plasma concentrations of the proinflammatory cytokines IL-1β, IL-6 and TNFα. These deficiencies also protected against coagulopathy during Salmonella infection as evidenced by diminished prolongation of prothrombin time and increase in plasma thrombin-antithrombin complex concentrations in the caspase-1 or gasdermin-D deficient mice. Activation of the NAIP/NLRC4 inflammasome by flagellin and/or the components of the SPI1 type 3 secretion system played a critical role in Salmonella-induced coagulopathy. In the absence of flagellin and SPI1, the Salmonella mutant strain still triggered coagulopathy through the caspase-11/NLRP3 pathway. Our results reveal a previously undisclosed role of the inflammasomes and pyroptosis in the pathogenesis of Salmonella systemic infection.

Exploring the potential targets of Biling Weitong Granules on visceral hypersensitivity through integration of network pharmacology and in vivo analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Biling Weitong Granules(BLWTG) are a newly developed traditional Chinese medicine prescription based on the ancient prescription Jinlingzi San and Zuojin Wan. It is used for the treatment of functional gastrointestinal disorders (FGIDs) featured as visceral hypersensitivity(VH). However, its active ingredients and protein targets involved still remain unknown.

AIM OF THE STUDY

To explore the potential targets of BLWTG for the treatment of visceral hypersensitivity.

MATERIALS AND METHODS

Active components and their protein targets of BLWTG were screened from TCMSP database and the component-target network were constructed with Cytoscape software. Irritable bowel syndrome (IBS) was the representative disease in this study and information on its linked pathways was obtained from NCBI, Drugbank and Genecard. Target pathways of BLWTG were analyzed through KEGG to verify the correlation with IBS related pathways.Then, the VH mouse models was induced by maternal separation(MS), randomly divided into normal saline(NS),BLWTG1(low-dosage) and BLWTG2(high-dosage) group. After intervention, threshold intensity of colorectal distension (CRD) and body weight were measured to evaluate relief of IBS symptoms. Elisa was performed to evaluate 5-HT concentration changes of colon tissues. Flow cytometry was performed to assess changes of colon eosinophils and mast cells proportion. Transcriptome sequencing was employed to analyze changes of pathways and differential genes.

RESULTS

199 protein targets and 132 active components of BLWTG were identified. KEGG analysis revealed the overlap between BLWTG target pathways and IBS related pathways such as neuroactive ligand-receptor interaction, tryptophan metabolism and inflammatory reaction. 34 genes were not only BLWTG target proteins but also recognized targets for treating IBS. After maternal separation(MS), the mice showed a significant decrease in threshold intensity of CRD, a progressive decrease in body weight and an increase of 5-HT concentration of colon tissue. The proportion of mast cells and eosinophils in the colon increased. Differential genes including Hp,Ido1 and Aqp7 were significantly increased in MS mice group and IBS-related pathways were upregulated. After treatment of BLWTG, threshold intensity of CRD and body weight were significantly improved and IBS related pathways were downregulated. In addition, among BLWTG protein targets, Il1b,Tnf,Adrb1 and Nos2 were found upregulated in MS + NS mice and downregulated after BLWTG intervention through combination of transcriptome sequencing.

CONCLUSIONS

In maternal separation-induced mouse models, BLWTG could alleviate visceral hypersensitivity, possibly through downregulation of 5-HT concentration and eosinophils and mast cells proportion in colon and critical pathways such as neuroactive ligand-receptor pathway. Potential targets of BLWTG including Il1b,Tnf,Adrb1 and Nos2 were found through integration of network pharmacology database and transcriptome sequencing, providing evidence for further study on mechanisms underlying visceral hypersensitivity.

Impact of diet and host genetics on the murine intestinal mycobiome

The mammalian gut is home to a diverse microbial ecosystem, whose composition affects various physiological traits of the host. Next-generation sequencing-based metagenomic approaches demonstrated how the interplay of host genetics, bacteria, and environmental factors shape complex traits and clinical outcomes. However, the role of fungi in these complex interactions remains understudied. Here, using 228 males and 363 females from an advanced-intercross mouse line, we provide evidence that fungi are regulated by host genetics. In addition, we map quantitative trait loci associated with various fungal species to single genes in mice using whole genome sequencing and genotyping. Moreover, we show that diet and its' interaction with host genetics alter the composition of fungi in outbred mice, and identify fungal indicator species associated with different dietary regimes. Collectively, in this work, we uncover an association of the intestinal fungal community with host genetics and a regulatory role of diet in this ecological niche.

A systematic review of underlying genetic factors associated with ureteropelvic junction obstruction in stenotic human tissue

OBJECTIVE

Genetic factors are implicated in the development of ureteropelvic junction obstruction (UPJO). The aims of this study were: 1) condense and examine the existing data in studies containing information regarding differential gene expression in tissues from patients with UPJO and 2) investigate associations between genetic markers and their related pathways.

MATERIALS AND METHODS

A systematic review of studies published between January 2000 and September 2021 was conducted using the following databases: Ovid/Medline, PubMed, Wiley Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. Of 249 studies, 10 were included in the final analysis. The search was performed using the terms "ureteropelvic junction obstruction", "genetic", "gene", and "gene expression". Literature pertaining to differential gene expression in UPJO patients as compared to healthy controls was identified. Studies containing gene expression and quantification of molecular data carried out directly on stenotic tissue samples were selected for analysis. Gene network connections and functional analyses were then determined using MetaScape software.

RESULTS

From the ten studies identified for analysis, fifteen genes were noted as differentially expressed. In UPJO patients, nine genes were upregulated (ET1, ACTA2, MCP-1, TGFB1, NFKB1, IL-6, HIF1A, S100A1, SYP) and six were downregulated (ADM, NOS2, EGF, PDGFRA, UCHL1, NGFR). These genes were principally involved in HIF-1 signaling pathway, blood vessel development, positive regulation of signaling receptor activity, and Ras signaling pathway.

CONCLUSIONS

A potential link exists between genes related to hypoxia, excessive fibrous tissue formation, and inflammation in the development of UPJO, and these connections merit more detailed, tissue level investigations in UPJO patients. The outcomes of this systematic review may lay the groundwork for the development of future targeted therapies and novel biomarker detection for treatments, early detection, and possible prediction and prevention of development of UPJO.

A specific, non-immune system-related isoform of the human inducible nitric oxide synthase is expressed during differentiation of human stem cells into various cell types

BACKGROUND

NOS2 expression is mostly found in bacteria-exposed or cytokine-treated tissues and is mostly connected to innate immune reactions. There are three isoforms of NOS2 (NOS2-1 to -3). In RNA-seq data sets, analyzing inflammatory gene expression, only expression of the NOS2-1 mRNA isoform is detected. However, the expression of NOS2 in differentiating human pluripotent stems (hPSCs) has not been analyzed yet.

METHODS

Public available RNA-seq databases were screened for data of hPSCs during differentiation to different target cells. An isoform specific algorithm was used to analyze NOS2 mRNA isoform expression. In addition, we differentiated four different human iPSC cell lines toward cortical neurons and analyzed NOS2 mRNA expression by qRT-PCR and 5'-RACE. The functionality of the NOS2-2 protein was analyzed by transient transfection of expression clones in human DLD1 cells and nitrate measurement in the supernatant of these cells.

RESULTS

In RNA-seq databases we detected a transient expression of the NOS2 mRNA during the differentiation of hPSCs to cardiomyocytes, chondrocytes, mesenchymal stromal cells, neurons, syncytiotrophoblast cells, and trophoblasts. NOS2 mRNA isoform specific analyses showed, that the transiently expressed NOS2 mRNA in differentiating hPSC (NOS2-2; "diff-iNOS") differ remarkably from the already described NOS2 transcript found in colon or induced islets (NOS2-1; "immuno-iNOS"). Also, analysis of the NOS2 mRNA- and protein expression during the differentiation of four different hiPSC lines towards cortical neurons showed a transient expression of the NOS2 mRNA and NOS2 protein on day 18 of the differentiation course. 5'-RACE experiments and isoform specific qRT-PCR analyses revealed that only the NOS2-2 mRNA isoform was expressed in these experiments. To analyze the functionality of the NOS2-2 protein, we transfected human DLD-1 cells with tetracycline inducible expression clones encoding the NOS2-1- or -2 coding sequence. After induction of the NOS2-1 or -2 mRNA expression by tetracycline a similar nitrate production was measured proofing the functionality of the NOS2-2 protein isoform.

CONCLUSIONS

Our data show that a differentiation specific NOS2 isoform (NOS2-2) is transiently expressed during differentiation of hPSC. Video Abstract.

Host-virus interaction and viral evasion

With each infectious pandemic or outbreak, the medical community feels the need to revisit basic concepts of immunology to understand and overcome the difficult times brought about by these infections. Regarding viruses, they have historically been responsible for many deaths, and such a peculiarity occurs because they are known to be obligate intracellular parasites that depend upon the host's cell machinery for their replication. Successful infection with the production of essential viral components requires constant viral evolution as a strategy to manipulate the cellular environment, including host internal factors, the host's nonspecific and adaptive immune responses to viruses, the metabolic and energetic state of the infected cell, and changes in the intracellular redox environment during the viral infection cycle. Based on this knowledge, it is fundamental to develop new therapeutic strategies for controlling viral dissemination, by means of antiviral therapies, vaccines, or antioxidants, or by targeting the inhibition or activation of cell signaling pathways or metabolic pathways that are altered during infection. The rapid recovery of altered cellular homeostasis during viral infection is still a major challenge. Here, we review the strategies by which viruses evade the host's immune response and potential tools used to develop more specific antiviral therapies to cure, control, or prevent viral diseases.

Macrophage inflammatory state in Type 1 diabetes: triggered by NLRP3/iNOS pathway and attenuated by docosahexaenoic acid

Type 1 diabetes mellitus (T1D) is a chronic autoimmune disease characterized by insulin-producing pancreatic β-cell destruction and hyperglycemia. While monocytes and NOD-like receptor family-pyrin domain containing 3 (NLRP3) are associated with T1D onset and development, the specific receptors and factors involved in NLRP3 inflammasome activation remain unknown. Herein, we evaluated the inflammatory state of resident peritoneal macrophages (PMs) from genetically modified non-obese diabetic (NOD), NLRP3-KO, wild-type (WT) mice and in peripheral blood mononuclear cells (PBMCs) from human T1D patients. We also assessed the effect of docosahexaenoic acid (DHA) on the inflammatory status. Macrophages from STZ-induced T1D mice exhibited increased inflammatory cytokine/chemokine levels, nitric oxide (NO) secretion, NLRP3 and iNOS protein levels, and augmented glycolytic activity compared to control animals. In PMs from NOD and STZ-induced T1D mice, DHA reduced NO production and attenuated the inflammatory state. Furthermore, iNOS and IL-1β protein expression levels and NO production were lower in the PMs from diabetic NLRP3-KO mice than from WT mice. We also observed increased IL-1β secretion in PBMCs from T1D patients and immortalized murine macrophages treated with advanced glycation end products and palmitic acid. The present study demonstrated that the resident PMs are in a proinflammatory state characterized by increased NLRP3/iNOS pathway-mediated NO production, up-regulated proinflammatory cytokine/chemokine receptor expression and altered glycolytic activity. Notably, ex vivo treatment with DHA reverted the diabetes-induced changes and attenuated the macrophage inflammatory state. It is plausible that DHA supplementation could be employed as adjuvant therapy for treating individuals with T1D.

Extracellular vesicles derived from head and neck squamous cells carcinoma inhibit NLRP3 inflammasomes

The content of tumor-derived extracellular vesicles (EVs) can regulate the tumor microenvironment and functionally acts in favor of cancer aggressiveness. To better elucidate the role of EVs in the interplay between immune system and tumor microenvironment, the purpose of this study was to analyze the effect of head and neck squamous cells carcinoma (HNSCC)-derived EVs on the modulation of inflammasomes - mediators of pyroptosis and secretion of inflammatory factors by macrophages. Our results showed that macrophages treated with the Vesicular Secretome Fraction (VSF) isolated from patient-derived HNSCC presented a reduction in the secretion of mature IL-1β and caspase-1 without affecting cell viability. An analysis of the protein content of HNSCC-derived VSF by antibody array revealed that some of the most expressed proteins share a correlation with Transforming Growth Factor-beta (TGF-β) activity. Since TGF-β is related to the inhibition of the NF-kB-related pathways, including those required for the priming phase of the inflammasomes, we sought to evalute the interference of the VSF in the induction of inflammasome components. In fact, HNSCC-derived VSF inhibited the induction of pro-IL-1β and pro-caspase-1 proteins and NLRP3 gene expression during the priming phase of inflammasome activation. Thus, our findings contribute to a better understanding of how tumor-derived EVs modulate inflammatory response by demonstrating their role in inhibiting NLRP3 inflammasomes.

•

Vesicular Secretome Fraction (VSF) from HNSCC inhibits macrophage responses to the NLRP3 inflammasomes agonists.

•

HNSCC-derived VSF is enriched with proteins correlated with the Transforming Growth Factor-b pathway.

•

HNSCC-derived VSF affects the priming phase of inflammasome activation.

The Role of PARP1 in Monocyte and Macrophage Commitment and Specification: Future Perspectives and Limitations for the Treatment of Monocyte and Macrophage Relevant Diseases with PARP Inhibitors

Modulation of PARP1 expression, changes in its enzymatic activity, post-translational modifications, and inflammasome-dependent cleavage play an important role in the development of monocytes and numerous subtypes of highly specialized macrophages. Transcription of PARP1 is governed by the proliferation status of cells at each step of their development. Higher abundance of PARP1 in embryonic stem cells and in hematopoietic precursors supports their self-renewal and pluri-/multipotency, whereas a low level of the enzyme in monocytes determines the pattern of surface receptors and signal transducers that are functionally linked to the NFκB pathway. In macrophages, the involvement of PARP1 in regulation of transcription, signaling, inflammasome activity, metabolism, and redox balance supports macrophage polarization towards the pro-inflammatory phenotype (M1), which drives host defense against pathogens. On the other hand, it seems to limit the development of a variety of subsets of anti-inflammatory myeloid effectors (M2), which help to remove tissue debris and achieve healing. PARP inhibitors, which prevent protein ADP-ribosylation, and PARP1‒DNA traps, which capture the enzyme on chromatin, may allow us to modulate immune responses and the development of particular cell types. They can be also effective in the treatment of monocytic leukemia and other cancers by reverting the anti- to the proinflammatory phenotype in tumor-associated macrophages.

NLRC4 biology in immunity and inflammation

Inflammasomes are cytosolic multiprotein complexes that sense microbial infections or host cell damage, triggering cytokine production and a proinflammatory form of cell death, called pyroptosis. Whereas pyroptosis and cytokine production may often promote host resistance to infections, uncontrolled inflammasome activation leads to autoinflammatory diseases in humans. Among the multiple inflammasomes described, the neuronal apoptosis inhibitory protein/nucleotide-binding domain leucine-rich repeat-containing protein family caspase activation and recruitment domain-containing protein 4 (NLRC4) inflammasome emerged as a critical component for the restriction of bacterial infections. Accordingly, our understanding of this inflammasome advanced remarkably over the last 10 yr, expanding our knowledge about ligand-receptor interaction; cryo-EM structure; and downstream effectors and substrates, such as gasdermin-D, caspase-1, caspase-8, and caspase-7. In this review, we discuss recent advances on the biology of the NLRC4 inflammasome, in terms of structure and activation mechanisms, importance in bacterial and nonbacterial diseases, and the identification of NLRC4 gain-of-function mutations leading to NLRC4-associated autoinflammatory diseases in humans.

microRNA-216a protects against human retinal microvascular endothelial cell injury in diabetic retinopathy by suppressing the NOS2/JAK/STAT axis

OBJECTIVE

Since microRNAs (miRNAs) represent as effective therapeutic targets for diabetic retinopathy (DR), we identified aberrantly expressed miRNAs related to cellular dysfunction in DR and further detected their potential targets. This study aimed to explore the synergistic effect of miR-216a, inducible nitric oxide synthase 2 (NOS2) and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway on human retinal microvascular endothelial cell (HRMEC) injury in DR.

METHODS

The differentially expressed genes in DR were obtained by GEO database, and the downstream signaling pathways and upstream targeted miRNAs were obtained through bioinformatics analysis. Subsequently, a DR model rat was established, and the target miR-216a was overexpressed to observe the pathological and morphological changes of the rat retina and the levels of inflammatory factors. Then, HRMECs were extracted and added with d-Glucose, and then transfected with miR-216a, NOS2 or adding JAK/STAT signaling pathway specific inhibitor to observe changes in cell activity and inflammatory damage.

RESULTS

NOS2 was significantly upregulated, and the JAK/STAT signaling pathway was significantly activated in DR. miR-216a targeted NOS2, which played a protective role in the retina of DR rats. Moreover, in cell experiments, overexpression of miR-216a promoted the viability of HRMECs under d-glucose treatment, and inhibited NOS2 expression and the JAK/STAT signaling pathway activation.

CONCLUSION

This study suggests that miR-216a protects against HRMECs injury in DR by suppressing the NOS2/JAK/STAT axis.

CD163+ tumor-associated macrophage accumulation in breast cancer patients reflects both local differentiation signals and systemic skewing of monocytes

Objectives

The accumulation of tumor‐associated macrophages (TAMs) is correlated with poor clinical outcome, but the mechanisms governing their differentiation from circulating monocytes remain unclear in humans.

Methods

Using multicolor flow cytometry, we evaluated TAMs phenotype in 93 breast cancer (BC) patients. Furthermore, monocytes from healthy donors were cultured in the presence of supernatants from dilacerated primary tumors to investigate their differentiation into macrophages (MΦ) in vitro. Additionally, we used transcriptomic analysis to evaluate BC patients’ blood monocytes profiles.

Results

We observed that high intra‐tumor CD163‐expressing TAM density is predictive of reduced survival in BC patients. In vitro, M‐CSF, TGF‐β and VEGF from primary tumor supernatants skewed the differentiation of healthy donor blood monocytes towards CD163^highCD86^lowIL‐10^high M2‐like MΦ that strongly suppressed CD4⁺ T‐cell expansion via PD‐L1 and IL‐10. In addition, blood monocytes from about 40% of BC patients displayed an altered response to in vitro stimulation, being refractory to type‐1 MΦ (M1‐MΦ) differentiation and secreting higher amounts of immunosuppressive, metastatic‐related and angiogenic cytokines. Aside from showing that monocyte transcriptome is significantly altered by the presence of BC, we also demonstrated an overall metabolic de‐activation in refractory monocytes of BC patients. In contrast, monocytes from sensitive BC patients undergoing normal M1‐MΦ differentiation showed up‐regulation of IFN‐response genes and had no signs of metabolic alteration.

Conclusion

Altogether, our results suggest that systemic factors skew BC patient blood monocytes towards a pro‐metastatic profile, resulting in the accumulation of further polarised CD163^high TAMs resembling type‐2 MΦ (M2‐MΦ) in the local BC microenvironment. These data indicate that monitoring circulating monocytes in BC patients may provide an indication of early systemic alterations induced by cancer and, thus, be instrumental in the development of improved personalised immunotherapeutic interventions.

Transcriptomic Profiles of Monocyte-Derived Macrophages in Response to Escherichia coli is Associated with the Host Genetics

Reactive Nitrogen Species (RNS) are a group of bactericidal molecules produced by macrophages in response to pathogens in a process called oxidative burst. Nitric oxide (NO^-) is a member of RNS produced from arginine by inducible Nitric Oxide Synthase (iNOS) enzyme. The activity of iNOS and production of NO^- by macrophages following stimulation is one of the indicators of macrophage polarization towards M1/proinflammatory. Production of NO^- by bovine monocyte-derived macrophage (MDM) and mouse peritoneal macrophages has been shown to be strongly associated with host genetic with the heritability of 0.776 in bovine MDM and 0.8 in mouse peritoneal macrophages. However, the mechanism of genetic regulation of macrophage response has remained less explored. In the current study, the transcriptome of bovine MDMs was compared between two extreme phenotypes that had been classified as high and low responder based on NO^- production. The results showed that 179 and 392 genes were differentially expressed (DE) between high and low responder groups at 3 and 18 hours after exposure to Escherichia coli, respectively. A set of 11 Transcription Factors (TFs) (STAT1, IRF7, SPI1, STAT4, IRF1, HIF1A, FOXO3, REL, NFAT5, HIC1, and IRF4) at 3 hours and a set of 13 TFs (STAT1, IRF1, HIF1A, STAT4, ATF4, TP63, EGR1, CDKN2A, RBL1, E2F1, PRDM1, GATA3, and IRF4) at 18 hours after exposure to E. coli were identified to be differentially regulated between the high and low responder phenotypes. These TFs were found to be divided into two clusters of inflammatory- and hypoxia-related TFs. Functional analysis revealed that some key canonical pathways such as phagocytosis, chemotaxis, antigen presentation, and cell-to-cell signalling are enriched among the over-expressed genes by high responder phenotype. Based on the results of this study, it was inferred that the functional characteristics of bovine MDMs are associated with NO-based classification. Since NO^- production is strongly associated with host genetics, this study for the first time shows the distinct proinflammatory profiles of macrophages are controlled by the natural genetic polymorphism in an outbred population. In addition, the results suggest that genetics can be considered as a new dimension in the current model of macrophage polarization which is currently described by the combination of stimulants, only.

Deciphering the multicomponent synergy mechanisms of SiNiSan prescription on irritable bowel syndrome using a bioinformatics/network topology based strategy

BACKGROUND

SiNiSan (SNS) is a traditional Chinese medicine (TCM) prescription that has been widely used in the clinical treatment of irritable bowel syndrome (IBS). However, the underlying active substances and molecular mechanisms remain obscure.

PURPOSE

A bioinformatics/topology based strategy was proposed for identification of the drug targets, therapeutic agents and molecular mechanisms of SiNiSan against irritable bowel syndrome.

MATERIALS AND METHODS

In this work, a bioinformatics/network topology based strategy was employed by integrating ADME filtering, text mining, bioinformatics, network topology, Venn analysis and molecular docking to uncover systematically the multicomponent synergy mechanisms. In vivo experimental validation was executed in a Visceral Hypersensitivity (VHS) rat model.

RESULTS

76 protein targets and 109 active components of SNS were identified. Bioinformatics analysis revealed that 116 disease pathways associated with IBS therapy could be classified into the 19 statistically enriched functional sub-groups. The multi-functional co-synergism of SNS against IBS were predicted, including inflammatory reaction regulation, oxidative-stress depression regulation and hormone and immune regulation. The multi-component synergetic effects were also revealed on the herbal combination of SNS. The hub-bottleneck genes of the protein networks including PTGS2, CALM2, NOS2, SLC6A3 and MAOB, MAOA, CREB1 could become potential drug targets and Paeoniflorin, Naringin, Glycyrrhizic acid may be candidate agents. Experimental results showed that the potential mechanisms of SiNiSan treatment involved in the suppression of activation of Dopaminergic synapse and Amphetamine addiction signaling pathways, which are congruent with the prediction by the systematic approach.

CONCLUSION

The integrative investigation based on bioinformatics/network topology strategy may elaborate the multicomponent synergy mechanisms of SNS against IBS and provide the way out to develop new combination medicines for IBS.

The impairment in the NLRP3-induced NO secretion renders astrocytes highly permissive to T. cruzi replication

Trypanossoma cruzi (T. cruzi), the causative protozoan of Chagas disease (CD) invades many cell types, including central nervous system (CNS) cells triggering local lesions and neurological impact. Previous work from our group described NLRP3 inflammasomes as central effectors for the parasite control by macrophages. Recent evidences demonstrate that NLRP3 can be activated in CNS cells with controversial consequences to the control of infections and inflammatory pathologies. However, the relative contribution of NLRP3 in different cell types remains to be elucidated. In this article, we described an effector response mediated by NLRP3 that works on microglia but not on astrocytes to control T. cruzi infection. Despite T. cruzi ability to invade astrocytes and microglia, astrocytes were clearly more permissive to parasite replication. Moreover, the absence of NLRP3 renders microglia but not astrocytes more permissive to T. cruzi replication. In fact, microglia but not astrocytes were able to secrete NLRP3-dependent IL-1β and NO in response to T. cruzi. Importantly, the pharmacological inhibition of iNOS with aminoguanidine resulted in a significant increase in the numbers of amastigotes found in microglia from wild-type but not from NLRP3^-/- mice, indicating the importance of NLRP3-mediated NO secretion to the infection control by these cells. Taken together, our findings revealed that T. cruzi differentially activates NLRP3 inflammasomes in astrocytes and microglia and established a role for these platforms in the control of a protozoan infection by glial cells from CNS.

Exploring the multicomponent synergy mechanism of Banxia Xiexin Decoction on irritable bowel syndrome by a systems pharmacology strategy

ETHNOPHARMACOLOGICAL RELEVANCE

Banxia Xiexin Decoction (BXD) is a representative prescription to regulate spleen and stomach in "Treatise on Febrile Diseases", which has been proven effective for the clinical treatment of irritable bowel syndrome (IBS) in the past decades. However, the active principles and molecular mechanisms involved in BXD against IBS are vague yet.

AIM OF THE STUDY

To unfold multicomponent synergy mechanism of BXD on irritable bowel syndrome, this work explored active principles, drug targets and crucial pathways using a systems pharmacology strategy.

MATERIALS AND METHODS

In this study, a systems pharmacology based strategy was applied by the procedures integrating compound database construction, ADME evaluation, target identification, functional annotation, pathway enrichment analysis, network analysis, and molecular docking verification. The 158 compounds from BXD were selected for the screening. The Compound-Target network (C-T) and the Target-Pathway network (T-P) were constructed. The bioinformatics and network topology were employed to systematically reveal multicomponent-target interactions of BXD. The affinity between important ingredients and the kernel targets was validated using molecular mechanics simulation.

RESULTS

The 35 potential important ingredients and the 16 associated kernel targets were identified. 27 crucial pathways, in which the kernel targets participated, could regulate the biological processes, such as synthesis of inflammatory mediators, smooth muscle relaxation and synaptic plasticity, closely related to pathological mechanism of IBS. The cross-talk interactions were revealed between TNF signaling pathway, Dopaminergic synapse and cGMP-PKG signaling pathway, which would exert the synergistic influences on the occurrence and treatment of the IBS. PTGS2, CALM, NOS2, SCN5A, and PRSS1 might become novel drug targets for IBS.

CONCLUSIONS

The study demonstrated that the synergy molecular mechanisms of BXD mainly involved three therapeutic modules including inhibiting inflammatory reaction, maintaining intestinal function and improving psychological regulation via the multicomponent-target interaction networks. It may also provide the promising drug targets and therapeutic agents for the development of new medicines.

Local anaesthetics upregulate nitric oxide generation in cord blood and adult human neutrophils

Nitric oxide (NO) generation by systemic neonatal neutrophils is not clarified. It is also not known whether local anaesthetics (LAs) transferred to the fetal systemic circulation following maternal epidural blockade may affect this process. In the present study, NO generation was evaluated in neutrophils from cord blood (CB, n = 11) and adult blood (n = 10) following exposure to bupivacaine (0.0005, 0.005, 1 mM), lidocaine (0.002, 0.02, 4 mM) and ropivacaine (0.0007, 0.007, 1.4 mM) using flow cytometry, as well as indirectly by determining nitrite concentrations in cell incubation media. To determine the role of NO synthase (NOS) isoforms in NO generation following exposure to LAs, experiments were repeated in the presence of the NOS inhibitors, N^G-nitro-L-arginine methyl ester and aminoguanidine; in addition, the expression of NOS isoforms was analysed. CB neutrophils produced less NO than adult neutrophils. LAs, especially ropivacaine and lidocaine, stimulated neutrophil NO generation, but in CB neutrophils this effect was negligible at clinically relevant drug concentrations. A mechanism involving NOS activity was responsible for the observed phenomena. In conclusion, LAs are able to upregulate neutrophil NO production, but in neonates this effect is likely to be clinically insignificant.

Inhibitors targeting CDK4/6, PARP and PI3K in breast cancer: a review

Breast cancer is the global leading cause of cancer-related death in women and it represents a major health burden worldwide. One of the promising breast cancer therapeutic avenues is through small molecule inhibitors (SMIs) which have undergone rapid progress with successful clinical trials. Recently, three emerging and vital groups of proteins are targeted by SMIs for breast cancer treatment, namely cyclin-dependent kinase 4 and 6 (CDK4/6), poly (adenosine diphosphate-ribose) polymerase (PARP) and phosphoinositide 3-kinase (PI3K). Several of these inhibitors have been approved for the treatment of breast cancer patients or progressed into late-stage clinical trials. Thus, modeling from these successful clinical trials, as well as their limitations, is pivotal for future development and trials of other inhibitors or therapeutic regimens targeting breast cancer patients. In this review, we discuss eight recently approved or novel SMIs against CDK4/6 (palbociclib, ribociclib and abemaciclib), PARP (olaparib, veliparib and talazoparib), and PI3K (buparlisib and alpelisib). The mechanisms of action, series of clinical trials and limitations are described for each inhibitor.

Effect of Diabetes Mellitus on the Pharmacokinetics and Pharmacodynamics of Tuberculosis Treatment

Diabetes mellitus (DM) and tuberculosis (TB) are two common diseases with increasing geographic overlap and clinical interactions. The effect of DM and hemoglobin A1c (HbA1c) values on the pharmacokinetics (PK) and pharmacodynamics (PD) of anti-TB drugs remains poorly characterized. Newly diagnosed TB patients with and without DM starting fixed-dose, thrice-weekly treatment underwent sampling for PK assessments (predose and 0.5, 2, and 6 h postdose) during the intensive and continuation phases of treatment. The effect of DM and HbA1c values on the maximum concentration (C _max) of rifampin, isoniazid, and pyrazinamide and the association between drug concentrations and microbiologic and clinical outcomes were assessed. Of 243 patients, 101 had DM. Univariate analysis showed significant reductions in the C _max of pyrazinamide and isoniazid (but not rifampin) with DM or increasing HbA1c values. After adjusting for age, sex, and weight, DM was associated only with reduced pyrazinamide concentrations (adjusted geometric mean ratio = 0.74, P = 0.03). In adjusted Cox models, female gender (adjusted hazards ratio [aHR] = 1.75, P = 0.001), a lower smear grade with the Xpert assay (aHR = 1.40, P < 0.001), and the pyrazinamide C _max (aHR = 0.99, P = 0.006) were independent predictors of sputum culture conversion to negative. Higher isoniazid or rifampin concentrations were associated with a faster time to culture conversion in patients with DM only. A pyrazinamide C _max above the therapeutic target was associated with higher unfavorable outcomes (treatment failure, relapse, death) (odds ratio = 1.92, P = 0.04). DM and higher HbA1c values increased the risk of not achieving therapeutic targets for pyrazinamide (but not rifampin or isoniazid). Higher pyrazinamide concentrations, though, were associated with worse microbiologic and clinical outcomes. DM status also appeared to influence PK-PD relationships for isoniazid and rifampin.

Neuroimmunomodulation in Major Depressive Disorder: Focus on Caspase 1, Inducible Nitric Oxide Synthase, and Interferon-Gamma

Major depressive disorder (MDD) is one of the leading causes of disability worldwide, and its incidence is expected to increase. Despite tremendous efforts to understand its underlying biological mechanisms, MDD pathophysiology remains elusive and pharmacotherapy outcomes are still far from ideal. Low-grade chronic inflammation seems to play a key role in mediating the interface between psychological stress, depressive symptomatology, altered intestinal microbiology, and MDD onset. We review the available pre-clinical and clinical evidence of an involvement of pro-inflammatory pathways in the pathogenesis, treatment, and remission of MDD. We focus on caspase 1, inducible nitric oxide synthase, and interferon gamma, three inflammatory systems dysregulated in MDD. Treatment strategies aiming at targeting such pathways alone or in combination with classical therapies could prove valuable in MDD. Further studies are needed to assess the safety and efficacy of immune modulation in MDD and other psychiatric disorders with neuroinflammatory components.

Deletion of poly(ADP‑ribose) polymerase-1 changes the composition of the microbiome in the gut

Poly(adenosine diphosphate-ribose) polymerase (PARP)-1 is the prototypical PARP enzyme well known for its role in DNA repair and as a pro-inflammatory protein. Since PARP1 is an important co-factor of several other pro-inflammatory proteins, in the present study the possible changes in microbial flora of PARP1 knockout mice were investigated. Samples from the duodenum, cecum and feces from wild type and PARP1 knockout C57BL/6J male mice were collected and 16S ribosomal RNA genes were sequenced. Based on the sequencing results, the microbiome and compared samples throughout the lower part of the gastrointestinal system were reconstructed. The present results demonstrated that the lack of PARP1 enzyme only disturbed the microbial flora of the duodenum, where the biodiversity increased in the knockout animals on the species level but decreased on the order level. The most prominent change was the overwhelming abundance of the family Porphyromonadaceae in the duodenum of PARP1^−/− animals, which disappeared in the cecum and feces where families were spread out more evenly than in the wild type animals. The findings of the present study may improve current understanding of the role of PARP1 in chronic inflammatory diseases.

Neutrophil microparticle production and inflammasome activation by hyperglycemia due to cytoskeletal instability

Microparticles are lipid bilayer-enclosed vesicles produced by cells under oxidative stress. MP production is elevated in patients with diabetes, but the underlying cellular mechanisms are poorly understood. We hypothesized that raising glucose above the physiological level of 5.5 mm would stimulate leukocytes to produce MPs and activate the nucleotide-binding domain, leucine-rich repeat pyrin domain-containing 3 (NLRP3) inflammasome. We found that when incubated in buffer with up to 20 mm glucose, human and murine neutrophils, but not monocytes, generate progressively more MPs with high interleukin (IL)-1β content. Enhanced MP production required generation of reactive chemical species by mitochondria, NADPH oxidase, and type 2 nitric-oxide synthase (NOS-2) and resulted in S-nitrosylation of actin. Depleting cells of capon (C-terminal PDZ ligand of neuronal nitric-oxide synthase protein), apoptosis-associated speck-like protein containing C-terminal caspase recruitment domain (ASC), or pro-IL-1β prevented the hyperglycemia-induced enhancement of reactive species production, MP generation, and IL-1β synthesis. Additional components required for these responses included inositol 1,3,5-triphosphate receptors, PKC, and enhancement of filamentous-actin turnover. Numerous proteins become localized to short filamentous actin in response to S-nitrosylation, including vasodilator-stimulated phosphoprotein, focal adhesion kinase, the membrane phospholipid translocation enzymes flippase and floppase, capon, NLRP3, and ASC. We conclude that an interdependent oxidative stress response to hyperglycemia perturbs neutrophil cytoskeletal stability leading to MP production and IL-1β synthesis.