Association of α-fetoprotein levels with liver stiffness measurement in outpatients with chronic hepatitis B

The association between α-fetoprotein (AFP) levels with the assessment of liver stiffness (LS) in chronic hepatitis B (CHB) patients were explored. A total of 283 outpatients with CHB were enrolled. Patient age, alanine aminotransferase (ALT), aspartate aminotransferase (AST), AFP, platelet (PLT), total bilirubin (TB), direct bilirubin (DB), alkaline phosphatase (ALP), albumin (ALB), globulin, and albumin/globulin (A/G) levels were associated with LS values in the univariate model (P<0.05). Significant associations between AFP and PLT levels with LS values were observed when both variables were included in the multivariate analysis models. Receiver operation characteristic (ROC) analysis indicated that the combination of AFP and PLT levels could enhance the predictive performance of liver fibrosis (area under the curve (AUC) = 0.819, P<0.001) and that PLT levels (PLT < 100 × 10⁹/l) combined with high AFP levels (AFP > 8 ng/ml) significantly increased the prediction of liver fibrosis (OR = 11.216). More importantly, LS values associated with higher AFP levels (AFP > 8 ng/ml), independently of higher ALT or AST values, were significantly higher than those of low AFP level groups. In conclusion, in Chinese outpatients with CHB, AFP outperformed ALT and/or AST levels in terms of their association with LS. AFP and PLT levels were independently associated with LS, and their combined assessment could enhance the diagnostic and predictive performance of liver fibrosis among CHB patients.     

Gefitinib initiates sterile inflammation by promoting IL-1β and HMGB1 release via two distinct mechanisms

Anticancer drug gefitinib causes inflammation-based side effects, such as interstitial pneumonitis. However, its mechanisms remain unknown. Here, we provide evidence that gefitinib elicits pro-inflammatory responses by promoting mature-interleukin-1β (IL-1β) and high-mobility group box 1 (HMGB1) release. Mitochondrial reactive oxygen species (mtROS) driven by gefitinib stimulated the formation of the NLRP3 (NACHT, LRR and PYD-containing protein 3) inflammasome, leading to mature-IL-1β release. Notably, gefitinib also stimulated HMGB1 release, which is, however, not mediated by the NLRP3 inflammasome. On the other hand, gefitinib-driven mtROS promoted the accumulation of γH2AX, a hallmark of DNA damage, leading to the activation of poly (ADP-ribose) polymerase-1 (PARP-1) and subsequent active release of HMGB1. Together our results reveal the potential ability of gefitinib to initiate sterile inflammation via two distinct mechanisms, and identified IL-1β and HMGB1 as key determinants of gefitinib-induced inflammation that may provide insights into gefitinib-induced interstitial pneumonitis.Subject terms: Inflammasome, Inflammatory diseases     

IL-1β in atherosclerotic vascular calcification: From bench to bedside

Atherosclerotic vascular calcification contributes to increased risk of death in patients with cardiovascular diseases. Assessing the type and severity of inflammation is crucial in the treatment of numerous cardiovascular conditions. IL-1β, a potent proinflammatory cytokine, plays diverse roles in the pathogenesis of atherosclerotic vascular calcification. Several large-scale, population cohort trials have shown that the incidence of cardiovascular events is clinically reduced by the administration of anti-IL-1β therapy. Anti-IL-1β therapy might reduce the incidence of cardiovascular events by affecting atherosclerotic vascular calcification, but the mechanism underlying this effect remains unclear. In this review, we summarize current knowledge on the role of IL-1β in atherosclerotic vascular calcification, and describe the latest results reported in clinical trials evaluating anti-IL-1β therapies for the treatment of cardiovascular diseases. This review will aid in improving current understanding of the pathophysiological roles of IL-1β and mechanisms underlying its activity.     

Identification of Novel Temperature-sensitive Lethal Alleles in Essential β-Tubulin and Nonessential α2-Tubulin Genes as Fission Yeast Polarity Mutants

We have screened for temperature-sensitive (ts) fission yeast mutants with altered polarity (alp1–15). Genetic analysis indicates that alp2 is allelic to atb2 (one of two α-tubulin genes) and alp12 to nda3 (the single β-tubulin gene). atb2⁺ is nonessential, and the ts atb2 mutations we have isolated are dominant as expected. We sequenced two alleles of ts atb2 and one allele of ts nda3. In the ts atb2 mutants, the mutated residues (G246D and C356Y) are found at the longitudinal interface between α/β-heterodimers, whereas in ts nda3 the mutated residue (Y422H) is situated in the domain located on the outer surface of the microtubule. The ts nda3 mutant is highly sensitive to altered gene dosage of atb2⁺; overexpression of atb2⁺ lowers the restrictive temperature, and, conversely, deletion rescues ts. Phenotypic analysis shows that contrary to undergoing mitotic arrest with high viability via the spindle assembly checkpoint as expected, ts nda3 mutants execute cytokinesis and septation and lose viability. Therefore, it appears that the ts nda3 mutant becomes temperature lethal because of irreversible progression through the cell cycle in the absence of activating the spindle assembly checkpoint pathway.     

Differential recognition of HIV-stimulated IL-1β and IL-18 secretion through NLR and NAIP signalling in monocyte-derived macrophages

Macrophages are important drivers of pathogenesis and progression to AIDS in HIV infection. The virus in the later phases of the infection is often predominantly macrophage-tropic and this tropism contributes to a chronic inflammatory and immune activation state that is observed in HIV patients. Pattern recognition receptors of the innate immune system are the key molecules that recognise HIV and mount the inflammatory responses in macrophages. The innate immune response against HIV-1 is potent and elicits caspase-1-dependent pro-inflammatory cytokine production of IL-1β and IL-18. Although, NLRP3 has been reported as an inflammasome sensor dictating this response little is known about the pattern recognition receptors that trigger the “priming” signal for inflammasome activation, the NLRs involved or the HIV components that trigger the response. Using a combination of siRNA knockdowns in monocyte derived macrophages (MDMs) of different TLRs and NLRs as well as chemical inhibition, it was demonstrated that HIV Vpu could trigger inflammasome activation via TLR4/NLRP3 leading to IL-1β/IL-18 secretion. The priming signal is triggered via TLR4, whereas the activation signal is triggered by direct effects on Kv1.3 channels, causing K⁺ efflux. In contrast, HIV gp41 could trigger IL-18 production via NAIP/NLRC4, independently of priming, as a one-step inflammasome activation. NAIP binds directly to the cytoplasmic tail of HIV envelope protein gp41 and represents the first non-bacterial ligand for the NAIP/NLRC4 inflammasome. These divergent pathways represent novel targets to resolve specific inflammatory pathologies associated with HIV-1 infection in macrophages.     

Butyrate inhibits IL-1β-induced inflammatory gene expression by suppression of NF-κB activity in pancreatic beta cells

Cytokine-induced beta cell dysfunction is a hallmark of type 2 diabetes (T2D). Chronic exposure of beta cells to inflammatory cytokines affects gene expression and impairs insulin secretion. Thus, identification of anti-inflammatory factors that preserve beta cell function represents an opportunity to prevent or treat T2D. Butyrate is a gut microbial metabolite with anti-inflammatory properties for which we recently showed a role in preventing interleukin-1β (IL-1β)-induced beta cell dysfunction, but how prevention is accomplished is unclear. Here, we investigated the mechanisms by which butyrate exerts anti-inflammatory activity in beta cells. We exposed mouse islets and INS-1E cells to a low dose of IL-1β and/or butyrate and measured expression of inflammatory genes and nitric oxide (NO) production. Additionally, we explored the molecular mechanisms underlying butyrate activity by dissecting the activation of the nuclear factor-κB (NF-κB) pathway. We found that butyrate suppressed IL-1β-induced expression of inflammatory genes, such as Nos2, Cxcl1, and Ptgs2, and reduced NO production. Butyrate did not inhibit IκBα degradation nor NF-κB p65 nuclear translocation. Furthermore, butyrate did not affect binding of NF-κB p65 to target sequences in synthetic DNA but inhibited NF-κB p65 binding and RNA polymerase II recruitment to inflammatory gene promoters in the context of native DNA. We found this was concurrent with increased acetylation of NF-κB p65 and histone H4, suggesting butyrate affects NF-κB activity via inhibition of histone deacetylases. Together, our results show butyrate inhibits IL-1β-induced inflammatory gene expression and NO production through suppression of NF-κB activation and thereby possibly preserves beta cell function.     

Identification of Insulin Receptor Substrate 1 (IRS-1) and IRS-2 as Signaling Intermediates in the α6β4 Integrin-Dependent Activation of Phosphoinositide 3-OH Kinase and Promotion of Invasion

Expression of the alpha6beta4 integrin increases the invasive potential of carcinoma cells by a mechanism that involves activation of phosphoinositide 3-OH kinase (PI3K). In the present study, we investigated the signaling pathway by which the alpha6beta4 integrin activates PI3K. Neither the alpha6 nor the beta4 cytoplasmic domain contains the consensus binding motif for PI3K, pYMXM, indicating that additional proteins are likely to be involved in the activation of this lipid kinase by the alpha6beta4 integrin. We identified insulin receptor substrate 1 (IRS-1) and IRS-2 as signaling intermediates in the activation of PI3K by the alpha6beta4 integrin. IRS-1 and IRS-2 are cytoplasmic adapter proteins that do not contain intrinsic kinase activity but rather function by recruiting proteins to surface receptors, where they organize signaling complexes. Ligation of the alpha6beta4 receptor promotes tyrosine phosphorylation of IRS-1 and IRS-2 and increases their association with PI3K, as determined by coimmunoprecipitation. Moreover, we identified a tyrosine residue in the cytoplasmic domain of the beta4 subunit, Y1494, that is required for alpha6beta4-dependent phosphorylation of IRS-2 and activation of PI3K in response to receptor ligation. Most importantly, Y1494 is essential for the ability of the alpha6beta4 integrin to promote carcinoma invasion. Taken together, these results imply a key role for the IRS proteins in the alpha6beta4-dependent promotion of carcinoma invasion.     

Identification of Osteopontin as a Novel Ligand for the Integrin α8β1 and Potential Roles for This Integrin–Ligand Interaction in Kidney Morphogenesis

Epithelio–mesenchymal interactions during kidney organogenesis are disrupted in integrin α8β1-deficient mice. However, the known ligands for integrin α8β1—fibronectin, vitronectin, and tenascin-C—are not appropriately localized to mediate all α8β1 functions in the kidney. Using a method of general utility for determining the distribution of unknown integrin ligands in situ and biochemical characterization of these ligands, we identified osteopontin (OPN) as a ligand for α8β1. We have coexpressed the extracellular domains of the mouse α8 and β1 integrin subunits as a soluble heterodimer with one subunit fused to alkaline phosphatase (AP) and have used the α8β1-AP chimera as a histochemical reagent on sections of mouse embryos. Ligand localization with α8β1-AP in developing bone and kidney was observed to be overlapping with the distribution of OPN. In “far Western” blots of mouse embryonic protein extracts, bands were detected with sizes corresponding to fibronectin, vitronectin, and unknown proteins, one of which was identical to the size of OPN. In a solid-phase binding assay we demonstrated that purified OPN binds specifically to α8β1-AP. Cell adhesion assays using K562 cells expressing α8β1 were used to confirm this result. Together with a recent report that anti-OPN antibodies disrupt kidney morphogenesis, our results suggest that interactions between OPN and integrin α8β1 may help regulate kidney development and other morphogenetic processes.     

A negative feedback loop involving NF-κB/TIR8 regulates IL-1β-induced epithelial- myofibroblast transdifferentiation in human tubular cells

Renal tubular epithelial-myofibroblast transdifferentiation (EMT) plays a central role in the development of renal interstitial fibrosis (RIF). The profibrotic cytokine interleukin (IL)-1 and the IL-1 receptor (IL-1R) also participate in RIF development, and Toll/IL-1R 8 (TIR8), a member of the Toll-like receptor superfamily, has been identified as a negative regulator of IL-1R signaling. However, the functions of TIR8 in IL-1-induced RIF remain unknown. Here, human embryonic kidney epithelial cells (HKC) and unilateral ureteric obstruction (UUO)-induced RIF models on SD rats were used to investigate the functions of TIR8 involving IL-1β-induced EMT. We showed that IL-1β primarily triggers TIR8 expression by activating nuclear factor-κB (NF-κB) in HKC cells. Conversely, high levels of TIR8 in HKC cells repress IL-1β-induced NF-κB activation and inhibit IL-1β-induced EMT. Moreover, in vitro and in vivo findings revealed that TIR8 downregulation facilitated IL-1β-induced NF-κB activation and contributed to TGF-β1-mediated EMT in renal tubular epithelial cells. These results suggested that TIR8 exerts a protective role in IL-1β-mediated EMT and potentially represents a new target for RIF treatment.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12079-021-00620-8.     

Increased Abundance of IncP-1β Plasmids and Mercury Resistance Genes in Mercury-Polluted River Sediments: First Discovery of IncP-1β Plasmids with a Complex mer Transposon as the Sole Accessory Element

Although it is generally assumed that mobile genetic elements facilitate the adaptation of microbial communities to environmental stresses, environmental data supporting this assumption are rare. In this study, river sediment samples taken from two mercury-polluted (A and B) and two nonpolluted or less-polluted (C and D) areas of the river Nura (Kazakhstan) were analyzed by PCR for the presence and abundance of mercury resistance genes and of broad-host-range plasmids. PCR-based detection revealed that mercury pollution corresponded to an increased abundance of mercury resistance genes and of IncP-1β replicon-specific sequences detected in total community DNA. The isolation of IncP-1β plasmids from contaminated sediments was attempted in order to determine whether they carry mercury resistance genes and thus contribute to an adaptation of bacterial populations to Hg pollution. We failed to detect IncP-1β plasmids in the genomic DNA of the cultured Hg-resistant bacterial isolates. However, without selection for mercury resistance, three different IncP-1β plasmids (pTP6, pTP7, and pTP8) were captured directly from contaminated sediment slurry in Cupriavidus necator JMP228 based on their ability to mobilize the IncQ plasmid pIE723. These plasmids hybridized with the merRTΔP probe and conferred Hg resistance to their host. A broad host range and high stability under conditions of nonselective growth were observed for pTP6 and pTP7. The full sequence of plasmid pTP6 was determined and revealed a backbone almost identical to that of the IncP-1β plasmids R751 and pB8. However, this is the first example of an IncP-1β plasmid which had acquired only a mercury resistance transposon but no antibiotic resistance or biodegradation genes. This transposon carries a rather complex set of mer genes and is inserted between Tra1 and Tra2.     

βII spectrin (SPTBN1): biological function and clinical potential in cancer and other diseases

βII spectrin, the most common isoform of non-erythrocyte spectrin, is a cytoskeleton protein present in all nucleated cells. Interestingly, βII spectrin is essential for the development of various organs such as nerve, epithelium, inner ear, liver and heart. The functions of βII spectrin include not only establishing and maintaining the cell structure but also regulating a variety of cellular functions, such as cell apoptosis, cell adhesion, cell spreading and cell cycle regulation. Notably, βII spectrin dysfunction is associated with embryonic lethality and the DNA damage response. More recently, the detection of altered βII spectrin expression in tumors indicated that βII spectrin might be involved in the development and progression of cancer. Its mutations and disorders could result in developmental disabilities and various diseases. The versatile roles of βII spectrin in disease have been examined in an increasing number of studies; nonetheless, the exact mechanisms of βII spectrin are still poorly understood. Thus, we summarize the structural features and biological roles of βII spectrin and discuss its molecular mechanisms and functions in development, homeostasis, regeneration and differentiation. This review highlight the potential effects of βII spectrin dysfunction in cancer and other diseases, outstanding questions for the future investigation of therapeutic targets. The investigation of the regulatory mechanism of βII spectrin signal inactivation and recovery may bring hope for future therapy of related diseases.     

Intestinal Intraepithelial Lymphocytes Are Primed for Gamma Interferon and MIP-1β Expression and Display Antiviral Cytotoxic Activity despite Severe CD4+ T-Cell Depletion in Primary Simian Immunodeficiency Virus Infection

Intraepithelial lymphocytes (IEL) are a critical effector component of the gut-associated lymphoid tissue (GALT) and play an important role in mucosal immunity as well as in the maintenance of the epithelial cell integrity and barrier function. The objective of this study was to determine whether simian immunodeficiency virus (SIV) infection of rhesus macaques would cause alterations in the immunophenotypic profiles of IEL and their mitogen-specific cytokine (gamma interferon [IFN-γ] and MIP-1β) responses (by flow cytometry) and virus-specific cytotoxic T-cell (CTL) activity (by the chromium release assay). Virally infected IEL were detected through the entire course of SIV infection by in situ hybridization. Severe depletion of CD4⁺ single-positive and CD4⁺CD8⁺ double-positive T cells occurred early in primary SIV infection, which was coincident with an increased prevalence of CD8⁺ T cells. This was in contrast to a gradual depletion of CD4⁺ T cells in peripheral blood. The CD8⁺ IEL were the primary producers of IFN-γ and MIP-1β and were found to retain their potential to produce both IFN-γ and MIP-1β through the entire course of SIV infection. SIV-specific CTL activity was detected in primary IEL at 1, 2, and 4 weeks post-SIV infection. These results demonstrated that IEL may be involved in generating antiviral immune responses early in SIV infection and in suppressing viral infection thereafter. Alterations in homeostasis in epithelia due to severe CD4⁺ T-cell depletion accompanied by changes in the cytokine and chemokine production by IEL may play a role in the enteropathogenesis of SIV infection.     

Up‐regulated SAMD9L modulated by TLR2 and HIF‐1α as a promising biomarker in tuberculosis

The aim of this study was to identify potential biomarkers of TB in blood and determine their function in Mtb‐infected macrophages. First of all, WGCNA was used to analyse 9451 genes with significant changes in TB patients’ whole blood. The 220 interferon‐γ‐related genes were identified, and then 30 key genes were screened using Cytoscape. Then, the AUC values of key genes were calculated to further narrow the gene range. Finally, we identified 9 genes from {"type":"entrez-geo","attrs":{"text":"GSE19444","term_id":"19444"}}GSE19444. ROC analysis showed that SAMD9L, among 9 genes, had a high diagnostic value (AUC = 0.925) and a differential diagnostic value (AUC>0.865). To further narrow down the range of DEGs, the top 10 hub‐connecting genes were screened from monocytes ({"type":"entrez-geo","attrs":{"text":"GSE19443","term_id":"19443"}}GSE19443). Finally, we obtained 4 genes (SAMD9L, GBP1, GBP5 and STAT1) by intersections of genes from monocytes and whole blood. Among them, it was found that the function of SAMD9L was unknown after data review, so this paper studied this gene. Our results showed that SAMD9L is up‐regulated and suppresses cell necrosis, and might be regulated by TLR2 and HIF‐1α during Mtb infection. In addition, miR‐181b‐5p is significantly up‐regulated in the peripheral blood plasma of tuberculosis patients, which has a high diagnostic value (AUC = 0.969).     

Aberrant stromal tissue factor localisation and mycolactone-driven vascular dysfunction,exacerbated by IL-1β, are linked to fibrin formation in Buruli ulcer lesions

Buruli ulcer (BU) is a neglected tropical disease caused by subcutaneous infection with Mycobacterium ulcerans and its exotoxin mycolactone. BU displays coagulative necrosis and widespread fibrin deposition in affected skin tissues. Despite this, the role of the vasculature in BU pathogenesis remains almost completely unexplored. We hypothesise that fibrin-driven ischemia can be an ‘indirect’ route to mycolactone-dependent tissue necrosis by a mechanism involving vascular dysfunction. Here, we tracked >900 vessels within contiguous tissue sections from eight BU patient biopsies. Our aim was to evaluate their vascular and coagulation biomarker phenotype and explore potential links to fibrin deposition. We also integrated this with our understanding of mycolactone’s mechanism of action at Sec61 and its impact on proteins involved in maintaining normal vascular function. Our findings showed that endothelial cell dysfunction is common in skin tissue adjacent to necrotic regions. There was little evidence of primary haemostasis, perhaps due to mycolactone-dependent depletion of endothelial von Willebrand factor. Instead, fibrin staining appeared to be linked to the extrinsic pathway activator, tissue factor (TF). There was significantly greater than expected fibrin staining around vessels that had TF staining within the stroma, and this correlated with the distance it extended from the vessel basement membrane. TF-induced fibrin deposition in these locations would require plasma proteins outside of vessels, therefore we investigated whether mycolactone could increase vascular permeability in vitro. This was indeed the case, and leakage was further exacerbated by IL-1β. Mycolactone caused the loss of endothelial adherens and tight junctions by the depletion of VE-cadherin, TIE-1, TIE-2 and JAM-C; all Sec61-dependent proteins. Taken together, our findings suggest that both vascular and lymphatic vessels in BU lesions become “leaky” during infection, due to the unique action of mycolactone, allowing TF-containing structures and plasma proteins into skin tissue, ultimately leading to local coagulopathy and tissue ischemia.     

Norcantharidin,a clinical used chemotherapeutic agent,acts as a powerful inhibitor by interfering with fibrinogen–integrin αIIbβ3 binding in human platelets

During platelet activation, fibrinogen binds to its specific platelet receptor, integrin α_IIbβ₃, thus completing the final common pathway for platelet aggregation. Norcantharidin (NCTD) is a promising anticancer agent in China from medicinal insect blister beetle. In this study, we provided the evidence to demonstrate NCTD (0.1–1.0 μM) possesses very powerful antiplatelet activity in human platelets; nevertheless, it had no effects on surface P‐selectin expression and only slight inhibition on ATP‐release reaction in activated platelets. Moreover, NCTD markedly hindered integrin α_IIbβ₃ activation by interfering with the binding of FITC‐labelled PAC‐1. It also markedly reduced the number of adherent platelets and the single platelet spreading area on immobilized fibrinogen as well as clot retraction. Additionally, NCTD attenuated phosphorylation of proteins such as integrin β₃, Src and FAK in platelets spreading on immobilized fibrinogen. These results indicate that NCTD restricts integrin α_IIbβ₃‐mediated outside‐in signalling in human platelets. Besides, NCTD substantially prolonged the closure time in human whole blood and increased the occlusion time of thrombotic platelet plug formation and prolonged the bleeding time in mice. In conclusion, NCTD has dual activities, it can be a chemotherapeutic agent for cancer treatment, and the other side it possesses powerful antiplatelet activity for treating thromboembolic disorders.